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Biomedical subjects

M Takada

Publications and source records attributed to M Takada.

At least 559 records · Page 31Linked to original sources

The development of laterality in the forebrain projections of midline thalamic cell groups in the rat.

Bilateral forebrain (caudoputamen, nucleus accumbens and frontal cortical areas) injections of two different fluorescent retrograde tracers demonstrated that labeled cells situated in the midline nuclei of the thalamus and midbrain each project only unilaterally to the forebrain, regardless of the laterality of their perikarya. Thus, these intermingling midline perikarya send their axons primarily ipsilaterally and to a lesser degree contralaterally, but never bilaterally to the forebrain. At embryonic day 19, these midline nuclei exist as two bilaterally situated, independent structures, each projecting only ipsilaterally to the forebrain. By postnatal day 2, these perikarya fuse into a single mass on the midline. Upon fusion, many of the perikarya of the two developing subnuclei cross the midline, intermingle with each other, and thus some neurons come to have contralateral forebrain projections. These observations suggest that neurons are able to maintain their axonal projections while migrating short distances.

Amidines↗

A note on the projections of pars compacta neurons within pars reticulata of the substantia nigra in the rat.

The ascending projections of pars compacta (SNc) neurons displaced within the pars reticulata (SNr) of the substantia nigra in the rat were examined using a fluorescent retrograde tracing. Following unilateral injections of a tracer into the striatum, SNc cells within the SNr were retrogradely labeled predominantly in the caudal parts, and to a lesser extent in the rostral portions of the nucleus. These nigrostriatal projections arising from the SNc cells within the SNr were only ipsilateral. Injections of a tracer into the nucleus accumbens (Acc) did not produce any labeling of these displaced SNc cells in contrast with cells in the SNc proper. Given that the SNc neurons within the SNr project only to the striatum but not to the Acc, and that they contain dopamine but not cholecystokinin, they might be involved in the motor but not in the limbic function.

Amidines↗

Somatic labeling of the medial terminal nucleus of the accessory optic system with WGA-HRP injected into the rat occipital cortex.

Neuronal cell bodies in the medial terminal nucleus of the accessory optic system (MTN) were labeled with WGA-HRP which was injected ipsilaterally into the occipital cortex in the rat. We suggest that the label was first transported anterogradely to the pretectal nucleus of the optic tract, then moved transneuronally from axon terminals of occipital cortical neurons to axon terminals of MTN neurons, and finally transported retrogradely to reach cell bodies of MTN neurons.

Animals↗

Phototropism in Hypocotyls of Radish: IV. Flank Growth and Lateral Distribution of cis- and trans-Raphanusanins in the First Positive Phototropic Curvature.

The first positive phototropic curvature induced by a pulse of unilateral white irradiation (0.1 watt per square meter, 30 seconds) of etiolated and de-etiolated Sakurajima radish (Raphanus sativus var hortensis f. gigantissimus Makino) hypocotyls was analyzed in terms of differential growth and growth inhibitor contents of the hypocotyls. In both etiolated and de-etiolated hypocotyls, the growth rates at the lighted sides were suppressed whereas those at the shaded ones showed no change. De-etiolation treatment induced a larger difference between the growth rates at the lighted and shaded sides of the hypocotyls, resulting in a larger curvature of de-etiolated seedlings than of etiolated ones. The contents of growth inhibitors, cis- and trans-raphanusanins, increased in the lighted but not in the shaded halves of the hypocotyls of etiolated seedlings. In de-etiolated seedlings, the two inhibitors increased due to the de-etiolation treatment. When de-etiolated seedlings were exposed to a pulse of unilateral irradiation the level of the two inhibitors remained high along the lighted side for 1 h following the light pulse, whereas at the shaded side the contents of the inhibitors abruptly decreased upon transfer to the dark, the difference between their amounts in the lighted and shaded sides being larger than in etiolated seedlings. Another growth inhibitor, raphanusamide, did not respond to the phototropic stimulus, although its amounts increased by the de-etiolation treatment. These data suggest that cis- and trans-raphanusanins are involved in the first positive phototropic response of radish hypocotyls, and that de-etiolation magnifies the phototropic response through induction of a larger lateral gradient of the raphanusanins in the hypocotyls by the phototropic stimulus.

