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Biomedical subjects

K Kochi

Publications and source records attributed to K Kochi.

At least 19 recordsLinked to original sources
PubMed1998

Global, regional, and local measures of complexity of multichannel electroencephalography in acute, neuroleptic-naive, first-break schizophrenics.

BACKGROUND: Schizophrenic symptoms commonly are felt to indicate a loosened coordination, i.e. a decreased connectivity of brain processes. METHODS: To address this hypothesis directly, global and regional multichannel electroencephalographic (EEG) complexities (omega complexity and dimensional complexity) and single channel EEG dimensional complexities were calculated from 19-channel EEG data from 9 neuroleptic-naive, first-break, acute schizophrenics and 9 age- and sex-matched controls. Twenty artifact-free 2 second EEG epochs during resting with closed eyes were analyzed (2-30 Hz bandpass, average reference for global and regional complexities, local EEG gradient time series for single channels). RESULTS: Anterior regional Omega-Complexity was significantly increased in schizophrenics compared with controls (p < 0.001) and anterior regional Dimensional Complexity showed a trend for increase. Single channel Dimensional Complexity of local gradient waveshapes was prominently increased in the schizophrenics at the right precentral location (p = 0.003). CONCLUSIONS: The results indicate a loosened cooperativity or coordination (vice versa: an increased independence) of the active brain processes in the anterior brain regions of the schizophrenics.

Acute Disease↗
PubMed1998

[Aortic regurgitation caused by the proximal dissecting flap invagination to the left ventricle].

A 68-year-old male with sudden back pain and cardiogenic shock status transferred to our ward. Transthoracic echocardiography revealed that the abnormal round shape string was in the left ventricular outflow tract. The continuity from the staring to the aortic valve was unclear. Intimal flap could not be detected at the level of the ascending aorta. Color Doppler flow imaging showed that the severe AR jet extended into the round string. TEE showed that the intimal tear and flap was seen just above the left subclavian artery. Preoperative diagnosis was acute Stanford type A dissection and acute severe AR due to the inversion of the proximal intimal flap to the left ventricular outflow tract through the aortic valve. At operation, the proximal intimal flap was dissected circumferentially and was cut all the way around 8 cm above the aortic valve ring and was inverted to the left ventricular outflow tract. The aortic valve was preserved because of its normal character after exclusion of the proximal intimal flap. Ascending and arch replacement was carried out. Postoperative TEE and TTE slowed no findings of AR. The patient's postoperative course was uneventful. To our knowledge, this is the first reported case that severe AR caused by the proximal intimal invagination to the left ventricle.

Acute Disease↗
PubMed1998

Smell and taste of chewing gum affect frequency domain EEG source localizations.

We investigated brain electric field signatures of subjective feelings after chewing regular gum or gum base without flavor. 19-channel eyes-closed EEG from 20 healthy males before and after 5 minutes of chewing the two gum types in random sequence was source modeled in the frequency domain using the FFT-Dipole-Approximation. 3-dimensional brain locations and strengths (Global Field Power, GFP) of the equivalent sources of five frequency bands were computed as changes from pre-chewing baseline. Gum types differed (ANOVA) in pre-post changes of source locations for the alpha-2 band (to anterior and right after regular gum, opposite after gum base) and beta-2 band (to anterior and inferior after regular gum, opposite after gum base), and of GFP for delta-theta, alpha-2 and beta-1 (regular gum: increase. gum base: decrease). Subjective feeling changed to more positive values after regular gum than gum base (ANOVA).--Thus, chewing gum with and without taste-smell activates different brain neuronal populations.

Adult↗
PubMed1997

Multichannel EEG fields during and without visual input: frequency domain model source locations and dimensional complexities.

