Molecular analysis of relapse in chronic myeloid leukemia after allogeneic bone marrow transplantation

Four patients with Philadelphia (Ph') positive chronic myeloid leukemia (CML) were studied before, after, and on relapse following allogeneic bone marrow transplantation (BMT). Southern analysis of DNA from cells collected before and at relapse after BMT was performed in order to investigate the origin of the leukemia at relapse. Using minisatellite probes we showed that the relapse occurred in cells of host origin in all four patients and this was confirmed with a Y chromosome specific probe in two male patients who had a female donor. Furthermore, using two probes for the breakpoint cluster region (bcr) on chromosome 22, we showed that leukemic cells at relapse bore identical rearrangements to those in the disease at time of presentation of each patient. We conclude that relapse in all four patients is due to re-emergence of the original leukemic clone.     

Site‐Specific Labeling of Proteins and Peptides with Trans‐cyclooctene Containing Handles Capable of Tetrazine Ligation

There is a growing library of functionalized non‐natural substrates for the enzyme protein farnesyltransferase (PFTase). PFTase covalently attaches these functionalized non‐natural substrates to proteins ending in the sequence CAAX, where C is a cysteine that becomes alkylated, A represents an aliphatic amino acid, and X is Ser, Met, Ala, or Gln. Reported substrates include a variety of functionalities that allow modified proteins to undergo subsequent bioconjugation reactions. To date the most common strategy used in this approach has been copper catalyzed azide‐alkyne cycloaddition (CuAAC). While being fast and bioorthogonal CuAAC has limited use in live cell experiments due to copper's toxicity.¹ Here, we report the synthesis of trans‐cyclooctene geranyl diphosphate. This substrate can be synthesized from geraniol in six steps and be enzymatically transferred to peptides and proteins that end in a CAAX sequence. Proteins and peptides site‐specially modified with trans‐cyclooctene geranyl diphosphate were subsequently targeted for further modification via tetrazine ligation. As tetrazine ligation is bioorthogonal, fast, and is contingent on ring strain rather than the addition of a copper catalyst, this labeling strategy should prove useful for labeling proteins where the presence of copper may hinder solubility or biological reactivity.     

Synthesis of diagnostic quality cancer pathology images by generative adversarial networks

Deep learning-based computer vision methods have recently made remarkable breakthroughs in the analysis and classification of cancer pathology images. However, there has been relatively little investigation of the utility of deep neural networks to synthesize medical images. In this study, we evaluated the efficacy of generative adversarial networks to synthesize high-resolution pathology images of 10 histological types of cancer, including five cancer types from The Cancer Genome Atlas and the five major histological subtypes of ovarian carcinoma. The quality of these images was assessed using a comprehensive survey of board-certified pathologists (n = 9) and pathology trainees (n = 6). Our results show that the real and synthetic images are classified by histotype with comparable accuracies and the synthetic images are visually indistinguishable from real images. Furthermore, we trained deep convolutional neural networks to diagnose the different cancer types and determined that the synthetic images perform as well as additional real images when used to supplement a small training set. These findings have important applications in proficiency testing of medical practitioners and quality assurance in clinical laboratories. Furthermore, training of computer-aided diagnostic systems can benefit from synthetic images where labeled datasets are limited (e.g. rare cancers). We have created a publicly available website where clinicians and researchers can attempt questions from the image survey ( http://gan.aimlab.ca/ ). © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Placebo effect in burning mouth syndrome: a systematic review

Placebo controls play a critical role in the evaluation of any pharmacotherapy. This review surveys the placebo arm in 12 randomized controlled trials (RCTs) investigating burning mouth syndrome (BMS) and documents a positive placebo response in 6 of them. On average, treatment with placebos produced a response that was 72% as large as the response to active drugs. The lack of homogeneity in the use of placebos adds to the difficulty in comparing results and aggregating data. Future RCTs investigating BMS would benefit from larger sample sizes, adequate follow‐up periods, and use of a standard placebo.     

