252 research outputs found

    Mapping and monitoring geomorphological processes in mountainous areas using PSI data: Central Pyrenees case study

    Get PDF
    In this paper the Stable Point Network technique, an established Persistent Scatterer InSAR (PSI) technique, (SPN), has been applied for the first time to the analysis of several geomorphological processes present in the Gállego river basin (Central Pyrenees, Spain). The SPN coherence based approach has been used to process three different SAR images datasets covering two temporal periods: 1995 to 2001 and 2001 to 2007. This approach has permitted the detection of more than 40 000 natural ground targets or Persistent Scatterers (PSs) in the study area, characterised by the presence of vegetation and a low urban density. Derived displacement maps have permitted the detection and monitoring of deformations in landslides, alluvial fans and erosive areas. In the first section, the study area is introduced. Then the specifics of the SPN processing are presented. The deformation results estimated with the SPN technique for the different processed datasets are compared and analysed with previous available geo-information. Then several detailed studies are presented to illustrate the processes detected by the satellite based analysis. In addition, a comparison between the performance of ERS and ENVISAT satellites with terrestrial SAR has demonstrates that these are complementary techniques, which can be integrated in order to monitor deformation processes, like landslides, that over the same monitoring area may show very different ranges of movement. The most relevant conclusions of this work are finally discussed

    Ground deformation detection of the greater area of Thessaloniki (Northern Greece) using radar interferometry techniques

    Get PDF
    In the present study SAR interferometric techniques (stacking of conventional interferograms and Permanent Scatterers), using images from satellites ERS-1 and 2, have been applied to the region of Thessaloniki (northern Greece). The period covered by the images is 1992–2000. Both techniques gave good quantitative and qualitative results. The interferometric products were used to study ground surface deformation phenomena that could be related to the local tectonic context, the exploitation of underground water and sediments compaction. <br><br> The city of Thessaloniki shows relatively stable ground conditions. Subsidence in four locations, mainly in the area surrounding the city of Thessaloniki, has been detected and assessed. Two of the sites (Sindos-Kalochori and Langadhas) were already known from previous studies as subsiding areas, using ground base measurements. On the contrary the other two sites in the northern suburbs of Thessaloniki (Oreokastro) and in the south-east (airport area) were unknown as areas of subsidence. A further investigation based on fieldwork is needed in these two areas. Finally, an attempt to interpret the observed deformation, according to the geological regime of the area and its anthropogenic activities, has been carried out

    Incidence of malignant neoplasms among HIV-infected persons in Scotland

    Get PDF
    Among 2574 persons diagnosed with HIV throughout Scotland and observed over the period 1981-1996, cancer incidence compared to the general population was 11 times higher overall; among homosexual/bisexual males, it was 21 times higher and among injecting drug users, haemophiliacs and heterosexuals it was five times higher, mostly due to AIDS-defining neoplasms. However, liver, lung and skin cancers (all non-AIDS-defining) were also significantly increased

    Staphylococcus aureus biofilm properties and chronic rhinosinusitis severity scores correlate positively with total CD4+ T-cell frequencies and inversely with its Th1, Th17 and regulatory cell frequencies.

    Get PDF
    OnlinePublChronic rhinosinusitis (CRS) represents chronic inflammation of the sinus mucosa characterised by dysfunction of the sinuses' natural defence mechanisms and induction of different inflammatory pathways ranging from a Th1 to a Th2 predominant polarisation. Recalcitrant CRS is associated with Staphylococcus aureus dominant mucosal biofilms; however, S. aureus colonisation of the sinonasal mucosa has also been observed in healthy individuals challenging the significance of S. aureus in CRS pathogenesis. We aimed to investigate the relationship between CRS key inflammatory markers, S. aureus biofilm properties/virulence genes and the severity of the disease. Tissue samples were collected during endoscopic sinus surgery from the ethmoid sinuses of CRS patients with (CRSwNP) and without (CRSsNP) nasal polyps and controls (n = 59). CD3+ T-cell subset frequencies and key inflammatory markers of CD4+ helper T cells were determined using FACS analysis. Sinonasal S. aureus clinical isolates were isolated (n = 26), sequenced and grown into biofilm in vitro, followed by determining their properties, including metabolic activity, biomass, colony-forming units and exoprotein production. Disease severity was assessed using Lund-Mackay radiologic scores, Lund-Kennedy endoscopic scores and SNOT22 quality of life scores. Our results showed that S. aureus biofilm properties and CRS severity scores correlated positively with total CD4+ T-cell frequencies but looking into CD4+ T-cell subsets showed an inverse correlation with Th1 and Th17 cell frequencies. CD4+ T-cell frequencies were higher in patients harbouring lukF.PV-positive S. aureus while its regulatory and Th17 cell subset frequencies were lower in patients carrying sea- and sarT/U-positive S. aureus. Recalcitrant CRS is characterised by increased S. aureus biofilm properties in relation to increased total CD4+ helper T-cell frequencies and reduced frequencies of its Th1, Th17 and regulatory T-cell subsets. These findings offer insights into the pathophysiology of CRS and could lead to the development of more targeted therapies.Gohar Shaghayegh, Clare Cooksley, George Bouras, Roshan Nepal, Ghais Houtak, Beula Subashini Panchatcharam, Kevin Aaron Fenix, Alkis James Psaltis, Peter-John Wormald, Sarah Vreugd

