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Biomedical subjects

M Takada

Publications and source records attributed to M Takada.

At least 289 records · Page 16Linked to original sources
PubMed1995

[The catecholamine concentrations of collected autologous blood during adrenalectomy for pheochromocytoma].

We studied the catecholamine concentrations in collected autologous blood of a patient undergoing adrenalectomy for pheochromocytoma. In the preoperative laboratory data, plasma concentrations (normal ranges) of epinephrine, norepinephrine and dopamine were 60180 pg.ml-1 (< 100), 11090 pg.ml-1 (100-450) and 104 pg.ml-1 (< 20), respectively. The catecholamine levels of collected blood were epinephrine 2490000 pg.ml-1, norepinephrine 352300 pg.ml-1 and dopamine 6100 pg.ml-1 before wash. Wash of collected blood with 1000 ml saline diluted the catecholamines to epinephrine 212000 pg.ml-1, norepinephrine 18700 pg.ml-1 and dopamine 4900 pg.ml-1. Platelet activation by contact with tissue collagen or thrombin results in the release of catecholamine concentrated in the dense body. The mechanical stimulation by suction, roller pump and centrifugation during blood collection may accelerate the catecholamine release from platelets. Thus, saline wash hardly reduces catecholamine concentrations of collected blood from a patient with pheochromocytoma. In this particular case, plasma catecholamines seem to exceed the potential capacity of platelets in amount. The dilution effect for epinephrine and norepinephrine probably reflects the washout of greater amount of plasma catecholamines. However, saline wash was unable to reduce catecholamines contained in the collected blood to a safe level, and hypertension following autotransfusion was predictable. We conclude that hemodynamic change should be monitored carefully during intraoperative autotransfusion in a case of pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1995

[Primary hyperparathyroidism--pathological findings and ultrastructure].

Primary hyperparathyroidism may be caused by one or two benign tumors in separate glands, adenoma, a malignant tumor of one gland, carcinoma or hyperplasia of all four glands. Pathologically, the main problem lies in distinguishing between primary chief cell hyperplasia and adenoma, it is impossible from pathological findings of only one gland. Parathyroid adenomas and chief cell hyperplasias contain large numbers of active chief cells. The cells contain aggregated arrays of rough endoplasmic reticulum and large, complex Golgi apparatus with numerous vacuoles and vesicles. Secretory granules are often present in these cells. Most of the cells are generally interpreted to be in the more active phases of parathyroid hormone synthesis and secretion.

Humans↗
PubMed1995

[Primary trabeculectomy for open-angle glaucoma with mitomycin C].

We examined the results of postoperative intraocular pressure (IOP) control and complications of trabeculectomy with mitomycin C in open angle glaucoma patients who had not undergone any other ocular surgery. The subjects were 80 eyes of 70 patients who underwent surgery with 0.04% mitomycin C as an adjunct for 3 minutes and were followed for 7-24 months (mean +/- standard deviation: 13 +/- 3.4). The preoperative IOP was 21-32 mmHg (mean +/- standard deviation: 24.6 +/- 4.3) in maximum tolerable medications. IOP control ratio, which was analysed with the Kaplan-Meier method at 24 months after surgery was 81.6% without any antiglaucoma medications, vs 92.0% with medications. These values were significantly higher (p < 0.05) than the results of trabeculectomy with 5-fluorouracil or without antimetabolic agents previously performed in our clinic. Shallow chamber in 18 eyes (23%), choroidal detachment in 14 eyes (18%), hypotonus maculopathy in 7 eyes (9%), and cataract progression in 5 eyes (7%) were recognised as complications. Although there are some complications to be conquered, trabeculectomy with mitomycin C seems to be effective in treating primary open angle glaucoma patients.

Adult↗
PubMed1994

One subspecies of the red junglefowl (Gallus gallus gallus) suffices as the matriarchic ancestor of all domestic breeds.

