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Biomedical subjects

S D Hill

Publications and source records attributed to S D Hill.

At least 19 recordsLinked to original sources
PubMed1998

Hemophilia growth and development study: relationships between neuropsychological, neurological, and MRI findings at baseline.

OBJECTIVE: To determine the effects of human immunodeficiency virus (HIV) infection on children's development by identifying neurological and environmental variables associated with neuropsychological measures of cognitive development in HIV-seronegative (HIV-) and HIV-seropositive (HIV+)children and adolescents with hemophilia. METHODS: Participants (N = 298; 60% HIV+) were males ages 7-19 years enrolled in the Hemophilia Growth and Development Study (HGDS). Least squares modeling was used to determine whether there was a difference at baseline in mean neuropsychological test scores by HIV status, age, and neurological baseline findings, adjusting for selected environmental and medical history variables. RESULTS: The participants were within age expectations for general intelligence. Variables associated with lowered neuropsychological performance included academic problems, coordination and/or gait abnormalities, parents' education, and previous head trauma. CONCLUSIONS: Hemophilia-related morbidity has a subtle adverse influence on cognitive performance. HIV infection was not associated with neuropsychological dysfunction in this group even when MRI abnormalities were present.

Adolescent↗
PubMed1996

Marshmallows cause an outbreak of infection with Salmonella enteritidis phage type 4.

Thirty-six cases of Salmonella enteritidis phage type (PT) 4 infection, mainly in children, were notified in one local authority in the two weeks beginning on 23 October 1995. Twenty-four cases and 42 controls nominated by cases were included in a case control study, which showed a significant association between illness and the consumption of marshmallow confectionery from a bakery. S. enteritidis PT4 was isolated from samples of the marshmallow, and all isolates had the same plasmid and pulsed field gel electrophoresis profiles. The marshmallow had been made using raw egg white, which shows that not all caterers follow the Department of Health's advice.

Case-Control Studies↗
PubMed1996

Effects of the argon laser on primary tooth pulpotomies in swine.

This study evaluated the clinical, radiographic, and histologic effects of the HGM PC Oralase argon laser on vital pulps of swine teeth. Pulpotomies were performed in vivo on 42 primary teeth from three young pigs and observed for 7 or 60 days. For each time period nine experimental teeth received an argon laser dose of 1 W, 2 sec (24.88 J/cm2), and nine experimental teeth received a dose of 2 W, 2 sec (49.74 J/cm2). Controls consisted of three teeth for each time period and did not receive exposure from the argon laser. There were no significant differences noted between the two energy densities with respect to clinical, radiographic, or histological parameters for either time period. All soft tissues remained normal and all teeth exhibited normal mobility at weekly assessments. Other than physiologic root resorption, there were no differences in pre- and postoperative radiographs in the 7 day sample; calcifications coinciding to dentinal bridges were visible radiographically in 8 of the 60-day samples. Reparative dentin formation was noted histologically in a total of 9 roots in the 7-day group and in 13 roots in the 60-day group. With the exception of teeth which had early restoration loss with resultant bacterial contamination, all other pulps appeared to retain their vitality and capability of normal pulpal healing. Use of the argon laser at the parameters described in this study did not appear to be detrimental to pulpal tissues.

Animals↗
PubMed1991

Comparison of antimicrobial and cytotoxic effects of glutaraldehyde and formocresol.

The in vitro antimicrobial and cytotoxic concentrations of glutaraldehyde and formocresol were determined. Minimal antimicrobial concentrations of these two agents against selected microbial flora reported in carious primary teeth were 3.125% for glutaraldehyde and 0.75% for formocresol. At a doubling of these concentrations, most organisms, except Candida albicans, Staphylococcus epidermidis, and Streptococcus mutans, were killed by both substances in 30 seconds. Cytotoxicity was evaluated on tissue cultures of pulp fibroblasts and HeLa cells at minimal cidal concentrations and at 10- and 100-fold dilutions. Exposure of pulp fibroblasts and HeLa cells to formocresol and indirect exposure to vapors caused the cells to become atrophic and to form a less dense tissue pattern. Cells directly exposed to glutaraldehyde retained their normal cell shape and tissue pattern, whereas cells indirectly exposed to vapors continued to proliferate. These data showed effective antimicrobial activity at concentrations of 3.125% glutaraldehyde and 0.75% formocresol and suggested that glutaraldehyde may exert a less cytotoxic effect on the immediate and surrounding tissues when used as a pulpotomy agent.

Bacteria↗
PubMed1991

Reflex sympathetic dystrophy and electroacupuncture.

Reflex sympathetic dystrophy (RSD) is a painful and progressively debilitating condition. Untreated, it leads to changes in the patient's lifestyle that are consistent with chronic pain syndrome. This general overview of contributing factors, signs and symptoms, diagnosis, and treatment of RSD presents three consecutive cases for which electroacupuncture (EA) proved to be an effective treatment for RSD pain. Possible underlying neuroanatomical mechanisms of RSD are addressed and the scientific basis for EA is considered briefly.

Adult↗
PubMed1990

A direct surgical approach to correct the inverted nipple.

Inverted nipples are cosmetically unpleasing to the patient and can become inflamed due to mechanical difficulty with cleaning the nipple-areola complex. A surgical technique for the permanent repair of inverted nipples is described. The rationale for the surgical approach is that the major pathophysiologic basis for nipple inversion is shortened lactiferous ducts. Briefly outlined, under local anesthesia, the nipple is everted with a skin hook and held in gentle traction while a small incision is made on each side at the nipple-areola junction. Breast ducts are then divided by sharp dissection, and a drain is inserted through the tunnel under the nipple. The drain is removed in 7 to 10 days. The patient must be informed before the procedure that breast-feeding will not be possible afterward because breast ducts will be permanently divided. Advantages to the procedure are (1) no scars on the areola, (2) no stricture from sutures, (3) adequate blood and nerve supply to the nipple, and (4) decreased risk of hematoma.

