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Biomedical subjects

M Aronson

Publications and source records attributed to M Aronson.

At least 37 records · Page 2Linked to original sources
PubMed1996

Left ventricular hypertrophy on electrocardiogram: prognostic implications from a 10-year cohort study of older subjects: a report from the Bronx Longitudinal Aging Study.

OBJECTIVE: The objective of this study was to report on the prevalence, incidence and prognosis of left ventricular hypertrophy (LVH) on the electrocardiogram (ECG) in a cohort of ambulatory older men and women. DESIGN: A prospective, longitudinal study of 10 years duration with ECGs obtained at baseline and on an annual basis. SETTING AND PATIENTS: A community-based cohort study consisting of 459 subjects (aged 75-85, mean age 79 years). MEASUREMENTS: Baseline and follow up ECGs were interpreted using the Minnesota Code. Prevalence and incidence of LVH and ECG were determined as well as regression of ECG LVH. Clinical event rates measured were incidence of total mortality, myocardial infarction (MI, fatal and non-fatal), cardiovascular mortality, cardiovascular disease (fatal and non-fatal), stroke (fatal and non-fatal), all-cause dementia, and multi-infarct dementia. Differences in event rates between groups (those subjects with and without LVH) were compared as tests between proportions. A Cox Proportional Hazards Regression Analysis was performed to compare the relative independent predictive values of different competing factors, including age, gender, serum cholesterol, digitalis use, body mass, index, Blessed Dementia Scale, cigarette smoking, LVH at baseline, LVH ar baseline (persisting), new LVH, new LVH (persisting), new LVH (regressed), previous MI by history of ECG, hypertension by history, and cardiomegaly by X-ray (cardiothoracic ratio > or = 50%). RESULTS: At baseline, 9.2% of subjects (n = 42) had LVH on ECG and a mortality rate of 11.7/100 persons years versus 4.9/100 persons years for subjects without baseline LVH (P < .0001), and MI rate of 7.5/100 persons years with LVH versus 2.6/100 persons years without LVH (P < .0001), and a cardiovascular mortality rate of 7.2/100 persons years without LVH versus 2.7/100 person years without LVH. Subjects who developed new LVH on ECG (n = 39) had a mortality rate of 14.4/100 person-years compared with 4.4/100 person-years for those without LVH (P < .0001), a cardiovascular mortality rate of 11.1/100 person years versus 2.0/100 person years without LVH (P < .0001), and an MI rate of 6.1/100 person years versus 2.0/100 person years without LVH (P < .01). Subjects in whom the ECG LVH pattern disappeared over time had fewer cardiovascular mortal and morbid events than those with persistent LVH. According to the regression analyses, persistent LVH from baseline was an independent predictor of MI, overall cardiovascular disease, and total mortality. Newly developing LVH with subsequent regression was an independent predictor of overall cardiovascular disease and death. CONCLUSIONS: An increased prevalence and incidence of LVH on ECG, irrespective cause, is associated with a poor prognosis in very old men and women. Regression of ECG LVH in older people, irrespective of cause, may confer improvement in risk for cardiovascular disease.

Aged↗
PubMed1995

Significance of DNA ploidy in the treatment of T1 glottic carcinoma.

OBJECTIVE: To assess the role of DNA ploidy as a predictor of radioresistance in T1 glottic carcinoma. DESIGN: Case-control study. Flow cytometric DNA ploidy measurements were performed on formalin-fixed paraffin-embedded tumor specimens from 15 patients with T1 glottic laryngeal carcinomas in whom radiotherapy had failed and from a matched group of 15 patients in whom an identical radiotherapy regimen was curative. Analysis of DNA content was performed blind to outcome of treatment. SETTING: Academic tertiary referral medical center. PARTICIPANTS: Thirty patients with clinically staged T1, N0, M0 glottic carcinoma. INTERVENTION: All patients received radiation to the larynx through opposed lateral ports at a total dose of 64 to 70 Gy. RESULTS: Ten diploid and five aneuploid histograms were found in the resistant group, and six diploid and nine aneuploid histograms were found in the radiosensitive group. This difference was not statistically significant. A trend toward a higher relapse rate after radiotherapy (62.5%) among patients with diploid tumor compared with those with aneuploid tumor (35.7%) was noted. CONCLUSIONS: DNA ploidy did not predict response to radiotherapy in patients with T1 glottic cancer, probably because of the small number of patients. A trend toward lower risk of local recurrence after radiotherapy in aneuploid tumors was noted. A larger prospective study is needed to assess the value of DNA ploidy in the treatment of early laryngeal cancer.

