Postglacial recolonization history of the European crabapple (Malus sylvestris Mill.), a wild contributor to the domesticated apple.

Understanding the way in which the climatic oscillations of the Quaternary Period have shaped the distribution and genetic structure of extant tree species provides insight into the processes driving species diversification, distribution and survival. Deciphering the genetic consequences of past climatic change is also critical for the conservation and sustainable management of forest and tree genetic resources, a timely endeavour as the Earth heads into a period of fast climate change. We used a combination of genetic data and ecological niche models to investigate the historical patterns of biogeographic range expansion of a wild fruit tree, the European crabapple (Malus sylvestris), a wild contributor to the domesticated apple. Both climatic predictions for the last glacial maximum and analyses of microsatellite variation indicated that M. sylvestris experienced range contraction and fragmentation. Bayesian clustering analyses revealed a clear pattern of genetic structure, with one genetic cluster spanning a large area in Western Europe and two other genetic clusters with a more limited distribution range in Eastern Europe, one around the Carpathian Mountains and the other restricted to the Balkan Peninsula. Approximate Bayesian computation appeared to be a powerful technique for inferring the history of these clusters, supporting a scenario of simultaneous differentiation of three separate glacial refugia. Admixture between these three populations was found in their suture zones. A weak isolation by distance pattern was detected within each population, indicating a high extent of historical gene flow for the European crabapple.

Host-specific differentiation among populations of Venturia inaequalis causing scab on apple, pyracantha and loquat.

Patterns of multilocus DNA sequence variation within and between closely related taxa can provide insights into the history of divergence. Here, we report on DNA polymorphism and divergence at six nuclear loci in globally distributed samples of the ascomycete Venturia inaequalis, responsible for scab on apple, loquat, and pyracantha. Isolates from different hosts were differentiated but did not form diagnosable distinct phylogenetic species. Parameters of an Isolation-with-Migration model estimated from the data suggested that the large amount of variation shared among groups more likely resulted from recent splitting than from extensive genetic exchanges. Inferred levels of gene flow among groups were low and more concentrated toward recent times, and we identified two potentially recent one-off shifters from apple and pyracantha to loquat. These findings support a scenario of recent divergence in allopatry followed by introgression through secondary contact, with groups from loquat and pyracantha being the most recently differentiated.

Construction of a contig of BAC clones spanning the region of the apple scab avirulence gene AvrVg.

The ascomycete Venturia inaequalis, causal pathogen of apple scab, underlies a gene-for-gene relationship with its host plant apple (Malus spp.). 'Golden Delicious', one of the most common cultivated apples in the world, carries the ephemeral resistance gene Vg. Avirulence gene AvrVg, matching resistance gene Vg has recently been mapped on the V. inaequalis genome. In this paper, we present the construction of a BAC library from a V. inaequalis AvrVg isolate. The library is composed of 7680 clones, with an average insert size of 80kb. By hybridization, it has been estimated that the library contains six haploid genome equivalents. Thus the V. inaequalis genome can be predicted to be approximately 100Mb in size. A chromosome walk, starting from the marker VirQ5 co-segregating with AvrVg, has been performed using the BAC library. Twelve BAC clones were identified during four steps of the chromosome walking. The size of the resulting contig is approximately 330kb.

Specific Polymerase Chain Reaction Identification of Venturia nashicola Using Internally Transcribed Spacer Region in the Ribosomal DNA.

ABSTRACT A technique based on the polymerase chain reaction (PCR) was developed for the identification of Venturia nashicola using nucleotide sequence information of the ribosomal DNA region. The complete internal transcribed spacer (ITS) region of V. nashicola strains and phylo-genetically related species was amplified with the two universal ITS1 and ITS4 primers, sequenced, and digested with five restriction enzymes. The alignment of nucleotide sequences and analyses of digestion patterns indicated constant polymorphisms between V. nashicola and related species at nucleotides 126 and 127, which overlapped a TaqI restriction site. An oligonucleotide primer named A126 was designed for identifying this variable region. A primer set (A126 and ITS4) that allowed the amplification of a 391-bp DNA fragment within the ITS region by PCR was specific to V. nashicola when it was checked against fungal genomic DNAs of related fungi. This primer set was a good candidate for a species-specific reagent in a procedure for identification of V. nashicola by PCR.

Intraoperative blood loss in pediatric liver transplantation: analysis of preoperative risk factors.

