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Biomedical subjects

K Sako

Publications and source records attributed to K Sako.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Ossified epidural hematomas: report of two cases].

Two cases of ossified epidural hematomas were reported. Patients were nine and twelve year-old boys. Initially they were both followed up conservatively after injuries. Subsequently they were found on CT scan to have calcifications in the capsules of epidural hematomas which were found four months after injury in one case and twelve days after injury in the other. Both underwent craniotomy and histological ossification was found in the capsules of the hematomas. Epidural hematomas in children are known to ossify, and this condition may prevent natural absorption of epidural hematomas. Therefore, careful follow up of hematomas seems to be mandatory on conservative therapy of epidural hematomas in children.

Child↗
PubMed1993

The effects of HA1077, a novel protein kinase inhibitor, on reductions of cerebral blood flow and glucose metabolism following acute and/or chronic bilateral carotid artery ligation in Wistar rats.

The effects of HA1077, a novel protein kinase inhibitor on local cerebral blood flow (LCBF) 2.5 h (acute) after permanent bilateral carotid artery ligation (BCAL) and on LCBF and local cerebral glucose utilisation (LCGU) one week (chronic) after BCAL were studied in conscious Wistar rats. Use was made of quantitative autoradiographic 14C-iodoantipyrine and the 14C-2-deoxyglucose techniques and 24 anatomically discrete regions of the brain. HA1077 (1 or 3 mg/kg) or saline was infused i.v. over a 30 min period. HA1077 significantly increased LCBF after acute BCAL in one of the 23 decreased regions in rats given 1 mg/kg, and in 14 of 23 decreased regions in rats given 3 mg/kg, compared to findings in the saline-treated group. Significant increases in LCBF and LCGU after chronic BCAL were noted in seven of the 13 decreased regions and in four of the 11 decreased regions in rats given 3 mg/kg, as compared to observations in the corresponding saline-treated group, respectively. The LCBF and LCGU reductions in forebrain regions with global ischaemia after acute and/or chronic BCAL were overcome by HA1077. These results suggest that HA1077 may be considered for treatment of subjects with acute and chronic cerebral ischaemia, with impairment in cerebral circulation and/or glucose metabolism.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1993

Local cerebral glucose utilisation following acute and chronic bilateral carotid artery ligation in Wistar rats: relation to changes in local cerebral blood flow.

The effects on local cerebral blood flow (LCBF) and glucose utilisation (LCGU) of permanent, bilateral carotid artery ligation (BCAL) were studied in conscious Wistar rats. LCBF and LCGU were measured using quantitative autoradiographic 14C-iodoantipyrine and the 14C-2-deoxyglucose (14C-DG) techniques in 24 anatomically discrete regions of the brain. LCBF in the cerebral hemispheres 2.5 h (acute) after BCAL significantly decreased to 25-87% of the sham control, with the exception of the mammillary body. After acute BCAL, there was a heterogeneous accumulation of 14C-DG in the caudate nucleus and cerebral cortices. Only in the lateral geniculate body did LCGU significantly decrease after BCAL. One week (chronic) later, LCBF was significantly decreased in 15 (containing the caudate nucleus and all the cerebral cortices) of 24 structures. LCGU in ten (containing the caudate nucleus and all the cerebral cortices) of 24 structures after chronic BCAL significantly decreased to 66-77% of the sham control, except for regions with neuronal damage in which there was a heterogeneous uptake of 14C-DG. The ratio of LCBF/LCGU in chronic BCAL was unchanged in comparison with values in the corresponding sham-operated group. This model of acute and chronic cerebral ischaemia, with impairment in cerebral circulation and/or glucose metabolism, is expected to become a pertinent tool for the neurophysiologist.

Animals↗
PubMed1993

Subacute panencephalitis associated with chronic graft-versus-host disease.

A unique form of subacute panencephalitis developed in a child with aplastic anemia 8 months after an allogeneic bone marrow transplantation (BMT). It was characterized by parenchymal infiltration of CD3 lymphocytes, a marked increase in the number of microglia strongly expressing HLA-DR antigens in both the gray and white matter, and diffuse degeneration of the cerebral white matter. The onset of neurological symptoms coincided with the development of chronic systemic graft-versus-host disease (GVHD). Cellular infiltrates in the CNS lesions were exclusively CD3 lymphocytes intermingled with a small number of monocytes labeled with CD68. There was a preponderance of cells of the CD45RB phenotype. The pathological changes in visceral organs were consistent with those of chronic GVHD. In addition, scrutiny of immunohistochemistry disclosed sparse infiltration of CD3 lymphocytes and diffuse gliosis in the cerebral white matter of another child with chronic GVHD who died 9 months after allogeneic BMT. These cases are suggestive of a potential risk of CNS involvement in GVHD.

