Properties of retinyl ester hydrolase activity in pig and rat liver

Hydrolysis of vitamin A esters by liver is important during their uptake as part of chylomicron remnants and for their mobilization from storage in vitamin A-containing globules. The regulation and properties of the enzyme thought to catalyze these reactions, retinyl ester hydrolase (REH), were studied by the use of a sensitive in vitro assay developed for this enzyme in pig and rat liver. Hydrolysis of retinyl palmitate was maximal in 3- (3-cholamidopropyl) dimethylammonio -1-propanesulfonate (CHAPS) and Triton X-100, and the production of retinol was quantified by HPLC;Regulation of hepatic REH was studied by determining the relationship between its activity and physiological indicators of vitamin A nutritional status. Maximally stimulated hydrolase activity was not strongly influenced by serum or liver vitamin A concentrations in rats or pigs. However, in reduced detergent and substrate concentrations, REH activity was 3-fold higher (p \u3c 0.01) in rats with depleted liver reserves (\u3c10 (mu)g/g). Thus, REH may play a role in the homeostatically controlled release of vitamin A from liver, by mechanisms that are masked in vitro by concentrated detergent;Bile salts also strongly affected the level and interanimal variability of REH activity. Notably, rat REH activity in individual livers was 10-fold higher in CHAPS compared to sodium cholate, and less variable (5- compared to 37-fold). Therefore, the variability others have reported may be due to the use of sodium cholate to stimulate REH;13-cis, 9-cis and 9,13-cis Retinyl palmitate were excellent substrates for pig liver REH, being hydrolyzed at rates 2- to 7-times greater than the all-trans isomer with similar apparent K(,m) values and pH dependencies. However, by salt fractionation and column chromatography, three enzyme preparations were separated, which differed in their sensitivities to inhibitors and in their detergent-dependent substrate specificities. Thus, retinyl ester hydrolysis in the liver may well involve more than one enzyme

Distribution of Common Raccoons and Coyotes During Quail Nesting Season

Mammalian predation of quail and their eggs is a problem to many producers of quail particularly considering that abundance of common meso-predators, such as coyotes (Canis latrans) and common raccoons (Procyon lotor), is increasing. Predator removal programs are often not cost effective in increasing quail numbers but habitat management may be appropriate. There is a need for detailed knowledge of the habitat preferences and foraging patterns of these predators so producers of quail may limit predation of quail through management decisions and habitat manipulation. We placed GPS collars on 5 coyotes and 11 raccoons at Rolling Plains Quail Research Ranch, Fisher County, Texas during the nesting season of northern bobwhites (Colinus virginianus). The location of each animal was recorded at 5-min intervals for 35–42 consecutive nights. Habitat use and selectivity was calculated by Chi-square test of proportional use and availability of ecological sites both within the minimum convex polygon area used by each animal and throughout the ranch and adjacent 3-km buffer zone. Distribution of marked animals relative to roads, water, and quail feeders was compared to an equal number of randomly generated locations. Coyotes preferentially hunted in grassland which is prime nesting habitat for northern bobwhites. Coyotes were not deterred from accessing grassland with high concentrations of low growing plains prickly pear (Opuntia polyacantha). The nocturnal paths taken by coyotes over 1 month effectively covered virtually all the grassland habitat within their home range which increases the probability of locating nesting quail. Coyotes used ranch roads for travel but had little attraction to quail feeders and water sources. Raccoons favored areas of heavy cover such as riparian woodland and boulder strewn hillsides. Female raccoons had small home ranges and remained within thick cover. They rarely entered the more open habitats where quail nest and did not use ranch roads or seek out quail feeders which were mainly in grassland areas, nor did they encounter cactus-dominated grassland areas. Male raccoons had more expansive home ranges than females; they favored riparian strips and rocky hills as travel corridors but also ventured into more open habitats. They strongly avoided cactus-dominated areas but used grassland where scattered shrubs provided additional cover. Male raccoons within these areas used ranch roads for ease of travel and certain individuals frequently visited quail feeding stations. The tortuous nocturnal foraging path followed by raccoons provided efficient search patterns for locating scattered resources such as quail nests. Raccoons are generally considered to be more problematic predators of quail nests than coyotes. Where coyotes are less of a threat to quail than raccoons, tolerating the presence of coyotes may protect quail through competitive exclusion of raccoons from grasslands by the larger predator. Similarly, cactus in grasslands is seen as a problem for grazing livestock and a hindrance to quail hunters, but leaving some areas dominated by cactus may provide quail with valuable nesting refugia inaccessible to raccoons. The success of supplemental feed programs for quail should be balanced against the problem of altering the distribution of raccoons so they spend more time in quail nesting habitat and are more likely to discover quail nests. Placing feeders in areas where cover for predators is limited is advisable, as is targeted predator removal at quail feeding stations

