In fulminant hepatic failure, various toxins causing multi-organ failure increase in plasma. As a novel toxin, ceramide, a well-studied lipid mediator of apoptosis, levels were determined by LC-MS/MS in the liver and plasma of D-galactosamine-intoxicated rats. 18 and 24h after intraperitoneal administration of D-galactosamine (1g/kg body weight) to rats, fulminant hepatic failure occurred as evidenced by a severe elevation in plasma GOT and GPT. The liver concentration of minor ceramide components (C18:0, C20:0, C22:1, C22:0, and C24:2) increased significantly compared to that in the control group that was given saline. The plasma concentration of major ceramides (C24:0, C24:1, C16:0, C22:0, C22:1, and C18:0) increased 24h after administration of D-galactosamine and the total ceramide concentration was also increased to 3.6 times that in the control. In conclusion, the increased concentrations of ceramides in plasma during fulminant hepatic failure may be one of important toxins causing damage in other organs including the brain and kidney.

Toxicity of arsenic was investigated in the gill of Lamellidens marginalis by exposing the animals to sublethal concentrations of sodium arsenite for a maximum period of 30 days in controlled laboratory conditions. Arsenite exposure inhibited the activities of acid phosphatase (ACP), alkaline phosphatase (ALP), glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and acetylcholinesterase (AChE) in a dose and time dependent manner. Depletion in cytotoxic molecule like nitric oxide (NO) and suppression of phenoloxidase (PO) activity suggests an immune compromise in the animal. Inhibition in the activities of glutathione-s-transferase (GST) and catalase (CAT) in the species indicate impairment of its vital detoxification process and elevated oxidative stress respectively. Histopathology of the gill indicates arsenite induced damage of the organ leading to its possible dysfunction. The toxic exposure ravaged the structure and impaired the functions of the gill of the animal which might restrict its proper gaseous exchange, filter feeding and elicitation of immune responses against pathogens.

OBJECTIVE

To investigate the association of serum uric acid (SUA) with arterial stiffness assessed by cardio-ankle vascular index (CAVI).

METHODS

We analyzed the cross-sectional data from 27,360 healthy Japanese subjects (12,910 males and 14,450 females) aged between 20 and 74 years without a past history of heart disease, stroke, hypertension, diabetes, nephritis or gout. We investigated whether SUA was independently associated with CAVI in a gender-specific manner.

RESULTS

BMI, CAVI, systolic/diastolic BP, GOT, GPT, γ-GTP, triglyceride (TG), creatinine and SUA were higher and HDL-C was lower in males than in females. Next, they were stratified by SUA into 3 groups: lower tertile (T1), middle tertile (T2) and upper tertile (T3) and by gender. CAVI increased progressive with increasing SUA tertile, after adjusting for age, BMI and systolic BP (sBP) identified in multiple regression analysis for CAVI. Multivariate analysis showed that the odds ratios (95% CI) relative to T1 for high CAVI (≥90(th) percentile) were 1.233 (0.928-1.638) in T2 and 1.352 (1.031-1.773) in T3 for males, and 1.133 (0.984-1.303) in T2 and 1.361 (1.098-1.687) in T3 for females, after adjusting for confounders. Furthermore, increase in adjusted CAVI was observed in a lower SUA range in females compared to that observed in males.

CONCLUSIONS

We demonstrated an independent correlation between SUA and CAVI, and observed gender difference in the SUA range for increase in CAVI. These results may suggest the need to set different target SUA levels for men and women in anti-hyperuricemic treatment for atherosclerosis prevention.

We reviewed retrospectively a cohort of 80 patients with hyperemesis gravidarum hospitalized between 1976 and 1986 for the presence of abnormal liver enzymes and ketonuria. Thirteen (16%) had abnormal liver enzymes, generally less than four times the upper limit of normal. In this group, hyperemesis gravidarum began at the 14th week of pregnancy as compared to the 6th week in the normal enzyme group (p less than 0.01). Both groups were similar with regard to age, number of children and pregnancies, and duration of vomiting. Ketonuria was significantly more severe (p less than 0.01) in the abnormal enzyme group, implying a more severe state of starvation and dehydration. The correlation coefficient between the degree of ketonuria and level of liver enzymes was low for alkaline phosphatase (r = 0.18), GPT (r = 0.15), and GOT (r = 0.28). The concept that dehydration and starvation are important factors for the induction of liver cell injury is supported by our data. Lack of correlation between the degree of ketonuria and liver enzyme levels is suggestive of other mechanisms (hormonal, genetic) that may interact to produce transaminasemia.

