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Sample records for medullary thick ascending

  1. Transport defects of rabbit medullary thick ascending limb cells in obstructive nephropathy.

    PubMed Central

    Hwang, S J; Haas, M; Harris, H W; Silva, P; Yalla, S; Sullivan, M R; Otuechere, G; Kashgarian, M; Zeidel, M L

    1993-01-01

    To characterize the sodium transport defect responsible for salt wasting in obstructive nephropathy, the major sodium transporters in the medullary thick ascending limb (mTAL), the apical Na-K-2Cl cotransporter and the basolateral Na-K-ATPase, were studied in fresh suspensions of mTAL cells and outer medulla plasma membranes prepared from obstructed and untreated kidneys. Oxygen consumption (QO2) studies in intact cells revealed marked reductions in the inhibitory effects of both furosemide and ouabain on QO2 in cells from obstructed, as compared with control animals, indicating a reduction in activities of both the Na-K-2Cl cotransporter and the Na-K-ATPase. Saturable [3H]bumetanide binding was reduced in membranes isolated from obstructed kidneys, but the Kd for [3H]bumetanide was unchanged, indicating a decrease in the number of functional luminal Na-K-2Cl cotransporters in obstructed mTAL. Ouabain sensitive Na-K-ATPase activity in plasma membranes was also reduced, and immunoblots using specific monoclonal antibodies directed against the alpha and beta subunits of rabbit Na-K-ATPase showed decreased amounts of both subunits in outer medullas of obstructed kidney. A significant decrease in [3H]bumetanide binding was detected after 4 h of ureteral obstruction, whereas Na-K-ATPase activity at this time was still not different from control. We conclude that ureteral obstruction reduces the amounts of both luminal Na-K-2Cl cotransporter and basolateral Na-K-ATPase in mTAL of obstructed kidney and that these reductions contribute to the salt wasting observed after release of obstruction. Images PMID:8380811

  2. Effect of vasopressin on electrical potential difference and chloride transport in mouse medullary thick ascending limb of Henle's loop.

    PubMed Central

    Hall, D A; Varney, D M

    1980-01-01

    Medullary thick ascending limbs of Henle's loop of the Swiss-Webster mouse were perfused in vitro with an isotonic perfusate and a Ringer's bathing medium. In five studies, addition of a supramaximal concentration of synthetic arginine vasopressin (AVP) to the bathing medium resulted in an increase in electrical potential difference (PD) from 5.0 +/- 1.5 mV, lumen positive, to 10.7 +/- 1.4 mV (P < 0.001). When AVP was removed, the PD returned to 2.6 +/- 0.9 mV (P < 0.001), then increased again to 6.9 +/- 1.7 mV (P < 0.01) when AVP was added a second time. A significant, but submaximal, increase in PD of 2.3 +/- 0.6 MV (P < 0.05) was observed in five medullary thick ascending limbs when AVP was added to the bathing medium at a concentration of 10 microunits/ml. This increase was approximately one-third of the response observed at a concentration of 100 microunits/ml in the same tubule. No further increment in PD was observed in five medullary thick ascending limbs when the AVP concentration was increased from 100 to 1,000 microunits/ml. In seven thick ascendcing limbs, the effect of AVP on PD was reproduced by the addition of 8-[p-chlorophenylthio]-cyclic 3',5'-adenosine monophosphate to the bathing medium at a final concentration of 0.1 mM. AVP increased unidirectional chloride flux from lumen to bath from 29.3 +/- 3.2 to 69.8 +/- 6.2 peq/cm per s (P < 0.001) in spite of an increase in the lumen positive PD from 1.6 +/- 0.5 mV to 7.0 +/- 0.6 mV (P < 0.001). Unidirectional chloride flux from bath to lumen was not affected by AVP. In another series of experiments, net chloride flux increased from 15.6 +/- 3.0 to 41.7 +/- 5.3 peq/cm per s (P < 0.05) after addition of AVP. The effect of AVP on hydraulic water permeability (Lp) was examined by adding raffinose to the bathing medium in both the presence and the absence of AVP. The calculated Lp of 16 +/- 2 nm/s per atm in the absence of AVP, although very low, was significantly different from zero (P < 0.01). However

  3. Enhanced amiloride-sensitive superoxide production in renal medullary thick ascending limb of Dahl salt-sensitive rats.

    PubMed

    O'Connor, Paul M; Lu, Limin; Schreck, Carlos; Cowley, Allen W

    2008-09-01

    The aims of the present study were to determine whether superoxide (O(2)(-)) production is enhanced in medullary thick ascending limb (mTAL) of Dahl salt-sensitive (SS) rats compared with a salt-resistant consomic control strain (SS.13(BN)) and to elucidate the cellular pathways responsible for augmented O(2)(-) production. Studies were carried out in 7- to 10-wk-old male SS and SS.13(BN) rats fed either a 0.4% NaCl diet or a 4.0% NaCl diet for 3 days before tissue harvest. Tissue strips containing mTAL were isolated from the left kidney, loaded with the O(2)(-)-sensitive fluorescent dye dihydroethidium, superfused with modified Hanks' solution, and imaged at x60 magnification on a heated microscope stage. O(2)(-) production was stimulated in mTAL by incrementing superfusate NaCl concentration from 154 to 254 to 500 mM. O(2)(-) production was enhanced in mTAL of SS rats compared with SS.13(BN) rats in response to incrementing bath NaCl. Addition of N-methyl-amiloride (100 muM) or inhibition of NAD(P)H oxidase reduced O(2)(-) production in SS mTAL to levels observed in SS.13(BN) rats. Both amiloride- and ouabain-sensitive pathways of O(2)(-) production were elevated following 3 days of high (4.0%) NaCl feeding in mTAL of SS and SS.13(BN) rats. We conclude that mTAL from SS rats exhibit enhanced amiloride-sensitive O(2)(-) production. The amiloride-sensitive O(2)(-) response in mTAL is independent of active Na(+) transport and appears to be mediated by NAD(P)H oxidase. Amiloride-sensitive O(2)(-) production is likely to contribute to augmented outer medullary O(2)(-) production observed in SS rats during both normal and high NaCl diets.

  4. Luminal angiotensin II stimulates rat medullary thick ascending limb chloride transport in the presence of basolateral norepinephrine.

    PubMed

    Baum, Michel

    2016-02-15

    Angiotensin II (ANG II) is secreted by the proximal tubule resulting in a luminal concentration that is 100- to 1,000-fold greater than that in the blood. Luminal ANG II has been shown to stimulate sodium transport in the proximal tubule and distal nephron. Surprisingly, luminal ANG II inhibits NaCl transport in the medullary thick ascending limb (mTAL), a nephron segment responsible for a significant amount of NaCl absorption from the glomerular ultrafiltrate. We confirmed that addition of 10(-8) M ANG II to the lumen inhibited mTAL chloride transport (220 ± 19 to 165 ± 25 pmol·mm(-1)·min(-1), P < 0.01) and examined whether an interaction with basolateral norepinephrine existed to simulate the in vivo condition of an innervated tubule. We found that in the presence of a 10(-6) M norepinephrine bath, luminal ANG II stimulated mTAL chloride transport from 298 ± 18 to 364 ± 42 pmol·mm(-1)·min(-1) (P < 0.05). Stimulation of chloride transport by luminal ANG II was also observed with 10(-3) M bath dibutyryl cAMP in the bathing solution and bath isoproterenol. A bath of 10(-5) H-89 blocked the stimulation of chloride transport by norepinephrine and prevented the effect of luminal ANG II to either stimulate or inhibit chloride transport. Bath phentolamine, an α-adrenergic agonist, also prevented the decrease in mTAL chloride transport by luminal ANG II. Thus luminal ANG II increases chloride transport with basolateral norepinephrine; an effect likely mediated by stimulation of cAMP. Alpha-1 adrenergic stimulation prevents the inhibition of chloride transport by luminal ANG II.

  5. Sodium-bicarbonate cotransporter NBCn1 in the kidney medullary thick ascending limb cell line is upregulated under acidic conditions and enhances ammonium transport.

    PubMed

    Lee, Soojung; Lee, Hye Jeong; Yang, Han Soo; Thornell, Ian M; Bevensee, Mark O; Choi, Inyeong

    2010-09-01

    In this study, we examined the effect of bicarbonate transporters on ammonium/ammonia uptake in the medullary thick ascending limb cell line ST-1. Cells were treated with 1 mm ouabain and 0.2 mM bumetanide to minimize carrier-mediated NH(4)(+) transport, and the intracellular accumulation of (14)C-methylammonium/methylammonia ((14)C-MA) was determined. In CO(2)/HCO(3)(-)-free solution, cells at normal pH briefly accumulated (14)C-MA over 7 min and reached a plateau. In CO(2)/HCO(3)(-) solution, however, cells markedly accumulated (14)C-MA over the experimental period of 30 min. This CO(2)/HCO(3)(-)-dependent accumulation was reduced by the bicarbonate transporter blocker, 4,4-diisothiocyanatostilbene-2,2-disulfonate (DIDS; 0.5 mM). Replacing Cl(-) with gluconate reduced the accumulation, but the reduction was more substantial in the presence of DIDS. Incubation of cells at pH 6.8 (adjusted with NaHCO(3) in 5% CO(2)) for 24 h lowered the mean steady-state intracellular pH to 6.96, significantly lower than 7.28 for control cells. The presence of DIDS reduced (14)C-MA accumulation in control conditions but had no effect after acidic incubation. Immunoblotting showed that NBCn1 was upregulated after acidic incubation and in NH(4)Cl-containing media. The Cl(-)-HCO(3)(-) exchanger AE2 was present, but its expression remained unaffected by acidic incubation. Expressed in Xenopus oocytes, NBCn1 increased carrier-mediated (14)C-MA transport, which was abolished by replacing Na(+). Two-electrode voltage clamp of oocytes exhibited negligible current after NH(4)Cl application. These results suggest that DIDS-sensitive HCO(3)(-) extrusion normally governs NH(4)(+)/NH(3) uptake in the medullary thick ascending limb cells. We propose that, in acidic conditions, DIDS-sensitive HCO(3)(-) extrusion is inactivated, while NBCn1 is upregulated to stimulate NH(4)(+) transport.

  6. High sodium intake increases HCO(3)- absorption in medullary thick ascending limb through adaptations in basolateral and apical Na+/H+ exchangers.

    PubMed

    Good, David W; George, Thampi; Watts, Bruns A

    2011-08-01

    A high sodium intake increases the capacity of the medullary thick ascending limb (MTAL) to absorb HCO(3)(-). Here, we examined the role of the apical NHE3 and basolateral NHE1 Na(+)/H(+) exchangers in this adaptation. MTALs from rats drinking H(2)O or 0.28 M NaCl for 5-7 days were perfused in vitro. High sodium intake increased HCO(3)(-) absorption rate by 60%. The increased HCO(3)(-) absorptive capacity was mediated by an increase in apical NHE3 activity. Inhibiting basolateral NHE1 with bath amiloride eliminated 60% of the adaptive increase in HCO(3)(-) absorption. Thus the majority of the increase in NHE3 activity was dependent on NHE1. A high sodium intake increased basolateral Na(+)/H(+) exchange activity by 89% in association with an increase in NHE1 expression. High sodium intake increased apical Na(+)/H(+) exchange activity by 30% under conditions in which basolateral Na(+)/H(+) exchange was inhibited but did not change NHE3 abundance. These results suggest that high sodium intake increases HCO(3)(-) absorptive capacity in the MTAL through 1) an adaptive increase in basolateral NHE1 activity that results secondarily in an increase in apical NHE3 activity; and 2) an adaptive increase in NHE3 activity, independent of NHE1 activity. These studies support a role for NHE1 in the long-term regulation of renal tubule function and suggest that the regulatory interaction whereby NHE1 enhances the activity of NHE3 in the MTAL plays a role in the chronic regulation of HCO(3)(-) absorption. The adaptive increases in Na(+)/H(+) exchange activity and HCO(3)(-) absorption in the MTAL may play a role in enabling the kidneys to regulate acid-base balance during changes in sodium and volume balance.

  7. High-mobility group box 1 inhibits HCO3− absorption in medullary thick ascending limb through a basolateral receptor for advanced glycation end products pathway

    PubMed Central

    George, Thampi; Watts, Bruns A.

    2015-01-01

    High-mobility group box 1 (HMGB1) is a damage-associated molecule implicated in mediating kidney dysfunction in sepsis and sterile inflammatory disorders. HMGB1 is a nuclear protein released extracellularly in response to infection or injury, where it interacts with Toll-like receptor 4 (TLR4) and other receptors to mediate inflammation. Previously, we demonstrated that LPS inhibits HCO3- absorption in the medullary thick ascending limb (MTAL) through a basolateral TLR4-ERK pathway (Watts BA III, George T, Sherwood ER, Good DW. Am J Physiol Cell Physiol 301: C1296–C1306, 2011). Here, we examined whether HMGB1 could inhibit HCO3- absorption through the same pathway. Adding HMGB1 to the bath decreased HCO3− absorption by 24% in isolated, perfused rat and mouse MTALs. In contrast to LPS, inhibition by HMGB1 was preserved in MTALs from TLR4−/− mice and was unaffected by ERK inhibitors. Inhibition by HMGB1 was eliminated by the receptor for advanced glycation end products (RAGE) antagonist FPS-ZM1 and by neutralizing anti-RAGE antibody. Confocal immunofluorescence showed expression of RAGE in the basolateral membrane domain. Inhibition of HCO3−absorption by HMGB1 through RAGE was additive to inhibition by LPS through TLR4 and to inhibition by Gram-positive bacterial molecules through TLR2. Bath amiloride, which selectively prevents inhibition of MTAL HCO3− absorption mediated through Na+/H+ exchanger 1 (NHE1), eliminated inhibition by HMGB1. We conclude that HMGB1 inhibits MTAL HCO3− absorption through a RAGE-dependent pathway distinct from TLR4-mediated inhibition by LPS. These studies provide new evidence that HMGB1-RAGE signaling acts directly to impair the transport function of renal tubules. They reveal a novel paradigm for sepsis-induced renal tubule dysfunction, whereby exogenous pathogen-associated molecules and endogenous damage-associated molecules act directly and independently to inhibit MTAL HCO3− absorption through different receptor

  8. A novel amiloride-sensitive h+ transport pathway mediates enhanced superoxide production in thick ascending limb of salt-sensitive rats, not na+/h+ exchange.

    PubMed

    O'Connor, Paul M; Lu, Limin; Liang, Mingyu; Cowley, Allen W

    2009-08-01

    It has been reported previously that H(+) efflux via the Na(+)/H(+) exchange stimulates NAD(P)H oxidase-dependent superoxide (O(2)(.-)) production in medullary thick ascending limb. We have demonstrated recently that N-methyl-amiloride-sensitive O(2)(.-) production is enhanced in the thick ascending limb of Dahl salt-sensitive (SS) rats, suggesting that H(+) efflux through Na(+)/H(+) exchangers may promote renal oxidative stress and the development of hypertension in these animals. In the current study we demonstrate, using selective and potent inhibitors, that inhibition of Na(+)/H(+) exchange does not mediate the ability of N-methyl-amiloride to inhibit thick ascending limb O(2)(.-) production. To determine the mechanism of action of N-methyl-amiloride, we examined H(+) efflux and O(2)(.-) production in SS and SS.13(BN) thick ascending limbs of prehypertensive, 0.4% NaCl-fed rats. Tissue strips containing the medullary thick ascending limb were isolated from male SS and salt-resistant consomic SS.13(BN) rats, loaded with either dihydroethedium or 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester, and imaged in a heated tissue bath. In Na(+)-replete media, activation of Na(+)/H(+) exchange using an NH(4)Cl prepulse did not stimulate thick ascending limb O(2)(.-) production. In Na(+)-free media containing BaCl(2) in which Na(+)/H(+) activity was inhibited, an NH(4)Cl prepulse stimulated O(2)(.-) production in medullary thick ascending limb renal tubular segments. This response was enhanced in medullary thick ascending limb of SS rats (slope Deltaethidium/Deltadihydroethedium=0.029+/-0.004) compared with SS.13(BN) rats (slope=0.010+/-0.004; P<0.04) and could be inhibited by N-methyl-amiloride (slope=0.005+/-0.002 and 0.006+/-0.002 for SS and SS.13(BN), respectively). We concluded that only H(+) efflux through a specific, as-yet-unidentified, amiloride-sensitive H(+) channel promotes O(2)(.-) production in the medullary thick ascending limb

  9. PGE2 inhibits basolateral 50 pS potassium channels in the thick ascending limb of the rat kidney

    PubMed Central

    Gu, Ruimin; Jin, Yan; Zhai, Yuanyuan; Yang, Lei; Zhang, Chengbiao; Li, Wennan; Wang, lijun; Kong, Shumin; Zhang, Yunhong; Yang, Baofeng; Wang, Wen-Hui

    2010-01-01

    To study the inhibition of the inwardly rectifying basolateral 50 pS potassium channels by PGE2 we performed patch-clamp studies on the basolateral membrane of the rat kidney thick ascending limb. PGE2's effect was mimicked by the selective EP1- and EP3-receptor agonist, sulprostone, but was prevented by inhibiting protein kinase-C with calphostin-C. The mitogen-activated protein kinase inhibitor PD98059 (ERK) or SB203580 (p38) increased basal channel activity; however, while neither alone prevented the inhibitory effect of PGE2, but using both of them together completely abolished PGE2's effect on channel activity. Treatment with PGE2 stimulated phosphorylation of both p38 and ERK in primary cultures of medullary thick ascending limb cells. The PGE2-mediated mitogen-activated protein kinase activation was not affected by indomethacin, but was completely blocked by calphostin-C. These studies show that inhibition of basolateral 50 pS potassium channels by PGE2 is mediated by protein kinase-C, which in turn stimulates mitogen-activated protein kinases in the thick ascending limb of the rat kidney. PMID:18496512

  10. Desensitization of rat renal thick ascending limb cells to vasopressin.

    PubMed Central

    Elalouf, J M; Sari, D C; Roinel, N; de Rouffignac, C

    1988-01-01

    Previous studies from this laboratory have demonstrated that vasopressin stimulates K, Mg, Ca, Cl, and Na reabsorption by the thick ascending limb of Henle's loop (TALH) of the rat kidney. Micropuncture of superficial nephrons and clearance experiments were performed to determine whether desensitization of the TALH to vasopressin may be demonstrated in vivo and whether such desensitization is specific for the effects of vasopressin (i.e., homologous) or also alters the response to the other hormones acting on the same pool of adenylate cyclase in this nephron segment. Brattleboro rats, with hereditary hypothalamic diabetes insipidus (DI), were given i.m. injections of 1-desamino-8-D-arginine-vasopressin (des-1-amino-[DArg8]VP (herein designated dDAVP); 2 micrograms/day) for 3 days. The effects of maximal physiological doses of arginine-8-vasopressin ([Arg8]VP (herein designated AVP); 20 pg/min per 100 g of body weight) were studied 2 days after the cessation of treatment, when the animals had returned to DI. The K, Mg, Ca, and, to a lesser extent, Cl and Na concentrations in the fluid leaving the TALH of superficial nephrons were higher in dDAVP-treated than in untreated rats given similar amounts of AVP during the experiments. A 50-60% desensitization of the TALH to AVP was still apparent 2 days after stopping the dDAVP injections. Desensitization is homologous, as judged from normal responses to physiological doses of glucagon and calcitonin, two hormones acting on the same cyclase pool as AVP in the rat TALH. The AVP-dependent increase of urine osmolality, however, indicated that its effects on the permeability to water of the collecting duct were scarcely affected in dDAVP-treated rats. It is concluded that (i) AVP induces homologous desensitization in the rat TALH and (ii) the TALH can be markedly desensitized to AVP when the collecting duct response to this hormone is poorly affected or even fully maintained. PMID:3353389

  11. Fluid dilution and efficiency of Na+ transport in a mathematical model of a thick ascending limb cell

    PubMed Central

    Clausen, Chris; Marcano, Mariano; Layton, Anita T.; Layton, Harold E.; Moore, Leon C.

    2013-01-01

    Thick ascending limb (TAL) cells are capable of reducing tubular fluid Na+ concentration to as low as ∼25 mM, and yet they are thought to transport Na+ efficiently owing to passive paracellular Na+ absorption. Transport efficiency in the TAL is of particular importance in the outer medulla where O2 availability is limited by low blood flow. We used a mathematical model of a TAL cell to estimate the efficiency of Na+ transport and to examine how tubular dilution and cell volume regulation influence transport efficiency. The TAL cell model represents 13 major solutes and the associated transporters and channels; model equations are based on mass conservation and electroneutrality constraints. We analyzed TAL transport in cells with conditions relevant to the inner stripe of the outer medulla, the cortico-medullary junction, and the distal cortical TAL. At each location Na+ transport efficiency was computed as functions of changes in luminal NaCl concentration ([NaCl]), [K+], [NH4+], junctional Na+ permeability, and apical K+ permeability. Na+ transport efficiency was calculated as the ratio of total net Na+ transport to transcellular Na+ transport. Transport efficiency is predicted to be highest at the cortico-medullary boundary where the transepithelial Na+ gradient is the smallest. Transport efficiency is lowest in the cortex where luminal [NaCl] approaches static head. PMID:23097469

  12. Cortical thickness and medullary canal dimensions of the bone phalanx are predicted by quantitative ultrasound parameters.

    PubMed

    Guglielmi, Giuseppe; de Terlizzi, Francesca; Scalzo, Giacomo; Battista, Claudia; Scillitani, Alfredo

    2010-01-01

    The aim of the study was to investigate the relationship between quantitative ultrasound (QUS) parameters extracted from the analysis of the ultrasound (US) signal and the geometric properties of the bones. One hundred and one subjects in the age range of 20-7 4yr (mean: 52+/-12 yr) have been measured by QUS at the phalanges for the evaluation of amplitude-dependent speed of sound (AD-SoS), bone transmission time (BTT), US peak amplitude (UPA), signal dynamic (SDY), slope, energy, and fast wave amplitude (FWA). Hand radiograph, lumbar spine dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT), and femoral neck DXA forearm peripheral QCT were performed on all patients. BTT is related to cortical thickness (CTh) (r=0.62, p<0.0001), and FWA is related to medullary canal thickness (r=-0.64, p<0.0001). Other parameters are related to both medullary canal thickness (AD-SoS: r=-0.21; UPA: r=-0.53; SDY: r=-0.56; slope: r=-0.64; energy: r=-0.44, p<0.05) and CTh (AD-SoS: r=0.54, p<0.0001; UPA: r=0.51; SDY: r=0.38; slope: r=0.32; energy: r=0.56, p<0.001). Linear multivariate models indicate that BTT, UPA, and energy measured at the phalanges carry independent information on CTh of the bone, whereas FWA, SDY, and slope are related only to medullary canal thickness.

  13. Angiotensin II stimulates superoxide production by nitric oxide synthase in thick ascending limbs.

    PubMed

    Gonzalez-Vicente, Agustin; Saikumar, Jagannath H; Massey, Katherine J; Hong, Nancy J; Dominici, Fernando P; Carretero, Oscar A; Garvin, Jeffrey L

    2016-02-01

    Angiotensin II (Ang II) causes nitric oxide synthase (NOS) to become a source of superoxide (O2 (-)) via a protein kinase C (PKC)-dependent process in endothelial cells. Ang II stimulates both NO and O2 (-) production in thick ascending limbs. We hypothesized that Ang II causes O2 (-) production by NOS in thick ascending limbs via a PKC-dependent mechanism. NO production was measured in isolated rat thick ascending limbs using DAF-FM, whereas O2 (-) was measured in thick ascending limb suspensions using the lucigenin assay. Consistent stimulation of NO was observed with 1 nmol/L Ang II (P < 0.001; n = 9). This concentration of Ang II-stimulated O2 (-) production by 50% (1.77 ± 0.26 vs. 2.62 ± 0.36 relative lights units (RLU)/s/μg protein; P < 0.04; n = 5). In the presence of the NOS inhibitor L-NAME, Ang II-stimulated O2 (-) decreased from 2.02 ± 0.29 to 1.10 ± 0.11 RLU/s/μg protein (P < 0.01; n = 8). L-arginine alone did not change Ang II-stimulated O2 (-) (2.34 ± 0.22 vs. 2.29 ± 0.29 RLU/s/μg protein; n = 5). In the presence of Ang II plus the PKC α/β1 inhibitor Gö 6976, L-NAME had no effect on O2 (-) production (0.78 ± 0.23 vs. 0.62 ± 0.11 RLU/s/μg protein; n = 7). In the presence of Ang II plus apocynin, a NADPH oxidase inhibitor, L-NAME did not change O2 (-) (0.59 ± 0.04 vs. 0.61 ± ×0.08 RLU/s/μg protein; n = 5). We conclude that: (1) Ang II causes NOS to produce O2 (-) in thick ascending limbs via a PKC- and NADPH oxidase-dependent process; and (2) the effect of Ang II is not due to limited substrate.

  14. Sensitivities of rat kidney thick ascending limbs and collecting ducts to vasopressin in vivo.

    PubMed Central

    Elalouf, J M; Di Stefano, A; de Rouffignac, C

    1986-01-01

    Clearance experiments were performed to characterize the sensitivity to vasopressin of the thick ascending limbs and collecting duct system of the rat kidney. The response of the thick ascending limbs was evaluated by measuring the Mg2+ excretion rate in the urine, since the [arginine-8] vasopressin-mediated effects on Mg2+ excretion are the direct result of a stimulation of Mg2+ reabsorption in this nephron segment, and the response of the collecting ducts was evaluated by changes in urine flow. To avoid the effects of parathyroid hormone, glucagon, and calcitonin, which stimulate Mg2+ reabsorption in the thick ascending limb and distal tubule, and of calcitonin, which increases the permeability of the cortical collecting ducts to water, experiments were performed on Brattleboro D. I. rats (with hereditary diabetes insipidus, due to a lack of [Arg8]vasopressin) acutely deprived of endogenous parathyroid hormone, calcitonin, and glucagon. Vasopressin infused at rates up to 5 pg/min did not reduce the Mg2+ fractional excretion rate, whereas at 5 pg/min water excretion was decreased by 50%. The half-maximal reduction of Mg2+ excretion occurred at vasopressin infusion rates 4-6 times higher than those necessary to diminish the water excretion rate to the same extent. We conclude that in vivo, two segments involved in the production of concentrated urine have different sensitivities to vasopressin and that this difference in sensitivity is very similar for the biological response in vivo and the adenylate cyclase activation in vitro. We suggest that both the magnitude and the nature of the effects of [Arg8]vasopressin on the kidney may vary according to the required antidiuretic response. PMID:3457386

  15. Ascending caudal medullary catecholamine pathways drive sickness-induced deficits in exploratory behavior: brain substrates for fatigue?

    PubMed

    Gaykema, Ronald P A; Goehler, Lisa E

    2011-03-01

    immune-sensory caudal brainstem sources target distinct populations of forebrain neurons that likely mediate different aspects of sickness. The caudal medullary catecholaminergic projections to the hypothalamus may significantly contribute to brain mechanisms that induce behavioral "fatigue" in the context of physiological stressors.

  16. Acute application of TNF stimulates apical 70-pS K+ channels in the thick ascending limb of rat kidney.

    PubMed

    Wei, Yuan; Babilonia, Elisa; Pedraza, Paulina L; Ferreri, Nicholas R; Wang, Wen-Hui

    2003-09-01

    TNF has been shown to be synthesized by the medullary thick ascending limb (mTAL) (21). In the present study, we used the patch-clamp technique to study the acute effect of TNF on the apical 70-pS K+ channel in the mTAL. Addition of TNF (10 nM) significantly stimulated activity of the 70-pS K+ channel and increased NPo [a product of channel open probability (Po) and channel number (N)] from 0.20 to 0.97. The stimulatory effect of TNF was observed only in cell-attached patches but not in excised patches. Moreover, addition of TNF had no effect on the ROMK-like small-conductance K+ channels in the TAL. The dose-response curve of the TNF effect yielded a Km value of 1 nM, a concentration that increased channel activity to 50% maximal stimulatory effect of TNF. The concentrations required for reaching the plateau of the TNF effect were between 5 and 10 nM. The stimulatory effect of TNF on the 70-pS K+ channel was observed in the presence of N(omega)-nitro-L-arginine methyl ester. This indicated that the effect of TNF was not mediated by a nitric oxide-dependent pathway. Also, inhibition of PKA did not affect the stimulatory effect of TNF. In contrast, inhibition of protein tyrosine kinase not only increased activity of the 70-pS K+ channel but also abolished the effect of TNF. Moreover, inhibition of protein tyrosine phosphatase (PTP) blocked the stimulatory effect of TNF on the 70-pS K+ channel. The notion that the TNF effect results from stimulation of PTP activity is supported by PTP activity assay in which treatment of mTAL cells with TNF significantly increased the activity of PTP. We conclude that TNF stimulates the 70-pS K+ channel via stimulation of PTP in the mTAL.

  17. Apoptosis of the Thick Ascending Limb Results in Acute Kidney Injury

    PubMed Central

    Srichai, Manakan B.; Hao, Chuanming; Davis, Linda; Golovin, Anastasia; Zhao, Min; Moeckel, Gilbert; Dunn, Steve; Bulus, Nada; Harris, Raymond C.; Zent, Roy; Breyer, Matthew D.

    2008-01-01

    Ischemia- or toxin-induced acute kidney injury is generally thought to affect the cells of the proximal tubule, but it has been difficult to define the involvement of other tubular segments because of the widespread damage caused by ischemia/reperfusion or toxin-induced injury in experimental models. For evaluation of whether thick ascending limb (TAL)-specific epithelial injury results in acute kidney injury, a novel transgenic mouse model that expresses the herpes simplex virus 1 thymidine kinase gene under the direction of the TAL-specific Tamm-Horsfall protein promoter was generated. After administration of gancyclovir, these mice demonstrated apoptosis only in TAL cells, with little evidence of neutrophil infiltration. Compared with control mice, blood urea nitrogen and creatinine levels were at least five-fold higher in the transgenic mice, which also developed oliguria and impaired urinary concentrating ability. These findings suggest that acute injury targeted only to the TAL is sufficient to cause severe acute kidney injury in mice with features similar to those observed in humans. PMID:18495962

  18. Apoptosis of the thick ascending limb results in acute kidney injury.

    PubMed

    Srichai, Manakan B; Hao, Chuanming; Davis, Linda; Golovin, Anastasia; Zhao, Min; Moeckel, Gilbert; Dunn, Steve; Bulus, Nada; Harris, Raymond C; Zent, Roy; Breyer, Matthew D

    2008-08-01

    Ischemia- or toxin-induced acute kidney injury is generally thought to affect the cells of the proximal tubule, but it has been difficult to define the involvement of other tubular segments because of the widespread damage caused by ischemia/reperfusion or toxin-induced injury in experimental models. For evaluation of whether thick ascending limb (TAL)-specific epithelial injury results in acute kidney injury, a novel transgenic mouse model that expresses the herpes simplex virus 1 thymidine kinase gene under the direction of the TAL-specific Tamm-Horsfall protein promoter was generated. After administration of gancyclovir, these mice demonstrated apoptosis only in TAL cells, with little evidence of neutrophil infiltration. Compared with control mice, blood urea nitrogen and creatinine levels were at least five-fold higher in the transgenic mice, which also developed oliguria and impaired urinary concentrating ability. These findings suggest that acute injury targeted only to the TAL is sufficient to cause severe acute kidney injury in mice with features similar to those observed in humans.

  19. Acute alloxan renal toxicity in the rat initially causes degeneration of thick ascending limbs of Henle

    PubMed Central

    Terayama, Yui; Kodama, Yasushi; Matsuura, Tetsuro; Ozaki, Kiyokazu

    2016-01-01

    Alloxan (AL) is a material well-known to induce diabetes. Prior to inducing a prolonged diabetic state, AL causes acute tubulointerstitial nephritis. However, the precise primary target site and mechanism of its nephrotoxicity remain unclear. The objective of this study was to evaluate the morphological characteristics relevant to acute renal toxicity following AL administration. Rats were intravenously treated with AL. Eight hours after AL treatment, aquaporin 1-negative and Na/K pump-positive thick ascending limbs of Henle (TAL) were degenerated in the outer medulla. These tubular lesions progressed from the outer medulla to the cortex. At day 2 after AL treatment, the lesions reached a peak, then both proximal and distal tubules also showed degeneration and necrosis, and tubular regeneration was seen in TAL. Immunohistochemically, damaged tubular epithelium included slightly enlarged prohibitin-positive granules, but it expressed no GLUT2, which is an AL transporter. Ultrastructurally, cytoplasmic and mitochondrial swelling was detected in degenerated cells of TAL. These findings suggest that AL initially causes degeneration of TAL, and induces mitochondrial and cellular damage in the tubular epithelium without involving GLUT2. PMID:28190920

  20. Angiotensin II stimulates basolateral 50-pS K channels in the thick ascending limb.

    PubMed

    Wang, Mingxiao; Luan, Haiyan; Wu, Peng; Fan, Lili; Wang, Lijun; Duan, Xinpeng; Zhang, Dandan; Wang, Wen-Hui; Gu, Ruimin

    2014-03-01

    We used the patch-clamp technique to examine the effect of angiotensin II (ANG II) on the basolateral K channels in the thick ascending limb (TAL) of the rat kidney. Application of ANG II increased the channel activity and the current amplitude of the basolateral 50-pS K channel. The stimulatory effect of ANG II on the K channels was completely abolished by losartan, an inhibitor of type 1 angiotensin receptor (AT1R), but not by PD123319, an AT2R antagonist. Moreover, inhibition of phospholipase C (PLC) and protein kinase C (PKC) also abrogated the stimulatory effect of ANG II on the basolateral K channels in the TAL. This suggests that the stimulatory effect of ANG II on the K channels was induced by activating PLC and PKC pathways. Western blotting demonstrated that ANG II increased the phosphorylation of c-Src at tyrosine residue 416, an indication of c-Src activation. This effect was mimicked by PKC stimulator but abolished by calphostin C. Moreover, inhibition of NADPH oxidase (NOX) also blocked the effect of ANG II on c-Src tyrosine phosphorylation. The role of Src-family protein tyrosine kinase (SFK) in mediating the effect of ANG II on the basolateral K channel was further suggested by the experiments in which inhibition of SFK abrogated the stimulatory effect of ANG II on the basolateral 50-pS K channel. We conclude that ANG II increases basolateral 50-pS K channel activity via AT1R and that activation of AT1R stimulates SFK by a PLC-PKC-NOX-dependent mechanism.

  1. Angiotensin II-induced hypertension blunts thick ascending limb NO production by reducing NO synthase 3 expression and enhancing threonine 495 phosphorylation.

    PubMed

    Ramseyer, Vanesa D; Gonzalez-Vicente, Agustin; Carretero, Oscar A; Garvin, Jeffrey L

    2015-01-15

    Thick ascending limbs reabsorb 30% of the filtered NaCl load. Nitric oxide (NO) produced by NO synthase 3 (NOS3) inhibits NaCl transport by this segment. In contrast, chronic angiotensin II (ANG II) infusion increases net thick ascending limb transport. NOS3 activity is regulated by changes in expression and phosphorylation at threonine 495 (T495) and serine 1177 (S1177), inhibitory and stimulatory sites, respectively. We hypothesized that NO production by thick ascending limbs is impaired by chronic ANG II infusion, due to reduced NOS3 expression, increased phosphorylation of T495, and decreased phosphorylation of S1177. Rats were infused with 200 ng·kg(-1)·min(-1) ANG II or vehicle for 1 and 5 days. ANG II infusion for 5 days decreased NOS3 expression by 40 ± 12% (P < 0.007; n = 6) and increased T495 phosphorylation by 147 ± 26% (P < 0.008; n = 6). One-day ANG II infusion had no significant effect. NO production in response to endothelin-1 was blunted in thick ascending limbs from ANG II-infused animals [ANG II -0.01 ± 0.06 arbitrary fluorescence units (AFU)/min vs. 0.17 ± 0.02 AFU/min in controls; P < 0.01]. This was not due to reduced endothelin-1 receptor expression. Phosphatidylinositol 3,4,5-triphosphate (PIP3)-induced NO production was also reduced in ANG II-infused rats (ANG II -0.07 ± 0.06 vs. 0.13 ± 0.04 AFU/min in controls; P < 0.03), and this correlated with an impaired ability of PIP3 to increase S1177 phosphorylation. We conclude that in ANG II-induced hypertension NO production by thick ascending limbs is impaired due to decreased NOS3 expression and altered phosphorylation.

  2. Membrane-associated aquaporin-1 facilitates osmotically driven water flux across the basolateral membrane of the thick ascending limb

    PubMed Central

    Cabral, Pablo D.

    2012-01-01

    The thick ascending limb of the loop of Henle (TAL) reabsorbs ∼30% of filtered NaCl but is impermeable to water. The observation that little water traverses the TAL indicates an absence of water channels at the apical membrane. Yet TAL cells swell when peritubular osmolality decreases indicating that water channels must be present in the basolateral side. Consequently, we hypothesized that the water channel aquaporin-1 (AQP1) facilitates water flux across the basolateral membrane of TALs. Western blotting revealed AQP1 expression in microdissected rat and mouse TALs. Double immunofluorescence showed that 95 ± 2% of tubules positive for the TAL-specific marker Tamm-Horsfall protein were also positive for AQP1 (n = 6). RT-PCR was used to demonstrate presence of AQP1 mRNA and the TAL-specific marker NKCC2 in microdissected TALs. Cell surface biotinylation assays showed that 23 ± 3% of the total pool of AQP1 was present at the TAL basolateral membrane (n = 7). To assess the functional importance of AQP1 in the basolateral membrane, we measured the rate of cell swelling initiated by decreasing peritubular osmolality as an indicator of water flux in microdissected TALs. Water flux was decreased by ∼50% in Aqp1 knockout mice compared with wild-types (4.0 ± 0.8 vs. 8.9 ± 1.7 fluorescent U/s, P < 0.02; n = 7). Furthermore, arginine vasopressin increased TAL AQP1 expression by 135 ± 17% (glycosylated) and 41 ± 11% (nonglycosylated; P < 0.01; n =5). We conclude that 1) the TAL expresses AQP1, 2) ∼23% of the total pool of AQP1 is localized to the basolateral membrane, 3) AQP1 mediates a significant portion of basolateral water flux, and 4) AQP1 is upregulated in TALs of rats infused with dDAVP. AQP1 could play an important role in regulation of TAL cell volume during changes in interstitial osmolality, such as during a high-salt diet or water deprivation. PMID:22674028

  3. Effects of renal perfusion pressure on renal medullary hydrogen peroxide and nitric oxide production.

    PubMed

    Jin, Chunhua; Hu, Chunyan; Polichnowski, Aaron; Mori, Takefumi; Skelton, Meredith; Ito, Sadayoshi; Cowley, Allen W

    2009-06-01

    Studies were designed to determine the effects of increases of renal perfusion pressure on the production of hydrogen peroxide (H(2)O(2)) and NO(2)(-)+NO(3)(-) within the renal outer medulla. Sprague-Dawley rats were studied with either the renal capsule intact or removed to ascertain the contribution of changes of medullary blood flow and renal interstitial hydrostatic pressure on H(2)O(2) and NO(2)(-)+NO(3)(-) production. Responses to three 30-minute step changes of renal perfusion pressure (from approximately 85 to approximately 115 to approximately 145 mm Hg) were studied using adjustable aortic occluders proximal and distal to the left renal artery. Medullary interstitial H(2)O(2) determined by microdialysis increased at each level of renal perfusion pressure from 640 to 874 to 1593 nmol/L, as did H(2)O(2) urinary excretion rates, and these responses were significantly attenuated by decapsulation. Medullary interstitial NO(2)(-)+NO(3)(-) increased from 9.2 to 13.8 to 16.1 mumol/L, with parallel changes in urine NO(2)(-)+NO(3)(-), but decapsulation did not significantly blunt these responses. Over the range of renal perfusion pressure, medullary blood flow (laser-Doppler flowmetry) rose approximately 30% and renal interstitial hydrostatic pressure rose from 7.8 to 19.7 cm H(2)O. Renal interstitial hydrostatic pressure and the natriuretic and diuretic responses were significantly attenuated with decapsulation, but medullary blood flow was not affected. The data indicate that pressure-induced increases of H(2)O(2) emanated largely from increased tubular flow rates to the medullary thick-ascending limbs of Henle and NO largely from increased medullary blood flow to the vasa recta. The parallel pressure-induced increases of H(2)O(2) and NO indicate a participation in shaping the "normal" pressure-natriuresis relationship and explain why an imbalance in either would affect the blood pressure salt sensitivity.

  4. Thyroid cancer - medullary carcinoma

    MedlinePlus

    Thyroid - medullary carcinoma; Cancer - thyroid (medullary carcinoma); MTC; Thyroid nodule - medullary ... in children and adults. Unlike other types of thyroid cancer, MTC is less likely to be caused by ...

  5. Vesicle-associated Membrane Protein 3 (VAMP3) Mediates Constitutive Trafficking of the Renal Co-transporter NKCC2 in Thick Ascending Limbs

    PubMed Central

    Caceres, Paulo S.; Mendez, Mariela; Haque, Mohammed Z.; Ortiz, Pablo A.

    2016-01-01

    Renal cells of the thick ascending limb (TAL) reabsorb NaCl via the apical Na+/K+/2Cl− co-transporter NKCC2. Trafficking of NKCC2 to the apical surface regulates NKCC2-mediated NaCl absorption and blood pressure. The molecular mechanisms by which NKCC2 reaches the apical surface and their role in renal function and maintenance of blood pressure are poorly characterized. Here we report that NKCC2 interacts with the vesicle fusion protein VAMP3, and they co-localize at the TAL apical surface. We observed that silencing VAMP3 in vivo blocks constitutive NKCC2 exocytic delivery, decreasing the amount of NKCC2 at the TAL apical surface. VAMP3 is not required for cAMP-stimulated NKCC2 exocytic delivery. Additionally, genetic deletion of VAMP3 in mice decreased total expression of NKCC2 in the TAL and lowered blood pressure. Consistent with these results, urinary excretion of water and electrolytes was higher in VAMP3 knock-out mice, which produced more diluted urine. We conclude that VAMP3 interacts with NKCC2 and mediates its constitutive exocytic delivery to the apical surface. Additionally, VAMP3 is required for normal NKCC2 expression, renal function, and blood pressure. PMID:27551042

  6. Absence of Small Conductance K+ Channel (SK) Activity in Apical Membranes of Thick Ascending Limb and Cortical Collecting Duct in ROMK (Bartter’s) Knockout Mice*

    PubMed Central

    Lu, Ming; Wang, Tong; Yan, Qingshang; Yang, Xinbo; Dong, Ke; Knepper, Mark A.; Wang, WenHui; Giebisch, Gerhard; Shull, Gary E.; Hebert, Steven C.

    2015-01-01

    The ROMK (Kir1.1; Kcnj1) gene is believed to encode the apical small conductance K+ channels (SK) of the thick ascending limb (TAL) and cortical collecting duct (CCD). Loss-of-function mutations in the human ROMK gene cause Bartter’s syndrome with renal Na+ wasting, consistent with the role of this channel in apical K+ recycling in the TAL that is crucial for NaCl reabsorption. However, the mechanism of renal K+ wasting and hypokalemia that develop in individuals with ROMK Bartter’s syndrome is not apparent given the proposed loss of the collecting duct SK channel. Thus, we generated a colony of ROMK null mice with ~25% survival to adulthood that provides a good model for ROMK Bartter’s syndrome. The remaining 75% of null mice die in less than 14 days after birth. The surviving ROMK null mice have normal gross renal morphology with no evidence of significant hydronephrosis, whereas non-surviving null mice exhibit marked hydronephrosis. ROMK protein expression was absent in TAL and CCD from null mice but exhibited normal abundance and localization in wild-type littermates. ROMK null mice were polyuric and natriuretic with an elevated hematocrit consistent with mild extracellular volume depletion. SK channel activity in TAL and CCD was assessed by patch clamp analysis in ROMK wild-type ROMK(+/+), heterozygous ROMK(+/−), and null ROMK(−/−) mice. In 313 patches with successful seals from the three ROMK genotypes, SK channel activity in ROMK (+/+ and +/−) exhibited normal single channel kinetics. The expression frequencies are as follows: 67 (TAL) and 58% (CCD) in ROMK(+/+); about half that of the wild-type in ROMK(+/−), being 38 (TAL) and 25% (CCD); absent in both TAL or CCD in ROMK(−/−) between 2 and 5 weeks in 15 mice (61 and 66 patches, respectively). The absence of SK channel activity in ROMK null mice demonstrates that ROMK is essential for functional expression of SK channels in both TAL and CCD. Despite loss of ROMK expression, the

  7. alpha(2)-adrenergic receptor-mediated increase in NO production buffers renal medullary vasoconstriction.

    PubMed

    Zou, A P; Cowley, A W

    2000-09-01

    The present study was designed to investigate the role of nitric oxide (NO) in modulating the adrenergic vasoconstrictor response of the renal medullary circulation. In anesthetized rats, intravenous infusion of norepinephrine (NE) at a subpressor dose of 0.1 microgram. kg(-1). min(-1) did not alter renal cortical (CBF) and medullary (MBF) blood flows measured by laser-Doppler flowmetry nor medullary tissue PO(2) (P(m)O(2)) as measured by a polarographic microelectrode. In the presence of the NO synthase inhibitor nitro-L-arginine methyl ester (L-NAME) in the renal medulla, intravenous infusion of NE significantly reduced MBF by 30% and P(m)O(2) by 37%. With the use of an in vivo microdialysis-oxyhemoglobin NO-trapping technique, we found that intravenous infusion of NE increased interstitial NO concentrations by 43% in the renal medulla. NE-stimulated elevations of tissue NO were completely blocked either by renal medullary interstitial infusion of L-NAME or the alpha(2)-antagonist rauwolscine (30 microgram. kg(-1). min(-1)). Concurrently, intavenous infusion of NE resulted in a significant reduction of MBF in the presence of rauwolscine. The alpha(1)-antagonist prazosin (10 microgram. kg(-1). min(-1) renal medullary interstitial infusion) did not reduce the NE-induced increase in NO production, and NE increased MBF in the presence of prazosin. Microdissection and RT-PCR analyses demonstrated that the vasa recta expressed the mRNA of alpha(2B)-adrenergic receptors and that medullary thick ascending limb and collecting duct expressed the mRNA of both alpha(2A)- and alpha(2B)-adrenergic receptors. These subtypes of alpha(2)-adrenergic receptors may mediate NE-induced NO production in the renal medulla. We conclude that the increase in medullary NO production associated with the activation of alpha(2)-adrenergic receptors counteracts the vasoconstrictor effects of NE in the renal medulla and may play an important role in maintaining a constancy of MBF and medullary

  8. The metabolic syndrome induces early changes in the swine renal medullary mitochondria.

    PubMed

    Eirin, Alfonso; Woollard, John R; Ferguson, Christopher M; Jordan, Kyra L; Tang, Hui; Textor, Stephen C; Lerman, Amir; Lerman, Lilach O

    2017-03-11

    The metabolic syndrome (MetS) is associated with nutrient surplus and kidney hyperfiltration, accelerating chronic renal failure. Mitochondria can be overwhelmed by substrate excess, leading to inefficient energy production and thereby tissue hypoxia. Mitochondrial dysfunction is emerging as an important determinant of renal damage, but whether it contributes to MetS-induced renal injury remains unknown. We hypothesized that early MetS induces kidney mitochondrial abnormalities and dysfunction, which would be notable in the vulnerable renal medulla. Pigs were studied after 16 weeks of diet-induced MetS, MetS treated for the last 4 weeks with the mitochondria-targeted peptide elamipretide (0.1 mg/kg SC q.d), and Lean controls (n = 7 each). Single-kidney renal blood flow, glomerular filtration rate, and oxygenation were measured in-vivo, whereas cortical and medullary mitochondrial structure and function and renal injurious pathways were studied ex-vivo. Blood pressure was slightly elevated in MetS pigs, and their renal blood flow and glomerular filtration rate were elevated. Blood oxygen level-dependent magnetic resonance imaging demonstrated that this was associated with medullary hypoxia, whereas cortical oxygenation remained intact. MetS decreased renal content of the inner mitochondrial membrane cardiolipin, particularly the tetra-linoleoyl (C18:2) cardiolipin species, and altered mitochondrial morphology and function, particularly in the medullary thick ascending limb. MetS also increased renal cytochrome-c-induced apoptosis, oxidative stress, and tubular injury. Chronic mitoprotection restored mitochondrial structure, ATP synthesis, and antioxidant defenses and decreased mitochondrial oxidative stress, medullary hypoxia, and renal injury. These findings implicate medullary mitochondrial damage in renal injury in experimental MetS, and position the mitochondria as a therapeutic target.

  9. 8-iso-prostaglandin-F2α stimulates chloride transport in thick ascending limbs: role of cAMP and protein kinase A.

    PubMed

    Cabral, Pablo D; Silva, Guillermo B; Baigorria, Sandra T; Juncos, Luis A; Juncos, Luis I; García, Néstor H

    2010-12-01

    Salt reabsorption by the loop of Henle controls NaCl handling and blood pressure regulation. Increased oxidative stress stimulates NaCl transport in one specific segment of the loop of Henle called the thick ascending limb (TAL). The isoprostane 8-iso-prostaglandin-F2α (8-iso-PGF2α) is one of the most abundant nonenzymatic lipid oxidation products and has been implicated in the development of hypertension. However, it is not known whether 8-iso-PGF2α regulates transport or the mechanisms involved. Because protein kinase A (PKA) stimulates NaCl transport in several nephron segments, we hypothesized that 8-iso-PGF2α increases NaCl transport in the cortical TAL (cTAL) via a PKA-dependent mechanism. We examined the effect of luminal 8-iso-PGF2α on NaCl transport by measuring chloride absorption (J(Cl)) in isolated microperfused cTALs. Adding 8-iso-PGF2α to the lumen increased J(Cl) by 54% (from 288.7 ± 30.6 to 446.5 ± 44.3 pmol·min(-1)·mm(-1); P < 0.01), while adding it to the bath enhanced J(Cl) by 35% (from 236.3 ± 35.3 to 319.2 ± 39.8 pmol·min(-1)·mm(-1); P < 0.05). This stimulation was blocked by Na-K-2Cl cotransporter inhibition. Next, we tested the role of cAMP. Basal cAMP in the cTAL was 18.6 ± 1.6 fmol·min(-1)·mm(-1), and 8-iso-PGF2α raised it to 35.1 ± 1.4 fmol·min(-1)·mm(-1), an increase of 94% (P < 0.01). Because cAMP stimulates PKA, we measured J(Cl) using the PKA-selective inhibitor H89. In the presence of H89 (10 μM), 8-iso-PGF2α failed to increase transport regardless of whether it was added to the lumen (216.1 ± 16.7 vs. 209.7 ± 23.8 pmol·min(-1)·mm(-1); NS) or the bath (150.4 ± 32.9 vs. 127.1 ± 28.6 pmol·min(-1)·mm(-1); NS). We concluded that 8-iso-PGF2α stimulates cAMP and increases Cl transport in cTALs via a PKA-dependent mechanism.

  10. Activation of K+ channels in renal medullary vesicles by cAMP-dependent protein kinase

    SciTech Connect

    Reeves, W.B.; McDonald, G.A.; Mehta, P.; Andreoli, T.E. )

    1989-07-01

    ADH, acting through cAMP, increases the potassium conductance of apical membranes of mouse medullary thick ascending limbs of Henle. The present studies tested whether exposure of renal medullary apical membranes in vitro to the catalytic subunit of cAMP-dependent protein kinase resulted in an increase in potassium conductance. Apical membrane vesicles prepared from rabbit outer renal medulla demonstrated bumetanide- and chloride-sensitive {sup 22}Na+ uptake and barium-sensitive, voltage-dependent {sup 86}Rb+ influx. When vesicles were loaded with purified catalytic subunit of cAMP-dependent protein kinase (150 mU/ml), 1 mM ATP, and 50 mM KCl, the barium-sensitive {sup 86}Rb+ influx increased from 361 {plus minus} 138 to 528 {plus minus} 120 pM/mg prot.30 sec (P less than 0.01). This increase was inhibited completely when heat-stable protein kinase inhibitor (1 microgram/ml) was also present in the vesicle solutions. The stimulation of {sup 86}Rb+ uptake by protein kinase required ATP rather than ADP. It also required opening of the vesicles by hypotonic shock, presumably to allow the kinase free access to the cytoplasmic face of the membranes. We conclude that cAMP-dependent protein kinase-mediated phosphorylation of apical membranes from the renal medulla increases the potassium conductance of these membranes. This mechanism may account for the ADH-mediated increase in potassium conductance in the mouse mTALH.

  11. Basolateral membrane H/OH/HCO3 transport in the rat cortical thick ascending limb. Evidence for an electrogenic Na/HCO3 cotransporter in parallel with a Na/H antiporter.

    PubMed Central

    Krapf, R

    1988-01-01

    Mechanisms involved in basolateral H/OH/HCO3 transport in the in vitro microperfused rat cortical thick ascending limb were examined by the microfluorometric determination of cell pH using (2',7')-bis-(carboxyethyl)-(5,6)-carboxyfluorescein. The mean cell pH in this segment perfused with 147 mM sodium and 25 mM HCO3 at pH 7.4 was 7.13 +/- 0.02 (n = 30). Lowering bath HCO3 from 25 to 5 mM (constant PCO2 of 40 mmHg) acidified the cells by 0.31 +/- 0.02 pH units at a rate of 0.56 +/- 0.08 pH units/min. Removal of bath sodium acidified the cells by 0.28 +/- 0.03 pH units at a rate of 0.33 +/- 0.04 pH units/min. The cell acidification was stilbene inhibitable and independent of chloride. There was no effect of bath sodium removal on cell pH in the absence of CO2/HCO3. Depolarization of the basolateral membrane (step increase in bath potassium) independent of the presence of chloride. Cell acidification induced by bath sodium removal persisted when the basolateral membrane was voltage clamped by high potassium/valinomycin. Although these results are consistent with a Na/(HCO3)n greater than 1 cotransporter, a Na/H antiporter was also suggested: 1 mM bath amiloride inhibited the cell pH defense against an acid load (rapid ammonia washout), both in the presence and absence of CO2/HCO3, and inhibited the cell acidification induced by bath sodium reduction from 50 to 0 mM. In conclusion, an electrogenic Na/(HCO3)n greater than 1 cotransporter in parallel with a Na/H antiporter exist on the basolateral membrane of the rat cortical thick ascending limb. PMID:2839547

  12. Conus medullaris stroke

    PubMed Central

    Alanazy, Mohammed H.

    2016-01-01

    Absent F wave in the stage of spinal shock has been described in cases of traumatic spinal cord injury. The role of F wave in predicting prognosis after conus medullaris infarct has not been described. We describe herein a middle aged-man with a conus medullaris infarct. Both tibial and peroneal F waves were absent on day 4. The left tibial F wave reappeared in the following study on day 18. All F waves reappeared on day 56 at which time the patient was still wheelchair bound. He regained walking on day 105. We hypothesize that reappearance of initially absent F waves post conus medullaris infarct is a good prognostic sign for the return of ambulation. The applicability of this observation requires further research. We also discuss clinical and diagnostic caveats in this case. PMID:27356660

  13. Role of renal medullary oxidative and/or carbonyl stress in salt-sensitive hypertension and diabetes.

    PubMed

    Mori, Takefumi; Ogawa, Susumu; Cowely, Allen W; Ito, Sadayoshi

    2012-01-01

    1. Salt-sensitive hypertension is commonly associated with diabetes, obesity and chronic kidney disease. The present review focuses on renal mechanisms involved in the development of this type of hypertension. 2. The renal medullary circulation plays an important role in the development of salt-sensitive hypertension. In vivo animal studies have demonstrated that the balance between nitric oxide (NO) and reactive oxygen species (ROS) in the renal medulla is an important element of salt-sensitive hypertension. The medullary thick ascending limb (mTAL) in the outer medulla is an important source of NO and ROS production and we have explored the mechanisms that stimulate their production, as well as the effects of NO superoxide and hydrogen peroxide on mTAL tubular sodium reabsorption and the regulation of medullary blood flow. 3. Angiotensin II-stimulated NO produced in the mTAL is able to diffuse from the renal mTAL to the surrounding vasa recta capillaries, providing a mechanism by which to increase medullary blood flow and counteract the direct vasoconstrictor effects of angiotensin II. Enhanced oxidative stress attenuates NO diffusion in this region. 4. Carbonyl stress, like oxidative stress, can also play an important role in the pathogenesis of chronic kidney disease, such as insulin resistance, salt-sensitive hypertension and renal vascular complications. 5. Despite the large number of studies undertaken in this area, there is as yet no drug available that directly targets renal ROS. Oxidative and/or carbonyl stress may be the next target of drug discovery to protect against salt-sensitive hypertension and associated end-organ damage.

  14. Missense Mutation of POU Domain Class 3 Transcription Factor 3 in Pou3f3L423P Mice Causes Reduced Nephron Number and Impaired Development of the Thick Ascending Limb of the Loop of Henle.

    PubMed

    Rieger, Alexandra; Kemter, Elisabeth; Kumar, Sudhir; Popper, Bastian; Aigner, Bernhard; Wolf, Eckhard; Wanke, Rüdiger; Blutke, Andreas

    2016-01-01

    During nephrogenesis, POU domain class 3 transcription factor 3 (POU3F3 aka BRN1) is critically involved in development of distinct nephron segments, including the thick ascending limb of the loop of Henle (TAL). Deficiency of POU3F3 in knock-out mice leads to underdevelopment of the TAL, lack of differentiation of TAL cells, and perinatal death due to renal failure. Pou3f3L423P mutant mice, which were established in the Munich ENU Mouse Mutagenesis Project, carry a recessive point mutation in the homeobox domain of POU3F3. Homozygous Pou3f3L423P mutants are viable and fertile. The present study used functional, as well as qualitative and quantitative morphological analyses to characterize the renal phenotype of juvenile (12 days) and aged (60 weeks) homo- and heterozygous Pou3f3L423P mutant mice and age-matched wild-type controls. In both age groups, homozygous mutants vs. control mice displayed significantly smaller kidney volumes, decreased nephron numbers and mean glomerular volumes, smaller TAL volumes, as well as lower volume densities of the TAL in the kidney. No histological or ultrastructural lesions of TAL cells or glomerular cells were observed in homozygous mutant mice. Aged homozygous mutants displayed increased serum urea concentrations and reduced specific urine gravity, but no evidence of glomerular dysfunction. These results confirm the role of POU3F3 in development and function of the TAL and provide new evidence for its involvement in regulation of the nephron number in the kidney. Therefore, Pou3f3L423P mutant mice represent a valuable research model for further analyses of POU3F3 functions, or for nephrological studies examining the role of congenital low nephron numbers.

  15. Renal Medullary Interstitial Cells

    NASA Astrophysics Data System (ADS)

    Rao, Reena; Hao, Chuan-Ming; Breyer, Matthew D.

    2007-04-01

    Renal medullary interstitial cells (RMICs) are specialized fibroblast-like cells that reside in the renal medulla among the vasa recta, the thin limbs of Henle's loop, and medullary collecting ducts. These cells are characterized by abundant lipid droplets in the cytoplasm. The lipid droplets are composed of triglycerides, cholesterol esters and free long-chain fatty acids, including arachidonic acid. RMICs are also a major site of cyclooxygenase2 (COX-2) expression, and thus a major site of COX-2 derived prostanoid biosynthesis. RMICs are also a potential target of hormones such as angiotensin II and endothelin. The RMIC COX-2 expression and the abundance of lipid droplets change with salt and water intake. These properties of RMICs are consistent with an important role of these cells in modulating physiologic and pathologic processes of the kidney.

  16. Medullary thyroid carcinoma.

    PubMed

    Leboulleux, Sophie; Baudin, Eric; Travagli, Jean-Paul; Schlumberger, Martin

    2004-09-01

    Medullary thyroid carcinoma (MTC) arises from parafollicular or C cells that produce calcitonin (CT), and accounts for 5-10% of all thyroid cancers. MTC is hereditary in about 25% of cases. The discovery of a MTC in a patient has several implications: disease extent should be evaluated, phaeochromocytoma and hyperparathyroidism should be screened for and whether the MTC is sporadic or hereditary should be determined by a direct analysis of the RET proto-oncogene. In this review, pathological characteristics, tumour markers and genetic abnormalities in MTC are discussed. The diagnostic and therapeutic modalities applied to patients with clinical MTC and those identified with preclinical disease through familial screening are also described. Progresses concerning genetics, initial treatment, follow-up, screening and treatment of pheochromocytoma have permitted an improvement in the long-term outcome. However, there is no effective treatment for distant metastases, and new therapeutic modalities are urgently needed.

  17. A 9 years boy with MEN-2B variant of medullary thyroid carcinoma.

    PubMed

    Sattar, M A; Hadi, H I; Ekramuddoula, F M; Hasanuzzaman, S M

    2013-04-01

    To highlight a rare disease like multiple endocrine neoplasia (MEN)-2B variant of medullary thyroid carcinoma and to optimize the management option in such cases, we present a nine year old boy with thyroid swelling, cervical lymphadenopathy and thick lips. His calcitonin level was raised. Investigation's results of the boy were as following fine needle aspiration cytology (FNAC) was medullary carcinoma of thyroid, preoperative calcitonin was >2000pg/ml, post operative histopathological report was medullary carcinoma. Total thyroidectomy with aggressive initial neck surgery may reduce the recurrence and increase better prognosis and survival rate. Calcitonin is used as diagnostic and follow-up marker.

  18. Organization of ascending spinal projections in Caiman crocodilus.

    PubMed

    Ebbesson, S O; Goodman, D C

    1981-01-01

    Ascending spinal projections in the caiman (Caiman crocodilus) were demonstrated with Nauta and Fink-Heimer methods following hemisections of the third spinal segment in a series of twelve animals. These results were compared with earlier data in the literature obtained from a turtle, a snake, and a lizard using the same experimental and histological procedures. The results show remarkable similarities considering that each species represents a different reptilian order with different evolutionary history and habitat. However, the caiman displays several important peculiarities. Although the dorsal funiculus of the caiman contains the largest number of ascending spinal projections of the four species examined, this funiculus has not differentiated into cuneate and gracile fasciculi as is the case in the tegu lizard. The ventro-lateral ascending spinal projections follow a fundamentally similar general morphologic pattern in the four species with only minor variations. The anatomical arrangement in the caiman and tegu lizard appears most similar in the high cervical and the medullary regions; however, this is not the case in midbrain and thalamic regions where considerably more extensive projections are seen in the caiman. In the caiman an extensive spinal connection to the ventro-lateral nucleus of the dorsal thalamus is present; this connection is reminiscent of the mammalian spinal projection to the ventro-basal complex. The caiman has in common with the other three reptilian species a small projection to another dorsal thalamic region that is apparently homologous to the mammalian intralaminar nuclei, which are the destination of the mammalian paleospinothalamic tract.

  19. [A sudden C3-C4 tetraplegia revealing an intracranial dural arteriovenous draining into the spinal medullary veins].

    PubMed

    Meaudre, E; Kaiser, E; Boret, H; Cantais, E; Artéaga, C; Palmier, B

    2005-10-01

    We report a case of intracranial dural arteriovenous (DAVF) draining into the spinal medullary veins. A 49-year-old woman presented a rapidly progressive ascending myelopathy resulting in a C3-C4 tetraplegia associated with acute respiratory failure at the twelfth hour. MRI revealed swelling of the cervical spinal cord, hyperintensity on T2 and enhancement of enlarged veins on MR angiography. A conventional angiography showed the DAVF with venous drainage into the spinal vein extending to the conus medullaris. After embolization, neurological recovery occurred during the first week, allowing tracheal extubation on day 2. Clinical, radiological and therapeutic aspects of this uncommon pathology are presented.

  20. The medullary pyramid index: an objective assessment of prominence in renal transplant rejection.

    PubMed

    Fried, A M; Woodring, J H; Loh, F K; Lucas, B A; Kryscio, R J

    1983-12-01

    Prominence of the medullary pyramids at sonography has been considered a sign of renal transplant rejection. A search of the literature reveals no previously published objective assessment of this phenomenon. Medullary pyramids of 67 normal kidneys, 53 nonrejecting transplanted kidneys, and 71 transplanted kidneys in rejection were measured. The area of the pyramid was related to the thickness of the overlying renal cortex by a "medullary pyramid index" (MPI): MPI (formula; see text) The median MPI was 4.17 for normal kidneys, 6.0 for nonrejecting transplanted kidneys, and 7.50 for transplanted kidneys in rejection. The results are significantly different (P = 0.0001) for all possible pairs. Overlap between rejection and nonrejection distributions is, however, considerable, rendering the discriminatory value of an individual observation quite low (0.69). Prominence of the medullary pyramids is therefore of very limited predictive value in the determination of transplant rejection in an individual patient.

  1. Medullary sponge kidney in childhood

    SciTech Connect

    Patriquin, H.B.; O'Regan, S.

    1985-08-01

    Medullary sponge kidney is reported in six children aged 2-18 years. One child was asymptomatic; the others had hematuria or a urine-concentrating defect. Renal function and size were otherwise normal, as was liver function. The diagnosis was made at excretory urography according to criteria established in adults. Sonography revealed hyperechogenic pyramids, at first at the periphery, later generalized. Computed tomography is very sensitive to the pyramidal nephrocalcinosis that complicates this disease and explains the frequent presenting symptom of hematuria in these children.

  2. Imaging of Renal Medullary Carcinoma

    PubMed Central

    Faiella, Eliodoro; Santucci, Domiziana; Mallio, Carlo Augusto; Nezzo, Marco; Quattrocchi, Carlo Cosimo; Beomonte Zobel, Bruno; Grasso, Rosario Francesco

    2017-01-01

    Renal medullary carcinoma (RMC) is a rare, highly aggressive tumor recognized as an independent pathological entity. African-descent adolescents and young adults with sickle cell hemoglobinopathy are the most affected groups. This rare subtype of renal cell carcinoma has its own morphogenetic and pathological characteristics. The major clinical manifestations include gross hematuria, abdominal or flank pain, and weight loss. The prognosis is very poor, with 95% of cases diagnosed at an advanced stage of the disease. In this review, we summarize the morphologic and dynamic characteristics of RMC under various imaging modalities such as ultrasound, computed tomography, and magnetic resonance. Differential diagnosis and management strategies are also discussed.

  3. Medullary sponge kidney associated with congenital hemihypertrophy.

    PubMed

    Indridason, O S; Thomas, L; Berkoben, M

    1996-08-01

    Medullary sponge kidney is a developmental disorder characterized by ectatic and cystic malformation of the collecting ducts and tubules. Clinical manifestations include urinary tract infections, renal stones, and hematuria. It can be associated with other developmental disorders. A case of medullary sponge kidney associated with congenital hemihypertrophy, complicated by nephrocalcinosis and nephrolithiasis, is reported here.

  4. Hashimoto's Thyroiditis and Medullary Carcinoma of Thyroid.

    PubMed

    Dasgupta, S; Chakrabarti, S; Mandal, P K; Das, S

    2014-01-01

    Hashimoto's thyroiditis (HT) has been found to be associated with lymphoma, papillary carcinoma and Hürthle cell neoplasms of thyroid. In contrast, there are only a few reports of co-existence of HT with medullary carcinoma of thyroid. An overall prevalence of medullary carcinoma of only 0.35% has been reported in HT patients. Such a rare combination is being presented here. A 33 year old female presented with history of goiter for one year. Fine needle aspiration cytology (FNAC) of the swelling revealed cytological features suggestive of medullary carcinoma of thyroid. Histopathological examination of total thyroidectomy specimen revealed Hashimoto's thyroiditis along with medullary carcinoma of thyroid. Although Hashimoto's thyroiditis can uncommonly co-exist with thyroid neoplasm, its association with medullary carcinoma is extremely rare and hence being presented.

  5. CO2-stimulated NaCl absorption in the mouse renal cortical thick ascending limb of Henle. Evidence for synchronous Na +/H+ and Cl-/HCO3- exchange in apical plasma membranes

    PubMed Central

    1982-01-01

    These experiments evaluated salt transport processes in isolated cortical thick limbs of Henle (cTALH) obtained from mouse kidney. When the external solutions consisted of Krebs-Ringer bicarbonate (KRB), pH 7.4, and a 95% O2-5% CO2 gas phase, the spontaneous transepithelial voltage (Ve, mV, lumen-to-bath) was approximately mV; the net rate of Cl- absorption (JnetCl) was approximately 3,600 pmols s-1 cm-2; the net rate of osmotic solute absorption Jnetosm was twice JnetCl; and the net rate of total CO2 transport (JnetCO2) was indistinguishable from zero. Thus, net Cl- absorption was accompanied by the net absorption of a monovalent cation, presumably Na+, and net HCO3- absorption was negligible. This salt transport process was stimulated by (CO2 + HCO3- ): omission of CO2 from the gas phase and HCO3- from external solutions reduced JnetCl, Jnetosm, and Ve by 50%. Furthermore, 10(-4) M luminal furosemide abolished JnetCl and Ve entirely. The lipophilic carbonic anhydrase inhibitor ethoxzolamide (10(-4) M, either luminal or peritubular) inhibited (CO2 + HCO3-)-stimulated JnetCl, Jnetosm, and Ve by approximately 50%; however, when the combination (CO2 + HCO3-) was absent, ethoxzolamide had no detectable effect on salt transport. Ve was reduced or abolished entirely by omission of either Na+ or Cl- from external solutions, by peritubular K+ removal, by 10(-3) M peritubular ouabain, and by 10(-4) M luminal SITS. However, Ve was unaffected by 10(-3) M peritubular SITS, or by the hydrophilic carbonic anhydrase inhibitor acetazolamide (2.2 x 10(-4) M, lumen plus bath). We interpret these data to indicate that (CO2 + HCO3-)-stimulated NaCl absorption in the cTALH involved two synchronous apical membrane antiport processes: one exchanging luminal Na+ for cellular H+; and the other exchanging luminal Cl- for cellular HCO3- or OH-, operating in parallel with a (CO2+ HCO3-)-independent apical membrane NaCl cotransport mechanism. PMID:6816900

  6. Medullary cystic disease: a family study.

    PubMed

    Chen, H C; Chang, J M; Tsai, J H; Lai, Y H

    1998-03-01

    Medullary cystic disease of the kidney is characterized by progressive tubulointerstitial disease with medullary cyst formation and secondary glomerular sclerosis. We treated a patient with chronic renal failure and investigated the family history of renal disease. The patient, an 18-year-old woman, was admitted due to poor appetite and fatigue for several months. Findings on physical examination were normal except for a pale conjunctiva. Urinalysis revealed only mild proteinuria with clear sediment. The hemogram showed normocytic normochromic anemia with hemoglobin 86 g/L. The patient was azotemic and her creatinine clearance rate was 10.7 mL/min. Renal sonography showed contraction of both kidneys with a marked increase in cortical echogenicity. One small cyst was found in the medullary area. Computed tomography (CT) and magnetic resonance imaging revealed several medullary cysts. Percutaneous renal biopsy showed focal and periglomerular sclerosis, marked tubular atrophy, and interstitial fibrosis. Ten of her family members were examined for renal function, and by sonography and CT. Five had medullary cysts, and three of the five showed abnormal renal function. Medullary cystic disease should be considered in the differential diagnosis of patients with renal disease and a positive family history.

  7. Heat transfer of ascending cryomagma on Europa

    NASA Astrophysics Data System (ADS)

    Quick, Lynnae C.; Marsh, Bruce D.

    2016-06-01

    Jupiter's moon Europa has a relatively young surface (60-90 Myr on average), which may be due in part to cryovolcanic processes. Current models for both effusive and explosive cryovolcanism on Europa may be expanded and enhanced by linking the potential for cryovolcanism at the surface to subsurface cryomagmatism. The success of cryomagma transport through Europa's crust depends critically on the rate of ascent relative to the rate of solidification. The final transport distance of cryomagma is thus governed by initial melt volume, ascent rate, overall ascent distance, transport mechanism (i.e., diapirism, diking, or ascent in cylindrical conduits), and melt temperature and composition. The last two factors are especially critical in determining the budget of expendable energy before complete solidification. Here we use these factors as constraints to explore conditions under which cryomagma may arrive at Europa's surface to facilitate cryovolcanism. We find that 1-5 km radius warm ice diapirs ascending from the base of a 10 km thick stagnant lid can reach the shallow subsurface in a partially molten state. Cryomagma transport may be further facilitated if diapirs travel along pre-heated ascent paths. Under certain conditions, cryolava transported from 10 km depths in tabular dikes or pipe-like conduits may reach the surface at temperatures exceeding 250 K. Ascent rates for these geometries may be high enough that isothermal transport is approached. Cryomagmas containing significant amounts of low eutectic impurities can also be delivered to Europa's surface by propagating dikes or pipe-like conduits.

  8. Adrenal cortical and medullary imaging.

    PubMed

    Freitas, J E

    1995-07-01

    Adrenal disease can be manifested by endocrine dysfunction or anatomic abnormalities detected by cross-sectional imaging modalities. With the advent of newer and more reliable in vitro assays and a better understanding of the spectrum of adrenal pathology, the physician can now adopt a more accurate and cost-effective approach to the diagnosis of adrenal disease. Both functional and anatomic imaging modalities can play an important role in the evaluation of the incidental adrenal mass, the early detection of adrenal metastases, differentiation of the various causes of Cushings's syndrome, selection of patients for potentially curative surgery in primary aldosteronism and adrenal hyperandrogenism, and localization of pheochromocytomas and neuroblastomas. The usefulness of the adrenal cortical radiopharmaceutical, 131I-6-beta-iodomethylnorcholesterol (NP-59), and the adrenal medullary radiopharmaceuticals, 131I and 123I-metaiodobenzylguanidine (MIBG), is detailed for these various clinical settings and the role of NP-59 and MIBG is contrasted to that of the cross-sectional modalities, computed tomography and magnetic resonance imaging (MRI). Incidental adrenal masses are common, but malignancies are few. Imaging studies select those patients who require a further evaluation by biopsy examination or adrenalectomy. In the hyperfunctioning endocrine states, such as Cushing's syndrome, primary aldosteronism, adrenal androgenism, and pheochromocytoma, correlation of biochemical findings with both functional and anatomic imaging is necessary to avoid inappropriate and ineffective surgical intervention, yet not miss an opportunity for curative resection. Lastly, MIBG and MRI are complementary in the detection and staging of neuroblastoma.

  9. Angiotensin II Induces Region-Specific Medial Disruption during Evolution of Ascending Aortic Aneurysms

    PubMed Central

    Rateri, Debra L.; Davis, Frank M.; Balakrishnan, Anju; Howatt, Deborah A.; Moorleghen, Jessica J.; O’Connor, William N.; Charnigo, Richard; Cassis, Lisa A.; Daugherty, Alan

    2015-01-01

    Angiotensin II (Ang II) promotes development of ascending aortic aneurysms (AAs), but progression of this pathology is undefined. We evaluated factors potentially involved in progression, and determined the temporal sequence of tissue changes during development of Ang II–induced ascending AAs. Ang II infusion into C57BL/6J mice promoted rapid expansion of the ascending aorta, with significant increases within 5 days, as determined by both in vivo ultrasonography and ex vivo sequential acquisition of tissues. Rates of expansion were not significantly different in LDL receptor–null mice fed a saturated fat-enriched diet, demonstrating a lack of effect of hypercholesterolemia. Augmenting systolic blood pressure with norepinephrine infusion had no significant effect on ascending aortic expansion. Pathological changes observed within 5 days of Ang II infusion included increased medial thickness and intramural hemorrhage characterized by erythrocyte extravasation in outer lamellar layers of the media. Intramedial hemorrhage was not observed after prolonged Ang II infusion, although partial medial disruption was present. Elastin fragmentation and transmural medial breaks of the ascending aorta were observed with continued Ang II infusion, which were restricted to anterior aspects. CD45+ cells accumulated in adventitia but were minimal in media. Similar pathology was observed in tissues obtained from patients with ascending AAs. In conclusion, Ang II promotes ascending AAs through region-specific changes that are independent of hypercholesterolemia or systolic blood pressure. PMID:25038458

  10. Pharmacologic inhibition of the renal outer medullary potassium channel causes diuresis and natriuresis in the absence of kaliuresis.

    PubMed

    Garcia, Maria L; Priest, Birgit T; Alonso-Galicia, Magdalena; Zhou, Xiaoyan; Felix, John P; Brochu, Richard M; Bailey, Timothy; Thomas-Fowlkes, Brande; Liu, Jessica; Swensen, Andrew; Pai, Lee-Yuh; Xiao, Jianying; Hernandez, Melba; Hoagland, Kimberly; Owens, Karen; Tang, Haifeng; de Jesus, Reynalda K; Roy, Sophie; Kaczorowski, Gregory J; Pasternak, Alexander

    2014-01-01

    The renal outer medullary potassium (ROMK) channel, which is located at the apical membrane of epithelial cells lining the thick ascending loop of Henle and cortical collecting duct, plays an important role in kidney physiology by regulating salt reabsorption. Loss-of-function mutations in the human ROMK channel are associated with antenatal type II Bartter's syndrome, an autosomal recessive life-threatening salt-wasting disorder with mild hypokalemia. Similar observations have been reported from studies with ROMK knockout mice and rats. It is noteworthy that heterozygous carriers of Kir1.1 mutations associated with antenatal Bartter's syndrome have reduced blood pressure and a decreased risk of developing hypertension by age 60. Although selective ROMK inhibitors would be expected to represent a new class of diuretics, this hypothesis has not been pharmacologically tested. Compound A [5-(2-(4-(2-(4-(1H-tetrazol-1-yl)phenyl)acetyl)piperazin-1-yl)ethyl)isobenzofuran-1(3H)-one)], a potent ROMK inhibitor with appropriate selectivity and characteristics for in vivo testing, has been identified. Compound A accesses the channel through the cytoplasmic side and binds to residues lining the pore within the transmembrane region below the selectivity filter. In normotensive rats and dogs, short-term oral administration of compound A caused concentration-dependent diuresis and natriuresis that were comparable to hydrochlorothiazide. Unlike hydrochlorothiazide, however, compound A did not cause any significant urinary potassium losses or changes in plasma electrolyte levels. These data indicate that pharmacologic inhibition of ROMK has the potential for affording diuretic/natriuretic efficacy similar to that of clinically used diuretics but without the dose-limiting hypokalemia associated with the use of loop and thiazide-like diuretics.

  11. Bilateral Thyroid and Ultimobranchial Medullary Carcinoma.

    PubMed

    Patey, Martine; Flament, Jean Bernard; Caron, Jean; Delisle, Marie Joelle; Delemer, Brigitte; Pluot, Michel

    1996-01-01

    The ultimobranchial bodies in human embryos develop from the fourth and fifth branchial pouch complexes along with thymic and parathyroid tissue. They become incorporated within the lateral thyroid lobes and are believed to be involved in the development of C-cells. We report a case of an unusual bilateral thyroid and neck prelaryngeal medullary carcinoma in a 23-year-old male patient who belongs to a multiple endocrine neoplasia type 2a (MEN type 2a) family with thyroid tumors and pheochromocytomas. The medullary carcinoma was located in an abnormal cystic structure that seems to be a remnant of the ultimobranchial body (UBB) in the neck. Within the contralateral thyroid lobe, the medullary carcinoma was associated with C-cell hyperplasia.

  12. Schwannosis induced medullary compression in VACTERL syndrome.

    PubMed

    Treacy, A; Redmond, M; Lynch, B; Ryan, S; Farrell, M; Devaney, D

    2009-01-01

    A 7-year-old boy with a history of VACTERL syndrome was found collapsed in bed. MRI had shown basilar invagination of the skull base and narrowing of the foramen magnum. Angulation, swelling and abnormal high signal at the cervicomedullary junction were felt to be secondary to compression of the medulla. Neuropathologic examination showed bilateral replacement of the medullary tegmentum by an irregularly circumscribed cellular lesion which was composed of elongated GFAP/S 100-positive cells with spindled nuclei and minimal atypia. The pathologic findings were interpreted as intramedullary schwannosis with mass effect. Schwannosis, is observed in traumatized spinal cords where its presence may represent attempted, albeit aberrant, repair by inwardly migrating Schwann cells ofperipheral origin. In our view the compressive effect of the basilar invagination on this boy's medulla was of sufficient magnitude to have caused tumoral medullary schwannosis with resultant intermittent respiratory compromise leading to reflex anoxic seizures.

