Biomedical subjects

K Takada

Publications and source records attributed to K Takada.

At least 577 records · Page 32Linked to original sources

PubMed1990

[Selective segmental sclerotherapy of the liver by transportal ethanol injection--a complete remission case of hepatocellular carcinoma].

Selective segmental sclerotherapy of the liver by transportal ethanol injection (SSS) was devised and evaluated in a case of hepatocellular carcinoma. The patient was a 72-year-old man suffering from unresectable hepatoma. Injected ethanol with an amount of 20 ml into the portal branch under occluding the portal flow by balloon catheter produced complete necrosis of the liver proportional to the injected liver segment including the tumor on CT. Because of ethanol perfusion into sinusoid level by wedge injection, its cytotoxicity maybe affected liver cells directly. In this case, there has been no evidence of inadvertent liver damage and a significant rise in the blood ethanol level. The present technique of SSS in this clinical case and our past animal experience seemed to yield the same condition as resection without surgical disadvantages and be apparently a safe method, which is suggested for clinical use for several hepatic tumors.

Aged↗

PubMed1990

Use of bovine lung heparin to obviate anaphylactic shock caused by porcine gut heparin.

Intracardiac repair in a 7-year-old girl with tetralogy of Fallot was hampered because of an anaphylactic reaction with cardiopulmonary collapse caused by porcine gut heparin. This patient had an extremely rare case of hypersensitivity to porcine gut heparin but not to bovine lung heparin. Uneventful radical operation could be performed with the use of bovine lung heparin for systemic heparinization during cardiopulmonary bypass.

Anaphylaxis↗

PubMed1990

Sex difference in inhalation toxicity of p-dichlorobenzene (p-DCB) in rats.

The organ distribution and toxicity of p-dichlorobenzene (p-DCB) were compared in male and female rats after inhalation of 500 ppm of p-DCB for 24 h in a whole-body chamber. Concentrations of p-DCB in the serum, liver, kidney and fatty tissues were measured by gas chromatography at intervals during and up to 24 h after the treatment. Though no significant differences in the serum levels were observed between male and female rats, the p-DCB values in the livers of female rats were significantly higher than those of male rats. Conversely, significantly higher levels were found in the kidneys of male than of female rats. The distribution results thus appeared to correlate with the fact that nephrotoxic changes were observed only in male rats and that the appearance of minor hepatotoxic changes was limited to females.

Adipose Tissue↗

PubMed1990

Cerebellar micropolygyria in Fukuyama congenital muscular dystrophy: observations in fetal and pediatric cases.

Cerebeller micropolygyria in Fukuyama congenital muscular dystrophy (FCMD) was examined neuropathologically by three-dimensional reconstruction and immunohistochemistry in one fetal and two children's cases. In the children's cases, a complex columnar network of the molecular layer was mixed with clusters of the granular cell layers, often associated with central blood vessels. Although primitive, cortical dysplasia was also obvious in the fetal cerebellum at 23 weeks of gestation. Ectopic glial proliferation was less extensive than that in the cerebral cortex. It is suggested that leptomeningeal disruption, superficial proliferation of mesenchymal tissue and subsequent mixture of neuroglial and mesenchymal tissues, which may occur transiently during the fetal period in the developing FCMD cerebellum as well as in the cerebrum, play substantial roles in the development of cerebellar cortical dysplasia.

Cerebellum↗

PubMed1990

Taxonomy of Trichophyton interdigitale (Trichophyton mentagrophytes var. interdigitale) by restriction enzyme analysis of mitochondrial DNA.

The relationship between Trichophyton interdigitale (Trichophyton mentagrophytes var. interdigitale) and the other members of the T. mentagrophytes complex was studied by restriction enzyme analysis of mitochondrial DNA (mtDNA). The mtDNA of 22 isolates of T. interdigitale from Japanese patients with dermatophytosis was extracted, digested with the restriction enzymes Hae III, Msp I, or Hind III, and the restriction profiles obtained compared with those of Arthroderma simii, Arthroderma benhamiae and Arthroderma vanbreuseghemii. The restriction profiles obtained for T. interdigitale were identical to those of A. vanbreuseghemii. Thus, these two species are considered to be closely related.