Aged↗
PubMed1995

A comparative study of the desquamation of urothelial cells during gestation and in adults mice following moderate stress or endotoxin treatment.

The present paper deals with the comparative EM study of the detachment of mouse urinary bladder epithelial cells under various physiological conditions, namely, during gestation and in adult mice following induction by endotoxin or by exposure to moderate stress. It has been shown that desquamation during gestation involves two distinct modes, shedding of single cells and formation of apoptotic bodies. Moderate stress in adult female mice induced by constant illumination for 72 or 96 hours, results in desquamation of superficial and intermediate cells. Application of LPS is followed by desquamation of single cells and whole sheets of cells. Cell detachment involves interruption of tight junctions between neighbouring cells and formation of numerous cup shaped vesicles, multivesicular bodies and vacuoles at the base of desquamating cells. LPS induces desquamation entails delivery of lysosomal enzymes extracellulary into the intercellular space. In the areas of sloughing the bladder epithelium lack permeability barrier. Desquamated cells in the bladder lumen are mostly alive. These results clearly demonstrate the existence of specific adhesion mechanisms of detachment and desquamation of uroepithelial cells.

Animals↗
PubMed1995

Chromosomal mapping of the genes GPRK5 and GPRK6 encoding G protein-coupled receptor kinases GRK5 and GRK6.

G protein-coupled receptor kinases (GRKs) play an important role in phosphorylating and regulating the activity of a variety of G protein-coupled receptors. Chromosomal mapping of the human genes for the two most recently identified members of the GRK family, GRK5 (GPRK5) and GRK6 (GPRK6), was accomplished by correlation of the presence of the GPRK5 and GPRK6 loci with specific chromosome regions in a rodent-human hybrid panel. These analyses revealed that GPRK5 maps to chromosome region 10q24-->qter while GPRK6 maps to 5q35. A GPRK6 related locus maps to 13pter-->q21.

Animals↗
PubMed1994

Enhanced cytologic detection of early stage mouse bladder tumor following induction of uroepithelial cell shedding.

Previous studies from our laboratory have shown that some Escherichia coli endotoxins are capable of inducing massive normal urothelial cell shedding. In the present study we investigated whether endotoxin-induced shedding improves cytologic detection of early stage mouse bladder cancer. Mouse bladder tumor (MBT-2) cells were implanted intravesically in the submucosa of C3H female mice. Ten to 21 days later the bladders were irrigated with saline followed by instillation of endotoxin. The bladder contents of each mouse were aspirated and examined cytologically together with the bladder wash specimen. Shedding of epithelial cells was observed in only 32% of the saline irrigated specimens compared with 93% after endotoxin instillation (p < 0.00001). Analysis showed an overall accuracy rate of 39% after saline barbotage versus 78% following endotoxin administration (p < 0.00001). These results indicate that intravesical instillation of specific bacterial endotoxin significantly increases the extent of cytologic detection of early stage superficial bladder cancer.

Administration, Intravesical↗
PubMed1994

Serum vitamin B12 levels and incidence of dementia in a healthy elderly population: a report from the Bronx Longitudinal Aging Study.

