A Case of Primary Hyperparathyroidism Secondary to Parathyroid Adenoma in a Pediatric Patient.

Background/Objective: Although common in adults, primary hyperparathyroidism (PHPT) is a rare condition in children with the most common etiology being solitary parathyroid adenoma (PTA). The typical presentation is symptomatic hypercalcemia. Management of PHTP secondary to PTA requires excision of the adenoma. Case Report: A 13-year-old adolescent boy presented because of orbital cellulitis and was noted to have hypercalcemia. Despite this, the patient was curiously asymptomatic. Further investigations yielded an elevated parathyroid hormone (PTH) level and a normal urine calcium-to-creatinine ratio making the most likely cause of hypercalcemia PHTP secondary to PTA. Imaging demonstrated PTA. The patient underwent parathyroidectomy with the pathology demonstrating PTA. Postoperatively, the PTH levels were undetectable; hence, the patient was treated with calcitriol and calcium supplementation for 1 month and 4 months, respectively. Genetic work-up for multiple endocrine neoplasia 1 and rearranged during transfection mutations was negative. Discussion: Solitary PTA is the most common cause of PHPT. Adenomas are mostly sporadic or may be a manifestation of an inheritable syndrome, such as multiple endocrine neoplasia. Although symptomatic disease is more common in children, our patient denied any hypercalcemia symptoms. The distinguishing biochemical feature of PHPT because of PTA is high or inappropriately normal PTH level in the context of high-normal or elevated serum calcium levels. Urinary calcium excretion is usually normal or high. PTAs are localized by ultrasound and Tc-99m-Sestamibi scintigraphy. Management includes parathyroidectomy and monitoring for postoperative hypocalcemia. Conclusion: In a child or adolescent presenting with hypercalcemia and elevated PTH levels, it is important to consider PHPT secondary to PTA, because an early diagnosis will aid in preventing complications from hypercalcemia.

Shiga-toxigenic Escherichia coli from animal food sources in Mauritius: Prevalence, serogroup diversity and virulence profiles.

Shiga-toxigenic Escherichia coli (STEC) are important human pathogens associated with diarrhea and in some cases haemorrhagic colitis. Contaminated food derived from cattle and wildlife species are often associated with disease outbreaks. In this study, we report the prevalence, serogroup diversity and virulence profiles of STEC strains derived from cattle, rusa deer and pig. Of the 422 samples analyzed, STEC were detected in 40% (80/200) of cattle, 27.0% (33/122) of deer and 13.0% (13/100) of pigs. STEC isolates belonged to 38 O-serogroups whereby 5.2% (24/462) of the isolates belonged to clinically important EHEC-7 serogroups: O26 (n = 2), O103 (n = 1), O145 (n = 3) and O157 (n = 18). Fourteen serogroups (O26, O51, O84, O91, O100, O104, O110, O117, O145, O146, O156, O157, O177 and ONT) displayed multiple virulence profiles. We also identified two serovars (O117 and O119) in deer which are not well-documented in epidemiological surveys. 73.7% (28/38) of recovered O-serogroups are known to be associated with serious human illnesses including haemolytic uremic syndrome (HUS) and bloody diarrhea. STEC isolates harboring single genotypes stx1, stx2, eae and hlyA accounted for 3.0% (14/462), 9.1% (42/462), 47.6% (220/462) and 1.7% (8/462) of all STEC isolates screened, respectively. Virulence combinations stx1 and stx2 were harboured by 1.3% of isolates while strains with genetic profiles eae/hlyA were the second most prevalent amongst STEC isolates. The full known virulent genotypes (stx2/eae, stx1/stx2/eae, stx1/stx2/hlyA and stx2/eae/hlyA) were present in 22 of the 462 STEC strains. A total of 10 different virulence patterns were recovered amongst animal species. Phylogeny of the gnd gene showed that amongst STEC strains, serovar O100 outlined the main cluster. Fourteen (n = 14) different sequence types (STs) were identified from a panel of twenty (n = 20) STEC isolates. One of the isolate (PG007B) possessed a unique ST (adk 10, fumC 693, gyrB 4, icd 1, mdh 8, purA 8, recA 2) that could not be assigned using MLST databases. None of the ST's recovered in deer were observed in domestic species. Our findings shows that food associated animals found on the tropical island of Mauritius carry a diversity of STEC strains with many serovars known to be associated with human disease. This report indicates that increased awareness, surveillance and hygienic attention at critical stages of the human food chain are warranted.

