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Biomedical subjects

T Hamada

Publications and source records attributed to T Hamada.

At least 19 recordsLinked to original sources
PubMed2007

Manipulation of cell-sized phospholipid-coated microdroplets and their use as biochemical microreactors.

Cell-sized water droplets coated by a phospholipid layer mimicking the inner surface of living cells were manipulated by laser tweezers and used as biochemical microreactors. The cell-sized phospholipid-coated microdroplets (CPMDs) consisted of a water droplet in mineral oil with a diameter of 1-100 microm and coated by 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine. We monitored the time development of biochemical reactions in a single CPMD obtained after the controlled fusion of two CPMDs containing a substrate and an enzyme, respectively. We present results on two enzymatic reactions: calcein production in the presence of esterase and green fluorescence protein expression.

Biochemistry↗
PubMed2006

Risk factors for nausea and vomiting following vitrectomy in adults.

BACKGROUND AND OBJECTIVE: Postoperative nausea and vomiting (PONV) after ophthalmic surgery under general anaesthesia remains a complex and perturbing complication associated with several factors. Little information is available regarding the risk factors for nausea and vomiting after vitrectomy in adults. In this study, we evaluated the potential risk factors for PONV after vitrectomy in adult patients. METHODS: Univariate and multivariate analyses of clinical factors associated with PONV were undertaken in a retrospective case-control series of 247 adult patients undergoing vitrectomy under general anaesthesia. We examined PONV for the first 48 h. Factors examined were age, body mass index (BMI), smoking status, H2-blocker as premedication, type of general anaesthesia (sevoflurane and fentanyl or total intravenous (i.v.) anaesthesia with propofol and fentanyl), duration of surgery, and intraoperative fentanyl dose. RESULTS: Fifty-nine patients (24%) reported one or more episodes of PONV during the study period. Female gender (P < 0.01), lower BMI (P < 0.01) and general anaesthesia with inhalational anaesthetics (P < 0.01) were significantly related to nausea during the first 2 h postoperatively. Female gender (P < 0.01) was significantly related to nausea and vomiting throughout the study period. Other factors, including smoking status, did not alter the risk for nausea and/or vomiting. CONCLUSIONS: We conclude that female gender, lower BMI and inhalation anaesthesia are the main risk factors for PONV after vitrectomy in adults. Smoking status did not reduce the incidence of PONV in our patients.

Adolescent↗
PubMed2006

Optimal depth of insertion of left-sided double-lumen endobronchial tubes cannot be predicted from body height in below average-sized adult patients.

BACKGROUND AND OBJECTIVE: The optimal depth of insertion of left-sided double-lumen endobronchial tubes is strongly correlated with body height in average-sized adults. However, this relationship has not been studied in below average-sized adult patients. We investigated whether or not there is a clinically useful relationship in below average-sized adult patients. METHODS: One hundred and ninety six consecutive adult patients undergoing thoracic surgery under one-lung anaesthesia (body height < or = 155 cm) were included in this study. Left-sided double-lumen tubes were inserted under the guidance of a fibre-optic bronchoscope. Optimal depth was defined as the proximal surface of the bronchial cuff positioned just below the carina. RESULTS: There was a statistically significant positive correlation between body height and the optimal depth of insertion (r = 0.61, P < 0.0001); however, the correlation coefficient was low. The actual optimal depth of insertion of one patient was even 4.5 cm shorter than that obtained from the equation. CONCLUSION: Although there was a statistically significant correlation between body height and the optimal depth of insertion of left sided double lumen tubes in adult patients of short stature (< or = 155 cm), clinical application of the equation is not warranted and these tubes should be inserted under direct vision with a fibre-optic bronchoscope.

Aged↗
PubMed2006

The effect of saliva or serum on bacterial and Candida albicans colonization on type I collagen.

Colonization of Candida albicans on oral surfaces can serve as a reservoir for disseminated infections, such as aspiration pneumonia and gastrointestinal infection, particularly in the immunocompromised host. Therefore, the aim of this study was to investigate the effects of salivary and serum pellicles on C. albicans, Streptococcus mutans, S. sanguis, Lactobacillus and Actinomyces colonization on type I collagen, a major organic component of periodontal ligaments. The colonization potential of two isolates each of C. albicans, S. mutans and S. sanguis, and a single isolate each of Lactobacillus and Actinomyces to uncoated (control), saliva-coated or serum-coated type I collagen plates (surface area 143 mm(2), Cell Disk; Sumitomo, Tokyo, Japan) was examined using a bioluminescent adenosine triphosphate assay based on firefly luciferase-luciferin system. The results revealed that with mutans streptococci, a saliva pellicle was significantly more effective in promoting bacterial colonization compared with the pellicle-free collagen disc, and the serum-coated sample significantly inhibited the colonization of streptococci (anova; P < 0b01). In contrast, in the case of C. albicans, Lactobacillus and Actinomyces isolates, a serum pellicle was significantly more effective in promoting the colonization, followed by saliva pellicle and uncoated specimen (anova; P < 0b01). These results suggested that crevicular fluid rich in seruminous components would promote the colonization of Candida, Lactobacillus and Actinomyces on type I collagen as opposed to streptococci which showed greater avidity to saliva-coated collagen.

