Periodontal treatment in patients with chronic kidney disease: a pilot study.

BACKGROUND AND OBJECTIVE: This pilot cohort study evaluated the effect of periodontal treatment on renal function, metabolic markers and asymmetric dimethylarginine (ADMA) in patients with pre-dialysis chronic kidney disease (CKD) presenting chronic periodontitis. MATERIAL AND METHODS: Twenty-six patients with CKD and severe chronic periodontitis were selected. Periodontal parameters included plaque index, bleeding on probing, probing pocket depth and clinical attachment level. Estimated glomerular filtration rate (eGFR), triglycerides, total cholesterol, albumin and ADMA levels were evaluated at baseline, 90 and 180 d after periodontal therapy. eGFR was evaluated by the Modification of Diet in Renal Disease equation. RESULTS: All periodontal clinical parameters significantly improved (p < 0.05) 180 d after periodontal therapy. There was a significant improvement on the median values (25%; 75% percentiles) of eGFR from 34.6 (27; 44.7) mL/min/1.73 m2 on baseline to 37.6 (29.7; 57) mL/min/1.73 m2 on day 90, and to 37.6 (28.6; 56) mL/min/1.73 m2 (p < 0.05) on day 180. ADMA levels significantly reduced 180 d after periodontal treatment. No significant differences were observed at the median values of metabolic markers comparing baseline and 180 d after periodontal treatment. CONCLUSIONS: The results point to a link of kidney disease with endothelium dysfunction and periodontitis, suggesting that periodontal treatment may be beneficial to the course of CKD.

Extent and severity of chronic periodontitis in chronic kidney disease patients.

UNLABELLED: BACKGROUND AND OBJECTVE: Chronic inflammatory diseases have been investigated as a possible source of inflammation in chronic kidney disease patients; however, there is a shortage of information about the prevalence of periodontitis in such individuals. Therefore, the aim of this cross-sectional study was to determine the extent and severity of periodontitis in chronic kidney disease patients undergoing the following three different treatment modalities: predialysis; continuous ambulatory peritoneal dialysis (CAPD); and hemodialysis (HD); and to compare the findings with those from systemically healthy individuals. MATERIAL AND METHODS: Forty CAPD patients (mean age 52±12 years), 40 HD patients (mean age 50±10 years), 51 predialysis patients (mean age 54±11 years) and 67 healthy individuals (mean age 50±7 years) were examined. The periodontal examination included probing pocket depth, clinical attachment loss, bleeding on probing and presence of plaque. Patients with at least four sites with clinical attachment loss ≥6 mm were considered to have severe chronic periodontitis, and those with at least 30% of sites with clinical attachment loss ≥4 mm were considered to have generalized chronic periodontitis. RESULTS: Predialysis and HD patients had significantly more sites with clinical attachment loss ≥6 mm than healthy individuals. The CAPD patients had similar periodontal condition to healthy subjects. There were significantly more cases of severe chronic periodontitis in predialysis and HD patients. CONCLUSION: Predialysis and HD are associated with a higher prevalence of severe periodontitis compared with healthy individuals and CAPD patients.

Effects of systemic hypertension, antidiuretic hormone, and prostaglandins on remnant nephrons.

Renal function was evaluated in normal and after 30 days of 5/6 renal mass reduction (CRF) in Munich-Wistar (MW) rats, spontaneously hypertensive rats with superficial glomeruli (EPM), and in Brattleboro rats with congenital diabetes insipidus (DI). Mean arterial pressure was higher in EPM-Control and EPM-CRF rats as compared with MW and DI rats. MW and EPM rats with CRF showed increases of 120% and 196%, respectively, in single nephron glomerular filtration rate as compared with their controls. However, DI rats with CRF did not show any increase in single nephron glomerular filtration rate as compared with the control group. Therefore, the data suggest that the presence of hypertension enhances the adaptive mechanisms on remnant kidney's function. Conversely, in the absence of antidiuretic hormone, adaptive mechanisms of remnant nephrons did not occur. In addition, it was observed that rats with CRF submitted to prostaglandin blockade with indomethacin showed for MW rats a 55% and 20% reduction in ultrafiltration coefficient and in single nephron glomerular filtration rate, respectively. Decreases of 60% and 30% in ultrafiltration coefficient and single nephron glomerular filtration rate, respectively, were observed for EPM rats. In contrast, DI rats did not show any alteration on renal function after indomethacin. It seems, therefore, that prostaglandins play a role in remnant nephron function of MW and EPM rats, but in the absence of antidiuretic hormone, prostaglandins do not affect remnant glomerular hemodynamics.

