Biomedical subjects

R Tanaka

Publications and source records attributed to R Tanaka.

At least 415 records · Page 23Linked to original sources

PubMed1993

[Seven patients with hyperparathyroid crisis: emphasis on prompt parathyroidectomy].

Although hyperparathyroid crisis is rare, the management of this disease remains controversial. We analyzed the clinicopathological features and treatment outcome of this disease to evaluate the significance of prompt parathyroidectomy. Seven patients with an episode of hyperparathyroid crisis who consisted of 2.3% of all surgical patients of primary hyperparathyroidism were treated from 1981 to 1992 at the Department of Endocrine Surgery, Tokyo Women's Medical College. They all showed grave hypercalcemia greater than 15mg/dl, renal dysfunction and gastrointestinal toxicity. Their ages ranged between 33 and 75 years (mean age 49.7 years); two patients were men and five were women. Six patients had an adenoma, and only one had a carcinoma. The weights of the parathyroid tumors ranged between 3.5g and 11g, and ultrasonography disclosed an enlarged parathyroid gland in all patients. All of the seven patients underwent prolonged medical treatment (mean of durations 52 days), but four of them remained with hypercalcemia greater than 15mg/dl. On the other hand, the serum calcium levels of all patients returned to normal within five days after their operations without any surgical complication. Therefore, we recommend prompt parathyroidectomy for hyperparathyroid crisis, since medical treatment requires a prolonged clinical course and sometimes fails to control grave hypercalcemia.

Adenoma↗

PubMed1993

[Characteristics and clinical course of patients with subacute thyroiditis without typical signs and symptoms].

To determine the characteristics and clinical course of patients with subacute thyroiditis (SAT) without typical signs and symptoms, clinical and pathologic records of the patients were reviewed and compared with those of patients with typical SAT. During the past 10 years, 11 of 105 patients with SAT did not have enough typical features for a diagnosis of SAT (atypical SAT). They included one male and 10 females with the average age of 50 years. The incidence of neck pain as the initial symptom in the patients with atypical SAT was low (18%) compared with that in the patients with typical SAT (69%). Of the patients with atypical SAT, 42% had elevated thyroid hormone levels and 46% had suppressed TSH levels, whereas the percentages in the patients with typical SAT were 76% and 85% respectively. Nine of 11 patients were misdiagnosed as having papillary carcinoma by physical examination, and 4 by ultrasonography. However, aspiration cytology could make a precise diagnosis of SAT in 4 patients at the time of clinical diagnosis and 3 other patients after reevaluation. Eight patients were admitted to the hospital under the diagnosis of thyroid cancer and 4 underwent surgical resection. Differential diagnosis between atypical SAT and papillary carcinoma is important, and aspiration cytology could be a conclusive diagnostic tool to avoid unnecessary treatment.

Adult↗

PubMed1993

[Evaluation of the blood flow in lung disease with color Doppler flow imaging].

Blood flow within the lesions was evaluated in 6 patients of lung cancer and in 4 patients with pulmonary tuberculosis with color Doppler flow imaging. Three different signal types were noted: pulsatile signal was detected in all patients with lung cancer and in 2 patients with pulmonary tuberculosis, continuous signal was only detected in 3 patients with lung cancer, triphasic signal was detected in 4 patients with pulmonary tuberculosis and in 2 patients with lung cancer. It was seemed to be that triphasic signal was blood flow signal in peripheral vessel of pulmonary vein and color Doppler flow imaging was useful for evaluation of blood flow patterns in lung disease.

Adenocarcinoma↗

PubMed1993

[Evaluation of the blood flow in tumors before and after irradiation with color Doppler flow imaging].

The blood flow in tumors of three patients with lung cancer, cancer in oral cavity and metastatic lymphnode was respectively evaluated before and after irradiation with color Doppler flow imaging. The arterial pulsating flow in lung cancer disappeared after 30 Gy irradiation and that in cancer of oral cavity disappeared after 15 Gy irradiation with intraarterial infusion chemotherapy. But the arterial pulsating flow in metastatic lymphnode was detected during irradiation and disappeared after 40 days post- irradiation. Therefore color Doppler flow imaging seemed to be useful for evaluation of the blood flow in tumors before and after irradiation.

