Adrenocortical hypoperfusion detected by contrast-enhanced ultrasound in a dog with trilostane-induced hypoadrenocorticism

A 12-year-old neutered male Chihuahua dog was diagnosed with pituitary-dependent hypercortisolism and treated with trilostane. Eighty-nine days later, the dog showed lethargy accompanied by hyponatraemia and hyperkalaemia. Hypoadrenocorticism due to trilostane was suspected, but the result of the adrenocorticotropic hormone stimulation test was not conclusive. Contrast-enhanced ultrasound showed loss of adrenocortical blood flow in both adrenal glands, indicating adrenocortical hypoperfusion and isolated hypoadrenocorticism. Treatment with fludrocortisone acetate improved the condition and electrolyte abnormalities. Thirteen months later, the dog showed alopecia, and an adrenocorticotropic hormone stimulation test revealed increased cortisol concentration, indicating hypercortisolism recurrence. The dog died due to progressive deterioration 22 months after the initial presentation. Post-mortem examination revealed focally extensive necrosis with marked calcification in the parenchyma of the adrenal glands and regeneration of the cells in the zona fasciculata with severe fibrosis. Adrenocortical hypoperfusion detected by contrast-enhanced ultrasound can support the diagnosis of adrenal necrosis and hypoadrenocorticism.

Timolol maleate, a β blocker eye drop, improved edema in a retinal vein occlusion model

Purpose

To investigate the therapeutic effects of eye drops, namely, timolol maleate, a β-adrenergic receptor antagonist, and latanoprost, a prostaglandin F2α analog, on retinal edema in a murine retinal vein occlusion (RVO) model.

Methods

An RVO model was established using laser-induced RVO in mice, which were administered timolol maleate and latanoprost eye drops several times after venous occlusion. Subsequently, the thickness of the inner nuclear layer (INL) and the expression levels of such genes as Vegf and Atf4, which are stress markers of the endoplasmic reticulum, were examined. Primary human cultured retinal microvascular endothelial cells (HRMECs) were treated with timolol under hypoxic conditions, after which the gene expression pattern was investigated. Importantly, an integrated stress response inhibitor (ISRIB) was used in the RVO model, he known ISRIB, which suppresses the expression of ATF4 in retinal edema.

Results

Increased INL thickness was suppressed by timolol eye drops, as were the expressions of Vegf and Atf4, in the RVO model. However, latanoprost eye drops did not induce any change in INL thickness. In HRMECs, hypoxic stress and serum deprivation increased the Vegf and Atf4 expressions; in response, treatment with timolol suppressed the Vegf expression. Furthermore, the ISRIB decreased the Vegf expression pattern and edema formation, which are associated with RVO.

Conclusions

These results indicate that timolol eye drops may be a potential option for RVO treatment.

ALK5 inhibitor acts on trabecular meshwork cell and reduces intraocular pressure

Intraocular pressure (IOP) is the most important risk factor for the onset and progression of glaucoma. IOP reduction has been proven effective in the treatment of glaucoma. IOP is controlled by the production and outflow of the aqueous humor (AH), and the trabecular meshwork (TM) is the main pathway for AH drainage from the eye. However, there are few conventional IOP-lowering treatments that target TM, and there is a need for such treatments. In this study, we screened for the expression level of fibronectin as an indicator and identified an activin receptor-like kinase (ALK) 5 inhibitor. Western blot analysis showed that SB431542, an ALK 5 inhibitor, reduced fibronectin and α-SMA expression. Moreover, a single dose of the ALK5 inhibitor SB431542 reduced IOP in mice, and the IOP-lowering effect of the ALK5 inhibitor was greater than that of a Rho-associated coiled-coil-containing protein kinase inhibitor (Y-27632). Repeated dosing with ALK5 inhibitor eye drops (once daily) enhanced the murine IOP-lowering effect. Furthermore, ALK5 inhibition decreased the expression of extracellular matrix (ECM) mRNA and suppressed ECM production. These findings suggest that ALK5 inhibitors may contribute to the development of new treatments for glaucoma that target the TM.

The pathological association between the anterior eye segment and the retina in a murine model of neovascular glaucoma

Neovascular glaucoma (NVG) is caused by the formation of new blood vessels in the angle, iris, and cornea in retinal ischemic disease, such as proliferative diabetic retinopathy (PDR) and retinal vein occlusion (RVO), which can reduce the visual acuity. However, the pathophysiological symptoms of NVG are still not well understood because there is no model for the formation of NVG in the angle, iris, and cornea. The aim of this study was to investigate the involvement of NVG during ischemic disease, in a murine model of retinal ischemia. We evaluated the changes of the intraocular pressure (IOP) and pathological symptoms in the anterior eye segment and retina in this model, and the changes in the RNA or protein expression of vascular endothelial growth factor (VEGF) and fibrosis-related factors were analyzed in the retina and cornea by quantitative real-time polymerase chain reaction or western blot, respectively. Furthermore, we examined the changes in IOP after intravitreal injection of an anti-VEGF antibody. First, NVG formed in the retinal ischemic murine model, and the IOP was elevated in mice with NVG formation. Interestingly, VEGF expression was decreased in the retina but increased in the cornea in the murine model of NVG. On the other hand, fibrosis-related factors were increased in the retina and also significantly increased in the cornea in NVG. Moreover, the administration of anti-VEGF antibody immediately after vessel occlusion suppressed the increase in IOP, but administration at 7 days after vessel occlusion accelerated the increase in IOP. These findings suggest that the formation of NVG may be correlated with the pathological symptoms of retinal ischemic disease, via changes in VEGF and fibrosis-related factor expression.

Involvement of endoplasmic reticulum stress in rotenone-induced leber hereditary optic neuropathy model and the discovery of new therapeutic agents

Leber hereditary optic neuropathy (LHON) is caused by mitochondrial DNA mutations and is the most common inherited mitochondrial disease. It is responsible for central vision loss in young adulthood. However, the precise mechanisms of onset are unknown. This study aimed to elucidate the mechanisms underlying LHON pathology and to discover new therapeutic agents. First, we assessed whether rotenone, a mitochondrial complex Ⅰ inhibitor, induced retinal degeneration such as that in LHON in a mouse model. Rotenone decreased the thickness of the inner retina and increased the expression levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and immunoglobulin heavy-chain binding protein (BiP). Second, we assessed whether rotenone reproduces LHON pathologies on RGC-5, a neural progenitor cell derived from the retina. Rotenone increased the cell death rate, ROS production and the expression levels of ER stress markers. During chemical compounds screening, we used anti-oxidative compounds, ER stress inhibitors and anti-inflammatory compounds in a rotenone-induced in vitro model. We found that SUN N8075, an ER stress inhibitor, reduced mitochondrial ROS production and improved the mitochondrial membrane potential. Consequently, the ER stress response is strongly related to the pathologies of LHON, and ER stress inhibitors may have a protective effect against LHON.

