XYLITOL METABOLISM IN RAT LIVER AND HEPATOCELLULAR CARCINOMAS

The significance of nutritional factors in cancer research has been strongly emphasized. Such research is concerned not only with epidemiological effects relative to dietary factors on the causation of cancer, but with nutritional effects as an energy source on the prevention of cancer. Many studies speculate that the energy flow between tumor and host can be regulated by dietary intake. However, little knowledge on the comparison of the specific nutritional and energy requirements of different cells and tissues is available. Most popular and essential energy sources for the body are the carbohydrates. Among them, xylitol is known as efficient an energy source as glucose. In carbohydrate metabolism, glycolysis is one of the major energy producing pathways. However, recently the existence of an alternate catabolic pathway in mammals for carbohydrate besides glycolysis, i.e. bypass through triosephosphates to lactate via methylglyoxal has been suggested. This bypass was implicated to regulate glycolysis and also be responsible for the fluctuation in the levels of a regulator of cell growth. Methylglyoxal itself is known as a cancerostatic agent. The alterations of biochemical parameters in xylitol metabolism in animals indicated that xylitol may be metabolized through a methylglyoxal pathway.^ To elucidate the biological effect of xylitol as an energy source and the biological effect of its metabolites as a cancerostatis agent, the mode and extent of metabolism must be understood in tumor-bearing animals. Differential utilization of xylitol and glucose, if any, between tumor and host in such animals may exert tissue selective effects on both in terms of methylglyoxal formation and energy provision. The aim of this work was to assess the extent to which the differential utilization of xylitol might be used to generate different metabolic pathways in tumor and host, and to consider a role of nutrition in cancer.^ The results disclose that the existence of a pathway for biological methylglyoxal formation in normal rat liver has been confirmed in single cell suspension; the metabolic significance of the methylglyoxal pathway in the metabolism of glucose and xylitol has been evaluated quantitatively in normal rat liver and the differential metabolism of glucose and xylitol through overall catabolic pathways of carbohydrates has been studied in normal hepatic cells, AS-30D hepatoma and other several hepatoma lines. ^

Transcriptional analysis of liver-specific expression and differential interleukin-6 response of rat kininogen genes

Analyses of rat T1 kininogen gene/chloramphenicol acetyltransferase (T1K/CAT) constructs revealed two regions important for tissue-specific and induced regulation of T1 kininogen.^ Although the T1 kininogen gene is inducible by inflammatory cytokines, a highly homologous K kininogen gene is minimally responsive. Moreover, the basal expression of a KK/CAT construct was 5- to 7-fold higher than that of the analogous T1K/CAT construct. To examine the molecular basis of this differential regulation, a series of promoter swapping experiments was carried out. Our transfection results showed that at least two regions in the K kininogen gene are important for its high basal expression: a distal 19-bp region (C box) constituted a binding site for CCAAT/enhancer binding protein (C/EBP) family proteins and a proximal 66-bp region contained two adjacent binding sites for hepatocyte nuclear factor-3 (HNF-3). The distal HNF-3 binding site from the K kininogen promoter demonstrated a stronger affinity than that from the T1 kininogen promoter. Since C/EBP and HNF-3 are highly enriched in the liver and known to enhance transcription of liver-specific genes, differential binding affinities of these factors accounted for the higher basal expression of the K kininogen gene.^ In contrast to the K kininogen C box, the T1 kininogen C box does not bind C/EBP presumably due to their two-nucleotide divergence. This sequence divergence, however, converts it to a consensus binding sequence for two IL-6-inducible transcription factors--IL-6 response element binding protein and acute-phase response factor. To functionally determine whether C box sequences are important for their differential acute-phase response, T1 and K kininogen C boxes were swapped and analyzed after transfection into Hep3B cells. Our results showed that the T1 kininogen C box is indeed one of the IL-6 response elements in T1 kininogen promoter. Furthermore, its function can be modulated by a 5$\sp\prime$-adjacent C/EBP-binding site (B box) whose mutation significantly reduced the overall induced activity. Moreover, this B box is the target site for binding and transactivation of another IL-6 inducible transcription factor C/EBP$\delta.$ Evolutionary divergence of a few critical nucleotides can either lead to subtle changes in the binding affinities of a given transcription factor or convert a binding sequence for a constitutive factor to a site recognized by an inducible factor. (Abstract shortened by UMI.) ^

