[Clinical research based nephrology (bases for the constitution of an Evidence Based Nephrology Group in the Spanish Society of Nephrology)].
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Biomedical Research↗
Biomedical subjects
A Tato
Publications and source records attributed to A Tato.
[Prospective monitoring of vascular access in hemodialysis by means of a multidisciplinary team].
PURPOSE: Nowadays, expert guidelines recommend the monitoring programs of the vascular access (VA) by a multidisciplinary team. MATERIAL AND METHOD: We present the experience over the last five years, of a prospective VA surveillance by a multidisciplinary team. The quality indicators reached are described as the associated factors for survival of the new VA. RESULTS: Three hundred seventeen VA have been studied, 73% were arteriovenous fistulas(AVF) and the rest were polytetrafluoroethylene (PTFE) grafts at 282 patients. The main causes of dysfunctions were elevated dynamic venous pressure (42.5%) and the decreased blood flow (36.4%) with a 88% of positive predictive value. Over the 5 years there was 88 thrombosis (24 AVF and 64 PTFE grafts), that means a hazard thrombosis global rate of 0.15 access/year, which were distributed in 0.06 for AVF and 0.38 in PTFE grafts. Two hundred and one repairs of VA were done: 66.6% were elective repair after a proper review by the multidisciplinary team and the rest of them were done after the AV thrombosis happened. Urgent rescue surgeries were done in 76% of the thrombosis. 62.5% of the patients did not need a catheter after vascular access thrombosis. The complication relation with AVF and PTFE were 11.4% of the total patients hemodialysis hospitalizations. 65.2% of the VA were new access. 57% of patients were properly reviewed in the pre-dialysis unit at least once and 80% of them start haemodialysis with a mature access. The average survival (Kaplan Meier) of the new AVF was 1,575+/-55 days vs 1,087+/-102 of the PTFE grafts (p < 0.008). The survival after 1, 2 and 3 years for the AVF was 89%, 85% and 83% and for the PTFE graft 3% 67% and 51% respectively. The Cox regression has proved that the type of vascular access is the strongest factor associated to VA survival. The survival added of VA repaired due to dysfunction was 1,062 +/- 97 days vs 707 +/- 132 due to thrombosis, log rank 5.17 (p < 0,02). The increasing risk of those repaired after a thrombosis vs dysfunction is 4.2 p < 0,01. CONCLUSIONS: The monitoring of the vascular access by a multidisciplinary team has reached:low rate of thrombosis, high elective number of repairs of the VA, high urgent rescue surgery after a thrombosis and a few number catheter needed and hospitalizations. AVF are associated with greater survival than PTFE. The VA repair due to dysfunction vs thrombosis had a greater survival as well.
Adult↗
Bovine tuberculosis in wild boar (Sus scrofa), red deer (Cervus elaphus) and cattle (Bos taurus) in a Mediterranean ecosystem (1992-2004).
During the last 12 years, an increasing frequency in condemnation of hunted red deer and wild boar carcasses due to the presence of tubercle-like lesions has been observed in Extremadura (Western Spain). Before 1993, tuberculosis was a very rare finding in hunted animals. The current tuberculosis regional prevalence in cattle approaches 0.4% after years of expensive test and slaughter campaigns. It is imperative to investigate the epidemiology of Mycobacterium bovis infection in red deer and wild boar in order to keep a good health status and to maintain the effectiveness of domestic species TB eradication programs. The present paper evaluates the problem in Sierra de San Pedro, estimating the prevalence of TB in wild boar and red deer, the main wild artiodactyls in the area, and domestic cattle since 1992-2004, by the use of a low-cost surveillance method based on detailed pathological inspection of hunted animal carcasses. Microbiology and molecular epidemiology studies on several M. bovis isolates from domestic and wild animals helped to define the interspecies contacts. These findings, as well as recent history of game estates management and descriptive epidemiology field work, throw light on the rise and maintenance of these epizootics.
Animals↗
An epidemiological evaluation of Mycobacterium bovis infections in wild game animals of the Spanish Mediterranean ecosystem.
