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N Sera

Publications and source records attributed to N Sera.

At least 19 recordsLinked to original sources
PubMed2006

Murine strain differences in 8-hydroxy-deoxyguanosine formation in hepatic DNA induced by oxidized lard and dietary oils.

Difference of 8-hydroxy-deoxyguanosine (8-OH-dG) formation in liver DNA in C3H/HeN and in C57BL/6 mice--fed oxidized lard and dietary oils (soybean and sardine)--was investigated. The blank levels of 8-OH-dG were higher in C3H/HeN mice (highly sensitive to liver tumorigenesis) than in C57BL/6 mice (resistant strain). The level of 8-OH-dG increased much more in C3H/HeN mice than in the C57BL/6 mice fed by oxidized lard and dietary oil treatment. Feeding oxidized lard and dietary oils increased 8-oxo-guanine DNA glycosylase I (OGG1) and mRNA 8-oxo-dGTPase in C57BL/6 mice. On the other hand, no appreciable change of mRNA in the C3H/HeN mice was observed. The formation differences of 8-OH-dG from the two murine strains fed with oxidized lard and dietary oils may be associated with the different mRNA levels in the DNA repair enzymes because the mRNA levels in the DNA repair enzymes were much lower in C3H/HeN mice than in C57BL/6 mice.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2002

The mutagenicity of amino-derivatives of diphenyl ether herbicides in new Salmonella typhimurium YG tester strains.

In this study, we examined the mutagenicity of four diphenyl ether herbicides and their amino derivatives in Salmonella typhimurium TA tester strains and YG tester strains. YG tester strains have been newly developed for sensitive detection of specific chemicals. S. typhimurium YG 1021, YG 1024, YG 1026 and YG 1029 strains are sensitive to mutagenic nitoroarenes and hydroxyamines. S. typhimurium YG 3003 is a strain that is sensitive to some oxidative mutagens. And S. typhimurium YG 7108 is useful for detection of mutagenic alkylating agents. As a result, each amino derivative of diphenyl ether herbicides is more mutagenic than its parent herbicide in S. typhimurium TA and YG tester strains with metabolic activation by S9 mixture. Moreover, S. typhimurium YG tester strains are more useful for highly sensitive detection of mutagens than S. typhimurium TA tester strains. We also examined the production of amino derivatives in a water environment from parent herbicides. It was clear that diphenyl ether herbicides rapidly transform to amino derivatives in a water environment.

Amines↗
PubMed2001

Fas/FasL mediated apoptosis of thyrocytes in Graves' disease.

We examined in the present study the possible involvement of Fas and its ligand (FasL) in the process of Graves' disease. Immunohistochemical analysis showed that few normal thyrocytes expressed Fas but many thyrocytes in Graves' disease expressed this molecule. The percentage of FasL-positive thyrocytes in Graves' thyroids was, however, less than in normal thyroids. Several apoptotic thyrocytes and infiltrating mononuclear cells (MNCs) were detected scattered throughout Graves' thyroid tissues and abundant proliferating cell nuclear antigen (PCNA)-positive thyrocytes were present. Apoptotic cells, as well as PCNA-positive cells, were scarcely detectable in normal thyroid glands, however. In vitro treatment of thyrocytes by IL-1beta a cytokine found to be expressed in Graves' thyroid glands, increased Fas but reduced FasL expression. IL-1beta-stimulated thyrocytes became sensitive to apoptosis by anti-Fas IgM monoclonal antibody (mAb). Activated T cells, which strongly expressed FasL, showed cytotoxic activity toward IL-1beta-stimulated thyrocytes but not toward unstimulated thyrocytes. This cytotoxic activity involved the Fas/FasL pathway. Importantly, unstimulated thyrocytes could kill activated, but not resting, T cells. IL-1beta-stimulated thyrocytes, with down-regulated FasL expression, could not efficiently kill activated T cells. The cytotoxic activity of unstimulated thyrocytes toward activated T cells was inhibited by anti-FasL mAb. Interestingly, unstimulated thyrocytes induced apoptosis in IL-1beta-stimulated thyrocytes but not in unstimulated thyrocytes. These interactions were also blocked by anti-FasL mAb. Our results suggest that the apoptotic cell death of both thyrocytes and infiltrating MNCs found in Graves' thyroid glands is regulated by IL-1beta through Fas/FasL interactions.

