Male haplotypes and haplogroups differences between urban (Rimini) and rural area (Valmarecchia) in Romagna region (North Italy)

The distribution of Y chromosomal haplotypes and haplogroups in two different population samples from the Romagna region (North Italy) was performed. One population sample was collected in the urban area of Rimini, an ancient port in Roman age and the other one in the near and geographically more isolated rural area of Valmarecchia. Fast and slow evolving markers have been studied to infer population history and to analyse the microgeographic heterogeneity of Y chromosome in a Northern Italian region. Haplotype variability values compared to those observed in a Central Italy sample from the other side of Apennine mountains and in an Austrian population sample were very similar.

Minisequencing-based genotyping of Duffy and ABO blood groups for forensic purposes

Duffy and ABO blood group genetic polymorphisms were studied by minisequencing analysis of single-nucleotide polymorphisms (SNPs) at nucleotide positions--33, 125, 265, and 298 of the Duffy gene and at nucleotide positions-261, 297, 467, 646, and 703 of the ABO gene. In an Italian population sample, we found four alleles and seven genotypes for the Duffy and six alleles and 16 genotypes for the ABO systems. The lower limit for reproducible results was 200 pg DNA, with a range of up to 10 ng and an optimum at 1 ng. All of the 16 analyzed inclusive paternity tests were also consistent with parentage and two out of four inconsistencies with parentage cases were excluded by one or more SNPs. Although Duffy and ABO SNP typing show lower informativeness than most current forensic tests, their robustness, the limited population distribution of FY* Fy type, and the sensitivity of the minisequencing technology suggest that these markers can be useful in selected forensic applications.

Development of a heptaplex PCR system to analyse X-chromosome STR loci from five Italian population samples. A collaborative study

Many X-chromosome short tandem repeats (X-STRs) have been validated for forensic use even if further studies are needed on allele frequencies and mutation rates to evaluate the extent of polymorphism in different populations and to establish reference databases useful for forensic applications and for anthropological studies. A single multiplex reaction of seven X-STRs, which includes the DXS6789, HUMARA, DXS10011, DXS7423, HPRTB, DXS6807, DXS101 loci, is presented and their allele frequency distribution in a large population sample including 556 subjects (268 females and 288 males) analysed by five forensic laboratories of Central and Northern Italy is shown. Our results demonstrate the feasibility of a single amplification/detection reaction involving seven markers of the X chromosome, which can be fruitfully used in complex kinship analysis.

Morphological and phenotypical characterization of Bacillus sporothermodurans

AIMS

Enumeration of resistant bacteria in ultra-high temperature (UHT) treated milk; morphological characterization and phenotyping of resistant strains by traditional and nontraditional methods and their identification by molecular biology.

METHODS AND RESULTS

Modified standard plate count agar (PCA) and modified brain-heart infusion (BHI) agar were used for colony counts. Physiological culture traits were determined as suggested by Bergey's Manual of Systematic Bacteriology or in modified J-broth or in modified BHI agar. Scanning electron microscope (SEM) was used for microscopic examination. Strain identification was carried out by polymerase chain reaction (PCR). A total of 125 (62.81% of 199) samples were positive and the bacterial load was higher than 10(5) CFU ml(-1) in 46 samples (28.80% of 125). The 16S rRNA sequence of bacterial cultures obtained from UHT-treated milk was similar to that of Bacillus sporothermodurans M215 type strain((T)) and different biotypes were found by analysis of colony appearance, cell morphology and physiological traits.

CONCLUSIONS

Bacillus sporothermodurans was the predominant sporigenous micro-organisms in UHT milk.

SIGNIFICANCE AND IMPACT OF THE STUDY

BHI agar is more suitable than PCA for quality control of milk after UHT treatment. Modified J-broth medium is useful to determine selected physiological traits of B. sporothermodurans. The strains characterized and identified as B. sporothermodurans were significantly different compared with the type strain.

