Protective effect of urate oxidase on uric acid induced-monocyte apoptosis

Uremic patients have a higher risk of infection and malignancy than normal subjects. Previous studies have deomonstrated that monocytes isolated from uremic patients display an increased apoptosis rate compared to normal subjects; furthermore uremic plasma can increase apoptosis rates on U937, a human monocytic cell line. In several pathological conditions, precipitation of uric acid crystals can lead to renal insufficiency or acute renal failure by different mechanisms. In recent studies uric acid has been shown to induce inflammatory response from monocytes and it has been suggested to be involved in cell dysfunction. Rasburicase is a new recombinant urate oxidase developed to prevent and treat hyperuricaemia in patients with cancer or renal failure; it degrades uric acid to allantoin, a less toxic and more soluble product. In the present study, we aimed at determining whether uric acid may be a factor affecting U937 apoptosis, and whether urate oxidase may reduces or even prevent uric acid induced cell apoptosis. Hoechst staining and internucleosome ledder fragmentation of DNA showed that uric acid increased the percentage of apoptotic cells comparing to the control and that when the U937 cells were incubated with uric acid and urate oxidase the percentage of apoptosis significantly decreased (from 43+/-7% to 19+/- 3%, p<0.05). Also, the activity of caspase-8 and caspase-3 showed the same trend (caspase 3: from 2.7+/-0.53 to 1.6+/-0.42; caspase-8: from 2.2+/-0.43 to 1.3+/-0.57). A reduction of intracellular reduced glutathione (GSH) concentration was found in uric acid treated cells while the addition of urate oxidase in the uric acid incubated cells decreased the GSH extrusion. The concentration of TNF-alpha was increased in the sample incubated with uric acid comparing to the control. Uric acid is an inducer of apoptosis on U937 cell line, and therefore it may be a component of the mosaic of uremic toxins both in acute and chronic renal disease. We can hypothesize that uric acid might be directly involved in the apoptotic process trough the activation of both death receptor and mitochondrial-mediated pathways. We have, also, demonstrated that urate oxidase is able to prevent at least in part, the effect of uric acid on U937 apoptosis. This effect might be a result of different mechanisms of action.

Rapid detection of Paenibacillus larvae from honey and hive samples with a novel nested PCR protocol

The bacterial pathogen Paenibacillus larvae is the causative agent of American foulbrood disease in honeybees (Apis mellifera). A touchdown nested PCR protocol was developed to detect the presence of P. larvae spores directly in honey and hive samples. This approach allows early discovery of the bacteria even at concentrations below pathogenic levels, opening the door to new prophylactic approaches against American foulbrood and real-time epidemiological studies.

Influence of Helicobacter pylori infection on severity of oesophagitis and response to therapy in the elderly

BACKGROUND

The prevalence both of Helicobacter pylori infection and oesophagitis is higher in the elderly, than in adult and young populations. However the relationship between Helicobacter pylori infection and the clinical behaviour of oesophagitis has not yet been clarified.

AIM

To evaluate the influence of Helicobacter pylori infection on the severity and clinical outcome after treatment of oesophagitis in elderly patients.

METHODS

A total of 271 elderly patients (134 male, 137 female, mean age = 79.2 years, range 65-96) with grade 1 to 3 oesophagitis were studied. At baseline, the patients were divided into 3 groups according to Helicobacter pylori infection: Group 1 = 88 Helicobacter pylori-negative patients; Group 2 = 59 Helicobacter pylori-positive patients and Group 3 = 124 Helicobacter pylori-positive patients who underwent a one-week proton pump inhibitor-based triple therapy for the eradication of Helicobacter pylori infection. All patients were treated with proton pump inhibitors for two months; patients in Group 3 were also treated for one week with proton pump inhibitors plus two antibiotics. After two months, endoscopy and histology were repeated.

RESULTS

At baseline, 32.5% of patients were Helicobacter pylori-negative and 67.5% were Helicobacter pylori-positive. No baseline differences in severity of oesophagitis were found between Helicobacter pylori negative and positive patients. After proton pump inhibitor therapy, the complete resolution of oesophagitis was observed in 80.7% of Group 1, 76.3% of Group 2 and 75.8% of Group 3 (p=ns). Dividing patients also according to the severity of oesophagitis, no difference in healing rates between the three Groups were observed.

