IL-18, TNF, and IFN-γ alleles and genotypes are associated with susceptibility to chronic hepatitis B infection and severity of liver injury.

This study evaluated the association of polymorphisms in the IL-18 (-607C/A and -137C/G), IFNγ (+874 A/T), and TNF (-238 A/G and -308 A/G) genes with susceptibility to HBV infection and severity of liver injury. A total of 259 chronic HBV-infected patients followed at the University Hospital, Faculty of Medicine of Ribeirão Preto, São Paulo, Brazil, and 202 healthy individuals were studied. Four Single Nucleotide Polymorphisms (SNPs) were amplified by Polymerase Chain Reaction (PCR). Liver biopsy was performed in 212 HBV-infected patients and classified according to severity of liver fibrosis (scores 0-4) and necroinflammatory activity (HAI scores 0-18). TNF-308*A allele (P < 0.001; OR = 2.16) and TNF -308 AA genotype (P = 0.026; OR = 5.43) were associated with susceptibility to HBV infection. An association was found between severe liver fibrosis when compared to mild fibrosis and the following polymorphisms: Alleles IL-18 -137*G (P = 0.004; OR = 3.45), TNF -308*A (P < 0.001; OR = 3.39), and IFNγ +874*T (P = 0.029; OR = 1.85) and IL-18 -137 GG genotype (P = 0.009; OR = 3.70). No significant association was found between IL-18 (-607 A/C) polymorphism and severity of liver fibrosis. Alleles IL-18 -137*G (P = 0.028; OR = 2.64) and TNF-308*A (P = 0.002; OR = 3.06) and IL-18 -137 GG genotype (P = 0.011; OR = 4.20) were associated with severe necroinflammatory activity (HAI>12) when compared to mild necroinflammatory activity (HAI 1-8). The results suggest that IL-18 -137C/G, TNF-308 G/A and IFNγ +874 A/T SNPs were associated to more severe liver injury in chronic HBV infection. TNF -308*A allele and TNF -308 AA genotype could play a role in the susceptibility to HBV infection.

Factors associated with spontaneous HBsAg clearance in chronic hepatitis B patients followed at a university hospital.

INTRODUCTION: Few studies have evaluated the factors involved in the spontaneous HBsAg seroclearance in patients with chronic hepatitis B (HBV) followed up on a long-term basis from areas with a low prevalence of HBV infection. We aimed to determine the rate of spontaneous HBsAg seroclearance and the factors related to it in patients with chronic HBV infection followed up at the Hepatitis Outpatient Clinic of HCFMRP from 1992-2008. MATERIALS AND METHODS: A total of 548 patients with chronic HBV infection (366 with chronic hepatitis B and 182 inactive carriers) were followed for 15 years and 9 months with an annual measurement of HBV-DNA, ALT, AST and GGT (average of 4 annual determinations) and serology (HBsAg, HBeAg, Anti-HBeAg and Anti-HBsAg). RESULTS: Spontaneous HBsAg seroclearance occurred in 40 patients (7.3%) with a mean age of 46.0 ± 14.4 years, corresponding to an annual rate of 0.7%.The factors related to spontaneous HBsAg seroclearance were inactive carrier status (67.5 vs. 32.5%, p = 0.000191) and age of more than 40 years (p = 0.0007). There was no difference in the rate of spontaneous HBsAg seroclearance when comparing males and females (p = 0.383). Patients with spontaneous HBsAg seroclearance did not progress to more severe forms of the disease during follow-up. CONCLUSION: Spontaneous HBsAg seroclearance has a favorable long-term prognosis in patients with chronic HBV infection. HBsAg seroclearance occurred at rates compatible with low prevalence areas and was associated with low serum HBV-DNA levels and an age older than 40 years.

Methylenetetrahydrofolate reductase gene polymorphism and serum homocysteine levels in nonalcoholic fatty liver disease.

