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Biomedical subjects

K Shimazu

Publications and source records attributed to K Shimazu.

At least 37 records · Page 2Linked to original sources
PubMed1999

Retinal ganglion cell response properties in the transcorneal electrically evoked response of the visual system.

To identify the retinal origin of a cortical evoked potential elicited by transcorneal electrical stimulation of the visual system (EER), the response properties of retinal ganglion cells (RGCs) of cats to transcorneal electrical stimuli were studied. The discharge latency of RGCs to transcorneal stimulation had two peaks with a high temporal resolution. The latency of early components of the EER is associated with the discharge latency of RGCs. Some RGCs showed prominent oscillatory discharges after transcorneal stimulation. Discharges of ON-bipolar cells responding to transcorneal stimulation were significantly inhibited by intravitreal injection of DL-2-amino-4-phosphonobutyrate (APB), which blocks the ON-pathway. These findings indicate that the EER has far-field potentials that might relate to oscillatory discharges of RGCs, and that ON bipolar cells and their related synaptic sites are involved in transcorneal electrical stimuli. The far-field potentials of the EER may have clinical applications, similar to those of somatosensoric evoked potentials and auditory brain stem potentials.

Aminobutyrates↗
PubMed1999

Neuronal origin of the transcorneal electrically evoked response in area 17 (primary visual cortex) of cats.

We investigated how the neuronal activity of the cells in area 17 of cats evoked by transcorneal electrical stimuli is associated with the transcorneal electrically evoked response (EER). Neuronal firings were associated with the negative components of the EER, N1 (9 ms latency) and N2 (20 ms latency). Excitation of a longer latency was suppressed and periodic firings were rarely found. These findings indicate that the early negative components of the EER consist of the synaptic activities over the discharge thresholds of cortical cells, and also suggest that inhibition in the visual cortex may affect the EER.

Animals↗
PubMed1999

[Clinical study of 8 patients with round atelectasis associated with asbestos exposure].

Matsubase town (where our hospital is located) has a history of environmental exposure to asbestos. We reviewed the clinical and radiological features of 8 patients with round atelectasis associated with asbestos exposure who had been examined at our hospital between 1988 and 1997. The subjects were followed up over a period ranging from 6 months to 10 years (mean: 54 months). Round tumors were detected in 6 of the patients by chest CT scans but not by chest X-ray films. Five of those patients underwent transbronchial lung biopsies, and 1 was examined by bronchography. Two patients had a history of pleural effusion. Seven of the patients exhibited round atelectasis in their lower lung fields. The clinical course of round atelectasis was unchanged in all patients. Although round atelectasis is sometimes suspected of being bronchial carcinoma, it can be diagnosed without thoracotomy, on the basis of the patient's medical history and a careful examination of radiological findings.

Aged↗
PubMed1999

[A study of beta-lactamase activity of mycobacteria and clinical trial of penicillin/beta-lactamase inhibitor combinations in the treatment of drug-resistant Mycobacterium tuberculosis].

Beta-lactamase activity was determined using a nitrocefin disc method on 34 Mycobacterium tuberculosis (M. tuberculosis) strains and 13 nontuberculous mycobacteria strains. In the 34 M. tuberculosis strains, 23 strains showed beta-lactamase activity. In 10 Mycobacterium avium complex strains, no beta-lactamase activity was detected. In the Mycobacterium chelonae strains, all three strains examined showed strong beta-lactamase activity. No correlation was found between beta-lactamase activity and resistance to anti-tuberculous chemotherapeutic agents. Four patients who were persistently positive for multi-drug-resistant M. tuberculosis (MDR-TB) on sputum and positive in beta-lactamase activity, were treated with penicillin/beta-lactamase inhibitor combinations. In two cases, the trials were discontinued because of diarrhea; the trials were continued in the remaining two for four months, but the MDR-TB was positive during the course of the therapy. Effectiveness of the therapy with penicillin/beta-lactamase inhibitor combinations against M. tuberculosis was obscure, although many of M. tuberculosis examined showed beta-lactamase activity.

Amoxicillin↗
PubMed1999

[A case of Creutzfeldt-Jakob disease exhibiting athetosis in the early stage].

