Cellular and Molecular Mechanisms Underlying Leptin’s Metabolic Effects

Obesity is rapidly increasing in prevalence, and has become one of the leading contributors to poor health in the world. Increased body weight by necessity must be a result of increased nutrient intake relative to total energy expenditure. While many have focused on the importance of caloric consumption in determining weight, it is increasingly clear that differences in energy expenditure, basal metabolic rates and/or adaptive thermogenesis are also important variables that contribute to human obesity. The experiments in this thesis start off by demonstrating that a significant portion of leptin-mediated weight loss is the result of an increase in energy expenditure caused by the hormone. They then go on to take a closer look at three candidate organs in which such changes in caloric expenditure are likely to be occurring. Our study finds that leptin treatment of ob/ob mice reduces the basal metabolic rate, uncoupled respiration (i.e. leak), and non-mitochondrial respiration of primary hepatocytes. We show that this is due to changes in the substrate oxidation system in liver mitochondria as well as changes in mitochondrial structure, and volume density. These changes are directly caused by leptin, and are not downstream of the hormone’s correction of hepatic steatosis. We next explored the proteomic and lipidomic modifications underlying the changes discussed above. Leptin-mediated changes in three components of the 1mitochondrial respiratory chain can account for the aforementioned metabolic effects of the hormone in the liver. Dramatic alterations in levels of the enzyme ELOVL5 might be responsible for the hepatic steatosis exhibited with leptin deficiency, and for its correction with leptin treatment. Furthermore, differences in mitochondrial cardiolipin levels may also be associated with the observed leptin-mediated changes in the liver. Finally, we show a trend that leptin may be altering the levels of reactive oxygen species in hepatic mitochondria. Having completed a thorough investigation into leptin-mediated changes in the liver, we moved on to the other two candidate organs, the heart and skeletal muscle. Our results show that leptin clearly modulates mitochondrial respiration in these tissues, though we cannot yet say exactly how it does so. In conclusion, this thesis illustrates the effects of leptin levels on the liver, and details the mechanisms by which the hormone induces change down to the proteomic level. It also shows clear leptin-mediated effects in skeletal muscle and the heart, and sets the stage for further investigation into the role of these tissues in leptin induced weight loss

Does Fecal Microbiota Transplantation Cause Clinical Remission in Patients with Ulcerative Colitis?

Objective: The objective of this selective EBM review is to determine whether or not “Does Fecal Microbiota Transplantation cause Clinical Remission in Patients with Ulcerative Colitis?” Study Design: Review of three English language primary studies published in 2015. Data Sources: Two randomized control trials and a cohort study determining if fecal microbiota transplantation does lead to clinical remission of Ulcerative Colitis were found by using PubMed and Cochrane databases. Outcome(s) Measured: The outcomes measured in all three studies were patient oriented evidence that matters which is clinical remission. The outcomes in the Moayyedi et al. was measured by the Mayo Score The Rossen et al. study determined clinical remission as SCCAI score ≤ 2 in combination with ≥1 point improvement on the combined Mayo endoscopic score of the sigmoid and rectum, compared to the baseline sigmoidoscopy, 12 weeks after the first treatment. The Wei et al. trail determined clinical remission was defined as IBDQ \u3e170 and Mayo score \u3c2 in Ulcerative Colitis. Results: This review compares two randomized, double blind, placebo controlled clinical trials and one cohort study in which the Moayyedi et al. and Wei et al. trial proved that Fecal microbiota transplantation is effective in providing clinical remission in patients with active Ulcerative Colitis; however, the Rossen et al. trial showed there was no significant statistical difference between the experimental [FMT-D] and the placebo [FMT-A] group in inducing clinical remission in patients with active Ulcerative Colitis. Conclusions: Fecal Microbiota Transplantation does seem to provide effective treatment in causing clinical remission of Ulcerative Colitis overall according to the three studies in this review

Growth Kinetics of \u3ci\u3eSalmonella\u3c/i\u3e Spp. During Post-Harvest Storage of Fresh and Fresh-Cut Papaya

Fresh produce safety is major concern in United States. Fresh produce has been associated with numerous food-borne outbreaks each year. Salmonella has been a recurring issue in the papaya industry. Since 2010, imported papayas have been implicated in 8 multistate outbreaks associated with Salmonella spp. causing 480 illnesses, 113 hospitalization and 3 deaths. The main reason behind this problem is as fresh papaya is grown on fields where they are constantly exposed to preharvest microbial contamination through contaminated irrigation water, agricultural soil, raw manure and/or feces deposited by intruding domestic or wild animals. Moreover, majority fresh papaya is also consumed raw which intensifies the risk to public health. Once contaminated, survival of foodborne pathogen is dependent on storage conditions and physico-chemical properties of fresh produce. The main objective of this study is to understand the survival kinetics of Salmonella spp. in fresh and fresh-cut papaya of different ripeness levels. In this study effect of storage relative humidity (RH): 55, and 90% on the survival kinetics was determined over a period of 7-14 days at 4, 12, and 21ºC. In addition, effect of fruit ripeness on the survival kinetics of Salmonella spp. were also examined. Results showed that papaya ripeness level in combination with storage temperature and RH have shown to affect Salmonella survival on both fresh-cut papaya and papaya peel. Increasing the fruit ripeness level from 0 to 100 %, storage temperature from 4 to 21 °C and RH from 55 to 90 % increased the log survival. Samples at low ripeness levels showed slower growth of yeast and molds compared to samples at higher ripeness levels. Ripeness levels also showed an effect on the total soluble solids content of fresh-cut papaya during the storage. Baranyi and Roberts model better described the growth behavior of Salmonella spp. on the fresh and fresh-cut papaya of different ripeness levels at the tested conditions

COMPARISONS OF SHOULDER GIRDLE STRENGTH, EXPLOSIVE LEG POWER AND ABDOMINAL STRENGTH AMONG JUMPERS, THROWERS AND SPRINTERS

The was designed to compare the three parameters viz. Shoulder girdle strength, explosive leg power and abdominal strength among jumpers, throwers and sprinters. A total of forty five subjects fifteen of each specialization were included in the study (Age group – 22-25 years). Three tests viz. Medicine Ball Throw Test, Sargent Jump Test (Vertical Jump), Bent-Knee Sit Ups were administered for testing Shoulder Girdle Strength, Explosive Leg Power and Abdominal Strength respectively. One-way ANOVA was applied to compare the three groups. Results revealed that significant differences exist among Jumpers, Throwers and Sprinters on all three parameters (p<.05). To conclude, Throwers exhibit more Shoulder Girdle Strength than jumpers and sprinters, Jumpers had more Explosive Leg Strength than throwers and sprinters, and Sprinters own more Abdominal Strength than Jumpers and Throwers.  Article visualizations