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Biomedical subjects

M Arai

Publications and source records attributed to M Arai.

At least 289 records · Page 16Linked to original sources
PubMed1996

Vestibular training for acute unilateral vestibular disturbances: its efficacy in comparison with antivertigo drug.

We carried out a clinical trial on the treatment of acute unilateral vestibular disturbances (AUVD) without typical Meniere's disease and benign paroxysmal positional vertigo. Two therapy groups were selected: vestibular training (VT) with drug therapy and drug administration alone. After the experimental period of 8 weeks, all patients were classified into two groups depending on the methods of treatment, and the clinical courses of the patients were compared statistically. It was confirmed statistically by global judgments of symptoms and signs that improvement rates were higher in the group treated by VT with medication than the improvement rate in the group with medication alone. It is concluded that VT is effective for early relief from vestibular ataxia.

Adult↗
PubMed1996

Optokinetic after-nystagmus in the human: a comparative study between normals and patients with peripheral vestibular and central disorders.

The purpose of this study was to classify various patterns of optokinetic after-nystagmus (OKAN) appearing in normal subjects, and to investigate the difference of OKAN between 147 normal subjects and 55 patients suffering from central nervous system (CNS) or peripheral vestibular disorders, in which 18 CNS disorders and 37 peripheral vestibular diseases were included. Data was divided into three categories by duration of the 1st phase of OKAN, i.e. hypo-response below 10 sec, middle response between 10 and 60 sec and hyper-response above 60 sec. The patterns of OKAN were then classified into six types with nine subtypes according to the following classification. All combinations of duration times of the 1st phase of OKAN toward both directions were then classified into six types, i.e. type 1, bilateral middle responses; type 2, bilateral hyper-responses; type 3, bilateral hypo-responses; type 4, unilateral hypo-response with contralateral middle response; type 5, unilateral hypo-response with contralateral hyper-response; and type 6, unilateral middle response with contralateral hyper-response. Moreover, subtypes "a" and "b" indicated symmetric and asymmetric in both types 1 and 2. Namely, if a relative value of the difference between bilateral responses against the sum of those was less than 20%, it was called "symmetric", otherwise, "asymmetric". Type 3 was divided into two subtypes: no response (3a) and hypo-response (3b). Results were summarized as follows. All combinations of horizontal OKAN toward both sides appeared in the 147 normal subjects. The incidence of each type, i.e. 1a, 1b, 2a, 2b, 3a plus 3b, 4, 5 and 6, was 10.9, 15.0, 2.7%, 1.4%, 25.2%, 31.3%, 4.1% and 9.5%, respectively. The incidence of type 3, type 3a in particular, was higher in patients than in the normals (p < 0.001). Also, the incidence of type 4 in normals was significantly higher than that of the patients (p < 0.01). Caloric tests revealed unilateral and bilateral canal pareses (CP) in 44 of 52 patients. The incidence of type 3 in the group of patients with CNS disorders was higher than those with peripheral vestibular disorders (p < 0.01). The 2nd phase of OKAN appeared in only nine of the 147 normals and in nine of the 55 patients. However, the 3rd phase of OKAN was observed in only one patient, the duration of which was 80 sec. The appearance rate of the 2nd phase of OKAN in patients was significantly higher than in the normal subjects (p < 0.05).

Adult↗
PubMed1996

Initial symptoms and retrospective evaluation of prognosis in Menière's disease.

