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61.
The inducibility of sister chromatid exchanges (SCEs) by benzo(a)pyrene (BP) was studied in cultured peripheral blood lymphocytes of 15 untreated lung cancer patients and 25 healthy persons including 11 high- and 14 low-cancer-risk individuals tentatively classified by the familial history of lung cancer and other neoplasms. The baseline SCE frequency in cultured lymphocytes was significantly high in lung cancer patients, as compared with all healthy persons or low-cancer-risk individuals. Following exposure to BP, the lymphocytes of lung-cancer patients and high-cancer-risk individuals exhibited significantly greater SCE yields than those of persons at low risk, although no significant difference was observed in the lymphocyte SCE yields when the levels of lung cancer patients were compared with those of all healthy persons. A comparison of the net SCE increase (delta SCE) in BP-exposed lymphocytes among the study groups, however, revealed a significant difference in delta SCE values only between high- and low-cancer-risk individuals. The present findings on both the observed SCE yields and delta SCE values suggest that lymphocytes of high-risk individuals may be more susceptible to BP-induced DNA damage than those of persons at low risk, and that such a chromosomal hypersensitivity to genotoxins may be associated with a high risk of neoplasms.  相似文献   
62.
To assess the pathophysiological role of atrial natriuretic factors in the regulation of blood pressure, we studied the effect of chronic infusion of a synthetic atrial natriuretic factor of 25 amino-acid residues on blood pressure and sodium-water excretion. Experimental subjects were rats with hypertension made by chronic infusion of vasopressin on regular intakes of sodium or on sodium loading with 1% NaCl as drinking water. When a subdepressor dose (150 micrograms/kg/day) of synthetic atrial natriuretic factor was delivered via an osmotic minipump into the jugular vein simultaneously with 7.2 U/kg/day of vasopressin infused intraperitoneally by another osmotic minipump, the expected elevation of systolic blood pressure was completely inhibited. This was not accompanied by any changes in urine volume and urinary sodium excretion. The antihypertensive effect was sustained throughout the experimental period lasting 3 days in rats on regular sodium intake (p less than 0.01) or on sodium loading with 1% NaCl as drinking water (p less than 0.01). These results indicate that a subdepressor dose of synthetic atrial natriuretic factor can modulate the vasopressor effect of vasopressin. Therefore it is suggested that an atrial natriuretic factor may be involved in the regulation of blood pressure via its antagonizing effect to vasopressin.  相似文献   
63.
M Abe  N Ono  K Tominaga  H Hojo  M Seto  S Fukuhara  H Wakasa 《Cancer》1992,70(4):821-829
Immunohistochemical and molecular genetic (bcl-2 gene) studies were performed on specimens from 24 patients with follicular small cleaved cell lymphoma (FSCCL), 24 patients with diffuse small cleaved cell lymphoma (DSCCL) and 4 patients with mantle zone lymphoma (MZL) to determine the cellular origin of the disease and whether or not DSCCL represents the diffuse counterpart of FSCCL. Two patients with FSCCL, 22 patients with DSCCL, and all of the patients with MZL had a phenotype of mantle zone (MZ) B-lymphocytes (SIgD+, Leu-1+, Leu-8+, positive alkaline phosphatase [ALPase+], and negative common acute lymphoblastic leukemia antigen [CALLA-]), and all the tested patients (2 patients with FSCCL, 13 patients with DSCCL, and 4 patients with MZL) had germlines of bcl-2 gene. Fourteen patients with FSCCL and 1 patient with DSCCL had a phenotype of follicular center cells (FCC) (CALLA+, SIgD-, Leu-1-, Leu-8- and negative ALPase), and 11 patients with FSCCL had bcl-2 gene rearrangements. These results indicate that FSCCL are almost always derived from FCC, whereas some FSCCL, most DSCCL, and all MZL are derived from MZ B-lymphocytes, and these lymphomas should be included in the same category as MZ B-lymphocyte-derived lymphomas. Histologically diagnosed DSCCL often may represent a diffuse counterpart of MZ B-lymphocyte-derived lymphoma. MZ B-lymphocyte-derived lymphomas histologically show a follicular (nodular), a follicular MZ, or a diffuse growth pattern and clinically show a high incidence of peripheral blood (PB) involvement or bone marrow (BM) involvement.  相似文献   
64.
It is shown that a repetitive pulse sequence consisting of two 90° pulses and gradients in a 1:2 ratio around the second 90° pulse generates interscan shifted stimulated echoes (SSTEs) and intrascan multiple spin echoes (MSEs). Separation of these two types of signals is accomplished using specific gradient crusher schemes. The intensity of the SSTEs is an order of magnitude larger than that of the MSEs and determines the signal contrast if both effects are selected simultaneously. The SSTE sequence generates improved contrast between gray and white matter, even at high field, which is explained in terms of increased inverse T1-weighting for the interscan echo. The MSE image has low signal to noise and no detectable contrast. The effect of interscan diffusion weighting is also discussed.  相似文献   
65.
We reported a new monoclonal antibody, designated FUB-1, reacting with normal and neoplastic large lymphoid cells. FUB-1 was produced using a Burkitt's lymphoma cell line (HBL-5) as an immunogen. Its immunoglobulin subtype was IgM. The determinant was not on the surface but in the cytoplasm. Western blotting analysis revealed that the molecular weight of the antigen was 52,000 dalton. In the normal lymphoid tissue, FUB-1 reacted with large lymphoid cells, but not with small or medium-sized lymphoid cells or plasma cells. In addition, the FUB-1 antigen was not found in resting cells in the peripheral blood (PB), but it was induced on mononuclear cells of PB by addition of PWM or PMA. In the B-cell lymphomas tested, FUB-1 reacted with small cleaved cell lymphomas (3/12), large cell lymphomas (7/10), Burkitt's lymphomas (4/4) and immunoblastic lymphomas (2/2), but not with small cell lymphomas (0/3) or intermediate lymphocytic lymphomas (0/8). These findings indicate that the FUB-1 antigen appears to be expressed on normal lymphoid cells during blastoid transformation and on neoplastic large lymphoid cells. FUB-1 also reacted with normal glandular epithelium and various adenocarcinomas. FUB-1 may be useful to investigate the mechanism of in vitro blastoid transformation or activation of lymphoid cells.  相似文献   
66.
