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Biomedical subjects

K Asakura

Publications and source records attributed to K Asakura.

At least 163 records · Page 9Linked to original sources
PubMed1990

[The study of chemical mediators in the patients with allergic rhinitis. 1). Histamine, leukotriene and kinins in the nasal secretion during early phase response].

For the purpose of studying the roles of chemical mediators during early phase response of allergic rhinitis, the levels of histamine, leukotriene C4 (LTC4) and kinins in the nasal lavage fluid were measured before and after the nasal challenges with antigens. Seventeen patients with perennial allergic rhinitis with positive intradermal skin reactions to mite antigen extracts were included in this study. The nasal samples were obtained both by aspirating and instilling 5 ml of saline into patient's nostrils before and ten minutes after the nasal challenges. After the nasal challenge with control disk, the concentration of histamine in the nasal samples increased, and the concentrations of LTC4 and kinins did not increase significantly. After the nasal challenges with mite or house dust disk, the concentration of histamine increased as much the same as that after the nasal challenges with control disk, and the concentrations of LTC4 and kinins increased significantly compared with those after the nasal challenges with control disk. delta histamine and delta kinins (delta: net increments in the concentrations after the nasal challenge with antigen over values before the nasal challenge) were significantly correlated with delta albumin. The patients with severe nasal symptoms tended to present more remarkable net increments of chemical mediators than the patients with mild and moderate nasal symptoms. Similar tendencies were recognized in the relationships between the severity of nasal symptoms provoked by nasal challenge with antigen and net increments of chemical mediators. We suggest that the amounts of chemical mediators during the allergic reaction denoted the severity of nasal symptoms in allergic rhinitis patients.

Acute-Phase Reaction↗
PubMed1990

[Effects of uvulopalatopharyngoplasty in adult patients with obstructive sleep apnea syndrome].

We performed uvulopalatopharyngoplasty (UPPP) in 51 adult patients with obstructive sleep apnea syndrome (OSAS). After UPPP, there were statistically significant improvements in apnea-hypopnea index (AHI), the lowest value of oxygen saturation during sleep and total time of apnic episodes. 28 patients (54.9%) were good responders who represented more than 50% improvements in their AHI. Poor responders tended to be more severe and older than good responders. After cephalometric analysis, poor responders were revealed to show significantly poor mandibular prognatism and also lower positioned hyoid bone than good responders.

Adult↗
PubMed1990

[Detection of platelet-activating factor in nasal lavage fluid from patients with pollinosis and experimental animals with nasal allergy].

Platelet-activating factor (PAF) is released in vitro by the reaction of antigen and IgE antibody on basophilic cells. In order to clarify that PAF was released in vivo during nasal allergic response, we measured PAF activities in nasal lavage fluids from both 10 patients with pollinosis and ovalbumin (OA)-sensitized guinea pigs before and after topical antigenic challenge. PAF activities were measured by their aggregating ability of washed rabbit platelets. The levels of lyso-PAF were determined after acetylation of lyso-form into the biologically active form of PAF. PAF or Lyso-PAF activities were detected in the nasal lavage fluids soon after the topical antigenic challenge in 7 patients. They were also found during late phase of between 3 and 8 hours after the challenge in 8 patients. In sensitized animals, PAF activities in the nasal lavage fluids significantly increased soon after topical antigenic stimulations. These data suggested that PAF was released during both early and late-phase nasal allergic reactions and might account for pathogenesis of allergic rhinitis.

Animals↗
PubMed1990

[Effect of platelet-activating factor on nasal vascular permeability and eosinophil accumulation in guinea pigs].

Both the increased nasal vascular permeability and eosinophil accumulation were commonly observed in nasal mucosa with allergic rhinitis. Topical administration of platelet-activating factor (PAF) produced dose-dependent increases in nasal vascular permeability concomitant with the increase in both the histamine and leukotriene C4 (LOC4) concentrations of nasal lavage fluid, in non-sensitized guinea pigs. The selective PAF antagonist CV-3988 inhibited these responses. The PAF-induced nasal vascular permeability was also inhibited by a H1 antagonist (diphenhydramine) and a peptido-LTs antagonist (FPL-55712). However, in ovalbumine (OA)-sensitized guinea pigs, CV-3988 did not affect antigen-induced increase in nasal vascular permeability. Four hours after topical administration of antigen or PAF to OA-sensitized guinea pigs, a marked eosinophil infiltration in the nasal mucosa was noted. This antigen-induced eosinophil infiltration was inhibited by CV-3988. These results suggests that PAF plays a major role in the antigen-induced eosinophil accumulation rather than in the antigen-induced vascular permeability.