The noncoding control region of the mitochondrial DNA of various gallinaceous birds was studied with regard to its restriction fragment length polymorphism (RFLP) and sequences of the first 400 bases. Tandem duplication of the 60-base unit was established as a trait unique to the genus Gallus, which is shared neither by pheasants nor by quails. Unlike its close ally Gallus varius (green junglefowl), the red junglefowl Gallus gallus is a genetically very diverse species; the 7.0% sequence divergence was seen between those from Thailand (G. g. gallus and G. g. spadiceus) and the other from the Indonesian island of Java (G. g. Bankiva). Furthermore, the divergence increased to 27.83% if each transversion is regarded as an equivalent of 10 transitions. On the other hand, a mere 0.5-3.0% difference (all transitions) separated various domestic breeds of the chicken from two G. g. gallus of Thailand, thus indicating a single domestication event in the area inhabited by this subspecies of the red junglefowl as the origin of all domestic breeds. Only transitions separated six diverse domesticated breeds. Nevertheless, a 2.75% difference was seen between RFLP type I breeds (White Leghorn and Nagoya) and a RFLP type VIII breed (Ayam Pelung). The above data suggested that although the mitochondrion of RFLP type V was the main contributor to domestication, hens of other RFLP types also contributed to this event.

Animals↗
PubMed1994

Analysis of IL-2 gene regulation in c-fos transgenic mice. Evidence for an enhancement of IL-2 expression in splenic T cells stimulated via TCR/CD3 complex.

Effects of the deregulated c-fos gene product on IL-2 expression were studied in splenic T cells from c-fos transgenic (H2-c-fos) mice. IL-2 gene expression and IL-2 production by H2-c-fos T cells stimulated with immobilized anti-CD3 Abs were enhanced and prolonged as compared with those by control T cells. Activator protein-1 activity in nuclear extract from the H2-c-fos T cells was also higher than that from the control cells. There was no significant difference in the activity of other transcription factors including IL-2 kappa B, NFAT, and Oct-1, between the H2-c-fos and the control T cells. However, activity of a negative regulatory element binding factor (NRE-A) in the H2-c-fos T cells was much lower than that in the control cells. These results suggest that c-Fos/activator protein-1 is a major regulatory factor for IL-2 gene expression in splenic T cells activated through the TCR/CD3 complex.

Animals↗
PubMed1994

Single retinal ganglion cells projecting bilaterally to the lateral geniculate nuclei or superior colliculi by way of axon collaterals in the cat.

In most mammals with frontalized eyes, retinal ganglion cells in the nasal or temporal retina send their axons to the contralateral or ipsilateral half, respectively, of the brain. Previous studies in the cat, however, have indicated a retinal region of "nasotemporal overlap" from which arise the retinal projections to both the contralateral and ipsilateral halves of the brain. The present study thus examined in the cat whether any retinal ganglion cells give rise to bifurcating axons that innervate both halves of the brain. By employing fluorescent retrograde double labeling, we investigated whether or not single retinal ganglion cells project bilaterally to the lateral geniculate nuclei or superior colliculi by way of axon collaterals. After Fast Blue was injected into the lateral geniculate nucleus on one side and Diamidino Yellow was injected contralaterally into the lateral geniculate nucleus, 100-200 ganglion cells in each retina were double labeled with both tracers. These double-labeled cells were distributed primarily in the temporal retina, including the region around the vertical meridian and, additionally, in the nasal retina. About 60-80% of the double-labeled cells had large cell bodies (more than 25 microns in diameter), and the others had medium-sized ones (15-25 microns in diameter). The pattern of distribution of double-labeled cells, which was observed after the combined injection into both superior colliculi, was similar to that seen after the combined injection into both lateral geniculate nuclei; more than 90% of double-labeled cells, however, were large.(ABSTRACT TRUNCATED AT 250 WORDS)

Amidines↗
PubMed1994

The gradient of basic fibroblast growth factor concentration in human pancreatic cancer cell invasion.

