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Biomedical subjects

N Hori

Publications and source records attributed to N Hori.

At least 109 records · Page 6Linked to original sources
PubMed1990

[A case report of extragonadal germ cell tumor with retroperitoneal origin].

A case of extragonadal germ cell tumor is reported. A 41-year-old man, an elementary school teacher, was referred to our department with left abdominal pain and gynecomastia on September, 1985. Laboratory examinations revealed markedly high levels of LDH, AFP and HCG-beta. IVP and abdominal CT disclosed dislocation of the left kidney and the large left retroperitoneal mass. The mass was supplied by the left lumbal arteries on the aortogram. Chest X-ray film showed multiple coin lesions in the bilateral lung fields. By percutaneous needle biopsy, the histological finding of the tumor showed choriocarcinoma. No abnormal findings were found in either testicle by the physical and ultrasonic examinations. This case was diagnosed as extragonadal choriocarcinoma with lung metastasis. After 3 courses of chemotherapy (PVB regimen), resection of the retroperitoneal residual mass and lymphadenectomy were performed. Postoperatively, the chemotherapy, CISCA II - VB IV regimen, was repeated. The patient was discharged after 7 months hospitalization. Now, 35 months after operation, tumor markers, chest X-ray and abdominal CT showed no evidence of recurrence of the tumor.

Adult↗
PubMed1989

Effect of anticholinergic drug on long-term potentiation in rat hippocampal slices.

Long-term potentiation (LTP) was studied in CA1 neurons by tetanization of the Schaffer-commissural pathway in rat hippocampal slices. A brief tetanus (200 Hz for 1 s) caused an increase in amplitude of the population spike recorded from the CA1 area (typically about 200% of control), which lasted for more than 2 h. LTP was suppressed by perfusion of the muscarinic antagonist scopolamine (10(-5) M) from 5 min before to 15 min after the tetanus. If perfusion of the drug was begun after the tetanus, there was no affect on LTP. Scopolamine perfused without tetanus did not change the amplitude of the population spike. These results suggest that cholinergic system may affect the generation mechanisms of LTP.

Action Potentials↗
PubMed1989

Electrophysiological estimation of the actions of acetylcholinesterase inhibitors on acetylcholine receptor and cholinesterase in physically isolated Aplysia neurones.

1. The actions of representative cholinesterase inhibitors on the acetylcholine responses of physically isolated single neurones from the pedal ganglion of Aplysia californica were studied, using electrophysiological techniques and rapid agonist application to analyse both the inhibitory actions on the acetylcholine receptor-channel complex and the degree of inhibition of acetylcholinesterase activity on the same neurone. The inhibitors used were physostigmine, edrophonium and diisopropylfluorophosphate (DFP). 2. When selected neurones were suddenly exposed to 50 microM acetylcholine by a 'concentration clamp' technique a large Na-dependent inward current was initiated, and decayed in the continued presence of acetylcholine without external perfusion. However, if perfusion of the acetylcholine solution was reinitiated the current increased somewhat, indicating that the decay of current was due to some combination of receptor desensitization and local depletion of acetylcholine at the membrane by acetylcholinesterase. 3. With simultaneous application of acetylcholine (50 microM) and physostigmine (0.1 to 100 microM) there was a dose-dependent reduction of peak amplitude of the acetylcholine response. However, physostigmine at low concentrations (0.1 to 10 microM) caused a time-dependent increase in the current amplitude alone with a time- and dose-dependent inhibition of acetylcholinesterase activity. At the highest concentration of physostigmine (100 microM) acetylcholinesterase activity was abolished but the current peak was very depressed. After removal of physostigmine from the bathing solution, the current amplitude decreased toward the control at the two lower concentrations as the inhibitory actions on acetylcholinesterase activity were almost reversible, while at the two higher concentrations (10 and 100 microM) the current increased and the inhibition of acethylcholinesterase remained. 4. When acetylcholine (50 microM) and edrophonium (0.1 to 10 microM) were applied simultaneously, edrophonium caused a dose-dependent increase in the peak amplitude that was correlated with a dose-dependent inhibition of acetylcholinesterase activity. Prolonged exposure to edrophonium did not change the peak amplitude and there was no time-dependent change in the inhibition of acetylcholinesterase activity. At the highest concentration of edrophonium used (100 microM), simultaneous application with acetylcholine augmented the peak amplitude relative to control, but to a lesser extent than 10 microM. Prolonged exposure to the highest concentration of edrophonium caused a time-dependent reduction in the peak amplitude. The effects of edrophonium were quickly reversible after the removal of the drug from the bathing solution. 5. DFP (1 and 10mM), similar to 1OO microM physostigmine, caused a dramatic reduction of the peak current on simultaneous application with ftetylcholine. During exposure to DFP the current amplitude and acetylcholinesterase activity were very depressed. After removing DFP from the bathing solution the current amplitude increased to more than the control level after 1 mm DFP, while it did not recover to the control level after 10mM DFP. The inhibition of acetylcholinesterase activity remained at both concentrations. 6. These results indicate that all three cholinesterase inhibitors have dose-dependent actions both at the acetylcholine receptor-channel complex and at acetylcholinesterase. The methods we have developed may be useful in the evaluation of various cholinesterase inhibitors.

