Leishmania donovani adenylate kinase 2a prevents ATP-mediated cell cytolysis in macrophages.

In Leishmania spp. ATP utilizing enzymes serves as a key role in preserving integrity of host cells for survival of parasite. Earlier reports suggested that Adenylate kinase (AK) a phosphotransferase enzyme released by Leishmania donovani secretome, involved in modulating levels of NTPs. In the present study, we cloned, expressed and characterized recombinant putative AK. Based on a sequence and phylogeny analysis, we identified the prominent features of the seven AK isoforms of Leishmania donovani and assigned our putative AK as LdAK2a. The Km value of LdAK2a for ATP and AMP substrate were 204 µM and 184 µM, respectively and Vmax was calculated as 1.6 µmol min-1 mg-1 protein. Ap5A, a known inhibitor of AK inhibited LdAK2a with estimated Ki values of 280 nM and 230 nM for ATP and AMP respectively. CD spectral studies were carried out to estimate its structural stability. Recombinant LdAK2a was found to prevent ATP mediated cell cytolysis of Raw 264.7 macrophages in vitro, which was determined by LDH assay and MMP assay. This is the first report which validates that Leishmanial AK2a can prevent ATP mediated cytolysis of macrophage cells and thereby probably play a role in preserving integrity of host cells for survival of parasite.

Nanovesicular carrier-based formulation for skin cancer targeting: evaluation of cytotoxicity, intracellular uptake, and preclinical anticancer activity.

CONTEXT: Skin cancer has turned into global epidemic leading to higher incidences among cancer stricken population. OBJECTIVE: The aim of the present investigation is to evaluate the anticancer potential and intracellular uptake of a novel nanovesicular formulation of 5-FU. MATERIALS AND METHODS: Detailed intracellular uptake study in conjunction with estimation of intracellular reactive oxygen species was done using skin melanoma cell lines (A375) along with cytotoxicity studies. To further obtain the mechanistic insights into inhibition of tumor cell proliferation, cell-cycle arrest studies were conducted. The preclinical anticancer activity was carried out employing in vivo DMBA-croton oil-induced skin cancer model in mice. RESULTS AND DISCUSSION: Significant reduction in the number of papillomas was observed in skin cancer-bearing mice on treatment with nanovesicular formulation (51.4 ± 3.2%) in comparison with marketed formulation (21.3 ± 2.1%) of 5-FU. Tumor volume was found to be reduced to 46.3 ± 3.5% with prepared formulation, whereas the marketed formulation-treated group showed the reduction of 18.6 ± 1.8% in comparison with the control (untreated) group. CONCLUSION: The results of present study demonstrated that nanovesicular formulation of 5-FU possessed the enhanced anticancer activity which could be attributed to better intracellular uptake, cellular retention, and sustained release of drug.

Resveratrol - an ingredient of red wine abrogates the reproductive capacity in male mice.

Resveratrol has been considered as an antioxidant in biological system. However, its role in male reproductive biology has not yet been evaluated in much detail. Present study analysed its effect on male reproductive function in adult mouse, after its intraperitoneal administration (2, 8 and 20 mg kg b.wt.(-1) per day) for 2 weeks. The generation of reactive oxygen species and lipid peroxidation in testis increased with concomitant decrease in sperm count and motility following resveratrol treatment as compared with the control group. Resveratrol had a negative impact on the activities of antioxidant enzymes namely catalase and superoxide dismutase and on the level of reduced glutathione. Increase in the level of oxidised glutathione by resveratrol lead to a shift in the redox ratio. Additionally, a significant loss of Leydig cells and alterations in testicular histomorphology (excessive vacuolisation and shrinkage of seminiferous tubules) was also observed. In conclusion, the deleterious effects of resveratrol on germ cells could be attributed to its pro-oxidant ability leading to testicular tissue damage.

Quercetin impairs the reproductive potential of male mice.

