Search PubMed⌕ Search

Biomedical subjects

S Nakao

Publications and source records attributed to S Nakao.

At least 91 records · Page 5Linked to original sources
PubMed2000

The anticonvulsant effects of volatile anesthetics on penicillin-induced status epilepticus in cats.

UNLABELLED: Volatile anesthetics may be used to treat status epilepticus when conventional drugs are ineffective. We studied 30 cats to compare the inhibitory effects of sevoflurane, isoflurane, and halothane on penicillin-induced status epilepticus. Anesthesia was induced and maintained with one of the three volatile anesthetics in oxygen. Penicillin G was injected into the cisterna magna, and the volatile anesthetic discontinued. Once status epilepticus was induced (convulsive period), the animal was reanesthetized with 0.6 minimum alveolar anesthetic concentration (MAC) of the volatile anesthetic for 30 min, then with 1.5 MAC for the next 30 min. Electroencephalogram and multiunit activity in the midbrain reticular formation were recorded. At 0.6 MAC, all anesthetics showed anticonvulsant effects. Isoflurane and halothane each abolished the repetitive spike phase in one cat; isoflurane reduced the occupancy of the repetitive spike phase (to 27%+/-22% of the convulsive period (mean +/- SD) significantly more than sevoflurane (60%+/-29%; P < 0.05) and halothane (61%+/-24%; P < 0.05), and the increase of midbrain reticular formation with repetitive spikes was reduced by all volatile anesthetics. The repetitive spikes were abolished by 1.5 MAC of the anesthetics: in 9 of 10 cats by sevoflurane, in 9 of 9 cats by isoflurane, and in 9 of 11 cats by halothane. In conclusion, isoflurane, sevoflurane, and halothane inhibited penicillin-induced status epilepticus, but isoflurane was the most potent. IMPLICATIONS: Convulsive status epilepticus is an emergency state and requires immediate suppression of clinical and electrical seizures, but conventional drugs may be ineffective. In such cases, general anesthesia may be effective. In the present study, we suggest that isoflurane is preferable to halothane and sevoflurane to suppress sustained seizure.

Anesthetics, Inhalation↗
PubMed2000

The anticonvulsant effects of volatile anesthetics on lidocaine-induced seizures in cats.

UNLABELLED: Large concentrations of sevoflurane and isoflurane, but not halothane, induce spikes in the electroencephalogram. To elucidate whether these proconvulsant effects affect lidocaine-induced seizures, we compared the effects of sevoflurane, isoflurane, and halothane in cats. Fifty animals were allocated to 1 of 10 groups: 70% nitrous oxide (N2O), 0.6 minimum alveolar anesthetic concentration (MAC) + 70% N2O, 1.5 MAC + 70% N2O, and 1.5 MAC of each volatile agent in oxygen. Lidocaine 4 mg x kg(-1) x min(-1) was infused IV under mechanical ventilation with muscle relaxation. Electroencephalogram in the cortex, amygdala, and hippocampus and multiunit activities in the midbrain reticular formation (R-MUA) were recorded. Lidocaine induced spikes first from the amygdala or hippocampus in the 70% N2O and halothane groups and from the cortex in the sevoflurane and isoflurane groups. Lidocaine induced seizures in all cats in the 70% N2O and 0.6 MAC + N2O groups. Seizure occurrence was reduced in the 1.5 MAC + N2O group (P < 0.05 versus 70% N2O). The onset of seizure was delayed in the 0.6 MAC + N2O and 1.5 MAC groups for sevoflurane and isoflurane, but not for halothane, compared with the 70% N2O group (P < 0.05). Lidocaine increased R-MUA with seizure by 130%+/-56% in the 70% N2O group. The increase of R-MUA with seizure was more suppressed in the volatile anesthetic groups than in the 70% N2O group (P < 0.05). In the present study, sevoflurane and isoflurane attenuated seizure when the blood lidocaine concentration was accidentally increased. IMPLICATIONS: Increasingly, epidural blockade is combined with general anesthesia to achieve stress-free anesthesia and continuous pain relief in the postoperative period. In the present study, sevoflurane and isoflurane attenuated seizure when the blood lidocaine concentration was accidentally increased.

Anesthetics, Inhalation↗
PubMed2000

Flow-mediated vasodilation and plasma fibronectin levels in preeclampsia.

To clarify the vascular endothelial function in pregnant women with hypertensive disorders, we assessed the flow-mediated vasodilation in the radial artery and compared it with plasma fibronectin levels. We determined flow-mediated vasodilation by measuring the change in radial artery diameter during hyperemia in 58 normal pregnant women, 22 preeclamptic pregnant women, and 15 pregnant women with chronic hypertension. In 41 of the 95 pregnant women, we measured the plasma fibronectin levels. Flow-mediated vasodilation in preeclamptic women was significantly less than that in normal pregnant women (P:<0.001). In chronic hypertensive women, flow-mediated vasodilation was significantly less than that in normal pregnant women (P:<0.001) but more than that in preeclamptic women (P:<0.001). Flow-mediated vasodilation showed significant negative correlation with plasma fibronectin levels (P:<0.001, r=0.73). Our results indicate that the endothelial function can be noninvasively assessed in pregnant women with hypertensive disorders by measuring the flow-mediated vasodilation of the radial artery with high-resolution ultrasound.

