Leukocyte alkaline phosphatase(LAP) is potentially a significant marker for following the maturation sequence of normal and abnormal neutrophils. This enzyme can be localized in the rough endoplasmic reticulum (rer) and in the Golgi complex of immature neutrophils but it has been very difficult to demonstrate LAP activity in the granules of mature neutrophils. This observation presents a dilemma since LAP is present in higher concentrations in mature as opposed to immature neutrophils as demonstrated by biochemical and light microscopy methods. In an attempt to solve this problem, variations on the routine methods for demonstrating LAP activity were explored. Acetone, formaldehyde, methanol and gluteraldehyde were used as fixatives.
Journal Article Observations on Thomsen's Disease Get access W. Johnson, W. Johnson Neurological Department, Guy's Hospital Search for other works by this author on: Oxford Academic PubMed Google Scholar Geoffrey Marshall Geoffrey Marshall Neurological Department, Guy's Hospital Search for other works by this author on: Oxford Academic PubMed Google Scholar QJM: An International Journal of Medicine, Volume os-8, Issue 30, January 1915, Pages 114–128, https://doi.org/10.1093/qjmed/os-8.30.114 Published: 01 January 1915
Abstract Introduction: Neuroblastoma (NB) is a pediatric malignancy arising from peripheral neuronal sympathoblasts and exhibiting remarkable clinical and genetic heterogeneity. Patients older than 18 months have a poor prognosis with tumors presenting with highly recurrent segmental copy number alterations and MYCN amplification in half of these high-risk cases. The mechanism by which MYCN contributes to the development of neuroblastoma is unresolved and direct targeting of this key oncogene is not currently possible. Experimental Procedures: Our discovery efforts focused on identifying cooperating interactors and vulnerabilities in the MYCN regulatory network. MYCN-driven NBs can be modeled in mice with morphologic and genomic features that recapitulate human MYCN amplified NBs. Thus, this model serves as a valid tool for cross-species genomic analysis. Using this model, we performed a time-resolved analysis of the dynamic transcriptional changes of protein coding genes during murine TH-MYCN driven neuroblastoma development, focusing on timepoints representing tumor initiation and early tumor growth. We triangulated expression changes of key genes with publicly available exome-wide CRISPR-cas9 knockout analyses on a panel of human neuroblastoma cell lines and patient survival data. This unique data resource uncovered the relevance of MEIS2 as putative early cooperating initiating factor for neuroblastoma. Analysis of the genome-wide binding profile of MEIS2 in MYCN-amplified NB cell lines showed a striking overlap with enhancer-driven gene expression in regions of open chromatin, providing evidence that MEIS2 is a novel member of the adrenergic neuroblastoma core-regulatory circuitry. CRISPR-Cas9 mediated deletion of MEIS2 in animal models suppresses establishment of neuroblastoma tumors, indicating its putative requirement for tumor initiation. MEIS2, as a member of the CRC binds to several master regulators of gene expression, including the FOXM1 locus. Summary and conclusion: In conclusion, we present an in-depth characterization of the dynamic transcriptome profiles of TH-MYCN driven murine premalignant and established tumors and integrate with both primary human neuroblastoma tumor expression data, epigenetic and functional genomics data to identify and validate candidate cooperating dependencies suitable for targeting as a precision medicine approach in neuroblastoma. Citation Format: Kaat Durinck, Mark Zimmerman, Nina Weichert-Leahey, Jolien Dewyn, Wouter Van Loocke, Carolina Nunes, Anneleen Beckers, Bieke Decaesteker, Pieter-Jan Volders, Christophe Van Neste, Belamy Cheung, Daniel Carter, Thomas A. Look, Glenn Marshall, Katleen De Preter, Adam Durbin, Franki Speleman. Time-resolved transcriptome analysis of murine TH-MYCN driven neuroblastoma identifies MEIS2 as early initiating factor and novel core gene regulatory circuitry constituent [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2481.
Pneumocystis carinii (PC) is an organism capable of causing fatal pneumonia in immune suppressed individuals and has recently gained prominence because of its association with AIDS. A similar organism occurs in rats and infection may be induced with cortisone injections. In order to isolate PC for further study bronchoal veol ar lavage (BAL) was performed. Differences in the ul trastructure of BAL-obtained organisms and PC in situ were observed and are herein reported.
