Renal transplantation in Venezuela, 2001.
Explore the source record for details and available documents.
Cadaver↗
Biomedical subjects
E Bellorín-Font
Publications and source records attributed to E Bellorín-Font.
Role of persistent amenorrhea in bone mineral metabolism of young hemodialyzed women.
BACKGROUND: Chronic renal failure in women is frequently associated with endocrine disturbances leading to menstrual disorders. However, most studies on renal osteodystrophy have not taken into account the possible role of these hormonal disturbances on the pathogenesis of bone alterations seen in these patients. In the present study, we evaluated bone mineral metabolism in a group of young hemodialyzed women with persistent amenorrhea and compared them with similar women with regular menstruation. METHODS: We studied 74 women who were further subdivided into 43 women with regular menstrual periods and 31 women with persistent amenorrhea, defined as the absence of menstrual bleeding for more than six months. In all patients, we performed a bone mineral density (BMD) analysis and simultaneously evaluated different biochemical parameters, intact parathyroid hormone (iPTH), sexual hormone determinations that included total estradiol, follicle-stimulating (FSH), and luteinizing hormone and markers of bone resorption such as the procollagen type 1 cross-linked carboxy-terminal telopeptide (ICTP). RESULTS: Serum calcium, phosphorus, and iPTH were similar in both groups. Serum alkaline phosphatase was higher in amenorrheic women. Although the total serum estradiol concentration was normal in the amenorrheic women when compared with nonuremic women, the values were significantly lower than those in regularly menstruating women. Serum FSH and ICTP values were significantly higher in the amenorrheic women. Trabecular BMD in the lumbar spine was also significantly lower in the amenorrheic women compared with regularly menstruating dialysis patients. Lumbar spine BMD and total estradiol levels correlated significantly in the amenorrheic group. CONCLUSIONS: These studies show that persistent amenorrheic young women on dialysis have lower trabecular BMD and evidence of increased bone resorption when compared with normal menstruating women on dialysis. The possible impact of these results in the natural history of the uremic osteodystrophy remains to be determined.
Adult↗
Latin American nephrology: scientific production and impact of the publications.
BACKGROUND: During the last two decades, there has been a significant change in the origin and impact of the world's biomedical scientific production, particularly in countries in which the investment in research accounts for an important portion of the gross national product (GNP). However, in less developed countries, budget restrictions and the lack of policies toward research may determine a limited growth of the scientific production. METHODS: We examined the number and impact of peer-reviewed publications from Latin America included in the Institute of Scientific Information (ISI) and MEDLINE databases. In addition, we analyzed the number of abstracts submitted to the congresses of the International Society of Nephrology (ISN), American Society of Nephrology (ASN), and Latin American Society of Nephrology and Hypertension (SLANH). RESULTS: The number of peer-reviewed publications in nephrology from authors in Latin America during the last 20 years represented less than 1% of the world's total. Only 13 out of the 22 Latin American countries accounted for these publications. The citation impact (3.52) was below the world average (7.82). However, this index showed a tendency towards growth in the five most productive countries. Likewise, the number of abstracts submitted to international meetings of nephrology by authors in Latin American countries has shown a steady growth in the recent years, but remains proportionately low compared with the rest of the world. CONCLUSIONS: This study indicates that although efforts toward improving the quantity and quality of research in Latin America have been made, the final results are less than other regions in the world. Possible factors responsible for the low performance include a failure in academic motivation and lack of pressure for publication, as well as limited research funding. Therefore, important efforts from local and international nephrological communities are needed to boost research in Latin America.
Developing Countries↗
Magnesium and phosphorus.
A summary of new findings regarding alterations of magnesium (Mg2+) and phosphorus (P) metabolism are reviewed for the clinician caring for patients in general wards. Alterations in serum concentrations of Mg2+ and P are frequently observed in acute or very ill patients in emergency rooms or intensive-care areas. A significant proportion of these alterations are iatrogenic. Most of the symptoms related are non-specific, and usually they are associated with changes in concentration of other ions. The need to measure Mg2+ and P routinely and to define better the real abnormal values is stressed. Correction of the abnormalities must be early in the course of the alterations.
Acute Disease↗
Bone disease in hypercalciuria: a new form of osteodystrophy?
Explore the source record for details and available documents.
Bone Density↗
[Role of bones in the physiopathology of idiopathic hypercalciuria: effect of amino-bisphosphonate alendronate].