BACKGROUND/AIMS: Nonalcoholic fatty liver disease (NAFLD) is a metabolic disorder characterized by hepatic fat accumulation in the absence of alcohol consumption. Hyperhomocysteinemia is considered an independent risk factor for liver diseases, and the genetic polymorphisms C677T and A1298C in the MTHFR gene have been linked to hyperhomocysteinemia. The purpose of this study was to investigate serum homocysteine (Hcy) concentrations and the MTHFR C677T and A1298C polymorphisms as risk factors for the development of NAFLD. METHODS: One hundred and thirty-four Brazilian patients with biopsy-proven NAFLD and 134 healthy controls were recruited. The MTHFR C677T and A1298C polymorphisms were detected through polymerase chain reaction restriction fragment length polymorphism. Serum Hcy levels were determined by chemiluminescence. RESULTS: Serum Hcy levels were higher in NAFLD patients as compared to control subjects, but there were no differences between patients with steatosis and nonalcoholic steatohepatitis. The NAFLD and control groups did not differ in genotypic and allelic frequencies of the MTHFR C677T and A1298C polymorphisms, either. Elevated plasma Hcy levels were positively correlated with age in the NAFLD subjects. CONCLUSION: The MTHFR C677T and A1298C polymorphisms are not genetic risk factors for the development of NAFLD. Higher Hcy levels exist in NAFLD subjects, but they are not associated with liver disease severity.

Light and moderate doses of ethanol in chemical carcinogenesis of the colon in rats.

The aberrant crypt foci (ACF), cyclooxygenase 2 (COX-2), and the proliferating cell nuclear antigen (PCNA) are putative biomarkers for colon cancer. To study the association between light (1 g of ethanol/kg bw) and moderate (3 g of ethanol/kg bw) doses of ethanol with the chemical carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), Wistar rats were divided into 6 groups. The colon fragments were collected for histochemical and immunohistochemical analyses, and the liver samples were collected for oxidative stress analysis, with products of lipid peroxidation (malondialdehyde), antioxidant enzymes (glutathione), and vitamin E. The association of light and moderate doses of ethanol with MNNG did not present differences in the oxidative parameters. However, a reduction in vitamin E levels in the carcinogen groups was observed. The association induced a reduction of the COX-2 and PCNA expression. The number of ACF in the group that received a light dose of ethanol had lower rates, while the group that received a moderate dose had the highest rates compared to the control MNNG, demonstrating that the light dose of ethanol could have a protective effect, while the moderate dose could represent a risk during chemical carcinogenesis in rats.

Cancer stem cell immunophenotypes in oral squamous cell carcinoma.

BACKGROUND: The presence of cancer stem cell (CSC) antigens can be evidenced in some human tumors by phenotypic analysis through immunostaining. This study aims to identify a putative CSC immunophenotype in oral squamous cell carcinoma (OSCC) and determine its influence on prognosis. METHODS: The following data were retrieved from 157 patents: age, gender, primary anatomic site, smoking and alcohol intake, recurrence, metastases, histologic classification, treatment, disease-free survival (DFS), and overall survival (OS). An immunohistochemical study for CD44 and CD24 was performed in a tissue microarray of 157 paraffin blocks of OSCCs. RESULTS: In univariate analysis, the immunostaining pattern showed significant influences in relation to OS for alcohol intake and treatment, as well as for the CD44(+) and CD44(-) /CD24(-) immunophenotypes. The multivariate test confirmed these associations. CONCLUSIONS: Based on our results, the CD44 immunostaining and the absence of immunoexpression of these two investigated markers can be used in combination with other clinicopathologic information to improve the assessment of prognosis in OSCC.

Myenteric denervation downregulates galectin-1 and -3 expression in gastric carcinogenesis.

BACKGROUND: This study evaluated the galectin-1 and -3 expression during N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis in denervated rat stomachs using benzalkonium chloride. METHOD: Four experimental situations were evaluated: nondenervated and denervated stomachs without lesions and nondenervated and denervated stomachs with lesions. Sections of the pyloric region were stained with toluidine blue and incubated with mouse monoclonal anti-Gal-1 and rabbit polyclonal anti-Gal-3 for histopathological and immunohistochemical analysis, respectively. RESULT: MNNG caused the development of benign and malignant epithelial lesions, which were more pronounced in nondenervated stomachs with lesions and accompanied by inflammatory cell-enriched stroma. By immunostaining, the epithelial cells, blood vessels, muscle layer, and myenteric plexus were Gal-1 and -3 positive. Gal-3 was also detected in the gastric crypts, mucus secretion, and fibroblasts of pyloric fragments. Development of lesions in denervated stomachs was associated with a significant decrease in Gal-1 and -3 expression in epithelial cells, mast cells, and neutrophil cytoplasm, compared with that of nondenervated stomach lesions (P < 0.01; P < 0.001; P < 0.001, respectively). CONCLUSION: These results demonstrate that myenteric denervation downregulates endogenous Gal-1 and -3 expression, which might inhibit tumor development in this experimental model.

