Genome-Wide Identification and Analysis of Ariadne Gene Family Reveal Its Genetic Effects on Agronomic Traits of Brassica napus

E3 ligases promote protein ubiquitination and degradation, which regulate every aspect of eukaryotic life. The Ariadne (ARI) proteins of RBR (ring between ring fingers) protein subfamily has been discovered as a group of potential E3 ubiquitin ligases. Only a few available research studies show their role in plant adaptations processes against the external environment. Presently, the functions of ARI proteins are largely unknown in plants. Therefore, in this study, we performed genome-wide analysis to identify the ARI gene family and explore their potential importance in B. napus. A total of 39 ARI genes were identified in the B. napus genome and were classified into three subfamilies (A, B and C) based on phylogenetic analysis. The protein–protein interaction networks and enrichment analysis indicated that BnARI genes could be involved in endoreduplication, DNA repair, proteasome assembly, ubiquitination, protein kinase activity and stress adaptation. The transcriptome data analysis in various tissues provided us an indication of some BnARI genes’ functional importance in tissue development. We also identified potential BnARI genes that were significantly responsive towards the abiotic stresses. Furthermore, eight BnARI genes were identified as candidate genes for multiple agronomic traits through association mapping analysis in B. napus; among them, BnaA02g12100D, which is the ortholog of AtARI8, was significantly associated with ten agronomic traits. This study provided useful information on BnARI genes, which could aid targeted functional research and genetic improvement for breeding in B. napus.

Distribution, species composition and relative abundances of sandflies in North Waziristan Agency, Pakistan

This study was conducted to investigate the diversity of sandflies (Psychodidae: Phlebotominae) and the incidence of leishmaniasis in three villages of North Waziristan Agency, Pakistan. Sandflies were sampled monthly during 2012, at dusk and dawn, in selected indoor habitats including both bedrooms and animal sheds using a knock-down spray catch method. A total of 3687 sandflies were collected, including 1444 individuals in Drezanda, 1193 in Damdil and 1050 in Dattakhel. This study revealed 14 species of two genera, Phlebotomus (Phlebotomus sergenti, Phlebotomus papatasi, Phlebotomus caucasicus, Phlebotomus kazeruni, Phlebotomus alexandri and Phlebotomus salehi) and Sergentomyia (Sergentomyia dentate, Sergentomyia baghdadis, Sergentomyia babu, Sergentomyia theodori, Sergentomyia sumbarica, Sergentomyia dreyfussitur kestanica, Sergentomyia hogsoni pawlowskyi and Sergentomyia fallax afghanica) (both: Diptera: Psychodidae). Phlebotomus sergenti was the most abundant species (42.1%), followed by S. dentata (17.7%) and S. baghdadis (17.4%). The number of males collected represented about twice that of female flies, and the maximum number was collected in July, followed by August. The determination of the species composition of sandfly populations, seasonal variations, relative abundances and estimations of infection in the vector population may provide information about the dynamics of leishmaniasis transmission that is useful in planning vector control activities.

Knowledge, attitude and practice of emergency contraceptive pills among tertiary level students in Trinidad: a cross-sectional survey

OBJECTIVE

The objective of this study was to estimate the general knowledge, attitude and practice of Emergency Contraceptive pills (ECs) among tertiary level students in Trinidad.

METHOD

A 32-item questionnaire was constructed to assess knowledge, attitudes and practice of EC. There were 76 medical and 160 non-medical students who volunteered to fill-up the questionnaire. This survey was conducted by graduate students under supervision of the Department of Mathematics and Computer Science, UWI, St Augustine.

RESULTS

Eighty-four per cent of the students were less than 25 years of age, 64% were Christians and 92% were single. Sixty-three per cent were female and there were more females in the non-medical group than the medical students group but the numbers were not significant. Eighty-one per cent used condoms as the main type of contraception. Only 63% had heard of ECs before and only 9% had heard of ECs from medical sources. Among the factors that related to attitude towards EC, only two factors were significant. Sixty-two per cent of students felt that increased EC use would increase promiscuity (p = 0.013) but 59% also felt that ECs should be made more easily available (p = 0.014).

CONCLUSION

The general level of their knowledge about ECs was poor. The general attitude of students towards ECs was positive. This study will help policy-makers by providing evidence-based knowledge to promote EC use among university students.

