212 research outputs found
Epidemiological studies of parasitic gastrointestinal nematodes, cestodes and coccidia infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe
Between January 1999 and December 2000 faecal samples from 16 264 cattle at 12 dipping sites in the highveld and nine in the lowveld communal grazing areas of Zimbabwe were examined for gastrointestinal (GI) nematode and cestodes eggs, and coccidia oocysts. Strongyle larvae were identified following culture of pooled faecal samples collected at monthly intervals. The effects of region, age, sex and season on the prevalence of GI nematodes, cestodes and coccidia were determined. Faecal egg and oocyst counts showed an overall prevalence of GI nematodes of 43 %, coccidia 19.8 % and cestodes 4.8 %. A significantly higher prevalence of infection with GI nematodes, cestodes and coccidia was recorded in calves (P < 0.01) than in adults. Pregnant and lactating cows had significantly higher prevalences than bulls, oxen and non-lactating (dry cows) (P < 0.01). The general trend of eggs per gram (epg) of faeces and oocysts per gram (opg) of faeces was associated with the rainfall pattern in the two regions, with high epg and opg being recorded during the wet months. The most prevalent genera of GI nematodes were Cooperia, Haemonchus and Trichostrongylus in that order. Strongyloides papillosus was found exclusively in calves. Haemonchus was significantly more prevalent during the wet season than the dry season (P < 0.01). In contrast, Trichostrongylus was present in significantly (P < 0.01) higher numbers during the dry months than the wet months, while Cooperia and Oesophagostomum revealed no significant differences between the wet and dry season. These findings are discussed with reference to their relevance for strategic control of GI parasites in cattle in communal grazing areas of Zimbabwe
Tryptophan catabolites as metabolic markers of vitamin B-6 status evaluated in cohorts of healthy adults and cardiovascular patients
Background
Vitamin B-6 status is routinely measured as pyridoxal 5′-phosphate (PLP) in plasma. Low concentrations of PLP are associated with rheumatic, cardiovascular, and neoplastic diseases. We have previously shown that vitamin B-6 status affects the kynurenine (Kyn) pathway of tryptophan (Trp) catabolism.
Objective
This study aimed to comprehensively evaluate the use of Kyns as potential markers of functional vitamin B-6 status across 2 large cohorts.
Methods
We measured circulating concentrations of the first 6 metabolites in the Trp catabolic pathway by LC–MS-MS in the community-based Hordaland Health Study (HUSK; n = 7017) and cardiovascular patient–based Western Norway Coronary Angiography Cohort (WECAC; n = 4161). Cross-sectional and longitudinal associations of plasma PLP with Kyns were estimated using linear and nonlinear regression–based methods.
Results
3′-Hydroxykynurenine (HK), a substrate, and all 4 products formed directly by the PLP-dependent enzymes kynurenine transaminase and kynureninase contributed to the explanation of circulating PLP in multivariable-adjusted regression models. The construct HK:(kynurenic acid + xanthurenic acid + 3′-hydroxyanthranilic acid + anthranilic acid), termed HK ratio (HKr), was related to plasma PLP with standardized regression coefficients (95% CIs) of −0.47 (−0.49, −0.45) and −0.46 (−0.49, −0.43) in HUSK and WECAC, respectively. Across strata of cohort and sex, HKr was 1.3- to 2.7-fold more sensitive, but also 1.7- to 2.9-fold more specific to changes in PLP than a previously proposed marker, HK:xanthurenic acid. Notably, the association was strongest at PLP concentrations < ∼20 nmol/L, a recognized threshold for vitamin B-6 deficiency. Finally, PLP and HKr demonstrated highly sex-specific and corroborating associations with age.