Ascomycota↗

PubMed1990

Effect of chemical carcinogens on cholesterol biosynthetic pathways in the skin of mice.

The metabolism of zymosterol and mevalonic acid was studied in vitro using the skin homogenates of 3-methylcholanthrene (3MC), diazacholesterol-treated and untreated mice. In normal mouse skin only lathosterol was a major metabolite and the other metabolites, cholesta-5,7,24-trien-3 beta-ol, desmosterol, cholesterol and 7-dehydrocholesterol were much less abundant. However, in the skin homogenate of mice treated with 3MC lathosterol production was depressed, while the production of cholesta-5,7,24-trien-3 beta-ol and desmosterol was significantly increased, the cholesterol level being normal or a little higher. In contrast, in the skin homogenate of mice administered diazacholesterol the production of both lathosterol and cholesterol was almost completely blocked with the slightly increased production of cholesta-5,7,24-trien-3 beta-ol and desmosterol. The metabolism in vitro of [2-14C]-mevalonic acid was quite similar to that of zymosterol, and no additional product which might possibly have been produced by the Kandutsch-Russell pathway was observed. Two pathways for cholesterol biosynthesis, therefore, may exist in mouse skin; the first is lanosterol----zymosterol----5 alpha-cholesta-7,24-dien-3 beta-ol----lathosterol----7-dehydrocholesterol----cholesterol, and the second by Bloch: lanosterol----zymosterol----5 alpha-cholesta-7,24-dien-3 beta-ol----cholesta-5,7,24-trien-3 beta-ol----desmosterol----cholesterol. When mouse skin is treated with 3-MC the former pathway is virtually blocked and the latter is stimulated, keeping the level of cholesterol in the tissue constant or a little higher than normal, which seems to be a significant change in the early stage of chemical carcinogenesis.

Animals↗

PubMed1990

Changes in negative symptoms of schizophrenic patients two years later.

This study investigated the course of negative symptoms by examining the psychiatric symptoms of 59 new schizophrenic patients at the first consultation and again two years later using a structured interview--the Present State Examination. An examination of the total score of the nine negative symptoms, included in the "Chronic Schizophrenic Syndrome" by Wing, showed that 27 out of the 59 patients (45.8%) had lower symptom scores two years later than they did at the first consultation ("negative symptom improvement" group), while 20 patients (33.9%) had higher scores two years after the first consultation ("negative symptom deterioration" group). There were 12% more patients in the improvement group than in the deterioration group. No significant differences were observed between the "improvement group" and "deterioration group" in relation to the following factors--subclassification of schizophrenia, mode of onset, age at the first consultation, marital status at the time of onset, academic history, employment status prior to the onset, the history of hospitalization after the onset and maintenance therapy of neuroleptics. In relation to psychiatric symptoms at the first consultation, the patients in the "improvement group" had a variety of symptoms compared to the patients in the "deterioration group," and the presence of "incoherence of thought," "delusion of reference" and "special features of depression" was significantly higher in the improvement group than in the deterioration group.

Adolescent↗

PubMed1990

Hereditary motor and sensory neuropathy type 1 (HMSN1) associated with cranial neuropathy: an autopsy case report.

A family with hereditary motor and sensory neuropathy type 1 (HMSN1) is reported. Three patients suffered only pupillary abnormality, two patients showed Adie's syndrome and peripheral neuropathy, and one had cranial neuropathy. Adie's syndrome and severe peripheral neuropathy. Autopsy of the latter revealed reduction of myelinated nerve fibers in the trigeminal, facial and hypoglossal nerves. There was extensive degeneration of the posterior column of the spinal cord. At the anterior horns, loss of motor neurons was observed, particularly at the lumbar level. The anterior and posterior roots showed loss of myelinated fibers. HMSN1 is only rarely associated with cranial neuropathy, and this is probably the first autopsy-proved case.

Adie Syndrome↗

PubMed1990

Relationship between proliferation and cell cycle-dependent Ca2+ influx induced by a combination of thyrotropin and insulin-like growth factor-I in rat thyroid cells.

