Oxidative stress response in yeast: effect of glutathione on adaptation to hydrogen peroxide stress in Saccharomyces cerevisiae

Role of intracellular glutathione in the response of Saccharomyces cerevisiae to H2O2 was investigated. Depletion of cellular glutathione or inhibition of gamma-glutamylcysteine synthetase (GSH-I) enhanced the sensitivity to H2O2 and suppressed the adaptation to H2O2. A mutant deficient in GSH-I also showed the hypersensitivity and could not adapt to H2O2. Incubation of the cell with amino acids constituting glutathione (L-Glu, L-Cys, Gly) increased the intracellular glutathione content, and subsequently the cell acquired resistance against H2O2. These results strongly suggest that intracellular glutathione plays an important role in the adaptive response in S. cerevisiae to oxidative damage.

Brain tissue identification based on myosin heavy chain isoforms

Non-muscle tissues contain 3 myosin heavy chain (MHC) isoforms; MIIA, MIIB1 and MIIB2. MIIA is a non-muscle type isoform distributed in all non-muscle tissues and smooth-muscle, while MIIB1 and MIIB2 are brain-type isoforms distributed mainly in neuronal tissues. The ratio of MIIA and MIIB (A/B ratio) differs between tissues, suggesting that this ratio may be a useful marker for tissue identification. To apply the A/B ratio for tissue identification in forensic practice, we developed a highly sensitive ELISA for quantification of each MHC isoform. At least 100 pg of both MHC isoforms could be detected by the present method. Analysis of the A/B ratio of the cerebrum, cerebellum, liver, kidney, spleen and andrenal gland by the present method indicated that the A/B ratio of the brain tissue (< 0.5) was quite different from other tissues (> 3.0). The A/B ratio could be determined from at least 8 micrograms of fresh tissue sample and 0.1 mg of dried tissue sample stored for 1 month at room temperature. Therefore, the A/B ratio seems to be an excellent marker for identification of the brain tissue.

Platelet derived growth factor expression, myelofibrosis and chronic myelogenous leukemia

CML is often associated with myelofibrosis, and fibrosis in the accelerated phase is one of the diagnostic criteria for this accelerated phase. In this review, the mechanism of myelofibrosis associated with CML is discussed with emphasis on the cell origin of the production and release of platelet derived growth factor (PDGF) and its interaction with marrow fibroblasts. In the initial stage of myelofibrosis in chronic phase CML, atypical small megakaryocytes might leak PDGF, possibly PDGF-AB, together with other growth factors. As the clinical phase of the disease progresses to accelerated or blastic phase, a larger quantity of PDGF-AB or PDGF-BB might be secreted from blastic cells with myeloid phenotype. In addition some fibroblasts may be attracted by the PDGF and proliferate, and deposit collagen as well as fibronectin in the bone marrow stroma.

A myosin missense mutation, not a null allele, causes familial hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is characterized by myocardial hypertrophy of unknown etiology. Missense mutations of the cardiac beta-myosin-heavy-chain (beta-MHC) gene that may be responsible for cardiac hypertrophy have been detected in patients with HCM. On the other hand, gross structural abnormalities in the cardiac beta-MHC gene, ie, an alpha/beta hybrid gene and partial deletion of the gene, have also been reported. The direct correlation between gross abnormalities and development of HCM is not well understood.

METHODS AND RESULTS

We analyzed the structure of the cardiac beta-MHC gene from patients with HCM by using polymerase chain reaction-DNA conformation polymorphism analysis and found two sequence variations in exons 3 and 22 in one patient. These sequence variations at codon 54 (exon 3; nonsense mutation) and codon 870 (exon 22; Arg-to-His mutation) were identified by direct sequencing and dot-blot hybridization with allele-specific oligonucleotide probes. Relatives of this patient were examined for the mutations. It was revealed that the missense mutation was inherited from the affected father and the nonsense mutation from the unaffected grandmother through the unaffected mother. In addition, the missense mutation was also found in seven other patients from two other unrelated multiplex HCM families.

CONCLUSIONS

The Arg870His mutation was suggested to cause HCM. In contrast, the gene with the nonsense mutation would encode for a cardiac beta-MHC protein of only 53 amino acid residues, which may be too short to be incorporated into the thick filament assembly of cardiac myosin chains and showed no dominant phenotype of heart disease. This is the first report of a nonsense mutation in the human cardiac beta-MHC gene.

