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Biomedical subjects

H E Fox

Publications and source records attributed to H E Fox.

At least 19 recordsLinked to original sources
PubMed2006

Variation in caregiver perceptions of teamwork climate in labor and delivery units.

OBJECTIVE: To test the psychometric soundness of a teamwork climate survey in labor and delivery, examine differences in perceptions of teamwork, and provide benchmarking data. DESIGN: Cross-sectional survey of labor and delivery caregivers in 44 hospitals in diverse regions of the US, using the Safety Attitudes Questionnaire teamwork climate scale. RESULTS: The response rate was 72% (3382 of 4700). The teamwork climate scale had good internal reliability (overall alpha = 0.78). Teamwork climate scale factor structure was confirmed using multilevel confirmatory factor analyses (CFI = 0.95, TLI = 0.92, RMSEA = 0.12, SRMR(within) = 0.04, SRMR(between) = 0.09). Aggregation of individual-level responses to the L&D unit-level was supported by ICC (1) = 0.06 (P < 0.001), ICC (2) = 0.83 and mean r (wg(j)) = 0.83. ANOVA demonstrated differences between caregivers F (7, 3013) = 10.30, P < 0.001 and labor and delivery units, F (43, 1022) = 3.49, P < 0.001. Convergent validity of the scale scores was measured by correlations with external teamwork-related items: collaborative decision making (r = 0.780, P < 0.001), use of briefings (r = 0.496, P < 0.001) and perceived adequacy of staffing levels (r = 0.593, P < 0.001). CONCLUSION: We demonstrate a psychometrically sound teamwork climate scale, correlate it to external teamwork-related items, and provide labor and delivery teamwork benchmarks. Further teamwork climate research should explore the links to clinical and operational outcomes.

Adult↗
PubMed2000

Effect of student ethnicity on interpersonal skills and objective standardized clinical examination scores.

OBJECTIVE: To determine whether standardized patients' perceptions of medical students' ethnicity influenced ratings on the interpersonal skills subsection of the objective standardized clinical examination (OSCE) and performance overall on the OSCE. METHODS: The OSCE is used to evaluate medical students' performances in the obstetrics and gynecology basic clerkship at the Johns Hopkins University School of Medicine. It is based on a series of standardized patient interviews conducted by medical students and incorporates ratings by standardized patients on each student's interpersonal skills. Medical students (n = 353) enrolled in the obstetrics and gynecology basic clerkship from 1995-1998 were classified according to ethnicity. Overall OSCE scores according to ethnicity were analyzed using one-way analysis of variance. Total interpersonal skills scores and scores on the individual components of the interpersonal skills section of the OSCE were analyzed according to students' ethnicity using the Kruskal-Wallis test for nonparametric analysis of variance. RESULTS: There were no statistically significant differences among ethnic groups in overall OSCE scores, total interpersonal skills scores, or scores on the individual components of the interpersonal skills section of the OSCE. CONCLUSION: No bias attributable to perceived medical student ethnicity that affects performance on the OSCE exists.

Baltimore↗
PubMed1997

Stress and dominance in a social fish.

Many aspects of reproductive physiology are subject to regulation by social interactions. These include changes in neural and physiological substrates of reproduction. How can social behavior produce such changes? In experiments reported here, we manipulated the social settings of teleost fish and measured the effect (1) on stress response as reflected in cortisol production, (2) on reproductive potential as measured in production of the signaling peptide, gonadotropin-releasing hormone, and (3) on reproductive function measured in gonad size. Our results reveal that the level of the stress hormone cortisol depends critically on both the social and reproductive status of an individual fish and on the stability of its social situation. Moreover, the reproductive capacity of an individual fish depends on these same variables. These results show that social encounters within particular social contexts have a profound effect on the stress levels as well as on reproductive competence. Social behavior may lead to changes in reproductive state through integration of cortisol changes in time. Thus, information available from the stress pathway may provide socially relevant signals to produce neural change.

Animals↗
PubMed1997

Patterns of fetal perinasal fluid flow in cases of congenital diaphragmatic hernia.

