Helicobacter pylori seropositivity in patients with severe neurologic impairment.

The objective of this study was to assess the prevalence of Helicobacter pylori seropositivity in institutionalized patients with severe neurologic impairment. Anti-H. pylori immunoglobulin G antibody in serum was measured in 196 institutionalized Japanese patients using enzyme linked immunosorbent assay, taking an antibody level >50 units/ml as evidence of H. pylori seropositivity. Patient age pattern and duration of institutionalization were examined for the relationships with H. pylori seropositivity. We also examined for seroconversion indicating new H. pylori infection in initially negative patients 1 year later. Positivity for H pylori infection among institutionalized patients was also compared with positivity among patients living at home. H. pylori seropositivity was present in 81.1% of subjects. Prevalence of H. pylori seropositivity increased with both age and duration of institutionalization. The serum level of anti-H. pylori immunoglobulin G antibody in patients over 20 years old was consistently high, approximately twice that of subjects less than 10 years of age. Of 38 patients initially negative for H. pylori infection, 18 (47.4%) had become positive at 1 year. H. pylori seropositivity was significantly more prevalent among institutionalized patients than among patients living at home (P < 0.0001). This study confirms that high H. pylori seropositivity rates are found among institutionalized patients with severe neurologic impairment. Our observations suggest person to person transmission, with fecal to oral, salivary secretion and respiratory droplet routes possibly being important pathways.

Zinc status relates to hematological deficits in middle-aged women.

OBJECTIVE: The objective of our study was to investigate zinc (Zn) status and the effects of Zn supplementation in relation to iron deficiency anemia in middle-aged women. It is important to define the role of Zn in hematologic abnormalities and to determine the frequency of Zn deficiency. METHODS: Fifty-two Japanese women, selected from a health examination survey on 6200 women, had hemoglobin concentrations below 12.0 g/dl, total iron binding capacity (TIBC) below 390 micrograms/dl and fairly normocytemia. These 52 were divided into three groups and we then compared the hematological status before and after iron (group A) or Zn (group B) or iron plus Zn (group C) supplementation. RESULTS: After treatment, concentrations of hemoglobin (Hb) increased slightly in groups A and B, but not statistically significant. In group C, Hb levels were significantly increased from 10.8 +/- 1.1 to 12.8 +/- 1.1 g/dl. Furthermore, numbers of RBC and reticulocytes, and concentrations of albumin were also increased significantly. Increased values over 1.0 g/dl of hemoglobin levels were noted in four women (26.6%) in group A, three women (14.2%) in group B and 13 women (81.2%) in group C. CONCLUSION: Zn status to some extent can account for hematological abnormalities in middle-aged women. At least 5.0% of middle-aged Japanese women may have Zn deficiency. Normocytic anemia with low TIBC levels may serve as a good indicator of a marginal Zn deficiency.

Rat argininosuccinate lyase promoter: the dyad-symmetric CCAAT box sequence CCAATTGG in the promoter is recognized by NF-Y.

The gene for rat argininosuccinate lyase (AL), which catalyzes the last step of arginine biosynthesis, is expressed in many tissues, though its expression is much higher in the liver where the enzyme is involved in the ornithine cycle (urea cycle), and moderately higher in the kidney. In transient transfection analysis using various cell lines, the AL promoter exhibited considerable levels of activity in all tested cell lines, with no apparent liver cell specificity, presumably reflecting the ubiquitous expression of this gene. Analysis of 5'-deletion mutants of the promoter region revealed several cis-regulatory elements, whose contribution to the promoter activity seemed to vary according to cell type. The most prominent positive regulatory region was detected around the position -80 base pairs, and it overlapped with a dyad-symmetric CCAAT box sequence CCAATTGG. A factor(s) interacting with this sequence element was found to be present ubiquitously. Gel shift competition analysis and antibody double shift analysis showed that this factor was identical or highly similar to a transcription factor, nuclear factor-Y (NF-Y), which consists of two different subunits and recognizes CCAAT motifs in various promoters. Point mutagenesis at each half site of the palindrome CCAATTGG and the introduction of a space between the half-site motifs abolished the binding with NF-Y. Thus, it seems that NF-Y recognizes the correctly spaced dyad-symmetric CCAAT box.

[Molecular basis of urea cycle disorders].

Five different enzymes, carbamyl phosphate synthetase I (CPS I), ornithine transcarbamylase (OTC) argininosuccinate synthetase (AS), argininosuccinate lyase (AL) and arginase (AR) play a role in urea synthesis from ammonium. The structures of cDNA of all these enzymes and those of genome DNA of some enzymes (OTC, AL, AR) have been already clarified, and using of the information, the alleles of each enzyme deficiency have been identified. Alleles are extremely heterogeneous in all enzyme deficiencies, in sharp difference from other inborn errors of metabolism, such as cystic fibrosis and hemoglobinopathies.

Expression of the chicken 'delta 2-crystallin' gene in mouse cells: evidence for encoding of argininosuccinate lyase.

