Biomedical subjects

T Kaku

Publications and source records attributed to T Kaku.

At least 73 records · Page 4Linked to original sources

PubMed1997

The significance of peritoneal cytology in uterine cervix and endometrial cancer.

OBJECTIVE: The purpose of this study was to determine the incidence of positive peritoneal cytology and to elucidate the prognostic value of peritoneal cytology in patients with uterine cervix and endometrial cancer. MATERIALS AND METHODS: The incidence of positive peritoneal cytology was investigated in 642 patients including 339 uterine cervix and 303 endometrial cancers. Survival was estimated by the Kaplan-Meier method in a subgroup of 116 stage II cervix and 199 stage I endometrial cancers, and multivariate analysis using Cox's proportional hazards model was used to identify an independent prognostic factor. RESULTS: The incidence of positive peritoneal cytology was found to be 9% in uterine cervix cancer and 15% in endometrial cancer. The incidence was higher in patients with some clinicopathologic status such as advanced stage, lymph node metastasis, ovarian metastasis, and deeper myometrial invasion. The 5-year survival rate for patients with positive or negative peritoneal cytology was 44 or 80% in stage II cervix cancers and 80 or 92% in clinical stage I endometrial cancers, respectively. Multivariate analysis revealed that independent prognostic determinants were pelvic and paraaortic lymph node metastasis and peritoneal cytology in stage II cervix cancer and peritoneal cytology in stage I endometrial cancer. Proper treatment protocol should be scheduled for patients with positive peritoneal cytology.

Endometrial Neoplasms↗

PubMed1997

Changes in the expression of gap junction proteins (connexins) in hamster tongue epithelium during wound healing and carcinogenesis.

We examined changes in the expression and localization of connexin proteins and transcripts by means of immunofluorescence and in situ hybridization in normal conditions, wound healing and carcinogenesis using hamster tongue epithelium, in which differentiation, migration and growth of keratinocytes takes place physiologically and pathologically. In normal hamster tongue epithelium, immunofluorescent staining showed that Cx26 and Cx43 proteins were localized differently during differentiation of keratinocytes, but in in situ hybridization, the localization of Cx26 and Cx43 transcripts overlapped considerably, suggesting that the different localization of Cx26 and Cx43 proteins in squamous epithelium is largely regulated at post-transcriptional levels. During wound healing, the expression and localization of connexin proteins and transcripts were changed drastically. Shortly (6 h) after injury the expression of Cx26 and Cx43 proteins decreased at wound edges, but by 1-3 days after injury the expression of both proteins increased and both proteins co-localized to the same spots in the epithelium near wound edges. During carcinogenesis, the increased expression of Cx26 and Cx43 proteins and their transcripts and co-localization of both proteins occurred in papillomas, and the expression of Cx26 was reduced as cancer cells became morphologically less differentiated. We also found, that during wound healing in papillomas, squamous cell carcinomas and keratinocytes, Cx26 and Cx43 proteins were localized aberrantly in the cytoplasm, especially around nuclei, rather than on plasma membranes. These results indicate that quantitative and qualitative changes in connexin expression are associated with differentiation, migration and proliferation of keratinocytes in squamous epithelium.

Animals↗

PubMed1997

Basaloid-squamous cell carcinoma of the floor of the mouth: characterization of a cell line.

Since it was first described in 1986, basaloid-squamous cell carcinoma (BSC) has been considered a distinct variant of squamous cell carcinoma that occurs in a variety of anatomic sites, including the head and neck region. We report the characterization of the first cell line established from a basaloid-squamous cell carcinoma of the floor of the mouth. The cell line exhibited a highly invasive capacity, indicating that BSC has very aggressive behavior. This cell line may be a useful model for elucidation of the biological characteristics of BSC.

Actins↗

PubMed1997

Long-term treatment of indomethacin reduces vertebral bone mass and strength in ovariectomized rats.

