[Multiple enterolithiasis, coexisting with bladder and gallbladder lithiasis, associated with colon adenocarcinoma]. / Enterolitiasis múltiple, coexistiendo con litiasis biliar y vesical, asociada a adenocarcinoma de colon.

Enteroliths are calculi primarily formed in the intestine. Enterolithiasis is a rare condition frequently associated with intestinal stasis. Usually it causes no symptoms in most cases, but it can be an important diagnostic clue in patients presenting intestinal occlusive symptoms. We report a case of multiple enterolithiasis, very infrequent pathology, coexisting with bladder and gall bladder lithiasis in a patient with colon adenocarcinoma. Diagnosis was made by X-rays and CT images. Calculi were analysed by several methods: chemical, infrared spectroscopy, stereoscopic microscopy and atomic emission spectroscopy; they showed that caluli are made up of organic material and whilokita (calcium and magnesium ortophosphate). No risk factors for lithogenesis were found in this patient excluding the intestinal stasis caused by intestinal narrowing as a result of adenocarcinoma. Genetic factors are suggested as main contributors to hyperlithogenesis observed in this patient. The physiopathological conditions were studied in depth and literature about this subject reviewed.

Correlation between serum osteocalcin and 24,25-dihydroxyvitamin D levels in Paget's disease of bone.

We have studied the possible correlation between serum 24,25-dihydroxyvitamin D [24,25-(OH)2D] and osteocalcin levels (sBGP) in Paget's disease of bone. We measured serum calcium, phosphate, PTH, 25-hydroxyvitamin D, 1,25-(OH)2D, 24,25-(OH)2D, alkaline phosphatase (sAP), and the urinary hydroxyproline/creatinine ratio (UOH prol/creat) in 19 patients with Paget's disease of bone and 16 age- and sex-matched controls. As expected, sAP, UOH prol/creat, and sBGP levels were significantly elevated, and there was a tendency to a decrease in serum levels of 24,25-(OH)2D in Pagetic patients with respect to the control group. There was no significant difference between patients and controls in serum calcium, phosphate, PTH, 25-hydroxyvitamin D, and 1,25-(OH)2D. The Pagetic patients were subdivided into two subgroups; subgroup A had normal sBGP levels (less than 5 ng/mL), and subgroup B had increased sBGP levels (greater than 5 ng/mL). Serum 24,25-(OH)2D levels in subgroup B were significantly lower than those in controls, while subgroup A showed levels similar to those in the control group. We also found a positive linear correlation between sAP and sBGP and between sAP and UOH prol/creat as well as a negative linear correlation between sBGP and 24,25-(OH)2D and between 24,25-(OH)2D and UOH prol/creat in Pagetic patients. These results point to a possible role of 24,25-(OH)2D in disease activity.

Evidence of 1,25-dihydroxyvitamin D synthesis by the rat Walker carcinosarcoma 256.

We tested the existence of 25-hydroxyvitamin D-1 alpha-hydroxylase activity in the Walker carcinosarcoma 256 implanted in rats. This tumour has been shown to induce hypercalcaemia in the host animal. We found this enzyme activity in tumour homogenates, which was in the same range as that in the kidney of tumour-bearing rats. Our results suggest that 1,25-dihydroxyvitamin D synthesized by the Walker tumour might be involved in the mechanism responsible for the hypercalcaemia in the host rat.

New biochemical markers of bone resorption in the study of postmenopausal osteoporosis.

