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Biomedical subjects

L D Lewis

Publications and source records attributed to L D Lewis.

At least 91 records · Page 5Linked to original sources
PubMed1978

Methoxyflurane anesthesia in mule deer (Odocoileus hemionus) fawns.

Methoxyflurane inhalation was used a total of 58 times to anesthetize 23 hand-reared mule deer (Odocoileus hemionus) fawns ranging from 25 to 85 days of age. Induction, maintenance, and recovery times were recorded for 28 anesthetizations. Induction time was unrelated to age and averaged 3 +/- 1 min (X +/- SD). Recovery time was longest in the youngest fawns and varied with the depth but not with the length of anesthesia. Induction and recovery were smooth, the depth of anesthesia was easily controlled, and analgesia and muscle relaxation was excellent. No adverse effects or complications were encountered.

Anesthesia, Inhalation↗
PubMed1978

Prevention of oxalate urolithiasis by some compounds.

Male Wistar rats were fed a basal diet, Purina Laboratory Chow, and an oxalate calculi-producing diet (CPD). The CPD was the basal diet containing 3 per cent glycolic acid. Sodium pyruvate, DL-alanine, alpha-keto glutaric acid, thiamine pyrophosphate, and L-glutamic acid were added to the CPD to determine their effectiveness in preventing calculi formation. The effectiveness of methyl glyoxal was determined by adding it to the drinking water. Rats fed CPD for 4 weeks developed calculi in the ureters, bladder, renal tubules, and/or renal pelvis and papilla. Rats in groups fed alanine and/or pyruvate had no calculi in their renal tubules or ureters; additionally, these rats had a significant reduction in incidence and amount of deposits in the renal pelvis and bladder. Rats in groups fed alpha-keto glutaric acid, thiamine pyrophosphate, L-glutamic acid, and methyl glyoxal developed equally or more severe oxalate urolithiasis than those on CPD alone. Results of this study show that either pyruvate or alanine at appropriate levels may be beneficial in preventing oxalate urolith formation.

Alanine↗
PubMed1975

Changes in plasma glucose and lactate concentrations and enzyme activities in the neonatal calf with diarrhea.

Plasma glucose and lactate concentrations and glutamate-pyruvate transaminase (SGPT), glutamate-oxalacetic transaminase (SGOT), alkaline phosphatase (AP), aldolase (ALD), creatine phosphokinase (CPK), and hydroxybutyrate dehydrogenase (HBD) activities were determined before, throughout the incubation period, and during the course of a viral-induced diarrhea in the neonatal calf. Hypoglycemia with a glucose concentration less than 40 mg/dl of plasma was observed in 3 of 10 calves. Plasma lactate concentration increased to 1.84 plus or minus 0.1 times normal in 7 and 6 to 7 times normal in 2 of the animals. The major change in both glucose and lactate concentrations during diarrhea occurred during the 24 hours preceding death. Changes in SGPT, SGOT, or AP activities were not observed, indicating the absence of marked hepatic damage. The ALD, CPK, and HBD activities were increased in 2 calves and the CPK alone was increased in 2 others, indicating cardiac and possibly skeletal muscle damage.

Alanine Transaminase↗
PubMed1975

Effect of perfusion rate on absorption, surface area, unstirred water layer thickness, permeability, and intraluminal pressure in the rat ileum in vivo.

