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Biomedical subjects

C A Walters

Publications and source records attributed to C A Walters.

17 recordsLinked to original sources
PubMed2001

Error patterns of 3rd-year medical students on the cardiovascular physical examination.

BACKGROUND: Recent research documents widespread deficits in the physical examination skills of practicing physicians. PURPOSE: This study explored physical examination skills of 3rd-year medical students after completion of a course in physical diagnosis. METHODS: Standardized patient physical examination checklist data were analyzed for a cohort of 2,038 medical students for a patient presenting with classic signs and symptoms of an acute myocardial infarction. A follow-up paper case and survey explored reasons underlying omissions. RESULTS: Students systematically omitted 3 of 10 component maneuvers critical to the evaluation of a patient with shortness of breath and chest pain. The same pattern of omissions was observed across 8 medical schools and over 2 successive years. The paper case follow-up study ruled out time constraints and performance anxiety as the cause. Survey data revealed that students may omit a maneuver due to inability to recall pertinence (blood pressure in both arms) or difficulty discriminating findings (heart sounds at different locations), or because of inadequate technical mastery (percussion of the lungs). CONCLUSIONS: These data suggest fundamental inadequacies in the current paradigm for teaching physical examination skills. Standardized patient checklist data can provide an informative window into the efficacy of teaching practices.

Clinical Competence↗
PubMed1996

A comparison of time, temperature, and refreezing variables on frozen sperm motility recovery.

OBJECTIVE: To compare motility recovery among methods of thawing semen in serial freeze-thaw processes. DESIGN: A comparison of treatments. SETTING: Semen cryobank laboratory. PARTICIPANTS: Semen samples from an existing cryobank. INTERVENTIONS: Portions of each of 35 ejaculates were thawed serially in either a 37 degrees C water bath for 10 minutes or at room temperature for 30 minutes. Motility was estimated, and the samples were immediately refrozen. Thaws were performed initially (T1), at 24 hours (T2), and at 1 week (T3). MAIN OUTCOME MEASURE: Percent motility. RESULTS: The initial motility of all samples averaged 73.2%. Serial thaws at 37 degrees C yielded mean motility recoveries of 34.0%, 21.8%, and 8.3% for T1, T2, and T3, respectively. Those at room temperature were 22.4%, 7.9%, and 1.3%. Motilities progressively decreased from initial to final thaw regardless of temperature. Semen thawed at 37 degrees C had a higher motility recovery at all thaw times compared with samples thawed at room temperature. CONCLUSIONS: For sperm frozen rapidly in liquid nitrogen and for sperm subjected to multiple freeze-thaw processes, motility recovery is improved if thaw is carried out at 37 degrees C versus room temperature.

Cryopreservation↗
PubMed1987

Luteal phase defect and premenstrual syndrome in an infertile population.

To test the hypothesis that an abnormal luteal phase is associated with significant symptoms of premenstrual syndrome, psychologic and somatic premenstrual syndrome symptoms were evaluated in a group of 83 infertile patients undergoing timed endometrial biopsy for the assessment of luteal phase adequacy. The severity of psychologic and somatic symptoms was evaluated separately. It was found that luteal phase defect, defined by endometrial biopsy, was associated with less severe psychologic and no more severe somatic symptoms of premenstrual syndrome in comparison with normal luteal phase controls. The data suggest that the hormonal milieu associated with luteal phase defects does not correlate with premenstrual syndrome symptoms and do not support the hypothesis that suboptimal ovarian function causes premenstrual syndrome.

Adult↗
PubMed1985

Prolactin production by explants of normal, luteal phase defective, and corrected luteal phase defective late secretory endometrium.

The production of prolactin by explants of late secretory endometrium has been correlated with the extent of decidual differentiation. This correlation is strengthened by the observation that luteal phase defective endometrium produces less prolactin than normal control endometrium in a 24-hour in vitro culture system. In the present study the prolactin production by explants of normal, luteal phase defective, progesterone-corrected luteal phase defective, and clomiphene- or follicle-stimulating hormone/luteinizing hormone-corrected luteal phase defective late secretory endometrium was measured over 96 hours at 24-hour intervals. Progesterone in physiologic concentrations was added to the culture medium to maintain tissue integrity and prolactin synthesis. The prolactin production of normal late secretory endometrium rose over 96 hours under progesterone stimulation. The luteal phase defective endometrium produced significantly less prolactin under the same conditions. Histologically proven corrected luteal phase defective endometrium, regardless of treatment method, produced prolactin not different from the normal controls of the same dates. From these results it is concluded that histologic correction of luteal phase defective endometrium is associated with a corresponding biochemical correction with use of prolactin as a metabolic marker. The findings also strongly support timed endometrial biopsy as the method of diagnosis and evaluation of treatment of luteal phase defect.

