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BACKGROUND: Due to the expression of urease, Helicobacter pylori is able to establish itself in the human stomach under acidic conditions. A novel host defence mechanism was recently proposed, suggesting that the formation of salivary nitrite in symbiosis with facultative anaerobic bacteria in the oropharynx, is aimed at enhancing the antimicrobial activity of gastric juice. AIMS: To investigate whether the addition of nitrite in physiological concentrations influences the resistance of H pylori to acid. METHODS: H pylori cultured from fresh gastric Biopsy specimens was exposed for 30 minutes to normal saline and to HCl/KCl buffer (0.2M) at pH 2 with urea (5 mM) added. The influence of potassium nitrite (50-1000 mumol/l) on bacterial survival was determined. RESULTS: Addition of nitrite (1 mM) to acidic solutions (pH 2) resulted in complete kill of H pylori within 30 minutes exposure time whereas acid alone allowed the organism to survive (p < 0.001). The antimicrobial effect of nitrite at pH 2 against H pylori was dose dependent and complete kill of organisms occurred at concentrations > or = 500 mumol/l. CONCLUSION: Acidified nitrite has anti-bacterial activity against H pylori. This should prompt further research into the effect of salivary nitrite on the survival of H pylori in the human stomach. 相似文献
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A novel Clostridium bifermentans strain toxic to mosquito larvae on ingestion was isolated from a soil sample collected from secondary forest floor. This strain was designated as serovar paraiba (C. b. paraiba) according to its specific H antigen. Clostridium bifermentans paraiba is most toxic to Anopheles maculatus Theobald larvae (LC50 = 0.038 mg/liter), whereas toxicity to Aedes aegypti (Linn.) (LC50 = 0.74 mg/liter) and Culex quinquefasciatus Say (LC50 = 0.11 mg/liter) larvae was 20 and 3 times lower, respectively. The toxicity to An. maculatus larvae is as high as that of Bacillus thuringiensis serovar israelensis. C. b. paraiba was also found to exhibit significant per os insecticidal activity toward adult Musca domestica (Linn.). 相似文献
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Juvenile chronic myelogenous leukemia (JCML) is an aggressive myeloproliferative disorder of childhood that differs both clinically and pathologically from adult type, Philadelphia chromosome positive chronic myelogenous leukemia, and from the other myeloproliferative disorders that are more common in adulthood. The disease can have widely varying clinical presentations and shares many features with the monosomy 7 syndrome and chronic myelomonocytic leukemia. With no specific marker chromosome, establishing the diagnosis can be difficult, and relies on a constellation of clinical, pathologic, and laboratory findings. This article discusses the differential diagnosis of JCML with an emphasis on the pathologic findings and laboratory data that are particularly important for confirming the diagnosis. The sensitivity, specificity, and clinical utility of cell culture colony assays are reviewed. Finally, current knowledge of the biology of JCML and some of the controversies regarding this disease are discussed. 相似文献
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V Gandhi W Plunkett H Kantarjian M Talpaz LE Robertson S O'Brien 《Canadian Metallurgical Quarterly》1998,16(7):2321-2331
PURPOSE: To determine the maximum-tolerated dose (MTD), toxicities, and antileukemic activity of hydroxyurea (HU) administered intravenously to patients with advanced-phase chronic myelogenous leukemia (CML). Further objectives were to analyze pharmacodynamic effect on deoxynucleotides (dNTPs) and to seek relationships between the decrease in dNTP pools and inhibition of DNA synthesis in CML blasts. PATIENTS AND METHODS: HU (8, 12, 18, 27, and 40 g/m2) was administered intravenously by a 24-hour continuous infusion to 19 adults with CML in blastic or accelerated phase. Plasma levels of HU were analyzed in all patients. To determine the role of HU in inhibiting ribonucleotide reductase, dNTP pools in the leukemia cells were quantitated. Correlations were sought with these parameters and DNA synthesis inhibition measured ex vivo by [3H]thymidine incorporation. RESULTS: The MTD of HU given as a 24-hour infusion was 27 g/m2. The dose-limiting toxicity was mucositis. There was a significant but transient myelosuppression, with nadir counts generally seen 3 to 4 days after the dose. The steady-state concentration of HU in plasma was achieved by 6 hours, and was proportional to the dose. There was a median 57% decrease in the deoxyadenosine triphosphate (dATP) pool in circulating blasts. In contrast, deoxyguanosine triphosphate (dGTP) and pyrimidine dNTPs were not significantly affected. The extent of DNA synthesis inhibition was related to the residual concentrations of intracellular dATP. CONCLUSION: A 24-hour infusion of HU results in significant but transient myelosuppression in advanced-phase CML. The specific decrease of intracellular dATP correlated with the inhibition of DNA synthesis in CML blasts. This pharmacodynamic action of HU provides a rationale for combination with other chemotherapeutic agents, the effects of which could be augmented by the decline in dATP pools. 相似文献
