Can the genetic variability of Blastocystis sp. be associated with the climatic region of its human carriers?

Blastocystis sp. is a widespread microorganism that colonizes the intestinal tract of several animals, including human beings, while its pathogenic role in humans is still under debate. The objective of the present study was to describe the frequency of Blastocystis sp. subtypes (STs) and their genetic variation within and among samples recovered from scholars inhabiting two rural villages with tropical climates and compare this information with previously documented data from arid and temperate zones in Mexico. Blastocystis sp. positive samples and ST identification were achieved by coprological analysis screening and Polymerase Chain Reaction-sequencing, respectively. Classical population genetics indexes (nucleotide diversity (π), haplotype polymorphism (θ), gene flow (Nm), genetic differentiation (ST), and Tajima's D) were calculated by comparing the sequences here obtained (n = 42) and those from previous studies from the arid (n = 80) and temperate (n = 61) climates from Mexico. Although Blastocystis sp. was the parasite most frequently found between 33% and 26% in both communities, only STs 1-3 were found. Haplotype network inference of Blastocystis sp. STs showed different haplotype profiles among STs vs. climate zones, although no specific haplotypes were identified for any particular climatic zone. Population genetics indexes showed different values within STs and climate zones (π and θ values ranged from 0.004 to 0.147; Nm > 4 and ST from 0.006 to 0.12). Our results show that Blastocystis sp. subtypes exhibit a different genetic variability profile according to the climate zone, suggesting a balancing process between the genetic variability within the Blastocystis sp. subtype and the number of haplotypes identified in each climate.

Clinical usefulness of lanthanum carbonate for serum phosphate control in difficult patients.

BACKGROUND: The adequate control of phosphataemia is of major importance in end-stage renal disease patients on maintenance dialysis. Recently, lanthanum carbonate (LC) has been added to the phosphate binder armamentarium. To our knowledge, no studies have yet evaluated the usefulness of this drug in uncontrolled hyperphosphataemic patients. METHODS: This was a 6-month prospective observational study. Patients on chronic hemodialysis who had previously failed to achieve serum phosphate control were enrolled. Thirty-four patients (i.e. 11% out of 305 from three dialysis units) met the inclusion criteria. Lanthanum carbonate was introduced and titrated to achieve serum phosphate control, according to the KDOQI guidelines. Clinical targets, gastrointestinal symptoms, and patients' satisfaction with therapy were assessed at baseline and after 6 months. RESULTS: Eight patients (23.5%) were withdrawn from the study due to side effects. In the remaining patients, serum phosphate level significantly decreased from 5.8 to 4.4 mg/dl and calcium-phosphate product also decreased significantly from 55.6 to 41.8 mg(2)/dl(2). The average number of all phosphate binder tablets taken per day was reduced from 6.7 to 4.7. Evaluation scores of dyspeptic symptoms and of patient's satisfaction with therapy also improved: from 7.5 to 5.3 and from 6.6 to 8.1, respectively. CONCLUSIONS: The introduction of LC improved serum phosphate control in over 70% of these "difficult patients". A lower pill burden was also obtained, which might help to simplify treatment and increase patients' compliance. Dyspeptic symptoms and overall satisfaction with treatment also improved.

[Analysis of psychological factors influencing peritoneal dialysis selection]. / Análisis de la influencia de los factores psicológicos en la elección de diálisis peritoneal.