Actinomyces↗
PubMed2006

Prognostic significance of subcarinal station in non-small cell lung cancer with T1-3 N2 disease.

BACKGROUND: Surgical resection may continue to offer the best chance of long-term survival for patients with non-small cell lung cancer (NSCLC). Generally, patients with N2 NSCLC have a poor prognosis. However, the surgical treatment of patients with N2 remains controversial as in these patients, some N2 subgroups have better prognoses than others. The objective of the current study was to evaluate the factors associated with N2, and to determine whether such factors are reliable predictors of survival. METHODS: We retrospectively reviewed 142 non-small cell lung cancer patients with T1-3 N2 in whom a curative approach had been attempted between January 1994 and December 2003. The patients were consequently divided into four groups (NS-1, no subcarinal involvement and without N1; NS-2, no subcarinal involvement and with N1; SI-1, subcarinal involvement and without upper mediastinal site; SI-2, subcarinal involvement and with upper mediastinal site). We also evaluated two groups for N2 stations (single-station N2 versus multiple-station N2). Multivariate analysis by Cox's proportional hazards regression model was performed to identify the prognosis. RESULTS: Lobectomy was carried out in 105 of the patients; bilobectomy in 10, and pneumonectomy in 27. The patients with T1-3 N2 disease showed survival rates of 34.1 % at 3 years and 24.1 % at 5 years. The overall survival rates at 3 years and 5 years were as follows: NS-1, 56.3 % and 43.2 %; NS-2, 35.4 % and 29.5 %; SI-1, 16.7 % and 0 %; SI-2, 15.4 % and 0 %, respectively. The NS-1 group had better prognoses than the other groups. There was a significant difference in survival rates within each group ( p = 0.0005). In univariate analysis, the type of surgery, type of subcarinal involvement, and multiple-station N2 were significantly associated with prognosis. Multivariate analysis showed that NS-1 was only found to be an independent prognostic factor in cases of T1-3 N2 disease ( p = 0.0018). NS-2 was not an independent factor but tended toward significance ( p = 0.0681). But multiple-station N2 was not an independent factor ( p = 0.1549). CONCLUSIONS: Surgery for patients with T1-3 N2 NSCLC might be acceptable if subcarinal lymph node metastasis is predicted to be absent.

Adenocarcinoma↗
PubMed2006

The value of tumor volume in surgically resected non-small cell lung cancer.

BACKGROUND: The aim of this study was to evaluate whether or not tumor volume (TV) has an impact on survival in non-small cell lung cancer. METHODS: In a retrospective analysis of 385 cases with NSCLC who underwent curative surgery between 1994 and 2003, we calculated the tumor volume by using an ellipsoidal formula. The patients were grouped according to TV as determined by histograms. Gender, age, histology, nodal involvement, size, and TV were analyzed. Multivariate analysis by Cox's proportional hazards regression model was performed to identify the prognosis. RESULTS: Cases of N0 showed a significantly lower TV than cases with other N statuses (p < 0.05). A significant difference was also observed between TV and histology or gender. The 189 patients belonging to the small volume group (SVG) (range, 0.105 to 9.265 cm3) had a significantly better overall survival rate than the other 196 patients in the large volume group (LVG) (9.266-366.522 cm3). With univariate analysis, gender, age, nodal involvement, size, and TV were significantly associated with prognosis. Multivariate analysis showed that only gender (p = 0.0184) and nodal involvement (p = 0.0001) were significantly independent prognostic factors. The size factor was not significant (p = 0.5285). However, TV was not an independent factor, but trending toward significance (p = 0.0801). CONCLUSIONS: Although TV provides no independent prognostic information with multivariate analysis, TV in NSCLC should be considered using volumetric measurement with a three-dimensional CT approach prior to surgery or treatment planning.

Aged↗
PubMed2006

Less vigorous surgery for second primary lung cancer.

