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Biomedical subjects

R L Gordon

Publications and source records attributed to R L Gordon.

At least 19 recordsLinked to original sources

Polygenic Associations between Motor Behaviour, Neuromotor Traits, and Active Music Engagement in Four Cohorts.

Phenotypic investigations have shown that actively engaging with music, i.e., playing a musical instrument or singing may be protective of motor decline in aging. For example, music training associated with enhanced sensorimotor skills accompanied by changes in brain structure and function. Although it is possible that the benefits of active music engagement "transfer" to benefits in the motor domain, it is also possible that the genetic architecture of motor behaviour and the motor system structure may influence active music engagement. This study investigated whether polygenic scores (PGS) for five behavioural motor traits, 12 neuromotor structural brain traits, and seven rates of change in brain structure traits trained from existing discovery genome-wide association studies (GWAS) predict active music engagement outcomes in four independent cohorts of unrelated individuals of European ancestry: the Canadian Longitudinal Study on Aging (CLSA; N=22,198), Wisconsin Longitudinal Study (WLS; N=4,605), Vanderbilt's BioVU Repository (BioVU; N=6,150), and Vanderbilt's Online Musicality study (OM; N=1,559). Results were meta-analyzed for each PGS main effect across outcomes and cohorts, revealing that PGS for a faster walking pace was associated with higher amounts of active music engagement. Within CLSA, a higher PGS for walking pace was associated with greater odds of engaging with music. Findings suggest a shared genetic architecture between motor function and active music engagement. Future intervention-based research should consider the genetic underpinnings of motor behavior when evaluating the effects of music engagement on motor function across the lifespan.

BioVU

Using transjugular intrahepatic portosystemic shunts to control variceal bleeding before liver transplantation.

OBJECTIVE: To determine the safety and efficacy of transjugular intrahepatic portosystemic shunts (TIPS) in controlling bleeding from esophageal varices in patients awaiting liver transplantation. DESIGN: Prospective, uncontrolled trial. SETTING: University medical center with an active liver transplant program. PATIENTS: Thirteen patients referred for liver transplantation with either active variceal hemorrhage or recurrent variceal hemorrhage despite sclerotherapy; four patients had been previously treated with surgical portosystemic shunts. INTERVENTION: An intrahepatic portosystemic shunt created via a transjugular approach to the hepatic veins using expandable, flexible metallic stents. MEASUREMENTS: Portal pressures before and after the creation of the shunt, the direction of portal blood flow at differing diameters of the shunts, procedure-related complications, and outcome in terms of survival, liver transplantation, and recurrent variceal bleeding. MAIN RESULTS: The transjugular intrahepatic portosystemic shunt was placed successfully in 13 patients, and bleeding was controlled acutely in all 13. After the procedure, the mean portal pressure decreased from 34 +/- 8.9 cm H2O to 22.4 +/- 5.4 cm H2O (P less than 0.001). No complications were associated with the procedure; however, two patients died of causes unrelated to the procedure. Seven patients subsequently underwent liver transplantation and are doing well, and three patients are being managed conservatively. Bleeding recurred in one patient 102 days after the procedure secondary to shunt occlusion caused by neointimal proliferation. CONCLUSION: Placement of a transjugular intrahepatic portosystemic shunt is apparently safe and effective therapy for variceal hemorrhage in patients referred for liver transplantation.

Catheterization

Nonoperative treatment of enteric fistulas: results in 53 patients.

Fifty-three patients with enterocutaneous fistulas were treated nonoperatively. While most of the fistulas resulted as a complication of surgery, other causes included inflammatory disease, trauma, and malignancy. Fistulas originated from the esophagus (n = 4), stomach (n = 4), duodenum (n = 5), small bowel (n = 27), colonic-small bowel anastomosis (n = 2), colon (n = 10), and Hartmann pouch (n = 1), and included both high-output (n = 29) and low-output (n = 24) types. Nonoperative management resulted in spontaneous fistula closure in 57%. Most of the spontaneous closures (83%) occurred within 2 months of treatment. Spontaneous closure rates were similar for low-output and for high-output fistulas (52% vs 63%), but the treatment duration was longer for high-output than for low-output fistulas (mean treatment duration, 17 days vs 41 days). Colonic fistulas were particularly difficult to manage and closed spontaneously in only 10% of patients (one of 10).

