PubMed Health⌕ Search

Biomedical subjects

R Correa-Rotter

Publications and source records attributed to R Correa-Rotter.

At least 55 records · Page 3Linked to original sources
PubMed1991

Glomerular renin synthesis and storage in the remnant kidney in the rat.

The intrarenal renin-angiotensin system can exert local control of the nephron and its circulation. In the subtotally nephrectomized model of chronic renal disease in the rat, angiotensin appears to play a prominent role in glomerular function. Glomeruli in this model demonstrate greater staining for intraglomerular renin by immunofluorescence microscopy than do those in control rats. Glomeruli from remnant nephrons contain increased renin content. Also, glomeruli from remnant nephrons contain an increased proportion of the mRNA for renin. Adriamycin-induced nephrosis did not evoke the same degree of renin staining and did not lead to increased glomerular expression of the renin gene, findings that argue against permselective defects and glomerular trapping as the sole cause of the glomerular renin in the remnant kidney model. Thus, renin synthesis and accumulation occur in the remnant glomerulus and this migration may underlie in part the dependence of glomerular function on the renin-angiotensin system in this model.

Animals↗
PubMed1990

Recovery of HIV antigen in peritoneal dialysis fluid.

We investigated the presence of HIV antigen in dialysis fluid of patients with end-stage renal disease (ESRD) undergoing continuous ambulatory peritoneal dialysis (CAPD), previously known to be infected with this virus. Sixteen adult patients and 6 adult volunteers were included in the study in 4 groups as follows: Group A: 3 patients on CAPD, previously known to be positive for serum HIV antibodies; Group B: 7 patients on CAPD, serum HIV negative; Group C: 6 AIDS patients without renal disease; and Group D: 6 healthy volunteers. Of the 3 patients of Group A, the HIV-1 Ag was positive in dialysis fluid in only 2. In 1, serum Ab and Ag were present, while in the others only serum Ab was detected. The samples from Group B were all negative for the viral antigen in dialysis fluid. We conclude that dialysis fluid of HIV-infected patients may contain the Ag and is therefore potentially infective. The presence of the HIV antigen was not constant, and was not related to antigenemia. It is possible that the presence of the Ag depends on local factors that influence viral replication or to alterations in the permeability of the peritoneal membrane. We discuss other possible factors that could influence the presence of viral Ag in peritoneal dialysis fluid.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Effect of rapamycin on cytokine profile in kidney transplant recipients treated with triple drug therapy.

UNLABELLED: The aim of this study was to explore differences in the cytokine profile among de novo kidney transplant recipients treated with either Rapamycin (Rapa) + cyclosporine (CsA) + prednisone (P) or CsA + azathioprine (Aza) + P. PATIENTS AND METHODS: Among the 13 adult kidney transplant recipients studied, seven received Rapa + CsA + P while the remaining six received CsA + Aza + P with their living donors serving as controls (n = 13). Spontaneous production of IL-2, IFNgamma, IL-10, and TGF-beta were measured by ELISA in supernatants from 24-hour cultured unstimulated peripheral blood mononuclear cell (PBMC) at time zero (the day before the transplant), and at 3 and 6 months posttransplant. Cytokines were also measured 1 month after CsA withdrawal in the Rapa + CsA + P group. RESULTS: From time zero to the end of the study, IL-2, IFNgamma, and IL-10 were present at low or undetectable levels in all three groups. TGF-beta tended to increase in supernatants from patients under Rapa + CsA + P at 6 months posttransplant and at 1 month after CsA withdrawal without correlation to Rapa blood levels. TGF-beta remained stable throughout the study period for patients included in the CsA + Aza + P group. There was no difference in this cytokine level between these study groups at any given time. CONCLUSIONS: This study showed no differences in the spontaneous cytokine profiles evaluated in patients treated with both therapeutic schemes.

Adult↗
PubMedDate not supplied

Peritoneal protein loss in patients with high peritoneal permeability: comparison between continuous ambulatory peritoneal dialysis and daytime intermittent peritoneal dialysis.

