PubMed HealthSearch

Biomedical subjects

M Hasebe

Publications and source records attributed to M Hasebe.

At least 19 recordsLinked to original sources

Vacuolar type H(+)-ATPase genes: presence of four genes including pseudogenes for the 16-kDa proteolipid subunit in the human genome.

Genes for the human vacuolar type H(+)-ATPase proteolipid (16-kDa) subunit were cloned and their nucleotide sequences were determined. Comparison of the deduced sequences indicated that at least four genes including pseudogenes are present in the human genome. One of them corresponded to that for the 16-kDa subunit expressed in HeLa cells. The coding sequence was separated by two introns. The second intron was located in the DNA segment giving a loop between the second and third transmembrane helices, supporting the idea that the 16-kDa subunit was evolved by gene duplication. The primary sequence determined from the second clone had a termination codon behind the third transmembrane helix. Possible translation products from the other two clones had no putative acidic residues essential for proton transport function of the 16-kDa subunit. Thus, it is interesting to know whether these genes are transcribed, since they may have unique cellular functions.

Base Sequence

Structural rearrangements of the chloroplast genome provide an important phylogenetic link in ferns.

The chloroplast genome of most land plants is highly conserved. In contrast, physical and gene mapping studies have revealed a highly rearranged chloroplast genome in species representing four families of ferns. In all four, there has been a rare duplication of the psbA gene and the order of the psbA, 16S, and 23S rRNA genes has been inverted. Our analysis shows that the described rearrangement results from a minimum of two inversions within the inverted repeat. This chloroplast DNA structure provides unambiguous evidence that phylogenetically links families of ferns once thought to belong to different major evolutionary lineages.

Chloroplasts

Alterations in levels of plasma phenylalanine and its catabolism in the liver of stressed rats.

This study examined the relationship between elevation of blood phenylalanine (Phe) concentrations often observed in trauma or infected patients without hepatic dysfunction and alterations of liver Phe catabolism. Rats underwent pathophysiologically different stresses, either sepsis or scald injury. The catalytic activity of hepatic Phe hydroxylase (PH) in the septic rats, as measured after preincubation with Phe, decreased to 60% of the control values; this in vitro result suggests a reduction of enzyme species activated by its substrate. Phe was degraded in the septic rats to a similar extent to that in controls, when measured by pulse administration of [1-14C]-Phe. In the scalded rats whose plasma Phe level showed a comparable but transient increase, no significant alterations occurred in Phe catabolism and enzyme activities. The changes in plasma glucagon and catecholamine levels were consistent with those of the enzyme activities involved in Phe and tyrosine (Tyr) catabolism in the stressed groups. These results indicate that inadequate activation of native PH by regulatory mechanisms involving Phe in vivo was also associated with the accumulation of plasma Phe in infected rats during massive mobilization of amino acids from muscles under conditions of enhanced and sustained catabolism.

Animals

Sporadic congenital transmission of avian leukosis virus in hens discharging the virus into the oviducts.

The efficacy of the albumen test for infectious avian leukosis virus (ALV) was examined in detecting congenitally transmitting hens. Seventy-three White Leghorn non-viremic hens with antibody to ALV were used. Eleven of the hens shed infectious ALV into their egg albumen, whereas only 7 of the 11 ALV-positive hens shed ALV antigens. The egg albumen test for infectious ALV was shown to be more effective in detecting the congenitally transmitting hens than that for ALV antigens. Then, twenty of the 62 hens which shed no infectious ALV into the albumen were studied for transmission of ALV to their embryos and for discharging ALV into the oviduct and vagina. Six of the 50 embryos from 4 hens were found to be infected with ALV but all of the 227 embryos from remaining 16 hens were free from the infection. Discharge of the virus into the oviduct and vagina was found both in the 4 transmitting hens and in 6 of the 16 non-transmitting hens. These results suggest that the hens discharging ALV into the oviduct, even though they do not shed ALV into egg albumen, may transmit the virus sporadically to their embryos.

Animals

Molecular cloning of cDNA encoding the 16 KDa subunit of vacuolar H(+)-ATPase from mouse cerebellum.

cDNA for the 16 kDa subunit of vacuolar H(+)-ATPase was cloned from mouse cerebellum and sequenced. The deduced polypeptide (155 amino acid residues; molecular weight, 15,808) was highly hydrophobic and homologous to the subunits of bovine adrenal medulla, Torpedo marmorata electric lobe, Drosophila and yeast. Glu-139 (supposed to be essential for proton transport) was also conserved as the potential dicyclohexylcarbodiimide binding site. The subunit had four transmembrane segments: Segment II and IV were highly homologous and Glu-139 was located in Segment IV. The roles of the non-conserved regions are discussed.

