Selenium, cadmium, zinc, copper, and iron concentrations in heart and aorta of patients exposed to environmental cadmium.
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Biomedical subjects
Publications and source records attributed to R Honda.
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The aim of this study was to identify the distribution of aquaporin-9 by immunohistochemistry in rat tissues using specific antipeptide antiserum which we recently produced. Anti-aquaporin-9 antibody was raised in New Zealand white rabbits immunized with a conjugate of synthetic aquaporin-9 peptide with bovine serum albumin. Immunohistochemical analysis was performed by avidin-biotin complex method. Aquaporin-immunoreactivity was visualized in the anterior pituitary, central nervous system, retina, thyroid gland, gastrointestinal tract, liver lung, pancreas and testis. When using antiserum preincubated with synthetic peptides or rat hypothalamus homogenate, which contains aquaporin-9 peptide, no significant stain of the hypothalamus was detected. These findings suggest that aquaporin-9 is widely distributed and that the method used is valuable in studying the distribution of aquaporin-9 in rats.
In this study, we compared the sensitivity and specificity of three immunofluorescence techniques used to detect circulating autoantibodies in dogs with pemphigus foliaceus (PF); living keratinocyte staining on a canine keratinocyte cell line, MCA-B1, indirect immunofluorescence (IIF) on canine lip and IIF on bovine esophagus. Sera from canine PF cases were positive in four out of 27 dogs (14.8%) using living keratinocyte staining on MCA-B1 cells method, and five (18.5%) and eight sera (29.6%) using IIF on canine lip and bovine esophagus methods, respectively. By contrast, none of the 31 sera from dogs with non-pemphigus dermatoses reacted with MCA-B1 cells, whereas two (6.5%) as well as five sera (16.1%) obtained from those dogs showed positive reactivity with IIF on canine lip and bovine esophagus, respectively. Our results suggest that, although it exhibits the least sensitivity, the positive reactivity obtained by living keratinocyte staining on MCA-B1 cells can support the diagnosis of canine PF.
A total of 1595 middle-aged healthy men consuming alcohol up to 120 ml per day and 538 without alcohol consumption were recruited from an occupational population, and their insulin resistance (IR) and beta-cell function (BC) were measured using the homeostasis model assessment (HOMA-IR and HOMA-BC), and the associations with alcohol consumption, blood pressure (BP), and serum gamma-glutamyltransferase (GGT) levels were analysed cross-sectionally. Both HOMA-IR and HOMA-BC were decreased with increasing alcohol consumption, but HOMA-BC corresponding to a level of HOMA-IR was 4-10 and 8-20% lower in drinkers consuming less than 60 ml of alcohol per day and those consuming more, respectively, than in nondrinkers, suggesting an altered fasting serum insulin-glucose relationship in alcohol consumers. Although BP was higher and HOMA-IR was lower in alcohol consumers than in nonconsumers, BP was higher at higher HOMA-IR irrespective of alcohol consumption. Elevations of serum GGT were positively associated with BP and HOMA-IR in both alcohol consumers and nonconsumers. Multiple regression analyses in the subjects showed that elevated serum GGT was an independent contributor to HOMA-IR elevations, and both serum GGT and HOMA-IR were significantly related to BP elevations after adjusting for alcohol consumption, age, body mass index, cigarette consumption, and physical activity at leisure. Although cross-sectional observations do not provide evidence of causal association, the results suggest that elevated serum GGT in alcohol consumers relates to elevations of IR and that the elevated insulin resistance relates, at least partly, to BP elevations in alcohol consumers.
