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Biomedical subjects

F Luzza

Publications and source records attributed to F Luzza.

At least 55 records · Page 3Linked to original sources
PubMed1997

Salivary immunoglobulin G assay to diagnose Helicobacter pylori infection in children.

An in-house enzyme-linked immunosorbent assay (ELISA) for measurement of Helicobacter pylori-specific immunoglobulin G (IgG) and IgA in saliva was evaluated by comparison with histopathologic (Giemsa staining) and biochemical (urease quick test) examination of gastric biopsy specimens obtained from 112 children referred for diagnostic gastroscopy. Serum H. pylori IgG was also measured in a subgroup of 50 children by the same ELISA. Salivary H. pylori IgG levels were significantly higher in H. pylori-positive (n = 57) than in H. pylori-negative (n = 55) children (P < 0.001). The sensitivity and specificity of the salivary IgG test were 93 and 82%, respectively; the positive and negative predictive values were 84 and 92%, respectively; and the accuracy was 87.5%. Salivary H. pylori IgA did not distinguish H. pylori-positive from H. pylori-negative children. The performance of serum H. pylori IgG was slightly (3 to 6%) better than that of salivary H. pylori IgG. The salivary IgG test can be considered a useful tool for the screening of H. pylori infection in children.

Adolescent↗
PubMed1997

Seroepidemiology of Helicobacter pylori infection and hepatitis A in a rural area: evidence against a common mode of transmission.

BACKGROUND AND AIMS: Recent studies have shown that the age-specific seroprevalence of H pylori infection parallels hepatitis A (HAV), suggesting similar modes of transmission. The aim of this study was to investigate the seroepidemiology of H pylori and HAV in the same setting. PATIENTS: A sample of 705 resident subjects (273 men, age range 1-87 years, median 50) who attended the outpatient medical centre of the rural town of Cirò, Southern Italy (11,000 inhabitants) for blood testing were recruited. METHODS: All subjects completed a structured questionnaire. A serum sample was drawn from each subject and assayed for H pylori IgG by a validated in house enzyme linked immunosorbent assay. Antibodies to HAV were determined in 466 subjects (163 men, age range 1-87 years, median 49). A measure of agreement between H pylori and HAV seropositivity, the kappa statistic, was used. RESULTS: Overall, 446 (63%) subjects were seropositive for H pylori. Of the 466 subjects screened for both H pylori and HAV, 291 (62%) were seropositive for H pylori and 407 (87%) for HAV. Cross-tabulation of these data showed that 275 (59%) were seropositive and 43 (9%) seronegative for both H pylori and HAV, 16 (3%) were seropositive for H pylori, and 132 (28%) were seropositive for HAV (OR = 5.6, CI 3 to 10). There was a parallel, weakly correlated (r = 0.287) rise in the seroprevalence of the two infections with increasing age. However, the agreement between H pylori and HAV seropositivity was little better than chance (kappa = 0.21) and in those aged less than 20 years it was worse than chance (kappa = -0.064). Furthermore, multiple logistic regression analysis did not show any risk factor shared by both infections. CONCLUSIONS: The correlation between H pylori and HAV reflects the age-specific seroprevalence of both infections rather than a true association. This study provides evidence against a common mode of transmission of H pylori and HAV.

Adolescent↗
PubMed1997

[Unidirectional block and longitudinal dissociation in an accessory pathway induced by radiofrequency].

This report describes an unusual arrhythmia due to partial damage of an accessory pathway by radiofrequency energy delivered during a catheter ablation procedure. The following phenomena were observed after the first radiofrequency current application: a) manifest anterograde conduction over the Kent bundle was abolished, so that preexcitation disappeared; b) concealed anterograde conduction over the accessory pathway was interrupted, resulting in initiation of orthodromic re-entrant tachycardia by any sinus impulse; c) retrograde conduction through the accessory pathway was impaired, but still present, and a pattern of longitudinal dissociation manifested; this was suggested by alternation of the R-P intervals, that during orthodromic tachycardia were alternatively long and short. Following a second radiofrequency application, the R-P interval during orthodromic tachycardia became markedly prolonged (0.36 sec), to the extent that the pattern mimicked a form of atrial or sinus tachycardia. Retrograde accessory pathway conduction was totally interrupted following a third radiofrequency energy application.

Adult↗
PubMed1996

Helicobacter pylori-specific IgG in chronic haemodialysis patients: relationship of hypergastrinaemia to positive serology.