It has been reported that basic fibroblast growth factor (b-FGF) is overexpressed in human pancreatic cancer cells, and that the overexpressed b-FGF contributes to the disease progression (Yamanaka et al. Cancer Res. 53, 5292-5297, 1993). Pancreatic cancer aggressively invades surrounding tissues by penetrating basement barriers. Thus, effect of b-FGF on pancreatic cancer, cell invasion to Matrigel basement membrane, was studied. The high gradient of b-FGF increased the invasiveness of human pancreatic cancer cells in a dose-dependent manner. Furthermore, the invasiveness of the cells was suppressed by anti-FGF receptor antibody. These results suggest that b-FGF plays an important role in human pancreatic cancer cell invasion to basement membrane.

Collagen↗
PubMed1994

Platelet release reaction during EDTA-induced platelet agglutinations and inhibition of EDTA-induced platelet agglutination by anti-glycoprotein II b/III a complex monoclonal antibody.

To characterize the nature of EDTA-induced platelet agglutination, the spontaneous release of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) was examined during EDTA-induced platelet agglutinations. A slight release of beta-TG and PF4 was observed when EDTA-anticoagulated whole blood from cases with EDTA-induced platelet agglutination was kept for 60 minutes, whereas a high spontaneous release of these proteins was found from normal blood anticoagulated with EDTA. These findings imply that EDTA-dependent platelet agglutinin may stabilize the platelet membrane surfaces. Secondly, we found that pretreatment of fresh blood with anti-glycoprotein (GP) II b/III a complex monoclonal antibody dramatically reduced EDTA-induced platelet agglutinations. This study indicated that the binding sites of EDTA-dependent antibody might be GP II b/III a complex. The use of an anti-GP II b/III a complex monoclonal antibody may be useful in avoiding analytical errors in some cases with EDTA-induced pseudothrombocytopenia.

Adenosine Diphosphate↗
PubMed1994

Direct projections from the entopeduncular nucleus to the lower brainstem in the rat.

The present study reports the existence of projection fibers from the entopeduncular nucleus to the superior colliculus and lateral parts of the pontobulbar tegmental regions (so-called lateral tegmental field) in the rat, suggesting that the entopeduncular nucleus may control eye-head and orofacial movements via these projection fibers. The anterograde axonal tracing with Phaseolus vulgaris-leucoagglutinin has revealed that the entopedunculotectal fibers terminate, bilaterally, with an ipsilateral predominance, in the deep layers of the superior colliculus through its rostral one-third level and that the entopedunculotegmental fibers terminate, bilaterally, with an ipsilateral predominance, in the parabrachial area, reticular formation surrounding the trigeminal motor nucleus, and parvicellular, dorsal, and ventral reticular nuclei. The cells of origin of the entopedunculotectal and entopedunculotegmental projections have been identified by retrograde axonal tracing with Fluoro-Gold and cholera toxin B subunit. The entopedunculotectal or entopedunculotegmental fibers originate, respectively, from the dorsal or ventral part of the entopeduncular nucleus. Additionally, a series of fluorescent retrograde double-labeling experiments with Fast Blue and Diamidino Yellow have indicated that single entopeduncular nucleus neurons projecting to the superior colliculus or lateral tegmental field often send their axon collaterals to the lateral habenular nucleus. The entopedunculotectal fibers are assumed to control head movements, which may be provoked via the tectospinal fibers, and further to participate in eye movements as the nigrotectal fibers that have been known to arise from the substantia nigra pars reticulata to end in the deep layers of the superior colliculus primarily through its caudal two-thirds level. The entopedunculotegmental fibers are presumed to be involved in control of orofacial movements, because the sites of termination of the entopedunculotegmental fibers correspond well with the reported areas of distribution of premotor interneurons for the trigeminal motor, facial, and hypoglossal nuclei.

Amidines↗
PubMed1994

Photodynamic therapy and/or external beam radiation therapy for roentgenologically occult lung cancer.

