Biomedical subjects

M Takata

Publications and source records attributed to M Takata.

At least 91 records · Page 5Linked to original sources

PubMed1999

High frequency of DNA aneuploidy detected by DNA flow cytometry in Bowen's disease.

To detect DNA aneuploidy in Bowen's disease, we investigated DNA flow cytometric analysis. Single cell suspensions were prepared from 18 fresh samples histopathologically diagnosed as solitary Bowen's disease and analyzed by DNA flow cytometry. In 16 (89%) of 18 lesions, DNA aneuploidy was demonstrated with a single aneuploid peak. DNA indices ranged from 1.29 to 1.74. The incidence of DNA aneuploidy in Bowen's disease is higher than those of cutaneous squamous cell carcinoma, which was 25-80% in the previous reports. Therefore, in Bowen's disease. DNA aneuploidy may not imply a good marker for characteristics of non-melanoma skin cancer. A single aneuploid peak commonly observed in Bowen's disease suggests that this disease consists of the monoclonal proliferation of keratinocytes containing abnormal DNA content.

Aged↗

PubMed1999

Antiepiligrin (laminin 5) cicatricial pemphigoid associated with an underlying gastric carcinoma producing laminin 5.

Although bullous pemphigoid and cicatricial pemphigoid are sometimes associated with malignancy, it remains uncertain whether such an association is pathogenetically related or just a coincidence attributable to the advanced age of the patients. We report a 61-year-old patient with antiepiligrin (laminin 5) cicatricial pemphigoid (AeCP) associated with an advanced gastric carcinoma. The gastric carcinoma cells in this patient were shown to produce laminin 5 by immunofluorescence microscopy, and the patient's serum contained autoantibodies directed against laminin 5 on immunoprecipitation. Furthermore, the blistering symptoms and the titre of antibasement membrane zone antibodies coordinately changed with the resection and subsequent relapse of the gastric cancer. These observations suggest that the gastric carcinoma producing laminin 5 may have induced the production of autoantibodies to this laminin, which were pathogenic to the skin and mucous membranes in this patient. This report demonstrates a link between this autoimmune subepithelial blistering disease and malignancy. It is of interest and potential great importance to examine other cases of AeCP for such a potential association.

Adenocarcinoma↗

PubMed1999

The association of latent Epstein-Barr virus infection with hydroa vacciniforme.

Patients with hydroa vacciniforme (HV)-like eruptions and malignant potential have been reported from Asia and Mexico, and those patients frequently had an associated latent Epstein-Barr virus (EBV) infection. In order to elucidate the association of latent EBV infection with HV, we studied six children with typical manifestations of HV by detection of EBV genes and EBV-related RNAs in biopsy specimens from cutaneous lesions. Cutaneous lesions of all six children with typical HV contained EBV-encoded small nuclear RNA (EBER)+ cells in 3-10% of the dermal infiltrates, whereas no Bam HI-H, l-fragment (BHLF) mRNA, or transcripts encoding EA-D antigen, were detected. No EBER + cells were detected in other inflammatory or benign lymphoproliferative skin disorders tested. Polymerase chain reaction amplification confirmed the presence of EBV DNA sequences in five of six biopsy specimens from the patients. Latent EBV infection is associated with the development of cutaneous lesions of HV.

Burkitt Lymphoma↗

PubMed1999

erbB-2 overexpression but no activation of beta-Catenin gene in extramammary Paget's disease.

