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Biomedical subjects

B Rogers

Publications and source records attributed to B Rogers.

At least 19 recordsLinked to original sources
PubMed1992

Phase I and pharmacokinetic study of the novel platinum analogue CI-973 on a 5-daily dose schedule.

CI-973, a platinum(II) derivative with a 2-methyl-1,4-butanediamine carrier ligand, has activity in cisplatin-resistant tumor models in vitro and in vivo. In a Phase I pharmacokinetic study, 31 patients were treated with CI-973 (24 to 50 mg/m2/day for 5 days; 28-day cycles) given i.v. over 30 min without routine antiemetic prophylaxis or hydration. Of the 29 patients evaluable for maximum tolerated dose determination, most had a performance status of 0 or 1, and most had received prior chemotherapy. Neutropenia was dose limiting at 40 and 50 mg/m2/day. Recovery from neutropenia was generally rapid with nadir counts and recovery usually occurring by Days 15 and 22, respectively. Drug-associated thrombocytopenia was uncommon and never severe, even in patients with Grade 4 neutropenia. Anemia was common, but did not appear dose related. Drug-related nausea and vomiting and changes in renal function were relatively infrequent and mild. No clinically evident ototoxicity was reported, although changes in audiograms were noted in several patients. CI-973 concentrations were measured in plasma ultrafiltrate and urine by high-pressure liquid chromatography. The harmonic mean terminal half-life was 2.0 h. The mean CI-973 renal and nonrenal clearance values were 42.3 and 37.4 ml/min/m2, respectively. The mean recovery of CI-973 in urine was 53% of the administered dose. The mean ratio of CI-973 renal clearance to creatinine clearance was 0.92. Total clearance correlated with creatinine clearance (r2 = 0.63). A relationship between toxicity, expressed as the percentage of reduction in absolute granulocyte count, and area under the CI-973 plasma concentration-time curve was found in a subgroup of "good-risk" patients. This relationship, described well by a sigmoidal Emax pharmacodynamic model, did not hold for patients with extensive prior therapy or poor performance status. A model for toxicity prediction based on dose and creatinine clearance has been derived and will be validated in future studies. The recommended Phase II dose of CI-973 is 30 mg/m2/day for 5 days.

Adolescent↗
PubMed1992

In situ localisation of single-stranded DNA breaks in nuclei of a subpopulation of cells within regenerating skeletal muscle of the dystrophic mdx mouse.

Degeneration of muscle fibres during the early stages of Duchenne Muscular Dystrophy (DMD) is accompanied by muscle fibre regeneration where cell division and myoblast fusion to form multinucleate myotubes within the lesions appear to recapitulate the events of normal muscle development. The mechanisms that govern the expression of genes regulating differentiation of myoblasts in regenerating skeletal muscle are of great interest for the development of future therapies designed to stimulate muscle regeneration. We show here that single-stranded breaks in DNA are localised in nuclei, using an exogenously applied medium containing labelled deoxynucleotides and the Klenow fragment of DNA polymerase I. The nuclei of a sub-population of cells lying in the inflammatory infiltrate of lesions in the skeletal muscle of the muscular dystrophic mouse (mdx), a genetic homologue of DMD, were labelled in this fashion. By contrast, labelled cells were completely absent from the muscles of normal non-myopathic animals (C57BL/10) and non-lesioned areas of mdx muscles. Cells expressing the muscle-specific regulatory gene, myogenin, were also found within mononucleate cells and myotubes within similar mdx muscle lesions. While we cannot yet say that the cells labelled by the DNA polymerase reaction are in fact differentiating, they were found only in significant numbers within mdx muscle lesions where new muscle fibres appear, providing strong circumstantial evidence that they are intimately associated with the regenerative process. Using a range of nucleases and different DNA polymerases, we show that the DNA polymerase-labelling reaction observed was DNA-dependent and most probably due to infilling of naturally occurring single-stranded gaps in DNA. Since the regenerative process in human Duchenne Muscular Dystrophy is apparently less effective than that seen in mdx mice, continued study of single-stranded DNA breaks may help to elucidate further the mechanisms controlling the expression of genes that characterise the myogenic process during skeletal muscle regeneration. Such findings might be applied in the development of future therapies designed to stimulate muscle regeneration in human dystrophies.