Oxidative stress is a leading cause of male infertility. To combat this, germ cells and spermatozoa are endowed with various enzymes, vitamins and proteins. Certain other components of food, including bioflavonoids, also provide protection against free radicals. This study analysed the effect of quercetin, a bioflavonoid, on male reproductive function in adult mice, after intraperitoneal treatment with varying concentrations of quercetin (2, 8 and 20 mg kg(-1) b.wt.) for 2 weeks. Quercetin increased the generation of reactive oxygen species and lipid peroxidation in the testis with concomitant decrease in sperm count and motility in a dose-dependent manner. Activities of antioxidant enzymes catalase, superoxide dismutase and levels of reduced glutathione were found to be decreased in a dose-dependent manner. Also, the levels of oxidised glutathione were increased leading to a shift in redox ratio. The testicular histomorphology was also altered dose dependently. Germ cell kinetic study revealed significant loss of various germ cell populations with increasing dose of quercetin. Interestingly, there was a reduction in germinal epithelium thickness concomitant with an increase in seminiferous tubule lumen diameter. In conclusion, the deleterious effects of quercetin on germ cells could be attributed to its pro-oxidant ability that might affect the Sertoli cell functions.

Enhancement in alpha-tocopherol succinate-induced apoptosis by all-trans-retinoic acid in primary leukemic cells: role of antioxidant defense, Bax and c-myc.

We investigated the possible mechanisms of All-trans retinoic acid (ATRA)-promoted apoptosis induced by alpha-tocopherol succinate (alpha-TS) in freshly isolated leukemic cells obtained from chronic myeloid leukemic patients. alpha-TS at 50 microM concentration significantly decreased superoxide dismutase (SOD) activity and reduced glutathione (GSH) by 29% and 25%, respectively, and increased lipid peroxidation level by 33%. Though 10 microM ATRA did not affect these parameters, it further significantly enhanced alpha-TS-induced changes. Bax expression in the leukemic cells was increased by treatment with ATRA, alpha-TS, and their combination to 40%, 240%, and 320%, respectively, without any change in Bcl2 and p53 expression. C-myc was down regulated by treatment with ATRA, alpha-TS and their combination to 22%, 48.5%, and 52%, respectively. In conclusion, the data reveal that enhancement of alpha-TS-induced apoptosis by ATRA in leukemic cells was through up regulation of Bax and lipid peroxidation, and down regulation of c-myc and GSH.

Effects of green tea extract on learning, memory, behavior and acetylcholinesterase activity in young and old male rats.

OBJECTIVE: To study the effects of green tea extract administration on age-related cognition in young and old male Wistar rats. METHODS: Young and old rats were orally administered 0.5% green tea extract for a period of eight weeks and were evaluated by passive avoidance, elevated maze plus paradigm and changes in acetylcholinesterase activity. RESULTS: Treatment of young and old rats with the extract resulted in no significant difference in performance on the rota rod treadmill test/righting reflex time. Green tea extract significantly improved learning and memory in older rats, with increased retention latency to enter difference in passive avoidance test. In the elevated maze test, green tea treatment resulted in significantly more number of entries in the enclosed arm by the young and old rats. Decline in acetylcholinesterase activity was observed in the cerebrum of green tea treated old rats in comparison to the green tea treated young rats. CONCLUSION: Green tea extract administration is effective in enhancing learning and memory in aged rats, and hence, may serve useful in reversing age-related deficits.

Low dose gamma-irradiation differentially modulates antioxidant defense in liver and lungs of Balb/c mice.

PURPOSE: To evaluate the effect of low-dose (<50 cGy) whole body ?-irradiation on the antioxidant defense system in the liver and the lungs of mice at various post-irradiation intervals. MATERIALS AND METHODS: Male Balb/c mice, 5 - 6 weeks of age, were divided into irradiated and non-irradiated groups. Whole body irradiation was done with gamma-rays from a (60)Co source at doses of 10, 25 and 50 cGy (48.78 cGy/min). Lipid peroxidation and antioxidant status were measured in the liver and the lungs at 4, 12 and 24 h after irradiation. RESULTS: Lipid peroxidation increased by 1.38 and 2.0 fold in lung and liver respectively at 12 h after exposure to 25 cGy. Whole body exposure to 25 and 50 cGy significantly (p < 0.05) increased the hepatic reduced glutathione at 4 h. Reduced glutathione continued to rise until 12 h and returned to the basal level at 24 h, whereas in the lungs it remained elevated until 24 h at 10 and 25 cGy. Antioxidant enzymes activities for superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase increased by 1.22, 1.13, 1.22 and 1.11 fold respectively (p < 0.05) in the liver at 4 h after exposure to 50 cGy and remained elevated at almost the same level up to 12 h after exposure. Surprisingly these antioxidant defense enzymes remained unaltered in the lung at the above radiation doses. CONCLUSIONS: Low-dose whole body gamma-irradiation differentially modulates the antioxidant defense system in the liver and lungs of mice. The induction of endogenous glutathione, immediately after exposure to low-dose -irradiation, may be beneficial in protecting the cells from reactive oxygen species (ROS) induced oxidative stress.

