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Biomedical subjects

M R Rose

Publications and source records attributed to M R Rose.

At least 19 recordsLinked to original sources
PubMed1992

Selection on stress resistance increases longevity in Drosophila melanogaster.

Tests for the causal involvement of specific physiological mechanisms in the control of aging require evidence that these mechanisms can be used to increase longevity or reproductive lifespan. Selection for later reproduction in Drosophila has been shown to lead to increased longevity, as well as increased resistance to starvation and desiccation stresses. Selection for increased resistance to starvation and desiccation in Drosophila melanogaster is here shown to lead to increased longevity, indicating that alleles that increase stress resistance also may increase longevity. The responses of desiccation and starvation resistance to selection are partly independent of each other, indicating a multiplicity of physiological mechanisms involved in selectively postponed aging, and thus aging in general.

Animals↗
PubMed1992

Drosophila with postponed aging as a model for aging research.

Species of the genus Drosophila, commonly known as "fruitflies," are good model systems for research in aging. Drosophila are extremely well-known genetically, developmentally, and otherwise. They are also genetically analogous to mammalian species in most important respects. Previous work with Drosophila has been hampered by inbreeding depression, but more recent work using selection has created Drosophila with postponed aging that is inherited normally. Genetic transformation has also increased Drosophila life spans in some cases. Several biologic approaches have been applied to the analysis of genetically postponed aging in Drosophila: quantitative genetics, organismal physiology, and protein electrophoresis. Ultimately, these different approaches will be integrated into an overall analysis of aging in Drosophila, one that could be valuable for research with other taxa as well.

Aging↗
PubMed1991

Evolution of senescence: late survival sacrificed for reproduction.

In so far as it is associated with declining fertility and increasing mortality, senescence is directly detrimental to reproductive success. Natural selection should therefore act in the direction of postponing or eliminating senescence from the life history. The widespread occurrence of senescence is explained by observing that (i) the force of natural selection is generally weaker at late ages than at early ages, and (ii) the acquisition of greater longevity usually involves some cost. Two convergent theories are the 'antagonistic pleiotropy' theory, based in population genetics, and the 'disposable soma' theory, based in physiological ecology. The antagonistic pleiotropy theory proposes that certain alleles that are favoured because of beneficial early effects also have deleterious later effects. The disposable soma theory suggests that because of the competing demands of reproduction less effort is invested in the maintenance of somatic tissues than is necessary for indefinite survival.

Aging↗
PubMed1991

Quantitative genetics of postponed aging in Drosophila melanogaster. I. Analysis of outbred populations.

Selection has been used to create replicated outbred stocks of Drosophila melanogaster with increased longevity, increased later fecundity, and increased levels of physiological performance at later ages. The present study analyzed the quantitative transmission patterns of such stocks, employing extensive replication in numbers of stocks, individuals, and assayed characters. The populations used derived from five lines with postponed aging and five control lines, all created in 1980 from the same founding base population. The following characters were studied: early 24-hr fecundity, early ovary weight, early female starvation resistance, early male starvation resistance, female longevity and male longevity. Numerous crosses were performed to test for non-Mendelian inheritance, average dominance, maternal effects, sex-linkage and between-line heterogeneity. There was only slight evidence for any of these phenomena arising reproducibly in the characters studied. These findings suggest the value of this set of stocks for studies of the physiological basis of postponed aging.

Aging↗
PubMed1991

Quantitative genetics of postponed aging in Drosophila melanogaster. II. Analysis of selected lines.

Quantitative genetic analyses of Drosophila melanogaster stocks with postponed aging have suffered from the problem of a lack of certainty concerning patterns of allelic differentiation. The present experiments were designed to alleviate this difficulty by selecting for enhanced levels of characters known to be related to postponed aging. Selection successfully increased the degree of differentiation of postponed aging stocks with respect to starvation resistance and fecundity, but persistent additive genetic variance suggested that selection did not result in fixation of alleles. The artificially selected stocks were subjected to crosses to test for patterns of dominance and maternal effects. There was little evidence for these effects in the inheritance of the characters underlying postponed aging, even with the increased differentiation of the selected stocks.

Aging↗
PubMed1990

The relationship between a diagnosis of antisocial personality and hostility: development of an Antisocial Hostility scale.