A 68-year-old man was hospitalized on 24 June, 1998 because of visual and gait disturbance. A month before admission, he had been aware of blurred or double vision while watching TV. A few days later, he developed dysphagia and clumsiness in the fingers. His gait became unstable and he exhibited restless finger movements. His shoulders and trunk showed torsion while walking. On admission, he became disoriented and showed rigidity in the legs and athetosis in the bilateral fingers. Routine laboratory findings, thyroid function data, and the serum levels of vitamin B1, B12, Cu, and ceruloplasmin were within the normal ranges. Periodic synchronous discharges (PSD) were observed on electroencephalography. MRI showed T2-high intensity and atrophy of the bilateral caudate nucleus and putamen in addition to the cerebral cortex. 99mTc-ECD-SPECT showed a decrease of local blood flow in the bilateral frontal, right temporal, and bilateral parietal lobes and bilateral thalami. Athetosis became exacerbated and was observed for a month, overlapping with myoclonus. We diagnosed the patient as having CJD because of progressive dementia, myoclonus and PSD. Analysis of the prion protein revealed that codon 129 was Met/Met and codon 219 Glu/Glu by DNA sequences. The patient developed akinetic mutism and rigid contracture, and died of pneumonia on 5 September, 1998. Because athetosis is thought to involve the bilateral caudate nucleus, putamen and thalamus, the findings of diagnostic imaging in this patient might be relative to the clinical symptoms.

Aged↗
PubMed1998

Comparative study of efficacy of plasma exchange versus intravenous gammaglobulin treatment on acute postinfectious polyradiculoneuropathy: a preliminary report.

We tried to compare the efficacy of plasma exchange (PE) with that of intravenous immunoglobulin (IVIG) in patients with postinfectious polyneuritis (Guillain-Barré syndrome [GBS] and cranial neuritis). Fifteen patients with postinfectious polyneuritis were divided into 2 groups. The IVIG group included 5 cases of GBS and 2 cases of postinfectious cranial neuritis (ophthalmoplegic type). The PE group included 5 cases of GBS and 3 cases of postinfectious cranial neuritis (ophthalmoplegic type). The changes and incidences of improvement of muscle strength scores (MSSs) and ocular movement scores (OMSs) were evaluated before treatment and 1, 2, 3, and 4 weeks after treatment. No significant differences between the IVIG and PE groups were found in the MSSs or OMSs at any time after treatment. These data suggested that PE and IVIG had equivalent efficacy. In the IVIG group, the proportion of suppressor-inducer T cells significantly increased (p < 0.01) (before versus after treatment), and the proportion of suppressor-effector cells also increased but not significantly (before versus after treatment). In the PE group, the percentage of suppressor-inducer T cells significantly decreased (p < 0.05) (before versus after treatment) while the proportion of suppressor/cytotoxic T cells significantly increased (p < 0.05) (before versus after treatment). The percentage of suppressor-effector T cells also increased (before versus after treatment) but not significantly.

Acute Disease↗
PubMed1998

[A case of Kartagener's syndrome associated with pulmonary tuberculosis, pneumothorax and pulmonary aspergilloma].

A case of Kartagener's syndrome associated with multiple pulmonary complication was presented. A 19-year-old man was admitted to our hospital because of pulmonary tuberculosis in May 1972. He had been diagnosed as Kartagener's syndrome because of the presence of chronic parasinusitis, bronchiectasis and complete situs inversus. His chest radiographs in Dec 1972 revealed left pneumothorax. Chest radiographs in Aug 1975 appeared aspergilloma in the right middle lung field. He was administrated intravenous and oral anti-fungal agent and transbronchial installation of Amphotericin-B because of hemoptysis. Chest radiographs in July 1980 resolved the aspergilloma and his symptom were also resolved. In 1996, he had no pulmonary symptoms and respiratory failure. We consider that the Kartagener's syndrome was good prognosis with adequate pulmonary therapy.

Adult↗
PubMed1998

Color-coded Doppler imaging of subclavian steal syndrome.

We examined the usefulness of color-coded Doppler echography for evaluating hemodynamics in patients with subclavian steal syndrome. Eighteen patients with subclavian steal syndrome, aged 54 to 77 years, were investigated. The diagnosis was confirmed by conventional angiography and pulsed-wave Doppler sonography. Using color-coded Doppler echography, the common, internal and external carotid and vertebral arteries and the subclavian artery on the affected side were visualized. In all patients, color-coded images of the antegrade common carotid arterial flow and the retrograde vertebral arterial flow on the affected side were obtained. Rapid flow through stenotic lesions and reflux from vertebral to subclavian arteries at the vertebral arterial ostia were observed. Color-coded Doppler echography is superior to duplex echography without the color-coded mode, because the flow through the affected vertebral and subclavian arteries can be easily traced in detail and the images are persuasive. This method is beneficial for diagnosing subclavian steal syndrome.

Aged↗
PubMed1998

Rounded atelectasis that disappeared after bronchoscopy.

We describe a 70-year-old man who presented with a round opacity that disappeared after bronchoscopy. Chest computed tomograms (CT) showed a round opacity in the left lower posterior lung field. Brushings and washings of the left B10 through bronchoscope yielded neither malignant cells nor acid fast bacilli. The patient was diagnosed as having a benign tumor and was not medicated. Chest CT 1.5 months after bronchoscopy showed that the round opacity had disappeared. Although this course was unusual, this radiopacity was quite typical of round atelectasis on the basis of CT appearance.

