Biomedical subjects

B Greenberg

Publications and source records attributed to B Greenberg.

At least 37 records · Page 2Linked to original sources

PubMed2000

Risk factors and characteristics of youth living with, or at high risk for, HIV.

Over 8,000 adolescents and young adults (4,111 males; 4,085 females) reported on several HIV-related risk behaviors during enrollment into 10 service demonstration projects targeted to youth living with, or at risk for, HIV. Distinct risk patterns emerged by gender when predicting HIV serostatus (versus unknown serostatus/negative serostatus). Males who had injection drug risk histories, had sex with an HIV positive partner, had sexually transmitted diseases, had sex with males, and/or were homeless had an inflated risk of being HIV positive. Females who engaged in sex with an HIV partner, had sex with an injection drug user, and/or had sexually transmitted diseases, were at the highest HIV risk. For both samples, engaging in sex with women reduced the likelihood of HIV positive status. Very basic information about risk factors obtained at service intake offers important information about HIV status of "high risk" youth presenting for care in community programs, as well as suggests clear risk factors for targeted preventive efforts.

Adolescent↗

PubMed1999

Gender differences in HIV risk behaviors in an adult emergency department in New York City.

BACKGROUND: The human immunodeficiency virus (HIV) epidemic in the US increasingly involves urban heterosexual adults, particularly women, belonging to ethnic minority groups. An understanding of gender-based differences in HIV risk behaviors within these groups would be of value in the ongoing struggle to limit HIV transmission in metropolitan centers. METHODS: This was a prospective study of demographic and historical characteristics and HIV risk behaviors. The study utilized a structured interview format, which was administered to all patients treated by participating emergency department physicians. RESULTS: On univariate analysis of data obtained from 1,460 patients who had neither a known HIV infection nor a chief complaint or final emergency department diagnosis associated with HIV risk behaviors, men were more likely to be older, homeless, to have ever injected drugs, used crack, engaged in same-gender sex, paid for sex, been incarcerated, or had syphilis or gonorrhea. Women were more likely to report prior chlamydia infection or to report that their sole sex partners had other partners within the past year. On multivariate analysis, variables independently associated with male gender included homelessness, injection drug use, crack use, any prior sexually transmitted disease (in subjects 35 years of age or older), and sex with prostitutes. In a separate analysis of patients admitting to drug use, the male predominance of other risk behaviors was not observed; the only significant differences between genders were a higher rate of prostitution among women and a higher rate of sexual contact with a prostitute among men. CONCLUSIONS: In patients visiting an inner-city emergency department in the Bronx, HIV risk behaviors are generally more common in men, but rates of risk behaviors among male and female drug users are comparable.

Adult↗

PubMed1999

Evaluating supervised HAART in late-stage HIV among drug users: a preliminary report.

OBJECTIVE: To examine response to highly active antiretroviral therapy (HAART) among a sample of treatment-experienced patients in the late stage of human immunodeficiency virus (HIV) infection in residential health care facilities (RHCFs) in New York City facilities designated for HIV/AIDS (acquired immunodeficiency syndrome) when access and adherence are maximized. METHODS: Medical record review of 111 patients. RESULTS: Demographics were mean age 42 years; 58% male; 60% African-American; 31% Hispanic; 57% injection drug users (IDUs); 23% with history of dementia; 52% hepatitis C virus (HCV) antibody seropositive; 80% on HAART, of whom 18% had lipodystrophy. Of 88 patients on HAART, 52% had a decreased viral load (>1/2 log) versus 13% of 23 not on HAART (P<.05); a >1/2 log viral load increase was seen in 8% and 35%, respectively (P<.05). Those with viral load increase were more likely than those with stable/decreased viral load to be IDUs (71% vs. 64%) and to have HCV seropositivity (86% vs. 53%), even with similar initial CD4+ cell count, viral load, and follow-up time. CONCLUSION: In a predominantly minority IDU population who are treatment experienced, 50% of the patients successfully responded to treatment with supervised therapy. The RHCFs in New York City provide a unique opportunity to examine further factors associated with response to HAART in an environment in which medication administration and adherence are maximized and monitored carefully.

Adult↗

PubMed1999

Is hospitalization necessary for treatment of SVT? Predictive variables for recurrence and negative outcome.