BACKGROUND: Patients with second primary lung cancer (SPLC) have a heterogeneous background. The optimum modality of treatment for SPLC patients has not yet been determined. The objective of this study was to attempt to identify the value of less vigorous therapies such as segmentectomy or video-assisted thoracic surgery (VATS) in SPLC. METHODS: We retrospectively reviewed the medical records of 46 patients who underwent resection for SPLC in Fukuoka University Hospital between January 1994 and April 2005. Patients were separated into two groups (LVT: less vigorous therapy including segmentectomy or VATS lobectomy; LCT: lobectomy with conventional thoracotomy). The characteristics of each group were evaluated and survival rates were analyzed at 5 years after surgery. RESULTS: The mean amount of blood loss was found to be significantly different ( P = 0.0062) with 59.44 +/- 14.00 ml for LVT cases and 254.48 +/- 63.62 ml for LCT. None of the LVT patients experienced postoperative complications. The 5-year survival rate was 62.7 % for LVT and 57.7 % for LCT. There was no significant difference in survival rates between these groups. CONCLUSIONS: Although differences were seen in the characteristics, less invasive surgery such as VATS or segmentectomy may be a feasible treatment for SPLC.

Aged↗
PubMed2006

An in vitro evaluation of the adhesion of Candida species to oral and lung tissue cells.

The analysis of the adherence capacity of fungi to surfaces of both oral tissue and different tissues would be of interest in the fungal dissemination as an oral and systemic pathogen. We developed an in vitro adenosine triphosphate (ATP)-based assay technique to extract the cellular and fungal ATP separately, which allowed the quantitative evaluation of the adhesion of the yeast to monolayers of human gingival epithelial cells (GEC), gingival fibroblasts (GF) and pulmonary fibroblasts (PF). Seven oral isolates of Candida species (three of Candida albicans, three of Candida tropicalis and one of Candida glabrata) were used in the study. The adherent level of the Candida species varied depending on both the isolates and the cell origins, although all the Candida isolates had a significantly higher level of adherence to GEC than to GF except the single isolate of C. tropicalis. Whereas the adherent level of the five isolates to GEC was significantly higher than that to PF, the adherent level of the remaining two isolates of C. tropicalis to GEC was significantly lower than that to PF. These results suggest that candidal adherence to host tissue cells should be regulated in an isolate-dependent and cell-origin-dependent manner, and that the phenomena may be involved in the colonisation and/or dissemination of the fungi.

Candida↗
PubMed2006

Morules and morule-like features associated with carcinomas in various organs: report with immunohistochemical and molecular studies.

BACKGROUND: Morules have been reported in pulmonary blastoma (PB), well differentiated fetal adenocarcinoma of the lung (WDFA), and uterine endometrioid carcinoma (EC), and rarely in other carcinomas. beta Catenin gene mutation has been associated with morule formation. AIMS: To compare and clarify the cellular characteristics of morules in carcinomas in various organs and show that morules are distinct from epithelial cellular nodules. METHODS: Twenty tumours were studied: two PBs, three WDFAs, three papillary lung adenocarcinomas, 11 ECs, and one papillary thyroid carcinoma. Numerous epithelial cell, oncofetal, and neuropeptide antibodies were used for immunohistochemistry. beta Catenin gene mutation was investigated. RESULTS: Morules in PBs and ECs were uniform cell clusters distinct from squamous differentiation. All were immunonegative for epithelial cell and oncofetal antigens, but those in ECs were positive for neurone specific enolase gamma (NSEgamma). Synaptophysin, encephalin, and somatostatin were sporadically immunopositive in PB morules. Morules were not seen in the other carcinomas and WDFAs, although morule-like features closely resembling morules histopathologically were seen. These were positive for epithelial cell and oncofetal antigens, and showed squamous differentiation. Their nuclei were more atypical and slightly larger than those in morules. Morule-like features were seen in WDFAs. beta Catenin gene mutation was demonstrated in one EC and PB, and in two WDFAs. CONCLUSION: Morules were non-epithelial cell clusters showing neuronal differentiation. There were two types: endometrioid type, expressing NSEgamma, and blastoma type, expressing neuropeptides. In contrast, similar morule-like features were epithelial nodules. Although the number of cases was small, the presence of morules showed no clear prognostic correlations.

Adenocarcinoma↗
PubMed2006

HLA-dPB1*0501 is not uniquely associated with opticospinal multiple sclerosis in Japanese patients. Important role of DPB1*0301.