Piezo 1 is involved in intraocular pressure regulation

Trabecular meshwork (TM) regulates the intraocular pressure (IOP) through the control of aqueous humor outflow. Previous reports show that TM cells express 11 types of mechanosensitive molecules, including Piezo 1, which sense mechanical stimuli. However, the role of Piezo 1 on TM remains unclear. Thus, in this study, we focused on the Piezo 1 and examined its role in TM cells. Immunostaining showed that Piezo 1 was expressed in mouse TM and human TM cells. Moreover, the eye drops containing Piezo 1 agonist Yoda 1 reduced the IOP in mice, and also reduced fibronectin expression level around the TM. In addition, Piezo 1 activation suppressed human TM cells migration/proliferation, and decreased fibronectin expression level. On the other hand, Piezo 1 activation increased matrix metalloproteinase (MMP)-2 expression responsible for fibronectin degradation. These findings could contribute to the development of new treatments for glaucoma.

Genome-wide DNA methylation analysis identifies promoter hypermethylation in canine malignant melanoma

Canine malignant melanoma is a common cancer with a high mortality rate. Although previous studies have evaluated various aspects of this tumour, the exact mechanism of tumourigenesis remains unknown. Epigenetic mechanisms, such as DNA methylation, have recently gained attention as aetiological factors for neoplasia in humans. This study aimed to analyse genome-wide DNA methylation patterns in canine malignant melanoma based on next-generation sequencing data. A total of 76,213 CpG sites, including 29,482 sites in CpG islands (CGIs), were analysed using next-generation sequencing of methylation-specific signatures, obtained by sequential digestion with enzymes, to compare normal oral mucosal samples from four healthy dogs, four canine melanoma cell lines (3 oral cavity and 1 skin), and five clinical samples of oral canine melanoma. Malignant melanoma showed increased methylation at thousands of normally unmethylated CpG sites in CGIs and decreased methylation at normally methylated CpG sites in non-CGIs. Interestingly, the promoter regions of 81-393 genes were hypermethylated; 23 of these genes were present in all melanoma cell lines and melanoma clinical samples. Among these 23 genes, six genes with "sequence-specific DNA binding" annotation were significantly enriched, including three Homeobox genes-HMX2, TLX2, and HOXA9-that may be involved in the tumourigenesis of canine malignant melanoma. This study revealed widespread alterations in DNA methylation and a large number of hypermethylated genes in canine malignant melanoma.

Ultrafast time-resolved magneto-optical imaging of all-optical switching in GdFeCo with femtosecond time-resolution and a μm spatial-resolution

We developed an ultrafast time-resolved magneto-optical (MO) imaging system with several millidegree resolution of light polarization angle, 100 fs time-resolution, and a micrometer spatial resolution. A CCD camera with about 10(6) pixels is used for detection and MO images with an absolute angle of the light polarization are acquired by the rotating analyzer method. By optimizing the analysis procedure with a least square method and the help of graphical processor units, this novel system significantly improves the speed for MO imaging, allowing to obtain a MO map of a sample within 15 s. To demonstrate the strength of the technique, we applied the method in a pump-and-probe experiment of all-optical switching in a GdFeCo sample in which we were able to detect temporal evolution of the MO images with sub-picosecond resolution.

A glycosylated complex of gadolinium, a new potential contrast agent for magnetic resonance angiography?

A new low-molecular weight dendrimer-like MRI contrast agent (Gd-D1) has been synthesized and characterized in vitro by proton and oxygen-17 relaxometry. Its pharmacokinetic parameters and biodistribution patterns were evaluated on rats. Its in vitro and in vivo properties, that is, the longitudinal relaxivity (defined as the increase of the water proton longitudinal relaxation rate induced by one millimole per liter of Gd-D1) equal to 5.6s(-1)mM(-1) at 20 MHz and 310 K, the elimination half-time equal to 85 min, and its low accumulation in liver and spleen, underline its potential as a blood-pool MRI contrast agent.

Low-level cadmium exposure in Toyama City and its surroundings in Toyama prefecture, Japan, with references to possible contribution of shellfish intake to increase urinary cadmium levels

OBJECTIVES

This study was initiated to examine if exposure to cadmium (Cd) was high also outside of the previously identified Itai-itai disease endemic region in the Jinzu River basin in Toyama prefecture in Japan.

METHODS

Morning spot urine samples were collected in June-August 2004 from 651 adult women (including 535 never-smokers) in various regions in Toyama prefecture, and subjected to urinalyses for cadmium (Cd), alpha1-microglobulin (alpha1-MG), beta2-microglobulin (beta2-MG), N-acetyl-beta-D-glucosaminidase (NAG), specific gravity (SG or sg) and creatinine (CR or cr). Three months later, the second urine samples were collected from those with elevated Cd in urine (e.g., > or =4 microg/g cr), together with answers to questionnaires on shellfish consumption.

RESULTS

The geometric mean (GM) Cd, alpha1-MG, beta2-MG and NAG (after correction for CR) for the total participants were 2.0 microg/g cr, 2.4 mg/g cr, 104 microg/g cr and 2.8 units/g cr, respectively; further analysis with never-smoking cases only did not induce significant changes in these parameters. Analyses of the second urine samples from the high Cd subjects showed that there was substantial decrease (to about a half) in Cd in the 3-month period, and that the decrease was accompanied by reduction in alpha1-MG and NAG (beta2-MG did not show elevation even in the first samples). The urinalysis results in combination with the results of the questionnaire survey suggest that the high urinary Cd was temporary and might be induced by intake of shellfish that is edible whole.

CONCLUSIONS

The overall findings appear to suggest that Cd exposure in Toyama populations (outside of the Itai-itai disease endemic region) was at the levels commonly observed on the coast of the Sea of Japan, and that the Cd level in urine might be modified by the intake of some types of seafood. Further studies are necessary to elucidate the relation of urinary Cd with seafood intake.

Infrared absorption enhancement of C60 by overlaying thin silver island films

Normal-incidence infrared absorption has been observed for silver overlaid C(60) thin films formed on surface-oxidized Si(111) substrates as a function of the silver or C(60) film thickness. The absorption spectra exhibit bands at 1429 and 1180 cm(-1) due, respectively, to the infrared active T(lu) (4) and T(lu) (3) modes of C(60) in multi-layers. Additionally, two bands appear at 1442 and 1370 cm(-1). The former band is caused by activation of the infrared inactive (Raman active) A(g) (2) mode via electron transfer from the silver to adsorbed C(60), and the latter is assigned to the T(1u) (4) mode red-shifted by the charge transfer. These bands are all enhanced in intensity dependent either upon the silver or C(60) thickness, i.e., the largest absorption enhancement is obtained for 25-monolayers-thick silver and 12-nm-thick C(60). Under atomic force microprobe inspection, the average size and height of the islands in the overlaid 25-monolayers-thick silver change with underlying C(60) film thickness. The influence of the C(60) film structure upon the silver film and in turn the absorption intensity is strongly suggested.

