Biomedical subjects

R S Clemett

Publications and source records attributed to R S Clemett.

At least 19 recordsLinked to original sources

PubMed1992

Retinopathy of prematurity: risk factors in a prospective population-based study.

A prospective study of risk factors for retinopathy of prematurity (ROP) in all very low birthweight (less than 1500 g) infants born in New Zealand in 1986 is reported. Of 413 liveborn infants admitted to neonatal units, 338 (81.2%) survived to be discharged home. Of surviving infants, 313 (93%) were examined by indirect ophthalmoscopy, as were eight infants who died before discharge. Sixty-nine infants (21.5% of 321) had acute retinopathy. On multiple logistic regression analysis, three variables made statistically significant independent contributions to the risk of any acute retinopathy; gestational age (P less than 0.0001), principal hospital caring for the infant (P less than 0.01) and treatment with indomethacin (P less than 0.01). Only two variables, gestational age (P less than 0.0001) and hospital (P less than 0.01), made significant contributions to the risk of stage 2 or more ROP. For both categories of ROP, timing of the examination also had a statistically significant effect (P less than 0.001). After adjustment for other significant predictor variables, it was estimated that approximately 70% of infants of less than 26 weeks' gestation were at risk of ROP and nearly 50% of stage 2 or more ROP, in comparison with less than 2% of infants of 32 weeks' gestation or more; infants treated with indomethacin were over 1.5 times more likely to have ROP than infants not so treated. Failure to enforce uniform timing of examination was the most serious defect in the study; only 205 (64%) of the 321 infants were examined at the recommended time. However, reanalysis of the model with information limited to these 205 infants yielded similar risk factors. The incidence of ROP, both observed (P less than 0.05) and adjusted for other significant variables in the regression model (P less than 0.01) was lowest in the two largest level III hospitals. These hospitals also had the best survival rates after adjustment for birthweight, gestation and gender (P less than 0.01). We speculate that the larger level III units obtained better results because their size and experience enabled them to provide a better overall quality of care.

Acute Disease↗

PubMed1991

Bungy jumping.

Explore the source record for details and available documents.

Athletic Injuries↗

PubMed1990

Serum and neutrophils alter the rate of excretory/secretory antigen release by Toxocara canis infective larvae in vitro.

Infective larvae of Toxocara canis are well suited for studies of nematode antigen expression in vitro. Larvae were labelled with 3H-glucosamine, an approach permitting dual analysis of antigen quantity and composition. Their excretory/secretory (E/S) glycoproteins were efficiently labelled and antigen identity confirmed by immunoprecipitation, SDS-PAGE and fluorography. Compartmental analysis revealed that common components of Mr 100-120 kD were present in somatic, surface and soluble material. The application of biosynthetic labelling and compartmental analysis of parasite responses in vitro to antibody, complement and neutrophils was tested. Results indicated that test larvae in vitro respond by quantitative rather than qualitative changes in antigen production. Specifically, human serum was shown to raise, and neutrophils depress, the rate of antigen release. The implications of these findings for establishing an in-vitro model for analysis of host/parasite reciprocal adaptive responses are discussed.

Animals↗

PubMed1990

Retinopathy of prematurity: screening and optimal use of the ophthalmologist's time.

In recent years it has been standard practice to recommend that indirect ophthalmoscopy be carried out between six and nine weeks of age in very low birthweight infants to screen for the presence of retinopathy of prematurity (ROP). Following this recommendation we examined 85 infants over a two-year period. Acute ROP occurred in 29 (34%), and two (2.4%) developed cicatricial disease. One-third of infants were initially examined slightly earlier or later than the strict six to nine week limits, but all except three infants were examined between 35 and 42 weeks gestation. One infant born at 26 weeks gestation, was examined 'too late' in that she had stage 4 disease when first seen at 11 weeks of age. Recent information on the natural history of ROP, and confirmation of the efficacy of treatment with cyotherapy, suggested that the timing of an initial screening examination for ROP needed reassessment. From our experience and a review of the literature we recommended that infants of less than 1000 g birthweight or less than 28 weeks gestation have an initial examination at six weeks of age; for infants of 1000 to 1250 g birthweight or 28 to 30 weeks gestation examination continue to be at six to nine weeks of age; and for infants of more than 1250 g birthweight or 31 weeks gestation screening at six to nine weeks of age is only necessary if the infant has had an unstable course or prolonged oxygen requirements. Such a protocol would not place too great a burden on ophthalmological services and would direct efforts towards the group of infants most at risk of severe visual handicap.

Follow-Up Studies↗

PubMed1990

Sunglasses: are they necessary in Christchurch?

Concern over potential eye injury from sunlight prompted this study to see if the levels of sunlight in Christchurch posed a particular risk to our population's eyes, whether the populace was aware of any risk and whether effective sunglasses were freely available to the public. While there has been a 4% to 9% increase in UV radiation since 1969 due to global ozone depletion, no firm evidence was found that focal ozone depletion was a particular problem in New Zealand. Christchurch residents were poorly informed about the ocular hazards of sunlight. A questionnaire completed by 200 adults disclosed 32% were unaware of the particular danger of UV light and only 3% knew that snow blindness, eclipse burns and cataracts could all be caused by sunlight. Fifty-four sunglasses were analysed for labelling and for transmission characteristics of their lenses. The standard of labelling of the sunglasses was poor with only 53% making reference to UV transmission characteristics and only three pairs stating that they adhered to the New Zealand Sunglass Standard. Attention is drawn to the need to improve public awareness of the potential for eye injury from sunlight and to improve the standard of labelling of sunglasses.

