Which Should be Preferred for Moderate-Size Kidney Stones? Ultramini Percutaneous Nephrolithotomy or Retrograde Intrarenal Surgery?

PubMed

Demirbas, Arif; Resorlu, Berkan; Sunay, Mehmet Melih; Karakan, Tolga; Karagöz, Mehmet Ali; Doluoglu, Omer Gokhan

2016-12-01

Comparison of effectiveness and safety of ultramini percutaneous nephrolithotomy (UMPNL) and retrograde intrarenal surgery (RIRS) in treatment of moderate-sized renal stones. The patients scheduled for surgery attributable to renal stones with the greatest diameter of 10 to 25 mm were prospectively analyzed. Patients were randomized into groups with tossing a coin method. The patients who had UMPNL and RIRS were defined as Group I and Group II, respectively. The groups were compared for demograhic data, stone characteristics, operative and postoperative data, stone-free status, and the complications. Student's t-test and Pearson's Chi square tests were used for statistical analysis. p < 0.05 was considered as statistically significant. There were 30 patients in Group I, and 43 patients in Group II. The groups were similar for age, gender, side of the stone, and surface area characteristics of the stone (p = 0.194, p = 0.470, p = 0.990, and p = 0.487, respectively). Stone-free rate was 80% (n = 24) in UMPNL, and 74.4% (n = 32) in RIRS (p = 0.579). Modified Clavien Classification Grade 1 to 2 and 3A to 3B complications were similar in two groups (p = 0.959 and p = 0.192, respectively). Comparison of stone-free rates was 93.3% in UMPNL, and 42.9% in RIRS groups for lower pole stones (p = 0.009). Groups I and II were significantly different for visual analog scale scores for postoperative pain (4.73 ± 1.25 vs 2.30 ± 1.12), hospital stay (2.46 ± 3.02 vs 1.37 ± 1.48 days), and time to return to normal daily life (11.26 ± 5.55 vs 6.65 ± 4.30 days) (p < 0.001, p < 0.001, and p < 0.001, respectively). Both UMPNL and RIRS procedures are effective and safe methods in treatment of middle-sized renal stones. However, UMPNL is more effective than RIRS in treatment of lower pole stones. RIRS is more advantageous when loss from work is taken into consideration.

Pediatric ureteroscopic management of intrarenal calculi.

PubMed

Tanaka, Stacy T; Makari, John H; Pope, John C; Adams, Mark C; Brock, John W; Thomas, John C

2008-11-01

Data addressing ureteroscopic management of intrarenal calculi in prepubertal children are limited. We reviewed our experience from January 2002 through December 2007. We retrospectively reviewed ureteroscopic procedures for intrarenal calculi in children younger than 14 years. Stone-free status was determined with postoperative imaging. Multiple logistic regression analysis was used to assess the influence of preoperative factors on initial stone-free status and the need for additional procedures. Intrarenal calculi were managed ureteroscopically in 52 kidneys in 50 children with a mean age of 7.9 years (range 1.2 to 13.6). Mean stone size was 8 mm (range 1 to 16). Stone-free rate after a single ureteroscopic procedure was 50% (25 of 50 patients) on initial postoperative imaging and 58% (29 of 50) with extended followup. Initial stone-free status was dependent on preoperative stone size (p = 0.005) but not stone location. Additional stone procedures were required in 18 upper tracts. Younger patient age (p = 0.04) and larger preoperative stone size (p = 0.002) were associated with the need for additional procedures. Additional procedures were required in more than half of the stones 6 mm or larger but in no stone smaller than 6 mm. Ureteroscopy is a safe method for the treatment of intrarenal calculi in the prepubertal population. Our ureteroscopic stone-free rate for intrarenal stones is lower than that reported for ureteral stones. Parents should be informed that additional procedures will likely be required, especially in younger patients and those with stones larger than 6 mm.

Cumulative sum analysis for experiences of a single-session retrograde intrarenal stone surgery and analysis of predictors for stone-free status.

PubMed

Cho, Sung Yong; Choo, Min Soo; Jung, Jae Hyun; Jeong, Chang Wook; Oh, Sohee; Lee, Seung Bae; Son, Hwancheol; Jeong, Hyeon

2014-01-01

This study investigated the learning curve of a single-session retrograde intrarenal surgery (RIRS) in patients with mid-sized stones. Competence and trainee proficiency for RIRS was assessed using cumulative sum analysis (CUSUM). The study design and the use of patients' information stored in the hospital database were approved by the Institutional Review Board of our institution. A retrospective review was performed for 100 patients who underwent a single-session RIRS. Patients were included if the main stone had a maximal diameter between 10 and 30 mm. The presence of a residual stone was checked on postoperative day 1 and at one-month follow-up visit. Fragmentation efficacy was calculated "removed stone volume (mm(3)) divided by operative time (min)". CUSUM analysis was used for monitoring change in fragmentation efficacy, and we tested whether or not acceptable surgical outcomes were achieved. The mean age was 54.7±14.8 years. Serum creatinine level did not change significantly. Estimated GFR and hemoglobin were within normal limits postoperatively. The CUSUM curve tended to be flat until the 25th case and showed a rising pattern but declined again until the 56th case. After that point, the fragmentation efficacy reached a plateau. The acceptable level of fragmentation efficacy was 25 ml/min. Multivariate logistic regression analyses showed that stone-free rate was significantly lower for cases with multiple stones than those with a single stone (OR = 0.147, CI 0.032 - 0.674, P value  = 0.005) and for cases with higher number of sites (OR = 0.676, CI 0.517 - 0.882, P value  = 0.004). The statistical analysis of RIRS learning experience revealed that 56 cases were required for reaching a plateau in the learning curve. The number of stones and the number of sites were significant predictors for stone-free status.

Comparison of retrograde intrarenal surgery and mini-percutaneous nephrolithotomy in management of lower-pole renal stones with a diameter of smaller than 15 mm.

PubMed

Kirac, Mustafa; Bozkurt, Ömer Faruk; Tunc, Lutfi; Guneri, Cagri; Unsal, Ali; Biri, Hasan

2013-06-01

The aim of this study was to compare the outcomes of retrograde intrarenal surgery (RIRS) and miniaturized percutaneous nephrolithotomy (mini-PNL) in management of lower-pole renal stones with a diameter smaller than 15 mm. Between December 2009 and July 2012, the patients with the diagnosis of lower-pole stones were evaluated by ultrasonography, intravenous pyelography and computed tomography. The records of 73 evaluable patients who underwent mini-PNL (n = 37) or RIRS (n = 36) for lower-pole (LP) stones with diameter smaller than 15 mm were reviewed retrospectively. Of the 73 patients, 37 underwent mini-PNL and 36 underwent RIRS. The stone-free rates were 89.1 and 88.8 % for mini-PNL and RIRS groups, respectively. The mean operation time was 53.7 ± 14.5 in the mini-PNL group but 66.4 ± 15.8 in the RIRS group (P = 0.01). The mean fluoroscopy times and hospitalization times were significantly higher in the mini-PNL group. There was no major complication in any patient. RIRS and mini-PNL are safe and effective methods for treatment of LP calculi with a diameter smaller than 15 mm. RIRS is a non-invasive and feasible treatment option, and has also short hospitalization time, low morbidity and complication rate. It may be an alternative of mini-PNL in the treatment LP calculi with smaller than 15 mm.

INTRARENAL GHRELIN RECEPTOR INHIBITION AMELIORATES ANGIOTENSIN II-DEPENDENT HYPERTENSION IN RATS.

PubMed

Kemp, Brandon A; Howell, Nancy L; Padia, Shetal H

2018-06-20

The intrarenal ghrelin receptor (GR) is localized to collecting duct (CD) cells where it increases αENaC-dependent sodium reabsorption in rodents. We hypothesized that chronic GR inhibition with intrarenal GR siRNA lowers blood pressure (BP) in Angiotensin II-dependent hypertension via reductions in αENaC-dependent sodium reabsorption. Uninephrectomized Sprague-Dawley rats (N=121) received subcutaneous osmotic pumps for chronic systemic delivery of Angiotensin II or vehicle (5% dextrose in water). Rats also received intrarenal infusion of vehicle, GR siRNA, or scrambled (SCR) siRNA. In rats receiving intrarenal vehicle or intrarenal SCR siRNA, systemic Angiotensin II infusion increased sodium retention and BP on day 1, and BP remained elevated throughout the 5-day study. These rats also demonstrated increased CD GR expression after 5 days of infusion. However, intrarenal GR siRNA infusion prevented Angiotensin II-mediated sodium retention on day 1, induced a continuously negative cumulative sodium balance compared with Angiotensin II alone, and reduced BP chronically. Glomerular filtration rate and renal blood flow remained unchanged in GR siRNA-infused rats. Systemic Angiotensin II infusion also increased serum aldosterone levels, CD αENaC and pSGK1 expression in rats with intrarenal SCR siRNA; however these effects were not observed in the presence of intrarenal GR siRNA, despite exposure to the same systemic Angiotensin II. These data demonstrate that chronic inhibition of intrarenal GR activity significantly reduces αENaC -dependent sodium retention, resulting in a negative cumulative sodium balance, thereby ameliorating Angiotensin II-induced hypertension in rats. Renal GRs represent a novel therapeutic target for the treatment of hypertension and other sodium-retaining states.

Systematic review and meta-analysis of the clinical effectiveness of shock wave lithotripsy, retrograde intrarenal surgery, and percutaneous nephrolithotomy for lower-pole renal stones.

PubMed

Donaldson, James F; Lardas, Michael; Scrimgeour, Duncan; Stewart, Fiona; MacLennan, Steven; Lam, Thomas B L; McClinton, Samuel

2015-04-01

The prevalence of urolithiasis is increasing. Lower-pole stones (LPS) are the most common renal calculi and the most likely to require treatment. A systematic review comparing shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS), and percutaneous nephrolithotomy (PNL) in the treatment of ≤20 mm LPS in adults was performed. Comprehensive searches revealed 2741 records; 7 randomised controlled trials (RCTs) recruiting 691 patients were included. Meta-analyses for stone-free rate (SFR) at ≤3 mo favoured PNL over SWL (risk ratio [RR]: 2.04; 95% confidence interval [CI], 1.50-2.77) and RIRS over SWL (RR: 1.31; 95% CI, 1.08-1.59). Stone size subgroup analyses revealed PNL and RIRS were considerably more effective than SWL for >10 mm stones, but the magnitude of benefit was markedly less for ≤10 mm stones. The quality of evidence (Grading of Recommendations Assessment, Development, and Evaluation [GRADE]) for SFR was moderate for these comparisons. The median SFR from reported RCTs suggests PNL is more effective than RIRS. The findings regarding other outcomes were inconclusive because of limited and inconsistent data. Well-designed, prospective, comparative studies that measure these outcomes using standardised definitions are required, particularly for the direct comparison of PNL and RIRS. This systematic review, which used Cochrane methodology and GRADE quality-of-evidence assessment, provides the first level 1a evidence for the management of LPS. We thoroughly examined the literature to compare the benefits and harms of the different ways of treating kidney stones located at the lower pole. PNL and RIRS were superior to SWL in clearing the stones within 3 mo, but we were unable to make any conclusions regarding other outcomes. More data is required from reliable studies before firm recommendations can be made. Copyright © 2014 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Role of the intrarenal renin-angiotensin system in the progression of renal disease.

PubMed

Urushihara, Maki; Kagami, Shoji

2017-09-01

The intrarenal renin-angiotensin system (RAS) has many well-documented pathophysiologic functions in both blood pressure regulation and renal disease development. Angiotensin II (Ang II) is the major bioactive product of the RAS. It induces inflammation, renal cell growth, mitogenesis, apoptosis, migration, and differentiation. In addition, Ang II regulates the gene expression of bioactive substances and activates multiple intracellular signaling pathways that are involved in renal damage. Activation of the Ang II type 1 (AT1) receptor pathway results in the production of proinflammatory mediators, intracellular formation of reactive oxygen species, cell proliferation, and extracellular matrix synthesis, which in turn facilities renal injury. Involvement of angiotensinogen (AGT) in intrarenal RAS activation and development of renal disease has previously been reported. Moreover, studies have demonstrated that the urinary excretion rates of AGT provide a specific index of the intrarenal RAS status. Enhanced intrarenal AGT levels have been observed in experimental models of renal disease, supporting the concept that AGT plays an important role in the development and progression of renal disease. In this review, we focus on the role of intrarenal RAS activation in the pathophysiology of renal disease. Additionally, we explored the potential of urinary AGT as a novel biomarker of intrarenal RAS status in renal disease.

Stone volume is best predictor of operative time required in retrograde intrarenal surgery for renal calculi: implications for surgical planning and quality improvement.

PubMed

Sorokin, Igor; Cardona-Grau, Diana K; Rehfuss, Alexandra; Birney, Alan; Stavrakis, Costas; Leinwand, Gabriel; Herr, Allen; Feustel, Paul J; White, Mark D

2016-11-01

Retrograde intrarenal surgery (RIRS) is highly successful at eliminating renal stones of various sizes and compositions. As urologists are taking on more complex procedures using RIRS, this has led to an increase in operative (OR) times. Our objective was to determine the best predictor of OR time in patients undergoing RIRS. We retrospectively reviewed the records of patients undergoing unilateral RIRS for solitary stones over a 10 year time span. Stones were fragmented and actively extracted using a basket. Variables potentially affecting OR time such as patient age, sex, BMI, lower pole stone location, volume, Hounsfield units (HU), composition, ureteral access sheath (UAS) use, and pre-operative stenting were collected. Multivariable linear and stepwise regression was used to evaluate the predictors of OR time. There were 118 patients that met inclusion criteria. The median stone volume was 282.6 mm 3 (IQR 150.7-644.7) and the mean OR time was 50 min (±25.9 SD). On univariate linear regression, stone volume had a moderate correlation with OR time (y = 0.022x + 38.2, r 2  = 0.363, p < 0.01). On multivariable stepwise regression, stone volume had the strongest impact on OR time, increasing time by 2.0 min for each 100 mm 3 increase in stone volume (p < 0.001). UAS added 13.5 (SE 3.9, p = 0.001) minutes and renal lower pole location added 9 min (SE 4.3, p = 0.03) in each case they were used. Pre-operative stenting, HU, calcium oxalate stone composition, sex, and age had no significant effect on OR time. Amongst the main stone factors in RIRS, stone volume has the strongest impact on operative time. This can be used to predict the length of the procedure by roughly adding 2 min per 100 mm 3 increase in stone volume.

The comparison of minimally invasive percutaneous nephrolithotomy and retrograde intrarenal surgery for stones larger than 2 cm in patients with a solitary kidney: a matched-pair analysis.

PubMed

Zeng, Guohua; Zhu, Wei; Li, Jiasheng; Zhao, Zhijian; Zeng, Tao; Liu, Chenli; Liu, Yang; Yuan, Jian; Wan, Shaw P

2015-08-01

To compare the treatment outcomes between retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (MPCNL) for the management of stones larger than 2 cm in patients with solitary kidney. Between December 2012 and March 2014, 53 patients with a solitary kidney suffering from urinary stones larger than 2 cm were treated with RIRS. The outcomes of these patients were compared to a cohort of similar solitary kidney stone patients who underwent MPCNL using a matched-pair analysis (1:1 scenario). Cases were matched sequentially using the following criteria: size, number and location of stones, age, BMI, gender and previous ipsilateral open surgery. A stone-free rate (SFR) of 43.4 % was achieved after a single procedure in patients treated with RIRS and a SFR of 71.70 % in patients treated with MPCNL (p = 0.003). The operative time for RIRS was longer (p = 0.002), but the median hospital stay was shorter (p < 0.001). Average drop in hemoglobin level was comparable in both groups (9.30 vs. 10.85 g/L, p = 0.35). The transfusion rate as well as the incidence of postoperative complications such as fever and urosepsis was not statistically different between these two groups. Major complications (Clavien score 3a-4a) occurred in 3.77 and 1.89 %, RIRS and MPCNL, respectively (p = 1.000). Patients with a solitary kidney suffering from stones larger than 2 cm in size who undergo MPCNL had a higher SFR than RIRS. The complications were comparable in both groups. Even though RIRS patients spent less time in hospital, this procedure might not be an effective treatment as MPCNL in solitary kidneys with larger and multiple stones.

Mini Versus Standard Percutaneous Nephrolithotomy: The Impact of Sheath Size on Intrarenal Pelvic Pressure and Infectious Complications in a Porcine Model.

PubMed

Loftus, Christopher J; Hinck, Bryan; Makovey, Iryna; Sivalingam, Sri; Monga, Manoj

2018-04-01

To determine how sheath and endoscope size affect intrarenal pelvic pressures and risk of postoperative infectious complications comparing "Mini" vs "Standard" percutaneous nephrolithotomy (PCNL). Uropathogenic Escherichia coli were grown and 10 9 of them were instilled into the porcine renal pelvis through retrograde access for 1 hour. Percutaneous access utilized a 14/16F 20 cm ureteral access sheath for the Mini arm and a 30F sheath for the Standard arm. Nephroscopy was simulated utilizing either an 8/9.8F semirigid ureteroscope or 26F nephroscope for 1 hour while intrarenal pelvic pressure was continuously monitored. Blood and tissue cultures of kidney, liver, and spleen biopsies were plated and incubated and positive cultures were confirmed with polymerase chain reaction. Intrapelvic pressures were higher in the Mini group, 18.76 ± 5.82 mm Hg vs 13.56 ± 5.82 mm Hg (p < 0.0001). Time spent above 30 mm Hg was greater in the Mini arm, 117.0 seconds vs 66.1 seconds (p = 0.0452). All pigs had positive kidney tissue cultures whereas spleen cultures were positive in 100% and 60% of pigs in the Mini and Standard arms, respectively (p = 0.0253); 90% and 30% had positive liver tissue culture in the Mini and Standard arms, respectively (p = 0.0062). Blood cultures were positive in 30% of pigs in the Mini arm compared with none in the Standard arm (p = 0.0603). Mini-PCNL was associated with higher intrarenal pressures and higher risk of end organ bacterial seeding in the setting of an infected collecting system. This suggests a higher potential for infectious complications in a clinical setting.

Micropercutaneous nephrolithotomy (microperc) vs retrograde intrarenal surgery for the management of small renal calculi: a randomized controlled trial.

PubMed

Sabnis, Ravindra B; Ganesamoni, Raguram; Doshi, Amit; Ganpule, Arvind P; Jagtap, Jitendra; Desai, Mahesh R

2013-08-01

To compare micropercutaneous nephrolithotomy (microperc) and retrograde intrarenal surgery (RIRS) for the management of renal calculi <1.5 cm with regard to stone clearance rates and surgical characteristics, complications and postoperative recovery. Seventy patients presenting with renal calculi <1.5 cm were equally randomized to a microperc or a RIRS group between February 2011 and August 2012 in this randomized controlled trial. Randomization was based on centralized computer-generated numbers. Patients and authors assessing the outcomes were not blinded to the procedure. Microperc was performed using a 4.85-F (16-gauge) needle with a 272-μm laser fibre. RIRS was performed using a uretero-renoscope. Variables studied were stone clearance rates, operating time, need for JJ stenting, intra-operative and postoperative complications (according to the Clavien-Dindo classification system), surgeon discomfort score, postoperative pain score, analgesic requirement and hospital stay. Stone clearance was assessed using ultrasonography and X-ray plain abdominal film of kidney, ureter and bladder at 3 months. There were 35 patients in each group. All the patients were included in the final analysis. The stone clearance rates in the microperc and RIRS groups were similar (97.1 vs 94.1%, P = 1.0). The mean [sd] operating time was similar between the groups (51.6 [18.5] vs 47.1 [17.5], P = 0.295). JJ stenting was required in a lower proportion of patients in the microperc group (20 vs 62.8%, P < 0.001). Intra-operative complications were a minor pelvic perforation in one patient and transient haematuria in two patients, all in the microperc group. One patient in each group required conversion to miniperc. One patient in the microperc group needed RIRS for small residual calculi 1 day after surgery. The decrease in haemoglobin was greater in the microperc group (0.96 vs 0.56 g/dL, P < 0.001). The incidence of postoperative fever (Clavien I) was similar in the two groups

Comparison of retrograde intrarenal surgery versus a single-session percutaneous nephrolithotomy for lower-pole stones with a diameter of 15 to 30 mm: A propensity score-matching study.

PubMed

Jung, Gyoo Hwan; Jung, Jae Hyun; Ahn, Tae Sik; Lee, Joong Sub; Cho, Sung Yong; Jeong, Chang Wook; Lee, Seung Bae; Kim, Hyeon Hoe; Oh, Seung-June

2015-07-01

To investigate surgical outcomes between retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) groups for a main stone sized 15 to 30 mm and located in the lower-pole calyx. Patients who underwent PNL or RIRS for a main stone sized 15 to 30 mm and located in the lower-pole calyx were retrospectively reviewed. Each patient in the RIRS group was matched to one in the PNL group on the basis of calculated propensity scores by use of age, sex, body mass index, previous treatment history, stone site, maximum stone size, and stone volume. We compared perioperative outcomes between the unmatched and matched groups. Patients underwent PNL (n=87, 66.4%) or RIRS (n=44, 33.6%). After matching, 44 patients in each group were included. Mean patient age was 54.4 ± 13.7 years. Perioperative hemoglobin drop was significantly higher and the hospital stay was longer in the PNL group than in the RIRS group. The operative time was significantly longer in the RIRS group than in the PNL group. Stone-free rates were higher and complications rates were lower in the RIRS group than in the PNL group without statistical significance. The presence of a stone located in the lower-anterior minor calyx was a predictor of stone-free status. RIRS and single-session PNL for patients with a main stone of 15 to 30 mm located in the lower-pole calyx showed comparable surgical results. However, RIRS can be performed more safely than PNL with less bleeding. Stones in the lower-anterior minor calyx should be carefully removed during these procedures.

Comparison of retrograde intrarenal surgery versus a single-session percutaneous nephrolithotomy for lower-pole stones with a diameter of 15 to 30 mm: A propensity score-matching study

PubMed Central

Jung, Gyoo Hwan; Jung, Jae Hyun; Ahn, Tae Sik; Lee, Joong Sub; Cho, Sung Yong; Jeong, Chang Wook; Lee, Seung Bae; Kim, Hyeon Hoe

2015-01-01

Purpose To investigate surgical outcomes between retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) groups for a main stone sized 15 to 30 mm and located in the lower-pole calyx. Materials and Methods Patients who underwent PNL or RIRS for a main stone sized 15 to 30 mm and located in the lower-pole calyx were retrospectively reviewed. Each patient in the RIRS group was matched to one in the PNL group on the basis of calculated propensity scores by use of age, sex, body mass index, previous treatment history, stone site, maximum stone size, and stone volume. We compared perioperative outcomes between the unmatched and matched groups. Results Patients underwent PNL (n=87, 66.4%) or RIRS (n=44, 33.6%). After matching, 44 patients in each group were included. Mean patient age was 54.4±13.7 years. Perioperative hemoglobin drop was significantly higher and the hospital stay was longer in the PNL group than in the RIRS group. The operative time was significantly longer in the RIRS group than in the PNL group. Stone-free rates were higher and complications rates were lower in the RIRS group than in the PNL group without statistical significance. The presence of a stone located in the lower-anterior minor calyx was a predictor of stone-free status. Conclusions RIRS and single-session PNL for patients with a main stone of 15 to 30 mm located in the lower-pole calyx showed comparable surgical results. However, RIRS can be performed more safely than PNL with less bleeding. Stones in the lower-anterior minor calyx should be carefully removed during these procedures. PMID:26175872

The absence of intrarenal ACE protects against hypertension

PubMed Central

Gonzalez-Villalobos, Romer A.; Janjoulia, Tea; Fletcher, Nicholas K.; Giani, Jorge F.; Nguyen, Mien T.X.; Riquier-Brison, Anne D.; Seth, Dale M.; Fuchs, Sebastien; Eladari, Dominique; Picard, Nicolas; Bachmann, Sebastian; Delpire, Eric; Peti-Peterdi, Janos; Navar, L. Gabriel; Bernstein, Kenneth E.; McDonough, Alicia A.

2013-01-01

Activation of the intrarenal renin-angiotensin system (RAS) can elicit hypertension independently from the systemic RAS. However, the precise mechanisms by which intrarenal Ang II increases blood pressure have never been identified. To this end, we studied the responses of mice specifically lacking kidney angiotensin-converting enzyme (ACE) to experimental hypertension. Here, we show that the absence of kidney ACE substantially blunts the hypertension induced by Ang II infusion (a model of high serum Ang II) or by nitric oxide synthesis inhibition (a model of low serum Ang II). Moreover, the renal responses to high serum Ang II observed in wild-type mice, including intrarenal Ang II accumulation, sodium and water retention, and activation of ion transporters in the loop of Henle (NKCC2) and distal nephron (NCC, ENaC, and pendrin) as well as the transporter activating kinases SPAK and OSR1, were effectively prevented in mice that lack kidney ACE. These findings demonstrate that ACE metabolism plays a fundamental role in the responses of the kidney to hypertensive stimuli. In particular, renal ACE activity is required to increase local Ang II, to stimulate sodium transport in loop of Henle and the distal nephron, and to induce hypertension. PMID:23619363

External Validation and Evaluation of Reliability and Validity of the Modified Seoul National University Renal Stone Complexity Scoring System to Predict Stone-Free Status After Retrograde Intrarenal Surgery.

PubMed

Park, Juhyun; Kang, Minyong; Jeong, Chang Wook; Oh, Sohee; Lee, Jeong Woo; Lee, Seung Bae; Son, Hwancheol; Jeong, Hyeon; Cho, Sung Yong

2015-08-01

The modified Seoul National University Renal Stone Complexity scoring system (S-ReSC-R) for retrograde intrarenal surgery (RIRS) was developed as a tool to predict stone-free rate (SFR) after RIRS. We externally validated the S-ReSC-R. We retrospectively reviewed 159 patients who underwent RIRS. The S-ReSC-R was assigned from 1 to 12 according to the location and number of sites involved. The stone-free status was defined as no evidence of a stone or with clinically insignificant residual fragment stones less than 2 mm. Interobserver and test-retest reliabilities were evaluated. Statistical performance of the prediction model was assessed by its predictive accuracy, predictive probability, and clinical usefulness. Overall SFR was 73.0%. The SFRs were 86.7%, 70.2%, and 48.6% in low-score (1-2), intermediate-score (3-4), and high-score (5-12) groups, respectively (p<0.001). External validation of S-ReSC-R revealed an area under the curve (AUC) of 0.731 (95% CI 0.650-0.813). The AUC of the three-titered S-ReSC-R was 0.701 (95% CI 0.609-0.794). The calibration plot showed that the predicted probability of SFR had a concordance comparable to that of observed frequency. The Hosmer-Lemeshow goodness of fit test revealed a p-value of 0.01 for the S-ReSC-R and 0.90 for the three-titered S-ReSC-R. Interobserver and test-retest reliabilities revealed an almost perfect level of agreement. The present study proved the predictive value of S-ReSC-R to predict SFR following RIRS in an independent cohort. Interobserver and test-retest reliabilities confirmed that S-ReSC-R was reliable and valid.

[Intrarenal veins. Study of the segmental angioarchitecture and intersegmental anastomoses].

PubMed

Mandarim-Lacerda, C A; Sampaio, F J; Passos, M A; Dallalana, E M

1983-01-01

Fifty human adult venous casts were studied in a examine of the disposition and anastomoses of the intrarenal veins. The Vinylite injection and hydrocloric acid corrosion method was used. Casts with two main venous trunks (32%), three trunks (36%) and four trunks (32%) were found. Large longitudinal and transversal anastomotic branches among the main venous trunks do not content the kidney venous segmental division, in contrast to intrarenal arteries. The longitudinal anastomoses are named of 1st. order (sinusal), of 2nd. order (pyramidal) and of 3rd. order (marginal), in relation to interlobar veins, arciform veins, and stellate veins, respectively.

Retrograde renal hilar dissection and segmental arterial clamping: a simple modification to achieve super-selective robotic partial nephrectomy.

PubMed

Greene, Richard N; Sutherland, Douglas E; Tausch, Timothy J; Perez, Deo S

2014-03-01

Super-selective vascular control prior to robotic partial nephrectomy (also known as 'zero-ischemia') is a novel surgical technique that promises to reduce warm ischemia time. The technique has been shown to be feasible but adds substantial technical complexity and cost to the procedure. We present a simplified retrograde dissection of the renal hilum to achieve selective vascular control during robotic partial nephrectomy. Consecutive patients with stage 1 solid and complex cystic renal masses underwent robotic partial nephrectomies with selective vascular control using a modification to previously described super-selective robotic partial nephrectomy. In each case, the renal arterial branch supplying the mass and surrounding parenchyma was dissected in a retrograde fashion from the tumor. Intra-renal dissection of the interlobular artery was not performed. Intra-operative immunofluorescence was not utilized as assessment of parenchymal ischemia was documented before partial nephrectomy. Data was prospectively collected in an IRB-approved partial nephrectomy database. Operative variables between patients undergoing super-selective versus standard robotic partial nephrectomy were compared. Super-selective partial nephrectomy with retrograde hilar dissection was successfully completed in five consecutive patients. There were no complications or conversions to traditional partial nephrectomy. All were diagnosed with renal cell carcinoma and surgical margins were all negative. Estimated blood loss, warm ischemia time, operative time and length of stay were all comparable between patients undergoing super-selective and standard robotic partial nephrectomy. Retrograde hilar dissection appears to be a feasible and safe approach to super-selective partial nephrectomy without adding complex renovascular surgical techniques or cost to the procedure.

Efficacy of endoscopic combined intrarenal surgery in the prone split-leg position for staghorn calculi.

PubMed

Hamamoto, Shuzo; Yasui, Takahiro; Okada, Atsushi; Koiwa, Satoshi; Taguchi, Kazumi; Itoh, Yasunori; Kawai, Noriyasu; Hashimoto, Yoshihiro; Tozawa, Keiichi; Kohri, Kenjiro

2015-01-01

Abstract Purpose: To evaluate the efficacy of endoscopic combined intrarenal surgery (ECIRS) using retrograde flexible ureteroscopy and miniature percutaneous nephrolithotomy (PNL) for the treatment of patients with staghorn calculi in the prone split-leg position. We retrospectively reviewed the records of 42 patients with staghorn calculi (45.8±3.2 mm) who underwent ECIRS using retrograde flexible ureteroscopy and miniature PNL in the prone split-leg position for the treatment of staghorn calculi in our center between December 2010 and August 2013. A flexible ureteroscope with a laser fiber was inserted through a ureteral access sheath, and lithoclast lithotripsy was performed through a mini-percutaneous tract. Both procedures were performed simultaneously by two urologists. Surgical parameters, including surgical time, stone-free (SF) rates, modified Clavien complication grades, and risk factors for residual stones, were analyzed. Fifteen patients (35.7%) had complete staghorn calculi. Among the 42 staghorn calculi treated, 23 had 0 to 5 stone branches, 14 had 6 to 10 stone branches, and 5 had ≥11 stone branches. All procedures were performed successfully using a single lithotripsy tract with the patient in the prone split-leg position. The mean surgical time was 143.2±9.2 minutes. The initial SF rate was 71.4%, and the final SF rate was 83.3% after further treatment. One patient required a blood transfusion (2.4%), but no patient experienced a ≥3 Clavien grade complication. Risk factors for residual stones were stone size, stone surface area, complete staghorn calculi, and the number of stone branches. ECIRS for staghorn calculi in the prone split-leg position is a safe, efficient, and versatile method for the effective management of staghorn calculi without the creation of multiple percutaneous tracts.

Prospective analysis of a complete retrograde ureteroscopic technique with holmium laser stent cutting for management of encrusted ureteral stents.

PubMed

Thomas, Alexandre; Cloutier, Jonathan; Villa, Luca; Letendre, Julien; Ploumidis, Achilles; Traxer, Olivier

2017-03-14

To propose and evaluate a new endoscopic technique using only a retrograde ureteroscopic approach for the removal of heavily encrusted ureteral stents. Data from 51 consecutive patients with encrusted and retained ureteral stents were prospectively collected. Description of the successive steps of surgery is detailed. The Holmium-YAG laser properties offer the opportunity for fragmentation of stent-attached encrustation and the ability to cut the stent itself. Reducing the length of the stent is critical to creating space in the ureter and to allow free access for ureteroscopes or ureteral access sheath placement. The primary outcome of this study was the feasibility and the safety of this retrograde intra-renal approach. Some factors of encrustation and outcomes are also discussed in comparison with lithotripsy, percutaneous, laparoscopic, open surgery or a combination of these techniques. The removal of the encrusted stent was possible with only this retrograde technique in 98% of patients. The transection of the encrusted stent with the Holmium-YAG laser was useful in 71% of the patients. Mean operative time was 110 minutes and mean hospital stay was 2.33 days. Postoperative complications were mainly non-obstructive pyelonephritis (10%). The most significant predictor of this life threatened complication was the presence of struvite stones with the encrusted stent (p=0,018). Contrariwise, operative time, BMI, gender and encrustation rate were not associated with postoperative pyelonephritis. Cystine stone disease or pregnancy both led to faster stent encrustation. Retrograde ureteroscopic surgery is efficient and safe for removing retained stents and associated stone burdens. The Holmium-YAG laser is essential to perform the encrustation removal and sectioning of the stent.

Extracorporeal shock wave lithotripsy (ESWL) versus percutaneous nephrolithotomy (PCNL) or retrograde intrarenal surgery (RIRS) for kidney stones.

PubMed

Srisubat, Attasit; Potisat, Somkiat; Lojanapiwat, Bannakij; Setthawong, Vasun; Laopaiboon, Malinee

2014-11-24

Stones in the urinary tract are a common medical problem in the general population. At present, the great expansion in minimally invasive techniques has led to the decrease in open surgery. Extracorporeal shock wave lithotripsy (ESWL) has been introduced as an alternative approach which disintegrates stones in the kidney and upper urinary tract through the use of shock waves. Nevertheless, as there are limitations with the success rate in ESWL, other minimally invasive modalities for kidney stones such as percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) are also widely applied. This is an update of a review first published in 2009. This review aimed to assess the effectiveness and complications of ESWL for kidney stones compared with PCNL or RIRS. We searched the Cochrane Renal Group's Specialised Register to 3 March 2014 through contact with the Trials' Search Co-ordinator using search terms relevant to this review. Randomised controlled trials (RCTs) assessing the use of ESWL compared to PCNL or RIRS for kidney stone management. Two authors independently assessed all the studies for inclusion. Statistical analyses were performed using the random effects model and the results expressed as risk ratio (RR) for dichotomous outcomes or mean difference (MD) for continuous data with 95% confidence intervals (CI). Five studies (338 patients) were included, four studies compared ESWL to PCNL and one compared ESWL with RIRS. Random sequence generation was reported in three studies and unclear in two. Allocation concealment was not reported in any of the included studies. Blinding of participants and investigators could not be undertaken due to the nature of the interventions; blinding of outcome assessors was not reported. Reporting bias was judged to be low risk in all studies. One study was funded by industry and in one study the number of participants in each group was unbalanced.The success of treatment at three months was significantly

The mechanisms of intrarenal hemodynamic changes following acute arterial occlusion.

DOT National Transportation Integrated Search

1963-10-01

The hemodynamic response of the kidney to acute arterial occlusion is poorly understood. The purpose of the present study was to determine intrarenal hemodynamic changes in intact and isolated kidneys following arterial occlusion. : The relative role...

Functional (dissociative) retrograde amnesia.

PubMed

Markowitsch, H J; Staniloiu, A

2016-01-01

Retrograde amnesia is described as condition which can occur after direct brain damage, but which occurs more frequently as a result of a psychiatric illness. In order to understand the amnesic condition, content-based divisions of memory are defined. The measurement of retrograde memory is discussed and the dichotomy between "organic" and "psychogenic" retrograde amnesia is questioned. Briefly, brain damage-related etiologies of retrograde amnesia are mentioned. The major portion of the review is devoted to dissociative amnesia (also named psychogenic or functional amnesia) and to the discussion of an overlap between psychogenic and "brain organic" forms of amnesia. The "inability of access hypothesis" is proposed to account for most of both the organic and psychogenic (dissociative) patients with primarily retrograde amnesia. Questions such as why recovery from retrograde amnesia can occur in retrograde (dissociative) amnesia, and why long-term new learning of episodic-autobiographic episodes is possible, are addressed. It is concluded that research on retrograde amnesia research is still in its infancy, as the neural correlates of memory storage are still unknown. It is argued that the recollection of episodic-autobiographic episodes most likely involves frontotemporal regions of the right hemisphere, a region which appears to be hypometabolic in patients with dissociative amnesia. © 2016 Elsevier B.V. All rights reserved.

[Evaluation of upper urinary tract function in patients undergoing autoplastic surgery for hydronphrosis of the intrarenal pelvis].

PubMed

Kurbanaliev, R M; Usupbaev, A Ch; Kolesnichenko, I V; Sadyrbekov, N Zh; Sultanov, B M

2018-05-01

To investigate the functional state of the upper urinary tract in patients undergoing autoplastic surgery for a hydronophrosis of the intrarenal pelvis. The study comprised 78 patients with the intrarenal pelvis and impaired urinary outflow due to stricture of the ureteropelvic junction and vascular conflict (interatrial and arteriovenous narrowing), who underwent pyeloplasty using autologous tunica vaginalis. All patients underwent an incision of ureteropelvic stricture and resection of the parietal layer of the tunica vaginalis which was used to repair the obstruction site and internal stenting of the upper urinary tract. The patients were examined at baseline and during follow-up ranging from 3 months to 3 years. At three months after surgery, there was a decrease in the size of the renal pelvis and calyces with an improvement of all parameters of uro- and hemodynamics. At three years after surgery, the structural and functional parameters of the upper urinary tract were completely restored. Obstructive uropathy, resulting from the intrarenal pelvis, leads to persistently impaired urinary outflow from the upper urinary tract. Surgical intervention is the only curative treatment able to restore the urinary flow. In men with the intrarenal pelvis, the autoplastic surgery of the ureteropelvic junction obstruction using a parietal layer of the tunica vaginalis is an effective surgical modality improving renal pelvis capacity and contributing to the recovery of urinary outflow from the upper urinary tract.

A CARE-compliant article: a case of retrograde intussusception with Uncut-Roux-en-Y anastomosis after radical total gastrectomy: Review of the literature.

PubMed

Zhou, Youxin; Wang, Fengfeng; Ji, Yong; Lv, Jian

2017-12-01

Postoperative intussusception is an unusual clinical entity and is rarely encountered as a complication following gastrectomy, especially radical total gastrectomy. A 74-year-old woman was admitted to our hospital with complaints of melena and hematemesis. And the endoscopic biopsy confirmed the poorly differentiated adenocarcinoma of the stomach. Radical total gastrectomy with Uncut Roux-en-Y reconstruction was performed. On the third postoperative day (POD3), the patient complained of paroxysmal pain around the umbilicus, accompanied by nausea and vomiting. Retrograde intussusceptions after radical total gastrectomy with Uncut Roux-en-Y reconstruction based on exploratory laparotomy. On POD4, the abdominal computed tomography (CT) showed small bowel dilatation and fluid accumulation in the upper abdominal cavity, as well as a small mass of soft tissue on the left side of the pelvis. Small bowel obstruction was considered, and exploratory laparotomy was performed. Retrograde intussusception started just below the jejunojejunal anastomosis with possible organic lesions, which was subsequently removed. The patient recovered well and was discharged 15 days after the second operation. This case report was written for 3 purposes: to increase awareness of this complication after radical total gastrectomy with Uncut-Roux-en-Y reconstruction; to emphasize early diagnosis through clinical manifestation, physical examination, and auxiliary examination with abdominal CT; and lastly, to emphasize that a reasonable surgical procedure should be performed immediately after diagnosis.

Salt-Sensitive Hypertension: Perspectives on Intrarenal Mechanisms

PubMed Central

Majid, Dewan S.A.; Prieto, Minolfa C.; Navar, L Gabriel

2015-01-01

Salt sensitive hypertension is characterized by increases in blood pressure in response to increases in dietary salt intake and is associated with an enhanced risk of cardiovascular and renal morbidity. Although researchers have sought for decades to understand how salt sensitivity develops in humans, the mechanisms responsible for the increases in blood pressure in response to high salt intake are complex and only partially understood. Until now, scientists have been unable to explain why some individuals are salt sensitive and others are salt resistant. Although a central role for the kidneys in the development of salt sensitivity and hypertension has been generally accepted, it is also recognized that hypertension is of multifactorial origin and a variety of factors can induce, or prevent, blood pressure responsiveness to the manipulation of salt intake. Excess salt intake in susceptible persons may also induce inappropriate central and sympathetic nervous system responses and increase the production of intrarenal angiotensin II, catecholamines and other factors such as oxidative stress and inflammatory cytokines. One key factor is the concomitant inappropriate or paradoxical activation of the intrarenal renin-angiotensin system, by high salt intake. This is reflected by the increases in urinary angiotensinogen during high salt intake in salt sensitive models. A complex interaction between neuroendocrine factors and the kidney may underlie the propensity for some individuals to retain salt and develop salt-dependent hypertension. In this review, we focus mainly on the renal contributions that provide the mechanistic link between chronic salt intake and the development of hypertension. PMID:26028244

Contrast-enhanced ultrasound and computed tomography findings of granulomatosis with polyangiitis presenting with multiple intrarenal microaneurysms: A case report.

PubMed

Kim, Youe Ree; Lee, Young Hwan; Lee, Jong-Ho; Yoon, Kwon-Ha

Granulomatosis with polyangiitis (GPA) is a systemic disorder that affects small- and medium- sized vessels in many organs. Although the kidneys are the second most commonly involved organ in patients with GPA, its manifestation as multiple intrarenal aneurysms is rare. We report an unusual manifestation of GPA with multiple intrarenal microaneurysms, as demonstrated by contrast-enhanced ultrasound and computed tomography. Copyright © 2017 Elsevier Inc. All rights reserved.

[Salt-induced inappropriate augmentation of intrarenal RAAS and its treatment in patients with chronic kidney disease].

PubMed

Konishi, Yoshio

2012-09-01

Focus on the role of the renin-angiotensin-aldosterone system (RAAS) in the pathophysiology of hypertension and renal damage has shifted recently to the role of the local RAAS in the kidneys. Inappropriate augmentation of intrarenal RAAS activity in patients with chronic kidney disease has suggested playing important roles in the development of hypertension and renal injury. In this article, I show the recent findings that salt-induced this augmentation may contribute to the development of salt-sensitive hypertension and play a key role in cardiorenal syndrome (CRS), and that blockade of intrarenal RAAS may be an important strategy for salt-sensitive hypertension and CRS.

Ureteral retrograde brush biopsy

MedlinePlus

Biopsy - brush - urinary tract; Retrograde ureteral brush biopsy cytology; Cytology - ureteral retrograde brush biopsy ... should not be performed in people with a: Urinary tract infection Blockage at or below the biopsy site ...

A case of retrograde intussusception at Roux-en-Y anastomosis 10 years after total gastrectomy: review of the literature.

PubMed

Kitasato, Yuhei; Midorikawa, Ryuta; Uchino, Yoshihiro; Saku, Shuko; Minami, Taizan; Shirahama, Takahisa; Kiyomatsu, Kazumitsu; Okuda, Koji; Akagi, Yoshito; Tanaka, Hiroyuki

2016-12-01

A 63-year-old man, who had undergone total gastrectomy and Roux-en-Y reconstruction for gastric cancer 10 years previously, was admitted to our hospital with complaints of abdominal pain, palpable abdominal tumor, and hematemesis. On admission, the abdominal tenderness was improving and no abdominal tumor was palpable. Mild inflammatory changes and anemia were noted on blood examination. Abdominal computed tomography revealed a tumor with a layered structure in the left abdomen. The patient was diagnosed with intestinal obstruction secondary to intussusception, and surgery was performed. Retrograde intussusception was found at the site of the Y anastomosis. We conducted manual reduction using the Hutchinson procedure. The intestinal color after the reduction was good, and no intestinal resection was required. Postoperative recovery was uneventful, and the patient was discharged 12 days after surgery. Reports of jejunal intussusception after total gastrectomy with Roux-en-Y reconstruction are relatively rare. Here, we report a case of jejunal intussusception after total gastrectomy with Roux-en-Y reconstruction.

Urinary angiotensinogen as a potential biomarker of intrarenal renin-angiotensin system activity in Chinese chronic kidney disease patients.

PubMed

Xu, Z; Xu, B; Xu, C

2015-06-01

Urinary angiotensinogen (AGT) mainly derives from the AGT produced in proximal tubular cells. Evidence exists that supports the correlation between urinary AGT and circulating AGT. To investigate the role of urinary AGT as a potential biomarker of intrarenal renin-angiotensin system activity in Chinese chronic kidney disease (CKD) patients. ELISA-based method used to quantify urinary AGT. Analyzed the relationship between urinary AGT and intrarenal angiotensin II (Ang II) activity in 128 CKD patients. ELISA was applied to measure the urinary and plasma renin activity, AGT, Ang II and aldosterone. Furthermore expression levels of intrarenal renin, AGT, Ang II and Ang II receptor were examined by immunohistochemistry staining (IHCS) in 72 CKD patients undergoing renal biopsy. The logarithmic transformation Log(urinary AGT/UCre) levels showed a normal distribution. Therefore, Log(urinary AGT/UCre) levels were used for the analyses. Average urinary AGT was 2.02 ± 0.55 ng/(mg Cr). Hypertension, urinary protein, urinary Ang II and urinary type IV collagen (Col IV) positively correlated with urinary AGT. Estimated glomerular filtration rate (eGFR), urinary sodium and serum AGT negatively correlated with urinary AGT. Multiple regression analysis indicated that low serum AGT, high urinary protein, urinary Ang II and urinary Col IV correlated significantly with high urinary AGT. We observed positive correlation between urinary AGT and positive IHCS area of AGT, Ang II and Ang II type 1 receptor in renal tissue. These data suggest that urinary AGT might be a potential biomarker of intrarenal Ang II activity in CKD patients.

Low-protein diet supplemented with ketoacids ameliorates proteinuria in 3/4 nephrectomised rats by directly inhibiting the intrarenal renin-angiotensin system.

PubMed

Zhang, Jia-Ying; Yin, Ying; Ni, Li; Long, Quan; You, Li; Zhang, Qian; Lin, Shan-Yan; Chen, Jing

2016-11-01

Low-protein diet plus ketoacids (LPD+KA) has been reported to decrease proteinuria in patients with chronic kidney diseases (CKD). However, the mechanisms have not been clarified. As over-activation of intrarenal renin-angiotensin system (RAS) has been shown to play a key role in the progression of CKD, the current study was performed to investigate the direct effects of LPD+KA on intrarenal RAS, independently of renal haemodynamics. In this study, 3/4 subtotal renal ablated rats were fed 18 % normal-protein diet (Nx-NPD), 6 % low-protein diet (Nx-LPD) or 5 % low-protein diet plus 1 % ketoacids (Nx-LPD+KA) for 12 weeks. Sham-operated rats fed NPD served as controls. The level of proteinuria and expression of renin, angiotensin II (AngII) and its type 1 receptors (AT1R) in the renal cortex were markedly higher in Nx-NPD group than in the sham group. LPD+KA significantly decreased the proteinuria and inhibited intrarenal RAS activation. To exclude renal haemodynamic impact on intrarenal RAS, the serum samples derived from the different groups were added to the culture medium of mesangial cells. It showed that the serum from Nx-NPD directly induced higher expression of AngII, AT1R, fibronectin and transforming growth factor-β1 in the mesangial cells than in the control group. Nx-LPD+KA serum significantly inhibited these abnormalities. Then, proteomics and biochemical detection suggested that the mechanisms underlying these beneficial effects of LPD+KA might be amelioration of the nutritional metabolic disorders and oxidative stress. In conclusion, LPD+KA could directly inhibit the intrarenal RAS activation, independently of renal haemodynamics, thus attenuating the proteinuria in CKD rats.

Popliteal versus tibial retrograde access for subintimal arterial flossing with antegrade-retrograde intervention (SAFARI) technique.

PubMed

Hua, W R; Yi, M Q; Min, T L; Feng, S N; Xuan, L Z; Xing, J

2013-08-01

This study aimed to ascertain differences in benefit and effectiveness of popliteal versus tibial retrograde access in subintimal arterial flossing with the antegrade-retrograde intervention (SAFARI) technique. This was a retrospective study of SAFARI-assisted stenting for long chronic total occlusion (CTO) of TASC C and D superficial femoral lesions. 38 cases had superficial femoral artery lesions (23 TASC C and 15 TASC D). All 38 cases underwent SAFARI-assisted stenting. The ipsilateral popliteal artery was retrogradely punctured in 17 patients. A distal posterior tibial (PT) or dorsalis pedis (DP) artery was retrogradely punctured in 21 patients, and 16 of them were punctured after open surgical exposure. SAFARI technical success was achieved in all cases. There was no significant difference in 1-year primary patency (75% vs. 78.9%, p = .86), secondary patency (81.2% vs. 84.2%, p = .91) and access complications (p = 1.00) between popliteal and tibial retrograde access. There was statistical difference in operation time between popliteal (140.1 ± 28.4 min) and tibial retrograde access with PT/DP punctures after surgical vessel exposure (120.4 ± 23.0 min, p = .04). The SAFARI technique is a safe and feasible option for patients with infrainguinal CTO (TASC II C and D). The PT or DP as the retrograde access after surgical vessel exposure is a good choice when using the SAFARI technique. Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Impaired endogenous nighttime melatonin secretion relates to intrarenal renin-angiotensin system activation and renal damage in patients with chronic kidney disease.

PubMed

Ishigaki, Sayaka; Ohashi, Naro; Isobe, Shinsuke; Tsuji, Naoko; Iwakura, Takamasa; Ono, Masafumi; Sakao, Yukitoshi; Tsuji, Takayuki; Kato, Akihiko; Miyajima, Hiroaki; Yasuda, Hideo

2016-12-01

Activation of the intrarenal renin-angiotensin system (RAS) plays a critical role in the pathophysiology of chronic kidney disease (CKD) and hypertension. The circadian rhythm of intrarenal RAS activation leads to renal damage and hypertension, which are associated with diurnal blood pressure (BP) variation. The activation of intrarenal RAS following reactive oxygen species (ROS) activation, sympathetic hyperactivity and nitric oxide (NO) inhibition leads to the development of renal damage. Melatonin is a hormone regulating the circadian rhythm, and has multiple functions such as anti-oxidant and anti-adrenergic effects and enhancement of NO bioavailability. Nocturnal melatonin concentrations are lower in CKD patients. However, it is not known if impaired endogenous melatonin secretion is related to BP, intrarenal RAS, or renal damage in CKD patients. We recruited 53 CKD patients and conducted 24-h ambulatory BP monitoring. urine was collected during the daytime and nighttime. We investigated the relationship among the melatonin metabolite urinary 6-sulphatoxymelatonin (U-aMT6s), BP, renal function, urinary angiotensinogen (U-AGT), and urinary albumin (U-Alb). Patients' U-aMT6s levels were significantly and negatively correlated with clinical parameters such as renal function, systolic BP, U-AGT, and U-Alb, during both day and night. Multiple regression analyses for U-aMT6s levels were performed using age, gender, renal function, and each parameter (BPs, U-AGT or U-Alb), at daytime and nighttime. U-aMT6s levels were significantly associated with U-AGT (β = -0.31, p = 0.044) and U-Alb (β = -0.25, p = 0.025) only at night. Impaired nighttime melatonin secretion may be associated with nighttime intrarenal RAS activation and renal damage in CKD patients.

Single Balloon Enteroscopy-Assisted Endoscopic Retrograde Cholangiopancreatography in Patients Who Underwent a Gastrectomy with Roux-en-Y Anastomosis: Six Cases from a Single Center.

PubMed

Soh, Jae Seung; Yang, Dong-Hoon; Lee, Sang Soo; Lee, Seohyun; Bae, Jungho; Byeon, Jeong-Sik; Myung, Seung-Jae; Yang, Suk-Kyun

2015-09-01

Patients with altered anatomy such as a Roux-en-Y anastomosis often present with various pancreaticobiliary problems requiring therapeutic intervention. However, a conventional endoscopic approach to the papilla is very difficult owing to the long afferent limb and acute angle of a Roux-en-Y anastomosis. Balloon-assisted enteroscopy can be used for endoscopic retrograde cholangiopancreatography (ERCP) in patients with altered anatomy. We experienced six cases of Roux-en-Y anastomosis with biliary problems, and attempted ERCP using single balloon enteroscopy (SBE). SBE insertion followed by replacement with a conventional endoscope was attempted in five of six patients. The papilla was successfully approached using SBE in all cases. However, therapeutic intervention was completed in only three cases because of poor maneuverability caused by postoperative adhesion. We conclude that in patients with Roux-en-Y anastomosis, the ampulla can be readily accessed with SBE, but longer dedicated accessories are necessary to improve this therapeutic intervention.

Retrograde pyelography predicts retrograde ureteral stenting failure and reduces unnecessary stenting trials in patients with advanced non-urological malignant ureteral obstruction

PubMed Central

Kim, Sung Han; Park, Boram; Joo, Jungnam; Joung, Jae Young; Seo, Ho Kyung; Chung, Jinsoo; Lee, Kang Hyun

2017-01-01

Objective To evaluate predictive factors for retrograde ureteral stent failure in patients with non-urological malignant ureteral obstruction. Materials and methods Between 2005 and 2014, medical records of 284 malignant ureteral obstruction patients with 712 retrograde ureteral stent trials including 63 (22.2%) having bilateral malignant ureteral obstruction were retrospectively reviewed. Retrograde ureteral stent failure was defined as the inability to place ureteral stents by cystoscopy, recurrent stent obstruction within one month, or non-relief of azotemia within one week from the prior retrograde ureteral stent. The clinicopathological parameters and first retrograde pyelographic findings were analyzed to investigate the predictive factors for retrograde ureteral stent failure and conversion to percutaneous nephrostomy in multivariate analysis with a statistical significance of p < 0.05. Results Retrograde ureteral stent failure was detected in 14.1% of patients. The mean number of retrograde ureteral stent placements and indwelling duration of the ureteral stents were 2.5 ± 2.6 times and 8.6 ± 4.0 months, respectively. Multivariate analyses identified several specific RGP findings as significant predictive factors for retrograde ureteral stent failure (p < 0.05). The significant retrograde pyelographic findings included grade 4 hydronephrosis (hazard ratio 4.10, 95% confidence interval 1.39–12.09), irreversible ureteral kinking (hazard ratio 2.72, confidence interval 1.03–7.18), presence of bladder invasion (hazard ratio 4.78, confidence interval 1.81–12.63), and multiple lesions of ureteral stricture (hazard ratio 3.46, confidence interval 1.35–8.83) (p < 0.05). Conclusion Retrograde pyelography might prevent unnecessary and ineffective retrograde ureteral stent trials in patients with advanced non-urological malignant ureteral obstruction. PMID:28931043

A retrograde object near Jupiter's orbit

NASA Astrophysics Data System (ADS)

Connors, M.; Wiegert, P.

2018-02-01

Asteroid 2007 VW266 is among the rare objects with a heliocentric retrograde orbit, and its semimajor axis is within a Hill sphere radius of that of Jupiter. This raised the interesting possibility that it could be in co-orbital retrograde resonance with Jupiter, a second "counter-orbital" object in addition to recently discovered 2015 BZ509. We find instead that the object is in 13/14 retrograde mean motion resonance (also referred to as 13/-14). The object is shown to have entered its present orbit about 1700 years ago, and it will leave it in about 8000 years, both through close approach to Jupiter. Entry and exit states both avoid 1:1 retrograde resonance, but the retrograde nature is preserved. The temporary stable state is due to an elliptic orbit with high inclination keeping nodal passages far from the associated planet. We discuss the motion of this unusual object based on modeling and theory, and its observational prospects.

Outcomes of Endoscopic Retrograde Cholangiopancreatography (ERCP) and Sphincterotomy for Suspected Sphincter of Oddi Dysfunction (SOD) Post Roux-En-Y Gastric Bypass.

PubMed

Lim, Chin Hong; Jahansouz, Cyrus; Freeman, Martin L; Leslie, Daniel B; Ikramuddin, Sayeed; Amateau, Stuart K

2017-10-01

Sphincter of Oddi dysfunction (SOD) is thought to be a cause of chronic abdominal pain post Roux-en-Y gastric bypass, and current practice of performing endoscopic retrograde cholangiopancreatography (ERCP) with or without sphincterotomy is not supported by evidence. In addition to the complexity and risks of the procedure in patients with Roux-en-Y anatomy, the outcomes are uncertain and debatable. We performed a retrospective review and analysis of post-gastric bypass patients who had undergone ERCP with sphincterotomy to determine the effectiveness in patients with suspected SOD. Over a period of 5 years at the University of Minnesota, we retrospectively reviewed a prospectively collected database of a cohort of patients whom had a previous Roux-en-Y gastric bypass and whom had a subsequent ERCP for suspected SOD. Patients were categorized by modified Milwaukee classification, and outcomes were evaluated by patients' self-reporting of symptoms at follow-up. We identified 50 patients who underwent laparoscopic-assisted gastrostomy for endoscopic retrograde cholangiopancreatography post Roux-en-Y gastric bypass over the study period. Within this group, 35 patients (70%) were suspected to have SOD. Nine patients (25.7%) were classified as type I, 19 patients (54.3%) type II, and seven patients (20%) type III. Thirty-four patients (97.1%) had biliary sphincterotomy, and 17 patients (48.6%) had both biliary and pancreatic sphincterotomy. Fourteen (40%) had repeated ERCP. At median follow-up of 11.5 months, type I SOD had two responders (25%), type II had nine responders (52.9%), and type III had one responder (14.3%). A subgroup analysis did not show significant differences in improvement of symptoms between patients whom had single versus repeated ERCP or biliary sphincterotomy alone versus both biliary and pancreatic sphincterotomy. Three patients (9%) had post-ERCP pancreatitis. SOD in patients post Roux-en-Y gastric bypass is complex due to multiple confounding

First case report of staghorn calculi successfully removed by mini-endoscopic combined intrarenal surgery in a 2-year-old boy.

PubMed

Taguchi, Kazumi; Hamamoto, Shuzo; Okada, Atsushi; Mizuno, Kentaro; Tozawa, Keiichi; Hayashi, Yutaro; Kohri, Kenjiro; Yasui, Takahiro

2015-10-01

Less-invasive therapy for pediatric urolithiasis is available due to the miniaturization of equipment and improved optics; however, surgical treatment strategies, especially for large calculi, remain controversial. We describe here our experience of treating a 2-year-old boy with left renal staghorn calculi with a single session of mini-endoscopic combined intrarenal surgery in the prone split-leg position with pre-ureteral stenting and the directional enhanced flow imaging ultrasound technique. This is the first report of successful pediatric mini-endoscopic combined intrarenal surgery without any major complications. We believe this technique provides an important therapeutic option for large renal calculus in pediatric patients. © 2015 The Japanese Urological Association.

ECIRS (Endoscopic Combined Intrarenal Surgery) in the Galdakao-modified supine Valdivia position: a new life for percutaneous surgery?

PubMed

Cracco, Cecilia Maria; Scoffone, Cesare Marco

2011-12-01

Percutaneous nephrolithotomy (PNL) is still the gold-standard treatment for large and/or complex renal stones. Evolution in the endoscopic instrumentation and innovation in the surgical skills improved its success rate and reduced perioperative morbidity. ECIRS (Endoscopic Combined IntraRenal Surgery) is a new way of affording PNL in a modified supine position, approaching antero-retrogradely to the renal cavities, and exploiting the full array of endourologic equipment. ECIRS summarizes the main issues recently debated about PNL. The recent literature regarding supine PNL and ECIRS has been reviewed, namely about patient positioning, synergy between operators, procedures, instrumentation, accessories and diagnostic tools, step-by-step standardization along with versatility of the surgical sequence, minimization of radiation exposure, broadening to particular and/or complex patients, limitation of post-operative renal damage. Supine PNL and ECIRS are not superior to prone PNL in terms of urological results, but guarantee undeniable anesthesiological and management advantages for both patient and operators. In particular, ECIRS requires from the surgeon a permanent mental attitude to synergy, standardized surgical steps, versatility and adherence to the ongoing clinical requirements. ECIRS can be performed also in particular cases, irrespective to age or body habitus. The use of flexible endoscopes during ECIRS contributes to minimizing radiation exposure, hemorrhagic risk and post-PNL renal damage. ECIRS may be considered an evolution of the PNL procedure. Its proposal has the merit of having triggered the critical analysis of the various PNL steps and of patient positioning, and of having transformed the old static PNL into an updated approach.

Double-balloon endoscopy for retrograde cholangiography in patients with choledochojejunostomy and Roux-en-Y reconstruction.

PubMed

Pohl, J; May, A; Aschmoneit, I; Ell, C

2009-02-01

Choledochojejunal anastomoses with Roux-en-Y reconstruction excludes the biliary tract from conventional endoscopic retrograde cholangiography (ERC) with standard endoscopes due to the length of the interposed small bowel segment. Double-balloon enteroscopy (DBE) facilitates deep insertion into the small bowel and may be used to perform ERC in these patients. In the present case series we report our experience with diagnostic and therapeutic double-balloon ERC in patients with choledochojejunostomy to a long Roux-en-Y loop previously unavailable for standard length endoscopes. Between December 2004 and May 2008 15 patients (mean age: 60.2 years) with choledochojejunal anastomosis underwent a total of 25 DBE-ERC procedures. Cannulation of the bile ducts was achieved in 22 / 25 procedures (84 %). Twenty-one therapeutic interventions, including stone removal, biliary duct dilation, stent placement and removal of previously placed stents were performed during 16 procedures in 8 patients. The mean total duration time of the procedures was 74.6 +/- 25.0 minutes. Postinterventional self-limiting fever occurred after 4 procedures in 3 patients with cholangitis. After therapeutic interventions all patients had a significant drop of bilirubin levels and all except one patient were free of complaints (follow-up 10.4 +/- 8.6 months). The DBE system permits diagnostic and therapeutic ERC in surgically modified anatomy, previously unavailable for endoluminal access. In our experience this procedure is safe and has a high success rate with a favourable patient outcome.

Retrograde motion of a rolling disk

NASA Astrophysics Data System (ADS)

Borisov, A. V.; Kilin, A. A.; Karavaev, Yu L.

2017-12-01

This paper presents results of theoretical and experimental research explaining the retrograde final-stage rolling of a disk under certain relations between its mass and geometric parameters. Modifying the no-slip model of a rolling disk by including viscous rolling friction provides a qualitative explanation for the disk’s retrograde motion. At the same time, the simple experiments described in the paper completely reject the aerodynamical drag torque as a key reason for the retro-grade motion of a disk considered, thus disproving some recent hypotheses.

Comparison of double-balloon and single-balloon enteroscope for therapeutic endoscopic retrograde cholangiography after Roux-en-Y small bowel surgery.

PubMed

De Koning, Michael; Moreels, Tom G

2016-08-22

Roux-en-Y reconstructive surgery excludes the biliopancreatic system from conventional endoscopic access. Balloon-assisted enteroscopy allows therapeutic endoscopic retrograde cholangiopancreatography (ERCP) in these patients, avoiding rescue surgery. The objective of the current study is to compare success and complication rate of double-balloon (DBE) and single-balloon enteroscope (SBE) to perform ERCP in Roux-en-Y patients. Seventy three Roux-en-Y patients with suspected biliary tract pathology underwent balloon-assisted enteroscopy in a tertiary-care center. Retrospective analysis of 95 consecutive therapeutic ERCP procedures was performed to define and compare success and complication rate of DBE and SBE. Male-female ratio was 28/45 with a mean age of 58 ± 2 years. 30 (32 %) procedures were performed with DBE and 65 (68 %) with SBE. Overall ERCP success rate was 73 % for DBE and 75 % for SBE (P = 0.831). Failure was due to inability to reach or cannulate the intact papilla or bilioenteric anastomosis. Success rate was significantly higher when performed at the bilioenteric anastomosis (80 % success in 56 procedures) or at the intact papilla in short-limb Roux-en-Y (80 % in 15 procedures) as compared to the intact papilla in long-limb (58 % in 24 procedures; P = 0.040). Adverse event rates were 10 % (DBE) and 8 % (SBE) (P = 0.707) and mostly dealt with conservatively. ERCP after Roux-en-Y altered small bowel anatomy is feasible and safe using both DBE and SBE. Both techniques are equally competent with high success rates and acceptable adverse events rates. ERCP at the level of the intact papilla in long limb Roux-en-Y is less successful as compared to short-limb or bilioenteric anastomosis.

Modeling electric bicycle's lane-changing and retrograde behaviors

NASA Astrophysics Data System (ADS)

Tang, Tie-Qiao; Luo, Xiao-Feng; Zhang, Jian; Chen, Liang

2018-01-01

Recently, electric bicycle (EB) has been one important traffic tool due to its own merits. However, EB's motion behaviors (especially at a signalized/non-signalized intersection) are more complex than those of vehicle since it always has lane-changing and retrograde behaviors. In this paper, we propose a model to explore EB's lane-changing and retrograde behaviors on a road with a signalized intersection. The numerical results indicate that the proposed model can qualitatively describe each EB's lane-changing and retrograde behaviors near a signalized intersection, and that lane-changing and retrograde behaviors have prominent impacts on the signalized intersection (i.e., prominent jams and congestions occur). The above results show that EB should be controlled as a vehicle, i.e., lane-changing and retrograde behaviors at a signalized intersection should strictly be prohibited to improve the operational efficiency and traffic safety at the signalized intersection.

Doppler-guided retrograde catheterization system

NASA Astrophysics Data System (ADS)

Frazin, Leon J.; Vonesh, Michael J.; Chandran, Krishnan B.; Khasho, Fouad; Lanza, George M.; Talano, James V.; McPherson, David D.

1991-05-01

The purpose of this study was to investigate a Doppler guided catheterization system as an adjunctive or alternative methodology to overcome the disadvantages of left heart catheterization and angiography. These disadvantages include the biological effects of radiation and the toxic and volume effects of iodine contrast. Doppler retrograde guidance uses a 20 MHz circular pulsed Doppler crystal incorporated into the tip of a triple lumen multipurpose catheter and is advanced retrogradely using the directional flow information provided by the Doppler waveform. The velocity detection limits are either 1 m/second or 4 m/second depending upon the instrumentation. In a physiologic flow model of the human aortic arch, multiple data points revealed a positive wave form when flow was traveling toward the catheter tip indicating proper alignment for retrograde advancement. There was a negative wave form when flow was traveling away from the catheter tip if the catheter was in a branch or bent upon itself indicating improper catheter tip position for retrograde advancement. In a series of six dogs, the catheter was able to be accurately advanced from the femoral artery to the left ventricular chamber under Doppler signal guidance without the use of x-ray. The potential applications of a Doppler guided retrograde catheterization system include decreasing time requirements and allowing safer catheter guidance in patients with atherosclerotic vascular disease and suspected aortic dissection. The Doppler system may allow left ventricular pressure monitoring in the intensive care unit without the need for x-ray and it may allow left sided contrast echocardiography. With pulse velocity detection limits of 4 m/second, this system may allow catheter direction and passage into the aortic root and left ventricle in patients with aortic stenosis. A modification of the Doppler catheter may include transponder technology which would allow precise catheter tip localization once the

Surgical planning and manual image fusion based on 3D model facilitate laparoscopic partial nephrectomy for intrarenal tumors.

PubMed

Chen, Yuanbo; Li, Hulin; Wu, Dingtao; Bi, Keming; Liu, Chunxiao

2014-12-01

Construction of three-dimensional (3D) model of renal tumor facilitated surgical planning and imaging guidance of manual image fusion in laparoscopic partial nephrectomy (LPN) for intrarenal tumors. Fifteen patients with intrarenal tumors underwent LPN between January and December 2012. Computed tomography-based reconstruction of the 3D models of renal tumors was performed using Mimics 12.1 software. Surgical planning was performed through morphometry and multi-angle visual views of the tumor model. Two-step manual image fusion superimposed 3D model images onto 2D laparoscopic images. The image fusion was verified by intraoperative ultrasound. Imaging-guided laparoscopic hilar clamping and tumor excision was performed. Manual fusion time, patient demographics, surgical details, and postoperative treatment parameters were analyzed. The reconstructed 3D tumor models accurately represented the patient's physiological anatomical landmarks. The surgical planning markers were marked successfully. Manual image fusion was flexible and feasible with fusion time of 6 min (5-7 min). All surgeries were completed laparoscopically. The median tumor excision time was 5.4 min (3.5-10 min), whereas the median warm ischemia time was 25.5 min (16-32 min). Twelve patients (80 %) demonstrated renal cell carcinoma on final pathology, and all surgical margins were negative. No tumor recurrence was detected after a media follow-up of 1 year (3-15 months). The surgical planning and two-step manual image fusion based on 3D model of renal tumor facilitated visible-imaging-guided tumor resection with negative margin in LPN for intrarenal tumor. It is promising and moves us one step closer to imaging-guided surgery.

Implementation of Ultramini Percutaneous Nephrolithotomy for Treatment of 2-3 cm Kidney Stones: A Preliminary Report.

PubMed

Shah, Arvind K; Xu, Kewei; Liu, Hao; Huang, Hai; Lin, Tianxin; Bi, Liangkuan; Jinli, Han; Fan, Xinxiang; Shrestha, Rujan; Huang, Jian

2015-11-01

Miniatured percutaneous nephrolithotomy (PCNL) techniques such as micro-PCNL (microperc) and ultramini-PCNL (UMP) are usually indicated for renal stones <2 cm. We present our preliminary report of treating patients with 2 to 3 cm renal stones using UMP in a semisupine combined lithotomy position associated with a retrograde ureteral access sheath (UAS). From April 2013 to January 2014, we implemented 13F UMP for 22 patients with renal stones that were 2 to 3 cm with the patient positioned in a 45-degree semisupine combined lithotomy position. A retrograde 9.5/11.5F UAS was placed for maintaining low intrarenal pressure and debris drainage. Flexible ureteroscopy was used for stones inaccessible through the primary percutaneous tract in two patients. A 200-μ holmium laser was used for stone disintegration. Intrapelvic pressure was measured using an open end 5F ureteral catheter inserted through the UAS. All 22 cases were completed successfully. The mean preoperative stone size was 26.6 ± 4.7 mm (range 21-32 mm), mean operative time was 85.7 ± 18.0 minutes (range 47-112 min), and mean hemoglobin drop was 1.2 ± 0.3 g/dL (range 0.5-2.2 g/dL). Intrapelvic pressure during the surgical procedure ranged 5 to 10 cm H2O. The mean hospital stay was 3.1 ± 1.8 days (range 2-5 d). Complete stone clearance was 18/22 (81.8%) with solo UMP and 20/22 (90.9%) when associated with retrograde intrarenal surgery (RIRS). No major intra- or postoperative complications occurred. Implementation of UMP for the treatment of patients with renal stones 2-3 cm is feasible and safe. The procedure is less invasive and has a faster recovery period. Intraoperative retrograde UAS decreases intrarenal pressure, facilitates removal of stone fragments, and also allows simultaneous RIRS for stones in an inaccessible calix.

Dynamics of the retrograde 1/1 mean motion resonance

NASA Astrophysics Data System (ADS)

Huang, Yukun; Li, Miao; Li, Junfeng; Gong, Shengping

2018-04-01

Mean motion resonances are very common in the solar system. Asteroids in mean motion resonances with giant planets have been studied for centuries. But it was not until recently that asteroids in retrograde mean motion resonances with Jupiter and Saturn were discovered. The newly discovered asteroid, 2015 BZ509 is confirmed to be the first asteroid in retrograde 1:1 mean motion resonance (or retrograde co-orbital resonance) with Jupiter, which gives rise to our interests in its unique resonant dynamics. In this study, we thoroughly investigate the phase-space structure of the retrograde 1:1 resonance within the framework of the circular restricted three-body problem. We begin by constructing a simple integrable approximation for the planar retrograde resonance with the Hamiltonian approach and show that the variables definition of the retrograde resonance is very different to the prograde one. When it comes to the disturbing function, we abandon the classical series expansion approach, whereas numerically carry out the averaging process on the disturbing function in closed form. The phase portrait of the retrograde 1:1 resonance is depicted with the level curves of the averaged Hamiltonian. We find that the topological structure of phase space for the retrograde 1:1 resonance is very different to other resonances, due to the consistent existence of the collision separatrix. And the surprising bifurcation of equilibrium point around 180° (i.e., the apocentric libration center) has never been found in any other mean motion resonances before. We thoroughly analyze the novel apocentric librations and find that close encounter with the planet does not always lead to the disruption of a stable apocentric libration. Afterwards, we examine the Kozai dynamics inside the mean motion resonance with the similar Hamiltonian approach and explain why the exact resonant point does not exist in the 3D retrograde 1:1 resonance model.

Antibody-Mediated Inhibition of Ricin Toxin Retrograde Transport

PubMed Central

Yermakova, Anastasiya; Klokk, Tove Irene; Cole, Richard; Sandvig, Kirsten; Mantis, Nicholas J.

2014-01-01

ABSTRACT Ricin is a member of the ubiquitous family of plant and bacterial AB toxins that gain entry into the cytosol of host cells through receptor-mediated endocytosis and retrograde traffic through the trans-Golgi network (TGN) and endoplasmic reticulum (ER). While a few ricin toxin-specific neutralizing monoclonal antibodies (MAbs) have been identified, the mechanisms by which these antibodies prevent toxin-induced cell death are largely unknown. Using immunofluorescence confocal microscopy and a TGN-specific sulfation assay, we demonstrate that 24B11, a MAb against ricin’s binding subunit (RTB), associates with ricin in solution or when prebound to cell surfaces and then markedly enhances toxin uptake into host cells. Following endocytosis, however, toxin-antibody complexes failed to reach the TGN; instead, they were shunted to Rab7-positive late endosomes and LAMP-1-positive lysosomes. Monovalent 24B11 Fab fragments also interfered with toxin retrograde transport, indicating that neither cross-linking of membrane glycoproteins/glycolipids nor the recently identified intracellular Fc receptor is required to derail ricin en route to the TGN. Identification of the mechanism(s) by which antibodies like 24B11 neutralize ricin will advance our fundamental understanding of protein trafficking in mammalian cells and may lead to the discovery of new classes of toxin inhibitors and therapeutics for biodefense and emerging infectious diseases. PMID:24713323

Retrograde adsorption isotherms: an impossible fact?

PubMed

Helfferich, Friedrich G

2005-06-24

"Retrograde" adsorption isotherms have been reported, but seem to violate thermodynamics and would cause concentration steps to migrate against the direction of fluid-phase flow. In general, what appears to be retrograde behavior is caused by one or more additional, uncontrolled variables. This is illustrated with adsorption of sulfonate on a weak-acid ion exchanger, where adsorption is accompanied by partial conversion of the ion exchanger to the sodium form.

Identification of the main retrogradation-related properties of rice starch.

PubMed

Lian, Xijun; Kang, Haiqi; Sun, Haibo; Liu, Lizeng; Li, Lin

2015-02-11

The retrogradation of rice in shelf life is the biggest barrier to the industrial production of traditional foods using rice as material. Many rice breeders have tried their best to screen low-retrogradation rice cultivars without a specific indicator. To identify the main retrogradation-related properties of rice, the starch, amylose, and amylopectin from 16 rice cultivars were extracted from rice powder and their physicochemical properties, such as visible absorbance, infrared, average molecule weight (amylopectin), chain-length distribution (amylopectin), X-ray diffraction, and differential scanning calorimetry, were determined. The correlation between starch retrogradation rates and those physicochemical properties was investigated. The results show that a significant positive correlation (R(2) = 0.85; r = 0.926; p < 0.01) exists only between proportions of the chains [degree of polymerization (DP) > 10] in amylopectin and the retrogradation rates of different rice starches. The findings in the paper offer a shortcut for rice breeders to screen cultivars with a low retrogradation rate. Because the genes related to the branching enzyme control the DP of amylopectin, they can be exploited as molecular markers to screen low-retrogradation rice cultivars.

Dynamic Portrait of the Retrograde 1:1 Mean Motion Resonance

NASA Astrophysics Data System (ADS)

Huang, Yukun; Li, Miao; Li, Junfeng; Gong, Shengping

2018-06-01

Asteroids in mean motion resonances with giant planets are common in the solar system, but it was not until recently that several asteroids in retrograde mean motion resonances with Jupiter and Saturn were discovered. A retrograde co-orbital asteroid of Jupiter, 2015 BZ509 is confirmed to be in a long-term stable retrograde 1:1 mean motion resonance with Jupiter, which gives rise to our interests in its unique resonant dynamics. In this paper, we investigate the phase-space structure of the retrograde 1:1 resonance in detail within the framework of the circular restricted three-body problem. We construct a simple integrable approximation for the planar retrograde resonance using canonical contact transformation and numerically employ the averaging procedure in closed form. The phase portrait of the retrograde 1:1 resonance is depicted with the level curves of the averaged Hamiltonian. We thoroughly analyze all possible librations in the co-orbital region and uncover a new apocentric libration for the retrograde 1:1 resonance inside the planet’s orbit. We also observe the significant jumps in orbital elements for outer and inner apocentric librations, which are caused by close encounters with the perturber.

The inherent catastrophic traps in retrograde CTO PCI.

PubMed

Wu, Eugene B; Tsuchikane, Etsuo

2018-05-01

When we learn to drive, our driving instructor tells us how to check the side mirror and turn your head to check the blind spot before changing lanes. He tells us how to stop at stop signs, how to drive in slippery conditions, the safe stopping distances, and these all make our driving safe. Similarly, when we learn PCI, our mentors teach us to seat the guiding catheter co-axially, to wire the vessel safely, to deliver balloon and stents over the wire, to watch the pressure of the guiding, in order that we perform PCI safely and evade complications. In retrograde CTO PCI, there is no such published teaching. Also many individual mentors have not had the wide experience to see all the possible complications of retrograde CTO PCI and, therefore, may not be able to warn their apprentice. As the number of retrograde procedures increase worldwide, there is a corresponding increase in catastrophic complications, many of which, we as experts, can see are easily avoidable. To breach this gap in knowledge, this article describes 12 commonly met inherent traps in retrograde CTO PCI. They are inherent because by arranging our equipment in the manner to perform retrograde CTO PCI, these complications are either induced directly or happen easily. We hope this work will enhance safety of retrograde CTO PCI and avoid many catastrophic complications for our readers and operators. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Criteria for retrograde rotation of accreting black holes

NASA Astrophysics Data System (ADS)

Mikhailov, A. G.; Piotrovich, M. Yu; Gnedin, Yu N.; Natsvlishvili, T. M.; Buliga, S. D.

2018-06-01

Rotating supermassive black holes produce jets and their origin is connected to the magnetic field that is generated by accreting matter flow. There is a point of view that electromagnetic fields around rotating black holes are brought to the hole by accretion. In this situation the prograde accreting discs produce weaker large-scale black hole threading magnetic fields, implying weaker jets than in retrograde regimes. The basic goal of this paper is to find the best candidates for retrograde accreting systems in observed active galactic nuclei. We show that active galactic nuclei with low Eddington ratio are really the best candidates for retrograde systems. This conclusion is obtained for kinetically dominated Fanaroff-Riley class II radio galaxies, flat-spectrum radio-loud narrow-line Seyfert I galaxies and a number of nearby galaxies. Our conclusion is that the best candidates for retrograde systems are the noticeable population of active galactic nuclei in the Universe. This result corresponds to the conclusion that in the merging process the interaction of merging black holes with a retrograde circumbinary disc is considerably more effective for shrinking the binary system.

Efficacy of treatment with pseudoephedrine in men with retrograde ejaculation.

PubMed

Shoshany, O; Abhyankar, N; Elyaguov, J; Niederberger, C

2017-07-01

The use of pseudoephedrine, an alpha agonist, for the treatment of retrograde ejaculation is well-known, however, there is no clear consensus from the literature regarding its efficacy and treatment protocol. We evaluated the efficacy of pseudoephedrine treatment in patients with retrograde ejaculation, utilizing a yet undescribed short-period treatment protocol. Twenty men were medically treated with pseudoephedrine for retrograde ejaculation between January 2010 and May 2016 (12 with complete retrograde ejaculation and 8 with partial retrograde ejaculation). All patients had a semen analysis and post-ejaculatory urinalysis before and after treatment. The treatment protocol consisted of 60 mg of pseudoephedrine every 6 h on the day before semen analysis and two more 60 mg doses on the day of the semen analysis. Diabetes was the most common etiology for complete retrograde ejaculation (60%), whereas an idiopathic cause was the most common etiology for partial retrograde ejaculation (82%). Of the 12 complete retrograde ejaculation patients treated with pseudoephedrine prior to semen analysis, 7 (58.3%) recovered spermatozoa in the antegrade ejaculate, with a mean total sperm count of 273.5 ± 172.5 million. Of the eight patients with partial retrograde ejaculation, five (62.5%) had a ≥50% increase in the antegrade total sperm count. In this group, the mean total sperm count increased from 26.9 ± 8.5 million before treatment to 84.2 ± 24.6 million after treatment, whereas the percentage of spermatozoa in the urine declined from 43.2 ± 9% to 17 ± 10%, respectively (both p < 0.05). Overall, in men with retrograde ejaculation treated with a pseudoephedrine regimen prior to ejaculation, some improvement in seminal parameters occurred in 14 (70%) patients, with 10 patients (38.5% of all patients) achieving antegrade total sperm counts over 39 million. © 2017 American Society of Andrology and European Academy of Andrology.

Neurexin and Neuroligin Mediate Retrograde Synaptic Inhibition in C. elegans

PubMed Central

Hu, Zhitao; Hom, Sabrina; Kudze, Tambudzai; Tong, Xia-Jing; Choi, Seungwon; Aramuni, Gayane; Zhang, Weiqi; Kaplan, Joshua M.

2013-01-01

The synaptic adhesion molecules Neurexin and Neuroligin alter the development and function of synapses and are linked to autism in humans. We find that C. elegans Neurexin (NRX-1) and Neuroligin (NLG-1) mediate a retrograde synaptic signal that inhibits neurotransmitter release at neuromuscular junctions. Retrograde signaling was induced in mutants lacking a muscle microRNA (miR-1) and was blocked in mutants lacking NLG-1 or NRX-1. Release was rapid and abbreviated when the retrograde signal was on whereas release was slow and prolonged when retrograde signaling was blocked. The retrograde signal adjusted release kinetics by inhibiting exocytosis of synaptic vesicles (SVs) that are distal to the site of calcium entry. Inhibition of release was mediated by increased pre-synaptic levels of Tomosyn, an inhibitor of SV fusion. PMID:22859820

Effects of protein in wheat flour on retrogradation of wheat starch.

PubMed

Xijun, Lian; Junjie, Guo; Danli, Wang; Lin, Li; Jiaran, Zhu

2014-08-01

Albumins, globulins, gliadins, and glutenins were isolated from wheat flour and the effects of those proteins on retrogradation of wheat starch were investigated. The results showed that only glutenins retarded retrogradation of wheat starch and other 3 proteins promoted it. The results of IR spectra proved that no S-S linkage formed during retrogradation of wheat starch blended with wheat proteins. Combination of wheat starch and globulins or gliadins through glucosidic bonds hindered the hydrolysis of wheat starch by α-amylase. The melting peak temperatures of retrograded wheat starch attached to different proteins were 128.46, 126.14, 132.03, 121.65, and 134.84 °C for the control with no protein, albumins, glutenins, globulins, gliadins groups, respectively, and there was no second melting temperature for albumins group. Interaction of wheat proteins and starch in retrograded wheat starch greatly decreased the endothermic enthalpy (△H) of retrograded wheat starch. Retrograded wheat starch bound to gliadins might be a new kind of resistant starch based on glycosidic bond between starch and protein. © 2014 Institute of Food Technologists®

How long will asteroids on retrograde orbits survive?

NASA Astrophysics Data System (ADS)

Kankiewicz, Paweł; Włodarczyk, Ireneusz

2018-05-01

Generally, a common scenario for the origin of minor planets with high orbital inclinations does not exist. This applies especially to objects whose orbital inclinations are much greater than 90° (retrograde asteroids). Since the discovery of Dioretsa in 1999, approximately 100 small bodies now are classified as retrograde asteroids. A small number of them were reclassified as comets, due to cometary activity. There are only 25 multi-opposition retrograde asteroids, with a relatively large number of observations and well-determined orbits. We studied the orbital evolution of numbered and multi-opposition retrograde asteroids by numerical integration up to 1 Gy forward and backward in time. Additionally, we analyzed the propagation of orbital elements with the observational errors, determined dynamical lifetimes and studied their chaotic properties. Conclusively, we obtained quantitative parameters describing the long-term stability of orbits relating to the past and the future. In turn, we were able to estimate their lifetimes and how long these objects will survive in the Solar System.

