498 research outputs found
Post-tuberculous fibrosing mediastinitis: a review of the literature.
Fibrosing mediastinitis (FM) is a rare disease where there is thickening of the fibrous tissue in the mediastinum. While histoplasmosis is the the most common recognised cause, the link with tuberculosis (TB) has been rarely documented. We review the link between TB and FM, and describe a case of probable TB-related FM.Our case is of a 74-year-old man who presented with breathlessness 3 years after fully treated TB. Scans revealed a calcified soft tissue mass within the mediastinum, and a diagnosis of fibrosing mediastinitis resulting in pulmonary hypertension was made. Tests for histoplasmosis and IgG4 staining were negative. Surgical intervention was not felt to be beneficial, and he was treated with prednisolone and mycophenolate mofetil.In the review, we highlight the two forms of mediastinitis-granulomatous versus fibrous, and how these two entities may be on a spectrum of disease progression. We also explore the prevalence, clinical presentation, pathogenesis, imaging techniques and treatment options of TB-related FM
Differential rotation measurement of soft X-Ray corona
The aim of this paper is to study the latitudinal variation in the solar
rotation in soft X-ray corona. The time series bins are formed on different
latitude regions of the solar full disk (SFD) images that extend from 80 degree
South to 80 degree North. These SFD images are obtained with the soft X-ray
telescope (SXT) on board the Yohkoh solar observatory. The autocorrelation
analyses are performed with the time series that track the SXR flux modulations
in the solar corona. Then for each year, extending from 1992 to 2001, we obtain
the coronal sidereal rotation rate as a function of the latitude. The present
analysis from SXR radiation reveals that; (i) the equatorial rotation rate of
the corona is comparable to the rotation rate of the photosphere and the
chromosphere, (ii) the differential profile with respect to the latitude varies
throughout the period of the study; it is more in the year 1999 and least in
1994 and (iii) the equatorial rotation period varies systematically with
sunspot numbers and indicates its dependence on the phases of the solar
activity cycle.Comment: 9 Pages, 4 Figures, Accepted for Publication in MNRA
Differential coronal rotation using radio images at 17 GHz
In the present work, we perform time-series analysis on the latitude bins of
the solar full disk (SFD) images of Nobeyama Radioheliograph (NoRH) at 17 GHz.
The flux modulation method traces the passage of radio features over the solar
disc and the autocorrelation analysis of the time-series data of SFD images
(one per day) for the period 1999-2001 gives the rotation period as a function
of latitude extending from 60 degree S to 60 degree N. The results show that
the solar corona rotates less differentially than the photosphere and
chromosphere, i.e., it has smaller gradient in the rotation rate.Comment: 5 pages, 5 figures, Accepted for publication in MNRAS letter
Periodicities in the coronal rotation and sunspot numbers
The present study is an attempt to investigate the long term variations in
coronal rotation by analyzing the time series of the solar radio emission data
at 2.8 GHz frequency for the period 1947 - 2009. Here, daily adjusted radio
flux (known as Penticton flux) data are used. The autocorrelation analysis
shows that the rotation period varies between 19.0 to 29.5 sidereal days (mean
sidereal rotation period is 24.3 days). This variation in the coronal rotation
period shows evidence of two components in the variation; (1) 22-years
component which may be related to the solar magnetic field reversal cycle or
Hale's cycle, and (3) a component which is irregular in nature, but dominates
over the other components. The crosscorrelation analysis between the annual
average sunspots number and the coronal rotation period also shows evidence of
its correlation with the 22-years Hale's cycle. The 22-years component is found
to be almost in phase with the corresponding periodicities in the variation of
the sunspots number.Comment: 9 pages, 5 figures, Accepted for publication in MNRA
Aqueous Neem Extract Versus Neem Powder on Culex quinquefasciatus: Implications for Control in Anthropogenic Habitats
