Accumulation of polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like PCBs in black-tailed gulls and eggs.
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Animals↗
Biomedical subjects
M Matsuda
Publications and source records attributed to M Matsuda.
Accumulation profiles of persistent organochlorines in waterbirds from an estuary in Korea.
Persistent organochlorine pollutants (POPs), such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and organochlorine (OC) pesticides such as DDTs (dichlorodiphenyltrichloroethane), HCHs (hexachlorocyclohexane isomers), CHLs (chlordane compounds) and HCB (hexachlorobenzene), were measured in subcutaneous fat of resident and migratory birds collected from the Nakdong River estuary (NRE) in Korea. Black-tailed gull, a resident bird from the NRE, contained greater concentrations of PCDD/Fs and PCBs than the migratory birds collected in the estuary. For example, mean concentrations of PCDD/Fs in black-tailed gull (395.5 pg/g fat weight) were higher than those in migratory birds, such as greenshank (198.3 pg/g fat weight), common gull (90.9 pg/g fat weight) black-headed gull (84.2 pg/g fat weight), and common tern (47.1 pg/g fat weight). However, concentrations of DDTs and/or HCHs were great in some migratory species, such as little tern (mean DDT 6,200 ng/g fat weight) and black-necked grebe (HCHs 475 ng/g fat weight). This suggested that contamination of PCDD/Fs and PCBs in resident gulls are due to intake of locally contaminated fish near the NRE. Elevated OC pesticide levels in migratory birds indicated that these birds have been exposed to DDTs and HCHs during their migration in Southeast Asian countries where chlorinated pesticides are still used. 2,3,7,8-Tetrachloro dibenzo-p-dioxin equivalents (TEQs) were calculated using the toxic equivalency factors (TEFs) reported by World Health Organization in 1998. Four of the 2,3,7,8-substituted congeners of PCDD/Fs contributed over 90% of the TEQs.
Adipose Tissue↗
Genetic analysis of cataract in Ihara epileptic rat.
We analyzed the mode of inheritance of cataract in the Ihara epileptic rat (IER) by crossing experiments, and mapped cataract-related genes by linkage analysis. Cataract did not develop in the F1 animals, but it developed in both male and female animals of backcross and F2. The occurrence rate of cataract was 48.5% in the backcross progeny and 19.4% in the F2 progeny. Thus, the character was considered to be inherited by the autosomal recessive mode. We found two groups that differed according to the time of onset among the backcross and F2 progeny: an early-onset group (EOG), in which cataracts developed by about 4 months after birth, and a late-onset group (LOG), in which cataracts developed 8 months or more after birth. Linkage analysis indicated the presence of one cataract gene each on Chromosome (Chr) 8 and Chr 15, and the cataract was demonstrated to be governed by more than one gene. The gene on Chr 8 was named Catil, and that on Chr 15. Cati2. Catil was involved in the occurrence of cataract, and the conditions required for cataract to develop were Cati1i/Cati1i or Cati1i/Cati1w. However, in the cataract rats with Cati1i/ Cati1w, the allele of Cati2 was always Cati2i/Cati2i. Cati2 was involved in the timing of onset of the cataract, and the precondition for early onset was Cati2i/Cati2i.
Age of Onset↗
Change in post-exercise vagal reactivation with exercise training and detraining in young men.
We studied the effects of aerobic exercise training and detraining in humans on post-exercise vagal reactivation. Ten healthy untrained men trained for 8 weeks using a cycle ergometer [70% of initial maximal oxygen uptake (VO2max) for 1 h, 3-4 days.week-1] and then did not exercise for the next 4 weeks. Post-exercise vagal reactivation was evaluated as the time constant of the beat-by-beat decrease in heart rate during the 30 s (t30) immediately following 4 min exercise at 80% of ventilatory threshold (VT). The VO2max and the oxygen uptake at VT had significantly increased after the 8 weeks training programme (P < 0.0001, P < 0.001, respectively). The t30 had shortened after training, and values after 4 weeks and 8 weeks of training were significantly shorter than the initial t30 (P < 0.05, P < 0.01, respectively). The change in the t30 after 8 weeks of training closely and inversely correlated with the initial t30 (r = -0.965, P < 0.0001). The reduced t30 was prolonged significantly after 2 weeks of detraining, and had returned almost to the baseline level after a further 2 weeks of detraining. These results suggest that aerobic exercise training of moderate intensity accelerates post-exercise vagal reactivation, but that the accelerated function regresses within a few weeks of detraining.
Adult↗
Multicentric occurrence of hepatocellular carcinoma: diagnosis and clinical significance.
