Biomedical subjects

David Dorigo

Publications and source records attributed to David Dorigo.

7 recordsLinked to original sources

PubMed2005

Bone disease in patients with chronic kidney disease under conservative management.

CONTEXT AND OBJECTIVE: Few studies have focused on bone disease in patients with chronic kidney disease under conservative treatment. The objective was to evaluate bone disease in patients with chronic kidney disease. DESIGN AND SETTING: Case series, at the Nephrology Division, Hospital Universitário Pedro Ernesto. METHODS: 131 patients with creatinine clearance from 10 to 60 ml/min/1.73 m(2) were followed up for at least one year. Serum creatinine, albumin, calcium, phosphorus, alkaline phosphatase, total CO2 (tCO2), intact parathyroid hormone (iPTH), and alkaline phosphatase were measured. Creatinine clearance was calculated from 24-hour urine creatinine measurements and protein ingestion estimates from urea assays. RESULTS: Patients presenting creatinine clearance < 30 ml/min/1.73 m(2) had higher iPTH values, but normal serum levels for calcium, phosphorus, alkaline phosphatase and tCO2. Patients presenting iPTH values of twice the normal upper limit (144 pg/ml) showed lower tCO2 values. Bone alkaline phosphatase was evaluated in 37 patients with creatinine clearance < 30 ml/min/1.73 m(2), showing correlation with alkaline phosphatase but not with parathyroid hormone. Bone biopsy on nine patients with creatinine clearance < 30 ml/min/1.73 m(2) and iPTH > 144 pg/ml showed osteitis fibrosa (4), mild lesion (4) and high turnover (1). CONCLUSION: The present data suggest the importance of early control for iPTH and metabolic acidosis, among patients under conservative management for chronic kidney disease, in order to prevent complications related to bone disease.

Absorptiometry, Photon↗

PubMed2004

Clinical consequences of an individualized dialysate sodium prescription in hemodialysis patients.

BACKGROUND: Predialysis plasma sodium (Na(+)) concentration is relatively constant in hemodialysis (HD) patients, and a higher dialysate Na(+) concentration can promote an increase in the interdialytic fluid ingestion to achieve an individual's osmolar set point, and individualization of dialysate Na(+) concentration may improve interdialytic weight gain (IDWG), blood pressure (BP), and HD-related symptoms. METHODS: Twenty-seven nondiabetic, non-hypotension prone HD patients were enrolled in a single-blind crossover study. Subjects underwent nine consecutive HD sessions with the dialysate Na(+) concentration set to 138 mEq/L (standard Na(+) HD), followed by nine sessions wherein the dialysate Na(+) was set to match the patients average pre-HD plasma Na(+) measured three times during the standard Na(+) phase multiplied by 0.95 (individualized dialysate Na(+) HD). Dry weight, dialysis prescription, and medications were not modified during the six weeks of the study. RESULTS: Pre-HD Na(+) was similar in both periods of the study (standard Na(+) HD, 134.0 +/- 1.4 mEq/L; individualized Na(+) HD, 134.0 +/- 1.5 mEq/L; P= 0.735). There was a significant decrease in interdialytic weight gain (2.91 +/- 0.87 kg vs. 2.29 +/- 0.65 kg; P< 0.001), interdialytic thirst scores, and episodes of intradialytic hypotension in the individualized Na(+) period compared with the standard phase. Pre-HD BP was lower in individualized Na(+) HD in patients with uncontrolled BP at baseline (N= 15), but not in those with controlled BP at baseline (N= 12) (DeltaBP -15.6/-6.5 mm Hg in uncontrolled vs. DeltaBP +6.4/+4.5 mm Hg in controlled, P= <0.001 for systolic BP and P= <0.001 for diastolic BP). CONCLUSION: An individualized Na(+) dialysate based on predialysis plasma Na(+) levels decreases thirst, IDWG, HD-related symptoms, and pre-HD BP (in patients with uncontrolled BP at baseline).

Adult↗

PubMed2003

The use of peridialysis blood pressure and intradialytic blood pressure changes in the prediction of interdialytic blood pressure in haemodialysis patients.