1. Serum enzymes activities of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT), after intraperitoneal injection of CdCl2 showed a maximum increase at 12 hours, contrary to the alkaline phosphatase (ALP) that showed a permanent decrease by that time. 2. Cadmium concentration in liver showed an increase at 6 and 12 hours, a decrease at 18, and a re-establishment to the initial values at 24 hours. 3. Liver microsomal membrane fluidity showed an increase at 6 hours followed by a decrease within 24 hours. Free radical generation was decreasing gradually up to 24 hours. 4. Gradually increasing changes were observed from the histological study.

The health effects of organophosphorus (OP) pesticides on cholinesterase (ChE) activities were assessed among 81 pest control workers from Northern Omo State Farm (Ethiopia), following the occupational use of Chlorpyrifos 25 and 48% ULV and Profenifos 250 EC/ULV. Plasma ChE (PChE) and erythrocyte ChE (AChE) activities were determined electrometrically before and after pesticide exposure. Plasma alkaline phosphatase (AP) and glutamic pyruvic transaminase (GPT) values were estimated colorimetrically. Risk factors of pesticide poisoning and related occupational factors were assessed following the WHO recommendations. The mean PChE and AChE activities determined after pesticide exposures were significantly lower than the pre-exposure values (P < 0.05); 16% and 40% of the pest control workers had PChE and AChE levels below 50% of the pre-exposure values, respectively. The mean plasma AP and GPT values were found to be within the recommended normal limits. No significant difference in either of the ChE activities was observed between the spray men and the pest assessors, although the former were believed to have frequent contact with the concentrated OP formulations. Risk factors of pesticide poisoning such as workers ignorance about the toxicity of pesticides, poor personal hygiene and total absence or improper use of personal protective devices were prevalent. Measures that should be considered to minimize the problem in the farm population are recommended.

Adult polycystic kidney disease (APKD) is a common genetic disorder that is inherited as an autosomal dominant trait. Recent reports show that, in some families, the APKD gene shows close genetic linkage to two chromosome 16 specific genetic markers. We have been conducting a genetic linkage study using 29 polymorphic isoenzyme and antigenic markers in 184 members of 12 APKD families. We present here the results of linkage analysis using three of these markers which have also been reported to be located on chromosome 16: phosphoglycolate phosphatase (PGP), glutamate pyruvate transaminase (GPT), and haptoglobin (HP). The results show that APKD is closely linked to the PGP locus on the short arm of chromosome 16 (16p13----p12), which is consistent with the previously reported linkage both to PGP and to the alpha globin locus. The genetic distance between PGP and APKD shows a maximum likelihood value of the recombination fraction at zero with a lod score of 5 X 5. There is no evidence of linkage between APKD and either GPT or HP. The PGP polymorphism potentially provides a useful predictive test to complement the use of alpha globin probes in genetic counselling. These tests should provide an efficient means of primary screening of family members at risk, as well as introducing the possibility of prenatal diagnosis.

Hyperlipidemia of hamsters was induced by high-fat/cholesterol diets formulated by the addition of coconut oil (CO), butter (BU), and flaxseed oil (FX). Lower (p < 0.05) serum lipids, liver size, and hepatic cholesterol and triacylglycerol contents were observed in the FX group compared to both CO and BU groups. The liver damage indices [glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) values] in the FX group were lower (p < 0.05) than those in the CO and BU groups, which may result from higher (p < 0.05) glutathione (GSH) levels and a tendency toward lower malondialdehyde (MDA) levels in livers. Besides, lower (p < 0.05) gene expression and activity of hepatic matrix metalloproteinases-9 (MMP-9) in the FX group were lower (p>> 0.05) compared to those in the CO and BU groups; however, no (p>> 0.05) differences in gene expression activities of hepatic MMP-2 were observed among treatments. Those beneficial effects could explain the attenuation of FX on nonalcoholic fatty liver (NAFL) induced by a high-fat/cholesterol dietary habit.

