Lipid biosynthesis within the chloroplast, or more generally plastids, was conventionally called "prokaryotic pathway," which produces glycerolipids bearing C18 acids at the sn-1 position and C16 acids at the sn-2 position, as in cyanobacteria such as Anabaena and Synechocystis. This positional specificity is determined during the synthesis of phosphatidate, which is a precursor to diacylglycerol, the acceptor of galactose for the synthesis of galactolipids. The first acylation at sn-1 is catalyzed by glycerol-3-phosphate acyltransferase (GPAT or GPT), whereas the second acylation at sn-2 is performed by lysophosphatidate acyltransferase (LPAAT, AGPAT, or PlsC). Here we present comprehensive phylogenomic analysis of the origins of various acyltransferases involved in the synthesis of phosphatidate, as well as phosphatidate phosphatases in the chloroplasts. The results showed that the enzymes involved in the two steps of acylation in cyanobacteria and chloroplasts are entirely phylogenetically unrelated despite a previous report stating that the chloroplast LPAAT (ATS2) and cyanobacterial PlsC were sister groups. Phosphatidate phosphatases were separated into eukaryotic and prokaryotic clades, and the chloroplast enzymes were not of cyanobacterial origin, in contrast with another previous report. These results indicate that the lipid biosynthetic pathway in the chloroplasts or plastids did not originate from the cyanobacterial endosymbiont and is not "prokaryotic" in the context of endosymbiotic theory of plastid origin. This is another line of evidence for the discontinuity of plastids and cyanobacteria, which has been suggested in the glycolipid biosynthesis.

In this study, the protective effects of a carboxymethyl polysaccharide CMP33 from Poria cocos against inflammatory bowel disease (IBD) were investigated using TNBS-induced colitis in mice. The results showed that CMP33 markedly ameliorated the severity of colitis, including a 2-fold decrease in the mortality rate, a 50% decrease in disease activity index, and a 36%-44% decrease in macro- or microscopic histopathological score, compared with TNBS administration. Moreover, CMP33 decreased the levels of pro-inflammatory cytokines and increased the levels of anti-inflammatory cytokines in the colon tissue and serum of colitic mice. Using iTRAQ-coupled- nano-HPLC-MS/MS-based proteomics, the protein profiles after TNBS, high- or low-dose CMP33 and salazosulfapyridine (SASP) treatments were compared and many differentially expressed proteins were identified. Among them, 7 proteins (Hmgcs2, Fabp2, Hp, B4galnt2, B3gnt6, Sap and Ca1) were proposed to be the common targeting protein group (TPG) of CMP33 and drug SASP. Particularly, some targeting proteins were CMP33-dose-specific: high-dose-specific TPG (Mtco3, Gal-6, Mptx, S100 g and Hpx) and low-dose-specific TPG (Zg16, Hexb, Insl5, Cept1, Hspb6 and Ifi27l2b), suggesting the complex acting mechanism of CMP33. GC-TOF-MS-based metabolomics revealed that oleic acid and dihydrotestosterone could be the common targets of CMP33 and SASP. By integrative analysis of proteomics and metabolomics, key protein-metabolite pathways (PMP) were identified, PMP for high-dose: 2-hydroxybutyric acid - (GPT, GGH) - glutathione - ALB - testosterone - TTR - dihydrotestosterone; PMP for low-dose: (PYY, FABP2, HMGCS2) - oleic acid - TTR - dihydrotestosterone. In total, these results demonstrated the protective effects of CMP33 against IBD in mice through the potential TPG and PMP.

BACKGROUND

Geniposidic acid (GPA) is the main constituent of Gardenia jasminoides Ellis (Rubiaceae), which has long been used to treat inflammation, jaundice and hepatic disorders. The cholagogic effect of Gardenia jasminoides Ellis (Rubiaceae) and GPA have been widely reported, but the underlying occurrence mechanism remains unclear.

OBJECTIVE

This investigation was designed to evaluate the hepatoprotection effect and potential mechanisms of GPA derived from Gardenia jasminoides Ellis (Rubiaceae) on fighting against α-naphthylisothiocyanate (ANIT) caused liver injury with acute intrahepatic cholestasis.

