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Biomedical subjects

M Kobari

Publications and source records attributed to M Kobari.

At least 55 records · Page 3Linked to original sources
PubMed1997

Cerebral hemodynamics in patients with moyamoya disease and in patients with atherosclerotic occlusion of the major cerebral arterial trunks.

To determine the difference in cerebral hemodynamics between Moyamoya disease and atherosclerotic occlusion of the major cerebral arterial trunks, we measured local cerebral blood flow (CBF) and local CO2 reactivity (CO2R) by xenon-enhanced computed tomography (CT). A total of 11 adult patients with Moyamoya disease (mean age, 39.6 +/- 7.8 years) and eight patients with atherosclerotic occlusion of the major arterial trunks (mean age, 62.4 +/- 15.4 years) were studied. Regions of interest were frontal, temporal and occipital cortex, caudate, putamen and thalamus in each hemisphere. In patients with Moyamoya disease, local CBF values in the internal carotid artery territory (frontal and temporal cortex, caudate, putamen) were significantly higher than those in the occluded side of patients with atherosclerotic occlusion. Local CO2R values in the caudate and putamen were significantly higher than those in the occluded side of patients with atherosclerotic occlusion. These results suggest that the cerebral hemodynamics of Moyamoya disease differ from those of atherosclerotic occlusion of the major cerebral arterial trunks, and may be a result of the abundant collateral circulation through basal 'Moyamoya' vessels.

Adult↗
PubMed1997

Familial idiopathic brain calcification with autosomal dominant inheritance.

We report a family with brain calcification, predominantly in the basal ganglia, and no evident cause such as abnormal calcium or phosphorus metabolism. The proband, a 48-year-old man, had intellectual decline, parkinsonism, and mild cerebellar ataxia. He had bilateral and symmetric calcification of the basal ganglia, thalamus, dentate nucleus, cerebral cortex, subcortical white matter, and hippocampus on CT. Calcified areas showed low- or high-intensity signals on MRI T1-weighted images, and low-intensity signals on MRI T2-weighted images. Two sons and both parents, all asymptomatic, also showed calcification of the basal ganglia, suggesting an autosomal dominant inheritance. Familial idiopathic brain calcification is a rare disorder with less than 20 previously reported families. Twelve families with autosomal dominant inheritance showed a relatively homogeneous clinical picture, which may represent a distinct clinical entity. Mental deterioration, parkinsonism, and cerebellar ataxia appear in adult life and progress gradually. CT imaging, rather than MRI, is a simple and useful means to screen family members for this condition.

Brain Diseases↗
PubMed1997

[Clinical features of 5 cases of tuberculous meningitis--with special reference to brain CT and MRI findings].

We evaluated the clinical features of 5 cases of tuberculous meningitis who had been admitted to our department from 1987 to 1994. Three patients were male and two were female. Their age ranged from 17 to 74 years old. All cases were examined by both CT and MRI before and during antituberculous treatment. Before the treatment, CT scan revealed abnormal findings such as nodular lesion suggesting tuberculoma, subarachnoid contrast enhancement or cerebral infarction in 2 cases, while MRI revealed abnormal findings such as inflammatory lesions with Gd-enhancement in 4 out of 5 patients. During the treatment, all abnormal findings except cerebral infarction disappeared. No abnormal findings were detected by CT. MRI and SPECT in one case who showed right hemiparesis and motor aphasia. In summary, CT scan could demonstrate abnormal findings in only a small portion of patients with tuberculous meningitis. One the other hand, MRI revealed various abnormal findings in most patients, and could reveal some lesions which could be responsible for the symptoms of patients. In a few patients, however, MRI could not show any lesion in spite of obvious focal neurological signs. MRI is considered to be useful for detecting the lesions in most patients with tuberculous meningitis, although its findings are not always specific for the disease.

Adolescent↗
PubMed1997

[Intraoperative radiotherapy in carcinoma of the body and tail of the pancreas].

