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Biomedical subjects

M Hayashi

Publications and source records attributed to M Hayashi.

At least 235 records · Page 13Linked to original sources
PubMed2001

[A case of thoracic vertebral tuberculosis associated with pulmonary sarcoidosis].

A 56-year-old woman was admitted to our hospital, on October 10, 1999 because of tingling numbness of the Th3 area and paraparesis. Her medical history included the diagnosis of pulmonary sarcoidosis which had responded to steroid therapy. On radiographic examination, a Th2 compression fracture and gadolinium enhanced areas were shown in MRI. We diagnosed vertebral sarcoidosis and restarted steroid therapy. Next day, she had no paresis and she was discharged after 20 days. However, the patient returned to our hospital with recurrence of the same pain and paraparesis on January 1, 2000, and spinal fusion of the Th2-3 was performed by a transpleural anterolateral approach using a block of iliac bone as a graft. Histology and cultural studies of tissue revealed tuberculosis. There is a diagnostic dilemma, "sarcoidosis or tuberculosis?", but it is necessary to be aware of this at the time of the initial diagnosis.

Female↗
PubMed2001

[Nationwide sensitivity surveillance of various antibiotic activities against bacteria isolated from patients with severe infections].

The susceptibility of 3,058 bacterial strains isolated between January and March, 1997 from patients with severe infections in Japan to ciprofloxacin and other injectable antimicrobial agents was measured using broth microdilution method. Methicillin-resistant Staphylococcus aureus (MRSA) strains were generally sensitive to vancomycin, teicoplanin and arbekacin, and resistant to CPFX and other antibacterial agents. MIC90 of CPFX against Streptococcus pneumoniae, to which MIC of ampicillin was more than 4 micrograms/mL, was below 2 micrograms/mL. PRSP (Penicillin resistant S. pneumoniae), which was also resistant to cephalosporins and carbapenems, showed no cross-resistance to CPFX. The susceptibility of Gram-negative bacteria to CPFX was as high as that to carbapenems. Especially, MIC90 against Pseudomonas aeruginosa was 2 micrograms/mL. 3 strains of isolated 446 P. aeruginosa strains had blaIMP gene. CPFX and pazufloxacin demonstrated good susceptibility with 0.25 microgram/mL of MIC to 2 strains of these 3 strains. The susceptibility rate of the most common isolates from patients suffering from lower respiratory tract infections excluding MRSA to CPFX was more than 80% (indication: % strains < pneumonia break point).

Anti-Bacterial Agents↗
PubMed2001

[Developmental consultation conducted by Yokohama Rehabilitation Center at health welfare offices--combination of early impairment detection and support nursing].

We report here the results of developmental consultation carried out at Yokohama City health welfare offices. From October 1992 to March 1998, we consulted 666 cases aged 1 to 56 months old. We made full use of the reflex rolling I of Vojta for therapeutic diagnosis, and conducted physical training for babies. The reflex rolling I was very useful in diminishing the mother's anxiety about nursing problems such as weak suckling, sleep disturbance and constipation. Since it is important to combine the early detection of impairments with the support for nursing, advices to achieve better development were given to the parents and children. In our developmental consultation we could select babies at risk early and thereby start therapy for them smoothly.

Child Development↗
PubMed2001

[The effect of lidocaine on the bispectral index during anesthesia induction with propofol].

We investigated the effect of premixing lidocaine with propofol on a bispectral index (BIS) during propofol infusion. We studied 40 adult patients given mixture of 1% propofol 20 ml with 2 ml of normal saline (control group) or 2% lidocaine (lidocaine group) infused at 2 ml.kg-1.hr-1 for 10 minutes. Heart rate, mean arterial pressure, and BIS were measured every minute. The addition of lidocaine to propofol reduced the incidence of injection pain from 85% to 10% but did not change the induction time. Propofol significantly decreased mean arterial pressure and BIS but there was no difference between the groups. In conclusion, premixing lidocaine with propofol reduces injection pain without affecting the hypnotic effect.