  13. Medullary carcinoma in a lingual thyroid.

    PubMed

    Yaday, S; Singh, I; Singh, J; Aggarwal, N

    2008-03-01

    Total ectopia of thyroid is a rare phenomenon and malignant change in an ectopic thyroid is even rarer. We report a case of medullary carcinoma in a total ectopic lingual thyroid occurring in a 45-year-old woman who presented with dysphagia, plummy voice and a round sessile mass at the base of the tongue. The mass was extirpated using Trotter's midline approach. Upon examination, it was found to be medullary carcinoma in an ectopic thyroid. Permanent substitution therapy with thyroxine secured the euthyroid status of the patient. The embrylogical basis and a review of literature regarding carcinomatous change in an ectopic thyroid are also discussed. There is a need to investigate for an ectopic thyroid, or even total ectopia, in the case of any smooth mass found at the base of the tongue.

  14. Bradshaw lecture, 1976. Thyroid medullary carcinoma.

    PubMed Central

    Taylor, S.

    1977-01-01

    The main characteristics of medullary carcinoma of the thyroid are its non-follicular histological appearance, resulting from its origin from the parafollicular C cells, its secretion of calcitonin, providing a relatively simple diagnostic test, and its equal sex incidence, in contrast to all other diseases of the thyroid. Sporadic cases are seen and it occurs in familial groups, with autosomal dominant inheritance, when it is associated with phaeochromocytoma and parathyroid hyperplasia to form the second type of multiple endocrine adenomatosis (MEA2). These last features make it necessary in every case of medullary carcinoma of the thyroid to examine other members of the family and to investigate the possibility of concomitant adrenal and parathyroid disease. The priorities of treatment when these are present and the indications for total thyroidectomy are discussed. Images Fig. 1 PMID:20027

  15. Medial medullary infarction: abnormal ocular motor findings.

    PubMed

    Kim, J Soo; Choi, K-D; Oh, S-Y; Park, S-H; Han, M-K; Yoon, B-W; Roh, J-K

    2005-10-25

    In 20 consecutive patients with isolated medial medullary infarction, abnormal ocular motor findings included nystagmus (n = 8), ocular contrapulsion (n = 5), and contralesional ocular tilt reaction (n = 2). The nystagmus was ipsilesional (n = 4), gaze-evoked (n = 5), upbeating (n = 4), and hemiseesaw (n = 1). The ocular motor abnormalities may be explained by involvements of the nucleus prepositus hypoglossi, medial longitudinal fasciculus or efferent fibers from the vestibular nuclei, climbing fibers, and cells of the paramedian tracts.

  16. Normal conus medullaris: CT criteria for recognition

    SciTech Connect

    Grogan, J.P.; Daniels, D.L.; Williams, I.L.; Rauschning, W.; Haughton, V.M.

    1984-06-01

    The normal CT configuration and dimension of the conus medullaris and adjacent spinal cord were determined in 30 patients who had no clinical evidence of conus compression. CT studies were also correlated with anatomic sections in cadavers. The normal conus on CT has a distinctive oval configuration, an arterior sulcus, and a posterior promontory. The anteroposterior diameter ranged from 5 to 8 mm; the transverse diameter from 8 to 11 mm. Intramedullary processes altered both the dimensions and configuration of the conus.

  17. Transport of sodium and urea in outer medullary descending vasa recta.

    PubMed Central

    Pallone, T L; Work, J; Myers, R L; Jamison, R L

    1994-01-01

    We dissected and perfused outer medullary vasa recta (OMVR) from vascular bundles in the rat. Permeabilities of sodium (PNa) and urea (Pu) were simultaneously determined from the lumen-to-bath efflux of 22Na and [14C]urea. PNa and Pu were also measured by in vivo microperfusion of descending (DVR) and ascending vasa recta (AVR) at the papillary tip of Munich-Wistar rats. In some OMVR PNa was indistinguishable from zero. The mean +/- SE of PNa (x 10(-5), cm/s) in OMVR was 76 +/- 9. Pu in OMVR was always very high (x 10(-5), cm/s), 360 +/- 14. There was no correlation between OMVR PNa and Pu. Inner medullary AVR and DVR had PNa of 115 +/- 10 and 75 +/- 10, respectively, and Pu of 121 +/- 10 and 76 +/- 11, respectively. PNa and Pu in papillary vasa recta were always nearly identical and highly correlated. Transport of [14C] urea in OMVR was reversibly inhibited by addition of unlabeled urea or phloretin to the bath and lumen, providing evidence for carrier-mediated transport. These data suggest that sodium and urea might traverse the wall of inner medullary vasa recta by a paracellular pathway while urea also crosses by a transcellular route in OMVR. Electron microscopic examination of seven in vitro perfused OMVR revealed no fenestrations and exposure of these vessels to 10 microM calcium ionophore A23187 or 1 nM angiotensin II resulted in reversible contraction, suggesting that in vitro perfused OMVR are DVR only. Images PMID:8282790

  18. Quantitation of the prominent medullary pyramid: a reappraisal.

    PubMed

    Paling, M R; Black, W C

    1986-06-01

    We propose a revised objective measurement of the size of the renal medullary pyramid in the assessment of the prominent renal pyramid: the medullary-renal ratio (MRR). (Formula: see text). This is a more accurate assessment of the size of the renal pyramid relative to the size of the kidney than the previously proposed medullary pyramid index, which fails to take into account the varying morphology of otherwise normal kidneys.

  19. Medullary trichomalacia in 6 German shepherd dogs.

    PubMed

    Tieghi, Chiara; Miller, William H; Scott, Danny W; Pasquinelli, Gianandrea

    2003-02-01

    Medullary trichomalacia is the name proposed for a hair shaft abnormality that was recognized in 6 German shepherd dogs. Affected dogs had multifocal areas of broken hairs, especially on the dorsolateral trunk. Microscopic examination of hair shafts revealed focal areas of loss of architecture, swelling, and apparent softening of the medulla, followed by longitudinal (length-wise) splitting and breakage of the hair shaft. No cause could be found. Affected dogs were otherwise healthy, and apparent spontaneous recovery was the usual outcome. Relapses may occur.

  20. Intramedullary bronchogenic cyst of the conus medullaris.

    PubMed

    Yilmaz, Cem; Gulsen, Salih; Sonmez, Erkin; Ozger, Ozkan; Unlukaplan, Muge; Caner, Hakan

    2009-10-01

    Spinal bronchogenic cysts are rare congenital lesions. The authors describe their experience in the treatment of a 17-year-old boy who presented with back pain and paresthesia in both lower extremities. Lumbar MR imaging revealed the presence of an intramedullary cystic lesion at the conus medullaris and histopathological analysis revealed a bronchogenic cyst. To the best of the authors' knowledge, this is the first report of an intramedullary spinal bronchogenic cyst arising at the conus; all previously reported spinal bronchogenic cysts were either intradural extramedullary or not located at the conus.

  1. Central pontine myelinolysis and medullary myelinolysis.

    PubMed

    Bhagavan, B S; Wagner, J A; Juanteguy, J

    1976-05-01

    Central pontine myelinolysis (CPM) is a rare, acute, and uniformly fatal demyelinative process that involves the pons almost exclusively. Three cases diagnosed at autopsy illustrate the characteristic clinical course and pathologic features of CPM. A unique extrapontine location of a similar process is noted in the medulla of a 6-year-old girl. The term "medullary myelinolysis" is a descriptive designation for demyelination that occurs predominantly in this area. The clinical and pathologic features of CPM are reviewed in detail, together with a brief review of theories of metabolic, nutritional, vascular, and endogenous and exogenous toxic factors that act either singly or in concert in the cause and pathogenesis of CPM.

  2. [A case of dural arteriovenous fistula at the craniocervical junction, which spinal MRI findings reveals increased intensity signal in Th3-medullary cone].

    PubMed

    Ueda, Masamichi; Ueda, Miki; Takeuchi, Yuko; Ochiai, Jun; Mabuchi, Chiyuki; Hattori, Shinnosuke

    2016-01-01

    A 60-year-old woman had transient weakness of the legs and urinary retention for six weeks. She presented with a gait disorder and was admitted to the hospital. She showed symptoms of paraplegia, tingling in the lower extremities, dysuria. She underwent an MRI, and T2-weighted images showed an enlargement of the thoracolumbar spinal cord and high intensity signal from Th3 to the medullary cone, and a contrast-enhanced T1-weighted image showed abnormal vessels anterior to the spine cord. Cervical and spinal angiography documented a dural arteriovenous fistula at the craniocervical junction that was fed by the right vertebral artery and the right ascending pharyngeal arteries and drained into the perimedullary veins. Surgical therapy improved her symptoms and MRI images. Craniocervical junction DAVF with thoracic-medullary cones lesion is rare.

  3. The pathology of preclinical medullary thyroid carcinoma.

    PubMed

    Ashworth, Michael

    2004-01-01

    Medullary carcinoma of the thyroid (MTC) occurs sporadically, or in familial forms in familial medullary thyroid carcinoma and multiple endocrine neoplasia types 2A and 2B. In the familial forms it is associated with well-characterized, germline mutations in the RET protooncogene. The mutation sites differ in MEN2A and MEN2B, and MTC develops at an earlier age and is more aggressive in MEN2B. Screening of relatives of affected individuals for such mutations can identify those at risk of developing MTC and total thyroidectomy can be carried out in the first decade of life before the development of clinical disease. Analysis of such removed thyroid glands shows abnormalities of the parafollicular C-cells in almost all cases. The abnormalities range from C-cell hyperplasia, either diffuse or nodular, to microcarcinoma and occasionally frank MTC. The abnormalities are bilateral and affect the upper two thirds of the thyroid lobes. Microcarcinomas may be visible with the naked eye, but often they are identified only on microscopy. Histopathological examination of the entire gland is essential.

  4. C-cell hyperplasia and medullary thyroid microcarcinoma.

    PubMed

    Albores-Saavedra, J A; Krueger, J E

    2001-01-01

    Since the discovery of the thyroid C-cell, considerable progress has been made regarding its origin, function, and pathology. In this article an attempt is made to summarize and update our knowledge about physiologic or reactive C-cell hyperplasia, neoplastic C-cell hyperplasia (medullary carcinoma in situ), and medullary microcarcinoma. Seldom recognized preoperatively, physiologic C-cell hyperplasia is associated with inflammatory, metabolic, and neoplastic thyroid disorders as well as with hypercalcemia. However, the pathogenesis is still unclear. Although physiologic C-cell hyperplasia may progress to medullary carcinoma, the full malignant potential is unknown. Problems related to the definition of physiologic C-cell hyperplasia are discussed. Immunohistochemistry and quantitative analysis are required for the diagnosis. By contrast, C-cell hyperplasia associated with MEN II syndromes or familial medullary carcinoma can be diagnosed preoperatively in asymptomatic children or adolescents by the detection of germline mutations of the RET protooncogene. Morphologic and genetic abnormalities support the idea that C-cells in the familial form of C-cell hyperplasia are neoplastic and can be recognized with conventional stains. Therefore, the number of C-cells is irrelevant for the diagnosis. Medullary microcarcinoma is a neoplasm that measures < 1 cm. The sporadic variant is usually an incidental microscopic finding, whereas the familial form can be diagnosed by genetic testing. Its morphologic features and biologic behavior differ from those of larger medullary carcinomas. The frequency of medullary microcarcinoma will probably increase with the use of genetic testing.

  5. [Dysphagia with lateral medullary infarction (Wallenberg's syndrome)].

    PubMed

    Oshima, Fumiko

    2011-11-01

    Dysphagia after lateral medullary infarction (LMI) is common. The dysphagia of LMI is dynamically characterized by a failure in triggering of the pharyngeal-phase swallowing movements, reduced output, and lack of coordination (swallowing pattern abnormality). Based on accurate evaluation, we can select suitable rehabilitative approaches for individual patients, including respiratory therapy, food modification, postural changes, and oral care. We focused on the absence of upper esophageal sphincter (UES) opening of the unaffected side of the medullae. The movement pattern was defined as failure of bolus passage through the intact side of the UES, occurring at least once during the videofluorographic evaluation of each individual. Three abnormal patterns of UES opening were classified. The passage pattern abnormality shows the failure of the stereotyped motor sequence. For severe cases, it is necessary to consider long-term treatment, including botulinum toxin injection or surgery to prevent aspiration and adequate nutritional management.

  6. Biomechanical Evaluation of Ascending Aortic Aneurysms

    PubMed Central

    Avanzini, Andrea; Battini, Davide

    2014-01-01

    The biomechanical properties of ascending aortic aneurysms were investigated only in the last decade in a limited number of studies. Indeed, in recent years, there has been a growing interest in this field in order to identify new predictive parameters of risk of dissection, which may have clinical relevance. The researches performed so far have been conducted according to the methods used in the study of abdominal aortic aneurysms. In most cases, uniaxial or biaxial tensile tests were used, while in a smaller number of studies other methods, such as opening angle, bulge inflation, and inflation-extension tests, were used. However, parameters and protocols of these tests are at present very heterogeneous in the studies reported in the literature, and, therefore, the results are not comparable and are sometimes conflicting. The purpose of this review then thence to provide a comprehensive analysis of the experimental methodology for determination of biomechanical properties in the specific field of aneurysms of the ascending aorta to allow for better comparison and understanding of the results. PMID:24991568

  7. Oral complications associated with idiopathic medullary aplasia: case report.

    PubMed

    Clercq, Marcel; Gagné-Tremblay, Mélanie

    2008-05-01

    This article describes a patient who experienced serious oral sequelae after severe oral hemorrhage associated with medullary aplasia. These complications required medical, surgical and prosthetic treatments necessitating dental expertise in the hospital setting.

  8. [Study of Medullary Thyroid Carcinoma from a proband].

    PubMed

    Morlán Herrador, Laura; de Arriba, Antonio; Miguel, Gloria; Ferrera, Marta; Labarta, José I

    2016-12-01

    Thyroid cancer is an uncommon type of cancer, accounting less than 1% of all cancers in adults, and 0.5-3% of all cancers in children. There are four different types: papillary carcinoma (80-90% of cases), follicular (5-10%), medullary (5%) and anaplastic cell (2-3%). Eighty per cent of cases of medullary thyroid cancer are sporadic, but 20% are associated with an inherited syndrome that is divided into three groups: multiple endocrine neoplasia type 1, multiple endocrine neoplasia type 2 and familial medullary thyroid carcinoma. The inherited forms are caused by a disruption in the RET oncogene, which is located in the long arm of chromosome 10. A hereditary case of medullary thyroid carcinoma is presented. It was detected because of a familial genetic study. The purpose of the paper is emphasize the importance of the early diagnosis and the intervention of multidisciplinary teams of experts.

  9. Gonococcal ascending aortitis with penetrating ulcers and intraluminal thrombus.

    PubMed

    Woo, J Susie; Rabkin, David G; Mokadam, Nahush A; Rendi, Mara H; Aldea, Gabriel S

    2011-03-01

    Neisseria gonorrhoeae is an uncommon pathogen causing bacterial aortitis. We describe a patient with a bicuspid aortic valve and known ascending aortic aneurysm who presented with fever and chest pain. Imaging demonstrated complex penetrating ulcers in the proximal ascending aorta. The patient underwent a modified Bentall procedure, resection of the ulcers, and ascending aortic reconstruction. Pathologic examination and culture of the aortic specimens revealed the infectious cause.

  10. Hypercalcitoninemia is not Pathognomonic of Medullary Thyroid Carcinoma

    PubMed Central

    Toledo, Sergio PA; Lourenço, Delmar M; Santos, Marcelo Augusto; Tavares, Marcos R; Toledo, Rodrigo A; de Menezes Correia-Deur, Joya Emilie

    2009-01-01

    Hypercalcitoninemia has frequently been reported as a marker for medullary thyroid carcinoma. Currently, calcitonin measurements are mostly useful in the evaluation of tumor size and progression, and as an index of biochemical improvement of medullary thyroid carcinomas. Although measurement of calcitonin is a highly sensitive method for the detection of medullary thyroid carcinoma, it presents a low specificity for this tumor. Several physiologic and pathologic conditions other than medullary thyroid carcinoma have been associated with increased levels of calcitonin. Several cases of thyroid nodules associated with increased values of calcitonin are not medullary thyroid carcinomas, but rather are related to other conditions, such as hypercalcemias, hypergastrinemias, neuroendocrine tumors, renal insufficiency, papillary and follicular thyroid carcinomas, and goiter. Furthermore, prolonged treatment with omeprazole (> 2–4 months), beta-blockers, glucocorticoids and potential secretagogues, have been associated with hypercalcitoninemia. An association between calcitonin levels and chronic auto-immune thyroiditis remains controversial. Patients with calcitonin levels >100 pg/mL have a high risk for medullary thyroid carcinoma (~90%–100%), whereas patients with values from 10 to 100 pg/mL (normal values: <8.5 pg/mL for men, < 5.0 pg/mL for women; immunochemiluminometric assay) have a <25% risk for medullary thyroid carcinoma. In multiple endocrine neoplasia type 2 (MEN2), RET mutation analysis is the gold-standard for the recommendation of total preventive thyroidectomy to relatives at risk of harboring a germline RET mutation (50%). False-positive calcitonin results within MEN2 families have led to incorrect indications of preventive total thyroidectomy to RET mutation negative relatives. In this review, we focus on the differential diagnosis of hypercalcitoninemia, underlining its importance for the avoidance of misdiagnosis of medullary thyroid carcinoma and

  11. Multiple medullary venous malformations decreasing cerebral blood flow: Case report

    SciTech Connect

    Tomura, N.; Inugami, A.; Uemura, K.; Hadeishi, H.; Yasui, N. )

    1991-02-01

    A rare case of multiple medullary venous malformations in the right cerebral hemisphere is reported. The literature review yielded only one case of multiple medullary venous malformations. Computed tomography scan showed multiple calcified lesions with linear contrast enhancement representing abnormal dilated vessels and mild atrophic change of the right cerebral hemisphere. Single-photon emission computed tomography using N-isopropyl-p-({sup 123}I) iodoamphetamine demonstrated decreased cerebral blood flow in the right cerebral hemisphere.

  12. A distinctive type of ascending prominence - 'Fountain'

    NASA Technical Reports Server (NTRS)

    Tandberg-Hanssen, E.; Hansen, R. T.; Riddle, A. C.

    1975-01-01

    Cinematographic observations of solar prominences made at Mauna Loa, Hawaii, during the past few years suggest that there is a well-defined subclass of ascending prominences characterized by closed-system transference of chromospheric material along an arch or loop (up one leg and down the other). While this occurs, the entire prominence envelope steadily rises upward and expands through the corona. These prominences are denoted as 'fountains'. Several examples are described. Fountains appear to be well contained by coronal magnetic fields. Their total kinetic energy is of the order of 10 to the 30th power erg, but dissipation is typically quite slow (over time periods of 100 min or so), so that the correlative disturbances (radio bursts, coronal transients, chromospheric brightenings) are generally not spectacular or nonexistent.

  13. Renal Medullary Carcinoma; A Rare Entity

    PubMed Central

    Çalışkan, Selahattin; Gökçe, Ali Murat; Gümrükçü, Gülistan; Önenerk, Mine

    2017-01-01

    Renal medullary carcinoma (RMC) is an uncommon aggressive neoplasm of the kidney. RMC is biologically aggressive with a very poor prognosis, and metastasis is seen in up to 95% of the patients at diagnosis or shortly thereafter. The common sites of metastasis are respectively lymph nodes, lungs, livers, and adrenal glands in order of frequency. The presence of poorly differentiated eosinophilic cells in a characteristic fibro-inflammatory stroma is seen in histological examination. The origin and pathogenesis of RMC are unclear. The radiographical and pathological findings suggest that RMC probably originates in the calyceal epithelium in or near the renal papillae, which could be the result of chronic ischemic damage in the renal papillae epithelium by sickled erythrocytes. Positivity of VEGF and HIF-1α supports the chronic hypoxia that may be caused in the pathogenesis of RMC. Other factors such as genetic or environmental factors are important. Although hemoglobinopathy is very common, RMC is very rare. An understanding of the molecular and genetic factors of this rare disease is important for its prevention and treatment. We herein describe an adult Turkish patient, who presented with hematuria. The diagnosis was RMC after pathological examination. PMID:28360450

  14. Medical Management of Metastatic Medullary Thyroid Cancer

    PubMed Central

    Maxwell, Jessica E.; Sherman, Scott K.; O’Dorisio, Thomas M.; Howe, James R.

    2014-01-01

    Medullary thyroid cancer (MTC) is an aggressive form of thyroid cancer, which occurs in both heritable and sporadic forms. Discovery that mutations in the RET protooncogene predispose to familial cases of this disease has allowed for presymptomatic identification of gene carriers and prophylactic surgery to improve the prognosis of these patients. A significant number of patients with the sporadic type of MTC and even with familial disease, still present with nodal or distant metastases, making surgical cure difficult. Over the past several decades, many different types of therapy for metastatic disease have been attempted, with limited success. Improved understanding of the molecular defects and pathways involved in both familial and sporadic MTC has resulted in new hope for these patients with the development of drugs targeting the specific alterations responsible. This new era of targeted therapy with kinase inhibitors represents a significant step forward from previous trials of chemotherapy, radiotherapy, and hormonal therapy. Although much progress has been made, additional agents and strategies are needed to achieve durable, long-term responses in patients with metastatic MTC. This article reviews the history and results of medical management for metastatic MTC from the early 1970s up until the present day. PMID:24942936

  15. Diagnosis and treatment of medullary thyroid cancer.

    PubMed

    Modigliani, E; Franc, B; Niccoli-sire, P

    2000-12-01

    Medullary carcinoma of the thyroid (MTC) is a rare tumour derived from thyroid C cells with serum calcitonin as a specific and sensitive marker. MTC is inherited in 25% of cases, with an autosomal dominant transmission, age-related penetrance and variable expressivity. MTC is an obligatory component of multiple endocrine neoplasia type 2 (MEN2), which comprises three well defined syndromes: MEN2A, which may be associated with pheochromocytoma and/or hyperparathyroidism; the much rarer MEN2B, which occurs early and is accompanied by developmental abnormalities; while in contrast, familial MTC (FMTC) is not associated with any endocrinopathy. The RET proto-oncogene is the causative gene of the MEN2 syndromes and mutations in this gene are found in >90% of inherited cases, allowing easier and more reliable family screening than pentagastrin stimulation tests. Nevertheless, the correlation between the genotype and the different clinical phenotypes is not perfect. The prognosis of MTC depends on its staging at presentation, and the early appearance of cervical lymph node metastases emphasizes the need for extensive surgery, although many patients still do not normalize calcitonin levels post-operatively, and they remain a challenge for the further management.

  16. Medullary sponge kidney: state of the art.

    PubMed

    Fabris, Antonia; Anglani, Franca; Lupo, Antonio; Gambaro, Giovanni

    2013-05-01

    Medullary sponge kidney (MSK) is a kidney malformation that generally manifests with nephrocalcinosis and recurrent renal stones; other signs may be renal acidification and concentration defects, and pre-calyceal duct ectasias. MSK is generally considered a sporadic disorder, but an apparently autosomal dominant inheritance has also been observed. As MSK reveals abnormalities in both the lower and the upper nephron and is often associated with urinary tract developmental anomalies, its pathogenesis should probably be sought in one of the numerous steps characterizing renal morphogenesis. Given the key role of the GDNF-RET interaction in kidney and urinary tract development and nephrogenesis, anomalies in these molecules are reasonable candidates for explaining a disorder such as MSK. As a matter of fact, we detected two, hitherto unknown, rare variants of the GDNF gene in MSK patients. We surmise that a defective distal acidification has a central role in MSK and is followed by a chain of events including defective bone mineralization, hypercalciuria, hypocitraturia and stone formation.

  17. Surgical exclusion of postsurgical pseudoaneurysm of the ascending aorta

    PubMed Central

    Barik, Ramachandra; Patnaik, Amar Narayana; Kumar, Ravintula Venkata; Mohapatra, Rudra Prasad; Medep, Vikas; Nemani, Lalita

    2014-01-01

    Pseudoaneurysm of ascending aorta after cardiac surgery is rare in children. We report a case of successful surgical exclusion of ascending aortic pseudoaneurysm in a 15-year-old boy. The neck of the aneurysm was in close proximity to the right coronary artery (RCA). PMID:24987261

  18. Renal medullary carcinomas: histopathologic phenotype associated with diverse genotypes.

    PubMed

    Gatalica, Zoran; Lilleberg, Stan L; Monzon, Federico A; Koul, Manika Sapru; Bridge, Julia A; Knezetic, Joseph; Legendre, Ben; Sharma, Poonam; McCue, Peter A

    2011-12-01

    Chromosomal abnormalities and gene mutations have become major determinants in the classification of kidney carcinomas. Most renal medullary carcinomas develop in patients with hereditary sickle cell disease, but sporadic cases unassociated with sickle cell disease have also been described, for which underlying genetic abnormality is unknown. We evaluated 3 patients with renal medullary carcinoma (1 patient with sickle cell disease and 2 patients without sickle cell disease) for germ line and somatic mutations in genes commonly involved in pathogenesis of renal carcinomas using denaturing high-performance liquid chromatography and direct sequencing. Chromosomal abnormalities were studied by the conventional cytogenetic and SNP arrays analysis. Expression of hypoxia-inducible factor 1α was examined using immunohistochemistry. Two new mutations in the gene for fumarate hydratase were identified in 1 case of medullary renal carcinoma without sickle cell disease: a germ line mutation in exon 6 (R233H) and an acquired (somatic) mutation in exon 8 (P374S). No fumarate hydratase mutations were identified in the other 2 patients. The second sporadic case of renal medullary carcinoma harbored double somatic mutations in von Hippel-Lindau gene, and renal medullary carcinoma in the patient with sickle cell disease showed von Hippel-Lindau gene promoter methylation (epigenetic silencing). No consistent pattern of chromosomal abnormalities was found between 2 cases tested. All 3 cases showed increased hypoxia-inducible factor 1α expression. Medullary renal carcinomas from patients with or without sickle cell disease show involvement of genes important in hypoxia-induced signaling pathways. Generalized cellular hypoxia (in sickle cell disease) or pseudohypoxia (in tumors with fumarate hydratase and von Hippel-Lindau mutations or epigenetic silencing) may act alone or in concert at the level of medullary tubular epithelium to promote development of this rare type of renal

  19. HLA-DR and ß2 microglobulin expression in medullary and atypical medullary carcinoma of the breast: histopathologically similar but biologically distinct entities

    PubMed Central

    Feinmesser, M.; Sulkes, A.; Morgenstern, S.; Sulkes, J.; Stern, S.; Okon, E.

    2000-01-01

    Aims—To examine the expression of HLA-DR and ß2 microglobulin in medullary carcinoma and atypical medullary carcinoma of the breast to determine if the effective presentation of tumour antigens to the immune system can differentiate between these two histopathologically similar entities. Methods—Expression of HLA-DR and ß2 microglobulin was examined by immunohistochemical methods in five samples of medullary carcinoma of the breast, which has a relatively favourable prognosis, six samples of atypical medullary carcinoma of the breast, which has a prognosis closer to that of regular invasive duct carcinoma, and 20 samples of invasive duct carcinomas, 10 with an accompanying lymphocytic infiltrate. Results—A positive and significant correlation was found between tumour type and both HLA-DR and ß2 microglobulin expression. Expression was most prominent in medullary carcinoma, followed by atypical medullary carcinoma and invasive duct carcinoma with and without lymphocytic infiltrates. The mean intensity and percentage of HLA-DR tumour immunostaining were significantly higher in medullary carcinoma than in the other three tumour groups, as was the mean intensity of ß2 microglobulin immunostaining. Mean percentage of ß2 microglobulin immunostaining was significantly higher in medullary carcinoma than in invasive duct carcinoma without lymphocytic infiltrates, and showed a trend to increase from invasive duct carcinoma with lymphocytic infiltrates to atypical medullary carcinoma and medullary carcinoma. Conclusions—Medullary carcinoma and atypical medullary carcinoma of the breast differ in their expression of HLA-DR and ß2 microglobulin. The relatively favourable prognosis of medullary carcinoma of the breast may be related to effective tumour antigen presentation to the immune system through MHC-I and MHC-II expression. Immunotherapy aimed at MHC-I and MHC-II induction might have a beneficial effect in breast cancer. Key Words: medullary carcinoma of the

  20. Sporadic Medullary Thyroid Carcinoma: Clinical Data From A University Hospital

    PubMed Central

    Correia-Deur, Joya Emilie M.; Toledo, Rodrigo A.; Imazawa, Alice T.; Lourenço, Delmar M.; Ezabella, Marilza C. L.; Tavares, Marcos R.; Toledo, Sergio P. A.

    2009-01-01

    INTRODUCTION: Medullary thyroid carcinoma may occur in a sporadic (s-medullary thyroid carcinoma, 75%) or in a multiple endocrine neoplasia type 2 form (MEN2, 25%). These clinical forms differ in many ways, as s-medullary thyroid carcinoma cases are RET-negative in the germline and are typically diagnosed later than medullary thyroid carcinoma in MEN2 patients. In this study, a set of cases with s-medullary thyroid carcinoma are documented and explored. PURPOSE: To document the phenotypes observed in s-medullary thyroid carcinoma cases from a university group and to attempt to improve earlier diagnosis of s-medullary thyroid carcinoma. Some procedures for diagnostics are also recommended. METHOD: Patients (n=26) with apparent s-medullary thyroid carcinoma were studied. Their clinical data were reviewed and peripheral blood was collected and screened for RET germline mutations. RESULTS: The average age at diagnosis was 43.9 years (± 10.82 SD) and did not differ between males and females. Calcitonin levels were increased in all cases. Three patients presented values that were 100-fold greater than the normal upper limit. Most (61.54%) had values that were 20-fold below this limit. Carcinoembryonic antigen levels were high in 70.6% of cases. There was no significant association between age at diagnosis, basal calcitonin levels or time of disease onset with thyroid tumor size (0.6–15 cm). Routine thyroid cytology yielded disappointing diagnostic accuracy (46.7%) in this set of cases. After total thyroidectomy associated with extensive cervical lymph node resection, calcitonin values remained lower than 5 pg/mL for at least 12 months in eight of the cases (30.8%). Immunocyto- and histochemistry for calcitonin were positive in all analyzed cases. None of the 26 cases presented germline mutations in the classical hotspots of the RET proto-oncogene. CONCLUSION: Our cases were identified late. The basal calcitonin measurements and immunostaining for calcitonin were

  1. Medullary catecholaminergic projections to the ventrolateral periaqueductal gray region activated by halothane anaesthesia.

    PubMed

    Clement, C I; Keay, K A; Bandler, R

    1998-10-01

    Under anaesthesia, blood loss and deep pain can evoke a premature, centrally-mediated sympathoinhibition leading to decompensated shock and sometimes even death. The central circuits evoking premature vasodepressor syncope are unknown, although medullary catecholaminergic pathways have been implicated. The ventrolateral periaqueductal gray region is one of only three brain regions in which catecholamine content is increased during halothane anaesthesia. The ventrolateral periaqueductal gray also contains neurons which are selectively activated by blood loss and deep pain, and recent work from our laboratory has suggested that it is a pivotal structure in central sympathoinhibitory circuits. Using retrograde tracing techniques combined with the immunohistochemical detection of: (i) the catecholamine synthetic enzyme, tyrosine hydroxylase and (ii) the protein product of the immediate-early gene c-fos as a marker of neuronal activation; the results of this study indicate that catecholaminergic projections from the A1, C1 and C2 regions of the medulla to the ventrolateral periaqueductal gray are activated by halothane anaesthesia. These data are consistent with the hypotheses that ascending catecholaminergic projections to the ventrolateral periaqueductal gray: (i) are a component of the central neural circuitry responsible for the sympathoinhibitory effects of halothane anaesthesia, and (ii) may contribute to the premature elicitation of vasodepressor syncope following blood loss and deep pain under conditions of anaesthesia.

  2. [Ascending aorta replacement late after aortic valve replacement].

    PubMed

    Hayashi, Yasunari; Ito, Toshiaki; Maekawa, Atsuo; Sawaki, Sadanari; Fujii, Genyo; Hoshino, Satoshi; Tokoro, Masayoshi; Yanagisawa, Junji

    2013-07-01

    Replacement of the asceding aorta is indicated in patients undergoing aortic valve replacement( AVR), if the diameter of the ascending aorta is greater than 5.0 cm. If the diameter of the asceding aorta is from 4.0 to 5.0 cm, it was arguable whether replacement of the ascending aorta should be performed. Nine patients who underwent reoperative ascending aorta replacement after AVR were reviewed retrospectively. Reoperation on the asending aorta replacement was performed 11.8±7.2 years (range 1y5m~23y3m) after AVR. Mean patient age was 69.9±6.3 (range 60~81). In 2 cases, reoperations were performed early year after AVR. Although ascending aorta was dilated at the 1st operation, replacement wasn't performed for the age and minimally invasive cardiac surgery (MICS). In 3 cases, reoperations were performed more than 10 years later. On these cases, ascending aorta aneurysm and dissection occurred with no pain and were pointed out by computed tomography(CT) or ultrasonic cardiogram(UCG). We think that patients with dilatation of the ascending aorta should undergo AVR and aorta replacement at the 1st operation regardness of age. It is important that patients who underwent AVR should undergo a regular checkup on the ascending aorta.

  3. An Association of Chronic Hyperaldosteronism with Medullary Nephrocalcinosis

    PubMed Central

    Mittal, Kartik; Anandpara, Karan; Dey, Amit K.; Sharma, Rajaram; Thakkar, Hemangini; Hira, Priya; Deshmukh, Hemant

    2015-01-01

    Summary Background An association between chronic hyperaldosteronism and medullary nephrocalcinosis has rarely been made, with only a handful of cases described in literature. Case Report We describe five cases of hyperaldosteronism with a long- standing history in whom associated medullary nephrocalcinosis was established. Conclusions We infer that a chronic hyperaldosteronic status, whether primary or secondary, is a causal factor in the etiopathogenesis of medullary nephrocalcinosis. This article illustrates and summarizes various postulated theories that support our proposed association between hyperaldosteronism and nephrocalcinosis. We conclude that chronic hyperaldosteronism should be included as one of the causes of nephrocalcinosis and that our case series emphasizes the need of a well-organized retrospective study to prove it further. PMID:26413177

  4. Laterality of bolus passage through the pharynx in patients with unilateral medullary infarction.

    PubMed

    Mikushi, Shinya; Kagaya, Hitoshi; Baba, Mikoto; Tohara, Haruka; Saitoh, Eiichi

    2014-02-01

    Laterality of bolus passage in the pharynx is often seen in patients with medullary infarction. We evaluated the dominant side of bolus passage in the pharynx and investigated the factors that cause the passage to dominantly occur on the affected side. Forty-one patients (35 men and 6 women, 64 ± 9 years) with unilateral medullary infarction participated in this study. Bolus passage of 4 mL of thick liquid was evaluated in 3 regions (oropharyngeal, thyropharyngeal, and cricopharyngeal) and classified into 4 patterns (dominantly on the unaffected side [UAS], on both sides without clear laterality [BS], dominantly on the affected side [AS], and nonpassage of the bolus [NP]) by videofluoroscopic examination of swallowing. The bolus passages were as follows: UAS, BS, and AS occurred in 2, 32, and 7 patients in the oropharyngeal region; UAS, BS, and AS occurred in 5, 20, and 16 patients in the thyropharyngeal region; and UAS, BS, AS, and NP occurred in 11, 9, 10, and 11 patients in the cricopharyngeal region, respectively. In the thyropharyngeal region, the proportion of patients in whom the swallowing reflex occurred when the bolus was in the oropharynx and the proportion of patients with unilateral pharyngeal constrictor paralysis were greater in patients whose bolus passage was AS than in patients whose passage was BS. This suggests that the bolus predominantly passed through the affected side of the thyropharyngeal portion because of the asymmetry of pharyngeal contraction during swallowing in the early period after onset.

  5. Angiotensin II Induces a Region-Specific Hyperplasia of the Ascending Aorta Through Regulation of Inhibitor of Differentiation 3

    PubMed Central

    Owens, A. Phillip; Subramanian, Venkateswaran; Moorleghen, Jessica J.; Guo, Zhenheng; McNamara, Coleen A.; Cassis, Lisa A; Daugherty, Alan

    2010-01-01

    Rationale Angiotensin II (AngII) has diverse effects on smooth muscle cells. The diversity of effects may relate to the regional location of this cell type. Objective The aim of this study was to define whether AngII exerted divergent effects on smooth muscle cells (SMC) in the aorta and determine the role of blood pressure and specific oxidant mechanisms. Methods and Results AngII (1,000 ng/kg/min) infusion for 28 days into mice increased systolic blood pressure (SBP) and promoted medial expansion of equivalent magnitude throughout the entire aorta. Both effects were ablated by AT1a receptor deficiency. Similar increases in blood pressure by administration of norepinephrine promoted no changes in aortic medial thickness. Increased medial thickness was due to SMC expansion attributable to hypertrophy in most aortic regions, with the exception of hyperplasia of the ascending aorta. Deficiency of the p47phox component of NADPH oxidase ablated AngII-induced medial expansion in all aortic regions. Analysis of mRNA and protein throughout the aorta revealed a much higher abundance of the inhibitor of differentiation 3 (Id3) in the ascending aorta compared to all other regions. A functional role was demonstrated by Id3 deficiency inhibiting AngII-induced SMC hyperplasia of the ascending aorta. Conclusions In conclusion, AngII promotes both aortic medial hypertrophy and hyperplasia in a region-specific manner via an oxidant mechanism. The ascending aortic hyperplasia is dependent on Id3. PMID:20019328

  6. Mixed medullary and follicular carcinoma of the thyroid.

    PubMed

    Pfaltz, M; Hedinger, C E; Mühlethaler, J P

    1983-01-01

    We report a case of medullary carcinoma of the thyroid which on light microscopy showed not only the well known arrangement of cells in sheets and nests but also unequivocal follicular structures. These follicular structures are present both in the primary tumor and in lymph node metastases. Immunohistochemical investigations revealed that the cells lining the follicles produce thyroglobulin, whereas the remaining tumor tissue is positive for calcitonin and carcinoembrionic antigen. This case represents a medullary carcinoma of the thyroid with an atypical pattern consisting of both thyroglobulin and calcitonin producing cells.

  7. [Medullary thyroid carcinoma and other rare types of thyroid carcinoma].

    PubMed

    Obara, Takao

    2007-11-01

    Among 4 major traditional groups of thyroid carcinoma, papillary and follicular carcinomas are most common, and other forms, anaplastic and medullary carcinomas, are relatively rare. The 2003 WHO histological classification of thyroid tumor separated 7 other malignant thyroid tumors into distinct pathological entities, such as poorly differentiated, squamous cell, mucinous carcinomas, carcinoma showing thymus-like differentiation (CASTLE), etc. Although they are also extremely rare, recognition of their clinicopathologic features are very important. In this review, not only diagnostic and therapeutic strategies for the rare forms of thyroid carcinomas, specifically focussed on medullary carcinoma and CASTLE, but also their histogenetic abnormalities were discussed.

  8. The ascending pathophysiology of cholestatic liver disease.

    PubMed

    Jansen, Peter L M; Ghallab, Ahmed; Vartak, Nachiket; Reif, Raymond; Schaap, Frank G; Hampe, Jochen; Hengstler, Jan G

    2017-02-01

    In this review we develop the argument that cholestatic liver diseases, particularly primary biliary cholangitis and primary sclerosing cholangitis (PSC), evolve over time with anatomically an ascending course of the disease process. The first and early lesions are in "downstream" bile ducts. This eventually leads to cholestasis, and this causes bile salt (BS)-mediated toxic injury of the "upstream" liver parenchyma. BS are toxic in high concentration. These concentrations are present in the canalicular network, bile ducts, and gallbladder. Leakage of bile from this network and ducts could be an important driver of toxicity. The liver has a great capacity to adapt to cholestasis, and this may contribute to a variable symptom-poor interval that is often observed. Current trials with drugs that target BS toxicity are effective in only about 50%-60% of primary biliary cholangitis patients, with no effective therapy in PSC. This motivated us to develop and propose a new view on the pathophysiology of primary biliary cholangitis and PSC in the hope that these new drugs can be used more effectively. These views may lead to better stratification of these diseases and to recommendations on a more "tailored" use of the new therapeutic agents that are currently tested in clinical trials. Apical sodium-dependent BS transporter inhibitors that reduce intestinal BS absorption lower the BS load and are best used in cholestatic patients. The effectiveness of BS synthesis-suppressing drugs, such as farnesoid X receptor agonists, is greatest when optimal adaptation is not yet established. By the time cytochrome P450 7A1 expression is reduced these drugs may be less effective. Anti-inflammatory agents are probably most effective in early disease, while drugs that antagonize BS toxicity, such as ursodeoxycholic acid and nor-ursodeoxycholic acid, may be effective at all disease stages. Endoscopic stenting in PSC should be reserved for situations of intercurrent cholestasis and

  9. A mathematical model of rat ascending Henle limb. III. Tubular function.

    PubMed

    Weinstein, Alan M

    2010-03-01

    K+ plays a catalytic role in AHL Na+ reabsorption via Na+-K+-2Cl- cotransporter (NKCC2), recycling across luminal K+ channels, so that luminal K+ is not depleted. Based on models of the ascending Henle limb (AHL) epithelium, it has been hypothesized that NH4+ may also catalyze luminal Na+ uptake. This hypothesis requires that luminal NH4+ not be depleted, implying replenishment via either direct secretion of NH4+, or NH3 in parallel with a proton. In the present work, epithelial models of rat medullary and cortical AHL (Weinstein AM, Krahn TA. Am J Physiol Renal Physiol 298: F000-F000, 2009) are configured as tubules and examined in simulations of function in vitro and in vivo to assess the feasibility of a catalytic role for NH4+ in Na+ reabsorption. Modulation of Na+ transport is also examined by peritubular K+ concentration and by Bartter-type transport defects in NKCC2 (type 1), in luminal membrane K+ channels (type 2), and in peritubular Cl- channels (type 3). It is found that a catalytic role for NH4+, which is significant in magnitude (relative to K+), is quantitatively realistic, in terms of uptake via NKCC2, and in terms of luminal membrane ammonia backflux. Simulation of a 90% NKCC2 defect is predicted to double distal Na+ delivery; it is also predicted to increase distal acid delivery (principally as NH4+). With doubling of medullary K+, the model predicts a 30% increase in distal Na+ delivery, but in this case there is a decrease in AHL acidification. This effect of peritubular K+ on proton secretion appears to be akin to type 3 Bartter's pathophysiology, in which there is decreased peritubular HCO3- exit, cytosolic alkalinization, and a consequent decrease in luminal proton secretion by NHE3. One consequence of overlapping and redundant roles for K+ and NH4+, is a blunted impact of luminal membrane K+ permeability on overall Na+ reabsorption, so that type 2 Bartter pathophysiology is not well captured by the model.

  10. Technology advancement for the ASCENDS mission using the ASCENDS CarbonHawk Experiment Simulator (ACES)

    NASA Astrophysics Data System (ADS)

    Obland, M. D.; Antill, C.; Browell, E. V.; Campbell, J. F.; CHEN, S.; Cleckner, C.; Dijoseph, M. S.; Harrison, F. W.; Ismail, S.; Lin, B.; Meadows, B. L.; Mills, C.; Nehrir, A. R.; Notari, A.; Prasad, N. S.; Kooi, S. A.; Vitullo, N.; Dobler, J. T.; Bender, J.; Blume, N.; Braun, M.; Horney, S.; McGregor, D.; Neal, M.; Shure, M.; Zaccheo, T.; Moore, B.; Crowell, S.; Rayner, P. J.; Welch, W.

    2013-12-01

    The ASCENDS CarbonHawk Experiment Simulator (ACES) is a NASA Langley Research Center project funded by NASA's Earth Science Technology Office that seeks to advance technologies critical to measuring atmospheric column carbon dioxide (CO2) mixing ratios in support of the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. The technologies being advanced are: (1) multiple transmitter and telescope-aperture operations, (2) high-efficiency CO2 laser transmitters, (3) a high bandwidth detector and transimpedance amplifier (TIA), and (4) advanced algorithms for cloud and aerosol discrimination. The instrument architecture is being developed for ACES to operate on a high-altitude aircraft, and it will be directly scalable to meet the ASCENDS mission requirements. The above technologies are critical for developing an airborne simulator and spaceborne instrument with lower platform consumption of size, mass, and power, and with improved performance. This design employs several laser transmitters and telescope-apertures to demonstrate column CO2 retrievals with alignment of multiple laser beams in the far-field. ACES will transmit five laser beams: three from commercial lasers operating near 1.57-microns, and two from the Exelis atmospheric oxygen (O2) fiber laser amplifier system operating near 1.26-microns. The Master Oscillator Power Amplifier at 1.57-microns measures CO2 column concentrations using an Integrated-Path Differential Absorption (IPDA) lidar approach. O2 column amounts needed for calculating the CO2 mixing ratio will be retrieved using the Exelis laser system with a similar IPDA approach. The three aperture telescope design was built to meet the constraints of the Global Hawk high-altitude unmanned aerial vehicle (UAV). This assembly integrates fiber-coupled transmit collimators for all of the laser transmitters and fiber-coupled optical signals from the three telescopes to the aft optics and detector package. The detector

  11. Medullary serotonin neurons are CO2 sensitive in situ

    PubMed Central

    Richerson, George B.; Harris, Michael B.

    2013-01-01

    Brainstem central chemoreceptors are critical to the hypercapnic ventilatory response, but their location and identity are poorly understood. When studied in vitro, serotonin-synthesizing (5-HT) neurons within the rat medullary raphé are intrinsically stimulated by CO2/acidosis. The contributions of these neurons to central chemosensitivity in vivo, however, are controversial. Lacking is documentation of CO2-sensitive 5-HT neurons in intact experimental preparations and understanding of their spatial and proportional distribution. Here we test the hypothesis that 5-HT neurons in the rat medullary raphé are sensitive to arterial hypercapnia. We use extracellular recording and hypercapnic challenge of spontaneously active medullary raphé neurons in the unanesthetized in situ perfused decerebrate brainstem preparation to assess chemosensitivity of individual cells. Juxtacellular labeling of a subset of recorded neurons and subsequent immunohistochemistry for the 5-HT-synthesizing enzyme tryptophan hydroxylase (TPH) identify or exclude this neurotransmitter phenotype in electrophysiologically characterized chemosensitive and insensitive cells. We show that the medullary raphé houses a heterogeneous population, including chemosensitive and insensitive 5-HT neurons. Of 124 recorded cells, 16 cells were juxtacellularly filled, visualized, and immunohistochemically identified as 5-HT synthesizing, based on TPH-immunoreactivity. Forty-four percent of 5-HT cells were CO2 stimulated (increased firing rate with hypercapnia), while 56% were unstimulated. Our results demonstrate that medullary raphé neurons are heterogeneous and clearly include a subset of 5-HT neurons that are excited by arterial hypercapnia. Together with data identifying intrinsically CO2-sensitive 5-HT neurons in vitro, these results support a role for such cells as central chemoreceptors in the intact system. PMID:24047906

  12. Microsurgical anatomy of the arterial basket of the conus medullaris.

    PubMed

    Martirosyan, Nikolay L; Kalani, M Yashar S; Lemole, G Michael; Spetzler, Robert F; Preul, Mark C; Theodore, Nicholas

    2015-06-01

    OBJECT The arterial basket of the conus medullaris (ABCM) consists of 1 or 2 arteries arising from the anterior spinal artery (ASA) and circumferentially connecting the ASA and the posterior spinal arteries (PSAs). The arterial basket can be involved in arteriovenous fistulas and arteriovenous malformations of the conus. In this article, the authors describe the microsurgical anatomy of the ABCM with emphasis on its morphometric parameters and important role in the intrinsic blood supply of the conus medullaris. METHODS The authors performed microsurgical dissections on 16 formalin-fixed human spinal cords harvested within 24 hours of death. The course, diameter, and branching angles of the arteries comprising the ABCM were then identified and measured. In addition, histological sections were obtained to identify perforating vessels arising from the ABCM. RESULTS The ASA tapers as it nears the conus medullaris (mean preconus diameter 0.7 ± 0.12 mm vs mean conus diameter 0.38 ± 0.08 mm). The ASA forms an anastomotic basket with the posterior spinal artery (PSA) via anastomotic branches. In most of the specimens (n= 13, 81.3%), bilateral arteries formed connections between the ASA and PSA. However, in the remaining specimens (n= 3, 18.7%), a unilateral right-sided anastomotic artery was identified. The mean diameter of the right ABCM branch was 0.49 ± 0.13 mm, and the mean diameter of the left branch was 0.53 ± 0.14 mm. The mean branching angles of the arteries forming the anastomotic basket were 95.9° ± 36.6° and 90° ± 34.3° for the right- and left-sided arteries, respectively. In cases of bilateral arterial anastomoses between the ASA and PSA, the mean distance between the origins of the arteries was 4.5 ± 3.3 mm. Histological analysis revealed numerous perforating vessels supplying tissue of the conus medullaris. CONCLUSIONS The ABCM is a critical anastomotic connection between the ASA and PSA, which play an important role in the intrinsic blood supply

  13. Russell-Silver syndrome associated with low conus medullaris.

    PubMed

    Gabor, Larisa; Canaz, Huseyin; Canaz, Gokhan; Kara, Nursu; Alatas, Ibrahim; Bozkus, Hakan

    2016-01-01

    Russell-Silver syndrome is a rare heterogeneous disorder mainly characterized by intrauterine and postnatal growth retardation, craniofacial disproportion, clinodactyly, variation in urogenital development, and skeletal asymmetry. It is rare to come across tethered cord-associated Russell-Silver syndrome. We report a rare case of Russell-Silver syndrome associated with low conus medullaris in a 2-year-old patient with demonstrative phenotype. Magnetic resonance imaging indicated a low conus medullaris at the inferior border of the L3 vertebral body. Urodynamic study revealed detrusor-sphincter dyssynergia and detrusor overactivity. A decision to follow-up the patient was made because of the suspicion of tethered cord syndrome. Even though tethered cord syndrome is not a common finding in Russell-Silver syndrome, it is important to consider tethered cord syndrome to avoid scoliosis and other long-term complications.

  14. Effect of Space Flight on Adrenal Medullary Function

    NASA Technical Reports Server (NTRS)

    Lelkes, Peter I.

    1999-01-01

    We hypothesize that microgravity conditions during space flight alter the expression and specific activities of the adrenal medullary CA synthesizing enzymes (CASE). Previously, we examined adrenals from six rats flown for six days aboard STS 54 and reported that microgravity induced a decrease in the expression and specific activity of rat adrenal medullary tyrosine hydroxylase, the rate limiting enzyme of CA synthesis, without affecting the expression of other CASE. In the past, we analyzed some of the > 300 adrenals from two previous Space Shuttle missions (PARE 03 and SLS 2). The preliminary results (a) attest to the good state of tissue preservation, thus proving the feasibility of subsequent large-scale evaluation, and (b) confirm and extend our previous findings. With this grant we will be able to expeditiously analyze all our specimens and to complete our studies in a timely fashion.

  15. Russell–Silver syndrome associated with low conus medullaris

    PubMed Central

    Gabor, Larisa; Canaz, Huseyin; Canaz, Gokhan; Kara, Nursu; Alatas, Ibrahim; Bozkus, Hakan

    2016-01-01

    Russell–Silver syndrome is a rare heterogeneous disorder mainly characterized by intrauterine and postnatal growth retardation, craniofacial disproportion, clinodactyly, variation in urogenital development, and skeletal asymmetry. It is rare to come across tethered cord-associated Russell–Silver syndrome. We report a rare case of Russell–Silver syndrome associated with low conus medullaris in a 2-year-old patient with demonstrative phenotype. Magnetic resonance imaging indicated a low conus medullaris at the inferior border of the L3 vertebral body. Urodynamic study revealed detrusor-sphincter dyssynergia and detrusor overactivity. A decision to follow-up the patient was made because of the suspicion of tethered cord syndrome. Even though tethered cord syndrome is not a common finding in Russell–Silver syndrome, it is important to consider tethered cord syndrome to avoid scoliosis and other long-term complications. PMID:28217167

  16. Medullary sponge kidney and testicular dysgenesis syndrome: a rare association.

    PubMed

    Masciovecchio, Stefano; Saldutto, Pietro; Paradiso Galatioto, Giuseppe; Vicentini, Carlo

    2014-01-01

    The medullary sponge kidney is also known as Lenarduzzi's kidney or Cacchi and Ricci's disease from the first Italian authors who described its main features. A review of the scientific literature underlines particular rarity of the association of MSK with developmental abnormalities of the lower urinary tract and genital tract such as hypospadias and bilateral cryptorchidism. The work presented is the only one in the scientific literature that shows the association between the medullary sponge kidney and the testicular dysgenesis syndrome. A question still remains unanswered: are the MSK and TDS completely independent malformation syndromes occurring, in this case, simultaneously for a rare event or are they different phenotypic expressions of a common malformative mechanism? In the future we hope that these questions will be clarified.

  17. Medullary Sponge Kidney and Testicular Dysgenesis Syndrome: A Rare Association

    PubMed Central

    Masciovecchio, Stefano; Saldutto, Pietro; Paradiso Galatioto, Giuseppe; Vicentini, Carlo

    2014-01-01

    The medullary sponge kidney is also known as Lenarduzzi's kidney or Cacchi and Ricci's disease from the first Italian authors who described its main features. A review of the scientific literature underlines particular rarity of the association of MSK with developmental abnormalities of the lower urinary tract and genital tract such as hypospadias and bilateral cryptorchidism. The work presented is the only one in the scientific literature that shows the association between the medullary sponge kidney and the testicular dysgenesis syndrome. A question still remains unanswered: are the MSK and TDS completely independent malformation syndromes occurring, in this case, simultaneously for a rare event or are they different phenotypic expressions of a common malformative mechanism? In the future we hope that these questions will be clarified. PMID:24716085

  18. Medullary carcinoma of the colon: can the undifferentiated be differentiated?

    PubMed

    Fiehn, Anne-Marie Kanstrup; Grauslund, Morten; Glenthøj, Anders; Melchior, Linea Cecilie; Vainer, Ben; Willemoe, Gro Linno

    2015-01-01

    Medullary carcinoma of the colon is a rare variant of colorectal cancer claimed to have a more favorable prognosis than conventional adenocarcinomas. The histopathologic appearance may be difficult to distinguish from poorly differentiated adenocarcinoma. The study aimed to evaluate the diagnostic interobserver agreement and to characterize the immunohistochemical and molecular differences between these two subgroups. Fifteen cases initially classified as medullary carcinoma and 30 cases of poorly differentiated adenocarcinomas were included. Two pathologists reviewed the slides independently without knowledge of the original diagnosis and subgrouped the tumors into the two entities. Agreement was reached in 31 of 45 cases (69 %) with kappa = 0.32. An extensive immunohistochemical panel was performed, and KRAS, NRAS, and BRAF mutational status was assessed. Of the 31 cases with diagnostic agreement, the expression of only MLH-1 along with corresponding expression of PMS-2 differed significantly (p = 0.04). A high rate of BRAF mutations was detected in both subgroups without significant differences. Expression of MLH-1 was superior in dividing the tumors into two separate entities with significant differences in CK20 (p = 0.005) expression and in the rate of BRAF mutations (p = 0.0035). In conclusion, medullary carcinomas of the colon are difficult to discriminate from poorly differentiated adenocarcinoma even with the help of immunohistochemical and molecular analyses. This raises the question whether these morphological subtypes should be maintained or whether an alternative classification of poorly differentiated colorectal adenocarcinomas based on MLH-1 status rather than morphology should be suggested.

  19. Effect of chronic renal medullary nitric oxide inhibition on blood pressure.

    PubMed

    Mattson, D L; Lu, S; Nakanishi, K; Papanek, P E; Cowley, A W

    1994-05-01

    The effects of chronic nitric oxide inhibition in the renal medulla on renal cortical and medullary blood flow, sodium balance, and blood pressure were evaluated in conscious uninephrectomized Sprague-Dawley rats. During a 5-day renal medullary interstitial infusion of the nitric oxide inhibitor NG-nitro-L-arginine methyl ester (L-NAME, 120 micrograms/h) in saline (0.5 ml/min), renal medullary blood flow was selectively decreased by 30% after 2 h and was maintained at that level for the entire infusion. The decrease in medullary blood flow was associated with sodium retention and increased blood pressure. After the cessation of L-NAME infusion, medullary blood flow returned to control, and the sodium balance became negative as blood pressure returned to baseline. These data indicate that renal medullary nitric oxide plays an important role in the regulation of renal blood flow, sodium excretion, and blood pressure.

  20. Analytical Description of Ascending Motion of Rockets in the Atmosphere

    ERIC Educational Resources Information Center

    Rodrigues, H.; de Pinho, M. O.; Portes, D., Jr.; Santiago, A.

    2009-01-01

    In continuation of a previous work, we present an analytic study of ascending vertical motion of a rocket subjected to a quadratic drag for the case where the mass-variation law is a linear function of time. We discuss the detailed analytical solution of the model differential equations in closed form. Examples of application are presented and…

  1. Ascending performance analysis for high altitude zero pressure balloon

    NASA Astrophysics Data System (ADS)

    Saleh, Sherif; He, Weiliang

    2017-04-01

    This paper describes a comprehensive simulation for high altitude zero pressure balloon trajectories. A mathematical model was established to simulate the ascending process which considers the atmospheric conditions and thermodynamic variations. Influences of launch parameters on ascending performance were analyzed. The necessary quantity of initial lift gas was estimated and optimized, so that ensures no ballast consuming during the ascending process. The climbing rate was a governing parameter to evaluate the ascending performance. Based on the simulation, results revealed the apparent different effect on climbing rate at troposphere and stratosphere layers. Change in launch time and site mainly affect the climbing rate at the stratosphere and have no significant effect at the troposphere and tropopause altitudes. Meanwhile, change in launch date has a negligible effect on both layers. Due to the earth's declination angle, the influence of the same launch latitude and the same launch longitude is not identical within a year. Also, results showed that the optimum lift gas quantity improved the climbing rate stability to obtain an accurate simulation.

  2. Involvement of medullary serotonergic groups in multiple system atrophy.

    PubMed

    Benarroch, Eduardo E; Schmeichel, Ann M; Low, Phillip A; Parisi, Joseph E

    2004-03-01

    We sought to determine whether medullary serotonergic neurons were affected in multiple system atrophy (MSA). Immunostaining for tryptophan hydroxylase was performed on serial 50 microm sections of the medulla of brains obtained at autopsy from six control subjects, eight subjects with clinical diagnosis of MSA, and four with Parkinson's disease. There was a severe depletion of serotonergic neurons in the nucleus raphe magnus, raphe obscurus, raphe pallidus, and ventrolateral medulla in MSA. Depletion of serotonergic neurons may contribute to impaired control of sympathetic outflow and other abnormalities in MSA.

  3. Ependymoma of conus medullaris presenting as subarachnoid haemorrhage.

    PubMed

    Ulrich, C T; Beck, J; Seifert, V; Marquardt, G

    2008-02-01

    Subarachnoid haemorrhage (SAH) due to spinal ependymoma is very rare. We report a 37 year old man who presented with typical clinical signs of SAH. Lumbar puncture confirmed SAH but cerebral angiography was negative, and further diagnostic work-up revealed an ependymoma of the conus medullaris as the source of the haemorrhage. A comprehensive review of the literature was conducted. Only 17 patients with spontaneous SAH due to a spinal ependymoma have been reported since 1958. However, in cases of SAH and negative diagnostic findings for cerebral aneurysms or malformations, this aetiology should be considered and work-up of the spinal axis completed.

  4. Ascending and plunging ranula in a pediatric patient.

    PubMed

    Clyburn, Virginia L; Smith, Jacob E; Rumboldt, Tihana; Matheus, Maria G; Day, Terry A

    2009-06-01

    A plunging ranula is a rare phenomenon that represents mucous extravasation extending through or behind the mylohyoid. The mucous dissects the tissue planes inferiorly and usually manifests as a swelling in the submental or submandibular regions. Some plunging ranulas are believed to result from disruption of excretory ducts that originate from the sublingual gland. The currently accepted definitive treatment of a plunging ranula is resection of the ipsilateral sublingual gland and evacuation of the cyst with removal of the pseudocapsule. There have been no reported cases of "ascending" ranulas into the parapharyngeal or pterygomaxillary space. The following represents the first known case that involved an extensive ascending and plunging ranula in a pediatric patient, which recurred despite complete excision of the ranula and sublingual gland. IRB approval was not required per institutional policy on retrospective case reports.

  5. Chronic anisakiasis of the ascending colon associated with carcinoma.

    PubMed

    Mineta, Sho; Shimanuki, Kimiyoshi; Sugiura, Atsushi; Tsuchiya, Yoshikazu; Kaneko, Masahiro; Sugiyama, Yoshihiko; Akimaru, Koho; Tajiri, Takashi

    2006-06-01

    Chronic anisakiasis of the colon is rare and difficult to diagnose. We report a case of chronic anisakiasis associated with advanced colonic carcinoma. A 69-year-old man was admitted for abdominal pain, diarrhea, and urticaria. Right hemicolectomy was performed because of an obstruction of the ascending colon and a palpable tumor of the right lower abdomen. The lesion was thought to be located in the deeper layers of the ascending colon. Preoperative examinations failed to detect the coexistence of anisakiasis and carcinoma of the colon. The anisakis was identified morphologically in the intestinal wall of the resected specimen and by an elevated titer of an IgE antibody specific to the parasite. Seventy-five cases of colonic and rectal anisakiasis, including the present case, have been reported in Japan. This is the only reported case of anisakiasis to appear in association with colonic carcinoma.

  6. Successful Thrombectomy for an Idiopathic Floating Ascending Aortic Thrombus.

    PubMed

    Pang, Philip Y K; Nathan, Viswa B

    2016-09-01

    A mobile thrombus in an otherwise normal ascending aorta is rare, but it should be thoroughly searched for in patients with unexplained cerebral or peripheral embolism. We report the case of a 49-year-old man admitted for right lower quadrant abdominal pain secondary to embolic renal infarction. Echocardiography and computed tomography of the chest revealed a 2.5 cm × 1.5 cm hypermobile mass at the distal ascending aorta, which was otherwise normal. No hypercoagulable condition could be identified. The mass was successfully removed with the patient under deep hypothermic circulatory arrest and was confirmed to be a thrombus. The cause of this thrombus remains unknown.

  7. False aneurysm of ascending aorta due to pericardial mesothelioma†

    PubMed Central

    Uspenskiy, Vladimir; Lavreshin, Alexei; Osadchii, Alexei; Gordeev, Michael

    2012-01-01

    Ascending aortic false aneurysm is a rare but serious complication of pericardial mesothelioma. We report a case of ascending aortic pseudoaneurysm due to spindle cell pericardial mesothelioma. In this case, the first symptoms of the disease appeared 18 months before surgery. The final diagnosis was determined only when severe late complications occurred. Palliative tumour excision, aortoplasty and aortic valve prosthesis were performed with subsequent adjuvant chemotherapy. Over 10 months after surgery, the patient is alive and a significant reduction of the tumour mass has been achieved. This case demonstrates that timely lifetime diagnosis of malignant pericardial tumour remains very difficult and effective adjuvant chemotherapy is needed to improve the results of surgery. PMID:22593561

  8. Repair of a penetrating ascending aortic ulcer with localized resection and extracellular matrix patch aortoplasty.

    PubMed

    Smith, Craig R; Stamou, Sotiris C; Boeve, Theodore J; Hooker, Robert C

    2012-09-01

    Penetrating ascending aortic ulcers are rarely encountered, yet they present significant risk of hemorrhage and aortic dissection. Expedient recognition and repair is of vital importance. The current management of penetrating ulcer of the ascending aorta includes replacement of the ascending aorta with a prosthetic graft. We describe our technique of repairing a penetrating ulcer of the ascending aorta with localized ulcer resection and extracellular matrix patch aortoplasty.

  9. Fully automatic segmentation of femurs with medullary canal definition in high and in low resolution CT scans.

    PubMed

    Almeida, Diogo F; Ruben, Rui B; Folgado, João; Fernandes, Paulo R; Audenaert, Emmanuel; Verhegghe, Benedict; De Beule, Matthieu

    2016-12-01

    Femur segmentation can be an important tool in orthopedic surgical planning. However, in order to overcome the need of an experienced user with extensive knowledge on the techniques, segmentation should be fully automatic. In this paper a new fully automatic femur segmentation method for CT images is presented. This method is also able to define automatically the medullary canal and performs well even in low resolution CT scans. Fully automatic femoral segmentation was performed adapting a template mesh of the femoral volume to medical images. In order to achieve this, an adaptation of the active shape model (ASM) technique based on the statistical shape model (SSM) and local appearance model (LAM) of the femur with a novel initialization method was used, to drive the template mesh deformation in order to fit the in-image femoral shape in a time effective approach. With the proposed method a 98% convergence rate was achieved. For high resolution CT images group the average error is less than 1mm. For the low resolution image group the results are also accurate and the average error is less than 1.5mm. The proposed segmentation pipeline is accurate, robust and completely user free. The method is robust to patient orientation, image artifacts and poorly defined edges. The results excelled even in CT images with a significant slice thickness, i.e., above 5mm. Medullary canal segmentation increases the geometric information that can be used in orthopedic surgical planning or in finite element analysis.

  10. [Takayasu's disease disclosed by isolated involvement of the ascending aorta].

    PubMed

    Marcaggi, X; Courant, N; Soubrier, M; Kemeny, J L; Camilleri, L; Lusson, J R; Cassagnes, J

    1992-03-01

    The authors report the histological discovery of a case of Takayasu syndrome affecting the ascending aorta. This involvement appearing to concern only the aorta, with no symptomatic complaints nor any laboratory abnormalities indicative of an inflammatory syndrome, corticosteroids were not prescribed. Management consisted of biennial monitoring by transthoracic and transesophageal ultrasonography of the aorta and the supra-aortic main vessels together with monitoring of laboratory parameters.

  11. Replacement of the heavily calcified ascending aorta in aortic valve replacement.

    PubMed

    Matsumoto, Kazuhisa; Hisashi, Yosuke; Imoto, Yutaka

    2015-03-01

    A totally calcified ascending aorta prevents aortic crossclamping and aortotomy during aortic valve replacement, and replacement of the ascending aorta is a valid option in these cases. We describe a simple technique for calcified ascending aorta replacement using the Cavitron Ultrasonic Surgical Aspirator. This can be used in aortic endarterectomy for removal of the calcified plaque in the anastomotic part.

  12. Protective effect of angiotensin II-induced increase in nitric oxide in the renal medullary circulation.

    PubMed

    Zou, A P; Wu, F; Cowley, A W

    1998-01-01

    This study examined the effect of intravenous infusion of subpressor doses of angiotensin (Ang II) on renal medullary blood flow (MBF), medullary partial oxygen pressure (PO2), and nitric oxide (NO) concentration under normal conditions and during reduction of the medullary nitric oxide synthase (NOS) activity in anesthetized rats. With laser Doppler flowmetry and polarographic measurement of PO2 with microelectrodes, Ang II (5 ng/kg per minute) did not alter renal cortical and medullary blood flows or medullary PO2. N(omega)-nitro-L-arginine methyl ester (L-NAME) was infused into the renal medullary interstitial space at a dose of 1.4 microg/kg per minute, a dose that did not significantly alter basal levels of MBF or PO2. Intravenous infusion of Ang II at the same dose in the presence of L-NAME decreased MBF by 23% and medullary PO2 by 28%, but it had no effect on cortical blood flow or arterial blood pressure. An in vivo microdialysis-oxyhemoglobin NO trapping technique was used in other rats to determine tissue NO concentrations using the same protocol. Ang II infusion increased tissue NO concentrations by 85% in the renal cortex and 150% in the renal medulla. Renal medullary interstitial infusion of L-NAME (1.4 microg/kg per minute) reduced medullary NO concentrations and substantially blocked Ang II-induced increases in NO concentrations in the renal medulla, but not in the renal cortex. Tissue slices of the renal cortex and medulla were studied to determine the effects of Ang II and L-NAME on the nitrite/nitrate production. Ang II stimulated the nitrite/nitrate production predominately in the renal medulla, which was significantly attenuated by L-NAME. We conclude that small elevations of circulating Ang II levels increase medullary NO production and concentrations, which plays an important role in buffering the vasoconstrictor effects of this peptide and in maintaining a constancy of MBF.

  13. Medullary infarcts may cause ipsilateral masseter reflex abnormalities.

    PubMed

    Thömke, Frank; Marx, Jürgen J; Cruccu, Giorgio; Stoeter, Peter; Hopf, Hanns C

    2007-10-01

    There is a suprasegmental influence on the masseter reflex (MassR) in animals, which is mediated via the fifth nerve spinal nucleus (5SpN). Corresponding data in humans are lacking. Out of 268 prospectively recruited patients with clinical signs of acute brainstem infarctions, we identified 38 with magnetic resonance imaging (MRI)-documented unilateral infarcts caudal to the levels of the fifth nerve motor and main sensory nuclei. All had biplanar T2- and echo planar diffusion-weighted MRI and MassR testing. Five patients (13%) had ipsilateral MassR abnormalities. In all, the infarcts involved the region of the 5SpN. Patients with medullary infarcts involving the region of the 5SpN may thus have ipsilateral MassR abnormalities. This possibly represents an interruption of an excitatory projection mediated via the 5SpN to masseter motoneurons in the fifth nerve motor nucleus. MassR abnormalities with medullary lesions restrict the topodiagnostic value of the MassR.

  14. Cytological aspects of melanotic variant of medullary thyroid carcinoma.

    PubMed

    de Lima, M A; Dias Medeiros, J; Rodrigues Da Cunha, L; de Cássia Caldas Pessôa, R; Silveira Tavares, F; de Fátima Borges, M; Marinho, E O

    2001-03-01

    We had the opportunity to examine a case of fine-needle aspiration (FNA) of a melanotic variant of medullary thyroid carcinoma (MTC) in a 20-yr-old man. The patient presented a single node, hardened and mobile upon deglutition, in the right lobe of the thyroid, for 9 mo, without symptoms of glandular dysfunction. Calcitonin (138 pg/ml), urinary calcium (177 mg/dl), and the carcinoembryonic antigen (341 ng/ml) were increased. The nodular aspirate, drawn by FNA, was represented by pleomorphic cells, with frequent intranuclear cytoplasmic inclusions, sometimes bi- or multinucleated, with abundant, finely granular cytoplasm, sometimes containing a brown pigment resembling melanin. An immunohistochemical study using monoclonal antibodies (Dako Corp., Carpinteria, CA) showed that the neoplastic cells were intensely and diffusely positive for calcitonin and chromogranin, and focally positive for HMB45. In view of these findings, the case was characterized as a melanotic variant of medullary carcinoma, a rare type of neoplasia, but having a prognosis similar to the classical variant of MTC.

  15. Secretion of Parathyroid Hormone in Patients with Medullary Thyroid Carcinoma

    PubMed Central

    Deftos, Leonard J.; Parthemore, Jacqueline G.

    1974-01-01

    The secretion of parathyroid hormone (PTH) and calcitonin (CT) was studied in 30 patients with medullary thyroid carcinoma. Most patients with elevated levels of CT were normocalcemic and also had normal basal levels of PTH. Five of six patients with associated hyperparathyroidism were hypercalcemic and had elevated basal PTH levels. Hormone secretion was also studied during infusions with standard and low doses of calcium. PTH unexpectedly increased during 12 of 18 calcium infusions. Such a paradoxical increase in PTH was seen in those patients with the greatest increase in CT and the least increase in calcium during the calcium infusion. Accordingly, increases in PTH concentration during the calcium infusions could be correlated directly with increases in CT and correlated inversely with increases in calcium. These observations suggest that, in some patients with medullary thyroid carcinoma, a further increase in the abnormally elevated CT levels may stimulate PTH secretion. Therefore, at least in acute studies, there may be a functional, as well as a genetic, relationship between the secretion of these two hormones in patients with this thyroid tumor. PMID:4847251

  16. Role of renal medullary adenosine in the control of blood flow and sodium excretion.

    PubMed

    Zou, A P; Nithipatikom, K; Li, P L; Cowley, A W

    1999-03-01

    This study determined the levels of adenosine in the renal medullary interstitium using microdialysis and fluorescence HPLC techniques and examined the role of endogenous adenosine in the control of medullary blood flow and sodium excretion by infusing the specific adenosine receptor antagonists or agonists into the renal medulla of anesthetized Sprague-Dawley rats. Renal cortical and medullary blood flows were measured using laser-Doppler flowmetry. Analysis of microdialyzed samples showed that the adenosine concentration in the renal medullary interstitial dialysate averaged 212 +/- 5.2 nM, which was significantly higher than 55.6 +/- 5.3 nM in the renal cortex (n = 9). Renal medullary interstitial infusion of a selective A1 antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; 300 pmol. kg-1. min-1, n = 8), did not alter renal blood flows, but increased urine flow by 37% and sodium excretion by 42%. In contrast, renal medullary infusion of the selective A2 receptor blocker 3, 7-dimethyl-1-propargylxanthine (DMPX; 150 pmol. kg-1. min-1, n = 9) decreased outer medullary blood flow (OMBF) by 28%, inner medullary blood flows (IMBF) by 21%, and sodium excretion by 35%. Renal medullary interstitial infusion of adenosine produced a dose-dependent increase in OMBF, IMBF, urine flow, and sodium excretion at doses from 3 to 300 pmol. kg-1. min-1 (n = 7). These effects of adenosine were markedly attenuated by the pretreatment of DMPX, but unaltered by DPCPX. Infusion of a selective A3 receptor agonist, N6-benzyl-5'-(N-ethylcarbonxamido)adenosine (300 pmol. kg-1. min-1, n = 6) into the renal medulla had no effect on medullary blood flows or renal function. Glomerular filtration rate and arterial pressure were not changed by medullary infusion of any drugs. Our results indicate that endogenous medullary adenosine at physiological concentrations serves to dilate medullary vessels via A2 receptors, resulting in a natriuretic response that overrides the tubular A1 receptor

  17. [A Case of Adenosquamous Carcinoma of the Ascending Colon].

    PubMed

    Hijikawa, Takeshi; Yoshida, Ryo; Yamada, Masanori; Nakatani, Kazuyoshi; Tokuhara, Katsuji; Kitade, Hiroaki; Shikata, Nobuaki; Yoshioka, Kazuhiko; Kon, Masanori

    2015-10-01

    We report a case of adenosquamous carcinoma of the colon. A 70-year-old woman underwent a colonoscopic examination because of a positive fecal occult blood test. Colonoscopy demonstrated a type 2 tumor of the ascending colon, and a biopsy specimen showed poorly-moderately differentiated tubular adenocarcinoma. We performed a right hemicolectomy with D2 lymphadenectomy. The histopathology of the tumor demonstrated adenosquamous adenocarcinoma. Primary adenosquamous carcinoma of the colon is relatively rare and has a poor prognosis. Therefore, adenosquamous carcinoma of the colon may require strict follow-up.

  18. Emergence of Spatial Stream Segregation in the Ascending Auditory Pathway

    PubMed Central

    Yao, Justin D.; Bremen, Peter

    2015-01-01

    Stream segregation enables a listener to disentangle multiple competing sequences of sounds. A recent study from our laboratory demonstrated that cortical neurons in anesthetized cats exhibit spatial stream segregation (SSS) by synchronizing preferentially to one of two sequences of noise bursts that alternate between two source locations. Here, we examine the emergence of SSS along the ascending auditory pathway. Extracellular recordings were made in anesthetized rats from the inferior colliculus (IC), the nucleus of the brachium of the IC (BIN), the medial geniculate body (MGB), and the primary auditory cortex (A1). Stimuli consisted of interleaved sequences of broadband noise bursts that alternated between two source locations. At stimulus presentation rates of 5 and 10 bursts per second, at which human listeners report robust SSS, neural SSS is weak in the central nucleus of the IC (ICC), it appears in the nucleus of the brachium of the IC (BIN) and in approximately two-thirds of neurons in the ventral MGB (MGBv), and is prominent throughout A1. The enhancement of SSS at the cortical level reflects both increased spatial sensitivity and increased forward suppression. We demonstrate that forward suppression in A1 does not result from synaptic inhibition at the cortical level. Instead, forward suppression might reflect synaptic depression in the thalamocortical projection. Together, our findings indicate that auditory streams are increasingly segregated along the ascending auditory pathway as distinct mutually synchronized neural populations. SIGNIFICANCE STATEMENT Listeners are capable of disentangling multiple competing sequences of sounds that originate from distinct sources. This stream segregation is aided by differences in spatial location between the sources. A possible substrate of spatial stream segregation (SSS) has been described in the auditory cortex, but the mechanisms leading to those cortical responses are unknown. Here, we investigated SSS in

  19. Penetrating injury of ascending aorta with arrow in situ.

    PubMed

    Lakhotia, Siddharth; Prakash, Shashi; Singh, Dinesh Kumar; Kumar, Ashok; Panigrahi, Debasish

    2012-04-01

    Penetrating injuries of the aorta are rare and highly lethal; very few patients are able to reach the hospital alive. We report a case of penetrating injury into the ascending aorta with the arrow still in situ, shot by a bow in a tribal region of India. The wound of entry into the aorta was sealed by the arrow itself. The patient came to us walking and supporting the arrow with his left hand. He was operated on, and the arrow was successfully removed from the aorta.

  20. Genetic Alterations in Medullary Thyroid Cancer: Diagnostic and Prognostic Markers

    PubMed Central

    A, Taccaliti; F, Silvetti; G, Palmonella; M, Boscaro

    2011-01-01

    Medullary thyroid carcinoma (MTC) is a rare calcitonin producing neuroendocrine tumour that originates from the parafollicular C-cells of the thyroid gland. The RET proto-oncogene encodes the RET receptor tyrosine kinase, with consequently essential roles in cell survival, differentiation and proliferation. Somatic or germline mutations of the RET gene play an important role in this neoplasm in development of sporadic and familial forms, respectively. Genetic diagnosis has an important role in differentiating sporadic from familiar MTC. Furthermore, depending on the location of the mutation, patients can be classified into risk classes. Therefore, genetic screening of the RET gene plays a critical role not only in diagnosis but also in assessing the prognosis and course of MTC. PMID:22654561

  1. 2012 European Thyroid Association Guidelines for Metastatic Medullary Thyroid Cancer

    PubMed Central

    Schlumberger, M.; Bastholt, L.; Dralle, H.; Jarzab, B.; Pacini, F.; Smit, J.W.A.

    2012-01-01

    Distant metastases are the main cause of death in patients with medullary thyroid cancer (MTC). These 21 recommendations focus on MTC patients with distant metastases and a detailed follow-up protocol of patients with biochemical or imaging evidence of disease, selection criteria for treatment, and treatment modalities, including local and systemic treatments based on the results of recent trials. Asymptomatic patients with low tumor burden and stable disease may benefit from local treatment modalities and can be followed up at regular intervals of time. Imaging is usually performed every 6–12 months, or at longer intervals of time depending on the doubling times of serum calcitonin and carcinoembryonic antigen levels. Patients with symptoms, large tumor burden and progression on imaging should receive systemic treatment. Indeed, major progress has recently been achieved with novel targeted therapies using kinase inhibitors directed against RET and VEGFR, but further research is needed to improve the outcome of these patients. PMID:24782992

  2. Medullary thyroid carcinoma with ectopic adrenocorticotropic hormone syndrome.

    PubMed

    Choi, Hong Seok; Kim, Min Joo; Moon, Chae Ho; Yoon, Jong Ho; Ku, Ha Ra; Kang, Geon Wook; Na, Im Il; Lee, Seung-Sook; Lee, Byung-Chul; Park, Young Joo; Kim, Hong Il; Ku, Yun Hyi

    2014-03-01

    Ectopic adrenocorticotropic hormone (ACTH) syndrome is caused most frequently by a bronchial carcinoid tumor or by small cell lung cancer. Medullary thyroid carcinoma (MTC) is a rare etiology of ectopic ACTH syndrome. We describe a case of Cushing syndrome due to ectopic ACTH production from MTC in a 48-year-old male. He was diagnosed with MTC 14 years ago and underwent total thyroidectomy, cervical lymph node dissection and a series of metastasectomies. MTC was confirmed by the pathological examination of the thyroid and metastatic mediastinal lymph node tissues. Two years after his last surgery, he developed Cushingoid features, such as moon face and central obesity, accompanied by uncontrolled hypertension and new-onset diabetes. The laboratory results were compatible with ectopic ACTH syndrome. A bilateral adrenalectomy improved the clinical and laboratory findings that were associated with Cushing syndrome. This is the first confirmed case of ectopic ACTH syndrome caused by MTC in Korea.

