Germline mutations of the CDKN2 gene in UK melanoma families

Germline mutations in CDKN2 on chromosome 9p21, which codes for the cyclin D kinase inhibitor p16, and more rarely, mutations in the gene coding for CDK4, the protein to which p16 binds, underlie susceptibility in some melanoma families. We have sequenced all exons of CDKN2 and analysed the CDK4 gene for mutations in 27 UK families showing evidence of predisposition to melanoma. Five different germline mutations in CDKN2 were found in six families. Three of the mutations (Met53Ile, Arg24Pro and 23ins24) have been reported previously. We have identified two novel CDKN2 mutations (88delG and Ala118Thr) which are likely to be associated with the development of melanoma, because of their co-segregation with the disease and their likely functional effect on the CDKN2 protein. In binding assays the protein expressed from the previously described mutation, Met53Ile, did not bind to CDK4/CDK6, confirming its role as a causal mutation in the development of melanoma. Ala118Thr appeared to be functional in this assay. Arg24Pro appeared to bind to CDK6, but not to CDK4. No mutations were detected in exon 2 of CDK4, suggesting that causal mutations in this gene are uncommon. The penetrance of these mutant CDKN2 genes is not yet established, nor is the risk of non-melanoma cancer to gene carriers.      

Identification of MEN1 gene mutations in sporadic carcinoid tumors of the lung

Lung carcinoids occur sporadically and rarely in association with multiple endocrine neoplasia type 1 (MEN1). There are no well defined genetic abnormalities known to occur in these tumors. We studied 11 sporadic lung carcinoids for loss of heterozygosity (LOH) at the locus of the MEN1 gene on chromosome 11q13, and for mutations of the MEN1 gene using dideoxy fingerprinting. Additionally, a lung carcinoid from a MEN1 patient was studied. In four of 11 (36%) sporadic tumors, both copies of the MEN1 gene were inactivated. All four tumors showed the presence of a MEN1 gene mutation and loss of the other allele. Observed mutations included a 1 bp insertion, a 1 bp deletion, a 13 bp deletion and a single nucleotide substitution affecting a donor splice site. Each mutation predicts truncation or potentially complete loss of menin. The remaining seven tumors showed neither the presence of a MEN1 gene mutation nor 11q13 LOH. The tumor from the MEN1 patient showed LOH at chromosome 11q13 and a complex germline MEN1 gene mutation. The data implicate the MEN1 gene in the pathogenesis of sporadic lung carcinoids, representing the first defined genetic alteration in these tumors.      

Comparison between testosterone oenanthate-induced azoospermia and oligozoospermia in a male contraceptive study. IV. Suppression of endogenous testicular and adrenal androgens

Administration of supraphysiological doses of testosterone to normal men causes inhibition of spermatogenesis, but while most become azoospermic, 30-55% maintain a low rate of spermatogenesis. We have investigated whether there are differences in endogenous androgen production, of testicular and adrenal origin, which may be related to the degree of suppression of spermatogenesis. Thirty-three healthy Caucasian men were given weekly i.m. injections of 200 mg testosterone oenanthate (TE), 18 became azoospermic, while 15 remained oligozoospermic. Urinary excretion of epitestosterone, a specific testicular product, was reduced to <10% of pretreatment values, with no differences between the groups. Similar results were obtained for other markers of testicular steroidogenesis. Urinary and plasma adrenal androgens were also reduced during TE treatment: a statistically significant decrease in both (P < 0.001 and P < 0.05 respectively) was seen in the azoospermic but not oligozoospermic responders. These results suggest that testicular steroidogenesis is decreased to <10% by the administration of supraphysiological doses of exogenous testosterone. Differences in the degree of ongoing steroidogenesis in the testis do not appear to account for incomplete suppression of spermatogenesis, thus differences in androgen metabolism may underlie this heterogeneous response. A small but significant reduction in secretion of adrenal androgens was also detectable, the relevance of which is unclear.      