Adult↗
PubMed2000

Delayed neutrophil elastase inhibition prevents subsequent progression of acute lung injury induced by endotoxin inhalation in hamsters.

To define the role of neutrophil elastase (NE) in the progression of acute lung injury (ALI), we examined the effects of post-treatment with a specific NE inhibitor, sivelestat sodium hydrate (sivelestat), on ALI induced by endotoxin (ET) inhalation in hamsters. Inhalation of ET (300 microg/ml, 30 min) in conscious hamsters increased inflammatory cell count, protein concentration, and hemorrhage in bronchoalveolar lavage fluid (BALF) that peaked 24 h after ET inhalation. These changes were significant 2 h after ET inhalation and paralleled the increase in NE activity in BALF. When intravenously infused from 2 to 24 h post-ET inhalation, sivelestat (0.03 to 3 mg/kg/h) dose-dependently attenuated changes in these BALF parameters at 24 h post-ET inhalation in a manner dependent on the inhibition of NE activity in BALF. Histopathological analysis also indicated that sivelestat prevented the progression of lung inflammation such as alveolar neutrophil infiltration and hemorrhage. In contrast, dexamethasone (3 mg/kg, intravenously) was not effective in this model when administered 2 h after ET inhalation, although it was highly effective when applied before ET. We conclude that delayed inhibition of NE activity with sivelestat prevents subsequent progression of ALI in hamsters after ET inhalation. Thus NE may play an important role in the progression of ALI.

Animals↗
PubMed2000

The McCoy laryngoscope, external laryngeal pressure, and their combined use.

The efficacy of the McCoy laryngoscope, external laryngeal pressure, and their combination to improve the laryngoscopic view was evaluated in 219 patients and compared with the Macintosh laryngoscope. An experienced laryngoscopist performed laryngoscopy twice using the Macintosh laryngoscope and the McCoy laryngoscope in a random sequence, and external laryngeal pressure was applied in each laryngoscopy with the laryngoscopist's right hand. The laryngoscopic view obtained was graded on our modified Cormack's method. Without external laryngeal pressure, the McCoy laryngoscope provided a better laryngoscopic view than that obtained by the Macintosh laryngoscope (P < 0.001, signed rank test), but the view was worse than that with the Macintosh laryngoscope under external laryngeal pressure (P < 0.001). The McCoy laryngoscope combined with external laryngeal pressure provided a better view than the Macintosh laryngoscope with external laryngeal pressure (P < 0.001).

Equipment Design↗
PubMed2000

[Pulmonary infection caused by Mycobacterium gordonae in immunocompetent patient].

We report a case of 67-year-old female immunocompetent patient admitted to our hospital because of hemoptysis. Computed tomography (CT) of the lung showed bronchiectasis in the right S5 and small nodules in the right S6 and left S5. The cultures of sputum and bronchial washing specimen repeatedly revealed acid-fast bacilli identified as Mycobacterium gordonae (M. gordonae) by DNA-DNA hybridization (DDH) method. Thus, she was diagnosed to be infected with M. gordonae. She was treated with isoniazid, rifampicin, ethambutol and streptomycin. After treatment, the cultures of sputum and bronchial washing specimen converted to negative, and the chest CT showed improvement of small nodules. M. gordonae is a nontuberculous mycobacterium of very low pathogenic potency. Recently there have been a few reports of infection by M. gordonae not only in immunocompromised patients but also in immunocompetent patients. These cases were considered to be sensitive to initial standard antimycobacterial therapy, therefore, it is important to examine for M. gordonae in cases suspected of nontuberculous mycobacterial infection.

Aged↗
PubMed2000

[Myocardial disease in inherited disease].

To detect cardiac Fabry's disease, plasma alpha-galactosidase activity was measured in 230 male patients with left ventricular hypertrophy (LVH). Seven patients were diagnosed as having cardiac Fabry's disease. They did not have typical clinical manifestations of Fabry's disease. All seven had symmetric LVH. Endomyocardial biopsies revealed marked sarcoplasmic vacuolization in all five patients examined. Typical lysosomal inclusions with a concentric lamellar configuration were observed. Two novel mutations, A20P in exon 1 and M296I in exon 6, were detected in two patients, respectively. The remaining five had no mutations in the coding region for the alpha-galactosidase gene, and had marked decreases in the amount of alpha-galactosidase mRNA. Cardiac Fabry's disease should be considered as one of the cause of LVH.