Urea breath test for Helicobacter pylori detection: present status.

Helicobacter pylori (H. pylori) is the commonest bacterial pathogen found worldwide and more than half the world population aged 40 years and above is colonized with it. The infection rate is >95 % in some African countries. In 1994, the International Agency for Research on cancer classified H. pylori as a class I carcinogen in humans. It causes chronic active gastritis, duodenal and gastric ulcer and gastric malignancy, and is thought to be associated with coronary artery disease, cerebral stroke, vitamin B12 and iron-deficiency anaemia, etc. Therefore, non-invasive test-and-treatment strategies are widely recommended in primary care settings. Conventionally, H. pylori infection can be diagnosed by invasive techniques using an upper gastrointestinal endoscope for obtaining multiple biopsies from different sites of the stomach for RUT, culture, histological examination, polymerase chain reaction (PCR), etc. and by non-invasive tests such as Urea breath test (UBT), stool antigen test and blood serology. At present, 13/14C-UBT is considered the test of choice for confirmation of H. pylori infection. The UBT is based on the principle, that isotopically labelled urea ingested by an H. pylori--infected patient is rapidly hydrolysed by the microbial urease. The released 13/14CO2 is absorbed across the mucous layer to the gastric mucosa and hence, excreted via the systemic circulation in the breath which is collected and measured. The non-hydrolysed urea is excreted completely in the urine within 3-4 days. 13C-UBT being non-radioactive, 13C-UBT can be used in pregnant women and children, and a user's license is not required. There is still no standard protocol accepted and followed internationally for this test. Although the methods are almost similar, various laboratories/clinics use variable tracer doses, test meals, timings and methods for breath collection, and different cut-off values, which make formal validation studies necessary. This review describes the present status of the UBT and its application in the detection of H. pylori infection.

Effect of eradication of Helicobacter pylori on gastric antrum histology.

BACKGROUND: Helicobacter pylori is a leading cause of gastritis. Some of the histological changes revert after eradication of H. pylori. There is paucity of reports from India. AIM: To study the effect of H. pylori eradication on the histopathological changes. METHODS: Endoscopically obtained antral biopsies from 164 consecutive H. pylori positive cases of dyspepsia were analysed before and 4 weeks after completion of treatment. RESULTS: Treatment for H. pylori resulted in eradication of the organism as confirmed histologically in 123 out of 164 (76.22%) cases. Analysis of histopathological changes in pre and post treatment biopsies from the same patient revealed a significant reduction in neutrophils, eosinophils, chronic inflammatory cells, acute epithelial changes and regenerative foveolar hyperplasia (p < 0.001) There was no difference in these findings in cases where H. pylori eradication failed when compared with their pre-treatment biopsies (p > 0.05). Similarly the pre and post treatment biopsies revealed, no difference in frequency of intestinal metaplasia and gastric atrophy in cases where H. pylori was eradicated or persisted after treatment. CONCLUSION: There was significant reduction in neutrophils, eosinophils, chronic inflammatory cells, acute epithelial changes and regenerative foveolar hyperplasia, following eradication of H. pylori.

Evaluation of the predictors of choledocholithiasis: comparative analysis of clinical, biochemical, radiological, radionuclear, and intraoperative parameters.

This prospective study was performed to assess the predictive ability of the various indicators of common bile duct (CBD) calculi, individually or in combination, by analyzing 88 patients with gallstone disease. The patients were classified into two groups according to the presence of 10 predefined criteria. Of 53 patients with one or more risk factors (group 2), 26 harbored CBD calculi; none of 35 patients with no risk factors (group 1) had CBD stones. Jaundice correlated best, with a sensitivity of 69%; and pancreatitis had the lowest sensitivity (12%). Elevated serum bilirubin and alkaline phosphatase levels correlated better than liver enzymes and serum amylase. The sensitivity and negative predictive value of cholescintigraphy scanning for diagnosing CBD calculi were better than those of ultrasonography, the sensitivity being 84% versus 50% and the negative predictive value 95% versus 82%. Endoscopic retrograde cholangiopancreaticography was successful in 94% of the patients, and CBD calculi were diagnosed in 74%. Moreover, peroperative cholangiography was 100% sensitive with no false-positive results. Ultimately, a palpable stone at surgery was the best predictor. When all the criteria were analyzed, it was found that as the number of criteria increased so did the percentage of patients harboring CBD calculi.

