Sialolitíase em equino: relato de caso / Sialolithiasis in equine: case report

Sialolitíase é uma afecção que afeta as glândulas salivares ou seus ductos, caracterizada pela presença de estruturas calcificadas, denominadas de sialolitos, com crescimento lento e gradual, geralmente assintomático, dificultando ou impedindo o fluxo normal de saliva. Devido à ausência de relatos na literatura nacional, descreve-se o caso de uma égua de 15 anos, que apresentava um sialolito de 13cm no ducto parotídico havia mais de dois anos, próximo à crista facial. O diagnóstico foi realizado por meio do exame clínico: visualização do aumento de volume, palpação do sialolito, avaliação odontológica; e de exames complementares: radiografia e ultrassonografia. Optou-se pelo tratamento cirúrgico, através do acesso percutâneo, pois é o mais indicado para cálculos grandes, realizando-se sutura do ducto de Stenon, sem presença de fístulas no pós-operatório. Foi de extrema importância a avaliação e os cuidados odontológicos durante a realização do procedimento, pois as pontas dentárias facilitam a formação dos cálculos.(AU)

Sialolithiasis is a condition that affects the salivary glands or their ducts, characterized by the presence of calcified structures, called sialolites, with slow and gradual growth, usually asymptomatic, hindering or impeding the normal flow of saliva. Due to the absence of reports in the national literature, the case of a 15-year-old mare who had a 13cm sialolite in the parotid duct near the face ridge for more than 2 years is described. The diagnosis was made through clinical examination: with visualization and palpation of the sialolite, dental evaluation; and complementary exams: radiography and ultrasonography. We chose surgical treatment through percutaneous access, which is the most appropriate for large stones, and Stenon's duct suture was performed, without postoperative fistulas. The assessment and dental care during the procedure was extremely important, since the dental tips facilitate the formation of the stones.(AU)

Oral malodorous compound causes caspase-8 and -9 mediated programmed cell death in osteoblasts.

BACKGROUND AND OBJECTIVE: Hydrogen sulfide (H(2) S) is one of two volatile sulfur compounds that are known to be the main cause of oral malodor; the other is methyl mercaptan. Other known volatiles existing in mouth air do not contribute significantly to oral malodor originating in the oral cavity. Hydrogen sulfide is also known to be an etiological factor in periodontal disease. However, the effects of H(2) S on alveolar bone remain unclear. The objectives of this study were to determine the apoptotic effects of H(2) S on osteoblasts and to verify the apoptotic molecular pathways. MATERIAL AND METHODS: A clonal murine calvaria cell line was incubated with 50 ng/mL of H(2) S. To detect apoptosis, the cells were analysed by flow cytometry and ELISA. Mitochondrial membrane depolarization was assessed using flow cytometry as well. ELISA was used to evaluate the release of cytochrome c into the cytosol and to assess Fas ligand, p53, tumor necrosis factor α, interleukin IL1-α IL-ß, IL-2, IL-4, IL-10, interferon-γ, granulocyte-colony stimulating factor and granulocyte-macrophage colony stimulating factor. Caspase-3, -8 and -9 activities were estimated. Expression of BAX and Bcl-2 was assessed by real-time quantitative RT-PCR. DNA fragmentation was detected by single-cell gel electrophoresis. Fas receptors were evaluated by western blotting. RESULTS: After H(2) S incubation, apoptotic levels increased significantly in a time-dependent manner. Mitochondrial membrane depolarization, the release of cytochrome c, p53 and caspase-3, -8 and -9 and DNA fragmentation were all significantly greater. BAX gene activity was upregulated, whereas Bcl-2 remained low. Fas ligand/Fas receptor, tumor necrosis factor α and other cytokines were not increased to a significant degree. CONCLUSION: At less-than-pathological concentrations in gingival crevicular fluid, H(2) S induces apoptosis in osteoblasts. The molecular mechanisms underlying the apoptotic process include p53, a mitochondrial pathway and caspase-8 activation.

Ecotoxicological characterization of tannery wastewater in Dhaka, Bangladesh.

