958 resultados para Disease resistance


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We demonstrate aqueous phase biosynthesis of phase-pure metallic copper nanoparticles (CuNPs) using a silver resistant bacterium Morganella morganii. This is particularly important considering that there has been no report that demonstrates biosynthesis and stabilization of pure copper nanoparticles in the aqueous phase. Electrochemical analysis of bacterial cells exposed to Cu2+ ions provides new insights into the mechanistic aspect of Cu2+ ion reduction within the bacterial cell and indicates a strong link between the silver and copper resistance machinery of bacteria in the context of metal ion reduction. The outcomes of this study take us a step closer towards designing rational strategies for biosynthesis of different metal nanoparticles using microorganisms.

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The morbidity and mortality rates of renal disease in Indigenous Australians are significantly higher than those of non-Indigenous Australians, and are increasing. The dominant discourses of renal disease currently predicate this as essentially a client problem, rather than (for example) a health care system problem. These discourses are indicative of the dominant “white” paradigm of health care, which fosters an expectation of assimilation by the marginalised “other.” In this paper, we draw upon a sociological methodology (the actor network approach) and a qualitative method (discourse analysis) to tease out these issues in Indigenous renal disease. Based on empirical data, we explore on the one hand the requirements of the discourses, technologies and practices that have been developed for a particular type of renal patient and health system in Australia. On the other, we examine the cultural and practical specificities entailed in the performance of these technologies and practices in the Indigenous Australian context. The meeting of the praxiographic orientation of the actor network approach—which has been called “the politics of what” (Mol 2002)—and the sociocultural concerns of discourse analysis does provide a useful guide as to “what to do” when confronted with issues in health care that currently seems unfathomable. Our praxiographic analysis of the discourse enabled us to understand the difficulties involved in translating renal health care networks across cultural contexts in Australia and to understand the dynamic and contested nature of these networks. The actor network approach has its limitations, however, particularly in the articulation of possible strategies to align two disparate systems in a way that would ensure better health care for Indigenous renal patients. In this paper we will discuss some of the problems we encountered in drawing on this methodology in our attempt to unearth practical solutions to the conundrums our data presented.

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Objective To estimate the burden of diseases in Shandong province by the means of DALY (Disability- adjusted life year) thus to investigate the key public health problems referencing for health policy making. Methods DALYs were calculated following the procedures developed for the Global Burden of Disease (GBD) study to ensure comparability. We measured YLLs using the mortality data of 19 Disease Surveillance Points (DSPs) in Shandong Province during 2000 and 2005. YLDs were estimated based on data for WPRO in the 2002 GBD study published by WHO. Results During this period, the average DALYs loss by all causes for the residents of DSPs in Shandong was 149.74 per thousand persons each year. Noncommunicable diseases accounted for 76.63% of the disability adjusted life years, communicable diseases and other disorders represented 14.13%, and injuries 9.24%. Nearly half of the DALYs (45%) happened among the elderly (60+). Malignant neoplasm was the number one cause of DALYs loss in the male, followed by neuropsychiatric disorder, injury, cerebrovascular disease, heart disease,etc. However, neuropsychiatric disorder possessed the largest single contributor to DALY in the female and followed by heart disease, malignant neoplasm, cerebrovascular disease and respiratory disease. Conclusion Non-communicable diseases such as circulatory diseases, neuropsychiatric disorders and malignant neoplasms were the main causes of disease burden in Shandong province. The importance of neuropsychiatric disorders was more striking and should be recognized properly. The lack of morbidity data is the main limitation of this study. Abstract in Chinese 目的 应用伤残调整寿命年测量山东省居民疾病负担,提出该地区主要卫生问题,为卫生决策提供科学依据. 方法 以山东省2000-2005年19个疾病监测点的死因监测资料为基础,利用世界卫生组织(WHO)提供的方法计算不同疾病在不同性别年龄人群所造成的伤残调整寿命年(DALYs),其中,YIJDs根据WHO公布的亚太区2002年疾病负担数据进行估算. 结果 2000-2005年山东省疾病监测系统居民因为早死和残疾年平均损失149.74个DALYs/千人,其中,76.6%的DALYs损失因慢性非传染性疾病所致,14.1%由传染性疾病等引起,9.2%因为意外伤害造成;接近1/2(45%)的DALYs损失发生在60岁以上人群;恶性肿瘤为造成男性居民DALYs损失的首位原因,其次为精神行为疾患、意外伤害、脑血管病和心脏病等,女性居民则以精神行为疾患为DALYs首位原因,其次为心脏病、恶性肿瘤、脑血管病和呼吸系统疾病. 结论 以循环系统疾病、精神行为疾惠和恶性肿瘤为首的慢性非传染性疾病为造成山东省疾病负担DALYs损失的主要原因.对于精神行为疾患的重要性的认识有待于进一步提高,研究的主要局限性在于发病率资料的缺乏.

