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Biomedical subjects

S Maeda

Publications and source records attributed to S Maeda.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Optimal treatment of intrathoracic extramedullary hematopoiesis resembling posterior mediastinal tumor; report of a case].

Intrathoracic extramedullary hematopoiesis is a rare condition accompanying chronic hematologic disease. We present a case of chronic gastric ulcer in which a posterior mediastinal mass was diagnosed as extramedullary hematopoiesis. We underwent video-assisted thoracoscopic resection safely and successfully. This procedure is relevant and safety procedure for differential diagnosis of patients who have chronic anemia with asymptomatic intrathoracic tumors.

Aged↗
PubMed2004

Molecular identification and immunohistochemical localization of atrial natriuretic peptide in the heart of the dromedary camel (Camelus dromedarius).

Atrial and B-type natriuretic peptide (ANP and BNP) are cardiac hormones synthesized and secreted by the myoendocrine cells of the heart. They exert potent actions on body fluid balance. Since various body organs including the heart are under high physiological stress during water and food deprivation in the desert nomads, we intended to perform molecular biological and histological studies of ANP in the heart of the dromedary camel Camelus dromedarius. Initially, we isolated cDNAs encoding ANP from the atrium and BNP from the atrium and ventricle of the dromedary camel. Putative mature ANP, deduced from the cDNA sequence, was identical to that of human and pig ANP, but the putative mature BNP was more diverse and was most similar to pig BNP (94% identity). Thus, we used antisera raised against human ANP that did not cross-react with pig BNP in the subsequent immunohistochemical studies. The ANP-expressing myoendocrine cells are most concentrated in the right atrium, to a lesser extent in the left atrium, and almost absent in the left ventricle. The immuno-positive cells are scattered uniformly in each region and are characterized by the presence of immunoreactive granular deposits around the nucleus. The left atrium comprises some ramifications of conductive cells (Purkinje fibers), some of which also contained ANP-immunoreactive granules. At the electron microscopic level, myoendocrine cells possessed secretory granules primarily in the perinuclear zone and a well-developed Golgi apparatus. The present study is the first comprehensive report dealing with the molecular cloning and immunohistochemical localization of ANP in the heart of a desert dwelling mammal.

Amino Acid Sequence↗
PubMed2004

The effect of cellular proliferative activity on recurrence and local tumour extent of localized giant cell tumour of tendon sheath.

This study investigates whether the proliferative activity of giant cell tumour of tendon sheath is related to its recurrence rate and local aggressiveness. The clinicopathological and immunohistochemical features of 30 localized giant cell tumours of tendon sheath were studied and the influence of the MIB-1 staining index on recurrence, tumour extent around the phalanx and involvement of the bone were evaluated. No significant difference in the MIB-1 staining index was found between the lesions which recurred and those which did not. Also there was no significant association between local aggressiveness and the MIB-1 staining index. These results suggest that the proliferative activity of localized giant cell tumour of tendon sheath is not related to its high recurrence rate and local aggressiveness.

Adolescent↗
PubMed2004

Identification of peptides containing T-cell epitopes of Japanese cedar (Cryptomeria japonica) pollen allergen (Cry j 1) in dogs.

Japanese cedar (Cryptomeria japonica, CJ) pollen has been known to cause atopic dermatitis in dogs in Japan. However, since the mechanism of the CJ antigen recognition is not well understood in dogs, it is difficult to develop effective immunotherapy for atopic dermatitis caused by sensitization to CJ pollen. In order to aim at development of a peptide immunotherapy, we tried to identify T-cell epitopes of a major allergen of CJ pollen, Cry j 1, in dogs sensitive to CJ pollen allergen. Peripheral blood mononuclear cells (PBMCs) obtained from 22 dogs experimentally sensitized to CJ pollen allergen and 5 atopic dogs sensitive to CJ pollen allergen were used for mapping of T-cell epitopes of Cry j 1 using 35 kinds of synthesized overlapping peptides of Cry j 1. Reactive peptides were identified based on the results of blastogenic responses of PBMCs against the peptides when the stimulation indices were beyond 2.0. Three reactive peptides were identical in a relatively high population of experimental dogs, which were Nos. 8 (p71-90) (41%), 10 (p91-110) (50%), and 11 (p101-120) (41%). It was considered that these synthesized peptides should contain T-cell epitopes of Cry j 1 in the dogs. However, there were no reactive peptides identical among the five atopic dogs spontaneously sensitive to CJ pollen. The population of dogs experimentally sensitized to CJ pollen antigen will be used in order to investigate effects of a peptide immunotherapy using the reactive peptides. The results in atopic dogs sensitive to CJ pollen antigen will also provide useful information on necessity to develop a tailor-made immunotherapy using reactive peptides in each dog.

