Role of diesel exhaust particles in the induction of allergic asthma to low doses of soybean.

INTRODUCTION: Exposure to environmental pollutants such as diesel exhaust particles (DEP) increases the risk of asthma and asthma exacerbation. However, the exact mechanisms inducing asthma to low doses of allergens remain poorly understood. The present study aimed to analyse the immunomodulatory effect of the inhalation of DEP in a mouse model exposed to non-asthmagenic doses of soybean hull extract (SHE). MATERIAL AND METHODS: BALB/c ByJ mice were randomly divided into four experimental groups. Two groups received nasal instillations of saline and the other two groups received 3 mg ml-1 SHE during 5 days per week for 3 weeks. One group in each pair also received 150 µg of DEP in the same instillations 3 days per week. SHE-specific IgE levels, oxidative stress, leukocyte pattern and optical projection tomography (OPT) imaging studies were assessed. RESULTS: Inhalation of SHE and/or DEP increased levels of H2O2 in BAL, while coexposure to SHE and DEP increased SHE-specific IgE levels in serum. Inhalation of SHE alone increased eosinophils, B cells, total and resident monocytes and decreased levels of NK cells, while inhalation of DEP increased neutrophils and decreased total monocytes. Regarding dendritic cells (DC), the inhalation of SHE and/or DEP increased the total population, while the inhalation of SHE alone increased Th2-related DCs (CD11b + Ly6C-) and decreased tolerogenic DCs (CD11b-Ly6C-). However, coexposure to SHE and DEP increased oxidative stress-sensitive DCs (CD11b-Ly6C+) and decreased Th1-related DCs (CD11b + Ly6C+). As regards macrophages, inhalation of SHE and DEP decreased total and alveolar populations. DEP deposition in lung tissue did not differ between groups. CONCLUSION: Coexposure to DEP activates the asthmatic response to low doses of soy by triggering the immune response and oxidative stress.

Immunomodulatory effect of pigeon serum in an acute and chronic murine model of bird fanciers lung.

INTRODUCTION: Since the immunopathological mechanisms of bird fancier's lung (BFL) are not well known, we created two models of the disease (acute and chronic BFL) to study and compare the pathways involved in its immunopathogenesis. MATERIALS AND METHODS: C57BL/6 mice were used. Two intraperitoneal injections of 100 µL of commercial pigeon serum (PS) or saline (SAL) were administered with an interval of 48 h in between. Subsequently, intranasal instillations of 40 µL of PS or SAL were performed three days a week, for three weeks in the acute model (AC/PS) and for twelve weeks in the chronic model (CR/PS). Total lung capacity (TLC) was assessed. Pulmonary inflammation was evaluated in bronchoalveolar lavage (BAL), and total serum immunoglobulin (Ig) G was measured in serum samples 24 h, 7 days and 14 days after the last exposure. Histological studies of lungs were assessed. RESULTS: A drop in TLC was observed in treated mice. This decrease was more marked in the CR/PS group (p < 0.001). Neutrophil and lymphocyte counts increased in both AC/PS and CR/PS groups (p < 0.01). The extent of airway inflammation was also examined in the histological analysis of the lungs, which showed predominant perivascular and peribronchiolar inflammation, with centrilobular oedema and subpleural inflammation in the AC/PS group. In the CR/PS group, the changes were greater, with increased levels of IL-5, IL-17F, IL-13 and IL-10 and decreased levels of IL-2. CONCLUSIONS: Bronchial inflammation is present in acute and chronic models of HP following exposure to PS. Our results support the role of neutrophils and IL-17 in the development of the disease and an evolution towards a Th-2 immune response in chronic HP. These models may serve as a tool for future studies of the pathogenesis of HP.

Effect of anti-IgE in occupational asthma caused by exposure to low molecular weight agents.