Biomarkers↗
PubMed2000

[A case of pulmonary tuberculosis complicated with multiple bone and joint tuberculosis].

A 29-year-old male complaining of fever and general fatigue was admitted to our hospital. On admission chest X-ray showed infiltrative shadows with cavities in the bilateral lung apical areas, and sputum examination for acid fast bacilli was smear positive, Gaffky 1. He was treated as pulmonary tuberculosis (TB), and chest X-ray findings and sputum examination improved after a few months of treatment with antituberculous chemotherapy (INH, RFP, EB, PZA). However, tuberculous cold abscess appeared in retropharyngeal area, subcutaneous tissue of thoracic cage and retroperitoneal space, and shortly later, bone and joint TB were recognized in shoulder and wrist joints and vertebrae. The findings of vertebral foci were not recognized by a simple X-ray picture of vertebrae. at that time, but MRI of vertebrae showed low intensity areas with ring enhancement in the cervical, thoracic and lumbar vertebrae. Despite treatment with antituberculous agents, new bone and joint TB had developed in many tissues and had accompanied with cold abscess in adjacent tissue, whereas pulmonary TB had improved after the initial transient worsening. The appearance of bone and joint TB was most probably caused by the initial transient worsening of hidden bone and joint TB as a part of the initial systemic transient worsening of tuberculosis. After treatment for 4 months, pulmonary TB as well as bone and joints TB had improved. Tuberculous cold abscess in retropharyngeal may be secondary to cervical vertebral TB but is now rarely seen. In this case, involvement in many tissues such as retropharyngeal area, subcutaneous tissue of thoracic cage and retroperitoneal space were seen, and these findings are now uncommon and usually represents involvement secondary to contiguous infection.

Adult↗
PubMed2000

Consensus Conference on the Treatment of Aplastic Anemia.

This article presents guidelines for the diagnosis and treatment of aplastic anemia (AA) established by a consensus panel of investigators from various countries. The panel used the scientific evidence presented during the Consensus Conference forum and found in the scientific literature to prepare guidelines categorized as immunosuppressive therapy, unrelated bone marrow transplantation in patients with AA, and myelodysplasia/acute myeloid leukemia after immunosuppressive therapy.

Anemia, Aplastic↗
PubMed2000

[Non-Hodgkin's lymphoma in two married couples].

Couple 1: A 74-year-old woman was diagnosed as having diffuse large B-cell lymphoma (DLBL) by left axillary lymph node biopsy. About 6 months later, DLBL was also diagnosed in her 79-year-old husband by right submandibular lymph node biopsy. Although the wife achieved partial remission with chemotherapy, she died due to disease progression. The husband's disease was chemotherapy-resistant, and he died of renal failure. Couple 2: An 86-year-old man was diagnosed as having DLBL by left axillary lymph node biopsy. About 4 years later, DLBL was also diagnosed in his 86-year-old wife by left axillary lymph node biopsy. Both the husband and the wife received chemotherapy. The husband is currently alive in complete remission, and although the wife achieved partial remission, she died due to disease progression. In both of these couples, it was considered unlikely that Epstein-Barr virus or human T-cell lymphotropic virus type I was related to the development of non-Hodgkin's lymphoma, and no environmental factors were confirmed to be involved. It is postulated that other unknown factors or agents may be associated with the development of lymphoma in married couples.

Aged↗
PubMed2000

[Results of surgery in Mycobacterium avium complex pulmonary disease].

Recently, several studies have revealed the usefulness of surgical therapy for nontuberculous mycobacterial (NTM) disease. We have encountered and taken many opportunities for surgical therapy in Mycobacterium avium complex (MAC) disease. From April 1995 through March 1999, 14 patients with MAC disease underwent 16 pulmonary resections. NTM was diagnosed at our hospital in all subjects according to the criteria of the American Thoracic Society. There were 8 women and 6 men, with a mean age of 54 years. The most common indications for surgery were localized lesion (7 cases), severe symptoms (5 cases) and progressive disease (2 cases). Twelve patients were receiving multidrug chemotherapy, 10 of whom were also receiving clarithromycin. The mean period of preoperative chemotherapy was 17 months. Ten patients had a variety of symptoms, with some combination of cough, sputum, hemosputum, dyspnea, fever and anorexia. About 30% of the symptoms were improved after preoperative chemotherapy. The symptoms disappeared in all except one patient, who underwent pneumonectomy. After surgery, all patients attained a sputum-negative status. Nine patients underwent 11 partial resections, comprising 3 thoracotomies and 8 video-assisted thoracic surgeries (VATS). There was no operative mortality. Re-operation was performed in a patient with bronchopleural fistula after initial surgery. Currently, 2 months after the last operation, we have encountered no other severe complication and no relapse. Surgery may play an important role in treatment of MAC disease. We recommend partial resection with VATS for localized MAC disease.