Clinical studies on an initial symptom and a long-term course of vertigo and hearing impairment and retrospective evaluation of the prognosis were performed in Menière's disease. One hundred and fifty-one patients (67 males and 84 females) with Meniere's disease were treated in the Neuro-otological clinic, Kitasato University Hospital from 1990 to 1995. Ages ranged from 17 to 77 years (mean 47.3 years) at the onset of the disease when the first vertigo attack occurred. There were 106 (70.1%) in their 30s, 40s and 50s, and 28 (18.5%) aged 60 years or over. Seventy-eight patients visited the clinic within one year of the onset of the disease, but the mean interval was 4 years and 5 months (the longest was 25 years). The mean duration time for the follow-up studies from the time of their first visit to the hospital was 2 years and 5 months. The bilateral ears were invaded in 19 patients (12.6%) and the mean length of their time course was 9 years and 10 months which is longer than the length in unilateral cases. Several important key points for diagnosis of Menière's disease were investigated in 28 of the 151 cases who had been followed up successfully over a relatively long time course (the mean follow-up time was 7 years and 3 months). Fluctuated or stational cochlear signs, such as tinnitus, hearing impairment and/or fullness in the ear, had started prior to the onset of the first vertigo attack in 17 (61%) of 28 cases. Vertigo without cochlear sign appearing at the onset and cochlear signs were combined later in six (21%) of the 28 cases. Only five (18%) of the 28 cases had vertigo combined with a cochlear sign simultaneously at the onset of the disease. The affected ear was on the left in 15 cases and on the right in seven of 22 unilateral cases. In six bilateral cases the left ear was the first to be invaded in four out of six cases. The interval between the first and second attacks was over 1 year in six of the 28 cases and over 6 months in 10 of the 28 cases. Nine out of the 28 patients had recurrence of vertigo attacks during the first month and five of the nine had a cluster of attacks in the first month. Our study of 28 patients over a long time course revealed eight patients (28.6%) free from the disease. These patients had no recurrence of vertigo for more than 2 years after their last attack, and sixteen (57.1%) of the 28 patients had no recurrence of vertigo for more than 1 year. However, a long period of relief time of more than 2 years in 11 of the 28 patients and a period of more than 1 year was noticed in 16 of the 28 patients. Hearing levels at the middle and low frequencies in the first hearing test were compared with the last test. The mean of hearing levels changed from 38.1 to 36.2 dB after 2 years and 1 month in six cases with the right ear affected and from 34.1 to 45.3 dB after 5 years and 3 months in 15 cases with the left ear affected, but in seven cases with bilateral diseased ears the hearing in both ears became worse, from 25.5 to 57.1 dB in the right ear and from 30.5 to 53.6 dB in the left ear during a period of more than 10 years. These clinical findings should be utilized for diagnosis at the onset of Menière's disease to determine the interval for observation in order to evaluate the efficacy of treatment.

Adolescent↗
PubMed1996

Effectiveness of fibronectin in myringoplasty using temporal fascia.

A study of myringoplasty with temporal fascia homograft employing fibronectin was conducted in 14 ears in which the same myringoplasty procedure without fibronectin (1-5 times) had failed to afford closure of tympanic membrane perforation. Closure was obtained in eight ears. These results suggest that fibronectin is effective in myringoplasty using treated temporal fascia homograft.

Adult↗
PubMed1996

A-72363 A-1, A-2, and C, novel heparanase inhibitors from Streptomyces nobilis SANK 60192, II. Biological activities.

Inhibitory activities of A-72363 A-1, A-2 and C, the diastereomers of a neuraminidase inhibitor siastatin B, against various glycosidases were tested in comparison to siastatin B. Despite these compounds differing only in their configuration, each compound showed strikingly different specificities towards the various glycosidases tested. A-72363 C inhibited bovine liver beta-glucuronidase and tumor cell heparanase with IC50 values of 1.6 microM and 12 microM, respectively.

Animals↗
PubMed1996

[Analysis of factors which affect the measurement of factor VIII inhibitor by Bethesda method].

