MHD models of Pulsar Wind Nebulae

Pulsar Wind Nebulae (PWNe) are bubbles or relativistic plasma that form when the pulsar wind is confined by the SNR or the ISM. Recent observations have shown a richness of emission features that has driven a renewed interest in the theoretical modeling of these objects. In recent years a MHD paradigm has been developed, capable of reproducing almost all of the observed properties of PWNe, shedding new light on many old issues. Given that PWNe are perhaps the nearest systems where processes related to relativistic dynamics can be investigated with high accuracy, a reliable model of their behavior is paramount for a correct understanding of high energy astrophysics in general. I will review the present status of MHD models: what are the key ingredients, their successes, and open questions that still need further investigation.Comment: 18 pages, 5 figures, Invited Review, Proceedings of the "ICREA Workshop on The High-Energy Emission from Pulsars and their Systems", Sant Cugat, Spain, April 12-16, 201

The Faces in Infant-Perspective Scenes Change over the First Year of Life

Mature face perception has its origins in the face experiences of infants. However, little is known about the basic statistics of faces in early visual environments. We used head cameras to capture and analyze over 72,000 infant-perspective scenes from 22 infants aged 1-11 months as they engaged in daily activities. The frequency of faces in these scenes declined markedly with age: for the youngest infants, faces were present 15 minutes in every waking hour but only 5 minutes for the oldest infants. In general, the available faces were well characterized by three properties: (1) they belonged to relatively few individuals; (2) they were close and visually large; and (3) they presented views showing both eyes. These three properties most strongly characterized the face corpora of our youngest infants and constitute environmental constraints on the early development of the visual system

Buses, cars, bicycles and walkers the influence of the type of human transport on the flight responses of waterbirds

One way to manage disturbance to waterbirds in natural areas where humans require access is to promote the occurrence of stimuli for which birds tolerate closer approaches, and so cause fewer responses. We conducted 730 experimental approaches to 39 species of waterbird, using five stimulus types (single walker, three walkers, bicycle, car and bus) selected to mimic different human management options available for a controlled access, Ramsar-listed wetland. Across species, where differences existed (56% of 25 cases), motor vehicles always evoked shorter flight-initiation distances (FID) than humans on foot. The influence of stimulus type on FID varied across four species for which enough data were available for complete cross-stimulus analysis. All four varied FID in relation to stimuli, differing in 4 to 7 of 10 possible comparisons. Where differences occurred, the effect size was generally modest, suggesting that managing stimulus type (e.g. by requiring people to use vehicles) may have species-specific, modest benefits, at least for the waterbirds we studied. However, different stimulus types have different capacities to reduce the frequency of disturbance (i.e. by carrying more people) and vary in their capacity to travel around important habita

Clinical features, predictive factors and outcome of hyperglycaemic emergencies in a developing country

<p>Abstract</p> <p>Background</p> <p>Hyperglycaemic emergencies are common acute complications of diabetes mellitus (DM) but unfortunately, there is a dearth of published data on this entity from Nigeria. This study attempts to describe the clinical and laboratory scenario associated with this complication of DM.</p> <p>Methods</p> <p>This study was carried out in DM patients who presented to an urban hospital in Nigeria with hyperglycaemic emergencies (HEs). The information extracted included biodata, laboratory data and hospitalization outcome. Outcome measures included mortality rates, case fatality rates and predictive factors for HEs mortality. Statistical tests used are <it>χ</it>², Student's t test and logistic regression.</p> <p>Results</p> <p>A total of 111 subjects with HEs were recruited for the study. Diabetes ketoacidosis (DKA) and hyperosomolar hyperglycaemic state (HHS) accounted for 94 (85%) and 17 (15%) respectively of the HEs. The mean age (SD) of the subjects was 53.9 (14.4) years and their ages ranged from 22 to 86 years. DKA occurred in all subjects with type 1 DM and 73 (81%) of subjects with type 2 DM. The presence of HSS was noted in 17 (19%) of the subjects with type 2 DM.</p> <p>Hypokalaemia (HK) was documented in 41 (37%) of the study subjects. Elevated urea levels and hyponatraemia were noted more in subjects with DKA than in those subjects with HHS (57.5%,19% vs 53%,18%). The mortality rate for HEs in this report is 20% and the case fatality rates for DKA and HHS are 18% and 35% respectively.</p> <p>The predictive factors for HEs mortality include, sepsis, foot ulceration, previously undetected DM, hypokalaemia and being elderly.</p> <p>Conclusion</p> <p>HHS carry a higher case fatality rate than DKA and the predictive factors for hyperglycaemic emergencies' mortality in the Nigerian with DM include foot ulcers, hypokalaemia and being elderly.</p

Management of Patients With Refractory Reflux-Like Symptoms Despite Proton Pump Inhibitor Therapy: Evidence-Based Consensus Statements