We investigated the effect of the long-term treatment of indomethacin, on lumbar spinal bone mineral density (LSBMD), cancellous bone mass, structure, and strength of vertebral body in old ovariectomized (OVX) rats. Ten-month-old female Wistar rats were divided into five groups: the sham operated + vehicle (sham + VEH) group, the OVX + vehicle (OVX + VEH) group, the OVX + indomethacin (IN) 1.5 mg/kg/week (OVX + IN1.5) group, the OVX + IN 6.0 mg/kg/week (OVX + IN6.0) group, and the OVX + IN 15.0 mg/kg/week (OVX + IN15.0) group. IN or vehicle were given by subcutaneous injection (s.c.) three times per week. The treatments were started at 1 week after operation and continued for 24 weeks. LSBMD (L2-L5) was measured at 0, 12, and 24 weeks after the beginning of treatment. At the end of the experimental period, the animals were sacrificed, and bone histomorphometrical and biomechanical analysis of lumbar vertebral body were done. LSBMD, trabecular bone volume (BV/TV), and trabecular thickness (Tb.Th) decreased significantly in a dose-related manner with IN. In the OVX + IN15.0 group, LSBMD decreased by 12.7%, BV/TV decreased by 65.5%, and Tb.Th decreased by 32.8%, compared with the OVX + VEH group. In addition, the maximum stress in a compressive mechanical test of L4 vertebral body in OVX groups was also decreased in a dose-related manner with IN, and this value in the OVX + IN15.0 group was 31.3% lower than in the OVX + VEH group. We conclude that long-term treatment with IN accentuated the OVX-related decrease in trabecular bone mass and the compressive strength of lumbar vertebrae.

Analysis of Variance↗

PubMed1997

[Benefit of monitoring the level of blood flecainide acetate in an elderly patient with ventricular premature contractions].

A 67-year-old woman without organic heart, disease had symptomatic ventricular premature contractions. Because class Ia, Ib and IV antiarrhythmic drugs did not prevent the premature contractions, the patient was treated with flecainide acetate at a dose of 50 mg t.i.d. Adverse reactions were noted. After measurement of the blood drug level, the dose was reduced to 50 mg b.i.d. The adverse reactions disappeared, and the arrhythmia was controlled. Flecainide acetate has a relatively long blood elimination half-life and a narrow safety margin. When some antiarrhythmic drugs are used in elderly patients, blood drug level monitoring is useful in preventing adverse reactions and in designing appropriate therapy.

Aged↗

PubMed1996

Adenosine transport inhibitors enhance high K(+)-evoked taurine release from rat hippocampus.

We examined the effects of Ca(2+)-free medium containing 20 mM Mg2+, a non-selective adenosine receptor antagonist, theophylline, and adenosine transport inhibitors, dipyridamole and nitrobenzylthioinosine, on high K(+)-evoked spreading depression, glutamate, and taurine release from the rat hippocampus using brain microdialysis. High K+ alone perfusion evoked spreading depression and increased glutamate release followed by taurine efflux. Perfusion of Ca(2+)-free medium with high K+ never evoked spreading depression and decreased the high K(+)-evoked taurine release. Perfusion of theophylline (1 mM) increased the occurrence of high K(+)-evoked spreading depression and glutamate release, but did not modify taurine release. In contrast, simultaneous perfusion of dipyridamole (100 microM) and nitrobenzylthioinosine (50 microM) reduced the occurrence of spreading depression and the high K(+)-evoked glutamate release, but enhanced significantly the taurine efflux. These findings suggest that endogenous taurine with adenosine may have neuroprotective actions against high K(+)-evoked glutamate release and spreading depression in the rat hippocampus, in addition to its osmoregulatory action.

Adenosine↗

PubMed1996

A novel tumor-associated antigen expressed in human uterine and ovarian carcinomas.

BACKGROUND: A large number of monoclonal antibodies (MoAbs) against human tumor cells have been generated and it has been shown that these MoAbs are useful tools in the diagnosis and treatment of cancer patients, as well as in the basic investigation of the oncogenesis and characterization of cancer cells. METHODS: The 22-1-1 MoAb was established by cell fusion between mouse myeloma cells and spleen cells derived from mice immunized with the human uterine cervical adenocarcinoma cell line, SiSo. The tissue distribution and biologic characteristics of the 22-1-1 antigen (Ag) were examined. RESULTS: The 22-1-1 Ag was distinct from the known tumor-associated antigens such as YH 206, GA 733, CA 125, carcinoembryonic antigen, and sialyl Le(x) molecules in an expression pattern in human tumor cell lines. An immunohistochemical study revealed that 22-1-1 Ag was expressed in 87.5% of uterine cervical adenocarcinomas, 66% of uterine endometrial adenocarcinomas, and 58.8% of ovarian carcinomas. Moreover, 22-1-1 Ag was detected in 87.7% of uterine cervical squamous cell carcinomas; however, it was not detected in 87.7% of uterine cervical or ovarian tissues, except in uterine endometrial glands, in which its expression was observed at low levels. The 22-1-1 Ag was secreted into cell culture supernatant fluids and was also detected in the vaginal discharges of uterine cervical carcinoma patients. The antigenic epitope of 22-1-1 Ag was shown to be a protein with a molecular weight of 78 kilodaltons using sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. CONCLUSIONS: The 22-1-1 MoAb reactive to a novel tumor-associated antigen was generated. This Ag was expressed in cancer cells derived mainly from the uterus and ovary. Moreover, 22-1-1 Ag was associated in the vaginal discharges of uterine cervical carcinoma patients. 22-1-1 MoAb is a potential tool for the study of oncogenesis and the management of cancer patients.

