Lipoprotein Lipase Overexpression in Skeletal Muscle Attenuates Weight Regain by Potentiating Energy Expenditure

Moderate weight loss improves numerous risk factors for cardiometabolic disease; however, long-term weight loss maintenance (WLM) is often thwarted by metabolic adaptations that suppress energy expenditure and facilitate weight regain. Skeletal muscle has a prominent role in energy homeostasis; therefore, we investigated the effect of WLM and weight regain on skeletal muscle in rodents. In skeletal muscle of obesity-prone rats, WLM reduced fat oxidative capacity and downregulated genes involved in fat metabolism. Interestingly, even after weight was regained, genes involved in fat metabolism were also reduced. We then subjected mice with skeletal muscle lipoprotein lipase overexpression (mCK-hLPL), which augments fat metabolism, to WLM and weight regain and found that mCK-hLPL attenuates weight regain by potentiating energy expenditure. Irrespective of genotype, weight regain suppressed dietary fat oxidation and downregulated genes involved in fat metabolism in skeletal muscle. However, mCK-hLPL mice oxidized more fat throughout weight regain and had greater expression of genes involved in fat metabolism and lower expression of genes involved in carbohydrate metabolism during WLM and regain. In summary, these results suggest that skeletal muscle fat oxidation is reduced during WLM and regain, and therapies that improve skeletal muscle fat metabolism may attenuate rapid weight regain.     

A comparison of laboratory,clinical, and self-report measures of prospective memory in healthy adults and individuals with brain injury

Individuals with traumatic brain injury (TBI) have demonstrated deficits in prospective memory (PM) functioning when compared to healthy adults. These deficits have been measured using laboratory measures, clinical measures, and self-report questionnaires. However, PM has been shown to involve multiple cognitive processes and have a variety of stages. Thus, it is not known whether these measures all assess the same aspects of PM. Thus, this study was designed to measure the convergent validity of the three types of PM measures in both healthy adults and individuals with TBI. We aimed to investigate the convergent validity of the three types of tasks in two ways. First, we sought to investigate whether the PM deficits experienced by people with TBI are consistent across tasks. Second, we sought to examine the relationship between the three types of tasks. Results demonstrated that while all three types of measures were sensitive to PM deficits in TBI, there were differences in the aspects/processes of PM being measured. Data from the laboratory measure suggested a specific difficulty with detecting the correct cue. Data from the clinical measure suggested that TBI has a greater effect on time-based cues than event-based cues and that the primary deficit is a prospective intention retrieval deficit rather than the retrospective memory component. In addition, those with TBI did not differ from healthy adults when the time delay was short enough, suggesting that PM is not universally impaired. Data from the self-report questionnaire suggested that those with TBI are more sensitive to difficulties with basic activities of daily living rather than instrumental activities on daily living. These results are discussed in terms of rehabilitation techniques that could focus first on cue detection and use basic activities of daily living as outcome measures.     

Effects of bazedoxifene on bone mineral density,bone turnover,and safety in postmenopausal japanese women with osteoporosis

This randomized, double‐blind, placebo‐controlled, dose‐response late phase 2 study evaluated the efficacy and safety of bazedoxifene in postmenopausal Japanese women 85 years of age or younger with osteoporosis. Eligible subjects received daily treatment with oral doses of bazedoxifene 20 or 40 mg or placebo for 2 years. Efficacy assessments included bone mineral density (BMD) at the lumbar spine and other skeletal sites, bone turnover marker levels, lipid parameters, and incidence of new fractures. Of 429 randomized subjects, 387 were evaluable for efficacy, and 423 were included in the safety analyses (mean age, 64 years). At 2 years, the mean percent changes from baseline in lumbar spine BMD were significantly greater with bazedoxifene 20 and 40 mg (2.43% and 2.74%, respectively) than with placebo (?0.65%, p < .001 for both). Both bazedoxifene doses significantly improved BMD at the total hip, femoral neck, and greater trochanter compared with placebo (p < .001 for all). Decreases in bone turnover markers were observed with bazedoxifene 20 and 40 mg as early as 12 weeks (p < .05 for all) and were sustained throughout the study. Total and low‐density lipoprotein cholesterol levels were significantly decreased from baseline with both bazedoxifene doses compared with placebo (p < .05 for all). Incidences of new vertebral and nonvertebral fractures were similar among the bazedoxifene and placebo groups. Overall, the incidence of adverse events with bazedoxifene 20 and 40 mg was similar to that with placebo. Bazedoxifene significantly improved BMD, reduced bone turnover, and was well tolerated in postmenopausal Japanese women with osteoporosis. © 2011 American Society for Bone and Mineral Research.     

