Search PubMed⌕ Search

Biomedical subjects

T Ohtake

Publications and source records attributed to T Ohtake.

At least 109 records · Page 6Linked to original sources

Ascending projections from the gigantocellular reticular and dorsal paragigantocellular nuclei of the medulla oblongata in the rat: an anterograde PHA-L tracing study.

Ascending projections from the gigantocellular reticular (NGc) and dorsal paragigantocellular (DPG) nuclei of the medulla oblongata were examined in the rat by utilizing anterograde axonal transport of Phaseolus vulgaris leucoagglutinin (PHA-L). New observations of fiber connections could be made by the merits of the PHA-L. PHA-L-labeled axon terminals were observed in the dorsal part of the nucleus of the solitary tract, the rostrolateral subnucleus of the interpeduncular nucleus, bed nucleus of the stria terminalis, lateral septal nucleus and subfornical organ, in which no previous authors had found projections from the NGc or DPG. The strongest projections were observed in the motor nucleus of the trigeminal nerve, lateral and dorsolateral subnuclei of the facial nucleus, and prepositus hypoglossal nucleus, which suggested that both NGc and DPG had some relation to the movements around the mouth and to the eyeball movements. The projections to the dorsal part of the nucleus of the solitary tract and to the subfornical organ from the NGc and DPG are considered to reveal certain roles in cardiovascular regulation. Mainly, the facial nucleus received projections from the NGc, the subfornical organ from caudal NGc, the red nucleus from the DPG, and the rostrolateral subnucleus of the interpeduncular nucleus from the rostral DPG, respectively. The NGc and DPG would have partially different roles with regard to the ascending innervation. The present PHA-L study was partially confirmed using wheat germ agglutinin conjugated to horseradish peroxidase which was injected into the bed nucleus of the stria terminalis and subfornical organ.

Afferent Pathways↗

Quantitative analysis of immunocompetent cells in human periapical lesions: correlations with clinical findings of the involved teeth.

Human periapical lesions develop as a result of a pathological immune response to continuous stimuli from infected root canals. This study identified the immunocompetent cells in such lesions immunohistochemically and quantified them to examine their interrelationships and correlations with clinical findings. The number of IgG-containing cells in CD4+ cell (Th/i)-rich lesions (> or = 55 CD4+ cells/2 x 10(4) microns 2) was significantly larger than in CD4+ cell-poor lesions (< 55 CD4+ cells/2 x 10(4) microns 2). This indicated that the CD4+ cells and the IgG-containing cells acted together against antigenic stimuli. The proportion of T cells in the mononuclear infiltrates varied with the size of the periapical lesions. The proportion of CD11+ cells (monocytes/macrophages) was significantly larger in lesions which showed a positive reaction to percussion or were tender on palpation than in the lesions without these symptoms. These observations suggest that T cells may play an important role in the development of periapical lesions and that CD11+ cells may be involved in the development of symptoms.

Antigens, CD↗

[False positive reaction in measurement of allergen-specific IgE--comparison of 3M IgE FAST-Plus Test using polystyrene well as adsorbent with Phadezym RAST].

Irrelevant IgE binding to cellulose discs is known to give false positive results in Phadezym RAST (Pharmacia) for the estimation of allergen-specific IgE in serum. We investigated FAST-Plus Test (3M Diagnostic Systems), an enzyme-linked sandwich type Fluoro-Allergo-Sorbent Test in which a particular allergen was coated to polystyrene well. Phadezym RAST and CAP RAST (Pharmacia) using cellulose-derivative discs as adsorbent were used as reference methods. Patients' sera which gave negative blank reactions to uncoated filter paper disc in the Phadezym RAST system were assayed for specific IgE to 6 allergens using FAST-Plus Test, CAP RAST and Phadezym RAST, and the results of the former two were compared with those of Phadezym RAST using a comparable class system. FAST-Plus Test showed variable correlations with Phadezym RAST, the correlation coefficients ranged from 0.41 to 0.97 (r = 0.462 in house dust 1, r = 0.713 in house dust 2, r = 0.412 in Candida albicans, r = 0.952 in Dermatophagoides peteronyssinus, r = 0.969 in Dermatophagoides farinae and r = 0.682 in Japanese cedar), although most of the results were within one class difference. Similar correlations were obtained between CAP RAST and Phadezym RAST. Of 3004 patients' sera tested in the past two years using Phadezym RAST, 132 (96 cases) displayed positive blank reactions to the uncoated filter paper disc. Of the 96 cases, 80 sera were assayed for binding of IgE to the uncoated cellulose-derivative disc in the CAP RAST system. 18 showed positive results up to 7 IU/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗

[Metabolism of 99mTc-ethyl cysteinate dimer (99mTc-ECD) in blood--mainly in vitro].

