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Biomedical subjects

R E Miller

Publications and source records attributed to R E Miller.

At least 145 records · Page 8Linked to original sources
PubMed1986

Glyburide action in cultured 3T3-L1 adipocytes.

During adipocyte differentiation of 3T3-L1 cells, glyburide increased the specific activity (mU/mg protein) of glycerol-3-P dehydrogenase (by at least 14-fold) and glutamine synthetase (by 5-fold). The glyburide-mediated increases in enzyme activities were greater in the presence than in the absence of insulin. Our data indicate that glyburide either potentiates or mimics the actions of insulin to increase the activity of glycerol-3-P dehydrogenase during adipocyte differentiation of cultured 3T3-L1 cells.

Adipose Tissue↗
PubMed1986

Hormonal regulation of amino acid uptake by cultured 3T3-L1 adipocytes.

Incubation of the adipocytes for 20 hours with insulin or with Bt2cAMP plus the theophylline stimulated adipocyte uptake of AIB and MeAIB but did not stimulate the uptake of glutamine or cycloleucine. MeAIB uptake by both 3T3-L1 preadipocytes and 3T3-C2 cells was relatively unresponsive to insulin. However, MeAIB uptake by 3T3-C2 cells was stimulated by treatment with Bt2cAMP plus theophylline. Incubation of 3T3 adipocytes for 60 min with insulin yielded maximal stimulation of 2-deoxyglucose uptake but no stimulation of the uptake of AIB, MeAIB or glutamine. Responsiveness of transport to Bt2cAMP does not appear to require adipocyte differentiation. By contrast, adipocyte differentiation may be required for the development of the insulin-responsive transport systems.

Amino Acids↗
PubMed1986

Monoclonal antibody-defined phenotypes of regional lymph node and peripheral blood lymphocyte subpopulations in early breast cancer.

Lymphocyte subset phenotypes in peripheral blood and axillary lymph node cell isolated from 28 patients undergoing surgery for breast cancer were determined by two-color immunofluorescence with monoclonal antibodies and flow cytometric analysis. Lymphocyte subpopulation proportions were determined with combinations of monoclonal antibodies directed against the Leu 2, Leu 3, Leu 7, Leu 8, Leu 11, Leu 12, Leu 15, Leu M3, and HLA-DR surface markers. Patients were staged according to the postsurgical-pathological modification of the Tumor-Node-Metastases staging system, for analysis of tissue source (lymph node versus peripheral blood) and stage of disease as factors influencing lymphocyte subset size. Activated Leu 2+DR+ and Leu 3+DR+T-cells were elevated in stage 2 carcinoma compared to Stage 1. Elevation of Leu 2+8+ circulating T-cells and a reciprocal depression of Leu 2+8- T-cells were also seen in Stage 2 patients when compared to Stage 1. Total T-cells, B-cells, Leu 2+, and Leu 3+ T-cell subsets and natural killer phenotypes defined by Leu 7 and Leu 11 were unchanged in the peripheral blood of Stages 1 and 2 breast cancer. Regional lymph nodes from Stage 1 were found to contain a high frequency of Leu 3+ cells which dropped significantly in Stage 2 patients; this was found to be numerically due to a sharp decrease in the Leu 3+8- subpopulation in Stage 2 patients. Elevated B-cells (Leu 12+), activated T-cells (Leu 2+DR+ and Leu 3+DR+), total Leu 2+ cells, and Leu 7-11+ natural killer cells were demonstrated in Stage 2 lymph nodes when compared to Stage 1. Generally, no differences in subpopulations were seen when level 1 (low axillary) lymph node cells were compared to level 3 (high axillary) lymph node cells at each stage of the disease. These findings demonstrate substantial differences in the profile of lymphocyte phenotypes between Stage 1 and Stage 2 breast carcinoma, especially in the ipsilateral regional nodes. The findings presented in this study suggest that changes in local-regional immunocompetent cell subsets may be related to metastasis of tumor to the regional nodes and progression of disease without being fully reflected in the systemic circulation.

Analysis of Variance↗
PubMed1986

Acute intravascular hemolytic anemia in the black rhinoceros: hematologic and immunohematologic observations.