In this article we attempt to identify variables that may predict which pediatric patients presenting with supraventricular tachycardia to the emergency department are at risk for immediate recurrence or negative outcome. We studied an 11-year chart review and follow-up of pediatric patients presenting to the pediatric ED with a diagnosis of SVT. Recurrences of SVT during the first 24 hours after initial episode and occurrences of negative outcome (ie, respiratory distress, cardiac arrest) during hospital stay were measured. 51 patients met our inclusion criteria: 74.5% were treated as inpatients. 18% experienced a recurrence during 24 hours; 3 patients were less than 3 months of age. Recurrence within 90 minutes of conversion occurred in 4/7 patients. All negative outcomes (3.9%) occurred in the less than 3-month age group. Patients less than 3 months or with immediate supraventricular tachycardia recurrence may have a higher probability of recurrence and negative outcome and therefore may require hospitalization.

Adolescent↗

PubMed1999

Residential detoxification for substance abusers with HIV/AIDS. Walden House Detoxification Program.

Substance abusers with HIV/AIDS have a complex array of problems that are not easily addressed in outpatient or long-term residential programs. A new but promising treatment modality is residential detoxification for substance abusers with HIV/AIDS, such as described by this paper. The purpose of the program is profiled, as well as its general components and the aspects that address the special needs of HIV clients. Data indicating the successes and limitations of the program are presented, along with recommendations for further addressing the needs of substance abuses with HIV/AIDS.

Acquired Immunodeficiency Syndrome↗

PubMed1999

Perceptions of pediatric emergency medicine fellows and program directors about research education.

UNLABELLED: Pediatric emergency medicine (PEM) fellows who entered training after January 1995 are required to complete three years of fellowship training. Additionally, they are required to receive instruction in related basic sciences and to demonstrate research competence. OBJECTIVES: To determine: 1) whether PEM fellows and program directors perceive their programs as providing adequate training in research principles, 2) the manner in which these principles are taught, and 3) the commitment of fellows and program directors to research and research training. METHODS: Pediatric emergency medicine fellows who participated in the Fourth Annual PEM Fellows Conference (Miami, Florida, March 1997) were surveyed. The survey was then extended via mail to all PEM fellows and program directors in the United States and Canada. RESULTS: A total of 159 of the 220 fellows (72%) in the United States and Canada returned completed questionnaires. Fifty-three of 70 PEM fellows (76%) who attended the conference completed questionnaires, and 106 of 167 fellows (63%) who did not attend the conference responded by mail. Fifty-three of the 63 program directors (84%) returned completed questionnaires. Of 159 responding fellows, 86 (54%), and of 53 responding program directors, 29 (58%) reported that their programs lacked adequate training in one or more of the surveyed research areas. Thirteen program directors (25%) reported no formal research training in their curricula. Programs that included formal research training were perceived to have higher overall quality than programs that failed to offer such formal training. Sixty-six of 158 responding fellows (42%) anticipated an ongoing commitment to research in their careers. One hundred fourteen of 153 responding fellows (75%) indicated that, if given the option, they would have pursued a two-year "clinical track" PEM board certification that did not include a research requirement. CONCLUSIONS: More than half of surveyed PEM fellows and program directors perceived important deficiencies in research education within their training programs. Further research is necessary in order to evaluate the validity of these perceptions.

Attitude of Health Personnel↗

PubMed1999

Systemic lupus erythematosus. Measures to keep this unpredictable disease under control.

SLE is a chronic autoimmune disease with an unpredictable history and course. It can occur in men or women at any age, but it is most prevalent in women of childbearing age. SLE displays a variety of clinical and laboratory manifestations that vary from vague constitutional symptoms to findings of end-organ dysfunction. Early recognition can lead to better treatment and preventive care, thereby avoiding the more aggressive renal, cardiovascular, and septic manifestations. Recognition and management of lupus flares and of medication side effects can markedly reduce morbidity and mortality, allowing patients to live more functional lives.

Age Factors↗

PubMed1998

Incubation period of HIV-1 in perinatally infected children. New York City Perinatal HIV Transmission Collaborative Study Group.

OBJECTIVES: To estimate the distribution of the incubation period of HIV-1 among perinatally infected children and to test the hypothesis that this distribution has been changing over time. DESIGN: An analysis of 190 perinatally HIV-1-infected children born between 1986 and 1997 in eight medical centers in New York City to women enrolled in a prospective cohort study. METHODS: Non-parametric Kaplan-Meier method and parametric survival analysis. RESULTS: Using the Kaplan-Meier method it was estimated that among perinatally HIV-1-infected children, 48% [95% confidence interval (CI), 41-56] developed AIDS by 3 years of age after which the rate was less than 3% per year. Using a parametric survival analysis for extrapolation, it was predicted that 33% (95% CI, 23-43) would remain AIDS-free at 13 years of age. Median age at onset of AIDS was estimated to be 4.1 years (95% CI, 1.9-6.4) by parametric survival analysis. The year of birth was significantly associated with AIDS-free survival, suggesting an increase in the time to AIDS over the years. This association remained significant (P=0.03) after adjustment for those maternal characteristics that have also changed over time: timing of enrollment (prepartum versus postpartum), zidovudine, alcohol, and hard drug (heroin, cocaine or methadone) use during pregnancy. CONCLUSIONS: Although a substantial proportion of perinatally HIV-1-infected children develop AIDS very early in life, a significant and increasing percentage of them are expected to survive into adolescence without developing AIDS. Further research is needed to determine the factors associated with the lengthening survival to AIDS.

