The evaluation of color and color difference according to the layering placement of Incisal shade composites on the body composites of the indirect resin restoration / 대한치과보존학회지

OBJECTIVES: The aim of this study was to evaluate the surface color of indirect resin restoration according to the layering placement of different shade of incisal composite. MATERIALS AND METHODS: In this study, CIE L*a*b* value of 16 Body composite of Tescera ATL (Bisco, Schaumburg IL,USA) was measured by spectrophotometer (NF999, Nippon Denshuku, Japan), and compared to CIE L*a*b* value of Vitapan shade guide. Nine shade Incisal composite of Tescera ATL were build-up to 1 mm thickness on Body composites inlay block, and CIE L*a*b* value was measured. Incisal composite was ground to 0.5 mm thickness and CIE L*a*b* value was re-measured. Color difference between Body composite and Incisal composites layered on Body composite was calculated as a function of thickness. RESULTS: Color difference between corresponding shade of Tescera Body composite and Vitapan shade guide was from 6.88 to 12.80. L* and b*value was decreased as layering thickness of Incisal composite on Body composite was increased. But, a* value did not show specific change tendency. CONCLUSIONS: Surface color difference between Body composites and Incisal composites layered on Body composite was increased as the layering thickness of Incisal composite increased (p < 0.05).

Attenuated Renal Excretion in Response to Thiazide Diuretics in Gitelman's Syndrome: A Case Report

Gitelman's syndrome is a variant of Bartter's syndrome characterized by hypocalciuria and hypomagnesemia. The administration of thiazide diuretics may induce a subnormal increase of urinary Na+ and Cl- excretion in patients with Gitelman's syndrome, consistent with the hypothesis that less Na+ and Cl- than normal is reabsorbed by the thiazide-inhibitable transporter in Gitelman's syndrome. Specific mutations of NaCl cotransporter, coupled with mutant NaCl cotransporter expression studies clearly demonstrated that many of the characteristics of individuals with Gitelman's syndrome are explained by lack of function of NaCl cotransporter. We recently diagnosed a patient with Gitelman's syndrome by performing the thiazide and furosemide tests, and it is suggested that the clearance studies by diuretic administration may be of diagnostic help in Gitelman's syndrome.

Physiologic and Pathophysiologic Roles of Aquaporin Water Channels in Rat Kidney / 대한신장학회잡지

Recent discovery of aquaporin(AQP) water channels has advanced our understanding of water transport in the kidney. They play an important role in the urinary concentration through generation of medullary hypertonicity and regulation of collecting duct water permeability. Among multiple isoforms of AQP family, AQP1 is highly expressed in the proximal tubule and descending thin limb. The critical role of AQP1 has been confirmed in transgenic mice lacking AQP1 that are unable to concentrate the urine and severely dehydrated. The abundance of AQP2 is highly expressed in the principal cell of the collecting duct. It is short-term and long-term regulated by AVP/cAMP pathway to increase the osmotic water reabsorption. The short-term regulation of AQP2 channels occurs as a result of an exocytic insertion of the cytoplasmic AQP2 vesicles into the apical membrane, whereas the long-term effect is to increase the total abundance of AQP2 proteins. Water reabsorption across the basolateral membrane of the collecting duct is in turn mediated by AQP3 and AQP4. An altered regulation of AQP channels in the kidney has been known in various pathophysiological situations. A reduced abundance of AQP water channels may at least in part account for the impaired urinary concentration in the ischemic acute renal failure and cisplatin-, gentamicin-, and amphotericin B-induced nephropathy. The postobstructive diuresis has been attributed to a decreased expression of AQP1-4 proteins in the obstructed kidney. In these situations, however, the primary impairment in the pathway leading to the generation of cAMP and hence the expression of cAMP-mediated AQP chan nels lies at the level of G proteins and/or at the catalytic unit of adenylyl cyclase. On the other hand, following the treatment with deoxycorticosterone or NG-nitro-L-arginine methyl ester, the expression of AQP2 proteins was increased in the kidney, in association with an augmented adenylyl cyclase activity. In two-kidney, one clip hypertension, the total abundance of AQP2 proteins was significantly decreased in the clipped kidney, while their trafficking remained unaltered. Concomitantly with the reversal of the blood pressure following removal of the renal arterial clip, the abundance of AQP2 expression returned to the control level. The AVP-evoked cAMP generation was decreased in the clipped kidney, and returned to the control value following removal of the clip. Following the treatment with 0.04% methimazole, the expression of AQP2 protein was increased in the kidney, in association with hyponatremia. An altered regulation of AQP water channels in the kidney may be causally related to various pathophysiological situations associated with altered urinary concentration ability and water retention.