BACKGROUND: The role of immunoglobulin (Ig)-E in occupational asthma (OA) due to low molecular weight (LMW) agents is not well established compared to classical atopic asthma. In this study, we evaluate whether anti-IgE monoclonal antibody (mAb) has an effect in a mouse model of OA, using persulfate salts. METHODS: On days 1 and 8, BALB/C mice were dermally sensitized with 5% ammonium persulfate (AP) or dimethyl sulfoxide (DMSO). On days 15, 18, and 21, animals were injected intraperitoneally with anti-IgE mAb or PBS 6 hours before challenge with AP or saline. Airway hyper-responsiveness (AHR) using a methacholine test, airway inflammation in bronchoalveolar lavage (BAL) and lung tissue, and total free IgE in serum samples were analyzed 24, 48, and 96 hours after the last challenge. RESULTS: Anti-IgE mAb treatment almost completely neutralized free serum IgE. In AP-sensitized and challenged mice, anti-IgE mAb treatment abolished AHR 24 hour and 48 hour after the last challenge and significantly reduced the total number of eosinophils and neutrophils 48 hour and 96 hour after the last AP challenge compared with nontreated mice. Levels of interleukin (IL)-13 in BAL were also significantly decreased after anti-IgE administration 24 hour and 48 hour after the last AP challenge. Histological analysis of the lung sections from anti-IgE-treated mice revealed normal inflammatory patterns similar to control groups 48 hour after the last challenge. CONCLUSIONS: Anti-IgE-treated mice showed a significant improvement in asthma features related to the AHR and airway inflammation. Anti-IgE mAb has positive effects in OA induced by persulfate salts.

Utility of Exhaled Nitric Oxide Fraction for the Diagnosis of Hypersensitivity Pneumonitis.

BACKGROUND: There is very little evidence of the utility of the exhaled fraction of NO (FeNO) for the diagnosis of interstitial lung disease and nearly all of it is related with connective tissue disease. Some authors have suggested that in patients with hypersensitivity pneumonitis (HP), evolution to pulmonary fibrosis may be mediated by a Th2 mechanism, which could redound in a potential utility of FeNO. The aim of this study was to investigate the values of FeNO before and after antigenic exposure with the specific inhalation challenge (SIC) and to analyze its potential utility for the diagnosis of HP. METHODS: It was a prospective, cross-sectional study of all patients older than 18 years referred to our center for suspected chronic HP between May 2012 and May 2014 and who underwent a SIC. FeNO was collected before and after SIC. RESULTS: The study sample comprised 25 patients. Eleven were diagnosed with chronic HP; six had been exposed to avian proteins and five to fungal agents. Of these 11 patients, seven had positive SICs. In the 14 patients with diagnoses other than HP, all the SICs were negative. No significant differences in baseline characteristics were observed according to HP diagnosis, except in the BAL lymphocyte count. No differences were found after the test in patients diagnosed with HP; nor were there differences in baseline FeNO in patients diagnosed with HP and those who received alternative diagnoses. CONCLUSIONS: The results suggest that FeNO measurement is not useful for the diagnosis of chronic HP.

Changes in PH in exhaled breath condensate after specific bronchial challenge test in patients with chronic hypersensitivity pneumonitis: a prospective study.

BACKGROUND: The aim of this study was to investigate the influence of the specific inhalation challenge (SIC) on changes of pH values in exhaled breath condensate (EBC) in patients with hypersensitivity pneumonitis (HP). METHODS: A prospective study of 85 patients with suspected HP, of whom 63 were diagnosed with HP due to exposure to avian or fungal antigens. In all cases, EBC samples were collected before and after completion of the SIC and pH values were determined. RESULTS: Taken as a whole, patients with HP did not present changes in EBC pH after SIC. However, considering only patients with exposure to molds, those diagnosed with HP had a significantly more acid pH post-SIC than those with another diagnosis (p = 0.011). This fact is not observed in patients exposed to bird's antigens. A ROC curve showed that a reduction in EBC pH of 0.3 units or more after SIC in patients diagnosed with HP due to exposure to molds had a sensitivity of 30 % (CI: 12.8 to 54.3 %) and a specificity of 100 % (CI: 65.5 to 100 %). CONCLUSION: EBC pH may be useful in interpreting SIC results in patients with HP, especially in those patients exposed to molds. Further studies are now required to test the validity of these proposals.