27-Channel EEG potential map series were recorded from 12 normals with closed and open eyes. Intracerebral dipole model source locations in the frequency domain were computed. Eye opening (visual input) caused centralization (convergence and elevation) of the source locations of the seven frequency bands, indicative of generalized activity; especially, there was clear anteriorization of alpha-2 (10.5-12 Hz) and beta-2 (18.5-21 Hz) sources (alpha-2 also to the left). Complexity of the map series' trajectories in state space (assessed by Global Dimensional Complexity and Global OMEGA Complexity) increased significantly with eye opening, indicative of more independent, parallel, active processes. Contrary to PET and fMRI, these results suggest that brain activity is more distributed and independent during visual input than after eye closing (when it is more localized and more posterior).

Adult↗
PubMed1997

Prestimulus EEG microstates influence visual event-related potential microstates in field maps with 47 channels.

The influence of the immediate prestimulus EEG microstate (sub-second epoch of stable topography/map landscape) on the map landscape of visually evoked 47-channel event-related potential (ERP) microstates was examined using the frequent, non-target stimuli of a cognitive paradigm (12 volunteers). For the two frequent prestimulus microstate classes (oriented left anterior-right posterior and right anterior-left posterior), ERP map series were selectively averaged. The post-stimulus ERP grand average map series was segmented into microstates; 10 were found. The centroid locations of positive and negative map areas extracted as landscape descriptors. Significant differences (MANOVAs and t-tests) between the two prestimulus classes were found in four of the ten ERP microstates. The relative orientation of the two ERP microstate classes was the same as prestimulus in some ERP microstates, but reversed in others. Thus, brain electric microstates at stimulus arrival influence the landscapes of the post-stimulus ERP maps and therefore, information processing; prestimulus microstate effects differed for different post-stimulus ERP microstates.

Adult↗
PubMed1997

Chewing-gum flavor affects measures of global complexity of multichannel EEG.

Global complexity of spontaneous brain electric activity was studied before and after chewing gum without flavor and with 2 different flavors. One-minute, 19-channel, eyes-closed electroencephalograms (EEG) were recorded from 20 healthy males before and after using 3 types of chewing gum: regular gum containing sugar and aromatic additives, gum containing 200 mg theanine (a constituent of Japanese green tea), and gum base (no sugar, no aromatic additives); each was chewed for 5 min in randomized sequence. Brain electric activity was assessed through Global Omega (Omega)-Complexity and Global Dimensional Complexity (GDC), quantitative measures of complexity of the trajectory of EEG map series in state space; their differences from pre-chewing data were compared across gum-chewing conditions. Friedman Anova (p < 0.043) showed that effects on Omega-Complexity differed significantly between conditions and differences were maximal between gum base and theanine gum. No differences were found using GDC. Global Omega-Complexity appears to be a sensitive measure for subtle, central effects of chewing gum with and without flavor.

Adult↗
PubMed1997

[A case of extracardiac noncoronary sinus Valsalva aneurysm associated with aortic regugitation].

A case of extracardiac noncoronary sinus Valsalva aneurysm was reported. A 11-year-old male with history of mild AR was admitted to the hospital due to severe AR. Echocardiography revealed that the severe AR and an aneurysm in the posterior part of the ascending aorta. Angiography revealed that the origin of the aneurysm was noncoronary sinus. Operative findings showed that the aneurysm sized 23 mm by 25 mm was an extracardiac type which grew posteroinferiorily at the left side of noncoronary sinus and that the dilation. Neither aortic valve nor the aortic route showed degenerative change. The ptosis of the valvular ring due to aneurysmal dilation of the noncoronary sinus caused AR. Then, valve repair composed by commissuroplasty and commissural suspension was carried out. And intraluminal patch closure technique in which the longitudinal diameter of patch was half of that of the aneurysm was effective on suspension of the valvular ring. Postoperative echocardiography showed decreasing of AR.

Aortic Aneurysm↗
PubMed1997

[Serratia marcescens prosthetic mitral valve endocarditis associated with hemolytic anemia].

