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Biomedical subjects

B R Taylor

Publications and source records attributed to B R Taylor.

68 records · Page 4Linked to original sources

Complications after peritoneovenous shunting for ascites.

The results and complications in our first 23 consecutive patients receiving the peritoneovenous shunt for intractiable hepatic ascites are presented. A good initial diuretic effect was obtained in 20 of the 23 patients, with reversal of hepatorenal failure in 3 of 5 patients. The postoperative complication rate was high (74 percent). Infection, coagulopathy and complication of the underlying liver disease contributed to a mortality rate of 26 percent. Late complications were related to the primary liver disease. The 6 month survival rate was 58 percent and the 1 hear survival rate 52 percent with five patients followed up for more than 2 years. Because of the significant morbidity and mortality associated with the peritoneovenous shunt, we recommend it only for patients with massive intractable hepatic ascites whose condition is refractory to maximal medical therapy.

Ascites↗

A prospective randomized trial of the selective distal splenorenal shunt.

Distal splenorenal shunt has been compared in a prospective randomized way with end-to-side portacaval shunt in patients who have survived a major hemorrhage from esophageal varices. The operative mortality was higher after the elective shunt than after the portacaval shunt. However, most of these deaths occurred in the early phases of the study. Postoperative encephalopathy was significantly lower after the selective shunt than after the portacaval shunt. Follow-up studies to date show no significant difference in late survival.

Adult↗

The renal and hemodynamic effects of the peritoneovenous shunt for intractable hepatic ascites.

Fifteen patients with chronic liver disease having a peritoneovenous shunt for chronic intractable ascites were studied prospectively for renal function and hemodynamic changes during balance studies, pre-, peri-, and postoperatively. Shunt insertion caused a rapid redistribution of ascites into the intravascular compartment with hemodilution and significant rises in cardiac output (9 patients) (P less than 0.025) renal blood flow (3 patients) (P less than 0.025), and creatinine clearance (15 patients) (P less than 0.005), and decreases in plasma renin activity (10 patients) and serum aldosterone levels (9 patients) (P less than 0.025). Despite these changes, small repeated doses of furosemide were required to start and maintain a diuresis and natriuresis with sodium excretion rising from 7.2 +/- 4.1 to 174 +/- 44 meq/day (P less than 0.0005) in the 15 patients. At 2 wk postoperatively, the 15 patients had lost a mean of 7.5 kg in weight associated with a persistent improvement in creatinine clearance and a continued natriuresis, 15.9 +/- 7 mEq/day (P less than 0.005), despite no statistically significant change in cardiac output (7 patients) or renal blood flow (4 patients) compared with preoperative levels. This operation is an effective therapy for refractive ascites, but the incidence of potentially fatal complications makes us hesitate to recommend it except for patients resistant to normal conservative measures.

Adult↗

The effect of peritoneovenous shunting on catecholamine metabolism in patients with hepatic ascites.

The elevated catecholamine levels in cirrhotic patients with ascites have been proposed to be due to sympathetic overactivity secondary either to reduced intravascular volume or to an underlying cardiovascular abnormality such as reduced pressor responsiveness. Furthermore, these elevated catecholamine levels have been proposed to be involved in the pathogenesis of salt and water retention. Therefore, the effect of peritoneovenous shunting on the circulating levels and renal excretion of catecholamines were studied in six patients with massive refractive ascites preoperative within the first 8 hr postoperative and by 2 weeks postoperative under metabolic conditions. The recirculation of ascites into the intravascular compartment resulted perioperatively in significant rises in cardiac output (p = 0.001), para-amino-hippurate clearance (p = 0.08), creatinine clearance, diuresis (p = 0.05) and natriuresis (p = 0.06). Systemic blood pressure remained unchanged while systemic vascular resistance decreased (p less than 0.05). Preoperative circulating levels of free catecholamine were highly elevated, and renal vein concentrations were about 25% higher than renal arterial levels. Perioperatively, there was little change in circulating catecholamine levels or distribution of renal blood flow although renal artery and vein concentrations tended to equalize. In contrast by 2 weeks postoperatively, free catecholamine levels had fallen to within the normal ranges: mean norepinephrine from 1,477.6 +/- 194.6 to 395 +/- 62.9 pg per ml (p less than 0.05); epinephrine from 276 +/- 74.2 to 65.7 +/- 15.0 pg per ml (p less than 0.02), and dopamine from 325.6 +/- 175.2 to 47.9 +/- 5.3 pg per ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Experience with radical esophagogastric devascularization procedures (Sugiura) for variceal bleeding outside Japan.

