Precipitation of submicron charged particles in human lung airways

Precipitation of charged particles in a tube by their own space charge is investigated theoretically, when the number density of the particles is large enough so that the potential is a smooth function given by Poisson’s equation, and when the number density is small so that only the image force is important. These two approaches have been applied to the data given by Weibel for the human lung, to determine the deposition probabibilities at different generations for submicron particles when the particle density is 1×10⁵ particles/cm³. The results indicate that the electrostatic dispersion can only lead to a small effect on the lung deposition, the predominant effect is due to the image force exerted on the particles.     

In vitro differentiation in callus cultures of moth bean,Vigna aconitifolia (JACQ) marechal

Callus cultures of two cultivars of Vigna aconitifolia (IPCMO-926, RDM-120) were raised and their growth and differentiation studied. In IPCMO-926 callus cultures, numerous shoot buds differentiated on MS medium with BA (0.4–22.2 μM) alone or in combination with IAA (5.7 μM). In RDM-120 best differentiation of shoot buds was observed on a medium with K (23.2 μM) and IAA (5.7 μM). Kinetin alone, however, induced rhizogenesis in callus cultures. In suspension cultures of IPCMO-926 embryoids differentiated on MS medium with K (0.5 μM) and 2,4-D (0.4 and 0.9 μM).     

Effect of oilseed cakes on alpha-amylase production by Bacillus licheniformis CUMC305.

The effects of oilseed cakes on extracellular thermostable alpha-amylase production by Bacillus licheniformis CUMC305 was investigated. Each oilseed cake was made of groundnut, mustard, sesame, linseed, coconut copra, madhuca, or cotton. alpha-Amylase production was considerably improved in all instances and varied with the oilseed cake concentration in basal medium containing peptone and beef extract. Maximum increases were effected by a low concentration (0.5 to 1.0%) of groundnut or coconut, a high concentration (3%) of linseed or mustard, and an Rintermediate concentration (2%) of cotton, madhuca, or sesame. The oilseed cakes made of groundnut or mustard could completely replace the conventional peptone-beef extract medium as the fermentation base for the production of alpha-amylase by B. licheniformis. The addition of corn steep liquor to cotton, linseed, sesame, or madhuca cake in the medium improved alpha-amylase production.     

Interaction of the carboxamide of NADPH with Lactobacillus casei dihydrofolate reductase

Dihydrofolate reductase from Lactobacillus casei and its complexes with NADPH and methotrexate yield well-resolved Raman spectra. The 1685-cm^?1 Raman band assigned to the carboxamide of NADPH persists in the NADPH-enzyme binary complex but is absent from the NADPH-methotrexate-enzyme ternary complex. This is ascribed to stabilization of the polarized form of the carboxamide by H bonding to the NH and CO groups of Ala 6 and Ile 13 of the peptide backbone.     

Molecular cloning and characterization of prolactin-like protein C complementary deoxyribonucleic acid.

In this report, we describe the isolation and characterization of a full length cDNA clone for rat prolactin-like protein C (PLP-C) and describe the expression of PLP-C mRNA in the developing rat placenta. Nucleotide sequence analysis of the PLP-C cDNA clone predicted a mature protein of 238 amino acids, including a 30-amino acid signal sequence. The predicted PLP-C amino acid sequence contains seven cysteine residues, three tryptophan residues, and two putative N-linked glycosylation sites. Six of the cysteine residues in PLP-C are located in positions homologous to the cysteines of pituitary prolactin (PRL). Additional sequence similarities with pituitary PRL and other members of the rat placental PRL family are evident. The PLP-C gene was localized to rat chromosome 17. Northern blot analysis showed that the PLP-C cDNA clone specifically hybridized to a 1.0-kilobase mRNA. PLP-C mRNA was first detectable between days 13 and 14 of gestation, peaked by day 18 of gestation, and remained elevated until term. In situ hybridization analysis indicated that PLP-C mRNA was specifically expressed by spongiotrophoblast cells and some trophoblast giant cells in the junctional zone region of rat chorioallantoic placenta.     

