[Comparison of matrix modifiers for simple determination of cadmium in blood and urine by graphite furnace atomic absorption spectrophotometry].
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Cadmium↗
Biomedical subjects
K Hosoda
Publications and source records attributed to K Hosoda.
[Histological assessment of the liver long after interferon treatment in patients with chronic type C hepatitis].
The effects of interferon on chronic hepatitis C long after the treatments were assessed biochemically, virologically and histologically. Among the 12 cases who showed normal alanine aminotransferase (ALT) levels and seroconversion of HCV RNA after treatment, histological improvements were observed in 8. In contrast, among the 11 cases who showed abnormal ALT levels and HCV viremia after treatment, histological improvements were observed in only 1. Histological improvement of the liver was thus, well correlated with normalization of ALT levels and seroconversion of HCV RNA. These data indicate that complete histological resolution of chronic hepatitis C is obtainable by elimination of the virus by interferon treatment.
Biomarkers↗
[Basic aspects of bone metabolic markers].
Bone formation and bone resorption are altered in most metabolic bone diseases. Recent advances in measurement of bone metabolic markers arrows as the non-invasive investigation of bone metabolic balance. The rate of formation or degradation of the bone matrix can be assessed by the measurement of bone specific proteins and it's degradative products. Among the posturated products, osteocalcin, carboxy-terminal propeptide of type I collagen (PICP) are considered to be more specific indices to know the osteoplastic function. On the other hand, pyridinoline or deoxypyridinoline in urine strongly reflects bone resorption rate. However some criticisms still exist in the evaluation of serum or urinary levels of bone metabolic markers, especially in formation markers. In adults, bone formation marker such as osteocalcin negatively correlated with their bone mineral density. On the other hand, in children, osteocalcin positively correlated with height velocity. Therefore we have to pay special attention to dysfunction of osteoblast, such as retarded calcification in evaluation of serum level of bone formation markers.
Biomarkers↗
[Bone metabolic markers in osteoporosis].
Since osteoporosis has been defined as "state of low bone mass", the bone mineral measurement has been utilized as a golden standard. However some limitations in bone mineral measurement such as expensive machine, very small extent in bone mineral change and/or required long term observation to detect significant change in bone mass, are prohibited extensive use. On the other hand, recent advances in the measurement of bone metabolic markers arrows us to utilize in the diagnosis of osteoporosis as well as in the monitoring of drug efficacy for osteoporosis. Especially in the monitoring of osteoporosis under some treatment, the magnitude of the change in bone metabolic markers are about 10 times higher than that in bone mineral density. Therefore, the measurement of bone metabolic markers may be utilized more widely in the clinical field of not only osteoporosis but also the other metabolic bone diseases in near future.
Amino Acids↗
[Dawn hypertension in pre-Cushing's syndrome: report of two cases].
Two adrenal tumors were incidentally discovered in the patients with dawn hypertension. They had no clinical features of Cushing's syndrome. These cases were regarded as pre-Cushing's syndrome by endocrinological evaluation. After adrenalectomy, the adrenal hormone regulation was normalized and dawn hypertension disappeared. Our findings suggest that dawn hypertension is a typical clinical sign of pre-Cushing's syndrome and this syndrome may represent a premature status of Cushing's syndrome.
Adrenalectomy↗
Detection of hepatitis C virus RNA in acute non-A, non-B hepatitis as an early diagnostic tool.
The presence of hepatitis C virus RNA was examined in the sera of 32 patients with acute non-A, non-B hepatitis. Hepatitis C virus RNA was extracted from serum, reverse transcribed to cDNA and amplified by two rounds of polymerase chain reaction. Hepatitis C virus RNA was detected in all patients who developed anti-C100-3 as well as 79% who did not. These data suggest that hepatitis C virus accounts for most cases of acute non-A, non-B hepatitis whether anti-C100-3-positive or not. In addition, hepatitis C virus RNA was detected in the earliest serum samples, 9 +/- 11 weeks before anti-C100-3, and thus may be valuable as a diagnostic marker for acute hepatitis C.