The heparan sulfate-fibroblast growth factor signaling system in liver growth and function

The heparan sulfate (HS)-fibroblast growth factor (FGF) signaling system is a ubiquitous regulator that senses local environmental changes and mediates cell-to-cell communication. This system consists of three mutually interactive components. These are regulatory polypeptides (FGF), FGF receptor (FGFR) and heparan sulfate proteoglycans (FGFRHS). All four FGFR genes are expressed in the adult liver. Expression of the FGFR1–3 genes is generally associated with non-parenchymal cells while expression of the FGFR4 gene is associated with parenchymal hepatocytes. We showed that livers of mice lacking FGFR4 exhibited normal morphology and regenerated normally in response to partial hepatectomy. However, the FGFR4 (−/−) mice exhibited depleted gallbladders, an elevated bile acid pool and elevated excretion of bile acids. Cholesterol- and bile acid-controlled liver cholesterol 7α-hydroxylase (Cyp7a), the limiting enzyme for bile acid synthesis, was elevated, unresponsive to dietary cholesterol, but repressed normally by dietary cholate. These results indicated that FGFR4 was not directly involved in liver growth but exerted negative control on liver bile acid synthesis. This was confirmed in transgenic mice overexpressing the constitutively active human FGFR4 in livers. The transgenic mice exhibited decreased fecal bile acid excretion, bile acid pool size, and expression of Cyp7a. Introduction of this constitutively active human FGFR4 into FGFR4 (−/−) mice restored the inhibition of bile acid synthesis. Activation of the c-Jun N-terminal Kinase (JNK) pathway by FGFR4 correlated with the repressive effect on bile acid synthesis. ^ To determine whether FGFR4 played a broader role in liver-specific metabolic function, we examined the impact of both acute and chronic exposure to CCl 4 in FGFR4 (−/−) mice. Following acute CCl4 exposure, the FGFR4 (−/−) mice exhibited accelerated liver injury, a significant increase in liver mass and delayed hepatolobular repair, with no apparent effect on liver cell proliferation and restoration of cellularity. Chronic CCl4 exposure resulted in severe fibrosis in livers of FGFR4 (−/−) mice compared to normal mice. Analysis at both mRNA and protein levels indicated an 8 hr delay in FGFR4-deficient mice in the down-regulation of cytochrome P450 2E1 (CYP2E1) protein, the major enzyme whose products underlie CCl 4-induced injury. These results show that hepatocyte FGFR4 protects against acute and chronic insult to the liver and prevents accompanying fibrosis. ^ Of the 23 FGF polypeptides, FGF1 and FGF2 are present at significant levels in the liver. To determine whether FGF1 and FGF2 played a role in CCl 4-induced liver injury and fibrosis, we examined the impact of both acute and chronic exposure to CCl4 in both wild-type and FGF1-FGF2 double-knockout mice. Following acute CCl4 exposure, FGF1(−/−)FGF2(−/−) mice exhibited accelerated liver injury, overall normal liver growth and repair, and decreased liver collagen α1(I) induction. Liver fibrosis resulting from chronic CCl4 exposure was markedly decreased in livers of FGF1(−/−)FGF2(−/−) mice compared to wild-type mice. This study suggests a role for FGF1 and FGF2 in hepatic fibrogenesis. ^ In summary, our three part study shows that specific components of the ubiquitous HS-FGF signaling family in the liver context interfaces with metabolite- and xenobiotic-controlled networks to regulate liver function, but has no apparent direct effect on liver cell growth. ^

A novel form of CYP3A from rat brain: cDNA cloning, protein characterization and gene regulation of cytochrome P450 3A9