CONCLUSIONS

In this elderly population, Helicobacter pylori infection did not influence the severity of oesophagitis at baseline or the response to short-term treatment with proton pump inhibitors. Furthermore, Helicobacter pylori eradication therapy did not influence the healing rate of oesophagitis.

Detection of Chlamydophila pneumoniae DNA in peripheral blood mononuclear cells of blood donors in the north-east of Italy

Recent studies have implicated Chlamydia pneumoniae (now Chlamydophila pneumoniae) in the pathogenesis of atherosclerosis and demonstrated its presence within human peripheral blood mononuclear cells (PBMCs). In this study the presence of C. pneumoniae DNA was assessed, using nested PCR, in PBMCs from 169 active blood donors as a function of age, of specific antibodies and C-reactive protein. The results obtained demonstrated a high degree of global positivity (46.15%), which was higher in females (52%) than in males (43.7%). Seroepidemiological studies showed a high percentage of positivity both in subjects positive by PCR (65.91%) and negative by PCR (71.74%). The clinical implication of such finding are under study.

Epidemiological analysis of vancomycin-resistant enterococci in a large tertiary-care hospital in Northern Italy

The epidemiology of vancomycin-resistant enterococci (VRE) was studied in a large tertiary-care hospital in northern Italy from February 1993 to December 1999. Sixteen cases of bacteraemic and 17 cases of nonbacteraemic active infections caused by VRE were recorded. Fifteen of the bacteraemic and four of the nonbacteraemic infections occurred in patients in the haematology department, while the remainder were registered in other departments of the same hospital. Active surveillance for the presence of VRE in stools led to identification of 51 noninfected carriers over the 1994-1999 period; of these, 32 were haematology patients and the remainder were patients admitted to other departments. All VRE isolates carried the vanA gene. Forty-one Enterococcus faecium isolates and eight Enterococcus faecalis isolates collected in the 1993-1996 period were typed by pulsed-field gel electrophoresis. Twenty-nine isolates of Enterococcus faecium shared either indistinguishable or strictly or possibly related patterns. Of these, 26 were isolated from patients in the haematology department. This is believed to be the first study on the epidemiology of VRE carried out in a large hospital in Italy over a period of several consecutive years. It reports an increase in VRE due to the epidemic spread of genetically related strains and sporadic infections or colonisation by unrelated VRE. It also documents the success of surveillance and of the measures adopted for preventing the spread of VRE in patients at risk.

Demonstration of Chlamydia pneumoniae in atherosclerotic arteries from various vascular regions

Chlamydia pneumoniae (CP) has been reported to be a pathogenic agent in the mechanism leading to atherosclerosis. The majority of available data is focused mainly on coronary artery disease whereas the distribution of CP in different areas, associated with atherosclerotic disorders, has not been completely clarified. In this study we investigated the presence of CP in atheromasic plaques from five different vascular areas (basilary artery, coronary artery, thoracic aorta, abdominal aorta, renal arteries) using nested polymerase chain reaction (PCR) and immunohistochemical staining (IHC), in order to establish the putative association of CP with atherosclerotic disease. The same atheromasic plaques were also tested for the presence of Helicobacter pylori (HP) and cytomegalovirus (CMV), other putative agents of atherosclerosis, using a nested PCR technique. Our data indicate that the presence of CP can be demonstrated in 100% of patients tested, considering globally the five areas of analysis. On the other hand the presence of HP has been demonstrated in four out of 18 patients (22.2%), and CMV only in three out of 18 (16.6%). Our results strongly suggest an association between CP and atherosclerosis and highlight the need for the detection of CP in multiple vascular areas of the same patient.

Cure of Helicobacter pylori infection in elderly patients: comparison of low versus high doses of clarithromycin in combination with amoxicillin and pantoprazole

BACKGROUND

Advancing age may influence clarithromycin's pharmacokinetics. No studies have yet compared the effects of different dosages of clarithromycin in combination with a proton pump inhibitor and amoxicillin in elderly patients.

AIM

To compare the efficacy and tolerability of clarithromycin 250 mg vs. clarithromycin 500 mg twice daily (b.d.) in combination with pantoprazole and amoxicillin in elderly patients.

