PubMed Health⌕ Search

Biomedical subjects

R S Howe

Publications and source records attributed to R S Howe.

15 recordsLinked to original sources
PubMed1995

Fixed patterns of bradycardia during late embryonic development in domestic fowl with C locus mutations.

A predictable late embryonic bradycardia (relative to normal White Leghorn chickens) has been documented in chicken strains with C locus mutations. The basis of the bradycardia remains unknown but clearly is related to a mutation at the C locus, which contains the structural gene for tyrosinase. When compared with the heart rate of normal White Leghorns (approximately 295-305 beats/min from day 8 to day 20 of incubation), ca/ca and other C locus mutants showed a 10-12% reduction in heart rate during the last 4 days of incubation. Embryonic mortality occurred in both mutant and normal strains at an equivalent rate (approximately 23%); a significant bradycardia (when compared with surviving embryos of the same strain) developed on the day before death in White Leghorn but not mutant strains. The bradycardia did not affect embryonic oxygen consumption (approximately 0.2 ml O2.egg-1.min-1 at day 14 and 0.4 ml O2.egg-1.min-1 at day 20), which showed only minor differences between strains that can be attributed to differences in embryonic mass on days 16-20.

Animals↗
PubMed1994

Use of flutamide for self-induced androgen excess. A case report.

A 28-year-old woman developed hirsutism, facial edema and clitoromegaly after self-injection of long-acting synthetic androgens. The symptoms were ameliorated by administration of flutamide with a combination oral contraceptive. Flutamide appears to be useful in preventing sequelae of acute androgen excess in women and may be a rational therapy for chronic treatment of androgen excess in women.

Adult↗
PubMed1993

Third-trimester uterine rupture following hysteroscopic uterine perforation.

BACKGROUND: As operative hysteroscopy becomes more common, long-term complications become apparent. CASE: A 29-year-old woman had a hysteroscopic uterine septum resection. This was complicated by a small fundal puncture. In the ensuing pregnancy, uterine rupture occurred at 33 weeks and resulted in neonatal mortality and maternal morbidity. CONCLUSION: Uterine rupture may follow uterine perforation at operative hysteroscopy; patients contemplating pregnancy after such perforation warrant appropriate counseling.

Adult↗
PubMed1991

Embryonic heart rate in human pregnancy.

Seventy-two women with known gestational ages underwent serial human chorionic gonadotropin (hCG) measurements and transvaginal ultrasound studies with embryonic heart rate measurements. In 53 continuing singleton pregnancies, embryonic pulse appeared between days 26 and 32, was 80 beat per minute (bpm) on day 26, and increased linearly to plateau at 160-200 bpm by day 45 (r2 = 0.72). The pulse was always seen with hCG greater than 21,000 mIU/mL; pulse rate was correlated to embryonic crown-rump length. Of the remaining 19 pregnancies, 8 were anembryonic, 10 showed heart activity but subsequently aborted, and 1 was terminated. Absence of embryonic pulse by 32 days after conception or a serum hCG greater than 21,000 mIU/mL predicts spontaneous abortion; presence of a pulse may not guarantee successful continuation of the pregnancy since incidence of spontaneous abortion after visualization of embryonic pulse may be as high as 16%.

Abortion, Spontaneous↗
PubMed1990

Glucocorticoid and progestin regulation of eosinophil chemotactic factor and complement C3 in the estrogen-treated rat uterus.

To study the steroid regulation of estradiol-induced uterine eosinophil chemotactic factor activity (ECF-U) in the rat, we injected immature female rats with combinations of estradiol, dexamethasone, progesterone, and the antihormones RU-486 and ketoconazole. An in vitro chemotactic system using blind well chambers and employing eosinophil-differentiated HL-60 promyelocytic cells was used as a bioassay for ECF-U activity. Dexamethasone and progesterone both antagonized the effects of estradiol on stimulation of ECF-U activity; neither hormone induced ECF-U activity when given alone. RU-486 and ketoconazole were able to block the inhibitory effects of dexamethasone and progesterone. The effects of dexamethasone and progesterone appear to be mediated through their specific nuclear receptors and are not due to direct effects on the chemotactic cell. Comparison of the steroid regulation of ECF-U activity with the estradiol-induced synthesis and secretion of complement component C3 showed that progesterone antagonized the effects of estradiol in both systems, whereas dexamethasone was antagonistic on ECF-U, but not on the secretion of C3. Taken together these results suggest that estradiol's effects in the rat uterus may be modulated by other steroids in at least two systems, bringing into question the common practice of studying uterine steroid actions by evaluation of a single protein or mRNA.

Animals↗
PubMed1990

Perinatal outcome of singleton pregnancies conceived by in vitro fertilization: a controlled study.

