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J Washington

Publications and source records attributed to J Washington.

27 records · Page 2Linked to original sources

Blood flow limitation of stimulated gastric acid secretion in the rat.

Secretagogue-stimulated gastric acid output is reduced when gastric mucosal blood flow is below normal. We tested the hypothesis that the reduction in acid secretion associated with reduced mucosal blood flow was due to a decrease in the delivery of the secretagogue. Gastric acid output was determined by continuous gastric lavage with 0.15 M NaCl, and gastric corpus mucosal blood flow was measured by hydrogen gas clearance in anesthetized, pylorus-ligated rats before and during a period of hypovolemia-induced reduction in mucosal blood flow. A linear correlation between pentagastrin- and histamine-stimulated gastric acid output and gastric corpus mucosal blood flow during hypotension over a range of mucosal blood flow rates was found, and each was expressed as a percentage of the plateau values before hemorrhage. When the dose of pentagastrin was doubled or tripled, or when the stimulation of gastric acid secretion was vagus nerve stimulation, a stimulant of acid secretion that is independent of blood flow for secretatogue delivery, the reduction in gastric acid output by hypotension was not reversed. We conclude that stimulated gastric acid secretion during hemorrhagic hypotension is blood flow-limited and not related to inadequate delivery of secretagogue to parietal cells.

Animals↗

Neurotensin-like immunoreactivity released into the portal vein by duodenal acidification in the dog.

The present study in the dog evaluates neurotensin as a potential hormone, mediating the inhibition of gastric acid secretion by duodenal acidification. Histamine-stimulated acid output was determined before and during duodenal acidification. Portal vein blood was obtained and assayed for carboxy-terminal neurotensin-like immunoreactivity (NTLI). Duodenal perfusion with 15 mmol HCL for 30 min significantly inhibited histamine-stimulated acid output to 67% of control output. This inhibition was not associated with any change in the peripheral plasma NTLI, but the portal plasma NTLI was significantly elevated from 27 to 78 pM. The effect of duodenal acidification on liver extract meal-stimulated acid secretion was determined in a second group of dogs without portal vein catheter. Duodenal perfusion with 15 mmol HCl for 30 min significantly inhibited meal-stimulated acid secretion to 37% of control output. Intravenous infusion of synthetic neurotensin to a plasma level of 130 pM was required to inhibit meal-stimulated acid output significantly. In summary, NTLI is elevated in portal, but not peripheral, plasma after duodenal acidification. The associated inhibition of acid secretion is not due to hormonal action of neurotensin.

Animals↗

Immunologic evaluation in the nutritional assessment of children with cancer.

Eighty-one newly diagnosed untreated pediatric cancer patients (48 hematopoeitic malignancies, 17 solid tumors, 16 benign diseases) were evaluated with immunologic and nutritional parameters. The mean absolute lymphocyte count was adequate in the three groups. Reduced T-lymphocytes were seen in the solid tumors. Mitogenic response of hematopoietic and solid tumor patients' lymphocytes was low. Correlation of immunologic, dietary, and nutritional factors showed that for patients with solid tumors there was a positive significant correlation between weight/height percent and lymphocyte reactivity to phytohemagglutinin, concanavalin A, and pokeweed mitogen (p less than .05). Iron intake showed a significant positive correlation with in vitro mitogen reactivity for the solid tumor group (p less than .05) and benign diseases (p less than 0.01). Immune derangements found among patients with hematopoietic malignancies can be due to replacement of normal bone marrow with malignant cells. In solid tumor patients mitogen reactivity appears to be a reflection of nutritional state, and dietary iron is a possible factor.

Adolescent↗

Team management of failure to thrive.

A multidisciplinary team approach to treatment of failure to thrive in infancy and early childhood permits the simultaneous consideration of nutritional, medical, and psychosocial risk factors associated with this complex syndrome. The registered dietitian works with the physician, nurse, and social worker to provide an integrated evaluation of nutrition history, feeding patterns, medical status, social situation, developmental level, and interactional qualities of the child with failure to thrive. Nutritional management of failure to thrive emphasizes: (a) ongoing assessment of nutritional status and rate of catch-up growth, including regular collection of anthropometric measurements; (b) provision of energy and protein in amounts sufficient to meet requirements for catch-up growth; and (c) concrete, individualized nutrition instruction. Long-term follow-up at regular intervals in coordination with other members of the failure-to-thrive team provides the opportunity to reinforce nutrition instruction and to reassess and adapt meal plans to meet the growing child's changing nutritional needs.

Anthropometry↗

The quantitative description of a radiation therapy plan.

A computer program has been designed to describe radiation therapy plans in numerical as opposed to graphical terms. Treatment is specified by using the average dose in the target area. The rationale for its development and an illustration of its use are given.

Computers↗

Purification of cyclic AMP- and cyclic GMP-dependent protein kinases from rat skeletal muscle.

Cyclic AMP-dependent protein kinase (cAMP-PrK) regulatory subunits, RI and RII, and cyclic GMP-dependent protein kinase (cGMP-PrK) have been simultaneously purified from skeletal muscle, utilizing sequential affinity chromatography on cyclic AMP-Sepharose. Rat skeletal muscle extract was chromatographed over DEAE-cellulose. Appropriate fractions, enriched in RI, RII or cGMP-PrK were further purified by affinity chromatography on cAMP-Sepharose. The protein kinase units were specifically eluted with cAMP or cGMP. A novel procedure, using two affinity columns, differing in their linkage of cAMP via either N6 or C-8 bonds, was developed to obtain RII free of other cyclic nucleotide binding proteins. In all cases, affinity chromatography was followed by HPLC gel exclusion chromatography to remove residual contaminating proteins. Proteins were purified to essential homogeneity as judged by silver stained SDS polyacrylamide gels. This procedure yields protein kinase subunits of high purity, and may be applicable to the isolation of these proteins from other sources.

Animals↗