Base Sequence↗
A microneutralization enzyme immunoassay for antibody to human cytomegalovirus.
We have developed a relatively rapid, sensitive and quantitative microneutralization assay for antibody to human cytomegalovirus (HCMV). Cell monolayers in 96-well microtiter plates inoculated with pre-incubated virus-antibody mixtures were fixed after 3 days. Infectious foci were stained with peroxidase-labeled human monoclonal antibody to a 64 kDa immediate early antigen of HCMV, and the plates were read at OD450. The 50% neutralization titer of the antibody was calculated. A study with 20 human sera and a human monoclonal antibody which neutralizes virus showed that this microneutralization enzyme immunoassay is more sensitive than, and as quantitative as, the conventional plaque reduction assay for antibody to HCMV. The neutralizing antibody titers of each sample measured by these two methods showed good correlation (n = 19, r = 0.884). Thus, this new assay is a useful and valid alternative to the conventional method for mass screening of sera and hybridoma fluids, and considerably more rapid.
Antibodies, Monoclonal↗
The human endothelin-B receptor gene. Structural organization and chromosomal assignment.
The gene encoding the human endothelin-B receptor (hET-BR) has been isolated, and its structural organization and chromosomal assignment have been determined. Southern blot analysis demonstrated a single copy of the hET-BR gene in the human genome. The hET-BR gene spans 24 kilobases and consists of seven exons and six introns. The size range for exons is 109-2855 base pairs, although that for introns is 0.2-14.5 kilobases. Every intron occurs near the border of the putative transmembrane domain in the coding region. The major transcription initiation sites were mapped to the positions 258 and 229 base pairs upstream of the ATG initiation codon by primer extension and nuclease S1 protection experiments. The 5'-flanking region of the hET-BR gene lacks conventional TATA and CCAAT boxes but contains a sequence of potential Sp1 binding sites upstream of the transcription initiation sites. There are some canonical consensus sequences of cis-elements including GATA motif, acute phase reactant regulatory element, and E box. Using human-rodent somatic hybrid cell lines, the hET-BR gene was assigned to human chromosome 13. The present study will lead to a better understanding of the mechanism for the transcriptional regulation of the hET-BR gene and will give a clue as to how to search for possible genetic disorders of hET-BR.
Amino Acid Sequence↗
Secretion of osteocalcin and its propeptide from human osteoblastic cells: dissociation of the secretory patterns of osteocalcin and its propeptide.
Specific immunoassay systems for intact human osteocalcin (I-OC) and its 26-residue propeptide have been newly developed to assess their usefulness as biochemical markers of bone metabolism. Using human cultured osteoblastic periosteal cells, we monitored 24 h secretion of these molecules from the osteoblastic cells and also examined the deposition of Ca, P, and I-OC on the extracellular matrix. At day 5, both I-OC and its propeptide were secreted by osteoblastic cells in a concentration-dependent manner by treatment with 1,25-(OH)2D3. This propeptide was not detected in the serum of adult subjects but was detected in the serum of normal children, which confirmed this in vitro result of propeptide secretion. The secretion of I-OC into medium transiently decreased at day 11, when the rapid accumulation of I-OC, Ca, and P, namely mineralization, was observed on the extracellular matrix of osteoblastic cells, although secretion of the propeptide constantly increased throughout the culture period. Therefore, the ratio of the amount of propeptide to I-OC in the supernatant markedly increased when mineralization started. These data demonstrate the superior specificity of propeptide as a marker of osteoblastic function in vitro compared with I-OC and that monitoring the changes in propeptide to I-OC ratios in the culture supernatant may be useful for predicting the timing of mineralization on the extracellular matrix of osteoblastic cells.
