A dual mechanism mediates repression of NF-kappaB activity by glucocorticoids

The mutants of Saccharomyces cerevisiae assigned to complementation group G199 are deficient in mitochondrial respiration and lack a functional cytochrome oxidase complex. Recombinant plasmids capable of restoring respiration were cloned by transformation of mutants of this group with a yeast genomic library. Sequencing indicated that a 2.1-kb subclone encompasses the very end (last 11 amino acids) of the PET111 gene, the COX7 gene and a new gene (YMR255W) of unknown function that potentially codes for a polypeptide of 188 amino acids (about 21.5 kDa) without significant homology to any known protein. We have shown that the respiratory defect corresponding to group G199 is complemented by plasmids carrying only the COX7 gene. The gene YMR255W was inactivated by one-step gene replacement and the disrupted strain was viable and unaffected in its ability to grow in a variety of different test media such as minimal or complete media using eight distinct carbon sources at three pH values and temperatures. Inactivation of this gene also did not affect mating or sporulation.     

Inter-individual variability in Ca2+ signalling in platelets from healthy volunteers: effects of aspirin and relationship with expression of endomembrane Ca2+-ATPases

Increased Ca2+ signal generation may lead to hyperactivity of platelets and contribute to thrombotic complications. Using fura-2-loaded platelets from 51 healthy volunteers, high variability was detected in the Ca2+ responses evoked by the receptor agonists, thrombin and collagen, and the inhibitor of sarco/endoplasmic reticulum Ca2+-ATPases (SERCA), thapsigargin (Tg). Oral intake of 500mg aspirin reduced the magnitude of the Ca2+ responses, and lowered the intra-individual coefficients of variance of the responses by 50%. However, the corresponding inter-individual variance coefficients were only a little influenced by aspirin intake, pointing to subject-dependent factors in Ca2+ handling that are unrelated to thromboxane formation. With each agonist, 6-9% of the subjects had platelets with relatively high Ca2+ responses (> mean + SD) both before and after aspirin intake. In 90% (9/10) of these cases the high responsiveness was confirmed in platelets obtained 6-12 months later. The Tg- but not thrombin-induced Ca2+ responses correlated inversely with the expression levels of SERCA PL/IM 430 (SERCA-3b) in platelets. After aspirin intake, the Ca2+ responses with collagen but not thrombin correlated inversely with SERCA-2b expression. These results suggest that, in the absence of potentiating effects of thromboxane, (i) the amount of PL/IM 430-recognizable SERCA may control the Ca2+ signal when SERCA-2b is specifically inhibited (with Tg), and (ii) the expression of SERCA-2b determine the collagen- but not the thrombin-evoked Ca2+ signal. Accordingly, limited Ca2+-pumping activity by low expression of one of the SERCA isoforms is likely to be one of the factors resulting in increased platelet activity towards collagen or thapsigargin but not thrombin.     

Prospective randomized study of early versus delayed laparoscopic cholecystectomy for acute cholecystitis

We asked whether the likelihood for mice of the C57BL/6J strain to develop glucose intolerance when fed a high-fat diet is related to the increase in circulating levels of leptin or free fatty acids (FFA). We therefore administered a high-fat diet (58% fat) or a control diet (11% fat) for 1.5 years. NMRI mice were used as a more glucose-tolerant control group. After a high-fat diet, the area under the glucose curve following an intraperitoneal glucose challenge (1 g/kg) increased more markedly in C57BL/6J mice (by 42+/-8%) than in NMRI mice (by 21+/-3%, P = 0.007). Plasma levels of insulin, leptin and FFA increased in both strains of mice, whereas plasma glucose levels were elevated after the high-fat diet only in C57BL/6J mice. The slope of the relationship between body weight and plasma leptin was higher in C57BL/6J mice than in NMRI mice. suggesting leptin insensitivity. Circulating leptin correlated to circulating insulin in both strains of mice, whereas plasma FFA correlated to plasma insulin in NMRI mice but not in C57BL/6J mice. These correlations remained significant after adjustment for body weight. The results show that elevated leptin and FFA levels evolve after high-fat feeding in mice, in conjunction with evolvement of glucose intolerance and hyperglycemia.     

