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Biomedical subjects

Y Katayama

Publications and source records attributed to Y Katayama.

At least 55 records · Page 3Linked to original sources
PubMed2003

Impairment of motor function after frontal lobe resection with preservation of the primary motor cortex.

We investigated the clinical course and characteristics of the motor deficits in patients who underwent surgical resection of the frontal lobe for tumorous lesions. Only patients who met the following criteria were included in the present study: 1) postoperative MRI revealed that resection of the frontal lobe involved the area closely adjacent to the primary motor cortex, but 2) the D wave of the corticospinal MEP did not decrease in amplitude below 50% of the original level during surgery. The extent of resection was classified into 4 groups. In Group A (6 cases), resection was limited within the area above the superior frontal sulcus and posterior to a line vertical to the line connecting the anterior and posterior commissures at the anterior commissure (AC vertical line). Resection was extended anterior to the AC vertical line in Group B (4 cases) or below the superior frontal sulcus in Group C (5 cases). In Group D (3 cases), resection was extended to both of these two boundaries. Severe motor paresis and/or apraxia of the upper and lower extremities were noted in all patients of Group D immediately after surgery. A complete recovery in the lower extremity was observed in these patients, while disturbance in the fine movements of the upper extremity remained for more than 1 year after the surgery. Disturbance in the fine movements and/or apraxia of the upper extremity were observed immediately after surgery in 2 of the Group A patients (33%), 2 of the Group B patients (50%) and 3 of the Group C patients (60%). However, a rapid recovery occurred in these patients, and only a subtle or mild disturbance remained for more than 1 year after the surgery in one of the Group B and one of the Group C patients. Permanent and severe motor deficit is rarely induced when resection of the frontal lobe is limited to only the SMA proper (corresponding roughly to Group A), the SMA proper and pre-SMA (corresponding roughly to Group B), or the SMA proper and premotor cortex (corresponding roughly to Group C), insofar as the primary motor cortex is preserved. Disturbance in fine movements of the upper extremity is frequently induced for the long term when wide areas of the SMA proper, pre-SMA as well as premotor cortex are resected altogether (corresponding roughly to Group D).

Adult↗
PubMed2003

Deep brain and motor cortex stimulation for post-stroke movement disorders and post-stroke pain.

Our experience of deep brain stimulation (DBS) and motor cortex stimulation (MCS) in patients with post-stroke movement disorders and post-stroke pain is reviewed. DBS of the thalamic nuclei ventralis oralis posterior et intermedius proved to be useful in more than 70% of patients with post-stroke involuntary movements (hemiballismus, hemichoreo-athetosis, distal resting and/or action tremor, and proximal postural tremor). The effect of DBS of the thalamic nucleus ventralis caudalis or internal capsule on post-stroke pain was usually disappointing. Excellent pain control can be achieved by MCS in approximately 50% of patients with post-stroke pain. In the course of clinical trials on MCS for the control of post-stroke pain, it was found that co-existent post-stroke involuntary movements (hemichoreo-athetosis and resting tremor) could also be controlled by MCS. Post-stroke involuntary movements, especially those in thalamic syndrome, are sometimes associated with post-stroke pain. In such disorders, involuntary movements are attenuated, but the pain in the same patients is often exacerbated by DBS of the thalamic nuclei ventralis oralis posterior et intermedius. MCS could be the therapy of choice under such circumstances. Subjective improvement of voluntary motor performance, which had been impaired in association with mild or moderate hemiparesis, was reported during MCS by approximately 20% of patients with post-stroke pain. Such an effect on voluntary motor performance appears to be caused by an inhibition of their rigidity. The reversibility of DBS and MCS makes them an important option for the control of post-stroke movement disorders and post-stroke pain.

Electrodes, Implanted↗
PubMed2003

Chronic stimulation of the globus pallidus internus for control of primary generalized dystonia.