Factor VIII neutralizing antibody (factor VIII inhibitor) sometimes develops in the patients with hemophilia A who are treated with factor VIII concentrates and more rarely in non-hemophilic individuals as auto antibody. Factor VIII inhibitor titer is most commonly measured by Bethesda method in which the sample is mixed with normal pooled plasma as a source of factor VIII for 2-hour incubation followed by measurement of residual factor VIII activity. Because of its simplicity and accessibility of normal pooled plasma, Bethesda method is widely used in clinical laboratories. However, the reproducibility of the assay is not generally considered to be satisfactory and measurement of inhibitor units varies among laboratories. In the present study, the factors which affect the measurement of Bethesda method were assessed. The reproducibility of Factor VIII activity showed better in a factor VIII dose dependent manner and varies according to clotting threshold of the sample that is analyzed by an automated coagulation equipment and a desktop computer. The reproducibility of inhibitor measurement was worse in the inter-assay than in the intra-assay. The assay fluctuation of the measurement of lower inhibitor units tends to be more evident when the sample of 0.39 to 2.39 BU/ml were tested. The factor VIII content in the normal pooled plasma did not affect the measurement of factor VIII inhibitor units in the range of 0.8 to 1.2 U/ml. The buffers retained factor VIII in the control sample during the 2-hour incubation better in the order of imidazole buffer, bernard buffer, Tris-HCl buffer and saline.

Adult↗
PubMed1996

[Motor initiation difficulty of right upper extremity induced by tactile-stimulation after infarction in the left anterior cerebral artery territory].

We report a patient who manifested motor initiation difficulty of the right upper extremity, which was caused by tactile-stimulation on his right palm or back. The patient was a 62-year-old right-handed man, who showed reduction of spontaneous speech, slight paresis in the right lower extremity, and left unilateral ideomotor apraxia. He initially showed grasping reflex in the right hand, which disappeared in a month. MRI revealed infarction in the left medial frontal lobe and anterior-half of the corpus callosum. He complained that he was not able to initiate to move his right hand after his right palm or back touched something. He showed no paresis, no abnormal muscle tonus, no involuntary movement. Detailed examination revealed that it was an initiation disturbance caused by tactile-stimulation on his right palm or back. We concluded that this phenomenon, motor initiation difficulty, is one of the disturbances among motor process such as motor initiation, maintainance, and termination. The medial frontal lobe seems to manage the execution of motor process, therefore, lesions in the frontal lobe cause disturbance of motor process. And tactile-stimulation has a close relation to the reaction through the medial frontal lobe, thus, frontal lobe lesion may cause a misinteraction which retrieves a wrong reaction from a certain stimulation.

Arm↗
PubMed1996

Specific cross-reaction of IgG anti-phospholipid antibody with platelet glycoprotein IIIa.

To study the pathological functions of anti-phospholipid (anti-PL) antibodies, we have analyzed their effect on platelet function. We identified an IgG anti-PL mAb, designated PSG3, which cross-reacted specifically with glycoprotein (GP) IIIa in human platelets and inhibited platelet aggregation. PSG3 bound also to certain polyanionic substances, such as double-stranded DNA, heparan sulfate, dextran sulfate and acetylated-LDL, but not to other polyanionic substances. The binding of PSG3 to GPIIIa was completely inhibited by heparan sulfate and dextran sulfate, indicating that PSG3 recognizes a particular array of negative charges expressed on both GPIIIa and the specified polyanionic substances. Since neither neuraminidase- nor endoglycopeptidase F-treatment of GPIIIa had any significant effect on the binding of PSG3, this array must be located within the amino acid sequence of GPIIIa but not in the carbohydrate moiety. Reduction of the disulfide bonds in GPIIIa greatly reduced its reactivity, suggesting that the negative charges in the epitope are arranged in a particular conformation. PSG3 inhibited platelet aggregation induced by either ADP or collagen, it also inhibited fibrinogen binding to activated platelets in a dose-dependent fashion. PSG3, however, did not inhibit the binding of GRGDSP peptide to activated platelets. These results suggest that the PSG3 epitope on GPIIIa contains a particular array of negative charges, and possibly affects the fibrinogen binding to GPIIb/IIIa complex necessary for platelet aggregation.