Adenocarcinoma↗

PubMed1996

Endometrial carcinoma associated with hyperplasia.

The aim of this study was to clarify the relationship of endometrial hyperplasia to endometrial carcinoma. From 1979 through 1990, 115 cases of stage I-IV endometrial carcinomas treated initially by hysterectomy were reviewed histologically. Forty-two of 115 (36.3%) patients had hyperplasia in the endometrium adjacent to the carcinoma. Women with both endometrial carcinoma and hyperplasia were significantly younger than those with carcinoma without hyperplasia (P < 0.05). In a comparison of patients with carcinoma without hyperplasia, those with hyperplasia were better differentiated (P = 0.0072), and lacked deep myometrial invasion (P < 0.0001), cervical involvement (P = 0.0192), lymph-vascular space invasion (P = 0.0102), and para-aortic lymph node metastases (P = 0.0434). The presence of endometrial metaplasia (P = 0.0001). The estimated 5-year survival rates for patients with carcinoma with hyperplasia and those with carcinoma without hyperplasia were 96.55 and 73.33%, respectively (P = 0.0016). In endometrial carcinomas, the presence of endometrial hyperplasia may demonstrate a more favorable prognosis.

Adult↗

PubMed1996

Reconstruction of the posterior inferior cerebellar artery in the treatment of giant aneurysms. Report of two cases.

Two techniques of revascularizing the posterior inferior cerebellar artery (PICA) during aneurysm surgery are presented. One involves transposition of the PICA to the vertebral artery proximal to the aneurysm using a superior temporal artery (STA) as a graft. This is used in cases in which the PICA has branched off from the wall of the giant vertebral artery aneurysm. The other technique involves end-to-end anastomosis of the PICA after excision of a giant distal PICA aneurysm located at the cranial loop near the roof of the fourth ventricle. The reconstructions of the PICA described here are surgical procedures designed to preserve normal blood flow in the PICA in patients treated for giant aneurysms involving that artery.

Aged↗

PubMed1996

Endometrial carcinoma in women 65 years of age or older: a clinicopathologic study.

The purpose of this study is to clarify the clinical and pathologic features of endometrial carcinomas in women 65 years of age or older in Japan where the incidence of endometrial carcinoma is still low. Between 1979 and 1990, 24 of 164 patients with endometrial carcinoma were 65 years old or over. In addition, 41 patients 50 years of age or younger were also analyzed, comparing clinicopathologic features with those of older age group. Seventeen of 24 (71%) showed deep myometrial invasion (more than a half of the myometrium). Endometrial carcinomas in older age groups have deeper myometrial invasion, and higher histologic grade than those of younger age groups. The adjacent endometrium is usually atrophic and the presence of hyperplasia and/or metaplasia was significantly less frequent in the older group as compared with that in the younger group. Nine of these 24 patients died of disease in a relatively short follow-up period. The prognosis for the older group (expected 5-year survival 69.2%) is significantly worse than for the younger group (expected 5-year survival 94.3%) (P = 0.006). Endometrial carcinomas in patients over 65 years of age are usually of high histologic grade, and have deep myometrial invasion and an unfavorable prognosis.

Age Distribution↗

PubMed1996

Human gingival fibroblast migration promoted by platelet-derived growth factor on titanium is correlated with release of urokinase type plasminogen activator.

The purpose of this study was to examine if the migration of human gingival fibroblasts on titanium was promoted by platelet-derived growth factor (PDGF) and whether the release of urokinase-type plasminogen activator (uPA) was correlated with it. The migration of the fibroblast on titanium was significantly promoted by PDGF in a wound healing assay (p < 0.001). The promotive effect was inhibited by aprotinin, a serine protease inhibitor used for the inhibition of uPA (p < 0.001). The conditioned medium when fibroblast migration was promoted contained a higher concentration of uPA than did that of the control. These results indicated that the promotive effect of PDGF on the migration of human gingival fibroblasts on titanium was correlated with the release of uPA from the fibroblasts.