We performed a comparative study on the sensitivity of the determination of several biochemical markers of bone resorption: urinary calcium/creatinine, free pyridinolines (F-Pyr), free deoxypyridinoline (F-Dpyr), carboxyterminal telopeptide of collagen I (CTX) and aminoterminal crosslinked telopeptides of collagen I (NTX) in the study of postmenopausal osteoporosis. The study included 19 untreated osteoporotic postmenopausal women, aged 59 +/- 6 years, range 46-70 and 16 healthy control postmenopausal women, aged 56 +/- 7 years, range 48-70 years. The following bone markers were determined in 2-h fasting urine samples: calcium/creatinine (atomic absorptiometry), F-Pyr (ELISA, Metra), F-Dpyr (ELISA, Metra), CTX (Crosslaps, Cis bio International) and NTX (ELISA, Osteomark, OSTEX). Values of all markers were expressed as urinary creatinine (Cr) ratios. We found a significant increase in all the studied biochemical markers of bone resorption in osteoporotic patients with respect to control women. Areas under receiver operating characteristic (ROC) curves corresponding to F-Pyr/Cr, Calcium/ Cr, NTX/Cr, CTX/Cr and F-Dpyr/Cr were 74%, 75%, 93.4%, 95.7% and 96% respectively. There were no significant differences among the areas of the ROC curves corresponding to NTX, CTX and F-Dpyr, but areas under urinary calcium and F-Pyr were significantly lower. Among the biochemical markers of bone resorption studied, F-Dpyr, CTX and NTX presented the best discrimination between osteoporotic and control women. F-Dpyr/Cr sensitivity was 79% with a specificity of 100%, CTX/Cr sensitivity was also 79% with a specificity of 100% and NTX/Cr sensitivity was 52% with a specificity of 100%.

Biochemical markers of bone remodeling and bone sialoprotein in ankylosing spondylitis.

The aim of this work was to determine bone mineral density (BMD) in a group of patients with ankylosing spondylitis (AS) and to study alterations in bone remodeling in these patients. Eighteen patients (16 males and two females) with AS, mean age 44.7, range 21-75, and 18 age- and sex-matched healthy controls were studied. BMD was evaluated by dual energy X-ray absorptiometry. The following biochemical markers of bone remodeling were studied: formation - serum amino and carboxyterminal propeptides of procollagen I (PINP and PICP); resorption - urinary total and free deoxypyridinoline and pyridinoline (TDpyr, FDpyr, TPyr and FPyr), crosslinked aminoterminal telopeptides of collagen I (NTX), carboxyterminal telopeptide of collagen I (CTX) and serum bone sialoprotein (BSP). Receiver operating characteristic (ROC) curves of markers were also performed. We found a decrease of bone mass and an increase in TPyr, FPyr, TDpyr, FDpyr, NTX and BSP in AS, but no significant differences were found in PICP, PINP and CTX. FDpyr, FPyr and TPyr showed the highest discrimination between patients and controls according to the results of the ROC curves. TPyr/TDpyr was higher in AS than in controls. We found osteopenia, with a normal formation and a significant increase in bone resorption in AS. FDpyr, FPyr and TPyr seem to present the best sensitivity for the study of alterations of bone resorption in this pathology, although NTX, TDpyr and BSP also show significant differences. The elevation in the ratio TPyr/TDpyr in AS compared to controls indicates that in AS there is a type I-collagen degradation in tissues different from bone.

A variation in Bone Alkaline Phosphatase levels that correlates positively with bone loss and normal levels of aminoterminal propeptide of collagen I in girls with anorexia nervosa.

