Biomedical subjects

K Takada

Publications and source records attributed to K Takada.

At least 1,027 records · Page 57Linked to original sources

PubMedDate not supplied

Carcinogenicity study of beta-cyclodextrin in F344 rats.

The carcinogenicity of beta-cyclodextrin, a cyclic, water-soluble carbohydrate comprising seven glucose units, was examined in Fischer 344 (F344) rats. Groups of 50 males and 50 females were given the compound in their diet at concentrations of 0 (control), 2.5 or 5% for 104 wk. Surviving rats were then given a basal diet for a further 5 wk and killed at 109 wk. The dose levels were selected from the results of a 13-wk subchronic toxicity study. Dose-dependent inhibitory effects of beta-cyclodextrin on growth were observed in both sexes of the treated groups. The survival rates, mean survival times and range, however, demonstrated no significant differences between the control and treated groups. A variety of tumours developed in all groups, including the control group, but all the neoplastic lesions were histologically similar to those known to occur spontaneously in this strain of rat, and no statistically significant increase in the incidence of any tumour was found for either sex of the treated groups. Thus, it is concluded that under the present experimental conditions, the high dose, about 340-400 times higher than the current daily human intake from ingestion as a food additive and from pharmaceutical use, does not have any carcinogenic potential in F344 rats.

Administration, Oral↗

PubMedDate not supplied

Gastric scirrhous carcinoma as a rare cause of aggressive fibromatosis in the neck.

Aggressive fibromatosis is characterized by locally aggressive proliferation of fibroblasts and occasionally occurs in the head and neck. Although the etiology of this disease is still controversial, recent studies have shown that high levels of growth factors are found in these lesions. This article reports a case of 51-year-old woman with aggressive fibromatosis in the neck and inguinal region bilaterally. Gastric fiberscopic examination revealed a complication of advanced gastric scirrhous carcinoma. There were remarkably high levels of basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) in the serum. Postmortem autopsy examination was performed and scattered gastric carcinoma cells were observed in the fibromatosis lesions. Immunohistological staining showed positive expression of bFGF in the fibromatoses and stomach. We concluded that this was a rare case in which bFGF and PDGF released from gastric carcinoma cells caused aggressive fibromatosis by promoting unregulated proliferation of fibroblasts and collagen production locally.

Adenocarcinoma, Scirrhous↗

PubMedDate not supplied

Salivary production rates fall with age in subjects having anti-centromere, anti-Ro, and/or anti-La antibodies.

OBJECTIVES: To clarify the relationship between a subject's sicca-associated autoantibodies type and changes in salivary production rate (SPR) with age in subjects having any of these antibodies. METHODS: One hundred and eighty-five subjects (female:male = 178:7), who had at least one of the three autoantibodies, anti-centromere (ACA), anti-Ro (SSA), and/or anti-La (SSB), and 65 healthy females were enrolled. The Saxon test was used to measure SPR. RESULTS: SPRs in the seven male subjects were significantly higher than those in the 178 females tested. Therefore, only female subjects were used for the following analyses. Subjects were classified into substantially four groups according to their seropositivities for ACA, anti-Ro, and/or anti-La: group A, subjects having ACA alone; group B, subjects having anti-Ro alone; group E, subjects having anti-Ro and anti-La; group DFG, subjects having ACA with anti-Ro and/or anti-La. The frequency of Sjögren's syndrome (SS) was 74.0-94.1% in these groups. SPR did not decrease with age in normal female controls. By contrast, SPR decreased significantly with age in the groups having sicca-associated antibodies. The degree of SPR decrease compared between groups was: group A group [symbol: see text] B > group E [symbol: see text] group DFG. In the analysis of the subgroup having any of the sicca-associated antibodies but not fulfilling the classification criteria of SS, SPR also decreased with age. CONCLUSION: SPR in subjects having any of the sicca-associated antibodies (ACA, anti-Ro, or anti-La) decreased with age.

Aging↗

PubMedDate not supplied

Study on human spermatozoal motility: preliminary report on newly developed multiple exposure photography method.