Aged↗
PubMed1998

[Polymyalgia rheumatica and myelitis associated with anti-cardiolipin antibody].

A 78-year-old woman was admitted to our hospital on September 14, 1992, because of systemic myalgia and stiffness, joint pain, and gait disturbance. She had begun to feel headache and pain in the neck and shoulder in the middle of August, 1992. The pain became systemic, and was accompanied by a low-grade fever, which was unresponsive to NSAIDs. On admission, she had no joint swelling or deformities in the extremities. Neurological examination revealed weakness in the right leg, hypoalgesia below the left C4 level, hyperreflexia in the right extremities, and right Babinski's sign. The erythrocyte sedimentation rate was very high (100 mm/h). Levels of other acute phase reactants were also high. Tests for antinuclear antibody and anti-cardiolipin antibody were positive, but a test for rheumatoid factor was negative. Creatine kinase activity was within normal limits. A T1-weighted magnetic resonance image of the cervical spine at 0.5 T showed an intramedullary low signal. A T2-weighted image showed a borderless spindle-like high signal. Four nodules enhanced by Gd DTPA were seen at C1-C4. The age at onset, myalgia, stiffness, and erythrocyte sedimentation rate were considered to be consistent with a diagnosis of polymyalgia rheumatica. Glucocorticoid treatment was therefore started, and a dramatic clinical improvement was evident within a few days. The patient was discharged from hospital on November 30, 1992. To our knowledge, myelopathy complicated by polymyalgia rheumatica has never been reported previously. Recently, some patients with polymyalgia rheumatica have been reported to have anti-cardiolipin antibody in serum. In the present case anti-cardiolipin antibody may have played a role in the formation of microemboli or in angitis of the cervical spine.

Aged↗
PubMed1998

Anthophyllite exposure and endemic pleural plaques in Kumamoto, Japan.

OBJECTIVES: This study explored the high prevalence of pleural plaques in the town of Matsubase in Kumamoto, Japan. METHODS: Small-size chest X-ray film was used for screening, and all persons with pleural plaques were confirmed by computed tomography (CT). The prevalence rate of pleural plaques in the 4 districts of Matsubase and its surrounding towns and cities were also examined. The age-adjusted mortality rate for lung cancer in this town was compared with that of its surrounding towns and cities. RESULTS: Pleural plaques were found in 1357 persons (724 men and 633 women) among the inhabitants who were more than 20 years of age in Matsubase between 1988 and 1993. CT scans ascertained 938 cases with pleural plaques among the 11 14 persons who participated. Thus at least 9.5% of the inhabitants over 20 years of age in this town had pleural plaques. The neighboring towns had a higher rate than the more distant towns. A large-scale open-cast asbestos mine and mill had been in operation in Matsubase between 1883 and 1970. Mineral analysis revealed anthophyllite fibers. Most of the plaques were found in persons who had never worked in the mine or mill. CONCLUSIONS: The high prevalence of pleural plaques in Matsubase was due to anthophyllite exposure, mainly environmental. No mesotheliomas were found, however. These findings agree with those from an earlier study from Finland.

Adult↗
PubMed1998

[Clinical efficacy of sulbactam/ampicillin in comparison with cefotiam in the treatment of elderly patients with pneumonia].

Clinical efficacy and safety of pareteral sulbactam/ampicillin (SBT/ABPC) was compared with cefotiam (CTM) in a randomized clinical trial of pneumonia in the elderly at 13 National Hospitals of Kyushu island. 37 patients received SBT/ABPC 3 g i.v., b.i.d., and 31 patients received CTM 1 g i.v., b.i.d. for 7 to 14 days. 1. 68 patients (37 for SBT/ABPC and 31 for CTM) were evaluated for safety. No statistical differences were noted in the patients' backgrounds of either group. 2. The clinical efficacy of SBT/ABPC was 96.3% (26/27 cases) while CTM was 75.2% (17/23 cases). This was found to be statistically significant (Fisher's exact test: p < 0.05). 3. 100% of evaluated cases (10 for SBT/ABPC and 4 for CTM) showed bacterial elimination. 4. No side effects were observed in the study. 5. Abnormal laboratory findings were noted in 10.8% (4/37 cases) for SBT/ABPC and 3.2% (1/31 cases) for CTM. The major adverse events were mild elevation of GOT, GPT and A1-P for SBT/ABPC, and mild platelets overproduction for CTM. No statistical differences were noted in both groups. These results are consistent with SBT/ABPC as a highly effective antibiotic in the treatment of elderly patients with pneumonia.

Aged↗
PubMed1998

[A clinical study on the background of patients with nontuberculous pulmonary mycobacteriosis--predisposing factor and environment].