Animals↗
PubMed1989

Enhancing effect of glyceryl-1-monooctanoate on the rectal absorption of gentamicin from hollow-type suppositories in rabbits.

A hollow-type suppository containing gentamicin (GM) in its cavity was prepared using Witepsol H-15 (H-15) mixed with glyceryl-1-monooctanoate (MO) or MO alone in the body of the suppository (type I) and a suppository (type II) containing GM and MO in the cavity was constructed using H-15 in the body of the suppository. Without MO, GM (60 mg) was not absorbed (plasma GM levels less than 1 microgram/ml). However, the absorption of GM from the rectum of rabbits was enhanced by coadministered MO in types I and II. Even when the amount of GM was decreased to 6 mg (1/10), GM was observed in the plasma (Cmax, 3.5 +/- 0.3 micrograms/ml) after administration of the suppository made from MO mixed with H-15. The enhancing effect of MO on the rectal absorption of GM could not be further increased by incorporating an amount of MO larger than approximately 300 mg into the suppository. This study demonstrates that MO can be used in the two types of hollow suppositories as an effective enhancing agent of rectal absorption of poorly absorbed drugs such as GM.

Animals↗
PubMed1989

[Clinical application of Sonolith 2000 type B on extracorporeal shock wave lithotripsy for upper urinary tract calculi].

This report describes the results of clinical trials of the second generation extracorporeal shock wave lithotriptor (Sonolith 2000 Type B) in patients with upper urinary tract stones. The studies were carried out on 101 cases at the Departments of Urology, Juntendo University School of Medicine, Kanto Teishin Hospital and General Daiyukai Hospital from Nov. 1987 to Jun. 1988. The location of stones were renal calyx and pelvis in 84 cases, ureteropelvic junction in 7 cases and upper ureter in 12 cases (2 of them had multiple stones at different levels). The average number of treatment per a patient was 1.25, and that of shock waves delivered per treatment was 1798. Ultrasound localization has been effective in all cases. The rate of destruction of the stones was 100% in the kidney, 66.7% in the upper ureter, with an overall average of 95.0%. On the X-ray film obtained six weeks after ESWL treatment, the stone free rate was 53.5%, and the effectiveness rate was 89.1%, including the cases of stone free and cases with fragments smaller than 5 mm. No serious adverse effect was observed, although there were mild transient hematuria in all cases and pyrexia (more than 38.0 degrees C) in 7 cases (6.9%). The procedure was performed safely in the majority of patients without anesthesia. In 10 cases, we applied anesthesia (epidural anesthesia in 3 cases, and local anesthesia in 7 cases) for the prevention of pain. It is concluded that ESWL treatment using Sonolith 2000 Type B is as effective as other types of shock wave lithotriptor previously applied to urolithiasis without serious clinical complication.

Adult↗
PubMed1988

Characterization of an inward current elicited by edrophonium in physically isolated and internally perfused Aplysia neurons.

We have studied the ionic and pharmacological properties of an inward current elicited by edrophonium, a cholinesterase inhibitor, on physically isolated and internally perfused Aplysia neurons using the voltage clamp, internal perfusion and rapid external perfusion techniques. The current amplitude was dependent on the external Na concentration [(Na)o] in an almost linear manner. However, complete replacement of (Na)o with Tris or sucrose failed to abolish the current. Internal application of Na [increased (Na)i] reduced the current amplitude. In normal (Na)o, changing (Ca)o (both increases and decreases in (Ca)o) reduced the current amplitude. In the sucrose-substituted (Na)o-free condition, edrophonium still could cause a small current (less than 5% of the control). However, an increased (Ca)o did not augment this residual current. Cs and Li carried the edrophonium-activated current when substituted for (Na)o. With sucrose-substituted Na-free sea water outside, edrophonium elicited an outward current when the neuron was internally perfused with Cs, but not when the neuron was internally perfused with K. Therefore, it is unlikely that K is permeant. External application of tetrodotoxin, a blocker of voltage-dependent Na channels, external application of Cd and internal application of F did not affect the current. The edrophonium response was most sensitive to strychnine, which was about 10 times more potent than D-tubocurarine. Hexamethonium, however, had no effect. The local anesthetics, lidocaine and procaine, inhibited the response over the same concentration range as D-tubocurarine. We conclude that edrophonium opens a monocationic channel (presumably a type of Na channel) which is sensitive to (Ca)o.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1988

N-methyl-D-aspartate (NMDA) receptors are inactivated by trypsin.