To investigate the syndrome of acute intravascular hemolytic anemia in the black rhinoceros (Diceros bicornis), laboratory techniques used in the differential diagnosis of hemolytic anemias were performed on blood samples from 6 black rhinoceroses: 3 nonrelated healthy rhinoceroses, 1 rhinoceros with iron deficiency anemia, and 2 rhinoceroses with intravascular hemolysis. Osmotic fragility, erythrocyte membrane protein composition, hemoglobin electrophoresis, and hemoglobin stability did not distinguish between healthy and affected (anemia or hemolysis) rhinoceroses. Polyclonal antiglobulin reagents were prepared in rabbits, using whole rhinoceros serum and purified rhinoceros immunoglobulin G. These reagents were nonreactive against erythrocytes of the healthy and iron-deficient rhinoceroses. Reactions with RBC from the rhinoceros with fatal hemolytic anemia indicated increased membrane coating by the third component of complement; this was not evident in a second rhinoceros that survived a hemolytic event.

Anemia, Hemolytic↗
PubMed1986

Acute intravascular hemolysis in the black rhinoceros: erythrocyte enzymes and metabolic intermediates.

Enzymes of aerobic and anaerobic glycolysis, glutathione cycling, and nucleotide metabolism were assayed on erythrocytes from 7 healthy rhinoceroses, 2 rhinoceroses during periods of intravascular hemolysis, and 1 rhinoceros without clinical signs of illness, which was the mother of 3 offspring with intravascular hemolytic syndrome. Measurements also were made of erythrocyte concentrations of glycolytic intermediates, adenine nucleotides, and glutathione. Although comparison of results for healthy and affected rhinoceroses did not identify an enzyme abnormality as a cause for the hemolytic syndrome, the data provided information regarding the metabolic characteristics of erythrocytes from healthy rhinoceroses.

Adenine Nucleotides↗
PubMed1985

Enteroclysis in the diagnosis of chronic unexplained gastrointestinal bleeding.

In a six-year period (1977-83), lesions were identified by enteroclysis in 26 patients with melena or recurrent gastrointestinal bleeding undiagnosed by other modalities. These included nine Meckel's diverticula, three metastatic lesions, three primary carcinomas, one lipoma, four leiomyomas, five surgically created blind pouches, one carcinoid, and one idiopathic dilatation of the ileum. Our experience suggests that, when the standard diagnostic procedures used to investigate chronic gastrointestinal blood loss are unrevealing, enteroclysis should be performed. The method is fast, accurate, is done in one sitting, and can be productive in the diagnostically difficult patient.

Adenocarcinoma↗
PubMed1985

Bilateral carotid occlusion and the sympathetic regulation of insulin secretion.

After a 2-min bilateral carotid arterial occlusion (BCO) in puppies, a centrally originating, sympathetic discharge takes place which increases heart rate and blood pressure. We examined the specificity of this sympathetic neural outflow by determining whether it also caused a direct neurally mediated inhibition of insulin release from the pancreas. The effects of this BCO on portal venous insulin concentrations, as well as on heart rate and blood pressure, were examined during i.v. glucose infusions of 0 (saline), 5 and 15 mg/kg X min-1. To determine changes in splanchnic blood flow and to more closely estimate pancreatic insulin secretion rates, a major vein draining the pancreas, the gastroduodenal, was catheterized. Blood flows and the amount of insulin traversing this vein per min (insulin flow rate) were followed before, during and after BCO. BCO decreased portal vein insulin concentrations during i.v. glucose infusions of 5 and 15 mg/kg X min-1, but not when saline was infused. Since bilateral splanchnicotomy altered this result little and since BCO increased blood flow and the insulin flow rate in the gastroduodenal vein, it appears that the lower portal venous insulin concentrations during BCO are secondary, not to sympathetically induced decrease in insulin secretion rates but, to dilution of pancreatic effluent blood. We conclude that while BCO causes appropriate changes in heart rate and blood pressure, this central stimulus to the sympathetic system does not provide a direct neuroendocrine reflex change in insulin secretion. BCO alters portal venous insulin concentration indirectly, and the alteration depends on the plasma glucose concentration and an enhancement in the splanchnic blood flow.

Animals↗
PubMed1985

Surgical complications of peritoneal dialysis catheters.

