ALPHA- AND BETA-GLOBIN GENE MUTATIONS IN GEORGIA AND ARMENIA.

Georgia and Armenia are situated at the northern rim of the thalassemia belt and bordering to countries with a known high prevalence of thalassemias. In this study we assessed the carrier frequency and potential spectrum of alpha- and beta-globin mutations among 202 and 190 unselected Georgian and Armenian subjects, respectively. We found four alpha-globin mutations (-3.7del, -4.2del, anti-3.7 triplication, poly-A2) in 9 Armenians (4.74%) and 4 Georgians (1.78%). The heterozygous beta-globin codon 8 [-AA] mutation was detected in one individual from Armenia only. Overall, carrier frequencies seem to be low in both countries, supporting the notion that thalassemias are not a major health problem there.

Assessment of vitamin D status and serum CrossLaps levels in adults with primary lactose malabsorption.

BACKGROUND/OBJECTIVES: Primary adult-type lactose malabsorption (PALM) is a widespread inherited autosomal recessive condition, which is considered to be associated with osteoporosis. This prospective study aimed at assessing the 25-hydroxy-vitamin D (25(OH)D) status and serum CrossLaps levels in individuals with PALM and normal controls. SUBJECTS/METHODS: All participants (n=210) underwent genotyping for the LCT C/T-13910 polymorphism, 25(OH)D and CrossLaps measurements and clinical examinations. In addition, the anthropometric data (that is, height, weight and body mass index) were determined. RESULTS: Fifty-five individuals with PALM (that is, LCT C/C-13910 homozygotes) showed lower 25(OH)D (mean: 24.95±10.04 vs 28.59±9.56 ng/ml, P=0.018) and higher CrossLaps serum levels (mean: 0.46±0.31 vs 0.43±0.49 ng/ml, P=0.251) compared with 155 normal controls (that is, LCT C/T-13910 hetero- or T/T-13910 homozygotes). Anthropometric data were similar between PALM probands and controls. CONCLUSIONS: Individuals with PALM were found to have lower 25(OH)D and higher CrossLaps serum levels compared with normal controls. In order to preserve life-long bone health, routine 25(OH)D and CrossLaps serum measurements should be performed in individuals with PALM.

Familial Mediterranean fever in Georgia.

Familial Mediterranean Fever (FMF) is a hereditary autoinflammatory disorder caused by mutations in the MEFV gene. Carrier rates are known to be particularly high among Sephardic Jews, Turks, Armenians and Arab populations. Our literature survey regarding FMF and MEFV mutations in Georgia revealed a lack of existing studies. We applied multiplex PCR and reverse-hybridization teststrips (FMF StripAssay) to simultaneously analyze twelve common MEFV mutations in DNA samples from dried blood on filter cards, which had been obtained from 202 unselected newborns at various hospitals in Tbilisi, Georgia. We found 30 samples to be heterozygous and one to be compound heterozygous or carrier of a complex allele (two mutations in cis). The carrier rate of MEFV mutations (15.3%) was remarkable. The most frequently observed variants were E148Q (15x), M680I G/C (5x) and M694V (4x). Five other MEFV mutations were found at lower prevalence (V726A, A744S, R761H: 2x each; P369S, F479L: 1x each). Based on these new findings, the awareness for FMF and the availability of appropriate testing should be further promoted in Georgia.

BRAF mutational epidemiology in dysplastic nevi: does different solar UV radiation exposure matter?