    The risk of cancer in HIV-infected people in southeast England: a cohort study

    Get PDF
    This study used data from the Communicable Disease Surveillance Centre's national HIV database and the Thames Cancer Registry to assess the risk of cancer in HIV-infected people in southeast England. Among 26 080 HIV-infected men with 158 660 person-years follow-up, 1851 cancers, and among 7110 HIV-infected women (31 098 person-years), 171 cancers were identified. The standardised incidence ratio (SIR) for all non-AIDS-defining cancers was significantly increased in HIV-infected men (2.8, 95% confidence interval (CI) 2.6–3.1) but was nonsignificant in HIV-infected women (1.1, 95% CI 0.8–1.6). Most of the cancers observed were in men (n=1559) and women (n=127) with AIDS, and among them, the SIR for all non-AIDS-defining cancers was significantly increased in men (8.2, 95% CI 7.2–9.2) and women (2.8, 95% CI 1.6–4.6). The SIR for all non-AIDS-defining cancers was only just significantly increased in men with HIV-infection but not AIDS (1.2, 95% CI 1.0–1.5) and was nonsignificant in such women (0.8, 95% CI 0.5–1.2)

    Post-operative critical care management of patients undergoing cytoreductive surgery and heated intraperitoneal chemotherapy (HIPEC)

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Cytoreductive surgery (CRS) and Heated Intraperitoneal Chemotherapy (HIPEC) results in a number of physiological changes with effects on the cardiovascular system, oxygen consumption and coagulation. The Critical Care interventions required by this cohort of patients have not yet been quantified.</p> <p>Methods</p> <p>This retrospective audit examines the experience of a Specialist Tertiary Centre in England over an 18 month period (January 2009-June 2010) during which 69 patients underwent CRS and HIPEC. All patients were extubated in the operating theatre and transferred to the Critical Care Unit (CCU) for initial post-operative management.</p> <p>Results</p> <p>Patients needed to remain on the CCU for 2.4 days (0.8-7.8). There were no 30 day mortalities. The majority of patients (70.1%) did not require post-operative organ support. 2 patients who developed pneumonia post-operatively required respiratory support. 18 (26.1%) patients required vasopressor support with norepinephrine with a mean duration of 13.94 hours (5-51 hours) and mean dose of 0.04 mcg/kg/min. Post-operative coagulopathy peaked at 24 hours. A significant drop in serum albumin was observed.</p> <p>Conclusion</p> <p>The degree of organ support required post-operatively is minimal. Early extubation is efficacious with the aid of epidural analgesia. Critical Care monitoring for 48 hours is desirable in view of the post-operative challenges.</p

    Peginterferon Alfa-2a in Patients with Chronic Hepatitis C and Cirrhosis

    Get PDF
    Background Chronic hepatitis C virus (HCV) infection in patients with cirrhosis is difficult to treat. In patients with chronic hepatitis C but without cirrhosis, once-weekly administration of interferon modified by the attachment of a 40-kd branched-chain polyethylene glycol moiety (peginterferon alfa-2a) is more efficacious than a regimen of unmodified interferon. We examined the efficacy and safety of peginterferon alfa-2a in patients with HCV-related cirrhosis or bridging fibrosis. Methods We randomly assigned 271 patients with cirrhosis or bridging fibrosis to receive subcutaneous treatment with 3 million units of interferon alfa-2a three times weekly (88 patients), 90 µg of peginterferon alfa-2a once weekly (96), or 180 µg of peginterferon alfa-2a once weekly (87). Treatment lasted 48 weeks and was followed by a 24-week follow-up period. We assessed efficacy by measuring HCV RNA and alanine aminotransferase and by evaluating liverbiopsy specimens. A histologic response was defined as a decrease of at least 2 points on the 22-point Histological Activity Index. Results In an intention-to-treat analysis, HCV RNA was undetectable at week 72 in 8 percent, 15 percent, and 30 percent of the patients treated with interferon alfa-2a and with 90 µg and 180 µg of peginterferon alfa-2a, respectively (P=0.001 for the comparison between 180 µg of peginterferon alfa-2a and interferon alfa-2a). At week 72, alanine aminotransferase concentrations had normalized in 15 percent, 20 percent, and 34 percent of patients, respectively (P=0.004 for the comparison between 180 µg of peginterferon alfa-2a and interferon alfa-2a). In the subgroup of 184 patients with paired liver-biopsy specimens, the rates of histologic response at week 72 were 31 percent, 44 percent, and 54 percent, respectively (P=0.02 for the comparison between 180 µg of peginterferon alfa-2a and interferon alfa-2a). All three treatments were similarly tolerated. Conclusions In patients with chronic hepatitis C and cirrhosis or bridging fibrosis, 180 µg of peginterferon alfa-2a administered once weekly is significantly more effective than 3 million units of standard interferon alfa-2a administered three times weekly. (N Engl J Med 2000;343:1673-80.

