Associations between the levels of sclerostin, phosphate, and fibroblast growth factor-23 and treatment with vitamin D in hemodialysis patients with low intact PTH level

Serum sclerostin levels could be closely associated with serum phosphate and fibroblast growth factor-23 levels in hemodialysis patients with low intact parathyroid hormone (PTH) levels. Further study is required to indicate whether these close associations are present in patients with spontaneously low PTH levels without any vitamin D treatment.

INTRODUCTION

Intact parathyroid hormone (iPTH) is involved in the interaction between sclerostin and phosphate/fibroblast growth factor-23 (FGF23) in animal models. However, their relationship in patients on hemodialysis (HD) is unclear.

METHODS

Data of 102 HD patients were collected regarding clinical and laboratory parameters and mineral bone disorder medications. The patients were divided into subgroups according to the iPTH level (A, <70 pg/mL; B, 70-150 pg/mL; C, 150-300 pg/mL; and D, ≥ 300 pg/mL).

RESULTS

The sclerostin level was significantly and positively correlated with phosphate and log of FGF23 levels in subgroups A, B, and combined A and B. Multiple linear regression analysis in the combined A and B subgroup revealed that male sex (t = 3.24, P = 0.01; 95% confidence interval [CI] 11.78 to 50.43) and phosphate level (t = 2.13, P = 0.04; 95% CI, 1.08 to 36.91) were independent factors for serum sclerostin level. The log of serum FGF23 level (t = 1.90, P = 0.06, 95% CI -1.85 to 63.50) appeared to be an important factor for serum sclerostin level. The frequency of patients using vitamin D treatment was not significantly different among subgroups A (93.1%), B (88.0%), C (85.2%), and D (90.5%).

CONCLUSION

Serum sclerostin levels were associated with serum phosphate and FGF23 levels in patients with low iPTH levels. Further study is required to indicate whether these close associations are present in patients with spontaneously low iPTH levels without vitamin D treatment.

Oxidised LDL/LDL-cholesterol ratio and coronary artery calcification in haemodialysis patients

BACKGROUND AND AIMS

Serum malondialdehyde-modified low-density lipoprotein (MDA-LDL) and MDA-LDL/LDL-cholesterol (LDL-c) ratio are risk factors for arteriosclerosis and cardiovascular disease (CVD). However, no information is available on these parameters or their associations with coronary artery calcification (CAC) in haemodialysis (HD) patients.

METHODS AND RESULTS

Fifty-seven HD patients and 26 control subjects were included in this cross-sectional study. Serum MDA-LDL concentrations and MDA-LDL/LDL-c ratios were examined. HD patients had significantly higher MDA-LDL/LDL-c ratios than the controls (105.1 ± 27.5 vs. 81.4 ± 18.9 mU/mg, P < 0.001); however, there was no significant difference in serum MDA-LDL levels between the 2 groups. CAC scores were examined only in HD patients and their possible associations with the clinical/laboratory data were analysed. Analysis of HD patients showed that MDA-LDL/LDL-c ratio has an association with presence of CVD, CAC score, HD duration, MDA-LDL, or haemoglobin A1C. In addition, the CAC score was positively correlated with serum MDA-LDL level (P = 0.048) and MDA-LDL/LDL-c ratio (P = 0.006). Furthermore, multivariate logistic regression analysis showed that MDA-LDL/LDL-c ratio (β = 0.04, P = 0.003) and HD duration (β = 0.16, P = 0.007) were independently associated with CAC score.

CONCLUSION

The MDA-LDL/LDL-c ratio of HD patients was significantly higher than that of non-HD subjects and was independently associated with the CAC score. Therefore, this ratio could be an important risk factor for CAC in HD patients.

Effects of long-term treatment with mizoribine in patients with proliferative lupus nephritis

AIM

Mizoribine (MZR) is a purine antimetabolic immunosuppressant agent that has few little severe adverse events. We studied whether maintenance therapy with MZR and prednisolone (PSL) in severe proliferative lupus nephritis patients could improve immunity, reduce proteinuria, prevent renal relapse, and reduce steroid dose.