Adrenal Medulla

BHV-1 adsorption is mediated by the interaction of glycoprotein gIII with heparinlike moiety on the cell surface.

The gIII glycoprotein of bovid herpesvirus 1 (BHV-1) has been shown to mediate the adsorption of the virions to cells (K. Okazaki, E. Honda, T. Minetoma, and T. Kumagai, 1987, Arch. Virol. 97, 297-307). In this study, the cellular receptor for BHV-1 was investigated. Addition of heparin to the virus inoculum and treatment of the cells with heparinase prevented the virus from adsorbing to and infecting the cells. Of the major glycoproteins of BHV-1 only gIII was found to bind specifically to heparin. The binding of gIII was inhibited by a monoclonal antibody against antigenic site Ia, which interferes with the adsorption of the virus. These findings indicate that the virus adsorption to cells is mediated by interaction of the gIII antigenic site Ia with a heparinlike moiety on the cell surface, which serves as a receptor for BHV-1.

Adsorption

Identification and characterization of hens transmitting avian leukosis virus (ALV) to their embryos by ELISAs for detecting infectious ALV, ALV antigens and antibodies to ALV.

A total of 72 White Leghorn grandparent hens was examined by ELISA for avian leukosis virus (ALV), ALV antigens and anti-ALV antibodies to identify and characterize the hens transmitting ALV to their embryos (transmitters) by using fertilized eggs. These hens were divided into 3 groups as no antibody and non-viremic (NANV) (49 hens), antibody-positive and non-viremic (APNV) (21 hens) and no antibody and viremic (NAV) (2 hens) by testing the sera for the presence of ALV and anti-ALV antibody. Egg albumen and embryos were tested for the presence of ALV and ALV antigens. As a result, no ALV was detected in both albumen and embryos in the NANV group. On the other hand, all albumen samples collected repeatedly from 3 hens of the APNV group and 2 hens of the NAV group contained infectious ALV, although the infectivity differed with the individual. Also, these 5 hens produced infected embryos at varying frequencies. However, on AP hen which shed neither ALV nor ALV antigens into the albumen produced an infected embryo at a lower rate. These results indicate that testing for infectious ALV in albumen from a newly laid egg per hen is effective to identify the transmitters to some extent. When virus titers in each of 8 tissue samples from the 6 transmitting hens were determined, the highest virus titers were found in washing from the ampulla of the oviducts in most of the shedders, suggesting that embryo infection is closely correlated with ALV produced at the oviduct, but not with ALV transferred from the other parts of the body.

Animals

Long-term outcome of massive small bowel resection.

The long-term outcome for seven patients 4-17 yr (mean 7.1 yr) after massive small bowel resection, leaving 5-160 cm (mean 86.4) of small bowel, was reviewed. Their mean age at the final enterectomy was 40 yr. Adaptation to foodstuffs and the effects of physiologic alterations and complicating diseases on their return to work were emphasized. More than 3.5 yr after surgery, the patients had adapted to many kinds of foodstuffs, but dietary fat could not be tolerated by three patients. Six patients returned to work an average of 2.7 yr after surgery, but four were obliged to discontinue their work because of rehospitalization for long-term complications. In addition, their working hours were limited, and they could not engage in heavy physical work, owing to physiologic alterations, such as a reduced metabolic state, after massive enterectomy.

Adult

FlgB, FlgC, FlgF and FlgG. A family of structurally related proteins in the flagellar basal body of Salmonella typhimurium.

The flagellar basal body of Salmonella typhimurium consists of four rings surrounding a rod. The rod, which is believed to transmit motor rotation to the filament, is not well characterized in terms of its structure and composition. FlgG is known to lie within the distal portion of the rod, in the region where it is surrounded by the L and P rings, just before the rod-hook junction. The FlgC and FlgF proteins are also known to be flagellar basal-body components; by comparison of deduced and experimental N-terminal amino acid sequences we show here that FlgB is a basal-body protein. The flgB, flgC, flgF and flgG gene sequences and the deduced protein sequences are presented. The four proteins are clearly related to each other in primary sequence, especially toward the N and C termini, supporting the hypothesis (based on examination of basal-body subfractions) that FlgB, FlgC and FlgF are, like FlgG, rod proteins. From this and other information we suggest that the rod is the cell-proximal part of a segmented axial structure of the flagellum, with FlgB, FlgC and FlgF located (in unknown order) in successive segments of the proximal rod, followed by FlgG located in the distal rod; the axial structure then continues with the hook, HAPs and filament. Although the rod is external to the cell membrane, none of the four rod proteins contains a consensus signal sequence for the primary export pathway; comparison with the experimentally determined N-terminal amino acid sequence indicates that FlgB has had its N-terminal methionine removed, while the other three are not processed at all. This demonstrates that these proteins are not exported by the primary cellular pathway, and suggests that they are exported by the same flagellum-specific pathway as the flagellar filament protein flagellin. The observed sequence similarities among the rod proteins, especially a six-residue consensus motif about 30 residues in from the N terminus, may constitute a recognition signal for this pathway or they may reflect higher-order structural similarities within the rod.