METHODS

Sprague-Dawley (SD) rats were intragastrically (i.g.) administered with the GPA (100, 50 and 25mg/kg B.W. every 24h) for seven consecutive days, and then they were treated with ANIT (i.g. 65mg/kg once in the 5th day) which induced liver injury with acute intrahepatic cholestasis. Serum and bile biochemical analysis, bile flow rate and liver histopathology were measured to evaluate the protective effect of GPA fight against ANIT treatment. The protein and mRNA expression levels of farnesoid X receptor (Fxr), bile-salt export pump (Bsep), multidrug resistance associated protein2 (Mrp2), were evaluated to study the effect of liver protection about GPA against ANIT induced hepatotoxicity and underlying mechanisms.

RESULTS

Some abnormalities were observed on ANIT treated rats including weight loss, reduced food intake and hair turned yellow. Obtained results demonstrated that at dose 100 and 50mg/kg B.W. (P<0.01) and 25mg/kg B.W. (P<0.05) of GPA pretreated dramatically prevented ANIT induced decreased in bile flow rate. Compared with ANIT treated group, the results of bile biochemical parameters about total bile acid (TBA) was increased by GPA at groups with any dose (P<0.01), glutathione (GSH) was increased significantly at high dose (P<0.01) and medium dose (P<0.05), total bilirubin (TB) was increased at high and medium dose (P<0.05), direct bilirubin (DB) was only increased at high dose (P<0.01). Serum levels of glutamic-Oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), γ-glutamyltranspeptidase (γ-GT), TB, DB and TBA in comparison with ANIT treated group (P<0.01) were reduced by GPA (between 100 and 50mg/kg B.W.) pretreatment. Histopathology of the liver tissue showed that pathological damages and hepatic portal area filled with bile were relieved after GPA pretreatment compared with ANIT treated group. The protein and mRNA expression of Fxr, Bsep and Mrp2 were decreased in ANIT treated group. On the contrary, the protein and mRNA of Fxr, Bsep and Mrp2 were up regulated significantly pretreatment by GPA at dose of high and medium groups. On protein level of Bsep and Mrp2 the result shown no statistical difference in GPA (25mg/kg B.W.), but it was not same shown in mRNA level.

CONCLUSIONS

The results of this investigation have demonstrated that the GPA exerts a dose dependent hepatoprotection effect on ANIT induced liver damage with acute intrahepatic cholestasis in rats, which may due to Fxr mediated regulation of bile transporters like Bsep and Mrp2.

Toxicity of the cells of a newly established axenic Microcystis aeruginosa K-139 strain to mice was studied. LD50 of the cells harvested in the mid-log phase was 7.3 mg/kg. The organs of acute dead mice were examined histopathologically. The blood congestion and necrosis of the parenchymal cells around the central veins in the liver were observed, but other organs seemed to be normal. The liver damage was confirmed by the tests of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) activities in the sera of the mice after the injection with the K-139 cells. Furthermore, the K-139 cells were capable of inducing interleukin 1 (IL-1) production by peritoneal macrophages in vitro.

Glioblastoma multiforme (GBM) represents an aggressive tumor type with poor prognosis. The majority of GBM patients cannot be cured. There is high willingness among patients for the compassionate use of non-approved medications, which might occasionally lead to profound toxicity. A 65-year-old patient with glioblastoma multiforme (GBM) has been treated with radiochemotherapy including temozolomide (TMZ) after surgery. The treatment outcome was evaluated as stable disease with a tendency to slow tumor progression. In addition to standard medication (ondansetron, valproic acid, levetiracetam, lorazepam, clobazam), the patient took the antimalarial drug artesunate (ART) and a decoction of Chinese herbs (Coptis chinensis, Siegesbeckia orientalis, Artemisia scoparia, Dictamnus dasycarpus). In consequence, the clinical status deteriorated. Elevated liver enzymes were noted with peak values of 238 U/L (GPT/ALAT), 226 U/L (GOT/ASAT), and 347 U/L (γ-GT), respectively. After cessation of ART and Chinese herbs, the values returned back to normal and the patient felt well again. In the literature, hepatotoxicity is well documented for TMZ, but is very rare for ART. Among the Chinese herbs used, Dictamnus dasycarpus has been reported to induce liver injury. Additional medication included valproic acid and levetiracetam, which are also reported to exert hepatotoxicity. While all drugs alone may bear a minor risk for hepatotoxicity, the combination treatment might have caused increased liver enzyme activities. It can be speculated that the combination of these drugs caused liver injury. We conclude that the compassionate use of ART and Chinese herbs is not recommended during standard radiochemotherapy with TMZ for GBM.