Complications of retrograde balloon cautery endopyelotomy.

PubMed

Schwartz, B F; Stoller, M L

1999-11-01

Adult ureteropelvic junction obstruction is increasingly managed with endoscopic techniques. Retrograde balloon cautery endopyelotomy is quick, requires minimal hospital stay and allows most patients a rapid return to work. The complication rate of retrograde balloon cautery endopyelotomy ranges from 13 to 34%, with vascular injury in 0 to 16% of patients. We report 5 uncommon complications, including 4 vascular injuries, that clinicians should be familiar with when using this technique. We reviewed 52 retrograde endoscopic endopyelotomy procedures performed during a 5-year period. There were 5 uncommon complications. Accessory lower pole renal artery injuries occurred in 3 patients, 1 of whom presented 12 days after endopyelotomy. Embolization was successfully performed in all 3 cases and none had subsequent hypertension. In 1 case a right ovarian vein laceration was not evident on preoperative or postoperative angiography. Emergency post-embolization abdominal exploration revealed a 2 mm. injury to the right ovarian vein before entering the right renal vein close to the ureteropelvic junction incision. Nephrectomy and ovarian vein ligature were curative. In 1 case the electrocautery wire broke intracorporeally after firing, resulting in a bobby pin-like configuration. Successful removal was accomplished by twisting the catheter and wrapping the wire around the tip, enabling atraumatic removal. Retrograde balloon cautery endopyelotomy is an emerging technology with potential adverse outcomes. The complications we noted are complex and potentially life threatening. Awareness of these complications may help avoid poor outcomes and expedite appropriate treatment.

Acute eprosartan-induced intrarenal vasodilation in hypertensive humans is not influenced by dietary sodium intake or angiotensin II co-infusion.

PubMed

van Twist, Daan J L; Houben, Alfons J H M; de Leeuw, Peter W; Kroon, Abraham A

2016-08-01

Angiotensin II (Ang II) is thought to play an important role in the development of hypertension. Nevertheless, knowledge on the angiotensin II type-1-receptors (AT1Rs) in the hypertensive kidney and the influence of sodium intake and renin-angiotensin system activity on intrarenal AT1R blockade is scarce. To improve our understanding of renal AT1Rs in hypertensive patients, we studied the effects of acute, local administration of AT1R-blocker eprosartan in kidneys of patients with essential hypertension (off medication). In 73 hypertensive patients who were scheduled for diagnostic renal angiography, we measured renal blood flow (Xenon washout method) before and during intrarenal infusion of two incremental doses of eprosartan (3 and 10 μg/kg/min for 15 min per dose). We hypothesized that the vasodilatory effects of eprosartan would be enhanced by low sodium intake and would be reduced during Ang II co-infusion. Therefore, we allocated the patients to either a high or a low sodium diet and coinfused Ang II (1 ng/kg/min) in a subgroup. Eprosartan infusion resulted in intrarenal vasodilation in all groups. No differences in the magnitude of this effect were found between the groups. No correlation was found between 24-h urinary sodium excretion (a proxy for dietary sodium intake) and the effect of eprosartan. Eprosartan-induced vasodilation is not influenced by sodium intake and/or co-infusion of Ang II. These rather unexpected findings could be explained by differences between circulating and tissue Ang II levels, variations in AT1R expression, and/or stimulation of other vasodilatory pathways.

Physiologic responses to forward and retrograde simulated stair stepping.

PubMed

Ryan, P T; Plowman, S A; Ball, T E; Looney, M A

1994-07-01

This study compared the physiologic responses to forward and retrograde simulated stair stepping on the StairMaster 4000 PT. Twenty male subjects (mean age 23.65 +/- 1.63 years) volunteered for this study. Subjects completed a practice trial of 6 minutes of both forward and retrograde stepping at Level 5. Each experimental trial was divided into four 3-minute stages: Level 3, Level 5, Level 7, and Level 9. Heart rate, blood pressure, and rating of perceived exertion (RPE) were recorded during the second minute of each stage. Expired gases were analyzed and averaged over the last 2 minutes of each stage. Caloric expenditure and delta efficiency were later calculated. Data were analyzed using a 2 x 4 ANOVA (direction by level) and 2 x 3 ANOVA (for delta efficiency). Compared to forward responses, retrograde heart rates were significantly higher at Levels 7 and 9 (p < 0.01). Retrograde responses for RPE, metabolic equivalents (METS), and caloric expenditure were significantly higher at (p < 0.01) Levels 5, 7, and 9 when compared to forward responses. However, the results of this study show that these differences between forward and retrograde stepping are not practically meaningful.

The 'SAFARI' Technique Using Retrograde Access Via Peroneal Artery Access

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhuang, Kun Da, E-mail: zkunda@gmail.com; Tan, Seck Guan; Tay, Kiang Hiong

2012-08-15

The 'SAFARI' technique or subintimal arterial flossing with antegrade-retrograde intervention is a method for recanalisation of chronic total occlusions (CTOs) when subintimal angioplasty fails. Retrograde access is usually obtained via the popliteal, distal anterior tibial artery (ATA)/dorsalis pedis (DP), or distal posterior tibial artery (PTA). Distal access via the peroneal artery has not been described and has a risk of continued bleeding, leading to compartment syndrome due to its deep location. We describe our experience in two patients with retrograde access via the peroneal artery and the use of balloon-assisted hemostasis for these retrograde punctures. This approach may potentially givemore » more options for endovascular interventions in lower limb CTOs.« less

Independent predictors of retrograde failure in CTO-PCI after successful collateral channel crossing.

PubMed

Suzuki, Yoriyasu; Muto, Makoto; Yamane, Masahisa; Muramatsu, Toshiya; Okamura, Atsunori; Igarashi, Yasumi; Fujita, Tsutomu; Nakamura, Shigeru; Oida, Akitsugu; Tsuchikane, Etsuo

2017-07-01

To evaluate factors for predicting retrograde CTO-PCI failure after successful collateral channel crossing. Successful guidewire/catheter collateral channel crossing is important for the retrograde approach in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). A total of 5984 CTO-PCI procedures performed in 45 centers in Japan from 2009 to 2012 were studied. The retrograde approach was used in 1656 CTO-PCIs (27.7%). We investigated these retrograde procedures to evaluate factors for predicting retrograde CTO-PCI failure even after successful collateral channel crossing. Successful guidewire/catheter collateral crossing was achieved in 77.1% (n = 1,276) of 1656 retrograde CTO-PCI procedures. Retrograde procedural success after successful collateral crossing was achieved in 89.4% (n = 1,141). Univariate analysis showed that the predictors for retrograde CTO-PCI failure were in-stent occlusion (OR = 1.9829, 95%CI = 1.1783 - 3.3370 P = 0.0088), calcified lesions (OR = 1.9233, 95%CI = 1.2463 - 2.9679, P = 0.0027), and lesion tortuosity (OR = 1.5244, 95%CI = 1.0618 - 2.1883, P = 0.0216). On multivariate analysis, lesion calcification was an independent predictor of retrograde CTO-PCI failure after successful collateral channel crossing (OR = 1.3472, 95%CI = 1.0614 - 1.7169, P = 0.0141). The success rate of retrograde CTO-PCI following successful guidewire/catheter collateral channel crossing was high in this registry. Lesion calcification was an independent predictor of retrograde CTO-PCI failure after successful collateral channel crossing. Devices and techniques to overcome complex CTO lesion morphology, such as lesion calcification, are required to further improve the retrograde CTO-PCI success rate. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Effects of Intrarenal and Intravenous Infusion of the Phosphodiesterase 3 Inhibitor Milrinone on Renin Secretion

NASA Technical Reports Server (NTRS)

Kumagai, Kazuhiro; Reid, Ian A.

1994-01-01

We have reported that administration of the phosphodiesterase III inhibitor milrinone increases renin secretion in conscious rabbits. The aim of the present study was to determine if the increase in renin secretion results from a direct renal action of milrinone, or from an indirect extrarenal effect of the drug. This was accomplished by comparing the effects of intrarenal and intravenous infusion of graded doses of milrinone on plasma renin activity in unilaterally nephrectomized conscious rabbits. Milrinone was infused into the renal artery in doses of 0.01, 0.1 and 1.0 micro-g/kg/min, and intravenously in the same rabbits in doses of 0.01, 0.1, 1.0 and 10 micro-g/kg/min. Each dose was infused for 15 min. No intrarenal dose of milrinone altered plasma renin activity or arterial pressure, although at the highest dose, there was a small increase in heart rate. Intravenous infusion of milrinone at 1.0 micro-g/kg/min increased plasma renin activity to 176 +/- 55% of the control value (P less than 0.05). Heart rate increased but arterial pressure did not change. Intravenous infusion of milrinone at 1O micro-g/kg/min increased plasma renin activity to 386 +/- 193% of control in association with a decrease in arterial pressure and an increase in heart rate. These results confirm that milrinone increases renin secretion, and indicate that the stimulation is due to an extrarenal effect of the drug.

The loss of episodic memories in retrograde amnesia: single-case and group studies.

PubMed

Kopelman, M D; Kapur, N

2001-09-29

Retrograde amnesia in neurological disorders is a perplexing and fascinating research topic. The severity of retrograde amnesia is not well correlated with that of anterograde amnesia, and there can be disproportionate impairments of either. Within retrograde amnesia, there are various dissociations which have been claimed-for example, between the more autobiographical (episodic) and more semantic components of memory. However, the associations of different types of retrograde amnesia are also important, and clarification of these issues is confounded by the fact that retrograde amnesia seems to be particularly vulnerable to psychogenic factors. Large frontal and temporal lobe lesions have been postulated as critical in producing retrograde amnesia. Theories of retrograde amnesia have encompassed storage versus access disruption, physiological processes of 'consolidation', the progressive transformation of episodic memories into a more 'semantic' form, and multiple-trace theory. Single-case investigations, group studies and various forms of neuroimaging can all contribute to the resolution of these controversies.

A retrograde co-orbital asteroid of Jupiter.

PubMed

Wiegert, Paul; Connors, Martin; Veillet, Christian

2017-03-29

Recent theoretical work in celestial mechanics has revealed that an asteroid may orbit stably in the same region as a planet, despite revolving around the Sun in the sense opposite to that of the planet itself. Asteroid 2015 BZ 509 was discovered in 2015, but with too much uncertainty in its measured orbit to establish whether it was such a retrograde co-orbital body. Here we report observations and analysis that demonstrates that asteroid 2015 BZ 509 is indeed a retrograde co-orbital asteroid of the planet Jupiter. We find that 2015 BZ 509 has long-term stability, having been in its current, resonant state for around a million years. This is long enough to preclude precise calculation of the time or mechanism of its injection to its present state, but it may be a Halley-family comet that entered the resonance through an interaction with Saturn. Retrograde co-orbital asteroids of Jupiter and other planets may be more common than previously expected.

Retrograde Coronary Chronic Total Occlusion Intervention

PubMed Central

Dash, Debabrata

2015-01-01

Coronary chronic total occlusion (CTO) is a frequent finding in patients with coronary artery disease. It remains one of the most challenging subsets, accounting for 10-20% of all percutaneous coronary interventions (PCI). Although remarkable progress in PCI has been made, it is reasonable to state that successful recanalization of CTO represents the “last frontier” of PCI. PCI of CTOs has been limited historically by technical success rates of 50-70%. The introduction of enhanced guidewires, microcatheter, channel dilatator with increasing operator experience, and innovative techniques such as the retrograde approach have raised hopes for better outcomes. This article goes into depth into various strategies of retrograde approach in CTO.

Chinese Minimally Invasive Percutaneous Nephrolithotomy for Intrarenal Stones in Patients with Solitary Kidney: A Single-Center Experience

PubMed Central

Huang, Zhichao; Fu, Fajun; Zhong, Zhaohui; Zhang, Lei; Xu, Ran; Zhao, Xiaokun

2012-01-01

Objective To report our experience with Chinese minimally invasive percutaneous nephrolithotomy (Chinese MPCNL) to manage patients with intrarenal stones in solitary kidney, and evaluate the safety, efficiency and feasibility of this technique. Methods Forty-one patients with intrarenal stones in solitary kidney underwent Chinese MPCNL in our department from March 2009 to February 2011. Demographic characteristics, operative parameters, number of tracts, stone-free rates (SFRs), stone analyses, hemoglobin levels, nephrostomy tube removal time, hospitalization time, and complications were evaluated. Serum creatinine (Scr) and glomerular filtration rate (GFR) were measured preoperatively, postoperatively at 1 month, and each follow-up visit. The 5-stage classification of chronic kidney disease (CKD) was used according to the National Kidney Foundation guidelines. Results The initial stone-free status was achieved in 35 (85.4%) patients after Chinese MPCNL. The mean follow-up time was 16.9±4.7 months (range: 12–24), and the final SFR improved to 97.6% after auxiliary procedures. Among all patients, complex stones were detected in 26 (63.4%) patients, and 9 (22.0%) required multiple tracts. The mean operative time and mean hospitalization time were 71.3±23.5 min (range: 40–139) and 6.1±0.5 days (range: 5–11), respectively. During preoperative period and postoperative period (1 month), Scr were 132.1±41.3 umol/L (range: 78.2–231.4) and 108.9±30.7 umol/L (range: 71.6–136.9), respectively (P<0.05), while GFR were 74.9±24.2 ml/min (range: 35–110) and 83.9±27.4 ml/min (range: 65–110), respectively (P<0.05). According to CKD classification, the renal function was stable, improved, and worse in 29 (70.7%), 11 (26.8%), and 1 (2.5%) patients, compared with the preoperative levels. No patient progressed to end-stage renal disease requiring dialysis. Conclusions Our experience with Chinese MPCNL demonstrates that it is safe, feasible and efficient for

Retrograde resonance in the planar three-body problem

NASA Astrophysics Data System (ADS)

Morais, M. H. M.; Namouni, F.

2013-12-01

We continue the investigation of the dynamics of retrograde resonances initiated in Morais and Giuppone (Mon Notices R Astron Soc 424:52-64, doi:10.1111/j.1365-2966.2012.21151.x, 2012). After deriving a procedure to deduce the retrograde resonance terms from the standard expansion of the three-dimensional disturbing function, we concentrate on the planar problem and construct surfaces of section that explore phase-space in the vicinity of the main retrograde resonances (2/1, 1/1 and 1/2). In the case of the 1/1 resonance for which the standard expansion is not adequate to describe the dynamics, we develop a semi-analytic model based on numerical averaging of the unexpanded disturbing function, and show that the predicted libration modes are in agreement with the behavior seen in the surfaces of section.

Focal retrograde amnesia and the episodic-semantic distinction.

PubMed

Wheeler, M A; McMillan, C T

2001-03-01

This article reports a review of focal retrograde amnesia (FRA), or the phenomenon of organically based severe memory loss restricted to retrograde, or pretraumatic, memory. Cases of FRA are classified according to the type of memory loss: episodic, semantic, or both. A few different clusters of the disorder were identified. Lesions to either the anterior temporal lobes or the posterior/visual cortex can result in an FRA that devastates retrograde episodic memory, while having smaller effects on semantic memory. A number of left-hemisphere patients have FRA confined to semantic memory. There are several additional examples of FRA following minor cerebral trauma that disrupts either episodic memory alone or both episodic and semantic memory that are not accompanied by evidence of structural brain lesions. We discuss these different profiles of FRA and their implications for the understanding of memory retrieval.

Phenotypic subgroups of polycystic ovary syndrome have different intra-renal resistance symptoms.

PubMed

Ciftci, Ceylan F; Uckuyu, Ayla; Karadeli, Elif; Turhan, Erdem; Toprak, Erzat; Ozcimen, Emel E

2012-12-01

The polycystic ovary syndrome (PCOS) is known to be related with increased metabolic and cardiovascular risks. Various phenotypic subgroups of PCOS have been proven to have metabolic and endocrine disorders with varying degrees of severity However, intra-renal vascular resistance, which is an indirect indication of atherosclerosis, remains unknown in PCOS subgroups. In this study we examined whether PCOS subgroups have different intra-renal resistance symptoms. 98 PCOS patients (diagnosed according to the Rotterdam criteria) 30 controls were included in the study The diagnosis of PCOS was established in the presence of at least two of the following criteria: 1-oligo and/or amenorrhea (OM); 2-clinic and/or biochemical signs of hyperandrogenism (HA); 3-polycystic ovarian morphology (PCO) detected by transvaginal ultrasonography 37 patients (Group 1) met all three criteria (HA+OM+PCO), 29 patients (Group 2) met two of the criteria including hyperandrogenism (HA+OM or HA+PCO) and the remaining 32 patients (Group 3) had no hyperandrogenism but fulfilled the other two criteria; PCO+OM. Renal Doppler ultrasonography and hormonal/biochemical analyses were carried out. The first outcome measure was designated as the differences in the renal resistive index (RRI) values of the groups, and the second outcome measure was designated as the relation of RRI with the insulin resistance and lipid profile. In Group 1, the RRI and the homeostasis model assessment of insulin resistance (HOMA-IR) values were significantly higher than in Group 3 and controls (P < 0.031, P < 0.001, respectively after adjusting for age and BMI). The RRI and HOMA-IR values in Group 3 were similar to those of the control group. It was determined that RRI has a positive correlation with HOMA-IR (r = 0.784, P < .0001) and BMI (r = 0.645, P < .0001). In this study we demonstrated that PCOS subgroups have metabolic and endocrine disorders and cardiovascular risks of varying degrees of severity Moreover, we

Passive-bending, short-type single-balloon enteroscope for endoscopic retrograde cholangiopancreatography in Roux-en-Y anastomosis patients.

PubMed

Yamauchi, Hiroshi; Kida, Mitsuhiro; Okuwaki, Kosuke; Miyazawa, Shiro; Iwai, Tomohisa; Tokunaga, Shuko; Takezawa, Miyoko; Imaizumi, Hiroshi; Koizumi, Wasaburo

2015-02-07

To evaluate short-type-single-balloon enteroscope (SBE) with passive-bending, high-force transmission functions for endoscopic retrograde cholangiopancreatography (ERCP) in patients with Roux-en-Y anastomosis. Short-type SBE with this technology (SIF-Y0004-V01; working length, 1520 mm; channel diameter, 3.2 mm) was used to perform 50 ERCP procedures in 37 patients with Roux-en-Y anastomosis. The rate of reaching the blind end, time required to reach the blind end, diagnostic and therapeutic success rates, and procedure time and complications were studied retrospectively and compared with the results of 34 sessions of ERCP performed using a short-type SBE without this technology (SIF-Y0004; working length, 1520 mm; channel diameter, 3.2 mm) in 25 patients. The rate of reaching the blind end was 90% with SIF-Y0004-V01 and 91% with SIF-Y0004 (P = 0.59). The median time required to reach the papilla was significantly shorter with SIF-Y0004-V01 than with SIF-Y0004 (16 min vs 24 min, P = 0.04). The diagnostic success rate was 93% with SIF-Y0004-V01 and 84% with SIF-Y0004 (P = 0.17). The therapeutic success rate was 95% with SIF-Y0004-V01 and 96% with SIF-Y0004 (P = 0.68). The median procedure time was 40 min with SIF-Y0004-V01 and 36 min with SIF-Y0004 (P = 0.50). The incidence of hyperamylasemia was 6.0% in the SIF-Y0004-V01 group and 14.7% in the SIF-Y0004 group (P = 0.723). The incidence of pancreatitis was 0% in the SIF-Y0004-V01 group and 5.9% in the SIF-Y0004 group (P > 0.999). The incidence of gastrointestinal perforation was 2.0% (1/50) in the SIF-Y0004-V01 group and 2.9% (1/34) in the SIF-Y0004 group (P > 0.999). SIF-Y0004-V01 is useful for ERCP in patients with Roux-en-Y anastomosis and may reduce the time required to reach the blind end.

Intrarenal Mas and AT1 receptors play a role in mediating the excretory actions of renal interstitial angiotensin-(1-7) infusion in anaesthetized rats.

PubMed

O'Neill, Julie; Healy, Vincent; Johns, Edward J

2017-12-01

What is the central question of this study? Dietary sodium manipulation alters the magnitude of angiotensin-(1-7) [Ang-(1-7)]-induced natriuresis. The present study sought to determine whether this was related to relative changes in the activity of intrarenal Mas and/or AT 1 receptors. What is the main finding and its importance? Angiotensin-(1-7)-induced diuresis and natriuresis is mediated by intrarenal Mas receptors. However, intrarenal AT 1 receptor blockade also had an inhibitory effect on Ang-(1-7)-induced natriuresis and diuresis. Thus, Ang-(1-7)-induced increases in sodium and water excretion are dependent upon functional Mas and AT 1 receptors. We investigated whether angiotensin-(1-7) [Ang-(1-7)]-induced renal haemodynamic and excretory actions were solely dependent upon intrarenal Mas receptor activation or required functional angiotensin II type 1 (AT 1 ) receptors. The renin-angiotensin system was enhanced in anaesthetized rats by prior manipulation of dietary sodium intake. Angiotensin-(1-7) and AT 1 and Mas receptor antagonists were infused into the kidney at the corticomedullary border. Mas receptor expression was measured in the kidney. Mean arterial pressure, urine flow and fractional sodium excretion were 93 ± 4 mmHg, 46.1 ± 15.7 μl min -1  kg -1 and 1.4 ± 0.3%, respectively, in the normal-sodium group and 91 ± 2 mmHg, 19.1 ± 3.3 μl min -1  kg -1 and 0.7 ± 0.2%, respectively, in the low-sodium group. Angiotensin-(1-7) infusion had no effect on mean arterial pressure in rats receiving a normal-sodium diet but decreased it by 4 ± 5% in rats receiving a low-sodium diet (P < 0.05). Interstitial Ang-(1-7) infusion increased urine flow twofold and fractional sodium excretion threefold (P < 0.05) in rats receiving a normal-sodium diet and to a greater extent, approximately three- and fourfold, respectively, in rats receiving the low-sodium diet (both P < 0.05). Angiotensin-(1-7)-induced increases in urine flow and

Using Kinesthetic Activities to Teach Ptolemaic and Copernican Retrograde Motion

NASA Astrophysics Data System (ADS)

Richards, Ted

2012-06-01

This paper describes a method for teaching planetary retrograde motion, and the Ptolemaic and Copernican accounts of retrograde motion, by means of a series kinesthetic learning activities (KLAs). In the KLAs described, the students literally walk through the motions of the planets in both systems. A retrospective statistical analysis shows that students who participated in these activities performed better on examination questions pertaining to retrograde motion than students who did not. Potential explanations for this result, including the breaking of classroom routine, the effect of body movement on conceptual memory, and egocentric spatial proprioception, are considered.

Long-term retrograde amnesia...the crucial role of the hippocampus.

PubMed

Cipolotti, L; Shallice, T; Chan, D; Fox, N; Scahill, R; Harrison, G; Stevens, J; Rudge, P

2001-01-01

For patients with hippocampal pathology, disagreement exists in the literature over whether retrograde amnesia is temporally limited or very extensive depending on whether the anatomical damage is restricted to this structure or also involves additional temporal cortex. We report a comprehensive assessment of retrograde and anterograde memory functions of a severely global amnesic patient (VC). We found that he presented with a remarkably extensive and basically ungraded retrograde amnesia. This impairment profoundly affected four decades preceding the onset of his amnesia and encompassed both non personal and personal facts and events. VC also presented with a severe anterograde amnesia and a deficit in the acquisition of new semantic knowledge in the post-morbid period. Detailed MRI volumetric measurements revealed gross abnormalities in both hippocampi which were markedly shrunken. Of relevance to the debate on retrograde amnesia were the observations that the volumes of both entorhinal cortices and the remainder of both temporal lobes were normal. These data suggest that the hippocampus is critical not only for the efficient encoding and hence normal recall of new information but also for the recall of episodic information acquired before the onset of amnesia. Our results are compatible with the view that retrograde amnesia is both extensive and ungraded when the damage is limited to the hippocampus.

Directed Retrograde Cerebral Protection during Moderate Hypothermic Circulatory Arrest

PubMed Central

Yacoubian, Vahe; Jyrala, Aarne; Kay, Gregory L.

2006-01-01

There are many choices for neurologic protection for aortic arch surgery. Although numerous investigators have challenged the efficacy of retrograde cerebral perfusion, we have had good results with our application of this technique. We performed a retrospective review of 8 consecutive patients who underwent surgery from 1 June 2001 through 31 March 2003; the age range was 33 to 97 years. All patients required circulatory arrest and underwent retrograde cerebral perfusion with use of a tourniquet on the patients' left and right arms above the elbow to direct retrograde flow to the brain. Moderate hypothermia (around 24 °C nasopharyngeal) was used; circulatory arrest time ranged from 27 to 63 minutes. There was 1 late hospital death due to multiple-organ system failure. There were no neurologic complications (stroke or temporary neurologic dysfunction). There was no substantive neurologic or renal dysfunction in this cohort, in which moderate hypothermia was used. These results are comparable to those reported in the literature for similar patients. We conclude that, for patients who require circulatory arrest, directed retrograde cerebral perfusion at moderate nasopharyngeal hypothermia gives results comparable to those reported with other techniques. PMID:17215968

Phytochrome and retrograde signalling pathways coverage to antogonistically regulate a light-induced transcription network

USDA-ARS?s Scientific Manuscript database

Plastid-to-nucleus retrograde signals emitted by dysfunctional chloroplasts impact photomorphogenic development, but the molecular link between retrograde and photosensory-receptor signaling has remained undefined. Here, we show that the phytochrome (phy) and retrograde signaling pathways converge a...

Using Kinesthetic Activities to Teach Ptolemaic and Copernican Retrograde Motion

ERIC Educational Resources Information Center

Richards, Ted

2012-01-01

This paper describes a method for teaching planetary retrograde motion, and the Ptolemaic and Copernican accounts of retrograde motion, by means of a series kinesthetic learning activities (KLAs). In the KLAs described, the students literally walk through the motions of the planets in both systems. A retrospective statistical analysis shows that…

Changing strategies of the retrograde approach for chronic total occlusion during the past 7 years.

PubMed

Muramatsu, Toshiya; Tsukahara, Reiko; Ito, Yoshiaki; Ishimori, Hiroshi; Park, Seung-Jung; de Winter, Robert; Shokry, Khaled; Wang, Lefeng; Chen, Jiyan; Wang, Haichang

2013-03-01

We reviewed the technical changes and results achieved with the retrograde approach since we introduced it 7 years ago. The subjects were 1,268 patients who were treated for CTO between January 2004 and December 2010. They were investigated with respect to the success rate, the frequency of employing the retrograde approach and its outcome, and other factors. The retrograde approach was employed in ∼30% of chronic total occlusion (CTO) patients (n = 281) and the retrograde guidewire success rate was 81.1%. The kissing wire technique was substituted for the retrograde approach in 126 of the 281 patients, with antegrade crossing of a guidewire being successful in 88 of them (70%). The retrograde approach was combined with the CART and reverse controlled antegrade retrograde tracking (CART) techniques in 22 and 21 patients, respectively. Among 83 patients treated with Corsair catheters, crossing of the CTO was achieved in 63. The overall procedural success rate was 79.7% (224 patients). Complications of the retrograde approach included collateral channel dissection (2.1%), channel perforation (1.7%), CTO perforation (1.7%), and donor artery occlusion (1.1%). The success rate and safety of the retrograde approach are both satisfactory if the appropriate devices and techniques are selected. Copyright © 2012 Wiley Periodicals, Inc.

Simultaneous Antegrade-Retrograde Subintimal Revascularization of a Femoropopliteal Chronic Total Occlusion by a Reentry Device-Facilitated Puncture of a Retrogradely Inserted Balloon.

PubMed

Goltz, Jan Peter; Anton, Susanne; Wiedner, Marcus; Barkhausen, Jörg; Stahlberg, Erik

2017-08-01

To report a rendezvous technique for subintimal revascularization of a chronic total occlusion (CTO) of the superficial femoral artery (SFA). This maneuver is appropriate after failure to cross a long SFA CTO via intra- and subintimal approaches from the ipsilateral femoral as well as retrograde posterior tibial artery (PTA) access sites. After predilation of the subintimal space from the femoral access, a reentry device was placed at the level of the first popliteal artery segment. A balloon was delivered via the retrograde PTA access and inflated at the corresponding level of the reentry device. The balloon was punctured with the needle of the reentry device under fluoroscopic control, and a 0.014-inch guidewire was placed within the punctured balloon. The balloon and the antegrade guidewire were retracted from the retrograde access while the guidewire was gently pushed from the femoral site. Conventional balloon angioplasty of the SFA occlusion was performed via the femoral access, followed by overlapping stent-graft implantation. Complete revascularization of the CTO was documented. In selected cases a transfemoral reentry device-assisted puncture of a retrogradely inserted balloon within the subintimal space may facilitate a rendezvous and revascularization if standard techniques to cross long CTOs have failed.

Factors Influencing Cecal Intubation Time during Retrograde Approach Single-Balloon Enteroscopy

PubMed Central

Chen, Peng-Jen; Shih, Yu-Lueng; Huang, Hsin-Hung; Hsieh, Tsai-Yuan

2014-01-01

Background and Aim. The predisposing factors for prolonged cecal intubation time (CIT) during colonoscopy have been well identified. However, the factors influencing CIT during retrograde SBE have not been addressed. The aim of this study was to determine the factors influencing CIT during retrograde SBE. Methods. We investigated patients who underwent retrograde SBE at a medical center from January 2011 to March 2014. The medical charts and SBE reports were reviewed. The patients' characteristics and procedure-associated data were recorded. These data were analyzed with univariate analysis as well as multivariate logistic regression analysis to identify the possible predisposing factors. Results. We enrolled 66 patients into this study. The median CIT was 17.4 minutes. With univariate analysis, there was no statistical difference in age, sex, BMI, or history of abdominal surgery, except for bowel preparation (P = 0.021). Multivariate logistic regression analysis showed that inadequate bowel preparation (odds ratio 30.2, 95% confidence interval 4.63–196.54; P < 0.001) was the independent predisposing factors for prolonged CIT during retrograde SBE. Conclusions. For experienced endoscopist, inadequate bowel preparation was the independent predisposing factor for prolonged CIT during retrograde SBE. PMID:25505904

Experimental comparison of manually inflatable versus autoinflatable retrograde cardioplegia catheters.

PubMed

Menasché, P

1994-08-01

A pig model of cardiopulmonary bypass and cardioplegic arrest was used to compare leakage around manually inflatable and autoinflatable retrograde coronary sinus cardioplegia catheters. Warm and cold blood cardioplegia were alternately delivered through the catheter under study at both low (16 to 24 mm Hg) and high (30 to 40 mm Hg) perfusion pressures. During each experiment, the coronary sinus ostium was sealed around the shaft of the retrograde cannula so that all backflow occurring during cardioplegia delivery could be collected by a separate drainage catheter inserted directly into the coronary sinus approximately midway between the right atrium and the distal end of the balloon. Only two of the 52 manually inflatable cannulas leaked. The leakage in both cases was negligible (< 1% of the total retrograde cardioplegia flow). In contrast, leakage occurred with 57 of the 73 autoinflatable devices tested (p < 0.0001) and averaged 22% +/- 3% (mean +/- the standard error of the mean) of the total retrograde flow. The temperature of the cardioplegia solution had no effect on leakage. These results suggest that autoinflatable balloons inconsistently seal the coronary sinus during cardioplegia infusion, thereby decreasing the amount of flow that effectively reaches the myocardium. This should make surgeons cautious about using them with warm blood cardioplegia, which largely relies upon the delivery of sufficiently high retrograde nutritive flows for preventing cardioprotective aerobic arrest from becoming a life-threatening ischemic arrest.

The impact of intrarenal nitric oxide synthase inhibition on renal blood flow and function in mild and severe hyperdynamic sepsis.

PubMed

Ishikawa, Ken; Bellomo, Rinaldo; May, Clive N

2011-04-01

In experimental hyperdynamic sepsis, renal function deteriorates despite renal vasodilatation and increased renal blood flow. Because nitric oxide is increased in sepsis and participates in renal blood flow control, we investigated the effects of intrarenal Nω-nitro-L-arginine methyl ester, a nonspecific nitric oxide synthase inhibitor, in mild and severe sepsis. Prospective crossover and randomized control interventional studies. University-affiliated research institute. Thirty-two merino ewes. Examination of responses to intrarenal infusion of Nω-nitro-L-arginine methyl ester for 8 hrs in unilaterally nephrectomized normal sheep and in sheep administered Escherichia coli. : In normal sheep, Nω-nitro-L-arginine methyl ester decreased renal blood flow (301 ± 30 to 228 ± 26 mL/min) and creatinine clearance (40.0 ± 5.8 to 31.1 ± 2.8 mL/min), whereas plasma creatinine increased, but fractional excretion of sodium was unchanged. In sheep with nonhypotensive hyperdynamic sepsis, plasma creatinine increased and there were decreases in creatinine clearance (34.5 ± 4.6 to 20.1 ± 3.7 mL/min) and fractional excretion of sodium despite increased renal blood flow. Infusion of Nω-nitro-L-arginine methyl ester normalized renal blood flow and increased urine output, but creatinine clearance did not improve and plasma creatinine and fractional excretion of sodium increased. In sheep with severe hypotensive sepsis, creatinine clearance decreased further (31.1 ± 5.4 to 16.0 ± 1.7 mL/min) despite increased renal blood flow. Infusion of Nω-nitro-L-arginine methyl ester restored mean arterial pressure and reduced renal blood flow but did not improve plasma creatinine or creatinine clearance. In hyperdynamic sepsis, with or without hypotension, creatinine clearance decreased despite increasing renal blood flow. Intrarenal Nω-nitro-L-arginine methyl ester infusion reduced renal blood flow but did not improve creatinine clearance. These data indicate that septic acute kidney

Effects of inulin with different degree of polymerization on gelatinization and retrogradation of wheat starch.

PubMed

Luo, Denglin; Li, Yun; Xu, Baocheng; Ren, Guangyue; Li, Peiyan; Li, Xuan; Han, Sihai; Liu, Jianxue

2017-08-15

The effects of three types of inulin, including FS (DP≤10), FI (DP of 2-60) and FXL (DP≥23), on the gelatinization and retrogradation characteristics of wheat starch were investigated. As the concentration of inulin added into starch increased, the gelatinization temperature increased whereas the breakdown value decreased, and the value of setback first decreased and then increased slightly. The three types of inulin with lower concentrations (<15%) all showed obvious suppression effects on the short-term retrogradation of wheat starch. After 7days of storage, the three types of inulin showed a significant suppression of starch retrogradation in the addition range of 5-7.5%. They can all inhibit amylose retrogradation, but accelerate amylopectin retrogradation. Inulin with lower DP has stronger effects on the starch retrogradation. Generally, the three types of inulin can all retard the retrogradation performance of wheat starch to some extent in the long-term storage. Copyright © 2017 Elsevier Ltd. All rights reserved.

Process for forming retrograde profiles in silicon

DOEpatents

Weiner, K.H.; Sigmon, T.W.

1996-10-15

A process is disclosed for forming retrograde and oscillatory profiles in crystalline and polycrystalline silicon. The process consisting of introducing an n- or p-type dopant into the silicon, or using prior doped silicon, then exposing the silicon to multiple pulses of a high-intensity laser or other appropriate energy source that melts the silicon for short time duration. Depending on the number of laser pulses directed at the silicon, retrograde profiles with peak/surface dopant concentrations which vary are produced. The laser treatment can be performed in air or in vacuum, with the silicon at room temperature or heated to a selected temperature.

Functional retrograde amnesia: a quantitative case study.

PubMed

Schacter, D L; Wang, P L; Tulving, E; Freedman, M

1982-01-01

The memory impairment of a patient suffering from functional retrograde amnesia was assessed both during the amnesic episode and after its termination. The patient's performance on a task tapping semantic memory was nearly identical on the two test occasions, but his performance on a task tapping episodic memory substantially changed across test sessions. Cueing procedures revealed that in spite of the patient's restricted access to episodic memory during the amnesic period, a relatively intact "island" of episodic memories could be uncovered. The distinction between episodic and semantic memory, as well as the relation between organic and functional retrograde amnesia, are discussed in light of the case study.

Changing Strategies of the Retrograde Approach for Chronic Total Occlusion During the Past 7 Years

PubMed Central

Muramatsu, Toshiya; Tsukahara, Reiko; Ito, Yoshiaki; Ishimori, Hiroshi; Park, Seung-Jung; Winter, Robert; Shokry, Khaled; Wang, Lefeng; Chen, Jiyan; Wang, Haichang

2013-01-01

Objective We reviewed the technical changes and results achieved with the retrograde approach since we introduced it 7 years ago. Subjects and Methods The subjects were 1,268 patients who were treated for CTO between January 2004 and December 2010. They were investigated with respect to the success rate, the frequency of employing the retrograde approach and its outcome, and other factors. Results The retrograde approach was employed in ∼30% of chronic total occlusion (CTO) patients (n = 281) and the retrograde guidewire success rate was 81.1%. The kissing wire technique was substituted for the retrograde approach in 126 of the 281 patients, with antegrade crossing of a guidewire being successful in 88 of them (70%). The retrograde approach was combined with the CART and reverse controlled antegrade retrograde tracking (CART) techniques in 22 and 21 patients, respectively. Among 83 patients treated with Corsair catheters, crossing of the CTO was achieved in 63. The overall procedural success rate was 79.7% (224 patients). Complications of the retrograde approach included collateral channel dissection (2.1%), channel perforation (1.7%), CTO perforation (1.7%), and donor artery occlusion (1.1%). Conclusion The success rate and safety of the retrograde approach are both satisfactory if the appropriate devices and techniques are selected. © 2012 Wiley Periodicals, Inc. PMID:22517670

Optimal Timing for Laparoscopic Cholecystectomy After Endoscopic Retrograde Cholangiopancreatography: A Systematic Review.

PubMed

Friis, C; Rothman, J P; Burcharth, J; Rosenberg, J

2018-06-01

Endoscopic retrograde cholangiopancreatography followed by laparoscopic cholecystectomy is often used as definitive treatment for common bile duct stones. The aim of this study was to investigate the optimal time interval between endoscopic retrograde cholangiopancreatography and laparoscopic cholecystectomy. PubMed and Embase were searched for studies comparing different time delays between endoscopic retrograde cholangiopancreatography and laparoscopic cholecystectomy. Observational studies and randomized controlled trials were included. Primary outcome was conversion rate from laparoscopic to open cholecystectomy and secondary outcomes were complications, mortality, operating time, and length of stay. A total of 14 studies with a total of 1930 patients were included. The pooled estimate revealed an increase from a 4.2% conversion rate when laparoscopic cholecystectomy was performed within 24 h of endoscopic retrograde cholangiopancreatography to 7.6% for 24-72 h delay to 12.3% when performed within 2 weeks, to 12.3% for 2-6 weeks, and to a 14% conversion rate when operation was delayed more than 6 weeks. According to this systematic review, it is preferable to perform cholecystectomy within 24 h of endoscopic retrograde cholangiopancreatography to reduce conversion rate. Early laparoscopic cholecystectomy does not increase mortality, perioperative complications, or length of stay and on the contrary it reduces the risk of reoccurrence and progression of disease in the delay between endoscopic retrograde cholangiopancreatography and laparoscopic cholecystectomy.

A novel fluorescent retrograde neural tracer: cholera toxin B conjugated carbon dots

NASA Astrophysics Data System (ADS)

Zhou, Nan; Hao, Zeyu; Zhao, Xiaohuan; Maharjan, Suraj; Zhu, Shoujun; Song, Yubin; Yang, Bai; Lu, Laijin

2015-09-01

The retrograde neuroanatomical tracing method is a key technique to study the complex interconnections of the nervous system. Traditional tracers have several drawbacks, including time-consuming immunohistochemical or immunofluorescent staining procedures, rapid fluorescence quenching and low fluorescence intensity. Carbon dots (CDs) have been widely used as a fluorescent bio-probe due to their ultrasmall size, excellent optical properties, chemical stability, biocompatibility and low toxicity. Herein, we develop a novel fluorescent neural tracer: cholera toxin B-carbon dot conjugates (CTB-CDs). It can be taken up and retrogradely transported by neurons in the peripheral nervous system of rats. Our results show that CTB-CDs possess high photoluminescence intensity, good optical stability, a long shelf-life and non-toxicity. Tracing with CTB-CDs is a direct and more economical way of performing retrograde labelling experiments. Therefore, CTB-CDs are reliable fluorescent retrograde tracers.The retrograde neuroanatomical tracing method is a key technique to study the complex interconnections of the nervous system. Traditional tracers have several drawbacks, including time-consuming immunohistochemical or immunofluorescent staining procedures, rapid fluorescence quenching and low fluorescence intensity. Carbon dots (CDs) have been widely used as a fluorescent bio-probe due to their ultrasmall size, excellent optical properties, chemical stability, biocompatibility and low toxicity. Herein, we develop a novel fluorescent neural tracer: cholera toxin B-carbon dot conjugates (CTB-CDs). It can be taken up and retrogradely transported by neurons in the peripheral nervous system of rats. Our results show that CTB-CDs possess high photoluminescence intensity, good optical stability, a long shelf-life and non-toxicity. Tracing with CTB-CDs is a direct and more economical way of performing retrograde labelling experiments. Therefore, CTB-CDs are reliable fluorescent retrograde

Management of lower pole renal stones: the devil is in the details.

PubMed

Resorlu, Berkan; Issi, Yasar; Onem, Kadir; Germiyanoglu, Cankon

2016-03-01

Shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (MIP) are highly effective treatment options for lower pole stones up to 2 cm. Selecting the best treatment modality represents a controversial area in urology, because each treatment methods have their own advantages and disadvantages. Donaldson and co-workers have recently published a very comprehensive review and meta-analysis to compare the benefits and harms of SWL, RIRS and PNL techniques.

Effects of low molecular sugars on the retrogradation of tapioca starch gels during storage

PubMed Central

Li, Rongfang; Kang, Huaibin; Luo, Denglin; Fan, Jinling; Zhu, Wenxue; Liu, Xinfang; Tong, Qunyi

2017-01-01

The effects of low molecular sugars (sucrose, glucose and trehalose) on the retrogradation of tapioca starch (TS) gels stored at 4°C for different periods were examined with different methods. Decrease in melting enthalpy (ΔHmelt) were obtained through differential scanning calorimetry analysis. Analysis of decrease in crystallization rate constant (k) and increase in semi-crystallization time (τ1/2) results obtained from retrogradation kinetics indicated that low molecular sugars could retard the retrogradation of TS gels and further revealed trehalose as the best inhibitor among the sugars used in this study. Fourier transform infrared (FTIR) analysis indicated that the intensity ratio of 1047 to 1022 cm−1 was increased with the addition of sugars in the order of trehalose > sucrose > glucose. Decrease in hardness parameters and increase in springiness parameters obtained from texture profile analysis (TPA) analysis also indicated that low molecular sugars could retard the retrogradation of TS gels. The results of FTIR and TPA showed a consistent sugar effect on starch retrogradation with those of DSC and retrogradation kinetics analysis. PMID:29284007

Effects of low molecular sugars on the retrogradation of tapioca starch gels during storage.

PubMed

Zhang, Xiaoyu; Li, Rongfang; Kang, Huaibin; Luo, Denglin; Fan, Jinling; Zhu, Wenxue; Liu, Xinfang; Tong, Qunyi

2017-01-01

The effects of low molecular sugars (sucrose, glucose and trehalose) on the retrogradation of tapioca starch (TS) gels stored at 4°C for different periods were examined with different methods. Decrease in melting enthalpy (ΔHmelt) were obtained through differential scanning calorimetry analysis. Analysis of decrease in crystallization rate constant (k) and increase in semi-crystallization time (τ1/2) results obtained from retrogradation kinetics indicated that low molecular sugars could retard the retrogradation of TS gels and further revealed trehalose as the best inhibitor among the sugars used in this study. Fourier transform infrared (FTIR) analysis indicated that the intensity ratio of 1047 to 1022 cm-1 was increased with the addition of sugars in the order of trehalose > sucrose > glucose. Decrease in hardness parameters and increase in springiness parameters obtained from texture profile analysis (TPA) analysis also indicated that low molecular sugars could retard the retrogradation of TS gels. The results of FTIR and TPA showed a consistent sugar effect on starch retrogradation with those of DSC and retrogradation kinetics analysis.

Complications of bladder distension during retrograde urethrography.

PubMed

Barsanti, J A; Crowell, W; Losonsky, J; Talkington, F D

1981-05-01

A severe, ulcerative cystitis that resulted in macroscopic hematuria occurred in 8 of 20 healthy dogs undergoing a series of diagnostic tests. Four of the remaining 12 dogs had mild bladder lesions consisting of submucosal edema and hemorrhage. Nine of the 20 dogs developed urinary tract infection after the procedures. These complications seemed associated with the radiographic technique of retrograde urethrography performed when the urinary bladder was distended. To test this hypothesis, retrograde urethrography was performed on 5 additional dogs. With the bladder undistended, no complications occurred. However, distention of these same dogs' bladders for 1 minute or less with sterile lactated Ringer's solution administered through a Foley catheter in the penile urethra resulted in a macroscopic hematuria in all 5 dogs which persisted for 24 hours. A microscopic hematuria continued for 5 days. One dog developed a bacterial urinary tract infection. A severe fibrinopurulent cystitis was present at necropsy of 2 dogs 2 days after distention. The morphologic changes in the bladder gradually diminished over 7 days, but mild submucosal edema and hemorrhage were still present when 2 dogs were necropsied, 7 days after distention. These studies indicated that retrograde urethrography in dogs may be complicated by hemorrhagic cystitis and urinary tract infection if performed with urinary bladder distention.

Water dynamics and retrogradation of ultrahigh pressurized wheat starch.

PubMed

Doona, Christopher J; Feeherry, Florence E; Baik, Moo-Yeol

2006-09-06

The water dynamics and retrogradation kinetics behavior of gelatinized wheat starch by either ultrahigh pressure (UHP) processing or heat are investigated. Wheat starch completely gelatinized in the condition of 90, 000 psi at 25 degrees C for 30 min (pressurized gel) or 100 degrees C for 30 min (heated gel). The physical properties of the wheat starches were characterized in terms of proton relaxation times (T2 times) measured using time-domain nuclear magnetic resonance spectroscopy and evaluated using commercially available continuous distribution modeling software. Different T2 distributions in both micro- and millisecond ranges between pressurized and heated wheat starch gels suggest distinctively different water dynamics between pressurized and heated wheat starch gels. Smaller water self-diffusion coefficients were observed for pressurized wheat starch gels and are indicative of more restricted translational proton mobility than is observed with heated wheat starch gels. The physical characteristics associated with changes taking place during retrogradation were evaluated using melting curves obtained with differential scanning calorimetry. Less retrogradation was observed in pressurized wheat starch, and it may be related to a smaller quantity of freezable water in pressurized wheat starch. Starches comprise a major constituent of many foods proposed for commercial potential using UHP, and the present results furnish insight into the effect of UHP on starch gelatinization and the mechanism of retrogradation during storage.

Coronary perforation with tamponade successfully managed by retrograde and antegrade coil embolization

PubMed Central

Boukhris, Marouane; Tomasello, Salvatore Davide; Azzarelli, Salvatore; Elhadj, Zied Ibn; Marzà, Francesco; Galassi, Alfredo Ruggero

2015-01-01

In recent years, retrograde approach for chronic total occlusions has rapidly evolved, enabling a higher rate of revascularization success. Compared to septal channels, epicardial collaterals tend to be more tortuous, more difficult to negotiate, and more prone to rupture. Coronary perforation is a rare but potentially life-threatening complication of coronary angioplasty, often leading to emergency cardiac surgery. We report a case of a retrograde chronic total occlusion revascularization through epicardial collaterals, complicated by both retrograde and antegrade coronary perforation with tamponade, and successfully managed by coil embolization. PMID:26136637

Retrograde Signaling as a Mechanism of Yeast Adaptation to Unfavorable Factors.

PubMed

Trendeleva, T A; Zvyagilskaya, R A

2018-02-01

Mitochondria perform many essential functions in eukaryotic cells. Being the main producers of ATP and the site of many catabolic and anabolic reactions, they participate in intracellular signaling, proliferation, aging, and formation of reactive oxygen species. Mitochondrial dysfunction is the cause of many diseases and even cell death. The functioning of mitochondria in vivo is impossible without interaction with other cellular compartments. Mitochondrial retrograde signaling is a signaling pathway connecting mitochondria and the nucleus. The major signal transducers in the yeast retrograde response are Rtg1p, Rtg2p, and Rtg3p proteins, as well as four additional negative regulatory factors - Mks1p, Lst8p, and two 14-3-3 proteins (Bmh1/2p). In this review, we analyze current information on the retrograde signaling in yeast that is regarded as a stress or homeostatic response mechanism to changes in various metabolic and biosynthetic activities that occur upon mitochondrial dysfunction. We also discuss relations between retrograde signaling and other signaling pathways in the cell.

Retrograde signals arise from reciprocal crosstalk within plastids.

PubMed

Enami, Kazuhiko; Tanaka, Kan; Hanaoka, Mitsumasa

2012-01-01

In addition to the cell nucleus, plant cells also possess genomic DNA and gene expression machineries within mitochondria and plastids. In higher plants, retrograde transcriptional regulation of several nuclear genes encoding plastid-located proteins has been observed in response to changes in a wide variety of physiological properties in plastids, including organelle gene expression (OGE) and tetrapyrrole metabolism. This regulation is postulated to be accomplished by plastid-to-nucleus signaling, (1,2) although the overall signal transduction pathway(s) are not well characterized. By applying a specific differentiation system in tobacco Bright Yellow-2 (BY-2) cultured cells, (3,4) we recently reported that the regulatory system of nuclear gene expressions modulated by a plastid signal was also observed during differentiation of plastids into amyloplasts. (5) While retrograde signaling from plastids was previously speculated to consist of several independent pathways, we found inhibition of OGE and perturbation in the cellular content of one tetrapyrrole intermediate, heme, seemed to interact to regulate amyloplast differentiation. Our results thus highlight the possibility that several sources of retrograde signaling in plastids could be integrated in an intraorganellar manner.

"Rendezvous in coronary" technique with the retrograde approach for chronic total occlusion.

PubMed

Muramatsu, Toshiya; Tsukahara, Reiko; Ito, Yoshiaki

2010-09-01

Percutaneous coronary intervention (PCI) was performed for a chronic total occlusion (CTO) of the right coronary artery (RCA) in a 77-year-old male patient. A guidewire could not be passed through the vessel using the antegrade approach, so we tried the retrograde approach via a collateral septal channel. A Fielder FC guidewire (Asahi Intecc Co. Ltd., Aichi, Japan) was passed through the septal channel, and a Corsair catheter (Asahi Intecc) was advanced to the distal side of the CTO in the RCA. However, the guidewire could not be advanced from the false lumen to the true lumen using the kissing-wire technique (KWT) or the reverse controlled antegrade retrograde tracking (CART) technique. Therefore, we retracted the Corsair channel dilator for a #4PD and tried to advance the antegrade Conquest Pro guidewire (Asahi Intecc) from a straight subintimal site into the retrograde channel dilator catheter. After several attempts, the antegrade Conquest guidewire successfully entered the retrograde channel dilator catheter. Subsequently, a Cypher stent (Cordis Corp., Miami Lakes, Florida) was successfully placed. The "rendezvous in coronary" technique was useful for this CTO patient, in whom it was difficult to advance a guidewire into the true lumen by the KWT and CART techniques during the retrograde approach.

Hippocampal contributions to recollection in retrograde and anterograde amnesia.

PubMed

Gilboa, Asaf; Winocur, Gordon; Rosenbaum, R Shayna; Poreh, Amir; Gao, Fuqiang; Black, Sandra E; Westmacott, Robyn; Moscovitch, Morris

2006-01-01

Lesions restricted to the hippocampal formation and/or extended hippocampal system (hippocampal formation, fornix, mammillary bodies, and anterior thalamic nuclei) can disrupt conscious recollection in anterograde amnesia, while leaving familiarity-based memory relatively intact. Familiarity may be supported by extra-hippocampal medial temporal lobe (MTL) structures. Within-task dissociations in recognition memory best exemplify this distinction in anterograde amnesia. The authors report for the first time comparable dissociations within recognition memory in retrograde amnesia. An amnesic patient (A.D.) with bilateral fornix and septal nuclei lesions failed to recognize details pertaining to personal past events only when recollection was required, during recognition of episodic details. His intact recognition of generic and semantic details pertaining to the same events was ascribed to intact familiarity processes. Recollective processes in the controls were reflected by asymmetrical Receiver's Operating Characteristic curves, whereas the patient's Receiver's Operating Characteristic was symmetrical, suggesting that his inferior recognition performance on episodic details was reliant on familiarity processes. Anterograde and retrograde memories were equally affected, with no temporal gradient for retrograde memories. By comparison, another amnesic person (K.C.) with extensive MTL damage (involving extra-hippocampal MTL structures in addition to hippocampal and fornix lesions) had very poor recognition and no recollection of either episodic or generic/semantic details. These data suggest that the extended hippocampal system is required to support recollection for both anterograde and retrograde memories, regardless of their age.

Investigation of the Usability of Retrograded Flour in Meatball Production as A Structure Enhancer.

PubMed

Dinçer, Elif Aykin; Büyükkurt, Özlem Kiliç; Candal, Cihadiye; Bilgiç, Büşra Fatma; Erbaş, Mustafa

2018-02-01

This study aimed to research the possibilities of using retrograded flour produced in the laboratory environment in meatballs and the characteristics of these meatballs. In the use of retrograded flour to produce meatballs, it was ensured that the meatball properties, with respect to chemical, physical and sensorial aspects, were comparable to those of meatballs produced with bread (traditional) and rusk flour (commercial). The cooking loss of meatballs produced with using retrograded flour was similar to that of commercial meatballs. Doses of retrograded flour from 5% to 20% led to a significant decrease in cooking loss, from 21.95% to 6.19%, and in the diameter of meatballs, from 18.60% to 12.74%, but to an increase in the thickness of meatballs, from 28.82% to 41.39% compared to the control. The increase of a * and b * values was shown in that the meatballs were browned on cooking with increasing retrograded flour doses because of non-enzymatic reactions. The springiness of the traditional meatballs was significantly higher than that of the other meatballs. This might have been due to the bread crumbs having a naturally springy structure. Moreover, the addition of retrograded flour in the meatballs significantly ( p <0.05) affected the hardness, springiness and cohesiveness of the meatballs with respect to textural properties. Accordingly, it is considered that the use of 10% retrograded flour is ideal to improve the sensorial values of meatballs and the properties of their structure.

Investigation of the Usability of Retrograded Flour in Meatball Production as A Structure Enhancer

PubMed Central

2018-01-01

This study aimed to research the possibilities of using retrograded flour produced in the laboratory environment in meatballs and the characteristics of these meatballs. In the use of retrograded flour to produce meatballs, it was ensured that the meatball properties, with respect to chemical, physical and sensorial aspects, were comparable to those of meatballs produced with bread (traditional) and rusk flour (commercial). The cooking loss of meatballs produced with using retrograded flour was similar to that of commercial meatballs. Doses of retrograded flour from 5% to 20% led to a significant decrease in cooking loss, from 21.95% to 6.19%, and in the diameter of meatballs, from 18.60% to 12.74%, but to an increase in the thickness of meatballs, from 28.82% to 41.39% compared to the control. The increase of a* and b* values was shown in that the meatballs were browned on cooking with increasing retrograded flour doses because of non-enzymatic reactions. The springiness of the traditional meatballs was significantly higher than that of the other meatballs. This might have been due to the bread crumbs having a naturally springy structure. Moreover, the addition of retrograded flour in the meatballs significantly (p<0.05) affected the hardness, springiness and cohesiveness of the meatballs with respect to textural properties. Accordingly, it is considered that the use of 10% retrograded flour is ideal to improve the sensorial values of meatballs and the properties of their structure. PMID:29725226

Control of respiration-driven retrograde flow in the subdiaphragmatic venous return of the Fontan circulation

PubMed Central

Vukicevic, M; Conover, T; Jaeggli, M; Zhou, J; Pennati, G; Hsia, TY; Figliola, RS

2014-01-01

Respiration influences the subdiaphragmatic venous return in the total cavopulmonary connection (TCPC) of the Fontan circulation whereby both the inferior vena cava (IVC) and hepatic vein flows can experience retrograde motion. Controlling retrograde flows could improve patient outcomes. Using a patient-specific model within a Fontan mock circulatory system with respiration, we inserted a valve into the IVC to examine its effects on local hemodynamics while varying retrograde volumes by changing vascular impedances. A bovine valved conduit reduced IVC retrograde flow to within 3% of antegrade flow in all cases. The valve closed only under conditions supporting retrograde flow and its effects on local hemodynamics increased with larger retrograde volume. Liver and TCPC pressures improved only while the valve leaflets were closed while cycle-averaged pressures improved only slightly (italic>1 mm Hg). Increased pulmonary vascular resistance raised mean circulation pressures but the valve functioned and cardiac output improved and stabilized. Power loss across the TCPC improved by 12–15% (pbold>0.05) with a valve. The effectiveness of valve therapy is dependent on patient vascular impedance. PMID:24814833

Post-Golgi anterograde transport requires GARP-dependent endosome-to-TGN retrograde transport.

PubMed

Hirata, Tetsuya; Fujita, Morihisa; Nakamura, Shota; Gotoh, Kazuyoshi; Motooka, Daisuke; Murakami, Yoshiko; Maeda, Yusuke; Kinoshita, Taroh

2015-09-01

The importance of endosome-to-trans-Golgi network (TGN) retrograde transport in the anterograde transport of proteins is unclear. In this study, genome-wide screening of the factors necessary for efficient anterograde protein transport in human haploid cells identified subunits of the Golgi-associated retrograde protein (GARP) complex, a tethering factor involved in endosome-to-TGN transport. Knockout (KO) of each of the four GARP subunits, VPS51-VPS54, in HEK293 cells caused severely defective anterograde transport of both glycosylphosphatidylinositol (GPI)-anchored and transmembrane proteins from the TGN. Overexpression of VAMP4, v-SNARE, in VPS54-KO cells partially restored not only endosome-to-TGN retrograde transport, but also anterograde transport of both GPI-anchored and transmembrane proteins. Further screening for genes whose overexpression normalized the VPS54-KO phenotype identified TMEM87A, encoding an uncharacterized Golgi-resident membrane protein. Overexpression of TMEM87A or its close homologue TMEM87B in VPS54-KO cells partially restored endosome-to-TGN retrograde transport and anterograde transport. Therefore GARP- and VAMP4-dependent endosome-to-TGN retrograde transport is required for recycling of molecules critical for efficient post-Golgi anterograde transport of cell-surface integral membrane proteins. In addition, TMEM87A and TMEM87B are involved in endosome-to-TGN retrograde transport. © 2015 Hirata, Fujita, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Roles of type II myosin and a tropomyosin isoform in retrograde actin flow in budding yeast

PubMed Central

Huckaba, Thomas M.; Lipkin, Thomas; Pon, Liza A.

2006-01-01

Retrograde flow of cortical actin networks and bundles is essential for cell motility and retrograde intracellular movement, and for the formation and maintenance of microvilli, stereocilia, and filopodia. Actin cables, which are F-actin bundles that serve as tracks for anterograde and retrograde cargo movement in budding yeast, undergo retrograde flow that is driven, in part, by actin polymerization and assembly. We find that the actin cable retrograde flow rate is reduced by deletion or delocalization of the type II myosin Myo1p, and by deletion or conditional mutation of the Myo1p motor domain. Deletion of the tropomyosin isoform Tpm2p, but not the Tpm1p isoform, increases the rate of actin cable retrograde flow. Pretreatment of F-actin with Tpm2p, but not Tpm1p, inhibits Myo1p binding to F-actin and Myo1p-dependent F-actin gliding. These data support novel, opposing roles of Myo1p and Tpm2 in regulating retrograde actin flow in budding yeast and an isoform-specific function of Tpm1p in promoting actin cable function in myosin-driven anterograde cargo transport. PMID:17178912

Postencephalitic focal retrograde amnesia after bilateral anterior temporal lobe damage.

PubMed

Tanaka, Y; Miyazawa, Y; Hashimoto, R; Nakano, I; Obayashi, T

1999-07-22

Marked retrograde amnesia with no or almost no anterograde amnesia is rare. Recently, a combination of ventrolateral prefrontal and temporopolar cortical lesions has been suggested as the cause of such isolated or focal retrograde amnesia. It is also assumed that when the right-sided cortical structures are damaged, autobiographical episodic memories are affected. To search for new anatomic substrates for focal retrograde amnesia. We performed extensive neuropsychological tests and obtained detailed neuroimages on a 43-year-old woman who showed a severe, persistent retrograde amnesia but only a limited anterograde amnesia after probable herpes simplex encephalitis. Tests of autobiographical memory revealed that she had a memory loss extending back to her childhood for both semantics and incidents; however, the ability to recall specific episodes appeared much more severely impaired than the ability to recall factual information about her past. The patient also showed profound impairments in recalling public memories; however, her scores improved nearly to a control level on forced-choice recognition memory tasks, although the recall of memories for a decade just before her illness remained mildly impaired. MRI revealed focal pathologies in the temporal poles and the anterior parts of the inferotemporal lobes on both sides, predominantly on the left, with some extension to the anterior parts of the medial temporal lobes. There was additional damage to the left insular cortex and its surrounding structures but no evidence of frontal lobe damage on MRIs or cognitive tests. A profound retrograde amnesia may be produced by damage to the bilateral temporal poles and anterior inferotemporal lobes in the absence of frontal lobe pathologies, and a dense and persistent episodic old memory loss can arise even with a relatively small lesion in the right anterior temporal lobe if it is combined with extensive damage to the left.

Expanding role of ureteroscopy and laser lithotripsy for treatment of proximal ureteral and intrarenal calculi.

PubMed

Bagley, Demetrius H

2002-07-01

Ureteroscopy has assumed an expanded and important role in the treatment of proximal ureteral and intrarenal calculi with the development of new endoscopes, more effective grasping devices, and the holmium laser lithotriptor. The success rate for treating proximal ureteral stones with small rigid and flexible ureteroscopes and the holmium laser is well over 90%. Lower pole renal calculi can also be treated with a success rate of approximately 80%, which surpasses that of shock wave lithotripsy. Selected stones that are over 2 cm in diameter, along with branched stones, can also be treated successfully with ureteroscopy. Ureteroscopy is the most successful technique for the treatment of ureteral calculi (success rates >90%) and is an optional treatment for many renal calculi.

Retrograde pyelogram using the flexible cystoscope.

PubMed

Reddy, P K; Hulbert, J C

1986-12-01

A retrograde pyelogram was performed on 2 men with the flexible choledochonephroscope and a 5F whistle-tip ureteral catheter. The procedure was done on an outpatient basis with topical anesthesia and patient tolerance was good. The technique is simple and is a useful alternative to the classical rigid cystoscopic technique.

Rescue percutaneous coronary recanalization of right coronary artery by retrograde approach

PubMed Central

Kameczura, Tomasz; Surowiec, Sławomir; Dudek, Dariusz; Czarnecka, Danuta

2013-01-01

We describe the case of a 62-year-old female patient in whom there was an occlusion of collaterals and acute inferior wall ischemia during the opening procedure of right coronary artery (RCA) chronic total occlusion. Rescue percutaneous coronary intervention (PCI) of RCA by the retrograde approach was performed preventing heart muscle damage. In this article we discuss the issue of PCI by the retrograde technique. PMID:24570712

Corsair microcatheter for retrograde coronary chronic total occlusion recanalization: Early experience outside the realm of dedicated recanalization specialists

PubMed Central

Joseph, George; Thomson, Viji Samuel; Radhakrishnan, Shanmugasundaram

2012-01-01

Objective To determine the extent to which use of the Corsair microcatheter (CM, Asahi Intecc Co., Japan) improves procedural outcomes when an experienced operator who is not a dedicated recanalization specialist attempts retrograde chronic total occlusion (CTO) recanalization through collateral channels during percutaneous coronary intervention. Background The recently introduced CM has improved success rates of retrograde CTO recanalization to nearly 100% in the hands of dedicated coronary recanalization specialists; however, the impact the CM has on the results of non-specialist operators attempting retrograde CTO recanalization is not known. Methods A non-specialist operator attempted CM-assisted recanalization in seven consecutive CTO cases requiring retrograde recanalization. The results obtained were compared with those achieved by the same operator in eleven consecutive retrograde CTO recanalization procedures during the last 2 years before the CM became available. Results CM-assisted retrograde CTO recanalization was successful in 6 of 7 cases (86%), but failed in one case attempted through a tortuous epicardial collateral; there were no complications. In contrast, during the 2 years before the CM became available, retrograde CTO recanalization was successful in only 3 of 11 attempted cases (27%), and was associated with significant morbidity. Lesions in the two groups were comparable in terms of technical difficulty and procedural risk. Conclusions The non-specialist operator's retrograde CTO recanalization results improve significantly when using the CM. Given the effectiveness and safety of CM-assisted retrograde CTO recanalization, operators should be less aggressive with anterograde recanalization attempts, and should switch to the retrograde approach earlier and more often. PMID:22929822

Antegrade Ureteral Stenting is a Good Alternative for the Retrograde Approach

PubMed Central

van der Meer, Rutger W.; Weltings, Saskia; van Erkel, Arian R.; Roshani, Hossain; Elzevier, Henk W.; van Dijk, Lukas C.; van Overhagen, Hans

2017-01-01

Background/Aims Double J (JJ) stents for treating obstructive ureteral pathology are generally inserted through a retrograde route with cystoscopic guidance. Antegrade percutaneous insertion using fluoroscopy can be performed alternatively but is less known. Indications, success rate and complications of antegrade ureteral stenting were evaluated. Methods Data of consecutive patients in which antegrade ureteral stenting was performed were retrospectively analysed using the radiology information system and patient records. Patient characteristics, details of the antegrade JJ stent insertion procedure and registered complications were collected. Furthermore, it was investigated if prior to the antegrade procedure a retrograde attempt for JJ stent insertion was performed. Results Total 130 attempts for antegrade JJ stent insertion were performed in 100 patients. A percutaneous nephrostomy catheter had already been placed in the majority of kidneys (n = 109) for initial treatment of hydronephrosis. Most prevelant indication for a JJ stent was obstructive ureteral pathology due to malignancy (n = 63). A JJ stent was successfully inserted in 125 of 130 procedures. In 21 cases, previous retrograde ureteral stenting had failed but, subsequent antegrade ureteral stenting was successful. There were 8 procedure related complications; 6 infections, 1 false tract and 1 malposition. Conclusion Antegrade percutaneous insertion of a JJ stent is a good alternative for retrograde insertion. PMID:28785193

Antegrade Ureteral Stenting is a Good Alternative for the Retrograde Approach.

PubMed

van der Meer, Rutger W; Weltings, Saskia; van Erkel, Arian R; Roshani, Hossain; Elzevier, Henk W; van Dijk, Lukas C; van Overhagen, Hans

2017-07-01

Double J (JJ) stents for treating obstructive ureteral pathology are generally inserted through a retrograde route with cystoscopic guidance. Antegrade percutaneous insertion using fluoroscopy can be performed alternatively but is less known. Indications, success rate and complications of antegrade ureteral stenting were evaluated. Data of consecutive patients in which antegrade ureteral stenting was performed were retrospectively analysed using the radiology information system and patient records. Patient characteristics, details of the antegrade JJ stent insertion procedure and registered complications were collected. Furthermore, it was investigated if prior to the antegrade procedure a retrograde attempt for JJ stent insertion was performed. Total 130 attempts for antegrade JJ stent insertion were performed in 100 patients. A percutaneous nephrostomy catheter had already been placed in the majority of kidneys (n = 109) for initial treatment of hydronephrosis. Most prevelant indication for a JJ stent was obstructive ureteral pathology due to malignancy (n = 63). A JJ stent was successfully inserted in 125 of 130 procedures. In 21 cases, previous retrograde ureteral stenting had failed but, subsequent antegrade ureteral stenting was successful. There were 8 procedure related complications; 6 infections, 1 false tract and 1 malposition. Antegrade percutaneous insertion of a JJ stent is a good alternative for retrograde insertion.

A versatile nanobody-based toolkit to analyze retrograde transport from the cell surface.

PubMed

Buser, Dominik P; Schleicher, Kai D; Prescianotto-Baschong, Cristina; Spiess, Martin

2018-06-18

Retrograde transport of membranes and proteins from the cell surface to the Golgi and beyond is essential to maintain homeostasis, compartment identity, and physiological functions. To study retrograde traffic biochemically, by live-cell imaging or by electron microscopy, we engineered functionalized anti-GFP nanobodies (camelid VHH antibody domains) to be bacterially expressed and purified. Tyrosine sulfation consensus sequences were fused to the nanobody for biochemical detection of trans -Golgi arrival, fluorophores for fluorescence microscopy and live imaging, and APEX2 (ascorbate peroxidase 2) for electron microscopy and compartment ablation. These functionalized nanobodies are specifically captured by GFP-modified reporter proteins at the cell surface and transported piggyback to the reporters' homing compartments. As an application of this tool, we have used it to determine the contribution of adaptor protein-1/clathrin in retrograde transport kinetics of the mannose-6-phosphate receptors from endosomes back to the trans -Golgi network. Our experiments establish functionalized nanobodies as a powerful tool to demonstrate and quantify retrograde transport pathways.

Retrograde Signals: Integrators of Interorganellar Communication and Orchestrators of Plant Development.

PubMed

de Souza, Amancio; Wang, Jin-Zheng; Dehesh, Katayoon

2017-04-28

Interorganellar cooperation maintained via exquisitely controlled retrograde-signaling pathways is an evolutionary necessity for maintenance of cellular homeostasis. This signaling feature has therefore attracted much research attention aimed at improving understanding of the nature of these communication signals, how the signals are sensed, and ultimately the mechanism by which they integrate targeted processes that collectively culminate in organellar cooperativity. The answers to these questions will provide insight into how retrograde-signal-mediated regulatory mechanisms are recruited and which biological processes are targeted, and will advance our understanding of how organisms balance metabolic investments in growth against adaptation to environmental stress. This review summarizes the present understanding of the nature and the functional complexity of retrograde signals as integrators of interorganellar communication and orchestrators of plant development, and offers a perspective on the future of this critical and dynamic area of research.

Tibiotalocalcaneal arthrodesis using a dynamically locked retrograde intramedullary nail.

PubMed

Pelton, Kevin; Hofer, Jason K; Thordarson, David B

2006-10-01

Tibiotalocalcaneal arthrodesis is an important salvage method for patients with complex hindfoot problems, including Charcot arthropathy, osteonecrosis of the talus, combined arthritis of the ankle and subtalar joint, and failed total ankle arthroplasty. This study evaluated the results of a dynamic retrograde intramedullary nail for fixation with posterior to anterior distal interlocking screws placed through the calcaneus for tibiotalocalcaneal fusion. Thirty-three consecutive tibiotalocalcaneal fusions were done by a single surgeon (DBT) and were stabilized with a dynamic retrograde intramedullary nail. Time to fusion, impaction of the nail relative to the intramedullary canal, nail-tibial angle, and complications were noted. Average followup was 14 months. Twenty-nine of 33 feet (88%) fused at an average of 3.7 months after surgery. Average impaction of the nail was 2.3 (0.5 to 5.0) mm. Cortical hypertrophy at the tip of the rod or at the proximal interlocking screw was noted in 13 of 27 patients. A trend toward a higher nonunion rate was noted in patients with an increased nail-tibial angle. Dynamic retrograde intramedullary nailing for fixation of the tibiotalocalcaneal fusions is a good method of stabilizing this complex fusion construct.

Is retrograde drilling really useful for osteochondral lesion of talus with subchondral cyst?: A case report.

PubMed

Jeong, Seong-Yup; Kim, Jong-Kil; Lee, Kwang-Bok

2016-12-01

Retrograde drilling is a well accepted procedure for osteochondral lesion of the talus and subchondral cyst with intact overlying cartilage. It has good results in most reports. Compared to anterograde drilling, retrograde drilling can protect the integrity of the articular cartilage. The purpose of this study was to evaluate the suitability of using retrograde drilling for osteochondral lesion with subchondral cyst and discuss the mechanism involved in the development of subchondral cyst. We report a 53-year-old man who had complained left ankle pain that lasted over 6 months which was exacerbated by walking. We diagnosed it as osteochondral lesion of the talus with subchondral cyst. Plain X-ray, computed tomography, and magnetic resonance imaging (MRI) of the ankle. He undertook retrograde drilling without debridement of cartilage. After the surgery, the pain had been subsided for 1 year, although arthritic change had progressed. However, after 5 years of retrograde drilling, he revisited our hospital due to severe ankle pain. Plain X-ray and MRI showed arthritic change of the ankle and multiple cystic formation of talus. Retrograde drilling has some problem because this procedure is not theoretically correct when the development of a subchondral cyst in osteochondral lesion of the talus is considered. In addition, retrograde drilling may impair uninjured bone marrow of the talus, resulting in the development of multiple cystic formations.

Anatomical Relationship Between the Kidney Collecting System and the Intrarenal Arteries in the Sheep: Contribution for a New Urological Model.

PubMed

Buys-Gonçalves, Gabriela Faria; De Souza, Diogo Benchimol; Sampaio, Francisco José Barcellos; Pereira-Sampaio, Marco Aurélio

2016-04-01

Previous studies have demonstrated that the pig collecting system heals after partial nephrectomy without closure. Recently, a study in sheep showed that partial nephrectomy without closure of the collecting system resulted in urinary leakage and urinoma. The aim of this study was to present detailed anatomical findings on the intrarenal anatomy of the sheep. Forty two kidneys were used to produce tridimensional endocasts of the collecting system together with the intrarenal arteries. A renal pelvis which displayed 11-19 (mean of 16) renal recesses was present. There were no calices present. The renal artery was singular in each kidney and gave two primary branches one to the dorsal surface and one to ventral surface. Dorsal and ventral branches of the renal artery were classified based on the relationship between their branching pattern and the collecting system as: type I (cranial and caudal segmental arteries), type II (cranial, middle and caudal segmental arteries) or type III (cranial, cranial middle, caudal middle, and caudal segmental arteries). Type I was the most common branching pattern for the dorsal and ventral branches of the renal artery. The arterial supply of the caudal pole of the sheep kidney supports its use as an experimental model due to the similarity to the human kidney. However, the lack of a retropelvic artery discourages the use of the cranial pole in experiments in which the arteries are an important aspect to be considered. © 2016 Wiley Periodicals, Inc.

Real-time Visualization and Quantification of Retrograde Cardioplegia Delivery using Near Infrared Fluorescent Imaging

PubMed Central

Rangaraj, Aravind T.; Ghanta, Ravi K.; Umakanthan, Ramanan; Soltesz, Edward G.; Laurence, Rita G.; Fox, John; Cohn, Lawrence H.; Bolman, R. M.; Frangioni, John V.; Chen, Frederick Y.

2009-01-01

Background and Aim of the Study Homogeneous delivery of cardioplegia is essential for myocardial protection during cardiac surgery. Presently, there exist no established methods to quantitatively assess cardioplegia distribution intraoperatively and determine when retrograde cardioplegia is required. In this study, we evaluate the feasibility of near infrared (NIR) imaging for real-time visualization of cardioplegia distribution in a porcine model. Methods A portable, intraoperative, real-time NIR imaging system was utilized. NIR fluorescent cardioplegia solution was developed by incorporating indocyanine green (ICG) into crystalloid cardioplegia solution. Real-time NIR imaging was performed while the fluorescent cardioplegia solution was infused via the retrograde route in 5 ex-vivo normal porcine hearts and in 5 ex-vivo porcine hearts status post left anterior descending (LAD) coronary artery ligation. Horizontal cross-sections of the hearts were obtained at proximal, middle, and distal LAD levels. Videodensitometry was performed to quantify distribution of fluorophore content. Results The progressive distribution of cardioplegia was clearly visualized with NIR imaging. Complete visualization of retrograde distribution occurred within 4 minutes of infusion. Videodensitometry revealed that retrograde cardioplegia primarily distributed to the left ventricle and anterior septum. In hearts with LAD ligation, antegrade cardioplegia did not distribute to the anterior left ventricle. This deficiency was compensated for with retrograde cardioplegia supplementation. Conclusions Incorporation of ICG into cardioplegia allows real-time visualization of cardioplegia delivery via NIR imaging. This technology may prove useful in guiding intraoperative decisions pertaining to when retrograde cardioplegia is mandated. PMID:19016995

Real-time visualization and quantification of retrograde cardioplegia delivery using near infrared fluorescent imaging.

PubMed

Rangaraj, Aravind T; Ghanta, Ravi K; Umakanthan, Ramanan; Soltesz, Edward G; Laurence, Rita G; Fox, John; Cohn, Lawrence H; Bolman, R M; Frangioni, John V; Chen, Frederick Y

2008-01-01

Homogeneous delivery of cardioplegia is essential for myocardial protection during cardiac surgery. Presently, there exist no established methods to quantitatively assess cardioplegia distribution intraoperatively and determine when retrograde cardioplegia is required. In this study, we evaluate the feasibility of near infrared (NIR) imaging for real-time visualization of cardioplegia distribution in a porcine model. A portable, intraoperative, real-time NIR imaging system was utilized. NIR fluorescent cardioplegia solution was developed by incorporating indocyanine green (ICG) into crystalloid cardioplegia solution. Real-time NIR imaging was performed while the fluorescent cardioplegia solution was infused via the retrograde route in five ex vivo normal porcine hearts and in five ex vivo porcine hearts status post left anterior descending (LAD) coronary artery ligation. Horizontal cross-sections of the hearts were obtained at proximal, middle, and distal LAD levels. Videodensitometry was performed to quantify distribution of fluorophore content. The progressive distribution of cardioplegia was clearly visualized with NIR imaging. Complete visualization of retrograde distribution occurred within 4 minutes of infusion. Videodensitometry revealed retrograde cardioplegia, primarily distributed to the left ventricle (LV) and anterior septum. In hearts with LAD ligation, antegrade cardioplegia did not distribute to the anterior LV. This deficiency was compensated for with retrograde cardioplegia supplementation. Incorporation of ICG into cardioplegia allows real-time visualization of cardioplegia delivery via NIR imaging. This technology may prove useful in guiding intraoperative decisions pertaining to when retrograde cardioplegia is mandated.

Distribution of intrarenal blood flow consequent to left atrial balloon inflation.

PubMed

Passmore, J C; Stremel, R W; Hock, C E; Allen, R L; Bradford, W B

1985-01-01

The effects of inflation of a balloon within, and consequent distension of, the left atrium (LABI, left atrial balloon inflation) on total renal blood flow (RBF) and intrarenal blood flow distribution were measured and compared to values obtained from another group of dogs that were hemorrhaged (HEM) to the same level of hypotension as that produced by LABI, a mean systemic arterial pressure of 88 mm Hg. Kidney wt/kg, RBF/kg body wt, and urine flow were markedly reduced during the hemorrhage period in the HEM group when compared to values obtained during the experimental period for the LABI group. Data from the freeze-dissection (133Xe) analysis revealed that the percentage distribution of blood flow as renal outer cortical (OC) blood flow was less (26%) in the HEM group than in the LABI group (50%), this latter value being very similar to that of control dogs that experienced no hypotension (49%). LABI better maintains OC blood flow and urine flow when compared to HEM at the same systemic blood pressure, suggesting a role for cardiopulmonary receptors in reflex sympathetic control of renal blood flow distribution during hypotension.

Corsair microcatheter for retrograde coronary chronic total occlusion recanalization: early experience outside the realm of dedicated recanalization specialists.

PubMed

Joseph, George; Thomson, Viji Samuel; Radhakrishnan, Shanmugasundaram

2012-01-01

To determine the extent to which use of the Corsair microcatheter (CM, Asahi Intecc Co., Japan) improves procedural outcomes when an experienced operator who is not a dedicated recanalization specialist attempts retrograde chronic total occlusion (CTO) recanalization through collateral channels during percutaneous coronary intervention. The recently introduced CM has improved success rates of retrograde CTO recanalization to nearly 100% in the hands of dedicated coronary recanalization specialists; however, the impact the CM has on the results of non-specialist operators attempting retrograde CTO recanalization is not known. A non-specialist operator attempted CM-assisted recanalization in seven consecutive CTO cases requiring retrograde recanalization. The results obtained were compared with those achieved by the same operator in eleven consecutive retrograde CTO recanalization procedures during the last 2 years before the CM became available. CM-assisted retrograde CTO recanalization was successful in 6 of 7 cases (86%), but failed in one case attempted through a tortuous epicardial collateral; there were no complications. In contrast, during the 2 years before the CM became available, retrograde CTO recanalization was successful in only 3 of 11 attempted cases (27%), and was associated with significant morbidity. Lesions in the two groups were comparable in terms of technical difficulty and procedural risk. The non-specialist operator's retrograde CTO recanalization results improve significantly when using the CM. Given the effectiveness and safety of CM-assisted retrograde CTO recanalization, operators should be less aggressive with anterograde recanalization attempts, and should switch to the retrograde approach earlier and more often. Copyright © 2012 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Intra-renal delivery of mesenchymal stem cells attenuates myocardial injury after reversal of hypertension in porcine renovascular disease.

PubMed

Eirin, Alfonso; Zhu, Xiang-Yang; Ferguson, Christopher M; Riester, Scott M; van Wijnen, Andre J; Lerman, Amir; Lerman, Lilach O

2015-01-19

Percutaneous transluminal renal angioplasty (PTRA) fails to fully improve cardiac injury and dysfunction in patients with renovascular hypertension (RVH). Mesenchymal stem cells (MSCs) restore renal function, but their potential for attenuating cardiac injury after reversal of RVH has not been explored. We hypothesized that replenishment of MSCs during PTRA would improve cardiac function and oxygenation, and decrease myocardial injury in porcine RVH. Pigs were studied after 16 weeks of RVH, RVH treated 4 weeks earlier with PTRA with or without adjunct intra-renal delivery of MSC (10^6 cells), and controls. Cardiac structure, function (fast-computed tomography (CT)), and myocardial oxygenation (Blood-Oxygen-Level-Dependent- magnetic resonance imaging) were assessed in-vivo. Myocardial microvascular density (micro-CT) and myocardial injury were evaluated ex-vivo. Kidney venous and systemic blood levels of inflammatory markers were measured and their renal release calculated. PTRA normalized blood pressure, yet stenotic-kidney glomerular filtration rate, similarly blunted in RVH and RVH + PTRA, normalized only in PTRA + MSC-treated pigs. PTRA attenuated left ventricular remodeling, whereas myocardial oxygenation, subendocardial microvascular density, and diastolic function remained decreased in RVH + PTRA, but normalized in RVH + PTRA-MSC. Circulating isoprostane levels and renal release of inflammatory cytokines increased in RVH and RVH + PTRA, but normalized in RVH + PTRA-MSC, as did myocardial oxidative stress, inflammation, collagen deposition, and fibrosis. Intra-renal MSC delivery during PTRA preserved stenotic-kidney function, reduced systemic oxidative stress and inflammation, and thereby improved cardiac function, oxygenation, and myocardial injury four weeks after revascularization, suggesting a therapeutic potential for adjunctive MSC delivery to preserve cardiac function and structure after reversal of experimental RVH.

Endosome-mediated retrograde axonal transport of P2X3 receptor signals in primary sensory neurons

PubMed Central

Chen, Xu-Qiao; Wang, Bin; Wu, Chengbiao; Pan, Jin; Yuan, Bo; Su, Yuan-Yuan; Jiang, Xing-Yu; Zhang, Xu; Bao, Lan

2012-01-01

Neurotrophins and their receptors adopt signaling endosomes to transmit retrograde signals. However, the mechanisms of retrograde signaling for other ligand/receptor systems are poorly understood. Here, we report that the signals of the purinergic (P)2X3 receptor, an ATP-gated ion channel, are retrogradely transported in dorsal root ganglion (DRG) neuron axons. We found that Rab5, a small GTPase, controls the early sorting of P2X3 receptors into endosomes, while Rab7 mediates the fast retrograde transport of P2X3 receptors. Intraplantar injection and axonal application into the microfluidic chamber of α, β-methylene-ATP (α, β-MeATP), a P2X selective agonist, enhanced the endocytosis and retrograde transport of P2X3 receptors. The α, β-MeATP-induced Ca2+ influx activated a pathway comprised of protein kinase C, rat sarcoma viral oncogene and extracellular signal-regulated protein kinase (ERK), which associated with endocytic P2X3 receptors to form signaling endosomes. Disruption of the lipid rafts abolished the α, β-MeATP-induced ERK phosphorylation, endocytosis and retrograde transport of P2X3 receptors. Furthermore, treatment of peripheral axons with α, β-MeATP increased the activation level of ERK and cAMP response element-binding protein in the cell bodies of DRG neurons and enhanced neuronal excitability. Impairment of either microtubule-based axonal transport in vivo or dynein function in vitro blocked α, β-MeATP-induced retrograde signals. These results indicate that P2X3 receptor-activated signals are transmitted via retrogradely transported endosomes in primary sensory neurons and provide a novel signaling mechanism for ligand-gated channels. PMID:22157653

Endosome-mediated retrograde axonal transport of P2X3 receptor signals in primary sensory neurons.