BACKGROUND AND METHODS: Thirty-nine roentgenologically occult lung cancers in 29 patients were treated using photodynamic therapy (PDT) and/or thoracic radiotherapy (TRT) from January 1986 to March 1992. With the exception of one mixed-tumor case, all were squamous cell carcinomas. RESULTS: Initial PDT achieved complete responses in 25 of 39 (64%) of the cancers. Of the remaining 14 cancers that showed less than complete response (CR), 10 of the 14 (71.4%) showed a CR when subsequently treated with TRT, yielding an overall CR rate of 89.7% for cancers treated. Although nine patients experienced recurrences, six of these had CR when treated with PDT and/or TRT. To date, 22 patients are alive. Causes of death in the patients enrolled in this study are as follows: pyothorax (2); heart failure due to pulmonary hypertension (1); chronic respiratory insufficiency (1); subsequent primary brain cancer (1); and subsequent primary lung cancer (1). Only one died of primary lung cancer. CONCLUSIONS: These findings suggest that PDT and/or TRT may be used as an alternative to surgery in the treatment of selected patients with roentgenologically occult lung cancer.

Adult↗
PubMed1994

Direct projections from the deep layers of the superior colliculus to the subthalamic nucleus in the rat.

Direct projections from the superior colliculus to the subthalamic nucleus were found in the rat in antero- and retrograde tracing experiments; these projections arose mainly from the deep layers of the superior colliculus at its middle to caudal levels. The present findings suggest that signals from the deep layers of the superior colliculus may modulate the basal ganglia activity during orienting behavior.

Animals↗
PubMed1994

Direct projections from the non-laminated divisions of the medial geniculate nucleus to the temporal polar cortex and amygdala in the cat.

The medial geniculate nucleus (MG) is well known to send projection fibers not only to the auditory cortex, but also to the limbic structures of the forebrain including the perirhinal cortex and amygdala. In the cat, the non-laminated portions of the MG are also known to project to the amygdala, as well as to the auditory cortical areas surrounding the primary auditory area. On the other hand, projections from the non-laminated MG to the limbic cortical areas have not so far been studied systematically. Thus, in the present study, direct projections from the non-laminated portions of the medial geniculate nucleus to the temporal polar cortex and amygdala were examined in the cat by retrograde and anterograde tract-tracing techniques. The temporal polar cortex is the ventral polar region of the posterior sylvian and posterior ectosylvian gyri, which is located dorsal to the posterior rhinal sulcus and includes the ectorhinal area. After injection of cholera toxin B subunit into the temporal polar cortex, retrogradely labeled neurons were seen in the caudal two-thirds of the medial geniculate nucleus ipsilateral to the injection; they were distributed in the non-laminated portions of the MG (the dorsal and medial divisions and the ventromedial part of the ventral division), but not in the laminated portion (the principal part of the ventral division). These findings were confirmed by injecting Phaseolus vulgaris leucoagglutinin into each division of the MG. After the injection into each non-laminated division, terminal labeling was observed in the temporal polar cortex. Terminal labeling was further found in the lateral amygdaloid nucleus ipsilateral to the injection. Then, cholera toxin B subunit was injected into the lateral amygdaloid nucleus; retrogradely labeled neurons were observed ipsilaterally in the non-laminated portions of the MG, as well as in the temporal polar cortex. The results indicate that the non-laminated portions of the MG send projection fibers to the temporal polar cortex and lateral amygdaloid nucleus, and that the non-laminated portions of the MG and temporal polar cortex give rise to overlapping projections to the lateral amygdaloid nucleus. These connections appear to constitute neuronal links in "emotional" and/or "motivational" circuitry in the forebrain.

Amygdala↗
PubMed1994

Juvenile variant of Schimke immunoosseous dysplasia.

