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Vascular calcification is an important complication that worsens the prognosis for dialysis patients, although its detailed molecular mechanisms are still unknown.We produced a rat model for vascular calcification with hyperphosphatasemia and hyperparathyroidism, performing a 5/6 nephrectomy and providing a high-phosphorus, low-calcium diet for eight weeks. We examined mRNA obtained from the calcified aortae using microarray analysis, and searched for alterations in gene expression specifically in the calcified lesions.Medial calcification was demonstrated in the abdominal aorta of 12 out of 42 hyperparathyroidism rats. In the aortae of hyperparathyroid rats with vascular calcification, the genes for heparan sulfate proteoglycans, including perlecan, were found to be down-regulated using microarray analysis and real time PCR. Immunohistochemistry also demonstrated reduced production of perlecan in the aortae of hyperparathyroid rats.Perlecan is a major component of the vascular wall basement membrane and may play a role in protecting vascular smooth muscle cells from inflammatory cells and various toxins. It has also been reported that heparan sulfate chains may inhibit osteogenesis. Our findings indicate that perlecan may protect vascular smooth muscle cells from various factors that promote vascular calcification.It may be that reduced expression of perlecan in the calcified aortae of hyperparathyroid rats is a risk factor for vascular calcification.

Background: Fibroblast growth factor 23 (FGF23) regulates renal phosphate reabsorption and 1α,25-dihydroxyvitamin D [1,25(OH)2D3] metabolism. Patients with chronic kidney disease (CKD) have increased levels of circulating FGF23, but the direct regulation of this elevation of FGF23 is incompletely understood. Method:We measured plasma parameters in uremic rats fed a high-phosphorus diet and then performed parathyroidectomy (PTX) to determine its effect. We also investigated FGF23 mRNA expression in various tissues to identify the major source of circulating FGF23. Result: The uremic rats displayed dramatic changes in plasma FGF23 levels, consistent with increased expression of FGF23 in bone. Elevated FGF23 was associated with phosphate and parathyroid hormone (PTH). After PTX, the elevated FGF23 had decreased, consistent with decreased expression of FGF23 in bone. Significant decreases in plasma FGF23 were associated with PTH and 1,25(OH)2D3, but not phosphate. Conclusion: Elevated plasma FGF23 levels in uremic rats reflect the increased expression of FGF23 in bone. The expression of FGF23 in bone may be regulated by a PTH-1,25(OH)2D3 axis-dependent pathway and another PTH-dependent and 1,25(OH)2D3-independent pathway in uremic rats. The pathway may be decided by the degree of renal dysfunction.

Direct maxacalcitol (OCT) injection into a parathyroid gland (PTG) ameliorates several important etiologic factors of resistance to medical treatments for secondary hyperparathyroidism (s-HPT): the upregulations of vitamin D receptor (VDR) and Ca-sensing receptor (CaSR) in PTGs and the regression of PTG hyperplasia by the induction of apoptosis. In this study, we evaluated the bone histomorphology on the basis of maintaining these effects in advanced s-HPT. Five/six nephrectomized Sprague–Dawley rats were fed a high-phosphorus and low-calcium diet for 8 weeks. These rats were divided into four treatment groups: (1) basic uremic (at the baseline), (2) direct OCT single injection into PTGs (DI-OCT) followed by OCT intravenous administration for 4 weeks (IV-OCT), (3) direct vehicle injection and IV-OCT, and (4) no treatment for an additional 4 weeks. The effects of these treatments on serum intact-parathyroid hormone (PTH) level, PTG weight, VDR and CaSR expression levels in PTGs, and bone histomorphometric parameters were investigated. In the DI-OCT+IV-OCT group, the significant decrease in serum intact-PTH level was maintained by the following IV-OCT. A significant decrease in PTG weight and the upregulations of VDR and CaSR expression levels in PTGs were also observed. Bone histomorphometric analysis showed significant improvements in osteitis fibrosa in both cancellous and cortical bones. However, these findings were not observed in the other groups. These results suggest that osteitis fibrosa caused by advanced s-HPT can be successfully reversed by a control of PTH at an appropriate level through the improvement of PTG hyperplasia as induced by DI-OCT+IV-OCT.