Control programs using conventional insecticides to target anthropogenic mosquito habitats are very expensive because these habitats are widespread, particularly in cities of most African countries. Additionally, there are serious environmental concerns regarding large-scale application of most conventional insecticides. Clearly there is a need for alternative methods that are more effective, less expensive, and environmentally friendly. One such method would be the application of preparations made from parts of the neem tree, Azadirachta indica A. Jussieu (Sapindales: Meliaceae). In this study, aqueous crude extracts and crude powder were prepared from different parts of neem, and the efficacies of the preparations on juvenile stages of Culex quinquefasciatus Say (Diptera: Culicidae) were evaluated in the laboratory. When larvae were exposed to a concentration of 0.1 g/mL extract for 24 hours, percent mean mortality (± SE) was 72.7 plusmn; 1.8 for the bark, 68.7 ± 1.6 for fruits and 60 ± 1.6 for leaves. These means were not significantly different (χ2 = 4.12; df = 2; p = 0.127). At a concentration of 0.01 g/mL, > 95% of the larvae died within 24 hours of exposure to powdered neem leaf, but it took 120 hours to reach the same level of larval mortality in aqueous leaf extract. The crude extract slowly inhibited the growth and development of mosquitoes while the crude powder acted more as a barrier; the mosquitoes probably died from suffocation. However, both types of preparations can be made and used by local people to control mosquito breeding in anthropogenic habitats, especially in urbanized areas
Knowledge and malaria treatment practices using artemisinin combination therapy (ACT) in Malawi: survey of health professionals
<p>Abstract</p> <p>Background</p> <p>Malaria still remains a life-threatening disease worldwide causing between 190 and 311 million cases of malaria in 2008. Due to increased resistance to sulphadoxine-pyrimethamine (SP), the Ministry of Health in Malawi, as in many sub-Saharan African countries, changed the malaria treatment policy to use artemisinin-based combination therapy (ACT). In order to optimize the correct use of this drug, and protect against the development of the parasite's resistance, it is important to assess the knowledge and practices of medical practitioners on the use of ACT and its impact on adherence to new treatment policy guidelines.</p> <p>Methods</p> <p>A cross-sectional survey was conducted to assess the knowledge and perceptions of Malawian medical doctors and pharmacists on the use of ACT and the drivers of treatment choice and clinical treatment decisions. Medical doctors and pharmacists who are involved in managing malaria patients in Malawi were recruited and a self-administered questionnaire was used to obtain information on socio-demographic characteristics of the study participants, knowledge on ACT, source of information on ACT and methods used to decide on the treatment of patients with malaria.</p> <p>Results</p> <p>Most of the participants (95.7%) know at least one form of ACT, 67.4% reported that different forms of ACT have different characteristics, 77.3% reported that there are special formulations for children. The most commonly mentioned ACT was artemether-lumefantrine (AL), by 94.6% of the participants and 75.0% of the participants indicated that they prefer to prescribe AL. 73.9% of participants had ever received information on ACT. However, only 31.5% had received training on management of malaria using ACT. There were 71.7% respondents who had heard of ACT causing side effects. Only 25.0% of the participants had received training on how to report SAEs.</p> <p>Conclusion</p> <p>It was found that most of the participants know about ACT and treatment guidelines for malaria. However, most of the participants have not received any training on how to use ACT and how to report adverse effects arising from the use of ACT. There is need for more training of health care professionals to ensure correct and effective use of ACT.</p
Reproductive health for refugees by refugees in Guinea III: maternal health