Beneficial effect of JTV-803, a new synthetic inhibitor of activated factor X, against both lipopolysaccharide-induced and tissue factor-induced disseminated intravascular coagulation in rat models

We examined whether JTV-803, a specific activated factor X inhibitor independent of antithrombin III (ATIII), is effective against disseminated intravascular coagulation (DIC) in rat models induced by tissue factor (TF) or lipopolysaccharides (LPS). In male Wistar rats, DIC was induced by a 4 h infusion of thromboplastin (3.75 U/kg) or LPS (50 mg/kg). The rats were given JTV-803 (0.3 or 3 mg/kg, bolus intravenously) (JTV-803 groups) or low molecular weight heparin (LMWH groups) (200 U/kg, bolus intravenously) prior to an injection of TF or LPS. The results showed that JTV-803 was dose-dependently effective against DIC in both TF-induced and LPS-induced rat models. This anti-DIC effect of JTV-803 at higher doses was almost equivalent to that of LMWH in both types of DIC. Plasma ATIII activity was more prominent in the group treated with JTV-803 than in that treated with LMWH. None of rats died in the TF-induced DIC model with or without drug administration. On the contrary, seven of 22 rats died (mortality rate, 31.8%) in the LPS-induced DIC model without drug administration. Although the mortality rate of rats induced with LPS and treated with LMWH was quite high (6/16, 37.5%), none of the LPS-induced rats treated with JTV-803 died. These findings suggested that JTV-803 can treat both TF-induced and LPS-induced DIC models, and that this drug has greater potential in preserving ATIII and in improving the prognosis of DIC.

Decreased plasma activity of antithrombin or protein C is not due to consumption coagulopathy in septic patients with disseminated intravascular coagulation

We investigated whether depressed plasma antithrombin and protein C activity, considered as a specific finding of disseminated intravascular coagulation (DIC), is due to consumption coagulopathy in septic patients with DIC. An analysis of hemostatic parameters was performed in 139 septic patients (68 with DIC and 71 without DIC). Plasma activity of antithrombin and protein C tended to be significantly decreased in septic patients with DIC but not in those without DIC (p < 0.001). However, when the septic patients were classified into three groups according to the albumin (or choline esterase) level, no significant differences in antithrombin activity or protein C activity were observed between the patients with and without DIC in any of the subgroups. Notably, neither the plasma activity of antithrombin nor protein C was decreased even in septic patients with DIC who had normal plasma levels of albumin (or choline esterase). No significant correlation was observed between plasma levels of thrombin-antithrombin complex (TAT) and antithrombin activity, or between plasma levels of TAT and protein C activity either in septic patients with DIC or without DIC. It is reasonable to conclude that the markedly reduced plasma activity of antithrombin and protein C is not due to consumption coagulopathy in septic patients with DIC.

Development of the fluorometric ELISA method for determination of alpha1-microglobulinuria in a cadmium-polluted area in Japan

OBJECTIVES

To evaluate the usefulness of a newly developed fluorometric enzyme-linked immunosorbent assay (fluorometric ELISA) method for quantification of alpha1 -microglobulin (alpha1-m, protein HC) in an epidemiological study.

METHODS

Urinary alpha1-m in 37 female inhabitants in a cadmium-polluted area, including seven cases with Itai-itai disease, and ten inhabitants in a non-polluted area in Japan were examined. The alpha1-m was measured by both the fluorometric ELISA and a commercially available enzyme immunoassay (EIA) method to evaluate correlation of the two measurements. Concentration of beta2-microglobulin (beta2-m) was also determined in the same samples.

RESULTS

The detection limit of this method was 3 ng/ml or less of alpha1-m. A significant, high positive correlation was obtained between the alpha1-m concentrations measured with the fluorometric ELISA and that of EIA (r = 0.95, P < 0.0001). A significant association was also shown between the alpha1-m and beta2-m concentrations in the urine samples. The concentrations of urinary alphal-m of the inhabitants in the cadmium-polluted area (mean: 6.21 mg/l, 95% confidence interval (95% CI): 4.06-9.50 mg/l) were significantly higher than those of the reference area (mean: 2.19 mg/l, 95% CI: 1.90-2.67 mg/l). The urinary alpha1-m level of the Itai-itai patients was shown to be highest at 39.63 mg/l (95% CI: 28.27 55.55 mg/l). When the cut-off value of 10 mg/l was employed, alpha1-m had a sensitivity of 100% and specificity of 100% for Itai-itai disease.

CONCLUSION

These results suggest that this fluorometric ELISA is a useful tool to determine urinary alpha1-m in the epidemiological survey of renal tubular dysfunction, especially in the cadmium-polluted area of Japan.

Renal tubular dysfunction in male inhabitants of a cadmium-polluted area in Toyama, Japan--an eleven-year follow-up study

An eleven-year follow-up study was carried out to elucidate the changes in the level of environmental exposure to cadmium (Cd) from rice after soil replacement of polluted paddy fields and these effects on urinary excretion of Cd in male inhabitants of a Cd-polluted area in Toyama, Japan. In addition, the prevalence of renal tubular dysfunction (RTD) was examined to clarify the progress of Cd-induced RTD. One hundred and twenty-seven male inhabitants born between 1914 and 1929 in 11 districts of the Cd-polluted Jinzu River basin and 31 reference subjects in 2 adjacent districts were examined twice in 1985-86 and 1996-97. The geometric means of Cd concentrations in polished rice (Cd-R) in the Cd-polluted areas were 0.18 ppm in 1985 and 0.21 ppm in 1986; these values were significantly higher than those of the reference areas (0.13 ppm in 1985 and 0.12 ppm in 1986). After 11 years, the Cd-R levels were significantly decreased to approximately half (0.08 ppm in 1996, 0.12 ppm in 1997) due to soil replacement of polluted paddy fields, which has been carried out since 1980. The mean Cd levels in urine (Cd-U) were significantly reduced from 7.9 and 9.5 microg/g creatinine in the initial study to 6.9 and 6.8 microg/g creatinine in the follow-up study. However, the prevalence of RTD, which was determined by urinary beta2-microglobulin exceeding 1 mg/g creatinine and urinary glucose exceeding 150 mg/g creatinine, increased from 18 and 23% in the 1985-86 study to 25 and 32% in the 1996-97 study, and a total of 12 new cases (12%) of RTD were found. Whereas, only one subject (4%) in the reference control areas was identified as RTD. Cd-induced RTD was prevalent, progressive and irreversible for male inhabitants of the Cd-polluted Jinzu River basin, although the environmental exposure to Cd through rice was significantly reduced by soil replacement of polluted paddy fields.

