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Biomedical subjects

K Kadota

Publications and source records attributed to K Kadota.

At least 73 records · Page 4Linked to original sources
PubMed1997

Ectomesenchymoma of the medulla oblongata in a calf.

An ectomesenchymoma was found in a 62-day-old female calf, and examined immunohistochemically. The neoplastic cells were characterized by positive immunostaining for neurofilaments, glial fibrillary acidic protein, alpha smooth muscle actin, myoglobin, and keratin. This tumour, which displayed neurocytic, astrocytic, and myoblastic differentiation, may have arisen from pluripotential ectomesenchyme. Brain tumours showing multidirectional phenotypic expression presumably occur mainly in fetuses or calves.

Animals↗
PubMed1997

[Usefulness of directional coronary atherectomy as a bail-out device for acute closure after coronary angioplasty].

The usefulness of directional coronary atherectomy (DCA) as a bail-out device for acute closure (reclosure) after percutaneous transluminal coronary angioplasty (PTCA) was evaluated. PTCA was performed in 1,023 patients (182 with acute myocardial infarction) between January 1993 and January 1994 in our hospital. Thirty-one patients (11 with acute myocardial infarction) suffered acute closure (reclosure) after PTCA. In six patients (five with acute myocardial infarction), DCA was performed as a rescue treatment for acute closure (reclosure). In three of these patients, angioscopy was performed before DCA, which demonstrated intimal tear and some thrombi although coronary angiography showed no evidence of thrombus. Bail-out DCA was successful in all six patients without complications. DCA is useful as a bail-out device for acute closure (reclosure) after PTCA when the thrombus is not massive.

Angioplasty, Balloon, Coronary↗
PubMed1996

Proximal branching patterns of middle cerebral artery (MCA) in rats and their influence on the infarct size produced by MCA occlusion.

The branching patterns of the proximal middle cerebral artery (MCA) and their influence on the infarct size following MCA occlusion in rats were studied. In the proximal part from the level of the olfactory tract, the MCA most often presented one surface branch extending anteriorly, with a variable number of surface branches extending posteriorly. We classified the branching patterns of the posteriorly extending surface branches as follows: Type 1 (57.5%), one prominent proximal surface branch; Type 2 (30.2%), no prominent branch but two or more small surface branches; and Type 3 (12.3%), no surface branches with a visible junction with the MCA but surface branches probably arising from the internal carotid artery at the origin of the MCA. When the proximal surface branches (especially that in Type 1) remained uncoagulated, the infarct size in both the cortex and striatum was significantly reduced compared with that when coagulation was proximal to the most proximal surface branch. The reduction of cortical and striatal infarct sizes was particularly prominent in the posterior portion. To increase the infarct size and reduce variability, it is suggested that the MCA trunk should be coagulated from the origin to the rhinal fissure including the surface branches.

Animals↗
PubMed1996

Acute myeloblastic leukaemia in a cow.

A myeloblastic leukaemia was found in a 6-year-old Holstein cow. Although macroscopical lesions were not found in parenchymal organs, the animal had many neoplastic cells in the peripheral blood, bone marrow, lymph nodes, and spleen. By light microscopy most neoplastic cells appeared to be agranular blast cells, but some cells contained acidophilic granules and stained positively for naphthol AS-D chloroacetate esterase and lysozyme. Ultrastructural examination revealed that many of the blast cells had a few peroxidase-positive granules and corresponded to early promyelocytes.

Animals↗
PubMed1996

Intestinal adenocarcinoma with neuroendocrine cells in a clouded leopard (Neofelis nebulosa).

Adenocarcinoma of the small intestine was found in a 6-year-old clouded leopard. This tumour was characterized by the presence of goblet and neuroendocrine cells. The latter were labelled positively for either serotonin, somatostatin, neurotensin, gastrin or secretin. These neuroendocrine cells were reduced in number in most of the metastatic lesions, including those of the mesentery, diaphragmatic pleura, lungs, liver and heart, and squamous metaplasia was detected in some metastatic sites.

Adenocarcinoma↗
PubMed1996

Ovarian sex cord-stromal tumours in cattle, with particular reference to the lamination of basal laminae.

