227 research outputs found

    Identification of a novel loss-of-function PHEX mutation, Ala720Ser, in a sporadic case of adult-onset hypophosphatemic osteomalacia

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    Adults presenting with sporadic hypophosphatemia and elevations in circulating fibroblast growth factor-23 (FGF23) concentrations are usually investigated for an acquired disorder of FGF23 excess such as tumor induced osteomalacia (TIO). However, in some cases the underlying tumor is not detected, and such patients may harbor other causes of FGF23 excess. Indeed, coding-region and 3’UTR mutations of phosphate-regulating neutral endopeptidase (PHEX), which encodes a cell-surface protein that regulates circulating FGF23 concentrations, can lead to alterations in phosphate homeostasis, which are not detected until adulthood. Here, we report an adult female who presented with hypophosphatemic osteomalacia and raised serum FGF23 concentrations. The patient and her parents, who were her only first-degree relatives, had no history of rickets. The patient was thus suspected of having TIO. However, no tumor had been identified following extensive localization studies. Mutational analysis of the PHEX coding-region and 3’UTR was undertaken, and this revealed the patient to be heterozygous for a novel germline PHEX mutation (c.2158G>T; p.Ala720Ser). In vitro studies involving the expression of WT and mutant PHEX proteins in HEK293 cells demonstrated the Ala720Ser mutation to impair trafficking of PHEX, with 80% cell surface expression for WT PHEX (p<0.05). Thus, our studies have identified a pathogenic PHEX mutation in a sporadic case of adult-onset hypophosphatemic osteomalacia, and these findings highlight a role for PHEX gene analysis in some cases of suspected TIO, particularly when no tumor has been identified

    Caspase-3 dependent nitrergic neuronal apoptosis following cavernous nerve injury is mediated via RhoA and ROCK activation in major pelvic ganglion

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    Axonal injury due to prostatectomy leads to Wallerian degeneration of the cavernous nerve (CN) and erectile dysfunction (ED). Return of potency is dependent on axonal regeneration and reinnervation of the penis. Following CN injury (CNI), RhoA and Rho-associated protein kinase (ROCK) increase in penile endothelial and smooth muscle cells. Previous studies indicate that nerve regeneration is hampered by activation of RhoA/ROCK pathway. We evaluated the role of RhoA/ROCK pathway in CN regulation following CNI using a validated rat model. CNI upregulated gene and protein expression of RhoA/ROCK and caspase-3 mediated apoptosis in the major pelvic ganglion (MPG). ROCK inhibitor (ROCK-I) prevented upregulation of RhoA/ROCK pathway as well as activation of caspase-3 in the MPG. Following CNI, there was decrease in the dimer to monomer ratio of neuronal nitric oxide synthase (nNOS) protein and lowered NOS activity in the MPG, which were prevented by ROCK-I. CNI lowered intracavernous pressure and impaired non-adrenergic non-cholinergic-mediated relaxation in the penis, consistent with ED. ROCK-I maintained the intracavernous pressure and non-adrenergic non-cholinergic-mediated relaxation in the penis following CNI. These results suggest that activation of RhoA/ROCK pathway mediates caspase-3 dependent apoptosis of nitrergic neurons in the MPG following CNI and that ROCK-I can prevent post-prostatectomy ED

    Entrepreneurial sons, patriarchy and the Colonels' experiment in Thessaly, rural Greece

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    Existing studies within the field of institutional entrepreneurship explore how entrepreneurs influence change in economic institutions. This paper turns the attention of scholarly inquiry on the antecedents of deinstitutionalization and more specifically, the influence of entrepreneurship in shaping social institutions such as patriarchy. The paper draws from the findings of ethnographic work in two Greek lowland village communities during the military Dictatorship (1967–1974). Paradoxically this era associated with the spread of mechanization, cheap credit, revaluation of labour and clear means-ends relations, signalled entrepreneurial sons’ individuated dissent and activism who were now able to question the Patriarch’s authority, recognize opportunities and act as unintentional agents of deinstitutionalization. A ‘different’ model of institutional change is presented here, where politics intersects with entrepreneurs, in changing social institutions. This model discusses the external drivers of institutional atrophy and how handling dissensus (and its varieties over historical time) is instrumental in enabling institutional entrepreneurship

    The response of leptin, interleukin-6 and fat oxidation to feeding in weight-losing patients with pancreatic cancer

