PubMed Health⌕ Search

Biomedical subjects

Francesco Luzza

Publications and source records attributed to Francesco Luzza.

14 recordsLinked to original sources
PubMed2007

Interleukin-12 drives the Th1 signaling pathway in Helicobacter pylori-infected human gastric mucosa.

In this study we examined mechanisms that regulate T-helper lymphocyte 1 (Th1) commitment in Helicobacter pylori-infected human gastric mucosa. The levels of gamma interferon (IFN-gamma), interleukin-4 (IL-4), and IL-12 in total extracts of gastric biopsies taken from H. pylori-infected and uninfected patients were determined by an enzyme-linked immunosorbent assay. The levels of signal transducer and activator of transcription 4 (STAT4), STAT6, and T-box expressed in T cells (T-bet) in total proteins extracted from gastric biopsies were determined by Western blotting. Finally, the effect of a neutralizing IL-12 antibody on expression of Th1 transcription factors and the levels of IFN-gamma in organ cultures of H. pylori-infected biopsies was examined. Increased levels of IFN-gamma and IL-12 were found in gastric biopsy samples of H. pylori-infected patients compared to the levels in uninfected patients. In addition, H. pylori-infected biopsies exhibited high levels of expression of phosphorylated STAT4 and T-bet. Higher levels of IFN-gamma and expression of Th1 transcription factors were associated with greater infiltration of mononuclear cells in the gastric mucosa. By contrast, production of IL-4 and expression of phosphorylated STAT6 were not associated with the intensity of mononuclear cell infiltration. In ex vivo organ cultures of H. pylori-infected biopsies, neutralization of endogenous IL-12 down-regulated the expression of phosphorylated STAT4 and T-bet and reduced IFN-gamma production. Our data indicated that IL-12 contributes to the Th1 cell commitment in H. pylori-infected human gastric mucosa.

Adult↗
PubMed2006

Giardia lamblia infection in patients with irritable bowel syndrome and dyspepsia: a prospective study.

AIM: To evaluate the prevalence of Giardia lamblia (G. lamblia) infection in patients with irritable bowel syndrome (IBS) and dyspepsia and to establish which is the most accurate test to diagnose the infection in this setting. METHODS: One hundred and thirty-seven patients who consecutively attended the Outpatient Gastroenterology Clinic for the first time between January 2002 and December 2003 due to symptoms of IBS and/or dyspepsia were recruited. All patients underwent clinical evaluation, first-step haematology and chemistry tests, serologic assays for celiac disease, lactose-H(2) breath test, abdominal ultrasonography, and esophagogastroduodenoscopy. Helicobacter pylori status was evaluated. In patients with symptoms of IBS older than 45 years, colonoscopy was also performed. In all patients, duodenal biopsies and stool samples were examined for trophozoites and cysts of G. lamblia by several methods. RESULTS: G. lamblia was identified in 9 patients. The following diagnoses were also made: IBS (100/137, 73%), functional dyspepsia (62/137, 45%), organic dyspepsia (33/137, 24%), and lactose intolerance (75/137, 55%). A significant association was found between giardiasis and H pylori infection (c2=6.632, OR=12.4, CI=1.5-68.1). There were no symptoms that reliably allowed the recognition of giardiasis. Direct search of the parasite in duodenal biopsy and stool sample examinations gave concordant results in all cases while histological examination of duodenal biopsies displayed a low sensitivity (e.g., 22.2%). CONCLUSION: In this consecutive series, diagnosis of G. lamblia infection accounted for 6.5% of patients with IBS and dyspepsia. Duodenal biopsies for diagnosis of giardiasis may be unnecessary if stool sample examination is performed.

Adult↗
PubMed2006

Epidemiology of Helicobacter pylori infection.

Differences may occur in the mode of transmission of Helicobacter pylori between developed and developing countries: direct human-to-human contacts have been suggested as the primary route in the former while the fecal-oral route, also, through contaminated water, in the latter. Data on intrafamilial transmission of H. pylori among children continue to be produced. The importance of low socioeconomic conditions on the acquisition of H. pylori infection has been confirmed in a number of population-based studies. Due to the improvement of living standards, the prevalence of the infection has fallen dramatically in many countries. It varies from 8.9 to 72.8% among children from developed and developing countries, respectively, the re-infection rate being also significantly higher in the latter. Conflicting data have been reported on the effect of breastfeeding against H. pylori colonization in infancy as well as on the occupational risk for acquiring H. pylori. This review summarizes recent results from the literature on these topics.

Adolescent↗
PubMed2005

Bundle branch block in alternate beats during 2:1 atrial flutter.

This presentation deals with a case of atrial flutter. During 2:1 A/V conduction, the QRS complexes showed a regular alternation of narrow beats and wide beats with a typical configuration of left bundle branch block. In contrast, pauses resulting from 4:1 A/V conduction ratio always resulted in narrow beats. Disappearance of left bundle branch block with long R-R intervals demonstrated that the block was tachycardia-dependent or phase 3. Analysis of the tracing suggested that narrowing of QRS complexes in alternate beats was due to supernormal left bundle branch conduction associated with retrograde concealed conduction into the anterogradely blocked bundle branch.