Diospyrin, a bisnaphthoquinonoid plant product, shows inhibitory activity against murine tumour in vivo and human cancer cell lines in vitro. Efforts have further been made to obtain synthetic derivatives of diospyrin with the objective of improved therapeutic effects. With the goal to reduce the toxicity towards normal cells and enhance the efficacy to tumour cells, diospyrin was encapsulated in liposomal vesicle and its antitumour potential was observed on the growth of Ehrlich ascites tumour in Swiss mice. It was found that the longevity of the tumour-bearing mice was significantly enhanced by treatment with liposomal diospyrin as compared with the free drug. Biochemical assay of liver function enzymes, viz. LDH, AP, GOT and GPT in blood serum of the tumour-bearing mice showed substantial alterations in the activity of these enzymes. These parameters were, however, restored to near normal level when the drug treatment was given encapsulated in a liposome. Histopathological studies on the liver tissues indicated a near normal pathological status in the treated animals despite being challenged by tumour cells. This study on diospyrin has shown, for the first time, an enhancement of its antitumour effect in vivo through liposomal encapsulation.

The hepatoprotective activity of aqueous-methanolic extract of Cichorium intybus seeds was investigated against acetaminophen and CCl(4)-induced hepatic damage. Acetaminophen produced 100% mortality at the dose of 1 g/kg in mice while pretreatment of animals with plant extract (500mg/kg) reduced the death rate to 30%. Acetaminophen at the dose of 640 mg/kg produced liver damage in rats as manifested by the significant (P < 0.01) rise in serum levels of alkaline phosphatase (ALP), GOT and GPT to 393 ± 28, 767 ± 215 and 692 ± 191 IU/L (n = 10) respectively, compared to respective control values of 198 ± 15, 76 ± 07 and 39 ± 09. Pretreatment of rats with plant extract (500 mg/kg) significantly lowered (P < 0.01), the respective serum ALP, GOT and GPT levels to 228 ± 16, 68 ± 10 and 41 ± 08. Similarly, a hepatotoxic dose of CCl(4) (1.5 mL/kg; orally) significantly raised (P < 0.01), the serum ALP, GOT and GPT levels to 312 ± 20, 503 ± 98 and 407 ± 109 IU/L (n = 10) respectively, compared to respective control values of 215 ± 16, 79 ± 18 and 49 ± 10. The same dose of plant extract (500 mg/kg) was able to prevent significantly (P < 0.05) the CCl(4)-induced rise in serum enzymes and the estimated values of ALP, GOT and GPT were 222 ± 27, 114 ± 23 and 68 ± 14 respectively. Moreover, it prevented CCl(4)-induced prolongation in pentobarbital sleeping time confirming hepatoprotectivity and validates the folkloric uses of this plant in liver damage.