The prognosis for patients with carcinoma of the body and tail of the pancreas is extremely poor. We analyzed the effectiveness of intraoperative radiotherapy (IOR) from the viewpoint of the cumulative survival rate and pain relief. The prognosis of patients who underwent IOR with/without resection was significantly longer than for patients without IOR (p < 0.0001). Better pain relief was obtained by IOR. Although a randomized prospective study is required, resection and IOR will be the central treatment modalities for carcinoma of the body and tail of the pancreas.

Aged↗
PubMed1997

[Myotonic dystrophy with marked megacolon: report of a case].

A 45-year-old woman was incidentally suspected to have megacolon. Chest X-rays showed elevated left diaphragm due to colonic gas, and the heart was deviated to the midline. Barium enema revealed marked dilation of the sigmoid colon, confirming the diagnosis of megacolon. Maximal diameter of the sigmoid colon was 23 cm, but she had no gastrointestinal symptoms. During the work up for megacolon, the presence of myotonic dystrophy was suspected. She had hatchet face, but was not bald. Muscles of the neck and extremities were slightly atrophic. There was percussion myotonia of the tongue and both hands, and grip myotonia of the hands. Laboratory examinations showed impaired glucose tolerance and low level of serum IgG. EMG showed myotonic discharges and myopathic units in the limbs. Brain CT imaging revealed a thick skull. Cases of myotonic dystrophy associated with marked megacolon are rare in Japan. Megacolon presents a high risk for ileus, volvulus, and rupture, and myotonic dystrophy is associated with a high operative and anesthesic risk. Megacolon, therefore, is an important complication to look for in the management of myotonic dystrophy.

Female↗
PubMed1996

Intravascular substance P dilates cerebral parenchymal vessels through a specific tachykinin NK1 receptor in cats.

The role of substance P in the cerebral parenchymal circulation was examined in 19 anesthetized cats. The local cerebral blood volume in the temporoparietal cortex was measured by our photoelectric method. Cerebral blood volume reflects the cumulative dimensions of the parenchymal microvessels. Intravenous injection of 0.01, 0.1, and 1 mg/kg FK888 (N2-[(4R)-4-hydroxy-1-(1-methyl-1H-indol-3-yl) carbonyl-L-prolyl]-N-methyl-N-phenylmethyl-3-(2-naphthyl)-L-alaninamide) , a selective tachykinin NK1 receptor antagonist, had no significant effects (compared to the vehicle, ethanol) on cerebral blood volume and mean arterial blood pressure. Intracarotid injection of 1, 10, 100 pmol/kg, and 1 nmol/kg substance P increased cerebral blood volume (P < 0.01) in a dose-dependent manner (maximal increase of 6.5% at 5 min). Following injection of 1 nmol/kg substance P, cerebral blood volume was initially reduced, possibly due to the marked fall in mean arterial blood pressure (P < 0.01). The cerebral blood volume increase elicited by 1 nmol/kg substance P was strongly blocked (P < 0.05) by prior injection of 1 mg/kg FK888. However, the depressor effect of 1 nmol/kg substance P (-24 +/- 4 mm Hg at 30 s, P < 0.01) was partially inhibited (P < 0.01) by FK888. We conclude that endogenous substance P may not have a significant role in the maintenance of resting tone of cerebral parenchymal vessels. Intravascular substance P, however, dilates the small microvessels through a specific tachykinin NK1 receptor and could be involved in the development of pathologic processes such as migraine headache.

Animals↗
PubMed1996

Establishment of an experimental liver metastasis model by intraportal injection of a newly derived human pancreatic cancer cell line (KLM-1).

