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Biomedical subjects

J Cross

Publications and source records attributed to J Cross.

At least 37 records · Page 2Linked to original sources
PubMed1998

Novel potentiation of interleukin 1alpha production in endotoxin-stimulated IC-21 cells by ambient pressure augmentation.

BACKGROUND: We hypothesized that increased ambient pressure would increase the production of interleukin 1alpha by endotoxin-stimulated macrophages, based on the clinical observation that patients with "pus under pressure" demonstrate systemic toxic effects (a priori hypothesis). DESIGN AND SETTING: In vitro experiment in the laboratory. INTERVENTIONS: A murine macrophage line, IC-21 cells, was seeded into 6-well plates, 25 x 10(4) cells per well. Cells were incubated under atmospheric (ATM) or increased (ATM+60 mm Hg) ambient pressure (AP) in the presence or absence of endotoxin (lipopolysaccharide [LPS]). The IC-21 production of interleukin 1alpha was determined at 2, 4, 8, and 12 hours. Four groups were examined: group 1: AP ATM, no LPS; group 2: AP ATM+60 mm Hg, no LPS; group 3: AP ATM and LPS, 500 ng/mL; and group 4: AP ATM+60 mm Hg and LPS, 500 ng/mL. MAIN OUTCOME MEASURES: The IC-21 production of interleukin 1alpha. RESULTS: Interleukin 1alpha production at 2, 4, 8, and 12 hours (mean [+/-SD] picograms per 10(6) cells) was as follows: group 1: 3.0 (+/-5.9), 8.1 (+/-10.3), 50.5 (+/-51.1), and 6.1 (+/-4.1), respectively; group 2: 228.7 (+/-110.2), 141.0 (+/-141.8), 112.5 (+/-98.5), and 118.2 (+/-79.8), respectively; group 3: 37.2 (+/-13.3), 191.5 (+/-86.5), 627.3 (+/-184.3), and 600.7 (+/-67.1), respectively; and group 4: 601.2 (+/-49.9), 1050.9 (+/-190.6), 2684.2 (+/-562.2), and 3144.7 (+/-388.4), respectively. The production of IL-1alpha by group 3 was significantly greater (P<.04, unpaired Student t test) at 4, 8, and 12 hours than that by groups 1 or 2. Likewise, the production of IL-1alpha by group 4 was significantly greater (P<.001, unpaired Student t test) at all time points than that by groups 1, 2, or 3. CONCLUSIONS: Our data support the hypothesis that pressure may be a novel potentiator of the macrophage proinflammatory cytokine response to endotoxin. This provides a possible explanation for the phenomenon of systemic illness seen with "pus under pressure."

Animals↗
PubMed1996

Effect of frequency of prenatal care visits on perinatal outcome among low-risk women. A randomized controlled trial.

OBJECTIVES: In 1989, the Expert Panel on the Content of Prenatal Care established guidelines on the timing and content of prenatal care, including a schedule consisting of fewer prenatal visits than traditionally provided, for women at low risk of adverse perinatal outcomes. We tested the hypothesis that there are no significant increases in adverse perinatal outcomes when low-risk women are seen in a prenatal care visit schedule of fewer visits than routinely advised. DESIGN: Randomized controlled trial. SETTING: Group-model health maintenance organization. PATIENTS: A total of 2764 pregnant women, judged to be at low risk of adverse perinatal outcomes. INTERVENTIONS: Following risk assessment, participants were randomly assigned to an experimental schedule (nine visits) or a control schedule (14 visits) with additional visits as indicated or as desired by the patient. MAIN OUTCOME MEASURES: Preterm delivery, preeclampsia, cesarean delivery, low birth weight and patient's satisfaction with care. RESULTS: On average, there were 2.7 fewer visits observed in the experimental group than in the control group. There were no significant increases in the main outcomes of the experimental group; preterm delivery (relative risk [RR], 1.08; 95% confidence interval [CI], 0.92 to 1.27; P = .19), preeclampsia (RR, 0.94; 95% CI, 0.78 to 1.14, P = .74), cesarean delivery (RR, 1.04; 95% CI, 0.93 to 1.17; P = .25), and low birth weight (RR, 0.94; 95% CI, 0.78 to 1.12; P = .76). There were no differences between the two groups in patients' satisfaction with quality of prenatal care. CONCLUSION: In this study, good perinatal outcomes and patient satisfaction were maintained when the prenatal visit schedule proposed by the Expert Panel on the Content of Prenatal Care was observed.

