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Biomedical subjects

K P West

Publications and source records attributed to K P West.

At least 19 recordsLinked to original sources
PubMed2004

Vitamin A deficiency as a preventable cause of maternal mortality in undernourished societies: plausibility and next steps.

Maternal vitamin A deficiency is a public health problem in the developing world. Recent evidence from Nepal suggests that supplementing populations of rural, poor, and undernourished women with a recommended dietary amount of vitamin A--or its equivalent as beta-carotene--can lower mortality risk related to pregnancy and childbirth, presumably by reducing the severity of conditions such as sepsis, tuberculosis, and diarrheal diseases. An adequate intake of beta-carotene may also reduce some maternal health risks related to oxidative stress. These findings reveal the potential for vitamin A and other micronutrient interventions to improve maternal and infant health and survival. They also present important implementation challenges for the developing world.

Developing Countries↗
PubMed2004

Cigarette smoking during pregnancy in rural Nepal. Risk factors and effects of beta-carotene and vitamin A supplementation.

OBJECTIVE: We examined risk factors of smoking and the association between smoking and pregnancy-related and 6-month infant mortality in rural Nepal, where 30% women reported smoking during pregnancy. DESIGN: Cross-sectional analysis of risk factors associated with smoking status and health consequences of smoking, using prospective data collected as part of a randomized community trial to examine the effect of maternal vitamin A or beta-carotene supplementation on maternal mortality. SETTING: Rural, southeastern plains of Nepal. SUBJECTS AND METHODS: A total of 17 767 women contributed at least one pregnancy during 3.5 y of the study. Data on cigarette or bidi (rolled tobacco) smoking were collected using a 7-day recall, twice during pregnancy. Associations between smoking status and maternal diet, morbidity profile, household socioeconomic status and serum concentration of retinol, carotenoids and tocopherols were examined. Further, relative risk (RR) and 95% confidence intervals (CI) were calculated to estimate supplement effects on pregnancy-related mortality, stratified by smoking status during pregnancy. RESULTS: Smokers were more likely to be older, illiterate and poor compared to nonsmokers. Fruit and vegetable consumption among smokers and nonsmokers did not vary. However, smokers were more likely to consume meat/fish/eggs and less likely to consume milk than nonsmokers. They were also more likely to report symptoms of vaginal bleeding, edema, severe headache and convulsions during pregnancy relative to nonsmokers. Mortality per 100,000 pregnancies appeared to be higher among smokers than nonsmokers in the placebo group (915 vs 584, RR=1.57, 95% CI: 0.80-3.08). beta-Carotene supplementation reduced pregnancy-related mortality both among smokers (RR=0.31 95% CI: 0.11-0.89) and nonsmokers (RR=0.41, 95% CI: 0.19-0.89). Similar results obtained with vitamin A supplementation were not statistically significant. Infant mortality up to 6 months was approximately 30% higher among smokers compared to nonsmokers in the placebo group both before and after adjusting for confounding factors. Neither supplement given to women reduced infant mortality. CONCLUSIONS: Cigarette smoking during pregnancy is associated with an increased risk of maternal and infant mortality in rural Nepal. beta-Carotene and to some extent vitamin A may reduce the risk of pregnancy-related mortality, but not infant mortality, among both smokers and nonsmokers.

Adult↗
PubMed2004

Complex interactions with infection and diet may explain seasonal growth responses to vitamin A in preschool aged Indonesian children.