Aprotinin↗

PubMed1995

Increased susceptibility of angiographically smooth left anterior descending coronary artery to an impairment of vasoresponse to acetylcholine, and the relation between impaired vasoresponse and low-density lipoprotein cholesterol level.

In the present study, we demonstrated that the angiographically smooth LAD is more susceptible than the LC to an impairment of vasoresponse to acetylcholine, suggesting the more severe endothelial dysfunction in the LAD. We also showed that levels of LDL play a partial but important role on endothelial dysfunction.

Acetylcholine↗

PubMed1995

Novel ligand binding properties of the myoglobin substituted with monoazahemin.

The iron complex of alpha-azamesoporphyrin XIII was combined with apomyoglobin to investigate influence of the meso nitrogen on ligand binding properties in the reconstituted protein. Stoichiometric complex formation between the two components was confirmed, and conservation of the native coordination structures in the resultant myoglobin was established with spectroscopic criteria and apparently normal ligand binding. The visible absorption spectra of various ferric and ferrous derivatives are characteristic with less intense Soret peaks and enhanced visible bands. The electron paramagnetic resonance spectrum with g = 5.2 suggests an anomalous intermediate spin (S = 3/2) character for the aquomet protein. The oxygen affinity of reduced azaheme myoglobin, 0.010 mm Hg, is 50 times larger than that of the native myoglobin. In addition, azaheme myoglobin forms stable complexes with imidazole, pyridine, or cyanide in ferrous state. All of these new properties were consistently explained in terms of stronger equatorial ligand field of the heme iron in a narrower coordination cavity. Similarities of azaheme to verdoheme were also pointed out.

Carbon Dioxide↗

PubMed1995

The prognostic significance of lymphovascular space invasion in endometrial cancer when conventional hemotoxylin and eosin staining is compared to immunohistochemical staining.

The current study was undertaken to compare the usefulness of hemotoxylin and eosin (H&E) staining and immunohistochemical staining to identify lymphovascular space invasion (LVSI) in endometrial cancer and to evaluate the presence of LVSI detected by either technique as an independent prognostic factor. Histologic sections from 92 patients with clinical stage I-II endometrial cancer were reviewed, and representative sections were stained immunohistochemically with antibodies for von Willebrand factor and blood group isoantigens. To compare the prognostic significance of LVSI detected by H&E staining with that detected by immunohistochemical staining, univariate and multivariate analyses were performed. Thirty (32.6%) of the 92 cases showed LVSI in H&E staining. In 8 of the 30 cases, LVSI was negative by immunohistochemical staining, while LVSI was positive by immunohistochemical stainings in 2 of 62 cases showing negative LVSI in H&E staining. In univariate analysis, LVSI detected by H&E and immunohistochemical staining was proved to be significant as a prognostic factor. In multivariate analysis by Cox's proportional hazards model, LVSI identified by H&E staining was selected as one of significant prognostic factors, but LVSI identified by immunohistochemical staining not selected. The results of this study indicate that LVSI is one of the independent prognostic factors in endometrial cancer, and that LVSI as detected by H&E is more prognostic of survival than immunohistochemical detection.

Adult↗

PubMed1995

Effects of systolic anterior motion of the mitral valve on haemodynamics. Evaluation by a direct method.

We evaluated the effects of systolic anterior motion systolic anterior motion of the mitral valve on cardiac haemodynamics. Seven adult mongrel dogs in which systolic anterior motion-septal contact was observed after dobutamine administration were used. To exclude the effects of left ventricular function and morphology, a stone removal basket catheter was placed in the left ventricular outflow tract, and haemodynamics were compared with the basket closed and opened. The basket was opened five times in three dogs not showing systolic anterior motion-septal contact, but the basket itself did not effect the haemodynamics. In the seven dogs that showed systolic anterior motion-septal contact without left ventricular hypertrophy, the basket was opened a total of 33 times in the presence of various degrees of systolic anterior motion-septal contact. After opening the basket, systolic anterior motion was reduced echocardiographically, and significant (P<0.01) changes were observed in the left ventricle-aorta pressure gradient (from 68 +/- 22 to 25 +/- 15 mm Hg), the systolic ejection period (from 146 +/- 19 to 135 +/- 16 ms), and the stroke volume (SV; from 9.4 +/- 2.9 to 10.1 +/- 3.3 ml). After basket inflation, aortic pressure and aortic flow waveforms changed but the peak pressure and flow velocity did not. The temporal distribution of left ventricular ejection also definitely changed after the basket was opened. No changes were observed in the peak dp/dt, peak negative dp/dt, time constant, left ventricular end-diastolic pressure, or left atrial pressure. These observations in this animal model of systolic anterior motion without left ventricular hypertrophy suggest that: (1) there is no potential for generation of an intra-cavity gradient in the absence of systolic anterior motion of the mitral valve, so that (2) systolic anterior motion narrowed the left ventricular outflow tract and, consequently, produced the systolic ejection period, and affected the left ventricular ejection dynamics, and that (3) the basket catheter is useful because it allows these assessments in the same heart with a nearly fixed left ventricular contractility, at least in our animal model.