PubMed

Chen, Xu-Qiao; Wang, Bin; Wu, Chengbiao; Pan, Jin; Yuan, Bo; Su, Yuan-Yuan; Jiang, Xing-Yu; Zhang, Xu; Bao, Lan

2012-04-01

Neurotrophins and their receptors adopt signaling endosomes to transmit retrograde signals. However, the mechanisms of retrograde signaling for other ligand/receptor systems are poorly understood. Here, we report that the signals of the purinergic (P)2X(3) receptor, an ATP-gated ion channel, are retrogradely transported in dorsal root ganglion (DRG) neuron axons. We found that Rab5, a small GTPase, controls the early sorting of P2X(3) receptors into endosomes, while Rab7 mediates the fast retrograde transport of P2X(3) receptors. Intraplantar injection and axonal application into the microfluidic chamber of α, β-methylene-ATP (α, β-MeATP), a P2X selective agonist, enhanced the endocytosis and retrograde transport of P2X(3) receptors. The α, β-MeATP-induced Ca(2+) influx activated a pathway comprised of protein kinase C, rat sarcoma viral oncogene and extracellular signal-regulated protein kinase (ERK), which associated with endocytic P2X(3) receptors to form signaling endosomes. Disruption of the lipid rafts abolished the α, β-MeATP-induced ERK phosphorylation, endocytosis and retrograde transport of P2X(3) receptors. Furthermore, treatment of peripheral axons with α, β-MeATP increased the activation level of ERK and cAMP response element-binding protein in the cell bodies of DRG neurons and enhanced neuronal excitability. Impairment of either microtubule-based axonal transport in vivo or dynein function in vitro blocked α, β-MeATP-induced retrograde signals. These results indicate that P2X(3) receptor-activated signals are transmitted via retrogradely transported endosomes in primary sensory neurons and provide a novel signaling mechanism for ligand-gated channels.

Osteochondritis Dissecans Involving the Trochlear Groove Treated With Retrograde Drilling

PubMed Central

Kaji, Yoshio; Nakamura, Osamu; Yamaguchi, Konosuke; Yamamoto, Tetsuji

2015-01-01

Abstract Osteochondritis dissecans (OCD) occurs frequently in the humeral capitellum of the upper extremity, whereas OCD involving the trochlear groove (trochlear groove OCD) is rarely reported. A standard treatment for trochlear groove OCD has therefore not been determined, although several methods have been tried. The case of a 14-year-old male gymnast with bilateral trochlear groove OCD is presented. Retrograde drilling from the lateral condyle of the humerus was applied for the OCD lesion of the left elbow, since it was larger in size than that in the right elbow and was symptomatic. Conversely, since the right lesion was small and asymptomatic, it was managed conservatively. After treatment, consolidation of the OCD lesions was observed in both elbows. However, the time to healing was shorter in the left elbow treated surgically than in the right elbow managed conservatively. In conclusion, retrograde drilling is a very simple and minimally invasive treatment. This case suggests that retrograde drilling for trochlear groove OCD may be a useful procedure that may accelerate the healing process for OCD lesions. PMID:26356703

Functional retrograde amnesia: a multiple case study.

PubMed

Fujiwara, Esther; Brand, Matthias; Kracht, Lutz; Kessler, Josef; Diebel, Andrea; Netz, Johannes; Markowitsch, Hans J

2008-01-01

Functional retrograde amnesia (RA) is a rare pathology and has been rarely studied in detail across different patients. We extensively examined five functional RA patients and compared their neuropsychological profile including anterograde and retrograde memory performance, executive functions, emotional processing, and formally assessed psychiatric symptoms. Across patients, neuropsychological deficits beyond RA were most consistently seen in executive functions and attention suggesting that these dysfunctions contribute to the remote memory deficit. In a majority of the patients, problems in social cognition and emotional behaviour were reflected in Theory of Mind deficits and accompanying psychiatric symptoms. Aberrances in a measure of social desirability were detected, pointing to repressive tendencies in three out of the five patients. Future studies of functional RA patients may investigate more specifically which frontal-lobe associated (dys-) functions contribute to the memory retrieval deficit. Moreover, studying more closely the interaction between social cognition, repressive personality style and memory inhibition in this disease seems worthwhile pursuing.

Transport According to GARP: Receiving Retrograde Cargo at the Trans-Golgi Network

PubMed Central

Bonifacino, Juan S.; Hierro, Aitor

2010-01-01

Tethering factors are large protein complexes that capture transport vesicles and enable their fusion with acceptor organelles at different stages of the endomembrane system. Recent studies have shed new light on the structure and function of a heterotetrameric tethering factor named Golgi-associated retrograde protein (GARP), which promotes fusion of endosome-derived, retrograde transport carriers to the trans-Golgi network (TGN). X-ray crystallography of the Vps53 and Vps54 subunits of GARP has revealed that this complex is structurally related to other tethering factors such as the exocyst, COG and Dsl1, indicating that they all might work by a similar mechanism. Loss of GARP function compromises the growth, fertility and/or viability of the defective organisms, underscoring the essential nature of GARP-mediated retrograde transport. PMID:21183348

Biomechanical Strength of Retrograde Fixation in Proximal Third Scaphoid Fractures.

PubMed

Daly, Charles A; Boden, Allison L; Hutton, William C; Gottschalk, Michael B

2018-04-01

Current techniques for fixation of proximal pole scaphoid fractures utilize antegrade fixation via a dorsal approach endangering the delicate vascular supply of the dorsal scaphoid. Volar and dorsal approaches demonstrate equivalent clinical outcomes in scaphoid wrist fractures, but no study has evaluated the biomechanical strength for fractures of the proximal pole. This study compares biomechanical strength of antegrade and retrograde fixation for fractures of the proximal pole of the scaphoid. A simulated proximal pole scaphoid fracture was produced in 22 matched cadaveric scaphoids, which were then assigned randomly to either antegrade or retrograde fixation with a cannulated headless compression screw. Cyclic loading and load to failure testing were performed and screw length, number of cycles, and maximum load sustained were recorded. There were no significant differences in average screw length (25.5 mm vs 25.6 mm, P = .934), average number of cyclic loading cycles (3738 vs 3847, P = .552), average load to failure (348 N vs 371 N, P = .357), and number of catastrophic failures observed between the antegrade and retrograde fixation groups (3 in each). Practical equivalence between the 2 groups was calculated and the 2 groups were demonstrated to be practically equivalent (upper threshold P = .010). For this model of proximal pole scaphoid wrist fractures, antegrade and retrograde screw configuration have been proven to be equivalent in terms of biomechanical strength. With further clinical study, we hope surgeons will be able to make their decision for fixation technique based on approaches to bone grafting, concern for tenuous blood supply, and surgeon preference without fear of poor biomechanical properties.

Management of Endovascular Aortic Aneurysm Complications via Retrograde Catheterization Through the Distal Stent-Graft Landing Zone.

PubMed

Zhang, Xicheng; Sun, Yuan; Chen, Zhaolei; Jing, Yuanhu; Xu, Miao

2017-08-01

A retrograde technique through the gap between the distal stent landing zone and the iliac artery wall has been applied to treat type II endoleak after endovascular aortic aneurysm repair (EVAR). In this study, we tried to investigate its efficacy in the management of type III endoleak and intraoperative accidental events. We reported 2 complications of EVAR that were difficult to treat with conventional methods. One patient had a sustained type III endoleak after EVAR, and the right renal artery was accidentally sealed by a graft stent in the other patient during the operation. Both complications were managed by the retrograde technique from the distal stent landing zone. In the first case, the endoleak was easily embolized by the retrograde catheterization technique, and in the second case, a stent was implanted in the right renal artery using the retrograde technique to restore blood flow. In some EVAR cases, the technique of retrograde catheterization through the distal stent-graft landing zone is feasible, safe, and easy to perform.

Retrograde CTO-PCI of Native Coronary Arteries Via Left Internal Mammary Artery Grafts: Insights From a Multicenter U.S. Registry.

PubMed

Tajti, Peter; Karatasakis, Aris; Karmpaliotis, Dimitri; Alaswad, Khaldoon; Jaffer, Farouc A; Yeh, Robert W; Patel, Mitul; Mahmud, Ehtisham; Choi, James W; Doing, Anthony H; Toma, Catalin; Uretsky, Barry; Garcia, Santiago; Moses, Jeffrey W; Parikh, Manish; Kirtane, Ajay; Ali, Ziad A; Hatem, Raja; Karacsonyi, Judit; Danek, Barbara A; Rangan, Bavana V; Banerjee, Subhash; Ungi, Imre; Brilakis, Emmanouil S

2018-03-01

Retrograde percutaneous coronary intervention (PCI) of native coronary artery chronic total occlusion (CTO) via left internal mammary artery (LIMA) graft has received limited study. We compared the clinical and procedural characteristics and outcomes of retrograde CTO-PCI through LIMA grafts vs other conduits in a contemporary multicenter CTO registry. The LIMA was used as the collateral channel in 20 of 990 retrograde CTO-PCIs (2.02%) performed at 18 United States centers. The mean age of the study patients was 69 ± 7 years and 95% were men. The most common CTO target vessel was the right coronary artery (55%). The mean J-CTO score in the LIMA group was high (3.45 ± 0.76). The technical success rates were 70% for retrograde PCI via LIMA graft vs 81.05% for retrograde via other conduits (P=.25), while procedural success rates were 70% for retrograde PCI via LIMA graft and 78.19% for retrograde via other conduits (P=.41). The incidence of major in-hospital complications was also similar between the LIMA and non-LIMA retrograde groups (5% vs 6%; P>.99). Use of guide-catheter extensions (40% vs 28%; P=.22), intravascular ultrasound (45% vs 31%; P=.20), and left ventricular assist devices (24% vs 10%; P=.08) was numerically higher in retrograde CTO-PCIs via LIMA grafts. Retrograde CTO-PCI is infrequently performed via LIMA grafts and is associated with similar success and major in-hospital complication rates as retrograde CTO-PCI performed via other conduits.

The SAL-PAP Chloroplast Retrograde Pathway Contributes to Plant Immunity by Regulating Glucosinolate Pathway and Phytohormone Signaling.

PubMed

Ishiga, Yasuhiro; Watanabe, Mutsumi; Ishiga, Takako; Tohge, Takayuki; Matsuura, Takakazu; Ikeda, Yoko; Hoefgen, Rainer; Fernie, Alisdair R; Mysore, Kirankumar S

2017-10-01

Chloroplasts have a crucial role in plant immunity against pathogens. Increasing evidence suggests that phytopathogens target chloroplast homeostasis as a pathogenicity mechanism. In order to regulate the performance of chloroplasts under stress conditions, chloroplasts produce retrograde signals to alter nuclear gene expression. Many signals for the chloroplast retrograde pathway have been identified, including chlorophyll intermediates, reactive oxygen species, and metabolic retrograde signals. Although there is a reasonably good understanding of chloroplast retrograde signaling in plant immunity, some signals are not well-understood. In order to understand the role of chloroplast retrograde signaling in plant immunity, we investigated Arabidopsis chloroplast retrograde signaling mutants in response to pathogen inoculation. sal1 mutants (fry1-2 and alx8) responsible for the SAL1-PAP retrograde signaling pathway showed enhanced disease symptoms not only to the hemibiotrophic pathogen Pseudomonas syringae pv. tomato DC3000 but, also, to the necrotrophic pathogen Pectobacterium carotovorum subsp. carotovorum EC1. Glucosinolate profiles demonstrated the reduced accumulation of aliphatic glucosinolates in the fry1-2 and alx8 mutants compared with the wild-type Col-0 in response to DC3000 infection. In addition, quantification of multiple phytohormones and analyses of their gene expression profiles revealed that both the salicylic acid (SA)- and jasmonic acid (JA)-mediated signaling pathways were down-regulated in the fry1-2 and alx8 mutants. These results suggest that the SAL1-PAP chloroplast retrograde pathway is involved in plant immunity by regulating the SA- and JA-mediated signaling pathways.

Regulation of mitochondria-dynactin interaction and mitochondrial retrograde transport in axons.

PubMed

Drerup, Catherine M; Herbert, Amy L; Monk, Kelly R; Nechiporuk, Alex V

2017-04-17

Mitochondrial transport in axons is critical for neural circuit health and function. While several proteins have been found that modulate bidirectional mitochondrial motility, factors that regulate unidirectional mitochondrial transport have been harder to identify. In a genetic screen, we found a zebrafish strain in which mitochondria fail to attach to the dynein retrograde motor. This strain carries a loss-of-function mutation in actr10 , a member of the dynein-associated complex dynactin. The abnormal axon morphology and mitochondrial retrograde transport defects observed in actr10 mutants are distinct from dynein and dynactin mutant axonal phenotypes. In addition, Actr10 lacking the dynactin binding domain maintains its ability to bind mitochondria, arguing for a role for Actr10 in dynactin-mitochondria interaction. Finally, genetic interaction studies implicated Drp1 as a partner in Actr10-dependent mitochondrial retrograde transport. Together, this work identifies Actr10 as a factor necessary for dynactin-mitochondria interaction, enhancing our understanding of how mitochondria properly localize in axons.

A new link between the retrograde actin flow and focal adhesions.

PubMed

Yamashiro, Sawako; Watanabe, Naoki

2014-11-01

The retrograde actin flow, continuous centripetal movement of the cell peripheral actin networks, is widely observed in adherent cells. The retrograde flow is believed to facilitate cell migration when linked to cell adhesion molecules. In this review, we summarize our current knowledge regarding the functional relationship between the retrograde actin flow and focal adhesions (FAs). We also introduce our recent study in which single-molecule speckle (SiMS) microscopy dissected the complex interactions between FAs and the local actin flow. FAs do not simply impede the actin flow, but actively attract and remodel the local actin network. Our findings provide a new insight into the mechanisms for protrusion and traction force generation at the cell leading edge. Furthermore, we discuss possible roles of the actin flow-FA interaction based on the accumulated knowledge and our SiMS study. © The Authors 2014. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Dynamical lifetimes of asteroids in retrograde orbits

NASA Astrophysics Data System (ADS)

Kankiewicz, Paweł; Włodarczyk, Ireneusz

2017-07-01

The population of known minor bodies in retrograde orbits (I > 90°) that are classified as asteroids is still growing. The aim of our study was to estimate the dynamical lifetimes of these bodies using the latest observational data, including astrometry and physical properties. We selected 25 asteroids with the best-determined orbital elements. We studied their dynamical evolution in the past and future for ±100 Myr (±1 Gyr for three particular cases). We first used orbit determination and cloning to produce swarms of test particles. These swarms were then input into long-term numerical integrations, and the orbital elements were averaged. Next, we collected the available thermal properties of our objects and we used them in an enhanced dynamical model with Yarkovsky forces. We also used a gravitational model for comparison. Finally, we estimated the median lifetimes of 25 asteroids. We found three objects whose retrograde orbits were stable with a dynamical lifetime τ ˜ 10-100 Myr. A large portion of the objects studied displayed smaller values of τ (τ ˜ 1 Myr). In addition, we studied the possible influence of the Yarkovsky effect on our results. We found that the Yarkovsky effect can have a significant influence on the lifetimes of asteroids in retrograde orbits. Because of the presence of this effect, it is possible that the median lifetimes of these objects are extended. Additionally, the changes in orbital elements, caused by Yarkovsky forces, appear to depend on the integration direction. To explain this more precisely, the same model based on new physical parameters, determined from future observations, will be required.

Periprocedural ischaemia during recanalisation of chronic total coronary occlusions: the influence of the transcollateral retrograde approach.

PubMed

Werner, Gerald S; Coenen, Anja; Tischer, Karl-Heinz

2014-11-01

Percutaneous coronary intervention for chronic total coronary occlusions (CTO) becomes increasingly more complex with the transcollateral retrograde approach. This study assesses the effect of the retrograde approach on markers of ischaemia and clinical events. Four hundred and ninety-two consecutive procedures in 392 patients were prospectively evaluated. Before and within 18-24 hours after the PCI creatine kinase (CK) and cardiac troponin I (cTnI) were obtained. A CK increase of greater than three times the upper limit of normal (ULN) was considered a periprocedural MI. Patients with initially elevated cTnI were excluded. In 106 patients with a retrograde wire passage of the septal collaterals, the incidence of a CK or TnI increase was higher as compared to the antegrade group. Patients with septal dilatation or passage of a dilatation catheter (Corsair) showed the highest cTnI. There was no difference in cardiac death or cerebral complications between the groups with antegrade and retrograde approach within the first 30 days. Complex retrograde recanalisation procedures for CTOs lead to an increased periprocedural ischaemic burden, most likely due to obstruction of the collateral pathway, and to the increased plaque burden of complex lesions treated with the retrograde approach.

Psychogenic amnesia: syndromes, outcome, and patterns of retrograde amnesia.

PubMed

Harrison, Neil A; Johnston, Kate; Corno, Federica; Casey, Sarah J; Friedner, Kimberley; Humphreys, Kate; Jaldow, Eli J; Pitkanen, Mervi; Kopelman, Michael D

2017-09-01

There are very few case series of patients with acute psychogenic memory loss (also known as dissociative/functional amnesia), and still fewer studies of outcome, or comparisons with neurological memory-disordered patients. Consequently, the literature on psychogenic amnesia is somewhat fragmented and offers little prognostic value for individual patients. In the present study, we reviewed the case records and neuropsychological findings in 53 psychogenic amnesia cases (ratio of 3:1, males:females), in comparison with 21 consecutively recruited neurological memory-disordered patients and 14 healthy control subjects. In particular, we examined the pattern of retrograde amnesia on an assessment of autobiographical memory (the Autobiographical Memory Interview). We found that our patients with psychogenic memory loss fell into four distinct groups, which we categorized as: (i) fugue state; (ii) fugue-to-focal retrograde amnesia; (iii) psychogenic focal retrograde amnesia following a minor neurological episode; and (iv) patients with gaps in their memories. While neurological cases were characterized by relevant neurological symptoms, a history of a past head injury was actually more common in our psychogenic cases (P = 0.012), perhaps reflecting a 'learning episode' predisposing to later psychological amnesia. As anticipated, loss of the sense of personal identity was confined to the psychogenic group. However, clinical depression, family/relationship problems, financial/employment problems, and failure to recognize the family were also statistically more common in that group. The pattern of autobiographical memory loss differed between the psychogenic groups: fugue cases showed a severe and uniform loss of memories for both facts and events across all time periods, whereas the two focal retrograde amnesia groups showed a 'reversed' temporal gradient with relative sparing of recent memories. After 3-6 months, the fugue patients had improved to normal scores for facts

[Surgical treatment for liver haematoma following endoscopic retrograde cholangiopancreatography; An unusual case].

PubMed

González-López, Rogelio; García-Cano, Eugenio; Espinosa-González, Omar; Cruz-Salgado, Ángel; Montiel-Jarquin, Álvaro-José; Hernández-Zamora, Valeria

2015-01-01

Even in expert hands, there can be serious complications when performing an endoscopic retrograde cholangiopancreatography. The most frequent complications are pancreatitis, cholangitis, bleeding, perforation, and acute cholecystitis. The hepatic subcapsular haematoma is a rare complication, with few cases described worldwide. A case is presented of an extremely rare complication of endoscopic retrograde cholangiopancreatography, which required surgical treatment for its resolution without success. This is second case of mortality reported in the literature. Female patient of 30 years old, with indication for endoscopic retrograde cholangiopancreatography due to benign strictures. A hydro-pneumatic dilation and stent placement of 2 gauge 10 fr was performed. She presented abdominal pain after the procedure and significant decline in haemoglobin with no evidence of haemodynamic instability so an abdominal tomography scan was performed, showing no evidence of liver injury. The patient was haemodynamic unstable within 72 h. A laparotomy was required for damage control, with fatal outcome in the intensive care unit due to multiple organ failure. Subcapsular hepatic haematoma after endoscopic retrograde cholangiopancreatography is a rare complication, with few cases reported in the literature. Treatment described in the literature is conservative, resulting in a satisfactory resolution. Copyright © 2015. Published by Masson Doyma México S.A.

Impact of Retrograde Arch Extension in Acute Type B Aortic Dissection on Management and Outcomes.

PubMed

Nauta, Foeke J H; Tolenaar, Jip L; Patel, Himanshu J; Appoo, Jehangir J; Tsai, Thomas T; Desai, Nimesh D; Montgomery, Daniel G; Mussa, Firas F; Upchurch, Gilbert R; Fattori, Rosella; Hughes, G Chad; Nienaber, Christoph A; Isselbacher, Eric M; Eagle, Kim A; Trimarchi, Santi

2016-12-01

Optimal management of acute type B aortic dissection with retrograde arch extension is controversial. The effect of retrograde arch extension on operative and long-term mortality has not been studied and is not incorporated into clinical treatment pathways. The International Registry of Acute Aortic Dissection was queried for all patients presenting with acute type B dissection and an identifiable primary intimal tear. Outcomes were stratified according to management for patients with and without retrograde arch extension. Kaplan-Meier survival curves were constructed. Between 1996 and 2014, 404 patients (mean age, 63.3 ± 13.9 years) were identified. Retrograde arch extension existed in 67 patients (16.5%). No difference in complicated presentation was noted (36.8% vs 31.7%, p = 0.46), as defined by limb or organ malperfusion, coma, rupture, and shock. Patients with or without retrograde arch extension received similar treatment, with medical management in 53.7% vs 56.5% (p = 0.68), endovascular treatment in 32.8% vs 31.1% (p = 0.78), open operation in 11.9% vs 9.5% (p = 0.54), or hybrid approach in 1.5% vs 3.0% (p = 0.70), respectively. The in-hospital mortality rate was similar for patients with (10.7%) and without (10.4%) retrograde arch extension (p = 0.96), and 5-year survival was also similar at 78.3% and 77.8%, respectively (p = 0.27). The incidence of retrograde arch dissection involves approximately 16% of patients with acute type B dissection. In the International Registry of Acute Aortic Dissection, this entity seems not to affect management strategy or early and late death. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Malingering and retrograde amnesia: the historic case of the Collegno amnesic.

PubMed

Zago, Stefano; Sartori, Giuseppe; Scarlato, Guglielmo

2004-06-01

Assessment of feigned cognitive disorders is an important field of neuropsychology because of its applications to forensic settings. Strategies for detecting malingering in amnesia are available for anterograde amnesia. Less attention has been given to malingering in retrograde amnesia. The case of the 'Smemorato di Collegno' (The Collegno Amnesic) is probably the most famous case of malingered retrograde amnesia ever known in Italy. In 1926, a man who appeared to have lost all his autobiographical memories and identity spent nearly a year in the Collegno asylum of Turin without a name. He was later initially identified as Giulio Canella, Director of the 'Scuola Normale di Verona' who had disappeared during the war in 1916. He was suspected of later identified as being Mario Bruneri, a petty crook from Turin who played the part of an amnesic whose retrograde memory gradually returned. A lengthy investigation was required before this conclusion was reached. Several clinicians and renowned academics evaluated the case, but only Alfredo Coppola, diagnosed "malingered retrograde amnesia" using a method that was extremely innovative for the times. The aim of the present paper is to review the original cognitive evaluation and the strategies used for malingering detection in the "Collegno case". The outcome of the case is then discussed in the light of present-day forensic neuropsychology and the level of advancement of mental examination achieved in the 1920s in Europe is highlighted.

Transcutaneous pleural biopsy with a retrograde forceps: a novel approach.

PubMed

Wiewiorski, Martin; Hiebinger, Andreas; Hoechel, Sebastian; Müller-Gerbl, Magdalena; Barg, Alexej; Valderrabano, Victor; Hügle, Thomas

2016-01-01

Pleural biopsies are commonly performed to investigate the cause of exudative pleural effusion. Biopsy needles (e.g. Abrams needle, Cope needle) are traditionally used to perform the biopsy. However, certain complications such as pneumothorax and haemothorax have been described. We present a technique utilizing a novel retrograde forceps, which could improve the simplicity and lower the complication rate of performing closed pleural biopsies. A retrograde forceps (Retroforceps, Karl Storz, Tuttlingen, Germany) was used to perform 20 transcutaneous pleural biopsies in a cadaver thorax under thoracoscopical control. Video documentation of the procedure from outside and inside the thorax was performed. The surgeon performing the biopsy was blinded to the thoracoscopical view. After the removal of the forceps, it was checked whether biopsy material was retrieved. The video material was retrospectively used to confirm whether the biopsy was taken from the pleura parietalis. Biopsy material was retrieved in 19 out of 20 biopsy attempts. Video material confirmed that the biopsy was taken from the pleura parietalis in all cases. Using a retrograde biopsy forceps is a simple and practicable procedure suitable for clinical application. This technique could potentially reduce the incidence of pneumothorax.

Effect of non-invasive remote ischemic preconditioning on intra-renal perfusion in volunteers.

PubMed

Robert, René; Vinet, Mathieu; Jamet, Angéline; Coudroy, Rémi

2017-06-01

Remote ischemic preconditioning may attenuate renal injury and protect the kidney during subsequent inflammatory or ischemic stress. However, the mechanism of such a protection is not well understood. The aim of this study was to investigate the impact of remote ischemic preconditioning on renal resistivity index (RRI) in nine healthy volunteers. In six volunteers, four cycles of 4-min inflation of a blood pressure cuff were applied to one upper arm, followed by 4-min reperfusion with the cuff deflated. RRI was determined using Doppler echography during each cuff deflated period. Measures were also performed in three volunteers without preconditioning. The median value of RRI significantly decreased progressively from 0.59 [0.53-0.62] before the remote conditioning (baseline) to 0.49 [0.46-0.53] at the end of the experiment (p < 0.001) whereas there was no change in controls. In this study, for the first time, we have clearly shown in a small group of subjects that remote ischemic preconditioning can induce a significantly decrease in RRI through increased intra-renal perfusion.

Geldanamycin Enhances Retrograde Transport of Shiga Toxin in HEp-2 Cells

PubMed Central

Simm, Roger; Torgersen, Maria Lyngaas; Sandvig, Kirsten

2015-01-01

The heat shock protein 90 (Hsp90) inhibitor geldanamycin (GA) has been shown to alter endosomal sorting, diverting cargo destined for the recycling pathway into the lysosomal pathway. Here we investigated whether GA also affects the sorting of cargo into the retrograde pathway from endosomes to the Golgi apparatus. As a model cargo we used the bacterial toxin Shiga toxin, which exploits the retrograde pathway as an entry route to the cytosol. Indeed, GA treatment of HEp-2 cells strongly increased the Shiga toxin transport to the Golgi apparatus. The enhanced Golgi transport was not due to increased endocytic uptake of the toxin or perturbed recycling, suggesting that GA selectively enhances endosomal sorting into the retrograde pathway. Moreover, GA activated p38 and both inhibitors of p38 or its substrate MK2 partially counteracted the GA-induced increase in Shiga toxin transport. Thus, our data suggest that GA-induced p38 and MK2 activation participate in the increased Shiga toxin transport to the Golgi apparatus. PMID:26017782

Loss of Huntingtin stimulates capture of retrograde dense-core vesicles to increase synaptic neuropeptide stores.

PubMed

Bulgari, Dinara; Deitcher, David L; Levitan, Edwin S

2017-08-01

The Huntington's disease protein Huntingtin (Htt) regulates axonal transport of dense-core vesicles (DCVs) containing neurotrophins and neuropeptides. DCVs travel down axons to reach nerve terminals where they are either captured in synaptic boutons to support later release or reverse direction to reenter the axon as part of vesicle circulation. Currently, the impact of Htt on DCV dynamics in the terminal is unknown. Here we report that knockout of Drosophila Htt selectively reduces retrograde DCV flux at proximal boutons of motoneuron terminals. However, initiation of retrograde transport at the most distal bouton and transport velocity are unaffected suggesting that synaptic capture rate of these retrograde DCVs could be altered. In fact, tracking DCVs shows that retrograde synaptic capture efficiency is significantly elevated by Htt knockout or knockdown. Furthermore, synaptic boutons contain more neuropeptide in Htt knockout larvae even though bouton size, single DCV fluorescence intensity, neuropeptide release in response to electrical stimulation and subsequent activity-dependent capture are unaffected. Thus, loss of Htt increases synaptic capture as DCVs travel by retrograde transport through boutons resulting in reduced transport toward the axon and increased neuropeptide in the terminal. These results therefore identify native Htt as a regulator of synaptic capture and neuropeptide storage. Copyright © 2017 Elsevier GmbH. All rights reserved.

Healthy live birth using theophylline in a case of retrograde ejaculation and absolute asthenozoospermia.

PubMed

Ebner, Thomas; Shebl, Omar; Mayer, Richard Bernhard; Moser, Marianne; Costamoling, Walter; Oppelt, Peter

2014-02-01

To analyze whether the use of ready-to-use theophylline is a feasible option in a case of retrograde ejaculation and absolute asthenozoospermia. Case report. In vitro fertilization unit of a public hospital. Thirty-one-year-old nulliparous woman, and 39-year-old male with retrograde ejaculation and absolute asthenozoospermia. Retrieval of postejaculatory urine, restoration of motility using a methylxanthine, intracytoplasmic sperm injection, single-embryo transfer. Sperm motility, fertilization, embryo quality, live birth. Successful fertilization and a single-embryo transfer resulted in a healthy live birth. Theophylline turned out to be a safe, efficient agent for stimulating immotile spermatozoa in patients with retrograde ejaculation. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Percutaneous nephrolithotomy in an 8-week-old infant.

PubMed

Lee, Albert S; Bowen, Diana K; Vatsky, Seth; Zderic, Stephen A; Tasian, Gregory E

2018-06-01

We report successful percutaneous nephrolithotomy (PCNL) in an 8-week-old, 4.12 kg infant with a combined stone burden of > 2 cm in a solitary kidney. The patient was born with thoracolumbar myelomeningocele and had developed recurrent urinary tract infections. Her size precluded retrograde intrarenal surgery and shockwave lithotripsy would be unlikely to clear the stone burden. Stone analysis revealed hydroxyapatite and carbonate apatite stones, and metabolic work up revealed hypercalciuria for which chlorothiazide was started. To our knowledge, this is the youngest patient to undergo PCNL reported in the literature.

On remembering and forgetting our autobiographical pasts: retrograde amnesia and Andrew Mayes's contribution to neuropsychological method.

PubMed

Kopelman, M D; Bright, P

2012-11-01

Andrew Mayes's contribution to the neuropsychology of memory has consisted in steadily teasing out the nature of the memory deficit in the amnesic syndrome. This has been done with careful attention to matters of method at all stages. This particularly applies to his investigations of forgetting rates in amnesia and to his studies of retrograde amnesia. Following a brief outline of his work, the main current theories of retrograde amnesia are considered: consolidation theory, episodic-to-semantic shift theory, and multiple trace theory. Findings across the main studies in Alzheimer dementia are reviewed to illustrate what appears to be consistently found, and what is much more inconsistent. A number of problems and issues in current theories are then highlighted--including the nature of the temporal gradient, correlations with the extent of temporal lobe damage, what we would expect 'normal' remote memory curves to look like, how they would appear in focal retrograde amnesia, and whether we can pinpoint retrograde amnesia to hippocampal/medial temporal damage on the basis of existing studies. A recent study of retrograde amnesia is re-analysed to demonstrate temporal gradients on recollected episodic memories in hippocampal/medial temporal patients. It is concluded that there are two requirements for better understanding of the nature of retrograde amnesia: (i) a tighter, Mayesian attention to method in terms of both the neuropsychology and neuroimaging in investigations of retrograde amnesia; and (ii) acknowledging that there may be multiple factors underlying a temporal gradient, and that episodic and semantic memory show important interdependencies at both encoding and retrieval. Such factors may be critical to understanding what is remembered and what is forgotten from our autobiographical pasts. Copyright © 2012 Elsevier Ltd. All rights reserved.

Axonal autophagosomes recruit dynein for retrograde transport through fusion with late endosomes

PubMed Central

Cheng, Xiu-Tang; Zhou, Bing; Lin, Mei-Yao; Cai, Qian

2015-01-01

Efficient degradation of autophagic vacuoles (AVs) via lysosomes is an important cellular homeostatic process. This is particularly challenging for neurons because mature acidic lysosomes are relatively enriched in the soma. Although dynein-driven retrograde transport of AVs was suggested, a fundamental question remains how autophagosomes generated at distal axons acquire dynein motors for retrograde transport toward the soma. In this paper, we demonstrate that late endosome (LE)–loaded dynein–snapin complexes drive AV retrograde transport in axons upon fusion of autophagosomes with LEs into amphisomes. Blocking the fusion with syntaxin17 knockdown reduced recruitment of dynein motors to AVs, thus immobilizing them in axons. Deficiency in dynein–snapin coupling impaired AV transport, resulting in AV accumulation in neurites and synaptic terminals. Altogether, our study provides the first evidence that autophagosomes recruit dynein through fusion with LEs and reveals a new motor–adaptor sharing mechanism by which neurons may remove distal AVs engulfing aggregated proteins and dysfunctional organelles for efficient degradation in the soma. PMID:25940348

Distant retrograde orbits for the Moon's exploration

NASA Astrophysics Data System (ADS)

Sidorenko, Vladislav

We discuss the properties of the distant retrograde orbits (which are called quasi-satellite orbits also) around Moon. For the first time the distant retrograde orbits were described by J.Jackson in studies on restricted three body problem at the beginning of 20th century [1]. In the synodic (rotating) reference frame distant retrograde orbit looks like an ellipse whose center is slowly drifting in the vicinity of minor primary body while in the inertial reference frame the third body is orbiting the major primary body. Although being away the Hill sphere the third body permanently stays close enough to the minor primary. Due to this reason the distant retrograde orbits are called “quasi-satellite” orbits (QS-orbits) too. Several asteroids in solar system are in a QS-orbit with respect to one of the planet. As an example we can mention the asteroid 2002VE68 which circumnavigates Venus [2]. Attention of specialists in space flight mechanics was attracted to QS-orbits after the publications of NASA technical reports devoted to periodic moon orbits [3,4]. Moving in QS-orbit the SC remains permanently (or at least for long enough time) in the vicinity of small celestial body even in the case when the Hill sphere lies beneath the surface of the body. The properties of the QS-orbit can be studied using the averaging of the motion equations [5,6,7]. From the theoretical point of view it is a specific case of 1:1 mean motion resonance. The integrals of the averaged equations become the parameters defining the secular evolution of the QS-orbit. If the trajectory is robust enough to small perturbations in the simplified problem (i.e., restricted three body problem) it may correspond to long-term stability of the real-world orbit. Our investigations demonstrate that under the proper choice of the initial conditions the QS-orbits don’t escape from Moon or don’t impact Moon for long enough time. These orbits can be recommended as a convenient technique for the large

Retrogradation of Maize Starch after High Hydrostatic Pressure Gelation: Effect of Amylose Content and Depressurization Rate.

PubMed

Yang, Zhi; Swedlund, Peter; Gu, Qinfen; Hemar, Yacine; Chaieb, Sahraoui

2016-01-01

High hydrostatic pressure (HHP) has been employed to gelatinize or physically modify starch dispersions. In this study, waxy maize starch, normal maize starch, and two high amylose content starch were processed by a HHP of the order of 600 MPa, at 25°C for 15min. The effect of HHP processing on the crystallization of maize starches with various amylose content during storage at 4°C was investigated. Crystallization kinetics of HHP treated starch gels were investigated using rheology and FTIR. The effect of crystallization on the mechanical properties of starch gel network were evaluated in terms of dynamic complex modulus (G*). The crystallization induced increase of short-range helices structures were investigated using FTIR. The pressure releasing rate does not affect the starch retrogradation behaviour. The rate and extent of retrogradation depends on the amylose content of amylose starch. The least retrogradation was observed in HHP treated waxy maize starch. The rate of retrogradation is higher for HHP treated high amylose maize starch than that of normal maize starch. A linear relationship between the extent of retrogradation (phase distribution) measured by FTIR and G* is proposed.

Retrogradation of Maize Starch after High Hydrostatic Pressure Gelation: Effect of Amylose Content and Depressurization Rate

PubMed Central

Yang, Zhi; Swedlund, Peter; Gu, Qinfen; Hemar, Yacine; Chaieb, Sahraoui

2016-01-01

High hydrostatic pressure (HHP) has been employed to gelatinize or physically modify starch dispersions. In this study, waxy maize starch, normal maize starch, and two high amylose content starch were processed by a HHP of the order of 600 MPa, at 25°C for 15min. The effect of HHP processing on the crystallization of maize starches with various amylose content during storage at 4°C was investigated. Crystallization kinetics of HHP treated starch gels were investigated using rheology and FTIR. The effect of crystallization on the mechanical properties of starch gel network were evaluated in terms of dynamic complex modulus (G*). The crystallization induced increase of short-range helices structures were investigated using FTIR. The pressure releasing rate does not affect the starch retrogradation behaviour. The rate and extent of retrogradation depends on the amylose content of amylose starch. The least retrogradation was observed in HHP treated waxy maize starch. The rate of retrogradation is higher for HHP treated high amylose maize starch than that of normal maize starch. A linear relationship between the extent of retrogradation (phase distribution) measured by FTIR and G* is proposed. PMID:27219066

Retrograde recanalization of chronic total occlusions from the transradial approach; early Canadian experience.

PubMed

Rinfret, Stéphane; Joyal, Dominique; Nguyen, Can Manh; Bagur, Rodrigo; Hui, William; Leung, Raymond; Larose, Eric; Love, Michael P; Mansour, Samer

2011-09-01

Retrograde approach for chronic total occlusions (CTO) improves recanalization success rates. Eight French (Fr) catheters and the femoral approach are advocated. Evaluate whether transradial operators can achieve similar success rates using smaller catheters. This is a single-operator series of 42 consecutive cases performed between January and December 2010, including 13 while demonstrating CTO recanalization. Patients were referred because of complexity of the CTO or after failed attempt. Most frequent indications for recanalization were CCS 3-4 angina (52%) and CCS 1-2 in 21%. Eighteen (43%) patients underwent previous failed attempts. CTO was in the right coronary in 74%, left anterior descending in 24%, and a left main in 1. Most lesions (88%) were ≥20 mm long and 52% were calcified. We used septal collateral channels (CC) in 33 (79%), epicardial CC in 8 (20%), and a saphenous vein graft in one case. Radial access was used in all patients and was bilateral in 37 (88%). Five cases required one radial and one femoral access. Six French guides were used in 91% for the retrograde side and 71% for the antegrade side. Otherwise, 7 Fr guides were used. The Corsair(®) was used in 38 (90%). Procedural success was achieved in 37 (88%), mostly using reverse controlled antegrade-retrograde tracking (60%) or retrograde crossing (29%). The average <24-h Hb drop was 0.75 ± 0.84 g/dl. No in-hospital major cardiac events occurred. Transradial retrograde CTO recanalization is feasible, safe, and still associated with high success rates despite the use of smaller guide catheters. Copyright © 2011 Wiley-Liss, Inc.

Live-cell imaging of retrograde transport initiation in primary neurons.

PubMed

Nirschl, Jeffrey J; Holzbaur, Erika L F

2016-01-01

Axonal transport is an essential function in neurons, as mutations in either motor proteins or their adaptors cause neurodegeneration. While some mutations cause a complete block in axonal transport, other mutations affect transport more subtly. This is especially true of mutations identified in human patients, many of which impair but do not block motor function in the cell. Dissecting the pathogenic mechanisms of these more subtle mutations requires assays that can tease apart the distinct phases of axonal transport, including transport initiation, sustained/regulated motility, and cargo-specific sorting or delivery. Here, we describe a live-cell photobleaching assay to assess retrograde flux from the distal axon tip, a measure for distal transport initiation. We have previously used this method to show that the CAP-Gly domain of DCTN1 is required for efficient retrograde transport initiation in the distal axon, but it is not required to maintain retrograde flux along the mid-axon (Moughamian & Holzbaur, 2012). This approach has allowed us to examine the effects of disease-causing mutations in the axonal transport machinery, and in combination with other assays, will be useful in determining the mechanisms and regulation of axonal transport in normal and diseased conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Novel class of potential therapeutics that target ricin retrograde translocation.

PubMed

Redmann, Veronika; Gardner, Thomas; Lau, Zerlina; Morohashi, Keita; Felsenfeld, Dan; Tortorella, Domenico

2013-12-23

Ricin toxin, an A-B toxin from Ricinus communis, induces cell death through the inhibition of protein synthesis. The toxin binds to the cell surface via its B chain (RTB) followed by its retrograde trafficking through intracellular compartments to the ER where the A chain (RTA) is transported across the membrane and into the cytosol. Ricin A chain is transported across the ER membrane utilizing cellular proteins involved in the disposal of aberrant ER proteins by a process referred to as retrograde translocation. Given the current lack of therapeutics against ricin intoxication, we developed a high-content screen using an enzymatically attenuated RTA chimera engineered with a carboxy-terminal enhanced green fluorescent protein (RTA(E177Q)egfp) to identify compounds that target RTA retrograde translocation. Stabilizing RTA(E177Q)egfp through the inclusion of proteasome inhibitor produced fluorescent peri-nuclear granules. Quantitative analysis of the fluorescent granules provided the basis to discover compounds from a small chemical library (2080 compounds) with known bioactive properties. Strikingly, the screen found compounds that stabilized RTA molecules within the cell and several compounds limited the ability of wild type RTA to suppress protein synthesis. Collectively, a robust high-content screen was developed to discover novel compounds that stabilize intracellular ricin and limit ricin intoxication.

TCTEX1D2 mutations underlie Jeune asphyxiating thoracic dystrophy with impaired retrograde intraflagellar transport.

PubMed

Schmidts, Miriam; Hou, Yuqing; Cortés, Claudio R; Mans, Dorus A; Huber, Celine; Boldt, Karsten; Patel, Mitali; van Reeuwijk, Jeroen; Plaza, Jean-Marc; van Beersum, Sylvia E C; Yap, Zhi Min; Letteboer, Stef J F; Taylor, S Paige; Herridge, Warren; Johnson, Colin A; Scambler, Peter J; Ueffing, Marius; Kayserili, Hulya; Krakow, Deborah; King, Stephen M; Beales, Philip L; Al-Gazali, Lihadh; Wicking, Carol; Cormier-Daire, Valerie; Roepman, Ronald; Mitchison, Hannah M; Witman, George B

2015-06-05

The analysis of individuals with ciliary chondrodysplasias can shed light on sensitive mechanisms controlling ciliogenesis and cell signalling that are essential to embryonic development and survival. Here we identify TCTEX1D2 mutations causing Jeune asphyxiating thoracic dystrophy with partially penetrant inheritance. Loss of TCTEX1D2 impairs retrograde intraflagellar transport (IFT) in humans and the protist Chlamydomonas, accompanied by destabilization of the retrograde IFT dynein motor. We thus define TCTEX1D2 as an integral component of the evolutionarily conserved retrograde IFT machinery. In complex with several IFT dynein light chains, it is required for correct vertebrate skeletal formation but may be functionally redundant under certain conditions.

A New Navigation System of Renal Puncture for Endoscopic Combined Intrarenal Surgery: Real-time Virtual Sonography-guided Renal Access.

PubMed

Hamamoto, Shuzo; Unno, Rei; Taguchi, Kazumi; Ando, Ryosuke; Hamakawa, Takashi; Naiki, Taku; Okada, Shinsuke; Inoue, Takaaki; Okada, Atsushi; Kohri, Kenjiro; Yasui, Takahiro

2017-11-01

To evaluate the clinical utility of a new navigation technique for percutaneous renal puncture using real-time virtual sonography (RVS) during endoscopic combined intrarenal surgery. Thirty consecutive patients who underwent endoscopic combined intrarenal surgery for renal calculi, between April 2014 and July 2015, were divided into the RVS-guided puncture (RVS; n = 15) group and the ultrasonography-guided puncture (US; n = 15) group. In the RVS group, renal puncture was repeated until precise piercing of a papilla was achieved under direct endoscopic vision, using the RVS system to synchronize the real-time US image with the preoperative computed tomography image. In the US group, renal puncture was performed under US guidance only. In both groups, 2 urologists worked simultaneously to fragment the renal calculi after inserting the miniature percutaneous tract. The mean sizes of the renal calculi in the RVS and the US group were 33.5 and 30.5 mm, respectively. A lower mean number of puncture attempts until renal access through the calyx was needed for the RVS compared with the US group (1.6 vs 3.4 times, respectively; P = .001). The RVS group had a lower mean postoperative hemoglobin decrease (0.93 vs 1.39 g/dL, respectively; P = .04), but with no between-group differences with regard to operative time, tubeless rate, and stone-free rate. None of the patients in the RVS group experienced postoperative complications of a Clavien score ≥2, with 3 patients experiencing such complications in the US group. RVS-guided renal puncture was effective, with a lower incidence of bleeding-related complications compared with US-guided puncture. Copyright © 2017 Elsevier Inc. All rights reserved.

Apical/Retrograde Periimplantitis/Implant Periapical Lesion: Etiology, Risk Factors, and Treatment Options: A Systematic Review.

PubMed

Ramanauskaite, Ausra; Juodzbalys, Gintaras; Tözüm, Tolga F

2016-10-01

To review the literature on retrograde periimplantitis symptoms, risk factors, and treatment methods and to propose a decision-making tree of retrograde periimplantitis management. An electronic literature search was conducted on the MEDLINE and EMBASE databases for articles published between 1990 and 2015. Clinical human studies in the English language were included. The search resulted in 44 case reports published by 27 authors. The average time of the diagnosis of the pathology was found to be 26.07 weeks after implant placement (SD ± 39.7). Fistula formation was found to be the most common clinical symptom, statistically significantly more often occurring in the maxilla (P = 0.04). A negative correlation was found between pain and the adjacent tooth with incomplete endodontic treatment/endodontic pathology (r = -0.4; P = 0.009) and a positive correlation between the later risk factor and implant removal (r = 0.3; P = 0.028). Regenerative treatment (45.2% of the cases) or implant removal (35.7% of the cases) was the most common treatment techniques used. A decision-making tree of retrograde periimplantitis management is suggested. The etiology of retrograde periimplantitis is most often infectious. A decision-making tree aimed at managing patients with retrograde periimplantitis according to the possible etiology and symptoms of the disease can be a useful tool in the treatment of the pathology.

The planetary increase of brightness during retrograde motion: An explanandum constructed ad explanantem.

PubMed

Carman, Christián Carlos

2015-12-01

In Ancient Greek two models were proposed for explaining the planetary motion: the homocentric spheres of Eudoxus and the Epicycle and Deferent System. At least in a qualitative way, both models could explain the retrograde motion, the most challenging phenomenon to be explained using circular motions. Nevertheless, there is another explanandum: during retrograde motion the planets increase their brightness. It is natural to interpret a change of brightness, i.e., of apparent size, as a change in distance. Now, while according to the Eudoxian model the planet is always equidistant from the earth, according to the epicycle and deferent system, the planet changes its distance from the earth, approaching to it during retrograde motion, just as observed. So, it is usually affirmed that the main reason for the rejection of Eudoxus' homocentric spheres in favor of the epicycle and deferent system was that the first cannot explain the manifest planetary increase of brightness during retrograde motion, while the second can. In this paper I will show that this historical hypothesis is not as firmly founded as it is usually believed to be. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electroconvulsive therapy-induced persistent retrograde amnesia: could it be minimised by ketamine or other pharmacological approaches?

PubMed

Gregory-Roberts, Emily M; Naismith, Sharon L; Cullen, Karen M; Hickie, Ian B

2010-10-01

Certain pharmacological agents administered during electroconvulsive therapy may have the potential to prevent persistent retrograde amnesia induced during electroconvulsive therapy. This review examines mechanisms for electroconvulsive therapy-induced retrograde amnesia, and evaluates the suitability of the anaesthetic ketamine for preventing this amnestic outcome. A review of human studies, animal models and theoretical models in light of memory dysfunction following electroconvulsive therapy was conducted. MEDLINE was searched from 1950 to April 2009 using the MeSH terms "electroconvulsive therapy", "memory", "memory short term", "memory disorders", "excitatory amino acid antagonists", and "ketamine". PREMEDLINE was searched using the terms "electroconvulsive therapy", "amnesia" and "ketamine". Additional keyword and reference list searches were performed. No language, date constraints or article type constraints were used. Disruption of long term potentiation as a mechanism for electroconvulsive therapy-induced retrograde amnesia is well supported. Based on this putative mechanism, an N-methyl-D-aspartate receptor antagonist would appear suitable for preventing the retrograde amnesia. Available evidence in animals and humans supports the prediction that ketamine, an anaesthetic agent and N-methyl-D-aspartate receptor antagonist, could effectively prevent electroconvulsive therapy-induced persistent retrograde amnesia. Whilst there are concerns about the use of ketamine with electroconvulsive therapy, such as possible psychotomimetic effects, on balance this anaesthetic agent may improve or hasten clinical response to electroconvulsive therapy. A clinical trial is warranted to determine if ketamine anaesthesia during electroconvulsive therapy can lessen persistent retrograde amnesia and improve therapeutic response. Electroconvulsive therapy with ketamine anaesthesia may provide effective antidepressant action with minimal side effects. Copyright 2009 Elsevier B

Antibody-mediated inhibition of ricin toxin retrograde transport.

PubMed

Yermakova, Anastasiya; Klokk, Tove Irene; Cole, Richard; Sandvig, Kirsten; Mantis, Nicholas J

2014-04-08

Ricin is a member of the ubiquitous family of plant and bacterial AB toxins that gain entry into the cytosol of host cells through receptor-mediated endocytosis and retrograde traffic through the trans-Golgi network (TGN) and endoplasmic reticulum (ER). While a few ricin toxin-specific neutralizing monoclonal antibodies (MAbs) have been identified, the mechanisms by which these antibodies prevent toxin-induced cell death are largely unknown. Using immunofluorescence confocal microscopy and a TGN-specific sulfation assay, we demonstrate that 24B11, a MAb against ricin's binding subunit (RTB), associates with ricin in solution or when prebound to cell surfaces and then markedly enhances toxin uptake into host cells. Following endocytosis, however, toxin-antibody complexes failed to reach the TGN; instead, they were shunted to Rab7-positive late endosomes and LAMP-1-positive lysosomes. Monovalent 24B11 Fab fragments also interfered with toxin retrograde transport, indicating that neither cross-linking of membrane glycoproteins/glycolipids nor the recently identified intracellular Fc receptor is required to derail ricin en route to the TGN. Identification of the mechanism(s) by which antibodies like 24B11 neutralize ricin will advance our fundamental understanding of protein trafficking in mammalian cells and may lead to the discovery of new classes of toxin inhibitors and therapeutics for biodefense and emerging infectious diseases. IMPORTANCE Ricin is the prototypic member of the AB family of medically important plant and bacterial toxins that includes cholera and Shiga toxins. Ricin is also a category B biothreat agent. Despite ongoing efforts to develop vaccines and antibody-based therapeutics against ricin, very little is known about the mechanisms by which antibodies neutralize this toxin. In general, it is thought that antibodies simply prevent toxins from attaching to cell surface receptors or promote their clearance through Fc receptor (FcR)-mediated uptake

The first retrograde Trojan asteroid

NASA Astrophysics Data System (ADS)

Wiegert, Paul; Connors, Martin; Veillet, Christian

2018-04-01

There are about six thousand asteroids which share Jupiter's orbit around the Sun. Called the 'Trojan asteroids', they co-exist easily with this giant planet because they travel in the same direction as it ('direct' or 'prograde' motion), and remain roughly 60 degrees ahead of or behind it in its orbit. Newly discovered asteroid 2015 BZ509 is on a retrograde orbit, but is nonetheless in a state dynamically analogous to that of the prograde Trojans. The discovery circumstances and the nature of the motion of this curious asteroid -the first of its kind- will be outlined.

Reducing retrogradation and lipid oxidation of normal and glutinous rice flours by adding mango peel powder.

PubMed

Siriamornpun, Sirithon; Tangkhawanit, Ekkarat; Kaewseejan, Niwat

2016-06-15

Green and ripe mango peel powders (MPP) were added to normal rice flour (NRF) and glutinous rice flour (GRF) at three levels (400, 800 and 1200 ppm) and their effects on physicochemical properties and lipid oxidation inhibition were investigated. Overall, MPP increased the breakdown viscosity and reduced the final viscosity in rice flours when compared to the control. Decreasing in retrogradation was observed in both NRF and GRF with MPP added of all levels. MPP addition also significantly inhibited the lipid oxidation of all flours during storage (30 days). Retrogradation values were strongly negatively correlated with total phenolic and flavonoid contents, but not with fiber content. The hydrogen bonds and hydrophilic interactions between phenolic compounds with amylopectin molecule may be involved the decrease of starch retrogradation, especially GRF. We suggest that the addition of MPP not only reduced the retrogradation but also inhibited the lipid oxidation of rice flour. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Viral Receptor Complementation Strategy to Overcome CAV-2 Tropism for Efficient Retrograde Targeting of Neurons.

PubMed

Li, Shu-Jing; Vaughan, Alexander; Sturgill, James Fitzhugh; Kepecs, Adam

2018-06-06

Retrogradely transported neurotropic viruses enable genetic access to neurons based on their long-range projections and have become indispensable tools for linking neural connectivity with function. A major limitation of viral techniques is that they rely on cell-type-specific molecules for uptake and transport. Consequently, viruses fail to infect variable subsets of neurons depending on the complement of surface receptors expressed (viral tropism). We report a receptor complementation strategy to overcome this by potentiating neurons for the infection of the virus of interest-in this case, canine adenovirus type-2 (CAV-2). We designed AAV vectors for expressing the coxsackievirus and adenovirus receptor (CAR) throughout candidate projection neurons. CAR expression greatly increased retrograde-labeling rates, which we demonstrate for several long-range projections, including some resistant to other retrograde-labeling techniques. Our results demonstrate a receptor complementation strategy to abrogate endogenous viral tropism and thereby facilitate efficient retrograde targeting for functional analysis of neural circuits. Copyright © 2018 Elsevier Inc. All rights reserved.

A retrograde apoptotic signal originating in NGF-deprived distal axons of rat sympathetic neurons in compartmented cultures.

PubMed

Mok, Sue-Ann; Lund, Karen; Campenot, Robert B

2009-05-01

Previous investigations of retrograde survival signaling by nerve growth factor (NGF) and other neurotrophins have supported diverse mechanisms, but all proposed mechanisms have in common the generation of survival signals retrogradely transmitted to the neuronal cell bodies. We report the finding of a retrograde apoptotic signal in axons that is suppressed by local NGF signaling. NGF withdrawal from distal axons alone was sufficient to activate the pro-apoptotic transcription factor, c-jun, in the cell bodies. Providing NGF directly to cell bodies, thereby restoring a source of NGF-induced survival signals, could not prevent c-jun activation caused by NGF withdrawal from the distal axons. This is evidence that c-jun is not activated due to loss of survival signals at the cell bodies. Moreover, blocking axonal transport with colchicine inhibited c-jun activation caused by NGF deprivation suggesting that a retrogradely transported pro-apoptotic signal, rather than loss of a retrogradely transported survival signal, caused c-jun activation. Additional experiments showed that activation of c-jun, pro-caspase-3 cleavage, and apoptosis were blocked by the protein kinase C inhibitors, rottlerin and chelerythrine, only when applied to distal axons suggesting that they block the axon-specific pro-apoptotic signal. The rottlerin-sensitive mechanism was found to regulate glycogen synthase kinase 3 (GSK3) activity. The effect of siRNA knockdown, and pharmacological inhibition of GSK3 suggests that GSK3 is required for apoptosis caused by NGF deprivation and may function as a retrograde carrier of the axon apoptotic signal. The existence of a retrograde death signaling system in axons that is suppressed by neurotrophins has broad implications for neurodevelopment and for discovering treatments for neurodegenerative diseases and neurotrauma.

Acetylated adipate of retrograded starch as RS 3/4 type resistant starch.

PubMed

Kapelko-Żeberska, M; Zięba, T; Spychaj, R; Gryszkin, A

2015-12-01

This study was aimed at producing acetylated adipate of retrograded starch (ADA-R) with various degrees of substitution with functional groups and at determining the effect of esterification degree on resistance and pasting characteristics of the produced preparations. Paste was prepared from native potato starch, and afterwards frozen and defrosted. After drying and disintegration, the paste was acetylated and crosslinked using various doses of reagents. An increase in the total degree of esterification of the produced ADA-R-preparation caused an increase in its resistance to the action of amyloglucosidase. Viscosity of the paste produced from ADA-R-preparation in a wide range of acetylation degrees was increasing along with increasing crosslinking of starch. The study demonstrated that acetylated adipate of retrograded starch may be classified as a preparation of RS 3/4 type resistant starch (retrograded starch/chemically-modified starch) with good texture-forming properties. The conducted modification offers the possibility of modeling the level of resistance of the produced preparation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Neurovascular Structures at Risk With Curved Retrograde TTC Fusion Nails.

PubMed

de Cesar Netto, Cesar; Johannesmeyer, David; Cone, Brent; Araoye, Ibukunoluwa; Hudson, Parke William; Sahranavard, Bahman; Johnson, Michael; Shah, Ashish

2017-10-01

The purpose of this study was to assess the risk of iatrogenic injury to plantar neurovascular structures of the foot during insertion of a curved retrograde tibiotalocalcaneal (TTC) fusion nail. Ten below-knee thawed fresh-frozen cadaveric specimens underwent curved retrograde nailing of the ankle. The shortest distance between the nail and the main plantar neurovascular branches and injured structures were recorded during dissection. We also evaluated the relative position of these structures along 2 lines (AB, connecting the calcaneus to the first metatarsal, and BC, connecting the first and fifth metatarsal). The lateral plantar artery was found to be in direct contact with the nail 70% of the time, with a macroscopic laceration 30% of the time. The Baxter nerve was injured 20% of the time, as was the lateral plantar nerve. The medial plantar artery and nerve were never injured. The most proximal structure to cross line AB was the Baxter nerve followed by the lateral plantar artery, the nail, the lateral plantar nerve, and the medial plantar nerve. Our cadaveric anatomic study found that the most common structures at risk for iatrogenic injury by lateral curved retrograde TTC fusion nails were the lateral plantar artery and nerve, and the Baxter nerve. Determination of a true neurovascular safe zone is challenging and therefore warrants careful operative dissection to minimize neurovascular injuries.

Ileal Varices Treated with Balloon-Occluded Retrograde Transvenous Obliteration.

PubMed

Sato, Takahiro; Yamazaki, Katsu; Toyota, Jouji; Karino, Yoshiyasu; Ohmura, Takumi; Akaike, Jun

2009-04-01

A 55-year-old man with hepatitis B virus antigen-positive liver cirrhosis was admitted to our hospital with anal bleeding. Colonoscopy revealed blood retention in the entire colon, but no bleeding lesion was found. Computed tomography images showed that vessels in the ileum were connected to the right testicular vein, and we suspected ileal varices to be the most probable cause of bleeding. We immediately performed double balloon enteroscopy, but failed to find any site of bleeding owing to the difficulty of fiberscope insertion with sever adhesion. Using a balloon catheter during retrograde transvenous venography, we found ileal varices communicating with the right testicular vein (efferent vein) with the superior mesenteric vein branch as the afferent vein of these varices. We performed balloon occluded retrograde transvenous obliteration by way of the efferent vein of the varices and have detected no further bleeding in this patient one year after treatment.

Endoscopic retrograde cholangiopancreatography-associated AmpC Escherichia coli outbreak.

PubMed

Wendorf, Kristen A; Kay, Meagan; Baliga, Christopher; Weissman, Scott J; Gluck, Michael; Verma, Punam; D'Angeli, Marisa; Swoveland, Jennifer; Kang, Mi-Gyeong; Eckmann, Kaye; Ross, Andrew S; Duchin, Jeffrey

2015-06-01

We identified an outbreak of AmpC-producing Escherichia coli infections resistant to third-generation cephalosporins and carbapenems (CR) among 7 patients who had undergone endoscopic retrograde cholangiopancreatography at hospital A during November 2012-August 2013. Gene sequencing revealed a shared novel mutation in a bla CMY gene and a distinctive fumC/ fimH typing profile. To determine the extent and epidemiologic characteristics of the outbreak, identify potential sources of transmission, design and implement infection control measures, and determine the association between the CR E. coli and AmpC E. coli circulating at hospital A. We reviewed laboratory, medical, and endoscopy reports, and endoscope reprocessing procedures. We obtained cultures from endoscopes after reprocessing as well as environmental samples and conducted pulsed-field gel electrophoresis and gene sequencing on phenotypic AmpC isolates from patients and endoscopes. Cases were those infected with phenotypic AmpC isolates (both carbapenem-susceptible and CR) and identical bla CMY-2, fumC, and fimH alleles or related pulsed-field gel electrophoresis patterns. Thirty-five of 49 AmpC E. coli tested met the case definition, including all CR isolates. All cases had complicated biliary disease and had undergone at least 1 endoscopic retrograde cholangiopancreatography at hospital A. Mortality at 30 days was 16% for all patients and 56% for CR patients. Two of 8 reprocessed endoscopic retrograde cholangiopancreatography scopes harbored AmpC that matched case isolates by pulsed-field gel electrophoresis. Environmental cultures were negative. No breaches in infection control were identified. Endoscopic reprocessing exceeded manufacturer's recommended cleaning guidelines. Recommended reprocessing guidelines are not sufficient.

Routine Use of Surgical Retrograde Transtibial Endovascular Approach for Failed Attempts at Antegrade Recanalization of Chronic Peripheral Artery Total Occlusions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, GangZhu; Zhang, FuXian, E-mail: gangzhuliang@126.com; Luo, XiaoYun

PurposeOur aim was to describe the technical aspects and clinical outcomes of an open surgical approach to retrograde transtibial endovascular therapy for recanalization of chronic total occlusions (CTOs) of peripheral arteries because of inability to acquire antegrade intravascular access across the occlusion.Materials and MethodsBetween January 2011 and May 2014, conventional antegrade revascularization failed in 15 limbs of 15 patients (11 males, 4 females) with complex CTOs. The mean age of the patients was 74 years (range 48–83 years). Five patients had severe claudication (Rutherford Category 3), and 10 patients had critical limb-threatening ischemia (Rutherford Categories 4–5). For each of these cases ofmore » antegrade failure, an open surgical exposure of the tibial or dorsalis pedis artery was used to allow a safe retrograde transtibial endovascular approach to recanalize the CTO.ResultsSurgical retrograde access from the tibial artery was achieved successfully in 14 of the 15 patients. In the 14 successful retrograde endovascular approaches, surgical retrograde transtibial access was achieved from the dorsalis pedis artery in 8 patients and from the posterior tibial artery in 6. The average time to obtain retrograde access was 5 min (range 2–11 min). No stenosis or occlusion occurred in the tibial or dorsalis pedis arteries used for the retrograde access sites during follow-up.ConclusionsRoutine surgical exposure can be a safe and an effective method for retrograde transtibial access to the more proximal occluded arterial segments in selected patients with CTO.« less

Endoscopic retrograde cholangiopancreatography in patients with surgically altered anatomy

PubMed Central

Wang, Fei; Xu, Boming; Li, Quanpeng; Zhang, Xiuhua; Jiang, Guobing; Ge, Xianxiu; Nie, Junjie; Zhang, Xiuyun; Wu, Ping; Ji, Jie; Miao, Lin

2016-01-01

Abstract Endoscopic retrograde cholangiopancreatography (ERCP) in patients with surgically altered anatomy is challenging. Results of ERCP in those patients varied. The aim of our study was to evaluate the safety and effectiveness of various endoscopes-assisted ERCP in patients with surgically altered anatomy. Fifty-two patients with Billroth II reconstruction (group A), 20 patients with subtotal or total gastrectomy with Roux-en-Y anastomosis (group B), 25 patients with pancreatoduodenectomy or Roux-en-Y hepaticojejunostomy reconstruction (group C) were included. Gastroscope, duodenoscope, colonoscope, and double-balloon enteroscope were used. The endoscope insertion success rate of groups A, B, C was 96.2% (50/52), 85.0% (17/20), 80% (20/25), respectively. χ2 test showed that there was no significant difference between the 3 groups (P = 0.068). The mean insertion time was 36.7, 68.4, and 84.0 minutes, respectively. One-way ANOVA showed that the insertion time of group C was significantly longer than that of groups B and C (both P <0.001). The endoscopic cannulation success rates of groups A, B, C were 90%, 82.4%, and 100%, respectively. χ2 test showed that there was no significant difference between the 3 groups (P = 0.144). The mean cannulation time was 19.4, 28.1, and 20.4 minutes, respectively. One-way ANOVA showed that the cannulation time of group B was longer than that of groups A and C (P <0.001, P = 0.001, respectively). In total, 74 patients with successful biliary cannulation achieved the therapeutic goal; thus, the clinical success rate was 76.3% (74/97). Our study showed that ERCP in patients with surgically altered anatomy was safe and feasible. PMID:28033284

[RESEARCH PROGRESS IN COMPLICATIONS OF RETROGRADE INTRAMEDULLARY NAIL FIXATION FOR TIBIOTALOCALCANEAL ARTHRODESIS].

PubMed

Feng, Jun; Yu, Guangrong

2015-09-01

To review the cause, treatment, and prevention of complications of retrograde intramedullary nail fixation for tibiotalocalcaneal arthrodesis and enhance the recognition on the complications of tibiotalocalcaneal arthrodesis. The recent literature concerning intramedullary nail fixation for tibiotalocalcaneal arthrodesis was consulted and reviewed. There are intraoperative and postoperative complications of intramedullary nail fixation for tibiotalocalcaneal arthrodesis, and the causes, treatment, and prevention of complications are various. Progress of retrograde intramedullary nail fixation increases the successful rate of tibiotalocalcaneal arthrodesis. However, there is still a high complication rate, so strict preoperative assessment and skilled surgical technique are necessary to prevent complications.

JNK-Interacting Protein 3 Mediates the Retrograde Transport of Activated c-Jun N-Terminal Kinase and Lysosomes

PubMed Central

Drerup, Catherine M.; Nechiporuk, Alex V.

2013-01-01

Retrograde axonal transport requires an intricate interaction between the dynein motor and its cargo. What mediates this interaction is largely unknown. Using forward genetics and a novel in vivo imaging approach, we identified JNK-interacting protein 3 (Jip3) as a direct mediator of dynein-based retrograde transport of activated (phosphorylated) c-Jun N-terminal Kinase (JNK) and lysosomes. Zebrafish jip3 mutants (jip3nl7) displayed large axon terminal swellings that contained high levels of activated JNK and lysosomes, but not other retrograde cargos such as late endosomes and autophagosomes. Using in vivo analysis of axonal transport, we demonstrated that the terminal accumulations of activated JNK and lysosomes were due to a decreased frequency of retrograde movement of these cargos in jip3nl7, whereas anterograde transport was largely unaffected. Through rescue experiments with Jip3 engineered to lack the JNK binding domain and exogenous expression of constitutively active JNK, we further showed that loss of Jip3–JNK interaction underlies deficits in pJNK retrograde transport, which subsequently caused axon terminal swellings but not lysosome accumulation. Lysosome accumulation, rather, resulted from loss of lysosome association with dynein light intermediate chain (dynein accessory protein) in jip3nl7, as demonstrated by our co-transport analyses. Thus, our results demonstrate that Jip3 is necessary for the retrograde transport of two distinct cargos, active JNK and lysosomes. Furthermore, our data provide strong evidence that Jip3 in fact serves as an adapter protein linking these cargos to dynein. PMID:23468645

Ileal Varices Treated with Balloon-Occluded Retrograde Transvenous Obliteration

PubMed Central

Sato, Takahiro; Yamazaki, Katsu; Toyota, Jouji; Karino, Yoshiyasu; Ohmura, Takumi; Akaike, Jun

2009-01-01

A 55-year-old man with hepatitis B virus antigen-positive liver cirrhosis was admitted to our hospital with anal bleeding. Colonoscopy revealed blood retention in the entire colon, but no bleeding lesion was found. Computed tomography images showed that vessels in the ileum were connected to the right testicular vein, and we suspected ileal varices to be the most probable cause of bleeding. We immediately performed double balloon enteroscopy, but failed to find any site of bleeding owing to the difficulty of fiberscope insertion with sever adhesion. Using a balloon catheter during retrograde transvenous venography, we found ileal varices communicating with the right testicular vein (efferent vein) with the superior mesenteric vein branch as the afferent vein of these varices. We performed balloon occluded retrograde transvenous obliteration by way of the efferent vein of the varices and have detected no further bleeding in this patient one year after treatment. PMID:27956966

Continuous butanol fermentation and feed starch retrogradation: butanol fermentation sustainability using Clostridium beijerinckii BA101.

PubMed

Ezeji, T C; Qureshi, N; Blaschek, H P

2005-01-26

Use of starch solution as feed for butanol bioconversion processes employing Clostridium beijerinckii BA101 may have added economic advantage over the use of glucose. Acetone butanol ethanol (ABE) was produced from 30 gL(-1) starch solution using a continuous process. The bioreactor was fed at a dilution rate of 0.02 h(-1) and starch solution/feed volume (3 L) was replaced every 72 h. The continuous reactor fed with cornstarch solution (feed temperature 19 degrees C) produced approximately 6.0 gL(-1) total ABE. Increasing the feed storage temperature to 37 degrees C improved ABE production to 7.2 gL(-1) suggesting that retrogradation was occurring more rapidly at 19 degrees C. In both these cases the fermentation drifted toward acid production after approximately 260 h, consistent with the retrogradation of starch overtime. The use of soluble starch, which is less prone to retrogradation, resulted in the production of 9.9 gL(-1) ABE at 37 degrees C feed storage temperature, as compared to 7.2 gL(-1) ABE when cornstarch was used. It should be noted that gelatinized starch retrogradation takes place after sterilization and prior to use of the feed medium, and does not occur during long-term storage of the raw corn material in the months leading up to processing. The degree of hydrolysis of gelatinized starch decreased from 68.8 to 56.2% in 3 days when stored at 37 degrees C. Soluble starch which does not retrograde demonstrated no change in the degree of hydrolysis.

Contraction of the Ventral Abdomen Potentiates Extracardiac Retrograde Hemolymph Propulsion in the Mosquito Hemocoel

PubMed Central

Andereck, Jonathan W.; King, Jonas G.; Hillyer, Julián F.

2010-01-01

Background Hemolymph circulation in mosquitoes is primarily controlled by the contractile action of a dorsal vessel that runs underneath the dorsal midline and is subdivided into a thoracic aorta and an abdominal heart. Wave-like peristaltic contractions of the heart alternate in propelling hemolymph in anterograde and retrograde directions, where it empties into the hemocoel at the terminal ends of the insect. During our analyses of hemolymph propulsion in Anopheles gambiae, we observed periodic ventral abdominal contractions and hypothesized that they promote extracardiac hemolymph circulation in the abdominal hemocoel. Methodology/Principal Findings We devised methods to simultaneously analyze both heart and abdominal contractions, as well as to measure hemolymph flow in the abdominal hemocoel. Qualitative and quantitative analyses revealed that ventral abdominal contractions occur as series of bursts that propagate in the retrograde direction. Periods of ventral abdominal contraction begin only during periods of anterograde heart contraction and end immediately following a heartbeat directional reversal, suggesting that ventral abdominal contractions function to propel extracardiac hemolymph in the retrograde direction. To test this functional role, fluorescent microspheres were intrathoracically injected and their trajectory tracked throughout the hemocoel. Quantitative measurements of microsphere movement in extracardiac regions of the abdominal cavity showed that during periods of abdominal contractions hemolymph flows in dorsal and retrograde directions at a higher velocity and with greater acceleration than during periods of abdominal rest. Histochemical staining of the abdominal musculature then revealed that ventral abdominal contractions result from the contraction of intrasegmental lateral muscle fibers, intersegmental ventral muscle bands, and the ventral transverse muscles that form the ventral diaphragm. Conclusions/Significance These data show that

REVIVE Trial: Retrograde Delivery of Autologous Bone Marrow in Patients With Heart Failure.

PubMed

Patel, Amit N; Mittal, Sanjay; Turan, Goekmen; Winters, Amalia A; Henry, Timothy D; Ince, Hueseyin; Trehan, Naresh

2015-09-01

Cell therapy is an evolving option for patients with end-stage heart failure and ongoing symptoms despite optimal medical therapy. Our goal was to evaluate retrograde bone marrow cell delivery in patients with either ischemic heart failure (IHF) or nonischemic heart failure (NIHF). This was a prospective randomized, multicenter, open-label study of the safety and feasibility of bone marrow aspirate concentrate (BMAC) infused retrograde into the coronary sinus. Sixty patients were stratified by IHF and NIHF and randomized to receive either BMAC infusion or control (standard heart failure care) in a 4:1 ratio. Accordingly, 24 subjects were randomized to the ischemic BMAC group and 6 to the ischemic control group. Similarly, 24 subjects were randomized to the nonischemic BMAC group and 6 to the nonischemic control group. All 60 patients were successfully enrolled in the study. The treatment groups received BMAC infusion without complications. The left ventricular ejection fraction in the patients receiving BMAC demonstrated significant improvement compared with baseline, from 25.1% at screening to 31.1% at 12 months (p=.007) in the NIHF group and from 26.3% to 31.1% in the IHF group (p=.035). The end-systolic diameter decreased significantly in the nonischemic BMAC group from 55.6 to 50.9 mm (p=.020). Retrograde BMAC delivery is safe. All patients receiving BMAC experienced improvements in left ventricular ejection fraction, but only those with NIHF showed improvements in left ventricular end-systolic diameter and B-type natriuretic peptide. These results provide the basis for a larger clinical trial in HF patients. This work is the first prospective randomized clinical trial using high-dose cell therapy delivered via a retrograde coronary sinus infusion in patients with heart failure. This was a multinational, multicenter study, and it is novel, translatable, and scalable. On the basis of this trial and the safety of retrograde coronary sinus infusion, there are

Influence of chronic endurance exercise training on conduit artery retrograde and oscillatory shear in older adults.

PubMed

Casey, Darren P; Schneider, Aaron C; Ueda, Kenichi

2016-10-01

With aging, there tends to be an increase in retrograde and oscillatory shear in peripheral conduit arteries of humans. Whether the increase in shear rate is due to the aging process or an effect of a less active lifestyle that often accompanies aging is unknown. Therefore, we examined whether chronic endurance exercise training attenuates conduit artery retrograde and oscillatory shear in older adults. Brachial and common femoral artery mean blood velocities and diameter were determined via Doppler ultrasound under resting conditions, and shear rate was calculated in 13 young (24 ± 2 years), 17 older untrained (66 ± 3 years), and 16 older endurance exercise-trained adults (66 ± 7 years). Brachial artery retrograde (-9.1 ± 6.4 vs. -12.6 ± 9.4 s(-1); P = 0.35) and oscillatory (0.14 ± 0.08 vs. 0.14 ± 0.08 arbitrary units; P = 0.99) shear were similar between the older trained and untrained groups, whereas brachial artery retrograde and oscillatory shear were greater in older untrained compared to young adults (-5.0 ± 3.4, 0.08 ± 0.05 s(-1) arbitrary units, P = 0.017 and 0.048, respectively). There was no difference between the young and older trained brachial retrograde (P = 0.29) and oscillatory (P = 0.07) shear. Common femoral artery retrograde (-6.3 ± 2.9 s(-1)) and oscillatory (0.21 ± 0.08 arbitrary units) shear were reduced in older trained compared to the older untrained group (-10.4 ± 4.1 and 0.30 ± 0.09 s(-1) arbitrary units, both P = 0.005 and 0.006, respectively), yet similar to young adults (-7.1 ± 3.5 and 0.19 ± 0.06 s(-1) arbitrary units, P = 0.81 and 0.87, respectively). Our results suggest that chronic endurance exercise training in older adults ameliorates retrograde and oscillatory shear rate patterns, particularly in the common femoral artery.

Retrograde Accretion Discs in High-Mass Be/X-Ray Binaries

NASA Technical Reports Server (NTRS)

Christodoulou, D. M.; Laycock, S. G. T.; Kazanas, D.

2017-01-01

We have compiled a comprehensive library of all X-ray observations of Magellanic pulsars carried out by XMM-Newton, Chandra and RXTE in the period 1997-2014. In this work, we use the data from 53 high-mass Be/X-ray binaries in the Small Magellanic Cloud to demonstrate that the distribution of spin-period derivatives versus spin periods of spinning-down pulsars is not at all different from that of the accreting spinning-up pulsars. The inescapable conclusion is that the up and down samples were drawn from the same continuous parent population; therefore, Be/X-ray pulsars that are spinning down over periods spanning 18 yr are, in fact, accreting from retrograde discs. The presence of prograde and retrograde discs in roughly equal numbers supports a new evolutionary scenario for Be/X-ray pulsars in their spin period-period derivative diagram.

Balloon-Occluded Retrograde Transvenous Embolization of a Pelvic Arteriovenous Malformation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitsuzaki, Katsuhiko; Yamashita, Yasuyuki; Utsunomiya, Daisuke

1999-11-15

We successfully performed embolization therapy for a pelvic arteriovenous malformation by the retrograde transvenous approach using a liquid embolic material. This malformation was unique in that it had a single draining vein, which allowed this technique employing an occlusion balloon.

Endoscopic retrograde JJ-stenting of the ureter without fluoroscopy guidance--an appraisal of outcome.

PubMed

Shuaibu, S I; Gidado, S; Oseni-Momodu, E

2013-01-01

JJ- ureteral stenting is a means of relieving ureteric obstruction. It is done as a retrograde or antegrade procedure, usually under fluoroscopy guidance. We reviewed our results in 2 independent tertiary health centers in Nigeria which lack fluoroscopy units. A 2 year retrospective review of data of patients who had retrograde JJ- ureteric stenting was done. Data relating to age, indication and outcome of procedure were retrieved and analysed. 22 (71%) patients had successful retrograde JJ- ureteric stenting out of 31 patients who were taken for the procedure. These 22 patients had stenting of 27 ureteric units. Mean age was 48.5 years. Commonest indication was carcinoma of the cervix (31.8%). Commonest complication was irritative lower urinary tract symptoms (43.5%). In spite of inherent complications, JJ-stenting is a simple and safe technique. Therefore, the decision to attempt JJ -stenting in carefully selected patients in the absence of fluoroscopy is acceptable.

[Results of the percutaneous retrograde embolization as the first choice in the treatment of varicocele].

PubMed

Piñera, J Gonzálvez; Fernández-Córdoba, M S; Anselmi, E Hernández; Mollá, E Juliá; Jiménez, M J Pedrosa; Cabañero, A G Blanco; Baró, A Palma

2009-07-01

There is evidence that early varicocele treatment decreases testicular damage. The minimally invasive techniques such as laparoscopic varicocelectomy, antegrade sclerotherapy and percutaneous retrograde embolisation, are acquiring greater significance in the treatment of this disease. Since 1994, a series of 51 children, aged 7-16 years (mean, 12.9 years), with left-sided varicocele grades 2 (47%) and 3 (53%) were treated in our institution by percutaneous retrograde embolisation using coils. The right basilica vein was the most widely used (70%) followed by the right femoral vein. Seven children (13.7%) had complications: perforation of internal spermatic vein was the most frequent and treated conservatively. No child presented hydrocele after radiological procedures. Embolisation was accomplished succesfully at the first attempt in 35 (68.6%) of the 51 children and in 45 (88.2%) after a second embolisation. The follow-up ranges from 7 months to 5 ? years (mean, 1.8 years). The patients were monitored with clinical and doppler ultrasound examination 3, 6 and 12 months after the treatment. Retrograde embolisation is a safe and efficient minimally invasive treatment for correcting varicoceles in children. We performed retrograde embolisation as first choice of varicocele treatment in children; a second embolisation or conventional surgery for primary failure or late recurrence should be considered.

Structure of Waxy Maize Starch Hydrolyzed by Maltogenic α-Amylase in Relation to Its Retrogradation.

PubMed

Grewal, Navneet; Faubion, Jon; Feng, Guohua; Kaufman, Rhett C; Wilson, Jeff D; Shi, Yong-Cheng

2015-04-29

Maltogenic α-amylase is widely used as an antistaling agent in bakery foods. The objective of this study was to determine the degree of hydrolysis (DH) and starch structure after maltogenic amylase treatments in relation to its retrogradation. Waxy maize starch was cooked and hydrolyzed to different degrees by a maltogenic amylase. High-performance anion-exchange chromatography and size exclusion chromatography were used to determine saccharides formed and the molecular weight (Mw) distributions of the residual starch structure, respectively. Chain length (CL) distributions of debranched starch samples were further related to amylopectin (AP) retrogradation. Differential scanning calorimetry (DSC) results showed the complete inhibition of retrogradation when starches were hydrolyzed to >20% DH. Mw and CL distributions of residual AP structure indicated that with an increase in %DH, a higher proportion of unit chains with degree of polymerization (DP) ≤9 and a lower proportion of unit chains with DP ≥17 were formed. A higher proportion of short outer AP chains that cannot participate in the formation of double helices supports the decrease in and eventual inhibition of retrogradation observed with the increase in %DH. These results suggest that the maltogenic amylase could play a powerful role in inhibiting the staling of baked products even at limited starch hydrolysis.

Pseudotyped Lentiviral Vectors for Retrograde Gene Delivery into Target Brain Regions

PubMed Central

Kobayashi, Kenta; Inoue, Ken-ichi; Tanabe, Soshi; Kato, Shigeki; Takada, Masahiko; Kobayashi, Kazuto

2017-01-01

Gene transfer through retrograde axonal transport of viral vectors offers a substantial advantage for analyzing roles of specific neuronal pathways or cell types forming complex neural networks. This genetic approach may also be useful in gene therapy trials by enabling delivery of transgenes into a target brain region distant from the injection site of the vectors. Pseudotyping of a lentiviral vector based on human immunodeficiency virus type 1 (HIV-1) with various fusion envelope glycoproteins composed of different combinations of rabies virus glycoprotein (RV-G) and vesicular stomatitis virus glycoprotein (VSV-G) enhances the efficiency of retrograde gene transfer in both rodent and nonhuman primate brains. The most recently developed lentiviral vector is a pseudotype with fusion glycoprotein type E (FuG-E), which demonstrates highly efficient retrograde gene transfer in the brain. The FuG-E–pseudotyped vector permits powerful experimental strategies for more precisely investigating the mechanisms underlying various brain functions. It also contributes to the development of new gene therapy approaches for neurodegenerative disorders, such as Parkinson’s disease, by delivering genes required for survival and protection into specific neuronal populations. In this review article, we report the properties of the FuG-E–pseudotyped vector, and we describe the application of the vector to neural circuit analysis and the potential use of the FuG-E vector in gene therapy for Parkinson’s disease. PMID:28824385

Retrograde nailing for distal third femoral shaft fractures: a prospective study.

PubMed

Acharya, K N; Rao, M R

2006-12-01

To evaluate the postoperative knee function and results of unreamed retrograde nailing for distal third femoral shaft fractures. Between January 2002 and 2003 inclusive, a consecutive series of 27 patients (with 28 fractures) who underwent retrograde nailing were prospectively evaluated. Outcome measures were union time, initiation of weight bearing, deformity and shortening, functional length of the nail, knee function assessed using a modified Knee Society Knee Score. Correlations between union time and other variables were also studied. In these patients 26 (93%) of the 28 fractures achieved union, of which 5 underwent dynamisation; the mean union time for the other 21 fractures was 4.4 months. Angular malalignment was present in 4 patients and shortening in 4 others. There was negligible correlation between union time and variables of nail-canal diameter mismatch, functional length of nail, fracture geometry, or initiation of partial weight bearing ambulation. Knee flexion of more than 100 degrees was achieved in 26 patients. 19 patients had anterior knee pain and 10 had instability. By the end of one year, excellent or good scores for pain and function were recorded in 77% and 73% respectively, of the 26 patients. In view of such favourable union rates but significant deterioration in overall knee joint function, at best retrograde nailing is a reliable alternative in the management of selected complicated fractures of the distal femoral shaft.

Telescopic Corsair in 5F Guidion for Retrograde Recanalization of Complex Chronic Total Occlusions (CTOs).

PubMed

Palmers, Pieter-Jan; Maeremans, Joren; Meyer-Gessner, Markus; Bataille, Yoann; Dens, Joseph

2017-04-30

BACKGROUND Retrograde advancement of microcatheters through septal/epicardial connectors can be challenging. Although several tricks might help to do so (e.g., balloon trap of retro wire in second guiding, balloon trap of retro wire in native coronary artery, and use of antegrade extension to approximate the antegrade conduit to the retrograde gear), these tricks cannot always be applied, especially in patients with poor access. Also, puncturing, knuckling, and crossing of the distal CTO cap (or the aorta as described in 1 of the cases) sometimes needs a lot of backup of the microcatheter. CASE REPORT We describe 3 cases in which we used a novel telescopic technique with 5F Guidion (IMDS®) supported retrograde Corsair (Asahi®) advancement in complex CTO lesions. CONCLUSIONS The telescopic Corsair in 5F Guidion may offer the support needed to end successfully in these situations.

