219 research outputs found

    comparison of three adjuvant chemotherapy regimes using an extended log-logistic model in women with operable breast cancer

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    Objective: The main objective of the present study was to compare the effects of three common chemotherapy regimes in terms of disease-free survival (DFS) of breast cancer (BC) patients; the three explored regimes were taxane-based, anthracycline-based and CMF (cyclophosphamide methotrexate and 5-fluorouracil). Materials and methods: In this historical-cohort study, we obtained the information of 62 patients with confirmed BC in non-metastatic stage and followed them for 8 years. All the patients had undergone modified radical mastectomy surgery and had received adjuvant chemotherapy in three medical centers in Tehran, Iran. DFS was considered as the end-point. Afterwards, an extended log-logistic regression model was used to compare these regimes. Results: The mean (SD) age of patients was 49.0 (10.3) years. The median time of follow-up was 20.0 months and the probability of 5-years DFS was 0.48. Survival analysis indicated that the type of chemotherapy (OR(CMF vs. taxane) = 0.33, OR(anthracycline vs. taxane) = 0.74), grade (OR(III vs. I or II) = 0.35), tumor size (OR(>5cm vs. <5cm)= 0.179) and nodal involvements (OR(Yes vs. No)= 0.36) affected DFS. Conclusion: The current study revealed that the efficacy of taxane-based, in terms of DFS, was more than CMF (p = 0.05). Moreover, taxane-based chemotherapy prolonged DFS more than anthracycline-based one although the difference was not significant (p= 0.63). Finally, considering the importance of tumor size, histological grade and number of involved lymph nodes in lengthening DFS, it is crucial to highlight the role of public education and screening programs in order to detect tumor in its early stages

    Distributions attaining secret key at a rate of the conditional mutual information

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    © International Association for Cryptologic Research 2015. In this paper we consider the problem of extracting secret key from an eavesdropped source pXY Z at a rate given by the conditional mutual information. We investigate this question under three different scenarios: (i) Alice (X) and Bob (Y) are unable to communicate but share common randomness with the eavesdropper Eve (Z), (ii) Alice and Bob are allowed one-way public communication, and (iii) Alice and Bob are allowed two-way public communication. Distributions having a key rate of the conditional mutual information are precisely those in which a “helping” Eve offers Alice and Bob no greater advantage for obtaining secret key than a fully adversarial one. For each of the above scenarios, strong necessary conditions are derived on the structure of distributions attaining a secret key rate of I(X: Y |Z). In obtaining our results, we completely solve the problem of secret key distillation under scenario (i) and identify H(S|Z) to be the optimal key rate using shared randomness, where S is the Gàcs-Körner Common Information. We thus provide an operational interpretation of the conditional Gàcs- Körner Common Information. Additionally, we introduce simple example distributions in which the rate I(X: Y |Z) is achievable if and only if two-way communication is allowed

    Certainly Unsupervisable States

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    This paper proposes an abstraction method for compositional synthesis. Synthesis is a method to automatically compute a control program or supervisor that restricts the behaviour of a given system to ensure safety and liveness. Compositional synthesis uses repeated abstraction and simplification to combat the state-space explosion problem for large systems. The abstraction method proposed in this paper finds and removes the so-called certainly unsupervisable states. By removing these states at an early stage, the final state space can be reduced substantially. The paper describes an algorithm with cubic time complexity to compute the largest possible set of removable states. A practical example demonstrates the feasibility of the method to solve real-world problems

    Phosphopantetheinyl transferase (Ppt)-mediated biosynthesis of lysine, but not siderophores or DHN melanin, is required for virulence of Zymoseptoria tritici on wheat