Tanning industries are one of the main economic activities in Bangladesh. It has been well documented that wastewater discharged from tanneries without appropriate treatment results in detrimental effects on the ecosystem. No ecotoxicity evaluation of any aquatic environment in Bangladesh has been conducted so far. In this study a battery of toxicity bioassays and chemical analysis were carried out from water samples obtained from three sampling points: upstream from discharging site on River Buriganga (S1), raw wastewater effluent (S2), and downstream the discharging sluice gate (S3), in the Hazaribagh tannery area of Dhaka City, Bangladesh. While S1 and S3 water samples did not show significant toxicity in the bioassays tested, S2 exhibited high acute toxicity to the bacterium Vibrio fischeri (15-min Microtox test, EC50 = 9.8%), the higher plant Lactuca sativa (5-day root elongation inhibition test, EC50 = 14.2%), and the microcrustacean Daphnia magna (24-hour mobility test, EC50 = 31.5%). The results suggested that the raw wastewater effluent had detrimental effects on broad spectrum of organisms in the aquatic ecosystem and bacterium was the most sensitive. The chemical analysis revealed that sample S2 contained an extremely high concentration of chromium (47 g l(-1)). Additionally microbiological analysis indicated that the sampling area is impacted by fecal pollution, increasing the environmental health risk for its inhabitants.

Oral malodorous compound triggers mitochondrial-dependent apoptosis and causes genomic DNA damage in human gingival epithelial cells.

BACKGROUND AND OBJECTIVE: Volatile sulfur compounds are the main compounds causing halitosis. One of these compounds, hydrogen sulfide (H(2)S), which is responsible for physiological halitosis, is reported also to have periodontal pathogenic activities. Hydrogen sulfide has been shown to activate the apoptotic process in different tissues. Apoptosis plays an important role in the development of periodontitis. The aim of this study was to determine whether H(2)S causes apoptosis in human gingival epithelial cells and to examine the cellular signaling pathway initiating the process. MATERIAL AND METHODS: Human gingival epithelial cells were incubated with 50 ng/mL H(2)S in air contining 5% CO(2) for 24, 48 or 72 h. To detect apoptosis, the cells were stained with annexin V and 7-amino actinomycin D, and analyzed using flow cytometry. Reactive oxygen species, mitochondrial membrane depolarization and release of cytochrome C into the cytosol were assessed using flow cytometry and enzyme-linked immunosorbent assay. Activity levels for the key apoptotic enzymes caspase-9, -8 and -3 were also determined. Genomic DNA damage was detected using single-cell gel electrophoresis. RESULTS: Apoptosis was significantly increased to 24.5 +/- 5.7 at 24 h and 41.5 +/- 8.9% at 48 h (p < 0.01). Reactive oxygen species were enhanced and mitochondrial membrane depolarization was collapsed. Cytochrome C release was dramatically increased (0.12 +/- 0.02 vs. 0.02 +/- 0.01 at 24 h and 0.21 +/- 0.02 vs. 0.02 +/- 0.01 ng/mL at 48 h; p < 0.05). Caspase-9 and -3 were strongly activated, while caspase-8 activity remained low. The percentage of DNA strand breaks increased, especially at 48 h. CONCLUSION: Hydrogen sulfide induces apoptosis in human gingival epithelial cells by activating the mitochondrial pathway.

Toxicity of four antifouling biocides and their mixtures on the brine shrimp Artemia salina.

Zinc pyrithione (ZPT), Copper pyrihione (CPT), Chlorothalonil and Diuron are four of the most widely used as alternative to tributlytin (TBT) antifouling biocides in boat paints. As most previous laboratory bioassays for these biocides have been conducted solely based on acute tests with a single compound, information on the possible combined toxicity of these common biocides to marine organisms are limited. In this study, the toxicity of binary (in several proportions), ternary and quaternary mixtures were evaluated using the brine shrimp Artemia salina as test organism. Mixture toxicities were studied using the concentration addition model (isobolograms and toxic unit summation), and the mixture toxicity index (MTI). The ZPT-CPT combination had a strictly synergistic effect which requires attention because the coexistence of ZPT and CPT in the marine environment, due to transchelation of ZPT, may occur. The binary mixtures of Diuron with the metal pyrithiones exhibited various interactive effects (synergistic, antagonistic or additive) depending on concentration ratios, whereas all binary mixtures that contained Chlorothalonil exhibited antagonistic effects. The different types of combined effects subsequent to proportion variation of binary mixtures underline the importance of the combined toxicity characterization for various ratios of concentrations. The four ternary mixtures tested, also exhibited various interactive effects, and the quaternary mixture exhibited synergism. The models applied were in agreement in most cases. The observed synergistic interactions underline the requirement to review water quality guidelines, which are likely underestimating the adverse combined effects of these chemicals.