Amino Acid Sequence↗
PubMed1996

[Changes of factor XIII a and b subunit in patients with disseminated intravascular coagulation syndrome].

Factor XIII is composed of two distinct proteins, a and b subunit. The dimers of each subunit form a tetrameric complex of a2b2 in plasma. Two separate ELISA systems were developed to measure either factor XIII a or b subunit in plasma. Sensitivity of the ELISAs was 3.0% of factor XIII a and b subunit in normal plasma. The ELISA for factor XIII b subunit quantitate free b2 and a2b2 complex in a equimolar manner. In order to evaluate the changes of each factor XIII subunit in a state of hypercoagulation, 16 plasmas from proteins with disseminated intravascular coagulation syndrome (DIC) were examined. Factor XIII a and b subunit showed 56.5 +/- 30.5% and 63.4 +/- 22.5%, respectively in the DIC subjects compared to normal pooled plasma as 100%. The ratio of factor XIII a and b subunit (a/b ratio) were between 0.5 and 1.0 in DIC cases which improved after treatment. However, the ratios were less than 0.5 in the cases with DIC which deteriorated in spite of the treatment. These results suggest that the a/b ratio would indicate the prognosis of patients with DIC.

Biomarkers↗
PubMed1996

Decrease of mesangial matrix after immunosuppressive therapy in children with reversible membranoproliferative glomerulonephritis type I.

We followed the course of membranoproliferative glomerulonephritis (MPGN) type I after immunosuppressive therapy in 10 children. At diagnosis all patients had abnormal urinary findings. After a mean follow-up of 14 years all but one patient showed normal urinalysis and renal function. Glomerular morphometry revealed an increase in the ratio of mesangial matrix area to glomerular area (M/G%) in all patients. After immunosuppressive treatment, a second biopsy was performed, which showed a significantly decreased M/G% in 4 patients. In 3 of the remaining 6, the mean M/G% was significantly lower in a third biopsy when compared with the first. In addition, there was a negative correlation between M/G% and duration from onset disease to biopsy (r = -0.46, p <0.05). Fifteen biopsies (6 initial and 9 repeat biopsies) were examined for the staining of various extracellular matrices. In the initial biopsy type IV collagen, type V collagen and fibronectin were increased in expanded mesangial areas. Type III collagen was found segmentally in a few biopsies only. M/G% correlated with the grade of type IV collagen, type V collagen and fibronectin staining. These findings suggest that a reversible clinical course of MPGN type I in children is paralleled by a decrease of mesangial matrix expansion.

Adolescent↗
PubMed1996

A novel mutation Gly 1672-->Arg in type 2A and a homozygous mutation in type 2B von Willebrand disease.

Genetic materials from 16 unrelated Japanese patients with von Willebrand disease (vWD) were analyzed for mutations. Exon 28 of the von Willebrand factor (vWF) gene, where point mutations have been found most frequent, was screened by various restriction-enzyme analyses. Six patients were observed to have abnormal restriction patterns. By sequence analyses of the polymerase chain-reaction products, we identified a homozygous R1308C missense mutation in a patient with type 2B vWD; R1597W, R1597Q, G1609R and G1672R missense mutations in five patients with type 2A; and a G1659ter nonsense mutation in a patient with type 3 vWD. The G1672R was a novel missense mutation of the carboxyl-terminal end of the A2 domain. In addition, we detected an A/C polymorphism at nucleotide 4915 with HaeIII. There was no particular linkage disequilibrium of the A/C polymorphism, either with the G/A polymorphism at nucleotide 4391 detected with Hphl or with the C/T at 4891 detected with BstEII.

Arginine↗
PubMed1996

[Fisher's syndrome with profound hypotension].

