Unbalanced and degraded mixtures (UDM) are very common in forensic DNA analysis. For example, DNA signals from criminal suspects are masked by a large amount of DNA from victims, or cell-free fetal DNA (cffDNA) in maternal plasma is masked by a high background of maternal DNA. Currently, detecting minor DNA in these mixtures is complex and challenging. We developed a new set of SNP-SNP microhaplotypes with short amplicons, and we successfully genotyped them using the new method of amplification-refractory mutation system PCR (ARMS-PCR) combined with SNaPshot technology based on a capillary electrophoresis (CE) platform. This panel reflects a high polymorphism in the Southwest Chinese Han population and thus has excellent potential for mixture studies. We evaluated the feasibility of this panel for UDM detection and noninvasive prenatal paternity testing (NIPPT). Fifteen SNP-SNPs detected minor DNA of homemade DNA mixtures, with a sensitivity of 0.025-0.05 ng and a specificity of 1:1,000. In addition, the panel successfully genotyped degraded DNA from single and mixed samples. Finally, 15 SNP-SNPs were applied to 26 trios. All samples displayed positive results with at least one marker to detect cffDNA. Besides, all fetal alleles in maternal plasma were confirmed by genotyping fetal genomic DNA from amniocentesis and paternal genomic DNA from peripheral blood. The results indicated that the SNP-SNP strategy based on the CE platform was useful for UDM detection and NIPPT.
Abstract Background: Nocardiosis is a rare suppurative infectious disease caused by Nocardia, a gram-positive filamentous bacterium that is widely distributed in air, water, soil and other media. It usually occurs in patients treated with immunosuppressants but can also occur in healthy people. The aim of this study was to describe the course of two patients with rheumatic immune diseases who died of pneumonia and brain, renal, liver abscesses and sepsis caused by Nocardia farcinica infection. Case presentation: A 74-year-old retired male, diagnosed with dermatomyositis (DM), and a 54-year-old female farmer, diagnosed with systemic lupus erythematosus (SLE), both taking glucocorticoids and immunosuppressants, suffered from pneumonia and brain, renal, and liver abscesses and sepsis caused by Nocardia farcinica. Their medical treatment processes were very complicated, and they underwent multiple examinations and multidisciplinary consultations. They were finally diagnosed with pneumonia, brain, renal, and liver abscesses and sepsis caused by Nocardia farcinica infection through blood, sputum and bronchoalveolar lavage fluid culture. They were treated with antibacterial drugs, but the course was insufficient because of economic reasons, and eventually, they died. Conclusions: Nocardia farcinica is a rare but possible cause of pneumonia or brain, renal, liver abscesses or sepsis inpatients with rheumatic immune diseases. If infection is not ruled out in the lungs or other organs, it is necessary to actively utilise a variety of pathogenic tests, including blood culture. Once patients with immunosuppressive agents get pneumonia, brain abscesses, renal abscesses, liver abscesses or sepsis caused by Nocardia farcinica, they are in a critical condition and easily die.
ABSTRACT We report a small case series of childhood‐onset Takayasu arteritis (c‐TA) presenting as pyoderma gangrenosum (PG)‐like vasculitic ulceration. The cutaneous vasculitic ulcers in systemic vasculitis are rare and severe, sometimes leading to delayed diagnosis and treatment. We summarised the clinical features and highlighted the warning signs of c‐TA associated with PG‐like vasculitic ulceration.
