Evaluation of Y-chromosomal STRs: a multicenter study

A multicenter study has been carried out to characterize 13 polymorphic short tandem repeat (STR) systems located on the male specific part of the human Y chromosome (DYS19, DYS288, DYS385, DYS388, DYS389I/II, DYS390, DYS391, DYS392, DYS393, YCAI, YCAII, YCAIII, DXYS156Y). Amplification parameters and electrophoresis protocols including multiplex approaches were compiled. The typing of non-recombining Y loci with uniparental inheritance requires special attention to population substructuring due to prevalent male lineages. To assess the extent of these subheterogeneities up to 3825 unrelated males were typed in up to 48 population samples for the respective loci. A consistent repeat based nomenclature for most of the loci has been introduced. Moreover we have estimated the average mutation rate for DYS19 in 626 confirmed fatherson pairs as 3.2 x 10(-3) (95% confidence interval limits of 0.00041-0.00677), a value which can also be expected for other Y-STR loci with similar repeat structure. Recommendations are given for the forensic application of a basic set of 7 STRs (DYS19, DYS3891, DYS389II, DYS390, DYS391, DYS392, DYS393) for standard Y-haplotyping in forensic and paternity casework. We recommend further the inclusion of the highly polymorphic bilocal Y-STRs DYS385, YCAII, YCAIII for a nearly complete individualisation of almost any given unrelated male individual. Together, these results suggest that Y-STR loci are useful markers to identify males and male lineages in forensic practice.

Chromosome Y microsatellites: population genetic and evolutionary aspects

By means of a multicenter study, a large number of males have been characterized for Y-chromosome specific short tandem repeats (STRs) or microsatellites. A complete summary of the allele frequency distributions for these Y-STRs is presented in the Appendix. This manuscript describes in more detail some of the population genetic and evolutionary aspects for a restricted set of seven chromosome Y STRs in a selected number of population samples. For all the chromosome Y STRs markedly different region-specific allele frequency distributions were observed, also when closely related populations were compared. Haplotype analyses using AMOVA showed that when four different European male groups (Germans, Dutch, Swiss, Italians) were compared, less than 10% of the total genetic variability was due to differences between these populations. Nevertheless, these pairwise comparisons revealed significant differences between most population pairs. Assuming a step-wise mutation model and a mutation frequency of 0.21%, it was estimated that chromosome Y STR-based evolutionary lines of descent can be reliably inferred over a time-span of only 1950 generations (or about 49,000 years). This reduces the reliability of the inference of population affinities to a historical, rather than evolutionary time scale. This is best illustrated by the construction of a human evolutionary tree based on chromosome Y STRs in which most of the branches connect in a markedly different way compared with trees based on classical protein polymorphisms and/or mtDNA sequence variation. Thus, the chromosome Y STRs seem to be very useful in comparing closely related populations which cannot probably be separated by e.g. autosomal STRs. However, in order to be used in an evolutionary context they need to be combined with more stable Y-polymorphisms e.g. base-substitutions.

Histone modification in early and late Drosophila embryos

Levels of histone acetylation and phosphorylation have been contrasted in two developmental states of Drosophila melanogaster. The 0-2 h nuclei of the syncitial blastula are characterized by rapid mitoses and DNA replication, but there is very little transcription. In the 18 h embryo there is considerable transcription and the mitotic rate is much slower. It has been found that (1) histone H1 from 2h nuclei is not highly phosphorylated. This observation is not in accord with the view that H1 hyperphosphorylation is essential to mitosis, but is compatible with the hypothesis that H1 phosphorylation in Drosophila species is related to heterochromatization. (2) Histone H4 from 2 h embryos shows high levels of the diacetyl form (H4-Ac2), which is principally outside the nucleus. This accords with the hypothesis that H4-Ac2 is the form in which H4 is deposited on to newly replicated DNA and shows that H4 acetylation is linked not only to transcription. (3) Histone H3 acetylation is similar in 2h and in 18h embryos. As with H4, this acetylation probably correlates with chromatin assembly and is not transcription-related. (4) Histone H2B carries no modification in 2h or in 18h embryos, and H2A shows a single modification in 2h embryos and two in 18 h embryos. H2B modification is thus not essential either in mitosis or replication, whereas H2A modification is important in one or both processes. (5) The nucleosomal protein D2 is equally present in 2h and 18 h embryos.