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I Dilek T Demirer C Ustün M Arat H Ko? M Beksa? H Erdi R Anadolu M Ozcan O Ilhan H Akan 《Canadian Metallurgical Quarterly》1998,21(11):1159-1161
Acquired ichthyosis (AI) has rarely been described following bone marrow transplantation (BMT). We report a 29-year-old male, who underwent allogeneic peripheral blood stem cell transplantation (alloPBSCT) for chronic myelogenous leukemia, and who developed AI associated with chronic graft-versus-host disease (cGVHD). Both of these disorders were treated successfully with cyclosporin A. We conclude that AI may be related to an autoimmune process on the basis of cGVHD, and dermathopathologic evaluation must be performed in patients with skin changes suggesting AI following allogeneic bone marrow transplantation. 相似文献
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CM Verfaillie 《Canadian Metallurgical Quarterly》1997,11(6):1079-1114
This article discusses briefly the molecular consequences of the BCR-ABL fusion gene. It then reviews the current evidence supporting the notion that chronic myelogenous leukemia in its chronic phase is a clonal, hematopoietic, stem cell disease in which malignant hematopoietic stem and progenitor cells respond to "normal" external proliferation and differentiation stimuli, but in which such responses are altered owing to defects in the stem and progenitor cells as a result of the BCR-ABL oncogene. 相似文献
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Two thirds of patients with chronic myelogenous leukemia do not have suitable donors for allogeneic transplantation. As for other leukemias, autografting may potentially be curative, because normal Ph- hematopoietic stem cells persist in the marrow and blood of patients with chronic myelogenous leukemia. Several studies indicate that use of unpurged autologous blood or marrow grafts may extend survival for patients undergoing transplantation in chronic phase. Ex vivo or in vivo purging of chronic myelogenous leukemia marrow or blood prior to autografting may result in increased cytogenetic remissions after transplantation in those patients in whom the Ph+ clone can be eliminated. However, when the Ph+ clone cannot be eliminated, use of purged rather than unpurged autografts provides no advantage and may be associated with increased graft failure. Although sustained cytogenetic remissions have not been observed, autografting may result in a plateau in the survival curve not observed with conventional chemotherapy. Efforts are currently directed toward developing improved methods of purging as well as posttransplantation treatments directed against leukemic cells persisting after myeloablative therapy. 相似文献
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N Wakimoto A Yokoyama Y Mukai N Kuwada T Yamashita T Matsumura Y Nakamura Y Kanatani N Nagata J Okabe-Kado Y Honma K Motoyoshi 《Canadian Metallurgical Quarterly》1998,67(3):313-318
OBJECTIVE: To adapt desktop computer software to objectively grade facial movement. DESIGN: The criteria of the facial nerve grading system by House and Brackmann, the current "gold standard," are prone to ambiguous interpretation. Proposed objective grading systems compare the movement of points on each side of the face or use subtraction and thresholding of digitized images of the face to yield images that represent moving areas of the face. The movement of a point on the face and the area of motion determined by digital subtraction were compared during an increasing smile in healthy subjects. The Nottingham system (calculated using measurement of the movement of 4 points on the face) using desktop computer software (Adobe Photoshop 3.0, Adobe Systems Inc, Mountain View, Calif) to measure movement of the points was compared with the system by House and Brackmann. The computer software was used to subtract digitized images and derive a facial movement score, which was compared with the scores of the systems by Nottingham and House and Brackmann. SETTING: Academic otologic practice. STUDY PARTICIPANTS: Nine patients with varying degrees of facial nerve disability and 7 individuals with normal facial nerve function. RESULTS: The movement of the oral commissure compared with the apparent area of movement of the face determined by digital subtraction had high intersubject variability. In patients with facial weakness, the Nottingham score had a correlation coefficient of -0.97 compared with the House and Brackmann grade, and the digital subtraction score had a correlation coefficient of -0.62 (paired Student t test). CONCLUSIONS: The desktop computer software can be used to calculate the Nottingham score. Digital subtraction as a measure of facial function warrants further study. 相似文献
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Interferon alpha (IFN alpha) has been used in the treatment of chronic myelogenous leukemia (CML). The initial trial was made in 1983 by Talpaz et al. Their first report suggested that IFN alpha treatment could achieve high hematological remission. The cause of the effect was unclear, but may be mediated through interaction cell surface membrane and inhibitory protein production. IFN alpha was related to some T cell immunity, and could be taken to be Ph1 positive cell inhibition by normal T cell. Although IFN alpha therapy has limited use with get Ph1 negative hematopoiesis, intensive treatment of this kind is needed to minimize Ph1 clone, using various therapy combination with IFN alpha. 相似文献