OBJECTIVE: To explore the potential contribution of respiratory infections and vitamin A intakes to the seasonal effect of vitamin A supplementation on child growth. METHODS: Data from a randomized double-blind placebo-controlled trial, in which a single high dose of vitamin A or placebo was given every 4 months to 1405 children aged 6-48 months were used for the analysis. In total, 4430 child-treatment cycles were examined, and for each cycle the children had their dietary intake, weight, and height assessed at the start and end. Linear regression models of the difference in height and weight during each treatment cycle were used and the within-child correlation was adjusted using the generalized estimating equations (GEE). Other covariables in the model included age, sex, percentage of days with acute lower respiratory infection and diarrhea, and cumulative doses of vitamin A. RESULTS: This study showed that a significant effect of vitamin A supplementation on linear growth was observed in all seasons in children with a low burden of respiratory infections, that is, < 21.5% of days with respiratory illness. In each season, the highest effect was found in children with a low burden of respiratory infections and low vitamin A intakes, that is, intakes < 400 RE/day. Children with a high burden of respiratory infections or high vitamin A intakes benefited less from vitamin A supplementation for their linear growth than children with a low burden of respiratory infections and low vitamin A intakes. Finally, there was no benefit for linear growth from vitamin A supplementation in children with both a high burden of respiratory infections and high vitamin A intakes regardless of the season. CONCLUSIONS: The effect of vitamin A supplementation on growth is dependent on season. Respiratory infections and vitamin A intakes are important factors underlying the seasonal effect of vitamin A supplementation on growth.

Age Factors↗
PubMed2004

Vitamin A deficiency and xerophthalmia among school-aged children in Southeastern Asia.

OBJECTIVE: To determine provisional estimates of the extent of vitamin A (VA) deficiency and xerophthalmia among school-aged children. DESIGN: Literature search of published, unpublished and website-based population survey and study reports, with country-specific imputation of prevalence rates and numbers of children affected by: (1) VA deficiency based on measured or imputed distributions of serum retinol concentration < 0.70 micromol/l (equivalent to < 20 microg/dl) and (2) xerophthalmia, by country. SETTING: Countries within the WHO South-East Asian Region. SUBJECTS: The target group for estimation was children 5-15 y of age. INTERVENTIONS: None. RESULTS: The estimated prevalence of VA deficiency is 23.4%, suggesting that there are approximately 83 million VA-deficient school-aged children in the region, of whom 10.9% (9 million, at an overall prevalence of 2.6%) have mild xerophthalmia (night blindness or Bitot's spot). Potentially blinding corneal xerophthalmia appears to be negligible at this age. CONCLUSIONS: VA deficiency, including mild xerophthalmia, appears to affect large numbers of school-aged children in South-East Asia. However, nationally representative data on the prevalence, risk factors and health consequences of VA deficiency among school-aged children are lacking within the region and globally, representing a future public health research priority.

Adolescent↗
PubMed2004

A randomised trial of povidone-iodine to reduce visual impairment from corneal ulcers in rural Nepal.

AIM: To assess whether povidone-iodine provided any benefit over and above a standard regimen of antibiotic therapy for the treatment of corneal ulcers. METHODS: All patients diagnosed with corneal ulcers presenting for care at a primary eye care clinic in rural Nepal were randomised to a standard protocol of antibiotic therapy versus standard therapy plus 2.5% povidone-iodine every 2 hours for 2 weeks. The main outcomes were corrected visual acuity and presence, size, and position of corneal scarring in the affected eye at 2-4 months following treatment initiation. RESULTS: 358 patients were randomised and 81% were examined at follow up. The two groups were comparable before treatment. At follow up, 3.9% in the standard therapy and 6.9% in the povidone-iodine group had corrected visual acuity worse than 20/400 (relative risk (RR) 1.77, 95% confidence interval (CI) 0.62 to 5.03). 9.4% in the standard therapy and 13.1% in the povidone-iodine group had corrected visual acuity worse than 20/60 (RR 1.39, 95% CI 0.71 to 2.77), and 17.0% and 18.8% had scars in the visual axis in each of these groups, respectively (RR 1.11, 95% CI 0.67 to 1.82). CONCLUSIONS: A small proportion of patients with corneal ulceration treated in this setting had poor visual outcomes. The addition of povidone-iodine to standard antibiotic therapy did not improve visual outcomes, although this design was unable to assess whether povidone-iodine on its own would have resulted in comparable visual outcomes to that of standard therapy.

