Publications by authors named "M Takagi"

2,755 Publications

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Genetic features of B-cell lymphoblastic lymphoma with TCF3-PBX1.

Cancer Rep (Hoboken) 2021 Sep 23:e1559. Epub 2021 Sep 23.

Department of Pediatric Hematology and Oncology Research, National Research Institute for Child Health and Development, Tokyo, Japan.

Background: Lymphoblastic lymphoma (LBL) and acute lymphoblastic leukemia (ALL) are categorized as the same entity under precursor lymphoid neoplasms in the World Health Organization classification. However, compared to B-cell ALL, the molecular genetic makeup of B-cell LBL remains to be understood, mainly due to its rarity. We performed whole exome sequencing (WES) on seven patients with TCF3-PBX1-positive B-cell LBL.

Methods: WES was performed using DNA extracted from tumor specimens and paired blood samples at remission for six patients, and tumor-only analysis was performed for one patient whose remission sample was not available. For one patient, a relapsed sample was also analyzed.

Results: KMT2D variants and 6q LOH were found as recurrent alterations. Somatic variants of KMT2D were identified in three of the seven patients. Of note, the two patients with heterozygous nonsense variant of KMT2D were at stage III, without bone marrow infiltration. 6q LOH was also identified in two others, out of the seven patients. The common 6q deleted region of the two patients ranged from 6q12 to 6q16.3. Both patients had bone marrow infiltration. Analysis of recurrent case also revealed that the relapsed clone might be derived from a minor clone of the bone marrow at diagnosis.

Conclusion: In this study, through WES for seven patients with TCF3-PBX1-positive B-LBL, we identified KMT2D mutations and 6q LOH as recurrent alterations. In order to elucidate the relationship between these recurrent alterations and disease specificity or outcomes, further studies comparing with TCF3-PBX1-positive B-ALL are required.
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September 2021

Assessment of the severity of curly toe.

J Orthop Sci 2021 Sep 6. Epub 2021 Sep 6.

Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, 2-2-2, Iida-Nishi, Yamagata, Japan.

Background: Curly/underlapping toe involves flexion, adduction, and varus deformity of the interphalangeal joints. There are no previous reports showing the relationship between physical examination and X-ray findings among patients with curly toe deformity.

Methods: We investigated the clinical findings of 116 consecutive patients associated with 239 underlapping toes. We compared the age and affected toes between patients whose deformities were pointed out at a pediatric medical examination (group 1) and those referred for medical treatment (group 2). The degree of curly toe deformity was graded by a physical examination and X-ray.

Results: The average age at presentation was 2.7 years. The affected toes were significantly different between groups 1 and 2 (p < .001). The morbidity of each toe differed significantly in group 2 (p < .005) but not in group 1. The correlation between the appearance grading and classification by X-ray was very strong using Spearman's rank correlation coefficient. The severity of curly toe was divided into mild in 104 toes, moderate in 105 toes, and severe in 17 toes. The methods of conservative treatment were observation only in 15 cases, manipulations in 30 cases, taping in 67 cases, and a brace in 9 cases. Surgery was performed in 8% of cases.

Conclusion: Curly toe deformity of the third or fourth toes tend to be referred for medical treatment because of the abnormality. Our grading system using a physical examination and classification by X-ray was useful for assessing the severity of curly toe.
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September 2021

Staging of Osteochondritis Dissecans of the Elbow Based on Pathological Progression in the Partially Detached Articular Fragment.

J Shoulder Elbow Surg 2021 Aug 31. Epub 2021 Aug 31.

Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Yamagata, Japan.

Background: Osteochondritis dissecans (OCD) is considered to show the following stages of pathological progression: IA, nearly normal-cartilaginous; IB, deteriorated-cartilaginous; IIA, cartilage-ossifying; and IIB, cartilage-osteonecrotic. However, the validity of this pathological staging for OCD has yet to be confirmed in a large number of cases.

Purpose: The aim of the present study was to confirm the clinical validity of the proposed pathological staging of OCD.

Methods: The subjects were 74 patients (mean age, 14.2 years; mean skeletal age score, 25.6 points) with capitellar OCD. Partially detached articular fragments were surgically removed, and were examined histologically. The articular fragments were independently assessed by five observers and the reliability of assessment was examined. The correlation between the pathological stages and the clinical data was analyzed.

Results: The reliability of the assessment among five observers was almost perfect. OCD stages of IA, IB, IIA, and IIB were evident in eight, 36, 10, and 20 patients, respectively. OCD-I (cartilaginous) and OCD-II (osteochondral) corresponded significantly to radiographic stage I (radiolucency) and stage II (delayed ossification), respectively. The pathological OCD stages were significantly correlated with the clinical data, including the period from symptom onset to surgery, patient age, and the skeletal age score (p < 0.01).

Conclusion: Our results confirmed that the proposed pathological staging of OCD corresponds to the observed clinical progression of OCD, thus validating the staging system. Our findings revealed that OCD begins with separation beneath the epiphyseal cartilage which is programmed to be replaced with bone. When a stage IA articular fragment has remained partially detached for a prolonged period, the epiphyseal cartilage may be deteriorated and become degenerated, and subsequent ossification may not occur, as is evident in OCD-IB. In contrast, stage IA with a vascular supply through the fibrocartilaginous connection can progress to stage IIA. During the prolonged period in which the osteochondral articular fragment remains un-united, microtrauma can cause to disturb the blood supply to the bony fragment, resulting in osteonecrosis (stage IIB).
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August 2021