Adolescent↗
PubMed1993

Phenotypes of mononuclear cell infiltrates in human central nervous system.

Using a panel of monoclonal antibodies applicable for identification of cell types in paraffin sections, the prevalence of mononuclear cell infiltrates with different phenotypes was estimated in large areas taken from 11 cases of acute and chronic inflammatory diseases in the human central nervous system. The present study clearly demonstrated a diversity of inflammatory mononuclear cell infiltrates, and the dominance of cell types in individual lesions appeared to be determined by both the nature of the diseases and the age of the lesions. The possible pathognomonic significance of a relatively high prevalence of CD4+CD45RO+ lymphocytes in acute rabies and in a convalescent stage of Japanese encephalitis and subacute sclerosing panencephalitis is discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Delivery of a novel nitrosourea, MCNU, to the brain tissue in glioma-bearing rats. Intracarotid versus intravenous infusion.

We observed the tissue delivery of a novel water-soluble nitrosourea, 1-(2-chloroethyl)-3-(methyl-alpha-D-glucopyranos-6-yl)-1-nitros our ea (MCNU) in rats bearing experimental brain tumors by conducting autoradiography on all. Prior to this study, the development of a streaming phenomenon was ascertained (and thus finding the optimum velocity for intra-arterial infusion) by 14C-iodoantipyrine (IAP) autoradiography. Furthermore, a single pass extraction value of MCNU was measured. At an arterial infusion rate of 0.2 ml/min., the streaming phenomenon was recognized but the tracer was fairly evenly distributed at a rate of 1.0 ml/min. On the other hand, the single pass extraction value for MCNU was 0.18 +/- 0.036 (mean +/- S.D., n = 3, under pentobarbital anesthesia). It was suggested that MCNU is very unlikely to be transported into the normal rat brain. We conducted 14C-MCNU autoradiography to observe tissue distribution of MCNU following its intra-arterial and intravenous infusions in a brain tumor model using rats. The normal side (the side where no infusions were given) and the cerebral cortex at the side affected by the tumor (the side where the infusion was given) showed hardly any uptake of 14C-MCNU in both the intra-arterial and intravenous infusion groups. The tumorous section was divided into the periphery and the center to measure tissue concentration of the tracer in each section. Compared against the cortical section, the periphery and the center showed significant increases in the concentration (approximately 11 to 15 times and 3 to 7 times, respectively, the figure for the cortical region) for both the intra-arterial and intravenous groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Sequential change of capillary permeability in the rat brain after surgical removal of an experimental brain tumor.

Experimental brain tumors were excised from rats for sequential observation of changes in local capillary permeability during the postsurgical period. Experimental brain tumor-bearing rats were prepared by stereotaxic transplantation of cultured tumor cells and the resultant tumor was delineated by administration of a dye. Following excision of the stained tumor by craniotomy, sequential changes in local capillary permeability were quantitatively followed-up by autoradiography, using 14C-amino-isobutyric acid as a tracer. Capillary permeability was enhanced following surgery, reaching a maximum both in the extent and degree on the third day. After undergoing a gradual reduction, it showed a marked increase for the second time in a very small area on the 10th postoperative day. A recurrence of the tumor was responsible for this late but marked increase. For a control group, the caudate nucleus was excised from normal rats, followed by observation of the sequential changes in the local capillary permeability. Due to surgical procedure, capillary permeability reached a maximum both in the extent and degree on the 5th postoperative day (slightly later than in the tumor group). This change in capillary permeability was less pronounced than in the tumor group. The difference in the conditions of surgery--tumor excision and partial excision of a normal brain tissue--appeared to explain this difference. The results of this study indicated that it is more desirable to give water-soluble antineoplastic agents early during the postoperative period for chemotherapy of a malignant brain tumor after surgery.

Animals↗
PubMed1993

Effects of fixation and varying target length on the sensitivity of polymerase chain reaction for detection of human T-cell leukemia virus type I proviral DNA in formalin-fixed tissue sections.

