A growth-promoting factor existing on the body surface of rats

Effects of water-soluble matter adhering to rat hairs on fibroblasts were examined. The dialysate of the wash water of rat hairs significantly enhanced the cell proliferation of both diploid human dermal fibroblasts (DHDF) and diploid rat fibroblasts (DRDF). The cell growth-promoting activity was partially purified by a gel filtration column chromatography. The activity permeates through a ultrafiltration membrane (M.W. cut off: 500). Analyses of its chemical nature show that it is soluble in water, dimethyl sulfoxide or acetonitrile, insoluble in other organic solvents examined, stable to heat or pH shock, and resistant to a bacterial protease.     

Effect of volume expansion on hemodynamic variables in nephrectomized dogs

We have previously demonstrated that blood pressure elevation by acute blood volume expansion is volume-dependent during the infusion period and resistance-dependent in the post-infusion period in normal anesthetized dogs, and that such an increase in blood pressure is associated with a potentiation of the pressor response to norepinephrine. To evaluate the possible renal contribution to these hemodynamic changes, blood volume expansion was performed for 1 h with dextran dissolved in lactated Ringer's solution (20 ml/kg) in 15 nephrectomized dogs. The mean blood pressure, cardiac output and total peripheral resistance at the end of infusion were 126%, 225% and 60%, respectively; 3 h after volume expansion they were 126%, 151%, and 92% respectively. However, in 4 dogs, there was an increase in mean blood pressure (138%) 3 h after volume expansion. This was thought to result from an increase in the total peripheral resistance (133%) associated with the recovery of cardiac output (106%). The pressor response to norepinephrine (0.5 microgram/kg) was potentiated after volume expansion. These results indicate that the handling of volume by the kidney contributed to the maintenance of an elevated level of cardiac output. However, nephrectomy did not seem to interfere with the hemodynamic switching of the causative factor for blood pressure elevation from increased cardiac output to increased total peripheral resistance. Neither was the potentiation of pressor response to norepinephrine affected.     

Interleukin-1 inhibits the secretion of gastric acid in rats: possible involvement of prostaglandin

To examine the hypothesis that interleukin-1 may inhibit the secretion of gastric acid, the present study was carried out using pylorusligated rats. Based upon three lines of evidence, we report here that interleukin-1, both endogenously released and exogenously administered, suppresses gastric acid secretion and that the interleukin-1-induced inhibition of acid output is possibly mediated by prostaglandin. First, lipopolysaccharide, a potent stimulant of the release and production of endogenous interleukin-1, caused the suppression of gastric acid, and this response was dose-related. Second, the intraperitoneal injection of interleukin-1 resulted in a dose-related inhibition of gastric acid output. Third, the administration of indomethacin completely blocked the suppression of gastric acid secretion induced by interleukin-1. These results demonstrated for the first time that IL-1 might be involved in the regulation of gastric secretion.     

Cloning and sequencing of a ligninase gene from a lignindegrading basidiomycete,Phanerochaete chrysosporium

Summary A ligninase gene has been cloned from a Phanerochaete chrysosporium genomic DNA library. Nucleotide sequencing of the gene has revealed that the ligninase structural gene contains 1116 bp of the protein-encoding sequence, of which 84 bp encode the signal peptide. The protein-encoding sequence is interrupted by eight introns which conform to the universal G-T/A-G splicing rule observed for the 3 and 5 intron boundaries. The putative eukaryotic regulatory sequences, i.e. CAAT and TATA box-like sequences, are present in the 5 flanking region.     

A male-specific renal cytochrome P-450 isozyme(s) responsible for mutagenic activation of 3-methoxy-4-aminoazobenzene in mice

Renal microsomes from male mice (BALB/c, DBA/2 and BALB/c x DBA/2 F1) showed about 10-fold greater activity for mediating mutagenic activation of 3-methoxy-4-aminoazobenzene (3-MeO-AAB) toward Salmonella typhimurium TA98 than did the corresponding hepatic microsomes, as compared on the basis of nmol of microsomal cytochrome P-450. On the other hand, female renal microsomes and other extrahepatic microsomes (lung, small intestine and colon) in both sexes of mice showed little or no activity for converting 3-MeO-AAB to mutagen(s). The mutagenic activation of 3-MeO-AAB with the male renal enzyme(s) was definitely inhibited by cytochrome P-450 inhibitors, 7,8-benzoflavone and SKF 525A. All these findings suggest that in mice, there is a male-specific renal 3-MeO-AAB activation enzyme(s), a cytochrome P-450 isozyme(s), which is different, at least in proportion and/or in nature, from hepatic cytochrome P-450 isozymes.     