Three cases of bovine sex cord-stromal tumours, including a sex cord tumour with annular tubules and two granulosa cell tumours, are described. These tumours had tubular structures and hyaline or eosinophilic bodies, composed of multilayered basal laminae. The present study suggests that bovine granulosa cell tumours of the ovary are able to show morphology similar to that of Sertoli cell tumours of the testis and that sex cord tumours with annular tubules arise from granulosa cells but indicate Sertoli cell differentiation.

Animals↗
PubMed1996

Expression of dopamine transporter at the tips of growing neurites of PC12 cells.

The four kinds of oligopeptides specific in amino acid sequence to a rat dopamine transporter (DAT), peptide-1-peptide-4, were chemically synthethized. An attempt to produce antipeptide antibodies against these oligopeptides was made with an in vitro immunization method. Two monoclonal antibodies, MAbs H-1a and H-1b, were produced against one of the oligopeptides, peptide-1. Western blot analysis confirmed that the two antibodies recognized an approximately 85,000 Da protein in a synaptosomal fraction prepared from the rat striatum but none in the fraction from the cerebellum. The specificity of the antibody to DAT was also confirmed by an antibody absorption test using two synthetic oligopeptides, one of which is specific only to DAT. These results have confirmed the specificity of the present antibody to DAT. The expression and subcellular localization of DAT were immunohistochemically examined with MAbs H-1a and H-1b in PC12 cells treated with nerve growth factor (NGF). The antibody labeled the surface of PC12 cells. When the cells were treated with NGF, the expression of DAT was significantly emphasized, first in the area mainly including the Golgi apparatus and rough endoplasmic reticulum and then on the surface of growth cones from the beginning of neurite outgrowth. DAT was detected by Western blot analysis in a microsomal fraction prepared from PC12 cells. The activity of DAT in the PC12 cells was pharmacologically confirmed by the uptake of [3H]-dopamine and blockade by uptake inhibitors. The NGF treatment doubled the dopamine uptake activity. GBR12909, a specific inhibitor of DAT, blocked the [3H]-dopamine at a concentration of 10(-7) M. The expression of DAT and norepinephrine transporter (NET) mRNA in the PC12 cells was examined by reverse transcriptase-polymerase chain reaction (RT-PCR). DAT mRNA significantly increased in the NGF-treated cells after 7 days of incubation, whereas NET mRNA markedly decreased.

Amino Acid Sequence↗
PubMed1996

[The prognostic factors in astrocytic tumors: analysis by the Kaplan-Meier method and the Weibull log-linear model].

As the prognosis of astrocytic tumors depends on various factors, identifying prognostic factors should be useful for developing strategies to cope with them. Between 1975 and 1994, more than 200 patients with astrocytic tumors were treated in Kagoshima University. Of these patients, 149 (grade I: 17, grade II: 42, grade III: 41, grade IV: 42, unproven: 7) have been followed up. Records of these patients were retrospectively reviewed for age at the time of initial symptoms, gender, histological grade (WHO), extent of tumor resection, radiation therapy, and administration of anticancer agents. We used the Kaplan-Meier method and the Weibull log-linear model to analyze the relation between survival time and these prognostic factors. Survival time was counted from onset of symptoms, and age of initial treatment was used as a covariant. The mean age of males at the initial diagnosis was 40.8 years (n = 77), and that of females was 39 years (n = 72). Using the Kaplan-Meier method, the mean survival time of the 149 patients was 101 months (males; 72.7 months, females; 134.5 months). Mean survival time of grade II was 144.3 months, that of grade III was 95.2 months, and grade IV (glioblastoma) was 15.9 months. Histological grades and mean ages of the groups showed a positive correlation. Among grades II, III and IV, the Kaplan-Meier survival curves were significantly different (p < 0.0001) according to the log-rank test. By the extent of surgical resection (subtotal or greater resection, partial resection, and less than partial resection), the mean survival time showed a significant difference (p < 0.05) on the log-rank test. However, we could not detect a significant difference in survival time between the group that received chemotherapy and the group which did not. The Weibull log-linear analysis indicated that gender, age, histological grade (WHO), extent of surgery, and dose of radiation therapy were prognostic factors. Covariants of grades II, III, and IV made survival time 0.314, 0.179, and 0.069 times as long as that of grade I. The survival time after "partial resection" became 1.415 times as long as the survival time after "less than partial resection". The covariant of "greater than subtotal resection" showed a prolonged survival time of 2.916 compared with that of "less than partial resection". As for age at treatment, the older the patient was, the shorter the survival time. The rate was 0.986 for each year of age. Irradiation of one Gy increased survival time by 1.015 times. Chemoimmunotherapy (dose of ACNU and interferon beta) could not be confirmed as an effective covariant.

