Biomedical subjects

Y Kida

Publications and source records attributed to Y Kida.

At least 91 records · Page 5Linked to original sources

PubMed1994

[Clinical presentations and MRI findings of angiographically occult vascular malformations].

Various clinical features as well as MRI findings of AOVM (angiographically occult vascular malformation) were studied. Amongst our patients, since January 1988, there have been 30 cases of symptomatic AOVM (20 males, 10 females) including 3 cases with multiple lesions. The age ranged from 3 to 60 years of age, with a mean of 33.4 years. The locations of symptomatic lesions were in the cerebral hemisphere (15), the thalamus (4), the brain stem (8) and in the cerebellum (3). The initial presentations of these 30 cases were either by hemorrhage (18), convulsive seizure (9) or by progressive neurological deficits (3). The initial presentation was not related to the patient's age and the size of the lesion, but apparently related to the location of AOVM. Most of the lesions in the cerebral hemisphere presented seizures, but all of the lesions in the thalamus, the brain stem and the cerebellum disclosed hemorrhage as an initial presentation. In fact it was noticed that brain stem lesions tend to cause repetitive hemorrhage in a relatively short period. AOVM lesions were clearly visualized with T2-weighted MRI images, consisting of high intensity cores with surrounding low intensity rims. Most of the symptomatic lesions were partially enhanced by Gd-DTPA with varied intensity. Dynamic changes in size and enhancement pattern on MRI were occasionally seen, usually accompanied with episodes such as hemorrhage or neurological deterioration. Although AOVMs were angiographically negative some strands indicating draining veins were observed on MRI in several cases. In contrast, none of the nonsymptomatic lesions (22 lesions) demonstrated enhancement effects with Gd-DTPA.

Adolescent↗

PubMed1993

Gastric adenocarcinoma with differentiation to sarcomatous components associated with monoclonal Epstein-Barr virus infection and LMP-1 expression.

A case of gastric adenocarcinoma with sarcomatous differentiation in a 65-year-old male was investigated for possible association with the Epstein-Barr virus (EBV). The presence of EBV-DNA could be proven by the polymerase chain reaction (PCR), and EBERs signals were detected in tumour nuclei, strongly in sarcomatous areas and weakly elsewhere. Monoclonal EBV infection was evident in terms of a single band of lymphocyte determined membrane antigen demonstrated by the PCR method. Latent membrane protein 1 was strongly positive in cells of sarcomatous components but very weakly positive in carcinoma components. EBV-determined nuclear antigen-2 was absent in both. This case of adenocarcinoma suggests that EBV plays an important role in tumorigenesis, contributing in particular to sarcomatous differentiation.

Adenocarcinoma↗

PubMed1993

[A case of pulmonary aspergillosis by immunodiagnosis during remission induction therapy of acute myelocytic leukemia].

The frequency of a visceral mycosis grows definitely higher with an immunocompromised host. Invasive fungal infection can be controlled by means of development of early diagnosis and antifungal therapy. In these types of cases, it is difficult to establish an antemortem diagnosis of invasive pulmonary aspergillosis and most of them were diagnosed postmortem. A patient was diagnosed as aspergillosis from the clinical and serological features. This patient underwent successful therapy during remission induction therapy of acute myelocytic leukemia (AML). A 26-year-old male was admitted to our hospital because of leukocytosis with a diagnosis of AML made by reviewing peripheral blood smears and bone marrow aspirate. After remission induction therapy, he was still febrile in spite of treatment with a broad spectrum antibiotics and empiric therapy of fluconazole. Unfortunately shadowing appeared on the chest radiograph and aspergillus antigen was detected from the serum and the sputum. Consequently, the patient who suffered from invasive pulmonary aspergillosis was diagnosed and treated with intravenous amphotericin B and flucytosine. The radiological shadow improved but AML relapsed, therefore, remission induction therapy of AML was started again but he died of sepsis caused MRSA. In the postmortem histopathological examination the lung tissues, the hyphae could not be confirmed while, in immunohistochemical examinations of the lesion at the left S8, aspergillus antigens were detected around the small necrotic lesions and in the polymorphologic giant cells. We emphasize that invasive pulmonary aspergillosis is very difficult to diagnose whereas active examinations and clinical early diagnosis may lead to more effective therapy and the prognosis.

