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Biomedical subjects

S Oda

Publications and source records attributed to S Oda.

At least 145 records · Page 8Linked to original sources
PubMed1997

Surgical indications in patients with an intracerebral hemorrhage due to ruptured middle cerebral artery aneurysm.

In this retrospective study, the authors analyzed surgical outcomes in patients who suffered an intracerebral hemorrhage (ICH) as a result of a ruptured middle cerebral artery aneurysm. They studied 47 patients who underwent early aneurysm surgery and hematoma evacuation within 24 hours after onset of ICH. The types of ICH were classified into three groups according to their appearance on computerized tomography scanning: 1) temporal ICH; 2) intrasylvian hematoma; and 3) ICH with diffuse subarachnoid hemorrhage (SAH). Overall, 25 patients (53%) achieved a favorable outcome and 18 (38%) died. Factors that could be used to predict a favorable outcome included age less than 60 years, temporal ICH, World Federation of Neurological Surgeons Grade II or III, absence of a surgical complication, and a hematoma volume less than 25 ml. In the patients with temporal ICH, eight of nine patients achieved a good recovery and no patient developed a surgical complication or delayed ischemic deficit. The significant prognostic factor in patients with an intrasylvian hematoma was surgery within 6 hours after onset of symptoms. In patients with temporal ICH or intrasylvian hematoma, the results of the initial neurological examination did not accurately predict outcome. On the other hand, in patients with ICH and diffuse SAH, those patients who developed an ICH with a volume greater than 25 ml had a poor prognosis. These results indicate that aggressive surgical treatment should be performed in patients with a temporal ICH or an intrasylvian hematoma, regardless of the neurological findings on admission; in patients with ICH and diffuse SAH, a careful review of surgical indications is required.

Aged↗
PubMed1997

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents. Special references to bacteria isolated between July 1995 and June 1996].

Isolated bacteria from infections in general surgery during the period from July 1994 to June 1995 were investigated in a multicenter study in Japan, and the following results were obtained. One hundred and sixty-four strains were isolated from primary infections, and 202 strains were isolated from postoperative infections. From primary infections, anaerobic Gram-positive bacteria were predominant, while from post operative infections, aerobic Gram-positive bacteria were predominant. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus faecalis was the highest, followed by that of Staphylococcus aureus from postoperative infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among anaerobic Gram-negative, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by Enterobacter spp. and Klebsiella spp. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. We noticed that MICs of cefazolin against three out of 23 strains of E. coli were higher than 100 micrograms/ml. Among anaerobic bacteria, there were many resistant strains against penicillins and cephems with MICs higher than 100 micrograms/ml, and the same trend was observed among other Bacteroides spp. and Prevotella spp.

Bacterial Infections↗
PubMed1997

[A case of dyskeratosis congenita with acute interstitial pneumonia].

This is a rare case of Dyskeratosis Congenita (DC) with acute interstitial pneumonia. A 51-year-old man with DC was admitted to our hospital because of cough, sputum and fever. Chest X-ray film showed ground glass opacities in all lung fields for a while steroid's therapy proved effective, but about seven months later the patient's condition became serious. Methylprednisolone, cyclophosphamide and mechanical ventilation therapy were not effective. He died and an autopsy was performed. The lung specimen showed Organizing Diffuse Alveolar Damage, and some parts pointed to bacterial infection. But Pneumocystic carinii pneumonia and Fungal infections were not found. It is therefore necessary to conduct intensive examinations of lung involvement of patients with Dyskeratosis Congenita.

Acute Disease↗
PubMed1997

[Self-efficacy and related factors related in Parkinson's disease patients].

This study was designed to assess self-efficacy and the factors leading to higher self-efficacy in Parkinson's disease patients, as measured by General Self-Efficacy Scale (GSES). Questionnaires were mailed to patients with Parkinson's disease in Tokyo. This study surveyed 73 male and 70 female patients. Approximately 66.5% of the patients fell into the low self-efficacy group. Data was divided into 3 groups (high, moderate and low) and evaluated statistically. Approximately 66.5% of the patients fell into the low self-efficacy group. Patients in the high self-efficacy group exhibited the following features: Males: 1) The male patients in the high self-efficacy group tended to belong to more groups and had less trouble than any other groups in coping with their daily lives; 2) they generally had people to turn to for mental support outside their families, and for their daily life inside or outside their families; 3) they also felt confident that they had sufficient understanding of better life styles and how to exercise. Females: 1) The female patients in the high self-efficacy group tended to go out more often than any other groups and had places to go where they could practice hobbies and exercise; 2) they generally had people outside their families to turn to for mental support; 3) their subjective symptoms, such as freezing and dysarthria, tend to be less acute than in the moderate or low self-efficacy patients. 4) had les trouble than any other groups in coping with their housing accommodations; 5) they also felt confident that they understood how to exercise. In order to increase self-efficacy among Parkinson's disease patients, this study suggests that support, both social and psychological, and providing health education, are important.