  3. Treating medullary thyroid cancer in the age of targeted therapy

    PubMed Central

    Cabanillas, Maria E; Hu, Mimi I; Jimenez, Camilo; Grubbs, Elizabeth G; Cote, Gilbert J

    2015-01-01

    Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor deriving from the thyroid parafollicular cell. Thyroidectomy continues to serve as the primary initial treatment for this cancer. Because standard cytotoxic chemotherapy has proven ineffective, reoperation and external beam radiation therapy had been the only tools to treat recurrences or distant disease. The discovery that aberrant activation of RET, a receptor tyrosine kinase, is a primary driver of MTC tumorigenesis led to clinical trials using RET-targeting tyrosine kinase inhibitors. The successes of those trials led to the approval of vandetanib and cabozantinib for treating patients with progressive or symptomatic MTC. The availability of these drugs, along with additional targeted therapies in development, requires a thoughtful reconsideration of the approach to treating patients with unresectable locally advanced and/or metastatic progressive MTC. PMID:25908961

  4. Medullary Sponge Kidney and Urinary Calculi Aeromedical Concerns

    NASA Technical Reports Server (NTRS)

    Jones, Jeffrey A.; Cherian, Sebastian F.; Barr, Yael R.; Stocco, Amber

    2008-01-01

    Medullary Sponge Kidney (MSK) is a benign disorder associated with renal stones in 60% of patients. Patients frequently have episodic painless hematuria but are otherwise asymptomatic unless renal calculi or infections complicate the disease. Nephrolithiasis is a relative, but frequently enforced, contraindication to space or other high performance flight. Two case reports of asymptomatic NASA flight crew with MSK and three cases of military aviators diagnosed with MSK are reviewed, all cases resulted in waiver and return to flight status after treatment and a vigorous follow up and prophylaxis protocol. MSK in aviation and space flight necessitates a highly case-by-case dependent evaluation and treatment process to rule out other potential confounding factors that might also contribute to stone formation and in order to re-qualify the aviator for flight duties.

  5. Pain and neuroma formation in Wallenberg's lateral medullary syndrome.

    PubMed

    Moffie, D; Hamburger, H L

    1986-01-01

    We report a patient with a Wallenberg's lateral medullary syndrome in which pain was a prominent feature. This led to substitution of the original and correct diagnosis by that of a thalamic syndrome for which a prefrontal leucotomy was performed. The patient died some years later from a myocardial infarction and autopsy was performed. In the dorsolateral part of the medulla oblongata a cavity was found in which aberrant nerve fibres with neuroma-like formations could be seen. These fibres coursed along blood vessels, and penetrated from the surface of the medulla oblongata. On the base of the clinico-pathological correlations, it is conjectured that destruction of the lateral reticular formation cannot be the sole cause of the severe pain.

  6. [Biomechanical analysis of the medullary bone nail and its locking].

    PubMed

    Teubner, E

    1985-07-01

    By mechanical definition an intramedullary nail is not a nail but rather a bendable feather, subject to longitudinal tension and to a lesser degree to transverse pressure. Reaming the medullary canal is necessary for centralization of the nail as well as to increase the area of contact with the bone. However, this procedure is detrimental to the bone metabolism and reduces its elasticity against torsional forces. The dynamic locking nail-system is more biologic than conventional nailing and it reduces rotatory instability with the help of additional components, such as transverse screws. Only static locking allows true static weight bearing with crutches, but not dynamic mobilisation. Nails with conventional strength and in leaf of trefoil formation are superior to other designs. However, an improved angle in the proximal locking is suggested, as this would allow for a three to four times greater weight bearing.

  7. Lateral medullary stroke in patient with granulomatous polyangiitis.

    PubMed

    Taraschenko, Olga D; Amory, Colum F; Waldman, Jonathan; Hanspal, Era K; Bernardini, Gary L

    2014-01-01

    Granulomatous polyangiitis (GPA), also known as Wegener granulomatosis, is a systemic antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis that infrequently affects the central nervous system. We report a 41-year-old man with lateral medullary infarction who developed rapidly progressive renal failure. He was diagnosed with GPA based on positive serum c-ANCA and antiproteinase 3 antibodies and demonstration of pauci-immune crescentic glomerulonephritis on kidney biopsy. He was treated with Coumadin, pulse steroids, cyclophosphamide, and plasmapheresis. He had resolution of his neurologic deficits and improvement in renal function. This case report highlights the importance to consider GPA vasculitis in the differential diagnosis of stroke in patients with development of acute kidney injury.

  8. Ascending connections to the forebrain in the Tegu lizard.

    PubMed

    Lohman, A H; van Woerden-Verkley, I

    1978-12-01

    The ascending connections to the striatum and the cortex of the Tegu lizard, Tupinambis nigropunctatus, were studied by means of anterograde fiber degeneration and retrograde axonal transport. The striatum receives projections by way of the dorsal peduncle of the lateral forebrain bundle from four dorsal thalamic nuclei: nucleus rotundus, nucleus reuniens, the posterior part of the dorsal lateral geniculate nucleus and nucleus dorsomedialis. The former three nuclei project to circumscribed areas of the dorsal striatum, whereas nucleus dorsomedialis has a distribution to the whole dorsal striatum. Other sources of origin to the striatum are the mesencephalic reticular formation, substantia nigra and nucleus cerebelli lateralis. With the exception of the latter afferentation all these projections are ipsilateral. The ascending connections to the pallium originate for the major part from nucleus dorsolateralis anterior of the dorsal thalamus. The fibers course in both the medial forebrain bundle and the dorsal peduncle of the lateral forebrain bundle and terminate ipsilaterally in the middle of the molecular layer of the small-celled part of the mediodorsal cortex and bilaterally above the intermediate region of the dorsal cortex. The latter area is reached also by fibers from the septal area. The large-celled part of the mediodorsal cortex receives projections from nucleus raphes superior and the corpus mammillare.

  9. Long Term Mean Local Time of the Ascending Node Prediction

    NASA Technical Reports Server (NTRS)

    McKinley, David P.

    2007-01-01

    Significant error has been observed in the long term prediction of the Mean Local Time of the Ascending Node on the Aqua spacecraft. This error of approximately 90 seconds over a two year prediction is a complication in planning and timing of maneuvers for all members of the Earth Observing System Afternoon Constellation, which use Aqua's MLTAN as the reference for their inclination maneuvers. It was determined that the source of the prediction error was the lack of a solid Earth tide model in the operational force models. The Love Model of the solid Earth tide potential was used to derive analytic corrections to the inclination and right ascension of the ascending node of Aqua's Sun-synchronous orbit. Additionally, it was determined that the resonance between the Sun and orbit plane of the Sun-synchronous orbit is the primary driver of this error. The analytic corrections have been added to the operational force models for the Aqua spacecraft reducing the two-year 90-second error to less than 7 seconds.

  10. Bioluminescence imaging of Chlamydia muridarum ascending infection in mice.

    PubMed

    Campbell, Jessica; Huang, Yumeng; Liu, Yuanjun; Schenken, Robert; Arulanandam, Bernard; Zhong, Guangming

    2014-01-01

    Chlamydial pathogenicity in the upper genital tract relies on chlamydial ascending from the lower genital tract. To monitor chlamydial ascension, we engineered a luciferase-expressing C. muridarum. In cells infected with the luciferase-expressing C. muridarum, luciferase gene expression and enzymatic activity (measured as bioluminescence intensity) correlated well along the infection course, suggesting that bioluminescence can be used for monitoring chlamydial replication. Following an intravaginal inoculation with the luciferase-expressing C. muridarum, 8 of 10 mice displayed bioluminescence signal in the lower with 4 also in the upper genital tracts on day 3 after infection. By day 7, all 10 mice developed bioluminescence signal in the upper genital tracts. The bioluminescence signal was maintained in the upper genital tract in 6 and 2 mice by days 14 and 21, respectively. The bioluminescence signal was no longer detectable in any of the mice by day 28. The whole body imaging approach also revealed an unexpected airway infection following the intravaginal inoculation. Although the concomitant airway infection was transient and did not significantly alter the genital tract infection time courses, caution should be taken during data interpretation. The above observations have demonstrated that C. muridarum can not only achieve rapid ascending infection in the genital tract but also cause airway infection following a genital tract inoculation. These findings have laid a foundation for further optimizing the C. muridarum intravaginal infection murine model for understanding chlamydial pathogenic mechanisms.

  11. FTIR protein secondary structure analysis of human ascending aortic tissues.

    PubMed

    Bonnier, Franck; Rubin, Sylvain; Debelle, Laurent; Ventéo, Lydie; Pluot, Michel; Baehrel, Bernard; Manfait, Michel; Sockalingum, Ganesh D

    2008-08-01

    The advent of moderate dilatations in ascending aortas is often accompanied by structural modifications of the main components of the aortic tissue, elastin and collagen. In this study, we have undertaken an approach based on FTIR microscopy coupled to a curve-fitting procedure to analyze secondary structure modifications in these proteins in human normal and pathological aortic tissues. We found that the outcome of the aortic pathology is strongly influenced by these proteins, which are abundant in the media of the aortic wall, and that the advent of an aortic dilatation is generally accompanied by a decrease of parallel beta-sheet structures. Elastin, essentially composed of beta-sheet structures, seems to be directly related to these changes and therefore indicative of the elastic alteration of the aortic wall. Conventional microscopy and confocal fluorescence microscopy were used to compare FTIR microscopy results with the organization of the elastic fibers present in the tissues. This in-vitro study on 6 patients (three normal and three pathologic), suggests that such a spectroscopic marker, specific to aneurismal tissue characterization, could be important information for surgeons who face the dilemma of moderate aortic tissue dilatation of the ascending aortas.

  12. Metastasis to the appendix from adenocarcinoma of the ascending colon

    PubMed Central

    Li, Yingjie; Li, Mingshan; Li, Xiaoxia; Sang, Haiquan

    2017-01-01

    Abstract Rationale: Metastasis of cancer cells involves shedding from the primary tumor through various means to distant tissues and organs with continued growth and formation of new metastatic tumors of the same cancer type as the original tumor. The common sites for colon cancer metastases include the pelvis, retroperitoneal lymph nodes, liver, and lungs; Colon cancer metastases to the appendix are rare, as reported in this case. Patient concerns and diagnoses: A 45-year-old man was admitted to our department with a 24-hour history of abdominal distension and incomplete obstruction. Colonoscopy showed an elevated lesion in the ascending colon and the pathologic diagnosis was adenocarcinoma. Interventions and outcomes: This patient underwent a radical right hemi-colectomy. The post-operative pathologic examination revealed metastatic adenocarcinoma in all layers of the appendix, especially the muscularis mucosae. The diagnosis was adenocarcinoma of the ascending colon (pT4bN2bM0 stage IIIC) with metastatic adenocarcinoma of the appendix. Lessons: An absent right colic artery with lymph node fusion might increase the risk of appendiceal cancer metastasis. PMID:28296772

  13. Observing System Simulations for ASCENDS: Synthesizing Science Measurement Requirements (Invited)

    NASA Astrophysics Data System (ADS)

    Kawa, S. R.; Baker, D. F.; Schuh, A. E.; Crowell, S.; Rayner, P. J.; Hammerling, D.; Michalak, A. M.; Wang, J. S.; Eluszkiewicz, J.; Ott, L.; Zaccheo, T.; Abshire, J. B.; Browell, E. V.; Moore, B.; Crisp, D.

    2013-12-01

    The measurement of atmospheric CO2 from space using active (lidar) sensing techniques has several potentially significant advantages in comparison to current and planned passive CO2 instruments. Application of this new technology aims to advance CO2 measurement capability and carbon cycle science into the next decade. The NASA Active Sensing of Carbon Emissions, Nights, Days, and Seasons (ASCENDS) mission has been recommended by the US National Academy of Sciences Decadal Survey for the next generation of space-based CO2 observing systems. ASCENDS is currently planned for launch in 2022. Several possible lidar instrument approaches have been demonstrated in airborne campaigns and the results indicate that such sensors are quite feasible. Studies are now underway to evaluate performance requirements for space mission implementation. Satellite CO2 observations must be highly precise and unbiased in order to accurately infer global carbon source/sink fluxes. Measurement demands are likely to further increase in the wake of GOSAT, OCO-2, and enhanced ground-based in situ and remote sensing CO2 data. The objective of our work is to quantitatively and consistently evaluate the measurement capabilities and requirements for ASCENDS in the context of advancing our knowledge of carbon flux distributions and their dependence on underlying physical processes. Considerations include requirements for precision, relative accuracy, spatial/temporal coverage and resolution, vertical information content, interferences, and possibly the tradeoffs among these parameters, while at the same time framing a mission that can be implemented within a constrained budget. Here, we attempt to synthesize the results of observing system simulation studies, commissioned by the ASCENDS Science Requirements Definition Team, into a coherent set of mission performance guidelines. A variety of forward and inverse model frameworks are employed to reduce the potential dependence of the results on model

  14. Kidney Involvement in Systemic Calcitonin Amyloidosis Associated With Medullary Thyroid Carcinoma.

    PubMed

    Koopman, Timco; Niedlich-den Herder, Cindy; Stegeman, Coen A; Links, Thera P; Bijzet, Johan; Hazenberg, Bouke P C; Diepstra, Arjan

    2017-04-01

    A 52-year-old woman with widely disseminated medullary thyroid carcinoma developed nephrotic syndrome and slowly decreasing kidney function. A kidney biopsy was performed to differentiate between malignancy-associated membranous glomerulopathy and tyrosine kinase inhibitor-induced focal segmental glomerulosclerosis. Surprisingly, the biopsy specimen revealed diffuse glomerular deposition of amyloid that was proved to be derived from the calcitonin hormone (Acal), produced by the medullary thyroid carcinoma. This amyloid was also present in an abdominal fat pad biopsy. Although local ACal deposition is a characteristic feature of medullary thyroid carcinoma, the systemic amyloidosis involving the kidney that is presented in this case report has not to our knowledge been described previously and may be the result of long-term high plasma calcitonin levels. Our case illustrates that systemic calcitonin amyloidosis should be considered in the differential diagnosis of proteinuria in patients with medullary thyroid carcinoma.

  15. Fenestration of the superior medullary velum as treatment for a trapped fourth ventricle: a feasibility study.

    PubMed

    Tubbs, R Shane; Wellons, John C; Salter, George; Oakes, W Jerry

    2004-03-01

    We developed a novel approach for fenestration of the trapped fourth ventricle utilizing the superior medullary velum (valve of Vieussens). Trapped fourth ventricles, which are seen often in the pediatric hydrocephalic population, are troublesome entities surgically. A right burr hole was carried out in 10 adult cadavers with no gross intracranial pathology and the superior medullary velum was fenestrated to the quadrigeminal cistern with the aid of an endoscope. This technique was carried out easily in all cadaveric specimens. With endoscopy, no vascular insult was appreciated either before or after fenestration of the superior medullary velum. These preliminary findings demonstrate that fenestration of the superior medullary velum may provide a good alternative to the present therapy of shunting trapped fourth ventricles, a therapy wrought with complications.

  16. Total lymphoid irradiation leads to transient depletion of the mouse thymic medulla and persistent abnormalities among medullary stromal cells

    SciTech Connect

    Adkins, B.; Gandour, D.; Strober, S.; Weissman, I.

    1988-05-15

    Mice given multiple doses of sublethal irradiation to both the thymus and the peripheral lymphoid tissues showed major transient, and some persistent disruptions in general thymic architecture and in thymic stromal components. At 2 wk after total lymphoid irradiation (TLI), the thymus lacked identifiable medullary regions by immunohistochemical analyses. Medullary stromal cells expression MHC Ag or a medullary epithelial cell Ag, as well as medullary macrophages, were undetectable. Instead, the processes of cortical epithelial cells were observed throughout the entire thymus. Strikingly, thymocyte subsets with mature phenotypes (CD4+CD8- and CD4-CD8+) were present in the apparent absence of a medulla. This early, gross effect was rapidly reversed such that by 1 to 2 mo after TLI, medullary areas with MHC Ag-positive cells were evident. However, abnormalities in a subset of medullary stromal cells appeared to be more persistent. Medullary epithelial cells, identified by the MD1 mAb, were greatly reduced in number and abnormally organized for at least 4 mo after TLI. In addition, macrophages containing endogenous peroxidase activity, normally abundant in medullary regions, were undetectable at all times examined after TLI. Therefore, this irradiation regimen induced both transient and long term effects in the thymus, primarily in medullary regions. These results suggest that TLI may be used as an experimental tool for studying the impact of selective depletion of medullary stromal cells on the development of specific T cell functions.

  17. Medullary thyroid carcinoma metastatic to the pituitary gland: an unusual site of metastasis.

    PubMed

    Williams, Michelle D; Asa, Sylvia L; Fuller, Gregory N

    2008-06-01

    We present a case of metastatic medullary thyroid carcinoma involving the pituitary gland of a 23-year-old woman with multiple endocrine neoplasia type 2b who presented with diabetes insipidus and visual loss. The diagnostic features, including cytomorphology and immunohistochemistry, used to differentiate pituitary adenoma from metastatic medullary carcinoma are discussed. Pituitary metastases and tumor-to-tumor metastases in this region are also highlighted.

  18. Failure of pentagastrin-stimulated calcitonin testing in early manifestation of familial medullary thyroid cancer.

    PubMed

    Pirich, Christian; Rendl, Gundula; Hauser-Kronberger, Cornelia; Häusler, Ingrid

    2012-10-01

    This case report describes three generations of a family with familial medullary thyroid cancer (RET gene mutation L790F). One of the three siblings-all of them carrier of the respective mutation-exhibited the absence of pathological basal and pentagastrin-stimulated calcitonin levels in spite of multifocal medullary thyroid microcancer. This case illustrates the challenge to consider the biological diversity of RET gene mutations in the clinical management of affected gene carriers.

  19. An overview of NASA's ASCENDS Mission's Lidar Measurement Requirements

    NASA Astrophysics Data System (ADS)

    Abshire, J. B.; Browell, E. V.; Menzies, R. T.; Lin, B.; Spiers, G. D.; Ismail, S.

    2014-12-01

    The objectives of NASA's ASCENDS mission are to improve the knowledge of global CO2 sources and sinks by precisely measuring the tropospheric column abundance of atmospheric CO2 and O2. The mission will use a continuously operating nadir-pointed integrated path differential absorption (IPDA) lidar in a polar orbit. The lidar offers a number of important new capabilities and will measure atmospheric CO2 globally over a wide range of challenging conditions, including at night, at high latitudes, through hazy and thin cloud conditions, and to cloud tops. The laser source enables a measurement of range, so that the absorption path length to the scattering surface will be always accurately known. The lidar approach also measures consistently in a nadir-zenith path and the narrow laser linewidth allows weighting the measurement to the lower troposphere. Using these measurements with atmospheric and flux models will allow improved estimates of CO2 fluxes and hence better understanding of the processes that exchange CO2 between the surface and atmosphere. The ASCENDS formulation team has developed a preliminary set of requirements for the lidar measurements. These were developed based on experience gained from the numerous ASCENDS airborne campaigns that have used different candidate lidar measurement techniques. They also take into account the complexity of making precise measurement of atmospheric gas columns when viewing the Earth from space. Some of the complicating factors are the widely varying reflectance and topographic heights of the Earth's land and ocean surfaces, the variety of cloud types, and the degree of cloud and aerosol absorption and scattering in the atmosphere. The requirements address the precision and bias in the measured column mixing ratio, the dynamic range of the expected surface reflected signal, the along-track sampling resolution, measurements made through thin clouds, measurements to forested and slope surfaces, range precision, measurements

  20. Decreased GABAA receptor binding in the medullary serotonergic system in the sudden infant death syndrome.

    PubMed

    Broadbelt, Kevin G; Paterson, David S; Belliveau, Richard A; Trachtenberg, Felicia L; Haas, Elisabeth A; Stanley, Christina; Krous, Henry F; Kinney, Hannah C

    2011-09-01

    γ-Aminobutyric acid (GABA) neurons in the medulla oblongata help regulate homeostasis, in part through interactions with the medullary serotonergic (5-HT) system. Previously, we reported abnormalities in multiple 5-HT markers in the medullary 5-HT system of infants dying from sudden infant death syndrome (SIDS), suggesting that 5-HT dysfunction is involved in its pathogenesis. Here, we tested the hypothesis that markers of GABAA receptors are decreased in the medullary 5-HT system in SIDS cases compared with controls. Using tissue receptor autoradiography with the radioligand H-GABA, we found 25% to 52% reductions in GABAA receptor binding density in 7 of 10 key nuclei sampled of the medullary 5-HT system in the SIDS cases (postconceptional age [PCA] = 51.7 ± 8.3, n = 28) versus age-adjusted controls (PCA = 55.3 ± 13.5, n = 8) (p ≤ 0.04). By Western blotting, there was 46.2% reduction in GABAAα3 subunit levels in the gigantocellularis (component of the medullary 5-HT system) of SIDS cases (PCA = 53.9 ± 8.4, n = 24) versus controls (PCA = 55.3 ± 8.3, n = 8) (56.8% standard in SIDS cases vs 99.35% in controls; p = 0.026). These data suggest that medullary GABAA receptors are abnormal in SIDS infants and that SIDS is a complex disorder of a homeostatic network in the medulla that involves deficits of the GABAergic and 5-HT systems.

  1. Do egg-laying crocodilian (Alligator mississippiensis) archosaurs form medullary bone?

    PubMed

    Schweitzer, M H; Elsey, R M; Dacke, C G; Horner, J R; Lamm, E-T

    2007-04-01

    It is beyond question that Mesozoic dinosaurs, like Aves and Crocodylia, are archosaurs. However, within the archosaurian clade, the origin and distribution of some major features are less clear, particularly with respect to reproductive physiology. Medullary bone, a highly mineralized, bony reproductive tissue present in the endosteal cavities of all extant egg-laying birds thus far examined, has recently been reported in Tyrannosaurus rex. Its presence or absence in extant crocodilians, therefore, may shed light on the timing of its evolutionary appearance. If medullary bone is present in all three taxa, it arose before the three lineages diverged. However, if medullary bone arose after this divergence, it may be present in both extinct dinosaurs and birds, or in birds only. If present in extinct dinosaurs and birds, but not crocodilians, it would indicate that it arose in the common ancestor of this clade, thus adding support to the closer phylogenetic relationship of dinosaurs and birds relative to crocodilians. Thus, the question of whether the crocodilian Alligator mississippiensis forms medullary bone during the production of eggs has important evolutionary significance. Our examination of long bones from several alligators (two alligators with eggs in the oviducts, one that had produced eggs in the past but was not currently in reproductive phase, an immature female and an adult male) shows no differences on the endosteal surfaces of the long bones, and no evidence of medullary bone, supporting the hypothesis that medullary bone first evolved in the dinosaur-bird line, after the divergence of crocodilians from this lineage.

  2. Two-dimensional Fourier analysis of the spongy medullary keratin of structurally coloured feather barbs

    PubMed Central

    Prum, R. O.; Torres, R.; Williamson, S.; Dyck, J.

    1999-01-01

    We conducted two-dimensional (2D) discrete Fourier analyses of the spatial variation in refractive index of the spongy medullary keratin from four different colours of structurally coloured feather barbs from three species of bird: the rose-faced lovebird, Agapornis roseicollis (Psittacidae), the budgerigar, Melopsittacus undulatus (Psittacidae), and the Gouldian finch, Poephila guttata (Estrildidae). These results indicate that the spongy medullary keratin is a nanostructured tissue that functions as an array of coherent scatterers. The nanostructure of the medullary keratin is nearly uniform in all directions. The largest Fourier components of spatial variation in refractive index in the tissue are of the appropriate size to produce the observed colours by constructive interference alone. The peaks of the predicted reflectance spectra calculated from the 2D Fourier power spectra are congruent with the reflectance spectra measured by using microspectrophotometry. The alternative physical models for the production of these colours, the Rayleigh and Mie theories, hypothesize that medullary keratin is an incoherent array and that scattered waves are independent in phase. This assumption is falsified by the ring-like Fourier power spectra of these feathers, and the spacing of the scattering air vacuoles in the medullary keratin. Structural colours of avian feather barbs are produced by constructive interference of coherently scattered light waves from the optically heterogeneous matrix of keratin and air in the spongy medullary layer.

  3. Numerical Study on 4-1 Coal Seam of Xiaoming Mine in Ascending Mining

    PubMed Central

    Tianwei, Lan; Hongwei, Zhang; Sheng, Li; Weihua, Song; Batugin, A. C.; Guoshui, Tang

    2015-01-01

    Coal seams ascending mining technology is very significant, since it influences the safety production and the liberation of dull coal, speeds up the construction of energy, improves the stability of stope, and reduces or avoids deep hard rock mining induced mine disaster. Combined with the Xiaoming ascending mining mine 4-1, by numerical calculation, the paper analyses ascending mining 4-1 factors, determines the feasibility of ascending mining 4-1 coalbed, and proposes roadway layout program about working face, which has broad economic and social benefits. PMID:25866840

  4. [A case of adenosquamous carcinoma of the ascending colon].

    PubMed

    Toyoda, Tetsutaka; Nishimura, Yoji; Yatsuoka, Toshimasa; Yokoyama, Yasuyuki; Shimada, Ryu; Ishikawa, Hideki; Fukuda, Takashi; Amikura, Katsumi; Kawashima, Yoshiyuki; Sakamoto, Hirohiko; Tanaka, Yoichi; Nishimura, Yu

    2014-11-01

    A 6 8-year-old man was admitted to our hospital with lower abdominal pain. Lower gastrointestinal endoscopy showed type 2 advanced cancer in the ascending colon. Histopathological examination after endoscopical biopsy revealed both moderately differentiated adenocarcinoma and well-differentiated squamous carcinoma. Subsequently, right hemicolectomy was performed. The tumor was 55 × 40 mm in size and was diagnosed as an adenosquamous carcinoma A, type 2, pSS, pN0, sH0, sP0, sM0, fStageII. Adenosquamous carcinoma is extremely rare, represents about 0.1% of all colorectal cancer, and usually has a poor prognosis. Thirty-one months after surgery, the patient is still in good health and displays no signs of recurrence.

  5. Ascending infection of foot tendons in diabetic patients.

    PubMed

    Mismar, Ayman; Yousef, Mohammad; Badran, Darwish; Younes, Nidal

    2013-12-01

    Bone and soft tissue infection in the foot of diabetic patients is a well-described issue in the literature. A sound anatomical knowledge of the foot anatomy and compartments is mandatory to understand the mechanisms of infection spread. We describe four cases of diabetic foot infection complicated by long ascending infection. All did not respond initially to antibiotic treatment and the usual surgical debridement and were cured only after excision of the infected tendons. We highlight a rare but serious complication of the diabetic foot disease not commonly seen by the surgical community. We hope that this report raises the awareness of this condition so that a prompt diagnosis is made and appropriate treatment started, thereby reducing the risk of major lower limb amputations.

  6. Ascending aortic aneurysm in a patient with mixed gonadal dysgenesis.

    PubMed

    Bakoto, N; Corman, V; Legros, J J

    2011-02-01

    Cardiovascular and endocrine complications in male or sexually-ambiguous patients carrying a 45,X/46,XY mosaicism are rarely discussed in the medical literature. However, young female patients with a diagnosis of Turner's disease usually benefit from regular cardiologic and endocrine follow-up, in accordance with current international guidelines. We report the case of a male patient, aged 23 years, with an ambiguous phenotype known to harbor a mixed gonadic 45,X/46,XY type dysgenesis. The patient was admitted to the cardiology ward for investigation and management of cardiac failure secondary to both a biscupid aortic valve and ascending aorta aneurysm. This case report, and the few others, which have been previously reported in the literature, emphasizes the importance of cardiologic and endocrine follow-up in male carriers of 45,X/46,XY mosaicism.

  7. Certain implementative applications of Separate Node Ascending Derivatives Expansion (SNADE)

    NASA Astrophysics Data System (ADS)

    Bodur, Derya; Demiralp, Metin

    2017-01-01

    In this work we have focused on a very recently developed method called as Separate Node Ascending Derivatives Expansion (SNADE). SNADE can be considered as an infinite interpolation like Taylor Series Expansion. A Taylor Series is an infinite sum representation whose terms are calculated from the values of the functions derivatives at a single point. This newly proposed method involves denumerable infinitely many nodes in contrast to Taylor Series Expansion. SNADE is based on derivative integration formula for a univariate function. Integral of derivative identity is not only required to be used for the target function but repetitiously for its all derivatives. It may not be required to be used in the same interval. In addition to all these, each derivative value becomes evaluated at a different independent variable value. This work is designed to emphasize on the methods interpolatory nature. For this purpose certain implementation results are given and compared with well-known interpolation methods.

  8. An oxygen enrichment device for lowlanders ascending to high altitude

    PubMed Central

    2013-01-01

    Background When ascending to the high altitude, people living in low altitude areas will suffer from acute mountain sickness. The aim of this study is to test the hypothesis that whether an oxygen concentration membrane can be made and used to construct a new portable oxygen enrichment device for individuals in acute exposure to the high altitude. Methods The membrane was fabricated using vinylsiloxane rubber, polyphenylene oxide hydrogen silicone polymers, chloroplatinic acid and isopropyl alcohol. The membrane was assembled in a frame and the performance was tested in terms of concentration of oxygen, flow rate of oxygen enriched air, pressure ratio across the membrane and ambient temperature. Furthermore, the oxygen concentration device was constructed using the membrane, a DC fan, vacuum pump and gas buffer. A nonrandomized preliminary field test was conducted, in which eight healthy male subjects were flown to Tibet (Lhasa, 3,700 m). First, subjects wore the oxygen enrichment device and performed an incremental exercise on cycle ergometer. The test included heart rate (HR), saturation of peripheral oxygen (SpO2) and physical work capacity (PWC). Then, after a rest period of 4 hours, the experimental protocol was repeated without oxygen enrichment device. Results The testing showed that the membrane could increase the oxygen concentration by up to 30%. Simulation test indicated that although the performance of the oxygen enrichment device decreased with altitudes, the oxygen concentration could still maintain 28% with flow rate of enriched air 110 cm3/s at 5000 m. The field test showed that higher SpO2, lower HR, and better PWC (measured by the PWC-170) were observed from all the subjects using oxygen enrichment device compared with non-using (P < 0.01). Conclusions We concluded that the new portable oxygen enrichment device would be effective in improving exercise performance when ascending to the high altitude. PMID:24103365

  9. Ascending aortic wall cohesion: comparison of bicuspid and tricuspid valves.

    PubMed

    Benedik, Jaroslav; Pilarczyk, Kevin; Wendt, Daniel; Indruch, Jiri; Flek, Radek; Tsagakis, Konstantinos; Alaeddine, Savvas; Jakob, Heinz

    2012-01-01

    Objectives. Bicuspid aortic valve (AV) represents the most common form of congenital AV malformation, which is frequently associated with pathologies of the ascending aorta. We compared the mechanical properties of the aortic wall between patients with bicuspid and tricuspid AV using a new custom-made device mimicking transversal aortic wall shear stress. Methods. Between 03/2010 and 07/2011, 190 consecutive patients undergoing open aortic valve replacement at our institution were prospectively enrolled, presenting either with a bicuspid (group 1, n = 44) or a tricuspid (group 2, n = 146) AV. Aortic wall specimen were examined with the "dissectometer" resulting in nine specific aortic-wall parameters derived from tensile strength curves (TSC). Results. Patients with a bicuspid AV showed significantly more calcified valves (43.2% versus 15.8%, P < 0.001), and a significantly thinner aortic wall (2.04 ± 0.42 mm versus 2.24 ± 0.41 mm, P = 0.008). Transesophageal echocardiography diameters (annulus, aortic sinuses, and sinotubular junction) were significantly larger in the bicuspid group (P = 0.003, P = 0.02, P = 0.01). We found no difference in the aortic wall cohesion between both groups as revealed by shear stress testing (P = 0.72, P = 0.40, P = 0.41). Conclusion. We observed no differences of TSC in patients presenting with tricuspid or bicuspid AVs. These results may allow us to assume that the morphology of the AV and the pathology of the ascending aorta are independent.

  10. Advanced IMCW Lidar Techniques for ASCENDS CO2 Column Measurements

    NASA Astrophysics Data System (ADS)

    Campbell, Joel; lin, bing; nehrir, amin; harrison, fenton; obland, michael

    2015-04-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation.

  11. Differentiating the undifferentiated: immunohistochemical profile of medullary carcinoma of the colon with an emphasis on intestinal differentiation.

    PubMed

    Winn, Brody; Tavares, Rosemarie; Fanion, Jacqueline; Noble, Lelia; Gao, John; Sabo, Edmond; Resnick, Murray B

    2009-03-01

    Undifferentiated or medullary carcinoma is characterized by its distinct histologic appearance and relatively better prognosis compared to poorly differentiated colonic carcinoma. These 2 entities may be difficult to differentiate by light microscopy alone. Only limited immunohistochemical studies investigating medullary carcinoma have been reported. These studies suggest a loss of intestinal differentiation, exemplified by a high percentage of CDX2 negativity. Our aim was to further characterize the immunohistochemical profile of medullary carcinoma, with particular emphasis on intestinal markers. Paraffin blocks from 16 cases of medullary carcinoma and 33 cases of poorly differentiated colonic carcinoma were retrieved, and tissue microarrays were constructed and stained with an immunohistochemical panel including CDX2, CK7, CK20, p53, intestinal trefoil factor 3, chromogranin, synaptophysin, MLH-1, MUC-1, MUC-2, and calretinin. A significantly higher proportion of medullary carcinomas, as opposed to poorly differentiated colonic carcinomas, showed loss of staining for MLH-1 and for the intestinal transcription factor CDX2, in accordance with previous studies. MLH-1 staining was present in only 21% of medullary carcinoma cases compared with 60% of the poorly differentiated colonic carcinoma cases (P = .02), whereas CDX2 was positive in 19% of medullary carcinomas and 55% of poorly differentiated colonic carcinomas (P = .03). Interestingly, calretinin staining was strongly positive in 73% of medullary carcinomas compared to only 12% of poorly differentiated colonic carcinomas (P < .0001). Evidence of intestinal differentiation by MUC-1, MUC-2, and TFF-3 staining was seen in 67%, 60%, and 53% of the medullary carcinomas, respectively. These 3 markers were frequently positive in many of the CDX2-negative medullary carcinoma cases. Medullary carcinoma of the colon retains a significant degree of intestinal differentiation as evidenced by its high percentage of

  12. Culturing primary rat inner medullary collecting duct cells.

    PubMed

    Faust, Dörte; Geelhaar, Andrea; Eisermann, Beate; Eichhorst, Jenny; Wiesner, Burkhard; Rosenthal, Walter; Klussmann, Enno; Klussman, Enno

    2013-06-21

    Arginine-vasopressin (AVP) facilitates water reabsorption by renal collecting duct principal cells and thereby fine-tunes body water homeostasis. AVP binds to vasopressin V2 receptors (V2R) on the surface of the cells and thereby induces synthesis of cAMP. This stimulates cellular signaling processes leading to changes in the phosphorylation of the water channel aquaporin-2 (AQP2). Protein kinase A phoshorylates AQP2 and thereby triggers the translocation of AQP2 from intracellular vesicles into the plasma membrane facilitating water reabsorption from primary urine. Aberrations of AVP release from the pituitary or AVP-activated signaling in principal cells can cause central or nephrogenic diabetes insipidus, respectively; an elevated blood plasma AVP level is associated with cardiovascular diseases such as chronic heart failure and the syndrome of inappropriate antidiuretic hormone secretion. Here, we present a protocol for cultivation of primary rat inner medullary collecting duct (IMCD) cells, which express V2R and AQP2 endogenously. The cells are suitable for elucidating molecular mechanisms underlying the control of AQP2 and thus to discover novel drug targets for the treatment of diseases associated with dysregulation of AVP-mediated water reabsorption. IMCD cells are obtained from rat renal inner medullae and are used for experiments six to eight days after seeding. IMCD cells can be cultured in regular cell culture dishes, flasks and micro-titer plates of different formats, the procedure only requires a few hours, and is appropriate for standard cell culture laboratories.

  13. Culturing Primary Rat Inner Medullary Collecting Duct Cells

    PubMed Central

    Faust, Dörte; Geelhaar, Andrea; Eisermann, Beate; Eichhorst, Jenny; Wiesner, Burkhard; Rosenthal, Walter; Klussman, Enno

    2013-01-01

    Arginine-vasopressin (AVP) facilitates water reabsorption by renal collecting duct principal cells and thereby fine-tunes body water homeostasis. AVP binds to vasopressin V2 receptors (V2R) on the surface of the cells and thereby induces synthesis of cAMP. This stimulates cellular signaling processes leading to changes in the phosphorylation of the water channel aquaporin-2 (AQP2). Protein kinase A phoshorylates AQP2 and thereby triggers the translocation of AQP2 from intracellular vesicles into the plasma membrane facilitating water reabsorption from primary urine. Aberrations of AVP release from the pituitary or AVP-activated signaling in principal cells can cause central or nephrogenic diabetes insipidus, respectively; an elevated blood plasma AVP level is associated with cardiovascular diseases such as chronic heart failure and the syndrome of inappropriate antidiuretic hormone secretion. Here, we present a protocol for cultivation of primary rat inner medullary collecting duct (IMCD) cells, which express V2R and AQP2 endogenously. The cells are suitable for elucidating molecular mechanisms underlying the control of AQP2 and thus to discover novel drug targets for the treatment of diseases associated with dysregulation of AVP-mediated water reabsorption. IMCD cells are obtained from rat renal inner medullae and are used for experiments six to eight days after seeding. IMCD cells can be cultured in regular cell culture dishes, flasks and micro-titer plates of different formats, the procedure only requires a few hours, and is appropriate for standard cell culture laboratories. PMID:23852264

  14. Diethyl pyrocarbonate inhibits rostral ventrolateral medullary H+ sensitivity.

    PubMed

    Nattie, E E

    1988-04-01

    Diethyl pyrocarbonate (DEPC), an acylating agent that reacts with imidazole-histidine in vitro, inhibits CO2 sensitivity when applied by pledget to the rostral chemosensitive area on the ventrolateral medullary (VLM) surface in glomectomized, chloralose-urethan-anesthetized cats. In this study similar application of DEPC inhibits the phrenic nerve response to CO2 expressed as a function of VLM [H+] measured by surface pH electrode. Attempts to evaluate direct chemoreceptor stimulation by HCL-soaked surface pledgets proved difficult, but rostral DEPC did inhibit the response to intravenous infusion of HCl. As previously reported, the CO2 and intravenous H+ responses are not a unique function of the VLM [H+]. DEPC had similar inhibitory effects on both the CO2 and the intravenous H+ responses, suggesting that the difference between them may reflect more the orientation or accessibility of the central chemoreceptor than a different mechanism for sensing CO2 vs. H+. DEPC did not alter the phrenic nerve response to hypoxia, indicating that DEPC effects on central chemoreception are not the result of a generalized inhibitory process. The results support the hypothesis that imidazolehistidine is involved at the rostral area with chemoreception of both CO2 and H+.

  15. Hormonal regulation of medullary bone metabolism in the laying hen

    SciTech Connect

    Harrison, J.R.

    1987-01-01

    A new organ culture system for the study of bone formation has been developed using medullary bone, a non-structural, metabolically active form of bone which is found in the marrow cavities of egg-laying birds. In the presence of fetal calf serum, bone explants were viable in culture by morphological criteria, and retained large numbers of osteoblasts and osteoclasts. Incorporation of /sup 3/H-proline into collagenase-digestible protein (CDP) and non-collagen protein (NCP) was determined using purified bacterial collagenase. Collagen accounted for over 10% of the total protein labeled. The calcium-regulating hormones, parathyroid hormone and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), caused a dose-dependent inhibition of /sup 3/H-proline incorporation into CDP. The effective dose range of 1,25(OH)2D3 was 0.1 nM to 100 nM, while that of PTH was 1.0 nM to 100 nM. The effect of both hormones was specific for collagen, since /sup 3/H-proline incorporation into NCP was unaffected. Hydroxyproline analysis of bone explants and culture medium revealed that both hormones decreased the total hydroxyroline content of the cultures, suggesting that the inhibition of /sup 3/H-proline incorporation into DCP is due to inhibition of collagen synthesis.

  16. Medullary thyroid cancer: RET testing of an archival material.

    PubMed

    Godballe, Christian; Jørgensen, Gita; Gerdes, Anne-Marie; Krogdahl, Annelise S; Tybjaerg-Hansen, Anne; Nielsen, Finn C

    2010-04-01

    Medullary thyroid carcinoma (MTC) might be sporadic (75%) or hereditary (25%). Until the mid nineties the diagnosis of hereditary MTC was based on family history, clinical evaluation, histological detection of C-cell hyperplasia and tumor multifocality. Patients and families with hereditary MTC might be missed? Today mutation analysis of the RET proto-oncogene is routinely performed on DNA. Departments of pathology often store tissue specimens from performed surgical procedures. The purpose of this study was to examine if analysis of DNA extracted from formalin fixed archival tissue might be a possible method to identify not previously known cases of hereditary MTC. In 23 cases, tissue analysis was performed, and in 2 patients (9%) a mutation was identified, but in both cases the most likely explanation was contamination with tumor tissue. The ability to detect RET mutations was confirmed by testing of non-tumor tissue from patients with known hereditary MTC. This study shows that genetic testing of archival MTC material is technically possible and might be a way of identifying patients with previously not recognized hereditary MTC.

  17. Hormone receptor status and survival of medullary breast cancer patients

    PubMed Central

    Aksoy, Asude; Odabas, Hatice; Kaya, Serap; Bozkurt, Oktay; Degirmenci, Mustafa; Topcu, Turkan O.; Aytekin, Aydın; Arpaci, Erkan; Avci, Nilufer; Pilanci, Kezban N.; Cinkir, Havva Y.; Bozkaya, Yakup; Cirak, Yalcin; Gumus, Mahmut

    2017-01-01

    Objectives: To analyze the relationship between clinical features, hormonal receptor status, and survival in patients who were diagnosed with medullary breast cancer (MBC). Methods: Demographic characteristics, histopathological features, and survival statuses of 201 patients diagnosed with MBC between 1995 and 2015 were retrospectively recorded. Survival analyses were conducted with uni- and multivariate cox regression analysis. Results: Median follow-up time was 54 (4-272) months. Median patient age at the time of diagnosis was 47 years old (26-90). Of the patients, 91.5% were triple negative. Five-year recurrence free survival time (RFS) rate was 87.4% and overalll survival (OS) rate 95.7%. For RFS, progesterone receptor (PR) negativity, atypical histopathological evaluation, absence of lymphovascular invasion, smaller tumor, lower nodal involvement were found to be favourable prognostic factors by univariate analysis (p<0.05). The PR negativity and smaller tumor were found to be favourable factors by univariate analysis (p<0.05). However, none of these factors were determined as significant independent prognostic factors for OS (p>0.05). Conclusion: Turkish MBC patients exhibited good prognosis, which was comparable with survival outcomes achieved in the literature. The PR negativity was related to a better RFS and OS rates. PMID:28133688

  18. Pretargeted immunoscintigraphy in patients with medullary thyroid carcinoma.

    PubMed Central

    Magnani, P.; Paganelli, G.; Songini, C.; Samuel, A.; Sudati, F.; Siccardi, A. G.; Fazio, F.

    1996-01-01

    To evaluate the use of pretargeted immunoscintigraphy (ISG) in the diagnosis and follow-up of patients with medullary thyroid carcinoma (MTC), we studied 25 patients with histologically proven disease; ISG was repeated after surgery in two patients. The antibody, either an anticarcinoembryonic antigen (CEA) or an antichromogranin A (CgA) biotinylated monoclonal antibody (MAb) or a cocktail of the two biotinylated MAbs was first injected. After 24 h, avidin was administrated i.v., followed by 111In-labelled biotin 24 h later. Fifty-two lesions were visualised. Six primary tumours, diagnosed by increased calcitonin levels, were all correctly diagnosed; 47 recurrences, also suspected by blood tumour markers, were detected and confirmed by cytology or histology. In one case, single photon emission tomography allowed the detection of small lymph nodes with a diameter of 4-7 mm. These lesions, not judged neoplastic by ultrasound, were confirmed to be neoplastic by fine needle aspiration. Pretargeted ISG correctly localises primary tumours and recurrences in MTC patients, when the only marker of relapse is serum elevation of calcitonin. With this three-step pretargeting method, cocktails of potentially useful MAbs can be used, avoiding false-negative studies that may occur when CEA or CgA are not expressed. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:8795589

  19. Recent Updates on the Management of Medullary Thyroid Carcinoma

    PubMed Central

    2016-01-01

    Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor derived from the thyroid C cells producing calcitonin. MTC accounts for 0.6% of all thyroid cancers and incidence of MTC increased steadily between 1997 and 2011 in Korea. It occurs either sporadically or in a hereditary form based on germline rearranged during transfection (RET) mutations. MTC can be cured only by complete resection of the thyroid tumor and any loco-regional metastases. The most appropriate treatment is still less clear in patients with residual or recurrent disease after initial surgery or those with distant metastases because most patients even with metastatic disease have indolent courses with slow progression for several years and MTC is not responsive to either radioactive iodine therapy or thyroid-stimulating hormone suppression. Recently, two tyrosine kinase inhibitors (TKIs), vandetanib and cabozantinib, are approved for use in patients with advanced, metastatic or progressive MTC. In this review, we summarize the current approach according to revised American Thyroid Association guidelines and recent advances in systemic treatment such as TKIs for patients with persistent or recurrent MTC after surgery. PMID:27586449

  20. Histochemical carbonic anhydrase in rat inner medullary collecting duct

    NASA Technical Reports Server (NTRS)

    Kleinman, J. G.; Bain, J. L.; Fritsche, C.; Riley, D. A.

    1992-01-01

    Rat inner medullary collecting duct (IMCD) secretes substantial amounts of H+. However, carbonic anhydrase (CA), a concomitant of H+ secretion, has been generally reported absent in this segment. To reexamine this problem, we investigated CA and the morphological phenotypes of cells comprising the IMCD by CA histochemistry, using a modified Hansson technique with light and electron microscopy. Throughout the medulla, tubule cells exhibit histochemical CA activity. In the initial third of the inner medulla, a small proportion have features of intercalated cells and demonstrate some degree of CA activity. However, the majority population in the early portions of the IMCD appears to consist of principal cells. These also show CA staining of widely variable intensity, both among and within cells. A third cell type, previously called "IMCD cells", appears in the middle portion of the IMCD and is the only cell type present near the papilla tip. In contrast to previous reports, these "IMCD cells" have histochemical CA staining, also of highly variable intensity. These results demonstrate that stainable carbonic anhydrase to support acidification is present throughout the rat IMCD, both in intercalated cells and in some cells clearly not of this type. Therefore, the presence of CA is not specific for the intercalated cell type and suggests that other cell types may participate in acid secretion in IMCD.

  1. ACES: The ASCENDS CarbonHawk Experiment Simulator

    NASA Astrophysics Data System (ADS)

    Obland, M. D.; Prasad, N. S.; Harrison, F. W.; Browell, E. V.; Ismail, S.; Dobler, J. T.; Moore, B.; Zaccheo, T.; Campbell, J.; Chen, S.; Cleckner, C. S.; DiJoseph, M.; Little, A.; Notari, A.; Refaat, T. F.; Rosenbaum, D.; Vanek, M. D.; Bender, J.; Braun, M.; Chavez-Pirson, A.; Neal, M.; Rayner, P. J.; Rosiewicz, A.; Shure, M.; Welch, W.

    2012-12-01

    The ASCENDS CarbonHawk Experiment Simulator (ACES) is a NASA Langley Research Center project funded by NASA's Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP) that seeks to advance technologies critical to measuring atmospheric column carbon dioxide (CO2) mixing ratios in support of the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. The technologies being advanced are: (1) a high bandwidth detector, (2) a multi-aperture telescope assembly, (3) advanced algorithms for cloud and aerosol discrimination, and (4) high-efficiency, multiple-amplifier CO2 and O2 laser transmitters. The instrument architecture will be developed to operate on a high-altitude aircraft and will be directly scalable to meet the ASCENDS mission requirements. These technologies are viewed as critical towards developing an airborne simulator and eventual spaceborne instrument with lower size, mass, and power consumption, and improved performance. The detector effort will improve the existing detector subsystem by increasing its bandwidth to a goal of 5 MHz, reducing its overall mass from 18 lbs to <10 lbs, and stretching the duration of autonomous, service-free operation periods from 4 hrs to >24 hrs. The development goals are to permit higher laser modulation rates, which provides greater flexibility for implementing thin-cloud discrimination algorithms as well as improving range resolution and error reduction, and to enable long flights on a high-altitude unmanned aerial vehicle (UAV). The telescope development consists of a three-telescope design built for the constraints of the Global Hawk aircraft. This task addresses the ability of multiple smaller telescopes to provide equal or greater collection efficiency compared with a single larger telescope with a reduced impact on launch mass and cost. The telescope assembly also integrates fiber-coupled transmit collimators for all of the laser transmitters and fiber-coupled optical

  2. Atmospheric CO2 Variability Observed during ASCENDS Flight Campaigns

    NASA Astrophysics Data System (ADS)

    Lin, B.; Browell, E. V.; Campbell, J. F.; Choi, Y.; Dobler, J. T.; Fan, T. F.; Harrison, F. W.; Kooi, S. A.; Liu, Z.; Meadows, B.; Nehrir, A. R.; Obland, M. D.; Plant, J.; Yang, M. M.

    2015-12-01

    Accurate observations of atmospheric CO2 with a space-based lidar system, such as for the NASA ASCENDS mission, will improve knowledge of global CO2 distribution and variability and increase the confidence in predictions of future climate changes. To prepare for the ASCENDS mission, the NASA Langley Research Center and Exelis Inc. (now part of Harris Corp.) have been collaborating in the development and evaluation of an Intensity-Modulated Continuous-Wave (IM-CW) lidar approach for measuring atmospheric CO2 from space. Two airborne IM-CW lidars operating in the 1.57-mm CO2 absorption band have been developed and flight tested to demonstrate precise atmospheric CO2 column measurements. A total of 14 flight campaigns have been conducted with the two lidar and in-situ CO2 measurement systems. Significant atmospheric CO2 variations on various spatiotemporal scales were observed during these campaigns. For example, around 10-ppm CO2 changes were found within free troposphere in a region of about 200×300 km2 over Iowa during a summer 2014 flight. Even over extended forests, about 2-ppm CO2 column variability was measured within about 500-km distance. For winter times, especially over snow covered ground, relatively less horizontal CO2 variability was observed, likely owing to minimal interactions between the atmosphere and land surface. Inter-annual variations of CO2 drawdown over cornfields in the Mid-West were found to be larger than 5 ppm due to slight differences in the corn growing phase and meteorological conditions even in the same time period of a year. Furthermore, considerable differences in atmospheric CO2 profiles were found during winter and summer campaigns. In the winter CO2 was found to decrease from about 400 ppm in the atmospheric boundary layer (ABL) to about 392 ppm above 10 km, while in the summer CO2 increased from 386 ppm in the ABL to about 396 ppm in free troposphere. These and other CO2 observations are discussed in this presentation.

  3. Feasibility of Quantifying Arterial Cerebral Blood Volume Using Multiphase Alternate Ascending/Descending Directional Navigation (ALADDIN)

    PubMed Central

    Kim, Ki Hwan; Choi, Seung Hong; Park, Sung-Hong

    2016-01-01

    Arterial cerebral blood volume (aCBV) is associated with many physiologic and pathologic conditions. Recently, multiphase balanced steady state free precession (bSSFP) readout was introduced to measure labeled blood signals in the arterial compartment, based on the fact that signal difference between labeled and unlabeled blood decreases with the number of RF pulses that is affected by blood velocity. In this study, we evaluated the feasibility of a new 2D inter-slice bSSFP-based arterial spin labeling (ASL) technique termed, alternate ascending/descending directional navigation (ALADDIN), to quantify aCBV using multiphase acquisition in six healthy subjects. A new kinetic model considering bSSFP RF perturbations was proposed to describe the multiphase data and thus to quantify aCBV. Since the inter-slice time delay (TD) and gap affected the distribution of labeled blood spins in the arterial and tissue compartments, we performed the experiments with two TDs (0 and 500 ms) and two gaps (300% and 450% of slice thickness) to evaluate their roles in quantifying aCBV. Comparison studies using our technique and an existing method termed arterial volume using arterial spin tagging (AVAST) were also separately performed in five subjects. At 300% gap or 500-ms TD, significant tissue perfusion signals were demonstrated, while tissue perfusion signals were minimized and arterial signals were maximized at 450% gap and 0-ms TD. ALADDIN has an advantage of visualizing bi-directional flow effects (ascending/descending) in a single experiment. Labeling efficiency (α) of inter-slice blood flow effects could be measured in the superior sagittal sinus (SSS) (20.8±3.7%.) and was used for aCBV quantification. As a result of fitting to the proposed model, aCBV values in gray matter (1.4–2.3 mL/100 mL) were in good agreement with those from literature. Our technique showed high correlation with AVAST, especially when arterial signals were accentuated (i.e., when TD = 0 ms) (r = 0

  4. Neural control of adrenal medullary and cortical blood flow during hemorrhage

    SciTech Connect

    Breslow, M.J.; Jordan, D.A.; Thellman, S.T.; Traystman, R.J.

    1987-03-01

    Hemorrhagic hypotension produces an increase in adrenal medullary blood flow and a decrease in adrenal cortical blood flow. To determine whether changes in adrenal blood flow during hemorrhage are neurally mediated, the authors compared blood flow responses following adrenal denervation (splanchnic nerve section) with changes in the contralateral, neurally intact adrenal. Carbonized microspheres labeled with /sup 153/Gd, /sup 114/In, /sup 113/Sn, /sup 103/Ru, /sup 95/Nb or /sup 46/Se were used. Blood pressure was reduced and maintained at 60 mmHg for 25 min by hemorrhage into a pressurized bottle system. Adrenal cortical blood flow decreased to 50% of control with hemorrhage in both the intact and denervated adrenal. Adrenal medullary blood flow increased to four times control levels at 15 and 25 min posthemorrhage in the intact adrenal, but was reduced to 50% of control at 3, 5, and 10 min posthemorrhage in the denervated adrenal. In a separate group of dogs, the greater splanchnic nerve on one side was electrically stimulated at 2, 5, or 15 Hz for 40 min. Adrenal medullary blood flow increased 5- to 10-fold in the stimulated adrenal but was unchanged in the contralateral, nonstimulated adrenal. Adrenal cortical blood flow was not affected by nerve stimulation. They conclude that activity of the splanchnic nerve profoundly affects adrenal medullary vessels but not adrenal cortical vessels and mediates the observed increase in adrenal medullary blood flow during hemorrhagic hypotension.

  5. Atmospheric CO2 Variability Observed From ASCENDS Flight Campaigns

    NASA Technical Reports Server (NTRS)

    Lin, Bing; Browell, Edward; Campbell, Joel; Choi, Yonghoon; Dobler, Jeremy; Fan, Tai-Fang; Harrison, F. Wallace; Kooi, Susan; Liu, Zhaoyan; Meadows, Byron; Nehrir, Amin; Obland, Michael; Plant, James; Yang, Melissa

    2015-01-01

    Significant atmospheric CO2 variations on various spatiotemporal scales were observed during ASCENDS flight campaigns. For example, around 10-ppm CO2 changes were found within free troposphere in a region of about 200x300 sq km over Iowa during a summer 2014 flight. Even over extended forests, about 2-ppm CO2 column variability was measured within about 500-km distance. For winter times, especially over snow covered ground, relatively less horizontal CO2 variability was observed, likely owing to minimal interactions between the atmosphere and land surface. Inter-annual variations of CO2 drawdown over cornfields in the Mid-West were found to be larger than 5 ppm due to slight differences in the corn growing phase and meteorological conditions even in the same time period of a year. Furthermore, considerable differences in atmospheric CO2 profiles were found during winter and summer campaigns. In the winter CO2 was found to decrease from about 400 ppm in the atmospheric boundary layer (ABL) to about 392 ppm above 10 km, while in the summer CO2 increased from 386 ppm in the ABL to about 396 ppm in free troposphere. These and other CO2 observations are discussed in this presentation.

  6. Local mechanical properties of human ascending thoracic aneurysms.

    PubMed

    Davis, Frances M; Luo, Yuanming; Avril, Stéphane; Duprey, Ambroise; Lu, Jia

    2016-08-01

    Ascending thoracic aortic aneurysms (ATAAs) are focal, asymmetric dilatations of the aortic wall which are prone to rupture. To identify potential rupture locations in advance, it is necessary to consider the inhomogeneity of the ATAA at the millimeter scale. Towards this end, we have developed a combined experimental and computational approach using bulge inflation tests, digital image correlation (DIC), and an inverse membrane approach to characterize the pointwise stress, strain, and hyperelastic properties of the ATAA. Using this approach, the pointwise hyperelastic material properties were identified on 10 human ATAA samples collected from patients undergoing elective surgery to replace their ATAAs with a graft. Our method was able to capture the varying levels of heterogeneity in the ATAA from regional to local. It was shown for the first time that the material properties in the ATAA are unmistakably heterogeneous at length scales between 1mm and 1cm, which are length scales where vascular tissue is typically treated as homogeneous. The distributions of the material properties for each patient were also examined to study the inter- and intra-patient variability. Large inter-subject variability was observed in the elastic properties.

  7. Patient-specific finite element analysis of ascending aorta aneurysms

    PubMed Central

    Martin, Caitlin; Elefteriades, John

    2015-01-01

    Catastrophic ascending aorta aneurysm (AsAA) dissection and rupture can be prevented by elective surgical repair, but identifying individuals at risk remains a challenge. Typically the decision to operate is based primarily on the overall aneurysm size, which may not be a reliable indicator of risk. In this study, AsAA inflation and rupture was simulated in 27 patient-specific finite element models constructed from clinical CT imaging data and tissue mechanical testing data from matching patients. These patients included n = 8 with concomitant bicuspid aortic valve (BAV), n = 10 with bovine aortic arch (BAA), and n = 10 with neither BAV nor BAA. AsAA rupture risk was found to increase with elevated systolic wall stress and tissue stiffness. The aortic size index was sufficient for identifying the patients with the lowest risk of rupture, but unsuitable for delineating between patients at moderate and high risk. There was no correlation between BAV or BAA and AsAA rupture risk; however, the AsAA morphology was different among these patients. These results support the use of mechanical parameters such as vessel wall stress and tissue stiffness for AsAA presurgical evaluation. PMID:25770248

  8. RET mutation and increased angiogenesis in medullary thyroid carcinomas.

    PubMed

    Verrienti, Antonella; Tallini, Giovanni; Colato, Chiara; Boichard, Amélie; Checquolo, Saula; Pecce, Valeria; Sponziello, Marialuisa; Rosignolo, Francesca; de Biase, Dario; Rhoden, Kerry; Casadei, Gian Piero; Russo, Diego; Visani, Michela; Acquaviva, Giorgia; Ferdeghini, Marco; Filetti, Sebastiano; Durante, Cosimo

    2016-08-01

    Advanced medullary thyroid cancers (MTCs) are now being treated with drugs that inhibit receptor tyrosine kinases, many of which involved in angiogenesis. Response rates vary widely, and toxic effects are common, so treatment should be reserved for MTCs likely to be responsive to these drugs. RET mutations are common in MTCs, but it is unclear how they influence the microvascularization of these tumors. We examined 45 MTCs with germ-line or somatic RET mutations (RETmut group) and 34 with wild-type RET (RETwt). Taqman Low-Density Arrays were used to assess proangiogenic gene expression. Immunohistochemistry was used to assess intratumoral, peritumoral and nontumoral expression levels of VEGFR1, R2, R3, PDGFRa, PDGFB and NOTCH3. We also assessed microvessel density (MVD) and lymphatic vessel density (LVD) based on CD31-positive and podoplanin-positive vessel counts, respectively, and vascular pericyte density based on staining for a-smooth muscle actin (a-SMA), a pericyte marker. Compared with RETwt tumors, RETmut tumors exhibited upregulated expression of proangiogenic genes (mRNA and protein), especially VEGFR1, PDGFB and NOTCH3. MVDs and LVDs were similar in the two groups. However, microvessels in RETmut tumors were more likely to be a-SMA positive, indicating enhanced coverage by pericytes, which play key roles in vessel sprouting, maturation and stabilization. These data suggest that angiogenesis in RETmut MTCs may be more intense and complete than that found in RETwt tumors, a feature that might increase their susceptibility to antiangiogenic therapy. Given their increased vascular pericyte density, RETmut MTCs might also benefit from combined or preliminary treatment with PDGF inhibitors.

  9. Altered processing of otolithic information in isolated lateral medullary infarction.

    PubMed

    Kim, Hyo-Jung; Kim, Seoyeon; Park, Jae Han; Kim, Ji-Soo

    2016-12-01

    Ocular and cervical vestibular-evoked myogenic potentials (VEMPs) evaluate the function of otolithic pathways in central as well as peripheral vestibular disorders. This study aimed to determine the associations and dissociations of otolithic dysfunction in lateral medullary infarction (LMI), the most well-known disorder of central vestibulopathy. At the Dizziness Clinic of a referral-based University Hospital, 45 patients with isolated LMI (28 men, mean age = 55.6 ± 12.5) had evaluation of the ocular tilt reaction (OTR), tilt of the subjective visual vertical (SVV), and ocular and cervical VEMPs from Janurary 2011 to August 2015 during the acute phase, 1-11 days from the symptom onset (median = 2 days). Almost all (42/45, 93 %) patients showed at least one component of the OTR or SVV tilt that was invariably ipsiversive. In contrast, oVEMPs were abnormal only in 12 (27 %) and cVEMPs in 13 (29 %) patients. Only three patients showed abnormal results in all the tests of the OTR, SVV tilt, and ocular and cervical VEMPs. Abnormal oVEMPs were more common in patients with the OTR than those without (38 vs 6 %, Pearson X (2) test, p = 0.021). In contrast, abnormality of cVEMPs showed no correlation with the presence of OTR (28 vs 31 %, Pearson X (2) test, p = 0.795). In patients with LMI, ipsiversive OTR is invariable, but abnormalities of oVEMPs and cVEMPs were much less common and mostly dissociated even in the patients with abnormal results. This discrepancy in otolithic dysfunction suggests different anatomical substrates and/or dissimilar reciprocal modulation for processing of each otolithic signal in central vestibular structures located in the dorsolateral medulla.

  10. Medullary carcinoma of the large intestine: a population based analysis.

    PubMed

    Thirunavukarasu, Pragatheeshwar; Sathaiah, Magesh; Singla, Smit; Sukumar, Shyam; Karunamurthy, Arivarasan; Pragatheeshwar, Kothai Divya; Lee, Kenneth K W; Zeh, Herbert; Kane, Kevin M; Bartlett, David L

    2010-10-01

    Medullary carcinoma (MC) of the colorectum is a relatively new histological type of adenocarcinoma characterized by poor glandular differentiation and intraepithelial lymphocytic infiltrate. To date, there has been no epidemiological study of this rare tumor type, which has now been incorporated as a separate entity in the World Health Organization (WHO) classification of colorectal cancers. We used the population-based registries of the Surveillance, Epidemiology and End Results (SEER) database to identify all cases of colorectal MC between 1973 and 2006 and compared them to poorly and undifferentiated colonic adenocarcinomas (PDA and UDA, respectively). We observed that MCs were rare tumors, constituting approximately 5-8 cases for every 10,000 colon cancers diagnosed, with a mean annual incidence of 3.47 (+/-0.75) per 10 million population. Mean age at diagnosis was 69.3 (+/-12.5) years, with incidence increasing with age. MCs were twice as common in females, who presented at a later age, with a lower stage and a trend towards favorable prognosis. MCs were extremely rare among African-Americans. MCs were most common in the proximal colon (74%), where they present at a later age than the sigmoid colon. There were no cases reliably identified in the rectum or appendix. Serum carcinoembryonic antigen levels (CEA) were elevated prior to first course of treatment in 40% of the patients. MCs were more commonly poorly differentiated (72%), with 22% being undifferentiated. MCs commonly presented with Stage II disease, with 10% presenting with metastases. Only one patient presented with N2b disease (>7 positive nodes). Early outcome analyses showed that MCs have 1- and 2-year relative survival rates of 92.7 and 73.8% respectively. Although MCs showed a trend towards better early overall survival, undifferentiated MCs present more commonly with Stage III, with comparatively worse early outcomes.

  11. GABA Signaling and Neuroactive Steroids in Adrenal Medullary Chromaffin Cells

    PubMed Central

    Harada, Keita; Matsuoka, Hidetada; Fujihara, Hiroaki; Ueta, Yoichi; Yanagawa, Yuchio; Inoue, Masumi

    2016-01-01

    Gamma-aminobutyric acid (GABA) is produced not only in the brain, but also in endocrine cells by the two isoforms of glutamic acid decarboxylase (GAD), GAD65 and GAD67. In rat adrenal medullary chromaffin cells only GAD67 is expressed, and GABA is stored in large dense core vesicles (LDCVs), but not synaptic-like microvesicles (SLMVs). The α3β2/3γ2 complex represents the majority of GABAA receptors expressed in rat and guinea pig chromaffin cells, whereas PC12 cells, an immortalized rat chromaffin cell line, express the α1 subunit as well as the α3. The expression of α3, but not α1, in PC12 cells is enhanced by glucocorticoid activity, which may be mediated by both the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR). GABA has two actions mediated by GABAA receptors in chromaffin cells: it induces catecholamine secretion by itself and produces an inhibition of synaptically evoked secretion by a shunt effect. Allopregnanolone, a neuroactive steroid which is secreted from the adrenal cortex, produces a marked facilitation of GABAA receptor channel activity. Since there are no GABAergic nerve fibers in the adrenal medulla, GABA may function as a para/autocrine factor in the chromaffin cells. This function of GABA may be facilitated by expression of the immature isoforms of GAD and GABAA receptors and the lack of expression of plasma membrane GABA transporters (GATs). In this review, we will consider how the para/autocrine function of GABA is achieved, focusing on the structural and molecular mechanisms for GABA signaling. PMID:27147972

  12. New drugs for medullary thyroid cancer: new promises?

    PubMed

    Spitzweg, Christine; Morris, John C; Bible, Keith C

    2016-06-01

    Medullary thyroid cancer (MTC) is a rare tumor arising from the calcitonin-producing parafollicular C cells of the thyroid gland, occurring either sporadically or alternatively in a hereditary form based on germline RET mutations in approximately one-third of cases. Historically, patients with advanced, metastasized MTC have had a poor prognosis, partly due to limited response to conventional chemotherapy and radiation therapy. In the past decade, however, considerable progress has been made in identifying key genetic alterations and dysregulated signaling pathways paving the way for the evaluation of a series of multitargeted kinase inhibitors that have started to meaningfully impact clinical practice. Two drugs, vandetanib and cabozantinib, are now approved in the US and EU for use in advanced, progressive MTC, with additional targeted agents also showing promise or awaiting results from clinical trials. However, the potential for toxicities with significant reduction in quality of life and lack of curative outcomes has to be carefully weighed against potential for benefit. Despite significant PFS prolongation observed in randomized clinical trials, most patients even with metastatic disease enjoy indolent courses with slow progression observed over years, wherein watchful waiting is still the preferred strategy. As advanced, progressive MTC is a rare and complex disease, a multidisciplinary approach centered in specialized centers providing interdisciplinary expertise in the individualization of available therapeutic options is preferred. In this review, we summarize current concepts of the molecular pathogenesis of advanced MTC and discuss results from clinical trials of targeted agents and also cytotoxic chemotherapy in the context of clinical implications and future perspectives.

  13. Systemic treatment and management approaches for medullary thyroid cancer.

    PubMed

    Ernani, Vinicius; Kumar, Mukesh; Chen, Amy Y; Owonikoko, Taofeek K

    2016-11-01

    Although rare, medullary thyroid cancer (MTC) exemplifies the value that ever-expanding knowledge of molecular pathways and mechanisms brings to managing challenging cancers. Although surgery can be curative for MTC in many patients, a substantial proportion of patients present with locoregional or distant metastatic disease. Once distant disease occurs, treatment options are limited, and conventional cancer treatments such as cytotoxic chemotherapy are of minimal benefit. Biomarkers such as calcitonin and carcinoembryonic antigen are important correlates of disease burden as well as predictors of disease progress, including recurrence and survival. MTC is either sporadic (∼75%) or inherited (∼25%) as an autosomal dominant disease. Regardless, germline and somatic mutations, particularly in the rearranged during transfection (RET) proto-oncogene, are key factors in the neoplastic process. Gain-of-function RET mutations result in overactive proteins that lead to abnormal activation of downstream signal transduction pathways, resulting in ligand-independent growth and resistance to apoptotic stimuli. Specific RET mutation variants have been found to correlate with phenotype and natural history of MTC with some defects portending a more aggressive clinical course. Greater understanding of the consequence of the aberrant signaling pathway has fostered the development of targeted therapies. Two small-molecule tyrosine kinase inhibitors, vandetanib and cabozantinib, are currently available as approved agents for the treatment of advanced or progressive MTC and provide significant increases in progression-free survival. Since there have been no head-to-head comparisons, clinicians often select between these agents on the basis of familiarity, patient characteristics, comorbidities, and toxicity profile.

  14. Neurones in the adult rat anterior medullary velum.

    PubMed

    Ibrahim, M; Menoud, P A; Celio, M R

    2000-03-27

    The presence of neurones in the rat anterior medullary velum (AMV) has been investigated by using antibodies to the calcium-binding proteins, parvalbumin (PV), calretinin (CR), and calbindin-D28k (CB). Disparate populations of mainly GABAergic neurones were located in the rostral and caudal regions of the AMV. The rostral region of the AMV was characterised by GABAergic CR-labelled or PV-labelled neurones. CR-labelled neurones were bipolar or multipolar with round to ovoid somata (diameters between 8 and 12 microm), and rostrocaudally running dendrites forming a network. PV-labelled neurones had round somata (diameters between 6 and 10 microm) and were bi-tufted, with beaded dendrites. Both CR-labelled and PV-labelled dendrites formed punctate pericellular associations with unlabelled somatic profiles. In the caudal region of the AMV, PV-labelled neurones were GABAergic, multipolar cells, having round somata (diameters between 9 and 12 microm), with either beaded or nonbeaded dendrites forming a network of interconnecting dendrites. PV-labelled pericellular associations were made around both PV-labelled and unlabelled somatic profiles. CR labelled unipolar brush cells (UBCs) were not GABAergic. UBCs were characterised by a round to oval somata (10-15 microm in diameter) from which a single primary dendrite emerged to form a distal expansion having small terminal dendrites. From the distal expansion, there also appeared to be CR-labelled processes emanating and extending for up to 250 microm. CB occasionally labelled "Purkinje-like cells" (PLCs). The rat AMV is a more complex structure than first envisaged with the presence of predominantly inhibitory neurones expressing different calcium-binding proteins. Functional and anatomic aspects of this circuitry are further discussed.

  15. Impact of Range Precision Requirements on Emitted Laser Power for ASCENDS Lidar

    NASA Astrophysics Data System (ADS)

    Heaps, W. S.

    2013-12-01

    The goal of the ASCENDS mission which was recommended to NASA by the National Academy of Science Decadal Survey of Earth Science in 2007 is to measure the dry air column mixing ratio of carbon dioxide in the atmosphere using lidar technology with a precision on the order of 1 part per million. Because the column for CO2 is nearing 400 ppm this requires a measurement precision of about 400:1. The approaches under development by a number of groups in industry and at NASA centers all employ Integrated Path Differential Absorption (IPDA)Lidar. This means that two or more wavelengths of light are transmitted. The differences in the reflected intensities at various wavelengths and their relative strength of absorption are then to infer the amount of CO2 present in the path through the atmosphere. It can rather easily be shown that the optimal absorption in order to achieve the highest precision for a given light intensity is 1/e. Stronger absorption reduces the signal levels for the absorbed wavelengths and weaker absorptions require the observation of a small difference between two large numbers. Analysis of the signals obtainable using perfect photon counting detectors reveal that approximately 500:1 signal to noise ratio can be obtained by detecting 1000000 photons at the unabsorbed wavelength and 1/e million photons at the absorbed wavelength. The ASCENDS requirement is one measurement every 100 km of ground track--about once every 14 sec at typical satellite speeds or a photon count rate of ~70000 per sec. In addition to the absorption signal the lidar is also employed to measure the length of the path taken by the light through the atmosphere. This is accomplished by timing the propagation of a pulse (or some other discontinuity) in the rate of photon arrival at the detector. Because the nominal ';thickness' of the atmosphere is about 7 km the path length must be measured with a precision of 1/400 of 7 km (about 17.5 m) in order for the column to be determined with

  16. Effect of medullary cavity in cancellous bone on two-wave phenomenon

    NASA Astrophysics Data System (ADS)

    Hachiken, Takuma; Nakanishi, Shoko; Matsukawa, Mami

    2016-07-01

    Osteoporotic patients have a larger medullary cavity in their cancellous bone than healthy people. In this study, the effect of the medullary cavity on the two-wave phenomenon was experimentally investigated using a cancellous bone model and a radius bone model. In the cancellous bone model, with the increase in hole (medullary cavity) diameter, the amplitudes of the fast waves became smaller, whereas the amplitudes of the slow waves became larger. In the radius bone model, the fast wave overlapped with the circumferential wave. The slow wave became larger with increasing hole diameter. The analysis of the slow wave thus seems to be useful for the in vivo diagnosis of the degree of osteoporosis.

  17. Lateral medullary infarction presenting as isolated vertigo and unilateral loss of visual suppression.

    PubMed

    Kishi, Masahiko; Sakakibara, Ryuji; Nomura, Toshiyuki; Yoshida, Tomoe; Yamamoto, Masahiko; Kataoka, Manabu; Ogawa, Emina; Tateno, Fuyuki

    2012-02-01

    Isolated vertigo is rare in lateral medullary infarction. We described early diagnostic challenges in such cases by a neuro-otological approach. We report a 56-year-old man who developed a lateral medullary infarction that presented as isolated vertigo. Before the day 4 from disease onset when diffusion-weighted magnetic resonance imaging (MRI) became positive, this patient showed unilateral loss of visual suppression, a central type of vestibular dysfunction. Since MRI abnormalities may not appear in the early few days from disease onset, unilateral loss of visual suppression might become an important diagnostic option for isolated vertigo due to a lateral medullary infarction. This finding is presumably relevant to the inferior olive lesion.

  18. Panmedullary edema with inferior olivary hypertrophy in bilateral medial medullary infarction.

    PubMed

    Inoue, Yasuteru; Miyashita, Fumio; Koga, Masatoshi; Yamada, Naoaki; Toyoda, Kazunori; Minematsu, Kazuo

    2014-03-01

    Bilateral medial medullary infarction (MMI) is a rare type of stroke with poor outcomes. Inferior olivary nucleus hypertrophy results from a pathologic lesion in the Guillain-Mollaret triangle. The relationship between inferior olivary nucleus hypertrophy and the medullary lesion is obscure. To the best of our knowledge, only 1 autopsy case with unilateral medial medullary infarction that was associated with ipsilateral inferior olivary nucleus hypertrophy has been reported. We describe a rare case with acute infarction in the bilateral medial medulla oblongata accompanied by subacute bilateral inferior olivary nucleus hypertrophy and panmedullary edema. The hypertrophy appeared to have been caused by local ischemic damage to the termination of the central tegmental tract at the bilateral inferior olivary nucleus.

  19. [A case of medial medullary infarction with persistent primitive hypoglossal artery].

    PubMed

    Jin, Kazutaka; Aihara, Naoto; Tsukamoto, Tetsuro

    2002-04-01

    A 66-year-old woman was admitted to our hospital because of vomiting, dizziness and vertigo. Neurological examination on admission revealed only upbeat nystagmus without cranial nerve symptoms, paresis, cerebellar signs or sensory disturbances. Magnetic resonance(MR) images demonstrated a new T 2 high intensity and T 1 iso-intensity signal lesion in the right upper medial medulla. This medial medullary infarction caused central vestibular dysfunction. MR angiography and digital subtraction angiography demonstrated a persistent primitive hypoglossal artery (PPHA) originating from the right internal carotid artery to the vertebrobasilar artery associated with the stenosis of the right internal carotid artery at the level of the cervical bifurcation. This is the first report of medullary infarction with persistent carotid-basilar anastomosis. We suspected this medullary infarction was caused by artery to artery embolism in the branch of the right vertebral artery through the PPHA distal originated from the stenosis of the right internal carotid artery.

  20. Adrenocortical hemorrhagic necrosis: the role of catecholamines and retrograde medullary-cell embolism

    SciTech Connect

    Szabo, S.; McComb, D.J.; Kovacs, K.; Huettner, I.

    1981-10-01

    We investigated the pathogenesis of adrenal necrosis using animal models of the disease (induced by administration of acrylonitrile, cysteamine, or pyrazole) and human cases. Results of electron-microscopic and histochemical time-response studies with rat models revealed an early, retrograde embolization of medullary cells and cell fragments in the cortical capillaries that showed prominent endothelial injury. The experimental adrenal lesions were prevented by surgical removal of the medulla one month before administration of adrenocorticolytic chemicals, or by the administration of the alpha-adrenergic antagonist phenoxybenzamine hydrochloride. Histochemical staining for medullary (argyrophil) granules in human cases of adrenal necrosis demonstrated tissue fragments that stained positively for silver in vascular cortical spaces in nine of ten autopsy specimens and in all four surgical cases we reviewed. Thus, catecholamines released from the adrenal medulla and from the retrograde medullary emboli in the cortex may have a role in the pathogenesis of adrenocortical necrosis.

  1. A Common Stem Cell for Murine Cortical and Medullary Thymic Epithelial Cells?

    PubMed Central

    Van Soest, Peter; Platenburg, Peter Paul; Van Ewijk, Willem

    1995-01-01

    We have addressed the question whether the epithelial stroma in the thymus is derived from a common stem cell or whether cortical and medullary epithelial cells are derived from different embryonic stem cells emerging, for example, from endoderm and ectoderm. By the use of rapidly expanding cultures of thymic epithelial cells (TEC) from 14 to 16 day-old murine fetuses and by specific antibodies against cortical and medullary epithelium, respectively, we were able to demonstrate a small subpopulation of double-labeled TEC in the cultures. These cells were not present in TEC cultures initiated from thymuses of neonatal mice. Double-labeled TEC were also found in tissue sections from fetal thymuses. These findings may indicate that TEC populations of the cortex and the medulla are derived from a common stem cell, with potential for differentiation toward both cortical and medullary TEC. PMID:9700364

  2. Is Hashimoto's thyroiditis a risk factor for medullary thyroid carcinoma? Our experience and a literature review.

    PubMed

    Zayed, Ayman A; Ali, Moaath K Mustafa; Jaber, Omar I; Suleiman, Moh'd J; Ashhab, Ashraf A; Al Shweiat, Wajdi Mohammed; Momani, Munther Suliaman; Shomaf, Maha; AbuRuz, Salah Mohammed

    2015-03-01

    The etiology of medullary thyroid carcinoma remains unknown. The aim of this study was to determine whether there is a significant association between medullary thyroid carcinoma and Hashimoto's thyroiditis in the histopathologic material of thyroidectomized patients. Retrospective cross-sectional study. In this study, we reviewed the medical records of all patients who underwent total thyroidectomy for different thyroid-related complaints between January 2000 and January 2012 at Jordan University Hospital-Amman, Jordan. To highlight relevant previously published studies addressing this topic, a literature search was conducted for English language studies reporting "medullary thyroid carcinoma" or "C-cell hyperplasia" in patients with Hashimoto's thyroiditis. Of the 863 patients with a mean age of 47.2 ± 12.3 years who underwent total thyroidectomy during the study period, 78 (9.04 %) were diagnosed with Hashimoto's thyroiditis, and 15 (1.74 %) had medullary thyroid carcinoma, 3 (20 %) of whom had coexistent Hashimoto's thyroiditis. A total of 683 (79.1 %) patients had benign thyroid disease, 67 (9.8 %) of whom had Hashimoto's thyroiditis. The difference between these rates was not statistically significant (p = 0.19). When examined by gender, 9 females had medullary thyroid carcinoma, 3 (33.3 %) of whom had coexistent Hashimoto's thyroiditis; by contrast, of 560 females with benign thyroid disease, 62 (11.1 %) had Hashimoto's thyroiditis (p = 0.04). Although this study population represents a small and single-institution experience, our results suggest that there might be an association between Hashimoto's thyroiditis and medullary thyroid carcinoma only in female patients who undergo total thyroidectomy.

  3. Decreased GABAA Receptor Binding in the Medullary Serotonergic System In the Sudden Infant Death Syndrome

    PubMed Central

    Broadbelt, Kevin G.; Paterson, David S.; Belliveau, Richard A.; Trachtenberg, Felicia L.; Haas, Elisabeth A.; Stanley, Christina; Krous, Henry F.; Kinney, Hannah C.

