56 research outputs found
HIV-exposed infants with acute respiratory failure secondary to acute lower respiratory infections managed with and without mechanical ventilation
Objectives. The decision to provide mechanical ventilation (intermittent positive pressure ventilation (IPPV)) to HIV-exposed infants in resource-poor settings has remained difficult owing to problems in confirming HIV infection and the lack of data on outcome. We evaluated the predictive value of the HIV antibody test in confirming infection in infants requiring mechanical ventilation for acute lower respiratory infections (ALRis), and compared the outcome for children denied access with the outcome for similar subjects who were ventilated.Setting and design. This investigative study was conducted over a 12-month period at the paediatric intensive care unit (PICU) at King Edward VIII Hospital (KEH) in Durban, and at Ngwelezana Hospital in northern KwaZulu-Natal.Subjects. HIV-exposed patients with acute respiratory failure (ARF) secondary to ALRI entering the PICU at KEH were enrolled into the IPPV arm, while similar children who were refused such care at Ngwelezana Hospital were admitted into the non-IPPV arm. Standardised protocols for entry and management of enrolled subjects were utilised.Outcome measures. HIV DNA polymerase chain reaction (PCR) testing was performed to establish HIV status. Clinical and laboratory parameters were correlated with HIV status to determine predictors of infection and outcome (survival to discharge).Results. One hundred and sixteen HIV-exposed infants were enrolled, 49 into the IPPV arm and 67 into the non-IPPV arm. The median age of both groups was 3.0 months (0.5 - 11 months), and the male/female ratio and proportion of infants under 3 months of age were similar in both groups. The predictive values of the HIV antibody test in determining HIV infection in the IPPV and non-IPPV arms were 87.8% and 85.0% respectively. Splenomegaly and a serum globulin of >35 g/l increased the likelihood of being HIV PCR- positive (p = 0.006 and p = 0.04 respectively). Survival to discharge rates for HIV-infected children in the IPPV and non-IPPV arms were 41.9% and 24.6% respectively (p = 0.08). Age less than 3 months (p = 0.04) and very severe pneumonia (p = 0.007) were the only indicators of poor outcome.Conclusion. Mechanical ventilation provided little benefit in HIV-infected children with ARF from ALRI. An HIV antibody test in infants with ALRI and ARF is highly suggestive of HIV infection. Splenomegaly and a serumglobulin of greater than 35 g/l were the only useful markers in identifying HIV infection
Experimental transmission of jaagsiekte (ovine pulmonary adenomatosis) to goats
Jaagsiekte was successfully transmitted to at least 2 out of 6 goats inoculated intratracheally with partially purified jaagsiekte retrovirus. Multiple, small, well circumscribed nodules found in the lungs consisted of typical papilliform proliferations of neoplastic Type II epithelial cells. Histological evidence of a mild interstitial pneumonia in 4 of the experimental animals can probably be attibuted to a contaminating lentivirus in the jaagsiekte retrovirus preparation, as suggested by the seroconversion of the animals.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201
Isolation and preliminary characterization of the jaagsiekte retrovirus (JSRV)
Jaagsiekte, or ovine pulmonary adenomatosis, is caused by a recently discovered retrovirus. The virus cannot be cultivated in vitro at present, but a procedure is described for the isolation and purification of small amounts in the form of immune complexes with IgA from affected lungs. The virion was shown to possess a 70S RNA genome which can be transcribed by an endogenous reverse transcriptase. Nine polypeptides, ranging in
size from 94 000 to 25 000 daltons, were found in purified preparations. Using neutralization of the viral reverse transcriptase and an enzyme immunoassay as criteria, no serological relationship could be demonstrated to representatives of type B, C and C oncoviruses, or to bovine leukemia virus, maedi-visna virus of sheep or caprine arthritis-encephalitis virus.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format
The possible involvement of immunosuppression caused by a lentivirus in the aetiology of jaagsiekte and pasteurellosis in sheep
A South African isolate of ovine lentivirus was shown to cause a mild immunosuppression in sheep, reflected by a reduced delayed hypersensitivity reaction. This effect, measured in terms of skin swelling after intradermal inoculation with tuberculin, showed a positive linear relationship with the latency period before the appearance of jaagsiekte symptoms in animals co-infected with JSRV, as well as with the activity of monocytes. In a parallel study, increased susceptibility of lentivirus-infected sheep to infection with Pasteurella haemolytica was demonstrated. It is concluded that the lentivirus may play an enhancing role in both viral and bacterial infections of sheep by compromising the host's cellular immune response.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201
Isolation and identification of a South African lentivirus from jaagsiekte lungs
In the course of attempts to grow the jaagsiekte retrovirus in cell culture, a typical lentivirus was isolated for the first time in South Africa from adenomatous lungs. Morphologically the virus could not be distinguished from other lentiviruses, but serologically it was shown to be more closely related to visna virus than to caprine arthritis-encephalitis virus. However, a preliminary restriction enzyme analysis of the linear proviral DNA of this new lentivirus (SA-DMVV) revealed that it is significantly district from visna virus and CAEV and therefore may represent a third type of lentivirus. Antibodies to the virus were demonstrated in a number of sheep in various parts of the country, but a direct link to a disease condition was not found. Attempts to produce lung lesions by
intratracheal injection of the virus have been unsuccessful to date but a transient arthritis was produced by intra-articular inoculation. Viral replication seems to be enhanced in jaagsiekte lungs.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
Automated Classification of Sloan Digital Sky Survey (SDSS) Stellar Spectra using Artificial Neural Networks
Automated techniques have been developed to automate the process of
classification of objects or their analysis. The large datasets provided by
upcoming spectroscopic surveys with dedicated telescopes urges scientists to
use these automated techniques for analysis of such large datasets which are
now available to the community. Sloan Digital Sky Survey (SDSS) is one of such
surveys releasing massive datasets. We use Probabilistic Neural Network (PNN)
for automatic classification of about 5000 SDSS spectra into 158 spectral type
of a reference library ranging from O type to M type stars.Comment: 27 pages, 11 figures To appear in Astrophys. Space Sci., 200
Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV
Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7ââfbâ1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale
Altered white matter microstructural organization in posttraumatic stress disorder across 3047 adults: results from the PGC-ENIGMA PTSD consortium
A growing number of studies have examined alterations in white matter organization in people with posttraumatic stress disorder (PTSD) using diffusion MRI (dMRI), but the results have been mixed which may be partially due to relatively small sample sizes among studies. Altered structural connectivity may be both a neurobiological vulnerability for, and a result of, PTSD. In an effort to find reliable effects, we present a multi-cohort analysis of dMRI metrics across 3047 individuals from 28 cohorts currently participating in the PGC-ENIGMA PTSD working group (a joint partnership between the Psychiatric Genomics Consortium and the Enhancing NeuroImaging Genetics through Meta-Analysis consortium). Comparing regional white matter metrics across the full brain in 1426 individuals with PTSD and 1621 controls (2174 males/873 females) between ages 18-83, 92% of whom were trauma-exposed, we report associations between PTSD and disrupted white matter organization measured by lower fractional anisotropy (FA) in the tapetum region of the corpus callosum (Cohen's d = -0.11, p = 0.0055). The tapetum connects the left and right hippocampus, for which structure and function have been consistently implicated in PTSD. Results were consistent even after accounting for the effects of multiple potentially confounding variables: childhood trauma exposure, comorbid depression, history of traumatic brain injury, current alcohol abuse or dependence, and current use of psychotropic medications. Our results show that PTSD may be associated with alterations in the broader hippocampal network.New methods for child psychiatric diagnosis and treatment outcome evaluatio
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