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Biomedical subjects

S R Johnson

Publications and source records attributed to S R Johnson.

At least 91 records · Page 5Linked to original sources
PubMed1991

Abortion: is there a rational precept?

Recent Supreme Court rulings have augmented the potential role of the individual states in abortion regulation. As a result, largely political influences have escalated the abortion debate to the point that there is currently no identifiable center, and consensus seems impossible. The traditional concept of viability has proven an inadequate basis for extension of personal rights and protections to the fetus. Conservative interpretation of a proposed neurologic definition of human life would suggest that human life does not start until approximately 70 days post-conception. Standardization and widespread acceptance of a definition of "brain life" would potentially clarify many medical and legal questions regarding elective abortion and would parallel currently accepted medical and legal definitions of death.

Abortion, Legal↗
PubMed1990

Hormonal replacement therapy for postmenopausal women: a review of sexual outcomes and related gynecologic effects.

The impact of hormonal replacement therapy on sexual behavior and functioning in postmenopausal women was examined. A methodological overview discusses issues of subject characteristics, research design, and the assessment of sexual functioning and related outcomes. Current therapy regimens include estrogen, progestogen, androgen, and combination therapy (e.g., cyclic estrogen and progestogen). With estrogen, significant gynecologic improvement (i.e., reduction in atrophic vaginitis) occurs, and this may in turn provide the context for sexual activity/functioning to proceed unimpaired. Although there are medical indications for the addition of progestogen to an estrogen regimen, there appear to be no improvements in sexual functioning beyond those that occur with estrogen alone. Finally, androgen may affect sexual functioning for specific subgroups of postmenopausal women (i.e., surgically postmenopausal rather than naturally postmenopausal women).

Androgens↗
PubMed1989

Three methods for producing fertile hemopoietic chimeras in mice.

Three methods for producing semiallogeneic (F1----parental) hemopoietic chimeras with retained or regained fertility are detailed here. Prenatal (PN) chimeras were produced by injecting F1 ([BALB/c female x C3H/HeJ male] or [CBA/J female x C57BL/6 male]) fetal liver (days 13-18) or adult bone marrow cells (10(6)-10(7) cells/20 microliters/embryo) into the yolk-sac cavities of days 13-17 gestation BALB/c or CBA/J embryos, respectively, and allowing them to be born naturally. Neonatal (NN) chimeras were made by introducing F1 bone marrow cells (1-2 x 10(7) cells/0.25 ml) into newborn (less than 24 hr old) female mice through the anterior facial vein. Female mice were raised to maturity in both cases. Ovary-transplanted (OT) chimeras were made by first irradiating (9.5 Gy) and repopulating young female adult mice with 10(7) F1 bone marrow cells, followed by bilateral orthotopic transplantation of syngeneic ovarian tissue six weeks later. Females reconstituted with the above three methods were mated with normal syngeneic males and sacrificed at 11-16 days of pregnancy to evaluate hemopoietic chimerism. This was determined in all cases by a radioautographic evaluation of the extent of donor H-2 phenotype marker expression on splenic small lymphocytes, after an indirect labelling of single-cell suspensions with monospecific antibody and [125I]protein-A. Results indicate that hemopoietic chimerism was best in the PN group (0.3-78.1%, mean = 27.1); intermediate in the OT group (5.8-38.2%, mean = 18.1); and low in the NN group (0-14%, with one exception, which was 83.6%). Observed fertility was best for BALB/c host PN chimeras.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Hemopoietic origin of certain decidual cell precursors in murine pregnancy.

The possible hemopoietic origin of certain precursors of uterine decidual cells appearing during normal murine pregnancy was investigated in semiallogeneic hemopoietic chimeras with retained or regained fertility. Chimeras were produced by three different methods in two donor-host combinations: F1 [BALB/c female x C3H/HeJ male] cells introduced into the parental strain BALB/c female hosts or F1 [CBA/J female x C57BL/6 male] cells introduced into CBA/J female hosts. Prenatal chimeras (PN) were made by reconstituting mouse fetuses (day 13-17) with 10(6)-10(7) adult bone marrow or fetal liver cells through the yolk sac and they were allowed to be delivered naturally. Neonatal chimeras (NN) were made by injecting 1-2 x 10(7) adult bone marrow cells into the anterior facial vein of neonatal mice (less than 24 hr old). In both cases, experimental animals were raised to maturity. Ovary-transplanted chimeras (OT) were made by injecting 10(7) bone marrow cells into lethally irradiated (9.5 Gy) young adult female mice, followed 6 weeks later with bilateral orthotopic transplants of syngeneic ovary grafts to restore fertility. All female chimeras produced by the three different methods were mated with syngeneic male partners to produce normal pregnancy. The extent of chimerism at the cellular level was determined in all cases by a radioautographic identification of the H-2 phenotype of splenic lymphocytes and decidual cells and macrophages in the collagenase-dispersed decidua at day 11-16 of normal pregnancy, following a sandwich labelling with monospecific anti-H-2 antibodies and 125I-protein A. Morphological discrimination of typical decidual cells from macrophages in the collagenase-dispersed decidua was carried out on the basis of several distinctive markers: presence of surface Dec-1 and Thy-1 and absence of surface F4/80 or latex phagocytosis for decidual cells, in contrast to macrophages which were phagocytic and expressed F4/80 but not Dec-1 or Thy-1. While the degree of hemopoietic chimerism (judged by the incidence of donor-derived lymphocytes in the spleen) varied from animal to animal, in all three groups (PN, NN, and OT) comprising a total of 26 chimeras, the percentage of typical decidual cells expressing donor H-2 phenotype showed an excellent correlation with that for small lymphocytes in the spleen. These results reveal that at least a subpopulation of typical decidual cells of the pregnant uterus has a hemopoietic genealogy. A possible familial relationship of these cells to granulated metrial gland cells remains unclear.