Characterization of human UMP/CMP kinase and its phosphorylation of D- and L-form deoxycytidine analogue monophosphates

Pyrimidine nucleoside monophosphate kinase [UMP/CMP kinase (UMP/CMPK);EC 2.7.4.14] plays a crucial role in the formation of UDP, CDP, and dCDP, which are required for cellular nucleic acid synthesis. Several cytidine and deoxycytidine analogues are important anticancer and antiviral drugs. These drugs require stepwise phosphorylation to their triphosphate forms to exert their therapeutic effects. The role of UMP/CMPK for the phosphorylation of nucleoside analogues has been indicated. Thus, we cloned the human UMP/CMPK gene, expressed it in Escherichia coli, and purified it to homogeneity. Its kinetic properties were determined. UMP and CMP proved to be far better substrates than dCMP. UMP/CMPK used all of the nucleoside triphosphates as phosphate donors, with ATP and dATP being the best donors and CTP being the poorest. Furthermore, UMP/CMPK was able to phosphorylate all of the deoxycytidine analogue monophosphates that we tested. The relative efficiency was as follows: arabinofuranosyl-CMP > dCMP > beta-L-2',3'-dideoxy-3'-thia-CMP > Gemcitabine monophosphate > beta-D-2',3'-dideoxy-CMP; beta-L-2',3'-dideoxy-2',3'-didehydro-5-fluoro-CMP; beta-L-2',3'-dideoxy-5-fluoro-3'-thia-CMP > beta-L-2',3'-dideoxy-CMP > beta-L-dioxolane-CMP. By comparing the relative V(max)/K(m) values of D- and L-form dideoxy-CMP, we showed that this kinase lacked stereoselectivity. Reducing agents, such as DTT, 2-mercaptoethanol, and thioredoxin, were able to activate this enzyme, suggesting that its activity may be regulated by redox potential in vivo. UMP/CMPK localized predominantly to the cytoplasm. In addition, 196-amino acid UMP/CMPK was the actual form of UMP/CMPK, rather than the 228-amino acid form as suggested before.     

Formation and stability of linear plasmids in a recombination deficient strain of yeast

Summary Natural termini from macronuclear DNA of the ciliated protozoans Tetrahymena thermophila and Oxytricha fallax can support telomere formation in yeast. However, plasmids carrying these ciliate termini are modified by the addition of DNA which hybridizes to the synthetic oligonucleotide poly [d(C-A)], a sequence which also hybridizes to terminal restriction fragments from yeast chromosomes but not to Tetrahymena or Oxytricha macronuclear DNAs. Thus, in yeast, the creation of new telomeres on ciliate termini involves the acquisition of yeast-specific terminal sequences presumably by either recombination or non-templated DNA synthesis. The RAD52 gene is required for the majority of yeast mitotic and meiotic recombination events. Moreover, the absence of an active RAD52 gene product results in high rates of chromosome loss. Here we demonstrate that terminal restriction fragments from Tetrahymena macronuclear ribosomal DNA (rDNA) support the formation of modified telomeres in a yeast strain carrying a defect in the RAD52 gene. Moreover, linear plasmids bearing these modified ciliate termini are stably propagated in rad52 ^– cells.     

Evolution of an in vivo bioreactor.

The ideal bone graft substitute requires osteoconductive, osteoinductive, and osteogenic components. This study introduces an "in vivo bioreactor," a model in which pluripotent cells are recruited from circulating blood to a vascularized coralline scaffold supplemented with bone morphogenetic protein-2 (BMP-2). The bioreactor generates new, ectopic host bone with the capability of vascularized tissue transfer. More importantly, bone is reproducibly formed in a closed and malleable environment. In a rat model, the superficial inferior epigastric vessels were isolated, ligated, and then threaded through a prefabricated coral cylinder (hydroxyapatite, ProOsteon 500). Experimental groups were characterized by the following variables: (1) with/without incorporation of vascular pedicle; (2) with/without addition of BMP-2 (0.02 mg/cm3). Scaffolds were harvested 6 weeks after implantation, embedded and sectioned. Tissue samples were decalcified, fixed, and stained with H&E, trichrome green, and CD31/PECAM-1 (a marker of endothelial cells). Vascularized coral scaffolds supplemented with BMP-2 presumably recruited circulating mesenchymal stem cells to generate bone. Bone formation was quantified through histological analysis, and reported as a percentage, area bone/area cross section scaffold x 100. Mean bone formation was 11.30%+/-1.19. All scaffolds supplied by the vascular pedicle, regardless of BMP-2 supplementation, demonstrated neo-vascular ingrowth. Scaffolds lacking a pedicle showed no evidence of vascular ingrowth or bone formation. This paper introduces a model of a novel "in vivo bioreactor" that has future clinical and research applications. The tissue engineering applications of the "bioreactor" include treatment of skeletal defects (nonunion, tumor post-resection reconstruction). The bioreactor also may serve as a unique model in which to study primary and metastatic cancers of bone.     