Progression of liver fibrosis in HIV/hepatitis C virus-coinfected individuals on antiretroviral therapy with early stages of liver fibrosis at baseline.

OBJECTIVES: The aim of the study was to assess the progression of liver fibrosis in HIV/hepatitis C virus (HCV)-coinfected patients with no or mild-to-moderate fibrosis (stages F0-F2). METHODS: Liver fibrosis was reassessed by transient elastometry (TE) between January 2009 and November 2011 in HIV/HCV-coinfected patients with stage F0-F2 fibrosis in a liver biopsy performed between January 1997 and December 2007. Patients with liver stiffness at the end of follow-up < 7.1 kPa were defined as nonprogressors, and those with values ≥ 9.5 kPa or who died from liver disease were defined as progressors. Cirrhosis was defined as a cut-off of 14.6 kPa. The follow-up period was the time between liver biopsy and TE. Cox regression models adjusted for age, gender and liver fibrosis stage at baseline were applied. RESULTS: The median follow-up time was 7.8 years [interquartile range (IQR) 5.5-10 years]. The study population comprised 162 patients [115 (71%) nonprogressors and 47 (29%) progressors; 19 patients (11.7%) had cirrhosis]. The median time from the diagnosis of HCV infection to the end of follow-up was 20 years (IQR 16.3-23.1 years). Three progressors died from liver disease (1.8%). The variables associated with a lower risk of progression were age ≤ 38 years (hazard ratio (HR) 0.32; 95% confidence interval (CI) 0.16-0.62; P = 0.001], having received interferon (HR 2.18; 95% CI 1.14-4.15; P = 0.017), being hepatitis B virus surface antigen (HBsAg) negative (HR 0.20; 95% CI 0.04-0.92; P = 0.039), and baseline F0-F1 (HR 0.43; 95% CI 0.28-0.86; P = 0.017). CONCLUSIONS: A high proportion of patients with stage F0-F2 fibrosis progress to advanced liver fibrosis. Advanced liver fibrosis must be included in the list of diseases associated with aging. Our results support the recommendation to offer HCV antiviral therapy to HIV/HCV-coinfected patients at early stages of liver fibrosis.

Hyaluronic acid, transforming growth factor-beta1 and hepatic fibrosis in patients with chronic hepatitis C virus and human immunodeficiency virus co-infection.

Chronic hepatitis C virus (HCV) infection follows an accelerated course in patients co-infected with human immunodeficiency virus (HIV); establishing the extent of liver fibrosis is crucial for disease staging and determining treatment strategy in these patients. The utility of noninvasive markers of fibrosis as alternatives to liver biopsy has not been well-studied in these patients. We evaluated the predictive value of serum transforming growth factor-beta1 (TGF-beta1) and hyaluronic acid (HA) levels for determining the extent of liver fibrosis. Liver biopsies and blood samples were collected from 69 consecutive patients (74% male; median age, 41 years) between May 2005 and November 2006. Serum TGF-beta1 and HA were analysed using commercial kits. Aspartate aminotransferase, alanine aminotransferase and gamma-glutamyl transpeptidase levels were elevated in 81%, 70% and 60% of patients, respectively. Fifty-three patients (90%) were on highly active antiretroviral therapy and the median CD4-positive cell count was 422 cells/microL. The extent of fibrosis according to Scheuer's scoring was 32% F0 (no fibrosis), 16.5% F1, 16.5% F2, 26% F3 and 7% F4 (cirrhosis). Mean serum TGF-beta1 was 36.1 +/- 14.4 ng/mL; mean serum HA was 75.2 +/- 85.0 microg/L. Serum HA was positively associated and significantly correlated with the stage of fibrosis (r = 0.56; P < 0.05). The area under the curve for discriminating mild (F0-F2) from significant (F3-F4) fibrosis in receiver operating analysis using HA was 0.83 (sensitivity, 87%; specificity, 70%). These data suggest that HA is clinically useful for predicting liver fibrosis and cirrhosis in patients co-infected with HCV/HIV. However, serum TGF-beta1 was not predictive of histological damage in co-infected individuals treated with HAART.