Adolescent↗

PubMed1998

Familial ureteral abnormalities syndrome: genomic mapping, clinical findings.

Abnormal development of the ureter during embryogenesis, when occurring in multiple family members, appears to be a genetically determined defect with autosomal dominant inheritance and high penetrance, which can lead to significant kidney damage, renal failure, and death. We have studied 48 individuals within a large kindred in which ureteral-related abnormalities (including vesicoureteral reflux, ureteropelvic junction obstruction, duplicated ureters, and medullary sponge kidney) were segregated. Family members who had not had previous diagnostic studies were evaluated for presence or absence of ureteral abnormalities and we attempted to map the locus for this familial ureteral abnormalities syndrome (FUAS). These studies identified 11 asymptomatic individuals, previously assumed to be unaffected, with minor abnormalities. When linkage analysis between the inheritance of ureteral abnormalities and six marker loci glyoxalase I (GLO- ), major histocompatibility antigens (HLA-A, B, and DR/DQ), D6S288, and factor XIII antigen (F13A1) on the short arm of chromosome 6 was performed, the lod scores significantly rejected linkage over a 77.1-cM distance. These findings are in contrast to previous data suggesting linkage between the presence of ureteral abnormalities and HLA, and indicate the possibility of genetic heterogeneity of FUAS.

Chromosome Mapping↗

PubMed1998

Identification and mapping of keratinocyte muscarinic acetylcholine receptor subtypes in human epidermis.

Acetylcholine mediates cell-to-cell communications in the skin. Human epidermal keratinocytes respond to acetylcholine via two classes of cell-surface receptors, the nicotinic and the muscarinic cholinergic receptors. High affinity muscarinic acetylcholine receptors (mAChR) have been found on keratinocyte cell surfaces at high density. These receptors mediate effects of muscarinic drugs on keratinocyte viability, proliferation, adhesion, lateral migration, and differentiation. In this study, we investigated the molecular structure of keratinocyte mAChR and their location in human epidermis. Polymerase chain reaction amplification of cDNA sequences uniquely present within the third cytoplasmic loop of each subtype demonstrated the expression of the m1, m3, m4, and m5 mAChR subtypes. To visualize these mAChR, we raised rabbit anti-sera to synthetic peptide analogs of the carboxyl terminal regions of each subtype. The antibodies selectively bound to keratinocyte mAChR subtypes in immunoblotting membranes and epidermis, both of which could be abolished by preincubating the anti-serum with the peptide used for immunization. The immunofluorescent staining patterns produced by each antibody in the epidermis suggested that the profile of keratinocyte mAChR changes during epidermal turnover. The semiquantitative analysis of fluorescence revealed that basal cells predominantly expressed m3, prickle cells had equally high levels of m4 and m5, and granular cells mostly possessed m1. Thus, the results of this study demonstrate for the first time the presence of m1, m3, m4, and m5 mAChR in epidermal keratinocytes. Because keratinocytes express a unique combination of mAChR subtypes at each stage of their development in the epidermis, each receptor may regulate a specific cell function. Hence, a single cytotransmitter, acetylcholine, and muscarinic drugs may exert different biologic effects on keratinocytes at different stages of their maturation.

Antibody Specificity↗

PubMed1998

Forensic use of Megaselia abdita and M. scalaris (Phoridae: Diptera): case studies, development rates, and egg structure.

Megaselia abdita Schmitz is reported from human corpses in 2 forensic cases in Chicago, IL. This fly has not been recorded in the Nearctic region before these occurrences. Descriptions of the death scenes and the insect indicators are given, as are developmental schedules and descriptions of the eggs of M. abdita and Megaselia scalaris (Loew). The presence of either fly on the body, together with blowflies or other insects, could contribute to a determination of the postmortem interval. Given their predilection for older carrion, these flies would be relegated to a secondary forensic role. Phoridae have been shown to be primary flies in Okinawa and Panama, and they may occur elsewhere as the only insect evidence, especially in sealed apartments inaccessible to large insects.

