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Biomedical subjects

H Kojima

Publications and source records attributed to H Kojima.

At least 505 records · Page 28Linked to original sources
PubMed1990

Laryngeal pacing in unilateral vocal cord paralysis. An experimental study.

In an attempt to remobilize a unilaterally paralyzed vocal cord, experiments were made in five adult dogs. Adduction of the paralyzed vocal cord for phonation in synchrony with the intact cord was achieved by electrical stimulation of the adductor muscles that was triggered by the signals from the cricothyroid muscle. The difference in the level of action potentials of the cricothyroid muscle between during phonation and during respiration was used for setting the threshold so as to differentiate phonation from respiration. Nearly synchronous movement of the two vocal cords thereby attained during phonation greatly improved the voice quality that was hoarse without the paced stimulation.

Action Potentials↗
PubMed1990

Analysis of coat-color patterns in aggregation chimeras between BALB/cA and C3H/HeN mice with special reference to migratory patterns and clone number of epidermal melanoblasts.

Chimeras provide unique opportunities to study interactions between the phenotypically similar but genotypically allogeneic cell populations during embryogenesis in vivo. From the quantitative analysis of coat-color patterns in C3H/HeN----BALB/cA chimeras, a model was proposed stating that the aggregability of the C3H/HeN-derived melanoblasts in the chimeras was inversely related to the ratio between the mean free path of the epidermal melanoblasts in the normal C3H/HeN mouse and that in the chimeras. As a corollary, the possibility was suggested that during the migration of melanoblasts, mechanisms identical with or similar to contact inhibition of movement might operate after collision between the isogeneic, but not between the allogeneic melanoblasts. With regard to the number of melanoblast clones in the trunk region of the mouse, the present series of analyses yielded the value of 24-28 arranged unilaterally; the value closely approximated the number of the somites in that region and provided further support for the proposition made earlier by Tachi [Dev Genet 9: 121-154, 1988; "Development of Preimplantation Embryos and Their Environment." New York: Alan R. Liss, Inc., 1989, pp 263-274].

Animals↗
PubMed1990

Involvement of the cholinergic system in haloperidol-induced release of dopamine from slices of striatum in the rat.

The effects of cholinergic and anticholinergic drugs on spontaneous or haloperidol-induced release of dopamine (DA) were studied in vitro. The slices of striatum were placed in a chamber and continuously superfused with Krebs' solution, containing various concentrations of haloperidol, with or without atropine, d-tubocurarine (d-TC), tetrodotoxin (TTX), physostigmine or carbachol. Haloperidol, enhanced the release of endogenous DA from the slices of striatum at an EC50 value of 25.6 microM. The effect of haloperidol was significantly reduced by atropine (2.5 microM), while it was unaffected by d-TC (10 microM) and TTX (1 microM). In contrast, physostigmine (3.7 microM) significantly increased the haloperidol-induced efflux of DA from the slices of striatum. In addition, acetylcholine (ACh), in the presence of physostigmine or carbachol, enhanced the basal efflux of DA at EC50 values of 2.8 microM and 83 microM, respectively. The effect of ACh on the efflux of DA was antagonized by atropine. These data suggest that haloperidol-induced release of DA is, at least partially, mediated by the activation of muscarinic ACh receptors located in the striatum.

Acetylcholine↗
PubMed1990

Sodium cromoglycate therapy in IgA nephropathy: a preliminary short-term trial.

Sodium cromoglycate (SCG), an antiallergic agent, is an effective drug in an experimental model for IgA nephropathy. The present report concerns a preliminary trial of patients with IgA nephropathy and proteinuria (greater than 1.0 g/d), which was conducted to determine the therapeutic value of SCG. Thirty patients were divided into two groups: one group (n = 15) was given oral SCG (1,200 mg/d) for 16 weeks after an observation of 4 weeks (SCG group), and the other group (n = 15) was observed without the changes of prescription (control group). No fluctuations were noted in proteinuria during the observation period in both groups. Proteinuria in the SCG group slowly decreased throughout the time course; however, a significant reduction was observed at 16 weeks as compared with that of the control group. On the other hand, no significant changes were noted in creatinine clearance (Ccr), serum albumin (s-alb), serum IgA (s-IgA), and IgA-CIC between groups. Five of 15 patients, designated "responders", showed a reduction in proteinuria of more than 50% of the pre-value (average value of observations period). The responder and nonresponder groups were comparable in clinical and histopathological data at the beginning of the trial. Nevertheless, no significant correlations arose concerning any point. Short-term SCG therapy may be beneficial in reducing proteinuria in some patients with IgA nephropathy. Allergic reactions may participate in the pathogenesis of this disease.

Adult↗
PubMed1990

Frequent detection of hepatitis C virus US strain in Japanese hemophiliacs.

Hemophiliacs have been found to be at high risk of hepatitis. Hemophiliacs in Japan receive imported clotting factors as well as domestic ones. Recently we found that hepatitis C virus (HCV) could be classified into at least two types, HCV-US and HCV-J, depending on the nucleotide sequence. We analyzed the nucleotide sequences of virus RNAs from the plasma of patients with hemophilia A or B and found HCV-US in 3 of 4 Japanese hemophiliacs examined.

Adolescent↗
PubMed1990

Detection of tumour necrosis factor/cachectin in pleural effusion of patients with lung cancer.

We have found that the pleural effusion obtained from a patient with lung cancer (adenocarcinoma) has cytotoxic activity against the patient's lung cancer cells. This finding occurred in the course of establishing a lung cancer cell line from the patient's pleural effusion. The cytotoxic factor was partially purified from the pleural effusion and characterized. It had cytotoxicity against L-929 mouse fibroblasts in the standard 18-h killing assay of tumour necrosis factor (TNF). By molecular sieving chromatography, the activity appeared at molecular weight of 50,000. This activity was completely blocked by a monoclonal antibody to TNF. From these results, we conclude that the cytotoxic factor in the pleural effusion is TNF. The concentration of TNF in the pleural effusion was 34.5 pg/ml by radioimmunoassay. In addition, we detected TNF activity and protein in two other cases of carcinomatous pleural effusion. Therefore, it would appear that in vivo TNF displays cytotoxic activity against cancer cells.

Adenocarcinoma↗
PubMed1990

Effects of neutral pepsin on the deposition of dietary antigens in glomeruli from IgA nephropathy.

Recently we reported on the participation of dietary antigens in the pathogenesis of IgA nephropathy. Particularly, the glomerular deposition of dietary antigens (casein, soybean protein, rice protein) was observed in some cases with IgA nephropathy. It is known that human urinary pepsin (HUP) prepared from the urine of a healthy adult acts as an immune complexase at neutral pH. In this study, the effects of incubation with HUP on the glomerular deposition of dietary antigens was investigated by an immunofluorescence technique in 48 patients with IgA nephropathy, four patients with Henoch-Schönlein purpura nephritis and 69 with other glomerulonephritides. In 33 cases (68.8%) soybean protein and in 12 (25.0%) casein was found in biopsies of patients with IgA nephropathy. After a 3-day incubation with HUP there was no change in the deposition of IgA in 12 cases, a decrease in 22 and complete elimination in 14 cases. The deposits of soybean protein increased in 12 cases, did not change in 20, decreased or was abolished in five and was positively converted in 11. Exceptionally, in five patients treated with HUP, the deposition of soybean protein appeared concomitantly with the disappearance of IgA deposits. Such a concomitance did not occur either in other glomerulonephritides or in studies of other dietary antigens. Thus it appears that soybean protein may be deposited in the glomerular mesangium as an antigen in some patients with IgA nephropathy.

Antigens↗
PubMed1990

Stimulus train-induced bursting in hippocampal slices: difference between CA1 and CA2/3 subfields.

We studied the relationship between CA2/3 and CA1 subfields in the generation of stimulus train-induced bursting using in vitro hippocampal slices. Repeated stimulation to the stratum radiatum induced three types of epileptiform activities: afterdischarge bursts, spontaneous bursts and single stimulus-triggered bursts. In the intact slices, spontaneous bursts in CA3 preceded those in CA1, whereas afterdischarge bursts in CA3 followed those in CA1 when it was possible to distinguish differences in the burst onset. After transection between CA2/3 and CA1, neither spontaneous nor triggered bursts could be induced or maintained in isolated CA1, where only small afterdischarge bursts with a higher bursting frequency were observed. It was difficult to induce afterdischarge bursts by the tetani to the mossy fibers. Some of the mechanisms underlying the generation of these stimulus train-induced bursts are discussed.

Animals↗
PubMed1990

Eosinophilic neuronal inclusion bodies in the temporal lobe.

Intracytoplasmic neuronal inclusion bodies were found in the temporal lobe of an elderly woman. The oval or rod-shaped inclusion bodies were eosinophilic, showed bright red staining with azan, and were about half the size of the nucleus of a large neuron. They were non-argyrophilic and non-congophilic. Ultrastructurally, the inclusion bodies consisted of aggregates of filamentous materials showing partial periodicity. Among inclusion bodies reported up to now, the present ones resembled some described previously as "thalamic inclusions", but were different with regard to their partial filament periodicity, and unusual in that they were located in the deep layer of the temporal lobe and not in the thalamic nuclei.

Actins↗
PubMed1990

Protective effect of DM-9384, a novel pyrrolidone derivative, against experimental cerebral anoxia.