OBJECTIVE: To determine whether low serum B12 levels are associated with an increased incidence of dementing illness. DESIGN: Longitudinal cohort study, 5-year follow-up. PARTICIPANTS: Volunteer cohort of 410 nondemented ambulatory subjects aged 75 to 85 years. MEASUREMENTS: Annual serum B12 determinations and neuropsychological assessments including the Blessed Test of Information, Memory and Concentration (BIMC) and the Fuld Object Memory Evaluation (FOME). If subject met criteria for a major cognitive change (as defined by an increase of 4 or more points on the BIMC), a work-up that included CT, EEG, and neurologic assessment was performed. Clinical diagnoses were made according to established criteria. RESULTS: Mean serum B12 level of entire sample was 558 pg/mL. Twenty-two subjects had low B12 levels defined as values < 150 pg/mL. Three of these 22 subjects (13.6%) became demented, compared with 57 of 388 subjects (14.7%) with higher levels. The incidence of Alzheimer disease among the low B12 group was 4.5% compared with 7.5% in the higher B12 group. The mean B12 level at time of diagnosis in subjects who did develop Alzheimer disease was 551 pg/mL. There was no evidence of hematologic disorder among the 22 subjects with low B12. Of the 3 low B12 subjects who did become demented, none responded to monthly B12 injections. CONCLUSION: A low B12 level may not be a risk factor for dementia in general or Alzheimer disease in particular.

Aged↗
PubMed1994

Moderate stress protects female mice against bacterial infection of the bladder by eliciting uroepithelial shedding.

We have previously shown (M. Aronson, O. Medalia, D. Amichay, and O. Nativ, Infect. Immun. 56:1615-1617, 1988) that shedding of viable uroepithelial cells (elicited by invading microorganisms) constitutes an antimicrobial defense mechanism. The present study deals with two different stress-involving procedures, in which increased uroepithelial shedding rendered female mice resistant to vesical infection. Moderate stress was induced in female mice by exposing the animals either to constant illumination for 96 h or to 37 degrees C heat for 24 h. In both cases, the rate of infection was considerably reduced as a result of increased epithelial shedding (P < 0.0001). Stress was manifested by both reduced thymic weight and increased blood corticosterone levels. Shedding was also elicited by intraperitoneal injection of norepinephrine together with hydrocortisone or by intravesical injection of corticosterone. Constant illumination as well as heat enormously facilitated the migration of polymorphonuclear cells into the bladder following the action of chemotactic stimuli. Male mice subjected to identical stress-generating conditions did not display considerable epithelial shedding or increased migration of polymorphonuclear cells, and they were not protected from intravesical infection.

Adrenalectomy↗
PubMed1993

Involution of the thymus revisited: immunological trade-offs as an adaptation to aging.

An attempt was made, in previous theories, to find a unifying explanation for two phenomena of thymic involution: stress-induced reversible involution and age-related irreversible involution. It was postulated that in both cases involution is beneficial to the organism, as it serves to reduce the dangers of autoimmune reactions. The modified theory proposed here: (a) relates to the suggestions of I.R. Cohen and D.B. Young (Immunol. Today, 12 (1991) 105-109) and to those of S. Avrameas Immunol. Today, 12 (1991) 154-158) as to the usefulness of autoantibodies to the organism; (b) emphasizes the fact that self components undergo continuous changes throughout the life cycle of the organism, which in turn necessitates continuous adaptations to prevent autoimmune damage; (c) stresses the relevance of these adaptations to the process of natural selection; (d) brings experimental evidence to the effect that thymic involution will reduce the danger of autoimmune damage; and (e) suggests that the adaptations required to prevent autoimmune reactions with aging entail immunological compromises or trade-offs. These measures may by themselves cause autoimmune diseases, result in reduced resistance to neoplasia and to infectious diseases, particularly viral ones, and in accelerated aging.

Adaptation, Physiological↗
PubMed1993

Magnetic resonance abnormalities in HIV infection: a study in the drug-user risk group.

