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Biomedical subjects

A M Marcus

Publications and source records attributed to A M Marcus.

15 recordsLinked to original sources
PubMed1996

Characterization of c-myc-transformed rat fibroblasts resistant to apoptosis induced ny growth factor deprivation.

Under appropriate conditions (e.g., growth factor withdrawal), the deregulated expression of c-myc in rodent fibroblasts leads to substantial cell death due to apoptosis. To better understand this process, we selected for c-myc-transformed Rat1A fibroblasts that were resistant to growth factor deprivation-induced cell death. One clonal isolate exhibited prolonged survival in serum-free medium and displayed reduced levels of apoptosis-related DNA fragmentation. These cells were also resistant to induction of apoptosis by the protein kinase inhibitor staurosporine. They retained a transformed cell phenotype and expressed the proviral human c-myc allele in an unaltered fashion, strongly indicating that the mutation of a cellular gene other than c-myc accounts for the apoptosis-resistant phenotype. The results of somatic cell hybrid analysis of this cell line are consistent with a recessive mutation. Our findings suggest a novel mechanism for abrogation of apoptosis in neoplastic cells and provide a model system for the study of its role in tumorigenesis and resistance to antineoplastic therapy.

Alkaloids↗
PubMed1996

Maintenance of telomeres in SV40-transformed pre-immortal and immortal human fibroblasts.

Shortening of telomeres has been hypothesized to contribute to cellular senescence and may play a role in carcinogenesis of human cells. Furthermore, activation of telomerase has frequently been demonstrated in tumor-derived and in vitro immortalized cells. In this study, we have assessed these phenomena during the life span of simian virus 40 (SV40)-transformed preimmortal and immortal human fibroblasts. We observed progressive reduction in telomere length in preimmortal transformed cells with extended proliferative capacity, with the most dramatic shortening at late passage. Telomere lengths became stabilized (or increased) in immortal fibroblasts accompanied, in one case, by the activation of telomerase. However, an independent immortal cell line that displayed stable telomeres did not have detectable telomerase activity. Furthermore, we found significant telomerase activity in two preimmortal derivatives. Our results provide further evidence for maintenance of telomeres in immortalized human fibroblasts, but they suggest a lack of causal relationship between telomerase activation and immortalization.

Base Sequence↗
PubMed1988

Psychiatric morbidity associated with early clinical diagnosis of Huntington disease in a predictive testing program.

Predictive testing for Huntington disease is now possible by using DNA markers close to the mutant gene. Such tests result in an increased or decreased risk estimate as to whether the person tested has inherited the mutant gene. Persons who already manifest subtle signs of the disease but see themselves as presymptomatic will also present to the preclinical testing programs. The authors report a severe psychiatric reaction to a positive clinical diagnosis of Huntington disease in a woman enrolled in a pilot preclinical program who had a history of psychiatric illness and hospitalizations. She is the only one of 60 persons currently enrolled in the program who has had a serious crisis. The authors demonstrate the need for readily available and ongoing counseling services for all persons participating in such a program.

Adjustment Disorders↗
PubMed1987

Perception of maternal behavior by elementary school children of alcoholic mothers.

Elementary-school-aged children of alcoholic mothers more often perceive their mothers to be using guilt as a means of psychological control and using lax disciplinary methods than similar children with nonalcoholic mothers. This outcome is discussed as a unique profile resulting from denial in the alcoholic family and the possible projection of guilt felt by the alcoholic mother. Implications for prevention programming and further areas for empirical investigation are suggested.

Alcoholism↗
PubMed1986

Academic achievement in elementary school children of alcoholic mothers.

Elementary school aged children (N = 40) of alcoholic mothers when compared to similar children (N = 40) with nonalcoholic mothers scored significantly lower on several subtests of an academic achievement test. This result replicated and extended previous findings to a middle-class, well-educated population. Suggestions are made for future examination of critical antecedent causes and covariates within the context of both environmental and cognitive domains.

Achievement↗
PubMedDate not supplied

BCG vaccination to prevent tuberculosis in health care workers: a decision analysis.

OBJECTIVE: To perform a decision analysis to determine the optimal strategy to prevent tuberculosis (TB) in health care workers with negative tuberculin skin tests. METHODS: We used a Markov model to study the occurrence of events each year and compared BCG vaccination to annual tuberculin testing plus isoniazid (INH) preventive therapy for those who become skin test positive. The outcome measures studied were the number of cases and deaths from TB and BCG and/or INH adverse reactions over 10 years. RESULTS: Annual tuberculin testing decreases the number of TB cases by 9% and BCG vaccination decreases the number by 49%, relative to no prevention intervention. BCG vaccination results in fewer deaths than annual tuberculin testing if the workplace incidence of Mycobacterium tuberculosis infection is greater than 0.06%, BCG vaccination effectiveness exceeds 3%, or the rate of fatal BCG adverse reactions is less than 15 times the rate reported in the literature. CONCLUSIONS: BCG vaccination results in less morbidity and mortality than annual tuberculin skin testing for health care workers in workplaces with documented TB transmission despite comprehensive infection control policies and procedures. Current policy on the prevention of TB among health care workers should be reconsidered.

Antitubercular Agents↗