METHODS

One hundred and fifty-four elderly patients with H. pylori-associated ulcer disease or chronic gastritis were consecutively randomized to receive pantoprazole 40 mg daily plus amoxicillin 1 g, and either clarithromycin 250 mg b.d. (PAC 250) or clarithromycin 500 mg b.d. (PAC 500). Two months after therapy, endoscopy and gastric biopsies were repeated.

RESULTS

The cure rates of H. pylori infection in the PAC 250 and PAC 500 groups were, respectively, 83% and 79% (ITT analysis) and 94% and 88% (PP analysis) (P=N.S.). Significant decreases in chronic gastritis activity both in the body (P < 0.00001) and the antrum (P < 0.0001) of the stomach were found in H. pylori-cured patients, independently of clarithromycin dosage. Four patients in PAC 250 (5%) and seven in PAC 500 (9%) reported adverse events (P=N.S.). One patient in PAC 250 (25%) and three in PAC 500 (43%) discontinued the study because of these drug-related side-effects (P=N.S.).

CONCLUSIONS

In elderly patients, 1-week triple therapy with a proton pump inhibitor, amoxicillin and clarithromycin is a highly effective and well tolerated anti-H. pylori treatment. With this combination, clarithromycin at the lower dose of 250 mg b.d. achieved excel- lent cure rates and minimized adverse events and costs.

Prevalence of Helicobacter pylori resistance to antibiotics in Northeast Italy: a multicentre study. GISU. Interdisciplinary Group for the Study of Ulcer

AIMS

To evaluate prevalence of primary Helicobacter pylori antibiotic resistances in Northeast Italy and to identify risk factors associated with this resistance.

MATERIALS AND METHODS

A total of 248 patients undergoing upper gastrointestinal endoscopy were enrolled from 19 Endoscopy Units over a 6-month period. From each patient, 4 gastric biopsies were taken for histology and 2 were sent to the Central Referral Microbiological Laboratory for culture and determination of antibiotic activity against Helicobacter pylori by means of E-test. Strains were considered resistant when minimum inhibitory concentration was >8 microg/ml for metronidazole and >1 microg/ml for clarithromycin. No cut-off value was predefined for amoxycillin.

RESULTS

Culture of Helicobacter pylori was successfully performed in 167 patients. Primary resistance to metronidazole, clarithromycin or amoxycillin was 14.9%, 1.8% and 0%, respectively Patients infected with Helicobacter pylori strains resistant to antibiotics were more frequently females than males (70.3% vs 41.4%), had a significantly lower coffee intake (66.6% vs 86.6%) and lower body mass index (23.7+/-2.6 vs 25.3+/-3.6) than patients with susceptible Helicobacter pylori strains. Age, smoking, alcohol use, family history of Helicobacter pylori infection, concomitant diseases and treatments, endoscopic diagnoses, Helicobacter pylori density and histological activity of chronic gastritis were not associated with antibiotic resistance. Multivariate analysis confirmed that female gender (odds ratio = 2.74, 95% confidence interval = 1.03-7.27) was the only significant risk factor associated with antibiotic resistance.

CONCLUSIONS

In this population, primary Helicobacter pylori resistance to metronidazole was higher than resistance to clarithromycin, and female gender was significantly associated with this resistance. The low prevalence of resistance to metronidazole, clarithromycin and amoxycillin identified in this geographical area suggests that proton pump inhibitor-based triple regimens including these antibiotics may still be used as first line therapies against Helicobacter pylori infection.

Incidence of secondary Helicobacter pylori resistance to antibiotics in treatment failures after 1-week proton pump inhibitor-based triple therapies: a prospective study

BACKGROUND

Antibiotic-resistant Helicobacter pylori strains are becoming increasingly prevalent, although it is not clear to what extent the new resistant organisms will spread.

AIM

To evaluate the incidence of secondary Helicobacter pylori resistance to metronidazole, clarithromycin and/or amoxycillin after one-week proton pump inhibitor based triple therapy failure in patients who were, before therapy infected with Helicobacter pylori strains susceptible to these antibiotics.

