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result(s) for
"Sakai, Hirotaka"
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External validation of the Michigan PICC catheter–associated bloodstream infections score (MPC score) for predicting the risk of peripherally inserted central catheter–associated bloodstream infections: A single-center study in Japan
by
Terasawa, Teruhiko
,
Sakai, Hirotaka
,
Iwata, Mitsunaga
in
Calibration
,
Catheter-Related Infections
,
Catheter-Related Infections - diagnosis
2023
The Michigan peripherally inserted central catheter–associated bloodstream infection score (MPC score) had been developed for hospitalized medical patients but had not been externally validated. A retrospective analysis of a clinically heterogeneous case-mix in a university hospital cohort in Japan failed to validate its originally reported good performance.
Journal Article
Discriminability of selected periods III‒IV elements in photon-counting computed tomography using a pixelated CdTe detector
by
Sakai, Hirotaka
,
Nakasone, Shunya
,
Yoshii, Taiki
in
639/301/930/2735
,
639/4077/4091/4094
,
639/766/930/2735
2025
This study introduces a new approach in photon-counting computed tomography (CT) for elemental discrimination in periods III and IV of the periodic table of elements, which have not been covered by conventional methods that rely on the K-absorption edge of the target element. The present method features a pixelated CdTe detector with positional sensitivity and energy resolution. The authors changed its energy threshold level to determine the worthiness of counting an energy deposition by an X-ray photon in a pixel rather than changing the tube voltage in accordance with the target element as in the conventional method. The differences between the images are visualised on a scatter plot against various threshold levels, which clearly separates iron (atomic number 26) and copper (atomic number 29) with minimal overlap after normalising the CT values of aluminium and air to 0 and −1000, respectively. The discriminability was quantified using the Bhattacharyya coefficient. This elemental discrimination method does not rely on the K-absorption edge of the target element and can therefore be broadly applied to other elements in non-destructive (non-invasive) industrial and biomedical CT inspections.
Journal Article
Chronic neutrophilic leukemia preceded by myelodysplastic syndromes
2023
Chronic neutrophilic leukemia (CNL) is primarily diagnosed by excluding myelodysplastic syndromes (MDS). We report the case of a patient who developed secondary CNL 3 years after hypoplastic MDS. We used droplet digital polymerase chain reaction mutation detection assay to analyze genomic alterations during the progression from MDS to CNL. At the time of MDS diagnosis,
U2AF1
Q157P and
SETBP1
D868N were dominant and additional mutation of
ASXL1
1934_insG was observed.
CSF3R
T618I and
SETBP1
D868N were increasing at the time of CNL diagnosis. We revealed the accumulation of multiple gene mutations during CNL development from MDS. This suggests that CNL was clonally developed from the founding clone of MDS and
CSF3R
mutation contributes to the development of CNL in the present case. These findings provide insights into the pathology of CNL.
Journal Article
Light-chain plasma cell myeloma caused by 14q32/IGH translocation and loss of the other allele
2019
Light-chain plasma cell myeloma (LC-PCM) is a PCM subtype in which only immunoglobulin light-chain is secreted. However, the absence of immunoglobulin heavy-chain (IGH) production in this condition has not been fully elucidated. To address this issue, we retrospectively analyzed patients at our center with LC-PCM and found a group who had only split signals of IGH gene derived from 14q32/IGH translocations by fluorescence in situ hybridization (FISH). Six patients were identified with only split signals of the IGH gene derived from 14q32/IGH translocations. Five of these patients were newly diagnosed, while one had IgG-λ PCM at presentation, which transformed to λ LC-PCM after treatment. The translocation partners were identified in four patients: two cases of (11;14)(q13;q32) and two cases of (4;14)(p16;q32). The development of LC-PCM appears to be explained by the application of allelic exclusion in these patients, such that 14q32/IGH translocation in one allele contributes to the pathogenesis of PCM and the subsequent loss of the other allele is responsible for the loss of IGH production. These findings suggest that a FISH pattern of IGH with “split and loss” may constitute a unique subgroup of LC-PCM.