Alpha-lipoic acid mitigates insulin resistance in Goto-Kakizaki rats

Impaired glucose uptake and metabolism by peripheral tissues is a common feature in both type I and type II diabetes mellitus. This phenomenon was examined in the context of oxidative stress and the early events within the insulin signalling pathway using soleus muscles derived from non-obese, insulin-resistant type II diabetic Goto-Kakizaki (GK) rats, a well-known genetic rat model for human type II diabetes. Insulin-stimulated glucose transport was impaired in soleus muscle from GK rats. Oxidative and non-oxidative glucose disposal pathways represented by glucose oxidation and glycogen synthesis in soleus muscles of GK rats appear to be resistant to the action of insulin when compared to their corresponding control values. These diabetes-related abnormalities in glucose disposal were associated with a marked diminution in the insulin-mediated enhancement of protein kinase B (Akt/PKB) and insulin receptor substrate-1 (IRS-1)-associated phosphatidylinostol 3-kinase (PI 3-kinase) activities; these two kinases are key elements in the insulin signalling pathway. Moreover, heightened state of oxidative stress, as indicated by protein bound carbonyl content, was evident in soleus muscle of GK diabetic rats. Chronic administration of the hydrophobic/hydrophilic antioxidant alpha -lipoic-acid (ALA, 100 mg/kg, i.p.) partly ameliorated the diabetes-related deficit in glucose metabolism, protein oxidation as well as the activation by insulin of the various steps of the insulin signalling pathway, including the enzymes Akt/PKB and PI-3 kinase. Overall, the current investigation illuminates the concept that oxidative stress may indeed be involved in the pathogenesis of certain types of insulin resistance. It also harmonizes with the notion of including potent antioxidants such as ALA in the armamentarium of antidiabetic therapy.

[Role of cell migration in the pathogenesis of rheumatoid arthritis: in vivo studies in SCID mice transplanted with human synovial membrane]

OBJECTIVE

Adhesion mechanisms play a central role in the recruitment of leukocytes which characteristically infiltrate rheumatoid synovium. Therefore, we adapted an animal model, in which human rheumatoid synovium was transplanted into severe combined immunodeficient (SCID) mice, to study the effects of Tumor Necrosis Factor-alpha (TNF-alpha) in modulatine leukocyte migration and to investigate the chemotactic potential of Stromal Derived Factor-1 alpha (SDF-1 alpha).

MATERIALS AND METHODS

Human synovium samples, obtained from patients undergoing joint replacement, were divided into two parts. One was analysed by immunohistology and the other was implanted subcutaneously into SCID mice under general anaesthesia. Four weeks post-transplantation, grafts were injected with optimal dose of SDF-1, TNF-alpha or saline (negative control). At the same time, animals were injected iv with fluorescently labelled cells. 48 hours later mice were sacrificed and grafts removed for cryo-hystology. The number of cells migrating to the grafts was determined by UV-microscopy and the results expressed as cells per high power field.

RESULTS AND CONCLUSIONS

In these studies we provide the evidence that: 1) the animal model, in which human tissues are grafted into SCID mice, can be used to study cell migration under controlled experimental conditions; 2) direct intragraft injection of TNF-alpha increases lymphocytes migration and up-regulates the expression of human adhesion molecules (CAMs) and 3) SDF-1 alphainjected intragraft increases the migration of the pro-myelo-monocytic U937 cells to synovial transplants, even more efficiently than TNF-alpha, but without modifications of CAMs' expression.

Stromal cell-derived factor 1 (CXCL12) induces monocyte migration into human synovium transplanted onto SCID Mice

OBJECTIVE

The mechanisms by which monocyte/macrophage cells migrate to the joint involve a series of integrated adhesion and signaling events in which chemokines and their receptors are strongly implicated. This study was undertaken to investigate the hypothesis that stromal cell-derived factor 1 (SDF-1), a CXC chemokine (CXCL12), plays a critical role in monocyte/macrophage localization to synovium.