Adult↗
PubMed2001

[Efficacy of bispectral index for anesthetic management of combined off-pump coronary artery bypass grafting and abdominal aortic aneurysm replacement].

A 57-year-old female patient underwent combined off-pump coronary artery bypass grafting and abdominal aortic aneurysm replacement. Anesthesia was maintained with propofol, fentanyl, and thoracic epidural anesthesia. Propofol doses were adjusted to maintain bispectral index (BIS) between 40-60. Despite the remarkable hemodynamic changes, BIS remained stable at about 50 during the surgery. The average dose of propofol was 3.3 mg.kg-1.hr-1. The patient awoke an hour after the surgery and was extubated 1.5 hours thereafter. This case report suggests that BIS is a useful index to determine the depth of anesthesia during surgeries which induce marked hemodynamic changes.

Anesthesia↗
PubMed2001

A patient with diabetes mellitus and severe arterial embolism.

An 89-year-old man with diabetes mellitus was admitted to the hospital because of a low-grade fever and a disturbance in consciousness. He had been diagnosed as having diabetes mellitus at the age of 22 years and had been taking oral hypoglycemic drugs for 16 years at least. A few days before admission, a loss of appetite was noticed by his family; he developed a stupor on the day of admission. On physical examination, his lower extremities were pale and his skin temperature was low. Laboratory tests showed an increase in his white blood cell count and his blood culture was positive for Staphylococcus aureus. An MRI showed that the abdominal aorta was totally occluded beneath the renal arteries, and no significant collateral circulation was observed. He was given antibiotics and anticoagulants, but his general condition continued to worsen. Laboratory tests showed renal failure and liver dysfunction, indicating multi-organ failure. On the 24th day of admission, he died of respiratory and heart failure. An autopsy showed the aorta to be totally occluded beneath the renal arteries by an embolism; atherosclerotic changes were rather mild. Acute plaque change on the surface of the aorta may have induced the sudden development of emboli in the aorta.

Acute Kidney Injury↗
PubMed2001

[Mechanisms involved in large subcortical infarcts].

Large subcortical infarcts(maximum diameter of infarct > or = 20 mm) result from various stroke patterns, including striatocapsular infarcts (SCI), corona radiata infarcts, centrum semiovale infarcts, and internal borderzone infarcts. A systematic investigation of stroke pathogenesis involved in large subcortical infarcts, however, has not been performed. This study attempted to clarify the stroke mechanisms involved in large subcortical infarcts, by examining 50 patients with large subcortical infarcts out of 430 ischemic stroke patients consecutively registered in our department. The subjects were divided into two groups according to the vascular territories involved on the MRI: 1) the lenticulostriate arteries group for 39 patients whose infarcts were restricted to within the vicinity of the lenticulostriate arteries; 2) the internal borderzone group for 11 patients whose infarcts mainly involved the internal borderzone (the upper part of the corona radiata and the centrum semiovale) between the territories of the deep perforating branches from the basal cerebral arteries and the medullary branches from the superficial pial arteries. Stroke pathogenesis were classified into the following 6 categories: A) cardiogenic embolism, 9 patients; B) artery-to-artery embolism, 6 patients; C) cryptogenic embolism, 2 patients; D) thrombotic MCA (M1) occlusion, 9 patients; E) thrombotic ICA occlusion, 10 patients; F) undetermined cause, 14 patients. The lenticulostriate arteries group consisted of 9 patients with cardiogenic embolism, 6 with artery-to-artery embolism, 2 with cryptogenic embolism, 8 with thrombotic M1 occlusion, and 14 with undetermined cause. The internal borderzone group consisted of 10 patients with thrombotic ICA occlusion and 1 patient with thrombotic M1 occlusion. The stroke pathogenesis of the undetermined cause is considered to be thrombotic occlusion at the orifice of the lateral lenticulostriate artery, a so-called "branch atheromatous disease (BAD)". The patients in this group experienced a gradual onset, and did not have a cardiac source of the embolism or proximal large artery disease. Among the patients reported as having SCI, BAD may play a role in some cases, especially in those whose the cause was classified as "undetermined". In conclusion, the lenticulostriate arteries group exhibited a higher frequency of cerebral embolisms (cardiogenic embolism, artery-to-artery embolism, and cryptogenic embolism) and thrombotic M1 occlusion, whereas the internal borderzone group had a higher frequency of thrombotic ICA occlusion.

