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Biomedical subjects

W Johnson

Publications and source records attributed to W Johnson.

At least 235 records · Page 13Linked to original sources
PubMed1975

Bacterial growth inhibition by amniotic fluid. III. Demonstration of the variability of bacterial growth inhibition by amniotic fluid with a new plate-count technique.

The ability of 50 human amniotic fluid samples to inhibit the growth of Escherichia coli was measured with a new semimicro plate-count technique. A range from bacterial growth-sustaining fluid to bactericidal fluid was observed. When the inhibitory capacities of the fluid samples were correlated with gestational age, a progressive increase was obtained with maximum inhibitory capacity at 36 to 40 weeks. All fluid samples obtained before 20 weeks' gestation were capable of supporting bacterial growth. Fluid samples of 36 to 40 weeks' gestation were all bactericidal or bacteriostatic. More variability in inhibitory capacity was seen after 40 weeks, with an over-all loss of inhibition observed.

Amniocentesis↗
PubMed1975

Bacterial growth inhibition by amniotic fluid. IV. Studies on the nature of bacterial inhibition with the use of plate-count determinations.

Bacterial growth inhibition in amniotic fluid is associated with a compound or class of compounds which resembles antibacterial cationic peptides. The inhibitor studied in amniotic fluid is sensitive to treatment with monobasic and dibasic potassium phosphate, and the inhibitory activity of amniotic fluid is lost following adsorption onto bentomite. The inhibitory component in amniotic fluid interacts with bacterial cells by adsorption or is internalized by viable cells only. The inhibitory quality of amniotic fluid is not destroyed by heating to 100 degrees C. for 15 minutes, and this heat-stable inhibitory activity is associated with the compound or compounds which are phosphate sensitive. A possible mode of antibacterial action which is consistent with the data presented is discussed.

Adsorption↗
PubMed1975

Integrated programme of dialysis and renal transplantation. Results in 155 patients.

155 patients were referred for treatment of irreversible renal failure between Jan. 1, 1970, and Oct. 31, 1974. 8 (5%) patients were not accepted for treatment. An integrated programme of dialysis and transplantation (based on finding a cadaver transplant for every patient) has achieved an actuarial survival-rate of 88% at 1 year and 79% at 4 years. Of those surviving at 4 years, 85% are maintained by a functioning transplant. Only 4/122 transplants have been from living related donors. It is suggested that these results demonstrate that cadaveric transplantation, closely integrated with dialysis, offers an acceptable chance of life and full rehabilitation while not demanding from the community an unacceptable percentage of health resources.

Adolescent↗
PubMed1975

Capsular and vascular invasion: important prognostic factors in Wilms' tumor.

The influence of capsular and vascular invasion on prognosis was determined retrospectively in 52 children with Wilms' tumor. Local recurrence was more prevalent (0.26) in patients with rupture or capsular invasion than in any other group. Inadequate postnephrectomy irradiation or infiltration of the liver by nephroblastoma cells appeared to be predisposing factors in the development of these reccurrences. Of the 26 patients with gross or microscopic vascular invasion, 13 developed metastasis. This proportion was significantly higher than in patients without vascular involvement (p less than 0.05). These observations emphasize the importance of microscopic detection of capsular and vascular invasion in staging of Wilm's tumor.

Child↗
PubMed1975

Neonatal androstenedione and adult sexual behavior in golden hamsters.

Male rats castrated and given androstenedione neonatally can show high levels of both masculine and femine copulatory behavior in adulthood. In the present study, intact female and male hamsters castrated at birth were treated for their first 20 days with oil, free testosterone, or androstenedione. All neonatal androgen treatments mimicked the naturally occurring developmental process of the male in that all androgenized groups were capable of high levels of male behavior (males but not females showing ejaculation patterns) as well as moderate levels of lordotic receptivity. There were no significant differences in effect among neonatal androgen treatments. The results were discussed as they relate to species differences, sex differences, hamster "bisexuality," and posthormone copulatory performance.

Androstenedione↗
PubMed1975

Immunogenicity of ribosomal vaccines isolated from group A, type 14 Streptococcus pyogenes.

A ribosomal preparation isolated from group A, type 14 Streptococcus pyogenes protected mice against a challenge of 1,000 mean lethal doses. Optimal immunization consisted of subcutaneous administration of 326 mug of protein with Freund incomplete adjuvant. Animals immunized with higher or lower antigen concentrations showed decreased survival. Freund incomplete adjuvant was necessary to insure optimum immunization. Immunochemical studies showed no M protein or C carbohydrate present in the ribosomal preparation. Mice optimally immunized with the type 14 ribosomal preparation were protected against heterologous challenge with M types 2, 5, 8, and 12. Protein-free ribonucleic acid extracts isolated from the type 14 ribosomal preparation did not protect mice against homologous challenge. But ribonucleic acid-free protein extracts showed 100% protection in mice after homologous challenge.

Animals↗
PubMed1975

The selection of a psychiatric curriculum for medical students: results of a survey.

