Intraoperative hypertensive crisis in a dog with functional paraganglioma of the gall bladder.

A 15-year-old spayed female mongrel presented with anorexia and an abdominal mass. The mass originated from the gall bladder and was surgically resected along with divisionectomy of the central hepatic division. Paroxysmal hypertension and tachycardia were noted during manipulation of the mass. Following resection, arterial blood pressure decreased significantly. Histopathological analysis confirmed a diagnosis of neuroendocrine neoplasm. Immunohistochemical staining for synaptophysin and chromogranin A yielded diffuse and strong positive results, while gastrin was positive in only 10% of the cells. The preoperative elevated concentrations of catecholamine in the urinalysis showed a marked decrease after surgery. Based on these findings, the tumour was diagnosed as a functional paraganglioma of the gall bladder. The patient has undergone regular thoracic radiographs and ultrasound examinations and, until 431 days after surgery, has shown no signs of metastases or recurrences. Based on our literature search, we report the first case of functional paraganglioma of the gall bladder in a dog.

Clinical relationship between histopathological necrotic/partial necrotic findings and disease condition of gallbladder mucoceles in dogs.

Gallbladder mucocele (GM) is a common extrahepatic biliary disease recognized in dogs and is defined as the expansion and extension of the gallbladder by an accumulation of semi-solid bile or bile acid. Histopathological diagnosis of necrotizing cholecystitis and transmural coagulative necrosis of the gallbladder wall shows poor prognosis. Conversely, histopathological diagnosis with partial necrotic findings is often achieved. We hypothesized that histopathological partial necrosis of the gallbladder wall is the primary lesion of necrotic cholecystitis or transmural ischemic necrosis. Therefore, we investigated the relationship between histopathological necrosis/ partial necrosis findings and their clinical conditions. We retrospectively analyzed 55 dogs diagnosed with GM that had undergone cholecystectomy at the Yamaguchi University Animal Medical Center. The group with histopathological necrosis/partial necrosis of the gallbladder wall showed elevated levels of preoperative white blood cells, alanine transaminase, alkaline phosphatase, γ-glutamyltransferase, total bilirubin, and C-reactive protein compared to the non-necrotic group. Partial necrosis of the gallbladder wall may affect the progression of the disease and hematological abnormalities. Additionally, all death cases until 2 weeks were included in the histopathological necrosis/partial necrosis group. In this study, we found that poor prognosis factors were associated with partial necrosis of the gallbladder wall. Furthermore, these cases of partial necrosis showed elevated levels of blood test parameters. These results suggest that necrosis of the gallbladder wall is associated with poor prognosis and poor pathophysiological conditions.

Venous thromboembolisms and rheology in ovarian cancer patients after postoperative adjuvant paclitaxel and carboplatin therapy.

In ovarian cancer patients, chemotherapy can be an independent risk factor for the development of thromboembolic complications, such as venous thromboembolism (VTE). The factors and their values that lead to the development of VTE are remaining unknown in patients undergoing chemotherapy with paclitaxel and carboplatin. This study investigated serial rheological parameters (D-dimer, red blood cell count, hematocrit, and plasma viscosity) for VTE that developed following chemotherapy for ovarian cancer. Forty-eight ovarian cancer patients undergoing chemotherapy were enrolled in this study. A significant difference in the mean values of plasma viscosity and hematocrit was observed between the VTE group (n = 5) and the non-VTE group (n = 43) (P < 0.10). Univariate and multiple regression analyses by stepwise selection identified plasma viscosity as the independent variable associated with VTE development. The VTE incidence was the same as in previous reports. The results support the contention that plasma viscosity could be an index for development of VTE in ovarian cancer after chemotherapy.

Mitochondrial uncoupling reveals a novel therapeutic opportunity for p53-defective cancers.

There are considerable challenges in directly targeting the mutant p53 protein, given the large heterogeneity of p53 mutations in the clinic. An alternative approach is to exploit the altered fitness of cells imposed by loss-of-wild-type p53. Here we identify niclosamide through a HTS screen for compounds selectively killing p53-deficient cells. Niclosamide impairs the growth of p53-deficient cells and of p53 mutant patient-derived ovarian xenografts. Metabolome profiling reveals that niclosamide induces mitochondrial uncoupling, which renders mutant p53 cells susceptible to mitochondrial-dependent apoptosis through preferential accumulation of arachidonic acid (AA), and represents a first-in-class inhibitor of p53 mutant tumors. Wild-type p53 evades the cytotoxicity by promoting the transcriptional induction of two key lipid oxygenation genes, ALOX5 and ALOX12B, which catalyzes the dioxygenation and breakdown of AA. Therefore, we propose a new paradigm for targeting cancers defective in the p53 pathway, by exploiting their vulnerability to niclosamide-induced mitochondrial uncoupling.

