Biomedical subjects
Publications and source records attributed to D A Smith.
In the previous article, the rigid use of the Friedman Curve, breathing techniques, and other management options for the second stage of labor were examined. This article concentrates on the affect of maternal positioning, on the length of the second stage of labor, and summarizes the contents of that former article and this one.
Millions of Americans suffer needlessly from the embarrassment and discomfort of urinary incontinence. Understanding the problem is the first step in helping these patients regain control.
Fifty cases of malignant ascites were studied to determine what factors influenced outcome after peritoneovenous shunt. There were 36 women and 14 men. The five most common tumor types were colon, breast, gastric, pancreatic, and unspecified adenocarcinoma. Multivariate analysis between those patients surviving longer than 7 weeks (n = 20) and those who died in less than 7 weeks (n = 30) showed that women did uniformly better than men, even excluding the "female malignancies" (P less than 0.01). An elevated white blood cell count (WBC) and low platelets also were strong predictors of poor outcome (P less than 0.5 for difference in means between the two groups). Patients with pancreatic cancer and ascites fared poorly (80% mortality by 7 weeks) as did those with colon cancer (73% mortality by 7 weeks). By contrast, 50 per cent of the patients with breast and gastric cancer lived more than 7 weeks. Twelve patients had a LaVeen shunt placed, compared with 38 who had a Denver shunt. Fifty per cent of the La Veen shunts failed, with a mean time to failure of 69 days (P less than 0.01). Shunt failure, however, had no influence on overall survival.
We examined the stability of human lactate dehydrogenase (EC 1.1.1.27) isoenzyme 5--purified to a specific activity of about 400 kU/g--when lyophilized in a buffered, stabilized matrix of bovine albumin. This isoenzyme was prepared with a final activity of about 500 U/L and stored at -20, 4, 20, 37, and 56 degrees C for as long as six months. This isoenzyme decayed with approximate first-order kinetics, with an estimated half-life at -20 degrees C of about 475 years. Stability of reconstituted samples stored at 20 or 4 degrees C was poor, suggesting that the reconstituted material should be used without delay; material stored at -20 degrees C showed excellent stability for 15 days. We propose that such preparations might be further investigated as standards for use in electrophoresis of lactate dehydrogenase isoenzymes.
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Quantitative analysis of responses to amino acids in mouse cortical slices has indicated that the antagonists kynurenate and 2-amino-5-phosphonopentanoic acid distinguish between ibotenate and both N-methyl-D-aspartate (NMDA) and quinolinate. This result is consistent with the existence of NMDA-receptor subtypes.
1. The effects of 2-amino-5-phosphonovalerate and kynurenate, either alone or in combination, were tested on responses evoked by the excitatory amino acid agonists quinolinate, ibotenate, N-methyl-D-aspartate and N-methyl-DL-aspartate by use of an in vitro preparation of mouse neocortex and artificial cerebrospinal fluid nominally free of magnesium. 2. Schild plots for 2-amino-5-phosphonovalerate, using each of the excitatory amino acids, were linear and had a slope not significantly different from one. The apparent pA2 values for 2-amino-5-phosphonovalerate using each of the excitatory amino acids were 4.98 (quinolinate), 5.00 (N-methyl-DL-aspartate), 4.92 (N-methyl-D-aspartate) and 5.05 (ibotenate). The apparent pA2 obtained using ibotenate was distinct from that of N-methyl-D-aspartate but there were no significant differences between pA2 estimates for quinolinate, N-methyl-D-aspartate or N-methyl-DL-aspartate. 3. Schild plots for kynurenate, using each of the excitatory amino acids, were linear and had a slope of 1.36 +/- 0.03, significantly greater than one. The estimated apparent pA2 values for kynurenate were 3.65 (quinolinate), 3.71 (N-methyl-DL-aspartate), 3.65 (N-methyl-D-aspartate) and 3.89 (ibotenate). The apparent pA2 obtained using ibotenate was distinct from that of the other agonists. 4. Experiments using combinations of 2-amino-5-phosphonovalerate and kynurenate indicated that both antagonists apparently acted competitively at receptors activated by ibotenate or by quinolinate. 5. These results indicate that ibotenate acts at a site distinct form that of quinolinate, N-methyl-D-aspartate and N-methyl-DL-aspartate.
1. The equivalent circuit of the cortical slice preparation has been analysed to show that the measured d.c. voltages can be used to estimate the Hill coefficient for ligands acting on the pyramidal cell bodies. 2. The Gaddum-Schild equation for agonist-antagonist interactions has been modified for applications in which the Hill coefficient is not equal to 1. 3. The equations obtained have been applied to recent data of Burton et al. (1988). The results provide evidence for a bimolecular action of the agonists N-methyl-D-aspartate (NMDA) and quinolinic acid and the antagonists kynurenic acid and 2-amino-5-phosphono-pentanoic acid at NMDA receptors on mouse neocortical pyramidal cells.
Complete reproductive tracts of 30 female African elephants (5-53 years), obtained during a population reduction procedure, were examined. The reproductive tracts were palpated in situ via the urogenital canal. A plastic speculum (1.3 X 170 cm) was introduced into the canal and dye was injected to simulate the procedure for artificial insemination. The lengths of reproductive tracts (from the vulva to the ovary) ranged from 120 to 358 cm. The length increased with the size and age of the animal. There was a membranous constriction (hymen) with an orifice, less than 2 cm in diameter, between the urogenital canal and the vagina, in 4 primigravid and in all 13 nulliparous elephants. The vaginal orifice of 13 multiparous elephants consisted of ragged folds of mucous membrane surrounding a single opening, 5-19 cm in diameter. The ages at first conception of 4 pregnant elephants with intact hymenal membranes were 10, 12, 13 and 14 years. The hymen was not penetrated as a result of intromission and therefore the site of ejaculation would have been in the urogenital canal of the 4 primigravid elephants.
1. The consequences of metabolic transformation on lipophilicity have been considered using the terms log P (partition coefficient) and log D (distribution coefficient). 2. Transformations which result in no change in the degree of ionisation can be readily predicted by the use of fragmental constants and log P. 3. If metabolism alters the degree of ionization then the distribution coefficient, log D, at physiological pH is a more appropriate term to use. Intuitive empirical observations may be incorrect and lead to false assumptions about the lipophilicity or water solubility of metabolites. 4. Metabolism may form zwitterionic molecules. These metabolites need special consideration since their penetration into lipid phases may be greater than expected.
Using activity analysis, occupational therapists structure group activities to meet the needs and goals of group members. This study compared the effects of project group structure (subjects participate together on a common task) with parallel group structure (subjects each have a task) in a sample of healthy seniors (32 women and 9 men). Subjects randomly assigned to either experimental condition made creative and imitative collages in a counter-balanced order. Time-sampled observations revealed that project group subjects talked and looked at others significantly more than parallel group subjects. On-task and laughing behaviors were also measured, but results were inconclusive. Project group subjects rated their activities higher on the action factor of the Osgood semantic differential (OSD) than did parallel group subjects, but there were no other differences on the OSD or on MacKenzie's Group Climate Questionnaire. Nor were there significant main effects between the creative collage and the imitative collage. Results are discussed both in terms of group task structure as an occupational therapy tool and in terms of methodologies for future activity analysis research.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.