Our previous study in extramammary Paget's disease showed neither p53 mutations nor allelic loss at selected loci implicated in other cancers, suggesting a pathogenesis of this skin cancer different from other common epithelial malignancies. To examine further the genetic defects in extramammary Paget's disease, we carried out molecular genetic analyses in 31 tumor samples obtained from 27 cases of extramammary Paget's disease without underlying malignancies. Immunohistochemistry using CB-11 monoclonal antibody revealed either membrane or cytoplasmic erbB-2 oncoprotein overexpression in none of the 13 primary in situ tumors, but in one recurrent in situ tumor, 10 of 13 invasive primary tumors and two of four lymph node metastases. Sensitive dual color fluorescence in situ hybridization analysis using probes for erbB-2 gene locus and chromosome 17 pericentromere, however, revealed different erbB-2 gene status in the erbB-2 overexpressing tumors. One recurrent in situ tumor and one lymph node metastasis showed definite gene amplification characterized by multiple scattered signals or a few large clustered erbB-2 signals, whereas four tumors with predominantly cytoplasmic erbB-2 overexpression were thought to have low-grade gene amplification. The remaining six tumors overexpressing erbB-2 showed no increase of erbB-2 copy numbers. No evidence of abnormal activation of the beta-catenin gene, a critical mediator of Wnt signaling pathway, in any tumor by immunohistochemical staining and by direct sequencing and reverse transcription-polymerase chain reaction analysis was found. Frequent overexpression of erbB-2 by either gene amplification or possible transcriptional activation in invasive primary tumors and metastases suggests an important part for this oncogene in the progression of extramammary Paget's disease.

Aged↗

PubMed1999

A rare case of sarcoidosis with bilateral leg lymphedema as an initial symptom.

A 55-year-old man was admitted to our hospital because of bilateral leg lymphedema. He also showed subcutaneous nodules and CT scan disclosed multiple enlarged lymph nodes at thoracic, abdominal, and inguinal areas. Biopsy of the inguinal lymph node and the subcutaneous nodule revealed noncaseating epithelioid cell granuloma, a finding consistent with sarcoidosis. Lymphedema was attributed to the blockade of lymph flow by the systemic lymph node involvement of the disease. Within 1 week after the initiation of steroid therapy, his leg edema disappeared. Lymphedema could be the initial symptom of systemic sarcoidosis.

Diagnosis, Differential↗

PubMed1999

Congenital NOS2 deficiency protects mice from LPS-induced hyporesponsiveness to inhaled nitric oxide.

BACKGROUND: In animal models, endotoxin (lipopolysaccharide) challenge impairs the pulmonary vasodilator response to inhaled nitric oxide (NO). This impairment is prevented by treatment with inhibitors of NO synthase 2 (NOS2), including glucocorticoids and L-arginine analogs. However, because these inhibitors are not specific for NOS2, the role of this enzyme in the impairment of NO responsiveness by lipopolysaccharide remains incompletely defined. METHODS: To investigate the role of NOS2 in the development of lipopolysaccharide-induced impairment of NO responsiveness, the authors measured the vasodilator response to inhalation of 0.4, 4, and 40 ppm NO in isolated, perfused, and ventilated lungs obtained from lipopolysaccharide-pretreated (50 mg/kg intraperitoneally 16 h before lung perfusion) and untreated wild-type and NOS2-deficient mice. The authors also evaluated the effects of breathing NO for 16 h on pulmonary vascular responsiveness during subsequent ventilation with NO. RESULTS: In wild-type mice, lipopolysaccharide challenge impaired the pulmonary vasodilator response to 0.4 and 4 ppm NO (reduced 79% and 45%, respectively, P < 0.001), but not to 40 ppm. In contrast, lipopolysaccharide administration did not impair the vasodilator response to inhaled NO in NOS2-deficient mice. Breathing 20 ppm NO for 16 h decreased the vasodilator response to subsequent ventilation with NO in lipopolysaccharide-pretreated NOS2-deficient mice, but not in lipopolysaccharide-pretreated wild-type, untreated NOS2-deficient or untreated wild-type mice. CONCLUSIONS: In response to endotoxin challenge, NO, either endogenously produced by NOS2 in wild-type mice or added to the air inhaled by NOS2-deficient mice, is necessary to impair vascular responsiveness to inhaled NO. Prolonged NO breathing, without endotoxin, does not impair vasodilation in response to subsequent NO inhalation. These results suggest that NO, plus other lipopolysaccharide-induced products, are necessary to impair responsiveness to inhaled NO in a murine sepsis model.

Administration, Inhalation↗

PubMed1999

Effects of a novel calcium antagonist, benidipine hydrochloride, on platelet responsiveness to mental stress in patients with essential hypertension.

