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Biomedical subjects

R Reznik

Publications and source records attributed to R Reznik.

17 recordsLinked to original sources
PubMed2000

An adjacent thioester provides apical-directed stabilization to 3-isothiazolidinone 1-oxide heterocycles.

The structural and energetic features of the attractive intramolecular through-space S-X interaction [X being oxygen (O) or sulfur (S)] of thioester containing 3-isothiazolidinone 1-oxide heterocycles are described. Density functional theoretical and semiempirical calculations are used to explain the previous X-ray data on 3-isothiazolidinone 1-oxides 5 and 6 [Kanda, Y., Ashizawa, T. , Kakita, S., Takahashi, Y., Kono, M., Yoshida, M., Saitoh, Y., and Okabe, M. (1999) J. Med. Chem. 42, 1330-1332] and implicate a mechanism where the adjacent thioester participates in an apical-directed stabilization of the sulfur heterocycle. A key factor that distinguishes the S-O interaction from the S-S interaction is the stronger through-space interaction of the former, which is a consequence of the greater electronegativity of apical O compared to apical S. Reaction field theory reveals that the conversion of the S-O interaction to the S-S interaction is more facile compared to gas phase computations, which suggest a reduced importance of the 1,5-S-X interactions in solution. The conversion of the S-O interaction to the S-S interaction gives an isothiazolidinone oxide that places the reacting sulfurs in proximity with an orientation presumably suitable for bond formation and access to the dithiolanone oxide surface. Factors that influence the through-space S-X interactions may represent important issues in identifying target 3-isothiazolidinone 1-oxide prodrugs capable of rearranging to 1,2-dithiolan-3-one 1-oxide drugs.

Antibiotics, Antineoplastic↗
PubMed1994

The prevalence of tuberculosis infection among Year 8 schoolchildren in inner Sydney in 1992.

OBJECTIVE: To determine the prevalence of tuberculosis (TB) infection in Year 8 schoolchildren (aged 12-14 years) in Sydney. DESIGN: Cross-sectional survey. SETTING: 22 inner city Sydney secondary schools. PARTICIPANTS: 2290 Year 8 school children enrolled in 1992. OUTCOME MEASURES: Distribution of Mantoux test reaction size and proportion of children who were Mantoux positive (i.e., having Mantoux reaction > or = 15 mm with previous Bacille Calmette-Guérin vaccination; > or = 10 mm without). RESULTS: Of the 2290 children, 1836 (81%) were screened and 1801 Mantoux reactions were read. Ten per cent of children were Mantoux positive--27% of foreign-born children and 2% of Australian-born children (relative risk 16.7, 95% confidence interval 10.6-26.4). Two children were found to have active TB disease. CONCLUSION: There is a high prevalence of primary (non-contagious) TB infection in children aged 12-14 years in inner Sydney, mostly confined to children born overseas. Thus there is a large pool of infected children at risk of developing active (contagious) adult-type TB disease in the future. This public health problem should be addressed by identification and treatment of those infected.

Adolescent↗
PubMed1994

Work-site cholesterol screening and dietary intervention: the Staff Healthy Heart Project. Steering Committee.

OBJECTIVES: The Staff Healthy Heart Project was established to run a work-site cholesterol screening project and a randomized controlled trial of dietary interventions. METHODS: Screening was offered to all staff at six Australian hospitals. Participants with blood cholesterol of 5.2 mmol/L (200 mg/dL) or above were randomly allocated to receive screening only (control group), a self-help package, or a nutrition course. Participants were seen 3 and 6 months after intervention to measure blood cholesterol and dietary changes. RESULTS: Eighty percent of available staff (n = 2638) were screened. Of those eligible, 67% (n = 683) entered the trial. Follow-up measures of blood cholesterol and dietary intake were obtained for 63% and 38% of trial participants, respectively. A reduction in reported dietary fat was found for all groups, but there were no significant differences between groups. Reported dietary fiber rose by 0.6 g/MJ/day for those in the nutrition course. There were no changes in total blood or high-density lipoprotein cholesterol. CONCLUSIONS: Cholesterol reduction was not demonstrated, but this result is difficult to interpret given the poor ongoing participation rates. Strategies to improve ongoing participation in work-site projects are needed to achieve adequate assessment of dietary interventions used in cholesterol screening.

Adolescent↗
PubMed1992

Cultured human cord blood cells spontaneously produce a factor with basophil-promoting activity.

Cord blood is a source for pluripotential stem cells capable of differentiating into various hemopoietic cell lines in the presence of suitable specific growth factors. Without additional growth factors, cultured cord blood cells give rise to large numbers of basophils. We have recently defined a human basophil growth promoting factor, designated as interleukin-3-like activity (IL-3-LA), produced spontaneously by human monocytes and lymphocytes. In order to explain the phenomenon of spontaneous basophil development in cord blood cultures, we studied the relationship between basophil production and IL-3-LA release in these cultures. IL-3-LA produced by cord blood mononuclear cells increased from day 3 to day 14 and then decreased gradually by day 35. Basophil development was observed from day 14 on (33% +/- 6.4) and peaked on day 21 (51% +/- 7.4). Histamine release followed the same pattern i.e., 10 +/- 3.4 ng/ml on day 14, and 23 +/- 6.5 ng/ml on day 21. It is suggested that IL-3-LA spontaneously released by cord blood mononuclear cells induces basophil development in these cultures.