    2011-01-01

    γ-Aminobutyric acid (GABA) neurons in the medulla oblongata help regulate homeostasis, in part through interactions with the medullary serotonergic (5-HT) system. Previously, we reported abnormalities in multiple 5-HT markers in the medullary 5-HT system of infants dying from sudden infant death syndrome (SIDS), suggesting that 5-HT dysfunction is involved in its pathogenesis. Here, we tested the hypothesis that markers of GABAA receptors are decreased in the medullary 5-HT system in SIDS cases compared to controls. Using tissue receptor autoradiography with the radioligand 3H-GABA, we found 25–52% reductions in GABAA receptor binding density in 7 of 10 key nuclei sampled of the medullary 5-HT system in the SIDS cases (postconceptional age [PCA] = 51.7 ± 8.3, n = 28) vs. age-adjusted controls (PCA = 55.3 ± 13.5, n = 8) (p ≤ 0.04). By Western blotting there was 46.2% reduction in GABAAα3 subunit levels in the gigantocellularis (component of the medullary 5-HT system) of SIDS cases (PCA = 53.9 ± 8.4, n = 24) vs. controls (PCA = 55.3 ± 8.3, n = 8) (56.8% standard in SIDS cases vs. 99.35% in controls; p = 0.026). These data suggest that medullary GABAA receptors are abnormal in SIDS infants and that SIDS is a complex disorder of a homeostatic network in the medulla that involves deficits of the GABAergic and 5-HT systems. PMID:21865888

  4. PREFACE: Eclipse on the Coral Sea: Cycle 24 Ascending

    NASA Astrophysics Data System (ADS)

    Cally, Paul; Erdélyi, Robert; Norton

    2013-06-01

    A total solar eclipse is the most spectacular and awe-inspiring astronomical phenomenon most people will ever see in their lifetimes. Even hardened solar scientists draw inspiration from it. The eclipse with 2 minutes totality in the early morning of 14 November 2012 (local time) drew over 120 solar researchers (and untold thousands of the general public) to the small and picturesque resort town of Palm Cove just north of Cairns in tropical north Queensland, Australia, and they were rewarded when the clouds parted just before totality to reveal a stunning solar display. Eclipse photograph The eclipse was also the catalyst for an unusually broad and exciting conference held in Palm Cove over the week 12--16 November. Eclipse on the Coral Sea: Cycle 24 Ascending served as GONG 2012, LWS/SDO-5, and SOHO 27, indicating how widely it drew on the various sub-communities within solar physics. Indeed, as we neared the end of the ascending phase of the peculiar Solar Cycle 24, it was the perfect time to bring the whole community together to discuss our Sun's errant recent behaviour, especially as Cycle 24 is the first to be fully observed by the Solar Dynamics Observatory (SDO). The whole-Sun perspective was a driving theme of the conference, with the cycle probed from interior (helioseismology), to atmosphere (the various lines observed by the Atmospheric Imaging Assemble (AIA) aboard SDO, the several instruments on Hinode, and other modern observatories), and beyond (CMEs etc). The quality of the presentations was exceptional, and the many speakers are to be commended for pitching their talks to the broad community present. These proceedings draw from the invited and contributed oral presentations and the posters exhibited in Palm Cove. They give an (incomplete) snapshot of the meeting, illustrating its broad vistas. The published contributions are organized along the lines of the conference sessions, as set out in the Contents, leading off with a provocative view of

  5. Blood velocity distribution in the human ascending aorta.

    PubMed

    Segadal, L; Matre, K

    1987-07-01

    Mapping of blood velocities across the lumen of the ascending aorta was performed in eight patients during open-heart surgery. A Doppler ultrasound probe was constructed to measure velocities in 2 mm steps from the maximum convexity to the maximum concavity of aorta, 6 to 7 cm above the aortic valve. In five patients with angina and normal aortic valves, velocity profiles were very similar and showed the following main features: a skewed peak systolic velocity profile with the highest velocity along the left posterior wall, a bidirectional velocity profile in late systole and early diastole with retrograde velocities along the left posterior wall, and a sustained antegrade flow along the convexity well into diastole. The resultant mean velocity profile had the highest velocity at the convex side and a central minimum velocity. In patients with Medtronic-Hall tilting disc prostheses, where the larger opening was oriented backwards and to the right, mean flow velocity profile was skewed in the opposite direction of normal. Moreover, instant systolic velocity profiles were much more irregular and dependent on the exact orientation of the prosthesis. In one patient with aortic valvular disease, very irregular and different velocity profiles were found. Based on a symmetry assumption, overall mean velocity for the total cross section was computed, and the magnitude of error in estimation of total flow from measurement of velocities at different depths was calculated. To measure total flow in the aorta, i.e., cardiac output, by single-gated Doppler technique, the most representative sampling site was about one-third of the diameter from the convex wall.

  6. 'Non-hypotensive' hypovolaemia reduces ascending aortic dimensions in humans

    NASA Technical Reports Server (NTRS)

    Taylor, J. A.; Halliwill, J. R.; Brown, T. E.; Hayano, J.; Eckberg, D. L.

    1995-01-01

    1. The notion that small, 'non-hypotensive' reductions of effective blood volume alter neither arterial pressure nor arterial baroreceptor activity is pervasive in the experimental literature. We tested two hypotheses: (a) that minute arterial pressure and cardiac autonomic outflow changes during hypovolaemia induced by lower body suction in humans are masked by alterations in breathing, and (b) that evidence for arterial baroreflex engagement might be obtained from measurements of thoracic aorta dimensions. 2. In two studies, responses to graded lower body suction at 0 (control), 5, 10, 15, 20 and 40 mmHg were examined in twelve and ten healthy young men, respectively. In the first, arterial pressure (photoplethysmograph), R-R interval, and respiratory sinus arrhythmia amplitude (complex demodulation) were measured during uncontrolled and controlled breathing (constant breathing frequency and tidal volume). In the second, cross-sectional areas of the ascending thoracic aorta were calculated from nuclear magnetic resonance images. 3. Lower body suction with controlled breathing resulted in an increased arterial pulse pressure at mild levels (5-20 mmHg; ANOVA, P < 0.05) and a decreased arterial pulse pressure at moderate levels (40 mmHg; ANOVA, P < 0.05). Both R-R intervals and respiratory sinus arrhythmia were negatively related to lower body suction level, whether group averages (general linear regression, r > 0.92) or individual subjects (orthogonal polynomials, 12 of 12 subjects) were assessed. 4. Aortic pulse area decreased progressively and significantly during mild lower body suction, with 47% of the total decline occurring by 5 mmHg. 5. These results suggest that small reductions of effective blood volume reduce aortic baroreceptive areas and trigger haemodynamic adjustments which are so efficient that alterations in arterial pressure escape detection by conventional means.

  7. Systematic Review of Interventions to Repair Ascending Aortic Pseudoaneurysms

    PubMed Central

    Quevedo, Henry C.; Santiago-Trinidad, Ricardo; Castellanos, Jorge; Atianzar, Kimberly; Anwar, Asif; Rafeh, Nidal Abi

    2014-01-01

    Background The safety and efficacy of endovascular therapies for ascending aortic pseudoaneurysms (AAPs) are still controversial. Methods We report an endovascular correction of an AAP in a high-risk surgical patient and present the results of a literature review focusing on AAP treatment strategies. A multilingual search of AAP therapy was performed with limiting dates of January 1980 to May 2014. The studies were classified by intervention. Results A 79-year-old male with a 9 × 10 × 7 cm AAP in the anterior mediastinum was considered too high risk for surgery. An endovascular closure with a 12 mm Amplatzer septal occluder device (St. Jude Medical) was performed, and computed tomography angiography at 3-month follow-up exhibited a thrombosed AAP with minimal residual shunt. In our literature search, we identified 355 cases of AAPs, mostly case reports (91.5%) and a few patient series (8.5%). Surgical correction accounted for 73.8% of the cases, 5% of the patients were conservatively treated or considered too critically ill for any intervention, and 21.2% were treated with endovascular techniques. The most commonly reported endovascular techniques were stent grafts (9.8%) and septal occluder devices (9.8%). Conclusion Although endovascular closure of AAPs with off-label devices is a reliable option for controlling the expansion and symptoms in high-risk surgical patients, solid data on survival are lacking. Efforts to promote discussion within the heart team to expand the application of endovascular techniques can provide groundbreaking evidence to support the use of endovascular techniques as guideline therapy when facing these complicated cases. PMID:25598723

  8. Predictive biomechanical analysis of ascending aortic aneurysm rupture potential

    PubMed Central

    Martin, Caitlin; Sun, Wei; Pham, Thuy; Elefteriades, John

    2013-01-01

    Aortic aneurysm is a leading cause of death in adults, often taking lives without any premonitory signs or symptoms. Adverse clinical outcomes of aortic aneurysm are preventable by elective surgical repair; however, identifying at-risk individuals is difficult. The objective of this study was to perform a predictive biomechanical analysis of ascending aortic aneurysm (AsAA) tissue to assess rupture risk on a patient-specific level. AsAA tissues, obtained intra-operatively from 50 patients, were subjected to biaxial mechanical and uniaxial failure tests to obtain their passive elastic mechanical properties. A novel analytical method was developed to predict the AsAA pressure-diameter response as well as the aortic wall yield and failure responses. Our results indicated that the mean predicted AsAA diameter at rupture was 5.6 ± 0.7 cm, and the associated blood pressure to induce rupture was 579.4 ± 214.8 mmHg. Statistical analysis showed significant positive correlation between aneurysm tissue compliance and predicted risk of rupture, where patients with a pressure-strain modulus ≥100 kPa may be nearly twice as likely to experience rupture than patients with more compliant aortic tissue. The mechanical analysis of pre-dissection patient tissue properties established in this study could predict the “future” onset of yielding and rupture in AsAA patients. The analysis results implicate decreased tissue compliance as a risk factor for AsAA rupture. The presented methods may serve as a basis for the development of a pre-operative planning tool for AsAA evaluation, a tool currently unavailable. PMID:23948500

  9. AGE-DEPENDENT ASCENDING AORTA MECHANICS ASSESSED THROUGH MULTIPHASE CT

    PubMed Central

    Martin, Caitlin; Sun, Wei; Primiano, Charles; McKay, Raymond; Elefteriades, John

    2013-01-01

    Quantification of the age- and gender-specific in vivo mechanical characteristics of the ascending aorta (AA) will allow for identification of abnormalities aside from changes brought on by aging alone. Multiphase clinical CT scans of 45 male patients between the ages of 30 and 79 years were analyzed to assess age-dependent in vivo AA characteristics. The three-dimensional AA geometry for each patient was reconstructed from the CT scans for 9–10 phases throughout the cardiac cycle. The AA circumference was measured during each phase and was used to determine the corresponding diameter, circumferential strain, and wall tension at each phase. The pressure-strain modulus was also determined for each patient. The mean diastolic AA diameter was significantly smaller among young (42.6±5.2 years) at 29.9±2.8 mm than old patients (69.0±5.2 years) at 33.2±3.2 mm. The circumferential AA strain from end-diastole to peak-systole decreased from 0.092±0.03 in young to 0.056±0.03 in old patients. The pressure-strain modulus increased two-fold from 68.4±30.5 kPa in young to 162.0±93.5 kPa in old patients, and the systolic AA wall tension increased from 268.5±31.3 kPa in young to 304.9±49.2 kPa in old patients. The AA dilates and stiffens with aging which increases the vessel wall tension, likely predisposing aneurysm and dissection. PMID:23817767

  10. Medullary sponge kidney presenting in a neonate with distal renal tubular acidosis and failure to thrive: a case report

    PubMed Central

    2009-01-01

    Introduction Medullary sponge kidney is a congenital anomaly characterized by diffuse ectasy of the collecting tubules of one or both kidneys. It is usually diagnosed in the second or third decade of life. Case presentation Distal renal tubular acidosis is commonly observed in patients with medullary sponge kidney. We describe here a 50-day-old Egyptian Caucasian girl with medullary sponge kidney who had features of distal renal tubular acidosis, (persistent alkaline urine, hypercalciuria, hypocitraturia) and failure to thrive. Renal ultrasound revealed left renal increased medullary echogenicity and bilateral nephrocalcinosis. Conclusion Early gene(s) expression of medullary sponge kidney disease might be responsible for persistent metabolic acidosis during the neonatal period. PMID:19830120

  11. Sporadic bilateral adrenal medullary hyperplasia: apparent false positive MIBG scan and expected MRI findings.

    PubMed

    Yung, B C; Loke, T K; Tse, T W; Tsang, M W; Chan, J C

    2000-10-01

    Adrenal medullary hyperplasia is a rare cause of clinical symptoms and biochemical findings identical to pheochromocytoma occurring mostly in multiple endocrine neoplasia patients. The scenario of positive MIBG scan, but no focal lesion found on CT and MRI led to diagnostic and management difficulties. Like pheochromocytoma, surgical excision can lead to clinical and biochemical recovery. We report this unusual case of sporadic bilateral adrenal medullary hyperplasia, with hypertension and biochemical abnormalities alleviated after surgical adrenalectomy. Based on T2 values reported in literature, high signal focal lesions may not appear on T2-weighted MRI images until development of frank pheochromocytoma. MIBG scan remains the most sensitive imaging modality for this condition.

  12. Transient hyperechogenicity of the renal medullary pyramids: incidence in the healthy term newborn.

    PubMed

    Khoory, B J; Andreis, I A; Vino, L; Fanos, V

    1999-01-01

    A screening program was performed on 1881 clinically healthy term newborns, aimed at detecting eventual pathological conditions not diagnosed during pregnancy. Seventy-three cases of transient hyperechogenicity of the renal medullary pyramids were observed, involving one or both kidneys with either sectorial or diffuse pattern. None of the neonates examined had evidence of renal dysfunction and follow-up ultrasound scans demonstrated complete resolution of the sonographic picture. Medullary hyperechogenicity is not rare in healthy term newborns (3.9%); it presents rapid resolution and should be considered in differential diagnosis of pathological conditions.

  13. Medullary cystic disease of the kidney: its occurrence in two siblings

    PubMed Central

    Handa, Satya Paul; Tennant, Robert

    1968-01-01

    Two cases of medullary cystic disease of the kidney in two siblings are presented. In both siblings there was an insidious onset of azotaemia and anaemia at an early age. The urinalyses were normal except for a trace of proteinuria and persistent low specific gravity. The kidneys were small by radiological studies and this was proved at necropsy. The gross microscopic appearances of the kidneys were consistent with medullary cystic disease. The literature on this subject and current views on the similarities between familial juvenile nephronophthisis and this condition are discussed. ImagesFig. 1Fig. 2Fig. 3Fig. 4 PMID:5705387

  14. Targeting medullary thyroid carcinomas with bispecific antibodies and bivalent haptens. Results and clinical perspectives.

    PubMed

    Rouvier, E; Gautherot, E; Meyer, P; Barbet, J

    1997-01-01

    The present article reviews the clinical trials that have been performed in recurrent medullary thyroid carcinoma patients with the Affinity Enhancement System. This technique uses bispecific antibodies to target radiolabelled bivalent haptens to tumour cells. Its sensitivity in the detection of known tumour sites is high (90%) and this technique also achieves good sensitivity (61%) in the detection of occult disease as revealed by abnormal thyrocalcitonin blood levels. Due to its high targeting capacity, this technique is now considered for use as a therapeutic agent in medullary thyroid carcinoma patients.

  15. Critical aortic stenosis and acute ascending aortic penetrating ulcer managed utilizing transapical TAVR and TEVAR.

    PubMed

    Allen, Keith B; Davis, J Russell; Cohen, David J

    2015-10-01

    Thoracic endovascular aortic repair (TEVAR) of acute ascending aortic pathology is feasible; however, the unique features of this aortic segment in addition to access challenges restricts its use to a select, high-risk subset of patients. With the advent of TAVR, large device delivery using transapical access has become a well-defined technique. We report a patient with critical aortic stenosis and an acute ascending aortic penetrating ulcer with tamponade managed successfully utilizing transapical TAVR and TEVAR. To our knowledge, this is the first reported case of a hybrid single-stage TAVR and ascending aortic TEVAR using transapical access.

  16. The effect of slice thickness on quantitation of in vivo renal volume with cine computed tomography

    SciTech Connect

    Lerman, L.O.; Bentley, M.D.; Bell, M.R.; Rumberger, J.A.; Romero, J.C. )

    1990-02-26

    The development of fast computed tomography (CT) scanners allows the accurate quantitations of the volume (V) of the in-vivo kidney (K) and its component tissues, using 3 mm thick slices. Utilizing thicker slices may potentially enable the use of shorter scan times with less exposure to contrast media. To determine the relative accuracy of such scans, the right Ks of 14 anesthetized dogs were first scanned, using 3mm thick slices, after a venous bolus injection of iohexol (0.5 cc/kg). The images were then averaged to produce 6 and 10 mm thick slices, and the Vs of the Ks, and their cortical and medullary Vs, determined after boundary identification. Following the scans, the Ks were excised and their Vs determined post-mortem by fluid displacement. The whole K Vs obtained with the 6 and 10 mm thick slices correlated well with those obtained with the 3 mm thick slices. The difference between the in vivo and the post-mortem renal and medullary Vs was consistent with the blood, filtrate and urine contents of the in vivo kidney. In conclusion, the use of 6 and 10 mm thick slices resulted in an overestimation of the in vivo cortical V due to a partial volume effect, which was reflected in a consistent overestimation of KV.

  17. Hypervascularity is more frequent in medullary thyroid carcinoma

    PubMed Central

    Lai, Xingjian; Liu, Meijuan; Xia, Yu; Wang, Liang; Bi, Yalan; Li, Xiaoyi; Zhang, Bo; Yang, Meng; Dai, Qing; Jiang, Yuxin

    2016-01-01

    Abstract This study was designed to retrospectively compare the sonographic features of medullary thyroid carcinoma (MTC) and the features of papillary thyroid carcinoma (PTC). A total of 97 patients with 127 MTCs between January 2000 and January 2016 and 107 consecutive patients with 132 PTCs were included in this study. Two radiologists retrospectively determined the sonographic features and compared the findings of MTCs and PTCs. Compared with the patients with PTCs, the patients with MTCs were older (46.9 years vs 42.9 years, P = 0.016) and the male proportion was higher (53.6% vs 33.6%, P = 0.005). Most of the MTCs had an irregular shape (72.4%), a length/width ratio <1 (75.6%), an unclear boundary (63.8%), no peripheral halo ring (93.7%), hypoechogenicity (96.9%), heterogeneous echotexture (76.4%), no cystic change (78.7%), calcification (63.8%), and hypervascularity (72.4%). There was no significant difference in the boundary, peripheral halo ring, echogenicity, and calcification between the MTCs and PTCs. However, compared with the PTCs, a larger size (2.2 vs 1.2 cm, P <0.001), a regular shape (27.6% vs 7.6%, P <0.001), a length/width ratio <1 (75.6% vs 51.5%, P<0.001), heterogeneous echotexture (76.4% vs 54.5%, P <0.001), cystic change (21.3 vs 8.3%, P = 0.005), and hypervascularity (72.4% vs 47.7%, P <0.001) were more frequent in the MTCs. The sonographic features with a higher likelihood of malignancy are common in MTCs, including a shape taller than the width, irregular infiltrative margins, an absent halo, hypoechogenicity, the presence of microcalcifications, and increased intranodular vascularity. However, MTCs tend to possess these suspicious sonographic features less often than PTCs, with the exception of hypervascularity, which was more frequent in MTCs. PMID:27930537

  18. Shear wave elastography in medullary thyroid carcinoma diagnostics

    PubMed Central

    Gumińska, Anna; Bakuła-Zalewska, Elwira; Mlosek, Krzysztof; Słapa, Rafał Z.; Wareluk, Paweł; Krauze, Agnieszka; Ziemiecka, Agnieszka; Migda, Bartosz; Jakubowski, Wiesław; Dedecjus, Marek

    2015-01-01

    Shear wave elastography (SWE) is a modern method for the assessment of tissue stiffness. There has been a growing interest in the use of this technique for characterizing thyroid focal lesions, including preoperative diagnostics. Aim The aim of the study was to assess the clinical usefulness of SWE in medullary thyroid carcinoma (MTC) diagnostics. Materials and methods A total of 169 focal lesions were identified in the study group (139 patients), including 6 MTCs in 4 patients (mean age: 45 years). B-mode ultrasound and SWE were performed using Aixplorer (SuperSonic, Aix-en-Provence), with a 4–15 MHz linear probe. The ultrasound was performed to assess the echogenicity and echostructure of the lesions, their margin, the halo sign, the height/width ratio (H/W ratio), the presence of calcifications and the vascularization pattern. This was followed by an analysis of maximum and mean Young's (E) modulus values for MTC (EmaxLR, EmeanLR) and the surrounding thyroid tissues (EmaxSR, EmeanSR), as well as mean E-values (EmeanLRz) for 2 mm region of interest in the stiffest zone of the lesion. The lesions were subject to pathological and/or cytological evaluation. Results The B-mode assessment showed that all MTCs were hypoechogenic, with no halo sign, and they contained micro- and/ or macrocalcifications. Ill-defined lesion margin were found in 4 out of 6 cancers; 4 out of 6 cancers had a H/W ratio > 1. Heterogeneous echostructure and type III vascularity were found in 5 out of 6 lesions. In the SWE, the mean value of EmaxLR for all of the MTCs was 89.5 kPa and (the mean value of EmaxSR for all surrounding tissues was) 39.7 kPa Mean values of EmeanLR and EmeanSR were 34.7 kPa and 24.4 kPa, respectively. The mean value of EmeanLRz was 49.2 kPa. Conclusions SWE showed MTCs as stiffer lesions compared to the surrounding tissues. The lesions were qualified for fine needle aspiration biopsy based on B-mode assessment. However, the diagnostic algorithm for MTC is based on the

  19. [Giant pseudoaneurysm of the ascending aorta following the aortic valve replacement;report of a case].

    PubMed

    Kawahara, Yu; Inage, Yuichi; Masaki, Naoki; Toyama, Shuji; Fukasawa, Manabu

    2013-08-01

    56-year-old male, who had undergone re-aortic valve replacement (AVR) 33 years ago, received preoperative study for pancreatic surgery. Computed tomography (CT) revealed a giant pseudoaneurysm (7 cm diameter) of the ascending aorta. The ascending aorta was not dilated. A midline skin incision was performed, followed by full sternotomy. A tight pericardial adhesion was carefully dissected. Cardiopulmonary bypass was established by femoral arterial and bicaval venous cannulation. The pseudoaneurysm was incised under the retrograde cardioplegic protection. A communication between ascending aorta and aneurysm was found 1 cm distal to the previous aortic suture line. This communication coincided with the cardioplegic root cannulation site. The aortic prosthetic valve was intact. The ascending aorta was replaced with 26 mm prosthetic graft. Postoperative course was uneventful. In this case, CT was useful to select the approach to the complicated postoperative surgical site.

  20. Combined aortic valve replacement and coronary artery bypass grafting for a calcified ascending aorta.

    PubMed

    Baba, Hironori; Umesue, Masayoshi; Matsui, Kanzi

    2012-04-01

    Although a severely calcified ascending aorta is encountered infrequently, it presents formidable problems during cardiac surgery. We describe a case of severe aortic valve stenosis and coronary artery disease combined with a severely calcified ascending aorta. The patient was an 80-year-old man with a calcified ascending aorta. He successfully underwent an aortic valve replacement and a single coronary artery bypass graft (CABG) using a saphenous vein graft with the proximal end connected on a Dacron patch, which was used for aortoplasty of the calcified plate along the aortotomy. These procedures were performed under moderate hypothermia with aortic clamping. This patch aortoplasty can be a useful alternative in cases that require aortotomy and proximal anastomoses of a CABG on a calcified ascending aorta.

  1. Acquired supravalvular aortic stenosis: a late complication of replacement of the ascending aorta.

    PubMed

    Turley, Andrew J; Dark, John; Adams, Philip C

    2008-09-01

    Aortic syndromes are an increasing cause of morbidity and mortality. Ascending aortic dissection is a clinical emergency with most patients requiring open surgery to replace the ascending aorta. Detection through clinical suspicion, improved non-invasive imaging and refined surgical techniques have resulted in an improved survival rate. Acquired supravalvular aortic stenosis is an extremely rare complication of cardiac surgery. We present the case of a patient who, 15 years after undergoing elective replacement of the ascending aorta for aortic dissection, required repeat surgery for symptomatic supravalvular aortic stenosis. This case elegantly highlights the need for a detailed focused assessment in patients where the clinical presentation does not correlate with initial investigations. To our knowledge this is the first reported case of late symptomatic supravalvular aortic stenosis following replacement of the ascending aorta.

  2. Vertical ascending electrophoresis of cells with a minimal stabilizing medium

    NASA Technical Reports Server (NTRS)

    Omenyi, S. N.; Snyder, R. S.

    1983-01-01

    Vertical fractionation of a mixture of fixed horse and human red blood cells layered over a stabilizing support medium was done to give a valid comparison with proposed space experiments. In particular, the effects of sample thickness and concentration on zone migration rate were investigated. Electrophoretic mobilities of horse and human cells calculated from zone migration rates were compatible with those obtained by microelectrophoresis. Complete cell separation was observed when low power and effective cooling were employed.

  3. Neurogenic period of ascending tract neurons in the upper lumbar spinal cord of the rat

    SciTech Connect

    Nandi, K.N.; Beal, J.A.; Knight, D.S. )

    1990-02-01

    Although the neurogenic period for neurons in the lumbar spinal cord has been clearly established (Days 12 through 16 of gestation), it is not known when the neurogenesis of ascending tract neurons is completed within this period. The purpose of the present study was to determine the duration of the neurogenic period for projection neurons of the ascending tracts. To label neurons undergoing mitosis during this period, tritiated thymidine was administered to fetal rats on Embryonic (E) Days E13 through E16 of gestation. Ascending tract neurons of the lumbar cord were later (Postnatal Days 40-50) labeled in each animal with a retrograde tracer, Fluoro-Gold, applied at the site of a hemisection at spinal cord segment C3. Ascending tract neurons which were undergoing mitosis in the upper lumbar cord were double labeled, i.e., labeled with both tritiated thymidine and Fluoro-Gold. On Day E13, 89-92% of the ascending tract neurons were double labeled; on Day E14, 35-37%; and on Day E15, 1-4%. Results showed, then, that some ascending tract neurons were double labeled through Day E15 and were, therefore, proliferating in the final one-third of the neurogenic period. Ascending tract neurons proliferating on Day E15 were confined to laminae III, IV, V, and X and the nucleus dorsalis. Long tract neurons in the superficial dorsal horn (laminae I and II), on the other hand, were found to have completed neurogenesis on Day E14 of gestation. Results of the present study show that spinal neurogenesis of ascending projection neurons continues throughout most of the neurogenic period and does not completely follow the well-established ventral to dorsal gradient.

  4. Hydrogen Sulfide Regulates the [Ca2+]i Level in the Primary Medullary Neurons

    PubMed Central

    Liu, Xiaoni; Zhang, Nana; Ding, Yingjiong; Cao, Dongqing; Huang, Ying; Chen, Xiangjun; Wang, Rui

    2016-01-01

    In the present study, we attempted to elucidate mechanisms for the regulation of intracellular calcium levels by H2S in primary rat medullary neurons. Our results showed that NaHS significantly increased the level of [Ca2+]i in rat medullary neurons in a concentration-dependent manner. L-Cysteine and SAM significantly raised the level of [Ca2+]i in the medullary neurons while HA and/or AOAA produced a reversal effect. In addition, L-cysteine and SAM significantly increased but HA and/or AOAA decreased the production of H2S in the cultured neurons. The [Ca2+]i elevation induced by H2S was significantly diminished by EGTA-Ca2+-free solutions, and this elevation was also reduced by nifedipine or nimodipine and mibefradil, suggesting the role of L-type and/or T-type Ca2+ channels. Moreover, the effect of H2S on [Ca2+]i level in neurons was significantly attenuated by BAPTA-AM and thapsigargin, suggesting the source of Ca2+. Therefore, we concluded that both exogenous and endogenous H2S elevates [Ca2+]i level in primarily cultured rat medullary neurons via both increasing calcium influx and mobilizing intracellular Ca2+ stores from ER. PMID:27840667

  5. E-cadherin and beta-catenin expression in breast medullary carcinomas.

    PubMed

    Charpin, C; Bonnier, P; Garcia, S; Andrac, L; Crebassa, B; Dorel, M; Lavaut, M N; Allasia, C

    1999-08-01

    The initial step of cancer invasion and metastasis is the escape of tumour cells from the primary site, involving disruption of normal cell-cell adhesion and E-cadherin (E-cad) and beta-catenin (beta-cat) down-regulation, as shown in various types of human malignancies including breast carcinomas. Medullary carcinomas are high grade and poorly differentiated tumours with syncytial typical pattern, and prognosis unexpectedly better than that in high grade breast carcinomas. In a series of 55 breast typical medullary carcinomas diagnosed according to the strict use of Ridolfi et al (Cancer 40: 1365-1385, 1977) criteria, E-cad and beta-cat were investigated using quantitative (SAMBA 2005 system) immunocytochemical assays on frozen sections. Results were compared to that obtained on paraffin sections and in a series (n=55) of grade 3 ductal carcinomas. It was shown that medullary carcinomas significantly (p<0.001) expressed more E-cad and beta-cat than grade 3 ductal carcinomas. E-cad and beta-cat correlated with high expression of P53, of c-erbB, and of Ki-67 antigens, and with lack of hormone receptors antigenic sites (p<0.001). It was concluded that favourable prognosis and syncytial pattern of typical breast medullary carcinomas likely results, at least partly, from a particular expression of cell-cell adhesion molecules, significantly limiting tumour growth and efficiently mastering the tumour cell dissemination, opposing to high proliferative activity (grade 3).

  6. Axon-glial relationships in the anterior medullary velum of the adult rat.

    PubMed

    Berry, M; Ibrahim, M; Carlile, J; Ruge, F; Duncan, A; Butt, A M

    1995-12-01

    The anterior medullary velum is a thin sheet of CNS tissue which roofs the rostral part of the IVth ventricle and contains fascicles of myelinated fibres which, in part, arise from the nucleus of the IVth cranial nerve. This study used histochemical, immunohistochemical, and intracellular dye-injection techniques to describe cellular interrelationships in the velum in whole-mounts and in sections. Rip antibody-stained whole mounts provided a unique description of both oligodendrocyte units (defined as an oligodendrocyte and the complement of myelinated internodal segments it forms), and consecutive myelin sheaths along the same axon. A broad range of unit morphologies was categorised into four arbitrary groups, according to classical criteria, which comprised small cells supporting the short, thin myelin sheaths of 15-30 small diameter axons (Type I), through intermediate types (II & III), to the largest cells forming the long, thick myelin sheaths of 1-3 large diameter axons. Rip antibody and ferric ion-ferrocyanide staining, together with intracellular dye injection, revealed oligodendrocyte process branching patterns and their mode of engagement of myelin sheaths, nodes of Ranvier, and the spatial disposition of the outer cytoplasmic rims of myelin sheaths. The latter formed a conspicuous spiral ridge on the exterior surface of myelin sheaths which connected with the paranodal loops at each heminode. Large bundles of axons decussated through the velum, the bulk of which were IVth nerve fibres which constituted the IVth nerve rootlet. The PNS/CNS transitional zone of the IVth nerve was located 0.25-0.50 mm along the root, where astrocytic end-feet defined an abrupt margin, convex towards the periphery, where the heminodes of central and peripheral myelin were apposed, and where the basal lamina tubes of the Schwann cell units were discontinued. The basal processes of ependymal cells lining the ventricular wall of the velum, passed between axon bundles before

  7. Relationship between myelin sheath diameter and internodal length in axons of the anterior medullary velum of the adult rat.

    PubMed

    Ibrahim, M; Butt, A M; Berry, M

    1995-11-01

    Relations between myelin sheath diameters and internodal lengths were measured in whole mounts of osmium stained intact anterior medullary velum (AMV) from glutaraldehyde perfused adult rats. The AMV is a sheet of CNS tissue which roofs the IVth ventricle and contains fascicles of myelinated fibres which arise mainly from the nucleus of the IVth cranial nerve. These fibers displayed a broad range of myelin sheath external diameters and internodal lengths, from < 1-12 microns and 50-750 microns, respectively. Myelin sheath external diameter was a measurement of the axonal diameter plus the thickness of its myelin sheath, while internodal length was measured as the distance between consecutive nodes. There was a broadly linear relationship between myelin sheath diameters and internodal lengths, with the smaller diameter sheaths tending to have shorter internodes than the larger. However, the correlation was weak and for any given diameter myelin sheaths displayed considerable variation in their internodal lengths. The smallest diameter myelin sheaths, < 4 microns, consistently had shorter internodes than predicted by a linear regression and, in an analysis of consecutive internodes in single fibres, the slope was flattened in fibres with a diameter > 4 microns. Our results indicated that small and large calibre fibres may have different myelin sheath diameter-internodal length interrelations.

  8. Diluting power of thick limbs of Henle. II. Bumetanide-sensitive /sup 22/Na+ influx in medullary vesicles

    SciTech Connect

    Reeves, W.B.; Dudley, M.A.; Mehta, P.; Andreoli, T.E.

    1988-12-01

    We evaluated the effects of osmotic gradients on 22Na+ influx in vesicles prepared from rat outer renal medulla. 22Na+ influx driven in a coflow mode by an inwardly directed 100 mM KCl gradient was measured at 20 and 60 s; 1 mM bumetanide inhibited approximately 30% of 22Na+ influx. The bumetanide-sensitive 22Na+ influx was reduced by approximately 65% when either K+ or Cl- was omitted from the aqueous phases. We found that an osmotic gradient for vesicle shrinkage, that is, 600 mM urea in the extravesicular medium, enhanced the bumetanide-sensitive 22Na+ influx twofold. Conversely, an osmotic gradient for vesicle swelling, that is, with vesicles but not extravesicular media loaded with 600 mM urea, produced a 50% suppression of bumetanide-sensitive 22Na+ influx. Moreover, 600 mM extravesicular urea, an osmotic gradient for vesicle shrinkage, also reduced uptake of the nonspecific marker (14C)mannitol. These effects of osmotic gradients were not due to alterations in ionic driving forces, since bumetanide-sensitive 22Na+ influx driven in a counterflow mode by loading the vesicles with 100 mM NaCl also was activated or suppressed by osmotic gradients for vesicle shrinkage or swelling, respectively. We conclude that osmotic gradients, and/or vesicle volume changes, modulate bumetanide-sensitive Na+:K+:2Cl- activity.

  9. Factors influencing the ascending limb of the sarcomere length-tension relationship in rabbit skinned muscle fibres.

    PubMed Central

    Allen, J D; Moss, R L

    1987-01-01

    1. The length dependence of Ca2+-activated tension within the ascending limb of the length-tension relationship, corresponding to sarcomere lengths below about 2.25 micron, was investigated in skinned fibres from rabbit psoas muscle. At high [Ca2+] a shallow phase and then a steep phase of tension decline were observed as sarcomere length was reduced, while at low [Ca2+] tension decreased monotonically with decreases in sarcomere length. The sarcomere length at which the ascending limb intersected zero tension was greater for lower concentrations of Ca2+. 2. The length tension relationship from maximally activated fibres changed when filament lattice spacing was reduced by osmotic compression. Relationships obtained in the presence of 5% (w/v) dextran T500 more distinctly demonstrated both the shallow and steep portions of the ascending limb than did relationships from untreated fibres. 3. As striation spacing was decreased a progressive decline in the Ca2+ sensitivity of tension development was observed. Tension-pCa relationships from both control and dextran-treated fibres underwent a rightward shift (i.e. to a higher [Ca2+]) by 0.23 pCa units as sarcomere length was reduced between 2.46 and 1.54 microns. 4. Fibre stiffness was studied by applying a 3.3 kHz sinusoidal length change at one end of the fibre and measuring the resultant tension change. At submaximal activation (pCa 5.8), stiffness increased relative to tension as sarcomere length was decreased below approximately 2.4 microns, suggesting that there is an activation-related internal load at low [Ca2+]. At maximal activation, a significant increase in this ratio occurred only at sarcomere lengths less than approximately 1.8 microns, and presumably involved collision of the thick filaments with the Z-lines. 5. Length-dependent changes in the Ca2+ sensitivity of tension development do not appear to be the result of shortening-induced dissociation of Ca2+ from troponin-C, the Ca2+ binding subunit of

  10. Bicuspid aortic valve: theoretical and clinical aspects of concomitant ascending aorta replacement.

    PubMed

    De Sá, Mauro Paes Leme; Bastos, Eduardo Sergio; Murad, Henrique

    2009-01-01

    Bicuspid aortic valve (BAV) is associated with annuloaortic ectasia, dissection and ascending aortic aneurysm. The high incidence of this congenital malformation and aortic disease suggests a close correlation between the two phenomena. Abnormalities in different phases of cell migration of the neural crest might be responsible for the occurrence of abnormalities in the aortic valve, media layer of the ascending aorta and vessels of the aortic arch. Previous studies have shown that patients with normal BAV or slight dysfunction may present with dilation of the aortic root. The hemodynamic changes caused by BAV without stenosis or insufficiency seem to be an insufficient explanation for these findings. Several mechanisms have been proposed to explain the molecular and hystological aspects of this disease. We found a reduced fibrillin-1 content in both ascending aorta and pulmonary trunk as a possible cause. Histologically, the ascending aorta can present cystic medial necrosis and elastic fragmentation, similar to Marfan's disease. Some authors concluded that many patients, mainly those with aortic regurgitation, should have the aortic valve and the ascending aorta replaced at the same procedure, even if a mild dilatation (45 mm) is present in patients with BAV if life expectancy is anticipated to be greater than 10 years to prevent further aneurysms or ruptures.

  11. Influences of initial launch conditions on flight performance of high altitude balloon ascending process

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; Liu, Dongxu

    2015-08-01

    Influences of initial launch conditions on flight performance are addressed for the high altitude balloon ascending process. A novel dynamic model was established to describe thermodynamic and kinetic characteristics of balloon which consists of atmospheric, thermal and dynamic submodels. Based on the model, ascending processes of a high altitude balloon under different initial launch conditions were simulated. The initial launch conditions were classified into three types: inflating quantity, launch time and launch position. The ascending velocity and the differential pressure were defined and used as evaluation parameters of flight performance. Results showed that the inflating quantity is the most effective factor for ascending process, and the upper and lower limits were also proposed separately from safety and performance perspectives. For both launch time and launch location conditions, different solar radiation is the main effect approach during ascending process. Specifically, the influence mechanism of launch time in one day and launch longitude are completely identical due to the Earth's rotation. Results also showed that the sunset process is the optimal selection for safety of balloon and efficient utilization of solar energy. Due to the Earth's revolution, the influence mechanism of launch date and launch latitude are identical and the effects are more seasonal and less effective. Launch time and location should be considered comprehensively in practical operation of ballooning.

  12. [Interlocking medullary nailing. Indications, technic with a new guiding instrument. Analysis of the 1st 50 operations].

    PubMed

    Berentley, G

    1976-01-01

    After a review of Küntsher's intramedullary nailing, the author resumed the informations about the interlocking medullary nail and its technique. A new device, as a guide instrument for easier application of the transverse bolts was constructed on the basis of authors concept. Using the new technique and guide instrument X-ray television controll is not necessary for placing the bolts in their right places through a small incision. The time of operation and the risk of infection was also diminished by the new technique. The indications for the interlocking medullary nailing have been completed by the author with the pathologic fractures. The first 50 cases, treated by the new technique of the interlocking medullary nailing are analysed and a few cases are reported in detail. Good results have been obtained as regards both the bone union and the functional results. Based on the good results the new technique of the interlocking medullary nailing is recommended by the author.

  13. Spastic quadriparesis caused by anomalous vertebral artery compression of spinal cord at the cervico-medullary junction.

    PubMed

    Betgeri, Somsharan Shankerappa; Rajesh, S; Adkatalwar, Vijayendra; Shiva, Meyyappan; Agrawal, Nitesh; Ramakrishnan, K G

    2015-02-01

    Vascular compression of medulla or spinal cord at the cervico-medullary junction has been commonly described in the literature and is often attributed to dolichoectasia of the vertebrobasilar arteries. We describe a case of anomalous course of the cervical segments of the bilateral vertebral arteries which were seen entering the spinal canal directly after exiting the transverse foramen of axis and causing significant cord compression at the cervico-medullary region leading to spastic quadriparesis.

  14. Increased dietary sodium induces COX2 expression by activating NFκB in renal medullary interstitial cells.

    PubMed

    He, Wenjuan; Zhang, Min; Zhao, Min; Davis, Linda S; Blackwell, Timothy S; Yull, Fiona; Breyer, Matthew D; Hao, Chuan-Ming

    2014-02-01

    High salt diet induces renal medullary cyclooxygenase 2 (COX2) expression. Selective blockade of renal medullary COX2 activity in rats causes salt-sensitive hypertension, suggesting a role for renal medullary COX2 in maintaining systemic sodium balance. The present study characterized the cellular location of COX2 induction in the kidney of mice following high salt diet and examined the role of NFκB in mediating this COX2 induction in response to increased dietary salt. High salt diet (8 % NaCl) for 3 days markedly increased renal medullary COX2 expression in C57Bl/6 J mice. Co-immunofluorescence using a COX2 antibody and antibodies against aquaporin-2, ClC-K, aquaporin-1, and CD31 showed that high salt diet-induced COX2 was selectively expressed in renal medullary interstitial cells. By using NFκB reporter transgenic mice, we observed a sevenfold increase of luciferase activity in the renal medulla of the NFκB-luciferase reporter mice following high salt diet, and a robust induction of enhanced green fluorescent protein (EGFP) expression mainly in renal medullary interstitial cells of the NFκB-EGFP reporter mice following high salt diet. Treating high salt diet-fed C57Bl/6 J mice with selective IκB kinase inhibitor IMD-0354 (8 mg/kg bw) substantially suppressed COX2 induction in renal medulla, and also significantly reduced urinary prostaglandin E2 (PGE2). These data therefore suggest that renal medullary interstitial cell NFκB plays an important role in mediating renal medullary COX2 expression and promoting renal PGE2 synthesis in response to increased dietary sodium.

  15. Increased Dietary Sodium Induces COX2 Expression by activating NFκB in Renal Medullary Interstitial Cells

    PubMed Central

    Zhao, Min; Davis, Linda S.; Blackwell, Timothy S.; Yull, Fiona; Breyer, Matthew D.; Hao, Chuan-Ming

    2013-01-01

    High salt diet induces renal medullary COX2 expression. Selective blockade of renal medullary COX2 activity in rats causes salt sensitive hypertension, suggesting a role for renal medullary COX2 in maintaining systemic sodium balance. The present study characterized the cellular location of COX2 induction in the kidney of mice following high salt diet and examined the role of NFκB in mediating this COX2 induction in response to increased dietary salt. High salt diet (8% NaCl) for 3 days markedly increased renal medullary COX2 expression in C57Bl/6J mice. Co-immunofluorescence using a COX2 antibody and antibodies against AQP2, ClC-K, AQP1 and CD31 showed that high salt diet-induced COX2 was selectively expressed in renal medullary interstitial cells. By using NFκB reporter transgenic mice, we observed a 7 fold increase of luciferase activity in the renal medulla of the NFκB-luciferase reporter mice following high salt diet, and a robust induction of EGFP expression mainly in renal medullary interstitial cells of the NFκB-EGFP reporter mice following high salt diet. Treating high salt diet fed C57Bl/6J mice with selective IκB kinase inhibitor IMD-0354 (8mg/kg bw) substantially suppressed COX2 induction in renal medulla, and also significantly reduced urinary PGE2. These data therefore suggest that renal medullary interstitial cell NFκB plays an important role in mediating renal medullary COX2 expression and promoting renal PGE2 synthesis in response to increased dietary sodium. PMID:23900806

  16. A rare case of medullary carcinoma of the colon presenting as intussusception in an adult with rectal bleeding.

    PubMed

    Jain, Shilpa; Jain, Ankur; Onizuka, Neil; Boukhar, Sarag A

    2014-11-01

    Medullary carcinoma is a recently recognized rare subtype of colorectal cancer resembling both poorly differentiated adenocarcinoma and neuroendocrine tumors. Medullary carcinoma most commonly presents in the proximal colon and can be differentiated from other right-sided malignant lesions by histology and immunochemical markers. We present here a rare case of an adult patient with rectal bleeding who was found to have an intussusception due to underlying medullary carcinoma of the splenic flexure. A 72-year-old woman presented to our GI clinic with rectal bleeding. Colonoscopy revealed a necrotic mass of the sigmoid colon, later determined by CT to be a colo-colonic intussusception at the level of the splenic flexure. Patient underwent diagnostic laparoscopy with findings of a large splenic flexure mass, which was resected and found to be medullary carcinoma of the colon. The tumor was poorly differentiated and exhibited microsatellite instability but was discovered at an early stage and thus did not require any adjuvant chemotherapy. Unlike most previously reported cases of medullary carcinoma, our patient presented with a left sided tumor. To our knowledge, this is the first report of a medullary colon cancer presenting with intussusception.

  17. Impact of nitric-oxide-mediated vasodilation and oxidative stress on renal medullary oxygenation: a modeling study

    PubMed Central

    Fry, Brendan C.; Edwards, Aurélie

    2015-01-01

    The goal of this study was to investigate the effects of nitric oxide (NO)-mediated vasodilation in preventing medullary hypoxia, as well as the likely pathways by which superoxide (O2−) conversely enhances medullary hypoxia. To do so, we expanded a previously developed mathematical model of solute transport in the renal medulla that accounts for the reciprocal interactions among oxygen (O2), NO, and O2− to include the vasoactive effects of NO on medullary descending vasa recta. The model represents the radial organization of the vessels and tubules, centered around vascular bundles in the outer medulla and collecting ducts in the inner medulla. Model simulations suggest that NO helps to prevent medullary hypoxia both by inducing vasodilation of the descending vasa recta (thus increasing O2 supply) and by reducing the active sodium transport rate (thus reducing O2 consumption). That is, the vasodilative properties of NO significantly contribute to maintaining sufficient medullary oxygenation. The model further predicts that a reduction in tubular transport efficiency (i.e., the ratio of active sodium transport per O2 consumption) is the main factor by which increased O2− levels lead to hypoxia, whereas hyperfiltration is not a likely pathway to medullary hypoxia due to oxidative stress. Finally, our results suggest that further increasing the radial separation between vessels and tubules would reduce the diffusion of NO towards descending vasa recta in the inner medulla, thereby diminishing its vasoactive effects therein and reducing O2 delivery to the papillary tip. PMID:26831340

  18. Pneumorrhachis Resulting in Transient Paresis after PICC Line Insertion into the Ascending Lumbar Vein.

    PubMed

    Payne, Russell; Sieg, Emily P; Choudhary, Arabinda; Iantosca, Mark

    2016-10-17

    Obtaining intravascular access in the neonatal intensive care unit (NICU) is not only critical but also technically challenging. Malposition of the catheter tip is a known and well-documented complication. Specifically, peripherally inserted central venous catheter (PICC) line insertion into the ascending lumbar vein can lead to neurological dysfunction and, in some cases, even death. We present the first reported case of pneumorrhachis (PR) following PICC line insertion into the ascending lumbar vein. Our patient presented with lower extremity weakness and imaging confirmed the presence of air within the spinal canal. After conservative treatment, the strength deficit resolved and subsequent imaging revealed resolution of the air within the spinal canal. Insertion of central venous catheters into the ascending lumbar vein is a well-documented complication that can lead to neurologic injury and even death. This should be considered in the evaluation of any neonate presenting with an abnormal neurological examination or unexplained change in exam after line insertion.

  19. Developmental salivary gland depression in the ascending mandibular ramus: A cone-beam computed tomography study

    PubMed Central

    Chen, Christine A.; Ahn, Yoonhee; Odell, Scott; Graham, David Mattew

    2016-01-01

    A static, unilateral, and focal bone depression located lingually within the ascending ramus, identical to the Stafne's bone cavity of the angle of the mandible, is being reported. During development of the mandible, submandibular gland inclusion may lead to the formation of a lingual concavity, which could contain fatty tissue, blood vessels, or soft tissue. However, similar occurrences in the ascending ramus at the level of the parotid gland are extremely rare. Similar cases were previously reported in dry, excavated mandibles, and 3 cases were reported in living patients. A 52-year-old African American male patient was seen for pain in the mandibular teeth. Panoramic radiography showed an unusual concavity within the left ascending ramus. Cone-beam computed tomography confirmed this incidental finding. The patient was cleared for the extraction of non-restorable teeth and scheduled for annual follow-up. PMID:27672619

  20. Management of bicuspid aortic valve with or without involvement of ascending aorta and aortic root.

    PubMed

    Neragi-Miandoab, S

    2014-06-01

    Patients with a bicuspid aortic valve (BAV) constitute a heterogeneous population with variable clinical presentation and complications. More than 50% of the patients who require aortic valve replacement have a BAV, a condition that may be associated with dilation of ascending aorta and aortic insufficiency caused by cusp disease or aortic root pathology. Of the potential BAV-related complications, dilation of the aortic root and ascending aorta are among the most serious. The dilation of ascending aorta and aortic root have been the subject of controversy. Whereas some surgeons believe that the dilation of the aorta is caused by the hemodynamic properties of the BAV, others believe that the dilation of the aortic root is secondary to genetic defects associated with the BAV. Management of a BAV should be tailored to each patient's clinical condition. The surgical approach varies from aortic valve replacement to combined aortic valve and root replacement to aortic-valve-sparing root replacement.

  1. Causes and histopathology of ascending aortic disease in children and young adults

    PubMed Central

    Jain, Deepali; Dietz, Harry C.; Oswald, Gretchen L.; Maleszewski, Joseph J.; Halushka, Marc K.

    2011-01-01

    Background Ascending aortic diseases (aneurysms, dissections, and stenosis) and associated aortic valve disease are rare but important causes of morbidity and mortality in children and young adults. Certain genetic causes, such as Marfan syndrome and congenital bicuspid aortic valve disease, are well known. However, other rarer genetic and nongenetic causes of aortic disease exist. Methods We performed an extensive literature search to identify known causes of ascending aortic pathology in children and young adults. We catalogued both aortic pathologies and other defining systemic features of these diseases. Results We describe 17 predominantly genetic entities that have been associated with thoracic aortic disease in this age group. Conclusions While extensive literature on the common causes of ascending aortic disease exists, there is a need for better histologic documentation of aortic pathology in rarer diseases. PMID:19926309

  2. Glioblastoma multiforme in conus medullaris with intracranial metastasis after postoperative adjuvant therapy

    PubMed Central

    Yan, Chengrui; Kong, Xiangyi; Yin, Hua; Wang, Yu; He, Huayu; Zhang, Hui; Gao, Jun; Li, Yongning; Ma, Wenbin

    2017-01-01

    Abstract Spinal glioblastoma multiforme is not common among spinal cord tumors. According to our literature review, only 27 cases originating from the conus medullaris were reported. We herein reported a case of a 10-year-old child diagnosed with glioblastoma multiforme. The patient received adjuvant radiotherapy and standard temozolomide chemotherapy after total excision. Intracranial lesions were found 1 month after postoperative adjuvant therapy. We described the clinical characteristics and postoperative therapy of the patient, and reviewed all of the published cases of conus medullaris glioblastoma. Location, age, leptomeningeal spread, and secondary hydrocephalus may be predictive factors. Immunohistochemical factors such as p53 and Ki-67 are also important. Combined treatment of surgery and postoperative adjuvant therapy is commonly used, but is controversial. PMID:28353599

  3. Modulation of pressure-natriuresis by renal medullary reactive oxygen species and nitric oxide.

    PubMed

    O'Connor, Paul M; Cowley, Allen W

    2010-04-01

    The renal pressure-natriuresis mechanism is the dominant controller of body fluid balance and long-term arterial pressure. In recent years, it has become clear that the balance of reactive oxygen and nitrogen species within the renal medullary region is a key determinant of the set point of the renal pressure-natriuresis curve. The development of renal medullary oxidative stress causes dysfunction of the pressure-natriuresis mechanism and contributes to the development of hypertension in numerous disease models. The purpose of this review is to point out the known mechanisms within the renal medulla through which reactive oxygen and nitrogen species modulate the pressure-natriuresis response and to update the reader on recent advances in this field.

  4. Sleep and dream suppression following a lateral medullary infarct: a first-person account.

    PubMed

    Allan Hobson, J

    2002-09-01

    Consciousness can be studied only if subjective experience is documented and quantified, yet first-person accounts of the effects of brain injury on conscious experience are as rare as they are potentially useful. This report documents the alterations in waking, sleeping, and dreaming caused by a lateral medullary infarct. Total insomnia and the initial suppression of dreaming was followed by the gradual recovery of both functions. A visual hallucinosis during waking that was associated with the initial period of sleep and dream suppression is described in detail. Since the changes in sleep and their recovery are comparable to results of animal experiments, it can be concluded that damage to the medullary brain stem causes extreme but short-lived alterations in conscious state and that substantial recovery occurs even though the damage to the brain stem endures.

  5. Revised American Thyroid Association Guidelines for the Management of Medullary Thyroid Carcinoma

    PubMed Central

    Asa, Sylvia L.; Dralle, Henning; Elisei, Rossella; Evans, Douglas B.; Gagel, Robert F.; Lee, Nancy; Machens, Andreas; Moley, Jeffrey F.; Pacini, Furio; Raue, Friedhelm; Frank-Raue, Karin; Robinson, Bruce; Rosenthal, M. Sara; Santoro, Massimo; Schlumberger, Martin; Shah, Manisha; Waguespack, Steven G.

    2015-01-01

    Introduction: The American Thyroid Association appointed a Task Force of experts to revise the original Medullary Thyroid Carcinoma: Management Guidelines of the American Thyroid Association. Methods: The Task Force identified relevant articles using a systematic PubMed search, supplemented with additional published materials, and then created evidence-based recommendations, which were set in categories using criteria adapted from the United States Preventive Services Task Force Agency for Healthcare Research and Quality. The original guidelines provided abundant source material and an excellent organizational structure that served as the basis for the current revised document. Results: The revised guidelines are focused primarily on the diagnosis and treatment of patients with sporadic medullary thyroid carcinoma (MTC) and hereditary MTC. Conclusions: The Task Force developed 67 evidence-based recommendations to assist clinicians in the care of patients with MTC. The Task Force considers the recommendations to represent current, rational, and optimal medical practice. PMID:25810047

  6. Perfusion weighted imaging in the assessment of the pathology and outcomes of lateral medullary infarction

    PubMed Central

    Zhang, Dao P.; Zhang, Hong T.; Yin, Suo; Yan, Fu L.

    2016-01-01

    This series case report aimed to elucidate the underlying pathology and outcomes of lateral medullary infarction (LMI) using perfusion weighted imaging (PWI). Four patients were diagnosed with LMI based on high-field diffusion-weighted magnetic resonance imaging (MRI-DWI) and PWI. The national institutes of health stroke scale (NIHSS) scores were recorded on days 1, 7, and 30, and the Barthel index was assessed on days 7 and 30. Three patients exhibited relative regional hypoperfusion of medullary lesion in the perfusion maps. Two cases exhibited ipsilateral hypoperfusion in the inferior cerebellum, whereas one patient exhibited a relatively regional hyperperfusion in the medulla oblongata. The LMI patients with a high NIHSS score and low Barthel index on days 7 and 30 exhibited regional hypoperfusion. This report of 4 LMI cases provides preliminary evidence that regional hypoperfusion may contribute to worse outcomes in LMI. PMID:27744467

  7. Methodology and dosimetry in adrenal medullary imaging with iodine-131 MIBG

    SciTech Connect

    Lindberg, S.; Fjaelling, M.J.; Jacobsson, L.; Jansson, S.; Tisell, L.E.

    1988-10-01

    Iodine-131 MIBG scans were performed in 59 patients in order to localize intra- or extra-adrenal pheochromocytomas (pheos), or to visualize hyperplastic adrenal medulla. Images were obtained from the pelvis to the base of the skull on Days 1, 4, and 7 after tracer injection. The 15 patients with histopathologic confirmation of adrenal medullary disease had positive scans. In three of these, the pheos were visible only on images obtained on Day 7. One scan was false negative. After excluding patients with a predisposition to adrenal medullary disease, nine subjects (28%) without verification of pheo displayed adrenal uptake of the radionuclide. Late images produce a low rate of false-negative scans; the background activity diminishes and even small pheos can be detected. In order to increase the quality of late images, 40 MBq (/sup 131/I)MIBG was used instead of 20 MBq. The dosimetric considerations are discussed.

  8. Paroxysmal sneezing at the onset of lateral medullary syndrome: cause or consequence?

    PubMed

    Swenson, A J; Leira, E C

    2007-04-01

    Sneezing is known to precede lateral medullary syndrome (LMS). It is usually interpreted as the precipitating cause for a vertebral artery dissection that subsequently causes LMS. Through two case reports and a literature review, we aim to challenge the concept that sneezing at the onset of LMS implies that a dissection is the underlying cause. An 82-year-old man and a 54-year-old man both reported unprovoked explosive pathological sneezing at the onset of the LMS without any delay between sneezing and the other LMS symptoms. Both denied neck trauma or neck pain. There was no conclusive evidence for vertebral artery dissection in either case. Paroxysmal sneezing can be an initial manifestation of lateral medullary ischemia and may not necessarily indicate an underlying vertebral artery dissection as the cause.

  9. Renal medullary carcinoma as an incidental finding in a horseshoe kidney: case report and literature review.

    PubMed

    Molgat, Gilles; Afrouzian, Marjan; Trpkov, Kiril

    2005-10-01

    Renal medullary carcinoma is rare and extremely aggressive neoplasm that typically affects young patients of African decent who demonstrate sickle cell trait or disease. Since the original description in 1995, only few cases have been reported outside the United States. A 29 year-old Canadian male of Afro-Caribbean decent with sickle cell trait developed right-sided hemiparesis due to brain infarct. During the clinical work-up, a 3 cm renal tumor was detected in a horseshoe kidney. The patient died suddenly 2 weeks after the presentation of massive non-neoplastic pulmonary thromboembolism, confirmed at autopsy. The final diagnosis of renal medullary carcinoma was established after the autopsy. Due to the small size of the tumor and the limited metastatic spread only to the regional lymph nodes, the tumor was considered an incidental finding, and not the primary cause of patient's death.

  10. Effect of hypocapnia on ventral medullary blood flow and pH during hypoxia in cats

    SciTech Connect

    Davies, D.G.; Nolan, W.F.; Sexton, J.A.

    1986-07-01

    Ventral medullary blood flow was measured in 33 chloralose-urethan-anesthetized cats during 60 min of isocapnia-hypoxia, mild hypocapnia-hypoxia, or severe hypocapnia-hypoxia. In an additional group of six animals the pH of ventral medullary extracellular fluid (ECF) was determined during mild hypocapnia-hypoxia. The increase in blood flow during hypoxia was reduced by mild hypocapnia and eliminated by severe hypocapnia. With the exception of an initial decrease in ECF H(+) concentration, which occurred during the first 10 min of mild hypocapnia-hypoxia, ECF H(+) concentration increased progressively throughout the exposure and recovery periods and was significantly elevated from the control value by the first 10 min of the recovery period. The results suggest that hypocapnia affects the hypoxic cerebrovascular response of the ventral medulla and that this phenomenon could affect the regulation of ventral medudllary ECF H(+) concentration. 17 references.

  11. The imaging assessment and specific endograft design for the endovascular repair of ascending aortic dissection

    PubMed Central

    Zhang, Yepeng; Tang, Hanfei; Zhou, JianPing; Liu, Zhao; Liu, Changjian; Qiao, Tong; Zhou, Min

    2016-01-01

    Background Endovascular option has been proposed for a very limited and selected number of Stanford type A aortic dissection (TAAD) patients. We have performed a computed tomography (CT)-based TAAD study to explore appropriate endograft configurations for the ascending aortic pathology. Methods TAAD patients treated with optimal CT scans were retrospectively reviewed, and their entry tears (ETs) were identified using three-dimensional and multiplanar reconstructions in an EndoSize workstation. After generating a centerline of flow, measurements, including numerous morphologic characteristics of anatomy, were evaluated and a selected subset of patients were determined to be suitable for endovascular treatments. Proximal diameter and distal diameter of endograft were selected based on diameters measured at the ET level and at the innominate artery (IA) level, with 10% oversizing with respect to the true lumen, but not exceeding the original aortic diameter. The length of the endograft was determined by the distance from the sinotubular junction to IA. Results This study covered 126 TAAD patients with primary ET in ascending aorta, among which, according to the assumed criteria, 48 (38.1%) patients were deemed to be suitable for endovascular treatment. The diameters of ascending aorta from the sinotubular junction to the IA level presented a downward trend, and the proximal diameters differed significantly from distal diameters of the endograft for TAAD (39.9 versus 36.2 mm, P<0.01), implying that the conical endograft might be compatible with the ascending pathology. In the ascending aorta, lengths of the endograft should be 50, 60, 70, 80, and 90 mm in five (10.4%), 22 (45.9%), 13 (27.1%), six (12.5%), and two (4.2%) patients, respectively. Conclusion In this selected number of Chinese patients, the suitability of endovascular repair has been demonstrated based on the CT imaging. Shorter, larger, and bare spring-free conical endografts were preferred in the

  12. Biomechanical characterization of ascending aortic aneurysm with concomitant bicuspid aortic valve and bovine aortic arch.

    PubMed

    Pham, T; Martin, C; Elefteriades, J; Sun, W

    2013-08-01

    Studies have shown that patients harboring bicuspid aortic valve (BAV) or bovine aortic arch (BAA) are more likely than the general population to develop ascending aortic aneurysm (AsAA). A thorough quantification of the AsAA tissue properties for these patient groups may offer insights into the underlying mechanisms of AsAA development. Thus, the objective of this study was to investigate and compare the mechanical and microstructural properties of aortic tissues from AsAA patients with and without concomitant BAV or BAA. AsAA (n=20), BAV (n=20) and BAA (n=15) human tissues were obtained from patients who underwent elective AsAA surgery. Planar biaxial and uniaxial failure tests were used to characterize the mechanical and failure properties of the tissues, respectively. Histological analysis was performed to detect medial degenerative characteristics of aortic aneurysm. Individual layer thickness and composition were quantified for each patient group. The circumferential stress-strain response of the BAV samples was stiffer than both AsAA (p=0.473) and BAA (p=0.152) tissues at a low load. The BAV samples were nearly isotropic, while AsAA and BAA samples were anisotropic. The areal strain of BAV samples was significantly less than that of AsAA (p=0.041) and BAA (p=0.004) samples at a low load. The BAA samples were similar to the AsAA samples in both mechanical and failure properties. On the microstructural level, all samples displayed moderate medial degeneration, characterized by elastin fragmentation, cell loss, mucoid accumulation and fibrosis. The ultimate tensile strength of BAV and BAA sampleswere also found to decrease with age. Overall, the BAV samples were stiffer than both AsAA and BAA samples, and the BAA samples were similar to the AsAA samples. The BAV samples were thinnest, with less elastin than AsAA and BAA samples, which may be attributed to the loss of extensibility of these tissues at a low load. No apparent difference in failure mechanics among

  13. Renal medullary ETB receptors produce diuresis and natriuresis via NOS1.

    PubMed

    Nakano, Daisuke; Pollock, Jennifer S; Pollock, David M

    2008-05-01

    Endothelin-1 (ET-1) plays an important role in the regulation of salt and water excretion in the kidney. Considerable in vitro evidence suggests that the renal medullary ET(B) receptor mediates ET-1-induced inhibition of electrolyte reabsorption by stimulating nitric oxide (NO) production. The present study was conducted to test the hypothesis that NO synthase 1 (NOS1) and protein kinase G (PKG) mediate the diuretic and natriuretic effects of ET(B) receptor stimulation in vivo. Infusion of the ET(B) receptor agonist sarafotoxin S6c (S6c: 0.45 microg x kg(-1) x h(-1)) in the renal medulla of anesthetized, male Sprague-Dawley rats markedly increased the urine flow (UV) and urinary sodium excretion (UNaV) by 67 and 120%, respectively. This was associated with an increase in medullary cGMP content but did not affect blood pressure. In addition, S6c-induced diuretic and natriuretic responses were absent in ET(B) receptor-deficient rats. Coinfusion of N(G)-propyl-l-arginine (10 microg x kg(-1) x h(-1)), a selective NOS1 inhibitor, suppressed S6c-induced increases in UV, UNaV, and medullary cGMP concentrations. Rp-8-Br-PET-cGMPS (10 microg x kg(-1) x h(-1)) or RQIKIWFQNRRMKWKK-LRK(5)H-amide (18 microg x kg(-1) x h(-1)), a PKG inhibitor, also inhibited S6c-induced increases in UV and UNaV. These results demonstrate that renal medullary ET(B) receptor activation induces diuretic and natriuretic responses through a NOS1, cGMP, and PKG pathway.

  14. Long-term measurement of renal cortical and medullary tissue oxygenation and perfusion in unanesthetized sheep.

    PubMed

    Calzavacca, Paolo; Evans, Roger G; Bailey, Michael; Lankadeva, Yugeesh R; Bellomo, Rinaldo; May, Clive N

    2015-05-15

    The role of renal cortical and medullary hypoxia in the development of acute kidney injury is controversial, partly due to a lack of techniques for the long-term measurement of intrarenal oxygenation and perfusion in conscious animals. We have, therefore, developed a methodology to chronically implant combination probes to chronically measure renal cortical and medullary tissue perfusion and oxygen tension (tPO2) in conscious sheep and evaluated their responsiveness and reliability. A transit-time flow probe and a vascular occluder were surgically implanted on the left renal artery. At the same operation, dual fiber-optic probes, comprising a fluorescence optode to measure tPO2 and a laser-Doppler probe to assess tissue perfusion, were inserted into the renal cortex and medulla. In recovered conscious sheep (n = 8) breathing room air, mean 24-h cortical and medullary tPO2 were similar (31.4 ± 0.6 and 29.7 ± 0.7 mmHg, respectively). In the renal cortex and medulla, a 20% reduction in renal blood flow (RBF) decreased perfusion (14.6 ± 8.6 and 41.2 ± 8.5%, respectively) and oxygenation (48.1 ± 8.5 and 72.4 ± 8.5%, respectively), with greater decreases during a 50% reduction in RBF. At autopsy, minimal fibrosis was observed around the probes. In summary, we have developed a technique to chronically implant fiber-optic probes in the renal cortex and medulla for recording tissue perfusion and oxygenation over many days. In normal resting conscious sheep, cortical and medullary tPO2 were similar. The responses to and recovery from renal artery occlusion, together with the consistent measurements over a 24-h period, demonstrate the responsiveness and stability of the probes.

  15. Acute increases of renal medullary osmolality stimulate endothelin release from the kidney.

    PubMed

    Boesen, Erika I; Pollock, David M

    2007-01-01

    Experiments conducted in vitro suggest that high osmolality stimulates endothelin production and release by renal tubular epithelial cells. Whether hyperosmotic solutions exert similar effects in vivo is unknown. Therefore, we tested the hypothesis that increasing renal medullary osmolality enhances urinary excretion of endothelin in anesthetized rats. Isosmotic NaCl (284 mosmol/kgH(2)O) was infused either intravenously (1.5 ml/h) or into the renal medullary interstitium (0.5 ml/h) during a 1-h equilibration period and 30-min baseline urine collection period, followed by either isosmotic or hyperosmotic NaCl (921 or 1,664 mosmol/kgH(2)O iv; 1,714 mosmol/kgH(2)O into renal medulla) for two further 30-min periods. Compared with isosmotic NaCl, infusion of hyperosmotic NaCl into the renal medulla significantly increased the endothelin excretion rate (P < 0.05; from 0.30 +/- 0.02 to 0.49 +/- 0.03 fmol/min). Intravenous infusion of hyperosmotic NaCl also significantly increased endothelin excretion rate in a concentration-dependent manner (from 0.79 +/- 0.07 to 1.77 +/- 0.16 fmol/min and 0.59 +/- 0.04 to 1.11 +/- 0.08 fmol/min for 1,664 and 921 mosmol/kgH(2)O, respectively). To differentiate between effects of osmolality and NaCl, similar experiments were performed using mannitol solutions. Compared with isosmotic mannitol, medullary interstitial infusion of hyperosmotic mannitol (1,820 mosmol/kgH(2)O) significantly increased endothelin excretion rate (P < 0.05; from 0.54 +/- 0.03 to 0.94 +/- 0.12 fmol/min). Thus exposing the renal medulla to hyperosmotic concentrations of either NaCl or mannitol stimulates endothelin release in vivo, consistent with medullary osmolality being an important regulator of renal endothelin synthesis.

  16. An investigation of the conus medullaris termination level during the period of fetal development to adulthood.

    PubMed

    Malas, M A; Salbacak, A; Büyükmumcu, M; Seker, M; Köylüoğlu, B; Karabulut, A K

    2001-10-01

    The spinal cord fills the length of the vertebral canal at the early period of intrauterine term. It is reported to extend to the level of the third lumbar vertebra at birth, because the vertebral column is growing more rapidly in the longitudinal direction than the spinal cord. The present investigation aimed to determine the changes in the termination level of conus medullaris (TLCM) from fetus to adulthood in a total of 285 individuals who had no defects in the central or peripheral nervous system, and were obtained from our Faculties of Medicine and Konya Maternity Hospital between 1992-1995. The age distribution was as follows: 36 fetuses, 20 prematures and 50 neonates, 51 children aged 1 to 7 years and 128 adults aged 15 to 68 years. In this study, for fetuses, prematures, neonates and children the TLCM was determined using ultrasonography. In addition, microdissection was used in fetuses to confirm the results obtained from the above technique. Also, magnetic resonance imaging was used in adults. During fetal life the end of the conus altered its levels from S5 to L3 vertebrae. The tip of the conus medullaris of the prematures and neonates ranged from L1 to L3 vertebrae. The tip of the conus medullaris in the children lay between the Th12 and L3 vertebrae, and in the adults it was between the Th12 and L2 vertebrae. There were slight differences between the prematures and neonates in terms of the TLCM. We concluded that there are differences in the TLCM between the age groups and therefore, especially in prematures and infants the determination of the tip of conus medullaris might be important for preventing postoperative neurological complications.

  17. [Medullary layer activity of the rat adrenals after a flight on the Kosmos-1129 biosatellite].

    PubMed

    Kvetnanský, R; Blazicek, P; Tigranian, R A

    1982-01-01

    After a 18.5-day space flight on Cosmos-1129 rat adrenals were investigated for the concentration of catecholamines and activity of enzymes involved in their synthesis, i.e. tyrosine hydroxylase, dopamine-beta-hydroxylase, and phenyl ethanol amine-N-methyl transferase. It was found that inflight the sympatho-adreno-medullary system of rats was not exposed to a prolonged or strong stressogenic effect. Postflight the rats showed an increased reactivity to the immobilization stress.

  18. Medullary nephrocalcinosis and pancreatic calcifications demonstrated by ultrasound and CT in infants after treatment with ACTH

    SciTech Connect

    Rausch, H.P.; Hanefield, F.; Kaufmann, B.J.

    1984-10-01

    Thirteen patients who had undergone prolonged adrenocorticotropic hormone (ACTH) therapy for infantile spasms or encephalopathy were examined with sonography. Nine patients were seen to have appearances characteristic of medullary nephrocalcinosis. Five patients also showed a homogeneously increased echogenicity of the whole pancreas on sonography, and one of these showed increased density on computed tomography. Density measurements were in the range of calcific arterial within the papillae and pancreatic tissue. On abdominal survey radiographs, even in retrospect, no calcifications could be recognized.

  19. Huge dissected ascending aorta associated with pseudo aneurysm and aortic coarctation feridoun.

    PubMed

    Sabzi, Feridoun; Khosravi, Donya

    2015-07-01

    We report a unique case of chronic dissection of the ascending aorta complicated with huge and thrombotic pseudoaneurysm in a patient with coarctation of descending aorta. Preoperative investigations such as transesophageal echocardiography (TEE) confirmed the diagnosis of dissection. Intraoperative findings included a12 cm eccentric bulge of the right lateral side of dilated the ascending aorta filled with the clot and a circular shaped intimal tear communicating with an extended hematoma and dissection of the media layer. The rarity of the report is an association of the chronic dissection with huge pseudoaneurysm and coarctation. The patient underwent staged repair of an aneurysm and coarctation and had an uneventful postoperative recovery period.

  20. Diagnosis of pseudoaneurysm of the ascending aorta by pulsed Doppler cross sectional echocardiography.

    PubMed Central

    Wendel, C H; Cornman, C R; Dianzumba, S B

    1985-01-01

    Pseudoaneurysms of the ascending aorta are relatively uncommon compared with those evolving from the left ventricle. In a young man with endocarditis of the aortic valve who developed a pseudoaneurysm arising from the ascending aorta, the diagnosis was established with the pulsed Doppler technique and cross sectional echocardiography by passing the Doppler sample from the aorta through the neck of the false aneurysm into the large pseudoaneurysm. Aortic root angiography showed this connexion to be a small fistula between the aorta and right atrium. Necropsy findings confirmed the diagnosis. Images PMID:3994873

  1. How Could These Mini Saccular Aneurysms of Ascending Aorta Be Classified?

    PubMed

    Sarraj, Anas; Muñoz, Daniel-Edgardo; Calle Valda, Corazón-Mabel; Monguio, Emilio; Reyes, Guillermo

    2017-04-01

    The wall of a true aneurysm is composed of all histologic layers of the aorta. A false aneurysm represents a small, contained rupture of aorta followed by bulging of the corresponding area that is usually sustained by a fibrous peel. Aortic dissection is defined as a separation of the lamellae of the aortic wall. Herein, we describe an unusual clinical presentation of aortic dissection in a 37-year-old male patient that presented severe aortic regurgitation and unusual bulges with linear intimal fissures in ascending aorta underwent mechanical aortic valve replacement and interposition of tubular vascular graft in ascending aorta.

  2. Floating Thrombus in the Ascending Aorta of the Patient with Systemic Sclerosis - A case report -

    PubMed Central

    Lee, Sub; Cho, Jun-woo

    2011-01-01

    Aortic thrombi are important because it can cause the central and peripheral embolizations. Aortic thrombi can occur anywhere in the aorta but extremely rare in ascending aorta without atherosclerosis, aneurysm, cardiosurgical or traumatic state. Systemic sclerosis (SSc) is an autoimmune disorder of connective tissue and it can involve multisystem. Enhanced coagulation pathways, decreased fibrinolysis, and endothelial dysfunction probably contribute to vascular events in SSc. We report a case of a highly mobile thrombus in the ascending aorta, presented as an acute embolic stroke in the patient with systemic sclerosis. Surgical removal was performed to prevent recurrent embolic events. PMID:22263129

  3. Ruptured penetrating ulcer of the ascending aorta with pulmonary artery compression.

    PubMed

    Okiwelu, Ngozichukwuka; Finn, Chris; Vanden Driesen, Rohan; Sanders, Lucas; Joshi, Pragnesh

    2016-03-01

    Pulmonary artery involvement has been reported in various degrees of complicated dissection of the ascending aorta. The prognosis remains poor without high-risk surgical intervention, but conservative management can be considered in high-risk cases. We report a case of nonoperative management of an octogenarian who presented with a contained rupture of his proximal ascending aorta, likely from a penetrating atherosclerotic ulcer. It was complicated by extrinsic compression of the pulmonary trunk and transient pulmonary hypertension without features of acute right heart failure. He remained alive at the one-year follow-up.

  4. Ascending and descending particle flux from hydrothermal plumes at Endeavour Segment, Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Cowen, James P.; Bertram, Miriam A.; Wakeham, Stuart G.; Thomson, Richard E.; William Lavelle, J.; Baker, Edward T.; Feely, Richard A.

    2001-04-01

    Bio-acoustic surveys and associated zooplankton net tows have documented anomalously high concentrations of zooplankton within a 100 m layer above the hydrothermal plumes at Endeavour Segment, Juan de Fuca Ridge. These and other data suggest that congregating epi-plume zooplankton are exploiting a food substrate associated with the hydrothermal plume. Ascending, organic-rich particles could provide a connection. Consequently, two paired sequentially sampling ascending and descending particle flux traps and a current meter were deployed on each of three moorings from July 1994 to May 1995. Mooring sites included an on-axis site (OAS; 47°57.0'N, 129°05.7'W) near the main Endeavour vent field, a "down-current" site 3 km west of the main vent field (WS), and a third background station 43 km northeast of the vent field (ES). Significant ascending and descending particle fluxes were measured at all sites and depths. Lipid analyses indicated that ascending POC was derived from mid-depth and deep zooplankton whereas descending POC also contained a component of photosynthetically derived products from the sea surface. Highest ascending POC fluxes were found at the hydrothermal plume-swept sites (OAS and WS). The limited data available, however, precludes an unequivocal conclusion that hydrothermal processes contribute to the ascending flux of organic carbon at each site. Highest ascending to descending POC flux ratios were also found at WS. Observed trends in POC, PMn/PTi, and PFe/PTi clearly support a hydrothermal component to the descending flux at the plume-swept WS site (no descending data was recovered at OAS) but not at the background ES site. Alternative explanations for ascending particle data are discussed. First-order calculations for the organic carbon input (5-22 mg C m -2 d -1) required to sustain observed epi-plume zooplankton anomalies at Endeavour are comparable both to measured total POC flux to epi-plume depths (2-5 mg C m -2 d -1: combined hydrothermal

  5. Characterization of the Immunochemical Forms of Calcitonin Released by a Medullary Thyroid Carcinoma in Tissue Culture

    PubMed Central

    Goltzman, David; Tischler, Arthur S.

    1978-01-01

    Immunoreactive calcitonin released by a medullary thyroid carcinoma in tissue culture has been found to exhibit heterogeneity when analyzed by gel chromatography and radioimmunoassay, in a pattern analogous to that seen in the circulation of the patient from whom the neoplasm was removed. To examine the cause of the heterogeneity, the immunoreactive material released by the tumor into tissue culture medium was further analyzed by gel electrophoresis in the presence of the protein denaturant 8 M urea, by gel chromatography after reduction and alkylation, by affinity chromatography on concanavalin A-agarose, and by bioassay in a renal adenylyl cyclase system of enhanced sensitivity. The results suggest that the larger immunochemical forms of calcitonin described in the circulation of patients with medullary thyroid carcinoma may be released directly from the neoplasm and need not derive from peripheral metabolism of the monomer. It could be demonstrated that a major proportion of the immunochemical enlargement is dependent upon intermolecular disulfide bridge formation whereas aggregation or non-convalent protein binding account for a smaller component of the heterogeneity. In view of the absence of binding of the immunoreactive material to the lectin agarose, carbohydrate side chains, at least of the α-d glucosyl variety, do not seem to contribute significantly to calcitonin enlargement. Additionally, the studies indicate that, at least by in vitro assay, the larger immunochemical forms of calcitonin, representing the majority of the immunoreactivity released by a medullary thyroid carcinoma, are biologically inactive. PMID:621283

  6. Adrenal Medullary Grafts Restore Olfactory Deficits and Catecholamine Levels of 6-OHDA Amygdala Lesioned Animals

    PubMed Central

    Fernández-Ruiz, Juan; Guzmán, Rubén; Martínez, María Dolores; Miranda, María Isabel; Bermúdez-Rattoni, Federico; Drucker-Colín, René

    1993-01-01

    Aside from motor and cognitive deficits, Parkinson patients also manifest a little-studied olfactory deficit. Since in Parkinson's disease there is a dopamine depletion of the amygdala due to mesocorticolimbic system degeneration, we decided to test olfactory and taste performance of 6-OHDA amygdala lesioned rats, as well as the possible restoration of either function with adrenal medullary transplants. Two 6-OHDA lesioned groups and one control group were tested in the potentiation of odor by taste aversion paradigm. On taste aversion none of the groups showed any impairment. In contrast, the 6-OHDA lesioned rats showed a marked impairment in olfactory aversion. At this point, one of the lesioned groups received a bilateral adrenal medullary graft within the lesioned area. After two months, all groups were submitted again to the behavioral paradigm. Taste remained unaffected, but the lesioned only group did not recover either olfactory aversion or normal catecholamine levels. The grafted group, on the other hand, restored olfactory aversion and catecholamine levels. It can be concluded from this study that catecholamine depletion of the amygdala is sufficient to produce a selective olfactory deficit, not accompanied by taste impairments, and that such a deficit can be reversed by adrenal medullary transplants, which in turn restore catecholamine levels. PMID:7948179

  7. Cyst of the medullary conus: malformative persistence of terminal ventricle or compressive dilatation?

    PubMed

    Celli, Paolo; D'Andrea, Giancarlo; Trillò, Giuseppe; Roperto, Raffaelino; Acqui, Michele; Ferrante, Luigi

    2002-03-01

    The ventriculus terminalis is a cavity situated at the level of the conus medullaris, enclosed by ependymal tissue and normally present as a virtual cavity or as a mere ependymal residue. In rare cases, and almost exclusively in pediatric age, the ventriculus terminalis may be visualized by radiological investigations, either by sonography or MRI, and represents a transient finding in children under 5 years of age. In pathological conditions, a cyst of the conus medullaris is probably the result of a persistent ventriculus terminalis and is usually described in children in association with a tethered cord; in a very limited number of cases, it has been described in adults whose clinical symptoms consist of neurological and/or sphincter disturbances not associated with other pathologies. The authors describe the case of a 42-year-old female with a cyst of the conus whose only symptom was imperious minction; she had been suffering from these urinary disorders for many years. The patient was not operated on because the clinical situation remained stable, without modifications of the MRI in follow-up over a 6-year period. The authors therefore suggest that in adult patients, a cyst of the conus medullaris is probably an expression of malformative persistence of the fifth ventricle and does not necessarily have a progressive evolution.

