15 research outputs found

    Ganglioside composition and histology of a spontaneous metastatic brain tumour in the VM mouse

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    Glycosphingolipid abnormalities have long been implicated in tumour malignancy and metastasis. Gangliosides are a family of sialic acid-containing glycosphingolipids that modulate cell–cell and cell–matrix interactions. Histology and ganglioside composition were examined in a natural brain tumour of the VM mouse strain. The tumour is distinguished from other metastatic tumour models because it arose spontaneously and metastasizes to several organs including brain and spinal cord after subcutaneous inoculation of tumour tissue in the flank. By electron microscopy, the tumour consisted of cells (15 to 20 μm in diameter) that had slightly indented nuclei and scant cytoplasm. The presence of smooth membranes with an absence of junctional complexes was a characteristic ultrastructural feature. No positive immunostaining was found for glial or neuronal markers. The total ganglioside sialic acid content of the subcutaneously grown tumour was low (12.6 ± 0.9 μg per 100 mg dry wt, n= 6 separate tumours) and about 70% of this was in the form of N-glycolylneuraminic acid. In contrast, the ganglioside content of the cultured VM tumour cells was high (248.4 ± 4.4 μg, n= 3) and consisted almost exclusively of N-acetylneuraminic acid. The ganglioside pattern of the tumour grown subcutaneously was complex, while GM3, GM2, GM1, and GD1a were the major gangliosides in the cultured tumour cells. This tumour will be a useful natural model for evaluating the role of gangliosides and other glycolipids in tumour cell invasion and metastasis. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

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    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Molecular identification of mutations associated with anti-tuberculosis drug resistance among strains of Mycobacterium tuberculosis

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    SummaryBackgroundUnderstanding the etiologic organism, antimicrobial resistance mechanisms, and transmission of multidrug-resistant tuberculosis (MDR-TB) can be of great value in optimizing strategies to control and prevent its development and transmission.MethodsOne hundred and fifty-five Mycobacterium tuberculosis complex isolates from patients with pulmonary tuberculosis (TB) in Cairo, Egypt were studied. In vitro drug susceptibility testing against rifampin (RIF), isoniazid (INH), streptomycin (SM), ethambutol (EMB), and pyrazinamide (PZA) was performed. Resistance was studied by the standard agar proportion method. Single strand conformation polymorphism (SSCP) and DNA sequence analysis were used to detect mutations in the genes that encode resistance to rpoB, katG, rpsL, and embB.ResultsAmong 155 consecutive M. tuberculosis isolates, 25 (16.1%) were MDR-TB; 13 of these were from newly diagnosed untreated cases, 12 were from re-treated cases, and none of the MDR-TB isolates had matching IS6110 fingerprints. Among the MDR-TB isolates, rpoB mutations were found in 76% of RIF-resistant isolates, katG mutations were found in 47.1% of INH-resistant isolates, rpsL mutations were found in 55.6% of SM-resistant isolates, and embB mutations were found in 36.4% of EMB-resistant isolates.ConclusionsNo major differences were found in the frequencies of mutations or types of amino acid substitution between newly diagnosed untreated cases and re-treated cases. The high prevalence of MDR-TB at this hospital underscores the need for continuous monitoring of strains and antimicrobial resistance

    Characterization of Mycobacterium tuberculosis Complex Isolates from the Cerebrospinal Fluid of Meningitis Patients at Six Fever Hospitals in Egypt

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    Mycobacterium tuberculosis complex isolates from cerebrospinal fluid of 67 meningitis patients were obtained from six fever hospitals in Egypt. One M. bovis and 66 M. tuberculosis isolates were identified by PCR-restriction fragment length polymorphism (RFLP) analysis of oxyR. Among the M. tuberculosis isolates, 53 unique strain types (with 3 to 16 copies of IS6110) were found by RFLP analyses. Nine clusters (eight with two isolates each and one with six isolates) were also found. Thirty-six spoligotypes, including at least 10 that have been previously reported from other countries, were also observed. Forty-one (62.1%) of the isolates were in spoligotype clusters, and 22 (33%) of the isolates were in RFLP clusters. Fifty-one of the isolates were susceptible in vitro to all of the antituberculosis drugs tested, 11 were monoresistant to capreomycin, rifampin, isoniazid (INH), pyrazinamide, or streptomycin (STR), 4 were resistant to STR and INH, and 1 was resistant to STR, INH, and ethambutol

