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Biomedical subjects

S Johnson

Publications and source records attributed to S Johnson.

At least 523 records · Page 29Linked to original sources
PubMed1981

Use of the FAB criteria for the diagnosis of acute erythroleukaemia (AEL).

The criteria proposed by the French-American-British (FAB) Group for the diagnosis of acute erythroleukaemia (AEL), including the requirement for greater than or equal 30% marrow myeloblasts, were used in a review of patients with erythroleukaemia. Ten patients with AEL were identified, and a further twelve patients with marrows suggestive of AEL but having less than 30% myeloblasts were classified as having refractory anaemia with excess of blasts (RAEB). The AEL patients had a poor prognosis, poor response to chemotherapy, and none showed evolution to myeloblastic or monoblastic leukaemia. In contrast, the patients with RAEB appeared to survive longer, respond better to chemotherapy, and several evolved into typical myelogenous leukaemia. The FAB criteria subdivides patients with erythroleukaemia into groups with apparent clinicopathological and prognostic differences. Further studies using these or equally strict criteria are required.

Acute Disease↗
PubMed1981

Comparison of spot esculin hydrolysis with the PathoTec strip test for rapid differentiation of anaerobic bacteria.

The ability of several anaerobic bacteria to hydrolyze esculin to esculetin is used by clinical microbiologists and taxonomists in the differentiation and identification of both gram-positive and gram-negative microorganisms. Conventional methods used for determining esculin hydrolysis by anaerobic bacteria require 24 to 48 h for completion. In this paper we evaluate two procedures which yield rapid results. A total of 738 anaerobic bacteria were used in this study. A total of 99% of the esculin-hydrolyzing anaerobic bacteria gave positive results with the spot test in 1 h, whereas the other test method, the PathoTec strip test (General Diagnostics, Morris Plains, N.J.), required 4 h for 96% of the strains tested to yield positive reactions. Both tests showed a 100% specificity when compared with the standard broth test and are easy to perform, accurate, and economical. The spot test is superior to the PathoTec strip test in yielding results more rapidly.

Anaerobiosis↗
PubMed1981

Overview: deinstitutionalization of psychiatric patients, a critical review of outcome studies.

The authors performed a critical review of experimental studies on the outcomes for psychiatric patients of 1) alternatives to hospital admission, 2) modifications of conventional hospitalization, and 3) alternatives to continued long-term hospitalization. The internal validity of many of the studies was compromised by shortcomings in design and performance and generalizability limited by selection of patient populations. With these qualifications experimental alternatives to hospital care of patients have led to psychiatric outcomes not different from and occasionally superior to those of patients in control groups. This conclusion is best supported for alternatives to admission and for modifications of conventional hospitalization. The available studies do not permit firm conclusions regarding alternatives to continued long-term hospitalization of chronically ill patients or for a critical analysis of the optimal management of specific subpopulations of psychiatric patients. Satisfactory deinstitutionalization appears to depend on the availability of appropriate programs for care in the community.

Adult↗
PubMed1981

Immune deficiency in fetal alcohol syndrome.

In a review of 13 documented cases of fetal alcohol syndrome (FAS), an increased incidence of life-threatening bacterial infections as well as a propensity to minor infections was observed. Five of 13 patients had had at least one episode of pneumonia, two had meningitis, and one had sepsis. A comprehensive immunologic evaluation of FAS was completed, and results were compared to an age-matched control group of children with intrauterine growth retardation without FAS. Children with FAS were shown to have decreased E rosette-forming lymphocytes (35 +/- 5% versus 55 +/- 5% or 1328 +/- 274 versus 2333 +/- 112 per mm3), low EAC rosette-forming lymphocytes (15 +/- 2% versus 18 +/- 1% or 524 +/- 109 versus 740 +/- 75 per mm3), and diminished mitogen-induced stimulation responses to mitogens: 31616 +/- 5337 versus 58076 +/- 4455 cpm for phytohemagglutinin, 17582 +/- 5436 versus 35018 +/- 5346 for pokeweed mitogen, and 32460 +/- 7044 versus 54996 +/- 5531 for concanavalin A, P less than 0.05. Nine patients had dysgammaglobulinemia, FAS subjects also had a marked eosinophilia (624 +/- 154 versus 72 +/- 27 mm3). Other parameters of immune function including absolute lymphocyte and neutrophil counts, total hemolytic complement, delayed cutaneous hypersensitivity, and nitroblue tetrazolium dye reduction assays, were not different from control children. Impairment of immunity may explain an increased susceptibility to infection in FAS.