PATIENTS AND METHODS

Enrolled in the study were 97 consecutive Helicobacter pylori-positive subjects infected by Helicobacter pylori strains susceptible to metronidazole, clarithromycin and amoxycillin. Activity of tested antibiotics was determined by means of the E-test. Patients were treated for seven days with a proton pump inhibitor, omeprazole 20 mg twice daily or pantoprazole 40 mg once daily, plus clarithromycin 250 mg twice daily and metronidazole 250 mg four times daily; or with a proton pump inhibitor plus amoxycillin 1 g twice daily and clarithromycin 500 mg twice daily. Two months after completion of therapy, endoscopy and gastric biopsies for histology, rapid urease test and culture were repeated.

RESULTS

Four patients were dropped from the study Overall Helicobacter pylori cure rates expressed as both intention-to-treat and per-protocol analyses, were, respectively 80% (40/50) and 81.6% (40/49) with proton pump inhibitor, clarithromycin and metronidazole and 76.6% (36/47) and 81.8% (36/44) with proton pump inhibitor amoxycillin and clarithromycin. No significant differences were observed between the two treatments. Subjects in whom treatment failed were significantly younger and had less active ulcer than cured patients. Of treatment failures, 70.6% (12 out of 17 subjects) de veloped a secondary resistance to metronidazole (35.33% and/or clarithromycin (64.7%). Secondary antibiotic resistance occurred in 77. 8% of treatment failures treated with proton pump inhibitor, clarithromycin and metronidazole and in 62.5% of those treated with proton pump inhibitor, amoxycillin and clarithromycin. Considering all patients treated, the overall incidence of secondary metronidazole and/or clarithromycin resistance after therapy was reported in 12.9% of subjects (12 out of 93 treated patients).

CONCLUSIONS

Secondary Helicobacter pylori resistances to metronidazole and/or clarithromycin occurred in large percentages in patients with treatment failure after the one-week proton pump inhibitor-based triple therapies, proton pump inhibitor, clarithromycin and metronidazole and proton pump inhibitor, amoxycillin and clarithromycin. It is likely that new antibiotics or treatment strategies will be needed in the near future to successfully treat Helicobacter pylori infection.

Role of antigenemia assay in the early diagnosis and treatment of CMV infection in renal transplant patients

AIM

CMV antigenemia by direct pp65 antigen detection and quantification was monitored on a weekly basis during the first 3 months after kidney transplantation.

SUBJECTS AND METHODS

Preemptive therapy with ganciclovir was started according to the following criteria: any positive antigemia in CMV-NEG subjects, a single determination > or = 30 cell or a two fold increase of positive cells in two consecutive specimens in CMV-POS and continued until pp65 was cleared. Overall, 109 patients were monitored.

RESULTS

Among the 24 CMV-NEG patients, 13 (54%) developed a pp65 positive assay without symptoms and were treated. Ten patients remained CMV-infection free and one patient developed late onset (7 months) CMV disease (hepatitis). Among the 85 POS patients 15 (17%) developed a pp65 positive assay and were treated. Two of them developed CMV disease within 7 days of the onset of positive antigenemia and 13 were asymptomatic. The other 70 patients remained CMV-infection free. The interval between transplant and the onset of CMV infection was 39 +/- 13 days in the CMV-NEG group and 64 +/- 20 days in the CMV-POS group (p < 0.001). The peak antigenemia level was 193 +/- 175 cells in the CMV-NEG group and 55+/- 78 cells in the CMV-POS group (p < 0.001). The duration of treatment did not differ in the two groups (22 +/- 7days). A second course of therapy, due to a relapse of asymptomatic infection was performed in 11/13 (85%) treated CMV-NEG patients and in 2/15 (13%) treated CMV-POS patients.

CONCLUSIONS

Among the total 28 treated patients, we observed only 6 episodes of mild creatinine increase and 9 episodes of mild neutropenia. In the overall population, we observed 8 systemic infections not related to CMV.

Noninvasive diagnosis of Helicobacter pylori infection in older subjects: comparison of the 13C-urea breath test with serology

BACKGROUND

The potential influence of cognitive status, physical activities, comorbidity and cotreatments on the feasibility and diagnostic accuracy of two noninvasive diagnostic tests for Helicobacter pylori (Hp) infection, i.e., the 13C-urea breath test (13C-UBT) and serology (immunoglobulin G [IgG] anti-Hp antibodies), in older subjects is not known.

