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Biomedical subjects

R C Merrell

Publications and source records attributed to R C Merrell.

At least 73 records · Page 4Linked to original sources
PubMed1984

Mucormycosis in patients with multiple-organ failure.

Mucormycosis in two patients with multiple-organ failure appeared as a cutaneous lesion and spread rapidly. In the first case, wet mounts and potassium hydroxide preparations were unhelpful, but a punch biopsy specimen established the diagnosis. Prompt and extensive debridement and amphotericin B administration arrested the infection. In the second case, virulent progression of the lesion occurred despite limited amputation, debridement, transfer factor, and amphotericin B, but finally responded to further amputation. Diagnosis was made by histologic examination of infected tissue. Both patients shared the following predisposing factors: sepsis, low blood flow, acidosis, multiple-organ failure, and multiple-antibiotic therapy. Although the mucormycosis was controlled, as confirmed in the first case at autopsy and in the second case by clear margins following reamputation, the outcome was fatal in both cases due to other features of multiple-organ failure.

Adult↗
PubMed1984

Total pancreatectomy in dogs.

Total pancreatectomy in dogs has been an important laboratory maneuver for studies of the apancreatic state and transplantation. The shared blood supply of the pancreas and duodenum has been difficult to address surgically in a way which would preserve the duodenum. A duodenal branch of the gastroduodenal artery has been identified which can support the duodenum when the pancreaticoduodenal arcade is resected. Preservation of this artery in 80 dogs permitted complete pancreatectomy with minimal blood loss and allowed resection of the pancreaticoduodenal vessels. Preservation of the blood supply to the pancreas until the very end of the procedure was rewarded by excellent viability of the tissue. A few technical considerations make this a rather simple procedure which is easily taught. The postoperative management of apancreatic animals is greatly facilitated by utilizing this minimally traumatic procedure which has negligible blood loss.

Animals↗
PubMed1984

Epidural administration of morphine postoperatively for morbidly obese patients.

Two groups of morbidly obese patients undergoing a gastric stapling procedure were compared. Patients in group I received 5 mg of morphine through a lumbar epidural catheter immediately after the surgical procedure while group II patients were treated conventionally with parenterally administered morphine. In group I less narcotics were needed and patients were able to walk earlier than in group II. Length of hospital stay, time to removal of the nasogastric tube and postoperative pulmonary function were not significantly different between groups. Two patients in group I and one patient in group II had generalized pruritus, and in one study patient bradypnea developed in association with the epidural administration of morphine. It is concluded that morbidly obese patients can benefit from epidurally administered morphine and that this form of therapy has a role in the management of these patients.

Adult↗
PubMed1983

Spontaneous hepatic hemorrhage during pregnancy.

Spontaneous rupture of the liver during pregnancy seems to represent an extreme vascular complication of toxemia. The very high mortality rate has generally been attributable to uncontrolled hemorrhage. However, control of the hemorrhage may not be sufficient to achieve recovery. Hepatic dysfunction may proceed to necrosis associated with multiple organ failure, even after successful hemostasis. Although ligation of the hepatic artery has been successful in controlling hemorrhage in hepatic trauma, this maneuver may contribute to injury in patients with this lesion in whom there is a preexisting hepatic abnormality. In this brief review, the relationship of the underlying pathology to a variety of therapeutic measures in the context of a catastrophic complication of pregnancy are discussed.

Adult↗
PubMed1983

Islet recovery in chronic pancreatitis.

Chronic pancreatitis ablates a large majority of the acinar tissue which otherwise is a troublesome contaminant in preparing islet cells from higher mammals. Chronic pancreatitis was induced by dividing all pancreatic attachments to the duodenum, including major and minor ducts, in six dogs. After 10 weeks, biopsy of the pancreas showed marked acinar cell atrophy and fibrosis with preservation and even proliferation of islet cells. Intravenous glucose tolerance testing revealed only a minor decrease in K value from 3.4 +/- 1.0 to 2.1 +/- 0.4 during 10 weeks. All dogs then underwent total pancreatectomy and islet autotransplantation. The pancreas was dispersed to a cell suspension by perfusing the pancreatic ducts with collagenase until tissue integrity failed. The digested tissue was then chopped, dissociated by shaking, and filtered. The average cell yield from the pancreas was 7.6 X 10(7) cells of which greater than 95% were islet cells. Acid alcohol-extracted insulin values suggested an average 7% recovery of insulin content and essentially complete elimination of amylase content was demonstrated.