We have developed a multiple exposure photography (MEP) method for objectively evaluating the spermatozoal motility. The semen specimen placed in a 10-microns chamber was photographed through the phase-contrast microscope. Light pulses were generated with the aid of a multipulser using a xenon stroboscope (pulse interval: 160 msec., exposure: 1 sec.). In the photomicrographs, motile spermatozoa produced images of six-ringed chains, while nonmotile spermatozoa appeared as brighter images which clearly visualized spermatozoa from the head to the tail. When 30 semen specimens from fertile males were analyzed 1 hour after their collection, the mean spermatozoal concentration was found to be 79 x 10(6) per ml the mean rate of motile spermatozoa 39.7% and the mean spermatozoal velocity 29.3 microns per sec. The rate of motile spermatozoa estimated by the MEP method (39.7%) was lower than that estimated by the direct observation method (60% or more) by ca. 20%. The MEP method enables concurrent accurate estimation of the spermatozoal concentration, the rate of motile spermatozoa and the velocity of individual spermatozoa.

Humans↗

PubMedDate not supplied

Anticaries effect of a component from shiitake (an edible mushroom).

The caries-inhibiting effect of the extract from shiitake (Lentinus edodes), the most popular edible mushroom in Japan, was studied both in vitro and in vivo. Shiitake extract showed an inhibitory effect on water-insoluble glucan formation from sucrose by crude glucosyltransferases of Streptococcus mutans JC-2 and Streptococcus sobrinus OMZ-176. The firmly adherent plaque in the artificial plaque formation test was strongly inhibited by shiitake extract. The reduction of firmly adherent plaque caused an increase in the incidence of non- and loosely adherent plaque and a decrease in total plaque formation. A significantly lower caries score was observed in specific pathogen-free rats infected with S. mutans JC-2 and fed with a cariogenic diet containing 0.25% shiitake extract as compared with controls fed the cariogenic diet without shiitake extract.

Animals↗

PubMedDate not supplied

Susceptibility of Streptococcus mutans and Streptococcus sobrinus to cell wall inhibitors and development of a novel selective medium for S. sobrinus.

Representative strains of Streptococcus mutans and Streptococcus sobrinus showed differences in susceptibility to members of the monobactam group of beta-lactam antibiotics: S. sobrinus was less sensitive than S. mutans. The minimum inhibitory concentrations of aztreonam (AZT) and carumonam, both of which belong to this group, were 2,000 microg/ml for S. sobrinus and 125 microg/ml for S. mutans. Further addition of fosfomycin, bacitracin and sodium chloride to Mitis Salivarius agar (MS) supplemented with AZT resulted in growth inhibition of S. mutans and oral streptococci other than S. sobrinus, and was therefore used as a selective medium for S. sobrinus (MS-SOB medium). The average growth recovery of laboratory and clinically isolated strains of S. sobrinus on MS-SOB medium was 74.1% compared to that on MS medium. Seventy-eight percent of clinical samples in which S. sobrinus was detected yielded pure growth of S. sobrinus on MS-SOB medium.

Anti-Bacterial Agents↗

PubMedDate not supplied

A new selective medium for Streptococcus mutans and the distribution of S. mutans and S. sobrinus and their serotypes in dental plaque.

A new selective medium (MS-MUT) was developed for the isolation of Streptococcus mutans from clinical specimens. The average growth recovery of S. mutans on MS-MUT medium was 72.4% of that on MS medium. Growth of Streptococcus sobrinus was significantly inhibited on the medium with an average recovery of 0.034%. In 103 subjects, S. MUTANS was detected at 58.3, 75.0 and 95.7% in the dental plaque of caries-free (CF), caries-inactive (CI) and caries-active (CA) subjects, respectively. S. sobrinus was detected in 8.3, 13.6 and 38.3% of CF, CI and CA subjects, respectively. S. sobrinus alone was detected in only 4.3% of CA subjects. The subjects in whom neither S. mutans nor S. sobrinus were detected were 41.6% in CF and 25.0% in CI. The most predominant serotype was C with a 67% detection rate. S. sobrinus, serotypes D or G were usually found together with S. mutans.

Adolescent↗

PubMedDate not supplied

Liver tumor-promoting effect of beta-naphthoflavone, a strong CYP 1A1/2 inducer, and the relationship between CYP 1A1/2 induction and Cx32 decrease in its hepatocarcinogenesis in the rat.

