Biomedical subjects

T Kitagawa

Publications and source records attributed to T Kitagawa.

At least 235 records · Page 13Linked to original sources

PubMed1994

Observation of the Fe-O2 and FeIV=O stretching Raman bands for dioxygen reduction intermediates of cytochrome bo isolated from Escherichia coli.

Reaction intermediates in dioxygen reduction by the E. coli cytochrome bo-type ubiquinol oxidase were studied by time-resolved resonance Raman spectroscopy using the artificial cardiovascular system. At 0-20 microseconds following photolysis of the enzyme-CO adduct in the presence of O2, we observed the Fe-O2 stretching Raman band at 568 cm-1 which shifted to 535 cm-1 with the 18O2 derivative. These frequencies are remarkably close to those of other oxyhemoproteins including dioxygen-bound hemoglobin and aa3-type cytochrome c oxidase. In the later time range (20-40 microseconds), other oxygen-isotope-sensitive Raman bands were observed at 788 and 361 cm-1. Since the 781 cm-1 band exhibited a downshift by 37 cm-1 upon 18O2 substitution, we assigned it to the FeIV=O stretching mode. This band is considered to arise from the ferryl intermediate, but its appearance was much earlier than the corresponding intermediate of bovine cytochrome c oxidase (> 100 microseconds). The 361 cm-1 band showed the 16O/18O isotopic frequency shift of 14 cm-1 similar to the case of bovine cytochrome c oxidase reaction.

Cytochrome b Group↗

PubMed1994

Carcinogen daily dose-dependence of the biological features and development rate of hepatocellular carcinomas induced by 3'-methyl-4-dimethylaminoazobenzene in the rat.

Differences in biological features and the rate development of hepatocellular carcinomas (HCCs) induced with various daily doses of 3'-methyl-4-dimethylaminoazobenzene were investigated. Male Donryu rats at 21 days old were fed the carcinogen at concentrations ranging from 50 to 600 ppm in the diet continuously, or 600 ppm for 3 weeks followed by a dietary promoting regimen of 500 ppm phenobarbital. Large (> or = 10 mm) HCCs were monitored and the histological features and alpha-fetoprotein (AFP) production analysed. High doses of the carcinogen predominantly induced HCCs of high grade malignancy with AFP production in a short latent period whereas lower doses and the initiation-promotion protocol were primarily associated with low grade HCCs lacking AFP production and developing after long latent periods. Thus the experimental results clearly document that biological features of neoplasms, viewed as a spectrum, may markedly differ according to the daily dose of the carcinogen applied.

Animals↗

PubMed1994

"Hot spots" of chromium accumulation at bifurcations of chromate workers' bronchi.

To investigate the mechanisms underlying respiratory tract carcinogenesis in chromate workers, we measured the concentration of chromium in samples of tissues from 50 bronchial bifurcations and other bronchial tissue obtained at autopsy, or during surgical procedures, from 9 exchromate workers known to be at risk of developing lung cancer. The mean duration of exposure was 21 years and the average time between cessation of exposure and death/surgery was 15 years. The area of the tissue samples was measured by image analysis and the chromium concentration determined by neutron activation analysis. Chromium concentrations ranged from 0.04 to 39 x 10(-10) g/microns tissue thickness/mm2 and in 80% of the cases the concentrations were greater at bifurcations than in neighboring epithelial tissue. The mean concentration ratios between bifurcations and adjacent areas were 1.5 (n = 1) in the trachea, 3.0 (n = 9) in the main bronchi, 3.6 (n = 22) in lobar bronchi, and 10.9 (n = 3) in subsegmental bronchi. Our results demonstrated long-term retention of chromium in the bronchial walls of chromate workers and also that chromium concentrations were higher at airway bifurcations than elsewhere, thus providing solid evidence for a deposition "hot spot" concept.

Aged↗

PubMed1994

Alteration by transforming growth factor-beta 1 of asparagine-linked sugar chains in glucose transporter protein in Swiss 3T3 cells.

