摘要:

The heat shock (HS) response is remarkably conserved during evolution and is evoked under many conditions of stress. There are a number of ways in which this ubiquitous response may be important for the understanding of renal pathophysiology. Ischemia, toxin exposure, and oxidative stress induce this response. Several models of hypertension are associated with increased susceptibility to environmental stress and increased accumulation of heat shock protein mRNA. HSP70 polymorphism has been demonstrated when comparing normotensive and hypertensive rats. Heat shock proteins may play a role in renal diseases through their important involvement in immunologi-cal processes. Several observations point to a role of the heat shock response in systemic lupus erythematosus (SLE). Autoantibodies against HSP70 and ubiquitin are found in many patients with this disease. Autoantibodies against ubiquitin and ubiquitinated histone H2A are localized to the kidney glomer-ular basement membrane of SLE patients with active disease. A better understanding of the HS response may thus provide important insight into renal pathophysiology and may suggest paradigms for therapeutic interventions.

ISSN:0886-022X    

DOI:10.3109/08860229409044859

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

The present study was performed in vivo in rabbits to evaluate the functional and morphologic effects of verapamil in a model of ischemic acute renal failure (ARF). Particularly impressive was the ultrastructural integrity of renal tubules in the animals exposed to both ischemia and verapamil. Three groups were studied: Group A: no ischemia; Group B: renal ischemia alone; and Group C: renal ischemia with verapamil. Creatinine clearance was higher in Group C (0.77 mL/min/kg) compared to Group B (0.13 mL/min/kg) at 24 h of reperfusion (p<. 005) as well as at 48 and 72 h (0.73 mL/min/kg vs. 0.35 mL/min/kg; p<. 05 and 0.90 mL/min/kg vs. 0.46 mL/min/kg; p<0.05, respectively). Light microscopic evaluation of Group C rabbits revealed significantly better preservation of proximal tubule (PT) brush border (p<. 0005) and less desquamation of PT (p<. 05) compared to Group B. Ultrastructural examination of in vivo perfused kidneys also demonstrated decreased loss of microvilli of PT (p<. 0005) as well as less cellular edema (p<. 005), fewer cells with apical PT membrane rupture (p<. 01), better preservation of mitochondria (p<. 005), less flattening of the PT basolateral labyrinth (p<. 05), and fewer hypertrophic actin bands at the basal surface of PT epithelial cells (p<. 05). These results suggest that verapamil markedly attenuates PT morphologic injury in a rabbit model of reversible ischemic ARF. The functional protection observed in these studies may be related, in part, to the improved structural integrity of the renal tubules. Renal transplantation and anticipated renal ischemia (i.e., surgical interventions) are two important situations where treatment with verapamil or other calcium channel blockers may prove to be clinically beneficial.

ISSN:0886-022X    

DOI:10.3109/08860229409044860

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

We evaluated amount and composition of amino acids in supplementation of hyperalimentation from the standpoint of whether it may improve nutrition and/or reduce the indexes of uremia such as BUN. Rats with established uremia, by5/6nephrectomy, were treated with various isocaloric solutions containing different amount of essential amino acids and histidine (EAA) or standard amino acids (SAA) which were formulated to provide Cal/N ratios of 300, 600, and 900. The BUN was lower and the nutritional index was better in rats infused with EAA compared with those administrated SAA, while severe distortion of plasma amino acid concentration, hyperammonemia, and fatty liver were observed at the Cal/N 300 condition. Rats infused with SAA gained positive nitrogen balance at the condition of Cal/N 300′, however, plasma amino acid distortion was still observed. These results indicate that administration of EAA alone for treatment of renal failure needs high-calorie and low-nitrogen conditions such as Cal/N 600 for avoiding complications. Administration of standard amino acid solution is safe and nutritionally effective in the Cal/N 300 condition, but there are a few problems concerning nitrogen availability and plasma amino acid pattern.

ISSN:0886-022X    

DOI:10.3109/08860229409044861

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

The effects of 3 consecutive days of oral chloroquine (1 mg/100 g body weight) on kidney function and blood pressure were studied in male Sprague—Dawley rats that were challenged with hypotonic saline infusion 24 h after the last chloroquine administration. The rats were anesthetized with Inactin [5 ethyl-5-(1′-methylpropyl)-2-thiobarbiturate, Byk Gulden] and continuously infused with 0.077 M NaCl for 8 h; urine flow and electrolyte excretion rates were monitored during the last 5 h. Blood pressure and glomerular filtration rates were also measured. Kidney function was compromised in chloroquine-treated rats, which retained significantly more of the infused Na+and Cl−by comparison to control-vehicle-treated rats. Throughout the experimental period, chloroquine-treated rats exhibited low blood pressure (80 mm Hg vs. 127 mm Hg) which was associated with low glomerular filtration rate. The plasma aldosterone concentrations were significantly (p<0.01) elevated in rats pretreated with chloroquine at the end of the 8-h infusion of hypotonic saline, but corticosterone levels were significantly (p<0.01) lower in the treated rats. It is concluded that chloroquine administration impairs kidney function, resulting in inappropriate Na+and Cl−retention. This effect is likely to be mediated via chloroquine-induced increases in plasma aldoster-one concentration and lowering of GFR.