To determine whether conception by in vitro fertilization and embryo transfer (IVF) predisposes to perinatal complications, the obstetric records of 54 women delivered of singleton pregnancies after conception by IVF were examined. Control women were matched for age, parity, race, year of delivery, diethylstilbestrol exposure and medical problems; another group of women who conceived after infertility treatment was matched in similar fashion. IVF patients showed a longer first stage of labor than previously infertile women, experienced a greater intrapartum blood loss than control or previously infertile women, and showed a trend toward a higher cesarean delivery rate than control women. The differences noted probably do not arise from the physiology of IVF, and although some differences are statistically significant, they are of minimal clinical significance. Singleton pregnancies arising after IVF should not be considered as high risk in the absence of other predisposing factors.

Adult↗
PubMed1990

Chemotactic capabilities of HL-60 human myeloid leukemia cells differentiated to eosinophils.

HL-60 human myeloid leukemia cells can be induced to differentiate into cells with many of the morphological, biochemical, and functional features of mature neutrophils, monocyte/macrophages, and eosinophils. HL-60 neutrophils are known to respond to several chemotactic compounds, but similar data do not exist for HL-60 eosinophils. We studied the chemotactic capabilities of eosinophil-differentiated HL-60 cells using a blind-well chamber technique. HL-60 eosinophils responded to the specific eosinophilotactic tetrapeptides Ala-Gly-Ser-Glu, Val-Gly-Asp-Glu, and Val-Gly-Ser-Glu; to the formylated tripeptide N-formyl-L-Met-L-Leu-L-Phe (fMLP); and to extracts estrogen-treated rat uteri, which contain an eosinophilotactin. Concentration optima for chemotaxis of HL-60 eosinophils were similar to those for normal human and rodent eosinophils. Neutrophil-differentiated HL-60 cells responded only to fMLP, whereas undifferentiated HL-60s showed no chemotactic ability. The time course of development of chemotactic competence paralleled other developmental changes in HL-60 eosinophilic differentiation, suggesting a common control mechanism. We conclude that the ability to respond to specific eosinophilotactic compounds is a feature of HL-60 cells that have differentiated to eosinophils and that this cell line may be used as a model system in studies of eosinophil chemotaxis.

Cell Differentiation↗
PubMed1989

Estrogen regulation of an eosinophil chemotactic factor in the immature rat uterus.

Associated with the generalized uterine growth stimulated by estradiol in the rat are specific responses including messenger RNA (mRNA) synthesis, protein synthesis, and peroxidase activity. The increase in peroxidase activity, although sensitive to inhibitors of RNA and protein synthesis, results from an estradiol-stimulated influx of eosinophils into the uterus. We postulated the existence of an estradiol-regulated uterine chemotactic factor, testing this by an in vitro chemotactic assay with eosinophils isolated from mature rats. Treatment of immature rats with 1 microgram estradiol for 24 h resulted in a significant increase in eosinophil chemotaxis compared to uterine extracts of vehicle-treated rats. This increase was seen as early as 3 h after estradiol administration and was maximal at 24 h. The magnitude of the chemotactic response was dependent on the dose of estradiol administered (1-100 micrograms). Estrone or estriol treatment resulted in chemotactic activity greater than control but less than estradiol. Direct addition of estradiol to extracts of control animals did not increase chemotaxis. The estradiol-stimulated chemotaxis was blocked by in vivo treatment with the antiestrogen tamoxifen and by inhibitors of RNA and protein synthesis. Analysis of extracts from estradiol-treated uteri shows that the chemotactic factor is heat labile, pronase sensitive, and has a mass of approximately 20 kilodaltons (kDa). These data suggest that the estradiol-stimulated influx of eosinophils into the rat uterus is mediated by the synthesis, modification, or release of a protein whose synthesis is estradiol receptor mediated.

Animals↗
PubMedDate not supplied

Case management in managed care: past, present, and future.

Case management (CM) has undergone radical, rapid change during the past 20 years and, from all appearances, shows no signs of slowing down. This article attempts to lay out the factors that will lead to the future of CM from three perspectives: patients, providers, and payers--the trilogy of the health care industry. The content of this article is rather provocative, intentionally designed to kindle thought and generate alternative ways to approach CM programs.

Case Management↗
PubMedDate not supplied

Outpatient initiation of insulin: a nurse practitioner protocol.

Noninsulin dependent diabetes (type II diabetes) is a chronic disease characterized by hyperglycemia. Clients can generally be controlled by diet and exercise or a combination of diet, exercise, and oral hypoglycemic agents. When this therapy is not effective in controlling the hyperglycemia, the health care provider must choose to initiate insulin therapy. Outpatient initiation of insulin is an alternative to hospitalization in the type II diabetic client. Clinical guidelines for the initiation of insulin on an outpatient basis and management of the diabetic client are presented.

Ambulatory Care↗