BACKGROUND: Maternal mortality can be particularly high in conflict and chronic emergency settings, partly due to inaccessible maternal care. This paper examines associations of refugee-led health education, formal education, age, and parity on maternal knowledge, attitudes, and practices among reproductive-age women in refugee camps in Guinea. METHODS: Data comes from a 1999 cross-sectional survey of 444 female refugees in 23 camps. Associations of reported maternal health outcomes with exposure to health education (exposed versus unexposed), formal education (none versus some), age (adolescent versus adult), or parity (nulliparous, parous, grand multiparous), were analysed using logistic regression. RESULTS: No significant differences were found in maternal knowledge or attitudes. Virtually all respondents said pregnant women should attend antenatal care and knew the importance of tetanus vaccination. Most recognised abdominal pain (75%) and headaches (24%) as maternal danger signs and recommended facility attendance for danger signs. Most had last delivered at a facility (67%), mainly for safety reasons (99%). Higher odds of facility delivery were found for those exposed to RHG health education (adjusted odds ratio 2.03, 95%CI 1.23-3.01), formally educated (adjusted OR 1.93, 95%CI 1.05-3.92), or grand multipara (adjusted OR 2.13, 95%CI 1.21-3.75). Main reasons for delivering at home were distance to a facility (94%) and privacy (55%). CONCLUSIONS: Refugee-led maternal health education appeared to increase facility delivery for these refugee women. Improved knowledge of danger signs and the importance of skilled birth attendance, while vital, may be less important in chronic emergency settings than improving facility access where quality of care is acceptable
Physicochemical and Biological Evaluation of siRNA Polyplexes Based on PEGylated Poly(amido amine)s
PURPOSE: Use of RNA interference as novel therapeutic strategy is hampered by inefficient delivery of its mediator, siRNA, to target cells. Cationic polymers have been thoroughly investigated for this purpose but often display unfavorable characteristics for systemic administration, such as interactions with serum and/or toxicity. METHODS: We report the synthesis of a new PEGylated polymer based on biodegradable poly(amido amine)s with disulfide linkages in the backbone. Various amounts of PEGylated polymers were mixed with their unPEGylated counterparts prior to polyplex formation to alter PEG content in the final complex. RESULTS: PEGylation effectively decreased polyplex surface charge, salt- or serum-induced aggregation and interaction with erythrocytes. Increasing amount of PEG in formulation also reduced its stability against heparin displacement, cellular uptake and subsequent silencing efficiency. Yet, for polyplexes with high PEG content, significant gene silencing efficacy was found, which was combined with almost no toxicity. CONCLUSIONS: PEGylated poly(amido amine)s are promising carriers for systemic siRNA delivery in vivo
Limited duration of vaccine poliovirus and other enterovirus excretion among human immunodeficiency virus infected children in Kenya
<p>Abstract</p> <p>Background</p> <p>Immunodeficient persons with persistent vaccine-related poliovirus infection may serve as a potential reservoir for reintroduction of polioviruses after wild poliovirus eradication, posing a risk of their further circulation in inadequately immunized populations.</p> <p>Methods</p> <p>To estimate the potential for vaccine-related poliovirus persistence among HIV-infected persons, we studied poliovirus excretion following vaccination among children at an orphanage in Kenya. For 12 months after national immunization days, we collected serial stool specimens from orphanage residents aged <5 years at enrollment and recorded their HIV status and demographic, clinical, immunological, and immunization data. To detect and characterize isolated polioviruses and non-polio enteroviruses (NPEV), we used viral culture, typing and intratypic differentiation of isolates by PCR, ELISA, and nucleic acid sequencing. Long-term persistence was defined as shedding for ≥ 6 months.</p> <p>Results</p> <p>Twenty-four children (15 HIV-infected, 9 HIV-uninfected) were enrolled, and 255 specimens (170 from HIV-infected, 85 from HIV-uninfected) were collected. All HIV-infected children had mildly or moderately symptomatic HIV-disease and moderate-to-severe immunosuppression. Fifteen participants shed vaccine-related polioviruses, and 22 shed NPEV at some point during the study period. Of 46 poliovirus-positive specimens, 31 were from HIV-infected, and 15 from HIV-uninfected children. No participant shed polioviruses for ≥ 6 months. Genomic sequencing of poliovirus isolates did not reveal any genetic evidence of long-term shedding. There was no long-term shedding of NPEV.</p> <p>Conclusion</p> <p>The results indicate that mildly to moderately symptomatic HIV-infected children retain the ability to clear enteroviruses, including vaccine-related poliovirus. Larger studies are needed to confirm and generalize these findings.</p
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