Reduced liver injury in the interleukin-6 knockout mice by chronic carbon tetrachloride administration.

BACKGROUND: Interleukin-6 has been involved in restoration of liver function after partial hepatectomy and toxic liver injury. However, normal liver regeneration in interleukin-6 knockout mice has also been reported. The aim of this work was to investigate the effect of interleukin-6 deficiency on liver injury and its regeneration in a model of long term carbon tetrachloride (CCl4) administration. DESIGN: Serum and whole livers from wild type and interleukin-6 knockout mice treated with carbon tetrachloride (0.25 mL kg(-1)) twice a week were obtained after 4, 6 and 8 weeks (n = 4-6). Sections were assessed for liver regeneration, liver injury and hepatocyte apoptosis whereas sera were assayed for aminotransferase levels. Nuclear extracts and total liver lysates were assayed for transcription factor activation and apoptosis related proteins, respectively. RESULTS: When compared to wild type, interleukin-6 knockout mice showed reduced liver damage scores, lower aminotransferase levels and diminished apoptosis, as well as reduced nuclear factor kappa B activation. Although the level of active protein was lower, activation of signal transducer and activator of transcription 3 still takes place in knockout mice. Furthermore, liver regeneration measured by bromodeoxyuridine incorporation showed no differences between wild type and knockout animals after 6 and 8 weeks of treatment. CONCLUSIONS: Compared to the wild type mice liver regeneration after chronic treatment with carbon tetrachloride proceeds at a slower rate in interleukin-6 deficient mice. However, this low recovery rate is accompanied by a reduction not only in hepatocyte apoptosis, but also in activation of nuclear factor kappa B and liver injury.

Protease inhibitor-containing regimens compared with nucleoside analogues alone in the suppression of persistent HIV-1 replication in lymphoid tissue.

OBJECTIVE: Lymphoid tissue provides a reservoir where HIV can persist. However, therapies incorporating a protease inhibitor can target this reservoir. This study was designed to investigate the relative long-term effects on lymph-node viral load and cellular architecture of regimens containing multiple nucleosides alone or in combination with protease inhibitors. METHODS: Axillary lymph-node biopsies from 12 patients with undetectable viraemia (viral load < 20 copies/ml: mean CD4 cells 525 x 10(6)/l) for a mean period of 25 months (range, 10-52 months) were investigated for the presence of HIV by in situ hybridization and coculture. Four patients were receiving multiple nucleoside analogues alone or in one case with a suboptimally dosed protease inhibitor (group I). Protease inhibitor was added to the regimen of seven patients at least 6 months prior to lymph-node biopsy (group II). Standard flow cytometry and virological data were obtained from peripheral blood every 3 months. RESULTS: By in situ hybridization, more productively infected CD4+ T cells were found in the lymph nodes of group I patients treated with nucleoside analogues alone. Very low numbers of productively infected lymph node cells were detected in the protease inhibitor-treated group II. No trapping of virions on the follicular dendritic cell (FDC) network was detectable in protease inhibitor-treated patients. In contrast, large deposits of FDC-bound virions were observed in three out of five patients from group I. Virus cultures from lymph node cells were positive in these three group I patients compared with only one out of seven patients from group II. Sequencing reverse transcriptase and protease genes from these isolates revealed typical mutations conferring resistance to the previously administered nucleoside analogue. A more preserved lymph node architecture and less signs of immunopathological change were also observed in protease inhibitor-treated patients. CONCLUSIONS: Undetectable plasma viraemia using the ultrasensitive PCR assay for prolonged periods of time does not always reflect complete HIV-1 suppression within the lymphoid compartment. Our results suggest that protease inhibitor-containing regimens target HIV reservoirs in lymphoid tissue more effectively and preserve or restore lymph node architecture.