Lactobacillus gasseri PA-3 utilizes the purines GMP and guanosine and decreases their absorption in rats.

Excessive intake of purine-rich foods elevates serum uric acid levels, making it a risk factor for hyperuricemia. We hypothesized that lactic acid bacteria ingested with food might utilize purines and contribute to their decreased absorption in the intestines, thereby preventing hyperuricemia. We previously reported that Lactobacillus gasseri PA-3 (PA-3) incorporates adenosine/inosine and related purines and that oral ingestion of PA-3 reduced the absorption of these purines in rats. However, it is unclear whether PA-3 also decreases the absorption of other purines, such as guanosine 5'-monophosphate (GMP) and guanosine. This study investigated whether PA-3 incorporates GMP and guanosine and reduces their absorption in rats. PA-3 incorporated both purines, with 14C-GMP uptake being greater than that of 14C-guanosine. Radioactivity in rat blood was significantly lower 30, 45, and 60 minutes after administration of 14C-GMP plus PA-3 than after administration of 14C-GMP alone and was significantly lower 15 minutes after administration of 14C-guanosine plus PA-3 than after administration of 14C-guanosine alone. PA-3 incorporates GMP and guanosine in vitro. Oral administration of PA-3 with GMP and guanosine reduces the intestinal absorption of these purines in vivo. These findings, together with those of previous studies, indicate that PA-3 reduces the absorption of major purines contained in foods. PA-3 may also attenuate the excessive absorption of dietary purines in humans, protecting these individuals against hyperuricemia.

Arf tumor suppressor disrupts the oncogenic positive feedback loop including c-Myc and DDX5.

Tumor suppressor protein p19(ARF) (Arf; p14(ARF) in humans) functions in both p53-dependent and -independent modes to counteract hyper-proliferative signals caused by proto-oncogene activation, but its p53-independent activities remain poorly understood. Using the tandem affinity purification-tag technique, we purified Arf-containing protein complexes and identified p68 DEAD-box protein (DDX5) as a novel interacting protein of Arf. In this study, we found that DDX5 interacts with c-Myc, and harbors essential roles for c-Myc-mediated transcription and its transforming activity. Furthermore, when c-Myc was forcibly expressed, the expression level of DDX5 protein was drastically increased through the acceleration of protein synthesis of DDX5, suggesting the presence of an oncogenic positive feedback loop including c-Myc and DDX5. Strikingly, Arf blocked the physical interaction between DDX5 and c-Myc, and drove away DDX5 from the promoter of c-Myc target genes. These observations most likely indicate the mechanism by which Arf causes p53-independent tumor-suppressive activity.

Prognostic implications of CEBPA mutations in pediatric acute myeloid leukemia: a report from the Japanese Pediatric Leukemia/Lymphoma Study Group.

CCAAT/enhancer-binding protein alpha (CEBPA) mutations are a favorable prognostic factor in adult acute myeloid leukemia (AML) patients; however, few studies have examined their significance in pediatric AML patients. Here we examined the CEBPA mutation status and clinical outcomes of pediatric AML patients treated in the AML-05 study. We found that 47 (14.9%) of the 315 evaluable patients harbored mutations in CEBPA; 26 cases (8.3%) harbored a single mutation (CEBPA-single) and 21 (6.7%) harbored double or triple mutations (CEBPA-double). After excluding core-binding factor-AML cases, patients harboring CEBPA mutations showed better overall survival (OS; P=0.048), but not event-free survival (EFS; P=0.051), than wild-type patients. Multivariate analysis identified CEBPA-single and CEBPA-double as independent favorable prognostic factors for EFS in the total cohort (hazard ratio (HR): 0.47 and 0.33; P=0.02 and 0.01, respectively). CEBPA-double was also an independent favorable prognostic factor for OS (HR: 0.30; P=0.04). CEBPA-double remained an independent favorable factor for EFS (HR: 0.28; P=0.04) in the normal karyotype cohort. These results suggest that CEBPA mutations, particularly CEBPA-double, are an independent favorable prognostic factor in pediatric AML patients, which will have important implications for risk-stratified therapy.

