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Biomedical subjects

R H Bell

Publications and source records attributed to R H Bell.

At least 73 records · Page 4Linked to original sources
PubMed1987

Early total parenteral nutrition in acute pancreatitis: lack of beneficial effects.

To determine the effect of early aggressive parenteral support in pancreatitis, 54 patients with acute pancreatitis were randomized to receive either conventional therapy (control group) or conventional therapy plus the institution of total parenteral nutrition within 24 hours. The two groups were similar demographically. The total parenteral nutrition group had a significantly higher rate of catheter-related sepsis than did an additional group of contemporaneous patients without pancreatitis who received total parental nutrition (10.5 percent and 1.47 percent, respectively; p less than 0.01). There was no advantage to the use of early total parenteral nutrition; that is, there was no difference in the number of days to oral intake, total hospital stay, or number of complications of pancreatitis. Patients with zero or one Ranson's criterion on admission were more likely to be eating by the seventh hospital day than were those with two or more Ranson's criteria (80 percent and 54 percent, respectively; p less than 0.05). The early institution of total parenteral nutrition in patients with acute pancreatitis did not appear to improve the outcome. Its use should be limited to prolonged periods of no oral intake or treatment of a specific complication, such as a pseudocyst.

Acute Disease↗
PubMed1987

Pancreatic carcinogenicity of N-nitrosobis(2-oxopropyl)-amine in diabetic and non-diabetic Chinese hamsters.

To examine the role of diabetes in pancreatic cancer, 4 groups of Chinese hamsters--2 from genetically diabetic and 2 from non-diabetic lines--were treated with N-nitrosobis(2-oxo-propyl)amine (BOP) at different dose levels and intervals. In one group (referred to as the VA group), BOP was given weekly at a 5 mg/kg body wt. level for 18 or 23 weeks, whereas the other group (the EP group) received a weekly dose of 2.5 mg/kg body wt. for life. Except for diet and experimental design, all other laboratory conditions were similar in the two institutions. No VA hamster developed tumors. Three of 22 non-diabetic EP hamsters (but none of the diabetic hamsters) developed pancreatic hyperplastic and neoplastic lesions, comprising ductular cell adenomas (3 hamsters), carcinoma in situ (1 hamster), a well-differentiated adenocarcinoma (1 hamster), and a poorly differentiated adenocarcinoma (1 hamster) with regional lymph node metastases. In addition, over 50% of the EP hamsters had neoplasms for which the incidences and morphology did not vary between diabetic and non-diabetic groups or between the sexes. These were primarily of the liver (cholangiomas), lungs (adenomas) and skin (trichoepitheliomas, squamous cell carcinomas). The differing carcinogenic response of the two hamster groups to BOP apparently is not related to the total BOP dose, but rather to other factors, including the length of observation time.

Animals↗
PubMed1987

Cytokeratin antigen in BOP-induced pancreatic tumors--implications for histogenesis.

Pancreatic carcinoma induced in the Syrian hamster by the carcinogen N-nitrosobis(2-oxopropyl)amine (BOP) is of interest because of the ductal/ductular morphology of the tumors, which resembles human pancreatic cancer. However, whether hamster tumors arise from pre-existing ductal epithelium or from acinar cells has not yet been determined. The present study shows that a monoclonal antiserum to cytokeratin (an epithelial marker), when applied to normal hamster pancreas sections, stained centroacinar, ductular and ductal epithelium but did not stain acinar cells. We therefore examined pancreatic tissue from hamsters with benign and malignant neoplasms induced by BOP. The antiserum strongly stained the cells of all BOP-induced lesions (cysts, pseudoductules, hyperplasia, dysplasia and carcinomas). No acinar cell staining was observed in BOP-treated pancreas. These findings support the hypothesis that BOP-induced neoplasms arise from ductal epithelium and not from acinar cells.

Adenocarcinoma↗
PubMed1986

Ex-vivo isolated perfusion of the pancreas in the Syrian golden hamster.

