Search PubMed⌕ Search

Biomedical subjects

A Martin

Publications and source records attributed to A Martin.

At least 883 records · Page 49Linked to original sources
PubMed1976

The effect of delta 9-tetrahydrocannabinol and LSD on the acquisition of an active avoidance response in the rat.

The course of active avoidance learning of rats in a symmetrical Y-maze under the influence of 1, 3, and 9 mg/kg of delta 9-THC i.p., and 5, 20, and mug/kg of LSD was investigated. Delta-THC in a dosage of 1 mg/kg had no effect on avoidance learning. Three to a lesser extent 9 mg/kg produced more rapid learning with a significantly better performance. Learning under delta 9-THC proved to be state-dependent. The withdrawal of delta 9-THC caused a decrease in the avoidance rate, which was dependent on the dosage. Upon renewal of the THC doses, the animals reattained their earlier preformance. In the course of the experiment there was rapid tolerance development, especially of the sedative properties of THC. LSD retarded the rate of acquisition of the active avoidance response. Whereas the control animals displayed over 80% successful active avoidance from the 14th session onwards, this was achieved by the LSD groups only after the 20th session. However, in contrast to the control group the LSD animals were able to increase their avoidance rate to over 90%, and this was maintained to the end of the experiment (a total of 24 sessions with LSD). The sudden withdrawal of LSD produced a fall in avoidance rate, which was dependent on the pervious training dosage; as with delta 9-THC state-dependent learning can also be assumed for LSD.

Animals↗
PubMed1976

Pressure changes in varicose veins.

Pressures in the superficial leg veins of 24 patients with varicose veins and 6 normal controls were studied. In the controls there was no rise in pressure in the veins on increasing the intra-abdominal pressure, but in the patients with varicose veins pressure rose significantly. Squatting was no better than sitting in preventing transmission of intra-abdominal pressure to the leg veins. It was concluded that the difference in the positions adopted for defaecation is not the cause of the wide variation in the geographical distribution of varicose veins.

Cough↗
PubMed1976

Preparation of subcellular fractions from rat liver: comparison of the Polytron with the Dounce homogenizer.

The PolytronR and Dounce homogenizers have been evaluated for preparation of homogenates of rat liver prior to isolation of subcellular fractions by differential centrifugation. Marker enzymes used to evaluate the subcellular fractions included cytochrome oxidase, monoamine oxidase, D-amino acid oxidase, acid phosphatase, glucose-6-phosphatase, ethyl morphine demethylase, and lactate dehydrogenase. No significant difference in the distribution of enzymes (percent recovery or specific activity) was observed between the two methods of homogenization. In addition, there were no significant differences in the ultrastructural appearances and respiratory control ratios of the mitochondrial fractions prepared by the two methods of homogenization.

Animals↗
PubMed1976

Effect of size on the function of three day hospitals: the case for the small unit.

The work load of three day hospitals attached to active departments of Geriatric Medicine was studied over a one-year period. A significant difference in the functional efficiency of the three units was noted. The smaller 12-place and 15-place units provided effective short-term rehabilitation, whereas the 28-place unit did not. Size seemed to be the major factor in the success or failure of a given unit. This study throws serious doubts upon the wisdom of a policy of building large day hospitals with all their accompanying problems of staffing and transport. An effective unit for out-patient rehabilitation can be provided with 10 to 15 places per day if the staff members are chiefly remedial therapists. In the districts studied, a provision of 0.5 place per 1,000 of the population aged 65 or older would have been sufficient to meet the perceived need for rehabilitation. However, this would not have been sufficient to satisfy the requirement for out-patient investigation and medical treatment on a day basis.

Chronic Disease↗
PubMed1976

Structural determination of the polysaccharide antigens of Neisseria meningitidis serogroups Y, W-135, and BO1.

The purified high molecular weight serogroup Y meningococcal polysaccharide contains equimolar proportions of D-glucose and N-acetylneuraminic acid and is partially O-acetylated. Carbon-13 nuclear magnetic resonance (NMR) studies, together with other chemical data, have indicated that the polysaccharide is linked only at C-6 of the D-glucose and C-4 of the sialic acid residues, all the linkages being in the alpha-configuration. The 13CNMR data also indicated that the Y polysaccharide is composed of an alternating sequence of these two different residues, and this was confirmed by its autohydrolysis where the major product was 4-O-alpha-D-glucopyranosyl-beta-D-N-acetylneuraminic acid. The W-135 polysaccharide differs from that of Y only in the absence of O-acetylation and in the configuration of one hydroxyl group of the disaccharide repeating unit. In this case autohydrolysis yielded 4-O-alpha-D-galactopyranosyl-beta-D-N-acetylneuraminic acid as the major product. Structural evidence indicates that the BO and Y polysaccharides are identical. Methanolysis of the Y polysaccharide yielded in addition to the methyl glycosides of glucose and sialic acid, a 9-O-acetyl derivative of the latter. This derivative was formed during the re-N-acetylation process and its formation was mainly due to the presence of sodium ions in the original polysaccharide.

Antigens, Bacterial↗
PubMed1976

[Radio-electrogastro-enterographic correlations (author's transl)].

Recording of the electro-gastro-enterogram (E.G.E.G.) and the simultaneous taking of a 70 mm ampliphotography series shows the high degree of correlation between E.G.E.G. and peristaltis, with characteristic waves for each part of the digestive tract, both in the normal condition as well as in certain pathological states. The future and role of the E.G.E.G. appear very promising, on the one hand by virtue of its simplicity and secondly because of the information it is capable of providing from a functional viewpoint. In no case, however, can it replace the precise nature of radiological images.

Action Potentials↗
PubMed1975

The Butler report.

Explore the source record for details and available documents.

Commitment of Persons with Psychiatric Disorders↗
PubMed1975

[Inhibition of antigenic competition by immunostimulants].

The diminution of immune response against SRBC induced in mice, by a prior injection of HRBC was counteracted by addition of certain immunostimulants to SRBC. The intensity of inhibition of antigenic competition was related to the quantity of immunostimulant added to SRBC. Some immunostimulants (B. abortus, lipopolysaccharide) were more active than others (C. parvum, Poly I : C). To inhibit antigenic competition immunostimulant had to be injected after or in mixture with SRBC never before.

Animals↗
PubMed1975

[Diagnosis of human active or latent human brucellosis by lymphocyte transformation. Inhibition of leukocyte migration and passive hemagglutination. Possible interference between brucellosis and some mental disorders].

Passive hemagglutination tests (H.T.), involving the coating of a soluble B. abortus antigen onto sheep red blood cells through chromium chloride, were always negative in non-brucellic subjects. Positive H.T., even at low titers (1:50), were associated with positive specific lymphoblastic (T.T.L.) and inhibition of leucocyte migration (I.M.L.) tests in 13 patients. These 3 tests were negative in 17 control brucellosis-free individuals. Positive H.T. confirmed a clinical diagnosis of brucellosis in 27 patients with dubious or negative responses to classical tests. Low positive (1:50, 1:100) H.T. may correspond to Brucella primary-infection or to a quiescent chronic infection, and higher titers to clinically active brucellosis. There is a correlation between cellular immunity tests (T.T.L., I.M.L.) and passive hemagglutination test. Furthermore, 39/88 women hospitalized in psychiatric wards were positive to H.T., and 6 of them were also highly positive to complement fixation and tube agglutination tests. Three T.T.L. and I.M.L., performed on samples from 3 H.T. (1:50) positive patients, were positive. These 30 patients were classified as depression or severe anorexia.

Adult↗