ISSN:0886-022X    

DOI:10.3109/08860229409044862

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

To evaluate the role ofrenin-angiotensin in the renal vasoconstriction with combined acute hypoxemia and hypercapnic acidosis preceded by acute hypoxemia, we studied eight conscious mongrel uninephrectomized dogs with chronic renal catheters and controlled sodium intake (80 mEq/24 h±4 days). The animals were studied during combined acute hypoxemia and hypercapnic acidosis (PaO234±1 mm Hg, PaCO257±1 mm Hg, pH 7.20±0.01) preceded by 80 min of acute hypoxemia (PaO234±1 mm Hg) during: (a) intrarenal infusion of vehicle (n = 8); or (b) intrarenal administration of the angiotensin II antagonist [Sar1, Ala8]-AII, 70 ng kg−1min−1(n = 8). The combination of acute hypoxemia and hypercapnic acidosis resulted in diminished effective renal plasma flow and increased renal vascular resistance during intrarenal vehicle infusion. Intrarenal [Sar1, Ala8]-AII did not abolish the renal vasoconstriction in the initial 20 min of this combined blood gas derangement but resulted in a more prompt return of the renal vascular variables toward control levels with continuation of the blood gas derangement for an additional 20 min, suggesting a role for angiotensin in renal vasoconstriction. These observations suggest that while rennin—angiotensin may not mediate the initial renal vasoconstriction in the first 20 min of combined acute hypoxemia and hypercapnic acidosis, in uninephrectomized conscious dogs, it attenuates the spontaneous recovery of renal hemodynamic variables to baseline as the blood gas derangement continues.

ISSN:0886-022X    

DOI:10.3109/08860229409044863

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

The structurally related small (<5 kD) polypetides, namely thymosins beta-4 and beta-10, were originally defined in the rat immune system. Previously it was shown that both the beta-4 and beta-10 genes are constitutively expressed at higher levels in neoplastic human kidney. Also, it was shown that human embryonic kidney contained more of these proteins than the adult tis sue. The present study used a human thymosin beta-10 cDNA to examine the possibility that overexpression of the beta-10 mRNA in renal cell carcinoma was due to gene amplification. Southern blot analysis of genomic DNA extracted from normal and neoplastic tissue indicated no amplification of the thymosin beta-10 gene in RCC. No amplification or rearrangements were found in the human RAR-αgene in normal versus RCC tissue. Decreased expression of both the thymosin beta-4 and beta-10 proteins in the normal adult human kidney was found to be derived from a corresponding decrease in levels of the cognate mRNAs. These findings suggest that the thymosin beta-10 gene is deregulated in renal cell carcinoma.

ISSN:0886-022X    

DOI:10.3109/08860229409044864

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

The after effects of renal ischemia were studied in hypoxia-adapted rats. It was felt that chronic hypoxia animals which had already adapted to a low oxygen level might be more tolerant of renal ischemic insult; however, chronic hypoxia is always accompanied by polycythemia, which may cause severe RBC trapping and consequently might enhance renal damage after renal ischemia. Chronic hypoxic rats were prepared by exposure in an altitude chamber 15 h per day for 4 weeks. The plasma sodium, potassium, urea, and creatinine levels were determined to compare the changes in these parameters between the baseline and 3 h afterα45-min occlusion of both renal arteries in 12 sea-level (SLB) controls and in 12 chronic hypoxic (CHB) and II chronic hypoxic plus RBC pheresis (to reduce hematocrit: CH + P) rats. From the parameters measured, the CHB rats were found to be more tolerant of renal ischemia. However, this was not the case in the rats with pheresis. It is concluded that after chronic hypoxia, some humoral factors in the plasma may play an important role in reducing the renal damage after ischemic insult.

