Genome Sequence of Campylobacter jejuni strain 327, a strain isolated from a turkey slaughterhouse

Campylobacter is one of the leading causes of food-borne gastroenteritis and has a high prevalence in poultry. Campylobacter jejuni subsp. jejuni 327 is a subspecies of the genus Campylobacter of the family Campylobacteraceae in the phylum Proteobacteria. The microaerophilic, spiral shaped, catalase positive bacterium obtains energy from the metabolism of amino acids and Krebs cycle intermediates. Strain 327 was isolated from a turkey slaughter production line and is considered environmentally sensitive to food processing (cold, heat, drying) and storage conditions. The 327 whole genome shotgun sequence of 1,618,613 bp long consists of 1,740 protein-coding genes, 46 tRNA genes and 3 rRNA operons. A protein based BLAST analysis places the turkey isolate 327 close to the human clinical strain 81116 (NCTC 11828).     

Melatonin Ameliorates Cerebral Vasospasm After Experimental Subarachnoidal Haemorrhage Correcting Imbalance of Nitric Oxide Levels in Rats

In the present study, we investigated the in vivo effects of melatonin on SAH-induced cerebral vasospasm and oxidative stress, resulting from SAH in an experimental rat model. Twenty-eight rats (225–250 g) were divided into four groups equally: group 1; control, group 2; SAH, group 3; SAH plus placebo, and group 4; SAH plus melatonin. We used double haemorrhage method for SAH groups. Beginning 6 h after SAH, 20 mg/kg melatonin or equal volume of 0.9% saline was administered intraperitoneally twice daily for 5 days to groups 3 and 4, respectively. Melatonin or 0.9% saline injections were continued up to fifth day after SAH and rats were sacrificed at the end of this period. Brain sections at the level of the pons were examined by light microscopy. The lumen diameter and the vessel wall thickness of basilar artery were measured using a micrometer. The serum levels of cerebral vasodilator nitric oxide (NO), the brain levels of an intrinsic antioxidant superoxide dismutase (SOD) and a NO regulator arginase activities were measured. The brain levels of inducible nitric oxide (iNOS) and nitrotyrosine, a nitrosative stress parameter immunohistochemiacally determined. In conclusion, melatonin administration ameliorated cerebral vasospasm by increasing serum NO level and decreasing the brain the levels of arginase and oxidative stress. It is therefore possible that increased brain arginase activity after SAH may also have a significant role in the pathogenesis of vasospasm by limiting the availability of arginine for NO production.     

Biocomposite films based on alginate and organically modified clay

Sodium alginate/sodium montmorillonite hybrid films were prepared by casting from the suspension of sodium alginate and different clay samples. Clay samples had been modified with a cationic surfactant, a cationic polymer, and a small polar molecule, respectively. Benzethonium chloride, polyethyleneimine and urea were used as clay modifiers. The composite films begin to disintegrate at a higher temperature and with less weight loss than the pure alginate films. This suggests an enhancement of the film thermal stability due to the modification of the alginate with clay samples.     

Heterochromatin and interstitial telomeric DNA homology

The purpose of this investigation was twofold. The first objective was to demonstrate that, in most of ten mammalian species commonly used in biomedical research, not all constitutive heterochromatin (C-bands) represents telomeric DNA. For example, the C-bands in human chromosomes, the long arm of the X and the entire Y chromosome of Chinese hamster, and most of the short arms of Peromyscus and Syrian hamster chromosomes are not telomeric DNA. In addition to the usual terminal telomeric DNA in the chromosomes of these mammalian species, the pericentromeric regions of seven or eight Syrian hamster chromosomes and all Chinese hamster chromosomes except pair one have pericentromeric regions that hybridize with telomeric DNA, some in C-bands and some not. The second objective was to describe a simple fluorescence in situ hybridization (FISH) reverse-printing procedure to produce black-and-white microphotographs of metaphase and interphase cells showing locations of telomeric DNA with no loss of resolution. Thus, at least three different types of heterochromatin (telomeric heterochromatin, nontelomeric heterochromatin and a combination of both) are present in these mammalian species, and this simple black-and-white reverse printing of telomeric FISH preparations can depict them economically without sacrificing clarity.     

Quantification of tumor cellularity and mitotic index in invasive ductal carcinoma of the breast

OBJECTIVE: To evaluate the use of stereologically estimated tumor cell counts in the mitotic index as well as to investigate its correlation with the currently used method and test the reproducibility of the method. STUDY DESIGN: The stereologic method described by Simpson et al was used to estimate tumor cellularity in 50 invasive ductal carcinomas. Mitotic counts were also performed, and the mitotic index was calculated by the use of estimated tumor cell counts. Estimated cell counts and the mitotic index calculated were compared statistically with the actual cell counts and the traditional mitotic grades, respectively. Interobserver reproducibility of the method was also tested. RESULTS: Stereologically estimated tumor cell counts had a good correlation with actual cell counts (r = .891, P < .001). Besides, the mitotic indices calculated with tumor cell counts (calculated with both estimated and actual cell counts) in the denominator of the fraction of the mitotic index were in agreement with the currently used method (P < .01 for both). There was no statistically significant difference between the counts of two observers (P = .068). CONCLUSION: The suggested method, considering tumor cellularity as an influencing factor, was practical, reproducible and in agreement with the traditional method. This method should be studied in a large group of patients with follow-up data to determine the threshold values for different grades and determine its prognostic value during the disease course.     

