Fractionation and characterization of the immunosuppressive substance in crude extracellular products released by Streptococcus intermedius.

The noncytotoxic immunosuppressive substance detected in crude extracellular products of Streptococcus intermedius (CEP-SI) was fractionated by two steps of preparative isoelectric focusing in sucrose gradients using ampholytes of pH range from 3.5 to 6 and 4 to 5, respectively. The in vitro and in vivo suppressor effects of the most highly purified fraction of CEP-Si, designated fraction 3' (F3'EP-Si), corresponded well with those of the original CEP-Si. F3'EP-Si was sensitive to the effects of alpha, gamma, and delta chymotrypsin, trypsin, and heating. It contained approximately 1% of the total amount of protein found in the original CEP-Si, corresponding to a single band on analytical isoelectric focusing, stainable by Coomassie Blue and of isoelectric point of 4.25. The absorption spectrum of F3'EP-Si had a maximum at 260 nm but its biological activity was resistant to deoxyribonuclease and ribonuclease A and it did not contain material stainable by methylene blue. It was also resistant to neuraminidase and did not contain material stainable by periodic acid schiff. We conclude that the substance responsible for the suppressor activity of CEP-Si is a protein of molecular weight approximately 90,000, which adheres to Sephadex of cellulose acetate and forms complexes with other, nonactive constituents of CEP-Si.

Portuguese population and paternity investigation studies with a multiplex PCR--the AmpFlSTR Profiler Plus.

A Portuguese Caucasian population of 146 unrelated individuals was studied. DNA samples were amplified by multiplex PCR for D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820 using the AmpFlSTR Profiler Plus PCR Amplification Kit (Perkin-Elmer). All loci met Hardy-Weinberg expectations. Forensic statistical parameters were according to those obtained by other authors. Statistical differences were observed concerning three loci when comparing the Portuguese Caucasian population and an Italian Caucasian population, although these differences mainly concern the less frequent alleles. Eighty-three paternity investigation cases were analysed. Exclusions in between three and nine loci were observed in all the 23 exclusion cases obtained. Most of the non-exclusion cases had probability of paternity > 99.9%. Two cases with an isolated genetic incompatibility between the alleged father and the child were detected, which may indicate probable mutation cases. These results demonstrate that the AmpFlSTR Profiler Plus is a suitable multiplex for paternity investigation in the Portuguese population.

A STR mutation in a heteropaternal twin case.

A heteropaternal male twin case with two men being alleged fathers was investigated as requested by the Court. Up to 37 PCR-based polymorphic DNA systems were studied in this case which was complicated by a paternal ACTBP2 mutation detected in one twin. This is the first report on a STR mutation in a double paternity case where both biological fathers were indisputably identified. The STR systems enable the resolution of these complex genetic relationships even in a case where a mutation in one STR locus was encountered.

South Portuguese population data on the loci HLA-DQA1, LDLR, GYPA, HBGG, D7S8 and Gc.

Five South Portuguese Caucasian subpopulations were analyzed for the HLA-DQA1, LDLR, GYPA, HBGG, D7S8 and Gc loci. Genotype distributions for these loci did not deviate from Hardy-Weinberg expectations. The allele and genotype frequencies found have been compared with previously published data from North and Central Portugal. A total of 11 out of 138 chi-square comparisons of allele frequencies between different Portuguese populations showed a certain degree of divergence. Alentejo, Algarve, Madeira Island and Azores Islands populations might be considered as different groups in a database. For forensic casework, a composite South Portuguese Caucasian population database was obtained for estimating multiple locus profile frequencies using the six PCR-based loci studied.

Sequence variation of new alleles at the short tandem repeat D19S253 locus.

