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Biomedical subjects

N Mohri

Publications and source records attributed to N Mohri.

At least 37 records · Page 2Linked to original sources
PubMed1990

In vitro effects of methylsulfonyl polychlorinated biphenyls and 7,8-benzoflavone on aryl hydrocarbon hydroxylase activity in human lymphoblastoid cells.

The effects of 11 isomers of methylsulfonyl polychlorinated biphenyls (MSF-PCBs) on the aryl hydrocarbon hydroxylase (AHH) activity were examined at a fixed dose of 1.5 micrograms/ml by using cultured lymphoblastoid cells. One of the isomers 3-MSF-3',4,4',5-tetraCB, as well as 4-MSF-3,3',4',5-tetraCB and 4-MSF-3,3',4',5,5'-pentaCB, effectively reduced the AHH activity when added to the culture medium, especially that previously treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to induce the AHH activity. However, the inhibitory potencies exerted by the above three MSF-PCB compounds were smaller than that by 7,8-benzoflavone (BNF). When added to the culture medium simultaneously with TCDD or 3-methylcholanthrene (MC), 3-MSF-3',4,4',5-tetraCB blocked the enhancement of the AHH activity by TCDD but did not that by MC. This is in contrast to BNF which blocked the increases due to both TCDD and MC. On the other hand, 3-MSF-3',4,4',5-tetraCB added directly to the reaction mixture for the TCDD-induced AHH activity showed little influence, while BNF decreased the same activity. These results imply that the effect of 3-MSF-3',4,4',5-tetraCB on the AHH activity is different from that of BNF.

Aryl Hydrocarbon Hydroxylases↗
PubMed1990

[A pathological study of primary malignant lymphomas of the thyroid].

Thirty cases of a primary malignant lymphoma (ML) have been studied clinicopathologically and immunohistochemically. The average age of the patients was 59.1 years, and the ratio of males to females was 1:1.7. According to the Kiel classification of MLs, 53.3% had a low grade malignancy and 46.7% were a high grade malignancy. Therefore, the number with a low or a high grade malignancy was almost equal. Most of the low grade malignancies were ML, centroblastic centrocytic, and most of the high grade malignancies were ML, lymphoblastic. From histopathological and immunohistochemical studies, most cases were considered to be of B-cell origin and two thirds of the cases were regarded as being of a follicular center cell origin. Prognosis was better than that of other MLs. Finally, MLs of the thyroid were found combined more frequently with chronic thyroiditis of the Hashimoto type than malignant epithelial neoplasms.

Adult↗
PubMed1989

[Effects of 3-methylsulphonyl-4,5,3',4-tetrachlorobiphenyl and 7,8-benzoflavone on aryl hydrocarbon hydroxylase activity].

First, we examined the effects of 3-methylsulphonyl-4,5,3',4',-tetrachlorobiphenyl (3-MSF-TCB, 1.5 ppm) and 7,8-benzoflavone (ANF, 1.4 ppm) on aryl hydrocarbon hydroxylase (AHH) activity in cultured human lymphoblastoid cells and we have obtained the following results: (1) 3-MSF-TCB preferentially inhibited the enzyme activity induced by 2,3,4,7,8-pentachlorodibenzofuran (PenCDF) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and slightly stimulated the enzyme activity induced by 3-methylcholanthrene (MC). (2) ANF reduced well the AHH activities induced by all the three enzyme inducers and more strongly inhibited the PenCDF- or TCDD-induced enzyme activity (about 89%). (3) About 64 and 76% of basal (uninduced) AHH activity was lowered by 3-MSF-TCB and ANF, respectively. Second, we investigated the effect of 3-MSF-TCB (1.5-45 ppm) and ANF (1.4-42 ppm) on AHH activity of hepatic microsomes from the Ah nonresponsive (DDD) and responsive (C3H) strains of mice and we have got the following results: (1) 3-MSF-TCB and ANF enhanced or reduced the enzyme activity depending on both their concentrations and kinds of microsomes, namely, those prepared from untreated mice (control-microsomes) and mice treated with MC (MC-microsomes) or TCDD (TCDD-microsomes). (2) ANF showed higher potency for both the enhancement and the inhibition of the enzyme activity than 3-MSF-TCB. (3) The AHH activity of TCDD-microsomes seemed to be more greatly reduced with either 3-MSF-TCB or ANF than that of MC-microsomes. (4) The effects of 3-MSF-TCB and ANF on the enzyme activity of MC-microsomes of DDD mice and of control-microsomes of C3H mice.

Animals↗
PubMed1989

Clinicopathology of non-neoplastic and neoplastic lymph node swelling.