Our experience of deep brain stimulation of the globus pallidus internus (GPi-DBS) for dystonia is summarized. A total of 5 patients with primary generalized dystonia underwent GPi-DBS. There were 3 males and 2 females. The age at onset of dystonia ranged from 8 to 45 years and the age at surgery for GPi-DBS ranged from 17 to 59 years. Two of the patients had been treated previously by bilateral thalamotomy or unilateral pallidotomy at other clinics and then developed new symptoms or recurrence. All were stimulated bilaterally. No surgical complications were encountered. The symptoms of dystonia were scored by the Burke-Fahn-Marsden dystonia rating scale (BFMDRS). The scores ranged from 18 to 62 before surgery. An improvement in the symptoms of dystonia was observed soon after the initiation of GPi-DBS, and additional progressive improvement was noted during a period of months or even years after surgery. The score at 6 months after surgery reached a level ranging from 4 to 23. The improvement in score ranged from -51% to -92%. GPi-DBS produced a marked effect even in patients who had previously undergone thalamotomy or pallidotomy. At 6 months after surgery, all patients were receiving bipolar stimulation with a wide interpolar distance, using contact 0 or 1 as the cathode and contact 2 or 3 as the anode. Stimulation was being performed at an intensity of around 2.0 V with a pulse width of 0.21 ms at a high frequency ranging from 120 to 140 Hz. GPi-DBS represents an important therapeutic option in many patients with primary generalized dystonia.

Adolescent↗
PubMed2003

Localization of thalamic cells with tremor-frequency activity in Parkinson's disease and essential tremor.

It has been reported that parkinsonian and essential tremor can be controlled by deep brain stimulation or radiofrequency lesion within the cluster of cells with a tremor-frequency activity in the ventral thalamic nuclei. However, there have been very few reports about the exact localization of cells with tremor-frequency activity in the ventral thalamic nuclei. In the present study, we investigated the localization of cells with tremor-frequency activity in the ventral thalamic nuclei employing autopower spectrum and coherence analysis. Activity of a total of 130 cells, 63 in patients with parkinsonian tremor and 67 in patients with essential tremor, were recorded from the area anterior to the nucleus ventralis caudalis. Among these cells, 31 cells showed a coherence of greater than 0.4 to the electromyographic activity of both agonist and antagonist muscles. The proportion of cells exhibiting tremor-frequency activity were 26.8% in the nucleus ventralis intermedius (Vim) and 25.0% in the nuclei ventralis oralis posterior et anterior (Vop + Voa). There were no significant differences in proportion by nuclear location or disease. The present study demonstrated that cells with tremor-frequency activity are widely distributed over the area extending from the Vim to the Vop + Voa. This indicates that the best location for placing electrodes for deep brain stimulation or a radiofrequency lesion cannot be defined by identification of cells with tremor-frequency activity alone.

Action Potentials↗
PubMed2003

DBS therapy for a persistent vegetative state: ten years follow-up results.

Twenty-one cases of a persistent vegetative state (PVS) caused by various kinds of brain damage were evaluated neurologically and electrophysiologically at 3 months after the brain injury. The 21 cases were treated by deep brain stimulation (DBS) therapy, and followed up for over 10 years. The stimulation sites were the mesencephalic reticular formation (2 cases) and CM-pf complex (19 cases). Eight of the patients emerged from the PVS, and became able to obey verbal commands. However, they remained in a bedridden state. These 8 cases revealed a desynchronization on continuous EEG frequency analysis. The Vth wave of the ABR and N20 of the SEP could be recorded even with a prolonged latency, and the pain-related P250 was recorded with an amplitude of over 7 microV. The mean survival time of these 8 cases was 6.1 years, as compared to 3.1 years for the other 13 cases. Overall, 4 cases are alive after more than 10 years. DBS therapy may be useful for allowing patients to emerge from a PVS, if the candidates are selected according to neurophysiological criteria. The fact that 19% (4/21) of the PVS cases treated with DBS survived for over 10 years should be stressed in comparison with the usual survival period for the untreated PVS.

Adult↗
PubMed2003

The characteristics of the bacterial community structure and population dynamics for phosphorus removal in SBR activated sludge processes.