A survey of 131 psychologists, psychiatrists, and nonpsychiatrist physicians taken to determine what doctors of medicine should know about psychiatry revealed that of the 21 topics assessed, there was a significant intergroup agreement on the 10 most important and the 5 least important topics. Interviewing, suicide evaluation, the chronically ill or dying patient, and psychiatric referral received high ratings by each group, and psychoanalytic theory, psychodynamics, and mental retardation received uniformly low ratings. The authors believe that these findings provide useful information for planning an undergraduate curriculum in psychiatry.

California↗
PubMed1975

Non-Hodgkin's lymphoma in children.

The clinical and pathological features of 64 children with non-Hodgkin's malignant lymphoma seen between April 1962 and June 1973 are described. Forty-one children had diffuse, undifferentiated, non-Burkitt lymphoma (lymphoblastic lymphoma). They tended to be boys under 10 years of age and their median survival was 1 year. Almost one-third are surviving for 1-11 years, most in initial complete remission. Nineteen children had diffuse, poorly differentiated, histiocytic lymphoma. They tended to be boys more than 10 years of age, their median survival was only 6 months, and only the 3 patients with Stage I peripheral node tumour survived. Two children had nodular, lymphocytic, poorly differentiated lymphoma and 2 had lymphoma resembling the Burkitt type. From our clinical and pathological observations, we conclude that non-Hodgkin's malignant lymphomata in children cannot be separated from the acute lymphocytic, histiocytic and unclassified leukaemias by cytological or histological methods. What is called diffuse, undifferentiated, non-Burkitt type, or lymphoblastic lymphoma is actually acute lymphocytic leukaemia without apparent invasion of marrow and peripheral blood by neoplastic lymphocytes at time of diagnosis. What is termed diffuse, histiocytic lymphoma is acute histiocytic leukaemia without apparent infiltration of marrow and peripheral blood at initial presentation. One could say just as well that acute lymphocytic leukaemia is Stage IV lymphoblastic lymphoma and that acute histiocytic leukaemia is Stage IV histiocytic lymphoma. Further classification of lymphocytic and histiocytic cancers by newer functional, chemical and morphological methods should include both what is called lymphocytic or histiocytic leukaemia and what is called non-Hodgkin's lymphoma as one group of diseases, susceptible to subclassification by the new methods. We recommend that Stage I lymphocytic and histiocytic cancers be treated with local irradiation. Patients with Stages II-IV tumours should receive anti-leukaemic forms of therapy including prolonged multiple agent chemotherapy and preventive central nervous system irradiation. Staging laparotomy should be considered in patients with Stage I tumour in low cervical, axillary and inguinal nodes.

Adolescent↗
PubMed1975

Fatal "iron heart" in an adolescent: biochemical and ultrastructural aspects of the heart.

Histochemical and ultrastructural aspects of the heart were investigated in an adolescent with fatal congestive heart failure resulting from exogenous hemochromatosis. Extensive iron deposits were found in all four chambers, papillary muscles, and the conduction system. These deposits were most prominent over the outer third of the left ventricular myocardium, with no significant difference between deposits in the middle and inner thirds. Quantitative analysis of iron from different chambers and all zones of the left ventricular myocardium confirmed the aforementioned pattern of iron distribution. Iron deposits in sinoauricular and atrioventricular nodes were similar to those in the right atrial myocardium. Degenerative changes and fibrosis were minimal. Ultrastructural studies showed that intracytoplasmic iron deposition followed a perinuclear, paranuclear, or diffuse pattern. In addition, some iron was consistently present in the nucleus and mitochondria. It is postulated that the presence of iron in the mitochondria may adversely affect the cellular enzyme system; this could provide a biochemical basis for myocardial dysfunction in patients with acquired iron-storage disease.

Adolescent↗
PubMed1975

Antigenic surface determinants of chicken lymphoid cells. II. Selective in vivo and in vitro activity of anti-bursa and anti-thymus sera.

Appropriately absorbed turkey antisera to antigenic surface determinants of chicken bursa (ABS) or thymus cells (ATS) were assessed for their selective immunosuppressive activy in vitro and in vivo. The intraperitoneal injection of ABS or ATS into 2-3-week-old normal white Leghorn chickens entailed a significant depletion of B or T cells respectively from spleen and peripheral blood, while bursa and thymus themselves remained unaffected. The potential of this 'peripheral serological bursectomy and thymectomy' paralleled that found after the conventional surgical procedures with subsequent sublethal irradiation. The mean survival time of skin allografts from donors of genotype B4B4 onto B8B8 recipients was significantly prolonged by treatment with ATS (29 plus or minus 12 days) as compared to untreated (14 plus or minus 2 days), normal turkey serum (12 plus or minus 3 days) or ABS-injected (13 plus or minus 2 days) groups. This selective suppression of a T cell-dependent immune reaction by ATS was also confirmed in vitro by its inhibitory action on the graft-versus-host reactivity of adult peripheral blood lymphocytes in the chorioallantoic membrane assay, where normal turkey serum and ABS were again ineffective. Thus, ABS or ATS produced in avian species may serve not only to delineate B and T cells in vitro, but can also be used for selective manipulation of immune reactions of the chicken in vivo.

Animals↗