Comparison of seven and fourteen days of lansoprazole, clarithromycin, and amoxicillin therapy for eradication of Helicobacter pylori: a report from India.

BACKGROUND: In developed countries, a 1-week regimen of combined proton pump inhibitors and two antibiotics is considered adequate for Helicobacter pylori eradication. However, there is a paucity of reports from developing countries on treatment duration of less than 14 days. We compared efficacy of 7 and 14 days of lansoprazole (L), clarithromycin (C), and amoxicillin (A) combinations for eradication of H. pylori. PATIENTS AND METHODS: Forty-six consecutive patients who presented with upper gastrointestinal symptoms and tested positive for H. pylori infection were included in the study. In every patient, after performance of upper gastrointestinal endoscopy, antral biopsies were obtained. H. pylori infection was diagnosed by positive rapid urease test and identification of organisms on antral histology. Patients were randomly selected to receive lansoprazole, 30 mg once daily, plus clarithromycin, 250 mg twice daily, plus amoxicillin, 500 mg three times daily for 2 weeks (group 1; n = 24; age, 36 +/- 12 years; 18 men) or 1 week (group 2; n = 22; age, 45 +/- 15 years; 12 men). One month after completion of treatment, repeat upper gastrointestinal endoscopy was performed. H. pylori eradication was defined as absence of organism on histopathological examination of both antrum and body of stomach and negative rapid urease test. RESULTS: Eradication rate was higher in group 1 (23 of 24; 96%) as compared to group 2 (12 of 22; 54%; p <.05). One patient in group 1 had diarrhea, and one patient in group two had skin rash and itching. CONCLUSIONS: Fourteen-day therapy with lansoprazole, clarithromycin, and amoxicillin is highly effective in eradication of H. pylori. Reducing duration of therapy to 7 days significantly lowers eradication rates.

[14C]-urea breath test to confirm eradication of Helicobacter pylori.

BACKGROUND: Treatment for Helicobacter pylori reduces ulcer recurrence. Eradication rates of the organism vary with different drug regimens from 30% to 90%. There is a need to identify patients who have failed treatment. [14C]-Urea breath test (UBT) is non-invasive, sensitive, safe and highly reliable test for diagnosis of H. pylori infection. As there is a paucity of reports on the utility of [14C]-UBT in confirming H. pylori eradication, this study was undertaken. METHODS: Thirty-eight patients (age 34 +/- 17 years, range 16-84 years, 27 men) with upper gastrointestinal symptoms underwent upper gastrointestinal endoscopy. Baseline H. pylori infection was diagnosed by identification of the organism on antral biopsies and positive rapid urease test (RUT). After 1 month of completion of treatment, repeat RUT and histological examination of antral endoscopic biopsies were performed. Eradication of H. pylori was defined as absence of the organism on histology, and negative RUT. The [14C]-UBT was performed using 185 kBq [14C]-urea dissolved in 300 mL water. Breath samples were collected once before ingestion of [14C]-urea, and subsequently at 5 and 15 min. Results were expressed as 14CO2/mmol CO2 exhaled as per cent of administered urea. RESULTS: Endoscopy revealed antral gastritis (n = 14), duodenal ulcer (n = 8), duodenitis (n = 2), oesophagitis (n = 1), antral gastritis and duodenal ulcer (n = 3), antral gastritis and duodenitis (n = 7) and normal upper gastrointestinal endoscopy (n = 3). All the 20 patients who were negative for H. pylori on RUT and histology, tested negative for H. pylori on [14C]-UBT. However, of 18 patients shown to have H. pylori infection on RUT and histology, 16 were positive for H. pylori on [14C]-UBT. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of [14C]-UBT were 100, 89, 91, 100 and 95% respectively. CONCLUSIONS: The [14C]-UBT is a reliable indicator of H. pylori eradication after treatment. It can obviate the need for antral biopsies to confirm eradication of H. pylori after completion of treatment.

Thyroid functions in lithium-treated psychiatric patients: a cross-sectional study.

