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Biomedical subjects

P Sastry

Publications and source records attributed to P Sastry.

8 recordsLinked to original sources
PubMed2002

Contamination of environmental surfaces by genital human papillomaviruses.

OBJECTIVE: To investigate contamination of environmental surfaces with human papillomaviruses (HPV) DNA in two genitourinary medicine (GUM) clinics and in an on-site staff leisure and fitness centre. METHODS: Samples were collected from the treatment rooms and patients' toilets of two GUM clinics situated at two hospital sites and from the toilets of the staff leisure and fitness centre on one of the sites. Samples were tested for the presence of HPV DNA by nested polymerase chain reaction (PCR), and HPV amplicons were typed by reverse line hybridisation using HPV type specific oligonucleotide probes complementary to 35 HPV types. All samples were also tested for beta globin DNA by PCR in order to assess their quality. RESULTS: HPV DNA was found to be present at more than 50% of the sites sampled in one of the GUM clinics, but was absent in the second, and also from the staff leisure and fitness centre. All HPV DNA detected was found to be cell associated. The most commonly found HPV types were 6, 11, and 16, respectively. HPV infected cells were found to be localised mainly to surfaces used predominantly by medical staff. CONCLUSIONS: This study has identified contamination of the environment of a GUM clinic. Possible sources for the contamination of the clinic toilets were from genital sites via hands to the environment. Within the treatment rooms the most likely route of HPV DNA contamination of the environment was via the doctor's gloved hands.

Ambulatory Care Facilities↗
PubMed2001

Accommodation and refractive error in children with Down syndrome: cross-sectional and longitudinal studies.

PURPOSE: To examine the relationship between defective accommodation and refractive errors in children with Down syndrome. METHODS: Children with Down syndrome aged 4 to 85 months were seen at their homes as part of an ongoing study of visual development. Seventy-five children contributed cross-sectional data and 69 children longitudinal data. Accommodation was measured using a modification of Nott dynamic retinoscopy technique, and refractive error measurements were obtained using Mohindra retinoscopy. RESULTS: Accommodation was poor, regardless of the refractive error present. The total accommodation produced by the children was related to the refractive error at the time of the test, with the degree of accommodation deficit increasing with the amount of positive refractive error. The longitudinal results showed that although children with Down syndrome did not accommodate accurately, the amount of accommodation elicited did not reflect their maximum amplitude of accommodation. Each child showed a consistent degree of underaccommodation for a given stimulus. Spectacles to correct hypermetropia did not improve the accommodative response. CONCLUSIONS: In children with Down syndrome, underaccommodation is substantial, even when there is no, or a fully corrected, refractive error. The accommodation system of children with Down syndrome may have the physical capacity to respond to a given stimulus, but the neural control of the system has an anomalous set point. Spectacles do not remedy the situation. This has important implications, especially for children in a learning environment, because near vision is consistently out of focus.

Accommodation, Ocular↗
PubMed2000

The effect of age, size of target, and cognitive factors on accommodative responses of children with Down syndrome.

PURPOSE: To investigate possible factors that may be implicated in the poor accommodative responses of individuals with Down syndrome. This article evaluates the effect of age, angular size of target, and cognitive factors on accommodation. METHODS: Seventy-seven children with Down syndrome who are participating in an ongoing study of visual development were assessed. One hundred thirty-one developmentally normal children took part in a previous study and provided control data. Accommodation was measured using a modified Nott dynamic retinoscopy technique. RESULTS: Children with Down syndrome showed considerably poorer accommodative responses than normally developing children. No target used in the present study produced an improved response in children with Down syndrome. Age, angular subtense of target, and cognitive factors could not fully account for the poor accommodation in children with Down syndrome. CONCLUSIONS: Poor accommodation is a common feature of Down syndrome, regardless of the target used. The etiology of the deficit has yet to be established. It is imperative that educators and clinicians are aware that near vision is out of focus for these children.

Accommodation, Ocular↗
PubMed1997

Refractive errors in young children with Down syndrome.

Significant refractive errors are common among older children and adults with Down syndrome. We examined infants and children with Down syndrome to determine the prevalence of these errors at younger ages. Noncycloplegic retinoscopy was used to determine the refractive state of 92 infants and children with Down syndrome, aged 4 months to 12 years. The results for infants show a similar distribution of refractive errors in patients with Down syndrome and an age-matched control group. However, rather than a narrower distribution for the older age groups, as is the case with the controls, the distribution is wider, and the prevalence of refractive errors (including astigmatism) is higher among young children with Down syndrome than among controls. This high prevalence of refractive defects cannot be explained by the presence of strabismus or other pathologies.

Child↗
PubMed1996

Visual acuity and accommodation in infants and young children with Down's syndrome.

Accommodation and visual acuity were measured in 53 children with Down's syndrome aged between 12 weeks and 57 months. Results were compared with data for 136 control (typically developing) children aged between 4 weeks and 48 months. Whereas the control children accommodated accurately on near targets, accommodation was defective in 92% of the children with Down's syndrome, and there was no change in accommodative ability with age. On the other hand, visual acuity lay within normal limits for the younger children. Children over the age of 2 years showed a below-normal visual acuity, which is not explained either by refractive error or by the effect of poor accommodation. The data suggest a sudden change in the rate of development of visual acuity which may be associated with physiological changes in the visual cortex. Previously reported defects of accommodation and visual acuity in older children and adults with Down's syndrome are confirmed by our findings in infants and young children.

Accommodation, Ocular↗