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Background Recurrent protracted bacterial bronchitis (PBB), chronic suppurative lung disease (CSLD) and bronchiectasis are characterised by a chronic wet cough and are important causes of childhood respiratory morbidity globally. Haemophilus influenzae and Streptococcus pneumoniae are the most commonly associated pathogens. As respiratory exacerbations impair quality of life and may be associated with disease progression, we will determine if the novel 10-valent pneumococcal-Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) reduces exacerbations in these children. Methods A multi-centre, parallel group, double-blind, randomised controlled trial in tertiary paediatric centres from three Australian cities is planned. Two hundred six children aged 18 months to 14 years with recurrent PBB, CSLD or bronchiectasis will be randomised to receive either two doses of PHiD-CV or control meningococcal (ACYW(135)) conjugate vaccine 2 months apart and followed for 12 months after the second vaccine dose. Randomisation will be stratified by site, age (<6 years and >= 6 years) and aetiology (recurrent PBB or CSLD/bronchiectasis). Clinical histories, respiratory status (including spirometry in children aged >= 6 years), nasopharyngeal and saliva swabs, and serum will be collected at baseline and at 2, 3, 8 and 14 months post-enrolment. Local and systemic reactions will be recorded on daily diaries for 7 and 30 days, respectively, following each vaccine dose and serious adverse events monitored throughout the trial. Fortnightly, parental contact will help record respiratory exacerbations. The primary outcome is the incidence of respiratory exacerbations in the 12 months following the second vaccine dose. Secondary outcomes include: nasopharyngeal carriage of H. influenzae and S. pneumoniae vaccine and vaccine-related serotypes; systemic and mucosal immune responses to H. influenzae proteins and S. pneumoniae vaccine and vaccine-related serotypes; impact upon lung function in children aged >= 6 years; and vaccine safety. Discussion As H. influenzae is the most common bacterial pathogen associated with these chronic respiratory diseases in children, a novel pneumococcal conjugate vaccine that also impacts upon H. influenzae and helps prevent respiratory exacerbations would assist clinical management with potential short- and long-term health benefits. Our study will be the first to assess vaccine efficacy targeting H. influenzae in children with recurrent PBB, CSLD and bronchiectasis.

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Objective To estimate the incidence and severity of invasive group A streptococcal infection in Victoria, Australia. Design Prospective active surveillance study. Setting Public and private laboratories, hospitals and general practitioners throughout Victoria. Patients eople in Victoria diagnosed with group A streptococcal disease notified to the surveillance system between 1 March 2002 and 31 August 2004. Main outcome measure Confirmed invasive group A streptococcal disease. Results We identified 333 confirmed cases: an average annualised incidence rate of 2.7 (95% CI, 2.3-3.2) per 100000 population per year. Rates were highest in people aged 65 years and older and those younger than 5 years. The case-fatality rate was 7.8%. Streptococcal toxic shock syndrome occurred in 48 patients (14.4%), with a case-fatality rate of 23%. Thirty cases of necrotising fasciitis were reported; five (17%) of these patients died. Type 1 (23%) was the most frequently identified emm sequence type in all, age groups. All tested isolates were susceptible to penicillin and clindamycin. Two isolates (4%) were resistant to erythromycin. Conclusion The incidence of invasive group A streptococcal disease in temperate Australia is greater than previously appreciated and warrants greater public health attention, including its designation as a notifiable disease.

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On 1 August 1997, the Friday afternoon of the start of a three day weekend (NT Picnic Day Monday 4 August) a case of suspected meningococcal disease was notified to CDC Katherine by an experienced, long serving, local GP...