Journal Article↗

Parathyroid hormone and electrolytes during long-term treatment with allopurinol and thiazide.

We have investigated the composition of plasma and urine in patients with recurrent calcium calculi treated with allopurinol alone, thiazide alone, and both agents together for more than 18 months, and compared the results with those of patients receiving no treatment. In patients treated with allopurinol, both plasma and urinary uric acid were decreased, and plasma parathyroid hormone (PTH) and urinary calcium were increased between 1 and 2 years after treatment. In patients treated with thiazide, plasma calcium was decreased 3 months after treatment but then increased gradually, although the pre-treatment level was not reached. Urinary calcium was decreased 3 months after treatment but returned to pre-treatment levels at 6 and 12 months. Plasma PTH was gradually increased. In patients treated with both allopurinol and thiazide, plasma and urinary uric acid, plasma potassium and urinary calcium were decreased during treatment. Plasma PTH increased gradually during treatment. In patients receiving no treatment, the composition of plasma and urine did not alter during follow-up. The reasons for the changes in urinary calcium and plasma PTH have been discussed.

Adult↗

Fever and acute phase response induced in rabbits by human recombinant interferon-gamma.

1. Intravenous (I.V.) and intracerebroventricular (I.C.V.) injections of human recombinant interferon-gamma (IFN-gamma) produced dose-dependent fevers in rabbits. The fever induced by I.V. injection was monophasic and the maximum elevation occurred 80-110 min after injection. The fever induced by I.C.V. injection was observed from about 20 min after injection and was remarkably prolonged over 4 h. 2. The development of pyrogenic tolerance to IFN-gamma was observed when rabbits were given I.V. injections on 3 successive days. Furthermore, the pyrogenicity of IFN-gamma was significantly attenuated by heating at 60 degrees C for 40 min. The I.V. injection of IFN-gamma enhanced the febrile response induced by endotoxin but had no effect on that induced by endogenous pyrogen. 3. The I.V. injection of a large dose of IFN-gamma (6 x 10(6) units/kg) induced an acute phase response, which included a reduction in plasma concentration of iron and zinc. 4. The present results suggest that IFN-gamma released from lymphocytes is one of the endogenous mediator proteins responsible for producing fever and acute phase response.

Acute-Phase Reaction↗

Separate mechanisms inside and outside the blood-brain barrier inducing metabolic changes in febrile rabbits.

1. We investigated the acute phase response induced by either intravenous (I.V.) or intracerebroventricular injections of bacterial endotoxin or endogenous pyrogen. These caused either monophasic or biphasic fever, and the response includes changes in plasma concentration of iron, zinc, copper, fibrinogen and in circulating leucocyte count.2. The I.V. injection of a small dose of endotoxin or endogenous pyrogen produced a monophasic fever, while a large dose produced a biphasic fever. The ventricular injection of endogenous pyrogen produced a fever similar to the second phase of the biphasic fever.3. The I.V. injection of a small dose of endotoxin or endogenous pyrogen produced a low plasma zinc 8 h after injection, while the ventricular injection of endogenous pyrogen produced a low plasma zinc 24 h after injection. The I.V. injection of a large dose of endotoxin or endogenous pyrogen induced a low plasma zinc 8 and 24 h after injection, suggesting that the hypozincaemia induced by the large dose was mediated by both peripheral and central action of endogenous pyrogen with different time courses.4. The I.V. injection of the small dose did not affect the level of the plasma copper concentration but the I.V. injection of the large dose and the ventricular injection increased it 24 h after injection. It is considered that the plasma copper concentration is mainly controlled by the central action of endogenous pyrogen.5. The changes in the plasma iron and fibrinogen concentration and the circulating white blood cell count induced by the different doses and by the different routes showed very similar patterns, indicating that these are simultaneously controlled by both peripheral and central actions of endogenous pyrogen.6. The present results show that there are two separate mechanisms involved in the acute phase response, one inside and one outside the blood-brain barrier. From the consideration that endogenous pyrogen released from the phagocytic leucocytes induces fever and acute phase response by its action on both the peripheral target organs and the central nervous system, it is suggested that endogenous pyrogen acts both centrally and peripherally, in the same manner as other hormonal agents such as corticosteroids.

