PubMed Health⌕ Search

Biomedical subjects

M Margiotta

Publications and source records attributed to M Margiotta.

At least 19 recordsLinked to original sources
PubMed2006

Primary clarithromycin resistance in Italy assessed on Helicobacter pylori DNA sequences by TaqMan real-time polymerase chain reaction.

BACKGROUND: Helicobacter pylori clarithromycin resistance is increasing worldwide and different mutations are involved in its mechanisms. Recently, molecular methods have been proposed to assess these mutations. AIM: To assess prevalence of primary clarithromycin resistance in two Italian areas, and the distribution of involved mutations, by using a novel method for real-time polymerase chain reaction. METHODS: Two hundred and thirty-two H. pylori-positive patients undergoing oesophagogastroduodenoscopy in two Italian towns (Rome, centre Italy; Foggia, south Italy) were enrolled. Helicobacter pylori infection was detected by histology, rapid urease and urea breath tests. Clarithromycin resistance was assessed by TaqMan real-time polymerase chain reaction on paraffin-embedded antral biopsies. Results Primary clarithromycin resistance was detected in 62 (26.7%) patients. Its prevalence did not differ between the two areas (31.5%, centre vs. 23.3%, south; P=0.17) and between non-ulcer dyspepsia and peptic ulcer patients (28.4% vs. 20.7%, P=0.2). The A2143G point mutation was detected in 35 (56.4%) patients, A2142G in 14 (22.6%), A2142C in eight (12.9%), whilst a double mutation (A2143G plus A2142C or A2142G) was present in the remaining five (8.1%) cases. CONCLUSIONS: Our study found that primary clarithromycin resistance is highly prevalent in both central and southern Italy, and that A2143G is the most frequent point mutation involved in these areas.

Anti-Bacterial Agents↗
PubMed2005

DNA sequences and proteic antigens of H. pylori in cholecystic bile and tissue of patients with gallstones.

BACKGROUND: Although Helicobacter pylori DNA sequences have been detected in cholecystic bile and tissue of patients with gallstones, controversial results are reported from different geographic areas. AIM: To detect H. pylori in cholecystic bile and tissue of patients with gallstones from a previously uninvestigated geographic area, southern Italy. Detection included both the bacterial DNA and the specific antigen (H. pylori stool antigen) identified in the stools of infected patients for diagnostic purposes. PATIENTS AND METHODS: The study enclosed 33 consecutive patients undergoing laparoscopic cholecystectomy for gallstones. DNA sequences of H. pylori were detected by polymerase chain reaction in both cholecystic bile and tissue homogenate. Moreover, we assayed H.pylori stool antigen on gall-bladder cytosolic and biliary proteins after their extraction. Bacterial presence in the stomach was assessed by urea breath test in all patients and Deltadelta13CPDB value assumed as marker of intragastric load. Fisher's exact probability and Student's t-tests were used for statistical analysis. RESULTS: DNA sequences of H. pylori in bile were found in 51.5% and significantly correlated with its presence in cholecystic tissue homogenate (P<0.005), H. pylori stool antigen in gall-bladder (P=0.0013) and bile (P=0.04) proteins, gastric infection (P<0.01) and intragastric bacterial load (P<0.001). No correlation was found, however, with sex and age of the patients. CONCLUSIONS: Our prevalence value of bacterial DNA in bile and gall-bladder of patients with gallstones agreed with that of the only other Italian study. The simultaneous presence of both bacterial DNA and proteic antigen suggests that the same prototype of bacterium could be located at both intestinal and cholecystic level and, therefore, the intestine represents the source of biliary contagion.

Aged↗
PubMed2005

Epithelial cell proliferation of the colonic mucosa in diverticular disease: a case-control study.