Sex chromosome analysis in Turner Syndrome by a pentaplex PCR assay

In this study, we describe a pentaplex PCR to determine the parental origin of the X chromosome and the presence of mosaicism, via amplification of four polymorphic markers located along the X chromosome (DXS10011, DXS6807, HUMARA, DXS101) and the X-Y amelogenin marker, in 41 families having a daughter with Turner Syndrome. Our results confirmed the cytogenetic findings and we found that the parental origin of the single X chromosome to be maternal in 84% of cases.

Different informativeness of the three hypervariable mitochondrial DNA regions in the population of Bologna (Italy)

Mitochondrial DNA (mtDNA) sequence variations at hypervariable regions HVI, HVII and HVIII were analysed in 100 unrelated Italians from Bologna. The values of the statistical parameters are in agreement with the range of European populations. We suggest that the less informative HVIII region may be useful to distinguish HVI-HVII identical sequences in forensic analysis especially when nuclear DNA cannot be investigated.

The HUMFIBRA (FGA) polymorphism in an italian population and a world-wide frequency distribution analysis

OBJECTIVE

The study investigated the highly polymorphic HumFGA short tandem repeat in a sample of 219 unrelated and native individuals from Bologna, and analysed a complete database of FGA allele frequency distributions in 57 world-wide populations collected from the literature.

METHOD

The HumFGA polymorphism was screened by automated fluorescence analysis of PCR-amplified labelled sample fragments performed with an ABI PRISM 310 Genetic Analyser. Genetic distances (Dsw, delta mu2 and Fst) between populations were computed with the MSAT.2 program. Non-metric multidimensional scaling (nmMDS) and neighbour-joining trees (NJTs) were used to investigate patterns of population affinities. Correspondence analysis of the genetic relationships among populations was also performed.

MAIN RESULTS AND CONCLUSIONS

The FGA microsatellite locus is a population marker with a high degree of polymorphism throughout the world. Fourteen HumFGA alleles, ranging in size from 18 to 29 repeats, were identified and sequenced in the Bologna population. The sample was in Hardy-Weinberg equilibrium and had a heterozygosity value of 0.86. Results obtained from the multivariate analyses were consistent in showing great similarity among Europeans. The few African populations investigated were characterized by an even higher level of polymorphism, probably related to the ancient peopling of that continent.

Removal of the N-terminal hexapeptide from human beta2-microglobulin facilitates protein aggregation and fibril formation

The solution structure and stability of N-terminally truncated beta2-microglobulin (deltaN6beta2-m), the major modification in ex vivo fibrils, have been investigated by a variety of biophysical techniques. The results show that deltaN6beta2-m has a free energy of stabilization that is reduced by 2.5 kcal/mol compared to the intact protein. Hydrogen exchange of a mixture of the truncated and full-length proteins at microM concentrations at pH 6.5 monitored by electrospray mass spectrometry reveals that deltaN6beta2-m is significantly less protected than its wild-type counterpart. Analysis of deltaN6beta2-m by NMR shows that this loss of protection occurs in beta strands I, III, and part of II. At mM concentration gel filtration analysis shows that deltaN6beta2-m forms a series of oligomers, including trimers and tetramers, and NMR analysis indicates that strand V is involved in intermolecular interactions that stabilize this association. The truncated species of beta2-microglobulin was found to have a higher tendency to self-associate than the intact molecule, and unlike wild-type protein, is able to form amyloid fibrils at physiological pH. Limited proteolysis experiments and analysis by mass spectrometry support the conformational modifications identified by NMR and suggest that deltaN6beta2-m could be a key intermediate of a proteolytic pathway of beta2-microglobulin. Overall, the data suggest that removal of the six residues from the N-terminus of beta2-microglobulin has a major effect on the stability of the overall fold. Part of the tertiary structure is preserved substantially by the disulfide bridge between Cys25 and Cys80, but the pairing between beta-strands far removed from this constrain is greatly perturbed.