Aged↗

PubMed1993

Characterization of protein kinase C activities in postsynaptic density fractions prepared from cerebral cortex, hippocampus, and cerebellum.

Protein kinase C (PKC) activities, especially, substrates and PKC isozymes, associated with postsynaptic density (PSD) fractions isolated from rat cerebral cortex, hippocampus, or cerebellum were investigated. The 17k M(r) major substrate for PKC was associated with PSD fractions prepared from cerebral cortex and hippocampus, and several substrates including 18k M(r) protein were associated with PSD fraction isolated from cerebellum. The content of 17k M(r) substrate was extremely low in the PSD fraction prepared from cerebellum. PKCs-beta and gamma were associated with PSD fractions and PKC-alpha was virtually absent in the fraction prepared from the three different regions of the brain. All of PKCs-alpha, beta, and gamma were associated with synaptosome fractions. The 36k M(r) bands immunoreactive with anti-PKC-beta antibody, probably degradation products of native PKC-beta, were detected in both the PSD and synaptosome fractions from the three regions, and the ratio of the degradation fragments to native PKC molecule was higher in PSD fractions than in synaptosome fractions. The results suggest postsynaptic roles of PKCs-beta and gamma and involvement of proteolytic activation of PKC-beta in the postsynaptic signal processing.

Amino Acid Sequence↗

PubMed1993

Expression of vascular endothelial growth factor in capillary hemangioblastoma.

The gene expression of vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen, was examined in capillary hemangioblastomas which are composed of abundant microvasculature and primitive angiogenic elements represented by stromal cells. Northern blot and in situ hybridization analyses showed that the VEGF mRNA was highly expressed in the stromal cells, but not in the endothelial cells. Reverse transcription/PCR analysis revealed that the VEGF mRNA species expressed in the stromal cells were the shorter splicing forms, VEGF121 and VEGF165, which are potent to be secreted from cells and the longer splicing form, VEGF189, which is predominantly cell-associated. Our findings suggest that VEGF secreted from the stromal cells plays an important role in the endothelial cell proliferation in capillary hemangioblastomas.

Base Sequence↗

PubMed1993

[Usefulness of color Doppler flow imaging for blood flow in salivary gland].

We investigated the arterial and venous blood flow response in submandibular gland to secretory stimulation using color doppler flow imaging in six normal subjects. During examination secretory stimulation by lemon juice was used. The arterial and venous flow markedly increased after secretory stimulation in all normal subject. It was seemed to be that color doppler flow imaging was of value in evaluation of the blood flow in salivary gland.

Adult↗

PubMed1993

Isolation and characterization of a novel type of glycosphingolipid from Neanthes diversicolor.

Five glycosphingolipids were obtained in the pure state from the marine annelid, Neanthes diversicolor. Final isolation of the individual compound was achieved by means of preparative HPLC with a reversed phase column in a recycling mode. They were assigned the structures, 1-O-beta-D-(6-O-[2'-(trimethylammonio)- ethylphosphoryl])galactopyranosyl, -N-hexadecanoyl-(4E,8E)-sphingadiene (1), -N-hexadecanoyl-(4E)-sphingenine (2), -N-heptadecanoyl-(4E)-sphingenine (3), -N-octadecanoyl-(4E)-sphingenine (4) and -N-hexadecanoyl-sphinganine (5). It is noted that they are the monogalactosyl ceramides carrying the phosphocholine group in the galactose moiety, and that one of them contains an odd numbered fatty acid residue.

Animals↗

PubMed1993

[Relative lymphopenia in Cushing's syndrome].

The differential white blood cell (WBC) count often reveals relative lymphopenia in Cushing's syndrome and may be a clue to the discovery of the ailment. However, the incidence of this finding has rarely been reported in the literature. We conducted a study on 40 patients with Cushing's syndrome due to adrenocortical adenoma to evaluate the diagnostic implications of relative lymphopenia. Total WBC count, differential WBC count, basal level of plasma cortisol, urinary excretion of free cortisol and thyroid function were evaluated preoperatively. We also investigated the differential WBC count in 40 patients with thyroid tumors matched for age and sex with the Cushing's syndrome patients. The proportion of lymphocytes among WBCs was also compared between the two groups. The proportion of lymphocytes among WBCs was significantly lower in the patients with Cushing's syndrome (19.4 +/- 10.8%) than in those with thyroid tumors (42.3 +/- 9.5%, mean +/- SD, p < 0.05). The incidence of relative lymphopenia was high (82.5%) as well as that of increased urinary excretion of free cortisol (85.3%) in Cushing's syndrome patients. The low T3 syndrome was frequently seen (73.9%), whereas the incidences of leukocytosis and an increased level of basal plasma cortisol were relatively low (42.5% and 47.5%, respectively). Relative lymphopenia provides useful information for diagnosing Cushing's syndrome since it has high sensitivity although it should be kept in mind that its specificity is low.