The cross-sectional association between diabetes and orthostatic hypotension in community-dwelling older people.

AIMS: Orthostatic hypotension is a recognized complication of diabetes, but studies examining prevalence in diabetes are limited. The aim of this study was to ascertain the prevalence of orthostatic hypotension and the pattern of orthostatic BP response in a cohort of people with diabetes aged ≥ 50 years, embedded within the Irish Longitudinal Study of Ageing. METHODS: Orthostatic hypotension was defined as a drop in systolic blood pressure (SBP) ≥ 20 mmHg or drop in diastolic blood pressure (DBP) ≥ 10 mmHg at 30 s after standing. Diabetes was defined by self-report but cross-checked against HbA1c and medication records. Multilevel mixed effects linear regression models were used to compare orthostatic BP in people with and without diabetes. RESULTS: Some 3222 people were included, 7% (213 of 3222) of whom had diabetes. Prevalence of orthostatic hypotension in the group with diabetes was 22% (46 of 213) vs. 13% in those without diabetes; χ2 = 12.43; P < 0.001. Multilevel models demonstrated prolonged recovery of DBP in people with diabetes, with only 41% (87 of 213) returning to baseline by 60 s. Logistic regression models demonstrated that diabetes was associated with a significantly increased likelihood of orthostatic hypotension (odds ratio 1.84, 95% confidence interval 1.30-2.59; P = 0.001) and this remained robust after controlling for covariates. CONCLUSION: Over one-fifth of older people with diabetes had orthostatic hypotension. Recovery of DBP is related to dynamic changes in total peripheral resistance and impairment of this baroreflex-mediated response may explain the higher prevalence in diabetes. Given the prognostic implications when co-existing with diabetes, orthostatic hypotension may represent a potentially modifiable risk factor for adverse outcomes in late-life diabetes.

Measuring the impact of oesophagectomy on physical functioning and physical activity participation: a prospective study.

BACKGROUND: Oesophagectomy remains the only curative intervention for oesophageal cancer, with defined nutritional and health-related quality of life (HR-QOL) consequences. It follows therefore that there is a significant risk of decline in physical wellbeing with oesophagectomy however this has been inadequately quantified. This study prospectively examines change in physical functioning and habitual physical activity participation, from pre-surgery through 6-months post-oesophagectomy. METHODS: Patients scheduled for oesophagectomy with curative intent were recruited. Key domains of physical functioning including exercise tolerance (six-minute walk test (6MWT)) and muscle strength (hand-grip strength), and habitual physical activity participation, including sedentary behaviour (accelerometry) were measured pre-surgery (T0) and repeated at 1-month (T1) and 6-months (T2) post-surgery. HR-QOL was measured using the EORTC-QOL C30. RESULTS: Thirty-six participants were studied (mean age 62.4 (8.8) years, n = 26 male, n = 26 transthoracic oesophagectomy). Mean 6MWT distance decreased significantly from T0 to T1 (p = 0.006) and returned to T0 levels between T1 and T2 (p < 0.001). Percentage time spent sedentary increased throughout recovery (p < 0.001) and remained significantly higher at T2 in comparison to T0 (p = 0.003). In contrast, percentage time spent engaged in either light or moderate-to-vigorous intensity activity, all reduced significantly (p < 0.001 for both) and remained significantly lower at T2 in comparison to T0 (p = 0.009 and p = 0.01 respectively). Patients reported deficits in multiple domains of HR-QOL during recovery including global health status (p = 0.04), physical functioning (p < 0.001) and role functioning (p < 0.001). Role functioning remained a clinically important 33-points lower than pre-operative values at T2. CONCLUSION: Habitual physical activity participation remains significantly impaired at 6-months post-oesophagectomy. Physical activity is a measurable and modifiable target for physical rehabilitation, which is closely aligned with patient-reported deficits in role functioning. Rehabilitation aimed at optimising physical health in oesophageal cancer survivorship is warranted.

Effect of preoperative inspiratory muscle training on physical functioning following esophagectomy.

