Free amino acid changes in the cerebral cortex of experimental uremic rat

The levels of free amino acids in the cerebral cortex of acute and chronic uremic rats were examined. Amino acids significantly elevated were aspartate, glutamine, glycine, histidine, ornithine, phenylalanine, phosphoethanolamine and taurine, whereas 1-methyl histidine and 3-methyl histidine were specifically detected in uremic rats. Glutamate, arginine and carnosine disclosed a significant reduction. There was no change in the concentrations of γ-aminobutyrate and alanine. The above findings were essentially identical in both acute and chronic uremia. It was conjectured that these changes of amino acid levels in the brain might participate in the progress of uremic encephalopathy.     

Isolation and characterization of plasma membrane from lactating bovine mammary gland

Plasma membranes were isolated from lactating bovine mammary gland. Two crude membrane fractions; medium/d 1.033 (light membrane) and 1.033/1.053 interfaces (heavy membrane), were obtained by Ficoll density gradient centrifugation of osmotically washed microsomal fraction. Two crude membranes were further purified separately by sucrose density gradient centrifugation. Both light and heavy membranes banded at a sucrose density of 1.14. The purified membranes appeared as heterogeneous smooth membrane vesicles on electron microscopy. The contaminating suborganelles were not detected. The yield of the purified membranes relative to the homogenate was 1.2%. The degree of purity of the membranes was shown by a great increase in the specific activity of 5′-nucleotidase over the homogenate of 20-fold for light membrane and of 16-fold for heavy membrane. The relative activities of Mg²⁺-ATPase, (Na⁺ + K⁺)-ATPase, γ-glutamyl transpeptidase, phosphodiesterase I, akaline phosphatase and xanthine oxidase were also high (12–18-times) and nearly 20% of these enzymes was recovered. The activity of marker enzyme for mitochondria, endoplasmic reticulum and Golgi apparatus was very low, while that of acid phosphatase for lysosome was relatively high (5-times). DNA and RNA contents were very low. The major polypeptides rich in other suborganelles were not detected profoundly in the membrane fraction and the polypeptide compositions in both light and heavy membranes were similar upon SDS-polyacrylamide gel electrophoresis.     

Production of itaconic acid by Aspergillus terreus immobilized in polyacrylamide gels

Summary Living Aspergillus terreus cells were entrapped in polyacrylamide gels and employed in both replacement batch and continuous column reactors to produce itaconic acid from glucose.With the replacement batch reactor, maximum itaconic acid productivity was observed under the following conditions: pH 2.50, temperature at 35°C, addition of NH₄H₂PO₄ and MgSO₄·7H₂O. Using the continuous reactor, the maximum itaconic acid yield was 60 mg/h/40 g of gel. The biocatalyst activity or half-life was about 10 days.     

Early Determination of Developmental Fate in Presumptive Intestinal Endoderm of the Chicken Embryo

The endodermal epithelia of esophagus, proventriculus and gizzard of 6-day chicken embryos can form glands and express embryonic chicken pepsinogen (ECPg), when they are subjected to the influence of proventricular mesenchyme, while intestinal epithelium of the same age cannot respond to the inductive influence of proventricular mesenchyme. We attempted in this paper to know whether this regional difference of epithelia to respond to mesenchymal influence originates very early in development or it is established gradually in the course of development of digestive tract.
The young presumptive intestinal endoderm taken from embryos having 15–20 somites was associated and cultivated with 6-day proventricular mesenchyme. The presumptive intestinal endoderm never expressed ECPg although it formed gland-like structures. In the control explants composed of presumptive stomach endoderm and proventricular mesenchyme, glands were formed and gland cells expressed ECPg detected by immunocytochemistry and in situ hybridization.
These results indicate that the developmental fate of presumptive intestinal endoderm is determined rather strictly at very early developmental stage, and suggest that the segregation of at least two cell lineages occurs early in the development; one which can express ECPg under the influence of proventricular mesenchyme, and another one which cannot express ECPg and differentiates mainly into intestinal epithelium.     