METHOD

Long-term maintenance therapy with MZR and PSL was evaluated in ten patients with biopsy-proven proliferative lupus nephritis. Patients with severe lupus nephritis, who had proteinuria of 0.5 g or more even after treatments with plasma exchange and/or pulse methyl prednisolone, were recruited. MZR at an average dose of 140 +/- 10 (100 - 200) mg was administered two to three times/day in combination with PSL. The average period for the MZR maintenance therapy was 89.7 +/- 5.5 (70 - 126) months. Urine protein excretion, serum hemolytic complement activity (CH50), C3, serum creatinine, general and biochemical blood examinations, anti-ds-DNA antibody were collected at each monthly medical examination.

RESULTS

All patients were females, mean age 43.0 +/- 3.3 years. A significant decrease in proteinuria was noted two years after the combination therapy (p = 0.0016). Five patients experienced lupus nephritis relapse. Patients who did not experience relapses had their MZR combination therapy initiated earlier (p = 0.037) when compared with the patients who experienced relapses. Serum creatinine levels remained unchanged in all patients throughout treatment and follow-up, even during renal relapses. Levels of C3 and CH50 normalized as proteinuria decreased. None of the patients developed serious side effects during MZR treatment. A significant steroid-sparing effect was observed three years after initiating MZR (p = 0.0025).

CONCLUSION

From our long-term observation, maintenance therapy with low-dose PSL combined with MZR can eliminate proteinuria and have steroid-sparing effect. Early initiation of the therapy can protect against renal relapses among severe proliferative lupus nephritis patients without serious side effects.

[Nonpenetrating traumatic injury of the thoracic aorta and left subclavian artery; report of a case]

Nonpenetrating traumatic injury of the thoracic aorta and/or its major branch is usually fatal and the treatment of this condition carries extremely high risk because of associated visceral organ injuries. Accurate diagnosis have been difficult. However, recently developed multi-slice helical computed tomography (CT) is highly sensitive in early detection of precise location of injury and associating injuries of other organs. Here we report our case with combined thoracic aortic and left subclavian artery injuries, diagnosed by 3-dimensional (3-D) CT and treated successfully.

Serum levels of macrophage colony-stimulating factor and aortic calcification in hemodialysis patients

Hemodialysis (HD) patients have accelerated atherosclerosis. Recent reports have shown that aortosclerosis is more frequently observed in HD patients than in healthy subjects. Macrophage colony-stimulating factor (M-CSF) secreted by activated macrophages may be involved in the process of aortosclerosis in HD patients. To understand the mechanism behind the increased incidence of aortosclerosis in HD patients, we examined the relationships between serum M-CSF levels and aortic calcification index (ACI) estimated by CT scan. A significant increase in serum M-CSF concentrations was found in HD patients (3.8 +/- 0.2 ng/ml) as compared with controls (1.5 +/- 0.1 ng/ml). No significant differences were observed between chronic glomerulonephritis and diabetes mellitus groups of patients. We also found no significant differences between the groups using different membranes (triacetate 3.8 +/- 0.2 ng/ml vs. polysulfone 3.8 +/- 0.4 ng/ml). There was no correlation between serum M-CSF concentrations and clinical parameters such as age, duration of HD, blood pressure, serum concentrations of nitrogen, creatinine, cholesterol, triglyceride, LDL, Ca x P products, and intact parathyroid hormone. A positive correlation was observed between serum M-CSF levels and ACI in HD patients (r = 0.596, p < 0.01). These results suggest that M-CSF may be involved in the process of aortosclerosis in HD patients.