To evaluate current knowledge on the multicentric occurrence (MO) of hepatocellular carcinoma (HCC) and its clinical significance was the purpose of this review. The criteria for MO of HCC are defined as follows: (1) the recurrent tumor consists of well differentiated HCC occurring in a different hepatic segment from moderately or poorly differentiated preexisting HCC, (2) both the primary and recurrent tumors are well differentiated HCC, (3) the recurrent tumors contain regions of dysplastic nodules in peripheral areas and, (4) multiple HCCs, indicating the "nodule-in-nodule" form, in which nodules consisting of moderately or poorly differentiated HCC cells are contained in a nodule of well differentiated HCC cells. However, these criteria assume rare or no metastasis of well differentiated HCC, and are also not applicable to cases in which some HCCs of multicentric origin are rapidly dedifferentiated, presenting morphologic features of moderately or poorly differentiated tumors. Diagnostic methods, besides histopathologic methods, for determining multicentric origin in multiple HCCs in the liver, or recurrent tumor(s) of HCC, include clonal analysis of the integration pattern of hepatitis B virus (HBV) DNA in HBV carrier patients, and analysis of the p53 mutation patterns or loss of heterozygosity of chromosomal DNA. The prognosis of patients with MO of HCC after curative resection is significantly better than that of patients with intrahepatic HCC metastasis. Moreover, the Liver Cancer Study Group of Japan has reported that patients with hepatic resection for small-sized HCCs showed higher survival rates than a nonsurgical treatment group. Consequently, HCC with MO, whether this is synchronous or metachronous, should be surgically removed as the treatment of first choice.
Carcinoma, Hepatocellular↗
Surgical treatment of recurrent hepatocellular carcinoma based on the mode of recurrence: repeat hepatic resection or ablation are good choices for patients with recurrent multicentric cancer.
Hepatocellular carcinomas (HCC) often recur after curvative resection. Recurrence in the remnant liver originates from intrahepatic metastasis (IM) from the primary resected tumor, and/or from multicentric (MC) occurrence. In order to achieve better survival after intrahepatic recurrence in HCC patients, we have surgically treated patients according to the recurrence pattern. In this study, we investigated the advantage of repeat surgery for MC recurrent HCC. The subjects were 176 patients who had undergone primary macroscopically complete tumor removal for HCC at our department from 1984 to 1999. Differential diagnosis of IM and MC recurrence was done by pathological analysis. Twenty-nine of the 149 patients with recurrence (19.5%) underwent a total of 31 second and third operations. Of the 29 patients, 18 had MC (14 received repeat hepatectomy and 4, microwave tissue coagulation [MTC]), 7 had IM (4 had repeat hepatectomy and 3, MTC), and, in 4 patients, pathological investigation failed to determine the mode of recurrence. The 1-, 3-, and 5-year survival rates for MC patients after the repeat operations were 100%, 69.7%, and 58.1%, respectively, and the 1-, 3-, and 5-year survival rates for the IM patients were 57.1%, 14.3%, and 14.3%, respectively. Survival after the repeat operation was significantly better in the MC group than in the IM group (P = 0.0016). Moreover, there was no significant difference between survival in the MC group after a repeat operation and survival in control patients after an initial hepatectomy (P = 0.9282). These results indicated that patients with resectable or ablative recurrent MC HCC have almost the same survival benefit after repeat operations as patients who undergo initial curative resection of HCC.
Aged↗
Immunohistochemical study of p53, c-erbB-2, and PCNA in barrett's esophagus with dysplasia and adenocarcinoma arising from experimental acid or alkaline reflux model.
PURPOSE: An immunohistochemical study of p53, c-erbB-2, and proliferating cell nuclear antigen (PCNA) in Barrett's esophagus with dysplasia and adenocarcinoma, arising from experimental acid or alkaline reflux, was performed in dogs. METHODS: Cardiectomy was performed in group A (n = 26) as an acid reflux model, and total gastrectomy was performed in group B (n = 24) as an alkaline reflux model. After surgery, the esophageal mucosa was observed and biopsied endoscopically every 3 months over a period of 6 years. Immunohistochemical staining of p53. c-erbB-2, and PCNA was performed, using biopsied specimens. RESULTS: In group A, Barrett's esophagus developed in 14 of the 26 dogs. Low-grade dysplasia occurred in 5 of the 26 dogs, and in 1 of these 5 dogs, it developed into high-grade dysplasia. In this animal, adenocarcinoma arose 63 months after the operation. In group B, Barrett's esophagus developed in 10 of the 24 dogs. Low-grade dysplasia was observed in 4 of the 24 dogs. In 1 of these 4 dogs, the dysplasia became high-grade and adenocarcinoma occurred 66 months after the operation. In group A, PCNA was positive in adenocarcinoma; the PCNA labeling index (LI) was 58. c-erbB-2 and p53 were negative in all animals in group A. In group B, PCNA was positive in Barrett's esophagus with high-grade dysplasia and adenocarcinoma; the PCNA LI was 77. p53 was positive in adenocarcinoma. c-erbB-2 was negative in adenocarcinoma. CONCLUSIONS; The results of this study provided evidence of the dysplasia-carcinoma sequence arising from alkaline reflux, as well as from acid reflux. To the best of our knowledge, this is the first report of the use of an alkaline reflux model and a 6-year study using dogs to observe the course of Barrett's esophagus.