Enzyme activities and gene expression of a number of innate immune parameters in the serum, mucus and skin of Atlantic salmon (Salmo salar) were investigated after challenge with a pathogenic strain of Aeromonas salmonicida (A. salmonicida). Fish were injected in the dorsal muscle with either 100 μl bacterium solution, about 3.05 × 10(7) CFU/ml A. salmonicida, or 100 μl 0.9% NaCl (as control group) and tissue samples were collected at days 0, 2, 4 and 6 post-injection. Lysozyme (LSZ) and alkaline phosphatase (AKP) activities in serum, mucus and skin, and LSZ and AKP mRNA expression in skin of the challenged fish were higher than those of the control at most of the experimental time, with significant differences at several time points (P < 0.05), indicating the involvement of LSZ and AKP in the innate immunity of Atlantic salmon to A. salmonicida. Superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities in mucus and skin, along with the SOD, POD and CAT mRNA expression in skin significantly decreased at day 4 and 6, indicating the decreased antioxidant capacity of the challenged fish. Glutamate pyruvate transaminase (GPT) and glutamic oxalacetic transaminase (GOT) activities in serum, mucus and skin of the challenged group were all higher than those of the control after the injection, and at several time points significant differences were found between the two groups, suggesting organs of fish were impaired after the pathogen infection. The changes of the GPT and GOT activities could be used as potential biomarkers for the impairment of physiological functions caused by the pathogen infection. Identified biomarkers of the immune responses will contribute to the early-warning system of the disease. So this study will not only provide a theoretical basis for vaccine development, but also provide basic data for the establishment of early warning systems for diseases caused by A. salmonicida in Atlantic salmon rearing.

Citrinin (CTN) is a food-contaminating mycotoxin that efficiently induces renal tumors in rats. However, the modes of carcinogenic action are still unknown, preventing assessment of the risks of CTN in humans. In the present study, the proliferative effects of CTN and its causal factors were investigated in the kidneys of gpt delta rats. In addition, three in vivo genotoxicity assays (reporter gene mutation using gpt delta rats and comet and micronucleus assays using F344 rats) were performed to clarify whether CTN was genotoxic in vivo. CTN was administrated at 20 and 40mg/kg/day, the higher dose being the maximal tolerated dose and a nearly carcinogenic dose. In the kidney cortex of gpt delta rats, significant increases in the labeling indices of proliferating cell nuclear antigen (PCNA)-positive cells were observed at all doses of CTN. Increases in the mRNA expression levels of Ccna2, Ccnb1, Ccne1, and its transcription factor E2f1 were also detected, suggesting induction of cell cycle progression at all tested doses of CTN. However, histopathological changes were found only in rats treated with the higher dose of CTN, which was consistent with increases in the mRNA expression levels of mitogenic factors associated with tissue damage/regeneration, such as Hgf and Lcn2, at the same dose. Thus, the proliferative effects of CTN may result not only from compensatory reactions, but also from direct mitogenic action. Western blot analysis showed that ERK phosphorylation was increased at all doses, implying that cell cycle progression may be mediated by activation of the ERK pathway. On the other hand, in vivo genotoxicity analyses were negative, implying that CTN did not have the potential for inducing DNA damage, gene mutations, or chromosomal aberrations. The overall data clearly demonstrated the molecular events underlying CTN-induced cell cycle progression, which could be helpful to understand CTN-induced renal carcinogenesis.