Alzheimer's disease (AD) is a serious public health crisis with only one current modifying treatment. The reduction of amyloid load by targeting γ-secretase (GS) has been a leading approach in AD drug discovery and development. Despite the focus on GS inhibition, multiple GS inhibitors (GSIs) have failed in clinical trials as a result of side effects including exacerbated cognitive decline. These side effects are largely attributable to inhibition of normal GS function. Standard enzyme inhibitors target catalytic or allosteric sites of the enzyme, including the active site presenilin, as previous GSIs did. To avoid issues observed from broad-spectrum GSIs we discovered that fragment 6H8 that covalently binds to the substrate of GS, the transmembrane domain of amyloid precursor protein (APPTM). Nuclear Magnetic Resonance (NMR) Spectroscopy combined with MALDI-TOF-MS established 6H8 covalently binds to APPTM. 6H8 acts as a Michael acceptor and covalently links to the side chain amines of lysine residues, specifically targeting a cluster of C-terminal lysines K53-K55. Through this modification, 6H8 can inhibit intramembrane proteolysis of an archaeal homolog of presenilin (the active subunit of GS)
Protein post‐translational modifications (PTMs) play crucial roles in various cellular processes. Despite their significance, only a few PTMs have been extensively studied at the proteome level, primarily due to the scarcity of reliable, convenient, and low‐cost sensing methods. Here, we present a straightforward and effective strategy for detecting PTMs on short peptides through host‐guest interaction‐assisted nanopore sensing. Our results demonstrate that the identity of 13 types of PTMs in a specific position of a phenylalanine‐containing peptide could be determined via current blockage during translocation of the peptide through α‐hemolysin nanopores in the presence of cucurbit[7]uril. Furthermore, we extend this strategy by incorporating a short peptide into the probe, enabling the discrimination of various PTMs, positional isomers, and even multiple PTMs on the target peptide. With ongoing improvements, our method holds promise for practical applications in sensing PTMs in biologically relevant samples, offering an efficient alternative to traditional mass spectrometry approaches.
While the cytogenetic and genetic characteristics of childhood acute lymphoblastic leukemias (ALL) are well studied, less clearly understood are the contributing epigenetic mechanisms that influence the leukemia phenotype. Our previous studies and others identified gene mutation (RAS) and DNA methylation (FHIT) to be associated with the most common cytogenetic subgroup of childhood ALL, high hyperdiploidy (having five more chromosomes). We screened DNA methylation profiles, using a genome-wide high-dimension platform of 166 childhood ALLs and 6 normal pre-B cell samples and observed a strong association of DNA methylation status at the PTPRG locus in human samples with levels of PTPRG gene expression as well as with RAS gene mutation status. In the 293 cell line, we found that PTPRG expression induces dephosphorylation of ERK, a downstream RAS target that may be critical for mutant RAS-induced cell growth. In addition, PTPRG expression is upregulated by RAS activation under DNA hypomethylating conditions. An element within the PTPRG promoter is bound by the RAS-responsive transcription factor RREB1, also under hypomethylating conditions. In conclusion, we provide evidence that DNA methylation of the PTPRG gene is a complementary event in oncogenesis induced by RAS mutations. Evidence for additional roles for PTPR family member genes is also suggested. This provides a potential therapeutic target for RAS-related leukemias as well as insight into childhood ALL etiology and pathophysiology.
The global outbreak of Coronavirus disease 2019 (COVID-19) was characterized as a pandemic by World Health Organization on March 11, 2020,1"WHO characterizes COVID-19 as a pandemic". World Health Organization. Available at:https://www.who.int/emergencies/diseases/novel-coronavirus-2019/events-as-they-happen. Accessed May 7, 2020.Google Scholar and this pandemic has posed a great impact on the public health and socioeconomic around the world, especially on developing countries. As of May 6, 2020, almost 3.6 million confirmed cases of COVID-19 have been reported to World Health Organization, and nearly 250,000 have lost their lives.2"Coronavirus disease 2019 (COVID-19) Situation Report – 107". World Health Organization. Available at:https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200506covid-19-sitrep-107.pdf?sfvrsn=159c3dc_2. Accessed May 7, 2020.Google Scholar Health care workers (HCWs) are at high risk for acquiring infection while fighting the pandemic at the