An antisocial hostility scale was developed by correlating items of the Buss-Durkee Hostility Inventory with a diagnosis of antisocial personality (ASP) as determined by a computerized version of the DSM-III. Fifty-two male volunteers for drug-related studies at the Addiction Research Center were used for a preliminary test development sample. The scale developed thereby was related significantly to a diagnosis of antisocial personality in a cross-validation sample of 28 drug abusers. A final scale was developed by obtaining correlations between ASP and Buss-Durkee items using the subjects from both of these preliminary samples. Items that comprise the scale were predominantly behaviorally oriented hostility items covered by the Assault scale rather than affective items such as those in the Resentment scale. In a 122 cross-validation sample the scale was related significantly to a diagnosis of antisocial personality. The study confirms the generality of the criterion of overt aggression as a condition for meeting DSM-III criteria for antisocial personality.

Adult↗
PubMed1990

Excretion of iodine-123-hippuran, technetium-99m-red blood cells, and technetium-99m-macroaggregated albumin into breast milk.

The amount of radioactivity excreted in breast milk following three different nuclear medicine procedures on twelve nursing mothers has been measured. Some of this information has already been incorporated into the latest guidelines on suspension of feeding after maternal radiopharmaceutical administration. The overall radiation dose that the patients' babies would have sustained had breast feeding not been interrupted has been estimated as an effective dose equivalent. A model has been developed to describe the relationship between clearance of activity from the milk, time between expressions, and the fraction of milk expressed. Some simple guidance is given on calculation of suitable interruption times for any individual mother from counts on her milk samples.

Erythrocytes↗
PubMed1989

Mammographically detected duct carcinoma in situ. Frequency of local recurrence following tylectomy and prognostic effect of nuclear grade on local recurrence.

Seventy-nine patients with mammographically detected foci of duct carcinoma in situ (DCIS) of histologically confirmed extents of 25 mm or less, were treated by tylectomy without irradiation or axillary dissection. Adequacy of excision was confirmed histologically, by radiographic-pathologic correlation and by postoperative mammographic examination. Eight patients (10.1%) have recurred locally in the immediate vicinity of the biopsy site. Four patients developed recurrent in situ disease identified mammographically, and all were initially treated by reexcision. One of these patients subsequently elected to undergo mastectomy; no residual in situ or invasive disease was detected in the breast or in axillary lymph nodes. Four patients developed recurrent invasive disease; 50% of these recurrences were detected mammographically. All patients were treated by mastectomy with node dissection. Three had confirmed minimal invasive carcinomas and were N0, one patient had a 13-mm invasive lobular carcinoma with a single Group I micrometastasis. All patients, including those treated for a recurrence, are presently free of disease but three patients died of heart disease. Nuclear grade would appear to identify subsets of DCIS more likely to produce local failure after tylectomy alone. Duct carcinoma in situ with high-grade nuclear morphology and comedo-type necrosis was associated with a 19% local recurrence rate after an average interval of 26 months; only one of ten patients with intermediate-grade DCIS developed a local recurrence at 87 months; and none of 33 patients with DCIS of micropapillary/nonnecrotic cribriform type and low-grade nuclear morphology developed local recurrence in the follow-up period.

Breast Neoplasms↗
PubMed1989

Genetics of increased lifespan in Drosophila.

Natural selection in the laboratory has been used to produce populations of Drosophila with genetically increased lifespan. These populations have been used to determine the physiological basis of postponed ageing and its pleiotropic concomitants. It appears that many loci and a number of physiological alterations are involved in increased lifespan.

Aging↗
PubMed1989

Kids and cocaine--a treatment dilemma.

Despite aggressive efforts to recruit into treatment cocaine users 21 years and younger, we obtained only 12 such clients over a period of 9 months, while recruiting 122 adult cocaine clients during a comparable time frame. An examination of admissions data for the city, state, and nation indicated that our experience was typical. However, data from the most recent national household survey indicate that, to the extent need for treatment is determined by frequency of cocaine use, we should anticipate a much greater proportion of admissions to treatment to come from persons 21 years of age and younger. Yet, there appears to be an under-recruitment of youth into treatment, particularly evidenced by low rates of self-referral for juvenile as compared to older treatment admissions. Younger cocaine users may be less severely impaired and/or dependent, or may be more reluctant to use the treatment resources available. Whatever the barriers are to getting help, it becomes the special task of agencies and individuals in the community to help assure that younger cocaine users will obtain the assistance they need. Four community resources are seen as particularly relevant: family, schools, the medical community, and public agencies in the areas of health, social services, and criminal justice. The capacity of each to take action and possible impediments to that action are discussed.