METHODS

SDF-1 and CXC receptor 4 (CXCR4) expression in rheumatoid arthritis (RA) and osteoarthritis synovium and graft SDF-1, tumor necrosis factor alpha (TNF alpha), and human and murine vascular markers were examined by immunohistochemistry and double-immunofluorescence. The functional capacity of SDF-1 to modulate monocyte migration into joints was investigated by examining the localization of pro-myelomonocytic U937 cells into synovial tissue transplanted into SCID mice. SDF-1, TNF alpha, or saline was injected into graft sites and response determined by the number of fluorescently labeled U937 cells (injected intravenously) detected in grafts by ultraviolet microscopy.

RESULTS

SDF-1 and CXCR4 were highly expressed in CD68+ cells in the RA synovium. SDF-1 induced U937 cell migration in vitro and in vivo in a dose-dependent manner and, in vivo, SDF-1 was more effective than TNF alpha. In contrast to TNF alpha, SDF-1 did not induce intracellular adhesion molecule 1 in transplant microvasculature. Furthermore, intragraft injection of SDF-1 did not up-regulate TNF alpha, or vice versa.

CONCLUSION

This study demonstrates, for the first time, that SDF-1 is functional in vivo when injected into synovial grafts. In addition, SDF-1 is more potent than TNF alpha, and its mechanisms of action appear to be autonomous. Therefore, SDF-1 may be an important TNF-independent molecule involved in the migration to and retention of inflammatory effector cells in the joint.

Tumour necrosis factor-alpha (TNF-alpha) enhances lymphocyte migration into rheumatoid synovial tissue transplanted into severe combined immunodeficient (SCID) mice

Adhesion mechanisms play a major role in the recruitment of peripheral blood lymphocytes (PBL) which characteristically infiltrate rheumatoid arthritis (RA) synovium and other chronically inflamed tissues. Through a sequential series of complex integrated adhesion and signalling events, 'multistep model of migration', specific subsets of PBL are recruited into inflamed tissues. In this process both leucocyte receptors and microvascular endothelial (MVE) counter-receptors play a critical role. The MVE in particular, during an inflammatory state, is the target of various inflammatory mediators that cause the up-regulation of several cell adhesion molecules (CAM). One of the most important factors known to be a powerful inducer of MVE CAM is TNF-alpha. Conversely, blocking TNF-alpha causes a down-modulation of CAM expression. To test directly the capacity of TNF-alpha to induce cell migration into RA synovium we adapted a model in which synovial grafts were implanted into SCID mice subcutaneously. Using this model we demonstrate that: (i) transplants remain viable and become vascularized and fed by mouse subdermal vessels; (ii) the mouse vasculature connects to the transplant vasculature which maintains the ability to express human CAM; (iii) intragraft injections of TNF-alpha up-regulate the expression of human CAM, following the down-regulation which occurred 4 weeks post-transplantation; and (iv) the up-regulation of graft CAM is associated with increased human PBL migration into the transplants. This study provides direct evidence in vivo of the capacity of TNF-alpha to induce cell migration. In addition, it provides the experimental background for the optimal use of this model.

Modulation of cellular annexin I in human leukocytes infiltrating DTH skin reactions

Based on our previous studies showing endogenous annexin I being depleted from migrated neutrophils (PMN) in vitro, we have tested whether the levels of this glucocorticoid-regulated protein in PMN and mononuclear cells (PBMC) were modified after adhesion to endothelial monolayers in vitro and extravasation into skin blisters in vivo. In vitro, annexin I levels were depleted more significantly (-70%) in post-adherent PMNs than in monocytes (-25%) and lymphocytes (-50%, only in the positive fraction). In vivo, a significant time-dependent increase (approximately threefold, P < 0.05) in cell-associated annexin I was measured in PBMCs recovered from the blisters, whereas no significant changes were detected in extravasated PMNs. This was associated with annexin I release in the blister fluids (approximately 35 ng/mL), whereas no detectable protein was found in matched-paired plasmas. In conclusion, we report for the first time an activation of the annexin I pathway during an ongoing experimental inflammatory response in humans, which is differently regulated between PMNs and PBMCs.

Glucocorticoid-dependent impairment of wound healing in experimental diabetes: amelioration by adrenalectomy and RU 486

BACKGROUND

Failure of wounds to heal represents one of the major diabetic complications. Emerging evidence favors the involvement of glucocorticoids (GCs) in the pathogenesis of impaired wound healing in diabetes mellitus.