Gastrointestinal autonomic nerve tumor: further observations regarding an ultrastructural and immunohistochemical analysis of six cases.

Gastrointestinal autonomic nerve tumor (GANT) is a specialized form of stromal neoplasm whose ultrastructural features support a myenteric plexus derivation and provide the basis for its diagnosis. GANT actual frequency, relationship to skeinoid fibers, and CD34 expression status are some of the controversial aspects of this entity. Out of 14 gastrointestinal stromal tumors gathered during a 1-year period, six (42%) instances were diagnosed as GANT by electron microscopic study of at least five ultrathin sections per case. Additionally, GANTs were immunohistochemically investigated with a panel of nine antibodies including CD34. Ultrastructurally, every GANT case showed diagnostic findings and evidence of skeinoid fibers, whereas immunohistochemically all except one were CD34 positive. Immunoreactivity for neuron-specific enolase, synaptophysin, and vimentin was a common occurrence as well. In conclusion, GANT seems to be more frequent than hitherto recognized, skenoid fibers are a regular feature of GANT, and a positive CD34 immunoreaction does not discriminate between GANT and other non-smooth muscle, non-schwannian neoplasms.

Proliferating cell nuclear antigen expression in normal, regenerative, and neoplastic liver: a fine-needle aspiration cytology and biopsy study.

Information about a tissue's proliferative activity can be obtained from the immunocytochemical investigation of proliferating cell nuclear antigen (PCNA), an auxiliary protein of DNA polymerase delta expressed by cycling cells. To determine whether a relationship exists between morphology and PCNA expression in normal, regenerative, and malignant neoplastic hepatocytes, this study was undertaken on 48 fine-needle aspiration cytology (FNAC) cell blocks from eight normal livers, eight cirrhotic livers, and 32 hepatocellular carcinomas (HCCs), as well as on 41 needle or wedge biopsy specimens from 10 normal livers, 13 cirrhotic livers, one focal nodular hyperplastic liver, and 17 HCCs. Anti-PCNA monoclonal antibody PC10 was applied to formalin-fixed, paraffin-embedded tissue using the avidin-biotin method. Proliferating cell nuclear antigen immunoreactivity was evaluated as follows: absent; minimal, less than 5% positive nuclei; grade 1, 5% to 25% positive nuclei; grade 2, 26% to 50% positive nuclei; grade 3, 51% to 75% positive nuclei; and grade 4, 76% to 100% positive nuclei. In both the FNAC and biopsy series normal and regenerative livers were either completely negative or minimally immunoreactive (under 5% positive nuclei). In contrast, all well-differentiated HCC cases exhibited over 15% positive nuclei. Most well-differentiated HCCs were grade 1 (85.7% in the FNAC series and 76.92% in the biopsy series) and the majority of moderately differentiated HCCs were grade 3 (63.63% in the FNAC series, but only 50% in the biopsy series). Therefore, absent or minimal PCNA immunoreactivity seems to be a useful adjuvant to discriminate normal/regenerative liver from HCC, whose degree of differentiation tends to correlate with the level of PCNA expression. These observations apply to both the FNAC and biopsy series, which yielded very similar data.

Expression of CD44H and CD44v3 in normal oesophagus, Barrett mucosa and oesophageal carcinoma.