Apart from its unique lesion distribution pattern, the opticospinal form of multiple sclerosis (OSMS) is distinct among Japanese patients who satisfy the diagnostic criteria of MS. OSMS has been suggested to be strongly associated with HLA-DPB1*0501 in Japanese. However, association of DPB1*0301 with non-OSMS and lack of DPB1*0301 in OSMS were also reported. To verify the role of DPB1*0501 and DPB1*0301 in Japanese MS patients we determined the frequencies of these alleles in 26 patients with OSMS, 167 with non-OSMS and 156 normal subjects, who were all residents of Hokkaido, the northernmost island of Japan. All (100%) OSMS were negative for DPB1*0301 while 32 (19%) of the non-OSMS were positive for the allele. In DPB1*0301-negatives, the frequencies of DPB1*0501 in OSMS (85%) and non-OSMS (82%) were similar, but both were higher than in the controls (66%). In DPB1*0301-positives, the frequency of DPB1*0501 was low but similar in non-OSMS (12/32; 38%) and controls (6/14; 43%). Periventricular white matter lesions (PVL) were noted in 31 of 32 (97%) DPB1*0301-positive non-OSMS patients but in only 22 out of 135 (16%) DPB1*0301-negative non-OSMS patients and two out of 26 (8%) OSMS patients. Our findings indicate that DPB1*0501 plays an important role in the development of MS in general, but not in OSMS. The strong association of DPB1*0501 with OSMS may be due to the over-representation of the DPB1*0301 allele among individuals in the non-OSMS group. In addition, DPB1*0301 might be relevant to the development of periventricular lesions in Japanese patients with MS.

Adult↗
PubMed2005

Characteristic differences between patients who have undergone surgical treatment for lung metastasis or hepatic metastasis from colorectal cancer.

OBJECTIVE: The characteristic differences between patients with lung or liver metastases from colorectal carcinoma (CRC) have not yet been clarified. A small group of these patients demonstrate a better prognosis, and the selection criteria for resection of liver and/or lung metastasis are not well defined. It is important to compare and analyze the most common metastatic sites, which include liver metastases and lung metastases. The objective of this study was to compare the characteristics of the two groups in order to identify patients who benefitted from surgical resection of CRC. METHODS: We retrospectively reviewed the medical charts of 80 patients who had undergone resection for liver or lung metastasis from CRC in Fukuoka University Hospital between June 1991 and December 2004. These patients were grouped according to surgical therapy received for the metastases, and separated into two groups, as follows: LUM, lung metastases resection; LIM, liver metastases resection. We evaluated these groups for a set of several factors. RESULTS: The characteristic factors between the two groups (LUM vs. LIM) demonstrated significant differences according to histological differentiation, venous invasion, and lymphatic permeation. There was a statistical difference in the disease-free interval (DFI) between the two groups (947.06 +/- 840.39 days in LUM vs. 246.03 +/- 229.26 days in LIM). Although serum CEA levels at resection of metastasis showed significant differences between the groups (LUM, 13.25 +/- 31.55 ng/ml; LIM, 55.21 +/- 99.52 ng/ml), the primary serum CEA levels were not significantly different. Overall survival rates at 5 years were 37.0 % for LUM and 42.8 % for LIM. There was no significant difference in the survival rate of the LUM vs. the LIM group after resection of metastasis. The Cox proportional hazards regression model was used to determine serum CEA status at the time of the metastases and showed a significant difference indicating poor prognosis for patients with LUM, but the results were not significant for LIM cases. CONCLUSIONS: Candidates for surgical treatment for lung or liver metastases from CRC may be an acceptable for the same valuable approach, even if characteristic differences were observed in each group.

Carcinoembryonic Antigen↗
PubMed2005

MUC4 expression is a novel prognostic factor in patients with invasive ductal carcinoma of the pancreas.

BACKGROUND: Many patients with invasive ductal carcinoma of the pancreas (IDC) have a poor outcome. MUC4 expression has been implicated as a marker for diagnosis and progression of IDC, but there are no studies of the relation between MUC4 expression and patient prognosis in IDC. AIMS: To investigate the prognostic significance of MUC4 expression in IDC. METHODS: The expression profiles of MUC4, ErbB2, p27, and MUC1 were investigated in IDC tissues from 135 patients by means of immunohistochemistry. RESULTS: MUC4 was expressed in 43 of the 135 patients with IDC (31.9%). The survival of 21 patients with high MUC4 expression (>20% of neoplastic cells stained) was significantly worse than that of the 114 patients with low MUC4 expression (<20% of neoplastic cells stained) (p = 0.0043). Univariate analysis showed that high MUC4 expression (p = 0.0061), large primary tumour status (>T2) (p = 0.0436), distant metastasis (p = 0.0383), lymphatic invasion (p = 0.0243), and surgical margins (p = 0.0333) were significant risk factors affecting the outcome of patients with IDC. Backward stepwise multivariate analysis showed that MUC4 expression (p = 0.0121), lymph node metastasis (p = 0.0245), and lymphatic invasion (p = 0.0239) were significant independent risk factors. ErbB2, p27, and MUC1 were not independent risk factors. CONCLUSIONS: This study shows that MUC4 expression in IDC is a new independent factor for poor prognosis and predicts the outcome of patients with IDC.