Adolescent↗
PubMed2003

Seasonality in urinary and household salt iodine content among pregnant and lactating women of the plains of Nepal.

OBJECTIVE: To determine the extent and causes of iodine deficiency among women during pregnancy and lactation in the southeastern plains of Nepal. DESIGN, SETTING AND SUBJECTS: Urinary iodine (UI) was assessed as an indicator of iodine status in spot urine samples of women participating in a field trial in three rural communities in the plains of southeastern Nepal. Samples were collected during pregnancy (n=1021) and during lactation at 3-4 months postpartum (n=1028) at a central clinic; 613 women were assessed at both times. Salt iodine (SI) content was assessed semiquantitatively at 6-7 months postpartum in households (n=1572). RESULTS: During pregnancy and lactation, median UI concentrations were 0.756 and 0.483 micromol/l, respectively, indicating mild iodine deficiency. UI and SI concentrations covaried markedly by season and were highest during hot, dry, premonsoon months and lowest during and following the humid monsoon season. Within women who contributed urine samples during both pregnancy and the postpartum period, iodine status determined by UI was not correlated. The percentage of households with adequately iodized salt (30 ppm) ranged from 85 to 44% from the hot, dry to the humid seasons, respectively. CONCLUSIONS: In the rural southern plains of Nepal, iodine deficiency remains a mild-to-moderate public health problem among pregnant and lactating women despite the availability of iodized salt. Marked seasonality in SI content may account for the lack of intraindividual correlation between maternal iodine status during pregnancy and postpartum periods and contribute to periodicity in the risk of iodine deficiency.

Adolescent↗
PubMed2003

An initiative to reform senior house officer training in histopathology.

Senior house officer schools in histopathology have been established in Leeds, Leicester and Southampton, each training six new recruits each year. Nine hours of protected teaching time is provided each week giving a ratio of apprenticeship learning to formal teaching of 3:1. Evaluations have been very positive. Much of this success is attributed to careful planning and adequate funding. This may be a useful model for other specialties to follow.

Attitude of Health Personnel↗
PubMed2002

Experimental study of large-volume microwave ablation in the liver.

BACKGROUND: Microwave coagulation therapy is useful in the destruction of small, irresectable liver tumours of primary and secondary origin. Unfortunately, the small lesion size produced by currently available equipment makes it difficult and time consuming completely to ablate lesions larger than 3 cm in diameter. A microwave system capable of producing large-volume ablations in very short periods of time has been developed. Using a large-animal model the ability of the equipment to produce large-volume lesions in a safe, predictable and dose-dependent manner was tested. METHODS: Fourteen large white pigs were anaesthetized and underwent multiple microwave treatments. The animals were killed at different timepoints to investigate lesion size and evolution. RESULTS: The microwave system was able to generate large-volume ablations of up to 6.5 cm in diameter in a controlled and dose-dependent manner. CONCLUSION: This novel microwave system allows the ablation of large volumes of liver tissue in a short period of time. The ability to produce lesions reproducibly and safely highlights the potential of this system in the future treatment of irresectable liver tumours.

Analysis of Variance↗
PubMed2002

Efficacy and one year follow up of argon plasma coagulation therapy for ablation of Barrett's oesophagus: factors determining persistence and recurrence of Barrett's epithelium.