The relative contribution of 14 preoperative risk factors to a high intraoperative blood loss was studied in 95 consecutive first pediatric orthotopic liver transplantations (OLT). Patients were distributed in two groups according to red blood cell (RBC) requirements. Wide interindividual RBC requirements were observed (median, 79 mL/kg; range, 4-586). The upper quartile of the population was defined as the high blood loss group and required 123 mL/kg or more (median, 161). On univariate analysis, the high blood loss group had a significantly higher proportion of patients with portal vein hypoplasia, intraabdominal malformations, signs of severe liver failure (encephalopathy, ascites, prolonged prothrombin time), and requiring inpatient support. Age, previous abdominal surgery, and platelet count had no prognostic value. All variables used in the univariate analysis were included in a stepwise logistic regression analysis. Only presence of portal vein hypoplasia, inpatient support, and use of a reduced-size liver graft were independently associated with a high blood loss. Adjusted odds ratios were 40.4 (95% confidence interval; 5.9-278), 5.4 (1.6-17.9), and 3.8 (0.9-15.2), respectively, highlighting the importance of portal vein hypoplasia as a risk factor for high blood loss.

Measurement of irradiation doses secondary to bedside radiographs in a medical intensive care unit.

The authors prospectively studied the radiation doses to radio-sensitive organs secondary to bedside radiographs in intensive care patients and in a control phantom. Dosimeters were taped on different organs during each bedside X-ray. The mean radiation doses, expressed in 10(-5) Gy (m-rad), for an "average patient" who was hospitalized 9 days and had 6 chest X-rays were respectively: 292 to the sternal bone marrow; 239 to the thyroid gland; 3 to the testes; 1 to the ovaries; 605 to the eye for 2 maxillary sinus X-rays. No diffused irradiation was measured during a 2-month period in the intensive care unit nor on dosimeters worn by four nurses.

Neurologic complications in a group of 86 bacterial endocarditis.

Criteria defined by von Reyn were applied to 86 cases of bacterial endocarditis. Neurologic complications (NC) were categorized according to Pruitt definitions. Neurologic accidents were observed in 48 cases. They were the first clinical manifestation in 20 patients. Neurologic events were of poor prognosis in BE, mortality increasing from 26% in patients without NC to 83% in patients with NC (P less than 0.01). Two factors affect the incidence of NC: first, the location of endocarditis with 76% of NC in mitral valve endocarditis compared with 37% in other cases (P less than 0.005); and second the infecting organism: 71% of NC in staphylococcus aureus endocarditis versus 45% in endocarditis with other bacteria (P less than 0.02). Cerebral embolism was the most common NC (25 cases) related to an occlusion of the middle cerebral artery in 21 cases with a fatal outcome in 19 patients. Other NC included 15 intracranial hemorrhages with the evidence of an aneurysm in 4 cases, 6 septic meningitis, 2 macroscopic abscesses, and 2 multiple microscopic abscesses. This study emphasizes the high rate and severity of NC in staphylococcal mitral endocarditis despite antibiotic therapy and supports early surgery in this group of bacterial endocarditis.

Salmonella-infected subdural haematoma.

Post-traumatic chronic subdural haematoma infected by Salmonella sandiego is reported in a 55-year-old alcoholic man. Treatment involved a four-weeks' course of chloramphenicol and also subdural drainage. The patient ultimately recovered. Only four such cases have been reported in the literature. The mode of infection of the subdural haematoma is presumed to have been haematogenous in the absence of an otorhinological focus, meningitis or previous neurosurgery.

[Severe anaphylactoid complications in anesthesia. Apropos of 35 cases]. / Les accidents anaphylactoïdes graves en anesthésie. A propos de trente-cinq cas.

35 cases of severe anaphylactoid accidents during anesthesia are reported. Clinical symptomatology is dominated by cardiovascular collapse and/or bronchospasm and/or cutaneous and mucous manifestations. The course is always favourable. The usual risk factors (drug allergy, atopic background, spasmophilia, multiple anesthesia) are found. Pentothal alone or added to succinylcholine is most incriminated, followed by C-T 1341, curare-like agents, propanidid and macromolecular solutions. The immunoallergic investigation is incomplete, founded on the inhibition of leukocyte migration test TIML. The principal mechanisms responsible for these accidents and the most frequent causal products are recalled. Laboratory tests are reviewed. In conclusion, the authors propose a curative and preventive action to be taken when faced with this severe and non-exceptional accident of anesthesia.