The characteristics of the bacterial community structure and population dynamics for phosphorus removal in activated sludge were investigated using laboratory-scale sequencing batch reactor (SBR) activated sludge processes fed with four different carbon sources. Phosphorus removal activity, quinone profile of the activated sludge and isolated bacterial strains were monitored. An enhanced phosphorus removal activity was accompanied by the increase in ubiquinone-9 (Q-9). The relationships between phosphorus removal activity and Q-9 contents of the isolated bacterial strains were dependent neither on the organic substrates nor on the species of isolated bacterial strains. The enhanced phosphorus removal capability of activated sludge seemed to be due to the increase in the populations of bacteria with activity of phosphorus removal, i.e. species succession of bacteria in activated sludge ecosystems, rather than the increase in the phosphorus removal capability of phosphorus removal bacteria. Not only Acinetobacter but also Pseudomonas identified from isolated strains were regarded as representative polyphosphates-accumulating organisms and predominant species to the whole of bacterial population in activated sludge for phosphorus removal.

Acinetobacter↗
PubMed2003

Extranodal lymphoblastic lymphoma of suspected B-cell lineage in the gingiva of a racehorse, accompanied by mandibular osteolysis.

A mass developed in the mandibular gingiva of a thoroughbred racehorse. When the horse could no longer eat unassisted, it was killed and immediately autopsied. Macroscopically, the mandible exhibited extensive osteolysis, with only a small amount of bone remaining around the tooth roots. The cut surface of the mass around the mandible consisted of neoplastic medullary tissue, in which osteogenesis was observed. The medullary tissue was composed of pleomorphic medium-sized to large cells, interlaced by collagen bundles. These cells had large, pale, round or ovoid, sometimes cleaved nuclei, with one or two prominent nucleoli. Mitoses were numerous. Electron microscopy showed that the cells in the medullary tissues were similar in shape to undifferentiated lymphocytes. Immunohistochemically, these cells were positive for B-cell associated antigen in the pre-B-cell stage. Our findings suggest that the horse had extranodal lymphoblastic lymphoma of suspected B-cell lineage, possibly originating from the lymphatic system of the gingiva. We consider that the osteolysis resulted from activation of osteoclasts by proliferation of the tumour cells.

Animals↗
PubMed2003

Population-based distribution of plasminogen activity and estimated prevalence and relevance to thrombotic diseases of plasminogen deficiency in the Japanese: the Suita Study.

Reduced plasminogen activity with a normal level of antigen is commonly observed in Japanese individuals. The first reported patient with plasminogen deficiency was accompanied with deep vein thrombosis. The present study examines whether heterozygous or homozygous deficiency of plasminogen is a risk factor for thrombotic disease. This study measures the plasminogen activity of 4517 individuals in the general population, determines the cut-off to define plasminogen deficiency, and identifies plasminogen deficiencies in the control groups and thrombotic disease groups. In another study, we examined the phenotypes of consecutive patients with homozygous plasminogen deficiency detected in our hospital. We found 173 and two of 4517 individuals to have heterozygous and homozygous deficiency with normal plasminogen antigen level, respectively, and 19 to have heterozygous deficiency with reduced antigen levels. The incidence of plasminogen deficiency in an age- and sex-matched control group (13/324, 4.01% for deep vein thrombosis or 13/330, 3.94% for stroke) selected from the 4517 individuals was not significantly different from those in patients with deep vein thrombosis (3/108, 2.78%) or cardioembolic stroke (6/110, 5.55%). Among 19 patients with homozygous plasminogen deficiency showing about 10% plasminogen activity, none had deep vein thrombosis. These findings indicate that neither heterozygous nor homozygous plasminogen deficiency constitutes a significant risk factor for thrombotic disease.

Aged↗
PubMed2003

[Left ventricular-right atrial communication detected by pregnancy; report of a operative case].

A 24-year-old pregnant female was admitted to our hospital because of congestive heart failure. When she was 3 month old, she underwent closure of patent ductus arteriosus. Echocardiography, cardiac catheterization and selective angiocardiography showed a left ventricular-right atrial shunt. At the operation, we found a left ventricular right-atrial communication (group I) and repaired the defect directly. The patient was discharged and returned to her social life.

Adult↗
PubMed2003

[Preoperative autologous blood donation in patients undergoing open heart surgery].