Allergens↗
PubMed2004

Targeted conversion of the transthyretin gene in vitro and in vivo.

Familial amyloidotic polyneuropathy (FAP) is the common form of hereditary generalized amyloidosis and is characterized by the accumulation of amyloid fibrils in the peripheral nerves and other organs. Liver transplantation has been utilized as a therapy for FAP, because the variant transthyretin (TTR) is predominantly synthesized by the liver, but this therapy is associated with several problems. Thus, we need to develop a new treatment that prevents the production of the variant TTR in the liver. In this study, we used HepG2 cells to show in vitro conversion of the TTR gene by single-stranded oligonucleotides (SSOs), embedded in atelocollagen, designed to promote endogenous repair of genomic DNA. For the in vivo portion of the study, we used liver from transgenic mice whose intrinsic wild-type TTR gene was replaced by the murine TTR Val30Met gene. The level of gene conversion was determined by real-time RCR combined with mutant-allele-specific amplification. Our results indicated that the level of gene conversion was approximately 11 and 9% of the total TTR gene in HepG2 cells and liver from transgenic mice, respectively. Gene therapy via this method may therefore be a promising alternative to liver transplantation for treatment of FAP.

Amyloid Neuropathies↗
PubMed2004

Increase of CC chemokine receptor 4-positive cells in the peripheral CD4 cells in dogs with atopic dermatitis or experimentally sensitized to Japanese cedar pollen.

BACKGROUND: Since dogs frequently develop allergic diseases, similar to those in humans, dogs represent a possible animal model for allergy in humans. In human atopic dermatitis (AD), CC chemokine receptor 4 (CCR4) has been shown to play an important role in the development of allergic inflammation of AD; however, the association between allergic reaction and CCR4 is not well understood in dogs. OBJECTIVE: To examine CCR4 expression in peripheral blood CD4+ cells in dogs that had AD and were experimentally sensitized with Japanese cedar pollen. MATERIALS AND METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from 17 dogs with AD. The proportion of CCR4+ cells in peripheral blood CD4+ cells (CCR4/CD4) was evaluated by flow cytometry and compared with that in 10 healthy dogs. Similarly, in dogs that were experimentally sensitized to Japanese cedar pollen antigen, the proportion of CCR4/CD4 was examined pre- and post-sensitization. RESULTS: The proportion of CCR4/CD4 in dogs with AD was 40.3+/-3.3%, which was significantly higher than that in normal dogs (23.6+/-4.3%) (P<0.01). In the experimentally sensitized dogs, the proportion of CCR4/CD4 was 25.4+/-2.6% at pre-sensitization and it was significantly increased (29.8+/-2.9%) at post-sensitization (P<0.01). CONCLUSION: The proportion of CCR4+ cells in peripheral blood CD4+ cells was measured in dogs with allergic conditions. The present findings indicate that CCR4+ cells may be involved in the pathogenesis of allergy in dogs as in humans.

Allergens↗
PubMed2004

Intravenous sedation for dental patients with intellectual disability.

