Continuous daytime and nighttime forecast of atmospheric optical turbulence from numerical weather prediction models.

Future satellite-to-ground optical communication systems will benefit from accurate forecasts of atmospheric optical turbulence; namely for site selection, for the routing and the operation of optical links, and for the design of optical communication terminals. This work presents a numerical approach based on the Weather Research and Forecasting software that enables continuous forecast of the refractive index structure parameter, 2, vertical profiles. Two different 2 models are presented and compared.

Cytochrome P-450 2E1 activity and oxidative stress in alcoholic patients.

As cytochrome P-450 2E1 (CYP2E1) induction was related to oxidative stress in experimental models, the aim of this study was to investigate the relationship between CYP2E1 activity and markers of oxidative stress in 40 alcoholic patients entering a rehabilitation programme. Plasma oxidized proteins, lipid peroxides (LPO) and antibodies against hydroxyethyl radical (HER) or malondialdehyde (MDA) adducts were assessed as markers of the production of free radicals, whereas vitamin E levels were evaluated as a marker of the antioxidant defence. CYP2E1 activity was determined by using the 6-hydroxychlorzoxazone:chlorzoxazone blood metabolic ratio, 2 h after drug intake.

Involvement of cytochromes P-450 2E1 and 3A4 in the 5-hydroxylation of salicylate in humans.

Hydroxylation of salicylate into 2,3 and 2,5-dihydroxybenzoic acids (2,3-DHBA and 2,5-DHBA) by human liver microsomal preparations was investigated. Kinetic studies demonstrated that salicylate was 5-hydroxylated with two apparent Km: one high-affinity Km of 606 microM and one low-affinity Km greater than 2 mM. Liver microsomes prepared from 15 human samples catalyzed the formation of 2,5-DHBA at metabolic rate of 21.

Cytochrome P450 2E1 activity in diabetic and obese patients as assessed by chlorzoxazone hydroxylation.

Cytochrome P450 2E1 (CYP2E1) is a phase I detoxification enzyme, which is induced by chronic alcohol consumption. It is involved in the activation of numerous carcinogens and in the production of free radicals. As it has previously been shown to be induced in diabetic and obese rats, the aim of this study was to investigate its induction level in poorly-controlled diabetics and in obese patients (Body Mass Index > 30 kg/m2).

Cytochrome P450 4A and 2E1 expression in human kidney microsomes.

Laurate and arachidonate omega and (omega-1)-hydroxylase activities, cytochrome P450 2E1 (CYP2E1), and CYP4A content were measured in 18 human kidney microsomal samples. The rates of laurate and arachidonate were found to be very different from those measured in human liver samples, with a laurate omega/omega-1 ratio of approximately 22 in human kidney vs 0.75 in human liver.

Interaction of methadone with substrates of human hepatic cytochrome P450 3A4.

Methadone, a synthetic drug, is one of the most widely used drugs for opiate dependency treatment. This drug has been demonstrated to be extensively metabolized by cytochrome P450 3A4 in human liver microsomes. Thus, the aim of this in vitro study was to determine if methadone is an inhibitor of other P450s characterized by their specific catalytic activities.

Effect of acetaldehyde generated from ethanol by ADH-transfected CHO cells on their membrane fatty acid profiles.

Ethanol has been previously shown to reduce the unsaturated fatty acid content of cell membranes. It is not known, however, if the observed deleterious effects are due to ethanol itself or its metabolite, acetaldehyde. The present study was undertaken to assess the effect of acetaldehyde produced from ethanol by alcohol-deyhdrogenase-transfected Chinese hamster ovary Cells on the membrane lipids and the lipid peroxidation measured by free and bound malondialdehyde (MDA).

Cytochromes P4502E1 and P4501A1 genotypes and susceptibility to cirrhosis or upper aerodigestive tract cancer in alcoholic caucasians.

Genetic polymorphisms of various cytochromes P450 have recently been described and could be implicated in the individual susceptibility of alcoholics to ethanol-related diseases. Rsal and Dral polymorphisms of CYP2E1 and Mspl polymorphism of CYP1A1 were studied in 260 controls and 511 alcoholic patients, without any clinical symptoms (n = 202) or with various ethanol-related diseases (n = 309), such as liver cirrhosis (n = 110), esophageal cancer (n = 62), upper aerodigestive tract cancer (n = 96), and other miscellaneous diseases (n = 41). Frequencies of the mutated alleles were found to be 2.

Determination of cytochrome P450 2E1 activity in microsomes by thin-layer chromatography using [2-14C]chlorzoxazone.

A thin-layer chromatographic assay was developed as an alternative method for the determination of cytochrome P450 2E1 (CYP2E1) in microsomes using [2-14C]chlorzoxazone. After incubation of microsomes with 0.125 microCi/mmol chlorzoxazone, chlorzoxazone and its single metabolite, 6-hydroxychlorzoxazone, were extracted using chloroform-2-propanol (85:15, v/v) and chromatographed on silica gel 60 F254 plates with acetone-hexane (45:55, v/v) as solvent .

