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Biomedical subjects

J Feldman

Publications and source records attributed to J Feldman.

At least 73 records · Page 4Linked to original sources
PubMed1998

Prevalence, risk factors, and accuracy of cytologic screening for cervical intraepithelial neoplasia in women with the human immunodeficiency virus.

OBJECTIVES: The objective was to evaluate the sensitivity and specificity of cervical cytology in women infected with the human immunodeficiency virus (HIV), risk factors for abnormal cytology in HIV-infected and uninfected women, and risk factors for histologic diagnosis of cervical intraepithelial neoplasia (CIN) in HIV-infected women. METHODS: Methods included a cross-sectional analysis of cervical cytology, colposcopic impression, and histology in 248 HIV-infected women and multivariate analyses of risk factors for abnormal cytology in 253 HIV-infected and 220 uninfected women and risk factors for CIN in 186 HIV-infected women. RESULTS: The sensitivity and specificity of cytology for all CIN grades were 0.60 and 0.80 and, for high-grade CIN, 0.83 and 0.74. The prevalence of abnormal cytology was 32.9% in HIV-infected and 7.6% in HIV-negative women. Independent risk factors for abnormal cytology were immunodeficiency [odds ratio (OR) 8-17, P < 0.001] and human papillomavirus (HPV) infection (OR = 5, P < 0.001). The prevalence of CIN on histology was 32% in HIV-infected women, and the only independent risk factor for CIN was oncogenic HPV type (OR = 5, P = 0.005). CONCLUSION: Given the high prevalence of abnormal cytology and CIN in HIV-infected women, cytologic screening has significant limitations. Both immunodeficiency and type of HPV infection are important risk factors.

Adult↗
PubMed1998

A longitudinal study of human papillomavirus carriage in human immunodeficiency virus-infected and human immunodeficiency virus-uninfected women.

OBJECTIVE: We sought to determine the relationship of human immunodeficiency virus serostatus to carriage of oncogenic human papillomavirus. MATERIAL AND METHODS: A total of 268 human immunodeficiency virus-infected and 265 human immunodeficiency virus-uninfected women were seen every 6 months, at which time they had laboratory tests performed including a CD4 count. Human papillomavirus deoxyribonucleic acid was analyzed by polymerase chain reaction. Statistical methods included Kaplan-Meier and Cox's proportional hazard models. RESULTS: The prevalence at baseline of any human papillomavirus type was 73% and 43% among human immunodeficiency virus-seropositive and seronegative women, respectively (p < 0.0001) and of oncogenic types was 32.5% and 17.0% (p < 0.001). The prevalence of oncogenic human papillomavirus was higher in women with CD4 counts <200 mm3 (p < 0.001). The rate of detection of new oncogenic human papillomavirus per 100 patient years of follow-up in human immunodeficiency virus-seropositive women was almost three times higher than among human immunodeficiency virus-seronegative women (p < 0.01). The rate of loss of an oncogenic human papillomavirus was higher in the human immunodeficiency virus-seronegative women but the difference was not significant. The relative risk of a human immunodeficiency virus-infected woman who did not initially have a specific type of oncogenic human papillomavirus having one detected during follow-up was 6.6 times greater than among human immunodeficiency virus-negative women (p < 0.001). CONCLUSIONS: Human immunodeficiency virus-seropositive women are more likely to have newly detectable oncogenic types of human papillomavirus at follow-up and to show persistent carriage of oncogenic types of human papillomavirus types. Among human immunodeficiency virus-infected women, those with higher CD4 counts were more likely to have a newly detected oncogenic human papillomavirus during follow-up.

CD4 Lymphocyte Count↗
PubMed1998

Reproductive health hospitalizations among women with human immunodeficiency virus infections.