Adult↗
PubMed1996

Inactivation of Fac in mice produces inducible chromosomal instability and reduced fertility reminiscent of Fanconi anaemia.

Fanconi anaemia (FA) is an autosomal recessive disease characterized by bone marrow failure, variable congenital malformations and predisposition to malignancies. Cells derived from FA patients show elevated levels of chromosomal breakage and an increased sensitivity to bifunctional alkylating agents such as mitomycin C (MMC) and diepoxybutane (DEB). Five complementation groups have been identified by somatic cell methods, and we have cloned the gene defective in group C (FAC)(7). To understand the in vivo role of this gene, we have disrupted murine Fac and generated mice homozygous for the targeted allele. The -/- mice did not exhibit developmental abnormalities nor haematologic defects up to 9 months of age. However, their spleen cells had dramatically increased numbers of chromosomal aberrations in response to MMC and DEB. Homozygous male and female mice also had compromised gametogenesis, leading to markedly impaired fertility, a characteristic of FA patients. Thus, inactivation of Fac replicates some of the features of the human disease.

Animals↗
PubMed1996

Molecular phylogenetic analysis of Cyclospora, the human intestinal pathogen, suggests that it is closely related to Eimeria species.

A coccidian organism assigned to the genus Cyclospora has been increasingly recognized in association with prolonged diarrhea in humans throughout the world. Confusion surrounds the taxonomy of this fastidious organism, despite the availability of morphology and sporulation characteristics. The small subunit rRNA coding region from cyclosporan oocysts purified from a human fecal specimen was amplified and sequenced. The same sequence was present in specimens from 8 other patients with cyclosporan oocysts but absent in specimens from asymptomatic subjects and from cryptosporidiosis patients. Phylogenetic analysis of rDNA sequences reveals that the human-associated Cyclospora is closely related to members of the Eimeria genus. These results allow predictions concerning Cyclospora host specificity, life cycle, and epidemiology as well as the development of a specific polymerase chain reaction-based diagnostic assay.

Animals↗
PubMed1996

Diet in pregnancy and the offspring's blood pressure 40 years later.

OBJECTIVE: To determine how diet of the mother in pregnancy influences the blood pressure of the offspring in adult life. DESIGN: A follow up study of men and women born during 1948-1954 whose mothers had taken part in a survey of diet in late pregnancy. SETTING: Aberdeen, Scotland. POPULATION: Two hundred and fifty-three men and women born in Aberdeen Maternity Hospital. MAIN OUTCOME MEASURE: Systolic and diastolic blood pressure. RESULTS: The relations between the diet of mothers and their offsprings' blood pressure were complex. When the mothers' intake of animal protein was less than 50 g daily, a higher carbohydrate intake was associated with a higher blood pressure in the offspring (a 100 g increase in carbohydrate being associated with a 3 mmHg increase in systolic pressure (P = 0.02)). At daily animal protein intakes above 50 g, lower carbohydrate intake was associated with higher blood pressure (a 100 g decrease in carbohydrate being associated with an 11 mmHg rise in systolic blood pressure (P = 0.004)). These increases in blood pressure were associated with decreased placental size. CONCLUSION: Mothers' intakes of animal protein and carbohydrate in late pregnancy may influence their offsprings' adult blood pressure. This may be mediated through effects on placental growth.

Adult↗
PubMed1995

Prostate-specific membrane antigen: evidence for the existence of a second related human gene.

