Thapsigargin and receptor-mediated activation of Drosophila TRPL channels stably expressed in a Drosophila S2 cell line

The Drosophila melanogaster genes, transient receptor potential (trp) and transient receptor potential-like (trpl) encode putative plasma membrane cation channels TRP and TRPL, respectively. We have stably co-expressed Drosophila TRPL with a Drosophila muscarinic acetylcholine receptor (DM1) in a Drosophila cell line (S2 cells). Basal Ca2+ levels measured using Fura-2/AM in unstimulated S2-DM1-TRPL cells were low and indistinguishable from untransfected cells, indicating that the TRPL channels were not constitutively active in this expression system. Activation of DM1 receptor in S2-DM1-TRPL cells by 100 microM carbamylcholine induced Ca2+ release from an intracellular Ca2+ pool followed by a Gd(3+)-insensitive Ca2+ influx. Pretreatment of S2-DM1-TRPL cells with 10 microM atropine abolished Gd(3+)-insensitive Ca2+ influx triggered by carbamylcholine, but the response was not blocked by prior incubation with pertussis toxin. TRPL channels could also be reliably activated by bath application of 1 microM thapsigargin for 10 min or 100 nM thapsigargin for 60 min in Ca(2+)-free solution. In some cells, TRPL channels activated by thapsigargin could further be activated by carbamylcholine. The findings suggest that, when stably expressed in the S2 cell line, TRPL may be regulated by two distinct mechanisms: (i) store depletion; and (ii) stimulation of DM1 receptor via pertussis-toxin insensitive G-protein (or the subsequent activation of PLC), but without further requirement for Ca2+ release.     

Structure of tetrameric human phenylalanine hydroxylase and its implications for phenylketonuria

Phenylalanine hydroxylase (PheOH) catalyzes the conversion of L-phenylalanine to L-tyrosine, the rate-limiting step in the oxidative degradation of phenylalanine. Mutations in the human PheOH gene cause phenylketonuria, a common autosomal recessive metabolic disorder that in untreated patients often results in varying degrees of mental retardation. We have determined the crystal structure of human PheOH (residues 118-452). The enzyme crystallizes as a tetramer with each monomer consisting of a catalytic and a tetramerization domain. The tetramerization domain is characterized by the presence of a domain swapping arm that interacts with the other monomers forming an antiparallel coiled-coil. The structure is the first report of a tetrameric PheOH and displays an overall architecture similar to that of the functionally related tyrosine hydroxylase. In contrast to the tyrosine hydroxylase tetramer structure, a very pronounced asymmetry is observed in the phenylalanine hydroxylase, caused by the occurrence of two alternate conformations in the hinge region that leads to the coiled-coil helix. Examination of the mutations causing PKU shows that some of the most frequent mutations are located at the interface of the catalytic and tetramerization domains. Their effects on the structural and cellular stability of the enzyme are discussed.     

Intrathyroidal parathyroid glands can be a cause of failed cervical exploration for hyperparathyroidism

BACKGROUND: The incidence of intrathyroidal parathyroid glands remains controversial. The purpose of this study was to determine the incidence in a series of patients with hyperparathyroidism. METHODS: Three hundred nine patients underwent parathyroidectomy. Patients were divided into two groups: uniglandular disease versus hyperplasia. RESULTS: Eighteen of 309 patients (6%) had abnormal intrathyroidal parathyroid glands. The incidence was 3% (7 of 222) in patients with uniglandular disease versus 15% (11 of 73) in those with hyperplasia. With a mean follow-up of 54 months, 12 patients are eucalcemic, 5 have persistent hypocalcemia, and 1 has recurrent hypercalcemia. There were no recurrent laryngeal nerve injuries. CONCLUSIONS: These data suggest that an intrathyroidal adenoma is an uncommon cause of failure, whereas abnormal intrathyroidal parathyroid tissue may be a more common cause of failure in patients with hyperplasia.     

Free amino acid supplementation to steers: effects on ruminal fermentation and performance

Three studies were conducted to evaluate amino acid utilization by cattle. In Exp. 1, five steers (580 kg) were fed 86% rolled corn diets with mixtures of amino acids containing up to 6 g/d DL-Met, 24 g/d L-Lys, 6 g/d L-Thr, and 3 g/d L-Trp. Treatments had little effect on ruminal fermentation, diet digestibility, N flow to the duodenum, or microbial efficiency. Ruminal concentrations of Met and Lys increased linearly (P < .05) with amino acid supplementation, whereas Thr responded quadratically, and Trp was not altered. In Exp. 2, four steers (414 kg) were used to measure effects of dietary monensin or laidlomycin propionate in high-grain diets supplemented with amino acids. Ionophores had no significant effect on ruminal fermentation or outflows of amino acids from the rumen. In Exp. 3, 100 steers (287 kg initial BW) were fed diets containing 1% of a nonprotein N source. Treatments were 1) no supplemental N (UREA), 2) UREA plus soybean meal (SBM), 3) UREA plus 2 g/d DL-Met, 8 g/d L-Lys, 2 g/d L-Thr, and 1 g/d L-Trp, or 4) UREA plus 4 g/d DL-Met, 16 g/d L-Lys, 4 g/d L-Thr, and 2 g/d L-Trp. During the growing period (diets based on whole-plant milo silage), gains were higher for SBM-supplemented steers than for UREA steers and intermediate for steers supplemented with amino acids. Few significant differences in performance were observed among treatments during the finishing phase (diets based on dry-rolled corn) or for the entire experiment, but cattle fed SBM or amino acids tended to be fatter and have better marbling scores and quality grades. Amino acids did not greatly alter ruminal fermentation or cattle performance.     