Journal Article↗

A possible mode of solubilization of coenzyme Q10 with HCO-60.

The redox level of [14C]coenzyme Q10 solubilized with HCO-60 in the livers of guinea pigs at 24 h after intravenous injection was approximately 1/4 (18.2% vs. 63.4%) of that of [14C]coenzyme Q10 solubilized with ethanol-water (1:5 by vol). Further, the redox level of coenzyme Q10 (Q10) solubilized with HCO-60 or ethanol-water was 20.2 or 82.3%, respectively, after a 30-min incubation in the liver cytosol. Q10 solubilized with HCO-60 was thus reduced only slightly in vivo or in vitro. The critical micelle concentrations of HCO-60 in the absence and presence of Q10 were 0.02 and 0.002% (w/v), respectively. The concentrations of HCO-60 micelles containing Q10 were estimated to be 0.0048% (w/v) in the incubation mixture with cytosol and 0.0041% (w/v) in blood circulation. These results suggest that HCO-60 micelles containing Q10 would remain more stable not only in blood circulation but also in tissues as compared with ethanol-water emulsion. A possible mode of solubilization of Q10 is discussed.

Animals↗

[Primary malignant melanoma of the female urethra: a case report].

A 76-year-old woman visited us with the chief complaint of a urethral mass on September 11, 1984. There was a thumb-sized, brownish and painless mass in the posterior wall of the urethra. Although excretory urogram revealed nothing remarkable, CT scan suggested metastasis of retroperitoneal lymph nodes. Biopsy of the urethral mass revealed malignant melanoma. She was treated with combined chemotherapy of dimethyltriazenoimidazole carboxamide, peplomycin, and cis-diamine-dichloride platinum, but died of respiratory insufficiency on January 6, 1985. Thirteen cases of primary malignant melanoma of the female urethra, including our own, have been reported in the Japanese literature.

Aged↗

[Serial measurements of serum carcinoembryonic antigen (CEA) and neuron-specific enolase (NSE) during chemotherapy of patients with inoperable lung cancer].

Serial measurements of serum CEA levels were analyzed in 226 patients with inoperable lung cancer (115 small cell carcinomas, 64 adenocarcinomas, 37 squamous cell carcinomas and 10 large cell carcinomas) during chemotherapy. Of all patients, 29.1% had pretreatment CEA levels greater than or equal to 5 ng/ml. In all of the patients with complete response, and 15 (68.2%) of 22 patients with partial response whose pretreatment CEA levels were 5 ng/ml or higher, CEA levels fell to below 5 ng/ml. All of 17 patients who showed a decrease greater than 50% in serum CEA levels during chemotherapy showed a shrinkage of more than 50% in the tumor burden. Serial serum CEA level measurements were useful as an indicator of response to chemotherapy in advanced lung cancer. Serial serum NSE levels were measured in 36 patients with small cell lung cancer. Pretreatment NSE levels were elevated to more than 10 ng/ml in 83.1% of all patients. A transient rise in serum NSE levels occurred in 22 out of 33 patients measured on the third day during initial chemotherapy. Serum NSE levels greater than or equal to 10 ng/ml declined to within the normal range in all patients responding to the chemotherapy. The survival in patients whose NSE levels (greater than or equal to 10 ng/ml) fell to within the normal range for more than four weeks was longer than that in other patients. Serial measurements of serum NSE levels were thus useful for monitoring the response to chemotherapy in cases of small cell lung cancer.

Adenocarcinoma↗