Interrelationships among induction of cytochrome P-450 (CYP) 1A1/2, decrease in connexin 32 (Cx32), and liver tumor-promoting activity by beta-naphthoflavone (BNF) in the promotion stage were examined in a 2-stage liver carcinogenesis model. A total of 20 male Fischer 344 rats were initiated with a single intraperitoneal injection of 150 mg/kg of diethylnitrosamine (DEN) or were given the saline vehicle alone. Starting 2 weeks later, they were fed a diet containing 2%, 1%, or 0% BNF for 6 weeks. All animals were subjected to a two-thirds partial hepatectomy at week 3 and were sacrificed at week 8. Absolute and relative liver weights were significantly increased in the DEN+BNF groups as compared to the DEN-alone group. Diffuse hepatocellular hypertrophy with cytoplasmic eosinophilia, sometimes accompanied by development of adenoma-like hepatic foci, was observed in the BNF-treated rats. Remarkable induction of cytochrome CYP 1A1/2 and significant increase in CYP 2E1 were noted in the DEN+BNF groups, and positive immunohistochemical staining for both was observed diffusely. The areas of Cx32-positive spots per hepatocyte in the centrilobular areas of livers of the BNF-treated rats were significantly decreased, but no changes were observed in periportal areas. The numbers and areas of foci positive for glutathione S-transferase placental form were increased in the BNF-treated groups. These results suggest that BNF is a liver tumor promoter that, unlike phenobarbital, does not induce CYP 2B1/2 isozymes, and there seems to be no direct relationship between CYP 1A1/2 induction and Cx32 reduction in BNF hepatocarcinogenesis.

Animals↗

PubMedDate not supplied

A spontaneous seminal vesicle adenocarcinoma in an aged F344 rat.

A rare seminal vesicle adenocarcinoma was found in a 109-wk-old Fischer 344 (F344) rat. At necropsy, the right seminal vesicle was enlarged, containing a 15- x 18- x 18-mm mass. The neoplasm occupied almost the entire seminal vesicle lumen and consisted of epithelial cells arranged in papillary, glandular, and solid patterns. Tumor cells were larger than their normal counterparts in the seminal vesicles and had round nuclei and abundant cytoplasm. Clusters of macrophagelike cells with less abundant cytoplasm and indented nuclei were apparent in the lumina of the glandular structures formed by the tumor cells. No metastasis to other tissues or organs was observed. Immunohistochemically, tumor cells were positive for keratin and S-100, and the macrophagelike cells bound antibodies against vimentin and ED-1. Ultrastructurally, the tumor cells exhibited many small secretory granules, some microvilli, and intercellular junctions. The macrophagelike cells, in contrast, were characterized by lysosomes and abundant rough endoplasmic reticulum. Therefore, a diagnosis of seminal vesicle adenocarcinoma with intraluminal macrophage infiltration was made. This is the first case report of such a seminal vesicle tumor in an F344 rat.

Adenocarcinoma↗

PubMedDate not supplied

Protective effects of Hange-shashin-to on water-immersion restraint stress-induced gastric ulcers.

Hange-shashin-to (HST) is a traditional Chinese herbal prescription (Banxia Xiexin Tang) which has long been used in the therapy of gastric functional disorders. In this report, the effect of HST extract on water-immersion restraint stress-induced gastric ulcer based on the changes in gastric mucin content and the variations of monoamine contents in hypothalamus were investigated. Ulcer index was microscopically measured by the sum total of the lengths of ulcers in glandular stomach. Gastric mucin content was determined by a PAS-staining methods and the monoamine contents were detected by HPLC-ECD method. HST extract was orally administered at 1, 2 and 3 g/kg for three consecutive days before stress exposure. Water-immersion restraint stress decreased the mucin content and produced gastric ulcers in a restraint time-dependent manner. Pretreatment with HST extract markedly inhibited the reduction of gastric mucin content and the development of gastric ulcer with significant differences (p < or = 0.01). The remarkable decrease of NE and 5-HT contents but prominent increases of MHPG and 5-HIAA contents were observed in hypothalamus after water-immersion restraint stress (p < or = 0.01). Those changes in monoamine contests in hypothalamus were also significantly inhibited by the pretreatment with HST extract at higher dosage (p < or = 0.05). These results indicate that the changes in gastric mucin content and the variation of monoamines in hypothalamus relate to the pathogenesis of water-immersion restraint stress-induced gastric ulcers, and it is suggested that the prophylactic effects of HST extract on stress induced gastric ulcers may be associated with an increase in gastric mucin content, although the prevention of HST extract on the extraordinary changes in monoamine contents in hypothalamus due to stress cannot be ruled out.