Impaired macroautophagy/autophagy has been implicated in experimental and human nonalcoholic steatohepatitis (NASH). However, the mechanism underlying autophagy dysregulation in NASH is largely unknown. Here, we investigated the role and mechanism of TXNIP/VDUP1 (thioredoxin interacting protein), a key mediator of cellular stress responses, in the pathogenesis of NASH. Hepatic TXNIP expression was upregulated in nonalcoholic fatty liver disease (NAFLD) patients and in methionine choline-deficient (MCD) diet-fed mice, as well as in palmitic acid (PA)-treated hepatocytes. Upregulation of hepatic TXNIP was positively correlated with impaired autophagy, as evidenced by a decreased number of MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 beta) puncta and increased SQSTM1/p62 (sequestosome 1) expression. Deletion of the Txnip gene enhanced hepatic steatosis, inflammation, and fibrosis, accompanied by impaired autophagy and fatty acid oxidation (FAO) in MCD diet-fed mice. Mechanistically, TXNIP directly interacted with and positively regulated p-PRKAA, leading to inactivation of MTOR (mechanistic target of rapamycin kinase) complex 1 (MTORC1) and nuclear translocation of TFEB (transcription factor EB), which in turn promoted autophagy. Inhibition of MTORC1 by rapamycin induced autophagy and increased the expression levels of FAO-related genes and concomitantly attenuated lipid accumulation in PA-treated txnip-knockout (KO) hepatocytes, which was further abolished by silencing of Atg7. Rapamycin treatment also attenuated MCD diet-induced steatosis, inflammation, and fibrosis with increased TFEB nuclear translocation and restored FAO in txnip-KO mice. Our findings suggest that elevated TXNIP ameliorates steatohepatitis by interacting with PRKAA and thereby inducing autophagy and FAO. Targeting TXNIP may be a potential therapeutic approach for NASH. Abbreviations: ACOX1: acyl-Coenzyme A oxidase 1, palmitoyl; ACSL1: acyl-CoA synthetase long-chain family member 1; ACTA2/α-SMA: actin, alpha 2, smooth muscle, aorta; ACTB: actin beta; ADGRE1/F4/80: adhesion G protein-coupled receptor E1; AMPK: AMP-activated protein kinase; ATG: autophagy-related; BafA1: bafilomycin A1; COL1A1/Col1α1: collagen, type I, alpha 1; CPT1A: carnitine palmitoyltransferase 1a, liver; CQ: chloroquine; DGAT1: diacylglycerol O-acyltransferase 1; DGAT2: diacylglycerol O-acyltransferase 2; ECI2/Peci: enoyl-Coenzyme A isomerase 2; EHHADH: enoyl-Coenzyme A, hydratase/3-hydroxyacyl Coenzyme A dehydrogenase; FAO: fatty acid oxidation; FASN: fatty acid synthase; FFA: free fatty acids; GFP: green fluorescent protein; GK/GYK: glycerol kinase; GOT1/AST: glutamic-oxaloacetic transaminase 1, soluble; GPAM: glycerol-3-phosphate acyltransferase, mitochondrial; GPT/ALT: glutamic pyruvic transaminase, soluble; H&E: hematoxylin and eosin; IL1B/IL-1β: interleukin 1 beta; IL6: interleukin 6; IOD: integral optical density; KO: knockout; Leu: leupeptin; LPIN1: lipin 1; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MCD: methionine choline-deficient; MMP9: matrix metallopeptidase 9; mRNA: messenger RNA; MTORC1: mechanistic target of rapamycin kinase complex 1; NAFLD: nonalcoholic fatty liver diseases; NASH: nonalcoholic steatohepatitis; PA: palmitic acid; PPARA/PPARα: peroxisome proliferator activated receptor alpha; PPARG/PPARγ: peroxisome proliferator activated receptor gamma; qRT-PCR: quantitative real-time PCR; RPS6KB1/p70S6K1: ribosomal protein S6 kinase, polypeptide 1; RPTOR: regulatory associated protein of MTOR complex 1; SCD1: stearoyl-Coenzyme A desaturase 1; SEM: standard error of the mean; siRNA: small interfering RNA; SQSTM1/p62: sequestosome 1; TFEB: transcription factor EB; TG: triglyceride; TGFB/TGF-β: transforming growth factor, beta; TIMP1: tissue inhibitor of metalloproteinase 1; TNF/TNF-α: tumor necrosis factor; TXNIP/VDUP1: thioredoxin interacting protein; WT: wild-type.

Keywords: Lipid metabolism; MAP1LC3B; NASH; PRKAA; SQSTM1; liver.

The aims of the present study were to identify correlates of alanine aminotransferase (ALT or GPT) and aspartate aminotransferase (AST or GOT) activities among a healthy working population aged 18-39, and to discuss liver transferase abnormalities. Subjects included 1,009 employees of a company in Fukushima, Japan. Pregnant women, employees exposed to organic solvents, and employees with a history of liver diseases were excluded. Serum ALT and AST levels were measured by an enzymatic method. Other information including BMI, job type and lifestyles was recorded. Mean ALT and AST levels were significantly higher for males than females (P < 0.001). Multiple linear regression analysis revealed that sex and BMI explained 45% and 31% of the variability in ALT and AST, respectively. The prevalence of abnormal ALT levels >> 40 IU) was 16.3% for males and 0.4% for females. Sex, BMI, and shift work were independently associated with abnormal ALT levels by logistic regression analysis. It is concluded that ALT and AST levels are well-correlated with sex and BMI, and that abnormal liver transferase activity is prevalent in male employees but rare in females, suggesting that liver function tests should be introduced for male employees under 40 years of age.

