573 research outputs found
Phagosome Escape of Rough Mycobacterium abscessus Strains in Murine Macrophage via Phagosomal Rupture Can Lead to Type I Interferon Production and Their Cell-To-Cell Spread
Mycobacterium abscessus complex (MAB) is a rapidly growing mycobacterium(RGM) whose clinical significance as an emerging human pathogen has been increasing worldwide. It has two types of colony morphology, a smooth (S) type, producing high glycopeptidolipid (GPL) content, and a rough (R) type, which produces low levels of GPLs and is associated with increased virulence. However, the mechanism responsible for their difference in virulence is poorly known. By ultrastructural examination of murine macrophages infected, we found that MAB-R strains could replicate more actively in the macrophage phagosome than the S variants and that they could escape into cytosol via phagosomal rupture. The cytosolic access of MAB-R strains via phagosomal rupture led to enhanced Type I interferon (IFN) production and cell death, which resulted in their cell-to-cell spreading. This behavior can provide an additional niche for the survival of MAB-R strains. In addition, we found that their enhancement of cell death mediated cell spreading are dependent on Type I IFN signaling via comparison of wild-type and IFNAR1 knockout mice. In conclusion, our data indicated that a transition of MAB-S strains into MAB-R variants increased their virulence via enhanced Type I IFN production, which led to enhanced survival in infected macrophage via cell death mediated cell-to-cell spreading. This result provides not only a novel insight into the difference in virulence between MAB-R and -S variants but also hints to their treatment strategy
A Case Report of Reiter's Syndrome with Progressive Myelopathy
Reiter's syndrome belongs to the family of spondyloarthropathies that usually present with a triad of arthritis, urethritis, and uveitis. The diagnostic criteria include clinical, radiological, and genetic findings, and the response to treatment. Nervous system involvement in Reiter's syndrome is extremely rare. We report here on a 36-year-old man who initially presented with progressive cervical myelopathy and was diagnosed as Reiter's syndrome 2 years later. The myelopathy was stable after treatment with methotrexate and sulfasalazine. This case suggests that Reiter's syndrome can present as progressive myelopathy and should be considered in the differential diagnosis of treatable myelopathies
SelecMix: Debiased Learning by Contradicting-pair Sampling
Neural networks trained with ERM (empirical risk minimization) sometimes
learn unintended decision rules, in particular when their training data is
biased, i.e., when training labels are strongly correlated with undesirable
features. To prevent a network from learning such features, recent methods
augment training data such that examples displaying spurious correlations
(i.e., bias-aligned examples) become a minority, whereas the other,
bias-conflicting examples become prevalent. However, these approaches are
sometimes difficult to train and scale to real-world data because they rely on
generative models or disentangled representations. We propose an alternative
based on mixup, a popular augmentation that creates convex combinations of
training examples. Our method, coined SelecMix, applies mixup to contradicting
pairs of examples, defined as showing either (i) the same label but dissimilar
biased features, or (ii) different labels but similar biased features.
Identifying such pairs requires comparing examples with respect to unknown
biased features. For this, we utilize an auxiliary contrastive model with the
popular heuristic that biased features are learned preferentially during
training. Experiments on standard benchmarks demonstrate the effectiveness of
the method, in particular when label noise complicates the identification of
bias-conflicting examples.Comment: NeurIPS 202
Comparison of Conventional Excision via a Sublabial Approach and Transnasal Marsupialization for the Treatment of Nasolabial Cysts: A Prospective Randomized Study
ObjectivesSurgical excision via a sublabial approach is considered the standard treatment for nasolabial cysts. Although transnasal marsupialization has been proposed as an alternative method, no prospective study has compared the effectiveness of these techniques. We thus compared the surgical procedure, operating time, postoperative pain, complications, and recurrence rate between the two surgical methods.MethodsTwenty patients diagnosed with nasolabial cysts were allocated randomly into two groups according to the surgical technique. In the sublabial approach group, the cysts were excised completely using a sublabial approach, while in the transnasal marsupialization group, the cysts were marsupialized transnasally under the guidance of nasal endoscopes. The pure operating time was measured and postoperative pain was evaluated using a visual analog scale. Complications after the procedure were assessed and recurrence was determined according to the clinical symptoms and postoperative radiologic findings.ResultsThe transnasal marsupialization group had significantly shorter operating times, less postoperative pain, lower complication rates, and shorter duration of side effects than the sublabial approach group. No recurrence occurred in either group after a 1-yr follow-up period.ConclusionAlthough both methods are effective for treating nasolabial cysts, the transnasal marsupialization of nasolabial cysts has many benefits over the conventional sublabial approach. Therefore, we propose that transnasal marsupialization be the treatment of choice for nasolabial cysts