Percutaneous Catheterization of the Internal Jugular Vein for Hemodialysis

OBJECTIVES: The present study was aimed at evaluating the clinical experiences in the internal jugular venous catheterization for hemodialysis. METHODS: We retrospectively analyzed the data on internal jugular venous catheterization at Chonnam National University Hospital from May 2000 to Februrary 2001. RESULTS: There were 132 uremic patients with a total of 150 attempts of internal jugular cannulation. Overall success rate was 90.9% with average puncture trials of 2.3+/-2.1. 124 (82.7%) of the catheterization attempts were made on the right side and 26 (17.3%) were made on the left. The catheters were left in place from 2 to 87 days with an average of 19.5+/-15.3 days per catheter. The dialysis sessions per catheter were from 2 to 58 with an average of 11.3+/-6.8. The mean blood flow during hemodialysis immediately after catheterization was 213.4+/-42.2 ml/min. Thirty two (21.3%) patients had early complications. These included carotid artery puncture (11.3%), local bleeding (4.7%), local pain (3.3%), neck hematoma (0.7%) and malposition of the catheter (1.3%). Seventeen (11.3%) patients had late complications. These included fever or infection (11.3%), inadequate blood flow rate (3.3%) and inadvertent withdrawal (2.0%). There was no catheter-related mortality. CONCLUSIONS: Our experiences revealed that the internal jugular vein catheterization is relatively safe and efficient for temporary vascular access for hemodialysis.

Dialysis Adequacy and Nutritional Status in Patients with Continuous Ambulatory Peritoneal Dialysis(CAPD) / 대한신장학회잡지

PURPOSE: Malnutrition is common in CAPD patients and depends on many factors such as dialysis-related and nondialysis-related factors. The present study aimed to assess nutritional status, dialysis adequacy and their relationships with overall mortality and morbidity. METHODS: We studied 102 patients who had been receiving CAPD for at least 6 months. Dialysis adequacy was assessed by parameters derived from urea kinetic modeling(UKM) and nutritional status was assessed by serum biochemical measurement, normalized protein catabolic rate(nPCR), normalized protein equvalent of total nitrogen appearance(nPNA) and urea kinetic studies. Spearman's simple correlation and multiple linear stepwise regression analysis were used to assess correlation between dialysis adequacy and nutritional status in CAPD patients. We compared the differences between patients who suf fered morbid events, defined as either an infectious complication or hospitalization, and patients who remained well. RESULTS: The results showed that the total dialysis dose(total weekly Kt/Vurea) has statistically significant correlation with nPCR(r=0.234, p=0.028), nPNA (r=0.246, p=0.021), total weekly creatinine clearance (WCC)(r=0.479, p=0.0001), serum albumin levels(r= 0.233, p=0.029), serum cholesterol(r=0.266, p=0.013), serum BUN(r=-0.290, p=0.006) and serum creatinine levels(r=-0.408, p=0.0001). nPNA was positively correlated with serum cholesterol(r=0.217, p=0.045), serum transferrin(r=0.218, p=0.042) and serum ferritin levels(r=0.220, p=0.043). Patients who suffered morbid events had an old age(p=0.001), long duration of CAPD(p=0.0001), higher CRP(p=0.021), lower serum albumin level(p=0.020), lower hematocrit(p=0.049) and lower WCC(p=0.017). Conclusions : These results indicate that adequate dialysis is very important for the maintenance of adequant nutrition because nutritional status positively correlated with dialysis dose, which is best assessed by UKM. In addition, assessment of nutritional status and dialysis adequacy are important in predicting clinical outcomes in CAPD patients.