Improved techniques for double-balloon-enteroscopy-assisted endoscopic retrograde cholangiopancreatography

PubMed Central

Osoegawa, Takashi; Motomura, Yasuaki; Akahoshi, Kazuya; Higuchi, Naomi; Tanaka, Yoshimasa; Hisano, Terumasa; Itaba, Souichi; Gibo, Junya; Yamada, Mariko; Kubokawa, Masaru; Sumida, Yorinobu; Akiho, Hirotada; Ihara, Eikichi; Nakamura, Kazuhiko

2012-01-01

AIM: To investigate the clinical outcome of double balloon enteroscopy (DBE)-assisted endoscopic retrograde cholangiopancreatography (DB-ERCP) in patients with altered gastrointestinal anatomy. METHODS: Between September 2006 and April 2011, 47 procedures of DB-ERCP were performed in 28 patients with a Roux-en-Y total gastrectomy (n = 11), Billroth II gastrectomy (n = 15), or Roux-en-Y anastomosis with hepaticojejunostomy (n = 2). DB-ERCP was performed using a short-type DBE combined with several technical innovations such as using an endoscope attachment, marking by submucosal tattooing, selectively applying contrast medium, and CO2 insufflations. RESULTS: The papilla of Vater or hepaticojejunostomy site was reached in its entirety with a 96% success rate (45/47 procedures). There were no significant differences in the success rate of reaching the blind end with a DBE among Roux-en-Y total gastrectomy (96%), Billroth II reconstruction (94%), or pancreatoduodenectomy (100%), respectively (P = 0.91). The total successful rate of cannulation and contrast enhancement of the target bile duct in patients whom the blind end was reached with a DBE was 40/45 procedures (89%). Again, there were no significant differences in the success rate of cannulation and contrast enhancement of the target bile duct with a DBE among Roux-en-Y total gastrectomy (88 %), Billroth II reconstruction (89%), or pancreatoduodenectomy (100%), respectively (P = 0.67). Treatment was achieved in all 40 procedures (100%) in patients whom the contrast enhancement of the bile duct was successful. Common endoscopic treatments were endoscopic biliary drainage (24 procedures) and extraction of stones (14 procedures). Biliary drainage was done by placement of plastic stents. Stones extraction was done by lithotomy with the mechanical lithotripter followed by extraction with a basket or by the balloon pull-through method. Endoscopic sphincterotomy was performed in 14 procedures with a needle precutting

Stress, abdominal obesity and intrarenal resistive index in essential hypertension.

PubMed

Trovato, G M; Pace, P; Martines, G F; Trovato, F M; Pirri, C; Catalano, D

2012-07-01

Although it is commonly believed that a strong causal link exists between psychological stress and hypertension, as well with other factors, such as obesity, just what kind of empirical evidence supports this assumption is still controversial. The aim of the study is to investigate if perceived stress have any interference with intrarenal resistance and hence with mechanisms related to Essential Hypertension (EH) and if Anxiety, Depression, Self efficacy and Illness Perception can account for perceived stress. Obesity, insulin resistance (HOMA), Doppler Renal Resistive Index (RRI) and glomerular filtration rate (GFR) are studied along with Psychological Stress Measure (PSM), Illness Perception Questionnaire (IPQ-R), Generalized Self-Efficacy scale (GSE) and Hospital Anxiety and Depression Scale (HADS) in 119 hypertensive patients referred for stable lasting EH, and 150 normal controls. Lower salt/lower calories Mediterranean diet, physical activity increase and smoking withdrawal counseling were provided. By Odds Ratios, higher risk of EH is associated with greater perceived stress, older age, lower GFR, obesity, greater RRI and insulin resistance. By Multiple Linear Regression the most significant variable that accounts for higher RRI are abdominal obesity and arterial pulse pressure; the only significant independent psychological variable that accounts for abdominal obesity are PSM and identity IPQ subscale. Self-Efficacy anxiety and Illness perception subscales (IPQr), accounts significantly for 62.0% of the variance to PSM, with possible effects on RRI and on the pathophysiological hypertension cascade. Worst identity and treatment control perceptions of EH, and a lower self-efficacy are the main psychological factors accounting for a greater stress. Interventions aimed to reduce perceived stress can be warranted in EH.

Interventricular Septal Hematoma and Coronary-Ventricular Fistula: A Complication of Retrograde Chronic Total Occlusion Intervention

PubMed Central

Abdel-karim, Abdul-rahman R.; Main, Michael L.

2016-01-01

Interventricular septal hematoma is a rare complication of retrograde chronic total occlusion (CTO) percutaneous coronary interventions (PCI) with a typically benign course. Here we report two cases of interventricular septal hematoma and coronary-cameral fistula development after right coronary artery (RCA) CTO-PCI using a retrograde approach. Both were complicated by development of ST-segment elevation and chest pain. One case was managed actively and the other conservatively, both with a favorable outcome. PMID:27668097

Learning the Languages of the Chloroplast: Retrograde Signaling and Beyond.

PubMed

Chan, Kai Xun; Phua, Su Yin; Crisp, Peter; McQuinn, Ryan; Pogson, Barry J

2016-04-29

The chloroplast can act as an environmental sensor, communicating with the cell during biogenesis and operation to change the expression of thousands of proteins. This process, termed retrograde signaling, regulates expression in response to developmental cues and stresses that affect photosynthesis and yield. Recent advances have identified many signals and pathways-including carotenoid derivatives, isoprenes, phosphoadenosines, tetrapyrroles, and heme, together with reactive oxygen species and proteins-that build a communication network to regulate gene expression, RNA turnover, and splicing. However, retrograde signaling pathways have been viewed largely as a means of bilateral communication between organelles and nuclei, ignoring their potential to interact with hormone signaling and the cell as a whole to regulate plant form and function. Here, we discuss new findings on the processes by which organelle communication is initiated, transmitted, and perceived, not only to regulate chloroplastic processes but also to intersect with cellular signaling and alter physiological responses.

Retrograde spins of near-Earth asteroids from the Yarkovsky effect.

PubMed

La Spina, A; Paolicchi, P; Kryszczyńska, A; Pravec, P

2004-03-25

Dynamical resonances in the asteroid belt are the gateway for the production of near-Earth asteroids (NEAs). To generate the observed number of NEAs, however, requires the injection of many asteroids into those resonant regions. Collisional processes have long been claimed as a possible source, but difficulties with that idea have led to the suggestion that orbital drift arising from the Yarkovsky effect dominates the injection process. (The Yarkovsky effect is a force arising from differential heating-the 'afternoon' side of an asteroid is warmer than the 'morning' side.) The two models predict different rotational properties of NEAs: the usual collisional theories are consistent with a nearly isotropic distribution of rotation vectors, whereas the 'Yarkovsky model' predicts an excess of retrograde rotations. Here we report that the spin vectors of NEAs show a strong and statistically significant excess of retrograde rotations, quantitatively consistent with the theoretical expectations of the Yarkovsky model.

The epithelial cell cytoskeleton and intracellular trafficking. I. Shiga toxin B-subunit system: retrograde transport, intracellular vectorization, and more.

PubMed

Johannes, Ludger

2002-07-01

Many intracellular transport routes are still little explored. This is particularly true for retrograde transport between the plasma membrane and the endoplasmic reticulum. Shiga toxin B subunit has become a powerful tool to study this pathway, and recent advances on the molecular mechanisms of transport in the retrograde route and on its physiological function(s) are summarized. Furthermore, it is discussed how the study of retrograde transport of Shiga toxin B subunit allows one to design new methods for the intracellular delivery of therapeutic compounds.

Integrating bio-prosthetic valves in the Fontan operation - Novel treatment to control retrograde flow in caval veins

NASA Astrophysics Data System (ADS)

Vukicevic, Marija; Conover, Timothy; Zhou, Jian; Hsia, Tain-Yen; Figliola, Richard

2012-11-01

For a child born with only one functional heart ventricle, the sequence of palliative surgeries typically culminates in the Fontan operation. This procedure is usually successful initially, but leads to later complications, for reasons not fully understood. Examples are respiratory-dependent retrograde flows in the caval and hepatic veins, and increased pulmonary vascular resistance (PVR), hypothesized to be responsible for elevated pressure in the liver and disease of the liver and intestines. Here we study the parameters responsible for retrograde flows in the inferior vena cava (IVC) and hepatic vein (HV), and investigate two novel interventions to control retrograde flow: implanting either a Medtronic Contegra valved conduit or an Edwards lifescience pericardial aortic valve in the IVC or HV. We performed the experiments in a multi-scale, patient specific mock circuit, with normal and elevated PVR, towards the optimization of the Fontan circulation. The results show that both valves can significantly reduce retrograde flows in the veins, suggesting potential advantages in the treatment of the patients with congenital heart diseases. Fondation Leducq

DOD Needs to Improve Management and Oversight of Operations at the Theater Retrograde- Camp Arifjan, Kuwait

DTIC Science & Technology

2010-09-30

only at the TRC (includes Retro Sort), Warehouse, and Bulk Yard. 2 Theater Retrograde The Theater Retrograde consists of the TRC (includes Retro Sort...through Kuwait. Figure 1. Proper Flow of Materiel from Iraq through Kuwait Note 1: We reviewed operations at the TRC, Retro Sort, Warehouse...Materiel Processing Instructions CIIC Definition 1 Highest Sensitivity - Non-nuclear missiles and rockets , launcher tube and explosive rounds 2 Highest

Retrograde and anterograde memory following selective damage to the dorsolateral entorhinal cortex.

PubMed

Gervais, Nicole J; Barrett-Bernstein, Meagan; Sutherland, Robert J; Mumby, Dave G

2014-12-01

Anatomical and electrophysiological evidence suggest the dorsolateral entorhinal cortex (DLEC) is involved in processing spatial information, but there is currently no consensus on whether its functions are necessary for normal spatial learning and memory. The present study examined the effects of excitotoxic lesions of the DLEC on retrograde and anterograde memory on two tests of allocentric spatial learning: a hidden fixed-platform watermaze task, and a novelty-preference-based dry-maze test. Deficits were observed on both tests when training occurred prior to but not following n-methyl d-aspartate (NMDA) lesions of DLEC, suggesting retrograde memory impairment in the absence of anterograde impairments for the same information. The retrograde memory impairments were temporally-graded; rats that received DLEC lesions 1-3 days following training displayed deficits, while those that received lesions 7-10 days following training performed like a control group that received sham surgery. The deficits were not attenuated by co-infusion of tetrodotoxin, suggesting they are not due to disruption of neural processing in structures efferent to the DLEC, such as the hippocampus. The present findings provide evidence that the DLEC is involved in the consolidation of allocentric spatial information. Copyright © 2014 Elsevier Inc. All rights reserved.

Control of synaptic function by endocannabinoid-mediated retrograde signaling.

PubMed

Kano, Masanobu

2014-01-01

Since the first reports in 2001, great advances have been made towards the understanding of endocannabinoid-mediated synaptic modulation. Electrophysiological studies have revealed that one of the two major endocannabinoids, 2-arachidonoylglycerol (2-AG), is produced from membrane lipids upon postsynaptic Ca(2+) elevation and/or activation of Gq/11-coupled receptors, and released from postsynaptic neurons. The released 2-AG then acts retrogradely onto presynaptic cannabinoid CB1 receptors and induces suppression of neurotransmitter release either transiently or persistently. These forms of 2-AG-mediated retrograde synaptic modulation are functional throughout the brain. The other major endocannabinoid, anandamide, mediates a certain form of endocannabinoid-mediated long-term depression (LTD). Anandamide also functions as an agonist for transient receptor potential vanilloid receptor type 1 (TRPV1) and mediates endocannabinoid-independent and TRPV1-dependent forms of LTD. It has also been demonstrated that the endocannabinoid system itself is plastic, which can be either up- or down-regulated by experimental or environmental conditions. In this review, I will make an overview of the mechanisms underlying endocannabinoid-mediated synaptic modulation.

Control of synaptic function by endocannabinoid-mediated retrograde signaling

PubMed Central

KANO, Masanobu

2014-01-01

Since the first reports in 2001, great advances have been made towards the understanding of endocannabinoid-mediated synaptic modulation. Electrophysiological studies have revealed that one of the two major endocannabinoids, 2-arachidonoylglycerol (2-AG), is produced from membrane lipids upon postsynaptic Ca2+ elevation and/or activation of Gq/11-coupled receptors, and released from postsynaptic neurons. The released 2-AG then acts retrogradely onto presynaptic cannabinoid CB1 receptors and induces suppression of neurotransmitter release either transiently or persistently. These forms of 2-AG-mediated retrograde synaptic modulation are functional throughout the brain. The other major endocannabinoid, anandamide, mediates a certain form of endocannabinoid-mediated long-term depression (LTD). Anandamide also functions as an agonist for transient receptor potential vanilloid receptor type 1 (TRPV1) and mediates endocannabinoid-independent and TRPV1-dependent forms of LTD. It has also been demonstrated that the endocannabinoid system itself is plastic, which can be either up- or down-regulated by experimental or environmental conditions. In this review, I will make an overview of the mechanisms underlying endocannabinoid-mediated synaptic modulation. PMID:25169670

Retrograde ejaculation, painful ejaculation and hematospermia

PubMed Central

Parnham, Arie

2016-01-01

Although there has been an increased interest on premature ejaculation in the recent years, our understanding regarding the disorders of retrograde ejaculation, painful ejaculation and hematospermia remain limited. All three of these conditions require a keen clinical acumen and willingness to engage in thinking outside of the standard established treatment paradigm. The development of novel investigational techniques and treatments has led to progress in the management of these conditions symptoms; however, the literature almost uniformly is limited to small series and rare randomised trials. Further investigation and randomised controlled trials are needed for progress in these often challenging cases. PMID:27652230

Single- and double-balloon enteroscopy-assisted endoscopic retrograde cholangiopancreatography in patients with Roux-en-Y plus hepaticojejunostomy anastomosis and Whipple resection.

PubMed

Itokawa, Fumihide; Itoi, Takao; Ishii, Kentaro; Sofuni, Atsushi; Moriyasu, Fuminori

2014-04-01

In patients with Roux-en-Y hepaticojejunostomy (HJ with R-Y) and Whipple resection, endoscopic retrograde cholangiopancreatography (ERCP) can be challenging. We report our experience with ERCP using balloon-assisted enteroscopy (BAE) (BAE-ERCP) in patients with HJ with R-Y, and Whipple resection. BAE-ERCP procedures were carried out in 62 patients (HJ with R-Y:Whipple resection=34:28). Overall, the rates of reaching the anastomosis were 85.3% (29/34) in HJ with R-Y and 96.4% (27/28) in Whipple resection. In terms of HJ with R-Y, insertion success rate by standard single-balloon enteroscopy (SBE) was 89.3% (25/28). Insertion success rate by short BAE, including SBE and double-balloon enteroscopy (DBE), was 50% (3/6). There was a statistically significant difference of insertion success rate between standard long BE and short BE (P=0.021). However, in the Whipple patients, insertion success rate by standard and short SBE was 93.8% (15/16) and 91.7% (11/12), respectively. Initial insertion success rate by short BAE in Whipple patients was significantly higher than in HJ with R-Y (91.7% vs 50%, P=0.045). Therapeutic interventions included dilation of anastomosis stricture, stone extraction, endoscopic mechanical lithotripsy, biliary stent placement, stent extraction, endoscopic nasobiliary drainage, direct cholangioscopy, and electrohydraulic lithotripsy. Our HJ with R-Y series and Whipple series treatment success rate was 90% (18/20) and 95.0% (19/20), respectively. BAE-ERCP enabled ERCP to be carried out in patients with HJ. It is considered safe and feasible. Further experience and device improvement are needed. © 2014 The Authors. Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society.

A prospective, randomized, comparative clinical study of resin composite and glass ionomer cement for retrograde root filling.

PubMed

Jensen, S S; Nattestad, A; Egdø, P; Sewerin, I; Munksgaard, E C; Schou, S

2002-12-01

To compare the clinical and radiographic treatment outcome of retrograde root filling with either dentin-bonded resin composite (Retroplast, RP) or glass ionomer cement (Chelon-Silver, CS). A prospective, randomized clinical study of 134 consecutive patients with indication of retrograde root filling of an incisor, canine, premolar, or first molar. Either RP or CS was chosen at random as retrograde filling material. Either material was applied onto the entire resection surface after prepared slightly concave. This preparation technique makes a sealing of the entire resection surface possible and prevents marginal contraction gaps during polymerization. A total of 122 patients were available for 1-year follow-up. After 1 year the proportion of successful cases was significantly higher in the RP group (73%) than in the CS group (31%) (p<0.001). Doubtful healing with a need for a longer observation period was seen in 17% of the RP cases and 19% of the CS cases. The proportion of failures in the RP group (10%) was significantly lower than that in the CS group (50%) (p<0.001). Most of the unsuccessful CS cases failed due to loosening of the retrograde filling. Dentin-bonded RP applied onto the entire, slightly concave resection surface is a predictable apical sealant characterized by a high success rate. In contrast, retrograde root filling with CS results in an unacceptably high failure rate due to insufficient bonding strength to the concave resection surface.

Retrograde transfer RNA nuclear import provides a new level of tRNA quality control in Saccharomyces cerevisiae.

PubMed

Kramer, Emily B; Hopper, Anita K

2013-12-24

In eukaryotes, transfer RNAs (tRNAs) are transcribed in the nucleus yet function in the cytoplasm; thus, tRNA movement within the cell was believed to be unidirectional--from the nucleus to the cytoplasm. It is now known that mature tRNAs also move in a retrograde direction from the cytoplasm to the nucleus via retrograde tRNA nuclear import, a process that is conserved from yeast to vertebrates. The biological significance of this tRNA nuclear import is not entirely clear. We hypothesized that retrograde tRNA nuclear import might function in proofreading tRNAs to ensure that only proper tRNAs reside in the cytoplasm and interact with the translational machinery. Here we identify two major types of aberrant tRNAs in yeast: a 5', 3' end-extended, spliced tRNA and hypomodified tRNAs. We show that both types of aberrant tRNAs accumulate in mutant cells that are defective in tRNA nuclear traffic, suggesting that they are normally imported into the nucleus and are repaired or degraded. The retrograde pathway functions in parallel with the cytoplasmic rapid tRNA decay pathway previously demonstrated to monitor tRNA quality, and cells are not viable if they lack both pathways. Our data support the hypothesis that the retrograde process provides a newly discovered level of tRNA quality control as a pathway that monitors both end processing of pre-tRNAs and the modification state of mature tRNAs.

Retrograde transfer RNA nuclear import provides a new level of tRNA quality control in Saccharomyces cerevisiae

PubMed Central

Kramer, Emily B.; Hopper, Anita K.

2013-01-01

In eukaryotes, transfer RNAs (tRNAs) are transcribed in the nucleus yet function in the cytoplasm; thus, tRNA movement within the cell was believed to be unidirectional—from the nucleus to the cytoplasm. It is now known that mature tRNAs also move in a retrograde direction from the cytoplasm to the nucleus via retrograde tRNA nuclear import, a process that is conserved from yeast to vertebrates. The biological significance of this tRNA nuclear import is not entirely clear. We hypothesized that retrograde tRNA nuclear import might function in proofreading tRNAs to ensure that only proper tRNAs reside in the cytoplasm and interact with the translational machinery. Here we identify two major types of aberrant tRNAs in yeast: a 5′, 3′ end-extended, spliced tRNA and hypomodified tRNAs. We show that both types of aberrant tRNAs accumulate in mutant cells that are defective in tRNA nuclear traffic, suggesting that they are normally imported into the nucleus and are repaired or degraded. The retrograde pathway functions in parallel with the cytoplasmic rapid tRNA decay pathway previously demonstrated to monitor tRNA quality, and cells are not viable if they lack both pathways. Our data support the hypothesis that the retrograde process provides a newly discovered level of tRNA quality control as a pathway that monitors both end processing of pre-tRNAs and the modification state of mature tRNAs. PMID:24297920

Advances in Retrograde Technique for Coronary Chronic Total Occlusions

PubMed Central

DeMartini, Tony J.

2014-01-01

Despite a short lag period since its development the retrograde approach has been increasingly integrated within the treatment strategies for the percutaneous treatment of coronary chronic total occlusions. This review article discuss which anatomical features argue most powerfully for its use, the specific skills required for its uptake and the technology which has facilitated these developments. PMID:25311005

Numerical Simulations of Naturally Tilted, Retrogradely Precessing, Nodal Superhumping Accretion Disks

NASA Astrophysics Data System (ADS)

Montgomery, M. M.

2012-02-01

Accretion disks around black hole, neutron star, and white dwarf systems are thought to sometimes tilt, retrogradely precess, and produce hump-shaped modulations in light curves that have a period shorter than the orbital period. Although artificially rotating numerically simulated accretion disks out of the orbital plane and around the line of nodes generate these short-period superhumps and retrograde precession of the disk, no numerical code to date has been shown to produce a disk tilt naturally. In this work, we report the first naturally tilted disk in non-magnetic cataclysmic variables using three-dimensional smoothed particle hydrodynamics. Our simulations show that after many hundreds of orbital periods, the disk has tilted on its own and this disk tilt is without the aid of radiation sources or magnetic fields. As the system orbits, the accretion stream strikes the bright spot (which is on the rim of the tilted disk) and flows over and under the disk on different flow paths. These different flow paths suggest the lift force as a source to disk tilt. Our results confirm the disk shape, disk structure, and negative superhump period and support the source to disk tilt, source to retrograde precession, and location associated with X-ray and He II emission from the disk as suggested in previous works. Our results identify the fundamental negative superhump frequency as the indicator of disk tilt around the line of nodes.

[Tibio-talo-calcaneal arthrodesis with the retrograde intramedullary nail MEDIN].

PubMed

Popelka, S; Vavřík, P; Landor, I; Bek, J; Popelka ml, S; Hromádka, R

2013-01-01

When the talus and the talocalcaneal joint are both affected, their fusion is the method of treatment. Ankle arthrodesis is carried out using various osteosynthetic materials such as external fixators, screws and plates. One of the options is retrograde nailing. Tibio-talo-calcaneal arthrodesis is frequently indicated in patients with rheumatoid arthritis (RA) in whom both the talus and the subtalar joint are often affected. A retrograde nail for tibio-talo-calcaneal arthrodesis was developed at our department in cooperation with MEDIN Company. This is a titanium double-curved nail, with the distal part bent at 8 degrees ventrally and 10 degrees laterally. It is inserted from the transfibular approach. Sixty-two patients, 35 women and 27 men, were treated at our department from 2005. Since one patient had bilateral surgery, 63 ankles were included. The indications for arthrodesis involved rheumatoid arthritis in 42, post-traumatic arthritis in 10, failed ankle arthrodesis in two and failed total ankle arthroplasty in five ankles; tibial stress fractures close above the ankle in two RA patients, one patient with dermatomyositis and one with lupus erythematodes. The average age at the time of surgery was 64.2 years (range, 30 to 80). The average follow-up was 4.5 years (range, 1 to 9 years), Satisfaction with the treatment outcome and willingness to undergo surgery on the other side were reported by 82% of the patients. The AOFAS score improved from 35 to 74 points. Three (4.8%) patients complained of painful feet due to the fact that exact correction of the calcaneus was not achieved and the heel after arthrodesis remained in a slightly varus position. Of them, two had a failed total ankle arthroplasty. Post-operative complications included early infection managed by antibiotic treatment and early surgical revision with irrigation.in two (3.2%) RA patients, who were undergoing biological therapy. Late infection developed at 2 to 3 years after surgery in three (4

Rate of Subtalar Joint Arthrodesis After Retrograde Tibiotalocalcaneal Arthrodesis With Intramedullary Nail Fixation: Evaluation of the RAIN Database.

PubMed

Dujela, Michael; Hyer, Christopher F; Berlet, Gregory C

2017-11-01

Hindfoot arthritis or significant deformity involving the ankle and subtalar joint (STJ) is a disabling condition with few salvage options. Many surgeons note a decreased STJ fusion rate compared with ankle union when a retrograde nail construct is used. The purpose of this study was to report the STJ fusion rate of tibiotalocalcaneal (TTC) arthrodesis with retrograde nail. A chart and radiographic review was performed. TTC fusions performed in patients with osteoarthritis, posttraumatic arthritis, or deformity correction with retrograde nail fixation were included. Exclusion criteria included neuropathy, Charcot arthropathy, and failed total ankle replacement. Ultimately, 66 retrograde TTC fusions (in 63 patients) met inclusion criteria. The average age was 57.0 years. There were 29 female and 34 male patients. Radiographic fusion of the ankle and STJ was demonstrated in 68.2% of the patients. There were 11 cases (16.7%) of ankle arthrodesis with STJ nonunion, 6 cases (9.1%) of STJ fusion but ankle nonunion, and 4 cases (6.1%) of stable radiographic nonunion of both joints. The mean time to subtalar fusion was 112.1 days. One patient required revision surgery and conversion to below-knee amputation. One patient required a CROW walker for assistance with gait. A 22.8% radiographic nonunion rate of the STJ was noted in retrograde TTC fusion. Despite this, patients were stable and pain free. Level IV: Retrospective Case series.

The immune impact of mimic endoscopic retrograde appendicitis therapy and appendectomy on rabbits of acute appendicitis.

PubMed

Liu, Suqin; Pei, Fenghua; Wang, Xinhong; Li, Deliang; Zhao, Lixia; Song, Yanyan; Chen, Zhendong; Liu, Bingrong

2017-09-12

This study was conducted to evaluate the immune impact of mimic endoscopic retrograde appendicitis therapy and appendectomy on rabbits of acute suppurative appendicitis and to determine whether TLR4/MYD88/NF-κB signaling pathway was activated in this process. 48 rabbits were assigned into 4 groups: group I, the mimic endoscopic retrograde appendicitis therapy group; group II, the appendectomy group; group III, the model group; and group IV, the blank group. White blood cells decreased, while levels of C-reactive protein, tumor necrosis factor-α, interleukin-6, interleukin-4, and interleukin-10 increased on the 2 nd day in group I and II. IgA in feces decreased at 2 weeks, while fecal microbiota changed at 2 and 4 weeks after appendectomy. CD8 + cells in appendix of group I increased within 8 weeks. Upregulated expression of TLR4, MYD88, and nuclear NF-κB were detected on the 2 nd day in group I and II. Mimic endoscopic retrograde appendicitis therapy and appendectomy are effective ways for acute suppurative appendicitis. Mimic endoscopic retrograde appendicitis therapy was more preferable due to its advantage in maintaining intestinal immune function. TLR4/MYD88/NF-κB signaling pathway was activated in acute phase of appendicitis.

Evaluation of renal function in patients with a main renal stone larger than 1 cm and perioperative renal functional change in minimally invasive renal stone surgery: a prospective, observational study.

PubMed

Piao, Songzhe; Park, Juhyun; Son, Hwancheol; Jeong, Hyeon; Cho, Sung Yong

2016-05-01

To compare the perioperative relative renal function and determine predictors of deterioration and recovery of separate renal function in patients with renal stones >10 mm and who underwent mini-percutaneous nephrolithotomy or retrograde intra-renal surgery. A main stone >10 mm or stones growing, high-risk stone formers and extracorporeal shock-wave lithotripsy-resistant stones were prospectively included in 148 patients. Patients with bilateral renal stones and anatomical deformities were excluded. Renal function was evaluated by estimated glomerular filtration rate, 99m-technetium dimercaptosuccinic acid and 99m-technetium diethylenetriamine pentaacetate prior to intervention and at postoperative 3 months. Logistic regression analyses were performed to find predictors of functional deterioration and recovery. The overall stone-free rate was 85.1 %. A third of patients (53/148, 35.8 %) with renal stones >10 mm showed deterioration of separate renal function. Mean renal function of operative sites showed 58.2 % (36.8 %/63.2 %) of that of contralateral sites in these patients. Abnormal separate renal function showed postoperative recovery in 31 patients (58.5 %). Three cases (5.7 %) showed deterioration of separate renal function despite no presence of remnant stones. Improvement rates of the abnormal separate renal function did not differ according to the type of surgery. The presence of hydronephrosis and three or more stones were significant predictors for renal function deterioration. Female gender and three or more stones were significantly correlated with postoperative recovery. Mini-percutaneous nephrolithotomy or retrograde intra-renal surgery was effective and safe for renal function preservation. Patients with multiple large stones should be considered for candidates of active surgical removal.

Kinesin Khc-73/KIF13B modulates retrograde BMP signaling by influencing endosomal dynamics at the Drosophila neuromuscular junction

PubMed Central

Gray, Lindsay; Tsurudome, Kazuya; El-Mounzer, Wassim; Elazzouzi, Fatima; Baim, Christopher; Calderon, Mario R.; Kauwe, Grant

2018-01-01

Retrograde signaling is essential for neuronal growth, function and survival; however, we know little about how signaling endosomes might be directed from synaptic terminals onto retrograde axonal pathways. We have identified Khc-73, a plus-end directed microtubule motor protein, as a regulator of sorting of endosomes in Drosophila larval motor neurons. The number of synaptic boutons and the amount of neurotransmitter release at the Khc-73 mutant larval neuromuscular junction (NMJ) are normal, but we find a significant decrease in the number of presynaptic release sites. This defect in Khc-73 mutant larvae can be genetically enhanced by a partial genetic loss of Bone Morphogenic Protein (BMP) signaling or suppressed by activation of BMP signaling in motoneurons. Consistently, activation of BMP signaling that normally enhances the accumulation of phosphorylated form of BMP transcription factor Mad in the nuclei, can be suppressed by genetic removal of Khc-73. Using a number of assays including live imaging in larval motor neurons, we show that loss of Khc-73 curbs the ability of retrograde-bound endosomes to leave the synaptic area and join the retrograde axonal pathway. Our findings identify Khc-73 as a regulator of endosomal traffic at the synapse and modulator of retrograde BMP signaling in motoneurons. PMID:29373576

Rabies Virus Hijacks and Accelerates the p75NTR Retrograde Axonal Transport Machinery

PubMed Central

Gluska, Shani; Zahavi, Eitan Erez; Chein, Michael; Gradus, Tal; Bauer, Anja; Finke, Stefan; Perlson, Eran

2014-01-01

Rabies virus (RABV) is a neurotropic virus that depends on long distance axonal transport in order to reach the central nervous system (CNS). The strategy RABV uses to hijack the cellular transport machinery is still not clear. It is thought that RABV interacts with membrane receptors in order to internalize and exploit the endosomal trafficking pathway, yet this has never been demonstrated directly. The p75 Nerve Growth Factor (NGF) receptor (p75NTR) binds RABV Glycoprotein (RABV-G) with high affinity. However, as p75NTR is not essential for RABV infection, the specific role of this interaction remains in question. Here we used live cell imaging to track RABV entry at nerve terminals and studied its retrograde transport along the axon with and without the p75NTR receptor. First, we found that NGF, an endogenous p75NTR ligand, and RABV, are localized in corresponding domains along nerve tips. RABV and NGF were internalized at similar time frames, suggesting comparable entry machineries. Next, we demonstrated that RABV could internalize together with p75NTR. Characterizing RABV retrograde movement along the axon, we showed the virus is transported in acidic compartments, mostly with p75NTR. Interestingly, RABV is transported faster than NGF, suggesting that RABV not only hijacks the transport machinery but can also manipulate it. Co-transport of RABV and NGF identified two modes of transport, slow and fast, that may represent a differential control of the trafficking machinery by RABV. Finally, we determined that p75NTR-dependent transport of RABV is faster and more directed than p75NTR-independent RABV transport. This fast route to the neuronal cell body is characterized by both an increase in instantaneous velocities and fewer, shorter stops en route. Hence, RABV may employ p75NTR-dependent transport as a fast mechanism to facilitate movement to the CNS. PMID:25165859

Acute inhibition of diacylglycerol lipase blocks endocannabinoid-mediated retrograde signalling: evidence for on-demand biosynthesis of 2-arachidonoylglycerol

PubMed Central

Hashimotodani, Yuki; Ohno-Shosaku, Takako; Tanimura, Asami; Kita, Yoshihiro; Sano, Yoshikazu; Shimizu, Takao; Di Marzo, Vincenzo; Kano, Masanobu

2013-01-01

The endocannabinoid (eCB) 2-arachidonoylglycerol (2-AG) produced by diacylglycerol lipase α (DGLα) is one of the best-characterized retrograde messengers at central synapses. It has been thought that 2-AG is produced ‘on demand’ upon activation of postsynaptic neurons. However, recent studies propose that 2-AG is pre-synthesized by DGLα and stored in neurons, and that 2-AG is released from such ‘pre-formed pools’ without the participation of DGLα. To address whether the 2-AG source for retrograde signalling is the on-demand biosynthesis by DGLα or the mobilization from pre-formed pools, we examined the effects of acute pharmacological inhibition of DGL by a novel potent DGL inhibitor, OMDM-188, on retrograde eCB signalling triggered by Ca2+ elevation, Gq/11 protein-coupled receptor activation or synergy of these two stimuli in postsynaptic neurons. We found that pretreatment for 1 h with OMDM-188 effectively blocked depolarization-induced suppression of inhibition (DSI), a purely Ca2+-dependent form of eCB signalling, in slices from the hippocampus, striatum and cerebellum. We also found that at parallel fibre–Purkinje cell synapses in the cerebellum OMDM-188 abolished synaptically induced retrograde eCB signalling, which is known to be caused by the synergy of postsynaptic Ca2+ elevation and group I metabotropic glutamate receptor (I-mGluR) activation. Moreover, brief OMDM-188 treatments for several minutes were sufficient to suppress both DSI and the I-mGluR-induced retrograde eCB signalling in cultured hippocampal neurons. These results are consistent with the hypothesis that 2-AG for synaptic retrograde signalling is supplied as a result of on-demand biosynthesis by DGLα rather than mobilization from presumptive pre-formed pools. PMID:23858009

The postsynaptic t-SNARE Syntaxin 4 controls traffic of Neuroligin 1 and Synaptotagmin 4 to regulate retrograde signaling.

PubMed

Harris, Kathryn P; Zhang, Yao V; Piccioli, Zachary D; Perrimon, Norbert; Littleton, J Troy

2016-05-25

Postsynaptic cells can induce synaptic plasticity through the release of activity-dependent retrograde signals. We previously described a Ca(2+)-dependent retrograde signaling pathway mediated by postsynaptic Synaptotagmin 4 (Syt4). To identify proteins involved in postsynaptic exocytosis, we conducted a screen for candidates that disrupted trafficking of a pHluorin-tagged Syt4 at Drosophila neuromuscular junctions (NMJs). Here we characterize one candidate, the postsynaptic t-SNARE Syntaxin 4 (Syx4). Analysis of Syx4 mutants reveals that Syx4 mediates retrograde signaling, modulating the membrane levels of Syt4 and the transsynaptic adhesion protein Neuroligin 1 (Nlg1). Syx4-dependent trafficking regulates synaptic development, including controlling synaptic bouton number and the ability to bud new varicosities in response to acute neuronal stimulation. Genetic interaction experiments demonstrate Syx4, Syt4, and Nlg1 regulate synaptic growth and plasticity through both shared and parallel signaling pathways. Our findings suggest a conserved postsynaptic SNARE machinery controls multiple aspects of retrograde signaling and cargo trafficking within the postsynaptic compartment.

Subclavian steal: Endovascular treatment of total occlusions of the subclavian artery using a retrograde transradial subintimal approach

PubMed Central

Golwala, Sohil N; Vance, Ansar Z; Tuerff, Sonya N

2016-01-01

Introduction In symptomatic subclavian steal syndrome, endovascular treatment is the first line of therapy prior to extra-anatomic surgical bypass procedures. Subintimal recanalization has been well described in the literature for the coronary arteries, and more recently, in the lower extremities. By modifying this approach, we present a unique retrograde technique using a heavy tip microwire to perform controlled subintimal dissection. Methods We present two cases of symptomatic subclavian steal related to chronic total occlusion of the left subclavian artery and right innominate artery, respectively. Standard crossing techniques were unsuccessful. Commonly at this point, the procedures would be aborted and open surgical intervention would have to be pursued. In our cases, retrograde access was easily achieved via an ipsilateral retrograde radial artery, using controlled subintimal dissection and a heavy-tipped wire. Results We were able to easily achieve recanalization in both attempted cases of chronic total occlusion of the subclavian and innominate artery, using a retrograde radial subintimal approach. Subsequent stent-supported angioplasty resulted in complete revascularization. No major complications were encountered during the procedures; however, one patient did develop thromboembolic stroke secondary to platelet aggregation to the stent graft, 9 days post-procedure. Conclusions Endovascular treatment is considered the first-line intervention in medically refractory patients with symptomatic subclavian steal syndrome. In the setting of chronic total occlusions, a retrograde radial subintimal approach using a heavy tip wire for controlled subintimal dissection is a novel technique that may be considered when standard approaches and wires have failed. PMID:26861024

Retrograde and Wallerian Axonal Degeneration Occur Synchronously after Retinal Ganglion Cell Axotomy

PubMed Central

Kanamori, Akiyasu; Catrinescu, Maria-Magdalena; Belisle, Jonathan M.; Costantino, Santiago; Levin, Leonard A.

2013-01-01

Axonal injury and degeneration are pivotal pathological events in diseases of the nervous system. In the past decade, it has been recognized that the process of axonal degeneration is distinct from somal degeneration and that axoprotective strategies may be distinct from those that protect the soma. Preserving the cell body via neuroprotection cannot improve function if the axon is damaged, because the soma is still disconnected from its target. Therefore, understanding the mechanisms of axonal degeneration is critical for developing new therapeutic interventions for axonal disease treatment. We combined in vivo imaging with a multilaser confocal scanning laser ophthalmoscope and in vivo axotomy with a diode-pumped solid-state laser to assess the time course of Wallerian and retrograde degeneration of unmyelinated retinal ganglion cell axons in living rats for 4 weeks after intraretinal axotomy. Laser injury resulted in reproducible axon loss both distal and proximal to the site of injury. Longitudinal polarization-sensitive imaging of axons demonstrated that Wallerian and retrograde degeneration occurred synchronously. Neurofilament immunostaining of retinal whole-mounts confirmed axonal loss and demonstrated sparing of adjacent axons to the axotomy site. In vivo fluorescent imaging of axonal transport and photobleaching of labeled axons demonstrated that the laser axotomy model did not affect adjacent axon function. These results are consistent with a shared mechanism for Wallerian and retrograde degeneration. PMID:22642911

Comparison Between Retrograde and Antegrade Peripheral Venous Cannulation in Intensive Care Unit Patients: Assessment of Thrombus Formation.

PubMed

Abdelaal Ahmed Mahmoud, Ahmed; El-Shafei, Hassan Ismail; Yassin, Hany Mahmoud; Elramely, Mohamed Adly; Abdelhaq, Mohamed Mohamed; El Kady, Hany Wafiq; Awada, Wael Nabil Fahemy

2017-06-01

Antegrade cannulation of peripheral veins is the usual practice. Blood stasis between a catheter and the wall of the vein or at its tip in addition to catheter-induced phlebitis may initiate a thrombosis. The use of retrograde ventriculojugular shunts against the direction of the blood flow with resultant decrease in the incidence of venous thrombosis encouraged us to compare retrograde versus conventional antegrade peripheral venous cannulation. Monocentric, nonblinded, prospective observational cohort of 40 intensive care unit patients receiving 2 peripheral venous catheters in upper limbs, 1 inserted in the direction of blood flow (antegrade cannula) and the other inserted in an opposite direction to blood flow (retrograde cannula). Daily ultrasound assessment of the angle between the catheter and the vascular wall was done to detect onset and progression of thrombus formation. The study included 40 patients, aged 46.7 ± 10.132 years. The incidence of thrombus formation was 100% in both techniques. The onset time of thrombus formation between the catheter and the wall of a vein was significantly longer with the retrograde catheters than with the antegrade catheters with median time (interquartile range [range]) 6 days (5-6.75 [4-8]) with 95% confidence interval (CI), 5.58-6.42 vs 3 days (3-4 [2-5]) with 95% CI (2.76-3.24), respectively, with a P value <.001. The time needed by the recently detected thrombus to reach the catheter tip determined by ultrasound with or without catheter failure was significantly longer in the retrograde catheters than in the antegrade catheter with median time (interquartile range [range]) 9 days (8-9 [7-10]) with 95% CI, 8.76-9.24 vs 4 days (4-5 [3-6]) with 95% CI, 3.76-4.24, respectively, with a P value <.001. Retrograde cannulation did not decrease the incidence of thrombus formation, but significantly increased the onset time until thrombus formation and prolonged the time needed by the newly formed thrombus to reach the

Chronic total occlusion in ostium of right coronary artery – retrograde approach as the first-choice method of revascularization?

PubMed Central

Kameczura, Tomasz; Surowiec, Sławomir; Januś, Bogdan; Derlaga, Bogusław; Dudek, Dariusz; Czarnecka, Danuta

2013-01-01

Recanalization of chronic total occlusion (CTO) located in the ostium may require the operator's ability to use the retrograde approach. We present a case of opening a chronically occluded right coronary artery (RCA) by the retrograde approach after an unsuccessful attempt of recanalization by classic antegrade technique. PMID:24570749

Retrograde endopyelotomy: a comparison between laser and Acucise balloon cutting catheter.

PubMed

el-Nahas, Ahmed R

2007-03-01

Endopyelotomy and laparoscopic pyeloplasty are the preferred modalities for treatment of ureteropelvic junction obstruction because of their minimally invasive nature. There are continuous efforts for improving endopyelotomy techniques and outcome. Retrograde access represents the natural evolution of endopyelotomy. The Acucise cutting balloon catheter (Applied Medical Resources Corp., Laguna Hills, CA) and ureteroscopic endopyelotomy using holmium laser are the most widely accepted techniques. The Acucise catheter was developed to simplify retrograde endopyelotomy and made it possible for all urologists, regardless of their endourologic skills. The Acucise catheter depends on incision and dilatation of the ureteropelvic junction under fluoroscopic guidance, whereas ureteroscopy allows visual control of the site, depth, and extent of the incision; the holmium laser is a perfect method for a clean precise incision. Review of the English literature showed that the Acucise technique was more widely performed, though laser had better (but not statistically significant) safety and efficacy profiles.

The microRNA miR-1 regulates a MEF-2 dependent retrograde signal at neuromuscular junctions

PubMed Central

Simon, David J.; Madison, Jon M.; Conery, Annie L.; Thompson-Peer, Katherine L.; Soskis, Michael; Ruvkun, Gary B.; Kaplan, Joshua M.; Kim, John K.

2008-01-01

Summary We show that miR-1, a conserved muscle specific microRNA, regulates aspects of both pre- and post-synaptic function at C. elegans neuromuscular junctions. miR-1 regulates the expression level of two nicotinic acetylcholine receptor (nAChR) subunits (UNC-29 and UNC-63), thereby altering muscle sensitivity to acetylcholine (ACh). miR-1 also regulates the muscle transcription factor MEF-2, which results in altered pre-synaptic ACh secretion, suggesting that MEF-2 activity in muscles controls a retrograde signal. The effect of the MEF-2-dependent retrograde signal on secretion is mediated by the synaptic vesicle protein RAB-3. Finally, acute activation of levamisole-sensitive nAChRs stimulates MEF-2-dependent transcriptional responses, and induces the MEF-2-dependent retrograde signal. We propose that miR-1 refines synaptic function by coupling changes in muscle activity to changes in pre-synaptic function. PMID:18510933

Isoflurane causes anterograde but not retrograde amnesia for pavlovian fear conditioning.

PubMed

Dutton, Robert C; Maurer, Anya J; Sonner, James M; Fanselow, Michael S; Laster, Michael J; Eger, Edmond I

2002-05-01

Production of retrograde amnesia by anesthetics would indicate that these drugs can disrupt mechanisms that stabilize memory. Such disruption would allow suppression of memory of previous untoward events. The authors examined whether isoflurane provides retrograde amnesia for classic (Pavlovian) fear conditioning. Rats were trained to fear tone by applying three (three-trial) or one (one-trial) tone-shock pairs while breathing various constant concentrations of isoflurane. Immediately after training, isoflurane administration was either discontinued, maintained unchanged, or rapidly increased to 1.0 minimum alveolar concentration for 1 h longer. Groups of rats were similarly trained to fear context while breathing isoflurane by applying shocks (without tones) in a distinctive environment. The next day, memory for the conditioned stimuli was determined by presenting the tone or context (without shock) and measuring the proportion of time each rat froze (appeared immobile). For each conditioning procedure, the effects of the three posttraining isoflurane treatments were compared. Rapid increases in posttraining isoflurane administration did not suppress conditioned fear for any of the training procedures. In contrast, isoflurane administration during conditioning dose-dependently suppressed conditioning (P < 0.05). Training to tone was more resistant to the effects of isoflurane than training to context (P < 0.05), and the three-trial learning procedure was more was more resistant than the one-trial procedure (P < 0.05). Isoflurane provided intense dose-dependent anterograde but not retrograde amnesia for classic fear conditioning. Isoflurane appears to disrupt memory processes that occur at or within a few minutes of the conditioning procedure.

The pUL37 tegument protein guides alpha-herpesvirus retrograde axonal transport to promote neuroinvasion

PubMed Central

Richards, Alexsia L.; Sollars, Patricia J.; Stults, Austin M.; Pickard, Gary E.

2017-01-01

A hallmark property of the neurotropic alpha-herpesvirinae is the dissemination of infection to sensory and autonomic ganglia of the peripheral nervous system following an initial exposure at mucosal surfaces. The peripheral ganglia serve as the latent virus reservoir and the source of recurrent infections such as cold sores (herpes simplex virus type I) and shingles (varicella zoster virus). However, the means by which these viruses routinely invade the nervous system is not fully understood. We report that an internal virion component, the pUL37 tegument protein, has a surface region that is an essential neuroinvasion effector. Mutation of this region rendered herpes simplex virus type 1 (HSV-1) and pseudorabies virus (PRV) incapable of spreading by retrograde axonal transport to peripheral ganglia both in culture and animals. By monitoring the axonal transport of individual viral particles by time-lapse fluorescence microscopy, the mutant viruses were determined to lack the characteristic sustained intracellular capsid motion along microtubules that normally traffics capsids to the neural soma. Consistent with the axonal transport deficit, the mutant viruses did not reach sites of latency in peripheral ganglia, and were avirulent. Despite this, viral propagation in peripheral tissues and in cultured epithelial cell lines remained robust. Selective elimination of retrograde delivery to the nervous system has long been sought after as a means to develop vaccines against these ubiquitous, and sometimes devastating viruses. In support of this potential, we find that HSV-1 and PRV mutated in the effector region of pUL37 evoked effective vaccination against subsequent nervous system challenges and encephalitic disease. These findings demonstrate that retrograde axonal transport of the herpesviruses occurs by a virus-directed mechanism that operates by coordinating opposing microtubule motors to favor sustained retrograde delivery of the virus to the peripheral ganglia

The role of the dynein light intermediate chain in retrograde IFT and flagellar function in Chlamydomonas

PubMed Central

Reck, Jaimee; Schauer, Alexandria M.; VanderWaal Mills, Kristyn; Bower, Raqual; Tritschler, Douglas; Perrone, Catherine A.; Porter, Mary E.

2016-01-01

The assembly of cilia and flagella depends on the activity of two microtubule motor complexes, kinesin-2 and dynein-2/1b, but the specific functions of the different subunits are poorly defined. Here we analyze Chlamydomonas strains expressing different amounts of the dynein 1b light intermediate chain (D1bLIC). Disruption of D1bLIC alters the stability of the dynein 1b complex and reduces both the frequency and velocity of retrograde intraflagellar transport (IFT), but it does not eliminate retrograde IFT. Flagellar assembly, motility, gliding, and mating are altered in a dose-dependent manner. iTRAQ-based proteomics identifies a small subset of proteins that are significantly reduced or elevated in d1blic flagella. Transformation with D1bLIC-GFP rescues the mutant phenotypes, and D1bLIC-GFP assembles into the dynein 1b complex at wild-type levels. D1bLIC-GFP is transported with anterograde IFT particles to the flagellar tip, dissociates into smaller particles, and begins processive retrograde IFT in <2 s. These studies demonstrate the role of D1bLIC in facilitating the recycling of IFT subunits and other proteins, identify new components potentially involved in the regulation of IFT, flagellar assembly, and flagellar signaling, and provide insight into the role of D1bLIC and retrograde IFT in other organisms. PMID:27251063

[Tibiocalcaneal arthrodesis using retrograde insertion of a compression nail].

PubMed

Bölderl, A; Dallapozza, C; Wille, M

2011-12-01

OPERATION GOAL: Arthrodesis of the upper and lower ankle joint because of problematic bone positioning or failed arthrodesis. Osteosynthesis procedure using a retrograde compression nail. To achieve stable, fully weight-bearing osteosynthesis for early, pain-free mobilization. Rearthrodesis because of failure of the conventional arthrodesis technique and development of osteoarthritis of the lower ankle joint. Painful osteoarthritis of the upper ankle joint because of inadequate perfusion or a major bone defect because of sclerosis or necrosis. Primary arthrodesis because of facture of the lower leg (pilon tibial) with joint involvement and preexisting osteoarthritis. Acute osteitis/osteomyelitis, sclerosis in the marrow of the distal tibia, malalignment of the distal tibial shaft and local soft tissue inflammation. Preparation of the articular surface of the upper and lower ankle for arthrodesis using a transfibular approach. If necessary, correction of bone defects with iliac crest spongiosa. Stabile osteosynthesis by retrograde insertion of a compression nail. A split lower leg cast on the 2nd postoperative day, mobilization of the patient with underarm crutches with floor contact for 2 weeks, then with application of a lower leg walking cast for 8 weeks with partial weight-bearing for 4 weeks and full weight-bearing for the last 4 weeks of cast fixation. X-ray controls immediately postoperatively, then after 6 and 12 weeks. From 2006 to 2008, 12 patients (7 men, 5 women; mean age 59 years) with various indications were treated with retrograde insertion of a compression nail. All patients were routinely controlled radiologically and clinically after 2, 4, 8 and 12 weeks. Follow-up was carried out at 6, 12 and 24 months. All arthrodeses showed osseous consolidation 16 weeks postoperatively. Ten patients were able to use full weight-bearing without pain after 12 weeks. Two patients reported experiencing pain after walking for 2 h. In total three

[Endovascular repair of primary retrograde Stanford type A aortic dissection].

PubMed

Wu, H W; Sun, L; Li, D M; Jing, H; Xu, B; Wang, C T; Zhang, L

2016-10-01

Objective: To summarize the short- and mid-term results on endovascular repair of primary retrograde Stanford type A aortic dissection with an entry tear in distal aortic arch or descending aorta. Methods: Between December 2009 and December 2014, 21 male patients of primary retrograde Stanford type A aortic dissection with a mean age of (52±9) years received endovascular repair in Department of Cardiothoracic Surgery, Jinling Hospital. Among the 21 cases, 17 patients were presented as ascending aortic intramural hematoma, 4 patients as active blood flow in false lumen and partial thrombosis, 8 patients as ulcer on descending aorta combined intramural hematoma in descending aorta, and 13 patients as typical dissection changes. All patients received endovascular stent-graft repair successfully, with 15 cases in acute phase and 6 cases in chronic phase. Results: Cone stent was implanted in 13 cases, while straight stent in 8 cases, including 1 case of left common carotid-left subclavian artery bypass surgery and 1 case of restrictive bare-metal stent implantation. No perioperative stroke, paraplegia, stent fracture or displacement, limbs or abdominal organ ischemia or other severe complications occured, except for tracheotomy in 2 patients. Active blood flow in ascending aorta or aortic arch disappeared, and intramural hematoma started being absorbed on CT angiography images before discharge. All patients were alive during follow-up (6 to 72 months), and intramural hematoma in ascending aorta and aortic arch was absorbed thoroughly. Type Ⅰ endoleak and ulcer expansion were found in 1 patient, and type Ⅳ endoleak in distal stent was found in another one patient. Secondary ascending aortic dissection was found in 1 case two years later, which was cured by hybrid procedure with cardiopulmonary bypass. Conclusion: Endovascular repair of primary retrograde Stanford type A aortic dissection was safe and effective, which correlated with favorable short- and mid

Penile fracture and its treatment: is retrograde urethrograghy necessary for management of penile fracture?

PubMed

Ahmadnia, Hassan; Younesi Rostami, Mehdi; Kamalati, Ali; Imani, Mohammad Mehdi

2014-01-01

Penile fracture, being defined as rupture of the tunica albuginea of the corpus cavernosum, is uncommon. Here, we analyze findings on our patients during a 10-year period and evaluate the role of retrograde urethrography. From February 2002 to April 2012, 116 patients were admitted with penile fracture at Ghaem Medical Center. Patient history and physical examination were taken at their admittance to detect probable urethral injury. Before surgery, retrograde urethrography was performed in all patients. The size and site of the tunical rupture were recorded. Then the rupture of tunica albuginea was sutured with nonabsorbable (3-0 nylon) sutures and the ties were placed on the internal surface (continuous method). All patients were followed up for 12 months. Patients' mean age was (32.78 ± 10.61) years and ranged (16-62) years. The mechanism of trauma was sexual intercourse in 103 patients (89%) and masturbation in 13 patients (11%). The most common site of injury found after exploration was right (55%) and lateral (74%) of the corpus cavernosum. The size of the tunical rupture was from 0.5 to 3.0 cm (mean 1.88 ± 0.72). Three of the patients had Marphan's syndrome. Urethral injury was detected by retrograde urethrography in 4 patients (3%) who had macroscopic hematuria and urethrorrhagia. During 12 months follow-up, no complication was seen. There is no need to perform retrograde urethrography unless the patients have gross hematuria or urethrorrhagia. The key to success in treatment of penile fracture is to achieve a rapid diagnosis based on history and a physical examination, avoid unnecessary imaging tests and perform immediate surgery to reconstruct the site of injury.

The Retrograde Transvenous Push-Through Method: A Novel Treatment of Peripheral Arteriovenous Malformations with Dominant Venous Outflow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wohlgemuth, Walter A., E-mail: walter.wohlgemuth@ukr.de; Müller-Wille, René, E-mail: Rene.Mueller-Wille@ukr.de; Teusch, Veronika I., E-mail: Veronika.Teusch@gmx.de

2015-06-15

PurposeTo evaluate the efficacy and safety of a novel retrograde transvenous embolization technique of peripheral arteriovenous malformations (AVMs) using Onyx.Materials and MethodsWe conducted a retrospective analysis of all patients who underwent transvenous retrograde Onyx embolization of peripheral AVMs with dominant venous outflow over a 29-month period. The embolization is aimed at retrograde filling of the nidus after building a solid plug in the dominant venous outflow (push-through). Classification, clinical signs, technical aspects, clinical and technical success rates, and complications were recorded. Short-term outcome was assessed.Results11 Symptomatic patients (8 female; mean age 31.4 years) were treated at our Vascular Anomalies Center withmore » this method between January 2012 and May 2014. The AVMs were located on the upper extremity (n = 3), pelvis (n = 2), buttock (n = 2), and lower extremity (n = 4). Retrograde embolization was successfully carried out after preparatory transarterial-flow reduction in eight cases (73 %) and venous-flow reduction with Amplatzer Vascular Plugs in four cases (36 %). Complete devascularization (n = 10; 91 %) or 95 % devascularization (n = 1; 9 %) led to complete resolution (n = 8; 73 %) or improvement of clinical symptoms (n = 3; 27 %). One minor complication occurred (pain and swelling). During a mean follow-up time of 8 months, one clinically asymptomatic recurrence of AVM was detected.ConclusionInitial results suggest that retrograde transvenous Onyx embolization of peripheral AVMs with dominant venous outflow is a safe and effective novel technique with a low complication rate.« less

Telescopic Corsair in 5F Guidion for Retrograde Recanalization of Complex Chronic Total Occlusions (CTOs)

PubMed Central

Palmers, Pieter-Jan; Maeremans, Joren; Meyer-Gessner, Markus; Bataille, Yoann; Dens, Joseph

2017-01-01

Case series Patient: Male, 81 • Female, 72 • Male, 58 Final Diagnosis: CTO Symptoms: Angina pectoris Medication: — Clinical Procedure: PCI Specialty: Cardiology Objective: Unusual setting of medical care Background: Retrograde advancement of microcatheters through septal/epicardial connectors can be challenging. Although several tricks might help to do so (e.g., balloon trap of retro wire in second guiding, balloon trap of retro wire in native coronary artery, and use of antegrade extension to approximate the antegrade conduit to the retrograde gear), these tricks cannot always be applied, especially in patients with poor access. Also, puncturing, knuckling, and crossing of the distal CTO cap (or the aorta as described in 1 of the cases) sometimes needs a lot of backup of the microcatheter. Case Report: We describe 3 cases in which we used a novel telescopic technique with 5F Guidion (IMDS®) supported retrograde Corsair (Asahi®) advancement in complex CTO lesions. Conclusions: The telescopic Corsair in 5F Guidion may offer the support needed to end successfully in these situations. PMID:28456814

Pre-operative intra-articular deep tissue sampling with novel retrograde forceps improves the diagnostics in periprosthetic joint infection.

PubMed

Wimmer, Matthias D; Ploeger, Milena M; Friedrich, Max J; Hügle, Thomas; Gravius, Sascha; Randau, Thomas M

2017-07-01

Histopathological tissue analysis is a key parameter within the diagnostic algorithm for suspected periprosthetic joint infections (PJIs), conventionally acquired in open surgery. In 2014, Hügle and co-workers introduced novel retrograde forceps for retrograde synovial biopsy with simultaneous fluid aspiration of the knee joint. We hypothesised that tissue samples acquired by retrograde synovial biopsy are equal to intra-operatively acquired deep representative tissue samples regarding bacterial detection and differentiation of periprosthetic infectious membranes. Thirty patients (male n = 15, 50%; female n = 15, 50%) with 30 suspected PJIs in painful total hip arthroplasties (THAs) were included in this prospective, controlled, non-blinded trial. The results were compared with intra-operatively obtained representative deep tissue samples. In summary, 27 out of 30 patients were diagnosed correctly as infected (17/17) or non-infected (10/13). The sensitivity to predict a PJI using the Retroforce® sampling forceps in addition to standard diagnostics was 85%, the specificity 100%. Retrograde synovial biopsy is a new and rapid diagnostic procedure under local anaesthesia in patients with painful THAs with similar histological results compared to deep tissue sampling.

Retrograde Amnesia for Episodic and Semantic Memories in Amnestic Mild Cognitive Impairment.

PubMed

De Simone, Maria Stefania; Fadda, Lucia; Perri, Roberta; De Tollis, Massimo; Aloisi, Marta; Caltagirone, Carlo; Carlesimo, Giovanni Augusto

2017-01-01

Retrograde amnesia (RA), which includes loss of memory for past personal events (autobiographical RA) and for acquired knowledge (semantic RA), has been largely documented in patients with amnestic mild cognitive impairment (aMCI). However, previous studies have produced controversial results particularly concerning the temporal extent of memory impairment. Here we investigated whether, with the onset of hippocampal pathology, age of memory acquisition and retrieval frequency play different roles in modulating the progressive loss of semantic and episodic contents of retrograde memory respectively. For this purpose, aMCI patients and healthy controls were tested for the ability to recall semantic and autobiographical information related to famous public events as a function of both age of acquisition and retrieval frequency. In aMCI patients, we found that the impairment in recollecting past personal incidents was modulated by the combined action of memory age and retrieval frequency, because older and more frequently retrieved episodes are less susceptible to loss than more recent and less frequently retrieved ones. On the other side, we found that the loss of semantic information depended only on memory age, because the remoteness of the trace allows for better preservation of the memory. Our results provide evidence that the loss of the two components of retrograde memory is regulated by different mechanisms. This supports the view that diverse neural mechanisms are involved in episodic and semantic memory trace storage and retrieval, as postulated by the Multiple Trace Theory.

Diagnosis of Acute Appendicitis by Endoscopic Retrograde Appendicitis Therapy (ERAT): Combination of Colonoscopy and Endoscopic Retrograde Appendicography.

PubMed

Li, Yingchao; Mi, Chen; Li, Weizhi; She, Junjun

2016-11-01

Acute appendicitis is the most common abdominal emergency, but the diagnosis of appendicitis remains a challenge. Endoscopic retrograde appendicitis therapy (ERAT) is a new and minimally invasive procedure for the diagnosis and treatment of acute appendicitis. To investigate the diagnostic value of ERAT for acute appendicitis by the combination of colonoscopy and endoscopic retrograde appendicography (ERA). Twenty-one patients with the diagnosis of suspected uncomplicated acute appendicitis who underwent ERAT between November 2014 and January 2015 were included in this study. The main outcomes, imaging findings of acute appendicitis including colonoscopic direct-vision imaging and fluoroscopic ERA imaging, were retrospectively reviewed. Secondary outcomes included mean operative time, mean hospital stay, rate of complication, rate of appendectomy during follow-up period, and other clinical data. The diagnosis of acute appendicitis was established in 20 patients by positive ERA (5 patients) or colonoscopy (1 patient) alone or both (14 patients). The main colonoscopic imaging findings included mucosal inflammation (15/20, 75 %), appendicoliths (14/20, 70 %), and maturation (5/20, 25 %). The key points of ERA for diagnosing acute appendicitis included radiographic changes of appendix (17/20, 85 %), intraluminal appendicoliths (14/20, 70 %), and perforation (1/20, 5 %). Mean operative time of ERAT was 49.7 min, and mean hospital stay was 3.3 days. No patient converted to emergency appendectomy. Perforation occurred in one patient after appendicoliths removal was not severe and did not require invasive procedures. During at least 1-year follow-up period, only one patient underwent laparoscopic appendectomy. ERAT is a valuable procedure of choice providing a precise yield of diagnostic information for patients with suspected acute appendicitis by combination of colonoscopy and ERA.

Endogenous cannabinoids mediate retrograde signals from depolarized postsynaptic neurons to presynaptic terminals.

PubMed

Ohno-Shosaku, T; Maejima, T; Kano, M

2001-03-01

Endogenous cannabinoids are considered to function as diffusible and short-lived modulators that may transmit signals retrogradely from postsynaptic to presynaptic neurons. To evaluate this possibility, we have made a paired whole-cell recording from cultured hippocampal neurons with inhibitory synaptic connections. In about 60% of pairs, a cannabinoid agonist greatly reduced the release of the inhibitory neurotransmitter GABA from presynaptic terminals. In most of such pairs but not in those insensitive to the agonist, depolarization of postsynaptic neurons and the resultant elevation of intracellular Ca2+ concentration caused transient suppression of inhibitory synaptic currents, which is mainly due to reduction of GABA release. This depolarization-induced suppression was completely blocked by selective cannabinoid antagonists. Our results reveal that endogenous cannabinoids mediate retrograde signals from depolarized postsynaptic neurons to presynaptic terminals to cause the reduction of transmitter release.

Torques on Low-mass Bodies in Retrograde Orbit in Gaseous Disks

NASA Astrophysics Data System (ADS)

Sánchez-Salcedo, F. J.; Chametla, Raúl O.; Santillán, A.

2018-06-01

We evaluate the torque acting on a gravitational perturber on a retrograde circular orbit in the midplane of a gaseous disk. We assume that the mass of this satellite is so low that it weakly disturbs the disk (type I migration). The perturber may represent the companion of a binary system with a small mass ratio. We compare the results of hydrodynamical simulations with analytic predictions. Our 2D simulations indicate that the torque acting on a perturber with softening radius R soft can be accounted for by a scattering approach if {R}soft}< 0.3H, where H is defined as the ratio between the sound speed and the angular velocity at the orbital radius of the perturber. For R soft > 0.3H, the torque may present large and persistent oscillations, but the resultant time-averaged torque decreases rapidly with increasing R soft/H, in agreement with previous analytical studies. We then focus on the torque acting on small-size perturbers embedded in full 3D disks and argue that the density waves propagating at distances ≲H from the perturber contribute significantly to the torque because they transport angular momentum. We find a good agreement between the torque found in 3D simulations and analytical estimates based on ballistic orbits. We compare the radial migration timescales of prograde versus retrograde perturbers. For a certain range of the perturber’s mass and aspect ratio of the disk, the radial migration timescale in the retrograde case may be appreciably shorter than in the prograde case. We also provide the smoothing length required in 2D simulations in order to account for 3D effects.

Transfer and capture into distant retrograde orbits

NASA Astrophysics Data System (ADS)

Scott, Christopher J.

This dissertation utilizes theory and techniques derived from the fields of dynamical systems theory, astrodyanamics, celestial mechanics, and fluid mechanics to analyze the phenomenon of satellite capture and interrelated spacecraft transfers in restricted three-body systems. The results extend current knowledge and understanding of capture dynamics in the context of astrodynamics and celestial mechanics. Manifold theory, fast Lyapunov indicator maps, and the classification of space structure facilitate an analysis of the transport of objects from the chaotic reaches of the solar system to the distant retrograde region in the sun-Jupiter system. Apart from past studies this dissertation considers the role of the complex lobe structure encompassing stable regions in the circular restricted three-body problem. These structures are shown to be responsible for the phenomenon of sticky orbits and the transport of objects among stable regions. Since permanent capture can only be achieved through a change in energy, fast Lyapunov indicator maps and other methods which reveal the structure of the conservative system are used to discern capture regions and identify the underpinnings of the dynamics. Fast Lyapunov indicator maps provide an accurate classification of orbits of permanent capture and escape, yet monopolize computational resources. In anticipation of a fully three-dimensional analysis in the dissipative system a new mapping parameter is introduced based on energy degradation and averaged velocity. Although the study specifically addresses the sun-Jupiter system, the qualitative results and devised techniques can be applied throughout the solar system and to capture about extrasolar planets. Extending the analysis beyond the exterior of the stable distant retrograde region fosters the construction of transfer orbits from low-Earth orbit to a stable periodic orbit at the center of the stable distant retrograde region. Key to this analysis is the predictability of

Functional involvement of TMF/ARA160 in Rab6-dependent retrograde membrane traffic.

PubMed

Yamane, Junko; Kubo, Akiharu; Nakayama, Kazuhisa; Yuba-Kubo, Akiko; Katsuno, Tatsuya; Tsukita, Shoichiro; Tsukita, Sachiko

2007-10-01

The small GTPase Rab6 regulates retrograde membrane traffic from endosomes to the Golgi apparatus and from the Golgi to the endoplasmic reticulum (ER). We examined the role of a Rab6-binding protein, TMF/ARA160 (TATA element modulatory factor/androgen receptor-coactivator of 160 kDa), in this process. High-resolution immunofluorescence imaging revealed that TMF signal surrounded Rab6-positive Golgi structures and immunoelectron microscopy revealed that TMF is concentrated at the budding structures localized at the tips of cisternae. The knockdown of either TMF or Rab6 by RNA interference blocked retrograde transport of endocytosed Shiga toxin from early/recycling endosomes to the trans-Golgi network, causing missorting of the toxin to late endosomes/lysosomes. However, the TMF knockdown caused Rab6-dependent displacement of N-acetylgalactosaminyltransferase-2 (GalNAc-T2), but not beta1,4-galactosyltransferase (GalT), from the Golgi. Analyses using chimeric proteins, in which the cytoplasmic regions of GalNAc-T2 and GalT were exchanged, revealed that the cytoplasmic region of GalNAc-T2 plays a crucial role in its TMF-dependent Golgi retention. These observations suggest critical roles for TMF in two Rab6-dependent retrograde transport processes: one from endosomes to the Golgi and the other from the Golgi to the ER.

Mozart, Mozart Rhythm and Retrograde Mozart Effects: Evidences from Behaviours and Neurobiology Bases

PubMed Central

Xing, Yingshou; Xia, Yang; Kendrick, Keith; Liu, Xiuxiu; Wang, Maosen; Wu, Dan; Yang, Hua; Jing, Wei; Guo, Daqing; Yao, Dezhong

2016-01-01

The phenomenal finding that listening to Mozart K.448 enhances performance on spatial tasks has motivated a continuous surge in promoting music education over the past two decades. But there have been inconsistent reports in previous studies of the Mozart effect. Here conducted was a systematic study, with Mozart and retrograde Mozart music, Mozart music rhythm and pitch, behaviours and neurobiology tests, rats and humans subjects. We show that while the Mozart K.448 has positive cognitive effects, the retrograde version has a negative effect on rats’ performance in the Morris water maze test and on human subjects’ performance in the paper folding and cutting test and the pencil-and-paper maze test. Such findings are further confirmed by subsequent immunohistochemical analyses in rats on the neurogenesis and protein levels of BDNF and its receptor, TrkB. Furthermore, when the rhythm and pitch of the normal and retrograde Mozart music are manipulated independently, the learning performance of the rats in the Morris water maze test indicated that rhythm is a crucial element in producing the behavioural effects. These findings suggest that the nature of Mozart effect is the Mozart rhythm effect, and indicate that different music may have quite different to opposite effects. Further study on rhythm effect may provide clues to understand the common basis over animals from rats to humans. PMID:26795072

COPI-mediated retrograde trafficking from the Golgi to the ER regulates EGFR nuclear transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Ying-Nai; Wang, Hongmei; Yamaguchi, Hirohito

2010-09-03

Research highlights: {yields} ARF1 activation is involved in the EGFR transport to the ER and the nucleus. {yields} Assembly of {gamma}-COP coatomer mediates EGFR transport to the ER and the nucleus. {yields} Golgi-to-ER retrograde trafficking regulates nuclear transport of EGFR. -- Abstract: Emerging evidence indicates that cell surface receptors, such as the entire epidermal growth factor receptor (EGFR) family, have been shown to localize in the nucleus. A retrograde route from the Golgi to the endoplasmic reticulum (ER) is postulated to be involved in the EGFR trafficking to the nucleus; however, the molecular mechanism in this proposed model remains unexplored.more » Here, we demonstrate that membrane-embedded vesicular trafficking is involved in the nuclear transport of EGFR. Confocal immunofluorescence reveals that in response to EGF, a portion of EGFR redistributes to the Golgi and the ER, where its NH{sub 2}-terminus resides within the lumen of Golgi/ER and COOH-terminus is exposed to the cytoplasm. Blockage of the Golgi-to-ER retrograde trafficking by brefeldin A or dominant mutants of the small GTPase ADP-ribosylation factor, which both resulted in the disassembly of the coat protein complex I (COPI) coat to the Golgi, inhibit EGFR transport to the ER and the nucleus. We further find that EGF-dependent nuclear transport of EGFR is regulated by retrograde trafficking from the Golgi to the ER involving an association of EGFR with {gamma}-COP, one of the subunits of the COPI coatomer. Our findings experimentally provide a comprehensive pathway that nuclear transport of EGFR is regulated by COPI-mediated vesicular trafficking from the Golgi to the ER, and may serve as a general mechanism in regulating the nuclear transport of other cell surface receptors.« less

Feasibility of Retrograde Ureteral Contrast Injection to Guide Ultrasonographic Percutaneous Renal Access in the Nondilated Collecting System.

PubMed

Usawachintachit, Manint; Tzou, David T; Mongan, John; Taguchi, Kazumi; Weinstein, Stefanie; Chi, Thomas

2017-02-01

Ultrasound-guided percutaneous nephrolithotomy (PCNL) has become increasingly utilized. Patients with nondilated collecting systems represent a challenge: the target calix is often difficult to visualize. Here we report pilot study results for retrograde ultrasound contrast injection to aid in percutaneous renal access during ultrasound-guided PCNL. From April to July 2016, consecutive patients over the age of 18 years with nondilated collecting systems on preoperative imaging who presented for PCNL were enrolled. B-mode ultrasound imaging was compared with contrast-enhanced mode with simultaneous retrograde injection of Optison™ via an ipsilateral ureteral catheter. Five patients (four males and one female) with renal stones underwent PCNL with retrograde ultrasound contrast injection during the study period. Mean body mass index was 28.3 ± 5.6 kg/m 2 and mean stone size was 24.5 ± 12.0 mm. Under B-mode ultrasound, all patients demonstrated nondilated renal collecting systems that appeared as hyperechoic areas, where it was difficult to identify a target calix for puncture. Retrograde contrast injection facilitated delineation of all renal calices initially difficult to visualize under B-mode ultrasound. Renal puncture was then performed effectively in all cases with a mean puncture time of 55.4 ± 44.8 seconds. All PCNL procedures were completed without intraoperative complications and no adverse events related to ultrasound contrast injection occurred. Retrograde ultrasound contrast injection as an aide for renal puncture during PCNL is a feasible technique. By improving visualization of the collecting system, it facilitates needle placement in challenging patients without hydronephrosis. Future larger scale studies comparing its use to standard ultrasound-guided technique will be required to validate this concept.

Formation Flying in Earth, Libration, and Distant Retrograde Orbits

NASA Technical Reports Server (NTRS)

Folta, David C.

2004-01-01

This slide presentation examines the current and future state of formation flying, LEO formations, control strategies for flight in the vicinity of the libration points, and distant retrograde orbit formations. This discussion of LEO formations includes background on perturbation theory/accelerations and LEO formation flying. The discussion of strategies for formation flight in the vicinity of the libration points includes libration missions and natural and controlled libration orbit formations. A reference list is included.

Stem-cell therapy for dilated cardiomyopathy: a pilot study evaluating retrograde coronary venous delivery.

PubMed

Pogue, B; Estrada, A H; Sosa-Samper, I; Maisenbacher, H W; Lamb, K E; Mincey, B D; Erger, K E; Conlon, T J

2013-07-01

To evaluate retrograde coronary venous stem-cell delivery for Dobermanns with dilated cardiomyopathy. Retrograde coronary venous delivery of adipose-derived mesenchymal stem cells transduced with tyrosine mutant adeno-associated virus 2 to express stromal-derived factor-1 was performed in Dobermanns with dilated cardiomyopathy. Cases were followed for 2 years and electrocardiograms (ECG), echocardiograms and Holter monitoring were performed. Delivery of cells was feasible in 15 of 15 dogs. One dog died following the development of ventricular fibrillation 24 hours after cell delivery. The remaining 14 dogs were discharged the following day without complications. Echocardiographic measurements of left ventricular size and function showed continued progression of disease. On the basis of Kaplan-Meier product limit estimates, median survival for dogs following stem-cell delivery was 620 days (range of 1-799 days). When including only the occult-dilated cardiomyopathy population and excluding those dogs already in congestive heart failure, median survival was 652 days (range of 46-799 days). Retrograde venous delivery of tyrosine mutant adeno-associated virus 2-stromal-derived factor-1 adipose-derived mesenchymal stem cells appears safe. Stem-cell therapy in dogs with occult-dilated cardiomyopathy does not appear to offer advantage compared to recently published survival data in similarly affected Dobermanns. © 2013 British Small Animal Veterinary Association.

Retrograde amnesia: a study of its relation to anterograde amnesia and semantic memory deficits.

PubMed

Schmidtke, K; Vollmer, H

1997-04-01

This group study of 24 amnesic patients and 40 control subjects examined the hypothesis that retrograde memory deficits result from a combination of two impairment mechanisms: (1) a deficit in the retrieval of contents that is related to dysfunctioning of the hippocampal anterograde memory system, and (2) a deficit in the storage and/or retrieval of contents that is related to concomitant neocortical lesions. Retrograde amnesia was evaluated with the use of new Famous Persons and Autobiographical Memory Tests. The postulated components of retrograde memory impairment were assessed using the Wechsler Memory Scale and a new Semantic Memory Test, respectively. Regression analyses showed that recent episodic autobiography was exclusively related to the hippocampal component, while memory for famous persons and childhood autobiography was related to the neocortical component. In the case of details concerning people of recent fame, both components were identified as independent determinants. The temporal gradient of patients' impairment at the Famous Persons Test was marked for detailed knowledge, but small for overlearned knowledge. The present results thus support the combination hypothesis. They conform to the view that the transition from a hippocampus-dependent to a neocortex-dependent mnemonic representation of new contents is mediated by reiteration, and occurs within 5-10 years.

Comparison of knee function after antegrade and retrograde intramedullary nailing for diaphyseal femoral fractures: results of isokinetic evaluation.

PubMed

Daglar, Bulent; Gungor, Ertugrul; Delialioglu, Onder M; Karakus, Dilek; Ersoz, Murat; Tasbas, Bulent Adil; Bayrakci, Kenan; Gunel, Ugur

2009-10-01

To evaluate knee function in patients having femoral diaphyseal fractures treated with antegrade or retrograde intramedullary nail insertion. Prospective. Level I referral center. Seventy patients having 71 OTA 32 fractures were randomly allocated into 2 groups to be treated with either antegrade or retrograde intramedullary nails inserted with reaming. Antegrade nail in 41 fractures and retrograde femoral intramedullary nails in 30 fractures. Postoperative knee range of motion, Lysholm Knee Score, and isokinetic knee muscle function testing at least 6 months after documented fracture healing, minimum 1 year postoperatively. Groups had similar data with regard to demographics and injury patterns. Mean follow-up time was 44 (range: 25-80) months. Mean knee flexion angle was 132 and 134 degrees, and mean Lysholm Score was 84 and 83.1 in antegrade and retrograde groups, respectively (P = 0.893 and P = 0.701). Isokinetic evaluation revealed similar results for peak torque deficiencies at 30 and 180 degrees per second and total work deficiencies at 180 degrees per second (P > 0.05). Age affected the knee functioning as the higher the age of the patient is, the lower the Lysholm Score and knee flexion angle (r = -0.449, P = 0.0321 and r = -0.568, P = 0.001, respectively). Knee function seems to have similar clinical results after either antegrade or retrograde nail insertion for femoral diaphyseal fractures when knee range of motion, Lysholm Scores, and isokinetic knee evaluation are considered as outcome measures. With increasing patient age, a decrease in knee functioning should be anticipated in patients with femoral fractures treated with intramedullary nails regardless of technique.

The Impact of Preoperative α-Adrenergic Antagonists on Ureteral Access Sheath Insertion Force and the Upper Limit of Force Required to Avoid Ureteral Mucosal Injury: A Randomized Controlled Study.

PubMed

Koo, Kyo Chul; Yoon, Jun-Ho; Park, No-Cheol; Lee, Hye Sun; Ahn, Hyun Kyu; Lee, Kwang Suk; Kim, Do Kyung; Cho, Kang Su; Chung, Byung Ha; Hong, Chang Hee

2018-06-01

Excessive bulking force during primary access of the ureteral access sheath may induce ureteral injury. We investigated the efficacy of preoperative α-blockade to reduce ureteral access sheath insertion force and determine the upper limit required to avoid ureteral injury. In this randomized controlled trial 135 patients from a single institution who had ureteropelvic junction or renal pelvis stones and were scheduled to undergo retrograde intrarenal surgery were prospectively enrolled from December 2015 to January 2017. Of the patients 41 and 42 were randomly assigned to the control and experimental groups, respectively. The experimental group received α-blockade preoperatively. The 21 patients who were pre-stented were assessed separately. We developed a homemade device to measure maximal ureteral access sheath insertion force. Our ureteral access sheath insertion force measurement device showed excellent reproducibility. Higher insertion velocity resulted in greater maximal sheath insertion force. Maximal insertion force in the α-blockade group was significantly lower than in the control group at the ureterovesical junction (p = 0.008) and the proximal ureter (p = 0.036). Maximal insertion force in the α-blockade group was comparable to that in pre-stented patients. Female patients and patients 70 years old or older showed a lower maximal ureteral access sheath insertion force than their counterparts. The rate of grade 2 or greater ureteral injury was lower in the α-blockade group than in controls (p = 0.038). No injury occurred in any case in which ureteral access sheath insertion force did not exceed 600 G. Preoperative α-blockade and slow sheath placement may reduce maximal ureteral access sheath insertion force. If the force exceeds 600 G, a smaller diameter sheath may be an alternative. Alternatively the procedure can be terminated and followed later by pre-stented retrograde intrarenal surgery. Copyright © 2018 American Urological Association

N-Acetylcysteine Prevents Retrograde Motor Neuron Death after Neonatal Peripheral Nerve Injury.

PubMed

Catapano, Joseph; Zhang, Jennifer; Scholl, David; Chiang, Cameron; Gordon, Tessa; Borschel, Gregory H

2017-05-01

Neuronal death may be an overlooked and unaddressed component of disability following neonatal nerve injuries, such as obstetric brachial plexus injury. N-acetylcysteine and acetyl-L-carnitine improve survival of neurons after adult nerve injury, but it is unknown whether they improve survival after neonatal injury, when neurons are most susceptible to retrograde neuronal death. The authors' objective was to examine whether N-acetylcysteine or acetyl-L-carnitine treatment improves survival of neonatal motor or sensory neurons in a rat model of neonatal nerve injury. Rat pups received either a sciatic nerve crush or transection injury at postnatal day 3 and were then randomized to receive either intraperitoneal vehicle (5% dextrose), N-acetylcysteine (750 mg/kg), or acetyl-L-carnitine (300 mg/kg) once or twice daily. Four weeks after injury, surviving neurons were retrograde-labeled with 4% Fluoro-Gold. The lumbar spinal cord and L4/L5 dorsal root ganglia were then harvested and sectioned to count surviving motor and sensory neurons. Transection and crush injuries resulted in significant motor and sensory neuron loss, with transection injury resulting in significantly less neuron survival. High-dose N-acetylcysteine (750 mg/kg twice daily) significantly increased motor neuron survival after neonatal sciatic nerve crush and transection injury. Neither N-acetylcysteine nor acetyl-L-carnitine treatment improved sensory neuron survival. Proximal neonatal nerve injuries, such as obstetric brachial plexus injury, produce significant retrograde neuronal death after injury. High-dose N-acetylcysteine significantly increases motor neuron survival, which may improve functional outcomes after obstetrical brachial plexus injury.

Formation of Tidally Induced Bars in Galactic Flybys: Prograde versus Retrograde Encounters

NASA Astrophysics Data System (ADS)

Łokas, Ewa L.

2018-04-01

Bars in disk galaxies can be formed by interactions with other systems, including those of comparable mass. It has long been established that the effect of such interactions on galaxy morphology depends strongly on the orbital configuration, in particular the orientation of the intrinsic spin of the galactic disk with respect to its orbital angular momentum. Prograde encounters modify the morphology strongly, including the formation of tidally induced bars, while retrograde flybys should have little effect on morphology. Recent works on the subject reached conflicting conclusions, one using the impulse approximation and claiming no dependence on this angle in the properties of tidal bars. To resolve the controversy, we performed self-consistent N-body simulations of hyperbolic encounters between two identical Milky Way-like galaxies assuming different velocities and impact parameters, with one of the galaxies on a prograde and the other on a retrograde orbit. The galaxies were initially composed of an exponential stellar disk and an NFW dark halo, and they were stable against bar formation in isolation for 3 Gyr. We find that strong tidally induced bars form only in galaxies on prograde orbits. For smaller impact parameters and lower relative velocities, the bars are stronger and have lower pattern speeds. Stronger bars undergo extended periods of buckling instability that thicken their vertical structure. The encounters also lead to the formation of two-armed spirals with strength inversely proportional to the strength of the bars. We conclude that proper modeling of prograde and retrograde encounters cannot rely on the simplest impulse approximation.

Vertical canaliculotomy with retrograde expression of concretions for the treatment of canaliculitis.

PubMed

Perumal, Balaji; Meyer, Dale R

2015-01-01

To evaluate the efficacy and safety of the technique of vertical canaliculotomy with retrograde expression of concretions for the treatment of canaliculitis. This is a retrospective, interventional case series. Patients who underwent vertical canaliculotomy by 1 surgeon (D.R.M.) from August 2011 to December 2013 were identified. On initial diagnosis of canaliculitis, all patients were treated with a combination antibiotic/steroid eyedrop and an oral antibiotic. The procedure was performed 1 month later and consisted of a 2-mm vertical canaliculotomy with sharp-tipped scissors followed by retrograde expression of the canalicular contents by compressing the canaliculus medial to lateral with 2 cotton-tipped applicators. All concretion specimens were sent for pathologic examination. Pre- and postoperative subjective complaints and objective findings on examination, including eyelid thickening and probing/irrigation results, were recorded. Canalicular contents were readily expressed from all 8 patients who underwent the procedure. Pathologic analysis revealed Actinomyces species in 5 of 8 specimens and other Gram-negative and Gram-positive bacteria in the remaining specimens. All patients reported significant improvement in their symptoms and were patent to irrigation. Many reported surgical procedures for the treatment of canaliculitis involve the use of a curette, an instrument with sharp edges, that could potentially damage the lining of the canaliculus. Previous studies examining these procedures have reported canalicular stricture and dysfunction postoperatively. The current technique of vertical canaliculotomy with retrograde expression of canalicular contents described herein has been effective, limits iatrogenic trauma, and had a low incidence of postoperative complications in this series.

