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Sample records for lumboperitoneal lp shunt

  1. The role of lumboperitoneal shunts in the treatment of syringomyelia.

    PubMed

    Oluigbo, Chima O; Thacker, Karen; Flint, Graham

    2010-07-01

    OBJECT The role of thecoperitoneal shunts in the management of syringomyelia is not well defined. In this study, the authors analyze the outcome of lumboperitoneal shunt procedures carried out to treat syringomyelia in their institution. METHODS The authors retrospectively reviewed the medical records of 19 patients who underwent lumboperitoneal shunt procedures for syringomyelia. RESULTS The mean follow-up duration was 25 months (range 3-51 months). Of 16 cases followed up, only 5 patients reported clinical improvement in their preoperative symptoms, but of these, 2 had clear radiological evidence of improvement. Three of 6 patients with syringomyelia due to spinal arachnoiditis improved. CONCLUSIONS Lumboperitoneal shunts may lead to useful improvement in the symptoms of a patient with syringomyelia while avoiding the risk of neurological deterioration inherent in myelotomies required for syrinx shunting procedures.

  2. Laparoscopic Cholecystectomy for a Patient with a Lumboperitoneal Shunt: A Rare Case.

    PubMed

    Rumba, Roberts; Vanags, Andrejs; Strumfa, Ilze; Pupkevics, Andrejs; Pavars, Maris

    2016-01-01

    A rare factor that can complicate the perioperative course of laparoscopic cholecystectomy is previous placement of a lumboperitoneal (LP) shunt. Thus far, only two articles describing this situation have been published. Here, we report on a 41-year-old female patient with gallstone disease and a LP shunt placement in the preceding year due to idiopathic intracranial hypertension. It is a syndrome of increased intracranial pressure without any known cause that mainly affects young obese women. The patient was operated upon using standard port placement and peritoneal insufflation. The postoperative period was uneventful and the patient was discharged shortly after the procedure. Due to the increasing incidence and prevalence of obesity, the number of general surgical patients with a LP shunt will likely increase. Based on our experience and evidence in the literature, we conclude that performing a laparoscopy for a patient with a LP shunt is safe. PMID:27452939

  3. Laparoscopic Cholecystectomy for a Patient with a Lumboperitoneal Shunt: A Rare Case.

    PubMed

    Rumba, Roberts; Vanags, Andrejs; Strumfa, Ilze; Pupkevics, Andrejs; Pavars, Maris

    2016-01-01

    A rare factor that can complicate the perioperative course of laparoscopic cholecystectomy is previous placement of a lumboperitoneal (LP) shunt. Thus far, only two articles describing this situation have been published. Here, we report on a 41-year-old female patient with gallstone disease and a LP shunt placement in the preceding year due to idiopathic intracranial hypertension. It is a syndrome of increased intracranial pressure without any known cause that mainly affects young obese women. The patient was operated upon using standard port placement and peritoneal insufflation. The postoperative period was uneventful and the patient was discharged shortly after the procedure. Due to the increasing incidence and prevalence of obesity, the number of general surgical patients with a LP shunt will likely increase. Based on our experience and evidence in the literature, we conclude that performing a laparoscopy for a patient with a LP shunt is safe.

  4. Delayed intracerebellar hemorrhage secondary to lumboperitoneal shunt insertion

    PubMed Central

    Er, Uygur; Akyol, Çetin; Bavbek, Murad

    2016-01-01

    Aim of this paper is to present and discuss a case of a delayed cerebellar parenchymal hemorrhage developing after L/P shunt placement with a NPH patient. A hypertensive patient admitted to our clinic with a diagnosis of NPH. The patient was placed a pressure adjustable L/P shunt without any surgical complication. He was discharged with an uneventful period. The patient was admitted to the emergency clinic of our hospital with a 1.5 × 1.5 cm diameter hematoma at the left cerebellar hemisphere on 2 days after his discharge. CSF drainage by an L/P shunt can generate intracerebellar hemorrhages especially in hypertensive patients.

  5. Delayed intracerebellar hemorrhage secondary to lumboperitoneal shunt insertion

    PubMed Central

    Er, Uygur; Akyol, Çetin; Bavbek, Murad

    2016-01-01

    Aim of this paper is to present and discuss a case of a delayed cerebellar parenchymal hemorrhage developing after L/P shunt placement with a NPH patient. A hypertensive patient admitted to our clinic with a diagnosis of NPH. The patient was placed a pressure adjustable L/P shunt without any surgical complication. He was discharged with an uneventful period. The patient was admitted to the emergency clinic of our hospital with a 1.5 × 1.5 cm diameter hematoma at the left cerebellar hemisphere on 2 days after his discharge. CSF drainage by an L/P shunt can generate intracerebellar hemorrhages especially in hypertensive patients. PMID:27695558

  6. Lumboatrial shunt in a patient with Crouzon syndrome complicated by pseudotumor cerebri.

    PubMed

    Sankey, Eric W; Khattab, Mohamed H; Elder, Benjamin D; Goodwin, C Rory; Rekate, Harold L; Rigamonti, Daniele

    2015-09-01

    A 25-year-old man with Crouzon syndrome complicated by pseudotumor cerebri and multiple shunt failures presented with progressive back and neck pain, intermittent headaches, and associated vomiting secondary to shunt infection. Due to his previous history of repeated failure of both ventriculoperitoneal and lumboperitoneal (LP) shunting procedures, the decision was made to place a lumboatrial (LA) shunt via an approach through the internal jugular vein. The procedure was uncomplicated and the man's symptoms were relieved. Despite significant improvement, the LA shunt limited his exercise tolerance, and as an avid runner and weight lifter, he requested reconversion back to an LP shunt. At a follow-up of 20months, he continued to do well both clinically and radiographically. This case report summarizes the successful placement and use of an LA shunt for the treatment of intracranial hypertension in the setting of Crouzon syndrome. PMID:26021731

  7. [Unilateral Posterior Reversible Encephalopathy Syndrome after Ventriculo-Peritoneal Shunt for Normal Pressure Hydrocephalus Following Subarachnoid Hemorrhage: A Case Report].

    PubMed

    Sato, Hiroyuki; Koizumi, Takayuki; Sato, Daisuke; Endo, Shin; Kato, Syunichi

    2016-06-01

    The patient, a 79-year-old man, experienced a Hunt & Kosnik grade IV subarachnoid hemorrhage, presenting with sudden-onset coma and severe left hemiplegia. We performed cranial clipping surgery for a ruptured aneurysm on the right middle cerebral artery the same day. Post-operative recovery proceeded smoothly, with gradual improvements in disturbed consciousness and left hemiplegia. Three weeks post-operation, CT revealed low-density areas in the right frontal and temporal lobe, believed to be due to subarachnoid hemorrhage, as well as hydrocephaly. We then performed a lumbo-peritoneal (L-P) shunt for the hydrocephaly. Two months later, the patient experienced shunt occlusion, and we performed a ventriculo-peritoneal (V-P) shunt revision (pressure: 6 cm H(2)O). Headaches, severe decline in cognitive function, and worsened left hemiplegia were observed seven weeks post-shunt revision. Cranial CT revealed widespread low-density areas in right posterior cerebral white matter. We suspected unilateral posterior reversible encephalopathy syndrome (PRES) after performing cranial MRI and cerebral angiography. Increasing the set pressure of the shunt improved the symptoms and radiographic findings. PRES is typically bilateral, and unilateral incidents are rare. This is the first report of unilateral PRES secondary to shunt operation. Its unilaterality appears to have been caused by unilateral brain damage or adhesions to the brain surface from the subarachnoid cerebral hemorrhage. Overdrainage post-shunt can also induce PRES. Diagnosis of PRES is more difficult in unilateral cases;practitioners must keep PRES in mind as a rare complication post-shunt operation. PMID:27270150

  8. Ventriculoperitoneal shunting

    MedlinePlus

    The person may need to lie flat for 24 hours the first time a shunt is placed. How long the hospital stay is depends on the reason the shunt is needed. The health care team will ... Follow the provider's instructions about how to take care of ...

  9. Shunt Devices for the Treatment of Adult Hydrocephalus: Recent Progress and Characteristics

    PubMed Central

    MIYAKE, Hiroji

    2016-01-01

    Various types of shunt valves have been developed during the past 50 years, most of which can be classified into the following categories: (1) fixed differential pressure valves; (2) fixed differential pressure (DP) valves with an antisiphon mechanism; (3) programmable DP valves; (4) programmable DP valves with an antisiphon mechanism; and (5) programmable antisiphon valves. When considering the myriad of possible postoperative condition changes, such as the onset of accidental non-related diseases or trauma in adults, and changes in normal physiological development or anticipation of future shunt removal in children, it has become standard to use the programmable valve as a first choice for cerebrospinal fluid shunting. However, it is still unclear what type of shunt valve is suitable for each individual case. Based on the results of SINPHONI and more recently SINPHONI 2 trials, the programmable DP valve is recommended as the first line shunt valve. The programmable DP valve with an antisiphon mechanism is thought to be beneficial for tall, slender patients, who have a tendency for easily developing complications of overdrainage, however, this type of valve must be used cautiously in obese patients because of the increased risk of underdrainage. Although the current evidence is still insufficient, the programmable antisiphon valve, which costs the same as the programmable DP valve, is also thought to be the first line shunt valve. The quick reference table is applicable for most shunt valves, and for patients with either the ventriculoperitoneal or the lumboperitoneal shunt. PMID:27041631

  10. Shunt Devices for the Treatment of Adult Hydrocephalus: Recent Progress and Characteristics.

    PubMed

    Miyake, Hiroji

    2016-05-15

    Various types of shunt valves have been developed during the past 50 years, most of which can be classified into the following categories: (1) fixed differential pressure valves; (2) fixed differential pressure (DP) valves with an antisiphon mechanism; (3) programmable DP valves; (4) programmable DP valves with an antisiphon mechanism; and (5) programmable antisiphon valves. When considering the myriad of possible postoperative condition changes, such as the onset of accidental non-related diseases or trauma in adults, and changes in normal physiological development or anticipation of future shunt removal in children, it has become standard to use the programmable valve as a first choice for cerebrospinal fluid shunting. However, it is still unclear what type of shunt valve is suitable for each individual case. Based on the results of SINPHONI and more recently SINPHONI 2 trials, the programmable DP valve is recommended as the first line shunt valve. The programmable DP valve with an antisiphon mechanism is thought to be beneficial for tall, slender patients, who have a tendency for easily developing complications of overdrainage, however, this type of valve must be used cautiously in obese patients because of the increased risk of underdrainage. Although the current evidence is still insufficient, the programmable antisiphon valve, which costs the same as the programmable DP valve, is also thought to be the first line shunt valve. The quick reference table is applicable for most shunt valves, and for patients with either the ventriculoperitoneal or the lumboperitoneal shunt.

  11. Shunt Devices for the Treatment of Adult Hydrocephalus: Recent Progress and Characteristics.

    PubMed

    Miyake, Hiroji

    2016-05-15

    Various types of shunt valves have been developed during the past 50 years, most of which can be classified into the following categories: (1) fixed differential pressure valves; (2) fixed differential pressure (DP) valves with an antisiphon mechanism; (3) programmable DP valves; (4) programmable DP valves with an antisiphon mechanism; and (5) programmable antisiphon valves. When considering the myriad of possible postoperative condition changes, such as the onset of accidental non-related diseases or trauma in adults, and changes in normal physiological development or anticipation of future shunt removal in children, it has become standard to use the programmable valve as a first choice for cerebrospinal fluid shunting. However, it is still unclear what type of shunt valve is suitable for each individual case. Based on the results of SINPHONI and more recently SINPHONI 2 trials, the programmable DP valve is recommended as the first line shunt valve. The programmable DP valve with an antisiphon mechanism is thought to be beneficial for tall, slender patients, who have a tendency for easily developing complications of overdrainage, however, this type of valve must be used cautiously in obese patients because of the increased risk of underdrainage. Although the current evidence is still insufficient, the programmable antisiphon valve, which costs the same as the programmable DP valve, is also thought to be the first line shunt valve. The quick reference table is applicable for most shunt valves, and for patients with either the ventriculoperitoneal or the lumboperitoneal shunt. PMID:27041631

  12. Management for traumatic chronic subdural hematoma patients with well-controlled shunt system for hydrocephalus.

    PubMed

    Yamada, Shoko Mitrrt; Tomia, Yusuke; Murakami, Hideki; Nakane, Makoto

    2015-07-01

    Traumatic CSDH enlarged in two cases with VP or LP shunt system although the shunt valve pressure was increased to 200 mmH2O. In surgery, the hematoma cavity pressure was found to be 130 and 140 mmH2O, suggesting that to raise the shunt valve pressure is not effective for decreasing CSDH volume.

  13. Controversies: Optic nerve sheath fenestration versus shunt placement for the treatment of idiopathic intracranial hypertension

    PubMed Central

    Spitze, Arielle; Lam, Peter; Al-Zubidi, Nagham; Yalamanchili, Sushma; Lee, Andrew G

    2014-01-01

    Background: Idiopathic intracranial hypertension (IIH) has been increasing in prevalence in the past decade, following the obesity epidemic. When medical treatment fails, surgical treatment options must be considered. However, controversy remains as to which surgical procedure is the preferred surgical option – optic nerve sheath fenestration (ONSF) or cerebrospinal fluid (CSF) shunting – for the long-term treatment of this syndrome. Purpose: To provide a clinical update of the pros and cons of ONSF versus shunt placement for the treatment of IIH. Design: This was a retrospective review of the current literature in the English language indexed in PubMed. Methods: The authors conducted a PubMed search using the following terms: Idiopathic IIH, pseudotumor cerebri, ONSF, CSF shunts, vetriculo-peritoneal shunting, and lumbo-peritoneal shunting. The authors included pertinent and significant original articles, review articles, and case reports, which revealed the new aspects and updates in these topics. Results: The treatment of IIH remains controversial and lacks randomized controlled clinical trial data. Treatment of IIH rests with the determination of the severity of IIH-related visual loss and headache. Conclusion: The decision for ONSF versus shunting is somewhat institution and surgeon dependent. ONSF is preferred for patients with visual symptoms whereas shunting is reserved for patients with headache. There are positive and negative aspects of both procedures, and a prospective, randomized, controlled trial is needed (currently underway). This article will hopefully be helpful in allowing the reader to make a more informed decision until that time. PMID:25449938

  14. Ventriculoperitoneal shunt - discharge

    MedlinePlus

    ... ventriculoperitoneal - discharge; VP shunt - discharge; Shunt revision - discharge; Hydrocephalus shunt placement - discharge ... Your child has hydrocephalus and needed a shunt placed to drain excess fluid and relieve pressure in the brain. This buildup of brain ...

  15. CSF shunt infections: a fifteen-year experience with emphasis on management and outcome.

    PubMed

    Morissette, I; Gourdeau, M; Francoeur, J

    1993-05-01

    A retrospective study of patients with cerebrospinal fluid shunt infections was undertaken from 1975 to 1989 in a university hospital. The data were analyzed with emphasis on the choice of treatment and outcome. There were 44 infectious episodes in 38 patients for an overall rate of 2.6%, including 30 ventriculoperitoneal, 11 ventriculoatrial and 3 lumboperitoneal shunts. The most frequently isolated pathogens were staphylococci in 61% of the cases followed by gram-negative bacilli in 25%. Different modalities of treatment were used: support (2), intravenous antibiotics alone (6), intravenous antibiotics and shunt revision (3), intravenous antibiotics and shunt removal with or without prior externalization of the distal end (33: 13 + 20). The cure rate was 94% (31/33) with this last modality of treatment. Only 3 patients received intraventricular antibiotics. All deaths occurred in patients treated with support only (2) or with antibiotics alone (1). Four of the six recurrent episodes occurred in patients treated with antibiotics alone (2) or with a shunt revision (2). We conclude that carefully chosen intravenous antibiotics combined with shunt removal preceded or not by externalization of the distal end as an alternative therapy to repeated ventricular taps or insertion of an external ventricular drainage device is an appropriate therapy.

  16. Distal splenorenal shunt

    MedlinePlus

    ... shunt procedure; Renal - splenic venous shunt; Warren shunt; Cirrhosis - distal splenorenal; Liver failure - distal splenorenal ... hepatitis Blood clots Certain congenital disorders Primary biliary cirrhosis When blood cannot flow normally through the portal ...

  17. Ventriculomammary shunt: an unusual ventriculoperitoneal shunt complication.

    PubMed

    Chaudhry, Nauman S; Johnson, Jeremiah N; Morcos, Jacques J

    2015-02-01

    Ventriculoperitoneal (VP) shunt malfunctions are common and can result in significant consequences for patients. Despite the prevalence of breast augmentation surgery and breast surgery for other pathologies, few breast related VP shunt complications have been reported. A 54-year-old woman with hydrocephalus post-subarachnoid hemorrhage returned 1 month after VP shunt placement complaining of painful unilateral breast enlargement. After investigation, it was determined that the distal VP shunt catheter had migrated from the peritoneal cavity into the breast and wrapped around her breast implant. The breast enlargement was the result of cerebrospinal fluid retention. We detail this unusual case and review all breast related VP shunt complications reported in the literature. To avoid breast related complications related to VP shunt procedures, it is important to illicit pre-procedural history regarding breast implants, evade indwelling implants during catheter tunneling and carefully securing the abdominal catheter to prevent retrograde catheter migration to the breast.

  18. Polytetrafluoroethylene sponge syringosubarachnoid shunt.

    PubMed

    Chagla, Aadil S; Kansal, Ritesh; Srikant, Balasubramaniam

    2011-01-01

    Syringomyelia is condition in which a cyst or cavity forms inside the spinal cavity. Its management always remains a difficult. A variety of surgical techniques have been used in management of syringomyelia. Syringosubarachnoid shunt remains an effective method in management of syringomyelia. Shunt tube obstruction remains an important complication of shunt procedure. We describe a novel technique of use of polytetrafluoroethylene sponge shunt for syringosubarachnoid shunt in patient with large syrinx and Chiari 1 malformation. Polytetrafluoroethylene sponge is a non irritant material with multiple porosities that is less susceptible to blockages or kinking. It could provide a good alternative technique in syringosubarachnoid shunting.

  19. Hydrocephalus and Shunts

    MedlinePlus

    ... or anesthesia. When ventricles start to get too big, it is a strong sign that the shunt is not working right. It is important to know that some people (between 5 and 15 percent) with Spina Bilda may have ...

  20. Shunt tube calcification as a late complication of ventriculoperitoneal shunting

    PubMed Central

    Salim, Abubakr Darrag; Elzain, Mohammed Awad; Mohamed, Haddab Ahmed; Ibrahim Zayan, Baha Eldin Mohamed

    2015-01-01

    Shunt calcification is a rare complication of ventriculoperitoneal shunting that occurs years later after the initial operation this condition is rarely reported in literature. Two patients with shunt calcifications were described. The first patient was 17-year-old lady who had congenital hydrocephalus and shunted in the early infancy, she was presented recently complaining of itching of the skin along the shunt track and limitation of neck movement. The patient was then operated with removal of the old peritoneal catheter and replacing it with a new one. The second patient was 17-year-old boy originally was a case of posterior fossa pilocytic astrocytoma associated with obstructive hydrocephalus, he was operated with both shunting for the hydrocephalus and tumor removal, 6 years later he presented with shunt exposure. Calcification of the shunt tube was discovered intraoperatively upon shunt removal. Shunt calcification has been observed mainly in barium-impregnated catheters. Introducing plain silicone-coated shunt tubing may reduce the rate of this condition. The usual complaints of the patients suffering from this condition are pain in the neck and chest wall along the shunt pathway and limitation of the neck movement due to shunt tube tethering, but features of shunt dysfunction and skin irritation above the shunt may be present. In this review, plain X-ray and operative findings showed that the most extensive calcification is present in the neck, where the catheters were subject to heavy mechanical stress. Disturbed calcium and phosphate metabolisms may be involved in this condition. Shunt calcification is a rare condition that occurs due to material aging presenting with features of shunt tethering, dysfunction or overlying skin irritation. Plain X-ray is needed to detect calcification while shunt removal, replacement or endoscopic third ventriculostomy may carry solution for this condition. PMID:26396620

  1. TRANSJUGULAR INTRAHEPATIC PORTOSYSTEMIC SHUNT

    PubMed Central

    Patidar, Kavish R.; Sydnor, Malcolm; Sanyal, Arun J.

    2014-01-01

    Transjugular intrahepatic portosystemic shunt (TIPS) is an established procedure for the complications of portal hypertension. The largest body of evidence for its use has been supported for recurrent or refractory variceal bleeding and refractory ascites. Its use has also been advocated for acute variceal bleed, hepatic hydrothorax, and hepatorenal syndrome. With the replacement of bare metal stents with polytetrafluoroethylen (PTFE) covered stents, shunt patency has improved dramatically thus improving outcomes. Therefore, reassessment of its utility, management of its complications, and understanding of various TIPS techniques is important. PMID:25438287

  2. Subgaleal migration of a ventriculoperitoneal shunt.

    PubMed

    Al Hinai, Qasim S; Pawar, Sanjay J; Sharma, Rewati Raman; Devadas, R V

    2006-07-01

    Blockage of a ventriculoperitoneal (VP) shunt is very common. Here, we describe an unusual case of shunt blockage in an infant. He was shunted for hydrocephalus associated with a Dandy-Walker malformation diagnosed at birth. At surgery, the entire VP shunt was found to have migrated into the subgaleal space, which clinically presented as shunt obstruction. We suggest techniques to avoid this rare, but preventable, complication of shunt surgery.

  3. Association between high biomarker probability of Alzheimer's disease and improvement of clinical outcomes after shunt surgery in patients with idiopathic normal pressure hydrocephalus.

    PubMed

    Kazui, Hiroaki; Kanemoto, Hideki; Yoshiyama, Kenji; Kishima, Haruhiko; Suzuki, Yukiko; Sato, Shunsuke; Suehiro, Takashi; Azuma, Shingo; Yoshimine, Toshiki; Tanaka, Toshihisa

    2016-10-15

    We examined the effect of the pathology of Alzheimer's disease (AD) on improvement of clinical symptoms after shunt surgery in patients with idiopathic normal pressure hydrocephalus (iNPH). Forty-four iNPH patients were classified into 18 patients with (iNPH/AD+) and 26 patients without (iNPH/AD-) combination with low amyloid β42 and high total tau in cerebrospinal fluid (CSF). We compared improvements after lumbo-peritoneal shunt surgery (LPS) between the two groups in Timed Up & Go Test, 10-m reciprocating walking test, Digit Symbol Substitution Test, attention test, delayed recall test, Mini-Mental State Examination, iNPH grading scale, Neuropsychiatric Inventory, Zarit Burden Interview, and other evaluations. Three months after LPS, gait, urination, overall cognition, psychomotor speed, attention, and neuropsychiatric symptoms significantly improved in both groups, but the improvement in delayed recall and reduction of caregiver burden were significantly greater in iNPH/AD- than iNPH/AD+. In addition, improvement in delayed recall score after LPS was significantly and negatively correlated with the probability of AD as judged by amyloid β42 and total tau levels in CSF. Three months after LPS, almost all of the triad symptoms decreased in iNPH patients with and without AD pathology but memory improved only in iNPH patients without AD pathology. PMID:27653897

  4. 30 CFR 56.6401 - Shunting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shunting. 56.6401 Section 56.6401 Mineral....6401 Shunting. Except during testing— (a) Electric detonators shall be kept shunted until connected to the blasting line or wired into a blasting round; (b) Wired rounds shall be kept shunted...

  5. To shunt or not to shunt: hydrocephalus and dysraphism.

    PubMed

    Rekate, H L

    1985-01-01

    Objective criteria are available for decision making in children with ventriculomegaly and spina bifida cystica. Figure 29.7 is the evaluation algorithm used in the Hydrocephalus/Myelodysplasia Clinic at Rainbow Babies and Children's Hospital. In children without serious neurosurgical complications such as the Chiari crisis or problems with wound healing, we rely on three reasonably objective measurements for decision making. Head circumference: Measured daily while in hospital and at each visit. If the pattern of head growth crosses multiple percentile lines indicating that the child will be severely megalencephalic, a shunt will be performed. Ultrasonography: Ultrasound determinations are made in the first few days of life, prior to discharge, at 6 weeks of age, and each 6 weeks of age until 6 months. Some measurements of ventricular size (usually CT scan because of a small anterior fontanelle) should be made at age 1 year. Denver Developmental Testing (DDST): These are performed at age 6 weeks and each 6 weeks thereafter. If the child shows significant ventriculomegaly, a shunt is performed. When the results are questionable the decision is delayed and the test repeated in 6 weeks. Whether a shunt is or is not placed in an infant with ventriculomegaly and myelodysplasia, follow-up must remain compulsive. Following shunting, not only should the head circumference stabilize, but the cortical mantle should increase. Often children shunted in this situation fail to show signs of increased intracranial pressure with shunt malfunction and must be followed with serial head circumference measurements as well as ultrasounds and CT scans. If the decision is made not to shunt the child the work of Hall et al. (10) would suggest the possibility that later in life shunts may be needed to prevent scoliosis secondary to hydromyelia. More information is needed as the aggressively treated population become adults. PMID:2415285

  6. 76 FR 9771 - SFPP, L.P.; SFPP, L.P.; SFPP, L.P.; SFPP, L.P.; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket Nos. OR96-2-018; IS98-1-006; Docket Nos. OR92-8-033; OR93-5- 020; OR94-4-021; Docket No. IS06-215-003; Docket No. IS06-220-002] SFPP, L.P.; SFPP, L.P.; SFPP, L.P.; SFPP, L.P.; Notice of Filing Take notice that...

  7. [Clinical analysis of pediatric shunt catheter fracture].

    PubMed

    Morishita, Akitsugu; Nagashima, Tatsuya; Kurata, Hiromitsu; Eguchi, Takahiro; Tamaki, Norihiko

    2002-08-01

    Between 1985 and 1998, 415 shunt dysfunctions occurred at Kobe Children's Hospital. The main reasons for shunt revision were obstruction of the catheter, shunt infection, and shunt disconnection. This report presents an analysis of 35 patients (36 cases) who underwent a ventriculoperitoneal (VP) shunt revision because of shunt catheter fracture. All patients were less than 18 years old. We researched their age at the time of revision, site of disruption, postoperative period, shunt system, clinical symptoms, and other factors. The mechanical aspects of shunt catheter fracture are also discussed in this report. The peak time of shunt catheter fracture was the time when children were growing up and were entering elementary school. In other words, when their height was increasing rapidly. At that time, the distal catheter is subjected to traction between the valve and the abdomen at the site of insertion in either the upper or lower direction. However, physical examination of the shunt catheter showed normal range. Additional contributory factors were chronic stimulation at the occipital bone, clavium bone, and costal arch, while movement of the neck and body rotation also caused shunt catheter fracture. These factors all originated from shearing strain at the shunt catheter. We look forward to the introduction of a stronger shunt catheter, because surgical repair time must be minimized to protect the child's mental development. In addition, shearing strain at the shunt catheter needs special attention.

  8. 49 CFR 236.838 - Wire, shunt.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Wire, shunt. 236.838 Section 236.838 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Wire, shunt. A wire forming part of a shunt circuit....

  9. 30 CFR 57.6401 - Shunting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shunting. 57.6401 Section 57.6401 Mineral...-Surface and Underground § 57.6401 Shunting. Except during testing— (a) Electric detonators shall be kept shunted until connected to the blasting line or wired into a blasting round; (b) Wired rounds shall...

  10. Disconnection as a cause of ventriculoperitoneal shunt malfunction in multicomponent shunt systems.

    PubMed

    Aldrich, E F; Harmann, P

    The cause of malfunction in 275 consecutive ventriculoperitoneal (VP) shunt revisions over an 8-year period were retrospectively analyzed. In all cases the shunt revised was a multicomponent (Holter) VP shunt. Disconnections in the system accounted for 41 (15%) of the malfunctions. The more distal the connection was from the ventricle, the higher the likelihood of disconnection. Furthermore, occipitally placed shunts had a significantly higher tendency to dislocate than frontally placed shunts.

  11. Students with Shunts: Program Considerations.

    ERIC Educational Resources Information Center

    French, Ron; And Others

    1997-01-01

    Examines how the medical condition of hydrocephalus can affect physical education students and physical education programs, and stresses the need to provide physical educators with information on students' medical conditions. Describes hydrocephalus and its treatment with ventricular peritoneal shunts, and offers suggestions on modifying…

  12. Ventriculoperitoneal shunt perforations of the gastrointestinal tract.

    PubMed

    Thiong'o, Grace Muthoni; Luzzio, Christopher; Albright, A Leland

    2015-07-01

    OBJECT The purposes of this study were to evaluate the frequency with which children presented with ventriculoperitoneal (VP) shunt perforations of the gastrointestinal (GI) tract, to determine the type of shunts that caused the perforations, and to compare the stiffness of perforating catheters with the stiffness of catheters from other manufacturers. METHODS Medical records were reviewed of 197 children who were admitted with VP shunt malfunction. Catheter stiffness was evaluated by measuring relative resistance to cross-sectional compression, resistance to column buckling, and elasticity in longitudinal bending. Catheter frictional force was measured per unit length. RESULTS Six children were identified whose VP shunts had perforated the GI tract; 2 shunts subsequently protruded through the anal orifice, 1 protruded through the oral cavity, and 3 presented with subcutaneous abscesses that tracked upward from the intestine to the chest. All perforating shunts were Chhabra shunts. Catheter stiffness and resistance to bending were greatest with a Medtronic shunt catheter, intermediate with a Codman catheter, and least with a Chhabra catheter. Frictional force was greatest with a Chhabra catheter and least with a Medtronic catheter. CONCLUSIONS The frequency of perforations by Chhabra shunts appears to be higher than the frequency associated with other shunts. The increased frequency does not correlate with their stiffness but may reflect their greater frictional forces.

  13. Shunt regulation electric power system

    NASA Technical Reports Server (NTRS)

    Wright, W. H.; Bless, J. J. (Inventor)

    1971-01-01

    A regulated electric power system having load and return bus lines is described. A plurality of solar cells interconnected in a power supplying relationship and having a power shunt tap point electrically spaced from the bus lines is provided. A power dissipator is connected to the shunt tap point and provides for a controllable dissipation of excess energy supplied by the solar cells. A dissipation driver is coupled to the power dissipator and controls its conductance and dissipation and is also connected to the solar cells in a power taping relationship to derive operating power therefrom. An error signal generator is coupled to the load bus and to a reference signal generator to provide an error output signal which is representative of the difference between the electric parameters existing at the load bus and the reference signal generator. An error amplifier is coupled to the error signal generator and the dissipation driver to provide the driver with controlling signals.

  14. A wireless monitoring system for Hydrocephalus shunts.

    PubMed

    Narayanaswamy, A; Nourani, M; Tamil, L; Bianco, S

    2015-08-01

    Patients with Hydrocephalus are usually treated by diverting the excess Cerebrospinal Fluid (CSF) to other parts of the body using shunts. More than 40 percentage of shunts implanted fail within the first two years. Obstruction in the shunts is one of the major causes of failure (45 percent) and the detection of obstruction reduces the complexity of the revision surgery. This paper describes a proposed wireless monitoring system for clog detection and flow measurement in shunts. A prototype was built using multiple pressure sensors along the shunt catheters for sensing the location of clog and flow rate. Regular monitoring of flow rates can be used to adjust the valve in the shunt to prevent over drainage or under drainage of CSF. The accuracy of the flow measurement is more than 90 percent.

  15. Cell shunt resistance and photovoltaic module performance

    SciTech Connect

    McMahon, T.J.; Basso, T.S.; Rummel, S.R.

    1996-09-01

    Shunt resistance of cells in photovoltaic modules can affect module power output and could indicate flawed manufacturing processes and reliability problems. The authors describe a two-terminal diagnostic method to directly measure the shunt resistance of individual cells in a series-connected module non-intrusively, without deencapsulation. Peak power efficiency vs. light intensity was measured on a 12-cell, series-connected, single crystalline module having relatively high cell shunt resistances. The module was remeasured with 0.5-, 1-, and 2-ohm resistors attached across each cell to simulate shunt resistances of several emerging technologies. Peak power efficiencies decreased dramatically at lower light levels. Using the PSpice circuit simulator, they verified that cell shunt and series resistances can indeed be responsible for the observed peak power efficiency vs. intensity behavior. They discuss the effect of basic cell diode parameters, i.e., shunt resistance, series resistance, and recombination losses, on PV module performance as a function of light intensity.

  16. [Infection of cerebrospinal fluid shunt systems].

    PubMed

    Jiménez-Mejías, Manuel E; García-Cabrera, Emilio

    2008-04-01

    Cerebrospinal fluid (CSF) shunt infection is a cause of considerable morbidity and mortality. Shunt infection is produced mainly during surgery and by surgical wound infection. Staphylococcus spp. (> 50% methicillin-resistant) are the most common causative bacteria, although gram-negative bacilli (10%-25%) and Propionibacterium acnes are becoming increasingly implicated. Shunt malfunction syndrome and fever are the most frequent clinical manifestations, whereas signs of meningeal irritation are uncommon. Other clinical manifestations depend on the location of the distal catheter. CSF should be obtained by puncture of the shunt reservoir or the distal catheter and processed for biochemical analyses, cell count, Gram stain, and aerobic and anaerobic cultures (lengthy incubation). Because of biofilm formation and to avoid recurrences, the recommended treatment is intravenous antibiotics plus removal of all components of the infected shunt, followed by placement of an external drainage catheter and a new shunt. Prophylaxis is important and can include antimicrobial prophylaxis and/or antibiotic-impregnated catheters.

  17. Arterioportal shunts on dynamic computed tomography

    SciTech Connect

    Nakayama, T.; Hiyama, Y.; Ohnishi, K.; Tsuchiya, S.; Kohno, K.; Nakajima, Y.; Okuda, K.

    1983-05-01

    Thirty-two patients, 20 with hepatocelluar carcinoma and 12 with liver cirrhosis, were examined by dynamic computed tomography (CT) using intravenous bolus injection of contrast medium and by celiac angiography. Dynamic CT disclosed arterioportal shunting in four cases of hepatocellular carcinoma and in one of cirrhosis. In three of the former, the arterioportal shunt was adjacent to a mass lesion on CT, suggesting tumor invasion into the portal branch. In one with hepatocellular carcinoma, the shunt was remote from the mass. In the case with cirrhosis, there was no mass. In these last two cases, the shunt might have been caused by prior percutaneous needle puncture. In another case of hepatocellular carcinoma, celiac angiography but not CT demonstrated an arterioportal shunt. Thus, dynamic CT was diagnostic in five of six cases of arteriographically demonstrated arterioportal shunts.

  18. 21 CFR 886.3920 - Aqueous shunt.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Aqueous shunt. 886.3920 Section 886.3920 Food and... OPHTHALMIC DEVICES Prosthetic Devices § 886.3920 Aqueous shunt. (a) Identification. An aqueous shunt is an... Review Guidance of 2/12/90 (K90-1),” and (3) “Aqueous Shunts—510(k) Submissions.”...

  19. Radiological Insertion and Management of Peritoneovenous Shunt

    SciTech Connect

    Bratby, M. J.; Hussain, F. F. Lopez, A. J.

    2007-06-15

    The purpose of the study was to report our experience of the management of complications following the insertion of a peritoneovenous shunt for intractable malignant ascites. From June 1999 to January 2006, 26 patients underwent insertion of a peritoneovenous shunt for ascites by interventional radiologists. We have used ultrasound and shuntography to assist in the diagnosis of the cause of shunt blockage. Successful techniques for the restoration of the shunt function include port- pumping, stripping of any fibrin sheath, and revision of either the venous or peritoneal catheter. The procedure was initially successful in all patients with continued patency until death in 17. A further four patients are still alive with a functioning shunt. There was one rapid postprocedure death resulting from pulmonary edema. Two patients developed pneumothorax, managed successfully with either a chest drain or aspiration. Shunt dysfunction occurred eight times in seven patients. There were five successful revisions in four patients. Overall, shunt patency has been maintained in 80.1% of patients. Shunt dysfunction is seen in a significant number of patients, but successful revision of the shunt can be achieved in the majority.

  20. [Unusual abdominal complication of ventriculoperitoneal shunt].

    PubMed

    Guillén, A; Costa, J M; Castelló, I; Claramunt, E; Cardona, E

    2002-10-01

    The most common complications after CSF shunting to treat hydrocephalus are shunt infection and obstruction. Although ventriculoperitoneal (VP) diversion of the CSF using artificial shunt devices is an accepted method for the management of hydrocephalus, high rates of various complications have been reported, ranging from 24% to 47%. Among these, abdominal complications account for approximately 25%. The incidence of bowel perforation by shunt-catheter is known to be as low as 0.1-0.7%. We describe a case of migration af a peritoneal catheter through a congenital hernia of Morgagni.

  1. Headaches in patients with shunts.

    PubMed

    Rekate, Harold L; Kranz, Dory

    2009-03-01

    Headache is one of the most common afflictions suffered by humans. Headache in patients with a shunt triggers a series of events that includes utilization of expensive technologies and often potentially dangerous surgical intervention. The purpose of this study was to determine the incidence of headaches in patients with shunts and, hopefully, the relationship of those headache disorders to the treatment of hydrocephalus. The Hydrocephalus Association maintains a self-reporting database recorded from individuals treated for hydrocephalus and their families. This database was mined to determine the incidence of severe headaches requiring treatment and interfering with normal life in patients who have been treated for hydrocephalus. There were 1,242 responders between the ages of 19 months and 45 years of age. Of these, 1,233 answered the question, "Do you or your family member suffer from (does your child complain of) frequent or chronic headaches?" This subset forms the basis of this study. Three groups were defined by age: children (19 months-12 years), adolescents (13 years-19 years), and young adults (20 years-45 years). Most respondents were initially treated during infancy (before 18 months of age); 84% of children and 69% of both adolescents and young adults were treated very early in life. Severe headaches became a more frequent problem as the age of the population treated for hydrocephalus increased. In terms of frequency and severity of headaches, direct comparisons with epidemiologic studies of normal populations are difficult because of the limitations of data available in the database. However, it is likely that this population has a higher incidence of severe headaches than normal populations. The cost of management of headaches in this population is very high, and the patients are at risk throughout life. Early treatment decisions have a significant effect on later quality of life. Strategies that lead to normalization of cerebrospinal fluid dynamics

  2. Analysis of light curve of LP Camelopardalis

    NASA Astrophysics Data System (ADS)

    Prudil, Z.; Skarka, M.; Zejda, M.

    2016-05-01

    We present photometric analysis of the RRab type pulsating star LP Cam. The star was observed at Brno Observatory and Planetarium during nine nights. Measurements were calibrated to the Johnson photometric system. Four captured and thirteen previously published maxima timings allowed us to refine the pulsation period and the zero epoch. The light curve was Fourier decomposed to estimate physical parameters using empirical relations. Our results suggest that LP Cam is a common RR Lyrae star with high, almost solar metallicity.

  3. 21 CFR 882.4545 - Shunt system implantation instrument.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the implantation of cerebrospinal fluid shunts, and includes tunneling instruments for passing shunt components under the skin. (b) Classification. Class I (general controls). When made only of surgical...

  4. 21 CFR 882.4545 - Shunt system implantation instrument.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the implantation of cerebrospinal fluid shunts, and includes tunneling instruments for passing shunt components under the skin. (b) Classification. Class I (general controls). When made only of surgical...

  5. 49 CFR 236.802 - Shunt.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Shunt. 236.802 Section 236.802 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.802 Shunt. A...

  6. 21 CFR 874.3820 - Endolymphatic shunt.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Endolymphatic shunt. 874.3820 Section 874.3820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3820 Endolymphatic shunt....

  7. 21 CFR 874.3820 - Endolymphatic shunt.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Endolymphatic shunt. 874.3820 Section 874.3820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3820 Endolymphatic shunt....

  8. 21 CFR 874.3820 - Endolymphatic shunt.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Endolymphatic shunt. 874.3820 Section 874.3820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3820 Endolymphatic shunt....

  9. 21 CFR 874.3820 - Endolymphatic shunt.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3820 Endolymphatic shunt. (a) Identification. An endolymphatic shunt is a device that consists of a tube or sheet intended to be implanted to relieve the symptons of vertigo. The device permits the unrestricted flow of excess endolymph from...

  10. 21 CFR 874.3820 - Endolymphatic shunt.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3820 Endolymphatic shunt. (a) Identification. An endolymphatic shunt is a device that consists of a tube or sheet intended to be implanted to relieve the symptons of vertigo. The device permits the unrestricted flow of excess endolymph from...

  11. 49 CFR 234.229 - Shunting sensitivity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Shunting sensitivity. 234.229 Section 234.229 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., Inspection, and Testing Maintenance Standards § 234.229 Shunting sensitivity. Each highway-rail...

  12. 49 CFR 236.56 - Shunting sensitivity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Shunting sensitivity. 236.56 Section 236.56 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Track Circuits § 236.56 Shunting sensitivity. Each track circuit controlling home...

  13. 49 CFR 236.56 - Shunting sensitivity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Shunting sensitivity. 236.56 Section 236.56 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Track Circuits § 236.56 Shunting sensitivity. Each track circuit controlling home...

  14. 49 CFR 234.229 - Shunting sensitivity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Shunting sensitivity. 234.229 Section 234.229 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., Inspection, and Testing Maintenance Standards § 234.229 Shunting sensitivity. Each highway-rail...

  15. 49 CFR 236.56 - Shunting sensitivity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Shunting sensitivity. 236.56 Section 236.56 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Track Circuits § 236.56 Shunting sensitivity. Each track circuit controlling home...

  16. 49 CFR 236.56 - Shunting sensitivity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Shunting sensitivity. 236.56 Section 236.56 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Track Circuits § 236.56 Shunting sensitivity. Each track circuit controlling home...

  17. 49 CFR 236.56 - Shunting sensitivity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Shunting sensitivity. 236.56 Section 236.56 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Track Circuits § 236.56 Shunting sensitivity. Each track circuit controlling home...

  18. Shunt failure caused by valve collapse.

    PubMed

    Lundar, T; Langmoen, I A; Hovind, K H

    1991-06-01

    Shunt failure due to collapse of the Mini-Holter valve was observed 13 times in 11 out of 179 children with an implanted Mini-Holter ventriculo-peritoneal (VP) or ventriculo-atrial (VA) shunt during a 10 year period. Intussusception of the proximal or distal end of the valve thus caused a shunt failure rate of 6% of the children in this series. Two children experienced this complication twice. All collapsed valves were part of a VP shunt system. Because of this experience use of the mini valve was abandoned and an adult Holter valve was implanted in children over the age of one month. Breakdown of this particular valve has not occurred in 102 children and two hundred adults with the adult Holter shunt system.

  19. Congenital Portosystemic Shunt: Our Experience

    PubMed Central

    Timpanaro, Tiziana; Passanisi, Stefano; Sauna, Alessandra; Trombatore, Claudia; Pennisi, Monica; Petrillo, Giuseppe; Smilari, Pierluigi; Greco, Filippo

    2015-01-01

    Introduction. Congenital portosystemic venous malformations are rare abnormalities in which the portal blood drains into a systemic vein and which are characterized by extreme clinical variability. Case Presentations. The authors present two case reports of a congenital extrahepatic portosystemic shunt (Type II). In the first patient, apparently nonspecific symptoms, such as headache and fatigue, proved to be secondary to hypoglycemic episodes related to the presence of a portosystemic shunt, later confirmed on imaging. During portal vein angiography, endovascular embolization of the portocaval fistula achieved occlusion of the anomalous venous tract. In the second patient, affected by Down's syndrome, the diagnosis of a portosystemic malformation was made by routine ultrasonography, performed to rule out concurrent congenital anomalies. Because of the absence of symptoms, we chose to observe this patient. Conclusions. These two case reports demonstrate the clinical heterogeneity of this malformation and the need for a multidisciplinary approach. As part of a proper workup, clinical evaluation must always be followed by radiographic diagnosis. PMID:25709849

  20. Distal ventriculoperitoneal shunt failure caused by silicone allergy. Case report.

    PubMed

    Hussain, Namath S; Wang, Paul P; James, Carol; Carson, Benjamin S; Avellino, Anthony M

    2005-03-01

    The placement of a ventriculoperitoneal (VP) shunt is the most common form of treatment for hydrocephalus. Although allergic reactions to the silicone in shunt hardware are very rare, the authors describe a case of silicone allergy causing multiple ventricular shunt revisions. A 24-year-old man, who had undergone multiple VP shunt revisions, presented with shunt malfunction caused by allergic reaction of the tissues surrounding the shunt tubing. The patient's existing silicone-based shunt was replaced with a new polyurethane system, including the proximal and distal catheters as well as the valve mechanism. Contrary to recommendations in previous studies of silicone shunt allergies, long-term immunosuppression was not initiated. The patient was followed up for more than 8 years without recurrence of an allergic reaction to the shunt. This outcome indicates that replacing the original silicone-based shunt system with a polyurethane-based system alone is sufficient in the treatment of a silicone shunt allergy.

  1. 78 FR 25262 - TexStar Transmission, LP; TEAK Texana Transmission Company, LP; Notice of Filings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission TexStar Transmission, LP; TEAK Texana Transmission Company, LP; Notice of Filings Take notice that on April 23, 2013, the applicants listed above submitted an amendment to...

  2. 78 FR 22872 - TexStar Transmission, LP; TEAK Texana Transmission Company, LP; Notice of Filings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission TexStar Transmission, LP; TEAK Texana Transmission Company, LP; Notice of Filings Take notice that on April 5, 2013, the applicants listed above submitted an amendment to...

  3. Transanal protrusion of a ventriculoperitoneal shunt catheter.

    PubMed

    Ozturk, Hulya; Is, Merih; Ozturk, Hayrettin; Kucuk, Adem; Dosoglu, Murat

    2012-11-01

    A two years old boy presented with a transanal protrusion of the ventriculoperitoneal (VP) shunt catheter. A VP shunt was inserted when the boy was six-month-old for congenital hydrocephalus. He was active and neurologically normal, with no signs of meningitis and peritoneal irritation. During laparotomy, the tube was seen entering the sigmoid colon, so the tube was cut at the point where it entered the sigmoid colon. The distal end of the protruding tube was pulled out from the anus. The sigmoid colon was repaired, and a delayed shunt revision was completed. The patient was discharged without abdominal and neurological deterioration.

  4. Transanal protrusion of a ventriculoperitoneal shunt catheter.

    PubMed

    Ozturk, Hulya; Is, Merih; Ozturk, Hayrettin; Kucuk, Adem; Dosoglu, Murat

    2012-11-01

    A two years old boy presented with a transanal protrusion of the ventriculoperitoneal (VP) shunt catheter. A VP shunt was inserted when the boy was six-month-old for congenital hydrocephalus. He was active and neurologically normal, with no signs of meningitis and peritoneal irritation. During laparotomy, the tube was seen entering the sigmoid colon, so the tube was cut at the point where it entered the sigmoid colon. The distal end of the protruding tube was pulled out from the anus. The sigmoid colon was repaired, and a delayed shunt revision was completed. The patient was discharged without abdominal and neurological deterioration. PMID:23146859

  5. Ventriculoperitoneal Shunt Peritoneal Catheter Knot Formation

    PubMed Central

    Ul-Haq, Anwar; Al-Otaibi, Faisal; Alshanafey, Saud; Sabbagh, Mohamed Diya; Al Shail, Essam

    2013-01-01

    The ventriculoperitoneal (VP) shunt is a common procedure in pediatric neurosurgery that carries a risk of complications at cranial and abdominal sites. We report on the case of a child with shunt infection and malfunction. The peritoneal catheter was tethered within the abdominal cavity, precluding its removal. Subsequently, laparoscopic exploration identified a knot at the distal end of the peritoneal catheter around the omentum. A new VP shunt was inserted after the infection was healed. This type of complication occurs rarely, so there are a limited number of case reports in the literature. This report is complemented by a literature review. PMID:24109528

  6. Ventriculo-peritoneal shunt performance under hyperbaric conditions.

    PubMed

    Huang, E T; Hardy, K R; Stubbs, J M; Lowe, R A; Thom, S R

    2000-01-01

    A novice scuba diver with an implanted ventriculo-peritoneal (VP) shunt inquired about the performance characteristics of his shunt while diving. A literature search revealed no information regarding shunt performance under hyperbaric conditions. The manufacturer could not certify that the shunt would function under pressure. Therefore, four VP shunts were tested according to the manufacturer's testing protocol at 1 and 4 atm abs in a multiplace hyperbaric chamber. The pressure (in mm of H2O) required to establish flow through the shunts was recorded. Trials at 1 atm abs (n = 12) and 4 atm abs (n = 12) show that all shunts performed within the pressure range specified by the manufacturer.

  7. Acute Shunt Malfunction Caused by Percutaneous Endoscopic Gastrostomy without Shunt Infection

    PubMed Central

    Choi, Jingyu; Ki, Seung Seog

    2014-01-01

    Percutaneous endoscopic gastrostomy tube placement is often performed in patients with a ventriculoperitoneal shunt and it has been accepted as a safe procedure. The authors report a case of a 50-year-old male who developed acute exacerbation of the hydrocephalus immediately after the percutaneous endoscopic gastrostomy tube placement without any signs of shunt infection, which has not been reported until now. After revision of the intraperitoneal shunt catheter, the sizes of the intracranial ventricles were normalized. PMID:25371790

  8. Syringosubarachnoid shunting using a myringotomy tube

    PubMed Central

    Leschke, Jack M.; Mumert, Michael L.; Kurpad, Shekar N.

    2016-01-01

    Background: Syringomyelia results from obstruction of cerebrospinal fluid (CSF) flow due to a multitude of causes. Often symptoms of pain, weakness, and sensory disturbance are progressive and require surgical treatment. We present here a rare technique for syringosubarachnoid shunting. Case Description: We present the case of a 38-year-old male who suffered a traumatic cervical spinal cord injury due to a motor vehicle accident. With progressive pain and motor decline, a magnetic resonance imaging was obtained and showed a new syrinx extending cervical multiple segments. A unique surgical procedure using a myringotomy tube to shunt CSF into the subarachnoid space was employed in this case. The patient's examination stabilized postoperatively, and at 2 months and 6 months follow-up visits, his strength and sensation continued to improve. Conclusion: We used a myringotomy tube for syringosubarachnoid shunting for the surgical management of a posttraumatic syrinx with good results. This technique minimizes suturing and may minimize shunt-related complications. PMID:26862456

  9. Optimal shunt compensators at nonsinusoidal busbars

    SciTech Connect

    El-Amin, I.M.; Duffuaa, S.O.; Bawah, A.U.

    1995-05-01

    A model for determining an optimal shunt capacitor value at nonsinusoidal busbars combining three basic criteria--maximizing the power factor, minimizing the line losses, and maximizing the transmission efficiency is developed. The choice of the capacitor value is constrained by the values that may cause resonance. This model was solved employing the penalty function approach and the golden Section Search algorithm for solving the linear load case. Furthermore nonlinear loads operating under nonsinusoidal conditions were investigated. The model for the nonlinear load is a two variable problem in L (inductor) and C (capacitor). The Direct Search Polytope algorithm is used. The solution of this model yields an optimal shunt LC compensator for the nonlinear load. However, since there are limitations on the practical values of shunt capacitor, a discretizing approach making use of standard shunt capacitor values is employed to guarantee a solution that can be implemented.

  10. Aneurysmal portosystemic venous shunt: a case report.

    PubMed

    Bodner, G; Glück, A; Springer, P; König, P; Perkmann, R

    1999-10-01

    A case of an aneurysmal portosystemic venous shunt detected by colour Doppler ultrasound (CDUS) is presented. A young female patient complained of postprandial fatigue and had paroxysmal tachycardia. A direct vascular communication between right portal vein and right hepatic vein was found at CDUS and confirmed by direct portal angiogram. Using detachable coils a complete occlusion of the intrahepatic shunt was obtained. Reports from the literature regarding portovenous aneurysms are reviewed.

  11. Cell shunt resistance and photovoltaic module performance

    SciTech Connect

    McMahon, T.J.; Basso, T.S.; Rummel, S.R.

    1996-05-01

    Shunt resistance of cells in photovoltaic modules can affect module power output and could indicate flawed manufacturing processes and reliability problems. The authors describe a two-terminal diagnostic method to directly measure the shunt resistance of individual cells in a series-connected module non-intrusively, without deencapsulation. Peak power efficiency vs. light intensity was measured on a 12-cell, series-connected, single crystalline module having relatively high cell shunt resistances. The module was remeasured with 0.5-, 1-, and 2-ohm resistors attached across each cell to simulate shunt resistances of several emerging technologies. Peak power efficiencies decreased dramatically at lower light levels. Using the PSpice circuit simulator, the authors verified that cell shunt and series resistances can indeed be responsible for the observed peak power efficiency vs. intensity behavior. The authors discuss the effect of basic cell diode parameters, i.e., shunt resistance, series resistance, and recombination losses, on PV module performance as a function of light intensity.

  12. Ventriculoperitoneal shunt in cryptococcal meningitis with hydrocephalus.

    PubMed

    Tang, L M

    1990-05-01

    Fourteen patients with cryptococcal meningitis were reviewed. All patients had a ventriculoperitoneal shunt for hydrocephalus. Early recognitions and prompt relief of hydrocephalus were useful for eight patients who showed rapid deterioration of consciousness or signs of cerebral herniation. There was no surgical response in four patients who had had weeks of confusion or mental change. It seems, therefore, that the duration of disturbance of consciousness or change of mentality before shunting is critical in determination of the outcome of the treatment. Ventricular shunting was effective in relieving papilledema in five patients. However, the surgery did not prevent the development of papilledema to optic atrophy and subsequent blindness in two patients. Hence, in addition to hydrocephalus with increased intracranial pressure, conditions such as direct invasion of the optic pathways by Cryptococcus neoformans or optochiasmatic arachnoiditis may be responsible for the visual failure. Ventricular shunting was also helpful in restoring paraparesis in one patient. Of the cerebrospinal fluid determinations, low protein concentration was a favorable indicator for surgery. Of the seven patients who received the surgical procedure before the start of antifungal therapy, four showed a significant improvement despite active infection of the central nervous system. None of the seven patients deteriorated because of the surgical operation. Thus, active stage of cryptococcal meningitis does not contraindicate the necessity of shunting, and premedication with antifungal drugs is unnecessary. Also, no shunt-related morbidity and mortality was seen in this study.

  13. 77 FR 26534 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-04

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Application Take notice that on April 19, 2012, Texas Eastern Transmission, LP (Texas Eastern), 5400 Westheimer Court, Houston, Texas... associated ancillary facilities in Montgomery County, Texas. Specifically, Texas Eastern proposes to...