BACKGROUND: Peritoneal dialysis (PD) is not frequently used in our setting. OBJECTIVE: To analyze the psychological factors involved in the choice of renal replacement therapy (RRT). MATERIAL AND METHODS: A prospective observational study of stable patients without cognitive or sensory deficits who were informed about RRT from January 2004 to July 2006 and agreed to participate. The patients were given and completed the Beck Depression Inventory and the Eysenck personality questionnaire. Clinical and sociodemographic data and RRT choice were recorded. End of follow-up: 2007/10/31. RESULTS: 44 patients were studied: age, 65.4 +/- 13.1 years, 48% male, 34% diabetic. When choosing RRT, 36% of patients had symptoms of depression. Neither depression symptoms nor personality traits were related to the choice of dialysis type. The youngest patients chose PD (41%). After a mean followup of 8 +/- 8 months, 70% of patients started RRT (68% haemodialysis [HD], 32% PD). None of the patients who chose HD changed their mind, but 3 of the 13 patients (23%) who chose PD finally commenced HD, usually in the context of a worsening of the disease. Half of the patients with depression symptoms when choosing PD and a third of the patients with higher levels of neuroticism changed their decision and finally opted for HD. CONCLUSIONS: When choosing RRT, the prevalence of depression symptoms is high. Neither depression nor personality traits influenced the initial choice of RRT, although these factors may be involved in subsequent changes to the decision.

Population-based survey of taeniasis along the United States-Mexico border.

Taenia solium and T. saginata are zoonotic tapeworms of substantial medical and economic importance. Although human taeniasis is widely recognised as an endemic problem in Mexico, its presence in the United States is poorly understood. The first population-based study to estimate the prevalence of human infection with Taenia tapeworms along the Texas-Mexico border has recently been conducted. Households were interviewed in the Texan city of El Paso and in the neighbouring Ciudad Juárez, in Mexico. Faecal samples from household members were then checked for Taenia eggs by flotation and/or for Taenia copro-antigens in an ELISA. The overall prevalence of taeniasis in this border region was found to be 3% but, compared with the residents of Juárez, El Paso residents were 8.6-fold more likely to be tapeworm carriers. The interviews revealed some important differences between the two study sites, particularly the more frequent use of anthelminthic drugs on the Mexican side of the border. These findings have implications in terms of the planning of effective health-education campaigns to decrease the prevalence of taeniasis in the human populations along the Texas-Mexico border.

[Prognostic significance of hemoperitoneum in peritoneal dialysis]. / Significado pronóstico del hemoperitoneo en diálisis peritoneal.

According to previous reviews, hemoperitoneum episodes appear in 6.1-8.4% of the peritoneal dialysis patients, and they are severe in a 20% of them. Due to the absence of severe hemoperitoneum in our peritoneal dialysis program, we retrospectively reviewed hemoperitoneum non-related with abdominal surgery or catheter placing. We analyzed its incidence, etiology, prognostic and clinical outcome, as well as the possible effect of recurrent hemoperitoneum on peritoneal function. A total of 132 patients were treated in our centre during a period of 173 months. Mean age at the beginning of peritoneal dialysis was 59+/-17.1 years, 43.2% were females, and 22.8% of them were menstruating women. Twenty-two patients had at least one hemoperitoneum episode during follow-up, with an incidence of 17%. The mean time interval between the start of peritoneal dialysis and the first hemoperitoneum episode was 0.66+/-0.94 years (range: 0.01-3.20 years). 73% were women. Most cases (59%) were due to menstruation. Remarkably, all the menstruating women presented hemoperitoneum at least once with a high incidence of recurrent episodes. The other hemoperitoneum episodes were mainly of unknown etiology (32% of patients), being this one the main cause in males. We only observed two more cases: a male who presented hemoperitoneum related to dicumarinic overdose and a female who presented hemoperitoneum due to mesenteric ischemia. All the 22 patients had a favourable outcome, except for the woman with mesenteric ischemia, what represented an incidence of 4.5% of severe hemoperitoneum. No significant association was found between episodes of hemoperitoneum and aspirin treatment, dicumarinic treatment or the presence of coagulopathy. There was no association either between recurrent hemoperitoneum and the number of peritonitis episodes, peritoneal function or technique survival. In conclusion, hemoperitoneum is a common and usually benign problem in peritoneal dialysis patients, frequently due to retrograde menstruation, and no deleterious long-term effects were found in patients with recurrent hemoperitoneum.