This study aims to examine the effect of preoperative inspiratory muscle training (IMT) on pre- and postoperative functional exercise performance in patients undergoing esophagectomy. A subcohort of patients recruited to the PREPARE randomized control trial were studied. Following evaluation of respiratory muscle function (spirometry, maximum inspiratory pressure (MIP), and inspiratory muscle endurance), postoperative mobilization (accelerometry) and postoperative physical functioning (6-minute walk test (6MWT)), participants scheduled for esophagectomy were randomly assigned to either 2 weeks of preoperative IMT or a control group. Measures were repeated on the day before surgery and postoperatively. Sixty participants (mean (standard deviation) age 64.13 (7.8) years; n = 42 male; n = 43 transthoracic esophagectomy; n = 17 transhiatial esophagectomy) were included in the final analysis (n = 28 IMT; n = 32 control). There was a significant improvement in preoperative MIP (P = 0.03) and inspiratory muscle endurance (P = 0.04); however preoperative 6MWT distance did not change. Postoperatively, control participants were more active on postoperative day (POD)1, and from POD1-POD5 (P = 0.04). Predischarge, 6MWT distance was significantly lower in the IMT group (305.61 (116.3) m) compared to controls (380.2 (47.1) m, P = 0.03). Despite an increase in preoperative respiratory muscle function, preoperative IMT does not improve pre- or postoperative physical functioning or postoperative mobilization following esophagectomy.

Diagnostic challenges in pyogenic spinal infection: an expanded role for FDG-PET/CT.

In a preliminary investigation of FDG-PET/CT for assessment of therapy response of pyogenic spine infection, it was concluded that activity confined to the margins of a destroyed or degenerated joint with bone-on-bone contact represents nonseptic inflammation, regardless of the intensity of uptake. Only activity in bone, soft tissue, or within the epidural space represents active infection. The purpose of this investigation was to assess the performance of these pattern-based interpretation criteria in a series of problem cases of proven or suspected spine infection. Eighty-two FDG-PET/CTs were done for initial diagnosis because other imaging failed to provide a definitive diagnosis and 147 FDG-PET/CTs were done to assess treatment responses. Pattern-based interpretations were compared with the clinical diagnosis based on bacterial cultures and outcomes after cessation or withholding of antibiotic therapy. Pattern-based interpretation criteria achieved a sensitivity and specificity of 98 and 100%, respectively, for initial diagnosis and a specificity of 100% for assessment of treatment response. The same data was analyzed using intensity of activity as the primary factor. Sensitivity and specificity using the intensity-based criteria were 93 and 68%, respectively, for initial diagnosis, and the specificity of a negative interpretation for therapy response was 55%. Differences from pattern-based criteria are highly significant. Pattern-based criteria perform well in problem cases with equivocal MR and for treatment response because they correctly eliminate activity from nonspecific inflammation associated with destroyed joints with bone-on-bone contact. Response occurs within a timeframe that is useful for managing antibiotic therapy.

Sarcopenia during neoadjuvant therapy for oesophageal cancer: characterising the impact on muscle strength and physical performance.

PURPOSE: Preoperative chemo(radio)therapy for oesophageal cancer (OC) may have an attritional impact on body composition and functional status, impacting postoperative outcome. Physical decline with skeletal muscle loss has not been previously characterised in OC and may be amenable to physical rehabilitation. This study characterises skeletal muscle mass and physical performance from diagnosis to post-neoadjuvant therapy in patients undergoing preoperative chemo(radio)therapy for OC. METHODS: Measures of body composition (axial computerised tomography), muscle strength (handgrip), functional capacity (walking distance), anthropometry (weight, height and waist circumference), physical activity, quality-of-life and nutritional status were captured prospectively. Sarcopenia status was defined as pre-sarcopenic (low muscle mass only), sarcopenic (low muscle mass and low muscle strength or function) or severely sarcopenic (low muscle mass and low muscle strength and low muscle function). RESULTS: Twenty-eight participants were studied at both time points (mean age 62.86 ± 8.18 years, n = 23 male). Lean body mass reduced by 4.9 (95% confidence interval 3.2 to 6.7) kg and mean grip strength reduced by 4.3 (2.5 to 6.1) kg from pre- to post-neoadjuvant therapy. Quality-of-life scores capturing gastrointestinal symptoms improved. Measures of anthropometry, walking distance, physical activity and nutritional status did not change. There was an increase in sarcopenic status from diagnosis (pre-sarcopenic n = 2) to post-treatment (pre-sarcopenic n = 5, severely sarcopenic n = 1). CONCLUSIONS: Despite maintenance of body weight, functional capacity and activity habits, participants experience declines in muscle mass and strength. Interventions involving exercise and/or nutritional support to build muscle mass and strength during preoperative therapy, even in patients who are functioning normally, are warranted.