New records of within-group infanticide and cannibalism in wild chimpanzees

Two cases of within-group infanticide and cannibalism were observed among the M Group chimpanzees of the Mahale Mountains, Tanzania. In both cases, victimized infants were male, 5 – 6 months of age, and in good health when killed. Four to five years have passed since the mothers of the victims immigrated into M Group as nulliparous immigrants. In one case the 2nd-ranking male was observed to detach the infant from the mother's belly. Both infants were finally killed by the alpha male after several adult males scrambled for the bodies. There was no evidence that the mothers had mated with males other than those of M Group. Nor was there evidence that the mothers had restrictive mating relationships with some of the M Group adult males. What little evidence is available shows that the mothers had mated mostly with adolescent and other immature males during their conception cycles. However, at least in one case, the mother began to mate more with adult males rather than with immature males after the infanticide. It is proposed that the function of within-group male infanticide can be explained by the male-male competition hypothesis developed for hanuman langurs and other nonhuman primates.     

Squamous cell carcinoma antigen is a new member of the serine protease inhibitors

We have cloned cDNA of squamous cell carcinoma antigen. Sequence analysis of the complete 1711 basepairs SCC antigen cDNA revealed that it coded 390 amino acids and no typical signal sequence in the NH2-terminus. Northern blot analysis of human squamous cell poly(A)+ RNA using this cDNA insert as the probe showed a single RNA species of about 1.7 kilobases. The cDNA was expressed in Escherichia coli and the product was detected by immunological methods using antibodies against SCC antigen, indicating that this cDNA encodes the entire SCC antigen sequence. The amino acid homology search revealed that SCC antigen was a member of the serine protease inhibitors family.     

INTERACTIONS BETWEEN KURIL SEALS AND SALMON TRAP NET FISHERY IN THE COASTAL WATERS OF SOUTHEASTERN HOKKAIDO

An annual average of 163 Kuril seals was found dead in two years in salmon trap nets along the coastal waters of the Nemuro Peninsula and adjacent areas. The seal-caused damage to the total salmon catch at the salmon trap nets was concentrated in some of them, particularly No. 27, where seals killed or injured 5.1% of the catch in 1982, and 1.8% in 1983. Based on the proportion of Kuril seals among the dead seals in the trap nets, it was estimated that Kuril seals damaged 4.7% of the total salmon catch at No. 27 in 1982, and 1.7% in 1983. Not all seals that entered the trap net drowned; some killed or damaged salmon, and then escaped.     

The augmentative effect of a protein-bound polysaccharide (PSK) on tumoricidal activity of the soluble factor produced by a streptococcal preparation (OK-432)-activated macrophages

The enhancement of antitumor activities of the tumoricidal soluble factor (SF) from a streptococcal preparation (OK-432)-activated macrophages by the pretreatment with a protein-bound polysaccharide (PSK) was investigated in tumor-bearing mice.Two-step stimulations with OK-432 atin vivo priming andin vitro eliciting were required for the production of the tumoricidal SF by macrophages, and the tumoricidal activity of the SF apparently correlated with the uptake of OK-432 by macrophages at priming phase.Tumoricidal activity of the SF from OK-432-activated macrophages in proteose-peptone (P-P)-pretreated mice significantly decreased with the development of the tumor, whereas in PSK-pretreated mice did not. Pretreatment of tumor-bearing mice with PSK saved a decrease in the macrophages carrying Ia^k or asialo GM1 antigens and an increase in wheat germ agglutinin (WGA) receptors. Furthermore, the uptake of OK-432 by macrophages at priming phase was enhanced. The tumoricidal activity of the SF from OK-432-activated macrophages was augmented.Thus, PSK may restore the depressed functions of macrophages, and the combination therapy with PSK and OK-432 may be effective to enhance the production of tumoricidal SF in tumor-bearing mice.     

A novel TIMP-insensitive type IV collagen-degrading metalloproteinase from murine metastatic sarcoma cells

A novel type IV collagen-degrading metalloproteinase was purified from the conditioned media of a murine metastatic sarcoma cell line. The molecular weight of the purified enzyme was determined to be 100 kDa by SDS-PAGE, while 700 kDa by gel filtration suggesting that the enzyme has a multimer structure. This enzyme degrades type IV collagen, but neither type I collagen nor casein. The failure of trypsin treatment to enhance the enzyme activity suggested that the purified enzyme did not require activation. Although the enzyme seems to be classified as a matrix metalloproteinase, it was inhibited by neither tissue inhibitor of metalloproteinases (TIMP) nor TIMP-2 and thus represents a novel type IV collagen-degrading metalloproteinase.