A 57-year-old female who had been performed mitral valve replacement (MVR) using 31 mm prosthetic valve 32 months before entered the hospital for the evaluation of long standing severe hemolytic anemia without infectious sign. Transesophageal echocardiogram revealed a moderate sized vegetation on the atrial site of the prosthetic valve. The size and number of the vegetation were increased after deterioration of infectious illness. Blood culture grew serratia marcessans and alpha-hemolytic Streptococcus. Re-MVR was carried out with the diagnosis of prosthetic valve endocarditis (PVE). As the symptom of PVE, hemolytic anemia without infectious sign is a rare condition. TEE is an useful method to make diagnosis of PVE by detecting the vegetations and evaluating their change of size and methods and to evaluate the effectiveness of the treatment.

Anemia, Hemolytic↗
PubMed1996

Event-related potential P300 microstate topography during visual one- and two-dimensional tasks in chronic schizophrenics.

Reports on left-lateralized abnormalities of component P300 of event-related brain potentials (ERP) in schizophrenics typically did not vary task difficulties. We collected 16-channel ERP in 13 chronic, medicated schizophrenics (25 +/- 4.9 years) and 13 matched controls in a visual P300 paradigm with targets defined by one or two stimulus dimensions (C1: color; C2: color and tilt); subjects key-pressed to targets. The mean target-ERP map landscapes were assessed numerically by the locations of the positive and negative map-area centroids. The centroids time-space trajectories were searched for the P300 microstate landscape defined by the positive centroid posterior of the negative centroid. At P300 microstate centre latencies in C1, patients' maps tended to a right shift of the positive centroid (p < 0.10); in C2 the anterior centroid was more posterior (p < 0.07) and the posterior (positive) centroid more anterior (p < 0.03), but without left-right difference. Duration of P300 microstate in C2 was shorter in patients (232 vs 347 ms; p < 0.03) and the latency of maximal strength of P300 microstate increased significantly in patients (C1: 459 vs 376 ms; C2: 585 vs 525 ms). In summary only the one-dimensional task C1 supported left-sided abnormalities; the two-dimensional task C2 produced abnormal P300 microstate map landscapes in schizophrenics, but no abnormal lateralization. Thus, information processing involved clearly aberrant neural populations in schizophrenics, different when processing one and two stimulus dimensions. The lack of lateralization in the two-dimensional task supported the view that left-temporal abnormality in schizophrenics is only one of several task-dependent aberrations.

Adolescent↗
PubMed1996

[Surgical treatment for subacute left ventricular free wall rupture complicating acute myocardial infarction--pericardial patch gluing method].

We reviewed 22 cases with surgical repair for subacute left ventricular free wall rupture complicating acute myocardial infarction. Different operative technique was used. Direct closure or patch repair with infarctectomy was preformed in first patients with a great difficulty in hemostasis. Since 1988 we sutured a large pericardial patch covering the infarcted myocardium under extra corporeal circulation in 11 patients (pericardial patch suture technique). From 1993 we began to glue a pericardial patch with Aron alpha without cardiopulmonary bypass (pericardial patch gluing technique). There were eight early death and four late death. Most common cause of death was low cardiac output syndrome (LOS). With medical therapy 13 patients in cardiogenic shock improved before surgery and only three developed postoperative LOS, but all six patients with sustained shock developed LOS without survivor (p = 0.007). Two of the five patients underwent direct closure or infarctectomy and seven of the 11 employed pericardial patch suture technique developed LOS, but none of the six used pericardial patch gluing technique developed LOS. Medical treatment such as intraaortic balloon pumping, catecholamine and subxyphoid drainage in order to improve hemodynamic condition before surgery is extremely important. Pericardial patch gluing technique seems to be useful since cardiac function would be maximally preserved.

Aged↗
PubMed1995

A case of isolated acute DeBakey II redissection occurring in a postoperative survivor who underwent an arch replacement for acute DeBakey IIIb dissection.