Hyperhomocysteinemia in Patients with Chronic Renal Failure / 대한신장학회잡지

OBJEVTIVE: It has been reported that hyperhomocysteinemia is an independent risk factor for atherosclerotic complications, although the mechanisms remain unclear. The major determinents of total fasting plasma homocysteine(tHcy) concentrations have been recently reported but there are still conflicting data on the influence of those in peritoneal and hemodialysis patients. Therefore, we evaluated the prevalence and association of vascular complications and the determinents of hyperhomocysteinemia in chronic renal failure patients receiving conservative treatment(predialysis), peritoneal dialysis(PD) and hemodia- lysis (HD) patients. METHODS: We measured the factors, including fasting plasma vitamine levels(folate, vitamin B6 and vitamin B12), serum creatinine concentration, dialysis adequacy-related varibles as well as associated risk factors for vascular diseases that might affect tHcy concentrations in 37 predilysis, 30 PD, 34 HD patients and 21 normal persons. Continuous variables were compared using independent sample t-test. Spearman's correlation was used to determine the strength of association between tHcy and other predictive variables. Percentages were compared using Pearson's chi-square test or Fisher's exact test, depending on the frequencies. Independent determinents of tHcy concentration and atherosclerotic vascular complications were identified using multiple regression analysis. RESULTS: The prevalence of hyperhomocysteinemia was 83.8, 72, 88% among predialysis, PD and HD patients,respectively(Odds ratio was 103.33, 81.43, 150.0 vs. controls, respectively). tHcy values in predialysis, PD and HD patients are significantly higher than those in controls(24.68+/-9.01, 21.04+/-8.82, 23.62+/-9.46 vs. 8.80+/-2.07 mumoL/L, repectively, p<0.01). Predialysis, PD and HD patients with atherosclerotic vascular complications had higher tHcy concentrations than did predialysis, PD and HD patients without vascular complications(21.93+/-8.71 vs. 32.09+/-4.71 mumoL/L, p<0.01, 17.57+/-5.85 vs. 28.74+/-9.70 mumoL/L, p<0.01, 19.00+/-4.29 vs. 33.28+/-10.13, p<0.01 respectively). We also observed increasing odds ratios of vascular events with increasing tHcy concentrations. For predialysis, PD and HD patients, fasting plasma folate level had negative correlation with tHcy concentrations by spearman's simple correlaltion. And using muliple regression analysis, we recognized hyperhomocysteinemia is an independent risk factor for atherosclerosis and fasting plasma folate is a major determinent of tHcy concentrations in predialysis, PD and HD patients. CONCLUSIONS: Hyperhomocysteinemia in predialysis, PD and HD patients was more prevalent than that in normal controls. Risk of atherosclerotic vascular complications increased with increasing tHcy concentrations. Hyperhomocysteinemia is an independent risk factor for atherosclerosis and fasting plasma folate is a major determinent of tHcy concentrations in predialysis, PD and HD patients.

Altered Atrial Natriuretic Peptide System in the Kidney of Bilateral Obstructive Uropathic Rats / 대한신장학회잡지