Adult↗

PubMed1993

Magnetic resonance angiography of arteriovenous malformation in the brainstem.

The magnetic resonance (MR) angiography appearance of arteriovenous malformation (AVM) in the tegmentum and pons is described. The interpeduncular perforating branches of the posterior cerebral artery and median pontine branches of the basilar artery were seen more clearly by MR angiography than by conventional angiography. MR angiography was very useful for the follow-up of AVM after stereotactic radiosurgery.

Adolescent↗

PubMed1993

Magnetic resonance angiography of arteriovenous malformation in the thalamus.

A comparative study of magnetic resonance angiography and conventional angiography of arteriovenous malformation in the thalamus showed that both methods clearly visualized the feeding arteries: perforating branches of the posterior cerebral artery, posterior choroidal artery and lenticulostriate artery. Draining veins such as the internal cerebral vein were also demonstrated well.

Adolescent↗

PubMed1993

[Gamma-radiosurgery of metastatic brain tumors].

Twenty-six cases of various brain metastases were treated with Gamma-knife. Their primary sites were: lung in 13, colon in 5, breast in 2, kidney in 2, liver in 1, ovary in 1, and a malignant melanoma. The origin of one case was not verified. There were 11 single and 15 multiple metastases. In total 70 tumors were involved. Following localization with MRI and dose planning using a computer system, radiosurgery was carried out. Tumors were treated with the maximum dose between 24 and 50Gy, and with the marginal dose between 12 and 25Gy. Early follow-up results demonstrated favorable responses chiefly by tumor shrinkage, central tumor necrosis or by decreased peritumoral edema. In fact after radiosurgery, the rates of tumor shrinkage were 55.7%, 61.8% and 66.7% at 3, 6 and 9 months respectively. The tumor control rates, including regressed and stable tumors, were 98.6%, 97.1 and 85.7 at 3, 6 and 9 month intervals respectively. Meanwhile, 14 cases were neurologically improved, and another 4 showed either no perceivable change. Neurological deterioration occurred in 4 cases by progression of brain metastasis in 2 and by perifocal edema after radiosurgery. Recurrent brain metastases occurring after radiosurgery were treated with a repetition of Gamma-knife surgery in 4 cases, resulting in good tumor control. In conclusion most of the brain metastasis can be well controlled by radiosurgery for relatively long period of time.

Adult↗

PubMed1993

[Prognosis of periventricular echodensities--its relationship with periventricular leukomalacia].

We studied periventricular echodensities (PVE) in 154 premature infants under 33 weeks of gestational age. PVEs were classified into four groups due to Pidcock's description, and its relation with periventricular leukomalacia (PVL) was examined as a cause of cerebral palsy. Twelve (11%) of 112 infants with PVE 2 and all of 10 infants with PVE 3 were developed cystic PVL. PVE 3 was therefore considered to be the same as the pathological PVL. Infants of PVE 2 - 3 groups were more premature and lower in birth weight, and they were more often complicated with respiratory distress syndrome, asphyxia, recurrent apneic episode, patent ductus arteriosus and hypocarbia than those of PVE 0 - 1 groups. PVE 2 disappeared in patients with PVL later than in those without PVL.

Electroencephalography↗

PubMed1992

Argyrophilic nucleolar organizer regions in human adrenocortical neoplasms.

Argyrophilic nucleolar organizer regions (AgNOR) in human adrenocortical neoplasms, including five carcinomas and ten adenomas, were studied using a semi-automatic image analyzer. Both the number and total area of AgNOR per nucleus in the carcinomas were found to be statistically greater than in adenomas and control tissues. However, there were no statistically significant differences in total AgNOR area per nuclear area or in the mean area of individual AgNOR dots. The AgNOR of neoplastic and normal cells were of four morphological types: type 1 had a few dots at the periphery of the nucleus, type 2 a few dots at the center, type 3 a large round dot along with several small ones at the center, and type 4 numerous diffusely distributed polymorphic dots. Most type 3 and 4 cells were found in carcinoma cases. Type 1 cells decreased in proportion to the severity of biological malignancy. It follows from these findings that careful observation of AgNOR should facilitate the distinction of malignant from benign adrenocortical neoplasms.