One full length cDNA clone, designated 3aH15, was isolated from a rat brain cDNA library using a fragment of CYP3A2 cDNA as a probe. 3aH15 encoded a protein composed of 503 amino acid residues. The deduced amino acid sequence of 3aH15 was 92% identical to mouse Cyp3a-13 and had a 68.4% to 76.5% homology with the other reported rat CYP3A sequences. Clone 3aH15 was thus named CYP3A9 by Cytochrome P450 Nomenclature Committee. CYP3A9 seems to the major CYP3A isozyme expressed in rat brain. Sexual dimorphism of the expression of CYP3A9 was shown for the first time in rat brain as well as in rat liver. CYP3A9 appears to be female specific in rat liver based on the standards proposed by Kato and Yamazoe who defined sex specific expression of P450s as being a 10-fold or higher expression level in one sex compared with the other. CYP3A9 gene expression was inducible by estrogen treatment both in male and in female rats. Male rats treated with estrogen had a similar expression level of CYP3A9 mRNA both in the liver and brain. Ovariectomy of adult female rats drastically reduced the mRNA level of CYP3A9 which could be fully restored by estrogen replacement. On the other hand, only a two-fold induction of CYP3A9 expression by dexamethasone was observed in male liver and no significant induction of CYP3A9 mRNA was observed in female liver or in the brains. These results suggest that estrogen may play an important role in the female specific expression of the CYP3A9 gene and that CYP3A9 gene expression is regulated differently from other CYP3A isozymes. ^ P450 3A9 recombinant protein was expressed in E. coli using the pCWOri+ expression vector and the MALLLAVF amino terminal sequence modification. This construct gave a high level of expression (130 nmol P450 3A9/liter culture) and the recombinant protein of the modified P450 3A9 was purified to electrophoretic homogeneity (10.1 nmol P450/mg protein) from solubilized fractions using two chromatographic steps. The purified P450 3A9 protein was active towards the metabolism of many clinically important drugs such as imipramine, erythromycin, benzphetamine, ethylmorphine, chlorzoxazone, cyclosporine, rapamycin, etc. in a reconstituted system containing lipid and rat NADPH-P450 reductase. Although P450 3A9 was active towards the catabolism of testosterone, androstenedione, dehydroepiandrosterone (DHEA) and 17β-estradiol, P450 3A9 preferentially catalyzes the metabolism of progesterone to form four different hydroxylated products. Optimal reconstitution conditions for P450 3A9 activities required a lipid mixture and GSH. The possible mechanisms of the stimulatory effects of GSH on P450 3A9 activities are discussed. Sexually dimorphic expression of P450 3A9 in the brain and its involvement in many neuroactive drugs as well as neurosteroids suggest the possible role of P450 3A9 in some mental disorders and brain functions. ^

CISPLATIN NEPHROTOXICITY AND ITS EFFECTS ON GENTAMICIN PHARMACOKINETICS

Myelosuppression is a common side effect of anticancer agents such as cisplatin. This makes patients more susceptible to infections. Gentamicin is an aminoglycoside antibiotic that is very effective in the treatment of gram negative infections. Both these drugs are excreted by the kidney, and are also nephrotoxic. Thus, each may affect the disposition of the other. This project deals with the nature and duration of the effects of cisplatin on gentamicin pharmacokinetics in F-344 rats.^ The appropriate cisplatin dose was determined by comparing the nephrotoxicity of four intravenous doses--3, 4, 5, and 6 mg/kg. The 6 mg/kg dose gave the most consistent nephrotoxic effect, with peak plasma urea nitrogen and creatinine levels on the 7th day. Plasma and tissue gentamicin levels were compared between rats given gentamicin alone (30 mg/kg, intraperitoneally, twice a day for four days), and those given cisplatin (6 mg/kg, intraperitoneally) with the first gentamicin dose. Cisplatin caused a significant elevation of gentamicin levels in plasma, liver, and spleen. However, cisplatin given in three weekly doses of 2 mg/kg each, had no effect on plasma or tissue gentamicin levels.^ In order to determine the duration of cisplatin effects, a single dose of gentamicin (30 mg/kg, intravenously) was given to different groups of rats either alone, or on day 1, 4, 7, 15, or 29 following cisplatin (6 mg/kg, intravenously on day 1). Plasma samples were collected through a cannula placed on the external jugular vein at 0.5, 1, 2, 3, 4, 5, and 6 hours after gentamicin; the rats were sacrificed at 24 hours. Cisplatin caused a significant decrease in gentamicin excretion and an elevation of gentamicin levels in plasma, kidneys, liver, and spleen at all the time points that were tested, except with concomitant administration. Plasma urea nitrogen was elevated, and creatinine clearance decreased by the 4th day after cisplatin and these continued to be significantly different even on the 29th day after cisplatin.^ These results demonstrate that cisplatin nephrotoxicity reduced gentamicin excretion for at least a month in F-344 rats. This could increase the risk of toxicity from the second drug by elevating its levels in plasma and tissue. Thus, caution should be exercised when renally excreted drugs are given after cisplatin. ^