Previous studies from our laboratory demonstrated that bone mineral content is affected in patients with idiopathic hypercalciuria and that there is a correlation between bone mineral loss and in-vitro cytokine production. At the same time we found that short term treatment with alendronate decreased urinary calcium in these subjects. In the present study we have examined the long-term effects of alendronate treatment (10 mg/day for one year) on urinary calcium, urinary hydroxyproline and bone mineral content in 18 idiopathic hypercalciuric and 8 normocalciuric stone formers. Clinical characteristics, as well as gender and age distribution were similar in both groups. Urinary calcium and hydroxyproline, were measured monthly. Calcium excretion decreased significantly at the end of the first month, and remained lower thereafter (277 +/- 28, before vs. 202 +/- 26 mg/g creatinine, after 12 months on alendronate, p < 0.01). Urinary hydroxyproline decreased significantly during the study (125.5 +/- 32.1 vs. 39.66 +/- 17.5 mg/g creatinine, p < 0.05). Serum calcium, glomerular filtration rate, and urinary sodium, did not change during the study. Lumbar spine bone density (trabecular bone) obtained with X ray absorptiometry revealed a significant increase from 1.162 +/- 0.231 to 1.197 +/- 0.248 g/cm2 (p < 0.01). These changes were associated with a significant decrease in IL-1 alpha mRNA transcription by unstimulated and lipopolysaccharide stimulated blood mononuclear cells, as tested by the reverse transcriptase polymerase chain reaction. No changes were observed in bone cortical sites (femoral neck). Normocalciuric subjects showed no significant changes in urinary calcium. In summary, the changes observed in urinary calcium excretion and different bone metabolic parameters, suggest a role of bone in the pathophysiology of idiopathic hypercalciuria.
Alendronate↗
Possible role of cytokines on the bone mineral loss in idiopathic hypercalciuria.
Decreased bone mass has been reported in patients with idiopathic hypercalciuria. Previous studies, using bioassays, have suggested a role of interleukin-1 (IL-1), in the decreased bone mineral density (BMD) of fasting hypercalciuria. The present study was designed to determine which IL-1 fraction (alpha or beta) correlates with bone resorption and whether other known bone resorting cytokines like interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) may play a role in this process. Cytokines production was determined by quantitative and specific analysis, enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase polymerase chain reaction (RT-PCR). Dual-energy X-ray absorptiometry and cytokine production by unstimulated and lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs) were determined in a group of 29 patients with recurrent nephrolithiasis (17 hypercalciurics and 12 normocalciurics), and 12 healthy controls. The hypercalciuric subjects showed lower vertebral BMD than the normocalciuric or normal controls. There was no difference in spinal or femoral BMD between absorptive or fasting hypercalciurics. A significant negative correlation existed between urinary calcium excretion and vertebral BMD (r = -0.55, P < 0.01). Basal IL-1 alpha production correlated with vertebral BMD (r = -0.45, P < 0.02). This correlation was not seen with IL-1 beta, IL-6 or TNF-alpha production. LPS-induced IL-6 and TNF-alpha production were enhanced in the hypercalciuric patients, when compared to normocalciurics or controls. Control and normocalciuric subjects showed minimal amounts of IL-1 alpha mRNA. In contrast, hypercalciuric patients showed a significant increase of spontaneous IL-1 alpha mRNA transcription. These results suggest that different cytokines could be involved in the bone resorption process observed in hypercalciuria.
Absorptiometry, Photon↗
[Need and demand of kidneys for transplantation in Venezuela].
The number of cadaveric kidneys available for transplantation has become insufficient around the world. Despite concerted efforts, we have been unsuccessful in greatly improve the supply of organ donors, and consequently the number of end stage renal failure patients awaiting for kidney transplantation continues to increase. The primary objective of this paper is to quantify the need and supply of kidneys for transplant in Venezuela. An overview of the current level of kidney transplant activity in Venezuela is presented, observing that the activity with cadaveric donors had been predominant since 1983, although not to an optimal level. The annual activity in kidney transplant between 1989-1991 remained stable in 6 transplants/million people, but went sharply down to 4.6 in 1992. An estimate of the current need is around 10 donors/million people. This is in contrast with an effective donation rate of only 2.01 and 1.92 donors/million achieved in 1990 and 1991 respectively. The most frequent cause for no donation was the lack of familiar consent. Based on an analysis of the factors involved in the shortage of donor supply in Venezuela, we present some recommendations to increase the availability of cadaveric organ donors in the country. These measures include an improvement of education and legal regulation in the field of organ donation and transplantation, and following the Spanish model, the creation of a program of hospital transplant coordinators that can detect and evaluate potential organ donors as well as coordinate the logistical aspects of transplantation.
Humans↗