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Biomedical subjects

R G Robinson

Publications and source records attributed to R G Robinson.

At least 343 records · Page 19Linked to original sources
PubMed1976

The critical relationship of intravascular blood volume and vascular capacitance in sepsis.

The present article represents a more detailed study of the septic leg models used in our previous work on sepsis and septic shock. An improvement in this model is described, and the period of maximum hyperdynamic response is delineated. An attempt was made to measure changes in the rate of swelling of the septic leg in responding and nonresponding dogs. The exquisitely sensitive response of the dog with sepsis to minor reductions in blood volume was demonstrated. Results of our previous studies concerning the redistribution of blood flow in sepsis were extended using radioactively labeled microspheres.

Animals↗
PubMed1976

Effects of antacids on gastric emptying.

Aluminum hydroxide gel delays gastric emptying in rats and man. This effect of aluminum hydroxide gel varies with the concentration of aluminum in solution in the stomach when pH, osmolarity, and anion content are held constant. Because aluminum solubility drops as pH is raised, those antacids which neutralize more effectively than aluminum hydroxide gel alone and which contain "nonreactive" aluminum hydroxide result in lower aluminum concentration and do not affect the rate of gastric emptying in animals or in man. By using [51Cr]sodium chromate and a gamma camera technique, half-emptying time in 6 subjects with no gastrointestinal disease was shown to be prolonged from 13.1 min after water ingestion to 48.0 min after three hourly doses of aluminum hydroxide gel. Conventional nonabsorbable markers, including phenol red, were found to be of limited use for studying gastrointestinal function in the presence of antacid gels, most of which adsorb dyes.

Adolescent↗
PubMed1976

Prognosis for recovery of function in acute renal failure. Value of the renal image obtained using iodohippurate sodium I 131.

Twenty-four survivors of acute, nonobstructive, nonnephritic renal failure had a renal scan using iodohippurate sodium I 131 performed early in the acute illness. Scans were judged according to whether the renal images were prominent, faint, or absent during the first 30 minutes after intravenous injection of 100 to 250 microcuries of iodohippurate sodium I 131. All ten patients with prominent renal images attained life-sustaining renal function with an average postrecovery creatinine clearance of 80 ml/min. Of the seven patients with faint renal images, six recovered life-sustaining renal function (average creatinine clearance of 39 ml/min), and one required chronic hemodialysis. Seven patients had no renal image initially; four recovered life-sustaining renal function with an average creatinine clearance of 25 ml/min; three required chronic hemodialysis. We conclude that, for patients with acute renal failure, the appearance of the renal image obtained using this substance is an important indicator of renal viability and of the likelihood for functional recovery.

Acute Kidney Injury↗
PubMed1976

Serotonin accumulation in the guinea-pig myenteric plexus: ion dependence, structure-activity relationship and the effect of drugs.

The specific accumulation of serotonin in neurons of the guinea-pig myenteric plexus was examined. Nonadrenergic neurons have been shown to be responsible for this accumulation. Serotonin accumulation, known to be sodium-dependent, was found to be inhibited by elevating the external potassium concentration. Accumulation was inversely related to the concentration of potassium and was also decreased in the presence of 0 mM Ca++ or 12 mM Ca++. The affinity of analogous molecules for the myenteric plexus was greatly reduced in compounds which had no alkyl amino side chain, in which the amino group was methylated or which had no 5-hydroxyl group. Most analogs competitively inhibited serotonin accumulation and 6-hydroxytryptamine was demonstrated by histofluorescence to be taken up into the myenteric plexus after chemical sympathectomy with 6-hydroxydopamine. Serotonin accumulation was also inhibited by tricyclic antidepressants and amphetamines. The inhibition of serotonin accumulation by these compounds differed from their inhibition of accumulation of norepinephrine. As in the central nervous system, chlorimipramine was the most potent tricyclic antidepressant against accumulation of serotonin while desmethylimipramine was the most potent inhibitor of the accumulation of norepinephrine. Amphetamines were more effective inhibitors of serotonin accumulation than were tricyclic antidepressants, but all of these drugs were more effective against the accumulation of norepinephrine than serotonin. This study confirms the existence of a unique population of axons int he mammalian myenteric plexus which are distinguishable by their characteristic accumulation of serotonin and have not been found elsewhere in the peripheral nervous system.

Amphetamines↗
PubMed1975

The origins and relative distribution of polysaccharidases in rheumatoid and osteoarthritic fluids.

Three lysosomal polysaccharidases were measured in synovial fluid (SF) and serum from rheumatoid (RA) patients, SF from osteoarthritic (OA) patients, and serum from healthy volunteers. (1) There was no correlation between the enzyme levels and white cell counts in the SF. (2) beta-glucuronidase and beta-N-acetylglucosaminidase were markedly elevated in the SF of RA as compared to OA. (3) beta-glucuronidase and beta-N-acetylglucosaminidase levels in the SF of RA correlated well with each other but not with hyaluronidase. (4) beta-glucuronidase and beta-N-acetylglucosaminidase levels were higher in the SF of RA than in the corresponding serum, while the converse was true for hyaluronidase. (5) Hyaluronidase levels were significantly higher in RA serum than in normal serum. These results suggest that the synovial membrane may be the source of beta-glucuronidase and beta-N-acetylglucosaminidase, while hyaluronidase is derived from a source remote from the joint via the serum. This source of hyaluronidase may be the liver. (J Rheumatol 2: 393-400, 1975).

Acetylglucosaminidase↗
PubMed1975

Chlorpromazine induced hyperphagia in the rat.

During a four month period, 20 rats treated with subcutaneous injections of chlorpromazine (CPZ), at any dose tested, gained less weight than saline treated controls. However, increased feeding did occur on the first day of CPZ treatment if the animal was drug free for at least two days prior to treatment. The "first day" hyperphagia was a time limited response that did not occur until 8 hours after CPZ injection and lasted only one day. During the period of hyperphagia, treated animals showed increased motivation to obtain food. Although sedation is a marked effect of CPZ and may be the reason for the delayed onset of hyperphagia, sedation with a different drug does not cause hyperphagia. It is suggested that accumulation of a metabolite of CPZ may interfere with the feeding response and cause the hyperphagia to disappear after the first day of treatment.

Animals↗
PubMed1974

Benign rheumatoid arthritis of the aged.

A severe type of rheumatoid arthritis which is seen in 25% of cases that present with the disease after the age of 60 is a self-limiting illness. It can be well controlled during the acute severe phase and has a good prognosis. This paper describes 29 patients with this pattern of disease who were separated from a larger group of 110 elderly onset cases.

Adrenal Cortex Hormones↗