Animals↗
PubMed1990

[Dilator naris activity in relation to obstructive sleep apnea].

We evaluated the activity of dilator nasalis+ EMG (Electro-Myo-Graphy) and submental EMG during sleep in three patients with obstructive sleep apnea syndrome. Both EMG activities involved periodic changes which proved to be correlated with each other (r = 0.85). Apnea and hypopnea episodes always occurred at the nadir of these periodic changes. The activity of dilator nasalis+ EMG, as well as submental EMG, at the nadir of these periodic changes was significantly lower during REM (Rapid Eye Movement) sleep than non-REM sleep and also significantly lower during severe airway obstruction accompanied by paradoxical movements of thorax and abdomen. The correlation of this EMG activity with SaO2 or the duration of obstructive apnea was more remarkable in submental EMG than dilator nasalis+ EMG in the observed patients.

Adult↗
PubMed1990

[Combination of serial transcranial Doppler examinations and cerebral blood flow studies in the management of cerebral vasospasm after subarachnoid hemorrhage].

In 13 patients who had ruptured intracranial aneurysms, serial transcranial Doppler (TCD) and cerebral blood flow (CBF) examinations were performed in order to evaluate the degree of cerebral vasospasm. All patients showed some extent of vasospasm on angiography, which was performed between Day 7 and 10. The flow velocities of either the middle cerebral arteries or the anterior cerebral arteries, measured by TCD, began to increase on post hemorrhage Day 5, and maximum flow velocities were recorded between Day 9 and 13, with normalization occurring within the following 2 weeks. In 5 cases of symptomatic vasospasm, a rapid increase of flow velocities preceded clinical manifestation of the vasospasm. Maximum flow velocities of the 5 cases were at a higher level in the range of 119-184cm/sec (mean 149cm/sec) that the cases where there were no symptoms. Consequently, serial TCD examinations were very useful for the early detection of vasospasm after subarachnoid hemorrhage. And it was confirmed that the change of flow velocities was more important than the value itself, and that the rapid increase of flow velocities indicated severe ischemia. However, for judging when vessel narrowing was resolving, the usefulness of the TCD examinations were doubtful. This is because flow velocities measured by TCD are thought to be fairly much influenced by multiple factors such as the change of blood pressure, blood volume, which were caused by the active treatment for the vasospasm. Serial measurements of CBF were also made 2-7 times (mean 3.1 times) during the first two weeks following subarachnoid hemorrhage using the 133Xe intravenous injection method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Regional effects of craniotomy on cerebral circulation and metabolism: PET study on the un-ruptured aneurysmal surgery].

Regional effects of craniotomy on cerebral circulation and metabolism, such as regional cerebral blood flow (rCBF), regional cerebral oxygen consumption (rCMRO2), regional oxygen extraction fraction (rOEF), and regional cerebral blood volume (rCBV) were examined by a PET (positron emission tomography) study concerning surgery that was performed on unruptured aneurysm patients. Eight patients with intracranial un-ruptured aneurysms were studied pre- and post-operatively by the 15O labelled-gas steady-state method, using HEADTOME-III. All patients underwent aneurysmal surgery performed by the transsylvian approach. There was a significant increase in the mean OEF values taken from the whole-brains of 8 patients, but there was not a significant change in CBF, CMRO2 or CBV. The increase in OEF was caused by decrease of O2 content, which was caused by post-operative decrease in the Hb value. So, this OEF increase was not the direct effect of craniotomy. In 2 patients, the rCBF and rCMRO2, in the fronto-temporal region (where craniotomy was performed) increased post-operatively. This regional effect suggests transient reactive hyperemia following compressive ischemia during the operative procedure, and metabolic demands for recovery of brain function. In 2 other patients, who had relatively low rCBFs during the pre-operative study, rCBF and rCMRO2 in the bi-frontal region had decreased more at the post-operative study. This change appears to have been caused by removal of cerebrospinal fluid and depression of the frontal lobe. From this study, it becomes evident that the regional effect of craniotomy on cerebral circulation and metabolism is not so great, when adequate microsurgical techniques are used.