Adult↗
PubMed1989

Cognitive and physiological responsiveness of abused children.

Videotaped scenes of everyday events were shown to hospitalized abused and nonabused children and to a nonhospitalized peer group. The children's heart rates were taken as they viewed the scenes and they responded to questions about the content of the scenes. The hospitalized children reacted to the scenes with a larger decrease in heart rate than did the nonhospitalized children. The abused children reported more negative outcomes to the scenes, more negative feelings, and that they had experienced the events depicted more often than did either group of nonabused children.

Adolescent↗
PubMed1984

Neonatal responsiveness as a function of maternal contact and obstetrical drugs.

This work was designed to study changes in neonatal behavior during the first two days of life. Infants in Part I were from middle-class backgrounds. Half of these infants had unrestricted maternal contact during the first two days of life, the other half had contact with their mothers only at feeding time. Infants in Part II were from low socio-economic backgrounds. They were cared for entirely by the nursery staff during the first two days of life, so that differences in maternal style did not affect their behavior. Half of these babies were born to mothers who received 50 mg meperidine during labor, half to mothers who received no meperidine. This work provided evidence for the sensitivity of the neonate during the first two days of life. Both those infants who received unrestricted maternal contact and those whose mothers had received no obstetrical drugs exhibited more behavioral change than those who received low maternal contact or whose mothers had received meperidine during labor. High maternal contact and absence of obstetrical drugs also resulted in increased sensitivity to some environmental stimuli.

Attention↗
PubMed1981

Organ culture passage enhances the oncogenicity of carcinogen-induced hyperplastic mammary nodules.

The purpose of this study was to determine whether culturing hyperplastic mammary nodules in hormone-free medium would enhance their oncogenicity following subsequent transplantation into mammary fat pads. The underlying hypothesis is that the proliferation of transformed cells within the nodules is inhibited by hormone-dependent normal cells also present in the nodules. Accordingly, both primary hyperplastic nodules and tissues from a hyperplastic outgrowth of a primary nodule were maintained as organ cultures for varying periods in hormone-free Medium 199. The results show that whereas noncultured nodules developed mammary tumors at an incidence of only 15%, those passaged in organ culture gave rise to mammary tumors at an incidence of 40 to 43%. This threefold enhancement in the oncogenicity of mammary nodules is interpreted to be due, at least in part, to a reduction in the normal mammary cell content of nodules. Consistent with this interpretation is the observation that cultured nodules gave rise to mammary outgrowths that were predominantly hyperplastic, whereas noncultured nodules generated outgrowths with varying proportions of hyperplastic and normal ductal mammary tissue.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1981

Self-recognition in retarded children.

This study was designed to investigate the relationship between cognitive and affective development. Young preverbal retarded children watched TV images of themselves with faces marked or unmarked and of a peer whose face was marked. We used the objective technique of increased mark-directed responses as evidence of self-recognition and rated the children's reactions as they watched these images. The emergence of self-recognition was closely tied to the maturity of the children's general responsiveness to their reflections. The Down's syndrome children made a broad range of responses, including the curiosity and self-conscious behaviors characteristic of normal children during the second year of life, and all except one of these children showed evidence that they recognized their images. In contrast, the range of behaviors displayed by multihandicapped children was greatly restricted and similar to children in the first year of life. Less than half of these children showed an emergence of self-recognition.

Body Image↗
PubMed1980

The responsiveness of autistic children to the predictability of social and nonsocial toys.

This study was designed to explore autistic children's ability to develop an expectancy from environmental events. Social and nonsocial toys were presented to autistic and control children in situations that either allowed or prevented them from predicting their appearance. It was found that autistic children's behavior was seriously disrupted if they could not predict the sequence of environmental stimuli, but their responsiveness to environmental stimuli increased when events were predictable. They approached social objects more readily than nonsocial objects when both were simple in appearance. These findings suggest that an appropriate starting point for therapeutic intervention with autistic children might be to focus on shaping social play in highly structured and predictable environments.

Autistic Disorder↗
PubMed1980

Stereotyped behaviour in elderly patients with chronic organic mental disorder.

The presence of a variety of stereotyped behaviors was verified by observing four residents of a long-term care facility for one-hour each and recording repetitive picking, rubbing, manipulating other parts of the body, vocalizations, manipulation of objects, and sanding. It was found that at least one form of stereotyped behavior was recorded 87% of the total observation time. The overall inter-rater reliability across patients was 91%. Twenty-six patients from another long-term care facility were than randomly chosen, 13 of whom had diagnoses of cortical atrophy, and were observed for an average of 30 seconds each. A trained observer, blind to the diagnoses and to the number of such cases included in the sample, observed stereotyped behavior in and only in the 13 patients with confirmed diagnoses of cerebral dysfunction. A possible mechanism and potential clinical relevance are discussed based upon these observations.

Aged↗
PubMed1978

Self-recognition and stimulus preference in autistic children.

A common notion regarding autistic children is that they do not show self-recognition. In this study, 7 autistic children were compared to a group of normal infants at the age of self-recognition. Using a videotape "mirror image" and an objective self-recognition criterion, we observed that 6 of the 7 autistic children exhibited self-recognition. In a 2-choice preference situation, autistic children tended to prefer the more predictable mirror image to a previously taped film of self.

Autistic Disorder↗