OBJECTIVE: It is uncertain which blood pressure values (pre- or post-haemodialysis) best represent the average daily blood pressure in haemodialysis patients. The purpose of this study was to verify the power of peridialysis blood pressure to predict interdialytic blood pressure, and to ascertain the influence of blood pressure fluctuations during dialysis on this predictive ability. METHODS AND RESULTS: We performed ambulatory blood pressure monitoring during the interdialytic period on 60 stable haemodialysis patients (mean age 53 +/- 16 years, 33 male) between two mid-week haemodialysis sessions. Pre- and post-haemodialysis blood pressures were 154/82 and 142/77 mmHg, respectively, and 44-h interdialytic blood pressure was 136/77 mmHg. Overall, post-haemodialysis blood pressure values correlated with interdialytic ambulatory blood pressure marginally better than did pre-haemodialysis values (r = 0.52 versus 0.61 for pre- and post-dialysis systolic pressure, respectively; r = 0.67 versus 0.72 for pre- and post-dialysis diastolic pressure, respectively). The average of the pre- and post-haemodialysis values showed a slightly better correlation with interdialytic blood pressure (r = 0.65 and 0.75 for systolic and diastolic pressure, respectively). When we stratified patients according to systolic blood pressure behaviour during dialysis, pre-dialysis blood pressure was the stronger predictor of interdialytic blood pressure in the quartile with greatest intradialytic blood pressure fall (r = 0.67 versus 0.44 for pre- and post-dialysis systolic blood pressure, respectively), whereas post-dialysis values were substantially better in the group with a rise in systolic pressure during dialysis (r = 0.26 versus 0.59 for pre- and post-dialysis systolic blood pressure, respectively). CONCLUSIONS: These data demonstrate that peridialysis blood pressure values are of limited accuracy in predicting interdialytic blood pressure, post-dialysis values are minimally better predictors than pre-dialysis blood pressures, and the average of pre- and post-haemodialysis values is marginally better than both. In addition, blood pressure fluctuations during dialysis have a sizable impact on this predictive ability. Clinical decisions related to blood pressure management and research design in haemodialysis hypertension should take these factors into account.

Blood Pressure↗

PubMedDate not supplied

Profile of interdialytic blood pressure in hemodialysis patients.

BACKGROUND AND METHODS: Hypertension is a common problem in hemodialysis (HD). However, its behavior during the interdialytic period is not completely known and is infrequently monitored in clinical practice. Thus, for better understanding of interdialytic blood pressure (BP), we analyzed the interdialytic blood pressure profile using 44-hour ambulatory blood pressure monitoring (ABPM) data in 71 unselected, stable HD patients. RESULTS: There was an increase in BP during the interdialytic period (awake day 1: 135/84 +/- 23/14 mm Hg; awake day 2: 140/86 +/- 22/15 mm Hg, p < 0.05; sleep day 1: 130/77 +/- 24/15 mm Hg; sleep day 2: 136/80 +/- 24/15 mm Hg, p < 0.05). The correlation between the average 44-hour BP and interdialytic weight gain (IDWG) was not significant (r = -0.07 for systolic BP and r = -0.09 for diastolic BP). The number of non-dipper patients was high, 77% on interdialytic day 1 and 83% on interdialytic day 2 for systolic BP. Uncontrolled hypertension (average 44 h BP > or =135/85 mm Hg) was diagnosed in 58 (55%) patients. Patients with uncontrolled hypertension had higher pre- and posthemodialysis BP, higher BP on each interdialytic day and night, and higher night/day diastolic BP ratio on the second interdialytic day. These patients were also taking a greater number of vasoactive medications (1.5 vs. 0.6 in those with controlled BP, p = 0.001). There were no significant differences related to kt/V, hematocrit, or weekly erythropoietin dose between patients with controlled or uncontrolled BP. Hemodialysis shift assignment (morning or afternoon) did not impact on BP levels or diurnal profile. CONCLUSION: In HD patients, interdialytic BP is often poorly controlled, there is a progressive rise in BP, and a trend toward loss of nocturnal decline in BP as the interdialytic period progresses. Further research is needed to determine whether treatment directed to interdialytic BP changes can alter outcomes in HD patients.

Antihypertensive Agents↗

PubMedDate not supplied

Nailfold videocapillaroscopy in primary Sjögren's syndrome.

