Association of high-altitude pulmonary edema with the major histocompatibility complex

BACKGROUND: A constitutional susceptibility has been suggested in the development of high-altitude pulmonary edema (HAPE) because HAPE generally affects healthy young people, some of whom suffer recurrent episodes. We examined whether immunogenetic susceptibility is present in HAPE-susceptible subjects. METHODS AND RESULTS: The frequencies of human leukocyte antigen (HLA) alleles in 28 male and 2 female subjects with a history of HAPE were compared with those in 100 healthy volunteers. We assayed the HLA-A, -B, -C, -DR, and -DQ antigens serologically. The pulmonary hemodynamics on admission to the hospital and the ventilatory response to hypoxia and hypercapnia were retrospectively examined in 10 of the HAPE-susceptible subjects. HLA-DR6 was positive in 14 (46.7%) of the subjects with HAPE but only 16.0% of the control subjects (P=.0005), and HLA-DQ4 was positive in 12 (40.0%) of the subjects with HAPE but only 10.0% of the control subjects (P=.0001). HLA-DR6 or HLA-DQ4 was positive in 8 (100%) of the subjects with recurrent HAPE. The pulmonary arterial pressure on admission of the HLA-DR6-positive subjects with HAPE was significantly higher than that of the HLA-DR6-negative subjects with HAPE. CONCLUSIONS: There were significant associations of HAPE with HLA-DR6 and HLA-DQ4 and of pulmonary hypertension with HLA-DR6. An immunogenetic susceptibility, which is associated with HLA class II alleles located within the major histocompatibility complex, may underlie the development of HAPE, at least in some of its forms.     

Endoscopic ligation for non-esophageal variceal upper gastrointestinal hemorrhage

Mortality from radical cystectomy is still high, in some series accounting for 1-10% deaths. Morbidity is even higher and can reach 50%. This paper contributes the case of a 66-year old male patient diagnosed with an infiltrant tumour of the bladder following TUR. The patient's background included prior surgery for gastroduodenal ulcus, alcohol consumption, and obesity. Following routine pre-operatory investigations, the patient underwent radical cystectomy using routine techniques and urinary by-pass via transcolonic ureterosigmoidostomy. Increased transaminases, leucocytosis, vomiting, jaundice and extended intestinal ileum were noted during the patient's post-operative period, while blood and urine amylase concentrations were moderately high. Following CAT study, laparotomy was performed and the diagnosed confirmed. The patient died on day 14 of surgery due to secondary pulmonary complications. Post-operative pancreatitis is a low-frequency, high-mortality acknowledged complication. Even though most cases are secondary to biliarypancreatic and surrounding pancreas area surgery, it has also been described in some instances of distant surgery such as the present case. Alcohol consumption, biliary lithiasis, prior cholecystectomy and diabetes are predisposing factors. High amylase values do not always accompany this condition. Early diagnosis and treatment are crucial for the patient's prognosis. Respiratory complications are the usual cause of death in these patients.     

Effect of vinylene carbonate as additive to electrolyte for lithium metal anode

The cycling efficiencies and cycling performance of a lithium metal anode in a vinylene carbonate (VC)-containing electrolyte were evaluated using Li/Ni and LiCoO₂/Li coin type cells. The cycling efficiencies of deposited lithium on a nickel substrate in an EC + DMC (1:1) electrolyte containing LiPF₆, LiBF₄, LiN(SO₂CF₃)₂ (LiTFSI), or LiN(SO₂C₂F₅) (LiBETI) at 25 and 50 °C were improved by presence of VC. However, the lithium cycling efficiencies at low temperature (0 °C) decreased by adding VC to the EC+DMC (1:1) electrolyte. The deposited lithium at low temperature exhibited a dendritic morphology and a thicker surface film. The lithium ion conductivity of the VC derived surface film was lower than that of the VC-free surface film at low temperature. Therefore, we concluded that the cycling efficiency decreased with decreasing temperature. On the other hand, the cell containing VC additive has excellent performance at elevated temperature. The deposited lithium at 50 °C in the VC-containing electrolyte exhibited a particulate morphology and formed a thinner surface film. The VC derived surface film, which consists of polymeric species, suppressed the deleterious reaction between the deposited lithium and the electrolyte.     

Amplitude-dependent internal friction in copper thin films on silicon substrates

Internal friction in copper thin films 0.2–1.5 μm thick on silicon substrates has been measured between 180 and 340 K as a function of strain amplitude. Analysis of the amplitude-dependent internal friction in the copper films shows the relation between the plastic strain of the order of 10⁻⁹ and the effective stress on dislocation motion. The stress–strain curves thus obtained for the copper films tend to shift to a higher stress with decreasing film thickness and also with decreasing temperature, both indicating a suppression of microplastic flow. It is concluded that the microflow stress at a constant level of the plastic strain varies inversely with the film thickness at all temperatures examined. The film thickness effect in the microplastic range can be explained on the basis of a dislocation-bowing model.     

Carrier Generation in Wide-Gap Conductor, Zinc Antimonate

Mechanisms for carrier generation in zinc antimonate (ZnSb₂O₆) with a wide band gap were examined in relation to its crystallinity. ZnSb₂O₆ prepared by the reaction of Sb₂O₅ sol and 3ZnCO₃·4Zn(OH)₂ was sintered at 893, 1173, and 1393 K, and characterized by X-ray diffraction (XRD), electrical conductivity and diffuse reflectance measurements. A higher conductivity was found for ZnSb₂O₆ sintered at lower temperatures. Rietveld analysis of XRD patterns showed that the cations in conductive ZnSb₂O₆ occupied irregular sites, similar to the random rutile structure. Electron carriers were also considered to be generated by oxygen vacancies in ZnSb₂O₆ samples which have a structure similar to the random rutile structure.     

Gene rearrangements in snake mitochondrial genomes: highly concerted evolution of control-region-like sequences duplicated and inserted into a tRNA gene cluster

Mitochondrial DNA (mtDNA) regions corresponding to two major tRNA gene clusters were amplified and sequenced for the Japanese pit viper, himehabu. In one of these clusters, which in most vertebrates characterized to date contains three tightly connected genes for tRNA(Ile), and tRNA(Gln), and tRNA(Met), a sequence of approximately 1.3 kb was found to be inserted between the genes for tRNA(Ile) and tRNA(Gln). The insert consists of a control-region-like sequence possessing some conserved sequence blocks, and short flanking sequences which may be folded into tRNA(Pro), tRNA(Phe), and tRNA(Leu) genes. Several other snakes belonging to different families were also found to possess a control-region-like sequence and tRNA(Leu) gene between the tRNA(Ile)and tRNA(Gln) genes. We also sequenced a region surrounded by genes for cytochrome b and 12S rRNA, where the control region and genes for tRNA(Pro) and tRNA(Phe) are normally located in the mtDNAs of most vertebrates. In this region of three examined snakes, a control-region-like sequence exists that is almost completely identical to the one found between the tRNA(Ile) and tRNA(Gln) genes. The mtDNAs of these snakes thus possess two nearly identical control-region-like sequences which are otherwise divergent to a large extent between the species. These results suggest that the duplicate state of the control-region-like sequences has long persisted in snake mtDNAs, possibly since the original insertion of the control-region-like sequence and tRNA(Leu) gene into the tRNA gene cluster, which occurred in the early stage of the divergence of snakes. It is also suggested that the duplicated control-region-like sequences at two distant locations of mtDNA have evolved concertedly by a mechanism such as frequent gene conversion. The secondary structures of the determined tRNA genes point to the operation of simplification pressure on the T psi C arm of snake mitochondrial tRNAs.