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    At baseline, weight-losing pancreatic cancer patients (n=7) had lower leptin (P&#60;0.05) but higher cortisol, interleukin-6, resting energy expenditure and fat oxidation than healthy subjects (n=6, P&lt;0.05). Over a 4 h feeding period, the areas under the curve for glucose, cortisol and interleukin-6 were greater (P&#60;0.05), but less for leptin in the cancer group (P&#60;0.05). Therefore, it would appear that low leptin concentrations, increased fat oxidation and insulin resistance are associated with increased concentrations of cortisol and interleukin-6 in weight-losing patients with pancreatic cancer

    A prospective randomized study of megestrol acetate and ibuprofen in gastrointestinal cancer patients with weight loss

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    The use of megestrol acetate in the treatment of weight loss in gastrointestinal cancer patients has been disappointing. The aim of the present study was to compare the combination of megestrol acetate and placebo with megestrol acetate and ibuprofen in the treatment of weight loss in such patients. At baseline, 4–6 weeks and 12 weeks, patients underwent measurements of anthropometry, concentrations of albumin and C-reactive protein and assessment of appetite, performance status and quality of life using EuroQol-EQ-5D and EORTC QLQ-C30. Thirty-eight and 35 patients (median weight loss 18%) were randomized to megestrol acetate/placebo or megestrol acetate/ibuprofen, respectively, for 12 weeks. Forty-six (63%) of patients failed to complete the 12-week assessment. Of those evaluable at 12 weeks, there was a decrease in weight (median 2.8 kg) in the megestrol acetate/placebo group compared with an increase (median 2.3 kg) in the megestrol acetate/ibuprofen group (P < 0.001). There was also an improvement in the EuroQol-EQ-5D quality of life scores of the latter group (P < 0.05). The combination of megestrol acetate/ibuprofen appeared to reverse weight loss and appeared to improve quality of life in patients with advanced gastrointestinal cancer. Further trials of this novel regimen in weight-losing patients with hormone-insensitive cancers are warranted. © 1999 Cancer Research Campaig

    Reduced total energy expenditure and physical activity in cachectic patients with pancreatic cancer can be modulated by an energy and protein dense oral supplement enriched with n-3 fatty acids

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    The aim of the study was to assess the total energy expenditure (TEE), resting energy expenditure (REE) and physical activity level (PAL) in home-living cachectic patients with advanced pancreatic cancer. The influence of an energy and protein dense oral supplement either enriched with or without the n-3 fatty acid eicosapentaenoic acid (EPA) and administered over an 8-week period was also determined. In total, 24 patients were studied at baseline. The total energy expenditure was measured using doubly labelled water and REE determined by indirect calorimetry. Patients were studied at baseline and then randomised to either oral nutritional supplement. Measurements were repeated at 8 weeks. At baseline, REE was increased compared with predicted values for healthy individuals (1387(42) vs 1268(32) kcal day-1, P=0.001), but TEE (1732(82) vs 1903(48) kcal day-1, P=0.023) and PAL (1.24(0.04) vs 1.50) were reduced. After 8 weeks, the REE, TEE and PAL of patients who received the control supplement did not change significantly. In contrast, although REE did not change, TEE and PAL increased significantly in those who received the n-3 (EPA) enriched supplement. In summary, patients with advanced pancreatic cancer were hypermetabolic. However, TEE was reduced and this was secondary to a reduction in physical activity. The control energy and protein dense oral supplement did not influence the physical activity component of TEE. In contrast, administration of the supplement enriched with EPA was associated with an increase in physical activity, which may reflect improved quality of life

    Early severe inflammatory responses to uropathogenic E. coli predispose to chronic and recurrent urinary tract infection

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    Chronic infections are an increasing problem due to the aging population and the increase in antibiotic resistant organisms. Therefore, understanding the host-pathogen interactions that result in chronic infection is of great importance. Here, we investigate the molecular basis of chronic bacterial cystitis. We establish that introduction of uropathogenic E. coli (UPEC) into the bladders of C3H mice results in two distinct disease outcomes: resolution of acute infection or development of chronic cystitis lasting months. The incidence of chronic cystitis is both host strain and infectious dose-dependent. Further, development of chronic cystitis is preceded by biomarkers of local and systemic acute inflammation at 24 hours post-infection, including severe pyuria and bladder inflammation with mucosal injury, and a distinct serum cytokine signature consisting of elevated IL-5, IL-6, G-CSF, and the IL-8 analog KC. Mice deficient in TLR4 signaling or lymphocytes lack these innate responses and are resistant, to varying degrees, to developing chronic cystitis. Treatment of C3H mice with the glucocorticoid anti-inflammatory drug dexamethasone prior to UPEC infection also suppresses the development of chronic cystitis. Finally, individuals with a history of chronic cystitis, lasting at least 14 days, are significantly more susceptible to redeveloping severe, chronic cystitis upon bacterial challenge. Thus, we have discovered that the development of chronic cystitis in C3H mice by UPEC is facilitated by severe acute inflammatory responses early in infection, which subsequently are predisposing to recurrent cystitis, an insidious problem in women. Overall, these results have significant implications for our understanding of how early host-pathogen interactions at the mucosal surface determines the fate of disease