    Prevention of adhesions post-abdominal surgery: Assessing the safety and efficacy of Chitogel with Deferiprone in a rat model

    Get PDF
    Introduction: Adhesions are often considered to be an inevitable consequence of abdominal and pelvic surgery, jeopardizing the medium and long-term success of these procedures. Numerous strategies have been tested to reduce adhesion formation, however, to date, no surgical or medical therapeutic approaches have been successful in its prevention. This study demonstrates the safety and efficacy of Chitogel with Deferiprone and/or antibacterial Gallium Protoporphyrin in different concentrations in preventing adhesion formation after abdominal surgery. Materials and Methods: DS: 112 adult (8-10 week old) male Wistar albino rats were subjected to midline laparotomy and caecal abrasion, with 48 rats having an additional enterotomy and suturing. Kaolin (0.005g/ml) was applied to further accelerate adhesion formation. The abrasion model rats were randomized to receive saline, Chitogel, or Chitogel plus Deferiprone (5, 10 or 20 mM), together with Gallium Protoporphyrin (250μg/mL). The abrasion with enterotomy rats were randomised to receive saline, Chitogel or Chitogel with Deferiprone (1 or 5 mM). At day 21, rats were euthanised, and adhesions graded macroscopically and microscopically; the tensile strength of the repaired caecum was determined by an investigator blinded to the treatment groups. Results: Chitogel with Deferiprone 5 mM significantly reduced adhesion formation (p<0.01) when pathologically assessed in a rat abrasion model. Chitogel with Deferiprone 5 mM and 1 mM also significantly reduced adhesions (p<0.05) after abrasion with enterotomy. Def-Chitogel 1mM treatment did not weaken the enterotomy site with treated sites having significantly better tensile strength compared to control saline treated enterotomy rats. Conclusions: Chitogel with Deferiprone 1 mM constitutes an effective preventative anti-adhesion barrier after abdominal surgery in a rat model. Moreover, this therapeutic combination of agents is safe and does not weaken the healing of the sutured enterotomy site.Rajan Sundaresan Vediappan, Catherine Bennett, Clare Cooksley, John Finnie, Markus Trochsler, Ryan D. Quarrington, Claire F. Jones, Ahmed Bassiouni, Stephen Moratti, Alkis J. Psaltis, Guy Maddern, Sarah Vreugde, P.J. Wormal

    The importance of baseline viral load when assessing relative efficacy in treatment-naïve HBeAg-positive chronic hepatitis B: a systematic review and network meta-analysis.

    Get PDF
    BACKGROUND: To date no network meta-analysis (NMA) has accounted for baseline variations in viral load when assessing the relative efficacy of interventions for chronic hepatitis B (CHB). We undertook baseline-adjusted and unadjusted analyses using the same data to explore the impact of baseline viral load (BVL) on CHB treatment response. METHODS: We searched Embase, Medline, Medline in Process and the Cochrane CENTRAL databases for randomised clinical trials (RCTs) of monotherapy interventions at licensed doses for use in CHB. Search strategies comprised CHB disease and drug terms (a combination of controlled vocabulary and free text terms) and also a bespoke RCT filter.The NMA was undertaken in WinBUGs using fixed and random effects methods, using data obtained from a systematic review. Individual patient data (IPD) from an entecavir clinical trial were used to quantify the impact of different baseline characteristics (in particular undetectable viral load (UVL) at 1 year) on relative treatment effect. Study level mean baseline values from all identified studies were used. Results were generated for UVL and presented as relative risks (RRs) and 95% credible intervals (CrIs) using entecavir as reference treatment. RESULTS: Overall, for all eight relevant interventions we identified 3,000 abstracts. Following full text review a total of 35 (including the contents of six clinical study reports) met the inclusion critera; 19 were in hepatitis B e antigen (HBeAg)-positive patients and 14 of the 19 contained outcome information of relevance to the NMA.Entecavir and tenofovir studies had heterogeneous patient populations in terms of BVL (mean values 9.29 and 8.65 log10 copies/ml respectively). After adjusting UVL for BVL using an informative prior based on the IPD analysis, the difference between entecavir and tenofovir was not statistically significant (RR 1.27, 95% CrI 0.96 to 1.47-fixed effects). A similar conclusion was found in all sensitivity analyses. Adjusted tenofovir results were more consistent with observed clinical trial response rates. CONCLUSIONS: This study demonstrates the importance of adjusting for BVL when assessing the relative efficacy of CHB interventions in achieving UVL. This has implications for both clinical and economic decision making
    corecore