  14. OMPS LP Characterization of Stratospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Taha, G.; Bhartia, P. K.; Xu, P.; Loughman, R. P.; Jaross, G. R.; DeLand, M. T.; Colarco, P. R.; Aquila, V.

    2015-12-01

    The Suomi NPP OMPS Limb Profiler (LP) collects limb scattered radiance data over a wide spectral range (290-1000 nm) and altitude range (0-80 km). Retrieval of aerosol extinction coefficient profiles from these measurements is complicated by the need to specify particle size distribution and composition, which may vary along a single orbit, as well as on time scales ranging from hours to months. We have developed a radiance-based product, called the Aerosol Scattering Index (ASI), that allows us to characterize many aspects of stratospheric aerosol behavior directly from LP measurements. ASI data clearly demonstrate seasonal changes in the Junge layer that vary with both altitude and latitude. The ASI data can identify volcanic plumes shortly after an eruption, and track the evolution of these plumes over weeks and months. The LP ASI product shows that polar mesospheric clouds (PMCs), although located at 80-85 km during summer months, can affect LP observations and ozone retrievals down to much lower altitudes. Short-lived phenomena such as bolide plumes and rocket exhaust trails are also captured by this product, providing unique information about perturbations in the stratosphere and mesosphere.

  15. 76 FR 53440 - Freeport LNG Development, LP; Freeport LNG Expansion, LP; FLNG Liquefaction LLC; Notice of Intent...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-26

    ... Energy Regulatory Commission Freeport LNG Development, LP; Freeport LNG Expansion, LP; FLNG Liquefaction LLC; Notice of Intent To Prepare an Environmental Assessment for the Planned Liquefaction Project...) that will discuss the environmental impacts of the Liquefaction Project (Project)...

  16. 78 FR 36182 - APL SouthTex Transmission Company LP, Formerly TEAK Texana Transmission Company, LP; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-17

    ... Energy Regulatory Commission APL SouthTex Transmission Company LP, Formerly TEAK Texana Transmission Company, LP; Notice of Filing Take notice that on June 7, 2013, APL SouthTex Transmission Company LP (APL SouthTex) filed to notify the Commission of its name change from TEAK Texana Transmission Company,...

  17. 75 FR 39680 - Houston Pipe Line Company LP, Worsham-Steed Gas Storage, L.P., Energy Transfer Fuel, LP, Mid...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-12

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR10-44-000; Docket No. PR10-46-000; Docket No. PR10-48- 000; Docket No. PR10-49-000; Docket No. PR10-50-000] Houston Pipe Line Company LP, Worsham-Steed Gas Storage, L.P., Energy Transfer Fuel, LP,...

  18. Simulation model for port shunting yards

    NASA Astrophysics Data System (ADS)

    Rusca, A.; Popa, M.; Rosca, E.; Rosca, M.; Dragu, V.; Rusca, F.

    2016-08-01

    Sea ports are important nodes in the supply chain, joining two high capacity transport modes: rail and maritime transport. The huge cargo flows transiting port requires high capacity construction and installation such as berths, large capacity cranes, respectively shunting yards. However, the port shunting yards specificity raises several problems such as: limited access since these are terminus stations for rail network, the in-output of large transit flows of cargo relatively to the scarcity of the departure/arrival of a ship, as well as limited land availability for implementing solutions to serve these flows. It is necessary to identify technological solutions that lead to an answer to these problems. The paper proposed a simulation model developed with ARENA computer simulation software suitable for shunting yards which serve sea ports with access to the rail network. Are investigates the principal aspects of shunting yards and adequate measures to increase their transit capacity. The operation capacity for shunting yards sub-system is assessed taking in consideration the required operating standards and the measure of performance (e.g. waiting time for freight wagons, number of railway line in station, storage area, etc.) of the railway station are computed. The conclusion and results, drawn from simulation, help transports and logistics specialists to test the proposals for improving the port management.

  19. Ventricular gallbladder shunts: an alternative procedure in hydrocephalus.

    PubMed

    West, K W; Turner, M K; Vane, D W; Boaz, J; Kalsbeck, J; Grosfeld, J L

    1987-07-01

    Hydrocephalus is a frequently encountered problem in infancy and is most commonly treated by placement of ventriculoperionteal (VP) or ventriculoatrial (VA) shunts. Other sites for insertion of the distal shunt have included the stomach, ureter, and fallopian tube. This report describes an experience with ventricular gallbladder shunts (VGB) in 25 children performed from 1970 to 1985. There were 13 girls and 12 boys ranging in age from 6 months to 16 years. Diagnosis included meningomyelocoele (7), congenital hydrocephalus (7), postmeningitic complications (5), intracranial tumor (4), and intraventricular hemorrhage (2). Indications for operation included VP shunt infection (15), massive ascites following VP shunt (3), VA shunt infection (4), and distal shunt malfunction due to fibrinous adhesions or cysts (secondary to infection; (3). Three patients had early shunt failure due to proximal obstruction (2) and gallbladder atony (1). Shunt revision was required in two and the atony was successfully treated with cholecystokinin in one. Fourteen shunts remain in place, two patients have been lost to follow-up, and three children died from unrelated causes. Seventy percent of the 20 patients available for long-term follow-up have functional shunts in place. The VGB shunt procedure remains an attractive alternative for patients with hydrocephalus in whom intraperitoneal and intravascular shunts are no longer feasible.

  20. Delayed Intracerebral Hemorrhage Secondary to Ventriculoperitoneal Shunt

    PubMed Central

    Ma, Li; Chen, Yi-Li; Yang, Shu-Xu; Wang, Yi-Rong

    2015-01-01

    Abstract The ventriculoperitoneal (VP) shunt is a routine procedure for cerebrospinal fluid (CSF) diversion, and is associated with many complications. A delayed hemorrhage after the VP shunt surgery, however, is quite rare. In this study, we report a case involving late-onset hemorrhage. The 67-year-old male patient with a history of head trauma and brain surgery underwent a VP shunt placement for hydrocephalus. The surgery course was uneventful and no bleeding was revealed in the first computed tomographic (CT) scan after the procedure. However, a massive intraparenchymal and intraventricular hemorrhage occurred 8 h following adjustment of the valve system on the 8th day after surgery. Erosion of the vasculature by catheter cannulation and a sudden reduction of CSF pressure after downregulation of the valve could be one of the possible causes of the intracerebral hemorrhage (ICH). PMID:26632700

  1. Radionuclide demonstration of intrapulmonary shunting in cirrhosis

    SciTech Connect

    Bank, E.R.; Thrall, J.H.; Dantzker, D.R.

    1983-05-01

    The association of hepatic cirrhosis and severe arterial hypoxemia has been well described. Although alterations in ventilatory function may partially account for the hypoxemia, the principal mechanism is thought to be a microangiopathic change in the pulmonary vasculature resulting in intrapulmonary arteriovenous shunting with resultant systemic desaturation. Whole-body radionuclide scans with technetium-99m macroaggregated albumin labeling have been diagnostic of right-to-left shunting by their demonstration of tracer accumulation within the extrapulmonary circulation. A case of severe pulmonary arteriovenous shunting in an alcoholic patient in whom hepatic disease had not been of apparent clinical significance before radionuclide scanning is reported. He did not have cuntaeous angiomata as have all other patients with alcoholic cirrhosis and hypoxemia.

  2. Radionuclide demonstration of intrapulmonary shunting in cirrhosis

    SciTech Connect

    Bank, E.R.; Thrall, J.H.; Dantzker, D.R.

    1983-05-01

    The association of hepatic cirrhosis and severe arterial hypoxemia has been well described. Although alterations in ventilatory function may partially account for the hypoxemia, the principal mechanism is thought to be a microangiopathic change in the pulmonary arteriovenous shunting with resultant systemic desaturation. Whole-body radionuclide scans with technetium-99m macroaggrregated albumin (/sup 99m/Tc MAA) labeling have been diagnostic of right-to-left shunting by their demonstration of tracer accumulation within the extrapulmonary circulation. A case of severe pulmonary arteriovenous shunting in an alcoholic patient in whom hepatic disease had not been of apparent clinical significance before radionuclide scanning is reported. He did not have cutaneous angiomata as have all other patients with alcoholic cirrhosis and hypoxemia.

  3. Seizures in relation to shunt dysfunction in children with meningomyelocele.

    PubMed

    Hack, C H; Enrile, B G; Donat, J F; Kosnik, E

    1990-01-01

    To determine whether seizures are a reliable sign of increased intraventricular pressure in children with shunt-dependent hydrocephalus and meningomyelocele, we performed a retrospective chart review of 346 patients with meningomyelocele and shunt-dependent hydrocephalus. Fifty-one patients had seizures. Seizure episodes were investigated to determine whether they were temporally associated with shunt dysfunction. Episodes of actual or presumed shunt dysfunction were analyzed as to presenting symptoms, ventriculogram, computed tomography scan, and shunt film results. These 51 patients had 129 admissions for possible shunt dysfunction. One hundred one admissions were due to increased intraventricular pressure; nine (9%) of these, had a seizure as one of the presenting symptoms. All of the nine episodes had other common presenting symptoms of shunt dysfunction, such as headache, vomiting, lethargy, or respiratory compromise. We conclude that seizures alone are an inadequate predictor of shunt dysfunction in children with meningomyelocele, but can be seen as one of the presenting symptoms.

  4. [Temporary vascular shunt technique for resource scarce environments].

    PubMed

    Ouattara, N; Mlynski, A; Pierret, C

    2011-10-01

    The purpose of this report is to describe a simple and reproducible technique for temporary vascular shunting. This technique is appropriate only for exceptional situations involving scant resource availability. It is not intended to replace conventional vascular shunting techniques.

  5. Ventricular shunt infections: immunopathogenesis and clinical management.

    PubMed

    Gutierrez-Murgas, Yenis; Snowden, Jessica N

    2014-11-15

    Ventricular shunts are the most common neurosurgical procedure performed in the United States. This hydrocephalus treatment is often complicated by infection of the device with biofilm-forming bacteria. In this review, we discuss the pathogenesis of shunt infection, as well as the implications of the biofilm formation on treatment and prevention of these infections. Many questions remain, including the contribution of glia and the impact of inflammation on developmental outcomes following infection. Immune responses within the CNS must be carefully regulated to contain infection while minimizing bystander damage; further study is needed to design optimal treatment strategies for these patients.

  6. Recovery from confabulation after normotensive hydrocephalus shunting.

    PubMed

    Dalla Barba, Gianfranco; Barbera, Claudia; Brazzarola, Marta; Marangoni, Sara

    2016-02-01

    Confabulation, the production of statements and actions that are unintentionally incongruous to the subject's history, background, present and future situation, is observed in several conditions affecting the nervous system, but it has never been described in normotensive hydrocephalus. In this article we report on a patient with normotensive hydrocephalus who suffered from an amnesic-confabulatory syndrome. After hydrocephalus shunting, both amnesia and confabulation cleared up abruptly. We discuss this finding in terms of a possible disconnection of the hippocampus, due to transitory white matter damage, which may have recovered after hydrocephalus shunting.

  7. Recurrent Breast Cancer in a Patient with a Ventriculoperitoneal Shunt

    PubMed Central

    Copeland-Halperin, Libby R.; Cohen, Robert A.

    2015-01-01

    We report a case of a patient with recurrent infiltrating ductal carcinoma of the breast encasing a ventriculoperitoneal shunt. We also review the current literature regarding reports of breast malignancy around a ventriculoperitoneal shunt, as well as the potential relevance of such shunts to the preoperative evaluation and management of patients with breast cancer. PMID:25648450

  8. Emergency department management of ventriculoperitoneal cerebrospinal fluid shunts.

    PubMed

    Madsen, M A

    1986-11-01

    Emergency physicians must be familiar with VP shunts in order to recognize critical complications associated with these devices. Knowledge of the major types of shunt devices commonly used and the mechanics of those devices allows emergency physicians to evaluate patients with shunts in an orderly manner.

  9. 49 CFR 236.57 - Shunt and fouling wires.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Shunt and fouling wires. 236.57 Section 236.57...: All Systems Track Circuits § 236.57 Shunt and fouling wires. (a) Except as provided in paragraph (b) of this section, shunt wires and fouling wires hereafter installed or replaced shall consist of...

  10. 49 CFR 236.104 - Shunt fouling circuit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Shunt fouling circuit. 236.104 Section 236.104 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Inspections and Tests; All Systems § 236.104 Shunt fouling circuit. Shunt fouling...

  11. 49 CFR 236.725 - Circuit, switch shunting.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch...

  12. 49 CFR 236.104 - Shunt fouling circuit.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Shunt fouling circuit. 236.104 Section 236.104 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Inspections and Tests; All Systems § 236.104 Shunt fouling circuit. Shunt fouling...

  13. 49 CFR 236.60 - Switch shunting circuit; use restricted.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Switch shunting circuit; use restricted. 236.60... Instructions: All Systems Track Circuits § 236.60 Switch shunting circuit; use restricted. Switch shunting circuit shall not be hereafter installed, except where tract or control circuit is opened by the...

  14. 49 CFR 236.725 - Circuit, switch shunting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch...

  15. 49 CFR 236.104 - Shunt fouling circuit.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Shunt fouling circuit. 236.104 Section 236.104 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Inspections and Tests; All Systems § 236.104 Shunt fouling circuit. Shunt fouling...

  16. 49 CFR 236.60 - Switch shunting circuit; use restricted.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Switch shunting circuit; use restricted. 236.60... Instructions: All Systems Track Circuits § 236.60 Switch shunting circuit; use restricted. Switch shunting circuit shall not be hereafter installed, except where tract or control circuit is opened by the...

  17. 49 CFR 236.60 - Switch shunting circuit; use restricted.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Switch shunting circuit; use restricted. 236.60... Instructions: All Systems Track Circuits § 236.60 Switch shunting circuit; use restricted. Switch shunting circuit shall not be hereafter installed, except where tract or control circuit is opened by the...

  18. 49 CFR 236.725 - Circuit, switch shunting.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch...

  19. [Intraabdominal metastasis of cerebellar medulloblastoma through ventriculoperitoneal shunt].

    PubMed

    Carrasco Torrents, R; Sancho, M A; Juliá, V; Montaner, A; Costa, J M; Morales, L

    2001-01-01

    We present a 6-year-old girl with cerebellar medulloblastoma causing obstructive hydrocephalus that was treated by ventriculoperitoneal shunting. The patient subsequently underwent surgical excision of the tumor followed by adjuvant craniospinal radiotherapy. Nine months after shunting, multiple intraabdominal metastatic lesions were found. Although the risk is low, ventriculoperitoneal shunting may facilitate the spread of malignant cells.

  20. 49 CFR 236.60 - Switch shunting circuit; use restricted.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Switch shunting circuit; use restricted. 236.60... Instructions: All Systems Track Circuits § 236.60 Switch shunting circuit; use restricted. Switch shunting circuit shall not be hereafter installed, except where tract or control circuit is opened by the...

  1. 49 CFR 236.104 - Shunt fouling circuit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Shunt fouling circuit. 236.104 Section 236.104 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Inspections and Tests; All Systems § 236.104 Shunt fouling circuit. Shunt fouling...

  2. 49 CFR 236.725 - Circuit, switch shunting.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch...

  3. Direct intrahepatic portacaval shunt: An experimental study

    PubMed Central

    Luo, Jian-Jun; Yan, Zhi-Ping; Zhou, Kang-Rong; Qian, Sheng

    2003-01-01

    AIM: To determine the feasibility of creating direct intrahepatic portacaval shunt (DIPS) in swine with puncture under sonographic guidance. METHODS: DIPS was created in 10 domestic swine under sonographic guidance. Liver function, blood ammonia level and portosystemic gradient (PSG) were compared before and after the procedure. Patency of shunt was followed by portography every 7 d after DIPS. RESULTS: DIPS was successfully established in all 10 swine without any complications. One day after procedure the alanine aminotransferase (ALT), aspartate aminotransferase (AST), and blood ammonia level (BAL) of swine rose from 5.40 ± 0.69, 16.00 ± 0.79 and 35.66 ± 4.10 to 34.20 ± 3.46, 59.70 ± 2.22 and 66.94 ± 3.44 respectively (P < 0.05). The PSG decreased from 0.59 ± 0.20 kPa to 0.24 ± 0.11 kPa after DIPS (P < 0.05). The shunt of 10 swine was kept patent from 7-28 d (median patency time was 14 d). CONCLUSION: This initial experience demonstrated that creating intrahepatic portacaval shunt from retrohepatic segment of IVC to portal vein with puncture under sonographic guidance in swine is safe and feasible. Further studies are necessary to perform DIPS in cirrhosis patients. PMID:12532459

  4. Treatment of syringomyelia with a syringosubarachnoid shunt.

    PubMed

    Tator, C H; Briceno, C

    1988-02-01

    The surgical results in 40 patients with syringomyelia, treated with a syringosubarachnoid shunt or other procedures are reviewed. The principal indication for surgery was that of significant neurological deterioration. There were 12 patients with idiopathic syringomyelia without tonsillar ectopia, 12 with an associated Chiari malformation, 11 with post-traumatic syringomyelia and five patients with spinal arachnoiditis. There were 38 syringosubarachnoid shunts performed in 35 patients, and an excellent or good result was achieved in 26 patients (74.3%). In terms of the type of syringomyelia, the best results were obtained in the idiopathic group without tonsillar ectopia and in the post-traumatic group. A short duration of pre-operative symptoms favoured a better outcome, and in our opinion, early surgical treatment is indicated for all patients with neurological deterioration. All eight patients in whom a posterior fossa decompression was performed as the initial surgical procedure required a second operation, either a syringosubarachnoid or syringoperitoneal shunt to achieve neurological improvement or stabilization. Thus, the syringosubarachnoid shunt is an effective therapeutic modality for patients with syringomyelia, particularly for the idiopathic and post-traumatic groups. More than one surgical procedure may be required to achieve cessation of deterioration. Overall, excellent or good results were achieved in 29 (72.5%) of the 40 patients.

  5. 49 CFR 234.229 - Shunting sensitivity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Shunting sensitivity. 234.229 Section 234.229 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... sensitivity. Each highway-rail grade crossing train detection circuit shall detect the application of a...

  6. 49 CFR 234.229 - Shunting sensitivity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Shunting sensitivity. 234.229 Section 234.229 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... sensitivity. Each highway-rail grade crossing train detection circuit shall detect the application of a...

  7. 49 CFR 234.229 - Shunting sensitivity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Shunting sensitivity. 234.229 Section 234.229 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... sensitivity. Each highway-rail grade crossing train detection circuit shall detect the application of a...

  8. The Land Processes Distributed Active Archive Center (LP DAAC)

    USGS Publications Warehouse

    Golon, Danielle K.

    2016-10-03

    The Land Processes Distributed Active Archive Center (LP DAAC) operates as a partnership with the U.S. Geological Survey and is 1 of 12 DAACs within the National Aeronautics and Space Administration (NASA) Earth Observing System Data and Information System (EOSDIS). The LP DAAC ingests, archives, processes, and distributes NASA Earth science remote sensing data. These data are provided to the public at no charge. Data distributed by the LP DAAC provide information about Earth’s surface from daily to yearly intervals and at 15 to 5,600 meter spatial resolution. Data provided by the LP DAAC can be used to study changes in agriculture, vegetation, ecosystems, elevation, and much more. The LP DAAC provides several ways to access, process, and interact with these data. In addition, the LP DAAC is actively archiving new datasets to provide users with a variety of data to study the Earth.

  9. Episodic ventriculomegaly due to hypernatremia mimicking shunt malfunction: case report.

    PubMed

    Jernigan, Sarah C; Stone, Scellig S D; Aronson, Joshua P; Putman, Melissa; Proctor, Mark R

    2015-10-01

    Patients with shunted hydrocephalus presenting with altered mental status and ventriculomegaly are generally considered to be in shunt failure requiring surgical treatment. The authors describe a case of shunted hydrocephalus secondary to a disseminated neuroectodermal tumor in a pediatric patient in whom rapid fluctuations in sodium levels due to diabetes insipidus repeatedly led to significant changes in ventricle size, with invasively confirmed normal shunt function and low intracranial pressure. This clinical picture exactly mimics shunt malfunction, requires urgent nonsurgical therapy, and underscores the importance of considering serum osmolar abnormalities in the differential diagnosis for ventriculomegaly.

  10. [Cerebrospinal fluid shunts for hydrocephalus and related disorders].

    PubMed

    Ito, Masaki; Houkin, Kiyohiro; Saito, Hisayasu; Shimbo, Daisuke; Motegi, Hiroaki; Kawabori, Masahito; Miyamoto, Michiyuki; Yamauchi, Tomohiro

    2012-10-01

    Cerebrospinal fluid (CSF) shunts are commonly employed to treat patients with hydrocephalus. A large number of papers have been published focusing on complications and failures of CSF shunts. However, there appears to be a paucity of knowledge comprehensively covering both common complications and rare ones. In this systematic review, we surveyed articles about surgical complications of CSF shunts as comprehensively as possible. Quantitative analysis was performed to determine the frequency of well-known complications, mortality and revision rates of CSF shunts. Furthermore, rare complications of CSF shunts have also been reviewed.

  11. Platypnea-Orthodeoxia Syndrome: To Shunt or Not to Shunt, That is the Question.

    PubMed

    Klein, Michael R; Kiefer, Todd L; Velazquez, Eric J

    2016-06-01

    Platypnea-orthodeoxia syndrome is a rare disease defined by dyspnea and deoxygenation, induced by an upright position, and relieved by recumbency. Causes include shunting through a patent foramen ovale and pulmonary arteriovenous malformations. A 79-year-old woman experienced 2 syncopal episodes at rest and presented at another hospital. In the emergency department, she was hypoxic, needing 6 L/min of oxygen. Her chest radiograph showed nothing unusual. Transthoracic echocardiograms with saline microcavitation evaluation were mildly positive early after agitated-saline administration, suggesting intracardiac shunting. She was then transferred to our center. Right-sided heart catheterization revealed no oximetric evidence of intracardiac shunting while the patient was supine and had a low right atrial pressure. However, her oxygen saturation dropped to 78% when she sat up. Repeat transthoracic echocardiography while sitting revealed a dramatically positive early saline microcavitation-uptake into the left side of the heart. Transesophageal echocardiograms showed a patent foramen ovale, with right-to-left shunting highly dependent upon body position. The patient underwent successful percutaneous patent foramen ovale closure, and her oxygen supplementation was suspended. In patients with unexplained or transient hypoxemia in which a cardiac cause is suspected, it is important to evaluate shunting in both the recumbent and upright positions. In this syndrome, elevated right atrial pressure is not necessary for significant right-to-left shunting. Percutaneous closure, if feasible, is first-line therapy in these patients.

  12. Platypnea-Orthodeoxia Syndrome: To Shunt or Not to Shunt, That is the Question

    PubMed Central

    Kiefer, Todd L.; Velazquez, Eric J.

    2016-01-01

    Platypnea-orthodeoxia syndrome is a rare disease defined by dyspnea and deoxygenation, induced by an upright position, and relieved by recumbency. Causes include shunting through a patent foramen ovale and pulmonary arteriovenous malformations. A 79-year-old woman experienced 2 syncopal episodes at rest and presented at another hospital. In the emergency department, she was hypoxic, needing 6 L/min of oxygen. Her chest radiograph showed nothing unusual. Transthoracic echocardiograms with saline microcavitation evaluation were mildly positive early after agitated-saline administration, suggesting intracardiac shunting. She was then transferred to our center. Right-sided heart catheterization revealed no oximetric evidence of intracardiac shunting while the patient was supine and had a low right atrial pressure. However, her oxygen saturation dropped to 78% when she sat up. Repeat transthoracic echocardiography while sitting revealed a dramatically positive early saline microcavitation-uptake into the left side of the heart. Transesophageal echocardiograms showed a patent foramen ovale, with right-to-left shunting highly dependent upon body position. The patient underwent successful percutaneous patent foramen ovale closure, and her oxygen supplementation was suspended. In patients with unexplained or transient hypoxemia in which a cardiac cause is suspected, it is important to evaluate shunting in both the recumbent and upright positions. In this syndrome, elevated right atrial pressure is not necessary for significant right-to-left shunting. Percutaneous closure, if feasible, is first-line therapy in these patients. PMID:27303248

  13. Platypnea-Orthodeoxia Syndrome: To Shunt or Not to Shunt, That is the Question.

    PubMed

    Klein, Michael R; Kiefer, Todd L; Velazquez, Eric J

    2016-06-01

    Platypnea-orthodeoxia syndrome is a rare disease defined by dyspnea and deoxygenation, induced by an upright position, and relieved by recumbency. Causes include shunting through a patent foramen ovale and pulmonary arteriovenous malformations. A 79-year-old woman experienced 2 syncopal episodes at rest and presented at another hospital. In the emergency department, she was hypoxic, needing 6 L/min of oxygen. Her chest radiograph showed nothing unusual. Transthoracic echocardiograms with saline microcavitation evaluation were mildly positive early after agitated-saline administration, suggesting intracardiac shunting. She was then transferred to our center. Right-sided heart catheterization revealed no oximetric evidence of intracardiac shunting while the patient was supine and had a low right atrial pressure. However, her oxygen saturation dropped to 78% when she sat up. Repeat transthoracic echocardiography while sitting revealed a dramatically positive early saline microcavitation-uptake into the left side of the heart. Transesophageal echocardiograms showed a patent foramen ovale, with right-to-left shunting highly dependent upon body position. The patient underwent successful percutaneous patent foramen ovale closure, and her oxygen supplementation was suspended. In patients with unexplained or transient hypoxemia in which a cardiac cause is suspected, it is important to evaluate shunting in both the recumbent and upright positions. In this syndrome, elevated right atrial pressure is not necessary for significant right-to-left shunting. Percutaneous closure, if feasible, is first-line therapy in these patients. PMID:27303248

  14. Premature fractures of platinum-cured Silastic shunts.

    PubMed

    Ramsey, D B; Chadduck, W M

    1992-10-01

    Experience with one unitized ventriculoperitoneal (VP) shunt system has disclosed an unacceptably high rate of premature distal shunt tube fracturing. From March, 1986, to February, 1989, 114 new or replacement unitized VP shunts were placed; the patients were followed through November, 1991. Twenty-two (19.3%) returned with peritoneal limb fractures, with a mean time from shunt implantation to fracture of 31.5 +/- 11.3 months (range 15-62 months). All shunts broke in the neck 1.1-11.2 cm below the valve. Of the 22 cases, there were no instances of infection, previous peritoneal limb revisions, or recognizable iatrogenic shunt injury at placement. These fractures also occurred earlier than the usual time expected for biodegradation of shunt tubing. The Silastic tubing in all of these shunts had been manufactured using a more recent platinum-curing process. This tubing has decreased elastance and is more brittle than tubing cured with the previously used dichlorobenzoyl peroxide (DCBP) catalyst. Our studies suggest that the premature shunt tube fractures were related to changes in physical characteristics of the platinum-cured Silastic tubing. Therefore, the DCBP-cured Silastic is to be considered preferable for shunting products. Neurosurgeons are asked to report recurring patterns of shunt system failure.

  15. Intraparenchymal pericatheter cyst following disconnection of ventriculoperitoneal shunt system.

    PubMed

    Balasubramaniam, S; Tyagi, D K; Sawant, H V

    2013-01-01

    Ventriculoperitoneal (VP) shunt is one of the most commonly performed procedures in neurosurgery, but it is also the procedure, which is most prone to complications. Spread of cerebrospinal fluid (CSF) into the brain parenchyma is a rare complication of VP shunt and can take the form of CSF edema or a porencephalic cyst. We describe a case of a 1½-year-old child who presented to us with seizures. Computed tomography scan revealed pericatheter porencephalic cyst. Surgical exploration revealed a disconnected VP shunt system. Patient was neurologically observed after shunt extraction. He was seizure free and radiological follow-up showed resolution of cyst. Ours is the first case to document the presence of pericatheter cyst following complete disconnection of shunt system. Though shunt revision is the accepted treatment modality, careful neurological observation can be done after shunt removal especially in asymptomatic cases with compensated hydrocephalus.

  16. Passively Shunted Piezoelectric Damping of Centrifugally-Loaded Plates

    NASA Technical Reports Server (NTRS)

    Duffy, Kirsten P.; Provenza, Andrew J.; Trudell, Jeffrey J.; Min, James B.

    2009-01-01

    Researchers at NASA Glenn Research Center have been investigating shunted piezoelectric circuits as potential damping treatments for turbomachinery rotor blades. This effort seeks to determine the effects of centrifugal loading on passively-shunted piezoelectric - damped plates. Passive shunt circuit parameters are optimized for the plate's third bending mode. Tests are performed both non-spinning and in the Dynamic Spin Facility to verify the analysis, and to determine the effectiveness of the damping under centrifugal loading. Results show that a resistive shunt circuit will reduce resonant vibration for this configuration. However, a tuned shunt circuit will be required to achieve the desired damping level. The analysis and testing address several issues with passive shunt circuit implementation in a rotating system, including piezoelectric material integrity under centrifugal loading, shunt circuit implementation, and tip mode damping.

  17. Shunt tube problems due to placement of valves on the chest wall--three case reports.

    PubMed

    Tsurushima, H; Harakuni, T; Saito, A; Hyodo, A; Yoshii, Y

    2000-06-01

    Programmable valves are often used for ventriculoperitoneal (VP) shunts with the shunt valve positioned on the chest wall. Three cases of shunt problems occurred due to placement of the valve on the chest wall. A 43-year-old male was treated with a VP shunt, and suffered shunt malfunction due to dislocation of the ventricular tube. A 21-year-old male was treated with a VP shunt, and suffered shunt malfunction due to disconnection of the shunt tube. A 4-day-old female neonate was treated with a VP shunt, and suffered migration of the shunt valve. The shunt system has two anchor sites on the head and chest wall, with the neck between the two anchor sites. High tension is sometimes caused in the shunt tube between the two points due to movement of the neck or growth, and may induce such dislocation and disconnection of the shunt tube. We recommend a longer shunt tube in such cases.

  18. Free floating ventricular shunt catheter between lateral ventricles: a case report of an unusual ventriculoperitoneal shunt complication.

    PubMed

    Erol, Fatih Serhat; Cakin, Hakan; Ozturk, Sait; Donmez, Osman; Kaplan, Metin

    2013-01-01

    Ventriculoperitoneal (VP) shunt proximal tip disconnection is rarely seen as a shunt complication. Shunt dysfunction and hydrocephaly can develop due to this disconnection. Presented here is a case of a disconnection of the ventricular catheter from the shunt valve, which passed between both lateral ventricles by free floating in the brain CT. The patient was operated on for hydrocephaly. The dysfunctional shunt valve and peritoneal catheter were removed and a new VP shunt system was implemented. Although some publications report that the ventricular catheter can be disconnected from the shunt valve, can adhere to the intraventricular structures, and can be a source of infection, no studies similar to the current case were found in the literature reporting a free floating ventricular catheter between the lateral ventricles.

  19. 75 FR 8322 - EPIC Merchant Energy NJ/PA, LP, SESCO Enterprises, LLC, Coaltrain Energy, LP, Complainants, v...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-24

    ..., Complainants, v. PJM Interconnection, LLC, Respondent; Notice of Complaint February 17, 2010. Take notice that... Enterprises, LLC, and Coaltrain Energy LP (Complainants) filed a formal complaint against PJM...

  20. Fatal cardiopulmonary complications in children treated with ventriculoatrial shunts.

    PubMed

    Lundar, T; Langmoen, I A; Hovind, K H

    1991-08-01

    During the years from 1965 to 1986, 716 children underwent a total of 2065 shunt procedures in our department. Of these, 1298 were ventriculoatrial (VA). Until 1979, Pudenz VA shunts were almost exclusively used as the primary procedure as well as in revisions. Since 1980, mini-Holter VA shunts have been implanted as a second choice, usually in cases with repeated distal failure in ventriculoperitoneal (VP) shunts. Observation time for children with VA shunts is therefore from 10 to 23 years for the great majority. The cumulative death rate for all patients is 24% (175/716), 9% (64/716) being tumor patients who eventually died as a result of their neoplasm. Most of the other deaths were caused by shunt infection or occurred in a group of children where shunts had been implanted for palliative reasons and where follow-up was only sporadic. Among the 450 children with VA shunts, 15 fatal complications occurred that were directly related to the atrial catheter, resulting in an accumulated incidence of 3% of such serious side effects from VA shunting. Three of these 15 fatal cases presented with nonspecific signs of cardiopulmonary failure following 10-21 years' shunting, and they died from irreversible pulmonary hypertension within a few months. A fourth case of late cor pulmonale has done unexpectedly well and has improved considerably while receiving anticoagulant therapy for over a period of 3 years.

  1. Who Needs a Revision? 20 Years of Cambridge Shunt Lab.

    PubMed

    Czosnyka, Zofia; Czosnyka, Marek; Pickard, John D; Chari, Aswin

    2016-01-01

    Shunt testing independent of manufacturers provides knowledge that can significantly improve the management of patients with hydrocephalus. The Cambridge Shunt Evaluation Laboratory was created 20 years ago. Thanks to financial support from the Department of Health (1993-1998), all shunts in use in the UK were systematically evaluated, with "blue reports" being published. Later new devices were tested as they appeared in public domain.Twenty-six models have been evaluated. The majority of the valves had a non-physiologically low hydrodynamic resistance that may result in over-drainage, both related to posture and during nocturnal cerebral vasogenic waves. A long distal catheter increases the resistance of these valves by 100-200 %. Drainage through valves without a siphon-preventing mechanism is very sensitive to body posture. Shunts with siphon-preventing accessories offer a reasonable resistance to negative outlet pressure. Bench parameters were used to test shunt performance in vivo using infusion tests. A criterion for correctly performing a shunt procedure was established. Pressure measured in the shunt prechamber during the plateau phase of infusion should not remain more than 5 mmHg above the le shunt's operating pressure plus hydrodynamic resistance of the valve multiplied by the infusion rate. "Critical levels" for every shunt and every performance level have been used in the shunt testing wizard of ICM+ software.

  2. Laparoscopically assisted ventriculoperitoneal shunt placement: a prospective randomized controlled trial.

    PubMed

    Schucht, Philippe; Banz, Vanessa; Trochsler, Markus; Iff, Samuel; Krähenbühl, Anna Katharina; Reinert, Michael; Beck, Jürgen; Raabe, Andreas; Candinas, Daniel; Kuhlen, Dominique; Mariani, Luigi

    2015-05-01

    OBJECT In ventriculoperitoneal (VP) shunt surgery, laparoscopic assistance can be used for placement of the peritoneal catheter. Until now, the efficacy of laparoscopic shunt placement has been investigated only in retrospective and nonrandomized prospective studies, which have reported decreased distal shunt dysfunction rates in patients undergoing laparascopic placement compared with mini-laparotomy cohorts. In this randomized controlled trial the authors compared rates of shunt failure in patients who underwent laparoscopic surgery for peritoneal catheter placement with rates in patients who underwent traditional mini-laparotomy. METHODS One hundred twenty patients scheduled for VP shunt surgery were randomized to laparoscopic surgery or mini-laparotomy for insertion of the peritoneal catheter. The primary endpoint was the rate of overall shunt complication or failure within the first 12 months after surgery. Secondary endpoints were distal shunt failure, overall complication/ failure, duration of surgery and hospitalization, and morbidity. RESULTS The overall shunt complication/failure rate was 15% (9 of 60 cases) in the laparoscopic group and 18.3% (11 of 60 cases) in the mini-laparotomy group (p = 0.404). Patients in the laparoscopic group had no distal shunt failures; in contrast, 5 (8%) of 60 patients in the mini-laparotomy group experienced distal shunt failure (p = 0.029). Intraoperative complications occurred in 2 patients (both in the laparoscopic group), and abdominal pain led to catheter removal in 1 patient per group. Infections occurred in 1 patient in the laparoscopic group and 3 in the mini-laparotomy group. The mean durations of surgery and hospitalization were similar in the 2 groups. CONCLUSIONS While overall shunt failure rates were similar in the 2 groups, the use of laparoscopic shunt placement significantly reduced the rate of distal shunt failure compared with mini-laparotomy.

  3. 78 FR 21491 - DeltaPoint Capital IV, L.P., DeltaPoint Capital IV (New York), L.P.; Notice Seeking Exemption...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-10

    ... ADMINISTRATION DeltaPoint Capital IV, L.P., DeltaPoint Capital IV (New York), L.P.; Notice Seeking Exemption... that DeltaPoint Capital IV, L.P. and DeltaPoint Capital IV (New York), L.P., 45 East Avenue, 6th Floor... Business Administration (``SBA'') Rules and Regulations (13 CFR 107.730). DeltaPoint Capital IV,...

  4. Incisional Hernia Following Ventriculoperitoneal Shunt Positioning

    PubMed Central

    Bonatti, Matteo; Vezzali, Norberto; Frena, Antonio; Bonatti, Giampietro

    2016-01-01

    Incisional hernia represents a rare complication after ventriculoperitoneal shunt positioning due to failure of the fascial suture in the site of abdominal entrance of ventriculoperitoneal catheter. Clinical presentation can be extremely variable, according to patient’s performance status, herniated material constitution (i.e. mesenteric fat, bowel loops or both) and complication occurrence (e.g. strangulation or intestinal obstruction). Early diagnosis is fundamental in order to surgically repair the defect and prevent further complications. We present the case of a paucisymptomatic incisional hernia following ventriculoperitoneal shunt positioning. Diagnosis was made by means of ultrasound and confirmed by means of computed tomography. The patient was successfully managed by means of surgical repositioning of herniated loop and re-suture. PMID:27761180

  5. 76 FR 68745 - Seneca Power Partners, L.P.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-07

    ... Energy Regulatory Commission Seneca Power Partners, L.P. v. New York Independent System Operator, Inc... Power Act, 16 U.S.C. 824e and 825e and Rule 206 of the Federal Energy Regulatory Commission's (Commission) Rules of Practice and Procedures, 18 CFR 385.206, Seneca Power Partners, L.P. (Complainant)...

  6. 76 FR 34974 - Regency Intrastate Gas LP; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Regency Intrastate Gas LP; Notice of Filing Take notice that on June 7, 2011, Regency Intrastate Gas LP, (Regency) filed to revise its Operating Statement. Regency states...

  7. 76 FR 41238 - Regency Intrastate Gas LP; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Regency Intrastate Gas LP; Notice of Filing Take notice that on July 7, 2011, Regency Intrastate Gas LP, (Regency) filed to revise its Operating Statement. Regency states this...

  8. 76 FR 9341 - Equitrans, L.P.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Equitrans, L.P.; Notice of Application Take notice that on January 27, 2011, Equitrans, L.P. (``Equitrans''), having its principal place of business at 625 Liberty Avenue, Suite...

  9. 78 FR 16846 - Notice of Application; Equitrans, L.P.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-19

    ... Energy Regulatory Commission Notice of Application; Equitrans, L.P. Take notice that on March 1, 2013, Equitrans, L.P. (Equitrans), 625 Liberty Avenue, Suite 1700, Pittsburgh, Pennsylvania 15222, filed in Docket...: 5:00 p.m. Eastern Time on April 2, 2013. Dated: March 12, 2013. Kimberly D. Bose, Secretary....

  10. 78 FR 43190 - DCP Midstream, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-19

    ... Energy Regulatory Commission DCP Midstream, LP; Notice of Application Take notice that on July 1, 2013, DCP Midstream, LP (DCP), filed an application pursuant to Section 7(c) of the Natural Gas Act and Part 157 of the Commission's Regulations, for a limited certificate authorizing DCP to construct...

  11. 76 FR 63915 - DCP Midstream, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-14

    ... Energy Regulatory Commission DCP Midstream, LP; Notice of Application Take notice that on September 23, 2011, DCP Midstream, LP (DCP), filed an application pursuant to Section 7(c) of the Natural Gas Act and Part 157 of the Commission's Regulations, for a limited jurisdiction certificate authorizing DCP...

  12. 77 FR 12045 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-28

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Application Take notice that on February 16, 2012, Texas Eastern Transmission, LP (Texas Eastern), PO Box 1642, Houston, Texas 77056 filed... appurtenances located in federal waters offshore in the Gulf of Mexico near Louisiana. Specifically,...

  13. 76 FR 49760 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-11

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Application Take notice that on July 29, 2011, Texas Eastern Transmission, LP (Texas Eastern), 5400 Westheimer Court, Houston, Texas... Uniontown Compressor Station located in Fayette County, Pennsylvania. Texas Eastern states that there...

  14. 78 FR 43874 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-22

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Application On July 2, 2013, Texas Eastern Transmission, LP (Texas Eastern) filed with the Federal Energy Regulatory Commission (Commission... more fully in the Application, Texas Eastern states that it lacks the documentation to confirm...

  15. 76 FR 7833 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-11

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Application Take notice that on January 25, 2011, Texas Eastern Transmission, LP (Texas Eastern), 5400 Westheimer Court, Houston, Texas... Gas Act (NGA) for its proposed TEAM 2012 Project. Specifically, Texas Eastern requests:...

  16. 76 FR 38381 - Texas Eastern Transmission, LP; Notice of Amendment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-30

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Amendment Take notice that on June 13, 2011, Texas Eastern Transmission, LP (Texas Eastern), 5400 Westheimer Court, Houston, Texas 77056... proposed TEAM 2012 Project. Specifically, Texas Eastern's original application is amended to reduce...

  17. 76 FR 18210 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-01

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Application On March 15, 2011, Texas Eastern Transmission Corporation (Texas Eastern), 5400 Westheimer Court, Houston, Texas 77056-5310... & Certificates, Texas Eastern Transmission, LP, P.O. Box 1642, Houston, TX 77251-1642, at (713) 627-4488...

  18. 78 FR 79687 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-31

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Texas Eastern Transmission, LP; Notice of Application Take notice that on December 10, 2013 Texas Eastern Transmission, LP (Texas Eastern), at 5400 Westheimer Court, Houston, Texas 77056, filed an application in...

  19. 75 FR 27551 - Keystone Energy Partners, LP; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Keystone Energy Partners, LP; Notice of Filing May 10, 2010. Take notice that on December 16, 2009, Keystone Energy Partners, LP submit for filing an Updated Market...

  20. 78 FR 45592 - DeltaPoint Capital IV, LP;

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-29

    ... ADMINISTRATION DeltaPoint Capital IV, LP; Notice Seeking Exemption Under Section 312 of the Small Business Investment Act, Conflicts of Interest Notice is hereby given that DeltaPoint Capital IV, L.P., 45 East Avenue... Business Administration (``SBA'') Rules and Regulations (13 CFR 107.730). DeltaPoint Capital IV,...

  1. Quantitative evaluation fo cerebrospinal fluid shunt flow

    SciTech Connect

    Chervu, S.; Chervu, L.R.; Vallabhajosyula, B.; Milstein, D.M.; Shapiro, K.M.; Shulman, K.; Blaufox, M.D.

    1984-01-01

    The authors describe a rigorous method for measuring the flow of cerebrospinal fluid (CSF) in shunt circuits implanted for the relief of obstructive hydrocephalus. Clearance of radioactivity for several calibrated flow rates was determined with a Harvard infusion pump by injecting the Rickham reservoir of a Rickham-Holter valve system with 100 ..mu..Ci of Tc-99m as pertechnetate. The elliptical and the cylindrical Holter valves used as adjunct valves with the Rickham reservoir yielded two different regression lines when the clearances were plotted against flow rats. The experimental regression lines were used to determine the in vivo flow rates from clearances calculated after injecting the Rickham reservoirs of the patients. The unique clearance characteristics of the individual shunt systems available requires that calibration curves be derived for an entire system identical to one implanted in the patient being evaluated, rather than just the injected chamber. Excellent correlation between flow rates and the clinical findings supports the reliability of this method of quantification of CSF shunt flow, and the results are fully accepted by neurosurgeons.

  2. Active shunt capacitance cancelling oscillator circuit

    DOEpatents

    Wessendorf, Kurt O.

    2003-09-23

    An oscillator circuit is disclosed which can be used to produce oscillation using a piezoelectric crystal, with a frequency of oscillation being largely independent of any shunt capacitance associated with the crystal (i.e. due to electrodes on the surfaces of the crystal and due to packaging and wiring for the crystal). The oscillator circuit is based on a tuned gain stage which operates the crystal at a frequency, f, near a series resonance frequency, f.sub.S. The oscillator circuit further includes a compensation circuit that supplies all the ac current flow through the shunt resistance associated with the crystal so that this ac current need not be supplied by the tuned gain stage. The compensation circuit uses a current mirror to provide the ac current flow based on the current flow through a reference capacitor that is equivalent to the shunt capacitance associated with the crystal. The oscillator circuit has applications for driving piezoelectric crystals for sensing of viscous, fluid or solid media by detecting a change in the frequency of oscillation of the crystal and a resonator loss which occur from contact of an exposed surface of the crystal by the viscous, fluid or solid media.

  3. Space scannable LP-DOAS system

    NASA Astrophysics Data System (ADS)

    Li, Zhenbi; Liu, Wen Qing; Wang, Ya-Ping; Feng, Qi; Zheng, Xinming

    2003-06-01

    The DOAS technique is currently the developing trend and the main technique of online monitoring of tropospheric air quality measurements. In order to enlarge the scope of monitoring with only one set of instrument, we recently developed an multi-path LP-DOAS system in which we put several sets of retroreflectors at their own appointed remote places, each makes a measuring lightpath when the telescope aligns with it. In this way we can determine high spatial resolution and two or three-dimensional trace gas distributions of a larger region with the telescope as its center. We developed a stepping-motor-based mechanics-electrical device to drive the telescope. Under the control of a PC the telescope can automatically scan these retroreflectors one by one in continuous measure cycles.

  4. LP based approach to optimal stable matchings

    SciTech Connect

    Teo, Chung-Piaw; Sethuraman, J.

    1997-06-01

    We study the classical stable marriage and stable roommates problems using a polyhedral approach. We propose a new LP formulation for the stable roommates problem. This formulation is non-empty if and only if the underlying roommates problem has a stable matching. Furthermore, for certain special weight functions on the edges, we construct a 2-approximation algorithm for the optimal stable roommates problem. Our technique uses a crucial geometry of the fractional solutions in this formulation. For the stable marriage problem, we show that a related geometry allows us to express any fractional solution in the stable marriage polytope as convex combination of stable marriage solutions. This leads to a genuinely simple proof of the integrality of the stable marriage polytope. Based on these ideas, we devise a heuristic to solve the optimal stable roommates problem. The heuristic combines the power of rounding and cutting-plane methods. We present some computational results based on preliminary implementations of this heuristic.

  5. Ventriculoperitoneal shunt dysfunction and constipation: a chart review.

    PubMed

    Bragg, C L; Edwards-Beckett, J; Eckle, N; Principe, K; Terry, D

    1994-10-01

    Children treated for hydrocephalus frequently experience chronic constipation. A retrospective chart review was conducted to determine if there is a population of children with ventriculoperitoneal (VP) shunt dysfunction in whom constipation might be a factor in the shunt dysfunction. Of 51 cases reviewed, 19 had documented constipation, such as no bowel movement for 2 or more days, small hard ball-like stools or fullness of the colon noted on physical examination or abdominal radiographs. In 6 cases, a bowel cleansing was performed and signs and symptoms of shunt dysfunction resolved without shunt revision. This review suggests that constipation may affect the fluid or pressure dynamics of the VP shunt and contribute to shunt dysfunction.

  6. CSF shunt complications: what the abdominal imager needs to know.

    PubMed

    Rinker, Eric K; Williams, Todd R; Myers, Daniel T

    2015-08-01

    Cerebrospinal fluid (CSF) shunting has been a mainstay in the treatment of hydrocephalus for many decades. With a reported 33,000 shunt placement procedures performed in the US annually, and a lifetime revision rate approaching 50%, abdominal radiologists must be familiar with the typical imaging appearance of an array of shunt complications. Complications related to the peritoneal portion of the shunt have been reported in up to 25% of patients. We present a comprehensive pictorial essay including computed tomography, conventional radiography, ultrasound, and nuclear medicine examples illustrating abdominal complications related to CSF shunting and a review of the current literature. The purpose of this pictorial essay is to provide multimodality imaging examples of CSF shunt complications and familiarize the abdominal imager with the spectrum of findings.

  7. Shunt current loss of the vanadium redox flow battery

    NASA Astrophysics Data System (ADS)

    Xing, Feng; Zhang, Huamin; Ma, Xiangkun

    The shunt current loss is one of main factors to affect the performance of the vanadium redox flow battery, which will shorten the cycle life and decrease the energy transfer efficiency. In this paper, a stack-level model based on the circuit analog method is proposed to research the shunt current loss of the vanadium redox flow battery, in which the SOC (state of charge) of electrolyte is introduced. The distribution of shunt current is described in detail. The sensitive analysis of shunt current is reported. The shunt current loss in charge/discharge cycle is predicted with the given experimental data. The effect of charge/discharge pattern on the shunt current loss is studied. The result shows that the reduction of the number of single cells in series, the decrease of the resistances of manifold and channel and the increase of the power of single cell will be the further development for the VRFB stack.

  8. 77 FR 74179 - TexStar Transmission, LP; TEAK Texana Transmission Company, LP; Notice of Baseline Filings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission TexStar Transmission, LP; TEAK Texana Transmission Company, LP; Notice of Baseline Filings Take notice that on December 6, 2012, the applicants listed above submitted a...

  9. Transjugular Intrahepatic Portosystemic Shunt Dysfunction: Concordance of Clinical Findings, Doppler Ultrasound Examination, and Shunt Venography

    PubMed Central

    Owen, Joshua M; Gaba, Ron Charles

    2016-01-01

    Objectives: The objective of this study was to evaluate the concordance between clinical symptoms, Doppler ultrasound (US), and shunt venography for the detection of stent-graft transjugular intrahepatic portosystemic shunt (TIPS) dysfunction. Materials and Methods: Forty-one patients (M:F 30:11, median age 55 years) who underwent contemporaneous clinical exam, Doppler US, and TIPS venography between 2003 and 2014 were retrospectively studied. Clinical symptoms (recurrent ascites or variceal bleeding) were dichotomously classified as present/absent, and US and TIPS venograms were categorized in a binary fashion as normal/abnormal. US abnormalities included high/low (>190 or <90 cm/s) TIPS velocity, significant velocity rise/fall (>50 cm/s), absent flow, and return of antegrade intra-hepatic portal flow. Venographic abnormalities included shunt stenosis/occlusion and/or pressure gradient elevation. Clinical and imaging concordance rates were calculated. Results: Fifty-two corresponding US examinations and venograms were assessed. The median time between studies was 3 days. Forty of 52 (77%) patients were symptomatic, 33/52 (64%) US examinations were abnormal, and 20/52 (38%) TIPS venograms were abnormal. Concordance between clinical symptoms and TIPS venography was 48% (25/52), while the agreement between US and shunt venography was 65% (34/52). Clinical symptoms and the US concurred in 60% (31/52) of the patients. The sensitivity of clinical symptoms and US for the detection of venographically abnormal shunts was 80% (16/20) and 85% (17/20), respectively. Both clinical symptoms and the US had low specificity (25%, 8/32 and 50%, 16/32) for venographically abnormal shunts. Conclusion: Clinical findings and the US had low concordance rates with TIPS venography, with acceptable sensitivity but poor specificity. These findings suggest the need for improved noninvasive imaging methods for stent-graft TIPS surveillance. PMID:27563495

  10. Factors affecting ventriculoperitoneal shunt survival in adult patients

    PubMed Central

    Khan, Farid; Rehman, Abdul; Shamim, Muhammad S.; Bari, Muhammad E.

    2015-01-01

    Background: Ventriculoperitoneal (VP) shunt insertion remains the mainstay of treatment for hydrocephalus despite a high rate of complications. The predictors of shunt malfunction have been studied mostly in pediatric patients. In this study, we report our 11-year experience with VP shunts in adult patients with hydrocephalus. We also assess the various factors affecting shunt survival in a developing country setting. Methods: A retrospective chart analysis was conducted for all adult patients who had undergone shunt placement between the years 2001 and 2011. Kaplan–Meier curves were used to determine the duration from shunt placement to first malfunction and log-rank (Cox–Mantel) tests were used to determine the factors affecting shunt survival. Results: A total of 227 patients aged 18–85 years (mean: 45.8 years) were included in the study. The top four etiologies of hydrocephalus included post-cranial surgery (23.3%), brain tumor or cyst (22.9%), normal pressure hydrocephalus (15%), and intracranial hemorrhage (13.7%). The overall incidence of shunt malfunction was 15.4% with the median time to first shunt failure being 120 days. Etiology of hydrocephalus (P = 0.030) had a significant association with the development of shunt malfunction. Early shunt failure was associated with age (P < 0.001), duration of hospital stay (P < 0.001), Glasgow Coma Scale (GCS) score less than 13 (P = 0.010), excision of brain tumors (P = 0.008), and placement of extra-ventricular drains (P = 0.033). Conclusions: Patients with increased age, prolonged hospital stay, GCS score of less than 13, extra-ventricular drains in situ, or excision of brain tumors were more likely to experience early shunt malfunction. PMID:25722930

  11. Diagnostic imaging of ventriculoperitoneal shunt malfunctions and complications.

    PubMed

    Goeser, C D; McLeary, M S; Young, L W

    1998-01-01

    Most pediatric patients with hydrocephalus are treated with ventriculoperitoneal (VP) shunt placement. However, shunt malfunction is common and is usually caused by mechanical failure. Shunt obstructions may be confirmed with radioisotope examination or with fluoroscopically guided injection of iodinated contrast material into the shunt reservoir. Disconnections or breaks are more readily detected at radiography in cases in which barium-impregnated shunt tubing was used. Migration and leakage may also occur. Cerebrospinal pseudocysts may be demonstrated with plain radiography and further evaluated with computed tomography (CT) and sonography. In increasing hydrocephalus, plain radiography may reveal sutural diastasis and increased cranial cavity size, and CT can be used to evaluate ventricle size. In cases of enlarging intracranial cysts, injection of iodinated contrast material followed by CT can help document a connection between the cyst and the ventricles. Ventriculitis and meningitis can be visualized at CT and magnetic resonance imaging as enhancement of the ventricular ependymal lining or cerebral cortical sulci. Other complications associated with VP shunts include surgery-related complications, shunt overdrainage and slit-ventricle syndrome, neoplastic metastasis, pleural effusion, and complications related to shunt variants. Imaging analysis is an essential adjunct to the clinical evaluation of patients with suspected VP shunt malfunctions or complications. Radiologists should be familiar with these potential problems and the diagnostic utility of various imaging modalities.