BACKGROUND: A higher risk of both advanced adenoma and carcinoma occurs in the sigmoid colon of patients with diverticular disease, for which bacterial carcinogens have been claimed to play a role. AIM: To assess epithelial cell proliferation in colonic mucosa of diverticular disease patients before and after rifaximin treatment. METHODS: Twelve consecutive patients with a new endoscopic diagnosis of left-sided diverticular disease and 12 matched controls were enrolled. Epithelial cell proliferation in the sigmoid mucosa was assessed by using proliferating cell nuclear antigen. The proliferating cell nuclear antigen index of the whole crypt and of the upper third was separately evaluated before and after 10-day rifaximin (400 mg b.d.) therapy. RESULTS: Proliferating cell nuclear antigen index in the upper third of the crypt was significantly higher in the diverticular patients (median: 25, range: 14-32) as compared with controls (median: 15, range: 5-20) (P = 0.038), and it was not reverted by rifaximin therapy. No difference of the proliferating cell nuclear antigen index of the whole crypt was detected between cases (median: 27, range: 23-44) and controls (median: 25, range: 18-42) (P = 0.6). CONCLUSIONS: Our data showed an upward shifting of cellular proliferation in the sigmoid mucosa of patients with diverticular disease. Because of rifaximin failure in reversing this alteration, factors other than the bacterial load should probably be investigated.

Case-Control Studies↗
PubMed2004

Sequential treatment for Helicobacter pylori does not share the risk factors of triple therapy failure.

BACKGROUND: Predicting factors for the outcome of conventional Helicobacter pylori triple therapy have been identified. Of these, the presence of the CagA gene is a strong predictor of successful treatment. Our preliminary data show that this factor becomes irrelevant when sequential therapy is used. AIM: To identify predicting factors for the outcome of H. pylori eradication using two therapeutic schemes (triple and sequential) of equal duration (10 days). METHODS: Ninety-six patients with H. pylori infection were randomly assigned to receive one of the following therapeutic schemes: group A: rabeprazole (20 mg b.d.) plus amoxicillin (1 g b.d.) for 5 days, followed by rabeprazole (20 mg b.d.) plus tinidazole (500 mg b.d.) and clarithromycin (500 mg b.d.) for a further 5 days; group B: rabeprazole (20 mg b.d.) plus amoxicillin (1 g b.d.) and clarithromycin (500 mg b.d.) for 10 days. Age, sex, smoking, endoscopic and histological findings, and CagA and VacA status were considered as candidates for a model of multivariate analysis which used therapeutic outcome as the dependent variable. CagA and VacA status were assessed by polymerase chain reaction on DNA isolated from gastric antral specimens. RESULTS: The sequential scheme was significantly more effective than prolonged triple therapy (P < 0.05). Smoking (P < 0.001) and the absence of the CagA gene (P < 0.05) were significantly associated with the failure of triple therapy, but the effectiveness of sequential treatment was not predicted by these factors. CONCLUSION: Our data suggest that sequential therapy is not affected by bacterial and host factors which have, until now, predicted the outcome of conventional eradication treatments.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2003

Second harmonic imaging improves trans-abdominal ultrasound detection of biliary sludge in 'idiopathic' pancreatitis.

BACKGROUND: Recently, biliary sludge has been strongly correlated with 'idiopathic pancreatitis'. It is often diagnosed by trans-abdominal ultrasonography, despite the low sensitivity of this investigation. New scanners, using second harmonic imaging, may improve the quality of the echographic picture. AIM: To verify the impact of this methodology on the detection of biliary sludge in patients with 'idiopathic' pancreatitis. METHODS: Fifty patients with 'idiopathic' pancreatitis observed over a 18-month period entered the study. Exclusion criteria were gall-bladder stones, polyps, clinical conditions related to biliary sludge development and haemolytic disorders. Patients were assessed blind by two operators using either conventional ultrasonography or second harmonic imaging. The parameters of diagnostic quality of both examinations were evaluated using, as the gold standard, microscopic examination of the gall-bladder content collected at endoscopy after cholecystokinin infusion. RESULTS: An improvement in sensitivity, specificity, efficiency and negative predictive value was obtained by second harmonic imaging compared with conventional ultrasonography. CONCLUSIONS: Second harmonic imaging, in our experience, is a reliable non-invasive tool for the diagnosis and follow-up of biliary sludge in the course of 'idiopathic' pancreatitis.

Acute Disease↗
PubMed2003

Tumor necrosis factor alpha and apoptosis in Helicobacter pylori related progressive gastric damage: a possible mechanism of immune system involvement in epithelial turnover regulation.