BACKGROUND: Chronic haemodialysis (HD) patients frequently suffer from dyspeptic symptoms and hypergastrinaemia is a common finding in these patients. Helicobacter pylori (H. pylori) infection is associated with dyspepsia and hypergastrinaemia. METHODS: The aim of this study was to determine whether H. pylori is frequently found in HD patients and to explore the relationship of H. pylori with dyspeptic symptoms and/or hypergastrinaemia in these patients. Serum H. pylori specific IgG were measured by an in-house enzyme-linked immunosorbent assay (sensitivity and specificity is 97% and 91% respectively) in 103 chronic HD patients. The patients (53 M, 50 F, mean age f60 +/- 13 years) completed a questionnaire exploring the type, frequency and intensity of dyspeptic symptoms. Fasting plasma gastrin levels were also measured. Serum and plasma samples from 103 hospital patients matched for age, sex and dyspepsia were use as controls. RESULTS: There was no significant difference in terms of serum H. pylori IgG between HD patients and controls (0.977 +/- 0.295 vs 1.046 +/- 0.306 OD respectively). The prevalence of subjects with positive serology was relatively high in both groups, but did not differ between HD patients (73%) and controls (78%). Dyspepsia was reported in 72 (70%) cases. There was no relationship between presence (and grading) of dyspepsia or type of dyspeptic symptoms and H. pylori serology. In the HD group, patients seropositive for H pylori had a significantly higher gastrinaemia than those who were seronegative: 598 +/- 413 ng/ml vs 309 +/- 252 ng/ml (P < 0.0001). The relationship between seropositivity for H. pylori and hypergastrinaemia was significant (P = 0.00038), after adjustment by multiple regression analysis for sex, age, smoking, alcohol, months on dialysis, renal function, drugs, and dyspepsia. CONCLUSIONS: Data of this study suggest that H. pylori may play a role in contributing to hypergastrinaemia of HD patients.

Dyspepsia↗
PubMed1995

Salivary specific IgG is a sensitive indicator of the humoral immune response to Helicobacter pylori.

In humans, salivary antibodies are secreted during humoral immune response. Helicobacter pylori infection is associated with systemic humoral immune response reflected by raised serum levels of specific IgG. The present study was aimed at exploring whether salivary concentrations of specific H. pylori IgG are a reliable indicator of H. pylori infection. Serum and salivary samples were obtained from 291 subjects attending the GI clinic and tested for H. pylori-specific IgG by a direct ELISA (94% sensitivity, 95% specificity for serum determinations) using a crude H. pylori sonicate as antigen. Data are given as optical density (mean +/- S.D.). Levels of salivary H. pylori IgG paralleled those of circulating specific IgG in the 291 subjects studied (0.981 +/- 0.431 vs. 0.777 +/- 0.682, respectively). A significant positive correlation was found between specific H. pylori IgG in sera and saliva samples (r = 0.981, P < 0.0001). An overall concordance between circulating and salivary H. pylori IgG was observed in 238 out of the 291 (81.7%) subjects. Salivary H. pylori IgG represent a sensitive marker of specific humoral immune response and they may substitute circulating H. pylori IgG measurement when sera samples are not available.

Adult↗
PubMed1995

Isotypic analysis of specific antibody response in serum, saliva, gastric and rectal homogenates of Helicobacter pylori-infected patients.

The relationship between systemic and local humoral immune response to Helicobacter pylori is poorly understood. To further address this issue we measured, using ELISA, H. pylori-specific IgG and IgA antibodies in serum, saliva, gastric and rectal homogenates of H. pylori-infected patients. A total of 107 patients who underwent upper GI endoscopy and/or sigmoidoscopy were studied. The isotypic pattern of H. pylori-specific antibodies appeared to differ at the serum, salivary, gastric and rectal mucosa level. Serum H. pylori IgG titers were higher than those of the serum-specific IgA. On the contrary, in saliva samples H. pylori IgA titers were higher than specific IgG titers. In gastric homogenates, specific IgG and IgA titers were similar. H. pylori-specific IgG were detectable in rectal homogenates but no or very low H. pylori-specific IgA were found in the same material. Furthermore, no difference was found in H. pylori IgG and IgA in serum, saliva and gastric homogenates between duodenal ulcer and non-ulcer dyspepsia patients. Data of the present study indicate that, in H. pylori-infected patients, the specific immune response is as follows: (1) it involves the secretory immune system; (2) it is paralleled by the specific salivary IgA; (3) it does not differentiate duodenal ulcer from non-ulcer dyspepsia patients; and (4) it does not take place in the large bowel.

Adult↗
PubMed1995

Evidence against an increased risk of Helicobacter pylori infection in dentists: a serological and salivary study.

