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Biomedical subjects

S Takagi

Publications and source records attributed to S Takagi.

At least 289 records · Page 16Linked to original sources
PubMed1995

[Endoscopic mucosal resection of the stomach using a ligating device (EMRL)--experimental study for the purpose of establishing reliable and safe technique].

We confirmed a new reliable and safe technique for endoscopic mucosal resection of the stomach using a ligating device (EMRL), which was used for endoscopic ligation of esophageal varices. We resected the gastric mucosa by this procedure in 6 mongrel dogs, and examined resected specimens histopathologically. It is concluded that EMRL can take a mucosal specimen 15 x 12mm in size on the average, be performed almost all the site which was previously difficult to resect endoscopically, and the submucosal local injection of physiological saline solution is necessary to perform EMRL. Based on these conclusion, we experimented to establish the safe and reliable technique of the divided mucosal resection, too. EMRL procedure is an easy and valuable treatment modality.

Adenoma↗
PubMed1995

The pathophysiological roles of heterogeneous eosinophils in allergic rhinitis caused by house dust mites.

We examined the biological characteristics of normodense and hypodense eosinophils prepared from the peripheral blood of the patients with allergic rhinitis caused by house dust mites by measuring leukotriene C4 (LTC4), platelet-activating factor (PAF), and superoxide anions. The normodense (density: 1.100-1.095) and the hypodense (density: 1.080-1.070) eosinophils were prepared by a Percoll density gradient. The normodense eosinophils produced a greater amount of LTC4 (15 ng/10(6) cells) after stimulation by calcium ionophore A23187 than the hypodense eosinophils (1.8 ng/10(6) cells). On the other hand, in the hypodense eosinophils higher amounts of both PAF (5210 pg/10(7) cells/15 min) and superoxide anions (0.33 nmoles/10(7) cells/min) were produced by calcium ionophore A23187 than in the normodense eosinophils, 501 pg/10(7) cells/15 min and 0.18 nmoles/10(7) cells/min, respectively. Considering these results, it is suggested that the two eosinophil subpopulations have distinct biological roles in generating these inflammatory mediators which appear as typical pathological features of allergic rhinitis.

Allergens↗
PubMed1995

[Absorption, distribution, metabolism and excretion of T-3761, a new quinolone derivative, in experimental animals].

We studied the absorption, distribution, metabolism and excretion of T-3761, a new quinolone derivative, in experimental animals. The following results were obtained. 1. The peak serum levels of T-3761 after a single oral administration to various fasting animals at a dose of 5 mg/kg were high in the order of rats, dogs, mice and rabbits, showing favorable absorption in all animals except for rabbits. In mice and rats, T-3761 showed higher peak serum levels than ofloxacin and ciprofloxacin but T-3761 were more rapidly eliminated from serum than ofloxacin and ciprofloxacin. 2. Tissue concentrations of T-3761 in rats were similar to those of ofloxacin but its ratio of tissue to serum levels were lower than those of ofloxacin. 3. Urinary excretion of T-3761 as active form until 24 hours after oral administration was 27.3%, 63.1%, 41.0% and 63.3% in mice, rats, rabbits and dogs, respectively. Only unchanged T-3761 was detected as active form in urine of all animals tested. In rats, urinary concentrations until 2 hours after administration were higher than those of ofloxacin. 4. Biliary excretion of T-3761 in mice and rats were 2.9% and 1.4% as active form. 5. The absorption of T-3761 was not different in male and female rats or 8 and 14 weeks old rats. The meal lowered absorption of T-3761 in rats. There was no significant difference in serum levels, urinary excretion and distribution to tissues after multiple administration of T-3761 comparing with its single administration. 6. In rats with liver dysfunction induced by D-galactosamine, the serum levels and urinary excretion were slightly higher than in normal rats. On the other hands, in rats with kidney dysfunction induced by HgCl2, the serum levels were significantly higher and urinary excretion of T-3761 was significantly lower than in normal rats. Above results show that T-3761 has unique characteristics in absorption, excretion and distribution after oral administration to animals among new quinolones, i.e., T-3761 was eliminated rapidly and poorly distributed to tissues but showed superior absorption and high peak serum levels.

Administration, Oral↗
PubMed1995

Histopathological study of microspherophakia in the Weill-Marchesani syndrome.