Effects of visual and auditory stimuli on median nerve somatosensory evoked potentials in man

To demonstrate electrophysiological evidence of neural connections of somatosensory with visual and auditory pathways, interactions of median nerve somatosensory evoked potentials (SEPs) with visual evoked potentials (VEPs) and auditory evoked potentials (AEPs) were analyzed in 12 healthy subjects. In Experiment I (SEP vs. VEP), three patterns of stimulation, namely, electric stimulation of left median nerve, binocular LED flash, and simultaneous electric and flash stimulation, were applied with random interstimulus intervals of 2-4 sec until more than 100 responses had been obtained and averaged for each pattern of stimulation. Simultaneous electric and visual responses were subtracted from arithmetical sums of SEPs and VEPs to show interactions between somatosensory and visual responses. In Experiment II (SEP vs. AEP), binaural short-duration tone bursis instead of LED flashes were used in the same manner as in Experiment I, and interactions between somatosensory and auditory responses were analyzed. Results indicated that the effects of both visual and auditory interaction on SEPs were significant around 120-130 msec of latency. In other words, cross-modal sensory interaction occurred in the late phase of sensory processing.

Somatocardiovascular reflexes in anesthetized rats with the central nervous system intact or acutely spinalized at the cervical level

The effects of noxious mechanical stimulation of various segmental areas on heart rate and mean arterial blood pressure (MAP), as well as cardiac and renal sympathetic nerve activities were examined in anesthetized rats with the central nervous system (CNS) intact or acutely spinalized at the cervical level. In CNS-intact rats, pinching for 20 s applied to any segmental skin area, but particularly that of the paw, produced an increase in heart rate, blood pressure and the sympathetic nerve activities. In acutely spinalized rats, pinching the chest, abdomen and back of the body produced large increases, while hindlimb and perineum stimulation induced only a small increase or no increase in heart rate, blood pressure and the sympathetic nerve activities. Stimulation of the right side produced particularly large responses in heart rate and stimulation of the ipsilateral side produced large responses in cardiac and renal sympathetic nerve activities in spinalized rats. These results suggest the existence of the two types of reflex responses, supraspinal and propriospinal, in the somatocardiovascular reflex. The supraspinal one has characteristics of diffuse reflex organization, while the propriospinal one has strong segmental and lateral organization.

Pedicled jejunal seromuscular flap for bronchocutaneous fistula

We report the successful closure of a complicated bronchocutaneous fistula using a pedicled jejunal flap. The fistula, secondary to tuberculosis and irradiation, previously had been closed with a latissimus dorsi musculocutaneous flap. This initial repair failed. The recurrent fistulas were closed again using a jejunal seromuscular flap, and the chest wall defect was reconstructed with a rectus abdominis musculocutaneous flap.

Characterization of T cell epitopes restricted by HLA-DP9 in streptococcal M12 protein

Interaction of the HLA-DP9 (DPA1*0201/DPB1*0901) molecule and M protein of serotype 12 (SS95/12) streptococci, a main component of the streptococcal cell wall Ag, has been investigated to decipher peptide-binding capacity and T cell activation in the context of the HLA-DP molecule. Seven antigenic peptides (amino acids 19-25) restricted by the HLA-DP9 molecule were identified in M12 protein, using M12 protein- or peptide-specific T cell lines from naturally exposed individuals. The binding affinity of each peptide to the HLA-DP9 molecule was measured by fluorescence intensity of biotinylated peptides bound to L cell transfectants expressing HLA-DP9, followed by treatment with avidin-fluorescence. Binding of biotinylated peptides to the HLA-DP9 molecule was inhibited by an excess amount of corresponding nonbiotinylated peptides and other nonbiotinylated peptides, indicating that the peptides were bound to the HLA-DP9 molecule at a single binding site. Seven synthetic peptides containing the T cell epitopes restricted by the HLA-DP9 molecule had high binding affinity to the HLA-DP9 molecule. Comparison of the amino acid sequences of truncated analogues that could bind to the HLA-DP9 molecule and/or activate T cells suggested an HLA-DP9-specific binding motif, composed of a positively charged residue (R or K) at position 1, a hydrophobic residue (A, G, or L) at position 6, and another hydrophobic residue (L or V) at position 9. Analysis of single amino acid-substituted analogues suggested that the positively charged amino acid in the motif served as a key anchor residue for binding to the HLA-DP9 molecule, which differs from the binding motif to the HLA-DR molecules.