Biopsy↗
PubMed1985

Titrating the dose of bromocriptine when treating hyperprolactinemic infertile women.

We have shown that a smaller dose of bromocriptine is effective in lowering the PRL level to the normal range in some hyperprolactinemic women. Based on these findings, we recommend that when treating hyperprolactinemic women who desire conception, the dose of bromocriptine should be titrated according to the response of circulating PRL levels. This will minimize the dose, reduce cost, probably reduce side effects, and possibly avoid undesirable functional effects such as corpus luteum dysfunction.

Bromocriptine↗
PubMed1984

Prolactin production from proliferative phase leiomyoma.

In vivo and in vitro endometrial stromal synthesis of prolactin occurs after progesterone-induced decidualization. Synthesis of prolactin by myometrium in vitro suggests that cells whose embryologic origin is the loose mesenchyme surrounding the paramesonephric ducts may retain the capacity to synthesize prolactin. Since physiologic myometrial synthesis of prolactin has not been demonstrated in vivo, prolactin genome expression in pathologic conditions was considered. Follicular phase leiomyomas were diced to 8 mm3 and cultured in Dulbecco's modified Eagle's medium (DMEM) with either no hormones, estradiol 200 pg/ml, progesterone 20 ng/ml, or estradiol and progesterone. Media were sampled and changed every other day for 8 days, followed by culture in tritium-labeled leucine DMEM for 2 days. Portions of leiomyomas were homogenized for initial prolactin content, and all samples were assayed for prolactin by radioimmunoassay. Follicular phase leiomyomas contained prolactin (47 +/- 15 ng/gm) in excess of normal serum values. Synthesis was demonstrated during all time periods from leiomyomas not exposed to progesterone. Progesterone variably suppressed the synthesis of prolactin until after 144 hours of culture. Determination of molecular weight on a 60 by 1.5 cm Sephadex G-100 column revealed identical estimates for pituitary, decidual, and leiomyoma prolactin. Tritium-labeled leucine incorporation into prolactin was confirmed by immunoprecipitation of Sephadex G-100 column fractions. Similar antigenicity was confirmed by parallel dilution curves for pituitary, decidual, and leiomyoma prolactin. Preliminary bioactivity in lymphoma proliferation assays confirmed prolactin activity. The conclusion reached was that proliferative phase leiomyomas contained elevated prolactin presumably secondary to in vivo synthesis. This synthesis was confirmed in vitro.

Culture Techniques↗
PubMed1984

A randomized study of dexamethasone in ovulation induction with clomiphene citrate.

Improved understanding of follicular dynamics has led to a reevaluation of suppression of adrenal androgens in ovulation induction. To test whether adrenal suppression during clomiphene citrate (CC) therapy would improve ovulation/pregnancy rates, 64 anovulatory patients who had not previously received CC were randomly assigned to receive either 50 mg CC on days 5 to 9 alone or with 0.5 mg dexamethasone (CC + DEX). Patients were then screened for dehydroepiandrosterone sulfate (DHEA-S) (normal range, 80 to 320 micrograms/dl), prolactin, testosterone, and semen analysis of the partner. Nine patients discontinued participation prior to completing the first treatment cycle, and ten patients were found to have either elevated prolactin (4), severe male factors (3), or tubal disease (3) and were discontinued. CC was increased 50 mg/day per cycle through 150 mg/day until ovulation occurred. Once the patient was ovulatory on therapy, a properly timed postcoital test and endometrial biopsy for luteal phase defect were performed. If anovulatory at 150 mg/day of CC or demonstrating abnormal postcoital test or endometrial biopsy at 150 mg/day of CC, patients were crossed to the other arm of the treatment protocol. The results revealed a significantly higher rate of ovulation (P less than 0.01) and conception (P less than 0.05) in the CC + DEX-treated group. When correlated with DHEA-S levels, this improvement occurred in patients with DHEA-S greater than 200 micrograms/dl (P less than 0.05).