Antifouling herbicides in the coastal waters of western Japan.

Residue analyses of some antifouling herbicides (Diuron, Irgarol 1051 and the latter's degradation product M1, which is also known as GS26575), were conducted in waters collected along the coast of western Japan. In total, 142 water samples were collected from fishery harbours (99 sites), marinas (27 sites), and small ports (16 sites) around the Seto Inland Sea, the Kii Peninsula, and Lake Biwa, in August 1999. A urea-based herbicide, Diuron, was positively identified for the first time in Japanese aquatic environments. Diuron was detected in 121 samples (86%) up to a highest concentration of 3.05 microg/l, and was found in 86% of samples from fishery harbours, 89% from marinas, and 75% from ports. Four freshwater samples out of 11 collected at Lake Biwa contained Diuron. Neither Irgarol 1051 nor M1 was found in the lake waters, but both were found in many coastal waters. Irgarol 1051 was found in 84 samples (60%) at a highest concentration of 0.262 microg/l. The concentrations detected were of similar magnitude to those in our previous surveys, taken in 1997 and 1998. M1 was found in 40 samples (28%) up to a highest concentration of 0.080 microg/l. The concentrations detected were generally lower than those found in our previous surveys. The detection frequency among fishery harbours, marinas, and ports was 57-70% for Irgarol 1051 and 25-30% for M1. Ninety-five per cent of the coastal waters in which M1 was detected also contained Irgarol 1051, and 93% of the samples in which Irgarol 1051 was detected also contained Diuron. These results clearly suggest that commercial ship-bottom paints containing both Diuron and Irgarol 1051 are used extensively in the survey area.

Biomarker study of a municipal effluent dispersion plume in two species of freshwater mussels.

The toxicological effects of a primary-treated municipal effluent plume were investigated in two species of freshwater mussels, Elliptio complanata and Dreissena polymorpha, exposed for 62 days at sites upstream and downstream of an effluent outfall in the St. Lawrence River (Quebec, Canada). Levels of metallothioneins (MT), cytochrome P4501A1 activity, DNA damage, total lipids, relative levels of vitellins, and phagocytic activity (in E. complanata hemocytes) were determined after the exposure period. A parallel analysis measured heavy metals and coprostanol in mussel tissues. The results show that significant levels of coprostanol and some metals (specifically, Cu, Hg, Sb, Se, and Zn) had accumulated in mussels caged 5 km downstream of the effluent plume. Mixed-function oxidase activity, MT in gills, total lipids, DNA damage (in D. polymorpha only), and total hemolymph bacteria (in E. complanata only) had increased in these mussels, while levels of total cadmium (Cd), MT in digestive glands or whole soft tissues, phagocytic activity, and DNA damage in the digestive gland (in E. complanata only) were diminished. The exposure of mussels to surface waters contaminated by a municipal effluent led to many stress responses, depending on both the tissues and the species being examined.

Toxicity evaluation of new antifouling compounds using suspension-cultured fish cells.

A simple, rapid toxicity test was developed using the suspension-cultured fish cell line CHSE-sp derived from chinook salmon Oncorhynchus tshawytscha embryos in order to assess the toxicity of new marine antifouling compounds. The compounds tested were copper pyrithione, Diuron, Irgarol 1051, KH101, Sea-Nine 211, and zinc pyrithione, all of which have been nominated in Japan as possible replacements for organotin compounds. The in vitro acute toxicity (24-h EC50) of the six compounds to these fish cells was evaluated using the dye Alamar Blue to determine cell viability, and then correlated with the results of in vivo chronic toxicities (28-day LC50) to juvenile rainbow trout Oncorhynchus mykiss. The suspension-cultured fish cells were found to be suitable for the screening of such chemicals before performing an in vivo test. The toxicities of the test compounds obtained from both tests, shown in decreasing order, were as follows: copper pyrithione > zinc pyrithione > KH101 > or = Sea-Nine 211 > Diuron > Irgarol 1051. The herbicides Diuron and Irgarol 1051 showed the least toxicity, while the pyrithiones had the greatest toxicity.

Distribution characteristics of acid-dissolved trace metals of suspended particulate matter (SPM) in Kurashiki, Japan.