Aged↗
PubMed1997

Ectopic bone formation by biphasic calcium phosphate (BCP) combined with recombinant human bone morphogenetic protein-2 (rhBMP-2).

We investigated ectopic bone formation by biphasic calcium phosphate (BCP) combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) in the rat dorsum. Under reduced pressure, rhBMP-2 was adsorbed onto BCP, which consisted of 80% beta-tricalcium phosphate and 20% hydroxyapatite uniformly distributed in granules. Twenty Wistar rats were separated into 4 groups consisting of 5 animals each dosed with 2, 10, and 50 micrograms/700 microliters of rhBMP-2 and a control group (BCP only). Pieces of the BCP-BMP complex or only BCP were implanted under the dorsal skin of the rats. Histological sections were examined three weeks later. New bone was formed in all rats given 50 micrograms doses, but not in the 2 micrograms and control groups. These results indicated that BCP combined with rhBMP-2 induced ectopic bone formation without additional carriers. Therefore, BCP granules alone can function as carriers for rhBMP-2 to induce bone formation.

Adsorption↗
PubMed1996

Involvement of Fas ligand and Fas-mediated pathway in the cytotoxicity of human natural killer cells.

The cytotoxicity of NK cells has been thought to be mediated mainly by the perforin-dependent pathway. We investigated the involvement of Fas-mediated pathway in the killing activity of purified human CD3-, CD16+ NK cells. Fas ligand mRNA was expressed in freshly isolated NK cells. Apoptosis, which was identified by the fragmented chromatin in individual cells, was induced in the cells that expressed high levels of Fas via direct NK-to-target cell interaction or Ab-dependent cell-mediated cytotoxicity, even in Ca(2+)-free medium, in which perforin pores are known not to be formed. Apoptosis in both the presence and absence of external Ca2+ was inhibited by Fab of an anti-Fas mAb. Transfection of the Fas gene in target cells facilitated the induction of apoptosis, compared with the parental cell line. The function of the Fas-mediated pathway in the coexistence of the perforin-dependent pathway was examined in 10 cell lines expressing different levels of Fas by Ca2+ imaging and morphologic observation of single cells. With a certain boundary level, low or high levels of Fas expression in target cells were correlated to a great degree with either acute necrosis due to severe membrane damage after NK-target cell contact or apoptosis at a later period, respectively. We concluded that Fas ligand/Fas interaction is present and plays a significant role in the human NK cell-induced apoptosis.

Antibodies, Monoclonal↗
PubMed1996

The dilute-lethal (dl) gene attacks a Ca2+ store in the dendritic spine of Purkinje cells in mice.

The absence of smooth endoplasmic reticulum (SER) in the dendritic spine of Purkinje cells was found in dilute-lethal (dl) mouse cerebella as detected by immunohistochemistry using anti-inositol 1,4,5-triphosphate receptor antibody and electron microscopy. Since SER in the spine has been suggested to play a crucial role for synaptic regulation as an intracellular Ca2+ store (for reviews, see [Miller, R.J., Prog. Neurobiol., 37 (1991) 255-285: Simpson, P.B., Challiss, R.A.J. and Nahorski, S.R., Trends Neurosci., 18 (1995) 299-306]), a neurological defect, characterized by clonic convulsions with opisthotonus and ataxia, in the dilute-lethal mouse with homozygous trait may be attributable to the absence of SER in the dendritic spine of Purkinje cells.

Animals↗
PubMed1996

An integrated microsatellite length analysis using an automated fluorescent DNA sequencer.