AIMS: Since 1979 the diseased kidneys of 96 patients on replacement therapy with chronic renal failure due to chronic glomerulonephritis have been followed to investigate the development of acquired cysts and tumors. This is a report of the 20-year follow-up. MATERIALS AND METHODS: Ninety-six patients were followed using periodic CT scan and were divided into hemodialysis, renal transplantation, bilateral nephrectomy and deceased groups during the follow-up. In the hemodialysis group, 36 patients (19 males, 17 females) were followed for 20 years. RESULTS: Kidney volumes which were 57.8 (1.51) (geometric mean (geometric SD)) ml at start of the follow-up had become 185.3 (2.03) ml 20 years later in males, and in females, 57.3 (1.64) ml had become 99.7 (2.36) ml. The increased rate was 3.2 (2.06) fold in males and 1.7 (2.57) fold in females. This enlargement of the kidneys was due to acquired cysts. Kidney volumes at the 20-year follow-up had increased more significantly than those at the 15-year follow-up in males; however, kidney volumes at the 20-year follow-up had not changed in females, if compared with data at the 15-year follow-up. Kidney volumes in males at 20-year follow-up were significantly larger than those in females (p = 0.0232). Males with more than 3.2-fold in kidney volume increase at the 20-year follow-up were under the age of 40 at entry into this study (p = 0.0055), although the correlation between the degree of kidney volume increase and age was not significant (p = 0.0910). Kidney volumes in the transplantation group remained small. There was no new renal cell carcinoma development after 15-year follow-up except for the local recurrence of a previous operated case. Although 7 of 44 patients died during the past 20 years due to malignancy, no patient died of renal cell carcinoma because of early detection and treatment. One patient died of retroperitoneal bleeding, which is a complication of acquired renal cystic disease. CONCLUSION: Male preponderance of acquired cysts was maintained at the 20-year follow-up. There was a tendency for the rate of increase in acquired renal cystic disease to be larger in young males. No one died of renal cell carcinoma, although the incidence of renal cell carcinoma was high.
Orientals have unique genetic polymorphisms in ethanol metabolizing enzymes, such as alcohol dehydrogenase-2 (ADH2), aldehyde dehydrogenase-2 (ALDH2) and cytochrome P450-2E1 (CYP2E1). Of the three studies conducted to clarify the influence of ALDH2 genotypes on sensitivity to the pressor effects of alcohol in Japanese, only one was suggested, though indirectly, higher sensitivity in drinkers having the genotype of inactive ALDH2. This discrepancy prompted us to determine ADH2, ALDH2 and CYP2E1 genotypes in the genomic DNA extracted from white blood cells of 855 healthy middle-aged Japanese men, and to analyse the associations with the alcohol-blood pressure (BP) relationship. No marked differences were found in the relationship among the genotypes of ALDH2, although the subjects with intact ALDH2 showed a slightly higher BP than those with inactive ALDH2 probably due to under-reporting of alcohol consumption in those with intact ALDH2 who could thus drink more. No significant influence of ADH2 genotypes was observed. A higher BP was noted in large volume alcohol consumers having c2/c2 genotype of CYP2E1. Multivariate regression analysis adjusting for the effects of age, body mass index and the volume of alcohol consumed, all of which are strong determinants of BP levels, showed only a marginal effect of c2 allele of CYP2E1 on diastolic BP elevations with increases in alcohol consumption. Thus it is concluded that the genetic polymorphisms in ethanol-metabolizing enzymes do not greatly influence the alcohol-BP relationship in Japanese men.
OBJECTIVE: The effects of cadmium (Cd) on birth weight have been discussed in the scientific literature. However, investigations on the effects of maternal body burden of Cd on the next generation during pregnancy and lactation have been limited. The relation between maternal exposure to Cd and pregnancy outcome or Cd in breast milk in Japanese mothers was investigated. METHODS: Cd concentrations in urine and colostrum milk samples of 57 mothers were measured by atomic absorption spectrophotometery. The relations between maternal urinary Cd and infant growth, gestational age at birth, and Cd in breast milk were investigated. RESULTS: The rate of perterm deliveries of mothers with higher urinary Cd (> or =2 nmol/mmol creatinine (Cr)) was higher than that of mothers with lower urinary Cd (<2 nmol/mmol Cr). The gestational age was significantly correlated with urinary Cd even after adjustment for maternal age. The height and weight of newborn infants of mothers with higher urinary Cd were significantly lower than those of the newborn infants of mothers with lower urinary Cd, but these decreases were ascribed to early delivery induced by Cd. The Cd in breast milk of mothers with higher urinary Cd was significantly higher than that of mothers with lower urinary Cd. A significant positive correlation was found between maternal urinary Cd and Cd in breast milk. CONCLUSION: Maternal exposure to Cd seems to increase early delivery, which leads to a lower birth weight. Also, the Cd is transferred in part to the next generation through breast milk after birth.