Wide-spectrum antibiotic activity of bovine granulocyte polypeptides

The antibiotic activity of a polypeptide fraction purified from bovine granulocyte granules was tested against Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Bacillus subtilis, Bacillus stearothermophilus, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus faecalis, Streptococcus pyogenes, and clinical isolates of Staphylococcus and Enterobacter spp. All of these bacterial species were susceptible to the antibiotic polypeptide(s), with MICs ranging from 3 to 100 micrograms of protein per ml. The antimicrobial activity was resistant to boiling and abolished by proteinase treatment. Saccharomyces cerevisiae and human fibroblasts grew normally in the presence of 100 and 50 micrograms of antibiotic polypeptide(s) per ml, respectively. [3H]thymidine incorporation into bacterial, but not fibroblast, DNA was efficiently and promptly inhibited by the antimicrobial polypeptide preparation. This suggests that its main target is a component of the system, which catalyzes and regulates the biosynthesis of bacterial DNA.

The effect of immersion on haemodynamic and fetal measures in uncomplicated pregnancies of nulliparous women

OBJECTIVE

To evaluate the effect of immersion in water on maternal haemodynamic measures and fetal heart rate patterns in healthy nulliparous women.

DESIGN

A randomised cross-over study.

PARTICIPANTS

Twenty pregnant women were studied between 26-29 weeks and between 34-37 weeks of gestation.

METHODS

The women were either immersed in water for 35 minutes or rested on a bed for a similar period of time. Maternal blood pressure, thoracic electrical bioimpedance, urine and blood samples, and fetal heart rate patterns were obtained before and after immersion or bedrest.

RESULTS

Compared with bedrest and pre-immersion values, immersion resulted in a significant decrease in blood pressure, which returned to baseline values within 1.5 hour. Urine production increased for a short period after immersion, but 24 hour samples showed no difference compared with bedrest. Sodium, potassium and creatinine levels in urine remained constant. No significant changes were found for the other haemodynamic measures. There were no effects on fetal heart rate nor on its variation.

CONCLUSION

In healthy pregnant women immersion for 35 minutes has a clear effect on blood pressure and urine production. However, these effects are short lasting.

Sex identification by polymerase chain reaction of alpha-satellite in aged tissue samples

In vitro amplification of the alphoid repeated sequences clustered in the centromeric regions of the human X and Y chromosomes was carried out. A modification of the amplification conditions reported by Witt and Erickson gave clear amplification bands from 10 pg of genomic DNA template. Results were obtained from the following aged tissue samples: 1 microL three-year-old blood stain, one-year-old single hair roots, six-month-old saliva stains and twelve-year-old bone fragments. Good results were obtained even when the template was artificially fragmented into fragments of less than 1 kbp.

Restriction endonuclease analysis of four Borrelia burgdorferi strains

A restriction endonuclease analysis was performed on four strains of Borrelia burgdorferi: one isolated from man (SF), one from Ixodes dammini (B31) and two from I. ricinus (BITS in Italy and B45 in Germany). Digestion by Taq I and Hae III gave the best resolution of the DNA fragments. Three different restriction patterns were obtained: BITS and B45 showed only one band difference. These results correlate with the reactivity of the four strains with monoclonal antibodies.

Risk factors in coronary artery bypass surgery for patients 40 years of age and younger

In patients undergoing coronary artery bypass surgery while under 40 years of age, prevalence of risk factors for coronary artery disease and prognostic factors for mortality were assessed. Ninety-four patients of such age were operated from 1979 until 1989. Eighty-two patients were male, 12 female. Fifty-eight patients (62%) had a history of myocardial infarction. Patients were predominantly in New York Heart Association class II or III (69%). In this study prevalence of risk factors for coronary artery disease was different compared to studies of patients undergoing coronary artery bypass grafting over 40 years of age. Smoking (83%), hypercholesterolaemia (79%), and positive family history for coronary heart disease (66%) were more prevalent in this study compared to other studies concerning patients older than 40 years of age whereas the occurrence of hypertension (25%) and diabetes (6%) was lower. Six patients (6%) had one-vessel disease, 15 patients (17%) had two-vessel disease and 73 patients (78%) showed triple-vessel disease. Similar studies of patients older than 40 years of age showed a lower prevalence of triple vessel disease than in this study. Hospital mortality amounted to 3 patients (3%). Five-year-survival rate was 93%. Multivariate survival analysis revealed left main stenosis and concomitant operations as significant prognostic factors of survival. Number of vessels diseased, sex, priority of operation, reoperation, or impaired left-ventricular function were not prognostic factors for mortality in this study.

Sex determination and species exclusion in forensic samples with probe cY97

A total of 120 human samples of blood, saliva and semen stains, hair roots, bone and skin fragments, obtained from 30 males and 16 females were analyzed in Southern blots with probe cY97. Only the male samples gave a specific band of 5.7 kb. In dot blot, under high stringency conditions, male DNA gave signals equivalent to a quantity of female DNA eight times higher. Probe cY97 did not react with 9 different vertebrate species but gave a signal for monkey DNA when used at low stringency. The advantage of using a probe specific for the centromeric region for sex determination and species exclusion is discussed.