Adolescent↗
Long-term effects of alpha-interferon for treatment of chronic hepatitis C in terms of histological changes with aminotransferase normalization and hepatitis C virus RNA seroconversion.
To assess the effects of interferon treatment on chronic hepatitis C, histological changes long after treatment were compared with normalization of aminotransferases and seroconversion of hepatitis C virus RNA. Twenty one histologically proven chronic hepatitis C patients received alpha-interferon, 3 million units 3 times weekly for 12 months. Hepatitis C virus RNA was detected by reverse transcription/polymerase chain reaction method. Follow-up liver biopsies were performed 3 to 5 years after treatment. Fourteen of 21 (67%) patients showed normal aminotransferases for 3 to 5 years after treatment. HCV RNA seroconversion was observed in 12 of these patients. These responders showed improvement in histological activity indices and in histological findings. Two patients improved from chronic active hepatitis 2a to nonspecific changes, 1 from chronic active hepatitis 2a to portal fibrosis, 1 from chronic active hepatitis 2a to chronic persistent hepatitis and 1 from chronic active hepatitis 2b to chronic persistent hepatitis. Histological improvement of the liver correlated well with normalization of aminotransferases and seroconversion of hepatitis C virus RNA. These data indicate that complete histological resolution of chronic hepatitis C can be achieved by elimination of the virus with interferon treatment.
Alanine Transaminase↗
Surfactant apoprotein A secretion by human tracheobronchial epithelial cells.
To determine whether surfactant apoproteins are produced locally by the airway walls, we used a two-site simultaneous immunoassay with monoclonal antibodies and measured the surfactant apoprotein-A (SP-A) content in media cultured with human airway explants or cultured epithelial cells. Tracheobronchial explants were cultured for 2 successive periods (periods I and II). Significant SP-A concentrations were detected in both periods. Methacholine (MCh) or isoproterenol (ISP), added to the medium at the beginning of period II, reduced the ratio of SP-A concentration in period II to that in period I, compared to samples without treatment. The SP-A concentration in the medium at the confluent period of cultured epithelial cells was significantly higher than at the mid-period, indicating that SP-A secretion is dependent on the cell number. The supernatant from explants stimulated by MCh was capable of reducing SP-A secretion from cultured epithelial cells. Immunohistochemical study of SP-A using monoclonal antibody demonstrated positive immunoperoxidase staining in the cytoplasm of epithelial cells. Further, Western blots of electrophoresed proteins from epithelial cells showed the characteristic properties of SP-A. These findings indicate that tracheobronchial epithelium can secrete SP-A.
Apolipoproteins A↗
Regulation of beta 1-adrenergic receptor mRNA and ligand binding by antidepressant treatments and norepinephrine depletion in rat frontal cortex.
The number of beta 1-adrenergic receptor (beta 1AR) binding sites is decreased by chronic antidepressant treatments, including electroconvulsive seizure (ECS) and imipramine, whereas administration of agents that deplete norepinephrine (NE) increases the number of beta 1AR binding sites in cerebral cortex. The present study was carried out to examine the influence of these treatments on levels of beta 1AR mRNA in frontal cortex to study the molecular mechanisms that underlie the regulation of beta 1ARs in brain. Levels of beta 1AR mRNA were measured by RNase protection analysis using a riboprobe derived from rat beta 1AR cDNA, and the levels of beta AR binding were measured using the nonselective ligand [3H]CGP-12177. Studies to verify the specificity of the RNase protection assay revealed that the distribution of beta 1AR mRNA was in agreement with the reported distribution of beta 1AR ligand binding: Levels of beta 1AR mRNA were highest in cerebral cortex or frontal cortex, intermediate in neostriatum, hippocampus, lung, and heart, and lowest in cerebellum, kidney, and liver. Chronic ECS treatment (once daily for 10 days) significantly decreased levels of beta AR ligand binding and resulted in a corresponding, time-dependent down-regulation of beta 1AR mRNA levels in frontal cortex. However, imipramine administration regulated levels of beta 1AR mRNA in a biphasic manner, with treatments for 7-14 days increasing and treatments for 18-21 days decreasing levels of beta 1AR mRNA in frontal cortex. In contrast, levels of [3H]CGP-12177 ligand binding were decreased at all time points examined (3-21 days).(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Evaluation of delta-aminolaevulinic acid in blood of workers exposed to lead.
