Kinetics of the acid hydrolysis of diazepam, bromazepam, and flunitrazepam in aqueous and micellar systems.

A kinetic study of the acid hydrolysis of aqueous diazepam, bromazepam, and flunitrazepam was carried out at 25 degrees C using a spectrophotometric method. For diazepam and flunitrazepam, the experimental pseudo first-order rate constant decreased as the acid concentration was increased. The contrary behavior was found in the case of bromazepam.

PET evaluation of pulmonary vascular permeability: a structure-function correlation.

We compared regional measurements of the pulmonary transcapillary escape rate (rPTCER) for 68Ga-transferrin, obtained by positron emission tomography (PET), with morphometric data obtained from corresponding tissue samples in six anesthetized mechanically ventilated dogs, 1 h after oleic acid administration to either the left caudal lobe (0.015 ml/kg; Lobar group, n = 3) or the right atrium (0.08 ml/kg; Diffuse group, n = 3).

Regional lung water measurements with PET: accuracy, reproducibility, and linearity.

We evaluated the accuracy, reproducibility, and linearity of lung water concentration (LWC) measurements using positron emission tomography (PET) in anesthetized supine dogs. First, we evaluated whether errors in attenuation correction, which might occur during the development of pulmonary edema, significantly affect LWC and pulmonary blood flow (PBF) measurements obtained with PET. In 10 animals, PET scans of LWC and PBF were obtained before and after oleic acid induced lung injury.

Perfusion redistribution after alveolar flooding: vasoconstriction vs. vascular compression.

We compared the effects of left caudal lobe (LCL) alveolar hypoxia on regional pulmonary blood flow (PBF) with the effects due to alveolar edema induced by plasma instilled directly into the LCL airways of 16 dogs. Regional measurements were made with positron emission tomography. After hypoxic ventilation of the LCL (n = 11), the LCL-to-right caudal lobe (L/R) PBF ratio fell from 0.

Visualization of R-bands in human metaphase chromosomes by the restriction endonuclease MseI.

Human metaphase chromosomes were treated with the restriction endonuclease MseI, which cuts DNA at TTAA sequences. This enzyme preferentially cuts and extracts DNA from G-bands and thus is the first restriction endonuclease allowing direct R-band visualization. Specific patterns ranging from R+C-like to C-like banding can be induced, depending on the concentration of the enzyme.

Longitudinal differentiation of the human Yq heterochromatin as revealed by the restriction enzyme TaqI.

The restriction endonuclease TaqI cleaves DNA at TCGA sites which are very common in human satellite DNAs. However, this enzyme was not used successfully up to now to digest constitutive heterochromatin of human chromosomes, where those highly repetitive DNAs are preferentially located. In this work, we show that TaqI is able to cut and extract DNA from the major heterochromatic regions on chromosomes 1, 9, 15, and 16 which appear as unstained gaps.

Cryptic variants of acrocentric human chromosomes as analysed by restriction endonucleases.

Ten phenotypically normal human individuals have been analysed by in situ treatments with restriction endonucleases in order to obtain a better characterization of some cryptic variants of acrocentric chromosomes. Treatments with AluI, NdeII and Sau3AI confirm the existence of two cryptic amplified regions on the short arms of both one chromosome 15 and one chromosome 22, in one female. These amplifications seem to be of different origin involving the nucleolar organizer region of chromosome 15 and the satellite of chromosome 22.

Pulmonary blood flow distribution after lobar oleic acid injury: a PET study.

We evaluated the importance of hypoxic vasoconstriction as a mechanism for pulmonary blood flow reduction during unilobar oleic acid lung injury in dogs. Pulmonary blood flow (PBF) and lung water were measured with positron emission tomography. Data from the injured left (LCL) and right (RCL) caudal lobes were compared in 23 dogs.

Effect of regional pulmonary blood flow on extravascular lung water measurements with PET.

We examined the effect of regional pulmonary blood flow (PBF) on lung water measurements made with a blood-borne label (15O-water) and positron emission tomography (PET) in five dogs. The total lung water (TLW) content of a lung region obtained at equilibrium after intravenous injection of 15O-water (TLW-water) was compared with calculations made from lung density measurements (TLW-density) also obtained with PET. These latter measurements are proportional to the tissue attenuation of radioactivity originating from an external source encircling the animal and are independent of PBF.

A positron emission tomographic comparison of diffuse and lobar oleic acid lung injury.

We tested whether severity of injury measured from the pulmonary transcapillary escape rate for transferrin (PTCER), lung water accumulation, and changes in regional pulmonary blood flow (PBF) would be similar after oleic acid (OA) injection into either all lung lobes or directly into the pulmonary artery feeding the left caudal lobe (LCL) only. Measurements were made with positron emission tomography. After 0.

Solubility of diazepam and prazepam in aqueous non-ionic surfactants.

The solubility of diazepam and prazepam in aqueous polyoxyethylen-10-dodecanol, polyoxyethylen-23-dodecanol and polyoxyethylen-20-hexadecanol, has been determined at 25.0 degrees C. Diazepam seems to achieve a higher micellar penetration than prazepam, in spite of an expected smaller hydrophobic character.

Antibodies to AIDS-associated retrovirus (HTLV-III/LAV) in drug addicts from Vizcaya, northern Spain.

Serum samples from 313 asymptomatic intravenous (IV) drug users from Bilbao (Vizcaya, Vasque Country, Spain) were tested for antibodies to HTLV-III/LAV virus, the probable etiologic agent of the acquired immune deficiency syndrome (AIDS). Viral antibodies were assayed by ELISA test. 41.