Effect of platelet-activating factor antagonist on cyclosporine nephrotoxicity. Glomerular hemodynamics evaluation.

In order to evaluate the effect of platelet-activating factor (PAF) antagonist BN 52021 (5 mg/kg i.v.) on cyclosporine (50 mg/kg i.v.) nephrotoxicity, euvolemic Munich-Wistar rats were submitted to micropuncture studies. BN 52021 alone did not change the total (1.08 +/- 0.07 vs. 1.04 +/- 0.06 ml/min) or single nephron (SN) (29.1 +/- 50 vs. 31.3 +/- 4.0 nl/min) and glomerular filtration rate. The CsA administration caused a decline on GFR (0.47 +/- 0.07 vs. 0.96 +/- 0.04 ml/min, P less than 0.05) and on SNGFR (14.0 +/- 3.5 vs. 27.9 +/- 3.4 ml/min, P less than 0.05). An increase in afferent (RA) and efferent (RE) arteriolar resistances, 180% and 360%, respectively, that caused a decrease on glomerular plasma flow rate (QA) from 100.99 +/- 17.09 to 44.37 +/- 13.37 nl/min (P less than 0.05) was observed. Moreover, the glomerular ultrafiltration coefficient (Kf) declined by 70% (0.096 +/- 0.003 to 0.031 +/- 0.10 ml/sec mmHg, P less than 0.05). The previous BN 52021 administration on rats treated with CsA blunted its effects on superficial nephrons. The SNGFR (22.3 +/- 3.0 vs. 28.0 +/- 25 nl/min), QA (72.2 +/- 5.9 vs. 91.7 +/- 12.1 nl/min) and KF (0.038 +/- 0.009 vs. 0.048 +/- 0.005 nl/s mmHg) remained unaltered. By contrast, the total renal function was not prevented by BN 52021 treatment: GFR 0.45 +/- 0.12 vs. 0.94 +/- 0.05 ml/min (P less than 0.05). Thus, this study suggests that PAF may participate in CsA nephrotoxicity. Furthermore, the protective effect of BN 52021 on superficial nephrons may indicate that BN 52021 is a drug that can minimize the impairment of renal function induced by CsA.

Effect of unilateral nephrectomy on renal function of diabetic rats.

Glomerular alterations of experimental diabetes mellitus are observed in animals submitted to a reduction in renal mass, suggesting that some mechanisms responsible for the progression of renal disease are common. The aim of this study was to investigate the effect of nephrectomy on the renal function and morphology of diabetic rats. Male Wistar rats were divided into 4 groups: control (C), n=8; diabetic (DM), n=8; non-diabetic nephrectomized (Nx), n=8; (DMNx), n=9. DM was induced by streptozotocin (65 mg/Kg), and animals were treated with insulin. After 12 weeks, the glomerular filtration rate (GFR), renal plasma flow (RPF) and mean arterial pressure (MAP) were evaluated in unanaesthetized animals. Glomerular volume (GV), glomerular sclerosis index (GSI), mesangial volume density (Vvmes) and glomerular capillary surface density (Svcap) were also evaluated. Results show that kidney weight increased in Nx groups, being higher in DMNx. GFR was higher in Nx groups as was RPF, being higher in DMNx. RVR was lower in Nx groups, especially in DMNx. MAP was not different among the groups. RPF and GFR showed a high correlation for the DMNx group (r=0.95, p=0.02). The DMNx group showed a correlation between RVR and GFR (r=-0.96, p=0.005). The GV increased in Nx groups, and the GSI was higher in DMNx. Vvmes and Svcap increased in DMNx group. In summary, Nx groups developed similar degrees of glomerular hypertrophy, but only DMNx showed an increased value for GSI. The present data suggest that the acceleration of glomerular lesions in DMNx animals was more closely associated to hemodynamic adaptations than to glomerular hypertrophy.

