Antimalarials. 11. Synthesis of 3- and 5-aminoquinolines as potential antimalarials

A series of 3-quinolinediamines (1g, 2c, and 3e) structurally related to primaquine and 4-methylprimaquine have been prepared and tested for antimalarial activity against Plasmodium berghei in mice and antileishmanial activity against Leishmania donovani in the hamster. All were inactive. In addition, three 5-quinolinediamines (4b, 5, and 6) were prepared. All were inactive against Leishmania donovani in hamsters. One of the examples, 6, was curative against Plasmodium cynmolgi in the rhesus monkey.

Particle size distribution analysis for the rapid detection of microbial infection of urine

The accuracy and practicality of particle size distribution analysis for rapid screening of urine specimens are assessed. Six hundred urines were subjected simultaneously to routine bacteriological examinations and particle size distribution analysis using a Coulter Counter (ZBI) linked to a C1000 Channelyzer. There was complete agreement in the results of 593 (98.8%) specimens. Characteristic profiles of various bacterial species in infected specimens were consistently obtained. This system can easily be linked to any existing computer reporting in a district hospital laboratory, and the results of negative specimens (70--80%) can be obtained within 5--10 minutes.

Extensive homologies between the methylated nucleotide sequences in several vertebrate ribosomal ribonucleic acids

The methylated nucleotide sequences in the rRNA molecules of the following vertebrate cultured cells were compared: human (HeLa); hamster (BHK/C13); mouse (L); chick-embryo fibroblast; Xenopus laevis kidney. In each species the combined 18S, 28S and 5.8S molecules possess approx. 110-115 methyl groups, and the methylated oligonucleotides released after complete digestion of the rRNA by T1 ribonuclease encompass several hundred nucleotides. "Fingerprints" of the three mammalian methyl-labelled 18S rRNA species were qualitatively indistinguishable. "Fingerprints" of digests of 28S rRNA of hamster and mouse L-cells were extremely similar to those of HeLa cells, differing in one and three methylated oligonucleotides respectively. "Fingerprints" of methyl-labelled rRNA from chick and Xenopus strongly resembled those of mammals in most respects, but differed in several oligonucleotides in both 18S and 28S rRNA. At least some of the differences between "fingerprints" appear to be due to single base changes or to the presence or absence of methyl groups at particular points in the primary sequence. The findings strongly suggest that the methylated-nucleotide sequences are at least 95% homologous between the rRNA molecules of the two most distantly related vertebrates compared, man and Xenopus laevis.

Conformation of methylated sequences in HeLa cell 18-S ribosomal RNA: nuclease S1 as a probe

18-S rRNA from HeLa cells was digested with nuclease S1. Under the conditions employed 15% of the total nucleotides and some 50% of the methylated nucleotides were released as low-molecular-weight products. The material which was precipitable by 70% ethanol after nuclease S1 digestion was subjected to further digestion by combined T1 plus pancreatic ribonucleases or by T1 ribonuclease alone, and fingerprints were prepared. It was found that the four sites which are modified late during ribosome maturation, and which contain base modifications, were all accessible to nuclease S1. By contrast fewer than one-half of the sites which are modified early during ribosome maturation, and which contain 2'-O-methyl groups, were accessible to nuclease S1; the remainder were protected, presumably by secondary or tertiary interactions within 18-S rRNA.

Methylated nucleotide sequences in HeLa-cell ribosomal ribonucleic acid. Correlation between the results from 'fingerprinting' hydrolysates obtained by digestion with T1 ribonuclease and with T1 plus pancreatic ribonuclease

The methylated nucleotide sequences in HeLa-cell rRNA were previously characterized after enzymic digestion of the rRNA by T1 ribonuclease alone or by combined T1 plus pancreatic ribonucleases. For any methylated product occurring in a T1-ribonuclease digest there must be one or more corresponding products in a combined T1-plus-pancreatic-ribonuclease digest. Here we correlate fully the inter-relationship between the methylated products occurring in the two digestion systems. The analysis has led to the resolution of some previous uncertainties and has permitted an almost complete qualitative and quantitative description of the methylated components in HeLa-cell rRNA. The data are compared with those reported by other authors for HeLa-cell rRNA.