Adult

Transjugular intrahepatic portosystemic shunts: preliminary results in 25 patients.

A retrospective study of transjugular intrahepatic shunts performed between June 1990 and June 1991 is reported. Twelve patients were actively bleeding at the time of the procedure; 12 other patients had had one to five bleeding episodes within the previous 2 weeks, and one patient had massive ascites from Budd-Chiari syndrome. Most patients had severe liver disease: 21 Child's class C, three Child's class B, and one Child's class A. Transjugular intrahepatic shunting was technically successful in all cases. Portal vein pressures were reduced on average from 36 +/- 7 cm H2O to 22 +/- 6 cm H2O. Variceal bleeding ceased after transjugular intrahepatic shunting in all patients who were actively bleeding. Five patients died (30-day mortality, 20%), and eight patients subsequently underwent elective liver transplantation. The transjugular intrahepatic shunts in the 12 other patients have remained patent an average of 5.5 months. Shunt occlusion occurred in three patients at 21, 24, and 102 days, respectively. All three occlusions were successfully reopened with percutaneous techniques, yielding a primary shunt patency of 88% and secondary shunt patency of 100%. Complications included new onset encephalopathy in one patient, which cleared with medical therapy and transient renal failure in one patient. These preliminary data suggest that transjugular intrahepatic shunting is a safe and effective therapy for the short-term treatment of patients with variceal hemorrhage, particularly in patients with severe liver disease awaiting transplantation. The long-term benefit of transjugular intrahepatic shunting awaits further follow-up.

Adolescent

Biliary concentrations of fluconazole in a patient with candidal cholecystitis: case report.

A patient with acute cholecystitis due to Candida albicans and Candida parapsilosis was treated with a percutaneous cholecystostomy and daily intravenous fluconazole. Fluconazole levels in serum and bile were measured by gas chromatography. Fluconazole levels in the bile were equal to those in the blood for the first 8 hours after a dose and were slightly higher than serum levels after that. Bile levels after an oral dose of fluconazole were 15% higher than levels achieved after intravenous administration of the drug. The infection was cured after 2 weeks of treatment. This experience suggests that sufficient fluconazole is excreted in the bile to be effective for treatment of biliary infections due to susceptible yeasts.

Aged

Malignant biliary obstruction: treatment with expandable metallic stents--follow-up of 50 consecutive patients.

A consecutive series of 50 patients with malignant biliary obstruction were treated by means of palliative drainage with a metallic expandable stent. Stent placement was successful in all patients. The patients were followed up prospectively at 2-month intervals over a period of 9-22 months. Forty-one patients (82%) died; nine (18%) are still living. The overall patency and survival rates for the 50 patients were 5.8 months and 7.5 months, respectively. The 30-day mortality rate was 8% (n = 4), the minor complication rate was 18% (n = 9), and the major complication rate was 8% (n = 4). One patient (2%) had intrahepatic arterial bleeding that required embolization, one (2%) had a right subphrenic abscess, and two patients (4%) had transient septic events. Stent occlusion requiring a second intervention occurred in 24% of patients (n = 12). Excellent palliation was achieved in most patients. No stent migration occurred. No great clinical advantages in prolonged patency compared with those of other published series involving the use of plastic stents were demonstrated. Ease of placement and versatility may offset the high cost of the stent.

Aged

Role of parallel transjugular intrahepatic portosystemic shunts in patients with persistent portal hypertension.

Transjugular intrahepatic portosystemic shunts (TIPS) were placed in 93 patients between June 1990 and January 1992 for treatment of variceal hemorrhage. In each case, a Wallstent (Schneider USA, Minneapolis) was used to support the hepatic parenchymal tract between the hepatic and portal veins. Currently, these stents have a maximal diameter of 10 mm. In eight of 93 patients, major portal hypertension persisted after placement of a 10-mm-diameter shunt, manifested by continued rapid variceal filling and elevated portosystemic gradients. A second TIPS was placed parallel to the first in these patients to allow further portal decompression. In two other patients, a second TIPS was placed because the initial shunt functioned suboptimally. The mean postprocedural portosystemic gradient in the patients who received one TIPS was 10.2 mm Hg +/- 3.7. In patients who received two TIPS, the mean postprocedural gradient was 19.1 mm Hg +/- 3.8 after placement of the first TIPS and 12.5 mm Hg +/- 3.5 after placement of the second. Two patients developed their first episode of encephalopathy after placement of two TIPS. The methods and indications for placing two TIPS in this select population are discussed.