Acute isolation of hippocampal CA3 pyramidal cells using trypsin produces neurons which respond to kainate and quisqualate but not N-methyl-D-aspartate (NMDA). Incubation of 6- to 12-day-old cultured hippocampal neurons or slices of pyriform cortex with trypsin irreversibly removes the NMDA responses normally present without significant effect on responses to kainate or quisqualate. These data indicate that the NMDA receptor has a trypsin-sensitive component which is necessary for agonist recognition or ion channel activation.

Action Potentials↗
PubMed1988

Excitatory amino acid receptors in piriform cortex do not show receptor desensitization.

We have investigated the proposed role of transmitter receptor desensitization as an explanation for the excitotoxicity rank order of several excitatory amino acid agonists as compared to kainic acid, using a brain slice of rat piriform cortex. Responses to glutamate, aspartate, quisqualate, n-methyl aspartate and kainate showed no evidence of receptor desensitization when studied with very long and large ionophoretic pulses, repeated ionophoretic pulses or by bath perfusion. At least in rat piriform cortex, the suggestion that kainate receptors do not desensitize while those to glutamate and quisqualate do, does not apply to nor explain the more potent kainate excitotoxicity.

Animals↗
PubMed1988

Blockade of N-methyl-D-aspartate response in enzyme-treated rat hippocampal neurons.

The responses to excitatory and inhibitory amino acids have been investigated in isolated pyramidal cells from young and adult rat hippocampus using internal perfusion and 'concentration-clamp' techniques. The neurons dissociated in a purely mechanical way were sensitive to all excitatory amino acids (glutamate, kainate, quisqualate and N-methyl-D-aspartate (NMDA] and inhibitory amino acids (glycine, taurine and gamma-aminobutyric acid). The NMDA response was dramatically potentiated by adding glycine at threshold concentration (10(-6) M). The enzyme treatment of hippocampal slices selectively removed the NMDA sensitivity but did not alter all other pharmacological properties of voltage- and agonist-gated ion channels.

Animals↗
PubMed1988

Piriform cortex brain slices: techniques for isolation of synaptic inputs.

Methods are described for preparation of 3 different slices of piriform cortex which allow convenient study of pyramidal neurons and segregation of synaptic inputs. In slices cut parallel to the pyramidal neurons (perpendicular to the brain surface) one can study chemosensitivity of the various parts of the dendritic tree and the soma. By selected division of this slice the population postsynaptic response to activation of the lateral olfactory tract can be studied without action potential generation. Alternatively the superficial lateral olfactory tract can be removed. Stimulation of deeper regions of the slice under these circumstances elicits a pharmacologically different excitation which appears to be that of association fibers.

Aminobutyrates↗
PubMed1988

A male subject with 3 Y chromosomes (48, XYYY): a case report.

We describe a male subject with 3 Y chromosomes who presented with complaints of lack of sexual desire and failure to achieve rigid erection. The patient was tall and had markedly incurved little fingers on both hands as well as small testes. Karyotype was 48, XYYY. The patient's parents had normal karyotypes. Endocrinological profile suggested a primary functional disturbance of the gonads. Testicular biopsy demonstrated atrophic seminiferous tubules without spermatogenesis. To our knowledge this case represents the third instance of a man with an 48, XYYY karyotype without mosaicism.

Adult↗
PubMed1988

Werner's syndrome associated with malignancies: five case reports with a survey of case histories in Japan.

We present 5 cases of Werner's syndrome associated with malignancies and a survey of 26 cases in the Japanese literature. Though tumors of mesenchymal origin have been reported in Werner's syndrome, 14 of the 31 cases cited in this paper developed carcinomas. Carcinoma of the thyroid gland was relatively high in frequency. The significance of carcinomas in Werner's syndrome should be further investigated.

Adenocarcinoma↗
PubMed1988

[A case of testicular feminization].

A 21-year-old female visited the gynecological clinic because of primary amenorrhea. The patient was a phenotypic female with scanty pubic hair, short and blind-ending vagina and bilateral inguinal soft masses. The patients was referred to our clinic. The serum luteinizing hormone level was 27.1 mIU/ml, follicle stimulating hormone level was 8.8 mIU/ml, and testosterone level was 11 ng/ml. Chromosomal analysis of peripheral lymphocytes revealed the karyotype 46, XY. The pathological specimens of bilateral inguinal masses showed atrophic testis without spermatogenesis and with Sertoli's cell nodular hyperplasia. The diagnosis of testicular feminization was established.

Adult↗
PubMed1988

[Clomiphene citrate therapy in idiopathic male infertility].