The most important etiological factors of resistance to medical treatments for secondary hyperparathyroidism are the decreased contents of the vitamin D receptor (VDR) and Ca-sensing receptor (CaSR) in parathyroid cells and a severely swollen parathyroid gland (PTG) as a result of hyperplasia. The effects of direct maxacalcitol (OCT) injection into PTG in terms of these factors were investigated in this study. The PTG of Sprague-Dawley rats that were 5/6 nephrectomized and fed a high-phosphate diet were treated by a direct injection of OCT (DI-OCT) or vehicle (DI-vehicle). The changes in serum intact parathyroid hormone (PTH), Ca(2+), and phosphorus levels, in VDR and CaSR expression levels in parathyroid cells, and in Ca(2+)-PTH curves were examined. Apoptosis was analyzed by the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling method and DNA electrophoresis for PTG. DI-OCT markedly decreased serum intact PTH level, and a significant difference in this level between DI-OCT and DI-vehicle was observed. However, serum Ca(2+) and phosphorus levels did not changed markedly in both groups. The upregulations of both VDR and CaSR, the clear shift to the left downward in the Ca(2+)-PTH curve, and the induction of apoptosis after DI-OCT were observed. These findings were not observed in the DI-vehicle-treated rats. Moreover, these effects of DI-OCT were confirmed by the DI-OCT into one PTG and DI-vehicle alone into another PTG in the same rat. DI-OCT may introduce simultaneous VDR and CaSR upregulations and the regression of hyperplastic PTG, and these effects may provide a strategy for strongly suppressing PTH levels in very severe secondary hyperparathyroidism.

Objective We investigated the present state of, and trends in, hemodialysis therapy in Wakayama, with the aim of identifying present and future problems. Methods We compared the number of patients on maintenance hemodialysis, patients newly commencing hemodialysis each year, and proportion of diseases prompting the initiation of hemodialysis, between Wakayama and all Japan from 2002 to 2009, using the CD-ROM, "An overview of dialysis treatment in Japan," published by the Japanese Society for Dialysis Therapy. Results The number of patients on maintenance hemodialysis per head of population was higher in Wakayama than in all Japan throughout the study period. The number of patients newly commencing hemodialysis per head of population was higher in Wakayama than in all Japan from 2002 to 2004, but no significant difference was seen after 2005. The proportion of patients with chronic glomerulonephritis as the causative disease for hemodialysis initiation was higher in Wakayama than in all Japan. However, nephrosclerosis was less common as the causative condition in Wakayama than in all Japan. The proportions of the different causative diseases were similar in all patients on maintenance hemodialysis in Wakayama as in the newly initiated patients. Accordingly, some patients diagnosed with chronic glomerulonephritis might actually have nephrosclerosis, or treatment may be inadequate. Conclusion In order to reduce the number of patients requiring maintenance hemodailysis, it is important to accurately differentiate between chronic glomerulonephritis and nephrosclerosis, and also to treat patients with either disease appropriately.

Objective To determine whether patient exercise with the support of family members maximizes mobility and improves muscle strength in the nonparetic lower limb after stroke. Design Comparison of improvement at 2 wk between conventional exercise sessions and a program also including the participation of family members. Subjects were 60 patients rendered nonambulatory by severe hemiparesis from their first stroke. Of these, 42 had family members participating in their therapy. Lower limb strength was measured on the nonparetic side using an isokinetic machine. Mobility status was assessed using the Rivermead Mobility Index. Patients were evaluated at the first inpatient gym session and again at 1 and 2 wk. Results At the first evaluation, lower limb strength and the Rivermead Mobility Index score did not differ between the two groups. Reevaluations were conducted at 1 and 2 wk after the first evaluation. Patients' strength and mobility improved more when family members participated. Conclusion Family participation is an important contributor to stroke rehabilitation.

A 54-year-old right-handed woman suffered transient aphasia and persistent amnesia caused by a subcortical hematoma in the left occipital lobe. She appeared to have aphasia, although it disappeared within 3 weeks. It is noteworthy that she had a lesion in the left retrosplenial region but exhibited both verbal and non-verbal memory impairment. However, her intelligence, remote memory and digit span were normal. She had no topographic disturbance. Computed tomography and magnetic resonance imaging revealed a subcortical hematoma in the left occipital lobe including the retrosplenial region. Single photon emission CT showed a low perfusion area in the retrosplenial region and in the left thalamus. We concluded that the retrosplenial amnesia might be caused by the interruption of hippocampal input into the anterior thalamus.