Exposure-effect and exposure-response relation between exposure to lead and delta-aminolaevulinic acid concentration in blood (ALA-B) were examined in 238 male workers exposed to lead. Concentrations of ALA-B ranged from 26 to 352 micrograms/l and lead concentrations in blood (Pb-B) from 7.1 to 86.0 micrograms/dl. Concentrations of ALA-B correlated closely with concentrations of Pb-B (r = 0.74), and increased ALA-B concentration occurred at Pb-B concentrations of around 30 micrograms/dl. Exposure-response curves indicated that the 50 percentile response doses were roughly 30, 40, and 50 micrograms/dl Pb-B when cut off points of ALA-B were set at 50, 60, and 70 micrograms/l respectively. The sensitivity and specificity of measurements of ALA-B concentrations for health screening were sufficiently high when the health based exposure limits of lead were set at 30-50 micrograms/dl. Moreover, a pronounced increase in ALA-B concentrations occurred when the inhibition rate of erythrocyte ALA dehydratase exceeded 85%. These findings suggest that ALA-B is a useful indicator for assessing the early effects of exposure to lead on haem biosynthesis.
Adult↗
Downregulation of C-receptor by natriuretic peptides via ANP-B receptor in vascular smooth muscle cells.
The natriuretic peptide system comprises at least three ligands, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) and three receptors, the ANP-A receptor, the ANP-B receptor, and the clearance (C) receptor. In the present study, the regulation of natriuretic peptide receptors by their ligands was investigated in cultured rat vascular smooth muscle cells (SMC). The treatment of vascular SMC with ANP, BNP, or CNP decreased the C-receptor density significantly, and the rank order of potency for this downregulation was CNP > ANP > BNP. This rank order was the same as that for guanosine 3',5'-cyclic monophosphate (cGMP) production by ANP, BNP, or CNP in vascular SMC and also the same as that for the ligand selectivity of the ANP-B receptor rather than the C-receptor. The incubation of vascular SMC with 8-bromoguanosine 3',5'-cyclic monophosphate significantly decreased the C-receptor density and its mRNA expression. These results suggest that the down-regulation of the C-receptor by natriuretic peptides is induced not by the binding of natriuretic peptides to the C-receptor but by the activation of the ANP-B receptor-cGMP pathway.
Animals↗
Mutations in core nucleotide sequence of hepatitis B virus correlate with fulminant and severe hepatitis.
Infection with hepatitis B virus leads to a wide spectrum of liver injury, including self-limited acute hepatitis, fulminant hepatitis, and chronic hepatitis with progression to cirrhosis or acute exacerbation to liver failure, as well as an asymptomatic chronic carrier state. Several studies have suggested that the hepatitis B core antigen could be an immunological target of cytotoxic T lymphocytes. To investigate the reason why the extreme immunological attack occurred in fulminant hepatitis and severe exacerbation patients, the entire precore and core region of hepatitis B virus DNA was sequenced in 24 subjects (5 fulminant, 10 severe fatal exacerbation, and 9 self-limited acute hepatitis patients). No significant change in the nucleotide sequence and deduced amino acid residue was noted in the nine self-limited acute hepatitis patients. In contrast, clustering changes in a small segment of 16 amino acids (codon 84-99 from the start of the core gene) in all seven adr subtype infected fulminant and severe exacerbation patients was found. A different segment with clustering substitutions (codon 48-60) was also found in seven of eight adw subtype infected fulminant and severe exacerbation patients. Of the 15 patients, 2 lacked precore stop mutation which was previously reported to be associated with fulminant hepatitis. These data suggest that these core regions with mutations may play an important role in the pathogenesis of hepatitis B viral disease, and such mutations are related to severe liver damage.