    Updating the approaches to define susceptibility and resistance to anti-tuberculosis agents: implications for diagnosis and treatment

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    [No Abstract Available]As current or former employees or consultants for FIND, the work of R.B. Baldan, I. Comas, C.M. Denkinger, D.L. Dolinger, S.B. Georghiou, C.U. Koser and T.C. Rodwell on the systematic reviews, including this viewpoint, was supported by Unitaid (grant 2019-32-FIND MDR), BMGF (grant OPP1105925), the German Federal Ministry of Education and Research through KfW, the Dutch Ministry of Foreign Affairs, the Australian Department of Foreign Affairs and Trade, and UK aid from the British people. N. Alvarez and J. Robledo are funded by MinCiencias, Colombia (number 221389622138966621666216 CT-783-2018). A. Aubry and N. Veziris work at the Centre National de Reference des Mycobacteries, which receives an annual grant from Sante Publique France and have received research grants from Janssen for studies on bedaquiline. P. Claxton and I.F. Laurenson are funded through National Services Scotland. I. Comas was supported by PID2019-104477RB-I00 from the Spanish Science Ministry and by ERC (CoG 101001038). M. Egger is supported by the Swiss National Science Foundation (grant number 320030_153442 and 189498) and the US National Institutes of Health, National Institute of Allergy and Infectious Diseases, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Cancer Institute, the National Institute of Mental Health, the National Institute on Drug Abuse, the National Heart, Lung, and Blood Institute, the National Institute on Alcohol Abuse and Alcoholism, the National Institute of Diabetes and Digestive and Kidney Diseases, the Fogarty International Center, and the National Library of Medicine: Asia-Pacific, U01AI069907; CCASAnet, U01AI069923; Central Africa, U01AI096299; East Africa, U01AI069911; NA-ACCORD, U01AI069918; Southern Africa, U01AI069924; West Africa, U01AI069919. M.R. Farhat is supported by NIH NIAID R01AI155765. S.K. Heysell was funded by NIH NIAID grants R01 AI137080 and U01 AI150508. T. Jagielski was supported by a DAINA grant (number 2017/27/L/NZ6/03279) from the National Science Centre, Poland. J.L. Johnson was supported by contracts NO1-AI95383 and NO1-AI-70022 of the US National Institutes of Health. P.M. Keller was supported by Innosuisse 36198.1 IP-LS. C.U. Koser is a research associate at Wolfson College and visiting scientist at the Department of Genetics, University of Cambridge. The Federal Government of Germany supported C.U. Koser as part of his work for the European Laboratory Initiative, WHO Regional Office for Europe. C.U. Koser was further supported by the Royal Society of Tropical Medicine and Hygiene and the National Institute for Health Research Cambridge Biomedical Research Centre and received an observership by the European Society of Clinical Microbiology and Infectious Diseases to the EUCAST Development Laboratory for Bacteria (Vaxjo, Sweden), hosted by Gunnar Kahlmeter and Erika Matuschek. D. Machado and M. Viveiros are funded in part by Fundacao para a Ciencia e a Tecnologia, Portugal (PTDC/BIA-MIC/30692/2017, UID/Multi/04413/2020 and DL57/CEECIND/0256/2017). S. Niemann is supported by the German Center for Infection Research, Excellenz Cluster Precision Medicine in Chronic Inflammation EXC 2167, Leibniz Science Campus Evolutionary Medicine of the LUNG (EvoLUNG). S.V. Omar has received funding to prepare and provide training for Janssen Pharmaceutica activities. L. Rigouts is supported by the Belgian Directorate General for Development. T.C. Rodwell was additionally funded in part by FIND and NIH NIAD, grants: P30 AI036214 and R21 AI135756. T.; Schon is funded by the Swedish Heart and Lung Foundation and the Swedish Research Council. T.R. Sterling has received funding from the US National Institutes of Health and the Centers for Disease Control and Prevention. G. Theron and R. Warren are supported by baseline funding from the South African Medical Research Council. R.J. Wilkinson receives funding from the Wellcome Trust (203135) and from the Francis Crick Institute, which is supported by Cancer Research UK (FC0010218), UKRI (FC0010218) and the Wellcome Trust (FC0010218). The views expressed here are those of the authors and do not necessarily correspond to those of their respective employers.Unitaid [2019-32-FIND MDR]; BMGF [OPP1105925]; German Federal Ministry of Education and Research through KfW; Dutch Ministry of Foreign Affairs; Australian Department of Foreign Affairs and Trade; MinCiencias, Colombia [221389622138966621666216 CT-783-2018]; Sante Publique France; Janssen; National Services Scotland; Spanish Science Ministry [PID2019-104477RB-I00]; ERC [CoG 101001038]; Swiss National Science Foundation [320030_153442, 189498]; US National Institutes of Health; National Institute of Allergy and Infectious Diseases; Eunice Kennedy Shriver National Institute of Child Health and Human Development; National Cancer Institute; National Institute of Mental Health; National Institute on Drug Abuse; National Heart, Lung, and Blood Institute; National Institute on Alcohol Abuse and Alcoholism; National Institute of Diabetes and Digestive and Kidney Diseases; Fogarty International Center; NIH NIAID [R01AI155765, R01 AI137080, U01 AI150508]; DAINA grant from the National Science Centre, Poland [2017/27/L/NZ6/03279]; US National Institutes of Health [NO1-AI95383, NO1-AI-70022]; Innosuisse [36198.1 IP-LS]; Federal Government of Germany; Royal Society of Tropical Medicine and Hygiene; National Institute for Health Research Cambridge Biomedical Research Centre; Fundacao para a Ciencia e a Tecnologia, Portugal [PTDC/BIA-MIC/30692/2017, UID/Multi/04413/2020, DL57/CEECIND/0256/2017]; German Center for Infection Research, Excellenz Cluster Precision Medicine in Chronic Inflammation, Leibniz Science Campus Evolutionary Medicine of the LUNG (EvoLUNG) [EXC 2167]; Belgian Directorate General for Development; FIND; NIH NIAD [P30 AI036214, R21 AI135756]; Swedish Heart and Lung Foundation; Swedish Research Council; Centers for Disease Control and Prevention; South African Medical Research Council; Wellcome Trust [FC0010218, 203135]; Francis Crick Institute - Cancer Research UK [FC0010218]; UKRI [FC0010218]; National Library of Medicine: Asia-Pacific [U01AI069907]; National Library of Medicine: CCASAnet [U01AI069923]; National Library of Medicine: Central Africa [U01AI096299]; National Library of Medicine: East Africa [U01AI069911]; National Library of Medicine: NA-ACCORD [U01AI069918]; National Library of Medicine: Southern Africa [U01AI069924]; National Library of Medicine: West Africa [U01AI069919

