Association of MSX1 and TGFB3 with nonsyndromic clefting in humans.

Nonsyndromic cleft lip with or without cleft palate (CL/P) and nonsyndromic cleft palate only (CPO) are common congenital anomalies with significant medical, psychological, social, and economic ramifications. Both CL/P and CPO are examples of complex genetic traits. There exists sufficient evidence to hypothesize that disease loci for CL/P and CPO can be identified by a candidate-gene linkage-disequilibrium (LD) strategy. Candidate genes for clefting, including TGFA, BCL3, DLX2, MSX1, and TGFB3, were screened for LD with either CL/P or CPO in a predominantly Caucasian population, with both case-control- and nuclear-family-based approaches. Previously reported LD for TGFA with both CL/P and CPO could not be confirmed, except in CL/P patients with a positive family history. Also, in contrast to previous studies, no LD was found between BCL3 and either CL/P or CPO. Significant LD was found between CL/P and both MSX1 and TGFB3 and between CPO and MSX1, suggesting that these genes are involved in the pathogenesis of clefting. In addition, a mutation search in the genes DLX2, MSX1, and TGFB3 was performed in 69 CPO patients and in a subset of the CL/P patients. No common mutations were found in the coding regions of these genes; however, several rare variants of MSX1 and TGFB3 were found that may alter the latters' normal function. These results form the basis for future research, including (a) mutation searches in the MSX1 and TGFB3 genes in Caucasian CL/P patients and (b) extension of the search for MSX1 mutations in CPO patients to the noncoding regions.     

beta blockade and intermittent claudication: placebo controlled trial of atenolol and nifedipine and their combination.

OBJECTIVE--To determine the effects of the beta 1 selective adrenoceptor blocker atenolol, the dihydropyridine calcium antagonist nifedipine, and the combination of atenolol plus nifedipine on objective and subjective measures of walking performance and foot temperature in patients with intermittent claudication. DESIGN--Randomised controlled double blind four way crossover trial. SETTING--Royal Hallamshire Hospital, Sheffield. SUBJECTS--49 patients (40 men) aged 39-70 with chronic stable intermittent claudication. INTERVENTIONS--Atenolol 50 mg twice daily; slow release nifedipine 20 mg twice daily; atenolol 50 mg plus slow release nifedipine 20 mg twice daily; placebo. Each treatment was given for four weeks with no washout interval between treatments. MAIN OUTCOME MEASURES--Claudication and walking distances on treadmill; skin temperature of feet as measured by thermistor and probe; blood pressure before and after exercise; subjective assessments of walking difficulty and foot coldness with visual analogue scales. RESULTS--Atenolol did not significantly alter claudication distance (mean change -6%; 95% confidence interval 1% to -13%), walking distance (-2%; 4% to -8%), or foot temperature. Nifedipine did not alter claudication distance (-4%; 3% to -11%), walking distance (-4%; 3% to -10%), or foot temperature. Atenolol plus nifedipine did not alter claudication distance but significantly reduced walking distance (-9%; -3% to -15% (p less than 0.003)) and skin temperature of the more affected foot (-1.1 degrees C; 0 to -2.2 degrees C (p = 0.05)). These effects on walking distance and foot temperature seemed unrelated to blood pressure changes. CONCLUSIONS--There was no evidence of adverse or beneficial effects of atenolol or nifedipine, when given singly, on peripheral vascular disease. The combined treatment, however, affected walking ability and foot temperature adversely. This may have been due to beta blockade plus reduced vascular resistance, which might also explain the reported adverse effects of pindolol and labetalol on claudication.     

Establishing a food-chain link between aquatic plant material and avian vacuolar myelinopathy in mallards (Anas platyrhynchos)

Avian vacuolar myelinopathy (AVM) is a neurologic disease primarily affecting bald eagles (Haliaeetus leucocephalus) and American coots (Fulica americana). The disease was first characterized in bald eagles in Arkansas in 1994 and then in American coots in 1996. To date, AVM has been confirmed in six additional avian species. Attempts to identify the etiology of AVM have been unsuccessful to date. The objective of this study was to evaluate dermal and oral routes of exposure of birds to hydrilla (Hydrilla verticillata) and associated materials to evaluate their ability to induce AVM. Mallards (Anas platyrhynchos) were used in all trials; bobwhite quail (Colinus virginianus) also were used in one fresh hydrilla material exposure trial. Five trials were conducted, including two fresh hydrilla material exposure trials, two cyanobacteria exposure trials, and a frozen hydrilla material exposure trial. The cyanobacteria exposure trials and frozen hydrilla material trial involved gavaging mallards with either Pseudanabaena catenata (live culture), Hapalosiphon fontinalis, or frozen hydrilla material with both cyanobacteria species present. With the exception of one fresh hydrilla exposure trial, results were negative or inconclusive. In the 2002 hydrilla material exposure trial, six of nine treated ducks had histologic lesions of AVM. This established the first cause-effect link between aquatic vegetation and AVM and provided evidence supporting an aquatic source for the causal agent.     

Populations Microbiennes Des Bois

Resumé Les auteurs ont étudié la composition chimique (N, substances humiques, lignine) de copeaux de bois blanc exposés à l'air libre depuis 2 à 10 ans, ainsi que leur type de peuplement fongique. En l'absence de lignivore, le pH, les taux de lignine et d'N s'élèvent et il se forme des quantités modérées d'humus à forte capacité d'échange. Dans le cas contraire, on voit apparaître, en abondance, des substances humiques peu condensées et la matière organique subit une évolution rappelant celle du mor.Avec la collaboration technique de Melle. M. Clet.Kononova, dans sa monographie⁵, signale de Troussov (1916) une étude que nous n'avons pas eu en mains.     

Studies of esterase 6 in Drosophila melanogaster. XVIII. Biochemical differences between the slow and fast allozymes

Most natural populations of Drosophila melanogaster are polymorphic for two major electrophoretic variants at the esterase-6 locus. The frequency of the EST 6F allozyme is greatest in populations in warmer latitudes, whereas the EST 6S allozyme is predominant in colder latitudes. Latitudinal clines in electromorph frequencies are found on three continents. Purified preparations of the allozymes have been characterized for their pH optimum, substrate specificity, organophosphate inhibition, alcohol activation, thermal stability, and kinetic parameters. These and previous analyses of the EST 6 allozymes reveal that the two variants have differences in their physical and kinetic properties that may provide a basis for the selective maintenance of the polymorphisms and an explanation of the clinal variation observed in natural populations.      

Changes in non-randomness in the expanding introduced avifauna of the world

The identities of bird species introduced to areas beyond the limits of their native geographic ranges have historically depended on a combination of societal demands for species with certain characteristics, and the availability of species for capture, transport and release. However, both societal demands and availability have changed over time, which should also change the characteristics of species more recently added to the list of introduced birds. Here, we quantify temporal changes in selectivity of introduced bird species by comparing the characteristics of 423 species listed in the seminal catalogue of introduced birds (Long, J. L. 1981 . Introduced birds of the world. – David and Charles, London) with those of 122 species that have been introduced but are not listed in Long (1981) . We demonstrate differences between these two groups of species in the frequencies with which different taxa are represented, in the geographic range sizes of species, and in their biogeographic regions of origin, but not in body mass. Both groups also differ from bird species in general in terms of geographic range sizes, body masses, and taxonomic composition. We relate the observed differences in the characteristics of species listed or unlisted in Long (1981) to changes in the changes in attitudes, legislation and vectors of transport relating to exotic species. We conclude by noting that the utility of published catalogues of introduced bird species is increasingly being eroded by the continued liberation and establishment of bird species.