  12. Referred shoulder pain from ventriculoperitoneal shunts. Report of three cases.

    PubMed

    Tubbs, R Shane; Wellons, John C; Blount, Jeffrey P; Grabb, Paul A; Oakes, W Jerry

    2005-03-01

    The authors report on three pediatric patients with ventriculoperitoneal (VP) shunts who presented with chronic right shoulder pain. Imaging revealed that the distal peritoneal catheter was positioned between the right hemidiaphragm and liver. Following surgical repositioning of the distal tubing, all patients experienced resolution of their shoulder pain, which has not recurred. Although seemingly rare, referred shoulder pain from a VP shunt should be added to the list of complications seen with this method of cerebrospinal fluid diversion. The clinician who cares for patients with VP shunts may wish to evaluate cases of shoulder pain without obvious neural or musculoskeletal cause by performing imaging of the distal shunt tubing.

  13. Ventriculoperitoneal shunt malfunction caused by proximal catheter fat obstruction.

    PubMed

    Mizrahi, Cezar José; Spektor, Sergey; Margolin, Emil; Shoshan, Yigal; Ben-David, Eliel; Cohen, José E; Moscovici, Samuel

    2016-08-01

    Ventriculoperitoneal (VP) shunt placement is the mainstay of treatment for hydrocephalus, yet shunts remain vulnerable to a variety of complications. Although fat droplet migration into the subarachnoid space and cerebrospinal fluid pathways following craniotomy has been observed, a VP shunt obstruction with fat droplets has never been reported to our knowledge. We present the first reported case of VP shunt catheter obstruction by migratory fat droplets in a 55-year-old woman who underwent suboccipital craniotomy for removal of a metastatic tumor of the left medullocerebellar region, without fat harvesting. A VP shunt was inserted 1month later due to communicating hydrocephalus. The patient presented with gait disturbance, intermittent confusion, and pseudomeningocele 21days after shunt insertion. MRI revealed retrograde fat deposition in the ventricular system and VP shunt catheter, apparently following migration of fat droplets from the fatty soft tissue of the craniotomy site. Spinal tap revealed signs of aseptic meningitis. Steroid treatment for aseptic "lipoid" meningitis provided symptom relief. MRI 2months later revealed partial fat resorption and resolution of the pseudomeningocele. VP shunt malfunction caused by fat obstruction of the ventricular catheter should be acknowledged as a possible complication in VP shunts after craniotomy, even in the absence of fat harvesting.

  14. Superconducting fault current-limiter with variable shunt impedance

    SciTech Connect

    Llambes, Juan Carlos H; Xiong, Xuming

    2013-11-19

    A superconducting fault current-limiter is provided, including a superconducting element configured to resistively or inductively limit a fault current, and one or more variable-impedance shunts electrically coupled in parallel with the superconducting element. The variable-impedance shunt(s) is configured to present a first impedance during a superconducting state of the superconducting element and a second impedance during a normal resistive state of the superconducting element. The superconducting element transitions from the superconducting state to the normal resistive state responsive to the fault current, and responsive thereto, the variable-impedance shunt(s) transitions from the first to the second impedance. The second impedance of the variable-impedance shunt(s) is a lower impedance than the first impedance, which facilitates current flow through the variable-impedance shunt(s) during a recovery transition of the superconducting element from the normal resistive state to the superconducting state, and thus, facilitates recovery of the superconducting element under load.

  15. Semi-shunt field emission in electronic devices

    SciTech Connect

    Karpov, V. G.; Shvydka, Diana

    2014-08-04

    We introduce a concept of semi-shunts representing needle shaped metallic protrusions shorter than the distance between a device electrodes. Due to the lightening rod type of field enhancement, they induce strong electron emission. We consider the corresponding signature effects in photovoltaic applications; they are: low open circuit voltages and exponentially strong random device leakiness. Comparing the proposed theory with our data for CdTe based solar cells, we conclude that stress can stimulate semi-shunts' growth making them shunting failure precursors. In the meantime, controllable semi-shunts can play a positive role mitigating the back field effects in photovoltaics.

  16. A laparoscopic technique for retrieval and prevention of migration of ventriculoperitoneal shunt tubing.

    PubMed

    Klee, Vanessa M; Craft, Randall O; Zimmerman, Richard S; Harold, Kristi L

    2009-01-01

    A 31-year-old female with a history of pseudotumor cerebri presented with headache and abdominal discomfort after placement of a ventriculoperitoneal (VP) shunt. The VP shunt was placed after prior failure and revision of a lumbar peritoneal shunt. Computed tomography demonstrated shunt migration into the subcutaneous tissue. Laparoscopy was used to reposition the VP shunt, directing the shunt toward the pelvis. The patient presented for further evaluation one month later, at which point the shunt was shown to have migrated into the subcutaneous tissue once again. Laparoscopy was again used to reposition the shunt and affix it to the abdominal wall by using polytetrafluoroethylene (PTFE) mesh.

  17. Paediatric ventriculoperitoneal shunt infection caused by Actinomyces neuii.

    PubMed

    Anderson, Ian A; Jarral, Fazain; Sethi, Kavita; Chumas, Paul D

    2014-05-23

    We present the first reported case of ventriculoperitoneal shunt infection secondary to Actinomyces neuii in a paediatric patient. Our patient was managed with temporary shunt removal, intrathecal antibiotics and a prolonged course of intravenous and then oral antibiotics. She went on to make a complete recovery. Subsequent cerebrospinal fluid analysis at 5 months post-treatment demonstrated no evidence of residual infection.

  18. Spontaneous knot; a rare cause of ventriculoperitoneal shunt blockage.

    PubMed

    Mohammed, Wail; Wiig, Ulrikke; Caird, John

    2011-02-01

    A 14-year old X linked congenital hydrocephalus presented with unexplained headaches and vomiting. He had external ventricular drain and intracranial pressure monitoring (ICP). Subsequently, he underwent exploration and removal of previously inserted ventriculoperitoneal (VP) shunts. On retrieval of peritoneal catheters a double knot was noted between his two distal catheters. This case illustrates a rare cause of ventriculoperitoneal shunt malfunction.

  19. [Temporary vascular shunt technique for resource scarce environments].

    PubMed

    Ouattara, N; Mlynski, A; Pierret, C

    2011-10-01

    The purpose of this report is to describe a simple and reproducible technique for temporary vascular shunting. This technique is appropriate only for exceptional situations involving scant resource availability. It is not intended to replace conventional vascular shunting techniques. PMID:22235609

  20. Internal carotid artery rupture caused by carotid shunt insertion

    PubMed Central

    Illuminati, Giulio; Caliò, Francesco G.; Pizzardi, Giulia; Vietri, Francesco

    2015-01-01

    Introduction Shunting is a well-accepted method of maintaining cerebral perfusion during carotid endarterectomy (CEA). Nonetheless, shunt insertion may lead to complications including arterial dissection, embolization, and thrombosis. We present a complication of shunt insertion consisting of arterial wall rupture, not reported previously. Presentation of case A 78-year-old woman underwent CEA combined with coronary artery bypass grafting (CABG). At the time of shunt insertion an arterial rupture at the distal tip of the shunt was detected and was repaired via a small saphenous vein patch. Eversion CEA and subsequent CABG completed the procedure whose postoperative course was uneventful. Discussion Shunting during combined CEA-CABG may be advisable to assure cerebral protection from possible hypoperfusion due to potential hemodynamic instability of patients with severe coronary artery disease. Awareness and prompt management of possible shunt-related complications, including the newly reported one, may contribute to limiting their harmful effect. Conclusion Arterial wall rupture is a possible, previously not reported, shunt-related complication to be aware of when performing CEA. PMID:26255001

  1. 21 CFR 882.4545 - Shunt system implantation instrument.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Shunt system implantation instrument. 882.4545 Section 882.4545 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4545 Shunt system implantation instrument. (a) Identification....

  2. 49 CFR 236.724 - Circuit, shunt fouling.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Circuit, shunt fouling. 236.724 Section 236.724... Circuit, shunt fouling. The track circuit in the fouling section of a turnout, connected in multiple with the track circuit in the main track....

  3. 49 CFR 236.724 - Circuit, shunt fouling.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Circuit, shunt fouling. 236.724 Section 236.724... Circuit, shunt fouling. The track circuit in the fouling section of a turnout, connected in multiple with the track circuit in the main track....

  4. 49 CFR 236.724 - Circuit, shunt fouling.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, shunt fouling. 236.724 Section 236.724... Circuit, shunt fouling. The track circuit in the fouling section of a turnout, connected in multiple with the track circuit in the main track....

  5. 21 CFR 874.3850 - Endolymphatic shunt tube with valve.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3850 Endolymphatic shunt tube with valve. (a) Identification. An endolymphatic shunt tube with valve is a device that consists... device is the FDA guidance document “Class II Special Controls Guidance Document: Endolymphatic...

  6. 21 CFR 874.3850 - Endolymphatic shunt tube with valve.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3850 Endolymphatic shunt tube with valve. (a) Identification. An endolymphatic shunt tube with valve is a device that consists... device is the FDA guidance document “Class II Special Controls Guidance Document: Endolymphatic...

  7. 21 CFR 876.5955 - Peritoneo-venous shunt.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Peritoneo-venous shunt. 876.5955 Section 876.5955 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5955 Peritoneo-venous shunt....

  8. 21 CFR 876.5955 - Peritoneo-venous shunt.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Peritoneo-venous shunt. 876.5955 Section 876.5955 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5955 Peritoneo-venous shunt....

  9. 21 CFR 876.5955 - Peritoneo-venous shunt.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Peritoneo-venous shunt. 876.5955 Section 876.5955 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5955 Peritoneo-venous shunt....

  10. 21 CFR 876.5955 - Peritoneo-venous shunt.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Peritoneo-venous shunt. 876.5955 Section 876.5955 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5955 Peritoneo-venous shunt....

  11. 49 CFR 236.724 - Circuit, shunt fouling.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Circuit, shunt fouling. 236.724 Section 236.724... Circuit, shunt fouling. The track circuit in the fouling section of a turnout, connected in multiple with the track circuit in the main track....

  12. 21 CFR 874.3850 - Endolymphatic shunt tube with valve.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Endolymphatic shunt tube with valve. 874.3850... tube with valve. (a) Identification. An endolymphatic shunt tube with valve is a device that consists of a pressure-limiting valve associated with a tube intended to be implanted in the inner ear...

  13. 21 CFR 874.3850 - Endolymphatic shunt tube with valve.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Endolymphatic shunt tube with valve. 874.3850... tube with valve. (a) Identification. An endolymphatic shunt tube with valve is a device that consists of a pressure-limiting valve associated with a tube intended to be implanted in the inner ear...

  14. 21 CFR 874.3850 - Endolymphatic shunt tube with valve.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Endolymphatic shunt tube with valve. 874.3850... tube with valve. (a) Identification. An endolymphatic shunt tube with valve is a device that consists of a pressure-limiting valve associated with a tube intended to be implanted in the inner ear...

  15. Further developments in LP-based optimal power flow

    SciTech Connect

    Alsac, O.; Bright, J.; Prais, M.; Stott, B.P )

    1990-08-01

    Over the past twenty five years, the optimal power flow (OPF) approach that has received the most widespread practical application is the one based on linear programming (LP). Special customized LP methods have been utilized primarily for fast reliable security-constrained dispatch using decoupled separable OPF problem formulations. They have been used in power system planning, operations and control. Nevertheless, while the LP approach has a number of important attributes, its range of application in the OPF field has remained somewhat restricted. This paper describes further developments that have transformed the LP approach into a truly general-purpose OPF solver, with computational and other advantages over even recent nonlinear programming (NLP) methods. The nonseparable loss-minimization problem can now be solved, giving the same results as NLP on power systems of any size and type.

  16. Shunt attachment and method for interfacing current collection systems

    DOEpatents

    Denney, Paul E.; Iyer, Natraj C.; Hannan, III, William F.

    1992-01-01

    A composite brush to shunt attachment wherein a volatile component of a composite but mostly metallic brush, used for current collection purposes, does not upon welding or brazing, adversely affect the formation of the interfacial bond with a conductive shunt which carries the current from the zone of the brush. The brush to shunt attachment for a brush material of copper-graphite composite and a shunt of copper, or substituting silver for copper as an alternative, is made through a hot isostatic pressing (HIP). The HIP process includes applying high pressure and temperature simultaneously at the brush to shunt interface, after it has been isolated or canned in a metal casing in which the air adjacent to the interface has been evacuated and the interfacial area has been sealed before the application of pressure and temperature.

  17. Shunt attachment and method for interfacing current collection systems

    DOEpatents

    Denney, P.E.; Iyer, N.C.; Hannan, W.F. III.

    1992-12-08

    A composite brush to shunt attachment wherein a volatile component of a composite but mostly metallic brush, used for current collection purposes, does not upon welding or brazing, adversely affect the formation of the interfacial bond with a conductive shunt which carries the current from the zone of the brush. The brush to shunt attachment for a brush material of copper-graphite composite and a shunt of copper, or substituting silver for copper as an alternative, is made through a hot isostatic pressing (HIP). The HIP process includes applying high pressure and temperature simultaneously at the brush to shunt interface, after it has been isolated or canned in a metal casing in which the air adjacent to the interface has been evacuated and the interfacial area has been sealed before the application of pressure and temperature. 6 figs.

  18. Biosynthetic route towards saxitoxin and shunt pathway.

    PubMed

    Tsuchiya, Shigeki; Cho, Yuko; Konoki, Keiichi; Nagasawa, Kazuo; Oshima, Yasukatsu; Yotsu-Yamashita, Mari

    2016-02-04

    Saxitoxin, the most potent voltage-gated sodium channel blocker, is one of the paralytic shellfish toxins (PSTs) produced by cyanobacteria and dinoflagellates. Recently, putative biosynthetic genes of PSTs were reported in these microorganisms. We previously synthesized genetically predicted biosynthetic intermediates, Int-A' and Int-C'2, and also Cyclic-C' which was not predicted based on gene, and identified them all in the toxin-producing cyanobacterium Anabaena circinalis (TA04) and the dinoflagellate Alexandrium tamarense (Axat-2). This study examined the incorporation of (15)N-labeled intermediates into PSTs (C1 and C2) in A. circinalis (TA04). Conversions from Int-A' to Int-C'2, from Int-C'2 to Cyclic-C', and from Int-A' and Int-C'2 to C1 and C2 were indicated using high resolution-LC/MS. However, Cyclic-C' was not converted to C1 and C2 and was detected primarily in the extracellular medium. These results suggest that Int-A' and Int-C'2 are genuine precursors of PSTs, but Int-C'2 converts partially to Cyclic-C' which is a shunt product excreted to outside the cells. This paper provides the first direct demonstration of the biosynthetic route towards saxitoxin and a shunt pathway.

  19. Ventriculoperitoneal shunt infection with Listeria innocua.

    PubMed

    Karli, Arzu; Sensoy, Gulnar; Unal, Nevzat; Yanik, Keramettin; Cigdem, Halit; Belet, Nursen; Sofuoglu, Ayse

    2014-08-01

    Listeria species may cause life-threatening events including meningitis and invasive infection in newborns, pregnant women, older and immunodeficient people. The most common Listeria species that causes infection is L. monocytogenes. It is known that Listeria innocua has no pathogenicity. A 9-month-old baby had ventriculoperitoneal shunt and was treated with adrenocorticotropic hormone because of infantile spasms. He was brought to hospital with fever and vomiting. Upon physical examination, the patient seemed uncomfortable and had a temperature of 38.6°C. Laboratory results were as follows: hemoglobin, 6.7 g/dL; leukocyte count, 5420/mm(3) ; platelet count, 169,000/mm(3) ; and C-reactive protein, 100 mg/L (normal <5 mg/L). On analysis of cerebrospinal fluid (CSF), leukocyte count was 480/mm(3) , protein was 46 mg/dL and CSF glucose was 35 mg/dL. L. innocua was isolated in CSF culture. We describe this unusual case of ventriculoperitoneal shunt infection with L. innocua.

  20. Flexural waves focusing through shunted piezoelectric patches

    NASA Astrophysics Data System (ADS)

    Yi, K.; Collet, M.; Ichchou, M.; Li, L.

    2016-07-01

    In this paper, we designed and analyzed a piezo-lens to focus flexural waves in thin plates. The piezo-lens is comprised of a host plate and piezoelectric arrays bonded on the surfaces of the plate. The piezoelectric patches are shunted with negative capacitance circuits. The effective refractive indexes inside the piezo-lens are designed to fit a hyperbolic secant distribution by tuning the negative capacitance values. A homogenized model of a piezo-mechanical system is adopted in the designing process of the piezo-lens. The wave focusing effect is studied by the finite element method. Numerical results show that the piezo-lens can focus flexural waves by bending their trajectories, and is effective in a large frequency band. The piezo-lens has the ability to focus flexural waves at different locations by tuning the shunting negative capacitance values. The piezo-lens is shown to be effective for flexural waves generated by different types of sources.

  1. Parylene MEMS patency sensor for assessment of hydrocephalus shunt obstruction.

    PubMed

    Kim, Brian J; Jin, Willa; Baldwin, Alexander; Yu, Lawrence; Christian, Eisha; Krieger, Mark D; McComb, J Gordon; Meng, Ellis

    2016-10-01

    Neurosurgical ventricular shunts inserted to treat hydrocephalus experience a cumulative failure rate of 80 % over 12 years; obstruction is responsible for most failures with a majority occurring at the proximal catheter. Current diagnosis of shunt malfunction is imprecise and involves neuroimaging studies and shunt tapping, an invasive measurement of intracranial pressure and shunt patency. These patients often present emergently and a delay in care has dire consequences. A microelectromechanical systems (MEMS) patency sensor was developed to enable direct and quantitative tracking of shunt patency in order to detect proximal shunt occlusion prior to the development of clinical symptoms thereby avoiding delays in treatment. The sensor was fabricated on a flexible polymer substrate to eventually allow integration into a shunt. In this study, the sensor was packaged for use with external ventricular drainage systems for clinical validation. Insights into the transduction mechanism of the sensor were obtained. The impact of electrode size, clinically relevant temperatures and flows, and hydrogen peroxide (H2O2) plasma sterilization on sensor function were evaluated. Sensor performance in the presence of static and dynamic obstruction was demonstrated using 3 different models of obstruction. Electrode size was found to have a minimal effect on sensor performance and increased temperature and flow resulted in a slight decrease in the baseline impedance due to an increase in ionic mobility. However, sensor response did not vary within clinically relevant temperature and flow ranges. H2O2 plasma sterilization also had no effect on sensor performance. This low power and simple format sensor was developed with the intention of future integration into shunts for wireless monitoring of shunt state and more importantly, a more accurate and timely diagnosis of shunt failure.

  2. Parylene MEMS patency sensor for assessment of hydrocephalus shunt obstruction.

    PubMed

    Kim, Brian J; Jin, Willa; Baldwin, Alexander; Yu, Lawrence; Christian, Eisha; Krieger, Mark D; McComb, J Gordon; Meng, Ellis

    2016-10-01

    Neurosurgical ventricular shunts inserted to treat hydrocephalus experience a cumulative failure rate of 80 % over 12 years; obstruction is responsible for most failures with a majority occurring at the proximal catheter. Current diagnosis of shunt malfunction is imprecise and involves neuroimaging studies and shunt tapping, an invasive measurement of intracranial pressure and shunt patency. These patients often present emergently and a delay in care has dire consequences. A microelectromechanical systems (MEMS) patency sensor was developed to enable direct and quantitative tracking of shunt patency in order to detect proximal shunt occlusion prior to the development of clinical symptoms thereby avoiding delays in treatment. The sensor was fabricated on a flexible polymer substrate to eventually allow integration into a shunt. In this study, the sensor was packaged for use with external ventricular drainage systems for clinical validation. Insights into the transduction mechanism of the sensor were obtained. The impact of electrode size, clinically relevant temperatures and flows, and hydrogen peroxide (H2O2) plasma sterilization on sensor function were evaluated. Sensor performance in the presence of static and dynamic obstruction was demonstrated using 3 different models of obstruction. Electrode size was found to have a minimal effect on sensor performance and increased temperature and flow resulted in a slight decrease in the baseline impedance due to an increase in ionic mobility. However, sensor response did not vary within clinically relevant temperature and flow ranges. H2O2 plasma sterilization also had no effect on sensor performance. This low power and simple format sensor was developed with the intention of future integration into shunts for wireless monitoring of shunt state and more importantly, a more accurate and timely diagnosis of shunt failure. PMID:27589973

  3. 77 FR 58366 - Dominion South Pipeline Company, L.P.; Gulf Shore Energy Partners, LP; Notice of Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    .... Also on September 11, 2012, Gulf Shore, 333 Clay Street, Suite 4500, Houston, Texas 77002, file an... Partners, LP, 333 Clay Street, Houston, Texas 77002, by telephone at (713) 308-8117 or by email at...

  4. Bending characteristics of dual-hole PM-PCF based on LP01 and LP11 modal interference

    NASA Astrophysics Data System (ADS)

    Guo, Xuan; Liu, Feng; Gao, Meng-yuan; Tan, Ai-ling; Fu, Xing-hu; Bi, Wei-hong

    2016-03-01

    The bending characteristics of dual-hole polarization maintaining photonic crystal fiber (PM-PCF) are demonstrated in this paper. The modal interference is induced by the LP01 mode and LP11 mode propagating in a single PM-PCF with the same polarization direction. Simulation results demonstrate that the bending radius induces the phase difference between LP01 mode and LP11 mode, which leads to the change of light interference intensity on the fiber output facet. The relationship between bending radius and normalized interference intensity with three different bending angles is discussed, where the bending angle is defined as the angle between hole axis and the x axis. The bending sensitivity is obtained to be about -188.78/m around the bending radius of 1.5 cm with the bending angle of 90°. The bending characteristics can contribute for online bending detection in widespread areas.

  5. A Hybridized GA with LP-LP Model for the Management of Confined Groundwater.

    PubMed

    Khadem, M; Afshar, M H

    2015-01-01

    A novel hybrid methodology is introduced in this paper for the optimal solution of the groundwater management problem. The problem to be addressed is the optimal determination and operation of a predefined number of wells out of a priori known set of potential wells with fixed locations to minimize the pumping cost of utilizing a two-dimensional (2D) confined aquifer under steady-state flow condition. The solution to this problem should satisfy a downstream demand, a lower/upper bound on the pumping rates, and a lower/upper bound on the water level drawdown in the wells. The problem is solved by hybridizing a genetic algorithm (GA) which suggests the candidate configurations for the operational wells and a hybrid linear programming (LP-LP) approach with the duty of finding the optimal operation policy of the candidate wells defined by their pumping rates. Two different codings, namely binary and integer codings, are used for the GA and their performances are compared. The ability of the proposed hybrid method is tested against two benchmark problems: (1) finding the optimal configuration and pumping rates of a predefined number of wells out of potential wells and (2) finding the optimal number, configuration and pumping rates of the operating wells out of potential wells and the results are presented and compared with the available ones showing superior efficiency and effectiveness of the proposed method.

  6. Vascular collateralization along ventriculoperitoneal shunt catheters in moyamoya disease.

    PubMed

    Singla, Amit; Lin, Ning; Ho, Allen L; Scott, R Michael; Smith, Edward R

    2013-06-01

    Surgically created openings such as bur holes can serve as avenues for the development of collateral blood supply to the brain in patients with moyamoya disease. When such collateralization occurs through preexisting shunt catheter sites, the potential exists for perioperative stroke if these vessels are damaged during revision of a ventricular catheter for shunt malfunction. In this paper the authors report on a series of patients with a history of ventriculoperitoneal (VP) shunts who later developed moyamoya disease and were found to have spontaneous transdural collateral vessels at ventricular catheter sites readily visualized on diagnostic angiography. A consecutive surgical series of 412 patients with moyamoya disease treated at Boston Children's Hospital from 1990 to 2010 were reviewed to identify patients with concomitant moyamoya and a VP shunt. The clinical records and angiograms of these patients were reviewed to determine the extent of bur hole collaterals through the shunt site. Three patients were identified who had VP shunts placed for hydrocephalus and subsequently developed moyamoya disease. All 3 patients demonstrated spontaneous transdural collaterals at the ventricular catheter bur hole, as confirmed by angiography during the workup for moyamoya disease. No patients required subsequent revision of their ventricular catheters following the diagnosis of moyamoya. All patients have remained stroke free and clinically stable following pial synangiosis. Although the association of moyamoya and shunted hydrocephalus is rare, it may present a significant potential problem for the neurosurgeon treating a shunt malfunction in this patient population, because shunt bur holes may become entry sites for the ingrowth of significant cortical transdural collateral blood supply to the underlying brain. Shunt revision might therefore be associated with an increased risk of postoperative stroke or operative-site hemorrhage in this population if this

  7. Portosystemic Shunt Surgery in Patients with Idiopathic Noncirrhotic Portal Hypertension.

    PubMed

    Karagul, Servet; Yagci, Mehmet Ali; Tardu, Ali; Ertugrul, Ismail; Kirmizi, Serdar; Sumer, Fatih; Isik, Burak; Kayaalp, Cuneyt; Yilmaz, Sezai

    2016-01-01

    BACKGROUND Idiopathic noncirrhotic portal hypertension (INCPH) is a rare disease characterized by increased portal venous pressure in the absence of cirrhosis and other causes of liver diseases. The aim of the present study was to present our results in using portosystemic shunt surgery in patients with INCPH. MATERIAL AND METHODS Patients who had been referred to our Liver Transplantation Institute for liver transplantation and who had undergone surgery from January 2010 to December 2015 were retrospectively analyzed. Patients with INCPH who had undergone portosystemic shunt procedure were included in the study. Age, sex, symptoms and findings, type of portosystemic shunt, and postoperative complications were assessed. RESULTS A total of 1307 patients underwent liver transplantation from January 2010 to December 2015. Eleven patients with INCPH who did not require liver transplantation were successfully operated on with a portosystemic shunt procedure. The mean follow-up was 30.1±19 months (range 7-69 months). There was no mortality in the perioperative period or during the follow-up. Two patients underwent surgery again due to intra-abdominal hemorrhage; one had bleeding from the surgical site except the portacaval anastomosis and the other had bleeding from the h-graft anastomosis. No patient developed encephalopathy and no patient presented with esophageal variceal bleeding after portosystemic shunt surgery. Shunt thrombosis occurred in 1 patient (9.9%). Only 1 patient developed ascites, which was controlled medically. CONCLUSIONS Portosystemic shunt surgery is a safe and effective procedure for the treatment of patients with INCPH. PMID:27194018

  8. The hydrokinetic parameters of shunts for hydrocephalus might be inadequate.

    PubMed

    Sotelo, Julio

    2012-01-01

    Long-term treatment of hydrocephalus continues to be dismal. Shunting is the neurosurgical procedure more frequently associated with complications, which are mostly related with dysfunctions of the shunting device, rather than to mishaps of the rather simple surgical procedure. Overdrainage and underdrainage are the most common dysfunctions; of them, overdrainage is a conspicuous companion of most devices. Even when literally hundreds of different models have been proposed, developed, and tested, overdrainage has plagued all shunts for the last 60 years. Several investigations have demonstrated that changes in the posture of the subject induce unavoidable and drastic differences of intraventricular hydrokinetic pressure and cerebrospinal fluid (CSF) drainage through the shunt. Of all the parameters that participate in the pathophysiology of hydrocephalus, the only invariable one is cerebrospinal fluid production at a constant rate of approximately 0.35 ml/min. However, this feature has not been considered in the design of currently available shunts. Our experimental and clinical studies have shown that a simple shunt, whose drainage capacity complies with this unique parameter, would prevent most complications of shunting for hydrocephalus.

  9. Exploration of nonlinearly shunted piezoelectrics as vibration absorbers

    NASA Astrophysics Data System (ADS)

    Zhou, B.; Zang, C.; Wang, X.

    2016-09-01

    Practical realization of a nonlinearly shunted piezoelectric vibration absorber is numerically explored in this research. It is widely known that the linear resonant piezoelectric shunting strategy, acting as a tuned mass damper, is limited by the massive inductance required in low-frequency cases and sensitivity to drifts in structural frequencies. In order to overcome this limitation, a nonlinear piezoelectric shunting strategy is proposed based on the nonlinear energy sink theory. The essential idea is to passively absorb vibrational energy from the host structure through the intentional use of nonlinearity in piezoelectric shunting. The nonlinearly shunted piezoelectrics are supposed to work over a broad frequency band with a smaller inductance requirement compared with the linear resonant shunting. The nonlinearly shunted piezoelectric vibration absorber is built and applied in a cantilevered beam. Major challenges coming from the nonlinear tuning design for an effective vibration absorber exempted from high isolated response curves will be covered in this research. This numerical study is supposed to pave the way for experimental investigations that are currently in process.

  10. Shunt malfunction presenting with symptomatic syringomyelia: Demonstrated on contrast ventriculogram

    PubMed Central

    Aniruddha, T. J; Pruthi, Nupur

    2014-01-01

    Ventriculoperitoneal (VP) shunt malfunction commonly presents as raised intracranial pressure. Rarely, when the central canal of the spinal cord communicates with the 4th ventricle, shunt malfunction can present as an expanding syrinx. The diagnosis is often delayed, resulting in severe morbidity. Some of these patients undergo repeated syrinx surgeries without much benefits. We report a case of chronic tuberculous meningitis with shunt malfunction presenting as an expanding spinal canal syrinx and quadriparesis. Fourth ventricular communication with syrinx was demonstrated with the help of a contrast ventriculogram. After shunt revision, syrinx resolved completely and the patient made significant improvement in his neurological deficits. The present case illustrates that a historical and rarely used investigation like contrast ventriculogram aids in the diagnosis and management even in the current neurosurgical practice. All patients with late onset syrinx and a previous VP shunt need to be investigated for shunt malfunction before considering syrinx surgery. A simple shunt revision resolves the syrinx in such conditions and avoids more complex procedures like Foramen magnum decompression. Relevant literature has been reviewed; pathophysiology and management options have been discussed. PMID:25250067

  11. The hydrokinetic parameters of shunts for hydrocephalus might be inadequate.

    PubMed

    Sotelo, Julio

    2012-01-01

    Long-term treatment of hydrocephalus continues to be dismal. Shunting is the neurosurgical procedure more frequently associated with complications, which are mostly related with dysfunctions of the shunting device, rather than to mishaps of the rather simple surgical procedure. Overdrainage and underdrainage are the most common dysfunctions; of them, overdrainage is a conspicuous companion of most devices. Even when literally hundreds of different models have been proposed, developed, and tested, overdrainage has plagued all shunts for the last 60 years. Several investigations have demonstrated that changes in the posture of the subject induce unavoidable and drastic differences of intraventricular hydrokinetic pressure and cerebrospinal fluid (CSF) drainage through the shunt. Of all the parameters that participate in the pathophysiology of hydrocephalus, the only invariable one is cerebrospinal fluid production at a constant rate of approximately 0.35 ml/min. However, this feature has not been considered in the design of currently available shunts. Our experimental and clinical studies have shown that a simple shunt, whose drainage capacity complies with this unique parameter, would prevent most complications of shunting for hydrocephalus. PMID:22530174

  12. The hydrokinetic parameters of shunts for hydrocephalus might be inadequate

    PubMed Central

    Sotelo, Julio

    2012-01-01

    Long-term treatment of hydrocephalus continues to be dismal. Shunting is the neurosurgical procedure more frequently associated with complications, which are mostly related with dysfunctions of the shunting device, rather than to mishaps of the rather simple surgical procedure. Overdrainage and underdrainage are the most common dysfunctions; of them, overdrainage is a conspicuous companion of most devices. Even when literally hundreds of different models have been proposed, developed, and tested, overdrainage has plagued all shunts for the last 60 years. Several investigations have demonstrated that changes in the posture of the subject induce unavoidable and drastic differences of intraventricular hydrokinetic pressure and cerebrospinal fluid (CSF) drainage through the shunt. Of all the parameters that participate in the pathophysiology of hydrocephalus, the only invariable one is cerebrospinal fluid production at a constant rate of approximately 0.35 ml/min. However, this feature has not been considered in the design of currently available shunts. Our experimental and clinical studies have shown that a simple shunt, whose drainage capacity complies with this unique parameter, would prevent most complications of shunting for hydrocephalus. PMID:22530174

  13. 77 FR 58371 - Allegheny Hydro No. 8, L.P., Allegheny Hydro No. 9, L.P., and U.S. Bank National Association...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... Energy Regulatory Commission Allegheny Hydro No. 8, L.P., Allegheny Hydro No. 9, L.P., and U.S. Bank National Association Allegheny Hydro, LLC; Notice of Application for Transfer of License, and Soliciting Comments and Motions To Intervene On August 31, 2012, Allegheny Hydro No. 8, L.P., Allegheny Hydro No. 9,...

  14. Atrial-caval shunting (ACS) after trauma.

    PubMed

    Kudsk, K A; Sheldon, G F; Lim, R C

    1982-02-01

    Since 1968 the atrial-caval shunt (ACS), along with inflow occlusion at the porta hepatis, has been used at San Francisco General Hospital in 18 trauma patients to control massive hemorrhage from the inferior vena cava, hepatic veins, or liver. Thirteen patients died from irreversible shock. Five patients survived their initial injuries; one of them died 45 days later from the complications of shock and sepsis. No patients survived who sustained blunt trauma and were admitted in cardiac arrest. Only one of ten patients with BP less than 70 mm Hg after resuscitation survived, whereas four of eight with BP greater than 70 mm Hg survived. ACS was used to control caval injuries in seven patients (one survivor), severe hepatic parenchymal fractures in four patients (two survivors), and combined hepatic and caval injuries in seven patients (two survivors). Survivors had an average of 5.75 associated injuries; nonsurvivors had 3.8. No complications of ACS occurred in the surviving patients.

  15. 49 CFR 236.309 - Loss of shunt protection; where required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Loss of shunt protection; where required. 236.309... Standards § 236.309 Loss of shunt protection; where required. (a) A loss of shunt of 5 seconds or less shall not permit an established route to be changed at an automatic interlocking. (b) A loss of shunt of...

  16. Return to the emergency department after ventricular shunt evaluation.

    PubMed

    Sarda, Samir; Simon, Harold K; Hirsh, Daniel A; Wang, Andrew; Shane Tubbs, R; Chern, Joshua J

    2016-04-01

    OBJECT Patients with CSF shunts are medically complex and frequently present to the emergency department (ED) with suspected shunt malfunction. After adequate evaluation in the ED and proper disposition, some patients return to the ED within a short period of time. In this study, the authors examined the reasons for ED revisits within 7 days of the index ED visit to discern possible preventable returns. METHODS There were 3080 index ED visits made by patients with shunted hydrocephalus between 2010 and 2013. Index ED visits preceded by another ED visit or neurosurgical procedure within 60 days were excluded. Index ED visits for reasons unrelated to shunt function and those that led directly to admissions and shunt revision surgeries were also excluded. The remaining 1509 ED visits were eligible for analysis in this study. Final dispositions from the index ED visit included home (1176 cases), admission to the neurosurgery service for observation (134 cases), and admission to other services (199 cases). Subsequent events within 7 days, including ED revisits, hospital admissions, and shunt-related surgery were recorded, and reasons for the ED revisits were categorized based on whether the visit was related to shunt function concerns. Clinical and socioeconomic factors were analyzed for their association with ED revisits by using statistical methods. RESULTS Of the 1176 patients discharged home from the ED after shunt function evaluation, 101 (8.6%) returned to the ED within 7 days. Of the 134 patients admitted to the neurosurgery service for observation only, 8 (6.0%) returned to the ED within 7 days of discharge. Of the 199 patients admitted to hospital services other than neurosurgery, 13 (6.5%) returned to the ED within 7 days of discharge. The reasons for ED revisits vary (total of 122 visits combining the 3 groups), but at least 60% of the revisits were clearly unrelated to shunt function. A younger age, daytime arrival to the ED, and living within the

  17. [Abdominal pseudocyst as a complication of ventriculoperitoneal shunt].

    PubMed

    Shakir, Shawnim; Hegelund, Sture

    2013-09-16

    The abdominal pseudocyst is an unfrequent complication in patients with ventriculoperitoneal shunts. Although many cases have been reported in children, it is rare in adult patients. However, a 47-year-old man with congenital hydrocephalus who had been treated with ventriculoperitoneal shunt since the age of three months, was admitted to hospital due to abdominal pain. He was eventually diagnosed radiologically as having an abdominal pseudocyst. Despite this complication being rare, especially in adults, it should be highly suspected whenever an abdominal cyst co-occurs with a ventriculoperitoneal shunt.

  18. Ion beam sputter-etched ventricular catheter for hydrocephalus shunt

    NASA Technical Reports Server (NTRS)

    Banks, B. A. (Inventor)

    1983-01-01

    A cerebrospinal fluid shunt in the form of a ventricular catheter for controlling the condition of hydrocephalus by relieving the excessive cerebrospinal fluid pressure is described. A method for fabrication of the catheter and shunting the cerebral fluid from the cerebral ventricles to other areas of the body is also considered. Shunt flow failure occurs if the ventricle collapse due to improper valve function causing overdrainage. The ventricular catheter comprises a multiplicity of inlet microtubules. Each microtubule has both a large openings at its inlet end and a multiplicity of microscopic openings along its lateral surfaces.

  19. Pollutants removal in subsurface infiltration systems by shunt distributing wastewater with/without intermittent aeration under different shunt ratios.

    PubMed

    Pan, Jing; Yuan, Fang; Zhang, Yang; Huang, Linli; Yu, Long; Zheng, Fanping; Cheng, Fan; Zhang, Jiadi

    2016-10-01

    Matrix dissolved oxygen (DO), removal of COD, TP and nitrogen in subsurface infiltration systems (SISs), named SIS A (without intermittent aeration and shunt distributing wastewater), SIS B (with shunt distributing wastewater) and SIS C (with intermittent aeration and shunt distributing wastewater) were investigated. Aerobic conditions were developed in 50cm depth and anoxic or anaerobic conditions were not changed in 80 and 110cm depth by intermittent aeration. Under appropriate shunt ratios, shunt distributing wastewater improved denitrification and had little influence on COD, TP and NH3-N removal. Under the optimal shunt ratio of 1:2 for SIS C, high average removal rates of COD (90.06%), TP (93.17%), NH3-N (88.20%) and TN (85.79%) were obtained, which were higher than those in SIS A (COD: 82.56%, TP: 92.76%, NH3-N: 71.08%, TN: 49.24%) and SIS B (COD: 81.12%, TP: 92.58%, NH3-N: 69.14%, TN: 58.73%) under the optimal shunt ratio of 1:3.

  20. LP DAAC and MEaSUREs - Optimizing Collection Inception

    NASA Astrophysics Data System (ADS)

    Bennett, S.

    2013-12-01

    The Land Processes Distributed Active Archive Center (LP DAAC) is a selected NASA Earth Observing System (EOS) Data and Information System (EOSDIS) DAAC supporting the Making Earth System Data Records for Use in Research Environments (MEaSUREs) Program to contribute in providing long-term, consistent, and mature data products. The LP DAAC has identified three essential components for the MEaSUREs collection inception. The first component includes a framework of LP DAAC's data lifecycle including overall inception of products, curation of products, and long-term archiving of products. The second component fuses data producer and data provider operations, interleaving key personnel into key processes throughout the project. The third component integrates and evolves stakeholder elements into a standard methodology, alongside affording an overall homogeneous data delivery system for MEaSUREs collections. As an active participant on the Metadata Evolution for NASA Data Systems (MENDS) Tiger Team, the LP DAAC is working to categorize all data model elements into the ISO 19115 international metadata standard. This poster depicts how each of these three components optimizes the LP DAAC MEaSUREs collection inception process.

  1. A neonate with a meningomyelocele complicated by Aeromonas caviae ventriculoperitoneal shunt infection.

    PubMed

    den Butter, C P; Mahieu, L M

    2013-01-01

    We report on a newborn girl with a Aeromonas caviae shunt infection and meningitis after insertion of a ventriculoperitoneal shunt and surgical repair of a meningomyelocele in one procedure. This pathogen has never been reported, related to ventriculoperitoneal shunt infections. Beside the need for surgical revision of the shunt because of shunt obstruction and septa formation in the ventricles, the clinical outcome was good with intravenous cefotaxime therapy.

  2. Sparse logistic regression with Lp penalty for biomarker identification.

    PubMed

    Liu, Zhenqiu; Jiang, Feng; Tian, Guoliang; Wang, Suna; Sato, Fumiaki; Meltzer, Stephen J; Tan, Ming

    2007-01-01

    In this paper, we propose a novel method for sparse logistic regression with non-convex regularization Lp (p <1). Based on smooth approximation, we develop several fast algorithms for learning the classifier that is applicable to high dimensional dataset such as gene expression. To the best of our knowledge, these are the first algorithms to perform sparse logistic regression with an Lp and elastic net (Le) penalty. The regularization parameters are decided through maximizing the area under the ROC curve (AUC) of the test data. Experimental results on methylation and microarray data attest the accuracy, sparsity, and efficiency of the proposed algorithms. Biomarkers identified with our methods are compared with that in the literature. Our computational results show that Lp Logistic regression (p <1) outperforms the L1 logistic regression and SCAD SVM. Software is available upon request from the first author. PMID:17402921

  3. Malignant cause of ventriculoperitoneal shunt 'pseudocyst': a case report.

    PubMed

    Awori, Jonathan; Wu, Chris Y; Maher, Cormac O

    2015-01-01

    Abdominal pseudocysts are an uncommon complication of ventriculoperitoneal (VP) shunts. We present the case of a 4-year-old boy with a history of complicated hydrocephalus managed with a VP shunt due to sequelae of prematurity. The patient presented with abdominal distention, and a pseudocyst was diagnosed. Despite shunt externalization and aspiration, the pseudocyst continued to produce up to 1 liter of serosanguineous fluid per day. After MRI revealed malignant features within the pseudocyst, laparotomy was performed and the pseudocyst was partially excised. Pathology reports suggested sarcoma. The cystic mass grew back aggressively, accompanied by distant metastasis. The patient's condition deteriorated and he died from his disease. To our knowledge, this represents the first report of an abdominal malignancy mimicking a pseudocyst and causing VP shunt failure.

  4. Zero tolerance to shunt infections: can it be achieved?

    PubMed Central

    Choksey, M; Malik, I

    2004-01-01

    Objective: To evaluate the rigid application of a technique of shunt placement aimed at the eradication of postoperative shunt infection in neurosurgical practice. Method: All shunt procedures were performed or closely supervised by the senior author (MSC). The essentials were the use of intravenous peri- and postoperative antimicrobials, rigid adherence to classical aseptic technique, liberal use of topical antiseptic (Betadine®), and avoidance of haematomas. Results: Of 176 operations, 93 were primary procedures; 33 patients underwent revisions, some multiple. Only one infection occurred, seven months postoperatively, secondary to appendicitis with peritonitis. The infecting Streptococcus faecalis appeared to ascend from the abdominal cavity. Conclusion: A rigidly applied protocol and strict adherence to sterile technique can reduce shunt infections to a very low level. PMID:14707314

  5. Should transjugular intrahepatic portosystemic shunt stent grafts be underdilated?

    PubMed

    Gaba, Ron C; Parvinian, Ahmad; Minocha, Jeet; Casadaban, Leigh C; Knuttinen, M Grace; Ray, Charles E; Bui, James T

    2015-03-01

    Although underdilation of transjugular intrahepatic portosystemic shunt (TIPS) stent grafts is commonly performed to limit complications arising from excessive portosystemic shunting, it is uncertain whether underdilated stents retain their smaller diameter indefinitely or eventually expand to nominal caliber. In this investigation, postprocedure computed tomography (CT) was used to compare diameters of underdilated TIPSs and TIPSs expanded to a nominal diameter of 10 mm in 61 cases. The groups had comparable shunt diameters on post-TIPS imaging (9.8 mm vs 9.9 mm; P = .079), with similar incidences of hepatic encephalopathy (34% vs 20%; P = .372), indicating stent self-expansion over time, and bringing into question the advantages of underdilation for customization of shunt caliber.

  6. Percutaneous ultrasound-guided insertion of ventriculo-atrial shunts.

    PubMed

    McCracken, James Albert; Bahl, Anuj; McMullan, John

    2016-08-01

    Ventriculo-atrial (VA) shunts have been in use for >60 years but less frequently so of late. This is due to a combination of the risk of cardiac complications, lack of expertise and a lengthy operation. We present our consecutive prospective series of 10 VA shunts inserted using a percutaneous method employing the Sonowand Invite™ neuronavigation system for both the distal and proximal catheters, over a 13-month period. We had two complications of cases needing revision, but our series highlights a safe and reproducible method of inserting a VA shunt. About 30% of the procedures were carried out by a trainee as the primary surgeon. This technique does not necessarily require the expertise of a complex hydrocephalus surgeon and is thus able to be in the armoury of any neurosurgeon needing to do a VA shunt procedure. The indications, operative data and outcomes of our patients are discussed.

  7. Shunting inhibitory cellular neural networks with chaotic external inputs

    NASA Astrophysics Data System (ADS)

    Akhmet, M. U.; Fen, M. O.

    2013-06-01

    Taking advantage of external inputs, it is shown that shunting inhibitory cellular neural networks behave chaotically. The analysis is based on the Li-Yorke definition of chaos. Appropriate illustrations which support the theoretical results are depicted.

  8. Shunting inhibitory cellular neural networks with chaotic external inputs.

    PubMed

    Akhmet, M U; Fen, M O

    2013-06-01

    Taking advantage of external inputs, it is shown that shunting inhibitory cellular neural networks behave chaotically. The analysis is based on the Li-Yorke definition of chaos. Appropriate illustrations which support the theoretical results are depicted.

  9. Routine cerebrospinal fluid analysis during 'de novo' ventriculoperitoneal shunt insertion: Single Institution Experience.

    PubMed

    Khalil, Ayman; Mandiwanza, Tafadzwa; Zakaria, Zaitun; Crimmins, Darach

    2016-08-01

    Background Cerebrospinal fluid (CSF) sampling is performed during ventriculoperitoneal (VP) shunting procedure surgery for early detection of infection. We have performed a retrospective study to determine whether routine intraoperative CSF sampling at new VP shunt insertion has predicted shunt infection or changed subsequent surveillance or management. Method From January 2011 to December 2013, 99 patients underwent first time VP shunt insertion at our hospital. The data collected from Beaumont Hospital Information System and operating theatre logbook. The reviewed data were patient demographics, the clinical condition requiring VP shunt procedure, shunt type, date of VP shunt insertion, date of VP shunt infection or malfunction and laboratory data. Results A first time VP shunt insertion procedure was performed in 99 patients. During the VP shunt insertion procedure, 64 patients had CSF sampling for microbiological analysis. The CSF culture was negative in all samples. All patients were followed up for 12 months. During the follow-up period, a total of 15 patients underwent VP shunt revision. Three of the shunt revisions were secondary to infection. The three infected shunt cases had sterile CSF cultures at the time of insertion. Conclusion There appears to be no correlation between CSF sampling during first time VP shunt insertion and the later development VP shunt infection. This questions the need for routine CSF sampling at the time of insertion. This would be confirmed as a part of future randomised trials.

  10. In vitro flow measurements in ion sputtered hydrocephalus shunts

    NASA Technical Reports Server (NTRS)

    Cho, Y. I.; Back, L. H.

    1989-01-01

    This paper describes an experimental procedure for accurate measurements of the pressure-drop/flow rate relationship in hydrocephalus shunts. Using a fish-hook arrangement, small flow rates in a perforated ion-sputtered Teflon microtubule were measured in vitro in a pressured system and were correlated with pressure in the system. Results indicate that appropriate drainage rates could be obtained in the physiological range for hydrocephalus shunts.

  11. Ventriculo-peritoneal shunt infection in a patient on hemodialysis.

    PubMed

    Thet, Yupar; Myint, Win; Myint, Wynne; Hughes, David; Crowe, Alex V; Banerjee, Anindya

    2008-07-01

    Sepsis is an important and serious complication in hemodialysis (HD) patients. Here we report on a case of spina bifida with ventriculo-peritoneal (VP) shunt infection who was on HD and underwent at least 5 months of investigations before a source of the infection was found and eventually treated successfully. We believe this to be the first reported case of VP shunt-associated sepsis in a patient on HD.

  12. Hearing Loss in Patients with Shunt-Treated Hydrocephalus.

    PubMed

    Panova, Margarita V; Geneva, Ina E; Madjarova, Kalina I; Bosheva, Miroslava N

    2015-01-01

    Hearing loss is a common manifestation of the long-term complications in patients with shunt treated hydrocephalus along with motor development disturbance, cognitive and visual impairment, epilepsy and endocrine disorders. The aim of the present study was to investigate the alterations of hearing in patients with shunt treated hydrocephalus of non-tumor etiology and at least one year after implantation of ventriculo-peritoneal shunt, as well as their impact on the quality of life of patients. The study included 70 patients (age range 1.25 years - 21.25 years) with shunted non-tumor hydrocephalus and at least one year after placement of the shunt system. Hearing alterations were proved by measuring the brainstem auditory evoked potentials (BAEP) for children up to 5 years of age and children with mental retardation; audiograms was used for children older than 5 years with normal neuro-psychological development (NPD). Of the 70 studied patients 17 (24%) had hearing loss (10 bilateral and 7-unilateral) and all of them had sensorineural hearing loss, which is associated with low weight at birth, posthemorrhagic hydrocephalus and brainstem symptoms at the time of diagnosis of hydrocephalus. Hearing pathology was found more often in shunt-treated patients with NPD retardation, poor functional status and low quality of life. Children with shunt-treated hydrocephalus have hearing loss of sensorineural type. Children with brain stem symptomatology at diagnosing hydrocephalus and children with post-hemorrhagic hydrocephalus show higher risk of hearing loss. Children with shunted hydrocephalus and hearing loss show lower NPD, lower quality of life and lower functional status.

  13. Hearing Loss in Patients with Shunt-Treated Hydrocephalus.

    PubMed

    Panova, Margarita V; Geneva, Ina E; Madjarova, Kalina I; Bosheva, Miroslava N

    2015-01-01

    Hearing loss is a common manifestation of the long-term complications in patients with shunt treated hydrocephalus along with motor development disturbance, cognitive and visual impairment, epilepsy and endocrine disorders. The aim of the present study was to investigate the alterations of hearing in patients with shunt treated hydrocephalus of non-tumor etiology and at least one year after implantation of ventriculo-peritoneal shunt, as well as their impact on the quality of life of patients. The study included 70 patients (age range 1.25 years - 21.25 years) with shunted non-tumor hydrocephalus and at least one year after placement of the shunt system. Hearing alterations were proved by measuring the brainstem auditory evoked potentials (BAEP) for children up to 5 years of age and children with mental retardation; audiograms was used for children older than 5 years with normal neuro-psychological development (NPD). Of the 70 studied patients 17 (24%) had hearing loss (10 bilateral and 7-unilateral) and all of them had sensorineural hearing loss, which is associated with low weight at birth, posthemorrhagic hydrocephalus and brainstem symptoms at the time of diagnosis of hydrocephalus. Hearing pathology was found more often in shunt-treated patients with NPD retardation, poor functional status and low quality of life. Children with shunt-treated hydrocephalus have hearing loss of sensorineural type. Children with brain stem symptomatology at diagnosing hydrocephalus and children with post-hemorrhagic hydrocephalus show higher risk of hearing loss. Children with shunted hydrocephalus and hearing loss show lower NPD, lower quality of life and lower functional status. PMID:27180348

  14. Small bowel perforation: a rare complication of ventriculoperitoneal shunt placement

    PubMed Central

    Bourm, Kelsey; Pfeifer, Cory; Zarchan, Adam

    2016-01-01

    Small bowel perforation is a rare complication of ventriculoperitoneal (VP) shunt placement. When seen, it most commonly affects the stomach or colon. We describe a case and image findings of an 8-year-old female who presented with sepsis and erosion of the VP shunt into the small bowel. The imaging findings were confirmed surgically. We also provide an overview of the current literature discussing previously reported cases, clinical features, and treatment.

  15. Design of an intelligent and personalised shunting system for hydrocephalus.

    PubMed

    Momani, Lina; Alkharabsheh, Abdel Rahman; Al-Nuaimy, Waleed

    2008-01-01

    Hydrocephalus is a neurological disease that manifests itself in an elevated fluid pressure within the brain, and if left untreated, may be fatal. It is currently treated using shunt implants, which consist of a mechanical valve and tubes that regulate the pressure of cerebrospinal fluid (CSF) by draining excess fluid into the abdomen. Hydrocephalus shunting systems are no longer expected simply to regulate the intracranial pressure (ICP), but also to offer the option of regaining independence of the shunt. Additionally, they could offer personalised valve management which is one of the main limitations of current shunts. This paper describes the design of a multi-agent system for an intelligent and personalised CSF management system. Patient feedback and intracranial pressure readings will play important roles in the process of CSF regulation and weaning, introduces an element of personalisation to the treatment. The new shunting system would deliver both reactive and goal-driven solutions for the treatment, at the same time the intelligent part of the system will be monitoring how well the shunt is performing. These tasks can be achieved by implementing an agent approach in designing this system. Such system would help us to understand more about the dynamics of hydrocephalus.

  16. First Report of Ventriculoperitoneal Shunt Infection due to Cyberlindnera fabianii

    PubMed Central

    Baghdadi, Jonathan; Hemarajata, Peera; Humphries, Romney; Kelesidis, Theodoros

    2015-01-01

    Fungal infections in the central nervous system (CNS) are associated with significant morbidity and death. Transient fungemia in immunocompetent patients without any other risk factors for fungemia has been suggested as a possible mechanism that may lead to serious fungal ventriculoperitoneal (VP) shunt infections, but evidence is lacking. The clinical spectrum, diagnosis, and optimal therapy of Cyberlindnera fabianii infections remain to be determined. We describe the first case of CNS infection due to C. fabianii that occurred in an immunocompetent adult with a VP shunt. Spontaneous translocation with yeast that is not part of the normal gastrointestinal flora in the setting of ingestion of multiple servings of a fermentation product was the likely source from which Cyberlindnera fabianii gained entrance into the VP shunt system, causing meningitis in this patient. The authors conclude that, in view of the high morbidity associated with yeast infection of the CNS, long-term antifungal therapy should be strongly considered in cases where the VP shunt cannot be completely removed. Transient fungemia may lead to invasive disease in an immunocompetent host with VP shunt, even in the absence of any other risk factors for fungemia and even after remote placement of the VP shunt. PMID:26618013

  17. Shunt switched resistor regulator with diode snubber

    SciTech Connect

    Ekstrand, J.