BACKGROUND: An oral-to-oral route of transmission of Helicobacter pylori infection has been postulated, which is supported by the observation that H. pylori is present in the saliva and in dental plaque. On the basis of this assumption, an increased risk of H. pylori infection among dentists was postulated. METHOD: Serum and salivary H. pylori immunoglobulin (lg)G antibodies were measured in a group of practising dentists. For comparison we also studied a group of controls from the same urban area matched for age, sex, smoking habits, alcohol and non-steroidal anti-inflammatory drug consumption, and history of dyspepsia. RESULTS: There was no significant difference in serum H. pylori lgG antibodies titres between dentists and controls [optical density (OD) 0.991 +/- 0.588 versus 1.025 +/- 0.591, respectively]. Salivary H. pylori lgG were 0.693 +/- 0.726 and 0.661 +/- 0.614 OD in the dentists and control groups, respectively. The frequency of H. pylori-seropositive subjects did not differ between the two groups [22 out of 39 (56%) versus 46 out of 71 (64%)]. A positive saliva assay was found in 23 out of 39 (59%) dentists and in 44 out of 71 (62%) controls. The odds ratio for a dentist being H. pylori-positive was 0.7 (95% confidence interval 0.3-1.7) by serology and 0.9 (95% confidence interval 0.4-2.1) by salivary antibody assay. CONCLUSION: The data of this study do not support the concept that dentists are a high-risk group for H. pylori infection.

Adult↗
PubMed1995

Salivary-specific immunoglobulin G in the diagnosis of Helicobacter pylori infection in dyspeptic patients.

OBJECTIVES: Helicobacter pylori infection is arguably the most common chronic bacterial infection in humans. The high prevalence and the association with peptic ulceration and gastric cancer indicate that simple, noninvasive methods for diagnosis of the infection are needed. In this study, the accuracy of salivary diagnosis for H. pylori infection was assessed. METHODS: Saliva and serum samples of 152 dyspeptic patients were tested for H. pylori IgG and IgA by an in-house ELISA. All patients underwent gastroscopy with biopsy. RESULTS: One hundred thirty-one patients (86%) were found to be H. pylori positive on histology. Duodenal ulcer was found in 67 patients; 85 had no macroscopic lesion. Salivary and serum H. pylori IgG as well as serum H. pylori IgA titers were significantly higher in H. pylori-positive than in H. pylori-negative patients. The sensitivity and specificity of salivary H. pylori IgG were 82% and 71%, respectively; the positive and negative predictive values were 95% and 40%, respectively; and the accuracy 81%. The corresponding figures for serum H. pylori IgG were 97% and 91%; 98% and 83%; and 96%. Those for serum H. pylori IgA were 80% and 52%; 91% and 30%; and 76%. The sensitivity of salivary H. pylori IgG in detecting duodenal ulcer was 83% (56/67) that of serum H. pylori IgG was 97% (65/67) (odds ratio = 0.15; confidence interval = 0.02-0.8; p = 0.02). CONCLUSIONS: Salivary H. pylori IgG was a fairly sensitive and accurate indicator of gastric H. pylori colonization, with a high positive predictive value in our population. Data, however, suggest that salivary H. pylori IgG measurements do not compare favorably with serology.

Adult↗
PubMed1994

Pseudo-atrioventricular dissociation caused by interpolated ventricular extrasystoles in the presence of dual atrioventricular nodal pathway.

This report describes a patient manifesting with ventricular extrasystoles. The pause occasioned by extrasystoles often is followed by narrow QRS complexes not preceded by P waves, but at times is followed by a sinus P wave. At first glance, the pattern suggests a diagnosis of atrioventricular (A-V) junctional escape complexes. Analysis reveals that ventricular extrasystoles are, in fact, interpolated; the sinus P wave that follows the extrasystole is conducted to the ventricles with a very prolonged P-R interval (up to 0.80 s). The phenomenon is due to the presence of a dual A-V nodal pathway. The sinus impulse that follows the extrasystole is blocked in the fast pathway but may still be conducted to the ventricles through the slow pathway, resulting i a very prolonged P-R interval.

Aged↗
PubMed1994

[Extrasystolic ventricular bigeminy in ventricular tachycardia].

A patient with recent myocardial infarction presented with premature ventricular contractions (PVCs), couplets, and runs of ventricular tachycardia (VT). Two types of ectopic complexes, labeled A and B, were present. Isolated PVCs, as well as the first complex in a couplet, were always type A beats. In contrast, the second beat in a couplet was always a type B beat. Any run of VT was initiated by a type A beat. Monomorphic VT was made only of type B complexes, apart from the first one. Several episodes of VT, however, reflected an alternation of type A and type B complexes with alternating cycle length. This is a manifestation of extrasystolic ventricular bigeminy where any VT impulse (type B) is followed by an extrasystole (type A). In addition, extrasystolic impulses affect the tachycardia, resetting its cycle.

Cardiac Complexes, Premature↗
PubMed1994

Circulating D dimer in inflammatory bowel disease.

