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Biomedical subjects

G S Wilson

Publications and source records attributed to G S Wilson.

At least 91 records · Page 5Linked to original sources
PubMed1985

The health and educational status of adolescents with congenital rubella syndrome.

As part of a longitudinal study of children with congenital rubella syndrome, 53 adolescents between 16 and 18 years of age were surveyed to determine their health and educational status. The findings were compared with those at the 18-months evaluation. At 16 to 18 years neurosensory impairments, cerebral dysfunction and organic behaviour syndromes were predominant, but the majority of children had multiple handicaps. A higher proportion had hearing loss. Although all the hearing-impaired children were begun in oral-based educational programs, 90 per cent of those with severe to profound hearing-loss diagnosed before the age of 18 months had changed to total or manual communication. Those with mild to moderate hearing-loss diagnosed after 18 months primarily communicate orally. The educational implications of these findings are discussed.

Adolescent↗
PubMed1985

Factors affecting head growth and intellectual function in children of drug addicts.

The effect of maternal heroin and methadone use on head growth and neurodevelopmental performance was studied in preschool children of untreated heroin addicts (n = 25), women receiving methadone therapy (n = 26), and a drug-free comparison group (n = 41) who had been followed from birth. The mean birth head circumference of both groups of drug-exposed infants was significantly below that of the comparison group; however, the only factors determined by multiple regression analysis as associated with head size at birth were maternal nutritional status and birth weight. By preschool age, head size did not differ significantly among groups. The factors associated with postnatal head growth were birth weight, intrapartum risk score, and race. Data show an increased incidence of low-average and mildly retarded intellectual performance in the drug-exposed children. Regression analyses demonstrated that amount of prenatal care, prenatal risk score, and home environment were most predictive of intellectual performance and that the degree of maternal narcotic use was not a significant factor.

Age Factors↗
PubMed1984

Equivalent oxygen percentage (EOP) technique: a standard calibration curve.

Between different oxygen concentrations (mixed with nitrogen) ranging from 0 to 21% were passed over the corneas of six subjects for 5 min. The resulting corneal oxygen responses were measured by polarography. The averages of these responses were used to calculate a "relative oxygen uptake response" (ROUR) value for each oxygen percentage. Analysis of these ordered pairs revealed a curvilinear relation which was best described by a third order equation; marked linearity was demonstrated in the middle of the oxygen range. The use of this third order equation as a "standard" or "average" equivalent oxygen percentage (EOP) calibration equation is suggested.

Adult↗
PubMed1984

Oxygen tension measurements: a comparison of methodologies.

The equivalent oxygen percentage (EOP) technique of Hill and the technique of Rasson and Fatt are two commonly used methods to quantify the oxygen tension underneath a contact lens for the open-eyelid case. This study compares these two techniques. Five subjects and six contact lenses of various center thicknesses and oxygen transmissibilities were used. Each subject wore each lens for which the oxygen tension was measured by these two methods. For lenses of approximately 0.23 mm center thickness, the two methods gave similar oxygen values. For contact lenses significantly thicker or thinner, the two methods gave very different oxygen values. However, these oxygen values were related in a specific manner; a strong linear relation was found for contact lens center thickness vs. the ratio of the two oxygen values found by the two methods.

Adult↗
PubMed1984

Polarography: an oxygen survey correlating oxygen transmissibility to "EOP" values.

A polarographic oxygen electrode was used to measure the oxygen transmissibility of seven contact lenses of varying water content and center thickness. A similar electrode was used to measure the oxygen uptake following wear of these same contact lenses for both the open- and closed-eyelid conditions on five young healthy subjects. Linear regression revealed a strong correlation between oxygen transmissibility and equivalent oxygen percentage (EOP) values for both the open- and closed-eyelid conditions. This strong correlation between these two oxygen parameters shows both are useful in predicting the oxygen tensions across the tear-epithelial interface during contact lens wear.

Adult↗
PubMed1983

Spectral and electron transfer properties of Sepharose 6MB-immobilized cytochrome c.

Cytochrome c has been covalently attached to Sepharose 6MB to study the effects of immobilization on the molecule. A detailed study of the resulting product was conducted based on its three characteristic properties: spectra, oxidation-reduction potential, and biological activity. The spectral properties demonstrated that cytochrome c was essentially the same after attachment. No major conformational changes were indicated. The redox potentials for most samples of immobilized cytochrome c loaded with different amounts of protein were generally 20-25 mV lower than native cytochrome c (270 mV). Heavily loaded samples, however, showed no difference in potential. The Km values for immobilized cytochrome c with cytochrome oxidase and reductase from submitochondrial particles were comparable to the soluble protein. Vmax values are more strongly affected by immobilization, especially for the reductase. It has been demonstrated that the submitochondrial particles cannot penetrate the pores of the support material and therefore only the cytochrome c molecules on the surface are available for reaction. As a support material, Sepharose 6MB, which is CNBr activated, hydrolyzes at a significant rate at the pH of the coupling reaction, and this must be considered in establishing coupling conditions for protein immobilization.