Adult↗

PubMed1989

Topical antibiotic prophylaxis for cataract surgery: a controlled trial of fusidic acid and chloramphenicol.

The effectiveness of topical fusidic acid 1%, in a viscous drop base, to reduce or eliminate ocular microflora in patients undergoing cataract surgery has been studied. Forty-two patients received fusidic acid on a double-blind basis and for comparison 21 patients were similarly assessed with topical chloramphenicol. A further 17 patients received no treatment other than subconjunctival cephazolin administered to all operated eyes at the time of surgery. Quantitative bacterial counts from the conjunctivae and lash lines of each patient were made 24 hours before surgery, on the morning of operation and again 48 hours after surgery. With a regimen of five administrations on the day prior to surgery, neither topical fusidic acid 1.0% nor chloramphenicol 0.5% produced clinically or statistically significant reductions of the ocular microflora. In contrast perioperative subconjunctival cephazolin effectively reduced or eliminated lid and conjunctival microflora following surgery. This study indicates that the effectiveness of a topical antibiotic preparation for overt ocular infection cannot be directly extrapolated to the effect on resident ocular microflora, at least with short-term use for presurgical prophylaxis.

Administration, Topical↗

PubMed1987

Ocular Toxocara canis infections: diagnosis by enzyme immunoassay.

An enzyme-linked immunoassay (ELISA) was used to establish the sero-prevalence of Toxocara canis infection in several New Zealand populations including those who, through environment or occupation, had close contact with dogs. The prevalence of positive ELISA values found reflected the degree of dog contact, e.g. positive ELISA's occurred in 2.8% of urban adults, 13.9% of dog breeders and 28.4% of hydatid control officers emphasizing that a history of dog contact needs to be considered when ELISA results are interpreted in a clinical context. Ophthalmoscopy of 102 hydatid officers, 28.4% of whom were seropositive, disclosed no evidence of ocular toxocariasis and suggested that the officers might be immunoprotected. Preliminary immunoblot analysis of the range of toxocara excretory/secretory antigens bound to serum immunoglobulin from patients with presumed visceral larva migrans and ocular toxocariasis, showed the same reactivity profile as a positive reference serum and serum from a seroresponsive hydatid control officer.

Adolescent↗

PubMed1987

Eye protectors for squash players.

Eye injuries have occurred to squash players wearing commercial open-type eyeguards, suggesting inadequacies in their design. This study reports experimental observations on the deformation of high velocity squash balls at an aperture simulating an open-type of eyeguard. Open eyeguards were shown to be inadequate in preventing eye trauma by ball-strike. Recommendations for improvement of eyeguard design have been made.

Athletic Injuries↗

PubMed1986

Retinopathy of prematurity: review of a five-year period, examination techniques and recommendations for screening.

The reported resurgence of retinopathy of prematurity prompted analysis of the prevalence of retinopathy among premature infants born at Christchurch Women's Hospital over a five-year period. Of the 129 surviving very-low-birthweight infants, 65 (50.4%) underwent ocular screening during the review period. Retinopathy was detected in 17.1% (22/129) of surviving infants, or 34% (22/65) of selected infants referred by paediatricians for ocular screening. Five infants had severe or blinding retinopathy and these premature infants were of significantly lower birthweight and born after shorter gestation periods than those found to have no retinopathy. Examination techniques for eyes of premature infants are discussed, and recommendations for screening for retinopathy of prematurity made.

Humans↗

PubMed1986

The relationship between toxocara ELISA absorbance values and toxocara ELISA titres: a comparative study.

Enzyme-linked immunosorbent assays (ELISAs) may be made by a variety of techniques at one or several serum dilutions which is very confusing for clinicians. This study compares the ELISA results from two centres on sera from 12 patients investigated for ocular toxocariasis by two common ELISA methods--the absorbance and titration techniques. With one exception, ELISA results by the two methods correlated well. For reasons outlined, the absorbance ELISA method is likely to remain the preferred method in New Zealand and Australia. Attention is drawn to the implications of the serum response to Toxocara canis larvae, and the need to evaluate ELISA results against clinical findings is emphasized.

Absorption↗

PubMed1985

Toxocaral infection in hydatid control officers: diagnosis by enzyme immunoassay.

An enzyme-linked immunosorbent assay for Toxocara canis larva excretory/secretory antigen has been set up in Christchurch. Employing this test, elevated specific antibody levels for toxocara larvae were found in 3.3% (3/90) of urban adult blood donors and 4.4% (4/90) of secondary school students. In comparison, elevated levels were present in 25.6% (23/90) of New Zealand hydatid control officers. It can be concluded from the present study that the higher risk of toxocariasis experienced by hydatid officers is reflected in elevated specific antibody titres in a significant proportion of individuals when compared with controls.

Adolescent↗

PubMed1979