The effects of a novel calcium antagonist, benidipine hydrochloride, on responses of platelets to mental stress were evaluated in nine patients with essential hypertension. Before and 12 weeks after the monotherapy with benidipine (2-4 mg/day), platelet aggregability and plasma beta-thromboglobulin were determined during rest and after a 10-min arithmetic stress. Before the treatment, arithmetic stress significantly increased platelet aggregability in response to adenosine diphosphate (ADP) and plasma beta-thromboglobulin level. Blood pressure, pulse rate, and plasma catecholamines also increased during arithmetic stress. The treatment with benidipine did not affect resting values of platelet functions, but attenuated significantly stress-induced alterations in primary aggregation to 1.0 microM ADP (34 +/- 4% to 40 +/- 3% before treatment vs. 32 +/- 2% to 34 +/- 3% after benidipine), ADP threshold for biphasic aggregation (2.2 +/- 0.4 to 1.8 +/- 0.3 microM before treatment vs. 2.2 +/- 0.3 to 2.2 +/- 0.4 microM after benidipine) and plasma beta-thromboglobulin level (74 +/- 16 to 104 +/- 15 ng/ml before treatment vs. 60 +/- 10 to 52 +/- 8 ng/ml after benidipine; p < 0.05 for Stress x Treatment interactions in all values). The pretreatment elevations in blood pressure and sympathetic activity with stress were not modified by benidipine treatment. In conclusion, the monotherapy with benidipine did not affect platelet function during the resting condition, but significantly suppressed the platelet activation induced by arithmetic stress in patients with essential hypertension.

Adult↗

PubMed1999

Time course of the effects of temocapril on cardiovascular structure and function in patients with essential hypertension.

To investigate the time course of cardiovascular structural changes in patients with essential hypertension after angiotensin-converting enzyme (ACE) inhibition, we determined left ventricular structure, minimal vascular resistance in the forearm as an index of resistance vessel structure and stiffness beta of carotid artery in 15 essential hypertensive subjects during a placebo period and after 2, 6, and 12 months of temocapril treatment. Blood pressure decreased within 2 weeks, and the antihypertensive effects were noted throughout the 12-month administration period. Left ventricular mass index decreased significantly after 2 months (120+/-12 to 106+/-9 g/m2; p < 0.01) and was normalized after 12 months (88+/-6 g/m2). Postischemic minimal vascular resistance in the forearm decreased gradually from 2.1+/-0.5 to 1.6+/-0.4 PRU at month 12 of temocapril treatment. In contrast, increased stiffness index beta of carotid artery was not altered during a 1-year treatment period (11.4+/-4.9 to 11.6+/-3.8 at month 12 of treatment). These data indicated that the regression of structural changes of left ventricle and arterioles occurred gradually and progressively for 1-year treatment with ACE inhibition, but large arteries were not affected.

Adult↗

PubMed1999

Mapping of occult melanoma micrometastases in the inguinal lymph node basin by immunohistochemistry and RT-PCR.

To examine the distribution of occult micrometastases that could be potential sources of recurrence, complete maps of microscopic and submicroscopic metastases in entire inguinal lymph node basins were generated in 13 melanoma patients who had undergone elective or therapeutic lymphadenectomy. Occult micrometastases were analysed immunohistochemically for the pigment cell-specific antigen HMB-45 in all 155 nodes and using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay to detect tyrosinase mRNA in 35 nodes. Five patients were determined to be node-negative by routine histopathology; three of these subjects were also negative by RT-PCR and/or immunohistochemistry. However, the remaining two patients had occult metastases, which were confined to a possibly sentinel node in one and were detected in multiple nodes in the other. Eight patients had histological evidence of lymph node metastasis. Three of these patients had no additional detectable submicroscopic disease, and one had occult metastasis in one node adjacent to the histologically positive node. In contrast, the other four patients had occult micrometastases in multiple non-sentinel, higher level nodes. The two patients who relapsed belonged to this group. The results show considerable variation in the distribution pattern of occult metastases in the regional lymph nodes, and have significant implications for the role of regional lymph node dissection, including sentinel node mapping with selective lymphadenectomy, in the management of melanoma patients.