GLUT1 protein in Swiss 3T3 cells is a 55-kDa glycoprotein with an N-linked oligosaccharide chain. We previously showed that the 65-kDa GLUT1 protein with modulated glycosylation was induced by transforming growth factor-beta 1 (TGF-beta 1) in Swiss 3T3 cells. To further investigate the altered structures of these sugar chains, the membrane glycoproteins solubilized with Triton X-100 were fractionated by lectin-affinity chromatography. The 55-kDa GLUT1 in control and TGF-beta 1-treated cells showed partial binding to Datura stramonium agglutinin (DSA), whereas the 65-kDa GLUT1 exclusively bound to DSA- and wheat germ agglutinin (WGA)-agarose. The 65-kDa GLUT1 in TGF-beta 1-treated cells was sensitive to endo-beta-galactosidase, which cleaves unsubstituted polylactosamine chains. While the 55-kDa GLUT1 in control 3T3 cells was similarly digested by endo-beta-galactosidase, that in TGF-beta 1-treated cells was resistant to this enzyme. These results suggest that the N-linked oligosaccharides of GLUT1 in Swiss 3T3 cells were altered by TGF-beta 1 to forms with more branched and/or repeated polylactosamines as well as with some substitution in the polylactosamines, resulting in a larger GLUT1 molecule. These GLUT1 proteins were exclusively located at the plasma membrane and served as a glucose transporter. However, the affinity to 2-deoxyglucose was significantly increased by TGF-beta 1, associated with the altered glycosylation of GLUT1 protein.

3T3 Cells↗

PubMed1994

Proton pumping activity and visible absorption and resonance Raman spectra of a cao-type cytochrome c oxidase isolated from the thermophilic bacterium Bacillus PS3.

Cytochrome c oxidase having heme O in addition to heme C and heme A (cytochrome cao) [Sone, N., & Fujiwara, Y. (1991) FEBS Lett. 288, 154-158] was isolated from a thermophilic bacterium, Bacillus PS3, grown under slightly air-limited conditions. Cytochrome cao could oxidize yeast cytochrome c and N,N,N',N'-tetramethyl-p-phenylenediamine twice as fast as cytochrome caa3, which this organism yielded under normal growing conditions. Cytochrome cao also pumped protons upon cytochrome c oxidation in a way similar to cytochrome caa3. Binding of cyanide to cytochrome cao caused spin-state conversion of heme O at the binuclear center and seriously inhibited its physiological activity. A low Ki value (0.4 microM) for cyanide was found to be mainly due to a small "off" constant. Resonance Raman spectra of cytochrome cao bore close resemblance to those of cytochrome caa3 in both oxidized and reduced states, although the formyl stretching (vCH=O) band was absent. The Fe-histidine stretching (vFe-His) and Fe-CO stretching (vFe-CO) frequencies of cytochrome cao were very close to those seen for cytochrome caa3, but were distinct from those of hemoglobin and peroxidases, suggesting that the protein structure in the vicinity of heme O resembles that of the heme a3 moiety of cytochrome caa3.

Bacillus↗

PubMed1994

Resonance Raman spectra of the intermediates in phototransformation of large phytochrome: deprotonation of the chromophore in the bleached intermediate.

Resonance Raman (RR) scattering from type A large phytochrome of pea was measured at cryogenic as well as ambient temperatures to determine an intermediate in which deprotonation of the chromophore takes place. The RR bands of the red-absorbing (Pr) and far-red-absorbing forms (Pfr) of large pea phytochromes at ambient temperatures are almost the same in their frequencies as those of the intact form reported previously (Mizutani et al., 1991). The RR spectrum of large phytochrome excited at 364 nm at -120 degrees C, where Pr and a photointermediate, I700 (= lumi-R), are trapped, showed a strong band at 1625 cm-1 with a shoulder at 1648 cm-1 in the C C=C stretching region. The shoulder disappeared, and a new band appeared at 1597 cm-1 upon raising the temperature to -80 degrees C, where transformation from I700 to meta-Ra proceeds. The RR spectra remained unchanged until -10 degrees C, indicating that the RR spectra of meta-Rb and meta-Rc are close to that of meta-Ra, and we call them comprehensively the bleached intermediate, Ibl. At ambient temperatures where photo-steady-states among a few species are attained, strong RR bands were observed at 1625 and 1599 cm-1 upon excitation at 364 nm under simultaneous far-red illumination, and the 1599-cm-1 band was appreciably intensified under simultaneous red- instead of far-red illumination. By comparison of these spectra with those at low temperatures, the 1625- and 1599-cm-1 bands were reasonably assigned to Pr and Ibl, respectively. A chemically prepared model of the bleached form, Pbl, also gave a prominent band at 1599 cm-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Fabaceae↗