The mechanism of cell proliferation by a combination of thyroid-stimulating hormone (TSH) and insulin-like growth factor-I (IGF-I) was studied in rat thyroid (FRTL-5) cells. IGF-I stimulated an approximately 3.5-fold increase in the rate of Ca2+ influx sustained for at least 6 h in TSH-pretreated cells but not in quiescent cells. The significant cell proliferation was observed when TSH-primed cells were incubated with IGF-I for 24 h but not for 12 h. IGF-I stimulated the rate of Ca2+ influx in a dose-dependent manner that was similar to that for induction of DNA synthesis. Both Ca2+ influx and DNA synthesis observed in response to IGF-I in TSH-primed cells were inhibited by cobalt. In addition, the stimulations of Ca2+ influx and DNA synthesis by IGF-I were dependent on extracellular Ca2+ in TSH-pretreated cells. When TSH-primed cells were pretreated with pertussis toxin, both IGF-I-induced Ca2+ influx and DNA synthesis were abolished. However, pertussis toxin did not block the priming action of TSH or forskolin. When calcium entry was induced by Bay K8644, it stimulated cell growth in TSH-primed cells but not in quiescent cells. Moreover, cobalt and lanthanum inhibited DNA synthesis even when added several hours after the addition of Bay K8644 but not when added 24 h after the growth factor in TSH-primed cells. These findings suggest that at least two important mechanisms may work in response to IGF-I only in the TSH-primed G1 phase of the cell cycle: first, IGF-I can activate directly or indirectly the Ca2+ channel via a pertussis toxin-sensitive substrate in TSH-primed cells; and second, a long lasting calcium entry by IGF-I may be a cell cycle-dependent mitogenic signal.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1990

[Assessment of drug effects on memory by delayed discrimination responses in rats].

Delayed discrimination experiments were conducted to examine drug effects on memory in rats. Three kinds of experimental situations: a Y-maze, an operant chamber with two retractable levers, and an operant chamber with two fixed levers were used. A discriminative stimulus light either on the left or the right side of a stimulus panel was presented for a brief period in each situation. After a certain delay time following extinguishment of the light, a choice response to the previously lighted side was termed as a correct choice. Scopolamine at 0.015-0.06 mg/kg, s.c., decreased the correct choice ratio in trials with a delay time of 0 sec in the Y-maze situation and in trials with longer delay times in the operant chamber situations. Nicotine at 0.06-1 mg/kg, s.c., decreased the correct choice ratio in trials with a delay time of 0-4 sec in the Y-maze situation, a delay time of 4 sec in the retractable-lever operant chamber situation, and a delay time of 0.1 sec in the fixed-lever operant chamber situation. Using this delayed discrimination procedure, drug effects on the relationship between delay time and correct choice ratio were observed. From these results, the present procedure was found to be useful for the evaluation of drug effects on memory in rats.

Animals↗

PubMed1990

Antigen-presenting capacity in patients with sarcoidosis.

Antigen-presenting capacity by monocytes and AMs was determined in 13 patients with sarcoidosis and nine healthy control subjects, using PPD as the antigen. The patients and healthy control subjects all had positive PPD skin tests. Monocytes from both the control subjects and the patients with sarcoidosis exhibited antigen-presenting capacity to autologous peripheral T-lymphocytes, without any significant difference between the two groups. The AMs from patients, but not control subjects, demonstrated antigen-presenting capacity to autologous peripheral T-lymphocytes. Antigen-presenting capacity by monocytes and AMs to lung T-lymphocytes was lower than to peripheral T-lymphocytes, but not significantly. Antigen-presenting capacity was not significantly different between patients with sarcoidosis who had positive and negative PPD skin tests. The mechanism of enhanced antigen-presenting capacity by AMs in sarcoidosis is uncertain at present, but no significant difference was observed in DR antigen expression on AMs between controls and patients with sarcoidosis, and the addition of exogenous IL-1 or IFN-gamma did not induce antigen-presenting capacity by AMs in controls, suggesting that neither increased DR antigen expression on AMs nor increased release of IL-1 or IFN-gamma from AMs is responsible. Thus, these results suggest that T-lymphocyte activation in sarcoidosis may in part be attributable to an enhanced antigen-presenting capacity by AMs.

Antigen-Presenting Cells↗

PubMed1990

[Evaluation of immunotoxicity testings using azathioprine-treated rats: the International Collaborative Immunotoxicity Study (Azathioprine)].