Prostate-specific membrane antigen (PSM) is a glycoprotein recognised by the prostate-specific monoclonal antibody 7E11-C5, which was raised against the human prostatic carcinoma cell line LNCaP. A cDNA clone for PSM has been described. PSM is of clinical importance for a number of reasons. Radiolabelled antibody is being evaluated both as an imaging agent and as an immunotherapeutic in prostate cancer. Use of the PSM promoter has been advocated for gene therapy applications to drive prostate-specific gene expression. Although PSM is expressed in normal prostate as well as in primary and secondary prostatic carcinoma, different splice variants in malignant tissue afford the prospect of developing reverse transcription-polymerase chain reaction (RT-PCR)-based diagnostic screens for the presence of prostatic carcinoma cells in the circulation. We have undertaken characterisation of the gene for PSM in view of the protein's interesting characteristics. Unexpectedly, we have found that there are other sequences apparently related to PSM in the human genome and that PSM genomic clones map to two separate and distinct loci on human chromosome 11. Investigation of the function of putative PSM-related genes will be necessary to enable us to define fully the role of PSM itself in the development of prostatic carcinoma and in the clinical management of this malignancy.

Antigens, Neoplasm↗
PubMed1994

The average daily energy expenditure of elderly males and females.

The aim of this study was to report on the average daily energy expenditure by elderly males and females in their normal day-to-day activities. The study was based on an analysis of data collected over six months from daily diary recording of activities. The subjects, 82 males and 93 females, were non-institutionalized volunteers with a mean age of 68 years. A multivariate analysis of variance indicated that there were no differences between males and females in total mean daily energy expended on Sporting activities. Females expended twice as much energy as males on Household Chores (F = 36.3,p < 0.001). Males expended over three times as much energy as females on gardening (F = 56.7, p < 0.001) and over seven times as much on Maintenance (F = 53.6, p < 0.001). There were also differences between males and females on energy expended while Walking (F = 6.1, p < 0.02) and on Miscellaneous activities (F = 6.3, p<0.05). It is concluded that sex stereotypical roles for activities required at younger ages are continued into old age. The implications of these findings for prescribing regular exercise in the elderly are discussed, indicating specific activities that might prove to be beneficial.

Aged↗
PubMed1994

Latex allergy in hospital employees.

To investigate the incidence of latex IgE-mediated hypersensitivity, 224 hospital employees were interviewed and prick skin tests were performed to six common aeroallergen extracts, one non-latex "synthetic" glove extract, and four different latex glove extracts. Of the 224 subjects, there were 136 nurses, 41 laboratory technicians, 13 dental staff, 11 physicians, 6 respiratory therapists, and 17 housekeeping and clerical workers. All 224 subjects tested negative for the nonlatex glove (Tactylon) extract but 38 (17%) tested positive for latex extracts. The incidence ranged from 0% in housekeeping staff to 38% in dental staff. Eighty-four percent of the latex skin test-positive employees complained of itching and 68% of rash upon exposure to latex, whereas the latex skin test-negative employees reported these symptoms in 29% and 17%, respectively. Urticaria was a symptom in 55% of the latex skin test-positive and 0.5% of the skin test negative-subjects. Anaphylaxis occurred in 10.5% of the skin test-positive and in none of the skin test-negative employees. Symptoms of sneezing (34% vs 7%), nasal congestion (39% vs 7%), and lacrimation and ocular itching (45% vs 6%) were also significantly different between the latex skin test-positive and latex skin test-negative subjects. We conclude that the incidence of latex IgE-mediated allergy in hospital employees is 17%. The symptoms of anaphylaxis and hives when using latex gloves are sensitive predictors of IgE-mediated latex allergy.

Female↗
PubMed1993

Echocardiographic description of the CarboMedics bileaflet prosthetic heart valve.