Metabolism of 99mTc-ethyl cysteinate dimer (99mTc-ECD) in blood was studied mainly in vitro. When 99mTc-ECD was mixed with blood taken from 12 subjects, the octanol extraction ratio of ECD (y) decreased rapidly and the octanol extraction ratio-time profile well fitted a monoexponential curve (y = Ae-kt/1000, A, k: constant, t: time after mixing). The k value and hematocrit (Ht) were significantly correlated (k = 0.376Ht-3.27, r = 0.897, p less than 0.001), therefore, it was suggested that the majority of the enzyme which dissolves ECD exists in red blood cells. When ECD was mixed with blood, there were more hydrophilic products of ECD in plasma than those generated by the enzyme in plasma. In vivo input function of 99mTc-ECD was calculated by arterial blood sampling and octanol extraction. The duration of effective input was relatively short, which was attributed to rapid decrease of octanol extraction ratio in vivo.

Brain↗

[Clinical usefulness of exercise/rest 99mTc-teboroxime SPECT imaging: results of a Japanese multi-center phase II study].

99mTc-Teboroxime [Chloro[tris(cyclohexyldioxime)methaneboronic acid] (99mTc)technetium], a perfusion agent for myocardial imaging, has a distinct advantage over 201Tl because of its very high myocardial extraction and is a 99mTc compound ideal for gamma camera imaging. This agent also demonstrates rapid myocardial washout, which allows completion of exercise and rest imaging studies in a short interval (to 1 hour). However, the rapid washout necessitates the completion of image acquisition very quickly after injection and therefore may require nonconventional SPECT imaging. In this Phase II study we evaluate the safety and efficacy of 99mTc-Teboroxime to detect coronary artery disease by exercise and rest SPECT imaging in 38 patients with prior myocardial infarction, 31 patients with angina pectoris, and 4 patients with non-coronary cardiac diseases. The 99mTc-Teboroxime dose used was 370-740 MBq in each study. The findings were compared with coronary angiography or 201Tl exercise and redistribution SPECT. No significant adverse reactions or laboratory abnormalities attributable to 99mTc-Teboroxime were observed. The quality of SPECT images was optimal in 62.5% of all patients. The relatively large population of suboptimal cases (37.5%) was attributed to the delay of the start and prolongation of the image acquisition time. In 85.7% of patients whose imaging was started within 5 minutes and completed within 11 minutes after injection, optimal quality was observed. Thus, 99mTc-Teboroxime SPECT requires the rapid completion of image acquisition after injection to achieve optimal image quality. Abnormalities of 99mTc-Teboroxime distribution were detected in 97.1% and 62.1% of patients with prior myocardial infarction or angina pectoris, respectively. The concordance with coronary angiography was 84.4% and 68.0%, and with 201Tl was 78.1% and 74.1%, respectively. Although standardization of the image protocol suitable for this agent is needed for the next study, these high correlations suggest the potential usefulness of 99mTc-Teboroxime SPECT imaging.

Adult↗

[Clinical application of 18F-FDG-PET in patients with brain death].

In order to evaluate glucose metabolism in brain death, 18F-FDG-PET scans were performed in three patients with clinically highly suspected brain death. One case was caused by head trauma and other two cases were by subarachnoid hemorrhage. All of them were in deep coma without spontaneous breathing, whose intracranial pressure was remarkably elevated up to the level of mean arterial pressure. Nineteen frames of dynamic scan were started soon after intravenous injection of 18F-FDG for one minute per frame, followed by 10 minutes of static scan which started 40 minutes after the injection. Both in dynamic and static scan, no significant intracranial accumulation of 18F-FDG was seen in all of three cases. This finding can be interpreted as the evidence that there is no significant glucose utilization from blood in the brain. This is the first report of clinical application of 18F-FDG-PET to brain death. Our results support the clinical diagnosis of brain death and 18F-FDG-PET can be of value for the assessment of glucose metabolism in patients with suspected brain death.

Adult↗

[Phase 3 study of beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid, a myocardial imaging agent for evaluating fatty acid metabolism--a multi-center trial].