METHOD

The study involved 100 consecutive symptomatic elderly subjects (mean age, 78.3 years; range, 65-96 years), who had undergone an upper gastrointestinal endoscopy. Patients were considered Hp positive if at least two of the three invasive methods, i.e. histology, culture, and/or the rapid urease test were positive for Hp infection. Patients were considered Hp negative if all three invasive methods were negative. The 13C-UBT was performed according to the European standard method and the assaying of IgG anti-Hp antibodies by enzyme-linked immunosorbent assay. Cognitive status and functional activities were determined by the Mini-Mental State Examination (MMSE), the activities of daily living (ADLs) and instrumental ADLs (IADLs).

RESULTS

According to invasive methods, 49 patients were Hp positive and 47 were Hp negative (4 subjects were excluded from the study). Hp-positive patients demonstrated a significantly higher prevalence of peptic ulcers (p =.02) and activity of chronic gastritis (p<.0001) than Hp-negative subjects. The 13C-UBT demonstrated a sensitivity of 100%, a specificity of 95.7%, and a diagnostic accuracy of 97.9%. Serology had significantly lower sensitivity (74.4%), specificity (59%), and diagnostic accuracy (67%, p<.001) than the 13C-UBT. The feasibility and the diagnostic accuracy of the 13C-UBT were not altered by the cognitive status (MMSE) and functional activities (ADL, IADL) of the patients, their drug consumption, or the prevalence of concomitant diseases.

CONCLUSIONS

In older subjects, the 13C-UBT had a significantly higher diagnostic accuracy than serology without influence of cognitive function, disability, comorbidity and cotreatments. This method may be considered an excellent, clinically useful, noninvasive test for the diagnosis of Hp infection in older subjects.

Interferon alfa-2b alone or in combination with ketoprofen as treatment for interferon-naive chronic hepatitis C patients

BACKGROUND

Non-steroidal anti-inflammatory drugs may amplify the anti-viral effect of alpha-interferon in vitro but in vivo data are still controversial.

AIM

: To test the hypothesis that ketoprofen may increase the rate of response to alpha-interferon of chronic hepatitis C patients.

METHODS

Fifty patients with chronic hepatitis C who had never received alpha-interferon were randomly assigned to receive 3-8 MU of alpha2b-interferon, three times weekly for 6 months, alone or in association with ketoprofen at a dose of 200 mg/day five times weekly. The virological response to treatment (undetectable HCV RNA in serum) was evaluated after 3 months and at the end of treatment, and 6 and 12 months after therapy withdrawal.

RESULTS

One patient under combination therapy stopped the ketoprofen for persisting epigastric pain. Complete response under treatment was observed in 15 out of 24 (62.5%) patients receiving alpha2b-interferon alone and in 14 out of 26 (53.8%) patients under combination therapy (P=N.S.). One year after the end of treatment, a sustained response was seen in 4 out of 24 (16.2%) patients treated with alpha2b-interferon and in 5 out of 26 (19.2%) patients having received the combination (P=N.S.).

CONCLUSION

Administration of ketoprofen does not increase either the primary or the sustained response to alpha2b-interferon therapy of interferon-naive chronic hepatitis C patients.

Efficacy of 7 day lansoprazole-based triple therapy for Helicobacter pylori infection in elderly patients

BACKGROUND

The prevalence of Helicobacter pylori increases with age. However, data regarding the effects of anti-H. pylori treatments in the elderly are very scarce.

METHODS

To evaluate the effect of three lansoprazole-based, 7 day, triple-therapy regimens on H. pylori eradication rates, symptomatology, chronic gastritis activity and serological markers of H. pylori infection in elderly subjects, we studied 150 symptomatic patients over 60 years of age with H. pylori-positive duodenal ulcer (DU, n = 34), gastric ulcer (GU, n= 19) or chronic gastritis (CG, n = 97). Patients were consecutively treated with one of the following regimens: (A) lansoprazole (LNS) 30 mg b.i.d. + clarithromycin (CLR) 250 mg b.i.d. + metronidazole (MTR) 250 mg q.i.d.; (B) LNS 30mg b.i.d. + amoxycillin (AMOX) 1 g b.i.d. + MTR 250 mg q.i.d.; and (C) LNS 30 mg b.i.d. + CLR 250 mg b.i.d. + AMOX 1 g b.i.d.