Analyzing microsatellite instability (MI) in malignant tumors is thought to be useful for screening cancer patients to identify those patients with a higher risk of developing second malignant tumors. In this paper, we report a new, accurate, and efficient method of detecting MI using an automated fluorescent DNA sequencer and a computer that automatically calculates the size, height, and area of each fluorescent product, making it possible to assess MI more accurately and more rapidly. The primers for amplification of each microsatellite locus are labeled by two different fluorescent dyes, rox (red) and fam (blue). The rox-labeled primer was used for the tumor, whereas the fam-labeled primer was used for the corresponding normal tissue. Two amplified products from both the tumor and the normal tissue were co-loaded into a single lane of the sequencing gel and were analyzed. MI could be detected based on the presence of different waving patterns. Furthermore, several loci could also be analyzed simultaneously for MI in a single lane. Using this method, we examined the frequency of MI in gastric cancer. The results showed that 5 of 22 (22.7 %) gastric cancers were MI-positive, which corresponds to the findings of previous reports that used the radioisotopic method. The improved method may open up the possibility of performing routine examination of MI in many cancer patients and offers hope for the potential clinical application of Ml analysis as a follow-up evaluation of cancer patients.

Chromosome Aberrations↗
PubMed1996

Endoplasmic reticulum is missing in dendritic spines of Purkinje cells of the ataxic mutant rat.

Dilute-opisthotonus (dop) is a spontaneous ataxic mutation in the rat, regulated by an autosomal recessive gene. Immunohistochemical staining with anti-inositol 1,4,5-trisphosphate receptor antibody and electron microscopic examinations revealed that the endoplasmic reticulum in dendritic spines of Purkinje cell was missing in the ataxic rat. This could impair the intracellular signal transduction in the parallel fiber-Purkinje cell synapse, and be a cause of the severe ataxic movement.

Animals↗
PubMed1996

Regulation of preimplantation development of mouse embryos: effects of inhibition of myosin light-chain kinase, a Ca2+/calmodulin-dependent enzyme.

We have examined the effects of ML-9 and wortmannin, which are, respectively, specific reversible and irreversible inhibitors of myosin light-chain kinase, a Ca2+/calmodulin-dependent enzyme, on preimplantation development of the mouse in an attempt to establish a regulatory role for this enzyme in preimplantation development. When late two-cell stage embryos were treated continuously with ML-9 or wortmannin at a concentration of 0, 1, 5, 10, or 15 microM, compaction and formation of the blastocyst were inhibited in a dose-dependent manner. Stage-specific treatment with ML-9 at 25 microM induced stage-specific responses of embryos after the eight-cell stage during the processes of compaction and cavitation. These morphological responses included aborted compaction, decompaction of compacted embryos, and the inability of embryos to form a cavity. These morphological effects were reversible, but, since cell proliferation was inhibited, the "recovered" embryos were small. Counting of cells on day 4 of culture, in both continuously treated and stage-specifically treated embryos, showed that the effect of ML-9 on cell proliferation was also dose-dependent. Wortmannin also had stage-specific effects at 15 microM, but these effects were irreversible and were more deleterious than those of ML-9. With neither inhibitor was there any apparent effect at the two-cell or the four-cell stage, although wortmannin inhibited cell division when applied stage-specifically at the four-cell stage. These results indicate that myosin light-chain kinase may be an important enzyme in the first steps of differentiation and in the maintenance of the differentiated state during preimplantation development of the mouse.

Androstadienes↗
PubMed1996

Interlimb co-ordination of force and movement-related cortical potentials.

The question we asked in this study was how the cerebral hemispheres are coordinated when the two hands simultaneously generate force at the same level. Interlimb co-ordination of contractions at 20% of the maximal level was investigated during bilateral (BL) and unilateral (UL) handgrip in eight male right-handed subjects. The accuracy as determined by the force error was larger during BL than during UL for the left hand only. The movement-related cortical potential (MRCP) of C3 (left precentral cortex) was studied during UL right and BL handgrip and the C4 (right precentral cortex) during UL left and BL handgrip. At the phase of the readiness potential (-1.0 to -0.6 s prior to the force onset), similar levels of correlation in the C3 (C4) MRCP amplitudes (P < 0.05) between UL right (UL left) and BL handgrip were observed. At the phase of the negative slope (-0.6 to -0.2 s) and the motor potential (-0.2 to -0.05 s), C3 revealed almost the same levels of correlation as for the readiness potential, whereas in C4 a marked decrease was noted. Accordingly, from this study the force error and movement-related cortical potentials would indicate that the left dominant hemisphere is specialized not only for unilateral contractions but also for bilateral contractions.

Adult↗
PubMed1996

Cross-correlation studies of movement-related cortical potentials during unilateral and bilateral muscle contractions in humans.