Adult↗
PubMed1990

[A case of pure trigeminal motor neuropathy].

We reported a case of pure trigeminal motor neuropathy. A 57-year-old man was admitted with the complaints of vague headache and left upper limb numbness. Neurological examination showed mild wasting of the right masseter muscle on chewing. The jaw deviated to the right when he opened his mouth fully. Corneal reflex was intact bilaterally and so was the sensation on the face and taste. Mild hemiparesis including the face was observed on the left. Laboratory data including cerebrospinal fluid analysis were normal except for mild glucose intolerance. Blink reflex, brainstem auditory response and trigeminal sensory evoked potential elicited by electric stimulation of the lower lip were all normal. EMG findings obtained from the left masseter and lateral pterygoid muscles were neurogenic. The CT scan demonstrated a characteristically distributed low density area, which substituted the muscle supplied by the motor branch of he trigeminal nerve, namely, the right masseter, temporalis, lateral and medial pterygoid muscles. With MRI, the lesion was high on T1 and T2 weighted images. In addition, spotty high signal intensities suggestive of small infarction were observed in the bilateral centrum semiovale on T2 weighted images. Judging from the above results, the present case was believed to have pure motor trigeminal neuropathy confirmed by electrophysiological findings and image analyses together with clinical features. The mild left hemiparesis was thought to be incidental complication of vascular origin.

Cranial Nerve Diseases↗
PubMed1990

[The effects of oral adsorbent (AST-120) in the experimental model of chronic renal failure--pathophysiological study on renal function, glomerular hypertrophy, mesangial function and glomerular histology].

Oral adsorbent (AST-120) reduces blood levels of urea and creatinine in experimental studies. It has also been shown to retard the progression of chronic renal failure in clinical studies. In the present study, the effect of AST-120 was examined in the rat model of subtotal nephrectomy (sNPX). This experimental model of chronic renal failure is characterized by glomerular hyperfunction, glomerular hypertrophy, increased mesangial trapment of macromolecules and subsequent glomerular sclerosis. We report the effect of AST-120 on glomerular hyperfunction, glomerular hypertrophy and mesangial trapment of macromolecules in the early stage and glomerular function and histology in the late stage of the rat model of sNPX. From 2 days after sNPX, rats were fed regular rat chow with (AST group: AST) or without (control) AST-120. At 2 weeks, iron dextran (ID) was injected intravenously. Three days after the injection, mesangial trapment of ID was largely ameliorated in AST when compared with control (p less than 0.02). The value of mean planar area of glomerulus (PAmean) in AST was significantly lower than that in control (p less than 0.05). At 2 and 9 weeks, the values of GFR and RPF in AST were all statistically higher than those in control. At 9 weeks, whereas average glomerular sclerosis index (SI: 0-4 scale) was 1.07 in control, significantly lower SI (0.57) was noted in AST (p less than 0.05). Thus, AST-120 has effects on glomerular hypertrophy, increased mesangial trapment of macromoleculus and finally the progression of chronic renal failure in the rat model of sNPX. The effects are not through reducing glomerular hyperfunction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adsorption↗
PubMed1989

The pathophysiological role of kinin and chemical mediators on experimental allergic rhinitis.

In order to clarify the pathophysiological role of the chemical mediators, the releases of kinins, histamine and leukotriene C4(LTC4) into the nasal cavity were measured following nasal allergic challenge in ovalbumin(OA)-sensitized guinea pigs, or following nasal stimulation with one of these chemical mediators in OA-non-sensitized animals. In sensitized animals, an increased vascular permeability of nasal mucosa was recognized immediately after antigenic stimulation and lasted for 60-90 minutes. Releases of kinins and LTC4 into the nasal lavage fluid augmented not only immediately after the antigenic challenge, but also during 60 to 90 minutes after the stimulation. Release of histamine into the nasal lavage fluid was observed only immediately after the antigenic stimulation. In non-sensitized guinea pigs, nasal stimulation with bradykinin accelerated nasal vascular permeability. Nasal stimulation with histamine or LTC4 resulted in increase of nasal vascular permeability and of kinins concentration in the nasal lavage fluid. These results suggest that kinins might be concerned with the immediate and later vascular permeability during the allergic response.

