Mitogen-activated protein kinase cascades in plants: a new nomenclature

Mitogen-activated protein kinase (MAPK) cascades are universal signal transduction modules in eukaryotes, including yeasts, animals and plants. These protein phosphorylation cascades link extracellular stimuli to a wide range of cellular responses. In plants, MAPK cascades are involved in responses to various biotic and abiotic stresses, hormones, cell division and developmental processes. Completion of the Arabidopsis genome-sequencing project has revealed the existence of 20 MAPKs, 10 MAPK kinases and 60 MAPK kinase kinases. Here, we propose a simplified nomenclature for Arabidopsis MAPKs and MAPK kinases that might also serve as a basis for standard annotation of these gene families in all plants.     

Congenital adrenal hyperplasia: lessons from a multinational study

A study group of paediatric endocrinologists was established in Austria, Czech Republic, Hungary, Slovenia and Slovakia in order to investigate various aspects in children with congenital adrenal hyperplasia (CAH). Five hundred and ninety-eight patients with CAH who were diagnosed between 1969 and 1998 were included in order to analyze the following questions. Epidemiological data: There were significantly fewer males (43%) than females (57%), and the percentage of males did not increase during the observation period. Salt wasters (SW) totalled 64.7%, whereas 35.3% had simple virilizing (SV) CAH. Diagnosis was established significantly later in boys than in girls (median of 26 vs. 13 days for SW, p < 0.0001; 1,817 vs. 1,010 days for SV, p < 0.03). Mortality in the general population was significantly lower than in CAH siblings (1.8% vs. 7.0%, p < 0.0001) or in SW children (2.2% vs. 11.3%, p < 0.0001). According to our calculation with the present clinical diagnostic criteria in Central Europe, from 40 expected CAH patients/year, 2-2.5 SW, and one female and four male SV patients will not be diagnosed. Auxological data: Growth data from 341 patients were analyzed retrospectively. Percentiles were constructed in a longitudinal/cross-sectional study and pubertal growth was described in a longitudinal analysis. Growth of SW patients was impaired in early childhood (0-3 years), but followed a normal course until puberty. In contrast, SV children had a normal growth pattern during early childhood, but were above the standard thereafter. The pubertal growth spurt was of normal magnitude in boys and girls, but started too early. Final height was reduced compared with both standard and target heights. There was no correlation between final height and age of starting treatment or the year of birth. Bone age was accelerated in both CAH types, but more so in SV patients. Molecular genetics: Three hundred and fifty-six patients were investigated for 11-14 of the most frequent mutations by direct allele-specific polymerase chain reaction (PCR) and/or PCR followed by sequence-specific oligonucleotide, single strand chain polymorphism and restriction fragment length polymorphism. In the group as a whole, we most frequently found the Intron 2 splice mutation (30.8%) or a deletion/conversion (28.5%). The Intron 2 mutation was most frequent in the Hungarian population, whereas deletions/conversions were found more frequently in Slovenians. The other mutations had a similar distribution to those seen in other populations. Genotype-phenotype correlation confirms previous reports.     

Evaluation of a mass screening program for lysinuric protein intolerance in the northern part of Japan

Lysinuric protein intolerance (LPI:MIM 222700) is an autosomal recessive disease characterized by defective transport of the dibasic amino acids. We recently reported a local cluster of LPI in the northern part of Japan (Koizumi et al., 2000). Mutational analysis of the LPI patients in this local cluster revealed they were exclusively homozygous for the R410X mutation. The effectiveness of early intervention with citrulline therapy (200 mg/kg per day) and protein restriction (1.5 g/kg per day) was confirmed in these patients. Mass screening was conducted in 4,568 newborn babies between 1999 and 2002, which was estimated to cover 100% of almost all newborns delivered in the screened area. Forty heterozygous newborns were found (0.88%), leading to an estimated incidence of LPI of 1:51,984. The number of people that required screening to detect one case was 51,984, and the cost for mass screening was 30 cents/person (a total of dollars 15,600). This is comparable to, or even less than, the cost of currently screened diseases in Japan. Therefore, we conclude that a mass screening program for LPI can be introduced effectively and economically into an area where an LPI cluster is located as the result of a founder mutation.     