Amino Acid Sequence

Effect of total parenteral nutrition enriched in branched-chain amino acids on metabolite levels in septic rats.

This study examined the effects of total parenteral nutrition (TPN) enriched with branched-chain amino acids (BCAAs) on metabolite levels of carbohydrate and protein metabolism in septic rats. Results also were obtained for standard amino acid hyperalimentation (conventional TPN). Septic peritonitis was induced in rats by cecal ligation and puncture. Two different experimental models were tested. In one, the two kinds of TPN were administered to the operated rats during the progress of sepsis (the septic phase). In the other, TPN was started immediately after surgical removal of the focal cecum (the recovery phase). The conventional and BCAA-enriched TPN solutions were isocaloric and isonitrogenous except that the percentage of BCAAs in the total amino acids by weight was 35.8% in BCAA-enriched TPN and 20.9% in conventional TPN. On the fifth postoperative day, TPN was discontinued, the animals were killed, and samples of arterial blood, liver, and rectus abdominis muscle were taken. BCAA-enriched TPN had a significant effect on nitrogen balance and survival rate in the septic phase model, and on muscle adenine nucleotide content in both models. Other metabolites showed similar changes in the two TPN groups. These results indicate that BCAA supplement in TPN improves nitrogen balance and peripheral cellular energy status and is thus clinically beneficial in preventive therapy for increased catabolism.

Amino Acids

[Metabolic and nutritional support in severely burned patients].

UNLABELLED: Proper metabolic and nutritional support is an important treatment modality in severely burned patients. We examined the effect of branched-chain amino acid (BCAA) enriched TPN on metabolism of burned rats. A scald injury (30% BSA) was produced in rats. The rats, after resuscitated with saline for 24 hr, were divided into 3 groups. CONTROL GROUP: received saline. Group B: received TPN with BCAA enriched solution (45% BCAA). Group C: received TPN with conventional amino acid solution (21.3% BCAA). Both of these TPN solutions were isocaloric and isonitrogenous. Rats of each group were administered TPN solution or saline for further 48 hr. The metabolites in the liver and muscle were measured. Rapid and marked decrease of levels of metabolites such as adenine nucleotides, glycogen, G-6-P, protein and RNA/DNA was observed in the liver and muscle of the rats during fluid resuscitation. The rats of group B showed significant recoveries in all of these parameters after administration of the TPN, as compared with those of group C. On the other hand, progressive metabolic deterioration was recognized in the rats of control group. These results indicate beneficial effects of BCAA enriched TPN on energy and protein metabolism in scald injury.

Amino Acids, Branched-Chain

Alterations in metabolite levels in carbohydrate and energy metabolism of rat in hemorrhagic shock and sepsis.

For comparison of the extent of metabolite content alteration caused by etiologically different types of shock, septic peritonitis and hemorrhagic shock (mean arterial blood pressure at 40 mm Hg for 1 h or 2 h) were produced in rats. Contents of metabolites were determined in the liver and the muscle. Characteristic differences were found in the alteration modes of hepatic lactate level, muscle adenine nucleotide concentrations, and muscle protein content between these shock models. Rapid and significant alterations were observed in the levels of adenine nucleotides, glucose-6-phosphate and lactate in the liver in both types of shock. Hepatic energy charge and contents of glycogen and protein also significantly decreased. On the other hand, noticeable changes in the muscles were elevation of lactate level and the decrease of phosphocreatine and protein concentrations. Another distinct change was the decrease of total adenine nucleotide content in the muscle of septic rats, whereas it remained unchanged in the muscle of hemorrhagic shock rats. Thus, the changes of metabolite levels did not occur simultaneously in different tissues, and their rate and magnitude varied between different types of shock. The difference in adaptive response of metabolism may result in pathophysiologic diversity in shock.

Adenine Nucleotides