AIMS: To examine CD44H and CD44v3 expression in normal gastric and small bowel mucosa, normal and Barrett oesophagus, and oesophageal epithelial malignancies (squamous cell carcinoma and adenocarcinoma). METHODS: Ninety five specimens, comprised of 40 of normal oesophageal, gastric and small bowel mucosa, 22 of Barrett oesophagus (two with dysplastic changes), 20 of resected adenocarcinomas, and 13 of squamous cell carcinoma, were evaluated. The samples were fixed in formalin and subsequently stained with anti-CD44H and anti-CD44v3 monoclonal antibodies using the avidin-biotin peroxidase technique. RESULTS: In contrast to normal oesophagus, which showed positivity for both CD44 epitopes (CD44H and CD44v3) in the basal third of the epithelium, antral and intestinal subtypes of Barrett oesophagus expressed CD44H only, the distribution being focal in non-dysplastic and diffuse in dysplastic Barrett mucosa. Similarly, normal antral glands and small bowel epithelium were focally immunopositive for CD44H at the base of the crypts. All squamous cell carcinomas were diffusely positive for both isoforms, whereas 75% (15/20) of the adenocarcinomas expressed CD44H and 60% (12/20) expressed CD44v3. CONCLUSIONS: CD44H is expressed in the proliferating areas of both normal squamous epithelium and Barrett mucosa. CD44H expression seems to increase progressively in dysplasia and infiltrating carcinoma, similar to the process described in the stomach. CD44v3 expression, usually not observed in normal or neoplastic gastric mucosa, was present in normal squamous epithelium and oesophageal squamous cell carcinoma. CD44v3 immunoreactivity was also identified in 60% of adenocarcinomas. These findings suggest that CD44v3 may play a role in the development of oesophageal carcinoma of both squamous and glandular types.

Differential expression of CD44v6 in metastases of intestinal and diffuse types of gastric carcinoma.

AIMS: To assess whether standard and variant isoforms of CD44 (CD44s, CD44v5, and CD44v6) have a differential expression profile in early versus advanced gastric adenocarcinoma of the diffuse and intestinal types and their metastases. METHODS: Immunohistochemical expression of CD44s, CD44v5, and CD44v6 was evaluated in 14 early gastric cancers (nine intestinal and five diffuse) and 37 advanced adenocarcinomas (21 intestinal and 16 diffuse) as well as in 18 cases of perigastric lymph node metastasis. Ten normal and five metaplastic gastric mucosa samples were also included in the study. RESULTS: Although no significant association was found between the degree of invasion and the CD44 expression profile, CD44v6 positivity was detected more frequently in metastases of intestinal-type carcinomas (66%) than in metastases of diffuse-type neoplasms (11%) (p < 0.05). Weak CD44s, CD44v5, and CD44v6 expression was observed focally in both normal and metaplastic gastric mucosa samples. CONCLUSIONS: These data suggest that CD44v6 expression may be involved in the production of lymph node metastases in intestinal-type gastric carcinoma but not in the diffuse-type disease, the metastatic potential of which is most likely unrelated to the CD44 family of adhesion molecules.

Differential expression of CD44v6 in adenocarcinoma of the pancreas: an immunohistochemical study.

Alternative splicing gives rise to numerous CD44 isoforms, some of which seem to have a role in tumour metastasis. Specifically, a variant form of CD44 with sequences encoded by exon v6 (CD44v6) confers metastatic potential when transfected into a nonmetastasizing cell line of rat pancreatic adenocarcinoma. This study has investigated standard CD44 (CD44s) and CD44v6 expression immunohistochemically in 6 samples of normal pancreatic tissue, 4 of tissue affected by chronic pancreatitis, and 24 of tissue from metastasizing and nonmetastasizing pancreatic adenocarcinomas. In addition, 18 samples from lymph node or visceral metastases were included in the study. CD44s was expressed in nonneoplastic tissue and in tissue from pancreatic adenocarcinomas. In contrast, CD44v6 was not detected in any of the normal tissue or chronic pancreatitis specimens, whereas 54% of pancreatic adenocarcinomas and 55% of metastases expressed this variant exon. Although it is not clear whether CD44 isoforms containing exon v6 play a part in malignant progression in the human exocrine pancreas, it seems plausible that the expression of multiple isoforms containing this and other variant exon confers a selective advantage on pancreatic adenocarcinoma.

