[Hemophilia A: analysis of intron 18 and intron 7 of factor VIII gene and their role in a diagnostic strategy for carrier detection in a Chilean population]. / Hemofilia A: análisis del intron 18 e intron 7 del gen del factor VIII y su rol en una estrategia de diagnóstico de portadoras en una población chilena.

Hemophilia A is an X-linked disorder of coagulation caused by a deficiency of factor VIII. A larger number of different mutations in the VIII gene have been identified. Thus, the detection of female carriers, depends upon the analysis of DNA polymorphisms in and near the factor VIII gene. Our aim was to develop a strategy, earlier reported, for carrier testing in families at risk of hemophilia A. In this study, we analyzed the DNA polymorphisms in 26 affected families, with use of the factor VIII intragenic polymorphisms identified by the restriction enzymes BclI and AlwNI, and by differential hybridization with sequence-specific oligonucleotide probes recognizing BclI and AlwNI polymorphism. While the DNA polymorphism detected by BcilI site in intron 18 of the factor VIII gene was informative for 38% families studied, the AlwNI/intron 7 polymorphism provided additional information (4%). The carrier status of the remaining 58% could be determined utilizing the other polymorphisms suggested by strategy. The two polymorphic sites used combined with the other polymorphisms, intragenic and extragenic, can generate levels of informativeness greater than 98%. We concluded that the strategy for carrier testing would be a good alternative in genetic counselling for hemophilia A, but its limitations must be carefully taken into account.

[Hepatitis B and C virus infections in children with congenital coagulation disorders]. / Infección con los virus de la hepatitis B y C en niños con trastornos congénitos de la coagulación.

The prevalence of hepatitis B and C virus infections, transmitted by blood transfusions, was studied in 79 children with congenital coagulation disorders. Twenty nine percent had evidences of hepatitis B virus infection and 52% evidences of hepatitis C virus infection. Older children and those with the higher number of transfusions had the highest rates of infections. It is concluded that children with congenital coagulation disorders constitute a high risk group for hepatitis B and C virus infections.

[The effect of increased environmental temperature on the behavior of physiologic parameters in bicycle ergometry within the scope of the physical endurance limit]. / Einfluss erhöhter Umgebungstemperatur auf das Verhalten physiologischer Parameter bei Fahrradergometerarbeit im Bereich der physischen Dauerleistungsgrenze.

For determination of the endurance limit range, 8 healthy male probands aged between 20 and 26 years loads had carried out for one hour on a bicycle ergometer at an ambient temperature of +20 degrees C, +28 degrees C and +35 degrees C. Staying in an ambient temperature of 35 degrees C leads to a decrease in the physical endurance limit in an order of magnitude of 10 W. At 20 degrees C, in the endurance range the following values result (mean +/- s): load 68+/- 10.3 W, heart rate 113.6 +/- 5.8 beats per min., net heart rate 31.8 +/- 2.4 beats per min., oxygen uptake 1340 +/- 170 ml per min., auditory canal temperature 36.5 +/- 0.24 degrees C, sweat rate 275 +/- 143 g. At 35 degrees C, the endurance limit is attained at the following values: 57 +/- 10.6 W, heart rate 125 +/- 11.8 beats per min., net heart rate 27.4 +/- 3.6 beats per min., oxygen uptake 1210 +/- 130 ml per min., auditory canal temperature 37.2 +/- 0.3 degrees C, sweat rate 577 +/- 96 g.

Análisis de subpoblaciones de linfocitos en pacientes hemofílicos con anticuerpos a-VIH / Analysis of lymphocyte subpopulations in hemophilic patients with HIV-a antibodies

En el trabajo se analizan las subpoblaciones de LT inductores (LTi), LT supresores (LTs) con anticuerpos monoclonales anti-CD4 y anti-CD8 y el índice CD4/CD8 en 8 niños hemofílicos menores de 12 años que presentaban anticuerpos contra el virus de la inmunodeficiencia humana (VIH), 8 niños hemofílicos anti-VIH negativos y 15 adultos sanos anti-VIH negativos. Los resultados de LT CD4 en ambos grupos de hemofílicos fueron semejantes y mostraron una disminución significativa comparados con el grupo normal (p<0,022). Los LT CD8 estaban significativamente aumentados en el grupo de hemofílicos anti-VIH (-) y normales p<0,0044 y p<0,0003, respectivamente), no hubo diferencias entre los dos últimos grupos. El índice CD/CD8 estuvo disminuído en ambos grupos de hemofílicos comparados con el normal (p<0,0003). Este índice en el grupo de hemofílicos anti-VHI(+) fue significativamente menor que en los hemofílicos anti-VIH (-) (p0,465). Se discute el significado de estos resultados