Report of a Scientific Working Group on Serious Adverse Events following Mectizan<Superscript>®</Superscript> treatment of onchocerciasis in <Emphasis Type="Italic">Loa loa</Emphasis> endemic areas

The occurrence of Serious Adverse Experiences (SAEs) following Mectizan^® treatment of onchocerciasis in Loa loa endemic areas has been increasingly reported over the past decade. These SAEs include a severely disabling, and potentially fatal, encephalopathy, which appears to correlate with a high load of L. loa microfilariae (> 30,000 mf/ml).Previous consultations organized by the Mectizan^® Donation Program (MDP) in 1995 and 1999 have developed useful "case" definitions of encephalopathic SAEs following Mectizan^® treatment and have summarized available evidence on its pathogenesis and optimal clinical management. At both meetings, the need for better understanding of the pathogenesis of the encephalopathy was emphasized, including the need for biological and autopsy specimens from the affected cases.Following a recommendation at the Joint Action Forum of the African Programme for Onchocerciasis Control in December 2001, the MDP, on behalf of the Mectizan^® Expert Committee, organized a Scientific Working Group on L. loa associated SAEs following Mectizan^® treatment in May 2002. The present report includes the background, new evidence, conclusions and recommendations from that Scientific Working Group. The following points represent a summary of the present status:1. Although there are more and better quality clinical and epidemiological data on L. loa, the pathogenesis of the Mectizan^®-related L. loa encephalopathy remains obscure.2. Very limited progress has been made in research on the pathogenesis of encephalopathy, because of the lack of specimens from cases, and the lack of animal models.3. There has been no particular breakthrough in terms of the medical management of patients with L. loa encephalopathy; however, a favorable outcome usually results from prompt general nursing and nutritional care which remain the major interventions.The main recommendations for future actions are as follows:1. Validate and update the mapping of L. loa with a combination of remote sensing and RAPLOA techniques.2. Conduct an expert analysis of the apparent clustering of encephalopathic SAEs reported so far.3. Investigate a possible "pre-treatment" scheme with high-dose albendazole in L. loa endemic communities at high risk of encephalopathic SAEs if treated with Mectizan^®; this study will be conducted in collaboration with WHO/TDR.4. Establish a post of Loiasis Technical Advisor for research and operational support in Cameroon, to conduct population surveys and to facilitate better data collection from SAE cases, including postmortem studies as appropriate.5. Investigate the possibility of developing an animal model of L. loa encephalopathy; this activity would be linked to the above-mentioned research agenda in Cameroon.6. Investigate the best care model for encephalopathic SAEs, including identification of early warning signs and therapeutic interventions.7. Develop further models for health education messages needed for community compliance with Mectizan^® treatment, and family support for SAE cases.8. Conduct research studies on the safety of combination therapy of Mectizan^® and albendazole in areas co-endemic for L. loa and lymphatic filariasis (LF) with coordination from the relevant technical bodies that oversee these issues.The above recommendations will be implemented through a continuing collaboration between the interested parties represented at the Scientific Working Group, involved in onchocerciasis control and/or the Global Programme to Eliminate Lymphatic Filariasis.     

The "vanishing counting bead" phenomenon: effect on absolute CD34+ cell counting in phosphate-buffered saline-diluted leukapheresis samples

BACKGROUND: Using a single-platform protocol to count absolute CD34+ hematopoietic precursor cell (HPC) levels with different reference microbeads, we recorded occasionally artifactually high CD34+ HPC counts in some leukapheresis bags, whereas dual-platform calculations were always consistent. Abnormal countings were observed only when phosphate-buffered saline (PBS)-diluted leukapheresis samples were vortexed before analysis. A large series of blood samples analyzed similarly for CD34+ and CD4+ absolute counts did not show any sample or vortexing effect. With the volumetric absolute counting cytometer Partec-PAS, lower counts were also observed when different reference beads were vortexed before the instrument checking procedures. The counting abnormality was caused by a drop in microbead concentration (the "vanishing bead phenomenon"). This phenomenon reduced the total and relative bead event number in experimental and routine samples and in calibration procedures. This altered the bead denominator used to calculate absolute CD34+ HPC levels and it also reduced the concentration of standard calibration beads. METHODS: Using the Partec-PAS to measure volumetrically the actual bead concentration, we studied the vanishing bead phenomenon. Different types of counting and reference microbeads were resuspended in media with or without proteins or cells. Replicates were submitted either to gentle manual mixing or to vortexing before counting. RESULTS: Vortex agitation almost invariably induced the vanishing bead phenomenon when beads were resuspended in saline media or when an insufficient protein concentration was present, such as in diluted leukapheresis samples. Different bead types showed various degrees of sensitivity to vortexing. The bead disappearance was not caused by bubble formation or disruption. The addition of small amounts of protein completely prevented the vanishing bead phenomenon. The causative effect of the electrostatic charging of tube induced by vortexing is hypothesized. CONCLUSIONS: Sample suspensions containing counting beads for single-platform analysis must be resuspended in media with protein supplements to prevent the vanishing bead phenomenon and to ensure accurate counting.     