This paper introduces GPT.EXE, a computer program for designing and implementing general processing tree (GPT) models. First, designing and building GPT models using this program is discussed. The second major emphasis is a description of various statistical procedures that can be carried out with GPT.EXE. There is also a brief section on the on-line documentation of this program. Throughout the text, pictures of windows from the program are displayed to help explain the procedures being described by the text.

The mechanism imparting thermotolerance by gibberellic acid (GA3) and abscisic acid (ABA) is still unresolved using either spraying technique or in vitro conditions. Alternative way of studying these effects under near in vivo conditions is through the use of liquid culturing technique. Effects of GA3 and ABA (100 μM) on sucrose metabolism (invertase and sucrose synthase) and aminotransferases (GOT and GPT) in relation to starch and protein accumulation were studied in detached panicles of three wheat (Triticum aestivum L.) cultivars PBW 343, C 306 (heat tolerant) and WH 542 (heat susceptible) cultured in a liquid medium. Ears were subjected to heat shock treatment (45 °C for 2 h) and then maintained at 25 °C for 5 days. Heat shock treatment resulted in a significant decline in starch content but caused a marked build -up of total free sugars and protein content in grains of all cultivars. However, activities of acid and neutral invertases increased only in tolerant cultivars but reduced in susceptible cultivar. Following treatment with GA3 contents of starch and free sugars increased in grains maintained at 25 °C but free sugar content decreased in stressed grains compared to control. ABA application showed inhibitory effect on starch accumulation under normal temperature but was promotory under stress conditions. Concomitantly, soluble protein content also increased in conjunction with an increase in the activities of glutamate-oxaloacetate transaminase (GOT) and glutamate-pyruvate transaminase (GPT). Apparently, the wheat grain responds to heat shock mediated disruption of carbon metabolism by a compensatory effect on nitrogen metabolism. GA3 stimulated grain sink activity both under stress and non stress condition while ABA was promotory only under stress condition.

Dyslipidemia is common in chronic hemodialysis patients and its underlying mechanism is complex. Hemodialysis causes an imbalance between antioxidants and production of reactive oxygen species, which induces the oxidative stress and thereby may lead to accelerated atherosclerosis. Statins have been found to be little effective in end-stage kidney disease and other lipid-lowering therapies have been only scarcely studied. The study aimed to assess the effect of low-dose fenofibrate therapy on plasma lipids and redox status in long-term hemodialysis patients with mild hypertriglyceridemia.Twenty seven chronic hemodialysis patients without any lipid-lowering therapy were included in a double-blind crossover, placebo-controlled study. The patients were randomized into two groups and were given a sequence of either 100 mg of fenofibrate per each hemodialysis day for 4 weeks or placebo with a week-long wash-out period between treatment periods. Plasma lipids, high sensitive C-reactive protein (CRP), urea, creatinine, electrolytes, phosphocreatine kinase (CK), GOT, GPT and plasma thiols (total and free glutathione, homocysteine, cysteine and cysteinylglycine) were measured at baseline and after each of the study periods. Plasma aminothiols were measured by reversed phase HPLC with thiol derivatization with 2-chloro-1-methylquinolinium tetrafluoroborate.Fenofibrate therapy caused a significant decrease of total serum cholesterol, LDL cholesterol and triglycerides and an increase of HDL cholesterol. The treatment was well tolerated with no side-effects but there was a small but significant increase of CK not exceeding the upper limit of normal range. There were no changes of serum CRP, potassium, urea, and creatinine and liver enzymes during the treatment. Neither total nor total free cysteinylglycine and cysteine changed during the study but both total and free glutathione increased during the therapy with fenofibrate and the same was observed in case of plasma homocysteine.The study shows that a treatment with reduced fenofibrate dose is safe and effective in reducing serum triglycerides and cholesterol in chronic dialysis patients and may shift plasma aminothiol balance towards a more antioxidative pattern.