An easy to apply culture technique is presented that protects a monolayer configuration of liver cells within an extracellular matrix. The Immobilising Gel (IG)-Technique not only preserves hepatocyte morphology and supports a variety of differentiated cell functions over long term periods, but also offers higher resistance of IG-culture systems against shear forces of fluids in a hybrid reactor device, as compared to other culture techniques. Human hepatocyte cultures in IG-Technique: DNA-normalised levels for the total production of cholinesterase, albumin, urea and lactate remained high throughout the investigational period (50 days). Glutamic-Pyruvic-Transaminase (GPT) release decreased after peak values during early culture adaptation. Electron Microscopic (EM) findings after the shear forces experiment revealed undisturbed subcellular structures and a preserved intercellular morphology, including bile canaliculi and desmosomes. We conclude that the IG-technique is of considerable advantage as compared to other culture systems, especially in the field of dynamic applications, e.g. hybrid reactors for artificial organ development.

To investigate the importance of the cadmium (Cd) exposure condition in the evaluation of toxic effect on renal function and bone metabolism, six groups of Male Wistar rats were given Cd at respective daily doses of 2, 5, 10, 20, 30 and 60 mgCd/kg (as CdCl2) via a gastric tube for 6 consecutive days a week for 60 weeks. In the groups given a low Cd dose (2, 5 and 10 mgCd/kg), relatively more Cd accumulated in the kidney without liver damage than in the liver. In the high Cd dose groups (20, 30 and 60 mgCd/kg), on the other hand, more Cd accumulated in the liver than in the kidney. The daily intake of Cd dose from the intestinal tract in each experimental group was deduced to be about 0.36%-0.54% of the cumulative dose of oral Cd administration. The daily intake of Cd into the body was estimated as 7, 22, 40, 100, 120, 260 microgCd/kg/day in the experimental groups of 2, 5, 10, 20, 30 and 60 mgCd/kg/day, respectively. Increase of plasma enzyme activity (GOT, GPT) and of urinary enzyme excretion (NAG, AAP, GST), reflecting hepatic damage and renal dysfunction, was found in the high Cd dose groups (30 and 60 mgCd/kg) from the 5th week. Non-CdMT concentration in the kidney was also significantly high in the high Cd dose groups. In the low Cd dose groups (2 and 5 mgCd/kg), although the renal Cd concentration was higher than that of the high Cd dose groups, prominent renal dysfunction and hepatic damage were not observed. Regeneration, vacuolization, and eosinophilic bodies in proximal tubular tissue were mainly observed in the groups subjected to 20, 30 and 60 mgCd/kg administration. Very slight regeneration was also observed in the renal proximal tubular tissue at the 30th week for the 5 mgCd/kg and 10 mgCd/kg groups, and at the 60th week for the 2 mgCd/kg group. Remarkable decrease of bone mineral density at the midpoint of the femur was found in the high Cd dose groups. Also, the decrease in bone mineral density was observed before or after the manifestation of the renal dysfunction, depending on the dose and the duration of Cd administration. Urinary excretion of Pyr, DPyr, and Ca increased and plasma BGP decreased in the higher Cd dose groups. Osteoid volume in the femur tissue was not increased significantly by Cd exposure. Based on these results, it was suggested that Cd exposure caused osteoporotic change. The results of the present study suggested that the toxic effect of Cd on renal function and that on bone metabolism were caused at different times and that renal Cd concentration after long-term oral Cd administration depended on the dose and the duration of Cd exposure.

BACKGROUND

To evaluate the prevalence of the accessory left hepatic artery (ALHA; defined as a vessel arising from the left gastric artery, which, together with a typical left hepatic artery, supplies blood to the left lobe of the liver) and its short-term clinical implications in patients undergoing radical gastrectomy for gastric cancer.

METHODS

Clinical data of 1173 patients with gastric cancer who underwent laparoscopy-assisted radical gastrectomy were retrospectively analyzed. Groups of patients with and without ALHA were compared to identify differences in intraoperative and postoperative variables and changes in liver function.