Adenoma↗

PubMed1993

Bcl-2 gene is highly expressed during neurogenesis in the central nervous system.

An analytical method for quantitation of the RNA transcripts of murine bcl-2 gene was developed. The PCR products from bcl-2 alpha and bcl-2 beta mRNA were fluorometrically analyzed and their specific contents were calculated by the internal standard method. Both bcl-2 mRNAs in adult mice were transcribed at the highest level in the thymus and at a comparable level in the spleen. Aside from the immune system, the brain gave the most abundant levels of the bcl-2 mRNAs. The ratios of bcl-2 beta mRNA to bcl-2 alpha mRNA in the thymus and spleen were significantly higher than those in other tissues. During development of the brain, the bcl-2 alpha and bcl-2 beta mRNA levels were highest on embryonic day 15, and about two and three times higher than those of adult, respectively. The results suggest that the bcl-2 gene functions to regulate development and survival of neurons in the central nervous system.

Animals↗

PubMed1993

The cellular basis for the blunted response to beta-adrenergic stimulation in supraventricular tachycardia-induced cardiomyopathy.

Chronic tachycardia-induced dilated cardiomyopathy causes increased plasma catecholamines and alterations in beta-adrenergic responsiveness in vivo. However, whether isolated myocyte contractile response to beta-stimulation is directly affected by the development of cardiomyopathy and how these changes are related to alterations in the beta-adrenergic receptor system remain unclear. Accordingly, isolated myocyte function and beta-adrenergic responsiveness were examined in two groups of 12 pigs each: sham controls, and with supraventricular tachycardia induced cardiomyopathy (SVT; pace: 240 beats/min, 3 weeks). Isolated LV myocyte percent and velocity of shortening were examined at baseline, with isoproterenol (2-100 nM), and forskolin (0.1-4 microM). Baseline percent and velocity of shortening were significantly reduced with SVT compared to controls (1.6 +/- 0.1 vs 5.4 +/- 0.2%, 56 +/- 3 vs 25 +/- 1 micron/s, respectively, P < 0.05). The maximal increase in the percent and velocity of shortening with isoproterenol was significantly blunted in the SVT myocytes compared with controls (3.2 +/- 0.4 vs 9.7 +/- 1.0%, 48.0 +/- 5.3 vs 122.6 +/- 15.5 micron/s, respectively, P < 0.05). Similarly, maximal increase in the percent and velocity of shortening with forskolin were reduced with SVT compared to controls (3.3 +/- 0.4 vs 10.5 +/- 0.6%, 50.7 +/- 6.4 vs 120.1 +/- 9.7 micron/s, respectively, P < 0.05). In order to determine the cellular basis for these changes in beta-adrenergic response, myocyte structure, sarcolemmal beta-receptor density and affinity, and adenylate cyclase activity were examined. There was a 25% reduction in beta-receptor number with SVT (P < 0.05) but no change in affinity. Basal adenylate cyclase activity was lower with SVT compared to control (46 +/- 3 vs 77 +/- 10 pmol cyclic AMP/mg/min, P < 0.05), and exhibited a blunted response with both isoproterenol (1 mM; 106 +/- 19 vs 203 +/- 26 pmol cyclic AMP/mg/min, P < 0.05) and forskolin (100 microns: 209 +/- 35 vs 378 +/- 58 pmol cyclic AMP/mg/min, P < 0.05). Finally, myofibrillar content within SVT myocytes was significantly reduced from controls (43 +/- 7 vs 63 +/- 4%, P < 0.05). In summary, the cellular basis for the depressed myocyte contractile response to beta-stimulation with tachycardia induced SVT are probably due to several factors which include: decreased expression of beta-receptors, alterations in beta-receptor transduction, reduced adenylate cyclase activity, and decreased myocyte contractile protein content.