    Single-Step PCR Using (GACA)4 Primer: Utility for Rapid Identification of Dermatophyte Species and Strainsâ–¿

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    Dermatophytes are fungi that belong to three genera: Epidermophyton, Microsporum, and Trichophyton. Identification of dermatophyte species is essential for appropriate diagnosis and treatment of dermatophytosis. Routine identification depends on macroscopic and microscopic morphology, which is time-consuming and does not identify dermatophyte strains. In this study, two PCR-based methods were compared for their abilities to identify 21 dermatophyte isolates obtained from Egyptian patients to the species and strain levels. The first method employed a two-step method: PCR amplification, using ITS1 and ITS4 as primers, followed by restriction enzyme digestion using the endonuclease MvaI. The second method employed a one-step approach employing the repetitive oligonucleotide (GACA)4 as a primer. Dermatophyte strains were also identified using a conventional culture method. Our results showed that the conventional culture method identified four species: Microsporum canis, Trichophyton mentagrophytes, Trichophyton rubrum, and Trichophyton violaceum. Moreover, both PCR methods agreed with the diagnosis made using the conventional approach. Furthermore, ITS1/ITS4-based PCR provided no strain differentiation, while (GACA)4-based PCR identified different varieties among the T. mentagrophytes isolates. Taken together, our results suggest that (GACA)4-based PCR has utility as a simple and rapid method for identification of dermatophyte species as well as utility for differentiation of T. mentagrophytes variants
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