Apoptosis↗
PubMed2001

Elevation of serum pro-gastrin-releasing peptide in patients with medullary thyroid carcinoma and small cell lung carcinoma.

Medullary thyroid carcinoma (MTC) arises from parafollicular or C cells of the thyroid gland and produces a variety of peptides such as calcitonin (CT) and gastrin-releasing peptide (GRP). Here we measured serum levels of pro-gastrin-releasing peptide (Pro-GRP), a more stable precursor of GRP, in 15 patients with MTC (4 males, 11 females) who did not show any clinical or radiologic signs of small cell lung cancer. Serum Pro-GRP levels were elevated in 80% (12/15) patients. Significant correlation was observed between serum Pro-GRP and CT (r = 0.52) and carcinoembryonic antigen (CEA) (r = 0.56). Serum Pro-GRP levels also correlated with tumor size (r = 0.70). Serum Pro-GRP levels also decreased below the cut-off range in one patient after surgical resection. Our data suggest that Pro-GRP, which is considered to be a specific marker for small cell lung carcinoma, seems to be also helpful and additional marker for the diagnosis and monitoring the response to therapy in patients with MTC in addition to calcitonin as the main tumor marker.

Adult↗
PubMed2001

Micronucleus induction and chromosomal aberration of 1- and 3-nitroazabenzo[a]pyrene and their N-oxides.

Nitro-azabenzo[a]pyrenes, 1- or 3-nitro-azabenzo[a]pyrene and their N-oxides are nitrated derivatives of azabenzo[a] pyrene (ABP) containing nitrogen in the 6-position of benzo[a]pyrene (B[a]P). The nitro-ABP-N-oxides (ABPOs) were formed by reaction of ABP with excess HNO(3). These derivatives were noteworthy as potent mutagens for Salmonella strains, and were present in fine particles of diesel particulates. In this study, micronucleus induction in mice and chromosomal aberrations due to means of Chinese hamster lung fibroblast (CHL) cells were investigated to determine genotoxicity in order to define the relationship with the mutagenic potency of these derivatives. The induction of micronucleus polychromatic erythrocytes (MNPCEs) was dependent on the dose response of 10-40 mg for 3-N-6-ABP, and of 10-40 mg for 1-N-6-ABP, and in addition, 1- and 3-N-6-ABPOs markedly induced MNPCEs in a dose range of 10-400 mg and from 1 to 80 mg, respectively, when the compound was intraperitoneally administrated in two mice at each dose. The results show that of the four compounds, 3-N-6-ABPO demonstrated a marked increase in MNPCES: On the other hand, chromosomal aberrations of the four compounds were investigated by the duplicate tests using CHLS: The results after a 48 h treatment induced aberrations of the chromatid type, chromatid breaks and exchanges for 1- and 3-N-6-ABP, and mainly chromatid exchanges for 1- and 3-N-6-ABPO. The frequency of chromosomal aberrations associated with nitro substitution on the ABPO structure. Chromosomal aberrations of nitro derivatives of ABPO substituted at the 3-position on the structure were more potent than those at the 1-postion. N-oxide derivatives have been found to be reduced to anion radicals much more easily than azaB[a]P and its nitro derivatives. This suggests that the electrochemical reduction of the chemicals plays an important role in the metabolic activation of nitrated B[a]P derivatives.

Animals↗
PubMed2001

Isolation and characterization of Desulfitobacterium sp. strain Y51 capable of efficient dehalogenation of tetrachloroethene and polychloroethanes.