    Validity of the Falls Risk for Older People in the Community (FROP‑Com) tool to predict falls and fall injuries for older people presenting to the emergency department after falling

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    The aims of this study were to (1) externally validate the accuracy of the Falls Risk for Older People in the Community (FROP-Com) falls risk assessment tool in predicting falls and (2) undertake initial validation of the accuracy of the FROPCom to predict injurious falls (requiring medical attention) in people aged ≥ 60 years presenting to emergency departments (EDs) after falling. Two hundred and thirteen participants (mean age = 72.4 years; 59.2% women) were recruited (control group of a randomised controlled trial). A FROP-Com assessment was completed at a home visit within 2 weeks of ED discharge. Data on falls and injurious falls requiring medical attention were collected via monthly falls calendars for the next 12 months. Predictive accuracy was evaluated using sensitivity and specificity of a high-risk FROP-Com classification (score ≥ 19) in predicting a fall and injurious falls requiring medical attention. Fifty per cent of participants fell, with 60.4% of falls requiring medical attention. Thirty-two per cent were classified as high, 49% as moderate and 19% low falls risk. Low sensitivity was achieved for the FROP-Com high-risk classification for predicting falls (43.4%) and injurious falls (34.4%), although specificity was high (79.4% and 78.6%, respectively). Despite the FROP-Com’s low predictive accuracy, the high fall rate and high falls risk of the sample suggest that older people who fall, present to ED and are discharged home are at high risk of future falls. In high-falls-risk populations such as in this study, the FROP-Com is not a valid tool for classifying risk of falls or injurious falls. Its potential value may instead be in identifying risk factors for falling to direct tailoring of falls prevention interventions to reduce future falls

    Reduced Proliferation in the Adult Mouse Subventricular Zone Increases Survival of Olfactory Bulb Interneurons

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    Neurogenesis in the adult brain is largely restricted to the subependymal zone (SVZ) of the lateral ventricle, olfactory bulb (OB) and the dentate subgranular zone, and survival of adult-born cells in the OB is influenced by factors including sensory experience. We examined, in mice, whether survival of adult-born cells is also regulated by the rate of precursor proliferation in the SVZ. Precursor proliferation was decreased by depleting the SVZ of dopamine after lesioning dopamine neurons in the substantia nigra compacta with 6-hydroxydopamine. Subsequently, we examined the effect of reduced SVZ proliferation on the generation, migration and survival of neuroblasts and mature adult-born cells in the SVZ, rostral migratory stream (RMS) and OB. Proliferating cells in the SVZ, measured by 5-bromo-2-deoxyuridine (BrdU) injected 2 hours prior to death or by immunoreactivity against Ki67, were reduced by 47% or 36%, respectively, 7 days after dopamine depletion, and by 29% or 31% 42 days after dopamine depletion, compared to sham-treated animals. Neuroblast generation in the SVZ and their migration along the RMS were not affected, neither 7 nor 42 days after the 6-hydroxydopamine injection, since the number of doublecortin-immunoreactive neuroblasts in the SVZ and RMS, as well as the number of neuronal nuclei-immunoreactive cells in the OB, were stable compared to control. However, survival analysis 15 days after 6-hydroxydopamine and 6 days after BrdU injections showed that the number of BrdU+ cells in the SVZ was 70% higher. Also, 42 days after 6-hydroxydopamine and 30 days after BrdU injections, we found an 82% increase in co-labeled BrdU+/γ-aminobutyric acid-immunoreactive cell bodies in the granular cell layer, while double-labeled BrdU+/tyrosine hydroxylase-immunoreactive cell bodies in the glomerular layer increased by 148%. We conclude that the number of OB interneurons following reduced SVZ proliferation is maintained through an increased survival of adult-born precursor cells, neuroblasts and interneurons
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