Dynamic stall modelling of the S809 aerofoil and comparison with experiments

An analysis of dynamic stall for the S809 aerofoil has been performed in conjunction with the Leishman–Beddoes dynamic stall model that was modified for wind turbine applications. Numerical predictions of the lift, drag and pitching moment coefficients were compared with measurements obtained for an oscillating S809 aerofoil at various reduced frequencies, mean angles of attack and angle of attack amplitudes. It was found that the results using the modified model were in good agreement with the experimental data. Hysteresis in the aerodynamic coefficients was captured well, although the drag coefficient was slightly underpredicted in the deep stall flow regime. Validation against the experimental data showed overall good agreement. The mathematical structure of the model is such that it can be readily incorporated into a comprehensive analysis code for a wind turbine. Copyright © 2006 John Wiley & Sons, Ltd.     

Parathyroidectomy in Maryland: effects of an endocrine center

BACKGROUND: Surgery for hyperparathyroidism is associated with high cure rates and low morbidity and mortality when performed by experienced surgeons. We wanted to determine whether referral of patients with hyperparathyroidism to an endocrine surgery center has an impact on patient outcomes and costs. METHODS: Data from 901 patients who underwent parathyroidectomy recorded in the Maryland inpatient discharge database between 1990 and 1994 at 52 hospitals were compared with 169 consecutive patients who underwent surgical exploration by one surgeon (R.U.) at the Johns Hopkins Hospital. RESULTS: Although in 47 of 52 hospitals fewer than 10 parathyroidectomies were performed each year, in these hospitals four of five related deaths occurred before patient discharge. The percentage of parathyroidectomies in Maryland performed by one endocrine surgeon has increased from 8% in 1990 to 21% in 1994 and is associated with a 97% cure rate and no mortality. Moreover, while hospital length of stay (LOS) in the state has decreased from 7 to 3.1 days, LOS for the high-volume provider has declined to a mean of 1.3 days. CONCLUSIONS: Patients with hyperparathyroidism are increasingly referred to an endocrine surgery center, which results in a high cure rate, low morbidity, no mortality, and a shorter LOS. Improved surgical outcomes and lower costs depend on an experienced surgeon and argue for the referral of these patients to endocrine surgery centers.     

Identification of sites required for down-regulation of Na+/H+ exchanger NHE3 activity by cAMP-dependent protein kinase. phosphorylation-dependent and -independent mechanisms

We recently identified a region within the cytoplasmic C-terminal tail of the Na+/H+ exchanger NHE3 isoform (residues 579 to 684) which is essential for inhibition of transport activity by cAMP-dependent protein kinase (PKA) (Cabado, A. G., Yu, F. H., Kapus, A., Gergely, L., Grinstein, S., and Orlowski, J. (1996) J. Biol. Chem. 271, 3590-3599). To further define determinants of PKA regulation, six serine residues located in potential recognition sequences for PKA within, or adjacent to, this region (positions 552, 605, 634, 661, 690, and 691) were altered either independently or in various combinations using site-directed mutagenesis. Wild type and mutant NHE3s tagged with the influenza virus hemagglutinin epitope were stably expressed in exchanger-deficient Chinese hamster ovary cells (AP-1) for functional studies. Of the individual mutations examined, only substitutions at Ser605 or Ser634 affected sensitivity to forskolin, an activator of adenylate cyclase, although partial inhibition of NHE3 activity by forskolin remained. By contrast, simultaneous mutation of both these serines completely abolished cAMP-mediated inhibition of NHE3 without greatly affecting basal transport activity. Two-dimensional analysis of tryptic digests of immunoprecipitated NHE3 labeled in vivo with [32P]orthophosphate revealed several phosphopeptides under basal conditions. Phosphorylation was increased approximately 3-fold in one of these peptides following forskolin treatment, and this change was eliminated by mutation of residue Ser605. Thus, phosphorylation of Ser605 is essential for cAMP-mediated inhibition of NHE3. In addition, Ser634 is also required for the effect of cAMP, even though this residue does not become phosphorylated upon activation of PKA.     

Evidence that the TRH-like peptide pyroglutamyl-glutamyl-prolineamide in human serum may not be secreted by the pituitary gland

A prospective, randomized, placebo-controlled, double-blind, parallel-group, 6-month study assessed the efficacy and safety of ropinirole, a nonergoline D2-dopamine agonist, in patients with early Parkinson's disease (n = 241; Hoehn & Yahr stages I to III) with limited or no prior dopaminergic therapy. Patients (mean age, 62.8 years), stratified by concomitant use of selegiline, were randomized to ropinirole (n = 116) or placebo (n = 125). The starting dose of ropinirole was 0.25 mg tid with titration to at least 1.5 mg tid (maximum dose, 8 mg tid). Primary efficacy endpoint was the percentage improvement in Unified Parkinson's Disease Rating Scale (UPDRS) motor score. Ropinirole-treated patients had a significantly greater percentage improvement in UPDRS motor score than patients who received placebo (+24% vs -3%; p < 0.001). Ropinirole was well tolerated and patient withdrawals were infrequent. Most adverse experiences were related to peripheral dopaminergic activity. Ropinirole monotherapy is an effective and well-tolerated therapeutic option for treatment of early Parkinson's disease.     