\ua9 2024 The Author(s). Alimentary Pharmacology &amp; Therapeutics published by John Wiley &amp; Sons Ltd.Background: Many patients diagnosed with gastro-oesophageal reflux disease (GERD) have persistent symptoms despite proton pump inhibitor (PPI) therapy. Aims: The aim of this consensus is to provide evidence-based statements to guide clinicians caring for patients with refractory reflux-like symptoms (rRLS) or refractory GERD. Methods: This consensus was developed by the International Working Group for the Classification of Oesophagitis. The steering committee developed specific PICO questions pertaining to the management of PPI rRLS. Methodologists conducted systematic reviews of the literature. The quality of evidence and strength of recommendations were rated using the GRADE approach. Results: Consensus was reached on 13 of 17 statements on diagnosis and management. For rRLS, suggested diagnostic strategies included endoscopy, ambulatory reflux testing and oesophageal manometry. The group did not reach consensus on the role of oesophageal biopsies or the use of reflux-symptom association in patients undergoing reflux testing. The group suggested against increasing the PPI dose in patients who had received 8 weeks of a twice-daily PPI. Adjunctive alginate or antacid therapy was suggested. There was no consensus on the role of adjunctive prokinetics. There was little role for adjunctive transient lower oesophageal sphincter relaxation (TLESR) inhibitors or bile acid sequestrants. Endoscopic or surgical anti-reflux procedures should not be performed in patients with rRLS in the absence of objectively confirmed GERD. Conclusions: The management of rRLS should be personalised, based on shared decision-making regarding the role of diagnostic testing to confirm or rule out GERD as a basis for treatment optimisation. Anti-reflux procedures should not be performed without objective confirmation of GERD

Hepatitis B virus variants in an HIV-HBV co-infected patient at different periods of antiretroviral treatment with and without lamivudine

BACKGROUND: Lamivudine inhibits replication of both human immunodeficiency virus (HIV) and hepatitis B virus (HBV) and is commonly used as part of antiretroviral therapy. The main limitation in the use of lamivudine is resistant mutation selection. Most of these mutations affect the YMDD motif of the HBV DNA polymerase. The resistance occurs through M550V or M550I aminoacid replacements. The M550V variation may be accompanied by L526M mutation, notably in HIV-HBV co-infected patients. The aim of this study was to investigate mutations associated with lamivudine resistance in a hemodialysis patient chronically co-infected with HIV-1 and HBV, who was submitted to several antiretroviral treatments. METHODS: HBV isolates derived from three blood samples collected at different times of antiretroviral therapies with and without lamivudine, were titred and submitted to nucleotide sequencing. RESULTS: HBV isolate derived from a sample collected in 1999 during an antiretroviral treatment with lamivudine showed the lamivudine resistant double mutation (L526M, M550V). However, no mutation associated with lamivudine resistance was observed in the HBV genome derived from the sample collected during a period of treatment without lamivudine (2001). After reinstitution of lamivudine (2002), the predominant HBV population exhibited a rare triple mutation (V519L, L526M, M550V), which has previously been associated with an in vitro reduction of virus antigenicity (escape mutant). HBV DNA was detected at high levels (10(8)–10(9 )copies/ml) in the three blood samples. CONCLUSIONS: Reintroduction of lamivudine as part of antiretroviral treatment in a patient who had developed lamivudine resistant HBV strains favored the predominance of an HBV isolate with reduced antigenicity. The absence of hepatitis acute exacerbation in this patient may be correlated to the absence of significant variations of the viral load, which was independent of the presence of mutations in the HBV DNA polymerase

Current Antiviral Therapy of Chronic Hepatitis B: Efficacy and Safety

The treatment of chronic hepatitis B is in constant evolution. Interferon, the first agent licensed for chronic hepatitis B treatment, has been superseded by the growing popularity of nucleoside/nucleotide analogues (NA). However, resistance to these agents is a major challenge. Newer NAs, such as entecavir and tenofovir dipivoxil fumarate, have very low resistance rates and favorable safety profiles. Long-term use of these agents can effectively suppress hepatitis B virus DNA, leading to decrease in incidence of hepatitic flares, as well as in the development of cirrhosis and hepatocellular carcinoma. The efficacy and safety of various antiviral agents is discussed in this review

Therapeutic implications of an enriched cancer stem-like cell population in a human osteosarcoma cell line