Isotretinoin administration improves sperm production in men with infertility from oligoasthenozoospermia: a pilot study.

There is currently no effective medical therapy for men with infertility due to oligoasthenozoospermia. As men with abnormal sperm production have lower concentrations of 13-cis-retinoic acid in their testes, we hypothesized that men with infertility from oligoasthenozoospermia might have improved sperm counts when treated with isotretinoin (13-cis-retinoic acid). We conducted a single-site, single-arm, pilot study to determine the effect of therapy with isotretinoin on sperm indices in 19 infertile men with oligoasthenozoospermia. Subjects were men between 21 and 60 years of age with infertility for longer than 12 months associated with sperm concentrations below 15 million sperm/mL. All men received isotretinoin 20 mg by mouth twice daily for 20 weeks. Subjects had semen analyses, physical examinations, and laboratory tests every 4 weeks during treatment. Nineteen men enrolled in the study. Median (25th, 75th) sperm concentration increased from 2.5 (0.1, 5.9) million/mL at baseline to 3.8 (2.1, 13.0) million/mL at the end of treatment (p = 0.006). No significant changes in sperm motility were observed. There was a trend toward improved sperm morphology (p = 0.056). Six pregnancies (three spontaneous and three from intracytoplasmic sperm injection) and five births occurred during the study. Four of the births, including all three of the spontaneous pregnancies, were observed in men with improvements in sperm counts with isotretinoin therapy. Treatment was well tolerated. Isotretinoin therapy improves sperm production in some men with oligoasthenozoospermia. Additional studies of isotretinoin in men with infertility from oligoasthenozoospermia are warranted.

Reduced fitness and physical functioning are long-term sequelae after curative treatment for esophageal cancer: a matched control study.

Reduced physical functioning is common following resections for esophageal cancer; however, objective data on physical performance outcomes in this cohort are rare. The aim of this study was to assess the physical performance and health related quality of life (HRQOL) of disease free survivors and compare findings in a case matched noncancer control group. Twenty-five males (mean (±SD) aged 63 (±6) years) who were over 6 months postesophagectomy and disease-free were compared with 25 controls (60 ± 6 years). Physical functioning was assessed through hand grip strength (dynamometry), exercise capacity (incremental shuttle walk test), physical activity levels (RT3 accelerometer), and body composition (bio-electrical impedance analysis). Health-related quality of life was measured using the EORTC QLQ-C30 questionnaire. Esophageal cancer survivors demonstrated significantly lower fitness (P < 0.001) and time spent in moderate (P < 0.001) and vigorous (P < 0.001) intensity physical activity compared with controls. Global health status and quality of life were similar in both groups (P = 0.245); however, physical and role functioning domains were lower in the cancer survivors (P < 0.001, and P = 0.001, respectively). These data show that disease-free survivors of curative esophageal cancer treatment demonstrate a significant compromise in physical functioning compared with controls, thus highlighting the multiple, complex rehabilitative needs of this cohort.

The use of three-dimensional strut plates for the management of mandibular angle fractures: a retrospective analysis of 222 patients.

This study was performed to evaluate the use of three-dimensional (3D) strut plates for the surgical management of mandibular angle fractures and to determine the subsequent postoperative complication rate. Two hundred and twenty-two patients met the inclusion criteria for mandible angle fracture at the university hospital in Miami between 2009 and 2013 and were included in this study. The treatment protocol for mandibular angle fractures included open reduction and internal fixation with the utilization of a 3D strut plate. Patients were not placed in postoperative intermaxillary fixation. An evaluation of the cases revealed a complication rate of 15.3%, of which 6.8% were considered major complications requiring a surgical intervention. The 3D strut plate has been found to have many advantages over single miniplate techniques with respect to the stability of the fracture and the rate of complications. Based on the current data, 3D strut plates provide a predictable result in the treatment of mandibular angle fractures.

New ASCO/CAP guideline recommendations for HER2 testing increase the proportion of reflex in situ hybridization tests and of HER2 positive breast cancers.