Agonistic activity of a CD40-specific single-chain Fv constructed from the variable regions of mAb G28-5

A single-chain Fv (sFv) was expressed from the variable regions of the CD40-specific mAb G28-5. The molecule bound CD40 with a high affinity (2.2 nM) and was a monomer in solution. Surprisingly, G28-5 sFv was a potent CD40 agonist that rapidly crosslinked CD40 on the cell surface but did not crosslink CD40-Ig in solution. G28-5 sFv was a more potent agonist than G28-5 IgG and was able to stimulate CD40 responses by B cells and monocytes. G28-5 IgG partially blocked, whereas G28-5 sFv augmented CD40 responses during stimulation with natural ligand (gp39-CD8 fusion protein). These results indicate that the functional activity of ligands built from the binding site of G28-5 is highly dependent upon the size and physical properties of the molecule both in solution and on the cell surfaces.     

Dose-dependent effects of 17-beta-estradiol on pituitary thyrotropin content and secretion in vitro

We studied the basal and thyrotropin-releasing hormone (TRH) (50 nM) induced thyrotropin (TSH) release in isolated hemipituitaries of ovariectomized rats treated with near-physiological or high doses of 17-beta-estradiol benzoate (EB; sc, daily for 10 days) or with vehicle (untreated control rats, OVX). One group was sham-operated (normal control). The anterior pituitary glands were incubated in Krebs-Ringer bicarbonate medium, pH 7.4, at 37 degrees C in an atmosphere of 95% O2/5% CO2. Medium and pituitary TSH was measured by specific RIA (NIDDK-RP-3). Ovariectomy induced a decrease (P < 0.05) in basal TSH release (normal control = 44.1 +/- 7.2; OVX = 14.7 +/- 3.0 ng/ml) and tended to reduce TRH-stimulated TSH release (normal control = 33.0 +/- 8.1; OVX = 16.6 +/- 2.4 ng/ml). The lowest dose of EB (0.7 microgram/100 g body weight) did not reverse this alteration, but markedly increased the pituitary TSH content (0.6 +/- 0.06 microgram/hemipituitary; P < 0.05) above that of OVX (0.4 +/- 0.03 microgram/hemipituitary) and normal rats (0.46 +/- 0.03 microgram/hemipituitary). The intermediate EB dose (1.4 micrograms/100 g body weight) induced a nonsignificant tendency to a higher TSH response to TRH compared to OVX and a lower response compared to normal rats. Conversely, in the rats treated with the highest dose (14 micrograms/100 g body weight), serum 17-beta-estradiol was 17 times higher than normal, and the basal and TRH-stimulated TSH release, as well as the pituitary TSH content, was significantly (P < 0.05) reduced compared to normal rats and tended to be even lower than the values observed for the vehicle-treated OVX group, suggesting an inhibitory effect of hyperestrogenism. In conclusion, while reinforcing the concept of a positive physiological regulatory role of estradiol on the TSH response to TRH and on the pituitary stores of the hormone, the present results suggest an inhibitory effect of high levels of estrogen on these responses.     

Accuracy of an electromagnetic measurement device and application to the measurement and description of knee joint motion

A nonsteroidal antiinflammatory drug, 5-bromo-2-(4-fluorophenyl)-3-(4-methylsulfonylphenyl) thiophene (BFMeT), induced ileal ulcers in rats after oral administration, while no ulcers were observed after subcutaneous injection. The ileal ulcer formation in BFMeT-treated rats was examined to correlate the administration of cultures of Lactobacillus acidophilus or Bifidobacterium adolescentis with intestinal bacteria in the ileal contents and lipid peroxidation of the small intestinal mucosa. Ileal ulcers were observed in more than 85% of the rats treated with BFMeT at a dose of 1,000 mg/kg when they were given tap water as drinking water. The incidence of ulcer formation was repressed by giving culture supernatants of L. acidophilus or B. adolescentis as drinking water, but not by giving the cell suspension as drinking water. Gram staining of the ileal contents of normal rats revealed that 97% of the stained bacteria were gram-positive rods and only 1.5% were gram-negative rods. The percentage of gram-negative rods 72 hr after BFMeT administration was 49.8% and increased over 30-fold in BFMeT-treated rats. However, the percentage of gram-negative rods was 9.7 % or 16%, respectively, in rats taking culture supernatants of L acidophilus or B. adolescentis. In addition, thiobarbituric acid-reactive substances in the ileal mucosa increased significantly in the rats given tap water for 72 hr after BFMeT treatment, but not in rats given the culture supernatants of L. acidophilus or B. adolescentis. Since BFMeT induced an unbalanced intestinal microflora, the effect of antibiotic treatment on ulcer formation in rats was examined. The magnitude of the ulcer formation in the antibiotic-treated rats was, in decreasing order, metronidazole >none > kanamycin > a mixture (bacitracin, neomycin and streptomycin). These results suggest that the intestinal microflora plays an important role in ulcer formation and that a metabolite(s) of L. acidophilus and B. adolescentis inhibits ileal ulcer formation by repressing changes in the intestinal microflora and lipid peroxidation in BFMeT-treated rats.     

More hippocampal neurons in adult mice living in an enriched environment

Neurogenesis occurs in the dentate gyrus of the hippocampus throughout the life of a rodent, but the function of these new neurons and the mechanisms that regulate their birth are unknown. Here we show that significantly more new neurons exist in the dentate gyrus of mice exposed to an enriched environment compared with littermates housed in standard cages. We also show, using unbiased stereology, that the enriched mice have a larger hippocampal granule cell layer and 15 per cent more granule cell neurons in the dentate gyrus.