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1.
Matrix metalloproteinases (MMPs) degrade basement membranes and connective tissue and play an essential role in the homeostasis of the extracellular matrix which is disrupted by the deposition of amyloid. This immunohistochemical study investigated the distribution pattern of matrix metalloproteinases (MMP-1, -2, -3, and -9) and their inhibitors [alpha 2-macroglobulin (alpha 2-M), tissue inhibitors of MMPs (TIMP)-1, and TIMP-2] in human AA- and AL amyloid deposits. Specimens of liver, kidney, and spleen from 22 autopsy cases were investigated. Nine patients had suffered from generalized AA amyloidosis, eight from generalized AL amyloidosis, and five from rheumatoid arthritis or tuberculosis with no histological evidence of amyloid. In all amyloidotic and non-amyloidotic patients, each protease and protease inhibitor was detected in almost every organ investigated. In the amyloidotic cases, there was no indication that a specific protease or protease inhibitor was absent or expressed, but a difference was observed in their spatial distribution patterns. The most noticeable difference was found in immunostaining of amyloid. Only MMP-1, -2, and -3, and alpha 2-M were present in AA amyloid deposits, and only TIMP-1 and TIMP-2 were found in deposits of AL amyloid. This is the first study to show that MMP-1, -2, and -3 are present in AA amyloid deposits. They may be involved in tissue remodeling or in proteolysis of the precursor and fibril proteins.  相似文献   

2.
Vibrio vulnificus is an estuarine bacterium capable of causing serious and often fatal wound infections and primary septicemia. We used alkaline phosphatase insertion mutagenesis to identify genes necessary for the virulence of this pathogen. One mutant had an in-frame fusion of ′phoA to the gene encoding RseB, a periplasmic negative regulator of the alternative sigma factor σE. σE controls an extensive regulon involved in responding to cell envelope stresses. Colonies of the rseB mutant were less opaque than wild-type colonies and underwent phase variation between translucent and opaque morphologies. rseB mutants were attenuated for virulence in subcutaneously inoculated iron-dextran-treated mice. To obtain insight into the role of rseB and the extracytoplasmic stress response in V. vulnificus, mutants with defined mutations in rseB and two important members of the extracytoplasmic stress regulon, rpoE and degP, were constructed for analysis of virulence, colony morphology, and stress-associated phenotypes. Deletion of rseB caused reversible phase variation in the colony morphotype that was associated with extracellular polysaccharides. Translucent and transparent morphotype strains were attenuated for virulence. rpoE and degP deletion mutants were sensitive to membrane-perturbing agents and heat but were not significantly attenuated for V. vulnificus virulence in mice. These results reveal complex relationships between regulation of the extracytoplasmic stress response, exopolysaccharides, and the virulence of V. vulnificus.Vibrio vulnificus is a gram-negative estuarine bacterium responsible for severe opportunistic infections (for a review, see reference 17). Ingestion of raw contaminated seafood can lead to septicemia in susceptible patients, while contact with contaminated seawater or seafood can cause wound infection, which may progress to necrotizing fasciitis and sepsis. Mortality rates for sepsis and wound infection can be as high as 75% and 50%, respectively. Predisposing conditions for septicemia include liver disease, cirrhosis, hemochromatosis, diabetes, and immune compromise, while wound infection can occur in otherwise healthy persons.Several virulence factors have been identified for V. vulnificus, most notably the antiphagocytic capsule (55, 65), RtxA toxin (26, 28, 32), and iron acquisition systems (31, 64). For a review, see reference 17. However, much is yet to be discovered, particularly the mechanisms of extreme tissue damage and rapid growth in host tissues (17). To examine these traits, we focused on the factors that are localized to the bacterial cell surface or are secreted into the extracellular space, considering that most virulence factors are exported to interact with the host. Alkaline phosphatase (phoA) mutagenesis is a useful tool for identifying genes encoding exported products (33), based on the principle that alkaline phosphatase is active only when it is exported beyond the bacterial cytoplasm. Randomly generated phoA gene fusions, most often generated via TnphoA (33), must be in genes encoding exported proteins to have enzyme activity detected by plating on the chromogenic substrate 5-bromo-4-chloro-3-indolylphosphate (BCIP). In our studies, TnphoA did not work effectively in V. vulnificus for unknown reasons. We therefore created a mini-Tn5 transposon-based ′phoA delivery system, miniTn5phoA (8), that works well in V. vulnificus.Using this method, we identified a phoA mutant that had an in-frame fusion of ′phoA to the gene encoding RseB, a periplasmic negative regulator of sigma E (σE) activity. The rseB mutant exhibited several interesting phenotypes, including phase variation between translucent and opaque colony morphologies and attenuated virulence. σE is an alternative RNA polymerase sigma factor that controls an extensive regulon involved in responding to cell envelope stresses (48). This response, termed the extracytoplasmic stress response (ESR), is essential for maintaining the envelope integrity of gram-negative bacteria under certain stress conditions (for a review, see reference 48). Because rseB is involved in the ESR, we determined the role of the σE-mediated ESR in V. vulnificus. We also investigated the possible reasons for the translucent morphology of RseB variants by comparing these variants with an acapsular translucent mutant of V. vulnificus. This study uncovered a possible role for RseB in phase variation of extracellular polysaccharide (EPS) expression and is the first study to investigate the role of the ESR in the virulence of V. vulnificus.  相似文献   

