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Biomedical subjects

J Armstrong

Publications and source records attributed to J Armstrong.

At least 199 records · Page 11Linked to original sources
PubMed1980

Adhesive and non-adhesive membrane domains of amphibian embryo cells.

Superficial blastomeres of mid-cleavage stage amphibian embryos (32- and 64-cell stage) display regional cell-surface differences in adhesiveness. The cells are adhesive on the lateral and basal cell surfaces and non-adhesive on the apical surface. These adhesive differences are maintained by single cells which have been dissociated from the intact embryo. Pigmentation differences afford a means of distinguishing apical surface from basal/lateral surface in dissociated cells. The apical surface is underlain by melanin granules and so appears dark, whereas the lateral and basal surfaces lack pigment and are white. Scanning electron-micrograph observations of isolated superficial cells reveal striking morphological differences between the adhesive and non-adhesive regions. The apical (non-adhesive) portion of the cell surface has a convoluted appearance and is almost entirely devoid of microvilli. The lateral and basal (adhesive) surfaces lack the convolutions of the apical surface and bear scattered microvilli. The isolated superficial cells continue to divide in culture. The cells display a unilateral or one-sided furrow which begins in the basal surface and progresses toward the apical surface. The plane of cleavage of most of the cells is oriented such that the pigmented cap is bisected, with very few cells having the plane of the furrow pass parallel to the apical surface. The direction of furrowing in the isolated cells from the 32- to 64-cell embryo represents a direction of furrow progression in the intact embryo from the interior to the surface. Since the early cleavages are initiated at the surface and progress into the interior, it is suggested that a reversal in direction of furrowing occurs by mid-cleavage stages.

Animals↗
PubMed1980

Suicide in Brisbane--a retrospective psychosocial study.

A consecutive series of 135 suicides is described, this being the total which occurred during one year in Brisbane from 1 March 1973 to 28 February 1974, resulting in a rate of 16 per 100,000. The clinical and social characteristics of the suicides are described. Important contributing factors were depressive illness (55%), physical illness (52%), and drug dependency (34%). About half of the suicides were taking prescribed medication and about a third had been in contact with a doctor shortly before death. Social isolation or loss appeared to contribute to the suicide risk. The study confirms the importance of the recognition and treatment of depressive illness in attempting to prevent suicide and draws attention to the significant contribution of physical illness, especially when affecting the nervous system or gastrointestinal tract, and the importance of the role of alcohol and/or barbiturate dependency.

Adult↗
PubMed1978

Mastectomy in a large public hospital.

Thirty women undergoing mastectomy for carcinoma of the breast in a large teaching hospital were interviewed. All indicated a very real need to discuss their experiences, and felt that the interview had been beneficial to them. Most had found the "lump" themselves--but often described it as a "hardness", a "ridge", or a "thickening". More than half felt that the counselling afforded to them had been inadequate--especially in the realm of sexual adjustment--but, if their marriages had been stable before operation, subsequent deterioration was unlikely. The threat of malignancy, rather than that of breast loss, was uppermost in the minds of most patients. It should not be assumed that postmastectomy problems do not exist because patients do not mention them, especially in large busy follow-up clinics, where privacy may be inadequate. If doctors are unable or unwilling to afford this service to their mastectomy patients, it may be necessary to delegate it to other health professionals and mastectomy volunteers.

Adult↗
PubMed1978

Psychological construing and thought disorder: another test of the 'difficulty' hypothesis.

Two versions of the grid test of thought disorder were derived which used similar elements, and were of equal difficulty, but one of which employed psychological, and the other non-psychological, constructs. They were administered to thought-disordered schizophrenic patients and to psychiatric and normal controls. On one measure (consistency), although not on the other (intensity), the results strongly supported the hypothesis that thought-disordered patients are maximally disordered in the area of psychological construing. The results support those of an earlier study (McPherson et al. 1975) and are compatible with those theories which postulate a role for social factors in the aetiology of thought disorder.

Adult↗
PubMed1978

Battered wives: a controlled study of predisposition.

The possibility that women who are battered by their husband are predisposed to this treatment is examined in a controlled study of 30 such women and 30 control subjects. A number of father-related items distinguished between the two groups: in the battered group fathers had more mental illness, were more violent and tended to be more strict. Battered women more often witnessed violence by their husband to other prior to marriage. All participants were rated for hostility using the Hostility and Direction of Hostility Questionnaire (HDHQ). Both groups emerged as significantly and globally more hostile than a group of normal subjects.