The Sugiura operation has been reported to have low operative mortality, rebleeding, and encephalopathy rates when carried out in a predominantly nonalcoholic Japanese population with good liver function. A literature review of reports of the Sugiura procedure outside Japan reveals a high complication and mortality rate when it is used as an emergency procedure in patients with advanced liver disease, especially in those with alcoholic cirrhosis. Uncontrolled studies report results that differ little from the Japanese series when the operation is confined to good-risk patients in the elective situation. Our experience with the Sugiura operation supports its role in these circumstances, especially in patients with portal vein thrombosis and normal liver function. The only good prospective controlled trial has been carried out in patients with schistosomiasis and suggests that the Sugiura operation is far superior to total shunt and may have a slight advantage over the Warren shunt because of its low incidence of postoperative encephalopathy. More controlled trials are required to establish its role in good- to moderate-risk patients with alcoholic cirrhosis.

Adult↗

Health care system and medical education in Canada. 1. Review of the health care context in a time of change.

Over the past three decades Canada has developed an exemplary system of universal health care. However, current financial constraints threaten to undermine the very foundation of the system that represents Canada's respect for social justice. The first of these two articles (Part 1) discusses the unique characteristics of the system, a comparative view of universal health care systems, the reaction of the medical profession to governmental control, and finally the funding and manpower shortages that are compelling a review of the values and organization that have sustained the system thus far. The second article (Part 2) reviews the organization and funding of medical education and the impact of some critical changes in the health care system on postgraduate medical education. Issues related to new licensure and certification requirements, changing population demographics and approaches to health care delivery, manpower needs, and the attitude and expectations of the public are discussed.

Canada↗

Health care system and medical education in Canada. 2. Impact of changes in the health care system on medical education.

Over the past three decades Canada has developed an exemplary system of universal health care. However, current financial constraints threaten to undermine the very foundation of the system that represents Canada's respect for social justice. The first of these two articles (Part 1) discusses the unique characteristics of the system, a comparative view of universal health care systems, the reaction of the medical profession to governmental control, and finally the funding and manpower shortages that are compelling a review of the values and organization that have sustained the system thus far. The second article (Part 2) reviews the organization and funding of medical education and the impact of some critical changes in the health care system on postgraduate medical education. Issues related to new licensure and certification requirements, changing population demographics and approaches to health care delivery, manpower needs, and the attitude and expectations of the public are discussed.

Canada↗

The hippurate ratio as an indicator of functional hepatic reserve for resection of hepatocellular carcinoma in cirrhotic patients.

Predicting the ability of the cirrhotic liver to withstand resection remains a challenge for the surgeon. This study evaluates the use of the hippurate ratio, a novel assessment of glycine conjugation of para-aminobenzoic acid by the liver, as a preoperative indicator of functional hepatic reserve. Between 1998 and 2000, sixty-one cirrhotic patients were prospectively assessed for hepatic resection using the hippurate ratio, indocyanine green retention at 15 minutes (ICG R-15), and other standard measures of liver function. Twenty-six patients were excluded as candidates for resection on the basis of inadequate functional hepatic reserve. Patients excluded from resection had significantly higher ICG R-15 values (29% +/- 9% vs. 16% +/- 12%, P = 0.001), higher Child-Pugh scores (5.9 +/- 0.9 vs. 5.3 +/- 0.4, P = 0.01), and lower hippurate ratios (30% +/- 14% vs. 45% +/- 15%, P = 0.005). There was a significant correlation between the hippurate ratio and ICG R-15. Other indicators of liver function such as factor V, factor VII, albumin, bilirubin, prothrombin time, and transaminases were no different between patients who did and those who did not undergo resection. Of the 35 patients resected, there were seven (20%) who developed varying degrees of liver failure with three perioperative deaths (8.5%). Patients who had some degree of liver failure had significantly lower hippurate ratios than patients who had no liver failure (29% +/- 10% vs. 48% +/- 14%, P = 0.002). There was no difference in ICG R-15 values between patients who had liver failure and those who did not. The hippurate ratio offers information on hepatocellular reserve that is not provided by other measures of liver function and may allow better selection of cirrhotic patients for liver resection.