This study was undertaken to examine the distribution characteristics of such trace metals in fine particulate (especially with diameters of less than 2.1 microns). The acid-dissolved metals in suspended particulate matter (0.1-9.0 microns) were examined with consideration given to particle size over a 2-year period. It became clear the metals of artificial origin such as Pb, V, Cd, Ni, Cr exist in fine particulates (0.1 or more 2.0 microns), whereas metals of natural origin, such as Ti, Mn, Mg, and Sr primarily exist in coarse particles (2.1-9.0 microns) in Kurashiki City, near the Mizushima Industrial Area in Japan.

An oral adsorbent ameliorates renal overload of indoxyl sulfate and progression of renal failure in diabetic rats.

Otsuka Long-Evans Tokushima Fatty (OLETF) rats were established as a new model of non-insulin-dependent diabetes mellitus. An oral adsorbent, AST-120, is effective in removing such uremic toxins as indoxyl sulfate and delays the progression of chronic renal failure (CRF). This study was designed to determine the effects of AST-120 on the progression of CRF in uninephrectomized OLETF (1/2NxOLETF) rats and the localization of indoxyl sulfate in their kidneys. Four weeks after unilateral nephrectomy, 14 OLETF rats were divided into two groups; AST-120-administered and control 1/2NxOLETF rats. Long-Evans Tokushima Otsuka rats, which are genetically similar to the OLETF rats but not diabetic, were also included. After the administration of AST-120 for 36 weeks, we examined the effects of AST-120 on renal functional and pathological changes in the three groups. The control 1/2NxOLETF rats showed marked hyperglycemia, hyperlipidemia, renal failure, glomerular sclerosis, and tubulointerstitial injury. The administration of AST-120 to the 1/2NxOLETF rats retarded the progression of renal dysfunction and fibrosis, as well as hyperlipidemia, and reduced serum and urinary levels of indoxyl sulfate. Immunohistochemistry showed that AST-120 markedly reduced the overload of indoxyl sulfate in tubular epithelial cells, especially dilated tubules, of the 1/2NxOLETF rats. In conclusion, AST-120 delayed the progression of renal failure and fibrosis in 1/2NxOLETF rats and decreased the overload of indoxyl sulfate on renal tubular cells.

Acceleration of fracture healing in nonhuman primates by fibroblast growth factor-2.

One of the greatest needs in the clinical bone field is a bioactive agent to stimulate bone formation. We previously reported that fibroblast growth factor-2 (FGF-2) exhibited strong anabolic actions on bone formation in models of rodents and dogs. Aiming at a clinical application, this study was undertaken to clarify the effect of a single local application of recombinant human FGF-2 on fracture healing in nonhuman primates. After a fracture was created at the midshaft of the right ulna of animals and stabilized with an intramedullary nail, gelatin hydrogel alone (n = 10) or gelatin hydrogel containing 200 microg FGF-2 (n = 10) was injected into the fracture site. Although 4 of 10 animals treated with the vehicle alone remained in a nonunion state even after 10 weeks, bone union was complete at 6 weeks in all 10 animals treated with FGF-2. Significant differences in bone mineral content and density at the fracture site between the vehicle and FGF-2 groups were seen at 6 weeks and thereafter. FGF-2 also increased the mechanical property of the fracture site. We conclude that FGF-2 accelerates fracture healing and prevents nonunion in primates, and therefore propose that it is a potent bone anabolic agent for clinical use.

An oral sorbent reduces overload of indoxyl sulphate and gene expression of TGF-beta1 in uraemic rat kidneys.