Prediction of drinking outcomes for male alcoholics after 10 to 14 years

This study reports on the long-term outcomes of 360 men who were hospitalized for alcoholism during 1980 to 1984 and followed at 12 months and again 10 to 14 years later. At the 10/14-year follow-up, 96 (26.7%) men were confirmed as deceased; 255 (70.8%) men participated in the assessment/interview battery completed during baseline hospitalization. The battery consisted of psychosocial, alcohol-related, and psychiatric measures. Two distinct but highly correlated outcome measures were selected: a clinical rating scale and a factor score. Overall, predictors from baseline and 12-month follow-up included age at intake hospitalization, alcoholism severity, social stability, drinking days, and antisocial personality disorder. Approximately 37% of the assessed survivors were either totally abstinent or drinking nonabusively throughout the 10/14-year follow-up, whereas another 37% continued to drink abusively. Men who abstained or reduced alcohol intake reported better physical health at follow-up than those who continued to drink. Although our findings did not directly link alcoholism to death, they strongly indicate that chronic alcohol abuse may lead to premature death.     

Bupropion and desipramine increase dopamine transporter mRNA expression in the ventral tegmental area/substantia nigra of rat brain

The homeobox gene Otx2 is a mouse cognate of the Drosophila orthodenticle gene, which is required for development of the brain, rostral to rhombomere three. We have investigated the mechanisms involved in this neural function and specifically the requirement for Otx2 in the visceral endoderm and the neuroectoderm using chimeric analysis in mice and explant recombination assay. Analyses of chimeric embryos composed of more than 90% of Otx2-/- ES cells identified an essential function for Otx2 in the visceral endoderm for induction of the forebrain and midbrain. The chimeric studies also demonstrated that an anterior neural plate can form without expressing Otx2. However, in the absence of Otx2, expression of important regulatory genes, such as Hesx1/Rpx, Six3, Pax2, Wnt1 and En, fail to be initiated or maintained in the neural plate. Using explant-recombination assay, we could further demonstrate that Otx2 is required in the neuroectodem for expression of En. Altogether, these results demonstrate that Otx2 is first required in the visceral endoderm for the induction, and subsequently in the neuroectoderm for the specification of forebrain and midbrain territories.     

Congenital fibrosis of the extraocular muscles type 2, an inherited exotropic strabismus fixus, maps to distal 11q13

The extraocular fibrosis syndromes are congenital ocular-motility disorders that arise from dysfunction of the oculomotor, trochlear, and abducens nerves and/or the muscles that they innervate. Each is marked by a specific form of restrictive paralytic ophthalmoplegia with or without ptosis. Individuals with the classic form of congenital fibrosis of the extraocular muscles (CFEOM1) are born with bilateral ptosis and a restrictive infraductive external ophthalmoplegia. We previously demonstrated that CFEOM1 is caused by an autosomal dominant locus on chromosome 12 and results from a developmental absence of the superior division of the oculomotor nerve. We now have mapped a variant of CFEOM, exotropic strabismus fixus ("CFEOM2"). Affected individuals are born with bilateral ptosis and restrictive ophthalmoplegia with the globes "frozen" in extreme abduction. This autosomal recessive disorder is present in members of three consanguineous Saudi Arabian families. Genetic analysis of 70 individuals (20 affected individuals) reveals linkage to markers on chromosome 11q13, with a combined LOD score of 12.3 at the single nonrecombinant marker, D11S1314. The 2.5-cM CFEOM2 critical region is flanked by D11S4196/D11S4162 and D11S4184/1369. Two of the three families share a common disease-associated haplotype, suggesting a founder effect for CFEOM2. We hypothesize that CFEOM2 results from an analogous developmental defect to CFEOM1, one that affects both the superior and inferior divisions of the oculomotor nerve and their corresponding alpha motoneurons and extraocular muscles.     