A case of Fisher's syndrome was described in which profound hypotension was encountered. A 70-year-old previously healthy female developed diplopia and unsteady gait following an upper respiratory infection. On admission, her blood pressure was 140/60 mmHg. Adduction of the left eye and elevation of the right eye were limited. Other cranial nerve functions and muscle strength were intact. She had gait ataxia with negative Romberg sign. Tendon reflexes were hypoactive. The cerebrospinal fluid, electrocardiography, and cranial MR imaging were unremarkable. Her serum had a high titer of IgG anti-body. After admission she developed bilateral internuclear ophthalmoplegia and severe gait ataxia. During double filtration plasmapheresis, her systolic pressure fell down to 60 mmHg. To maintain her systolic pressure between 90 and 120-mmHg supine, infusion of lactated Ringer solution (3,000-3,500 ml/day), dopamine hydrochloride (10-12 micrograms/kg/min), and norepinephrine (50-90 ng/kg/min) was needed for 3 weeks. There was no evidence of denervation supersensitivity. Echocardiography demonstrated normal cardiac output, suggesting that decreased vascular resistance was responsible for her hypotension. In Guillain-Barré syndrome, cardiovascular dysautonomia is frequently encountered and is occasionally related to sudden death. In contrast, Fisher's syndrome with cardiovascular dysautonomia has been rarely reported. Cardiovascular functions should be monitored in every patient with Fisher's syndrome.

Aged↗
PubMed1996

Factor VIII inhibitor antibodies with C2 domain specificity are less inhibitory to factor VIII complexed with von Willebrand factor.

In order to clarify the potential role of von Willebrand factor (vWf) in attenuating the inactivation of factor VIII (fVIII) by those antibodies with C2 domain specificity, we investigated a panel of 14 human antibodies to fVIII. Immunoblotting analysis localized light chain (C2 domain) epitopes for four cases, heavy chain (A2 domain) epitopes in five cases, while the remaining five cases were both light and heavy chains. The inhibitor titer was considerably higher for Kogenate, a recombinant fVIII concentrate, than for Haemate P, a fVIII/vWf complex concentrate, in all inhibitor plasmas that had C2 domain specificity. In five inhibitor plasmas with A2 domain specificity and in five with both A2 and C2 domain specificities, Kogenate gave titers similar to or lower than those with Haemate P. The inhibitory effect of IgG of each inhibitor plasma was then compared with recombinant fVIII and its complex with vWf. When compared to the other 10 inhibitor IgGs, IgG concentration, which inhibited 50% of fVIII activity (IC50), was remarkably higher for the fVIII/vWf complex than for fVIII in all the inhibitor IgGs that had C2 domain reactivity. Competition of inhibitor IgG and vWf for fVIII binding was observed in an ELISA system. In 10 inhibitors that had C2 domain reactivity, the dose dependent inhibition of fVIII-vWf complex formation was observed, while, in the group of inhibitors with A2 domain specificity, there was no inhibition of the complex formation except one case. We conclude that a subset of fVIII inhibitors, those that bind to C2 domain determinants, are less inhibitory to fVIII when it is complexed with vWf that binds to overlapping region in the C2 domain.

Antibody Specificity↗
PubMed1996

[Home care that meets the wishes of patients with terminal stage cancer and their families].

As our ward is a general surgical ward, we formerly had difficulties providing appropriate care for patients with terminal cancer. To solve the problem, we have formed a nursing study group in order to provide home care that would meet the wishes of such patients and their families. Our specific approach was as follows: 1) preparation of a form on which patient information is collected; 2) a support system for home care (such as pain control and home parenteral nutrition; and 3) a solid collaboration system between ward nurses and visiting nurses. Such a program enables us to understand the wishes of patients and families and to provide various support where needed. The project helps to lessen the anxiety and the burden that patients and families feel in home care, and improve the quality of life (QOL).

Aged↗
PubMed1996

[A case of adult Reye's syndrome with favorable outcome despite status epilepticus].