Peritoneal catheters are relatively easy to insert but are associated with specific complications. Proper placement and appropriate management reduce the problems associated with these complications, reduce morbidity and mortality, and increase catheter survival. On the basis of our findings the following procedures are recommended: placement of the catheter in the operating room, use of a paramedian incision, closure of the fascia with a running nonabsorbable suture, use of small exchanges initially to allow for healing, cessation of peritoneal dialysis for a limited time when leaks occur, performance of omentectomy when necessary, repair of abdominal wall hernias preoperatively or whenever they occur, maintenance of meticulous asepsis, removal of the catheter after fungal peritonitis or multiple episodes of peritonitis with the same organism, and early operation if there is any doubt of an intraabdominal catastrophe.

Adult↗
PubMed1985

Hemorrhagic pancreatitis: a complication of transcatheter embolization treated successfully by total pancreatectomy.

Since pancreatitis can be produced experimentally in dogs by embolization of microspheres into the pancreatic arterial circulation, there has been speculation that intentional or inadvertent embolization of the pancreas in human subjects could also produce pancreatitis. Although such therapeutic embolization has increased, no pathologically documented case of this complication has been recorded. We have reported the first such case occurring in a patient with a large, highly vascular, nonfunctioning islet cell carcinoma of the tail of the pancreas preoperatively embolized with Gianturco coils and Gelfoam particles suspended in sodium tetradecylsulfate solution to facilitate distal pancreatectomy. The resultant hemorrhagic pancreatitis and duodenal necrosis required a total pancreatectomy. We conclude that, by itself, occlusion of the origin of the splenic and gastroduodenal arteries with coils would have been effective and without complication; however, the addition of Gelfoam particles in a sclerosing solution reduced the microscopic pancreatic circulation to a critical point and resulted in hemorrhagic pancreatitis.

Adenoma, Islet Cell↗
PubMed1985

Flow artifacts in double-contrast esophagography.

Artifacts related to barium flow during double-contrast esophagography may obscure mucosal surface details. Double-contrast esophagograms with flow artifacts of 35 patients were evaluated to determine the effect on radiographic interpretation and to assess the method of examination. Initial radiographs obtained during swallowing of barium were compared with those obtained after a slight delay while patients repeatedly dry swallowed. When severe surface flow artifacts were present, the extent of mucosal disease was underestimated in all cases. Mild surface flow artifacts interfered with the demonstration of the reticular pattern of Barrett esophagus, and luminal flow artifacts caused misinterpretation. The demonstration of strictures was unaffected by flow artifacts. This study suggests that the dry swallowing maneuver and some delay improve depiction of esophageal surface details on double-contrast radiographs and obviate interpretive error from barium flow artifacts.

Barium Sulfate↗
PubMed1985

The hepatic vagus nerve and the neural regulation of insulin secretion.

Despite considerable evidence that vagal neural efferent pathways between brainstem and pancreatic islets may alter the secretion of insulin, afferent pathways which might affect this system have received little attention. In the present work we have examined the effects on plasma insulin concentration of several treatments designed to alter the neural activity of the hepatic vagus nerve, a major afferent pathway between the liver and the medulla. The hepatic vagus nerve was acutely sectioned or stimulated electrically in separate experiments in rats. In a third experiment, glucose or 3-O-methylglucose was given ip to stimulate or inhibit, respectively, the hypothetical hepatic glucoreceptors. The effects of these treatments were assessed by measuring arterial or portal plasma insulin concentrations. Anesthesia and its possible secondary inhibitory effects on insulin secretion were avoided by a spinal sectioning of the rats in the cervical region, before experimentation. Acute section of the hepatic vagus nerve between the liver and the main anterior vagal trunk caused an increase in both arterial and portal plasma insulin concentrations. Stimulation of the central end of the nerve suppressed the concentration of the hormone in both the arterial and portal plasma relative to sham-stimulated controls. Section of the celiac vagal branches to the pancreas abolished these changes. Intraperitoneal glucose enhanced arterial insulin more in sham-vagotomized than in hepatic-vagotomized rats. After 3-O-methylglucose was given ip, the response was the opposite: insulin rose more in the arterial plasma of the hepatic-vagotomized animals than in those sham vagotomized. These results suggest that the hepatic vagus nerve plays a role in the regulation of insulin secretion. They are consistent with the hypothesis that afferent fibers in this nerve exert a tonic inhibition on the brainstem centers of an efferent vagal pancreatic neuroendocrine system.

3-O-Methylglucose↗