An enhanced fibrinolysis prevents the development of multiple organ failure in disseminated intravascular coagulation in spite of much activation of blood coagulation

OBJECTIVES

To investigate the relationship between fibrinolytic enhancement and the development of multiple organ failure (MOF) in disseminated intravascular coagulation (DIC). To detect the useful prognostic index for outcome in DIC.

DESIGN

Case-control study.

SETTING

A department of internal medicine in a university hospital, a clinical division for diagnosis and treatment, mainly of respiratory diseases, hematologic diseases, DIC, and other diseases requiring critical care medicine.

PATIENTS

A total of 69 DIC patients, 31 with MOF.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

The DIC patients with MOF had more elevated levels of tissue plasminogen activator antigen (t-PA) and plasminogen activator inhibitor antigen (PAI), and more depressed levels of plasmin-alpha2 plasmin inhibitor complex (PIC) and fibrin/fibrinogen degradation products than those without MOF, although no significant difference in thrombin-antithrombin complex (TAT) levels was observed. A fibrinolytic enhancement (shown by PIC) was parallel to an activation of blood coagulation (shown by TAT) in DIC patients without MOF, although no such fibrinolytic enhancement was provoked even by much activation of blood coagulation in DIC patients with MOF. Whereas all the patients without MOF were restored from DIC, 14 of 31 patients with MOF were unable to be restored from DIC and died. A significant increase in plasma levels of t-PA and PAI under the condition of sustained hemostatic activation was observed in the patients who died.

CONCLUSION

Enhanced fibrinolysis was considered to be the important defense mechanism in preventing the development of MOF in DIC. The increases in plasma levels of t-PA and PAI were poor prognostic markers in DIC. Further careful study may be useful to clarify whether the fibrinolytic therapy is beneficial in clinical DIC patients with MOF.

All-trans retinoic acid is partially effective against lipopolysaccharide-induced but not against tissue-factor-induced disseminated intravascular coagulation in rat models

All-trans retinoic acid (ATRA) has been introduced to the management of acute promyelocytic leukemia (APL) as a differentiation treatment. This drug not only causes complete remission, but also improves disseminated intravascular coagulation (DIC) without adding anticoagulants in APL. We have attempted to determine whether ATRA is effective against DIC in rat models induced by tissue factor (TF) or lipopolysaccharide (LPS), because the anticoagulant effect of ATRA has been considered to induce thrombomodulin upregulation and TF downregulation on endothelial cells as well as on APL cells. In male Wistar rats, DIC was induced by a 4-h infusion of thromboplastin (3.75 U/kg) or lipopolysaccharide (30 mg/kg). The rats were given ATRA orally each day at a dose of 100 mg/kg per day for 1 week before the injection of TF or LPS in ATRA treatment groups, or given low molecular weight heparin (LMWH) 10 min before the injection of TF or LPS (200 U/kg, bolus intravenously) in LMWH treatment groups. No significant changes in hemostatic parameters or markers of organ dysfunction were caused by the ATRA administration, while DIC was significantly improved by LMWH in the TF-induced model. DIC was significantly improved by both ATRA and LMWH in the LPS-induced model. These findings suggested that ATRA was useful for treating DIC only in the LPS-induced model, and that drug efficacy should be carefully assessed because the agents used to induce DIC considerably influenced the outcome.

Beneficial effect of the active form of vitamin D3 against LPS-induced DIC but not against tissue-factor-induced DIC in rat models

1Alpha,25-dihydroxyvitamin D3 (active form of vitamin D3; vitamin D3) has been reported to induce the upregulation of thrombomodulin and downregulation of tissue factor (TF) on monocytes. The possibility exists that vitamin D3 prevents the development of disseminated intravascular coagulation (DIC). In particular, monocyte TF production plays an important role in the pathophysiology of DIC in septic patients. We have attempted to determine whether vitamin D3 is effective against DIC in a rat model induced by lipopolysaccharides (LPS) (30 mg/kg, 4 h) or TF (3.75 U/kg, 4 h) using selective hemostatic parameters, markers of organ dysfunction and pathological findings (assessment of glomelular fibrin deposition). Vitamin D3 was administered orally each day at a dose of 2.0 mg/kg/day for 3 days, or low molecular weight heparin (LMWH 200 u/kg; i.v.) was given 10 min before the injection of TF or LPS in each treatment group. Vitamin D3 was effective against DIC in the rat model induced by LPS only, whereas LMWH was effective against DIC in both rat models induced by either TF or LPS. The anti-DIC effect of vitamin D3 was equal to (or more potent than) that of LMWH. The results suggested that vitamin D3 was useful for the treatment of LPS-induced DIC, and that the assessment of a drug's efficacy should be done carefully given the markedly different results obtained according to the agents used to induce DIC.

Prednisolone inhibits endotoxin-induced disseminated intravascular coagulation and improves mortality in rats: importance of inflammatory cytokine suppression

In order to determine whether prednisolone has a protective effect against the development of disseminated intravascular coagulation (DIC), we measured the effect of prednisolone on changes in hemostatic parameters and plasma levels of inflammatory cytokines in endotoxin-treated rats. Decreases in platelet count and fibrinogen levels, prolongation of prothrombin time, and increases in the plasma fibrin degradation products and levels of thrombin-antithrombin III (TAT) complex following the administration of endotoxin, all of which are associated with DIC, were significantly suppressed by the administration of prednisolone. Heparin administration significantly suppressed changes in all these parameters except for the decrease in platelet count. The combination of prednisolone and heparin was more effective than either treatment alone. In order to determine whether these effects of prednisolone are correlated with the suppression of inflammatory cytokine production, we examined the relationship between changes in plasma levels of cytokine, the hemostatic parameters listed above, and mortality using a number of intervention regimens designed to alter events of the experimentally induced DIC. Changes in hemostatic parameters associated with DIC following 30 mg/kg per 4 h of endotoxin infusion were significantly suppressed by treatment with 1 mg/kg prednisolone 30 min before beginning endotoxin infusion, followed by administration of 250 U/kg heparin 2 h after the start of endotoxin infusion (prednisolone-endotoxin-heparin regimen). The heparin and prednisolone were administrated subcutaneously. The administration of prednisolone and heparin in the reverse order (i.e. heparin first and prednisolone second: heparin-endotoxin-prednisolone regimen) also suppressed changes in hemostatic parameters, albeit to a smaller degree. Cytokine production was also significantly suppressed by the first treatment, but was not affected by the regimen in which heparin was administered first. Administration of prednisolone alone or heparin alone 30 min before endotoxin significantly reduced the number of renal glomeruli with fibrin thrombi. Plasma levels of creatinine and alanine transferase were reduced only by prednisolone. Increased plasma levels of interleukin-1beta, tissue necrosis factor-alpha and interleukin-6 were suppressed by prednisolone but not by heparin, and there were significant correlations between plasma levels of TAT and cytokines. Prednisolone was more effective than heparin in reducing mortality at 24 h after 100 mg/kg over 4 h of endotoxin infusion (four of 20 versus 15 of 20 deaths for prednisolone and heparin, respectively). These findings suggest that prednisolone inhibits the development of endotoxin-induced DIC and reduces mortality by a different mechanism than heparin, possibly through suppressing the production of inflammatory cytokines. Prednisolone may be efficacious in preventing DIC and multiple organ dysfunction caused by endotoxin.