OBJECTIVE

The purpose of this study was to examine wound healing potential in diabetics under conditions in which the hypercortisolemic state is normalized.

DESIGN AND INTERVENTION

Linear skin incision and polyvinyl alcohol (PVA) sponge were used as wound healing models. Six groups of rats matched with respect to age, sex, and strain were included in this study. Animals in groups 1 and 6 were injected with citrate buffer, whereas rats in groups 2,3,4, and 5 received streptozotocin (STZ, 55 mg/kg iv in citrate buffer). Five days later animals in groups 4,5, and 6 received insulin (group 4) and subcutaneous implantation of slow-releasing pellets containing either the GC receptor blocker RU 486 (group 5) or a high dose of GC (group 6).

MAIN OUTCOME MEASUREMENTS

Skin wound tensile strength and PVA sponge collagen metabolism were determined using tensiometric, spectrosphotometric, and polymerase chain reaction-based assays. In addition, cell infiltration and granulation tissue growth were assessed using a well-established histochemical technique.

RESULTS

Wound-related parameters including fibroplasia, neovascularization, and inflammatory cell numbers were reduced as a function of diabetes. Similarly, skin wound tensile strength, PVA sponge hydroxyproline content, and the levels of mRNA transcripts for type I and III collagen were also decreased in this disease state. This diabetes-related deficit in wound healing potential was ameliorated by subjecting diabetic animals to insulin treatment or by counteracting the excessive actions of GCs using both pharmacological (RU 486) and endocrinological (ADX) paradigms.

CONCLUSION

The current study supports the notion that GCs are implicated in the wound healing deficit of diabetics. Moreover, it illuminates the therapeutic potential of the GC receptor blocker (e. g., RU 486) in promoting wound repair under hypercortisolemic conditions including diabetes and Cushing's syndrome.

Human p59fyn(T) regulates OKT3-induced calcium influx by a mechanism distinct from PIP2 hydrolysis in Jurkat T cells

The earliest biochemical event after cross-linking of TCR is the tyrosine phosphorylation of a variety of substrates. At least three nonreceptor tyrosine kinases have been implicated in this signaling cascade: p59fyn(T), p56lck, and ZAP-70. Recently, PLC gamma 1 has been shown to be tyrosine phosphorylated in T cells after receptor activation. This increase in tyrosine phosphorylation correlates with the increased activity of the enzyme. The substrate for PLC gamma 1, phosphatidylinositol 4,5-bisphosphate (PIP2), is hydrolyzed to the protein kinase C activator diacylglycerol and inositol 1,4,5-triphosphate (IP3), which promotes calcium release from the endoplasmic reticulum. These results lend support to the notion that calcium mobilization after TCR cross-linking is mediated by increased levels of IP3. In this study we have cloned and transfected a human p59fyn(T) cDNA in the anti-sense configuration into the human T cell line, Jurkat, resulting in decreased expression of the protein. We find that cell lines expressing significantly reduced levels of p59fyn(T) exhibit significantly lower calcium influx following OKT3 activation. However, the level of IP3 production was unchanged and IP1 and IP2 levels were elevated. These data indicate that p59fyn(T) can regulate calcium influx by a mechanism distinct from PIP2 hydrolysis.

Human p59fyn(T) regulates OKT3-induced calcium influx by a mechanism distinct from PIP2 hydrolysis in Jurkat T cells

The earliest biochemical event after cross-linking of TCR is the tyrosine phosphorylation of a variety of substrates. At least three nonreceptor tyrosine kinases have been implicated in this signaling cascade: p59fyn(T), p56lck, and ZAP-70. Recently, PLC gamma 1 has been shown to be tyrosine phosphorylated in T cells after receptor activation. This increase in tyrosine phosphorylation correlates with the increased activity of the enzyme. The substrate for PLC gamma 1, phosphatidylinositol 4,5-bisphosphate (PIP2), is hydrolyzed to the protein kinase C activator diacylglycerol and inositol 1,4,5-triphosphate (IP3), which promotes calcium release from the endoplasmic reticulum. These results lend support to the notion that calcium mobilization after TCR cross-linking is mediated by increased levels of IP3. In this study we have cloned and transfected a human p59fyn(T) cDNA in the anti-sense configuration into the human T cell line, Jurkat, resulting in decreased expression of the protein. We find that cell lines expressing significantly reduced levels of p59fyn(T) exhibit significantly lower calcium influx following OKT3 activation. However, the level of IP3 production was unchanged and IP1 and IP2 levels were elevated. These data indicate that p59fyn(T) can regulate calcium influx by a mechanism distinct from PIP2 hydrolysis.