Journal Article
Expression of activating natural killer‐cell receptors is a hallmark of the innate‐like T‐cell neoplasm in peripheral T‐cell lymphomas
by
Isobe, Yasushi
,
Sakai, Hirotaka
,
Takagi, Masayuki
in
Adult
,
Aged
,
Anaplastic large-cell lymphoma
2018
Peripheral T‐ or natural killer (NK)‐cell lymphomas are rare and difficult‐to‐recognize diseases. It remains arduous to distinguish between NK cell‐ and cytotoxic T‐lymphocyte‐derived lymphomas through routine histological evaluation. To clarify the cells of origin, we focused on NK‐cell receptors and examined the expression using immunohistochemistry in 22 cases with T‐ and NK‐cell neoplasms comprising angioimmunoblastic T‐cell lymphoma, anaplastic lymphoma kinase (ALK)‐positive and ‐negative anaplastic large‐cell lymphomas, extranodal NK/T‐cell lymphoma, nasal type, monomorphic epitheliotropic intestinal T‐cell lymphoma, aggressive NK‐cell leukemia, and other peripheral T‐cell lymphomas. Inhibitory receptor leukocyte immunoglobulin‐like receptor subfamily B member 1 (LILRB1) was detected in 14 (64%) cases, whereas activating receptors DNAM1, NKp46, and NKG2D were expressed in 7 (32%), 9 (41%), and 5 (23%) cases, respectively. Although LILRB1 was detected regardless of the disease entity, the activating NK‐cell receptors were expressed predominantly in TIA‐1‐positive neoplasms (DNAM1, 49%; NKp46, 69%; and NKG2D, 38%). In addition, NKp46 and NKG2D were detected only in NK‐cell neoplasms and cytotoxic T‐lymphocyte‐derived lymphomas including monomorphic epitheliotropic intestinal T‐cell lymphoma. One Epstein‐Barr virus‐harboring cytotoxic T‐lymphocyte‐derived lymphoma mimicking extranodal NK/T‐cell lymphoma, nasal type lacked these NK‐cell receptors, indicating different cell origin from NK and innate‐like T cells. Furthermore, NKG2D expression showed a negative impact on survival among the 22 examined cases, which mainly received the standard chemotherapy regimen (log‐rank test, P = .024). We propose that the presence of activating NK‐cell receptors may provide new insights into understanding peripheral T‐cell lymphomas and characterizing them as innate‐like T‐cell neoplasm. It remains difficult to distinguish between NK‐cell‐ and cytotoxic T‐lymphocyte‐derived lymphomas through routine histological evaluation. Cytotoxic T‐lymphocyte‐derived lymphomas are characterized as innate‐like T‐cell neoplasms by the expression of activating NK‐cell receptors. NKG2D expression might show a negative impact on survival in T‐ and NK‐cell lymphoma cases receiving the standard CHOP‐like regimen.
Journal Article
Cell dynamics during differentiation therapy with all-trans retinoic acid in acute promyelocytic leukemia
by
Inoue, Yasuyuki
,
Tomita, Naoto
,
Sakai, Hirotaka
in
Acute promyeloid leukemia
,
Differentiation
,
Fluorescence
2018
The introduction of all-trans retinoic acid (ATRA) has made acute promyelocytic leukemia (APL) a curable disease; however, early death prior to the completion of treatment remains a problem. In quantitative evaluation of response to ATRA treatment, lymphocytes must be excluded as they do not originally have t(15;17). We categorized peripheral blood leukocytes by nuclear morphology into polymorphonuclear cells (PMNs) comprising segmented granulocytes, and non-polymorphonuclear cells (NPMs) which includes lymphocytes, monocytes, band cells, and immature myeloid cells. We consecutively evaluated the ratio of t(15;17)-positive cells using fluorescence in situ hybridization in eight newly diagnosed patients with APL. We confirmed the differentiation of APL cells until cytogenetic complete remission; the association of a decrease of t(15;17)-positive NPMs and an increase of t(15;17)-positive PMNs was followed by a decrease of t(15;17)-positive PMNs. The kinetic pattern of t(15;17)-positive NPMs and PMNs was consistent in most patients, irrespective of leukocyte counts at diagnosis, additional chromosomal changes, and ATRA with or without chemotherapies. Kinetic analysis enables us to evaluate treatment response and the recovery of normal hematopoiesis in individuals.