Adult

Treatment of pulmonary arteriovenous malformations by therapeutic embolization. Rest and exercise physiology in eight patients.

Pulmonary arteriovenous malformations (AVM) lead to chronic hypoxemia and systemic emboli. These lesions can now be treated by catheter embolization. In order to examine physiologic abnormalities during exercise in AVM patients, and to evaluate functional improvement after therapeutic embolization, eight patients underwent detailed physiologic studies at rest and during exercise before and after therapeutic embolization. Before treatment, six patients noted dyspnea on exertion and three had symptoms suggesting paradoxical embolism. Resting studies showed hypoxemia, abnormally increased shunt fractions, chronic alveolar hyperventilation, mild decreases in diffusing capacity, and abnormal wasted ventilation (VD). During exercise, oxygenation changed little from the resting values but VD increased markedly. Functional impairment was observed in most patients, and was correlated with shunt fraction. Obliteration of the AVM was accomplished by therapeutic embolization with placement of coils or balloons in the feeder vessels. This treatment resulted in immediate relief of dyspnea and improvement in resting PaO2 and shunt fraction. Exercise studies after embolization showed improvement in exercise capacity and gas exchange. However, chronic alveolar hyperventilation and reduced diffusing capacity remained unchanged. In summary, therapeutic embolization effectively reduces the degree of shunting, with improvement in respiratory symptoms, exercise capacity, and gas exchange at rest and during exercise. The abnormally decreased diffusing capacity and increased VD suggest the presence of a diffuse pulmonary vascular abnormality, of which further study is warranted.

Adult

Delayed gallbladder rupture following percutaneous cholecystostomy.

Percutaneous cholecystostomy has become an accepted therapeutic alternative for high-risk patients with acute cholecystitis. However, some authors have cautioned that patients with gallbladder wall necrosis and gangrene may not be effectively treated by means of percutaneous drainage alone. A case is reported in which gallbladder wall necrosis progressed following technically successful percutaneous drainage. Spontaneous gallbladder rupture ensued, necessitating emergent cholecystectomy. Cholecystography 2 weeks following tube placement and 1 week prior to rupture showed a markedly abnormal, irregular gallbladder lumen. The authors suggest that follow-up cholecystography may be a useful tool for evaluating patient response to percutaneous cholecystostomy and for determining subsequent patient management.

Acute Disease

Histopathologic study of transjugular intrahepatic portosystemic shunts.

A detailed histopathologic analysis of intrahepatic portosystemic shunts was performed following liver transplantation in five patients. Gross examination revealed that all stents were patent and unchanged in size, shape, and position from initial placement. Histologic examination at 4 days revealed an irregular luminal surface with liver parenchyma protruding between the stent wires and a single, patchy layer of endothelial cells lining the shunt surface. By 3 weeks, the stent wires were covered by a pseudointima of granulation tissue, and the luminal surface was lined with a contiguous layer of endothelial cells. Excessive pseudointimal proliferation resulted in shunt occlusion at 3 months in one patient whose shunt was subsequently reopened percutaneously.

Female

Malignant biliary obstruction complicated by ascites: transjugular insertion of an expandable metallic endoprosthesis.

Although the transjugular approach has long been used to provide safe access to the liver, it has not been used for placement of stents in biliary obstruction. The recent development of an expandable metallic endoprosthesis now makes this method more feasible. The case of a patient with malignant biliary obstruction complicated by ascites is presented herein. Palliation was achieved with an expandable biliary endoprosthesis placed by the transjugular-hepatic vein approach.

Aged

Percutaneous intrahepatic portosystemic shunt created via a femoral vein approach.

Creation of a percutaneous intrahepatic portosystemic shunt was attempted in a patient with portal hypertension and acute variceal hemorrhage. Abnormal hepatic venous anatomy precluded formation of the shunt with the standard transjugular method. An alternate technique was devised in which a femoral vein approach was used to construct an intrahepatic channel between the inferior right hepatic vein and the right portal vein. The patient stopped bleeding after the procedure and has not rebled during an 8-month follow-up period.

