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Biomedical subjects

T Nagayama

Publications and source records attributed to T Nagayama.

At least 91 records · Page 5Linked to original sources
PubMed1997

Convergent chemical and electrical synaptic inputs from proprioceptive afferents onto an identified intersegmental interneuron in the crayfish.

Synaptic transmission between proprioceptive afferents from a chordotonal organ in the tailfan of the crayfish and an identified ascending interneuron, interneuron A, in the terminal abdominal ganglion was analyzed. Interneuron A is part of a disynaptic pathway from primary afferent neurons to the lateral giant interneuron involved in producing the characteristic ballistic escape behavior of crayfish. Interneuron A received short and long latency excitatory postsynaptic potentials (EPSPs) from chordotonal afferents. Short latency EPSPs occurred with little central synaptic delay, were unchanged by hyperpolarizing current injection of -2 nA, and remained at a constant amplitude when the nervous system was bathed in saline with a low calcium concentration or saline containing the nicotinic antagonist curare. These EPSPs are thus thought to be mediated by electrical transmission. Longer latency potentials were increased in amplitude by hyperpolarizing current injection, reduced in amplitude when the nervous system was bathed in low-calcium saline, and also reduced by bath application of saline containing curare. These potentials are thus thought to be mediated by chemical transmission. The functional significance of the dual modes of transmission at a key synapse in the escape circuitry is discussed.

Afferent Pathways↗
PubMed1997

[Histopathological effect of neoadjuvant chemohormonal therapy for prostatic cancer].

To improve the therapeutic results in prostatic cancer, radical prostatectomy or total cystoprostatectomy were performed with chemohormonal therapy before operation. Radical prostatectomies were conducted in eight patients with localized prostatic cancer and total cystoprostatectomies in ten patients with severe cystic infiltration. The administration schedule of chemohormonal therapy was as follows: prior to operation, 30-60 mg/sqm/day of etoposide was administered for 7 days every 3 weeks, 250-500 mg/day of diethylbestrol diphosphate for 30 days, and 3.6 mg of LH-RH agonist was also administered. Sixteen of the subjects survived, and were socially rehabilitated (14 cases of NED, 1 case of NC and 1 case of PD) and 2 of the subjects died of cancer. Histopathological findings showed 9 cases of poorly differentiated adenocarcinoma, 4 cases of well differentiated adenocarcinoma and 5 cases of moderately differentiated adenocarcinoma. Histopathological effect of neoadjuvant chemohormonal therapy in surgical specimen showed that 2 of the subjects had grade 0a effect, grade 0b in 7 cases, grade 1 in 5 cases and grade 2 in 4 cases.

Adenocarcinoma↗
PubMed1997

[An autopsy case of severe tuberculosis associated with anal fistula and intestinal perforation].

A 55 year-old man was admitted to the department of the gastroenterology of the hospital because of severe weakness and appetite loss for the past one month. In the last two months, he has been suffering from recurrent fistula of the anus. He left his symptoms without therapy. A gastric ulcer was found out with gastric endoscopy. At the same time, chest X-ray film showed bilateral abnormal shadows, which were suspected of severe pulmonary tuberculosis by a chest physician. After the admission, the patient immediately developed respiratory failure. Both sputa and discharge from anal fistula were positive for acid fast bacillus. Despite of anti-tuberculosis therapy and mechanical ventilation, he died of respiratory failure. At the autopsy, severe pulmonary tuberculosis, tuberculous fistula of the anus, intestinal tuberculosis with perforation, miliary tuberculosis and peptic ulcer of the stomach were defined. We suspected that the extensive disease caused by hematogeneous spread and the late diagnosis of tuberculosis was owing to patient's delay.

Fatal Outcome↗
PubMed1997

[Bufferin-induced lung injury manifesting as acute eosinophilic pneumonia].

A 26-year-old woman was admitted to our hospital because of dyspnea and fever one day after taking medicines for the common cold. A chest roentgenogram and a computed tomogram revealed diffuse patchy infiltrates in both lung fields. Examination of a specimen obtained by transbronchial lung biopsy showed thickening of alveolar walls and infiltration of eosinophils. Bronchoalveolar lavage fluid had many eosinophils. DLST was positive for Bufferin, which the patient took one day before the dyspnea and fever began. We believe that this patient's pulmonary disease was caused by Bufferin. We should realize that this widely used analgesic can cause acute eosinophilic lung disease. The patient was not given corticosteroids, and her condition improved soon after she stopped taking Bufferin.

Adult↗
PubMed1997

[A case of humidifier lung characterized by histopathologic feature].

