Idiopathic myointimal hyperplasia of mesenteric veins and pneumatosis intestinalis: a previously unreported association

Idiopathic myointimal hyperplasia of mesenteric veins is a very rare disease occurring in young male patients, with no more than eight cases reported in the world literature. It causes venous ischemia in the sigmoid colon and rectum that clinically resembles inflammatory bowel disease. Pneumatosis intestinalis is also a rare condition usually associated to a wide range of diseases including bowel ischemia. We herein report on a case of pneumatosis intestinalis associated to idiopathic myointimal hyperplasia of mesenteric veins. To our knowledge, this is the first report of such an association, and the first one of idiopathic myointimal hyperplasia of mesenteric veins occurring in a female patient as well.

Lactobacillus fermentum CECT 5716 prevents and reverts intestinal damage on TNBS-induced colitis in mice

BACKGROUND

Probiotics attenuate gut inflammation when administered before experimental colitis, but data on their effect after colitis induction are scarce. We aimed to evaluate the effects of Lactobacillus fermentum CECT 5716 on gut injury when administered either before or after trinitrobencene sulfonic acid (TNBS) colitis in Balb/c mice.

METHODS

In a preventive study, probiotic or vehicle was administered for 2 weeks before colitis. Then mice were allocated to: probiotic + TNBS, probiotic + sham, vehicle + TNBS, or vehicle + sham, and sacrificed 72 hours later. In a therapeutic study, mice were allocated into the same groups as before. Probiotic or vehicle were administered for 3 weeks. Mice were sacrificed at weeks 1, 2, and 3 after TNBS. Histological score, myeloperoxidase activity, and eicosanoid and cytokine production in colonic explant cultures were measured. Immunohistochemistry for nitrotyrosine and MyD88 was also performed.

RESULTS

In the preventive study, colitis was milder with probiotic than with vehicle (P = 0.041). This was associated with increased PGE(2), IL-2, and IL-4 production, as well as attenuated nitrotyrosine staining in the former. In the therapeutic study, histological score at week 1 post-TNBS was higher in probiotic than in vehicle fed mice (P = 0.018). However, at weeks 2 and 3 the histological score was significantly lower-with decreased IL-6 production and increased MyD88 staining-in mice receiving the probiotic.

CONCLUSIONS

Pretreatment with L. fermentum CECT 5716 attenuates TNBS colitis, an effect that seems to be due to its antioxidant abilities. When administered after TNBS, this probiotic is also effective in accelerating colitis recovery, and this is associated with an enhanced Toll-like receptor function.

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.

Partial replacement of dietary (n-6) fatty acids with medium-chain triglycerides decreases the incidence of spontaneous colitis in interleukin-10-deficient mice

Enteral nutrition has a primary therapeutic effect in active Crohn's disease. It is unknown which nutrient(s) account for this action, but a role for both the amount and type of dietary fat has been postulated. Some clinical and experimental data suggest that medium-chain triglycerides (MCT) may reduce intestinal inflammation. We aimed to assess the effect of replacing part of the dietary fat with MCT on the incidence and severity of colitis in interleukin (IL)-10(-/-) mice under specific pathogen-free conditions. Twenty-four IL-10(-/-) 4-wk-old mice were randomized to receive a control diet based on sunflower oil [(n-6) fatty acids (FA)] and an experimental isocaloric, isonitrogenous diet with 50% sunflower and 50% coconut oil (MCT diet). When the mice were 12 wk old, they were killed and the colon was examined for the presence of colitis, lymphocyte subpopulations and apoptosis, ex vivo cytokine production in supernatant of colon explants, toll-like receptor (TLR)-2 and TLR-9 mRNA, and FA profile in colonic tissue homogenates. Colitis incidence was lower in the IL-10(-/-) mice fed the MCT diet (1/12) than in the mice fed the control diet (8/12; P = 0.03). The histological damage score was also lower in the former (P < 0.0005). Feeding the MCT diet resulted in fewer total and apoptotic intraepithelial CD3+ and lamina propria CD3+CD4+ lymphocytes, as well as downregulated production of IL-6 and interferon-gamma, and reduced TLR-9 mRNA. We conclude that partial replacement of dietary (n-6) FA with MCT decreases the incidence of colitis in a model of spontaneous intestinal inflammation and provide experimental arguments for a possible primary therapeutic effect of MCT in human Crohn's disease.

Accuracy of simple biochemical tests in identifying liver fibrosis in patients co-infected with human immunodeficiency virus and hepatitis C virus

BACKGROUND & AIMS

We assessed the ability of 3 simple biochemical tests to stage liver fibrosis in patients co-infected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV).