RESULTS

Of the 1173 patients, 135 (11.5%) had an ALHA and 1038 (88.5%) did not. There were no significant between-group differences in clinicopathological and intraoperative characteristics, postoperative recovery, and morbidity and mortality rates (P>0.05 each). None of the patients had postoperative symptoms associated with impaired liver function. Glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT) and total bilirubin (TBIL) concentrations were similar preoperatively. TBIL concentrations on postoperative days 1, 3, and 7 were similar (P>0.05), while GOT and GPT activities were higher in the ALHA than in the non-ALHA group on days 1 and 7 (P<0.05), with all three markers similar in the two groups on day 14. In patients without chronic liver disease (CLD), GOT, GPT and TBIL concentrations were similar in patients with and without ALHA; whereas, in patients with CLD, GOT and GPT concentrations on days 1 and 3 and GOT on day 7 were higher in patients with than without ALHA.

CONCLUSIONS

ALHA is a common anomaly that was found in 11.5% of patients. It can be safely severed during radical gastrectomy in patients without CLD, but should be left intact in patients with CLD to prevent liver dysfunction. If severed in the latter, the patient should be monitored and liver-protecting therapy may be necessary.

Using primary porcine hepatocytes, artificial extracorporeal liver support (AEL) is a therapy that carries out the liver functions of liver failure patients until their own organs have been regenerated or until whole organ transplantation. Significant variation exists with regard to current bioreactor designs for AEL, and they may not reflect the in vivo architecture of the liver since each individual hepatocyte has its own direct contact with blood plasma for oxygen and nutrient supply and detoxification. The present study, based on our flat membrane bioreactor (FMB), aimed at in vivo liver architecture and to meet authentic clinical levels of human plasma exposure. Since many existing preclinical AELs are based on commercial culture medium with or without nonhuman serum, they may not authentically reflect the clinical situation in human patients, and little research has been done on human plasma exposure in in vitro culture-based bioreactors. To address this situation, herein we examined liver-specific functions such as albumin secretion, urea synthesis, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), cell membrane stability by lactate dehydrogenase (LDH) test and ammonia clearance by using human plasma and serum-free medium in long-term culture of primary porcine hepatocytes to show the potential of our clinically relevant FMB. We observed that the organotypical double-gel (DG) culture is superior to conventional collagen-coated single-gel (SG) cultures. The performance of liver-specific functions by the FMB has long-term stability with intact cell morphology for up to 20 days under both plasma exposure and serum-free media. Our three focus points (long-term culture that correlates with the generation time of spontaneous regeneration, high-density culture, organotypical culture model using human plasma) may provide valuable clinical clues for AEL.

Adriamycin, an anticancer drug, caused dramatic increases in the serum lipid levels of rats fed a high-cholesterol diet. Male Lewis inbred rats were fed a basal or 1.5% cholesterol diet containing 0.5% cholic acid for 8 weeks. The rats were injected with adriamycin in doses of 1.5 mg/kg body weight, twice a week, and 6.0 mg/kg body weight, every other week. The serum lipid peroxide level gradually rose in adriamycin-treated rats, reaching a four-fold level at the end of the experiment. Cholesterol feeding, however, had a lowering effect on the lipid peroxide level. Adriamycin treatment or cholesterol feeding moderately elevated serum lipid levels, but their combination exerted a synergistic effect. In rats injected with a large dose of adriamycin and fed a high-cholesterol diet, the serum cholesterol, triglyceride and phospholipid levels strikingly increased by approx. 2000, 1500 and 1300 mg/100 ml, respectively. However, the ester ratio of cholesterol remained almost constant. Furthermore, serum GOT, GPT and ALP activities were only slightly different from the control values. Adriamycin treatment produced severe hypoalbuminemia. Ascites was also observed in rats given a large dose of adriamycin. The present findings indicate that the hyperlipidemia we observed may basically result from adriamycin-induced nephrosis and can be markedly enhanced when rats are fed a high-cholesterol diet. In spite of remarkably high levels of serum lipids and lipid peroxides, the aortic cholesterol level increased only slightly.