A surgically obtained lens from a 66-year-old man with the Weill-Marchesani syndrome was examined histopathologically by light microscopy, transmission electron microscopy and scanning electron microscopy. The lens was diffusely opaque and brown. It was microspherophakic in appearance, 6.0 mm in equatorial diameter and 4.8 mm in anteroposterior diameter. The lens fibers were well preserved, and ran circularly in the cortex and elliptically in the fetal nucleus. The lens fibers had undergone hyaloid degeneration in the area from the deep cortex to the superficial portion of the adult nucleus. Hyaloid degeneration also extended from the anterior to the posterior pole and was more marked in the equator. The distribution of lens fibers suggested that microspherophakia had developed postnatally. It is surmised that later changes in the shape of the lens affected the lens fibers, inducing hyaloid degeneration.

Abnormalities, Multiple↗
PubMed1995

[A case of atypical course after balloon occlusion for high flow traumatic carotid-cavernous fistula].

We treated a patient with a high flow traumatic carotid-cavernous fistula (CCF) by transarterial balloon occlusion. A 26-year-old male sustained an injury of the head. After 2 months he was admitted to our hospital due to exophthalmos, congestion of the palpebral conjunctiva. Right common carotid angiography showed a CCF with high flow shunt. He was treated by the endovascular balloon technique. Following the operation, abducens nerve palsy, headache, vomiting and convulsion developed and disappeared gradually within one week. Post operative 123I-IMP-SPECT revealed hyperperfusion of cerebral circulation compared to preoperative one. Post operative rt-carotid angiography showed pseudoaneurysm at cavernous portion of internal carotid artery. We discussed on abducent nerve palsy, pseudoaneurysm and hyperperfusion syndrome.

Accidents, Traffic↗
PubMed1995

[Treatment of 11 cases of pulmonary arteriovenous fistula].

We have experienced a total of 11 patients operated for pulmonary arteriovernous fistula (PAVF) from 1976 to 1993 consisting of three males and eight females with the average age of 35 years. To reserve the pulmonary function, limited resections were applied for all cases (partial resection in 8, fistula excision in 2, and segmentectomy in one case). The most recent case, a 36-year-old female who had two abnormal shadows on her routine chest X-ray, was diagnosed as PAVF by pulmonary arteriogram. She was treated by fistula excision in the right S8 lesion and embolization in the left S1 + 2 lesion. Because of its unsatisfactory natural course, PAVF should be treated aggressively by surgery and/or by embolization according to the size, shape and localization.

Adolescent↗
PubMed1995

Initiation of the transgenic lacZ gene expression in medaka (Oryzias latipes) embryos.

In total, 4165 medaka (Oryzias latipes) oocytes were injected with three DNA constructs separately, and results showed that exogenous lacZ expression was transient and stage-dependent. The initiation of the transgene expression was at the mid-blastula stage for embryos derived from oocytes injected with pmiwZ, containing the long terminal repeat (LTR) of the Rous sarcoma virus, and with pCAGGS-lacZ, containing the enhancer and promoter of the immediate early gene of the human cytomegalovirus, respectively, whereas embryos derived from oocytes injected with pMoZtk, containing the LTR of the Moloney murine leukemia virus, started expression at the late-blastula stage. These reveal that the earliest onset of the exogenous lacZ gene should be by the mid-blastula stage. Therefore the mid-blastula transition phenomenon in embryogenesis known in other animal species exists in medaka embryos.

Animals↗
PubMed1995

Differential expression of two cell surface proteins, neuropilin and plexin, in Xenopus olfactory axon subclasses.

Immunohistochemistry by using monoclonal antibodies named A5 and B2, which specifically recognize cell surface proteins the neuropilin and the plexin, respectively, revealed that olfactory axons in Xenopus tadpoles were classified into several subgroups by virtue of the expression levels of these two cell surface molecules. The vomeronasal axons expressed the plexin but not the neuropilin. The plexin-positive and neuropilin-negative vomeronasal axons form a discrete fiber bundle, even after they joined with the principal olfactory axons. However, the principal olfactory axons were divided into at least two subclasses; the neuropilin-predominant axons which expressed high levels of the neuropilin and low levels of the plexin, and the plexin-predominant axons which expressed high levels of the plexin and low levels of the neuropilin. Within the olfactory nerve the pathways for these two principal olfactory axon subclasses were initially intermingled with each other, but were gradually segregated throughout their courses from the nose to the cerebrum. Eventually, the neuropilin-predominant and the plexin-predominant principal olfactory axon subclasses projected to specified glomeruli in topographically related regions within the main olfactory bulb. Neuroanatomical tracings of the olfactory projection also confirmed the gradual segregation of the pathways for the principal olfactory axons. These results allow us to speculate that both the neuropilin and the plexin are involved in axon interactions, and play roles in the organization of the precise patterns of the olfactory pathway and projection.