RESULTS

Two months after therapy, the eradication rates of the three treatments, expressed using both intention-to-treat and per-protocol analyses were, respectively; group A, 86 and 91.5%; group B, 80 and 87%; group C, 82 and 89.1%. After therapy, a significant reduction in epigastric pain (P<0.001), heartburn (P=0.02), dyspepsia (P<0.001) and vomiting (P< 0.005) was observed independently of the success of H. pylori eradication. A significantly higher percentage of asymptomatic patients were in the GU-DU group than in CG group (87.7 vs 70.0%, P= 0.032). After therapy, 33 subjects still suffered from symptoms. Persistence of symptoms was significantly associated with an endoscopic diagnosis of oesophagitis and not with H. pylori infection. Patients cured of H. pylori infection showed a significant decrease in the histological activity of both antral and body gastritis (P< 0.0001), a significant drop in immunoglobulin (Ig) G anti-H. pylori antibodies (P< 0.0001) and pepsinogen (PG) C (P<0.0001) and an increase in the PGA/PGC ratio (P<0.0001).

CONCLUSIONS

The 7 day, lansoprazole-based triple therapy was well tolerated and highly effective in the cure of H. pylori infection, the reduction of symptoms, chronic gastritis activity and serum levels of IgG anti-H. pylori antibodies and PGC. Persistence of symptoms after therapy was significantly higher in CG than GU and DU patients and was significantly associated with oesophagitis.

The effect of antibiotic resistance on the outcome of three 1-week triple therapies against Helicobacter pylori

BACKGROUND

Resistance of Helicobacter pylori to antibiotics may be a major reason for treatment failure.

AIM

To evaluate the effect of primary H. pylori resistance to antibiotics on the cure rates of three anti-H. pylori 1-week triple therapies.

METHODS

One hundred and sixteen consecutive patients diagnosed H. pylori-positive by gastric histology, rapid urease test and culture were enrolled. Activity of tested antibiotics was determined by means of the E-test. Patients were treated for 7 days with: (i) pantoprazole 40 mg o.d. plus amoxycillin 1 g b.d. and metronidazole 250 mg q.d.s. (PAM); (ii) pantoprazole 40 mg o.d. plus clarithromycin 250 mg b.d. and metronidazole 250 mg q.d.s. (PCM); or (iii) pantoprazole 40 mg o.d. plus amoxycillin 1 g b.d. and clarithromycin 250 mg b.d. (PAC). Two months after completion of therapy, endoscopy and gastric biopsies were repeated.

RESULTS

Primary resistance rates to metronidazole, clarithromycin and amoxycillin were 17.2, 6.9 and 0%, respectively. Overall H. pylori cure rates expressed as intention-to-treat and per protocol analyses were, respectively, 79% and 86% with PAM, 82% and 89% with PCM, and 85% and 85% with PAC. Significantly lower cure rates were observed in metronidazole-resistant patients treated with PAM (56% vs. 96%, P = 0.01) or PCM (50% vs. 97%, P = 0.01). A trend towards lower H. pylori cure rates was observed in clarithromycin-resistant patients treated with PCM (67% vs. 91%, P = 0.74) or PAC (50% vs. 87%, P = 0.68).

CONCLUSION

Primary resistance to metronidazole influences the H. pylori cure rate of anti-H. pylori proton pump inhibitor-based triple therapies which include this antibiotic. A similar trend exists for primary clarithromycin resistance.