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    Zymoseptoria tritici is the causal agent of Septoria tritici blotch (STB) disease of wheat. Z. tritici is an apoplastic fungal pathogen, which does not penetrate plant cells at any stage of infection, and has a long initial period of symptomless leaf colonisation. During this phase it is unclear to what extent the fungus can access host plant nutrients or communicate with plant cells. Several important primary and secondary metabolite pathways in fungi are regulated by the post-translational activator phosphopantetheinyl transferase (Ppt) which provides an essential co-factor for lysine biosynthesis and the activities of non-ribosomal peptide synthases (NRPS) and polyketide synthases (PKS). To investigate the relative importance of lysine biosynthesis, NRPS-based siderophore production and PKS-based DHN melanin biosynthesis, we generated deletion mutants of ZtPpt. The ?ZtPpt strains were auxotrophic for lysine and iron, non-melanised and non-pathogenic on wheat. Deletion of the three target genes likely affected by ZtPpt loss of function (Aar- lysine; Nrps1-siderophore and Pks1- melanin), highlighted that lysine auxotrophy was the main contributing factor for loss of virulence, with no reduction caused by loss of siderophore production or melanisation. This reveals Ppt, and the lysine biosynthesis pathway, as potential targets for fungicides effective against Z. tritici

    Treatment and prognosis of epithelial ovarian cancer. Five year multi-center study

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    Objective: To study the response rate for common chemotherapy regimens, and the progression free survival analysis in ovarian cancer in Tehran. Methods: Ninety-eight women with confirmed ovarian cancer who had surgery, followed by chemotherapy at the 3 hospitals in (Fayazbakhsh, Shohadayee Tajrish, and Imam-Hossein), Tehran, Iran, between 1997 and 2003 were enrolled in this retrospective descriptive study. Data regarding age, pathologic variations, surgical procedures, chemotherapy regimens, response rates, and time to progression of the disease were collected. Response rate was evaluated for 51 patients with epithelial cancer. Results: From a total of 98 patients, there were 81 (82.6) epithelial, 12 (12.2) germ cell, 4 (4.1) granulosa cell tumors, and one case of lymphoma. Staging with optimal residue was performed for 18 patients. Stage III was the most common stage (44.9). In 71.4 of patients, complete or partial response was seen, while the other patients showed stable, or progressive disease. The most important prognostic factors were the initial stage (p=0.034), and the extent of surgical procedure (p=0.045). Median disease-free survival was 52.6 months. Although, higher response rate was produced by taxane-based regimen in comparison with cisplatin-cyclophosphamide regimen (78.2 versus 71.4), but it was not statistically significant (p=0.275). Median age (49.6 years) of our patients is lower than expected. Besides, a large proportion of the patients are referred in advanced stages. Conclusion: New chemotherapy practically has made no significant higher response rate

    α-Amylase inhibitory property, antioxidant activity and toxicological study of Salvia chloroleuca

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    Abstract Background and objectives: Salvia chloroleuca Rech. f. &amp; Allen., is an endemic species growing wildly in north east and center parts of Iran but there is no information about its safety. To provide information about the safety of the species, we evaluated its acute and sub chronic toxicity in rats. Methods: In acute toxicity study, the aqueous methanol (80%) extract at a single dose of 2000 mg/kg/day was administered orally to male and female rats and signs of toxicity two weeks after administration were observed. For the subchronic toxicity test, the extract at doses of 250, 500 and 1000 mg/kg/day were orally administered to the rats of both sexes for 45 days. Mortality, clinical signs of toxicity and body weight changes were monitored during the study. Moreover, α-amylase enzyme inhibition, total phenol content, and antioxidant (DPPH and FRAP assays) activity of different fractions of aerial part were evaluated. Results: The methanol and aqueous methanol (80%) extracts showed α-amylase enzyme inhibition with IC 50 values 14.03 mg/mL and 18.05 mg/mL, respectively. The IC 50 value for ethyl acetate, methanol and aqueous methanol (80%) extracts in radical scavenging assay were calculated as 288.83, 97.93, and 108.02 μg/mL, respectively. Among all extracts, methanol (228.4±12.05) demonstrated the highest FRAP value, followed by methanol (80%) extract (220.4±8.08) and ethyl acetate extract (156.4±10.06). In acute toxicity and subchronic study, neither mortality nor changes in behavior or any other parameter were observed. Conclusion: Our findings indicate potent in vitro α-amylase and antioxidant activity of S. chloroleuca and propose its potential as an anti-diabetic agent for treatment of noninsulin-dependent diabetes mellitus (NIDDM) patients