Adult↗

PubMed1999

The essential functions of human Rad51 are independent of ATP hydrolysis.

Genetic recombination and the repair of double-strand DNA breaks in Saccharomyces cerevisiae require Rad51, a homologue of the Escherichia coli RecA protein. In vitro, Rad51 binds DNA to form an extended nucleoprotein filament and catalyzes the ATP-dependent exchange of DNA between molecules with homologous sequences. Vertebrate Rad51 is essential for cell proliferation. Using site-directed mutagenesis of highly conserved residues of human Rad51 (hRad51) and gene targeting of the RAD51 locus in chicken DT40 cells, we examined the importance of Rad51's highly conserved ATP-binding domain. Mutant hRad51 incapable of ATP hydrolysis (hRad51K-133R) binds DNA less efficiently than the wild type but catalyzes strand exchange between homologous DNAs. hRad51 does not need to hydrolyze ATP to allow vertebrate cell proliferation, form nuclear foci, or repair radiation-induced DNA damage. However, cells expressing hRad51K-133R show greatly reduced targeted integration frequencies. These findings show that ATP hydrolysis is involved in DNA binding by hRad51 and suggest that the extent of DNA complexed with hRad51 in nucleoprotein influences the efficiency of recombination.

Adenosine Triphosphate↗

PubMed1999

Sister chromatid exchanges are mediated by homologous recombination in vertebrate cells.

Sister chromatid exchange (SCE) frequency is a commonly used index of chromosomal stability in response to environmental or genetic mutagens. However, the mechanism generating cytologically detectable SCEs and, therefore, their prognostic value for chromosomal stability in mitotic cells remain unclear. We examined the role of the highly conserved homologous recombination (HR) pathway in SCE by measuring SCE levels in HR-defective vertebrate cells. Spontaneous and mitomycin C-induced SCE levels were significantly reduced for chicken DT40 B cells lacking the key HR genes RAD51 and RAD54 but not for nonhomologous DNA end-joining (NHEJ)-defective KU70(-/-) cells. As measured by targeted integration efficiency, reconstitution of HR activity by expression of a human RAD51 transgene restored SCE levels to normal, confirming that HR is the mechanism responsible for SCE. Our findings show that HR uses the nascent sister chromatid to repair potentially lethal DNA lesions accompanying replication, which might explain the lethality or tumorigenic potential associated with defects in HR or HR-associated proteins.

Animals↗

PubMed1999

Suppression of induction of experimental immune mediated blepharoconjunctivitis by tolerogenic conjugates of the antigen and monomethoxypolyethylene glycol.

AIM: Covalent conjugates consisting of diverse antigens coupled to optimal numbers of monomethoxypolyethylene glycol (mPEG) molecules have been shown to suppress antigen specific antibody formation. In this study, the possibility was examined that the same conjugates might prevent experimental immune mediated blepharoconjunctivitis (EC, formerly EAC) which had been shown to be caused by CD4(+) T cells-that is, to cell mediated immunity. METHODS: 6-8 week old male Lewis rats were used. The test groups of rats received two intravenous injections, each of 300 microg, of a conjugate of ovalbumin mPEG (OVA(mPEG)(11)) in phosphate buffered saline (PBS), 14 and 28 days before the single immunisation with OVA in complete Freund's adjuvant. The rats were challenged 3 weeks later by eye drops containing OVA; 24 hours later they were sacrificed, and their eyes, blood, and lymph nodes were harvested for histological examination and determination of anti-OVA antibody titres and levels of cellular immunity. Two control groups received PBS or OVA in PBS before immunisation. Furthermore, the possibility that OVA(mPEG)(11) may have induced OVA specific suppressor cells was tested by establishing the effects of the co-transfer of splenocytes from OVA(mPEG)(11) treated rats with OVA primed lymph node cells on the manifestations of EC. RESULTS: Either PBS or OVA pretreated rats, which had not received OVA(mPEG)(11), developed high levels of antibodies and cell mediated immune responses to OVA, and application of eye drops led to blepharoconjunctivitis with massive cellular infiltration. In contrast, pretreatment with OVA(mPEG)(11) prevented cellular infiltration into the lids and conjunctivas, as well as the formation of detectable humoral and cellular immunity against OVA. Co-transfer of splenocytes from OVA(mPEG)(11) treated rats with OVA primed lymph node cells suppressed the cellular infiltration on application of OVA on the conjunctiva. CONCLUSIONS: These data indicate that intravenous injection of OVA(mPEG)(11) conjugates suppressed both humoral and cellular immunity by the effects of antigen specific suppressor cells, thus leading to the inhibition of development of EC.