Conclusions
The results demonstrate that by combining 5 metabolites in the Kyn pathway into a simple index, HKr, a sensitive and specific indicator of intracellular vitamin B-6 status is obtained. The data also underscore the merit of evaluating alterations in Kyn metabolism when investigating vitamin B-6 and health.acceptedVersio
Inflammation, sex, blood pressure changes and hypertension in midlife: the Hordaland Health Study
Our aim was to test sex-specific associations of circulating markers of inflammation with blood pressure (BP) and incident hypertension in midlife. Participants in the Hordaland Health study (n = 3280, 56% women, mean age 48 years) were examined at baseline and followed for 6 years. Circulating levels of inflammatory markers including high-sensitive C-reactive protein (hs-CRP), neopterin, and pyridoxic acid ratio (PAr) index were measured at follow-up. The associations with systolic/diastolic BP and incident hypertension were tested in sex-specific linear- or logistic-regression analyses adjusted for body mass index, serum triglycerides, creatinine, physical activity, smoking and diabetes. At follow-up, women had lower mean BP than men (124/72 vs. 130/78 mmHg, p < 0.001). Higher hs-CRP was significantly associated with greater systolic and diastolic BP (standardized β = 0.07 and β = 0.09, both p < 0.01) in women, but not in men. Higher neopterin was associated with higher diastolic BP in women and higher PAr index was associated with higher diastolic BP in women and higher systolic and diastolic BP in men (all p < 0.01). Compared to hs-CRP < 1 mg/l, higher levels of hs-CRP 1–<3 mg/l and hs-CRP ≥ 3 mg/l were associated with new-onset hypertension only in women (odds ratio (OR) 1.74, 95% CI 1.20–2.53 and OR 1.87, 95% CI 1.20–2.90). Sex-interactions were found for hs-CRP and neopterin in models on incident hypertension and diastolic BP, respectively (both p < 0.05). Higher levels of circulating markers of inflammation were associated with higher BP and incident hypertension in a sex-specific manner. Our results suggest a sex-specific interaction between cardiovascular inflammation and BP in midlife.publishedVersio
Spatial Clustering of Porcine Cysticercosis in Mbulu District, Northern Tanzania
Taenia solium is a tapeworm that causes two different disease conditions. In its adult stage, it inhabits the small intestine of human, a condition known as taeniosis, which is characterised by mild symptoms including abdominal disconfort. In the larval stage, T. solium can infect humans and various animal species, mainly pigs, causing cysticercosis. Taeniosis is acquired through consumption of inadequately cooked infected meat, while cysticercosis is acquired through ingestion of tapeworm eggs in foodstuffs contaminated with faeces from a human tapeworm carrier. Cysticercosis of human central nervous tissues (neurocysticercosis) causes serious syndromes such as epilepsy. Transmission of T. solium is facilitated by several factors such as presence of tapeworm carriers, poor sanitation and poor pig husbandry, which allow pigs to access human faeces. Nevertheless, the role of these factors in parasite transmission may vary with different cultural settings. Following an incidence and a prevalence studies in a rural area of northern Tanzania, there was a significant spatial clustering of porcine cysticerocis, suggesting focal distribution of transmission risk factors, which could be targeted for interventions. The study also revealed that despite the low sensitivity of the lingual examination method to detect porcine cysticercosis, it could highlight the potential ‘hotspots’ of the infection
Exploratory analyses on the effect of time since last meal on concentrations of amino acids, lipids, one-carbon metabolites, and vitamins in the Hordaland Health Study
Purpose
Dietary intake may have pronounced effects on circulating biomarker concentrations. Therefore, the aim was to provide a descriptive overview of serum metabolite concentrations in relation to time since last meal, focusing on amino acids, lipids, one-carbon metabolites, and biomarkers of vitamin status.
Methods
We used baseline data from the observational community-based Hordaland Health Study, including 2960 participants aged 46–49 years and 2874 participants aged 70–74 years. A single blood draw was taken from each participant, and time since last meal varied. Estimated marginal geometric mean metabolite concentrations were plotted as a function of time since last meal, up to 7 h, adjusted for age, sex, and BMI.