PubMed1994

Human papillomavirus DNA in adenocarcinoma and adenosquamous carcinoma of the uterine cervix detected by polymerase chain reaction (PCR).

Although human papillomaviruses (HPV) have been implicated strongly in the pathogenesis of squamous cell carcinomas of the uterine cervix, a few studies have suggested that HPV may be an etiological factor for adenocarcinoma of the cervix. To evaluate the association between HPV infection and cervical adenocarcinoma, we analyzed formalin-fixed, paraffin-embedded tissues from 64 patients with adenocarcinoma or adenosquamous carcinoma of the uterine cervix for the presence of HPV DNA using polymerase chain reaction (PCR) with primers specific for the 6, 11, 16, 18, 31, 33, and 35 types. HPV DNA was detected in 24 of 43 (56%) cases of adenocarcinoma, and in 19 of 21 (91%) cases of adenosquamous carcinoma. Fifteen of the 43 (35%) adenocarcinomas and 10 of the 21 (48%) adenosquamous carcinomas contained HPV 18 DNA, and 10 of the 43 (23%) adenocarcinomas and 11 of the 21 (52%) adenosquamous carcinomas contained HPV 16 DNA. One specimen was positive for HPV 31 and five contained HPV 35 DNA, all but one as double infections with HPV 18. No evidence of HPV 6, 11, or 33 DNA carriage was seen. These results suggest that human papillomaviruses, particularly HPV 16 and 18, play a role in the etiology of cervical adenocarcinoma and adenosquamous carcinoma.

Adenocarcinoma↗

PubMed1994

Establishment and characterization of human cell lines from a serous papillary adenocarcinoma of the endometrium.

Two cell lines, SPAC-1-L and SPAC-1-S, derived from a human serous papillary endometrial adenocarcinoma, have been established and repetitively subcultured as a monolayer culture for over 3 years through 144 passage generations. Each of the two cell lines is a subline derived from one original tumor. They have been independently subcultured from the primary culture dishes without any attempt to clone subpopulations and were further characterized with regard to morphology, growth kinetics, tumor marker production, karyotype, and tumorigenicity. These studies indicated that the SPAC-1-L and -S cell lines are different from each other in some cell properties such as morphological character, growth kinetics, and tumor marker productions. Compared with cell lines from a serous papillary endometrial carcinoma that has been previously reported in the literature, our two cell lines are more tumorigenic on nude mice (100%), which possibly correlates with the unusually aggressive biological behavior of the original tumor. In addition, implanted nude mouse tumors, especially the tumor derived from SPAC-1-S cells, retained many characteristics of the original tumor and histologically closely resembled the original serous papillary adenocarcinoma. Since serous papillary carcinoma is a clinically aggressive histological variant of endometrial adenocarcinoma with a significantly poor prognosis, these SPAC-1-L and -S cell lines should prove useful in future studies of the extremely aggressive biological behavior and unique morphology of this tumor.

Antigens, Tumor-Associated, Carbohydrate↗

PubMed1994

Successful in vitro fertilization and pregnancy by micromanipulation with epididymal sperm.

PURPOSE: To examine the effectiveness of micromanipulation on the treatment of the patients with obstructive azoospermia, subzonal insemination or partial zona dissection was performed using epididymal sperm of the 23 patients, and the in vitro fertilization and embryo transfer (IVF-ET) outcomes were analyzed. RESULTS: Fertilized oocytes were obtained in 11 cycles of the 25 treated cycles, and six pregnancies were established by the subsequent ET. Through the analysis of 13 cycles in which both the micromanipulation and usual IVF insemination were performed, the fertilization rate per oocyte with the micromanipulation [25% (28/113)] was significantly higher than that with the usual insemination method [4% (4/102)]. The micromanipulation was most useful for the treatment of the patients with congenital absence of the vas deferens. Moreover, there was no need to aspirate a large volume of the epididymal fluid, but it was essential to prepare more than 10 mature oocytes retrieved. CONCLUSIONS: These results indicate that micromanipulation with epididymal sperm is an effective treatment for obstructive azoospermia, and careful preparations of sperm and well-controlled ovarian hyperstimulation are necessary for successful IVF-ET.

