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Biomedical subjects

K Harada

Publications and source records attributed to K Harada.

At least 937 records · Page 52Linked to original sources
PubMed1989

Endoscopic diagnosis of minute, small, and flat early gastric cancers.

We reviewed the diagnostic process in 6 minute, 6 small and 9 flat early cancers detected preoperatively, and in additional 12 flat cancers that were found in resected stomachs only at histology between 1976 and 1986. The limit of the size of cancer detectable preoperatively was 4 mm. Endoscopically, 7 out of 12 minute and small cancers detected preoperatively showed obvious morphological changes, while the others showed only color changes with or without erosion. Lesions with morphological changes significantly invaded the mucosa more often than those with no such changes (p = 0.010). Among flat cancers, color change was significantly more frequently observed in cancers involving the whole mucosa than in those confined to the superficial part of the mucosa (p = 0.015). Redness and discoloration were significantly more frequent in the differentiated and undifferentiated groups, respectively (p = 0.005). This study suggests that morphological and color changes are important indicators of minute or small cancers, especially those involving the whole mucosa.

Adult↗
PubMed1989

Regional dynamics of N-isopropyl-(123I)p-iodoamphetamine in human brain.

Regional cerebral dynamics of N-isopropyl-(123I)p-iodoamphetamine (IMP) in the human brain were studied using a multi-detector single photon emission computed tomography (SPECT) scanner in 35 subjects both normal and with a variety of neurological conditions. Distribution of IMP in the brain was also compared with regional cerebral blood flow (CBF) measured by positron emission tomography (PET) in 15 of these 35 cases. A significant regional difference in temporal changes of radioactivity was observed among normal brain structures. A rapid increase with early washout of the tracer was shown in the cerebellum and the occipital cortex, while the basal ganglia revealed a relatively slow increase and prolonged retention, indicating the regional difference in extraction and/or retention of IMP among the cerebral tissues. In cases with unilateral hypoperfusion, the percentage of the activity in the lesion to that in the contralateral normal cortex on the early SPECT was correlated well with that on CBF measured by PET (r = 0.870, p less than 0.001). However, the contrast on the SPECT image decreased with time after injection; 84.0 +/- 7.4% on the SPECT at 5-20 min scan, 87.6 +/- 7.6% at 35-50 min scan and 96.2 +/- 6.3% at 5 hr scan. In a case with a brain tumor having high blood flow documented by PET, increased accumulation of IMP was observed in the tumor on the early images obtained within 20 min followed by a rapid washout. These findings suggested altered extraction and/or retention of IMP in normal and diseased tissues, and these factors should be considered for the assessment of distribution and redistribution of IMP.

Alzheimer Disease↗
PubMed1989

[A case of mediastinal immature teratoma with elevated levels of CA19-9].

A 15-year-old woman was found to have a large anterior mediastinal mass on chest roentgenogram. Preoperatively, serum levels of CA19-9 were found to be elevated. From the result of pathological study on the resected lesion, it was diagnosed as immature teratoma. The fluid levels of CA19-9 extracted from the tumor were found to be elevated. Part of the tumor, the pancreas, the bronchial epithelium and the intestinal epithelium, were shown positive staining in immunoperoxidase assay using anti CA19-9 antibody. The postoperative course was satisfactory and the serum levels of CA19-9 returned to normal. In mediastinal germ cells tumors, there are no cases reported in which CA19-9 was detected in serum and in the tumors. In order to define the relation between mediastinal germ cell tumors and CA19-9, further more cases should be investigated.

Adolescent↗
PubMed1988

Role of the nucleus of the optic tract of monkeys in optokinetic nystagmus and optokinetic after-nystagmus.

A previous experiment disclosed that unilateral lesions of the nucleus of the optic tract (NOT) in the fascicularis monkey resulted in selective loss of optokinetic nystagmus (OKN) towards the lesioned side. This may suggest that the NOT in monkeys, as in non-primates, represents the first relay station in the basic horizontal optokinetic path. This monkey, however, did not show a rapid rise in OKN velocity in response to steps in stimulus velocity. In the present experiments, effects of NOT lesions upon both the rapid and the slow rise of OKN as well as optokinetic after-nystagmus (OKAN) were examined in 6 fuscata monkeys. In 3 with total NOT lesions of 6 monkeys, none of the slow rise OKN or OKAN slow phase velocity were produced towards the lesioned side. In one of the remaining 3 monkeys with partial NOT lesions, a slow rise OKN and OKAN slow phase velocity were selectively reduced towards the lesioned side. In 2 of these 4 monkeys whose lesions were localized in the lateral portions of the pretectum, rapid rise in OKN velocity remained unchanged, whereas in the remaining two whose lesions were large enough to extend into the medial portions of the pretectum near the nucleus of the posterior commissure, rapid rise in OKN velocity was reduced. In the remaining 2 monkeys whose NOT was only superficially damaged, all components of OKN were normal. Other visually induced eye movements were normal. In all monkeys except for one who had marked spontaneous nystagmus, the peak velocity of vestibular nystagmus was not affected after NOT lesions. These findings indicate that the dynamics of the charge of the velocity storage mechanism is separately influenced by NOT lesions: OKN and OKAN are abolished, but vestibular nystagmus remains unaffected.