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On Saturday, 25 October 1997 a five year old boy died in the Intensive Care Unit (ICU) of Royal Darwin Hospital (RDH) from meningococcal disease. While disease is expected throughout Australia during the late winter and early spring months, and deaths occur, this case was remarkable in the Northern Territory with respect to the unprecedented public response to media reports of the death.

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Exogenous prostacyclin is effective in reducing pulmonary vascular resistance in some forms of human pulmonary hypertension (PH). To explore whether endogenous prostaglandins played a similar role in pulmonary hypertension, we examined the effect of deleting cyclooxygenase (COX)-gene isoforms in a chronic hypoxia model of PH. Pulmonary hypertension, examined by direct measurement of right ventricular end systolic pressure (RVESP), right ventricular hypertrophy (n = 8), and hematocrit (n = 3), was induced by 3 weeks of hypobarichypoxia in wild-type and COX-knockout (KO) mice. RVESP was increased in wild-type hypoxic mice compared with normoxic controls (24.4 ± 1.4 versus 13.8 ± 1.9 mm Hg; n = 8; p < 0.05). COX-2 KO mice showed a greater increase in RVESP following hypoxia (36.8 ± 2.7 mm Hg; p < 0.05). Urinary thromboxane (TX)B2 excretion increased following hypoxia (44.6 ± 11.1 versus 14.7 ± 1.8 ng/ml; n = 6; p < 0.05), an effect that was exacerbated by COX-2 gene disruption (54.5 ± 10.8 ng/ml; n = 6). In contrast, the increase in 6-keto-prostacyclin1α excretion following hypoxia was reduced by COX-2 gene disruption (29 ± 3 versus 52 ± 4.6 ng/ml; p < 0.01). Tail cut bleed times were lower following hypoxia, and there was evidence of intravascular thrombosis in lung vessels that was exacerbated by disruption of COX-2 and reduced by deletion of COX-1. The TXA2/endoperoxide receptor antagonist ifetroban (50 mg/kg/day) offset the effect of deleting the COX-2 gene, attenuating the hypoxia-induced rise in RVESP and intravascular thrombosis. COX-2 gene deletion exacerbates pulmonary hypertension, enhances sensitivity to TXA2, and induces intravascular thrombosis in response to hypoxia. The data provide evidence that endogenous prostaglandins modulate the pulmonary response to hypoxia. Copyright © 2008 by The American Society for Pharmacology and Experimental Therapeutics.

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Based on promising preclinical efficacy of bortezomib in mesothelioma, a single-arm phase II trial (Ireland Cooperative Oncology Research Group 05-10 study), with Simon's two-stage design, was undertaken to assess efficacy of bortezomib monotherapy in the first-line (poor performance status) and second-line settings. The Bcl-2 homology domain 3-only protein Noxa has been implicated as a key inducer of apoptosis by bortezomib. Thus, in a biomarker research substudy, we hypothesized that deficiency in Noxa expression might correlate with resistance. In the second-line setting, 23 patients were enrolled. Partial response was confirmed in one patient (4.8%) who received four cycles of bortezomib. One patient had stable disease; however, progression occurred in the majority of patients within the first two cycles. Median progression-free survival and overall survival were 2.1 and 5.8 months, respectively. In the first-line setting, ten patients were accrued, and there was no evidence of objective response. In the tumor analysis, expression of Noxa was seen in all biopsies. Bortezomib monotherapy exhibits insufficient activity to warrant further investigation in unselected patients with mesothelioma. © 2012 by the International Association for the Study of Lung.

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The majority of patients with non-small-cell lung cancer (NSCLC) present with advanced disease, with targeted therapies providing some improvement in clinical outcomes. The epidermal growth factor receptor (EGFR) tyrosine kinase (TK) plays an important role in the pathogenesis of NSCLC. Tyrosine kinase inhibitors (TKIs), which target the EGFR TK domain, have proven to be an effective treatment strategy; however, patient responses to treatment vary considerably. Therefore, the identification of patients most likely to respond to treatment is essential to optimise the benefit of TKIs. Tumour-associated activating mutations in EGFR can identify patients with NSCLC who are likely to have a good response to TKIs. Nonetheless, the majority of patients relapse within a year of starting treatment. Studies of tumours at relapse have demonstrated expression of a T790M mutation in exon 20 of the EGFR TK domain in approximately 50% of cases. Although conferring resistance to reversible TKIs, these patients may remain sensitive to new-generation irreversible/panerb inhibitors. A number of techniques have been employed for genotypic assessment of tumourassociated DNA to identify EGFR mutations, each of which has advantages and disadvantages. This review presents an overview of the current methodologies used to identify such molecular markers. Recent developments in technology may make the monitoring of changes in patients' tumour genotypes easier in clinical practice, which may enable patients' treatment regimens to be tailored during the course of their disease, potentially leading to improved patient outcomes.