Adult↗
PubMed1995

Leiomyosarcoma of soft tissue in a cow.

A 4-year-old Holstein cow developed a large neoplastic mass, which was formed in the deep soft tissue of the neck and removed surgically. The neoplasm was shown to be a smooth muscle tumour by the presence of alpha smooth muscle actin and fine intracytoplasmic filaments with focal densities. This malignant neoplasm showed extensive areas of necrosis and haemorrhage, high cellularity, marked pleomorphism, atypical giant cells and numerous mitoses with occasional abnormal figures.

Animals↗
PubMed1995

Sclerosing stromal tumour in a cow.

A case of sclerosing stromal tumour in an 8-year-old cow is described. The left ovary was entirely replaced by neoplastic tissue, whose features were pseudolobulation of cellular areas, intercellular oedema and calcified plaques. The neoplastic cells varied in morphology and were similar to ovarian stromal cells, theca cells or lutein cells. Immunohistochemically, S-100 protein, oestradiol and testosterone were detected in theca-like or luteinized cells, some of which had ultrastructural features suggestive of steroid hormone synthesis. In contrast, desmin and actin characterized slender spindle cells. This is the first report of a sclerosing stromal tumour in cattle.

Animals↗
PubMed1995

Granulomatous epididymitis related to Rhodotorula glutinis infection in a dog.

A 4-year-old, male Great Dane dog developed severe swelling of the scrotum on 9 December 1991, and the testes and epididymides were removed surgically on 12 December 1992. The cut surface of the epididymides consisted of hard connective tissue and several small abcesses with slight hemorrhage. Histopathologically, the seminiferous tubules in the testes had only a few spermatogenic cells, but Sertoli cells were well preserved. Both epididymides consisted entirely of a proliferation of fibrous connective tissue, and only a few ducts deferens containing cell debris, neutrophils, and macrophages in the lumina were present. In all lesions of the epididymides, the macrophages contained periodic acid-Schiff- and Grocott's silver-positive round granules, 5-8 microns in diameter. Microbiologically, smooth salmon-pink colonies consisting of ovoidal yeast, about 10 microns in diameter, were isolated from the samples of epididymides but not from those of the testes. The isolated yeast had microbiological characteristics of Rhodotorula glutinis. From these observations, we diagnosed the present case as granulomatous epididymitis due to Rhodotorula infection.

Animals↗
PubMed1995

Aneurysm of the distal anterior inferior cerebellar artery--case report.

A 38-year-old female presented with vertigo, right hearing disturbance, and slight headache which were treated medically. However, she suddenly developed severe headache with vomiting and vertigo. Computed tomography revealed subarachnoid hemorrhage, and right vertebral angiography disclosed a rare aneurysm at the distal portion of the anterior inferior cerebellar artery. She underwent a right suboccipital craniectomy in the lateral position. The aneurysm could not be clipped because the aneurysm was tightly adhered to the brainstem, so it was trapped. Postoperatively, she showed slight VIIIth to Xth cranial nerve disturbances. Three months postoperatively, the IXth and Xth cranial nerve disturbances had disappeared, but the tinnitus and right hearing disturbance were still present. The initial symptoms were probably caused by minor bleeding from the aneurysm.

Adult↗
PubMed1995

Expression of a dopamine transporter in PC12h cells: an immunohistochemical study with an antipeptide antibody.

Two kinds of oligopeptides, based on the amino acid sequences of No. 217-232 and 374-387 of a rat dopamine transporter, were designed and chemically synthesized. Five clones of the monoclonal antibodies against these peptides were produced with the in vitro immunization method. Two of them have recognized a protein of M(r) approximately 85,000 in a synaptosomal fraction of the rat striatum. It is probable that the protein M(r) approximately 85,000 corresponds to a dopamine transporter in the nerve terminal of the dopamine neurons in the striatum. The expression of dopamine transporter was immunohistochemically examined with these antibodies in PC12h cells. The immunoreactivity was detected on the surface membrane of the cells.