BACKGROUND: The poor quality of oral health care for people with intellectual disability (ID) has been recognized, and the strong fears about dental treatment suggested as a major reason for disturbances of visits to dentists by such patients. Intravenous sedation is a useful method for relieving the anxiety and fear of such patients about dental treatment, and is frequently essential for ID patients undergoing dental treatment. However, decision regarding the dose of sedative required to be administered for an adequate level of sedation is difficult because the effect of sedation cannot be adequately assessed in patients with severe ID. As an appropriate sedative dose for dental patients with ID has not been fully established, we investigated sedative doses required and the effect of sedation in patients with ID, compared with other dental patients. METHODS: We reviewed the anaesthetic records of dental patients with ID (73 cases) and other dental patients (19 cases) aged between 20 and 29 years who had undergone intravenous sedation with midazolam and propofol in Okayama University Dental Hospital, from January 2000 to December 2000. Intravenous sedation was induced with a bolus intravenous administration of midazolam (2-3 mg) and maintained with a continuous infusion of propofol. The dose of propofol was titrated to achieve an adequate level of sedation: asleep but responding to painful stimulation. The efficacy of sedation, the required doses of propofol, and the wake-up times were investigated for all subjects. The efficacy of sedation was evaluated by judging whether the patient became cooperative and allowed the dental treatment to be carried out or not. The complications induced by intravenous sedation were also evaluated in each subject. Differences in variables between subjects with ID and other subjects were analysed using the Mann-Whitney U-test. RESULTS: Intravenous sedation was effective for dental treatment in all subjects with or without ID. The required dose of propofol in subjects with ID was 4.74 mg/kg/h (2.63-10.33 mg/kg/h), significantly higher than that required for other subjects (3.31, 1.72-4.80 mg/kg/h). Wake-up times of subjects with ID were similar to those of the other subjects. Severe complications were not seen during or after intravenous sedation. CONCLUSION: The results of this study show that intravenous sedation is a useful method for dental patients with ID as well as for other dental patients, but indicate that dental patients with ID need higher doses of sedative to obtain an adequate level of sedation.

Adult↗
PubMed2003

Phase I clinical study of a novel lipophilic platinum complex (SM-11355) in patients with hepatocellular carcinoma refractory to cisplatin/lipiodol.

SM-11355 is a platinum complex developed to treat hepatocellular carcinoma (HCC). It is administered via the hepatic artery, using a carrier, lipiodol, that consists of ethyl esters of iodized poppy seed oil. We have performed a phase I clinical trial of an SM-11355-lipiodol formulation in 11 HCC patients, in order to investigate the maximum allowable dose and to maximize the efficacy and safety of the drug in the treatment of HCC. The SM-11355 arterial infusion suspension was administered at doses of 6, 12 and 20 mg ml(-1) in a maximum lipiodol volume of 6 ml. An antitumour efficacy rating of complete response was achieved for one patient and a partial response rating was achieved for a second patient, giving an overall response rate of 18.2%. Anorexia, nausea and vomiting, pyrexia, thrombocytopenia and increases in AST, ALT and total bilirubin were observed as adverse effects, but each was transient and each patient had recovered completely by 4 weeks after drug administration. Hence, we concluded that the maximum allowable dose was not reached in this study. Overall, our results suggest that SM-11355 is effective in treating HCC and we suggest that the dose for early phase II trials should be 20 mg ml(-1).

Adult↗
PubMed2003

Genomic sequence of a 320-kb segment of the Z chromosome of Bombyx mori containing a kettin ortholog.

The sex chromosome constitution of the silkworm, Bombyx mori, is ZW in the female and ZZ in the male. Very little molecular information is available about the Z chromosome in Lepidoptera, although the topic is interesting because of the absence of gene dosage compensation in this chromosome. We constructed a 320-kb BAC contig around the Bmkettin gene on the Z chromosome in Bombyx and determined its nucleotide sequence by the shotgun method. We found 13 novel protein-coding sequences in addition to Bmkettin. All the transposable elements detected in the region were truncated, and no LTR retrotransposons were found, in stark contrast to the situation on the W chromosome. In this 320-kb region, four genes for muscle proteins (Bmkettin, Bmtitin1, Bmtitin2, and Bmprojectin) are clustered, together with another gene (Bmmiple) on the Z chromosome in B. mori; their orthologs are also closely linked on chromosome 3 in Drosophila, suggesting a partial synteny. Real-time RT-PCR experiments demonstrated that transcripts of 13 genes of the 14 Z-linked genes found accumulated in larger amounts in males than in female moths, indicating the absence of gene dosage compensation. The implications of these findings for the evolution and function of the Z chromosome in Lepidoptera are discussed.

Amino Acid Motifs↗
PubMed2003

Avascular necrosis associated with fractures of the femoral neck in children: histological evaluation of core biopsies of the femoral head.