Aged↗
PubMed2001

[Acute onset of tuberculous meningoencephalitis presenting with symmetric linear lesions in the bilateral thalamus: a case report].

A 18-year-old woman was admitted to our hospital because of high fever and headache. Nuchal stiffness was present, and a CSF examination showed lymphocyte-domonant pleocytosis and a decreased level of glucose. Although antibiotics, aciclovir and an antimycotic drug were administered, disturbance of consciousness, involuntary movements, and pyramidal tract signs appeared. Soon after the medications were changed to antituberculous medicines, the meningoencephalitis started to subside, and was finally cured. Judging from the clinical findings, the CSF findings, the effectiveness of antituberculous medicines, an elevated ADA level in CSF, and positive conversion in tuberculin tests, the final diagnosis was made as tuberculous meningoencephalitis. At the severest stage of the disease, a brain MRI showed symmetric, linear lesions without the effect of Gd-enhancement in the bilateral thalamus, which thereafter disappeared along with the healing of the illness. From all these things, we conclude that thalamic and other parenchymal lesions should be kept in mind in case of acute tuberculous meningoencephalitis.

Acute Disease↗
PubMed2001

[Japanese guidelines on research use of human materials and disease information].

Demand on the use of human materials and personal disease information for research and development comes on the stage of action. International competition in biomedical and pharmaceutical research pushed the government and related societies about to release guidelines on the issue to ensure the protection of direct and indirect research participants. To work on human materials and information now requires ethical and scientific review by the research ethical committee and the guidelines set the stage of reviewing process. We should aware of the overall view of situation around and of the guidelines before planning the experiments and analyses on human materials and personal information. In this review we summarized the related guidelines and put comments on them to help researchers to understand the situation.

Embryo, Mammalian↗
PubMed2000

A new member of the HCO3(-) transporter superfamily is an apical anion exchanger of beta-intercalated cells in the kidney.

The kidneys play pivotal roles in acid-base homeostasis, and the acid-secreting (alpha-type) and bicarbonate-secreting (beta-type) intercalated cells in the collecting ducts are major sites for the final modulation of urinary acid secretion. Since the H(+)-ATPase and anion exchanger activities in these two types of intercalated cells exhibit opposite polarities, it has been suggested that the alpha- and beta-intercalated cells are interchangeable via a cell polarity change. Immunohistological studies, however, have failed to confirm that the apical anion exchanger of beta-intercalated cells is the band 3 protein localized to the basolateral membrane of alpha-intercalated cells. In the present study, we show the evidence that a novel member of the anion exchanger and sodium bicarbonate cotransporter superfamily is an apical anion exchanger of beta-intercalated cells. Cloned cDNA from the beta-intercalated cells shows about 30% homology with anion exchanger types 1-3, and functional expression of this protein in COS-7 cells and Xenopus oocytes showed sodium-independent and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid-insensitive anion exchanger activity. Furthermore, immunohistological studies revealed that this novel anion exchanger is present on the apical membrane of beta-intercalated cells, although some beta-intercalated cells were negative for AE4 staining. We conclude that our newly cloned transporter is an apical anion exchanger of the beta-intercalated cells, whereas our data do not exclude the possibility that there may be another form of anion exchanger in these cells.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed2000

Hepatocarcinogen quinoline induces G:C to C:G transversions in the cII gene in the liver of lambda/lacZ transgenic mice (MutaMouse).