    1989-03-21

    This patent describes a shunt switched resistor regulator power supply for supplying a variable amount of power to a load comprising: a rectifier means for accepting AC input voltage and converting it to DC output voltage at a positive and a negative terminal; first, second, third, and fourth nodes wherein the first and the fourth nodes are coupled to the positive and negative terminals, respectively; a current limiting resistor coupled between the first and second nodes; a capacitor coupled between the second and fourth nodes; a resistor having parasitic inductance coupled between the second and third nodes; a switch coupled between the third and fourth nodes; and a diode having its anode coupled to the third node and having its cathode coupled to the second node; means coupled to the load terminals for sensing the power being delivered to the load and for controlling the switch to have a duty cycle which results in the desired load current flowing through and a desired voltage appearing across the load in accordance with control input signals received at a control input.

  18. [A case of repeated shunt malfunctions with eosinophilic meningitis caused by silicone allergy].

    PubMed

    Kambara, Mizuki; Miyazaki, Takeshi; Yoshikane, Tsutomu; Sugimoto, Keiji; Akiyama, Yasuhiko

    2014-12-01

    The ventricular-peritoneal shunt for hydrocephalus is a well-known and established method but is sometimes complicated by shunt malfunction due to several causes. Eosinophilic meningitis is a rare disease, but has occasionally been reported as a cause of shunt malfunction. Here, we report the case of a 74-year-old woman with repeated shunt malfunction and eosinophilic meningitis due to a silicone allergy. Originally, the patient received a ventricular-peritoneal shunt for normal pressure hydrocephalus secondary to subarachnoid hemorrhage. However, shunt malfunction was identified 6 weeks later, and the first shunt revision was performed using a new shunt system from a different company. Further evaluation to identify the cause of the shunt malfunction revealed no abnormal findings, except for eosinophilia in the serum and cerebrospinal fluid. A second shunt malfunction was identified 16 weeks after the first shunt revision. We therefore concluded that eosinophilic meningitis caused by a silicone allergy might be the real culprit and a second shunt revision was performed using a silicone "extracted" tube. Since then, the patient's course has been free from shunt malfunction. In this case, the serum and cerebrospinal fluid eosinophilia were useful markers for identifying the cause of repeated shunt malfunctions. The silicone "extracted" tube may be helpful for diagnosis and therapy.

  19. Temporary arterial shunts to maintain limb perfusion after arterial injury: an animal study

    NASA Technical Reports Server (NTRS)

    Dawson, D. L.; Putnam, A. T.; Light, J. T.; Ihnat, D. M.; Kissinger, D. P.; Rasmussen, T. E.; Bradley, D. V. Jr

    1999-01-01

    BACKGROUND: Temporary shunt placement can quickly restore perfusion after extremity arterial injury. This study examined the adequacy of limb blood flow with shunt use, non-heparin-bonded shunt patency over prolonged periods, and the safety of this technique. METHODS: Common iliac arteries were divided and 4.0-mm Silastic Sundt shunts placed in 16 anesthetized pigs. Eight (group I) had shunts placed immediately; eight others (group II) were shunted after an hour of limb ischemia and hemorrhagic shock. Physiologic parameters and femoral artery blood flow in both hindlimbs were continuously monitored. Limb lactic acid generation, oxygen utilization, and hematologic and metabolic effects were serially evaluated for 24 hours. RESULTS: Shunts remained patent in 13 of 16 pigs. Shunts thrombosed in two group I animals because of technical errors, but functioned well after thrombectomy and repositioning. Patency could not be maintained in one animal that died from shock. Flow in group I shunted limbs was 57 (+/-11 SD) % of control. For group II animals in shock, shunted limb flow initially averaged 46 +/- 15% of control, but 4 hours after shunt placement, the mean limb blood flow was the same as in group I. Increased oxygen extraction compensated for the lower flow. Lactic acid production was not increased in comparison to control limbs. CONCLUSION: Shunts provided adequate flow in this model of extremity trauma. Correctly placed shunts stayed patent for 24 hours, without anticoagulation, if shunt placement followed resuscitation.

  20. 78 FR 12048 - Gulf Shore Energy Partners, LP; Notice of Abbreviated Application for Limited Amendment to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-21

    ... Energy Regulatory Commission Gulf Shore Energy Partners, LP; Notice of Abbreviated Application for Limited Amendment to Certificate of Public Convenience and Necessity On February 11, 2013, Gulf Shore Energy Partners, LP (``Gulf Shore''), filed an abbreviated application for limited amendment...

  1. 77 FR 38128 - Withdrawal of TORP Terminal LP, Bienville Offshore Energy Terminal Liquefied Natural Gas (LNG...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-26

    ... Maritime Administration Withdrawal of TORP Terminal LP, Bienville Offshore Energy Terminal Liquefied... Terminal LP's (TORP) withdrawal of the deepwater port license application for the proposed Bienville Offshore Energy Terminal (BOET). All actions related to the processing and agency coordination...

  2. 75 FR 38514 - Application to Export Electric Energy; Brookfield Energy Marketing LP

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-02

    ... Application to Export Electric Energy; Brookfield Energy Marketing LP AGENCY: Office of Electricity Delivery and Energy Reliability, DOE. ACTION: Notice of application. SUMMARY: Brookfield Energy Marketing LP... power marketing agencies and other entities within the United States. The existing...

  3. 75 FR 45611 - Texas Eastern Transmission LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-03

    ... Energy Regulatory Commission Texas Eastern Transmission LP; Notice of Application July 27, 2010. Take notice that on July 15, 2010, Texas Eastern Transmission (Texas Eastern), P.O. Box 1642, Houston, Texas... enable Texas Eastern to provide up to 112,000 dekatherms per day (Dth/d) of firm lateral...

  4. Fire Service Training. LP and Compressed Gas Emergencies.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Community Colleges, Raleigh.

    Part of a series of instructional outlines intended for use in a training program for firemen with no previous formal training, this curriculum guide discusses safety precautions for liquefied petroleum (LP) and compressed gas emergencies. During its twelve hours of instruction it covers (1) terminology; (2) the chemical composition of the gases;…

  5. 78 FR 48668 - Kalaeloa Partners, LP; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-09

    ..., Kalaeloa Partners, L.P. (Kalaeloa) filed a petition for recertification as a qualifying cogeneration... cogeneration facility operating and efficiency standard requirements for its facility for year 2013. Any person...://www.ferc.gov , using the ``eLibrary'' link and is available for review in the Commission's...

  6. 78 FR 64933 - Texas Eastern Transmission, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-30

    ..., for a certificate of public convenience and necessity to construct its Emerald Longwall Mine Panel D1... Emerald Coal Resources, LP (Emerald) in Greene County, Pennsylvania in Panel D1 of Emerald's mine, ground...Support@ferc.gov or call toll-free, (886) 208-3676 or TYY, (202) 502-8659. Any questions regarding...

  7. US EPA Testing of LP & MP UV Disinfection Technologies

    EPA Science Inventory

    Presentation will discuss the ongoing USEPA research on UV disinfection addressing the following objectives: Conservatively predict log inactivation and RED of adenovirus with surrogates; Conduct many (LP=61) UV reactor conditions challenged with Ad2, B. pumilus, and MS2 & conduc...

  8. The right-to-left shunt of crocodilians serves digestion.

    PubMed

    Farmer, C G; Uriona, T J; Olsen, D B; Steenblik, M; Sanders, K

    2008-01-01

    Abstract All amniotes except birds and mammals have the ability to shunt blood past the lungs, but the physiological function of this ability is poorly understood. We studied the role of the shunt in digestion in juvenile American alligators in the following ways. First, we characterized the shunt in fasting and postprandial animals and found that blood was shunted past the lungs during digestion. Second, we disabled the shunt by surgically sealing the left aortic orifice in one group of animals, and we performed a sham surgery in another. We then compared postprandial rates of gastric acid secretion at body temperatures of 19 degrees and 27 degrees C and rates of digestion of bone at 27 degrees C. Twelve hours after eating, maximal rates of gastric acid secretion when measured at 19 degrees and 27 degrees C were significantly less in the disabled group than in sham-operated animals. Twenty-four hours postprandial, a significant decrease was found at 27 degrees C but not at 19 degrees C. For the first half of digestion, dissolution of cortical bone was significantly slower in the disabled animals. These data suggest the right-to-left shunt serves to retain carbon dioxide in the body so that it can be used by the gastrointestinal system. We hypothesize that the foramen of Panizza functions to enrich with oxygen blood that is destined for the gastrointestinal system to power proton pumps and other energy-demanding processes of digestion and that the right-to-left shunt serves to provide carbon dioxide to gastrointestinal organs besides the stomach, such as the pancreas, spleen, upper small intestine, and liver.

  9. 78 FR 53487 - Equinox Funds Trust and Equinox Institutional Asset Management LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... COMMISSION Equinox Funds Trust and Equinox Institutional Asset Management LP; Notice of Application August 23... requirements. Applicants: Equinox Funds Trust (the ``Trust'') and Equinox Institutional Asset Management LP.... Applicants: Phillip Liu, Equinox Institutional Asset Management LP, 47 Hulfish Street, Suite 510,...

  10. 78 FR 46388 - NGAM Advisors, L.P., et al.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-31

    ... COMMISSION NGAM Advisors, L.P., et al.; Notice of Application July 25, 2013. AGENCY: Securities and Exchange... Advisors, L.P. (the ``Adviser''), Natixis ETF Trust (the ``Trust'') and NGAM Distribution, L.P. Filing... mail. Hearing requests should be received by the Commission by 5:30 p.m. on August 19, 2013 and...

  11. 75 FR 74029 - Sabine Pass LNG, L.P.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-30

    ... Energy Regulatory Commission Sabine Pass LNG, L.P.; Notice of Application November 22, 2010. Take notice that on November 12, 2010, Sabine Pass LNG, L.P. (Sabine Pass), 700 Milam Street, Suite 800, Houston... directed to Patricia Outtrim, Sabine Pass LNG, L.P., 700 Milam Street, Suite 800, Houston, Texas 77002,...

  12. 77 FR 53885 - Jordan Cove Energy Project LP, Pacific Connector Gas Pipeline LP; Notice of Extension of Comment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-04

    ... Extension of Comment Period and Additional Public Scoping Meetings for the Jordan Cove Liquefaction and... comment period for Jordan Cove Energy Project LP's (Jordan Cove) proposed liquefaction project in Coos... Liquefaction and Pacific Connector Pipeline Projects, Requests for Comments on Environmental Issues, and...

  13. Shunt insufficiency due to knot formation in the peritoneal catheter.

    PubMed

    Fekete, Gábor; Nagy, Andrea; Pataki, István; Bognar, László; Novák, László

    2013-07-30

    The authors report a rare case of the peripheral obstruction of a ventriculoperitoneal shunt. Premature baby was operated on hydrocephalus due to germinal matrix bleeding. After two months of implantation of venticuloperitoneal shunt peripheral insufficiency of the system was emerged. During the shunt revision extensive knot formation became visible. We simply cut the catheter above the knot and the working shunt was replaced into the abdominal cavity. The postoperative course was uneventful and the baby was free of complaints for more than one year. The pathomechanism of knot formation is not clear thus the discovery of the problem during the operation is an unexpected event. In our opinion tight knot cannot be spontaneously formed intraabdominally. Loose knots can be developed and can reduce the capacity of liquor flow. We think that the knot tightens during pulling out. Longer peritoneal catheters can precipitate multiple looping and/or axial torquations and increase the peripheral resistance of the shunt. In such cases when the pulling out is challenged conversion to laparotomy is suggested.

  14. Favorable results with syringosubarachnoid shunts for treatment of syringomyelia.

    PubMed

    Tator, C H; Meguro, K; Rowed, D W

    1982-04-01

    From 1969 to 1979, 20 patients with syringomyelia were treated with a syringosubarachnoid shunt. The principal indications for this procedure were: significant progressive neurological deterioration and absent or minimal tonsillar ectopia. There were 15 patients with idiopathic syringomyelia, four with posttraumatic syringomyelia, and one with syringomyelia secondary to spinal arachnoiditis. The operations were performed with an operating microscope, and attention was directed to preserving thearachnoid membrane to ensure proper placement of the distal end of the shunt in an intact subarachnoid space. In all cases, a silicone rubber ventricular catheter was inserted into the syrinx through a posterior midline myelotomy. The average follow-up period was 5 years. A favorable result was obtained in 15 of the 20 patients (75%), including an excellent result with improvement of neurological deficit in 11 patients and a good result with cessation of progression in four patients. In the remaining five patients the result was poor with further progression of neurological deficit. A short duration of preoperative symptoms was usually a favorable prognostic feature. Four patients with a history of less than 6 months all had excellent results. Thirteen patients had a syringosubarachnoid shunt only, and all had good or excellent results. Seven patients had other surgical procedures, before, accompanying, or after shunt placement, and two had favorable results. Thus, the syringosubarachnoid shunt is an effective therapeutic modality for many patients with syringomyelia, particularly if there is little or no tonsillar herniation.

  15. A simplified technique of performing splenorenal shunt (Omar's technique).

    PubMed

    Shah, Omar Javed; Robbani, Irfan

    2005-01-01

    The splenorenal shunt procedure introduced by Robert Linton in 1947 is still used today in those regions of the world where portal hypertension is a common problem. However, because most surgeons find Linton's shunt procedure technically difficult, we felt that a simpler technique was needed. We present the surgical details and results of 20 splenorenal anastomosis procedures performed within a period of 30 months. Half of the patients (Group I) underwent Linton's conventional technique of splenorenal shunt; the other half (Group II) underwent a newly devised, simplified shunt technique. This new technique involves dissection of the fusion fascia of Toldt. The outcome of the 2 techniques was identical with respect to the reduction of preshunt portal pressure. However, our simplified technique was advantageous in that it significantly reduced the duration of surgery (P <0.001) and the amount of intraoperative blood loss (P <0.003). No patient died after either operation. Although Linton's splenorenal shunt is difficult and technically demanding, it is still routinely performed. The new technique described here, in addition to being simpler, helps achieve good vascular control, permits easier dissection of the splenic vein, enables an ideal anastomosis, decreases intraoperative blood loss, and reduces the duration of surgery. Therefore, we recommend the routine use of this simplified technique (Omar's technique) for the surgical treatment of portal hypertension. PMID:16429901

  16. Analysis of optical fiber-based LP(01) ↔ LP(02) mode converters for the O-, S-, and C-Band.

    PubMed

    Mellah, Hakim; Zhang, Xiupu; Shen, Dongya

    2015-06-10

    This paper proposes a double fiber taper-based mode converter that converts LP(01) to LP(02) and vice versa. The first taper is used to convert LP(01) to some higher order LP(0m) (m>1) modes while the second taper suppresses the undesired higher order modes (m>2) and results in LP(02) overwhelmingly dominated. A simulation shows that conversion efficiency of almost 100% at the central wavelength of O-, S-, and C-Band, and above 98% over the S- and C-Band was achieved. Moreover, suppression of undesired higher order modes is more than 10 dB over the whole O-, S-, and C-Band. In particular, the suppression is more than 19 dB for the whole C-Band. The analysis also shows that the performance of the mode converter is not sensitive to slight variations of the converter's parameters. The same converter also can be used to convert LP(02) back to LP(01). It is shown that conversion efficiency higher than 99% and suppression of undesired higher order modes higher than 30 dB can be obtained. Further, a (de)multiplexer for an LP(02) and an LP(01) mode was designed using the mode converter combined with a symmetric directional coupler. The multiplexer is broadband and has an insertion loss less than 0.5 dB in the C-Band. PMID:26192862

  17. A Subglandular Breast Cerebrospinal Fluid Pseudocyst Following Postsurgical Shunt Migration

    PubMed Central

    Mlynek, Karolina; Frautschi, Russell; Halasa, Brianna; Kwiecien, Grzegorz

    2015-01-01

    Summary: Cerebrospinal fluid (CSF) drainage catheters have been associated with numerous complications in various anatomic locations, because of migration, infection, and obstruction. However, breast-related CSF shunt complications tend to occur infrequently or have seldom been reported in the empirical literature. Therefore, a case is presented detailing a breast pseudocyst caused by migration and subsequent coiling of a ventriculoperitoneal shunt in the right breast pocket. To the best of the authors’ knowledge, this is the first case that has been reported in the peer-reviewed literature of a pseudocyst resulting from a CSF drainage catheter coiling around the breast implant post pancreaticoduodenectomy. Moreover, this case highlights the importance of cross-disciplinary procedural awareness, particularly in regards to breast, ventriculoperitoneal shunt, and pancreatic procedures. PMID:26894004

  18. Temporal and spatial distributions of carbon shunting arc plasma

    NASA Astrophysics Data System (ADS)

    Takaki, Koichi; Konishi, Takumi; Mikawa, Ryota; Takahashi, Kazunori; Yukimura, Ken

    2015-01-01

    The temporal and spatial distributions of a magnetically driven shunting arc plasma were obtained using time-resolved probe measurement. A shunting arc was produced using a carbon rod and accelerated along a pair of rail electrodes by a Lorenz force. The pulse current for driving and maintaining the plasma was supplied from a 20 µF capacitor charged by a dc power supply. Double and single probes were employed to obtain the ion density of the shunting arc plasma. An ion density of 1 × 1019 m-3 was obtained at a distance of 50 mm from the carbon rod 15 µs after applying voltage. The ion density decreased to 2.0 × 1018 m-3 with increasing distance from 50 to 150 mm. The ion density changed with the energy inputted into the plasma.

  19. Executive function improvement in normal pressure hydrocephalus following shunt surgery.

    PubMed

    Gleichgerrcht, Ezequiel; Cervio, Andrés; Salvat, Jorge; Loffredo, Anselmo Rodríguez; Vita, Luciana; Roca, María; Torralva, Teresa; Manes, Facundo

    2009-01-01

    The aim of this investigation was to evaluate improvement of executive functions after shunt surgery in patients with early normal pressure hydrocephalus (NPH). Patients with NPH were assessed before and after shunt surgery with tests shown to be sensitive to damage to the prefrontal cortex (PFC). Significant differences were found between basal and follow-up performances on the Boston Naming Test, the backwards digits span, Part B of the Trail Making Test, and the number of words produced on the phonological fluency task. In conclusion, our study reveals that patients with NPH who respond positively to continuous slow lumbar cerebral spinal fluid drainage and receive a ventriculoperitoneal shunt implant, improve their performance on tasks of executive function. Due to the high demand for this form of mental processing in real-life complex scenarios, and based on the severe executive deficits present in both demented and non-demented NPH patients, we encourage the assessment of executive functions in this clinical group.

  20. Intraperitoneal cerebrospinal fluid pseudocyst. A rare complication of ventriculoperitoneal shunt.

    PubMed

    Birbilis, Th; Kontogianidis, K; Matis, G; Theodoropoulou, E; Efremidou, E; Argyropoulou, P

    2008-01-01

    The abdominal intraperitoneal cerebrospinal fluid pseudocyst is a rare but important complication in patients with ventriculoperitoneal shunts. We report a case of a 31-year-old female, in which a large abdominal pseudocyst was developed 1 year after insertion of a ventriculoperitoneal shunt for hydrocephalus. The abdominal CT scan and the ultrasonographical evaluation of the abdomen showed a well defined, cystic mass lesion with a volume of 50 cm3, in the recessus hepato-renal. The peritoneal tip of the shunt was located within the mass lesion. A distal externalization of the peritoneal catheter without excision of the pseudocyst was performed. Cerebrospinal fluid culture demonstrated a Staphylococcus epidermis infection and adequate antibiotic treatment was administrated. The previous symptoms improved 4 weeks later and a new catheter was placed intraperitoneally in a different quadrant. The postoperative course was uneventful. We suggest that chronic inflammation or subclinical peritonitis is a predisposing factor for this complication. PMID:18717287

  1. Rare sequelae following ventriculoatrial shunt: Case report and review of literature

    PubMed Central

    Gopal, Vinu Venu; Peethambaran, Anil Kumar

    2016-01-01

    Ventriculoatrial shunt (VA) is one of the oldest solutions for hydrocephalus. However over subsequent years various complication of VA shunt such as obstructions, malposition, shunt infections, cardiac complications such as endocarditis, traumatic perforation, heart failure, tricuspid regurgitation, intraatrial thrombus, and pulmonary hypertension are reported. Hence, VA shunt procedure has fallen into disrepute. Still VA shunt may be a good option in selected patients with hostile peritoneum. Newer placement strategies and monitoring methods have been put forward to reduce complication following VA shunt. In this case report, we share a rare case of endocarditis with tricuspid regurgitation following a migrated retained calcified shunt tube in the right ventricle of heart 30 years after of VA shunt that was successfully managed. PMID:27057231

  2. Breast-related CSF shunt complications: literature review with illustrative case.

    PubMed

    Schrot, Rudolph J; Ramos-Boudreau, Christine; Boggan, James E

    2012-09-01

    In this article, we discuss and classify breast-related ventriculoperitoneal (VP) cerebrospinal fluid (CSF) shunt complications, and provide a literature review. Shunt complications related to pre-existing breast implants comprise nearly half of the breast-related shunt complications reported thus far. We present a complication of shunt failure in a 61-year-old woman who had previously undergone mastectomies for breast cancer with implant reconstruction. Following shunting, she developed headaches, fever, and right-sided breast swelling and erythma consequent to breast implant rupture, distal shunt migration, and CSF pseudocyst. This case is unique in that it involved rupture of a breast implant from VP shunt insertion. For complication avoidance, neurosurgeons should be aware of the potential pitfalls in shunting patients with breast implants.

  3. Time-related patterns of ventricular shunt failure.

    PubMed

    Kast, J; Duong, D; Nowzari, F; Chadduck, W M; Schiff, S J

    1994-11-01

    Proximal obstruction is reported to be the most common cause of ventriculoperitoneal (VP) shunt failure, suggesting that imperfect ventricular catheter placement and inadequate valve mechanisms are major causes. This study retrospectively examined patterns of shunt failure in 128 consecutive patients with symptoms of shunt malfunction over a 2-year period. Factors analyzed included site of failure, time from shunt placement or last revision to failure, age of patient at time of failure, infections, and primary etiology of the hydrocephalus. One hundred of these patients required revisions; 14 revisions were due to infections. In this series there was a higher incidence of distal (43%) than of proximal (35%) failure. The difference was not statistically significant when the overall series was considered; however, when factoring time to failure as a variable, marked differences were noted regardless of the underlying cause of hydrocephalus or the age of the patient. Of the 49 patients needing a shunt revision or replacement within 2 years of the previous operation, 50% had proximal malfunction, 14% distal, and 10% had malfunctions attributable directly to the valve itself. Also, 12 of the 14 infections occurred during this time interval. In sharp contrast, of the 51 patients having shunt failure from 2 to more than 12 years after the previous procedure, 72% had distal malfunction, 21% proximal, and only 6% had a faulty valve or infection. This difference between time to failure for proximal versus distal failures was statistically significant (P < 0.00001 for both Student's t-test and non-parametric Mann-Whitney U-test).(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Utility of Operative Glaucoma Tube Shunt Viscoelastic Bolus Flush

    PubMed Central

    Groth, Sylvia L; Greider, Kelsi L

    2015-01-01

    ABSTRACT Objective: To assess the utility of viscoelastic injection to induce bleb expansion and decrease intraocular pressure (IOP) in eyes with encapsulated glaucoma tube shunt blebs. Design: Case series. Subjects and participants: Forty-three glaucomatous eyes, including 13 eyes with congenital, 13 uveitic, 5 neovascular, 5 open angle, 4 narrow angle and 3 traumatic glaucomas. Methods, interventions or testing: All patients underwent viscoelastic flush procedure. A pre-bent 27 or 30-gauge cannula was passed through a 25-gauge paracentesis, advanced over the iris across the anterior chamber, and insinuated into the tube shunt lumen. Once the cannula was firmly lodged in position, 0.45 to 0.85 ml of viscoelastic was injected to hyperinflate the bleb. Main outcome measures: Paired t-tests were performed comparing preoperative IOP and number of medications used preoperatively vs levels measured at 1, 6, 12, 18 and 24 months. Results: Intraocular pressure was reduced from a mean preoperative level of 26.0 ± 1.2 (sem) mm Hg to 15.8 ± 1.0 at 1 month, remaining stable thereafter at each 6-month interval with 15.1 ± 1.1 mm Hg at 24 months (p < 0.0001). Medication use did not vary significantly from baseline. Pressure remained < 21 mm Hg after 2 years in 85% of eyes cannulated within 1 year of primary tube shunt implantation (n = 23), and in 62% of eyes cannulated more than 1 year after tube shunt placement (n = 20). Conclusion: Tube shunt expansion with bolus viscoelastic flush successfully restored encapsulated bleb function, providing a substantial (~10 mm Hg) IOP decrease into the mid-normal pressure range. This persisted in the majority of treated eyes for the entire study period. How to cite this article: Groth SL, Greider KL, Sponsel WE. Utility of Operative Glaucoma Tube Shunt Viscoelastic Bolus Flush. J Curr Glaucoma Pract 2015;9(3):73-76. PMID:26997840

  5. In Vitro and In Vivo Comparison of Two Suprachoroidal Shunts

    PubMed Central

    Oatts, Julius T.; Zhang, Ze; Tseng, Harry; Shields, M. Bruce; Sinard, John H.; Loewen, Nils A.

    2013-01-01

    Purpose. To compare fibrosis, aqueous humor dynamics, and intraocular pressure (IOP) of two suprachoroidal shunts as part of a new class of glaucoma drainage devices. Methods. Following proliferation analysis in vitro, 20 rabbits were implanted with either a gold shunt (GS, GMSplus+, SOLX) or a polypropylene shunt (PS, Aquashunt, OPKO). Ten eyes received mitomycin C (MMC) and triamcinolone. Peak and trough IOP were monitored with a pneumatonometer and tono-pen for 15 weeks. Aqueous humor dynamics were evaluated fluorophotometrically and tonographically. Fibrosis was quantified. Results. In vitro proliferation was similar. In vivo, both shunts were devoid of foreign body reaction but exhibited fibrosis, and GS showed vascularization. There was no significant difference in aqueous or uveoscleral flow. Preoperative morning IOP was 23.7 ± 2 mm Hg, and evening IOP was 26.5 ± 2 mm Hg (P = 0.000). Morning IOP was decreased through 15 weeks and evening IOP through 8 weeks in all groups. The morning IOP decrease was most profound at 15 weeks in PS (41%) compared to GS (18%). Antifibrotics initially enhanced but eventually diminished shunt performance. At 15 weeks, thickness of scleral fibrosis was greater in GS (246 ± 47 μm) and PS (188 ± 47 μm, P = 0.285) compared with GS+MMC (109 ± 26 μm, P = 0.023 to GS) and PS+MMC (48 ± 30 μm, P = 0.028 to PS). Conclusions. In a rabbit model, suprachoroidal polypropylene and gold shunts allow access to a new drainage pathway with different IOP profiles that can be modified with antifibrotics. PMID:23847318

  6. Shunted Piezoelectric Vibration Damping Analysis Including Centrifugal Loading Effects

    NASA Technical Reports Server (NTRS)

    Min, James B.; Duffy, Kirsten P.; Provenza, Andrew J.

    2011-01-01

    Excessive vibration of turbomachinery blades causes high cycle fatigue problems which require damping treatments to mitigate vibration levels. One method is the use of piezoelectric materials as passive or active dampers. Based on the technical challenges and requirements learned from previous turbomachinery rotor blades research, an effort has been made to investigate the effectiveness of a shunted piezoelectric for the turbomachinery rotor blades vibration control, specifically for a condition with centrifugal rotation. While ample research has been performed on the use of a piezoelectric material with electric circuits to attempt to control the structural vibration damping, very little study has been done regarding rotational effects. The present study attempts to fill this void. Specifically, the objectives of this study are: (a) to create and analyze finite element models for harmonic forced response vibration analysis coupled with shunted piezoelectric circuits for engine blade operational conditions, (b) to validate the experimental test approaches with numerical results and vice versa, and (c) to establish a numerical modeling capability for vibration control using shunted piezoelectric circuits under rotation. Study has focused on a resonant damping control using shunted piezoelectric patches on plate specimens. Tests and analyses were performed for both non-spinning and spinning conditions. The finite element (FE) shunted piezoelectric circuit damping simulations were performed using the ANSYS Multiphysics code for the resistive and inductive circuit piezoelectric simulations of both conditions. The FE results showed a good correlation with experimental test results. Tests and analyses of shunted piezoelectric damping control, demonstrating with plate specimens, show a great potential to reduce blade vibrations under centrifugal loading.

  7. Fetal ovarian cyst mimicking a CSF pseudocyst in the setting of shunt failure.

    PubMed

    Calayag, Mark; Malone, Christian Cantillano; Drake, Brian; Chavhan, Govind; Rutka, James T

    2015-01-01

    Fetal ovarian cysts are common congenital lesions encountered in the neonatal population. These cysts are typically benign and rarely require any invasive intervention. Abdominal pseudocyst formation as a result of a ventriculoperitoneal shunt is a relatively infrequent occurrence and is similarly an uncommon cause of shunt failure. The authors present the case of a 4-month-old girl with shunted hydrocephalus who presented with shunt failure from a suspected abdominal pseudocyst that was found to be a fetal ovarian cyst.

  8. Ventriculoperitoneal shunt complications in hydrocephalus patients with intracranial tumors: an analysis of relevant risk factors.

    PubMed

    Reddy, G Kesava; Bollam, Papireddy; Caldito, Gloria; Willis, Brian; Guthikonda, Bharat; Nanda, Anil

    2011-06-01

    Patients with intracranial tumors are predisposed to persistent hydrocephalus, often requiring a permanent CSF diversion procedure with shunts. This study reviews the long-term experience with ventriculoperitoneal shunts for the management of hydrocephalus in patients with intracranial tumors. Patients with intracranial tumors who underwent ventriculoperitoneal shunt placement for hydrocephalus from October 1990 to October 2009 were included in this study. During the 19-year period, medical charts, operative reports, imaging studies, and clinical follow- up evaluations were reviewed and analyzed retrospectively for all patients. A total of 187 intracranial tumor patients with hydrocephalus were included. The median follow up was 391 days. Malignant tumors were present in 40% of the patients. Overall shunt failure was 27.8%. Single shunt revision occurred in 13% of the patients and 14% had multiple shunt revision. Tumor histology, age and a procedure prior to shunt placement (ventriculostomy/Ommaya reservoirs) were significantly associated with the shunt revisions. Shunt system replacement and proximal shunt complication were significantly attributed to multiple shunt revisions. The overall shunt revision within 3 months, 6 months, 1 year and 5 years was 17.7%, 18.7%, 19.8% and 24.1%, respectively. The results of the study demonstrate that VP shunting is an effective for the management of hydrocephalus in patients with intracranial tumors. The overall incidence of shunt revision was 27.8%. Age, tumor histology, and a procedure prior to shunt placement (ventriculostomy/Ommaya reservoirs) were significantly associated with the shunt revisions. Additional studies using minimally invasive techniques are being explored for the management of hydrocephalus in patients with intracranial tumors.

  9. Treatment of Portosystemic Shunt Myelopathy with a Stent Graft Deployed through a Transjugular Intrahepatic Route

    SciTech Connect

    Jain, Deepak Arora, Ankur; Deka, Pranjal; Mukund, Amar Bhatnagar, Shorav; Jindal, Deepti Kumar, Niteen Pamecha, Viniyendra

    2013-08-01

    A case of surgically created splenorenal shunt complicated with shunt myelopathy was successfully managed by placement of a stent graft within the splenic vein to close the portosystemic shunt and alleviate myelopathy. To our knowledge, this is the first report of a case of shunt myelopathy in a patient with noncirrhotic portal fibrosis without cirrhosis treated by a novel technique wherein a transjugular intrahepatic route was adopted to deploy the stent graft.

  10. EBNA2 and Its Coactivator EBNA-LP.

    PubMed

    Kempkes, Bettina; Ling, Paul D

    2015-01-01

    While all herpesviruses can switch between lytic and latent life cycle, which are both driven by specific transcription programs, a unique feature of latent EBV infection is the expression of several distinct and well-defined viral latent transcription programs called latency I, II, and III. Growth transformation of B-cells by EBV in vitro is based on the concerted action of Epstein-Barr virus nuclear antigens (EBNAs) and latent membrane proteins(LMPs). EBV growth-transformed B-cells express a viral transcriptional program, termed latency III, which is characterized by the coexpression of EBNA2 and EBNA-LP with EBNA1, EBNA3A, -3B, and -3C as well as LMP1, LMP2A, and LMP2B. The focus of this review will be to discuss the current understanding of how two of these proteins, EBNA2 and EBNA-LP, contribute to EBV-mediated B-cell growth transformation. PMID:26428371

  11. Endophthalmitis associated with Glaucoma Shunt Intraluminal Stent Exposure.

    PubMed

    Kwon, Hye Jin; Kerr, Nathan M; Ruddle, Jonathan B; Ang, Ghee Soon

    2016-01-01

    Endophthalmitis post glaucoma drainage implant (GDI) surgery is rare, often associated with tube or plate exposure. We report a case of endophthalmitis following glaucoma shunt intraluminal stent exposure in a patient who underwent Baerveldt glaucoma implant surgery. Endophthalmitis following manipulation of intraluminal stents is a rare complication of GDIs but potentially vision threatening condition that needs to be carefully screened for and treated immediately. How to cite this article: Kwon HJ, Kerr NM, Ruddle JB, Ang GS. Endophthalmitis associated with Glaucoma Shunt Intraluminal Stent Exposure. J Curr Glaucoma Pract 2016;10(1):36-37.

  12. CSF shunts 50 years on--past, present and future.

    PubMed

    Drake, J M; Kestle, J R; Tuli, S

    2000-11-01

    Cerebrospinal fluid (CSF) shunts were invented almost 50 years ago. While their introduction revolutionized the treatment of hydrocephalus, their complications have become legendary, and the focus of much investigation and development of new devices. New devices have been based upon improved understanding of the pathophysiology of hydrocephalus or shunt complications. Despite the rational, or frequently "more physiological," functioning of these devices, all too often unexpected complications have ensued, and the initial enthusiasm for the devices has waned. Assessing the efficacy of the devices has been difficult, owing to the lack of properly conducted studies. Nevertheless, the overall impact of shunt design improvements has seemed very limited. A recent randomized trial of CSF shunt design, examining the failure rates of two new and widely used valves (the Cordis Orbis Sigma and the Medtronic PS Medical Delta valves) failed to find any advantage of these over standard valve designs, many of which have been used almost since the inception of CSF shunts. A search for risk factors for failure, in a post hoc analysis of the data, indicated only that the etiology of the hydrocephalus and the position and local environment of the ventricular catheter tip were probably important. Remarkably, the rate of change in the size of the ventricles and the final ventricular size were not different despite the substantial differences in flow characteristics of the two new valves. Shunt failure rates of less than 5% at 1 year, with infection rates of less than 1%, seem like reasonable goals for the next decade in the new millenium. This can be achieved through basic research into the pathophysiology of shunt failure with improved mathematical models, and perhaps animal models of shunt failure. Efficacy of new devices or treatments must be scrutinized scientifically so as not to waste valuable resources and time on unproven treatments. Uncontrolled series and testimonial

  13. LP-gas marketers nationwide reveal hardships encountered during crisis

    SciTech Connect

    Not Available

    1990-04-01

    The authors report on a survey of 150 randomly-selected LP-gas marketers nationwide. Replies were solicited from every major geographical region. The purpose of the survey was to obtain a comprehensive sampling of information on local price increases, shipping difficulties, relations with customers, and strategies for the future. This paper presents a profile that sums up the effects of the propane emergency on marketers and customers.

  14. Smell of danger: an analysis of LP-gas odorization

    SciTech Connect

    Cain, W.S.; Turk, A.

    1985-03-01

    LP-gas derives warning properties from the odorants ethyl mercaptan or thiophane. Laboratory tests have implied that the average person has the ability to smell the odors before leaking LP-gas reaches one-fifth its lower limit of flammability. Generally, however, laboratory tests ignore or discard persons with a poor sense of smell, especially the elderly and persons with certain types of hyposmia. Some persons who apparently can smell the warning agents when directed may otherwise fail to notice or identify them. Elderly men seem particularly vulnerable to instances of incidental anosmia and olfactory agnosia. Psychophysical testing of the warning agents has been rather unsophisticated. There exists neither a standard protocol for testing nor adequate specification of the perceptual properties that might make one warning agent better than another. Without such developments, improvement in warning agents will fail to occur. Possible improvements include increases in concentration, the use of blends to insure more uniform delivery of agent and, to decrease the perceptual vulnerability of relatively insensitive people, use of agents with favorable psychophysical (stimulus-response) functions and use of agents with favorable adaptation characteristics. Even without a change in existing products, it seems advisable to learn more about the vulnerability of LP-gas users and to employ educational means to reduce risks.

  15. A Retrospective Analysis of Ventriculoperitoneal Shunt Revision Cases of a Single Institute

    PubMed Central

    Park, Man-Kyu; Kim, Myungsoo; Park, Ki-Su; Park, Seong-Hyun; Hwang, Jeong-Hyun

    2015-01-01

    Objective Ventriculoperitoneal (VP) shunt complication is a major obstacle in the management of hydrocephalus. To study the differences of VP shunt complications between children and adults, we analyzed shunt revision surgery performed at our hospital during the past 10 years. Methods Patients who had undergone shunt revision surgery from January 2001 to December 2010 were evaluated retrospectively by chart review about age distribution, etiology of hydrocephalus, and causes of revision. Patients were grouped into below and above 20 years old. Results Among 528 cases of VP shunt surgery performed in our hospital over 10 years, 146 (27.7%) were revision surgery. Infection and obstruction were the most common causes of revision. Fifty-one patients were operated on within 1 month after original VP shunt surgery. Thirty-six of 46 infection cases were operated before 6 months after the initial VP shunt. Incidence of shunt catheter fracture was higher in younger patients compared to older. Two of 8 fractured catheters in the younger group were due to calcification and degradation of shunt catheters with fibrous adhesion to surrounding tissue. Conclusion The complications of VP shunts were different between children and adults. The incidence of shunt catheter fracture was higher in younger patients. Degradation of shunt catheter associated with surrounding tissue calcification could be one of the reasons of the difference in facture rates. PMID:26113963

  16. Successful Embolization of a Spontaneous Mesocaval Shunt Using the Amplatzer Vascular Plug II

    SciTech Connect

    Boixadera, Helena; Tomasello, Alejandro; Quiroga, Sergi; Cordoba, Joan; Perez, Mercedes; Segarra, Antoni

    2010-10-15

    A 48-year-old man with alcoholic liver cirrhosis and hepatic encephalopathy was found to have a large, spontaneous mesocaval shunt. The shunt was successfully occluded with the use of an Amplatzer Vascular Plug. To our knowledge, this is the first report of the use of this device to embolize a mesocaval shunt involving the superior mesenteric vein.

  17. High-Flow Arterio-Hepatic Venous Shunt in Hepatocellular Carcinoma: Use of Multi-Electrode Radiofrequency for Shunt Obliteration

    SciTech Connect

    Pua, Uei

    2015-10-15

    Intra-tumoral arterio-hepatic venous shunting (AHVS) poses an impediment to transarterial chemoembolization of liver tumors. Not only does it present a potential hazard for systemic shunting and embolization, but also the altered flow dynamics may also result in poor delivery of drug/embolics to the target tumor bed. Current available techniques to overcome AVHS include arterial embolization (particles, coils, glue, etc.) or temporary venous occlusion using balloons. We hereby illustrate the use of radiofrequency ablation to obliterate a complex AHVS consisting of a varix-like venous aneurysm.

  18. 78 FR 32294 - DeltaPoint Capital IV, L.P., DeltaPoint Capital IV (New York), L.P., License No. 02/02-0662,02/02...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... ADMINISTRATION DeltaPoint Capital IV, L.P., DeltaPoint Capital IV (New York), L.P., License No. 02/02-0662,02/02... Interest Notice is hereby given that DeltaPoint Capital IV, L.P. and DeltaPoint Capital IV (New York), L.P...). DeltaPoint Capital IV, L.P. provided financing to Switchgear Acquisition, Inc., 1211Stewart...

  19. The Lp_3561 and Lp_3562 Enzymes Support a Functional Divergence Process in the Lipase/Esterase Toolkit from Lactobacillus plantarum

    PubMed Central

    Esteban-Torres, María; Reverón, Inés; Santamaría, Laura; Mancheño, José M.; de las Rivas, Blanca; Muñoz, Rosario

    2016-01-01

    Lactobacillus plantarum species is a good source of esterases since both lipolytic and esterase activities have been described for strains of this species. No fundamental biochemical difference exists among esterases and lipases since both share a common catalytic mechanism. L. plantarum WCFS1 possesses a protein, Lp_3561, which is 44% identical to a previously described lipase, Lp_3562. In contrast to Lp_3562, Lp_3561 was unable to degrade esters possessing a chain length higher than C4 and the triglyceride tributyrin. As in other L. plantarum esterases, the electrostatic potential surface around the active site in Lp_3561 is predicted to be basic, whereas it is essentially neutral in the Lp_3562 lipase. The fact that the genes encoding both proteins were located contiguously in the L. plantarum WCFS1 genome, suggests that they originated by tandem duplication, and therefore are paralogs as new functions have arisen during evolution. The presence of the contiguous lp_3561 and lp_3562 genes was studied among L. plantarum strains. They are located in a 8,903 bp DNA fragment that encodes proteins involved in the catabolism of sialic acid and are predicted to increase bacterial adaptability under certain growth conditions. PMID:27486450

  20. The Lp_3561 and Lp_3562 Enzymes Support a Functional Divergence Process in the Lipase/Esterase Toolkit from Lactobacillus plantarum.

    PubMed

    Esteban-Torres, María; Reverón, Inés; Santamaría, Laura; Mancheño, José M; de Las Rivas, Blanca; Muñoz, Rosario

    2016-01-01

    Lactobacillus plantarum species is a good source of esterases since both lipolytic and esterase activities have been described for strains of this species. No fundamental biochemical difference exists among esterases and lipases since both share a common catalytic mechanism. L. plantarum WCFS1 possesses a protein, Lp_3561, which is 44% identical to a previously described lipase, Lp_3562. In contrast to Lp_3562, Lp_3561 was unable to degrade esters possessing a chain length higher than C4 and the triglyceride tributyrin. As in other L. plantarum esterases, the electrostatic potential surface around the active site in Lp_3561 is predicted to be basic, whereas it is essentially neutral in the Lp_3562 lipase. The fact that the genes encoding both proteins were located contiguously in the L. plantarum WCFS1 genome, suggests that they originated by tandem duplication, and therefore are paralogs as new functions have arisen during evolution. The presence of the contiguous lp_3561 and lp_3562 genes was studied among L. plantarum strains. They are located in a 8,903 bp DNA fragment that encodes proteins involved in the catabolism of sialic acid and are predicted to increase bacterial adaptability under certain growth conditions.

  1. The Lp_3561 and Lp_3562 Enzymes Support a Functional Divergence Process in the Lipase/Esterase Toolkit from Lactobacillus plantarum.

    PubMed

    Esteban-Torres, María; Reverón, Inés; Santamaría, Laura; Mancheño, José M; de Las Rivas, Blanca; Muñoz, Rosario

    2016-01-01

    Lactobacillus plantarum species is a good source of esterases since both lipolytic and esterase activities have been described for strains of this species. No fundamental biochemical difference exists among esterases and lipases since both share a common catalytic mechanism. L. plantarum WCFS1 possesses a protein, Lp_3561, which is 44% identical to a previously described lipase, Lp_3562. In contrast to Lp_3562, Lp_3561 was unable to degrade esters possessing a chain length higher than C4 and the triglyceride tributyrin. As in other L. plantarum esterases, the electrostatic potential surface around the active site in Lp_3561 is predicted to be basic, whereas it is essentially neutral in the Lp_3562 lipase. The fact that the genes encoding both proteins were located contiguously in the L. plantarum WCFS1 genome, suggests that they originated by tandem duplication, and therefore are paralogs as new functions have arisen during evolution. The presence of the contiguous lp_3561 and lp_3562 genes was studied among L. plantarum strains. They are located in a 8,903 bp DNA fragment that encodes proteins involved in the catabolism of sialic acid and are predicted to increase bacterial adaptability under certain growth conditions. PMID:27486450

  2. 75 FR 20870 - Montreux Equity Partners II SBIC, L.P.; Montreux Equity Partners III SBIC, L.P.; Notice Seeking...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-21

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Montreux Equity Partners II SBIC, L.P.; Montreux Equity Partners III SBIC, L.P.; Notice Seeking Exemption Under Section 312 of the Small Business Investment Act, Conflicts of Interest Notice is hereby given that Montreux Equity Partners II...

  3. Risk factors for shunt malfunction in pediatric hydrocephalus: a multicenter prospective cohort study.

    PubMed

    Riva-Cambrin, Jay; Kestle, John R W; Holubkov, Richard; Butler, Jerry; Kulkarni, Abhaya V; Drake, James; Whitehead, William E; Wellons, John C; Shannon, Chevis N; Tamber, Mandeep S; Limbrick, David D; Rozzelle, Curtis; Browd, Samuel R; Simon, Tamara D

    2016-04-01

    OBJECT The rate of CSF shunt failure remains unacceptably high. The Hydrocephalus Clinical Research Network (HCRN) conducted a comprehensive prospective observational study of hydrocephalus management, the aim of which was to isolate specific risk factors for shunt failure. METHODS The study followed all first-time shunt insertions in children younger than 19 years at 6 HCRN centers. The HCRN Investigator Committee selected, a priori, 21 variables to be examined, including clinical, radiographic, and shunt design variables. Shunt failure was defined as shunt revision, subsequent endoscopic third ventriculostomy, or shunt infection. Important a priori-defined risk factors as well as those significant in univariate analyses were then tested for independence using multivariate Cox proportional hazard modeling. RESULTS A total of 1036 children underwent initial CSF shunt placement between April 2008 and December 2011. Of these, 344 patients experienced shunt failure, including 265 malfunctions and 79 infections. The mean and median length of follow-up for the entire cohort was 400 days and 264 days, respectively. The Cox model found that age younger than 6 months at first shunt placement (HR 1.6 [95% CI 1.1-2.1]), a cardiac comorbidity (HR 1.4 [95% CI 1.0-2.1]), and endoscopic placement (HR 1.9 [95% CI 1.2-2.9]) were independently associated with reduced shunt survival. The following had no independent associations with shunt survival: etiology, payer, center, valve design, valve programmability, the use of ultrasound or stereotactic guidance, and surgeon experience and volume. CONCLUSIONS This is the largest prospective study reported on children with CSF shunts for hydrocephalus. It confirms that a young age and the use of the endoscope are risk factors for first shunt failure and that valve type has no impact. A new risk factor-an existing cardiac comorbidity-was also associated with shunt failure.

  4. Complications and subsequent removal of retained shunt hardware after endoscopic third ventriculostomy: case series.

    PubMed

    Pindrik, Jonathan; Jallo, George I; Ahn, Edward S

    2013-06-01

    This case series highlights multiple complications and subsequent removal of retained shunt hardware in pediatric patients after successful endoscopic third ventriculostomy (ETV). Removal or retention of existing shunt hardware following ETV represents an important dilemma. Prior studies have reported infections and organ perforation related to nonfunctioning shunts but none in the context of successful ETV. Data obtained in 3 children with hydrocephalus treated at the authors' institution were retrospectively reviewed after the patients experienced complications due to retained shunt hardware following ETV. Etiologies of hydrocephalus included tectal glioma and intraventricular hemorrhage. All 3 patients had a history of multiple shunt revisions and underwent urgent ETV in the setting of a shunt malfunction. In each case, the entire shunt system was left in situ, but it became the source of subsequent complications. Two of the 3 patients presented with the shunt infected by gram-negative bacilli 10 days and 4.5 months postoperatively, respectively. The remaining patient experienced wound dehiscence over the shunt valve 4.5 months after ETV. In all patients, the complications were managed successfully by removing the shunt hardware. None of the patients required repeat shunt insertion from the time of removal throughout the follow-up period (mean 24 months, range 9-36 months). During the study period, a total of 6 patients with indwelling shunt hardware underwent ETV with the expectation of being shunt independent. Among these 6 patients, 3 experienced no complications from the retained hardware whereas 3 patients (50%) ultimately experienced adverse consequences related to retained hardware. This case series illustrates complications involving retained shunt hardware after successful ETV. These examples support consideration of shunt removal at the time of ETV in the appropriate context.

  5. Comparison of passive inductor designs for piezoelectric shunt damping

    NASA Astrophysics Data System (ADS)

    Lossouarn, Boris; Thierry, Olivier; Aucejo, Mathieu; Deü, Jean-François

    2016-04-01

    Considering piezoelectric damping, a resonant shunt can lead to a significant vibration reduction when tuned to the mechanical mode to control. However, limits appear when looking at practical applications in a low frequency range: the required inductance is often too high to be satisfied with standard passive components. Moreover, even if the inductor is eventually available, the internal resistance of the component generally exceeds the value which is required for a shunt optimization. Suitable inductors can be designed for applications requiring high inductance and low resistance values. Indeed, the permeance of a magnetic circuit can be significantly increased by the use of closed cores made of high permeability materials. In this paper, three designs are described and compared: an inductor from standard series and two handmade inductors involving a ferrite core and a nanocrystalline toroid. The components are successively integrated into a piezoelectric shunt dedicated to the vibration control of a cantilever beam. Depending on the frequency of the target mechanical mode to control, the benefits and the limits of the different inductors are observed. It is shown that custom designs can definitely extend to lower frequency the application of the passive resonant shunt strategy.

  6. CONTEXT VIEW ALONG EXISTING PERIMETER TRACKS LOOKING TOWARDS SHUNTS IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONTEXT VIEW ALONG EXISTING PERIMETER TRACKS LOOKING TOWARDS SHUNTS IN THEIR PRESENT-DAY POSITIONS, STORAGE SHED, AND MACHINE SHOP. LOOKING NORTHEAST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  7. The Evolution of Transjugular Intrahepatic Portosystemic Shunt: Tips

    PubMed Central

    Fanelli, Fabrizio

    2014-01-01

    Since Richter's description in the literature in 1989 of the first procedure on human patients, transjugular intrahepatic portosystemic shunt (TIPS) has been worldwide considered as a noninvasive technique to manage portal hypertension complications. TIPS succeeds in lowering the hepatic sinusoidal pressure and in increasing the circulatory flow, thus reducing sodium retention, ascites recurrence, and variceal bleeding. Required several revisions of the shunt TIPS can be performed in case of different conditions such as hepatorenal syndrome, hepatichydrothorax, portal vein thrombosis, and Budd-Chiari syndrome. Most of the previous studies on TIPS procedure were based on the use of bare stents and most patients chose TIPS 2-3 years after traditional treatment, thus making TIPS appear to be not superior to endoscopy in survival rates. Bare stents were associated with higher incidence of shunt failure and consequently patients required several revisions during the follow-up. With the introduction of a dedicated e-PTFE covered stent-graft, these problems were completely solved, No more reinterventions are required with a tremendous improvement of patient's quality of life. One of the main drawbacks of the use of e-PTFE covered stent-graft is higher incidence of hepatic encephalopathy. In those cases refractory to the conventional medical therapy, a shunt reduction must be performed. PMID:27335841

  8. Shunt impedance measurement of the APS BBC injector.

    SciTech Connect

    Sun, Y.-E.; Lewellen, J. W.

    2006-01-01

    The injector test stand (ITS) at Advanced Photon Source (APS) presently incorporates a ballistic bunch compression (BBC) gun, and it is used as a beam source for a number of experiments, including THz generation, beam position monitor testing for the Linac Coherent Light Source (LCLS), novel cathode testing, and radiation therapy source development. The BBC gun uses three independently powered and phased rf cavities, one cathode cell, and two full cells to provide beam energies from 2 to 10 MeV with variable energy spread, energy chirp, and, to an extent, bunch duration. The shunt impedance of an rf accelerator determines how effectively the accelerator can convert supplied rf power to accelerating gradient. The calculation of the shunt impedance can be complicated if the beam energy changes substantially during its transit through a cavity, such as in a cathode cell. We present the results of direct measurements of the shunt impedance of the APS BBC gun on an individual cavity basis, including the cathode cell, and report on achieved gradients. We also present a comparison of the measured shunt impedance with theoretical values calculated from the rf models of the cavities.

  9. Ascites-induced LeVeen shunt coagulopathy.

    PubMed Central

    Ragni, M V; Lewis, J H; Spero, J A

    1983-01-01

    Ten of 11 patients undergoing peritoneovenous (LeVeen) shunt placement for intractable ascites had disseminated intravascular coagulation (DIC) following the shunt procedure. Intraoperative ascitic fluid specimens revealed fibrin split products (FSP) in high titer (1:100-1:1600) in all patients. Endotoxin was found in 6 of 11 ascitic fluid samples but in no plasma samples. Activated clotting factors, clot inhibitors, excess protein, and fibrinolytic activity were not found in ascitic fluid. Clotting factor levels were much lower than in plasma. Bleeding occurred after operation in two patients; this appeared to be related to the severity of liver dysfunction as demonstrated by elevations of bilirubin, serum glutamic oxalocetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), and preoperative DIC. It is concluded that the LeVeen shunt coagulopathy is DIC, and may be related to exposure of the systemic circulation to FSP-rich ascitic fluid that may activate the coagulation mechanism. Bleeding complications do not appear to be related to the severity of the post shunt coagulopathy, but rather to the severity of liver dysfunction and presence of preoperative DIC (probably caused by the liver disease). PMID:6859998

  10. Increased concentrations of serum Lp(a) lipoprotein in patients with primary gout.

    PubMed Central

    Takahashi, S; Yamamoto, T; Moriwaki, Y; Tsutsumi, Z; Higashino, K

    1995-01-01

    OBJECTIVES--To investigate if serum Lp(a) lipoprotein (Lp(a)), a risk factor for atherosclerotic diseases, increases in patients with gout, who frequently also have atherosclerotic disease. METHODS--Fasting blood samples were taken for measurement of Lp(a) and other variables in 175 male patients with primary gout. Serum concentrations of Lp(a) were measured by enzyme linked immunosorbent assay. The median value and frequency distribution of Lp(a) in gout patients were compared with those in 172 control male subjects. In addition, we examined the effect of niceritorol on serum Lp(a) values in gout patients in whom the Lp(a) concentration was greater than 20 mg/dl. RESULTS--Serum Lp(a) was significantly higher in patients with gout than control subjects (median 15.5 mg/dl upsilon 8.6 mg/dl; p < 0.01). The frequency distribution of Lp(a) in gout was significantly shifted towards greater concentrations compared with control, although skewed distribution was noted in both groups. Serum Lp(a) concentration was not related to age, body mass index, alcohol intake, creatinine, fasting blood sugar or uric acid in patients with gout. Niceritorol decreased the serum concentrations of Lp(a) in gout. CONCLUSIONS--These observations suggest that serum Lp(a) concentrations are increased in patients with gout and may play a role as one of the risk factors for atherosclerotic diseases in gout. Niceritorol seems effective in decreasing high levels of Lp(a) in patients with gout without detrimental influence on serum uric acid concentration. PMID:7702412

  11. Constipation as a reversible cause of ventriculoperitoneal shunt failure. Report of two cases.

    PubMed

    Powers, Ciaran J; George, Timothy; Fuchs, Herbert E

    2006-09-01

    Ventriculoperitoneal (VP) shunt failure is a common problem encountered by pediatric neurosurgeons. The majority of such failures are due to obstruction of the device. Conditions in which intraabdominal pressure is chronically elevated, such as pregnancy, have been associated with shunt failure. Chronic constipation may also result in abnormally elevated intraabdominal pressure and may be an underrecognized cause of distal VP shunt failure. The authors describe the cases of two children who presented with clinical and imaging evidence of VP shunt failure and who were also severely constipated. Treatment of their constipation resulted in both clinical and imaging-documented resolution of their shunt failure.