Recreational hunting of indigenous wild artiodactyls has been one of the most lucrative and rapidly growing industries in Western Spain over the last five years. In the absence of careful ecological management, one consequence of the commercial exploitation of this natural resource has been the appearance of outbreaks of infectious disease; most notably bovine tuberculosis. From the outset of the study in 1997, we have observed a steady increase in prevalence of Mycobacterium bovis (M. bovis) in both species reaching 1.74 (+/-0.17) in deer in 2002 and 2.32 (+/-0.24) in wild boar. The latter species seems to be most severely affected with pulmonary lesions appearing more chronic than those observed in deer. In this study, we describe the epidemiology of M. bovis in European wild boar (Sus scrofa) and Iberian red deer (Cervus elaphus hispanicus) in Extremadura (W. Spain); a region where there are large areas of natural habitat for these species.
Animals↗
Epidemiology of Mycobacterium bovis infections of pigs and wild boars using a molecular approach.
A molecular epidemiological approach was applied to establishing a possible role for the wild boar as a natural reservoir of Mycobacterium bovis in Sierra de Villuercas, Western Spain; an area free of farmed cattle and wild deer populations. Spoligo and VNTR typing were used over a three year period to study the epidemiological relationship between the occurrence of bovine tuberculosis (TB) in extensively bred Iberian pigs and indigenous wild boar. The 37 sampled wild boar showed different degree of calcified granulomatous lesions in retropharyngeal, mediastinal and pulmonary lymph nodes. The 25 sampled Iberian pigs showed calcified lesions, mainly in the respiratory tract. Lesions located in the mesenteric lymph nodes appeared secondarily. M. bovis was isolated from all affected animals. Twenty-five and 37 isolates of M. bovis were obtained from domestic pigs and wild boar, respectively. Our findings provide evidence that supports the possibility of cross infection between wild boar and domestic pig populations. This is contrary to the generally held belief that swine represent an epidemiological dead end host and play no role in the epidemiology of M. bovis.
Animals↗
Comparison of C0 and C2 cyclosporine monitoring in long-term renal transplant recipients.
Recent data show that monitoring cyclosporine A (CsA) concentrations with 2-hour postdose levels (C2) correlates with the incidence of rejection and graft outcome in de novo renal transplant patients. The purpose of the present work was to evaluate the advantage of C2 monitoring after the first year of kidney transplantation. We studied 161 patients, 96 on CsA-prednisone and 65 on triple therapy (Aza or MMF) who had been transplanted for a mean of 103+/-44 months. Mean serum creatinine (SCr) was 1.65+/-0.69 mg/dL, mean C0 was 174+/-44, and C2 was 667+/-194 ng/mL. Patients were classified according to C2 values: >850 (n=29), between 850 and 450 (n=109), and <450 (n=23) ng/mL. Patients with C2 <450 ng/mL displayed higher SCr values (1.97+/-0.99; 1.59+/-0.51; 1.52+/-0.4 mg/dL; P<.001), received lower CsA doses (172+/-54; 207+/-54; 227+/-56 mg/d, P<.01), showed lower C0 levels (155+/-48; 172+/-41; 199+/-45 ng/mL; P< .001), and included more patients on triple therapy (54.5%; 44%; 17.2%; P<.05). We found weak correlations between C0 and C2 (r=0.37), between C2 and CsA dose (r=0.36), and between C0 and SCr (r=-0.37). Among 117 patients followed up for 1 year with several C0 and C2 measurements, the coefficient of variation of C0 was 17% and of C2 was 21%. Graft functional deterioration occurred in 16 patients independent of the differences among the C2 groups, but 7 recipients (43.7%) had C0 <150 ng/mL and C2/C0 >5. We conclude that C2 in monitoring stable patients needs further evaluation.
Azathioprine↗
A low incidence of new-onset insulin-dependent diabetes mellitus using tacrolimus in kidney recipients in Europe.