There is no well-documented effective treatment for avascular necrosis following fractures of the femoral neck in children. Six children who suffered avascular necrosis following these fractures were treated with a long period of non-weight bearing. We tried to predict the advisable period of non-weight bearing by histological finding on core biopsy taken from the femoral head and present long-term follow-up results. The time interval for the biopsy ranged from 4 to 21 months after injury. Two specimens obtained within 1 year after injury showed total necrosis. The other four specimens taken more than 1 year after injury showed partial repair. Two specimens obtained from patients who had minimally displaced fractures also revealed necrotic tissue. Four patients were initially placed non-weight bearing for over 1 year. Two patients started weight bearing immediately after surgery, and late segmental collapse occurred within 1 year. They were then placed non-weight bearing for a further period in excess of 1 year. All patients, including those who had severely displaced fractures, avoided severe collapse of the femoral head. To avoid severe collapse of the femoral head due to avascular necrosis after pediatric femoral neck fractures, a long period of non-weight bearing of at least 1 year may be recommended treatment.

Adolescent↗
PubMed2003

Nitric oxide at a low concentration protects murine macrophage RAW264 cells against nitric oxide-induced death via cGMP signaling pathway.

1. We investigated the cytoprotective effect of low-dose nitric oxide (NO) on NO-induced cell death in mouse macrophage-like cell line RAW264. 2. Sodium nitroprusside (SNP), an NO donor, at a high concentration (4 mM) released cytochrome c from mitochondria and induced death in RAW264 cells. Acetyl-L-aspartyl-L-glutamyl-L-valyl-L-aspart-1-al (Ac-DEVD-CHO, 100-200 microM), a caspase-3 inhibitor, attenuated the SNP-induced cell death in a concentration-dependent manner. 3. Pretreatment with 100 microM SNP for 24 h, which had no effect on cell viability, attenuated the cell death and reduced cytochrome c release from mitochondria to the cytosol induced by 4 mM SNP. 4. LY83583 (1-3 microM) and 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ, 30-100 microM), soluble guanylate cyclase inhibitors, negated the protective effect of the 100 microM SNP pretreatment. 5. Pretreatment with 1 mM dibutylyl guanosine-3',5'-cyclic monophosphate (DBcGMP), a cell-permeable guanosine-3',5'-cyclic monophosphate (cGMP) analogue, for 24 h inhibited both cytochrome c release and cell death induced by SNP. 6. Protein kinase G inhibitor KT5823 (10 microM) significantly reduced the cytoprotective effects of low-dose SNP and DBcGMP. 7. These results indicate that low-dose NO protects RAW264 cells from NO-induced apoptosis through cGMP production and activation of protein kinase G.

Animals↗
PubMed2003

Non-invasive assessment of cardiac output during exercise in healthy young humans: comparison between Modelflow method and Doppler echocardiography method.

AIMS: The Modelflow method can estimate cardiac output from arterial blood pressure waveforms using a three-element model of aortic input impedance (aortic characteristic impedance, arterial compliance, and systemic vascular resistance). We tested the reliability of a non-invasive cardiac output estimation during submaximal exercise using the Modelflow method from finger arterial pressure waveforms collected by Portapres in healthy young humans. METHODS: The Doppler echocardiography method was used as a reference method. Sixteen healthy young subjects (nine males and seven females) performed a multi-stage cycle ergometer exercise at an intensity corresponding to 70, 90, 110 and 130% of their individual ventilatory threshold for 2 min each. The simultaneous estimation of cardiac output (15 s averaged data) using the Modelflow and Doppler echocardiography methods was performed at rest and during exercise. RESULTS AND CONCLUSION: The Modelflow-estimated cardiac output correlated significantly with the simultaneous estimates by the Doppler method in all subjects (r = 0.87, P < 0.0001) and the SE of estimation was 1.93 L min-1. Correlation coefficients in each subject ranged from 0.91 to 0.98. Although the Modelflow method overestimated cardiac output, the errors between two estimates were not significantly different among the exercise levels. These results suggest that the Modelflow method using Portapres could provide a reliable estimation of the relative change in cardiac output non-invasively and continuously during submaximal exercise in healthy young humans, at least in terms of the relative changes in cardiac output.

Adult↗
PubMed2003

Exercise training improves ageing-induced decrease in eNOS expression of the aorta.

