The effect on the bones of condensed phosphate when used as food additives: Its Importance in Relation to Preventive Medicine

Based on the fact that chemical products such as binding agents are produced by mixing three kinds of phosphates with different ratios, we mixed metaphosphate, polyphosphate and pyrophosphate. Each was made to Na-phosphate, K-phosphate, and Ca-phosphate and each was mixed with commercial feeds so that the content of P would be approximately 0.1, 0.15, 0.3, 0.4, 0.6 and 1.0%. The prepared pellets were given to ICR, CF # 1 and AKR strains of mice at 29 days of age for 680 days and observations were made through this experimental period at different stages. The observations were also carried out on the mice administered with the experimental feeds for 1.5 months from 9 to 10.5 months of age. The observations were compared with those of the control group at all times. As a result, plasma 1 α, 25 (OH)₂ D₃ and P levels were always significantly higher in the phosphate administered groups relative to the control. Urine P and Fe increased while urine Ca decreased in the phosphate-treated groups. The effect of phosphates on the bones was studied taking soft X-ray pictures of hind legs and applying microdensitometry to them. Through these observations we recognized thinning of the cortex of bones, reduction of marrow trabecules and development of osteophyte. Histological observations disclosed that changes in knee joint tissues were apparent; that is, a decrease in or an irregular loss of the number of cells in superficial, intermediate, and radial strata of the joint cartilage, proliferation of subchondral bone, and the development of osteophytes were noted. As for muscles, diameters of musclar fibers became smaller; in particular, type II fibers showed greater shrinkage. Regarding kidneys, swelling and atrophy of glomerular capillaries, proliferation of mesangial cells, nephroselerosis, swelling, thinning, and loss of tubular epithelium, interstitial tissue inflammation, development of cylindruria, and deposition of calcium were observed. All these changes seem to be a particularly advanced aspect of the changes which are more pronounced with increasing dose and age. These changes were found even in the group administered with the feed containing 0.1% phosphorus, and, these changes were dependent on the concentration level of P. It was observed that administration to older subjects for a short term (1.5 months) produced effects stronger than those to younger subjects administered for a long term (10.5 months). The effects of condensed Ca-phosphate on bones were similar to those of condensed Na- and K-phosphates, and, hence, it was supposed that these effects were caused by phosphate radicals. An erratum to this article is available at .     

The modulatory effect of endogenous parathyroid hormone on the action of hydrochlorothiazide in pseudohypoparathyroidism type I

We compared the effect of orally administered 100 mg of hydrochlorothiazide (HCTZ) among eight patients with pseudohypoparathyroidism (PHP) type I, 11 patients with idiopathic hypoparathyroidism (IHP), and 12 patients with primary hyperparathyroidism (1^oHPT). Patients with PHP type I or with IHP were studied during the treatment with 1-hydroxylated metabolites of vitamin D₃. HCTZ raised serum levels of calcium (Ca) in 1^oHPT (P<0.001) and PHP type I (P<0.01) but did not increase urinary excretion of Ca. Serum parathyroid hormone (PTH) in PHP type I decreased (P<0.02) after HCTZ administration in response to the increase in serum Ca. HCTZ did not raise serum levels of Ca in IHP but increased urinary excretion of Ca in this group (P<0.01). HCTZ suppressed tubular reabsorption of phosphate (P) in IHP (P<0.01) and 1^oHPT (P<0.05) but not in PHP type I. Urinary excretion of cAMP did not change after HCTZ administration in PHP type I, IHP, or 1^oHPT. Endogenous PTH modulated the effects of HCTZ on Ca mobilization from bone and renal reabsorption of Ca in PHP type I with normal or high serum levels of PTH and in 1^oHPT with high serum levels of PTH. The inhibitory effect of HCTZ on renal tubular reabsorption of P (probably from proximal tubules) was independent of PTH. The resistance to this inhibitory effect of HCTZ on P reabsorption in PHP type I suggested a proximal tubular dysfunction in this disorder.     

Hypertension two years after renal transplantation: causes and consequences

The incidence of hypertension 2 years after renal transplantation and the possible causes of hypertension were studied retrospectively. A group of 93 patients treated with cyclosporin (CyA), azathioprine (Aza), and/or prednisolone (Pred) were compared to a group of 31 patients treated with Aza and Pred. There were more patients with hypertension in the CyA group (73%) than in the Aza group (58%). Hypertension before transplantation predisposed to hypertension after transplantation. After transplantation, hypertension was most common among patients with polycystic kidney disease (46%), chronic glomerulonephritis (67%), and diabetes (71%). The accumulated immunosuppressive medication (CyA/Pred) did not affect the occurrence of hypertension. Hypertensive patients had significantly poorer graft function than did normotensive patients (serum creatinine level 229 mol/l vs 162 mol/l, P<0.01). The 10-year graft survival was markedly impaired in the group with hypertension (42% vs 65% for normotensives, P<0.05). The 10-year patient survival was 59% vs 79% (P=NS). The study further confirms the frequent finding that hypertension has a negative effect on graft and patient survival rates.     