BACKGROUND: Dialysate protein loss is involved in the etiology of hypoalbuminemia and malnutrition on continuous ambulatory peritoneal dialysis (CAPD). Patients with high peritoneal membrane permeability had the lowest serum albumin (Alb) and highest dialysate protein concentrations and achieved higher small solute dialysis/plasma equilibration in a shorter time than patients with low peritoneal transport. The aim of this prospective crossover study was to evaluate whether protein loss might be decreased in patients with high peritoneal permeability on short dwell-time (DT) peritoneal dialysis. METHODS: Five high and nine high-average peritoneal transport patients were subjected to the following sequential dialysis schemes (four exchanges/day, glucose 1.5%): scheme A, three daytime exchanges (4-6 h DT) and one nightly (8-12 h DT) for 2-3 days, scheme B, 3-h DT each and dry peritoneum at night during 5 days, a wash-out period similar to scheme A, and scheme C, 2-h DT each and dry peritoneum the remainder of day and night during 5 days. Dialysate Alb, IgG, IgA, and IgM losses and adequacy of dialysis were evaluated at the end of each scheme. RESULTS: Dialysate IgM was not detected. All protein losses were reduced with the short DT dialysis schemes; however, dialysis CCl and KT/V(urea) were also decreased. In patients with high peritoneal transport type, the 3-h DT dialysis scheme achieved a reduction in Alb loss without significant reduction of adequacy of dialysis. CONCLUSIONS: Peritoneal Alb, IgG, and IgA losses are significantly reduced in patients with high peritoneal permeability on short dwell-time dialysis and extended dry periods. However, a reduction of dialysis contribution to small solute clearances was also observed, Three-hour dwell-time dialysis may be particularly useful in patients with high peritoneal transport type, as it tends to reduce peritoneal protein loss without notably reducing adequacy of dialysis.

Adult↗
PubMedDate not supplied

Ascites fluid of nephrotic rats: sodium dodecyl sulphate-polyacrylamide gel electrophoresis protein pattern and the renin-angiotensin system.

1. The concentration of renin and angiotensinogen (Ao) and the activity of angiotensin I-converting enzyme (ACE) was measured in the ascites fluid of nephrotic rats obtained 8 days after puromycin aminonucleoside (PAN) injection. 2. Ascites fluid, serum and urine proteins of these rats were analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). 3. Renin, Ao and ACE were found in the ascites fluid and the percentage of the ratio ascites fluid/(plasma or serum) ranged from 5.9 to 9.9%. The electrophoretic analysis revealed that the ascites fluid contained low (Mr < 66 kDa) and high (Mr < 66 kDa) molecular weight proteins. Albumin and six proteins higher than 66 kDa were present both in the ascites fluid and in serum from nephrotic rats. 4. Data from the study suggest that some proteins in the ascites fluid, including renin, Ao and ACE, come from the plasma. It is possible that the loss of renin, Ao and ACE to the ascites fluid may be playing a role in the metabolic alterations of these three proteins in PAN-nephrotic rats.

Angiotensinogen↗
PubMedDate not supplied

Analysis of the peritoneal equilibration test in Mexico and factors influencing the peritoneal transport rate.

OBJECTIVE: To validate the peritoneal equilibration test (PET), establish reference values in the Mexican population, compare our results with those reported by Twardowski et al., and analyze the influence of some factors on the peritoneal transport rate (PTR). DESIGN: Retrospective, cross-sectional study. PATIENTS: Eighty-six PETs were performed in 45 female and 41 male patients; 35 of the patients were diabetics. Creatinine D/P and glucose D/D0 ratios were calculated and compared with those from Twardowski et al. In a multivariate analysis, age, gender, diabetes mellitus (DM), time on dialysis, and peritonitis rate were considered as independent factors influencing the PTR. RESULTS: Creatinine D/P and glucose D/D0 ratios at 4 hours were not significantly different from those reported by Twardowski et al. Creatinine D/P at 4 hours was not different between DM and non-DM patients when the rate of peritonitis and time on dialysis were not taken into account. Multivariate analysis did not result in any significant model predicting the creatinine D/P at 4 hours. CONCLUSIONS: PET validation is reported for the first time in a Latin American population. The PET results of this study are similar to those in the literature. We found that DM, peritonitis rate, time on dialysis, age, and gender did not clearly influence the PTR.

