Frequency of the hypervariable DNA loci D18S849, D3S1744, D12S1090 and D1S80 in a mixed ancestry population of Chilean blood donors

Blood donors (N = 150) at San José Hospital (Santiago, Chile) were typed for one VNTR locus (D1S80) and three STR loci (D18S849, D3S1744, D12S1090). A questionnaire was used to determine the socioeconomic level of the donors, because it is known that some genetic markers (e.g., the ABO and Rh groups) are differentially distributed between different socioeconomic strata. This methodology revealed that two of the three socioeconomic strata distinguishable in Santiago were present in our sample of blood donors, with stratum II representing the middle strata and stratum III the low strata. Allele frequency was determined for each locus and socioeconomic stratum, and it was found that the allele distributions of each locus in socioeconomic strata II and III were statistically similar. All loci conformed to the Hardy-Weinberg law and there was no evidence for association between the alleles of the four loci, allelic frequencies being similar to those found in North American Hispanic populations. The results support the view that the analysis of these loci may have useful applications in population genetics as well as in identity tests

[Fiber-optic intubation with non-invasive ventilation with an endoscopic facial mask]. / Intubation fibroscopique sous ventilation non invasive avec un masque facial endoscopique.

OBJECTIVES: To assess the feasibility and safety of a new technique of fiberoptic bronchoscopy (FOB) tracheal intubation (TI) with noninvasive ventilation (NIV) via an endoscopic full facial mask with two openings, in case of acute respiratory failure (ARF) temporally improved by NIV, but requiring a mechanical ventilation. STUDY DESIGN: Clinical, prospective, open, noncomparative trial of feasibility with direct individual profit. PATIENTS: Sixteen patients with ARF (age: 60 +/- 17 years, PaO2 = 59 +/- 16 mmHg, PaCO2 = 64 +/- 26 mmHg, PaO2/FIO2 = 142 +/- 70 before NIV) (m +/- SD), requiring TI. Including were: TI necessity (SpO2 < 90% or hypercapnic despite NIV, dependence of NIV, exhaustion, septic syndrome), clinical and SpO2 improvement with NIV. METHODS: After i.v. injection of 5 mg midazolam and topical anesthesia (TA) of the nose, the endoscopic mask (modified Fibroxy, Péters) was applied to the face, fixed with elastic straps, then connected to the ventilatory support system with IPAP = 20 cmH2O, EPAP = 5 to 12 cmH2O, FIO2 = 1. A tube was slid on the FOB. As soon as SpO2[[[nbsp] 94%, the extremity of the FOB, was inserted through the lower opening of the mask, slid in the nostril, positioned in front of the glottis for AL, then pushed in the trachea authorizing AL and i.v. injection of 0.15 mg.kg-1 of etomidate (Ramsay[[[nbsp]3). The tube was then slid in the trachea, then, FOB was removed from trachea. RESULTS: The FOB intubation was easy at the patient's, without any failure or any complication. The procedure was 6.7 +/- 2 min. SpO2 significantly improved during TI, from 84 +/- 5% (FIO2 = 0.6 +/- 3) to 97 +/- 1 (FIO2 = 1 +/- 0), without decrease in oxygen saturation off 90%. Arterial pressure decreased only after the 5th min. The quantities of midazolam and of etomidate used were 4.6 +/- 2 mg and 12 +/- 4 mg. Three patients benefited from EPAP > 10 cmH2O. CONCLUSION: Fiberoptic tracheal intubation with NIV via an adapted endoscopic facial mask is a safe technique in patient with ARF temporally improved by NIV. This procedure requires TA and conscious sedation.

Frequency of the hypervariable DNA loci D18S849, D3S1744, D12S1090 and D1S80 in a mixed ancestry population of Chilean blood donors.

Blood donors (N = 150) at San José Hospital (Santiago, Chile) were typed for one VNTR locus (D1S80) and three STR loci (D18S849, D3S1744, D12S1090). A questionnaire was used to determine the socioeconomic level of the donors, because it is known that some genetic markers (e.g., the ABO and Rh groups) are differentially distributed between different socioeconomic strata. This methodology revealed that two of the three socioeconomic strata distinguishable in Santiago were present in our sample of blood donors, with stratum II representing the middle strata and stratum III the low strata. Allele frequency was determined for each locus and socioeconomic stratum, and it was found that the allele distributions of each locus in socioeconomic strata II and III were statistically similar. All loci conformed to the Hardy-Weinberg law and there was no evidence for association between the alleles of the four loci, allelic frequencies being similar to those found in North American Hispanic populations. The results support the view that the analysis of these loci may have useful applications in population genetics as well as in identity tests.

[Association between maternal heterozygosity for five blood groups and reproductive success]. / Asociación entre heterocigocidad materna para cinco grupos sanguíneos y éxito reproductivo.

BACKGROUND: In man, blood groups are polymorphic genetic systems. Maternal fetal incompatibility phenomena should lead to an elimination rather than a maintenance of these polymorphisms. A possible mechanism that could explain the persistence of these polymorphisms in natural populations is a selective reproductive advantage of heterozygous individuals. AIM: To explore the relationship between maternal heterozygosity for five blood groups and some obstetrical variables related to gestational success. MATERIAL AND METHODS: Using a case control design, to every mother giving birth to a malformed child a consecutive mother, whose offspring was normal, was assigned as control. All women were typified for ABO, Rh, Kidd, MNSs and Duffy blood groups. RESULTS: Two hundred two women were studied. There was only one stillbirth, born from a heterozygous mother for all analyzed loci. Mothers that were heterozygous or homozygous for all loci had a higher frequency of malformed children. Women homozygous for all loci had a higher frequency of living offspring than the rest of the sample. CONCLUSIONS: Heterozygous mothers for these genetic systems have a reproductive disadvantage.