  8. Intermittent pneumatic soft tissue compression: Changes in periosteal and medullary canal blood flow.

    PubMed

    Park, Sang-Hyun; Silva, Mauricio

    2008-04-01

    We previously demonstrated that the use of intermittent pneumatic soft tissue compression (IPC) treatment enhanced fracture healing in an animal model, but the exact mechanism remained unknown. The purpose of this study was to determine the local and remote effects of IPC treatment on blood flow within the medullary canal and outside the periosteum of mid-tibial diaphysis. Blood flow was measured with a Laser Doppler blood flow meter in the lower limbs of 21 rabbits. Laser probes were inserted at three different sites of the mid-diaphysis on the right tibia: in the medullary canal (n = 21), outside the periosteum on the lateral side (n = 11), and outside the periosteum on the medial side (n = 10). IPC was applied for 30 min through cuffs that were placed around the feet and the lower part of the calf. While applying IPC to the left leg, no changes in blood flow occurred on the right leg (remote changes). However, while applying IPC to the right leg, significant localized changes were found on the right leg, including 47 and 89% increases in total amount of blood flow outside the lateral and medial periosteum, respectively. Although an altered blood flow pattern was observed in the medullary canal, no significant change in total amount of blood flow was observed at this level. In summary, the present study demonstrated that the use of IPC in an intact bone model results in a significant local increase in total blood flow, with minimal measurable effects on the contralateral limb.

  9. [Two cases with unilateral lateral medullary infarction associated with central respiratory failure].

    PubMed

    Arai, Noritoshi; Obuchi, Maiko; Matsuhisa, Akiyuki; Takahashi, Yuji; Takatsu, Masami

    2008-05-01

    We reported two patients with unilateral lateral medullary infarction involving severe, long-term respiratory failure. The first patient is an 86-year-old man presenting with gait disturbance, hoarseness and dysphagia. A right lateral medullary infarction was revealed by brain MRI. On the fifth hospitalized day, acute respiratory failure occurred. His condition failed to recover, and he was still attached to a ventilator 10 months after the onset. The second patient is an 83-year-old woman mainly presenting with dysphagia. A tiny infarction in the right lateral medulla was revealed by brain MRI. On the third day after the onset, acute respiratory failure occurred, which was not changed even at 8 months later. Although the symptoms and the lesion in the medulla were quite different between two patients, dysphagia and respiratory failure occurred in both patients. Therefore, it is postulated that the lesion that causes dyspnea may be approximate to the lesion that causes dysphagia. Many previously reported cases presenting respiratory failure seemed to suffer swallowing difficulty as well. We conclude that elderly patients suffering from unilateral lateral medullary infarction with dysphagia can present respiratory failure a few days after the onset, demonstrating the need to observe them under intensive attention.

  10. The unique organization of filamentous actin in the medullary canal of the medulla oblongata.

    PubMed

    Tan, Bai-Hong; Guo, Chun-Yan; Xiong, Tian-Qing; Chen, Ling-Meng; Li, Yan-Chao

    2017-01-24

    In the central canal, F-actin is predominantly localized in the apical region, forming a ring-like structure around the circumference of the lumen. However, an exception is found in the medulla oblongata, where the apical F-actin becomes interrupted in the ventral aspect of the canal. To clarify the precise localization of F-actin, the fluorescence signals for F-actin were converted to the peroxidase/DAB reaction products in this study by a phalloidin-based ultrastructural technique, which demonstrated that F-actin is located mainly in the microvilli and terminal webs in the ependymocytes. It is because the ventrally oriented ependymocytes do not possess well-developed microvilli or terminal web that led to a discontinuous labeling of F-actin in the medullary canal. Since spinal motions can change the shape and size of the central canal, we next examined the cytoskeletons in the medullary canal in both rats and monkeys, because these two kinds of animals show different kinematics at the atlanto-occipital articulation. Our results first demonstrated that the apical F-actin in the medullary canal is differently organized in the animals with different head-neck kinemics, which suggests that the mechanic stretching of spinal motions is capable of inducing F-actin reorganization and the subsequent cell-shape changes in the central canal.

  11. Osmolar regulation of endothelin-1 production by rat inner medullary collecting duct.

    PubMed Central

    Kohan, D E; Padilla, E

    1993-01-01

    Recent evidence has implicated endothelin-1 (ET-1) as an autocrine inhibitor of inner medullary collecting duct (IMCD) sodium and water transport. The regulators of IMCD ET-1 production are, however, largely unknown. Because of the unique hypertonic environment of the IMCD, the effect of varying extracellular tonicity on IMCD ET-1 production was evaluated. Increasing media osmolality from 300 to 450 mosmol with NaCl or mannitol but not urea caused a marked dose- and time-dependent reduction in ET-1 release by and ET-1 mRNA in cultured rat IMCD cells. In contrast, increasing osmolality had no effect on ET-1 production by rat endothelial or mesangial cells. To see if ET-1 varies in a similar manner in vivo, ET-1 production was assessed in volume expanded (lower medullary tonicity) or volume depleted (high medullary tonicity) rats. Urinary ET-1 excretion and inner medulla ET-1 mRNA were significantly reduced in volume depleted as compared to volume expanded animals. These results indicate that extracellular sodium concentration inhibits ET-1 production specifically in IMCD cells. We speculate that extracellular sodium concentration, via regulation of ET-1 production, provides a link between volume status and IMCD sodium and water reabsorption. PMID:8450052

  12. Clinicopathologic features and long-term outcome of patients with medullary breast carcinoma managed with breast-conserving therapy (BCT)

    SciTech Connect

    Ha Vu-Nishino; Tavassoli, Fattaneh A.; Ahrens, Willam A.; Haffty, Bruce G. . E-mail: hafftybg@umdnj.edu

    2005-07-15

    Purpose: The purpose of this study is to compare the clinical characteristics and outcome of medullary carcinoma to infiltrating ductal carcinoma of the breast in a large cohort of conservatively managed patients with long-term follow-up. Methods and Materials: Chart records of patients with invasive breast cancer managed with breast-conserving therapy (BCT) at the therapeutic radiology facilities of Yale University School of Medicine before 2001 were reviewed. Forty-six cases (1971-2001) were identified with medullary histology; 1,444 patients with infiltrating ductal carcinoma served as a control group. Results: The medullary cohort presented at a younger age with a higher percentage of patients in the 35 years or younger age group (26.1% vs. 6.6%, p < 0.00001). Twelve patients with medullary histology underwent genetic screening, and 6 patients were identified with deleterious mutations. This group showed greater association with BRCA1/2 mutations compared with screened patients in the control group (50.0% vs. 15.8%, p 0.0035). The medullary cohort was also significantly associated with greater T stage and tumor size (37.0% vs. 17.2% T2, mean size 3.2 vs. 2.5 cm, p 0.00097) as well as negative ER (84.9% vs. 37.6%, p < 0.00001) and PR (87.5% vs. 48.1%, p = 0.00001) status. As of February 2003, median follow-up times for the medullary and control groups were 13.9 and 14.0 years, respectively. Although breast relapse-free rates were not significantly different (76.7% vs. 85.2%), 10-year distant relapse-free survival in the medullary cohort was significantly better than in the control group (94.9% vs. 77.5%, p = 0.028). Conclusions: Despite poor clinicopathologic features, patients with medullary histology demonstrate favorable long-term distant relapse-free survival. Local control rates of patients with medullary and infiltrating ductal carcinoma are comparable. These findings suggest that patients diagnosed with medullary carcinoma are appropriate candidates for

  13. In vivo diffusion tensor imaging of chronic spinal cord compression : a rat model with special attention to the conus medullaris.

    PubMed

    Zhao, Peng; Kong, Chao; Chen, Xueming; Guan, Hua; Yu, Zhenshan; Cui, Libin; Wang, Yanhui; Yuan, Xin

    2016-12-01

    Background Few studies have focused on diffusion tensor imaging (DTI) parameters of the conus medullaris after chronic compression in the cervical spinal cord. Purpose To discuss the correlation of DTI parameters between the chronically compressed cervical spinal cord and the conus medullaris in a rat model at different time points. Material and Methods Fifty female Sprague-Dawley rats were randomized into five groups: control group (group A), sham group (group B), and test groups C, D, and E (1, 2, and 3 weeks after compression, respectively). Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values of the cervical spinal cord and conus medullaris were compared among different groups. Correlations of ADC and FA values of the cervical spinal cord with those of the conus medullaris were performed in all groups. Results The ADC values at the cervical spinal cord and conus medullaris in all test groups were higher than those of group A and B, while the FA values were lower. The ADC value of the cervical spinal cord was linearly correlated with that of the conus medullaris only in group D. There were no linear correlations of FA values between the cervical spinal cord and the conus medullaris in all test groups. Conclusion After compression of the cervical spinal cord, ADC values of the cervical spinal cord and conus medullaris in test group were significantly increased, while FA values were significantly decreased. The ADC value of the cervical spinal cord was linearly correlated with that of the conus medullaris at 2 weeks after compression.

  14. An Exploratory Study of the Ascendancy of Women to the Position of K-12 Superintendent

    ERIC Educational Resources Information Center

    Hanson, Karen M.

    2011-01-01

    Despite earning over half of the doctoral degrees in education, women are underrepresented in the position of K-12 superintendent. In 2000, although 72% of all classroom teachers were female, only 14% of all superintendents in the United States were women. Research indicates that women experience barriers in their ascendancy to superintendent.…

  15. [A Case of Pseudo-Meigs Syndrome Associated with Metachronous Ovarian Metastasis from Ascending Colon Cancer].

    PubMed

    Yachi, Takafumi; Nishikawa, Shinsuke; Tokura, Tomohisa; Iwama, Masahiro; Akaishi, Takanobu; Umehara, Minoru; Umehara, Yutaka; Murata, Akihiko; Takahashi, Kenichi; Morita, Takayuki

    2015-10-01

    We experienced a case of pseudo-Meigs syndrome associated with metachronous metastasis to the ovary from ascending colon cancer. A 65-year-old woman underwent curative surgery for ascending colon cancer at another hospital. A follow-up CT carried out 3 months after the surgery revealed a right ovarian tumor and a large amount of ascites. The patient was diagnosed with ovarian metastasis from ascending colon cancer with carcinomatous peritonitis. Palliative care was recommended, and she presented at our department for a second opinion. In spite of a large amount of ascites and pleural effusion, no disseminating tumor was detected on contrast-enhanced CT at our hospital, and we recommended that she undergo a diagnostic laparotomy. The laparotomy was negative for carcinomatous peritonitis and a right oophorectomy was performed. The histopathological findings indicated that the ovarian tumor was consistent with metastasis from ascending colon cancer. After the surgery, we initiated chemotherapy with mFOLFOX6+bevacizumab and the symptoms were well controlled. A follow-up CT carried out 11 months after the surgery revealed a left ovarian tumor and increased ascites, and the patient underwent a left oophorectomy. Then, chemotherapy with the same regimen was administered for 12 months, and she did not develop any signs of recurrence for 27 months after the surgery. Ovarian metastasis from colon cancer may occasionally cause pseudo-Meigs syndrome, and it is important to be aware of the usefulness of oophorectomy for the control of ascites and pleural effusion.

  16. Current Indications for Surgical Repair in Patients with Bicuspid Aortic Valve and Ascending Aortic Ectasia

    PubMed Central

    Etz, Christian D.; Misfeld, Martin; Borger, Michael A.; Luehr, Maximilian; Strotdrees, Elfriede; Mohr, Friedrich-Wilhelm

    2012-01-01

    Preventive surgical repair of the moderately dilated ascending aorta/aortic root in patients with bicuspid aortic valve (BAV) is controversial. Most international reference centers are currently proposing a proactive approach for BAV patients with a maximum ascending aortic/root diameter of 45 mm since the risk of dissection/rupture raises significantly with an aneurysm diameter >50 mm. Current guidelines of the European Society of Cardiology (ESC) and the joint guidelines of the American College of Cardiology (ACC)/American Heart Association (AHA) recommend elective repair in symptomatic patients with dysfunctional BAV (aortic diameter ≥45 mm). In asymptomatic patients with a well-functioning BAV, elective repair is recommended for diameters ≥50 mm, or if the aneurysm is rapidly progressing (rate of 5 mm/year), or in case of a strong family history of dissection/rupture/sudden death, or with planned pregnancy. As diameter is likely not the most reliable predictor of rupture and dissection and the majority of BAV patients may never experience an aortic catastrophe at small diameters, an overly aggressive approach almost certainly will put some patients with BAV unnecessarily at risk of operative and early mortality. This paper discusses the indications for preventive, elective repair of the aortic root, and ascending aorta in patients with a BAV and a moderately dilated—or ectatic—ascending aorta. PMID:23050195

  17. Seawifs Technical Report Series. Volume 2: Analysis of Orbit Selection for Seawifs: Ascending Versus Descending Node

    NASA Technical Reports Server (NTRS)

    Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Gregg, Watson W.

    1992-01-01

    Due to range safety considerations, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) ocean color instrument may be required to be launched into a near-noon descending node, as opposed to the ascending node used by the predecessor sensor, the Coastal Zone Color Scanner (CZCS). The relative importance of ascending versus descending near-noon orbits was assessed here to determine if descending node will meet the scientific requirements of SeaWiFS. Analyses focused on ground coverage, local times of coverage, solar and viewing geometries (zenith and azimuth angles), and sun glint. Differences were found in the areas covered by individual orbits, but were not important when taken over a 16 day repeat time. Local time of coverage was also different: for ascending node orbits the Northern Hemisphere was observed in the morning and the Southern Hemisphere in the afternoon, while for descending node orbits the Northern Hemisphere was observed in the afternoon and the Southern in the morning. There were substantial differences in solar azimuth and spacecraft azimuth angles both at equinox and at the Northern Hemisphere summer solstice. Negligible differences in solar and spacecraft zenith angles, relative azimuth angles, and sun glint were obtained at the equinox. However, large differences were found in solar zenith angles, relative azimuths, and sun glint for the solstice. These differences appeared to compensate across the scan, however, an increase in sun glint in descending node over that in ascending node on the western part of the scan was compensated by a decrease on the eastern part of the scan. Thus, no advantage or disadvantage could be conferred upon either ascending node or descending node for noon orbits. Analyses were also performed for ascending and descending node orbits that deviated from a noon equator crossing time. For ascending node, afternoon orbits produced the lowest mean solar zenith angles in the Northern Hemisphere, and morning orbits produced

  18. Lead Thickness Measurements

    SciTech Connect

    Rucinski, R.; /Fermilab

    1998-02-16

    The preshower lead thickness applied to the outside of D-Zero's superconducting solenoid vacuum shell was measured at the time of application. This engineering documents those thickness measurements. The lead was ordered in sheets 0.09375-inch and 0.0625-inch thick. The tolerance on thickness was specified to be +/- 0.003-inch. The sheets all were within that thickness tolerance. The nomenclature for each sheet was designated 1T, 1B, 2T, 2B where the numeral designates it's location in the wrap and 'T' or 'B' is short for 'top' or 'bottom' half of the solenoid. Micrometer measurements were taken at six locations around the perimeter of each sheet. The width,length, and weight of each piece was then measured. Using an assumed pure lead density of 0.40974 lb/in{sup 3}, an average sheet thickness was calculated and compared to the perimeter thickness measurements. In every case, the calculated average thickness was a few mils thinner than the perimeter measurements. The ratio was constant, 0.98. This discrepancy is likely due to the assumed pure lead density. It is not felt that the perimeter is thicker than the center regions. The data suggests that the physical thickness of the sheets is uniform to +/- 0.0015-inch.

  19. Blood flow characteristics in the ascending aorta after TAVI compared to surgical aortic valve replacement.

    PubMed

    Trauzeddel, Ralf Felix; Löbe, Ulrike; Barker, Alex J; Gelsinger, Carmen; Butter, Christian; Markl, Michael; Schulz-Menger, Jeanette; von Knobelsdorff-Brenkenhoff, Florian

    2016-03-01

    Ascending aortic blood flow characteristics are altered after aortic valve surgery, but the effect of transcatheter aortic valve implantation (TAVI) is unknown. Abnormal flow may be associated with aortic and cardiac remodeling. We analyzed blood flow characteristics in the ascending aorta after TAVI in comparison to conventional stented aortic bioprostheses (AVR) and healthy subjects using time-resolved three-dimensional flow-sensitive cardiovascular magnetic resonance imaging (4D-flow MRI). Seventeen patients with TAVI (Edwards Sapien XT), 12 with AVR and 9 healthy controls underwent 4D-flow MRI of the ascending aorta. Target parameters were: severity of vortical and helical flow pattern (semiquantitative grading from 0 = none to 3 = severe) and the local distribution of systolic wall shear stress (WSSsystole). AVR revealed significantly more extensive vortical and helical flow pattern than TAVI (p = 0.042 and p = 0.002) and controls (p < 0.001 and p = 0.001). TAVI showed significantly more extensive vortical flow than controls (p < 0.001). Both TAVI and AVR revealed marked blood flow eccentricity (64.7 and 66.7%, respectively), whereas controls showed central blood flow (88.9%). TAVI and AVR exhibited an asymmetric distribution of WSSsystole in the mid-ascending aorta with local maxima at the right anterior aortic wall and local minima at the left posterior wall. In contrast, controls showed a symmetric distribution of WSSsystole along the aortic circumference. Blood flow was significantly altered in the ascending aorta after TAVI and AVR. Changes were similar regarding WSSsystole distribution, while TAVI resulted in less helical and vortical blood flow.

  20. Identification of Reference Genes for Quantitative RT-PCR in Ascending Aortic Aneurysms

    PubMed Central

    Henn, Dominic; Bandner-Risch, Doris; Perttunen, Hilja; Schmied, Wolfram; Porras, Carlos; Ceballos, Francisco; Rodriguez-Losada, Noela; Schäfers, Hans-Joachim

    2013-01-01

    Hypertension and congenital aortic valve malformations are frequent causes of ascending aortic aneurysms. The molecular mechanisms of aneurysm formation under these circumstances are not well understood. Reference genes for gene activity studies in aortic tissue that are not influenced by aortic valve morphology and its hemodynamic consequences, aortic dilatation, hypertension, or antihypertensive medication are not available so far. This study determines genes in ascending aortic tissue that are independent of these parameters. Tissue specimens from dilated and undilated ascending aortas were obtained from 60 patients (age ≤70 years) with different morphologies of the aortic valve (tricuspid undilated n = 24, dilated n = 11; bicuspid undilated n = 6, dilated n = 15; unicuspid dilated n = 4). Of the studied individuals, 36 had hypertension, and 31 received ACE inhibitors or AT1 receptor antagonists. The specimens were obtained intraoperatively from the wall of the ascending aorta. We analyzed the expression levels of 32 candidate reference genes by quantitative RT-PCR (RT-qPCR). Differential expression levels were assessed by parametric statistics. The expression analysis of these 32 genes by RT-qPCR showed that EIF2B1, ELF1, and PPIA remained constant in their expression levels in the different specimen groups, thus being insensitive to aortic valve morphology, aortic dilatation, hypertension, and medication with ACE inhibitors or AT1 receptor antagonists. Unlike many other commonly used reference genes, the genes EIF2B1, ELF1, and PPIA are neither confounded by aortic comorbidities nor by antihypertensive medication and therefore are most suitable for gene expression analysis of ascending aortic tissue. PMID:23326585

  1. Thick film hydrogen sensor

    DOEpatents

    Hoffheins, Barbara S.; Lauf, Robert J.

    1995-01-01

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors.

  2. Thick film hydrogen sensor

    DOEpatents

    Hoffheins, B.S.; Lauf, R.J.

    1995-09-19

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors. 8 figs.

  3. Education and "Thick" Epistemology

    ERIC Educational Resources Information Center

    Kotzee, Ben

    2011-01-01

    In this essay Ben Kotzee addresses the implications of Bernard Williams's distinction between "thick" and "thin" concepts in ethics for epistemology and for education. Kotzee holds that, as in the case of ethics, one may distinguish between "thick" and "thin" concepts of epistemology and, further, that this distinction points to the importance of…

  4. Ascending and descending reflex motor activity of recto-anal region-cholinergic and nitrergic implications in a rat model.

    PubMed

    Radomirov, Radomir; Ivancheva, Christina; Brading, Alison F; Itzev, Dimitar; Rakovska, Angelina; Negrev, Negrin

    2009-04-29

    The implications of cholinergic and nitrergic transmissions in ascending and descending reflex motor pathways of recto-anal region in rat model were evaluated using: (i) electrical stimulation; (ii) triple organ bath; and (iii) morphological techniques. Electrical stimulation to anal canal induced simultaneous ascending contractile responses of longitudinal and circular muscles of proximal rectum, local contraction of anal canal or contraction followed by relaxation of internal anal sphincter when external sphincter was dissected off. The stimulation of proximal rectum elicited local contractions of both rectal layers and descending contractions of internal sphincter or anal canal. Tetrodotoxin (0.1 microM) prevented the electrically elicited events. The ascending excitatory responses and the local and ascending contractions of longitudinal muscle were more pronounced than those of circular muscle suggesting dominant role of ascending reflex pathways and of longitudinal muscle in rectal motor activity. Choline acetyltransferase (ChAT)-containing fibres and nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase-positive neurons were observed in myenteric ganglia of rectum and anal canal. NG-nitro-l-arginine (0.5mM) increased the contractile ascending and descending responses. During atropine (0.3 microM) treatment the ascending and descending contractions were suppressed but not abolished and a relaxation revealed in ascending response of circular muscle and in descending responses of internal anal sphincter and anal canal. The relaxation was decreased by NG-nitro-l-arginine and increased by l-arginine (0.5mM). The results suggest that cholinergic excitatory ascending and descending pathways and nitric oxide-dependent inhibitory ascending neurotransmission(s) to rectal circular muscle and inhibitory descending to internal anal sphincter and anal canal are involved in reflex circuitry controlling motor activity of recto-anal region.

  5. Prognostic Influence of Clinical and Pathological Factors in Medullary Thyroid Carcinoma: A Study of 53 Cases

    PubMed Central

    Brandão, Lenine G.; Cavalheiro, Beatriz G.; Junqueira, Consuelo R.

    2009-01-01

    OBJECTIVES AND INTRODUCTION Medullary thyroid carcinoma, a neoplasia of intermediate prognosis and differentiation, does not always respond predictably to known treatments. This study aimed to correlate the clinical progression of surgically treated patients with clinical and pathological data. METHODS A total of 53 patients were followed for 75 months (mean average) in tertiary-care hospital. The clinical status of patients at the end of the study period was characterized to determine correlations with a range of disease aspects. A value of p < 0.05 was considered statistically significant. RESULTS Twenty-two patients (41.5%) were alive and disease-free at the end of the follow-up period; twenty-three patients (43.4%) had persistent disease; and eight patients (15.1%) had recurrent disease. Four patients (7.6%) died from medullary thyroid carcinoma with clinical and/or imaging evidence of neoplasia. The following aspects demonstrated statistically significant correlations with the final medical condition: positive initial cervical examination (p = 0.002); neoplastic extensions to the thyroid capsule (p = 0.004) and adjacent tissues (p = 0.034); cervical lymph node metastases (p < 0.001); diameter of neoplasia (p = 0.018); TNM (tumor, node and metastasis) Stage (p = 0.001) and evidence of distant and/or cervical diseases in the absence of a cure (p = 0.011). Through logistic regression, the presence of cervical lymph node metastases was considered an independent variable (p < 0.001). CONCLUSIONS Clinical and pathological aspects of patients with surgically treated medullary thyroid carcinomas are predictors of disease progression. Specifically, even treated cervical lymph node metastases are significantly correlated with disease progression. PMID:19759878

  6. TRPA1-like channels enhance glycinergic transmission in medullary dorsal horn neurons.

    PubMed

    Cho, Jin-Hwa; Jeong, Moon-Young; Choi, In-Sun; Lee, Heon-Jin; Jang, Il-Sung

    2012-08-01

    The effect of icilin, a potent agonist of transient receptor potential ankyrin 1 (TRPA1) and TRPM8, on glycinergic transmission was examined in mechanically isolated rat medullary dorsal horn neurons by use of the conventional whole-cell patch-clamp technique. Icilin increased the frequency of glycinergic spontaneous miniature inhibitory post-synaptic currents (mIPSCs) in a dose-dependent manner. Either allyl isothiocyanate(AITC) or cinnamaldehyde, other TRPA1 agonists, also increased mIPSC frequency, but the extent of facilitation induced by AITC or cinnamaldehyde was less than that induced by icilin. However, menthol, a TRPM8 agonist, had no facilitatory effect on glycinergic mIPSCs. The icilin-induced increase in mIPSC frequency was significantly inhibited by either HC030031, a selective TRPA1 antagonist, or ruthenium red, a non-selective transient receptor potential channel blocker. Icilin failed to increase glycinergic mIPSC frequency in the absence of extracellular Ca(2+), suggesting that the icilin-induced increase in mIPSC frequency is mediated by the Ca(2+) influx from the extracellular space. In contrast, icilin still increased mIPSC frequency either in the Na(+) -free external solution or in the presence of Cd(2+), a general voltage-dependent Ca(2+) channel blocker. The present results suggest that icilin acts on pre-synaptic TRPA1-like ion channels, which are permeable to Ca(2+), to enhance glycinergic transmission onto medullary dorsal horn neurons. The TRPA1-like channel-mediated enhancement of glycinergic transmission in medullary dorsal horn neurons would contribute to the regulation of pain information from the peripheral tissues.

  7. Differential Activation of Medullary Vagal Nuclei Caused by Stimulation of Different Esophageal Mechanoreceptors

    PubMed Central

    Lang, Ivan M.; Medda, Bidyut K.; Shaker, Reza

    2010-01-01

    Esophageal mechanorecptors, i.e. muscular slowly adapting tension receptors and mucosal rapidly adapting touch receptors, mediate different sets of reflexes. The aim of this study was to determine the medullary vagal nuclei involved in the reflex responses to activation of these receptors. Thirty-three cats were anesthetized with alpha-chloralose and the esophagus was stimulated by slow balloon or rapid air distension. The physiological effects of the stimuli (N=4) were identified by recording responses from the pharyngeal, laryngeal, and hyoid muscles, esophagus, and the lower esophageal sphincter (LES). The effects on the medullary vagal nuclei of the stimuli: slow distension (N=10), rapid distension (N=9), and in control animals (N=10) were identified using the immunohistochemical analysis of c-fos. The experimental groups were stimulated 3 times per minute for 3 hours. After the experiment, the brains were removed and processed for c-fos immunoreactivity or thioinin. We found that slow balloon distension activated the esophago-UES contractile reflex and esophago LES relaxation response, and rapid air injection activated the belch and its component reflexes. Slow balloon distension activated the NTSce, NTSdl, NTSvl, DMNc, DMNr and NAr; and rapid air injection primarily activated AP, NTScd, NTSim, NTSis, NTSdm, NTSvl, NAc and NAr. We concluded that different sets of medullary vagal nuclei mediate different reflexes of the esophagus activated from different sets of mechanoreceptors. The NTScd is the primary NTS subnucleus mediating reflexes from the mucosal rapidly adapting touch receptors, and the NTSce is the primary NTS subnucleus mediating reflexes from the muscular slowly adapting tension receptors. The AP may be involved in mediation of belching. PMID:20971087

  8. Cholinergic modulation of primary afferent glutamatergic transmission in rat medullary dorsal horn neurons.

    PubMed

    Jeong, Seok-Gwon; Choi, In-Sun; Cho, Jin-Hwa; Jang, Il-Sung

    2013-12-01

    Although muscarinic acetylcholine (mACh) receptors are expressed in trigeminal ganglia, it is still unknown whether mACh receptors modulate glutamatergic transmission from primary afferents onto medullary dorsal horn neurons. In this study, we have addressed the cholinergic modulation of primary afferent glutamatergic transmission using a conventional whole cell patch clamp technique. Glutamatergic excitatory postsynaptic currents (EPSCs) were evoked from primary afferents by electrical stimulation of trigeminal tract and monosynaptic EPSCs were recorded from medullary dorsal horn neurons of rat horizontal brain stem slices. Muscarine and ACh reversibly and concentration-dependently decreased the amplitude of glutamatergic EPSCs and increased the paired-pulse ratio. In addition, muscarine reduced the frequency of miniature EPSCs without affecting the current amplitude, suggesting that muscarine acts presynaptically to decrease the probability of glutamate release onto medullary dorsal horn neurons. The muscarine-induced decrease of glutamatergic EPSCs was significantly occluded by methoctramine or AF-DX116, M2 receptor antagonists, but not pirenzepine, J104129 and MT-3, selective M1, M3 and M4 receptor antagonists. The muscarine-induced decrease of glutamatergic EPSCs was highly dependent on the extracellular Ca2+ concentration. Physostigmine and clinically available acetylcholinesterase inhibitors, such as rivastigmine and donepezil, significantly shifted the concentration-inhibition relationship of ACh for glutamatergic EPSCs. These results suggest that muscarine acts on presynaptic M2 receptors to inhibit glutamatergic transmission by reducing the Ca2+ influx into primary afferent terminals, and that M2 receptor agonists and acetylcholinesterase inhibitors could be, at least, potential targets to reduce nociceptive transmission from orofacial tissues.

  9. Neonatal transient renal failure with renal medullary hyperechogenicity: clinical and laboratory features.

    PubMed

    Makhoul, Imad R; Soudack, Michalle; Smolkin, Tatiana; Sujov, Polo; Epelman, Monica; Eisenstein, Israel; Magen, Daniela; Zelikovic, Israel

    2005-07-01

    Sonographic findings of renal medullary hyperechogenicity have been observed in the neonate in association with severe perinatal renal injury, kidney malformations or nephrocalcinosis, and, rarely, in newborn infants with transient renal failure. The aim of the study was to describe the entity of neonatal transient renal failure with renal medullary hyperechogenicity (NTRFMH). We studied nine term neonates, born between August 1999 and February 2004 in our institution (0.1% of the live born infants), who developed transient renal dysfunction after birth, and in whom renal sonograms showed bilateral medullary hyperechogenicity. Seven of the infants (78%) had anuria until 30-45 hours of age, and two (22%) had oliguria. Peak serum creatinine levels ranged between 0.61 and 1.62 mg/dL (mean: 1.09+/-0.27 mg/dL) at 2-3 days of life. Additional findings included proteinuria in nine infants (100%), uric acid crystalluria in seven (78%), hyperuricemia in four (44%), and hypertension in one (11%). Hyperuricosuria was demonstrated in one out of the seven patients in whom this parameter was determined. Urinary excretion rates of calcium, phosphorus and oxalic acid were normal, as were urinary levels of amino acids and organic acids. Full clinical recovery accompanied by normalization of all laboratory parameters was observed in all infants by 4-6 days of life. Subsequent follow-up showed normal renal function, no urinary abnormalities, and normal renal sonograms in all infants. Our summary of the nine infants with NTRFMH reported on here and a review of 19 cases of this condition reported in the literature reveal a not-so-rare entity of unclear etiology, but excellent prognosis. Physicians caring for neonates should be aware of this benign and transient condition.

  10. Medullary circuitry regulating rapid eye movement (REM) sleep and motor atonia

    PubMed Central

    Vetrivelan, Ramalingam; Fuller, Patrick M; Tong, Qingchun; Lu, Jun

    2009-01-01

    Considerable data support a role for glycinergic ventromedial medulla neurons in the mediation of the postsynaptic inhibition of spinal motoneurons necessary for the motor atonia of rapid-eye movement (REM) sleep in cats. These data are however difficult to reconcile with the fact that large lesions of the rostral ventral medulla do not result in loss of REM atonia in rats. In the present study, we sought to clarify which medullary networks in rodents are responsible for REM motor atonia by retrogradely tracing inputs to the spinal ventral horn from the medulla, ablating these medullary sources to determine their effects on REM atonia and using transgenic mice to identify the neurotransmitter(s) involved. Our results reveal a restricted region within the ventromedial medulla, termed here the ‘supraolivary medulla’ (SOM), which contains glutamatergic neurons that project to the spinal ventral horn. Cell-body specific lesions of the SOM resulted in an intermittent loss of muscle atonia, taking the form of exaggerated phasic muscle twitches, during REM sleep. A concomitant reduction in REM sleep time was observed in the SOM-lesioned animals. We next used mice with lox-P modified alleles of either the glutamate or GABA/glycine vesicular transporters to selectively eliminate glutamate or GABA/glycine neurotransmission from SOM neurons. Loss of SOM glutamate release, but not SOM GABA/glycine release, resulted in exaggerated muscle twitches during REM sleep that were similar to those observed following SOM lesions in rats. These findings, taken together, demonstrate that SOM glutamatergic neurons comprise key elements of the medullary circuitry mediating REM atonia. PMID:19625526

  11. Are there one million nerve fibres in the human medullary pyramid?

    PubMed

    Wada, A; Goto, J; Goto, N; Kawamura, N; Matsumoto, K

    2001-03-01

    It has been the accepted opinion that there are one million nerve fibres in the human medullary pyramid. This seemed to be confirmed in several old reports. But we cannot agree with this opinion. We made nitrocellulose-embedded sections from three normal male brains, and stained them by our modification of Masson-Goldner method. With this method, myelinated axons appeared in blue, whereas the glial processes were coloured in red, which allowed easy discrimination between the two. After morphometric evaluation of the pyramidal axons under the microscope, it appeared without the slightest doubt, that the number of axons does not exceed one-tenth of one million.

  12. Recognition of a CD4+ mouse medullary thymocyte subpopulation by Amaranthus leucocarpus lectin.

    PubMed Central

    Lascurain, R; Chávez, R; Gorocica, P; Pérez, A; Montaño, L F; Zenteno, E

    1994-01-01

    We have used the Gal beta(1-->3)GalNAc-specific Amaranthus leucocarpus lectin to isolate a thymus cell subpopulation which is different from that sorted with Arachis hypogaea lectin. The cells recognized by A. leucocarpus lectin were predominantly CD4+, whereas a minor proportion of CD8+ cells (approximately 11%) were also identified. The A. leucocarpus-positive cells were located in the thymus medulla and the cortico-medullary junction. The cortex was negative for A. leucocarpus cells. Images Figure 1 Figure 2 Figure 3 PMID:7835965

  13. Renal Medullary Carcinoma with an Aggressive Clinical Course: A Case Report and Review of the Literature

    PubMed Central

    Kalavar, Madhumati R.; Ali, Sami; Safarpour, Damoun; Kunnakkat, Saroj Davi

    2017-01-01

    Renal medullary carcinoma (RMC) is a rare, yet aggressive malignancy of the kidney that is found predominantly in young patients with African descent and sickle cell hemoglobinopathies and most specifically sickle cell trait. Due to its aggressive nature, most cases have metastasis or local invasion at the time of diagnosis. Prognosis is extremely poor with survival less than 1 year after diagnosis. Here we present a case of metastatic RMC in a 29-year-old African female. Despite chemotherapy with cisplatin, gemcitabine, and paclitaxel, and initial shrinkage of the tumor, the patient died 5 months after diagnosis. PMID:28203160

  14. Horner's Syndrome Incidental to Medullary Thyroid Carcinoma Excision: Case Report and Brief Literature Review

    PubMed Central

    Mastronikolis, Nicholas S.; Spiliopoulou, Sofia P.; Zolota, Vassiliki; Papadas, Theodoros A.

    2016-01-01

    Horner's syndrome is characterized by a combination of ipsilateral miosis, blepharoptosis, enophthalmos, facial anhidrosis, and iris heterochromia in existence of congenital lesions. The syndrome results from a disruption of the ipsilateral sympathetic innervation of the eye and ocular adnexa at different levels. Though rare, thyroid and neck surgery could be considered as possible causes of this clinical entity. We present a case of Horner's syndrome in a patient after total thyroidectomy and neck dissection for medullary thyroid cancer with neck nodal disease and attempt a brief review of the relevant literature. PMID:27200201

  15. Multiple endocrine neoplasia similar to human subtype 2A in a dog: Medullary thyroid carcinoma, bilateral pheochromocytoma and parathyroid adenoma

    PubMed Central

    Arias, E.A. Soler; Castillo, V.A.; Trigo, R.H.; Caneda Aristarain, M.E.

    2016-01-01

    Human multiple endocrine neoplasia subtype 2A (MEN 2A) is characterized by medullary thyroid carcinoma, pheochromocytoma and parathyroid hyperplasia or adenoma in the same individual. In this report, a case of a female Rottweiler with medullary thyroid carcinoma, bilateral pheochromocytoma and parathyroid adenoma was described. Clinical manifestations of muscle weakness, polydipsia, polyuria, diarrhea and weight loss were observed. Two adrenal neoplasms were identified incidentally by ultrasonography, and tumor in the left thyroid lobe was identified by palpation. Primary hyperparathyroidism was diagnosed by biochemical testing. Histopathology report was consistent with diagnosis of bilateral pheochromocytoma and parathyroid adenoma. Immunohistochemical staining was positive for calcitonin and synaptophysin, and negative for thyroglobulin, which confirmed medullary thyroid carcinoma. This case in a dog is presenting neoplastic characteristics similar to human MEN 2A and emphasizing the importance of using immunohistochemistry for confirmation. PMID:27822452

  16. Intramedullary neurenteric cyst of the conus medullaris without associated spinal malformation: a case report and review of the literature.

    PubMed

    Sadeghi-Hariri, Behrouz; Khalatbari, Mahmoud Reza; Hassani, Hajar; Taheri, Behrouz; Abbassioun, Kazem

    2012-01-01

    Spinal neurenteric (NE) cysts are rare congenital anomalies that may occur either alone or in the context of a complex malformative disorder. They are usually intradural-extramedullary lesions. Intramedullary NE cysts not associated with other congenital anomalies are very rare and only a few cases have been reported in the conus medullaris region. Intramedullary neurenteric cysts not associated with other spinal anomalies are very rare especially in the conus medullaris region. MRI is useful to define the cyst and the osseous anomalies associated with this lesion. The goal of treatment of an intramedullary neurenteric cyst is total excision at the first operation, if possible. Life-long follow-up with annual MRI is recommended due to the risk of cyst recurrence. We report an intramedullary NE cyst of the conus medullaris without associated malformation and the relevant literature is briefly reviewed.

  17. Modulation of NMDA receptor expression in the rat spinal cord by peripheral nerve injury and adrenal medullary grafting.

    PubMed

    Hama, A T; Unnerstall, J R; Siegan, J B; Sagen, J

    1995-07-31

    Excessive activation of N-methyl-D-aspartate (NMDA) receptors in the spinal cord consequent to peripheral injury has been implicated in the initiation of neuropathologic events leading to a state of chronic hyperexcitability and persistence of exaggerated sensory processing. In other CNS disease or injury states, NMDA-mediated neurotoxic damage is associated with a loss of NMDA receptors, and outcome may be improved by agents reducing NMDA activation. Previous findings in our laboratory have demonstrated that the transplantation of adrenal medullary tissue into the spinal subarachnoid space can alleviate sensory abnormalities and reduce the induction of a putative nitric oxide synthase consequent to peripheral nerve injury. In order to determine changes in NMDA receptor expression in the spinal cord following peripheral nerve injury and adrenal medullary grafting, NMDA receptor binding using a high-affinity competitive NMDA receptor antagonist, CGP-39653, and NMDAR1 subunit distribution using immunocytochemistry were investigated. Two weeks following peripheral nerve injury by loose ligation of the right sciatic nerve, either adrenal medullary or striated muscle (control) tissue pieces were implanted in the spinal subarachnoid space. Binding studies revealed a marked reduction in [3H]CGP-39653 binding at L4-L5 levels ipsilateral to peripheral nerve injury in control transplanted animals. In contrast, NMDA binding was normalized in adrenal medullary grafted animals. In addition, NMDAR1 immunoreactivity was reduced in both the dorsal horn neuropil and motor neurons of the ventral horn in animals with peripheral nerve injury, while levels in adrenal medullary grafted animals appeared similar to intact controls. These results suggest that adrenal medullary transplants reduce abnormal sensory processing resulting from peripheral injury by intervening in the spinal NMDA-excitotoxicity cascade.

  18. Measuring coal thickness

    NASA Technical Reports Server (NTRS)

    Barker, C.; Blaine, J.; Geller, G.; Robinson, R.; Summers, D.; Tyler, J.

    1980-01-01

    Laboratory tested concept, for measuring thickness of overhead coal using noncontacting sensor system coupled to controller and high pressure water jet, allows mining machines to remove virtually all coal from mine roofs without danger of cutting into overlying rock.

  19. Origami of thick panels

    NASA Astrophysics Data System (ADS)

    Chen, Yan; Peng, Rui; You, Zhong

    2015-07-01

    Origami patterns, including the rigid origami patterns in which flat inflexible sheets are joined by creases, are primarily created for zero-thickness sheets. In order to apply them to fold structures such as roofs, solar panels, and space mirrors, for which thickness cannot be disregarded, various methods have been suggested. However, they generally involve adding materials to or offsetting panels away from the idealized sheet without altering the kinematic model used to simulate folding. We develop a comprehensive kinematic synthesis for rigid origami of thick panels that differs from the existing kinematic model but is capable of reproducing motions identical to that of zero-thickness origami. The approach, proven to be effective for typical origami, can be readily applied to fold real engineering structures.

  20. Improvements of CO2 and O2 Transmission Modeling for ASCENDS Mission Applications

    NASA Technical Reports Server (NTRS)

    Pliutau, Denis; Prasad, Narashimha S.

    2011-01-01

    Simulations using the HITRAN database and other data have been carried out to select the optimum laser wavelengths for the measurements of CO2 and O2 concentrations with the application to the ASCENDS mission. The accuracy set forth for the ASCENDS mission requires accurate line-by-line calculations involving the use of non-Voigt line shapes. To aid in achieving this goal, improved CO2 and O2 transmission calculation methods are being developed. In particular, line-by-line transmission modeling of CO2 was improved by implementing non-Voigt spectral lineshapes. Ongoing work involves extending this approach to the O2 molecule 1.26-1.27micron spectral band.

  1. [A case of ascending colon carcinoma metastasized to an inguinal hernia sac].

    PubMed

    Miyake, Yasuhiro; Kato, Takeshi; Katayama, Kinzo; Doi, Takashi; Oshima, Kazuteru; Handa, Rio; Hoshi, Minako; Makari, Yoichi; Oshima, Satoshi; Iijima, Shohei; Kurokawa, Eiji; Kikkawa, Nobuteru

    2007-11-01

    While inguinal hernia is one of the most common diseases, metastatic cancer of an inguinal hernia sac is rare. We report a case of ascending colon cancer metastasized to an inguinal hernia sac. A 60-year-old man, who was undergone a right hemicolectomy for an ascending colon cancer, was pointed out a palpable inguinal mass at one year and eight months after the operation. He was diagnosed as inguinal hernia, and herniorrhaphy was performed. In the operation, a tumor of the inguinal hernia sac, which invaded to spermatic cord, could be found and was removed with right testis. Bassini's method was performed after the resection of the inguinal tumor. Histological examination revealed that the tumor was metastasis of colon carcinoma. Examination of the entire body showed no other metastasis. As for the advanced colon cancer, we need to mention the possibility of metastatic saccular tumor.

  2. Phase transformations in an ascending adiabatic mixed-phase cloud volume

    NASA Astrophysics Data System (ADS)

    Pinsky, M.; Khain, A.; Korolev, A.

    2015-04-01

    Regimes of liquid-ice coexistence that may form in an adiabatic parcel ascending at constant velocity at freezing temperatures are investigated. Four zones with different microphysical structures succeeding one another along the vertical direction have been established. On the basis of a novel balance equation, analytical expressions are derived to determine the conditions specific for each of these zones. In particular, the necessary and sufficient conditions for formation of liquid water phase within an ascending parcel containing only ice particles are determined. The results are compared to findings reported in earlier studies. The role of the Wegener-Bergeron-Findeisen mechanism in the phase transformation is analyzed. The dependence of the phase relaxation time on height in the four zones is investigated on the basis of a novel analytical expression. The results obtained in the study can be instrumental for analysis and interpretation of observed mixed-phase clouds.

  3. Spectrum analysis of turbulence in the canine ascending aorta measured with a hot-film anemometer.

    PubMed

    Yamaguchi, T; Kikkawa, S; Tanishita, K; Sugawara, M

    1988-01-01

    We measured turbulence velocity in the canine ascending aorta using a hot-film anemometer. Blood flow velocity was measured at various points across the ascending aorta approximately 1.5-2 times the diameter downstream from the aortic valve. The turbulence spectrum was calculated and its characteristics were examined in connection with the mean Reynolds number and/or measuring positions. In the higher wave number range the values of the turbulence spectra were higher at larger mean Reynolds number. In the higher wave number range, the values of the turbulence spectra were higher at points closer to the centerline of the aorta, when the mean Reynolds number was relatively large. The patterns of the turbulence spectra at various points outside the boundary layer on the aortic wall were similar.

  4. Cervical response among ascending ventrolateral funiculus pathways of the neonatal rat.

    PubMed

    Reed, William R; Magnuson, David S K

    2013-01-23

    Propriospinal pathways, consisting of axons from interneurons that project to other spinal segments, have been implicated as likely candidates to mediate interlimb coordination in developing and adult mammals during quadrupedal locomotion. The superficial thoracic ventrolateral funiculus (VLF) contains both ascending and descending axons, and when stimulated can induce alternating rhythmic locomotor-like activity in the lumbar ventral roots of the isolated neonatal rat spinal cord. The goal of this work was to characterize the synaptic inputs onto cervical neurons from ascending axons in the VLF. Sprague-Dawley rats (P4-P7) were deeply anesthesized with halothane and their spinal cords were isolated, removed, and maintained in vitro. Intracellular recordings were made from 68 cervical (C5-C7) neurons having 71 latency classifications in response to thoracic VLF stimulation. Antidromic (n=35), monosynaptic (n=2), di-or tri-synaptic (n=18) and long-latency polysynaptic (n=16) responses were recorded. Recordings from reduced preparations (mid-sagittal section at C5-C7) suggest that much of the delay in the long-latency polysynaptic responses require a bilaterally intact cervical spinal cord. Fifty-three percent (17/32) of the VLF responsive cervical interneurons tested also exhibited long latency excitatory responses to lumbar dorsal root stimulation suggesting that many of the cervical VLF responsive interneurons receive indirect input from lumbar primary afferents. We hypothesize that the VLF contains a population of ascending axons originating from lumbar propriospinal interneurons that can influence cervical inter- and motoneurons. These ascending VLF axons may participate in interlimb coordination by providing moment-by-moment feedback to the cervical enlargement of lumbar central pattern generator and/or hindlimb proprioceptive activity.

  5. Medical and Surgical Management of a Descending Aorta Penetrating Atherosclerotic Ulcer and Associated Ascending Intramural Hematoma

    PubMed Central

    Henn, Matthew C.; Lawrance, Christopher P.; Braverman, Alan C.; Sanchez, Luis; Lawton, Jennifer S.

    2014-01-01

    A 69-year-old man presented with chest pain and a computed tomography scan demonstrated an acute penetrating atherosclerotic ulcer (PAU) of the proximal descending aorta with an associated intramural hematoma (IMH) extending retrograde to the aortic root and distally to the renal arteries. He successfully underwent endovascular repair of the PAU and medical management of the associated ascending intramural hematoma with complete resolution at 6 months. PMID:26798718

  6. Epigenetic regulation of TGF-β1 signalling in dilative aortopathy of the thoracic ascending aorta.

    PubMed

    Forte, Amalia; Galderisi, Umberto; Cipollaro, Marilena; De Feo, Marisa; Della Corte, Alessandro

    2016-08-01

    The term 'epigenetics' refers to heritable, reversible DNA or histone modifications that affect gene expression without modifying the DNA sequence. Epigenetic modulation of gene expression also includes the RNA interference mechanism. Epigenetic regulation of gene expression is fundamental during development and throughout life, also playing a central role in disease progression. The transforming growth factor β1 (TGF-β1) and its downstream effectors are key players in tissue repair and fibrosis, extracellular matrix remodelling, inflammation, cell proliferation and migration. TGF-β1 can also induce cell switch in epithelial-to-mesenchymal transition, leading to myofibroblast transdifferentiation. Cellular pathways triggered by TGF-β1 in thoracic ascending aorta dilatation have relevant roles to play in remodelling of the vascular wall by virtue of their association with monogenic syndromes that implicate an aortic aneurysm, including Loeys-Dietz and Marfan's syndromes. Several studies and reviews have focused on the progression of aneurysms in the abdominal aorta, but research efforts are now increasingly being focused on pathogenic mechanisms of thoracic ascending aorta dilatation. The present review summarizes the most recent findings concerning the epigenetic regulation of effectors of TGF-β1 pathways, triggered by sporadic dilative aortopathy of the thoracic ascending aorta in the presence of a tricuspid or bicuspid aortic valve, a congenital malformation occurring in 0.5-2% of the general population. A more in-depth comprehension of the epigenetic alterations associated with TGF-β1 canonical and non-canonical pathways in dilatation of the ascending aorta could be helpful to clarify its pathogenesis, identify early potential biomarkers of disease, and, possibly, develop preventive and therapeutic strategies.

  7. Computed tomography in the diagnosis of latrogenic false aneurysms of the ascending aorta

    SciTech Connect

    Moore, E.H.; Farmer, D.W.; Geller, S.C.; Golden, J.A.; Gamsu, G.

    1984-06-01

    False aneurysm (contained rupture) of the ascending aorta is a rare complication of aortic valve replacement. The authors have dealt with two such cases that resulted from breakdown of the aortotomy suture line. In both cases, CT scan with intravenous injection of contrast material demonstrated opacification of the lumen of the false aneurysm sac; in neither case was communication with the aorta demonstrable on aortography.

  8. [Ascending aorta-supraceliac++ aorta bypass. Correction of a case of atypical coarctation in the adult].

    PubMed

    Vaquero, F; Zorita, A; Samos, R F; Vázquez, J G; Ortega, J M; Morán, C F

    1993-01-01

    A case of atypic coarctation at the aortic arch in an adult patient is described. Coarctation was surgically treated by a retrosternal bypass from the ascendant aorta to the supra-celiac aorta. After a short prelude the clinical case is summarized. Furthermore, the etiopathogenic features of the disease, the different diagnostic methods and the multiple surgical procedures are discussed. Finally, we briefly review the literature.

  9. Response Allocation in Concurrent Chains when Terminal-Link Delays Follow an Ascending and Descending Series

    ERIC Educational Resources Information Center

    Christensen, Darren R.; Grace, Randolph C.

    2009-01-01

    Eight pigeons were trained in a concurrent-chains procedure in which the terminal-link immediacy ratio followed an ascending or descending series. Across sessions, one terminal-link delay changed from 2 s to 32 s to 2 s or from 32 s to 2 s to 32 s, while the other was always 8 s. For all pigeons, response allocation tracked changes in delay and…

  10. Modelling atherosclerosis by proteomics: Molecular changes in the ascending aortas of cholesterol-fed rabbits.

    PubMed

    Xu, Jingshu; Jüllig, Mia; Middleditch, Martin J; Cooper, Garth J S

    2015-09-01

    The cholesterol-fed rabbit is commonly used as a model to study the vascular effects of hypercholesterolemia and resulting atherosclerotic lesions. Here we undertook a proteomic case-control investigation of ascending aortas from male New Zealand White rabbits after 10 weeks on a high-cholesterol (2% w/w) diet (HCD, n = 5) or control diet (n = 5), in order to determine the changes in response to the HCD. Histology confirmed intimal thickening in the HCD group consistent with atherosclerosis, and LC-MS/MS analysis of individually-obtained ascending aortic extracts labelled with isobaric (iTRAQ) tags enabled the identification and quantitation of 453 unique proteins above the 1% false discovery rate threshold. Of 67 proteins showing significant differences in relative abundance (p < 0.05), 62 were elevated and five decreased in ascending aortas from HCD-fed rabbits compared to controls. Six proteins were selected for validation using Multiple Reaction Monitoring, which confirmed the iTRAQ results. Many of the observed protein changes are consistent with known molecular perturbations in the ascending aorta that occur in response to hypercholesterolemia, e.g. elevation of tissue levels of apolipoproteins, extracellular matrix adhesion proteins, glycolytic enzymes, heat shock proteins and proteins involved in immune defense. We also made a number of novel observations, including a 15-fold elevation of glycoprotein (trans-membrane) nmb-like (Gpnmb) in response to HCD. Gpnmb has previously been linked to angiogenesis but not to atherosclerosis. This and additional novel observations merit further investigation as these perturbations may play important and as yet undiscovered roles in the pathogenesis of atherosclerosis in rabbits as well as humans.

  11. Adatom Ascending at Step Edges and Faceting on fcc Metal (110) Surfaces

    SciTech Connect

    Zhu, W.; de Mongeot, F. B.; Valbusa, U.; Wang, E. G.; Zhang, Zhenyu

    2004-01-01

    Using first-principles total-energy calculations, we show that an adatom can easily climb up at monatomic-layer-high steps on several representative fcc metal (110) surfaces via a place exchange mechanism. Inclusion of such novel adatom ascending processes in kinetic Monte Carlo simulations of Al(110) homoepitaxy as a prototypical model system can lead to the existence of an intriguing faceting instability, whose dynamical evolution and kinetic nature are explored in comparison with experimental observations.

  12. A Regional CO2 Observing System Simulation Experiment Using ASCENDS Observations and WRF-STILT Footprints

    NASA Technical Reports Server (NTRS)

    Wang, James S.; Kawa, S. Randolph; Eluszkiewicz, Janusz; Collatz, G. J.; Mountain, Marikate; Henderson, John; Nehrkorn, Thomas; Aschbrenner, Ryan; Zaccheo, T. Scott

    2012-01-01

    Knowledge of the spatiotemporal variations in emissions and uptake of CO2 is hampered by sparse measurements. The recent advent of satellite measurements of CO2 concentrations is increasing the density of measurements, and the future mission ASCENDS (Active Sensing of CO2 Emissions over Nights, Days and Seasons) will provide even greater coverage and precision. Lagrangian atmospheric transport models run backward in time can quantify surface influences ("footprints") of diverse measurement platforms and are particularly well suited for inverse estimation of regional surface CO2 fluxes at high resolution based on satellite observations. We utilize the STILT Lagrangian particle dispersion model, driven by WRF meteorological fields at 40-km resolution, in a Bayesian synthesis inversion approach to quantify the ability of ASCENDS column CO2 observations to constrain fluxes at high resolution. This study focuses on land-based biospheric fluxes, whose uncertainties are especially large, in a domain encompassing North America. We present results based on realistic input fields for 2007. Pseudo-observation random errors are estimated from backscatter and optical depth measured by the CALIPSO satellite. We estimate a priori flux uncertainties based on output from the CASA-GFED (v.3) biosphere model and make simple assumptions about spatial and temporal error correlations. WRF-STILT footprints are convolved with candidate vertical weighting functions for ASCENDS. We find that at a horizontal flux resolution of 1 degree x 1 degree, ASCENDS observations are potentially able to reduce average weekly flux uncertainties by 0-8% in July, and 0-0.5% in January (assuming an error of 0.5 ppm at the Railroad Valley reference site). Aggregated to coarser resolutions, e.g. 5 degrees x 5 degrees, the uncertainty reductions are larger and more similar to those estimated in previous satellite data observing system simulation experiments.

  13. Ascending in utero herpes simplex virus infection in an initially healthy-appearing premature infant.

    PubMed

    Edwards, Morven S; Popek, Edwina J; Wise, Brittany; Hatzenbuehler, Lindsay; Arunachalam, Athis R; Hair, Amy B

    2015-01-01

    The usual route of acquisition for intrauterine herpes simplex virus (HSV) infection is transplacental. We evaluated a premature infant with in utero acquisition of HSV resulting from ascending infection. Histopathologic evidence of chronic chorioamnionitis and positive staining with immunohistochemistry for HSV in the placenta and umbilical cord established the diagnosis. The clinical presentation was also of interest in that the infant was initially healthy appearing.

  14. Medullary lateral line units of rudd, Scardinius erythrophthalmus, are sensitive to Kármán vortex streets.

    PubMed

    Klein, Adrian; Winkelnkemper, Jan; Dylda, Evelyn; Bleckmann, Horst

    2015-07-01

    We investigated the responses of medullary lateral line units of the rudd, Scardinius erythrophthalmus, to bulk water flow (7 cm s(-1)) and to water flow that contained vortices shed by an upstream half cylinder (diameter 1, 2, and 3 cm). Thirty-five percent of the medullary units either increased or decreased their discharge rate with the increasing cylinder diameter. In some units, the spike patterns revealed the vortex shedding frequency, i.e., in these units the amplitude of spike train frequency spectra was similar or identical to the vortex shedding frequency.

  15. Pneumorrhachis Resulting in Transient Paresis after PICC Line Insertion into the Ascending Lumbar Vein

    PubMed Central

    Sieg, Emily P; Choudhary, Arabinda; Iantosca, Mark

    2016-01-01

    Obtaining intravascular access in the neonatal intensive care unit (NICU) is not only critical but also technically challenging. Malposition of the catheter tip is a known and well-documented complication. Specifically, peripherally inserted central venous catheter (PICC) line insertion into the ascending lumbar vein can lead to neurological dysfunction and, in some cases, even death. We present the first reported case of pneumorrhachis (PR) following PICC line insertion into the ascending lumbar vein. Our patient presented with lower extremity weakness and imaging confirmed the presence of air within the spinal canal. After conservative treatment, the strength deficit resolved and subsequent imaging revealed resolution of the air within the spinal canal. Insertion of central venous catheters into the ascending lumbar vein is a well-documented complication that can lead to neurologic injury and even death. This should be considered in the evaluation of any neonate presenting with an abnormal neurological examination or unexplained change in exam after line insertion. PMID:27904815

  16. Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS) Mission Studies

    NASA Astrophysics Data System (ADS)

    Jones, C.; Hyon, J.; Anderson, K.; Rodriguez-Alvaraz, O.; DiJoseph, M.; Dempsey, J.; Andrew, G.

    2012-12-01

    ASCENDS is one of the National Research Council's Decadal Survey Tier II missions. It will provide improved ability to predict/model long-term changes in the climate cycle based on the understanding of the natural processes driving the variability of natural carbon sources and sink, and the transport of carbon through the atmosphere. NASA's GSFC, LaRC and JPL are conducting mission studies to determine spacecraft and launch vehicle accommodations. These mission studies will determine the feasibility of flying the ASCENDS instrument on a commercially available spacecraft bus and launch vehicle. Conceptual instrument parameters include a mass of 500 kilograms, power of 1100 Watts and volume of 2.5 meters by 2 meters by 2 meters. Preliminary results have shown that the Falcon 9 and the Atlas V are compatible launch vehicles. Multiple commercially available spacecraft buses on the Rapid Spacecraft Development Office's (RSDO) catalogue also appear to be compatible with the instruments parameters. In this paper, we present the details of the ASCENDS instrument and mission constraints and the results of our mission studies.

  17. Voclosporin food effect and single oral ascending dose pharmacokinetic and pharmacodynamic studies in healthy human subjects.

    PubMed

    Mayo, Patrick R; Huizinga, Robert B; Ling, Spencer Y; Freitag, Derrick G; Aspeslet, Launa J; Foster, Robert T

    2013-08-01

    Voclosporin (VCS) is a novel calcineurin (CN) inhibitor intended for prevention of organ graft rejection and treatment of lupus nephritis. These studies evaluated the single ascending dose pharmacokinetics (PK) and pharmacodynamics (PD, CN activity) of VCS and the effect of food. VCS was administered orally in single doses of 0.25 through 4.5 mg/kg in 62 subjects in the single ascending dose study and as a single oral 1.5 mg/kg dose to 18 subjects after fasting, consumption of a low-fat and high-fat meal. Non-compartmental PK, PD, and PKPD correlation were evaluated. Following single oral doses, systemic exposure increased in a linear manner and demonstrated 1:1 dose-proportional, first-order linear PK above 1.5 mg/kg. VCS inhibited CN activity in a dose-related fashion with maximal inhibition peaking at 3.0 mg/kg. PKPD correlation indicated an EC50 of 78.3 ± 6.8 ng/mL. Administration of VCS with a low-fat and high-fat meal decreased C(max) by 29% and 53%, respectively, and AUC(inf) by 15% and 25%, respectively. Following ascending single doses of VCS, exposure increased in a linear fashion. A food effect on exposure was demonstrated, with a more pronounced effect following a high-fat meal. VCS concentrations were also found to correlate with CN activity.

  18. FSP1+ fibroblast subpopulation is essential for the maintenance and regeneration of medullary thymic epithelial cells

    PubMed Central

    Sun, Lina; Sun, Chenming; Liang, Zhanfeng; Li, Hongran; Chen, Lin; Luo, Haiying; Zhang, Hongmei; Ding, Pengbo; Sun, Xiaoning; Qin, Zhihai; Zhao, Yong

    2015-01-01

    Thymic epithelial cells (TECs) form a 3-dimentional network supporting thymocyte development and maturation. Besides epithelium and thymocytes, heterogeneous fibroblasts are essential components in maintaining thymic microenvironments. However, thymic fibroblast characteristics, development and function remain to be determined. We herein found that thymic non-hematopoietic CD45-FSP1+ cells represent a unique Fibroblast specific protein 1 (FSP1)—fibroblast-derived cell subset. Deletion of these cells in FSP1-TK transgenic mice caused thymus atrophy due to the loss of TECs, especially mature medullary TECs (MHCIIhigh, CD80+ and Aire+). In a cyclophosphamide-induced thymus injury and regeneration model, lack of non-hematopoietic CD45-FSP1+ fibroblast subpopulation significantly delayed thymus regeneration. In fact, thymic FSP1+ fibroblasts released more IL-6, FGF7 and FSP1 in the culture medium than their FSP1- counterparts. Further experiments showed that the FSP1 protein could directly enhance the proliferation and maturation of TECs in the in vitro culture systems. FSP1 knockout mice had significantly smaller thymus size and less TECs than their control. Collectively, our studies reveal that thymic CD45-FSP1+ cells are a subpopulation of fibroblasts, which is crucial for the maintenance and regeneration of TECs especially medullary TECs through providing IL-6, FGF7 and FSP1. PMID:26445893

  19. Potassium transport by medullary collecting tubule of rabbit: Effects of variation in K intake

    SciTech Connect

    Wingo, C.S. Veterans Administration Medical Center, Gainesville, FL )

    1987-12-01

    These studies examine the effect of dietary K content on the rate efflux coefficient (K{sub k}) assessed both isotopically ({sup 42}K) and by net K flux in segments dissected from the inner stripe of the outer medullary collecting tubule (MCT). Female New Zealand White rabbits were given either a K-replete diet (KCl diet) or one of two K-restricted diets with similar K content. After 7 days, renal K excretion varied with K intake. To determine whether alterations in K{sub k} of MCT could contribute to these changes in urinary K excretion, the MCT from the three groups of rabbits was perfused in vitro and volume reabsorption and K{sub k} were measured. Net K flux in the presence of a 15 mM lumen-to-bath K gradient confirmed a significantly greater K reabsorptive flux and net rate coefficient in either K-restricted group than the K-replete control group. A model used to assess the relative contribution of cortical secretory flux and medullary absorptive flux shows that at physiological flow rates for the MCT such alterations in the apparent K permeability of the MCT could have dramatic effects on the reabsorption of K from the lumen and thereby on K excretion. These observations demonstrate that K movement from lumen to interstitium is influenced by dietary K intake and that the MCT participates in K homeostasis.

  20. Renal medullary carcinoma: sonographic, computed tomography, magnetic resonance and angiographic findings.

    PubMed

    Khan, A; Thomas, N; Costello, B; Jobling, L; deKretser, D; Broadfield, E; O'Shea, S

    2000-07-01

    Renal medullary carcinoma is a recently described, highly aggressive tumour, occurring predominantly in young patients of African descent with sickle cell trait (SCT). All have been metastatic at surgery. Surgery, radiotherapy and chemotherapy do not appear to alter the course of the disease. The survival time is very short. Presentation is usually with haematuria, abdominal pain and weight loss. Forty-nine patients have been reported from the USA, of these 47 were African/Americans. The reports have mostly appeared in pathology journals. On review of the imaging findings reported in the radiological journals, it becomes apparent that it is possible for a radiologist to suggest a specific diagnosis in the appropriate demographic and clinical setting. Here the first British patient of Afro-Caribbean decent in whom a pre-operative diagnosis was suggested on the imaging findings of a centrally located renal pelvic tumour, encasing the pelvis on a background of SCT in a 28-year-old is described. It is expected that a high index of suspicion in the appropriate clinical setting may lead to earlier diagnosis, treatment and survival of patients. The patient is alive and reasonably well 9 months after surgery. The full range of imaging findings in renal medullary carcinoma are described.

  1. Targeting mTOR in RET mutant medullary and differentiated thyroid cancer cells

    PubMed Central

    Gild, Matti L; Landa, Iñigo; Ryder, Mabel; Ghossein, Ronald A; Knauf, Jeffrey A; Fagin, James A

    2015-01-01

    Inhibitors of RET, a tyrosine kinase receptor encoded by a gene that is frequently mutated in medullary thyroid cancer, have emerged as promising novel therapies for the disease. Rapalogs and other mammalian target of rapamycin (mTOR) inhibitors are effective agents in patients with gastroenteropancreatic neuroendocrine tumors, which share lineage properties with medullary thyroid carcinomas. The objective of this study was to investigate the contribution of mTOR activity to RET-induced signaling and cell growth and to establish whether growth suppression is enhanced by co-targeting RET and mTOR kinase activities. Treatment of the RET mutant cell lines TT, TPC-1, and MZ-CRC-1 with AST487, a RET kinase inhibitor, suppressed growth and showed profound and sustained inhibition of mTOR signaling, which was recapitulated by siRNA-mediated RET knockdown. Inhibition of mTOR with INK128, a dual mTORC1 and mTORC2 kinase inhibitor, also resulted in marked growth suppression to levels similar to those seen with RET blockade. Moreover, combined treatment with AST487 and INK128 at low concentrations suppressed growth and induced apoptosis. These data establish mTOR as a key mediator of RET-mediated cell growth in thyroid cancer cells and provide a rationale for combinatorial treatments in thyroid cancers with oncogenic RET mutations. PMID:23828865

  2. Ectopic ACTH Production Leading to Diagnosis of Underlying Medullary Thyroid Carcinoma

    PubMed Central

    Matheny, Leslee N.; Wilson, Jessica R.; Baum, Howard B. A.

    2016-01-01

    Medullary thyroid carcinoma (MTC) has been described as a source of ectopic ACTH secretion in patients with Cushing’s syndrome. This is an infrequent association, occurring in less than 1% of MTC cases. Among these, it is even more unusual for an initial diagnosis of hypercortisolism to lead to the discovery of underlying MTC. Here we present a case of a patient with weakness, diarrhea, and hypokalemia who was found first to have Cushing’s syndrome and later diagnosed with metastatic MTC. The patient was treated initially with oral agents to control his hypercortisolism, then with an etomidate infusion after experiencing intestinal perforation. He also received vandetanib therapy targeting his underlying malignancy, as this has been shown to reverse clinical signs of Cushing’s syndrome in patients with MTC and subsequent ectopic ACTH secretion. Bilateral adrenalectomy was ultimately required. Medullary thyroid carcinoma should be considered in patients presenting with Cushing’s syndrome due to ectopic ACTH secretion, and a multimodality treatment approach is often required. PMID:27141514

  3. Immunohistochemical and ultrastructural analysis of medullary carcinoma of the thyroid in relation to hormone production.

    PubMed Central

    Kameya, T.; Shimosato, Y.; Adachi, I.; Abe, K.; Kasai, N.; Kimura, K.; Baba, K.

    1977-01-01

    Eighteen cases of medullary carcinoma of the thyroid were analyzed immunohistochemically for calcitonin- and ACTH-containing cells, and tumor cells in 8 cases were examined by an electron microscope and analyzed by manual and computer procedures with particular attention paid to the size and quality of secretory granules. Calcitonin- and ACTH-containing cells were found singly or in clusters in 14 and 11 tumors, respectively. In 4 cases, calcitonin-positive cell clusters and an increase in number of singly scattered C cells were seen apart from the main tumor, suggesting a multicentric nature of certain medullary carcinomas. Some ACTH-containing cells were apparently also positive for calcitonin. In a case of familial Sipple disease, follicular lining cells were replaced in areas with ACTH-containing cells. Three to five frequency distribution curves of the size of secretory granules were obtained in all of 6 cases analyzed, and at least two different types of granule matrix were identified. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 PMID:202164

  4. Neuropsychological effects of brain autograft of adrenal medullary tissue for the treatment of Parkinson's disease.

    PubMed

    Ostrosky-Solís, F; Quintanar, L; Madrazo, I; Drucker-Colín, R; Franco-Bourland, R; Leon-Meza, V

    1988-09-01

    We describe the pre- and postoperative neuropsychological profiles of seven patients who received an autograft of adrenal medullary tissue to the caudate nucleus for the treatment of Parkinson's Disease (PD). The preoperative neuropsychological evaluations revealed specific cognitive deficits of varying degree. The patients showed frontal lobe-type deficits with alterations in behavioral programming leading to difficulties in the organization of motor sequences and alternating programs. They also showed memory disorders and visuospatial and visuoperceptual deficiences such as a loss of figure-ground perspective and fragmentation. Postoperative evaluations, carried out 3 months after neurosurgery, revealed a significant amelioration of the frontal lobe-type symptoms and visuospatial deficits, as well as an improvement in memory tasks that require an active organization of the response. Immediate and delayed memory difficulties remained unchanged. These observations were compared to neuropsychological data obtained from neurologically intact subjects and from unoperated PD patients. The improvements of the operated PD patients resulted in performance levels close to normal values and clearly distinguishable from those of unoperated PD patients, and were unrelated to improved mood, increased alertness, or sustained attention. Autotransplantation of adrenal medullary tissue to the caudate nucleus of PD patients showing a decreased effective response to L-dopa therapy can partially restore motor functions and frontal-type cognitive symptoms.

  5. Adrenal medullary transplantation to the caudate nucleus in Parkinson's disease. Initial clinical results in 18 patients.

    PubMed

    Allen, G S; Burns, R S; Tulipan, N B; Parker, R A

    1989-05-01

    Results from a pilot study of adrenal medullary autotransplantation for Parkinson's disease are presented. Eighteen patients were studied; 12 were followed up for 1 year, and 6 were followed up for 6 months. Four of 12 patients showed distinct improvement in the signs and symptoms of their disease, as assessed using the Columbia Rating Scale, at 1 year; none showed distinct deterioration. The 6 patients who were followed up for only 6 months were an average of 20 years older and generally more severely affected. None distinctly improved. Morbidity was considered to be minor and transient among the first 12 patients, while 4 of the last 6 patients experienced alteration in mental status lasting as long as several months. This problem has led us to conclude that older patients with preexisting cognitive impairment should not be included in future studies until the benefits are more clearly established. However, we believe that the distinct and persistent improvement seen in some of the younger patients warrants the initiation of a well-designed, randomized, and controlled trial of adrenal medullary autotransplantation for the purpose of confirming these results and assessing the effect of the procedure on the natural progression of Parkinson's disease.

  6. Upregulation of norepinephrine transporter function by prolonged exposure to nicotine in cultured bovine adrenal medullary cells.

    PubMed

    Itoh, Hideaki; Toyohira, Yumiko; Ueno, Susumu; Saeki, Satoru; Zhang, Han; Furuno, Yumi; Takahashi, Kojiro; Tsutsui, Masato; Hachisuka, Kenji; Yanagihara, Nobuyuki

    2010-09-01

    Nicotine acts on nicotinic acetylcholine receptors in the adrenal medulla and brain, thereby stimulating the release of monoamines such as norepinephrine (NE). In the present study, we examined the effects of prolonged exposure to nicotine on NE transporter (NET) activity in cultured bovine adrenal medullary cells. Treatment of adrenal medullary cells with nicotine increased [(3)H]NE uptake in both a time- (1-5 days) and concentration-dependent (0.1-10 muM) manner. Kinetic analysis showed that nicotine induced an increase in the V (max) of [(3)H]NE uptake with little change in K (m). This increase in NET activity was blocked by cycloheximide, an inhibitor of ribosomal protein synthesis, but not by actinomycin D, a DNA-dependent RNA polymerase inhibitor. [(3)H]NE uptake induced by nicotine was strongly inhibited by hexamethonium and mecamylamine but not by alpha-bungarotoxin, and was abolished by elimination of Ca(2+) from the culture medium. KN-93, an inhibitor of Ca(2+)/calmodulin-dependent protein kinase II, attenuated not only nicotine-induced [(3)H]NE uptake but also (45)Ca(2+) influx in the cells. The present findings suggest that long-term exposure to nicotine increases NET activity through a Ca(2+)-dependent post-transcriptional process in the adrenal medulla.

  7. Medullary metastasis of a malignant peripheral nerve sheath tumor: A case report

    PubMed Central

    Hagi, Tomohito; Nakamura, Tomoki; Yokoji, Ayumu; Matsumine, Akihiko; Sudo, Akihiro

    2016-01-01

    The present study reports a case of medullary metastasis without lung metastasis that occurred as a result of a malignant peripheral nerve sheath tumor (MPNST). An 81-year-old woman presented with a MPNST in the left brachial plexus, arising from the cervical nerve root. The patient underwent carbon ion radiotherapy; however, tumor recurrence was identified in the left shoulder. Subsequently, the patient underwent wide excision. Three weeks subsequent to surgery, imbalance and dysarthria developed suddenly. Dysphagia emerged and left upper limb pain disappeared on the day after symptom development. Magnetic resonance imaging (MRI) revealed that this was due to metastasis to the medulla. Five days subsequent to the onset of dysarthria, the patient succumbed due to respiratory failure. To the best of our knowledge, no previous cases of medullary metastasis arising from a MPNST in the absence of lung metastasis have been reported. MRI is a useful examination tool for the identification of brain metastases; however, the high cost of MRI as a routine examination must be considered due to the rarity of brain metastases. Therefore, methods to detect brain metastasis warrant further investigation. PMID:27588138

  8. Medullary respiratory neural activity during hypoxia in NREM and REM sleep in the cat.

    PubMed

    Lovering, Andrew T; Fraigne, Jimmy J; Dunin-Barkowski, Witali L; Vidruk, Edward H; Orem, John M

    2006-02-01

    Intact unanesthetized cats hyperventilate in response to hypocapnic hypoxia in both wakefulness and sleep. This hyperventilation is caused by increases in diaphragmatic activity during inspiration and expiration. In this study, we recorded 120 medullary respiratory neurons during sleep in hypoxia. Our goal was to understand how these neurons change their activity to increase breathing efforts and frequency in response to hypoxia. We found that the response of medullary respiratory neurons to hypoxia was variable. While the activity of a small majority of inspiratory (58%) and expiratory (56%) neurons was increased in response to hypoxia, the activity of a small majority of preinspiratory (57%) neurons was decreased. Cells that were more active in hypoxia had discharge rates that averaged 183% (inspiratory decrementing), 154% (inspiratory augmenting), 155% (inspiratory), 230% (expiratory decrementing), 191% (expiratory augmenting), and 136% (expiratory) of the rates in normoxia. The response to hypoxia was similar in non-rapid-eye-movement (NREM) and REM sleep. Additionally, changes in the profile of activity were observed in all cell types examined. These changes included advanced, prolonged, and abbreviated patterns of activity in response to hypoxia; for example, some inspiratory neurons prolonged their discharge into expiration during the postinspiratory period in hypoxia but not in normoxia. Although changes in activity of the inspiratory neurons could account for the increased breathing efforts and activity of the diaphragm observed during hypoxia, the mechanisms responsible for the change in respiratory rate were not revealed by our data.

  9. Effects of oxalate on IMCD cells: a line of mouse inner medullary collecting duct cells.

    PubMed

    Maroni, Paul D; Koul, Sweaty; Meacham, Randall B; Chandhoke, Paramjit S; Koul, Hari K

    2004-12-01

    Oxalate, a metabolic end product and a major constituent of the majority of renal stones, has been shown to be toxic to renal epithelial cells of cortical origin. However, it is unknown whether inner medullary collecting duct (IMCD) cells that are physiologically exposed to higher concentrations of oxalate also behave in a similar manner. In the present study, we examined the effects of oxalate on IMCD cells. IMCD cells from the mouse were maintained in DMEM/F12 media supplemented with fetal bovine serum and antibiotics. Exposure of IMCD cells to oxalate produced time- and concentration-dependent changes in the light microscopic appearance of the cells. Long-term exposure to oxalate resulted in alterations in cell viability, with net cell loss after exposure to concentrations of 2 mM or greater. The production of free radicals was directly related to the exposure time and the concentration of oxalate. Crystal formation occurred in less than 1 h and cells in proximity to crystals would lose membrane integrity. Compared with IMCD cells, LLC-PK1 cells as well as HK-2 cells showed significant toxicity starting at lower oxalate concentrations (0.4 mM or greater). These results provide the first direct demonstration of toxic effects of oxalate in IMCD cells, a line of renal epithelial cells of the inner medullary collecting duct, and suggest that the cells lining the collecting duct are relatively resistant to oxalate toxicity.

  10. A machine learning approach to investigate the relationship between shape features and numerically predicted risk of ascending aortic aneurysm.

    PubMed

    Liang, Liang; Liu, Minliang; Martin, Caitlin; Elefteriades, John A; Sun, Wei

    2017-04-06

    Geometric features of the aorta are linked to patient risk of rupture in the clinical decision to electively repair an ascending aortic aneurysm (AsAA). Previous approaches have focused on relationship between intuitive geometric features (e.g., diameter and curvature) and wall stress. This work investigates the feasibility of a machine learning approach to establish the linkages between shape features and FEA-predicted AsAA rupture risk, and it may serve as a faster surrogate for FEA associated with long simulation time and numerical convergence issues. This method consists of four main steps: (1) constructing a statistical shape model (SSM) from clinical 3D CT images of AsAA patients; (2) generating a dataset of representative aneurysm shapes and obtaining FEA-predicted risk scores defined as systolic pressure divided by rupture pressure (rupture is determined by a threshold criterion); (3) establishing relationship between shape features and risk by using classifiers and regressors; and (4) evaluating such relationship in cross-validation. The results show that SSM parameters can be used as strong shape features to make predictions of risk scores consistent with FEA, which lead to an average risk classification accuracy of 95.58% by using support vector machine and an average regression error of 0.0332 by using support vector regression, while intuitive geometric features have relatively weak performance. Compared to FEA, this machine learning approach is magnitudes faster. In our future studies, material properties and inhomogeneous thickness will be incorporated into the models and learning algorithms, which may lead to a practical system for clinical applications.

  11. Asymptomatic anisakiasis of the colon incidentally diagnosed and treated during colonoscopy by retroflexion in the ascending colon

    PubMed Central

    Tsukui, Mamiko; Morimoto, Naoki; Kurata, Hidekazu; Sunada, Fumiko

    2016-01-01

    A 74-year-old man with diabetes underwent colonoscopy as routine screening for colon cancer. An Anisakis larva was found incidentally during colonoscopy using the retroflexion technique in the ascending colon, and was removed using a forceps. Asymptomatic colonic anisakiasis is very rare, and few reports have described diagnosis and treatment of anisakiasis during colonoscopy by the retroflexion technique in the ascending colon. We have reported this rare case along with a literature review. PMID:27928460

  12. Psychophysical demonstration of bidirectional pain modulation (sensitization and desensitization) by ascending or descending progressions of thermal stimulus intensity.

    PubMed

    Vierck, Charles J; Riley, Joseph L; Wong, Fong; King, Christopher D; Mauderli, Andre P

    2010-08-06

    A psychophysical method of response-dependent stimulation presented ascending and descending series of thermal stimulus intensities that maintained an average rating (setpoint) of mild pain (20 on a scale of 0-100) or moderate pain (35). Subjects were presented with alternating series of thermal stimuli that increased until ratings reached or exceeded the setpoint, then decreased until ratings equaled or were less than the setpoint, then increased, etc. Plots of pain intensity ratings differed substantially for series of ascending and descending stimulus intensities. After an ascending series, pain ratings during a descending series were higher than predicted, and after a descending series, pain ratings during an ascending series were lower than predicted. Thus, the nervous system detects and discriminates between ascending and descending trends in stimulus intensity and alters the magnitude of pain sensations in the direction of the trend of increasing or decreasing stimulus intensity. Ascending (sensitizing) trend effects may increase the magnitude of pathological pain in the absence of treatment, and descending (desensitizing) trend effects likely would enhance the efficacy of procedures that reduce pain sensitivity.