Adult↗

PubMed1998

Brain serotonin neurotransmission: an overview and update with an emphasis on serotonin subsystem heterogeneity, multiple receptors, interactions with other neurotransmitter systems, and consequent implications for understanding the actions of serotonergic drugs.

Knowledge about serotonergic neurotransmission has been expanding rapidly. Recent research has delineated 15 molecularly different serotonin receptors and multiple, discrete neuronal and nonneuronal (including endocrine) pathways and mechanisms that mediate the many functions of serotonin. Nonetheless, gaps remain regarding aspects of the anatomy and physiology of serotonin in its roles as a neurotransmitter, a neuromodulator, and a hormone. Few serotonin receptor-selective drugs are available for clinical use. A group of selective serotonin reuptake inhibitors (SSRIs) remain the agents with greatest therapeutic utility, although the mechanisms underlying their delayed efficacy, which clearly result from adaptive consequences following repeated administration rather than early uptake inhibition of serotonin by itself, are incompletely understood and appear to involve changes in signal transduction and gene expression in serotonergic and other neurotransmitter systems.

Animals↗

PubMed1997

Analysis of a Streptococcus pneumoniae gene encoding signal peptidase I and overproduction of the enzyme.

The spi gene of Streptococcus pneumoniae was cloned and its nucleotide sequence was determined. It encodes a protein of 204 amino acids that is homologous to bacterial signal peptidase I proteins. The S. pneumoniae protein contains all of the conserved amino acid sequence motifs previously identified in this enzyme from both prokaryotic and eukaryotic sources. Sequence comparisons revealed several additional motifs characteristic of the enzyme. The cloned S. pneumoniae gene complemented an Escherichia coli mutant defective in its leader peptidase gene. Expression of the spi gene in S. pneumoniae appeared to be essential for viability. The cloned gene was shown to produce a polypeptide of approximately 20 kDa. Overproduction of the S. pneumoniae spi gene in an E. coli expression system gave a native protein product, soluble in the presence of a non-ionic detergent, which should be amenable to structural determination.

Amino Acid Sequence↗

PubMed1997

Timing of maternal-infant HIV transmission: associations between intrapartum factors and early polymerase chain reaction results. New York City Perinatal HIV Transmission Collaborative Study Group.

OBJECTIVE: To investigate the hypothesis that labour and delivery events, perinatal characteristics, and maternal factors are only associated with intrapartum HIV transmission, and not with intrauterine HIV transmission. METHODS: In the New York City Perinatal HIV Transmission Collaborative Study 276 infants of HIV-infected women were followed prospectively and had results of early polymerase chain reaction (PCR) tests available. Among infected children, intrauterine infection was presumed if HIV DNA was detected by PCR in samples collected from children aged < or = 3 days, and intrapartum infection was presumed if HIV DNA was not detected in these early samples. The proportion of infants with presumed intrauterine and intrapartum infections were compared by selected intrapartum, perinatal and maternal characteristics. RESULTS: Presumed intrapartum infection was found in 7% of infants delivered by Cesarean section and, among infants delivered vaginally, those with longer duration of membrane rupture (> 4 h) were significantly more likely to have presumed intrapartum HIV infection (22%) than those with shorter duration (9%; P = 0.02). There were no differences in presumed intrauterine HIV infection by mode of delivery or longer duration of membrane rupture. Infants born preterm and small for gestational age had significantly higher risks of presumed intrapartum infection, but only those who were small for gestational age had higher risks of intrauterine infection. CONCLUSION: Our results support the notion that selected intrapartum conditions, long duration of membrane rupture prior to delivery in particular, are independent risk factors for maternal-infant transmission, and suggest that preterm infants may be especially vulnerable to intrapartum HIV exposure.

Birth Weight↗

PubMed1997

Reactivity-based coronary vasospasm independent of atherosclerosis in rhesus monkeys.

