Iodine-promoted amide formation via oxidative cleavage of indoles: novel quinazoline-4(3H)-one and tryptanthrin syntheses.

A highly efficient method for the direct construction of amide bonds via a selective cleavage of C-H and C[double bond, length as m-dash]C bonds in indole structures using an iodine-promoted approach was developed. Mechanistic studies indicated the formation of superoxide radicals obtained from molecular oxygen activation as a key intermediate step, which provided a precursor for subsequent oxidative ring-opening and intermolecular cyclization. A broad range of quinazolin-4(3H)-ones and tryptanthrins were synthesized in moderate to good yields under mild and environmentally benign conditions.

Increased temperature tolerance of the air-breathing Asian swamp eel Monopterus albus after high-temperature acclimation is not explained by improved cardiorespiratory performance.

This study investigated the hypothesis that in the Asian swamp eel Monopterus albus, an air-breathing fish from south-east Asia that uses the buccopharyngeal cavity for oxygen uptake, the upper critical temperature (TU) is increased by acclimation to higher temperature, and that the increased TU is associated with improved cardiovascular and respiratory function. Monopterus albus were therefore acclimated to 27° C (current average) and 32° C (current maximum temperature as well as projected average within 100-200 years), and both the effect of acclimation and acute temperature increments on cardiovascular and respiratory functions were investigated. Two weeks of heat acclimation increased upper tolerated temperature (TU ) by 2° C from 36·9 ± 0·1° C to 38·9 ± 0·1° C (mean ± s.e.). Oxygen uptake (M˙O2) increased with acclimation temperature, accommodated by increases in both aerial and aquatic respiration. Overall, M˙O2 from air (M˙O2a ) was predominant, representing 85% in 27° C acclimated fish and 80% in 32° C acclimated fish. M˙O2 increased with acute increments in temperature and this increase was entirely accommodated by an increase in air-breathing frequency and M˙O2a . Monopterus albus failed to upregulate stroke volume; rather, cardiac output was maintained through increased heart rate with rising temperature. Overall, acclimation of M. albus to 32° C did not improve its cardiovascular and respiratory performance at higher temperatures, and cardiovascular adaptations, therefore, do not appear to contribute to the observed increase in TU.

Protective effect of Tetracera scandens L. leaf extract against CCl

Objective: To investigate the protective potential of ethanolic extracts of Tetracera scandens L. (T. scandens) against CCl

Effect of salinity on oxygen consumption in fishes: a review.

The effect of salinity on resting oxygen uptake was measured in the perch Perca fluviatilis and available information on oxygen uptake in teleost species at a variety of salinities was reviewed. Trans-epithelial ion transport against a concentration gradient requires energy and exposure to salinities osmotically different from the body fluids therefore imposes an energetic demand that is expected to be lowest in brackish water compared to fresh and sea water. Across species, there is no clear trend between oxygen uptake and salinity, and estimates of cost of osmotic and ionic regulation vary from a few per cent to >30% of standard metabolism.

Air-breathing fishes in aquaculture. What can we learn from physiology?

During the past decade, the culture of air-breathing fish species has increased dramatically and is now a significant global source of protein for human consumption. This development has generated a need for specific information on how to maximize growth and minimize the environmental effect of culture systems. Here, the existing data on metabolism in air-breathing fishes are reviewed, with the aim of shedding new light on the oxygen requirements of air-breathing fishes in aquaculture, reaching the conclusion that aquatic oxygenation is much more important than previously assumed. In addition, the possible effects on growth of the recurrent exposure to deep hypoxia and associated elevated concentrations of carbon dioxide, ammonia and nitrite, that occurs in the culture ponds used for air-breathing fishes, are discussed. Where data on air-breathing fishes are simply lacking, data for a few water-breathing species will be reviewed, to put the physiological effects into a growth perspective. It is argued that an understanding of air-breathing fishes' respiratory physiology, including metabolic rate, partitioning of oxygen uptake from air and water in facultative air breathers, the critical oxygen tension, can provide important input for the optimization of culture practices. Given the growing importance of air breathers in aquaculture production, there is an urgent need for further data on these issues.

Factors associated with HIV-1 virological failure in an outpatient clinic for HIV-infected people in Haiphong, Vietnam.

The objective of our study was to investigate factors associated with virological failure in 100 consecutive HIV-1 infected Vietnamese adults who initiated antiretroviral therapy (ART) from June 2007 to June 2008. Data were collected from medical records, and a structured questionnaire was used in individual interviews to investigate factors associated with adherence to ART. Plasma HIV viral load was measured at the time of the interview. The median age was 35 years, 35% were women and heterosexual intercourse was the most common mode of HIV transmission (61%). After a median of 14 months since starting ART, 23% had detectable HIV-1 viral load (≥ 400 copies/mL). Patients who had developed a World Health Organization (WHO) clinical stage 4 condition at the time of initiation of ART were more likely to experience virological failure than those in stages 1-3, odds ratio (OR): 5.20 (95% confidence interval [CI] 1.34-20.11), P = 0.017. Patients who reported that their health status was evaluated by a physician at each visit were less likely to experience virological failure, OR: 0.02 (95% CI 0.00-0.24), P = 0.002.

A new flavone and cytotoxic activity of flavonoid constituents isolated from Miliusa balansae (Annonaceae).

