Late symptomatic initiation of unilateral cerebellar hypoplasia

A 65-year-old woman developed a progressive action tremor on her left hand for the last two years. On examination an intentional left hand tremor with dysmetria and tendency to deviate to left on tandem were identified. There was no mental deterioration. CT scan and MR imaging disclosed a marked unilateral, left, cerebellar hypoplasia. MR also showed multiple lacunae. Neurological family disease and exposition to drugs or alcohol were not present. In some cases cerebellar hypoplasia could become symptomatic at advanced age as result of concurrent cerebral disease affecting the compensating structures for congenital defect. In this patient a vascular mechanism is suggested as possible late trigger.     

Functional significance of a natural allelic variant of human carbonyl reductase 3 (CBR3).

Human carbonyl reductase (CBR) activity accounts for a significant fraction of the metabolism of endogenous and xenobiotic carbonyl compounds. It is possible that genetic polymorphisms in CBR1 and CBR3 are key for the wide interindividual variability in the disposition of CBR drug substrates. We pinpointed a single nucleotide polymorphism in CBR3 (CBR3 V244M) that encodes for a V244 to M244 change. Blacks showed a higher frequency of the M244 allele (q = 0.51, n = 49) than did whites (q = 0.31, n = 70; p = 0.003). In addition, DNA variation panels from 10 ethnic groups presented a wide range of CBR3 V244M genotype distributions. Kinetic experiments with the recombinant CBR3 protein variants and menadione revealed that CBR3 M244 has significantly higher V(max) than does CBR3 V244 (V(max) CBR3 M244 = 40.6 +/- 1.3 micromol/min x mg versus V(max) CBR3 V244 = 19.6 +/- 2.0 micromol/min x mg, p = 0.002). In contrast, both isoforms presented similar K(m) values (K(m) CBR3 M244 = 22.9 +/- 2.9 microM versus K(m) CBR3 V244 = 24.6 +/- 3.2 microM, p = 0.43). Assays with NADP(H) demonstrated a higher V(maxNADP(H)) (1.6-fold) and increased catalytic efficiency (V(maxNADP(H))/K(mNADP(H))) for CBR3 M244 compared with CBR3 V244 (p = 0.013). Comparative three-dimensional analyses based on the structure of the homologous porcine carbonyl reductase suggested that the V244M substitution is positioned in a region critical for interactions with the NADP(H) cofactor. These studies demonstrate that the common CBR3 V244M polymorphism encodes for CBR3 isoforms with distinctive enzymatic properties.     

Forensic identification of skeletal remains from members of Ernesto Che Guevara’s guerrillas in Bolivia based on DNA typing

We report the positive identification of several members of the guerrillas led by Ernesto “Che” Guevara on the 1960 s in Bolivia by means of DNA fingerprinting. Successful DNA typing of both short tandem repeat loci and the hypervariable region of the human mitochondrial DNA was achieved after extracting total DNA from bones obtained from two burial sites. Given the size of the Cuban database for the STR allele frequencies, a conservative approach was followed to estimate the statistical significance of the genetic evidence. The estimated probabilities of paternity for the two cases in which the paternity logic was applied were higher than 99%. One case was analyzed using mitochondrial DNA and could not be excluded from the identity proposed by the forensic anthropology team. A fourth case was identified by exclusion, on the basis of the positive identification of the other remains, the historical and other anthropological evidence. Received: 19 January 1999 / Received in revised form: 15 April 1999     

A case of myopericarditis associated to Campylobacter jejuni infection in the Southern Hemisphere

Myopericarditis is an infrequent complication of acute diarrheal illness due to Campylobacter jejuni, and it has been mainly reported in developed nations. The first case detected in Chile – an upper-middle income country –, that is coincidental with the increasing importance of acute gastroenteritis associated to this pathogen, is described. Recognition of this agent in stools requires special laboratory techniques not widely available, and it was suspected when a young patient presented with acute diarrhea, fever, and chest pain combined with electrocardiogram (EKG) abnormalities and elevated myocardial enzymes. C. jejuni myopericarditis can easily be suspected but its detection requires dedicated laboratory techniques.