Animals↗

PubMed1994

Endogenous adenosine exerts inhibitory effects upon the development of spreading depression and glutamate release induced by microdialysis with high K+ in rat hippocampus.

Spreading depression (SD) is known to be involved in the N-methyl-D-aspartate receptor-mediated neuronal damage. In urethane-anesthetized rats, we examined the release of adenosine and glutamate during SD induced by microdialysis of high K+ perfusate through the hippocampal CA1 area. The effects of endogenous adenosine upon SD were studied by applying an adenosine antagonist, theophylline (1 mM) and by a simultaneous application of adenosine uptake blockers, dipyridamole (DPR) (100 microM) and nitrobenzylthioinosine (NBI) (50 microM). The dialysates were sampled every 5 or 10 min and analyzed by HPLC. SD was identified by flattening of background EEg and disappearance of population spikes recorded from the pyramidal cell layer of CA1 area by a glass microelectrode. Adenosine and glutamate release was enhanced significantly in association with the occurrence of SD. Theophylline increased the release of glutamate and the incidence of SD and decreased the latency of the SD occurrence. DPR+NBI decreased the release of glutamate and the occurrence of SD, but increased extracellular adenosine concentration. The effects of DPR+NBI were blocked by application of a selective antagonist of adenosine A1 receptor, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 0.1 microM). These findings suggest that endogenous adenosine exerts inhibitory influences upon the development of SD and the glutamate release through the A1 receptor in rat hippocampus.

Adenosine↗

PubMed1994

Amperometric glucose sensors based on immobilized glucose oxidase-polyquinone system.

Non-cross-linked and also cross-linked poly(ether amine quinone)s were prepared and tested for their efficiency as electron-transfer relay systems in amperometric glucose biosensors. Cyclic voltammetry and constant applied potential measurements showed that poly(ether amine quinone) relay systems efficiently mediated electron transfer from reduced glucose oxidase to a conventional carbon paste electrode. Sensors containing these relay systems respond rapidly to low (< 0.1 mM) glucose concentrations and reach steady-state current responses in less than 1 min. Electrodes constructed with cross-linked polymer and glucose oxidase were stable, indicating that the glucose oxidase was trapped in the polymer matrix and did not freely diffuse away from the electrode surface into aqueous solutions. The cross-linked polymer is a large molecular system which facilitates a flow of electrons from enzyme to the electrode, acting as an electron-transfer relay system and not as a diffusional mediator.

Biosensing Techniques↗

PubMed1994

Detection of human papillomavirus types 16 and 18 in primary and in metastatic lesions of cervical carcinomas.

Human papillomavirus (HPV) types 16 and 18 are most prevalent in cervical carcinomas and are also present in metastatic sites. Thirty-six patients with lymph node metastases were examined for the possible presence of HPV 16 and 18 DNA sequences in the primary tumors as well as in metastatic lymph nodes. Polymerase chain reaction (PCR) analysis revealed the presence of the genome of HPV type 16 (HPV 16) in 17 tumors (47%) and that of HPV type 18 (HPV 18) in 2 tumors (6%), while 17 tumors (47%) were negative for both types. Of the 17 HPV 16-positive patients, 15 metastatic lymph nodes were also positive and 2 were negative. In 2 patients positive for HPV 18, the metastatic sites were negative. All the 17 patients negative for HPV in the primary tumors were also negative for HPV 16 and HPV 18 in the metastatic lymph nodes. These data confirmed the positive correlation of HPV DNA status between primary and metastatic tumors. However, the discrepancy in 11% of cases was attributed to presence of heterogeneous clones in the primary tumor.

Adult↗