3.
Roh et al. report a positive feedback loop between sleep-wake irregularities and aggregation of β-amyloid peptide, suggesting that sleep alterations could be an early event in Alzheimer's disease.  相似文献   

4.
A long-standing question in infectious disease dynamics concerns the role of transmission heterogeneities,which are driven by demography,behavior,and interventions.On the basis of detailed patient and contact-tracing data in Hunan,China,we find that 80% of secondary infections traced back to 15% of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)primary infections,which indicates substantial transmission heterogeneities.Transmission risk scales positively with the duration of exposure and the closeness of social interactions and is modulated by demographic and clinical factors.  相似文献   

5.
Candida glabrata has emerged as a major pathogen in invasive candidiasis in recent years. Currently, guidelines for invasive candidiasis treatment recommend fluconazole or an echinocandin as the first-line therapy. Nevertheless, the resistance of Candida glabrata to echinocandin is an emerging problem and has been partly associated with mutations in the FKS1 and FKS2 genes. The Etest® is an appropriate method for determining antifungal susceptibility in emergency routine diagnosis. In this work, we evaluated the reliability of the Etest® in comparison with the two reference broth microdilution methods, Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST), to assess the caspofungin resistance of 193 isolates of Candida glabrata. The interpretation of minimum inhibitory concentration (MIC) values was also discussed according to different breakpoints. Moreover, FKS1 and FKS2 mutations were investigated for isolates with high MICs. Our results showed that the MIC50 value was similar to the MIC90 value for each method. The Etest® method showed the lowest MIC values, whereas EUCAST presented the highest. Categorical agreement between the Etest® and CLSI methods was 100 % and 36 % using the breakpoints proposed by Arendrup et al. (Antimicrob Agents Chemother 56(7):3965–3968, 2012) and Pfaller et al. (Int J Antimicrob Agents 38(1):65–69, 2011), respectively. Two isolates showed high MIC values with the three methods and both presented FKS2 mutations. A novel FKS2 mutation was also reported for one isolate. Future epidemiological studies should also evaluate the reliability of the Etest® to detect echinocandin resistance, as it remains a routine method.  相似文献   

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The Check-MDR CT102 microarray, aimed at identifying bacteria producing extended-spectrum β-lactamase (ESBL) (SHV, TEM, and CTX-M) and carbapenemase (KPC, OXA-48, VIM, IMP, and NDM-1), was evaluated on a total of 144 Gram-negative strains expressing various β-lactamases. The sensitivity and specificity were 100% for most tested genes, suggesting that this assay allows accurate identification of common ESBL and carbapenemase producers from bacterial cultures.  相似文献   