Adult↗
PubMed1999

Characterization of T-cell repertoire of the bone marrow in immune-mediated aplastic anemia: evidence for the involvement of antigen-driven T-cell response in cyclosporine-dependent aplastic anemia.

To determine whether the antigen-driven T-cell response is involved in the pathogenesis of aplastic anemia (AA), we examined the complementarity-determining region 3 (CDR3) size distribution of T-cell receptor (TCR) beta-chain (BV) subfamilies in the bone marrow (BM) of untreated AA patients. AA patients who did not respond to immunosuppressive therapy and those who obtained unmaintained remission early after cyclosporine (CyA) or antithymocyte globulin (ATG) therapy exhibited essentially a normal CDR3 size pattern. In contrast, five patients who needed continuous administration of CyA to maintain remission exhibited a skewed CDR3 size pattern in a number (>40%) of BV subfamilies suggestive of clonal predominance. The skewing of CDR3 size distribution became less pronounced in one of the CyA-dependent patients when the patient achieved unmaintained remission after a 4-year therapy with CyA, whereas it persisted longer than 7 years in the other patient requiring maintenance therapy. Sequencing of BV15 cDNA for which the CDR3 size pattern exhibited apparent clonal predominance in all CyA-dependent patients showed high homology of the amino acid sequence of the CDR3 between two different patients. These findings indicate that antigen-driven expansion of T cells is involved in the pathogenesis of AA characterized by CyA-dependent recovery of hematopoiesis.

Adolescent↗
PubMed1999

Successful treatment of persistent erythroid aplasia caused by parvovirus B19 infection in a patient with common variable immunodeficiency with low-dose immunoglobulin.

Parvovirus B19 causes persistent erythroid aplasia in immunocompromised hosts. From April through July 1996, we encountered five adult patients presenting with reticulocytopenia and fever caused by parvovirus B19 infection. The reticulocyte count of four patients with normal immunity recovered within two weeks after the onset of fever. However, in the one remaining patient with common variable immunodeficiency (CVI), reticulocytopenia, and other symptoms including fever and the elevation of lactate dehydrogenase (LDH) levels persisted beyond 16 days of onset. Although the DNA of parvovirus B19 was detected in the peripheral blood of the CVI patient, neither immunoglobulin Ig-G nor Ig-M antibodies specific to the virus were detectable. We administered 50 mg/kg of Ig to the CVI patient for six days. The reticulocyte count recovered promptly on the sixth day of the treatment and parvovirus B19 DNA was not detectable 30 days after therapy. This indicates that although patients with CVI may be susceptible to persistent erythroid aplasia during an endemic of parvovirus B19, the complication can be treated successfully with relatively low-dose Ig.

Adult↗
PubMed1999

Frequency domain heart rate variability and plasma norepinephrine level in the coronary sinus during handgrip exercise.

BACKGROUND: Heart rate (HR) variability has been recognized as an important noninvasive index of autonomic nervous activities. However, the relationship between HR variability and cardiac circulating norepinephrine (NE), especially with respect to coronary ischemia, remains unclear. HYPOTHESIS: This study was undertaken to determine whether HR variability indices can reflect cardiac NE levels during handgrip exercise. METHODS: We simultaneously measured HR variability and cardiac NE overflow rate in 32 patients (30 men, 2 women) during a 6-min isometric handgrip exercise. Among the 32 subjects, 20 (19 men, 1 woman) had coronary artery disease (CAD) and 12 (control group; 11 men, 1 woman) did not. RESULTS: Hemodynamics and cardiac NE overflow rates among subjects at rest were not significantly different between the two groups. In the normal subjects, low-frequency (LF) spectra and LF/HF (high-frequency) ratios were not significantly changed during handgrip exercise, but HF spectra significantly increased from 10.1 +/- 4.5 to 12.2 +/- 7.0 ms (p < 0.05). In the subjects with CAD, LF and LF/HF spectra were significantly (p < 0.05 and 0.01, respectively) increased by handgrip exercise. High-frequency spectra were not significantly changed by handgrip exercise. In the normal subjects, a significant negative relation (r = -0.76, p < 0.01) was obtained between HF change and cardiac NE overflow rate, whereas this relationship was not significant in the subjects with CAD. The correlation between changes of LF/HF and cardiac NE overflow rate was significant in the normal (r = 0.56, p < 0.05) but not in subjects with CAD. CONCLUSION: These results suggest that vagal modulation of HR variability is more prominent in normal coronary artery subjects than in CAD subjects during handgrip exercise. Heart rate variability indices may thus serve as adequate indicators of autonomic nerve activity in subjects with normal coronary arteries but not in those with CAD, probably due to decreased adaptation to physical stress during handgrip exercise.

Blood Pressure↗