In this study, the fixation condition most suitable for maintaining the sensitivity of the polymerase chain reaction (PCR) was investigated by using the alpha-tubulin gene sequence, and the PCR procedure most effective for detecting human T-cell leukemia virus type I (HTLV-I) proviral sequences in fixed, embedded tissues of adult T-cell leukemia patients was explored. First, the sensitivity of the PCR targeting a 286-bp alpha-tubulin sequence was studied in tissue sections fixed in several fixatives for various periods at 25 or 4 degrees C. For histological examination, fixation with 10% buffered formalin at a lower temperature for a shorter period was found to be preferable to retain the sensitivity. And the HTLV-I sequence was detected in only 7 of 18 specimens (38.9%) when the 374-bp sequence of the gag region was targeted, but the rate increased to 77.8% (14 of 18 specimens) when the length of the target sequence was reduced to 120 bp within the same region. Therefore, the one-round PCR targeting a shorter sequence is preferable for application of PCR to archival fixed tissue specimens, the fixation condition of which may not be ideal for DNA preservation.

Base Sequence↗
PubMed1993

DNA breaking activity of the carbon-centered radical generated from 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH).

When supercoiled plasmid DNA was incubated with 2,2'-azobis (2-amidinopropane)hydrochloride (AAPH) at pH 7.4 in the presence and absence of oxygen, the DNA single strands were effectively cleaved. The breaking in the presence of oxygen was not inhibited by superoxide dismutase and catalase, but inhibited by mannitol, ethanol, butyl hydroxyanisole, thiol compounds, tertiary amines and spin trapping agents N-tert-butyl-alpha-phenylnitrone (PBN) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO). The breaking in the absence of oxygen was inhibited by ethanol, a tertiary amine and PBN. By electron spin resonance spin-trapping with PBN, the carbon-centered radical was detected both in the presence and the absence of oxygen. Hydroxyl radical was detected by use of DMPO only in the presence of oxygen. The DNA breaking activity of AAPH was found to be due primarily to the aliphatic carbon-centered radical. While the reactivity of carbon-centered radicals have received little attention, the aliphatic carbon-centered radical generated from AAPH was found to be highly reactive to break the DNA strands.

Amidines↗
PubMed1993

[Effect of intracarotid injection of neuropeptide Y (NPY) on cerebral blood flow in rats and possible application of NPY to the selective drug chemotherapy for brain tumor].

Neuropeptide Y (NPY) was continuously administered to Wistar rats in the normal and glioma bearing conditions intracarotidly via the external carotid artery and local cerebral blood flow (LCBF) was measured by a [14C] iodoantipyrine technique. In the normal rats, the LCBF at the injecting side of NPY markedly reduced in 2 minutes after beginning of drug administration. In glioma-bearing rats, LCBF in the cerebral cortex and caudate nucleus reduced to the same level as normal rats. However reduction of LCBF in the tumor was not significantly different from that of ipsilateral cortex and caudate nucleus. The results of this study suggest that flow moduration by NPY injection increases delivery of intra-carotid administered anticancer drugs to the brain tumor with concomitant decrease of neurotoxicity to the normal brain.

Animals↗
PubMed1993

[Surgical removal of lateral pontine cavernous angioma: review of the surgically treated cases in the literature].

A case of cavernous angioma of the pons which was surgically and successfully excised was reported. A 36 year-old man complained of progressive headache, double vision and tinnitus. Neurologic examination revealed left fifth, sixth and seventh cranial nerve palsies. He had left limb ataxia and right sided hemisensory deficit. A computed tomographic (CT) scan on admission disclosed a hematoma in the left lateral portion of the pons. Serial CT scans demonstrated progressive increase of hematoma. MRI scans revealed an area of mixed signal intensity in T1 weighted images. These findings were thought to be consistent with a cavernous angioma. Three months after the onset, surgery was performed using a lateral suboccipital approach. Histological examination disclosed cavernous angioma. After surgery, the patient's neurological deficits improved, and after 3 months, all symptoms except the mild limb ataxia had disappeared.

Brain↗
PubMed1992

Effects of intracarotid infusion of neuropeptide Y on cerebral blood flow in rats.

Neuropeptide Y (NPY) was continuously administered to Wistar rats intracarotidly via the external carotid artery and local cerebral blood flow (LCBF) was measured by a quantitative autoradiography using [14C]iodoantipyrine. A remarkable reduction in LCBF was observed in the NPY infused hemisphere. This depression was irregular and was particularly evident in the hippocampus, selective thalamic nuclei and the cerebral cortex.

Animals↗
PubMed1992

Cerebral blood flow and histopathological changes following permanent bilateral carotid artery ligation in Wistar rats.