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JS Miller 《Canadian Metallurgical Quarterly》1998,12(1):173-206
Innovative therapies for chronic myelogenous leukemia (CML) have focused mainly on combining autologous transplantation with another modality of therapy for purging of the graft or treatment of the patient after transplant. Of the three categories of innovative therapies, two are based on studies that demonstrate the bcr/abl gene rearrangement in the pathogenesis of CML, whereas the third is based on the observation that allogeneic disparity is important to maintain remissions in CML. The rationale and data supporting these innovative approaches are reviewed in this article and future strategies are discussed. 相似文献
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The authors describe a 51-year-old man with chronic lymphocytic leukemia who presented with respiratory distress and then died suddenly while in hospital. Autopsy revealed pulmonary leukostasis and a large intracardiac mass containing mostly mature lymphocytes and fibrin. Although leukostasis and lymphocyte thrombi have been described (albeit rarely) in chronic lymphocytic leukemia, an intracardiac "clot" has not. It seems plausible that this intracardiac mass caused the patient's death. 相似文献
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We report on a patient with Adams-Oliver syndrome and report new findings: a chylous pleural effusion and juvenile chronic myelogenous leukemia. Also, our patient had congenital heart disease, confirming that heart lesions are a manifestation in this syndrome. The major manifestations of this disorder are summarized. Included are cases not previously recognized as having Adams-Oliver syndrome identified in a literature survey. Distal limb deficiency is commonest with more frequent and more severe involvement of the lower limbs. Scalp defects are the second commonest manifestation, while an underlying skull defect is not infrequent. Cutis marmorata telangiectatica and dilated scalp veins are significant signs of this condition. This review highlights unresolved questions about Adams-Oliver syndrome. 相似文献
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A Salar J Carratalà A Zurita E González-Barca A Gra?ena 《Canadian Metallurgical Quarterly》1998,83(7):670-672
Human infection due to CDC group IV c-2, a gram negative bacillous, are rare. We describe a case of nosocomial bacteremia caused by this organism in a neutropenic patient with acute lymphoblastic leukemia and include a literature review of CDC group IV c-2 infection in patients with hematologic malignancies. 相似文献
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Cardiac toxicity following the administration of chemotherapeutic agents is well documented. Vinca alkaloids, as well as high-dose cyclophosphamide, have been associated with myocardial ischemia. The present report describes a case of acute myocardial infarction occurring in a patient with no antecedent cardiac history who received both vincristine and conventional chemotherapeutic doses of cyclophosphamide for the treatment of chronic lymphocytic leukemia. Physicians should possess a heightened awareness of this potentially serious complication. 相似文献
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J Hasford M Baccarani R Hehlmann H Anseri S Tura E Zuffa 《Canadian Metallurgical Quarterly》1996,87(12):5384-5391
In 1994, the Italian and the German Chronic myeloid leukemia (CML) trials comparing interferon-alpha (IFN-alpha) with conventional chemotherapy were published. The survival advantage in favor of IFN-alpha compared with hydroxyurea (HU; 72 v 52 months) was significant in the Italian (P < .002), but not in the German trial (66 v 56 months, P < .44). We set up a collaborative study to identify the reasons for the different outcomes. There are major differences in the trial protocols concerning admission criteria, treatment strategy, and definitions. The German patients were older and more seriously sick. Fifty-two of the 327 patients in the German IFN and HU arms did not fulfil Italian admission criteria, and 41 of the 322 Italian patients did not fulfil German admission criteria. Using mutually uniform admission criteria, the median survival times of the IFN patients are 76 (Italian) and 72 (German) months (P = .56). The Italian group administered IFN combined with HU as needed, whereas the German group strictly used IFN as monotherapy with rerandomization to busulfan (BU) or HU after IFN resistance or intolerability. The differences seen between the Italian and the German trial results can be accounted for by objective differences in study design, especially the admission criteria, treatment strategy, and bias due to intention to treat analysis. The detailed analysis of the data suggests that the combination of IFN with HU as needed is more effective than either agent alone. 相似文献