The mechanism of myocardial stunning has been studied extensively in rodents and is thought to involve a decrease in Ca(2+) responsiveness of the myofilaments, degradation of Troponin I (TnI), and no change in Ca(2+) handling. We studied the mechanism of stunning in isolated myocytes from chronically instrumented pigs. Myocytes were isolated from the ischemic (stunned) and nonischemic (normal) regions after 90-minute coronary stenosis followed by 60-minute reperfusion. Baseline myocyte contraction was reduced, P<0.01, in stunned myocytes (6.3+/-0.4%) compared with normal myocytes (8.8+/-0.4%). The time for 70% relaxation was prolonged, P<0.01, in stunned myocytes (131+/-8 ms) compared with normal myocytes (105+/-5 ms). The impaired contractile function was associated with decreased Ca(2+) transients (stunned, 0.33+/-0.04 versus normal, 0.49+/-0.05, P<0.01). Action potential measurements in stunned myocytes demonstrated a decrease in plateau potential without a change in resting membrane potential. These changes were associated with decreased L-type Ca(2+)-current density (stunned, -4.8+/-0.4 versus normal, -6.6+/-0.4 pA/pF, P<0.01). There were no differences in TnI, sarcoplasmic reticulum Ca(2+) ATPase (SERCA2a), and phospholamban protein quantities. However, the fraction of phosphorylated phospholamban monomer was reduced in stunned myocardium. In rats, stunned myocytes demonstrated reduced systolic contraction but actually accelerated relaxation and no change in Ca(2+) transients. Thus, mechanisms of stunning in the pig are radically different from the widely held concepts derived from studies in rodents and involve impaired Ca(2+) handling and dephosphorylation of phospholamban, but not TnI degradation.
Cardiac-specific expression of an activated calcineurin protein in the hearts of transgenic (CLN) mice produces a profound hypertrophy that rapidly progresses to heart failure. While calcineurin is regulated by Ca2+, the potential effects of calcineurin on cardiac myocyte Ca2+ handling has not been evaluated. To this end, we examined L-type Ca2+ currents (I(Ca)) in left ventricular myocytes. CLN myocytes had larger (approximately 80%) cell capacitance and enhanced I(Ca) density (approximately 20%) compared with non-transgenic (NTG) littermates, but no change in the current-voltage relationship, single-channel conductance or protein levels of alpha 1 or beta 2 subunit of L-type Ca2+ channels. Interestingly, the kinetics of I(Ca) inactivation was faster (approximately two-fold) in CLN myocytes compared with NTG myocytes. Ryanodine application slowed the rate of I(Ca) inactivation in both groups and abolished the kinetic difference, suggesting that Ca2+ dependent inactivation is increased in CLN myocytes due to altered SR Ca2+ release. Treatment of CLN mice with Cyclosporine A (CsA), a calcineurin inhibitor, prevented myocyte hypertrophy and changes in I(Ca) activity and inactivation kinetics. However, there was no direct effect of CsA on I(Ca) in either NTG or CLN myocytes, suggesting that endogenous calcineurin activity does not directly regulate Ca2+ channel activity. This interpretation is consistent with the observation that I(Ca) density, inactivation kinetics and regulation by isoproterenol were normal in cardiac-specific transgenic mice expressing calcineurin inhibitory protein domains from either Cain or AKAP79. Taken together these data suggest that chronic activation of calcineurin is associated with myocyte hypertrophy and a secondary enhancement of intracellular Ca2+ handling that is tied to the hypertrophy response itself.
OBJECTIVE: The purpose of this study was to assess the accuracy, informative rate, detection rate, and clinical utility of prenatal interphase fluorescence in situ hybridization (FISH) analysis of amniotic fluid samples from Japanese women. METHODS: Amniotic fluid specimens from 2,639 Japanese women were received for prenatal interphase FISH and chromosome analysis. A questionnaire was designed to evaluate FISH clinical utility by collaboration sites. RESULTS: Based on 2,319 tested samples, the accuracy (100%), informative (94%), and detection (87.6%) rates were all high. The accuracy (100%), informative (90.2%), and detection (90.0%) rates were also remarkable in third-trimester pregnancies. We perceive significant advantages from this test regarding medical management and patient satisfaction. CONCLUSIONS: This novel report shows that in Japan prenatal interphase FISH testing is highly informative and accurate, not only in second-trimester pregnancies but also in third-trimester pregnancies. This test provides advantages to both physicians and patients, provided that its capabilities and limitations are understood.