In the present cross-sectional study, thyroid functions (viz. thyroid radioiodine uptake [RAIU] and serum T3, T4, and thyroid-stimulating hormone [TSH]) were evaluated in 24 healthy controls and 132 outdoor affective disorder patients. Eleven of these patients were to receive lithium (Li) and the remaining 121 patients were at different stages of Li treatment ranging from 0.7 to 240 mo. RAIU was found to increase significantly throughout the Li therapy and was associated with the corresponding rise in TSH levels. In totality, Li treatment induced subclinical hypothyroidism in 51/132 (39%) of patients. However, 8/51 patients who belonged to known iodine-deficient belt had abnormally high TSH (range 15.2-76.0 microIU/mL), low T4 (5.3+/-2.5 microg/dL), and normal T3 and at least 4 of these 8 patients were clinically hypothyroid. T4 levels declined significantly (p < 0.05) with Li treatment ranging from 61 to 240 mo as compared to the corresponding values in the pre-Li group. The T3/T4 ratio was found to be significantly higher with Li treatment ranging from 0.7 to 6 mo in comparison with the pre-Li group and this value returned to base levels after long-term Li therapy. High T3 and T4 were observed in 13% and 12% of the patients, respectively, as compared to the corresponding control values.

Vitamin E suppresses the induction of reactive oxygen species release by lipopolysaccharide, interleukin-1beta and tumor necrosis factor-alpha in rat alveolar macrophages.

Over the last decade, although investigations have suggested that vitamin E affects the immune response, not much is known about its affect on the alveolar macrophage functions. In the present study, we have investigated the effect of high vitamin E (DL-alpha-tocopheryl acetate, alpha-TA) supplementation for 10 d on the activation state of rat alveolar macrophages induced by lipopolysaccharide (LPS), interleukin (IL)-1beta or tumor necrosis factor (TNF)-alpha on the basis of their ability to produce reactive oxygen species (ROS), such as superoxide (O2-*) and H2O2. LPS treatment (1 and 10 microg/mL) caused 2.44 and 2.54-fold increases in O2-*, and 2.1 and 2.3-fold increases in H2O2, respectively, from alveolar macrophages (AMs) in the diet group fed 50 mg alpha-TA/kg. However, this enhancement was not observed for the AMs of the diet groups fed 250 or 1,250 mg alpha-TA/kg. Similar results were obtained on treating the AMs with proinflammatory cytokines IL-1beta or TNF-alpha. The observed suppression in ROS release in response to various stimulants may be due to the direct and/or indirect effect of high vitamin E (250 and 1,250 mg alpha-TA/kg diet) supplementation. It may therefore, be concluded that high alpha-TA supplementation in the diet modulates the activation of AMs in rats.

Normal limits of 14C-urea breath test.

BACKGROUND/AIMS: 14C-urea breath test has been widely used for diagnosis of Helicobacter pylori (H. pylori) infection. There is no general agreement on the cutoff values for determination of H. pylori negative subjects. We studied baseline values in subjects who were proved to be H. pylori negative and calculated the cutoff value of normalcy. A comparison of this test with other tests for diagnosis of H. pylori infection was also done. PATIENTS AND METHODS: 12 patients (mean age 34 +/- 14, range 22-65 years; 8 men) of non-ulcer dyspepsia were studied, who were proved to be H. pylori negative by rapid urease test, Gram's staining, histopathology and culture of gastric mucosal biopsies obtained four each from the antrum, body and fundus of the stomach. The controls included 12 patients (mean age 40 +/- 13, range 22-65 years, 9 men), who were positive for H. pylori on culture or combination of rapid urease test and histopathology or rapid urease test and Gram's stain. 14C-urea breath test was performed using 5 uCi of 14C-urea dissolved in 300 ml of water. Breath samples were collected once before ingestion of 14C urea and subsequently at 5, 15 and 30 minutes after ingestion and 14C-contents in the breath samples measured. Results were expressed as 14 CO2/mmol CO2 exhaled as percent of administered urea. RESULTS: The mean +/- SD 14-C value in H. pylori negative vs H. pylori positive patients at 5 minutes, 15 minutes and 30 minutes were found to be 0.003 +/- 0.003 vs 0.064 +/- 0.042 (p < 0.001), 0.002 +/- 0.001 vs 0.056 +/- 0.039 (p < 0.001) and 0.001 +/- 0.002 vs 0.041 +/- 0.026 (p < 0.001) respectively. The mean values of 14C-urea breath test were significantly lower in H. pylori negative patients as compared to H. pylori positive patients. Using receiver operating characteristic (ROC) analysis of the data, the cutoff values obtained were 0.01, 0.007 and 0.009 at 5 minutes, 15 minutes and 30 minutes respectively. CONCLUSIONS: 14C-urea breath test levels at 5, 15 and 30 minutes intervals are significantly lower in H. pylori negative patients as compared to H. pylori positive patients. This test has high sensitivity and specificity in detecting H. pylori infection.