Preoperative and postoperative studies of peripheral B and T lymphocyte counts were accomplished in 21 patients. Diagnoses included 10 carcinoma of the breast, 3 sarcoma, and 8 benign diseases. On postoperative day one and two, an increase in B-cell percentage was observed in the majority of patients tested. However, there was a decrease in total lymphocyte count and fast-reacting T lymphocyte numbers on postoperative day one, especially in patients who had intraabdominal operations. All the lymphocyte counts returned to preoperative range within one week. Pertinent reports in the literature were reviewed and discussed.
Human bone and cartilage specimens were evaluated for acid and alkaline phosphatase localization following varying fixation periods for fresh or frozen tissue. Formalin fixations of up to 183 hr were followed by embedment in methyl methacrylate; frozen tissue was examined either without fixation or following fixation for up to 1 hr and subsequent glycol or methyl methacrylate embedding. The humeral epiphysis of a young patient with osteogenic sarcoma showed optimum acid and alkaline phosphatase localization following fixation for periods up to 15 hr and embedding in methyl methacrylate. Frozen costochondral junction from a newborn with osteogenesis imperfecta type II showed optimum acid and alkaline phosphatase localization following 30 min fixation in formalin and embedding in methyl methacrylate or after 5 min fixation and embedding in glycol methacrylate.
Abstract Introduction: Zero Childhood Cancer’s National Precision Medicine for Children with Cancer Study (PRISM) utilizes novel technologies to guide individualized management of children with high-risk cancer (expected overall survival less than 30%). Germline DNA is utilized to distinguish cancer-specific somatic variants from constitutional variants or polymorphisms, allowing identification of clinically relevant germline mutations. The prevalence of cancer predisposition syndromes in pediatric cancer may range from 8.5% to as high as 33%. Method PRISM combines molecular genomic analysis (WGS and RNASeq) with in vitro high-throughput drug screening and patient-derived xenograft drug efficacy testing. A Molecular Tumour Board (MTB) of Oncology and Genetics professionals convenes to determine the significance of genomic analysis as curated by bioinformaticians, molecular scientists, and clinicians. Results: Between September 2017 and June 2019, 218 children aged under 21 years have been recruited in PRISM (37% with central nervous system tumors, 47% with non-CNS solid tumors, and 16% with hematologic malignancies), and results are available for 208 after discussion at MTB meeting. Forty-two reportable germline variants were detected in 35 participants (detection rate: 16.8%), comprising 28 pathogenic and 14 likely pathogenic variants, across 22 cancer predisposition genes. The most frequently affected gene was CHEK2 (n=7), followed by SMARCB1 (n=5) and BRCA2 (n=3) and NF1 (3). In one out of three participants with germline mutations, somatic analysis revealed a double hit in the same gene altered in the germline. Distributions of participants with germline mutation per group were 16% of patients with CNS tumors (12/77), 19% of patients with non-CNS solid tumors (18/96), and 15% of patients with hematologic malignancies (5/34). Conclusion: Germline mutation detection rate in cancer predisposition genes was higher than expected, 16.8%; however, it may result from selection bias (i.e., cohort of high-risk cancers). Although genomic sequencing has expanded our understanding of pediatric cancer predisposition and presented opportunities for genetics-mediated care, identifying underlying germline mutations with potential clinical implications remains a clinical challenge for pediatric oncologists. Citation Format: Paulette Barahona, Alexandra Sherstyuk, Mark Cowley, Paul Ekert, Judy Kirk, Dong-Anh Khuong-Quang, Amit Kumar, Loretta Lau, Chelsea Mayoh, Glenn Marshall, Emily Moud, Tracey O’Brien, Mark Pinese, David Thomas, Vanessa Tyrell, David Ziegler, Michelle Haber, Katherine Tucker, Noemi Auxiliadora Fuentes-Bolanos, Meera Warby. Prevalence and spectrum of germline mutations in children with high-risk cancer [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr A03.