A strict anaerobic bacterium, strain Y51, was isolated from soil contaminated with tetrachloroethene (PCE). Strain Y51 is capable of very efficiently dehalogenating PCE via trichloroethene (TCE) to cis-1,2-dichloroethene (cis-1,2-DCE) at concentrations as high as 960 microM and as low as 0.6 microM. Strain Y51 was gram-negative, motile with some lateral flagella, and curved rod-shaped. On the basis of the 16S rDNA sequence, the organism was identified to be a species within the genus Desulfitobacterium. Strain Y51 also had dehalogenation activities toward polychloroethanes such as hexa-, penta-, and tetrachloroethanes, from which dichloroethenes were produced as the final products. The cell extracts mediated the dehalogenation of PCE with reduced methyl viologen as an electron carrier at the specific rate of 5.0 nmol min(-1) mg cell protein(-1) (pH 7.2, 37 degrees C). Dehalogenation was highly susceptible to air oxidation, and to potential alternative electron acceptors such as nitrite or sulfite.

Bacillaceae↗
PubMed2001

Pulmonary nocardiosis associated with idiopathic thrombocytopenic purpura.

A 69-year-old woman with idiopathic thrombocytopenic purpura, who was regularly followed and treated with prednisolone and danazol, was admitted to our hospital because of shortness of breath. Chest roentgenogram showed a large amount of left-sided pleural effusion. Gram-positive branching rods, subsequently identified as Nocardia farcinica, were isolated from the fluid. Antibiotic treatment together with pleural drainage with an intercostal catheter resulted in complete remission of pyothorax. Pulmonary nocardiosis is a rare disease, but recognition of the disease in immunocompromised patients and the prompt initiation of appropriate treatments based on isolation of the pathogen can lead to a successful outcome.

Aged↗
PubMed2000

Mutagenic activity of surface soil and quantification of 1,3-, 1,6-, and 1,8-dinitropyrene isomers in soil in Japan.

To clarify the mutagenic potential of nonagricultural surface soil in Japan, 110 soil samples were collected from five geographically different areas between November 1996 and March 1997, and organic extracts of the soil samples were examined by the Ames/Salmonella assay. Most of the soil extracts showed mutagenicity toward both strains TA98 and TA100 in the presence and/or absence of a mammalian metabolic activation system (S9 mix), suggesting that surface soil is largely contaminated with environmental mutagens. Soil samples collected at Hekinan, Kobe, and Osaka were highly mutagenic toward both strains, and their potencies toward TA98 without S9 mix were extremely high, inducing more than 12 000 revertants per gram of soil. On the other hand, soil samples from Muroran showed strong mutagenicity toward TA100 with S9 mix. Furthermore, 1, 3-dinitropyrene (DNP), 1,6-DNP, and 1,8-DNP in soil samples collected at 10 sampling sites in three metropolitan areas were quantified by fluorometric detection of the corresponding diaminopyrene isomers using high-performance liquid chromatography (HPLC). Three DNP isomers were detected in all soil samples, and the amounts of 1,3-, 1,6-, and 1,8-DNP isomers in the soil samples were 12-3270, 14-5587, and 13-6809 pg/g, respectively. The gross amount of three DNP isomers in surface soil collected at Hekinan was more than 10 ng per gram of soil. The highest contribution ratios of DNP isomers to the mutagenicity of soil extracts were observed for the samples collected at Osaka, and the total of the contribution ratios of three DNP isomers was about 50%. These results suggest that surface soil is largely contaminated with mutagenic compounds and that DNP isomers are one class of major mutagenic and carcinogenic compounds contaminating surface soil.

Air Pollutants↗
PubMed2000

CD4+ T cell-mediated cytotoxicity toward thyrocytes: the importance of Fas/Fas ligand interaction inducing apoptosis of thyrocytes and the inhibitory effect of thyroid-stimulating hormone.