BACKGROUND: An oral adsorbent (AST-120) delays the progression of chronic renal failure (CRF). The aims of the present study are to determine the effects of AST-120 on the localization of indoxyl sulphate in uraemic rat kidneys, and to examine whether AST-120 reduces the renal cortical gene expression of transforming growth factor (TGF)-beta1, tissue inhibitor of metalloproteinase (TIMP)-1 and pro-alpha1(I)collagen, and ameliorates glomerular and tubulointerstitial injuries in uraemic rats. METHODS: Two weeks after 5/6-nephrectomy, 10 rats were divided into pairs such that both rats in each pair exhibited almost the same levels of serum creatinine, blood urea nitrogen and creatinine clearance. One rat from each pair was assigned to a control uraemic group, the other to a uraemic group which received AST-120 everyday for 11 weeks. The localization of indoxyl sulphate was studied by immunohistochemistry using a monoclonal anti-indoxyl sulphate antibody we had developed. The renal cortical gene expression was studied by using northern blotting. RESULTS: Rats treated with AST-120 showed decreased levels of serum creatinine, blood urea nitrogen and urinary protein as well as increased levels of creatinine clearance as compared with control uraemic rats. AST-120 markedly decreased indoxyl sulphate levels in both serum and urine. Immunohistochemistry demonstrated that indoxyl sulphate was localized in the renal proximal tubular epithelial cells, especially of dilated tubules, and that AST-120 markedly reduced the tubular staining of indoxyl sulphate. AST-120 attenuated interstitial fibrosis, tubular injury as well as glomerular sclerosis, and reduced the renal gene expression of TGF-beta1, TIMP-1 and pro-alpha1(I)collagen. CONCLUSIONS: AST-120 reduces the gene expression of TGF-beta1, TIMP-1 and pro-alpha1(I)collagen in the kidneys, and delays the progression of CRF, at least in part, by alleviating the overload of indoxyl sulphate on remnant proximal tubular epithelial cells.

Promoted bone healing at a rabbit skull gap between autologous bone fragment and the surrounding intact bone with biodegradable microspheres containing transforming growth factor-beta1.

This study is a trial to promote repairing of the rabbit skull bone gap between an autologous bone flap and the intact bone with biodegradable gelatin microspheres containing transforming growth factor-beta1 (TGF-beta1). A 10-mm diameter bone defect was prepared in rabbit skulls by drilling out a bone flap of 6 mm in diameter. After a surrounding gap defect of 2 mm was created and treated with 0.5 microg of free TGF-beta1 and gelatin microspheres containing 0.5 microg of free TGF-beta1, the circular autologous bone flap was placed in the center. Significant bone healing at the gap defect was observed 3 weeks after implantation of the TGF-beta1-containing gelatin microspheres. The bone mineral density (BMD) was significantly higher than that of other experimental groups. On the contrary, when applied with free TGF-beta1, a fibrous tissue initially infiltrated into the gap defect, resulting in impairing bone healing. The tissue response was similar to that at the defect implanted with empty gelatin microspheres and TGF-beta1-free phosphate-buffered saline solution alone. There was more space in the gap-filling bone in the 16-week view than the 3-week view. It is possible that this was an intermediate step along the way toward normal healing and formation of cancellous bone. We conclude that gelatin microspheres containing TGF-beta1 show promise as an agent to promote bone regeneration of subcritical size defects between surgically positioned autologous bone flaps and surrounding host bone.

Oral adsorbent AST-120 ameliorates interstitial fibrosis and transforming growth factor-beta(1) expression in spontaneously diabetic (OLETF) rats.

Diabetic nephropathy is a common cause of end-stage renal disease. The administration of an oral adsorbent, AST-120, prevents the progression of chronic renal failure in uremic rats and undialyzed uremic patients. This study was designed to determine if AST-120 slows the progression of diabetic nephropathy using Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of non-insulin-dependent diabetic mellitus. At 21 weeks of age the OLETF rats were divided into 2 groups: AST-120-administered OLETF rats (n = 7), and control OLETF rats (n = 7). LETO rats, which are genetically similar to the OLETF rats but not diabetic, were also included. After the oral administration of AST-120 for 65 weeks, renal function and pathological changes were investigated in the 3 groups. The administration of AST-120 to the OLETF rats attenuated the progression of glomerular sclerosis, interstitial fibrosis, tubular injury as well as renal dysfunction, and reduced the serum and urinary levels of indoxyl sulfate. Furthermore, AST-120 administration reduced the interstitial expression of transforming growth factor (TGF)-beta(1) and tissue inhibitor of metalloproteinase (TIMP)-1, as well as interstitial infiltration of macrophages. The TGF-beta(1)-stained interstitial area showed positive correlations with the interstitial fibrosis area, the number of TIMP-1-positive cells, and the number of macrophages, and showed a negative correlation with creatinine clearance. In conclusion, AST-120 reduced the interstitial expression of TGF-beta(1) and TIMP-1, and the interstitial infiltration of macrophages, and ameliorates the progression of diabetic nephropathy in OLETF rats.

Application of short-term bioassay guided chemical analysis for water quality of agricultural land run-off.

