Normal and Cut-Off Values of the Cytokinesis-Block Micronucleus Assay on Peripheral Blood Lymphocytes in the Croatian General Population

Mikronukleus (MN) test na limfocitima periferne krvi jedna je od najvažnijih metoda koje se primjenjuju u citogenetičkom nadzoru. Osnovni preduvjet za primjenu nekog testa u svrhu nadzora profesionalno izloženih populacija jest poznavanje normalnih vrijednosti promatranoga biološkog pokazatelja (biomarkera) u kontrolnoj populaciji. Baze podataka na razini opće populacije moraju se redovito obnavljati novim podacima. Cilj ovog istraživanja bio je utvrditi normalne i granične vrijednosti MN-testa na limfocitima periferne krvi 200 zdravih ispitanika obaju spolova iz opće populacije Republike Hrvatske te ispitati koji čimbenici pridonose spontanom nastanku MN. Na razini istražene populacije utvrđeno je prosječno (6,90±3,32) MN (medijan 7 MN), dok je raspon pojedinačnih vrijednosti iznosio 0 do 18 MN u 1000 binuklearnih stanica. Gornja granična vrijednost dobivena izračunavanjem 95. percentila za cjelokupnu promatranu populaciju iznosi 12,5 MN na 1000 limfocita. Utvrđeno je da na spontani nastanak MN utječu spol, dob i navika pušenja. Žene u prosjeku imaju više vrijednosti svih parametara MN-testa od muškaraca, a u njih je bio i naglašeniji porast vrijednosti citogenetičkog nalaza zbog navike pušenja. Kako su literaturni podaci o utjecaju pušenja cigareta na nastanak MN kontradiktorni, planiran je nastavak istraživanja radi razjašnjavanja utjecaja dnevno utrošenog broja cigareta i ukupnog trajanja pušačkog staža na vrijednosti parametara MN-testa. Usporedba rezultata s literaturnim podacima potvrdila je da su dobivene vrijednosti u skladu s vrijednostima MN-testa zabilježenim na općoj populaciji u drugim svjetskim laboratorijima. Normalne i granične vrijednosti MN-testa utvrđene u ovome istraživanju poslužit će kao osnova za usporedbu i tumačenje nalaza MN-testa u ispitanika izloženih populacija te daljnju nadogradnju laboratorijske baze podataka.The cytokinesis-block micronucleus (CBMN) assay on peripheral blood lymphocytes is one of the most important methods employed in cytogenetic biomonitoring. For the purposes of biological dosimetry, it is important to kno the spontaneous frequency of a biomarker and its normal values in general population. These values are used for population databases, which should be updated regularly. In this study, MN levels were investigated in cytokinesis-blocked lymphocytes of 200 healthy male and female blood donors selected at random from the general population of Croatia. The aim was to assess the variability and determine possible infl uences of external and/or internal factors on the background levels of MN and to establish the cut-off value for the CBMN assay. The background frequency of MN was (6.90±3.32) MN (median 7 MN) and the range was 0 to 18 MN per 1000 binuclear lymphocytes. The cut-off value, which corresponds to 95th percentile of the distribution of 200 individual values, was 12.5 MN. Spontaneous formation of MN was infl uenced by sex, age, and smoking. Women had higher MN levels than men. However, only age and smoking signifi cantly increased the values of all parameters evaluated by the CBMN assay. Since the existing literature data on smoking-related formation of MN are contradictory, we will continue these investigations to resolve how the number of cigarettes smoked per day and the duration of smoking in years infl uence the results of the CBMN assay. Our results are consistent with the background MN frequencies reported by other cytogenetic laboratories worldwide. Normal and cut-off values estimated in this study will be used to update the current general population data and as reference for occupationally or accidental exposure

Fragile X Gene Stability in Basque Valleys: Prevalence of Premutation and Intermediate Alleles

Fragile X syndrome is the most common form of inherited mental retardation. The molecular basis is usually the unstable expansion of a CGG repeat in the FMR1 gene. We previously analyzed a sample of two Basque valleys. In the present work we extend the study to another five isolated valleys. The results show that differences in factors implicated in CGG repeat instability—CGG repeat size, XS548/FRAXAC1 haplotypes, and AGG interspersion pattern—are present in the Basque populations analyzed

Dermatoglyphic Variation in Spanish Basque Populations

The present study involves the evaluation of digital dermatoglyphic traits of 2185 unrelated individuals (1152 females and 1033 males) from 17 natural valleys of the four Basque provinces (Vizcaya, Guipúzcoa, Navarra, and Alava) in the Spanish Basque Country. Univariate intervalley and between-sex comparisons were carried out by means of chi-square contingency analysis for pattern types and by means of one-way analysis of variance for ridge counts. Multivariate intervalley comparison was carried out by means of correspondence analysis for pattern types and by principal component analysis for ridge counts. The results of this study are notable for the following findings: (1) in general, all variables are significantly heterogeneous among valley populations; (2) there was a greater differentiation among the valley populations than between sexes in one valley population; (3) affinities among the intervalley populations depend on the variables considered; (4) the valley populations from Vizcaya resemble those from the Pyrenees; (5) based on interprovince comparisons, the Vizcaya and Navarra samples are the closest; (6) in general, the valley samples from Alava are the worst clustered; (7) the universality of dermatoglyphic component structure fits better in males