A multi-center trial of beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid (123I-BMIPP) was performed to assess its clinical usefulness in the evaluation of myocardial fatty acid metabolism in 587 patients with various heart diseases. 123I-BMIPP showed relatively decreased uptake compared with 201Tl in the myocardial lesions of 62% of patients with ischemic heart disease (IHD), 39% of those with cardiomyopathy and 32% of those with other heart diseases. In case of myocardial infarction, less uptake of 123I-BMIPP (Type B) than 201Tl was more frequently seen in patients with successful recanalization than in those without recanalization. The patients with matched distribution of the two tracers (Type E) increased in the direct proportion to the interval between the onset of myocardial infarction and the radionuclide studies. The uptake of 123I-BMIPP correlated well with myocardial viability evaluated by 201Tl exercise-redistribution studies. Type B was frequently seen in the areas with 201Tl redistribution, while Type E was seen in the fixed defect areas. In the other heart diseases studied, Type E was observed in approximately 60% of patients with dilated or secondary cardiomyopathies. Type B was seen in about 45% of patients with valvular heart diseases and myocarditis. Various types of mismatch between the two tracers were demonstrated in hypertrophic cardiomyopathy and hypertensive heart disease. It is concluded that 123I-BMIPP is a safe and useful agent for the diagnosis of various heart diseases, since it reflects myocardial fatty acid metabolism.

Adolescent↗

[Bone scan "flare" in patients irradiated to formerly false negative bone metastasis].

We discuss three cases irradiated to their bone metastases. 99mTc-MDP bone scan before irradiation showed normal uptake in the lesions. In all the cases, the irradiation therapy was effective, but focal increased uptake area corresponding to the site of bone metastasis was revealed by the follow-up bone scan one to three months after irradiation. We concluded that the change of tracer uptake was so-called flare in formerly false negative lesion. The cause of this phenomenon was considered either elevation of osteoblastic activity with control of tumor or progression of osteolysis until tumor got well-controlled.

Aged↗

[Intra-arterial and intraportal infusion liver scintigraphy using 99mTc-labeled colloid].

Intra-arterial infusion liver scintigraphy was performed in 11 patients with primary or metastatic liver tumor, and intraportal infusion liver scintigraphy was performed in 6 patients for prophylaxis of liver metastasis from colorectal cancer. 99mTc-Sn colloid or 99mTc-phytate was administered through the catheter of which tip was placed in the portal vein or the hepatic artery, and then liver image was obtained. When 99mTc-phytate was infused intra-arterially, significant amount of the infused tracer passed through the liver and we could not get sufficient information to assess the distribution of drug administered through the catheter. On the other hand, intraportal infusion liver scintigraphy using 99mTc-Sn colloid or 99mTc-phytate and intra-arterial infusion liver scintigraphy using 99mTc-Sn colloid revealed heterogeneity of liver uptake, tracer uptake in spleen, low uptake area corresponding to the liver tumor and high uptake area around it. The findings will be clinically useful, and these methods are thought to be helpful to confirm the satisfactory drug distribution.

Adult↗

[Monoparesis due to the brachial plexus neuritis by herpes zoster virus--report of a case].

A 73-year-old woman suffering from the acute onset monoparesis of her right arm which followed the skin eruption with mild sensory disturbance of right C4-6 level, was reported. Electrophysiological examinations revealed the brachial plexus neuritis and axonal degeneration of the proximal portion, with the evidence of herpes zoster infection. Her paresis of the right arm gradually improved without any medication during her hospital course. It was concluded that herpes zoster should be considered to be one of the causes of acute onset brachial plexopathy.

Aged↗

[Clinical application of 99mTc-SQ30,217 myocardial imaging--a study of pharmacokinetics and imaging time].

99mTc-SQ30217 555 MBq (15 mCi) was intravenously injected to 6 healthy subjects to study its safety, pharmacokinetics and the imaging time. Neither side effects nor abnormalities in physical findings, hemato-biochemical tests, urinary test, etc. caused by this agent were observed in any case and its safety was suggested. Radiation dose estimates over the entire body was 4.88 mGy/1,110 MBq (0.488 rad) and that over the major organs was less than 10 mGy and they were within the allowable ranges. 99mTc-SQ30217 showed biphasic disappearance curve in blood with the half-life of alpha-phase 0.02 hour and that of beta-phase 10.14 hours. 99mTc-SQ30217 was considered to show characteristic pharmacokinetics in that the myocardial accumulation was high in an early stage of the administration, but it rapidly decreased. Both heart to liver ratio and heart to lung ratio were high within 10 minutes, but they decreased after 15 minutes. As a result of SPECT imaging of 4 patients with ischemic cardiac disease, the images obtained with 99mTc-SQ30217 at an early period after the administration was as good as those with 201Tl and the appearance of defects in the images with both agents was similar. 99mTc-SQ30217 was considered to be sufficiently useful as a 99mTc-labelled agent for myocardial blood flow.

Adult↗

Noninvasive method to obtain input function for measuring tissue glucose utilization of thoracic and abdominal organs.