Nucleotide sequence relationships between vertebrate 5.8 S ribosomal RNAs

Nucleotide sequences of the 5.8 S ribosomal RNAs from HeLa cells, Xenopus laevis and chick embryo fibroblasts were compared. Xenopus laevis 5.8 S RNA differs from that of HeLa cells in four internal positions and at the 3' end of the molecule. Chick 5.8 S RNA differs from that of HeLa cells in two positions. Six out of the seven interspecies differences are due to base substitutions. The other difference is due to the presence of an extra nucleotide, internally located, within the Xenopus 5.8 S sequence.

Pharmacological studies on Lepidium sativum, linn

Pharmacological studies on Lepidium sativum suggested in it the presence of a cardioactive substance, which is unstable in solution, shows tachyphylaxis and probably exerts its actions through adrenergic mechanisms.

Investigation of the binding site of human corticosteroid-binding globulin by affinity labeling. Demonstration of a cysteinyl residue in the binding site

This communication deals with the investigation of the binding site of purified human corticosteroid-binding globulin (CBG) by the method of affinity labeling. The design of the studies necessitated the rapid removal of unbound ligands, followed by assay of the binding capacity of CBG. We were able to accomplish this by demonstrating that CBG absorbed on DEAE-filter discs bound cortisol as if both molecules were in solution. Using this principle, 6beta-bromoprogesterone was shown to react with CBG in a time-dependent and irreversible fashion with a t1/2 = 15 min at 2 degrees. One mol of 6beta-bromo[3H]progesterone reacted with 1 mol of CBG. After completion of the reaction, one of the two sulfhydrul groups in CBG was no longer titratable with Ellman's reagent. The product of the reaction of 6beta-bromoprogesterone with cysteine is progesterone-6-S-L-cysteine. After acid hydrolysis of CBG, which had been incubated with 6beta-bromoprogesterone, a compound which migrated with the same mobility on thin layer chromatography as the model compound was observed. We conclude that 6beta-bromoprogesterone is an affinity label for CBG and that a cysteinyl residue is present in the binding site.

Identification of corticosteroid-binding globulin in human milk: measurement with a filter disk assay

We have studied the concentration and properties of a protein which binds cortisol in human milk in samples obtained from women during the first 100 days after delivery. A filter disk assay was developed both for the measurement of plasma corticosteroid-binding globulin (CBG) and for the cortisol-binding protein in milk. The concentration of CBG in milk, expressed as its capacity to bind cortisol, is highest on the day of delivery, ca, 0.80 mug/dl, falls over the next 10 days to ca. 0.25 mug/dl, and remains at that level thereafter. If the concentration of CBG is expressed relative to the concentration of serum albumin in milk, it increases from day 1 to day 3 and then remains constant. A detailed comparison of CBG derived from milk and plasma showed that the two proteins co-migrated on Sephadex, sucrose gradient ultracentrifugation, and polyacrylamide gel electrophoresis. The two proteins had the same affinity for cotrisol, progesterone, 17-OH-progesterone, and dexamethasone. Furthermore, the binding activity of CBG in milk was neutralized with anti-CBG antibodies raised against CBG isolated from plasma. Unlike CBG, the concentration of cortisol in milk, 0.8-3.5 mug/dl, showed no systematic variation as a function of the postpartum day on which the sample was obtained.

Comparison between the ribosomal ribonucleic acids from free and membrane-bound ribosomal fractions of HeLa cells

The rRNA species from the total cytoplasmic, free and membrane-bound fractions of HeLa cells were compared. With the use of T1 ribonuclease and combined T1 ribonuclease plus pancreatic ribonuclease 'fingerprinting' procedures, no significant differences were found between the rRNA species from the different subcellular fractions.

The post-mortem diagnosis of influenzal infection by fluorescent IgG, IgA and IgM antibody studies on necropsy blood

Necropsy blood from cases diagnosed as dying from influenza A was examined for specific antibody in the IgG, IgA and IgM fractions and a specific diagnosis of recent infection was made if either IgM or IgA antibody and low titres of IgG antibody were found. By these criteria a diagnostic rate of 77% was found in those cases from whom no virus was isolated. The use of infected cell monolayers grown on polytetrafluoroethylene-coated slides gave a simple method of carrying out these antibody assays, and the use of necropsy blood did not require any special methods of transport of specimens to the virus laboratory.

History of Medicine - Contribution of Al-Beruni in Biology

DOI: http://dx.doi.org/10.3329/bjms.v4i3.8234BJMS 1997; 4(3): 38-40

The time-factor in transport of particles by jejunal absorptive epithelium

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