Testosterone as a predictor of pathological stage in clinically localized prostate cancer

PURPOSE: Substantial controversy exists in the literature regarding the association between pretreatment testosterone and disease outcome in patients with prostate cancer. We explored the relationship between preoperative total testosterone, and pathological stage and progression in patients with clinically localized prostate cancer treated with radical prostatectomy. MATERIALS AND METHODS: We retrospectively reviewed the records of consecutive patients with clinically localized prostate cancer treated with radical prostatectomy between January 1990 and June 2003. A total of 326 patients with pretreatment testosterone levels available were eligible for this analysis. Biochemical progression (BCR) was defined by postoperative prostate specific antigen (PSA) greater than 0.4 ng/ml with a confirmatory increase and it occurred in 41 men. No men received adjuvant therapy. Univariate and multivariate logistic regression analyses were done to examine whether pretreatment testosterone was associated with pathological stage. Cox regression was used to assess the association of testosterone and BCR. RESULTS: Median PSA was 6.01 ng/ml (range 0.13 to 86), testosterone was 385 ng/dl (range 133 to 998) and followup was 36 months (range 4 to 136). In 245 patients (75%) disease was organ confined. Lower testosterone correlated with adverse pathological stage on multivariate analysis (p = 0.01), as did clinical stage, biopsy grade and PSA. However, we found no relationship between testosterone and BCR after adjusting for covariates. Furthermore, we found no evidence of an interaction between PSA and testosterone (p = 0.4). CONCLUSIONS: On multivariate analysis low preoperative total testosterone was associated with advanced pathological stage but not with BCR. Future studies are warranted with data on more patients who have progressed.     

The enzymes of pyrimidine biosynthesis in a range of parasitic protozoa and helminths

The activities of carbamoylphosphate synthase, aspartate transcarbamoylase, dihydroorotase, orotate phosphoribosyl transferase and orotidine-5'-phosphate decarboxylase, five of the six enzymes of pyrimidine biosynthesis, have been measured in Crithidia fasciculata, Trypanosoma cruzi, Leishmania major, Trichomonas vaginalis, Eimeria tenella, Toxoplasma gondii, Plasmodium berghei, Fasciola gigantica, Schistosoma mansoni, Hymenolepis diminuta, Nippostrongylus brasiliensis and Trichuris muris. The majority of organisms contained all five enzyme activities. However, in T. vaginalis only carbamoylphosphate synthetase activity and in E. tenella only orotate phosphoribosyl transferase and orotidine-5'-phosphate decarboxylase activities could be detected. It appears therefore that the ability to synthesise pyrimidines by the de novo route is probably both common and widespread amongst parasitic organisms.     

Is the use of laparoscopy to determine presence of contralateral patent processus vaginalis justified in children greater than 2 years of age?

Purpose

Contralateral inguinal hernia exploration in cases of unilateral inguinal hernia remains a controversial topic. The authors have been using the in-line laparoscopic technique of contralateral evaluation for unilateral inguinal hernia in children less than 2 years of age. Because of the case of the procedure and lack of morbidity, we decided to expand the use of this procedure up to age 8 years in January 2000. The purpose of this study is to evaluate if the incidence of contralateral hernia in children greater than 2 years justifies the procedure.

Methods

This is a retrospective study of all children who underwent contralateral exploration for unilateral inguinal exploration over a 20-month period. The procedure was offered routinely to all patients up to age 8 years. During the repair, the contralateral inguinal ring was examined laparoscopically using the in-line technique for the presence of a contralateral hernia. The incidence of contralateral hernia was determined, and the results were stratified by age. Patients who underwent unilateral inguinal hernia repair without laparoscopic contralateral exploration or bilateral inguinal hernia repair without laparoscopic contralateral explorations were excluded from the study.

Results

A total of 284 laparoscopic explorations were performed. Positive explorations were seen in 65 of 171 (38%) of children less than 2 years of age, 19 of 101 (20%) of children 2 to 8 years of age, and 1 of 12 children greater than 8 years of age (8%). There were no operative complications.

Conclusions

Laparoscopic contralateral exploration is safe and effective. Because of the low morbidity, the risk to benefit ratio warrants its use in children up to 8 years of age. This sample size is too small to make any meaningful statement in children older than 8 years.