9.
Glycinin and β-conglycinin have been identified as major food/feed allergens. But effects of glycinin and β-conglycinin on enterocyte migration in piglets are scare. Fifteen weanling (7.06±0.18 kg) General No. 1 barrows, weaned at 28 days, were used. The piglets were randomly allotted to three (A, B and C) treatments with five replicates. The piglets in the A group (control group) were fed diets without ingredients originating from leguminous products, while the piglets in the B or C groups were fed the diets containing purified glycinin or β-conglycinin, which replaced protein in Group A by 4%. All the experimental periods were followed for 7 days. Five-micrometre thick sections of small intestinal tissue were stained with the TUNEL method to assess apoptotic activity, and with Ki-67 immunohistochemistry to assess cellular proliferation. The results indicated that glycinin or β-conglycinin increased proliferative index and apoptotic index in duodenum for piglets (P<0.05).  相似文献   

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Objective: The aims of this study were to evaluate serum levels of acute phase reactants, such as CRP and cytokines (TNF-α and IL-6) in patients who have undergone thoracotomy and to investigate the effects of flurbiprofen on postoperative inflammatory response.Methods: Forty patients undergoing posterolateral thoracotomy were randomly divided into 2 groups of 20 each. Control group received tramadol (4 x 100 mg) intravenously for four days, and flurbiprofen group received both tramadol (4 x 100 mg) and flurbiprofen (2 x 100 mg). Blood samples were collected before surgery and at the 3th and 168th hours after surgical procedure to measure serum CRP, IL-6, and TNF-α. Pain visual analog scales were recorded daily during the first four postoperative days. Spirometric measurement of forced expiratory volume in the first second (FEV 1) was done before and four days after the operation.Results: The serum CRP, IL-6, and TNF-α levels in both groups increased significantly at 3th hour after thoracotomy. Serum TNF-α levels did not differ significantly between the groups at postoperative 4th day. However, IL-6 and CRP were significantly lower in flurbiprofen group than in control group at the same day (p<0.05). Visual analog scale was significantly lower in flurbiprofen group at 6th, 12th, 48th, 72th, and 96th hours postoperatively (p<0.05). The patients receiving flurbiprofen had higher FEV 1 values when compared with control group at postoperative 4th day.Conclusions: Patients undergoing thoracotomy showed reduced postoperative pain, mean additional analgesic consumption, and serum IL-6 and CRP levels, when flurbiprofen was added to systemic analgesic therapy. Analgesia with anti-inflammatory drug may contribute to the attenuation of the postoperative inflammatory response and prevent postoperative pain in patients undergoing thoracotomy.  相似文献   

13.
Gout tophi are characterised by foreign body granulomas consisting of mono- and multinucleated macrophages surrounding deposits of monosodium urate microcrystals. After primary formation, granulomas grow associated with degradation of the extracellular matrix. Based on this background, we have sought (1) to investigate whether during granuloma's growth new macrophages are recruited into the tophi, (2) to find in situ evidence for macrophages' active role in matrix degradation and (3) to examine whether shrunk cells seen within gout tophi are apoptotic. Immunohistochemistry showed that perivascular localised mononuclear cells are CD68+, S100A8+, S100A9+, 25F9-, representing freshly migrated monocytes/macrophages. In contrast, almost all CD68+ mono- and multinucleated cells arranged within granulomas were S100A8-, S100A9-, 25F9+, representing mature (non-migrating) macrophages. Serial sections revealed that macrophages co-express tumour necrosis factor (TNF)-alpha and matrix metalloproteinases (MMPs) 2 and 9. In situ end-labelling of fragmented DNA demonstrated that CD68+ macrophages undergo apoptosis within gout tophi. Our data show that macrophages are continuously recruited into the gout tophi. These macrophages co-produce the proinflammatory cytokine TNF-alpha and two TNF-alpha inducible lytic enzymes, MMP-2 and MMP-9, suggesting that TNF-alpha may induce MMP production followed by matrix degradation within foreign body granulomas. In parallel, macrophages undergo apoptosis, a phenomenon that may restrict the destructive potential of inflammatory macrophages.  相似文献   