Accurate determination of tumour human epidermal growth factor receptor type 2 (HER2) status is critical for optimal treatment of breast cancer. In October 2013, the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP) issued joint updated guideline recommendations for HER2 testing in breast cancer, with a revised algorithm for interpretation of immunohistochemistry (IHC) and in situ hybridisation (ISH) results. This study investigates the impact on HER2 IHC categorisation, implication for reflex ISH testing and potential for identification of false negative IHC. HER2 IHC preparations on 251 invasive breast tumours, originally reported according to 2007 guidelines, were re-scored using 2013 guidelines and the diagnostic categories compared. The results of ISH testing on a separate cohort of 32 breast tumours reported as HER2 IHC 2+ following the introduction of the 2013 guidelines, that would have been designated 1+ according to 2007, were reviewed. Application of 2013 guidelines resulted in a decrease in tumours classified as HER2 negative (83/251 vs 144/251) and a comparable increase in those classified as equivocal (2+) (139/251 vs 80/251). Relatively few tumours were re-classified as positive (29/251 vs 27/251). Furthermore, 3/32 breast cancer cases (HER2 IHC 2+ as per 2013 guidelines, 1+ using 2007 guidelines) were HER2 ISH positive. Application of the 2013 guidelines increases the HER2 IHC equivocal (2+) category and requirement for reflex ISH testing. The reduced threshold for ISH testing identifies some patients with HER2 positive breast cancer whose tumours would have been categorised as HER2 negative according to the 2007 guidelines.

Aß oligomer toxicity inhibitor protects memory in models of synaptic toxicity.

BACKGROUND AND PURPOSE: Amyloid-ß (Aß) aggregation into synaptotoxic, prefibrillar oligomers is a major pathogenic event underlying the neuropathology of Alzheimer's disease (AD). The pharmacological and neuroprotective properties of a novel Aß aggregation inhibitor, SEN1269, were investigated on aggregation and cell viability and in test systems relevant to synaptic function and memory, using both synthetic Aß(1-42) and cell-derived Aß oligomers. EXPERIMENTAL APPROACH: Surface plasmon resonance studies measured binding of SEN1269 to Aß(1-42) . Thioflavin-T fluorescence and MTT assays were used to measure its ability to block Aß(1-42) -induced aggregation and reduction in cell viability. In vitro and in vivo long-term potentiation (LTP) experiments measured the effect of SEN1269 on deficits induced by synthetic Aß(1-42) and cell-derived Aß oligomers. Following i.c.v. administration of the latter, a complex (alternating-lever cyclic ratio) schedule of operant responding measured effects on memory in freely moving rats. KEY RESULTS: SEN1269 demonstrated direct binding to monomeric Aß(1-42) , produced a concentration-related blockade of Aß(1-42) aggregation and protected neuronal cell lines exposed to Aß(1-42) . In vitro, SEN1269 alleviated deficits in hippocampal LTP induced by Aß(1-42) and cell-derived Aß oligomers. In vivo, SEN1269 reduced the deficits in LTP and memory induced by i.c.v. administration of cell-derived Aß oligomers. CONCLUSIONS AND IMPLICATIONS: SEN1269 protected cells exposed to Aß(1-42) , displayed central activity with respect to reducing Aß-induced neurotoxicity and was neuroprotective in electrophysiological and behavioural models of memory relevant to Aß-induced neurodegeneration. It represents a promising lead for designing inhibitors of Aß-mediated synaptic toxicity as potential neuroprotective agents for treating AD.

Long-term ecosystem monitoring and assessment of the Detroit River and Western Lake Erie.

Over 35 years of US and Canadian pollution prevention and control efforts have led to substantial improvements in environmental quality of the Detroit River and western Lake Erie. However, the available information also shows that much remains to be done. Improvements in environmental quality have resulted in significant ecological recovery, including increasing populations of bald eagles (Haliaeetus leucocephalus), peregrine falcons (Falco columbarius), lake sturgeon (Acipenser fulvescens), lake whitefish (Coregonus clupeaformis), walleye (Sander vitreus), and burrowing mayflies (Hexagenia spp.). Although this recovery is remarkable, many challenges remain, including population growth, transportation expansion, and land use changes; nonpoint source pollution; toxic substances contamination; habitat loss and degradation; introduction of exotic species; and greenhouse gases and global warming. Research/monitoring must be sustained for effective management. Priority research and monitoring needs include: demonstrating and quantifying cause-effect relationships; establishing quantitative endpoints and desired future states; determining cumulative impacts and how indicators relate; improving modeling and prediction; prioritizing geographic areas for protection and restoration; and fostering long-term monitoring for adaptive management. Key management agencies, universities, and environmental and conservation organizations should pool resources and undertake comprehensive and integrative assessments of the health of the Detroit River and western Lake Erie at least every 5 years to practice adaptive management for long-term sustainability.