Helicobacter pylori (HP) related inflammation is mediated by tumour necrosis factor alpha (TNFalpha), which "in vitro" increases epithelial apoptosis in response to infection. In the early stages of HP gastritis, a raised epithelial apoptosis occurs; this phenomenon becomes less evident with progression towards intestinal metaplasia. Aim of our study was to analyze "in vivo" mucosal TNFalpha in relation to epithelial apoptosis in the progression of HP related histological damage. Antral biopsies from 20 HP positive patients were retrospectively studied: 10 with and 10 without intestinal metaplasia (IM and CG group respectively); samples of 10 dyspeptics with normal HP negative stomach (N) were used as control. The following parameters were evaluated by immunohistochemistry: 85 kDa caspase-cleaved fragment (p85) of human poly (ADP-ribose) polymerase (PARP) labelling index (LI) as marker of apoptosis and TNFalpha LI in stromal cells as marker of inflammatory response. Both epithelial apoptosis and mucosal TNFalpha expression were higher in chronic active gastritis compared to intestinal metaplasia and controls (PARP and TNFalpha LI: CG > IM > N; ANOVA & Student-Neumann-Keuls; p < 0.05 and p < 0.01, respectively). Pearson's coefficient showed a significant correlation between PARP and TNFalpha LI in IM and CG groups. Our data show that mucosal TNFalpha, similarly to what suggested "in vitro", may be related "in vivo" to epithelial apoptosis thus suggesting a possible mechanism for immune system involvement in the control of gastric epithelial turnover.

Adult↗
PubMed2001

Vertical transmission of hepatitis C virus in a cohort of 2,447 HIV-seronegative pregnant women: a 24-month prospective study.

BACKGROUND: Mother to infant transmission of hepatitis C virus (HCV) has been extensively studied in mothers with human immunodeficiency virus (HIV) infection, whereas fewer data are available on the vertical HCV transmission in HIV-negative women. METHODS: Between January 1995 and June 1997, 78 consecutive HCV-positive/HIV-negative women with their offspring entered this prospective study aimed to define the prevalence of and risk factors for HCV vertical transmission. Risk factors for HCV were carefully sought, and HCV viral load and genotype were determined in all positive mothers. The infants were tested for alanine aminotransferase (ALT) and HCV-RNA at birth and at 4, 8, 12, 18, and 24 months of age. RESULTS: Eight of 60 (13.3%) infants born to HCV-RNA positive mothers acquired HCV infection, but only 2 (3,3%) were still infected by the end of follow-up. Infants' genotypes matched that of the mothers. ALT levels were in the normal range in all study subjects throughout the follow-up. High maternal viral load (P < 0.05), possession of HCV risk factors (P < 0.004), and history of blood transfusion (P < 0.05) were associated with increased risk of HCV vertical transmission. CONCLUSIONS: This long-term prospective study shows that, although vertical transmission from HIV-negative mothers occurs in 13% of cases, there is a high rate of spontaneous viral clearance (75%). High maternal viral load and mothers belonging to HCV risk categories were the only variables predictive of the vertical transmission.

Adult↗
PubMed2000

Molecular mechanisms of augmenter of liver regeneration as immunoregulator: its effect on interferon-gamma expression in rat liver.

BACKGROUND: We have shown that the administration of exogenous Augmenter of Liver Regeneration protein in intact rats i) regulates mitochondrial gene expression by inducing the transcription and translation of the nuclear-encoded mitochondrial transcription factor A, and ii) inhibits the lytic activity of liver-resident Natural Killer cells. AIMS: The present investigation was carried out to study the effect, in intact rats, of exogenous administration of Augmenter of Liver Regeneration protein on Interferon-gamma, a cytokine produced by activated Natural Killer cells and known to control the expression of mitochondrial transcription factor A, a nuclear gene responsible for mitochondrial metabolism. METHODS: Interferon-gamma was measured as messenger RNA in liver-derived mononuclear leukocytes and as protein in liver-derived Natural Killer cells after a single injection of Augmenter of Liver Regeneration protein. RESULTS: The data obtained demonstrate that: i) in intact rats, Augmenter of Liver Regeneration protein administration induces a reduction of Interferon-gamma in the liver-resident Natural Killer cells and ii) the administration of Interferon-gamma in 70% hepatectomized rats is followed by a significant reduction both of the mitochondrial transcription factor A expression and of liver regeneration. CONCLUSIONS: These data demonstrate the pivotal role of Augmenter of Liver Regeneration as Growth Factor and as immunoregulator by controlling, through Interferon-gamma levels, the mitochondrial transcription factor A expression and the lytic activity of liver-resident Natural Killer cells.

