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Biomedical subjects

A M Joseph

Publications and source records attributed to A M Joseph.

27 records · Page 2Linked to original sources
PubMed1984

Estimation of aneuploidy levels in human spermatozoa using chromosome specific probes and in situ hybridisation.

The paper describes an attempt to estimate the frequency of aneuploid human spermatozoa with disomic Y chromosome and disomic chromosome 1 complements, using chromosome specific probes and in situ hybridisation. This approach was used as an alternative to the differential staining techniques that have been applied to spermatozoa in previous studies aimed at estimating levels of aneuploidy for chromosome 1 and the Y chromosome. A frequency of 1.8 per 1000 YY-bearing spermatozoa and 3.5 per 1000 disomy 1 spermatozoa was found, both figures being in excess of those found by sperm genome karyotyping. The technical limitations of the method are discussed.

Aged↗
PubMed1984

The morphological sequence of XY pairing in the Norway rat Rattus norvegicus.

The sequence of XY pairing at meiotic prophase in the Norway rat, Rattus norvegicus, has been studied in spread preparations of spermatocytes obtained from pubertal males. As in most mammals, sex chromosome pairing is delayed in relation to that of the autosomes. At one stage in pachytene, the Y is fully paired in synaptonemal complex association with about one-third of the X. Observation in spread preparations at pachytene and diplotene and in air-dried metaphase I preparations indicates that the long arm of the Y pairs with the short arm of the X. Pairing of the Y with both ends of the X is seen in about 4% of pachytene spermatocytes. The possibility that XY pairing in the rat may be nonhomologous (Ashley 1983) is considered, and the view is expressed that the XY synaptonemal complex may be incomplete in fine structural detail, thus not providing for the effective pairing required in true reciprocal recombination. The same mechanism that excludes crossing over from heterochromatic regions of autosomes may also operate to minimize or prevent crossing over in the sex pair of mammals.

Animals↗
PubMed1984

On the nature and extent of XY pairing at meiotic prophase in man.

Evidence is presented that pairing between the human X and Y chromosomes could be more extensive at early pachytene than has previously been supposed and could involve even the entire euchromatic portion of the Y chromosome. Following desynapsis over the major part of the X and Y axes, a small paired segment of Xp and Yp remains into late pachytene. Association between the distal tips of Xq and Yq can also be observed in about one half of the spermatocytes examined. A hypothesis linking meiotic pairing to early replicating sites along the chromosomes is proposed.

Adult↗
PubMedDate not supplied

Cost effectiveness of HemoQuant versus Hemoccult for colorectal cancer screening.

Initial reports on HemoQuant, a new quantitative test for occult gastrointestinal bleeding, suggest it is more sensitive than Hemoccult. Increased detection of upper gastrointestinal tract bleeding and dietary hemoglobin may reduce HemoQuant's specificity in the screening setting. The authors performed a cost effectiveness analysis comparing Hemoccult and HemoQuant for colorectal cancer screening using assumptions based on probabilities and costs in the current literature, varying the specificity of HemoQuant. The analysis showed the marginal cost effectiveness of Hemoccult versus no test to be $43,000, and HemoQuant versus Hemoccult to be $296,000 if HemoQuant specificity is 0.95. The marginal cost effectiveness ratio increased to $601,000 if three HemoQuant tests were used. Survival benefit was small and highly dependent on Hemoccult sensitivity and mortality from colonoscopy if HemoQuant specificity was less than 0.9. The authors conclude that unless the high sensitivity reported for HemoQuant is accompanied by a specificity comparable to that of Hemoccult, HemoQuant may not be an acceptable alternative for colorectal cancer screening.

Colonic Neoplasms↗
PubMedDate not supplied

Effect of treatment for nicotine dependence on alcohol and drug treatment outcomes.

This study was designed to examine the effect of a policy banning smoking and a smoking-cessation intervention on alcohol and drug treatment outcomes. We compared long-term alcohol and drug treatment outcomes in two cohorts hospitalized for substance use treatment, subjected to different smoking policies and cessation interventions in two periods. The study included 314 male patients, aged 18-65. The intervention cohort was subjected to a total hospital smoking ban and concurrent drug and nicotine dependency treatment, with a requirement for nicotine abstinence during hospitalization. The control cohort was hospitalized under a policy permitting smoking in designated areas, with no specific smoking-cessation intervention. Current alcohol, drug, and tobacco use were ascertained by follow-up interview with patients 8-21 months after completion of treatment. There was a 60% response rate in the intervention group (n = 92) and a 66% response rate in the control group (n = 105). Among respondents, there were no significant differences between intervention and control groups in rates of "improvement" for alcohol, cocaine, or marijuana use, or for these drugs combined, although there was a nonsignificant trend toward less "improvement" in the intervention group. When nonrespondents were analyzed as treatment failures, the rate of "improvement" was significantly worse for cocaine users in the intervention group, but not for other drug users or for all patients combined. Ten percent of patients reported quitting smoking in the intervention group compared to 4% in the control group (difference not significant). Although patients resisted the mandatory nature of the smoking intervention, many continuing smokers requested information and referral for smoking cessation at the time of follow-up. These data suggest that concurrent intervention for nicotine dependence did not significantly harm treatment outcomes of patients using alcohol or marijuana as their drug of first choice. Due to a trend in this direction, this possibility should be investigated in randomized, controlled trials. The intervention was associated with a small increase in self-reported smoking cessation. There is considerable interest in this patient population in smoking cessation after completion of treatment.

Adolescent↗
PubMedDate not supplied

Nicotine treatment at the Drug Dependency Program of the Minneapolis VA Medical Center. A researcher's perspective.

Substance use disorder treatment professionals historically have been reluctant to address tobacco dependence in their patients, despite a high prevalence of smoking, unique health effects, and evidence of physical addiction to nicotine. We performed two prospective studies to examine (1) the feasibility of a smoke-free policy and nicotine treatment program in an inpatient drug and alcohol treatment program, and (2) the impact of this intervention on long-term treatment outcomes. In both studies we used self-reported data from two groups of patients; one hospitalized after the implementation of the intervention and a historical control. The first set of data indicated that patients were more interested in quitting smoking and were more likely to abstain from smoking after the policy was implemented than before. They did not feel quitting smoking would threaten abstinence, and the policy did not increase early discharges. The second study failed to show that the change in policy was associated with an adverse effect on drug and alcohol treatment outcomes. A small but significant positive effect was demonstrated for smoking cessation. These studies also showed that many patients regard smoking as different from the primary drug that brought them to treatment. Randomized clinical trials testing a variety of smoking intervention techniques are desperately needed in this population to scientifically determine effective methods to decrease smoking.

Adolescent↗