  12. Inferior vena cava stent grafting closure of a high-flow portacaval shunt.

    PubMed

    Alhaizaey, Abdullah; Ghanekar, Anand; Oreopoulos, George

    2016-01-01

    Portacaval (PC) shunts can be of congenital or acquired types. Acquired PC shunts are usually created in patients with end-stage liver disease to manage complications associated with portal hypertension or may be part of selected adult-adult living donor liver transplantation procedures to decrease the chance of the small-for-size syndrome. The main potential complication of these acquired high-flow PC shunts is early hepatic encephalopathy. We present a case of a high-flow acquired PC shunt after liver transplantation that was complicated by uncontrolled encephalopathy. This was treated by endovascular inferior vena cava stent grafting for shunt closure. PMID:26946901

  13. Pulmonary Arterial Hypertension Associated with Congenital Portosystemic Shunts Treated with Transcatheter Embolization and Pulmonary Vasodilators.

    PubMed

    Sato, Haruka; Miura, Masanobu; Yaoita, Nobuhiro; Yamamoto, Saori; Tatebe, Shunsuke; Aoki, Tatsuo; Satoh, Kimio; Ota, Hideki; Takase, Kei; Sugimura, Koichiro; Shimokawa, Hiroaki

    2016-01-01

    Cardiopulmonary abnormalities are often present in patients with liver diseases. We herein report a case of congenital portosystemic shunts complicated by hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PoPH). A 57-year-old woman complained of dyspnea and was subsequently diagnosed with HPS and PoPH caused by congenital portosystemic shunts. Although shunt closure by transcatheter embolization was successfully performed, her dyspnea worsened and pulmonary artery pressure and pulmonary vascular resistance elevated. Conventional vasodilator therapy was started, resulting in an improvement of pulmonary hypertension (PH). In some patients with congenital portosystemic shunts, shunt closure could exacerbate PH, and vasodilator therapy may be effective. PMID:27580545

  14. Control of an electromechanical hydrocephalus shunt--a new approach.

    PubMed

    Elixmann, Inga M; Kwiecien, Monika; Goffin, Christine; Walter, Marian; Misgeld, Berno; Kiefer, Michael; Steudel, Wolf-Ingo; Radermacher, Klaus; Leonhardt, Steffen

    2014-09-01

    Hydrocephalus is characterized by an excessive accumulation of cerebrospinal fluid (CSF). Therapeutically, an artificial pressure relief valve (so-called shunt) is implanted which opens in case of increased intracranial pressure (ICP) and drains CSF into another body compartment. Today, available shunts are of a mechanical nature and drainage depends on the pressure drop across the shunt. According to the latest data, craniospinal compliance is considered to be even more important than mean ICP alone. In addition, ICP is not constant but varies due to several influences. In fact, heartbeat-related ICP waveform patterns depend on volume changes in the cranial vessels during a heartbeat and changes its shape as a function of craniospinal compliance. In this paper, we present an electromechanical shunt approach, which changes the CSF drainage as a function of the current ICP waveform. A series of 12 infusion tests in patients were analyzed and revealed a trend between the compliance and specific features of the ICP waveform. For waveform analysis of patient data, an existing signal processing algorithm was improved (using a Moore machine) and was implemented on a low-power microcontroller within the electromechanical shunt. In a test rig, the ICP waveforms were replicated and the decisions of the ICP analysis algorithm were verified. The proposed control algorithm consists of a cascaded integral controller which determines the target ICP from the measured waveform, and a faster inner-loop integral controller that keeps ICP close to the target pressure. Feedforward control using measurement data of the patient's position was implemented to compensate for changes in hydrostatic pressure during change in position. A model-based design procedure was used to lay out controller parameters in a simple model of the cerebrospinal system. Successful simulation results have been obtained with this new approach by keeping ICP within the target range for a healthy waveform.

  15. Experimental comparison of piezoelectric and magnetostrictive shunt dampers

    NASA Astrophysics Data System (ADS)

    Asnani, Vivake M.; Deng, Zhangxian; Scheidler, Justin J.; Dapino, Marcelo J.

    2016-04-01

    A novel mechanism called the vibration ring is being developed to enable energy conversion elements to be incorporated into the driveline of a helicopter or other rotating machines. Unwanted vibration is transduced into electrical energy, which provides a damping effect on the driveline. The generated electrical energy may also be used to power other devices (e.g., health monitoring sensors). PZT (`piezoceramic') and PMN-30%PT (`single crystal') stacks, as well as a Tb0.3Dy0.7Fe1.92 (`Terfenol-D') rod with a bias magnet array and a pickup coil, were tested as alternative energy conversion elements to use within the vibration ring. They were tuned for broadband damping using shunt resistors, and dynamic compression testing was conducted in a high-speed load frame. Energy conversion was experimentally optimized at 750Hz by tuning the applied bias stress and resistance values. Dynamic testing was conducted up to 1000Hz to determine the effective compressive modulus, shunt loss factor, internal loss factor, and total loss factor. Some of the trends of modulus and internal loss factor versus frequency were unexplained. The single crystal device exhibited the greatest shunt loss factor whereas the Terfenol-D device had the highest internal and total loss factors. Simulations revealed that internal losses in the Terfenol-D device were elevated by eddy current effects, and an improved magnetic circuit could enhance its shunt damping capabilities. Alternatively, the Terfenol-D device may be simplified to utilize only the eddy current dissipation mechanism (no pickup coil or shunt) to create broadband damping.

  16. Cerebrospinal fluid shunt infections. A review of 35 infections in 32 patients.

    PubMed

    Forward, K R; Fewer, H D; Stiver, H G

    1983-09-01

    The authors have reviewed the clinical manifestations and therapy of hydrocephalus shunt infections in 32 patients with a total of 35 shunt infections. These 35 infections accounted for 43 hospital admissions. First infections usually developed within 2 months following surgery. At the time of diagnosis, 89% of patients were febrile. Fever and cough as a symptom complex characterized the initial clinical presentation in six of 19 episodes of infection complicating ventriculoatrial (VA) shunts, as compared with none of 21 episodes in which infection complicated ventriculoperitoneal (VP) shunts. Seven of 21 infectious episodes occurring in patients with VP shunts in situ were associated with significant abdominal pain and tenderness. These patients usually had no other clinical features to suggest shunt infection. Both of these symptom complexes often led to delays in diagnosis and treatment. Causative organisms included Staphylococcus epidermidis in 21, Staphylococcus aureus in seven, Gram-negative aerobic bacilli in seven, diphtheroids in five, Streptococcus species in four, and anaerobes in three. Five infections were polymicrobial in nature. Positive blood cultures were seen in 13 of 17 infectious episodes complicating VA shunts, as compared with only three of 13 other infections. When the shunt was completely removed, with or without replacement, all 13 patients were cured. When intravenous antibiotics were administered in conjunction with incomplete shunt removal, only eight of 15 courses resulted in cure. Intraventricular antibiotics were administered in four patients and all were cured. Therapy of shunt infections with parenteral antibiotics and incomplete shunt removal is associated with an unacceptably high failure rate.

  17. Risk factors associated with distal catheter migration following ventriculoperitoneal shunt placement.

    PubMed

    Abode-Iyamah, Kingsley O; Khanna, Ryan; Rasmussen, Zachary D; Flouty, Oliver; Dahdaleh, Nader S; Greenlee, Jeremy; Howard, Matthew A

    2016-03-01

    Ventriculoperitoneal (VP) shunt placement is used to treat hydrocephalus. Shunt migration following VP shunt placement has been reported. The risk factors related to this complication have not been previously evaluated to our knowledge. In this retrospective cohort study, we aimed to determine risk factors leading to distal catheter migration and review the literature on the current methods of management and prevention. Adult patients undergoing VP shunt placement from June 2011 to December 2013 at a single institution were identified using electronic health records. The records were reviewed for demographic and procedural information, and subsequent treatment characteristics. The parameters of patients with distal shunt migration were compared to those undergoing new VP shunt placement for the same time period. We identified 137 patients undergoing 157 new VP shunt procedures with an average age of 57.7 ± standard deviation of 18.4 years old. There were 16 distal shunt migrations. Body mass index >30 kg/m(2) and number of previous shunt procedures were found to be independent risk factors for distal catheter migration. Obesity and number of previous shunt procedures were factors for distal catheter migration. Providers and patients should be aware of these possible risk factors prior to VP shunt placement.

  18. New and improved ways to treat hydrocephalus: Pursuit of a smart shunt

    PubMed Central

    Lutz, Barry R.; Venkataraman, Pranav; Browd, Samuel R.

    2013-01-01

    The most common treatment for hydrocephalus is placement of a cerebrospinal fluid shunt to supplement or replace lost drainage capacity. Shunts are life-saving devices but are notorious for high failure rates, difficulty of diagnosing failure, and limited control options. Shunt designs have changed little since their introduction in 1950s, and the few changes introduced have had little to no impact on these long-standing problems. For decades, the community has envisioned a “smart shunt” that could provide advanced control, diagnostics, and communication based on implanted sensors, feedback control, and telemetry. The most emphasized contribution of smart shunts is the potential for advanced control algorithms, such as weaning from shunt dependency and personalized control. With sensor-based control comes the opportunity to provide data to the physician on patient condition and shunt function, perhaps even by a smart phone. An often ignored but highly valuable contribution would be designs that correct the high failure rates of existing shunts. Despite the long history and increasing development activity in the past decade, patients are yet to see a commercialized smart shunt. Most smart shunt development focuses on concepts or on isolated technical features, but successful smart shunt designs will be a balance between technical feasibility, economic viability, and acceptable regulatory risk. Here, we present the status of this effort and a framework for understanding the challenges and opportunities that will guide introduction of smart shunts into patient care. PMID:23653889

  19. Role of SEP in identifying patients requiring temporary shunt during carotid endarterectomy.

    PubMed

    Fava, E; Bortolani, E; Ducati, A; Schieppati, M

    1992-01-01

    EEGs and short-latency somatosensory evoked potentials (SEPs) to median nerve stimulation were recorded during 151 carotid endarterectomies, performed under general anaesthesia. Carotid occlusion did not affect either EEG or SEP in 120 cases (group A). In 31 cases the EEG showed "ischaemic" abnormalities (group B). A temporary shunt was inserted only in 16 B patients showing also severely depressed cortical SEPs within 2 min after carotid occlusion (group B shunt). In 15 B patients in whom SEPs were less affected, the operation was completed without shunt (group B no shunt). One intraoperative stroke occurred in group A and two in group B shunt. No neurological complications occurred in group B no shunt. Overall stroke rate was 2%. On retrospective analysis, latency and amplitude of N20 and P25 waves proved to be uninfluenced by carotid occlusion in group A, but were significantly affected in group B shunt. P25 amplitude alone was reduced in B no shunt. An arbitrary index (need-for-shunt index, NSI) was made in order to rate changes of P25 latency and amplitude. Its mean values were significantly different in the 3 groups. A threshold value is suggested above which shunt is required, as a useful adjunct to EEG, in order to balance prevention of brain ischaemia against the risks of shunt.

  20. Fuzzy Inference System Approach for Locating Series, Shunt, and Simultaneous Series-Shunt Faults in Double Circuit Transmission Lines.

    PubMed

    Swetapadma, Aleena; Yadav, Anamika

    2015-01-01

    Many schemes are reported for shunt fault location estimation, but fault location estimation of series or open conductor faults has not been dealt with so far. The existing numerical relays only detect the open conductor (series) fault and give the indication of the faulty phase(s), but they are unable to locate the series fault. The repair crew needs to patrol the complete line to find the location of series fault. In this paper fuzzy based fault detection/classification and location schemes in time domain are proposed for both series faults, shunt faults, and simultaneous series and shunt faults. The fault simulation studies and fault location algorithm have been developed using Matlab/Simulink. Synchronized phasors of voltage and current signals of both the ends of the line have been used as input to the proposed fuzzy based fault location scheme. Percentage of error in location of series fault is within 1% and shunt fault is 5% for all the tested fault cases. Validation of percentage of error in location estimation is done using Chi square test with both 1% and 5% level of significance.

  1. Fuzzy Inference System Approach for Locating Series, Shunt, and Simultaneous Series-Shunt Faults in Double Circuit Transmission Lines

    PubMed Central

    Swetapadma, Aleena; Yadav, Anamika

    2015-01-01

    Many schemes are reported for shunt fault location estimation, but fault location estimation of series or open conductor faults has not been dealt with so far. The existing numerical relays only detect the open conductor (series) fault and give the indication of the faulty phase(s), but they are unable to locate the series fault. The repair crew needs to patrol the complete line to find the location of series fault. In this paper fuzzy based fault detection/classification and location schemes in time domain are proposed for both series faults, shunt faults, and simultaneous series and shunt faults. The fault simulation studies and fault location algorithm have been developed using Matlab/Simulink. Synchronized phasors of voltage and current signals of both the ends of the line have been used as input to the proposed fuzzy based fault location scheme. Percentage of error in location of series fault is within 1% and shunt fault is 5% for all the tested fault cases. Validation of percentage of error in location estimation is done using Chi square test with both 1% and 5% level of significance. PMID:26413088

  2. Peritoneovenous Shunt Insertion for Intractable Ascites-A District General Hospital Experience

    SciTech Connect

    Hussain, Fuad F. Meer, Ziad F.; Lopez, Anthony J.

    2004-08-15

    Ascites often contributes to patient morbidity and discomfort. When refractory to medical management, it has been managed with repeated paracentesis, implantable ports for drainage, or diversion to the urinary bladder. Peritoneovenous shunt insertion has been a technique that was traditionally performed only by surgeons but is now within the realm of interventional radiologists. Its advantage is that protein-rich ascitic fluid is returned to the intravascular compartment. This retrospective study elaborates on the successes and problems encountered during shunt insertion in our first 13 patients. Two patients are well with a functioning shunt at 14 and 32 weeks. In 6 the shunt functioned until the patients' death from the underlying malignancy. Two required revision with variable success and in 2, shunt function could not be salvaged. There was one procedure-related mortality. Radiological insertion of these shunts is feasible and should be considered for selected patients. Options are available for assessment and salvaging of dysfunctional shunts.

  3. Ventriculoperitoneal Shunt Complications In Children: An Evidence-Based Approach To Emergency Department Management.

    PubMed

    Bober, Jacqueline; Rochlin, Jonathan; Marneni, Shashidhar

    2016-02-01

    Although much is known about ventriculoperitoneal shunts, there are still large gaps in the literature and no evidence-based guidelines on management. To date, there is no general consensus on workup and treatment, and there are many differing diagnostic and therapeutic strategies for management of complications. Ventriculoperitoneal shunt complications can be separated into 3 categories: mechanical failure, infection, and functional failure. Knowing the basic anatomy of ventriculoperitoneal shunts, the time of shunt placement, and the clinical manifestations suggestive of potential complications can help with the management of patients with ventriculoperitoneal shunts. This review summarizes the literature on complications of ventriculoperitoneal shunts, examines the literature regarding the workup and management of patients with ventriculoperitoneal shunts, and makes recommendations for the management of these patients in the emergency department.

  4. Systemic-pulmonary artery shunts in infants: modified Blalock-Taussig and central shunt procedures.

    PubMed

    Brooks, Andre

    2014-01-01

    Access is gained through a midline sternotomy, the thymus partially excised and the superior part of the pericardium is opened. The innominate vein is retracted and the innominate artery is mobilized up to the bifurcation. The aorta is retracted to the left, the superior vena cavae to the right and the right atrial appendage inferiorly. The adventitia around the right pulmonary artery (PA) is dissected, taking care to incise the bulky pericardial reflection between the superior vena cavae and the trachea. Heparin is administrated. An occlusive clamp is applied to the right PA to test for haemodynamic tolerance prior to proceeding with the interposition of a suitable size artificial vascular prosthesis, based on the weight of the patient, between the innominate artery, or proximal subclavian artery and the right PA. Alternatively, if a sufficient main PA is present and adequate flow from a patent ductus arteriosus an end-to-side interposition shunt may be constructed between the ascending aorta and the main PA, provided the patient is stable with the test occlusion of the main PA. The management of the patent arterial ductus depends on whether or not there is forward flow through the PA.

  5. 2-LP mode few-mode fiber amplifier employing ring-core erbium-doped fiber.

    PubMed

    Ono, Hirotaka; Hosokawa, Tsukasa; Ichii, Kentaro; Matsuo, Shoichiro; Nasu, Hitoshi; Yamada, Makoto

    2015-10-19

    A fiber amplifier supporting 2 LP modes that employs a ring-core erbium-doped fiber (RC-EDF) is investigated to reduce differential modal gain (DMG). The inner and outer radii of the ring-core of the RC-EDF are clarified for 2-LP mode operation of the amplifier, and are optimized to reduce the DMG. It is shown that using the overlap integral between the erbium-doped core area and the signal power mode distribution is a good way to optimize the inner and outer radii of the ring-core of the RC-EDF and thus minimize the DMG. A fabricated RC-EDF and a constructed 2-LP mode EDFA are described and a small DMG of around 1 dB is realized for LP01, LP11 and LP21 pumping.

  6. Aerosol Correction for Improving OMPS/LP Ozone Retrieval

    NASA Technical Reports Server (NTRS)

    Chen, Zhong; Bhartia, Pawan K.; Loughman, Robert

    2015-01-01

    The Ozone Mapping and Profiler Suite Limb Profiler (OMPS-LP) on board the Suomi National Polar-orbiting Partnership (SNPP) satellite was launched on Oct. 28, 2011. Limb profilers measures the radiance scattered from the Earth's atmospheric in limb viewing mode from 290 to 1000 nm and infer ozone profiles from tropopause to 60 km. The recently released OMPS-LP Version 2 data product contains the first publicly released ozone profiles retrievals, and these are now available for the entire OMPS mission, which extends from April, 2012. The Version 2 data product retrievals incorporate several important improvements to the algorithm. One of the primary changes is to turn off the aerosol retrieval module. The aerosol profiles retrieved inside the ozone code was not helping the ozone retrieval and was adding noise and other artifacts. Aerosols including polar stratospheric cloud (PSC) and polar mesospheric clouds (PMC) have a detectable effect on OMPS-LP data. Our results show that ignoring the aerosol contribution would produce an ozone density bias of up to 10 percent in the region of maximum aerosol extinction. Therefore, aerosol correction is needed to improve the quality of the retrieved ozone concentration profile. We provide Aerosol Scattering Index (ASI) for detecting aerosols-PMC-PSC, defined as ln(Im-Ic) normalized at 45km, where Im is the measured radiance and Ic is the calculated radiance assuming no aerosols. Since ASI varies with wavelengths, latitude and altitude, we can start by assuming no aerosol profiles in calculating the ASIs and then use the aerosol profile to see if it significantly reduces the residuals. We also discuss the effect of aerosol size distribution on the ozone profile retrieval process. Finally, we present an aerosol-PMC-PSC correction scheme.

  7. Chaos detection tools: The LP-VIcode and its applications

    NASA Astrophysics Data System (ADS)

    Darriba, L. A.; Maffione, N. P.; Cincotta, P. M.; Giordano, C. M.

    A very important topic in galactic dynamics is the detection of instabilities of a given system and the possible appearance of chaos. Such a chaotic bahaviour can be detected and studied by means of variational chaos in- dicators (CIs). The CIs are based on the study of the evolution of initial deviation vectors, which makes these techniques specially sensitive to in- dicate the presence of chaos. Notwithstanding their special sensitiveness to identify chaos, the CIs are still good alternatives to determine also the resonance web. On the other hand, the so-called spectral analysis methods are based on the study of some quantity (e.g. the frequency) on a single orbit, which turns these techniques very efficient for the determination of the resonant struc- ture of the system. The analysis of the interaction among chaotic and regular components as well as the determination of the resonant structure of the Hamiltonian leads to a deeper understanding of the system's dynamics. Despite the advan- tages of the simultaneous application of both types of techniques, many researchers keep applying only one of them. Herein, we present an alpha version of a program coded in Fortran, the LP-VIcode. Although the code is in a developing stage, it can compute several CIs, and here we apply it together with the Frequency Modified Fourier Transform (FMFT) (Sidlichovský & Nesvorný 1996) to study the stationary space (Schwarzchild 1993) of an average realistic Hamiltonian model (Muzzio et al. 2005). Using the LP-VIcode, in Maffione et al. (2011b) and Darriba et al. (sub- mitted) the authors suggest an efficient package of CIs to study a general Hamiltonian. Here the research is extended to show that the complemen- tary use of the LP-VIcode and the spectral analysis methods is highly rec- ommended to study a realistic Hamiltonian model.

  8. EBNA-LP Associates with Cellular Proteins Including DNA-PK and HA95

    PubMed Central

    Han, Innoc; Harada, Shizuko; Weaver, David; Xue, Yong; Lane, William; Orstavik, Sigurd; Skalhegg, Bjorn; Kieff, Elliott

    2001-01-01

    EBNA-LP-associated proteins were identified by sequencing proteins that immunoprecipitated with Flag epitope-tagged EBNA-LP (FLP) from lymphoblasts in which FLP was stably expressed. The association of EBNA-LP with Hsp70 (72/73) was confirmed, and sequences of DNA-PK catalytic subunit (DNA-PKcs), HA95, Hsp27, prolyl 4-hydroxylase α-1 subunit, α-tubulin, and β-tubulin were identified. The fraction of total cellular HA95 that associated with FLP was very high, while progressively lower fractions of the total DNA-PKcs, Hsp70, Hsp 27, α-tubulin, and β-tubulin specifically associated with EBNA-LP as determined by immunoblotting with antibodies to these proteins. EBNA-LP bound to two domains in the DNA-PKcs C terminus and DNA-PKcs associated with the EBNA-LP repeat domain. DNA-PKcs that was bound to EBNA-LP phosphorylated p53 or EBNA-LP in vitro, and the phosphorylation of EBNA-LP was inhibited by Wortmannin, a specific in vitro inhibitor of DNA-PKcs. PMID:11160753

  9. Assessment of surgical portosystemic shunts and associated complications: The diagnostic and therapeutic role of radiologists.

    PubMed

    Taslakian, Bedros; Faraj, Walid; Khalife, Mohammad; Al-Kutoubi, Aghiad; El-Merhi, Fadi; Saade, Charbel; Hallal, Ali; Haydar, Ali

    2015-08-01

    Surgical portosystemic shunting, the formation of a vascular connection between the portal and systemic venous circulation, has been used as a treatment to reduce portal venous pressure. Although the use of portosystemic shunt surgery in the management of portal hypertension has declined during the past decade in favour of alternative therapies, and subsequently surgeons and radiologists became less familiar with the procedure, it remains a well-established treatment. Knowledge of different types of surgical portosystemic shunts, their pathophysiology and complications will help radiologists improve communication with surgeons and enhance their understanding of the diagnostic and therapeutic role of radiology in the assessment and management of these shunts. Optimal assessment of the shunt is essential to determine its patency and allow timely intervention. Both non-invasive and invasive imaging modalities complement each other in the evaluation of surgical portosystemic shunts. Interventional radiology plays an important role in the management of complications, such as shunt thrombosis and stenosis. This article describes the various types of surgical portosystemic shunts, explains the anatomy and pathophysiology of these shunts, illustrates the pearls and pitfalls of different imaging modalities in the assessment of these shunts and demonstrates the role of radiologists in the interventional management of complications.

  10. Listeria monocytogenes: a rare complication of ventriculoperitoneal shunt in children.

    PubMed

    Le Monnier, Alban; Blanot, Stéphane; Abachin, Eric; Beretti, Jean-Luc; Berche, Patrick; Kayal, Samer

    2011-11-01

    We report a case of ventriculoperitoneal (VP) shunt infection in a 3-year-old boy caused by the food-borne pathogen Listeria monocytogenes, subsequent to acute peritonitis. This unusual presentation of central nervous system (CNS) listeriosis underlines the ability of the bacteria to form and survive within biofilms on indwelling medical devices. Bacterial persistence may lead to treatment failure and spreading. We highlight the helpfulness of specific quantitative real-time PCR for the hly gene (PCR-hly) for the diagnosis and follow-up of such infections in detecting bacterial persistence within medical devices despite effective antibiotic treatment. Only the surgical replacement of the VP shunt will resolve the infection.

  11. Growth of basilar artery aneurysm after ventriculo-peritoneal shunt.

    PubMed

    Kim, Myoung Soo; Oh, Chang-Wan; Han, Dae Hee

    2002-11-01

    We report upon two cases of obstructive hydrocephalus produced by giant basilar artery aneurysms. They initially presented with symptoms of increased intracranial pressure, and were managed by a ventriculo-peritoneal (VP) shunt with good symptomatic improvement. With time, however, both showed a gradual deterioration of clinical symptoms due to increased aneurysm size. One, with a basilar tip aneurysm was treated by direct neck-clipping of the aneurysm, and was able to return to work. In the other patient, with a basilar trunk aneurysm, endovascular occlusion of one vertebral artery was attempted in an effort to decrease the aneurysm size, but the aneurysm enlarged precipitating brain stem failure. In conclusion, these cases reveal the risk of the VP shunt, which may induce aneurysmal growth, leading to clinical devastation, and emphasize the importance of definitive treatment for giant cerebral aneurysms whenever possible.

  12. Protein adsorption to hydrocephalus shunt catheters: CSF protein adsorption

    PubMed Central

    Brydon, H.; Keir, G.; Thompson, E.; Bayston, R.; Hayward, R.; Harkness, W.

    1998-01-01

    OBJECTIVE—To assess the quantity and nature of the proteins that adsorb to hydrocephalus shunt catheters after implantation, and to determine whether sufficient could accumulate to obstruct the catheter.
DESIGN—Elution of proteins from 102 explanted shunt catheters, with protein assay and electrophoresis of the eluate, and scanning electron microscopy (SEM) of the catheters.
RESULTS—The amount of protein elutable was extremely low, and significant protein, apart from a thin film, was not found on SEM. Qualitative analysis disclosed that most of the adsorbed protein was albumin.
CONCLUSIONS—Protein deposition on hydrocephalus catheters does not occur in sufficient quantities to cause catheter obstruction.

 PMID:9598681

  13. Anal extrusion of a ventriculo peritoneal shunt tube: Endoscopic removal.

    PubMed

    Vuyyuru, Sreedhar; Ravuri, Sreenivas R; Tandra, Vamsidhar R; Panigrahi, Manas K

    2009-07-01

    We describe the extrusion of a ventriculo peritoneal shunt tube from the anus into a 6-year-old boy following the placement of a ventriculo peritoneal shunt for postoperative periventricular tumor-induced hydrocephalus. He was admitted with a complaint of extrusion of a tube through anus on and off during bowel evacuation. He was evaluated with an X-ray of the abdomen which was showing a coiled tube in descending and sigmoid colon, confirmed by sigmoidoscopy. The proximal end was exposed for external ventricular drainage and distal end was removed endoscopically. The patient was watched for peritonitis and managed conservatively. The proximal end of the tube was removed after 5 days of external ventricular drainage and after ruling out ventriculitis and meningitis. Bowel perforation by a ventriculo peritoneal tube is a rare complication. Diagnosis is often difficult and delayed. Most of the bowel perforation is seen in young patients. PMID:21887196

  14. Emergency Portacaval Shunt Versus Rescue Portacaval Shunt in a Randomized Controlled Trial of Emergency Treatment of Acutely Bleeding Esophageal Varices in Cirrhosis—Part 3

    PubMed Central

    Isenberg, Jon I.; Wheeler, Henry O.; Haynes, Kevin S.; Jinich-Brook, Horacio; Rapier, Roderick; Vaida, Florin; Hye, Robert J.

    2010-01-01

    Background Emergency treatment of bleeding esophageal varices in cirrhosis is of singular importance because of the high mortality rate. Emergency portacaval shunt is rarely used today because of the belief, unsubstantiated by long-term randomized trials, that it causes frequent portal-systemic encephalopathy and liver failure. Consequently, portacaval shunt has been relegated solely to salvage therapy when endoscopic and pharmacologic therapies have failed. Question: Is the regimen of endoscopic sclerotherapy with rescue portacaval shunt for failure to control bleeding varices superior to emergency portacaval shunt? A unique opportunity to answer this question was provided by a randomized controlled trial of endoscopic sclerotherapy versus emergency portacaval shunt conducted from 1988 to 2005. Methods Unselected consecutive cirrhotic patients with acute bleeding esophageal varices were randomized to endoscopic sclerotherapy (n = 106) or emergency portacaval shunt (n = 105). Diagnostic workup was completed and treatment was initiated within 8 h. Failure of endoscopic sclerotherapy was defined by strict criteria and treated by rescue portacaval shunt (n = 50) whenever possible. Ninety-six percent of patients had more than 10 years of follow-up or until death. Results Comparison of emergency portacaval shunt and endoscopic sclerotherapy followed by rescue portacaval shunt showed the following differences in measurements of outcomes: (1) survival after 5 years (72% versus 22%), 10 years (46% versus 16%), and 15 years (46% versus 0%); (2) median post-shunt survival (6.18 versus 1.99 years); (3) mean requirements of packed red blood cell units (17.85 versus 27.80); (4) incidence of recurrent portal-systemic encephalopathy (15% versus 43%); (5) 5-year change in Child’s class showing improvement (59% versus 19%) or worsening (8% versus 44%); (6) mean quality of life points in which lower is better (13.89 versus 27.89); and (7) mean cost of care per

  15. Could there be light at the end of the tunnel? Mesocaval shunting for refractory esophageal varices in patients with contraindications to transjugular intrahepatic portosystemic shunt

    PubMed Central

    Davis, Jessica; Chun, Albert K; Borum, Marie L

    2016-01-01

    Cirrhotic patients with recurrent variceal bleeds who have failed prior medical and endoscopic therapies and are not transjugular intrahepatic portosystemic shunt candidates face a grim prognosis with limited options. We propose that mesocaval shunting be offered to this group of patients as it has the potential to decrease portal pressures and thus decrease the risk of recurrent variceal bleeding. Mesocaval shunts are stent grafts placed by interventional radiologists between the mesenteric system, most often the superior mesenteric vein, and the inferior vena cava. This allows flow to bypass the congested hepatic system, reducing portal pressures. This technique avoids the general anesthesia and morbidity associated with surgical shunt placement and has been successful in several case reports. In this paper we review the technique, candidate selection, potential pitfalls and benefits of mesocaval shunt placement. PMID:27429715

  16. Could there be light at the end of the tunnel? Mesocaval shunting for refractory esophageal varices in patients with contraindications to transjugular intrahepatic portosystemic shunt.

    PubMed

    Davis, Jessica; Chun, Albert K; Borum, Marie L

    2016-07-01

    Cirrhotic patients with recurrent variceal bleeds who have failed prior medical and endoscopic therapies and are not transjugular intrahepatic portosystemic shunt candidates face a grim prognosis with limited options. We propose that mesocaval shunting be offered to this group of patients as it has the potential to decrease portal pressures and thus decrease the risk of recurrent variceal bleeding. Mesocaval shunts are stent grafts placed by interventional radiologists between the mesenteric system, most often the superior mesenteric vein, and the inferior vena cava. This allows flow to bypass the congested hepatic system, reducing portal pressures. This technique avoids the general anesthesia and morbidity associated with surgical shunt placement and has been successful in several case reports. In this paper we review the technique, candidate selection, potential pitfalls and benefits of mesocaval shunt placement. PMID:27429715

  17. Results of Trabectome Surgery Following Failed Glaucoma Tube Shunt Implantation

    PubMed Central

    Mosaed, Sameh; Chak, Garrick; Haider, Asghar; Lin, Ken Y.; Minckler, Don S.

    2015-01-01

    Abstract To evaluate the safety and efficacy of Trabectome after failed tube shunt surgery. Twenty patients with prior failed tube shunt surgery who underwent Trabectome alone were included. All patients had at least 3 months of follow-up. Outcomes measured included intraocular pressure (IOP), glaucoma medications, and secondary glaucoma surgeries. The success for Kaplan–Meier survival analysis is defined as IOP ≤21 mm Hg, IOP reduced by at least 20% from preoperative IOP, and no secondary glaucoma surgery. Mean preoperative IOP was 23.7 ± 6.4 mm Hg and mean number of glaucoma medications was 3.2 ± 1.5. At 12 months, IOP was reduced to 15.5 ± 3.2 mm Hg (P = 0.05) and number of medications was reduced to 2.4 ± 1.5 (P = 0.44). Survival rate at 12 months was 84% and 3 patients required additional glaucoma surgery with 15 patients reaching 12 months follow-up. Other than failure of IOP control and transient hypotony (IOP < 3 mm Hg) day 1 in 2 cases, there were no adverse events. Trabecular bypass procedures have traditionally been considered an approach appropriate for early-to-moderate glaucoma; however, our study indicates benefit in refractory glaucoma as well. Eyes that are prone to conjunctival scarring and hypertrophic wound healing, such as those who have failed tube shunt surgery, may benefit from procedures that avoid conjunctival incision such as Trabectome. This study indicates potential benefits in this patient population. Trabectome was safe and effective in reducing IOP at 1-year follow-up in patients with prior failed tube shunt surgery, but not effective in reducing medication reliance in these patients. PMID:26222842

  18. Congenital intrahepatic portosystemic shunts: Imaging findings and endovascular management

    PubMed Central

    Chandrasekharan, Rajsekar; Pullara, Sreekumar K; Thomas, Tixon; Kader, Nazar Puthukudiyil; Moorthy, Srikanth

    2016-01-01

    We present two cases of congenital intrahepatic portosystemic shunts in which the right portal vein directly communicated with the inferior venacava (IVC) in one patient and with the hepatic vein in the other. Multiple hepatic nodules consistent with focal nodular hyperplasia (FNH) were seen in the first patient. The second patient presented with recurrent history of hepatic encephalopathy. Percutaneous transhepatic embolization was performed using coils and Amplatz device following which she completely recovered. PMID:27081230

  19. Resonance features of coupled Josephson junctions: radiation and shunting

    NASA Astrophysics Data System (ADS)

    Shukrinov, Yu M.; Seidel, P.; Il'ichev, E.; Nawrocki, W.; Grajcar, M.; Plecenik, P. A.; Rahmonov, I. R.; Kulikov, K.

    2012-11-01

    We study the phase dynamics and the resonance features of coupled Josephson junctions in layered superconductors and their manifestations in the current- voltage characteristics and temporal dependence of the electric charge in the superconducting layers. Results on the effect of the external radiation and shunting of the stack of Josephson junctions by LC-elements are presented. We discuss the ideas concerning the experimental observation of these resonances.

  20. Modified Blalock-Taussig Shunt with an Umbilical Vein Graft

    PubMed Central

    Leão, Luiz Eduardo V.; Andrade, José Carlos S.; Succi, José Ernesto; Cueva, Clotario C.; Ribeiro, Expedito E.; Carvalho, Antonio Carlos C.; Buffolo, Enio

    1985-01-01

    We describe a modification of the Blalock Taussig anastomosis, with the interposition of a glutaraldehyde-tanned umbilical vein graft between the subclavian and pulmonary arteries. This operation was performed in 64 children: 11 were less than 1 month of age (17.2%), and 23 were between 1 and 6 months of age (34.9%). Hospital deaths occurred in six patients—all less than 6 months of age (9.4%). There was no instance of shunt occlusion noted. The clinical course was uneventful among survivors, except for one patient who died of endocarditis in the late postoperative follow-up. The shunt procedure may be performed very rapidly, with minimal dissection, allowing the use of a graft larger than the diameter of the subclavian artery. This modification of the Blalock Taussig operation compares favorably with our previous experience with other shunt procedures and may be considered a valuable alternative in the palliative surgical treatment of several malformations with severe pulmonary oligemia. Images PMID:15227043

  1. Hysteresis Control for Current Harmonics Suppression Using Shunt Active Filter

    NASA Astrophysics Data System (ADS)

    Ahuja, Rajesh Kr; Chauhan, Aasha; Sharma, Sachin

    2012-11-01

    Recently wide spread of power electronic equipment has caused an increase of the harmonic disturbances in the power systems. The nonlinear loads draw harmonic and reactive power components of current from ac mains. Current harmonics generated by nonlinear loads such as adjustable speed drives,static powersupplies and UPS. Thus a perfect compensator is required to avoid the consequences due to harmonics. To overcome problems due to harmonics, Shunt Active Power Filter (SAPF) has been considered extensively. SAPF has better harmonic compensation than the other approaches used for solving the harmonic related problems. The performance of the SAPF depends upon different control strategies. This paper presents the performance analysis of SAPF under most important control strategy namely instantaneous real active and reactive power method (p-q) for extracting reference currents of shunt active filters under unbalanced load condition. Detailed simulations have been carried out considering this control strategy and adequate results were presented. In this paper, harmonic control strategy is applied to compensate the current harmonics in the system. A detailed study about the harmonic control method has been used using shunt active filter technique.

  2. Depiction of ventriculoperitoneal shunt obstruction with single-photon emission computed tomography/computed tomography

    PubMed Central

    Aksoy, Sabire Yılmaz; Vatankulu, Betül; Uslu, Lebriz; Halac, Metin

    2016-01-01

    An 83-year-old male patient with ventriculoperitoneal shunt underwent radionuclide shunt study using single-photon emission computed tomography/computed tomography (SPECT/CT) to evaluate the shunt patency. The planar images showed activity at the cranial region and spinal canal but no significant activity at the peritoneal cavity. However, SPECT/CT images clearly demonstrated accumulation of activity at the superior part of bifurcation level with no activity at the distal end of shunt as well as no spilling of radiotracer into the peritoneal cavity indicating shunt obstruction. SPECT/CT makes the interpretation of radionuclide shunt study more accurate and easier as compared with traditional planar images. PMID:27385906

  3. Infection as a cause of peritoneal catheter dysfunction in ventriculo-peritoneal shunting in children.

    PubMed

    Frykberg, T; Olden, L

    1983-12-01

    Peritoneal catheter dysfunction is a significant complication of VP shunting in children. Improvement in technique and material should reduce complications such as detachment and breakage. Shunt infection, even if subclinical, should be suspected as the cause of early peritoneal catheter obstruction, especially if recurrent, as well as in cases of organ perforation. Cultures, prolonged if necessary, should be taken and infection should be treated prior to shunt revision. We have had no recurrence of infection or peritoneal catheter dysfunction after treatment with exteriorization of the infected shunt, antibiotic therapy and insertion of a new shunt on the contralateral side. In infected cases antibiotic therapy, both pre- and intra-operatively, should be a matter of course. With these precautions a better result with the ventriculo-peritoneal shunt should be achieved.

  4. Chemoembolic Hepatopulmonary Shunt Reduction to Allow Safe Yttrium-90 Radioembolization Lobectomy of Hepatocellular Carcinoma

    SciTech Connect

    Gaba, Ron C.; VanMiddlesworth, Kyle A.

    2012-12-15

    Yttrium-90 ({sup 90}Y) radioembolization represents an emerging transcatheter treatment option for the management of hepatocellular carcinoma (HCC). Elevation of the hepatopulmonary shunt fraction risks nontarget radiation to the lungs and may limit the use of {sup 90}Y therapy in patients with locally advanced disease with vascular invasion, who often demonstrate increased shunting. We present two cases in which patients with HCC and portal vein invasion resulting in elevated hepatopulmonary shunt fractions underwent chemoembolic shunt closure to allow safe {sup 90}Y radioembolization. Both patients demonstrated excellent tumor response and patient survival. On this basis, we propose a role for chemoembolic reduction of the lung shunt fraction before {sup 90}Y radioembolization in patients with extensive tumor-related hepatopulmonary shunting.

  5. Development of chronic hepatocerebral degeneration eight years after a distal splenorenal (Warren) shunt.

    PubMed Central

    Bleasel, A F; Waugh, R C; McCaughan, G W

    1989-01-01

    It is well known that chronic encephalopathy may be a major complication after the establishment of a surgical portal caval shunt for an episode of variceal haemorrhage. In an effort to minimise this problem Warren and colleagues developed the distal splenorenal shunt where the portal and mesenteric blood flow to the liver was left intact. It is now recognised, however, that the longterm incidence of encephalopathy may be no different with this type of shunt compared with conventional surgical portal systemic shunts. Acquired chronic hepatocerebral degeneration has not been reported after such a selective shunt. A patient with primary biliary cirrhosis is reported who developed the clinical features of this syndrome eight years after a successful distal splenorenal shunt. Images Fig. 1 Fig. 2 PMID:2583570

  6. A multi-stack simulation of shunt currents in vanadium redox flow batteries

    NASA Astrophysics Data System (ADS)

    Wandschneider, F. T.; Röhm, S.; Fischer, P.; Pinkwart, K.; Tübke, J.; Nirschl, H.

    2014-09-01

    A model for the shunt currents in an all-vanadium redox flow battery consisting of 3 stacks which are electrically connected in series. It is based on an equivalent circuit which treats the shunt current pathways as Ohmic resistors. The conductivity of the vanadium electrolyte has been measured for different state-of-charges in order to implement a dependency of the resistances on the state-of-charge of the system. Published results are used to validate the simulation data of a single stack. Three setups of pipe networks are evaluated using the model. The pipe connections between the stacks give rise to external shunt currents, which also increase the amount of shunt currents within the stacks. These connections also lead to a nonuniform distribution of the shunt currents. The effects of the shunt currents on the Coulombic efficiency and the energy efficiency of the system are studied by the means of the model.

  7. Transjugular intrahepatic portosystemic shunt combined with esophagogastric variceal embolization in the treatment of a large gastrorenal shunt

    PubMed Central

    Jiang, Qin; Wang, Ming-Quan; Zhang, Guo-Bing; Wu, Qiong; Xu, Jian-Ming; Kong, De-Run

    2016-01-01

    AIM: To evaluate the efficacy and safety of transjugular intrahepatic portosystemic shunt (TIPS) combined with stomach and esophageal variceal embolization (SEVE) in cirrhotic patients with a large gastrorenal vessel shunt (GRVS). METHODS: Eighty-one cirrhotic patients with gastric variceal bleeding (GVB) associated with a GRVS were enrolled in the study and accepted TIPS combined with SEVE (TIPS + SEVE), by which portosystemic pressure gradient (PPG), biochemical, TIPS-related complications, shunt dysfunction, rebleeding, and death were evaluated. RESULTS: The PPGs before TIPS were greater than 12 mmHg in 81 patients. TIPS + SEVE treatment caused a significant decrease in PPG (from 37.97 ± 6.36 mmHg to 28.15 ± 6.52 mmHg, t = 19.22, P < 0.001). The percentage of reduction in PPG was greater than 20% from baseline. There were no significant differences in albumin, alanine aminotransferase, aspartate aminotransferase, bilirubin, prothrombin time, or Child-Pugh score before and after operation. In all patients, rebleeding rates were 3%, 6%, 12%, 18%, and 18% at 1, 3, 6, 12, and 18 mo, respectively. Five patients (6.2%) were diagnosed as having hepatic encephalopathy. The rates of shunt dysfunction were 0%, 4%, 9%, 26%, and 26%, at 1, 3, 6, 12, and 18 mo, respectively. The cumulative survival rates in 1, 3, 6, 12, and 18 mo were 100%, 100%, 95%, 90%, and 90%, respectively. CONCLUSION: Our preliminary results indicated that the efficacy and safety of TIPS + SEVE were satisfactory in cirrhotic patients with GVB associated with a GRVS (GVB + GRVS). PMID:27458505

  8. 77 FR 7572 - Alliance Pipeline L.P.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-13

    ... Energy Regulatory Commission Alliance Pipeline L.P.; Notice of Application Take notice that on January 25, 2012, Alliance Pipeline L.P. filed with the Federal Energy Regulatory Commission an application under... interstate natural gas pipeline lateral designed to connect new natural gas production near Tioga,...

  9. 77 FR 73637 - Alliance Pipeline L.P.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-11

    ... Energy Regulatory Commission Alliance Pipeline L.P.; Notice of Application Take notice that on November 26, 2012, Alliance Pipeline L.P. (Alliance), 800, 605-5 Ave. SW., Calgary, Alberta, Canada T2P 3H5... directed to Brian Troicuk, Manager, Regulatory Affairs, Alliance Pipeline Ltd. on behalf of...

  10. 77 FR 3762 - Magellan Pipeline Company, L.P.; Notice of Petition for Declaratory Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-25

    ... Energy Regulatory Commission Magellan Pipeline Company, L.P.; Notice of Petition for Declaratory Order... Commission's (Commission) Rules of Practice and Procedure, 18 CFR 385.207(a)(2)(2011), Magellan Pipeline Company, L.P. (Magellan) filed a petition for a declaratory order that approves priority committed...

  11. 77 FR 36527 - Enstor Katy Storage and Transportation, L.P.; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Enstor Katy Storage and Transportation, L.P.; Notice of Filing Take notice that on June 12, 2012, Enstor Katy Storage and Transportation, L.P. filed to revise its Statement...

  12. 76 FR 61682 - Panhandle Eastern Pipe Line Company, LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-05

    ... Energy Regulatory Commission Panhandle Eastern Pipe Line Company, LP; Notice of Application On September 16, 2011, Panhandle Eastern Pipe Line Company, LP (Panhandle) filed with the Federal Energy... filing is accessible on-line at http://www.ferc.gov .using the ``eLibrary'' link and is available...

  13. 78 FR 11639 - Houston Pipe Line Company LP; Notice of Petition for Rate Approval

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-19

    ... Federal Energy Regulatory Commission Houston Pipe Line Company LP; Notice of Petition for Rate Approval Take notice that on February 1, 2013, Houston Pipe Line Company LP (HPL) filed for approval of rates... Commission, 888 First Street NE., Washington, DC 20426. This filing is accessible on-line at...

  14. Automated Test Assembly Using lp_Solve Version 5.5 in R

    ERIC Educational Resources Information Center

    Diao, Qi; van der Linden, Wim J.

    2011-01-01

    This article reviews the use of the software program lp_solve version 5.5 for solving mixed-integer automated test assembly (ATA) problems. The program is freely available under Lesser General Public License 2 (LGPL2). It can be called from the statistical language R using the lpSolveAPI interface. Three empirical problems are presented to…

  15. 78 FR 14778 - Application to Export Electric Energy; Shell Energy North America (US), L.P.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-07

    ... Application to Export Electric Energy; Shell Energy North America (US), L.P. AGENCY: Office of Electricity... (US), L.P. (Shell Energy) has applied to renew its authority to transmit electric energy from the..., which authorized Shell Energy to transmit electric energy from the United States to Mexico as a...

  16. 78 FR 14779 - Application to Export Electric Energy; Shell Energy North America (US), L.P.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-07

    ... Application to Export Electric Energy; Shell Energy North America (US), L.P. AGENCY: Office of Electricity... (US), L.P. (Shell Energy) has applied to renew its authority to transmit electric energy from the..., which authorized Shell Energy to transmit electric energy from the United States to Canada as a...

  17. 78 FR 71601 - Shell Pipeline Company LP; Notice of Petition for Declaratory Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Shell Pipeline Company LP; Notice of Petition for Declaratory Order Take... Procedure, 18 CFR 385.207(a)(2)(2013), Shell Pipeline Company LP (SPLC) filed a petition requesting...

  18. 77 FR 50492 - Notice of Petition for Declaratory Order; Shell Pipeline Company LP

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Notice of Petition for Declaratory Order; Shell Pipeline Company LP Take notice that on August 10, 2012, pursuant to Rule 207(a)(2), Shell Pipeline Company LP submitted...

  19. 77 FR 32069 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-31

    ... Procedures (44 FR 11034, February 26, 1979); 3. Will not affect intrastate aviation in Alaska; and 4. Will... Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd.) Airplanes AGENCY... propose to adopt a new airworthiness directive (AD) for certain Gulfstream Aerospace LP (Type...

  20. 29 CFR 1926.153 - Liquefied petroleum gas (LP-Gas).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... published in 49 CFR part 178, Shipping Container Specifications. (3) Definition. As used in this section... 29 Labor 8 2013-07-01 2013-07-01 false Liquefied petroleum gas (LP-Gas). 1926.153 Section 1926.153... § 1926.153 Liquefied petroleum gas (LP-Gas). (a) Approval of equipment and systems. (1) Each system...

  1. 29 CFR 1926.153 - Liquefied petroleum gas (LP-Gas).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... published in 49 CFR part 178, Shipping Container Specifications. (3) Definition. As used in this section... 29 Labor 8 2011-07-01 2011-07-01 false Liquefied petroleum gas (LP-Gas). 1926.153 Section 1926.153... § 1926.153 Liquefied petroleum gas (LP-Gas). (a) Approval of equipment and systems. (1) Each system...

  2. 29 CFR 1926.153 - Liquefied petroleum gas (LP-Gas).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... published in 49 CFR part 178, Shipping Container Specifications. (3) Definition. As used in this section... 29 Labor 8 2014-07-01 2014-07-01 false Liquefied petroleum gas (LP-Gas). 1926.153 Section 1926.153... § 1926.153 Liquefied petroleum gas (LP-Gas). (a) Approval of equipment and systems. (1) Each system...

  3. 29 CFR 1926.153 - Liquefied petroleum gas (LP-Gas).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... published in 49 CFR part 178, Shipping Container Specifications. (3) Definition. As used in this section... 29 Labor 8 2012-07-01 2012-07-01 false Liquefied petroleum gas (LP-Gas). 1926.153 Section 1926.153... § 1926.153 Liquefied petroleum gas (LP-Gas). (a) Approval of equipment and systems. (1) Each system...

  4. 29 CFR 1926.153 - Liquefied petroleum gas (LP-Gas).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... published in 49 CFR Part 178, Shipping Container Specifications. (3) Definition. As used in this section... 29 Labor 8 2010-07-01 2010-07-01 false Liquefied petroleum gas (LP-Gas). 1926.153 Section 1926.153... § 1926.153 Liquefied petroleum gas (LP-Gas). (a) Approval of equipment and systems. (1) Each system...

  5. 78 FR 21929 - TexStar Crude Oil Pipeline, LP; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission TexStar Crude Oil Pipeline, LP; Notice of Filing Take notice that on March 26, 2013, TexStar Crude Oil Pipeline, LP (TexStar) submitted to the Federal Energy...

  6. 77 FR 68118 - TexStar Transmission, LP; Notice of Petition for Rate Approval

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-15

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF ENERGY Federal Energy Regulatory Commission TexStar Transmission, LP; Notice of Petition for Rate Approval Take notice that on November 2, 2012, TexStar Transmission, LP (TexStar) filed a Petition for Rate...

  7. 78 FR 1850 - Gulf South Pipeline Company, LP; Notice of Application for Abandonment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Gulf South Pipeline Company, LP; Notice of Application for Abandonment Take notice that on December 19, 2012, Gulf South Pipeline Company, LP (Gulf South), 9 Greenway Plaza,...

  8. 77 FR 12868 - Approval of Saybolt LP, as a Commercial Gauger

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-02

    ... SECURITY U.S. Customs and Border Protection Approval of Saybolt LP, as a Commercial Gauger AGENCY: U.S. Customs and Border Protection, Department of Homeland Security. ACTION: Notice of approval of Saybolt LP....13. Anyone wishing to employ this entity to conduct gauger services should request and...

  9. 78 FR 16540 - AIP Series Trust and Morgan Stanley AIP GP LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-15

    ... COMMISSION AIP Series Trust and Morgan Stanley AIP GP LP; Notice of Application March 11, 2013. AGENCY...: AIP Series Trust (the ``Trust'') and Morgan Stanley AIP GP LP (the ``Adviser''). DATES: Filing Dates...., Washington, DC 20549-1090. Applicants, c/ o Stefanie V. Chang Yu, Morgan Stanley Investment Management...

  10. 77 FR 12867 - Accreditation of Saybolt LP, as a Commercial Laboratory

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-02

    ... SECURITY U.S. Customs and Border Protection Accreditation of Saybolt LP, as a Commercial Laboratory AGENCY... of Saybolt LP, as a commercial laboratory. SUMMARY: Notice is hereby given that, pursuant to 19 CFR... provisions of 19 CFR 151.12. Anyone wishing to employ this entity to conduct laboratory analyses...

  11. 76 FR 28221 - Trans-Union Interstate Pipeline, L.P.; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-16

    ... Energy Regulatory Commission Trans-Union Interstate Pipeline, L.P.; Notice of Filing Take notice that on April 7, 2011 Trans-Union Interstate Pipeline, L.P. submitted a request for a waiver of the reporting...-8659. Comment Date: June 9, 2011. Dated: May 10, 2011. Kimberly Bose, Secretary. BILLING CODE 6717-01-P...

  12. 78 FR 16845 - Equitrans, L.P.; Equitable Gas Company, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-19

    ... Energy Regulatory Commission Equitrans, L.P.; Equitable Gas Company, LLC; Notice of Application Take notice that on March 1, 2013, Equitrans, L.P. (Equitrans), 625 Liberty Avenue, Suite 1700, Pittsburgh...: 5:00 p.m. Eastern Time on April 2, 2013. Dated: March 12, 2013. Kimberly D. Bose, Secretary....