We studied the background of 78 patients with pulmonary nontuberculous mycobacteriosis from 1992 to 1996, and 56 patients (71.8%) were diagnosed as primary infection type and 22 patients (28.2%) as secondary infection type. The former consisted of 17 males and 39 females (mean age +/- SD; 67.4 +/- 12.9 years), and the latter consisted of 13 males and 9 females (mean age +/- SD; 74.0 +/- 7.5 years). Out of all 83 strains, 67 strains (80.7%) were M. avium complex, and out of 36 strains identified either M. avium or M. intracellulare, 34 strains (94.4%) were M. intracellulare and 2 strains (5.6%) were M. avium. Many patients lived in farming areas along the coast, and 35 patients (62.5%) of primary infection type and 11 patients (50%) of secondary infection type were or used to be farmers. Nine patients (16.1%) of primary infection type and 6 patients (27.3%) of secondary infection type had history of gastroduodenal ulcer, while only 3 of all 78 patients had sinusitis. There was a married couple who lived in a same house and 2 sisters who lived apart who were proved to have primary infection type but cross infection was not demonstrated in either case. The development of this disease seems to be related to a genetic susceptibility and environmental factors.

Adult↗
PubMed1998

[A case of secondary invasive pulmonary aspergillosis originating from an aspergilloma, successfully treated with itraconazole].

A 65-year-old man was admitted to our division with of productive cough and hemosputum. Chest radiographs and chest CT on admission showed old inflammatory shadows in both upper lung fields and a fungus ball in the left upper lung field. Despite antibiotic treatment, the patient's sputum volume increased and Aspergillus niger was repeatedly cultured from his sputum. Chest radiographs showed deterioration around the intracavitary fungus ball and a test for serum aspergillus antigen was positive. Secondary invasive pulmonary aspergillosis originating from aspergilloma was diagnosed based on his clinical symptoms, radiographic features and laboratory data. Administration of fluconazole failed to improve his clinical course and amphotericin B was discontinued because of hypokalemia. Oral administration of itraconazole was a successful treatment.

Aged↗
PubMed1998

[A round atelectasis that development 7 years after the start of follow-up].

A 60-year-old man was admitted to the hospital because of dyspnea on exertion in November 1990. He had a history of asbestos exposure and chest CT scans showed bilateral pleural thickening with calcification and oval-shaped consolidation in the right lower posterior lung field. A chest CT scan obtained in May 1994 showed that the shadow had become smaller and more round. Its size continued to decrease, and in June 1997 the "comet-tail sign" was observed. This is the longest interval between initiating of follow-up and development of round atelectasis yet reported.

Diagnosis, Differential↗
PubMed1998

[Hypouricemia in patients with meningitis].

Serum urate and sodium concentrations were measured in 23 patients with acute viral and bacterial meningitis. Serum urate level was 3.0 +/- 0.2 mg/dl (mean +/- S.D.) (3.6 +/- 1.2 mg/dl in male and 2.5 +/- 0.9 mg /dl in female) on admission, but gradually elevated with improvements of meningitis. It turned to 4.8 +/- 0.2 mg/dl after recovery, and the value on admission was significantly lower than that after recovery (p < 0.0001). Serum sodium level was 137.6 +/- 2.9 mEq/l on admission and 139.7 +/- 2.7 mEq/l after recovery; also lower in the former (p < 0.01). These results show that patients develop transient hypouricemia, which may be explained by SIADH (syndrome of inappropriate secretion of ADH), although SIADH is subclinical in most cases of meningitis.

Adult↗
PubMed1997

[The effects of vasoconstrictors on distribution of ischemic tissue flow in isolated perfused rat liver].

We studied the effects of ATP and epinephrine on distribution of ischemic hepatic tissue flow in the isolated perfused rat liver. Five minutes after clamping both the portal vein and hepatic artery, perfusion was started. Lidocaine was infused into the portal vein, and the concentration of lidocaine in hepatic outflow was measured with FPIA. The oxygen extraction ratio was also measured. Tissue surface blood flow was measured with laser-Doppler flowmetry. We measured the tissue flow at 2 points: one where flow was more than 10 ml.min-1.100 gm liver weight-1 (R), and the other where flow was less than 10 ml.min-1.100 gm liver weight-1 (P). After perfusion pressure had become stable, ATP or epinephrine was infused for 15 minutes. Perfusion pressure increased, and tissue flow of R decreased significantly, while that of P increased (not significantly). The extraction ratio of lidocaine decreased significantly by epinephrine, and that of oxygen decreased (not significantly). We conclude that in the ischemic liver, vasoconstriction results in changes in the distribution of tissue blood flow and alters drug metabolism.

Adenosine Triphosphate↗