Animals↗
PubMed1989

Mesangiolytic glomerulonephritis associated with Takatsuki's syndrome: an analysis of five renal biopsy specimens.

Renal biopsy specimens from five patients with Takatsuki's syndrome were studied. Proteinuria and hematuria were modestly positive in four cases and three cases, respectively. One case demonstrated early azotemia, while four cases revealed normal serum creatinine levels. All cases displayed glomerular enlargement and lobulation, mesangial cell proliferation, and double contour structure, simulating membranoproliferative glomerulonephritis. It is noteworthy that mesangial loosening was also detected in the renal biopsy specimens of this study. This change was present diffuse-globally in the well-developed cases and focal-globally or segmentally in the developing cases. In addition, various morphologic expressions were observed, ie, microaneurysms congested with RBCs, tentatively termed mesangial hyaline thrombi, nodule-like lesions, and tiny to small-sized mesangiolytic lesions. Since all these features could be explained by low-grade mesangiolysis, the renal alteration associated with this syndrome was termed mesangiolytic glomerulonephritis. Humoral factor(s) also toxic to the mesangium were implicated.

Adult↗
PubMed1989

Metastatic squamous cell carcinoma of the paranasal sinuses from a primary squamous cell carcinoma of the urinary bladder.

Metastatic tumours of the paranasal sinuses from primary lesions of the urogenital tract are rare, with about 50 cases so far being reported in the literature. The most frequent primary lesions is a renal carcinoma. We have experienced a case of paranasal sinus malignancy. There were no symptoms of urinary tract carcinoma preceding those in the paranasal sinuses. This case was later revealed at autopsy to be a metastasis from a diverticulum of the urinary bladder.

Aged↗
PubMed1989

[Clinical analysis of 24 cases of caudate hemorrhage].

Twenty-four patients with caudate hemorrhage, in whom such definite organic lesions as arteriovenous malformations or ruptured cerebral aneurysms could not be proved, were analyzed. These cases comprise 2.0% of 1202 cases of hypertensive intracerebral hemorrhage diagnosed by computed tomography and experienced from 1976 through 1987. Thirteen patients were male and 11 were female. Their average age was 61 years. Headache (67%) and nausea and vomiting (50%), which were often the initial symptoms, were similar to those of subarachnoid hemorrhage. The main clinical symptoms were signs of meningeal irritation. Ten patients (42%) had transient disturbance of consciousness, and nine (38%) of these were somnolent; only one patient, who had a massive hematoma, was stuporous. When the hematoma extended to the internal capsule, the patient showed motor disturbance (38%). Two patients (8%) had Horner's sign, five (21%) exhibited diminished activity, and one (4%) suffered anosognosia. The volume of the intracerebral hematoma averaged 4.7 ml and was less than 5 ml in 17 patients (71%). In 20 patients (83%), the hematoma was confined to the head of the caudate nucleus. The hemorrhage tended to rupture into the anterior horn of the lateral ventricle, and in nearly all cases (96%), intraventricular hematoma was observed. Seventeen patients (71%) underwent cerebral angiography. There were no instances of dilation of the recurrent artery of Heubner. Twenty patients (83%) were treated conservatively. Continuous ventricular drainage was employed in four patients (17%), and ventriculoperitoneal shunting in three (13%). However, it was judged retrospectively that continuous ventricular drainage had been necessary in only two cases in which disturbance of consciousness was progressed due to acute hydrocephalus.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Respiratory fluctuations of the human pupil.

We simultaneously recorded respiration and pupil size in six normal subjects with an age range of 23-40 years (mean = 30.1), to study the relationship between the respiratory rhythm and changes in pupil size. In all subjects, respiratory fluctuations of the pupil (inspiratory mydriasis and expiratory miosis) were observed during normal spontaneous respirations. The amplitude of these pupillary changes was closely proportional to the tidal volume.

Adult↗