Effects of myenteric denervation on extracellular matrix fibers and mast cell distribution in normal stomach and gastric lesions.

BACKGROUND: In this study the effect of myenteric denervation induced by benzalconium chloride (BAC) on distribution of fibrillar components of extracellular matrix (ECM) and inflammatory cells was investigated in gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Rats were divided in four experimental groups: non-denervated (I) and denervated stomach (II) without MNNG treatment; non-denervated (III) and denervated stomachs (IV) treated with MNNG. For histopathological, histochemical and stereological analysis, sections of gastric fragments were stained with Hematoxylin-Eosin, Picrosirius-Hematoxylin, Gomori reticulin, Weigert's Resorcin-Fuchsin, Toluidine Blue and Alcian-Blue/Safranin (AB-SAF). RESULTS: BAC denervation causes an increase in the frequency of reticular and elastic fibers in the denervated (group II) compared to the non-denervated stomachs (group I). The treatment of the animals with MNNG induced the development of adenocarcinomas in non-denervated and denervated stomachs (groups III and IV, respectively) with a notable increase in the relative volume of the stroma, the frequency of reticular fibers and the inflammatory infiltrate that was more intense in group IV. An increase in the frequency of elastic fibers was observed in adenocarcinomas of denervated (group IV) compared to the non-denervated stomachs (group III) that showed degradation of these fibers. The development of lesions (groups III and IV) was also associated with an increase in the mast cell population, especially AB and AB-SAF positives, the latter mainly in the denervated group IV. CONCLUSIONS: The results show a strong association in the morphological alteration of the ECM fibrillar components, the increased density of mast cells and the development of tumors induced by MNNG in the non-denervated rat stomach or denervated by BAC. This suggests that the study of extracellular and intracellular components of tumor microenvironment contributes to understanding of tumor biology by action of myenteric denervation.

A BALB/c mouse model shows that liver involvement in dengue disease is immune-mediated.

In the present study, BALB/c mice were used to develop a model for the hepatic injury associated to dengue infection. Histological analysis after subcutaneous inoculation with a low viral dose of dengue-2 virus showed Kupffer cell hyperplasia and an increased inflammatory cellular infiltrate next to the bile ducts on days 5, 7 and 14 post-inoculation, mainly characterized by the presence of mononuclear cells. The liver mRNA transcription level of IL-1ß was highest on the 5th day post-infection (p.i.) and decreased by the 21st day, TNF-α showed a peak of mRNA transcription after 14 days p.i. coinciding with the regression of cellular infiltrates and elevated expression of TGF-ß mRNA. Serum AST and ALT levels were slightly elevated at 7 and 14 days post-infection. Dengue-2 RNA levels were undetectable in the liver on any of the days following inoculation. Our observations suggest that, as it is true for humans, the animals undergo a transient and slight liver inflammation, probably due to local cytokine production and cellular infiltration in the liver.

Hepatic ballooning degeneration: a new feature of the refeeding syndrome in rats.

AIM OF THE STUDY: Hepatic changes have been described during the refeeding syndrome due to increase in enzymes and hepatomegaly; however, they have not been properly described. Thus, the objective of this study was to investigate the hepatic histological characteristics and biochemical markers of hepatic steatosis in Wistar rats with refeeding syndrome. MATERIAL AND METHODS: Thirty male Wistar rats were allocated to one of three groups: C, F or R. The animals from group C received an AIN-93 diet for 96 hours, and were then sacrificed. Animals allocated to group F were fasted for 48 hours and sacrificed. Animals from group R were also fasted for 48 hours, but were refed for another 48 hours, with AIN-93. The liver, blood and epididymal and retroperitoneal fats were collected. RESULTS: Data obtained in groups F and R show the changes observed in refeeding syndrome, during starvation and refeeding. The serum glucose, magnesium, potassium and phosphorus, in group F, decreased. There was no evidence of hepatic steatosis. Hypophosphatemia, hypomagnesemia and hypokalemia were also observed in group R, confirming refeeding syndrome. The main histological characteristic, in this group, was the extensive presence of ballooning degeneration. This is the first article that has detected such change in liver structure, due to refeeding syndrome. The possible causes are: retention of sodium, causing whole body edema; and/or dysfunction of the sodium/potassium pump of the hepatocytes, as a result of hypophosphatemia. CONCLUSIONS: This is the first description of an animal model of hepatic severe ballooning degeneration induced due to refeeding syndrome.

