XPC branch-point sequence mutations disrupt U2 snRNP binding, resulting in abnormal pre-mRNA splicing in xeroderma pigmentosum patients.

Mutations in two branch-point sequences (BPS) in intron 3 of the XPC DNA repair gene affect pre-mRNA splicing in association with xeroderma pigmentosum (XP) with many skin cancers (XP101TMA) or no skin cancer (XP72TMA), respectively. To investigate the mechanism of these abnormalities we now report that transfection of minigenes with these mutations revealed abnormal XPC pre-mRNA splicing that mimicked pre-mRNA splicing in the patients' cells. DNA oligonucleotide-directed RNase H digestion demonstrated that mutations in these BPS disrupt U2 snRNP-BPS interaction.

Xeroderma pigmentosum-variant patients from America, Europe, and Asia.

Xeroderma pigmentosum-variant (XP-V) patients have sun sensitivity and increased skin cancer risk. Their cells have normal nucleotide excision repair, but have defects in the POLH gene encoding an error-prone polymerase, DNA polymerase eta (pol eta). To survey the molecular basis of XP-V worldwide, we measured pol eta protein in skin fibroblasts from putative XP-V patients (aged 8-66 years) from 10 families in North America, Turkey, Israel, Germany, and Korea.

Relationship among placental cadmium, lead, zinc, and copper levels in smoking pregnant women.

Previous studies on Cd-exposed pregnant animals have reported a Cd-Zn interaction that result in increased placental Cd levels and decreased placental Zn transport. In this study, placental Cd, Pb, Cu, and Zn status in pregnant women exposed to Cd and Pb through cigarette smoke was investigated. Placental tissues obtained from 30 nonsmokers (controls), 70 passive smokers, and 90 smokers were analyzed for Cu and Zn levels using an atomic absorption spectrophotometer and for Pb and Cd levels using an EG&G PARC Model 303A hanging mercury drop electrode.

Reduced XPC DNA repair gene mRNA levels in clinically normal parents of xeroderma pigmentosum patients.

Xeroderma pigmentosum group C (XP-C) is a rare autosomal recessive disorder. Patients with two mutant alleles of the XPC DNA repair gene have sun sensitivity and a 1000-fold increase in skin cancers. Clinically normal parents of XP-C patients have one mutant allele and one normal allele.

Plasma D-lactic acid level: a useful marker to distinguish perforated from acute simple appendicitis.

Early diagnosis of perforated appendicitis is important for reducing morbidity rates. The aim of this study was to determine the value and utility of plasma D-lactic acid levels in identifying the type of appendicitis. In this clinical study, plasma D-lactic acid levels were assessed in 44 consecutive paediatric patients (23 with acute appendicitis, 21 with perforated appendicitis) before laparotomy.

Maternal and fetal plasma adenosine deaminase, xanthine oxidase and malondialdehyde levels in pre-eclampsia.

The aim of this study was to evaluate maternal-fetal plasma adenosine deaminase, xanthine oxidase (ADA, XO) activity and malondialdehyde (MDA) levels and the relationship between them in pre-eclampsia. Maternal and umbilical cord whole blood samples were taken from 29 pre-eclamptic and 33 normal pregnants. The plasma ADA, XO activities as well as MDA levels were assayed by spectrophotometric methods.

[Comparison of the antioxidant enzyme levels with the degree of dysfunction in patients with myocardial dysfunction].

Objective: Myocardial dysfunction in patients with cardiomyopathy is proposed to occur due to membrane changes caused by oxidative stress. In our study we evaluate whether there is any relation between the degree of myocardial dysfunction and antioxidant enzymes.

Methods: We studied superoxide dismutase (SOD), glutathione peroxidase (GSHPx) and catalase (CAT) enzyme activities from blood samples of 60 patients (30 patients had ejection fraction (EF) < %35 and 30 patients had EF= %35-50) who have myocardial dysfunction according to clinical findings and two-dimensional echocardiography, and 20 healthy volunteers.

Two essential splice lariat branchpoint sequences in one intron in a xeroderma pigmentosum DNA repair gene: mutations result in reduced XPC mRNA levels that correlate with cancer risk.

The lariat branch point sequence (BPS) is crucial for splicing of human nuclear pre-mRNA yet BPS mutations have infrequently been reported to cause human disease. Using an inverse RT-PCR technique we mapped two BPS to the adenosine residues at positions -4 and -24 in intron 3 of the human XPC DNA repair gene. We identified homozygous mutations in each of these BPS in two newly diagnosed Turkish families with the autosomal recessive disorder xeroderma pigmentosum (XP).

Effects of caffeic acid phenethyl ester and alpha-tocopherol on reperfusion injury in rat brain.

Oxygen-derived free radicals have been implicated in the pathogenesis of cerebral injury after ischaemia-reperfusion. Caffeic acid phenethyl ester (CAPE), an active component of propolis extract, exhibits antioxidant properties. The purpose of the present study was to investigate the effects of ischaemia and subsequent reperfusion on rat brain and to investigate the effects of two free radical scavengers, CAPE and alpha-tocopherol, on this in vivo model of cerebral injury.