A case of isolated acute DeBakey II redissection which occurred in a postoperative survivor who underwent an arch replacement for acute DeBakey IIIb dissection is reported. The operative findings revealed that there was an intimal tear above the left coronary cusp, that there was a false lumen in the native ascending aorta, and that a residual false lumen caused by the initial operation had not been detected. Redissection caused mainly by the operative procedure, such as the failure to include the site of the intimal tear in the original repair and the formation of a new dissection as a result of anastomotic failure, is frequently seen. However, isolated redissection is a rare condition. In this paper we discuss classification, diagnosis and treatment of redissection.

Aortic Dissection↗
PubMed1995

A case of traumatic pseudoaneurysm of the ascending aorta occurring in a postoperative patient who underwent arch replacement and Bentall's operation.

A case of traumatic pseudoaneurysm of the ascending aorta occurring in a postoperative patient who underwent an arch replacement and Bentall's operation was reported. A bleeding point was clear at the graft of the ascending aorta, and a pseudoaneurysmal formation was suspected following an echocardiogram. An aortogram demonstrated the presence of an aneurysm approximately 8 cm by 4 cm in size originating 5 cm above the right coronary ostia. An emergency operation was carried out. A Trans-femoral bypass was established before sternotomy. The Operative findings showed that adhesive connective tissue covered a pseudoaneurysm 8 cm by 4 cm in size, and that there was a tear in the anastomosis of the grafts between the ascending aorta and the arch 5 cm above the coronary ostia. Direct suture was performed, using hypothermic circulatory arrest. In this paper, We discuss the mechanism, classification, and operative strategy of traumatic pseudoaneurysm.

Adult↗
PubMed1994

An experience of ischemic limb salvage associated with myositis ossificans of the left thigh.

A case of ischemic limb salvage associated with myositis ossificans of the left thigh in a 66-year-old man was reported. The patient had a medical history of cerebral palsy and a cervical spinal cord injury, and had an operative past history of hip arthroplasty for fracture of the left femoral neck 10 years before. He showed ischemic symptoms such as paleness, coldness, and loss of the left dorsal arterial pulsation in the left toe, and had a rapidly growing mass in the left thigh. Roentgenography and computed tomography showed a mass 10 cm by 10 cm by 8 cm in size with severe calcification in the left quariceps muscle. Occlusion of the left common femoral artery was found in the arteriogram. Surgery was carried out in order to establish an accurate diagnosis and to rescue the left lower limb. The arterial pulsation was recovered as the result of completely resecting the left quariceps muscle tumor. The pathohistological diagnosis was of myositis ossificans in the quariceps muscle of the thigh. Etidronate disodium was administered in order to prevent a recurrence postoperatively. The patient has been well for the 13 months since surgery.

Aged↗
PubMed1993

A case report of substernal goiter.

A case of substernal goiter is reported. A 78-year-old female was admitted to our hospital with no symptoms. Chest roentgenography on admission showed that a mass of 3 by 5 cm in size with calcification located in the substernal region. Computed tomography of the chest and aortography revealed that the mass was attached to the trachea, but the connection to the great vessels was not clear. Pathological findings of the incisional biopsy specimen showed thyroid tissue with no evidence of malignancy. Our clinical diagnosis was substernal goiter. Surgery was not carried out in this case, based on the literature. Surgery is indicated in case of malignancy or in cases with severe illness such as respiratory disorder and superior vena cava syndrome.

Aged↗
PubMed1993

A case report of epithelioid leiomyosarcoma of transverse mesocolon: diagnosis and treatment.

A case of epithelioid leiomyosarcoma of the transverse mesocolon in a 45-year-old man was reported. The patient had a rapidly growing mass in the left upper quadrant. Ultrasonography, gastrointestinography, and abdominal computed tomography showed that the mass was separated from the pancreas, the gastrointestinal tract, and the retroperitoneal organs. Preoperatively the primary origin of this tumor was related to the transverse mesocolon. On laparotomy the tumor of 5cm by 6cm by 3cm in size was found in the anterior left of the transverse mesocolon and the mass was resected entirely. The patient is well 18 months after surgical treatment with no evidence of recurrence.

Humans↗