Adolescent↗
PubMedDate not supplied

[Idiopathic ascites associated with hemodialysis. Case report and literature review].

BACKGROUND: Idiopathic dialysis ascites (IDA) is an uncommon disease characterized by the absence of a cause that can explain its presentation. CASE REPORT: Thirty year old female, with diabetic nephropathy under chronic hemodialysis, with massive ascites. Treatment with intensive ultrafiltration was non-successful, and we had poor clinical results with consecutive paracentesis. The study of ascitic fluid was normal. We discarded cardiovascular, hepatic, infectious, neoplastic, and metabolic etiologies and laparoscopy with hepatic and peritoneal biopsies were non-diagnostic. Finally, after renal transplantation, a rapid decrease of the ascites was observed and the diagnosis of IDA was established. DISCUSSION: IDA is a rare entity that does not seem to be related with uremia as it is usually present after the start of hemodialysis. Malnutrition and hypoproteinemia are frequently associated and could be part of the etiology of IDA, which explains the lack of response to ultrafiltration and salt restriction, usual treatment for ascites control. The pathophysiological explanation of the dramatic response of this patients to renal transplantation is unclear.

Adult↗
PubMedDate not supplied

Correlation between peritoneal equilibration test and dialysis adequacy and transport test, for peritoneal transport type characterization. Mexican Nephrology Collaborative Study Group.

OBJECTIVE: The aim of this study was to analyze the correlation between the peritoneal equilibration test (PET) and the dialysis adequacy and transport test (DATT) for peritoneal transport type characterization, and the degree of patients' acceptance for each test. DESIGN: Cross-sectional, observational multicenter study. SETTING: Five referral (tertiary) dialysis centers of institutional practice. PATIENTS: The study included 107 adult continuous ambulatory peritoneal dialysis (CAPD) patients with a prescription of four exchanges of 2 L per day, irrespective of age, gender, cause of end-stage renal disease, time on dialysis, nutritional status, or residual renal function. Patients on immunosuppressive therapy and those with cancer, hepatitis B, or HIV, and those having a peritonitis episode within the previous 30 days, or three or more episodes during the previous 12 months, were excluded. MAIN MEASURES: Peritoneal transport type as classified by creatinine and urea dialysis-to-plasma (D/P) ratios by PET and DATT. RESULTS: Correlation coefficients between D/P ratios for creatinine and urea, obtained for the PET and the DATT, were 0.73 for D/P creatinine and 0.96 for D/P urea. Patients were classified into high, high-average, low-average, and low transport categories according to the mean and standard deviation of D/P creatinine values obtained from the PET at 4 hours. These values showed excellent concordance with those generated from the DATT data (alpha = 0.82, 95% confidence interval 0.67 - 0.93). Nineteen percent of patients showed discordance in their category when classified according to the PET versus the DATT. Patients' acceptance was better for the DATT than for the PET, as evaluated with a questionnaire. CONCLUSION: The DATT is an easy, inexpensive, and reliable test to assess peritoneal transport type, and it also provides information about peritoneal clearance of solutes and ultrafiltration. The DATT has better patient acceptance than the PET. Since the DATT has only been validated for patients on a fixed CAPD daily schedule of 4 x 2 L, the results should be confined only to patients receiving such a prescription.

Adolescent↗
PubMedDate not supplied

Relationship between fill volume, intraperitoneal pressure, body size, and subjective discomfort perception in CAPD patients. Mexican Nephrology Collaborative Study Group.