[A follow-up study on renal tubular dysfunction in women living in the cadmium-polluted Jinzu River basin in Toyama, Japan. Part 1. Changes in the level of exposure to cadmium after soil replacement of polluted paddy fields and the related effects on the prognosis of renal tubular dysfunction]

A follow-up study on renal tubular dysfunction was carried out on 193 female inhabitants of the cadmium (Cd)-polluted Jinzu River basin and 40 reference subjects living in an adjacent area in 1994-95. They were 54 to 70 years old when the initial examination was conducted in 1983-84. In the Cd-polluted Jinzu River basin, extensive reclamation of polluted rice fields has been conducted since 1979; as a result, the average Cd concentrations in polished rice consumed by the subjects in the 1994-95 study (0.12 ppm in 1994, 0.14 ppm in 1995) were significantly lower than those in the 1983-84 study (0.26 ppm in 1983, 0.29 ppm in 1984). The average Cd levels in urine in the follow-up study (7.5 micrograms/g Cr. in 1994, 7.7 micrograms/g Cr. in 1995) were also significantly lower than those in the initial study (13.5 micrograms/g Cr. in 1983, 13.3 micrograms/g Cr. in 1984). However, the mean values for urinary excretion of beta 2-microglobulin (beta 2-m) (3.9 mg/g Cr. in 1994, 3.7 mg/g Cr. in 1995) and glucose (203 mg/g Cr. in 1994, 251 mg/g Cr. in 1995) in the follow-up study were significantly higher than those obtained at the initial examination (2.0 mg/g Cr. and 125 mg/g Cr. in 1983 and 1.1 mg/g Cr. and 78 mg/g Cr. in 1984 for beta 2-m and glucose excretion, respectively). The magnitude of increase in urinary excretion of beta 2-m and glucose in inhabitants of the Cd-polluted area was significantly higher than that of the inhabitants of the reference area. Moreover, an increase was observed in the prevalence of renal tubular dysfunction determined by urinary beta 2-m exceeding 10 mg/g creatinine and urinary glucose exceeding 150 mg/g creatinine only among inhabitants of the Cd-polluted area; it is noteworthy that 31 new cases of renal tubular dysfunction were observed in the follow-up study. These results indicate that renal tubular dysfunction among inhabitants of the Cd-polluted Jinzu River basin is irreversible and progressive, and many new cases of renal tubular dysfunction were also noted over a period of 11 years, despite the fact that Cd exposure had decreased over the past 11 years.

Treatment of disseminated intravascular coagulation (DIC) with all-trans retinoic acid in an endotoxin-induced rat model

Anticoagulant drugs such as heparin are often administered to patients with disseminated intravascular coagulation (DIC) who are also being treated for their underlying disease. The pathophysiology of DIC is so varied that treatment with medications other than anticoagulants may be useful. All-trans retinoic acid (ATRA), which is used for the treatment of acute promyelocytic leukemia (APL), improves DIC in APL. In vitro studies have reported that ATRA caused downregulation of tissue factor and upregulation of thrombomodulin (TM) on endothelial cells as well as APL cells. We examined the effect of ATRA in an endotoxin-induced rat DIC model. DIC was induced in male Wistar rats with a 4-h sustained infusion of endotoxin at a dose of 30 mg/kg. ATRA (20 mg/day) was given every day for 1 week before the injection of endotoxin. ATRA improved the increase in thrombin-antithrombin III (TAT) complex and D-dimer in this model. Fibrin deposition in renal glomeruli was inhibited by ATRA administration, with an increase in the intensity of immunohistochemical TM staining. These findings suggest that ATRA has beneficial effects in the endotoxin-induced rat DIC model. The mechanism may be an upregulation of TM expression on endothelial cells.

Prothrombin fragment 1 + 2 measures treatment effect in patients with antiphospholipid syndrome

Antiphospholipid syndrome (APS) is characterized by recurrent thrombosis. The anticoagulant management of APS thrombosis remains controversial. Few reports on markers of in vivo activation of coagulation have been reported. To determine whether plasma levels of prothrombin fragment 1 + 2 (F1 +2) correlate with thrombotic risk and treatment effect in patients with APS, plasma F1 + 2 levels were followed in 57 patients with this syndrome for more than 2 years. Clinical findings were also observed in these patients. Plasma levels of F1 + 2 in patients with APS were significantly higher when compared with control subjects (p<.05). These results suggest patients with APS are in a hypercoagulable state. Plasma levels of F1 + 2 significantly decreased following treatment with either aspirin, or aspirin plus warfarin (p<.05 and p<.01, respectively). Recurrent thromboses or spontaneous abortions occurred in all eight patients whose plasma levels of F1 + 2 remained higher than 1 nmol/l after treatment with either aspirin alone or no anticoagulants. These patients were subsequently treated with warfarin as well as aspirin, and plasma levels of F1 + 2 decreased to less than 1 nmol/l, with no additional thrombotic events over the remainder of the 2-year follow-up. No fatal bleeding was observed in treated patients. Our results suggest plasma levels of F1 + 2 are useful indicators of successful treatment. It is also suggested that warfarin plus mini-dose aspirin therapy is effective for patients with APS to protect from recurrent thromboses without harmful side effects. Further, prospective cohort studies are needed to substantiate these associations.

Increased plasma levels of free tissue factor pathway inhibitor in patients with Graves' disease

Tissue factor pathway inhibitor (TFPI) is present in a free-form and in lipoprotein-associated forms in plasma. In this study, the plasma concentrations of total TFPI (tTFPI) and free-form TFPI (fTFPI) were measured in 25 patients with Graves' disease and 25 age-matched healthy subjects, and the relationship between thyroid state and plasma TFPI was examined. Plasma concentrations (median) of tTFPI and fTFPI in Graves' patients who were hyperthyroid were significantly increased compared with Graves' patients who were euthyroid (152 ng/ml versus 124 ng/ml, p < 0.01 and 41.3 ng/ml versus 20.2 ng/ml, p < 0.0001, respectively), and control subjects (152 ng/ml versus 96 ng/ml, p < 0.0001 and 41.3 ng/ml versus 18.7 ng/ml, p < 0.0001, respectively). There was no significant difference in plasma fTFPI concentrations between the euthyroid group and the control group. Plasma fTFPI concentrations correlated closely with thyroid hormone (T3) levels in the patients (r = 0.559, p < 0.005). Serial measurement of individual patients revealed that plasma concentrations of fTFPI and tTFPI were significantly decreased, reaching normal control values upon attainment of euthyroidism. In conclusion, the close correlation between plasma fTFPI and serum thyroid hormone levels suggests that thyroid hormones might influence the synthesis or metabolism of TFPI on the surface of endothelial cells in patients with Graves' disease. This is the first report concerning high concentrations of plasma tTFPI in patients with hyperthyroidism.

