Linkage relationships of the protein kinase C gamma gene which exclude it as a candidate for myotonic dystrophy

Using a cDNA probe for the gamma gene of protein kinase C (PKCG), an informative RFLP with a PIC value of 0.62 has been identified with the enzyme MspI. The polymorphic bands have been assigned to chromosome 19. Analysis of the segregation of alleles for this probe in myotonic dystrophy families show several recombinants between PKCG and myotonic dystrophy (DM) and exclude this gene as a candidate for DM. Linkage relationships between PKCG and other loci on chromosome 19 are presented which exclude PKCG from the proximal region of chromosome 19 and which are consistent with the localization being at 19q13.2----qter.     

Insulin stimulates the tyrosyl phosphorylation and activation of the 52 kDa peripheral plasma-membrane cyclic AMP phosphodiesterase in intact hepatocytes.

The 52 kDa subunit of the peripheral-plasma-membrane insulin-stimulated high-affinity cyclic AMP phosphodiesterase can be specifically detected by the antibody PM1 by Western-blotting procedures and also can be immunoprecipitated from a hepatocyte extract. PM1-mediated immunoprecipitation from hepatocyte extracts showed that insulin treatment of intact 32P-labelled hepatocytes caused the rapid phosphorylation of the peripheral-plasma-membrane cyclic AMP phosphodiesterase. Phosphoamino acid analysis and the use of a phosphotyrosine-specific antibody indicated that phosphorylation occurred on tyrosyl residue(s) of this phosphodiesterase. Prior treatment of hepatocytes with glucagon (10 nM) completely blocked the insulin-mediated tyrosyl phosphorylation of this 52 kDa protein, as detected with both the PM1 and the anti-phosphotyrosine antibodies. Treatment of hepatocytes with glucagon alone did not increase the phosphorylation state of the peripheral-plasma-membrane cyclic AMP phosphodiesterase. The specific anti-phosphotyrosine antibody also detected the insulin-stimulated phosphorylation of proteins of 180 kDa, 95 kDa and 39 kDa. Prior treatment of hepatocytes with glucagon decreased the ability of insulin to phosphorylate the 180 kDa and 39 kDa species, but not the 95 kDa species.     

A nonparametric method for fitting a single exponential to biological data.

A nonparametric (“median”) method for fitting a single exponential to biological data is described. Its performance compared with that of least-squares alternatives has been assessed by analyzing simulated experimental data. The method appears to be reliable and relatively efficient.     

Thermal analysis and devolatilization kinetics of cotton stalk, sugar cane bagasse and shea meal under nitrogen and air atmospheres

Thermal degradation, reactivity and kinetics for biomass materials cotton stalk (CS), sugarcane bagasse 1 (SB1), sugarcane bagasse 2 (SB2) and shea meal (SM) have been evaluated under pyrolysis (N(2)) and oxidising (dry air) conditions, using a non-isothermal thermogravimetric method (TGA). In the cases of CS and SB1 the peak temperatures were 51 degrees C higher for pyrolysis compared with oxidative degradation, whereas for SB2 and SM the difference was approximately 38 degrees C. However, the differences in the rates of weight loss were significantly higher under oxidising conditions for all the materials studied. Maximum rate of weight loss (%s(-1)) under pyrolysis conditions ranged from 0.10 to 0.18 whereas these values accelerated to the range of 0.19-0.28 under oxidising conditions, corresponding to respective peak temperatures. Samples ranked in order of reactivity (R(M)x10(3)) (%s(-1) degrees C(-1)) are CS=1.31 approximately SM=1.30>SB2=1.14>SB1=0.94 for air and CS=0.54>SB2=0.49>SB1=0.45>SM=0.31 for nitrogen. Shea meal exhibited a complex char combustion behaviour indicating that there may be two distinct types of char derived from fibrous and woody components in the original material. Activation energy calculations were based on the Arrhenius correlation.     

Genetic Variation in the Familial Mediterranean Fever Gene (MEFV) and Risk for Crohn's Disease and Ulcerative Colitis

Background and Aims

The familial Mediterranean fever (FMF) gene (MEFV) encodes pyrin, a major regulator of the inflammasome platform controlling caspase-1 activation and IL-1β processing. Pyrin has been shown to interact with the gene product of NLRP3, NALP3/cryopyrin, also an important active member of the inflammasome. The NLRP3 region was recently reported to be associated with Crohn''s disease (CD) susceptibility. We therefore sought to evaluate MEFV as an inflammatory bowel disease (IBD) susceptibility gene.

Methodology and Results

MEFV colonic mucosal gene expression was significantly increased in experimental colitis mice models (TNBS p<0.0003; DSS p<0.006), in biopsies from CD (p<0.02) and severe ulcerative colitis (UC) patients (p<0.008). Comprehensive genetic screening of the MEFV region in the Belgian exploratory sample set (440 CD trios, 137 UC trios, 239 CD cases, 96 UC cases, and 107 healthy controls) identified SNPs located in the MEFV 5′ haplotype block that were significantly associated with UC (rs224217; p = 0.003; A allele frequency: 56% cases, 45% controls), while no CD associations were observed. Sequencing and subsequent genotyping of variants located in this associated haplotype block identified three synonymous variants (D102D/rs224225, G138G/rs224224, A165A/rs224223) and one non-synonymous variant (R202Q/rs224222) located in MEFV exon 2 that were significantly associated with UC (rs224222: p = 0.0005; A allele frequency: 32% in cases, 23% in controls). No consistent associations were observed in additional Canadian (256 CD trios, 91 UC trios) and Scottish (495 UC, 370 controls) sample sets. We note that rs224222 showed marginal association (p = 0.012; G allele frequency: 82% in cases, 70% in controls) in the Canadian sample, but with a different risk allele. None of the NLRP3 common variants were associated with UC in the Belgian-Canadian UC samples and no significant interactions were observed between NLRP3 and MEFV that could explain the observed flip-flop of the rs224222 risk allele.

Conclusion

The differences in association levels observed between the sample sets may be a consequence of distinct founder effects or of the relative small sample size of the cohorts evaluated in this study. However, the results suggest that common variants in the MEFV region do not contribute to CD and UC susceptibility.