[Association between Kidd blood group and congenital malformations]. / Asociación entre grupo sanguíneo kidd y malformaciones congénitas.

BACKGROUND: Since the discovery of blood groups, an association between these genetic polymorphisms and pathological phenotypes has been searched, looking for factors involved in the pathogenesis of diseases or biological population mechanisms that maintain these polymorphisms. In previous reports, we have described some associations between erythrocytic genetic marker segregation and the presence of congenital malformations. AIM: To explore the association between Kidd blood group and congenital malformations. PATIENTS AND METHODS: One hundred twenty two malformed newborns and their mothers and 136 normal newborns, seen at the Clinical Hospital of the University of Chile, were studied. RESULTS: Kidd blood group segregation distortions were found among male malformed newborns, that were not present in normal newborns. Among mothers of both groups of newborns, a paucity of heterozygous for this system was found. CONCLUSIONS: The association found between a blood group and congenital malformations, allows to state that malformed children have a different genetic background, when compared to normal children.

[Paternity study applying DNA polymorphism: evaluation of methods traditionally used in Chile]. / Estudio de paternidad aplicando el polimorfismo de DNA: Evaluación en relación a los métodos convencionalmente usados en Chile.

Simultaneous detection of several VNTR loci using a single DNA probe is the basis of the technique called "DNA fingerprint" (DNAfp) of increasing application in parenthood identification. According to the data gathered by different laboratories worldwide, father exclusion can be made in a larger number of cases when compared with the customary tests based on erythrocyte antigens. The question could then be whether DNAfp will completely replace erythrocyte antigens tests. We report here our experience in applying DNAfp to 92 samples corresponding to 34 paternity cases and comparing these with the results obtained with the antigens of the systems ABO, Rh, MNSs, Duffy and Kidd. Most of the HaeIII/digested DNA samples produced 13 to 16 bands larger than 4.3 Kb (average 14,0761 +/- 2,205). Average band sharing between pairs of unrelated individual was 1,9107 +/- 1,083. Two cases presenting an a posteriori probability of being the father of 80.7% and 76.5% by erythrocyte antigens were clearly excluded by DNAfp. All exclusions made by antigens were confirmed by DNAfp. In the cases reported as father "rather probable" (28 cases) by DNAfp, these shared with the child 6,7407 +/- 1.7 bands on average. Because of time, cost and simplicity we favor a procedure starting with the antigens test and continuing with DNAfp only when an exclusion is not possible. Economy will increase as the number of exclusions increases.

[Duffy blood group in malformed newborns and their mothers]. / Grupo sanguíneo Duffy en recién nacidos malformados y sus madres.

The aim of this work is to analyze the distribution of Duffy blood group and the reproductive history of 148 malformed newborns and their mothers compared to 131 control pairs. The mother-child segregation of the system is analyzed using ITO matrixes. A higher frequency of heterozygote mothers for the system was found among the malformed group compared to controls. No differences in the reproductive history was found between Duffy system homozygote or heterozygote mothers.

[MNSs system mother-newborn segregation distortions]. / Distorsiones segregacionales madre-hijo del sistema MNSs.

We present segregation distortions for the MNSs system and for the sex ratio found among 400 mother-newborn pairs, from the northern Area of Santiago and the middle-low and low socioeconomic strata. Three subsamples were taken: from the non private patients of the Clinical Hospital of the University of Chile; from the Hospital San José, a public hospital of this Area; controls of malformed newborns belonging to an international study from the Clinical Hospital of the University of Chile. In spite of the almost homogeneity of socioeconomic strata and area, the differences among these subsamples did not allow us to take them as only one sample. We found excess of heterozygous individuals for the MN locus, specially among mothers. Ss heterozygotes had a higher sex ratio than ss homozygotes. Several distortions could not be dealt with as having a regular pattern in the three subsamples. A possible technical error is discussed.

[MN blood group and congenital malformations]. / Grupo sanguíneo MN y malformaciones congénitas.

This work analyzes the mother-son segregation of MN blood group in malformed and normal newborns. MN blood group was measured in 90 malformed, 70 paired normal newborns and their respective mothers, at the Maternity of the University of Chile Clinical Hospital. The expected values for the different mother-child pairs were calculated according to the ITO matrix method, using maximally probable appraisers. Among malformed newborns, there was an excess of heterozygous sons when the mother was homozygous for the MN system. Among malformed males, there was an excess of MM-MN and MN-MM mother-son pairs. Among control newborns, no distortions were found. These results suggest that there is a strong association between MN heterozygosis, sex and congenital malformations.

[Paternity study in Chilean families using DNA fingerprints and erythrocyte blood markers]. / Estudio de paternidad en familias Chilenas por impresión dactilar de ADN y marcadores sanguíneos eritrocitarios.

In the last decade, the electromorphic phenotype corresponding to extremely polymorphic zones of DNA, that include variable number of tandem repeat loci (VNTR) of oligonucleotide sequences, have been added to classical markers to elucidate the problems of parenthood identification and ascription in human beings. Using VNTR of several loci, a band profile practically unique for each individual is obtained (DNA-fingerprints). Since the pattern of VNTR electrophoretic bands is inherited from parents in a proportion of 50% from each one, this system is extremely useful for paternity ascription or exclusion. Nine nuclear families were studied, randomly selected from a group of 170 families that were analyzed using 5 erythrocyte genetic markers and with VNTRs detected using the multi locus probe (CAC)5, aiming to explore the concordance of both methods. Results were similar for both methods; however for VNTR, there is no information available on population frequency of polymorphisms.