Animals↗
PubMed1999

Complications of tissue expansion in a public hospital.

Avoidance of complications in tissue expansion requires careful outpatient observation and consistent follow-up-two factors that are difficult to manage in a city hospital-based population. To determine the complication rate of tissue expanders in a given population, the authors reviewed retrospectively 34 tissue expanders placed in 30 patients at a New York City public hospital over a 7-year period from 1989 to 1996. The mean age of the patients at the time of insertion was 25 years (range, 11 months-65 years). The most common conditions for treatment were nevi (N = 11), burn scars (N = 8), breast reconstructions (N = 8), and spina bifida (N = 4). Complications occurred in 22 of 34 expanders (65%). Complications included deep infection (N = 11), exposure (N = 7), breakdown of the surgical wound (N = 4), cellulitis (N = 3), drainage (N = 1), and deflation (N = 1). Major complications resulted in premature removal in 13 of 34 expanders (38%). Minor complications leading to successful completion of the expansion process occurred with 9 of 34 expanders (27%). No complications were recorded in the remaining 12 of 34 expanders (35%). Although tissue expansion is a potentially safe and effective method of reconstruction, this review should alert the surgeon to the distinct challenges that may be encountered in the public hospital.

Adolescent↗
PubMed1999

Treatment of a neuroma-in-continuity of the peroneal nerve with nerve bypass grafts--a case report.

Treatment of neuroma-in-continuity involves neurolysis or resection with interposition nerve grafting of the involved segment. These techniques may be complicated by loss of remaining conduction through axons that were intact prior to surgical neurolysis or grafting. The authors have shown previously that axonal regeneration occurs in an autologous bypass graft in the rat model. They applied this technique to a neuroma-in-continuity of the peroneal nerve of a 22-year-old woman who sustained an injury to the peroneal nerve after arthroscopic surgery, with excellent results. Nerve bypass may be the procedure of choice for treatment of neuroma-in-continuity.

Adult↗
PubMed1999

The use of subatmospheric pressure dressing for the coverage of radial forearm free flap donor-site exposed tendon complications.

Since its description in China in 1978, the radial forearm free flap has become a workhorse for the reconstructive surgeon. However, the flap has known disadvantages in complications of the wrist donor site. Skin graft breakdown with exposure of the flexor tendons of the wrist is the most common. The authors describe in a patient series a new treatment for this complication. They used subatmospheric pressure dressing to stimulate granulation tissue coverage of the tendon and to facilitate epithelialization. As many as one third of all patients undergoing radial forearm free flaps develop exposed tendon complications and may benefit from Vacuum Assisted Closure (VAC) therapy.

Aged↗
PubMed1999

Helicobacter pylori and nonulcer dyspepsia in childhood: clinical pattern, diagnostic techniques, and bacterial strains.