The effect of agricultural land run-off on the water quality of Lake Kojima, Japan, was investigated using a short-term bioassay-guided chemical analysis. Water samples were collected for 1 year starting from June 1995 to June 1996. Toxicity of the dissolved and adsorbed extracts in the water samples was evaluated using the Daphnia immobilization test and the concentrations of pesticides and putative toxic substance in the extracts were determined by high performance liquid chromatography. Most of the dissolved extracts caused immobilization of the test Daphnia magna at low concentrations during the period of paddy pesticide application. Some extracts were found to contain pesticides such as dymron, mefenacet and flutolanil, but their concentrations were too low to have a toxic effect on the daphnia. An unknown toxic compound, Peak C, was isolated from some river water samples, but it produced only a relatively weak toxicity to Daphnia. To better understand the impact of agricultural run-off on a receiving water body, the relationship between the observed toxicity and the concentrations of pesticides and Peak C in the water samples was studied both temporally and spatially.

Oral adsorbent ameliorates renal TGF-beta 1 expression in hypercholesterolemic rats.

BACKGROUND: A spontaneously hypercholesterolemic Imai rat has recently been reported as a model of focal glomerulosclerosis that causes nephrotic syndrome followed by renal failure. This study was designed to determine if an oral adsorbent, AST-120, ameliorates renal lesions and TGF-beta 1 expression in the rats. METHODS: AST-120 was given orally to the Imai rats for 32 weeks, and renal function and pathology were compared between the AST-120-administered and control Imai rats. RESULTS: AST-120-administered rats showed significantly lower level of blood urea nitrogen, serum creatinine, urinary protein, serum total-cholesterol, serum triglyceride, and serum and urinary indoxyl sulfate, and significantly higher levels of serum albumin and creatinine clearance than control rats. AST-120 reduced the glomerular sclerosis index, interstitial fibrosis area, and the extent of glomerular lipid deposition. Immunohistochemistry demonstrated that AST-120 reduced the expression of transforming growth factor (TGF)-beta 1 and tissue inhibitor of metalloproteinase (TIMP)-1 as well as interstitial infiltration of macrophages in the renal cortex of the Imai rats. CONCLUSIONS: AST-120 prevented the progression of nephrotic syndrome and renal failure in the Imai rats by ameliorating glomerular sclerosis and interstitial fibrosis, accompanied with reduced expression of TGF-beta 1 and TIMP-1, and reduced infiltration of macrophages in the kidneys.

Toxicity of organic and inorganic mercury to Saccharomyces cerevisiae.

In this study the effect if six different forms of mercury on the growth of the yeast Saccharomyces cerevisiae is presented. Five kinds of strains of S. cerevisiae were used. They were a wild type, a mercury-resistant type, and three mutants: mutation repair-deficient mutant, excision repair-deficient mutant, and recombination repair-deficient mutant. In terms of EC50 toward the wild-type strain, the toxicity order for the inorganic forms was Hg(NO3)2>HgSO4>HgCl2. Monovalent nitrate mercury Hg(NO3)2 was more toxic than bivalent Hg(NO3)2. The toxicity of organic mercury CH3HgCl on cell growth was two orders of magnitude higher than that of inorganic HgCl2. Between the two organic forms, CH3HgCl was more toxic than CH3HgOH. The survival rate in the presence of a certain concentration of CH3HgCl was about one-hundredth of the survival in presence of the same concentration of HgCl2. On the other hand, the concentration of CH3HgCl in the cell was about 170 times that of HgCl2. The addition of chelating agents, EDTA and methyl-penicillamine, to the medium did not reduce the toxicity of mercury. Among the three mutants tested, the one deficient in recombination repair systems was the most sensitive to mercury.

Increased erythrocyte 3-DG and AGEs in diabetic hemodialysis patients: role of the polyol pathway.