Cytochrome P450 4F isoforms in different species: Identification, gene regulation and putative roles in inflammation

The cytochrome P450 4F subfamily comprises a group of enzymes that metabolize derivatives of arachidonic acid such as prostaglandins, lipoxins leukotrienes and hydroxyeicosatetraenoic acids, which are important mediators involved in the inflammatory response. Therefore, we speculate that CYP4Fs might be able to modulate the extent of the inflammation by controlling of the tissue levels of these inflammatory mediators, especially, leukotriene B4. One way to provide support for this hypothesis is to test whether the expression of CYP4Fs changes under inflammatory conditions, since these changes are required to adjust the levels of inflammatory mediators. ^ A lipopolysacchride (LPS) induced rat inflammation model was used to analyze the expressions of rat CYP4F4 and CYP4F5 in liver and kidney. LPS administration did not change the constitutive expression level of CYP4F4 and CYP4F5. In liver, the expressions of CYP4F4 and CYP4F5 decreased to 50–60% of the untreated level. The same effect of LPS on CYP4F4 and CYP4F5 expression can be mimicked in hepatocyte primary cultures treated with LPS, indicating a direct of effect of LPS on hepatocytes. LPS treatment also decreased the activity of liver microsomes towards chlorpromazine, however, antibody inhibition study revealed that liver CYP4Fs are not the only players in metabolizing chlorpromazine. To study further the underlying mechanism, CYP4F5 gene was isolated, characterized, and the promoter region was defined. ^ Accumulating evidence showed that peroxisome proliferator-activated receptors (PPARs) play an active role in inflammation. To investigate the possible role of PPARα in regulating CYP4F expression by inflammation or by clofibrate treatment, the expressions of two new mouse 4F isoforms were analyzed in PPARα knockout mice upon LPS or clofibrate challenge. A novel induction of CYP4F15 by LPS and clofibrate was observed in kidney, and this effect is totally dependent on the presence of PPARα. Renal CYP4F16 expression was not affected by LPS or clofibrate in both (+/+) and (−/−) mice. In contrast, hepatic expressions of CYP4F15 and CYP4F16 were reduced significantly in (+/+) mice, but much less in (−/−) mice, suggesting that PPARα is partially responsible for this down-regulation. Clofibrate treatment reduced the expression of CYP4F16 in liver, but has no effect on CYP4F15 and PPARα does not have a role in hepatic CYP4F expression regulated by clofibrate. In general, CYP4Fs are regulated in an isoform-, tissue- and species-specific manner. ^ A human CYP4F isoform, CYP4F11, was isolated. The genomic structure was also solved by using database mining and bioinformatics tools. Localization of CYP4F11 to chromosome 19, 16 kb upstream of CYP4F2, suggests that human CYP4F genes may form a cluster on chromosome 19. This novel human 4F is highly expressed in liver, as well as in kidney, heart and skeletal muscle. Further study of the activity and gene regulation on CYP4F11 will provide us more insights into the physiological functions of CYP4F subfamily. ^

The characterization of mouse carboxypeptidase N small subunit gene structure and presence in developing embryos