Numerical Spray Model of the Fluidized Bed Coating Process

In this study, a new model for the batch top-spray fluidized bed coating process is presented. The model is based on the one-dimensional (axial) discretization of the bed volume into different control volumes, in which the dynamic heat and mass balances for air, water vapor, droplets, core particles, and coating material were established. The coupling of the droplet phase's mass and heat transfer terms with the gas and solid phases was established by means of a droplet submodel in which droplet trajectories were individually simulated.

The model calculation method combines a Monte Carlo technique for the simulation of the particle exchange with the first-order Euler's method for solving the heat and mass balances, enabling the prediction of both the dynamic coating mass distribution and the one-dimensional (axial) thermodynamic behavior of the fluidized bed during batch operation. The simulation results were validated using experimental two-dimensional spatial air temperature and air humidity distributions, which were measured in a fluidized bed pilot reactor using a scanning probe.

Sensitivity analysis was carried out to study the effect of controllable process variables, such as fluidization air and atomization air properties, as well as the properties of the spraying liquid upon the simulated dynamic temperature and humidity distributions. Also, the effects of relevant process variables on growth rate uniformity and process yield were studied. Based on these sensitivity studies it was concluded that nozzle parameters, such as air pressure and positioning with respect to the bed, are as important as the fluidization air properties (humidity, temperature, and flow rate) for the coating growth rate uniformity and process yield.     

Synthesis and Evaluation of New Thiodigalactoside‐Based Chemical Probes to Label Galectin‐3

Light up galectin: Photoprobes based on thiodigalactoside were prepared for galectin‐3, a lectin linked to cancer. The probes contained either benzophenone or acetophenone moieties as the photolabel for covalent attachment to the protein. One particular probe labeled galectin‐3 selectively, even in the presence of cell lysate.

     

Leveling up and down: The experiences of benign and malicious envy.

Envy is the painful emotion caused by the good fortune of others. This research empirically supports the distinction between two qualitatively different types of envy, namely benign and malicious envy. It reveals that the experience of benign envy leads to a moving-up motivation aimed at improving one’s own position, whereas the experience of malicious envy leads to a pulling-down motivation aimed at damaging the position of the superior other. Study 1 used guided recall of the two envy types in a culture (the Netherlands) that has separate words for benign and malicious envy. Analyses of the experiential content of these emotions found the predicted differences. Study 2 and 3 used one sample from the United States and one from Spain, respectively, where a single word exists for both envy types. A latent class analysis based on the experiential content of envy confirmed the existence of separate experiences of benign and malicious envy in both these cultures as well. The authors discuss the implications of distinguishing the two envy types for theories of cooperation, group performance, and Schadenfreude. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neonatal hypocalcemia mechanism of occurrence and management

Early neonatal hypocalcemia occurs in premature infants, infants with birth asphyxia, and infants of diabetic mothers. Etiological considerations include decreased calcium (Ca) supply, increased endogenous phosphate load, hypomagnesemia, alkali therapy, functional hypoparathyroidism, defects in vitamin D metabolism, and possibly calcitonin excess. Late neonatal hypocalcemia occurs, with malabsorption of magnesium (Mg), increased exogenous phosphate loading, after alkali therapy of diarrheal acidosis, hypoparathyroidism, and vitamin D related disorders. The therapy of hypocalcemia includes oral or iv Ca salts and in the near future, possibly the newly discovered vitamin D metabolites.     

The effects of steroid instillations and hematomas on the pseudosheaths around miniature breast implants in rats

The syndrome of hypercalcemia in patients with renal cell carcinoma without metastasis to bone, in association with elevated levels of immunoreactive prostaglandin E and normal parathyroid hormone levels, prompted the investigation of an etiologic relationship of increased prostaglandin in this syndrome. Ethyl acetate extracts of tissue culture effluents, primary and metastatic renal cell carcinoma, and plasma were chromatographed on silicic acid columns and assayed by double antibody immunoprecipitative methods for immunoprecipitative methods for immunoreactive prostaglandins A and E. Increased levels of immunoreactive prostaglandins A and E were found 1) to be generated in parallel with cell growth during a period of time by renal cell carcinoma in monolayer growth, 2) in extracts of primary and metastatic renal cell carcinoma tissue and 3) in the venous effluent of a kidney bearing a renal cell carcinoma. These findings support the hypothesis that renal cell carcinoma can produce prostaglandins. Furthermore, reported syndromes of patients with renal cell carcinoma associated with elevated prostaglandin levels may result from the autonomous production of prostaglandins in vivo by the tumor.