Anorexia nervosa (AN) is a very extended pathology among adolescent girls nowadays. These patients show a high degree of osteopenia; hence, study of their bone remodelling is of great interest. Serum bone alkaline phosphatase (bAP) and aminoterminal propeptide of procollagen I (PINP) provide good sensitivity in the analysis of bone alterations in postmenopausal osteoporosis. The aim of this study was to compare the usefulness of bAP and PINP in the study of bone remodelling in AN, and their possible correlation with the degree of osteopenia in this pathology. In order to help in the interpretation of the results, levels of the beta-isomer of urinary carboxyterminal propeptide of collagen I (beta-CTX) have also been included. Serum bAP (IRMA) Tandem R-Ostase, Hybritech), PINP (RIA, Orion Diagnostica) and CTX (CrossLaps ELISA, Osteometer) were determined in 41 girls with AN, aged 18.5+/-2.2 years (mean+/-SD) and in 31 healthy control women, aged 19+/-2.3 years. Bone mineral density (BMD) in lumbar spine was measured by DEXA in the AN group. We found that 41 of the 43 patients had BMD z-scores under -2. No significant differences were found in the levels of serum bAP nor in PINP and beta-CTX levels between controls and patients, although values in the AN group were highly variable. All the BMD z-score values were negative, and their absolute value correlates positively with bAP (P = 0.0279) and almost with beta-CTX (P = 0.0921) but not with PINP (P = 0.4627). Bone AP correlates with PINP in control girls (P = 0.017), but not in the AN group (P = 0.3573). Patients with AN were divided into three groups according to their levels of bAP: low (I), normal (II) or high (III). Patients with the highest bAP levels also presented the highest increase in bone resorption, according to their beta-CTX levels, and the highest degree of osteopenia. However, values of PINP were similar in the three groups of patients. The bAP/beta-CTX ratios in subgroups I, II and III of AN patients were 0.035, 0.065 and 0.073, a finding that suggests that bAP is not indicating the real degree of bone mineralization in these patients, because it is a contradiction that the formation/resorption ratio should be higher in the patients who have the highest bone loss. These results could suggest that bone loss in AN is produced by an increase in bone resorption (beta-CTX), without variations in bone matrix formation (PINP); bAP levels are a good marker in the follow-up of osteopenia degree, but not a real indicator of bone mineralization, a similar situation to that of osteomalacia.

Mitochondrial alkaline phosphatase as an intracellular signal in the synthesis of 1,25(OH)2D3 and 24,25(OH)2D3 in LLC-PK1 cells.

In previous works we have found a mitochondrial alkaline phosphatase (AP) activity in LLC-PK1. The aim of this work has been to study the possible involvement of mitochondrial AP activity in the synthesis of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) from the substrate 25(OH)D3. Renal phenotype LLC-PK1 cells were incubated with 25(OH)D3 as substrate and treated with or without 1,25(OH)2D3, forskolin, 12-myristate-13-acetate (PMA) and 1,25(OH)2D3 in conjunction with PMA. Incubation of LLC-PK1 cells with forskolin (adenylate cyclase activator) not only stimulated the 1-hydroxylase and inhibited the 24-hydroxylase activities but also increased the mitochondrial AP activity. The addition of 1,25(OH)2D3, the main activator of 24-hydroxylase, produced a decrease of mitochondrial AP activity, a decrease of 1,25(OH)2D3 synthesis and an increase of the 24,25(OH)2D3 synthesis. Incubation with PMA, a potent activator of protein kinase C, did not produce any changes in mitochondrial AP activity, but an inhibition of 1,25(OH)2D3 and an activation of 24,25(OH)2D3 synthesis were found. Moreover, incubation of LLC-PK1 cells with PMA in conjunction with 1,25(OH)2D3 produced an additive effect in the decrease of 1,25(OH)2D3 and an increase of 24,25(OH)2D3 synthesis remaining mitochondrial AP activity as cells treated only with 1,25(OH)2D3. Our results suggest that mitochondrial AP activity could be involved as an intracellular signal in the regulation of 25(OH)D3 metabolism to the synthesis of 1,25(OH)2D3 and 24,25(OH)2D3 in renal phenotype LLC-PK1 cells through cAMP protein kinase system.

Bone specific binding sites for 1,25(OH)2D3 in magnesium deficiency.

It has been reported that some hypoparathyroid patients with magnesium deficiency showed altered responses to vitamin D treatment. In the same way, in vitro bone studies have demonstrated the existence of a decrease in the 1,25-dihydroxyvitamin D3-induced resorption in bone as a result of magnesium deficiency. These findings suggest some kind of alteration in the 1,25(OH)2D3 in bone in magnesium deficiency. In the present work, using a binding assay based on the 1,25(OH)2D3 and 3H-1,25(OH)2D3 competition for the hormone binding sites in rat calvaria homogenates, a significant decrease in the number of 1,25(OH)2D3 specific binding sites has been found in calvaria incubated in magnesium-deficient medium compared to magnesium-replete ones. Alterations in the hormone-receptor affinity were not found. These results suggest that an alteration in the 1,25(OH)2D3 action on magnesium-deficient bone could be due, at least in part, to a decrease in the number of available vitamin D receptors in bone cells.