Animals↗
PubMed1983

Survival of low-birth-weight infants with neonatal intraventricular hemorrhage. Outcome in the preschool years.

Twenty-nine low-birth-weight infants who survived neonatal intraventricular hemorrhage (IVH) were followed up prospectively and were last examined at a mean age of 3 1/2 years. The mean gestational age (+/- SD) of the group was 28.9 weeks (+/- 2.4 weeks), and the mean birth weight (+/- SD) was 1,167 g (+/- 292 g). Ten patients (34%) had normal neurologic outcome, and four (14%) had minimal abnormalities. Nine children (31%) were categorized as moderately abnormal, and six (21%) had severe abnormalities on neurologic examination. Intellectual performance was normal for 14 patients (48%), mildly delayed for seven (24%), and in the retarded range for eight (28%). Twelve children (41%), at 3 years of age, had handicapping conditions severe enough to warrant admission to special education programs in the public school. The grade of IVH was related significantly to neurologic outcome; both grade of hemorrhage and birth weight were correlated significantly with need for special education. Intellectual performance was related not only to grade of hemorrhage and birth weight, but also to paternal social class.

Birth Weight↗
PubMed1983

Fetal and postnatal growth of children born to narcotic-dependent women.

We studied the effect of heroin and methadone on birth length and 3-year stature of children of untreated heroin addicts (n = 22), women receiving methadone maintenance therapy (95% were polydrug users) (n = 21), and a drug-free comparison group (n = 28), after adjustment for biologic, demographic, and health variables. The mean birth lengths of both groups of drug-exposed infants were significantly below that of a comparison group; however, group means were similar after adjustment for sex, race, prenatal care, pregnancy weight gain, obstetrical risk, maternal education, and smoking. At 3 years of age the mean height was comparable for all groups. When adjusted for birth length, parental height, and smoking, the methadone group was significantly shorter than children exposed to heroin in utero, and the comparison group assumed an intermediate position. These data indicate that the effect of heroin and methadone on intrauterine growth cannot be differentiated from that of associated factors, and that postnatal growth of children exposed to narcotics during pregnancy is no more impaired than that of a high-risk comparison group. Children of all three groups deserve continued observation and efforts to improve their environment in order that their full potential might be achieved.

Body Height↗
PubMed1982

Analysis of dental materials as an aid to identification in aircraft accidents.

The failure to achieve positive identification of aircrew following an aircraft accident need not prevent a full autopsy and toxicological examination to ascertain possible medical factors involved in the accident. Energy-dispersive electron microprobe analysis provides morphological, qualitative, and accurate quantitative analysis of the composition of dental amalgam. Wet chemical analysis can be used to determine the elemental composition of crowns, bridges and partial dentures. Unfilled resin can be analyzed by infrared spectroscopy. Detailed analysis of filled composite restorative resins has not yet been achieved in the "as-set" condition to permit discrimination between manufacturers' products. Future work will involve filler studies and pyrolysis of the composite resins by thermogravimetric analysis to determine percentage weight loss when the sample examined is subjected to a controlled heating regime. With these available techniques, corroborative evidence achieved from the scientific study of materials can augment standard forensic dental results to obtain a positive identification.

Accidents, Aviation↗
PubMed1981

Follow-up of methadone-treated and untreated narcotic-dependent women and their infants: health, developmental, and social implications.

This study compares the first year's health, neurodevelopmental status, and environment of infants of drug-dependent mothers attending methadone programs during pregnancy with those of drug-dependent mothers not enrolled in treatment programs (untreated). Both groups were also compared with drug-free controls. During pregnancy, the use of heroin and other psychoactive drugs was common among patients using methadone. Neonatal abstinence syndrome was of longest duration in the methadone group. Infants of both drug groups were smaller at birth, had more neonatal infections, and were viewed as more difficult to care for after nursery discharge than were those of drug-free mothers. On follow-up, mean developmental scores were within the normal range for all groups. The untreated drug-dependent group was more hypertonic than the methadone group, and a high rate of transient or minor motor disturbances and poor attention span was found in both drug groups. The behavior of methadone-treated women during pregnancy and the postnatal period closely resembled that of drug-free controls, and contrasted with untreated drug-dependent women. Methadone-treated women had a high degree of compliance with antepartum care, and 80% continued in the role of parent through the first year. Further investigation will determine whether the consistency of parenting will continue and whether it will enhance the development of their children.

Adult↗
PubMed1981

Thickness measurement of hydrogel lenses.

The thickness of hydrogel lenses was measured in air with a Radiuscope and in saline with a specular microscope. The measurements are in good agreement, showing that drying is not a problem with air measurement. With a simple modification to the Radiuscope, the thickness measured is satisfactory for calculating optical power and oxygen transmissibility.

Calibration↗