Basophils↗
PubMed1992

Using a computer database to record and evaluate a school screening service.

School screening has been taking place in New South Wales since 1907. The need for better monitoring of the school health service to determine the outcome of the screening process has been advocated frequently. This paper reports on the development of a computerized surveillance system which allows school screening to be evaluated on an ongoing basis. The results of the first year's use of the programme on a study population of children first screened in 1989 in a northern metropolitan area of Sydney demonstrate that the system is practical and effective when used by people with little or no prior computer knowledge. It plays a role in both improving follow-up of the screening process and the assessment of the service. The prevalence rate of new defects found was four per 100 children screened. Issues raised about the screening process from the data collected are also discussed.

Child↗
PubMed1987

Differences in mortality from acute myocardial infarction between coronary care unit and medical ward: treatment or bias?

To analyse the effectiveness of coronary care units in reducing mortality from myocardial infarction 18 hospitals ranging from large urban teaching hospitals to small country hospitals were stratified into four levels of care. Previous analysis had failed to show significant differences in the overall mortality in hospital among levels. There were significant differences in mortality, however, between those patients allocated to be cared for in the coronary care unit and those in the medical wards in the more advanced hospitals. The differences were largest in the hospitals with the most elaborate facilities (level 1) and non-existent in those with the least (level 4). Several analytical approaches to these observed differences indicated that they were: (a) reduced by adjustment for age and severity of infarction; (b) paralleled by differences in coexisting disease recorded on death certificates; (c) no longer significant at level 1 after allowing for differences in coexisting disease; and (d) not significant at any level after exclusion of patients first diagnosed at necropsy. These findings suggest that the observed differences in mortality between coronary care units and medical wards are largely due to bias in selection and diagnosis.

Age Factors↗
PubMed1987

Mortality from myocardial infarction in different types of hospitals.

Hospitals ranging from large urban teaching hospitals to small country hospitals were stratified into four levels of care and examined for their effectiveness of coronary care in relation to these levels. The crude hospital mortality among 2265 patients admitted for definite or possible acute myocardial infarction was 21% at level 1 (the most elaborate level), 22% at level 2, 21% at level 3, and 19% at level 4 (the least elaborate). Adjustment for age or other prognostic factors produced no significant differences across levels either for coronary care unit care or for combined coronary unit and ward care. Success in resuscitation was also similar across levels. These findings suggest that increased resources for coronary care units--whether for new services or for upgrading existing ones--may not be required.

Age Factors↗
PubMed1985

Health screening at school entry--what is achieved?

Evaluative research on screening in school children is needed because of a lack of studies about its effectiveness. This paper reports a study of the school medical records of 790 children, aged 5-6 years, first screened in 1980. Sixty-six per cent of the parents of children who were notified of an abnormality in their child were followed up to determine subsequent action. Although a complete physical examination had been performed, 87% of all notified abnormalities involved vision (including squint), hearing and dental problems. The prevalence rate of previously unknown health problems (excluding dental problems) confirmed by another health professional was 5%. This rate was lowered to 2% when only children with moderate or severe problems presently receiving treatment were included. Some of the practical problems and importance of screening are discussed.

Australia↗
PubMed1976

What is the function of a hospital for geriatric and chronic diseases?

The functioning of a hospital for chronic diseases was examined in terms of the type of patient referred, the course in the hospital and the eventual outcome, in a prospective study of a year's admissions to one department of Harzfeld Hospital in Israel. Of the 191 patients admitted, 55 percent were assessed as possible candidates for rehabilitation, and two-thirds were discharged. Among those admitted primarily for nursing reasons, the mortality was 76 percent. The average stay was 68 days for the 47 percent who were discharged and 95 days for the 45 percent who died; 8.4 percent remained as long-stay patients. Mobility improved in 37 percent and deteriorated in 8 percent; independence in self-care increased from 13 percent on admission to 51 percent on discharge. Thirty percent of the discharges occurred in the first month, and further 30 percent in the second month; 85 percent of these patients returned to their own homes. The hospital stay exceeded 6 months in 18 percent, of whom 7 percent died and 3 percent were later discharged. The possibility of release from the hospital was influenced by the degree of disability rather than the social circumstances. The best change for improvement was among the patients who required only partial help on admission. The most important tasks of the hospital were: intensive and sometimes prolonged rehabilitation; basic nursing care; medical reevaluation and sometimes referral for surgical salvage operations; attention to acute and subacute medical problems, some of which occurred as complications, including accidents; and the concentration of physiotherapy and occupational therapy where most needed. Achievement of these aims was based on fostering a cooperative spirit between patients and staff, adjusting to the problem of re-integrating the long-stay patient, and coordinating specialist services from other hospitals when needed.

Chronic Disease↗
PubMedDate not supplied

Evaluation of the Australian Medical Association drink-driving campaign in Wollongong.

A pilot public education campaign against drink-driving directed towards 18-24-year-old men in Wollongong in 1982 is described. Analysis suggested significant behavioural change in the target group. This was shown by a reduction in traffic accidents and by some reduction in drink-driving convictions. While a comparative assessment of the knowledge and attitudes of the community before and after the campaign showed a marked awareness of the campaign, attitudinal changes to drink-driving were equivocal.

Accidents, Traffic↗