Recombinant rat surfactant-associated protein D inhibits human T lymphocyte proliferation and IL-2 production

Components of the airspace-lining material may contribute to the local regulation of immune function within the lung. We report here that recombinant rat pulmonary surfactant-associated protein D (SP-D) inhibits the lectin- and anti-CD3-stimulated proliferation of human PBMCs. Inhibition was associated with a decreased production of IL-2, and the addition of human rIL-2 blocked the inhibitory action of SP-D. These effects were not inhibited by maltose, indicating that the inhibitory activity was not dependent upon the lectin activity of SP-D. Studies employing mutant SP-D lacking N-linked sugars or defective in multimerization further indicated that inhibition was not dependent upon cellular interactions with the N-linked oligosaccharide on SP-D or the oligomerization of trimeric SP-D subunits. Although a peptide containing an inverted DGR showed similar IL-2-dependent effects on anti-CD3-stimulated proliferation, deletion of the conserved DGRDGR sequence near the amino-terminal end of the collagen domain did not decrease the suppressive activity of SP-D. We hypothesize that SP-D can dampen lymphocyte responses to exogenous stimuli and protect the lung against collateral immune-mediated damage.     

Phyto-oestrogen excretion and rate of bone loss in postmenopausal women

OBJECTIVE: The hypothesis was tested that the rate of postmenopausal bone loss is inversely associated with long-term urinary excretion of phyto-oestrogens, as a marker of habitual dietary intake. DESIGN: Secondary analysis of a 10-year follow-up study (1979 1989) among postmenopausal women in the Netherlands. SUBJECTS: From the original population of 154 women, 32 women were selected with an annual rate of radial bone loss of < or = 0.5% over the first 5 years of the study and 35 women with a rate of > or = 2.5% per year. METHODS: The isoflavonoids genistein, daidzein and equol, and the lignan enterolactone were determined by gas chromatography mass spectrometry in aggregate samples from annually collected urine samples. Cortical bone density of the radius had previously been measured annually by single-photon absorptiometry. RESULTS: Excretion of isoflavonoids did not differ between both groups, although in multivariate analysis equol excretion was weakly positively associated with rate of bone loss in the 5 years after the menopause. Enterolactone excretion was significantly higher in the group with high rate of bone loss. This positive association remained in multivariate linear regression analysis after adjustment for age, years since menopause, body mass index and intake of calcium, vegetable protein and dietary fibre. CONCLUSIONS: Enterolactone excretion is likely to be an indicator of consumption of grains and legumes; it is not clear whether the observed positive association with rate of bone loss is a causal one. Our results do not support a preventive effect of low, unsupplemented dietary intake of phyto-oestrogens on postmenopausal cortical bone loss. However, no conclusions can be drawn about effects of higher doses of phyto-oestrogens.     

Efficacy and acceptability of two monophasic oral contraceptives containing ethinylestradiol and either desogestrel or gestodene

In this study, we have examined the effects of authentic nitric oxide (NO), NO+ (NOBF4), glutathione (GSH), glutathione disulphide (GSSG), and S-nitrosoglutathione (GSNO) in the presence and absence of Cu2+, which thermally releases NO from S-nitrosothiols on the transport of L-arginine into the human platelet. The K(M,apparent) was unaffected by NO, NO+, GSH, and GSNO. However, Cu2+ lowered K(M,apparent) by approximately 2.85-fold. Cu2+-dependent lowering of K(M,apparent) was also observed, albeit to a smaller extent when this ion was mixed with GSH (approximately 1.9-fold lower) and GSNO (approximately 2.0-fold). GSSG also lowered K(M,apparent) by approximately 1.5-fold. The Vmax,apparent of L-arginine uptake was unaffected by NO, NO+, GSH, and Cu2+. Vmax,apparent was stimulated by to the largest extent by GSNO (approximately 2.28-fold) and GSNO plus Cu2+ (approximately 2.7-fold). GSSG and GSH plus Cu2+ also increased Vmax,apparent by approximately 1.9-fold. When these parameters are expressed in terms of transport efficiency (Vmax/K(M)) the largest effect of nearly 4.7-fold (over controls) was obtained by a combination of GSNO plus Cu2+. These results suggest that platelet L-Arg transport is not affected either by NO or NO+ but by a thiol-disulphide exchange reactions on the platelet L-Arg transporter, brought about by GSNO and GSSG. Based on these results, a GSNO/GSSG/Cu2+ dependent regulatory mechanism for the uptake of L-arginine in human platelets has been proposed.