Adolescent↗
PubMed1989

What evolutionary biology can do for gerontology.

Evolutionary biologists have shown mathematically that aging is an inevitable consequence of age-specific natural selection acting on species with somata separate from germ lines. Two specific genetic mechanisms are known which could underlie the evolution of aging under these conditions: age-specificity of gene effects and antagonistic pleiotropy between early and late ages. Comparative evidence indicates that senescence occurs only when the stipulations of the evolutionary theory are met. Laboratory experiments with Drosophila indicate that prolonging the action of natural selection leads to the evolution of postponed senescence. The genetic variation involved in such postponed senescence exhibits both age-specificity and antagonistic pleiotropy. These theories and empirical findings together suggest that the best general theory of aging now available is the evolutionary theory. In addition, this work has yielded Drosophila stocks with postponed senescence that are being used to unravel physiological mechanisms of senescence.

Aging↗
PubMed1989

Comparison of the characteristics and functioning of cocaine treatment and cocaine research subjects.

Comparisons were made of the functioning and characteristics of cocaine-abusing volunteers to a research ward (N = 25) and to an outpatient treatment program (N = 33) at the same research facility. It was hypothesized that individuals volunteering for clinical studies and for treatment-related studies would represent different segments of the cocaine-abusing population, and that those differences could be significant to an understanding of study findings. Demographic/background variables were assessed through use of the Addiction Severity Index, risk-taking behaviors relative to HIV infection and AIDS through use of a structured interview schedule, intellectual functioning through use of the Shipley Institute for Living Scale, and psychiatric symptoms through use of the Hopkins Symptom Check List (SCL-90R). Significant differences were obtained for criminal activity, needle sharing, and selected psychiatric symptoms. Marital status was particularly important to an understanding of differences between research and treatment groups in that unmarried treatment subjects showed significantly greater psychopathology than research subjects on 3 of 11 symptom scores. Unmarried treatment subjects showed significantly greater deviance than married treatment subjects on 7 of 11 symptom scores. The findings suggest a relationship between marital status and the psychological functioning of treatment clients and indicates that different segments of the cocaine-abusing population volunteer for different types of research.

Adult↗
PubMed1988

Coronary dissection following chest trauma with systemic emboli.

Coronary artery dissection is a rare entity which occurs following blunt chest trauma, during coronary angiography and coronary bypass surgery, and spontaneously in the peripartum period. We report a young man who presented with recurrent systemic emboli following an asymptomatic anterior wall myocardial infarction associated with dissection of the LAD and mural thrombus three years earlier after sustaining blunt chest trauma.

Adult↗
PubMed1986

Males, parthenogenesis, and the maintenance of anisogamous sex.

The problem of the maintenance of anisogamous sex is addressed by considering the effect of fertilization on the fitness of parthenogenetic females when such fertilization yields inviable triploid progeny. We consider four types of parthenogenesis: (i) apomixis, (ii) homogametic amphimixis, (iii) heterogametic amphimixis, and (iv) homogametic automixis. Homozygous sexual populations are genetically stable if males or selection eliminate the excess females produced by heterozygous parthenogenetic genotypes. Homozygous parthenogenetic populations are stable if the parthenogenetic output of homozygotes exceeds that of heterozygotes. In turn, sex can only invade heterozygous parthenogenetic populations when sexual output of parthenogens is larger than their parthenogenetic output. The existence of interior stable equilibria generally requires the instability of at least one boundary and some degree of heterosis. In a two-locus model, we study the evolution of mechanisms protecting either sex or parthenogenesis in reproductively polymorphic populations. We find that males do not respond to the presence of parthenogenesis in such a way as to eliminate it, but parthenogenesis is subject to selective pressures increasing reproductive isolation, and thus the success of parthenogenesis. The results suggest that reproductively polymorphic populations are ephemeral.

Animals↗
PubMed1979

Prevention of postoperative vertical imbalance and ptosis.

A technique is described which has reduced our incidence of vertical muscle imbalance and ptosis following intraocular surgery. The eye is well fixated, bleeding is minimized, and the operative field is better exposed. It is a simple modification of the usual technique of globe fixation and should be considered by ocular surgeons to reduce the complications of iatrogenic muscle imbalance and ptosis.

Cataract Extraction↗