We examined the possibility to avoid the homologous blood transfusion in patients undergoing open heart surgery by predonation of 200 ml or 400 ml on the day before operation. Between March 1999 and December 2001, 117 patients underwent scheduled open heart surgery. In these patients, preoperatively collected autologous blood on the day before operation amounted 200 ml or 400 ml. We divided these patients into 3 groups according to the necessity of homologous blood, no transfusion (group A, n = 77), intraoperative transfusion (group B 1, n-29) and postoperative transfusion (group B 2, n = 11). In 65.8% of patients the homologous blood transfusion could be avoided. Preoperative, intraoperative and postoperative factors were compared in the 3 groups. Especially, old age, female, body weight and preoperative hemoglobin value were significantly different between 3 groups. Postoperative Svo2 and postoperative hemoglobin value were significantly different between 3 groups. The purpose of this study was to evaluate that the predonation of 200 ml or 400 ml on the day before operation may be to avoid the homologous blood transfusion and that preoperative, intraoperative and postoperative factors in regard to homologous blood transfusion.

Age Factors↗
PubMed2003

Start-up of full-scale anaerobic digesters treating municipal solid waste.

Raising organic loading rate, and the behavior of dissolved CODcr (D-CODcr), VFA and specific methanogen activity, were investigated through a laboratory experiment for the start-up of a sludge recycling center. Moreover, application for MPN-PCR methods using a gene as a direct technique to measure the quantity of methanogen was attempted. It was recognized that specific methanogen activity depends on the quantity of methanogen, and that gas production does not reflect the condition of methane fermentation. The methane fermentation condition was checked through the specific methanogen activity and analysis of D-CODcr. The target organic loading rate was reached in the short period of about 30 days, and rapid start-up was successfully attained for a full-scale anaerobic digester.

Bacteria, Anaerobic↗
PubMed2002

Size-selective extended X-ray absorption fine structure spectroscopy of free selenium clusters.

In a recent paper [M. Yao et al., J. Synchrotron Radiat. 8, 542 (2001)]], we proposed a new method for the size-selective EXAFS (extended x-ray absorption fine structure) of neutral-free clusters, in which not only the x-ray absorption process but also the deexcitation processes are utilized as the structural information. In order to verify this method experimentally, we have developed the synchronous measurements of EXAFS and photoelectron photoion coincidence and carried them out for a Se cluster beam by utilizing the third-generation intense x-ray source. The EXAFS spectra for Se small clusters have been obtained and compared critically with theoretical predictions.

Journal Article↗
PubMed2002

Expression of a gene for Mn-peroxidase from Coriolus versicolor in transgenic tobacco generates potential tools for phytoremediation.

In efforts aimed at the detoxification of contaminated areas, plants have many advantages over bacteria and fungi. We are attempting to enhance the environmental decontamination functions of plants by transferring relevant genes from microorganisms. When the gene for Mn-peroxidase (MnP) from Coriolus versicolor was expressed in transgenic tobacco plants, one line (designated fMnP21) expressed MnP activity at levels 54-fold higher than in control lines. When undamaged roots of transgenic plants were applied to liquid medium supplemented with 250 microM pentachlorophenol (PCP), the decrease in the level of PCP in fMnP21 (86% reduction) was about 2-fold higher than that in control lines (38% reduction). Expression of the gene for MnP in the transgenic plants had no obvious negative effects on their vegetative and sexual growth. Our system should contribute to the development of novel methods for the removal of hazardous chemicals from contaminated environments using transgenic plants.

Basidiomycota↗
PubMed2002

Deep brain stimulation therapy for a persistent vegetative state.

Twenty cases of a persistent vegetative state (PVS) caused by various kinds of brain damage were neurologically and electrophysiologically evaluated at 3 months after persistence of the PVS, and were treated by deep brain stimulation (DBS) therapy. The stimulation sites were the mesencephalic reticular formation (2 cases) and CM-pf complex (18 cases). Seven of the patients emerged from the PVS, and became able to obey verbal commands. However, they remained in a bedridden state. These 7 cases revealed a desynchronization or slight desynchronization pattern on continuous EEG frequency analysis. The Vth wave of ABR and N20 of SEP could be recorded even with a prolonged latency, and the pain-related P250 was recorded with an amplitude of over 7 microV. We conclude that chronic DBS therapy may be useful for allowing the patient to emerge from a PVS, if the candidates are selected according to the neurophysiological criteria. In view of the severely disabled state of the patients who emerged from the PVS, a special rehabilitation program which includes neurostimulation therapy may be necessary for treatment of the PVS.