Permanent genetic resources added to Molecular Ecology Resources Database 1 February 2013-31 March 2013.

This article documents the addition of 142 microsatellite marker loci to the Molecular Ecology Resources database. Loci were developed for the following species: Agriophyllum squarrosum, Amazilia cyanocephala, Batillaria attramentaria, Fungal strain CTeY1 (Ascomycota), Gadopsis marmoratus, Juniperus phoenicea subsp. turbinata, Liriomyza sativae, Lupinus polyphyllus, Metschnikowia reukaufii, Puccinia striiformis and Xylocopa grisescens. These loci were cross-tested on the following species: Amazilia beryllina, Amazilia candida, Amazilia rutila, Amazilia tzacatl, Amazilia violiceps, Amazilia yucatanensis, Campylopterus curvipennis, Cynanthus sordidus, Hylocharis leucotis, Juniperus brevifolia, Juniperus cedrus, Juniperus osteosperma, Juniperus oxycedrus, Juniperus thurifera, Liriomyza bryoniae, Liriomyza chinensis, Liriomyza huidobrensis and Liriomyza trifolii.

Maintenance of the hematopoietic stem cell pool in bone marrow niches by EVI1-regulated GPR56.

Acute myeloid leukemia with high ecotropic viral integration site-1 expression (EVI1(high) AML) is classified as a refractory type of leukemia with a poor prognosis. To provide new insights into the prevention and treatment of this disease, we identified the high expression of EVI1-regulated G protein-coupled receptor 56 (GPR56), and the association of high cell adhesion and antiapoptotic activities in EVI1(high) AML cells. Knockdown of GPR56 expression decreased the cellular adhesion ability through inactivation of RhoA signaling, resulting in a reduction of cellular growth rates and enhanced apoptosis. Moreover, in Gpr56(-/-) mice, the number of hematopoietic stem cells (HSCs) was significantly decreased in the bone marrow (BM) and, conversely, was increased in the spleen, liver and peripheral blood. The number of Gpr56(-/-) HSC progenitors in the G0/G1-phase was significantly reduced and was associated with impaired cellular adhesion. Finally, the loss of GPR56 function resulted in a reduction of the in vivo repopulating ability of the HSCs. In conclusion, GPR56 may represent an important GPCR for the maintenance of HSCs by acting as a co-ordinator of interactions with the BM osteosteal niche; furthermore, this receptor has the potential to become a novel molecular target in EVI1(high) leukemia.

The role of serum adiponectin levels in women with polycystic ovarian syndrome.

PURPOSE OF INVESTIGATION: The aim of this study was to measure serum adiponectin concentrations in women with polycystic ovarian syndrome (PCOS) and to assess possible correlations between adiponectin and the hormonal or metabolic parameters of this syndrome. MATERIALS AND METHODS: Serum adiponectin levels were evaluated in 20 women with PCOS and 22 women without PCOS whose age and body mass index (BMI) matched the patients. The levels of fasting blood glucose, fasting insulin, gonadotropin, and sex steroid hormones were evaluated in both groups. The homeostasis model assessment (HOMA) score was also calculated. The serum adiponectin levels were assayed by enzyme-linked immunoabsorbent assay (ELISA). RESULTS: Serum adiponectin levels were significantly lower in obese women than in normal-weight women, and they were also significantly lower in PCOS patients with HOMA scores greater than 1.7 compared with those with HOMA scores lower than 1.7. When the subjects were divided in two groups based on serum adiponectin levels (> 40 microg/ml, < 40 microg/ml), 65% of patients with PCOS were included in the lower adiponectin group (p < 0.05). In addition, gonadotropin levels were increased, dependent on the adiponectin levels in women with PCOS. CONCLUSION: Adiponectin is regarded as a possible link between adiposity and insulin resistance (IR). From this data, the secretions of gonadotropin are implicated in the levels of adiponectin in women with PCOS. It is suggested that adiponectin may play an important role in the pathogenesis of PCOS.

Effect of pilocarpine on substance P and calcitonin gene-related peptide releases correlate with salivary secretion in human saliva and plasma.