Adult↗
Low doses of endothelin-1 inhibit atrial natriuretic peptide secretion.
To clarify the interaction between endothelin-1 (ET-1) and atrial natriuretic peptide (ANP), the effects of ET-1 on ANP secretion were investigated in isolated perfused rat hearts and in conscious unrestrained rats. Perfusion with 10(-9) M ET-1 stimulated ANP secretion from the isolated perfused rat heart. However, 10(-10) M ET-1 significantly decreased ANP secretion for the initial 15 min of the perfusion period. The perfusion with 10(-11) M ET-1, which is near the plasma level of ET-1 (2 x 10(-12) M), inhibited ANP secretion throughout the perfusion period. The perfusion of 10(-12) M ET-1 slightly decreased ANP secretion. After the ET-1 perfusion period, ANP secretion increased in proportion to ET-1 dose. The inhibitory action of ET-1 on ANP secretion was almost abolished by simultaneous perfusion of indomethacin, a cyclooxygenase inhibitor, but not by methylene blue, an inhibitor of soluble guanylate cyclase. In conscious unrestrained rats the iv infusion of 1 pmol/kg.min ET-1, which doubled the plasma ET-1 level, slightly but significantly decreased the plasma ANP level 5 and 10 min after the initiation of the infusion. The infusion of 10 and 30 pmol/kg.min ET-1 increased the plasma ANP level. These results demonstrate that low doses of ET-1 exert an inhibitory and short-acting action on ANP secretion from the heart, although high doses of ET-1 exert stimulating and long-lasting action, and suggest that prostanoids are involved in this inhibitory action.
Animals↗
A cross-sectional study on osteocalcin levels in gingival crevicular fluid from periodontal patients.
The purpose of the present study was to determine the levels of osteocalcin, a bone specific matrix protein, in gingival crevicular fluid (GCF) from periodontal disease patients and to investigate the relationship between GCF osteocalcin levels and clinical parameters. Nineteen initial visit patients, 5 patients with gingivitis and 14 patients with adult periodontitis, participated in this study. The clinical parameters including probing depth, attachment level, gingival index, and tooth mobility were recorded following careful sampling of GCF with a filter paper strip harvested for 3 minutes. Osteocalcin adsorbed on a strip was extracted in a plastic tube containing 150 microliters of 10 mM sodium phosphate buffer (pH 6.5). GCF osteocalcin was determined by a newly-developed, high sensitive enzyme immunoassay which could recognize the N-terminal 20 residue peptide. In gingivitis patients, no significant amounts of osteocalcin were detected. In periodontitis patients, on the other hand, osteocalcin levels were detected, ranging between 0 and 540 pg/tube and positively correlated with these clinical parameters (P < 0.01). Moreover, in several sites in GI = 3 group, extremely higher levels of GCF osteocalcin were detected. These results strongly suggest that in addition to the presence of GCF osteocalcin the levels of osteocalcin may reflect the degree of the periodontal inflammation at the sampled sites.
Adolescent↗
[Molecular biology of endothelins and endothelin receptors].
Endothelin (ET) was initially identified as a potent vasoconstrictor peptide with 21 amino-acid residues, produced by cultured porcine aortic endothelial cells. Cloning of the ET genes revealed the existence of three isopeptides, ET-1, ET-2 and ET-3, which are widely distributed in a variety of tissues and possess wide variety of pharmacological functions. Recently, two subtypes of ET receptor have been isolated by the expression cloning technique and the molecular characteristics of the receptors were elucidated. Subsequently, the structural organizations of the ET receptor genes have been investigated. This article discusses the structure, function and expression of ET ligands and receptors from the molecular biological aspect.
Amino Acid Sequence↗