BACKGROUND: Although being associated with an elevated plasma atrial natriuretic peptide(ANP), its precise role in the postobstructive diuresis has not been fully understood. Evidence has been provided suggesting that the locally-synthesized ANP in the kidney contributes to the regulation of urinary sodium excretion. The present study was aimed to investigate whether an altered regulation of local ANP system is involved in the postobstructive diuresis. METHODS: Male Sprague-Dawley rats were used. Both proximal ureters were ligated for 48 hours, after which the kidneys were taken without releasing the ligature, being designated as bilateral ureteral obstruction(BUO) group; or the ligature was released and 4 or 24 hr later, urinary data were collected, being designated as BUR-4 or BUR-24, respectively. Sham operated rats were used as control. Plasma ANP levels were determined by radioimmunoassay. The expression of ANP and natriuretic peptide receptor(NPR)-A mRNAs was determined by reverse transcription-polymerase chain reaction(RT-PCR). To further examine whether the altered renal ANP system, if any, was associated with an altered biological effects of guanylyl cyclase, ANP-stimulated cGMP accumulation was determined in membrane preparations of the glomeruli and papillae by radioimmunoassay. RESULTS: The plasma ANP level was increased in BUO group compared with that in the control(260.5+/-32.5 vs. 133.3+/-23.5pg/mL, p<0.05), decreased in BUR-4 group(3.6+/-0.5 vs. 143.5+/-42.8pg/mL, p<0.01), while not significantly different in BUR-24 group. In BUR-4. the urinary flow rate increased compared with that in the control(1598+/-370 vs. 215+/-34 microL/hr, p<0.01), along with increases of FENa(11.5+/-4.1 vs. 0.25+/-0.02%, p<0.05) and UNaV (153.7+/-23.7 vs. 36.5+/-9.3microEq/hr, p<0.01). In BUR-24, the urinary parameters were normalized. Renal tissue expression of ANP mRNA was increased in BUO as well as in BUR-4, while not changed in BUR-24. NPR-A mRNA expression was decreased in the kidney of BUO. The ANP-stimulated accumulation of cGMP in the isolated glomeruli and papillae in BUO was significantly reduced. The guanylyl cyclase activities were partly recovered in BUR-4 and completely in BUR-24. CONCLUSION: An enhanced local activity of ANP in the kidney may be causally related to the postobstructive diuresis.

Decreased Formation of Nitric Oxide in Rats Treated with FK506 / 대한신장학회잡지

The present study was aimed at investigating whether FK506 alters the regulation of nitric oxide(NO) system. Male Sprague-Dawley rats were treated with FK506(1 mg/kg/day, i.m.) for 3 weeks. Control group was without treatment of FK506. Plasma levels and urinary excretion of NO metabolites(nitrite/nitrate, NOx) were measured. The protein expression of NO synthases(NOS) and tissue contents of NOx were determined in the kidney and thoracic aorta. The aorta was also examined of its changes in isometric tension in responses to acetylcholine and sodium nitroprusside. The arterial pressure did not significantly differ between FK506-treated and control groups. Plasma NOx levels remained unaltered, while urinary NOx excretion was significantly decreased in FK 506-treated group. Tissue contents of NOx were significantly decreased, although the expression of ecNOS and iNOS proteins was significantly altered neither in the kidney nor in the aorta. Acetylcholine-induced relaxation of the isolated aortic ring was significantly attenuated, whereas sodium nitroprusside-induced relaxation was not significantly affected. These results suggest that FK506 decreases the tissue contents of NO, without significantly affecting the expression of NOS.

A Case of life-threatening Angioneurotic Edema Related to Angiotensin Converting Enzyme Inhibitor in a Patient with Systemic Lupus Erythematosus / 대한신장학회잡지

No abstract available.

Relationship Between Serum Magnesium and Parathyroid Hormone Levels in Hemodialysis Patients / 대한신장학회잡지

The important factors involved in the regulation of PTH are calcium, vitamin D, and phosphorus. However, recent studies have suggested that magnesium may also play a significant role in the modulation of PTH. The aims of this study was to analyze the relationship between serum magnesium and PTH levels in the hemodialysis patients. We studied 66 stable patients under maintenance hemodialysis for more than 6 months. Calcium carbonate was used as a phosphate binder in all patients. No patient had been previously treated with vitamin D and aluminum hydroxide. Biochemical parameters were evaluated 3 times during 7 months, and the mean values were computed. The mean serum magnesium level was 2.7+/-0.4 mEq/L. Hypermagnesemia(defined as serum Mg>2.2 mEq/L) was found in 60 patients(90.1%). Serum magnesium levels were inversely correlated with serum iPTH levels(r=-0.579; p<0.001). Serum total and ionized calcium levels were inversely correlated with serum iPTH levels(r=-0.743; p<0.001, r=-0.699; p<0.001, respectively). Serum alkaline phosphatase levels positively correlated with serum iPTH levels (r=0.364; p=0.003). In lower iPTH group(serum iPTH