Sixteen barrows (Duroc x Landrace x Yorkshire) were randomly divided into two groups, each consisting eight pigs. The groups received the same basal diet supplemented with 0 and 400 mg/kg fluoride, respectively. Histological examinations, including in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), Haematoxylin and Eosin staining (HE) and transmission electron microscopy observation, found apoptotic hepatocytes 50 days after additional 400 mg/kg fluoride treatment. The obvious DNA ladder and the significantly increased both hepatic caspase-9 and caspase-3 activity indicated that fluoride induced caspase-dependent apoptosis in vivo. In addition, serum glutamate pyruvate transaminase (GPT) activity and hepatic lipid peroxides (LPO) concentration was significantly increased. The activity of serum glutamate oxaloacetate transaminase (GOT) showed an increased trend. The results suggest that fluoride induces apoptosis by elevating the oxidative stress-induced lipid peroxidation, causing mitochondrial dysfunction and further activating caspase-9 and caspase-3.

Effects of ascorbic acid supplementation on the activity of acid phosphatase (ACP), alkaline phosphatase (ALP), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) on liver, kidney and serum in cyclophosphamide-treated female virgin rats were investigated. Oral administration of cyclophosphamide at the dose of 5 mg/kg body weight/day for 12 days resulted in a significant elevation in ACP and ALP activities in liver, kidney and serum. Ascorbic acid supplementation at the dose of 25 mg/kg body weight/day showed a significant protection in the activity of ACP in liver, kidney and serum, but only in ALP activity in kidney. ALP activities in liver and serum were not restored to control level by ascorbic acid supplementation. Activities of GOT and GPT were elevated significantly in liver, kidney and serum after cyclophosphamide treatment, and were protected and restored to control level by ascorbic acid supplementation.

The cytotoxic and genotoxic effects of chronic feeding of the azo-dye p-dimethylaminoazobenzene (p-DAB) during 7, 15, 30, 60, 90 and 120 days have been assessed in mice. The endpoints used for genotoxic analysis were chromosome aberrations (CA), micronuclei (MN) and mitotic index (MI) in bone-marrow cells, and sperm-head abnormality (SHA) in male gonads. The activities of marker enzymes for toxicity, such as glutamate oxalo-acetate transaminase (GOT), glutamate pyruvate transaminase (GPT), acid phosphatase (ACP) and alkaline phosphatase (ALKP) were also assayed periodically, as was lipid peroxidation (LPO). Chronic feeding of p-DAB produced increased numbers of chromosome aberrations, nuclear anomalies and sperm-head abnormalities, as compared with normal untreated controls, generally in a time-dependent manner until 60 days, after which the anomalies persisted, but rather erratically. However, although there was some noticeable modulation in enzyme activities in the corresponding p-DAB-fed mice as well, these were not strictly time-dependent.

BACKGROUND

Dietary polyunsaturated fats increase liver injury in response to ethanol feeding. We evaluated the effect of dietary corn oil (CO), olive oil (OO), and beef tallow (BT) on fatty acid composition of liver microsomal membrane and acute acetaminophen hepatotoxicity.

METHODS

Male Sprague-Dawley rats were fed 15% (wt/wt) CO, OO or BT for 6 weeks. After treatment with acetaminophen (600 mg/kg), samples of plasma and liver were taken for analyses of the fatty acid composition and toxicity.

RESULTS

Treatment with acetaminophen significantly elevated levels of plasma GOT and GPT as well as hepatic TBARS but reduced hepatic GSH levels in CO compared to OO and BT groups. Acetaminophen significantly induced protein expression of cytochrome P450 2E1 in the CO group. In comparison with the CO diet, lower levels of linoleic acid, higher levels of oleic acids and therefore much lower ratios of linoleic to oleic acid were detected in rats fed OO and BT diets.

CONCLUSIONS

Dietary OO and BT produces similar liver microsomal fatty acid composition and may account for less severe liver injury after acetaminophen treatment compared to animals fed diets with CO rich in linoleic acid. These findings imply that types of dietary fat may be important in the nutritional management of drug-induced hepatotoxicity.

The activity of the enzymes G6PDH, 6PGDH, GAPDH, LDH, CS, MDH, NADP-linked ICDH, GOT, GPT, and GLDH was tested in different stages of developing eggs and in just hatched larvae of crickets. A malic synthase could not be found. The enzymatic pattern changes considerably during this period. Considering this pattern, and especially the quotient (GAPDH)/CS, it seems justified to state that, up to the formation of the germ band, the energy is derived mainly from oxidation of glucose in the citric acid cycle. Later on, lipids substitute partly for glucose. Anaerobic energy production seems to be limited to the stage of the dorsal closure. By inhibiting the formation of the germ band, the activity of GAPDH, and CS is not changed significantly. The rise in activity of G6PDH is correlated with the increased rate of r-RNA synthesis. The increase of activity of MDH and NADP-linked ICDH corresponds to the differentiation of the germ band. These enzymes, together with GOT, GPT, and GLDH should be involved in the synthesis of amino acids from carbohydrates during the later part of development. In the hatched larvae the activity of all enzymes has risen considerably. This stage is characterized by the fact that G6PDH, 6PGDH, GAPDH, LDH, CS, and NADP-linked ICDH display the same activity.