The accumulation of activated CD4+ T cells and antigen (Ag)-dependent cellular interactions between thyrocytes and CD4+ T cells have been determined in thyroid gland from patients with Graves' disease. The Fas/Fas ligand (FasL) interaction between antigen-presenting cells and T cells regulates the apoptosis of the former cells triggered by the latter cells. The inhibition of Fas-mediated apoptosis in thyrocytes could be a underlying mechanism of hyperplasia of thyrocytes in patients with Graves' disease. We investigated the potential role of Fas/FasL interaction between thyrocytes and CD4+ T cells in the induction of Fas-mediated apoptosis of the former cells induced by the latter cells. The presence of only a few specific T cells responsive to a putative autoantigen has hampered the investigation of specific T cell activation toward antigen-presenting cells (APCs). Therefore, we used a superantigen, staphylococcal enterotoxin B (SEB), to examine specific T cell activation toward thyrocytes in vitro since it stimulates a large proportion of T cells with particular Vbeta elements. Spontaneous apoptosis of thyrocytes in culture was not found even in the presence of various kinds of cytokines. In contrast, a clear induction of Fas-mediated apoptosis by anti-Fas IgM was determined in interferon-gamma (IFN-gamma)-stimulated thyrocytes. In addition, a significant cytotoxicity of purified CD4+ T cells toward IFN-gamma-stimulated thyrocytes in the presence of SEB was induced, and the addition of anti-HLA-DR and -DQ monoclonal antibodies (mAbs) or blockade of the Fas/FasL interaction reduced this cytotoxicity. FasL expression of CD4+ T cells cocultured with IFN-gamma-stimulated thyrocytes in the presence of SEB was clearly induced. Furthermore, the addition of mAbs against CD54 and CD58 inhibited both cytotoxicity and FasL expression of CD4+ T cells. The cytotoxicity of CD4+ T cells toward IFN-gamma-stimulated, SEB-pulsed thyrocytes was markedly inhibited when we used thyrocytes cultured with IFN-gamma in the presence of thyroid-stimulating hormone (TSH) as target cells. Our results suggest that 1) CD4+ T cells were activated by thyrocytes expressing MHC class II molecules in an SEB-dependent manner and then expressed FasL. 2) These activated FasL+ CD4+ T cells killed thyrocytes by interacting with Fas on thyrocytes and FasL on activated CD4+ T cells. The presence of costimulating molecules such as CD54 and CD58 on thyrocytes was also necessary to generate activated FasL+ CD4+ T cells. 3) Since the actions of thyroid stimulating antibody (TSAb) toward thyrocytes are similar to those of TSH, one goitrogenic activity of TSAb may, in part, be due to the inhibitory effect on Fas-mediated apoptosis of thyrocytes triggered by activated CD4+ T cells.

Apoptosis↗
PubMed2000

Parathyroidectomy for primary hyperparathyroidism induces positive uncoupling and increases bone mineral density in cancellous bones.