Animals↗
PubMed1988

Analysis and purification of toxic peptides from cyanobacteria by reversed-phase high-performance liquid chromatography.

A simple, rapid and reliable chemical analysis method for microcystins (cyanoginosins) has been studied. Three different mobile phases for high-performance liquid chromatography were selected and optimized. Also the adsorptive powers of three commercially available C18 cartridges were compared and the results successfully applied to the clean up of three of the toxins. Finally a total system for the analysis and isolation of microcystins was established.

Chromatography, High Pressure Liquid↗
PubMed1988

Effects of halothane and calcium entry blockers on atrioventricular conduction-a comparative study of verapamil, diltiazem, and nifedipine.

The effects of halothane on AV nodal function were evaluated in dogs with verapamil, diltiazem, or nifedipine during atrial pacing using the technique of His-bundle electrocardiography. Fifty-one mongrel dogs were divided into six groups. Anesthesia was induced with ketamine 100 mg im. and thiamylal 25 mg/kg iv. The animals were intubated and mechanically ventilated at normocapneic levels. Anesthesia was maintained with 50% nitrous-oxide in oxygen with pancuronium 2 mg im. Dogs in groups I, III, and V were anesthetized with 0.8% halothane and 50% nitrous-oxide in oxygen. We observed interactions between halothane and intravenous administration of either verapamil 0.1 mg/kg, diltiazem 0.15 mg/kg, or nifedipine 0.01 mg/kg respectively. Dogs in groups II, IV, and VI were administered either verapamil, diltiazem, or nifedipine iv without halothane. There were prolongations of sinus cycle length (SCL) (414 +/- 10 to 542 +/- 19 msec.), atrium-His (AH) interval (73 +/- 3 to 97 +/- 5 msec.), and functional refractory period (FRP) of the AV-node (227 +/- 5 to 260 +/- 5 msec.) in halothane anesthesia in groups I, III, and V. There were more prolongations of these variables after iv administration of verapamil (SCL; 617 +/- 35, AH; 118 +/- 7, FRP of the AV node; 311 +/- 4) and diltiazem (SCL; 554 +/- 19, AH; 118 +/- 12, FRP of the AV node; 283 +/- 12) but no prolongations after nifedipine (SCL; 533 +/- 19, AH; 99 +/- 8, FRP of the AV node; 272 +/- 9). Comparing effects of calcium entry blockers with and without halothane in groups I and II, III and IV, or V and VI, there were additive depressing effects of halothane with either verapamil or diltiazem on AV nodal function. And there is a difference between the effects of nifedipine on SCL with and without halothane.

Journal Article↗
PubMed1988

Rapidly growing mature teratoma of the mediastinum: do sex hormones affect growth of the tumor?

The case of a 12-year-old girl with an anterior mediastinal tumor is reported. A mass grew rapidly and occupied the anterior mediastinum after menarche. Resected material was diagnosed as a mature teratoma. Both estrogen receptors and progesterone receptors were detected in the resected tissue. The titer of estrogen receptors was 2-11.3 femtomoles per milligram of protein and that of progesterone receptors was 9.5-15.7 fmol/mg protein. Based on these data, it was surmised that sex hormones may affect the growth of the tumor in this case. The change in sex hormones after menarche may have played a role in the rapid growth of this tumor.

Child↗
PubMed1988

Gallium scintigraphy in patients with adult T-cell leukemia lymphoma.

Gallium scintigraphy was evaluated in 25 patients with adult T-cell leukemia lymphoma (ATLL). Anterior and posterior images were obtained at 72 h after administration of 3 mCi 67Ga-citrate using a gamma camera (Maxi-Camera 400 T, General Electric Co.) with a medium energy standard parallel hole collimator. Abnormally high accumulations were observed in 17 out of 25 cases (superficial lymph node, 8; hilar and mediastinal lymph node, 7; paraaortic lymph node, 2; lung, 9; liver, 1; bone, 1). There were 10 malignant lesions detected by 67Ga scintigraphy in 9 out of 17 cases (superficial lymph node, 1; hilar and mediastinal lymph node, 6; paraaortic lymph node, 1; liver, 1; bone, 1). White blood cell count and serum LDH levels were raised in patients with abnormally high accumulations of 67Ga. In conclusion, 67Ga scintigraphy seemed to be a useful examination to detect malignant lesions in patients with ATLL.

Female↗
PubMed1988

Cerebral circulation and oxygen metabolism in moyamoya disease of ischemic type in children.