Eugenics in Japan: some ironies of modernity, 1883-1945

Japanese eugenic discourse and institution building contrast sharply with comparable movements elsewhere. As a social-intellectual phenomenon, Anglo-American eugenics considered the Japanese racially inferior to Western peoples; yet eugenic ideals and policies achieved a remarkable popularity in Japan. Most of mainstream Japanese genetics was derived from orthodox Mendelian roots in Germany and (to a lesser degree) the United States. But French-style Lamarckian notions of the inheritability of acquired characters held surprising popularity among enthusiasts of eugenics. Japanese eugenicists could condemn the actions of foreign eugenicists like Charles Davenport in the United States for their efforts to forbid Japanese immigration in the 1920s, yet appeal to these same eugenicists as a source of legitimacy in Japan. These paradoxes can partly be explained against a background of relative isolation in a period of profound social change. Few Japanese eugenicists had close personal contact with foreign eugenicists, and most of their knowledge was acquired through reading rather than direct exposure. The eugenic ideal of ethnic purity was attractive to a society long accustomed to monoracial self-imagery. The need to defend national independence in an era of high imperialism seemed to require the most up-to-date policies and ideas. And Japan's own acquisition of an overseas empire seemed to demand a population management philosophy ostensibly based on scientific principles. These and other forces supported the implementation of eugenic policies and prescriptions among the Japanese people in the first half of the twentieth century.

Ex vivo evaluation of the NASA/DeBakey axial flow ventricular assist device. Results of a 2 week screening test

The authors investigated the antithombogenicity of the NASA/DeBakey axial flow ventricular assist device in an ex vivo calf model. The device is 3 inches in length and 1 inch in largest diameter. The pump weighs 53 g and displaces 15 ml. The unit consists of three major components: a flow straightener, a spinning inducer/impeller, and a diffuser. The impeller has rod shaped permanent magnets embedded within the six blades and is activated magnetically by a motor stator that is positioned outside the flow tube. Previous 2 day screening tests demonstrated an antithrombogenic configuration in short-term implantation. Based on the results of these 2 day screening tests, five pumps with the best configuration were implanted into a calf for 2 weeks for anti thrombogenicity confirmation. Pumps were implanted paracorporeally, and heparin was used to maintain activated clotting time to approximately 250 sec. Each pump was changed every 2 weeks as planned. During the experiment, all pumps demonstrated stable pumping. The required electric power was 7 to 8 watts and pump flow was maintained at 4 L/min. The calf was in excellent condition. Liver and renal function were maintained, plasma free hemoglobin was kept at less than 4 mg/dl (3.3 +/- 0.3 mg/dl), and lactate dehydrogenase was 1043 +/- 36 units/L. In this experimental series, all five pumps passed the 2 week implantation. Two week ex vivo test results indicated very slight thrombus in the hub areas of some pumps. For the next phase of the implantation study, minor design optimization is necessary to completely eliminate thrombus formation. According to our step by step approach, the in vivo test aiming for long-term implantation is ongoing.

[An operated case report of pulmonary aspergillosis by sapprophytic infection of Aspergillus candidus in congenital bronchial cyst of right lower lobe]

Aspergillosis is a mycotic disease caused by a variety of species of the dimorphic fungus aspergillosis, especially aspergillus fumigatus. But the report of pulmonary aspergillosis by aspergillus candidus is very rare. We experienced a surgical case of pulmonary aspergillosis caused by aspergillus candidus. The patient is a 18-year-old girl. Eleven years ago, she had suffered from pneumonia of rt. lower lobe, there after she often has suffered from cough and fever every year. In 1986, chest x-ray photography shows a small cavity in rt. lower lobe. In 1989, it becomes a big cavity of 8 X 8 cm in diameter with niveau. She has cough and bloody sputum of 100-150 ml daily. We have cultured aspergillus candidus from sputum, bloody pus obtained by percutaneous aspiration needle lung biopsy of the cavity and bloody pus in the cavity which was resected on March 3, 1989. But the pathological investigation could not demonstrate any fungus ball or fungus body of aspergillus candidus.