Fluorescence spectroscopy to diagnose hepatic steatosis in a rat model of fatty liver.

BACKGROUND: Steatosis is diagnosed on the basis of the macroscopic aspect of the liver evaluated by the surgeon at the time of organ extraction or by means of a frozen biopsy. AIM: In the present study, the applicability of laser-induced fluorescence (LIF) spectroscopy was investigated as a method for the diagnosis of different degrees of steatosis experimentally induced in rats. MATERIAL AND METHODS: Rats received a high-lipid diet for different periods of time. The animals were divided into groups according to the degree of induced steatosis diagnosis by histology. The concentration of fat in the liver was correlated with LIF by means of the steatosis fluorescence factor (SFF). RESULTS: The histology classification, according to liver fat concentration was, Severe Steatosis, Moderate Steatosis, Mild Steatosis and Control (no liver steatosis). Fluorescence intensity could be directly correlated with fat content. It was possible to estimate an average of fluorescence intensity variable by means of different confidence intervals (P=95%) for each steatosis group. SFF was significantly higher in the Severe Steatosis group (P<0.001) compared with the Moderate Steatosis, Mild Steatosis and Control groups. CONCLUSION: The various degrees of steatosis could be directly correlated with SFF. LIF spectroscopy proved to be a method capable of identifying the degree of hepatic steatosis in this animal model, and has the potential of clinical application for non-invasive evaluation of the degree of steatosis.

Effect of NFkappaB inhibition by CAPE on skeletal muscle ischemia-reperfusion injury.

BACKGROUND/AIMS: Nuclear factor kappa B (NFkappaB) plays important role in the pathogenesis of skeletal muscle ischemia/reperfusion (I/R) injury. Caffeic acid phenyl ester (CAPE), a potent NFkappaB inhibitor, exhibits protective effects on I/R injury in some tissues. In this report, the effect of CAPE on skeletal muscle I/R injury in rats was studied. METHODS: Wistar rats were submitted to sham operation, 120-min hindlimb ischemia, or 120-min hindlimb ischemia plus saline or CAPE treatment followed by 4-h reperfusion. Gastrocnemius muscle injury was evaluated by serum aminotransferase levels, muscle edema, tissue glutathione and malondialdehyde measurement, and scoring of histological damage. Apoptotic nuclei were determined by a terminal uridine deoxynucleotidyl transferase dUTP nick end labeling assay. Muscle neutrophil and mast cell accumulation were also assessed. Lipoperoxidation products and NFkappaB were evaluated by 4-hydroxynonenal and NFkappaB p65 immunohistochemistry, respectively. RESULTS: Animals submitted to ischemia showed a marked increase in aminotransferases after reperfusion, but with lower levels in the CAPE group. Tissue glutathione levels declined gradually during ischemia to reperfusion, and were partially recovered with CAPE treatment. The histological damage score, muscle edema percentage, tissue malondialdehyde content, apoptosis index, and neutrophil and mast cell infiltration, as well as 4-hydroxynonenal and NFkappaB p65 labeling, were higher in animals submitted to I/R compared with the ischemia group. However, the CAPE treatment significantly reduced all of these alterations. CONCLUSIONS: CAPE was able to protect skeletal muscle against I/R injury in rats. This effect may be associated with the inhibition of the NFkappaB signaling pathway and decrease of the tissue inflammatory response following skeletal muscle I/R.

The protective effect of CAPE on hepatic ischemia/reperfusion injury in rats.