Cytochrome P450 2E1 genotype and chlorzoxazone metabolism in healthy and alcoholic Caucasian subjects.

Susceptibility to cancer or ethanol-related liver diseases may be associated with a large variability in cytochrome P450 2E1 activity. This variability may be of genetic origin or reflect environmental factors. To test the role of genetics, the phenotype and genotype of this enzyme were determined in 42 non-alcoholic and 74 alcoholic patients hospitalized for detoxification treatment.

Effects of various cytochrome P-450 inducers on testosterone metabolism and several monooxygenase activities in Sprague-Dawley (SpD), high alcohol sensitivity (HAS) and low alcohol sensitivity (LAS) rats.

Hydroxylation of testosterone (TST) has been shown to be regio- and stereo-specific for a number of cytochrome P-450 isoenzymes. Three rat lines [Sprague-Dawley (SpD), high alcohol sensitivity (HAS) and low alcohol sensitivity (LAS)] were tested for this enzymatic specificity after treatment with phenobarbital, clofibrate, 3-methylcholanthrene and pregnenolone-16 alpha-carbonitrile. These compounds are known to induce cytochrome P-450 2B, 4A, 1A and 3A1, respectively, in the rat.

[Results of dietary evaluation during calcium oxalate and calcium phosphate lithiasis].

In order to better understand the role of diet in etiology of urolithiasis, 84 oxalo-phospho-calcic-lithiasic patients (52 men, 32 women) have been studied by a nutritional week-interview and by urinary and blood testing. Diet data were compared to an ideal standard. Total caloric intake was 2428 +/- 651 calories/d; this intake is high in 7% women and 40% men.

Acetaldehyde adducts with haemoglobin: determination of acetaldehyde released from haemoglobin by acid hydrolysis.

Acetaldehyde, the first metabolite of ethanol, reacts with haemoglobin in vitro to produce acetaldehyde-haemoglobin adducts. Some clinical studies on the minor haemoglobins have suggested that these adducts may be formed in people abusing alcohol. Under hydrolysis of haemoglobin, with oxalic acid at 100 degrees C in sealed vials, some acetaldehyde was released and then specifically determined by HPLC.

Acetaldehyde adducts with serum proteins: effect on diazepam and phenytoin binding.

The in vitro effects of acetaldehyde treatment on the binding of phenytoin and diazepam to human serum albumin (HSA) and human serum proteins (HSP) have been investigated. The incorporation of acetaldehyde into proteins following incubation with different concentrations of [1,2-14 C]-acetaldehyde (0.5, 25, 100 mmol/l) was carried out.

Heteroassociation of O- and N-isopropyl derivatives of barbital and phenobarbital with 9-ethyladenine.

Heteroassociation of O- and N-isopropyl derivatives of barbital and phenobarbital with 9-ethyladenine (9-EA) in CCl4 solutions were studied by infrared spectroscopy. Cyclic heterodimers of high stability (725 less than KH less than 1960 1 X mol-1) compared to the corresponding homodimers (20 less than KD less than 60 1 X mol-1) were formed. The heteroassociation constants are interpreted in terms of both the hydrogen bonding tendency of the donor and acceptor centres and the number of sites available for the formation of hydrogen bonds.

Lipoprotein composition in agnogenic myeloid metaplasia.

Lipoproteins have previously, been studied in various myeloproliferative disorders. This study focused only on agnogenic myeloid metaplasia (AMM). Total cholesterol (TC), phospholipids (PL) and triglycerides (TG) were measured not only in serum but also in HDL, VLDL and LDL with in the same time total apolipoproteins A1 and B.

Glycosylated haemoglobin: high-performance liquid chromatographic determination of 5-(hydroxymethyl)-2-furfuraldehyde after haemoglobin hydrolysis.

A specific and accurate method for the quantitation of the azomethine linkage present in non-enzymatically glycosylated haemoglobin is described. This protein is hydrolysed for 5 h in 1 M oxalic acid at 100 degrees C to yield 5-(hydroxymethyl)-2-furfur-aldehyde (5-HMF), known as a specific degradation product of hexoses linked to the protein. 5-HMF is then purified through a Sep-Pak C18 cartridge and measured by its absorption at 280 nm after separation on a C18 reversed-phase silica column.

[A detailed lipidograph: enzymatic determination of cholesterol, phospholipids and glycerides in plasma lipoprotein after a cellulose acetate electrophoretic procedure (author's transl)].

The specific determination of cholesterol and its evaluation in lipoproteins separated by cellulose acetate electrophoresis is described. Using this technique, the authors extended the specific lipid determinations to phospholipids and glycerides. The precision, linearity, accuracy of the methods are satisfactory for fractions greater than 10%.

[HDL phospholipids determination after precipitation by concanavalin A (author's transl)].

The interest in the HDL phospholipids determination for cardiovascular disease investigations leads us to study its determination by an easy and accurate procedure: precipitation of lipoproteins bound to apo B with concanavalin A and determination of phospholipids in the supernatant by an enzymatic procedure. From our preliminary study, we refuse the heparin Mn Cl2 precipitation. Our method is compared with phosphotungstate Mg Cl2 precipitation procedure.