A case of adult Reye's syndrome is described. A previously healthy 17-year-old man developed convulsions 2 days after resolution of an upper respiratory infection with parainfluenza virus type 3. During the preceding infection, he took aspirin. On admission, he was drowsy. There was no focal signs. Cranial CT scan was unremarkable. A lumbar puncture revealed an opening pressure of 180 mm H2O; the cerebrospinal fluid was acellular with normal protein level. Serum chemistry showed elevated transaminase activities and normal bilirubin level. Blood ammonia level was high; urea and citrulline levels were abnormally low. These abnormalities disappeared later, suggesting transient cysfunction of mitochondrial urea-cycle enzymes. Free and acyl carnitine levels were unremarkable. Both metabolic acidosis and ketonuria were absent. Thus, a variety of aminoacidurias and organic acidemias are unlikely. All these findings meet diagnostic criteria for Rye's syndrome proposed by the CDC of the USA. Status epilepticus was treated with intravenous infusion of thiamylal sodium. He was treated with hypertonic glucose solution and osmotic diuretic. Three months after the onset of the illness, his convulsions were controlled only with zonisamide, clonazepam, and carbamazepine. He had motor dysfunctions. This case is unique in that a patient with adult Reye's syndrome and status epilepticus favorably recovered.

Adolescent↗
PubMed1996

Properties of the elastic modulus from buccal compact bone of human mandible.

The aim of this study was to elucidate the elastic modulus of the mandible, which is an important factor in analysis of its physical dynamics. To meet this need, three point bending tests of small bone specimens were performed. The authors concluded that the elastic modulus of the mandible varied with site and orientation. When the specimens were obtained from regions paralleling the mandibular plane, the values in the lower portions were generally higher than those in the upper portions, indicating that these regions are more rigid. The elastic modulus in the marginal portions of the mandible, such as the mandibular plane, had comparatively high values. Relatively lower values were found as the angle to the margin of the mandible increased. In the incisal and premolar regions, anisotropic characteristics approximated those of unidirectional fiber reinforced composite materials. In the molar regions, there was a broad distribution of values, reflecting the complexity of mandibular structure.

Anisotropy↗
PubMed1995

Effect of a novel histamine H2 receptor antagonist, IT-066, on acute gastric injury induced by ischemia-reperfusion in rats, and its antioxidative properties.

The effect of a novel histamine H2 receptor antagonist IT-066 (3-amino-4-[4-[4-(1-piperidinomethyl)-2-pyridyloxy]-cis-2-++ +butenylamino]- 3-cyclobutene-1,2-dione hydrochloride), on acute gastric mucosal injury induced by ischemia-reperfusion was investigated from the standpoint of oxygen radical-mediated lipid peroxidation in rats. Ischemia-reperfusion injury was produced in the rat stomach by applying a small vascular clamp to the celiac artery for 30 min and subsequent removal of the clamp for 60 min. The decrease in gastric mucosal blood flow was not influenced by treatment with IT-066. The antiulcer activity of IT-066 was demonstrated in this injury after intragastric ingestion as well as after intravenous injection. IT-066 significantly inhibited this injury in the presence of exogenous HCl. The mucosal protection by IT-066 was not reversed by pretreatment with indomethacin or nitric oxide synthase inhibitor. The increase in lipid peroxides in the gastric mucosa after ischemia-reperfusion was significantly inhibited by the intragastric treatment with IT-066 at doses of 1.0 and 3.0 mg/kg. The total area of erosions closely paralleled the accumulation of lipid peroxide with a significant correlation. A spin trapping method using 5,5-dimethyl-1-pyrroline-N-oxide showed that IT-066 scavenged superoxide radical and hydroxyl radical generated by the hypoxanthine-xanthine oxidase system and the hydrogen peroxide-ferrous iron system, respectively. IT-066 also significantly inhibited the in vitro increase of lipid peroxide in the gastric mucosal homogenates induced by a free radical initiator. These results suggest that the protective effect of IT-066 against ischemia/reperfusion-induced gastric mucosal injury may result in part from its antioxidative properties.

Animals↗