Identification and characterization of a new member of the prolactin family, placental lactogen-I variant

This report describes the identification and characterization of a new member of the placental prolactin (PRL) family, termed placental lactogen-I variant (PL-Iv). PL-Iv was isolated from medium conditioned by late gestation placental explants. Rat PL-Iv was found to be closely related to rat PL-I. Amino-terminal sequence analysis indicated that PL-Iv shared approximately 88% sequence identity with the amino terminus of PL-I. PL-Iv proteins cross-reacted with antiserum to recombinant mouse PL-I and PL-Iv mRNA hybridized with a PL-I cDNA. Multiple PL-I and PL-Iv species were present in placental cytosol. Despite the structural similarities between PL-I and PL-Iv, distinct differences were also evident. Antibodies generated to the amino-terminal 19 amino acids of PL-Iv specifically recognized PL-Iv, while failing to recognize PL-I. Secreted PL-Iv had an affinity for concanavalin A, whereas secreted PL-I lacked affinity for the lectin. PL-I was predominantly secreted as a 36-40-kDa species and PL-Iv was predominantly secreted as a 33-kDa species. Furthermore, PL-I and PL-Iv were synthesized at different times during gestation and by different cell types. PL-I was synthesized by trophoblast giant cells during the first half of gestation, while PL-Iv was predominantly synthesized by spongiotrophoblast cells during the later stages of gestation. PL-Iv was shown to stimulate the proliferation of rat Nb2 lymphoma cells, an in vitro measure of lactogenic activity. In summary, PL-Iv shares structural similarities with PL-I; however, it shows other structural differences in addition to unique cell- and temporal-specific patterns of expression in the rat chorioallantoic placenta.     

Nonradioactive in situ localization of poly(A)+ RNA during pollen development in anthers of tobacco (Nicotiana tabacum L.)

Summary A method is described for non-radioactive labeling of total mRNA [poly(A)+ RNA] in plastic-embedded plant tissue sections. Oligo-deoxythymidylic acid (oligo-dT) labeled with digoxigenin-conjugated dUTP was used for in situ hybridization to poly(A)+ RNA in sections of tobacco (Nicotiana tabacum) anthers. The digoxigenin was immuno-stained using antidigoxigenin IgG and gold-labeled protein-A, followed by silver enhancement of the gold label. Reproducibly similar positive staining patterns were obtained with digoxigenin-labeled oligo-dT and polyuridylic acid [poly(U)], but not with a similarly labeled sense probe, poly(A). In the developing anthers, from the onset of meiosis to the production of pollen grains, labeling patterns were compatible with a gradual depletion of nuclear and chromosome-associated sporophytic mRNA molecules during prophase of meiosis, followed by postmeiotic production of gametophytic mRNA in microspore nuclei and the vegetative nuclei of the pollen grains.Abbreviations BSA bovine serum albumin - DIG digoxigenin - IgG immunoglobulin-G - oligo-dT oligo-deoxythymidylic acid - PAS-ABB periodic acid Schiff-aniline blue black - PBS phosphate buffered saline - poly(A) polyadenylic acid - poly(U) polyuridylic acid - SSC standard saline citrate     

In vitro protein degradation measured by differential loss of labeled methionine and 3-methylhistidine: The effect of insulin

A new technique for studying the effect of insulin on protein degradation is reported. The method is based on measuring the parallel release of a reutilizable and a nonreutilizable amino acid from muscle protein. Animals are prelabeled in vivo with [Me-³H]methionine which labels both the nonreutilizable 3-methylhistidine and the reutilizable methionine of tissue protein. The data presented show that insulin has only a trivial effect on the loss of 3-methylhistidine from muscle protein, while it substantially diminishes the efflux of methionine. The analysis of muscle protein confirms the observation that insulin causes the reincorporation of methionine and has a minimum effect on the loss of 3-methylhistidine. This supports the view that the major inhibitory effect of insulin on gluconeogenesis is the diversion of the flow of amino acids away from the gluconeogenesis pathway back toward protein synthesis.