INTRODUCTION: Barrett's epithelium (BE) has malignant potential. Neither acid suppression nor antireflux surgery produce consistent or complete regression of the metaplastic epithelium. Endoscopic thermoablation with argon plasma coagulation (APC) offers a different approach but factors influencing its outcome have not been systematically examined. AIM: To assess the efficacy of APC and factors influencing initial and one year outcome. METHODS: Fifty patients, mean age 61.4 years, mean BE length 5.9 cm (range 3-19), underwent APC therapy at four weekly intervals while receiving proton pump inhibitor (PPI) therapy. BE margins were marked by India ink tattooing and extent was documented by grid drawings, photography, and 2 cm interval quadrantic jumbo biopsies. Twenty four hour ambulatory oesophageal pH studies were done while on PPIs before and after APC therapy, and Bilitec bilirubin monitoring after APC completion. RESULTS: A total of 68% of patients achieved >90% BE ablation after a median of four APC sessions. Persistent BE (>10% original BE area) was associated with longer initial BE length despite more APC sessions. Persistent acid and bile reflux on PPIs, although commoner in this group, were not significantly different from those successfully ablated. Fifteen of 34 patients (44%) with successful macroscopic clearance had buried glands, present in 8.3% of a total of 338 biopsies. At the one year follow up, only 32% of those with initial successful ablation showed no recurrence. BE recurred or increased in most with mean segment length increases of 1.1 cm and 1.6 cm, respectively, in patients with previous full ablation and those with persistent BE. The presence of buried glands did not predict BE recurrence. Patients who reduced their PPI dose had significantly greater BE recurrence. CONCLUSIONS: APC is most effective for shorter segment BE ablation but "buried" glands do occur. Recurrence of BE is common at one year, especially in those with initial persistent and/or long segment BE and those who reduce their PPI dose.

Adult↗
PubMed2001

Comparison of visual estimates of children's portion sizes under both shared-plate and individual-plate conditions.

OBJECTIVE: This paper compares the accuracy of visual estimations of children's food intake in settings where several children eat together off 1 plate vs individual-plate eating scenarios. DESIGN: Eight trained observers were tested in their ability to estimate food portions consumed by children enacting common eating scenarios. Foods were categorized by food group and according to their presentation by individual-plate and shared-plate. Observed food weight estimates were compared to actual weights. SUBJECTS/SETTING: The 8 observers visually estimated 69 food portions of children eating alone and 26 portions where children were eating from a shared plate. This study was carried out in Sarlahi District, a rural, central lowland region of Nepal. STATISTICAL ANALYSES: Pearson's correlation coefficients were calculated to examine associations between estimated and actual weights. A fixed effects model was constructed to compare observers. RESULTS: Analyses revealed that observer estimates of food weights under field conditions were well correlated with actual weights for individual-plate (r = 0.89) and for shared-plate (r = 0.84) scenarios. Observers estimated food weights when children ate together on a shared plate less accurately than they did in settings where children ate alone. With the exception of 1 observer, observers did not differ significantly in their ability to estimate food weights. Accuracy of estimations was influenced by food weight with greater error associated with food quantities of less than 70 g. CONCLUSIONS: Visual estimation is a relatively accurate, valid method of assessing child food intake under rural field conditions, and the only method to obtain accurate information on dietary intake in regions where shared-plate eating is frequent.

Child↗
PubMed2001

Circulating levels of retinol, tocopherol and carotenoid in Nepali pregnant and postpartum women following long-term beta-carotene and vitamin A supplementation.