Cytotoxin-associated gene A-positive Helicobacter pylori infection in the elderly. Association with gastric atrophy and intestinal metaplasia

To evaluate if the infection with strains of cytotoxin-associated gene A (CagA)-positive Helicobacter pylori is associated with either peptic ulcer and gastric atrophy or intestinal metaplasia in the elderly, we studied 71 H. pylori-positive patients older than 62 years old (34 men, 37 women; mean age, 77.5 years; range, 62-89 years) affected with gastric ulcer (GU) (n = 10), duodenal ulcer (DU) n = 22), or chronic gastritis (CG) (n = 39). H. pylori infection was documented by means of gastric histology, rapid urease test, and polymerase chain reaction (PCR) assay performed on gastric biopsies using two sets of primers: one for the ureC gene specific for H. pylori, and the second specific for the CagA gene. H. pylori-CagA positivity was significantly more common in patients with GU (9 of 10, 90%) than with DU (11 of 22, 50%; p < 0.05) or CG (17 of 39, 43.5%; p = 0.01). Gastric atrophy and intestinal metaplasia were significantly more common in CagA-positive patients than in CagA-negative patients (gastric atrophy: 40.54% vs 11.76, p = 0.007; intestinal metaplasia: 40.54% vs 14.70%, p = 0.01). No difference in prevalence of gastric atrophy and intestinal metaplasia was found in patients divided according to pathology (GU, DU, or CG). Logistic regression demonstrated that gastric atrophy and intestinal metaplasia were independent factors significantly associated with CagA-positivity (gastric atrophy: odds ratio = 4.53, 95% confidence interval 1.25-16.4; intestinal metaplasia: odds ratio = 3.44, 95% confidence interval 1.01-11.7). Our findings help to confirm the hypothesis that an infection with CagA-positive H. pylori strains may be catalytic in inducing gastric changes which can evolve into malignancies.

Spontaneous resolution of p58/EB6 antigen restricted NK-type lymphoproliferative disease of granular lymphocytes: role of Epstein Barr virus infection

We describe a patient with a CD3- lymphoproliferative disease of granular lymphocytes (LDGL) characterized by proliferation of CD3-CD16+ GL, restricted to the expression of p58/EB6 antigen and lacking the p58/GL183 antigen. Using PCR analysis we demonstrated the presence of EBV DNA in the peripheral blood mononuclear cells and purified CD16+ GL from the patient; a monoclonal episomic configuration of the virus could not be demonstrated with Southern blot analysis. The presence of EBV DNA was also detected by PCR in the serum; this finding was associated with a serological pattern consistent with a previous, already seroconverted, EBV infection. During a 4-year follow-up the lymphocytosis spontaneously disappeared; interestingly, in terms of the p58 antigen expression, we provided evidence of the reconstitution of a normal pattern of circulating NK subsets (i.e. p58/EB6+ p58/GL183-, p58/EB6+ p58/GL183+, p58/EB6- p58/GL183-, p58/EB6-p58/GL183+). At the time of resolution of lymphocytosis, EBV-PCR analysis still demonstrated the persistence of EBV DNA in peripheral blood mononuclear cells, but not in the patient's serum. By indicating that inciting agents (in this case EBV) are involved in inducing the GL proliferation, our data contribute insights into the pathogenetic mechanisms accounting for in vivo GL accumulation in LDGL. It appears that a second, still unknown, event is required to determine the neoplastic transformation.

Investigation of a Q-fever outbreak in northern Italy

OBJECTIVES

A study was conducted to evaluate the extent of a Q-fever epidemic through active case finding in the area of Vicenza (north-eastern Italy), and to identify risk factors for Q-fever in this outbreak.

METHODS

1) Descriptive epidemiology; 2) Seroepidemiological survey; 3) Case-control study. 1) Epidemic curve and maps with the location of cases. Identification of the road followed by the flocks of sheep. 2) Cross-sectional study on humans and flocks of sheep tested for anti-Coxiella burnetii antibodies. 3) Cases were defined by the presence of fever > 38 degrees C plus serological confirmation. Controls were 94 apparently healthy individuals attending outpatient facilities for control visits or certification, group-matched by geographical area, age and gender. A standardized questionnaire was administered by trained interviewers. Odds ratio and 95% confidence intervals (CI) were used to evaluate risk factors for Q-fever.