Kimura's disease: clinical, histological and immunohistochemical studies

In the present study, 14 cases of Kimura's disease were clinicopathologically studied. The disease occurred at ages ranging from 5 to 75 years. The average age was 37.8 years. Sexes were about equally affected. The most common sites were the subcutis of head and neck, and parotid gland. Simultaneous involvement of lymph nodes occurred in 5 cases. Laboratory findings revealed eosinophilia in almost all the patients, but serum IgE levels were not elevated in 2 patients. Lesions were surgically removed and the clinical course thereafter was favorable for all but one case. Histologically, lesions were characterized by lymphoid follicles, granulation tissue with infiltration by many eosinophils, lymphocytes, plasma cells, mast cells and histiocytes, proliferation of blood vessels and fibrosis. Immunohistochemically, IgE reacted strongly in germinal centers, showing a reticular pattern. IgG-, IgA- and lysozyme-positive cells were scattered mainly in interfollicular granulomatous areas. Pathogenesis of this disease is briefly discussed.

Effects of intracellular cyclic AMP and cyclic GMP levels on DNA synthesis of young-adult rat hepatocytes in primary culture

Possible roles of dibutyryladenosine 3',5'-cyclic monophosphate (cAMP) and dibutyryl-guanosine 3',5'-cyclic monophosphate (cGMP) in regulation of hepatocyte DNA synthesis were examined using primary cultures of young-adult rat hepatocytes maintained in arginine-free medium. Throughout the experimental period, nonparenchymal cells were hardly observed in the selective medium. When epidermal growth factor (EGF) was added to the cultures, a transient increase in the intracellular cAMP level preceded the elevation of hepatocyte DNA synthesis. EGF-stimulated hepatocyte DNA synthesis was remarkably enhanced by the elevation of the intracellular cAMP level induced by treatment with cAMP alone or a combination of cAMP and theophylline, an inhibitor of cyclic nucleotide phosphodiesterase. Furthermore, the early elevation of intracellular cAMP alone, which was induced by treatment with the combination of cAMP and theophylline, caused a remarkable increase in hepatocyte DNA synthesis. On the other hand, addition of EGF to the cultures caused a rapid decrease in the intracellular cGMP level followed by an increase in hepatocyte DNA synthesis. EGF-stimulated hepatocyte DNA synthesis was severely suppressed or completely inhibited by the elevation of the intracellular cGMP level induced by treatment with cGMP alone or a combination of cGMP and dipyridamole, a specific inhibitor of cGMP phosphodiesterase. These findings indicate that cAMP and cGMP act oppositely on the regulation of DNA synthesis of young-adult rat hepatocytes in primary culture: cAMP plays a positive role, whereas cGMP plays a negative role. Also it is strongly suggested that an early elevation of the intracellular cAMP level is essential for the onset of DNA synthesis in hepatocyte primary cultures.

In vivo and in vitro test for growth potential of liver cells from rats during early stage of hepatocarcinogenesis by 3'-methyl-4-dimethylaminoazobenzene

A rapid increase in the fraction of small liver cells was observed in the liver of rats during the early stage of hepatocarcinogenesis by 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB). The change in cell population was represented by the decrease in glucose-6-phosphatase activity and by the increase in number of gamma-glutamyltranspeptidase-positive cells. When DNA synthesis of liver cells from rats fed 3'-Me-DAB was measured by autoradiography in primary culture, it began to increase 2 weeks after the start of the carcinogen feeding, reaching a plateau level after 3 weeks. Liver cells from rats fed 3'-Me-DAB for 2 weeks or over demonstrated a remarkable resistance to the cytotoxic effect of the carcinogen (0.24 mM) in primary culture. Furthermore, liver cells from rats fed 3'-Me-DAB for 3 weeks or over proliferated in the presence of the carcinogen in primary culture. When liver cells from 3'-Me-DAB-fed and control rats were transplanted into syngeneic rat spleens, the former cells proliferated more vigorously than did the latter. The growth potential of liver cells from 3'-Me-DAB-fed rats tended to be enhanced with time in the carcinogen feeding. Hepatocellular carcinomas developed in the host spleens implanted with liver cells from a rat fed 3'-Me-DAB for 8 weeks. As described above, liver cells from rats fed 3'-Me-DAB demonstrated much greater proliferative ability than normal control cells in vivo and in vitro.