OBJECTIVE: To characterize circulating carotenoid and tocopherol levels in Nepali women during pregnancy and post-partum and to determine the effects of beta-carotene and vitamin A supplementation on their concentration in serum. DESIGN: Randomized community supplementation trial. SETTING: The study was carried out from 1994 to 1997 in the Southern, rural plains District of Sarlahi, Nepal. SUBJECTS: A total of 1431 married women had an ascertained pregnancy, of whom 1186 (83%) provided an analyzable serum sample during pregnancy; 1098 (77%) provided an analyzable 3-4 months post-partum serum sample. INTERVENTIONS: Women received a weekly dose of vitamin A (7000 microg RE), beta-carotene (42 mg) or placebo before, during and after pregnancy. Serum was analyzed for retinol, alpha-tocopherol, gamma-tocopherol, beta-carotene, alpha-carotene, lycopene, lutein + zeaxanthin, and beta-cryptoxanthin concentrations during mid-pregnancy and at approximately 3 months post-partum. RESULTS: Compared to placebo, serum retinol, beta-carotene, gamma-tocopherol, beta-cryptoxanthin and lutein + zeaxanthin concentrations were higher among beta-carotene recipients during pregnancy and, except for beta-cryptoxanthin, at postpartum. In the vitamin A group, serum retinol and beta-cryptoxanthin were higher during pregnancy, and retinol and gamma-tocopherol higher at postpartum. Lutein + zeaxanthin was the dominant carotenoid, regardless of treatment group, followed by serum beta-carotene. Serum lycopene level was lowest, and very low compared to the US population. Serum retinol was higher, and carotenoid and alpha-tocopherol lower, at postpartum than during pregnancy in all groups. CONCLUSIONS: Pregnant and lactating Nepali women have lower serum carotenoid and tocopherol levels than well-nourished populations. beta-carotene supplementation appeared to increase levels of tocopherol and other carotenoids in this population.

Adult↗
PubMed2001

Zinc supplementation might potentiate the effect of vitamin A in restoring night vision in pregnant Nepalese women.

BACKGROUND: Zinc deficiency may result in abnormal dark adaptation or night blindness, a symptom primarily of vitamin A deficiency. During a placebo-controlled trial in Nepal, weekly vitamin A supplementation of women reduced but failed to eliminate the incidence of night blindness during pregnancy, suggesting a role for zinc. OBJECTIVE: The study examined the efficacy of daily zinc supplementation in restoring night vision of pregnant women who developed night blindness while routinely receiving either vitamin A, beta-carotene, or placebo in a field trial. DESIGN: Women (n = 202) who reported to be night blind during pregnancy were randomly assigned in a double-blind manner, stratified on vitamin A, beta-carotene, or placebo receipt, to receive 25 mg Zn or placebo daily for 3 wk. Thus, the 6 groups studied were as follows: beta-carotene + zinc, beta-carotene alone, vitamin A + zinc, vitamin A alone (vitamin A + placebo), zinc alone (zinc + placebo), and placebo (2 placebos: one for the vitamin A or beta-carotene study and one for the zinc study). Women underwent a clinic-based assessment that included pupillary threshold testing and phlebotomy before and after supplementation. Supplement use and daily history of night blindness were obtained at home twice every week. RESULTS: Zinc treatment increased serum zinc concentrations, but alone (zinc alone group), failed to restore night vision or to improve dark adaptation. However, women in the vitamin A + zinc group who had baseline serum zinc concentrations <9.9 micromol/L were 4 times more likely to have their night vision restored (95% CI: 1.1, 17.3) than were women in the placebo group and tended to have a small improvement in pupillary threshold scores (by 0.21 log candela/m2; P = 0.09). CONCLUSION: These data suggest that zinc potentiated the effect of vitamin A in restoring night vision among night-blind pregnant women with low initial serum zinc concentrations.

Adult↗
PubMed2001

Twinning rates and survival of twins in rural Nepal.

BACKGROUND: Twin pregnancies are common but there are few data on rates of twinning or survival of liveborn twin infants in developing countries. METHODS: The rates of multiple births were calculated in a population-based cohort of married women of childbearing age who were enrolled in a randomized community trial to assess the impact of vitamin A or beta-carotene on maternal and infant health and survival. RESULTS: The rate of twinning was 16.1 per 1000 pregnancies (7.4 if only twin pregnancies resulting in two liveborn infants were used). The rate for triplets and quadruplets was 0.19 and 0.06 per 1000 pregnancies. Twinning rates were higher among women of higher parity, but were not associated with maternal age. Twinning rates among twins where at least one was live born (or increased in utero survival) were 30% (95% CI : -1%, 71%) and 44% (95% CI : 9%, 89%) higher among women receiving vitamin A and beta-carotene supplements than placebo, after adjusting for maternal age, gestational age, and parity. The perinatal mortality rate was 8.54 times higher for twins than singletons, 7.32 higher for neonatal mortality, and 5.84 higher for cumulative 24-week mortality. This difference was reduced but not erased by adjusting for gestational age. No difference in survival of liveborn twin infants was seen by supplement group. A higher mortality rate among male twins was largely explained by gestational age. CONCLUSIONS: Multiple births are relatively common occurrences in rural Nepal, and carry a much higher mortality risk for the infants than for singletons. Vitamin A or beta-carotene supplementation appeared to increase the rate of twinning, or improve the survival of twins in utero, but did not increase twin survival after birth.