Quinoline is carcinogenic to the liver in rodents, but it is not clear whether it acts by a genotoxic mechanism. We previously demonstrated that quinoline does induce gene mutation in the liver of lambda/lacZ transgenic mice. In the present report, we reveal the molecular nature of the mutations induced by quinoline in the lambda cII gene, which is also a phenotypically selectable marker in the lambda transgene. (The cII gene has 294bp, which enables much easier sequence analysis than the original lacZ gene (3kb)). The liver cII mutant frequency was nine times higher in quinoline-treated mice than in control mice. Sequence analysis revealed that quinoline induced primarily G:C to C:G transversions (25 of 34). Thus, we have confirmed that quinoline is genotoxic in its target organ, and the G:C to C:G transversion is the molecular signature of quinoline-induced mutations.

Animals↗
PubMed2000

In vivo rodent micronucleus assay: protocol, conduct and data interpretation.

In vivo rodent micronucleus assay has been widely used to detect genotoxicity. Evaluation of micronucleus induction is the primary in vivo test in a battery of genotoxicity tests and is recommended by the regulatory agencies around the globe to be conducted as part of product safety assessment. The assay, when performed appropriately, detects both clastogenicity and aneugenicity. Methods for performing micronucleus evaluation have evolved since its initial description in the 1970s. In recent years, the focus has been directed toward improving micronucleus detection with high efficiency by proposing data-based recommendations to the standard initial protocol design. Such improvements include, e.g., the use of appropriate harvest time(s), inclusion of one or both sexes, number of doses tested, limit dose, integrating micronucleus assessment into the routine toxicology studies, use of fluorescent staining, automation of micronucleus detection and assessment of micronuclei in multiple tissues. This protocol paper describes: the mechanism of micronucleus formation, a generalized protocol for manual detection, enumeration of micronuclei, and data interpretation in light of published information thus far, on the regulatory aspects of this assay. Certain recent protocol issues that are practical in nature are equally valid in relation to standard manual method and provide robust database, which are also included for consideration. It is expected that such improvements of the protocol will continue to drive the utility of this assay in the product safety assessment.

Animals↗
PubMed2000

Prognostic value of genetically diagnosed lymph node micrometastasis in non-small cell lung carcinoma cases.

The predictive value of lymph node micrometastasis, detected by immunohistochemical or genetic methods, is well appreciated in terms of prognosis. However, a major problem is high false-positive rates, because most methods focus on cytokeratin, which is a component not only of carcinoma but also normal epithelial and nonepithelial cells. Mutant allele-specific amplification (MASA) can detect DNAs derived from cancer cells itself, reportedly with high sensitivity. It was, therefore, used with nested-PCR using p53 or K-ras mutation for analysis of lymph node micrometastasis in non-small cell lung carcinoma (NSCLC) patients in the present study, in comparison with the immunohistochemical method using an anti-cytokeratin reagent for the same samples. Lymph nodes from 31 NSCLC patients with p53 and K-ras mutated tumors (30 and 1, respectively) staged as pathological (p)-T1-4 N0-1 and M0 were examined. Genetic and immunohistochemical methods demonstrated positive reactions in 34 (15%) and 61 (27%) of 229 lymph nodes, respectively (9 cases, 29%, and 24 cases, 77%). The concordance with the two methods was 77%, but 13 (39%) of 34 genetically positive lymph nodes could not be detected by immunohistochemistry (IHC). Of 22 cases with p-N0 disease, 6 (27%) were genetically positive in hilar and/or mediastinal lymph nodes, and 4 (67%) of them died after cancer relapse. In contrast, none of the patients without micrometastasis died of cancer (P < 0.001, log rank analysis). Of the same p-N0 patients, 17 (77%) were positive by IHC, and 4 (24%) of them died of cancer, whereas 5 negative patients did not suffer cancer relapse. Survival did not significantly differ between cases positive and negative (P = 0.246) by IHC. According to the g-N (N factor restaged by a genetic method), patients with g-N1 and g-N2 disease had a shorter survival than those with g-N0 disease (P = 0.042 and P < 0.001, respectively). However, no significant difference was observed with grading by IHC. Thus, detection of micrometastasis in regional lymph nodes with the MASA method, in other words with a carcinoma-specific marker, is of greater prognostic significance for early stage NSCLC patients than immunohistochemical results. This approach should facilitate selection of patients for whom postoperative adjuvant chemotherapy should be performed.