Animals↗

PubMed1999

Influence of increased abdominal pressure on steady-state cardiac performance.

The effect of steady-state increases in abdominal pressure (Pab) on cardiac performance was studied in seven acutely instrumented swine with pneumoperitoneum (PP). The animal was placed on volume-preset ventilation, and PP was created by air insufflation. Cardiac output (CO), right atrial (Pra), left atrial (Pla), pericardial (Ppe), and abdominal inferior vena cava pressures (Pivc) were measured while Pab was increased from baseline to 7.5, 15, and 30 mmHg (PP7.5, PP15, and PP30, respectively). Cardiac function curves of the right and left ventricle (RV and LV, respectively) were compared between baseline and PP30. CO presented biphasic changes, with an inital slight increase at PP7.5 followed by a fall at PP30. A significant discrepancy was observed between Pra and Pivc at PP15 and PP30, consistent with development of a "vascular waterfall." Transmural Pla (Pla - Ppe) showed parallel changes with CO, whereas transmural Pra (Pra - Ppe) exhibited a sustained increase. The RV cardiac-function curve was more depressed than was that of the LV at PP30; this suggests an increased RV afterload produced by the elevated airway pressure. These results support the hypothesis that our previously proposed concept of abdominal vascular zone conditions (M. Takata, R. A. Wise, and J. L. Robotham. J. Appl. Physiol. 69: 1961-1972, 1990) is also applicable to steady-state hemodynamic analyses. The abdominal zones appear to play an important role in determining CO, with increases in Pab, by modulating systemic venous return and the LV preload. Simultaneous measurements of Pra and Pivc may provide useful information in the hemodynamic care of patients with elevated Pab.

Abdomen↗

PubMed1999

Intratracheal anti-tumor necrosis factor-alpha antibody attenuates ventilator-induced lung injury in rabbits.

To evaluate the role of tumor necrosis factor (TNF)-alpha in the pathogenesis of ventilator-induced lung injury, we 1) measured TNF-alpha production in the lung caused by conventional mechanical ventilation (CMV) and 2) evaluated the protective effect of anti-TNF-alpha antibody (Ab) in saline-lavaged rabbit lungs. After they received saline lung lavage, rabbits were intratracheally instilled with 1 mg/kg of polyclonal anti-TNF-alpha Ab in the high-dose group (n = 6), 0.2 mg/kg of anti-TNF-alpha Ab in the low-dose group (n = 6), serum IgG fraction in the Ab control group (n = 6), and saline in the saline control group (n = 7). Animals then underwent CMV for 4 h. Levels of TNF-alpha in lung lavage fluid were significantly higher after CMV than before in both control groups. Pretreatment with intratracheal instillation of high and low doses of anti-TNF-alpha Ab improved oxygenation and respiratory compliance, reduced the infiltration of leukocytes, and ameliorated pathological findings. CMV led to TNF-alpha production in the lungs, and intratracheal instillation of anti-TNF-alpha Ab attenuated CMV-induced lung injury in this model.

Acute-Phase Reaction↗

PubMed1999

Clinical experience of long-term transdermal treatment with nitric oxide donor for women with preeclampsia.

Isosorbide dinitrate (ISDN), a nitric oxide donor, was applied transdermally for 4-16 days to 4 preeclamptic women with oligohydramnios, intrauterine fetal growth retardation (IUGR), and elevated resistance of blood flow in the uterine arteries. Pulsed Doppler ultrasonography revealed immediate and drastic improvement of pulsatility index (PI) of uterine arteries following treatment with ISDN. The average PI in uterine arteries of the 4 patients was reduced to approximately 67% of that of the untreated state. In 2 patients the amniotic fluid gradually increased over a few days which suggested improvement of fetoplacental circulation during administration of ISDN. This study suggests that long-term transdermal ISDN is an effective therapy, at least in a portion of preeclamptic women, to avoid maternal hypertension, fetal distress, oligohydramnios, and IUGR, and consequentially to prolong the gestational period.