Minimizing radiation exposure during percutaneous nephrolithotomy.

PubMed

Chen, T T; Preminger, G M; Lipkin, M E

2015-12-01

Given the recent trends in growing per capita radiation dose from medical sources, there have been increasing concerns over patient radiation exposure. Patients with kidney stones undergoing percutaneous nephrolithotomy (PNL) are at particular risk for high radiation exposure. There exist several risk factors for increased radiation exposure during PNL which include high Body Mass Index, multiple access tracts, and increased stone burden. We herein review recent trends in radiation exposure, radiation exposure during PNL to both patients and urologists, and various approaches to reduce radiation exposure. We discuss incorporating the principles of As Low As reasonably Achievable (ALARA) into clinical practice and review imaging techniques such as ultrasound and air contrast to guide PNL access. Alternative surgical techniques and approaches to reducing radiation exposure, including retrograde intra-renal surgery, retrograde nephrostomy, endoscopic-guided PNL, and minimally invasive PNL, are also highlighted. It is important for urologists to be aware of these concepts and techniques when treating stone patients with PNL. The discussions outlined will assist urologists in providing patient counseling and high quality of care.

NEXT GENERATION OF TELESCOPES OR DYNAMICS REQUIRED TO DETERMINE IF EXO-MOONS HAVE PROGRADE OR RETROGRADE ORBITS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, Karen M.; Fujii, Yuka

2014-08-20

We survey the methods proposed in the literature for detecting moons of extrasolar planets in terms of their ability to distinguish between prograde and retrograde moon orbits, an important tracer of the moon formation channel. We find that most moon detection methods, in particular, sensitive methods for detecting moons of transiting planets, cannot observationally distinguishing prograde and retrograde moon orbits. The prograde and retrograde cases can only be distinguished where the dynamical evolution of the orbit due to, e.g., three body effects is detectable, where one of the two cases is dynamically unstable, or where new observational facilities, which canmore » implement a technique capable of differentiating the two cases, come online. In particular, directly imaged planets are promising targets because repeated spectral and photometric measurements, which are required to determine moon orbit direction, could also be conducted with the primary interest of characterizing the planet itself.« less

Protein Kinase A Activity Is Necessary for Fission and Fusion of Golgi to Endoplasmic Reticulum Retrograde Tubules

PubMed Central

Tenorio, María J.; Luchsinger, Charlotte; Mardones, Gonzalo A.

2015-01-01

It is becoming increasingly accepted that together with vesicles, tubules play a major role in the transfer of cargo between different cellular compartments. In contrast to our understanding of the molecular mechanisms of vesicular transport, little is known about tubular transport. How signal transduction molecules regulate these two modes of membrane transport processes is also poorly understood. In this study we investigated whether protein kinase A (PKA) activity regulates the retrograde, tubular transport of Golgi matrix proteins from the Golgi to the endoplasmic reticulum (ER). We found that Golgi-to-ER retrograde transport of the Golgi matrix proteins giantin, GM130, GRASP55, GRASP65, and p115 was impaired in the presence of PKA inhibitors. In addition, we unexpectedly found accumulation of tubules containing both Golgi matrix proteins and resident Golgi transmembrane proteins. These tubules were still attached to the Golgi and were highly dynamic. Our data suggest that both fission and fusion of retrograde tubules are mechanisms regulated by PKA activity. PMID:26258546

Arp2/3 complex–dependent actin networks constrain myosin II function in driving retrograde actin flow

PubMed Central

Yang, Qing; Zhang, Xiao-Feng; Pollard, Thomas D.

2012-01-01

The Arp2/3 complex nucleates actin filaments to generate networks at the leading edge of motile cells. Nonmuscle myosin II produces contractile forces involved in driving actin network translocation. We inhibited the Arp2/3 complex and/or myosin II with small molecules to investigate their respective functions in neuronal growth cone actin dynamics. Inhibition of the Arp2/3 complex with CK666 reduced barbed end actin assembly site density at the leading edge, disrupted actin veils, and resulted in veil retraction. Strikingly, retrograde actin flow rates increased with Arp2/3 complex inhibition; however, when myosin II activity was blocked, Arp2/3 complex inhibition now resulted in slowing of retrograde actin flow and veils no longer retracted. Retrograde flow rate increases induced by Arp2/3 complex inhibition were independent of Rho kinase activity. These results provide evidence that, although the Arp2/3 complex and myosin II are spatially segregated, actin networks assembled by the Arp2/3 complex can restrict myosin II–dependent contractility with consequent effects on growth cone motility. PMID:22711700

Successful Treatment of Mesenteric Varices After Living Donor Liver Transplantation with Retrograde Transvenous Obliteration Via an Abdominal Wall Vein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ikeda, Osamu, E-mail: osamu-3643ik@do9.enjoy.ne.jp; Tamura, Yoshitaka; Nakasone, Yutaka

2010-06-15

Balloon-occluded retrograde transvenous obliteration is an established treatment for gastric varices; it has been used more rarely to treat mesenteric varices. We report a 12-year-old girl who had received a living donor liver transplant and suffered melena due to ruptured mesenteric varices. We addressed treatment of the mesenteric varices by retrograde transvenous obliteration of an abdominal wall collateral vein detected by superior mesenteric arteriography.

Transgene expression in target-defined neuron populations mediated by retrograde infection with adeno-associated viral vectors.

PubMed

Rothermel, Markus; Brunert, Daniela; Zabawa, Christine; Díaz-Quesada, Marta; Wachowiak, Matt

2013-09-18

Tools enabling the manipulation of well defined neuronal subpopulations are critical for probing complex neuronal networks. Cre recombinase (Cre) mouse driver lines in combination with the Cre-dependent expression of proteins using viral vectors--in particular, recombinant adeno-associated viral vectors (rAAVs)--have emerged as a widely used platform for achieving transgene expression in specified neural populations. However, the ability of rAAVs to further specify neuronal subsets on the basis of their anatomical connectivity has been reported as limited or inconsistent. Here, we systematically tested a variety of widely used neurotropic rAAVs for their ability to mediate retrograde gene transduction in the mouse brain. We tested pseudotyped rAAVs of several common serotypes (rAAV 2/1, 2/5, and 2/9) as well as constructs both with and without Cre-dependent expression switches. Many of the rAAVs tested--in particular, though not exclusively, Cre-dependent vectors--showed a robust capacity for retrograde infection and transgene expression. Retrograde expression was successful over distances as large as 6 mm and in multiple neuron types, including olfactory projection neurons, neocortical pyramidal cells projecting to distinct targets, and corticofugal and modulatory projection neurons. Retrograde infection using transgenes such as ChR2 allowed for optical control or optically assisted electrophysiological identification of neurons defined genetically as well as by their projection target. These results establish a widely accessible tool for achieving combinatorial specificity and stable, long-term transgene expression to isolate precisely defined neuron populations in the intact animal.

Transgene Expression in Target-Defined Neuron Populations Mediated by Retrograde Infection with Adeno-Associated Viral Vectors

PubMed Central

Rothermel, Markus; Brunert, Daniela; Zabawa, Christine; Díaz-Quesada, Marta

2013-01-01

Tools enabling the manipulation of well defined neuronal subpopulations are critical for probing complex neuronal networks. Cre recombinase (Cre) mouse driver lines in combination with the Cre-dependent expression of proteins using viral vectors—in particular, recombinant adeno-associated viral vectors (rAAVs)—have emerged as a widely used platform for achieving transgene expression in specified neural populations. However, the ability of rAAVs to further specify neuronal subsets on the basis of their anatomical connectivity has been reported as limited or inconsistent. Here, we systematically tested a variety of widely used neurotropic rAAVs for their ability to mediate retrograde gene transduction in the mouse brain. We tested pseudotyped rAAVs of several common serotypes (rAAV 2/1, 2/5, and 2/9) as well as constructs both with and without Cre-dependent expression switches. Many of the rAAVs tested—in particular, though not exclusively, Cre-dependent vectors—showed a robust capacity for retrograde infection and transgene expression. Retrograde expression was successful over distances as large as 6 mm and in multiple neuron types, including olfactory projection neurons, neocortical pyramidal cells projecting to distinct targets, and corticofugal and modulatory projection neurons. Retrograde infection using transgenes such as ChR2 allowed for optical control or optically assisted electrophysiological identification of neurons defined genetically as well as by their projection target. These results establish a widely accessible tool for achieving combinatorial specificity and stable, long-term transgene expression to isolate precisely defined neuron populations in the intact animal. PMID:24048849

Arthroscopic retrograde osteochondral autologous transplantation to chondral lesion in femoral head.

PubMed

Cetinkaya, Sarper; Toker, Berkin; Taser, Omer

2014-06-01

This report describes the treatment of 2 cases of full-thickness cartilage defect of the femoral head. The authors performed osteochondral autologous transplantation with a different technique that has not been reported to date. One patient was 37 years old, and the other was 42 years old. Both presented with hip pain. In both patients, radiograph and magnetic resonance imaging scan showed a focal chondral defect on the weight-bearing area of the femoral head and acetabular impingement. A retrograde osteochondral autologous transplantation technique combined with hip arthroscopy and arthroscopic impingement treatment was performed. After a 2-month recovery period, the symptoms were resolved. In the first year of follow-up, Harris Hip scores improved significantly (case 1, 56.6 to 87.6; case 2, 58.6 to 90). The technique described yielded good short- and midterm clinical and radiologic outcomes. To the authors' knowledge, this report is the first to describe a retrograde osteochondral transplantation technique performed with hip arthroscopy in the femoral head. Copyright 2014, SLACK Incorporated.

Direct visualization of minimal cerebral capillary flow during retrograde cerebral perfusion: an intravital fluorescence microscopy study in pigs.

PubMed

Duebener, Lennart F; Hagino, Ikuo; Schmitt, Katharina; Sakamoto, Takahiko; Stamm, Christof; Zurakowski, David; Schäfers, Hans-Joachim; Jonas, Richard A

2003-04-01

Retrograde cerebral perfusion (RCP) is used in some centers during aortic arch surgery for brain protection during hypothermic circulatory arrest. It is still unclear however whether RCP provides adequate microcirculatory blood flow at a capillary level. We used intravital microscopy to directly visualize the cerebral capillary blood flow in a piglet model of RCP. Twelve pigs (weight 9.7 +/- 0.9 kg) were divided into two groups (n = 6 each): deep hypothermic circulatory arrest (DHCA) and RCP. After the creation of a window over the parietal cerebral cortex, pigs underwent 10 minutes of normothermic bypass and 40 minutes of cooling to 15 degrees C on cardiopulmonary bypass ([CPB] pH-stat, hemocrit 30%, pump flow 100 mL x kg(-1) x min(-1)). This was followed by 45 minutes of DHCA and rewarming on CPB to 37 degrees C. In the RCP group the brain was retrogradely perfused (pump flow 30 mL x kg(-1) x min(-1)) during DHCA through the superior vena cava after inferior vena cava occlusion. Plasma was labeled with fluorescein-isothiocyanate-dextran for assessing microvascular diameter and functional capillary density (FCD), defined as total length of erythrocyte-perfused capillaries per observation area. Cerebral tissue oxygenation was determined by nicotinamide adenine dinucleotide hydrogen (NADH) autofluorescence, which increases during tissue ischemia. During normothermic and hypothermic antegrade cerebral perfusion the FCD did not significantly change from base line (97% +/- 14% and 96% +/- 12%, respectively). During retrograde cerebral perfusion the FCD decreased highly significantly to 2% +/- 2% of base line values (p < 0.001). Thus there was no evidence of significant capillary blood flow during retrograde cerebral perfusion. The microvascular diameter of cerebral arterioles that were slowly perfused significantly decreased to 27% +/- 6% of base line levels during RCP. NADH fluorescence progressively and significantly increased during RCP, indicating poorer tissue

Comparison of Balloon-Occluded Retrograde Transvenous Obliteration (BRTO) Using Ethanolamine Oleate (EO), BRTO Using Sodium Tetradecyl Sulfate (STS) Foam and Vascular Plug-Assisted Retrograde Transvenous Obliteration (PARTO)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Young Hwan; Kim, Young Hwan, E-mail: yhkim68@dsmc.or.kr; Kim, Chan Sun

PurposeTo compare the clinical outcomes of balloon-occluded retrograde transvenous obliteration (BRTO) using ethanolamine oleate (EO), BRTO using sodium tetradecyl sulfate (STS) foam, and vascular plug-assisted retrograde transvenous obliteration (PARTO).Materials and MethodsFrom April 2004 to February 2015, ninety-five patients underwent retrograde transvenous obliteration for gastric varices were analyzed retrospectively. BRTO with EO was performed in 49 patients, BRTO with STS foam in 25, and PARTO in 21. Among them, we obtained follow-up data in 70 patients. Recurrence of gastric varices was evaluated by follow-up endoscopy or CT. Medical records were reviewed for the clinical efficacy. Statistical analyses were performed by Kaplan–Meiermore » method, Chi-square, Fisher’s, and Kruskal–Wallis tests.ResultsTechnical and clinical success was 94.7 %. As major complications, a hemoglobinuria and a death due to disseminated intravascular coagulation (DIC) were occurred in two patients with BRTO using EO. Recurrence occurred more frequently in PARTO group (P < 0.05). Recurrence occurred in three patients in BRTO using EO group and four patients in PARTO group with 3.2 and 32.8 % of each expected 1-year recurrence rates. There was no recurrence in BRTO using STS group. Abdominal pain occurred more frequently in BRTO using EO than BRTO using STS foam and PARTO (P < 0.05). Procedure time of PARTO was shorter than two conventional BRTOs (P < 0.05).ConclusionsBRTO using STS foam or PARTO is better than BRTO using EO for treatment of gastric varices in terms of complication or procedure time. However, PARTO showed frequent recurrence of gastric varices during the long-term follow-up rather than BRTO.« less

THE INTRARENAL DISTRIBUTION OF TRITIATED PARA-AMINOHIPPURIC ACID DETERMINED BY A MODIFIED TECHNIQUE OF SECTION FREEZE-DRY RADIOAUTOGRAPHY

PubMed Central

Bordier, Betrand; Ornstein, Leonard; Wedeen, Richard P.

1970-01-01

Section freeze-dry radioautography has been used to examine the intrarenal distribution of a water-soluble organic acid (para-aminohippuric acid (PAH-3H)) under constant-infusion, steady-state conditions in mouse and rat kidney in vivo. The technique described here has the following advantages: (a) Sectioning and freeze-drying are accomplished in a closed cryostat at temperatures below -40°C; (b) Handling of the section is facilitated by mounting of the section-to-be on adhesive-coated Saran Wrap prior to cutting; (c) Unembedded freeze-dried sections are attached to photographic film at ambient temperature in the dark room; (d) Fixation follows completion of radioautographic exposure and precedes photographic development; (e) Permanent close contact is maintained between tissue and film. Morphologic preservation compared favorably with that obtained by optimal fixation techniques, which, however, permit diffusion. Cellular accumulation of PAH-3H during secretion was demonstrated in the proximal tubule under steady-state conditions in vivo. The cellular concentration of PAH-3H was uniform throughout the length of the proximal tubule in mouse and rat kidney. PMID:4349130

Hippocampus and Retrograde Amnesia in the Rat Model: A Modest Proposal for the Situation of Systems Consolidation

PubMed Central

Sutherland, Robert J.; Sparks, Fraser; Lehmann, Hugo

2010-01-01

The properties of retrograde amnesia after damage to the hippocampus have been explicated with some success using a rat model of human medial temporal lobe amnesia. We review the results of this experimental work with rats focusing on several areas of consensus in this growing literature. We evaluate the theoretically significant hypothesis that hippocampal retrograde amnesia normally exhibits a temporal gradient, affecting recent, but sparing remote memories. Surprisingly, the evidence does not provide much support for the idea that there is a lengthy process of systems consolidation following a learning episode. Instead, recent and remote memories tend to be equally affected. The extent of damage to the hippocampus is a significant factor in this work since it is likely that spared hippocampal tissue can support at least partial memory retrieval. With extensive hippocampal damage gradients are flat or, in the case of memory tasks with flavour/odour retrieval cues, the retrograde amnesia covers a period of about 1 – 3 days. There is consistent evidence that at the time of learning the hippocampus interferes with or overshadows memory acquisition by other systems. This contributes to the breadth and severity of retrograde amnesia relative to anterograde amnesia in the rat. The fact that multiple, distributed learning episodes can overcome this overshadowing is consistent with a parallel dual-store theory or a Distributed Reinstatement Theory in which each learning episode triggers a short period of memory replay that provides a brief hippocampal-dependent systems consolidation. PMID:20430043

[Tibio-talo-calcaneal arthrodesis by retrograde intramedullary nail--a case report].

PubMed

Lipiński, Łukasz; Synder, Marek; Sibiński, Marcin

2011-01-01

We described a case of 64 year old overweight women, who was treated with revision tibio-talo-calcaneal artrodesis with the use of retrograde intramedullary nail. The procedure was performed after failed primary arthrodesis with the use of lateral approach and fibula osteotomy. Stabilization with intramedullary nail gave good clinical and functional result with a good bone healing.

The Role of Central and Enteric Nervous Systems in the Control of the Retrograde Giant Contraction

PubMed Central

Lang, Ivan M

2016-01-01

Background/Aims The role of the enteric (ENS) and central (CNS) nervous systems in the control of the retrograde giant contraction (RGC) associated with vomiting is unknown. Methods The effects of myotomy or mesenteric nerve transection (MNT) on apomorphine-induced emesis were investigated in 18 chronically instrumented dogs Results Neither surgery affected the RGC orad of the surgical site or the velocity of the RGC over the entire small intestine. Myotomy blocked the RGC for 17 ± 5 cm aborad of the myotomy, and the velocity of the RGC from 100 to 70 cm from the pylorus slowed (18.1 ± 3.0 to 9.0 ± 0.8 cm/sec) such that the RGC orad and aborad of the myotomy occurred simultaneously. After MNT, the RGC was unchanged up to 66 ± 6 cm from the pylorus, and the sequence of the RGC across the denervated intestine was unaltered. The velocity of the RGC from 100 to 70 cm from the pylorus increased from 12.8 ± 1.6 to 196 ± 116 cm/sec. After myotomy or MNT, the percent occurrence and magnitude of the RGC across the intestine 100 to 70 cm from the pylorus decreased. Conclusions The CNS activates the RGC 10 to 20 cm aborad of its innervation of the intestine and controls the RGC sequence. On the other hand, the ENS plays a role in initiation and generation of the RGC. PMID:26645249

Primary Retrograde Tibiotalocalcaneal Nailing For Fragility Ankle Fractures.

PubMed

Taylor, Benjamin C; Hansen, Dane C; Harrison, Ryan; Lucas, Douglas E; Degenova, Daniel

2016-01-01

Ankle fragility fractures are difficult to treat due to poor bone quality and soft tissues as well as the near ubiquitous presence of comorbidities including diabetes mellitus and peripheral neuropathy. Conventional open reduction and internal fixation in this population has been shown to lead to a significant rate of complications. Given the high rate of complications with contemporary fixation methods, the present study aims to critically evaluate the use of acute hindfoot nailing as a percutaneous fixation technique for high-risk ankle fragility fractures. In this study, we retrospectively evaluated 31 patients treated with primary retrograde tibiotalocalcaneal nail without joint preparation for a mean of 13.6 months postoperatively from an urban Level I trauma center during the years 2006-2012. Overall, there were two superficial infections (6.5%) and three deep infections (9.7%) in the series. There were 28 (90.3%) patients that went on to radiographic union at a mean of 22.2 weeks with maintenance of foot and ankle alignment. There were three cases of asymptomatic screw breakage observed at a mean of 18.3 months postoperatively, which were all treated conservatively.. This study shows that retrograde hindfoot nailing is an acceptable treatment option for treatment of ankle fragility fractures. Hindfoot nailing allows early weightbearing, limited soft tissue injury, and a relatively low rate of complications, all of which are advantages to conventional open reduction internal fixation techniques. Given these findings, larger prospective randomized trials comparing this treatment with conventional open reduction internal fixation techniques are warranted.

Primary Retrograde Tibiotalocalcaneal Nailing For Fragility Ankle Fractures

PubMed Central

Taylor, Benjamin C.; Hansen, Dane C.; Harrison, Ryan; Lucas, Douglas E; Degenova, Daniel

2016-01-01

Background Ankle fragility fractures are difficult to treat due to poor bone quality and soft tissues as well as the near ubiquitous presence of comorbidities including diabetes mellitus and peripheral neuropathy. Conventional open reduction and internal fixation in this population has been shown to lead to a significant rate of complications. Given the high rate of complications with contemporary fixation methods, the present study aims to critically evaluate the use of acute hindfoot nailing as a percutaneous fixation technique for high-risk ankle fragility fractures. Methods In this study, we retrospectively evaluated 31 patients treated with primary retrograde tibiotalocalcaneal nail without joint preparation for a mean of 13.6 months postoperatively from an urban Level I trauma center during the years 2006-2012. Results Overall, there were two superficial infections (6.5%) and three deep infections (9.7%) in the series. There were 28 (90.3%) patients that went on to radiographic union at a mean of 22.2 weeks with maintenance of foot and ankle alignment. There were three cases of asymptomatic screw breakage observed at a mean of 18.3 months postoperatively, which were all treated conservatively.. Conclusions This study shows that retrograde hindfoot nailing is an acceptable treatment option for treatment of ankle fragility fractures. Hindfoot nailing allows early weightbearing, limited soft tissue injury, and a relatively low rate of complications, all of which are advantages to conventional open reduction internal fixation techniques. Given these findings, larger prospective randomized trials comparing this treatment with conventional open reduction internal fixation techniques are warranted. PMID:27528840

A Novel, Modified Reverse Controlled Antegrade and Retrograde Subintimal Tracking Technique for Bypassing the Calcified Proximal Cap of Coronary Total Occlusions

PubMed Central

Ochiai, Masahiko; Munehisa, Masato; Ootomo, Tatsushi

2017-01-01

Antegrade crossing is the most common approach to chronic total occlusions (CTOs). However, it is sometimes difficult to penetrate the proximal hard cap with guidewires, especially in the case of CTOs of anomalous coronary arteries because of a lack of support. Herein, we describe a novel, modified reverse controlled antegrade and retrograde subintimal tracking (CART) technique in which the dissection reentry was intentionally created in the proximal segment of the vessel, not within the occluded segment, using retrograde guidewire and the aid of an antegrade balloon. This technique facilitated retrograde crossing of CTOs by avoiding the proximal hard cap and may provide a viable option for patients in which conventional reverse CART is not possible. PMID:28529807

Predicting the failure of retrograde ureteral stent insertion for managing malignant ureteral obstruction in outpatients

PubMed Central

WANG, JIN-YOU; ZHANG, HAI-LIANG; ZHU, YAO; QIN, XIAO-JIAN; DAI, BO; YE, DING-WEI

2016-01-01

Malignant ureteral obstruction (MUO) is an unpropitious sign that is commonly observed in patients with advanced incurable cancer. The present study aimed to evaluate predictive factors for the failure of retrograde ureteral stent insertion in the management of MUO in outpatients. A total of 164 patients with MUO were retrospectively assessed in this study. Clinical factors, including age, gender, type of malignancy, level of obstruction, cause of obstruction, pre-operative creatinine level, degree of hydronephrosis, condition of the contralateral ureter, prior radiotherapy, Eastern Cooperative Oncology Group performance status (ECOG PS), bladder wall invasion and technical failure, were recorded for each case. Univariate and multivariate logistic regression analyses were used to investigate the risk factors for predicting the failure of retrograde ureteral stent insertion. In total, 38 out of 164 patients experienced bilateral obstruction, therefore, a total of 202 ureteral units were available for data analysis. The rate of insertion failure in MUO was 34.65%. Multivariate analyses identified ECOG PS, degree of hydronephrosis and bladder wall invasion as independent predictors for insertion failure. Overall, the present study found that rate of retrograde ureteral stent insertion failure is high in outpatients with MUO, and that ECOG PS, degree of hydronephrosis and bladder invasion are potential independent predictors of insertion failure. PMID:26870299

Impact of local hydrothermal treatment during bread baking on soluble amylose, firmness, amylopectin retrogradation and water mobility during bread staling.

PubMed

Besbes, Emna; Le Bail, Alain; Seetharaman, Koushik

2016-01-01

The impact of hydrothermal processing undergone by bread dough during baking on the degree of starch granule disruption, on leaching of soluble amylose, on water mobility, on firmness and on amylopectin retrogradation during staling has been investigated. Two heating rates during baking have been considered (4.67 and 6.31 °C/min) corresponding respectively to baking temperature of 220 and 240 °C. An increase in firmness and in the amount of retrogradated amylopectin accompanied by a decrease in freezable water has been observed during staling. Although a lower heating rate yielded in larger amount of retrogradated amylopectin retrogradation, it resulted in a lower firmness. Additionally, the amount of soluble amylose and the relaxation times of water measured by Nuclear Magnetic Resonance NMR (T20, T21 and T22) decreased during staling. It was demonstrated that the amount of soluble amylose was higher for bread crumb baked at lower heating rate, indicating that an increasing amount of amylose is leached outside the starch granules. This was corresponding to a greater amount of retrograded amylopectin during staling. Moreover, it was found that the degree of gelatinization differs locally in a same bread slice between the top, the centre and the bottom locations in the crumb. This was attributed to the differences in kinetics of heating, the availability of water during baking and the degree of starch granule disruption during baking. Based on first order kinetic model, it was found that staling kinetics were faster for samples baked at higher heating rate.

WD60/FAP163 is a dynein intermediate chain required for retrograde intraflagellar transport in cilia

PubMed Central

Patel-King, Ramila S.; Gilberti, Renée M.; Hom, Erik F. Y.; King, Stephen M.

2013-01-01

Retrograde intraflagellar transport (IFT) is required for assembly of cilia. We identify a Chlamydomonas flagellar protein (flagellar-associated protein 163 [FAP163]) as being closely related to the D1bIC(FAP133) intermediate chain (IC) of the dynein that powers this movement. Biochemical analysis revealed that FAP163 is present in the flagellar matrix and is actively trafficked by IFT. Furthermore, FAP163 copurified with D1bIC(FAP133) and the LC8 dynein light chain, indicating that it is an integral component of the retrograde IFT dynein. To assess the functional role of FAP163, we generated an RNA interference knockdown of the orthologous protein (WD60) in planaria. The Smed-wd60(RNAi) animals had a severe ciliary assembly defect that dramatically compromised whole-organism motility. Most cilia were present as short stubs that had accumulated large quantities of IFT particle–like material between the doublet microtubules and the membrane. The few remaining approximately full-length cilia had a chaotic beat with a frequency reduced from 24 to ∼10 Hz. Thus WD60/FAP163 is a dynein IC that is absolutely required for retrograde IFT and ciliary assembly. PMID:23864713

Retrograde Transpedal Access for Revascularization of Below-the-Knee Arteries in Patients with Critical Limb Ischemia after an Unsuccessful Antegrade Transfemoral Approach.

PubMed

Goltz, J P; Planert, M; Horn, M; Wiedner, M; Kleemann, M; Barkhausen, J; Stahlberg, E

2016-10-01

To evaluate the safety and technical and clinical success of endovascular below-the-knee (BTK) artery revascularization by a retrograde transpedal access. We retrospectively identified 16/172 patients (9.3 %) with endovascular BTK revascularization in whom a transfemoral approach had failed and transpedal access had been attempted. The dorsal pedal (n = 13) or posterior tibial (n = 3) artery was accessed using a dedicated access set and ultrasound guidance. The procedure was finished in antegrade fashion by plain old balloon angioplasty (POBA). Comorbidities, vessel diameter and calcification at the access site were recorded. The analyzed outcomes were technical success, procedural complications, procedure time, crossing (guidewire beyond lesion and intra-luminal) and procedural (residual stenosis < 30 % after POBA) success, and limb salvage. Diabetes, coronary artery disease and hypertension were present in 15 patients (93.8 %), and both renal impairment and previous amputations in 7 (43.8 %). Pedal access vessel calcification was present in 5/16 patients (31.3 %). The mean diameter was 1.75 +/-0.24 mm. The procedure time was 92.4 +/-23 min. The success rate for achieving retrograde access was 100 %. Retrograde crossing was successful in 12/16 patients (75.0 %). Procedural success was observed in 10/16 patients (68.8 %). Minor complications occurred in 2/16 patients (12.5 %). The rate of limb salvage was 72.9 %, and the overall survival was 100 % at 12 months. Major amputations after revascularization occurred in 2/16 patients (12.5 %). If an antegrade transfemoral approach to BTK lesions fails, a retrograde transpedal approach may nevertheless facilitate treatment. This approach appears to be safe and offers high technical and acceptable clinical success rates. • Retrograde approaches via transpedal or transtibial vessels are safe and offer high technical success.• One problem after technically successful puncture

Endoscope disinfection and its pitfalls--requirement for retrograde surveillance cultures.

PubMed

Buss, A J; Been, M H; Borgers, R P; Stokroos, I; Melchers, W J; Peters, F T; Limburg, A J; Degener, J E

2008-04-01

Several endoscopy-related outbreaks of infection have been reported in recent years. For early recognition of inadequate disinfection of endoscopes we designed a microbiological surveillance system to evaluate the efficacy of the cleaning and disinfection procedure, and to trace disinfection problems to individual endoscopes or washer-disinfectors. Our surveillance protocol included anterograde and retrograde sampling, a decision algorithm, genetic fingerprinting, and scanning electron microscopy. Over a period of 29 months we found an increasing number of patient-ready endoscopes testing positive for Candida species other than albicans, especially C. parapsilosis. These yeasts were also isolated from the washer-disinfectors. The number of positive tests for Candida species varied from 1 out of 21 to 14 out of 27 samples from nine frequently used endoscopes. The number of colony-forming units per milliliter ranged from 1 - 10 to 3000 for endoscopes and 0.002 to 0.06 for the washer disinfectors. DNA fingerprinting was not able to discriminate different strains within C. parapsilosis. Our protocol was able to detect a structural problem in the endoscope disinfection process. Retrograde sampling was crucial for this purpose, because it has much higher sensitivity than anterograde sampling. Endoscopes with damaged working channels are probably the source of the contamination problem with Candida species.

Rab9-dependent retrograde transport and endosomal sorting of the endopeptidase furin

PubMed Central

Chia, Pei Zhi Cheryl; Gasnereau, Isabelle; Lieu, Zi Zhao; Gleeson, Paul A.

2011-01-01

The endopeptidase furin and the trans-Golgi network protein TGN38 are membrane proteins that recycle between the TGN and plasma membrane. TGN38 is transported by a retromer-dependent pathway from early endosomes to the TGN, whereas the intracellular transport of furin is poorly defined. Here we have identified the itinerary and transport requirements of furin. Using internalisation assays, we show that furin transits the early and late endosomes en route to the TGN. The GTPase Rab9 and the TGN golgin GCC185, components of the late endosome-to-TGN pathway, were required for efficient TGN retrieval of furin. By contrast, TGN38 trafficking was independent of Rab9 and GCC185. To identify the sorting signals for the early endosome-to-TGN pathway, the trafficking of furin–TGN38 chimeras was investigated. The diversion of furin from the Rab9-dependent late-endosome-to-TGN pathway to the retromer-dependent early-endosome-to-TGN pathway required both the transmembrane domain and cytoplasmic tail of TGN38. We present evidence to suggest that the length of the transmembrane domain is a contributing factor in endosomal sorting. Overall, these data show that furin uses the Rab9-dependent pathway from late endosomes and that retrograde transport directly from early endosomes is dependent on both the transmembrane domain and the cytoplasmic tail. PMID:21693586

Application of a snare technique in retrograde chronic total occlusion percutaneous coronary intervention – a step by step practical approach and an observational study

PubMed Central

Fang, Hsiu-Yu; Lee, Wei-Chieh; Fang, Chih-Yuan; Wu, Chiung-Jen

2016-01-01

Abstract Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has recently become popular among interventional cardiologists. CTO originating from the ostium has been one of the most difficult CTO lesions to treat with PCI for a number of reasons. Our aim was to illustrate a specific technique during retrograde CTO PCI referred to as the “snare technique.” We retrospectively examined the use of “snare technique” among 371 consecutive retrograde CTO PCIs performed at our institution between 2006 and 2015. “Snare technique” was used in 10 patients among the 371 retrograde CTO PCIs. The baseline clinical and angiographic characteristics of patients with or without “snare technique” were similar. The “snare technique” group had significantly fewer side branches at occlusion (30.0% vs 71.2%, P = 0.01) and a higher incidence of externalization (90% vs 25.5%, P < 0.001). The contrast volume was significantly lower in the “snare technique” group (285.0 ± 68.5 vs 379.2 ± 144.0, P = 0.04). The incidence of major complications, retrograde success, or final success did not differ between the groups. The “snare technique” is safe and feasible in retrograde CTO PCI, especially in cases of difficult coronary engagement in cases such as ostial occlusion, challenging coronary anatomy, or retrograde guidewire cannot get in antegrade guiding catheter. PMID:27741138

Modality-specific occult intrarenal pseudoaneurysm in a renal allograft and the legacy of catheter angiography.

PubMed

Rastogi, Neeraj; Williams, Gethin; Alencar, Herlen

2013-11-01

A 69-year-old man with history of end-stage-renal disease (ESRD) underwent successful kidney transplantation from a cadaveric donor in November 2011. However, posttransplant recovery was complicated by delayed graft function and recurrent gross hematuria. Serial Doppler ultrasound (US) of the renal allograft demonstrated a pseudoaneurysm with interval increase in size. However, it could not be visualized with other modalities, including an initial angiogram (postoperative day 49) and a second angiogram (postoperative day 68), followed by surgical exploration (postoperative day 71), which demonstrated complete intra-aneurysmal thrombosis on intraoperative Doppler US. Unfortunately, the patient's hematuria continued and a repeat Doppler US 48 hours later demonstrated a persistent pseudoaneurysm. Therefore, on postoperative day 75, we performed targeted percutaneous intra-aneurysmal thrombin injection under dual image guidance, which showed complete intra-aneurysmal thrombosis on intraprocedural Doppler US. Hematuria recurred the next day. A third angiogram (postoperative day 77) finally illuminated the hidden pseudoaneurysm occult on the first and second angiographic studies (sensitivity [index case] 33%) and surgery. This allowed for successful coil embolization of a subsegmental feeding branch with an excellent outcome. We support a more aggressive management with serial angiography and embolization of the intrarenal symptomatic pseudoaneurysm rather than surgery in renal allograft recipients, with the benefits outweighing the risks. Copyright © 2013 Elsevier Inc. All rights reserved.

Nitroprusside and ECS-induced retrograde amnesia.

PubMed

Sudha, S; Andrade, C; Anand, A; Guido, S; Venkataraman, B V

2001-03-01

Previous research found that the administration of verapamil and felodipine immediately before electroconvulsive shocks (ECS) attenuated ECS-induced retrograde amnesia. This study examined whether sodium nitroprusside, an antihypertensive drug that does not affect calcium channels, has a similar action. Adult male Sprague-Dawley rats received nitroprusside (0.5 mg/kg ip) or saline 3 minutes before each of three once-daily true or sham ECS. Retention of pre-ECS learning was studied 1 day after ECS using a passive avoidance task. Nitroprusside was associated with increased seizure duration in ECS-treated rats, and with enhanced recall in both true and sham ECS groups. The latter finding suggests that nitroprusside nonspecifically improves cognitive functions, and does not support the hypothesis that ECS-induced cognitive impairment is a result of blood-brain barrier breach. Nitric oxide mechanisms may underlie the benefits purveyed by nitroprusside.

Antegrade rewiring of the retrograde Corsair catheter during revascularization of chronic total coronary occlusions: a simple alternative to guidewire exteriorization.

PubMed

Haworth, P A J; Hildick-Smith, D

2014-08-01

Chronic total occlusions prevent a significant challenge to interventional cardiologists. Successful opening of chronically occluded vessels has been shown to be associated with decreased mortality and morbidity. Recently, the retrograde approach to chronic total occlusion intervention has been developed. In this case series, we present a novel technique to assist with this procedure involving antegrade wiring of a retrograde microcatheter. © 2011 Wiley Periodicals, Inc., a Wiley company.

Retrograde Instillation of Methylene Blue in the Difficult Diagnosis of BPF

PubMed Central

Ravenna, F.; Feo, C.; Calia, N.; Avoscan, C.; Barbetta, C.; Cavallesco, G. N.

2012-01-01

We report two cases in which we were able to diagnose bronchopleural fistula through retrograde methylene blue instillation during bronchoscopy. In the first case, methylene blue was injected through an abdominal drain, followed by air instillation and detected in the left bronchial tree, demonstrating the presence of a fistula in the lingula's bronchus. In the second case, methylene blue was injected into a pleural drain, through a breach on a surgical suture and detected in the right bronchial tree, demonstrating the presence of a fistula in the right inferior bronchus. The retrograde instillation of methylene blue, through a drain in the abdomen or the thoracic wall, is a safe, cheap, and practical method that allows the bronchoscopist to identify the presence of a fistula and, more importantly, to identify the exact point on the bronchial tree where a fistula is located. This provides the possibility of sealing the fistula with a variety of devices. It is our opinion that this procedure should be considered a primary method of diagnosis when a bronchopleural fistula is suspected and a drain on the thoracic or abdominal wall is positioned such that effusions are able to drain. PMID:23091498

Retrograde Instillation of Methylene Blue in the Difficult Diagnosis of BPF.

PubMed

Ravenna, F; Feo, C; Calia, N; Avoscan, C; Barbetta, C; Cavallesco, G N

2012-01-01

We report two cases in which we were able to diagnose bronchopleural fistula through retrograde methylene blue instillation during bronchoscopy. In the first case, methylene blue was injected through an abdominal drain, followed by air instillation and detected in the left bronchial tree, demonstrating the presence of a fistula in the lingula's bronchus. In the second case, methylene blue was injected into a pleural drain, through a breach on a surgical suture and detected in the right bronchial tree, demonstrating the presence of a fistula in the right inferior bronchus. The retrograde instillation of methylene blue, through a drain in the abdomen or the thoracic wall, is a safe, cheap, and practical method that allows the bronchoscopist to identify the presence of a fistula and, more importantly, to identify the exact point on the bronchial tree where a fistula is located. This provides the possibility of sealing the fistula with a variety of devices. It is our opinion that this procedure should be considered a primary method of diagnosis when a bronchopleural fistula is suspected and a drain on the thoracic or abdominal wall is positioned such that effusions are able to drain.

The golgin protein Coy1 functions in intra-Golgi retrograde transport and interacts with the COG complex and Golgi SNAREs

PubMed Central

Anderson, Nadine S.; Mukherjee, Indrani; Bentivoglio, Christine M.; Barlowe, Charles

2017-01-01

Extended coiled-coil proteins of the golgin family play prominent roles in maintaining the structure and function of the Golgi complex. Here we further investigate the golgin protein Coy1 and document its function in retrograde transport between early Golgi compartments. Cells that lack Coy1 displayed a reduced half-life of the Och1 mannosyltransferase, an established cargo of intra-Golgi retrograde transport. Combining the coy1Δ mutation with deletions in other putative retrograde golgins (sgm1Δ and rud3Δ) caused strong glycosylation and growth defects and reduced membrane association of the conserved oligomeric Golgi (COG) complex. In contrast, overexpression of COY1 inhibited the growth of mutant strains deficient in fusion activity at the Golgi (sed5-1 and sly1-ts). To map Coy1 protein interactions, coimmunoprecipitation experiments revealed an association with the COG complex and with intra-Golgi SNARE proteins. These physical interactions are direct, as Coy1 was efficiently captured in vitro by Lobe A of the COG complex and the purified SNARE proteins Gos1, Sed5, and Sft1. Thus our genetic, in vivo, and biochemical data indicate a role for Coy1 in regulating COG complex-dependent fusion of retrograde-directed COPI vesicles. PMID:28794270

Right medial thalamic lesion causes isolated retrograde amnesia.

PubMed

Miller, L A; Caine, D; Harding, A; Thompson, E J; Large, M; Watson, J D

2001-01-01

Pervasive retrograde amnesia without anterograde memory impairment has rarely been described as a consequence of circumscribed brain damage. We report this phenomenon in a 33 yr-old, right-handed man (JG) in association with the extension in the right thalamus of a previously small, bilateral thalamic lesion. JG presented with a dense amnesia for autobiographical material more than a few years old, with some sparing of recent memories. Furthermore, he was completely unable to recognise famous people or world events. Many other aspects of semantic knowledge were intact and there was no evidence of general intellectual impairment, executive dysfunction or loss of visual imagery. Magnetic resonance imaging revealed an acute lesion in the right thalamus and two small, symmetrical, bilateral non-acute thalamic lesions. Follow-up neuropsychological assessment indicated a stable pattern of impaired retrograde and spared anterograde memory over 18 months and psychiatric assessments yielded no evidence of confabulation, malingering or other symptoms to suggest psychogenic amnesia. JG's profile indicates that the division of declarative memory into just two categories - episodic and semantic - is inadequate. Rather, his case adds to the growing body evidence to suggest that world knowledge pertaining to people and events is stored or accessed similarly to autobiographical information and differently from other types of more general factual knowledge. We hypothesize that the right mediodorsal thalamic nucleus and immediately surrounding regions comprise the central processing mechanism referred to by McClelland (Revue Neurologique, 150 (1994) 570) and Markowitsch (Brain Research Review, 21 (1995) 117) as responsible for inducing and co-ordinating the recall of these sorts of cortically stored memory engrams.

Changes in the HOAr isotope composition of clays during retrograde alteration

USGS Publications Warehouse

Wilson, M.R.; Kyser, T.K.; Mehnert, H.H.; Hoeve, J.

1987-01-01

K-Ar ages of illite alteration associated with Middle Proterozoic Athabasca unconformity-type U deposits in Saskatchewan range from 414 to 1493 Ma. The K-Ar ages correlate with water contents and ??D values such that illites with young K-Ar ages have ??D values as low as -169 and water contents as high as 7.7 wt.% whereas illites with older ages have ??D values near -70 and water contents near 4 wt.%. Water extracted at 400??C from illites with low ??D values and high water contents has low ??D and ??18O values similar to those of modern meteoric water suggesting that some of the illites associated with the original deposition of the ore underwent varying degrees of retrograde alteration. The alteration is initiated by hydration of sites in the interlayer region of the illite which results in the partial resetting of the K-Ar ages and introduction of excess structural water in the form of interlamellar water. The interlamellar water is enriched in 18O by about 7 per mil relative to the water that physically surrounded the clay particle. Further alteration decreases the ??D value and increases the ??18O value of the illite by isotopic exchange between the mineral and the interlamellar water. Although the chemical compositions and XRD patterns of the altered illites indicate that no detectable smectite component is present in the samples, the isotopic results suggest that the altered illites may be an early precursor in the formation of mixed-layer illite/smectite by retrograde alteration of pure illite. The wide variation of ??D values of chlorite and kaolinite from these U deposits is analogous to that of the illite suggesting that retrograde alteration of clays by meteoric water can be substantial. The general association of altered clays with areas containing the highest concentrations of U is probably related to localized permeability within the ore zone. ?? 1987.

Radiographic predictors of symptomatic screw removal after retrograde femoral nail insertion.

PubMed

Hamaker, Max; O'Hara, Nathan N; Eglseder, W Andrew; Sciadini, Marcus F; Nascone, Jason W; O'Toole, Robert V

2017-03-01

Removal of symptomatic implants is a common procedure performed by orthopaedic trauma surgeons. No guidance is available regarding which factors contribute to the likelihood of an implant becoming symptomatic. Our objective was to determine whether radiographic parameters associated with distal interlocks in retrograde femoral nails are associated with the rate of symptomatic screw removal. We conducted a retrospective review at a Level I trauma center. Study patients (n=442) had femoral fractures treated with retrograde intramedullary nails from 2007 to 2014 and at least 1year of follow-up. The main outcome measurement was symptomatic distal screw removal as predicted by radiographic parameters. Symptomatic screw removal occurred in 12% of the patients. Increased distance between the most distal screw and the articular surface of the femur significantly reduced likelihood of symptomatic screw removal. A cutoff of 40mm from the articular block was predictive of removal (≥40mm, 0% removal; <40mm, 18% removal, p<0.0001). In patients with distal screws placed within 40mm of the articular surface of the femur, a ratio of screw length to distance between medial and lateral femoral cortices that was ≥1 was a strong predictor of symptomatic screw removal (area under Receiver Operating Characteristic curve, 0.75; p<0.0001). More distal screws and screws that radiographically extend to or beyond the medial cortex are more likely to cause pain and require removal in femoral fractures treated with retrograde intramedullary nails. We identified a specific distance from the joint (<40mm) and a ratio of screw length to bone width (≥1) that significantly increased the likelihood of symptomatic screw removal. Clinicians can use these data to inform patients of the likely risk of implant removal and perhaps to better guide placement and length of screws when the clinical scenario allows some flexibility in location and length of screws. Copyright © 2017 Elsevier Ltd. All

Acute Fasting Regulates Retrograde Synaptic Enhancement through a 4E-BP-Dependent Mechanism.

PubMed

Kauwe, Grant; Tsurudome, Kazuya; Penney, Jay; Mori, Megumi; Gray, Lindsay; Calderon, Mario R; Elazouzzi, Fatima; Chicoine, Nicole; Sonenberg, Nahum; Haghighi, A Pejmun

2016-12-21

While beneficial effects of fasting on organismal function and health are well appreciated, we know little about the molecular details of how fasting influences synaptic function and plasticity. Our genetic and electrophysiological experiments demonstrate that acute fasting blocks retrograde synaptic enhancement that is normally triggered as a result of reduction in postsynaptic receptor function at the Drosophila larval neuromuscular junction (NMJ). This negative regulation critically depends on transcriptional enhancement of eukaryotic initiation factor 4E binding protein (4E-BP) under the control of the transcription factor Forkhead box O (Foxo). Furthermore, our findings indicate that postsynaptic 4E-BP exerts a constitutive negative input, which is counteracted by a positive regulatory input from the Target of Rapamycin (TOR). This combinatorial retrograde signaling plays a key role in regulating synaptic strength. Our results provide a mechanistic insight into how cellular stress and nutritional scarcity could acutely influence synaptic homeostasis and functional stability in neural circuits. Copyright © 2016 Elsevier Inc. All rights reserved.

Relative importance of moisture migration and amylopectin retrogradation for pound cake crumb firming.

PubMed

Luyts, A; Wilderjans, E; Van Haesendonck, I; Brijs, K; Courtin, C M; Delcour, J A

2013-12-15

Moisture migration largely impacts cake crumb firmness during storage at ambient temperature. To study the importance of phenomena other than crumb to crust moisture migration and to exclude moisture and temperature gradients during baking, crustless cakes were baked using an electrical resistance oven (ERO). Cake crumb firming was evaluated by texture analysis. First, ERO cakes with properties similar to those baked conventionally were produced. Cake batter moisture content (MC) was adjusted to ensure complete starch gelatinisation in the baking process. In cakes baked conventionally, most of the increase in crumb firmness during storage was caused by moisture migration. Proton nuclear magnetic resonance ((1)H NMR) showed that the population containing protons of crystalline starch grew during cake storage. These and differential scanning calorimetry (DSC) data pointed to only limited amylopectin retrogradation. The limited increase in amylopectin retrogradation during cake storage cannot solely account for the significant firming of ERO cakes and, hence, other phenomena are involved in cake firming. Copyright © 2013 Elsevier Ltd. All rights reserved.

Rabies Virus Envelope Glycoprotein Targets Lentiviral Vectors to the Axonal Retrograde Pathway in Motor Neurons*

PubMed Central

Hislop, James N.; Islam, Tarin A.; Eleftheriadou, Ioanna; Carpentier, David C. J.; Trabalza, Antonio; Parkinson, Michael; Schiavo, Giampietro; Mazarakis, Nicholas D.

2014-01-01

Rabies pseudotyped lentiviral vectors have great potential in gene therapy, not least because of their ability to transduce neurons following their distal axonal application. However, very little is known about the molecular processes that underlie their retrograde transport and cell transduction. Using multiple labeling techniques and confocal microscopy, we demonstrated that pseudotyping with rabies virus envelope glycoprotein (RV-G) enabled the axonal retrograde transport of two distinct subtypes of lentiviral vector in motor neuron cultures. Analysis of this process revealed that these vectors trafficked through Rab5-positive endosomes and accumulated within a non-acidic Rab7 compartment. RV-G pseudotyped vectors were co-transported with both the tetanus neurotoxin-binding fragment and the membrane proteins thought to mediate rabies virus endocytosis (neural cell adhesion molecule, nicotinic acetylcholine receptor, and p75 neurotrophin receptor), thus demonstrating that pseudotyping with RV-G targets lentiviral vectors for transport along the same pathway exploited by several toxins and viruses. Using motor neurons cultured in compartmentalized chambers, we demonstrated that axonal retrograde transport of these vectors was rapid and efficient; however, it was not able to transduce the targeted neurons efficiently, suggesting that impairment in processes occurring after arrival of the viral vector in the soma is responsible for the low transduction efficiency seen in vivo, which suggests a novel area for improvement of gene therapy vectors. PMID:24753246

Ruptured Pseudoaneurysm of the Lateral Plantar Artery After Tibiotalocalcaneal Fusion With Retrograde Nail-A Rare Complication.

PubMed

Sundararajan, Silvampatti Ramaswamy; Rajagopalakrishnan, Ramakanth; Rajasekaran, Shanmuganathan

We report a rare presentation of a ruptured pseudoaneurysm of the lateral plantar artery following tibiotalocalcaneal fusion with a retrograde nail at 1 month after the index surgery. Although case reports of pseudoaneurysms of larger arteries such as the anterior tibial artery and posterior tibial artery after ankle surgery (e.g., ankle arthroscopy, implant removal, Ilizarov application) have been reported, we report a rare complication of a pseudoaneurysm of the lateral plantar artery. We discuss the anatomic considerations of the lateral plantar artery in the foot and the entry point of the retrograde nail to avoid this unusual complication. Copyright © 2017 The American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Comparison of knee function in patients with a healed fracture of the femoral shaft fixed with retrograde and antegrade intramedullary nailing.

PubMed

Andrzejewski, Krzysztof; Panasiuk, Michał; Grzegorzewski, Andrzej; Synder, Marek

2013-10-31

BACKGROUND. Despite extensive current knowledge about fractures of the femoral shaft, the choice between antegrade and retrograde intramedullary (IM) nailing with respect to the future function of the joint serving to introduce the nail continues to raise controversy. To compare knee function in patients with a healed fracture of the femoral shaft fixed by antegrade vs. retrograde IM nailing. MATERIAL AND METHODS. The study involved a group of 65 individuals with traumatic fractures of the femoral shaft who underwent stabilisation with IM nails in the years 2001-2010. Thirty-two cases were retrograde nails (Group R) and 33 antegrade nails (Group A). Patient age at trauma ranged from 19 to 91 years (mean: 47). Knee function was assessed in both groups with the KOOS, KSS1 and KSS2 scoring systems. RESULTS. Knee function as assessed with KOOS differed significantly between retrograde and antegrade nailing, with a greater incidence of poor and fair results in the former and more excellent outcomes in the latter group (p=0.0133). As regards KSS1 and KSS2, there were no significant differences between the groups (p=0.1947, p=0.4038). The range of motion was 86-125 degrees in Group R and 121-125 degrees in Group A. Knee pain was reported by 37.5% of the patients treated with retrograde nailing and 39.4% of those who had the IM nail inserted via the antegrade approach (p=0.22). The mean time to bone union was 180 days in Group R and 219 days in Group A (p=0.25). Age and presence of osteoarthritis at trauma significantly lowered the KOOS (p=0.0027, p= 0.005) and KSS (p=0.0002, p=0.002) scores, as well as the knee range of motion (p=0.0014, p=0.004) CONCLUSIONS. 1. Knee function following retrograde and antegrade IM nailing to stabilise femoral shaft fractures was comparable. 2. The choice of IM nailing method should not be based solely on orthopaedic indications, but also on the severity of osteoarthritis present at trauma.

Temporary Vascular Occlusion by Rapid Reverse Phase Polymer: A Preliminary In Vitro Study of Retrograde Injection

PubMed Central

Dregelid, Einar

2012-01-01

During vascular surgical operations, there is a need for a simpler and more reliable method of temporary arterial occlusion than those currently employed, especially of heavily calcified arteries. A thermosensitive polymer, LeGoo (LG) (Pluromed, Woburn, MA), has been used successfully for temporary vascular occlusion. It has hitherto been injected by a cannula that has been introduced into the artery to be occluded, here henceforth called the “cannulation method.” Injection into arterial ostia without cannulation, using an injection device that arrests blood flow during the injection, here henceforth called “a retrograde method” may enable temporary hemostasis when ostial stenoses render it impossible to inject LG using the cannulation method. The objective of the present study was to study the feasibility of a retrograde method and to compare it with the cannulation method in an in vitro model, incorporating a narrow orifice to simulate ostial stenosis, using tap water at 37°C instead of blood. The retrograde method of LG injection, using a modified paediatric Foley catheter, turned out to be feasible to produce a durable LG plug more reliably, at higher water pressure and with less deep LG injection than with the cannulation method. PMID:22888352

Uncontrolled diabetes as a potential risk factor in tibiotalocalcaneal fusion using a retrograde intramedullary nail.

PubMed

Lee, Moses; Choi, Woo Jin; Han, Seung Hwan; Jang, Jinyoung; Lee, Jin Woo

2017-07-22

Tibiotalocalcaneal (TTC) fusion using a retrograde intramedullary (IM) nail is an effective salvage option for terminal-stage hindfoot problems. However, as many patients who receive TTC fusion bear unfavorable medical comorbidities, the risk of nonunion, infection and other complications increases. This study was performed to identify the factors influencing outcomes after TTC fusion using a retrograde IM nail. Between September 2008 and February 2012, 34 consecutive patients received TTC fusion using a retrograde IM nail for limb salvage. All patients had a minimum follow-up of two years. Throughout follow-up, standard ankle radiography was performed along with clinical outcome assessment using a visual analog scale (VAS) for pain, the American Orthopaedic Foot and Ankle Society Ankle-Hind Foot Scale (AOFAS A/H scale) and the Foot and Ankle Outcome Score (FAOS). For the retrospective analysis, demographic factors, preoperative medical status, laboratory markers, and etiology were comprehensively reviewed using medical records. The success of the index operation was determined using clinical and radiological outcomes. Finally, the effect of each factor on failure after the operation was analyzed using univariate logistic regression. In a mean of seven months, 82% (28/34) achieved union, as evaluated by standard radiography. All clinical outcome parameters improved significantly after the operation, including VAS, AOFAS A/H scale, and FAOS (P<0.001). At the last follow-up, five cases of nonunion with less than AOFAS A/H scale of 80 and two cases of below knee amputation due to uncontrolled infection were determined to be failures. None of the factors (etiology, demographics, laboratory markers and medical status) significantly influenced failures. However, uncontrolled DM significantly increased the failure rate with an odds ratio of 10 (P=0.029). TTC fusion with a retrograde intramedullary nail is a successful treatment for complicated hindfoot problems such as

Discovery of New Retrograde Substructures: The Shards of ω Centauri?

NASA Astrophysics Data System (ADS)

Myeong, G. C.; Evans, N. W.; Belokurov, V.; Sanders, J. L.; Koposov, S. E.

2018-06-01

We use the SDSS-Gaia catalogue to search for substructure in the stellar halo. The sample comprises 62 133 halo stars with full phase space coordinates and extends out to heliocentric distances of ˜10 kpc. As actions are conserved under slow changes of the potential, they permit identification of groups of stars with a common accretion history. We devise a method to identify halo substructures based on their clustering in action space, using metallicity as a secondary check. This is validated against smooth models and numerical constructed stellar halos from the Aquarius simulations. We identify 21 substructures in the SDSS-Gaia catalogue, including 7 high significance, high energy and retrograde ones. We investigate whether the retrograde substructures may be material stripped off the atypical globular cluster ω Centauri. Using a simple model of the accretion of the progenitor of the ω Centauri, we tentatively argue for the possible association of up to 5 of our new substructures (labelled Rg1, Rg3, Rg4, Rg6 and Rg7) with this event. This sets a minimum mass of 5× 108M⊙ for the progenitor, so as to bring ω Centauri to its current location in action - energy space. Our proposal can be tested by high resolution spectroscopy of the candidates to look for the unusual abundance patterns possessed by ω Centauri stars.

Intrarenal urea recycling leads to a higher rate of renal excretion of potassium: an hypothesis with clinical implications.

PubMed

Kamel, Kamel S; Halperin, Mitchell L

2011-09-01

This review aims to illustrate why urea recycling may play an important role in potassium (K⁺) excretion and to emphasize its potential clinical implications. A quantitative analysis of the process of intrarenal urea recycling reveals that the amount of urea delivered to the distal convoluted tubule is about two-fold larger than the quantity of urea excreted in the urine. As the number of osmoles delivered to the late cortical distal nephron (CCD) determines its flow rate when aquaporin 2 water channels have been inserted in the luminal membrane of principal cells, urea recycling may play an important role in regulating the rate of excretion of K⁺ when the distal delivery of electrolytes is not very high. Urea recycling aids the excretion of K⁺; this is especially important in patients with disorders or those who are taking drugs that lead to a less lumen-negative voltage in the CCD. As a large quantity of urea is reabsorbed daily in the inner medullary collecting duct, the assumption made in the calculation of the transtubular K concentration gradient that there is no appreciable reabsorption of osmoles downstream CCD is not valid.

Retrograde Ascending Aortic Dissection after Stent Grafting for Stanford Type B Aortic Dissection with Severe Limb Ischemia.

PubMed

Higuchi, Yoshiro; Tochii, Masato; Takami, Yoshiyuki; Kobayashi, Akihiro; Yanagisawa, Tsutomu; Amano, Kentaro; Sakurai, Yusuke; Ishida, Michiko; Ishikawa, Hiroshi; Hattori, Koji; Takagi, Yasushi

2017-03-24

We report a rare case of retrograde Stanford type A aortic dissection after endovascular repair for complicated Stanford type B aortic dissection. A 45-year-old man presented with a sudden onset of back pain and was transferred to our hospital. Computed tomography demonstrated acute Stanford type B aortic dissection with lower limb ischemia. Emergency endovascular surgery was planned for repair of the Stanford type B aortic dissection. The patient suddenly developed recurrent chest pain 10 days after the initial procedure. Computed tomography revealed retrograde Stanford type A aortic dissection involving the ascending aorta and aortic arch. The patient underwent a successful emergency total aortic arch replacement.

Features of cues and processes during chloroplast-mediated retrograde signaling in the alga Chlamydomonas

USDA-ARS?s Scientific Manuscript database

Retrograde signalling is a selective process defined by cues generated in chloroplast/mitochondria which traverse membranes and end up regulating nuclear gene expression and protein synthesis. The coding and encoding of organellar message(s) that alter nuclear gene expression and/or cellular metabo...

D-(/sup 3/H)aspartate retrograde labelling of callosal and association neurons of somatosensory areas I and II of cats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barbaresi, P.; Fabri, M.; Conti, F.

Experiments were carried out on cats to ascertain whether corticocortical neurons of somatosensory areas I (SI) and II (SII) could be labelled by retrograde axonal transport of D-(/sup 3/H)aspartate (D-(/sup 3/H)Asp). This tritiated enantiomer of the amino acid aspartate is (1) taken up selectively by axon terminals of neurons releasing aspartate and/or glutamate as excitatory neurotransmitter, (2) retrogradely transported and accumulated in perikarya, (3) not metabolized, and (4) visualized by autoradiography. A solution of D-(/sup 3/H)Asp was injected in eight cats in the trunk and forelimb zones of SI (two cats) or in the forelimb zone of SII (six cats).more » In order to compare the labelling patterns obtained with D-(/sup 3/H)Asp with those resulting after injection of a nonselective neuronal tracer, horseradish peroxidase (HRP) was delivered mixed with the radioactive tracer in seven of the eight cats. Furthermore, six additional animals received HRP injections in SI (three cats; trunk and forelimb zones) or SII (three cats; forelimb zone). D-(/sup 3/H)Asp retrograde labelling of perikarya was absent from the ipsilateral thalamus of all cats injected with the radioactive tracer but a dense terminal plexus of anterogradely labelled corticothalamic fibers from SI and SII was observed, overlapping the distribution area of thalamocortical neurons retrogradely labelled with HRP from the same areas. D-(/sup 3/H)Asp-labelled neurones were present in ipsilateral SII (SII-SI association neurones) in cats injected in SI. In these animals a bundle of radioactive fibres was observed in the rostral portion of the corpus callosum entering the contralateral hemisphere. There, neurones retrogradely labelled with silver grains were present in SI (SI-SI callosal neurons).« less

Inorganic phosphate deprivation causes tRNA nuclear accumulation via retrograde transport in Saccharomyces cerevisiae.

PubMed

Hurto, Rebecca L; Tong, Amy Hin Yan; Boone, Charles; Hopper, Anita K

2007-06-01

Nuclear export of tRNA is an essential eukaryotic function, yet the one known yeast tRNA nuclear exporter, Los1, is nonessential. Moreover recent studies have shown that tRNAs can move retrograde from the cytosol to the nucleus by an undefined process. Therefore, additional gene products involved in tRNA nucleus-cytosol dynamics have yet to be identified. Synthetic genetic array (SGA) analysis was employed to identify proteins involved in Los1-independent tRNA transport and in regulating tRNA nucleus-cytosol distribution. These studies uncovered synthetic interactions between los1Delta and pho88Delta involved in inorganic phopsphate uptake. Further analysis revealed that inorganic phosphate deprivation causes transient, temperature-dependent nuclear accumulation of mature cytoplasmic tRNA within nuclei via a Mtr10- and retrograde-dependent pathway, providing a novel connection between tRNA subcellular dynamics and phosphate availability.

Inorganic Phosphate Deprivation Causes tRNA Nuclear Accumulation via Retrograde Transport in Saccharomyces cerevisiae

PubMed Central

Hurto, Rebecca L.; Tong, Amy Hin Yan; Boone, Charles; Hopper, Anita K.

2007-01-01

Nuclear export of tRNA is an essential eukaryotic function, yet the one known yeast tRNA nuclear exporter, Los1, is nonessential. Moreover recent studies have shown that tRNAs can move retrograde from the cytosol to the nucleus by an undefined process. Therefore, additional gene products involved in tRNA nucleus–cytosol dynamics have yet to be identified. Synthetic genetic array (SGA) analysis was employed to identify proteins involved in Los1-independent tRNA transport and in regulating tRNA nucleus–cytosol distribution. These studies uncovered synthetic interactions between los1Δ and pho88Δ involved in inorganic phopshate uptake. Further analysis revealed that inorganic phosphate deprivation causes transient, temperature-dependent nuclear accumulation of mature cytoplasmic tRNA within nuclei via a Mtr10- and retrograde-dependent pathway, providing a novel connection between tRNA subcellular dynamics and phosphate availability. PMID:17409072

Septic Complication After Balloon-Occluded Retrograde Transvenous Obliteration of Duodenal Variceal Bleeding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akasaka, Thai; Shibata, Toshiya, E-mail: ksj@kuhp.kyoto-u.ac.jp; Isoda, Hiroyoshi

2010-12-15

We report a 64-year-old woman with duodenal varices who underwent balloon-occluded retrograde transvenous obliteration (B-RTO) complicated by intraprocedural variceal rupture. The patient developed shivering and a fever higher than 40{sup o}C 3 days after the B-RTO procedure. A blood culture grew Entereobacter cloacoe. This case represents a rare septic complication of B-RTO for duodenal varices.

Deficiency in the Lipid Exporter ABCA1 Impairs Retrograde Sterol Movement and Disrupts Sterol Sensing at the Endoplasmic Reticulum*♦

PubMed Central

Yamauchi, Yoshio; Iwamoto, Noriyuki; Rogers, Maximillian A.; Abe-Dohmae, Sumiko; Fujimoto, Toyoshi; Chang, Catherine C. Y.; Ishigami, Masato; Kishimoto, Takuma; Kobayashi, Toshihide; Ueda, Kazumitsu; Furukawa, Koichi; Chang, Ta-Yuan; Yokoyama, Shinji

2015-01-01

Cellular cholesterol homeostasis involves sterol sensing at the endoplasmic reticulum (ER) and sterol export from the plasma membrane (PM). Sterol sensing at the ER requires efficient sterol delivery from the PM; however, the macromolecules that facilitate retrograde sterol transport at the PM have not been identified. ATP-binding cassette transporter A1 (ABCA1) mediates cholesterol and phospholipid export to apolipoprotein A-I for the assembly of high density lipoprotein (HDL). Mutations in ABCA1 cause Tangier disease, a familial HDL deficiency. Several lines of clinical and experimental evidence suggest a second function of ABCA1 in cellular cholesterol homeostasis in addition to mediating cholesterol efflux. Here, we report the unexpected finding that ABCA1 also plays a key role in facilitating retrograde sterol transport from the PM to the ER for sterol sensing. Deficiency in ABCA1 delays sterol esterification at the ER and activates the SREBP-2 cleavage pathway. The intrinsic ATPase activity in ABCA1 is required to facilitate retrograde sterol transport. ABCA1 deficiency causes alternation of PM composition and hampers a clathrin-independent endocytic activity that is required for ER sterol sensing. Our finding identifies ABCA1 as a key macromolecule facilitating bidirectional sterol movement at the PM and shows that ABCA1 controls retrograde sterol transport by modulating a certain clathrin-independent endocytic process. PMID:26198636

Actin retrograde flow and actomyosin II arc contraction drive receptor cluster dynamics at the immunological synapse in Jurkat T cells

PubMed Central

Yi, Jason; Wu, Xufeng S.; Crites, Travis; Hammer, John A.

2012-01-01

Actin retrograde flow and actomyosin II contraction have both been implicated in the inward movement of T cell receptor (TCR) microclusters and immunological synapse formation, but no study has integrated and quantified their relative contributions. Using Jurkat T cells expressing fluorescent myosin IIA heavy chain and F-tractin—a novel reporter for F-actin—we now provide direct evidence that the distal supramolecular activation cluster (dSMAC) and peripheral supramolecular activation cluster (pSMAC) correspond to lamellipodial (LP) and lamellar (LM) actin networks, respectively, as hypothesized previously. Our images reveal concentric and contracting actomyosin II arcs/rings at the LM/pSMAC. Moreover, the speeds of centripetally moving TCR microclusters correspond very closely to the rates of actin retrograde flow in the LP/dSMAC and actomyosin II arc contraction in the LM/pSMAC. Using cytochalasin D and jasplakinolide to selectively inhibit actin retrograde flow in the LP/dSMAC and blebbistatin to selectively inhibit actomyosin II arc contraction in the LM/pSMAC, we demonstrate that both forces are required for centripetal TCR microcluster transport. Finally, we show that leukocyte function–associated antigen 1 clusters accumulate over time at the inner aspect of the LM/pSMAC and that this accumulation depends on actomyosin II contraction. Thus actin retrograde flow and actomyosin II arc contraction coordinately drive receptor cluster dynamics at the immunological synapse. PMID:22219382

Silent memory engrams as the basis for retrograde amnesia.

PubMed

Roy, Dheeraj S; Muralidhar, Shruti; Smith, Lillian M; Tonegawa, Susumu

2017-11-14

Recent studies identified neuronal ensembles and circuits that hold specific memory information (memory engrams). Memory engrams are retained under protein synthesis inhibition-induced retrograde amnesia. These engram cells can be activated by optogenetic stimulation for full-fledged recall, but not by stimulation using natural recall cues (thus, amnesia). We call this state of engrams "silent engrams" and the cells bearing them "silent engram cells." The retention of memory information under amnesia suggests that the time-limited protein synthesis following learning is dispensable for memory storage, but may be necessary for effective memory retrieval processes. Here, we show that the full-fledged optogenetic recall persists at least 8 d after learning under protein synthesis inhibition-induced amnesia. This long-term retention of memory information correlates with equally persistent retention of functional engram cell-to-engram cell connectivity. Furthermore, inactivation of the connectivity of engram cell ensembles with its downstream counterparts, but not upstream ones, prevents optogenetic memory recall. Consistent with the previously reported lack of retention of augmented synaptic strength and reduced spine density in silent engram cells, optogenetic memory recall under amnesia is stimulation strength-dependent, with low-power stimulation eliciting only partial recall. Finally, the silent engram cells can be converted to active engram cells by overexpression of α-p-21-activated kinase 1, which increases spine density in engram cells. These results indicate that memory information is retained in a form of silent engram under protein synthesis inhibition-induced retrograde amnesia and support the hypothesis that memory is stored as the specific connectivity between engram cells.

Targeted retrograde transfection of adenovirus vector carrying brain-derived neurotrophic factor gene prevents loss of mouse (twy/twy) anterior horn neurons in vivo sustaining mechanical compression.

PubMed

Xu, Kan; Uchida, Kenzo; Nakajima, Hideaki; Kobayashi, Shigeru; Baba, Hisatoshi

2006-08-01

Immunohistochemical analysis after adenovirus (AdV)-mediated BDNF gene transfer in and around the area of mechanical compression in the cervical spinal cord of the hyperostotic mouse (twy/twy). To investigate the neuroprotective effect of targeted AdV-BDNF gene transfection in the twy mouse with spontaneous chronic compression of the spinal cord motoneurons. Several studies reported the neuroprotective effects of neurotrophins on injured spinal cord. However, no report has described the effect of targeted retrograde neurotrophic gene delivery on motoneuron survival in chronic compression lesions of the cervical spinal cord resembling lesions of myelopathy. LacZ marker gene using adenoviral vector (AdV-LacZ) was used to evaluate retrograde delivery from the sternomastoid muscle in adult twy mice (16-week-old) and (control). Four weeks after the AdV-LacZ or AdV-BDNF injection, the compressed cervical spinal cord was removed en bloc for immunohistologic investigation of b-galactosidase activity and immunoreactivity and immunoblot analyses of BDNF. The number of anterior horn neurons was counted using Nissl, ChAT and AChE staining. Spinal accessory motoneurons between C1 and C3 segments were successfully transfected by AdV-LacZ in both twy and ICR mice after targeted intramuscular injection. Immunoreactivity to BDNF was significantly stronger in AdV-BDNF-gene transfected twy mice than in AdV-LacZ-gene transfected mice. At the cord level showing the maximum compression in AdV-BDNF-transfected twy mice, the number of anterior horn neurons was sinificantly higher in the topographic neuronal cell counting of Nissl-, ChAT-, and AChE-stained samples than in AdV-LacZ-injected twy mice. Targeted AdV-BDNF-gene delivery significantly increased Nissl-stained anterior horn neurons and enhanced cholinergic enzyme activities in the twy. Our results suggest that targeted retrograde AdV-BDNF-gene in vivo delivery may enhance neuronal survival even under chronic mechanical compression.

Brain protection in aortic arch aneurysm: antegrade or retrograde?

PubMed

Harky, Amer; Fok, Matthew; Bashir, Mohamad; Estrera, Anthony L

2018-01-03

During open aortic arch repair, there is an interruption of cerebral perfusion and to prevent neurological sequelae, the hypothermic circulatory arrest has been established to provide sufficient brain protection coupled with adjuncts including retrograde and antegrade cerebral perfusion. To date, brain protection during open aortic arch repair is a contested topic as to which provides superior brain protection with little evidence existing to suggest supremacy of one modality over the other. This article reviews current literature reflecting on key and emerging studies in brain protection and their associated outcomes in patients undergoing open aortic arch surgery.

Rabies virus envelope glycoprotein targets lentiviral vectors to the axonal retrograde pathway in motor neurons.

PubMed

Hislop, James N; Islam, Tarin A; Eleftheriadou, Ioanna; Carpentier, David C J; Trabalza, Antonio; Parkinson, Michael; Schiavo, Giampietro; Mazarakis, Nicholas D

2014-06-06

Rabies pseudotyped lentiviral vectors have great potential in gene therapy, not least because of their ability to transduce neurons following their distal axonal application. However, very little is known about the molecular processes that underlie their retrograde transport and cell transduction. Using multiple labeling techniques and confocal microscopy, we demonstrated that pseudotyping with rabies virus envelope glycoprotein (RV-G) enabled the axonal retrograde transport of two distinct subtypes of lentiviral vector in motor neuron cultures. Analysis of this process revealed that these vectors trafficked through Rab5-positive endosomes and accumulated within a non-acidic Rab7 compartment. RV-G pseudotyped vectors were co-transported with both the tetanus neurotoxin-binding fragment and the membrane proteins thought to mediate rabies virus endocytosis (neural cell adhesion molecule, nicotinic acetylcholine receptor, and p75 neurotrophin receptor), thus demonstrating that pseudotyping with RV-G targets lentiviral vectors for transport along the same pathway exploited by several toxins and viruses. Using motor neurons cultured in compartmentalized chambers, we demonstrated that axonal retrograde transport of these vectors was rapid and efficient; however, it was not able to transduce the targeted neurons efficiently, suggesting that impairment in processes occurring after arrival of the viral vector in the soma is responsible for the low transduction efficiency seen in vivo, which suggests a novel area for improvement of gene therapy vectors. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

A reappraisal of retrograde cerebral perfusion.

PubMed

Ueda, Yuichi

2013-05-01

Brain protection during aortic arch surgery by perfusing cold oxygenated blood into the superior vena cava was first reported by Lemole et al. In 1990 Ueda and associates first described the routine use of continuous retrograde cerebral perfusion (RCP) in thoracic aortic surgery for the purpose of cerebral protection during the interval of obligatory interruption of anterograde cerebral flow. The beneficial effects of RCP may be its ability to sustain brain hypothermia during hypothermic circulatory arrest (HCA) and removal of embolic material from the arterial circulation of the brain. RCP can offer effective brain protection during HCA for about 40 to 60 minutes. Animal experiments revealed that RCP provided inadequate cerebral perfusion and that neurological recovery was improved with selective antegrade cerebral perfusion (ACP), however, both RCP and ACP provide comparable clinical outcomes regarding both the mortality and stroke rates by risk-adjusted and case-matched comparative study. RCP still remains a valuable adjunct for brain protection during aortic arch repair in particular pathologies and patients.

Anterograde and retrograde tracing with high molecular weight biotinylated dextran amine through thalamocortical and corticothalamic pathways.

PubMed

Zhang, Wenjie; Xu, Dongsheng; Cui, Jingjing; Jing, Xianghong; Xu, Nenggui; Liu, Jianhua; Bai, Wanzhu

2017-02-01

Biotinylated dextran amine (BDA) has been used for neural pathway tracing in the central nervous system for many decades, in which high molecular weight BDA appeared to be transported predominantly in the anterograde direction and less in the retrograde direction. In the current study, we reexamined the properties of neural labeling with high molecular weight BDA through a reciprocal neural pathway between thalamus and somatosensory cortex. After injection of BDA into the ventral posteromedial nucleus of thalamus (VPM) in the rat, the BDA labeling was sequentially examined on somatosensory cortex at 3, 5, 7, 10, and 14 survival days. Both of anterogradely labeled axonal terminals and retrogradely labeled neuronal cell bodies were observed simultaneously on the somatosensory cortex. With the increasing of survival times after injection, morphological changes occurred on the labeled axonal arbors and neuronal dendrites, in which the high quality of BDA labeling appeared on the tenth survival day. These results indicate that high molecular weight BDA is not only a sensitive anterograde tracer but also an excellent retrograde marker to be used for tracing through thalamocortical and corticothalamic pathways. And the detailed structure of neural labeling with BDA similar to Golgi-like resolution can be obtained at optimal survival times of animals after the injection of high molecular weight BDA. © 2016 Wiley Periodicals, Inc.

Pre-electroconvulsive shock administration of calcium channel blockers reduces retrograde amnesia induced by ECS.

PubMed

Sushma, M; Sudha, S; Guido, S

2004-11-01

Effect of pre-electroconvulsive shock (ECS) administration of calcium channel blockers (CCBs) like verapamil, diltiazem, nifedipine, nimodipine, flunarizine and cinnarizine on retrograde amnesia induced by ECS was examined using passive avoidance paradigm in rats. The groups (Gr 1-7) of adult, male Wistar rats received true ECS with CCBs (5mg/kg; i.p) or vehicle (10 ml/kg; ip) and other groups (Gr 8-14) received sham ECS with CCBs (5mg/kg; i.p) or vehicle (10 ml/kg; i.p). The anti-amnestic activity of CCBs were evaluated using the passive avoidance paradigm in rats. Results showed that, the baseline latencies for all the groups did not differ significantly. Rats receiving true ECS produced significantly lower latencies. There was increase in the post ECS step through latencies of the rats administered CCBs before ECS. Therefore, pre-ECS administration of calcium channel blockers might reduce retrograde amnesia produced by ECS without altering seizure duration.

Retrograde Signaling from Progranulin to Sort1 Counteracts Synapse Elimination in the Developing Cerebellum.

PubMed

Uesaka, Naofumi; Abe, Manabu; Konno, Kohtarou; Yamazaki, Maya; Sakoori, Kazuto; Watanabe, Takaki; Kao, Tzu-Huei; Mikuni, Takayasu; Watanabe, Masahiko; Sakimura, Kenji; Kano, Masanobu

2018-02-21

Elimination of redundant synapses formed early in development and strengthening of necessary connections are crucial for shaping functional neural circuits. Purkinje cells (PCs) in the neonatal cerebellum are innervated by multiple climbing fibers (CFs) with similar strengths. A single CF is strengthened whereas the other CFs are eliminated in each PC during postnatal development. The underlying mechanisms, particularly for the strengthening of single CFs, are poorly understood. Here we report that progranulin, a multi-functional growth factor implicated in the pathogenesis of frontotemporal dementia, strengthens developing CF synaptic inputs and counteracts their elimination from postnatal day 11 to 16. Progranulin derived from PCs acts retrogradely onto its putative receptor Sort1 on CFs. This effect is independent of semaphorin 3A, another retrograde signaling molecule that counteracts CF synapse elimination. We propose that progranulin-Sort1 signaling strengthens and maintains developing CF inputs, and may contribute to selection of single "winner" CFs that survive synapse elimination. Copyright © 2018 Elsevier Inc. All rights reserved.

Actin Filament Elasticity and Retrograde Flow Shape the Force-Velocity Relation of Motile Cells

PubMed Central

Zimmermann, Juliane; Brunner, Claudia; Enculescu, Mihaela; Goegler, Michael; Ehrlicher, Allen; Käs, Josef; Falcke, Martin

2012-01-01

Cells migrate through a crowded environment during processes such as metastasis or wound healing, and must generate and withstand substantial forces. The cellular motility responses to environmental forces are represented by their force-velocity relation, which has been measured for fish keratocytes but remains unexplained. Even pN opposing forces slow down lamellipodium motion by three orders of magnitude. At larger opposing forces, the retrograde flow of the actin network accelerates until it compensates for polymerization, and cell motion stalls. Subsequently, the lamellipodium adapts to the stalled state. We present a mechanism quantitatively explaining the cell's force-velocity relation and its changes upon application of drugs that hinder actin polymerization or actomyosin-based contractility. Elastic properties of filaments, close to the lamellipodium leading edge, and retrograde flow shape the force-velocity relation. To our knowledge, our results shed new light on how these migratory responses are regulated, and on the mechanics and structure of the lamellipodium. PMID:22339865

[Up-regulation of intrarenal renin-angiotensin system contributes to renal damage in high-salt induced hypertension rats].

PubMed

Wu, Hai-yan; Liang, Yao-xian; Bai, Qiong; Zhuang, Zhen; A, La-ta; Zheng, Dan-xia; Wang, Yue

2015-02-18

To test the hypothesis that in a high-salt induced hypertension in normal rats, whether the changes of intrarenal renin-agiotensin system (RAS) play a critical role in renal damage and could be reflected by urinary angiotensinogen (AGT). In the study, 27 normotensive male Wistar-Kyoto rats were divided into control group [0.3% (mass faction) NaCl in chow, n=9, NS], high-salt diet group [8% (mass faction) NaCl in chow, n=9, HS] and high-salt diet with Losartan group [8% (mass faction) NaCl in chow and 20 mg/(kg×d) Losartan in gavages, n=9, HS+L)], and were fed for six weeks. The blood pressure was monitored and urine samples were collected every 2 weeks. AGTs in plasma, kidney and urine were measured by ELISA kits. The renal cortex expression of mRNA and protein of AGT were measured by Real-time PCR and immunohistochemistry (IHC). The renin activity and ANG II were measured by radioimmunoassay (RIA) kits. Compared with NS, the systolic blood pressure (SBP) [(156 ± 2) mmHg vs. (133 ± 3) mmHg, P<0.05] increased significantly at the end of the 2nd week, and the urinary protein [(14.07 ± 2.84) mg/24 h vs. (7.62 ± 3.02) mg/24 h, P<0.05] increased significantly at the end of the 6th week in HS. Compared with HS, there was no significant difference in SBP (P>0.05) but the proteinuria [(9.69 ± 2.73) mg/24 h vs. (14.07 ± 2.84) mg/24 h, P<0.01] decreased significantly in HS+L. Compared with NS, there was no significant difference in the plasma renin activity, angiotensinogen and ANG II level in HS (P>0.05), but the renal cortex renin content [(8.72 ± 1.98) ng/(mL × h) vs. (4.37 ± 1.26) ng/(mL × h), P<0.05], AGT formation [(4.02 ± 0.60) ng/mg vs. (2.59 ± 0.42) ng/mg, P<0.01], ANG II level [(313.8 ± 48.76) pmol/L vs. (188.9 ± 46.95) pmol/L, P<0.05] were increased significantly in HS, and the urinary AGT and ANG II excretion rates increased significantly (P<0.05). Compared with HS, the plasma renin activity, angiotensinogen and ANG II level were significantly

Retrograde intramedullary nail arthrodesis for avascular necrosis of the talus.

PubMed

Devries, J George; Philbin, Terrence M; Hyer, Christopher F

2010-11-01

Avascular necrosis (AVN) of the talus from any etiology is a devastating pathology. There are few salvage options available and controversy exists as to the surgical management for patients with talar AVN. The authors present their results of tibiotalocalcaneal arthrodesis with a retrograde nail. A comprehensive chart and radiographic review was pulled from our database for patients with AVN of the talus, who were treated by tibiotalocalcaneal fusion with retrograde intramedullary nail. Primary outcome was union, with time to clinical union as a secondary endpoint. Fourteen patients were included. The average age at surgery was 47.4 ± 12.8 years, there were nine female patients, and the average Body Mass Index was 33.5 ± 6.0. Surgical risk factors included two patients who smoked, one was diabetic, and one had a preoperative ulceration. The average time to partial weightbearing was 70.6 ± 25.4 days, and the average time to full weightbearing was 100.6 ± 35.5 days. Four patients had postoperative complications, while no patients required major revision surgery. Twelve patients went on to solid fusion, while two went on to a stable, braceable pseudoarthrosis. Eight patients were able to return to shoes, and eight were able to walk unaided at final followup. Salvage of talar AVN is possible by tibiotalocalcaneal arthrodesis with an intramedullary nail. Physicians may offer this as a salvage option to patients with a high likelihood of successful fusion.

The ins and outs of nuclear re-export of retrogradely transported tRNAs in Saccharomyces cerevisiae

PubMed Central

Pierce, Jacqueline B; Eswara, Manoja BK

2010-01-01

In Saccharomyces cerevisiae intron-containing pre-tRNAs are exported from the nucleus to the cytoplasm for removal of the introns, and the spliced tRNAs are returned to the nucleus for reasons that are not understood. The re-imported spliced tRNAs are then subjected to aminoacylation in the nucleolus to ensure that they are functional prior to re-export to the cytoplasm. Previous studies have shown that re-imported spliced tRNAs and mature tRNAs made entirely in the nucleus from intronless precursors are retained in the nucleus of S. cerevisiae in response to glucose, amino acid, nitrogen or inorganic phosphate deprivation. Contrary to these studies, we recently reported that starvation of S. cerevisiae of amino acids or nitrogen results in nuclear accumulation of re-imported spliced tRNAs, but not tRNAs made from intronless precursors. This finding suggests that separate pathways are used for nuclear export of retrogradely transported spliced tRNAs and tRNAs made from intronless pre-tRNAs. In addition, the data support the conclusion that the nuclear re-export pathway for retrogradely transported spliced tRNAs, but not the pathway responsible for nuclear export of tRNAs derived from intronless precursors is regulated during amino acid or nitrogen starvation. This regulation appears to occur at a step after the re-imported spliced tRNAs have undergone aminoacylation quality assurance and, in part, involves the TORC1 signalling pathway. Moreover, it was established that Utp9p is an intranuclear component that only facilitates nuclear re-export of retrogradely transported spliced tRNAs by the β-karyopherin Msn5p. Utp9p acts in concert with Utp8p, a key player in nuclear tRNA export in S. cerevisiae, to translocate aminoacylated re-imported spliced tRNAs from the nucleolus to Msn5p and assist with formation of the Msn5p-tRNA-Gsp1p-GTP export complex. This pathway, however, is not the only one responsible for nuclear re-export of retrogradely transported spliced t

Silent memory engrams as the basis for retrograde amnesia

PubMed Central

Roy, Dheeraj S.; Muralidhar, Shruti; Smith, Lillian M.