Crystal-matrix interrelations in brushite and uric acid calculi   总被引:1,自引:0,他引:1  
Brushite and uric acid calculi were studied by means of scanning electron microscopy with the partial dissolution method and transmission electron microscopy. Brushite calculi consist of radially oriented columnar crystals which have sheet-like substructure. The organic matrix is identified chiefly at the outside of the crystals but partly included between the substructure. The concentric matrix bands are often dislocated between the neighbouring crystals. Uric acid calculi also consist of radially oriented columnar crystals, and a fine meshwork of the organic matrix is incorporated within the crystals. The concentric matrix layers of different density are angled according to the crystal lattice. These findings indicate that the organic matrix arose from a mucinous surface coat, at least in the radially striated calculi. The crystals continued to grow in this gel-state milieu, either thrusting the matrix aside or incorporating it within the crystals.  相似文献   
67.
While nonspecific airway hyperresponsiveness (AHR) is a central feature of allergic bronchial asthma, the mechanism underlying the development of AHR is not clearly understood. We have previously demonstrated in vitro hyperresponsiveness of bronchial smooth muscle to acetylcholine (ACh) in rats that were actively sensitized and repeatedly challenged with aerosolized antigen. It has also been demonstrated that the ACh-induced, RhoA-mediated Ca(2+) sensitization is markedly augmented concomitantly with an increased expression and activation of RhoA protein in the bronchial smooth muscle of the antigen-treated rats. In the present study, we have investigated whether TNF-alpha, a proinflammatory cytokine which is involved in bronchial asthma, causes upregulation of RhoA mRNA and protein in the rat bronchus. Treatment of rat bronchial smooth muscle preparations with TNF-alpha (300 ng/ml for 24 hr) significantly shifted the concentration-response curve to ACh upwards, but did not alter the response to high K(+), when compared to that of control tissues. Levels of RhoA mRNA and protein in the TNF-alpha-treated bronchus were significantly greater than those in the control group. In conclusion, it is suggested that the augmentation of the ACh-induced contractile response evoked by TNF-alpha might be mediated by an upregulation of RhoA in rat bronchial smooth muscle.  相似文献   
68.
69.
To compare levels of y-seminoprotein (gM-Sm) assayed by original and revised assay systems, blood was obtained every 4 h over a 32-h period from 8 untreated prostate cancer patients. Serum levels of prostate specific antigen (PSA) were also examined. In 6 patients, the coefficient of variation (CV) of the serum levels assayed by the revised assay was significantly different from that of the intra-assay samples. In contrast, the CV of the gM-Sm serum levels assayed by the original assay differed significantly from that of the intra-assay samples in only 2 patients. The fluctuations in gM-Sm assayed by the revised assay were, at least in part, similar to those of the PSA serum levels in all patients. The mean CV of the gM-Sm serum levels assayed by the revised assay was significantly larger than that for levels measured by the original assay. After treatment, the rate of decrease in gM-Sm serum levels determined by the original assay differed from that in the serum levels of PSA and prostatic acid phosphatase. These results indicate that the original assay for gM-Sm do not detect diurnal differences in serum gM-Sm levels, even at levels below 20 ng/ml. These observations indicate that the analysis of data obtained using the original gM-Sm kit should be interpreted with caution.  相似文献   
70.
The actions and interactions of purified recombinant human (rh) interleukin 4 (IL-4) and granulocyte colony-stimulating factor (G-CSF) on the clonogenicity of human leukemic cell line U937 were studied in vitro. Parameters analyzed were the suppression of stem cell generation using sequential clonal cultures, alterations of surface antigen expression, and morphological changes. IL-4 alone (10 U/ml) and G-CSF alone (1000 U/ml) only slightly reduced colony numbers (80% +/- 7% and 87% +/- 7% of control colonies, respectively). However, IL-4 interacted synergistically with G-CSF to further reduce the colony number (46% +/- 8% of control colonies) and suppress the self-renewal ability (clonogenicity) of U937 cells. This synergistic effect was not eliminated by cultures containing neutralizing concentrations of anti-granulocyte-macrophage colony-stimulating factor (anti-GM-CSF), anti-interleukin 6 (anti-IL-6), anti-interferon-alpha (anti-IFN-alpha), anti-IFN-gamma, anti-transforming growth factor-beta (anti-TGF-beta) serum, and anti-tumor necrosis factor-alpha (anti-TNF-alpha) serum. The coexistence of IL-4 and G-CSF was required for at least 48 h to reveal the synergistic action as assessed by preincubation and delayed addition experiments. Combinations of IL-4 and G-CSF showed a significant increase in CD11b expression on U937 cells. This action was not observed with HL60, K562, ML-1, or KG-1 leukemic cell lines, and IL-4 did not show any synergistic suppression of clonogenicity of U937 leukemic cells in combination with other cytokines tested in this study. These results suggest that IL-4 in combination with G-CSF may have some capacity to synergistically suppress human leukemic cells of specific types with loss of clonogenicity.  相似文献   
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