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Biomedical subjects

N Takeda

Publications and source records attributed to N Takeda.

At least 397 records · Page 22Linked to original sources
PubMed1992

Pseudo-adrenal incidentaloma: magnetic resonance imaging in a patient with para-adrenal Castleman's disease.

We report a case of para-adrenal angiofollicular lymph node hyperplasia (Castleman's disease) of the hyaline-vascular type. The mass could not be differentiated from an adrenal tumor by ultrasonography and computed axial tomography (CT). However, magnetic resonance imaging (MRI) suggested the possibility of an extra-adrenal origin of the mass. The intensity of the mass by MRI was homogeneous and of a higher intensity in the T2-weighted image than in the T1-weighted image, a finding similar to lymphadenopathy, lymphatic tumorous mass or metastatic tumor of the lymph node. Ultrasonography, CT and MRI may not be useful in characterizing Castleman's disease, but MRI was useful to distinguish asymptomatic para-adrenal masses from those of adrenal origin.

Adrenal Gland Neoplasms↗
PubMed1992

The effects of angiotensin converting enzyme inhibitors and the role of the renin-angiotensin-aldosterone system in J-2-N cardiomyopathic hamsters.

In recent years, captopril has attracted considerable clinical attention as an agent for use in treating heart failure. We administered 15 mg/kg of captopril or 1.5 mg/kg of enalapril to 5-week-old J-2-N cardiomyopathic hamsters for 10 or 15 weeks, and investigated the roles of the renin-angiotensin-aldosterone and kallikrein-kinin systems in the onset and progress of cardiomyopathy. In the untreated group, serum creatine kinase levels increased in accordance with the progression of cardiomyopathy, but this increase was markedly inhibited by the administration of captopril. The rise in serum aldolase levels was similarly inhibited. Serum malondialdehyde levels were significantly reduced by the administration of captopril. ECG findings and the ventricular myosin isoenzyme pattern were also markedly improved by captopril. The improvement in all these parameters was less with enalapril. These differences between captopril and enalapril suggest that increases in tissue bradykinin and vasodilatory prostaglandins may play an important role in the beneficial effects of captopril.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1992

Chalcone tetramers, lophirachalcone and alatachalcone, from Lophira alata as possible anti-tumor promoters.

Two chalcone tetramers were isolated as inhibitors of Epstein-Barr virus (EBV)-activation induced by a tumor promoter, teleocidin B-4, from a medicinal plant in tropical west Africa, Lophira alata (Ochnaceae). One of them was identified as lophirachalcone. The other, named alatachalcone, was new, and the structure was determined by spectral properties. Both compounds also showed potent inhibitory activities against teleocidin B-4-induced inflammation on mouse ear. In an initiation-promotion experiment on mouse skin, alatachalcone (16 nmol) significantly inhibited tumor promotion caused by 12-O-tetradecanoylphorbol-13-acetate (TPA, 1.6 nmol).

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1992

Characterization of insulin receptors in the bovine adrenal cortex and medulla.

In order to identify insulin receptors in the bovine adrenal cortex and medulla, we have studied 125I-porcine insulin binding to the membrane preparations from the bovine adrenal cortex and medulla. 125I-porcine insulin bound not only to the bovine adrenal cortex but to the medulla in time-, temperature-, and pH-dependent manners. The maximum levels of 125I-porcine insulin binding in the two tissues were observed at 4 degrees C for 24 h of incubation, and its optimum pH ranged from 7.6 to 8.0. Under these conditions, at tracer concentration of porcine insulin (200 pg/ml), 10.4% and 6.6% of 125I-porcine insulin added to each reaction tube bound specifically to 10(5) x g-pellet fractions (microsomal membrane) from the cortical tissue (0.3 mg of protein) and from the medullary tissue (2 mg of protein), respectively. 125I-porcine insulin binding was observed predominantly in the microsomal membrane from the bovine adrenal cortex, and in a 15,000 x g- pellet fraction (synaptosomal membrane) from the bovine adrenal medulla. Scatchard analysis of binding data yielded curvilinear plots in each tissue. Analysis of curvilinear plots based on two sites model revealed similar affinity constant between the cortex and medulla. Receptor concentration of the cortex was several times higher than that of the medulla. In the two bovine adrenal tissues, human proinsulin and insulin-like growth factor I (IGF-I) had about 1/100 potency compared to porcine insulin in displacing 125I-porcine insulin binding. Porcine glucagon added with concentration up to 10(-6) M did not inhibit 125I-porcine insulin binding to both the cortex and the medulla.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex↗
PubMed1992

Prognosis of primary malignant lymphoma of the central nervous system--a retrospective study of 32 cases.

