Search PubMed⌕ Search

Biomedical subjects

T Maeda

Publications and source records attributed to T Maeda.

At least 127 records · Page 7Linked to original sources
PubMed2001

Alteration in the expression of heat shock protein (Hsp) 25-immunoreactivity in the dental pulp of rat molars following tooth replantation.

The regeneration process of dental pulp following tooth replantation in rat molars was investigated by immunocytochemistry for heat shock protein (Hsp) 25 and protein gene product 9.5 (PGP 9.5). In control teeth at postnatal 4 weeks, the odontoblasts showed intense Hsp 25-immunoreactivity in the coronal dental pulp, but little or no immunoreactivity in the root and floor pulp. In contrast, the Hsp 25-negative odontoblasts in the latter areas displayed immunoreactivity for PGP 9.5. Tooth replantation caused loss of Hsp 25- and PGP 9.5-immunoreactions in the dental pulp during postoperative days 1-3. At postoperative day 5, plump cells with clear nucleoli and several fine processes--presumably newly differentiated odontoblasts--at the pulp-dentin border became immunopositive for Hsp 25. These data suggest that the expression of Hsp 25- and PGP 9.5-immunoreactivity reflects the status of differentiation of the odontoblasts. Furthermore, some pulpal nerve fibers as well as the Schwann cells in the dental pulp, ordinarily negative in Hsp 25-immunoreaction, acquired their immunoreactivity by postoperative day 5, but lost it thereafter, suggesting the involvement of Hsp 25 in the regeneration of pulpal nerve fibers. In the case of bone-like tissue formation in the pulp space, on the other hand, no Hsp 25-immunoreactive odontoblasts were recognized in the pulp-dentin border. Thus, the alignment of Hsp 25-immunopositive odontoblasts along the pulp-dentin border indicates a decisive factor for inducing the reparative dentin formation after tooth replantation.

Animals↗
PubMed2001

The exact expression of glial fibrillary acidic protein (GFAP) in trigeminal ganglion and dental pulp.

The expression in various cell types of peripheral tissues of glial fibrillary acidic protein (GFAP), first discovered as an intermediate filament specific for astrocytes, remains controversial owing to numerous reports of a wide distribution for GFAP-immunoreactivity in various cells. The present study employed immunohistochemistry to investigate the precise expression of GFAP in the dental pulp and trigeminal ganglion of adult rats and wild-type mice as well as GFAP-knockout mice. The exhibition of GFAP-immunoreactivity in the trigeminal ganglion was further examined by a reverse transcription polymerase chain reaction (RT-PCR) technique, and in situ hybridization histochemistry using a specific cRNA probe prepared by us. The immunoreaction for GFAP was recognizable in the axons, Schwann cells, and the fibroblasts in the dental pulp of rats and wild-type littermate mice. However, mice with null mutations in the GFAP gene remained immunoreactive for GFAP in all these locations. Intense GFAP-immunoreactivity was found in a small number of satellite cells in the trigeminal ganglion in all animals examined in this study. RT-PCR analysis demonstrated bands for the GFAP gene corresponding to the length expected from the primer design in the samples of trigeminal ganglion and dental pulp. In situ hybridization histochemistry also showed intense signals for GFAP mRNA in some satellite cells of the trigeminal ganglion, but never in the neurons. These data suggest that the GFAP-immunoreactive molecules in the pulpal axons and fibroblasts react non-specifically with the polyclonal antibody and are probably a closely related type of intermediate filament.

Animals↗
PubMed2001

Effects of hypothermia on blood flow and neural activity in rabbit spinal cord during postischemic reperfusion.

The effects of hypothermia on blood flow and neural activity were investigated in rabbit spinal cord during the acute phase of ischemia/reperfusion. Rabbits were exposed to ischemia for 10 or 40 min by occluding the abdominal aorta, using a balloon catheter. The body temperature was maintained either at 38 degrees C (normothermia) or 34 degrees C (hypothermia). Hyperperfusion was observed within 10 min after the cessation of ischemia in all rabbits exposed to ischemia. The magnitude of hyperperfusion in spinal cord blood flow (SCBF) was not significantly different between the 10 and 40 min ischemia rabbits, but the time for 50% recovery from the hyperperfusion was longer in the 40 min ischemia group (26.1 +/- 2.5 min) than in the 10 min group (15.1 +/- 2.1 min). The amplitude of evoked spinal cord potential decreased during ischemia and recovered to the baseline level during 8 h of reperfusion in the 10 min ischemia group. However, in the 40 min ischemia group, the amplitude was 40 +/- 8% of the baseline value after 8 h of reperfusion. Hypothermia prevented the delay of recovery from hyperperfusion and the reduction of evoked spinal cord potential. These results suggest that hypothermia plays a beneficial role in protecting tissue injury in the acute phase of ischemia/reperfusion in the spinal cord by shortening the time for recovery from postischemic hyperperfusion.

Animals↗
PubMed2001

Targeted transarterial oily chemoembolization for small foci of hepatocellular carcinoma using a unified helical CT and angiography system: analysis of factors affecting local recurrence and survival rates.

