The Mitochondrial Disulfide Relay System Protein GFER Is Mutated in Autosomal-Recessive Myopathy with Cataract and Combined Respiratory-Chain Deficiency

A disulfide relay system (DRS) was recently identified in the yeast mitochondrial intermembrane space (IMS) that consists of two essential components: the sulfhydryl oxidase Erv1 and the redox-regulated import receptor Mia40. The DRS drives the import of cysteine-rich proteins into the IMS via an oxidative folding mechanism. Erv1p is reoxidized within this system, transferring its electrons to molecular oxygen through interactions with cytochrome c and cytochrome c oxidase (COX), thereby linking the DRS to the respiratory chain. The role of the human Erv1 ortholog, GFER, in the DRS has been poorly explored. Using homozygosity mapping, we discovered that a mutation in the GFER gene causes an infantile mitochondrial disorder. Three children born to healthy consanguineous parents presented with progressive myopathy and partial combined respiratory-chain deficiency, congenital cataract, sensorineural hearing loss, and developmental delay. The consequences of the mutation at the level of the patient''s muscle tissue and fibroblasts were 1) a reduction in complex I, II, and IV activity; 2) a lower cysteine-rich protein content; 3) abnormal ultrastructural morphology of the mitochondria, with enlargement of the IMS space; and 4) accelerated time-dependent accumulation of multiple mtDNA deletions. Moreover, the Saccharomyces cerevisiae erv1^R182H mutant strain reproduced the complex IV activity defect and exhibited genetic instability of the mtDNA and mitochondrial morphological defects. These findings shed light on the mechanisms of mitochondrial biogenesis, establish the role of GFER in the human DRS, and promote an understanding of the pathogenesis of a new mitochondrial disease.     

Transcriptomic response to differentiation induction

Background  

Microarrays used for gene expression studies yield large amounts of data. The processing of such data typically leads to lists of differentially-regulated genes. A common terminal data analysis step is to map pathways of potentially interrelated genes.     

Malaria prophylaxis policy for travellers from Europe to the Indian Sub Continent

Background

Thick blood films are routinely used to diagnose Plasmodium falciparum malaria. Here, they were used to diagnose volunteers exposed to experimental malaria challenge.

Methods

The frequency with which blood films were positive at given parasite densities measured by PCR were analysed. The poisson distribution was used to calculate the theoretical likelihood of diagnosis. Further in vitro studies used serial dilutions to prepare thick films from malaria cultures at known parasitaemia.

Results

Even in expert hands, thick blood films were considerably less sensitive than might have been expected from the parasite numbers measured by quantitative PCR. In vitro work showed that thick films prepared from malaria cultures at known parasitaemia consistently underestimated parasite densities.

Conclusion

It appears large numbers of parasites are lost during staining. This limits their sensitivity, and leads to erroneous estimates of parasite density.     

Mitochondrial DNA variant A4917G, smoking and spontaneous preterm birth

Spontaneous preterm birth (PTB; <37 weeks gestation) is a major risk factor for neonatal morbidity and mortality. The exact cause of PTB is unknown but oxidative stress may play an important role. Genetic studies have recently begun to elucidate the role of genetic variation in PTB but these studies have overlooked the mitochondrial genome/gene(s) as a plausible PTB candidate. In the present study, we sought to document association between nonsynonymous mitochondrial DNA (mtDNA) variants A4917G, G10398A and T4216C and PTB. We performed a case (PTB; <36 weeks gestation)-control (normal term) analysis of these mtDNA markers and examined their potential interaction with smoking in PTB. A sample of 422 pregnant Caucasian women (220 preterm and 202 terms) was examined for association. Haplogroup T marker A4917G was identified as a possible candidate for association with PTB after adjusting for smoking (OR=1.99 [95% CI 0.93-4.24]) as was T4216C (OR=1.63 [95% CI 0.93-2.83]). No significant multi-locus interactions or interactions with other environmental variables were observed. Our data, although preliminary, support the hypothesis that mitochondrial genome polymorphisms may play a significant role in PTB through an interaction with smoking.     