CONCLUSION: It is suggested that this liver metastasis model formed by a highly metastatic variant (KLM-1) is valuable for the study of the liver metastatic processes of human pancreatic cancer. BACKGROUND: Liver metastasis in the early postoperative period is one of the causes for the poor prognosis of patients with resected pancreatic cancer. Therefore, it is necessary to establish an experimental model to study the mechanisms of liver metastasis in pancreatic cancer. METHODS: Human pancreatic cancer cell lines (PK-1, PK-9, and KLM-1) were injected into the portal vein of nude mice with or without pretreatment with antiasialo GM1, and colonies of liver metastases were counted for comparison of metastatic ability of these cell lines. Biological and histopathological characteristics of the highly liver metastatic cell line (KLM-1) were compared with its parent cell line (PK-1). RESULTS: PK-1 cells and PK-9 cells rarely formed liver metastasis foci, but pretreatment with antiasialo GM1 promoted liver metastasis. KLM-1 cells formed liver metastases at the rate of 70% even without antiasialo GM1 pretreatment. KLM-1 cells had such biological characteristics as short doubling time, short lag phase, and resistance to NK cytotoxicity. After intraportal injection of 125I-labeled KLM-1 cells, radioactivity as well as micrometastases were detected in the liver at 72 h.

Animals↗
PubMed1996

Local cerebral blood flow in motor neuron disease: correlation with clinical findings.

Local cerebral blood flow (CBF) measured by xenon-enhanced CT was correlated with the clinical findings in 21 patients with motor neuron disease (mean +/- SD age, 60 +/- 10 years). In 11 patients, CBF was also measured after intravenous injection of 2 mg thyrotropin releasing hormone (TRH). There were no significant differences in CBF of the cerebral cortex, basal ganglia, thalamus, and subcortical white matter with respect to age, duration of illness, or presence (n = 9) or absence (n = 12) of bulbar palsy. In patients with upper motor neuron disturbance (n = 10), however, local CBF in the frontal cortex was significantly lower (p < 0.05) than in those without it (n = 11). Within the frontal cortex, CBF reduction was marked in the upper posterolateral part (p < 0.05) that included the motor and premotor areas. Intravenous administration of TRH did not significantly alter the local CBF in any of the brain regions examined. An additional patient with motor neuron disease and severe dementia showed marked CBF reduction in the frontal lobe, which was in common with but much greater than the reduction in those exhibiting subcortical dementia (e.g., progressive supranuclear palsy). We conclude that in motor neuron disease patients with upper motor neuron involvement, the selective reduction of CBF in brain regions that include primary motor and premotor areas may reflect functional disturbance or neuronal degeneration in these regions. The ameliorating effect of TRH in patients with motor neuron disease, if any, appears not to be related to increases in local CBF or activation of brain function.

Aged↗
PubMed1996

Analysis of the derangement of the pancreatic microcirculation in a rat caerulein pancreatitis model using an intravital microscope system.

In order to clarify the derangement of the pancreatic microcirculation in acute pancreatitis, the pancreatic microcirculation in caerulein pancreatitis was monitored intravitally and the roles of bradykinin and nitric oxide were examined using bradkykinin B2 receptor antagonist, HOE140. Under an intravital microscope, the pancreatic microcirculation was observed 2 or 6 hr after the induction of acute pancreatitis. HOE140 was administered 30 min before the induction of acute pancreatitis. The videoimages were taken into the computer, and the value of grayscale was measured with imaging software to quantify the degree of extravasation. Extravasation in the postcapillary venules was remarkable and the velocity in pancreatic terminal arterioles decreased significantly. However, the adherence of leukocytes was not observed until 6 hr after the induction. Both the extension of extravasation and the decrease of velocity were prevented by HOE140. The levels of nitric oxides in the pancreatic tissue declined and this decline was not influenced by HOE140. Bradykinin participates mainly in the regulation of vascular permeability in the early stage of caerulein pancreatitis. Further, the impairment of pancreatic microcirculation may play a key role in the onset and development of acute pancreatitis.

Acute Disease↗
PubMed1996

Swift transformation and locomotion of polymorphonuclear leukocytes and microglia as observed by VEC-DIC microscopy (video microscopy).