In the chicken genome, downstream from the delta 1 gene, encoding delta-crystallin, a highly homologous gene called delta 2 is found, but neither its expression nor its function has been clarified. Close similarity of the delta 2 gene to mammalian argininosuccinate lyase (ASL)-encoding genes in organization and deduced amino acid sequence of the encoded protein suggested that this gene may encode chicken ASL. To test this possibility, we cloned the delta 2 gene on a plasmid, introduced it into mouse cells, and assessed expression and ASL activity in comparison with delta 1. We found that delta 2 was expressed well in fibroblastic L cells, which resulted in synthesis of a protein with a size (50 kDa) and antigenicity very close to delta-crystallin, but it was repressed in lens cells in which expression of delta 1 was activated. Transfectant L cell lines expressing delta 2 exhibited significantly higher ASL activity than those without. We conclude that the delta 2 gene codes for chicken ASL, but has a tissue specificity distinct from delta 1 in its expression.

Molecular evolution from argininosuccinate lyase to delta-crystallin.

cDNA clones for rat argininosuccinate lyase, a urea cycle enzyme, were cloned and amino acid sequence of the enzyme was predicted. The rat enzyme is 54% identical with the yeast enzyme, which is involved in arginine biosynthesis, thereby indicating that this urea cycle enzyme evolved from the arginine biosynthetic enzyme. A striking similarity (64% identity) was found between amino acid sequences of rat argininosuccinate lyase and chicken delta-crystallin, a major structural protein of the eye lens. The gene for the rat argininosuccinate lyase was cloned and its structure was determined. This gene is a single-copy gene about 14 kilobases long and is split into 16 exons. A comparison with chicken delta-crystallin genes revealed that all introns interrupt the protein-coding regions at homologous positions. This close similarity in structural organization provides strong evidence for the view that the chicken delta 1- and delta 2-crystallin genes evolved by recruitment and duplication of the preexisting argininosuccinate lyase gene and that delta 2-crystallin is probably the direct homologue of argininosuccinate lyase.

Evolutionary aspects of urea cycle enzyme genes.

The functions and expression pattern of urea cycle enzymes have undergone considerable changes during the course of evolution. Sequence analyses shows that urea cycle enzymes from mammals are homologous to microbial enzymes of the arginine-metabolic pathway. Recently, an unexpected relationship was found between argininosuccinate lyase (EC 4.3.2.1), the fourth enzyme of the cycle, and delta-crystallin, a lens structural protein of birds and reptiles.

Structure of the rat argininosuccinate lyase gene: close similarity to chicken delta-crystallin genes.

Argininosuccinate lyase (EC 4.3.2.1) is an enzyme of arginine biosynthesis and is also involved in the urea cycle in the liver of ureotelic animals. A comparison of cDNA-derived amino acid sequences revealed that argininosuccinate lyase is highly homologous with chicken delta-crystallin, a major structural protein of the eye lens. The gene for the rat argininosuccinate lyase was cloned and its structure was determined. This gene is a single-copy gene about 14 kilobases long and is split into 16 exons. A comparison with chicken delta-crystallin genes revealed that all introns interrupt the protein-coding regions at homologous positions. This close similarity in structural organization provides strong evidence for the view of Piatigorsky et al. [Piatigorsky, J., O'Brien, W. E., Norman, B. L., Kalmuck, K., Wistow, G., Borras, T., Nickerson, J. M. & Wawrousek, E. F. (1988) Proc. Natl. Acad. Sci. USA 85, 3479-3483] that chicken delta 1- and delta 2-crystallin genes evolved by recruitment and duplication of the preexisting argininosuccinate lyase gene and that delta 2-crystallin is probably the direct homologue argininosuccinate lyase.

Amino acid sequence of rat argininosuccinate lyase deduced from cDNA.

Argininosuccinate lyase [EC 4.3.2.1] is an enzyme of the urea cycle in the liver of ureotelic animals. The enzymes of the urea cycle, including argininosuccinate lyase, are regulated developmentally and in response to dietary and hormonal changes, in a coordinated manner. The nucleotide sequence of rat argininosuccinate lyase cDNA, which was isolated previously (Amaya, Y., Kawamoto, S., Oda, T., Kuzumi, T., Saheki, T., Kimula, S., & Mori, M. (1986) Biochem. Int. 13, 433-438), was determined. The cDNA clone contained an open reading frame encoding a polypeptide of 461 amino acid residues (predicted Mr = 51,549), a 5'-untranslated sequence of 150 bp, and a 3'-untranslated sequence of 41 bp. The amino acid composition of rat liver argininosuccinate lyase predicted from the cDNA sequence is in close agreement with that determined on the purified enzyme. The predicted amino acid sequences of the human and yeast enzymes along the entire sequences (94 and 39%, respectively), except for a region of 66 residues of the human enzyme near the COOH terminus. However, the sequence of this region of the human enzyme predicted from another reading frame of the human enzyme cDNA is homologous with the corresponding sequences of the rat and yeast enzymes. Therefore, the human sequence should be re-examined. Lysine-51, the putative binding site for argininosuccinate, and the flanking sequences are highly conserved among the rat, steer, human, and yeast enzymes.

Carnitine prevents Reye-like syndrome in atypical carnitine deficiency.

A patient with repeated episodes of a Reye-like syndrome was studied. Serum and muscle carnitine levels were normal, but there was an apparent accumulation of muscle lipid and glycogen. Ragged-red fibers were present in the muscle. Prolonged fasting (20 hours) induced hypoglycemia, lactic acidosis, an increase in free fatty acids, and hyperammonemia. There was an accompanying sizeable reduction in the serum free carnitine level. Fasting with L-carnitine administration resulted in milder changes in these laboratory measures. Administration of L-carnitine, (100 mg/kg/day) led to clinical improvement as evidenced by fewer attacks and a normal Gowers sign.