Osmium(III) Halide Complexes with para-and meta-Substituted Benzeneseleninato Ligands

New complexes of osmium(III) with para - and meta-substituted benzeneseleninic acids of the type XC6H4SeO2H (X = H, p- Cl , m- Cl , p-Br, m-Br, p-Me) are reported. The compounds, of the type Os(XC6H4SeO2)3, Os(XC6H4SeO2)2Y, Os(XC6H4SeO2)Y2 and Os2(XC6H4SeO2)3Y3 (Y = Cl , Br), have been studied through spectroscopic techniques ( i.r ., far- i.r .and electronic spectra), magnetic susceptibility measurements, thermogravimetric studies and conductivity measurements. The wavelengths of the principal electronic absorption peaks have been accounted for quantitatively in terms of the crystal-field theory; the nephelauxetic parameter is indicative of an appreciable metal- ligand covalency. It is worth noting that among the present complexes the highest q values are related to the Os(XC6H4SeO2)3 derivatives in which OsO6 chromophores are present; the Dq values decrease on passing to the 1 : 2, 1 : 1.5 and 1 : 1 metal/ ligand molar ratio complexes according to the presence of chlorine- and bromine-containing chromophores . The i.r . data point to a seleninato -O,O′ coordination for all the complexes; in particular, the presence of three SeO bands with the irreducible representation A2 + 2E in the i.r . spectra of the tris derivatives suggests an octahedral configuration with D3 symmetry. All the halo complexes are polymeric octahedral with bridging halide atoms. The magnetic moment values lie in the expected range for the trisbenzeneseleninato derivatives, and they decrease on passing to the halo complexes.

Use of polymerase chain reaction and specific monoclonal antibodies as rapid method to recognize Borrelia burgdorferi sensu stricto, B. garinii and B. afzelii among Italian isolates of B. burgdorferi

We previously classified locally isolated strains of Borrelia burgdorferi by a restriction fragment length polymorphism analysis of total DNA, by DNA/DNA Southern Blot hybridization and by a hybridization with rRNA 16 + 23S from Escherichia coli [Cinco et al. (1993) Microbiologica 16:323-332] into three genetic groups which, according to the reference strains used, should correspond to the three species so far described as B. burgdorferi sensu stricto, B. garinii and B. afzelii. To find a simpler method for strain identification, in this study we analyzed the Italian strains and some strains identification, in this study we analyzed the Italian strains and some strains originating from other European countries, employing the species-specific 16S rRNA primers in the polymerase chain reaction technique (PCR) and some phenotypic markers like the B. afzelii-specific monoclonal antibodies and the battery of OspA-specific monoclonal antibodies which were reported to give a reactivity pattern correlated to the species [Wilske et al. (1993) J Clin Microbiol 31:340-350]. The PCR results confirmed those obtained previously by identifying the three groups as B. burgdorferi sensu stricto, B. garinii and B. afzelii; the reactivity patterns obtained with the monoclonal antibodies (mAb) also corresponded to those described as typical of the three species. We standardized the PCR technique to amplify a sample of crude template DNA obtained from a culture of 10(5) spirochetes.

DNA homology comparison between American and European Borrelia burgdorferi strains

Seven strains of Borrelia burgdorferi isolated from ticks and from human beings in Europe and U.S.A. were analyzed for DNA restriction patterns with several enzymes and for DNA homology in Southern blot hybridizations. The restriction patterns showed a moderately high variability. In Southern blot hybridization, strain B31 (U.S.A.) DNA gave a strong signal with itself, strain Bsf (U.S.A.) and Alcaide (isolated in Italy but presumably contracted in Venezuela). Strain B45 (F.R.G.) hybridized to itself, strain BITS (Italy) and to strain D.A. (Italy). Strain Nancy (Italy) gave a signal only when hybridized to itself, although it was classified as Borrelia on the basis of the clinical manifestations, SDS-PAGE protein pattern and antigenic determinants. No hybridization differences were observed for strains isolated from different hosts in the same continental geographical area.

A dot immunobinding assay to detect anti-alpha-gliadin antibodies in celiac disease

A dot immunobinding assay to detect anti-alpha-gliadin-specific antibodies in the sera or whole blood of enteropathic patients is described here. The method is based on the adsorption of alpha-gliadin as a spot onto nitrocellulose sheets. After incubation with the patient sample, the detection of specific antibodies is performed with alkaline phosphatase-conjugated goat anti-human (IgA or IgG) antibodies. Twenty-one celiac serum samples together with 18 enteropathic or disease controls and 44 healthy controls were analyzed. The classical ELISA test and the dot test gave comparable results. The dot test gave reliable result even when whole blood was tested. The method proved to be simple and sensitive.