RESULTS

A total 58 cases were identified in a 5-month period. Male to female ratio was 2.8:1; mean age was 42 years (range: 20-65 years). Twenty-eight patients (48%) were hospitalized. Fever was accompanied by asthenia (81%), headache (76%), chills (72%), and myalgia and arthralgia (53%); cough was present in 47% of patients. Rx abnormalities were found in 81% of the patients undergoing chest X-ray. Among 111 apparently healthy family members who underwent serological testing, four (3.6%) had antibodies to Coxiella burnetii. Three flocks which passed through the outbreak area between late May and early June were shown to be infected, with prevalence of antibodies ranging between 45 and 53%. The case-control study showed a significant association with exposure to flocks of sheep (Odds ratio = 6.1; 95% CI 2.5, 16.3). Other potential risk factors were not more commonly reported by cases with respect to controls.

CONCLUSIONS

Indirect exposure to flocks of sheep was a determinant of this outbreak of Q-fever. This finding suggests that transmission occurred through inhalation of contaminated airborne particles. The importance of control measures should be stressed in areas traversed by flocks of sheep.

Diagnosis of HIV infection from bloodstains by PCR. A further marker for identification

The forensic usefulness of the detection of HIV infection in bloodstains is linked to the increasing spread of HIV infection and the consequent rise in the number of forensic cases involving HIV-positive subjects. This study was designed to detect HIV infection in bloodstains of various ages obtained from HIV-positive patients treated with zidovudine (3'-azido-3'-deoxythymidine, AZT) using PCR methods. Of the 3 kinds of extraction and amplification methods checked, only a nested PCR method for the amplification of a sequence located in the HIV Reverse Transcriptase (RT) region was successful. This method, involving 2 amplification steps (1: fragment of 768 bp; 2: codons 41-67-70-215-219), encompasses the mutations commonly observed during AZT therapy and overcomes the limitations inherent in serological testing. The discriminatory power of the method can detect specific mutation patterns in the RT gene linked to drug resistance and compares the specific pattern of the blood-stain with fresh blood or other specimens from the subject in question.

Polymerase chain reaction amplification and restriction enzyme typing as an accurate and simple way to detect and identify human papillomaviruses

A simple and economic method for the detection and identification of human papillomaviruses (HPV) is described. The method has been developed with cloned HPV DNA and DNA from clinical samples. Genomic fragments were obtained from several different HPV types, including the ones most frequently encountered in the genital tract by polymerase chain reaction (PCR) amplification directed by degenerate general primers. The amplification fragments were identified by a form of miniature fingerprinting, with a set of restriction enzymes that gave a unique digestion pattern for each HPV type. Different strategies are proposed, based on PCR and restriction analysis, and this approach to identification was compared with more classic methods such as Southern hybridisation.

Relevance of DNA binding to the mechanism of anti-herpesvirus activity of benzhydrazone

Benzhydrazone (1H-benz(f)indene-1,3(2H)-dione bis (amidino-hydrazone) (BH) is a synthetic compound with selective anti-herpesvirus activity. Its selectivity seems to stem from the inhibition of viral protein glycosylation and several hypotheses have been formulated to explain such an effect. Data presented here demonstrate that DNA binding is a prominent feature of BH. Interaction is taking place with a relatively high affinity constant and is more efficient for GC-rich viral sequences. Experiments with the cloned DNA fragments from a BH-resistant virus strain indicate that BH-DNA complex formation is drastically reduced as compared to BH-sensitive virus. The occurrence of the resistant phenotype in HEp-2 cells but not in Vero cells could be explained by differences in BH cytotoxicity. Changes in drug uptake and accumulation by cells following infection, in addition to GC preference, may also account for the degree of antiviral selectivity shown by BH.

Water-soluble polysaccharide-anthracycline conjugates: biological activity

The anticancer agents doxorubicin and daunorubicin were covalently linked to the water-soluble anionic polysaccharides hyaluronic acid and carboxy-methylcellulose. The drug-polymer conjugates are in principle prevented from entering cells, can efficiently bind to cell surfaces and allow precise dose-response determinations. In addition, they are not able to bind DNA because of their negative charge. Cell growth and DNA synthesis inhibition studies indicated decreased cell toxicity for the polymer conjugates. The mol. wt of the carrier was shown to affect the biological activity of the anthracycline to a moderate extent. Partial drug incorporation into cells was observed as a function of time, probably due to endocytosis phenomena followed by biochemical cleavage of the conjugate. The conclusion was drawn that membrane binding appears to contribute to total toxicity only to a minor extent.