OBJECTIVE: Our goal was to determine types of inpatient admissions among human immunodeficiency virus-infected women both before and after the human immunodeficiency virus diagnosis, so that we might outline opportunities for intervention. STUDY DESIGN: A total of 292 human immunodeficiency virus-infected women were interviewed about the reproductive history and prior hospitalizations. A reproductive health hospitalization was defined as either an obstetric admission or a gynecologic admission. Other admissions were categorized as either human immunodeficiency virus related, possibly human immunodeficiency virus related, or not human immunodeficiency virus related. Assignments were made independently by two human immunodeficiency virus specialists. If there was a conflict, a third reviewer was used. RESULTS: In the 10 years before study entry 44.4% of women had at least one obstetric admission, 30.4% had at least one gynecologic admission, 3.1% had at least one human immunodeficiency virus-related admission, 18.1% had at least one admission that was possibly human immunodeficiency virus related, and 13.3% had at least one admission that was not human immunodeficiency virus related. Overall, 226 (77%) women had been admitted to the hospital; of these, 201 (69%) had been admitted for reproductive health reasons. Similar patterns were seen in the year before diagnosis and the time after diagnosis. Reproductive health admissions were more common among women who were younger, who used drugs, and who had higher CD4+ cell counts. CONCLUSION: Women with human immunodeficiency virus infection are often admitted to hospitals for reproductive health reasons before and after the human immunodeficiency virus status is known. Clinicians providing reproductive health care must be actively engaged in efforts to reduce the heterosexual and perinatal transmission of human immunodeficiency virus, to identify human immunodeficiency virus-infected women early in the course of the disease, and to provide ongoing care to human immunodeficiency virus-infected women.

Adult↗
PubMed1998

Hepatitis B vaccination program at a New York City hospital: seroprevalence, seroconversion, and declination.

BACKGROUND: Despite implementation of hepatitis B vaccination programs, 2 problems have prevented full vaccine-induced protection of health care workers (HCWs). About 10% to 12% of vaccinated HCWs do not develop antibody, and many HCWs continue to decline vaccination. To determine the effectiveness of our hepatitis B vaccine program, we studied rates of postvaccination seroconversion and vaccine declination. METHODS: Employee health service records were used to determine demographic features, hepatitis B surface antibody serostatus at baseline, serologic response to vaccine, and declination or acceptance of vaccine. RESULTS: About 26% of HCWs were seropositive at baseline, including those vaccinated before employment. Higher seroprevalence rates were seen among those born outside the United States, nurses, and laboratory workers. Seroconversion occurred in only 79% of HCWs who completed a 3-vaccine series. Increasing age was the only significant risk for failure to convert. Declination rates overall were about 45% and were lowest in HCWs who have jobs that included potential exposure to blood. CONCLUSION: Hepatitis B seroprevalence among HCWs at our hospital is higher than in many other urban hospitals in the United States; over postvaccination seroconversion rate is substantially lower; and our declination rate of 45% resembles other published series. Declination of vaccine and failure to respond to vaccine continue to thwart achievement of full control of this preventable occupational infection.

Adult↗
PubMed1998

Mapping the mental space of rectangles.

The cognitive structure of a shape space--the space of rectangles--is explored by a nonmetric scaling technique. Our experiment was designed to extract the major transformational paths or 'modes' that characterize the mental shape space. Earlier studies of rectangle similarities using multidimensional scaling have provided conflicting evidence about whether the coordinate system of the mental rectangle space is based on height and width or on area and shape (i.e. aspect ratio). Our study reveals shape to be the single dominant factor. We suspected that earlier evidence for a height-width parameterization might have been due to the presentation of rectangles upright in a pseudo-gravitational coordinate system (whereas our rectangles are randomly rotated). In a control experiment with upright (vertical or horizontal) rectangles, the heavy bias towards shape preservation was still the dominant mode. In addition, however, a secondary bias towards change of height or width emerged, exactly following the pattern expected from the biasing change in context. This finding established a concrete path by which context and frame can influence the way shape is represented. The relevance of these findings to the cognitive organization of more complex shape spaces is discussed.

Cognition↗
PubMed1998

The relationship of cocaine use and human immunodeficiency virus serostatus to incident sexually transmitted diseases among women.