ISSN:0886-022X    

DOI:10.3109/08860229409044865

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

We investigated the rate of decline in GFR and the changing prevalences of micro- and macrovascular complications in 20 type II diabetic patients [mean age 58 (46–71) years.♂:♀= 7:13, duration of diabetes 16 (12–30) years] from the stage of macroproteinuria with GFRs which were still normal until the beginning of dialysis or the lime of death. Controls of renal function, proteinuria. HbAlc. serum lipids, and blood pressure were performed every 6 months at the beginning of the study and later on at 3-month intervals. Fun-doscopy. electrocardiogram at rest and in case of need a symtom-limited treadmill ECG, a Duplex ultrasound examination of the carotid vessels, and a Doppler sonographic examination of the femoral arteries were repeated each year. The creatinine clearance (mean±SD) of the patients was 81±6 mLlmin/1.73 m2at the beginning of the study. The rate of decline in creatinine clearance was 1.01±0.38 mL/min/month during the whole period of observation. Twelve patients (group A) required dialysis after a mean time of 74 (40–119) months: their creatinine clearance was 7±2 mLlminlmonth at the beginning of renal replacement therapy. Eight patients (group B) died a short lime before the beginning of dialysis treatment; their creatinine clearance was 13±5 mL/min/1.73 m2. The causes of death were sudden death (n = 4), cardiac failure (n = 1), and stroke (n = 2); in one case it was unknown. The two patient groups did not differ in respect to the mean age, duration of diabetes, HbAlc values, serum cholesterol levels, and blood pressure. The decline in the creatinine clearance was also similar in both patient groups, with 1.07±0. 35 versus 0.98±0.41 mL/min/ month. Only the mean serum triglyceride concentration was significantly higher in the patients who died before dialysis. At the start of the study, cerebrovascular disturbances (including plaques in the carotid vessels) were found in 30%, cardiovascular disturbances (including pathologic ECG findings) in 45%, a peripheral vascular disease in 15%, and diabetic retinopathy (grade I and II) in 75%. At the beginning of dialysis treatment or the time of death, respectively, the prevalence of cerebrovascular diseases was increased to 70% and the prevalence of cardiovascular diseases to 90%; peripheral vascular disease was present in 50% and diabetic retinopathy in all of the cases. We conclude that type II diabetic patients show high mortality (40%) and poor quality of life, not only when they require dialysis treatment, but also in the predialysis phase.

ISSN:0886-022X    

DOI:10.3109/08860229409044866

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

The clinical characteristics of 118 patients (60 male) with acute renal failure (ARF) admitted between 1980 and 1991, were retrospectively analyzed and compared with our earlier series of the 1960s. The mean age was 53 years (16–82 years). There was a marked decline in the hypotension-related cases (43% vs. 17%, p<0.01) and a concomitant increase in the nephro-toxic cases (5% vs. 17%, p<0.005) in recent years. The number of ARF cases significantly decreased after 1986 (31%) compared to the pre-1986 era (69%, p<0.001). A complete (35%) or partial recovery (55%) was the rule in the majority of the patients. The overall mortality was 27%, virtually unchanged in comparison to the 1960s (30%). However, a tendency toward lower mortality was seen after 1986 (17%) in comparison to before (32%, p<0.05). Sepsis and cardiovascular complications were the leading causes of death. Fewer deaths were observed among younger patients (<30 years, 12.5%) compared to middle-aged patients (30–59 years, 34%, p<0.05) and to these older than 60s (53.5%, p<0.002). Also, deaths were rare in patients with only renal involvement (6%), increasing to 30% when 2 vital organ systems were affected (p<0.005) and to 67% in cases with multiple organ failure (p<0.001). Early institution of dialysis and the nonoliguric forms of the syndrome seem to be associated with better prognosis. In conclusion, the incidence of ARF has declined in recent years, with a concomitant tendency towards lower mortality. Death rate is mainly determined by the age and the number of organ involvement. Early dialysis seems to contribute to the lower mortality seen in recent cases.

ISSN:0886-022X    

DOI:10.3109/08860229409044867

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

Urea kinetic modeling (KM) permits the calculation of urea volume (VKM), urea generation rate (GKM), and normalized protein catabolic rate (nPCRKM) but requires complex, iterative calculations. Simpler methods for estimation of these parameters (Vest, Gest, nPCRest) were compared with those obtained from kinetic modeling. Kinetic modeling was performed on 17 patients using the 3 BUN method, producing 19 data sets. All were within 25% ideal body weight and all had less than 20% difference between VKMand Vesl. Vestwas estimated as 0.195 (height) + 0.296 (weight)–14.01. Gestwas estimated, using interdialytic changes as: (BUN change±Vest) + (wt change)±(pre BUN) + U/Interdialytic interval where U is urinary urea excretion rate. nPCRestwas estimated as: (Gest×9.35) +(0.294±Vest)±(0.58/Vest) There was no significant difference (Student's t text) between mean±SD Vest(41.24±3.86 L) and VKM(40.71±5.24 L), Gest(7.23±1.92 mg/min) and GKM(7.04±2.10 mg/min), and nPCRest(1.12±0.24 g/kg/day) and nPCRKM(1.10±0.23 g/kg/day). Correlation between Vestand VKMwas poor (r2-0.56, slope = 0.41). Correlations between Gestand GKMand nPCRestand nPCRKMwere good (r2= 0.95, slope = 0.87; and r2= 0.99, slope = 1.02, respectively). Conclusion: Assessment of nutritional status using Gestand nPCRestcan be carried out with high degree of accuracy even if Vestand VKMare not identical.

ISSN:0886-022X    

DOI:10.3109/08860229409044868

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor