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Biomedical subjects

K Hisada

Publications and source records attributed to K Hisada.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Temporal lobe epilepsy associated with old intracerebral hemorrhage due to capillary telangiectasis in the temporal lobe: case report].

A case of 45-year-old female, who presented with temporal lobe epilepsy was reported. The patient was found to have old intracerebral hemorrhage due to capillary telangiectasis in the temporal lobe. On the intraoperative electrocorticography, frequent paroxysmal activities were recorded independently both on the medial and lateral aspects of the temporal lobe. Even after resection of the lateral temporal lobe, frequent paroxysmal discharges were noted on the hippocampus. Histologically, there are astrogliosis and hemosiderin deposits in the white matter around the telangiectasis and the old hematoma. It is postulated that the hippocampus gained secondary epileptogenicity.

Adult↗
PubMed1999

[Schizencephaly: clinical and MRI features].

We report the clinical and neuroimaging features of 4 cases with schizencephaly. Case 1 had bilateral schizencephaly with open-lip on the right and closed-lip on the left. Case 2 had unilateral schizencephaly with closed-lip on the left and subcortical heterotopia on the right. Case 3 had unilateral schizencephaly with closed-lip on the left. Case 4 had bilateral closed-lip schizencephaly. Although all cases except for Case 3 had bilateral lesions, neurodevelopmental outcome was generally good; Case 1 and 3 had mild hemiparesis. All patient have epilepsy which are well-controlled with antiepileptic drugs. Thus, the clinical presentation of schizencephaly, even if bilateral lesions, are quite variable.

Adolescent↗
PubMed1998

[Efficacy of the fluid attenuated inversion recovery (FLAIR) sequence of MRI as a preoperative diagnosis of hippocampal sclerosis].

A newly advanced MRI pulse sequence, the FLAIR (fluid attenuated inversion recovery) imaging, in which a long TE spin echo sequence is used with suppression of the CSF with an inversion pulse, displays the CSF space as a no-signal intensity area. There have been only a few reports on the FLAIR pulse sequence of temporal lobe epilepsy (TLE) as yet. We examined 9 cases of intractable TLE by FLAIR images and analyzed the advantages and disadvantages of the FLAIR pulse sequence for decision making on temporal lobectomy. All patients underwent anterior temporal lobectomy with hippocampectomy, and the diagnoses were confirmed histologically after surgery. Abnormally high T2 signals (HT2S) were more conspicuous with the FLAIR sequence than with any of the conventional sequences. Tilted axial plane, orientated along to the long axis of the hippocampal body, clearly demonstrated hippocampal atrophy (HA). Selection of a FLAIR sequence into the routine MR examination of patients with TLE is recommended.

Adolescent↗
PubMed1998

[Two cases of mesial temporal lobe epilepsy associated with old intracerebral hemorrhage in the lateral temporal lobe without "dual pathology"].

Two cases of intractable temporal lobe epilepsy associated with old intracerebral hemorrhage in the lateral temporal lobe were reported. Although preoperative magnetic resonance imaging (MRI) failed to reveal hippocampal atrophy with T2 hyperintensity, electrocorticographic (ECoG) recording with chronic invasive subdural electrodes indicated the mesial temporal lobe to be an ictal onset zone. After anterior temporal lobectomy involving the lesion and hippocampectomy, the patients became seizure-free. Hippocampal sclerosis, namely "dual pathology", was not noted on histological examination. Careful ECoG recording with chronic subdural electrodes is mandatory even when the preoperative MRI does not demonstrate the radiological hippocampal sclerosis.

Adult↗
PubMed1997

[Dual isotope SPECT with 99mTc and 123I using four-energy-window (FEW) method].

We devised "four-energy-window" (FEW) method which permits simultaneous acquisition for dual isotope single photon emission tomography (SPECT) studies using 99mTc and 123I of which photopeak is in close vicinity to each other. This acquisition method requires a total of four energy windows: two main windows for 99mTc (126-143 keV) and 123I (156-175 keV), respectively, and two 5% sub-windows which are set below the 99mTc window and above the 123I window, respectively. Two virtual windows (5%) are additionally set above the 99mTc and below the 123I window, respectively, to apply the triple-energy-window (TEW) method for the scatter correction. A phantom study demonstrated that photocounts from the two radionuclides could be completely separated from each other and that SPECT images obtained had preferable property for quantitative analysis. This method was applied to clinical, dual-radionuclide myocardial studies using 99mTc-MIBI and 123I-BMIPP, and was found to provide excellent images each tracer.

3-Iodobenzylguanidine↗
PubMed1996

Regional cerebral blood flow in patients with schizophrenia: relevance to symptom structures.

Regional cerebral blood flow (rCBF) was measured with technetium-99m hexamethylpropyleneamine oxime single photon emission computed tomography in 38 neuroleptic-treated schizophrenic patients. To improve the validity of the evaluation of symptomatology, we applied findings previously derived in a principal component analysis (PCA) of the Positive and Negative Syndrome Scale. The PCA had disclosed five orthogonal independent symptom structures (i.e., negative, hostile/excited, thought disordered, delusional/hallucinatory, and depressive components), and obtained factor scores for 70 schizophrenic subjects, including the present sample. Stepwise regression analysis elucidated some of the cortical regions in which relative rCBF predicted the severity of symptoms--namely, lateral and orbital prefrontal, lateral temporal, inferior parietal, and medial temporal regions. Findings suggested that symptom structures derived from PCA could prove helpful in elucidating the pathophysiology of neural mechanisms.

Adult↗
PubMed1996

Comparison of defect size between thallium-201 and technetium-99m tetrofosmin myocardial single-photon emission computed tomography in patients with single-vessel coronary artery disease.

Defect size on exercise-rest technetium (Tc)-99m tetrofosmin myocardial perfusion imaging was compared with that on exercise-reinjection thallium-201 imaging with 20 patients with 1-vessel coronary artery disease. In each patient, exercise-reinjection thallium-201 single-photon emission computed tomography (SPECT) and exercise-rest Tc-99m tetrofosmin SPECT imaging were performed. For visual analysis of the obtained SPECT images, the left ventricular myocardium was divided into 20 segments based on 3 short-axis slices from the apical, middle, and basal ventricular levels. For quantitative analysis, a square region of interest was placed on the center of each segment which was used for visual analysis, and relative regional activity to the normal reference region was calculated for each segment. By visual interpretation of the images, exercise Tc-99m tetrofosmin imaging showed a smaller defect size than exercise thallium-201 imaging (6.9 +/- 3.9 vs 8.8 +/- 3.0 segments, p <0.01). In contrast, rest Tc-99m tetrofosmin imaging showed a defect size similar to that on reinjection thallium-201 imaging (5.9 +/- 3.6 vs 5.6 +/- 3.9 segments, p = NS). Similarly, the mean defect sizes during exercise determined by quantitative analysis were smaller on Tc-99m tetrofosmin SPECT than those on thallium-201 SPECT at all tested threshold cutoff points ranging from 50% to 70%, whereas there were no significant differences in defect sizes between rest Tc-99m tetrofosmin and reinjection thallium-201 imaging. These data indicate that exercise Tc-99m tetrofosmin SPECT defect size determined either by visual analysis or by quantitative analysis may be smaller than on exercise thallium-201 SPECT.

Aged↗
PubMed1996

Technetium-99m tetrofosmin uptake in lung cancer: comparison with thallium-201.

Technetium-99m tetrofosmin and thallium-201 lung SPECT imaging were performed in a patient with adenocarcinoma of the lung. Significant activities in the lung lesion were clearly depicted on both technetium-99m tetrofosmin and thallium-201 SPECT imaging. The early uptake, delayed uptake ratios and retention indices of the tumor were 2.75, 2.39 and -1.31 for thallium-201 imaging and 3.09, 2.27 and -26.5 for technetium-99m tetrofosmin imaging, respectively. This preliminary report suggests that technetium-99m tetrofosmin may have potential as a tumor imaging agent.

Adenocarcinoma↗
PubMed1996

Effect of induced hypertension with angiotensin II infusion on biodistribution of 111in-labeled monoclonal antibody.

We investigated whether induced hypertension could enhance tumor uptake of monoclonal antibody. 111In-DTPA-A7 (IgG1 against 40kD tumor associated glycoprotein) was injected into colon carcinoma xenografted mice which were subcutaneously implanted with micro-osmotic pump containing angiotensin II (AT-II). Biodistribution was observed in groups of mice infused with AT-II at rate of 0.5 micrograms/kg/min (L) or 1 microgram/kg/min (H) and compared with a group of mice infused with saline (S). Tumor uptake of 111In-A7 in L and H was 1.32 and 1.57 times greater than S at 48 h after intravenous injection of A7. Normal organ uptakes also tended to be increased by AT-II infusion. Further study is needed to get optimum effect of hypertensive treatment on biodistribution of radiolabeled MoAb.

Angiotensin II↗
PubMed1996

Impaired fatty acid uptake in ischemic but viable myocardium identified by thallium-201 reinjection.

Iodine 123-labeled 15-iodophenyl-3-methyl-pentadecanoic acid (BMIPP) has been proposed as a potential myocardial fatty acid probe. We studied BMIPP uptake in ischemic myocardium identified by thallium reinjection. Fifty-five patients with coronary artery disease who had persistent defects on standard exercise-redistribution thallium imaging were investigated. Patients underwent exercise-redistribution-reinjection thallium and resting BMIPP imaging. BMIPP uptake less than that seen with thallium on reinjection imaging was observed in 105 (82%) of 128 myocardial segments with new fill-in after thallium reinjection and 87 (37%) of 238 segments with reversible thallium defects. In contrast, only 32 (19%) of 166 segments with no fill-in showed discordantly decreased BMIPP uptake. Quantitative analysis showed reduction in BMIPP activity compared with differential uptake of thallium, an index of resting myocardial perfusion, especially in the area of fill-in (53.5% +/- 15.0% vs 76% +/- 12.1% of peak; p<0.01). These observations are consistent with impaired fatty acid uptake in ischemic myocardium, particularly in the area of fill-in after thallium reinjection.

Adult↗
PubMed1996

Scintigraphic study of malignant melanoma with 123I-iodoamphetamine.

N-isopropyl-p-I-123-iodoamphetamine (123I-IMP) is extracted by the brain in proportion to regional blood flow. It is particularly useful in the clinical assessment of various pathological conditions related to altered cerebral flow. Moreover, it has been reported that 123I-IMP is avidly incorporated into melanin and melanotic melanoma. We evaluated 123I-IMP scintigraphy using either planar or single photon emission tomography (SPET) studies in 10 patients with malignant melanoma. The patients were classified into two groups according to the tumour site: Group A, six patients with primary or metastatic cutaneous malignant melanoma of the extremity with planar scintigraphy; Group B, four patients with primary malignant melanoma of other organs with planar scintigraphy and SPET. In Group A, tumour uptake was demonstrated in four of six patients; in Group B, three of four patients had tumour accumulation on SPET and planar scintigraphy. SPET revealed the exact tumour localization, even in the case of a tumour located in the lung. These results suggest that planar scintigraphy using 123I-IMP is useful in the detection of malignant melanoma. Furthermore, more clear tumour localization is possible with SPET, even in the case of a tumour located in the lung.

Aged↗
PubMed1996

Hyperperfusion and hypermetabolism in brain radiation necrosis with epileptic activity.

We report a case of high uptake of 11C-methionine (MET), 18F-FDG (FDG) and 201Tl-Cl (Tl) in brain radiation necrosis. Twenty-one years previously, the patient had undergone surgery and radiation therapy consisting of 60-Gy for ependymoma in the anterior horn of the right lateral ventricle. The clinical features consisting of frequent seizures of the left face and arm suddenly appeared 2 wk before admission. MRI depicted a Tl and T2-prolonged lesion in the right frontal lobe. Abnormally high uptake in this area demonstrated by MET-PET, FDG-PET, Tl-SPECT or HMPAO-SPECT suggested the presence of a recurrent tumor. A craniotomy was then performed and an intraoperative electrocorticogram showed continuous epileptic spikes in the lesion. The epileptic foci were resected and the histological features of the lesion were consistent with radiation necrosis. After surgery, the seizures disappeared and the postoperative examinations with MET-PET, FDG-PET, Tl-SPECT and HM-PAO-SPECT no longer showed abnormally high uptake. Hypermetabolism and hyperperfusion related to epileptic fits are therefore thought to result in high uptake of MET, FDG and Tl in radiation necrosis.

Adult↗
PubMed1996

[Effectiveness of the radioactive strontium (89Sr) chloride agent, SMS.2P for pain palliation in patients with metastatic bone tumor in phase III multicenter clinical trial].

The phase III clinical trial of strontium-89 chloride agent (SMS.2P) was performed in 90 patients with painful bone metastases secondary to prostate (53), breast (18) and other types of cancer (19). Some patients experienced a transient increase in pain or nausea and vomiting. However both symptoms subsided and serious side effects were not observed in any of the patients. As reported, we confirmed some abnormal changes in peripheral blood picture. A decrease in the number of white blood cells and platelets was considered to be partly a result of bone marrow suppression due to 89Sr irradiation. Pain was substantially improved after 89Sr therapy in 58% of the patients and there was some alleviation in 12%. The release from pain was accompanied by an improved quality of life for these patients including sleep patterns and morbidity. Some patients were able to resume their former life styles. Most of the improved patients experienced pain relief from days to one week following 89Sr therapy and in half cases, this remained effective for 2 or 3 months. There were even cases in which the pain relief continued over an observation period of time of clinical study.