A 61-year-old man was discharged from our hospital after recovering from bilateral fractures in the neck of each femur. However, a productive cough, dyspnea, and a high grade fever occurred eight hours after returning home. He was thus admitted once more. At rehospitalization, there was radiographic evidence of bilateral infiltrates and hypoxemia. Hypersensitivity pneumonitis was strongly suggested by radiographic evidence, by the fact that no new drugs had been administered, and by a positive result after an environmental provocation test. A diagnosis of humidifier lung was confirmed by a positive precipitins test for humidifier water. Several microorganisms were isolated from humidifier water, and precipitins tests for the isolated microorganisms were mostly positive. Microscopic examination revealed focal alveolitis, bronchiolitis, and perivasculitis. Perivascular leucocytic infiltrations around venules suggested that inhaled antigens might have also caused humidifier lung via a vascular route. Humidifier lung may be due in part to soluble factors, such as endotoxin, present in humidifier water.

Alveolitis, Extrinsic Allergic↗
PubMed1997

[The new criteria for skin prick test of atopic early infants--diagnosis for hypersensitivity of egg white].

To investigate the new criteria for skin prick test (SPT) of seventy-four atopic infants (2-5 months of age at the first visit, Mean 3.8 months, M:F = 54:20) to diagnose for hypersensitivity to egg white. It was classified into three groups by reaction type of SPT in the first visit. Group A were the infants who seemed only late (6 hours) or delayed (48 hours) reaction (n = 26). Group B were seemed immediate (15 minutes) and late or delayed reactions (n = 26), Group C were seemed only immediate reaction (n = 23). Atopic infants and controlled infants without no symptom but have any atopic disease a relative in the third degree, agreed to undergo SPT in the first visit, the prior were undergo 9-12 months of age, too. Serum total IgE (RIST), serum specific IgE antibody of egg white (EWRAST) and peripheral eosinophil counts in the blood (Eo. counts) were determined at the same time of SPT in atopic infants. The best criterion for SPT was the longest diameter of a erythema were greater than 3 mm at late and/or delayed reaction (Sensitivity: 100%, Specificity: 60%) in group A. Two third of infants in group. A were seemed immediate reaction and EWRAST levels were increased to larger than gread two at 9-12 months (p < 0.001). RIST levels and Eo. counts at the first visit were increased compared with the normal levels in the all groups, the prior and EWRAST levels in group B were higher than group A or C (p < 0.05, p < 0.05). RIST and EWRAST levels in group A at 9-12 months were higher than the first visit (p < 0.05, p < 0.01). In conclusion, SPT in atopic early infants were seemed several reactions at the first visit, but all reactions were useful for diagnose for hypersensitivity to egg white.

Dermatitis, Atopic↗
PubMed1997

[Sero-negative tsutsugamushi disease (scrub typhus) diagnosed by polymerase chain reaction].

We report a case of sero-negative tsutsugamushi disease diagnosed by polymerase chain reaction (PCR). A 54-year-old man who worked in Nagano prefecture presented with flu-like symptoms that did not respond to cephalosporin therapy. On admission to another hospital, chest roentgenography revealed abnormal shadows; liver dysfunction was also present. Despite therapy, the patient's condition gradually worsened and he was transferred to our intensive care unit. Erythema on all extremities and scabs on the right medial femoral region and the dorsum of the left foot suggested a diagnosis of tsutsugamushi disease. We administered minocycline and gave percutaneous cardiopulmonary support for adult respiratory distress syndrome. Despite all efforts, the patient died. Although serologic tests were not positive, Karp strains of R. tsutsugamuschi were identified on PCR amplification. Autopsy revealed evidence of acute hemorrhagic pancreatitis, which has not been reported previously in tsutsugamushi disease. We conclude that PCR techniques may be useful in confirming a diagnosis of early tsutsugamushi disease.

DNA, Bacterial↗
PubMed1996

MRI in the mild type of mucopolysaccharidosis II (Hunter's syndrome).

We report imaging findings in a 3-year-old boy with the typical mild type of Hunter's disease. MRI revealed multifocal large cyst- or spindle-like areas of increased and decreased signal in the white matter, including the corpus callosum on T1- and T2-weighted images. The white matter showed high signal on T2-weighted images, isointense with cerebrospinal fluid on all other pulse sequences. To our knowledge, these appearances have not been reported in this disorder. Deposition of mucopolysaccharide and/or glycolipid and increase in fluid content seem to be responsible.

Brain↗
PubMed1996

Glucagon facilitates adrenal catecholamine release mediated by nicotinic receptors but not by muscarinic receptors in anesthetized dogs.