Comparison of cytologic and biochemical properties between liver cells isolated from adult rats by trypsin perfusion and those isolated by collagenase perfusion

Primary cultures of liver cells isolated from adult rats by trypsin and collagenase perfusion techniques were carried out to compare cytologic and biochemical properties between the differently prepared cells. Trypsin-dispersed cells consisted of comparatively smaller cells, whereas collagenase-dispersed cells consisted of larger cells. The cell attachment efficiency on culture day 1 was about twice as high in the liver cells prepared with collagenase than those prepared with trypsin. Mature hepatocytes isolated by collagenase perfusion could be maintained in the primary culture for a longer period than those isolated by trypsin perfusion. Epithelial-like clear cells started to grow much earlier in the primary culture of the trypsin-dispersed liver cells than in that of the collagenase-dispersed liver cells. Earlier proliferation of epithelial-like clear cells could not be induced by in vitro trypsinization of the collagenase-dispersed liver cells. Both kinds of enzymatically prepared liver cells showed albumin production and exhibited glucose 6-phosphatase (D-glucose-6-phosphate phosphohydrolase, EC 3.1.3.9, G6Pase) and tyrosine aminotransferase (L-tyrosine: 2-oxoglutarate amino-transferase, EC 2.6.1.5, TAT) activities for 1 week in the primary culture. Albumin production was higher in the liver cells prepared with collagenase than those prepared with trypsin, whereas G6Pase activity was almost the same between them. TAT activity up to culture day 2 was about 3-fold higher in the liver cells prepared with collagenase than in those prepared with trypsin. Combined supplementation of dexamethasone (1 X 10(-5)M) and insulin (10 micrograms/ml) consistently improved the cell attachment efficiency and was very effective in the maintenance of mature hepatocytes in both types. Furthermore, these hormones enhanced the albumin production and TAT activity in both types.

Preparation and primary culture of liver cells isolated from adult rats by dispase perfusion

The dispase perfusion technique was used to isolate liver cells from adult rats. The optimum conditions for obtaining many isolated liver cells with high viability were an enzyme concentration of 2000 U/ml, a pH of 7.5 and a perfusion time of 20 min. The population of isolated liver cells prepared with dispase consisted of 43.6% cells with diameters less than 20 micron and 56.4% cells with diameters above 20 micron. The isolated liver cells were cultured in basal culture medium either supplemented with or without dexamethasone (1 X 10(-5)M) and insulin (10 micrograms/ml). The addition of hormones to the culture medium improved the attachment efficiency of the isolated liver cells and delayed the disappearance of mature hepatocytes. Epithelial-like clear cells proliferated early in primary culture even in the presence of hormones. Therefore, functioning mature hepatocytes and proliferating epithelial-like clear cells coexisted well in the hormone-containing medium. Furthermore, the number of cultured cells reached a maximal level earlier in the presence of hormones than in the absence of hormones. The level of TAT activity in primary cultured cells was higher up to 3 days after inoculation in the presence of hormones than in their absence. No difference between G6Pase activity in primary cultured cells in the presence of hormones and that in the absence of hormones was found.

