Intraspecific phylogenetic analysis of Siberian woolly mammoths using complete mitochondrial genomes

We report five new complete mitochondrial DNA (mtDNA) genomes of Siberian woolly mammoth (Mammuthus primigenius), sequenced with up to 73-fold coverage from DNA extracted from hair shaft material. Three of the sequences present the first complete mtDNA genomes of mammoth clade II. Analysis of these and 13 recently published mtDNA genomes demonstrates the existence of two apparently sympatric mtDNA clades that exhibit high interclade divergence. The analytical power afforded by the analysis of the complete mtDNA genomes reveals a surprisingly ancient coalescence age of the two clades, approximately 1-2 million years, depending on the calibration technique. Furthermore, statistical analysis of the temporal distribution of the (14)C ages of these and previously identified members of the two mammoth clades suggests that clade II went extinct before clade I. Modeling of protein structures failed to indicate any important functional difference between genomes belonging to the two clades, suggesting that the loss of clade II more likely is due to genetic drift than a selective sweep.     

Maternal administration of granulocyte colony-stimulating factor improves neonatal rat survival after a lethal group B streptococcal infection

Maternally administered recombinant human granulocyte colony- stimulating factor (rhG-CSF) has been shown to cross the placenta and induce a peripheral neutrophilia and increases in the marrow and spleen neutrophil storage pools in fetal and newborn rats. In the present study, we have used this model system to investigate the efficacy of prenatally administered rhG-CSF on neonatal defense to a lethal challenge with Group B-beta hemolytic Streptococcus (GBS). Pregnant rats were injected with rhG-CSF twice daily beginning 6 days before parturition. At birth, all pups were infected with a dose of GBS that is lethal for 90% of infected pups (LD90). Survival was monitored daily for 5 days. Survival of infected pups from saline-treated mothers beyond 60 hours after infection was 10%. No difference in survival was observed among pups from mothers treated 2 and 4 days before parturition. In contrast, we determined that survival was 82.5% among infected pups from mothers treated for 6 days before parturition with rhG-CSF. Our results demonstrate that maternal administration of rhG- CSF augments neonatal defenses against a lethal bacterial challenge.     

Body composition and hormonal responses to a carbohydrate-restricted diet

The few studies that have examined body composition after a carbohydrate-restricted diet have reported enhanced fat loss and preservation of lean body mass in obese individuals. The role of hormones in mediating this response is unclear. We examined the effects of a 6-week carbohydrate-restricted diet on total and regional body composition and the relationships with fasting hormone concentrations. Twelve healthy normal-weight men switched from their habitual diet (48% carbohydrate) to a carbohydrate-restricted diet (8% carbohydrate) for 6 weeks and 8 men served as controls, consuming their normal diet. Subjects were encouraged to consume adequate dietary energy to maintain body mass during the intervention. Total and regional body composition and fasting blood samples were assessed at weeks 0, 3, and 6 of the experimental period. Fat mass was significantly (P 相似文献   

Treatment of achalasia: the short-term response to botulinum toxin injection seems to be independent of any kind of pretreatment

Background  

It has been suggested that intrasphincteric injection of botulinum toxin (BTX) may represent an alternative therapy to balloon dilatation in achalasia. The aim of the present study was to test the effectiveness of botulinum toxin injections in achalasia patients, as assessed using lower oesophageal sphincter pressure (LOSP) and symptom scores, and to compare the response in patients with different types of pretreatment (no previous treatment, balloon dilatation, myotomy, BTX injection).     

Management of common bile duct stricture caused by chronic pancreatitis with metal mesh self expandable stents.

Twenty patients with chronic pancreatitis and signs of biliary obstruction were treated by endoscopic placement of self expandable metal mesh stents, and followed up prospectively. Eleven had been treated previously with plastic endoprostheses. All had persistent cholestasis, seven patients had jaundice, and three overt cholangitis. Endoscopic stent placement was successful in all cases. No early clinical complication was seen and cholestasis, jaundice or cholangitis rapidly resolved in all patients. Mean follow up was 33 months (range 24 to 42) and consisted of clinical evaluation, ultrasonography, and endoscopic retrograde cholangiopancreatography (ERCP). In 18 patients, successive ERCPs and cholangioscopies have shown that the metal mesh initially embeds in the bile duct wall and is rapidly covered by a continuous tissue by three months. The stent lumen remained patent and functional throughout the follow up period except in two patients who developed epithelial hyperplasia within the stent resulting in recurrent biliary obstruction, three and six months after placement. They were treated endoscopically with standard plastic stents with one of these patients ultimately requiring surgical drainage. No patient free of clinical or radiological signs of epithelial hyperplasia after six months developed obstruction later. This new treatment could become an effective alternative to surgical biliary diversion if further controlled follow up studies confirm the initial impression that self expandable metal mesh stents offer a low morbidity alternative for longterm biliary drainage in chronic pancreatitis without the inconvenience associated with plastic stents.     

Establishment and characterization of an Epstein-Barr virus transformed cell line with strong phagocytic activity

An immunoglobulin M (IgM)-positive cell line, Ms 28, apparently spontaneously transformed by Epstein-Barr virus (EBV) was established from peripheral blood cells of a patient with immature myeloblastic leukemia. It has been characterized according to phenotype, cytochemistry, and membrane antigen pattern. The cell line expresses lymphoid markers like CD 19, CD 22, and CD 30 and synthesizes and secretes IgM. Monocyte markers CD 11c, CD 14, and CD 15 are absent. Neither interleukin-1 (IL-1), nor tumor necrosis factor (TNF-alpha) are produced. But Ms 28 cells show strong phagocytic activity and engulf Latex particles and sheep RBCs (SRBCs) that need not to be opsonized. The phagocytic activity can be inhibited by chloroquine. Both phagocytosis and EBV nuclear-antigen (EBNA) expression can be observed in one and the same cell. Ms 28 cells might be useful to study immunologic activities like antigen processing and presentation.     

Natural history of reflux oesophagitis: a 10 year follow up of its effect on patient symptomatology and quality of life.

BACKGROUND--Although oesophagitis is the most common diagnosis made at upper gastrointestinal endoscopy, data on the longterm outcome of affected patients are sparse. AIMS--This study assessed the level of reflux symptoms, quality of life, drug consumption, and complications in patients at least 10 years after diagnosis of oesophagitis at one centre. PATIENTS--One hundred and fifty two patients with typical reflux symptoms and a first time diagnosis by endoscopy of grade I-III oesophagitis between 1981 and 1984, were followed up using a postal questionnaire and telephone interview. RESULTS--Eighteen of 152 patients had died, 33 failed to respond, and 101 replied (mean follow up 11 years, range 121-160 months). Over 70% of patients still had heartburn at least daily (32%) or weekly (19%) or required daily acid suppression treatment (20%). Two patients (2%) had developed oesophageal strictures and one had Barrett's oesophagus. Two of eight quality of life scores (physical function and social function) measured by the Short Form-36 were significantly lower than Northern Ireland population scores. CONCLUSION--Nearly three quarters of patients previously diagnosed as having oesophagitis still had significant morbidity related to gastro-oesophageal reflux disease more than 10 years after diagnosis. Some quality of life scores were significantly lower than those of the general population.