OBJECTIVE: To determine changes in intraperitoneal pressure (IPP) when dialysate fill volume is increased from 2.0 L to 2.5 L to 3.0 L per exchange, and to evaluate the relationship with subjective discomfort perception. DESIGN: Cross-sectional survey. SETTING: Seven Mexican hospital-based dialysis centers. PATIENTS: Eighty-one adult patients on continuous ambulatory peritoneal dialysis (CAPD) without restriction criteria for age, gender, or time on dialysis, were studied. Patients seropositive for HIV or hepatitis B, and those with cancer or receiving immunosuppressive drugs were excluded. Participants were studied as outpatients. MAIN MEASURES: Blindly and in random order, 2.0-, 2.5-, and 3.0-L volumes of dialysate were infused consecutively. Body surface area (BSA) was calculated from patient height and weight. IPP was assessed with the patient lying supine, measuring the height of the dialysate column inside the peritoneal dialysis bag tubing. Blood pressure and subjective discomfort perception (using a visual analog scale of 0-100 mm) were also evaluated and registered after each of the three exchanges. RESULTS: The IPP rose with each increase of dialysate volume and was higher in males than in females for each fill volume level. For males IPP was 18.9 +/- 6.9, 20.8 +/- 7.1, and 22.9 +/- 7.5 cm H2O; and for females it was 16.5 +/- 5.7, 18.4 +/- 5.5, and 19.7 +/- 6.2 cm H2O for 2.0-, 2.5-, and 3.0-L fill volumes respectively (p < 0.01 among fill volumes and between genders). Intraperitoneal pressure showed significant negative correlation with the fill volume corrected for patient body size as reflected by the dialysate volume/ BSA ratio (r= -0.393, p < 0.01; r= 0.319, p < 0.01; and r= -0.274, p < 0.02 for 2.0-, 2.5-, and 3.0-L fill volumes respectively). Discomfort score rose as fill volume rose, with a median of 0, 2.5, and 13.0 for 2.0-, 2.5-, and 3.0-L fill volumes respectively (p< 0.001). It is interesting, however, that with 2.5-L and 3.0-L dialysate infusion volumes, 64% and 44% of the patients, respectively, had no discomfort at all. CONCLUSION: Dialysate volume increase is associated with higher IPP, which is modulated by the gender and body size of the patients. Although the mean discomfort score was higher with larger dialysate volumes, there was no significant correlation between discomfort and IPP or the dialysate volume/BSA ratio. Many patients had no discomfort with 2.5-L or even with 3.0-L dialysate infusions; theoretically, they can be treated with larger volumes.

Adult↗
PubMedDate not supplied

[Continuous hemodialysis in the treatment of acute kidney failure].

INTRODUCTION: Continuous replacement therapy of renal function has gained acceptance over the last decade for the treatment of acute renal failure. In the present study we present our experience using continuous hemodialysis (CHD) in our institution. PATIENTS AND METHODS: This is a prospective analysis of the CHD treated patients in the intensive care unit (ICU) of our institution over an 24-month period. CHD was performed through a double-lumen catheter such as Mahurkar. We have performed 28 CHD procedures in 28 patients, from which four were excluded from the analysis. Three patients were excluded as CHD lasted less than 12 hours and one patient because he had chronic renal failure. The studied variables were: heart and respiratory rate, mean arterial pressure, body temperature, APACHE II classification status, arterial gasometry, cell blood count, BUN, creatinine, serum electrolytes, and hepatic enzymes. We also registered urine output, diuretic use, and the mean dose of inotropic drugs employed per day. These variables were obtained at the admittance to the ICU, before the initiation of CHD and after 24 and 48 hours. We also registered age, gender, and final evolution. RESULTS: We evaluated 24 patients with mean age of 58.1 +/- 17.5 years in which CHD was use for a mean time of 4.6 +/- 2.8 days. Total ultrafiltrate was 19.5 +/- 8.4 liters, for a mean of 4.2 liters per day. CHD resulted in improvement of heart and respiratory rate, mean arterial pressure and laboratory variables such as arterial pH, bicarbonate concentration, BUN and potassium. It also decreased significant by the use of inotropic drugs. Five out of twenty-four patients survived (20.8%). The survived patients had significant lower age than the died patients (39.2 +/- 20 years vs. 63 +/- 13.3; p < 0.001), lower time between the admittance to ICU and the beginning of CHD (1.4 +/- 0.5 days vs. 3.5 +/- 2.6; p < 0.01) and lower APACHE II classification at admittance to ICU (7.4 +/- 1.6 vs. 19.0 +/- 2.7; p < 0.001) and at the start of CHD (13.6 +/- 3.2 vs. 24.7 +/- 3.7; p < 0.001). However, multivariate analysis revealed that the only variable associated with a better survival was a lower time between the admittance to intensive care and the beginning of CHD. DISCUSSION: CHD is a safe technique that can be used for acute renal failure patients who have contraindications for intermittent HD. This technique can be used in hospitals offering intermittent hemodialysis and intensive care. CHD use is associated with improvement of hemodynamic and metabolic alterations in patients with shock. Our data support the concept that the earlier the initiation of CHD the better the prognosis.

