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Biomedical subjects

R G Robinson

Publications and source records attributed to R G Robinson.

At least 325 records · Page 18Linked to original sources
PubMed1977

A fluorescent histochemical study of changes in noradrenergic neurons following experimental cerebral infarction in the rat.

Following surgical ligation of the middle cerebral artery in the rat, central catecholamine containing neurons were studied using the glyoxylic acid histochemical technique. By 5 days after the ischemic lesion, the density of fluorescent varicosities decreased in both uninjured cerebral cortex and the cerebellar cortex and the intensity of fluorescence of somata in the ipsilateral and contralateral locus coeruleus decreased as compared with controls. At 20 days afer lesioning, catecholamine containing neurons looked normal under fluorescence microscopic examination, except fine varicose fluorescent axons were present for the first time among the cellular debris of the lesion and appeared to have sprouted into the lesion site. However, by 40 days after surgery, there was a marked increase in the density of fluorescent varicosities in the uninjured ipsilateral cerebral cortex, in the contralateral cerebral cortex, and in the cerebellum. These observations confirm the view that an ischemic cortical lesion can lead to profound changes in cetecholamine containing neurons in distant areas of the brain which are uninjured by the local infarction.

Animals↗
PubMed1977

Fulminant hepatitis. A presentation of Wilson's disease.

A boy, 10 years of age, was admitted to the hospital with rapid onset of hepatic failure and died within three weeks. Laboratory and pathological data were consistent with Wilson's disease. We discuss the importance of Wilson's disease in the differential diagnosis of acute liver failure.

Child↗
PubMed1977

Prolongation of gastric emptying by oral propantheline.

The present study shows that a single oral recommended dose of propantheline bromide normally doubles the mean gastric half-emptying time in man. In a prospective, double-blind, randomized crossover design 13 normal subjects were given 30 mg propantheline or placebo 90 min before taking a 113m-indium-labeled liquid test meal, the volume of which was adjusted to body weight. The disappearance of radioisotope from the area of the stomach was determined by external gamma counting. After placebo the mean half-emptying time was 68 min and after propantheline it was 135 min (p less than 0.005). Although salivary flow decreased and pulse rate increased there were no visual disturbances. In studies already reported maximally tolerated oral doses of quaternary ammonium anticholinergic drugs have not consistently retarded gastric emptying in man.

Adult↗
PubMed1977

Childhood pheochromocytoma: treatment with alpha methyl tyrosine for resistant hypertension.

A 12-year-old boy with a norepinephrine-secreting pheochromocytoma that caused hypertension resistant to oral alpha adrenergic blockade is reported. Resistance to alpha adrenergic blocking agents developed when the patient's daily propranolol dosage was lowered from 10 to 1 mg/kg. Subsequently, alpha methyl tyrosine, an inhibitor of tyrosine hydroxylase, the rate-limiting enzyme in catecholamine biosynthesis, controlled the patient's blood pressure and was associated with reduction in total urinary catecholamine excretion. Norepinephrine content of the tumor and uninvolved adrenal gland removal at surgery was reduced. These findings confirm that alpha methyl tyrosine inhibited in vivo synthesis of catecholamines.

Adrenal Gland Neoplasms↗
PubMed1977

Dr. R. M. Mason.

Explore the source record for details and available documents.

England↗
PubMed1977

Role of the radionuclide brain image in the diagnosis of brainstem gliomas.

The noninvasive detection of brainstem gliomas remains difficult. Eleven of our patients with proven brainstem gliomas had radionuclide brain imaging prior to the initiation of therapy or confirmation of the diagnosis; six studies were positive. Pneumoencephalography remains the most reliable diagnostic test for brainstem glioma, and is invariably required for confirmation. Although angiography is useful in the evaluation of vasocularity it may not detect small infiltrating lesions. Radionuclide brain imaging is useful in the initial workup of patients with suspected brainstem gliomas.

Adult↗
PubMed1977

Pharmacological treatment following experimental cerebral infarction: implications for understanding psychological symptoms of human stroke.

Middle cerebral artery ligation in the rat produces decreases in catecholamine concentrations at brain sites uninjured by ischemic damage and a transient increase in spontaneous horizontal activity. Development of this hyperactivity can be blocked by postoperative treatment with the antidepressant, desmethylimipramine, or by preoperative destruction of norepinephrine terminals with 6-hydroxydopamine. These results suggest that ischemic damage to the cerebral cortex which injures some axonal branches of elaborately arborizing catecholamine-containing neurons may alter the biochemical and functional state of the entire system in its intact collateral axons. Thus the concept of stroke as a local injury producing symptoms by local structure-function relationships is conceptually inadequate, and poststroke symptoms must be evaluated with these "whole brain" concepts in mind. We suggest that the poststroke symptoms of apathy and depression may represent emotional changes which result from pathophysiological processes in catecholamine neurons far from the site of the stroke.