The protective effects of DM-9384 [N-(2,6-dimethylphenyl)-2-(2-oxo- 1-pyrrolidinyl) acetamide] against cerebral anoxia were investigated using various animal models. Oral administration of DM-9384 resulted in a significant prolongation of survival time in mice and rats subjected to the normobaric hypoxia; its minimal effective doses were 30 and 10 mg/kg, respectively. A significant protection by this drug against hypobaric hypoxia, histotoxic anoxia and cerebral ischemia also occurred in mice at a dose of 100 mg/kg, p.o. Bifemelane (100-300 mg/kg, p.o.) was protective against these models except for hypobaric hypoxia, and the effects of piracetam, aniracetam and pramiracetam (1000 mg/kg, p.o.) were variable depending on the type of anoxia model used. DM-9384 (100 mg/kg and lower) attenuated the hypolocomotion and the disturbance of cerebral energy metabolism such as a decrease in ATP, an increase in lactate and lactate/pyruvate ratio induced by hypoxia in rats. The spontaneous motor activity, uptake and utilization of brain glucose in normal animals, however, were not influenced by this drug. Based on these results, DM-9384 is characterized as a broad spectrum anti-anoxic drug with negligible CNS depression, and the cerebral protective effect of this drug may be, at least in part, attributable to its ability to improve the cerebral energy metabolic disturbance.

Animals↗
PubMed1990

Development of stable film test for rapid estimation of blood or plasma 3-hydroxybutyrate.

A film test for the rapid detection of plasma/serum 3-hydroxybutyrate (3-OHB) has been developed. The film contains NAD, nitro blue tetrazolium, 3-OHB dehydrogenase, and diaphorase, and the surface is coated with modified biomembrane and can detect 50-1500 microM 3-OHB within 2-3 min. One drop or 50 microliters of plasma/serum or blood is applied to the film, and the violet color is read via reflectance meter after 2 min. Plasma/serum samples greater than 1500 microM 3-OHB can be measured by dilution with saline. In blood with 40% hematocrit, the color developed is 50% less than with plasma/serum, and this was adjusted in the reflectance meter. A good correlation (r = 0.99) was observed between results with automated and film methods and between visual methods and reflectance meter. In insulin-dependent diabetes mellitus, all 3 subjects with positive ketonuria (+ +), 8 of 12 subjects with mild ketonuria (+), and 7 of 25 subjects without ketonuria exhibited elevation of 3-OHB in blood greater than 200 microM. The results indicate that 3-OHB film is valuable not only in the emergency room for the differential diagnosis between ketoacidotic and nonketotic hypersomolar coma but also as a marker for insulin dependency, energy dependency on fatty acid compared with glucose, and metabolic control of diabetes.

3-Hydroxybutyric Acid↗
PubMed1990

[Chronic idiopathic neutropenia improved by recombinant granulocyte colony stimulating factor].

A 55-year-old man was admitted to our hospital for the evaluation of neutropenia. On physical examination, he had apthae and splenomegaly. CBC showed 1,000/microliter WBC with 5% neutrophils, and microcytic anemia consistent with iron deficiency. Bone marrow examination revealed a marked decrease of mature neutrophils, but normal percentage of immature myeloid cells. There was no morphological abnormality in the hemopoietic cells. He had no drug or family history responsible for the neutropenia. Anti-neutrophil auto-antibody was negative. Hence, a diagnosis of chronic idiopathic neutropenia (CIN) was made. He developed frequent episodes of infection such as balanitis, peri-anal infection, gingivitis, and pharyngitis. He was treated with steroid pulse therapy, anabolic hormone, and high dose gamma-globulin infusion, but no significant improvement occurred. Then, recombinant granulocyte-colony stimulating factor (rG-CSF) was started. The neutrophil count was normalized by the 7th day of 5 micrograms/kg/day rG-CSF administration. The administration of G-CSF was discontinued after a 14-day course. Thereafter, the neutrophil count remained at near normal level (approximately 1,500/microliter) and there have been no episodes of infection in the last 5 months. However this cannot be explained simply by the direct effect of rG-CSF on the myeloid precursors; rather, it suggests some unknown effect of G-CSF on the bone marrow microenvironment regulating myeloid hemopoiesis. We consider this to be a rare case of CIN with frequent episodes of infection, which was successfully treated with G-CSF.

Agranulocytosis↗
PubMed1990

[A case of cystic metastatic intracranial amelanotic melanoma--analysis of findings in CT and MRI].

A case of cystic intracranial metastatic amelanotic melanoma is presented. As far as we know, cyst formation in intracranial melanoma is rare, and only 15 cases of intracranial amelanotic melanoma have been reported until now. A 63-year-old man was admitted with headache and progressive visual disturbance. CT scan revealed a large low-density mass with ring-like enhancement in the left frontal lobe. Both T 1-and T 2-weighted MRI images revealed hyperintensity. A left frontotemporal craniotomy was performed. A yellowish mass was observed in the frontal lobe. The content of the cyst consisted of old hematoma, xanthochromic fluid and necrotic tissue, was evacuated and the cyst wall was totally resected. No abnormal pigmentation was noted in the cyst wall and surrounding brain tissue. The histological examination revealed amelanotic melanoma. Primary lesion was found on the left thigh later and resected. The patient died of further intracranial metastasis with repeated hemorrhage 5 months after the admission. Both CT and MRI findings of our case is atypical as an intracranial malignant melanoma. However, these are compatible with those of intracerebral hemorrhage in subacute stage. It is suggested that melanoma may make the diagnosis difficult when tumor hemorrhage modifies the images of CT or MRI.

Brain Neoplasms↗