frontline, and several studies report that incidents of nosocomial infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among HCWs are common.3Zhan M Qin Y Xue X Zhu S Death from Covid-19 of 23 health care workers in China.N Engl J Med. 2020; 382: 2267-2268Crossref PubMed Scopus (217) Google Scholar,4Characteristics of health care personnel with COVID-19 – United States, February 12-April 9, 2020. MMWR Morb Mortal Wkly Rep. 2020;69:477-481.Google Scholar And the infection of HCWs appears not only in infectious disease and respiratory departments, but also in other departments that may be easily overlooked, such as gastroenterology departments.3Zhan M Qin Y Xue X Zhu S Death from Covid-19 of 23 health care workers in China.N Engl J Med. 2020; 382: 2267-2268Crossref PubMed Scopus (217) Google Scholar Because HCWs involved in gastrointestinal (GI) endoscopy operations have close contact with patients, both occupational exposure and cross-infection occur easily. Accordingly, GI endoscopy operations may increase the risk of transmission of SARS-CoV-2. A few reasons are as follows. To start with, during the pandemic, the use of respiratory fiberoptic bronchoscopes in the general ward was stopped in most hospitals in many countries. Even if it was not stopped, the risk of infection was low due to rigorous personal protections among HCWs in respiratory departments, such as the use of N95 masks, protective suits, and other personal protective equipment (PPE). However, HCWs performing GI endoscopy operations in general outpatient clinics are vulnerable to the SARS-CoV-2 because of the lack of awareness of the risk of infection, inadequate protective measures, and nonstandard protective procedures (eg, masks may not be worn properly).5Perisetti A Garg S Inamdar S Tharian B Role of face mask in preventing bacterial exposure to the endoscopist's face.Gastrointest Endosc. 2019; 90: 859Abstract Full Text Full Text PDF PubMed Scopus (13) Google Scholar Second, health systems in many countries were not well-prepared for this sudden, fast-spreading, and widespread pandemic, which has led to a shortage of medical supplies, such as face shields, masks, gloves, goggles and gowns, and so on, in more and more countries, thus increasing the risk of infection among HCWs. Besides, some people do not correctly understand the seriousness of the pandemic, leading to incomprehension of citizens for some of prevention and control measures issued, or even overlook, which will accelerate the spread of the pandemic. Third, several studies indicated that a significant portion of infected patients never developed any symptoms (asymptomatic) or even those who eventually developed symptoms ("presymptomatic") could transmit SARS-CoV-2 to others before showing symptoms,6Kimball A Hatfield KM Arons M et al.Asymptomatic and presymptomatic SARS-CoV-2 infections in residents of a long-term care skilled nursing facility – King County, Washington, March 2020.MMWR Morb Mortal Wkly Rep. 2020; 69: 377-381Crossref PubMed Google Scholar, 7Bai Y Yao L Wei T et al.Presumed asymptomatic carrier transmission of COVID-19.JAMA. 2020; 323: 1406-1407Crossref PubMed Scopus (3067) Google Scholar, 8Li R Pei S Chen B et al.Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (SARS-CoV2).Science. 2020; 368: 489-493Crossref PubMed Scopus (2263) Google Scholar which would increase the occupational exposure risk and the possibility of cross-infection of HCWs in the GI endoscopy room, thereby possibly causing "Butterfly Effect." Fourth, viral host receptor angiotensin-converting enzyme 29Zhou P Yang XL Wang XG et al.A pneumonia outbreak associated with a new coronavirus of probable bat origin.Nature. 2020; 579: 270-273Crossref PubMed Scopus (14396) Google Scholar was found in both the upper and lower GI tract where it was expressed at nearly 100-fold higher levels than in respiratory organs10ACE2 angiotensin I converting enzyme 2 [Homo sapiens (human)]. Gene ID: 59272. Available at:https://www.ncbi.nlm.nih.gov/gene/59272. Accessed May 7, 2020.Google Scholar and Xiao et al demonstrated both viral RNA and viral nucleocapsid protein staining were detected in esophageal mucous tissue.11Xiao F Tang M Zheng X Liu Y Li X Shan H Evidence for gastrointestinal infection of SARS-CoV-2.Gastroenterology. 