A useful method of studying the degree of association between two signals of varying amplitude in the time domain is to use cross-correlation analysis. We applied this to the movement-related cortical potentials digitally filtered so as to eliminate the low frequency component before applying it during maximal unilateral left (UL L), unilateral right (UL R) and bilateral (BL) contractions in 11 right-handed subjects. The recording electrode sites were over the right and left motor cortex areas (C3 and C4). The BL condition revealed higher cross-correlation levels of cortical activities between the two hemispheres than in UL L or UL R contraction [UL L, r = 0.68 (SEM 0.05); UL R, r = 0.73 (SEM 0.03); BL, r = 0.76 (SEM 0.02)]. The UL R revealed a positive phase difference [5 (SEM 2) ms] when the maximal cross-correlation coefficient was shown and UL L showed a negative phase difference [5 (SEM 3) ms]. However, BL revealed a smaller phase difference [2 (SEM 1) ms] than that for UL. It was concluded that during maximal BL contraction cortical cellular activities in both hemispheres was more synchronized in amplitude and time course compared with maximal UL contractions. Our data suggested that central common drive existed between the right and left motor areas during the maximal BL handgrip contractions and the amplitude of potentials of both hemispheres was modified by the interhemispheric inhibition mechanism as reported in other studies.

Adult↗
PubMed1996

Early aneurysm surgery and dehydration therapy in patients with severe subarachnoid haemorrhage without ICH.

We prospectively analysed treatment results in patients with severe subarachnoid haemorrhage (SAH) who underwent early aneurysm surgery, and were managed by dehydration therapy. We studied a total of 31 patients with poor-grade SAH including 18 in grade IV, and 13 in grade V according to the WFNS classification system. Patients who were older than 70 years of age, or those with an intracerebral haemorrhage or absent brainstem response were excluded from this study. At surgery, clot evacuation from the peri-brainstem cisterns with/without external decompression was performed following obliteration of the aneurysmal neck. In the early postoperative period, patients were maintained in negative water balance using osmotic diuretics. When delayed ischaemic deficits had manifested themselves, the pulmonary wedge pressure and/or central venous pressure was immediately increased by the rapid injection of albumin until hypovolaemia reverted to normovolaemia with the continuous administration of dobutamine. The outcome at 3 months was good recovery in 16 (52%) patients, moderate disability in 3 (10%), severe disability in 5 (16%), a vegetative state in 1 (3%), and death in 6 (19%). We though that early aneurysm surgery and postoperative dehydration therapy in the acute stages of brain oedema resulting from primary brain damage are effective in the treatment of patients with severe SAH but reversible primary brain damage.

Adult↗
PubMed1996

Blood purification for prevention and treatment of multiple organ failure.

Blood purification has been applied conventionally as an artificial kidney or artificial liver in the management of patients with multiple organ failure (MOF), and most blood purifications have been performed intermittently. Recent advances in medical engineering made it possible to perform such blood purifications continuously (i. e., 24 hours a day, 7 days a week if necessary) even in critically ill patients. This modality is referred to as continuous renal replacement therapy (CRRT) or continuous blood purification (CBP). Among many kinds of CBP, continuous hemodiafiltration (CHDF) is most useful for management of MOF, as it can be performed without serious or hazardous side effects, and improvement can be expected with it. Recently, CHDF and polymyxin B immobilized endotoxin adsorption columns were used for the prevention or treatment of MOF, with the expectation that such therapy can be effective as a countermeasure against the pathophysiologic causes of MOF. Our data and that of others clearly indicate that continuous blood purification, such as with CHDF and endotoxin adsorption, can remove or decrease the blood levels of humoral mediators, including proinflammatory cytokines, and can improve tissue oxygenation, especially oxygen consumption (VO2) among critically ill patients including those with MOF. Blood purification is also useful in the careful management of fluid, electrolytes, and acid-base balance and for the removal of metabolic wastes. Blood purification is now considered to be one of the basic therapeutic tools of critical care, equal to nutritional support with total parenteral nutrition and respiratory support without a ventilator.

Critical Care↗
PubMed1996

Clinical significance of occult micrometastasis lymph nodes from patients with early gastric cancer who died of recurrence.

