Pneumocystis carinii shows DNA homology with the ustomycetous red yeast fungi

Pneumocystis carinii causes life-threatening pneumonia in T-lymphocyte-immunodeficient subjects in transplant and oncology units or with acquired immune deficiency syndrome (AIDS). Recent DNA homology studies show P. carinii to be a fungus. To investigate the biology and epidemiology of this parasite further, we elected to determine for it a more precise taxonomic assignment within the fungal kingdom. We screened a wide range of organisms representing the major orders of fungi using DNA amplification and subsequently sequenced a portion of the mitochondrial gene encoding the large subunit ribosomal RNA. Our data show that the opportunistic pulmonary pathogen P. carinii is closely related to the ustomycetous red yeast fungi, a group which includes organisms that are extensively distributed throughout the environment and which release many widely dispersed airborne spores.     

Lithium suppresses ovariectomy-induced surges in plasma gonadotropins in rats

We have reported earlier that administration of lithium, the widely-used drug for the treatment of acute mania and prophylaxis of recurrent manic-depressive bipolar disorders, leads to a disruption of estrous cycle and a significant suppression of the proestrous surge of luteinizing hormone (LH) in a number of laboratory rodents. In this report we have examined the effects of this antimanic drug on plasma and pituitary levels of LH and follicle stimulating hormone (FSH) in rats following ovariectomy (OVX), an altered endocrine state in which the levels of serum LH and FSH are highly and chronically elevated. Adult OVX rats, maintained under standardized laboratory conditions (LD 12: 12; white lights on at 06.00 h, CST) were injected (ip) with lithium, 40 days post-operation, at a dosage of 3.0 and 2.0 mEq/Kg b. wt. for 3 and 7 days respectively (twice daily at 08.00 and 16.00 h). Control OVX rats received nothing or saline injections, whereas an intact control (C) received no surgical manipulation or drug injections of any kind. As expected, the levels of plasma LH and FSH in OVX (only) group showed nearly 6-fold and 75-fold increase respectively compared to those in C. Lithium injections in OVX rats for 3 and 7 days resulted in a significant reduction in plasma LH (P less than .005 and P less than .02 respectively) and FSH (P less than .001) levels when compared with those in the OVX control groups. Lithium also led to a significant reduction in the levels of pituitary LH after both 3 (P less than .02) and 7 days (P less than .02), but the levels of pituitary FSH remained unchanged. These results suggest that the pituitary gonadotropes constitute a definitive target for lithium's action, either directly or via the hypothalamus.     

Comparative analysis of multiple protein-sequence alignment methods [published erratum appears in Mol Biol Evol 1994 Sep;11(5):811]

We have analyzed a total of 12 different global and local multiple protein-sequence alignment methods. The purpose of this study is to evaluate each method's ability to correctly identify the ordered series of motifs found among all members of a given protein family. Four phylogenetically distributed sets of sequences from the hemoglobin, kinase, aspartic acid protease, and ribonuclease H protein families were used to test the methods. The performance of all 12 methods was affected by (1) the number of sequences in the test sets, (2) the degree of similarity among the sequences, and (3) the number of indels required to produce a multiple alignment. Global methods generally performed better than local methods in the detection of motif patterns.      

Lipase-catalysed esterification reaction in a tubular reactor

Summary Lipozyme catalysed esterification of oleic acid with lauryl alcohol was studied in a tubular recycle reactor. Water formed during the reaction was removed by adsorption, either by passing the product mixture through another column packed with molecular sieve, or by packing the reactor partially with silica gel.     

The structures of garcinones a,b and c: Three new xanthones from Garcinia mangostana

Three new tetraoxygenated xanthones (garcinones A, B and C), each disubstituted with C₅-units, have been isolated from the chloroform extract of the fruit-hulls of Garcinia mangostana. Their structures were established by a combination of spectral interpretation and chemical correlation.     

Majvinine: A new indole alkaloid of Vinca major

A new alkaloid, majvinine, was isolated from aerial parts of Vinca major. Its structure was determined by chemical and spectroscopic investigations     

Membrane lipid composition modulates the binding specificity of a monoclonal antibody against liposomes

A hybridoma secreting a monoclonal IgM 'anti-liposome' antibody was produced after injecting a mouse with liposomes containing dipalmitoylphosphatidylcholine, cholesterol, dicetyl phosphate, and lipid A. The antibody was selected by assaying for complement-dependent damage to liposomes lacking lipid A. The monoclonal antibody reacted best with liposomes containing the original immunizing mixture of lipids. Deletion of individual lipid constituents from liposomes diminished the ability of the liposomes to bind (adsorb) the antibody. Binding of the antibody was enhanced by including lipid A or galactosylceramide in the lipid bilayer, or by substituting egg phosphatidylcholine for dimyristoyl- (or dipalmitoyl-) phosphatidylcholine. Sphingomyelin could be substituted for dimyristoylphosphatidylcholine without altering the adsorption of antibody. Although the monoclonal anti-liposome antibody was completely inhibited by phosphocholine, it was probably not a conventional anti-phosphocholine antibody. The antibody apparently had a partial specificity for phosphate, and was inhibited by glycerophosphocholine, glycerophosphate, sodium phosphate, sodium sulfate, and inositol hexaphosphate, but not by choline or inositol.     

Cyclo (His-Pro): a selective inhibitor of rat prolactin secretion in vitro

Cyclo (His-Pro) (10 ng/ml), inhibits KCl (59 mM) or thyrotropin-releasing hormone (10 ng/ml) stimulated, but not basal, release of prolactin from rat hemipituitaries $\text{in vitro}$. However, cyclo (His-Pro) has no effect on the basal or stimulated release of thyrotropin and growth hormone. Cyclo (His-Pro) does not inhibit the binding of thyrotropin-releasing hormone to pituitary membrane suggesting that cyclo (His-Pro) inhibition of prolactin release is not mediated via the pituitary TRH-receptor.