2017-01-01

Recent studies identified neuronal ensembles and circuits that hold specific memory information (memory engrams). Memory engrams are retained under protein synthesis inhibition-induced retrograde amnesia. These engram cells can be activated by optogenetic stimulation for full-fledged recall, but not by stimulation using natural recall cues (thus, amnesia). We call this state of engrams “silent engrams” and the cells bearing them “silent engram cells.” The retention of memory information under amnesia suggests that the time-limited protein synthesis following learning is dispensable for memory storage, but may be necessary for effective memory retrieval processes. Here, we show that the full-fledged optogenetic recall persists at least 8 d after learning under protein synthesis inhibition-induced amnesia. This long-term retention of memory information correlates with equally persistent retention of functional engram cell-to-engram cell connectivity. Furthermore, inactivation of the connectivity of engram cell ensembles with its downstream counterparts, but not upstream ones, prevents optogenetic memory recall. Consistent with the previously reported lack of retention of augmented synaptic strength and reduced spine density in silent engram cells, optogenetic memory recall under amnesia is stimulation strength-dependent, with low-power stimulation eliciting only partial recall. Finally, the silent engram cells can be converted to active engram cells by overexpression of α-p-21–activated kinase 1, which increases spine density in engram cells. These results indicate that memory information is retained in a form of silent engram under protein synthesis inhibition-induced retrograde amnesia and support the hypothesis that memory is stored as the specific connectivity between engram cells. PMID:29078397

Thylakoid redox signals are integrated into organellar-gene-expression-dependent retrograde signaling in the prors1-1 mutant

PubMed Central

Tadini, Luca; Romani, Isidora; Pribil, Mathias; Jahns, Peter; Leister, Dario; Pesaresi, Paolo

2012-01-01

Perturbations in organellar gene expression (OGE) and the thylakoid redox state (TRS) activate retrograde signaling pathways that adaptively modify nuclear gene expression (NGE), according to developmental and metabolic needs. The prors1-1 mutation in Arabidopsis down-regulates the expression of the nuclear gene Prolyl-tRNA Synthetase1 (PRORS1) which acts in both plastids and mitochondria, thereby impairing protein synthesis in both organelles and triggering OGE-dependent retrograde signaling. Because the mutation also affects thylakoid electron transport, TRS-dependent signals may likewise have an impact on the changes in NGE observed in this genotype. In this study, we have investigated whether signals related to TRS are actually integrated into the OGE-dependent retrograde signaling pathway. To this end, the chaos mutation (for chlorophyll a/b binding protein harvesting-organelle specific), which shows a partial loss of PSII antennae proteins and thus a reduction in PSII light absorption capability, was introduced into the prors1-1 mutant background. The resulting double mutant displayed a prors1-1-like reduction in plastid translation rate and a chaos-like decrease in PSII antenna size, whereas the hyper-reduction of the thylakoid electron transport chain, caused by the prors1-1 mutation, was alleviated, as determined by monitoring chlorophyll (Chl) fluorescence and thylakoid phosphorylation. Interestingly, a substantial fraction of the nucleus-encoded photosynthesis genes down-regulated in the prors1-1 mutant are expressed at nearly wild-type rates in prors1-1 chaos leaves, and this recovery is reflected in the steady-state levels of their protein products in the chloroplast. We therefore conclude that signals related to photosynthetic electron transport and TRS, and indirectly to carbohydrate metabolism and energy balance, are indeed fed into the OGE-dependent retrograde pathway to modulate NGE and adjust the abundance of chloroplast proteins. PMID:23293642

Synaptic plasticity in the medial vestibular nuclei: role of glutamate receptors and retrograde messengers in rat brainstem slices.

PubMed

Grassi, S; Pettorossi, V E

2001-08-01

The analysis of cellular-molecular events mediating synaptic plasticity within vestibular nuclei is an attempt to explain the mechanisms underlying vestibular plasticity phenomena. The present review is meant to illustrate the main results, obtained in vitro, on the mechanisms underlying long-term changes in synaptic strength within the medial vestibular nuclei. The synaptic plasticity phenomena taking place at the level of vestibular nuclei could be useful for adapting and consolidating the efficacy of vestibular neuron responsiveness to environmental requirements, as during visuo-vestibular recalibration and vestibular compensation. Following a general introduction on the most salient features of vestibular compensation and visuo-vestibular adaptation, which are two plastic events involving neuronal circuitry within the medial vestibular nuclei, the second and third sections describe the results from rat brainstem slice studies, demonstrating the possibility to induce long-term potentiation and depression in the medial vestibular nuclei, following high frequency stimulation of the primary vestibular afferents. In particular the mechanisms sustaining the induction and expression of vestibular long-term potentiation and depression, such as the role of various glutamate receptors and retrograde messengers have been described. The relevant role of the interaction between the platelet-activating factor, acting as a retrograde messenger, and the presynaptic metabotropic glutamate receptors, in determining the full expression of vestibular long-term potentiation is also underlined. In addition, the mechanisms involved in vestibular long-term potentiation have been compared with those leading to long-term potentiation in the hippocampus to emphasize the most significant differences emerging from vestibular studies. The fourth part, describes recent results demonstrating the essential role of nitric oxide, another retrograde messenger, in the induction of vestibular

Golgi-to-Endoplasmic Reticulum (ER) Retrograde Traffic in Yeast Requires Dsl1p, a Component of the ER Target Site that Interacts with a COPI Coat Subunit

PubMed Central

Reilly, Barbara A.; Kraynack, Bryan A.; VanRheenen, Susan M.; Waters, M. Gerard

2001-01-01

DSL1 was identified through its genetic interaction with SLY1, which encodes a t-SNARE-interacting protein that functions in endoplasmic reticulum (ER)-to-Golgi traffic. Conditional dsl1 mutants exhibit a block in ER-to-Golgi traffic at the restrictive temperature. Here, we show that dsl1 mutants are defective for retrograde Golgi-to-ER traffic, even under conditions where no anterograde transport block is evident. These results suggest that the primary function of Dsl1p may be in retrograde traffic, and that retrograde defects can lead to secondary defects in anterograde traffic. Dsl1p is an ER-localized peripheral membrane protein that can be extracted from the membrane in a multiprotein complex. Immunoisolation of the complex yielded Dsl1p and proteins of ∼80 and ∼55 kDa. The ∼80-kDa protein has been identified as Tip20p, a protein that others have shown to exist in a tight complex with Sec20p, which is ∼50 kDa. Both Sec20p and Tip20p function in retrograde Golgi-to-ER traffic, are ER-localized, and bind to the ER t-SNARE Ufe1p. These findings suggest that an ER-localized complex of Dsl1p, Sec20p, and Tip20p functions in retrograde traffic, perhaps upstream of a Sly1p/Ufe1p complex. Last, we show that Dsl1p interacts with the δ-subunit of the retrograde COPI coat, Ret2p, and discuss possible roles for this interaction. PMID:11739780

Asna1/TRC40 Controls β-Cell Function and Endoplasmic Reticulum Homeostasis by Ensuring Retrograde Transport.

PubMed

Norlin, Stefan; Parekh, Vishal S; Naredi, Peter; Edlund, Helena

2016-01-01

Type 2 diabetes (T2D) is characterized by insulin resistance and β-cell failure. Insulin resistance per se, however, does not provoke overt diabetes as long as compensatory β-cell function is maintained. The increased demand for insulin stresses the β-cell endoplasmic reticulum (ER) and secretory pathway, and ER stress is associated with β-cell failure in T2D. The tail recognition complex (TRC) pathway, including Asna1/TRC40, is implicated in the maintenance of endomembrane trafficking and ER homeostasis. To gain insight into the role of Asna1/TRC40 in maintaining endomembrane homeostasis and β-cell function, we inactivated Asna1 in β-cells of mice. We show that Asna1(β-/-) mice develop hypoinsulinemia, impaired insulin secretion, and glucose intolerance that rapidly progresses to overt diabetes. Loss of Asna1 function leads to perturbed plasma membrane-to-trans Golgi network and Golgi-to-ER retrograde transport as well as to ER stress in β-cells. Of note, pharmacological inhibition of retrograde transport in isolated islets and insulinoma cells mimicked the phenotype of Asna1(β-/-) β-cells and resulted in reduced insulin content and ER stress. These data support a model where Asna1 ensures retrograde transport and, hence, ER and insulin homeostasis in β-cells. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Retrograde Endourological Management of Upper Urinary Tract Abnormalities in Patients with Ileal Conduit Urinary Diversion: A Dual-Center Experience.

PubMed

Olson, Louise; Satherley, Hywel; Cleaveland, Paul; Zelhof, Bachar; Mokete, Max; Neilson, Donald; Srirangam, Shalom

2017-09-01

Patients with ileal conduit urinary diversions are at an increased risk of long-term upper urinary tract (UUT) complications, including anastomotic strictures, infections, and urolithiasis. The reconstructed urinary system poses challenges for endoscopic manipulation. We present and describe our dual-center experience in performing retrograde ureteroscopy to treat or diagnose UUT abnormalities in patients with ileal conduit incontinent diversion. We performed a retrospective analysis of medical records for all patients with previous urinary diversion who underwent retrograde ureteroscopic procedures via the ileal loop in our institutions over a 9 year period (between June 2007 and August 2016). Fifty-four procedures were performed in 36 patients. Mean age was 61 (28-90) years. Average time from diversion to ureteroscopic procedure was 13.0 (0.08-53) years. Stone disease was the most common indication for intervention in 35.2% (19/54) of cases, with a stone-free rate of 78.9% (15/19). Other indications included surveillance of transitional-cell carcinoma in 22.2% (12/54), diagnostic flexible ureteroscopy (fURS) in 20.4% (11/54), stricture management in 11.1% (6/54), removal of encrusted stent/nephrostomy in 7.4% (4/54), urine leak after diversion in 1.9% (1/54), and miscellaneous in 1.9% (1/54). Successful retrograde access was possible in 74% (40/54) of cases. A long and tortuous ileal segment, too difficult to negotiate, was the most common cause of failure to access the UUT. In 13 out of 54 (24.1%) cases, retrograde fURS was combined with simultaneous percutaneous antegrade access. Six patients (11.1%) developed postprocedural pyrexia requiring additional antibiotic therapy, and one (1.9%) patient required embolization of the renal artery for ongoing bleeding. Median length of stay was 1 day (0-55), with 13 (24%) being performed as day-case procedures. Retrograde ureteroscopy in patients with ileal conduits can be technically challenging due to distorted anatomy

Lissencephaly-1 dependent axonal retrograde transport of L1-type CAM Neuroglian in the adult drosophila central nervous system

PubMed Central

Börner, Jana; Slipchuk, Olesya; Kakad, Priyanka; Lee, LaTasha H.; Qureshi, Aater; Pielage, Jan

2017-01-01

Here, we established the Drosophila Giant Fiber neurons (GF) as a novel model to study axonal trafficking of L1-type Cell Adhesion Molecules (CAM) Neuroglian (Nrg) in the adult CNS using live imaging. L1-type CAMs are well known for their importance in nervous system development and we previously demonstrated a role for Nrg in GF synapse formation. However, in the adult they have also been implicated in synaptic plasticity and regeneration. In addition, to its canonical role in organizing cytoskeletal elements at the plasma membrane, vertebrate L1CAM has also been shown to regulate transcription indirectly as well as directly via its import to the nucleus. Here, we intend to determine if the sole L1CAM homolog Nrg is retrogradley transported and thus has the potential to relay signals from the synapse to the soma. Live imaging of c-terminally tagged Nrg in the GF revealed that there are at least two populations of retrograde vesicles that differ in speed, and either move with consistent or varying velocity. To determine if endogenous Nrg is retrogradely transported, we inhibited two key regulators, Lissencephaly-1 (Lis1) and Dynactin, of the retrograde motor protein Dynein. Similar to previously described phenotypes for expression of poisonous subunits of Dynactin, we found that developmental knock down of Lis1 disrupted GF synaptic terminal growth and that Nrg vesicles accumulated inside the stunted terminals in both mutant backgrounds. Moreover, post mitotic Lis1 knock down in mature GFs by either RNAi or Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) induced mutations, resulted in normal length terminals with fully functional GF synapses which also exhibited severe accumulation of endogenous Nrg vesicles. Thus, our data suggests that accumulation of Nrg vesicles is due to failure of retrograde transport rather than a failure of terminal development. Together with the finding that post mitotic knock down of Lis1 also disrupted retrograde

Lissencephaly-1 dependent axonal retrograde transport of L1-type CAM Neuroglian in the adult drosophila central nervous system.

PubMed

Kudumala, Sirisha R; Penserga, Tyrone; Börner, Jana; Slipchuk, Olesya; Kakad, Priyanka; Lee, LaTasha H; Qureshi, Aater; Pielage, Jan; Godenschwege, Tanja A

2017-01-01

Here, we established the Drosophila Giant Fiber neurons (GF) as a novel model to study axonal trafficking of L1-type Cell Adhesion Molecules (CAM) Neuroglian (Nrg) in the adult CNS using live imaging. L1-type CAMs are well known for their importance in nervous system development and we previously demonstrated a role for Nrg in GF synapse formation. However, in the adult they have also been implicated in synaptic plasticity and regeneration. In addition, to its canonical role in organizing cytoskeletal elements at the plasma membrane, vertebrate L1CAM has also been shown to regulate transcription indirectly as well as directly via its import to the nucleus. Here, we intend to determine if the sole L1CAM homolog Nrg is retrogradley transported and thus has the potential to relay signals from the synapse to the soma. Live imaging of c-terminally tagged Nrg in the GF revealed that there are at least two populations of retrograde vesicles that differ in speed, and either move with consistent or varying velocity. To determine if endogenous Nrg is retrogradely transported, we inhibited two key regulators, Lissencephaly-1 (Lis1) and Dynactin, of the retrograde motor protein Dynein. Similar to previously described phenotypes for expression of poisonous subunits of Dynactin, we found that developmental knock down of Lis1 disrupted GF synaptic terminal growth and that Nrg vesicles accumulated inside the stunted terminals in both mutant backgrounds. Moreover, post mitotic Lis1 knock down in mature GFs by either RNAi or Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) induced mutations, resulted in normal length terminals with fully functional GF synapses which also exhibited severe accumulation of endogenous Nrg vesicles. Thus, our data suggests that accumulation of Nrg vesicles is due to failure of retrograde transport rather than a failure of terminal development. Together with the finding that post mitotic knock down of Lis1 also disrupted retrograde

New Frontiers in the Intrarenal Renin-Angiotensin System: A Critical Review of Classical and New Paradigms

PubMed Central

Zhuo, Jia L.; Ferrao, Fernanda M.; Zheng, Yun; Li, Xiao C.

2013-01-01

The renin-angiotensin system (RAS) is well-recognized as one of the oldest and most important regulators of arterial blood pressure, cardiovascular, and renal function. New frontiers have recently emerged in the RAS research well beyond its classic paradigm as a potent vasoconstrictor, an aldosterone release stimulator, or a sodium-retaining hormone. First, two new members of the RAS have been uncovered, which include the renin/(Pro)renin receptor (PRR) and angiotensin-converting enzyme 2 (ACE2). Recent studies suggest that prorenin may act on the PRR independent of the classical ACE/ANG II/AT1 receptor axis, whereas ACE2 may degrade ANG II to generate ANG (1–7), which activates the Mas receptor. Second, there is increasing evidence that ANG II may function as an intracellular peptide to activate intracellular and/or nuclear receptors. Third, currently there is a debate on the relative contribution of systemic versus intrarenal RAS to the physiological regulation of blood pressure and the development of hypertension. The objectives of this article are to review and discuss the new insights and perspectives derived from recent studies using novel transgenic mice that either overexpress or are deficient of one key enzyme, ANG peptide, or receptor of the RAS. This information may help us better understand how ANG II acts, both independently or through interactions with other members of the system, to regulate the kidney function and blood pressure in health and disease. PMID:24273531

Retrograde episodic memory and emotion: a perspective from patients with dissociative amnesia.

PubMed

Reinhold, Nadine; Markowitsch, Hans J

2009-09-01

With his recent definition of episodic memory Tulving [Tulving, E. (2005). Episodic memory and autonoesis: Uniquely human? In H. Terrace & J. Metcalfe (Eds.), The missing link in cognition: Evolution of self-knowing consciousness (pp. 3-56). New York: Oxford University Press] claims that this memory system is uniquely human and thereby distinguishes human beings from other, even highly developed, mammals. First we will define the term episodic memory as it is currently used in neuropsychological research by specifying the three underlying concepts of subjective time, autonoëtic consciousness, and the self. By doing so, we will strongly focus on retrograde episodic memory and its relation to emotion and self-referential processing. We support this relation with a discussion of autobiographical memory functions in psychiatric disorders such as dissociative amnesia. To illustrate the connection of emotion and retrograde episodic memory we shortly present neuropsychological data of two cases of dissociative amnesia. Both cases serve to point to the protective mechanism of a block of self-endangering memories from the episodic memory system, often described as the mnestic block syndrome. On the basis of these cases and supportive results from further cases we will conclude by pointing out similarities and differences of patients with organic and dissociative (psychogenic) amnesia.

TorsinA controls TAN line assembly and the retrograde flow of dorsal perinuclear actin cables during rearward nuclear movement

PubMed Central

Saunders, Cosmo A.; Harris, Nathan J.; Willey, Patrick T.; Woolums, Brian M.; Wang, Yuexia; McQuown, Alex J.; Schoenhofen, Amy; Dauer, William T.

2017-01-01

The nucleus is positioned toward the rear of most migratory cells. In fibroblasts and myoblasts polarizing for migration, retrograde actin flow moves the nucleus rearward, resulting in the orientation of the centrosome in the direction of migration. In this study, we report that the nuclear envelope–localized AAA+ (ATPase associated with various cellular activities) torsinA (TA) and its activator, the inner nuclear membrane protein lamina-associated polypeptide 1 (LAP1), are required for rearward nuclear movement during centrosome orientation in migrating fibroblasts. Both TA and LAP1 contributed to the assembly of transmembrane actin-associated nuclear (TAN) lines, which couple the nucleus to dorsal perinuclear actin cables undergoing retrograde flow. In addition, TA localized to TAN lines and was necessary for the proper mobility of EGFP-mini–nesprin-2G, a functional TAN line reporter construct, within the nuclear envelope. Furthermore, TA and LAP1 were indispensable for the retrograde flow of dorsal perinuclear actin cables, supporting the recently proposed function for the nucleus in spatially organizing actin flow and cytoplasmic polarity. Collectively, these results identify TA as a key regulator of actin-dependent rearward nuclear movement during centrosome orientation. PMID:28242745

Structure of waxy maize starch hydrolyzed by maltogenic alpha-amylase in relation to its retrogradation

USDA-ARS?s Scientific Manuscript database

Maltogenic a-amylase is widely used as an antistaling agent in bakery foods. The objective of this study was to determine the degree of hydrolysis (DH) and starch structure after maltogenic amylase treatments in relation to its retrogradation. Waxy maize starch was cooked and hydrolyzed to different...

A reappraisal of retrograde cerebral perfusion

PubMed Central

2013-01-01

Brain protection during aortic arch surgery by perfusing cold oxygenated blood into the superior vena cava was first reported by Lemole et al. In 1990 Ueda and associates first described the routine use of continuous retrograde cerebral perfusion (RCP) in thoracic aortic surgery for the purpose of cerebral protection during the interval of obligatory interruption of anterograde cerebral flow. The beneficial effects of RCP may be its ability to sustain brain hypothermia during hypothermic circulatory arrest (HCA) and removal of embolic material from the arterial circulation of the brain. RCP can offer effective brain protection during HCA for about 40 to 60 minutes. Animal experiments revealed that RCP provided inadequate cerebral perfusion and that neurological recovery was improved with selective antegrade cerebral perfusion (ACP), however, both RCP and ACP provide comparable clinical outcomes regarding both the mortality and stroke rates by risk-adjusted and case-matched comparative study. RCP still remains a valuable adjunct for brain protection during aortic arch repair in particular pathologies and patients. PMID:23977600

Processing of hemojuvelin requires retrograde trafficking to the Golgi in HepG2 cells.

PubMed

Maxson, Julia E; Enns, Caroline A; Zhang, An-Sheng

2009-02-19

Hemojuvelin (HJV) was recently identified as a critical regulator of iron homeostasis. It is either associated with cell membranes through a glycosylphosphatidylinositol anchor or released as a soluble form. Membrane-anchored HJV acts as a coreceptor for bone morphogenetic proteins and activates the transcription of hepcidin, a hormone that regulates iron efflux from cells. Soluble HJV antagonizes bone morphogenetic protein signaling and suppresses hepcidin expression. In this study, we examined the trafficking and processing of HJV. Cellular HJV reached the plasma membrane without obtaining complex oligosaccharides, indicating that HJV avoided Golgi processing. Secreted HJV, in contrast, has complex oligosaccharides and can be derived from HJV with high-mannose oligosaccharides at the plasma membrane. Our results support a model in which retrograde trafficking of HJV before cleavage is the predominant processing pathway. Release of HJV requires it to bind to the transmembrane receptor neogenin. Neogenin does not, however, play a role in HJV trafficking to the cell surface, suggesting that it could be involved either in retrograde trafficking of HJV or in cleavage leading to HJV release.

Processing of hemojuvelin requires retrograde trafficking to the Golgi in HepG2 cells

PubMed Central

Maxson, Julia E.; Enns, Caroline A.

2009-01-01

Hemojuvelin (HJV) was recently identified as a critical regulator of iron homeostasis. It is either associated with cell membranes through a glycosylphosphatidylinositol anchor or released as a soluble form. Membrane-anchored HJV acts as a coreceptor for bone morphogenetic proteins and activates the transcription of hepcidin, a hormone that regulates iron efflux from cells. Soluble HJV antagonizes bone morphogenetic protein signaling and suppresses hepcidin expression. In this study, we examined the trafficking and processing of HJV. Cellular HJV reached the plasma membrane without obtaining complex oligosaccharides, indicating that HJV avoided Golgi processing. Secreted HJV, in contrast, has complex oligosaccharides and can be derived from HJV with high-mannose oligosaccharides at the plasma membrane. Our results support a model in which retrograde trafficking of HJV before cleavage is the predominant processing pathway. Release of HJV requires it to bind to the transmembrane receptor neogenin. Neogenin does not, however, play a role in HJV trafficking to the cell surface, suggesting that it could be involved either in retrograde trafficking of HJV or in cleavage leading to HJV release. PMID:19029439

Slit2 as a β-catenin/Ctnnb1-dependent retrograde signal for presynaptic differentiation

PubMed Central

Wu, Haitao; Barik, Arnab; Lu, Yisheng; Shen, Chengyong; Bowman, Andrew; Li, Lei; Sathyamurthy, Anupama; Lin, Thiri W; Xiong, Wen-Cheng; Mei, Lin

2015-01-01

Neuromuscular junction formation requires proper interaction between motoneurons and muscle cells. β-Catenin (Ctnnb1) in muscle is critical for motoneuron differentiation; however, little is known about the relevant retrograde signal. In this paper, we dissected which functions of muscle Ctnnb1 are critical by an in vivo transgenic approach. We show that Ctnnb1 mutant without the transactivation domain was unable to rescue presynaptic deficits of Ctnnb1 mutation, indicating the involvement of transcription regulation. On the other hand, the cell-adhesion function of Ctnnb1 is dispensable. We screened for proteins that may serve as a Ctnnb1-directed retrograde factor and identified Slit2. Transgenic expression of Slit2 specifically in the muscle was able to diminish presynaptic deficits by Ctnnb1 mutation in mice. Slit2 immobilized on beads was able to induce synaptophysin puncta in axons of spinal cord explants. Together, these observations suggest that Slit2 serves as a factor utilized by muscle Ctnnb1 to direct presynaptic differentiation. DOI: http://dx.doi.org/10.7554/eLife.07266.001 PMID:26159615

Scanning electron microscopy (SEM) evaluation of sealing ability of MTA and EndoSequence as root-end filling materials with chitosan and carboxymethyl chitosan (CMC) as retrograde smear layer removing agents.

PubMed

Nagesh, Bolla; Jeevani, Eppala; Sujana, Varri; Damaraju, Bharagavi; Sreeha, Kaluvakolanu; Ramesh, Penumaka

2016-01-01

The purpose of this study was to evaluate the sealing ability of mineral trioxide aggregate (MTA) and EndoSequence with chitosan and carboxymethyl chitosan (CMC) as retrograde smear layer removing agents using scanning electron microscopy (SEM). Forty human single rooted teeth were taken. Crowns were decoronated and canals were obturated. Apically roots were resected and retrograde cavities were done. Based on the type of retrograde material placed and the type of smear layer removal agent used for retrograde cavities, they were divided into four groups (N = 10): Group I chitosan with EndoSequence, group II chitosan with MTA, group III CMC with EndoSequence, and Group IV CMC with MTA. All the samples were longitudinally sectioned, and the SEM analysis was done for marginal adaptation. Kruskal-Wallis and Mann-Witney analysis tests. SEM images showed the presence of less gaps in group III, i.e., CMC with EndoSequence when compared to other groups with statistically significant difference. Within the limited scope of this study, it was concluded that EndoSequence as retrograde material showed better marginal sealing ability.

[Feasibility and safety evaluation of retrograde inserting of ureteric catheter via flexible cystoscope].

PubMed

Jin, Xiao-dong; Li, Zhong-yi; Luo, Xue-hong; Chen, Zhao-dian; Cai, Song-liang; Xie, Li-ping

2008-06-24

To introduce a method of retrograde ureteric catheter placement via flexible cystoscope , and to evaluate the feasibility and safety of this method. 112 patients, 62 males and 50 females undergoing retrograde ureteropyelography by 2 same physicians in cooperation were randomly divided into two equal groups with 31 males and 25 females each: one group via flexible cystoscope and the other group via rigid cystoscope. The catheterizing time, visual analogue scale (VAS) pain score, gross hematuria rate, and fever rate were compared between these 2 groups. Fifty-five patients underwent ureteric catheter placement successfully via flexible cystoscope (98%, 55/56), while 53 cases were technically successful by rigid cystoscope (95%, 53/56). The inserting time in women patients of the flexible cystoscopy group was (7.6 +/- 1.8) min, significantly shorter than that of the men [(8.0 +/- 1.8) min, P < 0.05]. The inserting time in women patients of the rigid cystoscopy group was (7.4 +/- 1.5) min, significantly shorter than that of the men [(8.2 +/- 1.2) min, P < 0.05]. However, there were not significant differences in the inserting times in both men and women between these 2 groups (both P > 0.05). The VAS pain scores in men and women of the flexible cystoscope group were 3. 5 and 2. 3 respectively, both significantly lower than those of the rigid cystoscopy group (7.2 and 3.3 respectively, both P < 0.05). The gross hematuria rate of the flexible cystoscope group was 8.6% (5/56), significantly lower than that of the rigid cystoscopy group (25.0%, 14/56, P < 0.05). Four patients had a fever after flexible cystoscopy while 6 cases did after rigid cystoscopy, however, without significant difference between these 2 groups (P > 0.05). Retrograde placement of ureteric catheter via flexible cystoscope is safe and reliable as rigid cystoscopy. Meanwhile, inserting ureteric catheter via flexible cystoscope causes the patients less pain and less chance of hematuria.

Endoscopic balloon catheter dilatation via retrograde or static technique is safe and effective for cricopharyngeal dysfunction

PubMed Central

Chandrasekhara, Vinay; Koh, Joyce; Lattimer, Lakshmi; Dunbar, Kerry B; Ravich, William J; Clarke, John O

2017-01-01

AIM To evaluate the safety and efficacy of upper esophageal sphincter (UES) dilatation for cricopharyngeal (CP) dysfunction. To determine if: (1) indication for dilatation; or (2) technique of dilatation correlated with symptom improvement. METHODS All balloon dilatations performed at our institution from over a 3-year period were retrospectively analyzed for demographics, indication and dilatation site. All dilatations involving the UES underwent further review to determine efficacy, complications, and factors that predict success. Dilatation technique was separated into static (stationary balloon distention) and retrograde (brusque pull-back of a fully distended balloon across the UES). RESULTS Four hundred and eighty-eight dilatations were reviewed. Thirty-one patients were identified who underwent UES dilatation. Median age was 63 years (range 27-81) and 55% of patients were male. Indications included dysphagia (28 patients), globus sensation with evidence of UES dysfunction (2 patients) and obstruction to echocardiography probe with cricopharyngeal (CP) bar (1 patient). There was evidence of concurrent oropharyngeal dysfunction in 16 patients (52%) and a small Zenker’s diverticula (≤ 2 cm) in 7 patients (23%). Dilator size ranged from 15 mm to 20 mm. Of the 31 patients, 11 had dilatation of other esophageal segments concurrently with UES dilatation and 20 had UES dilatation alone. Follow-up was available for 24 patients for a median of 2.5 mo (interquartile range 1-10 mo), of whom 19 reported symptomatic improvement (79%). For patients undergoing UES dilatation alone, follow-up was available for 15 patients, 12 of whom reported improvement (80%). Nineteen patients underwent retrograde dilatation (84% response) while 5 patients had static dilatation (60% response); however, there was no significant difference in symptom improvement between the techniques (P = 0.5). Successful symptom resolution was also not significantly affected by dilator size

Trafficking of cell surface beta-amyloid precursor protein: retrograde and transcytotic transport in cultured neurons

PubMed Central

1995-01-01

Amyloid beta-protein (A beta), the principal constituent of senile plaques seen in Alzheimer's disease (AD), is derived by proteolysis from the beta-amyloid precursor protein (beta PP). The mechanism of A beta production in neurons, which are hypothesized to be a rich source of A beta in brain, remains to be defined. In this study, we describe a detailed localization of cell surface beta PP and its subsequent trafficking in primary cultured neurons. Full-length cell surface beta PP was present primarily on perikarya and axons, the latter with a characteristic discontinuous pattern. At growth cones, cell surface beta PP was inconsistently detected. By visualizing the distribution of beta PP monoclonal antibodies added to intact cultures, beta PP was shown to be internalized from distal axons or terminals and retrogradely transported back to perikarya in organelles which colocalized with fluid-phase endocytic markers. Retrograde transport of beta PP was shown in both hippocampal and peripheral sympathetic neurons, the latter using a compartment culture system that isolated cell bodies from distal axons and terminals. In addition, we demonstrated that beta PP from distal axons was transcytotically transported to the surface of perikarya from distal axons in sympathetic neurons. Indirect evidence of this transcytotic pathway was obtained in hippocampal neurons using antisense oligonucleotide to the kinesin heavy chain to inhibit anterograde beta PP transport. Taken together, these results demonstrate novel aspects of beta PP trafficking in neurons, including retrograde axonal transport and transcytosis. Moreover, the axonal predominance of cell surface beta PP is unexpected in view of the recent report of polarized sorting of beta PP to the basolateral domain of MDCK cells. PMID:7721945

Outcomes of long retrograde intramedullary nailing for periprosthetic supracondylar femoral fractures following total knee arthroplasty.

PubMed

Lee, Sung-San; Lim, Seung-Jae; Moon, Young-Wan; Seo, Jai-Gon

2014-01-01

The treatment of periprosthetic supracondylar femoral fractures following total knee arthroplasty (TKA) is challenging because of osteopenia and the limited bone available for distal fixation. The purpose of this study was to report the outcomes of periprosthetic supracondylar femoral fractures treated with long retrograde intramedullary nailing. We conducted a retrospective review of 25 patients who were treated with a long retrograde intramedullary nail for periprosthetic supracondylar femoral fractures following TKA. Clinical evaluation included range of motion of knee, Knee Society Score (KSS), Western Ontario and McMaster Universities Arthritis (WOMAC) score, and radiologic evaluation including time to union, coronal and sagittal alignment of femoral component, lower limb alignment, and implant loosening. The mean duration of follow-up after the fracture repair was 39 months (range 12-47). All 25 fractures were united with a mean time of 12 weeks (range 8-20). At the last follow-up, the mean knee flexion was 111° (range 60°-130°), the mean KSS was 81.5 (range 50-100), and the mean WOMAC score was 30.2 (range 5-55). Four (16%) of the 25 patients developed malalignment according to Rorabeck and Taylor criteria, but all patients had a knee flexion of more than 90°. Coronal and sagittal alignments of femoral component and lower limb alignment did not differ significantly between before and after the fracture repair. Complications included the loosening or breakage of distal interlocking screws in three patients. No deep infection or prosthesis loosening was detected at the last follow-up. Surgical treatment of periprosthetic supracondylar femoral fractures following TKA with long retrograde intramedullary nailing resulted in high union rates and encouraging functional outcomes.

A chloroplast retrograde signal, 3'-phosphoadenosine 5'-phosphate, acts as a secondary messenger in abscisic acid signaling in stomatal closure and germination.

PubMed

Pornsiriwong, Wannarat; Estavillo, Gonzalo M; Chan, Kai Xun; Tee, Estee E; Ganguly, Diep; Crisp, Peter A; Phua, Su Yin; Zhao, Chenchen; Qiu, Jiaen; Park, Jiyoung; Yong, Miing Tiem; Nisar, Nazia; Yadav, Arun Kumar; Schwessinger, Benjamin; Rathjen, John; Cazzonelli, Christopher I; Wilson, Philippa B; Gilliham, Matthew; Chen, Zhong-Hua; Pogson, Barry J

2017-03-21

Organelle-nuclear retrograde signaling regulates gene expression, but its roles in specialized cells and integration with hormonal signaling remain enigmatic. Here we show that the SAL1-PAP (3'-phosphoadenosine 5'- phosphate) retrograde pathway interacts with abscisic acid (ABA) signaling to regulate stomatal closure and seed germination in Arabidopsis . Genetically or exogenously manipulating PAP bypasses the canonical signaling components ABA Insensitive 1 (ABI1) and Open Stomata 1 (OST1); priming an alternative pathway that restores ABA-responsive gene expression, ROS bursts, ion channel function, stomatal closure and drought tolerance in ost1 -2. PAP also inhibits wild type and abi1 -1 seed germination by enhancing ABA sensitivity. PAP-XRN signaling interacts with ABA, ROS and Ca 2+ ; up-regulating multiple ABA signaling components, including lowly-expressed Calcium Dependent Protein Kinases (CDPKs) capable of activating the anion channel SLAC1. Thus, PAP exhibits many secondary messenger attributes and exemplifies how retrograde signals can have broader roles in hormone signaling, allowing chloroplasts to fine-tune physiological responses.

Clinical usefulness of a short-type, prototype single-balloon enteroscope for endoscopic retrograde cholangiopancreatography in patients with altered gastrointestinal anatomy: preliminary experiences.

PubMed

Kawamura, Takuji; Uno, Koji; Suzuki, Azumi; Mandai, Koichiro; Nakase, Kojiro; Tanaka, Kiyohito; Yasuda, Kenjiro

2015-01-01

A limited number of endoscopic retrograde cholangiopancreatography (ERCP) accessories are compatible with the conventional single-balloon enteroscope (SBE) because of the latter's dimensions. The aim of the present study was to assess the utility of a prototype SBE that has a shorter working length and a wider channel than the conventional SBE. ERCP procedures carried out between January 2012 and July 2013 using the short SBE prototype were reconstructions such as Billroth II (B-II), post-gastrectomy with Roux-en-Y (RY-G), and post-choledochojejunostomy with Roux-en-Y (RY-CJ). We retrospectively analyzed the rate of reaching the blind end of the intestine, the diagnostic success rate, the interventional success rate, and the frequency of related complications. Twenty-seven ERCP procedures on 18 patients analyzed comprised two B-II, 15 RY-G, and 10 RY-CJ reconstructions. With a mean procedure time of 56 min (range 40-150 min), the rate of reaching the blind end, the diagnostic success rate, and the interventional success rate were 24/27 (89%), 20/27 (74%), and 19/27 (70%), respectively. There were no major ERCP-related complications in any patient. The prototype short-type SBE appears safe and effective for use in ERCP, and is compatible with conventional endoscopy accessories. © 2014 The Authors. Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society.

Reexposure to the Amnestic Agent Alleviates Cycloheximide-Induced Retrograde Amnesia for Reactivated and Extinction Memories

ERIC Educational Resources Information Center

Briggs, James F.; Olson, Brian P.

2013-01-01

We investigated whether reexposure to an amnestic agent would reverse amnesia for extinction of learned fear similar to that of a reactivated memory. When cycloheximide (CHX) was administered immediately after a brief cue-induced memory reactivation (15 sec) and an extended extinction session (12 min) rats showed retrograde amnesia for both…

Flexible endoscopes: structure and function: the endoscopic retrograde cholangiopancreatography elevator system.

PubMed

Holland, Pat; Shoop, Nancy M

2002-01-01

Flexible endoscopes are complex medical instruments that are easily damaged. In order to maintain the flexible endoscope in optimum working condition, the user must have a thorough understanding of the structure and function of the instrument. This is the fourth in a series of articles presenting an in-depth look at the care and handling of the flexible endoscope. The first three articles discussed the air-water system, the suction channel system, and the mechanical system. This article will focus specifically on the endoscopic retrograde cholangiopancreatography elevator system.

Mid-term follow-up of patients with hindfoot arthrodesis with retrograde compression intramedullary nail in Charcot neuroarthropathy of the hindfoot.

PubMed

Chraim, M; Krenn, S; Alrabai, H M; Trnka, H-J; Bock, P

2018-02-01

Hindfoot arthrodesis with retrograde intramedullary nailing has been described as a surgical strategy to reconstruct deformities of the ankle and hindfoot in patients with Charcot arthropathy. This study presents case series of Charcot arthropathy patients treated with two different retrograde intramedullary straight compression nails in order to reconstruct the hindfoot and assess the results over a mid-term follow-up. We performed a retrospective analysis of 18 consecutive patients and 19 operated feet with Charcot arthropathy who underwent a hindfoot arthrodesis using a retrograde intramedullary compression nail. Patients were ten men and eight women with a mean age of 63.43 years (38.5 to 79.8). We report the rate of limb salvage, complications requiring additional surgery, and fusion rate in both groups. The mean duration of follow-up was 46.36 months (37 to 70). The limb salvage rate was 16 of 19 limbs. Three patients had to undergo below-knee amputation due to persistent infection followed by osteomyelitis resistant to parenteral antibiotic therapy and repeated debridement. Complications including infection, hardware removal, nonunion, and persistent ulcers requiring further intervention were also observed. Postoperative functional scores revealed significant improvement compared with preoperative scores on American Orthopaedic Foot and Ankle Society (AOFAS) - Hindfoot scale, Foot Function Index (FFI), visual analogue scale (VAS), and Foot and Ankle Outcome Score (FAOS). The use of retrograde intramedullary compression nail results in good rates of limb salvage when used for hindfoot reconstruction in patients with Charcot arthropathy. Cite this article: Bone Joint J 2018;100-B:190-6. ©2018 The British Editorial Society of Bone & Joint Surgery.

Recovery from anterograde and retrograde amnesia after percutaneous drainage of a cystic craniopharyngioma.

PubMed Central

Ignelzi, R J; Squire, L R

1976-01-01

A case is reported of a cystic craniopharyngioma involving the floor and walls of the third ventricle. Pronounced anterograde and retrograde amnesia were documented preoperatively by formal testing. Rapid improvement in both new learning capacity and remote memory occurred after percutaneous twist drill drainage of the cystic portion of the tumour. The relevance of these observations to the amnesic syndrome and its neuropathological basis is discussed. Images PMID:1011035

[Hindfoot fusion for Charcot osteoarthropathy with a curved retrograde nail].

PubMed

Pyrc, J; Fuchs, A; Zwipp, H; Rammelt, S

2015-01-01

Charcot osteoarthropathy of the hindfoot with considerable dislocation and instability represents a therapeutic dilemma. The treatment goal is a plantigrade, stable foot that is free of infection and ulceration with the ability to ambulate in special footwear. Over a period of 6 years, we performed 23 hindfoot fusions in 21 patients with manifest Charcot arthropathy with the help of a curved retrograde nail (HAN). All patients suffered from insulin-dependent diabetes mellitus with polyneuropathy; 12 patients had additional peripheral vasculopathy. An average of 3.5 previous surgeries had been performed prior to hindfoot fusion. Complete tibiotalocalcaneal fusion was obtained in 16 of 21 patients (76 %). Of these 21 patients, 18 (86 %) were followed clinically and radiologically for an average of 2 years. Overall, 16 patients (89 %) reported a substantial subjective improvement compared to the preoperative state. Hardware failure occurred in 7 cases (30 %) that could be brought to consolidation with exchange of the locking bolts or the complete nail. In 5 cases (22 %), a postoperative hematoma had to be removed and in 8 cases (35 %) wound edge necrosis was treated with local wound care. In 2 cases (9 %), a secondary or reactivated osteitis occurred that finally required below knee amputation. Tibiotalocalcaneal fusion with a curved retrograde intramedullary nail (HAN) is an effective treatment option in highly unstable and deforming Charcot osteoarthropathy of the hindfoot. It is an alternative to external or other internal fixation methods and helps to avoid below knee amputation in more than 90 % of cases.

An Innovative Approach to the Repair of Distal Tibia Nonunion Using a Retrograde Buried Tibio-Talar-Calcaneal Nail: A Case Report.

PubMed

Van Steyn, Peter; Romash, Michael

We report a case using retrograde tibial nailing as treatment of nonunion of a distal tibial osteotomy, which was performed as part of a complex reconstruction of distal tibial malunion with ankle arthritis. Although retrograde nailing has classically been used for tibial-talar-calcaneal arthrodesis, this method spares the subtalar joint. Preservation of some hindfoot motion by subtalar mobility allows for a decrease in the loss of function typically seen with tibial-talar-calcaneal arthrodesis. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Intrarenal renin-angiotensin system mediates fatty acid-induced ER stress in the kidney

PubMed Central

Li, Chunling; Lin, Yu; Luo, Renfei; Chen, Shaoming; Zheng, Peili; Levi, Moshe; Yang, Tianxin; Wang, Weidong

2015-01-01

Obesity-related kidney disease is related to caloric excess promoting deleterious cellular responses. Accumulation of saturated free fatty acids in tubular cells produces lipotoxicity involving significant cellular dysfunction and injury. The objectives of this study were to elucidate the role of renin-angiotensin system (RAS) activation in saturated fatty acid-induced endoplasmic reticulum (ER) stress in cultured human proximal tubule epithelial cells (HK2) and in mice fed with a high-fat diet. Treatment with saturated fatty acid palmitic acid (PA; 0.8 mM) for 24 h induced ER stress in HK2, leading to an unfolded protein response as reflected by increased expressions of the ER chaperone binding immunoglobulin protein (BiP) and proapoptotic transcription factor C/EBP homologous protein (CHOP) protein as evaluated by immunoblotting. PA treatment also induced increased protein expression of inositol requiring protein 1α (IRE1α), phosphorylated eukaryotic initiation factor-α (eIF2α), and activating transcription factor 4 (ATF4) as well as activation of caspase-3. PA treatment was associated with increased angiotensin II levels in cultured medium. The angiotensin II type 1 receptor (AT1R) blocker valsartan or renin inhibitor aliskiren dramatically suppressed PA-induced upregulation of BiP, CHOP, IRE1α, p-eIF2α, and ATF4 in HK2 cells. In contrast, valsartan or aliskiren did not prevent ER stress induced by tunicamycin. C57BL/6 mice fed with a high-fat diet for 14 wk exhibited increased protein expressions of BiP and CHOP compared with control mice, which were significantly attenuated by the valsartan treatment. Increased angiotensin II levels in serum and urine were observed in mice fed with a high-fat diet when compared with controls. It is suggested that the intrarenal RAS activation may play an important role in diabetic kidney injury via mediating ER stress induced by saturated fatty acid. PMID:26672616

Effects of Olmesartan and Azilsartan on Albuminuria and the Intrarenal Renin-Angiotensin System

PubMed Central

Takami, Takeshi; Okada, Sadanori; Saito, Yoshihiko; Nishijima, Yoko; Kobori, Hiroyuki; Nishiyama, Akira

2018-01-01

Purpose Olmesartan and azilsartan decrease blood pressure more effectively than other angiotensin receptor blockers (ARBs). ARBs additionally decrease the urinary albumin to creatinine ratio (UACR), a urinary albumin marker, and urinary angiotensinogen (u-AGT), an intrarenal renin-angiotensin system activity marker. We examined the effects of these ARBs on blood pressure, UACR, and u-AGT in patients with uncontrolled hypertension. Methods Patients with uncontrolled hypertension treated with conventional ARBs, excluding olmesartan and azilsartan, for over 8 weeks were enrolled. We randomly switched patients from their prior ARBs to either olmesartan or azilsartan, and followed them for 24 weeks. Results Systolic blood pressure (SBP), diastolic blood pressure (DBP), and central systolic blood pressure (cSBP) significantly decreased at 24 weeks. UACR and u-AGT also decreased at 24 weeks in both groups. There were no significant differences in SBP, DBP, cSBP, UACR, or u-AGT between the groups. Therefore, we combined both groups for further analyses. After combining, SBP (160.5 ± 16.4 to 139.6 ± 15.6 mm Hg, P < 0.0001), DBP (88.4 ± 13.7 to 80.7 ± 13.2 mm Hg, P = 0.008), cSBP (167.4 ± 20.8 to 146.6 ± 24.6 mm Hg, P < 0.0001), UACR (13.8 to 9.0 mg/g Cre, P = 0.0096), and u-AGT (4.13 to 2.32 μg/g Cre, P = 0.0074) significantly decreased at 24 weeks. Patients with microalbuminuria (UACR ≥ 30 mg/g Cre) had significantly greater ΔUACR (−39.4 vs 0.27, P = 0.0024) and Δu-AGT (−11.9 vs −0.61, P = 0.0235) than patients without microalbuminuria. The changes in u-AGT were significantly associated with changes in UACR (r = 0.411, P = 0.046); however, there was no significant relationship between the changes in u-AGT and those in SBP or DBP. Conclusion Olmesartan and azilsartan decreased blood pressure, UACR, and u-AGT more than the other ARBs, and exerted depressor and renoprotective effects. PMID:29683146

Effects of Olmesartan and Azilsartan on Albuminuria and the Intrarenal Renin-Angiotensin System.

PubMed

Takami, Takeshi; Okada, Sadanori; Saito, Yoshihiko; Nishijima, Yoko; Kobori, Hiroyuki; Nishiyama, Akira

2018-01-01

Olmesartan and azilsartan decrease blood pressure more effectively than other angiotensin receptor blockers (ARBs). ARBs additionally decrease the urinary albumin to creatinine ratio (UACR), a urinary albumin marker, and urinary angiotensinogen (u-AGT), an intrarenal renin-angiotensin system activity marker. We examined the effects of these ARBs on blood pressure, UACR, and u-AGT in patients with uncontrolled hypertension. Patients with uncontrolled hypertension treated with conventional ARBs, excluding olmesartan and azilsartan, for over 8 weeks were enrolled. We randomly switched patients from their prior ARBs to either olmesartan or azilsartan, and followed them for 24 weeks. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and central systolic blood pressure (cSBP) significantly decreased at 24 weeks. UACR and u-AGT also decreased at 24 weeks in both groups. There were no significant differences in SBP, DBP, cSBP, UACR, or u-AGT between the groups. Therefore, we combined both groups for further analyses. After combining, SBP (160.5 ± 16.4 to 139.6 ± 15.6 mm Hg, P < 0.0001), DBP (88.4 ± 13.7 to 80.7 ± 13.2 mm Hg, P = 0.008), cSBP (167.4 ± 20.8 to 146.6 ± 24.6 mm Hg, P < 0.0001), UACR (13.8 to 9.0 mg/g Cre, P = 0.0096), and u-AGT (4.13 to 2.32 μg/g Cre, P = 0.0074) significantly decreased at 24 weeks. Patients with microalbuminuria (UACR ≥ 30 mg/g Cre) had significantly greater ΔUACR (-39.4 vs 0.27, P = 0.0024) and Δu-AGT (-11.9 vs -0.61, P = 0.0235) than patients without microalbuminuria. The changes in u-AGT were significantly associated with changes in UACR (r = 0.411, P = 0.046); however, there was no significant relationship between the changes in u-AGT and those in SBP or DBP. Olmesartan and azilsartan decreased blood pressure, UACR, and u-AGT more than the other ARBs, and exerted depressor and renoprotective effects.

A mechanistic approach to studies of the possible digestion of retrograded starch by α-amylase revealed using a log of slope (LOS) plot

PubMed Central

Patel, Hamung; Day, Richard; Butterworth, Peter J.; Ellis, Peter R.

2014-01-01

The rate and extent of digestibility of starch were analysed using the logarithm of the slope (LOS) method. Digestibility curves with α-amylase were obtained for starches in their native, gelatinised and 24 h retrograded form. A LOS plot of the digestibility curves was then constructed, which allowed the rate constant (k) and the concentration of the product at the end of the reaction (C∞) to be calculated. It also allowed the identification of rapid and slow phases in starch digestion. Upon gelatinisation, both k and C∞ increased with dramatic changes notably in C∞; however after starch samples had been stored for 24 h at room temperature, k was not affected but C∞ decreased. This suggests that retrograded starch is virtually inert to amylase action. Both k and C∞ were strongly related to the increase in degree of order of the α-glucan chains, monitored by FTIR-ATR spectroscopy, in retrograded starch. PMID:25256473

Multicenter study of retrograde open mesenteric artery stenting through laparotomy for treatment of acute and chronic mesenteric ischemia.

PubMed

Oderich, Gustavo S; Macedo, Rodrigo; Stone, David H; Woo, Edward Y; Panneton, Jean M; Resch, Timothy; Dias, Nuno V; Sonesson, Björn; Schermerhorn, Marc L; Lee, Jason T; Kalra, Manju; DeMartino, Randall R; Sandri, Giuliano de A; Ramos Tenorio, Emanuel J

2018-03-13

Retrograde open mesenteric stenting (ROMS) through laparotomy was introduced as an alternative to surgical bypass in patients with acute mesenteric ischemia (AMI). The purpose of this study was to evaluate the indications and outcomes of ROMS for treatment of AMI and chronic mesenteric ischemia. We reviewed the clinical data and outcomes of all consecutive patients treated by ROMS in seven academic centers from 2001 to 2013. ROMS was performed through laparotomy with retrograde access into the target mesenteric artery and stent placement using a retrograde or antegrade approach. End points were early (<30 days) and late mortality, morbidity, patency rates, and freedom from symptom recurrence and reintervention. There were 54 patients, 13 male and 41 female, with a mean age of 72 ± 11 years. Indications for ROMS were AMI in 44 patients (81%) and subacute-on-chronic mesenteric ischemia with flush mesenteric occlusion in 10 patients (19%). A total of 56 target mesenteric vessels were stented, including 52 superior mesenteric arteries and 4 celiac axis lesions, with a mean treatment length of 42 ± 26 mm. Retrograde mesenteric access was used in all patients, but 16 patients also required a simultaneous antegrade brachial approach. The retrograde puncture was closed primarily in 34 patients and with patch angioplasty in 17 patients; 1 patient had manual compression. Bowel resection was needed in 29 patients (66%) with AMI because of perforation or gangrene. Technical success was achieved in all (98%) except one patient for whom ROMS failed, who was treated by bypass. Early mortality was 45% (20/44) for AMI and 10% (1/10) for subacute-on-chronic mesenteric ischemia (P = .04). Early morbidity was 73% for AMI and 50% for subacute-on-chronic mesenteric ischemia (P = .27). Patient survival for the entire cohort was 43% ± 9% at 2 years. Primary patency and secondary patency at 2 years were 76% ± 8% and 90% ± 8%, respectively. Freedom from symptom recurrence

Impaired retrograde transport of axonal autophagosomes contributes to autophagic stress in Alzheimer’s disease neurons

PubMed Central

Tammineni, Prasad; Ye, Xuan; Feng, Tuancheng; Aikal, Daniyal; Cai, Qian

2017-01-01

Neurons face unique challenges of transporting nascent autophagic vacuoles (AVs) from distal axons toward the soma, where mature lysosomes are mainly located. Autophagy defects have been linked to Alzheimer’s disease (AD). However, the mechanisms underlying altered autophagy remain unknown. Here, we demonstrate that defective retrograde transport contributes to autophagic stress in AD axons. Amphisomes predominantly accumulate at axonal terminals of mutant hAPP mice and AD patient brains. Amyloid-β (Aβ) oligomers associate with AVs in AD axons and interact with dynein motors. This interaction impairs dynein recruitment to amphisomes through competitive interruption of dynein-Snapin motor-adaptor coupling, thus immobilizing them in distal axons. Consistently, deletion of Snapin in mice causes AD-like axonal autophagic stress, whereas overexpressing Snapin in hAPP neurons reduces autophagic accumulation at presynaptic terminals by enhancing AV retrograde transport. Altogether, our study provides new mechanistic insight into AD-associated autophagic stress, thus establishing a foundation for ameliorating axonal pathology in AD. DOI: http://dx.doi.org/10.7554/eLife.21776.001 PMID:28085665

Distal axotomy enhances retrograde presynaptic excitability onto injured pyramidal neurons via trans-synaptic signaling.

PubMed

Nagendran, Tharkika; Larsen, Rylan S; Bigler, Rebecca L; Frost, Shawn B; Philpot, Benjamin D; Nudo, Randolph J; Taylor, Anne Marion

2017-09-20

Injury of CNS nerve tracts remodels circuitry through dendritic spine loss and hyper-excitability, thus influencing recovery. Due to the complexity of the CNS, a mechanistic understanding of injury-induced synaptic remodeling remains unclear. Using microfluidic chambers to separate and injure distal axons, we show that axotomy causes retrograde dendritic spine loss at directly injured pyramidal neurons followed by retrograde presynaptic hyper-excitability. These remodeling events require activity at the site of injury, axon-to-soma signaling, and transcription. Similarly, directly injured corticospinal neurons in vivo also exhibit a specific increase in spiking following axon injury. Axotomy-induced hyper-excitability of cultured neurons coincides with elimination of inhibitory inputs onto injured neurons, including those formed onto dendritic spines. Netrin-1 downregulation occurs following axon injury and exogenous netrin-1 applied after injury normalizes spine density, presynaptic excitability, and inhibitory inputs at injured neurons. Our findings show that intrinsic signaling within damaged neurons regulates synaptic remodeling and involves netrin-1 signaling.Spinal cord injury can induce synaptic reorganization and remodeling in the brain. Here the authors study how severed distal axons signal back to the cell body to induce hyperexcitability, loss of inhibition and enhanced presynaptic release through netrin-1.

The chloroplast division mutant caa33 of Arabidopsis thaliana reveals a crucial impact of chloroplast homeostasis on stress acclimation and retrograde plastid-to-nucleus signaling

PubMed Central

Šimková, Klára; Kim, Chanhong; Gacek, Katarzyna; Baruah, Aiswarya; Laloi, Christophe; Apel, Klaus

2011-01-01

SUMMARY Retrograde plastid-to-nucleus signaling tightly controls and coordinates nuclear and plastid gene expression that is required for plastid biogenesis and chloroplast activities. As chloroplasts act as sensors of environmental changes, plastid-derived signaling also modulates stress responses of plants by transferring stress-related signals and altering nuclear gene expression. Various mutant screens have been undertaken to identify constituents of plastid signaling pathways. Almost all mutations identified in these screens have in common that they target plastid-specific but not extra-plastidic functions. They have been suggested to define either genuine constituents of retrograde signaling pathways or components required for the synthesis of plastid signals. Here we report the characterization of the caa33 (constitutive activator of AAA-ATPase) mutant, which reveals another way of how mutations that affect plastid functions may modulate retrograde plastid signaling. caa33 disturbs a plastid-specific function by impeding plastid division thereby perturbing plastid homeostasis. This results in pre-conditioning plants by activating the expression of stress genes, enhancing pathogen resistance and attenuating the plant’s capacity to respond to plastid signals. Our study reveals an intimate link between chloroplast activity and the plant’s susceptibility to stress and emphasizes the need to consider the possible impact of pre-conditioning on retrograde plastid-to-nucleus signaling. PMID:22014227

Influence of Femoral Component Design on Retrograde Femoral Nail Starting Point.

PubMed

Service, Benjamin C; Kang, William; Turnbull, Nathan; Langford, Joshua; Haidukewych, George; Koval, Kenneth J

2015-10-01

Our experience with retrograde femoral nailing after periprosthetic distal femur fractures was that femoral components with deep trochlear grooves posteriorly displace the nail entry point resulting in recurvatum deformity. This study evaluated the influence of distal femoral prosthetic design on the starting point. One hundred lateral knee images were examined. The distal edge of Blumensaat's line was used to create a ratio of its location compared with the maximum anteroposterior condylar width called the starting point ratio (SPR). Femoral trials from 6 manufacturers were analyzed to determine the location of simulated nail position in the sagittal plane compared with the maximum anteroposterior prosthetic width. These measurements were used to create a ratio, the femoral component ratio (FCR). The FCR was compared with the SPR to determine if a femoral component would be at risk for retrograde nail starting point posterior to the Blumensaat's line. The mean SPR was 0.392 ± 0.03, and the mean FCR was 0.416 ± 0.05, which was significantly greater (P = 0.003). The mean FCR was 0.444 ± 0.06 for the cruciate retaining (CR) trials and was 0.393 ± 0.04 for the posterior stabilized trials; this difference was significant (P < 0.001). The FCR for the femoral trials studied was significantly greater than the SPR for native knees and was significantly greater for CR femoral components compared with posterior stabilized components. These findings demonstrate that many total knee prostheses, particularly CR designs, are at risk for a starting point posterior to Blumensaat's line.

Predicting Retrograde Autobiographical Memory Changes Following Electroconvulsive Therapy: Relationships between Individual, Treatment, and Early Clinical Factors.

PubMed

Martin, Donel M; Gálvez, Verònica; Loo, Colleen K

2015-06-19

Loss of personal memories experienced prior to receiving electroconvulsive therapy is common and distressing and in some patients can persist for many months following treatment. Improved understanding of the relationships between individual patient factors, electroconvulsive therapy treatment factors, and clinical indicators measured early in the electroconvulsive therapy course may help clinicians minimize these side effects through better management of the electroconvulsive therapy treatment approach. In this study we examined the associations between the above factors for predicting retrograde autobiographical memory changes following electroconvulsive therapy. Seventy-four depressed participants with major depressive disorder were administered electroconvulsive therapy 3 times per week using either a right unilateral or bitemporal electrode placement and brief or ultrabrief pulse width. Verbal fluency and retrograde autobiographical memory (assessed using the Columbia Autobiographical Memory Interview - Short Form) were tested at baseline and after the last electroconvulsive therapy treatment. Time to reorientation was measured immediately following the third and sixth electroconvulsive therapy treatments. Results confirmed the utility of measuring time to reorientation early during the electroconvulsive therapy treatment course as a predictor of greater retrograde amnesia and the importance of assessing baseline cognitive status for identifying patients at greater risk for developing later side effects. With increased number of electroconvulsive therapy treatments, older age was associated with increased time to reorientation. Consistency of verbal fluency performance was moderately correlated with change in Columbia Autobiographical Memory Interview - Short Form scores following right unilateral electroconvulsive therapy. Electroconvulsive therapy treatment techniques associated with lesser cognitive side effects should be particularly considered for

Predicting Retrograde Autobiographical Memory Changes Following Electroconvulsive Therapy: Relationships between Individual, Treatment, and Early Clinical Factors

PubMed Central

Gálvez, Verònica; Loo, Colleen K.

2015-01-01

Background: Loss of personal memories experienced prior to receiving electroconvulsive therapy is common and distressing and in some patients can persist for many months following treatment. Improved understanding of the relationships between individual patient factors, electroconvulsive therapy treatment factors, and clinical indicators measured early in the electroconvulsive therapy course may help clinicians minimize these side effects through better management of the electroconvulsive therapy treatment approach. In this study we examined the associations between the above factors for predicting retrograde autobiographical memory changes following electroconvulsive therapy. Methods: Seventy-four depressed participants with major depressive disorder were administered electroconvulsive therapy 3 times per week using either a right unilateral or bitemporal electrode placement and brief or ultrabrief pulse width. Verbal fluency and retrograde autobiographical memory (assessed using the Columbia Autobiographical Memory Interview – Short Form) were tested at baseline and after the last electroconvulsive therapy treatment. Time to reorientation was measured immediately following the third and sixth electroconvulsive therapy treatments. Results: Results confirmed the utility of measuring time to reorientation early during the electroconvulsive therapy treatment course as a predictor of greater retrograde amnesia and the importance of assessing baseline cognitive status for identifying patients at greater risk for developing later side effects. With increased number of electroconvulsive therapy treatments, older age was associated with increased time to reorientation. Consistency of verbal fluency performance was moderately correlated with change in Columbia Autobiographical Memory Interview – Short Form scores following right unilateral electroconvulsive therapy. Conclusions: Electroconvulsive therapy treatment techniques associated with lesser cognitive side

Coil-Assisted Retrograde Transvenous Obliteration (CARTO) for the Treatment of Portal Hypertensive Variceal Bleeding: Preliminary Results

PubMed Central

Lee, Edward W; Saab, Sammy; Gomes, Antoinette S; Busuttil, Ronald; McWilliams, Justin; Durazo, Francisco; Han, Steven-Huy; Goldstein, Leonard; Tafti, Bashir A; Moriarty, John; Loh, Christopher T; Kee, Stephen T

2014-01-01

OBJECTIVES: To describe the technical feasibility, safety, and clinical outcomes of coil-assisted retrograde transvenous obliteration (CARTO) in treating portal hypertensive non-esophageal variceal hemorrhage. METHODS: From October 2012 to December 2013, 20 patients who received CARTO for the treatment of portal hypertensive non-esophageal variceal bleeding were retrospectively evaluated. All 20 patients had at least 6-month follow-up. All patients had detachable coils placed to occlude the efferent shunt and retrograde gelfoam embolization to achieve complete thrombosis/obliteration of varices. Technical success, clinical success, rebleeding, and complications were evaluated at follow-up. RESULTS: A 100% technical success rate (defined as achieving complete occlusion of efferent shunt with complete thrombosis/obliteration of bleeding varices and/or stopping variceal bleeding) was demonstrated in all 20 patients. Clinical success rate (defined as no variceal rebleeding) was 100%. Follow-up computed tomography after CARTO demonstrated decrease in size with complete thrombosis and disappearance of the varices in all 20 patients. Thirteen out of the 20 had endoscopic confirmation of resolution of varices. Minor post-CARTO complications, including worsening of esophageal varices (not bleeding) and worsening of ascites/hydrothorax, were noted in 5 patients (25%). One patient passed away at 24 days after the CARTO due to systemic and portal venous thrombosis and multi-organ failure. Otherwise, no major complication was noted. No variceal rebleeding was noted in all 20 patients during mean follow-up of 384±154 days. CONCLUSIONS: CARTO appears to be a technically feasible and safe alternative to traditional balloon-occluded retrograde transvenous obliteration or transjugular intrahepatic portosystemic shunt, with excellent clinical outcomes in treating portal hypertensive non-esophageal variceal bleeding. PMID:25273155

A Hands-on Exploration of the Retrograde Motion of Mars as Seen from the Earth

ERIC Educational Resources Information Center

Pincelli, M. M.; Otranto, S.

2013-01-01

In this paper, we propose a set of activities based on the use of a celestial simulator to gain insights into the retrograde motion of Mars as seen from the Earth. These activities provide a useful link between the heliocentric concepts taught in schools and those tackled in typical introductory physics courses based on classical mechanics for…

On Common Ground: Jost's (1897) Law of Forgetting and Ribot's (1881) Law of Retrograde Amnesia

ERIC Educational Resources Information Center

Wixted, John T.

2004-01-01

T. Ribot's (1881) law of retrograde amnesia states that brain damage impairs recently formed memories to a greater extent than older memories, which is generally taken to imply that memories need time to consolidate. A. Jost's (1897) law of forgetting states that if 2 memories are of the same strength but different ages, the older will decay more…

Blueschist preservation in a retrograded, high-pressure, low-temperature metamorphic terrane, Tinos, Greece: Implications for fluid flow paths in subduction zones

NASA Astrophysics Data System (ADS)

Breeding, Christopher M.; Ague, Jay J.; BröCker, Michael; Bolton, Edward W.

2003-01-01

The preservation of high-pressure, low-temperature (HP-LT) mineral assemblages adjacent to marble unit contacts on the Cycladic island of Tinos in Greece was investigated using a new type of digital outcrop mapping and numerical modeling of metamorphic fluid infiltration. Mineral assemblage distributions in a large blueschist outcrop, adjacent to the basal contact of a 150-meter thick marble horizon, were mapped at centimeter-scale resolution onto digital photographs using a belt-worn computer and graphics editing software. Digital mapping reveals that while most HP-LT rocks in the outcrop were pervasively retrograded to greenschist facies, the marble-blueschist contact zone underwent an even more intense retrogression. Preservation of HP-LT mineral assemblages was mainly restricted to a 10-15 meter zone (or enclave) adjacent to the intensely retrograded lithologic contact. The degree and distribution of the retrograde overprint suggests that pervasively infiltrating fluids were channelized into the marble-blueschist contact and associated veins and flowed around the preserved HP-LT enclave. Numerical modeling of Darcian flow, based on the field observations, suggests that near the marble horizon, deflections in fluid flow paths caused by flow channelization along the high-permeability marble-blueschist contact zone likely resulted in very large fluid fluxes along the lithologic contact and significantly smaller fluxes (as much as 8 times smaller than the input flux) within the narrow, low-flux regions where HP-LT minerals were preserved adjacent to the contact. Our results indicate that lithologic contacts are important conduits for metamorphic fluid flow in subduction zones. Channelization of retrograde fluids into these discrete flow conduits played a critical role in the preservation of HP-LT assemblages.

Gαq/11-mediated intracellular calcium responses to retrograde flow in endothelial cells.

PubMed

Melchior, Benoît; Frangos, John A

2012-08-15

Disturbed flow patterns, including reversal in flow direction, are key factors in the development of dysfunctional endothelial cells (ECs) and atherosclerotic lesions. An almost immediate response of ECs to fluid shear stress is the increase in cytosolic calcium concentration ([Ca(2+)](i)). Whether the source of [Ca(2+)](i) is extracellular, released from Ca(2+) intracellular stores, or both is still undefined, though it is likely dependent on the nature of forces involved. We have previously shown that a change in flow direction (retrograde flow) on a flow-adapted endothelial monolayer induces the remodeling of the cell-cell junction along with a dramatic [Ca(2+)](i) burst compared with cells exposed to unidirectional or orthograde flow. The heterotrimeric G protein-α q and 11 subunit (Gα(q/11)) is a likely candidate in effecting shear-induced increases in [Ca(2+)](i) since its expression is enriched at the junction and has been previously shown to be activated within seconds after onset of flow. In flow-adapted human ECs, we have investigated to what extent the Gα(q/11) pathway mediates calcium dynamics after reversal in flow direction. We observed that the elapsed time to peak [Ca(2+)](i) response to a 10 dyn/cm(2) retrograde shear stress was increased by 11 s in cells silenced with small interfering RNA directed against Gα(q/11). A similar lag in [Ca(2+)](i) transient was observed after cells were treated with the phospholipase C (PLC)-βγ inhibitor, U-73122, or the phosphatidylinositol-specific PLC inhibitor, edelfosine, compared with controls. Lower levels of inositol 1,4,5-trisphosphate accumulation seconds after the onset of flow correlated with the increased lag in [Ca(2+)](i) responses observed with the different treatments. In addition, inhibition of the inositol 1,4,5-trisphosphate receptor entirely abrogated flow-induced [Ca(2+)](i). Taken together, our results identify the Gα(q/11)-PLC pathway as the initial trigger for retrograde flow

IL-1β impairs retrograde flow of BDNF signaling by attenuating endosome trafficking.

PubMed

Carlos, Anthony J; Tong, Liqi; Prieto, G Aleph; Cotman, Carl W

2017-02-02

Pro-inflammatory cytokines accumulate in the brain with age and Alzheimer's disease and can impair neuron health and cognitive function. Brain-derived neurotrophic factor (BDNF) is a key neurotrophin that supports neuron health, function, and synaptic plasticity. The pro-inflammatory cytokine interleukin-1β (IL-1β) impairs BDNF signaling but whether it affects BDNF signaling endosome trafficking has not been studied. This study uses an in vitro approach in primary hippocampal neurons to evaluate the effect of IL-1β on BDNF signaling endosome trafficking. Neurons were cultured in microfluidic chambers that separate the environments of the cell body and its axon terminal, enabling us to specifically treat in axon compartments and trace vesicle trafficking in real-time. We found that IL-1β attenuates BDNF signaling endosomes throughout networks in cultures. In IL-1β-treated cells, overall BDNF endosomal density was decreased, and the colocalization of BDNF endosomes with presynaptic terminals was found to be more than two times higher than in control cultures. Selective IL-1β treatment to the presynaptic compartment in microfluidic chamber attenuated BDNF endosome flux, as measured by reduced BDNF-GFP endosome counts in the somal compartment. Further, IL-1β decreased the BDNF-induced phosphorylation of Erk5, a known BDNF retrograde trafficking target. Mechanistically, the deficiency in trafficking was not due to impaired endocytosis of the BDNF-TrkB complex, or impaired transport rate, since BDNF endosomes traveled at the same rate in both control and IL-1β treatment groups. Among the regulators of presynaptic endosome sorting is the post-translational modification, ubiquitination. In support of this possibility, the IL-1β-mediated suppression of BDNF-induced Erk5 phosphorylation can be rescued by exogenous ubiquitin C-terminal hydrolase L1 (UCH-L1), a deubiquitinating enzyme that regulates ubiquitin and endosomal trafficking. We observed a state of

Tibio-talo-calcaneal arthrodesis by a retrograde intramedullary nail.

PubMed

Haaker, Rolf; Kohja, E Y; Wojciechowski, Mariusz; Gruber, Gerd

2010-01-01

The paper presents the results of tibio-talo-calcaneal fusions using Retrograde Nailing System and Bone Grafting. From May 2006 to January 2008, we performed 13 fusions in 11 consecutive patients with advanced ankle and hindfoot disease. Patients underwent 13 tibiotalocalcaneal fusions (2 patients had initial tibiotalocalcaneal fusion using screws and subsequently developed a non-union) and all 11 patients were available for follow up. The procedure was performed unilaterally in all cases; there were 4 males and 7 females. The average age at the time of surgery was 65.25 years (range 51-81 years). The average duration of follow-up was 8 months (range between 6-15 months). Solid fusion was achieved in all 11 cases. The average AOFAS score (maximum 78 points) improved from a pre-operative mean of 16 points [range 3 to 29] to a mean of 54 points [range 42 to 70], excluding the scores for stability and range of motion. Patient satisfaction scale (maximum 10 points) improved from 3 to 7 in both pain and function. 1- Arthrodesis should be considered only after all conservative treatments fails; it is one of the most challenging surgical procedures that must be undertaken with care in order to provide the best possible outcome. 2- Thorough evaluation and examination will help the surgeon to find the correct indication and identify patients who are not suitable for the procedure. It is crucial to assess the vascular and neurological status and to obtain weight-bearing radiographs (possibly CT) of the ankle to evaluate the deformity. 3- The optimal position of the ankle is in neutral flexion, 0-5 degrees valgus, and 10 degrees external rotation, similar to the contralateral foot and posterior translation of the talus under the tibia (5mm). 4- Tibio-talo-calcaneal fusion with retrograde nailing and bone grafting is a successful salvage procedure in severe ankle and hind foot arthrosis with deformity.

Worsening cholestasis and possible cefuroxime-induced liver injury following "successful" therapeutic endoscopic retrograde cholangiopancreatography for a distal common bile duct stone: a case report.

PubMed

Niriella, Madunil Anuk; Kumarasena, Ravindu Sujeewa; Dassanayake, Anuradha Supun; Pathirana, Aloka; de Silva Hewavisenthi, Janaki; de Silva, Hithanadura Janaka

2016-12-21

Cefuroxime very rarely causes drug-induced liver injury. We present a case of a patient with paradoxical worsening of jaundice caused by cefuroxime-induced cholestasis following therapeutic endoscopic retrograde cholangiopancreatography for a distal common bile duct stone. A 51-year-old, previously healthy Sri Lankan man presented to our hospital with obstructive jaundice caused by a distal common bile duct stone. Endoscopic retrograde cholangiopancreatography with stone extraction, common bile duct clearance, and stenting failed to improve the cholestasis, with paradoxical worsening of his jaundice. A liver biopsy revealed features of drug-induced intrahepatic cholestasis. Although his case was complicated by an episode of cholangitis, the patient made a complete recovery in 4 months with supportive treatment and withdrawal of the offending drug. This case highlights a very rare drug-induced liver injury caused by cefuroxime as well as our approach to treating a patient with paradoxical worsening of jaundice after therapeutic endoscopic retrograde cholangiopancreatography.

Control of Retrograde Signaling by Rapid Turnover of GENOMES UNCOUPLED11[OPEN

PubMed Central

Chalvin, Camille; Wu, Xu Na

2018-01-01

The exchange of signals between cellular compartments coordinates development and differentiation, modulates metabolic pathways, and triggers responses to environmental conditions. The proposed central regulator of plastid-to-nucleus retrograde signaling, GENOMES UNCOUPLED1 (GUN1), is present at very low levels, which has hampered the discovery of its precise molecular function. Here, we show that the Arabidopsis (Arabidopsis thaliana) GUN1 protein accumulates to detectable levels only at very early stages of leaf development, where it functions in the regulation of chloroplast biogenesis. GUN1 mRNA is present at high levels in all tissues, but GUN1 protein undergoes rapid degradation (with an estimated half-life of ∼4 h) in all tissues where chloroplast biogenesis has been completed. The rapid turnover of GUN1 is controlled mainly by the chaperone ClpC1, suggesting degradation of GUN1 by the Clp protease. Degradation of GUN1 slows under stress conditions that alter retrograde signaling, thus ensuring that the plant has sufficient GUN1 protein. We also find that the pentatricopeptide repeat motifs of GUN1 are important determinants of GUN1 stability. Moreover, overexpression of GUN1 causes an early flowering phenotype, suggesting a function of GUN1 in developmental phase transitions beyond chloroplast biogenesis. Taken together, our results provide new insight into the regulation of GUN1 by proteolytic degradation, uncover its function in early chloroplast biogenesis, and suggest a role in developmental phase transitions. PMID:29367233

Balloon-occluded Retrograde Transvenous Obliteration (BRTO): Technique and Intraprocedural Imaging

PubMed Central

Sabri, Saher S.; Saad, Wael E. A.

2011-01-01

Balloon-occluded retrograde transvenous obliteration (BRTO) is an endovascular technique used as a therapeutic adjunct or alternative to transjugular intrahepatic shunts (TIPS) in the management of gastric varices. Occlusion balloons are strategically placed to modulate flow within the gastrorenal or gastrocaval shunt to allow stagnation of the sclerosant material within the gastric varix. The approach and complexity of the procedure depends on the anatomic classification of inflow and outflow veins of the varix. Ethanolamine oleate has been described as the main sclerosant used in this procedure. Recently, foam sclerosants have gained popularity as alternative embolization agents, which provide the advantage of better variceal wall contact and potentially less dose of sclerosant. PMID:22942548

Filling defects in the pancreatic duct on endoscopic retrograde pancreatography.

PubMed

Taylor, A J; Carmody, T J; Schmalz, M J; Wiedmeyer, D A; Stewart, E T

1992-12-01

Filling defects in the pancreatic duct are a frequent finding during endoscopic retrograde pancreatography (ERP) and have a variety of causes. Some filling defects may be artifactual or related to technical factors and, once their origin is recognized, can be disregarded. Others may be due to acute changes of pancreatitis and should prompt more careful injection of contrast material into the duct. Intraluminal masses may represent calculi or a neoplasm, either of which may require surgery or endoscopic intervention. The exact nature of these filling defects may not be apparent on radiographs, and other studies may be needed. This article reviews our approach to the evaluation of filling defects in the pancreatic duct.

Mitochondrial morphology transitions and functions: implications for retrograde signaling?

PubMed Central

Picard, Martin; Shirihai, Orian S.; Gentil, Benoit J.

2013-01-01

In response to cellular and environmental stresses, mitochondria undergo morphology transitions regulated by dynamic processes of membrane fusion and fission. These events of mitochondrial dynamics are central regulators of cellular activity, but the mechanisms linking mitochondrial shape to cell function remain unclear. One possibility evaluated in this review is that mitochondrial morphological transitions (from elongated to fragmented, and vice-versa) directly modify canonical aspects of the organelle's function, including susceptibility to mitochondrial permeability transition, respiratory properties of the electron transport chain, and reactive oxygen species production. Because outputs derived from mitochondrial metabolism are linked to defined cellular signaling pathways, fusion/fission morphology transitions could regulate mitochondrial function and retrograde signaling. This is hypothesized to provide a dynamic interface between the cell, its genome, and the fluctuating metabolic environment. PMID:23364527

Na(+)-D-glucose cotransporter in the kidney of Squalus acanthias: molecular identification and intrarenal distribution.

PubMed

Althoff, Thorsten; Hentschel, Hartmut; Luig, Jutta; Schütz, Hendrike; Kasch, Myriam; Kinne, Rolf K-H

2006-04-01

Using primers against conserved regions of mammalian Na(+)-d-glucose cotransporters (SGLT), a cDNA was cloned from the kidney of spiny dogfish shark (Squalus acanthias). On the basis of comparison of amino acid sequence, membrane topology, and putative glycosylation and phosphorylation sites, the cDNA could be shown to belong to the family of sglt genes. Indeed, Na(+)-dependent d-glucose uptake could be demonstrated after expression of the gene in Xenopus laevis oocytes. In a dendrogram, the SGLT from shark kidney has a high homology to the mammalian SGLT2. Computer analysis revealed that the elasmobranch protein is most similar to the mammalian proteins in the transmembrane regions and contains already all the amino acids identified to be functionally important, suggesting early conservation during evolution. Extramembraneous loops show larger variations. This holds especially for loop 13, which has been implied as a phlorizin-binding domain. Antibodies were generated and the intrarenal distribution of the SGLT was studied in cryosections. In parallel, the nephron segments were identified by lectins. Positive immunoreactions were found in the proximal tubule in the early parts PIa and PIb and the late segment PIIb. The large PIIa segment of the proximal tubule showed no reaction. In contrast to the mammalian kidney also the late distal tubule, the collecting tubule, and the collecting duct showed immunoreactivity. The molecular information confirms previous vesicle studies in which a low affinity SGLT with a low stoichiometry has been observed and supports the notion of a similarity of the shark kidney SGLT to the mammalian SGLT2. Despite its presence in the late parts of the nephron, the absence of SGLT in the major part of the proximal tubule, the relatively low affinity, and in particular the low stoichiometry might explain the lack of a T(m) for d-glucose in the shark kidney.

Liver Parenchyma Perforation following Endoscopic Retrograde Cholangiopancreatography.

PubMed

Kayashima, Hiroto; Ikegami, Toru; Kasagi, Yuta; Hidaka, Gen; Yamazaki, Koji; Sadanaga, Noriaki; Itoh, Hiroyuki; Emi, Yasunori; Matsuura, Hiroshi; Okadome, Kenichiro

2011-05-01

Although endoscopic retrograde cholangiopancreatography (ERCP) is an effective modality for the diagnosis and treatment of biliary and pancreatic diseases, it is still related with several severe complications. We report on the case of a female patient who developed liver parenchyma perforation following ERCP. She underwent ERCP with sphincterotomy and extraction of a common bile duct stone. Shortly after ERCP, abdominal distension was identified. Abdominal computed tomography revealed intraabdominal air leakage and leakage of contrast dye penetrating the liver parenchyma into the space around the spleen. Since periampullary perforation related to sphincterotomy could not be denied, she was referred for immediate surgery. Obvious perforation could not be found at surgery. Cholecystectomy, insertion of a T tube into the common bile duct, placement of a duodenostomy tube and drainage of the retroperitoneum were performed. She did well postoperatively and was discharged home on postoperative day 28. In conclusion, as it is well recognized that perforation is one of the most serious complication related to ERCP, liver parenchyma perforation should be suspected as a cause.

Percutaneous Retrograde Sclerotherapy for Refractory Bleeding of Jejunal Varices: Direct Injection via Superficial Epigastric Vein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakata, Manabu, E-mail: nktmnbohsu@jichi.ac.jp; Nakata, Waka, E-mail: waka-s@jichi.ac.jp; Isoda, Norio, E-mail: isodano1@jichi.ac.jp

2012-02-15

Small-bowel varices are rare and almost always occur in cases with portal hypertension. We encountered a patient with bleeding jejunal varices due to liver cirrhosis. Percutaneous retrograde sclerotherapy was performed via the superficial epigastric vein. Melena disappeared immediately after treatment. Disappearance of jejunal varices was confirmed by contrast-enhanced computed tomography. After 24 months of follow-up, no recurrent melena was observed.

Remembering and knowing the past: a case study of isolated retrograde amnesia.

PubMed

Dalla Barba, G; Mantovan, M C; Ferruzza, E; Denes, G

1997-03-01

We describe a patient, RM, who suddenly became amnesic for premorbid autobiographic events in the absence of any known precipitating event. Learning abilities as well as semantic knowledge were normal. Knowledge of famous facts and persons was good, although not perfect. Whether RM suffered from organic or psychogenic isolated retrograde amnesia (IRA) could not be established on the basis of available clinical and neuropsychological elements. Regardless of its aetiology, RM's case respects the boundaries between semantic and episodic memory and so gives further support to the distinction between these two memory systems.

A Simple and Novel Method to Attain Retrograde Ureteral Access after Previous Cohen Cross-Trigonal Ureteral Reimplantation

PubMed Central

Adam, Ahmed

2017-01-01

Objective To describe a simple, novel method to achieve ureteric access in the Cohen crossed reimplanted ureter, which will allow retrograde working access via the conventional transurethral method. Materials and Methods Under cystoscopic vision, suprapubic needle puncture was performed. The needle was directed (bevel facing) towards the desired ureteric orifice (UO). A guidewire (with a floppy-tip) was then inserted into the suprapubic needle passing into the bladder, and then easily passed into the crossed-reimplanted UO. The distal end of the guidewire was then removed through the urethra with cystoscopic grasping forceps. The straightened ureter then easily facilitated ureteroscopy access, retrograde pyelogram studies, and JJ stent insertion in a conventional transurethral method. Results The UO and ureter were aligned in a more conventional orthotopic course, to allow for conventional transurethral working access. Conclusion A novel method to access the Cohen crossed reimplanted ureter was described. All previously published methods of accessing the crossed ureter were critically appraised. PMID:29463976

Effect of high hydrostatic pressure and retrogradation treatments on structural and physicochemical properties of waxy wheat starch.

PubMed

Hu, Xiao-Pei; Zhang, Bao; Jin, Zheng-Yu; Xu, Xue-Ming; Chen, Han-Qing

2017-10-01

In this study, the effects of high hydrostatic pressure and retrogradation (HHPR) treatments on in vitro digestibility, structural and physicochemical properties of waxy wheat starch were investigated. The waxy wheat starch slurries (10%, w/v) were treated with high hydrostatic pressures of 300, 400, 500, 600MPa at 20°C for 30min, respectively, and then retrograded at 4°C for 4d. The results indicated that the content of slowly digestible starch (SDS) in HHPR-treated starch samples increased with increasing pressure level, and it reached the maximum (31.12%) at 600MPa. HHPR treatment decreased the gelatinization temperatures, the gelatinization enthalpy, the relative crystallinity and the peak viscosity of the starch samples. Moreover, HHPR treatment destroyed the surface and interior structures of starch granules. These results suggest that the in vitro digestibility, physicochemical, and structural properties of waxy wheat starch are effectively modified by HHPR. Copyright © 2017 Elsevier Ltd. All rights reserved.

Retrograde Ascending Dissection After Thoracic Endovascular Aortic Repair Combined With the Chimney Technique and Successful Open Repair Using the Frozen Elephant Trunk Technique.

PubMed

Hirano, Koji; Tokui, Toshiya; Nakamura, Bun; Inoue, Ryosai; Inagaki, Masahiro; Maze, Yasumi; Kato, Noriyuki

2018-01-01

The chimney technique can be combined with thoracic endovascular aortic repair (TEVAR) to both obtain an appropriate landing zone and maintain blood flow of the arch vessels. However, surgical repair becomes more complicated if retrograde type A aortic dissection occurs after TEVAR with the chimney technique. We herein report a case involving a 73-year-old woman who developed a retrograde ascending dissection 3 months after TEVAR for acute type B aortic dissection. To ensure an adequate proximal sealing distance, the proximal edge of the stent graft was located at the zone 2 level and an additional bare stent was placed at the left subclavian artery (the chimney technique) at the time of TEVAR. Enhanced computed tomography revealed an aortic dissection involving the ascending aorta and aortic arch. Surgical aortic repair using the frozen elephant trunk technique was urgently performed. The patient survived without stroke, paraplegia, renal failure, or other major complications. Retrograde ascending dissection can occur after TEVAR combined with the chimney technique. The frozen elephant trunk technique is useful for surgical repair in such complicated cases.