OBJECTIVE(S): Our purpose was to expand the previous reported series of observations of fetal perinasal fluid flow in cases of antenatally diagnosed congenital diaphragmatic hernia, characterize the timing parameters of the fetal breath cycle, and define the relationship of fetal perinasal fluid flow and the diaphragmatic component of fetal breathing movements. Our hypothesis was that characteristics of diaphragm-related and nondiaphragm-related perinasal fluid flow and other breath cycle characteristics differ in cases of congenital diaphragmatic hernia compared with controls. STUDY DESIGN: Fetal perinasal fluid flow velocity and fetal chest wall movements were studied in 24 cases of uncomplicated pregnancy, and flow was studied in 24 cases of antenatally diagnosed congenital diaphragmatic hernia at gestational ages ranging from 30 to 41 weeks. The examination of fetal perinasal fluid flow velocity was performed with use of an ultrasonography system applying color flow and spectral Doppler analysis. Breath-to-breath interval, time of inspiration, time of expiration, and peak inspiratory and expiratory velocities were determined for each type of perinasal flow. RESULTS: The study revealed that the time of expiration in cases of congenital diaphragmatic hernia at 30 to 36 and 37 to 41 weeks of gestation was significantly shorter than in cases of uncomplicated pregnancy. The ratio of time of inspiration and breath-to-breath interval in cases of diaphragmatic hernia was approximately 30% higher (p = 0.001) at 30 to 36 weeks of gestation than in cases of uncomplicated pregnancy. The study also showed that in cases of congenital diaphragmatic hernia the expiratory peak velocity ratio at 30 to 36 weeks of gestation was significantly lower than in cases of uncomplicated pregnancy. CONCLUSIONS: We conclude that by Doppler ultrasonography measurements of fetal perinasal fluid flow, in cases of congenital diaphragmatic hernia, we can evaluate the timing parameters of fetal diaphragm-related breath cycles, the relationship of intraalveolar and intraamniotic pressures, and fetal upper respiratory tract resistance. Fetuses with diaphragmatic hernia spent significantly more time with diaphragm-nonrelated perinasal flow than did fetuses in cases of uncomplicated pregnancy, which can cause the increased loss of lung liquid and consequently be associated with pulmonary insufficiency in the early neonatal period.

Body Fluids↗
PubMed1996

Obstetrical factors and the transmission of human immunodeficiency virus type 1 from mother to child. The Women and Infants Transmission Study.

BACKGROUND: A substantial proportion of perinatally acquired infections with the human immunodeficiency virus type 1 (HIV-1) occur at or near delivery, which suggests that obstetrical factors may have an important influence on transmission. We evaluated the relation of such factors and other variables to the perinatal transmission of HIV-1. METHODS: The Women and Infants Transmission Study is a prospective, observational study of HIV-1-infected women who were enrolled during pregnancy and followed with their infants for three years after delivery. We studied obstetrical, clinical, immunologic, and virologic data on 525 women who delivered live singleton infants whose HIV-1-infection status was known as of August 31, 1994. RESULTS: Among mothers with membranes that ruptured more than four hours before delivery, the rate of transmission of HIV-1 to the infants was 25 percent, as compared with 14 percent among mothers with membranes that ruptured four hours or less before delivery. In a multivariate analysis, the presence of ruptured membranes for more than four hours nearly doubled the risk of transmission (odds ratio, 1.82; 95 percent confidence interval, 1.10 to 3.00; P = 0.02), regardless of the mode of delivery. The other maternal factors independently associated with transmission were illicit-drug use during pregnancy (odds ratio, 1.90; 95 percent confidence interval, 1.14 to 3.16; P = 0.01), low antenatal CD4+ lymphocyte count (<29 percent of total lymphocytes) (odds ratio, 2.82; 1.67 to 4.76; P<0.001), and birth weight <2500 g (odds ratio, 1.86; 1.03 to 3.34; P = 0.04). CONCLUSIONS: The risk of transmission of HIV-1 from mother to infant increases when the fetal membranes rupture more than four hours before delivery.