BACKGROUND/AIMS: The transcription factor nuclear factor-kappa B (NF-kappaB) exerts a pivotal role in the pathogenesis of hepatic ischemia/reperfusion (I/R) injury. Caffeic acid phenyl ester (CAPE), a potent and specific NF-kappaB inhibitor, presents protective effects on I/R injury in some tissues. This study aimed to evaluate the effect of CAPE on hepatic I/R injury in rats. MATERIALS AND METHODS: Wistar rats were submitted to a sham operation, 60 min ischemia, or 60 min ischemia plus saline or CAPE treatment followed by 6 h reperfusion. Liver tissue injury was evaluated by alanine aminotransferase, aspartate aminotransferase, and tissue glutathione measurement, and histological damage score. Apoptotic hepatocytes were determined by the transferase-mediated dUTP-biotin nick-end labeling assay. Hepatic neutrophil accumulation was assessed by the naphthol method. Lipid peroxidation and NF-kappaB activation were evaluated by 4-hydroxynonenal and NF-kappaB p65 immunohistochemistry, respectively. RESULTS: Animals submitted to ischemia showed a marked increase of alanine aminotransferase and aspartate aminotransferase after reperfusion, but with lower levels in CAPE group. Tissue glutathione content declined gradually during ischemia to reperfusion and was partially recovered with CAPE treatment. The histological damage score, apoptosis index, and neutrophil infiltration, as well as 4-hydroxynonenal and NF-kappaB p65 nuclear labeling, were higher in the liver of animals submitted to I/R compared to the ischemia group. However, the CAPE treatment significantly reduced all of these alterations. CONCLUSIONS: CAPE was able to protect the liver against normothermic I/R injury in rats. This effect may be associated with the inhibition of the NF-kappaB signaling pathway and decrease of the acute inflammatory response following I/R in the liver.

Effect of a thrombin receptor (protease-activated receptor 1, PAR-1) gene polymorphism in chronic hepatitis C liver fibrosis.

BACKGROUND AND AIM: Tissue injury leads to activation of coagulation and generation of thrombin. Inhibition of thrombin receptor protease-activated receptor 1 (PAR-1) has been shown to reduce liver fibrosis in animals. This study aimed to evaluate the effect of PAR-1 gene polymorphism on rate of liver fibrosis (RF) in chronic hepatitis C. METHODS: Polymorphisms studied: C > T transition 1426 bp upstream of translation start site (-1426C/T), 13 bp repeat of preceding -506 5'-CGGCCGCGGGAAG-3' sequence (-506I/D), and A > T transversion in intervening sequence (IVS) 14 bp upstream of exon-2 start site (IVS-14A/T). A total of 287 European and 90 Brazilian patients were studied. RESULTS: 1426C/T polymorphism: There was a trend to higher RF in patients with the TT genotype (P = 0.06) and an association between genotype CC and slow fibrosis (P = 0.03) in Europeans. In males, RF was significantly higher in those with the TT genotype compared to CT (P = 0.003) and CC (P = 0.007). There was a significant association between TT and fast fibrosis (P = 0.04). This was confirmed in an independent cohort of Brazilians where RF was higher in TT than in CC (P = 0.03). Analysis of -506I/D showed no difference in RF and distribution of slow/fast fibrosis among different genotypes in both populations. Analysis of IVS-14A/T showed no difference between genotypes. CONCLUSION: In conclusion, these findings suggest that PAR-1 receptor polymorphisms influence the progression of liver fibrosis.

Differential distribution of some extracellular matrix fibers in an experimentally denervated rat megaileum.

Absence of enteric neurons is associated with thickening of the intestinal muscularis externa in Chagas' disease. The thickening is due to hyperplasia and hypertrophy of the smooth muscle cells and increased extracellular matrix components. The influence of the nervous system on the structure of the smooth muscle cells and its associated matrix has been poorly investigated. An experimental model of denervation of the ileum in rats was performed by application of the surfactant agent benzalkonium chloride that selectively destroys the myenteric plexus. Three months later, ileal tissue samples were obtained and studied by histochemistry and transmission electron microsocopy. Sham operated rats were used as controls. The diameter of collagen fibrils was evaluated in electron micrographs. The histopathological analysis showed thickening of the muscular layer. The thin and weakly arranged collagen and reticulin fibers surrounding the smooth muscle cells, observed in control cases by Picrosirius polarization (PSP) stain method, corresponded to a population of loosely packed thin collagen fibrils of uniform diameters (mean=29.16 nm) at the ultrastructural level. In contrast, the thick and strongly birefringent fibers around the muscle cells, observed in the treated group, stained by PSP, corresponded to densely packed thicker fibrils with large variation in diameter (mean=39.41 nm). Comparison of the data demonstrated statistically significant difference between the groups suggesting that the replacement of loosely arranged reticulin fibers by fibrous tissue (with typical collagen fiber), may alter the biomechanical function resulting in impairment of muscular contraction.