BACKGROUND: This is a report of the results of a multicenter study performed in children with dyspepsia from five pediatric centers in Puglia, a region in southern Italy. In the study, clinical features of Helicobacter pylori infection, the reliability of diagnostic techniques, and the involvement of bacterial strains were examined. METHODS: Fifty-three outpatients with dyspepsia enrolled in our study and compiled a diary recording clinical symptoms in patients before they underwent the following diagnostic techniques: endoscopy, biopsy for histologic analysis, rapid urease test, 13C urea breath test, serology specific for immunoglobulin (Ig)G and anti-CagA and VacA. RESULTS: H. pylori showed a prevalence of 30.2% (n = 16). Histologic positivity was seen in all patients at the antral level (H. pylori-associated chronic gastritis). In the gastric body, bacterial chronic active gastritis was present only in six patients (H. pylori-associated chronic pangastritis). Clinical evaluation showed a significant difference in favor of subjects positive for H. pylori only for epigastric burning and/or pain (p < 0.001). The comparison of results of diagnostic tests, using histology as the gold standard, showed sensitivity and specificity of more than 93% for 13C urea breath test and more than 85% for rapid urease test and serology. Anti-CagA antibodies were found in 64.3% and anti-VacA antibodies in 42.8% of H. pylori-positive patients. CONCLUSIONS: H. pylori prevalence in children with dyspepsia from the geographic area studied is comparable with that found in other developed countries. Approximately 50% of the studied patients were infected by cytotoxic strains. The urea breath test was the most reliable noninvasive diagnostic tool and is suitable for routine use, although endoscopy with histologic assessment remains the definitive investigation and is particularly important in patients with positive serology for CagA and VacA. Finally, the frequency of aggressive strains in our region seems to affect the clinical pattern; this emphasizes the importance of definitive diagnosis in children and offers a new role for serology.

Adolescent↗
PubMed1999

Immunohistochemical detection of Helicobacter pylori vacuolating cytotoxin in the hepatocytes of patients with isolated hypertransaminasaemia.

BACKGROUND AND AIM: Even if different Helicobacter species can colonise animal livers and induce hepatitis, there is no evidence that Helicobacter pylori can damage this organ and only a potential capacity of cytotoxic strains to increase transaminases in humans has been suggested. We have, therefore, carried out an immunohistochemical study on vacuolating cytotoxin in the hepatocytes of subjects with isolated hypertransaminasaemia. PATIENTS, METHODS AND RESULTS: Five male patients with isolated hypertransaminasaemia without signs of known causes of liver diseases were studied. Endoscopy demonstrated diffuse mucosal hyperaemia in 3 patients and duodenal ulcer in one. Histology revealed active chronic pangastritis in all. Helicobacter pylori was assessed by histology and culture and its cytotoxity, demonstrated by positive immunoblotting for both anti-CagA and VacA. Percutaneous liver biopsy showed minimal changes. Hepatic and gastric sections were tested either with autologous serum and rabbit antibody to VacA toxin. Immune reaction was revealed by immunoperoxidase. Both autologous sera and anti-VacA toxin antibody showed a reaction with a similar pattern which involved 60% of hepatocytes. Anti-VacA toxin showed a reaction to gastric epithelial cells and autologous sera to parietal cells in 4/5 patients. All patients received triple therapy and eradication of Helicobacter pylori was assessed by urea breath test. Serum transaminase levels 3 months after eradication, are still abnormal. CONCLUSIONS: Our immunohistochemical findings suggest that vacuolating cytotoxin could reach the hepatocytes of patients suffering from both isolated hypertransaminasaemia and infection by cytotoxic strains of Helicobacter pylori. Nevertheless, a clear relationship between these two condition remains uncertain.

Adult↗
PubMed1997

[Prevalence of Helicobacter pylori antibodies in patients with kidney transplantation].

INTRODUCTION: Our target was to verify if belonging to a selected group of patients, who have undergone a kidney transplantation and before that suffered from high level of uremia sometimes with border line levels , could be a risk factor for acquiring HP antibodies. MATERIALS AND METHODS: We evaluated in 23 patients, with an average age of 16.3, attending our Day-Hospital Unit to be followed up after a kidney transplant, the prevalence of anti-HP antibodies, measured in serum by the ELISA method. The prevalence in this group has been compared with that observed in a healthy cohort of 36 people. RESULTS: Antibodies were present in 31.8% of our patients without any correlation with age, age of transplant, serum urea level, cyclosporinemia, total lgG and IgA antibodies. DISCUSSION: In the end, kidney transplantation doesn't seem to be a risk factor for acquiring HP infection. Detecting HP antibodies can be a method to select patients that must undergo other strumental examinations.

English Abstract↗
PubMed1994

Role of adhesion molecules in leukocyte binding to endothelial cells adherent to vascular grafts.