A retrospective analysis of 32 patients with primary malignant lymphoma of the central nervous system (CNS) diagnosed between 1976 and 1989 investigated treatment results and recurrence patterns. All patients showed either complete or partial regression of the tumor after initial treatment, mainly radiation therapy with adjuvant chemotherapy. The mean dose of whole-brain irradiation was 40.9 Gy and that of booster was 14.4 Gy. Most patients had tumor recurrence. The median time to recurrence from completion of the treatment was 5 months. The 1- and 5-year survival rates were 50.0 and 17.7%, respectively, and the overall median survival time was 11 months. Most tumors had multiple recurrences at the primary site and other regions of the CNS, and tended to recur in the periventricular region and the cerebrospinal fluid space. Spinal metastasis occurred in five cases. The importance of good control of the primary lesion and active maintenance therapy for the whole CNS is emphasized.

Adult↗
PubMed1992

Effects of capsaicin desensitization on nasal allergy-like symptoms and histamine release in the nose induced by toluene diisocyanate in guinea pigs.

Intranasal application of toluene diisocyanate (TDI) induced nasal allergy-like symptoms of sneezing and watery rhinorrhea and decreased the histamine content of the nasal mucosa in guinea pigs. However, in the animals pretreated with capsaicin (capsaicin desensitization) before sensitization with TDI, nasal allergy-like symptoms were not induced. Capsaicin desensitization also inhibited histamine release in the nasal mucosa induced by TDI. These findings suggest that antidromic impulses of capsaicin-sensitive sensory nerves stimulated by TDI cause histamine release from mast cells in the nasal mucosa, resulting in nasal discharge and sneezing in guinea pigs. Thus neurogenic inflammation via an axon reflex in the nose may contribute to the pathogenesis of vasomotor rhinitis.

Animals↗
PubMed1992

Vestibular, central and gastral triggering of emesis. A study on individual susceptibility in rats.

Using kaolin intake as a behavioral index of emesis in rats, we examined the relationship between susceptibility to motion sickness and to emesis induced by apomorphine or copper sulfate. Rats showed a wide variation in susceptibility to motion sickness. Significant positive correlations were found between susceptibility to motion sickness and to emesis induced by intraperitoneal administration of apomorphine and by oral administration of copper sulfate. Motion, apomorphine and copper sulfate induce emesis through different receptors, so these findings suggest that the sensitivity of a common locus of emesis, presumably the emetic center in the brain stem, is one determinant of individual differences in susceptibility to motion sickness.

Animals↗
PubMed1992

Temporal lobe tumor demonstrating ganglioglioma and pleomorphic xanthoastrocytoma components. Case report.

The case is reported of a 16-year-old boy with a left temporal lobe tumor composed of a ganglioglioma and a pleomorphic xanthoastrocytoma. Histologically, the tumor had two different components. One component involved the cortex of the left posterior temporal lobe and showed an aggregation of neuronal cells with an astroglial stroma. Ultrastructurally, numerous dense-cored vesicles, diagnosed as ganglioglioma, were found in the neuronal cells. The other component involved the adjacent cortex and white matter of the left anterior temporal lobe and the surrounding subarachnoid space. This was composed of pleomorphic cells with many multinucleated giant cells and occasional foamy cells. Most of the tumor cells were positive for glial fibrillary acidic protein. These features correspond well to earlier descriptions of pleomorphic xanthoastrocytoma. At 24 months following total tumor extirpation, the patient is alive and has had no evidence of tumor recurrence.

Adolescent↗
PubMed1992

[A case of metastatic carcinoma to the retina].

The authors report a case of metastatic carcinoma to the retina. The patient was a 61-year-old man who had an operation for a well-differentiated adenocarcinoma of the rectum. Ophthalmoscopic examination disclosed a single, white, elevated mass lesion surrounded by serous retinal detachment located in the upper part of the macula of the right eye. A few retinal hemorrhages existed around the lesion. Fluorescein angiography revealed partially obscured retinal vessels due to compression by the tumor and arteriovenous anastomosis. Postmortem pathologic examination confirmed metastases to the brain, lung and retina. Microscopic examination showed a retinal lesion and tumor cells in the right eye. Tumor cells, similar to the carcinoma of the rectum, were present only in the neurosensory retina and did not invade the pigmented epithelium or choroid.