The detailed assembly used by us for video-enhanced contrast-differential interference contrast (VEC-DIC) microscopy (video microscopy is first described. Employing such video microscopy, we then examined the morphological changes occurring during locomotion and activation processes of polymorphonuclear leukocytes (PMNL) and microglia at an almost electron microscopic magnification. Upon contacting the substratum, PMNL transformed into a polarized ameboid shape and crawled extending pseudopodia, as has been well documented previously. The PMNL sometimes displayed a peculiar locomotion as if they were stepping on "tiny legs", or sliding on a treadmill of cell membrane. Cultured microglia were observed to exist in 4 forms; ramified, reactive, villous, and ameboid. Microglia in the reactive form pivoted, circled and crawled on the astroglial cell layer using their transparent lamellipodia with no morphological changes in their cell body. Unlike PMNL, reactive microglia exhibited no agitated movements of their intracellular organelles, including granules and cytosol, during locomotion. Lamellipodia on the undersurface of the cell body touching the cell layer adhesively, appeared to serve as the locomotive apparatus. When activated, both floating PMNL and microglia of villous form assumed an ameboid shape within a few seconds. Microglia occasionally swam in the medium waving their lamellipodia towards a target object (e.g. zymosan A particles), remodelling to an amorphous ameboid form and covering up the target. We attempt to discuss such swift morphological changes from the standpoint of thermodynamic potential of Gibbs free energy which is stored within the cells.

Cell Movement↗
PubMed1996

Usefulness of Japanese staging in the prognosis of patients treated operatively for adenocarcinoma of the head of the pancreas.

BACKGROUND: Differences in the clinical staging in Japan from that of the Union Internationale Contre le Cancer (UICC) staging system may account for discrepancies in the prognosis of carcinoma of the pancreas between Japan and the United States of America. STUDY DESIGN: This study compares the usefulness of Japanese staging with the UICC staging in 1,689 patients who underwent resection for carcinoma of the pancreatic head registered with the Japan Pancreas Society. RESULTS: The survival rate was correlated with the Japanese stage classification. The survival rate of patients with T4 tumors was surprisingly better than for those with T2 or T3 tumors. The extent of lymph node involvement and of extrapancreatic tissue invasion reflected the prognosis. The UICC staging system did not reflect differences in prognosis among the four stages, especially between stages II and III. CONCLUSIONS: To establish a more practical and universal staging system for carcinoma of the pancreas, the Japanese system may offer improvements in predicting the prognosis of American or European patients with this disease.

Adenocarcinoma↗
PubMed1996

Aspirin improves the enhanced erythrocyte aggregability in patients with cerebral infarction.

We examined the effect of aspirin on the enhanced erythrocyte aggregability in 19 patients with cerebral infarction during the chronic phase. Aspirin (81 mg/day) was administered for 8 weeks. The rate of erythrocyte aggregation (aggregability) was measured using the whole-blood erythrocyte aggregometer developed by us (Am. J. Physiol. 251, H1205-H1210, 1986) before, and at 4 and 8 weeks after initiation of the aspirin administration. Concomitant measurements were made of certain blood factors such as the hematocrit, albumin-globulin (A/G) ratio and fibrinogen concentration. The erythrocyte aggregation rates before, and at 4 and 8 weeks were 0.154 +/- 0.019/s, 0.144 +/- 0.020/s, and 0.143 +/- 0.020/s, respectively. The erythrocyte aggregation rates at 4 and 8 weeks were significantly (P < 0.05, Bonferroni's modified t-test) lower than that before aspirin administration. Although the hematocrit value and A/G ratio were not changed at 4 and 8 weeks after the initiation of aspirin, the concentration of fibrinogen were significantly (P < 0.05) reduced at 4 weeks. The above results suggest that aspirin can improve the enhanced erythrocyte aggregability in patients with cerebral infarction during the chronic phase.

Adult↗
PubMed1996

-Clinical features of 10 cases of tuberculous meningitis--with special reference to patient's delay and doctor's delay.