Adult↗

PubMed1994

ICA and organ-specific autoantibodies among Japanese patients with early-onset insulin-dependent diabetes mellitus--the JDS study.

The Japan Diabetes Society (JDS) conducted a multicenter study on the immunogenetics of insulin-dependent diabetes mellitus (IDDM) among Japanese. The previous report of the JDS study described HLA types and other immunogenetic markers in Japanese patients with IDDM. In the present report, the autoimmunity of Japanese patients was studied by measuring ICA and other organ-specific autoantibodies in patients with different durations of IDDM. The prevalences of ICA were the highest in the first year after diagnosis (73.1%) and decreased to 58.0%, 18.3% and 2.8% in 1-5 years, 5-10 years and 10 years or more after diagnosis, respectively (P < 0.01), while the prevalences of the other organ specific autoantibodies increased gradually with duration of IDDM from 20% in the first year to 35% in 10 years or more after diagnosis (P < 0.05). There were no sex differences in the prevalences of ICA but those of other organ-specific autoantibodies were significantly higher in female patients than in male patients (P < 0.01). The prevalence of ICA was not correlated with sex, age at onset or HLA types. In one of the subjects, a girl, the titers of ICA increased in parallel with a decrease in insulin secretion before the development of overt IDDM and declined thereafter. These findings suggest that IDDM might develop when the autoimmunity specific to pancreatic islets is triggered in people with underlying autoimmunity as shown by the presence of organ-specific autoantibodies other than ICA.

Adolescent↗

PubMed1994

Epidemiology of type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetes mellitus in Japanese children.

The overall annual IDDM incidence rates by area in Japan for 1985-1989 for children 0-14 years of age at diagnosis were from 1.65 to 2.07 per 100,000. The incidence in males and females did not show any temporal trends during the period between 1980 and 1989. The prevalence of IDDM was about 1 per 10,000. The clinical features at diagnosis among Japanese IDDM children identified during the 2-year period between 1979 and 1980 were as follows. Fourteen percent of the cases were in coma and 12% of the cases were asymptomatic at diagnosis. There is a suggestion that slow onset IDDM is often seen in Japan. In these children, the decline of serum CPR levels and the prevalence of ICA (islet cell antibodies) over the course of diabetes was slower than in those with an abrupt onset classical IDDM. During the period from 1975 through 1990 the incidence rates of NIDDM in school children showed as much as an approximate 1.5-fold increase along with a similar increase in the prevalence of obesity. About eighty percent of these NIDDM children were obese. A predominance of female children developing diabetes was seen in both type of diabetes, IDDM and NIDDM, in Japan. Non-obese type NIDDM in children was more common in females than in males. It is interesting to note that the mean height of Japanese children with IDDM was not different from the national average, but children with NIDDM were significantly taller than the national average.

Adolescent↗

PubMed1994

The distal residue-CO interaction in carbonmonoxy myoglobins: a molecular dynamics study of two distal histidine tautomers.