BACKGROUND: Even after curative resection of an early gastric cancer, some patients die of a recurrence. It is our view that patients with early gastric cancer who died of their disease had occult micrometastases in perigastric lymph nodes at the time of the original diagnosis. In an attempt to identify these micrometastases, lymph nodes dissected from early gastric cancer lesions were stained after operation with monoclonal antibody against cytokeratin, an essential constituent of the cytoskeleton of epithelial cells. METHODS: The 420 dissected lymph nodes from 34 patients with node-negative early gastric cancer who died of a recurrence were examined for the presence of tumor cells. We used immunocytochemical techniques and an antiserum to epithelial membrane antigen. The monoclonal antibody CAM 5.2 recognizes cytokeratin polypeptides (human cytokeratin numbers 8 and 18) commonly present in epithelial cells. Clinicopathologic characteristics and prognosis were determined for patients with cytokeratin-positive cells in the lymph nodes. RESULTS. Of 420 lymph nodes, 15 (3.6%) nodes and 23.5% (8 of 34) of the patients presented with cytokeratin-positive cells at the time of primary operation. The presence of cytokeratin positivity was not related to various clinicopathologic factors. The histologic stage of eight cytokeratin-positive cases was upstaged by the group of cytokeratin-positive lymph nodes from stage I to three of stage II, four of stage III, and one of stage IV, hematogenous recurrences were common, and the prognosis was poorer. CONCLUSIONS: Immunohistochemical techniques aid in identifying micrometastatic disease in lymph nodes missed in routine hematoxylin-eosin staining. Cytokeratin staining of the dissected lymph nodes is recommended to precisely determine tumor stage and prognosis for patients with early gastric cancer.

Adult↗
PubMed1996

Cytokeratin-positive cells in bone marrow for identifying distant micrometastasis of gastric cancer.

Direct evidence of tumour seeding in distant organs at the time of surgery for gastric cancer is not available. An immunocytochemical assay for epithelial cytokeratin protein may fill this gap since it is a feature of epithelial cells that would not normally be present in bone marrow. The bone marrow of 46 patients with primary gastric cancer was examined for tumour cells, using immunocytochemical techniques and antibody reacting with cytokeratin, a component of the intracytoplasmic network of intermediate filaments. The monoclonal antibody CK2 recognises a single cytokeratin polypeptide (human cytokeratin no. 18) commonly present in epithelial cells. The expression of tumour-suppressor genes p53 and RB for the primary lesion was also determined using the monoclonal antibodies PAb 1801 and 3H9 respectively, and the proliferating activity was determined by the Ki-67 antigen labelling index for MIB-1 antibody staining. Of these 46 patients, 15 (32.6%) presented with cytokeratin-positive cells at the time of primary surgery. The positive findings were related to the undifferentiated tissue type and to the prominent depth of invasion, but not to other clinicopathological factors. In 2 of 15 (13.3%) patients, the depth of invasion was limited to the mucosa. The metastatic potential to bone marrow did not relate to expressions of p53 and RB genes, or to the proliferating activity of MIB-1 staining for the primary lesion of gastric cancer. As tumour cells in bone marrow are indicative of the general disseminative capability of an individual tumour, this technique may be useful for identifying patients at high risk of metastasis from a gastric tumour.

Antibodies, Monoclonal↗
PubMed1996

Relationship between solvent inhalation and antisocial behavior: special emphasis on two types of violence seen in solvent abusers.

Organic solvent inhalation is a serious problem among youths in Japan. It induces physical and mental disorders, and is related closely to crime and delinquency. The relationship between solvent inhalation and antisocial behavior was investigated in 75 youths. The subjects were divided into three groups according to the level of violent behavior and the time of appearance: a non-violent group, a late-onset group (violence occurred after the start of inhalation) and an early-onset group (violence had occurred before the start of inhalation). Various parameters were compared among the groups. The late-onset group showed the following characteristics; (i) the frequency of inhalation was high, and many subjects experienced hallucinations and mood changes caused by inhalation; (ii) the family environment was characterized by conflict; and (iii) the subjects had strong psychological conflicts and showed dissociative coping with frustration. The violence, psychological conflict and dissociation in this group were found to be related to the inhalation, with familial conflict as a background. The violence in the early-onset group was considered to be the manifestation of a violent personality as the frequency of inhalation and the incidence of mental symptoms were both low. The subjects in this group showed weak psychological conflict and tended to be demanding of others when attempting to cope with frustration. Two types of violent behaviors in the teenagers who inhaled solvents were identified. The violence of solvent inhalers should be managed according to the type.

Administration, Inhalation↗