Lymph node swelling, which can be problematic when attempting differential diagnosis between non-neoplastic or neoplastic types, can be grouped into three categories. The first is lymph node swelling due to heterotopia, hamartoma or hyperplasia, the second is due to non-neoplastic lymphoid cell and/or histiocyte proliferation with the appearance of neoplastic proliferation and the third is due to true neoplastic proliferation, but apparently simulating a non-neoplastic condition. The present paper describes some of the clinicopathological features of representative diseases or cases in each category, e.g. Castleman's disease, necrotizing lymphadenitis, "IBL"-like T-cell lymphoma, and lymphoma showing an unusual course initially simulating a non-neoplastic process and then gradually disclosing its neoplastic nature in the late stage. These cases emphasize the importance of close collaboration between the clinician and pathologist together with immunohistochemical studies of lymph node pathology.

Adolescent↗
PubMed1989

[Effects of dioxin congeners on aryl hydrocarbon hydroxylase activity].

In this study, we examined the effect of 1,3,6,8-tetrachlorodibenzo-p-dioxin (1,3,6,8-TCDD), octachlorodibenzo-p-dioxin (OCDD) and 2,4,6,8-tetrachlorodibenzofuran (2,4,6,8-TCDF) on aryl hydrocarbon hydroxylase (AHH) activity in cultured human lymphoblastoid cells. These compounds are considered to be no or less toxic isomers of polychlorinated dibenzo-p-dioxins (Dioxins) and polychlorinated dibenzofurans (Dibenzofurans). At a concentration of 90 ppb, 1,3,6,8-TCDD induced the enzyme activity about 2 times over the basal (untreated) AHH activity and 2,4,6,8-TCDF reduced the basal enzyme activity by about 40%. At a concentration of 5 ppb, OCDD enhanced the basal AHH activity by about 30%. In case of simultaneous treatment of 1,3,6,8-TCDD, OCDD or 2,4,6,8-TCDF with highly toxic 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), at a concentration of 7.5 ppb of each compound, the AHH activities induced by 1,3,6,8-TCDD plus 2,3,7,8-TCDD and OCDD plus 2,3,7,8-TCDD were about 25% and 43%, respectively, higher than that induced by 2,3,7,8-TCDD alone. On the contrary, at the same concentration, the enzyme activity treated with 2,4,6,8-TCDF plus 2,3,7,8-TCDD were about 30% less than that treated with 2,3,7,8-TCDD alone. It has been reported that the AHH inducibility of Dioxins and Dibenzofurans correlates well with their toxic potency. Hence, taking the results of this study into account, we should clarify the biological and/or health consequences of the mixed contamination of no or less toxic and highly toxic congeners of Dioxins and Dibenzofurans by animal experiments and epidemiological studies.

Aryl Hydrocarbon Hydroxylases↗
PubMed1988

Proton NMR resonance assignments and surface accessibility of tryptophan residues of a dimeric phospholipase A2 from Trimeresurus flavoviridis.

Proton NMR spectra of a dimeric phospholipase A2 from Trimeresurus flavoviridis have been recorded. N-1 proton resonances of the tryptophan indole rings have been detected and assigned to specific positions, Trp-3/Trp-30, Trp-68 and Trp-108, by comparing the spectra of the enzyme derivatives with tryptophans oxidized to differing extents. Photo-CIDNP experiments have revealed that Trp-68 and Trp-108 are exposed while Trp-3 and Trp-30 are buried in the molecule. This is consistent with the X-ray crystal structure of a homologous phospholipase A2 from Crotalus atrox where residues 3 and 30 are located at a dimer interface, but inconsistent with the results of stepwise oxidation of tryptophan residues.

Macromolecular Substances↗
PubMed1988

A case report of "lipomatous hypertrophy of the cardiac interatrial septum", with a proposal for a new term "lipomatous hamartoma of the cardiac atrial septum".

An autopsy case of "lipomatous hypertrophy of the cardiac interatrial septum" (LHIS) combined with marked stenosis and calcification of the aortic and mitral valves due to fibrous valvular endocarditis, malignant lymphoma, and mucin-producing cancer of the pancreas is reported. LHIS and mucin-producing cancer of the pancreas were incidental findings at autopsy. Microscopically, the LHIS in this case consisted of proliferation of mature fat cells, brown fat cells and cardiac muscle cells. Since these three cell types are normal structural components of the interatrial septum, it was considered that the LHIS was a hamartomatous rather than hypertrophic lesion, of the cardiac atrial septum. Accordingly it was concluded that the term "lipomatous hamartoma of the cardiac atrial septum" was more appropriate for this lesion in the case presented here. As far as we know, this is the first reported case of LHIS in Japan.