Results
We observed a common pattern for nearly all amino acids and one-carbon metabolites with highest concentrations during the first 3 h after dietary intake. Homocysteine and cysteine were lowest the 1st hour after a meal, while no patterns were observed for glutamate and glutamic acid. The concentrations of phylloquinone and triglycerides were highest 1 h after dietary intake. Thiamine and thiamine monophosphate concentrations were highest, while flavin mononucleotide concentrations were lowest within the first 2 h after a meal. No clear patterns emerged for the other fat-soluble vitamins, blood lipids, or B-vitamin biomarkers.
Conclusion
Our findings suggest that distinguishing between “fasting” and “non-fasting” blood samples may be inadequate, and a more granular approach is warranted. This may have implications for how to account for dietary intake when blood sampling in both clinical and research settings.publishedVersio
Smoking, plasma cotinine and risk of atrial fibrillation: the Hordaland Health Study
Background: Cigarette smoking has been identified as a major modifiable risk factor for coronary heart disease and mortality. However, findings on the relationship between smoking and atrial fibrillation (AF) have been inconsistent. Furthermore, findings from previous studies were based on self‐reported smoking. Objective: To examine the associations of smoking status and plasma cotinine levels, a marker of nicotine exposure, with risk of incident AF in the Hordaland Health Study. Methods: We conducted a prospective analysis of 6682 adults aged 46‐74 years without known AF at baseline. Participants were followed via linkage to the Cardiovascular Disease in Norway (CVDNOR) project and the Cause of Death Registry. Smoking status was assessed by both questionnaire and plasma cotinine levels. Results: A total of 538 participants developed AF over a median follow‐up period of 11 years. Using questionnaire data, current smoking (HR: 1.41, 95% CI: 1.09–1.83), but not former smoking (HR: 1.03, 95% CI: 0.83–1.28), was associated with an increased risk of AF after adjustment for gender, age, body mass index, hypertension, physical activity and education. Using plasma cotinine only, the adjusted HR (95% CI) was 1.40 (1.12–1.75) for participants with cotinine ≥85 nmol L−1 compared to those with cotinine <85 nmol L−1. However, the risk increased with elevated plasma cotinine levels until 1199 nmol L−1 (HR: 1.55, 95% CI: 1.16–2.05 at the third group vs. the reference group) and plateaued at higher levels. Conclusions: Current, but not former smokers, had a higher risk of developing AF. Use of plasma cotinine measurement corroborated this finding.publishedVersio
Coherent pion production in neutrino nucleus collision in the 1 GeV region
We calculate cross sections for coherent pion production in nuclei induced by
neutrinos and antineutrinos of the electron and muon type. The analogies and
differences between this process and the related ones of coherent pion
production induced by photons, or the (p,n) and reactions are
discussed. The process is one of the several ones occurring for intermediate
energy neutrinos, to be considered when detecting atmospheric neutrinos. For
this purpose the results shown here can be easily extrapolated to other
energies and other nuclei.Comment: 13 pages, LaTex, 8 post-script figures available at
[email protected]
Secular changes in dementia risk indices among 70-year-olds: a comparison of two Finnish cohorts born 20 years apart
AimsTo compare dementia risk indices among two separate cohorts of 70-year-olds born 20 year apart.MethodsCommunity-dwelling 70-year-old Finns were examined with similar examinations in 1991 (n = 1032) and in 2011 (n = 960). Dementia risk was assessed with the CAIDE Dementia Risk Score (CAIDE) (n = 1516), the Brief Dementia Risk Index (BDRI) (n = 1598) and the Dementia Screening Indicator (DSI) (n = 1462).ResultsThe proportion of subjects with moderate or high risk for dementia was significantly higher in earlier than in later born cohort according to CAIDE (99% and 94%, respectively, p ConclusionsAccording to dementia risk indices, it seems that dementia risk has decreased among community-dwelling 70-year-old subjects during the last decades in Finland.</p
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