14.
HrpA was found as a ribosome-associated protein which appeared in heat-stressed Mycobacterium bovis Bacillus Calmette-Guérin. Here, we have studied the function of HrpA in vitro. HrpA is a heat shock protein belonging to a small heat shock protein family. The putative molecular mass was 17784.86 kDa. Recombinant HrpA formed large complexes of nonamer or dodecamer. HrpA prevented the aggregation of enzymes under heat shock conditions, and it formed stable complexes with partially denatured enzymes. HrpA was induced temporarily by oxygen repletion after anaerobic condition.  相似文献   

15.
We have developed poly(L: -lactide-co-glycolide) (PLGA) based composites using sol-gel derived bioactive glasses (S-BG), previously described by our group, as composite components. Two different composite types were manufactured that contained either S2-high content silica S-BG, or A2-high content lime S-BG. The composites were evaluated in the form of sheets and 3D scaffolds. Sheets containing 12, 21, and 33?vol.% of each bioactive glass were characterized for mechanical properties, wettability, hydrolytic degradation, and surface bioactivity. Sheets containing A2 S-BG rapidly formed a hydroxyapatite surface layer after incubation in simulated body fluid. The incorporation of either S-BG increased the tensile strength and Young's modulus of the composites and tailored their degradation rates compared to starting compounds. Sheets and 3D scaffolds were evaluated for their ability to support growth of human bone marrow cells (BMC) and MG-63 cells, respectively. Cells were grown in non-differentiating, osteogenic or osteoclast-inducing conditions. Osteogenesis was induced with either recombinant human BMP-2 or dexamethasone, and osteoclast formation with M-CSF. BMC viability was lower at higher S-BG content, though specific ALP/cell was significantly higher on PLGA/A2-33 composites. Composites containing S2 S-BG enhanced calcification of extracellular matrix by BMC, whereas incorporation of A2 S-BG in the composites promoted osteoclast formation from BMC. MG-63 osteoblast-like cells seeded in porous scaffolds containing S2 maintained viability and secreted collagen and calcium throughout the scaffolds. Overall, the presented data show functional versatility of the composites studied and indicate their potential to design a wide variety of implant materials differing in physico-chemical properties and biological applications. We propose these sol-gel derived bioactive glass-PLGA composites may prove excellent potential orthopedic and dental biomaterials supporting bone formation and remodeling.  相似文献   

16.
《Genetics in medicine》2019,21(6):1355-1362
PurposeRacial minority populations are underrepresented in genomics research. This study enrolled African-descended individuals in a sequencing study and reported their characteristics.MethodsWe purposively recruited 467 individuals self-identified as African, African American, or Afro-Caribbean to the ClinSeq® study and surveyed them about knowledge, motivations, expectations, and traits. Summary statistics were calculated and compared with data from the study’s original cohort, which was primarily White and self-referred.ResultsRecruitment took five years and 83% of enrollees completed the survey. Participants had modest knowledge about benefits and limitations of sequencing (s = 5.1, ranges: 0–10), and less than the original cohort (= 7.5 and 7.7, respectively). Common motivations to enroll were learning information relevant to personal health (49%) or family members’ health (33%), and most had realistic expectations of sequencing. Like the original cohort, they had high levels of optimism, openness, and resilience.ConclusionEarly adopters may have relatively consistent personality traits irrespective of majority/minority status and recruitment methods, but high levels of genomics knowledge are not universal. Research should determine whether recruitment and consent procedures provide adequate education to promote informed choices and realistic expectations, which are vital to ethical research and increasing genomics research participation in underrepresented communities.  相似文献   

17.

Background

One of the biggest challenges in the spirituality, religiosity, and health field is to understand how patients and physicians from different cultures deal with spiritual and religious issues in clinical practice.

Purpose

The present study aims to compare physicians’ perspectives on the influence of spirituality and religion (S/R) on health between Brazil, India, and Indonesia.

Method

This is a cross-sectional, cross-cultural, multi-center study carried out from 2010 to 2012, examining physicians’ attitudes from two continents. Participants completed a self-rated questionnaire that collected information on sociodemographic characteristics, S/R involvement, and perspectives concerning religion, spirituality, and health. Differences between physicians’ responses in each country were examined using chi-squared, ANOVA, and MANCOVA.