  13. Oxygen-dependent expression of hypoxia-inducible factor-1alpha in renal medullary cells of rats.

    PubMed

    Zou, A P; Yang, Z Z; Li, P L; Cowley AW, J R

    2001-08-28

    Hypoxia-inducible factor-1alpha (HIF-1alpha) is a transcription factor that regulates the oxygen-dependent expression of a number of genes. This transcription factor may contribute to the abundant expression of many genes in renal medullary cells that function normally under hypoxic conditions. The present study was designed to determine the characteristics of HIF-1alpha cDNA cloned from the rat kidney and the expression profile of HIF-1alpha in different kidney regions and to explore the mechanism activating or regulating HIF-1alpha expression in renal medullary cells. A 3,718-bp HIF-1alpha cDNA from the rat kidney was first cloned and sequenced using RT-PCR and TA cloning technique. It was found that 823 amino acids deduced from this renal HIF-1alpha cDNA had 99%, 96%, and 90% identity with rat, mouse, or human HIF-1alpha deposited in GenBank, respectively. The 3'-untranslated region of HIF-1alpha mRNA from the rat kidney contained seven AUUUA instability elements, five of which were found to be conserved among rat, mouse, and human HIF-1alpha. Northern blot analyses demonstrated a corticomedullary gradient of HIF-1alpha mRNA expression in the kidney, with the greatest abundance in the renal inner medulla. Western blot analyses also detected a higher HIF-1alpha protein level in the nuclear extracts from the renal medulla than the renal cortex. A classic loop diuretic, furosemide (10 mg/kg ip), markedly increased renal medullary Po(2) levels from 22.5 to 52.2 mmHg, which was accompanied by a significant reduction of HIF-1alpha transcripts in renal medullary tissue. In in vitro experiments, low Po(2), but not elevated osmolarity, was found to significantly increase HIF-1alpha mRNA in renal medullary interstitial cells and inner medullary collecting duct cells. These results indicate that HIF-1alpha is more abundantly expressed in the renal medulla compared with the renal cortex. Increased abundance of HIF-1alpha mRNA in the renal medulla may represent an adaptive

  14. Thick Film Interference.

    ERIC Educational Resources Information Center

    Trefil, James

    1983-01-01

    Discusses why interference effects cannot be seen with a thick film, starting with a review of the origin of interference patterns in thin films. Considers properties of materials in films, properties of the light source, and the nature of light. (JN)

  15. Does the position of conus medullaris change with increased thoracolumbar kyphosis in ankylosing spondylitis patients?

    PubMed Central

    Qu, Zhe; Qian, Bang-ping; Qiu, Yong; Zhang, Yun-peng; Hu, Jun; Zhu, Ze-zhang

    2017-01-01

    Abstract To date, only a few reports described the potential factors influencing the position of conus medullaris. One previous study revealed no significant change of conus locations in patients with idiopathic scoliosis; however, the effect of ankylosing spondylitis (AS)-related thoracolumbar kyphosis on conus position remains unexplored. Therefore, we aimed to investigate the variation of conus medullaris terminations in patients with thoracolumbar kyphosis secondary to AS when compared with normal subjects, and evaluated the relationship between conus positions and the magnitude of kyphosis. In this study, MR images of 96 AS patients with thoracolumbar kyphosis, including 86 males and 10 females with an average of 34.6 years (range, 17–65 years), and 100 age-matched normal controls were reviewed to determine the conus terminations in relation to spinal levels. Sagittal parameters of the AS group measured on radiograph included: global kyphosis (GK), thoracic kyphosis (TK), lumbar lordosis (LL), and thoracolumbar junction (TLJ). Finally, conus tips located at the mean level of the lower 3rd of L1 in both groups, there was no significant difference of the conus distributions between AS and control group (P = 0.49). In addition, conus medullaris displayed similar positions in AS patients among various apical region groups (P = 0.88), and no significant difference was found when AS population was stratified into GK ranges of 30° (P = 0.173). Also, no remarkable correlation of the conus positions with GK (r = −0.15, P = 0.15), TK (r = −0.10, P = 0.34), LL (r = −0.10, P = 0.32), and TLJ (r = −0.06, P = 0.54) was identified. This study showed the conus terminations displayed a wide range of distributions in AS patients with thoracolumbar kyphosis, which was similar to normal subjects. Moreover, the conus located at a relatively fixed position and would not be affected by the change of kyphosis magnitude, which is

  16. The mormyrid brainstem--II. The medullary electromotor relay nucleus: an ultrastructural horseradish peroxidase study.

    PubMed

    Elekes, K; Ravaille, M; Bell, C C; Libouban, S; Szabo, T

    1985-06-01

    The medullary relay nucleus of the mormyrid weakly electric fish Gnathonemus petersii is a stage in the command pathway for the electric organ discharge. It receives input from the presumed command or pacemaker nucleus and projects to the electromotoneurons in the spinal cord. Its fine structure and synaptology were investigated by electron microscopy. The origin of the terminals contacting the cell membrane of the neurons of this nucleus was determined by horseradish peroxidase (HRP) injections into different brain structures, namely into the bulbar command- and mesencephalic command-associated nuclei. Twenty-five to thirty large cells of about 45 micron in diameter constitute the medullary electromotor relay. Each cell has a kidney-shaped, lobulated nucleus, a large myelinated axon with a short initial segment and several long, richly arborizing primary dendrites. Many, if not all, cells are interconnected with large somatosomatic or dendrosomatic, dendrodendritic and dendroaxonic gap junctions. These junctions often occur in serial or triadic arrangements. The relay cells receive large club endings as well as small boutons. The club endings are found mainly on the soma and primary dendrites and are morphologically mixed synapses. The boutons are characterized by synapses which are only chemical and are distributed all over the cell membrane, but with a definitely higher frequency on secondary dendrites and more distal parts of dendritic processes. Horseradish peroxidase injections into the mesencephalic command-associated nucleus reveal a large number of labelled boutons on the secondary dendrites of the relay cells. Injections into the bulbar command-associated nucleus label the same type of boutons as mesencephalic injections, but also label club endings on relay cell soma and primary dendrites. The results support the conclusion made on the basis of previous light microscopical observations that boutons originate from the bulbar command-associated nucleus

  17. Nephronophthisis-medullary cystic kidney disease: from bedside to bench and back again.

    PubMed

    Scolari, Francesco; Ghiggeri, Gian Marco

    2003-01-01

    Medullary cystic kidney disease (MCKD) belongs with nephronophthisis (NPH) to the NPH-MCKD complex, a group of inherited tubulointerstitial nephritis which share some morphological and clinical features. Juvenile NPH, the most frequent variant of the complex, is a recessive disease with onset in childhood leading to end stage renal disease (ESRD) within the 2nd decade of life. The most frequent extrarenal involvement is tapeto-retinal degeneration. MCKD is a less frequent disease with dominant inheritance; it is recognized later in life, leading to ESRD at the age of 50 years, and may be associated with hyperuricemia and gout. In an early phase, both NPH and MCKD are pauci-symptomatic, major signs being confined to polyuria. Later in the course, clinical findings are related to the progressive renal insufficiency, such as anemia, uremic symptoms and, in NPH, growth retardation. On renal ultrasound, the kidneys present an increased medullary echogenicity with diminished cortico-medullary differentiation. Renal cysts may be present, usually at corticomedullary boundary. Due to the clinico-pathological identity, the two diseases were considered to be a single disorder, and the compromise appellation of NPH-MCKD complex was suggested. This unifying conception was subsequently refuted following the identification of MCKD dominant families. The recent advances of the molecular genetics changed the traditional classification of NPH-MCKD complex. The majority of cases of juvenile NPH are due to deletion of the NPHP1 gene on chromosome 2q13. Genes for infantile and adolescent NPH have been localized to chromosome 9q22-q31 and 3q22, respectively. A new locus, NPHP4, has been recently mapped on chromosome 1p36. Two genes predisposing to dominant MCKD, MCKD1 and MCKD2, have been localized to chromosome 1q21 and to chromosome 16p12. Moreover, a gene for familial juvenile hyperuricemic nephropathy (FJHN), a phenotype very similar to MCKD, was mapped to 16p12 in a region

  18. Medullary serotonergic network deficiency in the sudden infant death syndrome: review of a 15-year study of a single dataset.

    PubMed

    Kinney, H C; Filiano, J J; White, W F

    2001-03-01

    The sudden infant death syndrome (SIDS) is the leading cause of postneonatal infant mortality in the United States today, despite a dramatic 38% decrease in incidence due to a national risk reduction campaign advocating the supine sleep position. Our research in SIDS brainstems, beginning in 1985 and involving a single, large dataset, has become increasingly focused upon a specific neurotransmitter (serotonin) and specific territories (ventral medulla and regions of the medullary reticular formation that contain secrotonergic neurons). Based on this research, we propose that SIDS, or a subset of SIDS, is due to a developmental abnormality in a medullary network composed of (at least in part) rhombic lip-derived, serotonergic neurons, including in the caudal raphé and arcuate nucleus (putative human homologue of the cat respiratory chemosensitive fields); and this abnormality results in a failure of protective responses to life-threatening stressors (e.g. asphyxia, hypoxia, hypercapnia) during sleep as the infant passes through a critical period in homeostatic control. We call this the medullary serotonergic network deficiency hypothesis. We review the triple-risk model for SIDS, the development of the dataset using tissue autoradiography for analyzing neurotransmitter receptor binding; age-dependent baseline neurochemical findings in the human brainstem during early life; the evidence for serotonergic, rhombic lip, and ventral medullary deficits in at least some SIDS victim; possible mechanisms of sudden infant death related to these deficits; and potential causes of the deficits in the medullary serotonergic network in SIDS victims. We conclude with a summary of future directions in SIDS brainstem research.

  19. Skeletal dosimetry for external exposures to photons based on {mu}CT images of spongiosa: Consideration of voxel resolution, cluster size, and medullary bone surfaces

    SciTech Connect

    Kramer, R.; Khoury, H. J.; Vieira, J. W.; Brown, K. A. Robson

    2009-11-15

    Skeletal dosimetry based on {mu}CT images of trabecular bone has recently been introduced to calculate the red bone marrow (RBM) and the bone surface cell (BSC) equivalent doses in human phantoms for external exposure to photons. In order to use the {mu}CT images for skeletal dosimetry, spongiosa voxels in the skeletons were replaced at run time by so-called micromatrices, which have exactly the size of a spongiosa voxel and contain segmented trabecular bone and marrow microvoxels. A cluster (=parallelepiped) of 2x2x2=8 micromatrices was used systematically and periodically throughout the spongiosa volume during the radiation transport calculation. Systematic means that when a particle leaves a spongiosa voxel to enter into a neighboring spongiosa voxel, then the next micromatrix in the cluster will be used. Periodical means that if the particle travels through more than two spongiosa voxels in a row, then the cluster will be repeated. Based on the bone samples available at the time, clusters of up to 3x3x3=27 micromatrices were studied. While for a given trabecular bone volume fraction the whole-body RBM equivalent dose showed converging results for cluster sizes between 8 and 27 micromatrices, this was not the case for the BSC equivalent dose. The BSC equivalent dose seemed to be very sensitive to the number, form, and thickness of the trabeculae. In addition, the cluster size and/or the microvoxel resolution were considered to be possible causes for the differences observed. In order to resolve this problem, this study used a bone sample large enough to extract clusters containing up to 8x8x8=512 micromatrices and which was scanned with two different voxel resolutions. Taking into account a recent proposal, this investigation also calculated the BSC equivalent dose on medullary surfaces of cortical bone in the arm and leg bones. The results showed (1) that different voxel resolutions have no effect on the RBM equivalent dose but do influence the BSC equivalent

  20. Advancing IM-CW Lidar Modulation Techniques for ASCENDS CO2 Column Measurements from Space

    NASA Astrophysics Data System (ADS)

    Campbell, J. F.; Lin, B.; Nehrir, A. R.; Harrison, F. W.; Chen, S.; Obland, M. D.

    2013-12-01

    Global atmospheric carbon dioxide (CO2) measurements through the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) decadal survey recommended space mission are critical for improving our understanding of CO2 sources and sinks. IM-CW (Intensity Modulated Continuous Wave) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS science requirements. In previous laboratory and flight experiments we have successfully used linear swept frequency modulation to discriminate surface lidar returns from intermediate aerosol and cloud contamination. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate clouds, which is a requirement for the inversion of the CO2 column mixing ratio from the instrument optical depth measurements, has been demonstrated with the linear swept frequency modulation technique. We are concurrently investigating advanced techniques to help improve the auto-correlation properties of the transmitted waveform implemented through physical hardware to make cloud rejection more robust in special restricted scenarios. Several different modulation techniques are compared including orthogonal linear swept, orthogonal non-linear swept, time shifted PN, sine wave modulated PN, and sine wave pulsed PN. Different PN code techniques are presented that are appropriate for different types of lidar hardware, including our current ASCENDS IM-CW concept space hardware. These techniques have excellent auto-correlation properties without sidelobes while possessing a finite bandwidth (by way of a new cyclic digital filter), which will reduce bias error in the presence of multiple scatterers. Our analyses show that the studied modulation techniques can increase the accuracy of CO2 column measurements from space.

  1. Ascending projections of the mammillary region in the pigeon: emphasis on telencephalic connections.

    PubMed

    Berk, M L; Hawkin, R F

    1985-09-15

    The ascending projections of the mammillary region of the hypothalamus and adjacent posterolateral hypothalamus were investigated by autoradiographic and horseradish peroxidase histochemical techniques. Analysis of the anterograde data revealed that the main contingent of mammillary fibers ascends in the medial forebrain bundle (MFB) in the lateral hypothalamic area. These fibers distribute to a number of telencephalic regions via three pathways. (1) Fibers course dorsomedially into the medial and lateral parts of the septum and continue into the hippocampus with a dense terminal field in the parahippocampal area. (2) Laterally coursing fibers project to area corticoidea dorsolateralis, area temporo-parieto-occipitalis, cortex piriformis, and the posterior part of archistriatum. (3) The fibers remaining in the MFB ascend into the "ventral paleostriatum," olfactory tubercle, and into the lateral and ventral borders of the rostral portion of lobus parolfactorius (LPO). Numerous fibers leave the LPO region and course dorsally into the deep layer of the Wulst, hyperstriatum dorsale (HD). Many fibers continue dorsolaterally through the HD and enter an unnamed region of the dorsolateral telencephalon (lateral to the vallecula) at the level of the olfactory bulb. Retrograde transport experiments revealed that the perikarya of origin-of-fiber projections to the parahippocampal area and to the rostral, dorsolateral telencephalon reside not only in nucleus mammillaris lateralis but also in posterolateral hypothalamic cells rostral and dorsal to this nucleus. The projection of these hypothalamic cells to the hippocampal formation and many other telencephalic regions in birds suggests that these cells are similar to the mammalian supramammillary nucleus and posterolateral hypothalamus rather than the mammillary nuclei.

  2. The lateral reticular nucleus; integration of descending and ascending systems regulating voluntary forelimb movements.

    PubMed

    Alstermark, Bror; Ekerot, Carl-Fredrik

    2015-01-01

    Cerebellar control of movements is dependent on mossy fiber input conveying information about sensory and premotor activity in the spinal cord. While much is known about spino-cerebellar systems, which provide the cerebellum with detailed sensory information, much less is known about systems conveying motor information. Individual motoneurones do not have projections to spino-cerebellar neurons. Instead, the fastest route is from last order spinal interneurons. In order to identify the networks that convey ascending premotor information from last order interneurons, we have focused on the lateral reticular nucleus (LRN), which provides the major mossy fiber input to cerebellum from spinal interneuronal systems. Three spinal ascending systems to the LRN have been investigated: the C3-C4 propriospinal neurones (PNs), the ipsilateral forelimb tract (iFT) and the bilateral ventral flexor reflex tract (bVFRT). Voluntary forelimb movements involve reaching and grasping together with necessary postural adjustments and each of these three interneuronal systems likely contribute to specific aspects of forelimb motor control. It has been demonstrated that the command for reaching can be mediated via C3-C4 PNs, while the command for grasping is conveyed via segmental interneurons in the forelimb segments. Our results reveal convergence of ascending projections from all three interneuronal systems in the LRN, producing distinct combinations of excitation and inhibition. We have also identified a separate descending control of LRN neurons exerted via a subgroup of cortico-reticular neurones. The LRN projections to the deep cerebellar nuclei exert a direct excitatory effect on descending motor pathways via the reticulospinal, vestibulospinal, and other supraspinal tracts, and might play a key role in cerebellar motor control. Our results support the hypothesis that the LRN provides the cerebellum with highly integrated information, enabling cerebellar control of complex forelimb

  3. Quasi-oscillatory dynamics observed in ascending phase of the flare on March 6, 2012

    NASA Astrophysics Data System (ADS)

    Philishvili, E.; Shergelashvili, B. M.; Zaqarashvili, T. V.; Kukhianidze, V.; Ramishvili, G.; Khodachenko, M.; Poedts, S.; De Causmaecker, P.

    2017-03-01

    Context. The dynamics of the flaring loops in active region (AR) 11429 are studied. The observed dynamics consist of several evolution stages of the flaring loop system during both the ascending and descending phases of the registered M-class flare. The dynamical properties can also be classified by different types of magnetic reconnection, related plasma ejection and aperiodic flows, quasi-periodic oscillatory motions, and rapid temperature and density changes, among others. The focus of the present paper is on a specific time interval during the ascending (pre-flare) phase. Aims: The goal is to understand the quasi-periodic behavior in both space and time of the magnetic loop structures during the considered time interval. Methods: We have studied the characteristic location, motion, and periodicity properties of the flaring loops by examining space-time diagrams and intensity variation analysis along the coronal magnetic loops using AIA intensity and HMI magnetogram images (from the Solar Dynamics Observatory). Results: We detected bright plasma blobs along the coronal loop during the ascending phase of the solar flare, the intensity variations of which clearly show quasi-periodic behavior. We also determined the periods of these oscillations. Conclusions: Two different interpretations are presented for the observed dynamics. Firstly, the oscillations are interpreted as the manifestation of non-fundamental harmonics of longitudinal standing acoustic oscillations driven by the thermodynamically non-equilibrium background (with time variable density and temperature). The second possible interpretation we provide is that the observed bright blobs could be a signature of a strongly twisted coronal loop that is kink unstable.

  4. Peripherally-Derived BDNF Promotes Regeneration of Ascending Sensory Neurons after Spinal Cord Injury

    PubMed Central

    Zhang, Feng-He; Zhong, Jin-Hua; Zhou, Xin-Fu

    2008-01-01

    Background The blood brain barrier (BBB) and truncated trkB receptor on astrocytes prevent the penetration of brain derived neurotrophic factor (BDNF) applied into the peripheral (PNS) and central nervous system (CNS) thus restrict its application in the treatment of nervous diseases. As BDNF is anterogradely transported by axons, we propose that peripherally derived and/or applied BDNF may act on the regeneration of central axons of ascending sensory neurons. Methodology/Principal Findings The present study aimed to test the hypothesis by using conditioning lesion of the sciatic nerve as a model to increase the expression of endogenous BDNF in sensory neurons and by injecting exogenous BDNF into the peripheral nerve or tissues. Here we showed that most of regenerating sensory neurons expressed BDNF and p-CREB but not p75NTR. Conditioning-lesion induced regeneration of ascending sensory neuron and the increase in the number of p-Erk positive and GAP-43 positive neurons was blocked by the injection of the BDNF antiserum in the periphery. Enhanced neurite outgrowth of dorsal root ganglia (DRG) neurons in vitro by conditioning lesion was also inhibited by the neutralization with the BDNF antiserum. The delivery of exogenous BDNF into the sciatic nerve or the footpad significantly increased the number of regenerating DRG neurons and regenerating sensory axons in the injured spinal cord. In a contusion injury model, an injection of BDNF into the footpad promoted recovery of motor functions. Conclusions/Significance Our data suggest that endogenous BDNF in DRG and spinal cord is required for the enhanced regeneration of ascending sensory neurons after conditioning lesion of sciatic nerve and peripherally applied BDNF may have therapeutic effects on the spinal cord injury. PMID:18320028

  5. Subacute posttraumatic ascending myelopathy in a 15-year-old boy.

    PubMed

    Kovanda, Timothy J; Horn, Eric M

    2014-09-01

    Secondary injury following initial spinal cord trauma is uncommon and frequently attributed to mismanagement of an unprotected cord in the acute time period after injury. Subacute posttraumatic ascending myelopathy (SPAM) is a rare occurrence in the days to weeks following an initial spinal cord injury that is unrelated to manipulation of an unprotected cord and involves 4 or more vertebral levels above the original injury. The authors present a case of SPAM occurring in a 15-year-old boy who sustained a T3-4 fracture-dislocation resulting in a complete spinal cord injury, and they highlight the imaging findings and optimum treatment for this rare event.

  6. Rupture of an ascending aortic aneurysm as a cause of sudden death

    PubMed Central

    de Freitas, Cristielle Peres; Petrini, Carla Andrade; Araújo, Ramon Souza Goes; Lima, Luiz Guilherme Cernaglia Aureliano; Picciarelli de Lima, Patrícia

    2016-01-01

    An 84-year-old female patient was brought to the emergency department in cardiac arrest. Cardiopulmonary resuscitation maneuvers were performed but were unsuccessful. The patient had a past medical history of systemic arterial hypertension with target-organ lesions, including stroke and myocardial infarction. The autopsy was carried out, and the most striking finding was cardiac tamponade due to the rupture of an ascending aortic aneurysm at the site of a complex atheromatous plaque. Rupture is the most serious complication of a thoracic aneurysm and must be considered in the differential diagnosis of sudden death. PMID:27818955

  7. A Regional CO2 Observing System Simulation Experiment for the ASCENDS Satellite Mission

    NASA Technical Reports Server (NTRS)

    Wang, J. S.; Kawa, S. R.; Eluszkiewicz, J.; Baker, D. F.; Mountain, M.; Henderson, J.; Nehrkorn, T.; Zaccheo, T. S.

    2014-01-01

    Top-down estimates of the spatiotemporal variations in emissions and uptake of CO2 will benefit from the increasing measurement density brought by recent and future additions to the suite of in situ and remote CO2 measurement platforms. In particular, the planned NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) satellite mission will provide greater coverage in cloudy regions, at high latitudes, and at night than passive satellite systems, as well as high precision and accuracy. In a novel approach to quantifying the ability of satellite column measurements to constrain CO2 fluxes, we use a portable library of footprints (surface influence functions) generated by the WRF-STILT Lagrangian transport model in a regional Bayesian synthesis inversion. The regional Lagrangian framework is well suited to make use of ASCENDS observations to constrain fluxes at high resolution, in this case at 1 degree latitude x 1 degree longitude and weekly for North America. We consider random measurement errors only, modeled as a function of mission and instrument design specifications along with realistic atmospheric and surface conditions. We find that the ASCENDS observations could potentially reduce flux uncertainties substantially at biome and finer scales. At the 1 degree x 1 degree, weekly scale, the largest uncertainty reductions, on the order of 50 percent, occur where and when there is good coverage by observations with low measurement errors and the a priori uncertainties are large. Uncertainty reductions are smaller for a 1.57 micron candidate wavelength than for a 2.05 micron wavelength, and are smaller for the higher of the two measurement error levels that we consider (1.0 ppm vs. 0.5 ppm clear-sky error at Railroad Valley, Nevada). Uncertainty reductions at the annual, biome scale range from 40 percent to 75 percent across our four instrument design cases, and from 65 percent to 85 percent for the continent as a whole. Our uncertainty

  8. Extended replacement of a calcified ascending aorta in adulthood sporadic, diffuse type, supravalvular aortic stenosis.

    PubMed

    Borghetti, Valentino; D'Addario, Giancarlo; Bravi, Ilaria; Pardinia, Alessandro

    2011-08-01

    The diffuse variant of supravalvular aortic stenosis (SVAS) is one of the most rare congenital vascular pathological conditions of adulthood. Due to its rarity, surgical treatment of this clinical entity is still a matter of debate because of the variable degree of aortic narrowing, presence of multilevel obstruction, and age at presentation, all factors that strongly influence the disease prognosis. We report a case of an adult patient with an extremely calcified diffuse SVAS who underwent successful replacement of the ascending aorta through the interposition of a tubular prosthesis. Six months' follow-up showed complete relief of the aortic gradient and an improvement in clinical performance.

  9. Pure Motor Monoparesis in the Leg due to a Lateral Medullary Infarction.

    PubMed

    Tsuda, Hiromasa; Tanaka, Kozue; Kishida, Shuji

    2012-01-01

    A 76-year-old man with essential hypertension abruptly presented with slight left-sided leg weakness, despite normal strength in the other extremities. Left-sided Babinski's reflex was detected. There were no other neurologic abnormalities. Cranial magnetic resonance imaging demonstrated a small infarction in the lower lateral medulla oblongata on the left side. Cranial magnetic resonance angiography demonstrated an absence of flow of the left vertebral artery. He became asymptomatic within 10 days under intravenous antiplatelet agent. The corticospinal tract fibers innervating the lower extremity caudal to the pyramidal decussation might be involved. We emphasize that this is a first reported case of pure motor monoparesis in the leg due to lateral medullary infarction.

  10. Generalized AA-amyloidosis in Siberian tigers (Panthera tigris altaica) with predominant renal medullary amyloid deposition.

    PubMed

    Schulze, C; Brügmann, M; Böer, M; Brandt, H P; Pohlenz, J; Linke, R P

    1998-01-01

    Generalized amyloidosis with predominant renal medullary amyloid deposition was found in four closely related Siberian tigers (Panthera tigris altaica) suffering from end stage kidney diseases. Only minimal to mild amounts of amyloid were deposited in various organs outside the kidneys with individually variable organ involvement. The Congo red staining affinity of amyloid deposits was sensitive to potassium permanganate oxidation. The deposits were further characterized as being of the amyloid-A (AA) type by immunohistochemistry using the mouse monoclonal antibody mc4 directed against a conserved region of the human AA-protein. A combination of immunohistochemistry and Congo red staining was much more sensitive for the diagnosis of amyloid deposits than Congo red staining alone. With this combination, even minimal amyloid deposits were detected that had been missed in the first reading using Congo-red-stained slides alone. Since no common primary cause was identified, the amyloidosis was classified as idiopathic generalized AA-amyloidosis with a potential familial predisposition.

  11. The rhythmic, transverse medullary slice preparation in respiratory neurobiology: contributions and caveats.

    PubMed

    Funk, Gregory D; Greer, John J

    2013-04-01

    Our understanding of the sites and mechanisms underlying rhythmic breathing as well as the neuromodulatory control of respiratory rhythm, pattern, and respiratory motoneuron excitability during perinatal development has advanced significantly over the last 20 years. A major catalyst was the development in 1991 of the rhythmically-active medullary slice preparation, which provided precise mechanical and chemical control over the network as well as enhanced physical and optical access to key brainstem regions. Insights obtained in vitro have informed multiple mechanistic hypotheses. In vivo tests of these hypotheses, performed under conditions of reduced control and precision but more obvious physiological relevance, have clearly established the significance for respiratory neurobiology of the rhythmic slice preparation. We review the contributions of this preparation to current understanding/concepts in respiratory control, and outline the limitations of this approach in the context of studying rhythm and pattern generation, homeostatic control mechanisms and murine models of human genetic disorders that feature prominent breathing disturbances.

  12. Co-existence of L5-S1 disc herniation and conus medullaris ependymoma

    PubMed Central

    Minoğlu, Mustafa; Akkol, İsmail; Özdemir, Nail; Yıldırım, Levent

    2014-01-01

    INTRODUCTION The lumbar disc herniations are seen very common than spinal ependymomas in the neurosurgery polyclinic routine. PRESENTATION OF CASE In our case, both pathologies were seen at the most frequently located levels compatible with the literature. Aim of this case report is, to remind once more that, different pathologies can be found at the same time in a single patient; differential diagnosis must be done very carefully. DISCUSSION The routine Computed Tomography (CT) imaging for low back pain can not show the conus medullaris pathology. Spinal tumors or other similar pathologies should be kept in mind for differential diagnosis. A good medical history and a good physical examination must be completed before the final diagnosis. CONCLUSION Viewing of spinal canal with Magnetic Resonance Imaging (MRI) will be useful for the patients who we intend to do disc surgery. PMID:25460457

  13. Bilateral hamartomatous medullary lipoma within the nasal turbinate bones in a cynomolgus monkey (Macaca fascicularis)

    PubMed Central

    KATSUTA, Osamu; SHIBATA, Toru; KURIKI-YAMAMOTO, Yumi; MOCHIZUKI, Takaharu; YOSHIMI, Miwa; NOTO, Takahisa; MANO, Hidetoshi

    2016-01-01

    A 15-year-old male cynomolgus monkey (Macaca fascicularis) showed large bilateral masses in the maxillary sinus. In histopathological examination, both masses revealed benign medullary lipomas within the turbinate bones. The tumors were composed of well-developed lipocytes, trabecular bones and a few blood vessels. Although we initially diagnosed the tumor as bilateral lipomas in the nasal turbinates, it was not differentiated from lipomatous hamartoma. Findings, such as unique symmetrical proliferation, lack of border from the normal marrow and the intact surrounding tissue, indicated a lipomatous hamartoma/hamartomatous lipoma, thought to be a suitable diagnosis of the lesion. Of most interest was that such a proliferating lesion occurred in the nasal turbinate. PMID:27499062

  14. [Autosomal recessive polycystic kidney disease and complex nephronophtisis medullary cystic disease].

    PubMed

    2008-12-01

    Reseach during the past decade has led to the discovery that defects in some proteins that localize to primary cilia or the basal body are the main contributors to renal cyst development. Autosomal recessive polycystic disease and nephronophthisis- medullary cystic kidney disease are named ciliopathies. The cilium is a microtubule-based organelle that is found on most mammalian cells. Cilia-mediated hypothesis has evolved into the concept of cystogenesis, cilia bend by fluid initiate a calcium influx that prevents cyst formation. Cilia might sense stimuli in the cell enviroment and control cell polarity and mitosis. A new set of pathogenic mechanisms in renal cystic disease defined new therapeutic targets, control of intracellular calcium, inhibition of cAMP and down regulation cannonical Wnt signaling.

  15. Medullary Carcinoma of the Thyroid With Axillary Metastasis: A Case Report

    PubMed Central

    Ozdemir, Murat; Makay, Ozer; Simsir, Ilgin; Ertan, Yeşim; Icoz, Gokhan; Saygili, Füsun; Akyildiz, Mahir

    2015-01-01

    We report a case of axillary lymph node metastasis as a consequence of medullary thyroid carcinoma (MTC) in a 42-year-old man. On January 2009, the patient was referred to us for the management of right cervical lymph node enlargement. Total thyroidectomy was performed with right-sided functional neck dissection. Postoperative histopathology revealed MTC in the right lobe of the thyroid, with extrathyroidal extension and right-sided neck metastases. Multiple left cervical, mediastinal, and right axillary lymphadenopathies were detected at the third year follow-up exam. Left-sided functional neck dissection, axillary lymph node dissection, and mediastinal lymph node dissection were performed, and the pathologic outcomes revealed as the metastatic dissemination of MTC. After a disease-free term for 1 year, multiple metastatic lesions were detected in the patient. PMID:25785315

  16. Renal medullary carcinoma in a white adolescent with sickle cell trait.

    PubMed

    Daher, Paul; Bourgi, Ali; Riachy, Edward; Khoury, Antoine; Rehayem, Caline; Sader-Ghorra, Claude

    2014-07-01

    Renal medullary carcinoma (RMC) is a rare neoplasm of the kidney that has been recently described. It is almost exclusive to young patients of African descent and associated with sickle cell hemoglobinopathy, mainly sickle cell trait and hemoglobin sickle cell disease. The prognosis of RMC is very poor because of the highly aggressive behavior of this neoplasm and its resistance to conventional chemotherapy. Metastatic disease is almost universal at the time of presentation, and the malignancy is minimally responsive to a variety of regimens and/or modalities, including surgery, radiotherapy, chemotherapy, and biological immune-modulation therapy. We report the seventh case of a left RMC occurring in a white child with sickle cell trait, but with a localization of the tumor in the left kidney, considered a nonpredominant side for this type of tumor.

  17. Bone and liver images in medullary carcinoma of the thyroid gland: concise communication

    SciTech Connect

    Johnson, D.G.; Coleman, R.E.; McCook, T.A.; Dale, J.K.; Wells, S.A.

    1984-04-01

    Thirty-four patients with surgically documented medullary carcinoma of the thyroid (MCT) and elevated serum calcitonin levels had Tc-99m phosphate bone and/or Tc-99m sulfur colloid liver images for suspected metastases. Liver images demonstrated metastatic lesions in nine of 32 patients (28%). Bone images were positive for metastases in eight of 30 patients (27%). Four of these eight abnormal bone studies detected only skeletal lesions, two demonstrated only extraosseous metastases, and two showed both kinds. This study demonstrates that radionuclide bone and liver images frequently detect metastatic lesions in patients with MCT and elevated serum calcitonin levels, and that some nonskeletal metastases in patients with this tumor display an unusual affinity for bone-seeking radiotracers.

  18. Vandetanib Successfully Controls Medullary Thyroid Cancer-Related Cushing Syndrome in an Adolescent Patient

    PubMed Central

    Nella, A. A.; Fox, E.; Balis, F. M.; Quezado, M. M.; Whitcomb, P. O.; Derdak, J.; Kebebew, E.; Widemann, B. C.; Stratakis, C. A.

    2014-01-01

    Context: Ectopic Cushing syndrome due to ACTH secretion from metastatic medullary thyroid cancer (MTC) is associated with significant morbidity and mortality. Objective: The aim of the study was to describe the first case of Cushing syndrome associated with MTC in a pediatric patient and the successful reversal of Cushing syndrome with tyrosine kinase inhibitor (vandetanib) therapy. Patient and Methods: A 17-year-old Brazilian adolescent presented with metastatic MTC and associated ACTH-dependent ectopic Cushing syndrome in the context of multiple endocrine neoplasia type 2B. When the patient was treated with the tyrosine kinase inhibitor vandetanib, rapid decrease in serum cortisol and improvement of clinical symptoms were observed. Conclusion: We describe the first pediatric case of clinical and biochemical improvement of paraneoplastic MTC-related Cushing syndrome after treatment with vandetanib. Vandetanib and possibly other tyrosine kinase inhibitors may be a novel beneficial option in patients with neuroendocrine tumor-related ectopic Cushing syndrome. PMID:24617713

  19. Conus medullaris hematomyelia associated with an intradural-extramedullary cavernous angioma.

    PubMed

    Mastronardi, L; Frondizi, D; Guiducci, A; Nardi, M; Maira, G

    1999-01-01

    A unique case of a 50-year-old woman with a conus medullaris hematomyelia associated with a low thoracic intradural-extramedullary cavernous angioma localized 2 cm above is reported. The patient had a 2-month history of progressive paraparesis, hypoesthesia of legs, and bowel and bladder disturbances. The symptoms worsened acutely during the last days before admission. A thoraco-lumbar MRI showed a space-occupying lesion at T10-T11 (vertebral interspace associated with a hematomyelia localized about 2 cm below. A T10-L1 laminectomy was performed and complete removal of both lesions was obtained with microsurgical technique. A non-traumatic hematomyelia should always prompt the suspicion of a spinal AVM or, more rarely, of a cavernous angioma. The possible anatomical and clinical correlations of this unusual association are discussed.

  20. [Secondary medullary aplasia from accidental radiation:therapeutic options and evolution of the concept].

    PubMed

    de Revel, T; Fagot, T; Souleau, B; Dormont, D; Nedellec, G

    2002-07-01

    Bone marrow grafting following accidental irradiation exposure should be viewed in the perspective of a severe myeloablative syndrome linked to high medullary damage for a dose range higher than 6-8 Gy, resulting in very late or no recovery. Prognosis will depend on the presence or absence of radio-combined injuries, the toxicity of the transplant procedure, and the risk of rejection induced by insufficient percritical immunosuppression. It is in this context that new cell therapy modalities, which combine enhanced peripheral hematopoietic cell engraftment and high immunosuppressive conditioning regimen with low extrahematological toxicity, inducing early and stable mixed lymphomyeloid chimerism with minimal morbidity, can be considered. Such an approach is being evaluated in the treatment of patients with hematological malignancies at high risk of transplant-related mortality using conventional bone marrow methods.

  1. A Shunt Model of the Inner Medullary Nephron with Pre-Bend Transitions

    NASA Astrophysics Data System (ADS)

    Gonzalez, M. T.; Hegarty, A. F.; Thomas, S. R.

    2009-09-01

    Mathematical models of the renal medulla face the problem of representing water and solute transfer among tens of thousands of nephrons and blood vessels of various lengths, arranged in countercurrent fashion. Published models fall into two broad categories with respect to this issue: multi-nephron models, which explicitly represent a large number of individual nephrons, or lumped models with virtual shunts that represent the turning back of nephrons and vessels at varying depths. Shunt models have the advantage of a compact description and relatively rapid execution time but are ill-suited to faithfully represent features such as prebend transitions of epithelial permeabilities in nephrons of different lengths. A new shunt model approach that can accommodate pre-bend transitions of nephrons at all medullary depths is presented in this work together with the results of simulation of predicted flows and concentrations.

  2. Cerebrocortical and medullary blood flow changes after general opiate receptor blockade during hemorrhagic shock in cats.

    PubMed

    Komjáti, K; Sandor, P; Sandor, N; Szirmai, L; H-Velkei, M; Kovach, A G

    1997-04-01

    The effect of centrally induced opiate receptor blockade on regional cerebral blood flow (rCBF) was studied in anesthetized, ventilated cats during the course of hemorrhagic shock. The blood flow of the medulla and the parietal cortex was measured with the H2-gas clearance technique. Hemorrhagic shock was produced by lowering the systemic mean arterial pressure to 60 mmHg for 120 min by blood withdrawal. Central opiate receptor blockade was induced by 10 micrograms/kg intracerebroventricularly (i.c.v.) injected naloxone at the 60th min of the bleeding period. Cortical blood flow showed no improvement after i.c.v. naloxone administration. Medullary blood flow, however, increased significantly and approached the pre-bleeding control flow values following central opiate receptor blockade. The results indicate involvement of endogenous opioid mechanisms in the regulation of rCBF during hemorrhage and may provide an explanation for the previously described beneficial effects of naloxone in hemorrhagic shock.

  3. New radionuclide tracers for the diagnosis and therapy of medullary thyroid carcinoma

    SciTech Connect

    Hoefnagel, C.A.; Delprat, C.C.; Zanin, D.; van der Schoot, J.B.

    1988-03-01

    Medullary thyroid carcinoma (MTC), a calcitonin-producing tumor that occurs in familial and sporadic forms, can be monitored satisfactorily with measurements of calcitonin and CEA in serum. However, locating the tumor site may be difficult. In the current review of the experience with four new radionuclide tracers for MTC, the relative value of each of these procedures is outlined. Total body imaging using TI-201 chloride and Tc-99m(V) DMSA are both sensitive techniques that can be used for the detection and follow-up of MTC. Imaging using I-131 MIBG and I-131 anti-CEA antibodies/fragments should be performed once the diagnosis and the tumor site have been established, to evaluate if patients might be amenable for therapy with one of these radiopharmaceuticals.

  4. Cardiovascular and respiratory consequences of bilateral involvement of the medullary intermediate reticular formation in syringobulbia.

    PubMed

    Heidel, K M; Benarroch, E E; Gené, R; Klein, F; Meli, F; Saadia, D; Nogués, M A

    2002-12-01

    We studied five patients with clinical and radiological evidence of syringobulbia (SB) to determine whether the distribution of lesions in relationship to the cardiorespiratory control networks in the medullary intermediate reticular zone (IRt) correlates with the presence of abnormalities in autonomic cardiovascular and respiratory control in these patients. All patients underwent high resolution MRI to characterize the size, volume and distribution of the SB lesions, cardiovascular autonomic function testing and polysomnography. One patient with bilateral IRt involvement at both the rostral and caudal medulla had orthostatic hypotension (OH), absent HR(DB), abnormal Valsalva ratio, exaggerated fall of BP during phase II and absent phase IV during VM, and a dramatic fall of BP during head up tilt; this patient also had severe obstructive sleep apnea (OSA) and exhibited BP drops during each respiratory effort. A second patient, with bilateral IRt involvement restricted to the caudal medulla, had less severe cardiovascular autonomic dysfunction but also exhibited severe OSA. The other three patients had small SB cavities sparing the IRt and had sleep apnea but no autonomic dysfunction. Autonomic dysfunction could not be related to the size of the syrinx or the degree of atrophy in the cervical spinal cord in any of the five patients. Bilateral involvement of the IRt by SB produces cardiovascular autonomic failure and sleep apnea. In patients with more restricted lesions, autonomic and respiratory dysfunction may be dissociated. Clinico-radiological correlations using high resolution MRI assessment of medullary lesions can provide insight into the central organization of cardiovascular and respiratory control in humans.

  5. Changes in neurochemicals within the ventrolateral medullary respiratory column in awake goats after carotid body denervation

    PubMed Central

    Miller, Justin Robert; Neumueller, Suzanne; Muere, Clarissa; Olesiak, Samantha; Pan, Lawrence; Hodges, Matthew R.

    2013-01-01

    A current and major unanswered question is why the highly sensitive central CO2/H+ chemoreceptors do not prevent hypoventilation-induced hypercapnia following carotid body denervation (CBD). Because perturbations involving the carotid bodies affect central neuromodulator and/or neurotransmitter levels within the respiratory network, we tested the hypothesis that after CBD there is an increase in inhibitory and/or a decrease in excitatory neurochemicals within the ventrolateral medullary column (VMC) in awake goats. Microtubules for chronic use were implanted bilaterally in the VMC within or near the pre-Bötzinger Complex (preBötC) through which mock cerebrospinal fluid (mCSF) was dialyzed. Effluent mCSF was collected and analyzed for neurochemical content. The goats hypoventilated (peak +22.3 ± 3.4 mmHg PaCO2) and exhibited a reduced CO2 chemoreflex (nadir, 34.8 ± 7.4% of control ΔV̇E/ΔPaCO2) after CBD with significant but limited recovery over 30 days post-CBD. After CBD, GABA and glycine were above pre-CBD levels (266 ± 29% and 189 ± 25% of pre-CBD; P < 0.05), and glutamine and dopamine were significantly below pre-CBD levels (P < 0.05). Serotonin, substance P, and epinephrine were variable but not significantly (P > 0.05) different from control after CBD. Analyses of brainstem tissues collected 30 days after CBD exhibited 1) a midline raphe-specific reduction (P < 0.05) in the percentage of tryptophan hydroxylase–expressing neurons, and 2) a reduction (P < 0.05) in serotonin transporter density in five medullary respiratory nuclei. We conclude that after CBD, an increase in inhibitory neurotransmitters and a decrease in excitatory neuromodulation within the VMC/preBötC likely contribute to the hypoventilation and attenuated ventilatory CO2 chemoreflex. PMID:23869058

  6. Neonatal hyperleptinaemia programmes adrenal medullary function in adult rats: effects on cardiovascular parameters.

    PubMed

    Trevenzoli, I H; Valle, M M R; Machado, F B; Garcia, R M G; Passos, M C F; Lisboa, P C; Moura, E G

    2007-04-15

    Epidemiological studies have shown a strong correlation between stressful events (nutritional, hormonal or environmental) in early life and development of adult diseases such as obesity, diabetes and cardiovascular failure. It is known that gestation and lactation are crucial periods for healthy growth in mammals and that the sympathoadrenal system is markedly influenced by environmental conditions during these periods. We previously demonstrated that neonatal hyperleptinaemia in rats programmes higher body weight, higher food intake and hypothalamic leptin resistance in adulthood. Using this model of programming, we investigated adrenal medullary function and effects on cardiovascular parameters in male rats in adulthood. Leptin treatment during the first 10 days of lactation (8 microg 100 g(-1) day(-1), s.c.) resulted in lower body weight (6.5%, P < 0.05), hyperleptinaemia (10-fold, P < 0.05) and higher catecholamine content in adrenal glands (18.5%, P < 0.05) on the last day of treatment. In adulthood (150 days), the rats presented higher body weight (5%, P < 0.05), adrenal catecholamine content (3-fold, P < 0.05), tyrosine hydroxylase expression (35%, P < 0.05) and basal and caffeine-stimulated catecholamine release (53% and 100%, respectively, P < 0.05). Systolic blood pressure and heart rate were also higher in adult rats (7% and 6%, respectively, P < 0.05). Our results show that hyperleptinaemia in early life increases adrenal medullary function in adulthood and that this may alter cardiovascular parameters. Thus, we suggest that imprinting factors which increase leptin and catecholamine levels during the neonatal period could be involved in development of adult chronic diseases.

  7. Analysis of Oxygen Spectral Lines in the 1.27 Micron Band for the ASCENDS Mission

    NASA Technical Reports Server (NTRS)

    Pliutau, Denis; Prasad, Narasimha S.

    2011-01-01

    The ASCENDS mission requires simultaneous laser remote sensing of CO2 and O2 in order to convert CO2 column number densities to average column CO2 mixing ratios (XCO2). As such, the CO2 column number density and the O2 column number density will be utilized to derive the average XCO2 column. NASA Langley Research Center, working with its partners, is developing O2 lidar technology in the 1.26-1.27- m band for surface pressure measurements. The O2 model optical depth calculation is very sensitive to knowledge of the transmitted wavelengths and to the choice of Voigt input parameters. Modeling using the HITRAN database is being carried out to establish the evolution of candidate O2 absorption lines as a function of atmospheric parameters such as altitude, temperature, and pressure. Preliminary results indicate limitations of the Voigt profile and the need to utilize more advanced models which take into account line mixing, line narrowing, and speed dependence. In this paper, we evaluate alternative lineshape models to establish the optimum lineshapes which better account for the variability of individual O2 absorption lines at various atmospheric conditions. The combination of our modeling efforts with accurate laboratory measurements is anticipated to aid in achieving the desired CO2 mixing ratio measurement accuracy requirement of for the ASCENDS mission.

  8. [Primary squamous cell carcinoma of the ascending colon: report of a case and Korean literature review].

    PubMed

    Cho, Dong Keun; Kim, Sang Hun; Cho, Sung Bum; Lee, Wan Sik; Joo, Young Eun

    2014-08-01

    Primary squamous cell carcinoma of the colon is an extremely rare malignancy. A 48-year-old male visited our hospital for screening colonoscopy. Colonoscopic examination showed a 1 cm sized sessile polyp in the ascending colon. The patient underwent endoscopic mucosal resection (EMR) without any complication. The pathologic findings were compatible with squamous differentiation of tumor cells in inflammatory colonic mucosa. The tumor was confined to the mucosa and the margins of the excised tissue were found to be free of the tumor. There were no other primary sites and no distant metastases in the extensive evaluation using a whole body CT scan and PET-CT. Additional surgical resection was not done. Follow-up colonoscopy performed eight month later showed a whitish scar without evidence of local recurrence and follow-up PET-CT demonstrated no evidence of recurrence. Herein, we report a case of primary squamous cell carcinoma of the ascending colon presenting as a sessile polyp which was removed by EMR.

  9. Experimental investigation of the influence of the aortic stiffness on hemodynamics in the ascending aorta.

    PubMed

    Gülan, Utku; Lüthi, Beat; Holzner, Markus; Liberzon, Alex; Tsinober, Arkady; Kinzelbach, Wolfgang

    2014-11-01

    A three-dimensional (3-D) pulsatile aortic flow in a human ascending aorta is studied to investigate the effect of the aortic stiffness on the flow field and turbulent fluctuating velocities in the ascending aorta. A nonintrusive optical measurement technique, 3-D particle tracking velocimetry (3D-PTV), has been applied to anatomically accurate phantoms under clinically realistic conditions. A compliant silicon phantom was used to mimic the healthy aorta, and a rigid model was used to imitate the pathological case that appears in aortas for example as a result of aging. The realistic models are transparent which allows optical access to the investigation domain, and the index of refraction was matched to avoid optical distortions. Our results revealed that the aortic stiffness leads to an increase in systolic velocity and a decrease in the Windkessel effect, which is associated with the diastolic blood pressure. Furthermore, we found that the turbulent kinetic energy is about an order of magnitude higher for the rigid aorta, that is, an increase in aortic stiffness increases the magnitude of turbulent fluctuating velocities. The spatial distribution of the flow velocity showed that the flow is more organized and coherent spiraling patterns develop for the compliant aorta which helps to dampen the influence of disturbed flow. Finally, we observed higher Lagrangian acceleration and hence higher instantaneous forces acting on blood particles in the stiff case which implies that aging and hence arterial stiffening provokes distinctive alterations in blood flow, and these alterations may cause pathological symptoms in the cardiovascular system.

  10. Dilation of the ascending aorta in Turner syndrome - a prospective cardiovascular magnetic resonance study

    PubMed Central

    2011-01-01

    Background The risk of aortic dissection is 100-fold increased in Turner syndrome (TS). Unfortunately, risk stratification is inadequate due to a lack of insight into the natural course of the syndrome-associated aortopathy. Therefore, this study aimed to prospectively assess aortic dimensions in TS. Methods Eighty adult TS patients were examined twice with a mean follow-up of 2.4 ± 0.4 years, and 67 healthy age and gender-matched controls were examined once. Aortic dimensions were measured at nine predefined positions using 3D, non-contrast and free-breathing cardiovascular magnetic resonance. Transthoracic echocardiography and 24-hour ambulatory blood pressure were also performed. Results At baseline, aortic diameters (body surface area indexed) were larger at all positions in TS. Aortic dilation was more prevalent at all positions excluding the distal transverse aortic arch. Aortic diameter increased in the aortic sinus, at the sinotubular junction and in the mid-ascending aorta with growth rates of 0.1 - 0.4 mm/year. Aortic diameters at all other positions were unchanged. The bicuspid aortic valve conferred higher aortic sinus growth rates (p < 0.05). No other predictors of aortic growth were identified. Conclusion A general aortopathy is present in TS with enlargement of the ascending aorta, which is accelerated in the presence of a bicuspid aortic valve. PMID:21527014

  11. Local control of information flow in segmental and ascending collaterals of single afferents.

    PubMed

    Lomelí, J; Quevedo, J; Linares, P; Rudomin, P

    1998-10-08

    In the vertebrate spinal cord, the activation of GABA(gamma-amino-butyric acid)-releasing interneurons that synapse with intraspinal terminals of sensory fibres leading into the central nervous system (afferent fibres) produces primary afferent depolarization and presynaptic inhibition. It is not known to what extent these presynaptic mechanisms allow a selective control of information transmitted through specific sets of intraspinal branches of individual afferents. Here we study the local nature of the presynaptic control by measuring primary afferent depolarization simultaneously in two intraspinal collaterals of the same muscle spindle afferent. One of these collaterals ends at the L6-L7 segmental level in the intermediate nucleus, and the other ascends to segment L3 within Clarke's column, the site of origin of spinocerebellar neurons. Our results indicate that there are central mechanisms that are able to affect independently the synaptic effectiveness of segmental and ascending collaterals of individual muscle spindle afferents. Focal control of presynaptic inhibition thus allows the intraspinal branches of afferent fibres to function as a dynamic assembly that can be fractionated to convey information to selected neuronal targets. This may be a mechanism by which different spinal postsynaptic targets that are coupled by sensory input from a common source could be uncoupled.

  12. Pairing broadband noise with cortical stimulation induces extensive suppression of ascending sensory activity

    NASA Astrophysics Data System (ADS)

    Markovitz, Craig D.; Hogan, Patrick S.; Wesen, Kyle A.; Lim, Hubert H.

    2015-04-01

    Objective. The corticofugal system can alter coding along the ascending sensory pathway. Within the auditory system, electrical stimulation of the auditory cortex (AC) paired with a pure tone can cause egocentric shifts in the tuning of auditory neurons, making them more sensitive to the pure tone frequency. Since tinnitus has been linked with hyperactivity across auditory neurons, we sought to develop a new neuromodulation approach that could suppress a wide range of neurons rather than enhance specific frequency-tuned neurons. Approach. We performed experiments in the guinea pig to assess the effects of cortical stimulation paired with broadband noise (PN-Stim) on ascending auditory activity within the central nucleus of the inferior colliculus (CNIC), a widely studied region for AC stimulation paradigms. Main results. All eight stimulated AC subregions induced extensive suppression of activity across the CNIC that was not possible with noise stimulation alone. This suppression built up over time and remained after the PN-Stim paradigm. Significance. We propose that the corticofugal system is designed to decrease the brain’s input gain to irrelevant stimuli and PN-Stim is able to artificially amplify this effect to suppress neural firing across the auditory system. The PN-Stim concept may have potential for treating tinnitus and other neurological disorders.

  13. Ascending retrocecal appendicitis presenting with right upper abdominal pain: Utility of computed tomography

    PubMed Central

    Ong, Eugene Mun Wai; Venkatesh, Sudhakar Kundapur

    2009-01-01

    Acute appendicitis is a common surgical condition that is usually managed with early surgery, and is associated with low morbidity and mortality. However, some patients may have atypical symptoms and physical findings that may lead to a delay in diagnosis and increased complications. Atypical presentation may be related to the position of the appendix. Ascending retrocecal appendicitis presenting with right upper abdominal pain may be clinically indistinguishable from acute pathology in the gallbladder, liver, biliary tree, right kidney and right urinary tract. We report a series of four patients with retrocecal appendicitis who presented with acute right upper abdominal pain. The clinical diagnoses at presentation were acute cholecystitis in two patients, pyelonephritis in one, and ureteric colic in one. Ultrasound examination of the abdomen at presentation showed subhepatic collections in two patients and normal findings in the other two. Computed tomography (CT) identified correctly retrocecal appendicitis and inflammation in the retroperitoneum in all cases. In addition, abscesses in the retrocecal space (n = 2) and subhepatic collections (n = 2) were also demonstrated. Emergency appendectomy was performed in two patients, interval appendectomy in one, and hemicolectomy in another. Surgical findings confirmed the presence of appendicitis and its retroperitoneal extensions. Our case series illustrates the usefulness of CT in diagnosing ascending retrocecal appendicitis and its extension, and excluding other inflammatory conditions that mimic appendicitis. PMID:19630119

  14. Ascending midbrain dopaminergic axons require descending GAD65 axon fascicles for normal pathfinding

    PubMed Central

    García-Peña, Claudia M.; Kim, Minkyung; Frade-Pérez, Daniela; Ávila-González, Daniela; Téllez, Elisa; Mastick, Grant S.; Tamariz, Elisa; Varela-Echavarría, Alfredo

    2014-01-01

    The Nigrostriatal pathway (NSP) is formed by dopaminergic axons that project from the ventral midbrain to the dorsolateral striatum as part of the medial forebrain bundle. Previous studies have implicated chemotropic proteins in the formation of the NSP during development but little is known of the role of substrate-anchored signals in this process. We observed in mouse and rat embryos that midbrain dopaminergic axons ascend in close apposition to descending GAD65-positive axon bundles throughout their trajectory to the striatum. To test whether such interaction is important for dopaminergic axon pathfinding, we analyzed transgenic mouse embryos in which the GAD65 axon bundle was reduced by the conditional expression of the diphtheria toxin. In these embryos we observed dopaminergic misprojection into the hypothalamic region and abnormal projection in the striatum. In addition, analysis of Robo1/2 and Slit1/2 knockout embryos revealed that the previously described dopaminergic misprojection in these embryos is accompanied by severe alterations in the GAD65 axon scaffold. Additional studies with cultured dopaminergic neurons and whole embryos suggest that NCAM and Robo proteins are involved in the interaction of GAD65 and dopaminergic axons. These results indicate that the fasciculation between descending GAD65 axon bundles and ascending dopaminergic axons is required for the stereotypical NSP formation during brain development and that known guidance cues may determine this projection indirectly by instructing the pathfinding of the axons that are part of the GAD65 axon scaffold. PMID:24926237

  15. Plume Ascent Tracker: Interactive Matlab software for analysis of ascending plumes in image data

    NASA Astrophysics Data System (ADS)

    Valade, S. A.; Harris, A. J. L.; Cerminara, M.

    2014-05-01

    This paper presents Matlab-based software designed to track and analyze an ascending plume as it rises above its source, in image data. It reads data recorded in various formats (video files, image files, or web-camera image streams), and at various wavelengths (infrared, visible, or ultra-violet). Using a set of filters which can be set interactively, the plume is first isolated from its background. A user-friendly interface then allows tracking of plume ascent and various parameters that characterize plume evolution during emission and ascent. These include records of plume height, velocity, acceleration, shape, volume, ash (fine-particle) loading, spreading rate, entrainment coefficient and inclination angle, as well as axial and radial profiles for radius and temperature (if data are radiometric). Image transformations (dilatation, rotation, resampling) can be performed to create new images with a vent-centered metric coordinate system. Applications may interest both plume observers (monitoring agencies) and modelers. For the first group, the software is capable of providing quantitative assessments of plume characteristics from image data, for post-event analysis or in near real-time analysis. For the second group, extracted data can serve as benchmarks for plume ascent models, and as inputs for cloud dispersal models. We here describe the software's tracking methodology and main graphical interfaces, using thermal infrared image data of an ascending volcanic ash plume at Santiaguito volcano.

  16. Transcatheter valve implantation can alter fluid flow fields in aortic sinuses and ascending aorta

    NASA Astrophysics Data System (ADS)

    Saikrishnan, Neelakantan; Yoganathan, Ajit

    2012-11-01

    Transcatheter aortic valves (TAVs) are valve replacements used to treat aortic stenosis. Currently, these have been used in elderly patients at high-risk for open-heart procedures. Since these devices are implanted under fluoroscopic guidance, the implantation position of the valve can vary with respect to the native aortic valve annulus. The current study characterizes the altered hemodynamics in the aortic sinus and ascending aorta under different implantation (high and low) and cardiac output (2.5 and 5.0 L/min) conditions. Two commonly used TAV designs are studied using 2-D Particle Image Velocimetry (PIV). 200 phase locked images are obtained at every 25ms in the cardiac cycle, and the resulting vector fields are ensemble averaged. High implantation of the TAV with respect to the annulus causes weaker sinus washout and weaker sinus vortex formation. Additionally, the longer TAV leaflets can also result in a weaker sinus vortex. The level of turbulent fluctuations in the ascending aorta did not appear to be affected by axial positioning of the valve, but varied with cardiac output. The results of this study indicates that TAV positioning is important to be considered clinically, since this can affect coronary perfusion and potential flow stagnation near the valve.

  17. Acute effects of an ascending intensity squat protocol on vertical jump performance.

    PubMed

    Hirayama, Kuniaki

    2014-05-01

    The purpose of this study was to examine the acute effects of an ascending intensity squat protocol consisting of single-repetition exercises on subsequent vertical jump performance. Fourteen college weightlifters attended 2 testing sessions: squat (SQ) and control (CON) conditions. In the SQ condition, squat exercises with incremental loads (20% 1 repetition maximum [RM], 40% 1RM, 60% 1RM, 80% 1RM, and maximal isometric [MI] half-squat exercise) were performed with a time interval of 3 minutes after submaximal cycling and static stretching. Maximum vertical jump height was measured at the beginning of the session and after cycling, static stretching, and each squat exercise in the SQ condition. In the CON condition, vertical jump height was measured at the same times with the subject resting on a chair after cycling and stretching. Vertical jump height gradually increased after 60% 1RM, 80% 1RM, and MI half-squat exercises compared with baseline values (i.e., first trial of vertical jump), whereas no change was observed in the CON condition. These results suggest that an ascending intensity squat protocol consisting of single-repetition exercises of sufficient intensity can be useful for athletes who require high muscular power.

  18. Observing System Simulations for the NASA ASCENDS Lidar CO2 Mission Concept: Substantiating Science Measurement Requirements

    NASA Technical Reports Server (NTRS)

    Kawa, Stephan R.; Baker, David Frank; Schuh, Andrew E.; Abshire, James Brice; Browell, Edward V.; Michalak, Anna M.

    2012-01-01

    The NASA ASCENDS mission (Active Sensing of Carbon Emissions, Nights, Days, and Seasons) is envisioned as the next generation of dedicated, space-based CO2 observing systems, currently planned for launch in about the year 2022. Recommended by the US National Academy of Sciences Decadal Survey, active (lidar) sensing of CO2 from space has several potentially significant advantages, in comparison to current and planned passive CO2 instruments, that promise to advance CO2 measurement capability and carbon cycle understanding into the next decade. Assessment and testing of possible lidar instrument technologies indicates that such sensors are more than feasible, however, the measurement precision and accuracy requirements remain at unprecedented levels of stringency. It is, therefore, important to quantitatively and consistently evaluate the measurement capabilities and requirements for the prospective active system in the context of advancing our knowledge of carbon flux distributions and their dependence on underlying physical processes. This amounts to establishing minimum requirements for precision, relative accuracy, spatial/temporal coverage and resolution, vertical information content, interferences, and possibly the tradeoffs among these parameters, while at the same time framing a mission that can be implemented within a constrained budget. Here, we present results of observing system simulation studies, commissioned by the ASCENDS Science Requirements Definition Team, for a range of possible mission implementation options that are intended to substantiate science measurement requirements for a laser-based CO2 space instrument.

  19. Pairing broadband noise with cortical stimulation induces extensive suppression of ascending sensory activity

    PubMed Central

    Markovitz, Craig D.; Hogan, Patrick S.; Wesen, Kyle A.; Lim, Hubert H.

    2015-01-01

    Objective The corticofugal system can alter coding along the ascending sensory pathway. Within the auditory system, electrical stimulation of the auditory cortex (AC) paired with a pure tone can cause egocentric shifts in the tuning of auditory neurons, making them more sensitive to the pure tone frequency. Since tinnitus has been linked with hyperactivity across auditory neurons, we sought to develop a new neuromodulation approach that could suppress a wide range of neurons rather than enhance specific frequency-tuned neurons. Approach We performed experiments in the guinea pig to assess the effects of cortical stimulation paired with broadband noise (PN-Stim) on ascending auditory activity within the central nucleus of the inferior colliculus (CNIC), a widely studied region for AC stimulation paradigms. Main results All eight stimulated AC regions induced extensive suppression of activity across the CNIC that was not possible with noise stimulation alone. This suppression built up over time and remained after the PN-Stim paradigm. Significance We propose that the corticofugal system is designed to decrease the brain’s input gain to irrelevant stimuli and PN-Stim is able to artificially amplify this effect to suppress neural firing across the auditory system. The PN-Stim concept may have potential for treating tinnitus and other neurological disorders. PMID:25686163

  20. Cellular transport of l-arginine determines renal medullary blood flow in control rats, but not in diabetic rats despite enhanced cellular uptake capacity.

    PubMed

    Persson, Patrik; Fasching, Angelica; Teerlink, Tom; Hansell, Peter; Palm, Fredrik

    2017-02-01

    Diabetes mellitus is associated with decreased nitric oxide bioavailability thereby affecting renal blood flow regulation. Previous reports have demonstrated that cellular uptake of l-arginine is rate limiting for nitric oxide production and that plasma l-arginine concentration is decreased in diabetes. We therefore investigated whether regional renal blood flow regulation is affected by cellular l-arginine uptake in streptozotocin-induced diabetic rats. Rats were anesthetized with thiobutabarbital, and the left kidney was exposed. Total, cortical, and medullary renal blood flow was investigated before and after renal artery infusion of increasing doses of either l-homoarginine to inhibit cellular uptake of l-arginine or N(ω)-nitro- l-arginine methyl ester (l-NAME) to inhibit nitric oxide synthase. l-Homoarginine infusion did not affect total or cortical blood flow in any of the groups, but caused a dose-dependent reduction in medullary blood flow. l-NAME decreased total, cortical and medullary blood flow in both groups. However, the reductions in medullary blood flow in response to both l-homoarginine and l-NAME were more pronounced in the control groups compared with the diabetic groups. Isolated cortical tubular cells displayed similar l-arginine uptake capacity whereas medullary tubular cells isolated from diabetic rats had increased l-arginine uptake capacity. Diabetics had reduced l-arginine concentrations in plasma and medullary tissue but increased l-arginine concentration in cortical tissue. In conclusion, the reduced l-arginine availability in plasma and medullary tissue in diabetes results in reduced nitric oxide-mediated regulation of renal medullary hemodynamics. Cortical blood flow regulation displays less dependency on extracellular l-arginine and the upregulated cortical tissue l-arginine may protect cortical hemodynamics in diabetes.

  1. Results of a screening program for C-cell disease (medullary thyroid cancer and C-cell hyperplasia).

    PubMed

    Simpson, W J; Carruthers, J S; Malkin, D

    1990-04-01

    In the authors' Medullary Screening Clinic, medullary thyroid cancer (MTC) or C-cell hyperplasia (CCH) has been identified in 26 relatives of 12 apparently "sporadic" patients from 56 families in which calcitonin (CT) testing has been performed. The interpretation of stimulated test results was sometimes difficult: elevated basal levels without a significant increase after the injection of secretagogues; basal levels in the normal range with considerable increases after stimulation but not exceeding two or three times the upper limit of normal; elevated basal or stimulated CT levels that slowly decreased to normal or near-normal levels over relatively short periods of time. The latter results suggest the possibility of CCH disappearing spontaneously in some patients.

  2. Face-arm-trunk-leg sensory loss limited to the contralateral side in lateral medullary infarction: a new variant.

    PubMed

    Vaudens, P; Bogousslavsky, J

    1998-08-01

    Two patients are reported on who experienced loss of pain and temperature sensation in the entire contralateral hemibody but sparing the ispsilateral face (pure sensory stroke pattern) related to acute lateral medullary infarction. In both patients MRI showed a notch-like retro-olivary ischaemic lesion in the ventromedial tegmentum with preservation of the far lateral medulla. The mediolateral lesion involved the crossed lateral spinothalamic tract and the ventral trigeminothalamic tract, corresponding to sensory loss in the contralateral face, arm, and upper trunk. The ventrolateral extension of infarct damaged the far lateral part of the spinothalamic tract, corresponding to sensory loss in the contralateral lower trunk and leg. The findings suggest that hemisensory loss of the spinothalamic type involving-and limited to-the whole hemibody can occur in infarction in the lower brainstem. This form of pure sensory stroke may be classified as type IV of sensory loss in lateral medullary infarction.

  3. [A case of conus medullaris infarction expanding to the vertebral bodies, major psoas and erector spinae muscles].

    PubMed

    Konno, Takuya; Suwabe, Tatsuya; Kasahara, Sou; Umeda, Yoshitaka; Oyake, Mutsuo; Fujita, Nobuya

    2015-01-01

    A 77-year-old woman presented with conus medullaris and cauda equina syndrome following a sudden pain in the bilateral lower abdomen and right buttock. Lumbar magnetic resonance imaging (MRI) showed not only a conus medullaris lesion, but also several lesions in the vertebral bodies (L1, L2), right major psoas muscle, right multifidus muscle and bilateral erector spinae muscles. As these areas receive blood supply from each branch of the same segmental artery, we considered all of the lesions as infarctions that were a result of a single parent vessel occlusion. It is known that a vertebral body lesion can be accompanied by a spinal cord infarction, but in combination with infarction of a muscle has not been reported. This is the first report of a concomitant spinal cord and muscle infarction revealed by MRI. It is noteworthy that a spinal cord infarction could expand not only to neighboring vertebral bodies, but also to muscles.

  4. On the Ability of Ascends to Constrain Fossil Fuel, Ocean and High Latitude Emissions: Flux Estimation Experiments

    NASA Astrophysics Data System (ADS)

    Crowell, S.; Kawa, S. R.; Hammerling, D.; Moore, B., III; Rayner, P. J.

    2014-12-01

    In Hammerling et al., 2014 (H14) the authors demonstrated a geostatistical method for mapping satellite estimates of column integrated CO2 mixing ratio, denoted XCO2, that incorporates the spatial variability in satellite-measured XCO2 as well as measurement precision. The goal of the study was to determine whether the Active Sensing of CO2 over Nights, Days and Seasons (ASCENDS) mission would be able to detect changes in XCO2 given changes in the underlying fluxes for different levels of instrument precision. Three scenarios were proposed: a flux-neutral shift in fossil fuel emissions from Europe to China (shown in the figure); a permafrost melting event; interannual variability in the Southern Oceans. The conclusions of H14 were modest but favorable for detectability in each case by ASCENDS given enough observations and sufficient precision. These signal detection experiments suggest that ASCENDS observations, together with a chemical transport model and data assimilation methodology, would be sufficient to provide quality estimates of the underlying surface fluxes, so long as the ASCENDS observations are precise enough. In this work, we present results that bridge the gap between the previous signal detection work by [Hammerling et al., 2014] and the ability of transport models to recover flux perturbations from ASCENDS observations utilizing the TM5-4DVAR data assimilation system. In particular, we will explore the space of model and observational uncertainties that will yield useful scientific information in each of the flux perturbation scenarios. This work will give a sense of the ability of ASCENDS to answer key questions about some of the foremost questions in carbon cycle science today. References: Hammerling, D., Kawa, S., Schaefer, K., and Michalak, A. (2014). Detectability of CO2 flux signals by a space-based lidar mission. Submitted.

  5. Depletion of medullary serotonergic neurons in patients with multiple system atrophy who succumbed to sudden death.

    PubMed

    Tada, Mari; Kakita, Akiyoshi; Toyoshima, Yasuko; Onodera, Osamu; Ozawa, Tetsutaro; Morita, Takashi; Nishizawa, Masatoyo; Takahashi, Hitoshi

    2009-07-01

    Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by prominent autonomic failure with ataxia and/or parkinsonism. The leading cause of death in MSA is sudden death. We have shown that the early development of autonomic failure is an independent risk factor for sudden death. The depletion of sympathetic preganglionic neurons in the spinal intermediolateral cell column (IML) and its afferent medullary catecholaminergic and serotonergic neurons has been proposed to be partly responsible for autonomic failure in MSA. In this study, we investigated whether the depletion of neurons in any of these autonomic neuron groups contributes to sudden death in MSA. Out of 52 autopsy-proven patients with MSA, we selected 12 individuals who had died within 3.5 years after disease onset to define the accurate levels of slices and identify early neuropathological changes of autonomic nuclei in MSA. Four patients succumbed to sudden death and eight patients died through established causes. Serial 10 mum sections were obtained from the 8th segment of the thoracic cord and the rostral medulla oblongata. Sections from the medulla oblongata were immunostained for thyrosine hydroxylase and tryptophan hydroxylase. The total cell number in the five sections was computed for comparison. Compared with the control, the MSA group showed a marked depletion of neurons in the IML (38.0 +/- 7.1 versus 75.2 +/- 7.6 cells, P < 0.001), thyrosine hydroxylase-immunoreactive neurons in the ventrolateral medulla (VLM) (17.4 +/- 5.1 versus 72.8 +/- 13.6 cells, P < 0.01) and tryptophan hydroxylase-immunoreactive neurons in the VLM (15.6 +/- 9.2 versus 60.8 +/- 17.0 cells, P < 0.01), nucleus raphe obscurus (19.3 +/- 4.4 versus 75.3 +/- 8.6 cells, P < 0.001), nucleus raphe pallidus (2.1 +/- 2.7 versus 9.0 +/- 3.4 cells, P < 0.03), and arcuate nucleus (0.4 +/- 0.8 versus 2.3 +/- 1.5 cells, P < 0.05). Moreover, in patients who succumbed to sudden death, when compared with patients who

  6. Inhibition of medullary raphe serotonergic neurons has age-dependent effects on the CO2 response in newborn piglets.

    PubMed

    Messier, Michelle L; Li, Aihua; Nattie, Eugene E

    2004-05-01

    Medullary raphé serotonergic neurons are chemosensitive in culture and are situated adjacent to blood vessels in the brain stem. Selective lesioning of serotonergic raphé neurons decreases the ventilatory response to systemic CO2 in awake and sleeping adult rats. Abnormalities in the medullary serotonergic system, including the raphé, have been implicated in the sudden infant death syndrome (48). In this study, we ask whether serotonergic neurons in the medullary raphé and extra-raphé regions are involved in the CO2 response in unanesthetized newborn piglets, 3-16 days old. Whole body plethysmography was used to examine the ventilatory response to 5% CO2 before and during focal inhibition of serotonergic neurons by 8-hydroxy-2-di-n-propylaminotetralin (8-OH-DPAT), a 5-HT1A receptor agonist. 8-OH-DPAT (10 or 30 mM in artificial cerebrospinal fluid) decreased the CO2 response in wakefulness in an age-dependent manner, as revealed by a linear regression analysis that showed a significant negative correlation (P < 0.001) between the percent change in the CO2 response and piglet age. Younger piglets showed an exaggerated CO2 response. Control dialysis with artificial cerebrospinal fluid had no significant effect on the CO2 response. Additionally, 8-OH-DPAT increased blood pressure and decreased heart rate independent of age (P < 0.05). Finally, sleep cycling was disrupted by 8-OH-DPAT, such that piglets were awake more and asleep less (P < 0.05). Because of the fragmentary sleep data, it was not possible to examine the CO2 response in sleep. Inhibition of serotonergic medullary raphé and extra-raphé neurons decreases ventilatory CO2 sensitivity and alters cardiovascular variables and sleep cycling, which may contribute to the sudden infant death syndrome.

  7. Determination of catecholamines in single adrenal medullary cells by capillary electrophoresis and laser-induced native fluorescence

    SciTech Connect

    Chang, H.T.; Yeung, E.S. |

    1995-03-15

    The present study demonstrates that native fluroescence detection combined with capillary electrophoresis separation at low pH provides high sensitivity (down to nanomolar), high resolution, high speed, and low interference for the analysis of catecholamines. Further, this method has been employed successfully for the measurement of the amounts of epinephrine and norepinephrine in individual bovine adrenal medullary cells. Application of this method to the study of neurochemistry is promising. 46 refs., 7 figs., 2 tabs.

  8. Vascular complication involving the conus medullaris or cauda equina after vertebral manipulation for an L4-L5 disk herniation.

    PubMed

    Balblanc, J C; Pretot, C; Ziegler, F

    1998-04-01

    A case of injury to the cauda equina or conus medullaris after lumbar vertebral manipulation is reported. In contrast to all other previously reported cases, no migrated disk fragment was demonstrated. Similar to experience at the cervical spine, lumbar vertebral manipulation may carry a risk of vascular injury. The neurological manifestations in our patient were consistent with compression of the Desproges-Gotteron artery by a small L4-L5 disk herniation.

  9. Subacute post-traumatic ascending myelopathy (SPAM): two cases of SPAM following surgical treatment of thoracolumbar fractures.

    PubMed

    Farooque, Kamran; Kandwal, Pankaj; Gupta, Ankit

    2014-01-01

    To report two cases of traumatic paraplegia who developed Sub-acute Post-Traumatic Ascending Myelopathy (SPAM) following surgical decompression.We hereby report two cases (both 35yr old male) with traumatic paraplegia that developed ascending weakness at 3rd and 5th Post-Op day respectively following surgical decompression. Both the patients experienced remarkable improvement in Neurology after treatment with steroids. The authors conclude by emphasizing on minimum cord handling during surgical decompression of the spinal cord to avoid this potentially life threatening complication.

  10. Single coronary artery with bicuspid aortic valve stenosis and aneurysm of the ascending aorta: report of a case.

    PubMed

    Ishida, Narihiro; Shimabukuro, Katsuya; Matsuno, Yukihiro; Ogura, Hiroki; Takemura, Hirofumi

    2014-03-01

    A 73-year-old man with a severely stenosed bicuspid valve and an aneurysm of the ascending aorta underwent valve and aortic surgery. Preoperative imaging revealed a single coronary artery arising from the right side of the sinus of Valsalva and a branch that perfused into the left side of the heart to pass through the front of the pulmonary artery. We replaced the aortic valve and ascending aorta, painstakingly avoiding damage to the coronary artery and obstruction of the sole coronary ostium.

  11. Anomalous left-to-right shunting communication between the ascending aorta and right pulmonary artery in a dog.

    PubMed

    Scollan, Katherine; Salinardi, Brenda; Bulmer, Barret J; Sisson, D David

    2011-06-01

    Anomalies of conotruncal septation are rare in dogs and uncommon in humans. Congenital conotruncal defects most commonly reported in veterinary medicine include aorto-pulmonary window and persistent truncus arteriosus. We report a case of an anomalous vessel connecting the ascending aorta to the right pulmonary artery causing left-to-right shunting, left-sided volume overload, and pulmonary overcirculation. Transesophageal echocardiography, cardiac catheterization, and contrast-enhanced computed tomography assisted in the diagnosis and facilitated the surgical correction of the anomalous vessel. The authors hypothesize this defect represents an unusual anomalous vessel connecting the ascending aorta to the right pulmonary artery.

  12. Ascending paresis as presentation of an unusual association between necrotizing autoimmune myopathy and systemic lupus erythematosus.

    PubMed

    García-Reynoso, Marco Julio; Veramendi-Espinoza, Liz Eliana; Ruiz-Garcia, Henry Jeison

    2014-01-01

    A 45 year-old man went to the emergency room due to disease duration of 15 days of insidious onset and progressive course. It began with symmetrical weakness and pain in feet and ankles that extends upward to the knees. Later, this progressed to paraparesis with Creatine phosphokinase levels of 44,270 U/L and respiratory failure that required mechanical ventilation. Electromyography and muscle biopsy of quadriceps were made. The patient responded to corticotherapy in pulses and supporting management. The presentation of ascending paresis suggested the diagnosis of Guillain-Barré syndrome. However, the degree of muscle involvement with rhabdomyolysis explains the neurological damage by itself. The biopsy revealed pathological criteria for necrotizing autoimmune myopathy (NAM), as well as other clinical and laboratory evidence. Patient disease continued and reached criteria for systemic lupus erythematosus (SLE). To our best knowledge, this is the first report of the NAM and SLE association.

  13. A case of very well-differentiated adenocarcinoma with carcinoid tumor in the ascending colon.

    PubMed

    Yamauchi, Hayato; Sakurai, Shinji; Tsukagoshi, Ritsuko; Suzuki, Masaki; Tabe, Yuichi; Fukasawa, Takaharu; Kiriyama, Shinsuke; Fukuchi, Minoru; Naitoh, Hiroshi; Kuwano, Hiroyuki

    2014-01-01

    Malignant tumors with mixed glandular and neuroendocrine characteristics with at least 30% of each component are classified as mixed adenoneuroendocrine carcinoma (MANEC) by the World Health Organization 2010 classification. We report here a case of very well-differentiated adenocarcinoma accompanied by carcinoid tumor, categorized as MANEC. A 41-year-old Japanese man was clinically diagnosed with ascending colon cancer and underwent right hemicolectomy. Using an immunohistologic technique, the pathologic diagnosis was very well-differentiated adenocarcinoma accompanied by carcinoid tumor and marked eosinophil infiltration, which was categorized as MANEC. By immunohistochemical analysis, tumor cells of the carcinoid component exhibited very low proliferation activity. Our case was thought to be MANEC without high malignant potential. MANEC as per the World Health Organization 2010 classification seems to include tumors with diverse grades of malignancy, and it might need to have subclassifications according to the malignancy potential of the tumor cells.

  14. Hysteresis in response to descending and ascending lower-body negative pressure

    NASA Technical Reports Server (NTRS)

    Tomaselli, Clare Marie; Frey, Mary Anne Bassett; Kenney, Richard A.; Hoffler, G. Wyckliffe

    1987-01-01

    Changes in the indices of fluid redistribution and cardiovascular responses during graduated orthostatic stress were measured in 12 men subjected for 25 min to lower-body negative pressure (LBNP) test protocol that involved stepwise decreases (from the starting pressure of -8 to the final -50 mm Hg), followed by stepwise increases (back to -8 mm Hg) of LBNP. The values of many variables measured during the descending phase of LBNP were significantly different from the respective values measured during the ascending phase. These differences appear to be caused by a component of fluid translocation that occurs during LBNP and cannot be reversed within the duration of the procedure. It is hypothesized that this slowly-reversed component is the sequestration of fluid in the interstitial and the lymphatic compartments.

  15. Predictive Models with Patient Specific Material Properties for the Biomechanical Behavior of Ascending Thoracic Aneurysms.

    PubMed

    Trabelsi, Olfa; Duprey, Ambroise; Favre, Jean-Pierre; Avril, Stéphane

    2016-01-01

    The aim of this study is to identify the patient-specific material properties of ascending thoracic aortic aneurysms (ATAA) using preoperative dynamic gated computed tomography (CT) scans. The identification is based on the simultaneous minimization of two cost functions, which define the difference between model predictions and gated CT measurements of the aneurysm volume at respectively systole and cardiac mid-cycle. The method is applied on five patients who underwent surgical repair of their ATAA at the University Hospital Center of St. Etienne. For these patients, the aneurysms were collected and tested mechanically using an in vitro bench. For the sake of validation, the mechanical properties found using the in vivo approach and the in vitro bench were compared. We eventually performed finite-element stress analyses based on each set of material properties. Rupture risk indexes were estimated and compared, showing promising results of the patient-specific identification method based on gated CT.