Effects of 24,25(OH)2D3, 1,25(OH)2D3 and 25(OH)D3 on alkaline and tartrate-resistant acid phosphatase activities in fetal rat calvaria.

The aim of this work was to evaluate the effects of 24,25-dihydroxyvitamin D3, 24,25(OH)2D3, on alkaline phosphatase (AP) and tartrate-resistant acid phosphatase (TRAP) activities in fetal rat calvaria cultures. These actions were compared with those of 1,25-dihydroxyvitamin D3, 1,25(OH)2D3, and 25-hydroxyvitamin D3, 25(OH)D3, in similar experimental conditions. At 10 min, 30 min and at 24 h incubation time, 1,25(OH)2D3 (10(-10)M) and 25(OH)D3 (10(-7) M) produced a significant increase in AP and TRAP activities compared to control group (without vitamin D metabolites). However, 24,25(OH)2D3 (10(-7) M) only produced effects on phosphatase activities similar to those produced by 1,25(OH)2D3 and 25(OH)D3, after 24 h incubation time. These findings suggest that 1,25(OH)2D3 and 25(OH)2D3 could carry out actions in minutes (nongenomic mechanism), while 24,25(OH)2D3 needs longer periods of time to perform its biological actions (genomic mechanism).

[Hypercalciuric and hyperparathyroid renal lithiasis]. / Litiasi renale ipercalciurica e iperparatiroidea

Idiopathic hypercalciuria was noted in 10% of a series of 1635 subjects with renal lithiasis. Eight-day administration of thiazide diuretics as a test for the discovery of latent hyperparathyroidism in idiopathic hypercalciuria is described. In 6 cases diagnosed in this way, surgery disclosed the presence of a parathyroid adenoma. Resection was followed by persistent hypercalciuria and, in some instances, renal lithiasis activity. The pathogenesis of associations of these frequently observed diseases is examined.

[Nephrocalcinosis as a clinical syndrome. Study of 77 cases (author's transl)]. / La nefrocalcinosis como síndrome clínico (análisis de 77 casos).

Seventy-seven patients with nephrocalcinosis as revealed by X-ray studies over a 10-year period are reviewed. A programmed clinical and metabolic study was performed on each case; the author's criteria included the different pathogenic factors considered in the etiologic definition of the disease. There were 22 cases with primary hyperparathyroidism, 19 with spongy kidney, nine with tubulointerstitial nephropathy, five with hyperoxaluria, five with distal renal tubular acidosis, four with esential hypomagnesemia, and three cases of miscellaneous etiology (vitamin D intoxication, Fanconi's syndrome, Bartter's disease). Ten other cases were classified as idiopathic nephrocalcinosis since no definite cause could be found. The clinical characteristics (symptoms, associated diseases, diet and medication intake, family history) and the biochemical findings are analysed for each group. The physiopathologic mechanisms, comparisons between each etiologic group, treatment, clinical course, and prognosis are commented on. The conclusion drawn is that nephrocalcinosis is a clinical syndrome of various etiologies which in most cases arises from an underlying metabolic disease.

Influence of magnesium on the in vitro synthesis of 24,25-dihydroxyvitamin D3 and 1 alpha, 25-dihydroxyvitamin D3.

The role of magnesium in the regulation of 25(OH)D3-24R-hydroxylase and 25(OH)D3-1 alpha-hydroxylase in vitro remains to be clarified. Using a radiochemical assay, the effect of substrate concentration on both enzymes was measured in rat kidney homogenates as well as the alterations in their kinetic behaviour resulting from changes in the magnesium concentration in the incubation medium. The results showed that magnesium could be a modulator of 24- and 1 alpha-hydroxylases. Variations in magnesium caused alterations in the kinetic behaviour of both enzymes, which altered the synthesis rates of 24,25(OH)2D3 and 1,25(OH)2D3. Moreover, the substrate concentration was clearly involved in the response of both enzymes to the modulation by magnesium.

Possible involvement of a magnesium dependent mitochondrial alkaline phosphatase in the regulation of the 25-hydroxyvitamin D3-1 alpha-and 25-hydroxyvitamin D3-24R-hydroxylases in LLC-PK1 cells.