2020; 158: 1831-1833Abstract Full Text Full Text PDF PubMed Scopus (2003) Google Scholar We now know from several recent studies digestive symptoms are common in patients with COVID-19 and part of patients experience diarrhea as the first symptom in their disease course or present digestive symptoms alone.12Jin X Lian JS Hu JH et al.Epidemiological, clinical and virological characteristics of 74 cases of coronavirus-infected disease 2019 (COVID-19) with gastrointestinal symptoms.Gut. 2020; 69: 1002-1009Crossref PubMed Scopus (929) Google Scholar, 13Redd WD, Zhou JC, Hathorn KE, et al. Prevalence and characteristics of gastrointestinal symptoms in patients with SARS-CoV-2 infection in the United States: a multicenter cohort study [e-pub ahead of print]. Gastroenterology. https://doi.org/10.1053/j.gastro.2020.04.045. Accessed June 16, 2020.Google Scholar, 14Han C Duan C Zhang S et al.Digestive symptoms in COVID-19 patients with mild disease severity: clinical presentation, stool viral RNA testing, and outcomes.Am J Gastroenterol. 2020; 115: 916-923Crossref PubMed Scopus (401) Google Scholar Of note, a recent study reported that viral RNA has been detected in as many as 53% of sampled patients' stool samples and nearly 23.3% of the stools were still positive after the respiratory viral nucleic acid converted to negative.11Xiao F Tang M Zheng X Liu Y Li X Shan H Evidence for gastrointestinal infection of SARS-CoV-2.Gastroenterology. 2020; 158: 1831-1833Abstract Full Text Full Text PDF PubMed Scopus (2003) Google Scholar All of the above supported that oral-fecal transmission might be a potential transmission route for COVID-19. Finally, the process of GI endoscopy diagnosis and treatment requires the use of water and CO2 insufflation for luminal examination of the GI tract. Use of multiple interventions during the multiple endoscopic procedures such biopsy forceps especially during colonoscopy can carry a risk of recognized and unrecognized spill to the endoscopist face.5Perisetti A Garg S Inamdar S Tharian B Role of face mask in preventing bacterial exposure to the endoscopist's face.Gastrointest Endosc. 2019; 90: 859Abstract Full Text Full Text PDF PubMed Scopus (13) Google Scholar,15Perisetti A, Gajendran M, Boregowda U, Bansal P, Goyal H. COVID-19 and gastrointestinal endoscopies: current insights and emergent strategies [e-pub ahead of print]. Digest Endosc. https://doi.org/10.1111/den.13693. Accessed June 14, 2020.Google Scholar,16Johnston ER Habib-Bein N Dueker JM et al.Risk of bacterial exposure to the endoscopist's face during endoscopy.Gastrointest Endosc. 2019; 89: 818-824Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar Furthermore, the risk of bioaerosolization of GI secretions is a real risk.17van Doremalen N Bushmaker T Morris DH et al.Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1.N Engl J Med. 2020; 382: 1564-1567Crossref PubMed Scopus (6689) Google Scholar,18Jiang Y, Wang H, Chen Y, et al. Clinical data on hospital environmental hygiene monitoring and medical staff protection during the coronavirus disease 2019 outbreak [e-pub ahead of print]. medRxiv. https://doi.org/10.1101/2020.02.25.20028043. Accessed April 16, 2020Google Scholar Much can be done to reduce the risk of SARS-CoV-2 transmission caused by GI endoscopy operations. Due to HCWs in endoscopy units are at high risk for acquiring COVID-19, many international/national societies, such as the Joint GI Society (ie, American Society of Gastrointestinal Endoscopy, American Association for the Study of Liver Diseases, American College of Gastroenterology, and American Gastroenterology Association), European Society of GI Endoscopy (ESGE), Board of the Chapter of Gastroenterologists of Singapore Academy of Medicine, have changed or updated their recommendations for GI endoscopic examinations.19Bezzara J, Pochapin M, El-Serag H, Vargo J. Joint GI society message on COVID-19 – American College of Gastroenterology [updated 2020-03-15]. Available at:https://gi.org/2020/03/15/joint-gi-society-message-on-covid-19/. Accessed May 7, 2020.Google Scholar, 20Gralnek IM Hassan C Beilenhoff U et al.ESGE and ESGENA position statement on gastrointestinal endoscopy and the COVID-19 pandemic.Endoscopy. 2020; 52: 483-490Crossref PubMed Scopus (256) Google Scholar, 21Ang TL Li JW Vu CK et al.Chapter of gastroenterologists professional guidance on risk mitigation for gastrointestinal endoscopy during COVID-19 pandemic in Singapore.Singapore Med J. 2020; 61: 345-349Crossref PubMed Scopus (7) Google Scholar According to their recommendations, first, prescreening should be carried out before arranging endoscopy for patients and the nonurgent/elective procedures not only should be temporarily postponing but also should be further classified into nonurgent/postpone and nonurgent/perform depending on the clinical need of the endoscopy. Second, once a patient was scheduled for an endoscopic procedure, stratifying patients for risk of COVID-19 should be carried out before the examination and the use of PPE during the examination was also required. Basic PPE included gloves, mask, eye shield/goggle, or face shield, and gown, and ESGE recommended that 2 pairs of gloves, respiratory mask, and related equipment were required for high-risk individuals.20Gralnek IM Hassan C Beilenhoff U et al.ESGE and ESGENA position statement on gastrointestinal endoscopy and the COVID-19 pandemic.Endoscopy. 