OBJECTIVE: Osteopenia is an important feature of primary hyperparathyroidism (PHP). However, little is known about the change of bone mineral density (BMD) in PHP after surgery. The aim was to investigate the mechanisms of increased BMD after parathyroidectomy in patients with PHP. DESIGN: Prospective observational study. PATIENTS: Ten patients with PHP (7 women, 3 men; mean age 53.2+/-9.1 years). All patients underwent parathyroidectomy for excision of parathyroid adenoma. MEASUREMENTS: BMDs of two cancellous bone-rich sites (L2-L4 lumbar spine and ultra-distal end of the radius, RUD) and one cortical bone-rich site (distal third of the radius, R33%) were measured using dual energy X-ray absorptiometry, before, and 3, 6 and 12 months after surgery. Serum intact PTH, intact osteocalcin, bone type alkaline phosphatase (b-ALP), alkaline phosphatase, calcium, and urinary deoxypyridinoline (Dpd) were measured before, and 1 and 3 days, and 1, 2, 3, 4, 6, 8, 12, and 24 weeks after surgery. RESULTS: Parathyroidectomy resulted in a significant increase in BMDs of L2-L4 and RUD at 3 months postoperatively. Urinary Dpd levels decreased within a few days after surgery, while b-ALP and osteocalcin decreased more slowly throughout the first few months after surgery. The ratio of osteocalcin/Dpd at 1 week after surgery correlated significantly with the percentage change in BMD of L2-L4 at 3 and 6 months after surgery. The ratio of osteocalcin/Dpd at 2 weeks correlated significantly with the percentage change in BMD of L2-L4 at 3, 6 and 12 months after surgery. The preoperative values of osteocalcin, b-ALP, PTH and calcium were positively correlated with the change in BMD of RUD at 3 months and L2-L4 at 12 months, RUD at 6 months, RUD at 3 months and L2-L4 at 12 months, respectively. CONCLUSIONS: In primary hyperparathyroidism patients, the major increase in bone mineral density following parathyroidectomy occurs within 3 months. Parathyroidectomy resulted in a marked increase in bone mineral density of cancellous bones compared to that of cortical bones. The early increase in bone mineral density was due to a preferential activation of bone formation over bone resorption as evidenced by changes in bone metabolic markers. Our results also showed that the preoperative levels of bone metabolic markers may predict the gain in bone mineral density after parathyroidectomy.

Adenoma↗
PubMed2000

Etidronate inhibits human osteoblast apoptosis by inhibition of pro-apoptotic factor(s) produced by activated T cells.

Humoral factors produced by activated T cells are thought to be important in the development of bone loss in patients with rheumatoid arthritis (RA). We investigated the inhibitory effect of etidronate disodium (EHDP) on apoptosis of human osteoblasts induced by supernatants from in vitro activated T cell cultures. Human osteoblastic cell line MG63 cells and human primary osteoblast-like cells were used in the present study as human osteoblasts. T cells were incubated with interleukin-2 and further activated with 1 2-o-tetradecanoyl-phorbol 13-acetate and ionomycin, either in the presence or absence of EHDP. After we carried out the cultivation, we examined the cytotoxicity of cultured T cell supernatants toward MG63 cells and human primary osteoblast-like cells. Supernatants from activated but not resting T cell cultures efficiently induced apoptosis of MG63 cells and primary osteoblast-like cells. Supernatants from activated T cell cultures, incubated with EHDP, exhibited significantly less cytotoxicity than did supernatants incubated in the absence of EHDP. In contrast, the cytotoxicity of activated T cell culture supernatants was not affected by direct treatment of human osteoblasts with EHDP. The concentration of soluble Fas ligand in activated T cell culture supernatants was actually increased by EHDP. However, EHDP did not influence soluble Fas and tumor necrosis factor-alpha concentrations in the supernatant. Furthermore, treatment of human osteoblasts with EHDP did not alter their expression of Bcl-2/Bcl-xL or their sensitivity to anti-Fas immunoglobulin M-induced apoptosis. Our results suggest that EHDP inhibits the production of soluble factor that induces apoptosis of human osteoblasts and thus exhibits a protective action toward human osteoblast apoptosis induced by activated T cell culture supernatants. Although the exact EHDP-regulated molecule that induces apoptosis of human osteoblasts is unknown at present, our study may explain part of the therapeutic action of bisphosphonates in RA complicated by bone loss.

Apoptosis↗
PubMed2000

Thyroid hormones influence serum leptin levels in patients with Graves' disease during suppression of beta-adrenergic receptors.