Antimicrobial Activities of Skincare Preparations from Plant Extracts

In this study, Tithonia diversifolia Helms. (A Gray), Aloe secundiflora (Miller) and Azadirachta indica (A. Juss) plant extracts were used to make herbal soaps while Thevetia peruviana (Schum) seed oil was used to make a herbal lotion for skincare. The soaps were tested for the growth inhibition of Escherichia coli, and Candida albicans. The lotion was evaluated against Staphylococcus aureus and E.coli. Although Tithonia diversifolia soap exhibited the highest inhibitory effect on the test bacterial strains, it had the least inhibition against C. albicans. Results from this study indicated that the ‘Tithonia diversifolia’ soap would have superior skin protection against the tested bacteria but would offer the least skin protection against C. albicans. The herbal lotion inhibited S. aureus and E. coli in a concentration dependent manner, however, the inhibitory effect was more pronounced on S. aureus.     

人骨髓间充质干细胞分离培养及血管内皮生长因子对其产生的诱导分化作用

目的：目前有关骨髓间充质干细胞向内皮细胞诱导分化的研究较少。本实验分离和培养人骨髓间充质干细胞，用带有VEGF165的质粒转染人骨髓间充质干细胞，探讨血管内皮生长因子对其体外诱导分化的作用。 方法：实验于2005—04／2006—04在吉林大学人兽共患病教育部重点实验室完成。取成人的已排除血液系统肿瘤疾病的新鲜骨髓（自愿提供），采用Percoll梯度分离培养骨髓间充质干细胞，于倒置显微镜下观察细胞形态变化和生长情况。原代细胞培养至增殖接近融合状态时，单克隆培养法分离传代培养，扩增骨髓间充质干细胞。采用流式细胞术检测细胞免疫学表型。在原核细胞大肠杆菌DH5α中复制扩增和提取，纯化、克隆pcDNA3．0-VEGF165质粒。用脂质体转染法转染骨髓间充质干细胞：应用流式细胞术检测诱导后骨髓间充质干细胞免疫学表型变化j并采用免疫荧光染色鉴定转染情况，并设质粒空载和未转染的骨髓间充质干细胞为对照。 结果：人骨髓间充质干细胞原代培养1周后，造血细胞消失，贴壁细胞体积增大，呈现梭形外观，有粗大的细胞突起伸出。2周后细胞融合成单层，梭形突起变长，排列有明显的方向性，细胞排列成旋涡状、网状、辐射状。流式细胞术显示，人骨髓间充质干细胞免疫学表型CD44、CD29阳性，CD34、CD31、CD45阴性。VEGF165诱导骨髓间充质千细胞后CD44表达明显降低，CD31明显升高。免疫荧光染色显示，用FITC标记后的VEGF抗体使细胞显现绿色荧光，用cy3标记的CD31抗体使细胞显现了红色荧光。 结论：转染后的骨髓间充质干细胞细胞表型发生明显转变，CD31表达率明显增高，呈现典型的内皮细胞的表型特征，这说明骨髓间充质干细胞具有向内皮细胞分化的潜能。     

Microlaryngeal surgery on a day case basis

The aim of this study was to assess the clinical safety of performing microlaryngeal surgery (MLS) under general anaesthesia in selected patients in the ambulatory setting. Twenty-two adult patients were scheduled to have tissue specimens of the larynx taken by biopsy (54%), for vocal cord polypectomy (41%) or for vocal cord cyst excision (5%). Twenty-one ASA I and II patients (95%) were discharged home the same day of the procedure. Two of them presented with laryngospasm after extubation of the trachea. One ASA III patient (5%) had to be admitted overnight because of severe laryngospasm and bronchospasm, but was discharged the day after the operation. None of the patients had significant complications after leaving the recovery room (mean stay 85 min). There were no re-admissions to the hospital. Our data suggests that microlaryngeal surgery in selected patients can be safely performed on a day case basis.