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A method to determine the concentration of Ara-a in plasma by reversed phase high performance liquid chromatography is established. The method offers the advantage of rapid and simple preparation of plasma samples and sampling volumes as small as 0.5 ml. There is no need to extract Ara-A (adenine arabinoside) or to remove or modify sugar moieties to obtain samples of adequate separation. In pharmacokinetic studies, when amounts of clinical material are small and large numbers of assay are required, the present method is very useful. The calibration curve is linear for a wide range of concentration. The recovery is 87.5%. After a single dose of Ara-A-NC adenine arabinoside nanocapsules or Ara-A injection via intravenous administration in rabbits, the Ara-A concentration in plasma was determined by this method. The pharmaceutical parameters of Ara-A-NC and Ara-A injections were obtained by using PKBP-N1 program in NEC computer. The data obtained fitted an open two-compartment model well with two correlation coefficients more than 0.99. In mice given Ara-A injection a shorter elimination half-time (20.32 min), MRT (9.647 min) and a smaller AUC (233.4 micrograms.min.ml-1) were obtained compared with the group given Ara-A-NC injection. For the latter, the figures were 67.82 min, 156.7 min and 309.9 micrograms.min.ml-1, respectively. It can be concluded that NC can alter the pharmacokinetic behavior of Ara-A in mice significantly and keep the drug at a higher level and for a longer time.

A novel glucooligosaccharide oxidase was purified 495-fold from wheat bran culture of a soil-isolated Acremonium strictum strain T1 with an overall yield of 21%. This enzyme was composed of a single polypeptide chain with a molecular mass of 61 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis and size-exclusion high-performance liquid chromatography. Its isoelectric point was pH 4.3-4.5. This enzyme contained 1 mol of FAD per mol of enzyme and showed absorption maxima at 274, 379 and 444 nm. This enzyme was stable in the pH range of 5.0 to 11.0 with an optimal reaction pH of 10.0. The optimal reaction temperature was 50 degrees C. It was stable up to 50 degrees C for 1 h at pH 7.8. This enzyme oxidized those oligosaccharides with glucose residue on the reducing end and each sugar residue jointed by alpha or beta-1,4 glucosidic bond. The relative activity of this enzyme toward maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose, maltoheptaose, lactose, cellobiose and glucose was 100:94:74:46:66:56:64:47:59. To our knowledge, this is the first report on the discovery of an glucooligosaccharide oxidase as judged from enzyme substrate specificity.

Glutathione reductase was extracted from toluene-treated baker's yeast cells by a two-stage buffer autolysis method. The yeast cells were treated with toluene for 1 h at 40 degrees C. After removal of the toluene, the cells were then allowed to autolysis in buffer for 72 h at 4 degrees C. The cells were collected and resuspended in buffer. A second stage autolysis was carried out for another 96 h at 4 degrees C. The enzyme was purified to 786-fold from the second stage cell autolysate by using two steps of affinity chromatography with triazine dyes (Yellow H-E4G and Yellow H-E6G) coupled to Sepharose CL-4B. By using this simplified method, 1.44 mg (165 units/mg) of glutathione reductase was obtained from 65 g (wet weight) of yeast cells, equivalent to 80% enzyme recovery.

476 cases of paroxysmal nocturnal hemoglobinuria (PNH) were analysed and compared with PNH patients in foreign countries and its classification was discussed. The clinical characteristics in Chinese PNH patients were: males were affected more; the age of onset was young; more common in north China; hemoglobinuria as an initial symptom was less common; thrombosis as a complication was relatively rare; the common causes of death were heart failure, infections and hemorrhage; and bone marrow picture might show mild dyshematopoiesis.

The diastereomeric components of the calcium channel antagonist RS-93522-004 are separated as the bis-3,5-dinitrobenzoate ester by reversed-phase high-performance liquid chromatography. The diastereomer ratio determination is shown to be precise, accurate and sensitive, and is not affected by the reaction yield of the derivatization with 3,5-dinitrobenzoyl chloride. The four individual stereoisomers of RS-93522-004 were independently shown to have equal reactivity toward 3,5-dinitrobenzoyl chloride.

Mutants showing negative oxidase-reaction have been isolated from Pseudomonas aeruginosa following mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. These mutants were compared to the wild type cells with respect to their respiratory activities and cytochrome contents. They exhibit lower respiration rates and contain much less cytochrome c's which are responsible for their weak or negative oxidase-reaction in these mutants. This is supported in part from an initial linear relationship observed between the measured oxidase activities and the lower cytochrome c contents in these mutants. Further evidence comes from analyzing oxidase-negative cells of P. syringae, in which low cytochrome c contents similar to these oxidase mutants account for negative oxidase activities. Cytochrome o was the sole oxidase found among these mutants as well as in the wild type cell, suggesting that cytochrome c + o complex is responsible for the tetramethyl-p-phenylenediamine-oxidase activity in these mutants as the case in the wild-type cells. From the spectral characteristics it seems that all mutants contain about the same amount and type of terminal oxidase as that of the wild-type cells. The mutation occurred which altered the oxidase activities in these mutants appears to affect cytochrome c gene(s), but not the terminal oxidase gene(s).

The membrane-bound cytochrome O has been solubilized from the Azotobacter vinelandii electron transport particle and further purified by use of conventional chromatographic procedures. The spectral characteristics as well as the other properties noted for purified cytochrome O are reported herein.

Using 3H-TdR labelling radioautography in vitro, labelling index (LI) of the bone marrow cells from patients with CML was estimated before and after treatment by indirubin, and compared with myleran. The results showed that LI of the bone marrow cells was prone to decline after treatment by indirubin or myleran, and it was most marked on the myelocyte and polychromatophilic erythroblast. The LI reduction was less by indirubin than myleran. It suggests that the inhibition of indirubin on the bone marrow cells be weaker than that of myleran. However, long-term administration of indirubin would inhibit not only the granulocytic series but also the red cell series to a certain degree.

Utilizing restriction endonuclease mapping and blot hybridization, we have determined the arrangement of the alpha-globin genes in a Chinese family. The father and mother had no obvious alpha-thalassemia symptoms, but their twin daughters suffered from HbH disease. The gene analysis showed that the mother had three alpha-globin genes in one chromosome and no alpha-globin gene in the other (alpha alpha alpha/--), the father was a heterozygote of alpha-thal2 (alpha alpha/-alpha). Their twin daughters were double heterozygotes of alpha-thall and the rightward deletion genotype alpha-tha12 (--/-alpha).