Employing tacrolimus (Tac) for routine immunosuppression in renal transplantation (RT), produced an incidence of new-onset, insulin-treated, diabetes mellitus (newDM) as high as 20%. More recently, several large multicenter kidney studies using Tac as the primary immunosuppressant have been reported in Europe. Between 1997 and 2001, we performed 155 RTs using Tac (0.2 mg/k/per day, targeting whole blood trough levels <15 ng/mL) with a rapid steroid taper. The acute rejection rate was 13%, and 89% of grafts are still functioning. Only 5 Tac-treated patients not previously requiring insulin needed insulin therapy for > or =30 days (3.2%). Eight separate studies employing Tac in at least one arm (N=2728) have been reported between 1997 and 2002. Tac was combined with azathioprine or MMF, and/or steroids. The incidence of new DM at study end ranged from 2.3% to 8.3%. The only trial with >6% incidence was the first one, using an initial dose of 0.3 mg/kg per day. The most recent studies utilized an initial dose of 0.2 mg/kg per day, targeting whole blood trough levels of <15 ng/mL and a steroid taper, with newDM at <6%. On the basis of these data, we confirm in that the use of Tac as a first-line immunosuppressant in renal transplant patients affords protection against acute rejection with a low level of newDM. The tendency to employ lower oral doses of Tac, lower blood target levels, and a reduced steroid dose appear to minimize glucose disturbances in RT.
Diabetes Mellitus, Type 1↗
Cytomegalovirus infection after renal transplantation: selective prophylaxis and treatment.
We have reviewed our experience in selective cytomegalovirus (CMV) infection prophylaxis and treatment in our renal transplant population. Between 1996 and 2001, 263 cadaveric renal transplant recipients had at least 6 months follow up. Immunosuppression was based on cyclosporine Neoral (n=108) or tacrolimus (n=155). CMV infection prophylaxis (oral acyclovir or gancyclovir at half usual doses) was only prescribed in recipients receiving a CMV positive ve kidney and in recipients treated with OKT3. CMV infection was diagnosed by a positive pp65 antigenemia upon appearance of CMV-related symptoms, leading to specific treatment (IV ganciclovir) only if symptoms were intense or there was visceral involvement. Thus, no preemptive treatment or programmed or periodic antigenemia was performed in any case. Nineteen episodes of symptomatic CMV infection were diagnosed (prevalence 7.2%). The frequency was similar for all immunosuppressive regimens. Only 9 of 19 (47%) of patients were given IV ganciclovir; the others were not treated. All patients survived without apparent complications, relapses, or recurrences. No oral gancyclovir was delivered after IV treatment. Our CMV prophylaxis protocol was limited to high-risk patients, using lower gancyclovir dosages than those usually advocated. It does not include programmed or scheduled search for CMV antigenemia in asymptomatic renal transplant patients. Despite these factors, our CMV infection rate and severity were similar to those reported with more aggressive protocols, with extended prophylaxis, preemptive therapy, or intense surveillance.
Acyclovir↗
[The functions of the community nephrologist and its importance in health care system].
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Community Health Services↗
[Self-perception of health and mortality in elderly from a rural community].
OBJECTIVE: To assess the relationship between self-perception of their health and mortality in a representative sample of persons over 65 in a rural community. DESIGN: Survival study of population with three years observance. SETTING: A non-coastal and rural borough in Galicia. PARTICIPANTS: 408 people over 65, chosen by random sampling. MEASUREMENTS AND MAIN RESULTS: The demographic, social and health (objective and subjective) parameters were determined through an initial survey, with subsequent follow-up to find the date and cause of death should this have occurred. Of the 404 elderly people observed, 67 (16%) died. The main causes of death were diseases of the circulatory apparatus (48%) followed by tumours. Mortality was higher in people who were older, unmarried, didn't drink alcohol, were seriously ill, had restricted mobility, consumed more medicines and had a perception of their health as poor. We found an association between self-perceived health and mortality, after adjustment for age, sex, marital status, educational level and consumption of medicines, only when we looked at the elderly without restricted mobility (RR = 2.3; 95% CI = 1.0-5.3). CONCLUSIONS: We think that self-perception of health status can be an overall indicator of health, linked to mortality, and that in the elderly with good mobility, this association can be independent of age, sex, educational level, marital status and consumption of medicines.
Aged↗
Electron microscopic contrast of the cytoskeleton and junctional complexes of intestinal epithelial cells by ethanolic phosphotungstic acid.