Adult↗
PubMed2005

Viscoelasticity of dental tissue conditioners during the sol-gel transition.

Formation of tissue conditioners is a process of polymer chain entanglements. This study evaluated the influence of composition and structure on dynamic viscoelasticity of concentrated polymer solutions based on poly(ethyl methacrylate) (PEMA) used as tissue conditioners through the sol-gel transition. The hypothesis was that the ethanol content is the most influential factor in determining gelation speed. Rheological parameters were determined with the use of a controlled-stress rheometer. Analysis of variance by orthogonal array L(16)(4(5)) indicated that the strong polar bonding of ethanol (contribution ratio rho = 53.8%; confirming the hypothesis) and molecular weight of polymer powders (rho = 26.7%) had a greater influence on the gelation times of PEMA-based systems than did the molar volume of plasticizers (rho = 9.0%) and concentration of polymers (i.e., powder/liquid ratio) (rho = 4.5%). The results suggest that the gelation of tissue conditioners based on PEMA can be controlled over a wide range by varying the polymer molecular weight, and especially ethanol content.

Analysis of Variance↗
PubMed2005

Clock gene expression in the submandibular glands.

Clock genes, which mediate molecular circadian rhythms, are expressed in a circadian fashion in the suprachiasmatic nucleus and in various peripheral tissues. To establish a molecular basis for circadian regulation in the salivary glands, we examined expression profiles of clock-related genes and salivary gland-characteristic genes. Clock-related genes-including Per1, Per2, Cry1, Bmal1, Dec1, Dec2, Dbp, and Reverbalpha-showed robust circadian expression rhythms in the submandibular glands in 12:12-hour light-dark conditions. In addition, a robust circadian rhythm was observed in amylase 1 mRNA levels, whereas the expression of other salivary-gland-characteristic genes examined was not rhythmic. The Clock mutation resulted in increased or decreased mRNA levels of Per2, Bmal1, Dec1, Dec2, and Dbp, and in Cry1-/- background, Cry2 disruption also increased or decreased mRNA levels of these clock-related genes and the amylase 1 gene. These findings indicate that the Clock- and Cry-dependent molecular clock system is active in the salivary glands.

ARNTL Transcription Factors↗
PubMed2004

Generalized dystonia and striatal calcifications with lipoid proteinosis.

Lipoid proteinosis (LP) is an autosomal recessive disease that typically presents with papular, verrucous, poxlike, or acneiform scars and lesions and hoarseness. LP was recently mapped to the 1q21 locus and shown to result from mutations in the extracellular matrix protein 1 gene (ECM1). Epilepsy, mental retardation, and hippocampal calcifications can occur. The authors describe a patient with generalized dystonia caused by striatal calcifications.

Adult↗
PubMed2004

Lactobacillus reuteri in bovine milk fermented decreases the oral carriage of mutans streptococci.

The effect of Lactobacillus reuteri against one of the major cariogenic organism, Streptococcus mutans, was studied. Yogurt products containing L.reuteri showed a significant growth inhibitory effect against S. mutans, whilst yoghurts with lactobaccilli other than L. reuteri did not show such inhibition. Further, double-blind, placebo-controlled trial demonstrated that consuming yogurt with L. reuteri significantly reduced the oral carriage of mutans streptococci, compared with the placebo yogurt.

Animals↗
PubMed2004

Evaluation of an embedded polar C4 phase for hydrophobic protein analysis by reversed-phase liquid chromatography.

A C4 column (InertsilWP300 C4) was developed for a protein analysis in reversed-phase chromatography. Polar groups were embedded on this phase. And this column was evaluated with low concentration of trifluoroacetic acid (TFA) and formic acid. Test C4 phases that controlled carbon loading and commercially available columns were compared with this embedded C4 column. The test column with higher carbon loading showed good separations of proteins at low concentrations of TFA, although hydrophobic proteins were broadened. On the other hand, embedded polar C4 packings showed ideal retention behavior for proteins, which is independent of ion-pairing effects of additives in mobile phase. The reason was concluded to be the shielding effects of polar groups on the sorbents, which reduce silanophilic interactions with polar groups of proteins.

Chromatography, High Pressure Liquid↗