Effect of time on remnant glomerular function.

1. Although hypertrophy and hyperfiltration have been identified in remnant nephrons, the time of their appearance and the relationship between them have not been established. In order to evaluate remnant glomerular hemodynamics over different periods of time, we studied Munich-Wistar rats 7, 30 and 60 days after 5/6 renal mass ablation. 2. Kidney weight increased after 7 days, continued to increase after 30 days and decreased after 60 days. Glomerular filtration rate (GFR) and renal plasma flow decreased by 67% and 7 days, were 35% lower than normal after 30 days, and after 60 days presented the same values as after 7 days. Single-nephron GFR and glomerular plasma flow increased slightly after 7 days, were 118% higher than control after 30 days, and decreased after 60 days. Hydraulic glomerular capillary pressure tended to increase after 30 days (6%), reaching statistical significance after 60 days (45 vs 62 mmHg). The glomerular ultrafiltration coefficient increased significantly after 30 days (82%) and decreased to values similar to the control group after 60 days. 3. These data suggest that kidney hypertrophy occurs early after reduction of renal mass, before the hemodynamic adaptations are complete. Glomerular hypertension was observed after 60 days, when single-nephron GFR and the glomerular ultrafiltration coefficient were decreased compared to rats studied after 30 days. 4. These data may indicate that, once glomerular hypertension starts, structural abnormalities are followed by a decline in glomerular function.

Effect of dietary linoleic acid on the progression of chronic renal failure in rats.

The role of linoleic acid in chronic renal failure (CRF) is controversial. In the present study 21 male Wistar rats submitted to 5/6 renal mass reduction (R) and 16 normal controls (C) were fed a supplement (S) or normal (N) linoleic acid diet for 60 days starting 10 days after CRF. As expected, serum creatinine, cholesterol and triglycerides (mean +/- SEM) were higher in the CRF groups compared to the C groups (P<0.05). The RS group presented lower cholesterol (84 +/- 4 vs 126 +/- 13 mg%) and triglyceride (88 +/- 9 vs 132 +/- 19 mg%) levels compared to the RN group. Proteinuria and kidney weight did not differ between CRF groups. Glomerular area increased 78% in RS and 100% in RN compared to control rats. Glomerular sclerosis index tended to be lower in RS (27%) compared to RN (38%), tubulointerstitial damage was similar between CRF groups (RS = 1.91 +/- 0.2 and RN = 2.14 +/- 0.3), and mesangial fractional volume increased to the same extent in both CRF groups. The data suggest that a linoleic acid-enriched diet did not protect against the progression of CRF after 60 days.

Effect of cicletanine on the progression of chronic renal failure in rats.