Adult↗
PubMed2001

Maternal night blindness increases risk of mortality in the first 6 months of life among infants in Nepal.

Night blindness occurs commonly among women during pregnancy in rural NEPAL: We examined the relationship between maternal night blindness and the risk of mortality occurring among infants in the first 6 mo of life. Stratified analysis by maternal night blindness status during pregnancy was done for 10,000 women participating in a randomized, placebo-controlled trial of vitamin A and beta-carotene supplementation. Mortality of infants of non-night blind women in all three supplementation groups was similar, and when combined, was 63/1000 live births. Relative to this, mortality was higher by 63% [95% confidence interval (CI): 9-138%) and 50% (95% CI: -3 to 133%) among infants of night blind women receiving placebo and beta-carotene, respectively, but only by 14% (95% CI: -33 to 93%) among those receiving vitamin A. Thus, 6-mo mortality was higher among infants of women who had night blindness during pregnancy. Maternal receipt of vitamin A reduced this risk.

Female↗
PubMed2001

University of Kentucky community-based field experience: program description.

Community-based field experiences (CBFE) provide students with exemplary experiential learning opportunities. The purposes of this paper are to describe the University of Kentucky College of Dentistry (UKCD) CBFE and report the results of a two-year, self-report survey that assessed the primary course goal, students' perceptions of change in knowledge and skills related to nineteen areas of patient care (n = 90, 100% return rate), and their overall rating of the program. Knowledge and skill data were analyzed using the non-parametric binomial test for comparing proportions. A significant (.05 level) majority of students reported increases in knowledge in all areas to which they were exposed. Descriptive frequencies summarizing the results of the total CBFE experience indicate that the majority of students felt it was a positive experience. The CBFE continues to be a meaningful element in the UKCD curriculum as it provides students with a relevant, authentic educational experience.

Community Dentistry↗
PubMed2000

Night blindness during pregnancy and subsequent mortality among women in Nepal: effects of vitamin A and beta-carotene supplementation.

Night blindness due to vitamin A deficiency is common during pregnancy among women in Nepal. The authors assessed the risk of maternal death during and after a pregnancy with night blindness among women participating in a cluster-randomized, placebo-controlled vitamin A and beta-carotene supplementation trial in Nepal from July 1994 to September 1997. Subjects were 877 women with night blindness and 9,545 women without night blindness during pregnancy. Women were followed from the time they declared that they were pregnant through the end of the study, representing a median follow-up of 90 weeks (interquartile range: 64-121 weeks). Mortality of night-blind women in the placebo group was 3,601 per 100,000 pregnancies. In comparison, the relative risk of dying among nonnight-blind women in the placebo group was 0.26 (95% confidence interval (CI): 0.13, 0.55), and the relative risk among women with or without night blindness in the vitamin A/beta-carotene group was 0.32 (95% CI: 0.10, 0.91) and 0.18 (95% CI: 0.09, 0.36), respectively. Night-blind women were five times (95% CI: 2.20, 10.58) more likely to die from infections than were women who were not night blind. These findings show that night blindness during pregnancy is a risk factor of both short- and long-term mortality among women. Vitamin A/beta-carotene supplementation ameliorates this risk to a large extent.

Adolescent↗