Adenocarcinoma↗
PubMed1992

[An analysis on prognostic significance of histopathologic risk factor in uterine endometrial carcinoma].

Prognostic risk factors in histopathologic findings were analyzed in the data for one hundred and thirteen patients with uterine endometrial carcinoma who were treated surgically. Univariate survival analysis with Kaplan-Meier methods revealed that the nuclear grade (p less than 0.005), lymph-vascular space invasion (p less than 0.005), histologic grade (p less than 0.01) and histologic type (p less than 0.01) correlated with the patient's prognosis. Among surgical FIGO stages II and III, there was similar significance in the correlations in the nuclear grade (p less than 0.05), lymph-vascular space invasion (p less than 0.0001) and histologic type (p less than 0.05), although there was difference (p less than 0.05) only between grade 1 and grade 3 in the histologic grade. Multivariate survival analysis with a proportional hazard regression model showed that the nuclear grade (p less than 0.005) and lymph-vascular space invasion (p less than 0.01) correlated significantly with the prognosis. The hazard ratios with a 95% confidence interval for each of these factors were 19.2 (3.2-115.7) and 16.9 (2.1-135.3), respectively. The 3-year survival rate was 98% for a hazard ratio less than 64.7, and 45% for one more than 67.4, between which there was a significant difference (p less than 0.0001). And univariate survival analysis of this hazard ratio also revealed strong correlations with the patient's prognosis. These results suggest that it is of great importance to adopt the hazard model including such factors as the nuclear grade and lymph-vascular space invasion in estimating the patient's prognosis and proceeding to adequate post-operative therapy for individual patient.

Adenocarcinoma↗
PubMed1991

Coexistence of acetylcholine and calcitonin gene-related peptide in the vestibular efferent neurons in the rat.

An immunocytochemical study combined with the retrograde tracer technique was performed in the rat to assess the vestibular efferent system. All 3 neuron groups which give rise to axons terminating on the vestibular end-organs were cholinergic, i.e., a group dorsolateral to the genu of the facial nerve (DL), a group dorsomedial to this genu (M), and scattered cells in the parvocellular reticular nucleus (PCRt). In addition, we further demonstrated that about 55% of the cholinergic cells in DL had calcitonin gene-related peptide.

Acetylcholine↗
PubMed1991

Pre-column derivatization of sulfa drugs with fluorescamine and high-performance liquid chromatographic determination at their residual levels in meat and meat products.

A rapid, sensitive and selective high-performance liquid chromatographic method is described for simultaneous determination of eight sulfa drugs in meat and meat products using pre-column derivatization with fluorescamine. The drugs are sulfisomidine, sulfadiazine, sulfamerazine, sulfadimidine, sulfamonomethoxine, sulfamethoxazole, sulfadimethoxine and sulfaquinoxaline. The method includes blender extraction of 3-g samples with chloroform, partition with 3 M hydrochloric acid, derivatization with fluorescamine at pH 3.0 and subsequent high-performance liquid chromatographic analysis on a C18 column with fluorescence detection at an excitation wavelength of 405 nm and an emission wavelength of 495 nm. The drugs were separated with a mobile phase of acetonitrile-2% acetic acid (3:5) at 55 degrees C. The average recovery from samples fortified at 0.1 ng/g was 92.6% with a coefficient of variation of 6.2%. The detection limit was 0.01 ng/g for sulfaquinoxaline and 0.005 ng/g for the other seven drugs. The method was field-tested in a survey of 37 samples including beef (five), pork (seven), chicken (seven), ham (five), sausage (eight), bacon (two) and roast beef (three). Sulfadimidine was detected in one pork sample at the level of 0.295 ng/g and in ham at 0.178 ng/g.

Animals↗
PubMed1991

Presence of 2-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline and 1,2-dimethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, novel endogenous amines, in parkinsonian and normal human brains.

2-Methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline and 1,2-dimethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline were identified for the first time as novel endogenous amines in parkinsonian and normal human brains by gas chromatography-mass spectrometry. It is of interest that these tetrahydroisoquinolines are analogues of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) which produces Parkinson's disease.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