    An update on the human and animal enteric pathogen Clostridium perfringens

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    Clostridium perfringens, a rapid-growing pathogen known to secrete an arsenal of >20 virulent toxins, has been associated with intestinal diseases in both animals and humans throughout the past century. Recent advances in genomic analysis and experimental systems make it timely to re-visit this clinically and veterinary important pathogen. This Review will summarise our understanding of the genomics and virulence-linked factors, including antimicrobial potentials and secreted toxins of this gut pathogen, and then its up-to-date clinical epidemiology and biological role in the pathogenesis of several important human and animal-associated intestinal diseases, including pre-term necrotising enterocolitis. Finally, we highlight some of the important unresolved questions in relation to C. perfringens-mediated infections, and implications for future research directions

    Intestinal lesions in dogs with acute hemorrhagic diarrhea syndrome associated with netF-positive Clostridium perfringens type A

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    Acute hemorrhagic diarrhea syndrome (AHDS), formerly named canine hemorrhagic gastroenteritis, is one of the most common causes of acute hemorrhagic diarrhea in dogs, and is characterized by acute onset of diarrhea, vomiting, and hemoconcentration. To date, histologic examinations have been limited to postmortem specimens of only a few dogs with AHDS. Thus, the aim of our study was to describe in detail the distribution, character, and grade of microscopic lesions, and to investigate the etiology of AHDS. Our study comprised 10 dogs with AHDS and 9 control dogs of various breeds, age, and sex. Endoscopic biopsies of the gastrointestinal tract were taken and examined histologically (H&E, Giemsa), immunohistochemically (Clostridium spp., parvovirus), and bacteriologically. The main findings were acute necrotizing and neutrophilic enterocolitis (9 of 10) with histologic detection of clostridia-like, gram-positive bacteria on the necrotic mucosal surface (9 of 10). Clostridium perfringens isolated from the duodenum was identified as type A (5 of 5) by multiplex PCR (5 of 5). In addition, each of the 5 genotyped isolates encoded the pore-forming toxin netF. Clostridium spp. (not C. perfringens) were cultured from duodenal biopsies in 2 of 9 control dogs. These findings suggest that the pore-forming netF toxin is responsible for the necrotizing lesions in the intestines of a significant proportion of dogs with AHDS. Given that the stomach was not involved in the process, the term acute hemorrhagic diarrhea syndrome seems more appropriate than the frequently used term hemorrhagic gastroenteritis

    Human Uterine Wall Tension Trajectories and the Onset of Parturition

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    Uterine wall tension is thought to be an important determinant of the onset of labor in pregnant women. We characterize human uterine wall tension using ultrasound from the second trimester of pregnancy until parturition and compare preterm, term and twin pregnancies. A total of 320 pregnant women were followed from first antenatal visit to delivery during the period 2000–2004 at the John Hunter Hospital, NSW, Australia. The uterine wall thickness, length, anterior-posterior diameter and transverse diameter were determined by serial ultrasounds. Subjects were divided into three groups: women with singleton pregnancies and spontaneous labor onset, either preterm or term and women with twin pregnancies. Intrauterine pressure results from the literature were combined with our data to form trajectories for uterine wall thickness, volume and tension for each woman using the prolate ellipsoid method and the groups were compared at 20, 25 and 30 weeks gestation. Uterine wall tension followed an exponential curve, with results increasing throughout pregnancy with the site of maximum tension on the anterior wall. For those delivering preterm, uterine wall thickness was increased compared with term. For twin pregnancies intrauterine volume was increased compared to singletons (), but wall thickness was not. There was no evidence for increased tension in those delivering preterm or those with twin gestations. These data are not consistent with a role for high uterine wall tension as a causal factor in preterm spontaneous labor in singleton or twin gestations. It seems likely that hormonal differences in multiple gestations are responsible for increased rates of preterm birth in this group rather than increased tension
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