Cytomegalovirus in colorectal cancer and idiopathic ulcerative colitis.

Cytomegalovirus (CMV) is a genus in the family Herpesviridae that has been associated with gastrointestinal syndromes. In this work we looked for a possible association of CMV infection with colorectal cancer and ulcerative colitis (UC). Blood and enteric tissue samples of 14 patients with colorectal cancer and of 21 with UC were subjected to a nested-PCR that amplifies part of the gB gene of CMV and also to immunohistochemistry using a specific monoclonal antibody to IE 76 kDa protein of CMV. CMV was detected by nested-PCR in the blood and/or the enteric tissue of nine (64.3%) colorectal cancer and 16 (76.2%) ulcerative colitis patients. In the immunohistochemistry it was observed that 12 (12/21, 57.1%) positive enteric tissue samples of patients with UC and none from patients with colorectal cancer (0/14) were positive to CMV. The positivity of CMV infections in the UC patient group (12/21, 57.1%) showed by both techniques, was significantly higher (p = 0.015) than that observed for colorectal cancer patients (2/14, 14.3%). These results suggest an association of ulcerative colitis with CMV infection of the enteric tissue.

Increase of phosphatidylethanolamine N-methyltransferase activity in the small bowel brush-border membrane after massive intestinal distal resection in rats.

Phosphatidylcholine plays an important role for the structure and function of the cell membrane, and its synthesis from phosphatidylethanolamine is catalyzed by phosphatidylethanolamine N-methyltransferase (PEMT). This study investigates changes in PEMT activity in the intestinal brush border membrane after extensive distal enterectomy (60%) in 40 Wistar rats. Four groups, each of 10 rats, were killed immediately after surgery (day 0) and on the 7th, 14th and 28th day postoperatively. Samples from jejunum were collected for histomorphometry and PEMT activity was determined by measuring the incorporation of [(3)H]-methyl groups from S-adenosyl-L-(methyl-(3)H)-methionine into phospholipids. Enterectomy induced 30%, 48% and 21% increases in the jejunum villus cell population, and 32%, 81%, and 32% in the crypt cell population at postoperative days 7, 14, and 28, respectively. PEMT activity increased 41% at day 14, suggesting functional differentiation, remaining at this level until day 28, when a reduction in the epithelial cell population was observed, thus indicating that adaptation was completed. The observed increase in PEMT-specific activity in the residual intestine suggests that extensive enterectomy stimulates the synthesis of phosphatidylcholine by the PEMT-controlled pathway.

Dehydroepiandrosterone affects Trypanosoma cruzi tissue parasite burdens in rats.

Dehydroepiandrosterone (DHEA), the predominant steroid hormone produced by adrenal glands has significant effects on the immune system. DHEA enhances immune responses against a wide range of viral, bacterial, and parasitic pathogens. In the present study, we investigated the effects of DHEA treatment during the acute phase of experimental Trypanosoma cruzi infection. Male and female Wistar rats were infected with the Y strain of T. cruzi and treated subcutaneously with 40 mg/kg body weight/day of DHEA. Myocardial parasitism and inflammation were always present in the heart during the acute phase, in male and female infected animals, regardless of DHEA treatment, but the numbers of amastigote nests in cardiomyocytes were significantly lower in DHEA-treated rats. At the end of the acute phase, the nests became rare or virtually absent in all experimental infections. Histological analysis of the adrenal glands showed that treated males displayed an absence of parasites. DHEA treatment also resulted in reduced parasitisim of heart and adrenal glands, as indicated by fewer and smaller amastigote burdens, and less inflammatory infiltrate and tissue disorganization. DHEA treatment also resulted in thymic atrophy as measured both by reduced weight and by a reduction in the number of cultured activated thymocytes. In vitro analysis showed the number of activated macrophages was higher in treated animals. Antibody levels were monitored by complement-mediated lysis. Higher titers were observed in females when compared to males; but DHEA treatment enhanced the percentage of lysis for both sexes. These findings suggest that DHEA can play a role in the control of parasite multiplication.