WHAT IS KNOWN AND OBJECTIVE: Pilocarpine, a muscarinic receptor agonist, has been used for the treatment of dry mouth. Salivary glands are supplied with nerve fibres that contain neuropeptides, such as substance P, calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP), which are important modulators of salivation. It is known that measurement of salivary and plasma levels of neuropeptides is useful for assessing the dose-pharmacological effect relationship of drugs. The relationship between the action of pilocarpine and neuropeptides in humans has not been studied. Moreover, studies evaluate the usefulness of drug salivary levels in the pharmacological evaluation of drugs are scarce. The aim of this study was to examine the effects of pilocarpine on the levels of substance P-, CGRP- and VIP-like immunoreactive substances (IS) in saliva and plasma taken in healthy humans. METHODS: Five healthy male subjects participated in this study. Pilocarpine tablet (10 mg) or placebo tablet was orally administered with 100 mL of water. Each subject was administered placebo and drug with an interval of 4 weeks in between. Saliva was sampled before and at 20, 40, 60, 90, 120, 180 and 240 min after administration of the test substances. Venous blood samples (10 mL) were also taken from a forearm vein at each time interval. The samples were then enzyme immunoassayed using a highly sensitive system for substance P-, CGRP- and VIP-IS. The amount of saliva was measured by the Saxon test. RESULTS: A single oral administration of pilocarpine increased the release of salivary substance P-IS (the area under the concentration-time curve: AUC(0→240 min)) compared with the placebo. Pilocarpine also significantly increased the release of salivary CGRP-IS (AUC(0→240 min)). Pilocarpine significantly increased the release of plasma CGRP-IS. The salivary volume correlated with the salivary level of substance P and CGRP-IS (r = 0·84, P < 0·05 and r = 0·59, P < 0·05, respectively). AUC(0→240 min) for substance P-IS in saliva correlated with that for plasma (r = 0·78, P < 0·05). WHAT IS NEW AND CONCLUSION: Pilocarpine increases the release of salivary substance P and CGRP-IS. This suggests that one mechanism by which pilocarpine improves dry mouth is by local stimulation of neuropeptidergic nerves. Moreover, saliva levels of substance P showed good correlation with the plasma levels. The substance P levels in saliva and plasma may be good indicators of the effects of drugs used in dry mouth/xerostomic patients.

Prognostic significance of L-type amino-acid transporter 1 expression in surgically resected pancreatic cancer.

BACKGROUND: The expression of L-type amino-acid transporter 1 (LAT1) is tumour-specific and has been shown to have essential roles in cell growth and survival. However, little is known regarding the clinical significance of LAT1 expression in pancreatic cancer. This study was conducted to determine the prognostic significance of LAT1 expression. METHODS: A total of 97 consecutive patients with surgically resected pathological stage I-IV pancreatic ductal adenocarcinoma were retrospectively reviewed. Tumour sections were stained by immunohistochemistry for LAT1, CD98, Ki-67 and vascular endothelial growth factor (VEGF), and microvessel density was determined by CD34 and p53. RESULTS: L-type amino-acid transporter 1 and CD98 were highly expressed in 52.6% (51/97) and 56.7% (55/97) of cases, respectively (P=0.568). The expression of LAT1 within pancreatic cancer cells was significantly associated with disease stage, tumour size, Ki-67, VEGF, CD34, p53 and CD98. L-type amino-acid transporter 1 expression was confirmed to be a significant prognostic factor for predicting poor outcome by multivariate analysis. CONCLUSION: L-type amino-acid transporter 1 expression is a promising pathological marker for the prediction of outcome in patients with pancreatic cancer.

Role of mineralocorticoid receptor/Rho/Rho-kinase pathway in obesity-related renal injury.

OBJECTIVE: We examined whether aldosterone/Rho/Rho-kinase pathway contributed to obesity-associated nephropathy. SUBJECTS: C57BL/6J mice were fed a high fat or low fat diet, and mice on a high fat diet were treated with a mineralocorticoid receptor antagonist, eplerenone. RESULTS: The mice on a high fat diet not only developed obesity, but also manifested renal histological changes, including glomerular hypercellularity and increased mesangial matrix, which paralleled the increase in albuminuria. Furthermore, enhanced Rho-kinase activity was noted in kidneys from high fat diet-fed mice, as well as increased expressions of inflammatory chemokines. All of these changes were attenuated by eplerenone. In high fat diet-fed mice, mineralocorticoid receptor protein levels in the nuclear fraction and SGK1, an effector of aldosterone, were upregulated in kidneys, although serum aldosterone levels were unaltered. Furthermore, aldosterone and 3ß-hydroxysteroid dehydrogenase in renal tissues were upregulated in high fat diet-fed mice. Finally, in cultured mesangial cells, stimulation with aldosterone enhanced Rho-kinase activity, and pre-incubation with eplerenone prevented the aldosterone-induced activation of Rho kinase. CONCLUSION: Excess fat intake causes obesity and renal injury in C57BL/6J mice, and these changes are mediated by an enhanced mineralocorticoid receptor/Rho/Rho-kinase pathway and inflammatory process. Mineralocorticoid receptor activation in the kidney tissue and the subsequent Rho-kinase stimulation are likely to participate in the development of obesity-associated nephropathy without elevation in serum aldosterone levels.