Adenocarcinoma↗
Concomitant duodenal and pancreatic metastases from renal cell carcinoma: report of a case.
The pancreas and duodenum are uncommon sites for metastasis from renal cell carcinoma. Pancreatic or small intestinal metastases mainly occur when there is widespread nodal and visceral involvement and evidence of metastatic disease elsewhere in the body. We describe herein the case of a 68-year-old man in whom metastases arising from renal cell carcinoma developed concomitantly in the duodenum and pancreas. The patient presented with duodenal bleeding; but as no other metastatic lesions were observed at the time of surgery, total pancreatectomy with duodenetomy was performed. We believe that metastases may easily develop in the duodenum and pancreas owing to the similar tissue characteristics.
Aged↗
Requirement of nef for HIV-1 infectivity is biased by the expression levels of Env in the virus-producing cells and CD4 in the target cells.
The nef gene of human immunodeficiency virus type 1 (HIV-1) encodes a 27 to 34 kDa myristoylated protein, which enhances viral infectivity in a single-round infection assay. The level of Nef enhancement of HIV-1 infectivity depends on the viral strains, on the target cells, and on the cells used for propagating the viruses. In this study, we aimed at clarifying the molecular basis of these differences in the requirement for Nef. We found that the requirement for Nef was increased when we decreased the quantity of Env protein in the virus-producing cells or the quantity of CD4 in the target cells. Both the wild-type and Nef-defective HIV-1 viruses were propagated in 293T cells, which did not express any CD4; therefore, Nef-induced CD4 down-regulation did not explain this phenomenon. Moreover, we did not observe any increase in the viral entry or fusion activity of gp120env in the wild-type HIV-1 compared to that in the Nef-defective HIV-1. Thus, we propose that Env on the virion and CD4 on the target cells have inhibitory effects on the post-entry step of the HIV-1 replication cycle, and that Nef functions to counteract this negative effect.
CD4 Antigens↗
Chlorinated persistent organic pollutants in black-tailed gulls (Larus crassirostris) from Hokkaido, Japan.
Concentrations and patterns of several chlorinated persistent organic pollutants (POPs) including polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) and DDTs, HCHs, CHLs and HCB were determined in black-tailed gulls (Larus crassirostris) from breeding grounds in Hokkaido, Japan. Subcutaneous fat of five adult gulls was analyzed, which had different concentrations of target compounds, whereas gull eggs contained similar concentrations of target compounds. Similar congener profiles were found between adult gulls and eggs. The concentrations of non-ortho PCBs varied from 3.4 to 13.5 ng/g lipid weight (lw) in the fat of black-tailed gulls and from 2.4 to 7.4 ng/g lw in their eggs. 2,3,7,8-PCDD/Fs occurred at relatively lower concentrations than non-ortho PCB congeners in both adult gulls and eggs. The total TEQs (toxic equivalents, PCDD/Fs+ non-ortho PCB) ranged from 0.26 to 1.0 ng/g lw in adult gulls and ranged from 0.19 to 0.58 ng/g lw in eggs.
Adipose Tissue↗
Establishment of a MAGI-derived indicator cell line that detects the Nef enhancement of HIV-1 infectivity with high sensitivity.