The endothelium-derived relaxing factormediated acetylcholine response of the arterial perfusion pressure after cold storage of the isolated rabbit kidney

The vasodilatation induced by acetylcholine (ACh) in a rabbit isolated perfused kidney was abolished when the tissue was exposed to cold ischemia for 72 h in Euro-Collins (EC) solution. This vasodilatation is due to the release of endothelium-derived relaxing factor (EDRF) from renal vasculature as evidenced by the attenuation following methylene blue pretreatment. When kidneys were preserved in EC solution containing UK 38 485, a thromboxane synthase inhibitor, or nicardipine, a calcium channel blocker, ACh-induced vasodilatation persisted after 72 h of cold ischemia. These results were taken as evidence of tissue protective activity of UK 38 485 and nicardipine and have promising implications for cadaveric kidney transplantation.This paper was presented at the 35th World Congress of the International Society of Surgery in Hong Kong in August 1993     

A case of totally cystic fibroepithelial polyp of the renal pelvis

Fibroepithelial polyps are the most frequently observed mesenchymal tumors of the renal pelvis. We report on one case of fibroepithelial polyp of the renal pelvis with unusual CT findings of totally cystic structure with septations. Received: 27 July 1998; Revised: 6 January 1999; Accepted: 8 February 1999     

Urine colour as an index of hydration in critically ill patients

In order to test the hypothesis that urine colour can be used as an index of hydration in critically ill patients, we selected 40 intensive care and high-dependency patients and correlated urine colour (scored on an eight-point scale) with various indices of hydration: urine:plasma sodium, osmolality and urea ratios, urine output and central venous pressure. In addition, we compared the colour-chart score with scores made by intensive care nurses (without the benefit of a colour chart) in order to test subjective assessment of urine colour. There were weak but statistically significant correlations between urine colour and urine output (Spearman's r = - 0.555) and between urine colour and urine:plasma sodium ratio (Spearman's r = - 0.459). Subjective assessment of urine colour appeared to be reliable. Thus, although urine colour does vary with hydration in the critically ill, assessment of urine colour adds little to the overall assessment of hydration in this group of patients.     

髓质海绵肾X线诊断12例

目的：提高对髓质海绵肾Ｘ线表现的认识。方法：报告１２例髓质海绵肾的Ｘ线平片和ＩＶＰ所见,并作文献复习。结果：本病的Ｘ线平片和ＩＶＰ均有特征性改变。结论：Ｘ线平片和ＩＶＰ是诊断髓质海绵肾的首选方法。     

Endothelin-induced inositol phosphate formation in rat kidney. Studies on receptor subtypes, G-proteins and regulation during ontogenesis

The aim of this study was to characterize the properties of endothelin (ET)-receptor subtypes mediating inositol phosphate (IP)-formation in rat kidney and their regulation during ontogenesis. In renal cortical slices of adult rats (12–16 weeks old) ET's concentration-dependently increased IP-formation with an order of potency ET -1 ET 3. While the non-selective ET receptor antagonist bosentan (10 M) completely suppressed ET-induced IP-formation, the ETA-receptor antagonist BQ-123 (10 M) inhibited it only by 70%, the ET_B-receptor antagonist IRL 1038 (1 M) by 25%; combined application of BQ-123 + IRL 1038 caused complete inhibition of ET-1-induced IP-formation. Pretreatment of isolated renal cells with pertussis toxin (PTX, 500 ng/ml) overnight did not attenuate but significantly increased ET-1-induced IP-formation. Ontogenetic studies in renal slices from neonatal, 1, 2, 3, 6, 12 and 24 weeks old rats revealed that ET-1-induced IP-formation maturation-dependently declined being highest in neonatal rats (increase: 169% over basal) and lowest in 24 weeks old rats (increase: 47% over basal). This decline in ET-induced IP-formation was accompanied by a decrease in renal ET receptor number and the amount of immunodetectable G_q/11 (assessed by Western-blotting using the QL-antiserum). Moreover, ET receptor subtypes changed during the maturation process: from neonates to 12 weeks old rats number and functional responsiveness of ET_A-receptors declined, while that of ET_B-receptors increased. We conclude that in adult rat renal cortex ET-induced IP-formation is mediated by activation of both ET_A- and ET_B-receptors and does not involve a PTX-sensitive G-protein. ET-induced IP-formation declines during the maturation process; this is associated with a decrease in ET-receptor number and the immunodetectable amount of G_q/11.