Antibody Formation↗
PubMed1981

Effects of experimental diabetes on the essential fatty acid-deficient rat.

An evaluation of the EFAD syndrome in rats rendered diabetic with either alloxan or streptozotocin was performed. Diabetic rats fed an EFA-deficient diet for 7 or 13 weeks were less severely EFA-deficient than were nondiabetic rats fed EFA-deficient diet, as judged by dermal symptoms or by biochemical parameters such as the ratio of 20:3 omega 9/20:4 omega 6 (T/T ratio) and total fatty acids derived from linoleic acid. The T/T ratios of liver PL of diabetic EFA-deficient rats were lower than those of deficient control rats, and the ratios varied inversely with the blood glucose concentrations. The product/precursor ratios, arachidonic acid/linoleic acid, in liver PL were higher in diabetic deficient rats than in deficient control rats. Analysis of liver and heart PLs revealed higher arachidonic acid levels in the diabetic deficient rats than in the EFA-deficient controls, perhaps because of different growth rates. The activities of the delta 5, delta 6, and delta 9 desaturases were evaluated in liver microsomal systems. The delta 9 desaturase was depressed in diabetic rats in agreement with literature reports. The delta 6 desaturase, however, was slightly increased. The relative levels of delta 5, delta 6 and delta 9 desaturation products in liver and heart PLs did not parallel the measured desaturase activities of liver microsomes.

Animals↗
PubMed1980

Foot rot of pigs: the influence of biotin supplementation on foot lesions in sows.

A herd of 116 sows with a high frequency of foot lesions and lameness was divided into two groups, A and B. Group B was supplemented with 1160 microgram per day of biotin in pregnancy and 2320 microgram per day in lactation, over a 12-month period. No improvement occurred in the condition of the feet or skin. Gilts introduced as replacements to the herd were allocated alternately to the groups. Those receiving biotin (group B) showed significantly fewer lesions of heel erosion, white-line, heel bruising and "corn", and the severity and number of lesions of the lateral hind claws were also significantly improved.

Animals↗
PubMed1980

Stimulation of hormone-responsive adenylate cyclase activity by a factor present in the cell cytosol.

1. Homogenates of whole tissues were shown to contain both intracellular and extracellular factors that affected particulate adenylate cyclase activity in vitro. Factors present in the extracellular fluids produced an inhibition of basal, hormone- and fluoride-stimulated enzyme activity but factors present in the cell cytosol increased hormone-stimulated activity with relatively little effect on basal or fluoride-stimulated enzyme activity. 2. The existence of this cytosol factor or factors was investigated using freshly isolated human platelets, freshly isolated rat hepatocytes, and cultured cells derived from rat osteogenic sarcoma, rat calvaria, mouse melanoma, pig aortic endothelium, human articular cartilage chondrocytes and human bronchial carcinoma (BEN) cells. 3. The stimulation of the hormone response by the cytosol factor ranged from 60 to 890% depending on the tissue of origin of the adenylate cyclase. 4. In each case the behaviour of the factor was similar to the action of GTP on that particular adenylate cyclase preparation. 5. No evidence of tissue or species specificity was found, as cytosols stimulated adenylate cyclase from their own and unrelated tissues to the same degree. 6. In the human platelet, the inclusion of the cytosol in the assay of adenylate cyclase increased the rate of enzyme activity in response to stimulation by prostaglandin E1 without affecting the amount of prostaglandin E1 required for half-maximal stimulation or the characteristics of enzyme activation by prostaglandin E.

Adenylyl Cyclases↗
PubMed1980

Distribution and biosocial correlations of blood pressure levels in Johannesburg blacks.