Prognostic significance of p53 and p63 immunolocalisation in primary and matched lymph node metastasis in oral squamous cell carcinoma.

This study evaluates the prognostic significance of p53 and p63 immunolocalisation in oral squamous cell carcinoma samples from 45 matched primary tumors (PT) and lymph node metastases (LNM). Data regarding patient age, gender, primary site, histological differentiation, metastasis, disease-free survival (DFS) and overall survival (OS) were available. p53 and p63 immunolabeling was detected in 17 (37.8%) and 23 (51.1%) of the PT, respectively. For LNM, there was p53 and p63 labeling in 23 (51.1%) and 26 (57.8%) cases, respectively. Most cases showed similar labeling in PT and the corresponding LNM (73.3% for p53 and 53.3% for p63, respectively). No statistically significant associations were found between p53 and p63 immunolabeling and histological differentiation; p63 positive tumors showed higher DFS (p=0.006) and OS (p=0.049); and p53-negative tumors had a higher DFS interval (p=0.009). Our findings suggest that initially p53-negative tumors and initially p63-positive tumors that retain this labeling pattern may follow less aggressive biological courses and present better prognoses.

The HLA-G 14-base pair deletion allele and the deletion/deletion genotype are associated with persistent HBe antigenemia in chronic hepatis B infection.

BACKGROUND AND AIMS: HLA-G has well-recognized immunomodulatory properties, and this molecule is frequently expressed in the livers of hepatitis B virus (HBV)-infected patients. Because the HLA-G 14 bp-insertion/deletion polymorphism (rs371194629) has been associated with the magnitude of HLA-G expression, we evaluated this polymorphism in the recognized evolutionary forms of chronic HBV infection. METHODS: We studied 196 chronic HBV-infected patients (118 HBeAg-negative chronic hepatitis, 53 HBeAg-positive chronic hepatitis and 25 inactive carriers exhibiting low levels of serum HBVDNA and persistently normal ALT levels), and 202 healthy individuals. Chronic hepatitis HLA-G typing was performed using PCR-amplified DNA hybridized with specific primers. RESULTS: The frequencies of the insertion/deletion alleles and genotypes were very similar in patients and controls. After patient stratification according to the evolutionary form of the chronic HBV infection, the frequencies of the deletion allele (P=0.0460; OR=1.26; 95%CI=1.01-1.45) and of the deletion/deletion genotype (P=0.0356; OR=2.08; 95%CI=1.05-4.09) were overrepresented in HBeAg-positive patients when compared to HBeAg-negative patients. No differences were observed when HBV inactive carriers were compared to HBeAg-negative chronic hepatitis patients. CONCLUSIONS: Because the 14-bp deletion allele has been associated with increased HLA-G production and because HLA-G may down regulate the cytotoxic activity of TCD8 and NK cells, patients exhibiting the 14-bp deletion allele at single or double doses are at increased risk for developing chronic forms of HBV associated with persistent viremia and worse prognoses.

Vascular endothelial growth factor expression in the basal subtype of breast carcinoma.

The recognition of subtypes of breast carcinomas based on their molecular features has brought new perspectives in breast cancer research. Some key regulators of angiogenesis and tumor infiltration were evaluated in breast carcinomas of basal phenotype (cytokeratin [CK]5+). Immunohistochemical analysis with 14 primary antibodies was performed in 100 formalin-fixed, paraffin-embedded samples of invasive ductal carcinomas. CK5 correlated with indicators of poor outcome, including precocious age, high histologic grade, lymph node positivity, advanced pathologic stage, negativity for hormonal receptors, and a high proliferative rate (Ki-67 labeling index). CK5 also correlated with vascular endothelial growth factor (VEGF) expression but not with the microvessel density. Considering that VEGF-overexpressing neoplastic mammary cells display increased proliferative activity in vitro regardless of the angiogenic effect of VEGF, the differential expression of VEGF might contribute to the more aggressive behavior of these neoplasms. CK5 correlated with tissue inhibitor of metalloproteinase (TIMP)-1, but not matrix metalloproteinase (MMP)-1, MMP-2, extracellular matrix metalloproteinase inducer, TIMP-2 or plasminogen activator inhibitor, indicating that antiproteolytic stimuli might be preponderant in these neoplasms.