Changes in rat alveolar macrophageal antioxidant defense and reactive oxygen species release by high dietary vitamin E.

For the past decade there has been emphasis on the immunomodulatory effects of vitamin E apart from its established role as a free radical scavenger. In alveolar macrophages (AMs), the role of vitamin E supplementation has not yet been investigated sufficiently. In the present study we have evaluated the effects of high vitamin E (DL-alpha-tocopheryl acetate, alpha-TA) supplementation for 10 d on rat-alveolar macrophageal antioxidant defense and reactive oxygen species (ROS) release. There was an increase in plasma vitamin E content from 5.22 +/- 1.30, at 50 mg to 12.23 +/- 1.06 and 22.32 +/- 2.02 micrograms/mL at 250 and 1,250 mg alpha-TA/kg dietary supplementation. Alveolar macrophage-vitamin E content enhanced by 56 to 75% at 250 and 1,250 mg alpha-TA diet as compared with control diet. Superoxide dismutase activity decreased and catalase and glutathione peroxidase activities increased significantly in AMs of 250 and 1,250 mg alpha-TA diet-fed rats. Reduced glutathione, total glutathione, and glutathione-S-transferase activity in AMs did not change significantly at any of the high doses of alpha-TA supplementation. On stimulation of AMs by phorbol-12-myristate-13-acetate (PMA), there was 2.8- and 3.5-fold enhancement in superoxide (O2-.) and H2O2 production, respectively, at 50 mg alpha-TA dose. But this increase by PMA could not take place in AMs from animals supplemented with 250 and 1,250 mg alpha-TA. It may therefore be concluded that high alpha-TA supplementation in diet may equip the AMs with a stronger defense against oxygen-free radical mediated damage to them.

Evaluation of 14C-urinary excretion and its comparison with 14CO2 in breath after 14C-urea administration in Helicobacter pylori infection.

OBJECTIVES: 1) to estimate levels of 14C-urinary excretion in Helicobacter pylori-infected and noninfected patients after 14C-urea ingestion, 2) to compare 14C-urinary excretion and 14CO2 breath results with biopsy findings, and 3) to find out correlation between 14C-urinary excretion with 14CO2 breath results, if any. METHODS: Twenty-four-hour 14C-urinary excretion was measured in 26 patients of non-ulcer dyspepsia after oral administration of 5 microCi 14C-urea to each patient. One-mmol CO2 breath samples at baseline, 2, 5, 15, and 45 min were collected and 14C content measured. Four gastric biopsies were obtained endoscopically from each patient for histology, culture, Gram staining, and rapid urease test. RESULTS: 14C-urinary excretion in H. pylori-positive patients was 27.38 +/- 13.35% (mean +/- SD) as compared to 67.05 +/- 14.19% in H. pylori-negative patients. Five-, 15-, and 45-min 14CO2 breath values in H. pylori-positive cases were 0.07 +/- 0.041%, 0.063 +/- 0.041%, and 0.028 +/- 0.017% of administered 14C-urea/mmol CO2 exhaled, respectively, which were significantly higher (p < 0.001) from their corresponding values in negative cases. The 14C-urinary excretion data, when compared with biopsies results, discriminated well in 17 of the 18 H. pylori-positive cases, resulting in sensitivity of 94.4%, specificity 100%, and diagnostic accuracy 96.1%, whereas 15 min 14CO2 breath results were 100% accurate. Strong negative correlation between 14C-urinary excretions and 15 min 14CO2 breath was obtained (r = -0.717, p < 0.001). CONCLUSIONS: Measurement of 14C in 24-h urine and in 15-min breath sample may be employed as a cross confirmatory reliable technique for the detection of viable H. pylori colonization.