Secretory carcinoma of the breast associated with juvenile papillomatosis in a 12-year-old girl. A case report

A rare case of juvenile secretory carcinoma (SC) associated with juvenile papillomatosis (JP) is described. Tumor biopsy and fine needle aspiration cytology (FNAC) were performed in a 12-year-old girl who had noticed a painful right breast mass. One of the two types of tumor cells found on FNAC smears formed mainly sheets or clusters, intercellular spaces within the sheets and intracytoplasmic vacuolation. These cells, a few of which had a signet-ring cell appearance with completely disordered and randomly arranged nuclei, were considered to be SC cells. Cells of the other type were found in scattered papillary clusters and had well-defined cytoplasmic borders, uniform cell and nuclear size, and an orderly nuclear arrangement, suggesting a benign papillary lesion. Histologic examination of the tumor biopsy and breast quadrantectomy specimens revealed SC with JP. The cytologic, histologic and electron microscopic features of SC are described, and the relationship between SC and JP is discussed.

Characterization of T cell epitopes restricted by HLA-DP9 in streptococcal M12 protein

Interaction of the HLA-DP9 (DPA1*0201/DPB1*0901) molecule and M protein of serotype 12 (SS95/12) streptococci, a main component of the streptococcal cell wall Ag, has been investigated to decipher peptide-binding capacity and T cell activation in the context of the HLA-DP molecule. Seven antigenic peptides (amino acids 19-25) restricted by the HLA-DP9 molecule were identified in M12 protein, using M12 protein- or peptide-specific T cell lines from naturally exposed individuals. The binding affinity of each peptide to the HLA-DP9 molecule was measured by fluorescence intensity of biotinylated peptides bound to L cell transfectants expressing HLA-DP9, followed by treatment with avidin-fluorescence. Binding of biotinylated peptides to the HLA-DP9 molecule was inhibited by an excess amount of corresponding nonbiotinylated peptides and other nonbiotinylated peptides, indicating that the peptides were bound to the HLA-DP9 molecule at a single binding site. Seven synthetic peptides containing the T cell epitopes restricted by the HLA-DP9 molecule had high binding affinity to the HLA-DP9 molecule. Comparison of the amino acid sequences of truncated analogues that could bind to the HLA-DP9 molecule and/or activate T cells suggested an HLA-DP9-specific binding motif, composed of a positively charged residue (R or K) at position 1, a hydrophobic residue (A, G, or L) at position 6, and another hydrophobic residue (L or V) at position 9. Analysis of single amino acid-substituted analogues suggested that the positively charged amino acid in the motif served as a key anchor residue for binding to the HLA-DP9 molecule, which differs from the binding motif to the HLA-DR molecules.

Early-onset pauciarticular juvenile chronic arthritis is associated with a mutation in the Y-box of the HLA-DQA1 promoter

Early-onset pauciarticular juvenile chronic arthritis (EOPA-JCA) has associations with different alleles of the MHC region (HLA-A2, DR5, 6, 8, DQA1*0401, *0501, *0601 and DPB1*0201). All susceptible DQA1 alleles carry an exclusive sequence motif. MHC-class II gene expression is controlled by 5' flanking upstream regulatory regions (URR). A hypervariable region in the promoter region of the HLA-DQA1 gene (-240 and -200 base pairs upstream) defines ten different QAP (DQA1-Promoter) alleles, which are associated with certain DQA1-alleles. The Y-Box in the DQA1 promoter (YC-Box -125 to -115 upstream from the ATG) differs from the consensus sequence (-123 A for G) of all other MHC class II Y-Boxes, resulting in a lower affinity to the NF-Y transcription factor and in a reduced expression of DQA1. A second substitution in the Y-Box of QAP 4.1 and 4.2 (-119 A for G) is found in the promoter alleles of the DQA1-alleles (DQA1*0401, *0501, *0601) and is strongly associated with susceptibility to EOPA-JCA.

Transient expression of a brain/embryonic-type myosin heavy chain isoform (MIIB2) in regenerating rat liver

The expressions of non-muscle-type (MIIA) and brain/embryonic-type (MIIB2) myosin heavy-chain isoforms in regenerating rat liver were examined. In regenerating liver after partial hepatectomy, the level of MIIA was nearly constant, while that of MIIB2 increased transiently. The level of MIIB2 was very low in normal livers, and increased gradually and then declined with a peak at the 4th day, when the regeneration was almost completed. The level of proliferating cell nuclear antigen was highest at the 2nd day. Serine dehydratase activity in the liver decreased on partial hepatectomy, began to increase at the 5th day, and reached 71% of the control at the 7th day. These results suggest that MIIB2 plays a role in reconstruction or differentiation of the regenerating tissues rather than in proliferation of hepatocytes.