Effects of beta-lactam antibiotics and N-methyltetrazolethiol on the alcohol-metabolizing system in rats

The disulfiram-like effect of various beta-lactam antibiotics containing N-methyltetrazolethiol (NMTT) on the alcohol-metabolizing system was studied using rats. Their administration caused decreased activities in low Km aldehyde dehydrogenase (ALDH) and acetaldehyde oxidation in the liver, with marked depression from several hours to 2 days after the treatment. Blood acetaldehyde level increased markedly when ethanol was administered 18-24 hr after pretreatment with antibiotics. A similar time course change in the effect was obtained when disulfiram was administered. The following results obtained in the present study indicate that the disulfiram-like effect associated with these antibiotics was not mediated by the whole molecular structures of these drugs: Firstly, the antibiotics were eliminated rapidly from the plasma and liver, and the disulfiram-like effect was followed by a disappearance of the drugs. Secondly, the concentration of antibiotics required to inhibit mitochondrial low Km ALDH activity in vitro was very high compared with their liver concentration. Thirdly, rapid onset of disulfiram-like effects occurred after administration of NMTT itself, and a pronounced elevation of blood acetaldehyde level was observed when ethanol was administered 3-5 hr after the NMTT injection. Fourthly, almost the same amounts of NMTT were released in the body after the intravenous administration of various NMTT-containing antibiotics, as judged by the urinary excretion. These results suggest that the disulfiram-like effect of beta-lactam antibiotics is mediated by NMTT released from them.

Pharmacokinetics of latamoxef and N-methyltetrazolethiol in rats associated with the development of disulfiram-like effects

The disulfiram-like effect of beta-lactam antibiotics, having an N-methyltetrazolethiol (NMTT) as a 3'-position substituent of the cephalosporin nucleus, was determined in rats using latamoxef (LMOX) as a model. Intravenous and subcutaneous administrations of these antibiotics caused a decrease in the low Km aldehyde dehydrogenase (ALDH) activity in liver mitochondria and an increase in blood acetaldehyde level during ethanol metabolism, as in the case of disulfiram. When the antibiotic was administered intravenously to biliary fistula rats, the blood acetaldehyde level did not increase. On the other hand, oral administration of antibiotic to normal and biliary fistula rats caused pronounced development of disulfiram-like effects in both animals. When LMOX was injected to normal rats, the rapid and slow eliminations of LMOX and NMTT, respectively, were observed from blood and liver. After oral administration of LMOX, NMTT remained in the blood and liver for a long time with higher concentrations, although LMOX could not be detected in the body. With biliary fistula rats, intravenous injection of LMOX led to rapid urinary excretion of both LMOX and NMTT. These results indicate that the development of disulfiram-like effects of NMTT-containing antibiotics is closely related to the pharmacokinetic profile of NMTT released from its parent drugs.

Effects of beta-lactam antibiotics on the acetaldehyde-metabolizing system in germ-free rats

Effects of several beta-lactam antibiotics on the acetaldehyde-metabolizing system were studied using germ-free rats. Administration of cefamandole (CMD) to the rats caused a decrease in liver mitochondrial low Km aldehyde dehydrogenase activity and an increase in blood acetaldehyde level during ethanol metabolism, similar to the case in conventional rats. Oral administration of CMD produced a pronounced increase in blood acetaldehyde level compared to the subcutaneous administration of the antibiotic. When the animals were given various beta-lactam antibiotics subcutaneously, only the antibiotics having an N-methyltetrazolylthiomethyl group at the 3-position of the cephalosporin nucleus exhibited the disulfiram-like effects on the acetaldehyde-metabolizing system. The results indicate that intestinal bacteria do no participate in the development of the disulfiram-like reaction of several beta-lactam antibiotics.