Intracellular acidification delays hormonal G2/M transition and inhibits G2/M transition triggered by thiophosphorylated MAPK in Xenopus oocytes.

Xenopus oocyte maturation is analogous to G2/M transition and characterized by germinal vesicle breakdown (GVBD), spindle formation, activation of MPF and Mos-Xp42(Mpk1) pathways. It is accompanied prior to GVBD by a transient increase in intracellular pH. We determined that a well known acidifying compound, NH(4)Cl, delayed progesterone-induced GVBD in a dose-dependent manner. GVBD(50) was delayed up to 2.3-fold by 10 mM NH(4)Cl. Cyclin B2 phosphorylation, Cdk1 Tyr15 dephosphorylation as well as p39(Mos) accumulation, Xp42(Mpk1) and p90(Rsk) phosphorylation induced by progesterone were also delayed by incubation of oocyte in NH(4)Cl. The delay induced by NH(4)Cl was prevented by injection of MOPS buffer pH 7.7. In contrast to acidifying medium, alkalyzing treatment such as Tris buffer pH 9 injections, accelerated GVBD, MPF and Xp42(Mpk1) activation, indicating that pHi changes control early steps of G2/M dynamics. When injected in an immature recipient oocyte, egg cytoplasm triggers GVBD through MPF auto-amplification, independently of protein synthesis. In these conditions, GVBD and Xp42(Mpk1) activation were delayed by high concentration of NH(4)Cl, which never prevented or delayed MPF activation. Strickingly, NH(4)Cl strongly inhibited thiophosphorylated active MAPK-induced GVBD and MPF activation. Nevertheless, Tris pH 9 did not have any effects on egg cytoplasm- or active MAPK-induced GVBD. Taken together, our results suggest that dynamic of early events driving Xp42(Mpk1) and MPF activation induced by progesterone may be negatively or positively regulated by pH(i) changes. However Xp42(Mpk1) pathway was inhibited by acidification alone. Finally, MPF auto-amplification loop was not sensitive to pH(i) changes.

Structure and seasonal dynamics of hyporheic zone microbial communities in free-stone rivers of the western United States.

The hyporheic zone of a river is characterized by being nonphotic, exhibiting chemical/redox gradients, and having a heterotrophic food web based on the consumption of organic carbon entrained from surface waters. Hyporheic microbial communities constitute the base of food webs in these environments and are important for maintaining a functioning lotic ecosystem. While microbial communities of rivers dominated by fine-grained sediments are relatively well studied, little is known about the structure and seasonal dynamics of microbial communities inhabiting the predominantly gravel and cobble hyporheic zones of rivers of the western United States. Here, we present the first molecular analysis of hyporheic microbial communities of three different stream types (based on mean base discharge, substratum type, and drainage area), in Montana. Utilizing 16S rDNA phylogeny, DGGE pattern analysis, and qPCR, we have analyzed the prokaryotic communities living on the 1.7 to 2.36 mm grain-size fraction of hyporheic sediments from three separate riffles in each stream. DGGE analysis showed clear seasonal community patterns, indicated similar community composition between different riffles within a stream (95.6-96.6% similarity), and allowed differentiation between communities in different streams. Each river supported a unique complement of species; however, several phylogenetic groups were conserved between all three streams including Pseudomonads and members of the genera Aquabacterium, Rhodoferax, Hyphomicrobium, and Pirellula. Each group showed pronounced seasonal trends in abundance, with peaks during the Fall. The Hyphomicrobium group was numerically dominant throughout the year in all three streams. This work provides a framework for investigating the effects of various environmental factors and anthropogenic effects on microbial communities inhabiting the hyporheic zone.

Anaphase-promoting complex/cyclosome-dependent proteolysis of human cyclin A starts at the beginning of mitosis and is not subject to the spindle assembly checkpoint.