Adenoma↗

PubMed1992

Increase in cardiac muscle fructose content in streptozotocin-induced diabetic rats.

To evaluate the activation of the sorbitol pathway in cardiac muscle in diabetic rats, we measured sorbitol, fructose, and myo-inositol content in cardiac tissue obtained from control and streptozotocin-diabetic rats, with or without an 8-week insulin treatment, using gas chromatography-mass spectrometry (GC-MS). Cardiac fructose and sorbitol content in 10-week diabetic rats increased by 60-fold and 3.9-fold of those of control rats, respectively (P less than .001). In contrast, cardiac myo-inositol content in 10-week diabetic rats decreased to 56% (P less than .025) of the control value. The abnormalities in cardiac fructose, sorbitol, and myo-inositol content were completely normalized by the 8-week insulin treatment, which was initiated 2 weeks after the induction of diabetes. There was no difference in cardiac aldose reductase activity between control and diabetic rats. However, cardiac sorbitol dehydrogenase activity in diabetic rats was 151% (P less than .005) higher than that of control rats, although hepatic sorbitol dehydrogenase activity was not different between the two groups. These results indicate that the sorbitol pathway is significantly activated in cardiac tissue obtained from streptozotocin-induced diabetic rats, which results in the marked cardiac accumulation of fructose.

Aldehyde Reductase↗

PubMed1992

Experimental metastasis of oncogene-transformed NIH 3T3 cells in chick embryo.

By means of a highly sensitive and quantitative assay for specific detection of metastasized tumor cells in chick embryonic organs using the polymerase chain reaction (PCR), we have examined the experimental metastatic ability of individual clones of NIH 3T3 cells, transformed with oncogenes: v-Ki-ras, v-Ha-ras, v-src, v-fos, and v-abl. Such a transformed clone had different metastatic abilities in different embryonic organs. Among them, two clones of NIH 3T3 cells transformed with ras-oncogenes (v-Ki-ras or v-Ha-ras) metastasized to liver and lungs of chick embryo, and grew there more rapidly than the other clones. The parental NIH 3T3 cells were detected as slight bands of PCR products after iv injection, indicating some cells were trapped in chick embryonic organs, but did not grow. These findings indicate that the transformed cells are able to invade the organ tissues and grow in embryonic chick organs, but non-metastatic cells such as the untransformed-NIH 3T3 cells are not able to grow in the secondary sites. These experiments clearly demonstrate the usefulness of this assay system to study genes involved in malignant transformation.

3T3 Cells↗

PubMed1992

Spinal arachnoid cyst in a newborn infant.

A male infant was born with asphyxia following a prolonged breech delivery at 39 weeks of gestation. He had a chylohemothorax from birth. Soon after birth he exhibited flaccid paraplegia with an absence of deep tendon reflexes in the lower extremities. At 17 days of age, magnetic resonance imaging (MRI) disclosed a hypodense area in the thoracic cord between C7 and Th4 in T1-weighted images, and spinal sonography revealed an echo-free space compressing the spinal cord in the same region observed with MRI. A spinal cyst was removed surgically at 24 days of age. The cyst was confirmed by pathology to be a true arachnoid cyst between C7 and Th4. The cause of this cyst may have been a spinal cord injury during the perinatal period.

Arachnoid Cysts↗

PubMed1992

Interstitial hyperthermia of malignant brain tumors by an implant heating system using stereotactic techniques.

Interstitial hyperthermia of malignant brain tumors has been produced by a heated ferromagnetic implant with a low Curie point. Induction heating of the implant, which is stereotactically implanted in a tumor, is obtained by eddy currents in a high-frequency magnetic field. Safe, repeated and long-term treatment of 35 cases of malignant brain tumors has been done using this system. The overall response rate was 31.4%, but the rate for metastatic brain tumors, deep-seated gliomas and others were 50.0, 36.8 and 33.3%, respectively. Deep-seated gliomas were more effectively treated than superficial gliomas by combination with radiation therapy. The common pathological finding was a clearly demarcated coagulative necrosis of ellipsoid shape around the implant.