Immunohistochemical detection of meconium in the fetal membrane, placenta and umbilical cord.

OBJECTIVE: To develop the immunohistochemistry specific for meconium in the placenta, fetal membrane and umbilical cord. STUDY DESIGN: We previously reported the specific presence of zinc coproporphyrin I (ZnCP-I) in human meconium and demonstrated the possible diagnostic use of an elevation in maternal plasma ZnCP-I levels in cases of amniotic fluid embolism. In this study, we developed a new specific monoclonal antibody for ZnCP-I and applied it to the immunostaining of meconium in the placenta, fetal membrane, and umbilical cord. RESULTS: Immunoreactivity of ZnCP-I clearly and specifically identified meconium in the placenta, fetal membrane, and umbilical cord. It was especially useful in cases of severe chorioamnionitis to detect meconium in the macrophages surrounded by numerous neutrophils. In more than half of the cases, meconium was detected in clear amniotic fluid at delivery, suggesting previous exposure. CONCLUSIONS: Immunohistochemical detection of ZnCP-I is a highly sensitive histological diagnosis of meconium.

Multicentric Castleman's disease representing effusion at initial clinical presentation: clinicopathological study of seven cases.

We present here seven cases of idiopathic multicentric Castleman's disease (MCD) showing effusion at the initial clinical presentation. This series includes a high proportion of middle-aged and elderly females (5/7). Various autoantibodies were detected in six cases. Anemia (Hb < 10 g/dl) was detected in four cases, leukocytosis (WBC > 10 × 10(9)/l) in three and thrombycytopenia (<100 × 10(9)/l) in five. Positivity for C-reactive protein or elevated erythrocyte sedimentation rate was recorded in all seven cases. Elevated serum IgG level (>2000 mg/dl) was recorded in only three cases. Elevated serum interleukin-6 level was recorded in all four cases examined. At the onset of disease, four cases were associated with idiopathic thrombocytic purpura. During the course of disease, one case each was diagnosed as systemic sclerosis + Sjögren's syndrome (SJS) and SJS. Histologically, five lesions exhibited a mixed type of Castleman's disease, and one case each exhibited a hyaline-vascular type and plasma cell type. The non-neoplastic nature of the B-lymphocytes was demonstrated by immunohistochemistry and polymerase chain reaction. There were no human herpes type-8 virus-positive cells in any of the seven lesions. Good responsiveness to glucocorticoid therapy has been seen in all six cases treated. From a therapeutic perspective, it is important to discriminate this subtype of MCD.

Role of transcription factors in small intestinal ischemia-reperfusion injury and tolerance induced by ischemic preconditioning.

BACKGROUND: Small intestinal ischemia-reperfusion (I/R) injury, a clinically important condition, induces severe organ damage. Ischemic preconditioning (IPC) produces tolerance to long-term I/R by inducing a short-term I/R. Herein, we have examined the reduction in the extent of injury by IPC. METHODS: Small intestinal I/R injury was induced in rats by clamping the superior mesenteric artery (SMA) for 30 minutes followed by reperfusion for various 30 minutes. The IPC + I/R group underwent a short-term I/R (IPC) prior to long-term I/R. Nuclear factor-κB (NF-κB) activity was analyzed by an electrophoretic mobility shift assay and cytokine mRNA levels, by reverse transcription-polymerase chain reaction. Apoptosis-related genes were analyzed by Western blotting and immunohistochemistry, and apoptotic cells, by TUNEL staining. RESULTS: The animals were subjected to 30 minutes of ischemia followed by 30 minutes of reperfusion. NF-κB activity increased in the I/R group and decreased in the IPC + I/R group. The IPC + I/R group showed decreased cytokine in mRNA levels. Expression of the proapoptotic gene caspase-3 was increased in the I/R and decreased in the IPC + I/R group. Expression of the antiapoptotic gene Bcl-xL was increased in the IPC + I/R group. The number of apoptotic cells was increased in the I/R and decreased in the IPC + I/R group. CONCLUSION: Small intestinal I/R injury was reduced by IPC produced by clamping the SMA; thus, IPC may have potential clinical applications in the future.