This paper reports the sequences of two new alleles identified in a population database study on the short tandem repeat D19S253 locus. A Portuguese Caucasian population and a Portuguese African population were studied. Forty-four selected alleles were sequenced and 11 different alleles were found. All the sequenced alleles shown to possess a simple tetranucleotide GATA repeat region structure. The two new alleles, alleles 6 and 16, follow the simple repeat pattern. During paternity investigation casework, 1028 meiosis were analyzed and five isolated genetic incompatibilities detected. In one case, a non-detectable allele with the used set of primers could be the explanation. In the other four cases, single-step mutations could be considered. The mutation rate obtained for this locus was 3.89 x 10(-3).

Alpha-1-antitrypsin and transferrin null alleles in the Portuguese population.

In a Portuguese family, a null allele was found in the Pi system. An apparent 'exclusion' of the mother was found to be due to the presence of null alleles in mother and child. A transferrin (Tf) null allele was found in a case of disputed paternity. The mother and putative father were heterozygous for Tf null alleles and the child was homozygous (TfQ0) and presented hypotransferrinemia.

Polymorphism of alpha1-antitrypsin in a Portuguese population.

Serum Pi phenotypes were studied in 219 samples. The MM phenotype was the most common as in all other populations. The frequencies of PiS and PiZ were high considering other populations. PiF was not detected.

Hyperamylasemia with an abnormal isoamylase distribution in patients with liver diseases.

Isoenzymes of amylase were studied in sera from 95 patients with various liver diseases and 82 controls. Twenty-two patients and two controls had hyperamylasemia. Four different zymograms were obtained by isoelectric focusing--normal, pancreatic, salivary/pancreatic, and double pancreatic. The prevalence of these zymograms was similar in controls and in patients with normal values of serum amylase, normal being the prevalent zymogram. Patients with hyperamylasemia had as predominant the salivary/pancreatic zymogram, corresponding to isoenzymes of similar isoelectric point common to both salivary and pancreatic secretions. The inhibitory assay revealed a predominant increase of pancreatic type isoamylase and showed a poor correlation with isoelectric focusing. Our findings indicate that hyperamylasemia occurs frequently in liver diseases and in most cases is associated with an abnormal electrophoretic pattern.

Alfa-one antitrypsin phenotypes and inhalatory pulmonary pathology.

One hundred and twenty nine workers in the cork industry, 69 rural workers, 66 carpet makers, 58 workers in a granite quarry and 51 workers in a rice husking factory were studied from an epidemiologic point of view. All were submitted to a standard questionnaire planned to detect respiratory disease due to inhalatory causes. They were submitted to a clinical examination, summary ventilatory function tests, a 70 mm microradiograph, and blood was taken to determine alfa-one antitrypsin and its phenotypes and, in the cork industry workers and rice husking workers, the level of IgA, IgG and IgM. The results are presented and an attempt is made to correlate the various parameters among themselves, and namely alfa-one AT phenotypes with the existence of respiratory pathology. Finally the results are discussed.

A review of the collaborative exercises on DNA typing of the Spanish and Portuguese ISFH Working Group. International Society for Forensic Haemogenetics.

Since 1992 the Spanish and Portuguese Working Group (GEP) of the International Society for Forensic Haemogenetics (ISFH) has been organizing collaborative exercises on DNA profiling with the aim of making progress on standardization and discussing technical and statistical problems in DNA analysis. A total of four exercises (GEP-92 to GEP-95) have been carried out until now. A consequence of these exercises was the creation of a quality control programme in Spain and Portugal in 1995 which was carried out simultaneously with the GEP-95 exercise. The number of participating laboratories increased from 10 in the first exercise (GEP-92) to 19 in the last exercise (GEP-95). Despite this increasing number of participating laboratories, results remained satisfactory. In the last exercises, all the laboratories used PCR-based DNA polymorphisms with an increasing number of markers obtaining good results. SLPs were used by only 30% of laboratories in the last two exercises but the results indicated a good level of expertise in most of these laboratories. The reasons for these successful results are the common use of the EDNAP protocol for SLP analysis and commercially available kits or common sequenced allelic ladders for PCR-based DNA polymorphisms.