The role of strain in the response of rapidly growing young male rat bones to parathyroid hormone

Abstract Human parathyroid hormone (hPTH 1-34) stimulates an anabolic response in human and animal skeletons; however, it is unclear if the effect is strain dependent. To determine if the anabolic response to hPTH (1-34) was dependent upon strain in rats we used 2 outbred strains (Sprague Dawley, Wistar), 2 inbred strains (Fischer 344, Wistar spontaneously hypertensive:SHR), and 2 mutant strains (Zucker obese, Zucker lean) of rats. Male rats, 5 weeks of age, from each strain were treated subcutaneously with 80ug/kg body weight hPTH (1-34) or vehicle for 12 days. The response to PTH was similar in all strains whereby PTH exerted an anabolic effect on femoral bone mass and cancellous bone histology that was independent of strain differences. Histomorphometric indices of bone volume, mineralized surface and bone formation in lumbar vertebrae increased in all PTH-treated rats. Additionally, femur bone mineral content and bone mineral density measured by dual energy X-ray absorptiometry (DEXA), and ash weight increased in all PTH-treated rats. These increases occurred regardless of strain. In summary, PTH exerted comparable anabolic effects on bone mass, bone mineral density and bone formation in all rat models tested demonstrating that the skeletal responsiveness to PTH was not dependent upon strain

The impact of oat structure and β-glucan on in vitro lipid digestion

Oat β-glucan has been shown to play a positive role in influencing lipid and cholesterol metabolism. However, the mechanisms behind these beneficial effects are not fully understood. The purpose of the current work was to investigate some of the possible mechanisms behind the cholesterol lowering effect of oat β-glucan, and how processing of oat modulates lipolysis. β-Glucan release, and the rate and extent of lipolysis measured in the presence of different sources of oat β-glucan, were investigated during gastrointestinal digestion. Only a fraction of the original β-glucan content was released during digestion. Oat flakes and flour appeared to have a more significant effect on lipolysis than purified β-glucan. These findings show that the positive action of β-glucan is likely to involve complex processes and interactions with the food matrix. This work also highlights the importance of considering the structure and physicochemical properties of foods, and not just the nutrient content

The risk of metabolic syndrome as a result of lifestyle among Ellisras rural young adults

The study aimed to investigate the association between metabolic syndrome (MetS) and lifestyle risk factors among Ellisras adults. A cross-sectional study was conducted on 624 adults (306 males and 318 females). MetS was defined according to the criteria of the International Diabetes Federation. The prevalence of MetS was 23.1% (8.6% males and 36.8 % females). Females appeared to have higher mean values for waist circumference (WC), fasting blood glucose (FBG), total cholesterol (TCHOL) and low-density lipoprotein cholesterol (LDL-C), while males had high mean values for high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), systolic blood pressure (SBP) and diastolic blood pressure (DBP). No significant age and gender differences were observed for dietary intake. Significantly more females (51.9%) presented with increased WC than males (4.6%). Participants who had a high dietary energy intake were significantly less likely to present with larger WC (OR: 0.250 95% CI [0.161; 0.389]), low HDL-C (OR: 0.306 95% CI [0.220; 0.425]) and high LDL-C (OR: 0.583 95% CI [0.418; 0.812]) but more likely to present with elevated FBG (OR: 1.01 95% CI [0.735; 1.386]), high TCHOL (OR: 1.039 95% CI [0.575; 1.337]), high TG (OR: 1.186 95% CI [0.695; 2.023]) and hypertension (OR: 5.205 95% CI [3.156; 8.585]). After adjusting for age, gender, smoking, and alcohol status, high energy intake was more than two times likely to predict MetS in adults with a large WC (OR: 2.766 95% CI [0.863; 3.477] and elevated FBG (OR: 2.227 95% CI [1.051; 3.328]). Therefore, identifying groups that are at an increased risk and those that are in their early stages of MetS will help improve and prevent the increase of the MetS in the future

Interactions of bile salts with a dietary fibre, methylcellulose, and impact on lipolysis

Methylcellulose (MC) has a demonstrated capacity to reduce fat absorption, hypothetically through bile salt (BS) activity inhibition. We investigated MC cholesterol-lowering mechanism, and compared the influence of two BS, sodium taurocholate (NaTC) and sodium taurodeoxycholate (NaTDC), which differ slightly by their architecture and exhibit contrasting functions during lipolysis. BS/MC bulk interactions were investigated by rheology, and BS behaviour at the MC/water interface studied with surface pressure and ellipsometry measurements. In vitro lipolysis studies were performed to evaluate the effect of BS on MC-stabilised emulsion droplets microstructure, with confocal microscopy, and free fatty acids release, with the pH-stat method. Our results demonstrate that BS structure dictates their interactions with MC, which, in turn, impact lipolysis. Compared to NaTC, NaTDC alters MC viscoelasticity more significantly, which may correlate with its weaker ability to promote lipolysis, and desorbs from the interface at lower concentrations, which may explain its higher propensity to destabilise emulsions

The Amino Acid Composition of Microorganisms

Despite the extensive data that has accumulated on the chemical composition of microbial cells, information concerning microbial proteins, which are of major importance among cellular constituents, is fragmentary and, in part, inaccurate. This has been due primarily to inadequate and unreliable analytical methods for the determination of the basic protein units, the amino acids. The literature to 1926 on the amino acids in bacteria, yeasts, and fungi has been reviewed by Bu-chanan and Fulmer (1928). More recent papers which deal primarily with the amino acids of various species of Azotobacter are cited by Camien, Salle, and Dunn (1945). Similar information on marine and fresh-water algae is also available (Mazur and Clarke, 1938, 1942) as well as more recent data on yeasts (Sagara, 1930; Fink and Just, 1942; Block and Bolling, 1945). In addition to recording some of the types and approximate quantities of amino acids in various microorganisms, early investigators attempted to determine whether the amino acid composition of a particular organism is constant or varies with environmental conditions, especially with the composition of the medium