Animals↗
PubMed1995

[MR imaging findings of the femoral marrow in myelodysplastic syndrome].

MR imaging of the femoral marrow was performed in 30 patients with myelodysplastic syndrome (MDS), 11 cases of which evolved to acute myeloid leukemia (AML). The MRI appearance was classified into five patterns: 1) fatty marrow; 2) faint signal; 3) nodular pattern; 4) heterogeneous infiltration; and 5) diffuse infiltration. For each type of MDS, MRI patterns of the femoral marrow were evaluated and compared with those in normal subjects as well as in patients with aplastic anemia. Signal intensity alteration, a low signal on T1-weighted SE image and a high signal on STIR image, began in the proximal femoral marrow almost symmetrically in patients with MDS. The area of abnormal signal intensity tended to gradually extend towards the distal portion of the femur as the disease progressed. MRI patterns of the femoral marrow correlated with marrow cellularity, and diffuse marrow infiltration was noted in patients with a more advanced type of MDS or with severe anemia. There were limitations to making an accurate diagnosis of the MDS type on the basis of the MRI pattern. Progression of the MRI appearance in the course of MDS was thought to be a sign suggesting evolution to AML. It was difficult to differentiate hypoplastic MDS from aplastic anemia, although the nodular pattern was commonly seen in the latter disease.

Adult↗
PubMed1995

[New concepts on precancerous lesions of the stomach].

As for precancerous lesion of the stomach detail analysis of endoscopic follow-up cases and histopathological investigations brought some new informations on its carcinogenesis. In this paper recent several reports were introduced and discussed on new opinion of precancerous conditions such as adenoma, intestinal metaplasia, gastric ulcer, remnant stomach and H. pylori. Gastric adenoma was considered to be neoplastic because of high incidence of carcinoma in situ. The stomach coexisted with adenoma showed high percentage of new arising tumor in same stomach and therefore, we can say that these are thought to be high risk group for well differentiated adenocarcinoma. Concerning the relation between intestinal metaplasia and gastric cancer we have never obtained final conclusion. However, it is likely that incomplete type of intestinal metaplasia appeared to be coexistent with gastric cancer, especially intestinal type carcinoma, which was thought to be paracancerous lesions. Recent advance of molecular biology has indicated new knowledge on gastric carcinogenesis, suggestive of multistep pathways. According to their reports, genomic instanbility appeared frequently in gastric adenoma and intestinal metaplasia as well as gastric carcinoma. Gastric carcinogenesis for ulcer, remnant stomach and H. pylori was also discussed. In near future the mechanism of gastric carcinogenesis is expected to be solved from view point of genetic events.

Humans↗
PubMed1994

Autoantigen Ku protein is involved in DNA binding proteins which recognize the U5 repressive element of human T-cell leukemia virus type I long terminal repeat.

We have identified and analyzed a 27-nucleotide sequence (U5 repressive element, designated as U5RE) at the U5 region of the human T-cell leukemia virus type I (HTLV-I) long terminal repeat (LTR) which is required for HTLV-I basal transcriptional repression. The basal promoter strength of constructs that contained deletions in the U5 region of the LTR was analyzed by chloramphenicol acetyltransferase (CAT) assays following transfection of HeLa cells or Jurkat T-cells in the presence or absence of viral transactivator tax protein. We consistently observed a 2- to 5-fold increase in basal promoter activity when sequences between +277 to +306 were deleted. In vivo competition experiments suggested that the U5 DNA fragment from +269 to +295 contains a functional repressive element (U5RE). Using gel mobility shift assays, we have purified a highly enriched fraction that could specifically bind U5RE. This DNA affinity column fraction contained three major detectable proteins on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with silver staining: 110-, 80- and 70-kDa proteins. The 110-kDa protein appeared to be a novel DNA-binding protein whose characteristics are still obscure, while the 70- and 80-kDa proteins were shown to be related to the human autoantigen Ku, the Ku (p70/p80) complex, as demonstrated by amino acid sequencing and immunological analyses. As Ku is known to be involved in transcriptional regulation, the specific interaction of Ku with U5RE raises intriguing possibilities for its function in HTLV-I basal transcriptional repression.

Amino Acid Sequence↗
PubMed1994

Bulimia nervosa with and without alcoholism: a comparative study in Japan.