We investigated changes in serum leukocyte cell-derived chemotaxin2 (LECT2) levels between donors and recipients in the early period during liver regeneration following adult living related donor liver transplantation (LRDLT). Five recipients (three women, two men; 37.0 +/- 15.8 years old), all of whom had end-stage liver failure, underwent LRDLT from healthy five donors (two women, three men; 41.6 +/- 14.3 years old) between June 2000 and February 2001. FK506 and methylprednisolone were used as immunosuppressants for recipients. Serum LECT2 levels decreased immediately after both the hepatectomy in all donors and the implantation of liver graft in all recipients. Donors showed a nadir at 3 to 12 hours, increasing at 24 to 48 hours. The nadir in recipients occurred several hours after the donors. The serum LECT2 levels of donors were significantly higher than those of recipients on day 5 (9.5 +/- 5.9 ng/mL vs 3.1 +/- 2.2 ng/mL, P = .04) and on day 7 (9.3 +/- 3.8 ng/mL vs 3.5 +/- 1.1 ng/mL, P = .04). Serum GPT and GOT levels were inversely proportionate to the serum LECT2 levels. The present studies suggest that LECT2 participates in liver regeneration and injury following hepatectomy.

Groups of 28 male and 28 female CD-1 mice and Fischer 344 rats were exposed to a mixture of 1,3-Dichloropropene and 1,2-Dichloropropane (D-D) vapors. Exposure concentrations were 0, 5 (4.7), 15 (14.4), or 50 (53.7) ppm, 6 h/d, 5 d/wk for 6 or 12 wk. The following parameters were evaluated: pharmacotoxic signs, body weights, hematology (HGB, HCT, RBC, WBC, and diff. leukocyte count), serum chemistry (BUN, GLU, ALB, GPT, and ALP), urinalysis, gross pathology, histopathology, organ weights, and organ weight/body weight ratios of brain, heart, liver, kidneys, testes or ovaries, and adrenals. The only exposure-related clinical effects observed were increased mean liver/body weight ratios of male rats and mean kidney/body weight ratios of female rats at the 50 ppm exposure level. Slight to moderate diffuse hepatocytic enlargement in 12 of 21 of the 50-ppm male mice after 12 wk exposure was the only compound-related histopathologic change present.

Genomic DNA from normal human or mouse cells was transfected together with the selectable marker gpt into the simian virus 40-transformed ataxia telangiectasia fibroblast line, AT5BIVA. From a series of experiments involving over 400,000 clones selected for the gpt marker, one unambiguously radiation-resistant clone (clone 67) was recovered following selection with repeated cycles of gamma irradiation. The normal level of radiation resistance of clone 67 has been maintained for at least 11 months in the absence of further selection by radiation. The resistant clone contains one copy of the gpt gene. Its DNA synthesis following gamma-irradiation is inhibited to an extent intermediate between that of ataxia telangiectasia and normal cells. Three out of four thioguanine-resistant derivatives of clone 67 have either lost or do not express the gpt sequence and show almost the same sensitivity to gamma irradiation as the original AT5BIVA line. This suggests that the radiation resistance of clone 67 may be linked to the gpt sequence and may have arisen as a consequence of the transfection, rather than as the result of an independent mutation to radiation resistance.

GPT phenotype determinations were performed in 4,148 unrelated Norwegians. The frequencies of the two common alleles were Gpt1 = 0.537 and Gpt2 = 0.461. A total of 13 individuals showed the phenotypic expression of 3 rare GPT alleles, Gpt3, Gpt6, and Gpt7. No heterogeneity in phenotype distribution was found, neither in the two sexes nor regionally in Norway. 97 foreigners involved in paternity cases in Norway showed a phenotype distribution not differing from that of Norwegians. In two small additional samples of Ethiopians and Easter Islanders, Gpt1 frequencies were 0.737 and 0.531, respectively. There were significant differences in phenotype distribution between NOrwegians and all African populations tested, some of the Asiatic population, Lapps and a few other populations.