The Nef protein of the simian and human immunodeficiency viruses (SIV and HIV) is regarded as one of the critical determinants of the pathogenicity of HIV-1 in vivo. The positive effect of Nef on viral replication is examined most easily in vitro by the use of indicator cells such as HeLa-CD4-LTR-beta-gal cells (MAGI) or MAGIC5 cells, which are MAGI-derived, CCR5-expressing cells. However, Nef increases the infectivity of many HIV-1 strains no more than 10-fold in these indicator cells. It was noted that MAGI cells expressing a lower level of CD4 enabled us to discriminate more clearly between wild-type and Nef-defective virions. A MAGIC5-derived cell line, MAGNEF, which stably expressed a low level of CD4, was established. The infectivity of the Nef-defective HIV-1 NL4-3 strain was consistently less than one-twentieth of that of the wild type in MAGNEF cells. By using MAGNEF cells, it was shown that Nef enhanced the infectivity of a subtype C HIV-1, Indie-C1 strain, although the effect of Nef on Indie-C1 was significantly less than that on the subtype B strains NL4-3 and SF2. These results validate the versatility of MAGNEF cells for use in the simple and sensitive assay for the level of Nef dependence of various HIV-1 isolates.
CD4 Antigens↗
Analysis of anti-rotavirus activity of extract from Stevia rebaudiana.
Anti-human rotavirus (HRV) activity of hot water extracts from Stevia rebaudiana (SE) was examined. SE inhibited the replication of all four serotypes of HRV in vitro. This inhibitory effect of SE was not reduced on the prior exposure of SE to HCl for 30 min at pH 2. Binding assay with radiolabeled purified viruses indicated that the inhibitory mechanism of SE is the blockade of virus binding. The SE inhibited the binding of anti-VP7 monoclonal antibody to HRV-infected MA104 cells. The inhibitory components of SE were found to be heterogeneous anionic polysaccharides with different ion charges. The component analyses suggested that the purified fraction named as Stevian with the highest inhibitory activity consists of the anionic polysaccharide with molecular weight of 9800, and contains Ser and Ala as amino acids. Analyses of sugar residues suggest uronic acid(s) as sugar components. It did not contain amino and neutral sugars and sulfate residues. These findings suggest that SE may bind to 37 kD VP7 and interfere with the binding of VP7 to the cellular receptors by steric hindrance, which results in the blockade of the virus attachment to cells.
Animals↗
Comparison of the value of pulsed-field gel electrophoresis, random amplified polymorphic DNA and amplified rDNA restriction analysis for subtyping Taylorella equigenitalis.
Eight strains of Taylorella equigenitalis were identified by a polymerase chain reaction using a primer pair specific to the 16S rDNA of T equigenitalis. These eight strains were chosen because they had previously been shown to represent eight distinct genotypes by pulsed-field gel electrophoresis analysis after separate digestion of the genomic DNA with ApaI or NotI. The eight strains could be classified into six or seven types by random amplified polymorphic DNA analysis using different kinds of primers. Amplified rDNA restriction analysis after separate digestion with five restriction enzymes, including AluI and MboI, of the 1,500 bp fragments of rDNA amplified by polymerase chain reaction did not discriminate the genomic variations among the eight strains of T equigenitalis. Thus, pulsed-field gel electrophoresis was shown to discriminate these eight organisms better than random amplified polymorphic DNA analysis, while amplified rDNA restriction analysis was found to be unsuitable for subtyping T equigenitalis.
Animals↗
Late dissemination of fourth ventricle ependymoma: a case report.
Dissemination of benign ependymoma is relatively rare, especially when a local tumor is under control. The majority of the failures take place within a few years after surgery. However, we experienced a case in which multiple spinal cord dissemination was found 13 years after resection of the fourth ventricle ependymoma without a local failure. A 38-year-old man had undergone a subtotal resection of the fourth ventricle ependymoma and radiation therapy to the posterior fossa when he was 25 years old. Follow-up MR imaging repeated once every one or two years detected no recurrence until he began to complain of lumbago and numbness of the right foot 13 years after the surgery. MR imaging revealed multiple nodules along the whole spinal cord. Examination of the cerebrospinal fluid detected tumor cells with ependymal cell features. He underwent radiation therapy to the whole spine, and remained stable at 18 months after the therapy. This case alerts us to the necessity for long-term radiological follow-up including the spinal cord even in benign ependymomas, although it is still not certain for how long and how often we should do it.
Adult↗
Gene-centromere mapping of medaka sex chromosomes using triploid hybrids between Oryzias latipes and O. luzonensis.
