Nightlife clusters of coronavirus disease in Tokyo between March and April 2020.

We analysed associations between exposure to nightlife businesses and severe acute respiratory syndrome coronavirus 2 PCR test results at a tertiary hospital in Tokyo between March and April 2020. A nightlife group was defined as those who had worked at or visited the businesses. We included 1517 individuals; 196 (12.9%) were categorised as the nightlife group. After propensity score matching, the proportion of positive PCR tests in the nightlife group was significantly higher than that in the non-nightlife group (nightlife, 63.8%; non-nightlife, 23.0%; P < 0.001). An inclusive approach to mitigate risks related to the businesses needs to be identified.

Juvenile migration of the exclusively pelagic cyprinid, Gnathopogon caerulescens (Honmoroko) in Lake Biwa, Central Japan.

Migration of wild and cultivated juvenile honmoroko Gnathopogon caerulescens of from the spawning and nursery areas in Lake Biwa were investigated, both in the Ibanaiko Lagoon and its outlet to Daido River, using beam-trawl surveys in 2013 and 2014. The study demonstrated migration of G. caerulescens from a nursery lagoon toward Lake Biwa after the juvenile stage. These findings appear to be the first direct evidence for migration of an exclusively pelagic cyprinid species from a littoral nursery to a pelagic adult habitat in a large deep lake.

Extensive trans-species mitochondrial polymorphisms in the carabid beetles Carabus subgenus Ohomopterus caused by repeated introgressive hybridization.

To study the potential importance of introgressive hybridization to the evolutionary diversification of a carabid beetle lineage, we studied intraspecific and trans-species polymorphisms in the mitochondrial NADH dehydrogenase subunit 5 (ND5) gene sequence (1083 bp) in four species of the subgenus Ohomopterus (genus Carabus) in central and eastern Honshu, Japan. Of the four species, C. insulicola is parapatric with the other three, and can hybridize naturally with at least two. This species possesses two haplotypes of remote lineages. We classified ND5 haplotypes using polymerase chain reaction-restriction fragment length polymorphism with TaqI endonuclease for 524 specimens, and sequenced 143 samples. Analysis revealed that each species was polyphyletic in its mitochondrial DNA phylogeny, representing a marked case of trans-species polymorphism. Recent one-way introgression of mitochondria from C. arrowianus nakamurai to C. insulicola, and from C. insulicola to C. esakii, was inferred from the frequency of identical sequences between these species and from direct evidence of hybridization in their contact zones. Other intraspecific polymorphisms in the four species may be due to undetected introgressive hybridization (e.g. C. insulicola to C. maiyasanus) or from stochastic lineage sorting of ancestral polymorphisms. This beetle group has a genital lock-and-key system, with species-specific or subspecies-specific genital morphology that may act as a barrier to hybridization. However, our results demonstrate that introgressive hybridization has occurred multiple times, at least for mitochondria, despite differences among, and stability within, morphological characters that distinguish local populations. Thus, hybridization and introgression could have been key processes in the evolutionary diversification of Ohomopterus.

[Morphology and immunophenotyping in hematological malignancies].

We evaluated 443 outpatients and inpatients in Keio University Hospital between 1994 and 1999. Morphologic features from peripheral blood and bone marrow aspiration were evaluated in our hematology laboratory, using Wright-Giemsa, peroxidase staining films and other cytochemistry. Immunophenotype was determined by cell surface antigen analysis by laser flow cytometry, FACscan, using various monoclonal antibodies. Information on cytogenetic and molecular genetic characteristics can be also integrated for diagnosis. One hundred fifty patients were diagnosed with acute leukemia, in which 59 cases were ALL and 91 cases were AML. Seventy-four cases were MDS, 76 cases were myeloproliferative disorders, 21 cases were CLL related disorders, 104 patients were malignant lymphoma, and 18 cases were multiple myeloma. The ratio of male to female was 1.7. The probability of diagnostic rate by Immunophenotyping was estimated by Discriminant analysis in 189 patients, using multivariate analysis of immunophenotype compared to morphology. The average probability by immunophenotypic analysis for diagnostic rate was 91.7%, in which the probability for NHL was very high of 97.1%. Thus, morphologic and immunophenotypic analysis is most essential and basic approach in laboratory hematology, from the perspective of rapid and precise diagnostic methods. Recent advance appreciates the rapid contribution for diagnosis by immunophenotypic analysis. Furthermore, Tele-hematology would contribute the standardization for morphologic method in the near future.

[Multi-parametric analysis for leukemic immunophenotyping].