4-Aminobenzoic Acid↗

Aggressive surgical management of fibrolamellar hepatocellular carcinoma.

Fibrolamellar hepatocellular carcinoma (FLHC) is recognized as a distinct clinicopathologic variant of hepatocellular carcinoma. Ten consecutive patients with FLHC undergoing operative management at our institution were reviewed. At the initial presentation seven patients had stage II disease (pT2N0M0), whereas three patients were in stage III (pT2N0M0 or pT3N0M0). Initial procedures included formal right or left hepatectomy in four patients, right or left trisegmentectomy in two patients, left lateral segmentectomy or nonanatomic resection in three patients, and in one patient considered for liver transplantation, only exploration with biopsy of positive nodes was performed. Four stage II patients required a second procedure for resection of recurrent disease from 8 months to 6 years after the initial resection and one patient required a third procedure after 13 years. Reoperations included hepatic re-resection, resection of extrahepatic disease, and liver transplantation. Overall 5- and 10-year Kaplan-Meier survival was 70%. There were no deaths among stage II patients (follow-up 96 to 180 months). All stage III patients (i.e., lymph node involvement, vascular invasion, or multiple tumors) died within 5 years. Patients with stage II disease had better survival than patients with stage III disease (P = 0.011, log-rank test). Aggressive treatment of FLHC including reoperation and liver transplantation is justified, especially in patients with stage II disease.

Adult↗

Surgical management of hepatocellular carcinoma: resection or transplantation?

Liver resection or transplantation offers the best opportunity for cure of hepatocellular carcinoma (HCC). To determine the relative roles for resection and transplantation and to evaluate the patient and tumor characteristics that might predict survival, the records of 125 patients treated for nonfibrolamellar HCC at The Toronto Hospital between 1981 and 1996 were reviewed. No adjuvant chemotherapy or antiviral protocols were used. Resection was the first operation in 67 patients; one underwent re-resection. Sixty patients underwent transplantation including two who had previously had a resection; 40 had known or suspected HCC and 20 had incidental tumors identified in the explanted liver. The incidence of cirrhosis was 49% for resection and 88% for transplantation. The incidence of hepatitis B virus (HBV) was 58% and 33%, respectively. The operative mortality rate for resection was 4.4% (9.4% in cirrhotic and 0 in noncirrhotic patients) and 13.3% for transplantation. The 5-year cumulative recurrence rate was 55% following resection and 20% following transplantation (P <0.001). The 5-year Kaplan-Meier survival rates were 38% for resection and 45% for transplantation-60% for transplanted HBV-negative and 17% for HBV-positive patients (P <0.001). After resection, recurrent HCC accounted for 86% of deaths, whereas recurrent HBV was responsible for 42% of deaths after transplantation. By univariate analysis, following resection, vascular invasion, advanced stage, multiple tumors, and lack of a capsule were predictive of survival; cirrhosis, HBV, age, tumor size, number, and grade were not. By multivariate analysis, only vascular invasion was predictive for resection and HBV for transplantation. Resection and transplantation are complementary methods of treating HCC. With the current organ shortage, resection should be considered first-line treatment. HBV-positive patients with HCC should only undergo transplantation in combination with effective antiviral therapy.

Age Factors↗

Geographical overlap of two mitochondrial genomes in Spanish honeybees (Apis mellifera iberica).

Restriction enzyme cleavage maps of mitochondrial DNA from the Spanish honeybee, Apis mellifera iberica (Hymenoptera: Apidae), were compared with those from the European subspecies A. m. mellifera, A. m. ligustica, and A. m. carnica, and the African subspecies A. m. intermissa and A. m. scutellata. The mitochondrial DNA (mtDNA) of the two African subspecies can be distinguished by restriction fragment polymorphisms revealed by Hinf I digests. Two distinct mtDNA types were found among Spanish honeybees: a west European mellifera-like type, which predominates in the north of Spain, and an African intermissa-like type, which predominates in the south. Spain appears to be a region of contact and hybridization between the two subspecies A. m. intermissa and A. m. mellifera, which respectively represent African and west European honeybee lineages. This natural boundary between European and African honeybee populations in the Old World may provide a model for predicting the eventual outcome of the colonization of North America by introduced African honeybees.

Africa↗