In vitro inhibition effects of some new sulfonamide inhibitors on human carbonic anhydrase I and II

A new series of aromatic and heterocyclic sulfonamides, including six new derivatives, 2-(3-cyclohexene-1-carbamido)-1,3,4-thiadiazole-5-sulfonamide (CCTS), 4-(3-cyclohexene-1-carbamido) methyl-benzenesulfonamide (CCBS), 2-(9-octadecenoylamido)-1,3,4-thiadiazole-5-sulfonamide (ODTS), 2-(4,7,10-trioxa-tetradecanoylamido)-1,3,4-thiadiazole-5-sulfonamide (TDTS), 2-(coumarine-3-carbamido)-1,3,4-thiadiazole-5-sulfonamide (COTS) and 2-(8-methoxycoumarine-3-carbamido)-1,3,4-thiadiazole-5-sulfonamide (MCTS), has been investigated. These sulfonamides were assayed for inhibition of human carbonic anhydrase I (hCA-I) and human carbonic anhydrase II (hCA-II) which were purified by affinity chromatography.     

Carbonic anhydrase inhibitors: inhibition of the human transmembrane isozyme XIV with a library of aromatic/heterocyclic sulfonamides

The first inhibition study of the transmembrane carbonic anhydrase (CA, EC 4.2.1.1) isozymes hCA XIV with a library of aromatic and heteroaromatic sulfonamides synthesized earlier is reported. Most of the inhibitors were sulfanilamide, homosulfanilamide and 4-aminoethyl-benzenesulfonamide derivatives, to which tails that would induce diverse physicochemical properties have been attached at the amino moiety. Several of these compounds were metanilamide, benzene-1,3-disulfonamide or the 1,3,4-thiadiazole/thiadiazoline-2-sulfonamide derivatives. The tails incorporated in these molecules were of the alkyl/aryl-carboxamido/ sulfonamido-, ureido- or thioureido-types. The sulfanilamides acylated at the 4-amino group with short aliphatic/aromatic moieties incorporating 2-6 carbon atoms showed modest hCA XIV inhibitory activity (K(I)-s in the range of 1.25-4.2 microM) which were anyhow better than that of sulfanilamide (K(I) of 5.4 microM). Better activity showed the homosulfanilamide and 4-aminoethyl-benzenesulfonamide derivatives bearing arylsulfonamido/ureido and thioureido moieties, with K(I)'s in the range of 203-935 nM. The best activity was observed for the heteroaromatic compounds incorporating 1,3,4-thiadiazole/thiadiazoline-2-sulfonamide and 5-arylcarboxamido/sulfonamido moieties, with K(I)'s in the range of 10-85 nM. All these compounds were generally also much better inhibitors of the other two transmembrane CA isozyme, hCA IX and XII. Thus, highly potent hCA XIV inhibitors were detected, but isozyme-specific inhibitors were not discovered for the moment.     

Characterization and molecular genetic complementation of mutants affecting dimorphism in the fungus ustilago maydis

Ustilago maydis, the causal agent of corn smut disease, displays dimorphic growth in which it alternates between a unicellular, nonpathogenic yeast-like form and a dikaryotic, pathogenic filamentous form. Previously, a constitutively filamentous haploid mutant was obtained. Complementation of this mutant led to the isolation of the gene encoding adenylate cyclase, uac1. Secondary mutagenesis of a uac1 disruption strain allowed the isolation of a large number of suppressor mutants, termed ubc, for Ustilago bypass of cyclase, lacking the filamentous phenotype. Analysis of one of these suppressor mutants previously led to the identification of the ubc1 gene, encoding the regulatory subunit of cAMP-dependent protein kinase. In this report we describe the isolation of cosmids containing three new ubc genes, termed ubc2, ubc3, and ubc4. We also describe the morphology of the ubc2, ubc3, and ubc4 mutants in a uac1- background as well as in a background with a functional uac1 gene. In addition, we describe several mutant strains not complemented with any of the genes currently in hand and that are thus presumed to possess mutations in additional ubc genes. Copyright 1998 Academic Press.     

The taste of polycose in hamsters

Hamsters show a preference for Polycose, a mixture of starch-derived glucose polymers, that is as strong as their preference for sucrose. However, in the hamster, taste aversions to Polycose may be less easily acquired than taste aversions to sucrose and the qualitative aspects of Polycose are unknown in this species. In order to examine the taste of Polycose in the hamster, we utilized a taste-aversion protocol with two conditioning trials. Animals were trained to avoid one of three different conditioning stimuli: 50 mM sucrose, 100 mM Polycose and a mixture of 50 mM sucrose with 100 mM Polycose. Control animals were conditioned with deionized water. After the second conditioning trial, generalization testing began for the three conditioning stimuli plus 3 mM citric acid, 300 mM KCI and 30 mM NaCl. The results showed that aversions to Polycose, sucrose or the Polycose/sucrose mixture cross- generalized, demonstrating that Polycose and sucrose share a common taste percept in the hamster. None of the aversions generalized to NaCl, citric acid or KCI. In addition, comparisons among the patterns of taste generalizations indicated that the tastes of Polycose and sucrose also had distinct qualitative components. Finally, although the taste of 100 mM Polycose was more salient than the taste of 50 mM sucrose, the taste of sucrose could still be detected in a mixture with Polycose.