The immunotoxicological effects of azathioprine (AZP) were examined by enhanced histopathological and function tests in the rat which is routinely used in toxicological tests. Male F344 rats were orally administered AZP in doses of 0, 2.5, 12.5 and 25.0 mg/kg/day for 28 days. Reductions in the organ weights of the thymus, spleen, liver, kidney, and testis in a dose-dependent manner were confirmed. Hematological examination revealed a marked decrease in the number of WBCs, which was associated with a decrease in the number of lymphocytes. In the femoral bone marrow, a significant reduction in the total cell number attributed to the decrease in the number of lymphocytes and granulocytes was observed. Histopathologically, atrophy and obfuscation of the corticomedullary junction in the thymus, the decrease of lymphocytes in the thymus and spleen, and the disappearance of germinal centers in the lymph nodes were observed. As for the functional testings, azathioprine treatment did not affect remarkably the PFC number and the NK cell activity per unit spleen cell number. However, the total spleen cell number per spleen was decreased in a dose-dependent manner. Therefore, the total functional activities (PFC and NK) per spleen were decreased. Thus, in the AZP-treated F344 rats, it was shown that the enhanced histopathological tests were useful to evaluate potential risks to the immune system.

Animals↗

PubMed1990

[Twenty-eight-day repeated dose toxicity test for tetrachlorvinphos in Wistar rat].

A 28-day oral toxicity test of tetrachlorvinphos (TCV) was conducted in male and female Slc: Wistar rats by gavage at dose levels of 0, 10, 100 or 1000 mg/kg/day. The male and female rats showed dose-related inhibition of serum cholinesterase activity and erythrocyte acetylcholinesterase activity. At a dose of 1000 mg/kg, body weight gain was decreased in males, and there were 6 deaths in females. Adrenal gland, liver, kidney and thyroid gland weights were increased. The adrenal lesions were characterized by vacuolization and swelling of the cortex cells. The hepatic lesions consisted of vacuolization and necrosis of the hepatocytes. The renal lesions consisted of regeneration and necrosis of the tubular epithelial cells. These lesions were mostly observed at a dose of 1000 mg/kg. After a 14-day recovery period in the 1000 mg/kg group, the changes of cholinesterase, total cholesterol, gamma-glutamyltransferase, alkaline phosphatase, aspartate aminotransferase and blood urea nitrogen in serum were restored or showed a tendency toward recovery. However, the lesions in the kidney and adrenal remained. More than 14 days are therefore considered to be needed for recovery. At doses of more than 10 mg/kg, significant inhibition of the serum cholinesterase activity in both sexes, erythrocyte acetylcholinesterase activity in males, and lesions of the adrenal gland in females were observed. Target organs for TCV-treated rats were the adrenal, liver and kidney. It was concluded that the NOEL under this experimental condition is less than 10 mg/kg/day.

Administration, Oral↗

PubMed1990

[Pure white cell aplasia (PWCA) with an inhibitor against colony-forming unit of granulocyte-macrophage (CFU-GM)].

We reported here a case of pure white cell aplasia (PWCA). A 23-year-old man was admitted to our hospital in September 1989 because of agranulocytosis, fever, and anal pain. He had no history of toxic-drug exposure or blood transfusion. Laboratory studies were all within the normal range except white blood cell count of 2,300/microliters with no neutrophils and low serum IgA level (28 mg/dl). Bone marrow examination showed hypocellular with erythroid predominance and no granulocyte maturation beyond the myelocyte. Complement-dependent suppression of autologous and heterologous granulocyte-macrophage colony-forming units by the patient's serum could be demonstrated. Though corticosteroid administration was ineffective, neutropenia improved by plasmapheresis. Furthermore, recombinant granulocyte colony stimulating factor (rG-CSF) could release him from persistent bacterial infection of anal fistula by transient improvement of neutropenia. These findings suggest a humoral autoimmune mechanism for the pathogenesis of PWCA and the effectiveness of rG-CSF for the patient with severe infections.

Adult↗

PubMed1990

Possible involvement of bone cells in a new cementum formation.