Animals↗
PubMed1995

[Ventilatory insufficiency due to upper cervical injury treated by diaphragm pacing: a case report].

A 33-year-old man suffered chronic ventilatory insufficiency with tetraplegia after an operation for atlantoaxial dislocation. He was alert and his tetraplegia gradually improved. However, continuous mechanical ventilation was necessary for him. Thirteen months after the operation, a diaphragm pacer (Avery Laboratory Inc.) was implanted on the right phrenic nerve in the cervical region. Nineteen days after the implantation of the right side pacer, a left side diaphragm pacer was also implanted. Diaphragm pacing was started two weeks after the second implantation. The pacing period was gradually prolonged and continuous pacing for 9 hours by the right side pacer and three hours by the left side pacer was able to be obtained. One year after implantation, twelve continuous hours of diaphragm pacing became possible. During diaphragm pacing, blood gas analysis was satisfactory and the patient could move sitting on a wheel chair, watch television and write letters using a word processor. We were unable to achieve total ventilatory support for him using these diaphragm pacers. We thought that the main cause of our partial failure originated from the procedure used in implanting the electrode onto the phrenic nerve. Left side pacing needs higher amplitude than that used on the right side to obtain sufficient tidal volume. The patient refused our continuing the left side pacing because of pain around the anterior chest and shoulder. Another problem to be watched is diaphragm fatigue. However, diaphragm pacing has been continued for six years and it has been useful in improving his quality of life.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Local chemotherapy for malignant brain tumors using methotrexate-containing fibrin glue].

Fibrin glue (FG) is an agent developed for achieving hemostasis and the adhesion of living tissue during surgical operations. Incorporation of a drug into FG may be expected to have a sustained local release. In the present study, methotrexate (MTX) included in FG (FG-MTX) was used. The release of MTX into human plasma and cerebrospinal fluid was studied by in vitro study to confirm the sustained release effect of this preparation, by in vivo study, in which the antitumor effect of FG-MTX was assessed in rats bearing 9L-gliosarcoma subcutaneously; and clinically, FG-MTX therapy was attempted in patients with malignant brain tumors. The in vitro study showed that MTX levels rapidly decreased over 1 to 3 days, but was still detected on days 7 and 14. The results showed the sustained release effect of MTX. The in vivo study showed that in the FG-MTX group, all tumors began to decrease soon after administration and disappeared in four out of five animals (80%) on about day 10. In the clinical study, sustained release for more than one week was found, and tumor decrease occurred in the case of a malignant brain tumor. Thus, FG-MTX appears to provide an effective local chemotherapy.

Animals↗
PubMed1994

An immunohistochemical study of peripheral neuroblastoma, ganglioneuroblastoma, anaplastic ganglioglioma, schwannoma and neurofibroma in cattle.

Immunohistochemical analysis of five paraffin wax-embedded neoplasms was performed to elucidate the characteristics of bovine nervous-tissue tumours. In case 1 (peripheral neuroblastoma), the neoplastic tissue was characterized by the formation of true and Homer-Wright rosettes and the existence of neuron-specific enolase. The neoplastic cells were possibly more immature than those of common neuroblastomas, because similar features are observed in human malignant neuroepitheliomas. The neoplastic cells in case 2 (ganglioneuroblastoma) ranged from large cells with abundant neurofilaments to immature small cells, rarely with neurofilaments or glial fibrillary acidic protein (GFAP). Such expression suggests the presence of pluripotential cells. The neoplastic tissue in case 3 (anaplastic ganglioglioma) was strikingly polymorphous, and had five elements; neuronal, astrocytic, oligodendrocytic, spindle cell and small oval cell. The neoplastic neurocytes and astrocytes were, respectively, characterized by neurofilament and GFAP positivity. The neoplastic oligodendrocytes made a honeycomb appearance, and the neoplastic spindle cells and small oval cells were considered to be less differentiated. The tumours of cases 2 and 3, which contained poorly differentiated cells and revealed both neuronal and glial differentiation, may be specific to calves. In case 4 (schwannoma), almost all the neoplastic cells were positive for S100 protein, while S100-negative fibroblasts were present in many areas of case 5 (neurofibroma). These two tumours were readily distinguished histologically and immunohistochemically.

Animals↗