Esophageal and Gastric Varices

Community cholesterol screening. Impact of labeling on participant behavior.

To investigate the effect of screening for an elevated cholesterol level and compliance with follow-up recommendations, we surveyed 375 participants in a free screening program at a shopping mall walk-in clinic. One hundred thirty-nine participants (37%) had desirable (less than 5.17 mmol/L [less than 200 mg/dL]), 135 (36%) had borderline (5.17 to 6.18 mmol/L [200 to 239 mg/dL]), and 101 (27%) had high (greater than 6.18 mmol/L [greater than 239 mg/dL]) cholesterol levels. Persons in the borderline and high categories were instructed to see their physicians within 2 months for confirmation of their levels. Of the 338 (90%) who responded to a follow-up questionnaire at 3 months, 8 (7%) in the desirable, 23 (22%) in the borderline, and 44 (50%) in the high group had been to see physicians concerning their cholesterol levels since the screening. In multiple logistic regression analyses only cholesterol category at time of screening, current use of antihypertensive drugs, history of coronary heart disease, and history of a high cholesterol level were associated with physician follow-up. Our results suggest that labeling persons as being at high rather than borderline risk results in greater physician follow-up.

Cholesterol

Nonoperative management of bile duct stones.

The treatment of choice for most retained bile duct stones is by nonoperative means. If a T-tube is in place, percutaneous techniques via the T-tract are indicated. Percutaneous access via puncture of a Roux-en-Y loop is also practical. In the absence of a T-tube, retrograde endoscopic techniques should be used. Both techniques are very effective and safe. Stones in the intrahepatic and extrahepatic ducts also can be treated nonoperatively. Endoscopic sphincterotomy has a role in the treatment of selected patients with gallstone pancreatitis, acute cholangitis, and choledocholithiasis with in situ gallbladders. In difficult cases, endoscopic and percutaneous techniques are employed in combination.

Bile Duct Diseases

Percutaneous transhepatic portal vein angioplasty and stent placement after liver transplantation: early experience.

In four patients who underwent liver transplantation, portal vein thrombosis was associated with esophageal varices and significant gastrointestinal bleeding. In a fifth liver transplant patient, portal vein stenosis was suspected when evidence of hepatic ischemia was revealed at liver biopsy. Four patients were treated with percutaneous transhepatic portal vein angioplasty. Percutaneous recanalization was precluded by technical factors in the remaining patient. Early in the series, one patient required surgical excision of what proved to be a thick cuff of fibrous tissue and lymph nodes after angioplasty failed to widen the stenosis significantly. Later, a patient with residual stenosis was treated successfully by means of intravascular stent placement. Of the four patients treated, three eventually died secondary to multiple problems unrelated to the percutaneous procedure. This early experience suggests that transhepatic portal vein interventions are feasible in patients who have received liver transplants and may prove useful at least in the early postprocedure period.

Adult

Percutaneous transhepatic placement of biliary endoprostheses: results in 100 consecutive patients.

One hundred patients with malignant biliary obstruction underwent palliative therapy by means of percutaneous transhepatic placement of 114 biliary endoprostheses. All patients were then followed up for at least 18 months or until death. Retrospective evaluation of the 95 patients who died showed an average survival time of 5.0 months. The five remaining patients have survived an average of 29.8 months. During the 1st week after stent insertion, a second manipulation was performed to improve stent function in nine patients. Overall, 14 (12.3%) of the stents became obstructed and six (5.2%) migrated; 86 patients required no further therapy for biliary obstruction or stent malfunction. The 30-day mortality rate was 12%; none of the deaths were directly attributable to a complication of the stent placement procedure.

Biliary Tract Neoplasms

The management of T tube leaks in orthotopic liver transplant recipients with endoscopically placed nasobiliary catheters.

Biliary tract problems remain an important cause of complication following orthotopic hepatic transplantation. We describe 12 liver transplantation patients who developed bile peritonitis secondary to a biliary leak after T tube removal. Each of these patients underwent an urgent ERCP that exhibited leakage outside the T tube tract and nondilated intrahepatic ducts. At the time of the ERCP, a nasobiliary catheter was inserted to divert the bile flow. All of these patients resolved their symptoms and closed their leak. We advocate endoscopic placement of a nasobiliary catheter as first-line therapy for significant T tube tract leaks after liver transplantation.

Adult