We report on a 16-year-old girl with spondyloepiphyseal dysplasia, nephrotic syndrome, lymphopenia, and signs of defective cellular immunity. The manifestations are very similar to those reported by Spranger et al. [1991: J. Pediatr 119: 64-72] as Schimke immunoosseous dysplasia, except for age of onset. In Schimke immunoosseous dysplasia, growth retardations as an initial symptom is noted in early childhood and about 1 year after onset of progressive proteinuria. In our case the skeletal abnormality was noted at age 10 years as dislocation of the hip joints and the diagnosis of nephrotic syndrome was made at age 16 years. The findings strongly suggest that our patient has a juvenile variant of Schimke immunoosseous dysplasia.

Adolescent↗
PubMed1994

Dopamine depletion in nigrostriatal neurons in the genetically diabetic rat.

Employing tyrosine hydroxylase (TH) immunohistochemistry, we have revealed that the enzyme is depleted in nigrostriatal neurons in the genetically diabetic BB Wistar (BBWd) rat. A similar, but much less marked reduction in TH immunoreactivity occurred in the mesolimbic dopamine system, which arises from the ventral tegmental area and terminates in the nucleus accumbens. The projection to the olfactory tubercle appeared unaffected. Since the decreased levels of dopamine in the mesencephalic dopamine systems could not be restored under insulin-controlled conditions, the impairment of dopamine biosynthesis in the BBWd rat may be genetically programmed.

Animals↗
PubMed1994

Formation and resolution of brain edema associated with brain tumors. A comprehensive theoretical model and clinical analysis.

The purpose of this study is to quantify the relative contribution of the mechanisms in the absorption of edema fluid. The convection/diffusion and the comprehensive bulk flow model were applied for the finite element analysis of peritumoral brain edema. For clinical analysis, 90 meningiomas studied by MRI were selected. Serial CT scan and MRI were performed at 0, 2, 4, 6 hours after injection of Iopamidol or Gadpenteic acid respectively. Then the tracer distributions in the edematous brain was analyzed. The tracer movement in the brain is well represented by the convection/diffusion equation. The absence of the preferential fluid flow directing toward the ventricle indicates that a limited role of CSF sink action into the ventricle. From capillary surface area (240 cm2/g brain), capillary hydraulic conductivity (1.8 x 10(-8) ml/cmH2O/cm2/min) and the simulated average tissue pressure of 9.8 mmHg, maximum absorption rate into capillaries was estimated to be 0.003 ml/h/cm3 brain tissue. Considering the limited role of edema fluid clearance into the ventricle, the results indicate a possible role of subarachnoid CSF space for the clearance of edema fluid. The clearance of edema fluid into subarachnoid CSF space should be studied quantitatively. Finally, unification of the convection/diffusion and the comprehensive bulk flow model will provide a more quantitative analysis of edema formation and resolution by using MRI and tracer studies.

Blood-Brain Barrier↗
PubMed1994

Chronic intramedullary infusion of interleukin-1 alpha increases bone mineral content in rats.

Interleukin-1 (IL-1) is known to have a potent bone-resorbing activity in vitro, however, results from in vivo studies are conflicting. We performed experiments with the continuous infusion of recombinant IL-1 alpha directly into the femoral bone marrow of rats for 2 weeks and examined its effects on bone by soft X-ray photographs, bone mineral assessment, and histological examination. Infusion of IL-1 alpha at doses greater than 1 microgram/ml (0.6 ng/hour) caused sclerosis around the infusion site on soft X-ray photographs, and the bone mineral content of IL-1 alpha infused femora was increased significantly. Histologically, extensive periosteal bone formation was observed around the infusion site and small mononuclear cells replaced the normal fat tissue. Infusion of prostaglandin E2 alone produced intramedullary bone formation more extensively. Simultaneous infusion of IL-1 alpha and indomethacin (10(-3) M; 179 ng/hour) inhibited the increase of bone mineral content (BMC) induced by IL-1 alpha. Thus, the chronic intramedullary administration of IL-1 alpha stimulates bone formation, especially in the periosteum, and increases BMC in intact rats.

Animals↗