A comparative study on the effects of disulfiram and beta-lactam antibiotics on the acetaldehyde-metabolizing system in rats

Several beta-lactam antibiotics, especially those containing N-methyltetrazolylthiomethyl groups at the 3-position of the cephalosporin nucleus, affect the alcohol-metabolizing system in rats. These effects were compared those with disulfiram, well-known as a potent inhibitor of aldehyde dehydrogenase (ALDH). Both disulfiram and antibiotics containing the N-methyltetrazolylthiomethyl group inhibited both mitochondrial low Km ALDH and acetaldehyde oxidation in rat livers. The high Km ALDH and alcohol dehydrogenase activities in livers were not affected by these treatments. When ethanol was given to rats pretreated with disulfiram or these antibiotics, the blood acetaldehyde concentration increased markedly concomitant with a decrease in activity of the low Km ALDH. Administration of N-methyltetrazolethiol alone suppressed the low Km enzyme activity and also increased the blood acetaldehyde level; both effects were pronounced and observed several hours after administration. beta-Lactam antibiotics without N-methyltetrazolethiol in their molecule did not affect the liver mitochondrial enzyme activity or the blood acetaldehyde level.

Liver microsomal cytochrome P-450-dependent O-dealkylation reaction in various animals

Liver microsomal O-dealkylation activity was determined using O-methyl, O-ethyl and O-propyl derivatives of p-nitrophenol, 7-hydroxycoumarin (umbelliferon) and 7-hydroxyphenoxazone (resorufin) as substrates. Microsomal O-dealkylation activities of p-nitrophenol and 7-hydroxycoumarin O-alkyl derivatives were of similar levels, but the activities of 7-hydroxyphenoxazone O-alkyl derivatives were very low compared with those of other substrates. Pretreatment of rats with beta-naphthoflavone resulted in the preferential increase of O-deethylation and O-depropylation activities regardless of the ring structure of the substrates, and the ratio of O-deethylation and O-depropylation activities to that of O-demethylation increased markedly. On the other hand, the O-dealkylase activity of all substrates increased generally upon pretreatment of the rats with phenobarbital, but the ratio of O-deethylase or O-depropylase activity to that of O-demethylase in the pretreated rats was not very different from that of the untreated animals. Hexobarbital inhibited competitively the O-dealkylation activity in control and phenobarbital-pretreated rat microsomes. On the other hand, the O-dealkylase activity in microsomes obtained from beta-naphthoflavone-pretreated rats was inhibited remarkably by alpha-naphthoflavone, but not in microsomes prepared from untreated and phenobarbital-pretreated rats. Based on these results, this report discusses the relationship between the alteration of O-dealkylation activity and the composition change of cytochrome P-450 in microsomal membrane. Species differences in the substrate specificity of the O-dealkylation reaction and in the responsiveness of the animals to typical inducers were also observed using liver microsomes obtained from several animals under various conditions.

Biotransformation of coumarin derivatives. (2). Oxidative metabolism of 7-alkoxycoumarin by microsomal enzymes and a simple assay procedure for 7-alkoxycoumarin O-dealkylase

The in vitro biotransformation of 7-alkoxycoumarin by rat liver microsomes was studied to develop a simple and accurate assay procedure for 7-alkoxycoumarin O-dealkylase. 7-Alkoxycoumarin was converted to the O-dealkylated metabolite, 7-hydroxycoumarin, by aerobic incubation of the parent compound with microsomes and NADPH, but the decreased amount of 7-alkoxycoumarin in the reaction mixture was several times higher than that of the 7-hydroxycoumarin produced during the incubation. The thin-layer chromatogram of the ether extractable metabolites in the reaction mixture showed the existence of several fluorescent metabolites including 7-hydroxycoumarin. Fluorescent properties of the parent compound, 7-alkoxycoumarin, and most of the metabolites differed from that of 7-hydroxycoumarin, but the reaction cofactor, NADPH, showed similar properties. Treatment of the reaction mixture with perchloric acid resulted in conversion of NADPH to the non-fluorescent form without any effect upon the fluorescent properties of 7-hydroxycoumarin and its related compounds. Based on these properties, an improved and simple in vitro fluorometric assay of the O-dealkylation of 7-alkoxycoumarin was developed. The method is applicable to routine determination of O-dealkylase activity in both isolated microsomes and whole homogenate. Species differences in the substrate specificity of the O-dealkylation reaction and in the responsiveness of animals to the inducer were observed even with use of the liver homogenate obtained from untreated and phenobarbital- or beta-naphthoflavone-pretreated animals, similar to what was observed with the microsomal system.