Efficacy of latex avoidance for primary prevention of latex sensitization in children with spina bifida

Over 6 years, the prevalence of latex sensitization fell from 4/15 (26.7%) to 1/22 (4.5%) in children with spina bifida treated in a latex-free environment from birth compared with historic controls. These precautions appear to be efficacious for the primary prevention of latex sensitization.     

Lack of association between -384 and 114 IL-2 gene polymorphisms and rheumatoid arthritis

OBJECTIVE: To investigate the association of 2 single nucleotide polymorphisms (SNP) at positions -384 and 114 in the human interleukin 2 (IL-2) gene with susceptibility to and severity of rheumatoid arthritis (RA). METHODS: Genotyping for these IL-2 variants was performed by a polymerase chain reaction restriction fragment length polymorphism method in 174 RA patients and 153 control individuals. RESULTS: No statistically significant differences were observed when the -384 and 114 IL-2 genotype distributions between RA patients and healthy controls were compared. In addition, no association was found between the IL-2 genotypes with any demographic and clinical variables tested. CONCLUSION: Our results provide no evidence for genetic association conferred by the -384 and 114 IL-2 SNP with respect to susceptibility and severity of RA.     

Natural genomic design in Sinorhizobium meliloti: novel genomic architectures

The complete nucleotide sequence of the genome of Sinorhizobium meliloti, the symbiont of alfalfa, was reported in 2001 by an international consortium of laboratories. The genome comprises a chromosome of 3.65 megabases (Mb) and two megaplasmids, pSymA and pSymB, of 1.35 Mb and 1.68 Mb, respectively. Based on the nucleotide sequence of the whole genome, we designed a pathway of consecutive rearrangements leading to novel genomic architectures. In a first step we obtained derivative strains containing two replicons; in a second step we obtained a strain containing the genetic information in one single replicon of 6.68 MB. From this last architecture we isolated revertants containing two replicons, and from these we could return to the original architecture showing the three replicons. We found that the relative frequency of excision of cointegrated replicons is higher at the site used for the cointegration than at other sites. This might conciliate two apparently opposed facts: the highly dynamic state of genomic architecture in S. meliloti and the common observation that different isolates and derived cellular clones of S. meliloti usually present the architecture of one chromosome and two distinct megaplasmids. Different aspects that must be considered to obtain full advantage of the strategy of natural genomic design are discussed.     

Exacerbation of psychosis by misinterpretation of physical symptoms

Impaired processing of perceptual information is often a prominent aspect of psychotic disorders. Physical symptoms such as pain or discomfort may be either incorrectly perceived or misinterpreted by psychotic patients. Presented here is a series of cases in which somatic symptoms occurred in psychotic patients and worsened their psychotic states but only later were recognized as physical problems. Psychotic patients may be unable to comprehend or describe their physical symptoms adequately. Physical disorders of psychotic patients may be overlooked if clinicians are not vigilant and thorough in assessing the patients' complaints, especially if such complaints sound delusional or bizarre.     

Venous response to nitroglycerin is enhanced in young, healthy carriers of the 825T allele of the G protein beta3 subunit gene (GNB3)

OBJECTIVE: The ultimate mode of action by which nitroglycerin elicits vasodilation remains elusive. Animal studies point to an involvement of pertussis toxin-sensitive G proteins. The 825T allele of the GNB3 C825T polymorphism in the gene encoding the G protein beta3 subunit is associated with enhanced signal transduction via pertussis toxin-sensitive pathways in vitro. We hypothesized that G proteins have a role in nitroglycerin-mediated vasodilation and that carriers of the 825T allele would exhibit a stronger response to nitroglycerin. METHODS: We used the linear variable transducer technique to compare dorsal hand vein compliance in 28 young, healthy men with and without the T allele (n = 15 CC, n = 8 CT, and n = 5 TT). After individual dose-response curves to phenylephrine had been established, veins were preconstricted to 70% of the maximal phenylephrine-induced constriction. Nitroglycerin was then infused in ascending doses (0.02-2000 ng/min), and the vasodilatory response was measured. RESULTS: The vasodilatory response to nitroglycerin was significantly greater in carriers of the 825T allele. The maximal response to nitroglycerin was 102% +/- 6% venodilation in the CT/TT group and 78% +/- 5% in the CC control group (P =.0045) (mean difference, -24% +/- 8%; 95% confidence interval, 8%-40%). Comparison of the nitroglycerin dose-response curves by ANOVA confirmed an enhanced nitroglycerin-induced venodilation in 825T-allele carriers (P <.0001). CONCLUSION: Our results suggest that the GNB3 C825T polymorphism determines venous response to nitroglycerin and that G proteins may be involved in the signal transduction pathway.     

Effects of hypocaloric diet on sleep in young and old rats

Aging produces a loss in a number of behavioral and cognitive functions, including sleep. Hypocaloric diet is one of the few methods that have been shown to retard the effects due to age. However, the effects of such a diet on sleep have never been investigated. In the present study, 21 months old male F344 rats fed a 60% calorie-reduced diet continued to have a significant reduction in delta power (0.3-4 Hz EEG), less sleep following 12 h total sleep deprivation (TSD) and increased sensitivity to caffeine compared to young rats (3 months) fed a similar diet. These results indicate that caloric restriction is unable to prevent the decline in sleep that occurs with aging.     

Supersensitivity of the cholinergic muscarinic system in the rat's brain is induced by high concentrations of Cu+2

Transition metals have been described as regulators of receptor's function. here, we studied the effects of chronic administration of Cu2+ or the Cu2+ chelator penicillamine (PA) on the functional and binding properties of the muscarinic receptors (MR) on selected areas of rat's brain. Groups of 10 Sprague-Dawley rats were treated daily, for 45 days with either 1) 1 mg/Kg CuSO4 (Cu2+), 2) 100 mg/Kg PA, or 3) saline solution. Double T-maze and motility cages were used for behavioral testing and the binding assays were performed using [3H]-QNB or [3H]-N-MSCP as MR's ligands. Cu2+ brain levels were measured in the cerebral cortex by atomic absorption spectrophotometer. Results showed that PA treated rats displayed a significant decrease of locomotor's activity (LA) and rearing behavior (RB), but a significant increases in memory efficiency (ME). Cu2+ treated rats displayed diminished RB with no significant changes in LA. Cu2+ treated rats displayed higher MR's density (Bmax) in cortex (C), striatum (S), and hippocampus (H). An increase in Bmax was also observed in PA treated rats, but only in C and S. Finally, Cu2+ tissue concentration was significantly higher in C of both Cu2+ and with PA treated animals. In conclusion, 45 days of Cu2+ or PA treatment induced brain hypercuprosis, which was associated with MR binding supersensitivity; however, change in ME was only observed in PA treated rats suggesting that might be still another factor in these experiments besides Cu2+ (i.e., Zn2+ or PA itself) involved in memory modulation.