Cerebral blood flow and histopathological changes after bilateral carotid artery ligation (BCAL) in Wistar rats were studied. Eight of the 38 rats (21%) died within one week. In the 30 survivors, the incidence of histopathological change was 90% in the caudate nucleus, 23% in the cortex, 30% in the hippocampus, and 0% in the other structures. Local cerebral blood flow (LCBF) was measured using the quantitative autoradiographic 14C-iodoantipyrine technique in 24 anatomically discrete regions of the brain. BCAL induced ischemia in the entire forebrain. The percent reduction of LCBF was between 25-94% of the control at 2.5 h after BCAL. LCBF tended to recover 1 week after BCAL except for the regions of neuronal damage. These results suggest that neuronal damage does not correlate with the flow rate. In the present study, selective neuronal damage was also observed in rats with chronic cerebral ischemia.

Animals↗
PubMed1992

Results of surgical resection of pulmonary metastases of squamous cell carcinoma of the head and neck.

In this retrospective review of 58 patients (12 females and 46 males) with pulmonary metastases of squamous cell carcinoma of the head and neck treated between January 1, 1970, and December 31, 1989, we evaluated their clinical courses and analyzed the outcomes of those who underwent pulmonary resection. For the entire group of patients, factors predictive of survival in those patients with a diagnosis of pulmonary metastases included pulmonary resection of metastases (p = 0.0001), locoregional control of the head and neck primary tumor at the time of diagnosis of pulmonary metastases (p = 0.007), TNM stage of the head and neck primary tumor (p = 0.02), a single nodule seen on the chest radiograph (p = 0.02), and disease-free interval (DFI) from the primary tumor of the head and neck of 2 years or more (p = 0.05). Twenty-four of 58 patients underwent thoracotomy for resection of metastases. Four (17%) were found to have a second primary tumor of the lung. Of the 20 remaining patients who underwent explorative surgery for possible pulmonary resection, 18 (90%) underwent complete resection of all malignant disease with an estimated 5-year survival of 29%. In these patients, a DFI of less than 1 year was associated with a 5-year survival rate of 0%, whereas a DFI of 1 to 2 years was associated with a 5-year survival rate of 43% and a DFI of 2 years or longer had a 5-year survival rate of 33%. The number of malignant pulmonary nodules that were resected ranged from one to five and was not significant in predicting survival (p = 0.19). Of eight patients who underwent the resection of more than one malignant pulmonary nodule, 50% survived 2 years, but none survived 5 years. Resection of a solitary pulmonary metastasis from squamous cell carcinoma of the head and neck resulted in long-term survival in selected patients. Important prognostic factors included locoregional control of the head and neck primary tumor, the number of nodules seen on chest radiograph, the TNM stage of the primary tumor, and the DFI from the head and neck primary tumor. The value of resection in patients with more than one malignant pulmonary nodule remains to be defined for this group of patients.

Carcinoma, Squamous Cell↗
PubMed1992

The effects of oxiracetam (CT-848) on local cerebral glucose utilization after focal cerebral ischemia in rats.

The effects of oxiracetam on the reduction of brain metabolism induced by focal cerebral ischemia were investigated by measuring local cerebral glucose utilization (LCGU) in rats 24 hr after left middle cerebral artery occlusion. Focal cerebral ischemia reduced LCGU in the entire ipsilateral cortex, the greatest reduction being in the lateral parts of the frontoparietal cortex. LCGU was slightly reduced in the contralateral cortex; this reduction was considered to be caused by diaschisis. Oxiracetam was administered intraperitoneally for 3 days prior to middle cerebral artery occlusion. In the ipsilateral cortex, LCGU reduction was minimized in the ischemic center areas by oxiracetam at a dose of 400 mg/kg and in more extensive areas, by a dose of 800 mg/kg. Moreover, oxiracetam at a dose of 800 mg/kg enhanced metabolism impaired by diaschisis in the caudal areas of the contralateral cortex. These findings suggest that oxiracetam minimizes the reduction of brain function induced by ischemia and may therefore be useful in the treatment of cerebrovascular disease.

Animals↗
PubMed1992

Lipoma involving the skull. Case report.

The case of an intraosseous lipoma involving the left frontal bone is reported. Lipomas of the bone are rare; only three cases of lipomas involving the skull have previously been reported. The differential diagnosis includes a healing bone infarction or fracture, meningioma, hemangioma, and fibrous dysplasia. Diagnosis prior to surgery is difficult.

Adult↗