The assumption that mutagens have linear dose-responses recently has been challenged. In particular, ethyl methanesulfonate (EMS), a DNA-reactive mutagen and carcinogen, exhibited sublinear or thresholded dose-responses for LacZ mutation in transgenic Muta™Mouse and for micronucleus (MN) frequency in CD1 mice (Gocke E and Müller L [2009]: Mutat Res 678:101-107). In order to explore variables in establishing genotoxicity dose-responses, we characterized the genotoxicity of EMS using gene mutation assays anticipated to have lower spontaneous mutant frequencies (MFs) than Muta™Mouse. Male gpt-delta transgenic mice were treated daily for 28 days with 5 to 100 mg/kg EMS, and measurements were made on: (i) gpt MFs in liver, lung, bone marrow, kidney, small intestine, and spleen; and (ii) Pig-a MFs in peripheral blood reticulocytes (RETs) and total red blood cells. MN induction also was measured in peripheral blood RETs. These data were used to calculate Points of Departure (PoDs) for the dose responses, i.e., no-observed-genotoxic-effect-levels (NOGELs), lower confidence limits of threshold effect levels (Td-LCIs), and lower confidence limits of 10% benchmark response rates (BMDL10 s). Similar PoDs were calculated from the published EMS dose-responses for LacZ mutation and CD1 MN induction. Vehicle control gpt and Pig-a MFs were 13-40-fold lower than published vehicle control LacZ MFs. In general, the EMS genotoxicity dose-responses in gpt-delta mice had lower PoDs than those calculated from the Muta™Mouse and CD1 mouse data. Our results indicate that the magnitude and possibly the shape of mutagenicity dose responses differ between in vivo models, with lower PoDs generally detected by gene mutation assays with lower backgrounds.

During the recovery stage of the hemolytic uremic syndrome in 2 cases an increase of serum levels of GOT, GPT, LDH, gammaGT, 5'ND and AP was noticed, without signs of a recurrence of the disease. In one patient also jaundice and hepatomegaly were found. The observations suggest a parenchymal damage of the liver.

5-azacytidine induces 6-thioguanine resistance in AS52 cells. To characterize these resistant clones, we isolated 148 of them from 50 independently treated flasks. Less than nine (6%) of the 148 variants were spontaneous. PCR amplification of the DNA primers flanking the gpt gene produced no product in 15 clones (10%). Of the 133 remaining clones, 52 showed sequence alterations in the gpt structural gene. Of these 52, 34 (65%) were GC->>CG transversions. Only seven were located in CpG sequences. Thus, methyltransferase complexes are not major contributors to 5-azacytidine-induced point mutations in AS52 cells. The remaining 81 clones had no sequence alterations within the coding region of the gpt gene. Southern blot analysis of a sample of these variants (37/81) indicated that the 6-thioguanine-resistant phenotype was not due to local rearrangements or deletions (resolution 50 bp). Sequence analysis of the early promoter region of another sample of these variants (24/81) indicated that lesions in the promoter could not be responsible for the 6-thioguanine resistance observed. Thus, a majority of these variants were formed via a mechanism other than small genomic rearrangements, point mutations or deletions of the gpt structural gene or its promoter. Neither the mechanisms leading to these variants nor the biological and morphological consequences of these variants are known.

BACKGROUND

Sequence periodicity with a period close to the DNA helical repeat is a very basic genomic property. This genomic feature was demonstrated for many prokaryotic genomes. The Escherichia coli sequences display the period close to 11 base pairs.

RESULTS

Here we demonstrate that practically only ApA/TpT dinucleotides contribute to overall dinucleotide periodicity in Escherichia coli. The noncoding sequences reveal this periodicity much more prominently compared to protein-coding sequences. The sequence periodicity of ApC/GpT, ApT and GpC dinucleotides along the Escherichia coli K-12 is found to be located as well mainly within the intergenic regions.

CONCLUSIONS

The observed concentration of the dinucleotide sequence periodicity in the intergenic regions of E. coli suggests that the periodicity is a typical property of prokaryotic intergenic regions. We suppose that this preferential distribution of dinucleotide periodicity serves many biological functions; first of all, the regulation of transcription.