  16. Dissection of Ascending Aorta After Aortic Valve Replacement and Reduction Aortoplasty.

    PubMed

    Hashmi, Maria; Dar, Mudasser Iqbal; Khan, Asad Ullah; Khan, Farhan; Khan, Abdul Bari

    2015-12-01

    A case of Debakey type-II (Stanford type-A) dissecting aortic aneurysm, after aortic valve replacement and reduction aortoplasty, is reported. The patient was 35 years male who was diagnosed of severe aortic regurgitation along with aortic root dilatation of 7 cm. He underwent aortic valve replacement with 27-ASt Jude's mechanical aortic valve along with reduction aortoplasty. Nine months later, he was admitted to our hospital with complaint of severe sudden anterior chest pain. Computed tomography with aortic enhancement showed dilatation and dissection of ascending aorta. Successful operation of aortic root replacement with composite graft was performed and patient was discharged without any postoperative complication. The aortic diameter at the time of aortic valve replacement is an independent risk factor for the late aortic dissection.

  17. Jejunal Diverticulitis Ascending to the Duodenum as a Rare Cause of Acute Abdomen

    PubMed Central

    Fresow, Robert; Kamusella, Peter; Talanow, Roland; Andresen, Reimer

    2014-01-01

    We present the case of a 73 year-old Caucasian male with acute abdominal pain, peritonism and vomiting. Due to the severity of symptoms a CT examination of the abdomen was performed. The scans revealed multiple jejunal diverticula, wall thickening of the duodenum and jejunum, and free peritoneal fluid. No clear signs of mesenteric infarction, free abdominal air or abscess formation were seen. An additional exploratory laparotomy was conducted to confirm the CT findings and rule out the need for resection of small bowel. Since the results were matching, conservative therapy was scheduled and the patient recovered well. Jejunal diverticulitis is a rare cause of acute abdomen, however has to be considered as a differential diagnosis to more common entities. It usually stays localized, while in our case the inflammation ascended to the duodenum. CT is the modality of choice to diagnose and rule out potentially life threatening complications. PMID:25302248

  18. Mechanical analysis of the ring opening test applied to human ascending aortas.

    PubMed

    García-Herrera, Claudio M; Bustos, Claudio A; Celentano, Diego J; Ortega, Roberto

    2016-12-01

    This work presents experiments, modelling and numerical simulation aimed at describing the mechanical response of human ascending aortas in the ring opening test. The objective is to quantify, from the opening angles measured in the test, the residual stress distribution along the artery wall and, afterwards, how this stress pattern changes when the artery is subjected to standard physiological pressures. The cases studied correspond to four groups including both healthy and pathological arteries. The tissues are characterized via tensile test measurements that enable to derive the material parameters of two constitutive models adopted in the present analysis. Overall, the numerical results obtained for all groups were found to be a useful data that allow to estimate the residual stress and their influence on the vessels under normal and hypertension physiological conditions.

  19. Mathemimetics II. Demonstratio Mirabilis of FLT by infinitely ascending cubical crystal growth

    NASA Astrophysics Data System (ADS)

    Trell, Erik

    2012-09-01

    Emulating Nature by observation and ground-up application of its patterns, structures and processes is a classical scientific practice which under the designation of Biomimetics has now been brought to the Nanotechnology scale where even highly complex systems can be realized by continuous or cyclically reiterated assembly of the respective self-similar eigen-elements, modules and algorithms right from their infinitesimal origin. This is actually quite akin to the genuine mathematical art and can find valuable renewed use as here exemplified by the tentatively original Demonstratio Mirabilis of FLT (Fermat's Last Theorem, or, in that case, Triumph) by infinitely ascending sheet-wise cubical crystal growth leading to the binomial `magic triangle' of his close fellow Blaise Pascal.

  20. A behavioral analysis of complete unilateral section of the pyramidal tract at the medullary level in Macaca mulatta.

    PubMed

    Schwartzman, R J

    1978-09-01

    Ten Macaca mulatta monkeys were operantly conditioned to perform three motor paradigms designed to evaluate single and combination finger movements. Eight of these monkeys were retested after left medullary pyramidotomy; 2 monkeys underwent left medullary pyramidotomy prior to conditioning. All animals were tested for three years after operation. Monkeys with a completely sectioned medullary pyramid could, with time, perform difficult motor paradigms that required: (1) both individual and combination finger movements; (2) proximal upper extremity motor control; (3) thumb and index finger pincer grasp; and (4) the ability to preprogram and then execute a precision hand movement. The greater the extent of pyramidal tract destruction, the longer the time necessary for recovery of both discrete finger movement and pincer grasp, the greater the effort needed to attain recovery of hand function, and the weaker the affected musculature. The 2 animals in which pyramidotomy of at least 70% of the tract preceded efforts at operant conditioning learned and performed difficult motor paradigms. In all animals, neurological examination revealed that the most enduring and functionally most important deficit that interferes with hand function following pyramidotomy is loss of contactual hand orienting responses and failure of reflex sensorimotor adjustments.

  1. Decreased adrenal medullary tyrosine hydroxylase mRNA in DMBA (7,12-dimethylbenz(a)anthracene)-induced mammary carcinoma

    SciTech Connect

    Bunce, O.R.; Badary, O.A.; Abou El-Ela, S.; Hartle, D.K. )

    1991-03-15

    Adrenal cortical hormones suppress initiation and promotion of DMBA-induced mammary tumorigenesis. The authors found a positive correlation between presence of DMBA-induced adrenal cortical necrosis and mammary tumor incidence. Because they find adrenal medullary as well as cortical lesions in tumor bearing (TB) DMBA-treated rats, they evaluated medullary function by quantitating hybridized cDNA- TH-S{sup 35} with in situ TH-mRNA u sing computer assisted quantitative autoradiographic technique. Virgin female Sprague-Dawley rats were given a 10 mg i.g. dose of DMBA. Three wks later, rats were placed on 20% polyunsaturated (PUFA) fat diets containing omega-6 and omega-3 fatty acids. All were killed 15 wks post-DMBA. TH-mRNA levels in adrenal medullae of TB animals were decreased compared to non-TB rats. Histopathology indicated a high incidence of medullary necrosis in TB rats, whereas, adrenal necrosis did not occur in non-TB animals. Adrenal necrosis correlated positively with tumor burden, but no correlation was found between incidence of adrenal lesions and type of PUFA in the diet. The authors suggest that DMBA adrenal necrosis may reduce TH-mRNA in the medulla, compromise its catecholamine synthetic capability, and thereby contribute to the overall metabolic stress condition of TB rats.

  2. Social defeat stress induces hyperthermia through activation of thermoregulatory sympathetic premotor neurons in the medullary raphe region.

    PubMed

    Lkhagvasuren, Battuvshin; Nakamura, Yoshiko; Oka, Takakazu; Sudo, Nobuyuki; Nakamura, Kazuhiro

    2011-11-01

    Psychological stress-induced hyperthermia is a fundamental autonomic response in mammals. However, the central circuitry underlying this stress response is poorly understood. Here, we sought to identify sympathetic premotor neurons that mediate a hyperthermic response to social defeat stress, a psychological stress model. Intruder rats that were defeated by a dominant resident conspecific exhibited a rapid increase in abdominal temperature by up to 2.0  °C. In these defeated rats, we found that expression of Fos, a marker of neuronal activation, was increased in the rostral medullary raphe region centered in the rostral raphe pallidus and adjacent raphe magnus nuclei. In this region, Fos expression was observed in a large population of neurons expressing vesicular glutamate transporter 3 (VGLUT3), which are known as sympathetic premotor neurons controlling non-shivering thermogenesis in brown adipose tissue (BAT) and thermoregulatory constriction of skin blood vessels, and also in a small population of tryptophan hydroxylase-positive serotonergic neurons. Intraperitoneal injection of diazepam, an anxiolytic agent, but not indomethacin, an antipyretic, significantly reduced both the stress-induced hyperthermia and Fos expression in these medullary raphe neuronal populations. Systemic blockade of β3 -adrenoreceptors, which are abundantly expressed in BAT, also attenuated the stress-induced hyperthermia. These results suggest that psychological stress signals activate VGLUT3-expressing medullary raphe sympathetic premotor neurons, which then drive hyperthermic effector responses including BAT thermogenesis through β(3) -adrenoreceptors.

  3. Ultrasonic Inspection Of Thick Sections

    NASA Technical Reports Server (NTRS)

    Friant, C. L.; Djordjevic, B. B.; O'Keefe, C. V.; Ferrell, W.; Klutz, T.

    1993-01-01

    Ultrasonics used to inspect large, relatively thick vessels for hidden defects. Report based on experiments in through-the-thickness transmission of ultrasonic waves in both steel and filament-wound composite cases of solid-fuel rocket motors.

  4. How thick is the lithosphere?

    PubMed

    Kanamori, H; Press, F

    1970-04-25

    A rapid decrease in shear velocity in the suboceanic mantle is used to infer the thickness of the lithosphere. It is proposed that new and highly precise group velocity data constrain the solutions and imply a thickness near 70 km.

  5. Effects of midbrain and medullary stimulation on spinomesencephalic tract cells in the cat.

    PubMed

    Yezierski, R P

    1990-02-01

    1. The effects of electrical stimulation at different rostrocaudal levels of the midbrain, and at sites in the rostral medulla ipsilateral and contralateral to spinal recording sites, were evaluated against the responses of 46 cells belonging to the cat spinomesencephalic tract (SMT). 2. Inhibitory and/or excitatory effects of brain stem stimulation were observed on SMT cells that responded best (26 cells) or exclusively (12 cells) to noxious mechanical or thermal stimuli, as well as on 7 cells responding only to tap and/or stimulation of deep tissues. Recording sites for 32 cells were located in laminae V-VIII (27 cells) and laminae I-III (5 cells). 3. Midbrain stimulation sites were located in the superior colliculus, central gray (CG), red nucleus, and the midbrain reticular formation. Both inhibitory-only and excitatory-only effects were observed, although the most common effect of midbrain stimulation was excitation followed by inhibition (mixed effects). The effects of stimulation at different midbrain levels were determined for each cell. Stimulation in the caudal, middle, or rostral midbrain was often found to exert different effects on the same SMT cell. 4. Stimulation in the rostral medulla at sites located in nucleus raphe magnus (NRM), nucleus reticularis gigantocellularis, and nucleus reticularis magnocellularis produced the same complement of effects observed with midbrain stimulation. Excitation followed by inhibition was the most common effect observed. 5. Stimulus intensities required to produce excitatory or inhibitory effects from midbrain were 114 +/- 85 (SD) microA and 210 +/- 91 microA, respectively. Stimulus currents required to produce excitatory or inhibitory effects from medullary stimulation sites were 124 +/- 56 microA and 70 +/- 60 microA, respectively. The mean currents required to produce mixed effects were 221 +/- 120 microA (midbrain) and 127 +/- 71 microA (medulla). Increasing the stimulus intensity used to evaluate brain stem

  6. Long-term correlations in the spike trains of medullary sympathetic neurons.

    PubMed

    Lewis, C D; Gebber, G L; Larsen, P D; Barman, S M

    2001-04-01

    Fano factor analysis was used to characterize the spike trains of single medullary neurons with sympathetic nerve-related activity in cats that were decerebrate or anesthetized with Dial-urethan or urethan. For this purpose, values (Fano factor) of the variance of the number of extracellularly recorded spikes divided by the mean number of spikes were calculated for window sizes of systematically varied length. For window sizes < or =10 ms, the Fano factor was close to one, as expected for a Bernoulli process with a low probability of success. The Fano factor dipped below one as the window size approached the shortest interspike interval (ISI) and reached its nadir at window sizes near the modal ISI. The extent of the dip reflected the shape (skewness) of the ISI histogram with the dip being smallest for the most asymmetric distributions. Most importantly, for a wide range of window sizes exceeding the modal ISI, the Fano factor curve took the form of a power law function. This was the case independent of the component (cardiac related, 10 Hz, or 2--6 Hz) of inferior cardiac sympathetic nerve discharge to which unit activity was correlated or the medullary region (lateral tegmental field, raphe, caudal and rostral ventrolateral medulla) in which the neuron was located. The power law relationship in the Fano factor curves was eliminated by randomly shuffling the ISIs even though the distribution of the intervals was unchanged. Thus the power law relationship arose from long-term correlations among ISIs that were disrupted by shuffling the data. The presence of long-term correlations across different time scales reflects the property of statistical self-similarity that is characteristic of fractal processes. In most cases, we found that mean ISI and variance for individual spike trains increased as a function of the number of intervals counted. This can be attributed to the clustering of long and short ISIs, which also is an inherent property of fractal time series

  7. Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for ASCENDS O2 Column Measurements

    NASA Technical Reports Server (NTRS)

    Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.; Harrison, F. Wallace; Obland, Michael D.; Meadows, Byron

    2015-01-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity- Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation, where it is shown useful for making tree canopy measurements.

  8. Atmospheric Airborne Pressure Measurements Using the Oxygen A Band for the ASCENDS Mission

    NASA Technical Reports Server (NTRS)

    Riris, Haris; Rodriguez, Mike; Stephen, Mark; Hasselbrack, William; Allan, Graham; Mao, Jiamping,; Kawa, Stephan R.; Weaver, Clark J.

    2011-01-01

    We report on airborne atmospheric pressure measurements using new fiber-based laser technology and the oxygen A-band at 765 nm. Remote measurements of atmospheric temperature and pressure are required for a number of NASA Earth science missions and specifically for the Active Sensing of CO2 Emissions Over Nights, Days, and Seasons (ASCENDS) mission. Accurate measurements of tropospheric CO2 on a global scale are very important in order to better understand its sources and sinks and to improve predictions on any future climate change. The ultimate goal of a CO2 remote sensing mission, such as ASCENDS, is to derive the CO2 concentration in the atmosphere in terms of mole fraction in unit of parts-per-million (ppmv) with regard to dry air. Therefore, both CO2 and the dry air number of molecules in the atmosphere are needed in deriving this quantity. O2 is a stable molecule and uniformly mixed in the atmosphere. Measuring the O2 absorption in the atmosphere can thus be used to infer the dry air number of molecules and then used to calculate CO2 concentration. With the knowledge of atmospheric water vapor, we can then estimate the total surface pressure needed for CO2 retrievals. Our work, funded by the ESTO IIP program, uses fiber optic technology and non-linear optics to generate 765 nm laser radiation coincident with the Oxygen A-band. Our pulsed, time gated technique uses several on- and off-line wavelengths tuned to the O2 absorption line. The choice of wavelengths allows us to measure the pressure by using two adjacent O2 absorptions in the Oxygen A-band. Our retrieval algorithm fits the O2 lineshapes and derives the pressure. Our measurements compare favorably with a local weather monitor mounted outside our laboratory and a local weather station.

  9. Atmospheric Airborne Pressure Measurements Using the Oxygen A Band for the ASCENDS Mission

    NASA Technical Reports Server (NTRS)

    Riris, Haris; Rodriguez, Mike; Stephen, Mark; Hasselbrack, William; Allan, Graham; Mao, Jianping; Kawa, Stephen R.; Weaver, Clark J.

    2010-01-01

    We report on airborne atmospheric pressure measurements using new fiber-based laser technology and the oxygen A-band at 765 nm. Remote measurements of atmospheric temperature and pressure are required for a number of NASA Earth science missions and specifically for the Active Sensing of CO2 Emissions Over Nights, Days, and Seasons (ASCENDS) mission. Accurate measurements of tropospheric CO2 on a global scale are very important in order to better understand its sources and sinks and to improve predictions on any future climate change. The ultimate goal of a CO2 remote sensing mission, such as ASCENDS, is to derive the CO2 concentration in the atmosphere in terms of mole fraction in unit of parts-per-million (ppmv) with regard to dry air. Therefore, both CO2 and the dry air number of molecules in the atmosphere are needed in deriving this quantity. O2 is a stable molecule and uniformly mixed in the atmosphere. Measuring the O2 absorption in the atmosphere can thus be used to infer the dry air number of molecules and then used to calculate CO2 concentration. With the knowledge of atmospheric water vapor, we can then estimate the total surface pressure needed for CO2 retrievals. Our work, funded by the ESTO IIP program, uses fiber optic technology and non-linear optics to generate 765 nm laser radiation coincident with the Oxygen A-band. Our pulsed, time gated technique uses several on- and off-line wavelengths tuned to the O2 absorption line. The choice of wavelengths allows us to measure the pressure by using two adjacent O2 absorptions in the Oxygen A-band. Our retrieval algorithm fits the O2 lineshapes and derives the pressure. Our measurements compare favorably with a local weather monitor mounted outside our laboratory and a local weather station.

  10. The role of oxygen-increased respirator in humans ascending to high altitude

    PubMed Central

    2012-01-01

    Background Acute mountain sickness (AMS) is common for people who live in low altitude areas ascending to the high altitude. Many instruments have been developed to treat mild cases of AMS. However, long-lasting and portable anti-hypoxia equipment for individual is not yet available. Methods Oxygen-increased respirator (OIR) has been designed to reduce the risk of acute mountain sickness in acute exposure to low air pressure. It can increase the density of oxygen by increasing total atmospheric pressure in a mask. Male subjects were screened, and eighty-eight were qualified to perform the experiments. The subjects were divided into 5 groups and were involved in some of the tests at 4 different altitudes (Group 1, 2: 3700 m; Group 3,4,5: 4000 m, 4700 m, 5380 m) with and without OIR. These tests include heart rate, saturation of peripheral oxygen (SpO2), malondialdehyde (MDA), superoxide dismutase (SOD), blood lactate (BLA) and PWC (physical work capacity) -170. Results The results showed that higher SpO2, lower heart rate (except during exercise) and better recovery of heart rate were observed from all the subjects ’with OIR’ compared with ’without OIR’ (P<0.05). Moreover, compared with ’without OIR’, subjects ’with OIR’ in Group 1 had lower concentrations of MDA and BLA, and a higher concentration of SOD (P<0.05), while subjects ’with OIR’ in Group 2 showed better physical capacity (measured by the PWC-170) (P<0.05). The additional experiment conducted in a hypobaric chamber (simulating 4,000 m) showed that the partial pressure of oxygen in blood and arterial oxygen saturation were higher ’with OIR’ than ’without OIR’ (P<0.05). Conclusions We suggested that OIR may play a useful role in protecting people ascending to high altitude before acclimatization. PMID:22898206

  11. Turning a Negative into a Positive: Ascending GABAergic Control of Cortical Activation and Arousal

    PubMed Central

    Brown, Ritchie E.; McKenna, James T.

    2015-01-01

    Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain. Recent technological advances have illuminated the role of GABAergic neurons in control of cortical arousal and sleep. Sleep-promoting GABAergic neurons in the preoptic hypothalamus are well-known. Less well-appreciated are GABAergic projection neurons in the brainstem, midbrain, hypothalamus, and basal forebrain, which paradoxically promote arousal and fast electroencephalographic (EEG) rhythms. Thus, GABA is not purely a sleep-promoting neurotransmitter. GABAergic projection neurons in the brainstem nucleus incertus and ventral tegmental nucleus of Gudden promote theta (4–8 Hz) rhythms. Ventral tegmental area GABAergic neurons, neighboring midbrain dopamine neurons, project to the frontal cortex and nucleus accumbens. They discharge faster during cortical arousal and regulate reward. Thalamic reticular nucleus GABAergic neurons initiate sleep spindles in non-REM sleep. In addition, however, during wakefulness, they tonically regulate the activity of thalamocortical neurons. Other GABAergic inputs to the thalamus arising in the globus pallidus pars interna, substantia nigra pars reticulata, zona incerta, and basal forebrain regulate motor activity, arousal, attention, and sensory transmission. Several subpopulations of cortically projecting GABAergic neurons in the basal forebrain project to the thalamus and neocortex and preferentially promote cortical gamma-band (30–80 Hz) activity and wakefulness. Unlike sleep-active GABAergic neurons, these ascending GABAergic neurons are fast-firing neurons which disinhibit and synchronize the activity of their forebrain targets, promoting the fast EEG rhythms typical of conscious states. They are prominent targets of GABAergic hypnotic agents. Understanding the properties of ascending GABAergic neurons may lead to novel treatments for diseases involving disorders of cortical activation and wakefulness. PMID:26124745

  12. Blow flies (Diptera: Calliphoridae) survive burial: Evidence of ascending vertical dispersal.

    PubMed

    Balme, G R; Denning, S S; Cammack, J A; Watson, D W

    2012-03-10

    This study was undertaken to determine if immature blow flies could complete development following burial and emerge from the soil as adults. Two species of blow flies, Cochliomyia macellaria and Protophormia terraenovae, were placed at three depths and at three different life stages, in a simulated burial to evaluate the impact of soil on ascending vertical dispersal and fly survival. In soil columns, immature stages of each species were covered with 5, 25 and 50cm of soil. Emerging adult flies of both species reached the surface from all depths at all three immature stages (2nd instar, 3rd instar and pupae). At the 50-cm depth, flies were least successful in reaching the surface when buried as pupae and most successful as late 3rd instar larvae (prepupae). Collectively, more adult flies emerged from the soil if buried as 3rd instars (79.6%) than either 2nd instars or pupae (59.6% and 59.3%, respectively (F(2,159)=14.76, P<0.0001)). Similarly, at shallow burial depths of 5 and 25cm, 75.6% and 70.4% of the adults successfully reached the surface, compared with 52.6% at the 50-cm depth (F(2,159)=15.95, P<0.0001). Second instars demonstrated ascending vertical dispersal behaviours in the soil column by pupating closer to the surface. Nearly half (46.6%) of the C. macellaria 2nd instars buried in 25cm of soil pupated nearer to the surface. Similarly, 45.4% of the P. terraenovae 2nd instars pupated nearer to the surface. When buried at 50cm, approximately 25% of 2nd instars of both species pupated nearer to the surface. When 3rd instars of C. macellaria and P. terraenovae were buried at 120cm, 40% and 4.3% of the adults, respectively, successfully reached the soil surface.

  13. Older adults employ alternative strategies to operate within their maximum capabilities when ascending stairs.

    PubMed

    Reeves, N D; Spanjaard, M; Mohagheghi, A A; Baltzopoulos, V; Maganaris, C N

    2009-04-01

    Older people may operate much closer to their maximum capabilities than young adults when ascending stairs due to their lower maximum musculoskeletal capabilities. The purpose of this study was to establish the joint moment and range of motion demands of stair ascent relative to maximum capabilities in elderly and young adults. Fifteen elderly (mean age 75 years) and 17 young adult (mean age 25 years) participants ascended a purpose-built 4-step staircase with force platforms embedded into the steps and kinematic data was acquired using motion capture. Maximum musculoskeletal capabilities were assessed using a dynamometer. This study showed for the first time that stair ascent approaches the joint moment limits at the ankle in both young and older participants ( approximately 90%). One of the most important and novel findings of this study was that elderly people were only capable of meeting the high demands by adopting a number of alternative strategies not observed in young adults: (i) applying the joint moments differently than young adults across the knee and ankle, (ii) translocating energy from the knee to the ankle, thereby enhancing the ankle joint moment upon maximum demand and (iii) by enabling the plantarflexors to act over a more favourable portion of the moment-angle relation upon maximum ankle joint moment demand. The elderly displayed a more cautious strategy to optimize positional stability during stair ascent, by maintaining a smaller separation between the centre of mass and centre of pressure in the frontal plane. It seems that elderly people may meet the demands of unaided stair ascent by adopting a number of alternative strategies to compensate for their reduced musculoskeletal capabilities.

  14. Advanced intensity-modulation continuous-wave lidar techniques for ASCENDS CO2 column measurements

    NASA Astrophysics Data System (ADS)

    Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.; Harrison, F. W.; Obland, Michael D.; Meadows, Byron

    2015-10-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity- Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation, where it is shown useful for making tree canopy measurements.

  15. Waterway Ice Thickness Measurements

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The ship on the opposite page is a U. S. Steel Corporation tanker cruising through the ice-covered waters of the Great Lakes in the dead of winter. The ship's crew is able to navigate safely by plotting courses through open water or thin ice, a technique made possible by a multi-agency technology demonstration program in which NASA is a leading participant. Traditionally, the Great Lakes-St. Lawrence Seaway System is closed to shipping for more than three months of winter season because of ice blockage, particularly fluctuations in the thickness and location of ice cover due to storms, wind, currents and variable temperatures. Shippers have long sought a system of navigation that would allow year-round operation on the Lakes and produce enormous economic and fuel conservation benefits. Interrupted operations require that industrial firms stockpile materials to carry them through the impassable months, which is costly. Alternatively, they must haul cargos by more expensive overland transportation. Studies estimate the economic benefits of year-round Great Lakes shipping in the hundreds of millions of dollars annually and fuel consumption savings in the tens of millions of gallons. Under Project Icewarn, NASA, the U.S. Coast Guard and the National Oceanic Atmospheric Administration collaborated in development and demonstration of a system that permits safe year-round operations. It employs airborne radars, satellite communications relay and facsimile transmission to provide shippers and ships' masters up-to-date ice charts. Lewis Research Center contributed an accurate methods of measuring ice thickness by means of a special "short-pulse" type of radar. In a three-year demonstration program, Coast Guard aircraft equipped with Side-Looking Airborne Radar (SLAR) flew over the Great Lakes three or four times a week. The SLAR, which can penetrate clouds, provided large area readings of the type and distribution of ice cover. The information was supplemented by short

  16. Kidney-Tonifying Recipe Can Repair Alterations in Adrenal Medullary Chromaffin Cells in Asthmatic Rats

    PubMed Central

    Hu, Cheng-Ping; Zou, Jun-Tao; Zou, Ye-Qiang; Li, Xiao-Zhao; Feng, Jun-Tao

    2012-01-01

    Traditional Chinese medicine suggests that renal deficiency is a causative factor of asthma, and tonifying kidney drugs are believed to be an appropriate and beneficial treatment. The adrenal medullary chromaffin cells (AMCC) transition to the neuronal phenotype is known to occur in asthma, as evidenced by degranulation of chromaffin granules, decline of epinephrine (EPI) and phenylethanolamine-n-methyl transferase (PNMT), and obvious alterations in cellular architecture. In this study, rats were sensitized and challenged with ovalbumin, then treated with Kidney-Tonifying Recipe (KTR) to evaluate the therapeutic effect. Tissues were evaluated for changes in pathology and EPI, PNMT, and peripherin expression. Degranulation of chromaffin granules and appearance of neurite-like process were found in AMCC from asthmatic rats, and these changes were corrected by KTR treatment. EPI and PNMT expressions were decreased in asthmatic rats and increased by KTR treatment. Peripherin expression was increased in asthmatic rats and decreased in the KTR-treated group. Morphological changes and decreases in EPI were observed when cultured AMCC were exposed to sera from asthmatic rats in vitro, and these changes were attenuated with the addition of sera from KRT-treated rats. These results suggest that the Kidney-Tonifying Recipe is capable of repairing asthma-associated alterations in endocrine function and the ultrastructure of AMCC. PMID:22474509

  17. Familial clustering of medullary sponge kidney is autosomal dominant with reduced penetrance and variable expressivity.

    PubMed

    Fabris, Antonia; Lupo, Antonio; Ferraro, Pietro M; Anglani, Franca; Pei, York; Danza, Francesco M; Gambaro, Giovanni

    2013-02-01

    Medullary sponge kidney (MSK) is a renal malformation typically associated with nephrocalcinosis and recurrent calcium nephrolithiasis. Approximately 12% of recurrent stone formers have MSK, which is generally considered a sporadic disorder. Since its discovery, three pedigrees have been described in which an apparently autosomal dominant inheritance was suggested. Here, family members of 50 patients with MSK were systematically investigated by means of interviews, renal imaging, and biochemical studies in an effort to establish whether MSK is an inheritable disorder. Twenty-seven MSK probands had 59 first- and second-degree relatives of both genders with MSK in all generations. There were progressively lower mean levels of serum calcium, urinary sodium, pH, and volume, combined with higher serum phosphate and potassium from probands to relatives with bilateral, to those with unilateral, and to those unaffected by MSK. This suggests that most affected relatives have a milder form of MSK than the probands, which would explain why they had not been so diagnosed. Thus, our study provides strong evidence that familial clustering of MSK is common, and has an autosomal dominant inheritance, a reduced penetrance, and variable expressivity.

  18. Expression of sex steroid hormone receptors in C cell hyperplasia and medullary thyroid carcinoma.

    PubMed

    Bléchet, Claire; Lecomte, Pierre; De Calan, Loïc; Beutter, Patrice; Guyétant, Serge

    2007-04-01

    Previous studies have shown that C cells are twice as numerous in male than in female thyroids and that C cell hyperplasia (CCH) is much more frequent in men. These findings suggest regulation involving sex steroid hormones through the expression of sex steroid hormone receptors on C cells. To investigate this hypothesis, we performed an immunohistochemical study of estrogen receptors alpha (ER alpha) and beta (ER beta), progesterone receptors (PR), and androgen receptors (AR) on specimens from a series of 40 patients operated on for a medullary thyroid carcinoma (MTC; n=28; female 18, male 10) and/or CCH (n=19; female 6, male 13). ER beta was the only receptor to be consistently expressed in CCH (100%) and MTC (96.5%), whereas ER alpha was never expressed. PR and AR were rarely expressed in MTC (7 and 14%, respectively). AR was expressed in half the CCH cases (53%), with a trend to male predominance (61% in men vs 33% in women). Our study is the first to describe ER beta expression in CCH. In addition, our findings suggest that CCH, and possibly MTC, might be influenced by sex steroid hormones, namely, estrogens and androgens, through the expression of ER beta and AR on C cells.

  19. Targeted DNA Sequencing Detects Mutations Related to Susceptibility among Familial Non-medullary Thyroid Cancer

    PubMed Central

    Yu, Yang; Dong, Li; Li, Dapeng; Chuai, Shaokun; Wu, Zhigang; Zheng, Xiangqian; Cheng, Yanan; Han, Lei; Yu, Jinpu; Gao, Ming

    2015-01-01

    Some studies have demonstrated that familial non-medullary thyroid cancer (FNMTC) has a more aggressive clinical behavior compared to sporadic NMTC (SNMTC). However, FNMTC is difficult to differentiate from SNMTC by the morphology and immunohistochemistry. Although genes responsible for FNMTC were unclear, screening for rare germline mutations on known important tumor suppressor genes might offer more insights on predicting susceptibility to FNMTC. Here, a customized panel was designed to capture all exons of 31 cancer susceptive genes possibly related to FNMTC. Using next-generation sequencing we performed deep sequencing to achieve 500× coverage of the targeted regions. At the end 45 variants were identified in 29 of 47 familial patients and 6 of 16 sporadic patients. Notably, several germline mutations were found matching between paired FNMTC patients from the same family, including APC L292F and A2778S, BRAF D22N, MSH6 G355S and A36V, MSH2 L719F, MEN1 G508D, BRCA1 SS955S, BRCA2 G2508S, and a GNAS inframe insertion. We demonstrated a novel approach to help diagnose and elucidate the genetic cause of the FNMTC patients, and assess whether their family members are exposed to a higher genetic risk. The findings would also provide insights on monitoring the potential second cancers for thyroid cancer patients. PMID:26530882

  20. The adrenal medullary transplant operation for Parkinson's disease: clinical observations in five patients.

    PubMed

    Penn, R D; Goetz, C G; Tanner, C M; Klawans, H L; Shannon, K M; Comella, C L; Witt, T R

    1988-06-01

    The recent report by Madrazo and coworkers on the successful treatment of Parkinson's disease using adrenal medullary tissue transplanted to the caudate nucleus has aroused international interest in the procedure. The present article reports our initial experiences with the operation in five patients and discusses the postoperative effects of the procedure, the protocol used to monitor motor performance, and the need for cooperation with the two registries that have been created to follow morbidity, mortality, and efficacy. We intend to alert the neurosurgeon to important side effects, but not to assess the long term efficacy of the procedure. Postoperatively, a number of transient effects were seen in our patients, the most striking being somnolence, delusions, and lack of significant pain in spite of a large abdominal incision. The only complications have been respiratory. After the early postoperative period, gradual improvement of on-off times and Schwab-England disability scores was seen over 20 weeks. Long term cooperative studies are needed to demonstrate the efficacy of this procedure. neurosurgeons doing transplant operations are urged to join the registries so that uniform information can be collected.

  1. Adrenal medullary autograft transplantation into the striatum of patients with Parkinson's disease.

    PubMed

    Kelly, P J; Ahlskog, J E; van Heerden, J A; Carmichael, S W; Stoddard, S L; Bell, G N

    1989-03-01

    In eight patients with advanced Parkinson's disease, we performed autograft transplantation of adrenal medulla to the head of the caudate nucleus. Our technique was similar to that developed by Madrazo and co-workers in Mexico City. No major perioperative complications occurred except for somnolence in one patient for 8 days postoperatively. The follow-up period has been at least 6 months in seven of the patients, and only limited benefit has been apparent. The early morning Parkinson examination score in the "off" (unmedicated) state was significantly improved in one patient and slightly better in the other six. Diary card entries suggested a mild trend toward improvement (not statistically significant). Four of the seven patients were taking less levodopa 6 months after the operation than they had been preoperatively; three of five patients were no longer taking dopamine agonists postoperatively. We cannot exclude a placebo effect contributing to any of this improvement. A reduction in medication-induced dyskinesia was also noted, but this result may have been due to adjustments in doses or a slightly less potent effect of medication (or both factors). In summary, we have not yet been able to replicate the dramatic success reported for adrenal medullary transplantation by Madrazo's group, although our patients may have experienced mild to moderate improvement. We continue to maintain follow-up surveillance of these patients.

  2. Medullary thyroid carcinoma: a 30-year experience at one institution in Korea

    PubMed Central

    Lee, Cho Rok; Lee, Sohee; Son, Haiyoung; Ban, Eunjeong; Kang, Sang-Wook; Lee, Jandee; Nam, Kee-Hyun; Chung, Woong Youn; Park, Cheong Soo

    2016-01-01

    Purpose The objective of this study was to review the clinical outcome and prognosis of patients with sporadic and hereditary medullary thyroid cancer (MTC) who were treated at a single tertiary hospital in Korea. Methods We retrospectively reviewed the case files of 85 patients treated from August 1982 to February 2012. Results In all, 65 patients (76.5%) had sporadic MTC and 20 patients (23.5%) had hereditary MTC. Patients in the sporadic group were older than in the hereditary group (P < 0.001). However, the hereditary group had more tumor multiplicity (P < 0.001) and bilaterality (P < 0.001). Neither survival rate was significantly different between the sporadic and hereditary groups (P = 0.775 and P = 0.866). By multivariate analysis, distant metastasis was a significant prognostic factor for overall and progression-free survival. Conclusion In general, patients with MTC have favorable outcomes. Distant metastasis appears to be the strongest predictor of overall and progression-free survival. PMID:27904849

  3. Effect of MPTP on primate chromaffin cells in vitro: relevance for adrenal medullary cell transplantation.

    PubMed

    Notter, M F; Kaniuki, M; Felten, S Y; Hansen, J T; Gash, D M

    1991-01-01

    Primate adrenal medullary cells were exposed to l-methyl-4-phenyl-l,2,3,6-tetrahydropyridine (MPTP) in vitro to examine the effect of this neurotoxic agent on chromaffin cells. Chromaffin cells from monkey and humans were cultured in the presence of 100 ng/ml nerve growth factor for 1 week and then exposed to 150 μM MPTP or its active metabolite methylpyridinium ion (MPP+) for an additional week. Cells which had extended neurites in the presence of NGF showed no morphological effect in response to MPTP or MPP+ at the light microscopic level. However, there was a significant loss in catecholamines as seen by histofluorescence and high performance liquid chromotography (HPLC). Electron microscopy revealed a depletion in dense-core vesicles in chromaffin cells after chronic exposure to MPTP while the mitochondria appeared similar to those observed in control cells. Replacement of MPTP medium with standard medium stimulated restoration of catecholamine histofluorescence after 7 days. An acute 15 min pretreatment of chromaffin cells with MPTP or MPP+ induced secretion of catecholamines over a 1 h pulse, with MPP+ producing the maximum and more rapid secretion as determined by HPLC. These data indicate that MPTP induces a dramatic loss in catecholamines in primate chromaffin cells in vitro after both acute and chronic exposures; however, removal of the toxic agent permits restoration of catecholamines without permanent effect on the integrity of these cells.

  4. Type 2 Iodothyronine Deiodinase Is Highly Expressed in Medullary Thyroid Carcinoma

    PubMed Central

    Meyer, Erika L Souza; Goemann, Iuri M; Dora, José Miguel; Maia, Ana Luiza

    2008-01-01

    Summary Type II deiodinase (D2) plays a critical role in controlling intracellular T3 concentration and early studies indicated a follicular but not a parafollicular C-cell origin of D2 activity in the thyroid gland. Here, we show that D2 is highly expressed in human medullary thyroid carcinoma (MTC), a tumour that arises from the C-cells. D2 transcripts were detected in all MTC samples obtained from 12 unselected MTC patients and the levels of D2 activity were comparable to those found in surrounding normal follicular tissue (0.41±0.10 vs 0.43±0.41 fmol.min.mg.protein, P=0.91). Additional analysis in the TT cells, a human MTC cell line, demonstrated that the D2 expression is down regulated by thyroid hormones and enhanced by cAMP analogs and dexamethasone. The thyroid hormone receptor α1 and β isoforms were also detected in all MTC samples and in TT cells, thus suggesting a potential role of T3 locally produced by D2 in this neoplastic tissue. PMID:18514391

  5. Lack of effectiveness of laser therapy applied to the nerve course and the correspondent medullary roots

    PubMed Central

    Sousa, Fausto Fernandes de Almeida; Ribeiro, Thaís Lopes; Fazan, Valéria Paula Sassoli; Barbieri, Claudio Henrique

    2013-01-01

    OBJECTIVE: To investigate the influence of low intensity laser irradiation on the regeneration of the fibular nerve of rats after crush injury. METHODS: Twenty-five rats were used, divided into three groups: 1) intact nerve, no treatment; 2) crushed nerve, no treatment; 3) crush injury, laser irradiation applied on the medullary region corresponding to the roots of the sciatic nerve and subsequently on the course of the damaged nerve. Laser irradiation was carried out for 14 consecutive days. RESULTS: Animals were evaluated by functional gait analysis with the peroneal functional index and by histomorphometric analysis using the total number of myelinated nerve fibers and their density, total number of Schwann cells, total number of blood vessels and the occupied area, minimum diameter of the fiber diameter and G-quotient. CONCLUSION: According to the statistical analysis there was no significant difference among groups and the authors conclude that low intensity laser irradiation has little or no influence on nerve regeneration and functional recovery. Laboratory investigation. PMID:24453650

  6. The molecular biology of medullary thyroid carcinoma: A model for cancer development and progression

    SciTech Connect

    Nelkin, B.D.; de Bustros, A.C.; Mabry, M.; Baylin, S.B. )

    1989-06-02

    Medullary thyroid carcinoma (MTC) is an important human cancer for the study of molecular abnormalities that underlie initiation of neoplasia and subsequent cellular changes during tumor progression. Thus tumor can occur in different inherited forms, each mediated by autosomal dominant genetic events. Germline abnormalities on chromosome 10 are linked to at least one type of genetic MTC, multiple endocrine neoplasia type II. These studies of chromosome 10 in DNA from MTC tumors failed to detect frequent loss of polymorphic DNA markers, suggesting that the genetic mechanisms involved in MTC development may be different from those for other inherited cancers such as retinoblastoma. During tumor progression of MTC, abnormalities develop in expression of the mature phenotype of the endocrine cell from which the tumor arises. In cell culture, chemical modulation or gene insertion can lead to partial correction of these defects in differentiation capacity by activating cellular signaling processes. These studies offer opportunities to dissect the molecular events that regulate endocrine cell differentiation, to determine the precise abnormalities that may underlie the initiation and tumor progression events in MTC and related cancers, and, thereby, to identify new targets for therapeutic intervention.

  7. Medullary serotonin defects and respiratory dysfunction in sudden infant death syndrome.

    PubMed

    Paterson, David S; Hilaire, Gerard; Weese-Mayer, Debra E

    2009-08-31

    Sudden infant death syndrome (SIDS) is defined as the sudden and unexpected death of an infant less than 12 months of age that occurs during sleep and remains unexplained after a complete autopsy, death scene investigation, and review of the clinical history. It is the leading cause of postneonatal mortality in the developed world. The cause of SIDS is unknown, but is postulated to involve impairment of brainstem-mediated homeostatic control. Extensive evidence from animal studies indicates that serotonin (5-HT) neurons in the medulla oblongata play a role in the regulation of multiple aspects of respiratory and autonomic function. A subset of SIDS infants have several abnormalities in medullary markers of 5-HT function and genetic polymorphisms impacting the 5-HT system, informing the hypothesis that SIDS results from a defect in 5-HT brainstem-mediated control of respiratory (and autonomic) regulation. Here we review the evidence from postmortem human studies and animal studies to support this hypothesis and discuss how the pathogenesis of SIDS is likely to originate in utero during fetal development.

  8. Molecular pathology of myelodysplastic syndromes: biology of medullary stromal and hematopoietic cells (review).

    PubMed

    Kitagawa, Masanobu; Kurata, Morito; Yamamoto, Kouhei; Abe, Shinya; Suzuki, Shiho; Umeda, Shigeaki

    2011-01-01

    Myelodysplastic syndromes (MDS) have been defined as a disease entity based on clinical features and morphological findings. Despite similarities in clinical manifestations, genetic abnormalities occurring in hematopoietic cells are heterogeneous among the syndromes. However, recent investigations have revealed that there are common biological events in the bone marrow of MDS cases. Most notably, excessive apoptosis of hematopoietic cells was observed to be induced by the bone marrow microenvironment. The apoptosis was mediated by paracrine as well as autocrine factors, suggesting that medullary stromal and hematopoietic cells play a role in the pathology of disease. Pro-inflammatory cytokines, such as TNFα, in the bone marrow microenvironment are predominantly paracrine mediators of apoptosis. Regarding autocrine stimulation mechanisms, it has recently been shown that the deregulation of ribosomal protein is capable of initiating a stress response in the hematopoietic cell through a p53-mediated signaling pathway. Thus, both the stromal cells of the bone marrow microenvironment and hematopoietic cells themselves possess a common and characteristic biology in this heterogeneous disease entity.

  9. Congenital difficulties with swallowing and breathing associated with maternal polyhydramnios: neurocristopathy or medullary infarction?

    PubMed

    Alvord, E C; Shaw, C M

    1989-10-01

    Two babies with congenital difficulties in swallowing and breathing are presented and contrasted. Both were associated with maternal polyhydramnios, but one was due to medullary infarction and the other to a malformation ("neurocristopathy"). In the former case, isolated tenth and twelfth cranial nerve palsies provided the clue as to the correct etiology, whereas the latter baby had dyscoordination of swallowing and breathing with sleep apnea ("Ondine's curse"). It is somewhat ironic that the case without a difficult delivery had the infarct, probably prenatal in onset, whereas the one with a difficult delivery had the congenital malformation. Neural crest cells are known to migrate widely and to develop greatly different functions, but the fact that their central associations of neural tube origin may also be affected has not previously been emphasized in the etiopathogenesis of the congenital malformation. A variety of syndromes with combinations of many defects may be seen in which too many or too few cells are formed, with more or less serious consequences especially for the respiratory and gastrointestinal systems.

  10. Dexamethasone increases aquaporin-2 protein expression in ex vivo inner medullary collecting duct suspensions

    PubMed Central

    Chen, Minguang; Cai, Hui; Klein, Janet D.; Laur, Oskar; Chen, Guangping

    2015-01-01

    Aquaporin-2 (AQP2) is the vasopressin-regulated water channel that controls renal water reabsorption and plays an important role in the maintenance of body water homeostasis. Excessive glucocorticoid as often seen in Cushing's syndrome causes water retention. However, whether and how glucocorticoid regulates AQP2 remains unclear. In this study, we examined the direct effect of dexamethasone on AQP2 protein expression and activity. Dexamethasone increased AQP2 protein abundance in rat inner medullary collecting duct (IMCD) suspensions. This was confirmed in HEK293 cells transfected with AQP2 cDNA. Cell surface protein biotinylation showed an increase of dexamethasone-induced cell membrane AQP2 expression and this effect was blocked by glucocorticoid receptor antagonist RU486. Functionally, dexamethasone treatment of oocytes injected with an AQP2 cRNA increased water transport activity as judged by cell rupture time in a hypo-osmotic solution (66 ± 13 s in dexamethasone vs. 101 ± 11 s in control, n = 15). We further found that dexamethasone treatment reduced AQP2 protein degradation, which could result in an increase of AQP2 protein. Interestingly, dexamethasone promoted cell membrane AQP2 moving to less buoyant lipid raft submicrodomains. Taken together, our data demonstrate that dexamethasone promotes AQP2 protein expression and increases water permeability mainly via inhibition of AQP2 protein degradation. The increase in AQP2 activity promotes water reabsorption, which may contribute to glucocorticoid-induced water retention and hypertension. PMID:26578982

  11. Protein expression levels in the medullary visceral zone of rats with subarachnoid hemorrhage.

    PubMed

    Sun, L H; Xing, L F; Zhang, G H; Pan, S Y

    2015-08-03

    We investigated protein expression in the medullary visceral zone (MVZ) of rats with multiple-organ dysfunction syndrome (MODS) caused by subarachnoid hemorrhage (SAH) to discuss the possible regulatory mechanism of the MVZ in the course of SAH-induced MODS. A SAH-induced MODS model was established in rats by injecting arterial blood into the Willis' circle. Protein expression in the MVZ was analyzed by immunohistochemistry assay. Protein expression in the MVZ peaked 24-36 h after SAH, and was significantly higher than in the control and sham operation groups. Organs at each time point exhibited inflammatory injuries to varying degrees after SAH, which reached a maximum at 24-36 h. Incidences of systemic inflammatory response syndrome and MODS were 100 and 71.67%, respectively, after SAH. There is a consistency between MVZ protein expression and inflammatory changes in each organ after SAH. This prompts the suggestion that the MVZ may be one of the direct regulative centers in SAH-induced MODS, and may be involved in the functional regulation of the surrounding organs after SAH.

  12. Medullary mediation of the laryngeal adductor reflex: A possible role in sudden infant death syndrome.

    PubMed

    Wang, Xiaolu; Guo, Ruichen; Zhao, Wenjing; Pilowsky, Paul M

    2016-06-01

    The laryngeal adductor reflex (LAR) is a laryngeal protective reflex. Vagal afferent polymodal sensory fibres that have cell bodies in the nodose ganglion, originate in the sub-glottal area of the larynx and upper trachea. These polymodal sensory fibres respond to mechanical or chemical stimuli. The central axons of these sensory vagal neurons terminate in the dorsolateral subnuclei of the tractus solitarius in the medulla oblongata. The LAR is a critical, reflex in the pathways that play a protective role in the process of ventilation, and the sychronisation of ventilation with other activities that are undertaken by the oropharyngeal systems including: eating, speaking and singing. Failure of the LAR to operate properly at any time after birth can lead to SIDS, pneumonia or death. Despite the critical nature of this reflex, very little is known about the central pathways and neurotransmitters involved in the management of the LAR and any disorders associated with its failure to act properly. Here, we review current knowledge concerning the medullary nuclei and neurochemicals involved in the LAR and propose a potential neural pathway that may facilitate future SIDS research.

  13. Involvement of catecholaminergic medullary pathways in cardiovascular responses to acute changes in circulating volume.

    PubMed

    Cravo, S L; Lopes, O U; Pedrino, G R

    2011-09-01

    Water deprivation and hypernatremia are major challenges for water and sodium homeostasis. Cellular integrity requires maintenance of water and sodium concentration within narrow limits. This regulation is obtained through engagement of multiple mechanisms and neural pathways that regulate the volume and composition of the extracellular fluid. The purpose of this short review is to summarize the literature on central neural mechanisms underlying cardiovascular, hormonal and autonomic responses to circulating volume changes, and some of the findings obtained in the last 12 years by our laboratory. We review data on neural pathways that start with afferents in the carotid body that project to medullary relays in the nucleus tractus solitarii and caudal ventrolateral medulla, which in turn project to the median preoptic nucleus in the forebrain. We also review data suggesting that noradrenergic A1 cells in the caudal ventrolateral medulla represent an essential link in neural pathways controlling extracellular fluid volume and renal sodium excretion. Finally, recent data from our laboratory suggest that these structures may also be involved in the beneficial effects of intravenous infusion of hypertonic saline on recovery from hemorrhagic shock.

  14. Overview and Management of Dermatologic Events Associated with Targeted Therapies for Medullary Thyroid Cancer

    PubMed Central

    Ciccolini, Kathryn; Kloos, Richard T.; Agulnik, Mark

    2014-01-01

    Background: Treatment options for patients with advanced or metastatic medullary thyroid cancer (MTC) have, in recent years, expanded with the approval of two tyrosine kinase inhibitors (TKIs): vandetanib and cabozantinib. Other agents, including TKIs, are under clinical investigation for MTC. Although patients treated with TKIs are at risk of developing dermatologic adverse events (AE), these untoward events may be mitigated through AE-driven algorithms. Summary: AE-driven algorithms combine effective nonpharmaceutical and pharmaceutical treatment modalities implemented by a multidisciplinary effort that incorporates nursing interventions, patient education, and referrals to pain-management specialists, podiatrists, and dermatologists, as appropriate. Effective AE prevention and management reduce the need for dose interruptions and modifications, allowing patients the opportunity to derive the maximal benefit from TKI therapy, while maintaining quality of life. Conclusions: Optimal use of targeted therapies in the treatment of MTC depends on careful patient selection, interdisciplinary communication, and patient education and encouragement to enhance compliance and safety, optimize consistent dosing, and maximize the use of effective therapies. PMID:24902006

  15. Diagnostic and therapeutic potential of new radiopharmaceutical agents in medullary thyroid carcinoma

    SciTech Connect

    Troncone, L.; Rufini, V.; De Rosa, G.; Testa, A.

    1989-01-01

    Recently developed radiopharmaceuticals have been proposed for imaging medullary thyroid carcinoma (MTC) with some having therapeutic potential. This study compares the imaging results obtained with radioiodinated meta-iodo-benzylguanidine (MIBG), {sup 99m}Tc (V) DMSA, and {sup 131}I F(ab')2 anti-carcinoembryonic antigen (anti-CEA) in a group of MTC patients. In 23 patients {sup 131}I MIBG imaging showed a high specificity (no false-positive results) but a less satisfactory sensitivity (50%). In 12 patients {sup 99m}Tc (V) DMSA revealed a better sensitivity (77%) but a lower specificity (three false-positive results). Positive results were obtained in two of three patients studied with {sup 131}I F(ab')2 anti-CEA. These data suggest that the highly sensitive {sup 99m}Tc (V) DMSA should be considered as a first choice procedure followed by the highly specific radioiodinated MIBG to confirm the initial results. Since radioiodinated MIBG imaging may have therapeutic usefulness, {sup 131}I MIBG was evaluated in an integrated treatment protocol in four cases of proven MTC. The preliminary results obtained were encouraging.

  16. Differential effect of ventrolateral medullary cooling on respiratory muscles of goats.

    PubMed

    Forster, H V; Lowry, T F; Ohtake, P J; Pan, L G; Korducki, M J; Forster, A L

    1995-05-01

    The objective was to determine whether there is an inhomogeneous response of respiratory muscles during cooling-induced ventrolateral medullary (VLM) neuronal dysfunction in anesthetized and awake goats. Thermodes for cooling were chronically implanted on all or portions of rostral, intermediate, and caudal areas of the VLM of 16 adult goats. Electromyograms (EMGs) were obtained from chronically implanted wires in the diaphragm (di), transversus abdominis (TA), and triangularis sterni (TS) muscles. During some periods of cooling in 9 of 16 anesthetized airway-intubated goats, complete cessation of EMGdi coincided with a reduced yet sustained inspiratory flow. In six awake tracheotomized goats, VLM cooling decreased (P < 0.05) EMGdi duration and minute activity more than inspiratory duration and minute ventilation. Cooling thus decreased activation of the diaphragm more than activation of other respiratory muscles. On the other hand, during VLM cooling in 3 of 10 airway-intact awake goats, cessation of inspiratory flow coincided with sustained EMGdi, suggesting that cooling decreased stimulation of the upper airway muscles more than stimulation of the diaphragm. Finally, VLM cooling in a majority of goats decreased EMGTA and EMGTS more than EMGdi. We conclude that VLM neuronal dysfunction has a differential effect on respiratory muscles of adult anesthetized and awake goats.

  17. Effect on breathing of surface ventrolateral medullary cooling in awake, anesthetized and asleep goats.

    PubMed

    Forster, H V; Ohtake, P J; Pan, L G; Lowry, T F

    1997-11-01

    In adult and neonatal goats, we chronically implanted thermodes on the ventrolateral (VLM) medullary surface to create reversible neuronal dysfunction and thereby gain insight into the role of superficial VLM neurons in control of breathing in anesthetized, awake and asleep states. Consistent with data of others, cooling caudal area M and rostral area S caused sustained apnea under anesthesia. However, in the awake and NREM sleep states, cooling at this site caused only a modest reduction in breathing, indicating that neurons at this site are not critical for respiratory rhythm in these states. Moreover, data in the awake state over multiple conditions suggest neurons at this site do not integrate all intracranial and carotid chemoreception. The data suggest though that neurons at this site have a facilitatory-like effect on breathing both unrelated and related to intracranial chemoreception. We believe that this facilitation serves a function similar to the facilitation provided by the carotid chemoreceptors and by sources associated with wakefulness. Accordingly, elimination/attenuation of any one of these three influences (caudal M rostral S VLM, wakefulness, carotid chemoreception) results in a slight decrease in breathing, removal of two of the three results in a greater decrease in breathing, and removal of all three results in sustained apnea.

  18. Axon-glial relations during regeneration of axons in the adult rat anterior medullary velum.

    PubMed

    Berry, M; Hunter, A S; Duncan, A; Lordan, J; Kirvell, S; Tsang, W L; Butt, A M

    1998-12-01

    The anterior medullary velum (AMV) of adult Wistar rats was lesioned in the midsagittal plane, transecting all decussating axons including those of the central projection of the IVth nerve. At selected times up to 200 days after transection, the degenerative and regenerative responses of axons and glia were analyzed using transmission and scanning electron microscopy and immunohistochemistry. In particular, both the capacity of oligodendrocytes to remyelinate regenerated fibers and the stability of the CNS/PNS junctional zone of the IVth nerve rootlet were documented. Transected central AMV axons exhibited four patterns of fiber regeneration in which fibers grew: rostrocaudally in the reactive paralesion neuropil (Group 1); randomly within the AMV (Group 2); into the ipsilateral IVth nerve rootlet, after turning at the lesion edge and growing recurrently through the old degenerated contralateral central trochlear nerve trajectory (Group 3); and ectopically through paralesion tears in the ependyma onto the surface of the IVth ventricle (Group 4). Group 1-3 axons regenerated unperturbed through degenerating central myelin, reactive astrocytes, oligodendrocytes, microglia, and large accumulations of hematogenous macrophages. Only Group 3 axons survived long term in significant numbers, and all became myelinated by oligodendrocytes, ultimately establishing thin sheaths with relatively normal nodal gaps and intersegmental myelin sheath lengths. Schwann cells at the CNS/PNS junction of the IVth nerve rootlet did not invade the CNS, but astrocyte processes grew across the junction into the PNS portion of the IVth nerve. The basal lamina of the junctional glia limitans remained stable throughout the experimental period.

  19. Axon-myelin sheath relations of oligodendrocyte unit phenotypes in the adult rat anterior medullary velum.

    PubMed

    Butt, A M; Ibrahim, M; Berry, M

    1998-04-01

    Axon-oligodendrocyte relations of Rip-immunolabelled and dye-injected oligodendrocyte units are characterised in the adult rat anterior medullary velum (AMV). Each oligodendrocyte unit comprised the oligodendrocyte cell body, processes and the internodal myelin segments they support. Oligodendrocyte units corresponded to classically described type I/II or type III/IV unit phenotypes which respectively myelinated discrete populations of small and large diameter axons, delineated by a myelinated fire diameter of 2-4 microns (diameter of the axon plus its myelin sheath). Within units, mean fibre diameter was directly related to mean internodal length and inversely related to the number of myelin sheaths in the unit. The relationship between fibre diameter and internodal length was retained in units which myelinated axons of different diameters, indicating that axon diameter was an important determinant of the longitudinal dimensions of myelin sheaths. We also show that type III/IV units maintained a far greater volume of myelin than type I/II units. It was concluded that type I/II and III/IV oligodendrocytes represent two functionally and morphologically distinct phenotypes whose distribution densities were determined by the diameter and spatial dispersion of axons.

  20. Measurements of macula densa cell volume changes in isolated and perfused rabbit cortical thick ascending limb. I. Isosmotic and anisosmotic cell volume changes.

    PubMed

    González, E; Salomonsson, M; Müller-Suur, C; Persson, A E

    1988-06-01

    A method to measure time-dependent volume changes in macula densa (MD) cells is described. Cell volume is calculated from cell height measurements for which an image-splitting eyepiece is used. This paper presents the results of experiments designed to investigate the behaviour of the macula densa cells in anisosmotic media, to evaluate the cell volume response to sudden decreases in luminal or peritubular osmolarity and to examine the effect of different luminal NaCl concentrations on the steady-state isosmotic cell volume and on the regulatory volume response to anisosmotic media. The result showed that induced alteration in macula densa cell volume did not change macula densa surface area, but only cell height. The mean control cell height was 13.3 microns +/- 0.4. When MD cells were exposed to a luminal osmolarity of 180 mosM (control 300 mosM) they swelled only to 1.19 +/- 0.02 of the control value and with furosemide present to 1.13 +/- 0.02 or with low NaCl to 1.13 +/- 0.01. While after 5 min of exposure values were 1.15 +/- 0.03, 0.99 +/- 0.02 and 1.02 +/- 0.02, respectively. Addition of furosemide (10(-4) M) to the luminal perfusate (300 mosM) resulted in a rapid decrease in cell height to 0.8 +/- 0.02 in relation to control. When furosemide was removed cell volume was restituted (0.98 +/- 0.03). When luminal perfusate was replaced by mannitol and (12 mM Na+, 7 mM Cl-) cell volume decreased to 0.83 +/- 0.02 of the control value.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Sustainability, Participatory Culture, and the Performance of Democracy: Ascendant Sites of Theory and Practice in Art Education

    ERIC Educational Resources Information Center

    Blandy, Doug

    2011-01-01

    Art education is a systemic and extensive network within which children, youth, and adults make and learn about material culture. This lecture considers three sites of theory and practice that I see as ascendant in circulating through this network. These sites are sustainability, participatory culture, and performing democracy. I argue that…

  2. Mesenchymal state of intimal cells may explain higher propensity to ascending aortic aneurysm in bicuspid aortic valves

    PubMed Central

    Maleki, Shohreh; Kjellqvist, Sanela; Paloschi, Valentina; Magné, Joelle; Branca, Rui Miguel Mamede; Du, Lei; Hultenby, Kjell; Petrini, Johan; Fuxe, Jonas; Dietz, Harry C.; Loeys, Bart; Van Laer, Lut; McCallion, Andrew S.; Mertens, Luc; Mital, Seema; Mohamed, Salah A.; Andelfinger, Gregor; Lehtiö, Janne; Franco-Cereceda, Anders; Eriksson, Per; Björck, Hanna M.

    2016-01-01

    Individuals with a bicuspid aortic valve (BAV) are at significantly higher risk of developing aortic complications than individuals with tricuspid aortic valves (TAV) and defective signaling during the embryonic development and/or life time exposure to abnormal hemodynamic have been proposed as underlying factors. However, an explanation for the molecular mechanisms of aortopathy in BAV has not yet been provided. We combined proteomics, RNA analyses, immunohistochemistry, and electron microscopy to identify molecular differences in samples of non-dilated ascending aortas from BAV (N = 62) and TAV (N = 54) patients. Proteomic analysis was also performed for dilated aortas (N = 6 BAV and N = 5 TAV) to gain further insight into the aortopathy of BAV. Our results collectively showed the molecular signature of an endothelial/epithelial-mesenchymal (EndMT/EMT) transition-like process, associated with instability of intimal cell junctions and activation of RHOA pathway in the intima and media layers of ascending aorta in BAV patients. We propose that an improper regulation of EndMT/EMT during the spatiotemporally related embryogenesis of semilunar valves and ascending aorta in BAV individuals may result in aortic immaturity and instability prior to dilation. Exasperation of EndMT/EMT state in post embryonic life and/or exposure to non-physiological hemodynamic could lead to the aneurysm of ascending aorta in BAV individuals. PMID:27779199

  3. The origin of thick discs

    NASA Astrophysics Data System (ADS)

    Comerón, Sébastien

    2015-03-01

    Thick discs are defined to be disc-like components with a scale height larger than that of the classical discs. They are ubiquitous (Yoachim & Dalcanton 2006; Comerón et al. 2011a), they are made of mostly old and metal-poor stars and are most easily detected in close to edge-on galaxies. Their origin has been considered mysterious and several formation theories have been proposed: • The thick disc being formed secularly by thin disc stars heated by disc overdensities such as giant molecular clouds or spiral arms (Villumsen 1985, ApJ, 290, 75) and by stars moved outwards from their original orbits by radial migration mechanisms (Schönrich & Binney 2009). • The thick disc being formed by the heating of the thin disc by satellites (Quinn et al. 1993) and the tidal stripping of them (Abadi et al. 2003). • The thick disc being formed fast and already thick at high redshift in an highly unstable disc. Inside that thick disc, a thin disc would form afterwards as suggested by Elemgreen & Elmegreen (2006). • The thick disc being formed originally thick at high redshift by the merger of gas-rich protogalactic fragments and a thin disc forming afterwards within it (Brook et al. 2007). The first mechanism is a secular evolution mechanism. The time-scale of the second one is dependent on the merger history of the main galaxy. In the two last mechanisms, the thick disc forms already thick in a short time-scale at high redshift. Recent Milky Way studies, (see, e.g., Bovy et al. 2012), have shown indications that there is no discontinuity between the thin and the thick disc chemical and kinematic properties. Instead, those studies indicate the presence of a monotonic distribution of disc thicknesses. This would suggest a secular origin for the Milky Way thick disc. Studies in external galaxies (Yoachim & Dalcanton 2006; Comerón et al. 2011b), have shown that low-mass disc galaxies have thick disc relative masses much larger than those found in large-mass galaxies

  4. NFLUX PRE: Validation of New Specific Humidity, Surface Air Temperature, and Wind Speed Algorithms for Ascending/Descending Directions and Clear or Cloudy Conditions

    DTIC Science & Technology

    2015-06-18

    Validation of New Specific Humidity, Surface Air Temperature , and Wind Speed Algorithms for Ascending/ Descending Directions and Clear or Cloudy...LIMITATION OF ABSTRACT NFLUX PRE: Validation of New Specific Humidity, Surface Air Temperature , and Wind Speed Algorithms for Ascending/Descending...satellite retrieval algorithms. In addition to data from the Special Sensor Microwave Imager/Sounder (SSMIS) and the Advanced Microwave Sounding

  5. Pulsed Lidar Measurements of Atmospheric CO2 Column Absorption in the ASCENDS 2011 Airborne Campaign

    NASA Technical Reports Server (NTRS)

    Abshire, James B.; Riris, Haris; Allan, Graham R.; Ramanathan, Anand; Hasselbrack, William E.; Mao, Jianping; Weaver, Clark; Browell, Edward V.

    2012-01-01

    We have previously demonstrated an efficient pulsed, wavelength-resolved IPDA lidar technique for measuring the tropospheric CO2 concentrations as a candidate for NASA's ASCENDS mission. Our team participated in the 2010 ASCENDS airborne campaigns we flew airborne version of the CO2 and O2 lidar on the NASA DC-8. The CO2 lidar measures the atmospheric backscatter profiles and shape of the 1572.33 nm absorption line using 250 mW average laser power, 30 wavelength samples per scan and 300 scans per second. Most flights had 5-6 altitude steps to greater than 12 km, and clear CO2 line shapes were observed at all altitudes. Our post-flight analysis estimated the Iidar range and pulse energies at each wavelength every second. We then solved for the best-fit CO2 absorption line shape, and calculated the Differential Optical Depth (DOD) at the line peak. We compared these to CO2 DODs calculated from spectroscopy based on HITRAN 2008 and the conditions from airborne in-situ readings. Analysis of the 2010 measurements over the Pacific Ocean and Lamont OK shows the expected -linear change of the peak DOD with altitude. For measurements at altitudes greater than 6 km the random errors were approximately 0.3 ppm for 80 sec averaging times. After the 2010 flights we improved the airborne lidar's scan uniformity, calibration and receiver sensitivity. Our team participated in the seven ASCENDS science flights during late July and August 2011. These flights were made over a wide variety of surface and cloud conditions near the US, including over the central valley of California, over several mountain ranges, over both broken and solid stratus cloud deck over the Pacific Ocean, snow patches on mountain tops, over thin and broken clouds above the US Southwest and Iowa, and over forests near the WLEF tower in Wisconsin. Analyses show the retrievals of lidar range and CO2 column absorption, as wen as estimates of CO2 mixing ratio worked well when measuring over topography with rapidly

  6. Pulsed Lidar Measurements of Atmospheric CO2 Column Absorption in the ASCENDS 2011 Airborne Campaign

    NASA Astrophysics Data System (ADS)

    Abshire, J. B.; Riris, H.; Allan, G. R.; Ramanathan, A.; Hasselbrack, W.; Mao, J.; Weaver, C. J.; Browell, E. V.

    2012-12-01

    We have previously demonstrated an efficient pulsed, wavelength-resolved IPDA lidar technique for measuring the tropospheric CO2 concentrations as a candidate for NASA's ASCENDS mission. Our team participated in the 2010 ASCENDS airborne campaigns we flew airborne version of the CO2 and O2 lidar on the NASA DC-8. The CO2 lidar measures the atmospheric backscatter profiles and shape of the 1572.33 nm absorption line using 250 mW average laser power, 30 wavelength samples per scan and 300 scans per second. Most flights had 5-6 altitude steps to > 12 km, and clear CO2 line shapes were observed at all altitudes. Our post-flight analysis estimated the lidar range and pulse energies at each wavelength every second. We then solved for the best-fit CO2 absorption line shape, and calculated the Differential Optical Depth (DOD) at the line peak. We compared these to CO2 DODs calculated from spectroscopy based on HITRAN 2008 and the conditions from airborne in-situ readings. Analysis of the 2010 measurements over the Pacific Ocean and Lamont OK shows the expected ~linear change of the peak DOD with altitude. For measurements at altitudes > 6 km the random errors were ~ 0.3 ppm for 80 sec averaging times. After the 2010 flights we improved the airborne lidar's scan uniformity, calibration and receiver sensitivity. Our team participated in the seven ASCENDS science flights during late July and August 2011. These flights were made over a wide variety of surface and cloud conditions near the US, including over the central valley of California, over several mountain ranges, over both broken and solid stratus cloud deck over the Pacific Ocean, snow patches on mountain tops, over thin and broken clouds above the US Southwest and Iowa, and over forests near the WLEF tower in Wisconsin. Analyses show the retrievals of lidar range and CO2 column absorption, as well as estimates of CO2 mixing ratio worked well when measuring over topography with rapidly changing height and reflectivity

  7. Pulsed Lidar Measurements of Atmospheric CO2 Column Concentration in the ASCENDS 2014 Airborne Campaign

    NASA Astrophysics Data System (ADS)

    Abshire, J. B.; Ramanathan, A. K.; Mao, J.; Riris, H.; Allan, G. R.; Hasselbrack, W. E.; Chen, J. R.

    2015-12-01

    We report progress in demonstrating a pulsed, wavelength-resolved IPDA lidar technique for measuring the tropospheric CO2 concentrations as a candidate for NASA's ASCENDS mission. The CO2 lidar flies on NASA's DC-8 aircraft and measures the atmospheric backscatter profiles and shape of the 1572.33 nm absorption line by using 30 wavelength samples distributed across the lube. Our post-flight analysis estimates the lidar range and pulse energies at each wavelength 10 times per second. The retrievals solve for the optimum CO2 absorption line shape and the column average CO2 concentrations using radiative transfer calculations based on HITRAN, the aircraft altitude, range to the scattering surface, and the atmospheric conditions. We compare these to CO2 concentrations sampled by in-situ sensors on the aircraft. The number of wavelength samples can be reduced in the retrievals. During the ASCENDS airborne campaign in 2013 two flights were made in February over snow in the Rocky Mountains and the Central Plains allowing measurement of snow-covered surface reflectivity. Several improvements were made to the lidar for the 2014 campaign. These included using a new step-locked laser diode source, and incorporating a new HgCdTe APD detector and analog digitizer into the lidar receiver. Testing showed this detector had higher sensitivity, analog response, and a more linear dynamic range than the PMT detector used previously. In 2014 flights were made in late August and early September over the California Central Valley, the redwood forests along the California coast, two desert areas in Nevada and California, and two flights above growing agriculture in Iowa. Two flights were also made under OCO-2 satellite ground tracks. Analyses show the retrievals of lidar range and CO2 column absorption, and mixing ratio worked well when measuring over topography with rapidly changing height and reflectivity, and through thin clouds and aerosol scattering. The lidar measurements clearly

  8. Early Cellular Changes in the Ascending Aorta and Myocardium in a Swine Model of Metabolic Syndrome

    PubMed Central

    Mahmood, Feroze; Owais, Khurram; Bardia, Amit; Khabbaz, Kamal R.; Liu, David; Senthilnathan, Venkatachalam; Lassaletta, Antonio D.; Sellke, Frank; Matyal, Robina

    2016-01-01

    Background Metabolic syndrome is associated with pathological remodeling of the heart and adjacent vessels. The early biochemical and cellular changes underlying the vascular damage are not fully understood. In this study, we sought to establish the nature, extent, and initial timeline of cytochemical derangements underlying reduced ventriculo-arterial compliance in a swine model of metabolic syndrome. Methods Yorkshire swine (n = 8 per group) were fed a normal diet (ND) or a high-cholesterol (HCD) for 12 weeks. Myocardial function and blood flow was assessed before harvesting the heart. Immuno-blotting and immuno-histochemical staining were used to assess the cellular changes in the myocardium, ascending aorta and left anterior descending artery (LAD). Results There was significant increase in body mass index, blood glucose and mean arterial pressures (p = 0.002, p = 0.001 and p = 0.024 respectively) in HCD group. At the cellular level there was significant increase in anti-apoptotic factors p-Akt (p = 0.007 and p = 0.002) and Bcl-xL (p = 0.05 and p = 0.01) in the HCD aorta and myocardium, respectively. Pro-fibrotic markers TGF-β (p = 0.01), pSmad1/5 (p = 0.03) and MMP-9 (p = 0.005) were significantly increased in the HCD aorta. The levels of pro-apoptotic p38MAPK, Apaf-1 and cleaved Caspase3 were significantly increased in aorta of HCD (p = 0.03, p = 0.04 and p = 0.007 respectively). Similar changes in coronary arteries were not observed in either group. Functionally, the high cholesterol diet resulted in significant increase in ventricular end systolic pressure and–dp/dt (p = 0.05 and p = 0.007 respectively) in the HCD group. Conclusion Preclinical metabolic syndrome initiates pro-apoptosis and pro-fibrosis pathways in the heart and ascending aorta, while sparing coronary arteries at this early stage of dietary modification. PMID:26766185

  9. [Application of a tape-like bandage for the ascending aorta in its poststenotic dilation and correction of the aortal valve stenosis].

    PubMed

    Popov, V V; Bol'shak, A A

    2014-06-01

    The aortal valve prosthesis in combination with a tape-like bandage of ascending aorta application was performed in 106 patients, suffering a failure with predominance of the aortal valve stenosis in conjunction with the ascending aorta poststenotic dilation, in a 2005 - 2014 yrs period in the clinic. The hospital lethality have constituted 0.9%. In accordance to echocardiography, the ascending aorta diameter preoperatively have constituted (48.7 +/- 1.4) mm at average, before discharge from the hospital--(40.1 +/- 1.2) mm, in late follow-up period--(41.3 +/- 1.2) mm. It is expedient to recommend the original method of a tape-like bandage of ascending aorta from the base of noncoronary sinus in the aortal sinuses dilation (45 mm and more) in combination with the aortal valve prosthesis in poststenotic dilation of ascending aorta.

  10. Carcinoma of the collecting ducts of Bellini and renal medullary carcinoma: clinicopathologic analysis of 52 cases of rare aggressive subtypes of renal cell carcinoma with a focus on their interrelationship.

    PubMed

    Gupta, Ruta; Billis, Athanase; Shah, Rajal B; Moch, Holger; Osunkoya, Adeboye O; Jochum, Wolfram; Hes, Ondrej; Bacchi, Carlos E; de Castro, Marilia G; Hansel, Donna E; Zhou, Ming; Vankalakunti, Mahesha; Salles, Paulo G; Cabrera, Rafael A; Gown, Allen M; Amin, Mahul B

    2012-09-01

    Carcinoma of the collecting ducts of Bellini and renal medullary carcinoma are rare aggressive neoplasms of putative distal nephron origin. First described in 1949, case reports and review articles constitute a major source of information on collecting duct carcinoma, whereas Davis and colleagues and the pediatric tumor registry have contributed the seminal works on renal medullary carcinoma. Here we present a detailed study of collecting duct carcinoma (n=39) and renal medullary carcinoma (n=13), characterizing these rare neoplasms and analyzing their interrelationship. Both collecting duct carcinoma and renal medullary carcinoma exhibited significant similarities, such as predilection for the right kidney, tumor mass with an epicenter in the renal medulla, and a mean size of 7 cm. Overall, both tumors exhibited a poorly differentiated adenocarcinoma histology with desmoplastic stromal response (100%), inflammatory infiltrate (100%), frequent perinephric extension (collecting duct carcinoma: 97%; renal medullary carcinoma: 83%), lymphovascular invasion (100%), intraluminal mucin (collecting duct carcinoma: 42%; renal medullary carcinoma: 73%), high nuclear grade (97%), overlapping immunoreactivity for Ulex europaeus agglutinin 1 (collecting duct carcinoma: 75%; renal medullary carcinoma:55%), CK7 (collecting duct carcinoma: 44%; renal medullary carcinoma: 71%), and high-molecular weight cytokeratin (collecting duct carcinoma: 26%; renal medullary carcinoma: 29%), and nonimmunoreactivity for Ksp-cadherin. Histologically, collecting duct carcinoma frequently had tubular, tubulopapillary, or irregular glandular architecture, whereas renal medullary carcinoma commonly demonstrated islands of anastomosing tubules and cords forming irregular microcystic spaces. Multiple metastases to the lymph nodes, lung, bone, and liver were observed in both categories at presentation (collecting duct carcinoma: 17%; renal medullary carcinoma: 36%). Only patients with organ

  11. Finite element analysis of the effect of medullary contact on fracture healing and remodeling in the intramedullary interlocking nail-fixed tibia fracture.

    PubMed

    Wang, Haosen; Hao, Zhixiu; Wen, Shizhu

    2017-04-01

    Intramedullary interlocking nail is an effective treatment for tibial diaphyseal fracture. The contact between medullary rod and diaphyseal cortex is able to enhance fracture stability. However, how and to what degree the contact affects fracture healing and subsequent bone remodeling is still unclear. To investigate this, fracture healing and remodeling algorithms were combined, improved, and used to simulate the healing and remodeling processes in a transverse tibial diaphyseal fracture fixed with an intramedullary interlocking nail device. Two different diaphyseal fracture statuses, three different initial loading levels, and two nail materials were considered. The results showed that the medullary contact could significantly enhance the fixation stability; the strain reduction was up to 80% in the initial granulation callus. However, low initial loading level was found to be a more potential risk factor for the insufficient loading-induced nonunion other than medullary contact and stiffer nail material. Furthermore, the stabilizing effect of medullary contact diminished when stiff bone tissue formed in the callus; thus, the remodeling in the long-term was not affected by medullary contact. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Nitrergic ventro-medial medullary neurons activated during cholinergically induced active (REM) sleep in the cat

    PubMed Central

    Pose, Inés; Sampogna, Sharon; Chase, Michael H.; Morales, Francisco R.

    2010-01-01

    The rostral ventro-medial medullary reticular formation is a complex structure that is involved with a variety of motor functions. It contains glycinergic neurons that are activated during active (REM) sleep (AS); these neurons appear to be responsible for the postsynaptic inhibition of motoneurons that occurs during this state. We have reported that neurons in this same region contain nitric oxide (NO) synthase and that they innervate brainstem motor pools. In the present study we examined the c-fos expression of these neurons after carbachol-induced active sleep (C-AS). Three control and four experimental cats were employed to identify c-fos expressing nitrergic neurons using immunocytochemical techniques to detect the Fos protein together with neuronal nitric oxide synthase (nNOS) or NADPH-diaphorase activity. The classical neurotransmitter content of the nitrergic cells in this region was examined through the combination of immunocytochemical techniques for the detection of glutamate, glycine, choline acetyltransferase (ChAT), tyrosine hydroxilase (TH) or GABA together with nNOS. During C-AS, there was a 1074% increase in the number of nitrergic neurons that expressed c-fos. These neurons did not contain glycine, ChAT, TH or GABA, but a subpopulation (15%) of them displayed glutamate-like immunoreactivity. Therefore, some of these neurons contain both an excitatory neurotransmitter (glutamate) and an excitatory neuromodulator (NO); the neurotransmitter content of the rest of them remains to be determined. Because some of the nitrergic neurons innervate brainstem motoneurons it is possible that they participate in the generation of tonic and excitatory phasic motor events that occur during AS. We also suggest that these nitrergic neurons may be involved in autonomic regulation during this state. In addition, because NO has trophic effects on target neurons, the present findings represent the first, albeit indirect, evidence for a possible trophic function of

  13. Subpopulations of PKCγ interneurons within the medullary dorsal horn revealed by electrophysiologic and morphologic approach.

    PubMed

    Alba-Delgado, Cristina; El Khoueiry, Corinne; Peirs, Cédric; Dallel, Radhouane; Artola, Alain; Antri, Myriam

    2015-09-01

    Mechanical allodynia, a cardinal symptom of persistent pain, is associated with the unmasking of usually blocked local circuits within the superficial spinal or medullary dorsal horn (MDH) through which low-threshold mechanical inputs can gain access to the lamina I nociceptive output neurons. Specific interneurons located within inner lamina II (IIi) and expressing the gamma isoform of protein kinase C (PKCγ⁺) have been shown to be key elements for such circuits. However, their morphologic and electrophysiologic features are still unknown. Using whole-cell patch-clamp recordings and immunohistochemical techniques in slices of adult rat MDH, we characterized such lamina IIi PKCγ⁺ interneurons and compared them with neighboring PKCγ⁻ interneurons. Our results reveal that PKCγ⁺ interneurons display very specific activity and response properties. Compared with PKCγ⁻ interneurons, they exhibit a smaller membrane input resistance and rheobase, leading to a lower threshold for action potentials. Consistently, more than half of PKCγ⁺ interneurons respond with tonic firing to step current. They also receive a weaker excitatory synaptic drive. Most PKCγ⁺ interneurons express Ih currents. The neurites of PKCγ⁺ interneurons arborize extensively within lamina IIi, can spread dorsally into lamina IIo, but never reach lamina I. In addition, at least 2 morphologically and functionally different subpopulations of PKCγ⁺ interneurons can be identified: central and radial PKCγ⁺ interneurons. The former exhibit a lower membrane input resistance, rheobase and, thus, action potential threshold, and less PKCγ⁺ immunoreactivity than the latter. These 2 subpopulations might thus differently contribute to the gating of dorsally directed circuits within the MDH underlying mechanical allodynia.

  14. A Genomic Alternative to Identify Medullary Thyroid Cancer Preoperatively in Thyroid Nodules with Indeterminate Cytology

    PubMed Central

    Monroe, Robert J.; Traweek, S. Thomas; Lanman, Richard B.; Kennedy, Giulia C.