  13. 77 FR 44610 - Enbridge Pipelines (North Texas) L.P.; Notice of Compliance Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-30

    ... Federal Energy Regulatory Commission Enbridge Pipelines (North Texas) L.P.; Notice of Compliance Filing Take notice that on July 13, 2012, Enbridge Pipelines (North Texas) L.P. filed a revised Statement of... TTY, call (202) 502-8659. Comment Date: 5:00 p.m. Eastern Time on Monday, July 30, 2012. Dated:...

  14. 76 FR 40723 - Dominion Cove Point LNG, LP; Notice of Technical Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Dominion Cove Point LNG, LP; Notice of Technical Conference On May 27, 2011, pursuant to section 4 of the Natural Gas Act (NGA), Dominion Cove Point LNG, LP (Cove Point) filed...

  15. 77 FR 71585 - Brookfield Energy Marketing LP v. ISO New England Inc.; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-03

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Brookfield Energy Marketing LP v. ISO New England Inc.; Notice of... of the Federal Power Act, 16 U.S.C. 824(e) and 825(e), Brookfield Energy Marketing LP...

  16. 78 FR 30911 - Texas Eastern Transmission, LP; Prior Notice Activity Under Blanket Certificate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-23

    ... Energy Regulatory Commission Texas Eastern Transmission, LP; Prior Notice Activity Under Blanket Certificate On May 8, 2013, Texas Eastern Transmission, LP (Texas Eastern), filed a prior notice request... Act, and Texas Eastern's blanket certificate issued in Docket No. CP82-535-000. Texas Eastern...

  17. 77 FR 74182 - Magic Valley Pipeline, L.P.; Notice of Petition for Rate Approval

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Magic Valley Pipeline, L.P.; Notice of Petition for Rate Approval Take notice that on November 30, 2012, Magic Valley Pipeline, L.P. (Magic Valley) filed a petition for...

  18. 75 FR 35017 - Brookfield Energy Marketing LP; Supplemental Notice That Initial Market-Based Rate Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ... Energy Regulatory Commission Brookfield Energy Marketing LP; Supplemental Notice That Initial Market... supplemental notice in the above-referenced proceeding of Brookfield Energy Marketing LP's application for... the FERC Online links at http://www.ferc.gov . To facilitate electronic service, persons with...

  19. 77 FR 26585 - Steel Partners Holdings L.P.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-04

    ... COMMISSION Steel Partners Holdings L.P.; Notice of Application April 27, 2012. AGENCY: Securities and... Investment Company Act of 1940 (``Act''). Summary of Application: Steel Partners Holdings L.P. (``SPH... its acquisition of WebBank in 1998 until July 14, 2009. 2. Prior to December 2008, Steel Partners...

  20. 77 FR 13593 - PowerSmith Cogeneration Project, LP; Notice of Request for Waiver

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-07

    ... Energy Regulatory Commission PowerSmith Cogeneration Project, LP; Notice of Request for Waiver Take... Act of 1978 (PURPA), as amended, 18 CFR 292.205(c), PowerSmith Cogeneration Project, LP (PowerSmith...-205(a)(1) of the Commission's Regulations for the topping- cycle cogeneration facility owned...

  1. 76 FR 4648 - PowerSmith Cogeneration Project, LP; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-26

    ... Energy Regulatory Commission PowerSmith Cogeneration Project, LP; Notice of Filing January 19, 2011. Take notice that on January 13, 2011, PowerSmith Cogeneration Project, LP (PowerSmith), pursuant to section... Regulations for the topping-cycle cogeneration facility owned and operated by PowerSmith located in...

  2. 77 FR 74280 - Proposed Information Collection (Learner's Perception (LP) Survey); Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-13

    ... AFFAIRS Proposed Information Collection (Learner's Perception (LP) Survey); Comment Request AGENCY.... Title: Learner's Perception (LP) Survey, VA Form 10-0439. OMB Control Number: 2900-0691. Type of Review... trainees perception of their clinical experience with VA versus non-VA facilities. VA will use the data...

  3. 78 FR 11965 - Agency Information Collection (Learner's Perception (LP) Survey) Activities Under OMB Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-20

    ... AFFAIRS Agency Information Collection (Learner's Perception (LP) Survey) Activities Under OMB Review...'s Perception (LP) Survey, VA Form 10-0439. OMB Control Number: 2900-0691. Type of Review: Extension... trainees perception of their clinical experience with VA versus non-VA facilities. VA will use the data...

  4. 76 FR 28026 - TransCanada Keystone Pipeline, LP; Notice of Request for Waiver

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-13

    ... Energy Regulatory Commission TransCanada Keystone Pipeline, LP; Notice of Request for Waiver Take notice that on May 2, 2011, TransCanada Keystone Pipeline, LP (TransCanada Keystone) filed a request for... changes to its committed rates. TransCanada Keystone states that good cause exists to grant such a...

  5. 77 FR 63813 - Sunoco Pipeline L.P.; Notice of Petition for Declaratory Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-17

    ... Energy Regulatory Commission Sunoco Pipeline L.P.; Notice of Petition for Declaratory Order Take notice... Procedure, 18 CFR 385.207(a)(2)(2012), Sunoco Pipeline L.P. (``SPLP''), filed a petition seeking a... the Commission's Rules of Practice and Procedure (18 CFR 385.211 and 385.214) on or before 5:00...

  6. 78 FR 36182 - Calpine Texas Pipeline, L.P.; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-17

    ... Energy Regulatory Commission Calpine Texas Pipeline, L.P.; Notice of Filing Take notice that on June 7, 2013, Calpine Texas Pipeline, L.P. filed to cancel its Statement of Operating Conditions and rates for...-8659. Comment Date: 5:00 p.m. Eastern Time on Friday, June 21, 2013. Dated: June 10, 2013. Kimberly...

  7. 75 FR 27774 - Eagle Rock Desoto Pipeline, L.P.; Notice of Rate Election

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-18

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Eagle Rock Desoto Pipeline, L.P.; Notice of Rate Election May 11, 2010. Take notice that on May 3, 2010, Eagle Rock Desoto Pipeline, L.P., (Desoto) filed a Notice of Rate...

  8. 76 FR 20971 - Eagle Rock Desoto Pipeline, L.P.; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-14

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Eagle Rock Desoto Pipeline, L.P.; Notice of Filing Take notice that on April 7, 2011, Eagle Rock Desoto Pipeline, L.P. filed a revised Statement of Operating Conditions...

  9. 78 FR 13661 - Energy Transfer Fuel, LP; Notice of Petition for Rate Approval

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Energy Transfer Fuel, LP; Notice of Petition for Rate Approval Take notice that on February 15, 2013, Energy Transfer Fuel, LP filed for approval of rates for...

  10. 78 FR 69078 - Houston Pipe Line Company LP; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-18

    ... Energy Regulatory Commission Houston Pipe Line Company LP; Notice of Application Take notice that on October 28, 2013, Houston Pipe Line Company LP (HPL), 1300 Main Street, Houston, Texas 77002, filed an... open to public inspection. This filing is available for review at the Commission in the...

  11. 75 FR 74713 - Panhandle Eastern Pipe Line Company, LP; Notice of Request Under Blanket Authorization

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-01

    ... Energy Regulatory Commission Panhandle Eastern Pipe Line Company, LP; Notice of Request Under Blanket Authorization November 23, 2010. Take notice that on November 12, 2010, Panhandle Eastern Pipe Line Company, LP..., Missouri. Panhandle states that a portion of the pipe underlying Boller Lane will be grouted while...

  12. 77 FR 28375 - Eagle Rock Desoto Pipeline, L.P.; Notice of Petition for Rate Approval

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-14

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Eagle Rock Desoto Pipeline, L.P.; Notice of Petition for Rate Approval Take notice that on May 1, 2012, Eagle Rock Desoto Pipeline, L.P. (Desoto) filed a Rate Election pursuant to 284.123(b)(1) of the...

  13. 75 FR 63452 - Lobo Pipeline Company L.P.; Notice of Baseline Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Lobo Pipeline Company L.P.; Notice of Baseline Filing October 7, 2010. Take notice that on October 1, 2010, Lobo Pipeline Company L.P. submitted a revised baseline filing of its Statement of Operating Conditions...

  14. 77 FR 70432 - Magic Valley Pipeline, L.P.; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-26

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Magic Valley Pipeline, L.P.; Notice of Filing Take notice that on November 15, 2012, Magic Valley Pipeline, L.P. (Magic Valley) filed to revise its Statement of Operating Conditions (SOC) to reflect among other...

  15. 76 FR 81925 - Freeport LNG Development, L.P.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Freeport LNG Development, L.P.; Notice of Application Take notice that on December 9, 2011, Freeport LNG Development, L.P. (Freeport LNG), filed an application pursuant to Section 3(a) of the Natural Gas Act and...

  16. 78 FR 18973 - Bridgeline Holdings, L.P.; Notice of Petition for Rate Approval

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Bridgeline Holdings, L.P.; Notice of Petition for Rate Approval Take notice that on February 28, 2013, as supplemented on March 12, 2013, Bridgeline Holdings, L.P. filed for approval of rates for transportation...

  17. CSF hydrothorax without intrathoracic catheter migration in children with ventriculoperitoneal shunt

    PubMed Central

    Kim, Joon-Hyung; Roberts, David W.; Bauer, David F.

    2015-01-01

    Background: Thoracic complications of ventriculoperitoneal (VP) shunts have been extensively reported in the literature. Cerebrospinal fluid (CSF) hydrothorax without catheter migration, however, has been rarely described and poorly understood. Case Description: We describe development of pleural effusion and respiratory distress in a 3-year-old boy with no evidence of VP shunt catheter displacement on plain radiograph and stable ventricle size on rapid sequence magnetic resonance imaging (MRI) brain. Chest X-ray revealed complete opacity of right hemithorax. Pleural effusion was consistent with transudate. Beta-2 transferrin returned positive. The patient underwent externalization of VP shunt, and upon resolution of effusion, re-internalization with new distal shunt catheter. A literature review of CSF hydrothorax in children without intrathoracic shunt migration was performed. Eleven cases were identified in the English literature. Age at VP shunt placement ranged from birth to 8 years of age. Interval from VP shunt placement to CSF hydrothorax ranged from 1.5 months to 5 years. History of shunt revision was reported in two cases. Presenting symptoms also included ascites and inguinal hernia or hydrocele. Reported diagnostic studies consist of CSF culture, radionuclide shuntogram, beta-2 transferrin, and beta-trace protein. Laterality of the VP shunt and development of pleural effusion were predominantly right sided. Definitive surgical treatment included VA shunt, repositioning of the peritoneal catheter, and endoscopic choroid plexus coagulation. Conclusion: CSF hydrothorax is a rare thoracic complication of VP shunt placement with no radiographic evidence of shunt migration or malfunction. Postulated mechanisms include limited peritoneal capacity to resorb CSF in children and microscopic communications present in congenital diaphragmatic hiatuses. PMID:26236552

  18. The complementary role of plain radiographs and radionuclide shuntography in evaluating CSF-VP shunts.

    PubMed

    Blair, K; AuCoin, R; Kloiber, R; Molnar, C P

    1989-02-01

    Cerebrospinal fluid-ventriculoperitoneal shunts are often used in the treatment of hydrocephalus in children. Many complications can arise that may lead to shunt malfunction, including detachment of the distal limb of the shunt. A case is presented where such a complication occurred with distal migration of the detached tubing into the abdomen, which resulted in a patent subcutaneous tract through which cerebrospinal fluid could drain. The need for radiographic correlation at the time of radionuclide shuntography is stressed.

  19. Treatment and microbiology of repeated cerebrospinal fluid shunt infections in children

    PubMed Central

    Tuan, Teresa J; Thorell, Emily A; Hamblett, Nicole Mayer; Kestle, John R. W.; Rosenfeld, Margaret; Simon, Tamara D

    2011-01-01

    Background A small group of children have second and even more cerebrospinal fluid (CSF) shunt infections (SI). We sought to describe the treatment approaches used for, and the microbiology of, repeated shunt infections. Methods The study population included 31 children with second shunt infection (SI-2) among those undergoing initial CSF shunt placement and treatment for initial infection at Primary Children’s Medical Center. CSF shunt infection was defined as: 1) presence of bacteria in Gram stain and/or culture of CSF, wound, and/or pseudocyst; 2) visible hardware; or 3) abdominal pseudocyst; or (4) presence of bacteria in a blood culture in children with a ventriculoatrial shunt. Infection rates were generated using per-patient denominators, and the concordance of organisms across infections was summarized. Results Of the 31 children with SI-2, most were less than 6 months of age at initial shunt placement (81%), male (77%), and with ventriculoperitoneal shunts (71%). Eighteen developed SI-3 and 8 developed SI-4. Infection rates were 60% (95% confidence interval (CI): 42–75%, n=18/30) for SI-3 and 47% (95% CI: 26–69%, n=8/17) for SI-4. The median time to SI-3 was 477 days (range 5–828) and to SI-4 was 2137 days (range 9–2137). Gram-positive organisms predominated (93% of SI-2, 94% of SI-3). The majority of second shunt infections demonstrated Gram-stain concordance with both the initial (first) shunt infection (58%, 95% CI: 41–74%) and with the following (third) shunt infection (78%, 95% CI: 55–91%). Conclusions Children with second shunt infection experience high subsequent re-infection rates with a long time to re-infection. PMID:21852762

  20. Reversibility of intrapulmonary arteriovenous shunts in liver cirrhosis documented by serial radionuclide perfusion lung scans

    SciTech Connect

    Chen, N.S.; Barnett, C.A.; Farrer, P.A.

    1984-05-01

    Using serial perfusion lung scans, the opening up and closure of right-to-left intrapulmonary arteriovenous shunts has been documented over a period of several weeks in a patient with chronic alcoholic liver disease. The presence of the shunts correlates well with the severity of hypoxemia and the presence of nodular mottling on chest radiographs. The time course of these changes with clinical status suggests lability and the functional nature of these shunts.

  1. Thermal-hydraulic post-test analysis of OECD LOFT LP-FP-2 experiment

    SciTech Connect

    Pena, J.J. ); Enciso, S. ); Reventos, F. )

    1992-04-01

    An assessment of RELAP5/MOD2 and SCDAP/MOD1 against the OECD LOFT experiment LP-FP-2 is presented. LP-FP-2 studies the hypothetical release of fission products and their transport following a large-break LOCA scenario. The report comprises a general description of the LP-FP-2 experiment, a summary of thermal-hydraulic data, a simulation of the LP-FP-2 experiment, results of the RELAP5/MOD2 base calculation, the RELAP5/MOD2 sensitivity analysis, the SCDAP/MOD1 nodalization for an LP-FP-2 experiment, the results of the SCDAP/MOD1 calculation, and the summary and conclusions.

  2. Gold shunt for refractory advanced low-tension glaucoma with spared central acuity

    PubMed Central

    Le, Ryan; Gupta, Neeru

    2016-01-01

    The aim of this study is to report a case of gold shunt surgery for uncontrolled, low-tension glaucoma with good central vision, after having a previously failed trabeculectomy and tube shunt surgeries. The patient was receiving maximum medical glaucoma therapy of four different types with intraocular pressure of 17 mm Hg prior to gold shunt surgery. Five years later, intraocular pressure is well controlled in the low teens without the need for ocular medications, and glaucoma is stable following gold shunt surgery. PMID:27051320

  3. Hydrocele of the canal of Nuck as a result of a rare ventriculoperitoneal shunt complication.

    PubMed

    Yuksel, K Z; Senoglu, M; Yuksel, M; Ozkan, K U

    2006-01-01

    Patients with ventriculoperitoneal (VP) shunts may have multiple complications. Migration of the peritoneal catheter into some anatomical or congenitally open cavities can cause inguinal or genitourinary manifestations such as hernia, hydrocele or acute scrotum, and these are common in male infants. We report a very rare complication of VP shunt encountered in a female infant, manifesting as hydrocele of the canal of Nuck, the female counterpart of hydrocele of the spermatic cord. It is emphasized that VP shunts may also cause clinical inguinal manifestations in female infants, and groin or external genital organ swelling in these patients may be an important sign of shunt malfunction.

  4. Evidence for a patent fibrous tract in fractured, outgrown, or disconnected ventriculoperitoneal shunts.

    PubMed

    Clyde, B L; Albright, A L

    1995-01-01

    As cerebrospinal fluid (CSF) shunts function for several years, outgrowth and disconnection of the distal catheter are seen more frequently. Though a shunt revision is clearly indicated if patients are symptomatic, asymptomatic patients with a disconnection or who have outgrown the distal catheter may no longer require CSF diversion. This follows an assumption that the shunt is no longer functioning and, in an asymptomatic patient, no longer required. However, patent fibrous tracts have been postulated which may allow passage of CSF through disconnected or outgrown distal catheters. We have recently treated 2 patients with ventriculoperitoneal (VP) shunts with evidence of a persistent fibrous tract. A 13-year-old boy was asymptomatic for 2 years after radiographs revealed an outgrown distal VP shunt catheter, after which the acutely deteriorated and died from massive hydrocephalus, although the entire shunt was patent. Another 14-year-old boy who was profoundly retarded presented with subtle changes in his daily activity. Shunt radiographs revealed two disconnections and a broken valve, but a shunt tap revealed a normal opening pressure (OP). A radionuclide shuntogram revealed rapid passage of isotope through fibrous sheaths at the disconnections, and into the peritoneum. A shunt revision was performed and the patient returned to his previous level of health. Patients with outgrown or disconnected distal catheters may be asymptomatic and/or have normal OP, and must not be assumed to have arrested hydrocephalus. A ventricular pressure measurement and radionuclide shuntogram should be performed to rule out a patent persistent fibrous tract.

  5. Persistent portosystemic shunts after deceased donor liver transplant causing episodic hepatic encephalopathy despite good graft function

    PubMed Central

    Barritt, A. Sidney; Fried, Michael W.; Hayashi, Paul H.

    2011-01-01

    We describe two cases of post liver transplant encephalopathy caused by persistent portosystemic shunts despite good graft function. Such recurrence of encephalopathy due to persistent shunting has not been reported in the deceased donor liver transplant literature. Our patients had episodic hepatic encephalopathy concordant with elevated serum ammonia levels due to well documented persistent portosystemic shunts. In one of our cases, the shunt was obliterated via coil embolization. This patient's encephalopathy resolved completely and has not recurred over seven months of follow up. The second patient has declined an intervention, but has remained symptom free on maintenance lactulose and rifaximin. PMID:19655248

  6. PORTACAVAL SHUNT IN PATIENTS WITH CIRRHOSIS—After-Effects of the Operation

    PubMed Central

    Benson, John A.

    1961-01-01

    The subject of the indications for operation for portacaval shunt bristles with problems to which a satisfactory answer cannot yet be given. I have discussed those events which supervene after a portacaval shunt which, in the present state of knowledge, has been directed as proper and well-intentioned therapy. It is against the knowledge of such post-shunt events and the complexity of their management, as well as the success of the operation and the risk of mortality, that one must balance the indications for surgery. This is particularly pertinent to the application of prophylactic shunt surgery now under consideration. PMID:18732366

  7. Robert H. Pudenz (1911-1998) and Ventriculoatrial Shunt: Historical Perspective.

    PubMed

    Konar, Subhas K; Maiti, Tanmoy K; Bir, Shyamal C; Kalakoti, Piyush; Nanda, Anil

    2015-11-01

    Robert H. Pudenz was a renowned neurosurgeon in North America in the 20th century, famous for his contributions in the evolution of the shunt valve and ventriculoatrial shunt surgery. With his innovative idea and help from Heyer, in 1955, he demonstrated that a venous catheter worked best when in the right atrium and that the slit valve should be located at the most distal portion of the shunt system to prevent retrograde filling and thrombosis. He also contributed to various experimental studies on the brain, especially the electrical response of different neural structures. This historical vignette focuses on the work of Robert Pudenz and the evolution of the ventriculoatrial shunt.

  8. Spontaneous knot formation in the peritoneal catheter: a rare cause of ventriculoperitoneal shunt malfunction.

    PubMed

    Charalambides, Constantinos; Sgouros, Spyros

    2012-01-01

    Ventriculoperitoneal shunt malfunction is a relatively common problem encountered in shunted hydrocephalic patients and is attributed most frequently to mechanical obstruction of the ventricular catheter. We present the case of a rare cause of mechanical obstruction of the peritoneal catheter due to the spontaneous formation of a knot just underneath the abdominal wound. This occurred 1 year after shunt implantation and is thought to have been caused by a combination of plastic material memory and bowel peristaltic movements. This case brings for discussion the role of radiographic investigation of the shunt system in children who present with suspected shunt obstruction. Radiographic investigation is warranted in children who have unusual shunt arrangements (e.g., Y-connectors and multiple catheters) in order to exclude disconnections or those who develop shunt problems years after implantation, to exclude material fracture in the neck or migration of any kind. In shunt systems which have been implanted for shorter time periods, the need for radiographs is less apparent. Some surgeons proclaim that when clinical circumstances fall outside the realms of obvious possible proximal obstruction, radiographic evaluation of the shunt system should be considered. PMID:23816925

  9. The role of persistent foramen ovale and other shunts in decompression illness.

    PubMed

    Wilmshurst, Peter T

    2015-06-01

    A persistent foramen ovale (PFO) and other types of right-to-left shunts are associated with neurological, cutaneous and cardiovascular decompression illness (DCI). A right-to-left shunt is particularly likely to be implicated in causation when these types of DCI occur after dives that are not provocative. It is believed that venous nitrogen bubbles that form after decompression pass through the shunt to circumvent the lung filter and invade systemic tissues supersaturated with nitrogen (or other inert gas) and as a result there is peripheral amplification of bubble emboli in those tissues. Approximately a quarter of the population have a PFO, but only a small proportion of the population with the largest right-to-left shunts are at high risk of shunt-mediated DCI. The increased risk of DCI in people with migraine with aura is because migraine with aura is also associated with right-to-left shunts and this increased risk of DCI appears to be confi ned to those with a large PFO or other large shunt. Various ultrasound techniques can be used to detect and assess the size of right-to-left shunts by imaging the appearance of bubble contrast in the systemic circulation after intravenous injection. In divers with a history of shunt-mediated DCI, methods to reduce the risk of recurrence include cessation of diving, modification of future dives to prevent venous bubble liberation and transcatheter closure of a PFO.

  10. The role of persistent foramen ovale and other shunts in decompression illness.

    PubMed

    Wilmshurst, Peter T

    2015-06-01

    A persistent foramen ovale (PFO) and other types of right-to-left shunts are associated with neurological, cutaneous and cardiovascular decompression illness (DCI). A right-to-left shunt is particularly likely to be implicated in causation when these types of DCI occur after dives that are not provocative. It is believed that venous nitrogen bubbles that form after decompression pass through the shunt to circumvent the lung filter and invade systemic tissues supersaturated with nitrogen (or other inert gas) and as a result there is peripheral amplification of bubble emboli in those tissues. Approximately a quarter of the population have a PFO, but only a small proportion of the population with the largest right-to-left shunts are at high risk of shunt-mediated DCI. The increased risk of DCI in people with migraine with aura is because migraine with aura is also associated with right-to-left shunts and this increased risk of DCI appears to be confi ned to those with a large PFO or other large shunt. Various ultrasound techniques can be used to detect and assess the size of right-to-left shunts by imaging the appearance of bubble contrast in the systemic circulation after intravenous injection. In divers with a history of shunt-mediated DCI, methods to reduce the risk of recurrence include cessation of diving, modification of future dives to prevent venous bubble liberation and transcatheter closure of a PFO. PMID:26165532

  11. Optimization of shunt placement for the Norwood surgery using multi-domain modeling.

    PubMed

    Moghadam, Mahdi Esmaily; Migliavacca, Francesco; Vignon-Clementel, Irene E; Hsia, Tain-Yen; Marsden, Alison L

    2012-05-01

    An idealized systemic-to-pulmonary shunt anatomy is parameterized and coupled to a closed loop, lumped parameter network (LPN) in a multidomain model of the Norwood surgical anatomy. The LPN approach is essential for obtaining information on global changes in cardiac output and oxygen delivery resulting from changes in local geometry and physiology. The LPN is fully coupled to a custom 3D finite element solver using a semi-implicit approach to model the heart and downstream circulation. This closed loop multidomain model is then integrated with a fully automated derivative-free optimization algorithm to obtain optimal shunt geometries with variable parameters of shunt diameter, anastomosis location, and angles. Three objective functions: (1) systemic; (2) coronary; and (3) combined systemic and coronary oxygen deliveries are maximized. Results show that a smaller shunt diameter with a distal shunt-brachiocephalic anastomosis is optimal for systemic oxygen delivery, whereas a more proximal anastomosis is optimal for coronary oxygen delivery and a shunt between these two anatomies is optimal for both systemic and coronary oxygen deliveries. Results are used to quantify the origin of blood flow going through the shunt and its relationship with shunt geometry. Results show that coronary artery flow is directly related to shunt position. PMID:22757490

  12. Embolization of portal-systemic shunts in cirrhotic patients with chronic recurrent hepatic encephalopathy

    SciTech Connect

    Sakurabayashi, Shin; Sezai, Shuichi; Yamamoto, Yoshihiro; Hirano, Masanori; Oka, Hiroshi

    1997-03-15

    Purpose. To evaluate the efficacy of embolization of portal-systemic shunts in cirrhotic patients with chronic recurrent hepatic encephalopathy (CRHE). Methods. Seven cirrhotic patients with CRHE refractory to medical treatment (3 men and 4 women, mean age 66 years) were studied. Five patients had splenorenal shunts, 1 had a gastrorenal shunt, and 1 had an intrahepatic portal vein-hepatic vein shunt. Shunt embolization was performed using stainless steel coils, with a percutaneous transhepatic portal vein approach in 4 patients and a transrenal vein approach in 3 patients. Results. After embolization, the shunt disappeared in 4 patients on either ultrasound pulsed Doppler monitoring or portography. Complications observed in the 7 patients were fever, transient pleural effusion, ascites, and mild esophageal varices. For 3-6 months after embolization, the 4 patients whose shunts disappeared showed minimal or no reappearance of a shunt, and had no recurrence of encephalopathy. The serum ammonia levels decreased and electroencephalograms also improved. One of the 4 patients, who developed mild esophageal varices, required no treatment. Treatment was effective in 3 of the 4 patients (75%) who underwent embolization via a transhepatic portal vein. Conclusion. Transvascular embolization of shunts improved the outcome in 4 of 7 patients. The most effective embolization was achieved via the percutaneous transhepatic portal vein approach.

  13. Prediction of the becalmed region for LP turbine profile design

    SciTech Connect

    Schulte, V.; Hodson, H.P.

    1998-10-01

    Recent attention has focused on the so-called ``becalmed region`` that is observed inside the boundary layers of turbomachinery blading and is associated with the process of wake-induced transition. Significant reductions of profile loss have been shown for high lift LP turbine blades at low Reynolds numbers due to the effects of the becalmed region on the diffusing flow at the rear of the suction surface. In this paper the nature and the significance of the becalmed region are examined using experimental observations and computational studies. It is shown that the becalmed region may be modeled using the unsteady laminar boundary layer equations. Therefore, it is predictable independent of the transition or turbulence models employed. The effect of the becalmed region on the transition process is modeled using a spot-based intermittency transition model. An unsteady differential boundary layer code was used to simulate a deterministic experiment involving an isolated turbulent spot numerically. The predictability of the becalmed region means that the rate of entropy production can be calculated in that region. It is found to be of the order of that in a laminar boundary layer. It is for this reason and because the becalmed region may be encroached upon by pursuing turbulent flows that for attached boundary layers, wake-induced transition cannot significantly reduce the profile loss. However, the becalmed region is less prone to separation than a conventional laminar boundary layer. Therefore, the becalmed region may be exploited in order to prevent boundary layer separation and the increase in loss that this entails. It is shown that it should now be possible to design efficient high lift LP turbine blades.

  14. 78 FR 4842 - Linden VFT, LLC v. Brookfield Energy Marketing, LP, Cargill Power Markets, LLC; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Linden VFT, LLC v. Brookfield Energy Marketing, LP, Cargill Power Markets... a formal complaint against Brookfield Energy Marketing, LP and Cargill Power Markets,...

  15. 76 FR 25732 - Emergence Capital Partners SBIC, L.P.; Notice Seeking Exemption Under Section 312 of the Small...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-05

    ...). Emergence Capital Partners SBIC, L.P. proposes to provide equity financing to PivotLink, Inc., 15325 SE... Emergence Capital Partners SBIC, L.P., own more than ten percent of PivotLink, Inc. Therefore,...

  16. Ventriculo-peritoneal shunt malfunction due to complete migration and subgaleal coiling of the proximal and distal catheters.

    PubMed

    Pikis, Stylianos; Cohen, José E; Shoshan, Yigal; Benifla, Mony

    2015-01-01

    Ventriculo-peritoneal (VP) shunt malfunction due to proximal and distal catheter migration has been rarely reported in the literature. Shunt migration has been proposed to occur as a result of a combination of various mechanisms, including the windlass effect, retained memory of the shunt tubing, inadequate shunt fixation, and increased intra-abdominal pressures. We describe a rare case of a 6-week-old child who presented in our department with VP shunt malfunction due to complete proximal migration and coiling of the peritoneal and ventricular VP shunt catheters within a subgaleal pocket at the left occipital area.

  17. 78 FR 62614 - Guttman Energy, Inc., PBF Holding Company LLC v. Buckeye Pipe Line Company, L.P., Laurel Pipe...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ... Energy Regulatory Commission Guttman Energy, Inc., PBF Holding Company LLC v. Buckeye Pipe Line Company, L.P., Laurel Pipe Line Company, L.P.; Notice of Complaint Take notice that on October 15, 2013... Energy Regulatory Commission (Commission) a complaint against Buckeye Pipe Line Company L.P. and...

  18. 77 FR 76586 - Founders Equity SBIC I, L.P.; Notice Seeking Exemption Under Section 312 of the Small Business...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-28

    ... ADMINISTRATION Founders Equity SBIC I, L.P.; Notice Seeking Exemption Under Section 312 of the Small Business Investment Act, Conflicts of Interest Notice is hereby given that Founders Equity SBIC I, L.P., 711 Fifth... Equity SBIC I, L.P. proposes to provide debt security financing to Richardson Foods, Inc., 101 Erie...

  19. 76 FR 76474 - Emergence Capital Partners SBIC, L.P.; Notice Seeking Exemption Under Section 312 of the Small...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ...). Emergence Capital Partners SBIC, L.P. proposes to provide equity financing to Lithium Technologies, Inc., 6121 Hollis Street, Suite 4, Emeryville, CA 94608 (``Lithium''). The financing is contemplated for..., L.P., Associates of Emergence Capital Partners SBIC, L.P., own more than ten percent of...

  20. 76 FR 1491 - Emergence Capital Partners SBIC, L.P. License No. 09/79-0454; Notice Seeking Exemption Under...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-10

    ... PivotLink, Inc., 15325 SE 30th Place, Suite 300, Bellevue, WA 98007. The financing is contemplated for..., L.P., Associates of Emergence Capital Partners SBIC, L.P., own more than ten percent of PivotLink, Inc. Therefore, PivotLink, Inc is considered an Associate of Emergence Capital Partners SBIC, L.P....

  1. Interatrial shunt flow profiles in newborn infants: a colour flow and pulsed Doppler echocardiographic study.

    PubMed Central

    Hiraishi, S; Agata, Y; Saito, K; Oguchi, K; Misawa, H; Fujino, N; Horiguchi, Y; Yashiro, K

    1991-01-01

    Interatrial shunt flow profiles in 36 normal term infants were examined serially by colour flow and pulsed Doppler echocardiographic techniques from within an hour of birth to four or five days after birth. Shunt flow across the foramen ovale was detected in 33 normal infants (92%) within an hour of birth (mean 40 minutes). The occurrence of interatrial shunting decreased with age, but a shunt signal was still detected in 17 infants (47%) on the fourth or fifth day of life, by then the ductus arteriosus had already closed in all the normal infants. The direction of interatrial shunt flow was predominantly left-to-right, but in 64% there was a coexistent small right-to-left shunt in diastole within an hour of birth; by four to five days it was found in 19%. In the six patients with persistent fetal circulation the direction of the interatrial shunt flow was predominantly right-to-left with biphasic peaks in diastole and systole at the early stage of the disease, and the period of right-to-left shunt flow during each cardiac cycle was significantly longer than that in normal infants examined within 1 hour of birth. In all patients the ductus closed before the foramen ovale. At the time of ductal closure in all patients with persistent fetal circulation right-to-left shunt flow was seen during diastole and its period was still prolonged. These findings suggest that interatrial shunting, predominantly left-to-right, is common in normal newborn infants. Evaluation of the characteristics of the interatrial shunt by Doppler echocardiography may be useful for predicting the progress of or improvement in neonates with persistent fetal circulation. Images PMID:1993129

  2. Shunting arc plasma source for pure carbon ion beam.

    PubMed

    Koguchi, H; Sakakita, H; Kiyama, S; Shimada, T; Sato, Y; Hirano, Y

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA∕mm(2) at the peak of the pulse.

  3. Shunting arc plasma source for pure carbon ion beama)

    NASA Astrophysics Data System (ADS)

    Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y.

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm2 at the peak of the pulse.

  4. Laparoscopic removal of dislocated ventriculoperitoneal shunts. Report of two cases.

    PubMed

    Schrenk, P; Woisetschläger, R; Wayand, W U; Polanski, P

    1994-09-01

    In two patients the dislocated abdominal catheter of a ventriculoperitoneal (VP) shunt was successfully removed from the abdominal cavity by laparoscopy. Avoiding laparotomy, only two small abdominal incisions were necessary to insert the laparoscope and the grasping forceps. Postoperative course was uncomplicated except for protrusion of a part of the greater omentum through the umbilical incision in one patient. Both patients were mobilized on the operative day. Surgery required only 10 min, provided an excellent view of the entire abdomen, and led to prompt identification and removal of the lost catheter.

  5. Piezoelectric vibration damping using resonant shunt circuits: an exact solution

    NASA Astrophysics Data System (ADS)

    Soltani, P.; Kerschen, G.; Tondreau, G.; Deraemaeker, A.

    2014-12-01

    The objective of this paper is to propose an exact closed-form solution to the {{H}∞ } optimization of piezoelectric materials shunted with inductive-resistive passive electrical circuits. Realizing that Den Hartog's method which imposes fixed points of equal height in the receptance transfer function is approximate, the parameters of the piezoelectric tuned vibration absorber are calculated through the direct minimization of the maxima of the receptance. The method is applied to a one-degree-of-freedom primary oscillator considering various values of the electromechanical coupling coefficients.

  6. A theoretical and experimental study of coplanar waveguide shunt stubs

    NASA Technical Reports Server (NTRS)

    Dib, Nihad I.; Ponchak, George E.; Katehi, Linda P. B.

    1993-01-01

    A comprehensive theoretical and experimental study of straight and bent coplanar waveguide (CPW) shunt stubs is presented. In the theoretical analysis, the CPW is assumed to be inside a cavity while, the experiments are performed on open structures. For the analysis of CPW discontinuities with air-bridges, a hybrid technique was developed which was validated through extensive theoretical and experimental comparisons. The effect of the cavity resonances on the behavior of the stubs with and without air-bridges is investigated. In addition, the encountered radiation loss due to the discontinuities is evaluated experimentally.

  7. 69 kV shunt capacitor bank specification considerations

    SciTech Connect

    Fenner, G.E. )

    1992-01-01

    PSI has standardized on the 69 kv ungrounded star, 7.2 mvar or multiple of the 7.2 mvar shunt capacitor bank for var control. This document defines the considerations to be addressed when specifying a 69 kv ungrounded capacitor bank and for providing suitable protection. The design goal is to provide a bank that is reliable and meets operational requirements at minimum cost with standard components. The bank components will be discussed separately. This paper defines the considerations for specifying capacitor banks to minimize cost, improve reliability and help standardize design. The components making up the bank will be individually discussed with special emphasis on the protection and control.

  8. RHIC INSERTION REGION, SHUNT POWER SUPPLY CURRENT ERRORS.

    SciTech Connect

    BRUNO,D.; GANETIS,G.; LAMBIASE,R.F.; SANDBERG,J.

    2001-06-18

    The Relativistic Heavy Ion Collider (RHIC) was commissioned in 1999 and 2000. RHIC requires power supplies to supply currents to highly inductive superconducting magnets. The RHIC Insertion Region contain's many shunt power supplies to trim the current of different magnet elements in a large superconducting magnet circuit. Power Supply current error measurements were performed during the commissioning of RHIC. Models of these power supply systems were produced to predict and improve these power supply current errors using the circuit analysis program MicroCap V by Spectrum Software (TM). Results of the power supply current errors are presented from the models and from the measurements performed during the commissioning of RHIC.

  9. Characterization of the apoLp-III/LPS complex: insight in the mode of binding interaction

    PubMed Central

    Oztug, Merve; Martinon, Daisy; Weers, Paul M.M.

    2012-01-01

    Apolipoproteins are able to associate with lipopolysaccharides (LPS), potentially providing protection against septic shock. To gain insight in the molecular details of this binding interaction, apolipophorin III (apoLp-III) from Galleria mellonella was used as a model. The binding of apoLp-III to LPS was optimal around 37–40 °C, close to the LPS phase transition temperature. ApoLp-III formed complexes with LPS from E. coli (serotype O55:B5) with a diameter of 24 nm, a molecular weight of ~390 kDa, containing four molecules of apoLp-III and 24 molecules of LPS. The LPS-bound form of the protein was substantially more resistant to guanidine-induced denaturation compared to unbound protein. The denaturation profile displayed a multiphase character with a steep drop in secondary structure between 0–1 M guanidine, and a slower decrease above 1 M guanidine HCl. In contrast, apoLp-III bound to detoxified LPS was only slightly more resistant to guanidine HCl induced denaturation compared to unbound protein. Analysis of size-exclusion FPLC elution profiles of mixtures of apoLp-III with LPS or detoxified LPS indicated a much weaker binding interaction with detoxified LPS compared to intact LPS. These results indicate that apoLp-III initially interacts with exposed carbohydrate regions, but that the lipid A region is required for a more stable LPS binding interaction. PMID:22779761

  10. Time to First Shunt Failure in Pediatric Patients over 1 Year Old: A 10-Year Retrospective Study.

    PubMed

    Shannon, Chevis N; Carr, Kevin R; Tomycz, Luke; Wellons, John C; Tulipan, Noel

    2013-01-01

    Studies comparing alternatives to ventriculoperitoneal (VP) shunting for treatment of hydrocephalus have often relied upon data from an earlier era that may not be representative of contemporary shunt survival outcomes. We sought to determine the shunt survival rate of our cohort and compare our results to previously published shunt survival and endoscopic third ventriculostomy (ETV) success rates. We identified 95 patients between 1 and 18 years of age, who underwent initial VP shunt placement between January 2001 and December 2010. Our study shows a shunt survival rate of 85% at 6 months and 79% at 2 years, for initial shunts in pediatric patients over 1 year of age in this cohort. The overall infection rate was 3%. This compares favorably with published success rates of ETV at similar time points as well as with the rate of infection. This suggests that ventricular shunting remains a viable alternative to ETV in the older child.

  11. Neural Network Based Modeling and Analysis of LP Control Surface Allocation

    NASA Technical Reports Server (NTRS)

    Langari, Reza; Krishnakumar, Kalmanje; Gundy-Burlet, Karen

    2003-01-01

    This paper presents an approach to interpretive modeling of LP based control allocation in intelligent flight control. The emphasis is placed on a nonlinear interpretation of the LP allocation process as a static map to support analytical study of the resulting closed loop system, albeit in approximate form. The approach makes use of a bi-layer neural network to capture the essential functioning of the LP allocation process. It is further shown via Lyapunov based analysis that under certain relatively mild conditions the resulting closed loop system is stable. Some preliminary conclusions from a study at Ames are stated and directions for further research are given at the conclusion of the paper.

  12. Transcatheter closure of modified Blalock-Taussig shunt with Gianturco-Grifka Vascular Occlusion Device.

    PubMed

    Hoyer, M H; Leon, R A; Fricker, F J

    1999-12-01

    A 15-year-old girl with previous repair of a complex cyanotic congenital heart defect had persistence of a modified left Blalock-Taussig shunt that could not be ligated at surgery. Six years later, antegrade delivery of a Gianturco-Grifka Vascular Occlusion Device resulted in complete closure of the shunt. Cathet. Cardiovasc. Intervent. 48:365-367, 1999. PMID:10559814

  13. Immune reactions associated with silicone-based ventriculo-peritoneal shunt malfunctions in children.

    PubMed

    VandeVord, Pamela J; Gupta, Nalini; Wilson, Russell B; Vinuya, Ricardo Z; Schaefer, Caralee J; Canady, Alexa I; Wooley, Paul H

    2004-08-01

    The implantation of ventriculo-peritoneal (VP) shunting systems is the most commonly performed neurological procedure in children with hydrocephalus. Although the overall complication risk is low, the cumulative risk of shunt failure is high and unfortunately results in a high prevalence of revision surgeries. In this study, we explored the concept that some pediatric patients may develop an immune response to either the proteins attached to the silicone implant surface or to the biomaterial itself, and that this reaction may contribute to VP shunt failure in some individuals. The data displays that the sterile shunt malfunction group had a higher rate of protein deposition and increased levels of autoantibodies to the extracted surface proteins as compared to individuals with functioning shunting systems. The precise nature of the shunt-bound proteins that serve as antigens in this experiment have not yet been determined. The data also indicated that some individuals develop antibodies to polymeric substances that cross-react with partially polymerized acrylamide. The detection of significant amounts of shunt-bound protein, antibody responses to these proteins and to polymeric substances suggest that an immunological response to these proteins may play a role in the mechanism behind sterile shunt malfunctions.

  14. Two episodes of ventriculoperitoneal shunt migration in a patient with idiopathic intracranial hypertension.

    PubMed

    Balakrishnan, V; Jeanmonod, R

    2014-01-01

    Introduction. Ventriculoperitoneal shunts are often placed as treatment for refractory idiopathic intracranial hypertension. Dislodgement and migration of the distal portion of the shunt are more common in obese patients and can be difficult to detect. We report the case of a woman with two separate episodes of shunt migration into her abdominal wall. Case Presentation. We report a case of a 37-year-old female with history of obesity eventually diagnosed with idiopathic intracranial hypertension (IIH) as the cause. She failed outpatient therapy and, through neurosurgery, had a VP shunt placed for symptom control. She had subsequent development of worsened symptoms that were found to be due to shunt migration. This happened not once but twice to the same patient. Conclusion. Shunt dislodgement, migration, and subsequent failure are common in obese patients who have shunts placed for IIH. The medical provider should maintain a high index of suspicion for shunt malfunction in these patients, particularly because clinical evaluation may be challenging due to habitus.

  15. [Migration of a ventriculoperitoneal shunt in the liver: A rare complication].

    PubMed

    Eap, C; Blauwblomme, T; Dupuy, L; Bennis, S; Faber, B; Mireau, E; Aldea, S; Frileux, P; Gaillard, S

    2012-12-01

    We report on a case of migration inside the liver of the distal end of a ventriculoperitoneal shunt catheter in an adult patient. A simple laparotomy permitted the surgical removal with no haemorrhagic complication. We discuss the other cases reported in the literature and we outline the need to perform an abdominal CT scan in patients carrying a VP shunt with digestive symptoms.

  16. Visual disturbance following shunt malfunction in a patient with congenital hydrocephalus.

    PubMed

    Oyama, Hirofumi; Hattori, Kenichi; Kito, Akira; Maki, Hideki; Noda, Tomoyuki; Wada, Kentaro

    2012-01-01

    A 25-year-old woman presented with complaints of nausea and headache. She had been treated with a ventriculoperitoneal shunt for hydrocephalus when she was 7 months old. Her bilateral optic discs showed moderate atrophy. Right visual acuity allowed only perception of hand movement and left visual acuity was 0.02 (1.2). Computed tomography (CT) showed mild ventricular dilation but no periventricular lucency. Intracranial pressure (ICP) was not high when the shunt valve was punctured. Her visual acuity deteriorated 5 days after the consultation. She was referred again 8 days after the first consultation. The bilateral optic discs were completely pale. Both pupils were dilated on admission, and the bilateral direct light reflexes were absent. The patient could slightly detect only green light stimulus. CT showed moderate enlargement of the ventricle. ICP was 47 cmH(2)O when the shunt valve was punctured. Shuntgraphy showed obstruction of the shunt at the distal end of peritoneal catheter. Emergent total shunt revision was performed. She could detect dark stimulus and the still-dilated left pupil had recovered direct light reflex on the next day. The visual acuity was 0.01 (0.7) on the left 6 months after the operation, although she was blind in the right eye and the bilateral optic discs were completely pale. Visual loss associated with shunt failure remains a major morbidity in shunted congenital hydrocephalus. Early diagnosis and shunt revision may allow visual recovery.

  17. Transient right-to-left shunting through a patent foramen ovale secondary to unilateral diaphragmatic paralysis.

    PubMed Central

    Cordero, P. J.; Morales, P.; Mora, V.; Cebrian, J.; Vallterra, J.; Gudin, J.; Benlloch, E.; Marco, V.

    1994-01-01

    A 57 year old patient presented with unilateral diaphragmatic paralysis and severe hypoxaemia secondary to transient right-to-left interatrial shunting through a patent foramen ovale. The final diagnosis was made because of the initial detection of a shunt while the patient was breathing 100% oxygen. Images PMID:7940438

  18. Ventriculoperitoneal shunt for treatment of hydrocephalus in a French bulldog puppy

    PubMed Central

    Giacinti, Jolene A.

    2016-01-01

    A 6.5-week-old bulldog was presented with lethargy, anorexia, and stunted growth. A domed skull, ventrolateral strabismus, hypermetria, and delayed hopping were observed. Congenital hydrocephalus was diagnosed and a ventriculoperitoneal shunt was placed. After surgery, a shunt obstruction occurred but resolved with treatment. The puppy responded well and neurological deficits continued to improve after surgery. PMID:26933271

  19. Normal-pressure hydrocephalus: current understanding of diagnostic tests and shunting

    SciTech Connect

    Black, P.M.

    1982-02-01

    Normal-pressure hydrocephalus is no longer difficult to diagnose or treat-cranial computed tomographic scanning has made the diagnosis of ventricular enlargement straightforward, and shunt placement often helps the patient whose condition can be traced to a specific cause. Predicting accurately whether a patient will benefit from a shunt, however, is still problematic.

  20. 21 CFR 882.5550 - Central nervous system fluid shunt and components.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Central nervous system fluid shunt and components. 882.5550 Section 882.5550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... shunt is a device or combination of devices used to divert fluid from the brain or other part of...

  1. 21 CFR 882.5550 - Central nervous system fluid shunt and components.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Central nervous system fluid shunt and components. 882.5550 Section 882.5550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... shunt is a device or combination of devices used to divert fluid from the brain or other part of...

  2. 21 CFR 882.5550 - Central nervous system fluid shunt and components.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Central nervous system fluid shunt and components. 882.5550 Section 882.5550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... shunt is a device or combination of devices used to divert fluid from the brain or other part of...

  3. Electroacoustic absorbers: bridging the gap between shunt loudspeakers and active sound absorption.

    PubMed

    Lissek, Hervé; Boulandet, Romain; Fleury, Romain

    2011-05-01

    The acoustic impedance at the diaphragm of an electroacoustic transducer can be varied using a range of basic electrical control strategies, amongst which are electrical shunt circuits. These passive shunt techniques are compared to active acoustic feedback techniques for controlling the acoustic impedance of an electroacoustic transducer. The formulation of feedback-based acoustic impedance control reveals formal analogies with shunt strategies, and highlights an original method for synthesizing electric networks ("shunts") with positive or negative components, bridging the gap between passive and active acoustic impedance control. This paper describes the theory unifying all these passive and active acoustic impedance control strategies, introducing the concept of electroacoustic absorbers. The equivalence between shunts and active control is first formalized through the introduction of a one-degree-of-freedom acoustic resonator accounting for both electric shunts and acoustic feedbacks. Conversely, electric networks mimicking the performances of active feedback techniques are introduced, identifying shunts with active impedance control. Simulated acoustic performances are presented, with an emphasis on formal analogies between the different control techniques. Examples of electric shunts are proposed for active sound absorption. Experimental assessments are then presented, and the paper concludes with a general discussion on the concept and potential improvements.

  4. Soluble membrane attack complex is diagnostic for intraventricular shunt infection in children

    PubMed Central

    Ramos, Theresa N.; Arynchyna, Anastasia A.; Blackburn, Tessa E.; Johnston, James M.

    2016-01-01

    BACKGROUND. Children treated with cerebrospinal fluid (CSF) shunts to manage hydrocephalus frequently develop shunt failure and/or infections, conditions that present with overlapping symptoms. The potential life-threatening nature of shunt infections requires rapid diagnosis; however, traditional microbiology is time consuming, expensive, and potentially unreliable. We set out to identify a biomarker that would identify shunt infection. METHODS. CSF was assayed for the soluble membrane attack complex (sMAC) by ELISA in patients with suspected shunt failure or infection. CSF was obtained at the time of initial surgical intervention. Statistical analysis was performed to assess the diagnostic potential of sMAC in pyogenic-infected versus noninfected patients. RESULTS. Children with pyogenic shunt infection had significantly increased sMAC levels compared with noninfected patients (3,211 ± 1,111 ng/ml vs. 26 ± 3.8 ng/ml, P = 0.0001). In infected patients undergoing serial CSF draws, sMAC levels were prognostic for both positive and negative clinical outcomes. Children with delayed, broth-only growth of commensal organisms (P. acnes, S. epidermidis, etc.) had the lowest sMAC levels (7.96 ± 1.7 ng/ml), suggesting contamination rather than shunt infection. CONCLUSION. Elevated CSF sMAC levels are both sensitive and specific for diagnosing pyogenic shunt infection and may serve as a useful prognostic biomarker during recovery from infection. FUNDING. This work was supported in part by the Impact Fund of Children’s of Alabama.

  5. Shunt currents in vanadium flow batteries: Measurement, modelling and implications for efficiency

    NASA Astrophysics Data System (ADS)

    Fink, H.; Remy, M.

    2015-06-01

    Shunt currents are an important factor which must be considered when designing a stack for flow batteries. They lead to a reduction of the coulombic efficiency and can cause furthermore a critical warming of the electrolyte. Shunt currents inevitably appear at bypass connections of the hydraulic system between the single cells of a stack. In this work the shunt currents of a five-celled mini stack of a vanadium flow battery with external hydraulic system and their effects are investigated directly. The external hydraulic system allows the implementation of current sensors for direct measurement of the shunt currents; moreover, the single bypass channels can be interrupted by clamping the tube couplings and with it the shunt currents between the cells when the pumps are off. Thus the shares of losses by cross contamination and by shunt currents are quantified separately by charge conservation measurements. The experimentally gained data are compared to a shunt current model based on a equivalent circuit diagram and the linear equation system derived from it. Experiments and model data are in good agreement. The effects of shunt currents for different flow frame geometries and number of cells in a stack are simulated and presented in this work.

  6. Electroacoustic absorbers: bridging the gap between shunt loudspeakers and active sound absorption.

    PubMed

    Lissek, Hervé; Boulandet, Romain; Fleury, Romain

    2011-05-01

    The acoustic impedance at the diaphragm of an electroacoustic transducer can be varied using a range of basic electrical control strategies, amongst which are electrical shunt circuits. These passive shunt techniques are compared to active acoustic feedback techniques for controlling the acoustic impedance of an electroacoustic transducer. The formulation of feedback-based acoustic impedance control reveals formal analogies with shunt strategies, and highlights an original method for synthesizing electric networks ("shunts") with positive or negative components, bridging the gap between passive and active acoustic impedance control. This paper describes the theory unifying all these passive and active acoustic impedance control strategies, introducing the concept of electroacoustic absorbers. The equivalence between shunts and active control is first formalized through the introduction of a one-degree-of-freedom acoustic resonator accounting for both electric shunts and acoustic feedbacks. Conversely, electric networks mimicking the performances of active feedback techniques are introduced, identifying shunts with active impedance control. Simulated acoustic performances are presented, with an emphasis on formal analogies between the different control techniques. Examples of electric shunts are proposed for active sound absorption. Experimental assessments are then presented, and the paper concludes with a general discussion on the concept and potential improvements. PMID:21568400

  7. Characteristic lesion pattern and echocardiographic findings in extra-cardiac shunt-related stroke.

    PubMed

    Mun, Jun Kyu; Park, Sung Ji; Kim, Suk Jae; Bang, Oh Young; Chung, Chin-Sang; Lee, Kwang Ho; Kim, Gyeong-Moon

    2016-10-15

    Among embolic strokes of undetermined source, under-recognized etiology such as extra-cardiac shunt could be a potential risk factor. We sought to characterize infarction patterns on diffusion-weighted imaging (DWI) and transesophageal echocardiography (TEE) findings in extra-cardiac shunt-related stroke. We enrolled 96 consecutive patients with cryptogenic stroke who had an extra- or intra-cardiac shunt. Diagnosis of the shunt was performed using TEE with agitated saline contrast and pulmonary vein isolation. Infarction patterns on DWI and total lesion volume were analyzed. Bubble amounts through the shunt were classified via the International Consensus Criteria (ICC). Short-term prognosis, patterns and size of DWI lesions, and involved vascular territories were not significantly different between two groups. Multivariate analysis revealed that extra-cardiac shunt group has a smaller total infarct volume (odds ratio [OR]=0.427, 95% confidence interval [95% CI] 0.228-0.799, p=0.008), and significantly higher bubble grade during resting state and lower grade during the Valsalva maneuver (OR= 0.539, 95% CI 0.438-0.663, p<0.001). Stroke related to an extra-cardiac shunt presented smaller infarct volume, favorable clinical outcomes and characteristic finding on TEE with agitated saline contrast. Further study is needed to confirm whether the extra-cardiac shunt is an independent risk factor. PMID:27653885

  8. 21 CFR 882.5550 - Central nervous system fluid shunt and components.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Central nervous system fluid shunt and components. 882.5550 Section 882.5550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... shunt is a device or combination of devices used to divert fluid from the brain or other part of...

  9. 21 CFR 882.5550 - Central nervous system fluid shunt and components.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Central nervous system fluid shunt and components. 882.5550 Section 882.5550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... shunt is a device or combination of devices used to divert fluid from the brain or other part of...