Diels-Alder (DA) reactions of 3- or 5-nitro-2(1H)-pyridones and nitro-2(1H)-pyridones containing a methoxycarbonyl group with 2,3-dimethyl-1,3-butadiene were examined. The DA reactions of 3-nitro-2(1H)-pyridones in this paper represent, to the best of our knowledge, the first report of DA reactions of 3-substituted 2(1H)-pyridones and consequent production of isoquinolones. Performing the same reactions with 5-nitro-2(1H)-pyridones yielded quinolones. DA reactions of 2(1H)-pyridones with nitro and methoxycarbonyl groups produced isoquinolones, quinolones and phenanthridones (the double DA adducts), aromatized or hydrogenated. The substituent effect was evaluated by calculating the activation energy, using the ab initio MO method.
Cardiac-specific overexpression of murine cardiac calsequestrin results in depressed cardiac contractile parameters, low Ca(2+)-induced Ca(2+) release from sarcoplasmic reticulum (SR) and cardiac hypertrophy in transgenic mice. To test the hypothesis that inhibition of phospholamban activity may rescue some of these phenotypic alterations, the calsequestrin overexpressing mice were cross-bred with phospholamban-knockout mice. Phospholamban ablation in calsequestrin overexpressing mice led to reversal of the depressed cardiac contractile parameters in Langendorff-perfused hearts or in vivo. This was associated with increases of SR Ca(2+) storage, assessed by caffeine-induced Na(+)-Ca(2+) exchanger currents. The inactivation time of the L-type Ca(2+) current (I(Ca)), which has an inverse correlation with Ca(2+)-induced SR Ca(2+) release, and the relation between the peak current density and half-inactivation time were also normalized, indicating a restoration in the ability of I(Ca) to trigger SR Ca(2+) release. The prolonged action potentials in calsequestrin overexpressing cardiomyocytes also reversed to normal upon phospholamban ablation. Furthermore, ablation of phospholamban restored the expression levels of atrial natriuretic factor and alpha-skeletal actin mRNA as well as ventricular myocyte size. These results indicate that attenuation of phospholamban function may prevent or overcome functional and remodeling defects in hypertrophied hearts.
A novel controlled release system, the PVA swelling controlled release system, was evaluated in vitro and in vivo using emedastine difumarate as a model drug. In the in vitro drug release study, the release profile of this system had almost zero-order kinetics. The effect of dissolution test conditions, which were paddle rotation speed, mechanical stress, and pH of the dissolution medium, on the release rate was very small. In an in vivo human bioavailability study of two formulations with a different release rate, the absorption rate was dependent on the release rate, and both formulations showed constant plasma levels of the drug for long periods. The variations of plasma concentration on the simulation of repetitive administration of the formulations at 24-h intervals were almost equal to the experimental value for the twice daily controlled release capsule currently on the market. It is concluded that the PVA swelling controlled release system is feasible for a long-acting preparation as a once-daily treatment.
The periodic expression of cell cycle proteins is important for the regulation of cell cycle progression. The amount of CDK inhibitor, p27(kip1), one such protein, seems to be regulated by the ubiquitin-proteasome system. The ubiquitin ligase (E3) toward p27(kip1) is thought to be SCF(skp2). The activity of SCF(skp2) was increased by the addition of Roc1 protein to the complex. Furthermore, the ubiquitination of p27(kip1) seemed to be dependent on the phosphorylation of T187 of p27(kip1) because the mutant T187A was not ubiquitinated at all in an in vitro ubiquitination system. Cullin-1, a component of SCF, is modified by ubiquitin-like protein Nedd8. The modification site of cullin-1 was shown to be K696 because the K696R mutant was not modified. When the effect of the Nedd8 modification on the SCF(skp2) activity toward p27(kip1) was investigated, the activity was markedly decreased by using the Nedd8-unmodified mutant cullin-1 (K696R), indicating that the modification may play an important role on the SCF(skp2) activity toward p27(kip1).