<p>Abstract</p> <p>Background</p> <p>Osteosarcoma is a bone-forming tumor of mesenchymal origin that presents a clinical pattern that is consistent with the cancer stem cell model. Cells with stem-like properties (CSCs) have been identified in several tumors and hypothesized as the responsible for the relative resistance to therapy and tumor relapses. In this study, we aimed to identify and characterize CSCs populations in a human osteosarcoma cell line and to explore their role in the responsiveness to conventional therapies.</p> <p>Methods</p> <p>CSCs were isolated from the human MNNG/HOS cell line using the sphere formation assay and characterized in terms of self-renewal, mesenchymal stem cell properties, expression of pluripotency markers and ABC transporters, metabolic activity and tumorigenicity. Cell's sensitivity to conventional chemotherapeutic agents and to irradiation was analyzed and related with cell cycle-induced alterations and apoptosis.</p> <p>Results</p> <p>The isolated CSCs were found to possess self-renewal and multipotential differentiation capabilities, express markers of pluripotent embryonic stem cells Oct4 and Nanog and the ABC transporters P-glycoprotein and BCRP, exhibit low metabolic activity and induce tumors in athymic mice. Compared with parental MNNG/HOS cells, CSCs were relatively more resistant to both chemotherapy and irradiation. None of the treatments have induced significant cell-cycle alterations and apoptosis in CSCs.</p> <p>Conclusions</p> <p>MNNG/HOS osteosarcoma cells contain a stem-like cell population relatively resistant to conventional chemotherapeutic agents and irradiation. This resistant phenotype appears to be related with some stem features, namely the high expression of the drug efflux transporters P-glycoprotein and BCRP and their quiescent nature, which may provide a biological basis for resistance to therapy and recurrence commonly observed in osteosarcoma.</p

A study of chronic pelvic pain after radiotherapy in survivors of locally advanced cervical cancer

Introduction: Chronic pelvic pain (persisting pain in hips, groins or lower back) is poorly described in studies of cervical cancer survivors (CCSs). The aims of this study were to describe chronic pelvic pain and associated variables in CCSs surveyed >5 years post-radiotherapy, and to compare the presence of pain in hips and lower back in CCSs with findings in the general female population. Methods: Ninety-one CCSs treated with radiotherapy between 1994 and 1999 were in 2005 included in a cross-sectional questionnaire-based study. They were asked about demographic variables, clinical symptoms, mental distress, and quality of life (QOL). Normative data (NORM) were collected from a population-study of Norwegian females. Results: Pain in lower back and hips was significantly more prevalent (p < .001) in CCSs compared to NORMs. 35/92 (38%) of the CCSs had chronic pelvic pain. These women had significantly lower QOL, higher levels of anxiety and depression and more bladder and intestinal problems than those without chronic pelvic pain. In a multivariable regression model, use of analgesics and intestinal and bladder problems were significantly associated with chronic pelvic pain in the CCSs. Conclusions: CCSs have a higher prevalence of pain in lower back and hips than women in the general population, which might be due to late effects of radiation. 35/92 (38%) of the CCSs suffer from chronic pelvic pain, shown to be associated with high overall mental and somatic morbidity. Implications for Cancer Survivors: Evaluation and management of pelvic pain is important in follow-up of CCSs treated with radiotherapy

The methodological quality of systematic reviews comparing temporomandibular joint disorder surgical and non-surgical treatment

<p>Abstract</p> <p>Background</p> <p>Temporomandibular joint disorders (TMJD) are multifactor, complex clinical problems affecting approximately 60–70% of the general population, with considerable controversy about the most effective treatment. For example, reports claim success rates of 70% and 83% for non-surgical and surgical treatment, whereas other reports claim success rates of 40% to 70% for self-improvement without treatment. Therefore, the purpose of this study was to (1) identify systematic reviews comparing temporomandibular joint disorder surgical and non-surgical treatment, (2) evaluate their methodological quality, and (3) evaluate the evidence grade within the systematic reviews.</p> <p>Methods</p> <p>A search strategy was developed and implemented for MEDLINE, Cochrane Library, LILACS, and Brazilian Dentistry Bibliography databases. Inclusion criteria were: systematic reviews (± meta-analysis) comparing surgical and non-surgical TMJD treatment, published in English, Spanish, Portuguese, Italian, or German between the years 1966 and 2007(up to July). Exclusion criteria were: <it>in vitro </it>or animal studies; narrative reviews or editorials or editorial letters; and articles published in other languages. Two investigators independently selected and evaluated systematic reviews. Three different instruments (AMSTAR, OQAQ and CASP) were used to evaluate methodological quality, and the results averaged. The GRADE instrument was used to evaluate the evidence grade within the reviews.</p> <p>Results</p> <p>The search strategy identified 211 reports; of which 2 were systematic reviews meeting inclusion criteria. The first review met 23.5 ± 6.0% and the second met 77.5 ± 12.8% of the methodological quality criteria (mean ± sd). In these systematic reviews between 9 and 15% of the trials were graded as high quality, and 2 and 8% of the total number of patients were involved in these studies.</p> <p>Conclusion</p> <p>The results indicate that in spite of the widespread impact of TMJD, and the multitude of potential interventions, clinicians have expended sparse attention to systematically implementing clinical trial methodology that would improve validity and reliability of outcome measures. With some 20 years of knowledge of evidence-based healthcare, the meager attention to these issues begins to raise ethical issues about TMJD trial conduct and clinical care.</p