BACKGROUND AND OBJECTIVES: To assess the incidence of sexually transmitted diseases (STD) in a group of heterosexual women as a function of human immunodeficiency virus (HIV) serostatus and to ascertain the effect of crack cocaine use on these relationships. STUDY DESIGN: At baseline, 445 HIV type 1 (HIV-1) seronegative and 232 seropositive women were provided interviews ascertaining demographic and behavioral risk factors. All participants were tested for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis at baseline and at 6-month intervals. RESULTS: HIV serostatus was not related to STD incidence. Although HIV-positive women reported more condom use than did HIV-negative women (P < .01), only 65% reported using them consistently. Increases in the frequency of crack cocaine use, measured on a 4-point scale, were positively associated with rates of new STDs (relative risk [RR] = 1.23, P < .01). Crack cocaine use was also associated with greater numbers of sexual partners and less consistent condom use. The relationship between HIV status and the probability of acquiring an STD was not influenced by frequency of crack use. CONCLUSION: Women infected with HIV or who use crack cocaine are at risk for transmitting HIV and acquiring other STDs. Whether women are infected with or at risk for HIV, programs are needed to prevent and treat crack addiction. Interventions should target high-risk sexual practices among both female crack users and women living with HIV.

Adult↗
PubMed1998

Gathering support.

Explore the source record for details and available documents.

Adaptation, Psychological↗
PubMed1998

Autonomic nervous system as a target for cardiovascular drugs.

1. Drugs acting within the autonomic nervous system (ANS) are of particular interest when autonomic abnormalities are implicated in the development and maintenance of various cardiovascular pathologies. For example, it has been documented that in the early stages of hypertensive disease (i.e. hyperkinetic borderline hypertension) a sympathetic hyperactivity associated with a decreased parasympathetic activity results in increased cardiac output and heart rate. 2. Several classes of drugs acting within the central, as well as the peripheral ANS, are very efficient in treating hypertensive disease. One of these classes of drugs, the second generation of centrally acting drugs, has proved beneficial in this respect because, in addition to their therapeutic efficacy, these drugs are well tolerated. 3. The central nervous system may also be the target for drugs with the potential to treat other cardiovascular diseases. Some recent experimental and clinical data supporting such new perspectives concerning idiopathic dysrhythmias, angina pectoris and congestive heart failure will be summarized.

Animals↗
PubMed1998

The Women's Interagency HIV Study. WIHS Collaborative Study Group.

The Women's Interagency HIV Study comprises the largest U.S. cohort to date of human immunodeficiency virus (HIV)-seropositive women (N = 2,058) with a comparison cohort of seronegative women (N = 568). The methodology, training, and quality assurance activities employed are described. The study population, enrolled between October 1994 and November 1995 through six clinical consortia throughout the United States (totaling 23 sites) represents a typically hard-to-reach study population. More than half of the women in each cohort were living below the federally defined levels of poverty. The women ranged in age from 16 to 73 years; approximately one-quarter self-identified as Latina or Hispanic, over one-half as African-American not of Hispanic origin, and less than 20% as white, non-Hispanic origin. Self-reporting of HIV exposure risk included injection drug use by 34% of the seropositive women and 28% of the seronegative women, heterosexual contact (42% vs 26%), transfusion risk (4% vs 3%) and no identified risk (20% vs 43%). Demographic and HIV exposure risk characteristics of the seropositive cohort were comparable with characteristics of nationally reported AIDS cases in U.S. women. This well characterized cohort of HIV-seropositive and high-risk seronegative women represents a rich opportunity for future studies of HIV disease progression and pathogenesis.

Adolescent↗
PubMed1998

I1-imidazoline receptors: an update.