We examined the effects of glucagon on the release of adrenal catecholamines (CAs) in response to splanchnic nerve stimulation (SNS), acetylcholine (ACh), the nicotinic receptor stimulant 1,1-dimethyl-4-phenyl-piperazinium iodide (DMPP), and muscarine in anesthetized dogs. Glucagon and the cholinergic drugs were infused and injected, respectively, into the adrenal gland through the phrenicoabdominal artery. SNS (1 and 3 Hz) or injections of ACh (1.5 and 3 micrograms), DMPP (1 and 2 micrograms), and muscarine (1 and 2 micrograms) produced a frequency- or dose-dependent increase in both epinephrine (EPI) and norepinephrine (NE) output, determined from adrenal venous blood. Glucagon infusion (0.1, 0.3, and 1 microgram/min) enhanced the SNS-, ACh-, and DMPP-induced increases in EPI and NE output in a dose-dependent manner but did not affect the muscarine-induced increases in CA output. The increase in basal CA output induced by the highest dose of glucagon was only slight. Glucagon increased cyclic AMP overflow determined from adrenal venous blood. Our results indicate that glucagon has a facilitatory action on adrenal CA release mediated by nicotinic receptors but not by muscarinic receptors in dogs and suggest that an increase in cyclic AMP production in adrenal medullary cells may be responsible for its selective action.

Acetylcholine↗
PubMed1996

Presynaptic inhibition of exteroceptive afferents by proprioceptive afferents in the terminal abdominal ganglion of the crayfish.

1. Exteroceptive hairs that are sensitive to water displacement and touch are distributed over the surface of the tailfan of crayfish. We show that the sensory neurons innervating these hairs receive a primary afferent depolarization (PAD) from sensory neurons innervating a proprioceptor that monitors movements of the endopodite and protopodite of the tailfan. This PAD occurs only during high-velocity movements of the exopodite, which are similar to those that occur during swimming. The effects that the proprioceptor mediate are widespread, so that afferents in four sensory nerve roots of the terminal abdominal ganglion, innervating hairs on the protopodite, exopodite, endopodite, and telson, receive a PAD. The PAD is unlikely to be mediated through monosynaptic pathways because there is no anatomic overlap between the central projections of chordotonal afferents and many of the exteroceptive afferents. The depolarization is associated with a conductance increase and can be increased by the injection of hyperpolarizing current or reversed (approximately 10 mV above resting potential) by injection of depolarizing current. The properties of the presynaptic input are, therefore, consistent with being mediated through chemical synapses. This is supported by the observation in the electron microscope that the exteroceptive afferents receive chemical input synapses. The depolarization is mimicked by gamma-aminobutyric acid and reduced by bath application of picrotoxin or bicuculline, suggesting that it is a depolarizing inhibitory postsynaptic potential. The PAD reduces the amplitude of exteroceptive afferent spikes, an action that is thus likely to reduce transmitter release and the efficacy of synaptic transmission.

Action Potentials↗
PubMed1996

Foreign workers recruiting policies in Japan.

"This article presents the basic characteristics of the foreign workers recruiting policy in Japan, which consists [of] barring entry to unskilled workers, and confronts it with the actual tolerance for a large number of illegal unskilled workers. After a historical overview of the reasons for the current policy, the article examines elements which reveal that a seclusionist policy is based on mistaken assumptions and reviews policy options to deal with the issue of illegal migration."

Asia↗
PubMed1996

GABA-like immunoreactivity of an identified nonspiking local interneurone in the crayfish terminal abdominal ganglion

Using an antiserum directed against -aminobutyric acid (GABA) to label neurones with GABA-like immunoreactivity, approximately 70 central neurones (68&plusmn;9; mean &plusmn; s.e.m., N=9) were labelled in the terminal abdominal ganglion of the crayfish Procambarus clarkii. This mean number of neurones with GABA-like immunoreactivity represents approximately 10 % of the total number of neurones in the terminal ganglion. A combination of intracellular staining using Lucifer Yellow and immunocytochemical staining revealed that an identified nonspiking local interneurone (the local directionally selective interneurone, LDS) showed GABA-like immunoreactivity.

Journal Article↗
PubMed1996

Localized fibrous mesothelioma with bronchogenic carcinoma.

We report a case of localized fibrous mesothelioma (LFM) of the pleura with bronchogenic carcinoma. LFM arose in the visceral pleura of the upper lobe in the left lung, and lung adenocarcinoma was located in the ipsilateral lower lobe. LFM is a rare mesenchymal tumor of the pleura. Concomitant occurrence with bronchogenic carcinoma has not been previously reported in the English literature.