Prevalence and Determinants of Hyperhomocysteinemia in Patients with Chronic Renal Failure / 대한신장학회잡지

BACKGROUND: Hyperhomocysteinemia plays an important role in atherosclerosis resulting from endothelial dysfunction and injury followed by platelet activation and thrombus formation. We evaluated the prevalence and determinants of hyperhomocysteinemia in patients with chronic renal failure(CRF) and relationship between hyperhomocysteinemia and cardiovascular diseases. METHODS: We evaluated the prevalence of hyperhomocysteinemia in CRF patients and hemodialysis patients. Fasting plasma homocysteine, vitamin B12, vitamin B6, creatinine, fibrinogen, lipoprotein(a), glucose, total cholesterol, HDL cholesterol, and TG levels were assessed in 69 patients. RESULTS: Hyperhomocysteinemia was detected 5% in controls, 86% in CRF groups, and 85% in hemodialysis group. Serum folate value in hemodialysis group was significantly higher than normal controls (10.7+/-4.8 vs. 15.3+/- 5.4nmoL/L; p<0.05). Plasma homocysteine concentration negatively correlated with serum folate level in hemodialysis patients(r=-0.42, p<0.05). Cardiovascular diseases were deteceted 14% in CRF patients and 25% in hemodialysis patients. Matched odds ratios(with 95% confidence intervals) were respectively 118.75, 107.7 for homocysteine in CRF and hemodialysis patients compaired with control group. CONCLUSION: Plasma homocysteine level correlated negatively with serum folate level in hemodialysis patients. In univariate analysis, determinant of plasma homocysteine concentration in hemodialysis patients is plasma folate concentration. We considered that hyperhomocysteinemia is also an independent risk factor of cardiovascular diseases.

Serum Lipids and Lipoproteins in Patients with Chronic Renal Failure / 대한신장학회잡지

We measured serum lipoprotein (a) [Lp (a)] concentrations in 304 uremic patients treated on predialysis, hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD), and compared them with those in 43 normal controls. The mean values were 46.1mg/dl in predialysis, 35.7mg/dl in HD, 54.7mg/dl in CAPD patients and 17.0mg/dl in controls, respectively. Serum Lp (a) levels were elevated both in the predialysis patients (P<0.001) and in the CAPD patients (P<0.001) compared with those in controls, and were also elevated in the CAPD patients (P<0.01) compared with HD patients. Serum Lp (a) levels tended to be higher in HD patients compared with controls, although these differences did not reach statistical significance. We observed statistically significant positive correlations of Lp (a) to serum levels of total cholesterol (TC) (r=0.279, P<0.01), LDL-cholesterol (r=0.335, P<0.01), and Apo (B) (r=0.352, P<0.01), and significant negative correlation of Lp (a) to serum level of albumin (r=-0.278, P<0.01) in 304 CRF patients. CAPD patients had a more atherogenic lipoprotein profile than did HD patients; besides significantly higher Lp (a) levels (P<0.01), total (P<0.001) and LDL (P<0.001) cholesterol, triglycerides (P<0.05), and apo (B) (P<0.001) were significantly elevated in comparison to HD patients. The marked elevation of serum Lp (a) in patients on CAPD may be due to increased hepatic synthesis as a consequence of the substantial amounts of plasma proteins lost in the dialysate. The increased serum concentrations of Lp (a) may contribute to the high risk for atherosclerosis in end stage renal disease, especially in patients treated by CAPD.