[Analysis of behaviors of plasma tissue factor and tissue factor pathway inhibitor in patients with various diseases]

We measured plasma levels of tissue factor (TF), total tissue factor pathway inhibitor (TFPI) and free TFPI antigen in patients with diabetes mellitus (DM), hyperlipidemia and disseminated intravascular coagulation (DIC). The mean TF, total TFPI and free TFPI antigen concentrations were significantly higher in patients with DM than in controls and the plasma TF concentration was significantly higher in patients with retinopathy or nephropathy than in DM with no complications. The mean TF, total TFPI and free TFPI antigen concentrations were significantly higher in patients with hyperlipidemia than in controls. There was a significant positive correlation between levels of total TFPI and total cholesterol. In patients with hyperlipidemia, the level of total TFPI was significantly decreased compared to base line level by cholesterol lowering drug, however, free TFPI concentration did not change by cholesterol lowering drug. The TF and total TFPI concentrations were significantly higher in patients with DIC than in controls.

Hypercoagulability and high lipoprotein(a) levels in patients with aplastic anemia receiving cyclosporine

There is some clinical evidence that cyclosporine A (CyA) is associated with thrombotic complications of bone marrow and renal transplantation. We investigated plasma concentrations of lipoprotein(a) [Lp(a)], a potentially atherothrombotic lipoprotein, and hemostatic and vascular status in ten patients with aplastic anemia receiving CyA, eleven patients not taking it, and 38 age-matched healthy controls. Patients receiving CyA had significantly higher concentrations of plasma fibrinogen (P < 0.05), prothrombin fragment 1 + 2 (F1 + 2; P < 0.05), plasminogen activator inhibitor-1 (PAI-1; P < 0.05), and von Willebrand factor antigen (P < 0.05) than did patients not taking CyA. Plasma concentrations of Lp(a) were higher in CyA-treated patients than those not receiving it (P < 0.05) or healthy controls (P < 0.05). The difference in the Lp(a) concentration between controls and patients who did not receive CyA-treatment was not significant. Our results suggest that hypercoagulability is likely to occur during CyA therapy. Further, the presence of high concentrations of Lp(a) may accelerate the process of atherosclerosis and increase thrombotic events in patients receiving long-term CyA.

Protective effects of DX-9065a, an orally active, novel synthesized and selective inhibitor of factor Xa, against thromboplastin-induced experimental disseminated intravascular coagulation in rats

We investigated the protective effects of DX-9065a, an orally active, newly synthesized, and specific inhibitor of factor Xa, against experimental disseminated intravascular coagulation (DIC) in rats. Experimental DIC was induced by a 4 hour sustained infusion of thromboplastin at a dose of 2.5 mg/kg. The rats were orally administered DX-9065a at 10, 30, 100 mg/kg 30 minutes before thromboplastin injection. In this DIC model, DX-9065a showed a protective effect against DIC, at all doses and in all parameters, including fibrin(ogen) degradation products, fibrinogen level, thrombin-antithrombin III complex level, prothrombin time (PT), activated partial thromboplastin time (APTT), platelet count, and the number of renal glomeruli with fibrin thrombi. When DX-9065a was orally administered at 100 mg/kg without thromboplastin, no significant changes were seen in hemostatic parameters except PT and APTT, and no fibrin thrombi or abnormal bleeding were seen in renal specimens. These findings suggested that the new oral anti-Xa drug, DX-9065a, has a protective effect against thromboplastin-induced DIC model with little risk of bleeding.

Hypercoagulability and high lipoprotein(a) levels in patients with type II diabetes mellitus

Diabetes mellitus is associated with disturbances in hemostasis that could contribute to the development of diabetic vascular disease. We investigated the changes in parameters of blood coagulation and the fibrinolytic system and in plasma levels of lipoprotein(a)(Lp(a)) in 124 patients with type II diabetes mellitus and 44 healthy control subjects matched for age and body mass index (BMI) to determine whether hemostatic disturbances may lead to increased cardiovascular mortality. Median levels of fibrinogen (P < 0.0001), thrombin-antithrombin III complex (TAT) (P < 0.005), and plasminogen activator inhibitor-1 (PAI-1) activity (P < 0.05) in plasma were significantly elevated in diabetic patients compared with controls. The median concentration of Lp(a) was significantly higher in diabetic patients than in normal controls (18.2 vs. 12.6 mg/dl. P < 0.0005). Lp(a) levels tended to be elevated in patients with a prolonged history of diabetes. There was no evidence that Lp(a) levels were affected by metabolic control or by type of treatment. Twenty-two diabetics with coronary heart disease (CHD) had significantly higher levels of fibrinogen (P < 0.05), TAT (P < 0.05), and Lp(a) (24.7 vs. 13.7 mg/dl, P < 0.01) than the 51 patients without diabetic angiopathy. Our data indicate that impaired hemostatic balance in diabetes may cause hypercoagulability and may thus contribute to the increased cardiovascular mortality in diabetes.

Cross-sectional assessment of renal function in the inhabitants of a cadmium-polluted area

To understand the development of cadmium (Cd)-induced renal tubular dysfunction, cross-sectional assessment of renal function in the inhabitants of the Cd-polluted Jinzu River basin in Toyama, Japan, was carried out. Sixty-seven men and 78 women, aged 56 to 71 years whose urinary beta 2-microglobulin (beta 2-m) exceeded 1,000 micrograms/g creatinine, were examined and divided into five groups according to their values of fractional excretion of beta 2-m (FE beta 2-m). Comparisons were made between six groups including the inhabitants of a non-polluted area as a reference group. Significantly increased values of fractional excretion of urate (FEUA), calcium (FECa), sodium (FENa), and chloride (FECl), serum creatinine and beta 2-m, and urinary protein were detected even in the subjects with FE beta 2-m level below 1 percent compared with the reference group. Fractional phosphate reabsorption (percent TRP) was significantly decreased in the subjects with FE beta 2-m level above 10 percent. Creatinine clearance (CCr) decreased with increase in FE beta 2-m, and the subjects with FE beta 2-m above 30 percent showed significantly decreased CCr values compared to those with FE beta 2-m below 30 percent. In summary, FEUA, FECa, FENa, and FECl, as well as low-molecular-weight proteins such as beta 2-m, are increased in the early stage of Cd-induced renal tubular dysfunction. Although percent TRP was maintained by the decreased CCr, there was a marked decrease in percent TRP in subjects with progressive stage showing FE beta 2-m level above 10 percent. No sex difference in renal tubular dysfunction was found in this cross-sectional study.