[Advance directives in chronic dialysis patients]. / Documento de voluntades anticipadas de pacientes con insuficiencia renal crónica terminal en tratamiento sustitutivo mediante diálisis.

BACKGROUND AND OBJECTIVE: Knowledge of the life-sustaining treatment preferences of the dialysis patients would be extremely helpful to substitute decision-makers and nephrologists in deciding whether to continue or stop a treatment. The population of the Mediterranean countries show this opinion with less frequency. The objective of this study is: 1) the knowledge of the patient's view for the advance directives; it may increase the likelihood to get the correct decisions of the staff when complications break the normal course of chronic dialysis, and 2) the statement of the advance directives. MATERIAL AND METHOD: We distributed 135 questionnaires to patients with chronic renal failure in dialysis treatment of the Sabadell's Hospital to explore demographic information about responders and not-responders and explore the rate of questionnaires was completed about the cardiopulmonary resuscitation, respirator, tube feeding and dialysis in case of coma, persistent vegetative state, severe dementia and terminal illness. We explore about the representative of patients and in case of not-responders about the cause to not answer. RESULTS: Sixty-four of 135 patients (47,8%) did not want cardiopulmonary resuscitation, respirator, tube feeding or dialysis in case of coma, persistent vegetative state, severe dementia or terminal illness. Compared with patients who wanted the treatments, those who did not were older (71,2 versus 62,2 years; p = 0.002). There was no difference in the other demographic questions, including sex (p=0.674), cause of kidney failure (p=0.815), comorbid conditions (p=0.824), and social status (language of questionnaire -0.155- and standard of education -0.288-). Advance care planning does not occur solely within the context of the physician-patient relationship; the respondents reported the representative in the family, essentially. The patients not-responders doesn t want to think in those situations and also they show doubt about the interpretation of their answers. CONCLUSIONS: near 50% patients in chronic dialysis want to stop certain treatments in case of resuscitation cardiopulmonary, coma, persistent vegetative state, severe dementia or terminal illness. The older patients want the limitation of treatments more frequently.

[Choosing not to dialysis in chronic renal failure in stage V (Renal Failure). Evolution of the characteristics of patients between 1992-1995 and 2000-2003]. / Elección de no diálisis en insuficiencia renal crónica en estadio V (fallo renal). Evolución de las características de los pacientes entre 1992-1995 y 2000-2003.

BACKGROUND: The incidence of chronic renal failure increase with the age. The selection of patient to dialysis has been increasing in spite of the high comorbidity. Moreover, in our clinical practice the aged patient is not contraindicated to dialysis. However, in the nephrology clinical practice not all the patients start the treatment with dialysis. OBJECTIVE The aim of our study has been to compare the characteristics of the patients who had not been dialyzed between the periods 1992-1995 and 2000-2003 to analyze the trend of the nephrology clinical practice. MATERIAL AND METHODS: Comparative study of the characteristics and the evolution of patients with chronic renal failure in stage V, (renal failure) not incorporated to dialysis in one hospital during four years between the periods the 1992-1995 ( period A) and 2000-2003 (period B). RESULTS: Start dialysis (period A versus period B): 116 patients, age 59.9+15.5 years vs. 229 patients, age 64.0+15.8 years (p<0.05). Non-dialysis (period A versus period B): 38 patients, age 77.5+9.3 years vs. 37 patients, age 81.7+6.2 years (p<0.01). Renal function: serum creatinina 7.4+2.4 mg/dl vs. 5.3+1.2 mg/dl (p<0.001), MDRD estimate glomerular filtration 6.9+2.4 mg/dl ml/min/1.73 m2 vs. 10.0+2.3 ml/min/1.73 m2 (p<0.001). Primary renal disease: unknown etiology 31.5 % vs. 24.3 %, nephroangiosclerosis 23.6 % vs. 32.4 %, diabetes 28.9 % vs. 21.6 %. Functional status: dependent patients 34.2 % vs 83.8 % (p<0.001). The principal reason for non-dialysis were: personal decision: 26.3 % vs. 35.1 %, dementia 15.8 % vs. 29.7 %, brief life expectancy because of serious co-existing diseases 13.1 % vs. 21.7 % and serious chronic illness with inability for themselves care 44.7 % vs. 13.1 %. Comorbid conditions: 2.3+1.0 vs. 3.0+1.5 (p<0.05). Survival: 55+168 days vs. 168+236 days (p<0.001). CONCLUSION: Most of the patients that don't begin dialysis are elderly together with a poor functional capacity and with more autonomy in their decisions. The identification of patients with renal failure (stage V) was detected early in the last period than in the following one. The conservative management of non-dialyzed uremic patients is a significative nephrology clinical practice due to more survival of those persons.

