Protective antibodies in human sera against encapsulated strains of Staphylococcus epidermidis

Passive protective antibodies in 100 samples of normal human sera against challenge with three representative capsular type strains of Staphylococcus epidermidis in mice were examined. Six of them passively protected mice against capsular type I; 17 protected against capsular type II; one against capsular type III; and one against both capsular types I and II. The activities were sensitive to 2-mercaptoethanol and were absorbed out either with rabbit anti-human IgG serum, rabbit anti-human IgA serum or rabbit anti-human IgM serum. Also, the sera activities absorbed out with cell surface polysaccharide extracted from three representative capsular type strains. These results indicate that the protective activities were specifically related to three major immunoglobulins against the above cell surface polysaccharides.     

Quantitative measurement of endotoxin in rainbow trout (Salmo gairdneri) serum by the chromogenic substrate method

The amount of endotoxin in serum collected from normal rainbow trout ( Salmo gairdneri) and trout inoculated with viable Vibrio anguillarum or lipopolysaccharide (LPS) extracted from bacteria was determined by the chromogenic substrate method. The mean values of endotoxin in four different groups of normal rainbow trout sera ranged from 31.9 to 65.3 pg/ml. When fish were inoculated with viable bacteria (1 × 10⁸), they became septicaemic and a large amount of endotoxin (> 14 ng/ml) was detected in the sera. In fish inoculated with a smaller number of bacteria the amount of endotoxin was several times higher than that of normal fish in spite of failure of bacterial isolation. Although the endotoxin level in serum increased rapidly (> 100 ng/ml) after intraperitoneal inoculation with purified V. anguillarum LPS (540 μg), no fish died during the experiment. The high level of endotoxin in normal rainbow trout and the resistance of trout to endotoxin are in striking contrast to those of mammalian and avian species.     

Characterization of a chloroplast DNA sequence from Chlorella ellipsoidea that promotes autonomous replication in yeast

Summary An EcoRI 2.7 kbp fragment from Chlorella ellipsoidea chloroplast DNA (cpDNA) cloned in YIp5 was shown to promote autonomous replication in Saccharomyces cerevisiae. The fragment was localized in the small single copy region close to the inverted repeat. The ARS activity (autonomously replicating sequences in yeast) was found to be confined within a subclone of a ca. 300 bp HindIII fragment. Sequence analysis of this fragment revealed its high AT content and the presence of several direct and inverted repeats and a few elements that were related to the yeast ARS consensus sequence. Electron microscopic studies revealed that this sequence did not coincide with the primary replication origin of chloroplast DNA. The functioning of this sequence as a possible origin of plasmid replication in vivo is discussed. This is the first report on Chlorella cpDNA sequence. re]19850821 rv]19851211 ac]19851216     

Molecular characterization of mutant actin genes which induce heat-shock proteins in Drosophila flight muscles

Heat-shock proteins (hsps) are constitutively induced by the mutant actins in the Drosophila indirect flight muscles (IFM). We compared primary structures of the mutant actin genes (KM75 and HH5) which induce hsps and of the non-inducing alleles (KM129 and KM88). The KM75 actin has lost 20 amino acids at the C-terminus. The HH5 actin has only one amino acid substitution, from Gly-336 to Ser. In KM129, the C-terminal part of actin is replaced by novel amino acids. KM88 is a null allele, with an amber mutation early in the coding region of the mutated actin gene. Although all of the KM75, HH5 and KM129 actins have defects near the C-terminus, only hsp-inducing mutant actins cause enlargement of the IFM nuclei as well as a disruption of myofibrils even in the presence of two copies of the normal genes. We further consider the underlying mechanisms linking these features of the hsp-inducing alleles.     

Effects of degranulation of mast cells on proliferation of mesenchymal cells in the mesentery of mice

Summary A mast-cell activator, compound 48/80, causes proliferation of mesenchymal cells in the mesentery of rats. Its effect on W/W ^vmice deficient in mast cells was tested to determine whether the proliferation is mediated in the degranulation of mast cells. Incorporation of [³H]thymidine into mesenchymal cells in the mesentery of these mice with or without compound 48/80 was very small compared to their normal litter mates. However, bone marrow transplantation markedly enhanced the effect of compound 48/80, and resulted in an incorporation of [³H]thymidine almost comparable to that observed in normal mice. Our results provide evidence that mesenchymal cell proliferation is caused by a product secreted by mast cells when stimulated by compound 48/80.Supported by a Grant-in-Aid for Scientific Research, No. 366, from the Japanese Ministry of Health and WelfareThe authors are indebted to Drs. Motomu Minamiyama and Yukio Hirata for valuable advices, and to Miss Mitsuko Inoue for technical assistance     