We have investigated whether immunophenotyping measured by laser flow cytometry could be corresponding to FAB classification of acute leukemias, using multi-parametric analysis. Sixty-one patients with acute leukemias have been evaluated, including 23 patients with acute lymphocytic leukemias (ALL) and 38 patients with acute myelogenous leukemias. In principal component analysis, positive cell surface antigens could be classified into groups along to the cell lineage and differentiation. In discriminant analysis, the sensitivity by immunophenotypic method to FAB subtypes was 75%, whereas the specificity was over 90%. In cluster analysis, patients have been classified into 4 groups, which essentially corresponded to ALL, M1/M2, M3 and M4/M5. Based on those multi-parametric analysis, a new flow chart has been established, resulting that the sensitivity and the specificity was improved to over 90% and 95% respectively. These results suggest that the classification of acute leukemia using the flow chart could be useful tools for diagnosis of subtypes of acute leukemias.

[Leukocyte differentiation by MICRO21 system using neural networking as a type of artificial intelligence].

NeuralVision is a type of artificial intelligence that has the ability to identify specific microscopic objects. The MICRO21 system uses neural networking to analyze the features of blood cells; color, shape, size, and density, just as a technologist would. The basic nucleated blood cell processing procedure of the MICRO21 is divided into three general categories; location, segmentation, and classification. Classification takes place using the Neural Network and is fine tuned during post-processing. We evaluated the performance of the MICRO21 automated differential vs. manual differential method. The intra-assay of leukocyte differentiation by MICRO21 was fairly good in normal samples with normal leukocyte counts. The neutrophils, lymphocytes and eosinophils count correlated well between MICRO21 and visual count. Post-processing was performed after the Neural Network has initially classified the cell, in which the confidence levels of MICRO21 to visual count was 87%. By post-processing, coincidence ratio of cell-by-cell by MICRO21 and visual count has been improved to 97%. Based on the above, MICRO21 is an effective and efficient system for locating, storing and displaying images of white blood cells, in which the technologist could determine specific characteristics of cells in each laboratory. Furthermore, the system may be applied to any blood cell and would be important from the perspective of cytological and morphological analysis, such as blood cells in bone marrow and body fluid, in the future.

Use of amino acid profiles of preterm and term human milks in evaluating scoring patterns for routine protein quality assessment of infant formulas.

Reports on the amino acid composition of human milk vary considerably with respect to concentrations of sulfur amino acids. Often, analyses forego tryptophan determination. A complete analysis of protein and amino acid concentrations was performed on human milk samples (5-10 days postpartum) collected from mothers of preterm (gestations of 25-32 weeks) and term (gestations of > 36 weeks) infants. Careful attention was given to quantitate amino acids such as cysteine and tryptophan, which are vulnerable to acidic hydrolysis conditions. Differences in concentrations of total amino acids (expressed on protein basis) between preterm and term milks were small, despite the higher true protein content of preterm milk versus term milk (19.20 versus 12.60 g/L). The methionine + cyst(e)ine contents of term and preterm milks (3.72-3.84 g/100 g protein) were comparable with those reported in 1991 by the Food and Agricultural Organization/World Health Organization (FAO/WHO) for mature human milk (4.20 g/100 g protein) but higher than those reported in 1991 by the European Commission (2.9 g/100 g protein). The amino acid pattern of human milk obtained in this study confirms that the 1991 FAO/WHO amino acid scoring pattern for predicting protein quality of infant formulas is representative of the amino acid quality of both preterm and term human milks.

[Immunophenotypic analysis of lymphocyte subpopulation and hematological malignancies].

Determination of the human lymphocyte subpopulation selected by immunofluorescence and the phenotypic analysis of hematological malignant cells by laser flow cytometry have become popular and useful tests in various laboratories. However, several lines of evidence have questioned the accuracy and reproducibility of these analysis. We examined the problems of laser flow cytometric analysis to measure the lymphocyte subpopulation and determine the phenotypic expression of hematological malignancies. In lymphocyte subset analysis, no survey has been applied to reveal the accuracy and reproducibility of these tests. We compared the accuracy of gating events and the ratio of lymphocytes using leuco GATE/simul SET analysis to those by manual gate method analysis. We found that there were some patients with SLE in which the accurate lymphocyte subpopulation was difficult to calculate due to the gating of lymphocytes by either method. Furthermore, apparent differences in the lymphocyte population were observed between these methods. In the phenotypic analysis of hematological malignancies, there have been several problems over 30% of the total cells had to be abnormal cells. Second, the malignant cells were difficult to gate unless the information of the size, shape and cellular density were obvious. Third, the phenotype of malignant cells were often different from that of the normal matured cells in the some lineage. However, flow cytometric analysis was useful to determine the cell lineage of peroxidase-negative cells and to diagnose the hybrid leukemia. In summary, the phenotypic analysis using flow cytometry and various monoclonal antibodies are clinically useful tests to diagnose the immunological disorders and hematological malignancies. However, there remain several problems to be solved in the near future.

