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A Chaudhuri

Publications and source records attributed to A Chaudhuri.

At least 181 records · Page 10Linked to original sources
PubMed1984

Analysis of three whole-arm translocations in a mouse sarcoma cell line.

Three apparently whole-arm translocation chromosomes in the mouse sarcoma 180 ascites cell line have been studied by G- and C-banding and by Hoechst staining. All three chromosomes appear to have two centromeres. Both centromeres of one, which are very close together, are likely to be active and to produce parallel separation of the chromatids. The centromeres of the other two chromosomes are well separated. One of these two centromeres may be inactive either because the kinetochore organizer has been inactivated or because the kinetochore plate has been deleted, leaving the AT-rich centromeric constituative heterochromatin intact. The possibility that these whole arm translocations arose by telomeric fusion and the molecular basis of such fusions are discussed.

Animals↗
PubMed1983

Ag-NOR staining in mouse sarcoma ascites cells.

In sarcoma cells, the nucleoli are small, ill-defined, and are present in large numbers making it difficult to stain them by classical staining procedures. A modified Ag-NOR technique has been applied to detect the nucleolus and the nucleolar-organizing region in the chromosome of a mouse sarcoma-180 ascites cell-line. The cells were found to have 8-14 nucleolar chromosomes. The nucleoli are present in varying numbers corresponding to the number of nucleolar chromosomes. Silver grains appear as dots at one end of the chromosome. This end is presumed to be the centromeric end as, in normal mice, the NORs are in association with the centromere. However, the centromeres are ATrich, whereas the NORs should be GCrich. This NORs in mouse chromosomes should be placed below the centromere as already shown by the nucleic acid hybridization technique.

Animals↗
PubMed1983

Aspheric curvatures, refractive indices and chromatic aberration for the rat eye.

Thicknesses and curvatures of the optic components of enucleated eyes were determined in both transverse and sagittal planes. The cornea and lens surfaces are closer approximations to spheres than are the retina and choroid. Refractive indices of the cornea, aqueous and vitreous humours were obtained by two techniques at eight wavelengths across the visible spectrum. Photography of light beams passing through the crystalline lens immersed in albumin gave the "back vertex power", and thus (assuming homogeneity) the "equivalent" refractive index. With this assumption, which is supported by additional modelling, calculations for the eyes of six individual rats show chromatic aberration across the spectrum of 5.8 (5.5-6.0) diopter. Longitudinal chromatic aberration may make a significant contribution to image blur.

Animals↗
PubMed1983

Lysine excretion by S-(2-aminoethyl)L-cysteine resistant mutants of Bacillus subtilis.

S-(2-Aminoethyl)L-cysteine (AEC) at 2 X 10(-1) mM concentration completely inhibited the growth of Bacillus subtilis. This inhibitory effect was readily reversed by 2 X 10(-2) mM L-lysine. Besides L-lysine, L-aspartic acid was only effective of all the natural amino acids tested in reversing the AEC-mediated growth inhibition. AEC resistant mutants of B. subtilis were isolated and found to excrete L-lysine in high yields.

Bacillus subtilis↗
PubMed1982

Eukaryotic ribosomal subunit anti-association activity of calf liver is contained in a single polypeptide chain protein of Mr = 25,500 (eukaryotic initiation factor 6).

A protein factor that prevents the reassociation of eukaryotic 40 S and 60 S ribosomal subunits when the Mg+ concentration is raised from 1 to 5 mM has been purified to apparent electrophoretic homogeneity from postribosomal supernatant of calf liver extracts. The purified ribosomal subunit anti-association factor is a relatively heat-sensitive protein consisting of a single polypeptide chain of apparent Mr = 25,500. Direct assay for ribosomal subunit anti-association activity indicates that the majority (greater than 90% of such an activity in calf liver extracts can be accounted for by the presence of this 25,500-dalton protein factor in the postribosomal supernatant. The ribosomal salt wash protein fractions are virtually devoid of any significant ribosomal subunit anti-association or 80 S ribosome dissociation activity. The purified anti-association factor maintains a pool of ribosomal subunits by binding to 60 S ribosomal subunits and preventing them from reassociating with 40 S ribosomal subunits, rather than by dissociating 80 S monosomes. The factor neither binds to, nor seems to interact directly with, 40 S subunits. The properties of this factor are thus similar to wheat germ ribosome dissociation factor (eukaryotic initiation factor 6) described by Russell and Spremulli ((1979) J. Biol. Chem. 254, 8796-8800.