Biopsy, Needle↗
PubMed1996

[Measurement of the common carotid arterial flow during parabolic flight in the anesthetized rat].

To measure the blood flow of a common carotid artery (CCA) during parabolic flight in the rat, we developed an animal double hold box (ADHB) made of styrene expanded form for the anesthetized rat to keep the animal at a proper posture in an aircaft. Twelve anesthetized rats weighing 291-342 g were surgically operated to mount a ultrasound flowmeter probe (1 mm size,1RS:Transonic Systems Inc.) around the right CCA and to insert a catheter into the right axillar artery for blood pressure measurement. These animals were held comfortably in ADHBs which were placed on the rack installed in the aircraft (MU-300). A total of 27 parabolic flights was performed and the blood flow was measured accurately in 9 rats. This special animal holding facility is useful for various types of animal experiments in an aircraft.

Animals↗
PubMed1996

[A case of thoracic meningioma presenting paraplegia at 4.5 years after removal of a falx meningioma].

A case of a thoracic meningioma presenting paraplegia 4.5 years after removal of a falx meningioma is reported. A 73-year-old woman, complaining of diplopia, was admitted to our department. Neurological examination revealed right abducens palsy. CT demonstrated a well-enhanced right frontal mass beneath the falx. The mass was totally removed under right frontal craniotomy. Its histology was transitional meningioma with rich fibroblasts. 4.5 years after craniotomy, she complained of progressing gait disturbance and nocturnal leg pain. Neurological examination revealed paraplegia, complete loss of leg sensation, loss of patellar and ankle reflex, bilateral positive Babinski reflex and urinary disturbance. Rectal function and anal reflex were preserved. Thoracic MRI demonstrated an intradural extramedullary mass which was well enhanced with Gd-DTPA at Th6-7. Under laminectomy, the mass was totally removed. Its histology was transitional meningioma with rich psammoma bodies and whirl formations. 4 months after removal, her palsy and sensory loss were almost completely recovered. We were able to find 15 cases of combined intracranial and spinal meningiomas in the literature. A young woman of neurofibromatosis suffered from tentorial, intraventricular and C1-2 meningiomas. Of 15 cases without neurofibromatosis including our case, 4 cases were of young boys and 11 cases were of women. Their initial symptoms originated from intracranial meningiomas in 8 cases. Multiple intracranial meningiomas were revealed in only 4 cases. In 9 cases, one case presented a combination of one intracranial meningioma and one spinal meningioma. Histology of intracranial meningioma was almost the same that of spinal meningioma in almost half of the 10 cases. These findings suggest the multi sentricity theory of multiple meningiomas originating in other neuroaxial compartments. Severe spinal dysfunction was recovered after removal in our case. Rectal function and anal reflex were preserved. These anorectal findings suggest that spinal dysfunction is either complete or incomplete. Motor evoked potentials are hopeful tools which can select reversible spinal motor dysfunctions.

Aged↗
PubMed1996

[Interstitial pneumonia associated with mixed connective tissue disease--marked improvement with azathioprine].

A 55-year-old man who complained dyspnea on exertion was given a diagnosis of interstitial pneumonia associated with mixed connective tissue disease, based on symptoms and on physical and laboratory findings. Soon afterward, he experienced an acute exacerbation of the interstitial pneumonia. He was given three courses of steroid pulse therapy and cyclophosphamide, but his condition worsened. After administration of azathioprine in addition to corticosteroids, his respiratory status improved. The dose of corticosteroids was tapered and the patient has been free of disease for two years. Pulmonary involvement in mixed connective tissue disease has been considered to be relatively benign and easily treated with corticosteroids. Recently, however, many cases of corticosteroid-resistant disease with poor outcome have been reported. Azathioprine was very effective against the interstitial pneumonia in this case, but general conclusions about the most effective type of immunosuppressive agent and the timing of its administration must await the results of further study.

Azathioprine↗
PubMed1996

[A comparison of two delivery methods on the bronchodilator effects of beta 2-stimulant].

The airway response to a bronchodilator, salbutamol delivered by a new handy ultrasonic nebulizer and the compressed air nebulizer was studied in a blind manner. Patients by the ultrasonic nebulizer had better percent increase in FVC and FEV1 significantly and in other parameters showed a tendency to being better than those by the compressed air nebulizer. These results suggest that this ultrasonic nebulizer may be more useful than the compressed air nebulizer as inhalation therapy for bronchial asthma. This ultrasonic nebulizer has several advantages over the compressed air nebulizer. This nebulizer is compact size, light weight and has dry batteries as power source, making it more convenient for travel and use at workplace.

Administration, Inhalation↗