Brain Neoplasms↗

PubMed1992

Defective insulin response of phosphorylase phosphatase in insulin-resistant humans.

Insulin-stimulated glycogen synthase activity in human muscle is reduced in insulin-resistant subjects. Insulin regulation of human muscle glycogen synthase may require activation of a type-1 protein phosphatase (PP-1). We investigated the change of phosphorylase phosphatase and glycogen synthase activities in muscle biopsies obtained during a 2-h hyperinsulinemic euglycemic clamp in 12 insulin-sensitive (group S) and 8 insulin-resistant (group R) subjects. Fasting phosphorylase phosphatase activity was lower in group R than in group S, and did not increase significantly with insulin infusion in group R until 20 min. In group S, phosphorylase phosphatase was significantly stimulated by 10 min, remaining significantly higher than in group R at all time points. The insulin-mediated changes in phosphatase activities were not decreased by 3 nM okadaic acid but were completely inhibited by 1 microM okadaic acid, thereby verifying that insulin-stimulated phosphorylase phosphatase is accounted for by a PP-1. Subcellular fractionation demonstrated reduced fasting PP-1 activities in both the glycogen and cytosolic fractions of muscle obtained from subjects in group R compared to those in group S. These results suggest that insulin activation of PP-1 could contribute to the stimulation of glycogen synthase by this hormone in human muscle. Lower fasting PP-1 activity in cytosol and glycogen fractions plus lower insulin-stimulated PP-1 activity could explain, in part, reduced insulin-stimulated glycogen synthase in skeletal muscle of insulin-resistant subjects.

Adult↗

PubMed1992

Expression of genes encoding type IV collagen-degrading metalloproteinases and tissue inhibitors of metalloproteinases in various human tumor cells.

Uncontrolled expression of matrix metalloproteinases 2, 3 and 9 (MMP-2, -3 and -9) is believed to be a critical part of the invasive potential of tumor cells because of their ability to degrade type IV collagen, a major structural component of basement membranes. Availability of proteolytic activity in the vicinity of the cell surface is further affected by a local balance between the enzymes and their inhibitors produced by the cell. To determine how frequently deregulated expression of the MMPs and tissue inhibitors of metalloproteinases (TIMPs) is associated with tumor cells, 26 human tumor cell lines were examined by Northern blotting. Transcripts for MMP-2 and MMP-9 were more frequently expressed in mesenchymal tumor cells (9/9 for MMP-2 and 6/9 for MMP-9) than in epithelial tumor cells (4/17 for MMP-2 and 2/17 for MMP-9). Although expression of MMP-2 mRNA was clearly cell type-specific, MMP-9 mRNA expression in mesenchymal cells correlated well with the reported tumorigenicity of the cells. Enhanced expression of MMP-9 mRNA was also associated with the tumorigenic transformation of cells by an activated c-H-ras gene in human embryonic fibroblasts. Only 3 of the 26 tumor cells expressed MMP-3 mRNA, and 2 of the 3 were epithelial tumor cells which coordinately expressed MMP-9 and TIMP-1 mRNAs. TIMP-1 mRNA was almost undetectable in 50% of the tumor cells, but TIMP-2 mRNA was expressed in the majority of the cells. These findings provide comprehensive information about mRNA expression of the MMPs and TIMPs in tumor cells, the deregulation of which is thought to be an integral part of the invasive potential of tumor cells.

Cell Transformation, Neoplastic↗

PubMed1991

Interstitial hyperthermia of malignant brain tumors by implant heating system: clinical experience.

An implant heating system using a ferromagnetic implant with low Curie temperature has been developed for treating human brain tumors. Safe and repeated hyperthermia was possible over periods averaging ten weeks in 23 out of 25 patients with malignant brain tumors without development of major side effects. Evaluation of the effects of this new treatment is still preliminary. Overall response rate was 34.8%. However, five of thirteen cases of malignant glioma and two of five cases of brain metastasis were responded well to interstitial hyperthermia given with or without irradiation. Pathological findings common to the treated tumors were circumscribed, ellipsoid shape of coagulation necrosis around the implant. Degeneration of tumor cells, hemorrhage, vascular stasis and thrombosis were found adjacent to the necrosis. In the future, a combination of interstitial hyperthermia with brachytherapy and chemotherapy may offer improved local control of brain tumor.