Animals↗
PubMed1982

Variation of antimetabolite sensitivity with different carbon sources in Bacillus subtilis.

The susceptibility of Bacillus subtilis to amino acid analogues was found to be markedly influenced by the carbon source used in the test media. Thialysine inhibited the bacterium with a greater number of carbon sources than the other two analogues tested. 5-Hydroxylysine was inhibitory with glycerol, lactose, D-xylose, L-arabinose and soluble starch while ethionine showed toxicity with lactose, D-xylose and L-arabinose. None of these analogues were toxic at the levels tested when D-galactose was used as carbon source. The bacterium was not susceptible to thialysine with glycerol, to 5-hydroxylysine with L-arabinose and to ethionine with lactose.

Arabinose↗
PubMed1980

An experimental study of the relationship between synergistic wound sepsis and suture materials.

In wounds on the back of guinea-pigs an inoculum of 6 x 10(5) of Escherichia coli and of Bacteroides fragilis produced a frank infection rate of 27 per cent. Addition of a catgut or a braided nylon tie statistically significantly increased the rate to 56 and 48 per cent respectively. Prolene and silk produced much smaller, non-significant rises. The rate with polyglycolic acid was 18 per cent which, though not statistically significant, suggests the possibility that this material produces conditions unfavourable to multiplication of bacteria that produce this type of infection.

Animals↗
PubMed1980

Rabbit reticulocyte initiation factor 2 contains two polypeptide chains of molecular weights 48,000 and 38,000.

Eukaryotic initiation factor 2 (eIF-20) purified from rabbit reticulocyte lysates consists of equimolar amounts of two polypeptide chains of Mr 48,000 and 38,000. Determination of the molecular weight of the native factor gave a value which is consistent with a Mr of 86,000 indicating that the factor is composed of one Mr 48,000 and one Mr 38,000 polypeptide. The purified factor exhibited all the binding activities characteristic of eIF-2. The factor formed ternary complexes with Met-tRNAfMet and GTP; it bound GDP to form a binary complex; and it also possessed the property of binding a wide variety of RNA species, including reoviral mRNA, phage T3 mRNA, rRNAs, and tRNA. Furthermore, the ternary complex formed by purified eIF-2 interacted with the 40S ribosomal subunit in the presence of AUG codon to form a 40S initiation complex. These results indicate that all binding activities attributed to eIF-2 are contained in the 48,000- and 38,000-dalton polypeptides.

Animals↗
PubMed1979

Purified eukaryotic initiation factor 2 from calf liver consists of two polypeptide chains of 48,000 and 38,000 daltons.

Eukaryotic initiation factor 2 (eIF-2), which specifically binds Met-tRNAMetf and forms stable ternary complexes with GTP, has been purified from ribosomal salt wash proteins from calf liver. The purified factor exhibits only two polypeptide bands of Mr = 48,000 and 38,000 following electrophoresis in 15% polyacrylamide gels in the presence of sodium dodecyl sulfate. Densitometric tracings show the two polypeptides are present in a molar ratio of 1:1. This suggests a Mr = 86,000 for the native enzyme, a value which agrees with the apparent molecular weight determined by physical methods. Less pure preparations of eIF-2 show additional polypeptide bands, including 50,000- and 46,000-dalton bands, all of which can be removed by further purification without affecting the activity of eIF-2.

Animals↗
PubMed1978

Sympathetic connections to the fifth and sixth cranial nerves.

Thirty additional parasellar gross dissections and light microscopic examinations have been carried out, confirming a previous observation that the sympathetic nerve or nerves running with the carotid artery gives off a multitude of fine branches at irregular intervals on the way up, but the largest residual component joins the sixth cranial nerve and leaves to join the first division of the fifth cranial nerve. No similar fibers can be found by us to the sympathetic in the neck results in a Horner's syndrome and that section of the ophthalmic artery at its point of departure from the carotid does not result in any part of Horner's syndrome nor does secretion of the external, internal or common corotid in the neck, it is assumed that these fibers process the functions the absence of which result in Horner's syndrome.

Abducens Nerve↗