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Biomedical subjects

B Frank

Publications and source records attributed to B Frank.

At least 109 records · Page 6Linked to original sources
PubMed1978

Ultrastructural characterization of nuage in spermatocytes of the rat testis.

At least six different types of nuage, as judged by morphological appearance, were found in spermatocytes of the adult rat testis. These were characterized by form, distribution, and association with other organelles. The appearance (with time) and the dissociation of some nuage types were recorded in conjunction with other events of the spermatogenic cycle. The data indicate that all types of nuage behave in a dynamic way. Especially interesting were the findings concerning the chromatoid body. This structure was first observed in mid-pachytene spermatocytes. By late diplotene and during the first meiotic division, it had lost its prominence such that its eventual fate could not be determined. Large dense (0.5 micrometer) bodies appeared de novo in the cytoplasm of newly formed secondary spermatocytes. They were seen scattered throughout the cell and in association with mitochondria. With time these bodies appeared to coalesce to form the large definitive chromatoid of a type similar to that known to be present throughout most of the remainder of spermiogenesis.

Animals↗
PubMed1978

Seeking truth in heroin indicators: the case of New York City.

An epidemiological investigation of New York City's indirect indicators of heroin activity from 1970 through 1976 yielded insights about New York City heroin trends. Indirect indicators were gathered from official data sources, such as law enforcement, health, and treatment agencies. Since each indicator had significant limitations inhibiting interpretation, a factor analysis of the indicators was performed, resulting in the reduction of a large number of variables to a small number of factors. The factor analysis demonstrated the way in which New York City indicators cluster or move together--a "street" component, including arrests, hepatitis, price and purity of retail heroin; a "new admissions to methadone treatment" component; and a "readmissions to methadone treatment" component. Furthermore, the analysis revealed the time-lag relationships between components--"new admissions to methadone treatment" lag 1--2 years behind the "street" component; "readmissions to methadone treatment" lag 1--3 years behind the "new admissions" component. Finally, the 1970--1976 factor scores were related to 1970--1974 estimates of narcotic addicts in New York City in regression analysis, and were also projected through 1978, yielding estimates of New York City's heroin addict population from 1975 through 1978.

Crime↗
PubMed1978

Characterization of rat spermatocytes after plastic embedding.

Rat testicular tissue, perfused with glutaraldehyde, post-fixed with osmium and stained with toluidine blue, was studied to obtain information which could be used to characterize spermatocytes (also type B gonia and Step 1 spermatids) with the light microscope. Measurements of relative cell, nuclear sizes and absolute nuclear size are presented in graphic form, demonstrating the progressive growth found for spermatocytes. Early prophase spermatocytes (preleptotene, leptotene, zygotene) gradually increased in size. Pachytene cells showed no growth until Stage IV, at which point a dramatic size increase began and continued until the diplotene phase. Guidelines to identify a particular phase of meiosis were established for spermatocytes using primarily nuclear traits. Examination of longitudinal sections through Stages XIII, XIV and I were useful for comparing cells from Meiotic divisions (meta-, ana-, and telophases) I and II and also for differentiating secondary spermatocytes from Step 1 spermatids.

Animals↗
PubMed1970

Interanimal "memory" transfer: results from brain and liver homogenates.

Sixty mice received either shock or no shock in a shuttle box, or nonspecific stress in another apparatus. Brain and liver homogenates from these animals were then injected into 120 naive recipients, who were all tested in the shuttle box. Subjects receiving brain or liver from shocked or stressed donors had significantly higher latencies than control counterparts. These results are interpreted in terms of stress, rather than a memory transfer hypothesis.

Animals↗
PubMedDate not supplied

Lewis incompatibility.

Explore the source record for details and available documents.

Blood Group Incompatibility↗
PubMedDate not supplied

Comparison of self-report and hair analysis in detecting cocaine use in a homeless/transient sample.

Detection of current (past 30 days) drug use by analysis of hair was examined along with self-reports of current use in a 1994 treatment needs assessment survey; the sample was 179 homeless/transient adults in New York state. Results of radioimmunoassay of hair (RIAH) were used to evaluate the veracity of self-reports of current cocaine use. Only 26% of those persons whose hair tested positive for cocaine (n=115) admitted to having used cocaine in the past 30 days. Subjects eligible for treatment, as indicated by a DSM-III-R diagnosis of cocaine dependency, were nearly four times as likely to admit current cocaine use than those who were not dependent. These results are consistent with other studies of populations at high risk for substance use.

Adolescent↗
PubMedDate not supplied

An overview of heroin trends in New York City: past, present and future.

Heroin abuse has been a long-standing problem in the United States, especially in New York City, which is a major heroin trafficking center and home to the largest population of heroin addicts in the country. As a consequence, New York City is also the major center for methadone treatment. Over time, however, the heroin problem seems to have changed in terms of demographic characteristics of abusers, as well as heroin purity, its associated health consequences, modes of use, and other drug patterns. Past and present heroin-involved events for New York City are examined, with some projection about the future of the heroin problem. To identify these changes, a variety of indirect indicators of heroin abuse are analyzed. These indirect indicators include admissions to New York City heroin treatment programs, as well as heroin-involved deaths, arrests and emergency room episodes, and heroin purity levels. Additionally, a recent study of heroin abusers in New York City yielded patterns of heroin use and estimates of heroin prevalence. The salient results indicate that, over time, Hispanics have become the predominant user group, the population of abusers is an aging cohort, heroin purity levels have risen dramatically, and intranasal use has become more prominent than injecting. The findings have important consequences for prevention, treatment, and programs that target special populations.

Adult↗