Expression of gamma-glutamyltranspeptidase in cultures of spontaneously and chemically transformed rat liver cells

The expression of gamma-glutamyltranspeptidase (gamma-GTP) and the relationship between this enzyme activity and tumorigenicity were studied in 38 tumorigenic and non-tumorigenic epithelial cell lines derived from livers of normal and aminoazo-dye-fed rats. Nine of 22 non-tumorigenic epithelial cell lines exhibited gamma-GTP-positive cells, whereas 9 of 16 tumorigenic epithelial cell lines did not exhibit gamma-GTP-positive cells. This finding revealed that no correlation existed between the acquisition of gamma-GTP activity and tumorigenicity. None of 10 spontaneously transformed epithelial cell lines, which consisted of 8 tumorigenic and 2 non-tumorigenic cell lines, exhibited gamma-GTP-positive cells. On the other hand, 16 of 28 transformed epithelial cell lines, which were derived from aminoazo-dye-fed rat livers and aminoazo-dye-treated cultures of normal rat liver cells, included gamma-GTP-positive cells in various percentages. As described above, in contrast to in vitro spontaneous transformation of rat liver cells, it is obvious that the carcinogen-induced transformation of rat liver cells in vitro as well as in vivo was frequently accompanied by the acquisition of gamma-GTP-activity. Therefore, it is concluded that the expression of gamma-GTP in liver cells may be mainly associated with exposure to chemical carcinogens.

In vitro transformation of adult rat liver cells by 3'-methyl-4-dimethylaminoazobenzene

Primary cultures of liver cells from normal adult rats were treated with 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) at various concentrations for 6 days. 3'-Me-DAB treatment induced rapid proliferation of epithelial clear cells with chromosomal abnormalities and gamma-glutamyl transpeptidase (GGT) activity. In early culture, marker chromosomes were detected in 13 of 44 3'-Me-DAB-treated cultures but not in control cultures. GGT activity was not detected in the epithelial clear cells in either 3'-Me-DAB-treated or control cultures. In late culture, 21 cell lines established from 39 carcinogen-treated cultures consisted of 3 diploid cell lines, 5 pseudodiploid cell lines and 13 aneuploid cell lines. Eighteen of these 21 cell lines had marker chromosomes. Of the 2 cell lines established from 15 control cultures both were aneuploid, but a marker chromosome was detected in only one of these. GGT activity was detected in 11 of 21 cell lines established from the carcinogen-treated cultures but not in those from control cultures. Morphological features of the cell lines which varied from normal to cancerous included polymorphism, increased nuclear/cytoplasmic ratio and prominent nucleoli. No cell line established in this study developed tumors in host rats during a 1-year observation period.

Selective growth of epithelial-like clear cells from adult rat liver by short-term exposure to glucocorticoids in primary culture

Isolated liver cells, which were prepared from adult rats by a trypsin-liver-perfusion technique, were treated with dexamethasone or hydrocortisone at a concentration of 7.7 X 10(-6) M for 8 days in primary culture. The treated cultures displayed homogeneous population consisting of epithelial-like clear cells, while the untreated cultures displayed mixed population consisting of epithelial-like clear cells and fibroblast-like cells. The epithelial-like clear cells, which proliferated in the cultures treated with glucocorticoids for 8 days in primary culture, did not show any morphological changes following cultivation in glucocorticoid-free medium. After continuous glucocorticoid-treatment for more than 1 month, the treated cultures showed relatively low cell densities at confluence. The surface area of individual epithelial-like clear cells in the cultures treated with glucocorticoids for long periods of time was evidently greater than that in the cultures treated for only 8 days. The epithelial-like clear cells had glucose 6-phosphatase and tyrosine aminotransferase activities even though the levels of these enzyme-activities were very low compared with those in rat liver homogenates.

Alpha-fetoprotein dynamics during ethionine-induced hepatocarcinogenesis in rat

Rats fed on a diet containing 0.25% DL-ethionine (ethionine), which has been usually used as carcinogenic dose, demonstrated the early elevations of serum alpha-fetoprotein (AFP) approximately in week 6 of the feedings. After declining once between week 10 and 14, the serum AFP levels increased again in week 22 of the continuous feeding, when well differentiated hepatocellular carcinoma had already developed. The level of serum AFP after development of hepatoma was found to be lower than those seen during the early elevation of AFP. Furthermore, in ethionine-induced hepatoma-bearing rats, AFP levels in the tumors were rather low as compared to those in the nontumorous portions of the liver surrounding the tumors. The results indicated that ethionine-induced hepatocellular carcinoma is not an AFP-highly-producing tumor.