Characterization of the major allergen of plum as a lipid transfer protein

Background: Allergy to Prunoideae fruit (plum, peach, cherry and apricot) is one of the most frequent food allergies in southern Europe. All these fruits cross-react in vivo and in vitro, as they share their major allergen, a 9 kD lipid transfer protein (LTP). Objective: The aim of the study was the identification and molecular characterization of the major allergen of plum. Methods: The IgE pattern of reactivity to plums was investigated by SDS–PAGE and immunoblotting with the sera of 23 patients. The identified major allergen was purified by HPLC, using a cationic-exchange column followed by gel-filtration. Further characterization was achieved by periodic-Schiff stain, isoelectrofocusing and N-terminal amino acid sequencing. Results and conclusions: The major allergen of plum is a 9 kD lipid transfer protein, not glycosylated and with a basic character (pI>9), highly homologous to the major allergen of peach.     

Comparison of the conventional cervical smear and liquid-based cytology: results of a controlled, prospective study in the Abruzzo Region of Italy

OBJECTIVE: To compare conventional cervical testing (CCT) and liquid-based cytology (LBC) within a randomized trial performed during 2001-2002 in the Abruzzo Region of Italy, including a cost-outcome comparative analysis. STUDY DESIGN: Study subjects were recruited in the framework of a controlled, randomized study organized in the Abruzzo Region. Women aged 2 6-64 years were randomized to an active arm (LBC) or control arm (CC1). The particip ating laboratories had no previous ex perience with LBC. RESULTS: The inadequacy rate was 4.3% in CCT and 1.3% in the LBC arm (D < 0.001). Atypical squamous cells of undetermined sign ifi cance and atypical glands of undetermined significance reports were more frequent at CCT vs. LBC. A small, insignificant excess of low grade squamous intraepithelial lesions or high grade squamous epithelial lesions+ reports was observed in the LBC arm. The cervical intraepithelial neoplasia 2+ (CIN2+) detection rate was not statistically different in the 2 arms (CCT=0.54%, LBC= 0.66%, p = 0.28). In the overall series positive predictive value was slightly but not significantly higher in the LBC arm. LBC increased costs by 4.2% per both screened women and CIN2+ detected. CONCLUSION: The study reflects the introductory phase of LBC in laboratories without prior LBC experience. In this setting LBC reduced the inadequacy rate and decreased reading and was at least as sensitive as and more specific than CCT. Utilization of LBC in organized screening programs will be based on local feasibility, considering that the high cost of LBC is only partially compensated for by other benefits, such as residual cellular material, available for molecular testing, including human papillomavirus testing.     

Antimicrobial activity in methanolic extracts of several plant species from northern Argentina.

Thirty-nine native plant species were collected from the provinces of Chaco and Formosa, in northern Argentina, and were screened for antimicrobial activity. The plants were dried and extracted thoroughly with methanol. The dry extracts, dissolved in dimethylsulfoxide, were tested for inhibition of microbial growth via microplate assay with an oxidation-reduction dye. The test organisms were: Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Enterococcus faecium. Inhibition of respiratory activities in some of these microbial species was produced by the extracts of Astronium balansae, Geoffroea decorticans, Peltophorum dubium, Geoffroea spinosa, Lantana balansae, Prosopis kuntzei, Prosopis ruscifolia and Bulnesia sarmientoi, with minimal inhibitory concentrations (MIC) ranging from 0.08 to 0.5 mg dry matter/ml. Further in vitro experiments measuring the growth of S. aureus in liquid culture confirmed that all of the above extracts at 2 x MIC were able to inhibit bacterial growth effectively, and that some of them (A. balansae, G. decorticans, P. dubium, G. spinosa, P. kuntzei and B. sarmientoi) were able to reduce the initial number of viable counts by at least one order of magnitude in 10 hours, indicating that these extracts should be investigated further for the possible presence of bactericidal components.