APACHE↗
PubMedDate not supplied

[Percutaneous kidney biopsy, analysis of 26 years: complication rate and risk factors; comment].

UNLABELLED: Percutaneous renal biopsy is an invasive procedure that can result in major and minor complications. The objective of this study was to know the frequency and type of complications in relation with this procedure, as well as the efficacy to obtain enough material for diagnosis. METHODS: Retrospective study. We review the charts of patients to whom a percutaneous renal biopsy of native kidneys was done between January 1970 and March 1996. The following data were obtained: age, gender, clinical and histopathological diagnosis, complications associated with the procedure (minor: hematuria, local infections, hematoma; major: transfusions, severe infections, surgery, nephrectomy, arteriography, embolism and death). RESULTS: We analyzed 1,005 renal biopsies in 840 patients, mean age 37.7 +/- 13.1 years, 67% female. There were no complications in 88.8% (893 biopsies), minor complications in 8.65% (87 biopsies) and only in 2.4% of the procedures major complications. We divided the cases in two groups: percutaneous renal biopsy without complications (n = 893, 89%) and with complications (n = 112, 11%). The most frequent complications were hematuria (91 cases, 9.1%) and perirenal hematoma (29 cases, 2.7%). In these cases transfusion was required in 2.4% (26). Infectious complications were: urosepsis in 7 cases (0.7%), bacteremia, sepsis and perirenal abscesses (1 case each, 0.1%). One patient died because of multiple complications (0.1%). We observed greater risk of major complications on patients in those who biopsy was done because of acute renal failure (OR 4.03, p < 0.003). DISCUSSION: In our experience percutaneous renal biopsy is a low risk procedure. Most complications are minor and without clinical repercussion. There must be a strict selection criteria of the patients to whom percutaneous renal biopsy is going to be done because of the risk of severe complications.

Abscess↗
PubMedDate not supplied

[Clinical course and prognostic factors in lupus nephropathy].

BACKGROUND: The present study was designed to know the clinical course of lupus nephritis and the risk factors associated with the development of end stage renal disease. METHODS: This a retrospective study performed in a cohort of 154 patients with biopsy proven lupus nephritis that were seen in our hospital between 1984 and 1990. The clinical records of all patients were reviewed in order to collect the following information at the time of the biopsy: age, sex, number and type of lupus criteria according with the American College of Reumathology, mean arterial pressure, serum creatinine, BUN, and albumin, as well as urinary protein excretion. The follow up was registered from the day the biopsy was performed to one of the following end points: end stage renal disease (defined as requirement of chronic dialysis), death or the end of study. All biopsies were analyzed by light microscopy to obtain the hystological subtype of lupus nephritis (WHO classification) and when type IV was diagnosed, the activity and chronicity indexes were also assessed. Kaplan-Meier survival tables were constructed. The association of clinical and laboratory variables with the development of end stage renal disease was obtained by log rank analysis. Variables obtained as significant were used to evaluate their individual impact using either the Cox multivariate proportional hazard method. RESULTS: Follow up was complete in 144 patients with a follow up time of 68 +/- 38 months. Ninety three patients were female with mean age of 28 +/- 9 years. At the time of the biopsy, renal manifestations had been present for 35 +/- 38 months and the number of lupus criteria per patient were 4 +/- 1. The clinical picture at the time of the biopsy was: nephrotic syndrome in 60%, non nephrotic proteinuria in 40%, and nephritic syndrome in only 2%. The hystological type of lupus nephritis was: I in 2%, II in 8%, III in 6%, IV in 71% and V in 11%. At the end of the study 28 patients developed end stage renal disease. For the whole group the survival of renal function was 85% at 70 months and 70% at 140 months. All, but one patient that developed end stage renal disease exhibited type IV nephropathy. In this subpopulation the mean activity and chronicity indexes were 8.5 +/- 3.5 and 3.1 +/- 2.4, respectively. By multivariate analysis the strongest predictors of end stage renal disease were the serum creatinine at the time of the biopsy, chronicity index, and age. The higher the serum creatinine and chronicity index at the time of biopsy, the higher the probability of developing end stage renal disease. CONCLUSIONS: We conclude that the clinical course of lupus nephritis in our population is similar to that seen in other series. The variables indicating advanced renal disease, such as high serum creatinine and chronicity index, were the strongest predictors of end stage renal disease.