Adenylyl Cyclases↗

PubMed1993

Correlation of MRI and clinical features in meningeal carcinomatosis.

Ten patients with meningeal carcinomatosis associated with nonhaematological neoplasms were examined: six with breast, two with gastrointestinal and one with lung cancer, plus one with a tumour of unknown origin. Cytology was positive in all but one. The patients were classified into four groups according to the gadolinium-enhanced MRI (Gd-MRI) appearances: group 1 had pure leptomeningeal carcinomatosis, group 2 dural carcinomatosis, group 3 spinal leptomeningeal carcinomatosis, and group 4 had normal Gd-MRI except for hydrocephalus. In group 1, Gd-MRI showed diffuse enhancement of the subarachnoid space, including the cisterns around the midbrain, the sylvian fissures, or cerebellar and cerebral sulci. In group 2, Gd-MRI showed diffuse, thick, partially nodular enhancement of the dura mater. No leptomeningeal or subependymal enhancement was evident. In group 3, nodular masses were seen only in the spinal canal. In group 4, no definite evidence of meningeal carcinomatosis was demonstrated on contrast-enhanced CT (CE-CT) or Gd-MRI. The median survival time was 2.0 months in group 1, 1.0 month in group 3, and 4.5 months in group 4, but the two patients in group 2 were alive 10 and 15 months after a definite diagnosis of meningeal carcinomatosis was made. In all patients examined by both CE-CT and Gd-MRI, the latter was superior for identification of meningeal carcinomatosis. Hydrocephalus in an important indirect sign of leptomeningeal carcinomatosis, but was not seen in patients with dural carcinomatosis despite the presence of increased intracranial pressure.

Aged↗

PubMed1993

Long-term ciclosporin treatment in children with steroid-dependent nephrotic syndrome.

We report the effect of 18-month ciclosporin (CS) treatment in 19 children with steroid-dependent frequently relapsing nephrotic syndrome. CS was started at 3-5 mg/kg per day after remission with steroid therapy, was adjusted to maintain a trough blood level of between 200 and 600 ng/ml and was administered for 6 months (high-dose CS). Then, the dosage of CS was decreased and 2.5 mg/kg per day was administered for the subsequent 12 months (low-dose CS). Only 2 patients had relapses during the initial 6 months of CS therapy. Eight patients had infrequent relapses, 4 had frequent relapses and 7 had no relapses during the 12 months of low-dose CS. Not only did continuation of CS at a lower dosage decrease the relapse rate, it also reduced steroid toxicity, allowed increased growth in 16 of the 19 patients and also decreased obesity scores in 12 of these patients. All of the side-effects that occurred during the 18-month period of CS treatment were reversible and none was serious enough to necessitate discontinuation of therapy. Our 18-month CS treatment was helpful in preventing relapses and reducing steroid toxicity in children with steroid-dependent frequently relapsing nephrotic syndrome.

Adolescent↗

PubMed1993

The isolation of Cryptococcus neoformans from pigeon droppings and serotyping of naturally and clinically sourced isolates in China.

This is the first report on the isolation of Cryptococcus neoformans from pigeon droppings in China and their serotypes. C. neoformans colonies which produced brown colonies on caffeic acid-cornmeal agar were found in Twenty-five out of thirty-six samples of pigeon droppings. Fifty-one colonies randomly picked from the positive samples were identified as C. neoformans by a commercially available kit for carbon source assimilation test and Christensen's urea agar. Forty (78%) out of the 51 strains were serotyped as A and 11 (22%) as AD. At the same time, seventeen out of nineteen clinical isolates were serotyped as A and 2 as B. There are three findings in our results. One is that only C. neoformans var. neoformans strains could be isolated from pigeon droppings, although the variety gattii strains were found in the clinical isolates obtained in the same geographic site in China. The second is that serotype A strains were most frequently seen in natural and clinical materials in the southeast part of China, and serotype AD strains were isolated in pigeon droppings but not in clinical materials. The third is that the coexistence of serotype A and AD cells of C. neoformans strains in same samples of pigeon droppings were observed.