Peroral endoscopic myotomy (POEM) for esophageal achalasia.

BACKGROUND: Peroral endoscopic myotomy (POEM) was developed by our group to provide a less invasive permanent treatment for esophageal achalasia. PATIENTS AND METHODS: POEM was performed in 17 consecutive patients with achalasia (10 men, 7 women; mean age 41.4 years). A long submucosal tunnel was created (mean length 12.4 cm), followed by endoscopic myotomy of circular muscle bundles of a mean total length of 8.1 cm (6.1 cm in distal esophagus and 2.0 cm in cardia). Smooth passage of an endoscope through the gastroesophageal junction was confirmed at the end of the procedure. RESULTS: In all cases POEM significantly reduced the dysphagia symptom score (from mean 10 to 1.3; P = 0.0003) and the resting lower esophageal sphincter (LES) pressure (from mean 52.4 mmHg to 19.9 mmHg; P = 0.0001). No serious complications related to POEM were encountered. During follow-up (mean 5 months), additional treatment or medication was necessary in only one patient (case 17) who developed reflux esophagitis (Los Angeles classification B); this was well controlled with regular intake of protein pump inhibitors (PPIs). CONCLUSIONS: The short-term outcome of POEM for achalasia was excellent; further studies on long-term efficacy and on comparison of POEM with other interventional therapies are awaited.

Acute on chronic subdural hematoma as a rare complication in a microscopic polyangiitis patient receiving antithrombotic treatment.

We report a 56-year-old man with microscopic polyangiitis (MPA) who developed acute exacerbation of a chronic subdural hematoma (SDH). Laboratory data demonstrated elevation of myeloperoxidase antineutrophil cytoplasmic antibody (MPOANCA) and rapidly progressing renal dysfunction. Renal biopsy showed crescentic glomerulonephritis (GN) with membranous nephropathy (MN). He was treated with corticosteroids, antithrombotic agents, and an immunosuppressant. One month after initiation of treatment, he had a mild headache. One month later, he developed acute SDH. Although he recovered completely after the operation, he finally died of bacterial infection. On autopsy, a scar of vasculitis was confirmed in the leptomeninges as well as in the kidney and lung. Although SDH is a rare complication in MPA, nephrologists must pay more attention to the initial symptoms before a hematoma attack such as headache, especially in patients using antithrombotic agents.

Vascular calcification and secondary hyperparathyroidism of severe chronic kidney disease and its relation to serum phosphate and calcium levels.

BACKGROUND AND PURPOSE: Various complications consequent on disordered calcium and phosphate homeostasis occur frequently in chronic kidney disease (CKD) patients. Particularly, vascular calcification has high morbidity and mortality rates. There is a clear need for a better CKD model to examine various aspects of this disordered homeostasis. EXPERIMENTAL APPROACH: Oral dosing with adenine induced CKD in rats in only 10 days. Serum calcium, phosphate and parathyroid hormone were measured and calcification in aorta was assessed histologically. The effects of varying phosphorus content of diet or treatment with phosphate binders or active vitamin D(3) on these parameters were examined. KEY RESULTS: After adenine dosing, significant hyperphosphatemia, hypocalcemia and secondary hyperparathyroidism (2HPT) were observed during the experimental period of 15 weeks. Aortic calcification was detected in only some of the animals even at 15 weeks (approximately 40%). Treatment with vitamin D(3) for 18 days, even at a low dose (100 ng x kg(-1), 3-4 times week(-1), p.o), caused aortic calcification in all animals and increases in serum calcium levels up to the normal range. The vitamin D(3)-induced calcification was significantly inhibited by phosphate binders which lowered serum phosphate levels and the calcium x phosphate product, although serum calcium levels were elevated. CONCLUSIONS: These data suggest that rats dosed orally with adenine provide a more useful model for analysing calcium/phosphate homeostasis in severe CKD. Controlling serum calcium/phosphate levels with phosphate binders may be better than vitamin D(3) treatment in hyperphosphatemia and 2HPT, to avoid vascular calcification.