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Biomedical subjects

A Berkman

Publications and source records attributed to A Berkman.

12 recordsLinked to original sources
PubMed2001

Suboptimality in human categorization and identification.

Categorization and identification decision processes were examined and compared in 4 separate experiments. In all tasks, the critical stimulus component was a line that varied across trials in length and orientation, and the optimal decision rules were always complex piecewise quadratic functions. Evidence was found that identification is mediated by separate explicit and implicit systems. In addition, a common type of suboptimality was found in both categorization and identification. In particular, observers apparently approximated the piecewise quadratic functions of the optimal decision rules with simpler piecewise linear functions. A computational model, which was motivated by a recent neuropsychological theory of category learning, successfully accounted for this suboptimal performance in both categorization and identification. The model assigns a key role to the striatum and assumes the observed suboptimality was largely due to massive convergence of visual cortical cells onto single striatal units.

California↗
PubMed2000

Essential medical facts for mental health practitioners.

New information about the life cycle of HIV, new HIV-specific laboratory tests, and newer antiretroviral medications have transformed the management of HIV illness. Knowledge about these changes will help mental health providers better understand the latest medical issues affecting their HIV-infected patients, which will assist them in providing better care.

Acquired Immunodeficiency Syndrome↗
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↗
PubMed1998

Human immunodeficiency virus sexual risk reduction in homeless men with mental illness.

BACKGROUND: The spread of human immunodeficiency virus infection to impaired groups has intensified the challenge for its prevention; control of the epidemic now requires behavioral change among persons with limited ability to sustain attention and learn. In this randomized clinical trial, we tested an intervention to reduce sexual risk behaviors among homeless men with severe mental illness. METHODS: Men were recruited from a psychiatric program in a homeless shelter. Of 116 eligible men, 97 (83.6%) participated. Most were African American and had a chronic psychotic disorder and a comorbid substance use disorder. Participants were assigned to a 15-session experimental group intervention or to a 2-session control intervention and observed for 18 months. The 59 participants sexually active before the trial were the main target of the intervention. Sexual risk behavior was the primary outcome. RESULTS: Among the 59 sexually active men, follow-up data were obtained on 59 (100%) for the initial 6-month follow-up and on 56 (95%) for the remainder of the 18-month follow-up. The mean score on a sexual risk index for the experimental group was 3 times lower than for the control group (1.0 vs 3.1; P=.01) during the initial 6-month follow-up and 2 times lower during the remainder of the 18-month follow-up. CONCLUSIONS: This intervention successfully reduced sexual risk behaviors of homeless men with mental illness. The effect diminished over 18 months but did not disappear. Similar approaches may be effective in other impaired high-risk groups.

Behavior Therapy↗
PubMed1997

HIV infection among young adults with psychotic disorders.

OBJECTIVE: The authors examined HIV infection among young adults with newly diagnosed psychotic disorders. METHODS: The study was based on a research cohort of 320 first-admission patients aged 20-39 years in a semirural-suburban county. Research assessments and medical records were systematically reviewed for information about HIV status. RESULTS: Despite the fact that few patients were tested for HIV, 12 (3.8%) of the 320 patients had a known HIV infection. In all 12 cases, the HIV infection was contracted before the onset of psychosis. AIDS was the leading cause of mortality in the 320 patients. CONCLUSIONS: The HIV epidemic may be having an important effect on the etiology and the course of psychotic disorders.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Methods for successful follow-up of elusive urban populations: an ethnographic approach with homeless men.

Public health is paying increasing attention to elusive urban populations such as the homeless, street drug users, and illegal immigrants. Yet, valid data on the health of these populations remain scarce; longitudinal research, in particular, has been hampered by poor follow-up rates. This paper reports on the follow-up methods used in two randomized clinical trials among one such population, namely, homeless men with mental illness. Each of the two trials achieved virtually complete follow-up over 18 months. The authors describe the ethnographic approach to follow-up used in these trials and elaborate its application to four components of the follow-up: training interviewers, tracking participants, administering the research office, and conducting assessments. The ethnographic follow-up method is adaptable to other studies and other settings, and may provide a replicable model for achieving high follow-up rates in urban epidemiologic studies.

Anthropology, Cultural↗
PubMed1989

Binding specificity and presynaptic action of anaphylatoxin C5a in rat brain.

Human anaphylatoxin C5a injected directly to the perifornical hypothalamus (PFH) of the rat elicits food intake in sated rats, an effect which mimics that of norepinephrine (NE) at the PFH. The ability of C5a to induce food intake is selectively blocked by the alpha-adrenergic antagonist phentolamine, confirming that C5a exerts its effects via an alpha-adrenergic receptor system. In this study specific C5a binding sites on rat brain slices were detected using 125I-C5a at 2.4 nM in the presence of unlabeled noncompeting C3a and competing C5a at 0.5 microM. To determine whether the in vivo activity of C5a was due to direct stimulation of an alpha-adrenergic receptor system or to indirect modulation via a specific C5a receptor, rats were pretreated at the PFH with C5ai, the "inactive" 74-desarginated derivative of C5a. C5ai blocked stimulation of feeding by C5a but had no effect on food intake elicited by NE, suggesting a presynaptic site for C5a activity. To determine whether C5a anaphylatoxin acts at presynaptic or postsynaptic sites, the ability of C5a and of NE to induce food intake in sated rats was compared before and after injection of the tyrosine hydroxylase inhibitor alpha-methyl-p-tyrosine (AMPT) to the PFH. AMPT would produce focal depletion of endogenous catecholamines by inhibition of catecholamine biosynthesis. Rats treated with AMPT failed to respond to C5a but ate excessively following NE, suggesting that C5a acts presynaptically, possibly to release NE. We propose that C5a acts at a specific C5a/C5ai receptor to modulate catecholamine activity at the brain site.

Anaphylatoxins↗
PubMed1989

Mortality versus improvement in severe chronic asthma: physiologic and psychologic factors.

Improved outcome (1 to 10 years) of 140 asthmatic children retrospectively correlated with 8 of 49 variables in admission evaluation: (1) age of onset, (2) IgE, (3) night/early AM bronchospasm, (4) aggression, (5) severely disrupted family circumstances, (6) severe psychopathology, (7) psychotic signs, and (8) I.Q. Patients with fatal outcome (6% to 12%) deviated in the last three variables; most were 12.1 to 16.5 years, male, Black/Hispanic, aggressive, depressed and/or anxious. Clinical implications include high-risk identification on the basis of psychologic and physiologic variables, preventative measures, and consideration of residential treatment.

Adaptation, Psychological↗
PubMedDate not supplied

Fine needle aspiration diagnosis of benign metastasizing leiomyoma of the lung. A case report.

Percutaneous fine needle aspiration biopsy was performed on a woman with multiple bilateral lung nodules. The cytology and histology showed a benign spindle cell tumor compatible with benign metastasizing leiomyoma. The patient had a history of hysterectomy 14 years earlier for a cellular leiomyoma with atypia. No significant mitosis was present in either the uterine tumor or lung metastasis.

Adult↗