Animals↗

PubMed1993

An autopsy case of intracranial hemorrhage during tissue plasminogen activator infusion.

We describe an autopsy case of severe intracranial hemorrhage which occurred during the infusion of tissue plasminogen activator (t-PA) for acute myocardial infarction. A 75-year-old man was admitted with substernal chest pain of 3-h duration and electrocardiographic changes consistent with an acute inferior myocardial infarction. Physical examination was unremarkable, except for an initial blood pressure reading of 160/96 mmHg. The patient received 3,000 IU intravenous heparin followed by a 2.4 x 10(6) IU bolus dose of tissue plasminogen activator (t-PA) (Alteplase). This was followed by a drip infusion of 21.6 x 10(6) IU of t-PA over 1 h (total dose 41 mg). Thirty minutes after the infusion of t-PA was initiated, the patient suddenly lost consciousness and began to have violent convulsions, followed by cardiac arrest. Autopsy revealed massive hemorrhage in the bilateral cerebrum and brain stem. To our knowledge, this is the first case of sudden death during t-PA infusion therapy.

Aged↗

PubMed1993

Prognosis of intracranial germ cell tumours: effectiveness of chemotherapy with cisplatin and etoposide (CDDP and VP-16).

A co-operative study for patients with intracranial germ cell tumours was performed to analyze their prognosis and the effectiveness of Cisplatin/Etoposide (CDDP/VP-16) chemotherapy. A total of 46 patients; 30 primary and 16 recurrent cases were registered from 15 participating neurosurgical institutions in Japan. Based on histological criteria and tumour markers, they were classified into three groups; germinoma, germinoma with syncytiotrophoblastic giant cell (STGC), and non-germinomatous malignant tumour. Sixteen patients were treated with CDDP/VP-16 chemotherapy alone and the other 30 patients were treated by a combination of surgery and/or radiation in addition to chemotherapy. Eleven out of 13 patients (85%) with germinoma showed a complete (n = 10) or partial (n = 1) response to CDDP/VP-16 chemotherapy even if their tumours were recurrent and there was evidence of CSF dissemination. For the germinoma with STGC and non-germinomatous malignant tumour, a high response rate; 100% for the former and 78% for the latter, could also be achieved in both the primary and the recurrent cases except in those cases of immature teratoma. Their survival times were still different between them. Two-year survival was 50% in germinoma with STGC and 48% in non-germinoma, while it was 88% in germinoma cases.

Adolescent↗

PubMed1993

Correlation between intravascular pressure and risk of hemorrhage due to arteriovenous malformations.

The correlation between intraoperative pressure levels measured in the feeding arteries and in the draining veins, and the risk of hemorrhage from arteriovenous malformations (AVMs) is discussed. Feeding artery pressure (FAP) was significantly higher in AVMs with hemorrhage (57 +/- 11 mmHg) than in AVMs without hemorrhage (38 +/- 4), and draining vein pressure (DVP) in the former (24 +/- 5) was significantly higher than that in the latter (13 +/- 5). FAP and DVP were inversely related to the number of draining veins and size of the AVMs. The present study suggests that a high FAP and a high DVP may contribute to the development of hemorrhage from AVMs, and supports previous reports that small AVMs and AVMs with only one draining vein are susceptible to hemorrhage.

Blood Pressure↗

PubMed1993

Immunological analysis of the rats with anterior hypothalamic lesions.

We have previously identified the suppression of lymphocyte blastogenesis and the acceleration of growth of subcutaneous tumors by bilateral anterior hypothalamic lesions in rats. The present study was performed to clarify the changes in lymphocyte subsets and natural killer (NK) activity after making the lesions. The influence on immunological memory was also studied. The CD4/CD8 ratio of peripheral blood lymphocytes and spleen cells, T cell receptor alpha beta-positive cells of the thymocytes and NK activity of the spleen cells decreased significantly. Major histocompatibility complex (MHC) antigen expression on RBL-1 cells injected intraperitoneally into pre-immunized rats was also suppressed. These results suggest that the anterior hypothalamus has some influences on the control of the cellular immunological functions at the peripheral level, on the maturation of T cells at the level of thymus and on the antigen recognition by T cell receptors and MHC antigens.

Animals↗