After glutaraldehyde fixation and treatment with ethanolic phosphotungstic acid (E-PTA) before plastic embedding, sections of rat large intestine showed a characteristic electron contrasting pattern in epithelial cells. The axis of microvilli, terminal web, a thin band below the luminal plasma membrane, centrioles and junctional complexes (tight junctions, adherens junctions, and desmosomes) appeared highly contrasted. In addition to protein components of microfilaments and intermediate filaments, proteins from the junctional complexes could also be implicated in the contrasting reaction with E-PTA. Mitochondrial membranes, chromatin masses, and nucleoli of enterocytes showed considerable electron density, whereas no reaction was found in the glycocalyx and mucin content of goblet cells. The clear visualization of cytoskeleton elements and junctional complexes by E-PTA contrasting represents a simple and valuable method for studies on the normal and pathological organization of these structures in epithelial cells.
Animals↗
Seminal plasma proteins revert the cold-shock damage on ram sperm membrane.
Ejaculated ram spermatozoa, freed from seminal plasma by a dextran/swim-up procedure and exposed to cold shock, were incubated with ram seminal plasma proteins and analyzed by fluorescence markers and scanning electron microscopy. Seminal plasma proteins bound to the sperm plasma membrane modified the functional characteristics of damaged spermatozoa, reproducing those of live cells. Scanning electron microscopy showed that the dramatic structural damage induced by cooling reverted after incubation with seminal plasma proteins. Assessment of membrane integrity by fluorescence markers also indicated a restoration of intact-membrane cells. This protein adsorption is a concentration-dependent process that induces cell surface restoration in relation to the amount of protein in the incubation medium. Fractionation of ram seminal plasma proteins by exclusion chromatography provided three fractions able to reverse the cold shock effect. Scanning electron microscopy also confirmed the high activity of one fraction, because approximately 50% of cold-shocked sperm plasma membrane surface was restored to its original appearance after incubation. Differences in composition between the three separated fractions mainly resulted from one major band of approximately 20 kDa, which must be responsible for recovering the sperm membrane permeability characteristic of a live cell.
Adsorption↗
Resistance to bacillus thuringiensis Cry1Ac toxin in three strains of heliothis virescens: proteolytic and SEM study of the larval midgut
In a previous study, we demonstrated that resistance to Bacillus thuringiensis toxins in Heliothis virescens might be related to differences in the composition of the proteolytic extracts from insect midgut. There, we found specific proteolytic bands present in the gut extracts of the resistant strain and absent from the susceptible one. Here we report related facts using a new resistant strain (KCB) and a cross between the two strains used in our previous study. As would be expected, no quantitative differences in total proteolytic activity were found between the strains, although qualitative differences related to the presence or absence of specific proteolytic activity bands using SDS-PAGE could be responsible for the observed resistance phenomenon. Moreover, an SEM study made at different time intervals after intoxication shows that in the initial hours following intoxication, both the susceptible and the resistant strains show significant damage to the midgut epithelium. In the interval between 3 and 48 h, however, the resistant strain recovered such that by 48 h it had fully recovered whereas the susceptible strain did not. Arch. Copyright 1999 Wiley-Liss, Inc.
Journal Article↗
A barium method for the cytochemical detection of sulfated glycosaminoglycans in mast cells and basophilic leukocytes.
Barium ions precipitate inorganic as well as organic sulfate compounds and they can be detected by a reaction with sodium rhodizonate. In this work, we describe the use of a barium method for the selective demonstration of sulfated glycosaminoglycans in cytoplasmic granules of mast cells and basophilic leukocytes. Methanol-fixed smears of mouse peritoneal mast cells and rat bone marrow basophils were treated with 5% BaCl2 for 10 min, followed by staining with either 0.2% sodium rhodizonate in 50% ethanol for 2 h at 60 degrees C, or 0.01% brilliant green in distilled water for 1 min. Light microscopic observation revealed a strong staining reaction of the cytoplasmic granules of these cell types, which was more selective when using sodium rhodizonate. Control smears treated with BaCl2 or sodium rhodizonate alone, and those subjected to methylation/extraction of sulfate groups before staining remained unstained. The selective binding of barium ions to mast cell granules was established with scanning electron microscopy using a backscattered electron detector, and confirmed by energy dispersive X-ray microanalysis as well as element mapping.
Animals↗
Nandrolone decanoate reduces serum lipoprotein(a) concentrations in hemodialysis patients.
