The mitochondrial genome can be altered or lost without lethal effect in the petite-negative yeast Debaryomyces (Schwanniomyces) occidentalis

The nature of mutations affecting several cytochrome-deficient mutants of Debaryomyces (Schwanniomyces) occidentalis has been characterized. The DR12 mutant, which is deficient in cytochrome b, and the B10Mn mutant, which is deficient in cytochromes b and a, a3, are deleted in the mitochondrial CYB and COX1 genes respectively. The B10 strain, which is partially deficient in cytochrome b, has no detectable change in its mitochondrial DNA and possibly carries nuclear lesion(s). These three mutants, unlike the rho(-) and rho degrees "petite" mutants of Saccharomyces cerevisiae, can still grow on non-fermentable substrates, due to the development of a salicylhydroxamic acid (SHAM)-sensitive alternative pathway linked to phosphorylation at site 1. A gly(-) mutant lacking mtDNA and respiratory capacity has been isolated. For the first time, it is demonstrated that mtDNA can be altered or even lost without lethal consequence in D. occidentalis, although this yeast was classified as a petite-negative species.     

Resultados de la esofagectomía por cáncer tras la creación de un Comité de Tumores Esofagogástricos

Introduction

Treatment of oesophageal cancer with curative intent requires a multidisciplinary approach. Neoadjuvant therapy, the radicality of resection and extension of lymphadenectomy have been associated with increased operative morbidity and mortality. The aim of this study was to assess the results of surgical treatment of oesophageal cancer since the presence of an interdisciplinary esophagogastric tumour board.

Methods

Patients with cancer of the oesophagus and oesophagogastric junction who underwent oesophagectomy between January 2005 and March 2012 were included in this retrospective study. Data concerning type of resection, postoperative complications, mortality and survival were analysed.

Results

Of the 392 patients with a diagnosis of oesophageal cancer over the study period, 100 underwent oesophagectomy. Seventy-four patients received neoadjuvant treatment. Eighty-two patients underwent transthoracic resection while a transhiatal was used in 10 patients. Colon interposition was required in 8 cases. An R0 resection was achieved in 98 patients. Anastomotic leaks developed in 15 patients, 9 were intrathoracic and 6 were cervical. Postoperative morbidity occurred in 42% of patients, and intra-hospital and 90-day mortality was 2%. Median length of hospital stay was 16 days. The respective actuarial survival at 1 and 5 years were 82% and 56%.

Conclusions

Surgical treatment with curative intention for oesophageal cancer is only possible in a quarter of patients diagnosed. The high morbidity rate was mainly due to intrathoracic complications.     

Barriers to health-care and psychological distress among mothers living with HIV in Quebec (Canada)

Health-care providers play a major role in providing good quality care and in preventing psychological distress among mothers living with HIV (MLHIV). The objectives of this study are to explore the impact of health-care services and satisfaction with care providers on psychological distress in MLHIV. One hundred MLHIV were recruited from community and clinical settings in the province of Quebec (Canada). Prevalence estimation of clinical psychological distress and univariate and multivariable logistic regression models were performed to predict clinical psychological distress. Forty-five percent of the participants reported clinical psychological distress. In the multivariable regression, the following variables were significantly associated with psychological distress while controlling for sociodemographic variables: resilience, quality of communication with the care providers, resources, and HIV disclosure concerns. The multivariate results support the key role of personal, structural, and medical resources in understanding psychological distress among MLHIV. Interventions that can support the psychological health of MLHIV are discussed.     

Self-concept and Dating Violence in 220 Adolescent Girls in the Child Protective System

The aim of this study was to describe the dating violence experiences in a cohort of adolescent girls in the Child Protective System (CPS), and to assess how these experiences relate to their self-concept. A total of 220 adolescent Canadian girls under care of the CPS completed the Offer self-image questionnaire and the revised conflict tactic scales. Results showed that the majority of these girls have experienced some types of victimization in their dating relationships, the least prevalent form being severe injury (24.4%) and the most being minor psychological aggression (81.5%). Data provided here show that the self-concept of teenagers involved in severe violence that includes injury is especially negative. Girls who sustained severe violence with injuries reported more negative overall views of themselves, more problems regulating their emotional tone, more psychopathological symptoms, and lower vocational and educational goals. Implications for prevention initiatives and treatment interventions are discussed.     

Analyses bibliographiques

Sans résumé     

Supercharged ileocoloplasty: an option for complex oesophageal reconstructions

Introduction

Oesophageal reconstruction in a second time is a complex surgical operation which, in some cases, requires combining microvascular techniques to increase vascular flow to the conduit. «Supercharged» ileocoloplasty allows creation of a longer conduit that makes it possible to replace the entire oesophagus. We describe our initial experience with this technique for the total reconstruction of the oesophagus.

Material and methods

A retrospective review of the period from October 2007 to December 2009 identified 4 patients on whom a deferred oesophageal reconstruction was performed with a «supercharged» ileocoloplasty. The indications of this technique, morbidity and mortality, as well as functional results during follow up were evaluated.

Results

The indications of this technique were: previous failure of a left colon interposition (1), oesophageal disconnection due to a gastro-pleural fistula (1), total oesophagogastrectomy (1) and partial oesophagogastrectomy (1) due to the ingestion of caustic substances, respectively. Gastrointestinal complications were the most frequent. Two cervical fistulas were diagnosed which were resolved with an absolute diet, antibiotic therapy and enteral nutrition. There was no mortality. After a median follow up of 14.7 months, two patients were nourished exclusively by mouth, one by a mixed route (oral-enteral) and another exclusively by the enteral route due to an oesophageal stenosis 11 centimetres from the dental arch; this patient required dilations and is awaiting a jejunal graft.

Conclusions

«Supercharged» ileocoloplasty is a complex treatment option for the total reconstruction of the oesophagus when no other alternatives are available. Postoperative morbidity is significant but the functional results are good.     

Impact of Hydroxychloroquine-Loaded Polyurethane Intravaginal Rings on Lactobacilli

The use of polymeric devices for controlled sustained delivery of drugs is a promising approach for the prevention of HIV-1 infection. Unfortunately, certain microbicides, when topically applied vaginally, may be cytotoxic to vaginal epithelial cells and the protective microflora present within the female genital tract. In this study, we evaluated the impact of hydroxychloroquine (HCQ)-loaded, reservoir-type, polyurethane intravaginal rings (IVRs) on the growth of Lactobacillus crispatus and Lactobacillus jensenii and on the viability of vaginal and ectocervical epithelial cells. The IVRs were fabricated using hot-melt injection molding and were capable of providing controlled release of HCQ for 24 days, with mean daily release rates of 17.01 ± 3.6 μg/ml in sodium acetate buffer (pH 4) and 29.45 ± 4.84 μg/ml in MRS broth (pH 6.2). Drug-free IVRs and the released HCQ had no significant effects on bacterial growth or the viability of vaginal or ectocervical epithelial cells. Furthermore, there was no significant impact on the integrity of vaginal epithelial cell monolayers, in comparison with controls, as measured by transepithelial electrical resistance. Overall, this is the first study to evaluate the effects of HCQ-loaded IVRs on the growth of vaginal flora and the integrity of vaginal epithelial cell monolayers.