An attempt to differentiate further between microglia and fluorescent granular perithelial (FGP) cells by their capacity to incorporate exogenous protein

It seems established that under pathological conditions, microglia and blood monocytes (invading the cerebral parenchyma) behave as histiocytic cells in the central nervous system. However, it has not been clear whether or not phagocytic cells are present in normal cerebral tissue. Recently, we found a new type of cell having an uptake capacity for exogenous substance at the bifurcations of small cerebral vessels except for capillaries. According to Imamoto et al. (1982), ameboid microglia, a kind of precursor of microglia, appear at a perinatal stage and can incorporate exogenous material. In the present paper, the developmental sequences of ameboid microglia and the unique cells laden with fluorescent granules are compared at a light and electron-microscopic level. From this study, it is clear that ameboid microglia are already present in the corpus callosum at 5 days after birth and are potent in their uptake capacity for horseradish peroxidase (HRP). However, at 2 weeks, they transform into star cells and the capacity for incorporation diminishes markedly. The finding is also supported by the quantitative analysis of transformation of ameboid microglia. At 3 months, glial cells do not take the administered HRP under the present conditions. On the other hand, fluorescent granular perithelial (FGP) cells arise from a leptomeningeal tissue (pia mater) and become situated in the perivascular spaces. They are not clearly defined at 5 days, and their uptake capacity for HRP has not yet developed. At 2 weeks, the FGP cells take definite forms with several inclusion bodies, and their uptake capacity for HRP attains a certain degree. Often, they are located at bifurcations of small blood vessels. At 3 months, the FGP cells differentiate completely in appearance, and their pinocytotic capacity reaches a high level. Consequently, the FGP cells belong to a different type of cell from that of ameboid microglia in their developmental sequences and assume a principal role of scavenging waste products in normal cerebral tissue.     

Differentiation of germ cells in seminiferous tubules transplanted to testes of germ cell-deficient mice of W/Wv and Sl/Sld genotypes

(WB X C57BL/6)F1-W/Wv (hereafter, WBB6F1-W/Wv) mice and (WC X C57BL/6)F1-Sl/Sld (hereafter, WCB6F1-Sl/Sld) mice are sterile due to the deficient spermatogenesis in the testes. The cause of deficient spermatogenesis in WBB6F1-W/Wv mice is considered to be a defect in germ cells themselves, whereas that in WCB6F1-Sl/Sld mice is considered to be a defect in tissue environment necessary for differentiation of germ cells. Seminiferous tubules isolated from cryptorchid testes of C57BL/6- +/+ mice were transplanted into the testes of WBB6F1-W/Wv and WCB6F1-Sl/Sld mice to clarify that the extratubular environment of these mice was intact or not. Type A spermatogonia in the transplanted tubules normally differentiated into spermatids, suggesting that the extratubular environment is intact in both WBB6F1-W/Wv and WCB6F1-Sl/Sld mice.     

Human high-affinity FcγRI (CD64) gene mapped to chromosome 1q21.2-q21.3 by fluorescence in situ hybridization

The human FcRI gene encodes for a highaffinity Fc receptor that plays pivotal roles in the immune response. We have used fluorescence in situ hybridization analysis to localize the FcRI gene to human chromosome 1. The human FcRI (CD64) gene has been assigned to human chromosome 1q21.2-q21.3 using R-banded human (pro)metaphase chromosomes.     

Partial purification and property of pyridoxine (pyridoxamine)-5′-phosphate oxidase isozymes from wheat seedlings

Isozymes of pyridoxine (pyridoxamine)-5′-phosphate oxidase (EC 1.4.3.5) were isolated from the extract of wheat seedlings by column chromatographies. From DEAE-Sephadex A-50, two fractions having pyridoxine-5′-phosphate oxidase activity were separated by eluting with ~0.075 and ~0.125 m phosphate buffers (pH 8.0). These fractions were further fractionated on a Blue-Sepharose CL-6B column, from which again two activities were eluted by 1.0 m KCl solution. One fraction, designated as E-I, used only pyridoxine 5′-phosphate as substrate, whereas the other, designated as E-II, oxidized not only pyridoxine 5′-phosphate but also pyridoxamine 5′-phosphate with approximately equal rates. The mobility on polyacrylamide disc gel electrophoresis and the substrate specificity of these two fractions were different. Therefore, they were concluded to be isozymes.