Genomewide search for type 2 diabetes susceptibility genes in four American populations

Type 2 diabetes is a serious, genetically influenced disease for which no fully effective treatments are available. Identification of biochemical or regulatory pathways involved in the disease syndrome could lead to innovative therapeutic interventions. One way to identify such pathways is the genetic analysis of families with multiple affected members where disease predisposing genes are likely to be segregating. We undertook a genomewide screen (389-395 microsatellite markers) in samples of 835 white, 591 Mexican American, 229 black, and 128 Japanese American individuals collected as part of the American Diabetes Association's GENNID study. Multipoint nonparametric linkage analyses were performed with diabetes, and diabetes or impaired glucose homeostasis (IH). Linkage to diabetes or IH was detected near markers D5S1404 (map position 77 cM, LOD = 2.80), D12S853 (map position 82 cM, LOD = 2.81) and GATA172D05 (X-chromosome map position 130 cM, LOD = 2.99) in whites, near marker D3S2432 (map position 51 cM, LOD = 3.91) in Mexican Americans, and near marker D10S1412 (map position 14 cM, LOD = 2.39) in African Americans mainly collected in phase 1 of the study. Further analyses showed evidence for interactions between the chromosome 5 locus and region on chromosome 12 containing the MODY 3 gene (map position 132 cM) and between the X-chromosome locus and region near D12S853 (map position 82 cM) in whites. Although these results were not replicated in samples collected in phase 2 of the GENNID study, the region on chromosome 12 was replicated in samples from whites described by Bektas et al. (1999).     

Using the number of koilocytes to predict HIV serostatus in women with HPV-associated SIL

OBJECTIVE: To investigate the relationship between specific cytopathologic changes, koilocyte counts and human papillomavirus (HPV) types in HIV-positive and -negative women. STUDY DESIGN: A cohort of 459 women (266 HIV+ and 193 HIV-), were examined in a multicentric study (Early Diagnosis of Neoplasia in AIDS) involving 14 gynecologic centers. Altogether, 97 women had cervical smears consistent with squamous intraepithelial lesions (SIL). Koilocytes were found in 60/97 SIL slides, subjected to quantitative counting in 30 predetermined fields. HPV genotype was determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. RESULTS: SIL lesions were four times more frequent (29%) in HIV-positive women than in HIV-negative women (10%) (odds ratio = 3.80). HPV DNA was equally frequent in both groups. There was a strong association between the number of koilocytes and HIV serostatus in both high grade and low grade SIL diagnoses. The presence of eight or more koilocytes had a specificity of 93% and sensitivity of 76% toward the diagnosis of HIV-positive status. No HIV-negative woman had a count > 8 koilocytes. No association was shown between koilocyte count and HPV genotype. CONCLUSION: An elevated number of koilocytes could suggest the possibility of HIV infection. Pap smear examination might give the first clue to HIV positivity in otherwise-unsuspected cases.     

The intercellular adhesion molecule-1 K469E polymorphism in type 1 diabetes

Type 1 (insulin-dependent) diabetes is a complex trait. The region harboring the ICAM1 gene on 19p13 links to type 1 diabetes, and a growing body of evidence indicates that intercellular adhesion molecule-1 (ICAM-1) could play a role in type 1 diabetes development. Recently, association studies of an ICAM-1 K469E polymorphism in type 1 diabetes populations have reported conflicting results. Hence, we performed a transmission disequilibrium test analysis of the ICAM-1 K469E variations in 253 Danish type 1 diabetes families. Linkage and association was not found between the ICAM-1 K469E variation and type 1 diabetes in Danish patients (P(tdt)> or =0.48), and our data did not indicate an interaction between ICAM1 and IDDM1 in predisposition to type 1 diabetes in Danes (P=0.78). We did not observe significant association with late-onset type 1 diabetes (P(tdt)> or =0.12) or differences in transmission patterns between groups of affected offspring stratified for age at onset (P> or =0.19), as suggested in Japanese patients. Combined analysis of the present and previously reported transmission data comprising 728 affected offspring of Romanian, Finnish, and Danish ancestry suggested association between the ICAM-1 E469 allele and type 1 diabetes (P(tdt)=0.013), but association was not found in the combined Scandinavian material. In conclusion, we found no association of the ICAM-1 K469E polymorphism with type 1 diabetes or its subsets stratified for age at onset and HLA risk in Danish patients. Analysis of ICAM-1 K469E transmissions reported in three populations suggested association to type 1 diabetes, but also demonstrated heterogeneity between populations.