Inherited hydrocephalus in Csk: Wistar-Imamichi rats; Hyd strain: a new disease model for hydrocephalus

Hydrocephalic rats were found in a breeding colony of Csk: Wistar-Imamichi strain rats. In males, the hydrocephalus were serious and could be detected from 7 days after birth. Survival was 3-4 weeks. In females, the hydrocephalus was moderate, there was no abnormal external appearance, and the rats were able to mature. Ventricular dilatation was excessive in males but moderate in females. The total frequency of hydrocephalus was 34.3% in both males and females. Breeding data indicated that this disease is heritable and is single dominant and X-linked (symbol, Hyd). The female moderate hydrocephalics could be detected by progeny tests without examining brain sections. No evidence of developmental anomaly was observed in the ventricles. This hydrocephalus was classified as being of the communicating type, and this strain was named the Hyd strain as an animal model for human hydrocephalus.     

A method for detecting the optimum day for mating during the 4-day estrous cycle in the rat; measuring the value of electrical impedance of the vagina

A method for detecting the optimum day for mating in the rat was investigated. Cyclic changes of electrical impedance of vagina (EIV) were studied in the rats. EIV indicated high value (over 3,000 omega) only at proestrus, and it was lower (under 3,000 omega) at other stage of estrous cycle. These results apparently indicate that measuring the EIV made to distinguish proestrus from other phases of estrous cycle. The female caged with male showed high copulation rate (88 approximately 96%) when her EIV had been over 3,000 omega.     

Transfer of granulomatous inflammation with nonviable preparations of schistosome granulomas in naive mice

Hepatic granulomas of euthymic (nu/+) mice infected with Schistosoma mansoni were freeze-dried or freeze-thawed 3 times and transplanted subcutaneously into naive nu/+ and athymic (nu/nu) mice. The grafted sites, studied histologically, showed formation of organized granulomas in nu/+ mice similar to donor granulomas as observed after grafting of freshly isolated granulomas. On the other hand, in nu/nu mice, the nonviable transplants elicited small and disorganized granulomas, like hepatic granulomas in nu/nu mice with schistosomiasis, but different from fresh nu/+ transplants in nu/nu skin. The findings indicate viable cells are not required for transfer of granulomatous reactions, but T cells are needed for full expression.     

L-Histidinol phosphate aminotransferase from Salmonella typhimurium. Kinetic behavior and sequence at the pyridoxal-P binding site

A coupled assay with alpha-hydroxyglutarate dehydrogenase was used to analyze the kinetic behavior of histidinol phosphate aminotransferase from Salmonella typhymurium. Data obtained from studies of initial velocity, inhibition by products or substrate analogues, isotope exchange rates, and the determination of the equilibrium constant were consistent only with a Ping-Pong Bi Bi mechanism. Variations in inhibition patterns by different substrate analogues indicate that the microenvironment about the pyridoxal phosphate and the pyridoxamine phosphate forms of histidinol phosphate amino-transferase are different, and favor the presence of one active site with partially overlapping substrate-binding subsites for these 2 forms of the enzyme. Histidinol phosphate aminotransferase also catalyzes decomposition of beta-chloro-L-alanine to pyruvate, NH3 and Cl-; no transamination of this substrate occurs and inactivation of the enzyme accompanies this reaction. After reduction of histidinol-P aminotransferase with [3H]NaBH4, carboxymethylation, and tryptic digestion, one major radioactive peptide absorbing at 325 nm was isolated. Its primary structure was determined to be TLSK*AFALAGLR, where K* is the P-pyridoxyllysine residue. Although this peptide is only 30-40% homologous with the corresponding segment reported for other transaminases, all of these peptides are similar in placement of an hydroxyamino acid residue three residues upstream from the lysine residue, and in the cluster of hydrophobic amino acid residues immediately following the lysine residue.     