  10. Sound absorption of a finite micro-perforated panel backed by a shunted loudspeaker.

    PubMed

    Tao, Jiancheng; Jing, Ruixiang; Qiu, Xiaojun

    2014-01-01

    Deep back cavities are usually required for micro-perforated panel (MPP) constructions to achieve good low frequency absorption. To overcome the problem, a close-box loudspeaker with a shunted circuit is proposed to substitute the back wall of the cavity of the MPP constructions to constitute a composite absorber. Based on the equivalent circuit model, the acoustic impedance of the shunted loudspeaker is formulated first, then a prediction model of the sound absorption of the MPP backed by shunted loudspeaker is developed by employing the mode solution of a finite size MPP coupled by an air cavity with an impendence back wall. The MPP absorbs mid to high frequency sound, and with properly adjusted electrical parameters of its shunted circuit, the shunted loudspeaker absorbs low frequency sound, so the composite absorber provides a compact solution to broadband sound control. Numerical simulations and experiments are carried out to validate the model.

  11. An Unusual Complication of Ventriculoperitoneal Shunt: Urinary Bladder Stone Case Report and Literature Review

    PubMed Central

    Xu, Songtao; Sheng, Weixin; Qiu, Yufa; Wang, Jianguo

    2016-01-01

    Introduction: Ventriculoperitoneal (V-P) shunt surgery is the most common technique used for the treatment of hydrocephalus. The migration of ventriculoperitoneal shunt to the bladder is rare. Only two cases have been previously reported in the literature. Case Presentation: We report on a 38-year-old male who had hydrocephalus and V-P shunt for 12 years. Two years ago, he found himself with recurrent urinary tract infections, haematuria and urges incontinence, and then he was diagnosed with bladder perforation and merge stones. The patient had an abdominal operation to cut off and take out the shunt catheter, as well as a transurethral holmium laser lithotripsy. Conclusions: Bladder perforation and stones are rare examples of complications in V-P surgical procedures. Controlling the effective length of the terminal V-P shunt and modifying it appropriately can effectively reduce these complications. PMID:26889393

  12. Multiple Liver Abscesses Associated with Ventriculoperitoneal Shunt Infection: Case Report and Review of the Literature

    PubMed Central

    Yang, Tae Ki

    2013-01-01

    Liver abscess following ventriculoperitoneal (VP) shunting occurs very rarely. We report an unusual case of multiple liver abscesses caused by Staphylococcus capitis in a 50-year-old compromised woman due to a complicating VP shunt infection. We reviewed the nine cases of VP shunt complications reported in the English literature, and speculated that the most likely pathogenetic mechanism in our case is an infected peritoneal tip that migrated to and penetrated the liver, which subsequently caused the formation of multiple liver abscesses. The patient was successfully treated with percutaneous aspiration, drainage of the abscesses, intravenous antibiotics, and shunt revision. Awareness and vigilance of the possibility of liver abscess formation caused by VP shunt infection will help establish an early accurate diagnosis and therapeutic strategy. PMID:24379956

  13. Instantiating a mechatronic valve schedule for a hydrocephalus shunt.

    PubMed

    Momani, Lina; Alkharabsheh, Abdel Rahman; Al-Zuibi, Nayel; Al-Nuaimy, Waleed

    2009-01-01

    Hydrocephalus is caused by blockage or reabsorption difficulty that upsets the natural balance of production and absorption of cerebrospinal fluid in the brain, resulting in a build-up of the fluid in the ventricles of the brain. One of the recent advances in the treatment of hydrocephalus is the invention of a mechatronic valve. The desirability of such valve lies in the potential of having shunt that not only control hydrocephalus but also seeks to treat it. In contrast to current valves, such a valve is regulated based on a time based schedule not on the differential pressure across the valve. Thus the effectiveness of such valve is highly dependant on selecting an appropriate valve schedule that delivers personal dynamic treatment for every individual patient. Providing such a schedule is likely to be one of the obstacles facing the implementation of the mechatronic valve. In this paper, an algorithm is proposed to help in developing such a schedule that dynamically change based on the patients' own intracranial pressure data and a novel figure of merit, thus providing the physician with an easy tool that facilitate the use of the mechatronic valve. The algorithm was implemented in M ATLAB and Simulink. Real ICP data for three hydrocephalus patients (before shunting) were used to test this algorithm and the resulted schedules along with the resulted intracranial pressure data have illustrated the effectiveness of the algorithm in providing schedule that maintain ICP within the normal limits. PMID:19963474

  14. Fabrication and characterization of shunted μ-SQUID

    SciTech Connect

    Kumar, Nikhil; Fournier, T.; Courtois, H.; Gupta, Anjan K.

    2014-04-24

    In order to eliminate hysteresis, we have fabricated and characterized niobium based shunted micron size superconducting quantum interference devices (μ-SQUIDs). We find a wide temperature range where these μ-SQUIDs are non-hysteretic in nature and show a very good I{sub c} vs. B oscillations in hysteretic regime and V vs. B oscillations in non-hysteretic regime. Here we report the characteristics of a shunted- μ-SQUID (Wf38LS72D5). In this device we have achieved a large voltage modulation, in non-hysteretic regime, at various temperatures including such as 1.1 mV at 6.62 K with a transfer function V{sub Φ} = 7.2mV/Φ{sub 0}. The figures within the original article PDF file, as supplied to AIP Publishing, were affected by a PDF-processing error. Consequently, the article re-flowed and pagination increased from 3 to 4 pages. This article was updated on 14 May 2014 to correct the PDF-processing error, with the scientific content remaining unchanged. Readers are advised that the replacement article PDF file contains an additional blank page to preserve the original pagination.

  15. Fabrication and characterization of shunted μ-SQUID

    NASA Astrophysics Data System (ADS)

    Kumar, Nikhil; Fournier, T.; Courtois, H.; Gupta, Anjan K.

    2014-04-01

    In order to eliminate hysteresis, we have fabricated and characterized niobium based shunted micron size superconducting quantum interference devices (μ-SQUIDs). We find a wide temperature range where these μ-SQUIDs are non-hysteretic in nature and show a very good Ic vs. B oscillations in hysteretic regime and V vs. B oscillations in non-hysteretic regime. Here we report the characteristics of a shunted- μ-SQUID (Wf38LS72D5). In this device we have achieved a large voltage modulation, in non-hysteretic regime, at various temperatures including such as 1.1 mV at 6.62 K with a transfer function VΦ = 7.2mV/Φ0. The figures within the original article PDF file, as supplied to AIP Publishing, were affected by a PDF-processing error. Consequently, the article re-flowed and pagination increased from 3 to 4 pages. This article was updated on 14 May 2014 to correct the PDF-processing error, with the scientific content remaining unchanged. Readers are advised that the replacement article PDF file contains an additional blank page to preserve the original pagination.

  16. Transjugular Intrahepatic Portosystemic Shunt (TIPS): Current Status and Future Possibilities

    SciTech Connect

    Bilbao, Jose Ignacio; Quiroga, Jorge; Herrero, Jose Ignacio; Benito, Alberto

    2002-08-15

    Since the insertion of the first TIPS in 1989 much has been learned about this therapeutic procedure. It has an established role for the treatment of some complications of portal hypertension: prevention of recurrent variceal bleeding and rescue of patients with acute uncontrollable variceal bleeding. In addition TIPS is useful for Budd-Chiari syndrome, refractory ascites and hepatorenal syndrome, although its specific role in these indications remains to be definitively established. However, the decrease in sinusoidal blood flow induced by TIPS can lead to the patient developing hepatic encephalopathy and liver failure in some cases. Therefore, TIPS should be used with caution in patients with very poor liver function. From a technical point of view, successful placement of TIPS is achieved in more than 98% of cases by experienced groups. At present, evaluation of TIPS dysfunction based on morphology probably leads to an overdiagnosis of this complication since most of these cases are not associated with clinical manifestations (recurrent bleeding or refractory ascites). The major disadvantage of TIPS remains its poor long-term patency requiring a mandatory surveillance program. The indicator for shunt function/malfunction should be the portosystemic pressure gradient, which is best assessed by intravascular measurements. Shunt obstructions may be prevented or reduced by the use of stent-grafts in the future.

  17. Transjugular Intrahepatic Portosystemic Shunts in Children with Biliary Atresia

    SciTech Connect

    Huppert, Peter E.; Goffette, Pierre; Sokal, Emil M.; Schweizer, Paul; Claussen, Claus D.

    2002-12-15

    Purpose: We retrospectively evaluated the technical and long-term clinical results of transjugularintrahepatic portosystemic shunts (TIPS) in children with portal hypertension and biliary atresia (BA). Methods: Nine children with BA and recurrent bleeding from esophagogastric and/or intestinal varices were treated by TIPS at the age of 34-156 months and followed-up in two centers. Different types of stents were used. Results: Shunt insertion succeeded in all patients, but in two a second procedure was necessary. Seven procedures lasted more than 3 hr, mainly due to difficult portal vein puncture.Variceal bleeding ceased in all patients; however, 16 reinterventions were performed in eight patients for clinical reasons (n =11) and sonographically suspected restenosis (n =5). Four patients underwent successful liver transplantation 4-51 months after TIPS and five are in good clinical conditions 64-75 months after TIPS. Conclusions: TIPS in children with BA is technically difficult, mainly due to periportal fibrosis and small portal veins. Frequency of reinterventions seems to be higher compared with adults.

  18. Isolation and characterization of Salmonella typhimurium glyoxylate shunt mutants.

    PubMed Central

    Wilson, R B; Maloy, S R

    1987-01-01

    Growth of Salmonella typhimurium on acetate as a sole carbon source requires expression of the glyoxylate shunt; however, the genes for the glyoxylate shunt enzymes have not been previously identified in S. typhimurium. In this study, we isolated transposon insertions in the genes for the two unique enzymes of this pathway, aceA (isocitrate lyase) and aceB (malate synthase). The aceA and aceB genes were located at 89.5 min on the S. typhimurium genetic map. Genetic linkage to nearby loci indicated that the relative gene order is purDJ metA aceB aceA. Transposon insertions in aceB were polar on aceA, suggesting that the genes form an operon transcribed from aceB to aceA. Transcriptional regulation of the aceBA operon was studied by constructing mini-Mu d(lac Kan) operon fusions. Analysis of these fusions indicated that expression of the aceBA operon is regulated at the level of transcription; the aceBA genes were induced when acetate was present and repressing carbon sources were absent. Although glucose represses expression of the aceBA operon, repression does not seem to be mediated solely by cyclic AMP-cyclic AMP receptor protein complex. Mutants with altered regulation of the aceBA operon were isolated. PMID:3298210

  19. Nonvascular needle and shunt placements for fetal therapy.

    PubMed Central

    Holzgreve, W; Evans, M I

    1993-01-01

    The nonvascular placement of needles and shunts for the in utero treatment of fetuses with fluid-filled, space-occupying anomalies has been done for about 10 years. The rationale for this approach is to attempt to prevent progressive impairment of organ function or lethal damage by early decompression. Experience has taught us that the key to success in these cases is the exclusion of associated anomalies and the use of appropriate tests to assess the residual organ function at the time of first diagnosis. In fetuses with hydrothorax, shunts can prevent pulmonary hypoplasia, and in those with obstructive uropathy, they can prevent the development of progressive lung hypoplasia and renal damage before a fetus is fully viable. In fetuses with ovarian cysts, prenatal puncture is occasionally indicated, but in those with hydrocephalus, the beneficial effect of prenatal drainage is more controversial. The catheters used for in utero placement have been improved and carry a smaller risk than open fetal surgical procedures. Images PMID:8236975

  20. Laparoscopic Cholecystectomy for Acute Calcular Cholecystitis in a Patient with Ventriculoperitoneal Shunt: A Case Report and Literature Review

    PubMed Central

    Albarrak, Abdullah A.; Khairy, Sami; Ahmed, Alzahrani Mohammed

    2015-01-01

    Management of patients who have ventriculoperitoneal shunt presenting with acute calcular cholecystitis has remained a clinical challenge. In this paper, the hospital course and the follow-up of a patient presenting with acute calcular cholecystitis and ventriculoperitoneal shunt managed with laparoscopic cholecystectomy are presented followed by literature review on the management of acute calcular cholecystitis in patients who have ventriculoperitoneal shunts. PMID:26798543

  1. Hepatic Arterial Infusion Chemotherapy Combined with Venous Embolization in a Patient with Hepatic Metastases with an Arteriovenous Shunt

    SciTech Connect

    Nishiofuku, Hideyuki; Tanaka, Toshihiro; Sakaguchi, Hiroshi; Yamamoto, Kiyosei; Inoue, Masayoshi; Sueyoshi, Satoru; Shinnkai, Takayuki; Hasegawa, Masatoshi; Kichikawa, Kimihiko

    2009-07-15

    We describe herein a patient who had hepatic metastases with an arteriovenous shunt and was treated by hepatic arterial infusion chemotherapy. The arteriovenous shunt was diagnosed by {sup 99m}Tc-macroaggregated albumin scintigraphy and hepatic venous embolization was performed to reduce shunt flow.

  2. Relationship of the location of the ventricular catheter tip and function of the ventriculoperitoneal shunt.

    PubMed

    Yamada, Shoko Merrit; Kitagawa, Ryo; Teramoto, Akira

    2013-01-01

    The long-term maintenance of ventriculoperitoneal (VP) shunt function depends on the correct placement of the catheter tip in the lateral ventricle. The relationship between the location of the ventricular catheter tip and VP shunt function was analyzed in 52 patients. The location of the ventricular catheter tip was classified into one of the following five groups: (i) Group A--superior to the foramen of Monro; (ii) Group B--in the center of the lateral ventricle body; (iii) Group C--in the third ventricle; (iv) Group D--contacting the ventricle wall; and (v) Group E--in the septum pellucidum. VP shunt function was defined as well controlled hydrocephalus when the Evan's ratio of the ventricular size was < 0.3. The VP shunt functioned well in 14 of 52 patients (26.9%), the shunt valve pressure was incorrectly set in 21 (40.4%), and irreversible shunt malfunction was identified in 17 (32.7%). Among the 14 patients with a well-functioning shunt, 13 were in Groups A or B with an odds ratio (OR) of 17.875 (p<0.05). In the 17 irreversible shunt malfunctions, 13 were identified in Groups C, D, or E with an OR of 0.123 (p<0.05). Long term VP shunt function or failure due to irreversible malfunction is directly influenced by the position of the ventricular catheter tip. Ideal points for positioning the ventricular catheter tip are superior to the foramen of Monro and in the center of the lateral ventricle body. Early shunt revision may be required for patients in whom the catheter tip contacts the ventricle wall or is located in the septum pellucidum.

  3. Choice of valve type and poor ventricular catheter placement: Modifiable factors associated with ventriculoperitoneal shunt failure.

    PubMed

    Jeremiah, Kealeboga Josephine; Cherry, Catherine Louise; Wan, Kai Rui; Toy, Jennifer Ah; Wolfe, Rory; Danks, Robert Andrew

    2016-05-01

    Ventriculoperitoneal (VP) shunt insertion is a common neurosurgical procedure, essentially unchanged in recent years, with high revision rates. We aimed to identify potentially modifiable associations with shunt failure. One hundred and forty patients who underwent insertion of a VP shunt from 2005-2009 were followed for 5-9years. Age at shunt insertion ranged from 0 to 91years (median 44, 26% <18years). The main causes of hydrocephalus were congenital (26%), tumour-related (25%), post-haemorrhagic (24%) or normal pressure hydrocephalus (19%). Fifty-eight (42%) patients required ⩾1 shunt revision. Of these, 50 (88%) were for proximal catheter blockage. The median time to first revision was 108days. Early post-operative CT scans were available in 105 patients. Using a formal grading system, catheter placement was considered excellent in 49 (47%) but poor (extraventricular) in 13 (12%). On univariate analysis, younger age, poor ventricular catheter placement and use of a non-programmable valve were associated with shunt failure. On logistic regression modelling, the independent associations with VP shunt failure were poor catheter placement (odds ratio [OR] 4.9, 95% confidence interval [CI] 1.3-18.9, p=0.02) and use of a non-programmable valve (OR 0.4, 95% CI 0.2-1.0, p=0.04). In conclusion, poor catheter placement (revision rate 77%) was found to be the strongest predictor of shunt failure, with no difference in revisions between excellent (43%) and moderate (43%) catheter placement. Avoiding poor placement in those with mild or moderate ventriculomegaly may best reduce VP shunt failures. There may also be an influence of valve choice on VP shunt survival.

  4. Applied methods to verify LP turbine performance after retrofit

    SciTech Connect

    Overby, R.; Lindberg, G.

    1996-12-31

    With increasing operational hours of power plants, many utilities may find it necessary to replace turbine components, i.e., low pressure turbines. In order to decide between different technical and economic solutions, the utility often takes the opportunity to choose between an OEM or non-OEM supplier. This paper will deal with the retrofitting of LP turbines. Depending on the scope of supply the contract must define the amount of improvement and specifically how to verify this improvement. Unfortunately, today`s Test Codes, such as ASME PTC 6 and 6.1, do not satisfactorily cover these cases. The methods used by Florida Power and Light (FP and L) and its supplier to verify the improvement of the low pressure turbine retrofit at the Martin No. 1 and Sanford No. 4 units will be discussed and the experience gained will be presented. In particular the influence of the thermal cycle on the applicability of the available methods will be analyzed and recommendations given.

  5. The Lp regularity problem for the Stokes system on Lipschitz domains

    NASA Astrophysics Data System (ADS)

    Geng, Jun; Kilty, Joel

    2015-08-01

    We study the Lp regularity problem for the stationary Stokes system on Lipschitz domains. For any p > 2 we show that a weak reverse Hölder inequality with exponent p is both necessary and sufficient for the solvability of the regularity problem with data in W 1, p (∂ Ω) ∩ Lnp (∂ Ω). We also obtain the W 1, p (Ω) estimate ‖ ∇u ‖ Lp (Ω) +‖ q ‖ Lp (Ω) ≤‖ f ‖ Lp (Ω) in a bounded Lipschitz domain Ω ⊂Rd for solutions to the Dirichlet problem Δu = ∇q + div (f), div (u) = 0 in Ω and u = 0 on ∂Ω, where |1/p -1/2 | < 1/2d + ε.

  6. 6. ROOF OF TURBINE BUILDING AND OF L.P. BOILER ROOM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. ROOF OF TURBINE BUILDING AND OF L.P. BOILER ROOM FROM NORTH END OF TURBINE BUILDING ROOF - Portland General Electric Company, Turbine Building, 1841 Southeast Water Street, Portland, Multnomah County, OR

  7. 76 FR 11446 - Erie Boulevard Hydropower, LP; Notice of Application Accepted for Filing, Soliciting Motions to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Erie Boulevard Hydropower, LP; Notice of Application Accepted for Filing..., Recommendations, Terms and Conditions, and Fishway Prescriptions Take notice that the following...

  8. [Physiological variations of LpA1, HDL2 and principal lipid markers in athletes].

    PubMed

    Choukaifé, A; Fradin, S; Bureau, F; Sesboüe, B; Arhan, P; Drosdowsky, M A

    1994-01-01

    An original approach of the influence of physical activities on lipid metabolism is presented in this work: the authors studied the physiological variations of the lipoparticle LpA1, high-density lipoprotein subfraction HDL2 and the most important lipid markers in serum of a presumably healthy population of 55 high-level sportsmen. They were 18-45 years old and practised endurance sports, whether individual (cycling, long-distance running), or collective activities (soccer, basketball). The authors observed an important increase of LpA1 (+20%, p < 0.001) and C-HDL2 (+23.3%, p < 0.01) after an intense physical activity (CK = 430 +/- 312 U/l); they also found a good correlation between LpA1 and HDL2 (r = 0.85, p < 0.0001) and between LpA1 and CK (r = 0.62, p < 0.001).

  9. Global Measurement of Junge Layer Stratospheric Aerosol with OMPS/LP. Scattering Properties and Particle Size

    NASA Astrophysics Data System (ADS)

    Rault, D. F.; Bhartia, P. K.

    2014-12-01

    The OMPS/LP was launched on board the NPP space platform in October 2011. Over the past two years, the OMPS/LP was used to retrieve the global distribution of ozone and aerosol. The paper will describe the aerosol product, which NASA is presently preparing for public release. The current OMPS/LP aerosol product consists of latitude-altitude curtains along the NPP Sun-synchronous orbit, from cloud top to about 40 km. These curtains extend from local sunrise in Southern polar region to local sunset in Northern polar region. Aerosol extinctions are produced at five distinct wavelengths, namely 513, 525, 670, 750 and 870 nm, with a sampling of 1 km in vertical direction and 1 degree latitude in the along-track direction. The OMPS/LP aerosol dataset is fairly large, with 7000 vertical profiles produced each day for each wavelength. The aerosol product will be presented in terms of extinction monthly median values and mean Angstrom coefficient (particle size). Over the past two years, the Junge layer was affected by several events such as volcanic eruptions (Nabro and Kelut) and a meteor (Chelyabinsk), the effects of which are clearly visible in the OMPS/LP dataset. The Asian Tropopause Aerosol Layer (ATAL) can also be observed in the OMPS/LP dataset. Moreover the effect of the Brewer Dobson Circulation (BDC) can be observed at high altitudes: the BDC velocity at 35 km can be estimated from the time variation of iso-density heights and was found to compare well with BDC velocities evaluated with the water vapor tape recorder technique as well as MERRA model values. Finally, aerosol filaments are clearly visible in OMPS/LP aerosol dataset as they appear as distinct "bubbles" on the OMPS/LP curtain files at periodic intervals in both the Southern and Northern hemispheres. These filaments are a main source of transport from tropical to polar region, and OMPS/LP data can therefore be instrumental in quantifying the rate of this transport. The quality of the OMPS/LP aerosol

  10. [Lp-PLA2, a biomarker of vascular inflammation and vulnerability of atherosclerosis plaques].

    PubMed

    Bonnefont-Rousselot, D

    2016-05-01

    A chronic inflammation is involved in various stages of development of the atherosclerotic plaques. Among the emerging biomarkers of atherogenesis, the lipoprotein-associated phospholipase A2 (Lp-PLA2), formerly known as PAF-acetylhydrolase (McIntyre et al., 2009), hydrolyses the oxidized short chain phospholipids of low-density lipoproteins (LDL), thereby releasing pro-inflammatory mediators (lysophospholipids and oxidized fatty acids). Lp-PLA2, produced by monocytes/macrophages and T-lymphocytes, and mainly associated with LDL (Gazi et al., 2005), is predominantly expressed in the necrotic center of the atherosclerotic plaques and in the macrophage-rich areas (Kolodgie et al., 2006). It would have a predictive role of cardiovascular (CV) events in relation to the vulnerability of atherosclerotic plaques. Determination of Lp-PLA2 has been proposed in the assessment of the CV risk, to ensure a better stratification of populations at intermediate risk for targeted therapy (Davidson et al., 2008). Its proatherogenic role suggested that inhibition of its activity could ensure a better vascular protection in combination with cholesterol-lowering agents. Nevertheless, Lp-PLA2 is not yet a fully validated marker for use in daily clinical practice, especially since the studies using an inhibitor of Lp-PLA2 (darapladib) (STABILITY Investigators et al., 2014; O'Donoghue et al., 2014) did not show any reduction in coronary events. Lp-PLA2 could have a site-specific role in plaque inflammation and development (Fenning et al., 2015). High Lp-PLA2 activity could reflect a response to pro-inflammatory stress characteristic of atherosclerosis (Marathe et al., 2014). This presentation aims at clarifying the involvement of Lp-PLA2 in the pathophysiology of atherosclerosis, and at assessing its interest both as a biomarker for the onset of CV events and as a therapeutic target. PMID:26499399

  11. High-resolution linkage map in the vicinity of the Lp locus

    SciTech Connect

    Mullick, A.; Gros, P.; Trasler, D.

    1995-04-10

    Looptail (Lp) is a mutation that profoundly affects neurulation in mouse and is characterized by craniorachischisis, an open neural tube extending from the midbrain to the tail in embryos homozygous for the mutation. Lp maps to the distal portion of mouse chromosome 1, and as part of a positional cloning approach, we have generated a high-resolution linkage map of the Lp chromosomal region. For this, we have carried out extensive segregation analysis in a total of 706 backcross mice informative for Lp and derived from two crosses, (Lp/ + X SJL/J)F1 X SJL/J and (Lp/ + X SWR/J)F1 X SWR/J. In addition, 269 mice from a (Mus spretus X C57BL/6J)F1 X C57BL/6J interspecific backcross were also used to order marker loci and calculate intergene distances for this region. With these mice, a total of 28 DNA markers corresponding to either cloned genes or anonymous markers of the SSLP or SSCP-types were mapped within a 5-cM interval overlapping the Lp region, with the following locus order and interlocus distances (in cM): centromere-D1Mit110 / Atp1{beta}1 / Cd3{zeta} /Cd3{eta} / D1Mit145 - D1Hun14 /D1Mit15 - D1Mit111 / D1Mit112 - D1Mit114 - D1Mit148 / D1Mit205/ D1Mit36 / D1Mit146 / D1Mit147 / D1Mit149 / Spnal1/Fcer1{alpha}-Eph1-Hlx1/D1Mit62. These studies have allowed the delineation of a maximum genetic interval for Lp of 0.5 cM, a size amenable to physical mapping techniques. 58 refs., 4 figs., 2 tabs.

  12. Analysis of the Suitability of OMPS LP Ozone Profile Dataset for Extending the Aura MLS Record

    NASA Astrophysics Data System (ADS)

    Kramarova, N. A.; Bhartia, P. K.; Stolarski, R. S.; DeLand, M. T.

    2014-12-01

    The new Ozone Mapping and Profiler Suite (OMPS), launched on 28 October 2011 on the Suomi National Polar-orbiting Partnership satellite, represents the next generation of the US ozone monitoring system. The OMPS Limb Profiler (LP) sensor measures solar radiances scattered from the atmospheric limb in the UV and visible spectral ranges and reconstruct the vertical ozone profiles from the cloud top up to 60 km. The regular LP observations started in early 2012, and now the LP data record exceeds 2.5 years. In this presentation we will demonstrate capability of the new LP sensor to characterize the vertical ozone distribution in different atmospheric regions that are most sensitive to the changes in the stratospheric composition and dynamics. We will consider: a) the seasonal ozone patterns in the lower stratosphere - upper troposphere; b) the vertical ozone distribution inside the Antarctic ozone hole; c) the ozone patterns forced by the Quasi-Biennial Oscillations in the lower tropical stratosphere. The main focus of this study is to perform a comprehensive analysis of ozone patterns obtained from OMPS LP with those observed by Aura MLS to isolate similarities and differences between two sensors in characterizing these processes. We will examine how well LP reproduces the named above natural signals in comparison with MLS in terms of amplitude, phase and vertical structure. One of the key issues is that two instruments measure ozone in different coordinate systems: the LP measures ozone profiles as number density on a regular altitude scale, while Aura MLS retrieves ozone profiles as mixing ratios on pressure vertical grids. The comparison of two measurements requires unit conversion that in turn involves temperature profiles. Thus, the uncertainties related to the unit conversion should be accounted during the analysis. This scientific validation is critical for the further LP algorithm improvement and continuation of the Aura MLS ozone record in the future.

  13. Trans-anal protrusion of ventriculo-peritoneal shunt catheter with silent bowel perforation: report of ten cases in children.

    PubMed

    Ghritlaharey, Rajendra Kumar; Budhwani, K S; Shrivastava, Dhirendra K; Gupta, Gaurav; Kushwaha, Anand Singh; Chanchlani, Roshan; Nanda, Monika

    2007-06-01

    Ventriculo-peritoneal (VP) shunting used in the treatment for hydrocephalus is associated with several complications. Mechanical failure of shunt is the commonest complication of all. Visceral/bowel perforation is an unusual but serious complication of VP shunting. This article reports our experience in the management of ten children who had VP Shunt catheter protrusion from anus. This is a retrospective study of ten patients who had VP shunt catheter protrusion from anus, admitted in the department of paediatric surgery between Jan 1996 and Dec 2005. The records of above ten cases were reviewed for their clinical presentation and management, etc. We had performed 398 VP shunt operations in the last 10 years. Two hundred and seventy one (68.09%) VP Shunts were done for congenital hydrocephalus of which 164 were done in infancy/neonatal period and 107 VP shunts were done in the age group of >1-12 years. One hundred and twenty-seven (31.90%) VP shunt operations were done for patients who had hydrocephalus as a complication following tubercular meningitis (TBM). Out of 398 VP shunts, ten patients (2.51%) had protrusion of the distal end of peritoneal catheter from anus without causing/leading to peritonitis. We observed a 08.29% mortality of all VP shunt operations. Protrusion of VP shunt catheter per rectum can occur without producing peritonitis. Formal exploration and localization of entry of VP shunt catheter in bowel is not mandatory. Mini laparotomy and revision of peritoneal part of shunt can be done if there is no shunt infection.

  14. Amplitude and recurrence time analysis of LP activity at Mount Etna, Italy

    NASA Astrophysics Data System (ADS)

    Cauchie, Léna; Saccorotti, Gilberto; Bean, Christopher J.

    2015-09-01

    The aim of this work is to improve our understanding of the long-period (LP) source mechanism at Mount Etna (Italy) through a statistical analysis of detailed LP catalogues. The behavior of LP activity is compared with the empirical laws governing earthquake recurrence, in order to investigate whether any relationships exist between these two apparently different earthquake classes. We analyzed a family of 8894 events detected during a temporary experiment in August 2005. For that time interval, the LP activity is sustained in time and the volcano did not exhibit any evident sign of unrest. The completeness threshold of the catalogue is established through a detection test based on synthetic waveforms. The retrieved amplitude distribution differs significantly from the Gutenberg-Richter law, and the interevent times distribution does not follow the typical γ law, expected for tectonic activity. In order to compare these results with a catalogue for which the source mechanism is well established, we applied the same procedure to a data set from Stromboli Volcano, where recurrent LP activity is closely related to very-long-period pulses, in turn associated with the summit explosions. Our results indicate that the two catalogues exhibit similar behavior in terms of amplitude and interevent time distributions. This suggests that the Etna's LP signals are most likely driven by stress changes caused by an intermittent degassing process occurring at depth, similar to that which drives the summit explosions at Stromboli Volcano.

  15. Universality of non-Ohmic shunt leakage in thin-film solar cells

    NASA Astrophysics Data System (ADS)

    Dongaonkar, S.; Servaites, J. D.; Ford, G. M.; Loser, S.; Moore, J.; Gelfand, R. M.; Mohseni, H.; Hillhouse, H. W.; Agrawal, R.; Ratner, M. A.; Marks, T. J.; Lundstrom, M. S.; Alam, M. A.

    2010-12-01

    We compare the dark current-voltage (IV) characteristics of three different thin-film solar cell types: hydrogenated amorphous silicon (a-Si:H) p-i-n cells, organic bulk heterojunction (BHJ) cells, and Cu(In,Ga)Se2 (CIGS) cells. All three device types exhibit a significant shunt leakage current at low forward bias (V <˜0.4) and reverse bias, which cannot be explained by the classical solar cell diode model. This parasitic shunt current exhibits non-Ohmic behavior, as opposed to the traditional constant shunt resistance model for photovoltaics. We show here that this shunt leakage (Ish), across all three solar cell types considered, is characterized by the following common phenomenological features: (a) voltage symmetry about V =0, (b) nonlinear (power law) voltage dependence, and (c) extremely weak temperature dependence. Based on this analysis, we provide a simple method of subtracting this shunt current component from the measured data and discuss its implications on dark IV parameter extraction. We propose a space charge limited (SCL) current model for capturing all these features of the shunt leakage in a consistent framework and discuss possible physical origin of the parasitic paths responsible for this shunt current mechanism.

  16. Portasystemic shunting versus liver transplantation for the Budd-Chiari syndrome.

    PubMed Central

    Bismuth, H; Sherlock, D J

    1991-01-01

    Over 12 years, 22 patients with the Budd-Chiari syndrome were treated surgically. Eighteen underwent a mesenterico-caval shunt (MCS); two, a side-to-side portacaval shunt; one, a mesenterico-atrial shunt (MAS); and one, a liver transplantation (OLT). One patient died after operation from the precipitating condition, and two MCS grafts that thrombosed were restored. All 21 surviving patients remain well, free from ascites, and all shunts are patent after a mean follow-up of 5.6 +/- 1 years, five patients with more than 10 years' follow-up. This long-term survival achieved by portasystemic shunts suggests that they have a major role in the treatment of the Budd-Chiari syndrome. The authors prefer the mesenterico-caval shunt using a jugular graft. This ensures a total portasystemic shunt, avoids subhepatic surgery, and reduces the long-term risk of prosthetic graft thrombosis. The MAS was reserved for cases with complete caval thrombosis. Patients with significant degrees of caval compression were satisfactorily decompressed by MCS. In patients not promptly treated, the disease progresses to cirrhosis, and such patients must be evaluated for transplantation similarly to those with other hepatopathies. Images Fig. 1. Fig. 3. Fig. 4. Fig. 5A and B. PMID:1953111

  17. Ventriculosternal Shunting for the Management of Hydrocephalus: Case Report of A Novel Technique

    PubMed Central

    Hung Pang, Peter Ka; Chan, Kwong Yau; Ching Kwok, John Kwong

    2015-01-01

    BACKGROUND: Conventional cerebrospinal fluid diversion such as ventriculoperitoneal or ventriculoatrial shunting for the management of hydrocephalus is one of the commonest neurosurgical procedures. However, in selected patients, surgical options are limited when relative contraindications for these operations exist. A patient who underwent ventriculosternal shunting, a novel procedure, is presented with durable and successful outcomes. OBJECTIVE: To demonstrate the feasibility, durability, and safety of ventriculosternal shunting for the management of hydrocephalus. METHODS: A patient with end-stage renal failure and heart failure with recurrent pleural effusion suffered from post–subarachnoid hemorrhage communicating hydrocephalus. Because of the need for continuous ambulatory peritoneal dialysis and the risk of introducing excessive cardiac preloading, conventional shunting was relatively contraindicated. Ventriculosternal shunting was performed by adopting the cancellous matrix of the sternum as the anatomic receptacle for intraosseous cerebrospinal fluid absorption. After placement of the ventricular catheter in the usual manner, the distal end was inserted into the sternum. RESULTS: There was demonstrable clinical and radiological improvement in hydrocephalus by ventriculosternal shunting. Cerebrospinal fluid intraosseous absorption by this novel procedure translated into both physical and cognitive recovery. The procedure was tolerable, effective, and durable, with the patient suffering no complications 3 years after the procedure. CONCLUSION: Ventriculosternal shunting for the management of hydrocephalus is a feasible, safe, and durable surgical treatment option for selected patients when conventional procedures are contraindicated. ABBREVIATION: VS, ventriculosternal PMID:26114598

  18. Universality of Non-Ohmic Shunt Leakage in Thin-Film Solar Cells

    SciTech Connect

    Dongaonkar, S.; Servaites, J.D.; Ford, G.M.; Loser, Stephen; Moore, J.; Gelfand, R.M.; Mohseni, H.W.; Agrawal, R.; Ratner, Mark A.; Marks, Tobin J.; Lundstrom, M.S.; Alam, M.A.

    2010-01-01

    We compare the dark current-voltage (IV) characteristics of three different thin-film solar cell types: hydrogenated amorphous silicon (a-Si:H) p-i-n cells, organic bulk heterojunction (BHJ) cells, and Cu(In,Ga)Se2 (CIGS) cells. All three device types exhibit a significant shunt leakage current at low forward bias (V<~0.4) and reverse bias, which cannot be explained by the classical solar cell diode model. This parasitic shunt current exhibits non-Ohmic behavior, as opposed to the traditional constant shunt resistance model for photovoltaics. We show here that this shunt leakage (Ish) , across all three solar cell types considered, is characterized by the following common phenomenological features: (a) voltage symmetry about V=0 , (b) nonlinear (power law) voltage dependence, and (c) extremely weak temperature dependence. Based on this analysis, we provide a simple method of subtracting this shunt current component from the measured data and discuss its implications on dark IV parameter extraction. We propose a space charge limited (SCL) current model for capturing all these features of the shunt leakage in a consistent framework and discuss possible physical origin of the parasitic paths responsible for this shunt current mechanism.

  19. Flexural wave band-gaps in phononic metamaterial beam with hybrid shunting circuits

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Wen, Ji-Hong; Chen, Sheng-Bing; Wang, Gang; Wen, Xi-Sen

    2015-03-01

    Periodic arrays of hybrid-shunted piezoelectric patches are used to control the band-gaps of phononic metamaterial beams. Passive resistive-inductive (RL) shunting circuits can produce a narrow resonant band-gap (RG), and active negative capacitive (NC) shunting circuits can broaden the Bragg band-gaps (BGs). In this article, active NC shunting circuits and passive resonant RL shunting circuits are connected to the same piezoelectric patches in parallel, which are usually called hybrid shunting circuits, to control the location and the extent of the band-gaps. A super-wide coupled band-gap is generated when the coupling between RG and the BG occurs. The attenuation constant of the infinite periodic structure is predicted by the transfer matrix method, which is compared with the vibration transmittance of a finite periodic structure calculated by the finite element method. Numerical results show that the hybrid-shunting circuits can make the band-gaps wider by appropriately selecting the inductances, negative capacitances, and resistances. Project supported by the National Natural Science Foundation of China (Grant Nos. 51275519 and 51175501).

  20. Shunt Diode Designs in Li/cf Shuttle Batteries

    NASA Technical Reports Server (NTRS)

    Miller, D.; Higgins, R.

    1984-01-01

    Although Li/CF cells and batteries have an excellent safety record, they are included with other battery systems that require additional safety precautions. One precaution suggested is the inclusion of shunt diodes into these batteries. The benefits of this addition are examined. All cells tested at elevated temperatures vent regardless of length of time between being fully discharged and reversed or inclusion of the diode in the system. Cells discharged at ambient temperatures all show a relatively quick reversal, but stabilize at voltages that are high enough that the diodes are not functioning. Cells tested at depressed temperatures reverse the deepest of all cells tested, with the deepest reversal occurring very early in the test and voltages recovering to above -0.60 volts near the end of the tests. Anode limited cells will eliminate the venting during hot reversal.

  1. Electro-clinical follow-up of shunted hydrocephalic children.

    PubMed

    Varfis, G; Berney, J; Beaumanoir, A

    1977-01-01

    In a survey of 29 hydrocephalic children treated by ventriculoatrial shunt (Holter valve) with a follow-up of 4 years, EEG records before the operation and at least once a year thereafter, the authors can support the view that an epileptogenic focus has developed around the place of insertion of the ventricular catheter in 19 cases, leading to epileptic seizures in 17 up to now. Thus the incidence of convulsions in this particular group of patients is 0.59 (17/29), the limits of confidence 95% being 0.39-0.76. The irritative abnormalities occur usually during the second year after the operation and the delay for the onset of clinical seizures is variable. The age at operation seems to influence the occurrence of the epileptogenic scar. The type of hydrocephalus and especially the presence of an associated cerebral focal lesion can be of importance in the development of clinical seizures. PMID:405183

  2. Transient Hemolytic Anemia after Transjugular Intrahepatic Portosystemic Stent Shunt

    PubMed Central

    Garcia-Rebollo, Sagrario; Santolaria-Fernández, Francisco; Diaz-Romero, Francisco; Rodriguez-Moreno, Fermin; Martinez-Riera, Antonio

    1996-01-01

    Management of variceal bleeding secondary to portal hypertension constitutes a challenging issue, particularly in child's C cirrhotic patients. Recently, transjugular placement of self-expanding metallic stents in the liver (TIPS), creating a shunt between the portal and hepatic branches has provided a safe and promising therapeutic approach in this clinical situation. We report here the case of a 66-year-old male cirrhotic patient who developed a moderately severe clinical picture of a Coombsnegative hemolytic anemia (serum hemoglobin, 93 g/l, serum bilirubin 160.74 umol/L (9.4 mg/dl), indirect 6.3 mg/dl (107.73 umol/L); serum LDH 1220 u/l, reticulocytes, 5.1%. serum ferritin, 1221 ug/1, schistocytes in peripheral blood smear) the week after undergoing a TIPS, suggesting the development ofa microangiopathic hemolytic anaemia secondary to red blood cell disruption by passing through the metallic network of the stent. PMID:8809588

  3. A thiosulfate shunt in the sulfur cycle of marine sediments.

    PubMed

    Jørgensen, B B

    1990-07-13

    The oxidation of sulfide, generated by bacterial sulfate reduction, is a key process in the biogeochemistry of marine sediments, yet the pathways and oxidants are poorly known. By the use of (35)S-tracer studies of the S cycle in marine and freshwater sediments, a novel shunt function of thiosulfate (S(2)O(3)(2-)) was identified. The S(2)O(3)(2-) constituted 68 to 78 percent of the immediate HS(-)-oxidation products and was concurrently (i) reduced back to HS(-), (ii) oxidized to SO(4)(2-), and (iii) disproportionated to HS(-) + SO(4)(2-). The small thiosulfate pool is thus involved in a dynamic HS(-) - S(2)O(3)(2-) cycle in anoxic sediments. The disproportionation of thiosulfate may help account for the large difference in isotopic composition ((34)S/(32)S) of sulfate and sulfides in sediments and sedimentary rocks.

  4. Staged Transcatheter Treatment of Portal Hypoplasia and Congenital Portosystemic Shunts in Children

    SciTech Connect

    Bruckheimer, Elchanan Dagan, Tamir; Atar, Eli; Schwartz, Michael; Kachko, Ludmila; Superina, Riccardo; Amir, Gabriel; Shapiro, Rivka; Birk, Einat

    2013-12-15

    Purpose: Congenital portosystemic shunts (CPSS) with portal venous hypoplasia cause hyperammonemia. Acute shunt closure results in portal hypertension. A transcatheter method of staged shunt reduction to afford growth of portal vessels followed by shunt closure is reported. Methods: Pressure measurements and angiography in the CPSS or superior mesenteric artery (SMA) during temporary occlusion of the shunt were performed. If vessels were diminutive and the pressure was above 18 mmHg, a staged approach was performed, which included implantation of a tailored reducing stent to reduce shunt diameter by {approx}50 %. Recatheterization was performed approximately 3 months later. If the portal pressure was below 18 mmHg and vessels had developed, the shunt was closed with a device. Results: Six patients (5 boys, 1 girl) with a median age of 3.3 (range 0.5-13) years had CPSS portal venous hypoplasia and hyperammonemia. Five patients underwent staged closure. One patient tolerated acute closure. One patient required surgical shunt banding because a reducing stent could not be positioned. At median follow-up of 3.8 (range 2.2-8.4) years, a total of 21 procedures (20 transcatheter, 1 surgical) were performed. In all patients, the shunt was closed with a significant reduction in portal pressure (27.7 {+-} 11.3 to 10.8 {+-} 1.8 mmHg; p = 0.016), significant growth of the portal vessels (0.8 {+-} 0.5 to 4.0 {+-} 2.4 mm; p = 0.037), and normalization of ammonia levels (202.1 {+-} 53.6 to 65.7 {+-} 9.6 {mu}mol/L; p = 0.002) with no complications. Conclusion: Staged CPSS closure is effective in causing portal vessel growth and treating hyperammonemia.

  5. The effects of dobutamine and dopamine on intrapulmonary shunt and gas exchange in healthy humans

    PubMed Central

    Bryan, Tracey L.; van Diepen, Sean; Bhutani, Mohit; Shanks, Miriam; Welsh, Robert C.

    2012-01-01

    The development of intrapulmonary shunts with increased cardiac output during exercise in healthy humans has been reported in several recent studies, but mechanisms governing their recruitment remain unclear. Dobutamine and dopamine are inotropes commonly used to augment cardiac output; however, both can increase venous admixture/shunt fraction (Qs/Qt). It is possible that, as with exercise, intrapulmonary shunts are recruited with increased cardiac output during dobutamine and/or dopamine infusion that may contribute to the observed increase in Qs/Qt. The purpose of this study was to examine how dobutamine and dopamine affect intrapulmonary shunt and gas exchange. Nine resting healthy subjects received serial infusions of dobutamine and dopamine at incremental doses under normoxic and hyperoxic (inspired O2 fraction = 1.0) conditions. At each step, alveolar-to-arterial Po2 difference (A-aDo2) and Qs/Qt were calculated from arterial blood gas samples, intrapulmonary shunt was evaluated using contrast echocardiography, and cardiac output was calculated by Doppler echocardiography. Both dobutamine and dopamine increased cardiac output and Qs/Qt. Intrapulmonary shunt developed in most subjects with both drugs and paralleled the increase in Qs/Qt. A-aDo2 was unchanged due to a concurrent rise in mixed venous oxygen content. Hyperoxia consistently eliminated intrapulmonary shunt. These findings contribute to our present understanding of the mechanisms governing recruitment of these intrapulmonary shunts as well as their impact on gas exchange. In addition, given the deleterious effect on Qs/Qt and the risk of neurological complications with intrapulmonary shunts, these findings could have important implications for use of dobutamine and dopamine in the clinical setting. PMID:22700799

  6. A single-incision laparoscopic technique for retrieval and replacement of disconnected ventriculoperitoneal shunt tubing found in the peritoneum.

    PubMed

    Jackson, C C; Chwals, W J; Frim, D M

    2002-04-01

    A 7-year-old girl presented with signs and symptoms of increased intracranial pressure 2 years after insertion of a ventriculoperitoneal (VP) shunt. Evaluation revealed disconnection of the distal shunt catheter and migration into the peritoneal cavity. A single-incision laparoscopic procedure was performed to locate and remove the disconnected shunt tubing, and the new shunt catheter was inserted through the laparoscopic port site. Laparoscopy is being used more frequently for evaluation and repair of distal VP shunt malfunctions, but generally still requires multiple incisions for port placement and insertion of the new shunt catheter. The single-incision technique used here is technically feasible, allows excellent visualization of the peritoneal cavity and does not require any incisions beyond the previous one used for initial shunt insertion.

  7. Role of Glyoxylate Shunt in Oxidative Stress Response.

    PubMed

    Ahn, Sungeun; Jung, Jaejoon; Jang, In-Ae; Madsen, Eugene L; Park, Woojun

    2016-05-27

    The glyoxylate shunt (GS) is a two-step metabolic pathway (isocitrate lyase, aceA; and malate synthase, glcB) that serves as an alternative to the tricarboxylic acid cycle. The GS bypasses the carbon dioxide-producing steps of the tricarboxylic acid cycle and is essential for acetate and fatty acid metabolism in bacteria. GS can be up-regulated under conditions of oxidative stress, antibiotic stress, and host infection, which implies that it plays important but poorly explored roles in stress defense and pathogenesis. In many bacterial species, including Pseudomonas aeruginosa, aceA and glcB are not in an operon, unlike in Escherichia coli In P. aeruginosa, we explored relationships between GS genes and growth, transcription profiles, and biofilm formation. Contrary to our expectations, deletion of aceA in P. aeruginosa improved cell growth under conditions of oxidative and antibiotic stress. Transcriptome data suggested that aceA mutants underwent a metabolic shift toward aerobic denitrification; this was supported by additional evidence, including up-regulation of denitrification-related genes, decreased oxygen consumption without lowering ATP yield, increased production of denitrification intermediates (NO and N2O), and increased cyanide resistance. The aceA mutants also produced a thicker exopolysaccharide layer; that is, a phenotype consistent with aerobic denitrification. A bioinformatic survey across known bacterial genomes showed that only microorganisms capable of aerobic metabolism possess the glyoxylate shunt. This trend is consistent with the hypothesis that the GS plays a previously unrecognized role in allowing bacteria to tolerate oxidative stress.

  8. Severity of the ductal shunt: a comparison of different markers

    PubMed Central

    El Hajjar, M; Vaksmann, G; Rakza, T; Kongolo, G; Storme, L

    2005-01-01

    Background: When the ductus arteriosus (DA) is patent, the ductal shunt is proportional to the ratio of left ventricular output (LVO) to systemic blood flow. Systemic blood flow can be estimated by measuring flow in the superior vena cava (SVC). Objective: To re-evaluate the accuracy of standard echocardiographic markers of patent ductus arteriosus (PDA) using LVO/SVC flow ratio. Methods: Prospective study. Preterm infants of 24–30 weeks gestational age and postnatal age less than 48 hours. The following echocardiographic criteria were measured: left atrial to aortic root ratio (LA/Ao); DA diameter by B mode and colour Doppler; mean and end diastolic flow velocity of the left pulmonary artery (LPA); LVO; SVC flow. Results: Twenty three preterm infants were enrolled (median gestational age 28 weeks (range 24–30), median birth weight 840 g (500–1440)). The DA was closed in eight (mean (SD) LVO/SVC 2.4 (0.3)) and open in 15 (mean (SD) LVO/SVC 4.5 (0.6)). An LA/Ao ratio ⩾1.4, a DA diameter ⩾1.4 mm/kg, and a mean and end diastolic flow velocity of LPA respectively ⩾0.42 and ⩾0.20 m/s identified an LVO/SVC ⩾4 with a sensitivity and a specificity above 90%. Conclusion: This study indicates that LA/Ao ratio, DA diameter, and mean and end diastolic flow velocity of the LPA are accurate markers of PDA. These standard echocardiographic variables are easy to measure and need less skill and resources than direct measurements of ductal shunt. PMID:16113155

  9. Role of Glyoxylate Shunt in Oxidative Stress Response.

    PubMed

    Ahn, Sungeun; Jung, Jaejoon; Jang, In-Ae; Madsen, Eugene L; Park, Woojun

    2016-05-27

    The glyoxylate shunt (GS) is a two-step metabolic pathway (isocitrate lyase, aceA; and malate synthase, glcB) that serves as an alternative to the tricarboxylic acid cycle. The GS bypasses the carbon dioxide-producing steps of the tricarboxylic acid cycle and is essential for acetate and fatty acid metabolism in bacteria. GS can be up-regulated under conditions of oxidative stress, antibiotic stress, and host infection, which implies that it plays important but poorly explored roles in stress defense and pathogenesis. In many bacterial species, including Pseudomonas aeruginosa, aceA and glcB are not in an operon, unlike in Escherichia coli In P. aeruginosa, we explored relationships between GS genes and growth, transcription profiles, and biofilm formation. Contrary to our expectations, deletion of aceA in P. aeruginosa improved cell growth under conditions of oxidative and antibiotic stress. Transcriptome data suggested that aceA mutants underwent a metabolic shift toward aerobic denitrification; this was supported by additional evidence, including up-regulation of denitrification-related genes, decreased oxygen consumption without lowering ATP yield, increased production of denitrification intermediates (NO and N2O), and increased cyanide resistance. The aceA mutants also produced a thicker exopolysaccharide layer; that is, a phenotype consistent with aerobic denitrification. A bioinformatic survey across known bacterial genomes showed that only microorganisms capable of aerobic metabolism possess the glyoxylate shunt. This trend is consistent with the hypothesis that the GS plays a previously unrecognized role in allowing bacteria to tolerate oxidative stress. PMID:27036942

  10. Selective 5-HT7 receptor agonists LP 44 and LP 211 elicit an analgesic effect on formalin-induced orofacial pain in mice

    PubMed Central

    DEMİRKAYA, Kadriye; AKGÜN, Özlem Martı; ŞENEL, Buğra; ÖNCEL TORUN, Zeynep; SEYREK, Melik; LACİVİTA, Enza; LEOPOLDO, Marcello; DOĞRUL, Ahmet

    2016-01-01

    ABSTRACT The most recently identified serotonin (5-HT) receptor is the 5-HT7 receptor. The antinociceptive effects of a 5-HT7 receptor agonist have been shown in neuropathic and inflammatory animal models of pain. A recent study demonstrated the functional expression of 5-HT7 receptors in the substantia gelatinosa (SG) of the trigeminal subnucleus caudalis, which receives and processes orofacial nociceptive inputs. Objective To investigate the antinociceptive effects of pharmacological activation of 5-HT7 receptors on orofacial pain in mice. Material and Methods Nociception was evaluated by using an orofacial formalin test in male Balb-C mice. Selective 5-HT7 receptor agonists, LP 44 and LP 211 (1, 5, and 10 mg/kg), were given intraperitoneally 30 min prior to a formalin injection. A bolus of 10 µl of 4% subcutaneous formalin was injected into the upper lip of mice and facial grooming behaviors were monitored. The behavioral responses consisted of two distinct periods, the early phase corresponding to acute pain (Phase I: 0–12 min) and the late phase (Phase II: 12–30 min). Results LP 44 and LP 211 (1, 5, and 10 mg/kg) produced an analgesic effect with reductions in face rubbing time in both Phase I and Phase II of the formalin test. Conclusion Our results suggest that 5-HT7 receptor agonists may be promising analgesic drugs in the treatment of orofacial pain. PMID:27383702

  11. Intractable seizures associated with proximal migration of a ventriculoperitoneal shunt. Case report.

    PubMed

    Yamazaki, Tomoya; Shimizu, Satoru; Sagiuchi, Takao; Iwasaki, Toshiyuki; Utsuki, Satoshi; Suzuki, Sachio; Fujii, Kiyotaka

    2005-11-01

    A 6-year-old girl, who had received a ventriculoperitoneal (VP) shunt using the Codman-Hakim programmable valve system at age 3 months, presented with intractable seizures. Neuroimaging studies showed migration of the proximal part of the system, including the prechamber, into the cranium through the right frontal burr hole. Electroencephalography showed spike-and-wave complexes in the right hemisphere including the site of the migration. The ictus was resolved following revision surgery. The clinical findings suggested the seizures were due to irritation of the brain parenchyma by the migrated system. Proximal migration of a VP shunt may cause both shunt failure and additional focal symptoms.

  12. An interesting case of screen-detected breast cancer encasing a ventriculoperitoneal shunt.

    PubMed

    Jain, Yogesh Kumar; Kokan, Jalal S

    2013-01-01

    A 67-year-old woman was diagnosed with a breast cancer via screening encasing the ventriculoperitoneal shunt. Triple assessment including MRI scan of the breast confirmed the presence of a breast mass and the tubing of the ventriculoperitoneal shunt was running directly through the mass. She underwent wide local excision of the breast cancer as well as rerouting of VP shunt as a joint procedure with the neurosurgery team and recovered uneventfully. This is a very rare and an interesting case and required management involving a different specialty.

  13. Ascites and abdominal pseudocyst: two uncommon ventriculoperitoneal shunt complications in two cases.

    PubMed

    Comba, Atakan; Gülenç, Nazlı; Çaltepe, Gönül; Dağçınar, Adnan; Yüce, Özlem; Kalaycı, Ayhan Gazi; Ulus, Aykan

    2013-01-01

    Ascites and abdominal pseudocysts (APC) are two rare complications that can occur following placement of a ventriculoperitoneal (VP) shunt. Both complications are characterized by abnormal intraperitoneal cerebrospinal fluid (CSF) collections. Although various factors have been implicated, the exact pathogenesis of the two conditions remains elusive. This paper presents two cases of VP shunt placement resulting from hydrocephaly. The first patient presented with generalized ascites and the other with APC, both of whom were six years old. APC and ascites after VP shunt placement are rare and distinct conditions; therefore, they may require different management strategies.