Effect of 3'-methyl-4-dimethylaminoazobenzene on liver cells from adult rat in primary culture

Primary mass cultures of isolated liver cells, which prepared from normal adult rat by a collagenase-liver-perfusion technique, were treated with 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) to study the production of transformed liver cells. Enzymatically isolated liver cells had high sensitivity to 3'-Me-DAB in primary culture. By 2- or 6-day treatment, mature hepatocytes remarkably decreased in their numbers due to cytotoxic effect of 3-Me-DAB, but thereafter active proliferation of epithelial-like clear cells was observed. Six-day treatment induced epithelial-like clear cells with gross chromosomal abnormalities, although 2-day treatment failed to induce transformed cells. However, the transformed epithelial-like clear cells with chromosomal abnormalities were negative for gamma-glutamyl-transpeptidase (GGT).

Influence of methionine administration on serum alpha-fetoprotein levels in ethionine-injured rats

Serum alpha-fetoprotein (AFP) concentrations increased promptly 2 days following a single injection of DL-ethionine (ethionine) in adult female rats. Continuous elevation of serum AFP was also observed on feeding a diet containing 1% ethionine for at least 2-3 weeks. A rise of serum AFP was not found if the diet was supplemented with 2.8% methionine. Furthermore, in rats fed on 1% ethionine for 2 weeks, dietary change to the laboratory chow supplemented with and without 2.8% methionine produced a decrease of increased serum AFP levels.

Mitochondrial function following chronic ethanol treatment: effect of diet

Rats were fed liquid diets containing 36% of the calories as ethanol either in a high fat, adequate protein or in a high protein, low fat diet, with pair-fed controls receiving an isocaloric amount of sucrose replacing ethanol. Liver mitochondria were isolated in a fatty acid free albumin containing medium. Mitochondrial respiration respiratory control and ADP/O ratios were measured either using a glutamate-malate mixture or succinate. In rats fed the high fat adequate protein diet chronic ethanol treatment resulted in a reduction in the respiratory rates in states 3 and 4 with both substrates. However, such changes did not occur in rats fed high protein low fat diets. Using the NAD-linked substrates, but not with succinate, the respiratory control ratio was significantly decreased following ethanol treatment with the high fat adequate protein but not the high protein low fat diet. ADP/O ratios were not affected by the ethanol treatment with either diet. Ethanol metabolism rate increased by 70% in rats treated with ethanol containing high protein low fat diets and by 50% with ethanol containing high fat adequate protein diets.

Modulation of alcohol dehydrogenase and ethanol metabolism by sex hormones in the spontaneously hypertensive rat. Effect of chronic ethanol administration

In young (4-week-old) male and female spontaneously hypertensive (SH) rats, ethanol metabolic rate in vivo and hepatic alcohol dehydrogenase activity in vitro are high and not different in the two sexes. In males, ethanol metabolic rate falls markedly between 4 and 10 weeks of age, which coincides with the time of development of sexual maturity in the rat. Alcohol dehydrogenase activity is also markedly diminished in the male SH rat and correlates well with the changes in ethanol metabolism. There is virtually no influence of age on ethanol metabolic rate and alcohol dehydrogenase activity in the female SH rat. Castration of male SH rats prevents the marked decrease in ethanol metabolic rate and alcohol dehydrogenase activity, whereas ovariectomy has no effect on these parameters in female SH rats. Chronic administration of testosterone to castrated male SH rats and to female SH rats decreases ethanol metabolic rate and alcohol dehydrogenase activity to values similar to those found in mature males. Chronic administration of oestradiol-17beta to male SH rats results in marked stimulation of ethanol metabolic rate and alcohol dehydrogenase activity to values similar to those found in female SH rats. Chronic administration of ethanol to male SH rats from 4 to 11 weeks of age prevents the marked age-dependent decreases in ethanol metabolic rate and alcohol dehydrogenase activity, but has virtually no effect in castrated rats. In the intoxicated chronically ethanol-fed male SH rats, serum testosterone concentrations are significantly depressed. In vitro, testosterone has no effect on hepatic alcohol dehydrogenase activity of young male and female SH rats. In conclusion, in the male SH rat, ethanol metabolic rate appears to be limited by alcohol dehydrogenase activity and is modulated by testosterone. Testosterone has an inhibitory effect and oestradiol has a testosterone-dependent stimulatory effect on alcohol dehydrogenase activity and ethanol metabolic rate in these animals.