AIMS: Ageing impairs endothelial function such as the regulation of vascular tone. The release of nitric oxide (NO), which has a potent vasodilator effect and antiatherosclerotic property, is decreased in the aorta of aged rats. Exercise training, however, has been reported to increase the expression of endothelial NO synthase (eNOS) in the aorta of young rats. In aged rats, it is not known whether the expression of eNOS is altered by exercise training. We hypothesized that exercise training would improve the ageing-induced decrease in eNOS expression in vessels, and examined the messenger RNA (mRNA) and protein expression of eNOS in the aorta of sedentary-young rats (sedentary-young group; 4 months old), sedentary-aged rats (sedentary-aged group; 23 months old), and swim-trained aged rats (training-aged group; 23 months old, swimming training for 8 weeks, 5 days week(-1), 90 min day(-1)). RESULTS: Body weight was significantly lower, and citrate synthase activity in the epitrochlearis muscle was significantly higher in the training-aged group compared with the sedentary-aged group. The mRNA expression of eNOS in the aorta was significantly higher in the training-aged group than in the sedentary-aged group, while it was significantly lower in both the sedentary-aged and training-aged groups than in the sedentary-young group. The expression of eNOS protein in the aorta was also significantly higher in the training-aged group than in the sedentary-aged group, while it was also significantly lower in the sedentary-aged group, but not in the training-aged group, than in the sedentary-young group. CONCLUSION: The present results revealed that the production of eNOS in the aorta decreases with ageing, and that the decreased production is increased by exercise training in aged rats, which may produce beneficial effects on the impaired cardiovascular system caused by ageing.

Aging↗
PubMed2003

Prospective randomized pilot trial of selective biliary cannulation using pancreatic guide-wire placement.

BACKGROUND AND STUDY AIMS: In difficult cases of selective bile duct cannulation, several expanded techniques are available which have only been partially evaluated in randomized studies. This study describes a prospective, randomized trial investigating a further technique for obtaining selective biliary access--pancreatic duct wire placement. PATIENTS AND METHODS: During a six-month study period, 107 consecutive patients required deep selective biliary cannulation. Accessing the bile duct using a catheter failed within 10 min in 53 of the patients, who were randomly assigned to either pre-insertion of a guide wire into the pancreatic duct or persistence with a conventional catheter. The success rate and complication rate were compared between these two groups. RESULTS: In the pancreatic duct-guide wire group (n=27), the success rate was significantly greater than in the conventional group (93% vs 58%). No pancreatitis complications occurred within either group. CONCLUSIONS: Inserting a guide wire into the pancreatic duct to facilitate deep selective bile duct cannulation is better than persisting with a conventional catheter. Further studies will be needed to confirm these results and to compare this method with other sophisticated techniques for obtaining selective access to the bile duct.

Adult↗
PubMed2003

Closed reduction of developmental dislocation of the hip by prolonged traction.

The efficacy of traction before an attempted closed reduction for patients with developmental dislocation of the hip remains controversial. We treated 55 children (62 dislocations of the hip) by preliminary, prolonged traction for a mean of eight weeks. All were followed up for at least two years in order to observe the development of any avascular changes within the femoral head. Of the 55 children, 27 (31 dislocations) were followed up until they were over six years of age. Fifty-seven of the 62 hips (92%) showed a successful closed reduction. Only one had radiological evidence of avascular necrosis of the femoral head. Of the 31 hips which were followed up to over six years of age, 15 (48%) showed residual subluxation. Our method of prolonged preliminary traction leads to a high rate of successful closed reduction, a low incidence of avascular necrosis and a reduced need for secondary operations.

Female↗
PubMed2003

[The outcome of surgical treatment and prognostic factors of pulmonary metastases; differences between carcinomas, sarcomas and germ cell tumors].

We have performed pulmonary metastasectomy on 97 patients with various malignant tumors. We analyzed the outcome of surgical treatment and prognostic factors. Survival of patients undergoing metastasectomy was significantly different according to the type of malignant tumor. The patients with carcinomas had a good survival when they had 3 years or longer disease free interval (DFI) and no other lesion except the lungs. Those with sarcomas were good survivors, who had a solitary pulmonary lesion, 1 years or longer DFI, and had no symptom originating from pulmonary metastases. Survival of patients with germ cell tumors was significantly superior to other 2 types, and factors such as an existence of extra-pulmonary metastatic lesions, respiratory symptoms and a length of DFI had no impact on the chance of their survival. These results suggest that we should decide the indication for metastasectomy on patients according to their types of malignant tumor.

Adolescent↗