Adult↗
PubMed1978

Inter-batch quality differences in purified human prolactin.

During the past four years, we secured six batches of purified human prolactin for iodination by the same lactoperoxidase technique. Two of these batches gave us more satisfactory results in terms of assay sensitivity and consistency than did the others, regardless of the antiserum used. Gel filtration of 125I-labeled hormone revealed that these two batches were composed of at least 55% "small" prolactin while the other four batches contained from 20 to 68% "big" prolactin. This qualitative difference was the most important contribution to assay discrepancies.

Humans↗
PubMed1977

Treatment of gonorrhea with trimethoprim-sulfamethoxazole.

The following regimens were randomly administered to 271 men with gonococcal urethritis: 4.8 X 10(6) units of aqueous procaine penicillin G intramuscularly plus 1 g of probenecid orally (APPG); nine tablets of trimethoprim-sulfamethoxazole (TMP-SMZ; 720 mg of TMP and 3,600 mg of SMZ), orally as a single dose (TMP-SMZ-9); and 12 tablets of TMP-SMZ (960 mg of TMP and 4,800 mg of SMZ) orally as two doses of six tablets taken at a 6-hr interval (TMP-SMZ-12). The failure rates of the APPG, TMP-SMZ-9, and TMP-SMZ-12 regimens were 4%, 23%, and 19%, respectively. APPG was significantly more effective (P less than 0.05) than TMP-SMZ-9 or TMP-SMZ-12. Isolates of Neisseria gonorrhoeae from treatment failures as compared to those from treatment successes were significantly more resistant to SMZ (P less than 0.01) and to the TMP-SMZ combination in a ratio of 19 parts SMZ to one part TMP (P less than 0.05). Minimal inhibitory concentrations of SMZ, TMP, TMP-SMZ, and penicillin G showed positive correlation coefficients.

Administration, Oral↗
PubMed1976

The ionization of phenolic amines, including apomorphine, dopamine and catecholamines and an assessment of zwitterion constants.

The dissociation constants of many phenolic amines, including benzylamines, phenethylamines, phenylethanolamines, phenylpropylamines, catecholamines, and apomorphine have been measured by potentiometric titration at 25 degrees C. Measurements have also been made with many of their methoxy derivatives and with series of phenolic quaternary ammonium salts. Some compounds were also studied at 37 degrees C. 2 Usually at least five titrations were made with each compound and Debye--Hückel theory was applied to convert concentrations to activities but the estimates of pKa were not constant and found to increase with increasing concentration. The range studied was usually 5-15 mM and a least-squares line-fit, based on the empirical assumption that pKa varies with (concentration)1/2, has been used to calculate values for 10 mM solutions and to extrapolate to infinite dilution and to 100 mM. The dependence of pKa on concentration was much less at 37 degrees C than at 25 degrees C. 3 At 37 degrees C the pKa values of many biologically interesting compounds in the group, dopamine, noradrenaline, adrenaline and isoprenaline, coryneine (the trimethylammonium derivative of dopamine) and apomorphine are within 1 log unit of physiological pH, indicating the presence of a significant proportion of either the zwitterion or of the uncharged phenolic amine. 4 Zwitterion constants have been estimated from the pKa values of the phenolic amines and those of their methoxy and quaternary trimethylammonium analogues. Zwitterion formation does not appear to be associated with activity at alpha-adrenoceptors and probably not with activity at beta-receptors. The active species seems likely to contain the unionised phenolic group but at dopamine receptors this may be in the uncharged phenolic amine rather than in the phenolic ammonium salt.

Amines↗
PubMed1975

Use of a standardized psychiatric interview in mentally handicapped patients.

This study attempted to assess the applicability of the Clinical Interview Schedule (Goldberg et al., 1970) to mentally handicapped patients in a hospital. Twenty-seven patients were rated simultaneously by three raters. Of the 31 items assessed for reliability, 11 were completely satisfactory, 8 were satisfactory, 6 unsatisfactory and 6 'not proven'. Ratings made by all raters for overall severity of psychiatric illness correlated significantly with similar ratings made by the consultants responsible for the patients.

Behavior↗