Carboxypeptidase N (CPN) is a plasma zinc metalloprotease, which consists of two enzymatically active small subunits and two large subunits that protect the protein from degradation. CPN cleaves carboxy-terminal arginines and lysines from peptides found in the bloodstream such as complement anaphylatoxins, kinins, and creatine kinase MM. In this study, the mouse CPN small subunit (CPN1) coding region, gene structure, and chromosomal location were characterized and the expression of CPN1 was investigated in mouse embryos at different stages of development. The CPN1 gene, which was approximately 29 kb in length, contained nine exons and localized to mouse chromosome 19D2. The fifth and sixth exons of CPN1 encoded the amino acids necessary for substrate binding and catalytic activity. CPN1 RNA was expressed predominately in adult liver and contained a 1371 bp open reading frame encoding 457 amino acids. In the mouse embryo, CPN1 RNA was observed at 8.5 days post coitus (dpc), while its protein was detected at 10.5 dpc. In situ hybridization of the fetal liver detected CPN1 RNA in erythroid progenitor cells at 10.5, 13.5, and 16.5 dpc and in hepatocytes at 16.5 dpc. This was compared to the expression of the complement component C3, the parent molecule of complement anaphylatoxin C3a. Consistently throughout the experiments, CPN1 message and protein preceded the expression of C3. To obtain a better understanding of the biological significance of CPN1 in vivo, studies were initiated to produce a genetically engineered mouse in which the CPN1 gene was ablated. To facilitate this project a targeting vector was constructed by removing the functionally important fifth and sixth exons of the CPN1 gene. Collectively, these studies have: (1) provided important detailed information regarding the structure and organization of the murine CPN1 gene, (2) yielded insights into the developmental expression of mouse CPN1 in relationship to C3 expression, and (3) set the stage for the generation of a CPN1 “knock-out” mouse, which can be used to determine the biological significance of CPN1 in both normal and diseased conditions. ^

Prevalence and risk factors for polyomavirus reactivation in solid-organ transplantation

Background. Polyomavirus reactivation is common in solid-organ transplant recipients who are given immunosuppressive medications as standard treatment of care. Previous studies have shown that polyomavirus infection can lead to allograft failure in as many as 45% of the affected patients. Hypothesis. Ubiquitous polyomaviruses when reactivated by post-transplant immunosuppressive medications may lead to impaired renal function and possibly lower survival prospects. Study Overview. Secondary analysis of data was conducted on a prospective longitudinal study of subjects who were at least 18 years of age and were recipients of liver and/or kidney transplant at Mayo Clinic Scottsdale, Arizona. Methods. DNA extractions of blinded urine and blood specimens of transplant patients collected at Mayo Clinic during routine transplant patient visits were performed at Baylor College of Medicine using Qiagen kits. Virologic assays included testing DNA samples for specific polyomavirus sequences using QPCR technology. De-identified demographic and clinical patient data were merged with laboratory data and statistical analysis was performed using Stata10. Results. 76 patients enrolled in the study were followed for 3.9 years post transplantation. The prevalence of BK virus and JC virus urinary excretion was 30% and 28%. Significant association was observed between JC virus excretion and kidney as the transplanted organ (P = 0.039, Pearson Chi-square test). The median urinary JCV viral loads were two logs higher than those of BKV. Patients that excreted both BKV and JCV appeared to have the worst renal function with a mean creatinine clearance value of 71.6 millimeters per minute. A survival disadvantage was observed for dual shedders of BKV and JCV, log-rank statistics, p = 0.09; 2/5 dual-shedders expired during the study period. Liver transplant and male sex were determined to be potential risk factors for JC virus activation in renal and liver transplant recipients. All patients tested negative for SV40 and no association was observed between polyomavirus excretion and type of immunosuppressive medication (tacrolimus, mycophenolate mofetil, cyclosporine and sirolimus). Conclusions. Polyomavirus reactivation was common after solid-organ transplantation and may be associated with impaired renal function. Male sex and JCV infection may be potential risk factors for viral reactivation; findings should be confirmed in larger studies.^