  14. Failure of peritoneal and gallbladder shunts in a child with craniopharyngioma.

    PubMed

    Woodfield, Julie; Magdum, Shailendra

    2013-09-01

    A 1-year-old girl with craniopharyngioma required external drainage of 40-50 mL/h of cerebrospinal fluid (CSF) after biopsy and cyst fenestration. She developed CSF ascites following insertion of a ventriculoperitoneal (VP) shunt and a distended painful gallbladder following ventriculogallbladder shunt insertion. Revision to a ventriculoatrial shunt was required. This is the first time a craniopharyngioma has been reported to cause increased CSF production. The potential mechanisms of CSF overproduction and the difficulties managing the large volume of CSF in a young child are discussed.

  15. Severe Juxtahepatic Venous Injury: Survival after Prolonged Hepatic Vascular Isolation Without Shunting

    PubMed Central

    Worthley, C. S.; Terblanche, J.

    1990-01-01

    Survival following major juxtahepatic venous injury is rare in blunt liver trauma despite the use of intracaval shunting. Prolonged liver arterial inflow control, total hepatic venous isolation and lobectomy without shunting was used in a patient to repair a combined vena caval and hepatic venous injury after blunt liver injury. An extended period of normothermic hepatic ischemia was tolerated. Early recognition of retrohepatic venous injury and temporary liver packing to control bleeding and correct hypovolemia are essential before caval occlusion. Hepatic vascular isolation without shunting is an effective simple alternative technique allowing major venous repair in complex liver trauma. PMID:2090188

  16. Testing of cerebrospinal compensatory reserve in shunted and non-shunted patients: a guide to interpretation based on an observational study.

    PubMed Central

    Czosnyka, M; Whitehouse, H; Smielewski, P; Simac, S; Pickard, J D

    1996-01-01

    OBJECTIVE--To design a computerised infusion test to compensate for the disadvantages of Katzman's lumbar infusion method: inadequate accuracy of estimation of the resistance to cerebrospinal fluid outflow and poor predictive value in normal pressure hydrocephalus. METHODS--Accuracy was improved by intracranial pressure signal processing and model analysis for measurement of cerebrospinal compensatory variable. These include the CSF outflow resistance, brain compliance, pressure-volume index, estimated sagittal sinus pressure, CSF formation rate, and other variables. Infusion may be made into the lumbar space, ventricles, or, when assessing shunt function in vivo, the shunt chamber. RESULTS AND CONCLUSIONS--The computerised test has been used for five years in a multicentre study in 350 hydrocephalic patients of various ages, aetiologies, and states of cerebrospinal compensation. The principles of using the test to characterise different types of CSF circulatory disorders in patients presenting with ventricular dilatation, including brain atrophy and normal and high pressure hydrocephalus, are presented and illustrated. Previous studies showed a positive correlation between cerebrospinal compensatory variables and the results of shunting, but such a prediction remains difficult in idiopathic normal pressure hydrocephalus, particularly in elderly patients. The technique is helpful in the assessment of shunt malfunction, including posture-related overdrainage, over-drainage related to the nocturnal B wave activity, and proximal or distal shunt obstruction. The appendix presents an introduction of the mathematical modelling of CSF pressure volume-compensation included in computerised infusion test software. Images PMID:8778261

  17. Ventriculoperitoneal shunt disconnection associated with spontaneous knot formation in the peritoneal catheter.

    PubMed

    Lo, William B; Ramirez, Roberto; Rodrigues, Desiderio; Solanki, Guirish A

    2013-01-01

    A 10-year-old girl underwent distal ventriculoperitoneal (VP) shunt revision 3 weeks earlier and developed further shunt malfunction. During the current shunt revision, a disconnection at the straight connector site in the cervical subcutaneous tissue was confirmed and a knot was identified in the peritoneal catheter. Postoperatively, the patient made a rapid neurological recovery and was discharged 48 h later. This is the first case of VP shunt disconnection associated with a spontaneous distal knot formation. The likely mechanism was that the spontaneously formed knot acted as an anchor at the peritoneal wall, preventing free relative movement of the distal catheter. The resultant tension led to failure at the weakest point of the system, resulting in a disconnection at the proximal straight connector site.

  18. Optimizing the Shunting Schedule of Electric Multiple Units Depot Using an Enhanced Particle Swarm Optimization Algorithm.

    PubMed

    Wang, Jiaxi; Lin, Boliang; Jin, Junchen

    2016-01-01

    The shunting schedule of electric multiple units depot (SSED) is one of the essential plans for high-speed train maintenance activities. This paper presents a 0-1 programming model to address the problem of determining an optimal SSED through automatic computing. The objective of the model is to minimize the number of shunting movements and the constraints include track occupation conflicts, shunting routes conflicts, time durations of maintenance processes, and shunting running time. An enhanced particle swarm optimization (EPSO) algorithm is proposed to solve the optimization problem. Finally, an empirical study from Shanghai South EMU Depot is carried out to illustrate the model and EPSO algorithm. The optimization results indicate that the proposed method is valid for the SSED problem and that the EPSO algorithm outperforms the traditional PSO algorithm on the aspect of optimality. PMID:27436998

  19. Design and test of a novel isolator with negative resistance electromagnetic shunt damping

    NASA Astrophysics Data System (ADS)

    Yan, Bo; Zhang, Xinong; Niu, Hongpan

    2012-03-01

    This paper proposes a negative resistance electromagnetic shunt damping vibration isolator and investigates the effectiveness of the isolator. The isolator consists of a shunt circuit and a pair of electromagnet and permanent magnets that are pasted onto a box-shaped spring. A kind of negative resistance shunt impedance is proposed to cancel the inherent resistance of the electromagnet. The electromechanical coupling coefficient and the electromagnetic damping force calculation formula are obtained by Biot-Savart’s law and Ampère’s law, respectively. A single degree of freedom system is employed to verify the performance of the proposed isolator. The governing equation is established. The performance of the proposed isolator under a half-cycle sine pulse is investigated and discussed. Experiments were carried out and the results agreed well with the numerical predictions. Both the results demonstrate that the negative resistance electromagnetic shunt damping vibration isolator could suppress vibration transmitted to the structure effectively.

  20. Optimizing the Shunting Schedule of Electric Multiple Units Depot Using an Enhanced Particle Swarm Optimization Algorithm

    PubMed Central

    Jin, Junchen

    2016-01-01

    The shunting schedule of electric multiple units depot (SSED) is one of the essential plans for high-speed train maintenance activities. This paper presents a 0-1 programming model to address the problem of determining an optimal SSED through automatic computing. The objective of the model is to minimize the number of shunting movements and the constraints include track occupation conflicts, shunting routes conflicts, time durations of maintenance processes, and shunting running time. An enhanced particle swarm optimization (EPSO) algorithm is proposed to solve the optimization problem. Finally, an empirical study from Shanghai South EMU Depot is carried out to illustrate the model and EPSO algorithm. The optimization results indicate that the proposed method is valid for the SSED problem and that the EPSO algorithm outperforms the traditional PSO algorithm on the aspect of optimality. PMID:27436998

  1. Congenital extrahepatic portosystemic shunt complicated by the development of hepatocellular carcinoma.

    PubMed

    Sharma, Ruchi; Suddle, Abid; Quaglia, Alberto; Peddu, Praveen; Karani, John; Satyadas, Thomas; Heaton, Nigel

    2015-10-01

    Congenital extrahepatic portosystemic shunt, also known as Abernethy malformation, is a rare congenital malformation. It causes shunting of blood through a communication between the portal and systemic veins such as a patent ductus venous. We report 3 cases of Abernethy malformation complicated by the development of hepatocellular carcinoma. Additionally, we comprehensively reviewed all previously reported cases and highlighted common features that may help in early diagnosis and appropriate management. Patients with Abernethy malformation may have an increased propensity to develop hepatocellular carcinoma. All 5 previously reported cases, plus the three of our patients, have a type 1 (complete) shunt suggesting a role for absent portal blood flow in the pathogenesis of hepatocellular carcinoma. Congenital extrahepatic portosystemic shunt should be sought for in cases with raised serum ammonia, hepatic encephalopathy or hepatocellular carcinoma in the absence of cirrhosis. PMID:26459734

  2. Ventriculoatrial shunt infection due to Cryptococcus neoformans: an ultrastructural and quantitative microbiological study.

    PubMed

    Walsh, T J; Schlegel, R; Moody, M M; Costerton, J W; Salcman, M

    1986-03-01

    A 28-year-old man presented with hydrocephalus due to an infection by Cryptococcus neoformans involving his ventriculoatrial shunt. Ultrastructural studies of the ventriculoatrial shunt demonstrated yeastlike organisms consistent with C. neoformans within a biofilm on the appliance. Quantitative microbiological studies of segments of the shunt demonstrated C. neoformans in a concentration gradient from 9 X 10(6) colony-forming units (CFU)/0.5-cm section involving the ventricular portion of the catheter to 1 X 10(2) CFU/0.5-cm section at the vascular tip. The clinical, microbiological, and ultrastructural data suggest that this cryptococcal infection started as a ventriculitis or encephalitis with extension to the meningeal surface. Future application of these methods may further elucidate the pathogenesis of ventriculoatrial shunt infections.

  3. Anal extrusion of migrated ventriculo-peritoneal shunt catheter: An unusual complication and review of literature

    PubMed Central

    Sarkari, Avijit; Borkar, Sachin A.; Mahapatra, A. K.

    2016-01-01

    Authors present an unusual case of anal extrusion of peritoneal end of ventriculo-peritoneal shunt in a 2-year-old male child. Pertinent literature is reviewed regarding this rare complication of a very commonly performed neurosurgical procedure.

  4. Unusual Gross Pneumocephalus and Pneumoperitoneum after VP Shunt Surgery: A Case Report.

    PubMed

    A, Khanolkar; Yk, Sarin

    2015-01-01

    We report an unusual case where a two-month infant developed a simultaneous and spontaneous pneumocephalus and gross pneumoperitoneum along with progressive surgical emphysema after VP shunt procedure.

  5. Detailed analysis of amplitude and recurrence times of LP activity at Mt. Etna Volcano, Italy.

    NASA Astrophysics Data System (ADS)

    Cauchie, L.; Saccorotti, G.; Bean, C.; de Barros, L.

    2012-04-01

    Long-Period (LP) events recorded on many volcanoes worldwide are thought to be associated with conduit resonance triggered by fluid flow instabilities throughout the volcano plumbing system. The rate of Long-Period activity, however, varies greatly depending on the particular volcano taken into account. At Piton de la Fournaise, for instance, LP event rate is on the order of 10 events /year, while at Mt. Etna it is not unusual to observe several thousands of events per month. This work is aimed at improving our understanding of the LP source mechanism through a statistical analysis of detailed LP catalogues. The behaviour of LP activity is compared with the empirical laws governing earthquakes recurrence (e.g., Gutenberg-Richter [GR] and Omori's laws), in order to understand what relationships, if any, exist between these two apparently different earthquake classes. In particular, we investigated the amplitude and the recurrence time of LP activity on Mt. Etna, Italy, using data from a temporary network (inter-station distance ~5km ) and a small-aperture array (inter-station distance ~50m) deployed in 2005. Some 13,000 LP events were detected in August 2005 through a short-term average/long-term average (STA/LTA) method. Directional properties of these events were obtained by applying a Plane Wave Fitting (PWF) method to data from the small array. The different directions of propagation measured for such events suggest that at least two different sources are active. From PWF alone we were not able to isolate the contribution of individual sources without ambiguity. LP signals, however, exhibit a high degree of waveform similarity, thus providing a criterion for classification / source separation. Using correlation analysis, we then grouped the events into families containing comparable waveforms. By waveforms stacking, we obtained a representative, template event for each family. These template signals were then used for a Matched-Filtering of the continuous data

  6. Genetic and functional analysis of the otosclerosis-like condition of the LP/J mouse.

    PubMed

    Henry, K R; Chole, R A

    1987-01-01

    The LP/J mouse is the only available genetic model for otosclerosis. The otosclerosis-like condition of the LP/J mouse resembles the human condition in several ways, although there are differences in the two species in the most common locus of the dysplastic otic lesions. The mouse model would be more useful if its auditory dysfunction and genetic inheritance could also be compared with the human disease. Matings of the otosclerosis-like LP/J and the normal CBA/J inbred mice were used to generate F1 and backcross generations. The F1 showed neither functional (electrocochleographic) nor anatomical abnormalities, indicating a recessive nature of the mouse genetic disease. This is in contrast to some reports of dominance (with incomplete penetrance) of otosclerosis in humans. No evidence of X-chromosome-linked genetic influence was found in the mouse, in agreement with the human condition. These interpretations were confirmed in tests of the backcross of the F1 to the CBA/J parental genotype (BC). The anatomical and functional abnormalities were present in some of the backcrosses of the F1 to the LP/J parental genotype (BL). A comparison of bone-conducted and air-conducted electrocochleographic responses provided evidence for both conductive and sensorineural losses in the LP/J and BL mice.

  7. Analysis of error floor of LDPC codes under LP decoding over the BSC

    SciTech Connect

    Chertkov, Michael; Chilappagari, Shashi; Vasic, Bane; Stepanov, Mikhail

    2009-01-01

    We consider linear programming (LP) decoding of a fixed low-density parity-check (LDPC) code over the binary symmetric channel (BSC). The LP decoder fails when it outputs a pseudo-codeword which is not a codeword. We propose an efficient algorithm termed the instanton search algorithm (ISA) which, given a random input, generates a set of flips called the BSC-instanton and prove that: (a) the LP decoder fails for any set of flips with support vector including an instanton; (b) for any input, the algorithm outputs an instanton in the number of steps upper-bounded by twice the number of flips in the input. We obtain the number of unique instantons of different sizes by running the ISA sufficient number of times. We then use the instanton statistics to predict the performance of the LP decoding over the BSC in the error floor region. We also propose an efficient semi-analytical method to predict the performance of LP decoding over a large range of transition probabilities of the BSC.

  8. LP-211 is a brain penetrant selective agonist for the serotonin 5-HT(7) receptor.

    PubMed

    Hedlund, Peter B; Leopoldo, Marcello; Caccia, Silvio; Sarkisyan, Gor; Fracasso, Claudia; Martelli, Giuliana; Lacivita, Enza; Berardi, Francesco; Perrone, Roberto

    2010-08-30

    We have determined the pharmacological profile of the new serotonin 5-HT(7) receptor agonist N-(4-cyanophenylmethyl)-4-(2-diphenyl)-1-piperazinehexanamide (LP-211). Radioligand binding assays were performed on a panel of 5-HT receptor subtypes. The compound was also evaluated in vivo by examining its effect on body temperature regulation in mice lacking the 5-HT(7) receptor (5-HT(7)(-/-)) and their 5-HT(7)(+/+) sibling controls. Disposition studies were performed in mice of both genotypes. It was found that LP-211 was brain penetrant and underwent metabolic degradation to 1-(2-diphenyl)piperazine (RA-7). In vitro binding assays revealed that RA-7 possessed higher 5-HT(7) receptor affinity than LP-211 and a better selectivity profile over a panel of 5-HT receptor subtypes. In vivo it was demonstrated that LP-211, and to a lesser degree RA-7, induced hypothermia in 5-HT(7)(+/+) but not in 5-HT(7)(-/-) mice. Our results suggest that LP-211 can be used as a 5-HT(7) receptor agonist in vivo. PMID:20600619

  9. Broadband source inversion of Long-Period (LP) events on Turrialba volcano, Costa Rica

    NASA Astrophysics Data System (ADS)

    Lokmer, I.; Thun, J.; Bean, C. J.

    2015-12-01

    A typical moment-tensor (MT) solution of long-period (LP) volcanic signals comprises a tensile crack source mechanism and a pulsing or resonating source-time function (STF). However, due to the small magnitudes of LP events, only the most energetic part of the signals (as seen from velocity waveforms) is used in inversions. Ground displacement periods longer than 5 seconds - if they exist - are very difficult (if not impossible) to recover from such small signals due to the contamination of the signal by high-amplitude microseisms and the velocity signal base-line fluctuations (long-period instrumental noise). Consequently, the source-time functions (STF) obtained in LP inversions are band-limited representations of the true displacements in the source. Here we use a good-quality LP dataset recorded near the summit of Turrialba volcano. Aided by results from step table laboratory experiments we carefully recover the broadband ground motion displacement, containing frequencies much lower than 0.3 Hz observed on the velocity seismograms. The resulting MT solution that we recover is a classical earthquake "ramp" function, rather than a pulsing or oscillating waveform. We suggest that this new observation will contribute to a better understanding of LP seismicity.

  10. Immunomodulatory Effects of Lactobacillus plantarum Lp62 on Intestinal Epithelial and Mononuclear Cells.

    PubMed

    Ferreira Dos Santos, Thalis; Alves Melo, Tauá; Almeida, Milena Evangelista; Passos Rezende, Rachel; Romano, Carla Cristina

    2016-01-01

    Probiotic lactic acid bacteria are known for their ability to modulate the immune system. They have been shown to inhibit inflammation in experiments with animal models, cell culture, and clinical trials. The objective of this study was to elucidate the anti-inflammatory potential of Lactobacillus plantarum Lp62, isolated from cocoa fermentation, in a cell culture model. Lp62 inhibited IL-8 production by Salmonella Typhi-stimulated HT-29 cells and prevented the adhesion of pathogens to these epithelial cells. The probiotic strain was able to modulate TNF-α, IL1-β, and IL-17 secretion by J774 macrophages. J774 activation was reduced by coincubation with Lp62. PBMC culture showed significantly higher levels of CD4(+)CD25(+) T lymphocytes following treatment with Lp62. Probiotics also induced increased IL-10 secretion by mononuclear cells. L. plantarum Lp62 was able to inhibit inflammatory stimulation in epithelial cells and macrophages and activated a tolerogenic profile in mononuclear cells of healthy donors. These results indicate this strain for a possible application in the treatment or prevention of inflammatory diseases. PMID:27446958

  11. Immunomodulatory Effects of Lactobacillus plantarum Lp62 on Intestinal Epithelial and Mononuclear Cells

    PubMed Central

    Alves Melo, Tauá; Almeida, Milena Evangelista; Passos Rezende, Rachel

    2016-01-01

    Probiotic lactic acid bacteria are known for their ability to modulate the immune system. They have been shown to inhibit inflammation in experiments with animal models, cell culture, and clinical trials. The objective of this study was to elucidate the anti-inflammatory potential of Lactobacillus plantarum Lp62, isolated from cocoa fermentation, in a cell culture model. Lp62 inhibited IL-8 production by Salmonella Typhi-stimulated HT-29 cells and prevented the adhesion of pathogens to these epithelial cells. The probiotic strain was able to modulate TNF-α, IL1-β, and IL-17 secretion by J774 macrophages. J774 activation was reduced by coincubation with Lp62. PBMC culture showed significantly higher levels of CD4+CD25+ T lymphocytes following treatment with Lp62. Probiotics also induced increased IL-10 secretion by mononuclear cells. L. plantarum Lp62 was able to inhibit inflammatory stimulation in epithelial cells and macrophages and activated a tolerogenic profile in mononuclear cells of healthy donors. These results indicate this strain for a possible application in the treatment or prevention of inflammatory diseases. PMID:27446958

  12. Ischemic stroke patients with active malignancy or extracardiac shunts are more likely to have a right-to-left shunt found by TCD than echocardiogram.

    PubMed

    de Havenon, Adam; Moore, Anne; Sultan-Qurraie, Ali; Majersik, Jennifer J; Stoddard, Greg; Tirschwell, David

    2015-10-01

    Although the association between patent foramen ovale and ischemic stroke is controversial, the evaluation for a right-to-left shunt remains part of the standard workup for cryptogenic stroke. Transthoracic and transesophageal echocardiogram (TTE and TEE) are the screening test and gold standard to evaluate for right-to-left shunt, respectively. Studies comparing TTE or TEE to transcranial Doppler (TCD) have shown that 15-25 % of patients test positive for right-to-left shunt on TCD but are negative on TTE or TEE. We sought to further explore this phenomenon in patients with recent ischemic stroke. Between 2011 and 2013, 109 ischemic stroke patients had both a TCD and TTE or TEE bubble study. We abstracted 12 comorbid medical conditions and stroke subtype according to the TOAST classification. The majority of TCD and TTE or TEE showed agreement on right-to-left shunt status (80/109, 73 %). Two percent (2/109) of patients were negative on TCD and positive on TTE or TEE, while 25 % (27/109) had a positive TCD and negative TTE or TEE (TCD+Echo-). The TCD+Echo- patients were more likely to have active malignancy and the delayed arrival of contrast bubbles than the remainder of the cohort (15 vs. 2 %, p = 0.032; 51 vs. 18 %, p = 0.001). Our results confirm previous reports that TCD is superior to echocardiography in the detection of right-to-left shunt. The TCD+Echo- patients were more likely to have active malignancy and findings suggestive of an extracardiac shunt. These results could lead to more comprehensive evaluation for occult malignancy or a pulmonary arteriovenous malformation, both potentially treatable etiologies of ischemic stroke.

  13. Impact of shunt capacitor banks on substation surge environment and surge arrester applications

    SciTech Connect

    1996-10-01

    The introduction of high voltage shunt capacitor banks on a power system can result in a number of overvoltage problems that tend to be associated with capacitor switching. Proper application of surge arresters near a shunt capacitor bank requires careful analysis of the power system, the switching devices and their arrangements, the insulation level of nearby equipment, the type of grounding, and the arrester energy dissipation duty.

  14. Bilateral Papilledema as the First Sign of Ventriculoperitoneal Shunt Dysfunction§

    PubMed Central

    Serna-Ojeda, Juan Carlos; Aguirre-Mireles, Montserrat; Camargo-Suarez, Mayra Fabiola

    2015-01-01

    A 12 year-old girl patient with a history of ventriculoperitoneal shunt placement at the age of 6 months presented with progressive bilateral decrease in visual acuity. Ophthalmologic examination was consistent with bilateral papilledema. No other systemic manifestations of increased intracranial pressure were evident and laboratory work-up excluded other inflammatory or infectious processes. We present here an interesting case of a patient with ophthalmologic manifestations as the initial finding of ventriculoperitoneal shunt dysfunction. PMID:25834657

  15. Experimental Percutaneous Extrahepatic Portacaval Shunt Creation by Transjugular Approach in Swine

    SciTech Connect

    Seong, Chang Kyu; Pavcnik, Dusan Uchida, Barry T.; Anai, Hiroshi; Timmermans, Hans; Niyyati, Mahtab; Corless, Christopher L.; Correa, Luiz O.; Keller, Frederick S.; Roesch, Josef

    2005-06-15

    The purpose of the study was to evaluate the feasibility of the creation of a percutaneous extrahepatic portacaval shunt (PEPS) in swine by a transjugular approach and to find a suitable stent-graft to use in PEPS. In 12 swine, the extrahepatic portal vein (PV) was entered from the inferior vena cava (IVC) by a needle system introduced from the transjugular approach. A catheter introduced through the transhepatic approach served as a target. Five types of stent-graft consisting of homemade Z stents and a polytetrafluoethylene cover were explored for PEPS creation. Eight animals had follow-up venograms up to 6 weeks or until the shunt became severely stenotic. Gross and histologic examinations were performed after the final follow-up venography. The PV punctures and stent-graft placement were difficult, but the PEPS was established in all animals. In four animals, the stent-graft failed to adequately cover the tract, causing severe hemorrhage. Only two shunts remained patent up to 6 weeks. The other shunts exhibited severe stenosis or occlusion. At gross examination, all shunts traversed the liver parenchyma of the caudate lobe surrounding the IVC. The extravascular PEPS portion was 4 mm to 2 cm long. All shunts entered the PV close to the splenomesenteric junction and exhibited neointimal formation. Shunt stenoses were caused by neointimal hyperplasia and occlusions by a superimposed thrombus. PEPS can be created by the transjugular approach in swine, but only the PV shunt entrance is extrahepatic. None of the tested rigid stent-grafts were suitable for PEPS creation. A short flexible stent-graft with flanged ends is suggested for further exploration.

  16. Superconducting FCL using a combined inducted magnetic field trigger and shunt coil

    DOEpatents

    Tekletsadik, Kasegn D.

    2007-10-16

    A single trigger/shunt coil is utilized for combined induced magnetic field triggering and shunt impedance. The single coil connected in parallel with the high temperature superconducting element, is designed to generate a circulating current in the parallel circuit during normal operation to aid triggering the high temperature superconducting element to quench in the event of a fault. The circulating current is generated by an induced voltage in the coil, when the system current flows through the high temperature superconducting element.

  17. Robotic-assisted hysterectomy in a patient with a ventriculoperitoneal shunt.

    PubMed

    Bush, Stephen H; Greg Heywood, S; Calhoun, Byron C

    2011-12-01

    There are several articles in the literature reporting laparoscopic surgery in patients with ventriculoperitoneal shunts (VPSs). Although the majority of these conclude that a pneumoperitoneum in these patients is safe, there are other reports indicating possible complications of the insufflation. This is the first known report of a robotic-assisted hysterectomy performed on a patient with a VPS and the management of the shunt during the procedure. PMID:27628120

  18. Optimal Surgical Management Using a Classic Blalock-Taussig Shunt for an Infected Pseudoaneurysm After a Modified Blalock-Taussig Shunt Procedure.

    PubMed

    Okada, Noritaka; Murayama, Hiroomi; Hasegawa, Hiroki

    2016-05-01

    We present 2 cases of a 3-month-old girl and boy who were diagnosed with an infected pseudoaneurysm 2 months after undergoing left-sided modified Blalock-Taussig shunt (mBTS) operations for pulmonary atresia. Because the shunts in both cases were nearly obstructed, they underwent a 2-stage surgical approach: classic BTS operations through a right thoracotomy to establish sufficient pulmonary flow and infected graft removal through a median sternotomy after close observation of the state of the aneurysms. By utilizing autologous tissue from a different thoracic entry, both patients were successfully managed and recovered without any recurrence of infection. PMID:27106441

  19. Spontaneous bacterial peritonitis causing Serratia marcescens and Proteus mirabilis ventriculoperitoneal shunt infection. Case report.

    PubMed

    Tumialán, Luis M; Lin, Franklin; Gupta, Sanjay K

    2006-08-01

    The authors report their experience treating a polymicrobial ventriculoperitoneal (VP) shunt infection in a developmentally delayed 21-year-old woman. Cerebrospinal fluid (CSF) cultures grew Serratia marcescens and Proteus mirabilis. On admission and throughout her hospitalization, results of physical examination of her abdomen were normal, and radiographic studies showed no evidence of bowel perforation or pseudocyst formation. Contrast-enhanced computed tomography of the abdomen revealed a small fluid collection. After a course of intravenous gentamicin and imipenem with cilastatin in conjunction with intrathecal gentamicin, the infection was resolved and the VP shunt was reimplanted. Although VP shunt infections are not uncommon, S. marcescens as a causative agent is exceedingly rare and potentially devastating. Only two previous cases of S. marcescens shunt infection have been reported in the literature. Authors reporting on S. marcescens infections in the central nervous system (CNS) have observed significant morbidity and death. Although more common, the presence of P. mirabilis in the CSF is still rare and highly suggestive of bowel perforation, which was absent in this patient. Spontaneous bacterial peritonitis was the likely source from which these bacteria gained entrance into the VP shunt system, eventually causing ventriculitis in this patient. The authors conclude that in light of the high morbidity associated with S. marcescens infection of the CNS, intrathecal administration of gentamicin should be strongly considered as part of first-line therapy for S. marcescens infections in VP shunts.

  20. Mechanism for measurement of flow rate of cerebrospinal fluid in hydrocephalus shunts.

    PubMed

    Rajasekaran, Sathish; Kovar, Spencer; Qu, Peng; Inwald, David; Williams, Evan; Qu, Hongwei; Zakalik, Karol

    2014-01-01

    The measurement of the flow rate of cerebrospinal fluid (CSF) or existence of CSF flow inside the shunt tube after shunt implant have been reported as tedious process for both patients and doctors; this paper outlines a potential in vitro flow rate measurement method for CSF in the hydrocephalus shunt. The use of implantable titanium elements in the shunt has been proposed to allow for an accurate temperature measurement along the shunt for prediction of CSF flow rate. The CSF flow velocity can be deduced by decoupling the thermal transfer in the measured differential time at a pair of measurement spots of the titanium elements. Finite element analyses on the fluidic and thermal behaviors of the shunt system have been conducted. Preliminary bench-top measurements on a simulated system have been carried out. The measured flow rates, ranging from 0.5 mm/sec to 1.0 mm/sec, which is clinically practical, demonstrate good agreements with the simulation results.

  1. Hydrocephalus and Ventriculoperitoneal Shunts: Modes of Failure and Opportunities for Improvement.

    PubMed

    Jorgensen, Julianne; Williams, Corin; Sarang-Sieminski, Alisha

    2016-01-01

    Between 0.5 and 4 of every 1000 children are born with hydrocephalus. Hydrocephalus is an over-accumulation of cerebrospinal fluid (CSF) in the ventricles of the brain, which can affect cognitive function, vision, appetite, and cranial nerve function. Left untreated, hydrocephalus can result in death. The current treatment for hydrocephalus uses ventriculoperitoneal (VP) shunts with valves to redirect CSF from the ventricles into the peritoneum. Shunt technology is limited by a number of complications, which include infection after implantation, shunt obstruction due to clot formation or catheter obstruction by scar tissue or choroid plexus, disconnection and tubing migration, and overdrainage or underdrainage of CSF due to valve malfunction. While modifications to surgical procedures and shunt design have been introduced, only modest improvements in outcomes have been observed. Here we provide an overview of hydrocephalus, VP shunts, and their modes of failure, and we identify numerous areas of opportunity for biomedical engineers and physicians to collaborate to improve the performance of VP shunts.

  2. Percutaneous Retroperitoneal Splenorenal Shunt for Symptomatic Portal Vein Thrombosis After Liver Transplantation.

    PubMed

    Pulitano, C; Rogan, C; Sandroussi, C; Verran, D; McCaughan, G W; Waugh, R; Crawford, M

    2015-08-01

    Acute or recurrent bleeding from ectopic varices is a potentially life-threatening condition in rare patients with extrahepatic complete portal vein thrombosis (PVT) after liver transplantation (LT). In this setting, the role of interventional radiology is very limited and surgical shunts, in particular splenorenal shunts are usually used, despite the high associated mortality. We present the first reports of the clinical use of a new minimally invasive technique, percutaneous retroperitoneal splenorenal shunt (PRESS), in two LT recipients with life-threatening variceal hemorrhage secondary to PVT. Both patients had a successful PRESS using a transplenic approach with resolution of bleeding, avoiding the need for a potentially complicated laparotomy. The PRESS procedure is a useful addition to the interventional armamentarium that can be used in cases unsuitable for surgical shunt, and refractory to endoscopic management. In the future, this technique may be an alternative to surgical shunts as the standard procedure in patients with extra-hepatic PVT, just as the transjugular intrahepatic portosystemic shunt (TIPS) procedure has become for the management of portal hypertension in the absence of PVT. Longer-term follow-up will be needed to establish the long-term success of this procedure. PMID:25980940

  3. Standard Trabeculectomy and Ex-PRESS Miniature Glaucoma Shunt: A Comparative Study and Literature Review

    PubMed Central

    Zunz, Eran; Tzur, Rotem; Kurtz, Shimon; Shemesh, Gabi

    2015-01-01

    Purpose: The aim of this study was to compare the efficacy and safety between standard trabeculectomy and the Ex-PRESS shunt implantation. Methods: A retrospective review of the records of 100 eyes of 100 patients who underwent trabeculectomy or Ex-PRESS shunt implantation between July 2010 and June 2012 was conducted. Of these, 61 (61%) eyes underwent trabeculectomy and 39 (39%) eyes underwent Ex-PRESS shunt implantation. Demographic information, glaucoma type, surgical details, preoperative, and postoperative data including intraocular pressure (IOP), number of medications, reoperation, and occurrence of any complications were recorded. Results: No differences in IOP reduction or number of postoperative IOP-lowering medications were demonstrated between the 2 procedures. Success rates were 86.9% for trabeculectomy and 84.6% for Ex-PRESS shunt. Rates of failure and hypotony were not significantly different between the groups. No parameter was correlated with success or failure of any procedure. Conclusions: Standard trabeculectomy and Ex-PRESS shunt have similar efficacy and safety profiles. As the Ex-PRESS shunt is considerably more expensive, its use may be unjustified, especially as a primary procedure. PMID:24633088

  4. Mechanism for measurement of flow rate of cerebrospinal fluid in hydrocephalus shunts.

    PubMed

    Rajasekaran, Sathish; Kovar, Spencer; Qu, Peng; Inwald, David; Williams, Evan; Qu, Hongwei; Zakalik, Karol

    2014-01-01

    The measurement of the flow rate of cerebrospinal fluid (CSF) or existence of CSF flow inside the shunt tube after shunt implant have been reported as tedious process for both patients and doctors; this paper outlines a potential in vitro flow rate measurement method for CSF in the hydrocephalus shunt. The use of implantable titanium elements in the shunt has been proposed to allow for an accurate temperature measurement along the shunt for prediction of CSF flow rate. The CSF flow velocity can be deduced by decoupling the thermal transfer in the measured differential time at a pair of measurement spots of the titanium elements. Finite element analyses on the fluidic and thermal behaviors of the shunt system have been conducted. Preliminary bench-top measurements on a simulated system have been carried out. The measured flow rates, ranging from 0.5 mm/sec to 1.0 mm/sec, which is clinically practical, demonstrate good agreements with the simulation results. PMID:25570411

  5. Effect of rapamycin on hepatic osteodystrophy in rats with portasystemic shunting

    PubMed Central

    van der Merwe, Schalk W; Conradie, Maria M; Bond, Robert; Olivier, Brenda J; Fritz, Elongo; Nieuwoudt, Martin; Delport, Rhena; Slavik, Tomas; Engelbrecht, Gert; Kahn, Del; Shephard, Enid G; Kotze, Maritha J; de Villiers, Nico P; Hough, Stephen

    2006-01-01

    AIM: To study if T-cell activation related to portasystemic shunting causes osteoclast-mediated bone loss through RANKL-dependent pathways. We also investigated if T-cell inhibition using rapamycin would protect against bone loss in rats. METHODS: Portasystemic shunting was performed in male Sprague-Dawley rats and rapamycin 0.1 mg/kg was administered for 15 wk by gavage. Rats received powderized chow and supplemental feeds to prevent the effects of malnutrition on bone composition. Weight gain and growth was restored after surgery in shunted animals. At termination, biochemical parameters of bone turnover and quantitative bone histology were assessed. Markers of T-cell activation, inflammatory cytokine production, and RANKL-dependent pathways were measured. In addition, the roles of IGF-1 and hypogonadism were investigated. RESULTS: Portasystemic shunting caused low turnover osteoporosis that was RANKL independent. Bone resorbing cytokine levels, including IL-1, IL-6 and TNFα, were not increased in serum and TNFα and RANKL expression were not upregulated in PBMC. Portasystemic shunting increased the circulating CD8+ T-cell population. Rapamycin decreased the circulating CD8+ T-cell population, increased CD8+ CD25+ T-regulatory cell population and improved all parameters of bone turnover. CONCLUSION: Osteoporosis caused by portasystemic shunting may be partially ameliorated by rapamycin in the rat model of hepatic osteodystrophy. PMID:16874862

  6. Unusual shunt for symptomatic portal vein thrombosis after liver transplantation - Clatworthy revisited.

    PubMed

    Mali, V P; Robless, P A; Aw, M; Loh, D L; Quak, S H; Prabhakaran, K

    2012-06-01

    PV thrombosis is not an uncommon occurrence following pediatric LT. Symptomatic PHT following PV thrombosis is treated medically, surgical portosystemic shunting (mesorex, splenorenal, and mesocaval) being reserved for refractory cases. A 10-yr-old boy suffered recurrent malena and hemorrhagic shock because of chronic PV thrombosis following LT nine yr ago (1999). Extensive work-up failed to localize the bleeding source. The liver function remained normal. Initial attempts at surgical shunts failed owing to thrombosis (mesocaval 2001, splenorenal, inferior mesenteric-left renal vein, splenic-left external iliac vein 2008). In this situation, we performed a Clatworthy shunt by anastomosing the divided lower end of the LCIV to the side of SMV. There was a single, large caliber anastomosis. Post-operatively, the malena stopped completely, and clinically, there was no lower limb edema or encephalopathy. Doppler USG revealed persistence of hepatopetal flow within the portal collaterals. Follow-up at two yr reveals stable hepatic function with a patent shunt. To the best of our knowledge, we are not aware of a Clatworthy shunt being performed in a transplant setting. We reviewed the literature pertaining to this shunt in non-transplant patients with PHT.

  7. Hydrocephalus and Ventriculoperitoneal Shunts: Modes of Failure and Opportunities for Improvement.

    PubMed

    Jorgensen, Julianne; Williams, Corin; Sarang-Sieminski, Alisha

    2016-01-01

    Between 0.5 and 4 of every 1000 children are born with hydrocephalus. Hydrocephalus is an over-accumulation of cerebrospinal fluid (CSF) in the ventricles of the brain, which can affect cognitive function, vision, appetite, and cranial nerve function. Left untreated, hydrocephalus can result in death. The current treatment for hydrocephalus uses ventriculoperitoneal (VP) shunts with valves to redirect CSF from the ventricles into the peritoneum. Shunt technology is limited by a number of complications, which include infection after implantation, shunt obstruction due to clot formation or catheter obstruction by scar tissue or choroid plexus, disconnection and tubing migration, and overdrainage or underdrainage of CSF due to valve malfunction. While modifications to surgical procedures and shunt design have been introduced, only modest improvements in outcomes have been observed. Here we provide an overview of hydrocephalus, VP shunts, and their modes of failure, and we identify numerous areas of opportunity for biomedical engineers and physicians to collaborate to improve the performance of VP shunts. PMID:27652453

  8. Lp stability for entropy solutions of scalar conservation laws with strict convex flux

    NASA Astrophysics Data System (ADS)

    Adimurthi; Ghoshal, Shyam Sundar; Veerappa Gowda, G. D.

    Here we consider the scalar convex conservation laws in one space dimension with strictly convex flux which is in C1. Existence, uniqueness and L1 contractivity were proved by Kružkov [14]. Using the relative entropy method, Leger showed that for a uniformly convex flux and for the shock wave solutions, the L2 norm of a perturbed solution relative to the shock wave is bounded by the L2 norm of the initial perturbation. Here we generalize the result to Lp norm for all 1⩽p<∞. Also we show that for the non-shock wave solution, Lp norm of the perturbed solution relative to the modified N-wave is bounded by the Lp norm of the initial perturbation for all 1⩽p<∞.

  9. Effects of topography and crustal heterogeneities on the source estimation of LP event at Kilauea volcano

    USGS Publications Warehouse

    Cesca, S.; Battaglia, J.; Dahm, T.; Tessmer, E.; Heimann, S.; Okubo, P.

    2008-01-01

    The main goal of this study is to improve the modelling of the source mechanism associated with the generation of long period (LP) signals in volcanic areas. Our intent is to evaluate the effects that detailed structural features of the volcanic models play in the generation of LP signal and the consequent retrieval of LP source characteristics. In particular, effects associated with the presence of topography and crustal heterogeneities are here studied in detail. We focus our study on a LP event observed at Kilauea volcano, Hawaii, in 2001 May. A detailed analysis of this event and its source modelling is accompanied by a set of synthetic tests, which aim to evaluate the effects of topography and the presence of low velocity shallow layers in the source region. The forward problem of Green's function generation is solved numerically following a pseudo-spectral approach, assuming different 3-D models. The inversion is done in the frequency domain and the resulting source mechanism is represented by the sum of two time-dependent terms: a full moment tensor and a single force. Synthetic tests show how characteristic velocity structures, associated with shallow sources, may be partially responsible for the generation of the observed long-lasting ringing waveforms. When applying the inversion technique to Kilauea LP data set, inversions carried out for different crustal models led to very similar source geometries, indicating a subhorizontal cracks. On the other hand, the source time function and its duration are significantly different for different models. These results support the indication of a strong influence of crustal layering on the generation of the LP signal, while the assumption of homogeneous velocity model may bring to misleading results. ?? 2008 The Authors Journal compilation ?? 2008 RAS.

  10. Serum Lp(a) lipoprotein concentration and outcome of thrombolytic treatment for myocardial infarction.

    PubMed Central

    MBewu, A. D.; Durrington, P. N.; Mackness, M. I.; Hunt, L.; Turkie, W. H.; Creamer, J. E.

    1994-01-01

    BACKGROUND--Lp(a) lipoprotein has structural homology with plasminogen and has been shown to inhibit plasminogen activation in vitro. OBJECTIVE--To determine whether the serum concentration of Lp(a) lipoprotein present when streptokinase was given in acute myocardial infarction influenced the outcome as judged by electrocardiographic methods. PATIENTS AND DESIGN--Serum Lp(a) lipoprotein concentration was measured in 135 consecutive patients admitted with a diagnosis of acute myocardial infarction who received streptokinase treatment. Recovery from myocardial injury was assessed by the reduction in the sum of ST segment elevation measured from the J point (STJ) in the electrocardiogram immediately before streptokinase was given compared with that three hours later. RESULTS--The serum Lp(a) lipoprotein concentrations were measured within 12 hours of the onset of symptoms of myocardial infarction and were higher than in healthy reference populations. Recovery from myocardial infarction could be assessed from the STJ in 116 patients (86% of the series). Those in whom it could not had bundle branch block, left ventricular hypertrophy, did not survive three hours, or had started intravenous nitrate treatment or some other clinical procedure before or at the time the second electrocardiogram was to be recorded. Patients with reductions in STJ after streptokinase that were > 4 mm (the median decrease) had mean (range) serum Lp(a) lipoprotein concentrations of 41.0 (0.8-220) mg/dl and those with a smaller reduction in STJ had concentrations of 29.1 (1.7-151) mg/dl. The difference was not statistically significant. CONCLUSION--In this study Lp(a) lipoprotein concentration did not significantly influence the outcome of thrombolytic treatment with streptokinase. PMID:8198880

  11. Inhibitors for the bacterial ectonucleotidase Lp1NTPDase from Legionella pneumophila.

    PubMed

    Fiene, Amelie; Baqi, Younis; Malik, Enas M; Newton, Patrice; Li, Wenjin; Lee, Sang-Yong; Hartland, Elizabeth L; Müller, Christa E

    2016-09-15

    Legionella pneumophila is an aerobic, Gram-negative bacterium of the genus Legionella, which constitutes the major causative agent of Legionnaires' disease. Recently a nucleoside triphosphate diphosphohydrolase (NTPDase) from L. pneumophila was identified and termed Lp1NTPDase; it was found to be a structural and functional homolog of mammalian NTPDases catalyzing the hydrolysis of ATP to ADP and ADP to AMP. Its activity is believed to contribute to the virulence of Legionella pneumophila. Therefore Lp1NTPDase inhibitors are considered as novel antibacterial drugs. However, only weakly potent compounds are available so far. In the present study, a capillary electrophoresis (CE)-based enzyme assay for monitoring the Lp1NTPDase activity was established. The enzymatic reaction was performed in a test tube followed by separation of substrate and products by CE and subsequent quantification by UV analysis. After kinetic characterization of the enzyme, a series of 1-amino-4-ar(alk)ylamino-2-sulfoanthraquinone derivatives structurally related to the anthraquinone dye Reactive Blue 2, a non-selective ecto-NTPDase inhibitor, was investigated for inhibitory activity on Lp1NTPDase using the CE-based enzyme assay. Derivatives bearing a large lipophilic substituent (e.g., fused aromatic rings) in the 4-position of the 1-amino-2-sulfoanthraquinone showed the highest inhibitory activity. Compounds with IC50 values in the low micromolar range were identified. The most potent inhibitor was 1-amino-4-[phenanthrene-9-yl-amino]-9,10-dioxo-9,10-dihydroanthracene-2-sulfonate (28, PSB-16131), with an IC50-value of 4.24μM. It represents the most potent Lp1NTPDase inhibitor described to date. These findings may serve as a starting point for further optimization. Lp1NTPDase inhibition provides a novel approach for the (immuno)therapy of Legionella infections. PMID:27522579

  12. Oculo-peritoneal shunt: draining aqueous humor to the peritoneum.

    PubMed

    Maldonado-Junyent, Ana; Maldonado-Bas, Arturo; Gonzalez, Andrea; Pueyrredón, Francisco; Maldonado-Junyent, María; Maldonado-Junyent, Arturo; Rodriguez, Diego; Bulacio, Mariano

    2015-01-01

    In 2010, there were estimated to be approximately 60.5 million people with glaucoma. This number is expected to increase to 79.6 million by 2020. In 2010, there were 8.4 million people with bilateral blindness caused by glaucoma, and this number is expected in increase to 11.2 million by 2020. Filtering implants are special devices that have been developed to reduce intraocular pressure in patients with refractory glaucoma. The success rate of these implants is relatively low, and they continue to fail over time. To avoid failure caused by the formation of scar tissue around the implants, attempts have been made to drain the aqueous humor to various sites, including the venous system, lacrimal sac, sinuses, and conjunctival fornix. Recently, a system to shunt aqueous humor from the anterior chamber to the peritoneum has been developed. The surgical technique involved in this system is a modification of the technique currently used by neurosurgeons for the treatment of hydrocephalus. We present the first case operated using this technique.

  13. Integrated fuel cell stack shunt current prevention arrangement

    DOEpatents

    Roche, Robert P.; Nowak, Michael P.

    1992-01-01

    A fuel cell stack includes a plurality of fuel cells juxtaposed with one another in the stack and each including a pair of plate-shaped anode and cathode electrodes that face one another, and a quantity of liquid electrolyte present at least between the electrodes. A separator plate is interposed between each two successive electrodes of adjacent ones of the fuel cells and is unified therewith into an integral separator plate. Each integral separator plate is provided with a circumferentially complete barrier that prevents flow of shunt currents onto and on an outer peripheral surface of the separator plate. This barrier consists of electrolyte-nonwettable barrier members that are accommodated, prior to the formation of the integral separator plate, in corresponding edge recesses situated at the interfaces between the electrodes and the separator plate proper. Each barrier member extends over the entire length of the associated marginal portion and is flush with the outer periphery of the integral separator plate. This barrier also prevents cell-to-cell migration of any electrolyte that may be present at the outer periphery of the integral separator plate while the latter is incorporated in the fuel cell stack.

  14. Chylous ascites and lymphocyst management by peritoneovenous shunt.

    PubMed

    Silk, Y N; Goumas, W M; Douglass, H O; Huben, R P

    1991-09-01

    Although lymphocyst (retroperitoneal lymphocele) is not an uncommon complication after retroperitoneal surgery, with a reported incidence ranging from 0.6% to 48%, the occurrence of chylous ascites is a rare phenomenon. Most reports are anecdotal, and hospital records list the incidence of diagnosis as 0.001% of admissions. Diagnosis of chylous ascites is usually not difficult, inasmuch as aspiration and chemical analysis of the fluid yield the answer. Visualization of retroperitoneal fluid collection by computerized tomography or ultrasonography, however, does always raise the possibility of recurrence of tumor in cases where the primary operation was for cancer. Treatment of smaller lesions can be expectant. Respiratory exercises causing an increase in negative intrathoracic pressure may aid in the movement of fluid through the lymphatics. For larger collections, elemental diets and total parenteral nutrition are also often enough, but surgery is sometimes required. Simple insertion of a peritoneovenous shunt, as in this patient, can be as effective as major operations such as identification and ligation of the offending lymphatic or marsupialization of the cyst.

  15. Hyperglucagonemia and hyperkinetic circulation after portocaval shunt in the rat

    SciTech Connect

    Kravetz, D.; Arderiu, M.; Bosch, J.; Fuster, J.; Visa, J.; Casamitjana, R.; Rodes, J.

    1987-02-01

    The study was aimed at investigating whether increased portal venous inflow (PVI) after portocaval shunt (PCS) in the rat is the result of selective splanchnic vasodilatation or whether it is part of a generalized circulatory disturbance. Rats with PCS and sham-operated controls were studied 2 wk after surgery by measuring cardiac output (CO), PVI, and hepatic artery flow (HAF) with radioactive microspheres (V Cr and UC). Plasma glucagon (GL) was measured by radioimmunoassay. PCS rats had increased CO and reduced arterial pressure and total peripheral resistance. PVI was markedly increased, but this appeared to be part of a generalized circulatory disturbance, since when PVI is expressed as percent of CO no difference is observed between PCS and sham-operated rats, indicating the absence of a preferential splanchnic vasodilatation. GL increased after PCS, and significant correlations were observed between GL and CO and between GL and PVI. HAF increased after PCS but did not compensate the loss of portal flow, evidence by a lower total hepatic flow in PCS rats. These results suggest that PCS induces a hyperkinetic circulatory state in which increased PVI represents its splanchnic manifestation and that increased GL release may be in part responsible for these hemodynamic changes.

  16. Effects of isradipine and other calcium antagonists on arteriovenous-shunt flow in anesthetized rabbits and cats

    SciTech Connect

    Hof, R.P.

    1989-04-17

    The effects of vasodilators on arteriovenous (AV)-shunt flow was investigated in anesthetized cats and rabbits, using the tracer microsphere method. In cats, the calcium antagonist isradipine reduced AV-shunt flow; verapamil showed a similar tendency and nicardipine was without effect. Dihydralazine strongly increased, but nitroglycerin and dipyridamole decreased AV-shunt flow. In rabbits, the effects of isradipine and verapamil were similar to those seen in cats. Sodium nitroprusside had no effect, whereas prazosin, minoxidil, and the potassium-channel activator cromakalim increased AV-shunt flow. The contrasting effects of drugs sharing the same mechanism of action suggest that target-tissue selectivity is more important than the mechanism of action. An increase of AV-shunt flow is unlikely to be beneficial but could be associated with a number of undesirable side effects. It might negatively affect migraine sufferers and, if AV-shunt dilatation shows no tolerance development, it represents an unnecessary hemodynamic burden for the heart.

  17. Long Period (LP) volcanic earthquake source location at Merapi volcano by using dense array technics

    NASA Astrophysics Data System (ADS)

    Metaxian, Jean Philippe; Budi Santoso, Agus; Laurin, Antoine; Subandriyo, Subandriyo; Widyoyudo, Wiku; Arshab, Ghofar

    2015-04-01

    Since 2010, Merapi shows unusual activity compared to last decades. Powerful phreatic explosions are observed; some of them are preceded by LP signals. In the literature, LP seismicity is thought to be originated within the fluid, and therefore to be representative of the pressurization state of the volcano plumbing system. Another model suggests that LP events are caused by slow, quasi-brittle, low stress-drop failure driven by transient upper-edifice deformations. Knowledge of the spatial distribution of LP events is fundamental for better understanding the physical processes occurring in the conduit, as well as for the monitoring and the improvement of eruption forecasting. LP events recorded at Merapi have a spectral content dominated by frequencies between 0.8 and 3 Hz. To locate the source of these events, we installed a seismic antenna composed of 4 broadband CMG-6TD Güralp stations. This network has an aperture of 300 m. It is located on the site of Pasarbubar, between 500 and 800 m from the crater rim. Two multi-parameter stations (seismic, tiltmeter, S-P) located in the same area, equipped with broadband CMG-40T Güralp sensors may also be used to complete the data of the antenna. The source of LP events is located by using different approaches. In the first one, we used a method based on the measurement of the time delays between the early beginnings of LP events for each array receiver. The observed differences of time delays obtained for each pair of receivers are compared to theoretical values calculated from the travel times computed between grid nodes, which are positioned in the structure, and each receiver. In a second approach, we estimate the slowness vector by using MUSIC algorithm applied to 3-components data. From the slowness vector, we deduce the back-azimuth and the incident angle, which give an estimation of LP source depth in the conduit. This work is part of the Domerapi project funded by French Agence Nationale de la Recherche (https

  18. Gene identification and survival prediction with Lp Cox regression and novel similarity measure.

    PubMed

    Liu, Zhenqiu; Jiang, Feng

    2009-01-01

    In this paper, Cox's proportional hazards model with Lp penalty method is developed for simultaneous gene selection and survival prediction. Lp penalty shrinks coefficients and produces some coefficients that are exactly zero, and therefore can be used to identify survival related downstream genes. We also define a novel similarity measure to hunt the regulatory genes that their gene expression changes may be low but they are highly correlated with the selected genes. Experimental results with gene expression data demonstrate that the proposed procedures can be used for identifying important gene clusters that are related to time to death due to cancer and for building parsimonious model for predicting the survival of future patients.

  19. Broadband electric-field-induced LP01 and LP02 second harmonic generation in Xe-filled hollow-core PCF.

    PubMed

    Ménard, Jean-Michel; Köttig, Felix; St J Russell, Philip

    2016-08-15

    Second harmonic (SH) generation with 300 fs pump pulses is reported in a xenon-filled hollow-core photonic crystal fiber (PCF) across which an external bias voltage is applied. Phase-matched intermodal conversion from a pump light in the LP01 mode to SH light in the LP02 mode is achieved at a particular gas pressure. Using periodic electrodes, quasi-phase-matched SH generation into the low-loss LP01 mode is achieved at a different pressure. The low linear dispersion of the gas enables phase-matching over a broad spectral window, resulting in a measured bandwidth of ∼10  nm at high pump energies. A conversion efficiency of ∼18%/mJ is obtained. Gas-filled anti-resonant-reflecting hollow-core PCF uniquely offers pressure-tunable phase-matching, ultra-broadband guidance, and a very high optical damage threshold, which hold great promise for efficient three-wave mixing, especially in difficult-to-access regions of the electromagnetic spectrum. PMID:27519091

  20. Isolated left homonymous hemianopia secondary to a pericatheter cyst-a rare presentation of a ventriculoperitoneal shunt failure.

    PubMed

    Watkins, Jordan D; Lee, Janet; Van Engen, Meagan J; Tibbs, McKenzie L; Ellegala, Dilantha B; Nicholas, Joyce S

    2015-03-01

    A 26-year-old woman developed a left homonymous hemianopia 1 week after placement of a ventriculoperitoneal shunt through a right parieto-occipital approach. Computed tomography demonstrated a parenchymal cyst in the right occipital lobe. After shunt revision, there was concomitant resolution of the cyst and visual field defect over 1 month. The literature is reviewed regarding this unusual complication of ventriculoperitoneal shunt failure. PMID:25426733