Polymorphism in the upstream regulatory region of DQA1 gene in the Italian population

Polymorphism in the 5'-upstream regulatory region of the DQA1 gene has been recently described. Using PCR-SSO method and SSCP analysis we have investigated this polymorphism in a group of 111 Italian blood donors which had been oligotyped for DRB1, DQA1 and DQB1 genes. Eight allelic variants were detected. Looking at the relationships among QAP sequences and DQA1 and DRB1 genes, three alternative situations were found: 1. a one-to-one relation between QAP and DQA1 alleles, independently of the other class II genes; 2. the same QAP allele in association with different DQA1-DRB1 haplotypes; 3. the same DQA1 allele with different QAP sequences according to the DRB1 specificity. No unexpected associations with DQB1 gene were found. These results must be interpreted considering that DQA1 and DRB1 genes are transcribed in opposite directions so that the promoter region of DQA1 gene lies between DQA1 and DRB1, close to the former but several hundreds kb away from the latter.

[Measurement of bile acid N-acetylglucosaminides in serum and urine of patients with chronic liver diseases during ursodeoxycholic acid treatment]

Bile acid N-acetylglucosaminide (GlcNAc) was investigated in serum and urine of patients with chronic liver diseases during ursodeoxycholic acid (UDCA) treatment by HPLC. Bile acid N-acetylglucosaminide was not detected other than primary biliary cirrhosis in serum and urine. All of these N-acetyglucosaminide was ursodeoxycholic acid N-acetylglucosaminide (GlcNAc-UDCA). GlcNAc-UDCA excretion was 17.3 +/- 5.7 mg/day in PBC stage I, 12.1 +/- 5.4 mg/day in stage II, 39.1 +/- 20.8 mg/day in stage III. Among the GlcNAc fraction GlcNAc-UDCA-gly occupied greatest part followed by GlcNAc-UDCA-tau and non-amidated Glc-NAc-UDCA. GlcNAc-UDCA was 50.1% of total urinary bile acids excretion in PBC stage I, 32.5% in stage II, 20.5% in stage III. However, GlcNAc-UDCA was less than 2.5% of total serum bile acids in every stage. These results indicate that N-acetylglucosamine conjugation is one of the major pathway of UDCA in patient with primary biliary cirrhosis.

Chemical modification and amino acid sequence of active site in sugar beet alpha-glucosidase

The modification of amino acid residues in sugar beet alpha-glucosidase with conduritol B epoxide (CBE), an affinity labeling reagent, inactivated the enzyme. The inactivation followed pseudo-first-order kinetics. The enzyme was protected from inactivation by a competitive inhibitor, Tris, and the partially inactivated enzymes showed only the decrease of V values and no change in Km value. An 3H-CBE labeled peptide isolated from the digest of the inactivated enzyme with Lys-C protease was sequenced. The -COO- group of Asp was found to be specifically labeled, implicating that it is a catalytic group of the enzyme. The sequence around the essential Asp was determined to be -DGIWIDMNE-, which showed a high homology with those of other alpha-glucosidases.

Extensive polymorphism of a (CA)n microsatellite located in the HLA-DQA1/DQB1 class II region

A highly polymorphic (CA)n microsatellite marker (DQCAR), located between the DQA1 and the DQB1 genes, was characterized in four ethnic groups. Based on length polymorphism, 12 alleles could be defined. The marker is located 1- to 2-kb telomeric to the DQB1 gene and 10 kb centromeric to the DQA1 gene and was shown to be in tight linkage disequilibrium with HLA-DQ. Analysis of the linkage disequilibrium pattern revealed little additional diversity in DQ1-associated haplotypes. Almost all DQ1 subjects examined were DQCAR 103 or DQCAR 107 (13 and 15 CA repeats, respectively). In contrast, significant haplotypic diversity was observed for most DQ2-, DQ3-, and DQ4-associated haplotypes. These haplotypes often had longer allele sizes (DQCAR > 111, more than 17 CA repeats) and more DQCAR alleles per haplotype. These haplotypes also carried DQCAR alleles of different sizes, even though they bore the same DQA1 and DQB1 alleles, and sometimes the same DRB1 allele as well. These results indicate that DQCAR could be a useful marker to better define disease associations with HLA. Our results are also consistent with the hypothesis that CAR alleles with higher numbers of repeats have higher mutation rates and that recombination within the HLA-DR/DQ region is haplotype dependent.