Role of ovarian cancer antigen CA125/MUC16 in development and cancer

Cancer antigen 125 (CA125) is a tumor antigen that is routinely used to monitor the disease progress and the outcome of treatment in ovarian cancer patients. Elevated serum levels of CA125 are detected in over 80% of epithelial ovarian cancer patients. CA125 is a high molecular weight (>1M Dalton) mucin-type glycoprotein encoded by the MUC16 gene on human chromosome 19. Although MUC16 has served as the best serum marker for monitoring growth of ovarian cancer, roles for MUC16 in normal physiology and ovarian cancer are largely unknown. To understand the biological functions of MUC16, I characterized a mouse Muc16 homolog on chromosome 9 by means of expression pattern profiling, phenotype analysis of Muc16 knockout mice, and in vitro and in vivo studies of Muc16 null transformed ovarian surface epithelial (OSE) cells. ^ The mouse Muc16 homolog shares a conserved genomic structure with human MUC16. In addition to being expressed in mouse ovarian cancer, mouse Muc16 mRNA and protein were expressed in the mesothelia covering the heart, lung, ovary, oviduct, spleen, testis, and uterus. The conserved genomic structure and expression pattern of mouse Muc16 to human MUC16 suggests that mouse Muc16 is the ortholog of human MUC16. To understand the biological functions of Muc16, I generated Muc16 knockout mice. Muc16 knockout mice were viable, fertile and normal by one year of age. However, between 18 and 24 months of age, Muc16 knockout mice developed various tissue abnormalities such as ovarian cysts and tumors of the liver and other peritoneal organs. To determine the role of MUC16 in ovarian cancer progression, I established Muc16 null transformed ovarian surface epithelial (OSE) cell lines, following the same method to develop mouse model of epithelial ovarian cancer (Orsulic et al., 2002). Loss of Muc16 did not affect cell morphology, cell proliferation rate, or tumorigenic potential. However, Muc16-null OSE cells showed decreased attachment to extracellular matrix proteins as well as to primary mouse peritoneal mesothelial cells. Peritoneal mesothelia are the most frequent implantation sites of ovarian cancer. Furthermore, a pilot transplantation assay suggests that Muc16 null transformed OSE cells formed less disseminated tumors in the peritoneal cavity compared to wild-type OSE cells. ^ In conclusion, these results demonstrate that MUC16 is not required for normal mouse development or reproduction, but plays important roles in tissue homeostasis, ovarian cancer cell adhesion and dissemination. This study provides the first in vivo evidence of the roles of MUC16 in development, as well as ovarian cancer progression and dissemination. These studies offer valuable insights into possible mechanisms of ovarian cancer development and potential molecular targets for ovarian cancer treatment. ^

Evaluation of oxidative damage and renal distal tubule cell stress response following exposure to lindane

Lindane, or γ-hexachlorocyclohexane, is a chlorinated hydrocarbon pesticide that was banned from U.S. production in 1976, but until recently continued to be imported and applied for occupational and domestic purposes. Lindane is known to cause central nervous system (CNS), immune, cardiovascular, reproductive, liver, and kidney toxicity. The mechanism for which lindane interacts with the CNS has been elucidated, and involves antagonism of the γ-aminobutyric acid/benzodiazepine (GABAA/BZD) receptor. Antagonism of this receptor results in the inhibition of Cl- channel flux, with subsequent convulsions, seizures, and paralysis. This response makes lindane a desirable defense against arthropod pests in agriculture and the home. However, formulation and application of this compound can contribute to human toxicity. In conjunction with this exposure scenario, workers may be subject to both heat and physical stress that may increase their susceptibility to pesticide toxicity by altering their cellular stress response. The kidneys are responsible for maintaining osmotic homeostasis, and are exposed to agents that undergo urinary excretion. The mechanistic action of lindane on the kidneys is not well understood. Lindane, in other organ systems, has been shown to cause cellular damage by generation of free radicals and oxidative stress. Previous research in our laboratory has shown that lindane causes apoptosis in distal tubule cells, and delays renal stress response under hypertonic stress. Characterizing the mechanism of action of lindane under conditions of physiologic stress is necessary to understand the potential hazard cyclodiene pesticides and other organochlorine compounds pose to exposed individuals under baseline conditions, as well as under conditions of physiologic stress. We demonstrated that exposure to lindane results in oxidative damage and dysregulation of glutathione response in renal distal tubule (MDCK) cells. We showed that under conditions of hypertonic stress, lindane-induced oxidative stress resulted in early onset apoptosis and corresponding down-regulated expression of the anti-apoptotic protein, Bcl-xL. Thus, the interaction of lindane with renal peripheral benzodiazepine receptors (PBR) is associated with attenuation of cellular protective proteins, making the cell more susceptible to injury or death. ^