Cognitive impairment is a frequent complication of advanced human immunodeficiency virus-1 (HIV-1) infection. However, structural imaging of the brain has not revealed abnormalities that precede the onset of clinical abnormalities. Cranial magnetic resonance (MR) studies were performed in 28 male subjects with intravenous drug use histories; nine were HIV-1 seronegative, 11 were HIV-1 seropositive but asymptomatic, and eight were seropositive and met symptomatic criteria for acquired immune deficiency syndrome (AIDS). Cortical atrophy, but not the degree of ventricular enlargement or signal abnormalities, was increased in the seropositive group compared with the seronegative group and also differed between asymptomatic seropositive and seronegative patients. An increased level of cortical atrophy may reflect the early impact of HIV-1 infection on the brain.

AIDS Dementia Complex↗
PubMed1993

Does excessive television viewing contribute to the development of dementia?

The etiology of most kinds of dementia is still obscure and is probably multifactorial. We query whether excessive watching of television may contribute to the development of dementive processes for the following reasons: TV spectators are exposed to a mass of successive and rapid stimuli with little or no possibility of relating to the viewing matter. In addition, a considerable part of the material is stressogenic, and generally there is no opportunity for a subsequent release of tension. Stress, via the glucocorticosteroids which it induces, has been shown to damage neurons in the hippocampus, a brain region involved in memory processes. Considering that many individuals have by now been watching television for several decades, not infrequently at an average rate of 4 or more hours daily, it is possible that cumulative, stress-derived damage may magnify the risk of a dementive process in such long-term, habitual viewers. Upon clinical intake of cases of suspected dementia, it is suggested that inquiry into the patient's television watching habits be incorporated into the anamnesis.

Aged↗
PubMed1992

Case report 705. Osteosclerotic sarcoidosis.

In summary, Sarcoidosis is a rare but well-recognized cause of diffuse osteosclerosis. The differential diagnosis of osteosclerosis is limited and includes osteoblastic metastases, sclerotic myeloma, myelofibrosis, and less common infiltrative bone marrow processes such as mastocytosis and sarcoidosis. In all of these entities the sclerosis is found most often in the axial (red marrow) skeleton. In this regard, it is interesting that cases of osseous sarcoid are usually lytic and located in the peripheral skeleton. In patients with osteosclerotic sarcoidosis, the diagnosis may be suggested by a past history of the disease or ancillary signs such as hilar node enlargement and subtle skin involvement. However, the specific diagnosis usually requires bone marrow biopsy with the demonstration of extensive, noncaseating granulomas.

Bone Diseases↗
PubMed1992

Cardiomegaly on chest x-ray: prognostic implications from a ten-year cohort study of elderly subjects: a report from the Bronx Longitudinal Aging Study.

This report is from a 10-year cohort study of community-dwelling elderly men and women. Mean age at the time of entry into the study was 79 years. Annual chest x-ray studies were performed, and data are presented regarding prevalence, incidence, and prognosis of cardiomegaly. Cardiomegaly was defined as a transverse diameter of the cardiac silhouette greater than or equal to 50% of the transverse diameter of the chest (increased cardiothoracic ratio). At the time of entry into the study 110 subjects (23%) had cardiomegaly. After 10 years, 51% of the subjects with cardiomegaly at baseline died compared with 33% of the subjects without cardiomegaly (mortality rate = 9.1 vs 4.8/100 person-years respectively; p = 0.014). Cardiovascular disease incidence was also higher for those with preexisting cardiomegaly at baseline (rate 9.1 vs 6.1/100 person-years; p = 0.0001). According to the Cox proportional hazards regression analysis, age, cardiomegaly, diabetes, and prior evidence of myocardial infarction were independent predictors for death in this cohort. Similarly, the best predictive variables for cardiovascular disease were age, diabetes, prior evidence of myocardial infarction, and cigarette smoking. Of the 359 subjects without cardiomegaly at baseline, 108 (30%) showed evidence of new cardiomegaly, and their risk of cardiovascular disease was 1.8 times that of subjects whose test results were negative for cardiomegaly throughout the study (p = 0.003). Thus cardiomegaly, as defined by an increased cardiothoracic ratio on x-ray films, irrespective of cause, is associated with a poor prognosis in very elderly men and women.

Aged↗
PubMed1992

The state of leukocyte adhesiveness/aggregation in the peripheral blood is more sensitive than the white blood cell count for the detection of acute mental stress.