The relationship between the GOT/GPT ratio in nonviral liver disorders and underlying physical condition and life-style were evaluated. The subjects were 12,808 male railway company workers who underwent an annual health checkup. Nonviral liver disorders were defined as elevated transaminases (GOT>> 76 IU/liter or GPT>> 86 IU/liter, while negative for hepatitis B and C markers (282 cases). Controls were 9,783 males with normal findings for GOT, GPT, and y-GTP. By logistic regression analysis, GOT-dominant liver disorders were significantly related to alcohol consumption, hypertriglyceridemia, and diabetes mellitus. They were still significant on multivariate analysis. GPT-dominant liver disorders were significantly related to obesity, less exercise, hypercholesterolemia, and hypertriglyceridemia. Obesity and hypercholesterolemia were significant on multivariate analysis. In conclusion, the relationship between hypertriglyceridemia or diabetes mellitus and GOT-dominant disorders, which was not explained empirically, could indicate another pathogenesis for nonviral liver disorders, such as underlying insulin resistance.

We investigated the synergistic effect of pidotimod and red ginseng acidic polysaccharide (RGAP) from Panax ginseng C.A. Meyer on humoral immune response challenged by lipopolysaccharide (LPS) and sheep red blood cells (SRBC) in immunosuppressed mice. Combined treatment with pidotimod and RGAP significantly increased the number of plaque-forming cells in the spleen in response to both LPS and SRBC, while treatment with either pidotimod or RGAP individually had no such effect. IgG levels in serum were augmented for secondary responses to SRBC in co-treated mice, but not in mice treated with either drug alone. Microscopic studies revealed that architecture of the spleen, thymus, and lymph nodes was conserved. GPT and creatinine in serum as indicators of hepatic and renal functions showed no difference compared to the control group. These results indicate that combined treatment with pidotimod and RGAP has an immunostimulatory effect in a synergistic manner on antibody response to challenge with LPS and SRBC without toxic changes.

Peripheral neuropathy can arise from various mechanisms during hepatitis C virus (HCV) infection, mainly involving associated mixed cryoglobulinemia. The frequency of demyelinating polyneuropathy is probably underestimated in these patients. We report two cases of demyelinating polyneuropathy in HCV-infected patients. The first case concerned a 76-year-old woman followed for hepatitis C associated with a mixed cryoglobulinemia (type II), who developed a chronic progressive distal motor weakness and sensory disturbances concomitant with a raise in serum aspartate aminotransferase (GOT/AST) and alanine aminotransferase (GPT/ALT) levels. Other laboratory studies were normal except for a decrease in the hemolytic fraction of complement to 75 IU (n = 400-520). The second case was a 68-year-old woman followed for hepatitis C associated with a mixed cryoglobulinemia (type II), who had sensory disturbances in the lower limbs. Laboratory studies were otherwise unremarkable. Cerebrospinal fluid studies showed a normal protein content without pleocytosis in both patients. In both cases nerve conduction studies were suggestive of a mixed axonal and demyelinating sensorimotor neuropathy. Sural nerve biopsy showed segmental demyelination and severe loss of large myelinated fibers as well as some onion bulb formation in both cases. The two patients subsequently improved, the first with an antiviral treatment and the second with oral steroids.

Gene frequencies of common and rare <em>GPT</em> alleles derived from an investigation of 1139 unrelated, healthy individuals from southwestern Germany are given. <em>GPT</em> typing was performed by means of horizontal starch gel electrophoresis in a Tris-histidine x HCl buffer system. In addition, a new electrophoretic variant, <em>GPT</em>9, is described. The frequencies of the <em>GPT</em> alleles observed were calculated as: <em>GPT</em>1, 0.4987; <em>GPT</em>2, 0.4686; <em>GPT</em>1M, 0.022; <em>GPT</em>0, 0.005; <em>GPT</em>3, 0.0022; <em>GPT</em>4, 0.0025; <em>GPT</em>8, 0.0005; <em>GPT</em>9, 0.0005.