METHODS

We analyzed liver biopsy samples from 324 consecutive HIV/HCV-positive patients (72% men; mean age, 38 y; mean CD4+ T-cell counts, 548 cells/mm(3)). Scheuer fibrosis scores were as follows: 30% had F0, 22% had F1, 19% had F2, 23% had F3, and 6% had F4. Logistic regression analyses were used to predict the probability of significant (>or=F2) or advanced (>or=F3) fibrosis, based on numeric scores from the APRI, FORNS, or FIB-4 tests (alone and in combination). Area under the receiver operating characteristic curves were analyzed to assess diagnostic performance.

RESULTS

Area under the receiver operating characteristic curves analyses indicated that the 3 tests had similar abilities to identify F2 and F3; the ability of APRI, FORNS, and FIB-4 were as follows: F2 or greater: 0.72, 0.67, and 0.72, respectively; F3 or greater: 0.75, 0.73, and 0.78, respectively. The accuracy of each test in predicting which samples were F3 or greater was significantly higher than for F2 or greater (APRI, FORNS, and FIB-4: >or=F3: 75%, 76%, and 76%, respectively; >or=F2: 66%, 62%, and 68%, respectively). By using the lowest cut-off values for all 3 tests, F3 or greater was ruled out with sensitivity and negative predictive values of 79% to 94% and 87% to 91%, respectively, and 47% to 70% accuracy. Advanced liver fibrosis (>or=F3) was identified using the highest cut-off value, with specificity and positive predictive values of 90% to 96% and 63% to 73%, respectively, and 75% to 77% accuracy.

CONCLUSIONS

Simple biochemical tests accurately predicted liver fibrosis in more than half the HIV/HCV co-infected patients. The absence and presence of liver fibrosis are predicted fairly using the lowest and highest cut-off levels, respectively.

Cytomegalovirus infection in ulcerative colitis: a prospective, comparative study on prevalence and diagnostic strategy

BACKGROUND

Cytomegalovirus (CMV) infection has been reported in ulcerative colitis (UC), especially in severe, steroid-refractory disease. However, its role in steroid-refractoriness remains unknown. Our goals were to evaluate the prevalence of CMV disease in UC, the best diagnostic strategy, and the influence of disease activity and/or treatment in its development.

METHODS

Prospective, observational study including 114 subjects with active UC requiring intravenous steroids, steroid-refractory UC, inactive UC on mesalamine, inactive UC on azathioprine, and healthy controls. CMV antibodies, pp65-antigenemia, and rectal biopsies for hematoxylin and eosin staining, immunohistochemistry, and CMV-pp67 mRNA were performed. These procedures were repeated after medical treatment only in patients with active UC. CMV disease was defined by the presence of inclusion bodies and/or positive immunohistochemistry in colonic biopsies.

RESULTS

CMV disease was found in 6 steroid-refractory, CMV-IgG-positive UC patients but not among controls, inactive UC, or steroid-responding UC patients. In 5 out of the 6 patients, CMV disease was diagnosed after 7-10 days on cyclosporine.

CONCLUSIONS

CMV disease in UC only affects seropositive, steroid-refractory UC patients. Steroid/cyclosporine treatment together with disease activity may predispose to latent colonic CMV reactivation. The impact of antiviral therapy on the clinical outcome of these patients remains to be elucidated.

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.

Plasma ghrelin concentrations in type 1 diabetic patients with autoimmune atrophic gastritis

OBJECTIVE

Type 1 diabetes mellitus patients (DM1) show increased prevalence of pernicious anaemia, the histological substrate of which is type A chronic atrophic gastritis (CAG) in the stomach corpus, the main source of ghrelin. We aimed to compare plasma ghrelin concentrations in DM1 patients with type A CAG (DM1-CAG), DM1 patients without type A CAG and healthy controls and in DM1-CAG group, to ascertain a possible relationship between ghrelin and biochemical markers of gastric mucosa atrophy and/or neuroendocrine (NE) cell hyperplasia and histological gastric biopsy findings.

DESIGN AND METHODS

Fifteen DM1-CAG patients were matched for age, sex and body mass index with 15 DM1 patients without type A CAG and 15 controls. Pepsinogen I, pepsinogen II, gastrin, parietal cell antibodies, chromogranin A (CgA) and ghrelin were determined in all subjects. In DM1-CAG patients, immunohistochemical analysis of gastric biopsies using antibodies to CgA and ghrelin was performed.