Cyclin A is a stable protein in S and G2 phases, but is destabilized when cells enter mitosis and is almost completely degraded before the metaphase to anaphase transition. Microinjection of antibodies against subunits of the anaphase-promoting complex/cyclosome (APC/C) or against human Cdc20 (fizzy) arrested cells at metaphase and stabilized both cyclins A and B1. Cyclin A was efficiently polyubiquitylated by Cdc20 or Cdh1-activated APC/C in vitro, but in contrast to cyclin B1, the proteolysis of cyclin A was not delayed by the spindle assembly checkpoint. The degradation of cyclin B1 was accelerated by inhibition of the spindle assembly checkpoint. These data suggest that the APC/C is activated as cells enter mitosis and immediately targets cyclin A for degradation, whereas the spindle assembly checkpoint delays the degradation of cyclin B1 until the metaphase to anaphase transition. The "destruction box" (D-box) of cyclin A is 10-20 residues longer than that of cyclin B. Overexpression of wild-type cyclin A delayed the metaphase to anaphase transition, whereas expression of cyclin A mutants lacking a D-box arrested cells in anaphase.

Characterization of adriamycin-induced G2 arrest and its abrogation by caffeine in FL-amnion cells with or without p53.

We investigated the effect of Adriamycin on FL-amnion (FL) cells. After treatment with the drug, the cells arrested at G2, but we did not detect an increase in the p21 levels. We established a p53-deficient derivative of these cells, in which G2 arrest also occurred after treatment with Adriamycin, suggesting that the arrest we observed in these cells is independent of the p53 pathway. Low doses of Adriamycin (100-200 ng/ml) induced G2 arrest, while late S-phase arrest was observed at high doses (500-1000 ng/ml) in both FL and p53-deficient FL cells. Accumulation of cyclin B1 was detected only in cells arrested at G2, and not in those arrested at S phase, suggesting that the S-phase checkpoint functioned efficiently even in p53-deficient FL cells. In both cell lines, caffeine-induced activation of CDC2 kinase was detected only in cells arrested at G2 and CDC2 kinase-activated cells died exhibiting features of apoptosis. CDC2 kinase activation was inhibited by cycloheximide. Furthermore, cycloheximide inhibited activation of CDK2:cyclin A, which normally precedes CDC2 kinase activation in caffeine-treated cells. These results suggest that p53 and p21 do not have special roles in the S- and G2-phase checkpoints and that CDK2:cyclin A could be the target of the G2-phase DNA damage checkpoint.

Colonic motor function in humans is not affected by gender.

Functional abdominal pain, including the irritable bowel syndrome, is more common in females. Our aim was to determine if differences in motility or biomechanical properties of the colon could account for this gender difference. In 18 healthy subjects (nine males), a catheter assembly incorporating a balloon and perfused side holes, connected to a barostat, was positioned in the left colon. The system was used to determine compliance, sensation in response to phasic balloon distension, and changes in motor activity and tone in response to a meal. There was no significant difference in any of these variables between males and females. We conclude that there is no gender difference in colonic motor function or sensation to balloon distension. The increased prevalence of irritable bowel syndrome in females may be related to psychosocial factors rather than differences in colonic motor function.

L-Carnitine supplementation combined with aerobic training does not promote weight loss in moderately obese women.

L-Carnitine (L-C) transports fatty acids into mitochondria for oxidation and is marketed as a weight loss supplement. In a double-blind investigation to test the weight loss efficacy of L-C, 36 moderately overweight premenopausal women were pair matched on Body Mass Index (BMI) and randomly assigned to two groups (N = 18). For 8 weeks the L-C group ingested 2 g twice daily of L-C, while the placebo (P) group ingested the same amount of lactose. All subjects walked for 30 min (60-70% maximum heart rate) 4 days/week. Body composition, resting energy expenditure (REE) and substrate utilization were estimated before and after treatment. For the subjects who completed the study (15 P, 13 L-C), no significant changes in mean total body mass (TBM), fat mass FM, and resting lipid utilization occurred over time, nor were there any significant differences between groups for any variable. Conversely REE increased significantly for all subjects, but no between group differences existed. Five of the L-C group experienced nausea or diarrhea and consequently did not complete the study. Eight weeks of L-C ingestion and walking did not significantly alter the TBM or FM of overweight women, thereby casting doubt on the efficacy of L-C supplementation for weight loss.