1. The effects of chronically administered cicletanine (CICL), an antihypertensive and prostacyclin stimulating agent, on glomerular hemodynamics were evaluated after 30 (CRF-30) or 60 (CRF-60) days of chronic renal failure (CRF) induced by 5/6 nephrectomy in Munich-Wistar rats. 2. CICL administration (3 mg kg-1 day-1, N = 5) for 60 days did not modify glomerular hemodynamics of normal rats (control group). The CRF-60 group (N = 6) presented a significant increase in mean arterial pressure (MAP) compared with control (122 +/- 7 vs 98 +/- 2 mmHg, P < 0.05), which was attenuated by CICL (113 +/- 7 vs 122 +/- 7 mmHg). 3. Hyperfiltration and hyperperfusion were observed in both CRF groups after 30 (N = 5) but not after 60 days of CRF, 73.9 +/- 6.3 and 48.2 +/- 3.2 vs 36.8 +/- 2.6 nl/min for SNGFR and 200 +/- 17 and 147 +/- 8 vs 112 +/- 8 nl/min for QA in CRF-30, CRF-60 vs control group, respectively. However, glomerular hypertension was demonstrable for both CRF groups only after 60 days. CICL treatment starting 7 days prior to nephrectomy reduced the transcapillary hydraulic pressure difference (delta P) in both groups, 36 +/- 3 vs 30 +/- 2 mmHg (30 days) and 41 +/- 4 vs 34 +/- 2 (60 days), but did not significantly modify arteriolar resistances or glomerular hemodynamics, suggesting that the reduction in MAP in response to CICL may have been responsible for the decrease in delta P. CICL administration did not prevent the proteinuria or glomerular sclerosis associated with CRF. 4. The results suggest that the administration of CICL for 30 (N = 4) to 60 days (N = 7) was sufficient to prevent systemic hypertension associated with CRF but not to reduce the additional glomerular hemodynamic factors that participate in the progression of CRF.

Effect of castration on renal glycosaminoglycans and their urinary excretion in male and female rats with chronic renal failure.

Glycosaminoglycans (GAGs) participate in a variety of processes in the kidney, and evidence suggests that gender-related hormones participate in renal function. The aim of this study was to analyze the relationship of GAGs, gender, and proteinuria in male and female rats with chronic renal failure (CRF). GAGs were analyzed in total kidney tissue and 24-h urine of castrated (c), male (M), and female (F) Wistar control (C) rats (CM, CMc, CF, CFc) and after 30 days of CRF induced by 5/6 nephrectomy (CRFM, CRFMc, CRFF, CRFFc). Total GAG quantification and composition were determined using agarose and polyacrylamide gel electrophoresis, respectively. Renal GAGs were higher in CF compared to CM. CRFM presented an increase in renal GAGs, heparan sulfate (HS), and proteinuria, while castration reduced these parameters. However, CRFF and CRFFc groups showed a decrease in renal GAGs concomitant with an increase in proteinuria. Our results suggest that, in CRFM, sex hormones quantitatively alter GAGs, mainly HS, and possibly the glomerular filtration barrier, leading to proteinuria. The lack of this response in CRFMc, where HS did not increase, corroborates this theory. This pattern was not observed in females. Further studies of CRF are needed to clarify gender-dependent differences in HS synthesis.

Effect of castration on renal glycosaminoglycans and their urinary excretion in male and female rats with chronic renal failure

Glycosaminoglycans (GAGs) participate in a variety of processes in the kidney, and evidence suggests that gender-related hormones participate in renal function. The aim of this study was to analyze the relationship of GAGs, gender, and proteinuria in male and female rats with chronic renal failure (CRF). GAGs were analyzed in total kidney tissue and 24-h urine of castrated (c), male (M), and female (F) Wistar control (C) rats (CM, CMc, CF, CFc) and after 30 days of CRF induced by 5/6 nephrectomy (CRFM, CRFMc, CRFF, CRFFc). Total GAG quantification and composition were determined using agarose and polyacrylamide gel electrophoresis, respectively. Renal GAGs were higher in CF compared to CM. CRFM presented an increase in renal GAGs, heparan sulfate (HS), and proteinuria, while castration reduced these parameters. However, CRFF and CRFFc groups showed a decrease in renal GAGs concomitant with an increase in proteinuria. Our results suggest that, in CRFM, sex hormones quantitatively alter GAGs, mainly HS, and possibly the glomerular filtration barrier, leading to proteinuria. The lack of this response in CRFMc, where HS did not increase, corroborates this theory. This pattern was not observed in females. Further studies of CRF are needed to clarify gender-dependent differences in HS synthesis.

Periodicity in growth, productivity, nutrient content and decomposition ofSphagnum recurvum var.mucronatum in a fen woodland.