We have studied the changes in the lipid profile of 14 chronic hemodialysis patients receiving a 6-month cycle of nandrolone decanoate as treatment for anemia. Nandrolone decanoate was administered in a weekly intramuscular dose of 200 mg and resulted in an increase in the hemoglobin concentration (baseline, 7.9 +/- 0.9 g/dL; month 6, 10.8 +/- 1.7 g/dL; P < 0.001, ANOVA) and also produced relevant modifications in the lipid concentrations. The most significant finding was a decrease in the concentration of lipoprotein(a) [Lp(a)]: baseline, 19.8 mg/dL (median), month 2, 10.6 mg/dL; month 4, 8.7 mg/dL; and month 6, 7.1 mg/dL (P < 0.001, Friedman). Other lipid changes induced by nandrolone decanoate were an increase in the concentrations of apolipoprotein B (P < 0.02, ANOVA) and triglyceride (P = NS, ANOVA) and a decrease of high-density lipoprotein (HDL) cholesterol (P < 0.001, ANOVA) and apolipoprotein A-I (P = NS, ANOVA). The decrease in HDL cholesterol was at the expense of the HDL2 cholesterol subfraction, whereas HDL3 remained unchanged. These lipid modifications were reversible; 4 months after nandrolone decanoate withdrawal, the lipid concentrations were similar to the basal values. The changes in Lp(a) levels did not correlate with those of hemoglobin or the other lipid parameters, suggesting that the underlying mechanisms are unrelated. Our findings could be clinically relevant if confirmed by further studies.
Aged↗
Malignant pheochromocytoma, still a therapeutic challenge.
For cases of malignant pheochromocytoma the prognosis is poor and experience with its treatment remains limited. We present a case of a hypertensive 16 year old woman with malignant pheochromocytoma and a good treatment response. Bone metastases appeared 6 months after the first resection. Local excision of the thoracic vertebrae metastases and palliative radiation therapy were performed, after which she received twelve cycles of cyclophosphamide, vincristine, and dacarbazine. Sixteen months later the patient remains asymptomatic without biochemical catecholamine activity.
Adolescent↗
An unusual case of villous adenoma of the ampulla Vateri in a renal allograft recipient.
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Adenoma, Villous↗
Satisfactory control of secondary hyperparathyroidism with low-calcium dialysate in patients not receiving vitamin D.
The use of a dialysate calcium concentration of 2.5 mEq/1 for patients not receiving vitamin D is controversial. Therefore, it has been suggested that oral calcium supplements might be sufficient to avoid a negative calcium balance which could result in a worsening of secondary hyperparathyroidism. In order to clarify these aspects, we reduced the dialysis fluid calcium level in 26 patients on chronic hemodialysis with a dialysate calcium concentration of 3.25 mEq/l, all of them receiving low doses of calcium carbonate and aluminum hydroxide. No patient received supplements with vitamin D during the previous 2 years. These patients have been dialyzed using a dialysate calcium concentration of 2.5 mEq/l for 1 year. Gradually we increased the dose of calcium carbonate and decreased the dose of aluminum hydroxide to maintain the predialysis serum calcium and phosphate concentrations between 8-10 and 4-6 mg/dl, respectively. After 1 year of hemodialysis with a low-calcium dialysate (2.5 mEq/l), the oral dose of calcium carbonate was increased from 3.5 +/- 2.6 to 9.2 +/- 5.6 g/day (p < 0.001). In 22 patients (85%) the aluminum hydroxide was stopped, and in the remaining 4 cases the dose was lowered. The reduction in the dialysate calcium concentration did not increase the incidence of hypercalcemia or hyperphosphatemia. In the whole group, we did not observe a significant variation in the levels of intact parathyroid hormone (iPTH; 324 +/- 123 vs. 311 +/- 256 pg/ ml) or alkaline phosphatase (230 +/- 115 vs. 224 +/- 127 U/l), although there was a reduction in the serum aluminum concentration (33 +/- 31 vs. 21.8 +/- 20.2 micrograms/l; p < 0.001). We analyzed the evolution of iPTH in each case. In 15 patients (58%) the iPTH concentration decreased, in 6 cases (23%) it remained stable, and in only 5 subjects (19%) there was an increase (2 of them did not take the oral calcium dosage recommended). In conclusion, a low dialysate calcium concentration (2.5 mEq/l) is safe for most patients not receiving vitamin D. But adherence of patients to high doses of oral calcium supplements is absolutely necessary.
Adult↗