Immunotherapy with bestatin for acute nonlymphocytic leukemia in adults

Summary In a cooperative randomized control study of immunotherapy with bestatin in combination with chemotherapy in adults with acute nonlymphocytic leukemia (ANLL), 101 patients (48 in the bestatin group and 53 in the control group) out of 115 patients registered were evaluated as eligible. The bestatin group achieved a statistically significant prolongation of survival compared with the control group in overall ANLL and acute myelogenous leukemia. In the analysis of patient age, the bestatin group achieved a statistically significant prolongation of both the remission duration and survival in patients aged 50 to 65 years, while the differences were not significant in the 15 to 49 age group. The bestatin group tended to achieve a higher rate of reinduction of remission in patients who had recurrence of leukemia. Side effects developed in only 5 (9.6%) of 52 patients treated with bestatin. None of these side effects were particularly serious in nature. It is concluded that bestatin is useful for prolongation of survival of adult patients with ANLL, making for a longer remission duration especially in elderly patients and with few side effects.     

Kinetics of microcolony formation of a soil oligotrophic bacterium, Agromonas sp.

Abstract The kinetics of budding/dividing of parent cells at different culture ages, spread on a fresh medium, was formulated by the following model N _t= N _∞ [1 − exp (− λ ( t − t _r)] where N _t is the number of budding/dividing cells in the parent population at time t , N _∞ is the expected number of budding/dividing cells at infinite time, λ is the rate of budding/dividing of parent cells, and t _r is the retardation time. The rate of budding/dividing λ decreased with the increase in the culture age of the parent cell population.     

Plasmid-encoded regulation of colicin E1 gene expression.

A plasmid-encoded factor that regulates the expression of the colicin E1 gene was found in molecular cloning experiments. The 2,294-base-pair AvaII fragment of the colicin E1 plasmid (ColE1) carrying the colicin E1 structural gene and the promoter-operator region had the same information with respect to the repressibility and inducibility of colicin E1 synthesis as the original ColE1 plasmid. An operon fusion was constructed between the 204-bp fragment containing the colicin E1 promoter-operator and xylE, the structural gene for catechol 2,3-dioxygenase encoded on the TOL plasmid of Pseudomonas putida. The synthesis of the dioxygenase from the resulting plasmid occurred in recA+, but not in recA- cells and was derepressed in the recA lexA(Def) double mutant. These results indicate that the ColE1 plasmid has no repressor gene for colicin E1 synthesis and that the lexA protein functions as a repressor. Colicin E1 gene expression was adenosine 3',5'-phosphate (cAMP) dependent. Upon the removal of two PvuII fragments (2,000 bp in length) from the ColE1 plasmid, the induced synthesis of colicin E1 occurred in the adenylate-cyclase mutant even without cAMP. The 3,100-bp Tth111I fragment of the ColE1 plasmid cloned on pACYC177 restored the cAMP dependency of the deleted ColE1 plasmid. Since the deleted fragments correspond to the mobility region of ColE1, the cAMP dependency of the gene expression should be somehow related to the plasmid mobilization function.     

Biosynthesis of the common precursor to vasopressin and neurophysin in vitro in transplantable human oat cell carcinoma of the lung with ectopic vasopressin production

Transplantable human oat cell carcinoma cells of the lung with ectopic vasopressin production were incubated with labeled amino acids and immunoreactive neurophysins in cell extracts were analyzed by isoelectric focusing. When the cells were incubated with L-(35S)-cysteine for 20 h, one major peak (isoelectric point; pI=5.3) and several minor peaks (pI=6.1, 5.7, 5.1, 4.9 and 4.7) of labeled proteins were observed. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the relative molecular mass (Mr) of the pI 5.7 protein was estimated to be 20,000 and that of the pI 6.1 species to be 19,000, while the remainder had a Mr of approximately 10,000. The result of the pulse-labeling experiment has clearly shown that the pI 5.7 and 6.1 proteins, which have affinity for concanavalin A, are biosynthetic precursors for the smaller form of neurophysin with a pI 5.3. When subjected to limited proteolysis with trypsin, the pI 5.7 protein generated a Mr 10,000 protein and a smaller peptide. The Mr 10,000 protein thus produced was identified as neurophysin on the basis of its pH-dependent affinity for vasopressin and the migration pattern on isoelectric focusing. The smaller peptide coeluted with synthetic arginine vasopressin and bound to neurophysin suggesting that it possesses a cysteine-tyrosyl sequence at its N-terminus. Similarly, the pI 6.1 protein liberated neurophysin and vasopressin-like peptide after incubation with trypsin. These results suggests that the glycosylated protein with a pI of 5.7 and a Mr of 20,000 is the common precursor to vasopressin and neurophysin in human oat cell carcinoma of the lung with ectopic vasopressin production. The pI 6.1 protein may be an intermediate in the conversion of the precursor to vasopressin and neurophysin.