Aged↗
PubMed2005

[Atrial septal aneurysm: a true embolic source?].

Atrial septal aneurysm (ASA) is a well-recognized cardiac abnormality of uncertain clinical significance. It has early been reported as an unexpected finding during autopsy, but it may also be diagnosed in living patients by echocardiographic techniques. An association between ASA and focal cerebral ischemic events has been suggested. Nevertheless, the role of ASA as a risk factor for cerebral ischemia is poorly defined. Several studies have demonstrated a significantly higher proportion of ASA in the patients referred for transesophageal echocardiography after a cerebral ischemic event of unknown cause. However, ASA is often associated with other cardiac abnormalities such as patent foramen ovale, atrial septal defects, as well as mitral valve prolapse or atrial arrhythmias. Due to the fact that these abnormalities are also possible sources of cardiac emboli it is even more difficult to assess the embolic potential of an ASA, independently. In this review, we have examined most of the papers on this topic to try to define the prevalence of ASA in the stroke patients and how this abnormality could be a risk factor for recurrences of cerebrovascular events.

Brain Ischemia↗
PubMed2004

Syncope of psychiatric origin.

BACKGROUND: A well-defined relationship between transient loss of consciousness and a psychiatric disorder has not yet been established. REVIEW SUMMARY: In the past, psychiatric origin of syncope was considered to be uncommon, occurring only in 1-7% of patients with syncope. Recently, a much higher incidence ranging from 20 % to 81 % has been reported. One main difficulty may be an incorrect approach to the problem. Authors generally defined syncope as every loss of consciousness without regard to the specific pathophysiology of the symptom. Moreover, identification of psychiatric origin of transient unconsciousness may be very difficult. Some clinical features can suggest the diagnosis; none of them, however, is an identification mark. Thus, in most cases, the diagnosis may be certain only when direct observation of the clinical event occurs. A transient loss of consciousness may be related to a psychiatric disorder when the symptom ensues in the presence of normal values of both blood pressure and heart rate. The phenomenon resembles syncope and has been defined as "pseudosyncope". Unfortunately, direct observation of a spontaneous event is very uncommon. Recently, few cases of pseudosyncope induced by Tilting test (HUTT) have been reported. In these patients, HUTT revealed a previously unknown psychiatric disorder. In our experience, pseudosyncope represented an uncommon HUTT outcome in all patients referring for unexplained syncope; in selected patients, however, HUTT may be useful in the early identification of psychiatric syncope. CONCLUSIONS: Prospective researches are needed to assess HUTT utility in evaluating patients whose clinical features suggest psychiatric origin of transient loss of consciousness.

Humans↗
PubMed2004

Extracellular signal-regulated protein kinase mediates interleukin 17 (IL-17)-induced IL-8 secretion in Helicobacter pylori-infected human gastric epithelial cells.

Helicobacter pylori-induced mucosal inflammation results in high production of interleukin 17 (IL-17), a potent inducer of IL-8 in gastric epithelial cells. The aim of this study was to investigate signaling pathways by which IL-17 regulates IL-8 production in human gastric epithelial cells. Activation of mitogen-activated protein (MAP) kinases in both IL-17-stimulated MKN28 cells and epithelial cells isolated from H. pylori-colonized gastric mucosa was assessed by Western blotting. In IL-17-stimulated MKN28 cells the activation of activatior protein 1 (AP-1), nuclear factor (NF)-IL-6, and NF-kappaB was also assessed by electrophoretic mobility shift assay. IL-8 production was evaluated by reverse transcription-PCR and enzyme-linked immunosorbent assay (ELISA) both for IL-17-stimulated MKN28 cells treated with specific MAP kinase inhibitors and gastric biopsy cultures treated with a neutralizing IL-17 antibody. Serum from H. pylori-infected patients was tested for immunoglobulin G response to CagA by ELISA. Treatment of MKN28 cells with IL-17 caused activation of extracellular signal-regulated protein kinase 1/2 (ERK 1/2) but not other MAP kinases and had the downstream effects of AP-1 and NF-kappaB activation and IL-8 synthesis. Blocking ERK 1/2 activity inhibited AP-1-mediated, but not NF-kappaB-mediated, IL-8 induction. Enhanced activation of ERK 1/2 was seen in gastric epithelial cells isolated from H. pylori-infected patients in comparison to uninfected controls, and this was associated with high IL-8. These effects were even more pronounced in patients seropositive for CagA than in seronegative ones. In gastric biopsy cultures, the addition of a neutralizing IL-17 antibody decreased ERK 1/2 activation, thus resulting in a significant inhibition of IL-8. In H. pylori-colonized gastric epithelial cells, IL-17-induced IL-8 synthesis is associated with and depends at least in part on the activation of ERK 1/2 MAP kinase.

Adult↗
PubMed2003

Anatomical M-mode: an old-new technique.

