Effect of profound hearing loss on a central auditory nucleus

The present study was designed to investigate the type and extent of degeneration occurring in the human central auditory system subsequent to profound hearing loss. The authors have examined the size of one population of neurons in the ventral cochlear nucleus in seven subjects with profound hearing loss (audiometric responses poorer than 90-100 dB HL). Six normal subjects, ages 35-78, were used as controls. Cell size in the hearing-impaired subjects ranged from normal to reduced by more than 50 percent. Two factors appear to contribute to the variability in cell size reduction. The correlation coefficient (Spearman rs) of cell size with duration of profound deafness was -0.48, indicating a moderate tendency for neurons to become smaller with longer periods of deafness. The correlation coefficient of cell size with number of surviving cochlear ganglion cells was 0.73, indicating a stronger tendency for neurons to be larger with greater eighth nerve innervation of the cochlear nucleus. Two cases of Scheibe degeneration showed the most severe degenerative change in the central auditory system.     

Cell cycle regulation of the Saccharomyces cerevisiae polo-like kinase cdc5p

Progression through and completion of mitosis require the actions of the evolutionarily conserved Polo kinase. We have determined that the levels of Cdc5p, a Saccharomyces cerevisiae member of the Polo family of mitotic kinases, are cell cycle regulated. Cdc5p accumulates in the nuclei of G2/M-phase cells, and its levels decline dramatically as cells progress through anaphase and begin telophase. We report that Cdc5p levels are sensitive to mutations in key components of the anaphase-promoting complex (APC). We have determined that Cdc5p-associated kinase activity is restricted to G2/M and that this activity is posttranslationally regulated. These results further link the actions of the APC to the completion of mitosis and suggest possible roles for Cdc5p during progression through and completion of mitosis.     

Activated protein C resistance, thrombophilia, and inflammatory bowel disease

Thromboembolic events frequently complicate the clinical course of patients with inflammatory bowel disease (IBD). Hereditary thrombophilia may contribute to this tendency. Resistance to activated protein C is the most recently described thrombophilic state and may account for up to 40% of patients with thrombophilia. Thirty-seven patients with IBD were studied (mean age 44 years, range 18-82 years). Three patients had a history of thrombotic episodes. The 37 controls included 23 men and 17 women (mean age 48 years, range 16-89 years). Disease activity was assessed using the Harvey Bradshaw index for patients with Crohn's disease and the Truelove and Witts grading system for patients with ulcerative colitis. Levels of fibrinogen, antithrombin III (ATIII), protein C, protein S, activated protein C resistance (APCR), and the presence of a lupus anticoagulant (LA) were determined. Median ATIII levels in patients with IBD were significantly lower than controls (98% vs 106%, P = 0.007), while fibrinogen was elevated (4.2 vs 3.3 g/liter, P = 0.026) despite quiescent disease activity. LA was detected in 7/37 patients in the IBD group compared to 0/37 controls. (chi2 = 5.68, P = 0.017). No significant difference was observed in levels of inherited thrombophilic factors and in particular APCR between IBD patients and controls. In conclusion, the presence of inherited thrombophilic defects, in particular APCR, is uncommon in patients with IBD and does not merit routine screening.     

Biotransformation of 2,4,6-trinitrotoluene (TNT) by a Methanococcus sp. (strain B) isolated from a lake sediment

The newly developed antihypertensive drugs, the long-acting beta-blocker propranolol and the sustained release calcium antagonist verapamil, are compared in their antihypertensive, platelet function, rheological properties and metabolic effects. The trial was a double-blind, randomised, placebo-controlled cross-over study. Thirty patients with mild to moderate hypertension received propranolol (40-120 mg) or verapamil (80-200 mg) once daily in two separate ten week courses. After ten weeks treatment both drugs had significantly reduced both SBP and DBP. Beta-thromboglobulin (beta-TG) concentration, reflecting the status of platelet activation in vivo, was significantly decreased after propranolol (129.6 +/- 13.5 vs. 77.9 +/- 8.6 ng/ml) and verapamil (129.6 +/- 13.5 vs. 90.7 +/- 10.1 ng/ml) treatments while platelet aggregation induced by ADP, collagen, arachidonic acid or adrenaline and the production of thromboxane B2 (TXB2), 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) and platelet cyclic 3'-5' adenosine monophosphate (C-AMP) concentration were not affected. Significant alterations in rheological parameters such as plasma and whole blood viscosity, fibrinogen level and red cell deformability were not found. Higher cholesterol and low-density lipoprotein-cholesterol (LDL-C) levels were observed after propranolol treatment but not in verapamil treatment. Side-effects were mild, tolerated and no patient had to be withdrawn from the study. In conclusion, propranolol and verapamil are generally effective antihypertensive as well as rheologically safe drugs. Compared with the metabolic effect on serum lipid, verapamil may be a better choice. Both drugs possess the tendency to inhibit platelet properties which is desirable in hypertension treatment.     

Structural characterization of vulcanizates. Part VI. The 2-mercaptobenzothiazole-accelerated natural rubber–sulfur system

The crosslinking efficiency of sulfur in the vulcanization of natural rubber in the presence of 2-mercaptobenzothiazole, zinc oxide, and lauric acid has been determined as a function of cure time, cure temperature, and lauric acid concentration. With a low concentration of lauric acid structurally complex networks are formed, which contain 11–19 combined sulfur atoms per chemical crosslink present. The complexity increases with time of vulcanization. With a high lauric acid concentration much simpler networks are formed, which become progressively more simple as reaction proceeds (6 network-combined sulfur atoms per chemical crosslink, decreasing to 2.4 with time). Increasing the cure temperature from 100 to 140°C. reduces the efficiency of crosslinking in both cases. The changes in efficiency are attributed to the influences of the reaction variables (in particular, the concentration of rubber-soluble complexes of the zinc laurate with zinc benzothiazolyl mercaptide) on the structure and subsequent reactions of initially formed polysulfidic crosslinks.     

Discrimination or favoritism? Sex bias in book reviews.

Studied 180 reviews of books written by male, female, or male and female authors to investigate sex bias. Half the books had been reviewed by males, half by females. Each review was rated separately for positive and negative elements. For positive elements, there was a significant interaction between author's and reviewer's sex: same-sex books were more favorably evaluated than other-sex books, while books of mixed authorship fell in between. There was no comparable interaction for negative elements. Reviewers of both sexes tended to find more negative elements in books by male than by female authors. It is concluded that unlike in studies employing hypothetical situations, in real-life settings each sex is biased in favor of itself. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An iterative technique for fitting exponentials

An interative method to fit the function \documentclass{article}\pagestyle{empty}\begin{document}$\mathop \[y = \sum\nolimits_i^n { = 1} a_i e^{lix}\] $\end{document} to data is considered. The technique used is that of inversion of a linear differential operator with constant coefficients. This method reproduces the parameters for mathematically precise data and gives satisfactory results when the data are affected by random errors.     

Perforating pseudoxanthoma elasticum. Its distinction from elastosis perforans serpiginosa

It is not generally appreciated that pseudoxanthoma elasticum (PXE) can be associated with epidermal perforation by elastic fibers. We report an example of this phenomenon. The term "perforating PXE" is suggested and a distinction is made from elastosis perforans serpiginosa (EPS). We believe that most reported cases of coexistence of PXE and EPS are perforating PXE and that the coexistence of EPS has not been clearly demonstrated.