Intestinal absorption and intraluminal pressures were measured at perfusion rates between 0.3 and 200 ml per min in the rat ileum in vivo. Glucose absorption from a 72 mM glucose solution and tritiated water ([3-H]water) diffusion rate were used to reflect changes in mucosal surface area. Glucose absorption from a 4 mM solution was used to indicate changes in unstirred water layer thickness, and mannitol and urea absorption were used as markers of passive mucosal permeability. In a partially obstructed intestinal segment, designed to keep the gut partially filled even at low perfusion rates and to minimize surface area change as perfusion rate was increased, glucose absorption from a 4 mM solution increased by 150% as perfusion rate was increased from 1 to 100 ml per min. Forty per cent of this increase was due to increased surface area (estimated from the change in [3-H]water absorption), and 110% of the increase is attributed to thinning of the unstirred water layer. Because mannitol absorption was zero at all perfusion rates, none of the enhanced glucose absorption rate need be attributed to enhanced mucosal permeability, even though intraluminal pressure was increased at higher perfusion rates. Urea absorption was apparently influenced by surface area and by permeability changes, but not by the thickness of the unstirred water layer. This model was also used to explore the effect of unstirred water layer thickness on the inhibitory effect of sodium replacement by magnesium on glucose absorption from a 4 mM glucose solution. Inhibition by sodium removal was equal at 1, 10, 100, and 200 ml per min perfusion rates, suggesting that unstirred water layer thickness does not play an important role in the interaction of glucose and sodium absorption when intraluminal sodium concentration is reduced. Additional experiments in an unobstructed ileal segment revealed that the major effect of enhanced perfusion rate is to increase mucosal surface area; relatively high rates of perfusion were required to thin significantly the unstirred water layer when intestinal outflow was not partially obstructed.

Animals↗
PubMed1975

Plasma corticoid changes during diarrhea in neonatal calves.

An acute, and usually fatal, diarrhea was induced in 11 healthy neonatal dairy calves by oral administration of an enteropathogenic viral inoculum. Fluid and electrolyte therapy was administered to several affected calves. Plasma corticoid values were determined by radio-immunoassay and competitive protein-binding assay, after purification of the plasma by paper chromatography. Statistical comparisons between control and diarrheic groups of calves were made on 5 corresponding experimental days. Plasma aldosterone values of 2 groups of diarrheic calves which died with and without treatment were greater (P less than 0.01) just before death than those of controls and diarrheic calves which recovered. Plasma hydrocortisone and progesterone values in the calves not treated were higher (P less than 0.05) on the day preceding death than in the controls. Plasma corticosterone concentration was increased (P less than 0.05) throughout the disease in both groups of calves that recoverd. These results indicate that the adrenal cortex of the neonatal calf can respond to the severe stressor influences and fluid-electrolyte losses of diarrhea.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Phase I pilot trial of the bispecific antibody MDXH210 (anti-Fc gamma RI X anti-HER-2/neu) in patients whose prostate cancer overexpresses HER-2/neu.

The goal of this study was to evaluate, in patients with prostate cancer, the toxicity profile and biologic activity of the bispecific antibody MDXH210, which has specificity for the non-ligand-binding site of the high-affinity immunoglobulin G receptor (Fc gamma RI) and the extracellular domain of the HER-2/neu proto-oncogene product. Patients with prostate cancer that expressed HER-2/neu were entered into a phase I dose-escalation trial of MDXH210. Patients received an intravenous infusion MDXH210 during a period of 2 h three times per week for 2 weeks and were monitored for toxicity. Pharmacokinetic and pharmacodynamic parameters were measured and included the biologic end points of monocyte-bound MDXH210, cytokine production, and clinical response. Seven patients were treated with MDXH210 doses ranging from 1 to 8 mg/m2. In general, MDXH210 was well tolerated, with only mild infusion-related malaise, fever, chills, and myalgias. No dose-limiting toxic effects were observed. Biologic effects included induction of low plasma concentrations of tumor necrosis factor-alpha and interleukin-6 observed immediately after MDXH210 infusion and 70% saturation of circulating monocyte-associated Fc gamma RI with MDXH210 at a dose level of 4 to 8 mg/m2. Five of six patients had stable prostate-specific antigen levels during the course of 40 days or more. Circulating plasma HER-2/neu levels decreased by 80% at days 12 and 29 (p = 0.03 and 0.06, respectively, by the Wilcoxon signed rank test). MDXH210 can be given safely to patients with HER-2/neu-positive prostate cancer in doses of at least 8 mg/m2. At the doses studied, biologic activity was demonstrated and characterized by binding of MDXH210 to circulating monocytes, release of monocyte-derived cytokines, a decrease in circulating HER-2/neu, and short-term stabilization of prostate-specific antigen levels.

Aged↗