Biomedical subjects

J S Hasan

Publications and source records attributed to J S Hasan.

3 recordsLinked to original sources

PubMed2000

Psychological issues in cosmetic surgery: a functional overview.

The relevance of psychological issues in cosmetic surgery has been well established in the literature. Early articles considered psychopathology to be prevalent in the plastic surgery population, whereas more recent views consider the typical cosmetic surgery candidate to be more psychologically stable. Despite these changes, the potential for psychopathology continues to be recognized. Consequently, screening for psychopathology during the preoperative interview has remained essential. To facilitate a working knowledge of psychological issues that may be useful in preoperative screening, this article reviews the current literature on the psychology of plastic surgery. In addition to discussing the psychological impact of cosmetic surgery, patient's motivations and expectations for surgery are discussed in the context of self-image. After reviewing potential types of psychopathology, various preoperative screening techniques are discussed.

Anxiety Disorders↗

PubMed1997

MarCell software for modeling bone marrow radiation cell kinetics.

Differential equations were used to model cellular injury, repair, and compensatory proliferation in the irradiated bone marrow. Recently, that model was implemented as MarCell, a user-friendly MS-DOS computer program that allows users from a variety of technical disciplines to evaluate complex radiation exposure. The software allows menu selections for different sources of ionizing radiation. Choices for cell lineages include progenitor, stroma, and malignant, and the available species include mouse, rat, dog, sheep, swine, burro, and man. An attractive feature is that any protracted irradiation can be compared with an equivalent prompt dose (EPD) in terms of cell kinetics for either the source used or for a reference such as 250 kVp x rays or 60Co. EPD is used to mean a dose rate for which no meaningful biological recovery occurs during the period of irradiation. For human as species, output from MarCell includes: risk of 30-day mortality; risk of whole-body cancer and leukemia based either on radiation-induced cytopenia or compensatory cell proliferation; cell survival and repopulation plots as functions of time or dose; and 4-week recovery following treatment.

Animals↗

PubMed1996

Modeling marrow damage from response data: evolution from radiation biology to benzene toxicity.

Consensus principles from radiation biology were used to describe a generic set of nonlinear, first-order differential equations for modeling toxicity-induced compensatory cell kinetics in terms of sublethal injury, repair, direct killing, killing of cells with unrepaired sublethal injury, and repopulation. This cellular model was linked to a probit model of hematopoietic mortality that describes death from infection and/or hemorrhage between 5 and 30 days. Mortality data from 27 experiments with 851 dose-response groups, in which doses were protracted by rate and/or fractionation, were used to simultaneously estimate all rate constants by maximum-likelihood methods. Data used represented 18,940 test animals: 12,827 mice, 2925 rats, 1676 sheep, 829 swine, 479 dogs, and 204 burros. Although a long-term, repopulating hematopoietic stem cell is ancestral to all lineages needed to restore normal homeostasis, the dose-response data from the protracted irradiations indicate clearly that the particular lineage that is critical to hematopoietic recovery does not resemble stemlike cells with regard to radiosensitivity and repopulation rates. Instead, the weakest link in the chain of hematopoiesis was found to have an intrinsic radioresistance equal to or greater than stromal cells and to repopulate at the same rates. Model validation has been achieved by predicting the LD50 and/or fractional group mortality in 38 protracted-dose experiments (rats and mice) that were not used in fitting of model coefficients.

Animals↗