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Biomedical subjects

M C Lewis

Publications and source records attributed to M C Lewis.

30 records · Page 2Linked to original sources
PubMed1990

In vivo transport kinetics and distribution of taurocholate by rat ileum and jejunum.

The transport kinetics and distribution of taurocholate (TC) from the ileum and jejunum were evaluated in anesthetized Sprague-Dawley rats. Uptake and transport kinetics were determined after simultaneous administration of equimolar solutions of [3H]taurocholic acid ([3H]TC) in the ileum and [24-14C]taurocholic acid ([14C]TC) in the jejunum of anesthetized rats. At TC concentrations between 0.3 and 15 mM, total ileal absorption exceeded jejunal absorption 15- to 25-fold. The apparent Km and Vmax for ileal absorption of TC were 5.6 mM and 65.5 nmol.min-1.cm-1, respectively. Tissue distribution studies following uptake from the ileum and jejunum were done with 75Se-labeled homocholic acid taurine (75Se-HCAT). In the ileum, 82% of the 75Se-HCAT removed from the lumen was found in the bile, 10.6% was found in the ileal wall, and 7.3% was found in the liver. In the jejunum, 24.1% was found in bile, 0.6% was found in the liver, and 75.3% remained in the jejunal wall. These data show that the ileum is much more efficient and better equipped than the jejunum to take up and transport TC at concentrations up to 15 mM.

Animals↗
PubMed1988

Midazolam infusion and the benzodiazepine antagonist flumazenil for sedation of intensive care patients.

ICU patients often require sedation. Midazolam (M), a new imidazobenzodiazepine, features rapid onset and rapid elimination time. Flumazenil (Ro 15-1788) is a new benzodiazepine antagonist. We studied the efficacy and safety of M by continuous infusion in 28 ICU patients: 16 post major surgery, and 12 medical patients, aged 20-77 years. M was administered as a loading dose of 0.05-0.15 mg/kg per min followed by continuous infusion of 0.05-0.1 mg/kg per h titrated to maintain patients asleep but arousable. M was administered for up to 14 days in doses of 1-15 mg/h and cumulative doses of up to 1915 mg. No untoward effects were noted except for slight decreases in blood pressure following the loading dose. ACTH challenge tests performed before and 24 h or more following the start of M showed no depression of adrenal responsivity. All patients meeting weaning criteria were weaned off mechanical ventilation while still on M. In 13 patients extubation was performed immediately after M was stopped, and flumazenil (0.38 +/- 0.27 mg, i.v.) given until full awakening. Patients remained awake yet calm. Vital signs remained stable after flumazenil. Midazolam by continuous infusion appears to be a safe and effective mode of sedation in ICU patients. Flumazenil may increase the flexibility and safety of this mode of sedation.

Adult↗
PubMed1987

Evaluation of the hypolipidemic activity of xenalipin in experimental animals.

Xenalipin (4'-trifluoromethyl-2-biphenylcarboxylic acid) is a chemically novel compound which has been found to be an effective hypolipidemic agent in two animal species. Significant reductions in serum cholesterol and triglycerides were observed in cholesterol-cholic acid-fed rats following oral doses of 10-30 mg/kg/day. Xenalipin was considerably more potent than clofibrate, nicotinic acid, and cholestyramine in the same model. Lipoprotein analysis showed that xenalipin reduced cholesterol and protein content in very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL), and low density lipoprotein (LDL). Triglycerides were reduced in VLDL and IDL. Xenalipin was also effective in reducing serum cholesterol and triglyceride concentrations in normocholesterolemic rats. In diet-induced hypercholesterolemic African green monkeys, xenalipin at oral doses of 15-60 mg/kg b.i.d. reduced serum LDL-cholesterol concentrations. These results suggest that xenalipin has a profile of activity which would be beneficial in therapy for hyperlipidemia.

Animals↗
PubMed1987

Colostomy or ileostomy after colorectal anastomosis?: a randomised trial.

Sixty one patients were entered in a randomised trial to compare transverse loop colostomy with loop ileostomy after a colorectal anastomosis thought to be at risk of dehiscence. Radiologically proven breakdown of the colorectal anastomosis occurred in 13% of these selected patients and most frequently in the colostomy group. Ileostomies functioned earlier than colostomies (P less than 0.001) but there was no other significant difference in outcome between the groups. In 52 patients intestinal continuity was restored by excision of the stoma within a month of construction with no difference in morbidity between the two groups. A loop ileostomy, closed as soon as the colorectal anastomosis has healed, is recommended as an alternative to transverse colostomy.

Aged↗
PubMed1986

Specificity of the surface aminopeptidase in Moniliformis moniliformis (Acanthocephala).

The hydrolysis of various oligopeptides in solution by intact Moniliformis moniliformis was examined using paper chromatographic analysis of the incubation medium. In the presence of transport inhibitors, the respective peptide sub-units and/or amino acid residues accumulated in the bathing medium. Only peptides with serine, methionine, leucine or alanine at the NH2-terminal end of the peptide were hydrolysed. There was no hydrolysis when these amino acids were located internally or at the COOH-terminus indicating genuine aminopeptidase activity of the class, alpha-aminoacylpeptide hydrolase. Hydrolysis was negligible when the NH2-terminus was arginine, aspartic acid, glutamic acid, glycine, histidine, lysine, phenylalanine, proline, tryptophan, tyrosine, or valine. In separate experiments, mediated uptake of 0.1 mM 3H-leucine by the worms in 2 min was inhibited 100% by 5 mM unlabelled leucine or tri-serine, but only partially inhibited by 5 mM Ser-Gly (66%), 10 mM Ser-Gly (74%), 5 mM Leu-Leu (69%), 10 mM Leu-Leu (70%), 5 mM Leu-Gly (58%) or 5 mM Met-Met (69%). Because the inhibitions produced by 5 mM Leu-Leu plus 5 mM Met-Met (79%) or 5 mM Leu-Leu plus 5 mM Ser-Gly (76%) were not additive, a single enzyme is indicated. The name serine aminopeptidase is proposed because of its preference for serine.

Acanthocephala↗
PubMed1985

A randomized trial to compare single with multiple phenol injection treatment for haemorrhoids.

One hundred and twenty consecutive patients were entered into a randomized trial of single versus multiple phenol injection for the treatment of haemorrhoids. Follow-up at 3 and 12 months was available in 105 patients (56 in the single group and 49 in the multiple group). The results have shown that injection therapy, whether this be single or multiple, is an extremely effective form of therapy for patients with first or second degree haemorrhoids.

Adult↗
PubMed1975

Determinants of visual attention in real-wound scenes.

The present study examined the saliency of size, movement, and human content variables in visual selective attention. Ss named stimuli present in motion pictures of real world scenes or in animated cartoon controls during a 15-sec. exposure period. Regardless of the type of presentation that they saw, Ss tended to name large and/or moving stimuli more often than small and/or nonmoving stimuli. Also, small human stimuli were named more frequently than small nonhuman stimuli, while there were no differences between the frequencies with which large human and nonhuman stimuli were named. The order in which Ss named stimuli was not related to either the size, movement, or human content variables. Results are discussed in terms of the generalizability of the results of previous studies to conditions simulating the real world.

Attention↗