BACKGROUND: The localization of leukocytes to vascular grafts is an essential part of healing and infection resistance. The mechanisms involved in this process are only partly understood. STUDY DESIGN: Human saphenous vein endothelial cells (HSVEC) were grown on control polystyrene culture ware and expanded polytetrafluoroethylene (ePTFE). The binding of monoclonal antibodies against the intercellular adhesion molecule (ICAM-1) and the E-selectin by adherent HSVEC was determined by flow cytometry. Peripheral blood leukocytes (PBL) were cocultured with HSVEC adherent to ePTFE and leukocyte binding was determined with and without the addition of a protein kinase C inhibitor. RESULTS: HSVEC adherent to ePTFE constitutively bound anti-ICAM-1 antibodies, which were attenuated by the protein kinase C inhibitor, H-7. HSVEC adherent to ePTFE bound significantly greater numbers of leukocytes than those on control (58 versus 41 percent, p < 0.05). Incubation with H-7 decreased leukocyte binding to HSVEC significantly (p < 0.005). Coculture of PBL with HSVEC adherent to ePTFE caused a tenfold increase in binding of anti-E-selectin antibodies (p < 0.0005). CONCLUSIONS: These data indicate that PBL binding to HSVEC adherent to ePTFE is, at least in part, ICAM-1 to HSVEC adherent to ePTFE is, at least in part, ICAM-1 and E-selection dependent.

Blood Vessel Prosthesis↗
PubMed1994

Immunohistochemical detection of sex steroid receptors in breast cancer using routine paraffin sections: comparison with frozen sections and enzyme immunoassay.

Estrogen and progesterone receptors (ER and PR) on 48 surgically removed breast cancers were evaluated by three methods: immunoenzymatic (ER/PR-EIA), immunohistochemical in frozen sections (ER/PR-ICA), and immunohistochemical in paraffin sections (ER/PR-PAR). The monoclonal antibodies H222 and KD68 were used for immunohistochemical detection of ER and PR, respectively. Immunohistochemical stains for pS2, an estrogen-regulated protein, were also done for compatibility with previous ER/PR-PAR studies. We assessed concordance with chi-square and Pearson's correlation coefficient. We concluded that ER/PR-PAR is the least sensitive of the three assays (90.9% ER, 88.5% PR) and, until appropriate technical and clinical validation is achieved, should not be used as a first-line assay. Also, because of this lower sensitivity, we recommended that pS2 evaluation always accompany ER/PR-PAR to facilitate distinction between clinical negatives and those due to irretrievably lost immunoreactivity. We also conclude that ER/PR-ICA is a good semi-quantitative method that, in combination with ER/PR-EIA, most accurately assesses receptor status.

Breast Neoplasms↗
PubMed1994

In situ detection of PCR-amplified HIV-1 nucleic acids in lymph nodes and peripheral blood in patients with asymptomatic HIV-1 infection and advanced-stage AIDS.

This study determined the in situ detection rate of polymerase chain reaction (PCR)-amplified human immunodeficiency virus type 1 (HIV-1) DNA and RNA in lymph nodes and peripheral blood CD4+ cells in six patients with asymptomatic HIV-1 infection and from six people who died of advanced AIDS. The lymph nodes of patients with asymptomatic infection showed expanded germinal centers where, on average, 20% of the CD21+ dendritic cells contained HIV-1 DNA. From 5 to 80% of the CD4+ cells in these lymph nodes contained HIV-1 DNA, as compared with 1-11% of the CD4+ peripheral blood mononuclear cells. The infection in most cells was latent in the asymptomatic group. In contrast, the lymph nodes of patients with advanced AIDS showed marked depletion of both dendritic and CD4+ cells. The majority of the remaining CD4+ cells in the lymph nodes and blood showed PCR-amplified viral DNA and cDNA sequences suggesting the presence of genomic and multiple spliced transcripts. It is concluded that asymptomatic HIV-1 infection is associated with a wide range of latent to active viral-positive CD4+ lymphocytes and dendritic cells in the lymph nodes. Progression to AIDS is characterized by active viral replication in many of the remaining CD4+ cells in the lymph nodes and blood.

Acquired Immunodeficiency Syndrome↗