Cells from the gingival lamina propria, bone-derived granular tissues and periodontal ligament (PDL) were isolated after periodontal surgery and subsequently cultured in vitro. The resulting cells were defined as gingival cells, bone cells and PDL cells, respectively. Under a phase contrast microscope, the cultured cells exhibited a spindle and/or a polyhedral shape. On the basis of their appearance under an electron microscope, spindle-shaped cells and polyhedral-shaped cells were identified as fibroblasts and osteoblasts, respectively. Bone cells, a homogeneous population of osteoblasts, had a more rapid growth ability than PDL cells, which were a heterogeneous population of fibroblasts and osteoblasts. Of particular interest was that only bone cells produced bone matrix in the multilayers in vitro. These results support the hypothesis that the phenotype expressed by cells from the alveolar bone establishes a new concept for progenitor cells in the formation of cementum.

Alveolar Process↗

PubMed1990

[Coronary circulation, myocardial metabolism and cardiac catecholamine flux in patients with syndrome X].

To clarify the pathogenesis of syndrome X (Sx), hemodynamics, coronary circulation, myocardial lactate metabolism and cardiac catecholamine flux were studied before and during bicycle ergometry in 25 patients (pts) and these data were compared with those in 15 with effort angina (EA) and in eight controls. The results were as follows: 1. The cardiac index during exercise decreased in EA pts probably due to their coronary lesions, while those in the controls and Sx were well preserved. 2. An increase of coronary blood flow during exercise, both in Sx and EA pts, was significantly impaired and the myocardial extraction ratio of lactic acid was significantly lower compared with those in the controls. The cardiac norepinephrine release during exercise was markedly higher in Sx, compared with that in controls and in EA. These results suggested that in Sx, excessive sympathoadrenergic stimulation may play an important role in restricting coronary reserve and in accelerating myocardial anaerobic metabolism.

Angina Pectoris↗

PubMed1990

Prevalences of malocclusions and dental caries in molars in female adolescents.

Prevalences of malocclusions and dental caries in molars were investigated on a database of high school students collected between 1977 and 1986. A total of 6,665 schoolgirls were evaluated. The proportions of 54.1% in the seventh grade and 56.6% in the tenth grade students were judged as having malocclusions. The prevalences of dental caries for the lower first and the second molars were significantly higher (p less than 0.001) than those for the upper opponents during the observation period. The prevalence of dental caries increased linearly for all kinds of molars in accordance with age, but they were lower than those reported by the Ministry of Health and Welfare in Japan determined for the entire nation. The percent of dental caries for the second molars revealed abrupt increases from 10% at the seventh grade to 50% at the 12th grade. These changes were particularly noticeable between the eighth and the tenth grades. These results suggest the significance of oral health care education during the adolescent period based on a long-term cooperation made by dentists, school nurses, teachers through the participation of students into the oral health care programme.

Adolescent↗

PubMed1990

[A cephalometric, electromyographic and kinesiographic appraisal of a patient with mandibular prognathism and anterior openbite malocclusion before and after surgical orthodontic therapy: a case report].

A 19-year-old female patient with skeletal 3 and anterior openbite malocclusions was treated by a surgical orthodontic approach. A glossectomy was also performed. Cephalometric, electromyographic and kinesiographic records were taken before and after the treatment. The treatment results were as follows: 1. Esthetic improvement in facial profile and static alignment and intercuspation of teeth was obtained. 2. The dimension of the tongue with respect to that of the oral cavity proper measured on the lateral cephalograms revealed a value similar to that determined for the control data after the active treatment. 3. The proportion of reversed strokes with respect to the total chewing strokes increased at the completion of the active treatment both for the right- and the left-sided chewings, but it decreased during the retentive period. 4. At the initial stage, an earlier onset of the masseter muscle activity relative to the temporal muscle group was determined, while the temporalis muscles showed an earlier onset of activity in the postoperative phase. 5. The durations of chewing strokes became shortened in a postoperative phase both on the working and the balancing sides. This observation was particularly significant for the opening and the closing phases. In addition, the proportion of the duration of significant temporalis muscle activity with respect to that of the concomitant chewing stroke increased. 6. Anterior temporalis muscle and masseter muscle activity during clenching performance revealed a value similar to the control data. In summary, the current case suggests that the patients who receive surgical orthodontic treatment require sufficient time to obtain functional readaptation during the retentive period.

Adaptation, Physiological↗