Results

A total of 611 physicians (194 from Brazil, 295 from India, and 122 from Indonesia) completed the survey. Indonesian physicians were more religious and more likely to address S/R when caring for patients. Brazilian physicians were more likely to believe that S/R influenced patients’ health. Brazilian and Indonesians were as likely as to believe that it is appropriate to talk and discuss S/R with patients, and more likely than Indians. No differences were found concerning attitudes toward spiritual issues.

Conclusion

Physicians from these different three countries had very different attitudes on spirituality, religiosity, and health. Ethnicity and culture can have an important influence on how spirituality is approached in medical practice. S/R curricula that train physicians how to address spirituality in clinical practice must take these differences into account.
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18.
Human blood serum exhibiting β-adrenoceptor-sensitizing activity does not prevent manifestation of similar activity of histidine, tryptophan, tyrosine, mildronat, and preductal. This opens prospects for the use of analogues of endogenous β-adrenoceptor-sensitizing agent in clinical practice.  相似文献   

19.
A series of tri-component copolymers was synthesized by ring opening copolymerization of cyclic lactones, i.e. glycolide, L-lactide, and caprolactone, using stannous octoate as a catalyst. Various techniques, including FT-IR, 1H NMR, DSC, X-ray diffraction, tensile strength, and contact angle measurements, were used to elucidate structural characteristics, thermal behavior, mechanical properties, and hydrophilicity of the resulting copolymers. Data showed that the properties of these copolymers could be modulated by adjusting the composition of the copolymers. The DSC and X-ray analysis demonstrated amorphous structures for most of the PGLC copolyesters. The degradation behavior of these PGLC copolymers had been studied in vitro, i.e. in 0.10 M pH 7.4 phosphate buffer solution (PBS). The degradation was monitored by intrinsic viscosity and weight loss measurements. SEM and GPC were also used to monitor the morphology and molecular weight change during degradation. The PGLC copolymers were shown to have variable degradation rates, and most of them could disappear within a few months due to their amorphous structure and low glass transition temperature.  相似文献   

20.
Due to their minority among the non-Hodgkin lymphomas, classification of extranodal T-cell lymphomas, including those of the natural killer (NK) cell type, has long been controversial and unclear, and the clinical outcome is not well clarified. Recently, new well-defined disease entities have been described based on tumor cell biology combined with anatomical site, clinical features, Epstein-Barr virus (EBV) status, and cell lineage as determined by immunophenotype and genotype. Cytological features are usually not specific, and there are no morphologic correlates with the classification of extranodal T/NK-cell lymphomas. From a human T-cell lymphotropic virus type 1 (HTLV-1) endemic area in Japan, we report here the analysis of 144 cases of extranodal T-cell lymphoma, from which fresh tissues were available. As the clinicopathological features were known, we simply reclassified the cases according to cell lineage and anatomical site. The extranodal T-cell lymphomas were classified into three types on the basis of cell lineage: (1) natural killer cell (NK) type [sCD3-, CD56+, T-cell receptor gene (TCR) germline], (2) cytotoxic T lymphocyte (CTL) type [sCD3+, TIA-1+, TCR rearranged, CD8+/-, CD4-/+], and (3) non-NK/CTL type [sCD3+, TIA-1-, TCR rearranged, CD4+/-, CD8-/+]. In addition to cell lineage, the anatomical site and clinical features were added for subclassification. NK type tumors (35 cases) included the lymphoblastic type, nasal/nasal-type NK lymphoma, and NK leukemia. The CTL type (46 cases) included anaplastic large cell lymphoma (ALCL), cutaneous type, intestinal, gamma delta T-cell type, and an unspecified type. The non-NK/CTL type (63 cases) included adult T-cell leukemia/lymphoma (ATLL), mycosis fungoides (MF), and an unspecified type. With the exception of ATLL and MF, most extranodal T-cell lymphomas had a cytotoxic phenotype of NK type or CTL type and were often associated with EBV infection. MF and the unspecified type within the non-NK/CTL tumors, with the exception of ATLL, had a favorable prognosis. However, NK and CTL types, with the exception of ALCL, were associated with a poor prognosis. Our results indicate that anatomical site and cell lineage are useful predictors of clinical outcomes of extranodal T-cell lymphomas.  相似文献   

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