Conformational dynamics of the beta2-microglobulin C terminal in the cell-membrane-anchored major histocompatibility complex type I

We have recently described an anti-beta2-microglobulin (beta2-m) monoclonal antibody (mAb 14H3) capable of recognizing the epitope 92-99 of the protein in the monomeric native state as well as in the fibrillar polymeric state, but not in the major histocompatibility complex type I (MHCI) anchored to the cell membrane. In the present study, we investigated the molecular basis for the inaccessibility of the C-terminal end of beta2-m in the MHCI complex, and demonstrated that mAb 14H3 binds the soluble fraction of the MHCI complex with a Kd of 0.3 microM. An interaction between the complex and the membrane protects beta2-m from immunological recognition at the MHCI level. This protection from antibody recognition can be weakened by procedures such as heat shock or gamma irradiation that perturb the membrane structure and commit the cell to the apoptotic pathway. mAb 14H3 can recognize MHCI in a transient state that most likely precedes beta2-m shedding and may be proposed as a useful tool for dynamic analysis of MHCI conformational modifications.

Myotonic dystrophy CTG repeats in an Italian population sample: evaluation of the polymorphism for forensic applications

The myotonic dystrophy (DM) CTG repeat polymorphism has been studied in an Italian population sample. Polymerase chain reaction (PCR) amplification, manual polyacrylamide gel electrophoresis (PAGE), and silver staining were employed. Alleles were typed by comparison with a sequenced allelic ladder. A total of 25 different alleles, spanning the range from 5 to 31 CTG triplets, was observed. The heterozygosity was 79%, and no significant deviation from Hardy-Weinberg equilibrium was found. Eighty-one meioses from parentage testing were also analyzed, and a Mendelian pattern of inheritance was observed in all cases. In addition, we could successfully type the DM locus in 20 laboratory-prepared bloodstains, with 1 ng of DNA allowing clear definition of alleles. We conclude that the CTG repeats at the DM locus may be useful for forensic applications.

Management of animal health emergencies: general principles and legal and international obligations

The Eighth Round of the General Agreement on Tariffs and Trade led to the creation of the World Trade Organization and to the adoption of the Sanitary and Phytosanitary (SPS) Agreement, thus considerably changing the rules of international trade in animals and animal products. Animal health measures may result in trade restrictions, but governments accept that these restrictions may sometimes be necessary and appropriate to ensure food safety and animal health protection. The SPS Agreement acknowledges the rights of governments to adopt measure to protect human, animal and plant health. To ensure effective animal health protection, without unjustifiable discrimination, the operational procedures of Veterinary Services must be standardised, especially those concerning disease notification, epidemiological information, certification for international trade and management of animal health emergencies. Veterinary Services must be further supported by a proper legislative framework and adequate financial resources.

Beta2-microglobulin can be refolded into a native state from ex vivo amyloid fibrils

Beta2-microglobulin fibrils have been extracted from the femoral head of a patient who has been under chronic haemodialysis for 11 years. The primary structure of the N-terminal portion of the protein and mass determination by electrospray mass spectrometry demonstrate that beta2-microglobulin, extracted as fibrils by the water extraction procedure, was not glycated and that Asn17 was not deamidated. Limited proteolysis was observed in more than 20% of beta2-microglobulin molecules and the main cleavage sites were at the C-terminus of Lys6 and Tyr10. Beta2-microglobulin from fibrils has been purified by gel filtration in 6 M Gdn/HCl and submitted to a refolding procedure. The refolding conditions have been determined through the study of the unfolding pathway of the native protein. Beta2-microglobulin is stable at neutral pH where it displays a lower tendency to self-aggregate than in acidic conditions. Pulse dilution and extensive dialysis in refolding buffer at pH 7.5 yields beta2-microglobulin with a tertiary structure identical to that of the native form. The CD spectrum in the near-ultraviolet region and the spectrum of the intrinsic fluorescence of Trp overlap those of the native protein, but the CD spectrum in the far-ultraviolet region is affected by the contribution of oligomers created by beta2-microglobulin fragments that reduce the positive light polarisation at 205 nm typical of native beta2-microglobulin.