OBJECTIVES: We studied the hypothesis that in the absence of vascular pathology, coronary artery vasospasm occurs as a result of local regions of vascular muscle hyperreactivity. We aimed to explore the basis for a functional etiology of those vasospasms not explained on a structural basis. BACKGROUND: Ovariectomized rhesus monkeys (Macaca mulatta) without injury or significant vascular disease were stimulated with platelet release products, and angiograms were compared with those from vasospasms induced in human patients. METHODS: We used intracoronary (IC) injections of serotonin, thromboxane A2 (U46619), endothelin 1 or angiotensin II in concentrations 3 to 10 times that which reduced coronary artery diameter by 50%. RESULTS: Although no agent alone caused vasospasm, the combination of pathophysiologic concentrations of serotonin and the stable thromboxane A2 mimetic, U46619, injected through an IC catheter, synergistically caused coronary vasospasm on the second or third challenge in five of seven monkeys. These drug-induced vasospasms were similar to vasospasms induced by mechanical injury followed by serotonin, and to those stimulated in human IC diagnostic tests, as judged by onset, appearance, kinetics and vasodilator reversal. CONCLUSIONS: These studies in ovariectomized monkeys revealed that coronary vasospasm can be stimulated without preexisting vascular pathology, endothelial denudation or injury. Reproducible vasospasm of primate coronary arteries in response to these two endogenous pathophysiologic vasoconstrictors, which are thought to be precipitating stimuli in the etiology of vasospasm, suggests that structure-independent epicardial vasospasm can be an important element in serious cardiac ischemic events, particularly the focal, persistent vasospasms that occur without plaques or injury.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

PubMed1997

Rates of and factors associated with self-reported prior HIV testing among adult medical patients in an inner city emergency department in the Bronx, New York City.

We studied the rates of and factors associated with self-reported prior human immunodeficiency virus (HIV) testing in adult patients visiting an emergency department (ED) in the Bronx, New York City. A total of 1,744 consecutive noncritical adult medical emergency patients responded to a standardized interview administered by ED physicians. The interview included questions pertaining to demographic characteristics, prior HIV testing, and HIV risk behaviors. On multivariate analysis, female gender, younger age, history of weight loss, injecting drug use (IDU), syphilis, and genital herpes were all associated with increased reported prior testing rates. Race (i.e., black race) was an independent predictor of increased rates among male subjects; comparatively low rates were reported by patients with a first language other than English, patients lacking medical insurance, and highly sexually active, nonblack men. Increased HIV testing rates were reported by subjects with recognized HIV risk behaviors in a New York City ED population; however, substantial proportions of subjects at risk had not been tested. Programs of HIV testing and counseling need to include older, uninsured, and non-English-speaking segments of the population who engage in high-risk behaviors.

Adolescent↗

PubMed1997

Effect of maternal CD4+ cell count, acquired immunodeficiency syndrome, and viral load on disease progression in infants with perinatally acquired human immunodeficiency virus type 1 infection. New York City Perinatal HIV Transmission Collaborative Study Group.

Among a cohort of 152 infants perinatally infected with human immunodeficiency virus type 1, and their mothers, we correlated infant outcome with material CD4+ lymphocyte count and the presence of maternal acquired immunodeficiency syndrome near delivery. In a subset of 50 mother-infant pairs, we also correlated infant outcome with maternal quantitative viral burden as measured by the nucleic acid sequence based amplification system. We found that low maternal CD4+ cell count and high viral burden were associated with decreased time to category C disease or death in infants infected with human immunodeficiency virus type 1. In a multivariate analysis, high maternal viral load and maternal acquired immunodeficiency syndrome were independently associated with shorter time to category C disease or death in infants with human immunodeficiency virus type 1 infection. High viral load in pregnant women, independent of the presence of advanced maternal disease, appears to increase the risk of rapidly progressive disease in their infected offspring.

Acquired Immunodeficiency Syndrome↗

PubMed1997

A prospective study of tuberculosis and human immunodeficiency virus infection: clinical manifestations and factors associated with survival.

We prospectively studied the effect of human immunodeficiency virus (HIV) infection on the presentation and outcome of tuberculosis. A total of 216 patients with tuberculosis were identified; 162 (75%) of these patients were tested for antibodies to HIV; 92 (57%) were seropositive. The patients who were seropositive for HIV were more likely to be male and Hispanic and to have been homeless or incarcerated. Eighty-one percent of these patients had CD4 lymphocyte counts of < or =200/mm3. The seropositive patients had extrapulmonary tuberculosis more often than did the seronegative patients (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.2-4.8). Smears for acid-fast bacilli were positive more often for non-HIV-infected patients with pulmonary tuberculosis (74.5%) than for HIV-infected patients (54.3%) [OR, 2.46; 95% CI, 1.01-6.02]-even those with focal or cavitary disease. A delay in initiating therapy was associated with in-hospital mortality: the median time from admission to the start of treatment was 4 days for patients who survived and 15 days for those who died (P = .02). The median survival was 22.7 months for HIV-infected patients who did not die during the initial hospitalization. Factors independently associated with reduced rates of survival included the severity of immunodeficiency, nonuse of directly observed therapy, infection due to drug-resistant Mycobacterium tuberculosis, and a history of injection drug use.

AIDS-Related Opportunistic Infections↗