Leptin is a protein product of the ob gene, mainly produced by adipocytes. Leptin is thought to play an important role in the homeostasis of body weight by suppressing appetite and increasing energy consumption. The aim of this study was to investigate the possible effect of thyroid hormone on the regulation of the leptin system during suppression of beta-adrenergic receptors in Graves' patients. We studied 15 adult female patients with Graves' disease. Thyroid function, serum levels of leptin, and percent body fat (%BF) were examined at four different clinical conditions during therapy (A, untreated; B, beta-adrenergic antagonist only [A, B; hyperthyroid], C, beta-adrenergic antagonist and antithyroid drug; D, antithyroid drug only [C, D; euthyroid]). The use of beta-adrenergic antagonist significantly reduced heart rate in spite of hyperthyroid state, indicating sufficient suppression of beta-adrenergic receptors. During treatment with beta-adrenergic antagonist, leptin percentage of body fat (%BF) ratio significantly decreased in euthyroid state compared to that in hyperthyroid state (from 38.7 +/- 21.3 to 18.1 +/- 19.3, p = 0.003). Moreover, there was a significantly positive correlation between delta leptin/%BF and delta free thyroxine (FT4) (r = 0.51, p = 0.008). Under a euthyroid state induced by antithyroid drug treatment, leptin/%BF did not change in spite of withdrawal of beta-adrenergic antagonist. Our data indicate that thyroid hormones could increase serum leptin level during suppression of beta-adrenergic receptors in Graves' patients. Our data also suggest that the beta-adrenergic action of thyroid hormones might be partly mediated by regulation of leptin.

Adrenergic beta-Antagonists↗
PubMed2000

Treatment with propylthiouracil is associated with appearance of antineutrophil cytoplasmic antibodies in some patients with Graves' disease.

The use of propylthiouracil (PTU) for the treatment of Graves' disease is associated with few adverse effects such as skin eruptions, liver dysfunction, and agranulocytosis. Furthermore, recent studies described the development of antineutrophil cytoplasmic antibody (ANCA)-related glomerulonephritis and vasculitis in patients treated with PTU. Here we investigated whether PTU therapy per se is associated with the appearance of ANCA in patients with Graves' disease. We analyzed 119 serum samples from 117 patients with Graves' disease treated with either PTU (n = 56), or methimazole (MMI) (n = 21), as well as untreated patients (n = 42). Myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA were tested by enzyme-linked immunosorbent assay (ELISA) kits. MPO-ANCA was negative in all patients treated with MMI therapy and untreated patients. However, MPO-ANCA was detected in 21 (37.5%) of 56 patients treated with PTU therapy. Furthermore, two patients who were negative for MPO-ANCA became positive after PTU therapy. The proportion of patients positive for MPO-ANCA increased with the prolongation of PTU therapy, but did not correlate with age, gender, and positive antithyroperoxidase (TPO) antibody. Among 21 MPO-ANCA positive patients, 12 had no symptoms, but 9 patients complained of myalgia, arthralgia, or common cold like symptoms after the appearance of MPO-ANCA. Three patients developed agranulocytosis or granulocytopenia, but none showed abnormal urinary findings. Our results suggest that PTU per se is associated with the production of MPO-ANCA in patients with Graves' disease.

Adult↗
PubMed2000

Anaplastic changes associated with p53 gene mutation in differentiated thyroid carcinoma after insufficient radioactive iodine (131I) therapy.

Thirty-two patients with differentiated thyroid carcinomas with distant metastasis were examined using a radioactive iodine (131I) tracer dose prior to 131I therapy and followed up for 10 years or until death (whichever occurred first). Nineteen patients who received 131I therapy had an accumulation of 131I in the metastases (group I) and 15 of those patients were alive more than 10 years after the first 131I treatment. In contrast, all 13 patients in whom the metastases did not show accumulation of 131I died within 10 years. Of the latter group, eight patients had received 131I therapy (group II), four of whom died with anaplastic changes within 5 years of treatment. p53 gene mutation was identified by immunohistochemistry in primary thyroid carcinoma tissue from patients with anaplastic changes that were evident during total thyroidectomy. Five patients did not receive 131I therapy (group III), of whom one, who also had a p53 gene mutation in the original tumor, died with anaplastic change 10 years after thyroidectomy. Seven patients in group I had p53 gene mutations in their thyroid carcinoma tissues, but none showed anaplastic changes. Our results suggest that 131I therapy may be useful for patients with distant metastases, with or without p53 gene mutations, which show accumulation of 131I from tracer and therapeutic doses. In contrast, 131I therapy is apparently not effective in patients who do not show sufficient accumulation of 131I, but rather, may cause early anaplastic changes with a p53 gene mutation.