Oral Disease Bacterium Linked to Alzheimer’s disease

This review proposes an association between the bacteria found in periodontal disease and the development of neural plaque contributing to Alzheimer’s disease. Periodontitis is a chronic gum disease that destroys gingiva and jawbone. Many different species of bacteria are found in periodontitis such as Porphyromonas gingivalis, an anaerobic gram-negative bacterium. Recent studies have shown P. gingivalis is capable of entering the bloodstream and affecting both the brain and organ systems within a human host. In this review, I will delve into the anatomy of the human mouth, explain the cause and effects of both periodontal and Alzheimer’s diseases, and attempt to explicate the relationship between periodontitis and Alzheimer’s disease. I suggest a direct correlation between the bacteria present in periodontitis and the human brain impacted by Alzheimer’s disease. In support of my hypothesis, I reference peer reviewed works and a published study detecting P. gingival in the cortex region of the brain. Additionally, in this paper, I hope to provide a clear correlation between the progression of gum disease and the onset of Alzheimer’s disease. The proposed link between P. gingival and Alzheimer’s disease suggest a new avenue of preventative treatment along with signs of early diagnosis

The Prevalence and Factors Associated with Knee Pain in a sample of Cyclists within the United Kingdom: A Cross Sectional Study

Purpose: The study aimed to determine: (i) the lifetime and period prevalence of knee pain, (ii) the prevalence and nature of medical attention cycling-related injuries, (iii) and the risk factors associated with knee pain and in a sample of competitive and non-competitive cyclists in the UK. Methods: A cross-sectional questionnaire was used to collect data on knee pain, medical attention injuries, and potential risk factors associated with knee pain. Participants were competitive and non-competitive cyclists aged 18 years and older and were recruited through cycling clubs and online advertisement. Binary logistic regression was used to assess for potential risk factors associated with knee pain. Crude and adjusted odds ratios were reported in staged adjustment models, controlling for potential confounders of age and sex. Keele University Ethics Committee approved this study. Results: A total of 115 respondents completed the questionnaire. Lifetime knee pain prevalence was 48%, with period prevalence 26.1% (past-month) and 18.3% (past-week). Aged 40 and over was the only factor found to be associated with knee pain, although this was no longer significant after adjustment for female sex. The most prevalent site and type of injury was the lower back and fracture (traumatic), respectively. Conclusion: Knee pain prevalence is high in this sample of cyclists, particularly in those aged 40 years and over. Injury prevention strategies should target the lower back and fractures. Longitudinal research is needed to identify if there are modifiable risk factors that may reduce the occurrence of both knee pain and traumatic fractures in cyclists

Elemental abundances in the silicate phase of pallasitic meteorites

The silicate phases of 11 pallasites were analyzed instrumentally to determine the concentrations of some major, minor, and trace elements. The silicate phases were found to contain about 98% olivine with 1 to 2% accessory minerals such as lawrencite, schreibersite, troilite, chromite, and farringtonite present. The trace element concentrations, except Sc and Mn, were found to be extremely low and were found primarily in the accessory phases rather than in the pure olivine. An unusual bimodal Mn distribution was noted in the pallasites, and Eagle Station had a chondritic normalized REE pattern enrichedin the heavy REE. The silicate phases of pallasites and mesosiderites were shown to be sufficiently diverse in origin such that separate classifications are entirely justified

A cross-sectional study of retired Great British Olympians (Berlin 1936 - Sochi 2014):Olympic career injuries, joint health in later life, and reasons for retirement from Olympic sport

The relationship between Olympic career sport injury and the long-term musculoskeletal health of the elite athlete remains unclear. This study describes the lifetime prevalence of medical attention injuries that occurred during training and/or competition as part of the athlete’s Olympic career, reasons for retirement from Olympic sport, and the point prevalence of pain and osteoarthritis (OA) among retired Great Britain’s (GB) Olympians

Effects of land acquisition alternatives on optimal farm plans for North Missouri

Includes bibliographical references