T cells subsets responsible for clearance of Sendai virus from infected mouse lungs

T cell subsets responsible for clearance of Sendai virus from mouse lungs determined by adoptive transfer of immune spleen cell fractions to infected nude mice. T cells with antiviral activity developed in spleens by 7 days after intranasal infection. Spleen cell fractions depleted of Lyt-2+, Lyt-1+, or L3T4+ cells showed antiviral activity in vivo, although the degree of the activity was lower than that of control whole spleen cells. The antiviral activity of the Lyt-2+ cell-depleted fraction was consistently higher than that of L3T4+ (Lyt-1+)-depleted cells. In vitro cytotoxic activity against Sendai virus-associated, syngeneic lipopolysaccharide-blast cells was detected in stimulated cells from intraperitoneally immunized mice but was lost after depletion of Lyt-2+ cells. Multiple injection of anti-Sendai virus antibody into infected nude mice had no effect on lung virus titer. These results indicate that L3T4+ (Lyt-1+) and Lyt-2+ subsets are cooperatively responsible for efficient clearance of Sendai virus from the mouse lung.     

Some characteristics of a raw starch digestion inhibitory factor fromAspergillus niger

Summary The effect of an inhibitory factor (IF) fromAspergillus niger 19 on raw starch digestion by pure glucoamylase I of blackAspergillus, pure glucoamylae ofRhizopus niveus, bacterial -amylase, fungal -amylase and various combination was investigated. The IF caused higher inhibition of raw starch hydrolysis by the combined action of glucoamylase and fungal -amylase than of hydrolysis by the individual enzymes. A protein moiety of IF might play an active part in this inhibition phenomenon. The IF was bound to starch granules, preventing hydrolysis by the enzymes, and caused decreased raw starch hydrolysis yields.     

Serodiagnosis of Streptococcus pneumoniae infection in guinea pigs by an enzyme-linked immunosorbent assay

Guineapig antibodies to Streptococcus pneumoniae (SPN) serotype 19F were detected by an enzyme-linked immunosorbent assay using a simple procedure. In experimentally infected hosts, antibody was detectable as early as 2 to 3 weeks after infection, and high titres were maintained for a long period. Antibodies higher than 1:64 were regarded as specific. In a field study, high antibody titres were shown in SPN enzootic colonies in contrast to negative or low antibody titres in a majority of the animals from non-enzootic and SPF colonies.     

Phylogeny of gymnosperms inferred fromrbcL gene sequences

Partial nucleotide sequences of the large subunit of ribulose-1,5-bisphosphate carboxylase (rubisco) gene (1333 base pairs: about 90% of the gene) from several seed plants were determined. Phylogenetic trees based on amino acid sequences were inferred by using the neighbor joining and maximum likelihood methods. The results indicate (1) monophyly of gnetum group (Ephedra, Gnetum, Welwitschia), (2) monophyly of extant gymnosperms containing gnetum group, which contradicts the results of morphological data.     

Promotive Effect of C18-Unsaturated Fatty Acids on the Abscission of Bean Petiole Explants

The abscission-promoting effects of C₁₈-unsaturated fatty acidswere studied in bean (Phaseolus vulgaris L. cv. Masterpiece)petiole explants with the junction between the petiole and thepulvinus in the primary leaves in the light. Linolenic, linoleicand oleic acids promoted the abscission of the explants in thelight. Linolenic acid was the most effective among the compoundstested and its promotive effect was evident without any accompanyingincrease in the production of ethylene from the explants, ascompared with non-treated explants. Linolenic acid is easilyconverted to its hydroperoxide during the incubation with explants,as indicated by the formation of the conjugated diene and thegeneration of ethane. The production of ethylene from the explantstreated with linolenic acid was completely inhibited by theaddition of aminoethoxyvi-nylglycine (AVG), but large amountsof ethane were still generated. The promotive effect of linolenicacid was almost eliminated by the addition of scavengers offree radicals. Hydrogen peroxide and tert-butyl hydroperoxidepromoted abscission in the light. From these results, we concludedthat the abscission-promoting effect of linolenic acid are notmediated by the effect of ethylene but by the effect of itshydroperoxide, while the well-established pathway for the biosynthesisof ethylene from S-adenosylmethionine to ethylene, via 1-aminocyclopropane-l-carboxylicacid (ACC), was apparently operative. (Received May 1, 1991; Accepted July 10, 1991)     