[Secondary amyloidosis (AA-type) due to localized cutaneous vasculitis]. / Amiloidosis secundaria asociada a vasculitis cutánea localizada.

We report a case of a 49 year old man, diagnosed soon after the outcome of casual proteinuria, of AA-type amyloidosis in relation to small and medium vessel cutaneous vasculitis without systemic involvement. This combination is a rare entity and only two cases of cutaneous hypersensibility vasculitis complicated with AA-type amyloidosis had been reported. We describe the results of the use of several immunosuppressive drugs during four years follow up with temporally total remission of the disease.

Antibody responses and epitope specificities to the Taenia solium cysticercosis vaccines TSOL18 and TSOL45-1A.

Taenia solium is a cestode parasite that causes cysticercosis in humans and pigs. This study examined the antibody responses in pigs immunized with the TSOL18 and TSOL45-1A recombinant vaccines against T. solium cysticercosis. Immunization with these proteins induced specific, complement-fixing antibodies against the recombinant antigens that are believed to be associated with vaccine-induced protection against T. solium infection. Sera from immunized pigs were used to define the linear B-cell epitopes of TSOL18 and TSOL45-1A. Prominent reactivity was revealed to one linear epitope on TSOL18 and two linear epitopes on TSOL45-1A. These, and oncosphere antigens from other taeniid cestodes, contain a protein sequence motif suggesting that they may show a tertiary structure similar to the fibronectin type III domain (FnIII). Comparison of the location of linear antigenic epitopes in TSOL18 and TSOL45-1A within the proposed FnIII structure to those within related cestode vaccine antigens reveals conservation in the positioning of the epitopes between oncosphere antigens from different taeniid species.

[Allopurinol-induced chronic granulomatous interstitial nephritis]. / Nefritis intersticial granulomatosa cronica por alopurinol.

Although drug induced interstitial nephritis is a relatively common cause of renal failure,granulomatous forms remain a rare condition. The development of a chronic granulomatous interstitial nephritis due to allopurinol is exceptional, only three cases have been described previously. We report on a patient who presented a granulomatous interstitial nephritis after 10 years of allopurinol administration (300 mg/day). At diagnosis, he had end stage renal disease and dialysis treatment was needed. Two months after drug withdrawal and on corticoid treatment a slow recovery of renal function was observed, allowing the interruption of dialysis. Two years after, the creatinine clearance is 23 ml/min,being dialysis free. We discuss the differential diagnosis of granulomatous interstitial nephritis and its rare association with allopurinol treatment.

[Patients with end-stage chronic renal insufficiency on programmed withdrawal from dialysis]. / Pacientes con insuficiencia renal crónica terminal retirados de diálisis bajo protocolización.