Adult↗
PubMedDate not supplied

Quantification and characterization of protein loss in continuous ambulatory peritoneal dialysis.

BACKGROUND/AIMS: Dialysate protein loss is involved in the etiology of hypoalbuminemia and malnutrition on CAPD. There is no information regarding the peritoneal transport of proteins in neither Mexican nor LatinAmerican CAPD patients. Therefore, the aim of this study was to quantify and characterize the peritoneal membrane transport of albumin (Alb), IgG, IgA, and IgM in CAPD patients. In addition, factors associated to protein losses were investigated. METHODS: Thirty-seven CAPD patients were randomly selected and subjected to a standard peritoneal equilibration test (PET). Alb, IgG, IgA, and IgM were measured during the PET in both serum and dialysate. RESULTS: Dialysate IgM was not detected with the employed nephelometry method. A significant continuous and gradual increasing pattern in Alb, IgG and IgA losses was observed throughout the PET. During the PET, patients with the fastest transport type displayed the lowest serum concentration of Alb (but not Igs) and the greatest dialysate loss of all the assayed proteins. The strongest predictor for Alb, IgG, and IgA losses was peritoneal transport rate in both the univariate and multivariate analyses. CONCLUSIONS: Peritoneal Alb, IgG, and IgA losses in Mexican CAPD patients are mainly dependent on peritoneal transport rate and dialysate dwell-time.

Adult↗
PubMedDate not supplied

Long-term CAPD survival and analysis of mortality risk factors: 12-year experience of a single Mexican center.

OBJECTIVE: To evaluate patient and technique survival, and to analyze mortality risk factors in a large Mexican single-center continuous ambulatory peritoneal dialysis (CAPD) program. DESIGN: Cohort study. SETTING: Tertiary care, teaching hospital located in Mexico City. PATIENTS: All patients from our CAPD program (1985-1997) were retrospectively studied. INTERVENTIONS: Clinical and biochemical variables at the start of dialysis were recorded and considered in the analysis of risk factors. MAIN OUTCOME MEASURES: End points were patient (alive, dead, or lost to follow-up) and technique status at the end of the study (December 1997). RESULTS: 627 patients, 37% with diabetes mellitus (DM), were included. Median patient survival (+/- SE) was 5.1 +/- 0.6 years. In the univariate analysis, the following variables were associated (p < 0.05) with mortality: DM, old age, hypoalbuminemia, low serum creatinine, low serum phosphate, and lymphopenia. In the multivariate analysis, the only significant mortality risk factors were DM (RR 2.56, p < 0.0001), old age (RR 1.01, p = 0.01), hypoalbuminemia (RR 0.77, p = 0.04), and lymphopenia (RR 0.98, p = 0.05). Median technique survival was 4.0 +/- 0.2 years. Peritonitis, hypoalbuminemia, lymphopenia, old age, and DM were all significantly associated (p < 0.05) with technique failure in the univariate analysis, while in the multivariate analysis, only DM (RR 1.78, p = 0.001), peritonitis (RR 1.13, p = 0.004), lymphopenia (0.98, p = 0.04), and hypoalbuminemia (RR 0.80, p = 0.06) were technique failure predictors. CONCLUSIONS: Patient survival in our setting is similar to that reported in other series. Diabetes mellitus, lymphopenia, and hypoalbuminemia were the strongest predictive factors for mortality and technique failure on CAPD. Our 12-year CAPD program is one of the largest single-centers reported in CAPD literature.

Analysis of Variance↗