BACKGROUND: The site of the hypotensive action of imidazoline compounds, such as clonidine, was first identified within the nucleus reticularis lateralis of the rostroventrolateral part of the medulla (NRL/RVLM). It was shown that imidazolines and related substances reduced blood pressure when applied in this area whereas no catecholamine was capable of such an effect. IMIDAZOLINE-SPECIFIC BINDING: We previously suggested the existence of receptors specific for imidazoline-like compounds that differed from the alpha-adrenergic receptors. Imidazoline-binding sites were subsequently reported in the brain and in a variety of peripheral tissues, including the human kidney, and as expected these specific binding sites do not bind the catecholamines. The imidazoline-binding sites are classified into two subgroups: the I1-type, which is sensitive to clonidine and idazoxan, and the I2-type, sensitive to idazoxan and largely insensitive to clonidine. Numerous studies have confirmed the involvement of these receptors in various regulations and pathological processes, hypertension being the most notable. DRUGS: Functional studies have confirmed that the hypotensive effects of clonidine-like drugs involve I1-imidazoline receptors while their most frequent side effects only involve alpha2-adrenergic receptors. Recent studies have shown that a contribution of both receptor types might be necessary to trigger the hypotensive effect of central origin. Rilmenidine, an oxazoline analogue to the imidazolines, has been proposed as the prototype of a new class of antihypertensive drugs selective for I1-imidazoline receptors. At hypotensive doses, this drug is devoid of any significant sedative effect. As with clonidine, it evokes hypotension when injected into the NRL region and it completely displaces the [3H]clonidine bound to specific imidazoline-binding sites in human medullary membrane preparations, but it has proved more selective for cerebral imidazoline receptors than clonidine. This selectivity might explain the low incidence of side effects evoked by rilmenidine. CONCLUSION: Rilmenidine is the first example of a drug exhibiting a favourable selectivity between I1-imidazoline receptors and alpha2-adrenergic receptors, for example reducing blood pressure but avoiding sedation and mouth dryness.

Animals↗
PubMed1998

Preventive effect of rilmenidine on the occurrence of neurogenic ventricular arrhythmias in rabbits.

BACKGROUND: Centrally acting antihypertensive drugs bearing an imidazoline or a related chemical structure inhibit sympathetic nervous output to the heart and vascular beds, and enhance parasympathetic tone. Cardiac ischaemia and ventricular arrhythmias that can result from hypertension are likely to benefit from such effects. OBJECTIVE: To investigate the effects of rilmenidine, an oxazoline with antihypertensive properties, in a model of neurogenically induced ischaemic ventricular arrhythmias. METHODS AND RESULTS: Bicuculline, a alpha-aminobutyric acid (GABA(A)) receptor antagonist, was administered intracisternally in pentobarbitone anaesthetized rabbits; 10 microg/kg intracisternal bicuculline induced polymorphic ventricular ectopic beats and ventricular tachycardia, while blood pressure increased by about 50-60% and heart rate in sinus rhythm decreased by about 20%. Rilmenidine pretreatment (10 min), either administered intravenously (0.01, 0.1, 1 mg/kg) or intracisternally (3, 10, 30 microg/kg), dose-dependently prevented the occurrence of bicuculline-induced arrhythmias and, because of a lower baseline, the blood pressure values reached were less when compared with controls. Intracisternal idazoxan (15 microg/kg) had no significant antiarrhythmic effect but antagonized, in part, the haemodynamic and antiarrhythmic effects of rilmenidine (1 mg/kg intravenously; 30 microg/kg intracisternally). CONCLUSION: The antiarrhythmic effects observed with rilmenidine are mainly mediated by blunting the bicuculline-induced increase in the sympathetic nervous output to the heart and the vascular beds. These effects of rilmenidine are likely to originate from action on the central as well as on the peripheral nervous systems. Direct coronary or cardiac effects might also play a role, in particular at low non-hypotensive intravenous doses.

Animals↗
PubMed1997

Serotonergic inhibition of phrenic motoneuron activity: an in vitro study in neonatal rat.

In vitro experiments were conducted on neonatal rat brainstem-spinal cord preparations to test the hypothesis of an inhibitory modulation of phrenic activity by serotonin (5-HT) via non-5-HT2A receptors [Lindsay, A.D. and Feldman, J.L., Modulation of respiratory activity of neonatal rat phrenic motoneurones by serotonin, J. Physiol., 461 (1993) 213-233]. The changes induced by 5-HT and related agents on phrenic root discharges and membrane currents in identified phrenic motoneurons were analysed after blockade of spinal 5-HT2A receptors. Spinal application of 5-HT1B (but not 5-HT1A) receptor agonists depressed the phrenic activity and the effect was prevented by pretreatment with 5-HT1B (but not 5-HT1A, 5-HT2A and 5-HT3) receptor antagonists. Results from phrenic motoneuron whole cell recordings do not reject a presynaptic location of the 5-HT receptors responsible for this depression.

Action Potentials↗
PubMed1997

[Rheumatoid arthritis in the elderly].