Adult↗
PubMed1999

8-Hydroxyguanosine formed in human lung tissues and the association with diesel exhaust particles.

Diesel exhaust particles consist of various organic chemicals, heavy metals, and carbon particles. Knowledge of the fate of organic chemicals and carbon particles in the lungs is important to determine the mechanisms responsible for lung tumors. In the present study, diesel particle extracts were found to show mutagenicity for YG3003, a sensitive strain to some oxidative mutagens, as well as other mutant strains, and those of lung tissues obtained from lung cancer patients exhibited potent mutagenicity. Formation of 8-hydroxyguanosine (8-OHdG) as a biomarker of oxidative damage was analyzed with in vitro and in vivo assay systems. The 8-OHdG was detected in all 22 cases of lung tissues with carcinomas tested and their levels increased with the increasing age of the patients, suggesting a correlation between age and the presence of carbon particles in lung tissues. Therefore, the formation of 8-OHdG due to diesel exhaust particles was investigated via intratracheal injections into mice. 8-OHdG formation was elevated when carboneceous particles, after removal of organic chemicals with various solvents, were administered to mice, but it was not elevated when polyaromatic compounds such as benzo[a]pyrene, 1,8-dinitropyrene, and 1-nitropyrene were used in the same procedure in mice. The carboneceous particles were formed from a giant particle that was aggregated by micro-particles with diameters of 1.47 +/- 1.34 to 1.05 +/- 0.83 microm. These results suggest that carboneceous particles, but not mutagens and carcinogens, promote the formation of 8-OHdG, and that as a mechanism, alveolar macrophages may be involved in oxidative damage. The oxidative damage may be due to the fact that the mutation is involved with the generation of a hydroxyl radical during phagocytosis, and the hydroxyl radical leads to hydroxylation at the C-8 position of the deoxyguanosine residue in the DNA.

Adolescent↗
PubMed1998

Analysis of environmental carcinogens associated with the incidence of lung cancer.

It is presumed that carcinogens present in human lungs contribute to the incidence of lung cancer. Most of the carcinogens are inhaled in lung alveoli with particulate matter through the respiratory tract. On the basis of chemical analysis of 256 lung specimens with carcinomas resected in the period 1991 1996, the concentration of 1-nitropyrene (1-NP) was 19.7+/-10.5 pg/g of dry weight, and that of the dinitropyrenes (DNP) was 3.50+/-0.14-6.26+/-1.76. In addition, 2-nitrofluoranthene (NF) and 3-NF were detected at a higher level of 38.6+/-17.2 and 39.1+/-14.2, respectively, pg/g of dry weight. Concentrations of benzo[a]pyrene, benzo[e]pyrene, benzo[k]fluoranthene and benzo[ghi]perylene in 37 specimens collected in the period 1991 1996, were in the range of 138+/-82-399+/-220 pg/g of dry weight. No difference was found in the concentration of chemicals deposited in lung specimens from patients with lung cancer and tuberculosis as a control. By following the prognosis of 112 patients with carcinomas, we found that the deposition of 1-NP, 1,3-DNP, and 3-NF in lung tissues influenced their 5-year-survival after determination of chemicals. Lung specimens were divided into two groups of higher and lower chemical concentrations at the levels of 18 pg/g for 1-NP, 15 for 1,3-DNP, and 35 for 3-NF, and the findings were statistically analyzed by adjusting for age, gender, smoking status and cell type. The 5-year-survival of patients was markedly lower in the higher concentration group than the lower group.

Adult↗