Brain Neoplasms↗

PubMed1991

Origins and conducting pathways of motor evoked potentials elicited by transcranial (vertex-hard palate) stimulation in cats.

Spinal cord evoked potentials were elicited in cats by transcranial electrical stimulation with electrodes on the vertex and hard palate. Vertex motor evoked potentials (V-MEP) were also recorded. An extracellular microelectrode recording technique was then used to analyze the results by isopotential mapping. The relationship between the distribution of field potentials and the stimulation polarity was studied using the field potential distribution of the V-MEP in the lower thoracic spinal cord that had been represented on the isopotential maps. The first negative wave of the V-MEP showed maximal amplitude distribution in the anterior funiculus, which corresponds to the extrapyramidal tracts. This pattern was seen with both stimulation polarity arrangements: 1) stimulation with the cathode at the vertex and the anode at the hard palate, and 2) stimulation with the anode at the vertex and the cathode at the hard palate. When the cathode was at the vertex, the stimulation threshold was lower, and the response had higher amplitude than when the anode was at the vertex. Recording V-MEPs elicited by vertex cathode stimulation could provide an excellent method of monitoring the extrapyramidal tracts in cats.

Animals↗

PubMed1991

Vascular responsiveness to various vasoactive substances after exchange transfusion with pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) solution in anesthetized rats.

Vascular responsiveness to various vasoactive substances after exchange transfusion with a modified hemoglobin (pyridoxalated hemoglobin polyxyethylene conjugate; PHP) was examined in anesthetized rats. The hindlimb region of the rat was perfused through the abdominal aorta with autologous blood at a constant flow rate, using a perfusion pump. Perfusion pressure (PP), systemic blood pressure (SBP), and heart rate were measured. Exchange transfusion with a 6% PHP solution (20 ml/kg) was performed and effects of intra-arterial injections of norepinephrine (NE), angiotensin-II (A-II), serotonin (5-HT), acetylcholine (ACh), and nitroglycerin (NG) on PP and SBP were examined. The NE and A-II induced a dose-dependent increase in PP, while ACh and NG induced a decrease in PP. There was no difference in vascular responsiveness to ACh, NG, A-II, and 5-HT before and after exchange transfusion with PHP solution, but NE-induced responses were augmented after exchange transfusion with PHP. Results suggest that the presence of PHP moiety in circulation would not alter vascular responsiveness to ACh, NG, A-II, and 5-HT in a significant manner.

Anesthesia, General↗

PubMed1991

Defective insulin response of cyclic adenosine monophosphate-dependent protein kinase in insulin-resistant humans.

Insulin-stimulated glycogen synthase activity in human muscle correlates with insulin-mediated glucose disposal and is reduced in insulin-resistant subjects. Inhibition of the cyclic AMP-dependent protein kinase (A-kinase) is considered as a possible mechanism of insulin action for glycogen synthase activation. In this study, we investigated the time course of insulin action on human muscle A-kinase activity during a 2-h insulin infusion in 13 insulin-sensitive (group S) and 7 insulin-resistant subjects (group R). Muscle biopsies were obtained from quadriceps femoris muscle at times 0, 10, 20, 40, and 120 min. Insulin infusion resulted in significant inhibition of A-kinase activity at 20 and/or 40 min using 0.2, 0.6, and 1.0 microM cyclic AMP in group S. A-kinase activities both before and after insulin administration were lower in group S than in group R using 0.6 microM cyclic AMP. The decrease in apparent affinity for cyclic AMP during insulin infusion was larger for group S compared with group R. Glycogen synthase activity increased significantly after insulin infusion in both groups and was higher in group S compared with group R. The data suggest that a defective response of A-kinase to insulin in insulin-resistant subjects could contribute to their reduced insulin stimulation of skeletal muscle glycogen synthase.

Adult↗