Opinions differ as to whether late onset rheumatoid arthritis (RA) represents a clinical subset and whether age at onset involves differences in therapy and prognosis. In this retrospective study we compared 23 patients with early onset RA (average onset 52.8 years; 91.3% of them women), with 36 with late onset (average onset 70.3 years; 67% of them women). No statistically significant differences were found as to demographic, clinical, laboratory or radiographic characteristics.

Age of Onset↗
PubMed1997

The Structure of Perceptual Categories

When presented with a small set of sample objects, human observers have the striking capacity to induce a more general class. Generalization can even proceed from a single object ("one-shot categorization"). The inference is apparently guided by the principle that a good categorical hypothesis is one in which the observed object would be a typcal, "non-accidental," or generic example; this idea is formalized here as the Genericity Constraint. In the theory proposed here, each categorical hypothesis is a "generative model," a sequence of transformations by which the object is interpreted as having been created; objects are considered to be in the same category if they were created by the same set of operations. The set of all available category models can be explicitly enumerated in a lattice, an explicit structure that partially orders the models by their degree of regularity or genericity-more abstract models are higher in the lattice, and more regular or constrained models are lower. The Genericity Constraint dictates that among all the models on the lattice that apply, the observer should choose the one in which the observed object is generic, which is simply the lowest in the partial order. A series of experiments are reported in which subjects are asked to generalize from simple figures. The results corroborate the role of the lattice and the Genericity Constraint in subjects' interpretations

Journal Article↗
PubMed1997

Immune compromise and prevalence of Candida vulvovaginitis in human immunodeficiency virus-infected women.

OBJECTIVE: To investigate the effect of human immunodeficiency virus (HIV) infection on vaginal yeast colonization and symptomatic vulvovaginitis and to explore the effects of immune compromise on these conditions in HIV-positive women. METHODS: Between September 1991 and May 1993, 223 HIV-positive women without AIDS-defining conditions were enrolled for prospective follow-up and compared with 289 HIV-negative women enrolled in a concurrent study. Standardized gynecologic assessment was carried out. RESULTS: Cultures from 81 of 223 (36%) HIV-positive women and 72 of 289 (25%) HIV-negative women were positive for any yeast. The most commonly isolated yeasts were Candida albicans and Torulopsis glabrata; the proportion of non-C albicans isolates (26%) did not differ by serostatus. The rates of C albicans colonization and vulvovaginitis among immunocompetent (CD4 count at least 500 cells/mm3) HIV-positive women did not differ from those among HIV-negative women. Among HIV-positive women, risks for colonization and for symptomatic vulvovaginitis were increased approximately threefold and fourfold respectively, in women with CD4 counts below 200 cells/mm3 compared with either immunocompetent HIV-positive women or HIV-negative women. CONCLUSION: The yeast species isolated from HIV-positive and HIV-negative women were similar. Rates of vaginal colonization and vaginitis were similar among nonimmunocompromised HIV-positive women and HIV-negative women. Elevated rates of yeast colonization and vaginitis were not seen among this population of HIV-infected women before immune compromise. Both vaginal colonization and symptomatic vaginitis increased with immune compromise among HIV-positive women, especially at CD4 counts below 200 cells/mm3.

AIDS-Related Opportunistic Infections↗
PubMed1997

Curvilinearity, covariance, and regularity in perceptual groups.

A curvilinear pattern among a series of visual items (e.g., dots) can be regarded as a kind of probabilistic inference, in which each consecutive angle, regarded independently, is more nearly collinear than would be expected by chance alone. This paper investigates judgments of curvilinearity as a function of the joint distribution of successive inter-dot angles. Subjects were asked to classify 4- and 5-dot configurations as having been generated by a curvilinear generating process, vs independently. Their results are distributed as a gaussian over the inter-dot angles with mean 0 deg (collinear), with a negative correlation between successive angles, but negligible correlation between non-successive angles. This suggests that curvilinearity is evaluated in a 4-dot window moving along the chain of dots, evaluating collinearity and smoothness but ignoring higher-order relationships. Moreover, the probabilistic model provides a remarkably precise numeric prediction of the magnitude of the correlation. Subjects also showed a reliable preference for equal spacing of dots along the virtual curve.

Humans↗