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Atrophic Gastritis: A Related Factor for Osteoporosis in Elderly Women
Purpose Osteoporosis poses a great threat to the aging society. Hypochlorhydric or achlorhydric conditions are risk factors for osteoporosis. Atrophic gastritis also decreases gastric acid production; however, the role of atrophic gastritis as a related factor for osteoporosis is unclear. We investigated the relationship between atrophic gastritis and osteoporosis in postmenopausal women over 60 years of age. Subjects and Methods A total of 401 postmenopausal women were included in this cross-sectional study, which was conducted during their medical check-ups. Bone mineral densitometry was measured using a dual energy X-ray absorptiometry. Atrophic gastritis was defined endoscopically if gastric mucosa in the antrum and the body were found to be atrophied and thinned and submucosal vessels could be well visualized. Results: The proportion of people with atrophic gastritis was higher in the osteoporotic group than in the group without osteoporosis. A linear relationship was observed in the proportion of atrophic gastritis according to the categories of normal, osteopenia, and osteoporosis at the lumbar spine (p for trend = 0.039) and femur (p for trend = 0.001). A multiple logistic regression analysis revealed that the presence of atrophic gastritis was associated with an increased odds of osteoporosis after adjusting for age, body mass index, triglyceride, high-density lipoprotein cholesterol, alcohol consumption, and smoking status (odds ratio 1.89, 95% confidence interval 1.15–3.11). Conclusions: Atrophic gastritis is associated with an increased likelihood of osteoporosis in Korean elderly women
Rough colony morphology of Mycobacterium massiliense Type II genotype is due to the deletion of glycopeptidolipid locus within its genome
Background: Recently, we introduced the complete genome sequence of Mycobacterium massiliense clinical isolates, Asan 50594 belonging to Type II genotype with rough colony morphology. Here, to address the issue of whether the rough colony morphotype of M. massiliense Type II genotype is genetically determined or not, we compared polymorphisms of the glycopeptidolipid (GPL) gene locus between M. massiliense Type II Asan 50594 and other rapidly growing mycobacteria (RGM) strains via analysis of genome databases.Results: We found deletions of 10 genes (24.8 kb), in the GPL biosynthesis related gene cluster of Asan 50594 genome, but no deletions in those of other smooth RGMs. To check the presence of deletions of GPL biosynthesis related genes in Mycobacterium abscessus - complex strains, PCRs targeting 12 different GPL genes (10 genes deleted in Asan 50594 genome as well as 2 conserved genes) were applied into 76 clinical strains of the M. abscessus complex strains [54 strains (Type I: 33, and Type II: 21) of M. massiliense and 22 strains (rough morphoype: 11 and smooth morphotype: 11) of M. abscessus]. No strains of the Type II genotype produced PCR amplicons in a total of 10 deleted GPL genes, suggesting loss of GPL biosynthesis genes in the genome of M. massiliense type II genotype strains.Conclusions: Our data suggested that the rough colony morphotype of the M. massiliense Type II genotype may be acquired via deletion events at the GPL gene locus for evolutionary adaptation between the host and pathogen.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000006653/7SEQ:7PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000006653ADJUST_YN:YEMP_ID:A077651DEPT_CD:806CITE_RATE:4.397FILENAME:rough colony morphology of mycobacterium.pdfDEPT_NM:의과학과SCOPUS_YN:YCONFIRM:
Biological Profiles of Korean Atomic Bomb Survivors in Residence at Daegu and Kyungbuk, Republic of Korea
In 1945, many Koreans, in addition to Japanese, were killed or injured by the atomic bombs dropped on Hiroshima and Nagasaki, Japan. This study compared the biological profiles of Korean atomic bomb survivors in residence at Daegu and Kyungbuk, Republic of Korea with those of a representative sample of Koreans obtained during a similar period. We evaluated anthropometric measurements, blood pressure, blood cell counts, blood chemistry, and urinalysis of survivors (n=414) and age- and sex-matched controls (n=414) recruited from the third Korea National Health and Nutrition Examination Survey conducted in 2005. Univariate analyses revealed significantly higher systolic blood pressure, white blood cell count, and serum total cholesterol, triglycerides, high-density lipoprotein-cholesterol, and aspartate aminotransferase levels (p<0.01) in the survivors. Conversely, hemoglobin concentration, hematocrit, red blood cell count, and the proportion of positive urine occult blood (p<0.01) were lower in the survivors. Our findings suggest that biological profiles of Korean atomic bomb survivors were adversely affected by radiation exposure
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