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Biomedical subjects

M Smith

Publications and source records attributed to M Smith.

At least 1,333 records · Page 74Linked to original sources
PubMed1978

[A method for testing susceptibility of Haemophilus influenzae to co-trimoxazole (author's transl)].

Various methods for determining the activity of co-trimoxazole against haemophilus influenzae have been compared. The results were cortically influenced by antagonistic substances in the medium. The content of p-aminobenzoeacid and thymidine in the medium should be as low as possible. The antagonistic influences are compensated by lysed horseblood, which contains thymidine-phosphorylase. Haeminchloride and nicotinamide adenine dinucleotide (NAD) are better growth-factors than other poorly defined preparations (Supplement C, Fil-des-Enrichment, Iso-VitaleX). For the determination of the minimal inhibition concentration (MIC) we propose the microtiter technique. Likewise a modified agar diffusion test can be recommended for screening purposes. Of the 143 haemophilus influenzae strains tested against co-trimoxazole 134 (94%) were sensitive.

4-Aminobenzoic Acid↗
PubMed1978

Effects of bromocriptine mesylate on the composition of the mammary secretion in non-breast-feeding women.

A double-blind trial was performed on 26 women, who had elected not to breast-feed their infants, to determine the effect of bromocriptine mesylate (2.5 mg twice daily for 14 days postpartum) on the composition of the mammary secretion during lactogenesis. Mammary secretion (less than 5.0 ml) was collected from each breast of each woman at daily intervals during the 14-day treatment period and the progressive changes in the concentration of the milk constituents, lactose, alpha-lactalbumin, serum albumin, total protein, lactoferin, IgA, IgG, sodium and potassium were determined. The degree of milk leakage and breast engorgement were also assessed. Both the subjective assessments and the changes in the concentration of the milk constituents demonstrated that lactogenesis occurred between about Day 2 and Day 5 postpartum in the placebo group (in the absence of the suckling stimulus) but was suppressed in the bromocriptine-treated group.

Breast↗
PubMed1977

The effect of long-term stimulation of fast muscles on their blood flow, metabolism and ability to withstand fatigue.

Chronic stimulation of fast rabbit muscles (tibialis anterior, extensor digitorum longus and the peroneal muscle group) at a frequency naturally occurring in nerves to slow muscles increased their ability to withstand fatigue. Isometric tension decreased during a 10-min period of contractions at 4 Hz by 75% in control muscles, but only 55% in muscles chronically stimulated for 4 days, and 23% in muscles stimulated for 28 days. Chronic stimulation had little effect on resting blood flow, oxygen or glucose consumption. The output or consumption of lactate and free fatty acids (FFA) at rest were also unaffected. The glycogen content was regularly increased, and was apparent after only 2 days of stimulation. The activity of fatty acid activating enzyme was increased after 28 days. During a 10-min period of isometric contractions at 4 Hz, there was a markedly greater increase in blood flow and oxygen consumption in muscles stimulated for 14-28 days than in control muscles; lactic acid output was lower in muscles stimulated for 28 days, and the uptake of FFA was significantly higher. It is therefore suggested that muscles chronically stimulated for 14-28 days use fats as the main source of energy during isometric contractions. The predominantly oxidative metabolism is probably facilitated by the higher density of capillaries. The latter also enables more efficient delivery of oxygen, and therefore smaller fatiguability, already after 4 days of chronic stimulation.

Animals↗
PubMed1977

Nucleotide sequence of bacteriophage phi X174 DNA.

A DNA sequence for the genome of bacteriophage phi X174 of approximately 5,375 nucleotides has been determined using the rapid and simple 'plus and minus' method. The sequence identifies many of the features responsible for the production of the proteins of the nine known genes of the organism, including initiation and termination sites for the proteins and RNAs. Two pairs of genes are coded by the same region of DNA using different reading frames.

Base Sequence↗
PubMed1977

Immunoglobulin-like messenger RNA in a mouse T cell lymphoma.

RNA-driven complementary DNA (cDNA) hybridization experiments have been carried out in order to detect complementary sequences in RNA prepared from a mouse T cell lymphoma line (EL4). In conditions where efficient hybridization of L-chain cDNA with homologous P3 myeloma mRNA was observed, poor hybridization was observed with EL4 mRNA unless a low criterion of hybrid formation was employed (i.e. hydroxyapatite fractionation). The hybrid formed between EL4 mRNA and L-chain cDNA was found to melt about 5 degrees C below the homologous hybrid indicating that the sequence detected in EL4 mRNA is similar but not identical with the P3 mRNA sequence. However, a similar sequence was detectable in a Clambda-producing myeloma cell line but in this line the concentration of the sequence was found to be an order of magnitude lower than in EL4 cells.

Base Sequence↗