Journal Article
PAX5-positive plasma cell myeloma with t(9;14;11)(p13;q32;q13), a novel complex variant translocation of t(11;14)(q13;q32) and t(9;14)(p13;q32)
by
Inoue, Yasuyuki
,
Sakai, Hirotaka
,
Isobe, Yasushi
in
Case Report
,
Chromosome Banding
,
Chromosomes, Human, Pair 11 - genetics
2015
We describe herein the case of a 64-year-old man with a diagnosis of plasma cell myeloma (PCM). A chromosome analysis based on G-banding and spectral karyotyping revealed the following complex karyotype: 46,XY,del(3)(p?), t(4;15)(q31;q24),t(9;14;11)(p13;q32;q13),add(15)(q24),add(18)(q21). Fluorescence in situ hybridization (FISH) detected one signal each for the immunoglobulin heavy chain (IGH) and
cyclin D1
(
CCND1
) genes, and three fusion signals of
IGH
and
CCND1
. FISH analysis of metaphase spreads revealed fusion signals on the derivative chromosomes 9, 11, and 14. Immunohistochemical analysis identified abnormal expression of
CCND1
and
PAX5
. PAX5-positive PCM is rare because the down-regulation of
PAX5
is essential for the terminal differentiation of B cells into plasma cells. To the best of our knowledge, this is the first reported case of a novel complex variant translocation of t(11;14)(q13;q32) and t(9;14)(p13;q32).
Journal Article
Curative Effects for B-Cell Lymphoma Accomplished by Direct-Acting Antiviral Agents of Hepatitis C
2017
Hepatitis C virus (HCV) is a hepatotropic and lymphotropic virus with the capabilities of tumorigenesis. We present an HCV-infected patient affected with B-cell lymphomas after suffering from hepatocellular carcinoma. The patient exhibited curative effects for lymphomas after treatment with sofosbuvir and ledipasvir, which is shown clearly with a positron emission tomography scanner.
Journal Article
Stress-chain based micromechanics of sand with grain shape effect
by
Fukuma, Masatoshi
,
Maeda, Kenichi
,
Sakai, Hirotaka
in
Anisotropy
,
Complex Fluids and Microfluidics
,
Density
2010
The mechanical behaviors of granular media are controlled by grain properties and microstructure. The primary property of granular media is denoted by its grain shape, grain size distribution, stiffness, and interparticle friction. The grain shape itself is of particular importance. Microstructures are formed in the connection paths of contact points between grains. In this paper, the deformation of granular materials with different grain shapes was simulated using two-dimensional DEM under different stress-levels and densities. After analyzing the results, the authors investigated fabric changes. The evolution rule of stress-induced anisotropy and its limitation as well as the existence of a critical state of fabric are revealed.
Journal Article
De novo acute lymphoblastic leukemia-like disease of high grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements: a case report and literature review
by
Isobe, Yasushi
,
Sakai, Hirotaka
,
Otsubo, Kaori
in
Acute lymphocytic leukemia
,
Case Report
,
Development and progression
2017
Background
B-cell lymphomas harboring the 8q24/
MYC
plus 18q21/
BCL2
translocations are now referred to as high grade B-cell lymphoma with
MYC
and
BCL2
and/or
BCL6
rearrangements (HGBL-MBR). Although HGBL-MBR is frequently found in cases with diffuse large B-cell lymphoma or Burkitt lymphoma-like B-cell lymphoma, acute lymphoblastic leukemia (ALL)-like disease of HGBL-MBR (AL-HGBL-MBR) has been reported incidentally.
Case presentation
A 69-year-old Japanese woman developed remittent fever and increasing systemic bone pain. The bone marrow examination revealed that more than 90% of nuclear cells were blastoid cells, which were positive for CD10, CD19, CD20, and surface IgMκ and negative for terminal deoxynucleotidyl transferase (TdT). Cytogenetic studies confirmed that the patient had de novo AL-HGBL-MBR with the extra copies of
MYC
and loss of chromosome 17p. She showed resistance to chemoimmunotherapy and died seven months after the diagnosis. The literature review identified further 47 de novo AL-HGBL-MBR cases within the last 32 years. The median age was 61 years (range, 27 − 86); the male/female ratio was 2.0. Thirty-eight cases (79%) presented a clinical picture of ALL at diagnosis; 14 (36%) of 39 available cases showed central nervous system involvement. Loss of 17p and translocations at 2p12–13, 3q27, 9p13 were frequently observed as additional cytogenetic abnormalities. Although the median survival of 46 available cases was only five months (range, 0.1–18), rituximab use significantly improved the survival of AL-HGBL-MBR (log-rank test,
P
= 0.0294).
Conclusion
Our patient and most reported de novo AL-HGBL-MBR cases showed resistance to conventional chemoimmunotherapy and disastrous consequences. AL-HGBL-MBL is a rare, but should be considered a distinct clinical condition in HGBL-MBR. Other therapeutic strategies, such as using inhibitors of MYC and BCL2, are needed to overcome the chemoresistance of AL-HGBL-MBR.
Journal Article