Administration, Cutaneous↗

PubMed1999

Cytogenetic mapping of 31 functional genes on chicken chromosomes by direct R-banding FISH.

Using direct R-banding fluorescence in situ hybridization, we determined the location of 31 functional genes on chicken chromosomes. Replication R-banded chromosomes were obtained by synchronizing splenocyte cultures with excessive thymidine, followed by BrdU treatment. Thirty-one functional genes were directly localized to banded chicken chromosomes using genomic DNA and cDNA fragments as probes. The possibility of conserved linkage homology between chicken and human chromosomes was demonstrated for seven chicken chromosome regions (1p, 1q, 2q, 4p, 4q, and 5q).

Animals↗

PubMed1999

Effect of the platelet-derived growth factor antagonist trapidil on mesangial cell proliferation in rats.

Platelet-derived growth factor (PDGF) is known as a potent mediator in the proliferation of mesangial cells in culture and in mesangial proliferative nephritis. The present study was undertaken to evaluate the effect of trapidil, an antagonist of PDGF, on mesangial cell proliferation in culture and in anti-Thy-1.1 nephritis in rats. Trapidil significantly inhibited 3H-thymidine incorporation in the mesangial cells stimulated by PDGF BB and suppressed mesangial cell proliferation in culture in a dose-dependent manner. In anti-Thy-1.1 nephritis, a significant reduction in the number of total glomerular cells and also proliferating (proliferating cell nuclear antigen positive) cells was demonstrated on day 7 in the rats treated with trapidil as compared with controls. Although renal function expressed as blood urea nitrogen and creatinine levels did not differ between rats with and without trapidil treatment, the present results suggest a salutary effect of trapidil on mesangial cell proliferation. PDGF, therefore, could play an important role in mediating mesangial cell proliferation.

Animals↗

PubMed1999

Different effects of temocapril and cadralazine on electrocardiographic voltages and left ventricular mass in patients with essential hypertension.

To assess whether electrocardiographic variables are useful to detect the regression of left ventricular (LV) mass after long-term antihypertensive treatment, we related electrocardiographic voltages to echocardiographic variables before and after treatment with an ACE inhibitor, temocapril (TEM), or direct vasodilator, cadralazine (CAD). Twenty-one patients with essential hypertension were treated with either TEM (n = 11) or CAD (n = 10) for one year. LV mass index (LVMI) by echocardiography and Sokolow-Lyon voltage (SV1 + RV5), Cornell voltage (RaVL + SV3) and RV5 + RV6 by standard 12-lead electrocardiographic voltages were determined before and after treatment. Both drugs decreased blood pressure to the same extent. Both Sokolow-Lyon voltage and RV5 + RV6 tended to decrease in the ACE group (40.0 +/- 9.4 to 37.2 +/- 9.4 mm and 44.7 +/- 13.5 to 41.7 +/- 11.7 mm, respectively, N.S.), but not in the CAD group (38.4 +/- 6.8 to 39.7 +/- 7.7 mm and 42.9 +/- 10.4 to 46.8 +/- 11.2 mm, respectively, N.S.). LVMI decreased in the ACE group (-24 +/- 22 g/m2), whereas it increased in the CAD group (37 +/- 27 g/m2, p < 0.01). Change in LVMI was correlated with the changes in RV5 + RV6 and Sokolow-Lyon voltage (r = 0.73, p < 0.01 and r = 0.70, p < 0.01, respectively), but not with that in Cornell voltage. These results indicated that the changes in voltage criteria of RV5 + RV6 and Sokolow-Lyon are useful to assess the change in LVM after antihypertensive treatment in patients with essential hypertension although voltage variables in electrocardiogram were not sensitive to detect changes in LVMI.

Aged↗