Adenocarcinoma↗
PubMed2000

Vacuolar H(+)-ATPase localized in plasma membranes of malaria parasite cells, Plasmodium falciparum, is involved in regional acidification of parasitized erythrocytes.

Recent biochemical studies involving 2',7'-bis-(2-carboxyethyl)-5, 6-carboxylfluorescein (BCECF)-labeled saponin-permeabilized and parasitized erythrocytes indicated that malaria parasite cells maintain the resting cytoplasmic pH at about 7.3, and treatment with vacuolar proton-pump inhibitors reduces the resting pH to 6.7, suggesting proton extrusion from the parasite cells via vacuolar H(+)-ATPase (Saliba, K. J., and Kirk, K. (1999) J. Biol. Chem. 274, 33213-33219). In the present study, we investigated the localization of vacuolar H(+)-ATPase in Plasmodium falciparum cells infecting erythrocytes. Antibodies against vacuolar H(+)-ATPase subunit A and B specifically immunostained the infecting parasite cells and recognized a single 67- and 55-kDa polypeptide, respectively. Immunoelectron microscopy indicated that the immunological counterpart of V-ATPase subunits A and B is localized at the plasma membrane, small clear vesicles, and food vacuoles, a lower extent being detected at the parasitophorus vacuolar membrane of the parasite cells. We measured the cytoplasmic pH of both infected erythrocytes and invading malaria parasite cells by microfluorimetry using BCECF fluorescence. It was found that a restricted area of the erythrocyte cytoplasm near a parasite cell is slightly acidic, being about pH 6.9. The pH increased to pH 7.3 upon the addition of either concanamycin B or bafilomycin A(1), specific inhibitors of vacuolar H(+)-ATPase. Simultaneously, the cytoplasmic pH of the infecting parasite cell decreased from pH 7.3 to 7.1. Neither vanadate at 0.5 mm, an inhibitor of P-type H(+)-ATPase, nor ethylisopropylamiloride at 0.2 mm, an inhibitor of Na(+)/H(+)-exchanger, affected the cytoplasmic pH of erythrocytes or infecting parasite cells. These results constitute direct evidence that plasma membrane vacuolar H(+)-ATPase is responsible for active extrusion of protons from the parasite cells.

Acids↗
PubMed2000

High levels of plasma brain natriuretic peptide and interleukin-6 after optimized treatment for heart failure are independent risk factors for morbidity and mortality in patients with congestive heart failure.

OBJECTIVES: The aim of this study was to evaluate whether repetitive measurements of plasma levels of neurohumoral factors and cytokines before and after additional treatment are useful for predicting mortality in patients with congestive heart failure (CHF). BACKGROUND: Neurohumoral and immune activation play an important role in the pathophysiology of CHF. However, the effects of serial changes in these factors on the prognostic value remain unknown. METHODS: We measured plasma levels of neurohumoral factors and cytokines and left ventricular ejection fraction (LVEF) before and three months after optimized treatment for CHF in 102 consecutive patients with severe CHF (New York Heart Association class III to IV) on admission to our hospital. Physicians who were blind to the plasma neurohumoral factors until study completion treated patients using standard drugs. Patients were monitored for a mean follow-up period of 807 days. RESULTS: Plasma levels of neurohumoral factors, cytokines and LVEF were significantly improved three months after optimized treatment. Cardiac death occurred in 26 patients. Among 19 variables including LVEF, only a high level of brain natriuretic peptide (BNP) and interleukin-6 (IL-6) at three months after optimized treatment showed significant independent relationships by Cox proportional hazard analysis with a high mortality for patients with CHF. CONCLUSIONS: These findings indicate that high plasma BNP and IL-6 levels three months after optimized treatment are independent risk factors for mortality in patients with CHF, suggesting that sustained high plasma levels of BNP and IL-6 after additional standard treatment were independent risk factors for mortality in patients with CHF despite improvements in LVEF and symptoms.

Aged↗