2020; 52: 483-490Crossref PubMed Scopus (256) Google Scholar Finally, Joint GI society and ESGE recommended that all patients should be followed up by telephone 7-14 days after the procedure during the pandemic.19Bezzara J, Pochapin M, El-Serag H, Vargo J. Joint GI society message on COVID-19 – American College of Gastroenterology [updated 2020-03-15]. Available at:https://gi.org/2020/03/15/joint-gi-society-message-on-covid-19/. Accessed May 7, 2020.Google Scholar,20Gralnek IM Hassan C Beilenhoff U et al.ESGE and ESGENA position statement on gastrointestinal endoscopy and the COVID-19 pandemic.Endoscopy. 2020; 52: 483-490Crossref PubMed Scopus (256) Google Scholar At this critical time, our hospital also has implemented a series of measures to reduce transmission risk in the GI Endoscopy unit. First of all, patients, who seek GI endoscopy examination or treatment, were required to fill Health QR code beforehand and only those who had no symptoms of COVID-19 and no history of contact of confirmed or suspected cases, could enter outpatient. The Health QR code is a digital health assessment certificate that presents different colors depending on the health information and epidemiological history reported online by residents. Residents with a green code indicated they had a low current risk of being infected, while residents with yellow or red codes were required to self-quarantine for 7 or 14 days as well as to report their daily health status to exclude infection before the codes turned green. Secondly, once a patient was admitted to the outpatient hall, inquiring epidemiological history again and taking temperature for patients were required, followed by chest CT scans and nucleic acid PCR or serological test. Only those, who possessed green Health QR code, did not have any symptoms of COVID-19 and had a negative result for SARS-CoV-2 detection, were admitted to the GI Endoscopy unit for examination or treatment. The use of PPE during the examination was also required in our hospital. Especially of note, up to now, no GI operation-related COVID-19 nosocomial infections have been reported in our hospital. Form the above, we can know that strict preinspection and screening procedures, and comprehensive protective measures are needed to curb the spread of COVID-19 in digestive endoscopy. So, at this critical time all hospitals should take the best protective measures according to their own conditions to minimize the risk of transmission caused by GI endoscopy. Hopefully, all suggestions mentioned above could benefit to worldwide HCWs during the COVID-19 pandemic.
Squamous metaplasia (SM) is common in smokers and is associated with airway obstruction in chronic obstructive pulmonary disease (COPD). A major mechanism of airway obstruction in COPD is thickening of the small airway walls. We asked whether SM actively contributes to airway wall thickening through alteration of epithelial-mesenchymal interactions in COPD. Using immunohistochemical staining, airway morphometry, and fibroblast culture of lung samples from COPD patients; genome-wide analysis of an in vitro model of SM; and in vitro modeling of human airway epithelial-mesenchymal interactions, we provide evidence that SM, through the increased secretion of IL-1beta, induces a fibrotic response in adjacent airway fibroblasts. We identify a pivotal role for integrin-mediated TGF-beta activation in amplifying SM and driving IL-1beta-dependent profibrotic mesenchymal responses. Finally, we show that SM correlates with increased severity of COPD and that fibroblast expression of the integrin alpha(v)beta(8), which is the major mediator of airway fibroblast TGF-beta activation, correlated with disease severity and small airway wall thickening in COPD. Our findings have identified TGF-beta as a potential therapeutic target for COPD.
We have subcloned and expressed the N-terminal portion of the recently sequenced metabotropic GABA receptor, GABA(B)R1a. This region of the receptor contains a complement protein-like amino acid sequence. The purified 140-residue recombinant protein fragment was soluble and stable. Mass spectrometry indicated formation of four disulfide bonds, as expected if two complement protein modules (CPs, also known as SCRs, Sushi domains) are formed. The circular dichroism spectrum was unusual and characteristic of CPs. Differential scanning calorimetry demonstrated a melting point (64 degrees C), and total enthalpy commensurate with two fully folded domains. We thus conclude that the 1a subtype of the GABA(B) receptor, but not the 1b subtype, contains a pair of CPs and we present a three-dimensional model of this region.
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