UNLABELLED: The voluntary discontinuation of dialysis by patients is a common mode of death in dialysis programmes. Unfortunately the Spanish experience has not been related in the nephrological literature. Initiation of, and withdrawal from, dialysis pose ethical questions for medicine in the 21st century. The dialysis population is aging and they have multiple medical problems. The choice may be between prolongation of quantity or quality of life. We evaluated a protocol for initiation of dialysis in patients with end stage renal failure and their subsequent withdrawal. We determined the factors predicting withdrawal of dialysis and revised the protocol to take account of these. We carried out an opinion poll of doctors and nurses about the effectiveness of the protocol. We studied prospectively the reasons for death of patients in the last seven years. RESULTS: Thirty patients were withdrawn from dialysis out of 116 who died during treatment by hemodialysis or continuous ambulatory peritoneal dialysis (CAPD) in the last seven years. Vascular nephropathy is the principal disease predicting withdrawal from dialysis; the main precipitating cause is mental incapacity. The availability of a protocol for withdrawal of dialysis is well received by doctors and nurses and it engenders moral and legal calm when facing difficult decisions. Twenty-six per cent of deaths on regular dialysis are the result of withdrawal of treatment.

Characterization of GP39-42 and GP24 antigens from Taenia solium cysticerci and of their antigenic GP10 subunit.

Diagnosis of neurocysticercosis is performed by Western blotting with an enriched fraction of glycoproteins (LLGP). GP39-42 and GP24 are immunodominant antigens. These antigens were electroeluted and characterized by biochemical methods. When GP39-42 or GP24 were reduced, a band of 10 kDa (named GP10) appeared; this band was also analyzed. The most abundant amino acids in the three GPs were lysine, phenylalanine, asparagine, glycine, and leucine. The amino terminal portion was sequenced, and the following order was obtained for the three GPs: EKNKPKNVAXSTKKGYEYVXEF. The glycan portion was 8.4%, 18.2%, and 18.3% in GP39-42, GP24, and GP10, respectively. The three GPs contained mannose, N-acetyl-D-glucosamine, and galactose. GP39-42 and GP24 seem to be oligomeric forms of GP10. When reduced LLGP was reacted with samples obtained from patients with neurocysticercosis or pigs with cysticercosis, a band corresponding to GP10 was always observed. Furthermore, hyperimmune serum from rabbits immunized with GP39-42 or with GP24 recognized GP10 as well as GP39-42 and GP24. The data obtained in this paper suggest that GP10 might be a useful tool for diagnosis.

Effects of polyunsaturated fatty acids on rat glomerulosclerosis induced by hypercholesterolaemic diet.

Association between lipids and renal disease has been reported recently. Its pathogenic mechanisms remain unknown. The aims of this study were to establish: (1) if a cholesterol-rich diet, alone or associated with nephrectomy, produces nephropathy; and (2) if a treatment with omega-3 polyunsaturated fatty acids (PUFA) reduces glomerulosclerotic lesions. Sixty Sprague-Dawley rats were randomized in two different groups: (A) sham operated rats and (B) uninephrectomized rats. Rats in both groups were divided into three subgroups (A1-3, B1-3) according to the diet they were fed: normal chow diet, cholesterol-rich diet (4.5%) or cholesterol-rich diet supplemented with omega-3 PUFA. Twenty weeks later, serum creatinine, creatinine clearance, serum cholesterol, triglycerides, albumin, proteinuria, mesangial cell score and focal glomerulosclerosis were assessed. Results showed that a cholesterol-rich diet significantly increased serum cholesterol, proteinuria and glomerular lesions and decreased creatinine clearance, especially in nephrectomized rats. Glomerular lesions, serum cholesterol and proteinuria ameliorated when cholesterol-rich diet was supplemented with PUFA. Hypertension was noticed only in nephrectomized rats following a normal chow diet. Simple correlation analysis showed that glomerulosclerosis correlated with renal weight, blood creatinine, cholesterol and proteinuria. In spite of some significant differences in urinary prostaglandins, no correlation with glomerular lesions was found. Multiple logistic regression analysis showed that cholesterol and proteinuria were independent risk factors for induction of glomerular sclerosis. In conclusion, a diet rich in cholesterol induces glomerulosclerosis, especially if it is associated with unilateral nephrectomy. Omega-3 PUFA administration reduces serum cholesterol, proteinuria and glomerular injury.