Four sex-linked genetic markers (SL1, SL2, B2.38 and stsOPQ05-1) on the sex chromosomes of the medaka, O. latipes, were mapped in relation to the centromere by means of triploid hybrids between O. latipes and O. luzonensis. Female F1 hybrid O. latipes of two inbred strains, Hd-rR and HNI, were crossed with male O. luzonensis. Triploidization was induced by heat-shock treatment. Hatching rate of heat-shock treated eggs was 59%, and that of untreated hybrid eggs was 2%, indicating that most of the hatched fry were triploid. Using these triploid hatched fry, the map distances between the four loci and the centromere were examined. The order was SL2 - centromere - SL1 - B2.38 - stsOPQ05-1 and the map distances were: SL2 - centromere, 1%; centromere - SL1, 18%; SL1 - B2.38, 19%; B2.38 - stsOPQ05-1, 9%. Previous studies using FISH showed that SL2 is located on the short arm of large submetacentric chromosomes, and SL1 was closely linked to SDF (sex-determining factor). The results of gene-centromere mapping of this study show that SL1, B2.38 and stsOPQ05-1 are located on the long arm, and that. SDF is thus also on the long arm of the sex chromosomes.
Animals↗
Demonstration of heterogeneous genotypes of Taylorella equigenitalis isolated from horses in six European countries by pulsed-field gel electrophoresis.
Forty-six isolates of Taylorella equigenitalis were analysed by pulsed-field gel electrophoresis (PFGE) after separate digestion of the genomic DNA with ApaI and with NotI. The isolates had been obtained from horses in six European countries and were classified into 18 genotypes. In Belgium, 2 genotypes were detected in 2 isolates, in England 9 among 15, in Finland 2 in 2, in France 2 among 10, in Sweden 3 among 5, and in Switzerland 3 among 12. Two English isolates and 4 French isolates gave identical PFGE profiles to those of Kentucky 188 from the United States. A common genotype was found in 5 isolates from Belgium and England and also in 10 isolates from France and Switzerland. The analysis of genomic DNA from 12 isolates of T equigenitalis obtained from male horses in France, Sweden and Switzerland gave no evidence of a sex-related difference in the genomic DNA. Genomic DNA from 11 streptomycin (STM)-susceptible isolates obtained in Sweden and Switzerland were classified into four genotypes by PFGE. Each of the six genotypes determined among the 17 isolates from these two countries had single phenotypes for resistance or susceptibility to STM.
Animals↗
Detection of myeloperoxidase gene expression by in situ hybridization in a case of granulocytic sarcoma associated with AML-MO.
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Acute Disease↗
Neuroimaging of histamine H1-receptor occupancy in human brain by positron emission tomography (PET): a comparative study of ebastine, a second-generation antihistamine, and (+)-chlorpheniramine, a classical antihistamine.
AIMS: Sedation induced by antihistamines is widely recognized to be caused by their penetration through the blood-brain-barrier and the consequent occupation of brain histamine H1-receptors. We previously studied the mechanism of sedation caused by antihistamines using positron emission tomography (PET). Recently, we revealed the nonsedative characteristic of ebastine, a second-generation antihistamine, with cognitive performance tests. In the present study, H1-receptor occupation by ebastine was examined in the human brain using PET. METHODS: Ebastine 10 mg and (+)-chlorpheniramine 2 or 6 mg were orally given to healthy male volunteers. PET scans with [11C]-doxepin, a potent H1-receptor antagonist, were conducted near tmax of respective drugs. Other volunteers in the control group also received PET scans. The binding potential of doxepin (BP = Bmax/Kd) for available brain H1-receptors was imaged on a voxel-by-voxel basis through graphical analysis. By setting regions of interest, the H1-receptor occupancy of drugs was calculated in several H1-receptor rich regions. RESULTS: Brain distribution of radioactivity after ebastine treatment was similar to that without any drugs. However, after the oral administration of 2 mg (+)-chlorpheniramine, the level was lower than after ebastine and nondrug treatments. Graphical analysis followed by statistical parametric mapping (SPM96) revealed that H1-receptor rich regions such as cortices, cingulate gyrus and thalamus were regions where the BPs after ebastine were significantly higher than after (+)-chlorpheniramine (2 mg). H1-receptor occupancies in cortex were approximately 10% by ebastine and > or = 50% by either dose of (+)-chlorpheniramine (95% confidence interval for difference in the mean receptor occupancies: 27%, 54% for 2 mg and 35%, 62% for 6 mg vs ebastine, respectively). Receptor occupancies increased with increasing plasma concentration of (+)-chlorpheniramine, but not with concentration of carebastine, an active metabolite of ebastine. CONCLUSIONS: Ebastine (10 mg orally) causes brain histamine H1-receptor occupation of approximately 10%, consistent with its lower incidence of sedative effect, whereas (+)-chlorpheniramine occupied about 50% of brain H1-receptors even at a low but sedative dose of 2 mg; occupancy of (+)-chlorpheniramine was correlated with plasma (+)-chlorpheniramine concentration.
Adult↗