BACKGROUND: 3-Deoxyglucosone (3-DG) accumulating in uremic serum plays an important role in the formation of advanced glycation end products (AGEs). To determine if 3-DG is involved in the formation of intracellular AGEs, we measured the erythrocyte levels of 3-DG and AGEs such as imidazolone and N epsilon-carboxymethyllysine (CML) in hemodialysis (HD) patients with diabetes. Further, to determine if the polyol pathway is involved in the formation of erythrocyte 3-DG and AGEs, an aldose reductase inhibitor (ARI) was administered to these patients. METHODS: The erythrocyte levels of sorbitol, 3-DG, imidazolone, and CML were measured in ten diabetic HD patients before and after treatment with ARI (epalrestat) for eight weeks, and were compared with those in eleven healthy subjects. 3-DG was incubated in vitro with hemoglobin for two weeks to determine if imidazolone and CML are formed by reacting 3-DG with hemoglobin. RESULTS: The erythrocyte levels of sorbitol, 3-DG, imidazolone, and CML were significantly elevated in diabetic HD patients as compared with healthy subjects. The erythrocyte levels of 3-DG significantly decreased after HD, but sorbitol, imidazolone or CML did not. The administration of ARI significantly decreased the erythrocyte levels of sorbitol, 3-DG and imidazolone, and tended to decrease the CML level. Imidazolone was rapidly produced in vitro by incubating 3-DG with hemoglobin, and CML was also produced, but less markedly as compared with imidazolone. CONCLUSION: The erythrocyte levels of 3-DG and AGEs are elevated in diabetic HD patients. The administration of ARI reduces the erythrocyte levels of 3-DG and AGEs, especially imidazolone, as well as sorbitol. Thus, 3-DG and AGEs, especially imidazolone, in the erythrocytes are produced mainly via the polyol pathway. ARI may prevent diabetic and uremic complications associated with AGEs.

Urinary indoxyl sulfate is a clinical factor that affects the progression of renal failure.

We recently demonstrated that indoxyl sulfate is a stimulating factor for the progression of chronic renal failure (CRF). In this study we determined whether the urine or serum levels of indoxyl sulfate are related to the progression rate of CRF in undialyzed uremic patients. Fifty-five CRF patients with a serum creatinine of >2 mg/dl who had not been treated with an oral sorbent (AST-120) were randomly enrolled in the study. We measured the serum and urine levels of indoxyl sulfate, and estimated the recent progression rate of CRF as the slope of the reciprocal serum creatinine versus time (1/S-Cr-time) plot. The mean urinary amount of indoxyl sulfate in the patients was 60 mg/day. Those with indoxyl sulfate urine levels of >60 mg/day had a significantly faster progression rate of CRF than those with <60 mg/day. Especially, those patients with indoxyl sulfate urine levels of >90 mg/day had the highest CRF progression rate and those with indoxyl sulfate urine levels of <30 mg/day had the slowest CRF progression rate. Urinary indoxyl sulfate had a significantly negative correlation with the slope of the 1/S-Cr-time plot. However, the serum level of indoxyl sulfate or the ratio of serum indoxyl sulfate to creatinine was not significantly correlated with the slope of the 1/S-Cr-time plot. In conclusion, high urine levels of indoxyl sulfate are related with a rapid progression of CRF in undialyzed uremic patients. Thus, urinary indoxyl sulfate is one of the clinical factors that affect CRF progression.

Preventive effects of an oral sorbent on nephropathy in rats.

Circulating uremic substances are thought to be involved in the progression of chronic renal failure (CRF). An oral adsorbent AST-120 (Kremezin) is effective in removing circulating uremic toxins from the gastrointestinal tract, and retards the progression of CRF. AST-120 is widely used as an approved drug in Japan for the treatment of undialyzed uremic patients to delay the progression of CRF. AST-120 attenuates the progression of glomerular sclerosis and interstitial fibrosis in a variety of experimental rat models of CRF. However, the mechanism by which AST-120 delays the progression of CRF had not been clear. We have demonstrated that indoxyl sulfate, a dietary protein metabolite, is a circulating uremic toxin stimulating glomerular sclerosis and interstitial fibrosis, and that AST-120 decreases the serum and urine levels of indoxyl sulfate by adsorbing its precursor, indole, in the intestine. The administration of indoxyl sulfate to uremic rats stimulated the expression of transforming growth factor (TGF)-beta1, tissue inhibitor of metalloproteinase (TIMP)-1 and pro-alpha1(I)collagen in the kidneys. Further, the administration of AST-120 to uremic rats reduced the extent of glomerular sclerosis and interstitial fibrosis as well as the renal expression of TGF-beta1 and TIMP-1, by reducing the serum and urine levels of indoxyl sulfate. We propose the protein metabolite hypothesis that endogenous protein metabolites such as indoxyl sulfate play an important role in the progression of CRF, and that AST-120 is effective in retarding the progression of CRF by removing these protein metabolites through intestinal absorption.