The technique of ex-vivo isolated pancreatic perfusion has been a valuable method for investigation of the physiology of the exocrine and endocrine pancreas. We have adapted the technique of isolated pancreatic perfusion for use in the Syrian golden hamster, an animal used widely in studies of pancreatic carcinogenesis. The technique involves surgical harvest of the pancreas with its aortic and portal venous blood supply intact and perfusion of the pancreas with a modified Krebs buffer at 37 degrees C. Physiological function of the perfused pancreas system was examined in 27 Syrian hamsters. In tests of endocrine function, the perfused pancreas responded by increasing insulin secretion within 1 min of elevating perfusate glucose concentration, and also secreted insulin promptly in response to 10 mM arginine. In exocrine studies, the flow of pancreatic juice was stimulated by the addition of 0.8 X 10(-9) M secretin to the perfusate, and amylase output was significantly increased by the addition of 0.2 X 10(-9) M cholecystokinin (CCK-8). The ex-vivo isolated perfused pancreas in the hamster thus appears to respond appropriately to physiological stimuli and is a valuable additional tool for studies of the hamster pancreas.

Animals↗
PubMed1986

Long-term survival after emergency portacaval shunting for bleeding varices in patients with alcoholic cirrhosis.

Since 1963, a prospective evaluation of the emergency portacaval shunt procedure has been conducted in 264 unselected patients with cirrhosis and bleeding varices who underwent operation within 8 hours of admission to the emergency department. Of 153 patients who underwent operation 10 or more years ago, 45 (29 percent) have survived from 10 to 22 years and their current status is known. On admission, 40 percent of the long-term survivors had jaundice, 44 percent had ascites, 13 percent had encephalopathy (with an additional 9 percent with a history of encephalopathy), 29 percent had severe muscle wasting, and 82 percent had a hyperdynamic state. There were 9 Child's class A patients, 33 Child's class B patients, and 3 Child's class C patients. At operation, all patients had portal hypertension which was reduced by the shunt to a mean corrected free portal pressure of 18 mm saline solution. The emergency portacaval shunt procedure permanently controlled variceal bleeding. None of the patients bled again from varices, and the shunt remained patent throughout life in every patient. Encephalopathy did not affect 91 percent of the patients, but was a recurrent problem in 9 percent, usually related to the use of alcohol. Lifelong abstinence from alcohol occurred in 58 percent of the long-term survivors, but 11 percent resumed regular drinking and 31 percent consumed alcohol occasionally. Liver function declined compared with preoperative function in only 18 percent of the patients, almost always because of alcohol use. Ten years after operation, 73 percent of the patients were in excellent or good condition, and 68 percent were gainfully employed or engaged in full-time housework. Comparison of the 10 to 22 year survivors with our early group of 180 patients reported previously and our recent group of 84 patients showed no significant differences in preoperative or operative data. The single factor that appeared to influence long-term survival was resumption of regular use of alcohol. We conclude that the emergency portacaval shunt procedure, by preventing hemorrhage from varices, results in prolonged survival and an acceptable quality of life for a substantial number of patients with advanced alcoholic cirrhosis.

Adult↗
PubMed1986

Pancreatic insulin secretion in exocrine pancreatic cancer.

Adenocarcinoma of the exocrine pancreas in man is associated with a high incidence of diabetes mellitus. Hyperglycemia in humans with pancreatic cancer is presumed to be caused by destruction of islets of Langerhans with a resultant impairment in pancreatic insulin secretion. This hypothesis was tested in an animal model of exocrine pancreatic cancer. Carcinoma of the pancreas was induced in male Syrian golden hamsters by weekly injection of N-nitrosobis(2-oxopropyl)amine. Using an ex vivo isolated perfused pancreas preparation, the capacity of cancer-bearing pancreata to secrete insulin in response to glucose and arginine was compared to normal animals of the same age. Animals with pancreatic cancer demonstrated a normal insulin secretory response to both glucose and arginine. Thus the hypothesis that exocrine pancreatic cancer causes diabetes by directly impairing insulin release must be questioned and alternative explanations for the association of diabetes and pancreatic cancer should be sought.