HLA-A and -DRB4 genes in controlling the susceptibility to Hashimoto's thyroiditis

HLA-linked genetic factors involved in the pathogenesis of HT were studied in 71 patients with HT by serologic typing for HLA-A, -B, -C, -DR, and -DQ specificities and by DNA typing for HLA-DRB1, -DRB3, -DRB4, -DRB5, -DQA1, -DQB1, AND -DPB1 genes using the PCR-SSOP method. Typing results demonstrated significant positive associations of HT with HLA-A2 and -DRB4*0101 (DR53) (p < 0.01, RR = 2.03, EF = 0.61 and p < 0.0001, RR = 4.48, EF = 0.69, respectively). Although HLA-DR8, -DRB1*0403, -DQA*03, and -DQB1*0303 were statistically more prevalent in the patient group than in the controls, these associations were presumably due to the strong linkage disequilibria of these alleles with HLA-A2 or -DRB4*0101 in the Japanese population. Ninety-seven percent of the patients (69 out of 71) were positive for HLA-A2 or -DRB4*0101 compared to 79% in controls (RR = 8.7, p < 0.0005). The combination of HLA-A2 and -DRB4*0101 showed higher OR of risk for HT (OR = 12.8) than HLA-A2 (OR = 7.3) or DRB4*0101 (OR = 7.5) alone. These observations suggest that at least two loci, HLA-A and HLA-DRB4 together, may control the susceptibility to HT. On the other hand, the frequency of DQA1*0102 was significantly decreased in the patient group, suggesting that DQA1*0102 might confer resistance to HT.

[A case of chronic empyema due to tuberculosis with bronchopleural fistulae treated successfully by extraperiosteal air plombage thoracoplasty and omentoplasty]

A 63-year-old man, who had undergone induction of artificial pneumothorax at 20 years of age as a treatment for right tuberculosis, developed fever and cough. A chest X-ray film showed marked pleural effusion in the right chest. Examination of sputum and the pleural effusion revealed tubercle bacillus, and right tuberculous empyema was diagnosed. At surgery, the right thoracic cavity was occupied by empyema, and multiple bronchopleural fistulae were observed. Because of the presence of tubercle bacilli in the empyema cavity, extraperiosteal air plombage thoracoplasty was insufficient for control of the empyema. Therefore, omentoplasty was added. Two months after the operation, the patient was discharged in good condition. He has been doing well without any sign of recurrence of empyema for the last two years. Although extraperiosteal air plombage thoracoplasty is a considerably effective therapy for empyema, its curability rate is lower in cases like the present one in which bronchopleural fistulae and bacteria are present in empyema cavity, such as our case. We consider that our method, extrapriosteal air plombage thoracoplasty with omentoplasty, is a reliable one for control of empyema, in patient with high risk factors for recurrence, such as bronchopleural fistulae and bacteria in the cavity.

Pulmonary vasculitis with hypereosinophilia and episodic pulmonary hypertension: report of three siblings

Three siblings with eosinophilia who developed pulmonary hypertension are reported. They consisted of a 3 year old boy (case 1), a 9 year old boy (case 2) and a 13 year old girl (case 3), all of whom died within an 18 month period of severe episodic attacks of pulmonary hypertension and the resultant low cardiac output. Marked peripheral eosinophilia was found in cases 1 and 2, and mild eosinophilia in case 3. Open lung biopsy of case 1 revealed pulmonary arteritis with massive eosinophilic infiltration and intimal thickening of muscular arteries of 300-1500 microns in diameter. At autopsy, cases 2 and 3 showed almost similar findings, comprising widespread obliteration of the pulmonary arteries by concentric intimal thickening, medial hypertrophy and recanalized thrombi of arterioles. Rarely, there were foci of granulomas in the thickened intima surrounding birefringent foreign bodies. There were small areas of infarction in the lungs and heart due to arterial thrombi. Vascular lesions other than those in the lungs were mild and almost limited to the branches of the coronary arteries. Therefore, the present cases appear to be a single disease of pulmonary hypertension secondary to endothelial injury and the resultant intimal fibrosis probably evoked by toxic substances, although such agents were not confirmed.

Improvement of S-adenosylmethionine production by integration of the ethionine-resistance gene into chromosomes of the yeast Saccharomyces cerevisiae

An ethionine-resistance gene cloned from Saccharomyces cerevisiae DKD-5D-H was able to enhance S-adenosyl-L-methionine (AdoMet) accumulation when it was introduced into the yeast cells on multi-copy plasmid YEp13. In order to increase the AdoMet accumulation, the gene was integrated into the yeast chromosome by using a yeast transposon Ty element. When the YEp plasmid was used for the integration, the ethionine-resistance gene was efficiently inserted into the yeast chromosomes with a substantial increase in AdoMet productivity (about twofold) in comparison with that by the yeast cells carrying the gene on an extrachromosomal multi-copy plasmid.