Adult↗
PubMed1996

Patterns of perinasal fluid flow and contractions of the diaphragm in the human fetus.

Our aim was to identify patterns of fetal perinasal fluid flow, and to determine the relationship of pattern of flow to the diaphragmatic component of fetal breathing movements. Twenty-four fetuses were studied with the use of two ultrasound systems simultaneously. Continuous video-tape records of the color and spectral Doppler imaging of fluid flow velocity in the nose and of the movements of the fetal diaphragm were made on two video recorders during 30-min study sessions. Two different patterns of fetal perinasal flow were recognized. One type had a rapid rate and low amplitude, and was independent of ultrasonographically observed movements of the fetal diaphragm. The other type had a lower rate and higher amplitude, and was uniformly related to diaphragmatic contractions. The breath-to-breath interval, time of inspiration, time of expiration and peak inspiratory and expiratory velocities were determined for each type of perinasal flow. Two ratios were used to quantify the change of peak flow velocity. There were significant differences in the values of all timing parameters between diaphragm-related perinasal flow velocities and those not related to the diaphragm, at both 30-36 and 37-41 weeks of gestation. The rate of perinasal flow related to diaphragmatic contraction cycles was one-third that of the flow cycles not related to diaphragmatic contraction (approximately 50 vs. 148 cycles/min). For both patterns of perinasal flow velocity, the expiratory peak velocity ratio was about 1.6 times higher than the inspiratory peak velocity ratio. We conclude that, in uncomplicated pregnancy, one pattern of fetal perinasal fluid flow reflects activity of the diaphragm. We speculate that the contractions of the fetal airway smooth muscle or oropharyngeal-laryngeal muscle groups are the origin of the second pattern of perinasal flow.

Blood Flow Velocity↗
PubMed1996

Association of maternal drug use during pregnancy with maternal HIV culture positivity and perinatal HIV transmission.

OBJECTIVE: To evaluate the relationship of drug use with maternal HIV culture positivity at delivery and perinatal HIV transmission. DESIGN: Multicenter prospective cohort study. SETTING: Obstetric and pediatric clinics in five cities in the United States. PARTICIPANTS: Five hundred and thirty HIV-infected pregnant women and their infants. MAIN OUTCOME MEASURES: Multivariate logistic regression was used to evaluate the association of 'hard drug' use (one or more of the following: cocaine, heroin/opiates, methadone, injecting drug use) assessed by self-report and urine toxicology with positive maternal HIV culture at delivery and perinatal HIV transmission. RESULTS: Forty-two per cent of women used hard drugs during pregnancy. Increased probability of a positive maternal delivery HIV culture was significantly associated with prenatal hard drug use [odds ratio (OR), 3.08] and maternal cocaine use (OR, 2.98) among HIV-infected women with > 29% CD4+ lymphocytes. After adjusting for maternal culture positivity at delivery, CD4+ lymphocyte percentage and gestational age, significantly greater transmission risk was observed with hard drug use among women with membrane rupture > 4 h. CONCLUSIONS: On the basis of self-report and urine toxicology, overall maternal hard drug use and cocaine use in the WITS cohort were associated with maternal HIV culture positivity at delivery, and maternal hard drug use was associated with perinatal transmission.

Alcohol Drinking↗
PubMed1995

Mycobacterium tuberculosis infection in pregnant and nonpregnant women infected with HIV in the Women and Infants Transmission Study.