Animals↗
PubMed1988

Ski injuries, the significance of flake fractures.

All patients returning from skiing holidays who had sustained injuries of the knee ligaments were assessed. Thirteen patients had radiologically evident flake fractures around the knee. Of these, all had marked laxity when examined under anaesthetic. In ten cases the accident had occurred at low speed. It is concluded that all knee injuries following a skiing fall must be examined to exclude ligament laxity. The relevance of the bony flakes is discussed.

Athletic Injuries↗
PubMed1988

Silastic foam in injured patients.

Four dressing techniques are described; these techniques enable patients with granulating wounds complicating skeletal injuries to be treated as outpatients. The patients perform their own dressings, thus reducing demands on nursing services and freeing hospital beds. In a study of 63 patients there was no problem in managing the wounds from weekly outpatient clinics; good wound healing was achieved.

Bandages↗
PubMed1988

Epidemiology of premenstrual symptoms in a nonclinical sample. I. Prevalence, natural history and help-seeking behavior.

A stratified sample of 996 nursing school graduates from 1963 to 1984 was surveyed by mail regarding menstrual cycle characteristics. The 730 respondents reported an 87% overall lifetime prevalence of premenstrual symptoms. When the symptoms were categorized according to severity, only 3.2% of the respondents reported severe symptoms. Symptomatic women used diet change (24.6%), exercise (41.8%) and vitamins (18.9%) as self-help measures. Seventeen percent sought advice from a physician. Drug use was common; 22% were using a drug for symptoms at the time of the survey. Despite the common use of treatment, few women reported a significant work impairment. These findings support the conclusion that premenstrual symptoms are common but do not usually interfere with functioning.

Adult↗
PubMed1988

An empirical specification of residency performance dimensions.

A critical aspect of any residency is the process of selection and evaluation. However, the research literature has failed to provide an adequate behavioral specification of performance components to assist in selection and evaluation decisions. In this investigation, we applied a widely accepted method of job analysis from personnel psychology, the critical incident technique, to define those behaviors and attitudes necessary for successful resident performance in obstetrics and gynecology. Nine mutually exclusive categories of behavior were identified, including conscientiousness, recognition of limits, confidence in skills and training, ability to handle crisis/emergency situations, integration of knowledge with practice, technical skills, relationships with staff, relationships with patients, and ethical actions. These categories appear to be reliable, as physician raters were able to sort incidents into appropriate categories with 94% reliability. Identification of these categories represents a beginning step toward determining necessary aspects of performance in a structured and replicable manner and toward defining these performance aspects in a manner that allows precise and reliable measurement.

Behavior↗
PubMed1987

Variability of food intakes. An analysis of a 12-day data series using persistence measures.

Data from the US Department of Agriculture's Exploratory Study of Longitudinal Measures of Individual Food Intake, conducted in 1982, were used to evaluate individual intakes for day-to-day patterns and to relate these patterns to the reliability of estimated daily energy and nutrient intake means. Generalized least squares estimators incorporating a simple persistence hypothesis showed the importance of including day-to-day patterns in estimating mean daily intake levels. The simple persistence hypothesis was that day-to-day intakes follow a first-order autoregressive process. Results on the accuracy of mean intake estimates and sample size suggested that for the dietary components examined, greatest gains in accuracy of estimated mean daily intake were generally obtained with the first six days of intake data. This conclusion was, however, highly conditioned by the inclusion of the persistence hypothesis in the calculations. It was concluded that additional investigations exploring alternative and perhaps more physiologically justified persistence hypotheses for food intakes would improve the use of sample data in estimating mean daily intakes of diet components.

Adult↗