    2016-01-01

    Background: The use of calcitonin screening for the rare medullary thyroid cancer (MTC) is controversial due to questions of efficacy, accuracy, and cost-effectiveness. This study reports the results of a large prospective validation using a machine-trained algorithm (MTC Classifier) to preoperatively identify MTC in fine-needle aspiration biopsies in lieu of calcitonin measurements. Methods: Cytology analysis on a prospective consecutive series of 50,430 thyroid nodule biopsies yielded a total of 7815 indeterminate (Bethesda categories III/IV) cases, which were tested with the MTC classifier. A prospective, consecutively submitted series of 2673 Bethesda III–VI cases with cytology determined locally was also evaluated. RNA was isolated and tested for the MTC Classifier using microarrays. Results: Forty-three cases were positive by the MTC Classifier among 10,488 tested nodules (0.4%), consistent with the low prevalence of MTC. Of these, all but one was histologically or biochemically confirmed as MTC, yielding a positive predictive value (PPV) of 98%. Of the positive cases, only 19 (44%) had been specifically suspected of MTC by cytology, highlighting the limitations of light microscopy to detect this disease. Three surgically confirmed MTC cases that were detected by the MTC Classifier had low basal serum calcitonin values, indicating these would have been missed by traditional calcitonin screening methods. A pooled analysis of three independent validation sets demonstrates high test sensitivity (97.9%), specificity (99.8%), PPV (97.9%), and negative predictive value (99.8%). Conclusions: A clinical paradigm is proposed, whereby cytologically indeterminate thyroid nodules being tested for common malignancies using gene expression can be simultaneously tested for MTC using the same genomic assay at no added cost. PMID:26992356

  15. Ursolic acid from Trailliaedoxa gracilis induces apoptosis in medullary thyroid carcinoma cells

    PubMed Central

    AGUIRIANO-MOSER, VICTOR; SVEJDA, BERNHARD; LI, ZENG-XIA; STURM, SONJA; STUPPNER, HERMANN; INGOLIC, ELISABETH; HÖGER, HARALD; SIEGL, VERONIKA; MEIER-ALLARD, NATHALIE; SADJAK, ANTON; PFRAGNER, ROSWITHA

    2015-01-01

    Medullary thyroid carcinoma (MTC) originates from the C-cells of the thyroid and is not sensitive to radiation or chemotherapy. Therefore, surgical removal of the tumor tissue in its entirety is the only curative treatment for MTC. The present study aimed to examine the potential mechanisms of action of extracts of Trailliaedoxa gracilis (TG; WW Smith & Forrest), a plant from the province of Sichuan, China, and of ursolic acid (UA), a pentacyclic triterpen present in TG, on the MTC-SK MTC cell line. A total of 13 TG fractions and UA were examined in vitro for their effects on cell morphology, cell number, proliferation and rates of apoptosis. Reverse transcription-quantitative polymerase chain reaction of nuclear factor-κB essential modifier (NEMO) was performed to delineate the role of the apoptotic pathway following treatment with UA. TG and UA were examined in vivo in xenotransplanted MTC-bearing severe combined immunodeficient mice. The TG fractions exhibited antiproliferative effects, with inhibition of mitochondrial activity in the tumor cells at concentrations, which caused no impairment of the normal control cells. The apoptotic rates of the MTC-SK cells treated with the TG fractions and UA were determined, in which no marked tumor inhibition was observed in the treated MTC-mice, and no change in the expression of NEMO was detected in the treated MTC-SK cells. The observation of early-onset activation of caspase 8 suggested that the responsible factor was linked to NEMO, an anti-apoptotic protein. However, no differences in the mRNA transcription levels of NEMO were detected in MTC-SK cells treated with UA, suggesting that this protein was not associated with the signal transducer and activator of transcription 3 pathway. PMID:26151624

  16. Early diagnosis of and surgical strategy for adrenal medullary disease in MEN II gene carriers

    SciTech Connect

    Jansson, S.; Tisell, L.E.; Fjaelling, M.L.; Lindberg, S.; Jacobsson, L.; Zachrisson, B.F.

    1988-01-01

    Sixteen multiple endocrine neoplasia type II (MEN II) gene carriers--12 who had undergone thyroidectomy because of medullary carcinoma of the thyroid and 4 whose thyroid glands had been removed because of C cell hyperplasia--were examined for the presence of pheochromocytomas. No patient had sought medical advice for pheochromocytoma symptoms. Fourteen patients had MEN IIa syndromes, one patient had a MEN IIb and another patient had a mixed syndrome of von Recklinghausen's neurofibromatosis and MEN II. Eight patients had undergone unilateral adrenalectomy for pheochromocytoma 11 +/- 4 years before. The patients underwent clinical examination, determination of the urinary excretion of catecholamines and metabolites, and /sup 131/I-metaiodobenzylguanidine (/sup 131/I-MIBG) and CAT scans. /sup 131/I-MIBG scanning was performed with images 1, 4, and 7 days after the radionuclide injection. In seven of eight patients who had undergone unilateral adrenalectomies, the /sup 131/I-MIBG scans showed accumulation of the radionuclide in the remaining adrenal gland. Bilateral adrenal accumulation of the radionuclide was demonstrated in seven of eight MEN IIa gene carriers who had not undergone adrenalectomy. Five patients, two of whom had undergone adrenalectomy, were found to have unilateral pheochromocytomas less than 2 cm in diameter. Only one of these five patients had an elevated excretion of urinary catecholamines. Between day 4 and day 7 after /sup 131/I-MIBG injection, adrenal glands with pheochromocytomas increased their relative accumulation of the radionuclide significantly more (p less than 0.02) than did adrenal glands without any demonstrable pheochromocytomas. All the pheochromocytomas were viewed by means of CAT scans.

  17. Effect of an Outreach Programme on Vandetanib Safety in Medullary Thyroid Cancer

    PubMed Central

    Bastholt, Lars; Kreissl, Michael C.; Führer, Dagmar; Maia, Ana L.; Locati, Laura D.; Maciel, Léa; Wu, Yi; Heller, Kevin N.; Webster, Alan; Elisei, Rossella

    2016-01-01

    Objectives Effective management of adverse events (AEs) following vandetanib treatment is important to maximize clinical benefits. We examined whether more frequent contact with vandetanib-treated patients reduced AEs of CTCAE grade 2 or higher. Study Design In this open-label, multicentre, phase III study, patients with locally advanced or metastatic medullary thyroid cancer were randomized to a patient outreach programme (outreach) or a standard AE monitoring schedule (vandetanib control) for 52 weeks. In addition to standard AE monitoring, patients in the outreach arm were contacted every 2 weeks by telephone/during their clinic visit for specific AE questioning related to diarrhoea, nausea, vomiting, fatigue, headache and rash. Patients received vandetanib at 200 or 300 mg/day, depending on the creatinine levels at screening. Results Altogether, 205 patients were randomized (outreach, n = 103; vandetanib control, n = 102). This study did not meet its primary objective; the mean percentage of time patients experienced at least one AE of grade 2 or higher was higher for the outreach group (51.65%) than for the vandetanib control group (45.19%); the difference was not statistically significant (t statistic: 1.29; 95% CI −3.44 to 16.37%; p = 0.199). The most frequently reported AEs were diarrhoea (56.9% for the outreach group vs. 46.6% for the vandetanib controls), hypertension (36.3 vs. 31.1%), rash (25.5 vs. 24.3%) and nausea (25.5% vs. 18.4%), and the most frequently reported AEs of grade 2 or higher were hypertension (33.3 vs. 23.3%), diarrhoea (26.5 vs. 24.3%) and dermatitis acneiform (11.8 vs. 9.7%). Conclusions Additional outreach to patients treated with vandetanib had no impact on the rate or severity of AEs compared to the standard AE monitoring schedule. AEs were consistent with the known safety profile of vandetanib. PMID:27843809

  18. Differential effects of kainic acid lesions in medullary raphe on cough and sneeze in anesthetized rabbits.

    PubMed

    Simera, M; Poliacek, I; Veternik, M; Dobrolubov, B; Cibulka, M; Barani, H; Visnovcova, N; Jakus, J

    2013-01-01

    The effects of microinjections of the excitatory neurotoxin kainic acid (2 mg/ml; 49 ± 1 nl) on the mechanically induced tracheobronchial cough, sneeze, and solitary expulsions from the trachea were examined in 11 anesthetized rabbits. Kainic acid was injected into the medulla (1.6-2.8 mm rostral to the obex, 1.4-1.6 and 2.9-3.2 mm below the dorsal medullary surface). Blood pressure, esophageal pressure (EP), and electromyograms (EMGs) of the diaphragm (DIA) and abdominal muscles (ABD) were recorded. Kainic acid reduced the number of coughs (means ± SE) from 3.8 ± 2.0 to 0.9 ± 0.7 (p = 0.016), the amplitude of DIA cough from 90 ± 11 to 42 ± 13 % (p = 0.004), ABD EMG moving average from 103 ± 9 to 37 ± 15 % (p = 0.006), and inspiratory from 0.67 ± 0.13 to 0.36 ± 0.12 kPa (p = 0.013) and expiratory EP from 1.70 ± 0.54 to 0.89 ± 0.46 kPa (p = 0.008). Kainic acid had no effect on the number of sneeze reflexes nor did it affect solitary expulsions from the trachea. These effects were accompanied by significant increases in systemic blood pressure and respiratory rate. Spatiotemporal analysis of the cough and sneeze reflexes revealed increases in the duration of cough active expiratory phase, in the intervals between maxima of DIA and ABD EMG discharges, and in the active portion of total cough phase duration. Our findings suggest a diverse role of raphe neurons in the central control of motor airway responses such as coughing and sneezing. A complex function of raphe neurons in the generation of the cough motor pattern also is suggested.

  19. Preclinical testing of selective Aurora kinase inhibitors on a medullary thyroid carcinoma-derived cell line.

    PubMed

    Tuccilli, Chiara; Baldini, Enke; Prinzi, Natalie; Morrone, Stefania; Sorrenti, Salvatore; Filippini, Angelo; Catania, Antonio; Alessandrini, Stefania; Rendina, Roberta; Coccaro, Carmela; D'Armiento, Massimino; Ulisse, Salvatore

    2016-05-01

    Deregulated expression of the Aurora kinases (Aurora-A, B, and C) is thought to be involved in cell malignant transformation and genomic instability in several cancer types. Over the last decade, a number of small-molecule inhibitors of Aurora kinases have been developed, which have proved to efficiently restrain malignant cell growth and tumorigenicity. Regarding medullary thyroid carcinoma (MTC), we previously showed the efficacy of a pan-Aurora kinase inhibitor (MK-0457) in impairing growth and survival of the MTC-derived cell line TT. In the present study, we sought to establish if one of the Aurora kinases might represent a preferential target for MTC therapy. The effects of selective inhibitors of Aurora-A (MLN8237) and Aurora-B (AZD1152) were analyzed on TT cell proliferation, apoptosis, cell cycle, and ploidy. The two inhibitors reduced TT cell proliferation in a time- and dose-dependent manner, with IC50 of 19.0 ± 2.4 nM for MLN8237 and 401.6 ± 44.1 nM for AZD1152. Immunofluorescence experiments confirmed that AZD1152 inhibited phosphorylation of histone H3 (Ser10) by Aurora-B, while it did not affect Aurora-A autophosphorylation. MLN8237 inhibited Aurora-A autophosphorylation as expected, but at concentrations required to achieve the maximum antiproliferative effects it also abolished H3 (Ser10) phosphorylation. Cytofluorimetry experiments showed that both inhibitors induced accumulation of cells in G2/M phase and increased the subG0/G1 fraction and polyploidy. Finally, both inhibitors triggered apoptosis. We demonstrated that inhibition of either Aurora-A or Aurora-B has antiproliferative effects on TT cells, and thus it would be worthwhile to further investigate the therapeutical potential of Aurora kinase inhibitors in MTC treatment.

  20. Medullary Carcinoma of the Penis: A Distinctive HPV-related Neoplasm: A Report of 12 Cases.

    PubMed

    Cañete-Portillo, Sofía; Clavero, Omar; Sanchez, Diego F; Silvero, Arturo; Abed, Francisco; Rodriguez, Ingrid M; Ayala, Gustavo; Alemany, Laia; Munoz, Nubia; de Sanjose, Silvia; Quint, Wim; Bosch, Francesc X; Cubilla, Antonio L

    2017-04-01

    A third to half of penile invasive squamous cell carcinomas are human papillomavirus (HPV) related. Warty (condylomatous), warty-basaloid, and basaloid carcinomas are the most common subtypes associated with HPV. Less frequent are clear cell and lymphoepithelioma-like carcinomas. Here we report a novel penile tumor associated with HPV. Twelve cases were selected from 1010 penile carcinomas, part of an international HPV detection study conducted at the Institut Català d'Oncologia, Barcelona, Spain. Immunostaining with p16 was performed on all cases, and HPV-mRNA detection was also performed. En bloc full tumor staining was the utilized criteria for positivity of p16. For HPV-DNA detection, whole-tissue section polymerase chain reaction analysis was performed by SPF10-DEIA-LiPA25 (version 1). The patients' ages ranged from 42 to 92 years (average, 71 y). The tumor was most commonly located in the glans. A characteristic microscopic finding was the presence of a moderate to dense tumor-associated inflammatory cell infiltrate composed of neutrophils, lymphocytes, plasma cells, or eosinophils. Tumors grew in large solid sheets, nests, or had a trabecular pattern. Cells were large and poorly differentiated or anaplastic. Keratinization was minimal or absent. Nuclei were large with prominent nucleoli. Mitoses were numerous. Tumor necrosis was common. Deep invasion of the corpora cavernosa was frequent. p16 and HPV-DNA were positive in all cases, whereas mRNA detection was positive in 9 cases only. The prevalent genotype was HPV16 (9 cases, 75%). Other genotypes were HPVs 58, 33, and 66. Medullary carcinomas of the penis are morphologically distinctive HPV-related high-grade neoplasms affecting older individuals. More studies are necessary to delineate the epidemiological, clinical, and molecular features of this unusual penile neoplasm.

  1. Plasticity of auditory medullary-midbrain connectivity across metamorphic development in the bullfrog, Rana catesbeiana.

    PubMed

    Horowitz, Seth S; Chapman, Judith A; Simmons, Andrea Megela

    2007-01-01

    On the basis of patterns of anterograde, retrograde, and bi-directional transport of tracers from both the superior olivary nucleus (SON) and the torus semicircularis (TS), we report anatomical changes in brainstem connectivity across metamorphic development in the bullfrog, Rana catesbeiana. In early and late stages of larval development (Gosner stages 25-37), anterograde or bi-directional tracers injected into the SON produce terminal/fiber label in the contralateral SON and in the ipsilateral TS. Between stages 38-41 (deaf period), only sparse or no terminal/fiber label is visible in these target nuclei. During metamorphic climax (stages 42-46), terminal/fiber label reappears in both the contralateral SON and in the ipsilateral TS, and now also in the contralateral TS. Injections of retrograde tracers into the SON fail to label cell bodies in the ipsilateral TS in deaf period animals, mirroring the previously-reported failure of retrograde transport from the TS to the ipsilateral SON during this developmental time. Bilateral cell body label emerges in the dorsal medullary nucleus and the lateral vestibular nucleus bilaterally as a result of SON transport during the late larval period, while cell body label in the contralateral TS emerges during climax. At all larval stages, injections into the SON produce anterograde and retrograde label in the medial vestibular nucleus bilaterally. These data show anatomical stability in some pathways and plasticity in others during larval development, with the most dramatic changes occurring during the deaf period and metamorphic climax. Animals in metamorphic climax show patterns of connectivity similar to that of froglets and adults, indicating the maturation during climax of central anatomical substrates for hearing in air.

  2. Efficacy of tracheostomy for central alveolar hypoventilation syndrome caused by lateral medullary infarction.

    PubMed

    Mishina, Masahiro; Ohkubo, Seiji; Kamiya, Nobuo; Abe, Arata; Suda, Satoshi; Sakamaki, Masanori; Kominami, Shushi; Mizunari, Takayuki; Kobayashi, Shiro; Katayama, Yasuo

    2014-01-01

    Central alveolar hypoventilation syndrome (CAHS) is a rare and potentially fatal condition. However, respiratory care for patients with CAHS caused by lateral medullary infarction (CAHS-LMI) remains an important unsolved problem. We describe 2 patients with CAHS-LMI and review the case reports for 17 previously described patients. Patient 1 was a 78-year-old man who was referred to our hospital because of dizziness. After admission, Wallenberg syndrome developed. Magnetic resonance imaging showed left LMI. He had hypercapnia and respiratory acidosis the next afternoon and temporarily received mechanical ventilation. A tracheotomy was performed on the 12th hospital day, and the patient was weaned from the ventilator on the 18th hospital day. Patient 2 was 72-year-old man who was referred to our hospital because of dizziness and gait disturbance. Wallenberg syndrome was diagnosed after admission, and magnetic resonance imaging showed right LMI. His consciousness deteriorated, and hypercapnia developed on the ninth hospital day. The patient received ventilatory support, and a tracheotomy was performed on the 12th hospital day. He was weaned from the ventilator by the 16th hospital day. Consistent with our findings, most previously reported cases of CAHS-LMI were initially associated with mild symptoms, which subsequently worsened. Five of the 19 patients (26.3%) died within 1 month after onset, and 7 patients (36.8%) died within 1 year. Tracheotomy was performed in 12 patients, 2 of whom died 1 month after onset (16.7%); another patient died of chronic renal failure after 2 years. Tracheotomy seemed to be an effective procedure in patients with CAHS-LMI. We speculate that tracheotomy assists alveolar ventilation by reducing dead space ventilation. Closure of the tracheotomy should, therefore, be avoided in patients with CAHS-LMI, even if respiratory status is good.

  3. Multi-step approach in a complex case of Cushing's syndrome and medullary thyroid carcinoma.

    PubMed

    Parenti, G; Nassi, R; Silvestri, S; Bianchi, S; Valeri, A; Manca, G; Mangiafico, S; Ammannati, F; Serio, M; Mannelli, M; Peri, A

    2006-02-01

    The diagnosis of Cushing's syndrome (CS) may sometimes be cumbersome. In particular, in ACTH-dependent CS it may be difficult to distinguish between the presence of an ACTH-secreting pituitary adenoma and ectopic ACTH and/or CRH secretion. In such instances, the etiology of CS may remain unknown despite extensive diagnostic workout, and the best therapeutic option for each patient has to be determined. We report here the case of a 54-yr-old man affected by ACTH-dependent CS in association with a left adrenal adenoma and medullary thyroid carcinoma (MTC). He presented with clinical features and laboratory indexes of hypercortisolism associated with elevated levels of calcitonin. Ectopic CS due to MTC was reported previously. In our case hypercortisolism persisted after surgical treatment of MTC. Thorough diagnostic assessment was performed, in order to define the aetiology of CS. He was subjected to basal and dynamic hormonal evaluation, including bilateral inferior petrosal sinus sampling. Extensive imaging evaluation was also performed. Overall, the laboratory data together with the results of radiological procedures suggested that CS might be due to inappropriate CRH secretion. However, the source of CRH secretion in this patient remained unknown. It was then decided to remove the left adenomatous adrenal gland. Cortisol level fell and has remained within the normal range nine months after surgery. This case well depicts the complexity of the diagnostic workout, which is needed sometimes to correctly diagnose and treat CS, and suggests that monolateral adrenalectomy may represent, at least temporarily, a reasonable therapeutic option in occult ACTH-dependent hypercortisolism.

  4. Oligodendrocytes and the control of myelination in vivo: new insights from the rat anterior medullary velum.

    PubMed

    Butt, A M; Berry, M

    2000-02-15

    The rat anterior medullary velum (AMV) is representative of the brain and spinal cord, overall, and provides an almost two-dimensional preparation for investigating axon-glial interactions in vivo. Here, we review some of our findings on axon-oligodendrocyte unit relations in our adult, development, and injury paradigms: (1) adult oligodendrocytes are phenotypically heterogeneous, conforming to Del Rio Hortega's types I-IV, whereby differences in oligodendrocyte morphology, metabolism, myelin sheath radial and longitudinal dimensions, and biochemistry correlate with the diameters of axons in the unit; (2) oligodendrocytes derive from a common premyelinating oligodendrocyte phenotype, and divergence of types I-IV is related to the age they emerge and the presumptive diameter of axons in the unit; (3) during myelination, axon-oligodendrocyte units progress through a sequence of maturation phases, related to axon contact, ensheathment, establishment of internodal myelin sheaths, and finally the radial growth and compaction of the myelin sheath; (4) we provide direct in vivo evidence that platelet-derived growth factor-AA (PDGF-AA), fibroblast growth factor (FGF-2), and insulin-like growth factor-I (IGF-I) differentially regulate these events, by injecting the growth factors into the cerebrospinal fluid of neonatal rat pups; (5) in lesioned adult AMV, transected central nervous system (CNS) axons regenerate through the putatively inhibitory environment of the glial scar, but remyelination by oligodendrocytes is incomplete, indicating that axon-oligodendrocyte interactions are defective; and (6) in the adult AMV, cells expressing the NG2 chondroitin sulphate have a presumptive adult oligodendrocyte progenitor antigenic phenotype, but are highly complex cells and send processes to contact axolemma at nodes of Ranvier, suggesting they subserve a specific perinodal function. Thus, axons and oligodendrocyte lineage cells form interdependent functional units, but

  5. Selective myelin defects in the anterior medullary velum of the taiep mutant rat.

    PubMed

    Song, J; Goetz, B D; Kirvell, S L; Butt, A M; Duncan, I D

    2001-01-01

    The taiep rat is a myelin mutant in which initial hypomyelination is followed by progressive demyelination of the CNS. An in vitro study suggests that accumulation of microtubules within oligodendrocytes is the cause of the taiep myelin defects (Song et al., 1999). In this article, we analyze microtubule accumulation in relation to taiep myelin defects in vivo in the anterior medullary velum (AMV), a CNS tissue that enables entire oligodendrocyte units to be resolved. Immunohistochemical analysis demonstrated notably high levels of beta-tubulin and the microtubule associated protein tau in the somata and processes of taiep oligodendrocytes. This was correlated with markedly reduced expression of the myelin proteins, proteolipid protein (PLP), myelin basic protein (MBP), 2',3 -cyclic nucleotide 3'-phosphodiesterase, and both large (L) and small (S) isoforms of myelin-associated glycoprotein (MAG). Moreover, PLP and L-MAG, which are dependent on the microtubule system for intracellular transport, accumulated in the perinuclear cytoplasm of the taiep oligodendrocyte. The myelin deficit was most marked in the area of the AMV populated by the small somata oligodendrocytes that have fine long processes that support numerous myelin sheaths of small diameter axons. Type III/IV oligodendrocytes, which have large somata and short processes that support a small number of myelin sheaths of large diameter axons, were also affected to a certain degree in compact myelin sheath formation. These results support the hypothesis that myelin loss and oligodendrocyte disruption in the taiep mutant result from a defect in the microtubule system that transports myelin components from the somata to the myelin sheath.

  6. The Effect of Experimental Fusarium Mycotoxicosis on Microbiota Diversity in Porcine Ascending Colon Contents

    PubMed Central

    Piotrowska, Małgorzata; Śliżewska, Katarzyna; Nowak, Adriana; Zielonka, Łukasz; Żakowska, Zofia; Gajęcka, Magdalena; Gajęcki, Maciej

    2014-01-01

    The objective of the study was to determine the effect of exposure of pigs to the Fusarium mycotoxins zearalenone (ZEN) and deoxynivalenol (DON), administered together and separately, on the colon microbiota. An experiment was conducted for 42 days on gilts, randomly assigned to four groups and administered either ZEN, DON, ZEN+DON, or a placebo. The number of aerobic mesophilic bacteria, yeasts, molds, anaerobic Clostridium perfringens, fecal streptococci, Enterobacteriaceae, Escherichia coli, and lactic acid bacteria (LAB) were determined in the contents of the ascending colon. The influence of mycotoxins on the functional diversity of the colonic microbiota was assessed using EcoPlate tests (Biolog). Analysis revealed the predominance of LAB in all groups of pigs. Zearalenone, administered separately and together with DON, was found to have an adverse effect on mesophilic aerobic bacteria, but only after long exposure to this mycotoxin. During the six weeks of the experiment, the concentration of C. perfringens, E. coli, and other bacteria in the family Enterobacteriaceae was most considerably reduced in the experimental groups exposed to zearalenone, both separately and together with DON. Mycotoxins also affected the functional biodiversity of microorganisms. Both Shannon’s diversity index and the number of catabolized substrates in Biolog plate (the R index) were much higher in the group subjected to mixed mycotoxicosis. PMID:25025709

  7. Restoration of the ascending reticular activating system compressed by hematoma in a stroke patient

    PubMed Central

    Jang, Sung Ho; Seo, Jeong Pyo

    2017-01-01

    Abstract Rationale: We report on restoration of the ascending reticular activating system (ARAS), compressed by an intracerebral hematoma and perihematomal edema following a stroke. The restoration of the ARAS was demonstrated by diffusion tensor tractography (DTT). Patient concerns: In a 60-year-old male, a brain MRI taken at 2 weeks after the surgery showed a hematoma and perihematomal edema in the left posterolateral pons and cerebellum, which were markedly resolved on a brain MRI after 5 weeks. Diagnoses: Intraventricular hemorrhage. Interventions: Navigation-guided stereotactic drainage of a hematoma in the left cerebellum, comprehensive rehabilitative therapy, including hypersomnia medication (modafinil), physical therapy, and occupational therapy. Outcomes: His hypersomnia improved significantly with rehabilitation, with no daytime hypersomnia beginning 3 weeks after the surgery. On 2-week DTT, neither the neural tract of the left lower dorsal or ventral ARAS were reconstructed, but these neural tracts were wellreconstructed on 5-week DTT. Lessons: In conclusion, restoration of nonreconstructed neural tracts of the lower ARAS with the resolution of the hematoma and perihematomal edema was demonstrated in a stroke patient, using DTT. PMID:28207526

  8. Dissolution of tonalitic enclaves in ascending hydrous granitic magmas: An experimental study

    NASA Astrophysics Data System (ADS)

    García-Moreno, O.; Castro, A.; Corretgé, L. G.; El-Hmidi, H.

    2006-07-01

    Dissolution of natural mafic magmatic enclaves in a hydrous leucogranitic synthetic melt has been tested experimentally. Results suggest that the mechanism of enclave dissolution is a potential hybridization process in granitic systems. Experiments performed in decompression, simulating ascending magmas, show interesting results: from 10 kbar to 4 kbar, for a given temperature, enhanced dissolution of the tonalitic enclave into the melt has been observed, compared with experiments at constant pressure. Furthermore, the composition of the melt changed to higher CaO, FeO and MgO contents. Dissolution textures on relict crystals from the tonalitic enclave were monitored. These results have implications for the generation of peraluminous monzogranites and granodiorites and an example for the Cabeza de Araya (Cáceres, Spain) from the "serie mixta" of the Iberian Massif is given. The tonalitic enclaves that are partially dissolved may be early or coeval intrusions into the granite magma or even into the source migmatitic area. Many mineralogical, geochemical and isotopic features of monzogranites (e.g.: reverse zoning in plagioclase, low Sr isotopic ratios) are accounted for by this mechanism of enclave dissolution during ascent and emplacement.

  9. Surgical treatment of aneurysms of the ascending aorta. Twelve years' experience in 66 patients.

    PubMed

    Markewitz, A; Weinhold, C; Kemkes, B M; Reichart, B; Hemmer, W; Klinner, W

    1986-10-01

    This study presents the results in 66 patients undergoing surgery for concomitant supracoronary vascular interposition and valve replacement carried out at the Department of Cardiac Surgery of the University of Munich, West-Germany, over a period of 12 years (from July 1, 1973 to June 30, 1985) using a technique similar to that described by Wheat. Forty-seven percent of the cases were true aneurysms and 20% chronic dissections. Thirty-three percent of patients had acute dissections. Early mortality was 16% in the total patient population, 9% in the group having true aneurysm and 32% in the group having acute dissection. No early death was observed in association with chronic dissections. The actuarial one-year survival rate in patients with true aneurysm or chronic dissection was 83.6%, and 54.1% in patients with acute dissection. The corresponding 4-year survival rates were 76.4% and 54.1%, respectively. The average improvement according to the New York Heart Association classification was 1.5 grades. These results confirm that the operative approach to ascending aortic aneurysms is superior to medical treatment, with the operative method involving vascular graft without concomitant aortic valve replacement as well as the method described by Wheat having both proved successful.

  10. Effects of bisacodyl on ascending colon emptying and overall colonic transit in healthy volunteers

    PubMed Central

    MANABE, N.; CREMONINI, F.; CAMILLERI, M.; SANDBORN, W. J.; BURTON, D. D.

    2010-01-01

    Background and Aim The mechanism of action of bisacodyl in the unprepared human colon is unclear. Our aim was to evaluate the effect of oral bisacodyl on the overall and regional colonic transit in humans. \\ Methods In a double-blind, randomized, placebo-controlled study of 25 healthy participants, effects of oral bisacodyl (5mg p.o. per day) and placebo on colonic transit were compared. Validated scintigraphy using 111In-charcoal delivered to the ileocolonic region in a delayed-release capsule was used to measure colonic transit. The primary transit endpoints, ascending colon emptying (AC) t1/2 and geometric center (GC) of colon isotope at 24 hours (overall transit), were compared (Wilcoxon rank sum test). Results There were significant treatment effects on AC t1/2, with the bisacodyl group demonstrating accelerated emptying [median 6.5 h, interquartile range (IQR) 5.0 – 8.0 h] relative to the placebo group [11.0 h (7.0 – 17.1)], P=0.03]. Numerical differences in colonic GC 24 hours [bisacodyl median 3.0 (2.2 – 3.8), placebo 4.0 (3.1 – 4.6)] were not significant (P=0.19). There were no significant differences observed in GC 4 hours. Conclusion Oral 5mg bisacodyl accelerates AC in the unprepared colon in healthy adults; this action may contribute to the drug’s efficacy in constipation. PMID:19678812

  11. Pointwise characterization of the elastic properties of planar soft tissues: application to ascending thoracic aneurysms.

    PubMed

    Davis, Frances M; Luo, Yuanming; Avril, Stéphane; Duprey, Ambroise; Lu, Jia

    2015-10-01

    In this manuscript, we present a combined experimental and computational technique that can identify the heterogeneous elastic properties of planar soft tissues. By combining inverse membrane analysis, digital image correlation, and bulge inflation tests, we are able to identify a tissue's mechanical properties locally. To show how the proposed method could be implemented, we quantified the heterogeneous material properties of a human ascending thoracic aortic aneurysm (ATAA). The ATAA was inflated at a constant rate using a bulge inflation device until it ruptured. Every 3 kPa images were taken using a stereo digital image correlation system. From the images, the three-dimensional displacement of the sample surface was determined. A deforming NURBS mesh was derived from the displacement data, and the local strains were computed. The wall stresses at each pressure increment were determined using inverse membrane analysis. The local material properties of the ATAA were then identified using the pointwise stress and strain data. To show that it is necessary to consider the heterogeneous distribution of the mechanical properties in the ATAA, three different forward finite element simulations using pointwise, elementwise, and homogeneous material properties were compared. The forward finite element predictions revealed that heterogeneous nature of the ATAA must be accounted for to accurately reproduce the stress-strain response.

  12. Injury of the lower ascending reticular activating system in patients with pontine hemorrhage

    PubMed Central

    Jang, Sung Ho; Yeo, Sang Seok

    2016-01-01

    Abstract Many studies have reported about injury of the ascending reticular activating system (ARAS) in patients with various brain pathologies, using diffusion tensor tractography (DTT); however, little is known about injury of the ARAS in patients with pontine hemorrhage. In this study, using DTT, we attempted to investigate injury of the lower ventral and dorsal ARAS in patients with pontine hemorrhage. Twenty-three consecutive patients with pontine hemorrhage and 14 control subjects were recruited into this study. The patients were classified into 2 subgroups on the basis of the preservation of arousal: subgroup A (14 patients)—intact arousal, subgroup B (9 patients)—impaired arousal. The lower ventral and dorsal ARAS between the pontine reticular formation with hypothalamus and thalamic intralaminar nucleus were reconstructed. Fractional anisotropy (FA), mean diffusivity (MD), and tract volume (TV) values were measured. The TVs of the lower ventral and dorsal ARAS were significantly lower in subgroup B than in the subgroup A and control group (P < 0.05). In terms of FA value, the lower dorsal ARAS were significantly lower in subgroup A and subgroup B than in the control group (P < 0.05). In conclusion, injury of the lower ventral and dorsal ARAS was demonstrated in patients with impaired arousal following pontine hemorrhage. We believe that analysis of the ARAS using DTT would be helpful in evaluation of patients with impaired consciousness after pontine hemorrhage. PMID:27977583

  13. Serotonin modulates the properties of ascending commissural interneurons in the neonatal mouse spinal cord.

    PubMed

    Zhong, Guisheng; Díaz-Ríos, Manuel; Harris-Warrick, Ronald M

    2006-03-01

    The interneuron populations that constitute the central pattern generator (CPG) for locomotion in the mammalian spinal cord are not well understood. We studied the properties of a set of commissural interneurons whose axons cross and ascend in the contralateral cord (aCINs) in the neonatal mouse. During N-methyl-D-aspartate (NMDA) and 5-HT-induced fictive locomotion, a majority of lumbar (L2) aCINs examined were rhythmically active; most of them fired in phase with the ipsilateral motoneuron pool, but some fired in phase with contralateral motoneurons. 5-HT plays a critical role in enabling the locomotor CPG to function. We found that 5-HT increased the excitability of aCINs by depolarizing the membrane potential, reducing the postspike afterhyperpolarization amplitude, broadening the action potential, and decreasing the action potential threshold. Serotonin had no significant effect on the input resistance and sag amplitude of aCINs. These results support the hypothesis that aCINs play important roles in coordinating left-right movements during fictive locomotion and thus may be component neurons in the locomotor CPG in neonatal mice.

  14. Hemodynamic effects of a counterpulsation device implanted on the ascending aorta in severe cardiogenic shock.

    PubMed

    Nanas, J N; Nanas, S N; Charitos, C E; Kontoyiannis, D; Poyiadjis, A D; Stamatopoulos, G; Melkaoui, A; Kokollis, G; Moulopoulos, S D

    1988-01-01

    A valveless, single orifice counterpulsation device (CD) with maximum stroke volume of 100 ml was implanted on the ascending aorta of nine dogs. Its pneumatic driver was gaited by the ECG to provide aortic diastolic augmentation, with a stroke volume of 60-70 ml. In the same animals a 20 ml intraaortic balloon (IAB) was placed into the descending aorta. An attempt was made to evaluate the effectiveness of the CD on severe cardiogenic shock and to compare its hemodynamic effects with those of the IABP. Severe cardiogenic shock was induced by coronary artery ligation, propranolol administration, and fluid infusion and was characterized by a LVEDP of 22.2 +/- 6.4 mmHg, ASP less than 70 mmHg and greater than or equal to 30 mmHg, and a reduction of CI by 71.7%. The CD had a significant beneficial effect in all measured parameters. The LVEDP decreased by a mean of 44.3% (P less than 0.001) below control value, and the AEDP by 60.2% (P less than 0.001). The PADA increased by 108.5% (P less than 0.001), and the CI by 155.8% (P less than 0.004). The IABP did not significantly change any of the hemodynamic variables. In conclusion, the CD has significant salutary hemodynamic effects in severe cardiogenic shock where IABP is ineffective.

  15. Atmospheric Airborne Pressure Measurements using the Oxygen A Band for the ASCENDS Mission

    NASA Astrophysics Data System (ADS)

    Riris, H.; Rodriguez, M.

    2014-12-01

    We report on an airborne demonstration of atmospheric oxygen optical depth measurements with an Integrated Path Differential Absorption (IPDA) lidar using a fiber-based laser system and a photon counting detector. Accurate knowledge of atmospheric temperature and pressure is required for NASA's Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS) space mission, and climate modeling studies. The lidar uses a doubled Erbium Doped Fiber amplifier and single photon counting detector to measure oxygen absorption at 765 nm. Our approach uses a sequence of laser pulses at increasing wavelengths that sample a pair of absorption lines in the Oxygen A-band at 764.7 nm. The O2 lines were selected after careful spectroscopic analysis to minimize the O2 line temperature dependence and the availability of the transmitter and receiver technology to maximize transmitter power, doubling efficiency, and detector sensitivity. We compare our 2013 and 2014 Oxygen IPDA lidar measurements and evaluate the impact of receiver dynamic range, transmitter stability and signal to noise ratio on the differential optical depth measurements.

  16. Hypersomnia due to injury of the ventral ascending reticular activating system following cerebellar herniation

    PubMed Central

    Jang, Sung Ho; Chang, Chul Hoon; Jung, Young Jin; Kwon, Hyeok Gyu

    2017-01-01

    Abstract Rationale: We report on a patient with hypersomnia who showed injury of the lower ascending reticular activating system (ARAS) following cerebellar herniation due to a cerebellar infarct, detected on diffusion tensor tractography (DTT). Patient concerns: A 53-year-old male patient was diagnosed as a left cerebellar infarct, and underwent decompressive suboccipital craniectomy due to brain edema at 2 days after the onset of a cerebellar infarct. Three weeks after onset when the patient started rehabilitation, he showed hypersomnia without impairment of consciousness; he fell asleep most of daytime without external stimulation and showed an abnormal score on the Epworth Sleepiness Scale: 15 (full score: 24, cut off for hypersomnia: 10). Diagnoses and Outcomes: On 3-week DTT, narrowing of the upper portion of the lower ventral ARAS between the pontine reticular formation and the hypothalamus was observed on both sides. In addition, partial tearing was observed in the middle portion of the right lower ventral ARAS. Lessons: In conclusion, we found injury of the lower ventral ARAS in a patient with hypersomnia following cerebellar herniation due to a cerebellar infarct. PMID:28072702

  17. A novel paradigm for urban environment characterization using ascending and descending TerraSAR-X data

    NASA Astrophysics Data System (ADS)

    Angiuli, E.; Trianni, G.; Gamba, P.

    2011-11-01

    The new Very High Resolution radar satellites, with a spatial resolution up to 1 meter, give a unique opportunity in the context of urban applications. This paper presents an approach for automatic detection of built-up areas based on the analysis of single-polarized TerraSAR-X images. The proposed methodology includes a specific preprocessing of the SAR data and an automated image analysis procedure. The preprocessing aims at providing a multi-resolution texture layer based on the analysis of local speckle characteristics to automatically extract settlements. The technique is tested on 2 TerraSAR-X images acquired over the city of Pavia, northern Italy, in February3 2008. The overall accuracies between 78% and 85% for the derived city footprints demonstrate the high potential of the proposed analysis for built up areas detection. In addition, the joint use of both acquisitions allow to reach a total accuracy of 89%. Although the methodology needs to be further tested on different case studies, the investigation demonstrates the feasibility and the utility of the combined use of ascending and descending SAR intensities data for complete urban footprint extraction.

  18. Identification of vessel wall degradation in ascending thoracic aortic aneurysms with OCT

    PubMed Central

    Real, Eusebio; Val-Bernal, José Fernando; Revuelta, José M.; Pontón, Alejandro; Díez, Marta Calvo; Mayorga, Marta; López-Higuera, José M.; Conde, Olga M.

    2014-01-01

    Degradation of the wall of human ascending thoracic aorta has been assessed through Optical Coherence Tomography (OCT). OCT images of the media layer of the aortic wall exhibit micro-structure degradation in case of diseased aortas from aneurysmal vessels. The OCT indicator of degradation depends on the dimension of areas of the media layer where backscattered reflectivity becomes smaller due to a disorder on the morphology of elastin, collagen and smooth muscle cells (SMCs). Efficient pre-processing of the OCT images is required to accurately extract the dimension of degraded areas after an optimized thresholding procedure. OCT results have been validated against conventional histological analysis. The OCT qualitative assessment has achieved a pair sensitivity-specificity of 100%-91.6% in low-high degradation discrimination when a threshold of 4965.88µm2 is selected. This threshold suggests to have physiological meaning. The OCT quantitative evaluation of degradation achieves a correlation of 0.736 between the OCT indicator and the histological score. This in-vitro study can be transferred to the clinical scenario to provide an intraoperative assessment tool to guide cardiovascular surgeons in open repair interventions. PMID:25426332

  19. H2O-Silicate Microphysics in Ascending Volcanic Plumes on Mars

    NASA Technical Reports Server (NTRS)

    Zent, A. P.

    2003-01-01

    Physical adsorption of water vapor plays a much more significant role in eruptive plume energetics on Mars than on Earth. The total surface area in martian plumes is likely comparable to terrestrial ash, while the erupting magma and ambient atmosphere are drier. Plumes cool rapidly during ascent, and a limited population of H2O molecules find adsorption sites to be increasingly stable. Release of latent heat of condensation and the onset of moist convection are diminished, delayed, or even prevented by adsorptive interaction We have developed a 5-component numerical model of the behavior of water in eruptive plumes under Mars-like conditions. We have used the model to study the fate of both juvenile and ambient atmospheric water in the eruption column. Here we investigate the adsorptive interaction of water and silicates as they effect plume dynamics and the partitioning and distribution of H2O to the martian environment. Our focus is on the role of adsorption in scavenging H2O from the ascending eruption column, and the possibility that adsorptive scavenging depresses the vapor pressure in the column below the level considered in most eruptive models.

  20. Study of seismic activity during the ascending and descending phases of solar activity

    NASA Astrophysics Data System (ADS)

    Sukma, Indriani; Abidin, Zamri Zainal

    2016-12-01

    The study of the solar cycle and geomagnetic index associated with the seismic activity from the year 1901 to the end of 2015 has been done for an area that covers the majority of China and its bordering countries. Data of sunspot number, solar wind speed, daily storm time index and earthquake number are collected from NOAA, NASA, WDC, OMNI and USGS databases and websites. The earthquakes are classified into small (M < 5) and large (M ≥ 5) magnitudes (in Richter scale). We investigated the variation of earthquake activities with the geomagnetic storm index due to the solar wind. We focused on their variation in the ascending and descending phases of solar cycle. From our study, we conclude that there is a correlation between the phases' geomagnetic index and solar wind speed. We have also suggested that there is a certain degree of correlation between solar activity and seismicity in these phases. For every solar cycle, we find that there is a trend for earthquakes to occur in greater numbers during the descending phase. This can be explained by the increment in the solar wind speed and geomagnetic storm index during this phase.

  1. A molecular map of G protein alpha chains in microdissected rat nephron segments.

    PubMed Central

    Senkfor, S I; Johnson, G L; Berl, T

    1993-01-01

    Membrane-associated guanine nucleotide binding proteins regulate many receptor-mediated signals. Heterogeneity of biochemical and functional properties in nephron segments could be due to differences in G protein expression. To ascertain whether such heterogeneity of G proteins is present in various nephron segments, this study examines the distribution and relative abundance of G protein alpha chains in microdissected medullary thick ascending limb, cortical collecting tubules, outer medullary collecting tubules, proximal inner medullary tubules, and distal inner medullary tubules. Reverse transcription and polymerase chain reactions were employed using oligonucleotides encoding highly conserved regions of all known alpha chains. The cDNA was sequenced for alpha chain identification. The alpha i2 versus alpha s distribution was different in the outer medullary collecting tubules, when compared with the medullary thick ascending limb (P < 0.001) or the cortical collecting tubule, the proximal inner medullary tubules, and the distal inner medullary tubules (P < 0.05). These latter four segments did not significantly differ from each other. A similar analysis was applied to the frequently used line of kidney cells, LLC-PK1, whose exact cellular origin remains unclear. Interestingly, we detected both alpha i2 and alpha i3, while only alpha i2 was detected in the rat distal nephron. No alpha o or alpha z reverse transcription PCR products were detected. In contrast alpha 11 and alpha 14 members of the more recently described alpha q family were detected in the outer medullary collecting tubules and the proximal inner medullary tubules, respectively. We conclude that the majority of nephron segments have a relatively constant distribution of G protein alpha chains. Images PMID:8349818

  2. Purinergic signalling contributes to chemoreception in the retrotrapezoid nucleus but not the nucleus of the solitary tract or medullary raphe

    PubMed Central

    Sobrinho, Cleyton R; Wenker, Ian C; Poss, Erin M; Takakura, Ana C; Moreira, Thiago S; Mulkey, Daniel K

    2014-01-01

    Several brain regions are thought to function as important sites of chemoreception including the nucleus of the solitary tract (NTS), medullary raphe and retrotrapezoid nucleus (RTN). In the RTN, mechanisms of chemoreception involve direct H+-mediated activation of chemosensitive neurons and indirect modulation of chemosensitive neurons by purinergic signalling. Evidence suggests that RTN astrocytes are the source of CO2-evoked ATP release. However, it is not clear whether purinergic signalling also influences CO2/H+ responsiveness of other putative chemoreceptors. The goals of this study are to determine if CO2/H+-sensitive neurons in the NTS and medullary raphe respond to ATP, and whether purinergic signalling in these regions influences CO2 responsiveness in vitro and in vivo. In brain slices, cell-attached recordings of membrane potential show that CO2/H+-sensitive NTS neurons are activated by focal ATP application; however, purinergic P2-receptor blockade did not affect their CO2/H+ responsiveness. CO2/H+-sensitive raphe neurons were unaffected by ATP or P2-receptor blockade. In vivo, ATP injection into the NTS increased cardiorespiratory activity; however, injection of a P2-receptor blocker into this region had no effect on baseline breathing or CO2/H+ responsiveness. Injections of ATP or a P2-receptor blocker into the medullary raphe had no effect on cardiorespiratory activity or the chemoreflex. As a positive control we confirmed that ATP injection into the RTN increased breathing and blood pressure by a P2-receptor-dependent mechanism. These results suggest that purinergic signalling is a unique feature of RTN chemoreception. PMID:24445316

  3. A rare case of concomitant sicca keratopathy and ipsilateral central facial palsy in Wallenberg’s dorsolateral medullary syndrome

    PubMed Central

    De Bruyn, Deborah; Van Aken, Elisabeth; Herman, Kristien

    2017-01-01

    Objective: To describe a patient with a right-sided supranuclear facial palsy and concomitant sicca keratopathy of the right eye following right-sided dorsolateral medullary infarction. Methods: Our patient underwent a complete ophthalmologic and neurologic examination including biomicroscopy, fundus examination, cranial nerve examination, Shirmer I test, and magnetic resonance imaging of the brain. Results: A 61-year-old woman presented in emergency with a central facial nerve palsy on the right side and truncal ataxia. Neurologic assessment revealed a concurrent dysphagia, dysarthria, hypoesthesia of the right face, and weakness of the right upper limb. Magnetic resonance imaging of the brain showed an old left-sided cerebellar infarction, but a recent ischemic infarction at the level of the right dorsolateral medulla oblongata was the cause of our patient’s current problems. One month after diagnosis of the right-sided dorsolateral medullary syndrome, there were complaints of ocular irritation and a diminished visual acuity in the right eye. Biomicroscopy showed a sicca keratopathy with nearly complete absence of tear secretion on the Shirmer I test, but with normal eye closure and preserved corneal reflexes and sensitivity. Conclusion: A dorsolateral medullary syndrome can have a variable expression in symptomatology. Our case is special because of the combination of an ipsilateral supranuclear facial palsy with normal upper facial muscle function together with an ipsilateral sicca keratopathy as a result of a nearly absent tear secretion. We hypothesized that the mechanism underlying the patient’s sicca keratopathy ipsilateral to the supranuclear facial palsy involved the superior salivatory nucleus, which is situated in the caudal pons inferiorly of the motor facial nucleus and is most probably affected by a superior extension of the infarcted area in the right medulla oblongata. PMID:28293537

  4. 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography for Other Thyroid Cancers: Medullary, Anaplastic, Lymphoma and So Forth

    PubMed Central

    Araz, Mine; Çayır, Derya

    2017-01-01

    Positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose (FDG) is used in staging, restaging, and evaluation of therapy response in many cancers as well as differentiated thyroid carcinomas especially in non-iodine avid variants. Its potential in less frequent thyroid tumors like medullary, anaplastic thyroid cancers, thyroid lymphoma and metastatic tumors of the thyroid however, is not well established yet. The aim of this review is to provide an overview on the recent applications and indications of 18F-FDG PET/CT in these tumors and to focus on the controversies in the clinical setting. PMID:28291004

  5. A study of the dimensions and taper angles of the medullary canals of the proximal and middle phalanges.

    PubMed

    McArthur, P A; Cutts, A; Milner, R H; Johnson, G R

    1998-02-01

    The morphology and dimensions of the medullary canals of the proximal and middle phalanges have been studied with particular interest shown to the angle of taper of these canals. Measurements of 50 cadaveric fingers were taken from computer aided tomographic images using AutoCAD software. Tangents were fitted to the inner cortices in two orthogonal planes and the angles between them were measured. The angles of canal taper in the proximal phalanx were remarkably similar for each digit. This was also true for the middle phalanx of the index, middle and ring fingers but the taper of the middle phalanx of the little finger was found to be different.

  6. Acute coronary syndrome: a rare case of multiple endocrine neoplasia syndromes with pheochromocytoma and medullary thyroid carcinoma

    PubMed Central

    Maloberti, Alessadro; Meani, Paolo; Pirola, Roberto; Varrenti, Marisa; Boniardi, Marco; De Biase, Anna Maria; Vallerio, Paola; Bonacina, Edgardo; Mancia, Giuseppe; Loli, Paola; Giannattasio, Cristina

    2015-01-01

    Pheochromocytoma is a tumor arising from neuroectodermal chromaffin tissues in the adrenal gland or extra-adrenal paraganglia (paragangliomas). The prevalence of the tumor is 0.1%-0.6% in the hypertensive population, of which 10%-20% are malignant. Pheochromocytoma produces, stores, and secretes catecholamines, as well as leads to hypertensive crisis, arrhythmia, angina, and acute myocardial infarction without coronary artery diseases. We report a case of acute coronary syndrome (ACS) with a final diagnosis of multiple endocrine neoplasia with pheochromocytoma and medullary thyroid carcinoma (MTC). PMID:26487970

  7. Acute coronary syndrome: a rare case of multiple endocrine neoplasia syndromes with pheochromocytoma and medullary thyroid carcinoma.

    PubMed

    Maloberti, Alessadro; Meani, Paolo; Pirola, Roberto; Varrenti, Marisa; Boniardi, Marco; De Biase, Anna Maria; Vallerio, Paola; Bonacina, Edgardo; Mancia, Giuseppe; Loli, Paola; Giannattasio, Cristina

    2015-09-01

    Pheochromocytoma is a tumor arising from neuroectodermal chromaffin tissues in the adrenal gland or extra-adrenal paraganglia (paragangliomas). The prevalence of the tumor is 0.1%-0.6% in the hypertensive population, of which 10%-20% are malignant. Pheochromocytoma produces, stores, and secretes catecholamines, as well as leads to hypertensive crisis, arrhythmia, angina, and acute myocardial infarction without coronary artery diseases. We report a case of acute coronary syndrome (ACS) with a final diagnosis of multiple endocrine neoplasia with pheochromocytoma and medullary thyroid carcinoma (MTC).

  8. Gauge Measures Thicknesses Of Blankets

    NASA Technical Reports Server (NTRS)

    Hagen, George R.; Yoshino, Stanley Y.

    1991-01-01

    Tool makes highly repeatable measurements of thickness of penetrable blanket insulation. Includes commercial holder for replaceable knife blades, which holds needle instead of knife. Needle penetrates blanket to establish reference plane. Ballasted slider applies fixed preload to blanket. Technician reads thickness value on scale.

  9. Measuring Thicknesses of Wastewater Films

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Davenport, R. J.

    1987-01-01

    Sensor determines when thickness of film of electrically conductive wastewater on rotating evaporator drum exceeds preset value. Sensor simple electrical probe that makes contact with liquid surface. Made of materials resistant to chemicals in liquid. Mounted on shaft in rotating cylinder, liquid-thickness sensor extends toward cylinder wall so tip almost touches. Sensor body accommodates probe measuring temperature of evaporated water in cylinder.

  10. Rapidly Progressive Renal Dysfunction in Two Elderly Patients with Renal Enlargement and Medullary Cystic Kidney Disease-like Acute Tubulointerstitial Injury

    PubMed Central

    Kawamoto, Shinya; Koda, Ryo; Yoshino, Atsunori; Takeda, Tetsuro; Ueda, Yoshihiko

    2016-01-01

    Medullary cystic kidney disease (MCKD) is a hereditary disease associated with bilateral medullary polycysts and interstitial fibrosis. MCKD is typically associated with slowly progressive renal dysfunction. We herein report two rare elderly cases with enlarged kidneys and rapidly progressive renal dysfunction without myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA), PR3-ANCA, or anti-glomerular basement membrane (GBM) antibodies. Renal biopsies revealed extensive tubular dilatation and atrophy with interstitial fibrosis consistent with MCKD. Both patients began hemodialysis therapy a few months later. Our cases suggest a MCKD subgroup among elderly patients with an undefined genetic background, rapidly progressive renal dysfunction, and enlarged kidneys. PMID:27746439

  11. Laser Sounder for Measuring Atmospheric CO2 Concentrations: Progress Toward Ascends

    NASA Technical Reports Server (NTRS)

    Abshire, J. B.; Kawa, S. R.; Riris, H.; Allan, G. R.; Sun, X.; Stephen, M. A.; Wilson, E.; Burris, J. F.; Mao, J.

    2008-01-01

    The next generation of space-based, active remote sensing instruments for measurement of tropospheric CO2 promises a capability to quantify global carbon sources and sinks at regional scales. Active (laser) methods will extend CO2 measurement coverage in time, space, and perhaps precision such that the underlying mechanisms for carbon exchange at the surface can be understood with .sufficient detail to confidently project the future of carbon-climate interaction and the influence of remediative policy actions. The recent Decadal Survey for Earth Science by the US National Research Council has recommended such a mission called the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) for launch in 2013-2016. We have been developing a laser technique for measurement of tropospheric CO2 for a number of years. Our immediate goal is to develop and demonstrate the method and instrument technology that will permit measurements of the CO2 column abundance over a horizontal path and from aircraft at the few-ppmv level. Our longer-term goal is to demonstrate the required capabilities of the technique, develop a space mission approach, and design the instrument for an ASCENDS-type mission. Our approach is to use a dual channel laser absorption spectrometer (i.e., differential absorption in altimeter mode), which continuously measures from a near-polar circular orbit. We use several co-aligned tunable fiber laser transmitters allowing simultaneous measurement of the absorption from a CO2 line in the 1570 nm band, O2 extinction in the oxygen A-band (near 765 nm), and aerosol backscatter in the same measurement path. We measure the energy of the laser echoes at nadir reflected from land and water surfaces, day and night. The lasers have spectral widths much narrower than the gas absorption lines and are turned on and off the selected CO2 and O2 lines at kHz rates. The gas extinction and column densities for the CO2 and O2 gases are estimated from the ratio of

  12. Pulsed Lidar for Measurement of C02 Concentrations for the ASCENDS Mission - Update

    NASA Technical Reports Server (NTRS)

    Abshire, James; Riris, Haris; Allan, Graham; Sun, Xiaoli; Mao, Jianping; Weaver, Clark; Yu, Anthony; Chen, Jeffrey; Rodriquez, Michael; Kawa, S. Randy

    2011-01-01

    We have been developing a laser-based sounding technique for the remote measurement of the tropospheric CO2 concentrations from orbit for NASA is ASCENDS mission. The mission's goals are to provide measurements of tropospheric CO2 abundance with global-coverage, a few hundred km spatial and monthly temporal resolution. These are needed to better understand CO2 fluxes and the processes that regulate CO2 storage by the land and oceans. For the lIP, we are developing and demonstrating the lidar techniques and key lidar technology that will permit measurements of the CO2 column abundance in the lower troposphere from aircraft. Our final goal is to demonstrate the key capabilities needed for a space lidar and mission approach for the ASCENDS mission. We use a pulsed lidar technique, which is much less sensitive to errors from cloud and atmospheric scattering and to noise from solar background. It allows continuous measurements of CO2 mixing ratio in the lower troposphere during day and night. Our approach uses the 1570nm CO2 band and a two-wavelength laser absorption spectrometer, which continuously measures at nadir from a circular polar orbit. It directs the narrow co-aligned laser beams from the instrument's lasers toward nadir, and measures the energy of the laser echoes reflected from land and water surfaces. It uses a pair of tunable laser transmitters, which allowing measurement of the extinction from a single selected CO2 absorption line in the 1570 nm band and from a line pair in the Oxygen A-band near 765 nm. These regions have temperature insensitive absorption lines are free from interference from other gases. The lasers pulse at 10KHz, use tunable diode seed lasers followed by laser amplifiers, and have MHz spectral widths. During the measurement the lasers are stepped across the selected lines at a kHz rate. The receiver uses a 1-m class telescope and photon sensitive detectors and measures the background light and energies of the laser echoes from the

  13. Valve-sparing replacement of the ascending aorta and aortic arch in a child with Loeys-Dietz syndrome.

    PubMed

    Ozker, Emre; Vuran, Can; Saritas, Bülent; Türköz, Riza

    2012-05-01

    We describe a successful surgical treatment in a 2.5-year old boy with Loeys-Dietz syndrome, in whom we performed aortic arch and ascending aorta replacement with a valve-sparing operation (VSO) of the aortic root because of significant aortic insufficiency and dilation of the aortic root. We believe that VSO is ideal for treating young patients with aortic root aneurysm with normal or minimally diseased aortic cusps to avoid the disadvantages of prosthetic valve replacements.

  14. Analysis of Factors Driving Incident and Ascending Infection and the Role of Serum Antibody in Chlamydia trachomatis Genital Tract Infection

    PubMed Central

    Russell, Ali N.; Zheng, Xiaojing; O'Connell, Catherine M.; Taylor, Brandie D.; Wiesenfeld, Harold C.; Hillier, Sharon L.; Zhong, Wujuan; Darville, Toni

    2016-01-01

    Background. Chlamydia trachomatis genital tract infection is a major cause of female reproductive morbidity. Risk factors for ascending infection are unknown, and the role for antibody in protection is not well established. Methods. We recruited 225 women from urban outpatient clinics and followed them for a median of 12 months. We performed a cross-sectional analysis of serum anti-chlamydial immunoglobulin G (IgG), behavioral factors, and microbiological factors associated with endometrial infection at enrollment, and a longitudinal analysis of factors associated with incident infection. Results. Oral contraceptives (adjusted relative risk [RR], 2.02 [95% confidence interval {CI}, 1.38–2.97]) and gonorrhea (adjusted RR, 1.66 [95% CI, 1.07–2.60]) were associated with endometrial infection. Gonorrhea (adjusted hazard ratio [HR], 3.09 [95% CI, 1.41–6.78]), cervical infection at enrollment (adjusted HR, 2.33 [95% CI, 1.07–5.11]), and exposure to uncircumcised partners (adjusted HR, 2.65 [95% CI, 1.21–5.82]) or infected partners (adjusted HR, 4.99 [95% CI, 2.66–9.39]) significantly increased the risk of incident infection. Seropositivity was associated with a reduced cervical burden (P < .05) but no differences in rates of ascending infection (adjusted RR, 1.24 [95% CI, .71–2.19]) or incident infection (adjusted HR, 0.94 [95% CI, .52–1.69]). Conclusions. Serum anti-chlamydial IgG is not associated with a lowered rate of ascending or repeat infection. Identification of factors associated with ascending infection and increased risk of incident infection provide guidance for targeted screening of women at increased risk for sequelae. PMID:26347571

  15. Pharmacokinetics of EDP-420 after Ascending Single Oral Doses in Healthy Adult Volunteers▿

    PubMed Central

    Jiang, Li-Juan; Wang, Michelle; Or, Yat Sun

    2009-01-01

    EDP-420 (EP-013420, S-013420) is a first-in-class bicyclolide (bridged bicyclic macrolide) currently in clinical development for the treatment of respiratory tract infections. It has good preclinical pharmacokinetic properties across multiple species and potent in vitro and in vivo activity against respiratory tract infection pathogens, including Haemophilus influenzae, atypical organisms (e.g., Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila), and multidrug-resistant streptococci. The safety, tolerability, and pharmacokinetics of an orally administered EDP-420 suspension in 40 healthy adult subjects were assessed in a randomized, double-blind, placebo-controlled, ascending single-dose study. Eligible subjects were sequentially randomized into one of five study groups (i.e., 100-, 200-, 400-, 800-, or 1,200-mg dosing groups) consisting of eight subjects (six active and two placebo) each. EDP-420 was well tolerated. There were no serious adverse events reported, nor were there any dose-limiting clinical or laboratory adverse events reported. EDP-420 was rapidly absorbed after a single oral dose. The mean plasma terminal half-life ranged from 15.6 to 20.1 h with low clearance. At the 400-mg dose, the area under the curve was 14.4 μg·h/ml, which well exceeded the required area under the concentration-time curve to cover common respiratory tract infection pathogens based on preclinical pharmacokinetic/pharmacodynamic modeling. The long half-life and high systemic exposure of EDP-420 support once-daily dosing and may allow for shorter treatment durations compared to other macrolide antibiotics. Based on its human pharmacokinetic profiles, taken together with its in vitro/in vivo activity against common respiratory pathogens, EDP-420 warrants efficacy trials for the treatment of respiratory tract infections. PMID:19223626

  16. Pharmacokinetics of cefetamet pivoxil (Ro 15-8075) with ascending oral doses in normal healthy volunteers.

    PubMed Central

    Tam, Y K; Kneer, J; Dubach, U C; Stoeckel, K

    1989-01-01

    The pharmacokinetics of cefetamet pivoxil during administration of ascending oral doses were studied in 16 male normal healthy volunteers (age, 24.5 +/- 2.1 years; weight, 73.5 +/- 8.5 kg). The subjects were randomly assigned to four oral treatments of 500, 1,000, 1,500, and 2,000 mg of cefetamet pivoxil according to a four-by-four Latin square design. After an overnight fast, the drug was administered 10 min after a standard breakfast. It was found that both the rate and extent of prodrug absorption, measured as cefetamet adsorption, were reduced with increasing doses. The time to maximum concentration of cefetamet in serum was delayed from 4.00 +/- 0.81 to 4.88 +/- 0.96 h (P less than 0.05) when the dose of cefetamet pivoxil was increased from 500 to 2,000 mg. The dose-normalized values of area under the curve from 0 h to infinity for cefetamet and fraction of dose excreted as cefetamet were reduced by averages of 10.3 and 12.5%, respectively, over the dose range studied (P less than 0.05). The changes in rate and extent of prodrug absorption are thought to be the main factors contributing to the nonlinear relationship between maximum concentration in serum and dose. The change in absorption characteristics of cefetamet pivoxil with dose is, however, expected to have few clinical consequences because the magnitudes of these changes are comparable with their respective intragroup variations. PMID:2764545

  17. African Equatorial GPS Scintillations during the Minimum and Ascending Phases of Solar Cycle 24

    NASA Astrophysics Data System (ADS)

    Akala, Andrew; Groves, K. M.; Amaeshi, Larry; Idolor, Raphael; Okoro, Ekemini; Carrano, Charles; Bridgwood, Christopher; Baki, Paul; Dujanga, Florence; Doherty, Patricia

    Abstract This study characterizes African equatorial scintillations at L-band frequency during the minimum and ascending phases of solar cycle 24. Three years’ (2009-2011) of amplitude scintillation data from three African equatorial GPS stations namely; Lagos (3.48oN, 3.27oE, mag. lat: 3.04oS), Nigeria; Nairobi (1.30oS, 36.80oE, mag. lat: 8.03oS), Kenya; and Kampala (0.30oN, 32.50oE, mag. lat: 9.26oS), Uganda were used for the investigation. We grouped the data on daily, monthly, seasonal, and yearly scales at three levels of scintillation (weak (0.3≤S4<0.4), moderate (0.4≤S4<0.7), and intense (S4≥0.7)), and adopted three data cut-off criteria. Scintillations exhibit daily trend of occurrence during the hours of 1900 LT-0200 LT, with higher levels being localized within the hours of 2000-2300 LT. Generally, highest scintillation occurrences were recorded during the equinoxes, and the trend increased with solar activity. Specifically, scintillations were almost absent during June Solstices of the period under investigation, and it appears as if January is a non-scintillation month over equatorial Africa. On a scintillation active day, the number of satellites available to the receiver’s view reduces as the duration of observation reduces. These results may support the development of future models that could provide real-time predictability of African equatorial scintillations, with a view to supporting the implementation of GNSS-based navigation in Africa.

  18. The energy expenditure of non-weight bearing crutch walking on the level and ascending stairs.

    PubMed

    Moran, Jonathan; Murphy, Alexandra; Murphy, David; Austin, Andy; Moran, Danielle; Cronin, Caitriona; Guinan, Emer; Hussey, Juliette

    2015-06-01

    Crutches are commonly prescribed to patients with lower limb dysfunction during rehabilitation to assist with mobility. The aim of this study was to determine the energy expenditure for non-weight bearing crutch walking on level ground and ascending stairs at a self selected speed in a healthy adult population. Thirty-one healthy male and female adults (mean±SD: age 21.6±1.2 years; height 170.8±10.8 cm; weight 70.8±11.4 kg) mobilised non-weight bearing with elbow crutches along a 30 m corridor and (with one crutch) up a flight of 13 stairs. Energy expenditure for each activity was measured by indirect calorimetry using the COSMED K4b(2) portable ergospirometry system. The established VO2 values were 16.4ml/kg/min for crutch walking on level ground and 17.85 ml/kg/min for stair climbing. Non-weight bearing crutch walking at a self selected speed on the level ground and up a flight of stairs resulted in a MET value of 4.57 and 5.06 respectively. The mean heart rate (HR) for crutch walking along the flat was 117.06±20.54 beats per minute (bpm), while the mean HR for ambulating upstairs with crutches was 113.91±19.32 bpm. The increased energy demands of non-weight bearing crutch walking should be considered by physical therapists when instructing patients on crutch use. Further investigation to determine the implications of these results in populations with chronic disease is warranted.

  19. Pharmacokinetics of clarithromycin, a new macrolide, after single ascending oral doses.

    PubMed Central

    Chu, S Y; Sennello, L T; Bunnell, S T; Varga, L L; Wilson, D S; Sonders, R C

    1992-01-01

    The pharmacokinetics and safety of single ascending doses of clarithromycin (6-0-methylerythromycin A) were assessed in a placebo-controlled, double-blind, randomized trial with 39 healthy male volunteers. Subjects were randomized to receive single doses of either placebo or 100, 200, 400, 600, 800, or 1,200 mg of clarithromycin. Blood and urine collections were performed over the 24 h following administration of the test preparation. Biological specimens were analyzed for clarithromycin and 14(R)-hydroxyclarithromycin content by a high-performance liquid chromatographic technique. The pharmacokinetics of clarithromycin appeared to be dose dependent, with terminal disposition half-life ranging from 2.3 to 6.0 h and mean +/- standard deviation area under the concentration-versus-time curve from time 0 to infinity for plasma ranging from 1.67 +/- 0.48 to 3.72 +/- 1.26 mg/liter.h per 100-mg dose over the 100- to 1,200-mg dose range. Similar dose dependency was noted in the pharmacokinetics of the 14(R)-hydroxy metabolite. Mean urinary excretion of clarithromycin and its 14(R)-hydroxy metabolite ranged from 11.5 to 17.5% and 5.3 to 8.8% of the administered dose, respectively. Urinary excretion data and plasma metabolite/parent compound concentration ratio data suggested that capacity-limited formation of the active metabolite may account, at least in part, for the nonlinear pharmacokinetics of clarithromycin. No substantive dose-related trend was observed for the renal clearance of either compound. There were no clinically significant drug-related alterations in laboratory and nonlaboratory safety parameters. In addition, there was no significant difference between placebo and clarithromycin recipients in the incidence or severity of adverse events. Clarithromycin appears to be safe and well tolerated. PMID:1489187

  20. Improving Hemostasis during Replacement of the Ascending Aorta and Aortic Valve with a Composite Graft

    PubMed Central

    Pratali, Stefano; Milano, Aldo; Codecasa, Riccardo; De Carlo, Marco; Borzoni, Giancarlo; Bortolotti, Uberto

    2000-01-01

    The use of a composite graft is an established treatment for patients with aortic valve disease and ascending aortic aneurysms. Since bleeding from suture lines is a potential complication of this procedure, we modified the technique and evaluated the effect on hemostasis. From January 1994 through December 1998, 35 patients underwent composite aortic graft replacement for chronic aortic disease. In the first 16 patients (Group 1), we used the standard open technique, with excision of the aortic aneurysm and anastomosis of aortic buttons containing the coronary ostia to the vascular graft. In the next 19 patients (Group 2), we modified the technique by placing an additional suture at the proximal graft anastomosis and harvesting large coronary buttons that were then attached to the graft by an “endo-button” buttress method. There were no operative deaths; the actuarial survival rate at 36 months was 92% ± 5%. Between groups 1 and 2, a significant difference was found in postoperative bleeding (1,052 ± 433 mL vs 806 ± 257 mL, respectively; p = 0.02) and in number of blood transfusions required (2.1 ± 2.0 units vs 0.4 ± 0.7 units, respectively; p = 0.002). Multivariate analysis showed that the surgical technique used in Group 1 was the only independent risk factor for postoperative bleeding of 1,000 mL or more (p = 0.01) and for transfusion requirements of 3 or more units of blood (p = 0.004). Composite aortic valve and root replacement can be accomplished with excellent results. Technical modifications may reduce bleeding complications and related morbidity significantly. PMID:11093407

  1. Surgical management of patients with the Marfan syndrome and dilatation of the ascending aorta.

    PubMed

    McDonald, G R; Schaff, H V; Pyeritz, R E; McKusick, V A; Gott, V L

    1981-02-01

    Until recently, surgical correction of Marfan defects of the aortic root has been undertaken with some hesitancy because of the high perioperative risk. The Division of Medical Genetics at Johns Hopkins follows about 300 patients with the Marfan syndrome, and during the past 8 years 13 of these were referred to the senior author (V.L.G.) for aortic valve replacement and repair of the ascending aorta. Preoperatively, four of the 13 patients were in New York Heart Association (NYHA) Class IV (3/4 required emergency operation), three patients were in Class III, and six were in Class II. The aortic diameter at the mid-valve level ranged from 5.3 cm to 8.2 cm on M-mode echocardiography. The first two patients received a separate Björk-Shiley prosthesis and a woven Teflon graft and the last 11 patients had a composite valve-graft with direct coronary implantation. There were no hospital deaths. Follow-up ranges from 6 months to 8.1 years and is complete for all 13 patients (mean of 23 months). Two late deaths occurred 2 and 20 months postoperatively from presumed arrhythmia and two late deaths occurred at 4 and 6 months from endocarditis. The actuarial survival rate at 3 years is 61%. Some pathologists claim that the incidence of dissection of the aorta does not increase with increasing aortic dilatation in the Marfan patient. Six of our 13 patients, however, had aortic dissection at the time of surgery (two DeBakey Type I, three Type II, and one Type III). With the low hospital mortality that can now be achieved in the Marfan patient, and with the relatively high incidence of clinically unrecognized dissection, we fell that strong consideration should be given to earlier prophylactic repair in these patients. Operation may be indicated even in the asymptomatic Marfan patient with an aortic root diameter greater than 5.5 cm.

  2. A patient with ascending aortic dilatation, similar to phenotypes of connective tissue disorders.

    PubMed

    Onrat, S T; Emmiler, M; Sivaci, Y; Söylemez, Z; Ozgöz, A; Imirzalioğlu, N

    2009-04-14

    We report on the clinical and molecular findings of a patient who presented alopecia, epicanthus, micrognathia, retrognathia, high arched palate, hypertelorism, Chiari type I malformation, mixed-type hearing loss but with normal heartbeat Q-T interval, malformed earlobes, down-slanted palpebral fissures, downturned corners of the mouth, syndactyly, atopic eczema, and seizures. The patient was a male adult, 23 years old, with short stature (153 cm) and low weight (50.5 kg), due to severe aortic insufficiency and dilatation of the ascending aorta. Conventional cytogenetic screening did not show any chromosomal gains or losses. Molecular genetic screening was conducted for gene mutations involved in various syndromes; the mutations found included [beta-fibrinogen -455 G>A wt/wt (wt/mut), PAI-1 4G/5G (4G/4G), HPA1 a/b (a/a), MTHFR C677T wt/wt (wt/mut), ACE I/D (I/I), and Apo E E3/E4]. Many clinical and molecular genetics findings overlapped with other conditions associated with arterial tortuosity and arterial aneurysms, including the Marfan, Ehler-Danlos, Shprintzen-Goldberg, and Loeys-Dietz syndromes. Although a diagnosis of Shprintzen-Goldberg syndrome was based on clinical findings and radiographic findings indicate other syndromes, aortic root dilatation seems to be a new symptom, similar to phenotypes of connective tissue disorders. The unique grouping of clinical manifestations in this patient and the molecular genetics findings lead us to suggest that this case could be an example of a previously unrecognized syndrome.

  3. Low SWaP Semiconductor Laser Transmitter Modules For ASCENDS Mission Applications

    NASA Technical Reports Server (NTRS)

    Prasad, Narasimha S.; Rosiewicz, Alex; Coleman, Steven M.

    2012-01-01

    The National Research Council's (NRC) Decadal Survey (DS) of Earth Science and Applications from Space has identified the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) as an important atmospheric science mission. NASA Langley Research Center, working with its partners, is developing fiber laser architecture based intensity modulated CW laser absorption spectrometer for measuring XCO2 in the 1571 nm spectral band. In support of this measurement, remote sensing of O2 in the 1260 nm spectral band for surface pressure measurements is also being developed. In this paper, we will present recent progress made in the development of advanced transmitter modules for CO2 and O2 sensing. Advanced DFB seed laser modules incorporating low-noise variable laser bias current supply and low-noise variable temperature control circuit have been developed. The 1571 nm modules operate at >80 mW and could be tuned continuously over the wavelength range of 1569-1574nm at a rate of 2 pm/mV. Fine tuning was demonstrated by adjusting the laser drive at a rate of 0.7 pm/mV. Heterodyne linewidth measurements have been performed showing linewidth 200 kHz and frequency jitter 75 MHz. In the case of 1260 nm DFB laser modules, we have shown continuous tuning over a range of 1261.4 - 1262.6 nm by changing chip operating temperature and 1261.0 - 1262.0 nm by changing the laser diode drive level. In addition, we have created a new laser package configuration which has been shown to improve the TEC coefficient of performance by a factor of 5 and improved the overall efficiency of the laser module by a factor of 2.

  4. Dilation of the ascending aorta after balloon valvuloplasty for aortic stenosis during infancy and childhood.

    PubMed

    McElhinney, Doff B; Lacro, Ronald V; Gauvreau, Kimberlee; O'Brien, Cheryl M; Yaroglu Kazanci, Selcen; Vogel, Melanie; Emani, Sitaram; Brown, David W

    2012-09-01

    Dilation of the ascending aorta (AA) is common in patients with a bicuspid aortic valve. The natural history of the aortic root and AA and the risk factors for dilation have not been characterized in patients with congenital aortic stenosis (AS) treated with balloon valvuloplasty during childhood. The present study was performed to determine the prevalence of aortic dilation in patients with congenital AS before and up to 20 years after balloon valvuloplasty performed during childhood. In patients who underwent balloon valvuloplasty for AS at age ≤ 18 years from 1984 to 2005, the aortic diameter measurements before intervention and at 5-year intervals afterward were recorded and the Z scores calculated. Among 156 patients (median age 1.5 years at valvuloplasty), the AA Z scores were significantly larger than normal before intervention (median Z score 1.5) and at all follow-up points (all p <0.001). Using mixed modeling, with time as a categorical variable (before intervention, 5-year window, 10-year window, and so forth), the mean AA Z score was greater at all postvalvuloplasty points than before the intervention, with mean Z score increases of 1.20 at 5 years and 2.11 at 20 years (p <0.001). Moderate or greater aortic regurgitation early after valvuloplasty was associated with greater AA Z scores than mild or less aortic regurgitation, with a progressive difference over time. More significant residual AS after valvuloplasty was associated with lower AA Z scores over time. In conclusion, AA dilation is common in children with congenital AS and continues to progress over many years after balloon valvuloplasty.

  5. Left ventricular hypertrophy in ascending aortic stenosis mice: anoikis and the progression to early failure

    NASA Technical Reports Server (NTRS)

    Ding, B.; Price, R. L.; Goldsmith, E. C.; Borg, T. K.; Yan, X.; Douglas, P. S.; Weinberg, E. O.; Bartunek, J.; Thielen, T.; Didenko, V. V.; Lorell, B. H.; Schneider, M. (Principal Investigator)

    2000-01-01

    BACKGROUND: To determine potential mechanisms of the transition from hypertrophy to very early failure, we examined apoptosis in a model of ascending aortic stenosis (AS) in male FVB/n mice. METHODS AND RESULTS: Compared with age-matched controls, 4-week and 7-week AS animals (n=12 to 16 per group) had increased ratios of left ventricular weight to body weight (4.7+/-0.7 versus 3.1+/-0.2 and 5. 7+/-0.4 versus 2.7+/-0.1 mg/g, respectively, P<0.05) with similar body weights. Myocyte width was also increased in 4-week and 7-week AS mice compared with controls (19.0+/-0.8 and 25.2+/-1.8 versus 14. 1+/-0.5 microm, respectively, P<0.01). By 7 weeks, AS myocytes displayed branching with distinct differences in intercalated disk size and staining for beta(1)-integrin on both cell surface and adjacent extracellular matrix. In vivo left ventricular systolic developed pressure per gram as well as endocardial fractional shortening were similar in 4-week AS and controls but depressed in 7-week AS mice. Myocyte apoptosis estimated by in situ nick end-labeling (TUNEL) was extremely rare in 4-week AS and control mice; however, a low prevalence of TUNEL-positive myocytes and DNA laddering were detected in 7-week AS mice. The specificity of TUNEL labeling was confirmed by in situ ligation of hairpin oligonucleotides. CONCLUSIONS: Our findings indicate that myocyte apoptosis develops during the transition from hypertrophy to early failure in mice with chronic biomechanical stress and support the hypothesis that the disruption of normal myocyte anchorage to adjacent extracellular matrix and cells, a process called anoikis, may signal apoptosis.

  6. Development of a Long-Term Ascending Urinary Tract Infection Mouse Model for Antibiotic Treatment Studies

    PubMed Central

    Hvidberg, Hanne; Struve, Carsten; Krogfelt, Karen A.; Christensen, Nils; Rasmussen, Søren N.; Frimodt-Møller, Niels

    2000-01-01

    A model of ascending unobstructed urinary tract infection (UTI) in mice was developed to study the significance of the antibiotic concentration in urine, serum, and kidney tissue for efficacy of treatment of UTI in general and pyelonephritis in particular. Outbred Ssc-CF1 female mice were used throughout the study, and Escherichia coli was used as the pathogen. The virulence of 11 uropathogenic E. coli isolates and 1 nonpathogenic laboratory E. coli strain was examined. Strain C175-94 achieved the highest counts in the kidneys, and this strain was subsequently used as the infecting organism. The model gave reproducible bladder infections, i.e., bacteria were recovered from 22 of 23 control mice after 3 days, and histological examination of kidney tissue showed that of 14 infected kidneys, 7 (50%) showed major histological changes, whereas 3 of 36 uninfected kidneys showed major histological changes (P = 0.018). Once the model was established, the efficacies of different doses of cefuroxime and gentamicin, corresponding to active concentrations in urine only or in urine, serum, and kidney tissue simultaneously, were examined. All cefuroxime doses resulted in significantly lower counts in urine than control treatments, but the dose which produced concentrations of cefuroxime only in urine and not in serum or kidney tissue had no effect on kidney infection. Even low doses of gentamicin (0.05 mg/mouse) resulted in concentrations in renal tissue for prolonged times due to accumulation. All gentamicin doses had a significant effect (compared to the effect of the control treatment) on bacterial counts in urine and kidneys. The antibiotic effect on bacterial counts in bladders was negligible for unknown reasons. Use of the mouse UTI model is feasible for study of the effect of an antibiotic in the urinary system, although the missing antibacterial effect in the bladder needs further evaluation. PMID:10602738

  7. [A CASE OF ASCENDING COLON CANCER RECURRENCE WITH INTRALUMINAL URETERAL DISSEMINATION MIMICKING PRIMARY URETERAL CANCER, DETECTED DURING INVESTIGATION FOR FEVER].

    PubMed

    Nishiyama, Ryuichi; Kubota, Masashi; Kanno, Toru; Okada, Takashi; Higashi, Yoshihito; Yamada, Hitoshi

    2015-10-01

    A 69-year-old woman visited our hospital with a chief complaint of fever. Five years ago, she was diagnosed as ascending colon cancer and received right hemi-colectomy. One year later, local recurrence with right hydronephrosis was detected, and she received chemotherapy -4 cycles of modified fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) plus bevacizumab, and 12 cycles of fluorouracil, leucovorin, and irinotecan (FOLFIRI) plus bevacizumab- for two years. Local recurrence and right hydronephrosis disappeared on positron emission tomography performed 4 years postoperatively. This time, abdominal computed tomography for investigation of fever showed a relapse of right hydronephrosis and pyonephrosis. Cystoscopy revealed non-papillary tumor from the right ureteral orifice. Pelvic magnetic resonance imaging showed multiple tumors in the right ureter, and the distal lesion projecting into the bladder. After the general condition became well by right nephrostomy for infection control, transurethral resection of bladder tumor was performed. Histological examination of the specimen revealed a metastatic tubular adenocarcinoma (colon origin). Although right nephrectomy was performed for pyonephrosis control, she died of local progression of ascending colon cancer 10 months after first visit. Intralumin