Nailfold videocapillaroscopy was performed in 2 groups of subjects: 14 healthy volunteers (C) and 15 patients with primary Sjögren's syndrome (PSS). This was a controlled clinical trial, matched by age and sex. The aims of this study were to evaluate (1) functional capillary density (number of capillaries with flowing red blood cells per mm(2), FCD); (2) capillary red blood cell velocity at rest (RBV), maximum capillary red blood cell velocity (RBV(max)) after 1 minute ischemia, and the time to reach it (TRBV(max)), taking into account the presence or absence of Raynaud's phenomenon (RP) in the analysis; (3) nailfold capillary morphology; and (4) afferent (AFD), apical (APD), and efferent (EFD) capillary diameters. The mean values obtained for controls versus patients, respectively, were (mean +/- SD): FCD (per mm(2)) 8.0 +/-1.6 and 10.1 +/-3.6; RBV (mm/s) 0.9 +/-0.4 and 0.7 +/-0.2; RBV(max) (mm/s) 1.7 +/-0.9 and 1.3 +/-0.3; TRBV(max) (s) 4.5 +/-0.8 and 5.8 +/-1.6 (p=0.02); and TRBV(max) (s) in patients with RP=6.7 +/-1.6 and without RP=5.6 +/-1.6 (p=0.52). The correlation between RBV and RBV(max) for each group, using the Pearson's coefficient, was significant only for the control group (p=0.007), estimated correlation coefficient = 0.68. Controls and patients showed, in the majority of fields examined, normal morphologic patterns of capillaries. The capillary diameters were AFD (mum) 10.8 +/-1.5 and 11.3 +/-1.8; APD (mum) 16.3 +/-2.4 and 16.8 +/-2.9; and EFD (mum) 12.3 +/-1.4 and 13.7 +/-1.9. These results indicate that these patients have longer time to reach RBV(max), suggesting an impairment of the reactive hyperemia response, which could correlate with clinical features of the disease, ie, abnormal macrovascular and microvascular reactivity.

Adult↗

PubMedDate not supplied

Normal renal dimensions in a specific population.

INTRODUCTION: Renal dimensions (RD) are important for the diagnostic and the prognostic of nephropathies. MATERIALS AND METHODS: We selected 904 Brazilians subjects with normal excretory urographies, showing dense nephrogram at the 5th minute of the exam, serum creatinine < 1.3mg/dl, and absence of any disease that could modify RD. Length, width, and area of both kidneys were correlated with gender, age, height, and body weight. Five hundred and eighty one subjects were men (64.3%) and 323 were women (35.7%). Age ranged from 21 to 87 years old, body weight from 40 to 106kg (69.9+/-9.5 for men and 62.4+/-9.7 for women), and height from 1.37 to 1.94m (1.68+/-0.07 for men and 1.57+/-0.07 for women). RESULTS: There was an association (one-way Anova test) between length, width, and area, for each kidney and for both, with height (p<0.001), body weight (p<0.001), and gender (p<0.001). After adjustment for height (covariance analysis), both gender and body weight did not show influence on RD. Renal length and area reduced with aging (p<0.001), from the 7th decade compared to the others. Excluding these patients, height was the only variable to show association with RD, justifying data stratification by this variable. CONCLUSIONS: Renal length in this population showed that the normal patterns defined by other studies are inadequate for our population. Adjusting the data by height, gender, and body weight did not influence RD; however, the left kidney was bigger than the right kidney. Also, the influence of height was more pronounced below 1.66m.

Journal Article↗

PubMedDate not supplied

Chronic renal failure in male and female rats.

Gender influences the progression of chronic renal failure (CRF). We studied male (M) and female (F) Wistar rats for 90 days: castrated (CMc,n=7;CFc,n=6) and non castrated controls (CM,n=9;CF,n=6); castrated (CRFMc,n=8; CRFFc,n=6) and non castrated animals submitted to 5/6 nephrectomy (CRFM,n=13;CRFF,n=6). Data are expressed as mean +/-SEM. Proteinuria (PTN) was higher in CRFM (554+/-69 mg/24h) compared to CRFMc (277+/-85 mg/24h), but not in females (CRFF=193+/-20mg/24h, CRFFc= 164+/-71 mg/24h). Mesangial fractional volume increased in all CRF animals. CRF animals showed an increase of glomerular sclerosis index (GSI) and tubulointerstitial damage (TID) but in a smaller proportion in male castrated animals; the opposite occurred with females: castration induced an increase of these parameters. CRF animals showed increased cortical and glomerular fibronectin (FN) rates. Castration decreased glomerular and cortical FN rates in CRFM but not in females. In conclusion, proteinuria was higher in CRFM and probably led to glomerular and interstitial damage, as well as to FN accumulation, castration seems to protect against development of PTN, TID and FN accumulation in males. Castrated female rats presented mesangial expansion, with no changes in PTN, TID and FN rates. It seems that female sex hormones do not protect against renal disease progression, instead, we suggest that male sex hormones lead to acceleration of CRF.

Animals↗