OBJECTIVES: The aim of this study was to describe the echocardiographic appearance of the normal CarboMedics prosthesis in the aortic and mitral positions. BACKGROUND: Echocardiography is the standard method of assessing prosthetic valves. However, new valve designs may still be marketed without an accompanying echocardiographic description. The CarboMedics prosthesis is in widespread use, but few noninvasive hemodynamic data have been published. METHODS: Echocardiography was performed in 147 patients with a total of 96 normally functioning CarboMedics prostheses in the aortic position and 75 in the mitral position; in 24 patients, valves were implanted in both positions. The following variables were measured: peak and mean transvalvular velocities, peak and mean instantaneous gradient estimated from the modified Bernoulli equation, aortic acceleration slope, pressure half-time, transvalvular flow and effective orifice area using the continuity equation. Patterns of regurgitation were observed by transthoracic study in all valves and by transesophageal study in selected mitral valve prostheses. RESULTS: For the aortic valve prostheses, estimated mean gradient ranged between 6 and 19 mm Hg. Effective area differed markedly among the anulus diameters (p < 0.001), with a mean value of 1 cm2 for the 19-mm valve and 2.6 cm2 for the 29-mm valve. For the mitral valve prostheses, mean gradient ranged from 3 to 7 mm Hg. There were a total of four washing leaks, one on either side of each pivotal point, and these lasted throughout systole or diastole. One jet was commonly more prominent than the other three. CONCLUSIONS: The CarboMedics prosthesis offered relatively little resistance to forward flow except at small anulus diameters. The washing jets were prominent and would be easy to misdiagnose as a sign of paraprosthetic regurgitation.

Aortic Valve↗
PubMed1992

Evaluation of latex allergy in patients with meningomyelocele.

Seventy-six patients with meningomyelocele were evaluated for latex sensitivity by medical history and epicutaneous skin testing. Four different latex glove extracts, two nonlatex glove extracts, cornstarch, selected inhalant antigens, and negative and positive controls were used for skin testing. Forty-nine patients (64.5%) were skin test positive to latex extracts (latex-positive group). Twenty-four patients (49%) of the latex-positive group and none of the latex-negative group had histories of immediate reactions to latex products (P less than .001). The latex-positive group had a higher mean number of surgical procedures, 12.67 +/- 11.27, compared with 6.89 +/- 6.55 (P less than .001) in the latex-negative group. Twenty-three of the latex-positive patients (47%) used latex products daily compared to seven patients (26%) in the latex-negative group (P = .073). Twenty latex-positive patients (41%) had atopy compared with five patients (19%) of the latex negative group (P = .041). There was no significant difference between the two groups in age, sex, daily catheterization, or positive skin tests to cornstarch. All 76 patients tested negative to the nonlatex glove extracts. Ten control subjects tested negative for all latex and nonlatex glove extracts.

Adolescent↗
PubMed1991

Gambling and pathological gambling among university students.

Students from six colleges and universities in five states in the U.S. (New York, New Jersey, Oklahoma, Texas, and Nevada) were surveyed concerning their gambling behavior and the rate of pathological gambling. Type of gambling varied by state, with students in the northeast and Nevada gambling more than students in Oklahoma and Texas. Over 90% of males and 82% of females had gambled. One third of the males and 15% of females gambled once a week or more. Rates of pathological gambling ranged from 8% in New York to 4% in Nevada. The incidence of pathological gambling was high among males, Hispanics, Asians, and Italian-Americans (compared with among other whites), students with non-traffic arrests, those with parents who have gambling problems, and those who abuse alcohol and other drugs. Pathological gambling was only weakly correlated with age, religion, lower grade point average in school, overeating, living in neighborhoods that are "poorer than most," family income, and parental drug use. It was not correlated with academic year in college, marital status, parental occupation, parental alcohol, and bulimic behavior. The implications of the findings for further research and social policy are discussed.

Achievement↗
PubMed1989

Relationship of racial stressors to blood pressure responses and anger expression in black college students.

The physiological effects of racism, as a stressor, were examined as they related to blood pressure (BP) and anger experiences in Black college students. Current research has failed to consider the stressful effects of racism as a factor contributing to the higher incidence of essential hypertension among Blacks. Twenty-seven Black college students viewed three excerpts showing racist situations involving Blacks; anger-provoking, nonracist situations; and neutral situations. After each scene, BP was taken, and a mood checklist was administered. The Framingham Anger Scale and the Anger Expression Scale were administered. Analyses revealed that BP significantly increased during the presentation of racist stimuli but not of anger-provoking or neutral stimuli. Self-reports of state anger, as measured by the mood checklist, were significant for both the anger-provoking and racist stimuli. BP scores were significantly correlated to the two trait anger measures. Exposure to racist stimuli was associated with BP increases among Blacks. Such cumulative exposure to racism may have important implications for the etiology of essential hypertension.

Adaptation, Psychological↗