Animals↗

PubMedDate not supplied

Peripheral nerve involvement in HTLV-I-associated myelopathy: report of a case.

A patient came to our clinic suffering from mild sensory loss, exaggeration in knee reflexes, bilateral extensor plantar responses and elevation of the antibody level to the human T-lymphotropic virus type I (HTLV-I). Electrophysiological and pathological studies showed axonal and demyelinating neuropathy. The condition appeared to be a slowly progressive myeloneuropathy. HTLV-I may play an important role in the pathogenesis of myeloneuropathy.

Female↗

PubMedDate not supplied

Discrepancy between antiplatelet antibody activities detected by immunoblot procedure and platelet counts in idiopathic thrombocytopenic purpura.

By immunoblot procedure it is possible to identify the pathogenic autoantibody responsible for platelet destruction in idiopathic thrombocytopenic purpura (ITP). We assessed the relationship between antiplatelet antibody activities detected by this technique and clinical thrombocytopenia in a patient with ITP whose antiplatelet autoantibody was directed toward an 85-kDa antigen. In this patient, over a 2-year-period, the platelet counts were not correlated with the levels of antiplatelet autoantibody detected by immunoblotting. The present observations suggest that IgG autoantibody directed toward a specific antigen is not necessarily a critical determinant of the degree of thrombocytopenia, and that factors other than IgG-Fc-receptor-mediated platelet destruction are also important in the determination of the disease activity in ITP.

Adult↗

PubMedDate not supplied

Report of a case of Crohn's disease associated with hyper-creatine phosphokinase-emia.

A young male patient with myositis associated with Crohn's disease is reported. His serum creatine phosphokinase (CPK) level was markedly elevated, but he had no muscle symptoms. The serum CPK level was not correlated with the activity of Crohn's disease. Muscle biopsy showed myositis with only degeneration of the muscle fibers and infiltration of inflammatory cells. The etiology of myositis in this case was not clear. Diagnosis of myositis based on a muscle biopsy in patients with Crohn's disease showing an elevated serum CPK level without any discernible cause has not been reported previously. Careful attention to the serum CPK and muscle symptoms in patients with Crohn's disease is suggested.

Adult↗

PubMedDate not supplied

[Disappearance of essential tremor after thalamic infarction].

Stereotactic thalamotomy has been used with some benefit in the treatment of essential tremor. We report a 73-year-old woman whose essential tremor of the right hand spontaneously disappeared after thalamic infarction. She had suffered hand tremor of the right hand for seven years. One morning, she noticed mild muscular weakness in her right upper and lower extremities, numbness around her mouth and paresthesia in her right arm. Simultaneously, she noticed disappearance of the tremor of her right hand. Several days later, right hemiplegia and paresthesia completely resolved. Neurological examination revealed no postural tremor or resting tremor. T 2-weighted brain MR imaging showed a high-intensity signal in the left thalamus that involved the ventralis intermedius nucleus. Clinical recovery from the effect of the infarct on essential tremor was complete. Therefore, it seems that thalamic infarction in this patient had an effect on essential tremor similar to that achieved with thalamotomy.

Aged↗

PubMedDate not supplied

Expression of CSF-1 receptor on TRAP-positive multinuclear cells around the erupting molars in rats.

