5 research outputs found
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Plasma carotenoids and retinol and dietary intake : association with in situ and invasive cervical carcinomas in Bangkok, Thailand
There is a strong evidence that human papillomavirus (HPV) is the key causative agent of cervical cancer. However, the majority of women who are exposed to the oncogenic HPV do not develop invasive cervical cancer, suggesting that other factors could play a role in the cause and progression of cervical cancer. Epidemiological studies have suggested carotenoids and retinol as possible risk co-factors in cervical cancer etiology. However, the evidence is not conclusive. The study was design to achieve five objectives: 1) to validate the food frequency questionnaire (FFQ) used in a case-control study in Bangkok, Thailand; 2) to examine the association of individual plasma carotenoids and retinol with the risk of in situ cervical carcinoma; 3) to examine association of individual plasma carotenoids and retinol with the risk of invasive cervical carcinoma; 4) to investigate the association between individual plasma carotenoids and retinol and the risk of progression from in situ carcinoma to invasive disease; 5) to investigate the association between concordant quartiles of the β-carotene as measured from plasma and dietary intake with risk of invasive cervical cancer. The FFQ measures reflect longer-term usual intake while plasma carotenoid measures reflect recent intake.
Included in the study were 50 in situ cases with abnormal Pap smears and pre-admission diagnosis of carcinomas in situ and 103 clinic controls with normal Pap smear test. Also included in the study were 201 invasive cases with histologically confirmed invasive cervical carcinoma and 302 hospital controls admitted to Siriraj Hospital with other unrelated diseases to cervical cancer. Plasma carotenoids and retinol were measured by high performance liquid chromatography (HPLC). Human papillomavirus infection was detected using a standard PCR-based test. Food frequency questionnaire (FFQ) was used to capture the intake of the β-carotene.
Results showed that:
1. After adjusting for age and body mass index (BMI), selected plasma carotenoids were moderately correlated with fruits and vegetable intake as well as nutrient intake.
2. In the age-adjusted and multivariate logistic regression models we found no significant associations between any of the plasma measures (carotenoid and retinol) and either risk of in situ or invasive disease as compared to controls or for in situ carcinomas versus invasive disease, a measure of disease progression.
3. Women high in both measures of exposure (dietary and plasma) for β-carotene were at significantly reduced risk of invasive cervical cancer after confounders were adjusted for in the multivariate logistic regression.
4. Women high on dietary intake and low on plasma for β-carotene were also at the lowest risk of invasive cervical cancer after adjusting for confounders.
Based on the results above, the study suggests that the FFQ used in Bangkok, Thailand is an acceptable tool for long-term dietary intake assessment. However, an additional validation study is warranted using large a sample size and participants that are more representative of the general population in Thailand. Furthermore, this study does not support the possibility of individual carotenoids and retinol as risk factors for in situ and invasive cervical carcinomas as well as the progression of cervical cancer to invasive disease. Lastly, the study suggests that long-term increased consumption of fruits and vegetables may provide some protection in women in Thailand from having invasive cervical cancer. However, additional research is needed to support this finding from our study
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Determination of vitamin B-6 and pyridoxine-glucoside in selected Malawi foods and the effect of preparation techniques on vitamin B-6 and pyridoxine-glucoside content
There were two main purposes to this study. The first was to determine the vitamin B-6 and pyridoxine β-glucoside content of selected foods commonly consumed in Malawi. The second was to examine the effect of preparation procedures of foods in Malawi on the content of vitamin B-6 and pyridoxine β- glucoside in foods. Seventeen plant foods commonly eaten in Malawi were determined for vitamin B-6 and pyridoxine β-glucoside using a microbiological assay. In addition, two commercial weaning foods, roasted maize-soy bean blend and extruded maize-soy bean blend, were also determined for vitamin B-6 and pyridoxine β-glucoside contents. Among all the foods analyzed, whole maize flour contained the highest amount of vitamin B-6 (0.66 mg/100 g), therefore, an excellent source of vitamin B-6 content in foods. Cooking decreased vitamin B-6 in pinto beans, kidney beans, sugar beans and cow peas by 34%, 45%, 14% and 48%, respectively. Roasting decreased vitamin B-6 in chick peas and soy beans by 59% and 38%, respectively. Soaking and fermentation reduced vitamin B-6 in soaked maize flour and cassava flour by 86% and 89 %, respectively. Therefore, these data suggest that some of the preparation procedures practiced in Malawi have a negative impact on the vitamin B-6 content of the processed foods. Cooked and roasted foods contained lower total amount of pyridoxine-glucoside than that of the raw food. The high pyridoxine β-glucoside content have adverse impact on the bioavailability of vitamin B-6 content. Based on typical diets for the urban and rural populations in Malawi, the rural diet contained less vitamin B-6 compared to that of urban diet. Therefore, the rural population may be at risk of inadequate vitamin B-6 intake compared to the urban population
Testing a global standard for quantifying species recovery and assessing conservation impact.
Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a "Green List of Species" (now the IUCN Green Status of Species). A draft Green Status framework for assessing species' progress toward recovery, published in 2018, proposed 2 separate but interlinked components: a standardized method (i.e., measurement against benchmarks of species' viability, functionality, and preimpact distribution) to determine current species recovery status (herein species recovery score) and application of that method to estimate past and potential future impacts of conservation based on 4 metrics (conservation legacy, conservation dependence, conservation gain, and recovery potential). We tested the framework with 181 species representing diverse taxa, life histories, biomes, and IUCN Red List categories (extinction risk). Based on the observed distribution of species' recovery scores, we propose the following species recovery categories: fully recovered, slightly depleted, moderately depleted, largely depleted, critically depleted, extinct in the wild, and indeterminate. Fifty-nine percent of tested species were considered largely or critically depleted. Although there was a negative relationship between extinction risk and species recovery score, variation was considerable. Some species in lower risk categories were assessed as farther from recovery than those at higher risk. This emphasizes that species recovery is conceptually different from extinction risk and reinforces the utility of the IUCN Green Status of Species to more fully understand species conservation status. Although extinction risk did not predict conservation legacy, conservation dependence, or conservation gain, it was positively correlated with recovery potential. Only 1.7% of tested species were categorized as zero across all 4 of these conservation impact metrics, indicating that conservation has, or will, play a role in improving or maintaining species status for the vast majority of these species. Based on our results, we devised an updated assessment framework that introduces the option of using a dynamic baseline to assess future impacts of conservation over the short term to avoid misleading results which were generated in a small number of cases, and redefines short term as 10 years to better align with conservation planning. These changes are reflected in the IUCN Green Status of Species Standard