Condition in the understory of aBetula-carr appeared to be favourable for the growth ofSphagnum recurvum. The estimates of annual productivity and nutrient accumulations forS. recurvum obtained in this wetland forest are in the high range of those reported for peatmosses. On an annual basis, the organic matter production, vegetative reproduction (forking), and accumulation of N, P and K were very much the same for a relatively dry and for a relatively wet year. Periodicity in growth and length increase of the plants, however, differed remarkably between these years, and fruiting was observed in the dry year only.S. recurvum was characterized by a distinct variation in nutrient concentrations both with time and with distance from the capitulum. Organic weight loss during breakdown ofS. recurvum in the wetland forest was low. Release of N, P and particularly K was larger than that of organic matter in decomposingS. recurvum. Nevertheless, a relatively large proportion of the original N and P stock remained associated with the peatmoss material after a 12 month decay period. Observations with the scanning electron microscope revealed that after a year the cells of deadS. recurvum were hardly damaged and only poorly colonized by microorganisms. The characteristics ofS. recurvum described here indicate its potency in directing succession in peatland forests.

Ultrasonic recognition of parenchymal gas.

Abdominal sonography in six febrile patients was suspicious for parenchymal gas. In five, immediate radiographic confirmation was obtained. Four patients had gas-containing abscesses, one had gas sequestered in a hepatic hematoma, and in the other subcapsular hepatic gas probably originated by mesenteric dissection from pneumatosis cystoides intestinals.

Effect of dietary linoleic acid on the progression of chronic renal failure in rats

The role of linoleic acid in chronic renal failure (CRF) is controversial. In the present study 21 male Wistar rats submitted to 5/6 renal mass reduction (R) and 16 normal controls (C) were fed a supplement (S) or normal (N) linoleic acid diet for 60 days starting 10 days after CRF. As expected, serum creatinine, cholesterol and triglycerides (mean SEM) were higher in the CRF groups compared to the C groups (P<0.05). The RS group presented lower cholesterol (84 4 vs 126 13 mg percent) and triglyceride (88 9 vs 132 19 mg percent) levels compared to the RN group. Proteinuria and kidney weight did not differ between CRF groups. Glomerular area increased 78 percent in RS and 100 percent in RN compared to control rats. Glomerular sclerosis index tended to be lower in RS (27 percent) compared to RN (38 percent), tubulointerstitial damage was similar between CRF groups (RS = 1.91 0.2 and RN = 2.14 0.3), and mesangial fractional volume increased to the same extent in both CRF groups. The data suggest that a linoleic acid-enriched diet did not protect against the progression of CRF after 60 days

Alguns fatores na progressäo da doença renal / Some factors in evolution of chronic renal failure

Adaptaçöes estruturais e funcionais foram demonstradas em néfrons remanescentes após lesäo renal. O grau destas adaptaçöes correlaciona-se diretamente com a quantidade de parênquima renal perdido. No entanto, várias observaçöes sugerem que a evoluçäo para insuficiência renal crônica (IRC), após esta perda de massa renal funcionante, é progressiva. Porém, os fatores responsáveis por esta evoluçäo ainda näo estäo estabelecidos. A hipertensäo e o hiperfluxo glomerulares que ocorrem nos néfrons remanescentes, especialmente em pacientes ou animais alimentados com dieta hiperprotéica, foram identificados como fatores que aceleram esta evoluçäo. Sabe-se também que as prostaglandinas (PGs) vasodilatadoras encontram-se elevadas na urina de humanos e animais de experimentaçäo com IRC, e que participam da manutençäo da filtraçäo glomerular. Alguns estudos recentes têm sugerido que estas PGs exercem um papel fundamental na manutençäo da vasodilataçäo renal que ocorre nos néfrons remanescentes. Sugere-se que as PGs teriam um papel fundamental na evoluçäo da IRC paralelamente com a dieta hiperprotéica. Finalmente, mecanismos hemodinâmicos da progressäo da IRC säo sugeridos e possivelmente novos enfoques terapêuticos conservadores (näo dialíticos) deveräo ser indicados