310 research outputs found
Effect of different intravenous iron preparations on lymphocyte intracellular reactive oxygen species generation and subpopulation survival
<p>Abstract</p> <p>Background</p> <p>Infections in hemodialysis (HD) patients lead to high morbidity and mortality rates and are associated with early cardiovascular mortality, possibly related to chronic inflammation. Intravenous (IV) iron is widely administered to HD patients and has been associated with increased oxidative stress and dysfunctional cellular immunity. The purpose of this study was to examine the effect of three commercially available IV iron preparations on intracellular reactive oxygen species generation and lymphocyte subpopulation survival.</p> <p>Methods</p> <p>Peripheral blood mononuclear cells (PBMC) were isolated from healthy donor buffy coat. PBMC were cultured and incubated with 100 μg/mL of sodium ferric gluconate (SFG), iron sucrose (IS) or iron dextran (ID) for 24 hours. Cells were then probed for reactive oxygen species (ROS) with dichlorofluorescein-diacetate. In separate studies, isolated PBMCs were incubated with the 25, 50 or 100 μg/mL iron concentrations for 72 hours and then stained with fluorescein conjugated monoclonal antibodies for lymphocyte subpopulation identification. Untreated PBMCs at 24 hours and 72 hours served as controls for each experiment.</p> <p>Results</p> <p>All three IV iron preparations induced time dependent increases in intracellular ROS with SFG and IS having a greater maximal effect than ID. The CD4+ lymphocytes were most affected by IV iron exposure, with statistically significant reduction in survival after incubation with all three doses (10, 25 and 100 μg/mL) of SFG, IS and ID.</p> <p>Conclusion</p> <p>These data indicate IV iron products induce differential deleterious effects on CD4+ and CD16+ human lymphocytes cell populations that may be mediated by intracellular reactive oxygen species generation. Further studies are warranted to determine the potential clinical relevance of these findings.</p
Early and efficient detection of Mycobacterium tuberculosis in sputum by microscopic observation of broth cultures.
Early, efficient and inexpensive methods for the detection of pulmonary tuberculosis are urgently needed for effective patient management as well as to interrupt transmission. These methods to detect M. tuberculosis in a timely and affordable way are not yet widely available in resource-limited settings. In a developing-country setting, we prospectively evaluated two methods for culturing and detecting M. tuberculosis in sputum. Sputum samples were cultured in liquid assay (micro broth culture) in microplate wells and growth was detected by microscopic observation, or in Löwenstein-Jensen (LJ) solid media where growth was detected by visual inspection for colonies. Sputum samples were collected from 321 tuberculosis (TB) suspects attending Bugando Medical Centre, in Mwanza, Tanzania, and were cultured in parallel. Pulmonary tuberculosis cases were diagnosed using the American Thoracic Society diagnostic standards. There were a total of 200 (62.3%) pulmonary tuberculosis cases. Liquid assay with microscopic detection detected a significantly higher proportion of cases than LJ solid culture: 89.0% (95% confidence interval [CI], 84.7% to 93.3%) versus 77.0% (95% CI, 71.2% to 82.8%) (p = 0.0007). The median turn around time to diagnose tuberculosis was significantly shorter for micro broth culture than for the LJ solid culture, 9 days (interquartile range [IQR] 7-13), versus 21 days (IQR 14-28) (p<0.0001). The cost for micro broth culture (labor inclusive) in our study was US 11.35 per sample for the LJ solid culture. The liquid assay (micro broth culture) is an early, feasible, and inexpensive method for detection of pulmonary tuberculosis in resource limited settings
A three-year-old boy with X-linked adrenoleukodystrophy and congenital pulmonary adenomatoid malformation: a case report
Abstract
Introduction
X-linked adrenoleukodystrophy leads to demyelination of the nervous system, adrenal insufficiency, and accumulation of long-chain fatty acids. Most young patients with X-linked adrenoleukodystrophy develop seizures and progressive neurologic deficits, and die within the first two decades of life. Congenital or acquired disorders of the respiratory system have not been previously described in patients with X-linked adrenoleukodystrophy.