We previously showed that oncoprotein MDM2 has ubiquitin ligase activity toward tumor suppressor p53. In that paper, we showed very weak homology in the carboxyl terminal portion between MDM2 and E6AP (HECT domain). We mutated the cysteine residue (C464) corresponding to the residue essential for the ubiquitin ligase activity of E6AP and this mutation diminished the ligase activity of MDM2. The cysteine residue described above is also one of the cysteine residues that form the RING finger domain of MDM2. We tried to find out whether the diminishing of the activity by the mutation is attributable to the disruption of the RING finger domain or not. When the ring finger domain of MDM2 was deleted, the truncation mutant did not have the ubiquitin ligase activity. When we mutated the seven cysteine residues of RING finger domain of MDM2 in the carboxyl terminus, the disruption of each residue in the RING finger completely diminished the ubiquitin ligase activity of MDM2 toward MDM2 itself and toward tumor suppressor p53. These data indicate that the RING finger domain in MDM2 is essential for its ubiquitin ligase activity toward p53 and itself.
Polyvinyl alcohol (PVA) is hydrophilic and swells easily by absorbing water. Some grades of PVA, whose degree of hydrolysis is 96.0 and 97.5 mol%, showed volume expansion of 500% by swelling at 37 degrees C. This expansion was inhibited by swelling controlling agents, namely salts. Based on this unique property of PVA, a new type of controlled release system was developed. The release rate was controlled by the content of PVA and a swelling controlling agent in the core tablet, and the composition and coating level of the film. Emedastine difumarate was incorporated into the system. At the initial stage of drug release, the rate of release was determined by the permeation through the membrane - a mixture of ethylcellulose and hydroxypropyl methylcellulose. After the membrane burst by the swelling of PVA, the release rate was controlled by the PVA matrix. Release patterns of zero-order, two phase zero-order, and rapid release after lag-time were obtained with this system.
Germidine and germerine, the Veratrum alkaloids lowered blood pressure accompanied with positive chronotropy and inotropy in mice. Germerine was more potent than germidine in both blood-pressure lowering and positive inotropy, whereas veratridine produced negative chronotropy and positive inotropy. An acyl group (an acetyl or a 2-methylbutyroyl group) at 3-O-R1 position and a 2-methylbutyroyl group at 15-O-R2 position in germine were important to produce the positive inotropy and chronotropy. The presence of a veratroyl group at 3-O-R1 position and a free hydroxyl group at 15-O-R2 position may be essential to produce the negative chronotropy by veratridine. The positive inotropy by germidine and veratridine may be due to TTX-resistant Na+ channel activation.
The assembly of the lipid-linked oligosaccharide, Glc(3)Man(9)GlcNAc(2)-P-P-Dol, occurs on the rough ER membrane in an ordered stepwise manner. The process is highly conserved among eukaryotes. In order to isolate the human mannosyltransferase I (MT-I) gene involved in the process, we used the Saccharomyces cerevisiae MT-I gene ( ALG1 ), which has already been cloned. On searching the EST database with the amino acid sequence of the ALG1 gene product, we detected seven related human EST clones. A human fetal brain cDNA library was screened by PCR using gene-specific primers based on the EST nucleotide sequences and a 430 bp cDNA fragment was amplified. The cDNA library was rescreened with this 430 bp cDNA, and two cDNA clones (HR1-3 and HR1-4) were isolated and sequenced. On a homology search of the EST database with the nucleotide sequence of HR1-3, we detected a novel human EST clone, AA675921 (GenBank accession number). Based on the nucleotide sequences of AA675921 and HR1-4, we designed gene-specific PCR primers, which allowed to amplify a 1.8 kb cDNA from human fetal brain cDNA. This cDNA was cloned and shown to contain an ORF encoding a protein of 464 amino acids. We designated this ORF as Hmat-1. The amino acid sequence deduced from the Hmat-1 gene showed several highly conserved regions shared with the yeast and nematode MT-I sequences. Furthermore, this 1.8 kb cDNA successfully complemented the S. cerevisiae alg1-1 mutation, indicating that the Hmat-1 gene encodes the human MT-I and that the function of this enzyme was conserved between yeast and human.