Aged↗
PubMed1988

Rhabdomyosarcoma with bone marrow metastasis simulating acute leukemia. Report of two cases.

Rhabdomyosarcoma manifested as a systemic disease is very rare and cases showing diffuse metastasis in the bone marrow are most unusual. Recently we encountered two cases of rhabdomyosarcoma with diffuse bone marrow metastasis which were clinically manifested as acute leukemia. The first patient was a 15-year-old female, who was admitted in 1982 with pancytopenia and many large primitive cells in bone marrow aspirates, hematological malignancy being diagnosed. Thereafter the bilateral breasts showed rapid swelling and a biopsy specimen revealed the histological features of typical alveolar rhabdomyosarcoma. The primary site of the neoplasm remained undetermined during the course. At autopsy, it was disclosed that the neoplasm originated from the left thigh and showed generalized metastasis. The second patient was a 38-year-old man, who was admitted in 1986 because of a nasal polyp obstructing the nasal cavity, and persistent nasal bleeding. Peripheral blood samples showed leukoerythroblastosis and thrombocytopenia, and large primitive cells were found in bone marrow aspirates, so that hematological malignancy was initially diagnosed. A biopsy specimen of the nasal polyp showed proliferation of large round cells and electron microscopy demonstrated the ultrastructural features of rhabdomyosarcoma.

Acute Disease↗
PubMed1987

Primary gastric non-Hodgkin's lymphomas in Japan.

A pathological study was carried out on 124 cases of primary gastric non-Hodgkin's lymphoma (NHL) in Japan. Macroscopically the cases were divided into three groups; flat, polypoid, and ulcerative types. Early lymphomas were distinguished from advanced by the depth of infiltration. Histologically the commonest type was ML, immunoblastic (ML, ibl.). Most were high grade malignancy, in terms of morphology. Lymph node involvement was found in 44 cases. Correlation between macroscopical appearance, histological diagnosis, stage and accompanying reactive lymphoid hyperplasia (RLH) was studied. Three main prototypes of gastric NHL were noted: The first was macroscopically ulcerative type, histologically high grade malignancy and lacked RLH; the second was mostly flat, ML, lymphoplasmacytic/lymphoplasmacytoid (ML, l-p.) or ML, ibl., associated with RLH, and arose from neoplastic proliferation of the interfollicular lymphoid cell in RLH (termed gastric NHL of interfollicular type); the third was mostly flat, ML, centroblastic (ML, cbl.) or lymphoblastic (ML, lbl.), associated with RLH, and originated from neoplastic proliferation of the follicular center cell in RLH (gastric NHL of follicular type).

Adult↗
PubMed1987

Postinflammatory mitral and aortic valve prolapse: a clinical and pathological study.

In this study we reevaluated whether the sole cause of mitral valve prolapse (MVP) and aortic valve prolapse (AVP) is myxomatous degeneration. Forty-two surgical cases of prolapsed valves with mitral and/or aortic regurgitation were reviewed (AVP in nine, MVP in 27, and combined AVP and MVP [CVP] in six). On microscopic examination, myxomatous degeneration was observed in 20 patients, including six with AVP, 13 with MVP, and one with CVP. In the other 22 patients, including three with AVP, 14 with MVP, and five with CVP, microscopic examination revealed fibrosis with vascularization and scattered infiltration of inflammatory round cells caused by postinflammatory changes with or without chronic inflammation. We coined the term "postinflammatory valve prolapse" (PIVP) to describe these valves. Both postinflammatory and myxomatous degeneration were observed in seven patients with floppy mitral valves attributable to PIVP. Rupture of chordae tendineae was present in six patients with myxomatous mitral valve and three with PIVP. Seven patients with PIVP had a history of rheumatic fever. The results suggest that valvular prolapse is produced not only by myxomatous degeneration but also by postinflammatory changes, including those caused by rheumatic fever.

Adult↗
PubMed1986

Identification of the tryptophan residue located in the calcium binding site of Trimeresurus flavoviridis phospholipase A2.