Amylases↗
PubMed1982

Lateral thoracotomy and one-lung anesthesia in patients with morbid obesity.

Between May, 1980, and October, 1981, 22 morbidly obese patients ranging in weight from 93.4 to 236.8 kg (average, 145.2 kg) underwent transthoracic gastric stapling. Fourteen of these operations were performed using endobronchial intubation and selective collapse of the left lung to facilitate surgical exposure. The patients were compared with 22 consecutive patients treated by trans-abdominal gastric stapling during the same period. None of the 44 patients had evidence of chronic alveolar hypoventilation (pickwickian syndrome). In terms of operating time, blood loss, duration of intubation, and hospital stay, the two groups did not differ significantly. Despite marked shunting during one-lung ventilation, satisfactory arterial oxygen tension (PaO2) could be demonstrated on 100% oxygen for all thoracotomy patients (PaO2 range, 67 to 230 torr; mean, 132.3 torr). In fact, except for a lower PaO2 during one-lung anesthesia, the thoracotomy patients were indistinguishable from the laparotomy patients in terms of perioperative respiratory function. Pain, sedation, and positioning led to significant decreases in vital capacity and one-second forced expiratory volume in both groups on the first post-operative day, and in the thoracotomy group on the second day. There were only two wound infections in the thoracotomy group, as opposed to six infections with two dehiscences in the laparotomy group. It is concluded that lateral thoracotomy with or without one-lung anesthesia can be performed safely in massively obese patients--at least in those without preexisting alveolar hypoventilation syndrome.

Adult↗
PubMed1981

Pseudoxanthoma elasticum and polyposis coli: a novel co-mutation.

Pseudoxanthoma elasticum and polyposis coli are inherited conditions not, to our knowledge, previously reported to coexist. The spontaneous appearance of both conditions in a 62-year-old woman may represent a novel mutation. The defective cell in both pseudoxanthoma and some of the extracolonic manifestations of Gardner's syndrome is the fibroblast; therefore, this case may represent a unique variation of Gardner's syndrome.

Colonic Neoplasms↗
PubMed1981

Preparation of viable islet cells from dogs by a new method.

A new method for the preparation of viable islet cells from the normal dog pancreas is described, based on the perfusion of the pancreatic duct with collagenase. Exposure of the acinar tissue to the highest concentrations of collagenase results in improved islet yield with decreased acinar contamination. After the selective digestion of the gland by ductal perfusion, mechanical dissociation liberates single cells and clumps. Analysis of the procedure by insulin yield and amylase attrition indicates a 57% B-cell recovery and a sixfold enrichment in B-cell concentration. The cells have been transplanted as autografts into dogs after pancreatectomy. In 5 of 7 transplanted dogs, normoglycemia was achieved postoperatively.

Animals↗
PubMed1980

Isolating the elusive islet.

The lack of a technique that allows mass isolation of intact, viable human islets is part of the reason that islet transplantation has not become available to the human diabetic. This report outlines the history of islet isolation and presents two new technical modifications that have been developed in the dog. Many of the current problems in islet isolation are presented, including the difficulty in obtaining enough human pancreatic tissue with minimal warm-ischemia time; inadequate distention of the pancreas to provide sufficient disruption for maximal enzymatic reaction to release intact islets; inefficient chopping methods; the use of collagenase of variable composition; different digestion methods for obtaining isolated islets; and inefficient methods for separating and purifying the islets from the ductal, acinar, and fibrous components. The first new modification involves distention of the dog pancreas through the venous system of the gland rather than the ductal system. This results in improved intralobular disruption, which improved the yield of isolated dog islets by permitting more efficient collagenase digestion. The second new modification eliminates the concept of isolating intact islets: the dog pancreas is digested by trypsin to a single-cell preparation that is partially purified by Ficoll gradients; further purification of the endocrine cells results from selective aggregation using rotational culture. This process produces pseudoislets that contain all the islet cell types and can be kept in culture for up to 4 wk, releasing their hormones in response to appropriate stimuli. These modifications may assist in the struggle to isolate the elusive human islet for safe and effective islet transplantation in the diabetic patient.

Animals↗