Adrenal Glands↗
PubMed1983

Human myometrium: a new potential source of prolactin.

Human myometrium is shown for the first time to produce prolactin in vitro. This prolactin is similar to pituitary prolactin by criteria of immunologic identity, gel chromatography and bioassay. The de novo synthesis of myometrical prolactin is supported by no detectable prolactin in initial tissue homogenate, nondetectable prolactin production during the first 24 hours of culture, cycloheximide inhibition of prolactin production with recovery of production in control medium, and tritiated leucine incorporation into prolactin. Although human myometrium is capable of producing prolactin without the addition of exogenous hormones, the addition of estrogen and progesterone, respectively, enhances and suppresses prolactin production in contrast to decidualized human endometrium where opposite effects on prolactin production are found.

Culture Techniques↗
PubMed1983

Hysteroscopic metroplasty: surgical technique and obstetric outcome.

Congenital Müllerian abnormalities, particularly the septate uterus, may result in recurrent abortion or premature labor. Twenty-five patients found to have a septate uterus during evaluation for infertility or recurrent abortion were treated by hysteroscopic metroplasty with laparoscopic visualization. Surgical outcome was excellent, intraoperative and postoperative morbidity was negligible, and the postoperative course was similar to that following laparoscopy alone. Preoperative fetal wastage in 17 previously fertile patients was 90%. Of 11 patients, 6 or more months postoperatively, 10 had conceived: 5 delivered vaginally at term, 2 delivered by cesarean section, and 2 pregnancies are in progress. One pregnancy miscarried at 21 weeks secondary to an incompetent cervix. With hysteroscopic metroplasty, septa can be incised successfully with lower morbidity and as good a surgical outcome as with abdominal procedures. If further studies confirm the pregnancy outcome reported, then hysteroscopic metroplasty should become the treatment of choice for the septate uterus.

Abortion, Habitual↗
PubMed1983

Endometrial biopsy during treatment of luteal phase defects is predictive of therapeutic outcome.

Luteal phase deficiency (LPD), as diagnosed by endometrial biopsy, is not a single disorder but rather a spectrum of dysfunction that reflects both endometrial cycle and ovarian cycle abnormalities. Forty-three patients were diagnosed as having LPD by two consecutive abnormal cycles. Seven patients (16%) with hyperprolactinemia received bromocriptine, and one hypothyroid patient received thyroid replacement. The remaining patients were treated sequentially with progesterone suppositories, clomiphene, the combination, and follicle-stimulating hormone and luteinizing hormone. If no conception occurred in 6 months on a given type of therapy, treatment was advanced. Patients were rebiopsied on each medication. In all, 33 of 41 (81%) compliant patients conceived. No viable pregnancies occurred without normal endometrial maturation, regardless of the treatment modality employed. When compared with time-life table projections, pregnancies occurred at rates comparable to those of a normal population once normal endometrial maturation was obtained with therapy. The endometrial biopsy accurately reflects the functional state of both the ovarian cycle and the endometrial cycle and can be used to determine adequacy of therapy, thereby improving conception rates in patients with LPD and eliminating the need for therapeutic trials.

Adult↗
PubMed1983

The uterus as an endocrine compartment.

Evidence has begun to accumulate over the past several years that the uterus is a much more complex organ than was previously thought. Data would suggest that the uterus is a tissue that actively secretes a variety of substances that act locally and at distant sites from the uterus in the control of normal nonconceptual physiologic events, in gestation, and in influencing pathophysiologic symptoms. This article discusses the data underlying the concept of the uterus as an endocrine compartment with particular emphasis on the physiology of the decidualized endometrial stroma.

Decidua↗
PubMedDate not supplied

The neglected laboratory test. The semen analysis.

Sixty-four laboratories from Connecticut, Massachusetts, and California were involved in a comparison of the types of semen analyses offered. The collected data indicate that there is a wide range of normal values for each parameter considered in a semen analysis. Very few laboratories gave simple and precise instructions for collection of the specimen. In many instances there was no record of the collection time or of the arrival time of the specimen at the laboratory. Most laboratories did not report motility or forward progression at time intervals, and abnormal morphology was not broken down according to the types of abnormalities involved. These data indicate the absolute need for adequate standardization of this important test, which is the basis upon which the clinician makes the important decision of implicating the male partner in the couple's infertility problem.

California↗