We have developed a method for the noninvasive estimation of regional tissue glucose utilization in humans that employs positron emission tomography (PET) and 2-(18F)fluoro-2-deoxy-d-glucose (FDG). Unlike other methods, the input function used in this method is obtained from the corrected time-activity curve of the descending aorta, not the left ventricle, because the descending aorta is relatively free of spillover from other organs and extends from the upper thorax to the lower abdomen. With this method the time-activity curve of the descending aorta must be corrected for the partial volume effect and the difference in counts between plasma and whole blood. Using the noninvasively obtained input function, regional tissue glucose utilization was calculated by Patlak graphic analysis. k1k3/(k2 + k3) was in good agreement with k1k3/(k2 + k3) calculated from the plasma input function by arterial sampling (r = 0.9995). These results suggest that the input function and regional tissue glucose utilization (not only of myocardium but also of other thoracic and abdominal organs) can be determined noninvasively.

Abdomen↗

CNS involvement in Japanese patients with chronic inflammatory demyelinating polyradiculoneuropathy.

Thirteen consecutive Japanese patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) were studied by MRI, evoked potentials, and EEG. We found 3 of these patients exhibited symptoms of CNS disorders. Of these 3, 2 with abnormal MRI and visual evoked potentials, and one with abnormal brainstem auditory evoked potentials were detected. Another case without clinical CNS signs showed abnormal EEG findings. The subclinical CNS abnormalities found in the Japanese patients were considered to be less frequent than in cases from Western countries reported previously.

Adolescent↗

[A rapid diagnosis for periodontitis based on enzymatic activity of periodontopathic bacteria. Correlation between enzymatic activity, clinical periodontal parameters, and subgingival level of microorganisms].

There have been various laboratory methods for the microbiological diagnosis of periodontal disease. However, there have been some disadvantages in these methods. In this study of the application of a chair-side test for microbiological diagnosis, the activity of peptidases in periodontal pockets of patients was examined by using the assay system SK-013. SK-013 consists of synthetic substrates and is capable of rapidly (in 15 min) evaluating the activity of specific peptidase from Treponema denticola and Bacteroides species. Using SK-013, we evaluate the correlation between the enzymatic activity, clinical periodontal parameters and subgingival level of microorganisms, including phase contrast microscopy. We calculated the sensitivity and efficacy of SK-013 as a diagnostic indicator in the presence of Spirochetes and in periodontitis. A positive correlation were demonstrated between enzymatic activity, clinical periodontal parameters, the numbers of total cell count, Spirochetes, and M & S ratio. SK-013 was highly sensitive and efficacious (sensitivity: 92%, efficacy: 96%). We concluded that the assay system SK-013 is a useful chair-side method for diagnosing periodontal disease.

Bacteroides↗

[Preliminary screening for antiviral AIDS drugs. I. Report on fiscal year 1988].

Preliminary screening for antiviral AIDS drugs has been carried out, using three different in vitro assay systems. Among 105 samples tested, 13 were found to inhibit the growth of HIV in vitro. Eleven of 13 were well-known anti-HIV chemicals, while the remaining two of plant origin were new chemicals whose anti-HIV activities have not been reported elsewhere.

Antiviral Agents↗

[Chronic inflammatory demyelinating polyradiculoneuropathy associated with central nervous system involvement--as compared to multiple sclerosis].

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with central nervous system (CNS) demyelinating lesions has recently been reported to mimic multiple sclerosis (MS). In this paper, a series of patients with CIDP were examined to see if they had CNS involvement. CIDP patients with CNS lesions were then compared to patients with MS with peripheral nervous system (PNS) involvement for similarities. CNS and PNS involvement were detected by clinical symptoms, neurological findings, neuro-otological and neuro-ophthalmological tests, electrophysiological examinations such as electroencephalography, evoked potentials, blink reflex, conventional peripheral nerve conduction studies and electromyography, as well as computed tomography and magnetic resonance imaging (MRI). There were 7 of 17 CIDP patients with CNS involvement, but only 2 of 59 MS patients with PNS lesions were found. The rate of CIDP with CNS involvement (41.2%) was higher than that of MS with PNS lesions (3.4%). The CNS signs and symptoms of 7 CIDP patients were not so constant as their PNS symptoms, and consisted of 1 case with optic neuritis, 4 cases with cerebellar atxia and/or nystagmus, and 3 cases with spinal symptoms. These signs and symptoms are all well known in MS. Prolonged latencies on evoked potentials and high signal white matter lesions on T2 weighted MRI, indicating demyelinating CNS lesions were also similar to those found in MS. The CNS involvement in those patients with CIDP was therefore similar in character to those found in MS, but was far less severe than the PNS finding.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