Animals↗
PubMed1977

Organ distribution of 99mTc- and 51Cr-labeled autologous peripheral blood lymphocytes in rabbits.

The present series of experiments was designed to compare 99mTc with 51Cr as a lymphocyte label in rabbits and to correlate organ distribution patterns as determined by postmortem counting with those observed by 99mTc gamma imaging. The distribution of 51Cr and 99mTc-labeled, viable and nonviable, unreduced or SnCl2-reduced autologous lymphocytes was determined 2 hr following intravenous injection. Viable 99mTc-labeled lymphocytes localized primarily in the liver, lungs, and kidneys or remained circulating in the blood. These compartments accounted for 34-54% of the injected radioactivity. One to three percent of the injected dose was recovered from the spleen, thyroid, bladder, and stomach, and all remaining organs accounted for less than 1%. Reduced, nonviable cells showed increased localization in the lungs and liver (48%) compared to viable unreduced cells (15%). Chromium-51-labeled lymphocytes were distributed primarily to the liver, lungs, and spleen or remained circulating in the blood. Hepatic localization differed from that observed with viable, unreduced 99mTc-labeled lymphocytes (32 vs. 12%), but vascular compartmentalization was similar (18 vs. 15%). The distribution of pertechnetate and reduced 99mTc was different from that of 99mTc-labeled cells. The urine and blood accounted for 84% of the recovered radioactivity, and for 43-45% of the injected dose, indicating that the patterns we observed with 99mTc-labeled lymphocytes truly represented cell-associated radioactivity. Similarly, the distribution of Na251CrO4 differed from that of 51Cr-labeled cells. The kidneys and urine accounted for 26% of the injected dose, compared with 5% for 51Cr-labeled lymphocytes, and only trace amounts of radioactivity were found in the lungs and spleen. The distribution of 99mTc-labeled cells, as determined by scintigraphy 90 min after injection, correlated well with data obtained by postmortem counting, suggesting that 99mTc may be applicable as a lymphocyte label for diagnostic gamma-imaging procedures.

Animals↗
PubMed1976

Treatment of advanced bladder cancer with adriamycin and 5-fluorouracil.

The cytotoxic drug combination of adriamycin and 5-fluorouracil has resulted in a 35% objective response in 20 patients with advanced bladder cancer. This has been achieved with minimal toxicity and on an out-patient basis. If the survival rate of patients with invasive bladder cancer is to be improved it seems likely that some form of systemic treatment will need to be added to the local measures currently in use. Further studies of different chemotherapeutic agents should help to define an effective and safe form of adjunvant therapy.

Aged↗
PubMed1976

Peritoneal transfer of thiamphenicol during peritoneal dialysis.

The pharmacokinetics of thiamphenicol (TAP) was studied in 17 functionally anephric patients during peritoneal dialysis. Eleven patients were given single intramuscular injections of TAP in doses of 10 to 20 mg/kg of body weight. After this, serial blood samples and outflow dialysate collections were assayed for TAP by gas chromatography. The mean overall elimination rate constant was 0.036 +/- 0.007/h, the serum half time was 8.4 h, and the apparent volume of distribution was 71.0% (+/-14.39%) of the body weight. These parameters were not significantly different from those determined in anephric patients not on dialysis. The mean recovery of the administered TAP doses in the pooled outflow dialysate was 7.7% (+/-2.76%) over 22 h. In six other patients TAP was added to the inflow dialysate in concentrations of 10 to 20 mg/liter for 22 h. Throughout the dialysis periods, serum TAP levels did not rise above 4 mug/ml in transfer of TAP.

Adult↗
PubMed1976

Angiographic documentation of systemic-portal venous shunting as a cause of a liver scan ""hot spot'' in superior vena caval obstruction.

Four patients with superior vena caval obstruction were evaluated with contrast venography and radiocolloid liver scans to investigate systemic-portal venous shunting as a cause of a liver scan "hot spot". In two of the cases a hot spot due to systemic-portal venous shunting was documented by angiography. The venous anatomy and pathophysiology related to hot spot formation on the liver scan is discussed. To develop a liver scan hot spot it appears necessary to have considerable systemic-portal venous flow through anterior parietal and periumbilical venous channels.

Angiography↗
PubMed1976

Osteoblastomas of the axial skeleton shown by skeletal scanning: case report.

Two patients with osteoblastoma of the axial skeleton showed intense uptake of 99mTc-polyphosphate and 99mTc-diphosphonate on skeletal scans. Although this lesion is uncommon, it should be included in the differential diagnosis for young patients who show abnormal accumulation of 99mTc-phosphates in the axial skeleton.

Adult↗