Bone resorption overlying a developing tooth is a necessary event in the creation of an eruption pathway. The formation and function of osteoclasts, which play a major role in bone resorption, are controlled by several factors. Although CSF-1 and its mRNA are expressed in dental follicle cells required for eruption, little is known about the contribution of CSF-1 to osteoclast formation on the bony crypt around the tooth germ. The receptor protein of the CSF-1 encoded proto-oncogene c-fms was identified on multinucleated cells adjacent to the dental follicle, in conjunction with TRAP staining as a marker enzyme for osteoclasts in rat. c-Fms was highly expressed in TRAP-positive multinuclear cells at 3 days postnatal and the number of c-Fms-expressing cells was reduced thereafter. Administration of IL-1alpha, which enhances formation and function of osteoclasts, caused an increase in the number of c-Fms and TRAP-positive cells in rat. On the contrary, injection of calcitonin, which depresses osteoclast formation, caused a decrease in the number. It is obvious that the receptor of CSF-1 is expressed on the surface of osteoclasts around the tooth germ, on the dental follicle. These findings suggested that CSF-1 directly enhances the influx of osteoclasts adjacent to the erupting tooth, resulting in the formation of an eruption pathway.

Acid Phosphatase↗

PubMedDate not supplied

Combination of preoperative embolization of the right portal vein and hepatic artery prior to major hepatectomy in high-risk patients: a preliminary report.

BACKGROUND/AIMS: Preoperative transhepatic portal vein embolization may not always be sufficient to achieve the desired changes in contralateral hepatic volume and function. The beneficial role of additional transcatheter arterial embolization performed after inadequate response to preoperative transhepatic portal vein embolization is described. METHODOLOGY: Four patients underwent both preoperative transhepatic portal vein embolization and transcatheter arterial embolization, and 6 control patients underwent preoperative transhepatic portal vein embolization only. Changes in right liver lobe volume fraction, residual left lobe volume fraction, and prediction score (low-risk, < 45; borderline, 45-55; high-risk > 55); were evaluated. RESULTS: 1) The change in right liver lobe volume after both preoperative transhepatic portal vein embolization and transcatheter arterial embolization (volume after/before) was 0.75 times that of the original level whereas after preoperative transhepatic portal vein embolization, they were only 0.81 times that of the original level. 2) The change in residual left liver volume after both preoperative transhepatic portal vein embolization and transcatheter arterial embolization (volume after/before) was 1.40 times that of the original level whereas after preoperative transhepatic portal vein embolization they were only 1.30 times than the original level. The changes in left liver volume after preoperative transhepatic portal vein embolization/transcatheter arterial embolization was more favorable than those after preoperative transhepatic portal vein embolization only. 3) The change in prediction score after both preoperative transhepatic portal vein embolization and transcatheter arterial embolization (after/before) was 0.81 times that of the original level. All prediction score in high-risk patients recovered to the borderline or safety zone. Change after preoperative transhepatic portal vein embolization only (before/after) was 0.87 times that of the original level. 4) All 4 patients who underwent both preoperative transhepatic portal vein embolization and transcatheter arterial embolization received right hepatic lobectomy successfully and returned to their normal life style. CONCLUSIONS: Preoperative occlusion of right hepatic inflow vessels increased the volume and function of the contralateral lobe where high-risk patients recovered to the borderline zone for major hepatic resection.

Aged↗

PubMedDate not supplied

Effects of inspired oxygen concentration on peripheral microcirculation studied by the rabbit ear chamber method.

The effects of oxygen inhalation on peripheral hemodynamics were studied in vivo. We observed changes in the cutaneous microcirculation in the rabbit under various inspiratory oxygen concentrations. Blood vessel diameter, blood-flow velocity and blood-flow rate were gradually reduced as oxygen concentrations were increased from 30%. These results indicate that inspiration of more than 30% oxygen causes deterioration of the microcirculation.

Administration, Inhalation↗

PubMedDate not supplied

Automatic detection and measurement of EMG silent periods in masticatory muscles during chewing in man.

Silent periods are transient stops of muscle activity that are induced by mechanical or electrical stimulus. The current report describes a new algorithm which enables automatic detection and measurement of silent periods that occur in the EMG of human masticatory muscles during chewing efforts together with jaw positions in space at the occurrence of the silent periods. The EMG signal for detection of the silent period is modeled based on the observation of the EMG records induced from the jaw-closing muscles during chewing efforts in seven volunteer subjects. The algorithm for automatic detection and measurement of the EMG silent period has been applied successfully to real EMG data and the performance of the software was confirmed to be sufficiently reliable. The results of the analysis are stored in a biosignal database for possible clinical use.

Adult↗