Case presentation
A 3-year-old Arabic boy from Yemen presented with discoloration of the mucous membranes and nail beds, which were considered cyanoses due to methemoglobinemia. He also had shortness of breath, fatigue, emesis and dehydration episodes for which he was admitted to our hospital. Chest radiograph and chest computed tomography scans showed congenital pulmonary adenomatoid malformation. A few weeks before the removal of the malformation, he had a significant episode of hypotension and hypoglycemia. This development required further in-hospital evaluation that led to the diagnosis of adrenal insufficiency and the initiation of treatment with corticosteroids. One year later, he developed seizures and loss of consciousness. Magnetic resonance imaging of his head showed diffuse demyelination secondary to X-linked adrenoleukodystrophy. He was treated with anti-seizure and anti-oxidants, and was referred for bone marrow transplant evaluation.
Conclusion
The presence of adrenal insufficiency, neurologic deficits and seizures are common manifestations of X-linked adrenoleukodystrophy. The association of congenital lung disease with X-linked adrenoleukodystrophy or Addison\u27s disease has not been described previously
Improving T-Cell Assays for the Diagnosis of Latent TB Infection: Potential of a Diagnostic Test Based on IP-10
Background
There is a need for simple tools such as the M.tuberculosis specific IFN-γ release assays (IGRA) to improve diagnosis of M.tuberculosis-infection in children. The aim of the study was to evaluate the performance of an IP-10 and IL-2 based tests for the diagnosis of M.tuberculosis-infection in recently exposed children from Nigeria.
Methodology and Principal Findings
Samples were obtained from 59 children at high risk of infection with M.tuberculosis (contacts of adults with smear and culture-positive tuberculosis) and 61 at low risk (contacts of smear-negative/culture-positive tuberculosis or community controls). IP-10 and IL-2 was measured in plasma after stimulation of whole-blood with M.tuberculosis specific antigens and mitogen. Previously developed criteria for positive IP-10 and IL-2 tests were used and the diagnostic performances of the IP-10 and IL-2 tests were compared with the Quantiferon In-Tube (QFT-IT) and the Tuberculin Skin Tests (TST). In response to M.tuberculosis specific antigens, the high-risk children expressed significantly higher levels of IP-10 (1358 pg/ml[IQR 278–2535 pg/ml]) and IL-2 (164 pg/ml[11–590 pg/ml]) than low risk groups 149 pg/ml(25–497 pg/ml), and 0 pg/ml(0–3 pg/ml), respectively. There was excellent agreement (>89%,k>0.80) between IP-10, IL-2 tests and QFT-IT, better than with TST (>74%,k>0.49). The IP-10 and IL-2 responses were strongly associated with M.tuberculosis exposure and with grade of infectiousness of the index cases (p<0.0001). IP-10, IL-2, and TST but not QFT-IT was associated with age of the child in the low risk groups (p<0.02).
Conclusions/Significance
IP-10 is expressed in high levels and results of the IP-10 test were comparable to the QFT-IT. IL-2 was released in low amounts in response to the antigens and not in response to the mitogen therefore IL-2 seems a less useful marker. We have demonstrated that IP-10 and possibly IL-2 could be alternative or adjunct markers to IFN-γ in the diagnosis infection with M.tuberculosis
Early-infantile onset epilepsy and developmental delay caused by bi-allelic GAD1 variants
Gamma-aminobutyric acid (GABA) and glutamate are the most abundant amino acid neurotransmitters in the brain. GABA, an inhibitory neurotransmitter, is synthesized by glutamic acid decarboxylase (GAD). Its predominant isoform GAD67, contributes up to ∼90% of base-level GABA in the CNS, and is encoded by the GAD1 gene. Disruption of GAD1 results in an imbalance of inhibitory and excitatory neurotransmitters, and as Gad1−/− mice die neonatally of severe cleft palate, it has not been possible to determine any potential neurological dysfunction. Furthermore, little is known about the consequence of GAD1 disruption in humans. Here we present six affected individuals from six unrelated families, carrying bi-allelic GAD1 variants, presenting with developmental and epileptic encephalopathy, characterized by early-infantile onset epilepsy and hypotonia with additional variable non-CNS manifestations such as skeletal abnormalities, dysmorphic features and cleft palate. Our findings highlight an important role for GAD1 in seizure induction, neuronal and extraneuronal development, and introduce GAD1 as a new gene associated with developmental and epileptic encephalopathy
Tribological Analysis of Copper-Coated Graphite Particle-Reinforced A359 Al/5 wt.% SiC Composites
[[abstract]]Copper-coated graphite particles can be mass-produced by the cementation process using simple equipment.
