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Biomedical subjects

S Lewin

Publications and source records attributed to S Lewin.

At least 37 records · Page 2Linked to original sources
PubMed1997

Down syndrome with biparental inheritance of der(14q21q) and maternally derived trisomy 21: confirmation by fluorescent in situ hybridization and microsatellite polymorphism analysis.

Individuals with translocation Down syndrome (DS) often inherit the rearranged chromosome from a carrier parent. DS due to inheritance of one Robertsonian or derivative (14q21q) from one parent and a second der(14q21q) in addition to a free chromosome 21 from the other parent are rarely documented in liveborn infants. Presented here is such a propositus with DS and with a unique karyotype 45,XY,der(14;21) (p11.1;p11.1)pat,der(14;21)(p11.1;q11.1)mat, +21mat. Using conventional chromosome heteromorphisms, fluorescent in situ hybridization (FISH), and microsatellite polymorphism analyses, we established the biparental origin of the 2 der(14q21q) and the maternal origin of the extra chromosome 21 in the patient. A combination of both cytogenetic and molecular genetic techniques also enabled us to show that the 2 der(14q21q) were not identical by descent and hence the parents were nonconsanguineous. It has been a well-established fact that mothers with Robertsonian translocations have higher risk for nondisjunction than do carrier fathers. Our case, wherein the nondisjunctional event occurred in the mother, even though both parents are carriers of a 14;21 Robertsonian translocation, is yet another example of this.

Chromosome Banding↗
PubMed1997

Mating and hormonal triggers regulate accessory gland gene expression in male Drosophila.

Drosophila melanogaster males transfer accessory gland proteins, as part of their seminal fluid, to females during each mating. Since accessory gland proteins are important for male reproductive success, it is important that the male replenish the proteins he transferred during mating. Previous studies had shown that mating induces the resynthesis of accessory gland proteins, but since mating includes a set of stereotyped behavior patterns as well as the act of copulation, it was not known which aspect of the mating process induces accessory gland protein synthesis. By exposing males to females whose ovipositors had been sealed shut, we have shown that resynthesis of accessory gland proteins occurs only when seminal fluid is transferred to females. By applying juvenile hormone or 20-hydroxyecdysone topically to the cuticle of male flies, we showed that these hormones can act in vivo to stimulate the synthesis of accessory gland proteins to levels similar to those observed after mating.

Journal Article↗
PubMed1997

Most patients attending a 'walk-in' clinic at Red Cross War Memorial Children's Hospital could safely be managed at primary care level.

OBJECTIVES: (i) To ascertain what proportion of patients attending the general medical outpatient service at Red Cross War Memorial Children's Hospital (RXH) could safely be managed at peripheral primary care facilities; and (ii) to measure the effect of the introduction of free health care for children under 6 years of age on requirements for levels of care ranging from home to super-specialist referral centres. DESIGN: Prospective survey of patients attending on a stratified, randomised sample of 7 days in March 1994 (N = 1 962) and again in November 1994 (N = 1 404)-before and after the introduction on 6 June 1994 of free care for children under 6 years of age. SETTING: The general outpatient department of an academic/referral children's hospital. PATIENT SELECTION: All patients attending the outpatient department on the study days (7h00 to 6h59 the following day), excluding those who were referred, returning for follow-up, attending a specialist clinic or attending the surgical outpatient department. QUESTIONNAIRE: The questionnaire completed by medical officers recorded the following: patient's name, folder number, date and time of arrival, whether referred, clinic, treating doctor, disposal, diagnoses, home suburb and the level of care required: (i) home: (ii) clinic without a doctor; (iii) clinic with a doctor; (iv) hospital with non-specialists; (v) hospital with general paediatricians; or (vi) super-specialist hospital. MAIN RESULTS: In March 1994 the percentages of unreferred patients requiring the 6 levels of care defined for the study were 0.3, 25, 62, 8, 3 and 1, respectively. In November 1994 the percentages were 4, 41, 43, 8, 4 and 1. The graph of the number of patients seen at the outpatient department each month shows a large month-to-month variation but the trend is clearly towards an increase. CONCLUSIONS: The general medical outpatient department at RXH provides care to a large number of children, 48% of whom are unreferred. Of the unreferred patients 95% could be treated (more appropriately for the health services and more conveniently for their families) at a local primary health care facility. The situation has been aggravated by the introduction of free care for children under 6 years of age, who constitute 83% of the unreferred workload.

Child Health Services↗
PubMed1995

The kinetics of surface expression of CD11/CD18 integrins and CD54 on monocytes and macrophages.

Cells of the macrophage lineage mediate extremely important normal functions of the immune system. Such functions are in part related to interactions between cell-bound LeuCAMs and their ligands. MoAb staining and flow cytometric analysis were used to follow changes in surface expression of LeuCAMs and the LFA-1 ligand CD54 during maturation of peripheral blood monocytes (BM) in vitro. Surface expression of these molecules increased on BM following isolation, the greatest increase being in CD54 and CD11c. Following an initial increase, there was a reduction in CD11a expression after 2 weeks in culture, this being greater on adherent compared with suspension-maintained cells. Expression of CD11b remained high throughout the culture period. LeuCAM and CD54 expression was further compared on freshly isolated alveolar macrophages (AM) and BM paired donors. A reciprocal relationship was observed between CD11c and CD11b on AM and BM, in that BM expressed higher levels of CD11b than CD11c, whilst the converse was true for AM. CD54 expression was also higher on AM than on BM, whilst there was no significant difference in expression of CD11a on these cells. These data suggest that consistent changes occur in the surface expression of the LeuCAMs and CD54 as monocytes mature into macrophages, which may reflect the specific functions of these cells.

CD11 Antigens↗
PubMed1993

Comparison of rectal and axillary temperatures in neonates admitted to a neonatal unit.

To determine whether axillary temperature could be used as an alternative to rectal temperature, 45 neonates were subjected to simultaneous rectal temperature and axillary temperature recordings. Each baby had an average of 10 recordings over the first 72 hours. The mean of these readings was taken and subjected to regression analysis and the 't' paired test. The overall mean difference between the rectal and axillary temperature was 0.3 degrees F. The mean difference was least in preterm small for date (SFD) babies (0.2 degrees F) and most in preterm appropriate for date (AFD) babies (0.5 degrees F). The mean difference was less in incubator babies (0.2 degrees F) compared to those in warmer cradles (0.4 degrees F). The regression analysis showed that the correlation was good in all groups except the term small for date babies. We conclude that axillary temperature could be used as an alternative to rectal temperature in neonates.

Axilla↗
PubMed1988

Neurofibromatosis and psychological processes.

A minimal degree of mental handicap is commonly seen in neurofibromatosis (NF). Despite the prevalence, little is known about the nature of the mental handicap. In this study, schoolchildren with NF and unaffected siblings were studied clinically and given a series of psychological tests. The psychological battery consisted of standardized tests of intelligence and cognitive processing, laboratory tests of cognitive processing, and personality and mood questionnaires. Clinical data included a medical and family history, results of physical, audiological, and ophthalmological examinations, EEG, tissue biopsy when necessary, and (in NF individuals) a CT scan. Results demonstrate slightly deficient cognitive processing in the NF individuals, particularly in terms of visual-spatial integration. These deficits are related to age-independent severity with more severely affected individuals exhibiting more severe deficits. The findings are discussed in terms of their diagnostic and prescriptive implications.

Adolescent↗