The M-mode (motion mode) technique has improved the diagnostic possibilities of echocardiography due to its high temporal resolution. The use of a two-dimensional (2D) image as a basis for M-mode analysis at a defined line, independent of the transducer orientation, namely the anatomic M-mode (AMM), has been proposed from the beginning of 2D echocardiography. For several years, however, this could not be accomplished due to several reasons including the limited digital memory, the relatively rough pixels of 2D images, and the low temporal resolution of the screen. The AMM has been improved by the "fully digital" machines. These are able to provide a series of digital data (direction, position, and timing) relative to any single echo received from any point of the tissue. AMM analysis, thus, can be performed in any direction, as a "normal" monodimensional echocardiogram. With respect to traditional M-mode, AMM permits a more detailed analysis of cardiac chambers diameters obtained by linear measurements, regional wall motion of the left ventricle (both at rest and during stress), and location of accessory pathways. In particular, the assessment of left ventricular regional wall motion represents the most important goal of this new technique, which results in marked reduction or even elimination of the limitations due to the subjective character of wall motion evaluation with 2D echocardiography.

Echocardiography↗
PubMed2002

Comparison between transesophageal echocardiography and transthoracic echocardiography with harmonic tissue imaging for left atrial appendage assessment.

BACKGROUND: Transesophageal echocardiography (TEE) is the method of choice for evaluating both anatomy and function of left atrial appendage (LAA). In contrast, conventional transthoracic echocardiography (TTE) does not result in images of sufficient quality to explore LAA. HYPOTHESIS: The aim of this study was to evaluate the potential role of TTE with harmonic frequency imaging (HFI) for assessing LAA normal anatomy and function. METHODS: The study group comprised 25 patients, (9 men, 16 women, mean age 51 years, range 20-82). The TTE as sessment of LAA both in fundamental frequency imaging (FFI) and HFI was performed using the apical two-chamber view, the longitudinal two-chamber view was used for TEE assessment of LAA. According to image quality, images were categorized into three classes: A: good quality, B: sufficient quality, C: poor quality. RESULTS: Transthoracic echocardiography conventional imaging allowed sufficient LAA visualization (class B) in only 5 of 25 patients (20%); the HFI resulted in adequate LAA visualization in 23 of 25 patients (92%). Images were of good quality (class A) in 18 of 23 patients and of sufficient quality (class B) in 5 of 23 patients. Transesophageal echocardiography achieved good quality images in 24 of 25 patients (96%). Average LAA maximum area determined by HFI and TEE was 3.46 +/-1.17 and 3.59 +/- 1.16 cm2, respectively; LAA minimum area was 1.81 +/- 0.98 and 1.77 +/- 0.97 cm2, respectively. Percent LAA area change was 51 +/- 16.5 and 50.9 +/- 16% with HFI and TEE, respectively. Statistical analysis showed no difference between the data obtained with the two methods. CONCLUSIONS: The results suggest that HFI TNE may be a useful tool for the exploration of LAA.

Adult↗
PubMed2002

Antral nodularity and positive CagA serology are distinct and relevant markers of severe gastric inflammation in children with Helicobacter pylori infection.

BACKGROUND: The aim of this study was to assess whether the endoscopic finding of antral nodularity and serum IgG antibodies to CagA are associated with higher grades of gastric inflammation. MATERIALS AND METHODS: The comprehensive data of two previously published trials were reanalysed. One hundred and fifty-three children (median age 9.5 years) who underwent gastroscopy were included. Biopsy specimens from the antrum and corpus were taken to assess Helicobacter pylori status, gastritis score and lymphoid follicles. During endoscopy, antral nodularity was noted. Serum samples were assayed for IgG antibodies to CagA. RESULTS: The presence of antral nodularity (nod+) and positive CagA serology (CagA+) were each found in 32 of the 77 (41.5%) children who had evidence of H. pylori infection. Cross tabulation showed that 20 children (26%) were nod+/CagA+, 12 (15.5%) nod+/CagA-, 12 (15.5%) nod-/CagA+ and 33 (43%) nod-/CagA-. Gastritis score was significantly lower in nod-/CagA- children than in nod+/CagA- (p =.004), nod-/CagA+ (p =.002) and nod+/CagA+ (p <.001), both in the antrum and corpus. Completely normal gastric histology was only found in the nod-/CagA- subgroup of H. pylori-infected children (eight of 33, 24%). Regression analysis showed that antral nodularity and positive CagA serology were related to severe gastric inflammation independently of each other and age. Separate analysis showed that inflammation (p <.001), activity (p <.001) and H. pylori density (p =.002) scores were significantly lower in nod-/CagA- children compared with nod+/CagA+ children. The number of lymphoid follicles in the gastric mucosa was related to antral nodularity (p =.003) and positive CagA serology (p =.043), independently of each other. CONCLUSIONS: Antral nodularity and positive CagA serology are distinct and relevant markers of severe gastric inflammation in children with H. pylori infection. The lack of both findings in the same child reflects low-grade or no gastritis.

Adolescent↗