Haemostatic and fibrinolytic parameters in septic patients with leukopenia or leukocytosis

Induction of leukocytopenia by cytotoxic drugs protects against the generalized Shwartzman reaction induced by endotoxin. To elucidate the relationship between leukocyte number and in haemostatic and fibrinolytic disturbances in human sepsis, we studied 32 septic patients with abnormal leukocyte counts. Twenty patients had sepsis in the setting of leukopenia after chemotherapy for haematological malignancies. Twelve patients with leukocytosis developed sepsis associated with benign disorders. Concentrations of thrombin-antithrombin III complex (TAT), plasminogen activator inhibitor-1 (PAI-1) and plasma thrombomodulin (TM) in the leukocytosis group of (12.0 +/- 11.0, 40.2 +/- 27.0 and 5.5 +/- 2.3 ng/ml, respectively) were significantly elevated compared to the leukopenia group of (3.8 +/- 2.3, 18.0 +/- 15.0 and 3.1 +/- 1.0 ng/ml, respectively) and controls (3.3 +/- 0.4, 10.5 +/- 5.3, 3.0 +/- 0.5 ng/ml, respectively). On the other hand, there were no significant differences in these values between leukopenia group and controls. Thus leucocytes may play important roles in thrombin generation, PAI-1 release and injury to endothelial cells.

Recombinant hirudin for the treatment of disseminated intravascular coagulation in patients with haematological malignancy

The purpose of this pilot study was to determine the effect of recombinant hirudin (r-hirudin) on coagulopathy and the relationship between concentrations of thrombin-antithrombin III (ATIII) complex (TAT) and thrombin-hirudin complex (THC) in patients with disseminated intravascular coagulation (DIC). Five patients with haematological malignancy associated with DIC were studied. r-Hirudin was administered by continuous intravenous infusion at a dose of 0.005 mg/kg/h for 4-9 days to each patient. Fibrin/fibrinogen degradation products (FDP), D-dimer, TAT and plasmin-alpha 2 antiplasmin complex (PAP) concentrations decreased after treatment with r-hirudin in four patients studied. However, in one patient, serum creatinine increased to 1.7 mg/dl and aPTT was prolonged to 74.4s. Statistical analysis disclosed significant positive correlations between plasma concentrations of hirudin and THC, and between concentrations of THC and TAT. The concentrations of THC were much higher than those of TAT. In conclusion, these findings indicate that r-hirudin more strongly inhibited thrombin than did ATIII without heparin, and that administration of r-hirudin to renal insufficiency required individual adjustment of dosage. The present findings also suggest that r-hirudin can be considered a new agent for the treatment of DIC.

Relationship between elevation in the plasma concentration of elastase-alpha 1 proteinase inhibitor complex (E-alpha 1 PI) and haemostatic parameters during haemodialysis

To investigate the relationship between changes in plasma concentrations of polymorphonuclear elastase (PMN-E) and haemostatic effects during haemodialysis (HD), changes in the plasma concentrations of elastase-alpha 1 proteinase inhibitor complex (E-alpha 1 PI) and fibrinogen (Fbg), cross-linked fibrin degradation products (XDP), thrombin-antithrombin III complex (TAT), plasmin-alpha 2 plasmin inhibitor complex (PIC) and soluble thrombomodulin (TM) in 49 patients with end-stage chronic glomerulonephritis maintained on chronic HD were measured. Plasma concentrations of TAT, PIC, TM and E-alpha 1 PI significantly increased during a single HD. There was a statistically significant correlation between change in plasma E-alpha 1 PI concentration and changes in plasma concentrations of TAT, PIC and TM during a single HD, as well as between changes in plasma concentrations of TM and TAT during a single HD. These observations suggested that activation of coagulation and fibrinolysis, endothelial cell damage, and activation of polymorphonuclear cells occur during HD. Activation of polymorphonuclear cells may induce activation of coagulation and fibrinolysis, leading to endothelial cell damage, augmented by release of proteases such as elastase.

Hypoproduction of erythropoietin contributes to anemia in chronic cadmium intoxication: clinical study on Itai-itai disease in Japan

Itai-itai disease is a condition caused by long-term exposure of the inhabitants of Toyama prefecture, Japan, to cadmium intoxication. The characteristic clinical features of this disease include renal tubular dysfunction, osteomalacia, and anemia. In order to clarify the pathogenesis of the anemia, the red blood cell count, hemoglobin concentration, hematocrit, serum iron level, total iron-binding capacity, serum ferritin level, serum erythropoietin level, creatinine clearance, fractional excretion of beta 2-microglobulin, and bone marrow morphology were determined in ten patients with Itai-itai disease. Low serum iron or ferritin levels were not observed, and bone marrow aspiration did not reveal any specific hematological disorders. A close relationship was observed between the decrease in the hemoglobin level and the progression of renal dysfunction. Low serum erythropoietin levels were detected despite the presence of severe anemia. These results suggest an important role of renal damage in the anemia which develops in Itai-itai disease.

Study of the balance between coagulation and fibrinolysis in disseminated intravascular coagulation using molecular markers

Plasma levels of thrombin-antithrombin III complex (TAT), plasmin-alpha 2-plasmin inhibitor complex (PIC) and active plasminogen activator inhibitor (PAI) were assayed in 66 cases of disseminated intravascular coagulation (DIC). Significant elevation of both TAT and PIC was observed in all cases of DIC. Most elevated levels of TAT were seen in DIC with acute promyelocytic leukaemia (APL) and sepsis. The highest levels of PIC were seen in DIC with APL but were much lower in sepsis. A significant elevation in active PAI was observed in DIC due to acute leukaemia (apart from APL), chronic myeloid leukaemia and sepsis, but not in APL, non-Hodgkin lymphoma and cancer. Active PAI was higher in patients with multiple organ failure (MOF) than in those without MOF while PIC was lower in patients with this complication. Thus, the balance of coagulation and fibrinolysis varied according to the underlying cause of DIC; APL had more dominant activation of fibrinolysis, while sepsis had greater activation of coagulation. It is suggested that the inhibition of secondary fibrinolytic activation plays an important role in the progression of MOF by the disturbance of the microcirculation.