BACKGROUND: Prevalence of Mycobacterium tuberculosis (TB) infection and anergy were evaluated in a cohort of pregnant and nonpregnant women infected with the human immunodeficiency virus who were enrolled in a prospective natural history study (the Women and Infants Transmission Study) conducted in New York, NY; Boston and Worcester, Mass; Chicago, Ill; and San Juan, Puerto Rico. METHODS: One hundred eighty-three women (65 pregnant, 118 nonpregnant) were evaluated for TB. The TB history and risk factors were assessed by interview and medical record review. Intradermal skin testing with tuberculin, mumps, and tetanus antigens and CD4+ lymphocyte count were performed. RESULTS: Overall prevalence of TB infection or disease by documented medical history and/or a tuberculin skin test induration of 5 mm or more was 14% (26 of 183). History of TB infection or disease was documented in 11% of the women who were interviewed. Tuberculin and anergy skin test results were evaluable for 124 women; 6% (seven of 124) had tuberculin skin test induration of 5 mm or more, including 11% (five of 46) of the pregnant women who were tested. Induration between 2 and 5 mm was observed in four more women, three of whom were pregnant. Anergy was observed in 42% (52 of 124); prevalence of anergy was higher in nonpregnant women (38 [49%] of 78) than in pregnant women (14 [30%] of 46). While anergy was more common in women with a CD4+ cell count of 0.5 x 10(9)/L or less, 27% of those with a CD4+ cell count of more than 0.5 x 10(9)/L were also anergic. CONCLUSION: These data support current Public Health Service recommendations for tuberculin skin testing in persons infected with the human immunodeficiency virus, and emphasize that evaluation should include pregnant as well as nonpregnant women. The prevalence of anergy does not appear increased in pregnancy in women infected with the human immunodeficiency virus. Health care providers should include tuberculin and anergy skin testing as part of the standard prenatal care for women infected with the human immunodeficiency virus.

Adult↗
PubMed1995

Vibratory acoustic stimulation and fetal gasping.

OBJECTIVE: Vibratory acoustic stimulation (VAS) has been used to shorten the duration of antepartum fetal heart rate monitoring. Questions have been asked regarding the possible effects of VAS on the fetus. VAS was used to investigate whether the acute effect of VAS is associated with gasping in the normal fetus. STUDY DESIGN: Thirty-seven normal patients at 37-42 weeks' gestation with singleton fetuses were studied. All had normal amniotic fluid volume on ultrasound. These 37 subjects had a five-minute baseline sonographic assessment of fetal breathing and body movements. A fetal gasp was defined as an isolated, slow, irregularly occurring, deep, inspiratory-type movement, or series of them, of the chest and abdomen. Three-second VAS was then delivered with an artificial larynx placed directly over the fetal head. Fetal breathing, body and gasping movements were assessed at the time of this stimulus. RESULTS: A significant increase in fetal body movements (P < .001), a significant decrease in fetal breathing (P < .003) and absence of gasping movements were noted. CONCLUSION: The results suggest that gasping does not occur in response to VAS in the normal, term fetus.

Acoustic Stimulation↗
PubMed1994

Fetal breathing characteristics and postnatal outcome in cases of congenital diaphragmatic hernia.

OBJECTIVE: Our purpose was to determine characteristics of fetal breathing activity by recording fetal nasal fluid flow velocity in cases of congenital diaphragmatic hernia. STUDY DESIGN: Fetal breathing-related nasal fluid flow was studied in 47 patients at 34 to 41 weeks of gestation, 16 cases of antenatally diagnosed congenital diaphragmatic hernia and 31 cases of uncomplicated pregnancy. The examination was performed by ultrasonography combined with color-flow and spectral Doppler analysis. An average of 25 breath cycles from each case was determined for each of the following timing parameters: breath-to-breath interval, time of inspiration, time of expiration, and ratio of time of inspiration and time of expiration. RESULTS: In all cases with uncomplicated pregnancy fetal breathing-related nasal fluid flow was seen at the level of the nose, and the timing components of this flow were determined as control values. In two cases with diaphragmatic hernia no perinasal flow was demonstrated, although fetal breathing movements observed as chest wall movements were present. The other 14 cases with congenital diaphragmatic hernia who demonstrated perinasal flow had the following postnatal outcome: one stillbirth, five neonatal deaths (group I), and eight survived and were discharged (group II). The study revealed that the time of expiration (in milliseconds) in group II (493.2 +/- 34.3 SEM) was significantly (p = 0.0030) shorter than in group I (653.4 +/- 38.4) and in cases of uncomplicated pregnancy (633.6 +/- 18.5). The value of the time of inspiration/time of expiration ratio in group II was approximately 15% higher than in group I and approximately 30% higher than in cases of uncomplicated pregnancies. CONCLUSIONS: Observation of fetal breathing-related nasal fluid flow velocity in cases of antenatally diagnosed congenital diaphragmatic hernia provides a rationale for the hypothesis that time of expiration and the time of inspiration/time of expiration ratio may be useful in the prediction of postnatal outcome. We speculate that the changes in the group of survivors may represent a compensatory phenomenon by causing intermittent changes in the volume of fluid within the lungs.