Semaphorin 3A is a retrograde cell death signal in developing sympathetic neurons

PubMed Central

Wehner, Amanda B.; Abdesselem, Houari; Dickendesher, Travis L.; Imai, Fumiyasu; Yoshida, Yutaka; Giger, Roman J.; Pierchala, Brian A.

2016-01-01

ABSTRACT During development of the peripheral nervous system, excess neurons are generated, most of which will be lost by programmed cell death due to a limited supply of neurotrophic factors from their targets. Other environmental factors, such as ‘competition factors' produced by neurons themselves, and axon guidance molecules have also been implicated in developmental cell death. Semaphorin 3A (Sema3A), in addition to its function as a chemorepulsive guidance cue, can also induce death of sensory neurons in vitro. The extent to which Sema3A regulates developmental cell death in vivo, however, is debated. We show that in compartmentalized cultures of rat sympathetic neurons, a Sema3A-initiated apoptosis signal is retrogradely transported from axon terminals to cell bodies to induce cell death. Sema3A-mediated apoptosis utilizes the extrinsic pathway and requires both neuropilin 1 and plexin A3. Sema3A is not retrogradely transported in older, survival factor-independent sympathetic neurons, and is much less effective at inducing apoptosis in these neurons. Importantly, deletion of either neuropilin 1 or plexin A3 significantly reduces developmental cell death in the superior cervical ganglia. Taken together, a Sema3A-initiated apoptotic signaling complex regulates the apoptosis of sympathetic neurons during the period of naturally occurring cell death. PMID:27143756

Retrograde amnesia in patients with hippocampal, medial temporal, temporal lobe, or frontal pathology.

PubMed

Bright, Peter; Buckman, Joseph; Fradera, Alex; Yoshimasu, Haruo; Colchester, Alan C F; Kopelman, Michael D

2006-01-01

There is considerable controversy concerning the theoretical basis of retrograde amnesia (R.A.). In the present paper, we compare medial temporal, medial plus lateral temporal, and frontal lesion patients on a new autobiographical memory task and measures of the more semantic aspects of memory (famous faces and news events). Only those patients with damage extending beyond the medial temporal cortex into the lateral temporal regions showed severe impairment on free recall remote memory tasks, and this held for both the autobiographical and the more semantic memory tests. However, on t-test analysis, the medial temporal group was impaired in retrieving recent autobiographical memories. Within the medial temporal group, those patients who had combined hippocampal and parahippocampal atrophy (H+) on quantified MRI performed somewhat worse on the semantic tasks than those with atrophy confined to the hippocampi (H-), but scores were very similar on autobiographical episodic recall. Correlational analyses with regional MRI volumes showed that lateral temporal volume was correlated significantly with performance on all three retrograde amnesia tests. The findings are discussed in terms of consolidation, reconsolidation, and multiple trace theory: We suggest that a widely distributed network of regions underlies the retrieval of past memories, and that the extent of lateral temporal damage appears to be critical to the emergence of a severe remote memory impairment.

Right ventral frontal hypometabolism and abnormal sense of self in a case of disproportionate retrograde amnesia.

PubMed

Piolino, Pascale; Hannequin, Didier; Desgranges, Beatrice; Girard, Carole; Beaunieux, Helene; Giffard, Benedicte; Lebreton, Karine; Eustache, Francis

2005-01-01

We report the case of a 42-year-old man (patient CL) who developed a particular profile of amnesia with two dates of onset. At the first onset, the patient suffered a mild/lmoderate injury that accounts for an initial anterograde and mild retrograde memory impairment. At the second onset, 8 months later, he suffered a sudden and persistent loss of personal identity and severe retrograde amnesia. We report an extensive neuropsychological investigation of his memory systems carried out 18 months after the second onset. Results indicated mild executive dysfunction (primary memory), intact procedural skills and perceptual representational system. In accordance with Kopelman's methodological recommendations, we have reliably compared post- and pre-onset semantic and episodic memory using strict matched procedures. We found that post-onset, though not pre-onset semantic (autobiographical and nonautobiographical) memory was entirely preserved. Post-onset episodic autobiographical memory was not intact, however, although it was clearly less affected compared with the total absence of the pre-onset memory. Moreover, a novel and high standard investigation of the subjective states of consciousness, which accompanied retrieval of autobiographical memories via the Remember/lKnow (R/lK) paradigm with a long time interval from the present, demonstrated a deterioration of R responses compared to matched controls. Interestingly, this result showed deficient autonoetic consciousness and suggested an underlying accelerated forgetting rate for post-onset autobiographical episodic memories. Last, a [18F] fluorodeoxyglucose resting PET study revealed a significant right-sided ventral frontal lobe hypometabolism in the absence of overt structural lesions. The involvement of this region is consistent with CL's autobiographical retrograde amnesia and his inability to re-experience information concerning the self across time. In our particular case, characterised by two dates of onset, the

The adipose renin-angiotensin system modulates sysemic markers of insulin sensitivity activates the intrarenal renin-angiotensin system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Suyeon; Soltani-Bejnood, Morvarid; Quignard-Boulange, Annie

2006-07-01

BACKGROUND: A growing body of data provides increasing evidence that the adipose tissue renin-angiotensin system (RAS) contributes to regulation of fat mass. Beyond its paracrine actions within adipose tissue, adipocyte-derived angiotensin II (Ang II) may also impact systemic functions such as blood pressure and metabolism. METHODS AND RESULTS: We used a genetic approach to manipulate adipose RAS activity in mice and then study the consequences on metabolic parameters and on feedback regulation of the RAS. The models included deletion of the angiotensinogen (Agt) gene (Agt-KO), its expression solely in adipose tissue under the control of an adipocyte-specific promoter (aP2-Agt/ Agt-KO),more » and overexpression in adipose tissue of wild type mice (aP2-Agt). Total body weight, epididymal fat pad weight, and circulating levels of leptin, insulin and resistin were significantly decreased in Agt-KO mice, while plasma adiponectin levels were increased. Overexpression of Agt in adipose tissue resulted in increased adiposity and plasma leptin and insulin levels compared to wild type (WT) controls. Angiotensinogen and type I Ang II receptor protein levels were also markedly elevated in kidney of aP2-Agt mice, suggesting that hypertension in these animals may be in part due to stimulation of the intrarenal RAS. CONCLUSIONS: Taken together, the results from this study demonstrate that alterations in adipose RAS activity significantly alter both local and systemic physiology in a way that may contribute to the detrimental health effects of obesity.« less

External-to-Internal Iliac Stent-Graft: Medium-Term Patency Following Exclusion of a Retrogradely Perfused Common Iliac Aneurysm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicholls, Marcus John, E-mail: marcusnicholls@hotmail.co; McPherson, Simon

2010-08-15

Following complicated aortic aneurysm surgery a complete left iliac occlusion resulted in buttock claudication. A retrogradely perfused right common iliac aneurysm expanded. Exclusion was by external-to-internal iliac stent-graft. No deterioration in claudication occurred with medium-term stent-graft patency.

Robot-assisted laparoscopic radical prostatectomy with early retrograde release of the neurovascular bundle and endopelvic fascia sparing

PubMed Central

de Albuquerque, George Augusto Monteiro Lins; Guglielmetti, Giuliano Betoni; Cordeiro, Maurício Dener; Nahas, William Carlos; Coelho, Rafael Ferreira

2017-01-01

ABSTRACT Introduction Robotic-assisted radical prostatectomy (RAP) is the dominant minimally invasive surgical treatment for patients with localized prostate cancer. The introduction of robotic assistance has the potential to improve surgical outcomes and reduce the steep learning curve associated with conventional laparoscopic radical prostatectomy. The purpose of this video is to demonstrate the early retrograde release of the neurovascular bundle without open the endopelvic fascia during RAP. Materials and Methods A 51-year old male, presenting histological diagnosis of prostate adenocarcinoma, Gleason 6 (3+3), in 4 cores of 12, with an initial PSA=3.41ng/dl and the digital rectal examination demonstrating a prostate with hardened nodule in the right lobe of the prostate base (clinical stage T2a). Surgical treatment with the robot-assisted technique was offered as initial therapeutic option and the critical technical point was the early retrograde release of the neurovascular bundle with endopelvic fascia preservation, during radical prostatectomy. Results The operative time was of 89 minutes, blood loss was 100ml. No drain was left in the peritoneal cavity. The patient was discharged within 24 hours. There were no intraoperative or immediate postoperative complications. The pathological evaluation revealed prostate adenocarcinoma, Gleason 6, with free surgical margins and seminal vesicles free of neoplastic involvement (pathologic stage T2a). At 3-month-follow-up, the patient lies with undetectable PSA, continent and potent. Conclusion This is a feasible technique combining the benefits of retrograde release of the neurovascular bundle, the preservation of the pubo-prostatic collar and the preservation of the antero-lateral cavernous nerves. PMID:27802002

Behavioral and Functional Neuroanatomical Correlates of Anterograde Autobiographical Memory in Isolated Retrograde Amnesic Patient M. L.

ERIC Educational Resources Information Center

Levine, Brian; Svoboda, Eva; Turner, Gary R.; Mandic, Marina; Mackey, Allison

2009-01-01

Patient M. L. [Levine, B., Black, S. E., Cabeza, R., Sinden, M., Mcintosh, A. R., Toth, J. P., et al. (1998). "Episodic memory and the self in a case of isolated retrograde amnesia." "Brain", "121", 1951-1973], lost memory for events occurring before his severe traumatic brain injury, yet his anterograde (post-injury) learning and memory appeared…

Increased Dietary Salt Changes Baroreceptor Sensitivity and Intrarenal Renin-Angiotensin System in Goldblatt Hypertension.

PubMed

Shimoura, Caroline G; Lincevicius, Gisele S; Nishi, Erika E; Girardi, Adriana C C; Simon, Karin A; Bergamaschi, Cassia T; Campos, Ruy R

2017-01-01

Renovascular hypertension (2-kidney 1-clip model (2K1C)) is characterized by renin-angiotensin system (RAS) activation. Increased Angiotensin II (AngII) leads to sympathoexcitation, oxidative stress, and alterations in sodium and water balance. The aim of this study was to evaluate whether a discrete increase in sodium chloride intake in 2K1C rats leads to changes in cardiovascular and autonomic function, oxidative stress, and renin angiotensin aldosterone system. After 4 weeks of induction of hypertension, rats were fed a normal sodium diet (0.4% NaCl) or a high-sodium diet (2% NaCl) for 2 consecutive weeks. Experiments were carried out for 6 weeks after clipping. Mean arterial pressure (MAP), renal sympathetic nerve activity (rSNA), arterial baroreflex control of rSNA, and heart rate (HR) were assessed. Thiobarbituric acid reactive substances and glutathione were measured as indicators of systemic oxidative stress. Angiostensin-converting enzyme (ACE), ACE2, and angiotensinogen were evaluated in clipped and unclipped kidneys as also urinary angiotensinogen and plasma renin activity. Angiotensinogen, plasma renin activity (PRA) and angiotensin-converting enzyme (ACE) and ACE2 in clipped and unclipped kidneys were evaluated. High-sodium diet did not change systemic oxidative stress, and basal values of MAP, HR, or rSNA; however, increased renal (-0.7±0.2 vs. -1.5±0.1 spikes/s/mm Hg) and cardiac (-0.9±0.14 vs. -1.5±0.14 bpm/mm Hg) baroreceptor reflex sensitivity in 2K1C rats. Although there was no alteration in PRA, a high-salt diet significantly decreased urinary angiotensinogen, ACE, and ACE2 expressions in the clipped and unclipped kidneys. Increased arterial baroreceptor control associated with a suppression of the intrarenal RAS in the 2K1C rats on high-salt diet provide a salt-resistant effect on hypertension and sympathoexcitation in renovascular hypertensive rats. © American Journal of Hypertension, Ltd 2016. All rights reserved. For Permissions, please

Tibio-talocalcaneal arthrodesis as a primary procedure using a retrograde intramedullary nail: a retrospective study of 26 patients with rheumatoid arthritis.

PubMed

Anderson, Thomas; Linder, Lars; Rydholm, Urban; Montgomery, Fredrik; Besjakov, Jack; Carlsson, Ake

2005-08-01

Arthrodesis of the ankle joint using screws or external fixation is often a demanding procedure, notably in patients with rheumatoid arthritis. We investigated whether tibio-talocalcaneal arthrodesis with the use of an intramedullary nail is a safe and simple procedure. We retrospectively reviewed 25 ankles (25 patients) at median 3 (1-7) years after tibio-talocalcaneal arthrodesis because of rheumatoid arthritis. All had been operated on by retrograde insertion of a retrograde nail. 5 types of nail had been used. Complications, functional outcome scores, and patient satisfaction were determined and the radiographs evaluated for healing. All but 1 ankle had a radiographically healed arthrodesis. We recorded 3 deep infections, all healed--in 2 cases after extraction of the nail--and the arthrodesis healed in all 3 patients. The average functional scores at follow-up were high, considering that the patients suffered from rheumatoid arthritis. 23 patients were satisfied with the outcome. We found a correlation between the functional scores and the general activity of the disease expressed as a Health Assessment Questionnaire score. In patients with rheumatoid arthritis, tibio-talocalcaneal arthrodesis with a retrograde intra-medullary nail results in a high rate of healing, a high rate of patient satisfaction, and relatively few complications.

Retrograde and Direct Powered Aero-Gravity-Assist Trajectories around Mars

NASA Astrophysics Data System (ADS)

Murcia, J. O.; Prado, A. F. B. A.; Gomes, V. M.

2018-04-01

A Gravity-Assist maneuver is used to reduce fuel consumption and/or trip times in interplanetary missions. It is based in a close approach of a spacecraft to a celestial body. Missions like Voyager and Ulysses used this concept. The present paper performs a study of a maneuver that combines three effects: the gravity of the planet, the application of an impulsive maneuver when the spacecraft is passing by the periapsis and the effects of the atmosphere of the planet. Direct and retrograde trajectories are considered, with particular attention to the differences due to the higher relative velocity between the spacecraft and the atmosphere, which increases the effects of the atmosphere. The planet Mars is used for the numerical examples.

A Class of Selenocentric Retrograde Orbits With Innovative Applications to Human Lunar Operations

NASA Technical Reports Server (NTRS)

Adamo, Daniel R.; Lester, Daniel F.; Thronson, Harley A.; Barbee, Brent

2014-01-01

Selenocentric distant retrograde orbits with radii from approx. 12,500 km to approx. 25,000 km are assessed for stability and for suitability as crewed command and control infrastructure locations in support of telerobotic lunar surface operations and interplanetary human transport. Such orbits enable consistent transits to and from Earth at virtually any time if they are coplanar with the Moon's geocentric orbit. They possess multiple attributes and applications distinct from NASA's proposed destination orbit for a redirected asteroid about 70,000 km from the Moon.

A chloroplast retrograde signal, 3’-phosphoadenosine 5’-phosphate, acts as a secondary messenger in abscisic acid signaling in stomatal closure and germination

PubMed Central

Pornsiriwong, Wannarat; Estavillo, Gonzalo M; Chan, Kai Xun; Tee, Estee E; Ganguly, Diep; Crisp, Peter A; Phua, Su Yin; Zhao, Chenchen; Qiu, Jiaen; Park, Jiyoung; Yong, Miing Tiem; Nisar, Nazia; Yadav, Arun Kumar; Schwessinger, Benjamin; Rathjen, John; Cazzonelli, Christopher I; Wilson, Philippa B; Gilliham, Matthew; Chen, Zhong-Hua; Pogson, Barry J

2017-01-01

Organelle-nuclear retrograde signaling regulates gene expression, but its roles in specialized cells and integration with hormonal signaling remain enigmatic. Here we show that the SAL1-PAP (3′-phosphoadenosine 5′- phosphate) retrograde pathway interacts with abscisic acid (ABA) signaling to regulate stomatal closure and seed germination in Arabidopsis. Genetically or exogenously manipulating PAP bypasses the canonical signaling components ABA Insensitive 1 (ABI1) and Open Stomata 1 (OST1); priming an alternative pathway that restores ABA-responsive gene expression, ROS bursts, ion channel function, stomatal closure and drought tolerance in ost1-2. PAP also inhibits wild type and abi1-1 seed germination by enhancing ABA sensitivity. PAP-XRN signaling interacts with ABA, ROS and Ca2+; up-regulating multiple ABA signaling components, including lowly-expressed Calcium Dependent Protein Kinases (CDPKs) capable of activating the anion channel SLAC1. Thus, PAP exhibits many secondary messenger attributes and exemplifies how retrograde signals can have broader roles in hormone signaling, allowing chloroplasts to fine-tune physiological responses. DOI: http://dx.doi.org/10.7554/eLife.23361.001 PMID:28323614

Using Digital Computer Field Mapping of Outcrops to Examine the Preservation of High-P Rocks During Pervasive, Retrograde Greenschist Fluid Infiltration, Tinos, Cyclades Archipelago, Greece

NASA Astrophysics Data System (ADS)

Breeding, C. M.; Ague, J. J.; Broecker, M.

2001-12-01

Digital field mapping of outcrops on the island of Tinos, Greece, was undertaken to investigate the nature of retrograde fluid infiltration during exhumation of high-P metamorphic rocks of the Attic-Cycladic blueschist belt. High-resolution digital photographs of outcrops were taken and loaded into graphics editing software on a portable, belt-mounted computer in the field. Geologic features from outcrops were drawn and labeled on the digital images using the software in real-time. The ability to simultaneously identify geologic features in outcrops and digitize those features onto digital photographs in the field allows the creation of detailed, field-verified, outcrop-scale maps that aid in geologic interpretation. During Cretaceous-Eocene subduction in the Cyclades, downgoing crustal material was metamorphosed to eclogite and blueschist facies. Subsequent Oligocene-Miocene exhumation of the high-P rocks was accompanied by pervasive, retrograde fluid infiltration resulting in nearly complete greenschist facies overprinting. On Tinos, most high-P rocks have undergone intense retrogression; however, adjacent to thick marble horizons with completely retrograded contact zones, small (sub km-scale) enclaves of high-P rocks (blueschist and minor eclogite facies) were preserved. Field observations suggest that the remnant high-P zones consist mostly of massive metabasic rocks and minor adjacent metasediments. Within the enclaves, detailed digital outcrop maps reveal that greenschist retrogression increases in intensity outward from the center, implying interaction with a fluid flowing along enclave perimeters. Permeability contrasts could not have been solely responsible for preservation of the high-P rocks, as similar rock suites distal to marble contacts were completely overprinted. We conclude that the retrograded contacts of the marble units served as high-permeability conduits for regional retrograde fluid flow. Pervasive, layer-parallel flow through metasediments

Hippocampus and Retrograde Amnesia in the Rat Model: A Modest Proposal for the Situation of Systems Consolidation

ERIC Educational Resources Information Center

Sutherland, Robert J.; Sparks, Fraser T.; Lehmann, Hugo

2010-01-01

The properties of retrograde amnesia after damage to the hippocampus have been explicated with some success using a rat model of human medial temporal lobe amnesia. We review the results of this experimental work with rats focusing on several areas of consensus in this growing literature. We evaluate the theoretically significant hypothesis that…

Proficiency of virtual reality simulator training in flexible retrograde ureteroscopy renal stone management.

PubMed

Cai, Jian-liang; Zhang, Yi; Sun, Guo-feng; Li, Ning-chen; Yuan, Xue-li; Na, Yan-qun

2013-10-01

Minimally invasive flexible ureteroscopy techniques have widely adopted in the management of patients with renal stones. We performed this study to investigate the value of virtual reality simulator training in retrograde flexible ureteroscopy renal stone treatment for catechumen. Thirty catechumen, included 17 attending physicians and 13 associate chief physicians, were selected for study. The trainees first underwent 1-hour basic training to get familiar with the instrument and basic procedures, then followed by 4-hour practice on virtual reality simulators. Before and after the 4-hour training, all trainees undertake an assessment with task 7 program (right low pole calyces stone management). We documented for each trainee the total time of procedure, time of progressing from the orifice to stone, stone translocation and fragmentation time, laser operate proficiency scale, total laser energy, maximal size of residual stone fragments, number of trauma from the scopes and tools, damage to the scope and global rating scale (GRS). The proficiency of this training program was analyzed by the comparison of the first and second assessment outcomes. Significant improvement was observed in retrograde flexible ureteroscopy management of renal stone on virtual reality simulators after finishing the 4 hour special-purpose training. This was demonstrated by improvement in total procedure time ((18.37±2.59) minutes vs. (38.67±1.94) minutes), progressing time from the orifice to stone ((4.00±1.08) minutes vs. (13.80±2.01) minutes), time of stone translocation ((1.80±0.71) minutes vs. (6.57±1.01) minutes), fragmentation time ((4.43±1.25) minutes vs. (13.53±1.46) minutes), laser operate proficiency scale (8.47±0.73 vs. 3.77±0.77), total laser energy ((3231.6±401.4) W vs. (5329.8±448.9) W), maximal size of residual stone fragments ((2.66±0.39) mm vs. (5.77±0.63) mm), number of trauma from the scopes and tools (3.27±1.01 vs. 10.37±3.02), damage to the scope (0 vs

Outcome of retrograde ureteric stenting as a urinary drainage procedure in ureteric obstruction related to malignant lesions.

PubMed

Wijayarathna, S; Suvendran, S; Ishak, M; Weligamage, A; Epa, A; Munasinghe, S; Abeygunaskera, A M

2014-12-01

We investigated the outcome of endoscopic retrograde ureteric stenting (RUS) in patients with ureteric obstruction related to malignant lesions. Data were prospectively collected from patients with ureteric obstruction related to malignant lesions treated at a single urology unit from 1 January 2011 to 30 April 2014. All patients had radiologically significant hydronephrosis by ultrasonography and CT scanning. First choice of urinary drainage was placing a retrograde ureteric stent cystoscopically. Outcome of patients who had stenting were recorded after following them until death or removal of stents. Eighty two patients with ureteric obstruction related to malignant lesions had complete data. In 33 (25%) patients, retrograde ureteric stenting was possible. Fifteen of them had recurrent tumour in the pelvis at the time of stenting and 13 (87%) were dead within 3 months of stenting. Four of the five patients who did not have pelvic tumour recurrence were alive at the end of the study. All eight patients who underwent stenting before surgery as a prophylactic measure and three of the five patients who had retroperitoneal tumour mass and underwent RUS were alive. Stenting was not possible in 42 patients. Thirty eight of them had pelvic tumour recurrences and two were having retroperitoneal tumour masses. Only one did not have tumour in the pelvis.CT evidence of tumour recurrence in the pelvis (OR 12.7; 95% CI 1.3-117.6; p=0.026) and high serum creatinine (OR 4.3; 95% CI 1.6-11.7; p=0.004) were associated with failure to ureteric stenting. Chances of successful RUS were low in patients with ureteric obstruction in the presence of tumour recurrences or elevated serum creatinine. Even if ureteric stenting was successful, their life expectancy was short.

Use of the retrograde limb of the internal mammary vein to avoid venous congestion in DIEP flap breast reconstruction: Further evidences of a reliable and time-sparing procedure.

PubMed

La Padula, Simone; Hersant, Barbara; Noel, Warren; Niddam, Jeremy; Hermeziu, Oana; Bouhassira, Jonathan; Bosc, Romain; Meningaud, Jean Paul

2016-09-01

Venous congestion is a common cause of DIEP flap failure. When identified intraoperatively, an additional venous anastomosis can improve the venous outflow and prevent flap failure. The aim of this study was to assess if the retrograde limb of the internal mammary vein (IMV) could be considered a good recipient vessel to be used when persistent flap congestion is present, and a second venous anastomosis is required. A retrospective study was conducted in 74 patients who had undergone DIEP flap breast reconstruction. Patients were classified into two groups: SVA (single venous anastomosis) and DVA (dual venous anastomosis). In the SVA group (n = 38), the IMV antegrade limb was used for venous drainage. A single DIEV (Deep Inferior Epigastric Vein) was anastomosed to the superior arm of the IMV. In the DVA group (n = 36), both the antegrade (superior) and retrograde (inferior) stumps of the IMV were used, connecting the larger DIEV to the antegrade IMV and the other DIEV or the SIEV (Superficial Inferior Epigastric Vein) to the IMV retrograde limb. No venous congestion or flap loss was observed when two venous anastomoses were performed using both the IMV antegrade and retrograde limbs (P = 0.3271). In the DVA group, no major complication occurred (P = 0.0453). Operative explorations were significantly reduced in the DVA group (P = 0.0242). These findings suggest that when an additional venous outflow is required, the use of the IMV retrograde limb may help to avoid flap venous congestion. © 2016 Wiley Periodicals, Inc. Microsurgery 36:447-452, 2016. © 2016 Wiley Periodicals, Inc.

A Case of Traumatic Retrograde Type A Aortic Dissection Accompanied by Multiorgan Injuries.

PubMed

Tsukioka, Katsuaki; Kono, Tetsuya; Takahashi, Kohei; Kehara, Hiromu; Urashita, Shuichi; Komatsu, Kazunori

2018-03-25

A 75-year-old woman was involved in a traffic accident and suffered retrograde type A aortic dissection, multiple rib fractures, and grade II hepatic injury accompanied by intraperitoneal bleeding. We performed total arch replacement using an open stent graft with cardiopulmonary bypass and circulatory arrest. This procedure requires anticoagulation and hypothermia, which are principally contraindicated in severe trauma patients. However, this situation was resolved by managing the patient non-operatively for 7 days, confirming the stabilization of other injured organs, and then performing the surgery. She required prolonged postoperative rehabilitation; however, she recovered steadily.

Anterograde and retrograde amnesia in a person with bilateral fornix lesions following removal of a colloid cyst.

PubMed

Poreh, Amir; Winocur, Gordon; Moscovitch, Morris; Backon, Matti; Goshen, Elinor; Ram, Zvi; Feldman, Zeev

2006-01-01

AD, a 45-year-old man, presented with a severe and global anterograde amnesia following surgery for removal of a colloid cyst. Structural neuroimaging confirmed bilateral lesions to the fornix and a small lesion in the basal forebrain. Testing for remote episodic memory of autobiographical events, and for remote semantic memory of personal and public events, and of famous people, revealed that AD had a severe retrograde amnesia for autobiographical episodes that covered his entire lifetime, and a time-limited retrograde amnesia for semantic memory. Because the fornix and basal forebrain lesions disrupted major afferent and efferent pathways of the hippocampus, it was concluded that the integrity of the hippocampus and its projections are needed to retain and/or recover autobiographical memories no matter how old they are. By contrast, hippocampal contribution to semantic memory is time-limited. These findings were interpreted as consistent with Multiple Trace Theory, which holds that the hippocampal system is essential for recovering contextually rich memories no matter how old they are, but is not needed for recovering semantic memories.

Aβ1-42 triggers the generation of a retrograde signaling complex from sentinel mRNAs in axons.

PubMed

Walker, Chandler A; Randolph, Lisa K; Matute, Carlos; Alberdi, Elena; Baleriola, Jimena; Hengst, Ulrich

2018-05-14

Neurons frequently encounter neurodegenerative signals first in their periphery. For example, exposure of axons to oligomeric Aβ 1-42 is sufficient to induce changes in the neuronal cell body that ultimately lead to degeneration. Currently, it is unclear how the information about the neurodegenerative insult is transmitted to the soma. Here, we find that the translation of pre-localized but normally silenced sentinel mRNAs in axons is induced within minutes of Aβ 1-42 addition in a Ca 2+ -dependent manner. This immediate protein synthesis following Aβ 1-42 exposure generates a retrograde signaling complex including vimentin. Inhibition of the immediate protein synthesis, knock-down of axonal vimentin synthesis, or inhibition of dynein-dependent transport to the soma prevented the normal cell body response to Aβ 1-42 These results establish that CNS axons react to neurodegenerative insults via the local translation of sentinel mRNAs encoding components of a retrograde signaling complex that transmit the information about the event to the neuronal soma. © 2018 The Authors.

Utility of the Anterior Oblique-Viewing Endoscope and the Double-Balloon Enteroscope for Endoscopic Retrograde Cholangiopancreatography in Patients with Billroth II Gastrectomy

PubMed Central

Sen-yo, Manabu; Kaino, Seiji; Suenaga, Shigeyuki; Uekitani, Toshiyuki; Yoshida, Kanako; Harano, Megumi; Sakaida, Isao

2012-01-01

Background/Purpose. The difficulties of endoscopic retrograde cholangiopancreatography in patients with Billroth II gastrectomy have been reported. We evaluated the usefulness of an anterior oblique-viewing endoscope and a double-balloon enteroscope for endoscopic retrograde cholangiopancreatography in such patients. Methods. From January 2003 to December 2011, 65 patients with Billroth II gastrectomy were enrolled in this study. An anterior oblique-viewing endoscope was used for all patients. From February 2007, a double-balloon enteroscope was used for the failed cases. The success rate of procedures was compared with those in 20 patients with Billroth II gastrectomy using forward-viewing endoscope or side-viewing endoscope from March 1996 to July 2002 as historical controls. Results. In all patients in whom the papilla was reached (60/65), selective cannulation was achieved. The success rate of selective cannulation and accomplishment of planned procedures in the anterior oblique-viewing endoscope group were both significantly higher than that in the control group (100% versus 70.1%, 100 versus 58.8%, resp.). A double-balloon enteroscope was used in 2 patients, and the papilla could be reached and the planned procedures completed. Conclusions. An anterior oblique-viewing endoscope and double-balloon enteroscope appear to be useful in performing endoscopic retrograde cholangiopancreatography in patients with Billroth II gastrectomy. PMID:23056039

Episodic future thinking and future-based decision-making in a case of retrograde amnesia.

PubMed

De Luca, Flavia; Benuzzi, Francesca; Bertossi, Elena; Braghittoni, Davide; di Pellegrino, Giuseppe; Ciaramelli, Elisa

2018-02-01

We investigated episodic future thinking (EFT) and future-based cognition and decision-making in patient SG, who developed a dense retrograde amnesia following hypoxia due to a cardiac arrest. Despite intact general cognitive and executive functioning, SG was unable to remember events from his entire lifetime. He had, however, relatively spared anterograde memory and general semantic knowledge. Voxel-based morphometry detected a reduction of gray matter in the thalamus, cerebellum and fusiform gyrus bilaterally, and, at a reduced threshold, in several regions of the autobiographical memory network, including the hippocampi. We show that SG is unable to imagine personal future events, but can imagine fictitious events not self-relevant and not located in subjective time. Despite severely impaired EFT, SG shows normal attitudes towards the future time, and normal delay discounting rates. These findings suggest that retrieval of autobiographical information from long-term memory is necessary for EFT. However, relatively spared anterograde memory and general semantic knowledge may be sufficient to allow construction of fictitious experiences. As well, EFT is not necessary to drive future-oriented cognition and choice. These findings highlight the relation between autobiographical memory and EFT, and the fractionation of human temporal consciousness. Moreover, they contribute to our understanding of retrograde amnesia as an impairment of memory as well as future thinking. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fully Burdened Cost of Retrograde, Redeployment, Reconstitution, and Reset and Analysis of Alternatives (FBCR4 & AoA): New Model to Formulate Strategic Decisions for Deployed Ground Vehicle Equipment

DTIC Science & Technology

2012-11-05

key leadership of critical R4 cost analysis. The second objective is to equip DoD planners with the framework for solving retrograde dilemmas in...informing key leadership of critical R4 cost analysis. The second objective is to equip DoD planners with the framework for solving retrograde...replicate the same dedication to individuals in similar situations in years to come.  To Captains Aaron Burciaga, Mario Solano, and Maro Enoka, as well

Assessing Intrarenal Non-perfusion and Vascular Leakage in Acute Kidney Injury withzz 19F MRI and Perfluorocarbon Nanoparticles

PubMed Central

Hu, Lingzhi; Chen, Junjie; Yang, Xiaoxia; Senpan, Angana; Allen, John S.; Yanaba, Noriko; Caruthers, Shelton D.; Lanza, Gregory M.; Hammerman, Marc R.; Wickline, Samuel A.

2014-01-01

Purpose We sought to develop a unique sensor-reporter approach for functional kidney imaging that employs circulating perfluorocarbon nanoparticles (PFC NPs) and 19F MRI. Methods Because the detected 19F signal intensity directly reflects local blood volume, and the 19F R1 is linearly proportional to local blood oxygen content (pO2), 19F spin density weighted and T1 weighted images were utilized to generate quantitative functional mapping in both healthy and ischemia-reperfusion (acute kidney injury, AKI) injured mouse kidneys. 1H Blood-Oxygenation-Level-Dependant (BOLD) MRI was also employed as a supplementary approach to facilitate the compressive analysis of renal circulation and its pathological changes in AKI. Results Heterogeneous blood volume distribution and intrarenal oxygenation gradient were confirmed in healthy kidneys by 19F MRI. In a mouse model of AKI, 19F MRI, in conjunction with BOLR MRI, sensitively delineated renal vascular damage and recovery. In the cortico-medullary (CM) junction region, we observed 25% lower 19F signal (p<0.05) and 70% longer 1H T2* (p<0.01) in injured kidneys compared to contralateral kidneys at 24 hours after initial ischemia-reperfusion injury. We also detected 71% higher 19F signal (p<0.01) and 40% lower 1H T2* (p<0.05) in the renal medulla region of injured kidneys compared to contralateral kidneys. Conclusion With demonstrated superior diagnostic capability, functional kidney 19F MRI using PFC NPs could serve as a new diagnostic measures for comprehensive evaluation of renal function and pathology. PMID:23929727

Regulation of Synaptic Amyloid-β Generation through BACE1 Retrograde Transport in a Mouse Model of Alzheimer's Disease

PubMed Central

Ye, Xuan; Chang, Qing; Jeong, Yu Young; Cai, Huaibin; Kusnecov, Alexander

2017-01-01

Amyloid-β (Aβ) peptides play a key role in synaptic damage and memory deficits in the early pathogenesis of Alzheimer's disease (AD). Abnormal accumulation of Aβ at nerve terminals leads to synaptic pathology and ultimately to neurodegeneration. β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) is the major neuronal β-secretase for Aβ generation. However, the mechanisms regulating BACE1 distribution in axons and β cleavage of APP at synapses remain largely unknown. Here, we reveal that dynein–Snapin-mediated retrograde transport regulates BACE1 trafficking in axons and APP processing at presynaptic terminals. BACE1 is predominantly accumulated within late endosomes at the synapses of AD-related mutant human APP (hAPP) transgenic (Tg) mice and patient brains. Defective retrograde transport by genetic ablation of snapin in mice recapitulates late endocytic retention of BACE1 and increased APP processing at presynaptic sites. Conversely, overexpressing Snapin facilitates BACE1 trafficking and reduces synaptic BACE1 accumulation by enhancing the removal of BACE1 from distal AD axons and presynaptic terminals. Moreover, elevated Snapin expression via stereotactic hippocampal injections of adeno-associated virus particles in mutant hAPP Tg mouse brains decreases synaptic Aβ levels and ameliorates synapse loss, thus rescuing cognitive impairments associated with hAPP mice. Altogether, our study provides new mechanistic insights into the complex regulation of BACE1 trafficking and presynaptic localization through Snapin-mediated dynein-driven retrograde axonal transport, thereby suggesting a potential approach of modulating Aβ levels and attenuating synaptic deficits in AD. SIGNIFICANCE STATEMENT β-Site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) trafficking and synaptic localization significantly influence its β secretase activity and amyloid-β (Aβ) production. In AD brains, BACE1 is accumulated within dystrophic neurites, which

Retrograde and antegrade cerebral perfusion: results in short elective arch reconstructive times.

PubMed

Milewski, Rita Karianna; Pacini, Davide; Moser, G William; Moeller, Patrick; Cowie, Doreen; Szeto, Wilson Y; Woo, Y Joseph; Desai, Nimesh; Di Marco, Luca; Pochettino, Alberto; Di Bartolomeo, Roberto; Bavaria, Joseph E

2010-05-01

Debate remains regarding optimal cerebral circulatory management during relatively noncomplex, short arch reconstructive times. Both retrograde cerebral perfusion with deep hypothermic circulatory arrest (RCP/DHCA) and antegrade cerebral perfusion with moderate hypothermic circulatory arrest (ACP/MHCA) have emerged as established techniques. The aim of the study was to evaluate perioperative outcomes between antegrade and retrograde cerebral perfusion techniques for elective arch reconstruction times less than 45 minutes. Between 1997 and September 2008, 776 cases from two institutions were reviewed to compare RCP/DHCA and ACP/MHCA perfusion techniques. At the University of Pennsylvania, 682 were treated utilizing RCP/DHCA cerebral protection. At the University of Bologna, 94 were treated with ACP/MHCA and bilateral cerebral perfusion. Mean cerebral ischemic time and visceral ischemic time differed between RCP/DHCA and ACP/MHCA (p < 0.001). Multivariate analysis showed age more than 65 years, atherosclerotic aneurysm, and cross-clamp time as predictors of the composite endpoint of mortality, neurologic event, and acute myocardial infarction. There was no significant difference in permanent neurologic deficit, temporary neurologic dysfunction, or renal failure, between RCP/DHCA and ACP/MHCA. Mortality was comparable across both techniques. Both RCP/DHCA and ACP/MHCA have emerged as effective techniques for selected aortic arch operations with low morbidity and mortality. Univariate analysis revealed no statistically significant differences in primary or secondary outcomes between techniques for aortic reconstruction times less than 45 minutes. Data from this study demonstrate that selective use of either RCP/DHCA or ACP/MHCA provides excellent cerebral and visceral outcomes for elective open aortic surgery with short arch reconstructive times. Copyright (c) 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Integrated omics analyses of retrograde signaling mutant delineate interrelated stress-response strata.

PubMed

Bjornson, Marta; Balcke, Gerd Ulrich; Xiao, Yanmei; de Souza, Amancio; Wang, Jin-Zheng; Zhabinskaya, Dina; Tagkopoulos, Ilias; Tissier, Alain; Dehesh, Katayoon

2017-07-01

To maintain homeostasis in the face of intrinsic and extrinsic insults, cells have evolved elaborate quality control networks to resolve damage at multiple levels. Interorganellar communication is a key requirement for this maintenance, however the underlying mechanisms of this communication have remained an enigma. Here we integrate the outcome of transcriptomic, proteomic, and metabolomics analyses of genotypes including ceh1, a mutant with constitutively elevated levels of both the stress-specific plastidial retrograde signaling metabolite methyl-erythritol cyclodiphosphate (MEcPP) and the defense hormone salicylic acid (SA), as well as the high MEcPP but SA deficient genotype ceh1/eds16, along with corresponding controls. Integration of multi-omic analyses enabled us to delineate the function of MEcPP from SA, and expose the compartmentalized role of this retrograde signaling metabolite in induction of distinct but interdependent signaling cascades instrumental in adaptive responses. Specifically, here we identify strata of MEcPP-sensitive stress-response cascades, among which we focus on selected pathways including organelle-specific regulation of jasmonate biosynthesis; simultaneous induction of synthesis and breakdown of SA; and MEcPP-mediated alteration of cellular redox status in particular glutathione redox balance. Collectively, these integrated multi-omic analyses provided a vehicle to gain an in-depth knowledge of genome-metabolism interactions, and to further probe the extent of these interactions and delineate their functional contributions. Through this approach we were able to pinpoint stress-mediated transcriptional and metabolic signatures and identify the downstream processes modulated by the independent or overlapping functions of MEcPP and SA in adaptive responses. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Delusion of inanimate doubles: description of a case of focal retrograde amnesia.

PubMed

Abbate, Carlo; Trimarchi, Pietro Davide; Salvi, Gian Pietro; Quarenghi, Anna Maria; Vergani, Carlo; Luzzatti, Claudio

2012-01-01

This paper reports the case of a patient, M.P., who developed delusion of inanimate doubles, without Capgras syndrome, after traumatic brain injury. His delusional symptoms were studied longitudinally and the cognitive impairments associated with delusion were investigated. Data suggest that M.P. did 'perceive' the actual differences between doubles and originals rather than 'confabulate' them. The cognitive profile, characterized by retrograde episodic amnesia, but neither object processing impairment nor confabulations, supports this hypothesis. The study examines the nature of object misidentification based on Ellis' and Staton's account and proposes a new account based on concurrent unbiased retrieval of semantic memory traces and biased recollection of episodic memory traces.

[Changes in proline-specific peptidase activity in experimental model of retrograde amnesia].

PubMed

Nazarova, G A; Zolotov, N N; Krupina, N A; Kraĭneva, V A; Garibova, T L; Voronina, T A

2007-01-01

Changes in proline-specific peptidase activity in the frontal cortex and hippocampus were studied using the experimental model of retrograde amnesia in rats. In one group, the amnesia was produced by a single injection of M-cholinergic antagonist scopolamine and the other group received the maximal electroconvulsive stimulation (MES). The amnesic effect was evaluated in passive avoidance test. In the amnesia models under consideration, the activity of prolylendopeptidase was significantly increased in both frontal cortex and hippocampus. The activity of dipeptidyl peptidase IV was significantly decreased in the cortex, whereas in the hippocampus it remained unchanged. Pyracetam inhibited prolylendopeptidase in the cortex and hippocampus, whereas dipeptidyl peptidase IV activity remained unchanged.

Retrograde traffic from the Golgi to the endoplasmic reticulum.

PubMed

Spang, Anne

2013-06-01

Proteins to be secreted are transported from the endoplasmic reticulum (ER) to the Golgi apparatus. The transport of these proteins requires the localization and activity of proteins that create ER exit sites, coat proteins to collect cargo and to reshape the membrane into a transport container, and address labels--SNARE proteins--to target the vesicles specifically to the Golgi apparatus. In addition some proteins may need export chaperones or export receptors to enable their exit into transport vesicles. ER export factors, SNAREs, and misfolded Golgi-resident proteins must all be retrieved from the Golgi to the ER again. This retrieval is also part of the organellar homeostasis pathway essential to maintaining the identity of the ER and of the Golgi apparatus. In this review, I will discuss the different processes in retrograde transport from the Golgi to the ER and highlight the mechanistic insights we have obtained in the last couple of years.

Retrograde Traffic from the Golgi to the Endoplasmic Reticulum

PubMed Central

Spang, Anne

2013-01-01

Proteins to be secreted are transported from the endoplasmic reticulum (ER) to the Golgi apparatus. The transport of these proteins requires the localization and activity of proteins that create ER exit sites, coat proteins to collect cargo and to reshape the membrane into a transport container, and address labels—SNARE proteins—to target the vesicles specifically to the Golgi apparatus. In addition some proteins may need export chaperones or export receptors to enable their exit into transport vesicles. ER export factors, SNAREs, and misfolded Golgi-resident proteins must all be retrieved from the Golgi to the ER again. This retrieval is also part of the organellar homeostasis pathway essential to maintaining the identity of the ER and of the Golgi apparatus. In this review, I will discuss the different processes in retrograde transport from the Golgi to the ER and highlight the mechanistic insights we have obtained in the last couple of years. PMID:23732476

An interstellar origin for Jupiter's retrograde co-orbital asteroid

NASA Astrophysics Data System (ADS)

Namouni, F.; Morais, M. H. M.

2018-06-01

Asteroid (514107) 2015 BZ509 was discovered recently in Jupiter's co-orbital region with a retrograde motion around the Sun. The known chaotic dynamics of the outer Solar system have so far precluded the identification of its origin. Here, we perform a high-resolution statistical search for stable orbits and show that asteroid (514107) 2015 BZ509 has been in its current orbital state since the formation of the Solar system. This result indicates that (514107) 2015 BZ509 was captured from the interstellar medium 4.5 billion years in the past as planet formation models cannot produce such a primordial large-inclination orbit with the planets on nearly coplanar orbits interacting with a coplanar debris disc that must produce the low-inclination small-body reservoirs of the Solar system such as the asteroid and Kuiper belts. This result also implies that more extrasolar asteroids are currently present in the Solar system on nearly polar orbits.

An Arabidopsis mitochondria-localized RRL protein mediates abscisic acid signal transduction through mitochondrial retrograde regulation involving ABI4.

PubMed

Yao, Xuan; Li, Juanjuan; Liu, Jianping; Liu, Kede

2015-10-01

The molecular mechanisms of abscisic acid (ABA) signalling have been studied for many years; however, how mitochondria-localized proteins play roles in ABA signalling remains unclear. Here an Arabidopsis mitochondria-localized protein RRL (RETARDED ROOT GROWTH-LIKE) was shown to function in ABA signalling. A previous study had revealed that the Arabidopsis mitochondria-localized protein RRG (RETARDED ROOT GROWTH) is required for cell division in the root meristem. RRL shares 54% and 57% identity at the nucleotide and amino acid sequences, respectively, with RRG; nevertheless, RRL shows a different function in Arabidopsis. In this study, disruption of RRL decreased ABA sensitivity whereas overexpression of RRL increased ABA sensitivity during seed germination and seedling growth. High expression levels of RRL were found in germinating seeds and developing seedlings, as revealed by β-glucuronidase (GUS) staining of ProRRL-GUS transgenic lines. The analyses of the structure and function of mitochondria in the knockout rrl mutant showed that the disruption of RRL causes extensively internally vacuolated mitochondria and reduced ABA-stimulated reactive oxygen species (ROS) production. Previous studies have revealed that the expression of alternative oxidase (AOX) in the alternative respiratory pathway is increased by mitochondrial retrograde regulation to regain ROS levels when the mitochondrial electron transport chain is impaired. The APETALA2 (AP2)-type transcription factor ABI4 is a regulator of ALTERNATIVE OXIDASE1a (AOX1a) in mitochondrial retrograde signalling. This study showed that ABA-induced AOX1a and ABI4 expression was inhibited in the rrl mutant, suggesting that RRL is probably involved in ABI4-mediated mitochondrial retrograde signalling. Furthermore, the results revealed that ABI4 is a downstream regulatory factor in RRL-mediated ABA signalling in seed germination and seedling growth. © The Author 2015. Published by Oxford University Press on behalf of

Intrathecal Bupivacaine Monotherapy with a Retrograde Catheter for the Management of Complex Regional Pain Syndrome of the Lower Extremity.

PubMed

McRoberts, W Porter; Apostol, Catalina; Haleem, Abdul

2016-01-01

Complex regional pain syndrome (CRPS) presents a therapeutic challenge due to its many presentations and multifaceted pathophysiology. There is no approved treatment algorithm and clinical interventions are often applied empirically. In cases of CRPS where symptoms are localized to an extremity, a targeted treatment is indicated. We describe the use of intrathecal bupivacaine monotherapy, delivered through a retrograde catheter, in the treatment of CRPS affecting the lower extremity. The patient, a 57-year-old woman with a history of failed foot surgery, was seen in our office after 2 years of ineffective treatments with local blocks and neurolytic procedures. We advanced therapy to moderately invasive procedures with an emphasis on neuromodulation. A combined central and peripheral stimulation technique that initially provided 75% pain relief, failed to provide lasting analgesia. We proceeded with an intrathecal pump implant. Based on the results of dorsal root ganglion (DRG) mapping, L5-S1 was identified as the optimal target for therapy and a retrograde catheter was placed at this level. Various intrathecal medications were tested individually. An intrathecal morphine trial was ineffective (visual analog scale [VAS] 7), while intrathecal clonidine provided excellent pain relief (VAS 0) that was limited by severe side effects. Bupivacaine provided 100% analgesia with tolerable side effects (lower extremity weakness and minor bladder incontinence) and was selected for intrathecal infusion. After 14 months, bupivacaine treatment continued to control pain exacerbations. We conclude that CRPS patients benefit from early identification of the predominant underlying symptoms and a targeted treatment with moderately invasive techniques when less invasive techniques fail. Intrathecal bupivacaine, bupivacaine monotherapy, retrograde catheter, complex regional pain syndrome (CRPS), dual stimulation, dosal root ganglion (DRG) testing.

Structurally optimized analogs of the retrograde trafficking inhibitor Retro-2cycl limit Leishmania infections.

PubMed

Craig, Evan; Huyghues-Despointes, Charles-Eugene; Yu, Chun; Handy, Emma L; Sello, Jason K; Kima, Peter E

2017-05-01

In infected mammalian cells, Leishmania parasites reside within specialized compartments called parasitophorous vacuoles (LPVs). We have previously shown that Retro-2, a member of a novel class of small retrograde pathway inhibitors caused reduced LPV sizes and lower parasite numbers during experimental L. mexicana sp. infections. The purpose of this study was to determine if structural analogs of Retro-2cycl reported to have superior potency in the inhibition of retrograde pathway-dependent phenomena (i.e., polyomavirus cellular infection by polyomavrius and Shiga toxin trafficking in cells) are also more effective than the parent compound at controlling Leishmania infections. In addition to their effects on LPV development, we show that two optimized analogs of Retro-2cycl, DHQZ 36 and DHQZ 36.1 limit Leishmania amazonensis infection in macrophages at EC50 of 13.63+/-2.58μM and10.57+/-2.66μM, respectively, which is significantly lower than 40.15μM the EC50 of Retro-2cycl. In addition, these analogs caused a reversal in Leishmania induced suppression of IL-6 release by infected cells after LPS activation. Moreover, we show that in contrast to Retro-2cycl that is Leishmania static, the analogs can kill Leishmania parasites in axenic cultures, which is a desirable attribute for any drug to treat Leishmania infections. Together, these studies validate and extend the published structure-activity relationship analyses of Retro-2cycl.

Tibiotalocalcaneal arthrodesis with a compressive retrograde intramedullary nail: a report of 34 consecutive patients.

PubMed

Niinimäki, Tuukka Timo; Klemola, Tero-Matti; Leppilahti, Juhana Ilmari

2007-04-01

Tibiotalocalcaneal arthrodesis is a treatment modality for severe arthrosis and malalignment of the hindfoot. Complications, such as delayed union and nonunion, are well-known risks of the procedure. Arthrodesis can be done with a plate, screws, an external fixator, or an intramedullary nail. Compression with an intramedullary nail was the focus of this report. Thirty-four consecutive patients (23 men and 11 women) with an average age range of 57 (range 25-77) years had tibiotalocalcaneal arthrodesis using retrograde intramedullary compression nail fixation. Mean followup was 24 (range 6 to 43) months. One patient died of an unrelated cause, but 30 (91%) of the remaining 33 patients answered the questionnaire. Bony consolidation was achieved in 26 (76%) patients, the mean time to fusion being 16 weeks. Five patients (15%) had complications and seven (20%) had repeat surgery. Of the 30 patients who responded to the questionnaire, three patients (10%) evaluated the overall result subjectively as being of no benefit and 27 (90%) as improved. The visual analog scale (VAS) score for preoperative pain was 66 at rest and 83 when walking, and the mean postoperative scores were 19 and 32, respectively (p<0.001). Tibiotalocalcaneal arthrodesis with a compressive retrograde intramedullary nail is an effective and safe procedure for patients with severe malalignment or arthrosis of the hindfoot. It is essentially a salvage procedure, and most patients benefit from it, but excellent results are rare.

Dync1h1 Mutation Causes Proprioceptive Sensory Neuron Loss and Impaired Retrograde Axonal Transport of Dorsal Root Ganglion Neurons.

PubMed

Zhao, Jing; Wang, Yi; Xu, Huan; Fu, Yuan; Qian, Ting; Bo, Deng; Lu, Yan-Xin; Xiong, Yi; Wan, Jun; Zhang, Xiang; Dong, Qiang; Chen, Xiang-Jun

2016-07-01

Sprawling (Swl) is a radiation-induced mutation which has been identified to have a nine base pair deletion in dynein heavy chain 1 (DYNC1H1: encoded by a single gene Dync1h1). This study is to investigate the phenotype and the underlying mechanism of the Dync1h1 mutant. To display the phenotype of Swl mutant mice, we examined the embryos of homozygous (Swl/Swl) and heterozygous (Swl/+) mice and their postnatal dorsal root ganglion (DRG) of surviving Swl/+ mice. The Swl/+ mice could survive for a normal life span, while Swl/Swl could only survive till embryonic (E) 8.5 days. Excessive apoptosis of Swl/+ DRG neurons was revealed during E11.5-E15.5 days, and the peak rate was at E13.5 days. In vitro study of mutated DRG neurons showed impaired retrograde transport of dynein-driven nerve growth factor (NGF). Mitochondria, another dynein-driven cargo, demonstrated much slower retrograde transport velocity in Swl/+ neurons than in wild-type (WT) neurons. Nevertheless, the Swl, Loa, and Cra mutations did not affect homodimerization of DYNC1H1. The Swl/Swl mutation of Dync1h1 gene led to embryonic mal-development and lethality, whereas the Swl/+ DRG neurons demonstrated deficient retrograde transport in dynein-driven cargos and excessive apoptosis during mid- to late-developmental stages. The underlying mechanism of the mutation may not be due to impaired homodimerization of DYNC1H1. © 2016 John Wiley & Sons Ltd.

Structural optimization of a retrograde trafficking inhibitor that protects cells from infections by human polyoma- and papillomaviruses.

PubMed

Carney, Daniel W; Nelson, Christian D S; Ferris, Bennett D; Stevens, Julia P; Lipovsky, Alex; Kazakov, Teymur; DiMaio, Daniel; Atwood, Walter J; Sello, Jason K

2014-09-01

Human polyoma- and papillomaviruses are non-enveloped DNA viruses that cause severe pathologies and mortalities. Under circumstances of immunosuppression, JC polyomavirus causes a fatal demyelinating disease called progressive multifocal leukoencephalopathy (PML) and the BK polyomavirus is the etiological agent of polyomavirus-induced nephropathy and hemorrhagic cystitis. Human papillomavirus type 16, another non-enveloped DNA virus, is associated with the development of cancers in tissues like the uterine cervix and oropharynx. Currently, there are no approved drugs or vaccines to treat or prevent polyomavirus infections. We recently discovered that the small molecule Retro-2(cycl), an inhibitor of host retrograde trafficking, blocked infection by several human and monkey polyomaviruses. Here, we report diversity-oriented syntheses of Retro-2(cycl) and evaluation of the resulting analogs using an assay of human cell infections by JC polyomavirus. We defined structure-activity relationships and also discovered analogs with significantly improved potency as suppressors of human polyoma- and papillomavirus infection in vitro. Our findings represent an advance in the development of drug candidates that can broadly protect humans from non-enveloped DNA viruses and toxins that exploit retrograde trafficking as a means for cell entry. Copyright © 2014 Elsevier Ltd. All rights reserved.

Selective labeling of retinal ganglion cells with calcium indicators by retrograde loading in vitro

PubMed Central

Behrend, Matthew R.; Ahuja, Ashish K.; Humayun, Mark S.; Weiland, James D.; Chow, Robert H.

2012-01-01

Here we present a retrograde loading technique that makes it possible for the first time to rapidly load a calcium indicator in the majority of retinal ganglion cells (RGCs) in salamander retina, and then to observe physiological activity of these dye-loaded cells. Dextran-conjugated calcium indicator, dissolved in water, was applied to the optic nerve stump. Following dye loading, the isolated retina was mounted on a microelectrode array to demonstrate that electrical activity and calcium activity were preserved, as the retina responded to electrical stimuli. PMID:19428523

Conservative Management of an Epicardial Collateral Perforation During Retrograde Chronic Total Occlusion Percutaneous Coronary Intervention.

PubMed

Ngo, Christian; Christopoulos, George; Brilakis, Emmanouil S

2016-01-01

Coronary artery perforation is a highly feared complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) and can lead to pericardial effusion, tamponade, and, rarely, emergent cardiac surgery. Perforation of epicardial collaterals during retrograde CTO-PCI may be particularly challenging to treat, as embolization from both sides of the perforation may be required to control the bleeding. However, conservative measures can occasionally be effective. We present a case of epicardial collateral vessel perforation that was managed conservatively with anticoagulation reversal.

Heterotopic ossification of the elbow after closed reduction and retrograde intramedullary nailing for radial neck fracture treated by anconeus interposition.

PubMed

Sreenivas, T; Menon, Jagdish; Nataraj, A R

2013-12-01

Heterotopic ossification around the elbow can lead to considerable functional disability. We describe a case of a 42-year-old man who developed heterotopic ossification of his elbow after closed reduction of the elbow dislocation and radial neck fracture and retrograde intramedullary nailing for radial neck fracture. During the follow-up after initial surgery, movements of the elbow were gradually deteriorated and diagnosed as heterotopic ossification of the elbow. Implant removal, radial head excision along with heterotopic mass, and also interposition of the anconeus muscle resulted in improvement of his elbow mobility. At 18 months of follow-up, patient had elbow flexion arc of 15°-110°, 70° of supination, and 50° of pronation without recurrence of heterotopic ossification. The uniqueness of this case lies in the treatment of heterotopic ossification of the elbow to prevent its recurrence, which was developed after retrograde intramedullary nailing for radial neck fracture following closed reduction.

Activities in a social networking-based discussion group by endoscopic retrograde cholangiopancreatography doctors.

PubMed

Kang, Xiaoyu; Zhao, Lina; Liu, Na; Wang, Xiangping; Zhang, Rongchun; Liu, Zhiguo; Liang, Shuhui; Yao, Shaowei; Tao, Qin; Jia, Hui; Pan, Yanglin; Guo, Xuegang

2017-10-01

Online social networking is increasingly being used among medical practitioners. However, few studies have evaluated its use in therapeutic endoscopy. Here, we aimed to analyze the shared topics and activities of a group of endoscopic retrograde cholangiopancreatography (ERCP) doctors in a social networking-based endoscopic retrograde cholangiopancreatography discussion group (EDG). Six ERCP trainers working in Xijing Hospital and 48 graduated endoscopists who had finished ERCP training in the same hospital were invited to join in EDG. All group members were informed not to divulge any private information of patients when using EDG. The activities of group members on EDG were retrospectively extracted. The individual data of the graduated endoscopists were collected by a questionnaire. From June 2014 to May 2015, 6924 messages were posted on EDG, half of which were ERCP related. In total, 214 ERCP-related topics were shared, which could be categorized into three types: sharing experience/cases (52.3%), asking questions (38.3%), and sharing literatures/advances (9.3%). Among the 48 graduated endoscopists, 21 had a low case volume of less than 50 per year and 27 had a high volume case volume of 50 or more. High-volume graduated endoscopists posted more ERCP-related messages (P=0.008) and shared more discussion topics (P=0.003) compared with low-volume graduated endoscopists. A survey showed that EDG was useful for graduated endoscopists in ERCP performance and management of post-ERCP complications, etc. A wide range of ERCP-related topics were shared on the social networking-based EDG. The ERCP-related behaviors on EDG were more active in graduated endoscopists with an ERCP case volume of more than 50 per year.

Retrograde Endopyelotomy with Cutting Balloon™ for Treatment of Ureteropelvic Junction Obstruction in Infants.

PubMed

Parente, Alberto; Perez-Egido, Laura; Romero, Rosa Maria; Ortiz, Ruben; Burgos, Laura; Angulo, Jose Maria

2016-01-01

The aim of this study is to analyze results of retrograde endopyelotomy with cutting balloon for treatment of ureteropelvic junction obstruction (UPJO) in infants. We routinely treat patients with UPJO under 18 months of age with retrograde high-pressure balloon dilatation of the pelviureteric junction (PUJ). During the procedure, in these cases where narrowing at the PUJ persists, endopyelotomy with cutting balloon is performed. Endopyelotomy is performed over guidewire with 5-mm Cutting Balloon™ under fluoroscopic control. Double-J stents is left in situ for 4 weeks. We retrospectively analyzed the postoperative, clinical, and radiological outcome infants treated with cutting balloon endopyelotomy between 2007 and 2015. Sixteen patients required cutting balloon endopyelotomy to achieve complete resolution of narrowing of the waist observed during high-pressure balloon dilatation of the PUJ. Mean operative time was 35 ± 21 min (mean ± SD) and hospital stay was <24 h in all patients. Complete resolution of the narrowing at the PUJ under fluoroscopy was achieved in all cases, with no perioperative complications. One patient presented with urinary tract infection, postoperatively (Clavien grade II). Preoperatively, all cases had grade IV SFU hydronephrosis with parenchymal thinning. During follow-up, resolution of the hydronephrosis was observed in 11 patients (grade I SFU). In four infants, there was an improvement of the hydronephrosis (grade II SFU) and the renogram curve. In one case, an open pyeloplasty was required due to persistent hydronephrosis and obstructive curve. We believe that endopyelotomy with cutting balloon could be a valid and safe option in minimally invasive management of UPJO in infants.

A TOCA/CDC-42/PAR/WAVE functional module required for retrograde endocytic recycling.

PubMed

Bai, Zhiyong; Grant, Barth D

2015-03-24

Endosome-to-Golgi transport is required for the function of many key membrane proteins and lipids, including signaling receptors, small-molecule transporters, and adhesion proteins. The retromer complex is well-known for its role in cargo sorting and vesicle budding from early endosomes, in most cases leading to cargo fusion with the trans-Golgi network (TGN). Transport from recycling endosomes to the TGN has also been reported, but much less is understood about the molecules that mediate this transport step. Here we provide evidence that the F-BAR domain proteins TOCA-1 and TOCA-2 (Transducer of Cdc42 dependent actin assembly), the small GTPase CDC-42 (Cell division control protein 42), associated polarity proteins PAR-6 (Partitioning defective 6) and PKC-3/atypical protein kinase C, and the WAVE actin nucleation complex mediate the transport of MIG-14/Wls and TGN-38/TGN38 cargo proteins from the recycling endosome to the TGN in Caenorhabditis elegans. Our results indicate that CDC-42, the TOCA proteins, and the WAVE component WVE-1 are enriched on RME-1-positive recycling endosomes in the intestine, unlike retromer components that act on early endosomes. Furthermore, we find that retrograde cargo TGN-38 is trapped in early endosomes after depletion of SNX-3 (a retromer component) but is mainly trapped in recycling endosomes after depletion of CDC-42, indicating that the CDC-42-associated complex functions after retromer in a distinct organelle. Thus, we identify a group of interacting proteins that mediate retrograde recycling, and link these proteins to a poorly understood trafficking step, recycling endosome-to-Golgi transport. We also provide evidence for the physiological importance of this pathway in WNT signaling.

Retrograde Semaphorin-Plexin Signaling Drives Homeostatic Synaptic Plasticity

PubMed Central

Orr, Brian O.; Fetter, Richard D.; Davis, Graeme W.

2017-01-01

Homeostatic signaling systems ensure stable, yet flexible neural activity and animal behavior1–4. Defining the underlying molecular mechanisms of neuronal homeostatic signaling will be essential in order to establish clear connections to the causes and progression of neurological disease. Presynaptic homeostatic plasticity (PHP) is a conserved form of neuronal homeostatic signaling, observed in organisms ranging from Drosophila to human1,5. Here, we demonstrate that Semaphorin2b (Sema2b) is target-derived signal that acts upon presynaptic PlexinB (PlexB) receptors to mediate the retrograde, homeostatic control of presynaptic neurotransmitter release at the Drosophila neuromuscular junction. Sema2b-PlexB signaling regulates the expression of PHP via the cytoplasmic protein Mical and the oxoreductase-dependent control of presynaptic actin6,7. During neural development, Semaphorin-Plexin signaling instructs axon guidance and neuronal morphogenesis8–10. Yet, Semaphorins and Plexins are also expressed in the adult brain11–16. Here we demonstrate that Semaphorin-Plexin signaling controls presynaptic neurotransmitter release. We propose that Sema2b-PlexB signaling is an essential platform for the stabilization of synaptic transmission throughout life. PMID:28953869

Approach for chronic total occlusion with intravascular ultrasound-guided reverse controlled antegrade and retrograde tracking technique: single center experience.

PubMed

Dai, Jian; Katoh, Osamu; Kyo, Eisho; Tsuji, Takafumi; Watanabe, Satoshi; Ohya, Hidefumi

2013-10-01

Controlled antegrade and retrograde subintimal tracking (CART) or reverse CART techniques is the final step for percutaneous revascularization of coronary chronic total occlusion (CTO), but it still represents technical challenges and risk in interventional procedures. Our purpose was to utilize intravascular ultrasound (IVUS)-guided reverse CART approach for percutaneous revascularization of CTO in our heart center, focusing on its safety, efficacy, and latest technical developments. From November 2006 to November 2012, 49 patients with CTO failed to antegrade and/or retrograde percutaneous revascularization of CTO from true lumen to true lumen were enrolled in and underwent IVUS guided reverse CART approach. The mean J-CTO score of cases was 2.5. IVUS guidance was successfully implemented in 95.9%; IVUS identified that 61.7% of retrograde wires were located at intimal space, and 59.5% of antegrade wires were located at subintimal space. A Corsair channel dilator was used in 77.6% of cases. The success rates of technique and procedure were 95.9% and 93.9%, respectively; the technical minor complications were observed in 10.2% of cases, without significant clinic outcomes; 2.0% of cases occurred with a major adverse cardiac event of non-ST-elevation myocardial infarction; and no case occurred with target vessel revascularization or death. The mean length of stent implanted in a single CTO vessel was 51.3 mm. No patient appeared with radiation dermatitis and contrast-induced rise of creatinine. IVUS guided reverse CART approach is effective and safe for percutaneous revascularization of complex CTO, with a high success and a low complication rate. It is feasible to develop this approach for percutaneous revascularization of complex CTO. However, suitable case selection and lately device handling by experienced operators are the crucial points of success. © 2013, Wiley Periodicals, Inc.

Vascularized Pedicled Fibula Onlay Bone Graft Augmentation for Complicated Tibiotalocalcaneal Arthrodesis With Retrograde Intramedullary Nail Fixation: A Case Series.

PubMed

Roukis, Thomas S; Kang, Rachel B

2016-01-01

Tibiotalocalcaneal arthrodesis stabilized with retrograde intramedullary nail fixation is associated with a high incidence of complications. This is especially true when performed with a bulk structural allograft and poor soft tissue quality. In select high-risk limb salvage cases, we have augmented tibiotalocalcaneal arthrodesis procedures stabilized using retrograde intramedullary nail fixation with a vascularized pedicled fibular onlay bone graft. We present the data from 10 such procedures with a mean follow-up period of 10.9 ± 5.4 (range 6 to 20) months involving 10 patients (9 males and 1 female). The etiology was avascular osteonecrosis of the talus and/or distal tibia and a resultant large volume cavitary bone defect (8 ankles), severe equinocavovarus contracture (1 ankle), and failed total ankle replacement (1 ankle). A frozen femoral head bulk allograft was used twice, a whole frozen talus allograft once, and a freeze-dried calcaneal allograft once. The fibula was mobilized with intact musculoperiosteal perforating branches of the peroneal artery as a vascularized pedicle onlay bone graft fixated with a screw and washer construct. The mean fibular graft length was 10.2 ± 2.3 cm. The mean interval to radiographic fusion was 2.6 ± 0.6 months and to weightbearing was 3.1 ± 1.4 months. Two stable bulk allograft-host bone and fibular graft-host bone nonunions occurred after intramedullary nail hardware failure. Tibiotalocalcaneal arthrodesis augmented by vascularized pedicled fibular graft stabilized with retrograde compression intramedullary nail fixation offers a reliable option for complex salvage situations when few other options exist. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Behavioral and functional neuroanatomical correlates of anterograde autobiographical memory in isolated retrograde amnesic patient M.L.

PubMed

Levine, Brian; Svoboda, Eva; Turner, Gary R; Mandic, Marina; Mackey, Allison

2009-09-01

Patient M.L. [Levine, B., Black, S. E., Cabeza, R., Sinden, M., Mcintosh, A. R., Toth, J. P., et al. (1998). Episodic memory and the self in a case of isolated retrograde amnesia. Brain, 121, 1951-1973], lost memory for events occurring before his severe traumatic brain injury, yet his anterograde (post-injury) learning and memory appeared intact, a syndrome known as isolated or focal retrograde amnesia. Studies with M.L. demonstrated a dissociation between episodic and semantic memory. His retrograde amnesia was specific to episodic autobiographical memory. Convergent behavioral and functional imaging data suggested that his anterograde memory, while appearing normal, was accomplished with reduced autonoetic awareness (awareness of the self as a continuous entity across time that is a crucial element of episodic memory). While previous research on M.L. focused on anterograde memory of laboratory stimuli, in this study, M.L.'s autobiographical memory for post-injury events or anterograde autobiographical memory was examined using prospective collection of autobiographical events via audio diary with detailed behavioral and functional neuroanatomical analysis. Consistent with his reports of subjective disconnection from post-injury autobiographical events, M.L. assigned fewer "remember" ratings to his autobiographical events than comparison subjects. His generation of event-specific details using the Autobiographical Interview [Levine, B., Svoboda, E., Hay, J., Winocur, G., & Moscovitch, M. (2002). Aging and autobiographical memory: dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677-689] was low, but not significantly so, suggesting that it is possible to generate episodic-like details even when re-experiencing of those details is compromised. While listening to the autobiographical audio diary segments, M.L. showed reduced activation relative to comparison subjects in midline frontal and posterior nodes previously identified as part of the

Plug-Assisted Retrograde Transvenous Obliteration for the Treatment of Gastric Varices: The Role of Intra-Procedural Cone-Beam Computed Tomography

PubMed Central

Ko, Gi-Young; Kwon, Young Baek; Yoon, Hyun-Ki; Sung, Kyu-Bo

2018-01-01

Objective To investigate the technical and clinical outcomes of plug-assisted retrograde transvenous obliteration (PARTO) for the treatment of gastric varices (GV) and to evaluate the role of intra-procedural cone-beam computed tomography (CBCT) performed during PARTO to confirm its technical success. Materials and Methods From January 2016 to December 2016, 17 patients with GV who had undergone PARTO were retrospectively evaluated. When the proximal part of the afferent vein was identified on a fluoroscopy, non-contrast CBCT images were obtained. In patients with incomplete embolization of GV, an additional injection of gelatin sponges was performed. Follow-up data from contrast-enhanced CT and upper intestinal endoscopy, as well as clinical and laboratory data were collected. Results Plug-assisted retrograde transvenous obliteration procedures were technically successful in all 17 patients. Complete embolization of GV was detected on CBCT images in 15 patients; whereas, incomplete embolization was detected in two. Complete embolization of GV was then achieved after an additional injection of gelatin sponges in these two patients as demonstrated on the 2nd CBCT image. The mean follow-up period after PARTO was 193 days (range, 73–383 days). A follow-up CT obtained 2–4 months after PARTO demonstrated marked shrinkage or complete obliteration of GV and portosystemic shunts in all 17 patients. There were no cases of variceal bleeding during the follow-up. Conclusion Plug-assisted retrograde transvenous obliteration is technically and clinically effective for the treatment of GV. In addition, intra-procedural CBCT can be an adjunct tool to fluoroscopy, because it can provide an immediate and accurate evaluation of the technical success of PARTO. PMID:29520179

Rhynchophylline Ameliorates Endothelial Dysfunction via Src-PI3K/Akt-eNOS Cascade in the Cultured Intrarenal Arteries of Spontaneous Hypertensive Rats

PubMed Central

Hao, Hui-Feng; Liu, Li-Mei; Pan, Chun-Shui; Wang, Chuan-She; Gao, Yuan-Sheng; Fan, Jing-Yu; Han, Jing-Yan

2017-01-01

Objectives: To examine the protective effect of Rhynchophylline (Rhy) on vascular endothelial function in spontaneous hypertensive rats (SHRs) and the underlying mechanism. Methods: Intrarenal arteries of SHRs and Wistar rats were suspended in myograph for force measurement. Expression and phosphorylation of endothelial nitric oxide (NO) synthase (eNOS), Akt, and Src kinase (Src) were examined by Western blotting. NO production was assayed by ELISA. Results: Rhy time- and concentration-dependently improved endothelium-dependent relaxation in the renal arteries from SHRs, but had no effect on endothelium-independent relaxation in SHR renal arteries. Wortmannin (an inhibitor of phosphatidylinositol 3-kinase) or PP2 (an inhibitor of Src) inhibited the improvement of relaxation in response to acetylcholine by 12 h-incubation with 300 μM Rhy. Western blot analysis revealed that Rhy elevated phosphorylations of eNOS, Akt, and Src in SHR renal arteries. Moreover, wortmannin reversed the increased phosphorylations of Akt and eNOS induced by Rhy, but did not affect the phosphorylation of Src. Furthermore, the enhanced phosphorylations of eNOS, Akt, and Src were blunted by PP2. Importantly, Rhy increased NO production and this effect was blocked by inhibition of Src or PI3K/Akt. Conclusion: The present study provides evidences for the first time that Rhy ameliorates endothelial dysfunction in SHRs through the activation of Src-PI3K/Akt-eNOS signaling pathway. PMID:29187825

Definition of a core module for the nuclear retrograde response to altered organellar gene expression identifies GLK overexpressors as gun mutants.

PubMed

Leister, Dario; Kleine, Tatjana

2016-07-01

Retrograde signaling can be triggered by changes in organellar gene expression (OGE) induced by inhibitors such as lincomycin (LIN) or mutations that perturb OGE. Thus, an insufficiency of the organelle-targeted prolyl-tRNA synthetase PRORS1 in Arabidopsis thaliana activates retrograde signaling and reduces the expression of nuclear genes for photosynthetic proteins. Recently, we showed that mTERF6, a member of the so-called mitochondrial transcription termination factor (mTERF) family, is involved in the formation of chloroplast (cp) isoleucine-tRNA. To obtain further insights into its functions, co-expression analysis of MTERF6, PRORS1 and two other genes for organellar aminoacyl-tRNA synthetases was conducted. The results suggest a prominent role of mTERF6 in aminoacylation activity, light signaling and seed storage. Analysis of changes in whole-genome transcriptomes in the mterf6-1 mutant showed that levels of nuclear transcripts for cp OGE proteins were particularly affected. Comparison of the mterf6-1 transcriptome with that of prors1-2 showed that reduced aminoacylation of proline (prors1-2) and isoleucine (mterf6-1) tRNAs alters retrograde signaling in similar ways. Database analyses indicate that comparable gene expression changes are provoked by treatment with LIN, norflurazon or high light. A core OGE response module was defined by identifying genes that were differentially expressed under at least four of six conditions relevant to OGE signaling. Based on this module, overexpressors of the Golden2-like transcription factors GLK1 and GLK2 were identified as genomes uncoupled mutants. © 2016 Scandinavian Plant Physiology Society.

Effect of Retrograde Reaming for Tibiotalocalcaneal Arthrodesis on Subtalar Joint Destruction: A Cadaveric Study.

PubMed

Lowe, Jason A; Routh, Lucas K; Leary, Jeffrey T; Buzhardt, Paul C

2016-01-01

Recent published data have suggested successful union of subtalar and tibiotalar joints without formal debridement during tibiotalocalcaneal (TTC) fusion procedures. Although previous studies have reported on the importance of the proper guidewire starting point and trajectory to obtain appropriate hindfoot alignment for successful fusion, to our knowledge, no studies have quantified the amount of articular damage to the subtalar joint with retrograde reaming. We hypothesized that reaming would destroy >50% of the posterior facet of the subtalar joint. The bilateral lower extremities of 5 cadavers were obtained and the subtalar joints exposed. Retrograde TTC nail guidewires were inserted, and a 12-mm reamer was passed through the subtalar and ankle joints. Pre- and postreaming images of the subtalar joint were obtained to compare the amount of joint destruction after reaming. We found an average of 5.89% articular destruction of the talar posterior facet and an average of 4.01% articular destruction of the posterior facet of the calcaneus. No damage to the middle facets of the subtalar joint was observed. TTC nailing is a successful procedure for ankle and subtalar joint fusion. Published studies have reported successful subtalar union using TTC nailing without formal open debridement of the subtalar joint, preserving the soft tissue envelope. TTC nail insertion using a 12-mm reamer will destroy 5.89% and 4.01% of the respective talar and calcaneal posterior facets of the subtalar joint. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Distant retrograde orbits and the asteroid hazard

NASA Astrophysics Data System (ADS)

Perozzi, Ettore; Ceccaroni, Marta; Valsecchi, Giovanni B.; Rossi, Alessandro

2017-08-01

Distant Retrograde Orbits (DROs) gained a novel wave of fame in space mission design because of their numerous advantages within the framework of the US plans for bringing a large asteroid sample in the vicinity of the Earth as the next target for human exploration. DROs are stable solutions of the three-body problem that can be used whenever an object, whether of natural or artificial nature, is required to remain in the neighborhood of a celestial body without being gravitationally captured by it. As such, they represent an alternative option to Halo orbits around the collinear Lagrangian points L1 and L2. Also known under other names ( e.g., quasi-satellite orbits, cis-lunar orbits, family- f orbits) these orbital configurations found interesting applications in several mission profiles, like that of a spacecraft orbiting around the small irregularly shaped satellite of Mars Phobos or the large Jovian moon Europa. In this paper a basic explanation of the DRO dynamics is presented in order to clarify some geometrical properties that characterize them. Their accessibility is then discussed from the point of view of mission analysis under different assumptions. Finally, their relevance within the framework of the present asteroid hazard protection programs is shown, stressing the significant increase in warning time they would provide in the prediction of impactors coming from the direction of the Sun.

Is local anesthesia the optimum strategy in retrograde transcatheter aortic valve implantation? A systematic review and meta-analysis.

PubMed

O' Sullivan, Katie E; Bracken-Clarke, Darragh; Segurado, Ricardo; Barry, Mitchel; Sugrue, Declan; Flood, Georgina; Hurley, John

2014-09-01

Retrograde transcatheter aortic valve implantation (TAVI) can be performed under local anesthesia (LA) or general anesthesia (GA); however, a wide variation in practice exists. PubMed was searched between 2009 and 2013. Data were extracted from eligible studies. Random-effects meta-analysis was performed using DerSimonian Laird between-study variance. There was no statistically significant difference identified between groups based on age or EuroSCORE. There was no statistically significant difference seen in all-cause mortality, or complication rates between groups. Mean procedural duration was 36 minutes shorter in the LA group (p = 0.001). There was increased vasopressor use in the GA group (odds ratio 3.92; p = 0.017). Mean hospital stay was 3.41 days shorter in the LA group (p = 0.018). Results suggest that the use of LA for retrograde TAVI is feasible. There are several potential benefits associated, shorter procedural duration, and hospital stay with lower vasopressor requirements. Further studies and randomized trials are mandatory to confirm the presented findings and to identify those patients for whom LA would be appropriate. Georg Thieme Verlag KG Stuttgart · New York.

A Case of Persistent Generalized Retrograde Autobiographical Amnesia Subsequent to the Great East Japan Earthquake in 2011.

PubMed

Odagaki, Yuji

2017-01-01

Functional retrograde autobiographical amnesia is often associated with physical and/or psychological trauma. On 11 March 2011, the largest earthquake on record in Japan took place, and subsequent huge tsunami devastated the Pacific coast of northern Japan. This case report describes a patient suffering from retrograde episodic-autobiographical amnesia for whole life, persisting for even more than five years after the disaster. A Japanese man, presumably in his 40s, got police protection in April 2016 but was unable to respond to question about his own name. He lost all information about his personal identity, and his memory was wholly lost until the disaster on 11 March 2011. He was able to recall his life after the disaster, and semantic memories and social abilities were largely preserved. A medical examination performed on 1 November 2016 verified that he was awake, alert, and oriented to time, place, and person (except for himself). General physical and neurological examinations revealed no pathological findings. He also experienced some symptoms associated with posttraumatic stress disorder (PTSD), such as intrusive thoughts, flashbacks, and nightmares. No abnormalities were detected by biochemical test and brain magnetic resonance imaging (MRI). Physicians and other professionals who take care of victims of disaster should be aware of dissociative spectrum disorders, such as psychogenic amnesia.

A retrograde y-stenting of the trachea for treatment of mediastinal fistula in an unusual situation

PubMed Central

Hohenforst-Schmidt, Wolfgang; Zarogoulidis, Paul; Steinheimer, Michael; Schneider, Thomas; Benhassen, Naim; Rupprecht, Holger; Freitag, Lutz

2017-01-01

Introduction Stents have been used for quite some time for the treatment of benign and malignant airway stenosis. Silicon stents are preferred for benign situations, whereas metallic self-expanding stents are preferred for malignant comorbidities. Patient and methods In general, stents can be placed in different approach directions, although in pulmonary medicine it is logical to apply only antegrade techniques – until now. A 63-year-old patient, 168 cm height and 53 kg weight on referral, suffered chronical diseases. The patient was diagnosed with a papillary thyroid carcinoma in 1989, which was treated by resection and radiotherapy. In the following years, she developed a stenosis of the esophagus. The decision to try endobronchial stenting was made upon the plan to close that fistula with a pedicled omentum majus replacement through the diaphragmal opening of the esophagus. This surgical plastic needed an abutment and a secured continuous airway replacement above the tracheostoma level. A Freitag stent (FS), 11 cm in length (110–25–40) and an inner diameter of 13 mm, was placed successfully retrograde into the trachea and completely bridged the big fistula. Unfortunately the patient passed away due to pulmonary infections after several weeks. Discussion In this case report, a successful but unusual case of retrograde stent placement of a modified FS is presented. PMID:28579789

Military Readiness: DOD Needs to Incorporate Elements of a Strategic Management Planning Framework into Retrograde and Reset Guidance

DTIC Science & Technology

2016-05-01

purpose of the memo is to provide additional guidance to the DOD components for submission of data and justification material supporting their estimates...and Reset Guidance Report to Congressional Committees May 2016 GAO-16-414 United States Government Accountability Office United States...Incorporate Elements of a Strategic Management Planning Framework into Retrograde and Reset Guidance Why GAO Did This Study Following the end of major

An unusual case of prolonged post-endoscopic retrograde cholangiopancreatography jaundice.

PubMed

Tziatzios, Georgios; Gkolfakis, Paraskevas; Papanikolaou, Ioannis S; Dimitriadis, George; Triantafyllou, Konstantinos

2016-04-01

Despite the effectiveness of endoscopic retrograde cholangiopancreatography (ERCP) for the treatment of choledocholithiasis, various complications have been described. We herein report the first case of prolonged post-ERCP jaundice due to toxicity of the contrast agent Iobitridol (®XENETIX, Guerbet, Roissy CdG Cedex, France) in a patient who underwent ERCP with sphincterectomy and common bile duct stone removal. While clinical improvement and normalization of aminotransferases and cholestatic enzymes after the procedure, an unexplained increase of direct bilirubin was noticed. A second ERCP was performed one week later, excluding possible remaining choledocholithiasis. Nevertheless, serum direct bilirubin increased further up to 15 mg/dL. Other potential causes of direct hyperbilirubinemia were ruled out and patient's liver biopsy was compatible with drug-induced liver toxicity. Additionally, the cause-result time connection between the use of Iobitridol and bilirubin increase indicated the possibility of a toxic effect related to the repeated use of the particular contrast agent. Iobitridol, a contrast agent, can induce prolonged direct hyperbilirubinemia.

Eye lens exposure to medical staff during endoscopic retrograde cholangiopancreatography.

PubMed

Zagorska, A; Romanova, K; Hristova-Popova, J; Vassileva, J; Katzarov, K

2015-11-01

The paper presents a study of the radiation doses to eye lens of medical staff during endoscopic retrograde cholangiopancreatography (ERCP) procedures performed in a busy gastroenterology department. For each procedure the dose equivalent to the eye, exposure time, dose rate, Kerma Area Product and fluoroscopy time were recorded. Measurements were performed for a period of two months in four main positions of the operating staff, and then extrapolated to estimate annual doses. The fluoroscopy time per ERCP procedure varied between 1.0 min and 28.8 min, with a mean value of 4.6 min. The calculated mean eye dose per procedure varied between 34.9 μSv and 93.3 μSv. The results demonstrated that if eye protection is not used, annual doses to the eye lens of the gastroenterologist performing the procedure and the anesthesiologist can exceed the dose limit of 20 mSv per year. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Retrograde intubation: an alternative way for the management of difficult airway.

PubMed

Lama, P; Shrestha, B R

2008-01-01

Inserting a retrograde wire into the pharynx through a cricothyroid puncture can facilitate tracheal intubation in difficult situations where either a flexible fiber-optic bronchoscope or an expert user of such a device is not available. Even in cases when fibropric can not be negotiated for the purpose, this method has been claimed to be useful to manage the airway. Some mouth opening is essential for the oral or nasal retrieval of the wire from the pharynx. Here, a case of post mandibular reconstructed wound infection required surgical debridement and plate removal from reconstructed lower mandible under general anesthesia. We retrieved the guide wire passed through a cricothyroid puncture and subsequently accomplished wire-guided oro-tracheal intubation. In the absence of a flexible fiber-optic bronchoscope, this technique is a very useful aid to intubate patients with limited mouth opening.

Combination of diOlistic labeling with retrograde tract tracing and immunohistochemistry.