Macrophage chemotactic factor (MCF) produced by a human T cell hybridoma clone

A human T cell hybridoma clone, D6-18, producing high levels of macrophage chemotactic factor (MCF) was established by the emetine-actinomycin D selection method. MCF was found to be present not only in the culture medium but also in the cell lysate of D6-18 cells. The secretion of the MCF from D6-18 cells was effectively inhibited by disodium cromoglycate, which is an inhibitor of the degranulation of mast cells, suggesting that MCF is stored in granules. The MCF of D6-18 cells was purified from the sonicated cell lysate by ion-exchange chromatographies and high-performance liquid chromatography. The amino acid sequence of the purified MCF was revealed to be WLGREDGSE or WLGRQDGSE. The synthetic peptide WLGREDGSE showed chemotactic activity against guinea pig macrophages and human monocytes at the concentration of about 10(-8) M.     

Proteinic prorenin-releasing-stimulator (PRS) in the rat submandibular gland

The release of prorenin as well as renin from rat renal slices was confirmed by a rat prorenin-prosegment ELISA system and an assay system for determining the renin activity. A significant increase of the prorenin release was found by adding rat submandibular gland extract to the slice medium, indicating the existence of a prorenin-releasing stimulator (PRS) in the extract. The pI and molecular mass of PRS were 8.5-8.7 and 28-30 kDa, respectively. The PRS was completely inactivated by boiling or a proteinase treatment.     

Relationship between general or specific immunoreactivity and prognosis in postoperative patients with hepatocellular carcinoma

Summary The levels of a variety of immunological parameters were examined in 203 preoperative patients with hepatocellular carcinoma (HCC) at various stages (I–IV). The changes in the peripheral blood lymphocyte (PBL) count, the serum level of immunosuppressive acidic protein and the degree of the skin reaction to purified protein derivative were associated significantly with the stage of HCC progression. However, the percentages of lymphocyte subsets, mitogenic responsiveness of PBL and serum immunoglobulin concentration remained at the levels of stage I. Further study demonstrated that in patients undergoing hepatic artery ligation, there were statistically significant correlations between the PBL count, immunosuppressive acidic protein concentration and intensity of the skin reaction to purified protein derivative, assayed 1 month after surgery, and the prognosis. HCC-specific immunity was examined in 34 patients treated by hepatic resection or hepatic artery ligation using in vitro responses of PBL to HCC extracts (ATS test). This test was performed using culture medium containing added arginine. None of the PBL from the patients showed a positive response to allogeneic HCC extracts, but the PBL from 12 patients (9 hepatic resections, 3 hepatic artery ligations) were stimulated significantly (SI 2.5) with autologous HCC extracts. In 7 of 9 hepatic resection patients who were positive in the ATS test, tumor recurrence was identified. Statistical analysis indicated that the ATS test result was significantly correlated with tumor recurrence in hepatic resection patients. Autologous-PBL-stimulating activities were isolated in a fraction at pH 8.3 and in fractions at pH 6.7–7.0 by chromatofocusing of the crude extract. Although identification of the HCC-specific antigen remains to be done, use of the above fractions may simplify the ATS test procedure and improve its sensitivity.     

Localization of cytochrome P-450 in the colonic mucosa of 3-methylcholanthrene-pretreated and untreated rats An immunohistochemical study

Summary Immunohistochemical localization of cytochrome P-450 in the colonic mucosa of 3-methylcholanthrene-pretreated and untreated rats was studied by indirect fluorescent antibody staining technique. A polyclonal antibody for cytochrome P-450_MC purified from hepatic microsomes of 3-methylcholanthrene-pretreated rats was used for this experiment. A strong immunofluorescence was found to be localized in the cytoplasm of the surface epithelium of the mucosa in the colon of 3-methylcholanthrene-pretreated rats. A faint immunofluorescence was also observed in the epithelium of untreated rats. 7-Ethoxycoumarin O-deethylase activity of colonic microsomes was significantly enhanced by 3-methylcholanthrene-pretreatment in parallel with an increase in the intensity of immunostaining for cytochrome P-450_MC in Western blotting analysis. This is the first report on the localization of cytochrome P-450 in the colonic mucosa.     

Biochemical switching device realizing McCulloch-Pitts type equation

We analyzed cyclic enzyme systems, one of the best candidates for biochemical switching devices, especially focusing on their control mode against external perturbations. Since these systems have the reliability of ON-OFF types of operation (McCulloch-Pitts' neuronic equation), we shall present here the mechanical difference between these systems and electronic switching circuit, especially on the mnemonic mechanism of biochemical switching devices.