Biomedical subjects

J Galloway

Publications and source records attributed to J Galloway.

48 records · Page 3Linked to original sources

PubMed1985

Portaprival collaterals following distal splenorenal shunt. Incidence, magnitude and associated portal perfusion changes.

Collateral venous pathways develop between the high pressure portal vein and low pressure splenic vein following distal splenorenal shunt. This review of angiography in 50 patients with cirrhosis prior to and 1 year after DSRS shows that 98% developed collaterals: 72% transpancreatic, 48% transgastric, and 46% colonic. Multiple pathways developed in 64% of patients. Grading of the size of these collaterals showed that in 74% these exceeded the size of the portal and/or superior mesenteric vein. The effect of these collaterals on portal perfusion showed that 32% lost perfusion at 1 year, but significantly (P less than 0.05) more alcoholics (48%) lost perfusion than nonalcoholics (16%). The size, site and number of collaterals was not different between etiologies. Late follow-up in a subset of 32 of the patients showed no change in the site, and minimal increase in size of the collaterals at 3-11 years, with no further loss of portal perfusion. We conclude that virtually all patients develop collaterals after DSRS, these are along predictable pathways and are of significant size in the majority. However, development of collaterals per se does not equate to loss of portal venous flow, and a stable pattern is set in the first year after shunt. Characterization of these pathways will permit new approaches to minimizing their development.

Angiography↗

PubMed1984

Biosynthetic human insulin and proinsulin have additive but not synergistic effects on total body glucose disposal.

Recent studies from our laboratory have demonstrated that human biosynthetic proinsulin has a much slower MCR than insulin as well as a greater effect on hepatic than on peripheral tissues. Since both of these features make proinsulin potentially useful as an adjunct to insulin, the present study was undertaken to characterize the biological effects of combined infusions of insulin and proinsulin. As an initial study, multiple euglycemic clamp studies were performed in six normal subjects to construct dose-response curves for insulin- and proinsulin-mediated glucose disposal. Insulin infusion rates of 0.63, 1.67, 5, and 10 micrograms/M2 X min were compared to proinsulin infusion rates of 2.75, 7.5, 22.5, and 45 micrograms/M2 X min. Analysis of these dose-response curves indicated that proinsulin-mediated glucose disposal was approximately 7% that of insulin. Each subject also received a combined infusion of insulin (0.63 micrograms/M2 X min) and proinsulin (2.75 micrograms/M2 X min). The mean (+/- SE) glucose disposal rate obtained during the combination study (319 +/- 21 mg/M2 X min) was similar to that predicted by adding the results from the individual hormone infusions (307 +/- 21 mg/M2 X min). Analysis of the dose-response curves for insulin and proinsulin was also useful in predicting the glucose disposal rate during the combination study (290 +/- 19 mg/M2 X min). Thus, using either approach to predict the glucose disposal rates, insulin and proinsulin appeared to have additive effects on total body glucose disposal.

Adult↗

PubMed1982

Cerebral evoked potentials: a historical review of the marseilles contributions and a preliminary report on a study of the effects of various stimulus parameters on the P90 component of the pattern visual evoked potential.

A preliminary report is given of a study in 10 normal subjects comparing the laterality of the P90 component of the PVEP as elicited by pattern reversal and pattern appearance stimuli delivered monocularly and binocularly in the central and peripheral portions of one-life field. P90 was shown often to appear maximally over the hemisphere ipsilateral to the stimulus field with pattern reversal stimuli in central targets viewed monocularly. Pattern appearance, peripheral targets and binocular stimulation provoked less consistently lateralized and sometimes differently configured responses. It is concluded that while all combinations provoked responses consistent with a dipole generator model similar to that proposed by Blumhardt et al. (1978), these different modes of stimulation cannot be considered to be equivalent.

Cerebral Cortex↗

PubMed1981

A comparison of visual, brainstem auditory, and somatosensory evoked potentials in multiple sclerosis.

Multimodality evoked potentials testing including PVEPs, SEPs and BAEPs was done in 112 patients who were known or suspected to have multiple sclerosis. The incidence of abnormal evoked potential findings in each of these systems was considered in patients in the different diagnostic categories of M.S. Results were also evaluated with respect to the presence of abnormal clinical visual, somatosensory, or brainstem signs. The PVEP was found to be the most frequently abnormal in even patients without clinical involvement in the visual system (45% of patients with definite, probable, or possible M.S.), the SEP was less frequently abnormal in the absence of clinical signs (35% in patients with M.S.), and the BAEP showed the lowest frequency of abnormalities in patients without brainstem signs (14% in patients with M.S.). Combining the three types of evoked potentials significantly increased the percentage of M.S. patients having abnormal findings, compared to any of these tests alone, with 97% of "definite" M.S. patients, 86% of "probable" M.S. patients and 63% of "possible" M.S. patients having at least one of these EP tests abnormal.

Adult↗

PubMed1978