Physics, chemistry and astronomy of H3+. Introductory remarks.
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Journal Article↗
Biomedical subjects
Takeshi Oka
Publications and source records attributed to Takeshi Oka.
Deviated VH4 immunoglobulin gene usage is found among thyroid mucosa-associated lymphoid tissue lymphomas, similar to the usage at other sites, but is not found in thyroid diffuse large B-cell lymphomas.
It remains unclear whether or not diffuse large B-cell lymphomas of extranodal sites arise from mucosa-associated lymphoid tissue (MALT) lymphomas. We studied the clinicopathological features of MALT lymphoma and diffuse large B-cell lymphoma in the thyroid gland, with special reference to VH usage of immunoglobulin gene rearrangement, to clarify the relationships between these two types of lymphomas. In addition, t(11; 18) (q21; q21) translocation was examined by multiplex reverse transcription-polymerase chain reaction. We examined 58 patients with primary thyroid lymphoma: 31 (male seven and female 24) with MALT lymphoma and 27 (male three and female 24) with diffuse large B-cell lymphoma. Interestingly, the sequence of VH genes revealed that the two subtypes differed significantly in their use of the VH4 family (P < 0.05). Of the seven MALT lymphomas, three used the VH4 family and the other four used the VH3 family, whereas eight out of nine diffuse large B-cell lymphoma used the VH3 family, one used the VH1 family, and none used the VH4 family. It was also interesting that, in one diffuse large B-cell lymphoma patient with MALT lymphoma, the diffuse large B-cell lymphoma component used the VH3 family and the MALT lymphoma component used the VH4 family. These data imply that, in a subset of cases, these two subtypes do not share a common origin and that at least some diffuse large B-cell lymphomas have a de novo origin. No t(11; 18) (q21; q21) was detected in thyroid lymphomas, which are different from MALT lymphoma of the stomach, lungs, large intestine and ocular adnexa. This strongly indicated that the presence of t(11; 18) (q21; q21) in MALT lymphoma is organ-specific.
Adult↗
Interstellar H(3)(+).
Protonated molecular hydrogen, H(3)(+), is the simplest polyatomic molecule. It is the most abundantly produced interstellar molecule, next only to H(2), although its steady state concentration is low because of its extremely high chemical reactivity. H(3)(+) is a strong acid (proton donor) and initiates chains of ion-molecule reactions in interstellar space thus leading to formation of complex molecules. Here, I summarize the understandings on this fundamental species in interstellar space obtained from our infrared observations since its discovery in 1996 and discuss the recent observations and analyses of H(3)(+) in the Central Molecular Zone near the Galatic center that led to a revelation of a vast amount of warm and diffuse gas existing in the region.
Astronomy↗
Chemistry. Nuclear spin conversion in molecules.
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Comment↗
Near-infrared electronic spectrum of CH2+.
Four vibronic bands of the A 2B1(Piu)<--X 2A1 electronic transition of CH2+ have been observed in the near infrared from approximately 11,000-13,000 cm(-1) using a highly sensitive spectrometer based on a Ti:sapphire laser and a positive column plasma. The two states are derived from the lowest 2Piu state of the linear conformation as a result of a strong Renner-Teller effect. As expected, the rovibronic structure of the CH2+ spectrum is very similar to that of the isoelectronic BH2 radical reported by Herzberg and Johns. Results of a preliminary analysis are given in which the rotational structures of the two states are treated independently, the ground state as a near-prolate asymmetric rotor and the excited state as a linear molecule.
Journal Article↗
High-resolution spectroscopy of the 2(2)Piu<--X4Sigmag- forbidden transitions of C2+.
The electronic absorption spectrum of the (0,2), (1,3), and (6,9) bands of the B4Sigmau(-)-X4Sigmag- system of C2+ was obtained using the velocity modulation technique in conjunction with heterodyne detection. The rotationally resolved spectrum shows perturbations, which are attributed to the 2(2)Piu state. The mixing between the B4Sigmau- state and the 2(2)Piu state for nearly degenerate levels generated enough intensity borrowing to observe twenty 2(2)Piu<--X4Sigmag- forbidden transitions. The parameters of a model Hamiltonian were fit to the bands and their corresponding forbidden transitions. Line position measurements, line strength factors, and expectation values for the orbital angular momentum Lambda' for the forbidden transitions are reported. Molecular parameters from the global fit of each band, including their corresponding forbidden transitions, are reported.
Journal Article↗
Detection of micrometastatic tumor cells in pN0 lymph nodes of patients with completely resected nonsmall cell lung cancer: impact on recurrence and Survival.
OBJECTIVE: To detect occult micrometastatic tumor cells in pN0 lymph nodes of nonsmall cell lung cancer (NSCLC) by a combination of cytokeratin and p53 immunohistochemistry staining, and to evaluate the relation between the micrometastasis in pN0 lymph nodes and the prognosis of patients with completely resected stage 1 NSCLC. SUMMARY BACKGROUND DATA: The average 5-year survival rate for patients with completely resected stage 1 NSCLC is only about 70%; thus, about 30% of these patients have recurrent disease. This suggests that occult micrometastasis may exist at the time of surgery; the rate is clearly underestimated by current clinical staging examinations and conventional histopathologic methods. METHODS: A total of 474 hilar and mediastinal lymph nodes were removed during surgery from 49 patients with completely resected stage 1 NSCLC. The lymph nodes analyzed for micrometastasis using immunohistochemical staining with the biclonal anticytokeratin antibody, AE1/AE3. Of these 474 lymph nodes from 49 patients, 263 lymph nodes from 25 patients, whose primary tumors were positive for the p53 protein, were subjected to immunohistochemical staining with the monoclonal anti-p53 protein antibody DO-1. RESULTS: Cells positive for cytokeratin and p53 protein were found in 35 (7.4%) of 474 and 20 (7.6%) of 263 lymph nodes, respectively; 17 (34.7%) of 49 patients had cytokeratin-positive cells and 10 (40.0%) of 25 patients had p53-positive cells in their pN0 lymph nodes. By a combination of cytokeratin and p53 protein immunohistochemical staining, micrometastatic tumor cells were identified in pN0 lymph nodes in 22 (44.9%) of 49 patients. The patients with lymph node micrometastasis identified by a combination of cytokeratin and p53 protein immunohistochemical staining had a poorer prognosis than those without micrometastasis on both univariate and multivariate analyses (overall survival, P =.0003 and 0.013, respectively). CONCLUSIONS: The detection of lymph nodal micrometastasis by cytokeratin and p53 protein immunohistochemical staining will be helpful to predict the recurrence and prognosis of patients with completely resected stage 1 NSCLC.
Carcinoma, Non-Small-Cell Lung↗