Effects of DX-9065a, an orally active, newly synthesized and specific inhibitor of factor Xa, against experimental disseminated intravascular coagulation in rats

We investigated the protective effects of DX-9065a, an orally active, newly synthesized and specific inhibitor of factor Xa, against two kinds of experimental disseminated intravascular coagulation (DIC) in rats. Endotoxin-induced experimental DIC was induced by a 4-h sustained infusion of endotoxin at a dose of 100 mg/kg. Thromboplastin-induced experimental DIC was induced by a bolus injection of thromboplastin at a dose of 150 mg/kg. The rats were orally administered DX-9065a at 10, 30 or 100 mg/kg 30 min before endotoxin or thromboplastin injection. In both DIC models, DX-9065a showed a protective effect against DIC, at all doses and in all parameters, including fibrin/fibrinogen degradation products (FDP), fibrinogen level, prothrombin time, activated partial thromboplastin time, platelet count and the number of renal glomeruli with fibrin thrombi. When DX-9065a was orally administrated at 100 mg/kg without endotoxin or thromboplastin, no significant changes were seen in hemostatic parameters except PT and APTT, and no fibrin thrombi or abnormal bleeding were seen in renal specimens. These findings suggest that the new oral anti-Xa drug, DX-9065a, has an effect in reducing the severity of DIC. However, further dose-finding and safety studies of this drug have still to be assessed.

Serum bone-type alkaline phosphatase activity in women living in a cadmium-polluted area

To clarify the significance of elevated serum total alkaline phosphatase activity (t-ALP) in persons exposed to environmental cadmium (Cd), the fraction of ALP originating from bone (b-ALP) was assayed using a wheat-germ agglutinin method in 23 men and 20 women in a Cd-polluted area who showed excessive urinary beta 2-microglobulin excretion, and in 21 men and 44 women in a non-polluted area, in addition to 7 patients with itai-itai disease. The fraction of b-ALP increased linearly with the increase in t-ALP in the women, irrespective of Cd-exposure. Elevations of both t-ALP and b-ALP in the Cd-exposed women, including inhabitants of the Cd-polluted area and patients with itai-itai disease, were found with decreases in serum calcium and bone density. It is concluded that elevated serum ALP levels found in Cd-exposed persons reflect the development of Cd-induced bone damage.

Plasma levels of lipoprotein(a) are elevated in patients with the antiphospholipid antibody syndrome

The mechanisms underlying clinical abnormalities associated with the antiphospholipid antibody syndrome (APAS) have not been elucidated. We measured plasma levels of lipoprotein(a) [Lp(a)], the active form of plasminogen activator inhibitor (active PAI), thrombin-antithrombin III complex (TAT) and soluble thrombomodulin (TM), to investigate the relationship of these factors to thrombotic events in APAS. Mean plasma levels of Lp(a), TAT, active PAI and TM were all significantly higher in patients with aPL than in a control group of subjects. Plasma levels of Lp(a) and active PAI were significantly higher in patients with aPL and arterial thromboses than in patients with aPL but only venous thromboses. There was a significant correlation between plasma levels of Lp(a) and active PAI in patients with aPL. These findings suggest that patients with aPL are in hypercoagulable state. High levels of Lp(a) in plasma may impair the fibrinolytic system resulting in thromboses, especially in the arterial system.

[Abnormalities of calcium, phosphorous and vitamin D metabolism with proximal renal tubular dysfunction in subjects environmentally exposed to cadmium]

Calcium, phosphorus and vitamin D metabolism were examined in 21 male and 13 female subjects with renal tubular dysfunction in the cadmium-polluted Jinzu River basin in Toyama prefecture, Japan. Multiple proximal renal tubular dysfunction was detected in all subjects showing increased FE beta 2-m and FFua, generalized aminoaciduria and renal glucosuria. Reduced ability of tubular reabsorption of phosphate resulted in hypophosphatemia in 31% of the women. Despite decreased tubular reabsorption of calcium, the level of serum calcium remained normal in all subjects. Serum 1,25-dihydroxyvitamin-D [1,25(OH)2D], which is produced in the proximal tubules through 1 alpha-hydroxylation from 25-hydroxyvitamin-D [25OHD], was normal or increased to more than 60pg/ml. The serum level of 1,25(OH)2D was inversely related to creatinine clearance in both the men (p < 0.05) and women (p < 0.01). Serum iPTH was slightly increased to more than 0.9 mg/ml, whereas the levels of other hormones, including 25OHD, calcitonin, thyroxine (T4) and triiodothyronine (T3) were normal. The serum alkaline phosphatase activity and serum osteocalcin concentration were significantly increased compared to those of controls in both sexes. Bone loss detected by the measurement of bone density was prominent in female subjects. These results support the hypothesis that the serum phosphate concentration is more important than the serum concentration of 1,25(OH)2D for abnormalities of bone metabolism in cadmium-induced renal tubular dysfunction.

Preliminary study on serum levels of 1,25-dihydroxyvitamin D and 25-hydroxyvitamin D in cadmium-induced renal tubular dysfunction

Serum 1,25-dihydroxyvitamin D [1,25(OH)2D] and 25-hydroxyvitamin D [25(OH)D] were measured in 7 women living in a cadmium-polluted area in Toyama, Japan. Despite the fact that these subjects had severe proximal renal tubular dysfunction showing increased fractional excretion of beta 2-microglobulin (FE beta 2-m) ranging from 9.7-49.1% with a mean of 30.7%, the levels of serum 1,25(OH)2D, which is produced in the proximal tubules, were within the normal range in 6 subjects. Significant correlations were found between 1,25(OH)2D and creatinine clearance (r = 0.802, P less than 0.05), and FE beta 2-m (r = -0.829, P less than 0.05), respectively. These results suggest that renal production of 1,25(OH)2D decreases with progression of cadmium-induced renal tubular dysfunction.

[Evaluation of qualitative and quantitative tests for proteinuria and glucosuria as screening tests for cadmium-induced renal tubular dysfunction]

To evaluate the screening tests for cadmium-induced renal tubular dysfunction, qualitative and quantitative tests for urinary protein and glucose have been done in 146 urine samples obtained from subjects who had lived in the cadmium-polluted Jinzu River basin in Toyama Prefecture, Japan. The subjects consisted of 66 men and 80 women aged 55 to 71 years with beta 2-microglobulinuria exceeding 1,000 micrograms/g creatinine. The results obtained from this study were as follows; 1) The positive reaction (above 1+) for protein by the dipstick method was seen in 19.7% of men and 20.0% of women, and for glucose using Tes-tape in 48.5% of men and 33.8% of women. 2) The geometric means of protein and glucose concentrations in urine were 16.4 mg/dl and 12.7 mg/dl in men, and 14.2 mg/dl and 6.8 mg/dl in women, respectively. 3) The criteria of the primary screening in the health survey system for the residents in cadmium-contaminated areas conducted by the Japan Environment Agency were a proteinuria level exceeding 10 mg/dl and a glucosuria above (+/-) with Tes-tape. Nearly all subjects with urinary beta 2-microglobulin exceeding 30 mg/g creatinine were screened by these criteria in both sexes, whereas only 52.9% of men and 30.0% of women who had urinary beta 2-microglobulin between 10 to 30 mg/g creatinine could be screened in this manner. These results indicate that semiquantitative tests are insufficient as initial tests for screening cadmium-induced renal tubular dysfunction.