BACKGROUND: Proto-oncogene B-Raf (BRAF) mutation rates have been reported in nevi and melanomas of homogeneous Caucasian cohorts. OBJECTIVE: To study the demographics of BRAF mutations in dysplastic nevi of populations with differing potential solar UV radiation exposure. METHODS: Extended BRAF testing for 9 mutations in 125 dysplastic nevi from 101 patients, derived from populations with differing potential UV radiation exposure rates (Lebanon and Saudi Arabia), was performed. Clinical and microscopic parameters were recorded. RESULTS: BRAF mutation status was carried out for 101/125 (80.8%) cases with an overall mutation rate of 62.4% (63/101). V600E (c.1799T > A) was the predominant mutation, found in 61/63 (96.8%) cases. BRAF mutation rate differed significantly by potential UV radiation exposure (Lebanon: 53.4%, Saudi Arabia: 74.4%, P < 0.05). A 43.8% discordant mutation rate (7/16 patients) was found in patients with multiple nevi, including 2 patients with different BRAF mutations. Microscopic examination subdivided the dysplasia into mild (n = 24), moderate (n = 60) and severe (n = 41) with trunk predominance (72.8%). Higher rates of pigment in the stratum corneum were identified in Saudi Arabia (P < 0.05). No statistical significant increase in BRAF mutation rate was noted with advanced architectural and cytological atypia. Parameters associated with a negative BRAF mutation status included upper extremity location, regression, cohesiveness and presence of suprabasal melanocytes (P < 0.05). Positive BRAF mutation status was reasonably predicted by multivariate binary logistic regression by 2 independent predictors: Geographic location and compound nevus type. CONCLUSIONS: In our Near Eastern cohort, the BRAF mutation rate varied significantly by geographic location. In patients with multiple dysplastic nevi examined, discordant BRAF mutation status potentially negates an underlying constitutional predilection.

Prevalence of neutralizing antibodies to Equine rhinitis A and B virus in horses and man.

Equine rhinitis viruses (ERVs) are the causative agents of mild to severe upper respiratory infections in horses worldwide. Immunologically, four serotypes of ERVs have been identified. Equine rhinitis A virus (ERAV) and Equine rhinitis B virus 1 (ERBV1) are the most frequent serotypes in Europe. Both viruses have a broad host range in cultured cells with ERAV being able to infect humans. Since there is neither information on the seroprevalence of ERAV and ERBV1 in Austria nor on the zoonotic potential of ERBV1, we investigated 200 horse and 137 veterinary sera for the presence of neutralizing antibodies relating to ERAV and ERBV1. One hundred and eighty (90%) and 173 (86%) horse sera neutralized ERAV and ERBV1, respectively. In contrast, only four (2.7%) and five (3.6%) human sera showed weak neutralizing activity to ERAV and ERBV1, respectively. These results indicate that ERAV and ERBV1 are widespread in the Austrian horse population; however, the risk of acquiring zoonotic infection among veterinarians appears low.

Pullulanase from the hyperthermophilic bacterium Thermotoga maritima: purification by beta-cyclodextrin affinity chromatography.

This is the first report about the isolation of a type I pullulanase from a hyperthermophilic bacterium, Thermotoga maritima strain MSB8. Purification of the enzyme from a cleared cell-free extract was achieved by anion-exchange chromatography and beta-cyclodextrin affinity chromatography. Using this convenient two-step method we have purified the pullulanase 406-fold with a 26% yield. The purified enzyme displayed maximum pullulan hydrolysis at pH 5.9 and 90 degrees C (15-min assay) and was remarkably resistant against thermoinactivation, having a half-life at 90 degrees C of about 3.5 h. To our knowledge, the T. maritima pullulanase is the most thermostable type I pullulanase known to date. The affinity-based purification protocol described here may be useful for the efficient isolation of other pullulanases.

Isolation and analysis of genes for amylolytic enzymes of the hyperthermophilic bacterium Thermotoga maritima.

In addition to the previously identified 4-alpha-glucanotransferase gene mgtA and the alpha-amylase gene amyA of Thermotoga maritima strain MSB8 we have now isolated three further genes encoding amylolytic enzymes from a gene library of this ancestral bacterium. The genes code for the extremely thermostable enzymes pullulanase (pulA), maltodextrin phosphorylase (agpA) and alpha-glucosidase (aglA) and have the potential to encode polypeptides with calculated molecular masses of 96.3 kDa, 96.1 kDa and 52.5 kDa, respectively. Comparative amino acid sequence analysis revealed that PulA and AgpA are clearly related to other known enzymes with similar function. AglA, on the other hand, was not related to other alpha-glucosidases but appears to belong to an enzyme family containing alpha-galactosidases and 6-phospho-beta-glucosidases. Enzyme properties are reported which demonstrate the extreme thermostability of these T. maritima enzymes.