A new flavone named miliufavol [8-(2-hydroxybenzyl)-5-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-3,7-dimethoxy-4H-chromen-4-one or 8-C-(o)-hydroxybenzylpachypodol] from Miliusa balansae (Annonaceae) was isolated and structurally elucidated by spectroscopic means besides four known flavones: ombuine, chrysosplenol B, pachypodol and chrysosplenol C. These flavonoids exhibited interesting cytotoxic activity against three human cell lines (KB, Hep-G2, RD) with IC50 values < 5 microg/ml.

Cleaving of S-mandelonitrile catalyzed by S-hydroxynitrile lyase from Hevea brasiliensis--a kinetic investigation based on the rate curve method.

The progress curves of conversion of racemic-mandelonitrile (R-MN) at different concentrations to benzaldehyde (BA) and hydrogen cyanide (HCN), catalyzed by S-hydroxynitrile lyase from Hevea brasiliensis, together with the enantiomeric excess curves of R-MN are converted into individual progress curves of the S- and R-enantiomers. They reveal that, under the prevailing experimental conditions, the non-enzymatic conversion is sufficiently slow compared to its enzyme-catalyzed counterpart, so that it can be ignored in a simplified analysis. Tikhonov regularization is then used to convert the progress curves of the S-enantiomer into reaction rate curves. These curves are used to determine the rate constants in the rate expression based on a three-step reversible ordered Uni-Bi reaction scheme that describes this enzyme-catalyzed reaction. The resulting rate constants are compared against published data. Some of the problems encountered and their solution are briefly discussed.

Changes in free amino acids in the hemolymph of giant freshwater prawn Macrobrachium rosenbergii exposed to varying salinities: relationship to osmoregulatory ability.

Changes in free amino acids (FAA) in the hemolymph of the giant freshwater prawn, Macrobrachium rosenbergii, were examined in individuals exposed to varying salinities for up to 1 week. In freshwater and under conditions of low salinity, total FAA concentrations were maintained between approximately 0.85 and 1 mM and did not exhibit changes in response to salinity exposure. Under high salinities, total FAA concentrations increased dramatically, reaching up to 2.1 mM depending on treatment. Examination of individual amino acid concentrations revealed that these increases were based on specific changes in glycine, arginine, alanine, proline and lysine. Among these, alanine showed the greatest increases, resulting in levels six-fold higher under high salinity than in freshwater and under low salinity. The other amino acid species showed increases of 2.5-fold compared to original values. These five FAAs in freshwater and under low salinity together occupied approximately 45% of total FAA contents and under high salinity comprised more than 70% of total FAA contents. These results suggest that specific hemolymph FAAs are involved in mediating response to salinity exposure in freshwater prawns.

Determination of amino acid sequence and site of mRNA expression of four vitellins in the giant freshwater prawn, Macrobrachium rosenbergii.

Four major yolk proteins, designated as vitellins (Vns) Macr-VnA, B, C, and D, were extracted from mature ovaries of Macrobrachium rosenbergii. These were purified to homogeneity by reversed-phase high performance liquid chromatography (HPLC) employing a unique separation system based on the hydrophobic properties of the Vn molecule. Using standard techniques of protein sequencing, more than 33 N-terminal and 57 internal amino acid residues were determined for each of the four Vns. The cDNA fragments encoding the four Vns were amplified by PCR using degenerate oligonucleotide primers derived from the N-terminal and internal amino acid sequences. These cDNA fragments were cloned, sequenced, and used as probes to examine the transcription of mRNAs encoding the four Vns. Significant accumulations of these mRNAs were observed in female hepatopancreas only, while mRNA expression was not detected in male hepatopancreas or any other female tissue including ovary, subepidermal adipose tissue, gill, and muscle. This is the first occasion in Crustacea in which multiple Vns were demonstrated to be synthesized simultaneously in a single tissue.

Pregnancy in patients with Wegener's granulomatosis: report of five cases in three women.

Five cases of pregnancy occurring in three women with previously diagnosed Wegener's granulomatosis are described. The disease was diffuse in one case and localised in the other. Initial treatment consisted of a combination of corticosteroids and intravenous cyclophosphamide in two women, and methotrexate in one. Four pregnancies ended in live births despite pre-eclampsia in two cases. One therapeutic abortion was induced because of encephalocele. Comparable reported cases were reviewed to examine the implications of immunosuppressive treatment on the fetus. A relapse occurred during pregnancy in 40% of the cases, but in 25% if only pregnancies beginning during inactive disease were taken into account. No other indicator for maternal and fetal outcome was obvious. Pregnancy should be planned after complete disappearance of disease activity. In the case of a relapse a combination of immunosuppressive drugs and corticosteroids should be chosen rather than corticosteroids alone because the outcome of pregnancy is poor in cases of undertreatment. Prematurity remains common.

Inhibitory activity of monoamine oxidase by coumarins from Peucedanum japonicum.

Four coumarins were isolated from chloroform extract of the root of Peucedanum japonicum and identified as praeruptorin A(1), xanthotoxin (2), psoralen (3) and bergapten (4) on the basis of spectroscopic methods. The inhibitory activities of these coumarins on monoamine oxidase prepared by mouse brain were tested. The IC50 values of them were shown to be 27.4 microM (1), 40.7 microM (2), 35.8 microM (3), and 13.8 microM (4), in vitro.