Atmospheric chemistry of cyclohexanone: UV spectrum and kinetics of reaction with chlorine atoms

Absolute and relative rate techniques were used to study the reactivity of Cl atoms with cyclohexanone in 6 Torr of argon or 800–950 Torr of N 2 at 295 ± 2 K. The absolute rate experiments gave k (Cl + cyclohexanone) = (1.88 ± 0.38) × 10 −10 , whereas the relative rate experiments gave k (Cl + cyclohexanone) = (1.66 ± 0.26) × 10 −10 cm 3 molecule −1 s −1 . Cyclohexanone has a broad UV absorption band with a maximum cross section of (4.0 ± 0.3) × 10 −20 cm 2 molecule −1 near 285 nm. The results are discussed with respect to the literature data. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 223–229, 2008Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58072/1/20291_ftp.pd

Sur la p-dimension des corps

Let A be an excellent integral henselian local noetherian ring, k its residue field of characteristic p>0 and K its fraction field. Using an algebraization technique introduced by the first named author, and the one-dimension case already proved by Kazuya KATO, we prove the following formula: cd_p(K) = dim(A) + p-rank(k), if k is separably closed and K of characteristic zero. A similar statement is valid without those assumptions on k and K

Two cases of variceal haemorrhage during living-donor liver transplantation

Some patients with cirrhosis experience rupture of venous varices before operation, and liver transplantation is a therapy of last resort for these patients. However, we have experienced two cases of intraoperative rupture in whom no abnormalities of the venous varices were seen on endoscopy before operation. One patient with ruptured gastrointestinal varices was treated by direct surgical ligation and the other with ruptured oesophageal gastric varices, spontaneously recovered with a Sengstaken–Blakemore tube. These cases suggest that acute variceal haemorrhage should always be considered as a possibility during living-donor liver transplantation in patients with a history of upper gastrointestinal bleeding. Careful observation of the nasogastic tube is important during clamping of the hepatic portal vein

Hemin Treatment Abrogates Monocrotaline-Induced Pulmonary Hypertension

Treatment of rats with monocrotaline (MCT), a pyrrolizidine alkaloid plant toxin, is known to cause pulmonary hypertension (PH), and it has been used as a useful experimental model of PH. Recent findings suggested that pulmonary inflammation may play a significant role in the pathogenesis of MCT-induced PH. We also demonstrated that, following MCT administration to rats, there was a significant and sustained increase in the pulmonary expression of heme oxygenase-1 (HO-1), which is known to be induced by various oxidative stresses, including inflammation and free heme, and is thought to be essential in the protection against oxidative tissue injuries. In this study, we administered hemin (ferriprotoporphyrin chloride, 30 mol/kg b.w., subcutaneously), a potent inducer of HO-1, every 3 days to rats following subcutaneous administration of MCT (60 mg/kg) and examined its effect on MCT-induced PH and pulmonary inflammation. MCT administration caused pulmonary arterial wall thickening with marked elevation of right ventricular pressure, in association with prominent pulmonary inflammation as revealed by the increase in gene expression of tumor necrosis factor-alpha and the number of infiltrated neutrophils in the lung. In contrast, hemin treatment of MCT-administered animals, which led to a further increase in pulmonary HO-1 mRNA expression, significantly ameliorated MCT-induced PH as well as tissue inflammation. These findings suggest that hemin treatment ameliorates MCT-induced PH possibly mediated through induction of pulmonary HO-1 which leads to the attenuation of pulmonary inflammation

HIV-1 Envelope Subregion Length Variation during Disease Progression

The V3 loop of the HIV-1 Env protein is the primary determinant of viral coreceptor usage, whereas the V1V2 loop region is thought to influence coreceptor binding and participate in shielding of neutralization-sensitive regions of the Env glycoprotein gp120 from antibody responses. The functional properties and antigenicity of V1V2 are influenced by changes in amino acid sequence, sequence length and patterns of N-linked glycosylation. However, how these polymorphisms relate to HIV pathogenesis is not fully understood. We examined 5185 HIV-1 gp120 nucleotide sequence fragments and clinical data from 154 individuals (152 were infected with HIV-1 Subtype B). Sequences were aligned, translated, manually edited and separated into V1V2, C2, V3, C3, V4, C4 and V5 subregions. V1-V5 and subregion lengths were calculated, and potential N-linked glycosylation sites (PNLGS) counted. Loop lengths and PNLGS were examined as a function of time since infection, CD4 count, viral load, and calendar year in cross-sectional and longitudinal analyses. V1V2 length and PNLGS increased significantly through chronic infection before declining in late-stage infection. In cross-sectional analyses, V1V2 length also increased by calendar year between 1984 and 2004 in subjects with early and mid-stage illness. Our observations suggest that there is little selection for loop length at the time of transmission; following infection, HIV-1 adapts to host immune responses through increased V1V2 length and/or addition of carbohydrate moieties at N-linked glycosylation sites. V1V2 shortening during early and late-stage infection may reflect ineffective host immunity. Transmission from donors with chronic illness may have caused the modest increase in V1V2 length observed during the course of the pandemic