RESULTS

Ghrelin concentrations differed among groups; however, paired comparisons between groups were not significant. In DM1-CAG, no correlation was found between ghrelin and gastric body atrophy markers, pepsinogen I and the pepsinogen I/II ratio. Immunohistochemical studies of DMI-CAG patients showed CgA staining in 12 and ghrelin staining in 6, which was confined to the foci of NE cell hyperplasia. Those patients who stained positive for ghrelin had higher ghrelin concentrations when compared with the negative patients.

CONCLUSIONS

Ghrelin concentrations are not decreased in DM1-CAG patients; thus, our data suggest that ghrelin is not a good marker of gastric mucosa atrophy in these patients, given the possible ghrelin synthesis in hyperplastic gastric endocrine/enterochromaffin-like cells.

Suspected cross-hepatotoxicity of flutamide and cyproterone acetate

Flutamide and cyproterone acetate (CPA) are both oral anti-androgens commonly used to treat advanced prostatic cancer. We report a case of drug-induced hepatotoxicity after consecutive treatment with flutamide and CPA. A 78-year-old male with advanced prostatic adenocarcinoma had been treated with flutamide 750 mg/day p.o. and leuproleride acetate 22.5 mg/3 months i.m. Three months later, the patient complained of choluria and jaundice. Laboratory examination revealed severe hepatocellular insufficiency. Flutamide-induced hepatotoxicity was suspected and therefore flutamide was withdrawn. His liver function abnormalities resolved after drug discontinuation. He was subsequently started on CPA 150 mg/day and again developed hepatotoxicity with severe hepatocellular impairment, which completely recovered after drug discontinuation. Other causes of acute liver failure were appropriately ruled out in both episodes and there was no evidence of active prostate cancer or liver metastases in both episodes. The occurrence of hepatotoxicity associated with flutamide and CPA on separated occasions suggests the possibility of a common mechanism of injury. It may become necessary to reassess the common practice of switching to another anti-androgen when hepatotoxicity appears. A closer monitoring of liver enzymes might be necessary in such cases, as an increased risk of a new severe hepatotoxicity event cannot be ruled out.

Collagenous duodeno-ileo-colitis with transient IgG deficiency preceded by Yersinia enterocolitica intestinal infection: case report and review of literature

A case-report of a man with chronic diarrhoea is presented. After an unsuccessful treatment of an intestinal yersioniosis, the diagnosis of collagenous intestinal disease affecting duodenum, ileum and colon was made. In addition, a IgG transient deficiency was observed. The literature about gastrointestinal involvement, concomintant infection by Yersinia and IgG deficiency in collagenous colitis is reviewed.

[Acute appendicitis in inactive extensive ulcerative colitis]

Appendectomy is associated with a reduced risk of developing ulcerative colitis (UC). In addition, there may be appendicular involvement in UC in patients with extensive or even left-sided disease. However, no data are available on the incidence, clinical presentation and outcome of acute appendicitis in patients previously diagnosed with UC. The impact of appendectomy in this subset of patients also remains to be determined. We describe 2 cases of acute appendicitis in the setting of inactive extensive ulcerative colitis and compare their histologic features with those of the surgical specimens of 2 further UC patients colectomized for refractory and extensive disease.

Endoscopic removal of large sessile colorectal adenomas: is it safe and effective?

Large sessile colorectal polyps represent a treatment challenge. Nowadays there are discrepancies regarding how to proceed with them because of morbidity, the possibility of incomplete endoscopic resection, and the high possibility of a coexisting malignancy. This study was performed to determine the safety and effectiveness of endoscopic removal of sessile colorectal adenomas larger than 4 cm. Seventy-four patients with a total of 74 sessile polyps larger than 4 cm in diameter were treated endoscopically. Polyps were removed using argon plasma coagulation (APC) as an adjunct to piecemeal technique. Surgery was recommended in patients with invasive neoplasia. Patients with favorable histology (low-grade dysplasia [LDG] or high-grade dysplasia [HGD]) were followed up with monthly endoscopies untill total ablation of the lesion, and then at 3- to 6-month intervals. LGD was found in 38 patients, HGD in 24, and invasive neoplasia in the remaining 12 patients. A total of 54 patients were followed up for at least 6 months. Recurrence rate of polyps with favorable histology was 9.2% (5/54). Postpolypectomy bleeding was the only complication, observed in 10 patients (13.5%). We conclude that piecemeal polypectomy plus APC without saline injection, performed by an expert endoscopist, is a safe and effective treatment for all LGD or HGD large sessile colorectal polyps.