Clomiphene citrate therapy was performed on 30 patients with idiopathic male infertility, who were intractable to non-hormonal therapy. Clomiphene citrate was administered orally at a dose of 25 mg per day for 25 days with 5 days of rest following Paulson' protocol, and we favorable results were obtained: Both sperm count and sperm motility improved in 11 cases (36.7%). Odera's score count decreased in 14 cases (46.7%), which were judged as effective. The wives of 4 patients treated by this therapy became pregnant. After this therapy, the serum levels of luteinizing hormone, follicle stimulating hormone, testosterone and prolactin were 1.90, 1.81, 1.89 and 1.22 times higher, respectively. These findings indicate that clomiphene citrate therapy is an effective for idiopathic male infertility, but we need to consider that the sudden and marked elevation of serum testosterone level by this therapy might affect male accessory sex organs such as the prostatic gland which shows androgen dependency later in life.

Clomiphene↗
PubMed1988

[Primary carcinoma of the male urethra: report of two cases].

Two cases of primary carcinoma of male urethra are reported. Case 1: A 31-year-old male, who complained of urethral bleeding, was admitted to our clinic in April, 1982. A rice size papillary tumor was found at the fossa navicularis in the glans, and resected by electric knife. Histologically, the tumor was well differentiated squamous cell carcinoma. Case 2: A 37-year-old man, who complained of urethral bleeding, was admitted to our clinic in July, 1985. A tumor was found at the fossa navicularis in the glans and resected. Histologically, the tumor was well differentiated squamous cell carcinoma confined to mucosa. These two cases have not shown any signs of recurrence. Including these cases, 135 cases of primary carcinoma of urethra in the literature in Japan are reviewed.

Adult↗
PubMed1987

D-600 blocks open Ca2+ channels more profoundly than closed ones.

The open channel blocking action of the Ca2+ antagonists, D-600 and Cd2+, was investigated in single neurons isolated by enzymatic treatment from dorsal root ganglia of frog. Using a 'concentration clamp' (jump) technique Ca2+ antagonists were applied to the preparation just before (less than 100 ms) or during a depolarizing step which induced the maximal peak amplitude of Ca2+ current (ICa). The inhibitory action of D-600 was more pronounced when applied during a depolarizing step than when applied just before a depolarizing step. In contrast, Cd2+ was equally inhibitory, whether applied before or during the depolarization. Thus, D-600 affects open channels more quickly or more profoundly than closed ones, while Cd2+ acts equally on both open and closed Ca2+ channels.

Animals↗
PubMed1987

Responses of pyriform cortex neurons to excitatory amino acids: voltage dependence, conductance changes, and effects of divalent cations.

The actions of ionophoretically applied N-methyl aspartate (NMA), quisqualate, and kainate, thought to activate three different types of excitatory amino acid receptors, were studied on pyramidal neurons of the rat pyriform cortex, maintained in an isolated, submerged, and perfused brain slice. Intracellular recordings were made with either K acetate or CsCl electrodes. In most neurons all three agonists elicited monophasic responses which could be evoked at 20-sec intervals. Some neurons showed biphasic responses, most commonly to kainate but, on occasion, also for quisqualate. The slower component appeared to be correlated with excitotoxicity and, consequently, was difficult to study. As a result the kainate responses studied were from neurons selected for having a single component. In neurons selected for having a linear current-voltage relationship or neurons loaded with Cs to suppress K conductance and linearize the current-voltage relationship, the average changes in resistance recorded during ionophoretic responses at resting potential were as follows: NMA, 131.2 +/- 6.7% of control; kainate, 104.7 +/- 5.8% of control; and quisqualate, 92.8 +/- 2.8% of control. The magnitude and direction of the conductance change were very reproducible in any one neuron, but especially for kainate some cells showed clear conductance increases, while others showed clear conductance decreases. Using CsCl electrodes it was possible to reduce K+ conductance and depolarize the neurons over a wider range. By passing depolarizing current it was possible to reverse the responses. The response to all three agonists reversed at the same depolarized potential. This observation indicates that while there are differences in the ionic channels associated with the three agonists at resting potential, the channels have similar properties at more depolarized potentials. Responses to all three agonists were influenced by the concentrations of divalent cations in the perfusion medium. The NMA responses were most sensitive to Mg, increasing in amplitude in the absence of Mg and being depressed by Mg elevation. All responses were sensitive to Ca, with discharges being greatly increased by low Ca and depressed by high Ca. The kainate response was most sensitive to Ca concentration changes. Unlike reports from other preparations the apparent conductance decreases to NMA were not altered by the perfusion of solutions with either no added Mg or no added Ca. The NMA response was very much reduced in either Co (1-2 mM) or Zn (100-200 microM).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