Biocompatibility of radiolucent breast implants

Current implants for breast augmentation containing silicone gel, saline, or both are radiopaque on mammographic examination and can totally obscure microcalcifications and soft-tissue masses. The effect of these implants on the detection of early breast cancers in patients who have undergone augmentation mammaplasty remains unproven and controversial. Implants filled with medium-chain triglycerides (peanut oil) are radiolucent on mammographic examination and allow visualization of both soft-tissue masses and microcalcifications. To investigate the biocompatibility of radiolucent implants, 10 cc of sterile, nonpyrogenic peanut oil was injected subcutaneously into rats using silicone gel as a control. Twenty-one rabbits had two 125-cc silicone shell implants inserted on either side of the chest wall. The right-sided shell was filled with 125 cc of sterile saline, and the left-sided shell was filled with 125 cc of sterile, nonpyrogenic peanut oil. Results were determined by both histologic and radiographic examination. Rats injected with peanut oil equivalent to 7 percent of their body weight rapidly absorbed the freely injected oil without detriment. Histologic examination of the lungs, liver, kidneys, and tissues adjacent to the injection sites demonstrated no abnormalities. There was no evidence of allergic, toxic, inflammatory, or neoplastic response. Eighteen of 21 rabbits survived more than 3 months. Radiographs showed the oil-filled implants to be radiolucent, whereas the saline-filled controls obscured the surrounding soft and bony tissues. Histologic examination demonstrated a fibrous capsule surrounding both types of implants. Histologic examination of the lungs, liver, and kidneys showed no significant abnormalities. These and previous studies have shown peanut oil to be biocompatible when freely injected either intramuscularly or subcutaneously. This study demonstrates that a radiolucent, peanut oil-filled implant is biocompatible in animals and that further long-term studies for its use in humans are merited.     

Molecular cloning of the gene coding for the human T cell differentiation antigen CD7

The CD7 molecule is a differentiation antigen found on the surface of T lymphocytes and also on a very minor fraction of acute nonlymphocytic leukemia (ANLL). To study the genomic structure of the CD7 gene, two clones (SY4 and SY22) were isolated by screening a genomic library with a CD7 cDNA probe. Restriction mapping of these two phage clones showed that both overlapped each other, covering a total length of 23 kilobases (kb). Transfection of mouse L cells demonstrated that SY22 contains the gene expressing the CD7 antigen reactive with monoclonal CD7 antibody (Tp40), while SY4 does not. Subcloning of a 10.5 kb fragment from a 14.4 kb insert of SY22 contained the structural gene for the CD7 antigen. Detailed restriction mapping and partial sequence analysis revealed the CD7 gene to consist of four exons. By RNase protection assay, multiple initiation sites — 122 base pairs (bp) to — 38 bp from ATG translation initiation site were demonstrated. The promoter region had high G+C content and contained two SP1 binding sites (CCGCCC) and an AP2 binding site (CCCCAGGC), but lacked CAAT and TATA motifs.     

Defining the sequence recognized with BmFTZ-F1, a sequence specific DNA binding factor in the silkworm, Bombyx mori, as revealed by direct sequencing of bound oligonucleotides and gel mobility shift competition analysis.

BmFTZ-F1 is a Bombyx mori homologue of FTZ-F1, a positive regulator of the fushi tarazu gene of Drosophila melanogaster. In order to determine the sequence recognized with this factor, we made three sets of oligonucleotide mixture which contain 4 possible nucleotides at different positions within the previously proposed 12-bp binding consensus sequence. Oligonucleotides which bound to purified BmFTZ-F1 were separated by a gel mobility shift procedure and a binding sequence was determined by direct sequencing through Maxam-Gilbert method. By this analysis, 7 positions showed clear sequence preference and 5 positions showed weak or no sequence preference. The importance of each nucleotide at each position was confirmed by a gel mobility shift competition analysis and results were presented as a quantitative difference in the binding affinity. From these analyses, we conclude that the best binding sequence of BmFTZ-F1 is 5'-PyCAAGGPyCPu-3'. This method may be useful for the determination of a binding sequence of other sequence specific DNA binding factor.     

Halothane, an inhalation anesthetic, activates protein kinase C and superoxide generation by neutrophils

The rate of superoxide generation of guinea pig intraperitoneal neutrophils by a chemotactic peptide or 12-O-tetradecanoylphorbol-13-acetate (TPA) was increased by 2-bromo-2-chloro-1,1,1,-trifluoroethane (halothane), an inhalation anesthetic. This increase was inhibited by 1-(5-isoquinolinesulfonyl)methylpiperazine dihydrochloride (H-7), a specific inhibitor of Ca2+- and phospholipid-dependent protein kinase C (PKC). Halothane was found to significantly activate partially purified PKC. The activation required phosphatidylserine (PS) and Ca2+. Dioleoylglycerol- or TPA-activated PKC activity was further increased by halothane. The cytoplasmic proteins of guinea pig neutrophils phosphorylated by halothane-activated PKC were similar to those phosphorylated by PMA-activated PKC. The phosphorylation of a 48 kDa protein, a phosphorylated protein required for NADPH oxidase activation, was also increased by halothane. These data suggest that the increase of superoxide production by halothane is correlated with its activation of PKC.