[Analysis of DNA contents in hematological malignant cells using whole blood lysis method].

The experiments have been undertaken whether DNA contents could be measured using whole blood lysis method by FACScan. Cell population in the phases of G1, S and G2 + M were well analyzed, when we used 3 x 10(6) cells lysed with 0.1% Triton X-100 in 1 ml of phosphate buffered saline, staining with 30 micrograms/ml of propidium iodide (PI) within 30 min after staining with PI. We have further developed cell cycle analysis for cells bearing lineage specific antigens recognized with FITC-conjugated monoclonal antibodies using two color analysis. When we fixed cells with 50% ice-cold ethanol after staining cells with FITC-conjugated antibodies, positive population ratio in these cells have been unchanged before and after fixing for CD3, CD4, CD5, CD8. CD10, CD19, CD14, CD33, and HLA-DR, but CD7 positive cells were markedly decreased after fixing. Using this method, CD41 positive leukemia cells have 3.4% in S phase and 6.8% in G2 + M phase, while CD41 negative cells have 1.8% in S phase and 2.0% in G2 + M phase in a patient with AML: M7, resulting leukemia cells were rich in S phase and G2 + M phase. The similar results were obtained in patients with AML:M2 using CD33 antibodies. During the clinical course, the changes of the blast numbers were well-correlated with changes of S-phase proportion in the patient with AML:M2. Among 47 patients with hematological malignancies in our hospital tested here, only 2 cases with 4.3% of total patients showed to have aneuploidy in malignant cells. One is a patient with non-Hodgkin lymphoma, the other is myelodysplastic syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Low-molecular-weight xylanase from Trichoderma viride.

An endo-1,4-beta-xylanase (1,4-beta-D-xylan xylanohydrolase, EC 3.2.1.8) has been isolated from a commercial preparation of Trichoderma viride. The molecular weight was 22,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the pI value was 9.3. The xylanase was a true xylanase without cellulase activity. When the N-terminal amino acid sequence of the first 50 residues was compared with that of a xylanase from Schizophyllum commune, strong evidence for homology was found, with more than 50% amino acid identity. T. viride xylanase also possessed extensive identity with a proposed amino-terminal consensus sequence of xylanases from bacteria.

Alteration of sodium and potassium mobilization and of adrenal function by long-term ingestion of lead.

Serum sodium concentration was markedly decreased by long-term (12 weeks) ingestion of lead above 5 mg Pb . kg-1 . day-1, whereas serum potassium concentration was notably decreased by the long-term (12 weeks) ingestion of lead above 2 mg Pb . kg-1. Urinary sodium and potassium in fasted rats were increased markedly 24 hr after a single lead dose (200 mg Pb/kg, o.p.) [Y. Suketa, S. Hasegawa and T. Yamamoto, Toxic. appl. Pharmac. 47, 203 (1979)]. In contrast, urinary excretion of sodium or potassium in non-fasted rats was not changed significantly by 2 weeks of lead ingestion at 200 mg Pb . kg-1 . day-1. Renal activities of Na+, K+-ATPase and K+-dependent phosphatase were decreased to 50-70% of control values by long-term (12 weeks) ingestion of lead (above 5 mg Pb . kg-1 . day-1).

The K+-and HCO3-stimulated phosphatase activities in renal microsomes of rats.

The K+-stimulated phosphatase activity of microsomes from rat kidney was not inhibited by L-phenylalanine, but the HCO3-stimulated phosphatase activity was markedly inhibited by L-phenylalanine. Valinomycin enhanced the HCO3-stimulated phosphatase activity, but did not enhance the K+-stimulated phosphatase activity. Ouabain did not inhibit the HCO3-stimulated phosphatase activity, but inhibited the K+-stimulated phosphatase activity. The renal K+-stimulated phosphatase activity was suppressed to 40% of the control values by adrenalectomy, but the renal HCO3-stimulated phosphatase activity was little suppressed by adrenalectomy. The renal K+-stimulated phosphatase activity in intact and adrenalectomized rats was found to be significantly elevated, in a manner similar to the elevation of the renal (Na+ + K+)-ATPase activity by aldosterone treatment (P less than 0.02).