When phospholipase A2 from the venom of Trimeresurus flavoviridis (the Habu snake) was oxidized with N-bromosuccinimide at pH 4.0, its activity decreased linearly with increase in the extent of oxidation of tryptophan residues. Oxidation of two of the four tryptophan residues caused an apparent loss of activity. The accessibilities of the tryptophan residues were analyzed with differently oxidized phospholipase A2 preparations and were determined to be in the following order: Trp-3 approximately Trp-30 greater than Trp-68 greater than Trp-108. The magnitude of the difference spectrum with a negative peak at 292 nm which is produced upon the binding of Ca2+ in the vicinity of tryptophan residue(s) decreased in a concave manner with increase in the extent of oxidation of tryptophan residues and was greatly diminished when 2 mol of tryptophan residues were oxidized. The activity and Ca2+-induced difference spectrum are thus related to either Trp-3 or Trp-30 or both. Des-octapeptide(1-8)-phospholipase A2 (L-fragment) is 14% as active as phospholipase A2 and is able to give a Ca2+-induced difference spectrum which is smaller than, but similar to, that of phospholipase A2. Its activity and the magnitude of the Ca2+-induced difference spectrum decreased along similar paths with increase in the amount of tryptophan residues oxidized, but in a manner indicating that two tryptophan residues are apparently responsible for the activity and the Ca2+-induced difference spectrum. The order of accessibility of the tryptophan residues of L-fragment was Trp-30 approximately Trp-108 greater than Trp-68. Trp-108, however, could be excluded from the residues located in the active site by reference to the tertiary structure of homologous Crotalus atrox phospholipase A2. Thus, Trp-30 is located in the Ca2+ binding site and is responsible for the activity of L-fragment. It is thus concluded that in phospholipase A2 Trp-30 is located in the Ca2+ binding site. From the concave decrease of relative magnitude of the Ca2+-induced difference spectrum and the linear decrease of relative activity upon oxidation of phospholipase A2, it may be assumed that both Trp-3 and Trp-30 are required to produce the Ca2+-induced difference spectrum, while only Trp-30 need be intact for activity. Anomalous binding of Ca2+ was observed for oxidized phospholipase A2.

Amino Acids↗
PubMed1986

Amino acid sequence of Trimeresurus flavoviridis phospholipase A2.

The amino acid sequence of phospholipase A2 from the venom of Trimeresurus flavoviridis (the Habu snake) was determined. The enzyme subunit has a molecular weight of 13,764 and consists of a single polypeptide chain of 122 amino acids and seven disulfide bonds. The fragmentation was conducted by digesting the reduced and S-carboxymethylated derivative of the protein with Achromobacter protease I, chymotrypsin, and trypsin, respectively. Achromobacter protease I peptides were used for alignment and to establish overlaps over chymotryptic and tryptic peptides. The automated Edman degradation of the S-carboxymethylated protein, which was extended to the N-terminal 30 amino acid residues, supplemented the deletions found with the enzymatic peptides alone. T. flavoviridis phospholipase A2 was found to be highly (65-67%) homologous in sequence to the enzymes from T. okinavensis, Crotalus adamanteus, and Crotalus atrox (viperid family) and less (35-44%) homologous to those from elapid snakes and mammalian pancreas. The T. flavoviridis enzyme appears to be similar in secondary structure composition to the C. atrox enzyme.

Amino Acid Sequence↗
PubMed1986

A case report of mixed mesodermal tumor of the uterine cervix (mixed, heterologous and homologous sarcoma of the uterine cervix).

A case of mixed sarcoma of the uterine cervix in a 17-year-old girl is reported. The tumor showed polypoid features resembling sarcoma botryoides, and was histologically composed of chondrosarcoma as a heterologous element and stromal sarcoma as a homologous one. Leiomyosarcoma was also found in the tumor, but striated rhabdomyoblasts were not present. No epithelial component was detected. After a total hysterectomy, the patient was given chemotherapy and is in good condition.

Adolescent↗
PubMed1986

Expression of IgD on B cell malignancy. An immunopathological study of 50 cases.

Expression of IgD was studied immunopathologically on 50 cases of B cell lymphomas (B MLs), together with various B cell markers including IgM, kappa and lambda chains, B1, B2, (OK)B2, (OB)B7, (OK)T10, NUB1, Leu 1, Leu 14, and PCA. IgD was demonstrated on 19 cases heavily and on 8 weakly. It associated well with expression of two antigens, B2 (C3d receptor molecule) and Leu1 (pan-T antigen), besides IgM, while, B2 was closely related in expression on B MLs to (OK)B2, (OK)B7, and NUB1. lambda chain was dominant on IgD heavily-stained cases. Histopathologically, IgD positive MLs were distributed in various types. All of diffuse intermediate type were shown to be IgD positive (4/4, 3 heavily). As cases of this type were shown to express most of other B cell antigens present on non-tumorous primary follicle B cells or mantle zone B cells, this type of MLs is speculated to be a neoplastic counterpart of such non-tumorous B cells. Eight out of 18 cases of diffuse large cell type were IgD heavily positive, suggesting some unusual mechanisms in IgD expression on these neoplastic large cells, as non-tumorous B cells lose most of their surface IgD soon after blastoid transformation. Other types of MLs were discussed with special emphasis on expression of IgD.

B-Lymphocytes↗