2005 ACIP recommendations effect on newborn hepatitis B vaccination rates and the factors affecting the successful implementation of the recommendations in the US

Background. Hepatitis B virus infection is one of major causes of acute and chronic hepatitis, cirrhosis of the liver, and primary hepatocellular carcinoma. Hepatitis B and its long term consequences are major health problems in the United States. Hepatitis B virus can be vertically transmitted from mother to infant during birth. Hepatitis B vaccination at birth is the most effective measure to prevent the newborn from HBV infection and its consequences, and is part of any robust perinatal hepatitis B prevention program following ACIP recommendations. Universal vaccination of the new born will prevent HBV infection during early childhood and, assuming that children receive the three dosages of the vaccine, it will also prevent adolescent and adult infections. Hepatitis B vaccination is now recommended as part of a comprehensive strategy to eliminate HBV transmission in the United States. ^ Objective. (1)To assess if the hepatitis B vaccination rates of newborn babies have improved after the 2005 ACIP recommendations. (2) To identify factors that affects the implementation of ACIP recommendation for hepatitis B vaccination in newborn babies. These factors will encourage ongoing improvement by identifying successful efforts and pinpointing areas that fall short and need attention. Additional focus areas may be identified to accelerate progress in eliminating perinatal HBV transmission.^ Methods. This review includes information from all pertinent articles, reviews, National immunization survey (NIS) surveys, reports, peer reviewed literature and web sources that were published after 1991.The key words to be used for selecting the articles are: "Perinatal Hepatitis B Prevention program", "Universal Hepatitis B vaccination of newborn babies", "ACIP Recommendations." The data gathered will be supplemented with an analysis of vaccination rates using the National Immunization Survey (NIS) birth dose coverage data.^ Results. The data collected in the NIS of 2009 reveals that the national coverage for birth dose of HepB increased to 60.8% from 50.1% in 2006. The largest increase observed for the birth dose in the past 5 years is from 2008 which increased from 55.3 % to 60.8% in 2009. By state, coverage ranged from 22.8% in Vermont to 80.7% in Michigan. %. Overall, in 2009 the estimated vaccination rates are in higher ranges for most states compared to the estimated vaccination rates in 2006. States vary widely in hepatitis B vaccination rates and in their compliance with the 2005 ACIP recommendation. There are many factors at various stages that might affect the successful implementation of the new ACIP recommendation as revealed in literature review. ^ Conclusions. HBV perinatal transmission can be eliminated, but it requires identifying the gaps and measures taken to increase the current vaccination coverage, ensuring timely administration of post exposure immunoprophylaxis and continued evaluations of the impact of immunization recommendations.^

Lifetime prevalence and risk factors for cancer in a Mexican American population with severe health disparities: The Cameron County Hispanic Cohort

Retrospective data from the Cameron Country Hispanic Cohort (1) were analyzed to assess the burden of cancer in the Mexican American population living in Brownsville TX. Data provided by the study participants for themselves and their parents and other extended relatives on cancer and related risk factors were used to determine both the prevalence of cancer and these risk factors as well as any associations between them. Lifetime incidence of cancer among the study participants was of 2.8%. Lifetime incidence of cancer among the parents of the study population was calculated for cancer in general and for specific cancer sites to determine the ranking of occurrence of each type of cancer. Some cancer types in this population were ranked higher than what would be expected when compared with national data from Hispanics in the U.S, these were: Liver cancer (3rd vs. 7th nationally in males and 6th vs. 13th nationally in females), stomach cancer (4th vs. 8th nationally in males and 5th vs. 11th nationally in females) and ovarian cancer (3rd vs. 8th nationally in females). A significant association with cancer was found for being born in the United States compared to being born elsewhere (O.R. 1.62, 95% C.I. 1.01–2.60) among study participants and the same association was also found between birth of parents in the United States regardless of gender for cancers in general (O.R. 1.38 95% C.I. 1.12–1.70), stomach cancer (O.R. 1.92 95% C.I. 1.01–3.67) and colorectal cancer (O.R. 2.93 95% C.I. 1.28–6.72). Having been born in the United States and having a family history of cancer was also found to be significantly associated with other risk factors for cancer such as obesity, diabetes and insulin resistance, both among the parents and the participant population, suggesting these interactions are complex. These high rates of cancer and particular prominence of less usual cancer such as liver and ovary in health disparities warrant evaluation of early detection strategies.^