Cerebral rCBF, rOEF, rCMRO2, and rCBV in moyamoya disease were studied by means of positron emmission tomography (PET), using 15O as a tracer. Steady-state methods with C15O2 and 15O2 were used to obtain the functional images of rCBF, rCMRO2, and rOEF. The 15O single-inhalation method was used to obtain the rCBV image. Five children (two boys and three girls) with mean age of 11 years and eight normal volunteers with mean age of 31 years were included in the study. The symptoms of moyamoya disease were due to cerebral ischemia, such as transient ischemic attack (TIA), reversible ischemic neurological deficit (RIND), and minor stroke. The interval between the latest ictus and PET scan ranged from 3 days to 3 years 6 months. Physiological parameters (rCBF, rCMRO2 etc.) in cerebral gray matter, cerebral white matter and basal ganglia were calculated from the single functional images. Any, low density areas appearing in X-ray-CT performed just prior to the PET study were carefully excluded from the analysis. The parameters of moyamoya disease were statistically compared with normal control parameters. Though the value of rCBF was slightly higher in moyamoya disease, this difference was not statistically significant. On the other hand, in moyamoya disease rCBV increased significantly in gray matter, white matter, and basal ganglia. The ratio of CBF to CBV is considered to be the index of perfusion pressure and reciprocal of cerebral mean transit time under the normal autoregulation of CBF. This ratio was calculated and compared with the normal value for each tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

MR imaging of dural arteriovenous malformations with ocular signs.

Four patients with dural arteriovenous malformation (AVMs) draining into the cavernous sinus, who presented ophthalmic manifestations, were studied by magnetic resonance (MR) imaging. In all patients signal decrease in the involved cavernous sinus was demonstrated in coronal spin-echo (SE) imaging. It is attributable to rapid venous flow in the sinus, and this "high velocity signal loss" is a fairly pathognomonic finding in this condition. We stress the validity of MR imaging in the primary diagnosis of dural AVMs with ophthalmic symptoms.

Arteriovenous Malformations↗
PubMed1988

The microvascular architecture of human malignant glioma. A scanning electron microscopic study of a vascular cast.

The three-dimensional microvascular architecture of human glioma was investigated. The results of the study, the first of its kind, suggested that the process of vascularization in glioma is based on two patterns. In a large proportion of the glioma, one pattern is similar to the vascularization observed in normal developing fetal and newborn rat brain, while in a small proportion of the glioma, another pattern including complicated vascular protrusion and spiral running, is seen.

Brain Neoplasms↗
PubMed1988

Pulmonary varices: a case report and review of the literature.

A case of a 47-year-old woman with pulmonary varix is reported herein. Saccular dilatation of the inferior pulmonary vein resembled a pulmonary perihilar mass which could not be palpated at the time of thoracotomy. Aneurysmal dilatation of the pulmonary vein, otherwise known as pulmonary varix, is rare. Only 71 such cases, including 17 cases in Japan, have been reported. Pulmonary varices may be classified into three types, namely: saccular type, tortuous type and confluent type. Most of the varices seen in patients with valvular disease have been of the confluent type (62 per cent), however tortuous type varices have also been seen in some cases (19 per cent). Pulmonary venous hypertension may be one of the major causes of confluent type pulmonary varices as regression of pulmonary varices after mitral valve replacement has been reported. None of the saccular type cases, however, were accompanied by valvular disease. This indicates that local factors may also be an important cause of saccular type varices.

Female↗
PubMed1988

Improved method for purification of toxic peptides produced by cyanobacteria.

The improved method consists of ODS-silica gel extraction, and separation on silica gel and HPLC with UV (238 nm) detector. The method has been successfully applied to the isolation of toxic peptides from the Monroe and M-228 strains of Microcystis aeruginosa. This method reduces toxin extraction and separation time, and so enables a rapid isolation of peptide toxins from cyanobacteria.

Chromatography, Gel↗
PubMed1988

Effects of a new Ca2+ antagonist, KB-2796, on the regional cerebral blood flow and somatosensory evoked potentials in the ischemic brain in cats.

Effects of a new Ca2+ antagonist, 1-[bis(4-fluorophenyl) methyl]-4-(2,3,4-trimethoxybenzyl) piperazine dihydrochloride (KB-2796), on the regional cerebral blood flow (rCBF) and somatosensory evoked potentials (SEPs) were investigated using a model of focal cerebral ischemia in cats. In experiment 1, an occlusion of the middle cerebral artery for 4 hours persistently reduced the ipsilateral rCBF in both the control and the KB-2796-treated groups. However, the flow reduction was much milder in the treatment group than in the control group. Amplitudes of the SEPs diminished in both groups but the rate of deterioration was much slower in the treatment group than in the control group. In experiment 2, an occlusion of the middle cerebral artery for 1 hour was followed by reperfusion for 3 hours. The ipsilateral rCBF decreased during occlusion in both the control and the treatment groups. In the control group, postischemic hyperperfusion was seen in the ectosylvian gyrus after reperfusion, whereas the ipsilateral rCBF recovered rapidly to the control values without showing a phase of hyperperfusion in the treatment group. The rate of recovery of the SEPs was also much more rapid in the treatment group.

Animals↗