Adenocarcinoma↗
PubMed1986

Anterior dislocation of the shoulder in the older patient.

A significant number of rotator cuff defects are brought to light following a first-time dislocation in older patients. Recurrence in this group of patients is low; however, standard anterior repairs may be employed effectively in such situations. Neurologic and vascular injuries, although infrequent, should be carefully ruled out as accompanying the initial injury. Knowledge of these facts will allow a better appreciation of the pathology associated with the anterior dislocation in the older patient. From this, more confident recommendations may be made regarding management of these difficult problems.

Adult↗
PubMed1986

Stress fracture of the distal ulna. A case report.

A stress fracture occurred in a 19-year-old competitive tennis player. Stress fractures are one of the more common problems occurring in vigorous sports. Prevalence, location, and treatment have been well documented, especially in the lower extremity. Stress fractures of the upper extremities are uncommon.

Adult↗
PubMed1986

The three-part fracture of the proximal part of the humerus. Operative treatment.

A retrospective review of the cases of fifteen patients with a three-part fracture of the proximal part of the humerus is presented. Fourteen of the fractures were treated with tension-band wiring and one, with an AO buttress plate. The patients were evaluated for pain, range of motion, strength, and function of the involved shoulder and the radiographic result at an average of fifty-four months after the injury. At follow-up, the shoulders had an average of 126 degrees of active elevation, 29 degrees of active external rotation, 81 degrees of active abduction, and internal rotation to the second lumbar vertebra. The only early complication was failure of fixation in the patient who had been treated with a buttress plate. In two patients, radiographic evidence of avascular necrosis of the humeral head later developed, and one of them required revision to a hemiarthroplasty. In conclusion, we recommend operative treatment for the healthy, active individual who has a three-part fracture of the proximal part of the humerus. We found that the best results with these difficult fractures are obtained using tension-band wiring.

Aged↗
PubMed1985

Changing patterns of gastrointestinal bleeding.

This study, a retrospective analysis of 351 patients with acute gastrointestinal (GI) hemorrhage, was undertaken to define patterns of disease and age-related operative and mortality rates and to determine changes over time related to changes in management. One third (116 patients) of the admissions had bleeding esophageal varices. Upper GI hemorrhage accounted for 85% (N = 200) and lower GI hemorrhage for 15% (N = 35). Emergency surgical intervention was required in 90 patients (38%), 40% of the upper and 29% of the lower GI hemorrhage patients. Benign ulcer disease accounted for 86% of the cases requiring emergency surgery and was treated with vagotomy and drainage and/or oversewing. Lower GI bleeding is seen in older patients; it has a lower operative intervention rate and a higher mortality. Stress bleeding as a surgical lesion has disappeared since 1979. A more assertive policy for surgical intervention has decreased operative mortality for all age groups. Bleeding duodenal ulcers are decreasing in incidence while gastric lesions appear to be increasing. These population-specific patterns, different from earlier periods, may have implications for training and patient management decisions.

Acute Disease↗
PubMed1984

Outcome in cirrhotic patients with acute alcoholic hepatitis after emergency portacaval shunt for bleeding esophageal varices.

Operative liver biopsy findings were reviewed in 164 consecutive, unselected patients with alcoholic cirrhosis who had bleeding from esophageal varices and underwent emergency portacaval shunt. The survival rate up to 10 years in 49 patients with acute alcoholic hepatitis and alcoholic cirrhosis was not significantly different from that of patients with alcoholic cirrhosis alone. The two groups of patients were compared with respect to 35 other preoperative clinical and laboratory variables, and no other difference between the groups was found that obscured an adverse effect of acute alcoholic hepatitis on survival. We have concluded that acute alcoholic hepatitis and the presence of Mallory bodies in the liver are not a contraindication to portacaval shunt and that there is currently no demonstrated role for preoperative liver biopsy in the evaluation of patients with alcoholic cirrhosis and bleeding esophageal varices.