Assessing high-priority mixtures: A review of methanol as influenced by ethanol

The intent of this research was to identify the level of risk methanol posed to a fetus during an ethanol co-exposure. This investigation was prompted by the known competitive inhibition properties of ethanol and the developmental toxicity of methanol. Integrated into this research was the practicality necessitated by regulatory processes, namely: does the risk justify the expense of additional research. To this end, the scope and nature of exposures were summarized to illustrate the ubiquity of these chemicals and the potential for dual exposure. Similarly, severity of outcome was evaluated by systematically reviewing the LOAELs, NOAELs, and statistical significance contained in methanol-induced developmental studies. Results. Blood methanol levels corresponding to developmental effects in laboratory studies were found to be substantially higher than the blood methanol levels predicted in high-risk methanol-ethanol exposure scenarios. This indicates that ethanol would not likely exacerbate methanol toxicity to the point of teratogenicity; however, it is important to note that the developmental toxicity of ethanol—an established human teratogen—was not included in the evaluation. Ethanol's contribution as a developmental toxicant rather than merely as an attenuator of methanol toxicity undermines the severity of effects possible from this chemical combination. Therefore further evaluation is needed to assess the developmental toxicities following dual exposures before rendering methanol and ethanol a high-priority mixture.^

{\it cis\/} -acting elements and {\it trans\/} -acting factors that control serum amyloid A gene expression during inflammation

To understand how the serum amyloid A (SAA) genes are regulated, the cis-acting elements and trans-acting factors involved in the regulation of mouse SAA3 and rat SAA1 genes expression during inflammation were analyzed.^ To identify DNA sequences involved in the liver-specific expression of the mouse SAA3 gene, the 5$\sp\prime$ flanking region of this gene was analyzed by transient transfection studies. Results suggest that C/EBP, a liver-enriched transcription factor, plays an important role for the enhanced expression of the mouse SAA3 gene in hepatocytes.^ Transfection studies of the regulation of the expression of rat SAA1 gene indicated that a 322 bp fragment ($-$304 to +18) of the gene contains sufficient information for cytokine-induced expression of the reporter gene in a liver cell-specific manner. Further functional analysis of the 5$\sp\prime$ flanking region of the rat SAA1 gene demonstrated that a 65 bp DNA fragment ($-$138/$-$73) can confer cytokine-inducibility onto a heterologous promoter both in liver and nonliver cells. DNase I footprint and gel retardation assays identified five putative cis-regulatory elements within the 5$\sp\prime$ flanking region of the gene: one inducible element, a NF$\kappa$B binding site and four constitutive elements. Two constitutive elements, footprint regions I and III, were identified as C/EBP binding sites with region III having over a 10-fold higher affinity for C/EBP binding than region I. Functional analysis of the cis-elements indicated that C/EBP(I) and C/EBP(III) confer liver cell-specific activation onto a heterologous promoter, while sequences corresponding to the NF$\kappa$B element and C/EBP(I) impart cytokine responsiveness onto the heterologous promoter. These results suggest that C/EBP(I) possesses two functions: liver-specific activation and cytokine responsiveness. The identification of two cytokine responsive elements (NF$\kappa$B and C/EBP(I)), and two liver-specific elements (C/EBP(I) and C/EBP(III)) implies that multiple cis-acting elements are involved in the regulation of the expression of the rat SAA1 gene. The tissue-specific and cytokine-induced expression of rat SAA1 gene is likely the result of the interactions of these cis-acting elements with their cognate trans-acting factors as well as the interplay between the different cis-acting elements and their binding factors. (Abstract shortened with permission of author.) ^