Four independent 90 ps molecular dynamics simulations of sperm-whale wild-type carbonmonoxy myoglobin (MbCO) have been calculated using a new AMBER force field for the haem prosthetic group. Two trajectories have the distal 64N delta nitrogen protonated, and two have the 64N epsilon nitrogen protonated; all water molecules within 16 A of the carbonyl O are included. In three trajectories, the distal residue remains part of the haem pocket, with the protonated distal nitrogen pointing into the active site. This is in contrast with the neutron diffraction crystal structure, but is consistent with the solution phase CO stretching frequencies (upsilon CO) of MbCO and various of its mutants. There are significant differences in the "closed" pocket structures found for each tautomer: the 64N epsilon H trajectories both show stable distal-CO interactions, whereas the 64N delta H tautomer) has a weaker interaction resulting in a more mobile distal side chain. One trajectory (a 64N delta H tautomer) has the distal histidine moving out into the "solvent", leaving the pocket in an "open" structure, with a large unhindered entrance to the active site. These trajectories suggest that the three upsilon CO frequencies observed for wild-type MbCO in solution, rather than representing significantly different Fe-C-O geometries as such, arise from three different haem pocket structures, each with different electric fields at the ligand. Each pocket structure corresponds to a different distal histidine conformer: the A3 band to the 64N epsilon H tautomer, the A1,2 band to the 64N delta H tautomer, and the A0 band to the absence of any significant interaction with the distal side chain.

Animals↗

PubMed1994

Characteristics of chromate workers' cancers, chromium lung deposition and precancerous bronchial lesions: an autopsy study.

The characteristics of lung cancers induced by inhaled chromate were studied in 13 consecutive autopsies on male ex-chromate workers. In addition to histopathology, we examined: (1) the relationship between the occurrence of lung cancer and the amount of chromium (Cr) deposited in the lung as determined by atomic absorptiometry and (2) the chronological changes in five precancerous lung lesions followed by bronchoscopy till death. Twenty-one cancers were identified, including 16 lung tumours observed either during follow-up or at autopsy. Of these 16 tumours, 13 were found in six subjects, implying a high frequency of multiple cancers. Eleven (69%) out of the 16 tumours were of squamous cell type (including carcinoma in situ), this being twice as frequent as in age-matched controls. A further characteristic was predominance in the central part of lung (69%). The lung Cr burden was very much higher [40-15,800 micrograms g-1 (dry)] in patients with lung tumours than in those without (8-28 micrograms g-1). Five of the precancerous lesions followed by bronchoscopy originated at bronchial bifurcations. Four of these cases showed a return to normal histology at autopsy even without therapy, and the other did not progress.

Aged↗

PubMed1994

Frequency of atypical mitosis in intestinal metaplasia of the gastric mucosa in Japanese patients.

The morphologic characteristics of the mitotic figures present in intestinal metaplasia (IM) of the gastric mucosa were investigated in 70 consecutive gastrectomy specimens from Japanese nationals. The specimens contained, in addition, early gastric cancer of intestinal type (n = 44) or of diffuse type (n = 22). The remaining 4 were recorded as mixed. One hundred or more consecutive mitoses/specimens were studied by high-power microscopy in hematoxylin and eosin-stained preparations (at x1000). A total of 7259 mitoses were recorded (mean 103.7 mitoses/case). Of these, 1089 mitoses (i.e. 19.1%) were considered as atypical according to a previous classification. The percentage of atypical mitoses was found to be unrelated to the gender, to the increasing age of the patients, to the histologic type of the adenocarcinoma contained in the specimens, or to the anatomic site (e.g. corpus or antrum or tumor proximity). Comparative studies were done with gastrectomy specimens from Swedish nationals (a population with a 4-times-lower incidence of gastric carcinoma than the Japanese). The results showed a much lower frequency of mitotic figures/specimen and only occasional atypical mitosis. Since atypical mitosis has so far been reported only for neoplastic lesions in the gastrointestinal tract, it is suggested that IM with atypical mitosis may be a genuine precancerous lesion in the gastric mucosa in Japanese subjects.

Adult↗

PubMed1994

Incidence of second primary cancers in Osaka residents, Japan, with special reference to cumulative and relative risks.