Adult↗
PubMed1995

A quantitative approach to technetium-99m ethyl cysteinate dimer: a comparison with technetium-99m hexamethylpropylene amine oxime.

To develop non-invasive regional cerebral blood flow (rCBF) measurements using technetium-99m ethyl cysteinate dimer (99mTc-ECD) and single-photon emission tomography (SPET), the same graphical analysis as was described in our previous reports using technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) was applied to time-activity data for the aortic arch and brain hemispheres after intravenous injection of 99mTc-ECD. Hemispherical brain perfusion indices (BPI) for 99mTc-ECD showed a highly significant correlation (n = 22, r = 0.935, P = 0.0001) with those for 99mTc-HMPAO in 11 patients who underwent both tracer studies. Using both linear regression line equations between 99mTc-ECD BPI and 99mTc-HMPAO BPI and between 99mTc-HMPAO BPI and mean cerebral blood flow (CBF) values obtained from a xenon-133 inhalation SPET method in a previous study, 99mTc-ECD BPI was converted to 133Xe CBF values (y = 2.60 chi + 9.8). Then raw SPET images of 99mTc-ECD were converted to rCBF maps using Lassen's correction algorithm. In this algorithm, the correction factor alpha was fixed to 1.5, 2.6 and infinite. In the comparison of rCBF values for 99mTc-ECD SPET with those for 99mTc-HMPAO SPET in 396 regions of interest in the aforementioned 11 patients, the fixed correction factor alpha of 2.6 gave nearly the same rCBF values for 99mTc-ECD (50.1 +/- 16.9 ml/100 g/min, mean +/- SD) as for 99mTc-HMPAO (49.9 +/- 17.3 ml/100 g/min). In conclusion, the same non-invasive method as has been used in 99mTc-HMPAO studies is applicable to a 99mTc-ECD study for the measurement of rCBF without any blood sampling.

Adult↗
PubMed1995

Intense accumulation of Tc-99m MDP and Ga-67 in multiple periapical cemental dysplasia.

A case of multiple periapical cemental dysplasia is presented and intensive accumulation of Tc-99m MDP and Ga-67 is described. A 53-year-old woman was admitted with an intermittent pain and swelling of the left buccal region. The radiograph showed multiple sclerotic masses covering entire periapical regions of the teeth, in both the maxilla and mandibula. Biopsy of the maxilla facilitated a definitive diagnosis of multiple periapical cemental dysplasia.

Dental Cementum↗
PubMed1995

Synthesis of radioiodinated analogs of 2-(4-phenylpiperidino)cyclohexanol (vesamicol) as vesamicol-like agent.

Three iodovesamicol analogs, iodinated at the ortho, meta, and para positions of the 4-phenylpiperidine moiety, were synthesized and labeled with 125I by isotopic exchange reaction. Their potencies as a vesamicol-like drug were evaluated with competitive inhibition studies using (-)[3H]vesamicol. The radiochemical yields were 40-85%, the radiochemical purities exceeded 95% and their specific activities were 370-740 GBq/mmol. The descending order of binding affinity of the tested compounds against the vesamicol receptor was m-iodovesamicol > o-iodovesamicol > p-iodovesamicol. The receptor binding affinity of m-iodovesamicol (IC50 = 133 nM) was comparable with that of vesamicol (IC50 = 109 nM). Therefore, the meta position of the 4-phenylpiperidinyl fragment of vesamicol was the optimum site for iodination, and radioiodinated m-iodovesamicol may serve as a useful radiopharmaceutical for in vitro and in vivo studies of presynaptic cholinergic neurons in rats.

Animals↗
PubMed1995

In vivo characterization of radioiodinated 2-(4-phenylpiperidino)cyclohexanol (vesamicol) analogs: potential radioligand for mapping presynaptic cholinergic neurons.

Iodovesamicol analogs, radioiodinated at the ortho (1), meta(2) and para(3) positions of the 4-phenylpiperidine moiety, were evaluated as potential presynaptic cholinergic neuron mapping agents. Significant accumulation of m-[125I]iodovesamicol (mIV(2)) (about 3% of the injected dose) was noted in the rat brain with prolonged retention times. The accumulation of mIV(2) in the rat brain was decreased by 67% by 5 min pre-injection of dl-vesamicol(1 mumol/kg). Pre-injection of (+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperdine[(+)-3-PPP](0.75 mumol/kg) did not markedly decrease the levels of radiotracers (oIV(1) and mIV(2)) in the rat brain. These results suggest that radioidinated m-iodovesamicol (mIV(2)) is suitable for use in presynaptic cholinergic neuron mapping.

Animals↗