Blood pressures were measured in a sample of Johannesburg Blacks consisting of 5 018 men and 5 028 women attending the local Labour Bureau. Blood pressure levels correlated positively with age and body mass and were higher in males than females when weight was taken into account. Hypertension was common in both sexes and at most ages; in the 4th decade about one-third of men and women had phase 4 diastolic pressures greater than 90 mmHg. Correlations of blood pressure with a number of social variables were generally unimpressive. There was some evidence that blood pressure was inversely related to educational status and was higher in young adults who (a) lived apart from their families compared with those who lived in family units, and (b) grew up in a rural area and then migrated to Johannesburg compared with those who had lived in Johannesburg all their lives.

Adolescent↗
PubMed1980

The effects of race and social class on clinical judgment.

Asked 61 male clinical psychologists (21 blacks and 40 whites) to assess case histories that were presented to them to determine whether racial or social class biases could be detected. In order to avoid the apparent artificial results or weak interpretations of past research, only cases with concurrently validated diagnoses and 4-year follow-up were used. An equal number of positive and negative clinical outcomes were included. Diagnosis, disposition, and rated severity were studied. The following results were found: (1) diagnosis for all psychologists was guided by case characteristics, not bias; (2) severity was related strongly to diagnosis; (3) disposition followed judgments of severity and diagnosis, not bias. The question was raised whether clinical investigators may not have overdramatized bias in psychodiagnosis and clinical judgment.

Alcoholism↗
PubMed1980

The effect of isomeric trans-18:1 acids on the desaturation of palmitic, linoleic and eicosa-8,11,14-trienoic acids by rat liver microsomes.

The inhibitory effects of the positional isomers of trans-18:1 acids on the desaturation of palmitic acid to palmitoleic (delta 9-desaturase), linoleic to gamma-linolenic (delta 6-desaturase) and eicosa-8,11,14-trienoic to arachidonic acid (delta 5-desaturase) were investigated. These trans-18:1 acids were found to be inhibitory for the microsomal delta 6-, delta 9- and delta 5-desaturases of rat liver. The position of the double bond in the trans-18:1 acids seems to be important in determining the degree of inhibition. At inhibitor/substrate ratio of 3:1, the delta 6-desaturase was most strongly inhibited by trans-delta 3, -delta 4, -delta 7 and -delta 15-18:1 isomers, whereas the delta 9-desaturase was most strongly inhibited by trans-delta3, -delta 5, -delta 7, -delta 10, -delta 12, -delta 13 and -delta 16 isomers. At inhibitor/substrate ratio of 6:1, the delta 5-desaturase was most strongly inhibited by delta 3-, delta 9-, delta 13- and delta 15-isomers. When 18:0 was added to the incubations of 16:0, 18:2 and 20:3 at the same I/S ratios used for the trans-18:1 acids, weak inhibition for delta 9- desaturase and no inhibition for delta 5- and delta 6-desaturases was observed.

8,11,14-Eicosatrienoic Acid↗
PubMed1980

Cell surface A, B, or O(H) blood group antigens as an indicator of malignant potential in stage A bladder carcinoma.

The major blood group antigens A, B or O(H) are present on normal bladder epithelium. The presence or absence of these antigens on the cell surface of bladder tumors has been determined in a retrospective longitudinal study using biopsy material from 322 patients who fit the following criteria: 1) the patient presented initially with a superficial bladder tumor, 2) the patient had followup examination for at least 5 years or until evidence of tumor invasion of bladder muscle and 3) the paraffin-embedded tumor specimens were still available. Of 80 patients with stage A tumors that subsequently became invasive 71 (88 per cent) showed deletion of A, B or H antigens from the original superficial tumor. On the other hand, of 146 patients who had no recurrence of superficial tumor for at least 5 years 127 (87 per cent) retained A, B or H antigens. Of 96 patients who had 1 or more superficial recurrences 87 (90 per cent) retained antigens on the initial and subsequent tumors. Analysis of transitional cell surface antigens should help in the identification of those patients with superficial disease who are at greatest risk for invasive bladder cancer.

ABO Blood-Group System↗