BACKGROUND

Because noble dental casting alloys for metal ceramic restorations have a wide range of mechanical properties, knowledge of these properties is needed for rational alloy selection in different clinical situations where cast metal restorations are indicated.

OBJECTIVE

The purpose of this study was to compare the mechanical properties and examine both the fracture and polished surfaces of 6 noble casting alloys that span many currently marketed systems. Five alloys were designed for metal ceramic restorations, and a sixth Type GPT has Type IV alloy for fixed prosthodontics (Maxigold KF) was included for comparison.

METHODS

Specimens (n=6) meeting dimensional requirements for ISO Standards 9693 and 8891 were loaded to failure in tension using a universal testing machine at a crosshead speed of 2 mm/min. Values of 0.1% and 0.2% yield strength, ultimate tensile strength, elastic modulus, and percentage elongation were obtained. Statistical comparisons of the alloy mechanical properties were made using 1-way ANOVA and the REGW multiple-range test (α=.05). Following fracture surface characterization using scanning electron microscopy (SEM), specimens were embedded in epoxy resin, polished, and again, examined with the SEM.

RESULTS

When the multiple comparisons were considered, there were generally no significant differences in the elastic modulus, 0.1% and 0.2% offset yield strength, and ultimate tensile strength for the d.SIGN 91 (Au-Pd), d.SIGN 59 (Pd-Ag), Capricorn 15 (Pd-Ag-Au) and Maxigold KF (Au-Ag-Pd) alloys, except that the ultimate tensile strength was significantly lower (P<.05) for Maxigold KF than these other 3 alloys. These 4 mechanical properties were generally significantly lower (P<.05) for Aquarius XH (Au-Pt-Pd) and Brite Gold XH (Au-Pt). The d.SIGN 59 (14.6%) and Capricorn 15 (13.8%) alloys had the highest values of mean percentage elongation, which were not significantly different. Aquarius XH (6.0%) and Maxigold KF (4.2%) had the lower mean values of percentage elongation, which were also not significantly different. The polished and etched surfaces for all alloys revealed equiaxed, fine-grain microstructures, and all fracture surfaces contained casting porosity. Incomplete solidification suggestive of dendritic structures was observed for some alloys. Fracture surfaces were complex, with characteristic features of both brittle and ductile fracture. Precipitate particles on the fracture surfaces indicated the multi-phase character of the alloys.

CONCLUSIONS

For the important mechanical property of yield strength, there were generally no significant differences among the Au-Pd, Pd-Ag, Pd-Ag-Au and Au-Ag-Pd alloys. Wide variation was found in percentage elongation, with the Pd-Ag and Pd-Ag-Au alloys having the highest values and the Au-Pd-Pt and Au-Ag-Pd alloys having the lowest values.

We assess the bioaccumulation of metals (Pb, Hg, Cd, Fe, Mg, Zn, Cu, Mn, Mo, Cr) and effects of landfill leachates on morphological (RI, relative weights), plasma (GPT, GOT, creatinine), and genotoxic (MNT) parameters in wood mice, Apodemus sylvaticus, inhabiting close the Garraf landfill site (NE Spain). Due to the high age- and sex-dependent variation in wild populations, we also studied the effect of these biotic factors on the parameters studied. Wood mice from the landfill site, sited in a partially protected area, showed more Cd, Fe, Zn, Cu, Mn, Mo, and Cr than specimens from the reference site. Moreover, mice near the landfill registered low RI and high relative renal weight, GPT, and MN frequency, which indicate that the landfill affects the health of wild mice. In contrast to sympatric shrews from a previous study, wood mice showed lower bioaccumulation of metals and lower variation caused by biotic factors. Moreover, the morphological and physiological alterations demonstrated that they were also more sensitive at environmental pollution. Given the contribution of small mammals to ecosystem function and the scarce ecotoxicological data on the effects of landfill pollution on wild terrestrial mammals, we consider that our study can be used to improve the management of this protected area.