Insulin-like growth factor I improves intestinal barrier function in cirrhotic rats

BACKGROUND AND AIMS

In liver cirrhosis, disruption of the intestinal barrier facilitates bacterial translocation and spontaneous bacterial peritonitis. Insulin-like growth factor I (IGF-I) is an anabolic hormone synthesised by hepatocytes that displays hepatoprotective activities and trophic effects on the intestine. The aim of this study was to investigate the effect of IGF-I on intestinal barrier function in cirrhotic rats.

METHODS

In rats with carbon tetrachloride induced cirrhosis, we investigated the effect of IGF-I therapy on: (a) portal pressure; (b) intestinal histology and permeability to endotoxin and bacteria; (c) intestinal expression of cyclooxygenase 2 (COX-2) and tumour necrosis factor alpha (TNF-alpha), two factors that influence in a positive and negative manner, respectively, the integrity of the intestinal barrier; (d) intestinal permeability to 3H-mannitol in rats with bile duct ligation (BDL); and (e) transepithelial electrical resistance (TER) of polarised monolayers of rat small intestine epithelial cells.

RESULTS

IGF-I therapy reduced liver collagen expression and portal pressure in cirrhotic rats, induced improvement in intestinal histology, and caused a reduction in bacterial translocation and endotoxaemia. These changes were associated with diminished TNF-alpha expression and elevated COX-2 levels in the intestine. IGF-I reduced intestinal permeability in BDL rats and enhanced barrier function of the monolayers of epithelial intestinal cells where lipopolysaccharide (LPS) caused a decrease in TER that was reversed by IGF-I. This effect of IGF-I was associated with upregulation of COX-2 in LPS treated enterocytes.

CONCLUSIONS

IGF-I enhances intestinal barrier function and reduces endotoxaemia and bacterial translocation in cirrhotic rats. IGF-I therapy might be useful in the prevention of spontaneous bacterial peritonitis in liver cirrhosis.

Antimalarial myopathy: an underdiagnosed complication? Prospective longitudinal study of 119 patients

OBJECTIVES

To evaluate the prevalence and incidence of antimalarial myopathy in patients with rheumatic diseases treated with antimalarial drugs.

METHODS

Over a three year period, all patients with rheumatic diseases who were taking antimalarial drugs were studied. Serum muscle enzymes were assessed at the time of inclusion and every six months thereafter. Muscle strength, electromyography (EMG), and muscle biopsy were assessed in patients with a persistent muscle enzyme disturbances.

RESULTS

119 patients were included (111 chloroquine, eight hydroxychloroquine). Of these, 22 (18.5%) had a persistent muscle enzyme disturbance: lactate dehydrogenase 19/22 (86%); creatine kinase 7/22 (32%), and aldolase 3/22 (14%). Findings of antimalarial myopathy were detected in 3/15 biopsied patients (20%) by light microscopy and in all 15 by electron microscopy. Eleven patients had myopathy at the time of inclusion (prevalence 9.2%) and four patients developed muscle injury during follow up (annual incidence 1.2%). Muscle weakness was observed in 8 of 15 patients with biopsy proven myopathy, giving a prevalence of clinical antimalarial myopathy of 6.7%. All these patients also had a myopathic pattern on electromyography.

CONCLUSIONS

The prevalence of antimalarial myopathy is higher than previously recognised when muscle enzyme determination is used as a screening method. When a persistent muscle enzyme disturbance is observed, clinical and electromyographic studies should be undertaken periodically to detect the development of clinical myopathy. In cases of clinical myopathy, an anatomical-pathological tissue study, including an ultrastructural study, is mandatory to confirm the diagnosis.