Effect of L-arginine on the course of experimental colitis.

BACKGROUND AND AIMS: L-Arg is the substrate for nitric oxide, and also for L-ornithine which, in turn, is the precursor for the synthesis of collagen and polyamines. By these different metabolic pathways, L-Arg is involved in the mechanisms of inflammation, tissue repair and fibrosis. Thus, the aim of this study was to assess the effect of both different amounts of L-Arg supplementation and L-Arg-free diets upon colonic inflammatory damage and fibrosis in experimental colitis. METHODS: Sprague-Dawley rats with trinitrobenzene sulphonic acid (TNBS)-induced colitis received increasing doses of L-Arg (30, 100, 500 mg/day), or D-Arg (500 mg/day). In a second experiment, two L-Arg-free diets (one supplemented with L-Gly) were compared to a L-Arg diet. Nitrite/nitrate release in the lumen of the colon and colonic damage were evaluated. In the first experiment, tissue collagen levels and colonic mucosal proliferation were also assessed. RESULTS: In the acute phase of colitis, intracolonic nitrite/nitrate levels were significantly higher in the 100 and 500 mg supplemented L-Arg groups than in D-Arg group. However, only rats treated with 500 mg of L-Arg showed moderately higher inflammatory and fibrosis colonic scores than the D-Arg treated rats. There was no significant influence of L-Arg-free diets on the course of TNBS-induced colitis. However, L-Arg diet accelerated weight gain both pre- and post-TNBS. CONCLUSIONS: These results suggest that normal amounts of L-Arg in the diet are not harmful, whereas both absence of L-Arg or supplementation with high doses of this amino acid may be deleterious. In the former this might be due to a decrease of nitrogen retention in injured rats, whereas in the latter it may result from both nitric oxide-mediated tissue damage and collagen deposition.

p53 immunoreaction in hepatocellular carcinoma and its relationship to etiologic factors. A fine needle aspiration study.

OBJECTIVE: To determine immunohistochemically the expression of mutant p53 phosphoprotein in hepatocellular carcinoma (HCC) and its possible relationship to several etiologic factors. STUDY DESIGN: The study group consisted of 62 samples of HCC, grades 2, 3 and 4, obtained by fine needle aspiration cytology. The associated risk factors detected in these patients were as follows: ethanol abuse, ethanol abuse plus hepatitis B virus (HBV) or hepatitis C virus (HCV) infection, HBV infection, HCV infection, non-A/ non-B hepatitis, hemochromatosis and obesity. RESULTS: Mutant p53 expression was identified in 22% of HCC and seemed to correlate with tumor grade. Positive immunostaining was frequently associated with a history of alcohol abuse (42%) and also with viral infection (HBV, 21%; HCV, 7%; non-A/non-B hepatitis, 7%). CONCLUSION: Mutant p53 seems to intervene in the progress of HCC through various grades of increasing malignancy. The association we found between alcohol intake and mutant p53 expression may deserve further investigation.

[Cardiac tamponade and Kaposi's sarcoma]. / Taponamiento cardíaco y sarcoma de Kaposi.

The case of a 31 year-old intravenous drug addict female patient with infection by the human immunodeficiency virus who had recurrent cardiac tamponade and who was diagnosed by pericardic biopsy as Kaposi's sarcoma is reported. The patient demonstrated involvement by cutaneous, mucosal, lymph node and probably pleuropulmonary Kaposi's sarcoma. Thoracic radiography, computerized tomography and echocardiography only showed the presence of pericardic effusion. Neither did the pericardic fluid obtained by pericardiocentesis provide any significant ethiologic data. Only the pericardic biopsy showed the typical lesions of Kaposi's sarcoma in this localization confirming diagnosis. This is the first case of pericardic Kaposi's sarcoma described in an alive patient and the difficulties of achieving the diagnosis of the cardiac involvement by Kaposi's sarcoma in AIDS patients are commented upon.