We retrospectively evaluated the clinical findings of 10 cases of tuberculous meningitis who had been admitted to our department from 1987 to 1994. Four patients were male and six were female. All of them were Japanese, and their age ranged from 17 to 74 years old. Regarding the patient's delay, nine patients visited a doctor in 1 to 20 days after the onset of headache, and one patient visited a doctor in 14 days after the onset of general malaise. It is suggested that the patient's delay could not be longer than 3 weeks because of progressively worsening symptoms of tuberculous meningitis such as severe headache and fever. The time interval between the first contact of the patient to a doctor and the commencement of antituberculous therapy (doctor's delay), ranged from 14 to 66 days. When the diagnosis of meningitis was obtained based on the findings of the cerebrospinal fluid (CSF), focal neurological signs including psychological symptoms, cranial nerve palsies and seizure were noted besides meningeal signs or the disturbance of consciousness in 4 patients. The CSF revealed an increase in cell counts with mononuclear cell dominance in 9 patients, but the findings typical for tuberculous meningitis such as increase in total protein content and a decrease in glucose concentration were obtained in only 5 patients. Mycobacterium tuberculosis had not been detected in all cases when the antituberculous chemotherapy was started. Later, it was found to be positive in the CSF sample from only three patients by culture or polymerase chain reaction (PCR) method. When the antituberculous therapy was completed, meningitis was cured without remaining any symptom or sign in all patients. All patients had no active pulmonary tuberculosis when the meningitis was diagnosed, and only one of them had sequels of lung tuberculosis. Four patients had the past history of tuberculosis, and 1 had the familial history of pulmonary tuberculosis. At the first contact to a doctor, seven patients were diagnosed as having common cold or headache related with fever because of the lack of typical signs of meningitis. Similarly three other patients were initially diagnosed as having meningitis due to viral infection or unknown etiology. In summary, it was difficult to obtain the solid diagnosis of tuberculous meningitis at the initial stage of this disease, since the symptoms and signs at its onset often similar to those of common cold or non-specific headache. Therefore, when we see the patients with subacute onset of headache and fever followed by the meningeal signs, tuberculous meningitis should always be included in the list of diseases requiring differential diagnosis. In addition, when tuberculous meningitis is suspected, the antituberculous therapy should be started without any delay.

Adolescent↗
PubMed1996

[The role of screening for carcinoma of the pancreas].

We discussed the possibility of the screening programs for the early detection in carcinoma of the pancreas. Several trials of screening have been conducted for the outpatients with diabetes mellitus, jaundice or upper abdominal pain by means of serum erastase-1, amylase and CA19-9 levels and the ultrasonography. The trials could detect 37 patients of 4250 (1.3%), 47 of 423,905 (0.011%) and 89 of 3585 (2.4%) with carcinoma of the pancreas. Despite effective screening program is not available, the screening carries the potential for improvement of the resectability and the mortality in the patients with carcinoma of the pancreas.

Biomarkers, Tumor↗
PubMed1995

Calcitonin gene-related peptide (CGRP) and the regulation of cerebral parenchymal vessels.

The role of calcitonin gene-related peptide (CGRP) in the cerebral microcirculation was examined in fourteen anesthetized cats. The local cerebral blood volume (CBV) and blood flow (CBF) in the temporoparietal cortex were measured by our photoelectric method. CBV represents the cumulative dimensions of the parenchymal vascular network. Intracarotid injection of 0.1, 1, and 10 micrograms/kg CGRP8-37, a CGRP antagonist, had no significant effects on CBV and mean arterial blood pressure (MABP). Intracarotid injection of 0.1 and 1 microgram/kg CGRP, but not 0.01 microgram/kg CGRP, increased CBV in a dose-dependent manner (P < 0.05). CBV was initially reduced following 1 microgram/kg CGRP injection, possibly reflecting the marked fall in MABP (P < 0.01) with this dose. Following injection of 0.1 and 1 microgram/kg CGRP, CBF was also increased by +7.3 +/- 7.7 (+10.7%) and +13.1 +/- 4.8 ml/100 g brain/min (+20.4%, P < 0.05) at 15 min. The CBV increase elicited by 1 micrograms/kg CGRP was inhibited (P < 0.05) by preinjection of 10 micrograms/kg CGRP8-37. It is concluded that CGRP has no significant role in the maintenance of resting tone of intracerebral microvessels. However, circulating CGRP dilates the small parenchymal vessels through a specific CGRP receptor, and thereby is involved in the evolution of pathologic conditions.

Animals↗