Classification of Italian isolates of Borrelia burgdorferi into three genomic groups

In this study we investigated the genotypic characteristics of some locally isolated strains of B. burgdorferi by three different methodologies: restriction endonuclease analysis (REA), Southern blot hybridization with whole DNAs from Borrelia strains and Southern blot hybridization with rRNA 16 + 23S genes derived from E. coli. REA fingerprintings were evaluated by cluster analysis, according to the principles of numerical taxonomy. The genomas of the locally isolated strains were compared with borreliae originating from different countries of Europe, including Sweden and with the American reference strain B31. Among the European strains, some already described by Baranton (Baranton et al., 1992) as representatives of different genomic groups Borrelia sensu stricto and Borrelia garinii were used. By the different techniques the isolates were included in three genomic groups which could correspond to the three genospecies identified by Baranton, namely B. burgdorferi sensu stricto, B. garinii and B. group VS461: in fact two strains were included in a homogeneous group, probably corresponding to the VS461 genomic group, together with other European borreliae; one isolate was included in a group consisting of B31 and some other European strains already described as belonging to Borrelia burgdorferi in sensu stricto. Finally two isolates were ascribed to a third genomic group probably corresponding to the genospecies indicated as Borrelia garinii. These findings indicate that a small number of Borrelia strains isolated from a very restricted area can be genetically heterogeneous.

Morphological and molecular modifications induced by heat shock in Drosophila melanogaster embryos

The early embryo of Drosophila melanogaster did not survive treatment at 37 degrees C (heat shock) for 25 min. The histological analysis of eggs treated in this way showed that the heat shock caused disintegration of nuclei and of cytoplasmic islands, displacement and swelling of nuclei and blocked mitoses. These effects were not observed in embryos treated after blastoderm formation. After this stage, we noticed that development was slowed down. The heat shock proteins (hsp 83, 70 and 68) were, under shock, synthesized at all developmental stages. There was little or no synthesis of hsp 70 and 68 in unfertilized eggs, but synthesis increased in proportion to the number of nuclei present. Most probably, hsp 70 synthesis was directed by zygotic mRNA. DNA synthesis was not blocked by the heat shock though the overall incorporation of [3H]thymidine was substantially reduced, presumably because of the block of mitoses. We did not find a direct relation between survival pattern and hsp synthesis. We concluded that some, at least, of the heat shock genes can be activated at all developmental stages and that heat shock could be used for synchronizing mitoses.

Mixed chimerism in thalassemic patients after bone marrow transplantation

Seventy-four patients with homozygous beta-thalassemia who underwent allogeneic bone marrow transplantation (BMT) were analysed in order to evaluate the incidence and the significance of mixed chimerism (MC). Using a panel of four single locus specific minisatellite DNA probes, MC was found in 36.5%, 34.7% and 16.7% of the patients at 2, 6 and 12 months respectively after BMT. Moreover we found that different pretransplant conditioning regimens could be responsible for variations in the incidence of MC. The level of residual host cells found 2 months after BMT correlated with the occurrence of rejection.

[Elective cesarean section is preferred after the completion of a minimum of 38 weeks of pregnancy]

OBJECTIVE

To determine the frequency of neonatal respiratory morbidity following elective caesarean delivery at term and to identify prognostic factors for this morbidity.

DESIGN

Retrospective.

SETTING

Academic Hospital Utrecht/Wilhelmina Children's Hospital Neonatal Intensive Care Unit, Utrecht, the Netherlands.

METHOD

All elective caesarean deliveries in the Academic Hospital Utrecht from the period 1990-1995 were studied. Also, neonates were included who were admitted for intensive neonatal care because of respiratory insufficiency following elective caesarean delivery in the region surrounding Utrecht. An elective caesarean delivery was defined as a delivery performed after 37 weeks of gestation without any complicating factor that might influence the timing of delivery. Prognostic factors for neonatal morbidity after caesarean delivery were identified by multivariate logistic regression analysis.

RESULTS

During 1990-1995, 272 elective caesarean deliveries after 37 weeks of gestation were performed that fulfilled the inclusion criteria; 5.1% of the neonates were admitted to the medium care unit because of respiratory problems. The relative risk of respiratory morbidity after delivery by caesarean section with a gestational age of 39-42 weeks compared with a gestational age of 37-38 weeks, was 0.14 (95% confidence interval: 0.03-0.64; p < 0.001). Male sex was a cofactor. Nine neonates of whom 8 (90%) had a gestational age of less than 39 weeks were admitted to the intensive care unit.

CONCLUSION

Most of neonatal respiratory morbidity could have been avoided by postponement of the at-term elective caesarean section until a certain gestational age of at least 38 complete weeks. An elective caesarean section should not be performed before that period.