Determination of HPRT mutant frequency and molecular analysis of T-lymphocyte mutants derived from coke-oven workers

We measured the frequency of mutant (MF) lymphocytes at the hprt locus in a population of 43 coke-oven workers exposed to PAH and in a group of 26 non-exposed workers. A non-significant increase in MF in the exposed group (19.0 +/- 16.3) compared to the non-exposed group (15.8 +/- 14.6) was observed. Moreover, when we considered smoking habits for the overall population, the MF values were higher, although not significantly, in smokers than in non-smokers. For some T-cell mutant clone structural alterations, splicing and coding errors were detected by PCR-based methods. We analysed 161 HPRT- clones, derived from exposed and non-exposed workers by multiplex-PCR and 56 HPRT- clones by reverse transcriptase-PCR. Overall, the percentages of the different types of gene alterations were similar in exposed and non-exposed subjects. Only the frequency of splice mutations in mutant clones derived from coke-oven workers was higher (22%) than in non-exposed donors (11%).

Use of anti-(beta2 microglobulin) mAb to study formation of amyloid fibrils

Three mAbs, IgG1k 1F11, 7B6 and 14H3, were raised against in vitro-self-aggregated beta2-microglobulin. They recognize the native and unfolded forms of the protein and bind its fibrillar form that is present in amyloid tissue. When assayed in fibrillogenesis tests in vitro, mAb 14H3 inhibited fibril formation from beta2-microglobulin. This mAb recognizes a sequential epitope corresponding to the C-terminal octapeptide, residues 92-99, of beta2-microglobulin. By using synthetic peptides it has been found that the integrity of the sequence is essential for the formation of the immunocomplex: the binding affinity is lowered by one order of magnitude (Kd from 10(-7) M to 10(-6) M) by removal of Met99 and completely abolished when both Asp98 and Met99 are lost or Arg98 is substituted with Lys. The other two mAbs, 1F11 and 7B6, which bind sequences 20-41 and 63-75, respectively, are without effect on beta2-microglobulin fibrillogenesis. These two mAbs recognize beta2-microglobulin bound to the heavy chain in the major histocompatibility complex of type I located in the cell membrane, a property which is not shared by mAb 14H3.

Structural and functional characterization of three human immunoglobulin kappa light chains with different pathological implications

The structural properties of three immunoglobulins light chains: kappa SCI, responsible for light chain deposition disease (Bellotti, V., Stoppini, M., Merlini, G., Zapponi, M.C., Meloni, M.L., Banfi, G. and Ferri, G. (1991) Biochim. Biophys. Acta 1097, 177-182), k INC responsible for light chain amyloidosis (Ferri, G., Stoppini, M., Iadarola, P., Bellotti, V. and Merlini, G. (1989) Biochim. Biophys. Acta 995, 103-108) and the non-pathogenic kappa MOS were analyzed by fluorescence spectroscopy and circular dichroism. Comparative evaluation of the data shows that SCI and MOS have similar stability under different conditions, while the amyloid k INC behaves as a very unstable protein. As calculated from the GdnHCl curves, the midpoint of unfolding transition was 1.35 M for SCI, 1.20 M for MOS and 0.1 M for INC. Analysis of CD spectra evidences that the three proteins conserve their conformation in the range of pH 4-8. Change in temperature at pH 4.0 produces the premature transition of INC (Tm 40 degrees C) with respect to SCI and MOS (Tm 50 degrees C). At this pH both the pathological SCI and INC light chains aggregate at a temperature of 20 degrees C lower than the normal counterpart. The specific kidney deposition of kappa SCI has been evidenced after injection of the 125I labelled light chain into mice. No deposition was detectable in the case of INC and MOS.

Cytogenetic studies in coke oven workers

Chromosome aberrations, micronuclei, and sister chromatid exchanges (SCE) were evaluated in cultured lymphocytes of coke oven workers of an Italian steel industry plant, occupationally exposed to polycyclic aromatic hydrocarbons, and in a group of unexposed controls from a non-oven plant in the same area. No differences were found between exposed and controls for rates of total abnormal metaphases (including and excluding gaps), chromatid-type and chromosome-type aberrations, cells with 2 or more breaks, and for micronuclei. On the contrary, SCE were significantly increased in the exposed versus the controls, but, when smoking habits were considered, the increase was significant only for smokers.