Advanced liver fibrosis in HIV/HCV-coinfected patients on antiretroviral therapy

HIV infection is believed to adversely affect the progression of hepatitis C virus (HCV)-related liver disease. However, information regarding HIV and HCV coinfection in the era of highly active antiretroviral therapy (HAART) is scarce. A cross-sectional study in 75 HCV/HIV-coinfected patients (most of them on HAART) and 75 HCV-monoinfected patients paired by age, sex, and date of liver biopsy analyzed the association of HIV infection with advanced liver fibrosis (Knodell fibrosis stages 3 + 4). The median CD4 cell count in HIV-coinfected patients was 546 cells/microl; 78.7% had an HIV-1 viral load <1000 copies/ml and 88% were on antiretroviral therapy. The percentage of patients harboring genotype 4 and with a higher HCV viral load was greater in the HIV-coinfected group. HCV/HIV-coinfected patients had more advanced liver fibrosis (Knodell fibrosis stages 3 + 4) than HCV-monoinfected patients (46.7% vs. 12%, p < 0.0001). In the univariate analysis, the factors associated with advanced liver disease were male sex (OR: 2.7, 95% CI: 1.05-7.1), history of injecting drug use (OR: 4.6, 95% CI: 2.0-10.2), HIV infection (OR: 6.4, 95% CI: 2.7-14.7), and previous exposure to therapy with protease inhibitors (OR: 3.0, 95% CI:1.4-6.3). In the multivariate analysis; only male sex (OR: 3.17, 95% CI: 1.152-8.773) and HIV infection (OR: 6.85, 95% CI: 2.93-16.005) were associated with advanced liver fibrosis. HIV infection is associated with advanced liver fibrosis. HIV/HCV-coinfected individuals on HAART are at risk of developing end-stage liver disease despite virological success and immunological reconstitution.

[Intestinal myopathy in Steinert's disease]

The myothonic dystrophy or Steinert's disease is a congenital, autosomal, dominant disorder which seriously affects the striated muscle and also to a certain extent, several organs and systems and on rare occasions, the intestinal smooth muscle. In the case, we treated a four years old girl in whom Steinert's disease was diagnosed when she was born and who developed the characteristics of severe constipation after a few months of life. The ano-rectal manometry showed a paradoxical reaction of external Sphincter with a normal inhibitory reflex. The rectal biopsy revelated a miophathy which affected the muscularis propia with the normal neuronal innervation. The X-ray studies showed that motility disorder was stopped in the distal area of the left colon. A colostomy in the healthy zone worked extremely well. Six months later, the normal colon was brought down retro-rectal. Only a partial incontinence remained in the external sphincter caused by Steinert's disease. The interest of this case lies in the pathological association, striade muscle and smooth muscle, in such an early age of life. It is a new contribution to the complex chapter of the intestinal pseudo-obstruction.

[Presinusoidal portal hypertension due to portal thrombosis in a patient with Alagille's syndrome]

We present the case of a 16-year old woman with Alagille's syndrome, who had upper gastrointestinal bleeding due to rupture of esophageal varices secondary to presinusoidal portal hypertension without liver fibrosis. Portal thrombosis is a manifestation previously unreported in association to this syndrome.

[Chloroquine-induced myopathy and neuropathy: progressive tetraparesis with areflexia that simulates a polyradiculoneuropathy. Two case reports]

INTRODUCTION

Chloroquine is a drug that is widely used in rheumatology and occasionally prescribed in dermatology. From a neurotoxicological point of view, chloroquine can have effects on the peripheral nerves, muscles, neuromuscular junctions and the central nervous system. In this study we analyse the clinical, neurophysiological and anatomopathological findings in two patients with chloroquine induced neuromyopathy, which took the form of a polyradiculoneuropathy.

CASE REPORTS

Case 1: a 75 year old female with rheumatoid arthritis treated with daily doses of 250 mg of chloroquine for four years. The patient visited because of several months history of predominantly proximal progressive tetraparesis with areflexia. Analytical tests and lumbar puncture were normal. Electromyogram (EMG): proximal myopathic and distal neuropathic patterns. Muscular biopsy: vacuolar myopathy with accumulations of phagolysosomes, lipids, lipofuscin, myelinic curvilinear bodies. Case 2: a 74 year old female with arthropathy treated with daily doses of 250 mg of chloroquine for nine months. The patient presented a progressive proximal paraparesis with generalised areflexia. Analytical tests and lumbar puncture were normal. EMG: mixed sensory motor polyneuropathy, myogenic pattern with high frequency discharges in the iliac psoas and a neurogenic pattern in the distal muscles. Muscular biopsy: vacuolar myopathy suggesting a myopathy due to chloroquine. After stopping treatment with this drug the patients progressed favourably.

CONCLUSION

Chloroquine can induce a clinical pattern that suggests a polyradiculoneuropathy. It is important to establish a history of having taken this drug. If this is indeed the case, then an electromyographic study of the most proximal muscles should be performed in order to detect a myogenic pattern and the same exploration should be applied to the distal muscles to reveal a neurogenic pattern. The final diagnosis will be established by muscular biopsy.