Adult↗
PubMed2002

Control of post-stroke movement disorders using chronic motor cortex stimulation.

The effects of motor cortex (MC) stimulation on post-stroke movement disorders were analyzed in 50 patients. These individuals either underwent MC stimulation primarily for the purpose of controlling their post-stroke involuntary movements (n = 8) or underwent MC stimulation for the purpose of controlling their post-stroke central pain (n = 42). In the latter patients, the effects of MC stimulation on co-existent involuntary or voluntary movement disorders were analyzed retrospectively. Good control of involuntary movements was observed in 2 of 3 patients with hemichoreo-athetosis, 2 of 2 patients with distal resting or action tremor, and 1 of 3 patients with proximal postural tremor. Subjective improvements in motor performance were reported by 8 patients who had mild motor weakness, and the effects appeared to be attributable to attenuation of rigidity. We consider that these findings justify further clinical studies on MC stimulation for the control of post-stroke movement disorders.

Electric Stimulation Therapy↗
PubMed2002

Mechanisms of the mass effect of cerebral contusion: ICP monitoring and diffusion MRI study.

OBJECTIVE: Cerebral contusion is sometimes associated with a non-hemorrhagic mass effect which progresses rapidly within 12-48 hours post-trauma. In order to determine the mechanisms underlying such a mass effect, we analyzed data obtained from ICP monitoring and diffusion MRI in a total of 38 patients with cerebral contusion. METHODS: Diffusion imaging and ADC mapping were performed employing 1.5 T echo planar MRI. ADC values were expressed as a ratio relative to the values of intact brain areas. RESULTS: In 6 patients, ICP became uncontrollable medically and surgical resection of the contused brain tissue was eventually performed. Within 24 hours post-trauma, diffusion images revealed a low intensity core and a high intensity rim in the contusion. The ADC ratio increased in the central area (1.13 +/- 0.21) and decreased in the peripheral area (0.67 +/- 0.14). A crescent-shaped zone of very high ADC ratio (1.45 +/- 0.14) was observed at the border between these two areas during the period of 24-48 hours. CONCLUSIONS: It appears that the capacitance of edema fluid accumulation is elevated by cellular disintegration in the central area, whereas the resistance to edema fluid propagation is elevated by cellular swelling in the peripheral area. We suggest that such events facilitate extracellular edema fluid accumulation within contused brain tissue and contribute, together with cellular swelling itself, to the non-hemorrhagic mass effect of cerebral contusion.

Brain Concussion↗
PubMed2002

Western blotting analysis of the beta-hexosaminidase alpha- and beta-subunits in cultured fibroblasts from cases of various forms of GM2 gangliosidosis.

OBJECTIVES: The GM2 gangliosidoses are a group of genetic disorders caused by the accumulation of ganglioside GM2 in neuronal cells. We examined the alpha- and beta-subunits of beta-hexosaminidases by a non-radioisotopes detecting system to evaluate whether it was a useful method for understanding of the pathophysiologies of GM2 gangliosidoses. MATERIALS AND METHODS: We investigated the alpha- and beta-subunits of beta-hexosaminidases in cultured fibroblasts from cases of various forms of GM2 gangliosidosis by means of Western blotting and a chemiluminescence detection system. RESULTS: In a patient with infantile Tay-Sachs disease [HEXA genotype, Int5-SA(g-1-->t)/Int5-SA(g-1-->t)], the mature alpha-subunit was undetectable. In a patient with infantile Sandhoff disease (HEXB genotype, C534Y/C534Y), the mature beta-subunit was deficient. However, a small amount of the mature beta-subunit was detected in a patient with adult Sandhoff disease (HEXB genotype, R505Q(+I207V)/R505Q(+I207V)), which may have resulted in the residual enzyme activity and mild clinical course. Normal amounts of alpha- and beta-subunits were detected in a patient with GM2 activator deficiency. CONCLUSION: This method is easy and sensitive for detecting target proteins, and is useful for clarification of the pathophysiologies of GM2 gangliosidoses.

Adult↗