Animals↗
PubMed1992

Chronic regurgitation among persons with mental retardation: a need for combined medical and interdisciplinary strategies.

A survey of institutionalized adults with severe mental retardation and chronic regurgitation was conducted. A high prevalence of dysphagia and gastroesophageal abnormalities was found. Many of these abnormalities require further evaluation and treatment prior to the diagnosis of rumination. More studies are needed to explore the causes and treatment approaches for chronic regurgitation in adults with developmental disabilities.

Adult↗
PubMed1991

Orientation disparity, deformation, and stereoscopic slant perception.

Koenderink and van Doorn's theory, that the basis of stereoscopic slant perception is the deformation component of the disparity, field, was tested for slant around a horizontal axis, which produces images with a vertical ramp of horizontal disparity (horizontal shear) characterised by a global orientation disparity at the vertical meridian. The disparity field in this case can be parsed into two components, deformation and curl, which each contribute half of the orientation disparity. This case was compared with similar random-dot stimuli in which the deformation component was doubled and the curl component eliminated or vice versa. All three types of stimuli had identical orientation disparity at the vertical meridian. A condition in which there was no such orientation disparity, but deformation was present, was also included. It was found that perceived slant was not related to the deformation present, as Koenderink and van Doorn's theory would predict, but was predictable from the orientation disparity at the vertical meridian per se.

Depth Perception↗
PubMed1991

Smoking policies in health science schools.

Although cigarette smoking has decreased significantly in the last 25 years in the United States, it continues to be a major contributor to morbidity and premature mortality. All 704 U.S.-accredited health science schools were surveyed to determine the existence and scope of smoking policies, smoking cessation programs, and related activities in these schools. The aim was to encourage health care-related organizations, institutions, and professionals to accept leadership roles in smoking prevention and cessation. Of 517 (73%) respondents, 339 reported some form of smoking policy; however, restriction was primarily prohibited in classrooms and elevators. Vending of cigarettes was reported in up to 17% of schools, and smoking-related illness complaints were reported by 31%. Smoking programs and information were minimally offered. Health science schools must be more aggressive in their approaches to dealing with smoking prevention and cessation, and assume a more proactive leadership role toward achieving a smoke-free environment.

Health Policy↗
PubMed1991

Tobacco consumption declining faster in Canada than in the US.

Consumption and prices of tobacco products in Canada and the United States are compared over the period 1981 to 1989. In Canada, consumption has fallen from a higher level and at a faster rate than in the United States (3.52 kg/adult to 2.48 kg/adult vs 3.21 kg/adult to 2.48 kg/adult). With respect to cost, the real tobacco price index in Canada has grown faster than its US counterpart. These results are attributed to higher taxation practices, vigorous legislation, and the leadership role adopted by the Canadian government during the 1980s.

Advertising↗
PubMed1991

Overview of work-related hazards in nursing: health and safety issues.

Nurses working in hospital environments are exposed to a number of occupational health hazards. For five categories of hazards we present research-based documentation of potential and actual health-related problems, and avenues for health promotion and prevention of exposures. Both personal and organizational responsibilities for self-health protection are addressed.

Humans↗
PubMed1991

Occupational health nursing education. Curricular content in baccalaureate programs.

It is important that occupational health nursing content be offered in academic institutions to support the scope of practice in the specialty. Less than 50% of the schools responding (N = 215) included content specific to occupational health nursing concepts and practice, related fields of knowledge, and management of the occupational health unit. Occupational health nurses in practice settings and educational institutions should collaborate on the development of occupational health content in nursing school curricula.

Curriculum↗