Graphite particulates that were coated with electroless copper and 5 wt.% SiC particulates were
introduced into an aluminum alloy by compocasting to make A359 Al/5 wt.% SiC(p) composite that
contained 2, 4, 6, and 8 wt.% graphite particulate composite. The effects of SiC particles, quantity of
graphite particles, normal loading, sliding speed and wear debris on the coefficient of friction, and the wear
rate were investigated. The results thus obtained indicate that the wear properties were improved by adding
small amounts of SiC and graphite particles into the A359 Al alloy. The coefficient of friction of the A359
Al/5 wt.% SiC(p) composite that contained 6.0 wt.% graphite particulates was reduced to 0.246 and the
amount of graphite film that was released on the worn surface increased with the graphite particulate
content. The coefficient of friction and the wear rate were insensitive to the variation in the sliding speed
and normal loading.[[notice]]補正完畢[[incitationindex]]SCI[[booktype]]紙本[[booktype]]電子
Monophasic synovial sarcoma presenting as a primary ileal mass: a case report and review of the literature
<p>Abstract</p> <p>Introduction</p> <p>Synovial sarcoma is a rare malignant mesenchymal tumor mainly arising in the peri-articular tissue in young adults. There are few cases reported in other areas.</p> <p>Case presentation</p> <p>We report the case of a 29-year-old Saudi woman of Arabian ethnicity with synovial sarcoma arising primarily from the ileum who presented with abdominal pain, a palpable mass and incomplete intestinal obstruction. A literature review was performed to gather information on this rare gastrointestinal tract sarcoma.</p> <p>Conclusions</p> <p>Although it is a rare tumor of the pre-articular tissues, synovial sarcoma can present, in exceedingly rare cases, in unusual anatomical sites such as the gastrointestinal tract. We believe the reporting of all rare or unexpected presentations of sarcoma will eventually improve our understanding of this relatively unusual malignancy.</p
Culture Conversion Among HIV Co-Infected Multidrug-Resistant Tuberculosis Patients in Tugela Ferry, South Africa
Little is known about the time to sputum culture conversion in MDR-TB patients co-infected with HIV, although such patients have, historically, had poor outcomes. We describe culture conversion rates among MDR-TB patients with and without HIV-co-infection in a TB-endemic, high-HIV prevalent, resource-limited setting.Patients with culture-proven MDR-TB were treated with a standardized second-line regimen. Sputum cultures were taken monthly and conversion was defined as two negative cultures taken at least one month apart. Time-to-conversion was measured from the day of initiation of MDR-TB therapy. Subjects with HIV received antiretroviral therapy (ART) regardless of CD4 count.Among 45 MDR-TB patients, 36 (80%) were HIV-co-infected. Overall, 40 (89%) of the 45 patients culture-converted within the first six months and there was no difference in the proportion who converted based on HIV status. Median time-to-conversion was 62 days (IQR 48-111). Among the five patients who did not culture convert, three died, one was transferred to another facility, and one refused further treatment before completing 6 months of therapy. Thus, no patients remained persistently culture-positive at 6 months of therapy.With concurrent second-line TB and ART medications, MDR-TB/HIV co-infected patients can achieve culture conversion rates and times similar to those reported from HIV-negative patients worldwide. Future studies are needed to examine whether similar cure rates are achieved at the end of MDR-TB treatment and to determine the optimal use and timing of ART in the setting of MDR-TB treatment
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