We determined the state of the leukocyte adhesiveness/aggregation in the peripheral blood by using a simple slide test and found it to be more sensitive than the white blood cell count for the detection of acute mental stress. Included were 71 controls, 64 young athletes examined just before their exercise, 14 volunteers who were examined 10-20 min before engagement in rappelling while an additional group of 20 were examined just before the act as they were facing an abyss from the top of a cliff. The state of leukocyte adhesiveness/aggregation correlated significantly (p less than 0.0005) only with the increasing strain assumed to occur from the first to the fourth group. The state of leukocyte adhesiveness/aggregation was 3.3 x more sensitive than white blood cell count in both rappelling groups and 5 x more sensitive than white blood cell count when evaluated in those examined at the last minute. We concluded that the state of leukocyte adhesiveness/aggregation is a reliable marker of acute mental stress.

Adolescent↗
PubMed1992

Plasma lipids and lipoproteins and the incidence of cardiovascular disease in the very elderly. The Bronx Aging Study.

The Bronx Aging Study is a 10-year prospective investigation of very elderly volunteers (mean age at study entry, 79 years; range, 75-85 years) designed to assess risk factors for dementia and coronary and cerebrovascular (stroke) diseases. Entry criteria included the absence of terminal illness and dementia. All subjects (n = 350) included in this report had at least two lipid and lipoprotein determinations. Overall, more than one third of subjects showed at least a 10% change in lipid and lipoprotein levels between the initial and final measurements. Moreover, mean levels for women were consistently different than those for men, and because of this finding subjects were classified into potential-risk categories based on the changes observed by using their sex-specific lipid and lipoprotein distributions. The incidences of cardiovascular disease, dementia, and death were compared between risk groups. Proportional-hazards analysis showed that in men a consistently low high density lipoprotein cholesterol level (less than or equal to 30 mg/dl) was independently associated with the development of myocardial infarction (p = 0.006), cardiovascular disease (p = 0.002), or death (p = 0.002). For women, however, a consistently elevated low density lipoprotein cholesterol level (greater than or equal to 171 mg/dl) was associated with myocardial infarction (p = 0.032). Thus, low high density lipoprotein cholesterol remains a powerful predictor of coronary heart disease risk for men even into old age, while elevated low density lipoprotein cholesterol continues to play a role in the development of myocardial infarction in women. The findings suggest that an unfavorable lipoprotein profile increases the risk of cardiovascular morbidity and mortality even at advanced ages for both men and women.

Aged↗
PubMed1992

Neuropsychological and neurological manifestations of HIV-1 dementia in drug users.

The cognitive and motor deficits associated with human immunodeficiency virus-1 (HIV-1) infection have been studied using neurological examination and neuropsychological tests. However, drug users with HIV-1 infection generally have been excluded from such studies. Forty-four well-characterized drug users stratified by Centers for Disease Control staging were administered a standardized neurological examination and a battery of neuropsychological tests under single-blind conditions designed to minimize the acute effects of psychoactive substances. The results of the blind neurological examination were consistent with the previously ascertained clinical staging of HIV-1 infection. The pattern of neuropsychological deficits across HIV-1 states was similar to those found in cohorts of homosexual men.

AIDS Dementia Complex↗
PubMed1992

Auditory event-related potentials in HIV-1 infection: a study in the drug-user risk group.

Features of event-related potentials (ERPs) may be sensitive and clinically useful markers of central nervous system infection by the human immunodeficiency virus (HIV-1); however, this application has not been studied in the risk group of intravenous drug users. Auditory ERPs generated by an "oddball" paradigm were analyzed for 39 male drug abusers as part of a multimodal assessment. Stage of HIV-1 infection was associated with prolongations of P1, N1, and P3 components of the ERP waveform. Only patients with full acquired immunodeficiency syndrome showed statistically significant increases in waveform prolongations. Specific neuropsychological deficits were not related to waveform latency prolongations.

AIDS Dementia Complex↗