An activated thrombogenesis has been reported in inflammatory bowel disease (IBD). In this study we evaluated whether a fibrin degradation product, the D dimer, is increased in patients with IBD. D dimer plasma levels were evaluated by sandwich ELISA in patients with Crohn's disease (24), ulcerative colitis (25), gastrointestinal (GI) disease controls (10), hospital controls (13) and healthy subjects (14). Circulating D dimer was significantly higher in ulcerative colitis (median 651; 95% CI 89-1275 ng/ml) than in healthy subjects (median 412; 95% CI 112-672 ng/ml; p = 0.002), Crohn's disease (median 466; 95% CI 6-931 ng/ml; p = 0.005) and GI disease controls (median 446; 95% CI 196-688 ng/ml; p = 0.023). In ulcerative colitis, plasma D dimer was related to inflammatory parameters such as C-reactive protein (p < 0.01) and seromucoids (p < 0.001). Circulating D dimer was age-related in all groups (p < 0.05). Fibrin degradation, as reflected by plasma D dimer, is detected in patients with ulcerative colitis exhibiting a marked acute phase response.

Adult↗
PubMed1993

Triple ventricular parasystole.

This presentation reflects the analysis of an electrocardiographic recording obtained from a patient with hypertensive heart disease. In the initial section of the tracing, fixed coupled monomorphic ectopic ventricular beats occurred in regular trigeminal rhythm. The pattern changed following an atrial extrasystole and several ventricular ectopic beats of various configuration occurred, often in sequence. Analysis demonstrated the presence of three independent parasystolic rhythms, two of which manifested with the character of intermittency, namely they were occasionally reset by extraneous impulses. The interplay of the sinus pacemaker with three parasystolic foci resulted in a very complex arrhythmic pattern. In some periods, however, two out of three ectopic rhythms were inapparent, and the third one manifested with fixed coupled complexes, so that a regular extrasystolic trigeminy ensued, and parasystole was not recognizable.

Aged↗
PubMed1993

Lansoprazole and Helicobacter pylori infection.

Helicobacter pylori-associated gastritis is present in virtually all patients with duodenal ulcer (DU). Eradication of H pylori is associated with a highly significant decline in the recurrence rates of DU, indicating that treatments aimed at eradicating H pylori are mandatory in these patients. The novel proton pump inhibitor lansoprazole exhibits a potent antiulcer effect and, in vitro, a direct antibacterial effect against H pylori. Conflicting data have been reported on the question of whether lansoprazole is bactericidal against H pylori in vivo when administered alone. The aim of this double-blind trial was to address this issue further by comparing the effects of two different 4-week regimens (lansoprazole alone or in combination with amoxicillin) on H pylori infection in patients with DU. Patients were assessed before and after the 4-week treatment and 3 months after stopping the study medication. The ulcer healing rates at 4 weeks were similar for the two treatments while there was a trend for higher recurrence rates at 4 months in patients receiving lansoprazole alone. The frequency of high-grade H pylori infection was significantly lower in the lansoprazole and amoxicillin group both at 4 weeks (84% clearing) and 4 months. After 4 weeks of treatment there were no patients with residual H pylori-positive active antral gastritis in the lansoprazole and amoxicillin group compared with 25% in the lansoprazole alone group. Neither treatment significantly affected the IgG antibody response to H pylori either at the circulatory or the mucosal level. In contrast, the mucosal H pylori-specific IgA response was significantly enhanced after 4 weeks and more markedly after treatment with lansoprazole.(ABSTRACT TRUNCATED AT 250 WORDS)

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1992

Irregular ventricular tachycardia: a possible manifestation of longitudinal dissociation within the reentry pathway.

Sustained monomorphic ventricular tachycardia is usually regular; that is, it is associated with constant R-R intervals. In several cases, however, the cycles of ventricular tachycardia are more or less variable. Fifty-four cases of sustained monomorphic ventricular tachycardia were evaluated in order to assess whether tachycardia was regular. Nine cases were defined as irregular (i.e., the R-R cycles varied by more than 40 msec throughout a 1-minute recording). In five cases tachycardia was "regularly irregular," since the R-R cycles could be divided into two separate groups: the group of long cycles and that of short cycles. In these cases the variability manifested according to a defined and constant pattern: bigeminal pattern (alternation of short and long cycles), trigeminal pattern (two short cycles followed by a long cycle), and so on. The regular variability of tachycardia cycle length suggests one of the following possibilities. (1) There are two alternative circuits (a short circuit and a long circuit) that share the same exit pathway. Whenever the reciprocating impulse runs through the short circuit, the R-R cycle is short; but if a block in the short circuit occurs, the impulse runs through the long circuit, resulting in a long R-R cycle. (2) There is a longitudinal dissociation within the reentry circuit; two separate pathways with different inherent conduction velocities are present. When the impulse runs through the fast pathway, the R-R cycle is short; whereas when a block in the fast pathway occurs, the impulse traverses the slow pathway, resulting in a long R-R cycle.

Electrocardiography↗