Activation of cannabinoid CB2 receptors suppresses C-fiber responses and windup in spinal wide dynamic range neurons in the absence and presence of inflammation

Effects of the CB2-selective cannabinoid agonist AM1241 on activity evoked in spinal wide dynamic range (WDR) neurons by transcutaneous electrical stimulation were evaluated in urethane-anesthetized rats. Recordings were obtained in both the absence and the presence of carrageenan inflammation. AM1241, administered intravenously or locally in the paw, suppressed activity evoked by transcutaneous electrical stimulation during the development of inflammation. Decreases in WDR responses resulted from a suppression of C-fiber-mediated activity and windup. Abeta- and Adelta-fiber-mediated responses were not reliably altered. The AM1241-induced suppression of electrically evoked responses was blocked by the CB2 antagonist SR144528 but not by the CB1 antagonist SR141716A. AM1241 (33 microg/kg intraplantar [i.p.l.]), administered to the carrageenan-injected paw, suppressed activity evoked in WDR neurons relative to groups receiving vehicle in the same paw or AM1241 in the opposite (noninflamed) paw. The electrophysiological effects of AM1241 (330 microg/kg intravenous [i.v.]) were greater in rats receiving i.p.l. carrageenan compared with noninflamed rats receiving an i.p.l. injection of vehicle. AM1241 failed to alter the activity of purely nonnociceptive neurons recorded in the lumbar dorsal horn. Additionally, AM1241 (330 microg/kg i.v. and i.p.l.; 33 microg/kg i.p.l.) reduced the diameter of the carrageenan-injected paw. The AM1241-induced decrease in peripheral edema was blocked by the CB2 but not by the CB1 antagonist. These data demonstrate that activation of cannabinoid CB2 receptors is sufficient to suppress neuronal activity at central levels of processing in the spinal dorsal horn. Our findings are consistent with the ability of AM1241 to normalize nociceptive thresholds and produce antinociception in inflammatory pain states.     

Nucleotide sequences of novel HLA-B35 subtypes

In recent reports we described novel hybridization patterns (HP) corresponding to 22 potentially new HLA-B locus alleles in a panel of 547 subjects studied by PCR-SSOP. Three of them correspond to new subtypes of B35. To confirm the hybridization results we have isolated DNA from PBL and performed PCR, DNA cloning and nucleotide sequencing. One of the alleles, locally called B-3505v was found in three individuals: two Hispanic, one Caucasoid. It differs from B^*3505 by 3 nucleotide substitutions that lead to changes in residues 94 (Ile > Thr), 95 (Ile > Leu) and 103 (Val > Leu). B-3505v differs from B^*3501 in residues 97 and 103. Another allele called B-3508v, was found in 7 individuals, (6 of 122 Toba Indians, 1 of 18 Pilaga Indians). It differs from B^*3509 in two silent nucleotide substitutions (codons 135 and 138) and in one substitution in residue 156 (Arg > Leu). The new allele has a hybrid sequence between B^* 3508 and B^*4801. A third subtype, locally called B-3504v, observed in two Hispanic individuals, is identical to B^*3512. B^*3512 differs from B^*3504 by 3 nucleotides and one amino acid. Substitutions in residue 95 contribute to the structure of specificity pocket F, 97 to C and E, and 156 to pockets D and E. Therefore it is possible that some of the new alleles may have different peptide binding profiles. Since differences in residue 156 have been shown to affect allorecognition and mediate GvHD, identification of such variants may have important implications in transplantation and perhaps in studies of immune responses to peptides and pathogens.     

A scenario analysis of the future residential requirements for people with mental health problems in Eindhoven

Background  

Despite large-scale investments in mental health care in the community since the 1990 s, a trend towards reinstitutionalization has been visible since 2002. Since many mental health care providers regard this as an undesirable trend, the question arises: In the coming 5 years, what types of residence should be organized for people with mental health problems? The purpose of this article is to provide mental health care providers, public housing corporations, and local government with guidelines for planning organizational strategy concerning types of residence for people with mental health problems.     

Adaptive coping strategies in patients with chronic pain conditions and their interpretation of disease

Background  

We examined which adaptive coping strategies, referring to the concept of 'locus of disease control', were of relevance for patients with chronic pain conditions, and how they were interconnected with patients' life satisfaction and interpretation of disease.