It has been demonstrated that dephosphorylation of the ferredoxin component of the mitochondrial 25-hydroxyvitamin D3-1-hydroxylase, as a result of a PTH-cAMP mediated activation, involves a protein phosphatase activity. However, the nature and properties of this phosphatase are uncertain. It has been proved that alkaline phosphatase, a magnesium dependent enzyme, could dephosphorylate in vitro the ferredoxin component of the 25-hydroxyvitamin D3-1-hydroxylase. Moreover, some evidence of mitochondrial localization of some alkaline phosphatases has been published. Although the existence of a levamisole inhibitable alkaline phosphatase activity has been described in renal cells, its role remains to be elucidated. In the present work, the existence of an alkaline phosphatase in mitochondrial membrane preparations from LLC-PK1 cells has been described. This alkaline phosphatase is magnesium dependent and levamisole inhibitable. Preparations of mitochondrial membrane from LLC-PK1 cells also showed 25-hydroxyvitamin D3-1-hydroxylase (1-hydroxylase) and 25-hydroxyvitamin D3-24R-hydroxylase (24-hydroxylase) activities being both enzymes responsive to the 8Br-cAMP mediated regulation. The 8Br-cAMP not only stimulated the 1-hydroxylase and inhibited the 24-hydroxylase activities but also increased the mitochondrial alkaline phosphatase activity. In the same way, the levamisole (specific inhibitor of some alkaline phosphatases) inhibited the mitochondrial alkaline phosphatase and also the 1-hydroxylase activity. In addition, the inhibition of mitochondrial alkaline phosphatase by levamisole avoids the effect of 8Br-cAMP on the 1-hydroxylase and 24-hydroxylase activities. On the other hand, the mitochondrial alkaline phosphatase and the 1-hydroxylase activities showed similar behaviour with respect to the magnesium concentrations in the incubation medium. Taking these results together it could be possible to suggest the implication of the Mg(2+)-dependent mitochondrial alkaline phosphatase activity found in LLC-PK1 cells in the regulation of the 1,25(OH)2D3 and 24,25(OH)2D3 synthesis.

Possible alterations of the in vivo 1,25(OH)2D3 synthesis and its tissue distribution in magnesium-deficient rats.

In a previous work we showed that a decrease in the free intracellular magnesium produced alterations in the kinetic behaviour of 1 alpha-hydroxylase which reduced the synthesis rate of 1,25(OH)2D3. This in vitro result strongly supports that magnesium deficiency could also induce in vivo failure of the renal enzyme and then a decrease of 1,25(OH)2D3 serum levels. In the present work we have tested the effect of magnesium deficiency on the in vivo transformation of the substrate 3H-25(OH)D3 to 3H-1,25(OH)2D3 as well as the distribution of synthesized hormone among its different target tissues. We found that magnesium deficiency produced a decrease of both the in vivo synthesis of 3H-1,25(OH)2D3 and the binding of the radioactive hormone to bone tissue. These results may explain the different criteria present in the scientific literature concerning the relationships between magnesium status and vitamin D metabolism.

[Alkaptonuria, prostatic calculi, and ectopic ureter]. / Alcaptonuria, litiasis prostática y uréter ectópico.

Alkaptonuria is an uncommon tyrosine metabolism disorder. Deficit of homogentisic acid oxidase leads to the elimination of large amounts of homogentisic acid in the urine with accumulation of homogentisic acid oxidized pigment in the connective tissue (ochronosis). The ultimate evolution of ochronosis is degenerative arthritis. The clinical case reported is a 57-year old male diagnosed with alkaptonuria in an early stage of the connective tissue disease who comes to the clinic due to a lower urinary obstructive syndrome secondary to benign prostate hyperplasia but is diagnosed with giant prostate lithiasis. The patient undergoes retropubic adenomectomy with lithiasis removal and re-implantation of ectopic ureter from a dual left excretory system. Clinical evolution is completely successful. The rarity of the case calls for circulation and revision of the clinical and therapeutical aspects of this entity.