PubMed

Neely, M Diana; Stanwood, Gregg D; Deutch, Ariel Y

2009-11-15

Neuronal staining techniques have played a crucial role in the analysis of neuronal function. Several different staining techniques have been developed to allow morphological analyses of neurons. DiOlistic labeling, in which beads are coated with a lipophilic dye and then ballistically ejected onto brain tissue, has recently been introduced as a useful and simple means to label neurons and glia in their entirety. Although diOlistic labeling provides detailed information on the morphology of neurons, combining this approach with other staining methods is a significant advance. We have developed protocols that result in high quality diOlistically- and retrogradely-labeled or diOlistically-immunohistochemically labeled neurons. These dual-label methods require modification of fixation parameters and the restricted use of detergents for tissue permeabilization, and are readily applicable to a wide range of tracers and antibodies.

Combination of DiOlistic Labeling with Retrograde Tract Tracing and Immunohistochemistry

PubMed Central

Diana Neely, M.; Stanwood, Gregg D; Deutch, Ariel Y.

2009-01-01

Neuronal staining techniques have played a crucial role in the analysis of neuronal function. Several different staining techniques have been developed to allow morphological analyses of neurons. Recently diOlistic labeling, in which beads are coated with a lipophilic dye and then ballistically ejected onto brain tissue, has been developed as a useful and simple means to label neurons and glia in their entirety. Although diOlistic labeling provides detailed information on the morphology of neurons, combining this approach with other staining methods is a significant advance. We have developed protocols that result in high quality diOlistically- and retrogradely-labeled or diOlistically-immunohistochemically labeled neurons. These dual-label methods require modification of fixation parameters and the use of detergents for tissue permeabilization, and are readily applicable to a wide range of tracers and antibodies. PMID:19712695

Effect of tempol and tempol plus catalase on intra-renal haemodynamics in spontaneously hypertensive stroke-prone (SHSP) and Wistar rats.

PubMed

Ahmeda, Ahmad F; Rae, Mark G; Al Otaibi, Mohammed F; Anweigi, Lamyia M; Johns, Edward J

2017-05-01

Vasoconstriction within the renal medulla contributes to the development of hypertension. This study investigated the role of reactive oxygen species (ROS) in regulating renal medullary and cortical blood perfusion (MBP and CBP respectively) in both stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar rats. CBP and MBP were measured using a laser-Doppler flow meter before and after intra-renal infusion of tempol, the superoxide dismutase (SOD) mimetic or tempol plus catalase, the hydrogen peroxide-degrading enzyme. Tempol infusion significantly elevated blood perfusion within the renal medulla (MBP) in both SHRSP (by 43 ± 7%, P < 0.001) and Wistar rats (by 17 ± 2%, P < 0.05) but the magnitude of the increase was significantly greater in the SHRSP (P < 0.01). When the enzyme catalase and tempol were co-infused, MBP was again significantly increased in SHRSP (by 57 ± 6%, P < 0.001) and Wistar rats (by 33 ± 6%, P < 0.001), with a significantly greater increase in perfusion being induced in the SHRSP relative to the Wistar rats (P < 0.01). Notably, this increase was significantly greater than in those animals infused with tempol alone (P < 0.01). These results suggest that ROS plays a proportionally greater role in reducing renal vascular compliance, particularly within the renal medulla, in normotensive and hypertensive animals, with effects being greater in the hypertensive animals. This supports the hypothesis that SHRSP renal vasculature might be subjected to elevated level of oxidative stress relative to normotensive animals.

Prevention of Retrograde Blood Flow Into Large or Giant Internal Carotid Artery Aneurysms by Endovascular Coil Embolization with High-Flow Bypass: Surgical Technique and Long-Term Results.

PubMed

Nakajima, Norio; Nagahiro, Shinji; Satomi, Junichiro; Tada, Yoshiteru; Nakajima, Kohei; Sogabe, Shu; Hanaoka, Mami; Matsubara, Shunji; Uno, Masaaki; Satoh, Koichi

2015-06-01

Recanalization has been reported in large or giant aneurysms of the internal carotid artery (ICA) addressed by high-flow bypass and endovascular treatment. Aneurysmal recanalization may be attributable to retrograde blood flow into the aneurysm through the ICA branches, such as the ophthalmic artery or the meningohypophyseal trunk, or through the surgically created bypass. We modified the endovascular treatment of aneurysms to prevent retrograde flow and evaluated the long-term efficacy of our method. We used a hybrid operative/endovascular technique to treat 5 patients with large or giant aneurysms arising from the C2-C4 segment of the ICA who presented with visual symptoms due to the mass effect of the aneurysm. To prevent retrograde flow into the aneurysm our modified endovascular treatment involves coil embolization of the aneurysmal orifice and the ICA, including the origin of the ophthalmic artery and meningohypophyseal trunk, and placement of a high-flow bypass using a radial artery graft. During the 5- to 12-year follow-up period, 4 aneurysms disappeared, and the other decreased in size. There were no subarachnoid hemorrhages. All bypass grafts remained patent. Visual preservation was achieved in 2 patients; 1 patient manifested visual improvement. Although 2 patients experienced transient neurological deficits we encountered no permanent complications in this series. The final modified Rankin scale of the 5 patients was 0 or 1. Prevention of retrograde flow into the aneurysm by coil embolization with high-flow bypass is a safe and effective method. It prevents the recanalization of large or giant ICA aneurysms. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Sodium butyrate suppresses angiotensin II-induced hypertension by inhibition of renal (pro)renin receptor and intrarenal renin-angiotensin system.

PubMed

Wang, Lei; Zhu, Qing; Lu, Aihua; Liu, Xiaofen; Zhang, Linlin; Xu, Chuanming; Liu, Xiyang; Li, Haobo; Yang, Tianxin

2017-09-01

Butyrate, a short-chain fatty acid, is the end product of the fermentation of complex carbohydrates by the gut microbiota. Recently, sodium butyrate (NaBu) has been found to play a protective role in a number of chronic diseases. However, it is still unclear whether NaBu has a therapeutic potential in hypertension. The present study was aimed to investigate the role of NaBu in angiotensin II (Ang II)-induced hypertension and to further explore the underlying mechanism. Ang II was infused into uninephrectomized Sprague-Dawley rats with or without intramedullary infusion of NaBu for 14 days. Mean arterial blood pressure was recorded by the telemetry system. Renal tissues, serum samples, and 24-h urine samples were collected to examine renal injury and the regulation of the (pro)renin receptor (PRR) and renin. Intramedullary infusion of NaBu in Sprague-Dawley rats lowered the Ang II-induced mean arterial pressure from 129 ± 6 mmHg to 108 ± 4 mmHg (P < 0.01). This corresponded with an improvement in Ang II-induced renal injury, including urinary albumin, glomerulosclerosis, and renal fibrosis, as well as the expression of inflammatory mediators tumor necrosis factor α, interleukin 6. The renal expression of PRR, angiotensinogen, angiotensin I-converting enzyme and the urinary excretion of soluble PRR, renin, and angiotensinogen were all increased by Ang II infusion but decreased by NaBu treatment. In cultured innermedullary collecting duct cells, NaBu treatment attenuated Ang II-induced expression of PRR and renin. These results demonstrate that NaBu exerts an antihypertensive action, likely by suppressing the PRR-mediated intrarenal renin-angiotensin system.

A TOCA/CDC-42/PAR/WAVE functional module required for retrograde endocytic recycling

PubMed Central

Bai, Zhiyong; Grant, Barth D.

2015-01-01

Endosome-to-Golgi transport is required for the function of many key membrane proteins and lipids, including signaling receptors, small-molecule transporters, and adhesion proteins. The retromer complex is well-known for its role in cargo sorting and vesicle budding from early endosomes, in most cases leading to cargo fusion with the trans-Golgi network (TGN). Transport from recycling endosomes to the TGN has also been reported, but much less is understood about the molecules that mediate this transport step. Here we provide evidence that the F-BAR domain proteins TOCA-1 and TOCA-2 (Transducer of Cdc42 dependent actin assembly), the small GTPase CDC-42 (Cell division control protein 42), associated polarity proteins PAR-6 (Partitioning defective 6) and PKC-3/atypical protein kinase C, and the WAVE actin nucleation complex mediate the transport of MIG-14/Wls and TGN-38/TGN38 cargo proteins from the recycling endosome to the TGN in Caenorhabditis elegans. Our results indicate that CDC-42, the TOCA proteins, and the WAVE component WVE-1 are enriched on RME-1–positive recycling endosomes in the intestine, unlike retromer components that act on early endosomes. Furthermore, we find that retrograde cargo TGN-38 is trapped in early endosomes after depletion of SNX-3 (a retromer component) but is mainly trapped in recycling endosomes after depletion of CDC-42, indicating that the CDC-42–associated complex functions after retromer in a distinct organelle. Thus, we identify a group of interacting proteins that mediate retrograde recycling, and link these proteins to a poorly understood trafficking step, recycling endosome-to-Golgi transport. We also provide evidence for the physiological importance of this pathway in WNT signaling. PMID:25775511

Cerebral and Renal Oxygen Saturation Are Not Compromised in the Presence of Retrograde Blood Flow in either the Ascending or Descending Aorta in Term or Near-Term Infants with Left-Sided Obstructive Lesions.

PubMed

van der Laan, Michelle E; Mebius, Mirthe J; Roofthooft, Marcus T R; Bos, Arend F; Berger, Rolf M F; Kooi, Elisabeth M W

2017-01-01

In infants with left-sided obstructive lesions (LSOL), the presence of retrograde blood flow in either the ascending or descending aorta may lead to diminished cerebral and renal blood flow, respectively. Our aim was to compare cerebral and renal tissue oxygen saturation (rSO2) between infants with LSOL with antegrade and retrograde blood flow in the ascending aorta and with and without diastolic backflow in the descending aorta. Based on 2 echocardiograms, the study group was categorized according to the direction of blood flow in the ascending and descending aorta. We measured cerebral and renal rSO2 using near-infrared spectroscopy and calculated fractional tissue oxygen extraction (FTOE). Nineteen infants with LSOL, admitted to the NICU between 0 and 28 days after birth, were included. Infants with antegrade blood flow (n = 12) and infants with retrograde blood flow in the ascending aorta (n = 7) had similar cerebral rSO2 and FTOE during both echocardiograms. Only during the first echocardiogram, infants with retrograde blood flow in the ascending aorta had lower renal FTOE (0.14 vs. 0.32, p = 0.04) and tended to have higher renal rSO2 (80 vs. 65%, p = 0.09). The presence of diastolic backflow in the descending aorta was not associated with cerebral or renal rSO2 and FTOE during the first (n = 8) as well as the second echocardiogram (n = 10). Retrograde blood flow in the ascending aorta was not associated with cerebral oxygenation, while diastolic backflow in the descending aorta was not associated with renal oxygenation in infants with LSOL. © 2017 S. Karger AG, Basel.

[The randomized controlled trial of the treatment for clavicular fracture by rotatory manual reduction with forceps holder and retrograde percutaneous pinning transfixation].

PubMed

Bi, Hong-zheng; Yang, Mao-qing; Tan, Yuan-chao; Fu, Song

2008-07-01

To study the curative effect and safety of rotatory manual reduction with forceps holder and retrograde percutaneous pinning transfixation in treating clavicular fracture. All 201 cases of clavicular fractures were randomly divided into treatment group (101 cases) and control group (100 cases). The treatment group was treated by rotatory manual reduction with forceps holder and retrograde percutaneous pinning transfixation. The control group was treated by open reduction and internal fixation with Kirschner pin. All cases were followed up for 4 to 21 months (mean 10.6 months). SPSS was used to analyze clinic healing time of fracture and shoulder-joint function in both two groups. After operation, 101 cases of treatment group achieved union of fracture and the clinical healing time was 28 to 49 days (mean 34.5+/-2.7 days). In control group,there were 4 cases with nonunion of fracture,the other 96 cases were union,the clinical healing time was 36 to 92 days (mean 55.3+/-4.8 days). The excellent and good rate of shoulder-joint function was 100% in treatment group and 83% in control group. By t-test and chi2-test, there was significant difference between the two groups in curative effect (P<0.05). Rotatory manual reduction with forceps holder and retrograde pinning transfixation can be used in various kinds of clavicular shaft fracture, with many virtues such as easy operation, reliable fixation, short union time of fracture, good functional recovery of shoulder-joint and no incision scar affecting appearance.

[Application of bone flap pedicled on retrograde branch of radial artery for treatment of old scaphoid bone fractures of type AO-B].

PubMed

Sun, Qing-peng

2015-05-01

To investigate application of the bone flap pedicled on the retrograde branch of radial artery for treatment of old scaphoid bone fractures of type AO-B. From October 2007 to October 2011,41 patients with old scaphoid bone fractures of type AO-B were treated by transplantation of the bone flap pedicled on the retrograde branch of radial artery including 26 males and 15 females with an average of (27.3±4.5) years old ranging from 16 to 43 years old. The courses before operation ranged from 6 to 22 months with an average of 11 months. All fractures belonged to the type B of AO classification, that is old wrist fracture of scaphoid bone. All patients' wrist function (pain, function, motion, grip strength) were evaluated by Cooney's modifiedwrist scoring system before and 6 months after operation,and the conditions of bone healing were observed during the follow-up time. Among them, 36 patients were followed up from 4 to 15 months with an average of 8.3 months. The wounds were healed well without other complications as infection appearing. X-rays or CT confirmed that all fractures were healed completely. The Cooney wrist score was improved from preoperative 53.61±13.97 to postoperative 81.81±8.71 (P<0.01). The operation of transplantation of the bone flap pedicled on the retrograde branch of radial artery is an effective method to treat old scaphoid bone fractures,which is scientific and has curative effects, and valuable for clinical application.

The effect of recombinant bone morphogenetic protein-2 in revision tibiotalocalcaneal arthrodesis: utilization of the Retrograde Arthrodesis Intramedullary Nail database.

PubMed

DeVries, J George; Nguyen, Minh; Berlet, Gregory C; Hyer, Christopher F

2012-01-01

The use of bone morphogenetic protein-2 (BMP-2) has been recommended for high-risk fusions and nonunion. Patients undergoing revisional tibiotalocalcaneal (TTC) arthrodesis via a retrograde arthrodesis nail to evaluate the influence of BMP-2 on rate of fusion in this high-risk population are presented. A retrospective chart and radiographic review were performed on 23 patients with failed prior fusion attempts at the ankle treated with retrograde intramedullary nailing. Sixteen patients were treated without BMP-2 (None group) and 7 were treated with BMP-2 (BMP group). The primary and secondary end-points were successful fusion, and time to fusion, respectively, with a variety of variables evaluated for influence. Other than the use of BMP-2, there were no statistical differences in the patient population. Overall, 11 of 16 ankles (68.8%) in the None group and 5 of 7 ankles (71.4%) in the BMP group resulted in a stable, functional limb. Rate of complication was similar between the 2 groups (p > .05). Time to radiographic ankle union was 115.2 and 184.0 days in the None and BMP groups (p > .05). The effect of BMP-2 on revisional TTC fusions with retrograde nails is reported here. The overall result as a stable, functional limb was 69.6%, which suggests that revision surgery in this high-risk population is a reasonable consideration. Even though this study was unable to demonstrate statistically significant differences, biologic augmentation with BMP-2 did not increase the complication rate and showed a slightly enhanced salvage rate for revision TTC fusions with an intramedullary nail. Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Earth-Mars transfers through Moon Distant Retrograde Orbits

NASA Astrophysics Data System (ADS)

Conte, Davide; Di Carlo, Marilena; Ho, Koki; Spencer, David B.; Vasile, Massimiliano

2018-02-01

This paper focuses on the trajectory design which is relevant for missions that would exploit the use of asteroid mining in stable cis-lunar orbits to facilitate deep space missions, specifically human Mars exploration. Assuming that a refueling "gas station" is present at a given lunar Distant Retrograde Orbit (DRO), ways of departing from the Earth to Mars via that DRO are analyzed. Thus, the analysis and results presented in this paper add a new cis-lunar departure orbit for Earth-Mars missions. Porkchop plots depicting the required C3 at launch, v∞ at arrival, Time of Flight (TOF), and total Δ V for various DRO departure and Mars arrival dates are created and compared with results obtained for low Δ V Low Earth Orbit (LEO) to Mars trajectories. The results show that propellant-optimal trajectories from LEO to Mars through a DRO have higher overall mission Δ V due to the additional stop at the DRO. However, they have lower Initial Mass in LEO (IMLEO) and thus lower gear ratio as well as lower TOF than direct LEO to Mars transfers. This results in a lower overall spacecraft dry mass that needs to be launched into space from Earth's surface.

Retrograde accretion of a Caribbean fringing reef controlled by hurricanes and sea-level rise

NASA Astrophysics Data System (ADS)

Blanchon, Paul; Richards, Simon; Bernal, Juan Pablo; Cerdeira-Estrada, Sergio; Ibarra, M. Socrates; Corona-Martínez, Liliana; Martell-Dubois, Raúl

2017-10-01

Predicting the impact of sea-level (SL) rise on coral reefs requires reliable models of reef accretion. Most assume that accretion results from vertical growth of coralgal framework, but recent studies show that reefs exposed to hurricanes consist of layers of coral gravel rather than in-place corals. New models are therefore needed to account for hurricane impact on reef accretion over geological timescales. To investigate this geological impact, we report the configuration and development of a 4-km-long fringing reef at Punta Maroma along the northeast Yucatan Peninsula. Satellite-derived bathymetry shows the crest is set-back a uniform distance of 315 ±15 m from a mid-shelf slope break, and the reef-front decreases 50% in width and depth along its length. A 12-core drill transect constrained by multiple 230Th ages shows the reef is composed of an 2-m thick layer of coral clasts that has retrograded 100 m over its back-reef during the last 5.5 ka. These findings are consistent with a hurricane-control model of reef development where large waves trip and break over the mid-shelf slope break, triggering rapid energy dissipation and thus limiting how far upslope individual waves can fragment corals and redistribute clasts. As SL rises and water depth increases, energy dissipation during wave-breaking is reduced, extending the clast-transport limit, thus leading to reef retrogradation. This hurricane model may be applicable to a large sub-set of fringing reefs in the tropical Western-Atlantic necessitating a reappraisal of their accretion rates and response to future SL rise.

Pancreatits after endoscopic retrograde cholangio-pancreatography

PubMed Central

Abdel Aziz, Ayman M; Lehman, Glen A

2007-01-01

Pancreatitis is the most common complication after endoscopic retrograde cholangio-pancreatography (ERCP); the reported incidence of this complication varies from less than 1% to 40%, but a rate of 4%-8% is reported in most prospective studies involving non-selected patients. Differences in criteria for defining pancreatitis, methods of data collection, and patient populations (i.e. number of high-risk patients included in the published series) are factors that are likely to affect the varying rates of post-ERCP pancreatitis. The severity of post-ERCP pancreatitis (PEP) can range from a minor inconvenience with one or two days of added hospitalization with full recovery to a devastating illness with pancreatic necrosis, multiorgan failure, permanent disability, and even death. Although, most episodes of PEP are mild (about 90%), a small percentage of patients (about 10%) develop moderate or severe pancreatitis. In the past, PEP was often viewed as an unpredictable and unavoidable complication, with no realistic strategy for its avoidance. New data have aided in stratification of patients into PEP risk categories and new measures have been introduced to decrease the risk of PEP. As most ERCPs are performed on an outpatient basis, the majority of patients will not develop PEP and can be discharged. Alternatively, early detection of those patients who will go on to develop PEP can guide decisions regarding hospital admission and aggressive management. In the last decade, great efforts have been addressed toward prevention of this complication. Points of emphasis have included technical measures, pharmacological prophylaxis, and patient selection. This review provides a comprehensive, evidence-based assessment of published data on PEP and current suggestions for its avoidance. PMID:17569133

Combination of intracellular staining of retrogradely labeled neurons and anterograde fluorescent tracing: use of the confocal laser scanning microscope.

PubMed

Shi, C; Cassell, M D

1993-04-01

This report describes a combined retrograde tracing, intracellular injection and anterograde fluorescence labeling method using the application of confocal laser scanning microscopy. By simultaneously viewing the morphology of identified projection neurons and the distribution of anterogradely labeled fibers and terminals, this approach allows accurate characterization of the anatomical relationships between these two elements. To demonstrate this approach, the retrograde tracer Fast Blue was injected into the bed nucleus of stria terminalis (BNST) and the anterograde tracer tetramethylrhodamine-conjugated dextran was injected into the insular cortex in adult rats. After one week survival time, the brains were fixed and sectioned on a vibratome. Individual BNST projecting neurons identified in the amygdaloid complex on 120 microns thick sections were intracellularly injected with Lucifer Yellow under visual control and analyzed with confocal laser scanning microscopy. The results demonstrate that images from very thin optical sections can clearly show potential synaptic contacts between anterograde labeling and intracellularly labeled projecting neurons. Stacked images from optical sections show, in very great detail, the morphology of projection neurons in three-dimensions. Compared to other methodological combinations, the present method provides a more simple and efficient means to trace three successive components of a putative neuron chain.

Inhibitors of retrograde trafficking active against ricin and Shiga toxins also protect cells from several viruses, Leishmania and Chlamydiales.

PubMed

Gupta, Neetu; Noël, Romain; Goudet, Amélie; Hinsinger, Karen; Michau, Aurélien; Pons, Valérie; Abdelkafi, Hajer; Secher, Thomas; Shima, Ayaka; Shtanko, Olena; Sakurai, Yasuteru; Cojean, Sandrine; Pomel, Sébastien; Liévin-Le Moal, Vanessa; Leignel, Véronique; Herweg, Jo-Ana; Fischer, Annette; Johannes, Ludger; Harrison, Kate; Beard, Philippa M; Clayette, Pascal; Le Grand, Roger; Rayner, Jonathan O; Rudel, Thomas; Vacus, Joël; Loiseau, Philippe M; Davey, Robert A; Oswald, Eric; Cintrat, Jean-Christophe; Barbier, Julien; Gillet, Daniel

2017-04-01

Medical countermeasures to treat biothreat agent infections require broad-spectrum therapeutics that do not induce agent resistance. A cell-based high-throughput screen (HTS) against ricin toxin combined with hit optimization allowed selection of a family of compounds that meet these requirements. The hit compound Retro-2 and its derivatives have been demonstrated to be safe in vivo in mice even at high doses. Moreover, Retro-2 is an inhibitor of retrograde transport that affects syntaxin-5-dependent toxins and pathogens. As a consequence, it has a broad-spectrum activity that has been demonstrated both in vitro and in vivo against ricin, Shiga toxin-producing O104:H4 entero-hemorrhagic E. coli and Leishmania sp. and in vitro against Ebola, Marburg and poxviruses and Chlamydiales. An effect is anticipated on other toxins or pathogens that use retrograde trafficking and syntaxin-5. Since Retro-2 targets cell components of the host and not directly the pathogen, no selection of resistant pathogens is expected. These lead compounds need now to be developed as drugs for human use. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Retrograde stapling of a free cervical jejunal interposition graft: a technical innovation and case report

PubMed Central

2014-01-01

Background Free jejunal interposition is a useful technique for reconstruction of the cervical esophagus. However, the distal anastomosis between the graft and the remaining thoracic esophagus or a gastric conduit can be technically challenging when located very low in the thoracic aperture. We here describe a modified technique for retrograde stapling of a jejunal graft to a failed gastric conduit using a circular stapler on a delivery system. Case presentation A 56 year-old patient had been referred for esophageal squamous cell carcinoma at 20 cm from the incisors. On day 8 after thoracoabdominal esophagectomy with gastric pull-up, an anastomotic leakage was diagnosed. A proximal-release stent was successfully placed by gastroscopy and the patient was discharged. Two weeks later, an esophagotracheal fistula occurred proximal to the esophageal stent. Cervical esophagostomy was performed with cranial closure of the gastric conduit, which was left in situ within the right hemithorax. Three months later, reconstruction was performed using a free jejunal interposition. The anvil of a circular stapler (Orvil®, Covidien) was placed transabdominally through an endoscopic rendez-vous procedure into the gastric conduit. A free jejunal graft was retrogradely stapled to the proximal end of the conduit. Microvascular anastomoses were performed subsequently. The proximal anastomosis of the conduit was completed manually after reperfusion. Conclusions This modified technique allows stapling of a jejunal interposition graft located deep in the thoracic aperture and is therefore a useful method that may help to avoid reconstruction by colonic pull-up and thoracotomy. PMID:25319372

[Obstructive cholangiopathy: are endoscopic retrograde cholangiopancreatography and papillotomy always really necessary?].

PubMed

Pierie, J P; van Vroonhoven, T J

1999-07-17

In two women aged 76 and 29 years, who presented with cholangitis and small ductus choledochus calculi and with painless icterus respectively, endoscopic retrograde cholangiopancreatography (ERCP) was carried out with papillotomy. Both developed a duodenal perforation which, however, could not be localized. The first patient eventually died, the second recovered after prolonged hospitalization. A third patient, a 53-year-old man, developed abdominal pain and fever four days after laparoscopic cholecystectomy. ERCP was planned, but in the meantime the patient showed signs of recovery. The ERCP was carried out nevertheless. It failed and the patient suffered a prolonged recovery with necrotizing pancreatitis and multiple operations necessitating a temporary colostoma. In all three patients the endoscopic procedure was performed routinely without strict individualized indication. ERCP and papillotomy may be relatively safe procedures, but it should always be considered whether they will really serve the patient.

Isosorbide, a green plasticizer for thermoplastic starch that does not retrogradate.

PubMed

Battegazzore, Daniele; Bocchini, Sergio; Nicola, Gabriele; Martini, Eligio; Frache, Alberto

2015-03-30

Isosorbide is a non-toxic biodegradable diol derived from bio-based feedstock. It can be used for preparing thermoplastic starch through a semi-industrial process of extrusion. Isosorbide allows some technological advantages with respect to classical plasticizers: namely, direct mixing with starch, energy savings for the low processing temperature required and lower water uptake. Indeed, maize starch was directly mixed with the solid plasticizer and direct fed in the main hopper of a co-rotating twin screw extruder. Starch plasticization was assessed by X-ray diffraction (XRD) and dynamic-mechanical analysis (DMTA). Oxygen permeability, water uptake and mechanical properties were measured at different relative humidity (R.H.) values. These three properties turned out to be highly depending on the R.H. No retrogradation and changing of the material properties were occurred from XRD and DMTA after 9 months. Copyright © 2014 Elsevier Ltd. All rights reserved.

Enkephalin-containing neurons in the inferior mesenteric ganglion projecting to the distal colon of cat: evidence from combined retrograde tracing by fluorescent microspheres and immunohistochemistry.

PubMed

Bagnol, D; Jule, Y; Kirchner, G; Cupo, A; Roman, C

1993-02-01

Retrograde tracing with rhodamine fluorescent microspheres combined with fluorescein immunolabelling of methionine-enkephalin showed the presence of enkephalin-like material in neurons of the inferior mesenteric ganglion (sympathetic prevertebral ganglion) projecting to the distal colon in cat. Two weeks after injecting the microspheres into the wall of the distal colon, the inferior mesenteric ganglion was dissected out and incubated for 24 hours in a colchicine-containing culture medium in order to facilitate the detection of enkephalins in the soma of ganglion neurons. It was observed that retrogradely labelled ganglion cells contained enkephalin-like immunoreactive material. These ganglion cells corresponded to enkephalin-like postganglionic neurons, the terminals of which were located inside the wall of the distal colon. These enkephalin-like neurons were numerous and scattered throughout the ganglion. Sometimes enkephalin-like immunoreactive fibers, probably originating from spinal preganglionic neurons, ran close to immunoreactive and non-immunoreactive retrogradely labelled ganglion cells. This suggests that enkephalin-like immunoreactive fibers may make synaptic connections with enkephalin-like and non-enkephalin-like postganglionic neurons projecting to the distal colon. The present study establishes for the first time the existence of an enkephalin-like postganglionic pathway to the digestive tract originating from a sympathetic prevertebral ganglion. This finding indicates that the enkephalinergic innervation of the cat digestive tract may have at least two possible sources: (i) the sympathetic prevertebral ganglia; and (ii) the enteric nervous ganglia.

Nutritional State-Dependent Ghrelin Activation of Vasopressin Neurons via Retrograde Trans-Neuronal–Glial Stimulation of Excitatory GABA Circuits

PubMed Central

Haam, Juhee; Halmos, Katalin C.; Di, Shi

2014-01-01

Behavioral and physiological coupling between energy balance and fluid homeostasis is critical for survival. The orexigenic hormone ghrelin has been shown to stimulate the secretion of the osmoregulatory hormone vasopressin (VP), linking nutritional status to the control of blood osmolality, although the mechanism of this systemic crosstalk is unknown. Here, we show using electrophysiological recordings and calcium imaging in rat brain slices that ghrelin stimulates VP neurons in the hypothalamic paraventricular nucleus (PVN) in a nutritional state-dependent manner by activating an excitatory GABAergic synaptic input via a retrograde neuronal–glial circuit. In slices from fasted rats, ghrelin activation of a postsynaptic ghrelin receptor, the growth hormone secretagogue receptor type 1a (GHS-R1a), in VP neurons caused the dendritic release of VP, which stimulated astrocytes to release the gliotransmitter adenosine triphosphate (ATP). ATP activation of P2X receptors excited presynaptic GABA neurons to increase GABA release, which was excitatory to the VP neurons. This trans-neuronal–glial retrograde circuit activated by ghrelin provides an alternative means of stimulation of VP release and represents a novel mechanism of neuronal control by local neuronal–glial circuits. It also provides a potential cellular mechanism for the physiological integration of energy and fluid homeostasis. PMID:24790191

Safety and Efficacy of AAV Retrograde Pancreatic Ductal Gene Delivery in Normal and Pancreatic Cancer Mice.

PubMed

Quirin, Kayla A; Kwon, Jason J; Alioufi, Arafat; Factora, Tricia; Temm, Constance J; Jacobsen, Max; Sandusky, George E; Shontz, Kim; Chicoine, Louis G; Clark, K Reed; Mendell, Joshua T; Korc, Murray; Kota, Janaiah

2018-03-16

Recombinant adeno-associated virus (rAAV)-mediated gene delivery shows promise to transduce the pancreas, but safety/efficacy in a neoplastic context is not well established. To identify an ideal AAV serotype, route, and vector dose and assess safety, we have investigated the use of three AAV serotypes (6, 8, and 9) expressing GFP in a self-complementary (sc) AAV vector under an EF1α promoter (scAAV.GFP) following systemic or retrograde pancreatic intraductal delivery. Systemic delivery of scAAV9.GFP transduced the pancreas with high efficiency, but gene expression did not exceed >45% with the highest dose, 5 × 10 12 viral genomes (vg). Intraductal delivery of 1 × 10 11 vg scAAV6.GFP transduced acini, ductal cells, and islet cells with >50%, ∼48%, and >80% efficiency, respectively, and >80% pancreatic transduction was achieved with 5 × 10 11 vg. In a Kras G12D -driven pancreatic cancer mouse model, intraductal delivery of scAAV6.GFP targeted acini, epithelial, and stromal cells and exhibited persistent gene expression 5 months post-delivery. In normal mice, intraductal delivery induced a transient increase in serum amylase/lipase that resolved within a day of infusion with no sustained pancreatic inflammation or fibrosis. Similarly, in PDAC mice, intraductal delivery did not increase pancreatic intraepithelial neoplasia progression/fibrosis. Our study demonstrates that scAAV6 targets the pancreas/neoplasm efficiently and safely via retrograde pancreatic intraductal delivery.

Comparison of rectal indomethacin, diclofenac, and naproxen for the prevention of post endoscopic retrograde cholangiopancreatography pancreatitis.

PubMed

Mohammad Alizadeh, Amir H; Abbasinazari, Mohammad; Hatami, Behzad; Abdi, Saeed; Ahmadpour, Forozan; Dabir, Shideh; Nematollahi, Aida; Fatehi, Samira; Pourhoseingholi, Mohammad A

2017-03-01

NSAIDs are commonly utilized for the prevention of post endoscopic retrograde cholangiopancreatography pancreatitis (PEP). However, not much is known about the most effective drug in preventing this complication. This study aims to clarify which drug (indomethacin, diclofenac, or naproxen) is most effective for the prevention of post endoscopic retrograde cholangiopancreatography (ERCP). In a double-blind, randomized study, patients received a single rectal dose of one of the three drugs 30 min before undergoing ERCP: diclofenac (100 mg), indomethacin (100 mg), or naproxen (500 mg). The primary outcome measured was the development of pancreatitis. The levels of serum amylase, lipase, lipoxin A4, and resolvin E1 were measured before ERCP, and at 24 h after the procedure. Three hundred and seventy-two patients completed the study. The overall incidence of PEP was 8.6%, which occurred in five of the 124 (4%) patients who received diclofenac, seven of the 122 (5.8%) patients who received indomethacin, and 20 of the 126 (15.9%) patients who received naproxen. There were no significant differences in amylase and lipase levels among the three groups (P=0.183 and 0.597, respectively). Unlike patients in the naproxen group, patients in the diclofenac and indomethacin groups showed a significant increase in lipoxin A4 and resolvin E1 (P=0.001 and 0.02, respectively). Diclofenac and indomethacin patient groups had a lower incidence of PEP than the naproxen group.

Endovascular Treatment of Totally Occluded Superior Mesenteric Artery by Retrograde Crossing via the Villemin Arcade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferro, Carlo; Rossi, Umberto G., E-mail: urossi76@hotmail.com; Seitun, Sara

2013-06-15

Chronic mesenteric ischemia (CMI) is a rare disorder that is commonly caused by progressive atherosclerotic stenosis or occlusion of one or more mesenteric arteries. Endovascular treatment for symptomatic CMI represents a viable option, especially in high-operative risk patients. We report a case of acute symptomatic CMI with chronic totally occlusion of the superior mesenteric artery (SMA) associated with significant stenosis of celiac trunk (CT) and inferior mesenteric artery (IMA) that underwent endovascular treatment of all the three mesenteric arteries: stenting of CT and IMA stenosis, and recanalization of the SMA occlusion by retrograde crossing via the Villemin arcade.

The retrograde delivery of adenovirus vector carrying the gene for brain-derived neurotrophic factor protects neurons and oligodendrocytes from apoptosis in the chronically compressed spinal cord of twy/twy mice.

PubMed

Uchida, Kenzo; Nakajima, Hideaki; Hirai, Takayuki; Yayama, Takafumi; Chen, Kebing; Guerrero, Alexander Rodriguez; Johnson, William Eustace; Baba, Hisatoshi

2012-12-15

The twy/twy mouse undergoes spontaneous chronic mechanical compression of the spinal cord; this in vivo model system was used to examine the effects of retrograde adenovirus (adenoviral vector [AdV])-mediated brain-derived neurotrophic factor (BDNF) gene delivery to spinal neural cells. To investigate the targeting and potential neuroprotective effect of retrograde AdV-mediated BDNF gene transfection in the chronically compressed spinal cord in terms of prevention of apoptosis of neurons and oligodendrocytes. Several studies have investigated the neuroprotective effects of neurotrophins, including BDNF, in spinal cord injury. However, no report has described the effects of retrograde neurotrophic factor gene delivery in compressed spinal cords, including gene targeting and the potential to prevent neural cell apoptosis. AdV-BDNF or AdV-LacZ (as a control gene) was injected into the bilateral sternomastoid muscles of 18-week old twy/twy mice for retrograde gene delivery via the spinal accessory motor neurons. Heterozygous Institute of Cancer Research mice (+/twy), which do not undergo spontaneous spinal compression, were used as a control for the effects of such compression on gene delivery. The localization and cell specificity of β-galactosidase expression (produced by LacZ gene transfection) and BDNF expression in the spinal cord were examined by coimmunofluorescence staining for neural cell markers (NeuN, neurons; reactive immunology protein, oligodendrocytes; glial fibrillary acidic protein, astrocytes; OX-42, microglia) 4 weeks after gene injection. The possible neuroprotection afforded by retrograde AdV-BDNF gene delivery versus AdV-LacZ-transfected control mice was assessed by scoring the prevalence of apoptotic cells (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling-positive cells) and immunoreactivity to active caspases -3, -8, and -9, p75, neurofilament 200 kD (NF), and for the oligodendroglial progenitor marker, NG2. RESULTS

The evolution of a binary in a retrograde circular orbit embedded in an accretion disk

NASA Astrophysics Data System (ADS)

Ivanov, P. B.; Papaloizou, J. C. B.; Paardekooper, S.-J.; Polnarev, A. G.

2015-04-01

Aims: Supermassive black hole binaries may form as a consequence of galaxy mergers. Both prograde and retrograde orbits have been proposed. We study a binary with a small mass ratio, q, in a retrograde orbit immersed in and interacting with a gaseous accretion disk in order to estimate the time scales for inward migration that leads to coalescence and the accretion rate to the secondary component. Methods: We employed both semi-analytic methods and two-dimensional numerical simulations, focusing on the case where the binary mass ratio is small but large enough to significantly perturb the disk. Results: We develop the theory of type I migration in this case and go on to determine the conditions for gap formation. We find that when this happens inward migration occurs on a time scale equal to the time required for one half of the secondary mass to be accreted through the unperturbed accretion disk. The accretion rate onto the secondary itself is found to only play a minor role in the orbital evolution as it is of the order of q1/3 of that to the primary. We obtain good general agreement between the semi-analytic and fully numerical approaches and note that the former can be applied to disks with a wide dynamic range on long time scales. Conclusions: We conclude that inward migration induced by interaction with the disk can enable the binary to migrate inwards, alleviating the so-called final parsec problem. When q is sufficiently small, there is no well-pronounced cavity inside the binary orbit, unlike the prograde case. The accretion rate to the secondary does not influence the binary orbital evolution much, but can lead to some interesting observational consequences, provided the accretion efficiency is sufficiently large. In this case the binary may be detected as, for example, two sources of radiation rotating around each other. However, the study should be extended to consider orbits with significant eccentricity and the effects of gravitational radiation at

Percutaneous Retrograde Recanalization of the Celiac Artery by Way of the Superior Mesenteric Artery for Chronic Mesenteric Ischemia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joseph, George, E-mail: joseph59@gmail.com; Chacko, Sujith Thomas

2013-02-15

A 52-year-old man presented with recurrent postprandial abdominal pain, sitophobia, and progressive weight loss. Chronic mesenteric ischemia (CMI) due to subtotal occlusion of the superior mesenteric artery (SMA) and flush occlusion of the celiac artery (CA) was diagnosed. Retrograde recanalization of the CA by way of a collateral channel from the SMA was performed using contemporary recanalization equipment. The CA and SMA were then stented, resulting in sustained resolution of CMI-related symptoms.

Retrograde nail for tibiotalocalcaneal arthrodesis as a limb salvage procedure for open distal tibia and talus fractures with severe bone loss.

PubMed

Ochman, Sabine; Evers, Julia; Raschke, Michael J; Vordemvenne, Thomas

2012-01-01

The treatment of complex fractures of the distal tibia, ankle, and talus with soft tissue damage, bone loss, and nonreconstructable joints for which the optimal timing for reduction and fixation has been missed is challenging. In such cases primary arthrodesis might be a treatment option. We report a series of multi-injured patients with severe soft tissue damage and bone loss, who were treated with a retrograde tibiotalocalcaneal arthrodesis nail as a minimally invasive treatment option for limb salvage. After a median follow-up of 5.4 years, all patients returned to their former profession. The ankle and bone fusion was complete, with moderate functional results and quality of life. Calcaneotibial arthrodesis using a retrograde nail is a good treatment option for nonreconstructable fractures of the ankle joint with severe bone loss and poor soft tissue quality in selected patients with multiple injuries, in particular, those involving both lower extremities, as a salvage procedure. Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Dissociative amnesia: Disproportionate retrograde amnesia, stressful experiences and neurological circumstances.

PubMed

Thomas-Antérion, C

Dissociative amnesias have been reported in neurological episodes mild enough to not cause any visible lesions on morphological examination. Disproportionate retrograde amnesia with or without identity loss happens in the context of psychological trauma (known or not). In metabolic imaging studies, some authors have reported functional alterations, particularly in the bilateral hippocampus, right temporal regions and inferolateral prefrontal cortex, despite normal morphological imaging. To avoid the presumption of an organic, psychogenic or mixed origin for such changes, De Renzi et al. suggested the term 'functional amnesia' to describe the condition. Patients have sometimes recovered during events similar to those preceding the amnesia in either a spectacular fashion or never. Also, in some cases, distraction or sedation may trigger the start of recovery. During psychotherapy, one patient remembered seeing a car on fire when he was a boy, and his amnesia started when his house was on fire. This suggests control by the frontal cortex, with repression blocking amnesic traces in the new emotional and biological context. Copyright © 2017. Published by Elsevier Masson SAS.

The patient position for PNL: does it matter?

PubMed

Cracco, Cecilia Maria; Scoffone, Cesare Marco; Poggio, Massimiliano; Scarpa, Roberto Mario

2010-03-01

Currently, PNL is the treatment of choice for large and/or otherwise complex urolithiasis. PNL was initially performed with the patient in a supine-oblique position, but later on the prone position became the conventional one for habit and handiness. The prone position provides a larger area for percutaneous renal access, a wider space for instrument manipulation, and a claimed lower risk of splanchnic injury. Nonetheless, it implies important anaesthesiological risks, including circulatory, haemodynamic, and ventilatory difficulties; need of several nurses to be present for intraoperative changes of the decubitus in case of simultaneous retrograde instrumentation of the ureter, implying evident risks related to pressure points; an increased radiological hazard to the urologist's hands; patient discomfort. To overcome these drawbacks, various safe and effective changes in patient positioning for PNL have been proposed over the years, including the reverse lithotomy position, the prone split-leg position, the lateral decubitus, the supine position, and the Galdakao-modified supine Valdivia (GMSV) position. Among these, the GMSV position is safe and effective, and seems profitable and ergonomic. It allows optimal cardiopulmonary control during general anaesthesia; an easy puncture of the kidney; a reduced risk of colonic injury; simultaneous antero-retrograde approach to the renal cavities (PNL and retrograde ureteroscopy = ECIRS, Endoscopic Combined IntraRenal Surgery), with no need of intraoperative repositioning of the anaesthetized patient, less need for nurses in the operating room, less occupational risk due to shifting of heavy loads, less risk of pressure injuries related to inaccurate repositioning, and reduced duration of the procedure; facilitated spontaneous evacuation of stone fragments; a comfortable sitting position and a restrained X-ray exposure of the hands for the urologist. But, first of all, GMSV position fully supports a new comprehensive

Endoscopic ultrasound and endoscopic retrograde cholangiopancreatography: Can they be successfully combined?

PubMed

Gornals, Joan B; Esteban, José Miguel; Guarner-Argente, Carlos; Marra-Lopez, Carlos; Repiso, Alejandro; Sendino, Oriol; Loras, Carme

2016-11-01

Endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) have much in common, including their main indications (biliopancreatic disorders), powerful therapeutic capacities and a steep learning curve. Over the years they have evolved from novel diagnostic procedures to interventional therapeutic techniques, but along different paths (different scopes or devices and endoscopists specializing exclusively in one or the other technique). However, EUS has gradually developed into a therapeutic technique that requires skills in the use of ERCP devices and stents, leading some ERCP specialists to explore the therapeutic potential of EUS. The corresponding literature, which has grown exponentially, includes recent experiments on combining the two techniques, which have gradually come to be used in routine care in a number of centers, with positive technical, clinical and financial outcomes. We review EUS and ERCP as individual or combined procedures for managing biliopancreatic disorders. Copyright © 2016 Elsevier España, S.L.U. y AEEH y AEG. All rights reserved.

[Psychological aspects of treating staghorn nephrolithiasis using percutaneous and retrograde nephrolithotripsy].

PubMed

Podoinitsyn, A A; Dutov, V V

2016-11-01

To investigate the level of anxiety and the severity of asthenic state in patients with staghorn nephrolithiasis treated by of minimally invasive therapies - percutaneous nephrolithotripsy (PNLT) and retrograde nephrolithotripsy (RNLT). This study analyzed the psychological state of 150 patients with staghorn nephrolithiasis aged 25 to 75 years before and after PNLT and RNLT. Testing was performed at baseline, at 5-7 day of hospital stay (average time of preparing for surgery) and after treatment with the use of various questionnaires: Anxiety Scale, Asthenic conditions scale and Pain questionnaire. The follow-up findings shower positive changes, including reduction in the level of anxiety and severity of asthenia in patients of different age groups. The decrease in anxiety level and severity of fatigue was associated with decreased rates of neuropathic component of pain. The psychological state of patients with staghorn nephrolithiasis depends on the characteristics of minimally invasive methods of treatment and requires attending physicians and medical personnel to take into consideration the mental and emotional state of patients.

Periorbital Ecchymosis (Raccoon Eye) and Orbital Hematoma following Endoscopic Retrograde Cholangiopancreatography.

PubMed

Nasiri, Jafar; Zamani, Farhad

2017-01-01

Endoscopic retrograde cholangiopancreatography (ERCP) is a conventional technique for diagnosis and treatment of pancratobiliary diseases, which is associated with various complications, including pancreatitis, hemorrhage, cholangitis, perforation, and mortality. In our case, a 69-year-old woman with positive hepatobiliary symptoms underwent ERCP, at the end of which a rare complication (raccoon eye) occurred, which was hypothesized to be due to amyloidosis, but the patient refused to complete the diagnostic procedure and became symptom free after 3 weeks. Racoon eye or periorbital ecchymosis is caused by blood tracking into periorbital tissues, which is frequently observed after head trauma but is also observed in systemic diseases, such as amyloidosis, neuroblastoma, and surgical interventions. To the best of our knowledge, this is the first report of raccoon eye after ERCP; further reports will help to confirm that this complication should also be considered before performing ERCP and that complete diagnostic tests for the predisposing diseases prior to ERCP are necessary.

Periorbital Ecchymosis (Raccoon Eye) and Orbital Hematoma following Endoscopic Retrograde Cholangiopancreatography

PubMed Central

Nasiri, Jafar; Zamani, Farhad

2017-01-01

Endoscopic retrograde cholangiopancreatography (ERCP) is a conventional technique for diagnosis and treatment of pancratobiliary diseases, which is associated with various complications, including pancreatitis, hemorrhage, cholangitis, perforation, and mortality. In our case, a 69-year-old woman with positive hepatobiliary symptoms underwent ERCP, at the end of which a rare complication (raccoon eye) occurred, which was hypothesized to be due to amyloidosis, but the patient refused to complete the diagnostic procedure and became symptom free after 3 weeks. Racoon eye or periorbital ecchymosis is caused by blood tracking into periorbital tissues, which is frequently observed after head trauma but is also observed in systemic diseases, such as amyloidosis, neuroblastoma, and surgical interventions. To the best of our knowledge, this is the first report of raccoon eye after ERCP; further reports will help to confirm that this complication should also be considered before performing ERCP and that complete diagnostic tests for the predisposing diseases prior to ERCP are necessary. PMID:28611566

Villous adenoma of the common hepatic duct: the importance of contrast-enhanced ultrasound and endoscopic retrograde cholangiopancreatography for relevant diagnosis. A case report and review of the literature.

PubMed

Tefas, Cristian; Tanţău, Marcel; Szenftleben, Alexandru; Chiorean, Liliana; Badea, Radu

2015-12-01

Adenomas are frequently encountered in the lower digestive tract but are rarely diagnosed in the biliary tree. We report a case of villous adenoma of the common hepatic duct. A 58-year old male was admitted with a four week history of intermittent upper right quadrant pain. Gray scale and contrast-enhanced abdominal ultrasound showed a mass inside the common hepatic duct with arterial enhancement and slow wash-out during the late venous phase. Subsequent endoscopic retrograde cholangiopancreatography and intraductal ultrasound confirmed the presence of the lesion. The final histopathological examination showed villous adenoma of the common hepatic duct with high-grade dysplasia. Contrast enhanced ultrasonography used in conjecture with endoscopic retrograde cholangiopancreatography can help in differentiating biliary tumors.

Attenuation of reflected waves in man during retrograde propagation from femoral artery to proximal aorta.

PubMed

Baksi, A John; Davies, Justin E; Hadjiloizou, Nearchos; Baruah, Resham; Unsworth, Beth; Foale, Rodney A; Korolkova, Olga; Siggers, Jennifer H; Francis, Darrel P; Mayet, Jamil; Parker, Kim H; Hughes, Alun D

2016-01-01

Wave reflection may be an important influence on blood pressure, but the extent to which reflections undergo attenuation during retrograde propagation has not been studied. We quantified retrograde transmission of a reflected wave created by occlusion of the left femoral artery in man. 20 subjects (age 31-83 years; 14 male) underwent invasive measurement of pressure and flow velocity with a sensor-tipped intra-arterial wire at multiple locations distal to the proximal aorta before, during and following occlusion of the left femoral artery by thigh cuff inflation. A numerical model of the circulation was also used to predict reflected wave transmission. Wave reflection was measured as the ratio of backward to forward wave energy (WRI) and the ratio of peak backward to forward pressure (Pb/Pf). Cuff inflation caused a marked reflection which was largest at 5-10 cm from the cuff (change (Δ) in WRI=0.50 (95% CI 0.38, 0.62); p<0.001, ΔPb/Pf=0.23 (0.18-0.29); p<0.001). The magnitude of the cuff-induced reflection decreased progressively at more proximal locations and was barely discernible at sites>40 cm from the cuff including in the proximal aorta. Numerical modelling gave similar predictions to those observed experimentally. Reflections due to femoral artery occlusion are markedly attenuated by the time they reach the proximal aorta. This is due to impedance mismatches of bifurcations traversed in the backward direction. This degree of attenuation is inconsistent with the idea of a large discrete reflected wave arising from the lower limb and propagating back into the aorta. Copyright © 2015. Published by Elsevier Ireland Ltd.

Simple retrograde cerebral perfusion is as good as complex antegrade cerebral perfusion for hemiarch replacement.

PubMed

Tanaka, Akiko; Estrera, Anthony L

2018-01-01

Cerebral complication is a major concern after aortic arch surgery, which may lead to death. Thus, cerebral protection strategy plays the key role to obtain respectable results in aortic arch repair. Deep hypothermic circulatory arrest was introduced in 1970s to decrease the ischemic insults to the brain. However, safe duration of circulatory arrest time was limited to 30 minutes. The 1990s was the decade of evolution for cerebral protection, in which two adjuncts for deep hypothermic circulatory arrest were introduced: retrograde and antegrade cerebral perfusion (ACP) techniques. These two cerebral perfusion techniques significantly decreased incidence of postoperative neurological dysfunction and mortality after aortic arch surgery. Although there are no large prospective studies that demonstrate which perfusion technique provide better outcomes, multiple retrospective studies implicate that ACP may decrease cerebral complications compared to retrograde cerebral perfusion (RCP) when a long circulatory arrest time is required during aortic arch reconstructions. To date, many surgeons favor ACP over RCP during a complex aortic arch repair, such as total arch replacement and hybrid arch replacement. However, the question is whether the use of ACP is necessary during a short, limited circulatory arrest time, such as hemiarch replacement? There is a paucity of data that proves the advantages of a complex ACP over a simple RCP for a short circulatory arrest time. RCP with deep hypothermic circulatory arrest is the simple, efficient cerebral protection technique with minimal interference to the surgical field-and it potentially allows to flush atheromatous debris out from the arch vessels. Thus, it is the preferred adjunct to deep hypothermic circulatory arrest during hemiarch replacement in our institution.

Simple retrograde cerebral perfusion is as good as complex antegrade cerebral perfusion for hemiarch replacement

PubMed Central

Tanaka, Akiko

2018-01-01

Cerebral complication is a major concern after aortic arch surgery, which may lead to death. Thus, cerebral protection strategy plays the key role to obtain respectable results in aortic arch repair. Deep hypothermic circulatory arrest was introduced in 1970s to decrease the ischemic insults to the brain. However, safe duration of circulatory arrest time was limited to 30 minutes. The 1990s was the decade of evolution for cerebral protection, in which two adjuncts for deep hypothermic circulatory arrest were introduced: retrograde and antegrade cerebral perfusion (ACP) techniques. These two cerebral perfusion techniques significantly decreased incidence of postoperative neurological dysfunction and mortality after aortic arch surgery. Although there are no large prospective studies that demonstrate which perfusion technique provide better outcomes, multiple retrospective studies implicate that ACP may decrease cerebral complications compared to retrograde cerebral perfusion (RCP) when a long circulatory arrest time is required during aortic arch reconstructions. To date, many surgeons favor ACP over RCP during a complex aortic arch repair, such as total arch replacement and hybrid arch replacement. However, the question is whether the use of ACP is necessary during a short, limited circulatory arrest time, such as hemiarch replacement? There is a paucity of data that proves the advantages of a complex ACP over a simple RCP for a short circulatory arrest time. RCP with deep hypothermic circulatory arrest is the simple, efficient cerebral protection technique with minimal interference to the surgical field—and it potentially allows to flush atheromatous debris out from the arch vessels. Thus, it is the preferred adjunct to deep hypothermic circulatory arrest during hemiarch replacement in our institution. PMID:29682460

Tibiotalocalcaneal arthrodesis with a retrograde intramedullary nail: a biomechanical analysis of the effect of nail length.

PubMed

Noonan, Timothy; Pinzur, Michael; Paxinos, Odysseas; Havey, Robert; Patwardhin, Avinash

2005-04-01

Fatigue fractures of the tibia have been observed at the level of the proximal end of the nail after successful tibiocalcaneal arthrodesis with a retrograde intramedullary device. To study the effect of nail length, five matched pairs of cadaver tibiae were instrumented with strain gauges and potted in methylmethacrylate from a level 3 cm proximal to the distal medial malleolus to simulate a successful tibiocalcaneal arthrodesis. A standard length (15 cm) ankle arthrodesis nail and an identical longer device terminating in the proximal tibial metaphysis were inserted in each paired tibia using appropriate technique. The strain of the posterior cortex of the tibia was recorded under bending moments of up to 50 Nm for each intact specimen after nail insertion and after proximal locking of the nail. The nails were then exchanged between the specimens of the same pairs and the experiment was repeated to insure uniformity. The standard length locked nail increased the principal strain of the posterior cortex of the tibia at the level of the proximal screw holes 5.3 times more than the locked long nail (353 and 67 microstrains), respectively. This stress concentration was not observed when the proximal extent of the nail terminated within the proximal tibial metaphysis. A successful tibiocalcaneal arthrodesis with a standard length locked intramedullary nail creates stress concentration around the proximal screw holes that may be responsible for the fractures observed clinically. This study supports the use of a "long" retrograde locked intramedullary nail for tibiocalcaneal arthrodesis in patients with systemic or localized osteopenia.

SWIFT J1910.2-0546: A Possible Black Hole Binary with a Retrograde Spin or Truncated Disk

NASA Astrophysics Data System (ADS)

Reis, R. C.; Reynolds, M. T.; Miller, J. M.; Walton, D. J.; Maitra, D.; King, A.; Degenaar, N.

2013-12-01

We present the first results from a long (51 ks) XMM-Newton observation of the Galactic X-ray binary SWIFT J1910.2-0546 in an intermediate state, obtained during its 2012 outburst. A clear, asymmetric iron emission line is observed and physically motivated models are used to fully describe the emission-line profile. Unlike other sources in their intermediate spectral states, the inner accretion disk in SWIFT J1910.2-0546 appears to be truncated, with an inner radius of r in =9.4^{+1.7}_{-1.3} r g at a 90% confidence limit. Quasi-periodic oscillations are also found at approximately 4.5 and 6 Hz, which correlates well with the break frequency of the underlying broad-band noise. Assuming that the line emission traces the innermost stable circular orbit, as would generally be expected for an intermediate state, the current observation of SWIFT J1910.2-0546 may offer the best evidence for a possible retrograde stellar mass black hole with a spin parameter a < - 0.32cJ/GM2 (90% confidence). Although this is an intriguing possibility, there are also a number of alternative scenarios which do not require a retrograde spin. For example, the inner accretion disk may be truncated at an unusually high luminosity in this case, potentially suffering frequent evaporation/condensation, or it could instead be persistently evacuated through mass loss in a relativistic jet. Further observations are required to distinguish between these different interpretations.

Mitigation of nociception via transganglionic degenerative atrophy: possible mechanism of vinpocetine-induced blockade of retrograde axoplasmic transport.

PubMed

Csillik, Bertalan; Mihály, András; Krisztin-Péva, Beata; Farkas, Ibolya; Knyihár-Csillik, Elizabeth

2008-01-01

Vinpocetine, a derivative of vincamine, widely used in the clinical pharmacotherapy of cerebral circulatory diseases, inhibits retrograde axoplasmic transport of nerve growth factor (NGF) in the peripheral nerve, resulting in transganglionic degenerative atrophy (TDA) in the related ipsilateral superficial spinal dorsal horn, as shown in our previous publications. TDA induced by vinpocetine has been demonstrated to be followed by depletion of the marker enzyme fluoride-resistant acid phosphatase (FRAP) and its isoenzyme thiamine monophosphatase (TMP), and by the decrease in the pain-related neuropeptide substance P from laminae I-II-(III) from the segmentally related, ipsilateral substance of Rolando of the spinal cord. In the present paper, we report on the behavioral effects of perineurally administered vinpocetine. Nociception, induced by intraplantar injection of formalin, was mitigated by vinpocetine; increased expression of c-fos in the ipsilateral, segmentally related upper dorsal horn was also prevented. Since vinpocetine is not a microtubule inhibitor, and its chemical structure differs from that of vincristin and vinblastin (used formerly by us in the therapy of intractable, chronic neuropathic pain), its mode of action is enigmatic. We assume that the effect of vinpocetine in blocking retrograde axoplasmic transport of NGF might be related to its interaction with membrane trafficking proteins, such as signalling endosomes and the endocytosis-mediating "pincher" protein. Temporary, locally restricted decrease of nociception, induced by vinpocetine, might be useful in the clinical treatment of intractable, chronic neuropathic pain, since vinpocetine can successfully be applied by transcutaneous iontophoresis.

Bleeding Duodenal Varices Successfully Treated with Balloon-Occluded Retrograde Transvenous Obliteration (B-RTO) Assisted by CT During Arterial Portography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsurusaki, Masakatsu, E-mail: he3m-trsk@asahi-net.or.jp; Sugimoto, Koji; Matsumoto, Shinichi

2006-12-15

A 60-year-old woman with massive hemorrhage from duodenal varices was transferred to our hospital for the purpose of transcatheter intervention. Although digital subtraction arterial portography could not depict the entire pathway of collateral circulation, the efferent route of the duodenal varices was clearly demonstrated on subsequent CT during arterial portography. Balloon-occluded retrograde transvenous obliteration (B-RTO) of the varices was performed via the efferent vein and achieved complete thrombosis of the varices.

Dual Anterograde and Retrograde Viral Tracing of Reciprocal Connectivity.

PubMed

Haberl, Matthias G; Ginger, Melanie; Frick, Andreas

2017-01-01

Current large-scale approaches in neuroscience aim to unravel the complete connectivity map of specific neuronal circuits, or even the entire brain. This emerging research discipline has been termed connectomics. Recombinant glycoprotein-deleted rabies virus (RABV ∆G) has become an important tool for the investigation of neuronal connectivity in the brains of a variety of species. Neuronal infection with even a single RABV ∆G particle results in high-level transgene expression, revealing the fine-detailed morphology of all neuronal features-including dendritic spines, axonal processes, and boutons-on a brain-wide scale. This labeling is eminently suitable for subsequent post-hoc morphological analysis, such as semiautomated reconstruction in 3D. Here we describe the use of a recently developed anterograde RABV ∆G variant together with a retrograde RABV ∆G for the investigation of projections both to, and from, a particular brain region. In addition to the automated reconstruction of a dendritic tree, we also give as an example the volume measurements of axonal boutons following RABV ∆G-mediated fluorescent marker expression. In conclusion RABV ∆G variants expressing a combination of markers and/or tools for stimulating/monitoring neuronal activity, used together with genetic or behavioral animal models, promise important insights in the structure-function relationship of neural circuits.

Selective binding, uptake, and retrograde transport of tetanus toxin by nerve terminals in the rat iris. An electron microscope study using colloidal gold as a tracer

PubMed Central

1978-01-01

A series of specific macromolecules (tetanus toxin, cholera toxin, nerve growth factor [NGF], and several lectins) have been shown to be transported retrogradely with high selectivity from terminals to cell bodies in various types of neurons. Under identical experimental conditions (low protein concentrations injected), most other macromolecules, e.g. horseradish peroxidase (HRP), albumin, ferritin, are not transported in detectable amounts. In the present EM study, we demonstrate selective binding of tetanus toxin to the surface membrane of nerve terminals, followed by uptake and subsequent retorgrade axonal transport. Tetanus toxin or albumin was adsorbed to colloidal gold particles (diam 200 A). The complex was shown to be stable and well suited as an EM tracer. 1-4 h after injection into the anterior eye chamber of adult rats, tetanus toxin-gold particles were found to be selectively associated with membranes of nerve terminals and preterminal axons. Inside terminals and axons, the tracer was localized mainly in smooth endoplasmic reticulum (SER)-like membrane compartments. In contrast, association of albumin-gold complexes with nervous structures was never observed, in spite of extensive uptake into fibroblasts. Electron microscope and biochemical experiments showed selective retrograde transport of tetanus toxin-gold complexes to the superior cervical ganglion. Specific binding to membrane components at nerve terminals and subsequent internalization and retrograde transport may represent an important pathway for macromolecules carrying information from target organs to the perikarya of their innervating neurons. PMID:659508

Retrograde exchange of heavily encrusted ureteric stents via the ileal conduit: a technical report.

PubMed

Tapping, Charles Ross; Boardman, Phil

2014-02-01

We describe two cases of retrograde ureteric stent exchange of heavily encrusted ureteric stents (JJ) via tortuous ileal conduits. The blocked ureteric stents were snared from inside the conduit so they could be accessed and a wire inserted. The lumens of the stents were unblocked with a wire but the stents could not be withdrawn due to heavy encrustation of the ureteric stent in the renal pelvis. A stiff wire was inserted to provide support and a 9 French peel away sheath was used to remove the encrustations allowing the stents to be withdrawn and exchanged. This is a safe and successful technique allowing ureteric stents to be removed when heavily encrusted. © 2013 The Royal Australian and New Zealand College of Radiologists.

[Reconstruction of severe contracture of the first web space and wrist by incorporating pedicled retrograde flap of forearm transplantation].

PubMed

Chen, Jianchong; Wu, Zuhuang; Zhu, Jianxian; Huang, Yongxin; Xie, Baogen

2011-10-01

To summarize the therapeutic effectiveness of incorporating pedicled retrograde flap of forearm transplantation for reconstructing severe contracture of the first web space and wrist. Between November 2005 and February 2010, 26 patients with severe contracture of the first web and wrist were treated. There were 18 males and 8 females with an average age of 27 years (range, 12-45 years). The locations were the right sides in 15 cases and the left sides in 11 cases. The injury reason included hot water scald in 7 cases, explosion hurt in 5 cases, traffic accident in 3 cases, hot pressing in 5 cases, and flame burns in 6 cases. The duration of scar contracture ranged from 6 to 26 months with an average of 11 months. According to the evaluation standard by GU Yudong et al., all had severe contracture of the first web space, and concomitant injuries included adduction deformity thumb, limitation of the thumb extension and opposition function, and carpometacarpal flexion joint deformity. After scar contracture was released, the defect size ranged from 5.8 cm x 4.5 cm to 11.3 cm x 7.2 cm, which were repaired by the incorporating pedicled retrograde flap of forearm of 6.5 cm x 5.0 cm to 12.5 cm x 8.0 cm at size. The donor sites were directly sutured or repaired with skin graft. Blister and partial necrosis occurred at the distal end of the flaps in 2 cases, which were cured after dressing change. The other flaps survived and wounds healed by first intention. Incisions at donor sites healed by first intention. Twenty-six patients were followed up 6 to 24 months (mean, 15 months). The patients had functional recovery in thumb adduction and opposition at different degrees. At 6 months after operation, according to the Swanson et al. AMA system for total thumb activity, the total thumb function was improved significantly, and according to Jensen et al. measurement, the width and angle of the first web space were significantly increased, all showing significant differences (P

Development of prognostic model for predicting survival after retrograde placement of ureteral stent in advanced gastrointestinal cancer patients and its evaluation by decision curve analysis.

PubMed

Kawano, Shingo; Komai, Yoshinobu; Ishioka, Junichiro; Sakai, Yasuyuki; Fuse, Nozomu; Ito, Masaaki; Kihara, Kazunori; Saito, Norio

2016-10-01

The aim of this study was to determine risk factors for survival after retrograde placement of ureteral stents and develop a prognostic model for advanced gastrointestinal tract (GIT: esophagus, stomach, colon and rectum) cancer patients. We examined the clinical records of 122 patients who underwent retrograde placement of a ureteral stent against malignant extrinsic ureteral obstruction. A prediction model for survival after stenting was developed. We compared its clinical usefulness with our previous model based on the results from nephrostomy cases by decision curve analysis. Median follow-up period was 201 days (8-1490) and 97 deaths occurred. The 1-year survival rate in this cohort was 29%. Based on multivariate analysis, primary site of colon origin, absence of retroperitoneal lymph node metastasis and serum albumin >3g/dL were significantly associated with a prolonged survival time. To develop a prognostic model, we divided the patients into 3 risk groups of favorable: 0-1 factors (N.=53), intermediate: 2 risk factors (N.=54), and poor: 3 risk factors (N.=15). There were significant differences in the survival profiles of these 3 risk groups (P<0.0001). Decision curve analyses revealed that the current model has a superior net benefit than our previous model for most of the examined probabilities. We have developed a novel prognostic model for GIT cancer patients who were treated with retrograde placement of a ureteral stent. The current model should help urologists and medical oncologists to predict survival in cases of malignant extrinsic ureteral obstruction.

Uncoupling High Light Responses from Singlet Oxygen Retrograde Signaling and Spatial-Temporal Systemic Acquired Acclimation.

PubMed

Carmody, Melanie; Crisp, Peter A; d'Alessandro, Stefano; Ganguly, Diep; Gordon, Matthew; Havaux, Michel; Albrecht-Borth, Verónica; Pogson, Barry J

2016-07-01

Distinct ROS signaling pathways initiated by singlet oxygen ((1)O2) or superoxide and hydrogen peroxide have been attributed to either cell death or acclimation, respectively. Recent studies have revealed that more complex antagonistic and synergistic relationships exist within and between these pathways. As specific chloroplastic ROS signals are difficult to study, rapid systemic signaling experiments using localized high light (HL) stress or ROS treatments were used in this study to uncouple signals required for direct HL and ROS perception and distal systemic acquired acclimation (SAA). A qPCR approach was chosen to determine local perception and distal signal reception. Analysis of a thylakoidal ascorbate peroxidase mutant (tapx), the (1)O2-retrograde signaling double mutant (ex1/ex2), and an apoplastic signaling double mutant (rbohD/F) revealed that tAPX and EXECUTER 1 are required for both HL and systemic acclimation stress perception. Apoplastic membrane-localized RBOHs were required for systemic spread of the signal but not for local signal induction in directly stressed tissues. Endogenous ROS treatments revealed a very strong systemic response induced by a localized 1 h induction of (1)O2 using the conditional flu mutant. A qPCR time course of (1)O2 induced systemic marker genes in directly and indirectly connected leaves revealed a direct vascular connection component of both immediate and longer term SAA signaling responses. These results reveal the importance of an EXECUTER-dependent (1)O2 retrograde signal for both local and long distance RBOH-dependent acclimation signaling that is distinct from other HL signaling pathways, and that direct vascular connections have a role in spatial-temporal SAA induction. © 2016 American Society of Plant Biologists. All Rights Reserved.

Tibiotalocalcaneal Arthrodesis Using Retrograde Intramedullary Nail Fixation: Comparison of Patients With and Without Diabetes Mellitus

PubMed Central

Wukich, Dane K.; Mallory, Brady R.; Suder, Natalie C.; Rosario, Bedda L.

2017-01-01

Retrograde intramedullary nailing for tibiotalocalcaneal arthrodesis is a salvage procedure reserved for severe cases of deformity. The aim of the present study was to compare the outcomes of this technique in patients with and without diabetes mellitus (DM). A total of 61 patients with and 56 without DM underwent retrograde intramedullary nailing and had a minimum follow-up period of 12 months. The overall incidence of complication was 45.2%; however, the overall incidence of complications between those with and without DM was not significantly different (odds ratio [OR] 0.79, 95% confidence interval [CI] 0.38 to 1.65, p = .54). Patients with DM had a significantly greater rate of superficial infections (OR 8.3, 95% CI 1.01 to 68.67, p = .03). However, no difference was seen in the rate of deep infection (OR 0.90, 95% CI 0.34 to 2.46, p = .83) or noninfectious complications (OR 0.50, 95% CI 0.23 to 1.13, p = .09). Successful limb salvage was achieved for 96.8% of the patients with DM and 94.7% of those without DM (p = .66). A femoral head allograft was used in 32 (27.4%) of 117 patients to substitute for an osseous void. Of the 32 patients who required a femoral head allograft, 21 (67.7%) experienced a complication compared with 32 (37.6%) of 85 patients who did not require a femoral head allograft (OR 3.16, 95% CI 1.35 to 7.41, p = .008). The incidence of patient satisfaction was 80% for patients with DM and 72% for those without DM (p = .36). Despite a high incidence of complications, limb salvage was accomplished in approximately 95% of patients with complicated deformities. Four patients (6.56%) with DM experienced a tibia fracture; therefore, we now routinely use a 300-mm-long nail for this reconstruction. PMID:26015305

Fluoroscopy-guided retrograde core drilling and cancellous bone grafting in osteochondral defects of the talus.

PubMed

Anders, Sven; Lechler, Philipp; Rackl, Walter; Grifka, Joachim; Schaumburger, Jens

2012-08-01

In undetached osteochondral lesions (OCL) of the talus both revitalisation of the subchondral necrosis and cartilage preservation are essential. For these cases, we assess the results of minimally invasive retrograde core drilling and cancellous bone grafting. Forty-one osteochondral lesions of the talus (12x grade I, 22x grade II and 7x grade III according to the Pritsch classification, defect sizes 7-14 mm) in 38 patients (mean age 33.2 years) treated by fluoroscopy-guided retrograde core drilling and autologous cancellous bone grafting were evaluated by clinical scores and MRI. The mean follow-up was 29.0 (±13) months. The AOFAS score increased significantly from 47.3 (±15.3) to 80.8 (±18.6) points. Lesions with intact cartilage (grades I and II) had a tendency to superior results than grade III lesions (83.1 ± 17.3 vs. 69.4 ± 22.2 points, p = 0.07). First-line treatments and open distal tibial growth plates led to significantly better outcomes (each p < 0.05). Age, gender, BMI, time to follow-up, defect localisation or a traumatic origin did not influence the score results. On a visual analogue scale pain intensity reduced from 7.5 (±1.5) to 3.7 (±2.6) while subjective function increased from 4.6 (±2.0) to 8.2 (±2.3) (each p < 0.001). In MRI follow-ups, five of the 41 patients showed a complete bone remodelling. In two cases demarcation was detectable. The technique reported is a highly effective therapeutic option in OCL of the talus with intact cartilage grades I and II. However, second-line treatments and grade III lesions with cracked cartilage surface can not be generally recommended for this procedure.

Retrograde Ureteroscopic Management of Large Renal Calculi: A Single Institutional Experience and Concise Literature Review.

PubMed

Scotland, Kymora B; Rudnick, Benjamin; Healy, Kelly A; Hubosky, Scott G; Bagley, Demetrius H

2018-06-06

Advances in flexible ureteroscope design and accessory instrumentation have allowed for more challenging cases to be treated ureteroscopically. Here, we evaluate our experience with ureteroscopy (URS) for the management of large renal calculi (≥2 cm) and provide a concise review of recent reports. A retrospective review was undertaken of all URS cases between 2004 and 2014 performed by the endourologic team at a single academic tertiary care institution. We identified patients with at least one stone ≥2 cm managed with retrograde URS. Stone size was defined as the largest linear diameter of the index stone. Small diameter flexible ureteroscopes were used primarily with holmium laser. Patient demographics, intraoperative data, and postoperative outcomes were evaluated. We evaluated 167 consecutive patients who underwent URS for large renal stones ≥2 cm. The initial reason for choosing URS included patient preference (29.5%), failure of other therapies (8.2%), anatomic considerations/body habitus (30.3%), and comorbidities (28.8%). Mean patient age was 55.5 years (22-84). The mean stone size was 2.75 cm with mean number of procedures per patient of 1.65 (1-6). The single session stone-free rate was 57.1%, two-stage procedure stone-free rate was 90.2% and three-stage stone-free rate was 94.0%. Access sheaths were used in 47% of patients. An association was identified between stone size and patient outcomes; smaller stones correlated with decreased number of procedures. Postoperative complications were minor. Single or multi-stage retrograde ureteroscopic lithotripsy is a safe and effective mode of surgical management of large renal calculi. Total stone burden is a reliable predictor of the need for a staged procedure and of stone-free rate.

Direct retrograde cholangioscopy with a new prototype double-bending cholangioscope.

PubMed

Beyna, Torsten; Farnik, Harald; Sarrazin, Christoph; Gerges, Christian; Neuhaus, Horst; Albert, Jörg G

2016-10-01

Direct retrograde cholangioscopy (DRC) enables high quality video imaging of the bile ducts and allows intraductal treatment with optical control. We evaluated the feasibility, success, and complications of a new third-generation prototype cholangioscope. All consecutive patients from two tertiary endoscopy centers who had undergone DRC with the prototype were included. Indications for DRC were: evaluation of indeterminate strictures, filling defects, and complex bile duct stones. Technical success was investigated in terms of indication and treatment performed. All adverse events were recorded. DRC with the prototype was performed in 74 patients. Therapeutic interventions included laser or electrohydraulic lithotripsy and stone removal, among others. The papilla was entered in 72/74 patients (97 %). The targeted bile duct segment was reached in 62 /74 patients (84 %), with an anchoring balloon catheter needed in 21/74 (28 %). Mean investigation time was 21 minutes (15 - 27 minutes) DRC using the prototype is feasible, safe, and attains access to the bile ducts in almost all patients, with less need of an anchoring balloon catheter compared with the standard technique and short investigation and fluoroscopy times. © Georg Thieme Verlag KG Stuttgart · New York.

Balloon-occluded Retrograde Transvenous Obliteration (BRTO): Preprocedural Evaluation and Imaging

PubMed Central

Al-Osaimi, Abdullah M. S.; Sabri, Saher S.; Caldwell, Stephen H.

2011-01-01

Patients undergoing balloon retrograde transvenous obliteration (BRTO) are mostly decompensated cirrhotic with either bleeding gastric varices (GV) or hepatic encephalopathy. It is crucial that clinicians are up-to-date with the assessments needed prior to BRTO to anticipate and prevent complications, and to deliver critical quality care. These patients will require preprocedural assessments and management, including endoscopic, clinical, laboratory, and imaging evaluation. Endoscopic evaluation is mandatory prior to BRTO, and it is highly recommended that it be performed at the same institution where BRTO will be performed. It is essential that clinicians are aware of the potential benefits and complications that may result from BRTO. These complications should be anticipated and prevented when possible. For GV bleeders, there should be consideration of a transvenous intrahepatic portosystemic shunt (TIPS) during or before BRTO in patients with refractory ascites or pleural effusion, as well as endoscopic banding or a TIPS in patients with high-risk esophageal varices. Patients undergoing BRTO are usually complicated and require a team approach. In this article, the authors address these assessment and preparatory management and planning procedures prior to the BRTO procedure as well as expected outcomes and potential complications. PMID:22942546

Retrograde transcatheter device closure of a complex paravalvular leak after bioprosthetic pulmonary valve replacement in a pediatric patient.

PubMed

Chikkabyrappa, Sathish; Mosca, Ralph S; McElhinney, Doff B

2016-06-01

We report a case of retrograde transcatheter device closure of a complex paravalvular leak (PVL) after bioprosthetic pulmonary valve replacement (PVR) in a 13-year-old patient with congenital pulmonary valve stenosis. There are prior reports of pulmonary PVL closure after PVR in adults (Seery and Slack, Congenit Heart Dis 2014;9:E19-F22), but indications for and technical considerations in PVL closure after bioprosthetic PVR, particularly in children, are not well defined. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Effects of prior aversive experience upon retrograde amnesia induced by hypothermia.

PubMed

Jensen, R A; Riccio, D C; Gehres, L

1975-08-01

Two experiments examined the extent to which retrograde amnesia (RA) is attenuated by prior learning experiences. In Experiment 1, rats initially received either passive avoidance training in a step-through apparatus, exposure to the apparatus, or noncontingent footshock. When training on a second but different passive avoidance task was followed by hypothermia treatment, RA was obtained only in the latter two groups. In Experiment 2, one-way active avoidance training, yoked noncontingent shocks, or apparatus exposure constituted the initial experience. Subsequent step-down passive avoidance training and amnestic treatment resulted in memory loss for the prior apparatus exposure group, but not for either of the preshocked conditions. These experiments demonstrate that certain types of prior aversive experience can substantially modify the magnitude of RA, and, in conjunction with other familiarization studies, emphasize a paradox for interpretations of RA based solely upon CNS disruption. The possibility that hypothermia treatment serves as an important contextual or encoding cue necessary for memory retrieval was considered. It was suggested that prior experience may block RA by enabling rats to differentiate training and treatment conditions.

Evidence for a SAL1-PAP chloroplast retrograde pathway that functions in drought and high light signaling in Arabidopsis.

PubMed

Estavillo, Gonzalo M; Crisp, Peter A; Pornsiriwong, Wannarat; Wirtz, Markus; Collinge, Derek; Carrie, Chris; Giraud, Estelle; Whelan, James; David, Pascale; Javot, Hélène; Brearley, Charles; Hell, Rüdiger; Marin, Elena; Pogson, Barry J

2011-11-01

Compartmentation of the eukaryotic cell requires a complex set of subcellular messages, including multiple retrograde signals from the chloroplast and mitochondria to the nucleus, to regulate gene expression. Here, we propose that one such signal is a phosphonucleotide (3'-phosphoadenosine 5'-phosphate [PAP]), which accumulates in Arabidopsis thaliana in response to drought and high light (HL) stress and that the enzyme SAL1 regulates its levels by dephosphorylating PAP to AMP. SAL1 accumulates in chloroplasts and mitochondria but not in the cytosol. sal1 mutants accumulate 20-fold more PAP without a marked change in inositol phosphate levels, demonstrating that PAP is a primary in vivo substrate. Significantly, transgenic targeting of SAL1 to either the nucleus or chloroplast of sal1 mutants lowers the total PAP levels and expression of the HL-inducible ASCORBATE PEROXIDASE2 gene. This indicates that PAP must be able to move between cellular compartments. The mode of action for PAP could be inhibition of 5' to 3' exoribonucleases (XRNs), as SAL1 and the nuclear XRNs modulate the expression of a similar subset of HL and drought-inducible genes, sal1 mutants accumulate XRN substrates, and PAP can inhibit yeast (Saccharomyces cerevisiae) XRNs. We propose a SAL1-PAP retrograde pathway that can alter nuclear gene expression during HL and drought stress.

Long term evolution of distant retrograde orbits in the Earth-Moon system

NASA Astrophysics Data System (ADS)

Bezrouk, Collin; Parker, Jeffrey S.

2017-09-01

This work studies the evolution of several Distant Retrograde Orbits (DROs) of varying size in the Earth-Moon system over durations up to tens of millennia. This analysis is relevant for missions requiring a completely hands off, long duration quarantine orbit, such as a Mars Sample Return mission or the Asteroid Redirect Mission. Four DROs are selected from four stable size regions and are propagated for up to 30,000 years with an integrator that uses extended precision arithmetic techniques and a high fidelity dynamical model. The evolution of the orbit's size, shape, orientation, period, out-of-plane amplitude, and Jacobi constant are tracked. It has been found that small DROs, with minor axis amplitudes of approximately 45,000 km or less decay in size and period largely due to the Moon's solid tides. Larger DROs (62,000 km and up) are more influenced by the gravity of bodies external to the Earth-Moon system, and remain bound to the Moon for significantly less time.

Vascular Plug Assisted Retrograde Transvenous Obliteration (PARTO) for Gastric Varix Bleeding Patients in the Emergent Clinical Setting

PubMed Central

Yang, Heechul; Lee, Chun Kyon; Kim, Gun Bea

2016-01-01

Purpose To evaluate the technical feasibility and safety of vascular plug assisted retrograde transvenous obliteration (PARTO) for bleeding gastric varix performed in the emergent clinical setting and describe the mid-term clinical results. Materials and Methods From April 2012 to January 2015, emergent PARTO was tried in total 9 patients presented with active gastric varix bleeding. After initial insufficient or failure of endoscopic approach, they underwent PARTO in the emergent clinical setting. Gelatin sponge embolization of both gastrorenal (GR) shunt and gastric varix was performed after retrograde transvenous placement of a vascular plug in GR shunt. Coil assisted RTO (CARTO) was performed in one patient who had challenging GR shunt anatomy for vascular plug placement. Additional embolic materials, such as microcoils and NBCA glue-lipiodol mixture, were required in three patients to enhance complete occlusion of GR shunt or obliteration of competitive collateral vessels. Clinical success was defined as no variceal rebleeding and disappearance of gastric varix. Results All technical and clinical success–i.e., complete GR shunt occlusion and offending gastric varix embolization with immediate bleeding control–was achieved in all 9 patients. There was no procedure-related complication. All cases showed successful clinical outcome during mean follow up of 17 months (12–32 months), evidenced by imaging studies, endoscopy and clinical data. In 4 patients, mild worsening of esophageal varices or transient ascites was noted as portal hypertensive related change. Conclusion Emergent PARTO is technically feasible and safe, with acceptable mid-term clinical results, in treating active gastric varix bleeding. PMID:27189294

Utp9p facilitates Msn5p-mediated nuclear reexport of retrograded tRNAs in Saccharomyces cerevisiae.

PubMed

Eswara, Manoja B K; McGuire, Andrew T; Pierce, Jacqueline B; Mangroo, Dev

2009-12-01

Utp9p is a nucleolar protein that is part of a subcomplex containing several U3 snoRNA-associated proteins including Utp8p, which is a protein that shuttles aminoacyl-tRNAs from the nucleolus to the nuclear tRNA export receptors Los1p and Msn5p in Saccharomyces cerevisiae. Here we show that Utp9p is also an intranuclear component of the Msn5p-mediated nuclear tRNA export pathway. Depletion of Utp9p caused nuclear accumulation of mature tRNAs derived from intron-containing precursors, but not tRNAs made from intronless pre-tRNAs. Utp9p binds tRNA directly and saturably, and copurifies with Utp8p, Gsp1p, and Msn5p, but not with Los1p or aminoacyl-tRNA synthetases. Utp9p interacts directly with Utp8p, Gsp1p, and Msn5p in vitro. Furthermore, Gsp1p forms a complex with Msn5p and Utp9p in a tRNA-dependent manner. However, Utp9p does not shuttle between the nucleus and the cytoplasm. Because tRNA splicing occurs in the cytoplasm and the spliced tRNAs are retrograded back to the nucleus, we propose that Utp9p facilitates nuclear reexport of retrograded tRNAs. Moreover, the data suggest that Utp9p together with Utp8p translocate aminoacyl-tRNAs from the nucleolus to Msn5p and assist with formation of the Msn5p-tRNA-Gsp1p-GTP export complex.

A case of persistent retrograde amnesia following a dissociative fugue: neuropsychological and neurofunctional underpinnings of loss of autobiographical memory and self-awareness.

PubMed

Hennig-Fast, Kristina; Meister, Franziska; Frodl, Thomas; Beraldi, Anna; Padberg, Frank; Engel, Rolf R; Reiser, Maximilian; Möller, Hans-Jürgen; Meindl, Thomas

2008-10-01

Autobiographical memory relies on complex interactions between episodic memory contents, associated emotions and a sense of self-continuity over the course of one's life. This paper reports a study based upon the case of the patient NN who suffered from a complete loss of autobiographical memory and awareness of identity subsequent to a dissociative fugue. Neuropsychological, behavioral, and functional neuroimaging tests converged on the conclusion that NN suffered from a selective retrograde amnesia following an episode of dissociative fugue, during which he had lost explicit knowledge and vivid memory of his personal past. NN's loss of self-related memories was mirrored in neurobiological changes after the fugue whereas his semantic memory remained intact. Although NN still claimed to suffer from a stable loss of autobiographical, self-relevant memories 1 year after the fugue state, a proportionate improvement in underlying fronto-temporal neuronal networks was evident at this point in time. In spite of this improvement in neuronal activation, his anterograde visual memory had been decreased. It is posited that our data provide evidence for the important role of visual processing in autobiographical memory as well as for the efficiency of protective control mechanisms that constitute functional retrograde amnesia.