Amniotic Fluid↗
PubMed1994

Transvaginal ultrasonographic evaluation of the cervix before labor: presence of cervical wedging is associated with shorter duration of induced labor.

OBJECTIVE: Our purpose was to test the hypothesis that transvaginal ultrasonographically determined characteristics of the cervix are associated with duration of induced labor. STUDY DESIGN: Fifty-three patients scheduled for induction of labor underwent transvaginal ultrasonography and digital cervical examinations before labor induction. Cox proportional-hazards multiple regression analysis was performed to determine the variables that made a significant contribution to the prediction of latent-phase and total labor duration. In the analysis the possible confounding effects of exogenous prostaglandin, previous vaginal delivery, and previous termination of pregnancy were controlled. RESULTS: Latent-phase and total labor duration were significantly associated with the presence of cervical wedging noted on transvaginal ultrasonography and administration of prostaglandin but not with the result of digital examination of cervical effacement or dilatation. Latent-phase duration was also associated with cervical length measured by transvaginal ultrasonography. The presence of wedging was significantly associated with shorter latent (15.9 +/- 1.7 vs 34.1 +/- 3.8 hours, p = 0.0001) and total (22.0 +/- 1.8 vs 38.3 +/- 3.6 hours, p = 0.0001) labor length. CONCLUSION: The presence of wedging and decreased cervical length observed by transvaginal ultrasonography is associated with a shorter duration of induced labor and may be useful in the evaluation of induction candidates.

Adult↗
PubMed1994

Ultrasound prediction of fetal pulmonary hypoplasia in pregnancies complicated by oligohydramnios and in cases of congenital diaphragmatic hernia: a review.

The objective of this review is to discuss the current knowledge of fetal pulmonary hypoplasia and to summarize the clinical significance of the many ultrasound methods for predicting pulmonary hypoplasia in pregnancies complicated by oligohydramnios due to spontaneous rupture of the fetal membranes and in cases complicated by fetal congenital diaphragmatic hernia. We concluded that the presence or absence of polyhydramnios, fetal breathing movements, mediastinal shift, thoracic position of the stomach, fetal breathing-related nasal and oropharyngeal fluid flow, ductal flow velocity modulation, and gestational age at onset and severity of ventricular disproportion as useful markers for predicting fetal pulmonary hypoplasia is a productive area for continued research. All studies show that there is a clear association between most of these markers and pulmonary hypoplasia. However, these markers have not been studied together in a large number of cases, and comparisons between each of the markers is unknown.

Animals↗
PubMed1994

The gynecologic contribution to intestinal obstruction in females.

This study was done to identify the cause of intestinal obstruction with particular emphasis on the gynecologic and perioperative related causes. All medical records from females with the discharge diagnosis "intestinal obstruction" from 1988 to 1991 at Columbia Presbyterian Medical Center were requested. The patient series consisted of the first 100 completed charts received. Forty-eight percent of those patients with intestinal obstruction had experienced a previous gynecologic or obstetric event that could account for the obstruction. Primarily, the gynecologist managed more than 20 percent of all female patients with intestinal obstruction. The most common causative factors contributing to intestinal obstruction were postoperative adhesions (59 percent) and tumor (17 percent). Fifty-six percent of the patients with intestinal obstruction associated with postoperative adhesions had a history of previous gynecologic and obstetric operation. Hysterectomy was the most common previously performed operation. In this series, cesarean section was less likely and myomectomy was more likely to cause subsequent intestinal obstruction than expected. Of 59 female patients with postoperative adhesions associated with intestinal obstruction, 31 had the original operative reports available for analysis. Eleven of these patients were taken to the operating room for management of the obstruction. In the nine patients who had surgical peritoneal closure in the original operation, the adhesions causing the obstruction were always to the site of reperitonealization. In the two patients in whom the peritoneum was left open, the adhesions causing obstruction were remote from the site of spontaneous reperitonealization. In an unselected patient series of intestinal obstruction, a history of previous gynecologic pathology is a significant factor contributing to the total number of instances of intestinal obstruction in females. Also, surgical peritoneal closure may result in an increase in the incidence of intestinal obstruction.