Acute Disease↗
PubMed1984

Streptozotocin-induced liver tumors in the Syrian hamster.

Streptozotocin was administered in a dose of 50 mg/kg body weight intraperitoneally on three consecutive days to 35 8-week old male Syrian golden hamsters. At sacrifice 16-36 weeks later, macroscopic liver tumors had developed in 27 of 29 surviving animals. The majority of animals had multiple hepatic nodules. Some tumors were already large (greater than 1 cm) 16 weeks after streptozotocin. By histologic criteria, five animals (17%) had hepatocellular carcinoma, 23 (79%) had adenomas with varying degrees of atypia, and one (4%) had a normal liver. No metastases to organs outside the liver were noted. No other primary tumors were observed. Sixteen of 29 animals had ascites. Twenty-five age-matched untreated animals showed no evidence of liver tumors. Although sporadic liver tumors due to streptozotocin have been reported in rats and mice, the high incidence of tumors and short latency period to tumor induction seem to be unique to the Syrian hamster. The development of liver carcinoma without the necessity for long-term administration of the carcinogen and without adjunctive procedures such as partial hepatectomy represents a potential improvement over other animal models of hepatic neoplasia.

Animals↗
PubMed1983

Streptozotocin prevents development of nitrosamine-induced pancreatic cancer in the Syrian hamster.

Administration of the nitrosamine carcinogen N-nitroso-bis (2-oxopropyl) amine (BOP) by subcutaneous injection (5 mg/kg/week) led to the development of invasive pancreatic ductular adenocarcinoma in 100% of normal Syrian hamsters by 24 weeks. Pretreatment of a second group of hamsters with the beta-cell toxin streptozotocin in a diabetogenic dose (50 mg/kg i.p. X 3) completely prevented the development of pancreatic cancer when BOP was subsequently administered. The mechanism of blockade by streptozotocin is unknown. This study suggests the potential importance of the endocrine pancreas in exocrine pancreatic carcinogenesis.

Adenocarcinoma↗
PubMed1982

Correlation of hepatic and portal wedged venography and manometry with histology in alcoholic cirrhosis and periportal fibrosis.

Histologic, manometric, and direct magnification venographic studies of four patients with portal fibrosis and 10 patients with alcoholic cirrhosis were compared before and for variable periods after portacaval shunt procedures. Unique to this investigation was the availability of postoperative wedged portal vein manometry and venography. In periportal fibrosis (presinusoidal obstruction), portal studies demonstrated portal venular atrophy and occlusions, with egress of contrast material from hepatic sinusoids via hepatic veins; hepatic studies were near normal. The reverse was observed in patients with cirrhosis (postsinusoidal obstruction). The degree of elevation of portal vein pressures did not enable clear discrimination of pre- and postsinusoidal obstruction. Results support classical concepts of pre-and postsinusoidal obstructive disease and confirm the utility of wedge hepatic and portal venography in differentiating these two entities.

Blood Pressure↗
PubMed1981

Prospective study of portasystemic encephalopathy after emergency portacaval shunt for bleeding varices.

A prospective study of the development of encephalopathy was undertaken in 180 patients undergoing emergency portacaval shunt for bleeding esophageal varices between 1963 and 1978. The incidence of preoperative encephalopathy was 32 percent. Postoperatively, encephalopathy developed in 31.5 percent of 95 survivors and was severe in 7 percent of those survivors. Encephalopathy developed in most patients in the first and second follow-up years; in 10 year survivors, encephalopathy was virtually absent. Encephalopathy was more likely to occur in patients with encephalopathy at the time of shunt and in those who returned to alcoholism after shunt. Most encephalopathic episodes were precipitated by dietary indiscretion, often associated with alcoholism. Careful follow-up with attention to dietary compliance and abstinence from alcohol should make the risk of encephalopathy acceptable in relation to the unquestionable benefits of portacaval shunt in reducing the risk of variceal hemorrhage.

Alcoholism↗