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Objectives: Superficial bladder cancer (SBC) presents a difficult clinical dilemma at diagnosis as only a small subgroup of patients will subsequently develop invasive disease. Study of cancer biology has found that angiogenesis is central to growth and spread. This study examines the relationship between the angiogenic inhibitory factor Thrombospondin-1 (TSP-1) at initial presentation and subsequent progression of SBC. Methods: Using immunohistochemistry, 220 cases of SBC were examined for pattern and extent of expression of TSP-1 at initial presentation. Results: TSP-1 was detected in perivascular tissue, at the epithelial-stromal junction, in the stroma and in tumour cells and reduced perivascular TSP-1 staining at presentation was an independent predictive factor for the subsequent development of muscle invasive or metastatic disease. Conclusion: This adds further weight to the theory that TSP-1 plays a major part in the biology of bladder cancer possibly through the control of angiogenesis. © 2002 Elsevier Science B.V. All rights reserved.

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The 'histone code' is a well-established hypothesis describing the idea that specific patterns of post-translational modifications to histones act like a molecular 'code' recognized and used by non-histone proteins to regulate specific chromatin functions. One modification, which has received significant attention, is that of histone acetylation. The enzymes that regulate this modification are described as lysine acetyltransferases or KATs, and histone deacetylases or HDACs. Due to their conserved catalytic domain HDACs have been actively targeted as a therapeutic target. The pro-inflammatory environment is increasingly being recognized as a critical element for both degenerative diseases and cancer. The present review will discuss the current knowledge surrounding the clinical potential and current development of histone deacetylases for the treatment of diseases for which a pro-inflammatory environment plays important roles, and the molecular mechanisms by which such inhibitors may play important functions in modulating the pro-inflammatory environment. © 2009 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

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Recent studies have demonstrated that angiogenesis and suppressed cell- mediated immunity (CMI) play a central role in the pathogenesis of malignant disease facilitating tumour growth, invasion and metastasis. In the majority of tumours, the malignant process is preceded by a pathological condition or exposure to an irritant which itself is associated with the induction of angiogenesis and/or suppressed CMI. These include: cigarette smoking, chronic bronchitis and lung cancer; chronic oesophagitis and oesophageal cancer; chronic viral infections such as human papilloma virus and ano-genital cancers, chronic hepatitis B and C and hepatocellular carcinoma, and Epstein- Barr virus (EBV) and lymphomas; chronic inflammatory conditions such as Crohn's disease and ulcerative colitis and colorectal cancer; asbestos exposure and mesothelioma and excessive sunlight exposure/sunburn and malignant melanoma. Chronic exposure to growth factors (insulin-like growth factor-I in acromegaly), mutations in tumour suppressor genes (TP53 in Li Fraumeni syndrome) and long-term exposure to immunosuppressive agents (cyclosporin A) may also give rise to similar environments and are associated with the development of a range of solid tumours. The increased blood supply would facilitate the development and proliferation of an abnormal clone or clones of cells arising as the result of: (a) an inherited genetic abnormality; and/or (b) acquired somatic mutations, the latter due to local production and/or enhanced delivery of carcinogens and mutagenic growth factors. With progressive detrimental mutations and growth-induced tumour hypoxia, the transformed cell, to a lesser or greater extent, may amplify the angiogenic process and CMI suppression, thereby facilitating further tumour growth and metastasis. There is accumulating evidence that long-term treatment with cyclo-oxygenase inhibitors (aspirin and indomethacin), cytokines such as interferon-α, anti-oestrogens (tamoxifen and raloxifene) and captopril significantly reduces the incidence of solid tumours such as breast and colorectal cancer. These agents are anti-angiogenic and, in the case of aspirin, indomethacin and interferon-α have proven immunomodulatory effects. Collectively these observations indicate that angiogenesis and suppressed CMI play a central role in the development and progression of malignant disease. (C) 2000 Elsevier Science Ltd.