Adolescent↗
PubMed1993

Fetal upper respiratory tract function in cases of antenatally diagnosed congenital diaphragmatic hernia: preliminary observations.

Fetal upper respiratory tract function was studied in five cases of antenatally diagnosed congenital diaphragmatic hernia and in 16 cases of uncomplicated pregnancy at gestational ages ranging from 27 to 38 weeks. The evaluation of fetal upper respiratory tract function was performed using ultrasonography combined with color-flow and spectral Doppler analysis. In all cases with uncomplicated pregnancy, fetal breathing-related nasal and oropharyngeal fluid flow was seen at the level of the nose. The five cases with congenital diaphragmatic hernia all demonstrated fetal breathing activity by thoracic wall movement. In four of the fetuses, perinasal fluid flow was seen by the Doppler technique. The fetus with no demonstrated perinasal flow during breathing movements died in the early neonatal period and had pulmonary hypoplasia. Observation of the fetal breathing-related nasal and oropharyngeal fluid flow in cases of antenatally diagnosed congenital diaphragmatic hernia provides a rationale to hypothesize that the absence of this phenomenon is a useful marker for prenatal prediction of pulmonary hypoplasia.

Journal Article↗
PubMed1993

Fetal breathing-related nasal fluid flow velocity in uncomplicated pregnancies.

OBJECTIVE: Our purpose was to determine the Doppler ultrasonographic characteristics of fetal breathing-related nasal fluid flow velocity in uncomplicated pregnancies. STUDY DESIGN: Fetal nasal flow velocity was studied in 52 uncomplicated pregnancies at gestational ages ranging from 22 to 41 weeks. The evaluation of fetal breathing-related nasal fluid flow velocity was performed with ultrasonography combined with color flow and spectral Doppler analysis. RESULTS: The study revealed that the breath-to-breath interval and duration of the inspiratory phase of the fetal breathing-related nasal flow increased from 22 to 35 weeks and decreased thereafter. The breath-to-breath interval (milliseconds) at 33 to 35 weeks (1203.9 +/- 295.7 SD) was approximately twice what it was in the earliest age group (22 to 25 weeks); subsequently it decreased by approximately 25% in the term group (38 to 41 weeks). A positive correlation existed between the mean breathing-related nasal peak inspiratory flow velocity and advancing gestational age (r = 0.56, p = 0.0008), and between the inspiratory flow velocity acceleration and advancing gestational age (r = 0.53, p = 0.0076). CONCLUSION: Changes in fetal breathing activity during uncomplicated pregnancies can be determined by measurement of fetal breathing-related nasal fluid flow velocity. Our observations in uncomplicated pregnancies may be useful in future studies of these parameters in complicated pregnancies such as those at risk for pulmonary hypoplasia.

Adult↗
PubMed1993

Fetal movement in response to vibroacoustic stimulation: a review.

Fetal movement in response to vibroacoustic stimulation (VAST) depends on functional maturation of the fetal central nervous system and related to changes in fetal behavior. Researchers have associated the presence of fetal movement with fetal well-being. Use of the maternal perception of sound-provoked fetal movement as a test for predicting fetal health is questionable and may suggest further research. All studies show that there is a clear association between this test and favorable neonatal outcomes. This test is inexpensive and easily obtainable. However, because the test has not been studied on large numbers of patients and maternal reporting at times is biased, its adaptation for clinical use should cautiously wait for clear theoretical advantages.

Acoustic Stimulation↗