Time on antiretroviral therapy is a protective factor for liver fibrosis in HIV and hepatitis C virus (HCV) co-infected patients

To assess the factors associated with liver fibrosis in human immunodeficiency virus and hepatitis C virus (HIV/HCV) co-infected patients eligible for anti-HCV therapy, we performed an observational, single-centred, cross-sectional study of 180 HIV/HCV co-infected patients who underwent liver biopsy between May 1998 and November 2001. A total of 126 patients with a known date of HCV infection were evaluated. Liver fibrosis was defined as a Knodell stage of fibrosis 1-4. The mean age was 36.7 (3.8) years, 81% were male and had a mean age of 20.5 (3.8) years at HCV infection. Mean CD4 cell count and plasma HIV-1 RNA load at the time of biopsy were 552 cell/mm3 (239) and 2.5 log10 (0.9), respectively; 118 patients had been on antiretroviral therapy (ART) for a median of 45 months (Q1-Q3: 21-75) and 84 on protease inhibitor for a median of 12.0 months (Q1-Q3: 0-29.5); 55 had an AIDS event or a CD4 cell count nadir < 200 cells/mm3 prior to biopsy. Median histological activity index was 6 and 27% had a Knodell stage of fibrosis 0. On the multivariate analysis time on ART (OR for 6 months extra: 0.954, 95% CI: 0.859-0.994), CD4 cell count at the time of liver biopsy (OR for 100 cells/mL increase: 0.740, 95% CI: 0.670-0.905), age at HCV infection acquisition (OR for 5 years extra: 2.594, 95% CI: 1.326-5.133) and alcohol intake (> 50 g/day) (OR: 2.73, 95% CI: 1.108-6.731) were associated with liver fibrosis. Hence ART should be a priority in HIV/HCV co-infected patients eligible for anti-HCV treatment as it is a protective factor for liver fibrosis.

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.

Prognostic value of K-ras mutations and allelic imbalance on chromosome 18q in patients with resected colorectal cancer

PURPOSE

We designed this study to assess the frequency of K-ras mutations in patients with resected colorectal tumors and their association with survival. A second objective was to analyze the prognostic value of different K-ras genotypes. In a subgroup of patients we also investigated the presence of allelic imbalance on chromosome 18q and its relationship to clinical outcome.

METHODS

One hundred fourteen colorectal tumors resected between 1983 and 1986 were analyzed to detect K-ras point mutations at codons 12, 13, and 61 by polymerase chain reaction followed by allele specific oligonucleotide hybridization. A subgroup of 77 tumors was further screened to detect loss of heterozygosity on chromosome 18q using three polymorphic microsatellite markers (D18S67, D18S474 and D18S58).

RESULTS

K-ras mutations were detected in 29 percent (33/114) of patients. K-ras mutations correlated with age and preoperative carcinoembryonic antigen levels, and there was some indication that they may be linked to poor survival, especially in Stage II tumors, where a subgroup of patients with aspartic and serine mutations showed significantly reduced survival (P = 0.03) compared with K-ras-negative patients. 18q loss of heterozygosity was present in 39 percent (25/63) of tumors. A multivariate analysis of Stage II tumors showed that 18q loss of heterozygosity was significantly associated with a worse prognosis (P = 0.006). A significant decrease in survival was identified in ten patients harboring both genetic alterations (K-i mutations and 18q loss of heterozygosity; P = 0.02).

CONCLUSIONS

In colorectal tumors, K-ras mutations and 18q loss of heterozygosity are two genetic markers which may identify patients with more aggressive behavior, mainly in Stage II tumors. These findings warrant further research, because they can be useful in customizing adjuvant chemotherapy.

Evolution of granulomas in lungs of mice infected aerogenically with Mycobacterium tuberculosis

Aerogenous infection of C57Bl/6 mice with a virulent strain of Mycobacterium tuberculosis (CL 511) leads to the formation of primary granulomas in the lung where neutrophils, macrophages and subsequently, lymphocytes accumulate progressively around an initial cluster of infected macrophages. The spread of infection through the lung parenchyma gives rise to secondary granulomas featuring numerous lymphocytes that surround a small number of infected macrophages. Afterwards, foamy macrophages add an outer layer to the granulomas, which characteristically respect the pulmonary interstitium and remain confined within the alveolar spaces. This feature, in conjunction with the constant presence of M. tuberculosis in the products of broncho-alveolar lavage, suggests that the upward bronchial migration of infected macrophages may contribute significantly to pulmonary dissemination of mycobacterial infection. The latter would be in agreement with the persistence of chronic pulmonary infection in spite of a concomitant strong T helper 1 cell response.