To characterize females with bulimia nervosa and alcoholism, this study compared the social and family backgrounds, as well as the clinical symptoms of alcoholics with bulimia and patients with bulimia only. The subjects were 22 Japanese female patients with both bulimia nervosa and alcoholism; the comparison group comprised 22 age-matched female patients with bulimia nervosa but without alcoholism. Patients with both bulimia and alcoholism had more borderline personality disorders and pathological symptoms such as stealing, suicide attempts, and liver injuries than the nonalcoholic comparison group. The subjects' average body weight was significantly less than that of the comparison group. Whereas the clinical characteristics of females with bulimia and alcoholism differ in many respects from those with bulimia only, it is suggested that alcoholic bulimia patients form a distinct clinical subgroup among patients with bulimia nervosa.

Adult↗
PubMed1994

Glucose transport and glycolytic enzyme activities in erythrocytes of two-year-old thoroughbreds undergoing training exercise.

D-Glucose transport and cytosolic enzyme activities were measured in erythrocytes from 2-year-old thoroughbreds under continuous training exercise (race horses) and compared with those from untrained horses of various ages (sires, mares and untrained 2-year-old thoroughbreds). The activities of the glucose transport and glycolytic enzymes, hexokinase and pyruvate kinase, in the race horses' erythrocytes were elevated to 2-3.5 times above those of untrained horses. There were no significant differences in plasma glucose, triglyceride or IRI concentrations between the horses in training and untrained horses. The increases in glucose transport and glycolytic enzyme activities in their erythrocytes are considered to reflect an increased metabolic activity in the race horses resulting from the training exercises.

Animals↗
PubMed1994

Space experiment using large-sized fish: in case of carp in Spacelab-J mission.

Two carp of 26 cm in size, intact and otolith-removed (LB), were flown on the Spacelab-J for 8 days in September 12-20, 1992. Light-dependent reaction to alternating direction of illumination was recorded for 10 min twice a day together with the cerebellar EEG activity, on 2 days before the launch, during the flight and for 4 days after the landing, in same fish chamber. Reproducing the video image, it was revealed that both carp were healthy during the mission, but the LB fish was almost immobilized from the 3rd test session (48 hours in flight) by tight twisting of the EEG cable. Both fish after landing tended to stay still on the bottom of the fish chamber. Findings that the body weight reduced remarkably in both fish and that nitrite and nitrate levels of the fish water were usually high, suggested that the fish metabolism might have been enhanced during the flight.

Animals↗
PubMed1994

Telescience testbed experiments for biomedical studies: fertilization potential recording of amphibian eggs using tele-manipulation under stereoscopic vision.

The telescience testbed experiments were carried out to test and investigate the tele-manipulation techniques in the intracellular potential recording of amphibian eggs. Implementation of telescience testbed was set up in the two separated laboratories of the Tsukuba Space center of NASDA, which were connected by tele-communication links. Manipulators respective for a microelectrode and a sample stage of microscope were moved by computers, of which command signals were transmitted from a computer in a remote control room. The computer in the control room was operated by an investigator (PI) who controlled the movement of each manipulator remotely. A stereoscopic vision of the microscope image were prepared by using a head mounted display (HMD) and were indispensable to the intracellular single cell recording. The fertilization potential of amphibian eggs was successfully obtained through the remote operating system.

Animals↗
PubMed1994

Behavior of a calcium phosphate cement in simulated blood plasma in vitro.

OBJECTIVES: The purpose of this study was to gain a better understanding of the integration of calcium phosphate cement (CPC) implants in biological tissue. METHODS: An in vitro continuous flow system was employed to examine the protracted behavior of disc-shaped specimens of this bioactive material under sustained physiological-like solution conditions. Weight measurement, diameteral tensile strength measurement (DTS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and powder x-ray diffraction (XRD) were used to characterize the CPC samples as a function of immersion time. RESULTS: When CPC was immersed in simulated blood plasma in which the Ca (2.5 mmol/L) and inorganic phosphate (1.0 mmol/L) levels were kept constant, both the weight and DTS of the specimens steadily increased to about 1.5 times their original values over a period of 20 wk. SEM observations showed new precipitate formations in intimate contact with the original CPC surface. FTIR and XRD analyses revealed that the precipitate was a B-type carbonate hydroxyapatite (OHAp), the type of OHAp observed in bone and dentin. On the other hand, the interior of CPC discs did not show an increase in either bulk density or OHAp content. Thus, the increases in weight and DTS are attributable to the OHAp precipitation on the CPC surface. SIGNIFICANCE: The results suggest that under in vivo conditions, CPC implants would not dissolve in physiological fluids. OHAp coatings may form on the implants, which may enhance bonding of implants to bone by mechanically strengthening the interface between them.

Biocompatible Materials↗