This study was conducted to examine the incidence rates and cumulative risks of second primary cancers in Osaka and to compare the observed number of second primary cancers with the expected number calculated using cancer incidence rates among Osaka residents. Study subjects were all reported cases aged 0-79 who were first diagnosed as having a first primary cancer between 1966-86. Incidence of second primary cancer among the study subjects was examined through to the end of 1989. The total number of study subjects was 217,307. During the follow-up period (mean duration: 3.7 years), second primary cancers developed in 5,071 patients (2.3%). Incidence of synchronous (interval < 3 months) and metachronous (interval > or = 3 months) second primary cancers increased in the later years. Incidence rates of second primary cancers were significantly associated with gender (male), age and calendar year at diagnosis of the first cancer. Based on the incidence rates, cumulative risk of developing metachronous second primary cancer was calculated. The ten-year cumulative risk was estimated as 10% for those who developed their first cancer during their sixties in 1978-83. The observed number of second primary cancers (including synchronous) was compared with the expected number. The ratios of observed-to-expected numbers were generally lower than 1.0 among those who developed their first cancer in 1966-77, while these ratios were higher than 1.0 among those who developed their first cancer in 1978-86. The ratios were much higher than 1.0 among those who developed their first cancer in their childhood and youth. Patients who had developed cancer of the colon, larynx, lung, bladder, or breast (female) showed significantly higher risk of developing second primary cancer during the period 1-4 years after diagnosis of the first cancer.

Adult↗

PubMed1994

Subcutaneous sarcomas of probable neuronal origin in a transgenic mouse strain containing an albumin promoter-fused simian virus 40 large T antigen gene.

Frequent development of subcutaneous neurogenic sarcomas was observed in a hepatocellular carcinoma-producing transgenic mouse strain harboring an albumin-promoted simian virus 40 (SV40) large T antigen gene. Found unexpectedly in 19 out of 306 mice (6.2%) by 6 months of age, all the sarcomas were similar and were characterized as neurogenic on the basis of histological features including Homer-Wright type rosette formation, the presence of dense core granules of 100-200 nm diameter under the electron microscope, expression of neuron specific enolase, S-100 protein, and catecholamines, and nerve cell-like differentiation in culture in response to But2cAMP. Immunohistochemical study revealed tiny clusters of SV40 T antigen-expressing cells with neurogenic character in normal-appearing adult mouse subcutis as candidate progenitors of the sarcomas. The tumor cells strongly expressed large T antigen but did not express albumin or albumin mRNA at the detection sensitivity used. Transient transfection assay (CAT assay), however, revealed the presence of transcriptional factor(s) acting on the albumin promoter in tumor cells. Thus, the present investigation suggested the presence of specifically differentiated neurogenic cells in the mouse subcutis with aberrant expression of the transgene.

Albumins↗

PubMed1994

Development of an effective and simple insemination method for the in vitro fertilization of patients with male-factor infertility.

An insemination method involving mechanical removal of the cumulus and multiple oocytes per dish (MRC-MOPD) was applied to achieve in vitro fertilization (IVF) of patients with male-factor infertility, and the prognosis of IVF and embryo transfer was evaluated. Although the fertilization rate of patients with male-factor infertility was only 41.4% (12/29) using standard insemination methods, a 73.0% (27/37) fertilization rate was achieved with the MRC-MOPD method. Moreover, 10 patients with male-factor infertility who were treated with the MRC-COPD method achieved clinical pregnancy. A comparison of the results in the 10 patients who were treated with both methods in common reveals that the MRC-MOPD method also increased the fertilization rate per oocyte. The rate of occurrence of polyploid fertilization did not increase, although large numbers of sperm were inseminated via the MRC-MOPD method. These results indicate that the MRC-MOPD method is an effective and simple insemination technique to achieve successful IVF of patients with male-factor infertility.

Embryo Transfer↗

PubMed1994

Analysis of flow in a two-dimensional collapsible channel using universal "tube" law.

This paper presents an extension of the previous analyses on the collapsible tube-flow problem using a simplified model based on a two-dimensional channel conveying a one-dimensional flow. The main objective of the paper is to exploit the static and dynamic behavior of the model, by comparing with available experimental data and examining the accuracy of calculated results obtained for different numerical resolutions. The main revision from the previous analyses is the incorporation of a universal "tube" law that is valid for a wide range of positive and negative transmural pressure. Most of the numerical results agree qualitatively with the experimental observations. Self-excited high-frequency oscillation with very small amplitude of the membrane wall is however, predicted to occur in a flow range where the slope of the pressure drop curve is positive. It is seen that the high-frequency oscillation is associated with the motion of the separation point of the flow.

Compliance↗