OBJECTIVE: We assessed the local recurrence rate after a single targeted transarterial oily chemoembolization for small hepatocellular carcinoma with the unified helical CT and angiography system and analyzed the factors affecting the local recurrence rate and survival rate with Cox proportional hazards model. MATERIALS AND METHODS: For 54 consecutive patients with 71 small hepatocellular carcinomas (< or = 5 cm) with no more than two associated lesions, targeted oily chemoembolization was performed with an emulsion of doxorubicin hydrochloride mixed with iodized oil or a suspension of zinostatin stimalamer followed by gelatin sponge particles. When local recurrence or a new lesion appeared, follow-up targeted oily chemoembolization was performed. RESULTS: For 52 of 71 lesions, the catheterization to a subsegmental or more distal feeding artery could be performed. Local recurrence was recognized in 33.2% at 1 year and 37.8% at 2 and 3 years. The significant factors that affected local recurrence were tumor size (p = 0.005) and degree of deposition of iodized oil within the lesion (p = 0.049). The survival rates at 1, 2, and 3 years were 93.3%, 77.1%, and 77.1%, respectively. The significant factors affecting survival rate were tumor thrombus in large vessels (p = 0.0001), appearing after the first chemoembolization, and maximum tumor size (p = 0.022). CONCLUSION: Single targeted transarterial oily chemoembolization with the unified helical CT and angiography system had a low local recurrence rate for small hepatocellular carcinoma, and follow-up embolization resulted in a good survival rate. Tumor size along with degree of intratumoral iodized oil deposition and tumor thrombus along with maximum tumor size were significant factors affecting local recurrence and survival rate, respectively.

Aged↗
PubMed2001

Combinatory anti-tumor effects of electroporation-mediated chemotherapy and wild-type p53 gene transfer to human esophageal cancer cells.

Delivery of electric pulses to an established solid tumor augments the permeability of cell membrane and increases the susceptibility of tumors to an anti-cancer agent that is administered in the vicinity of tumors. Forced expression of the wild-type p53 gene in tumor cells that have non-functional p53 gene(s) can also enhance their sensitivity to a DNA-damaging agent. To investigate the feasibility of electroporation-mediated therapy for cancer, electric pulses were delivered to human esophageal tumors developed in nude mice after they received an anti-cancer agent and/or plasmid DNA containing the wild-type p53 gene. The growth of esophageal tumors was suppressed with electroporation-mediated chemotherapy compared with the treatment with an anti-cancer agent or electroporation alone. Intratumoral injection of the wild-type p53 gene into p53-mutated esophageal tumors followed by electroporation also inhibited tumor growth. When mice were administered with the wild-type p53 gene and an anti-cancer agent, subsequent electroporation produced a synergistic therapeutic effect. Combinatory transfer of plasmid DNA and a pharmacological agent by electroporation is thereby a possible therapeutic strategy for the treatment of solid tumors.

Animals↗
PubMed2001

Monitoring of chicken houses and an attached egg-processing facility in a laying farm for Salmonella contamination between 1994 and 1998.

Two chicken houses and an attached egg-processing facility in a laying farm were sampled between 1994 and 1998 to investigate Salmonella contamination. Each of the houses was environmentally controlled and fitted with egg belts that transported eggs from the houses to the egg-processing facility. Four hundred twenty-eight Salmonella isolates were obtained from 904 environmental samples collected from the houses. Two hundred fifty-two of the 428 (58.9%) isolates yielded five serotypes as follows: Salmonella enterica subsp. enterica serovar Livingstone, Salmonella serovar Cerro, Salmonella serovar Montevideo, Salmonella serovar Mbandaka, and Salmonella serovar Corvallis. The remaining (41.1%, 176 of 428) isolates included four other serotypes and isolates that were untypeable. Salmonella isolates obtained from the drain water collected after the washing of the eggs in the egg-processing facility yielded the same serotypes as those found in the chicken houses. Strains having an identical pulsed-field gel electrophoresis (PFGE) pattern were continually recovered from a house for more than 1 year. Several strains of Salmonella Cerro, Salmonella Mbandaka, and Salmonella Montevideo obtained from both the houses and from the egg-processing facility were indistinguishable by PFGE, respectively. These results suggest that Salmonella organisms originating from a single clone colonized the chicken houses and that the egg belts are likely to be one of the means by which Salmonella organisms are spread from one house to the others.

Animal Husbandry↗
PubMed2001

Mechanisms of photoreceptor cell death in cancer-associated retinopathy.

PURPOSE: In a previous study, both recoverin and heat shock cognate protein (hsc) 70 were recognized as autoantigens by sera from patients with cancer-associated retinopathy (CAR), and retinal dysfunction similar to CAR was inducible by intravitreous injection of anti-recoverin and anti-hsc 70 antibodies to Lewis rat. The purpose of the present study was to elucidate the effects of these antibodies on retinal photoreceptor cell functions, the contribution of caspase during the photoreceptor degeneration, and the roles of aberrant expression of recoverin in tumor cells. METHODS: As photoreceptor functions, rhodopsin phosphorylation using freshly prepared rod outer segments (ROS) and electroretinogram (ERG) were studied. Expression of recoverin in several kinds of tumors was examined by reverse transcription-polymerase chain reaction and Western blot analysis. The effects of recoverin on calcium-dependent protein phosphorylation were studied using the A549 lung adenocarcinoma cell line, which does not express recoverin. RESULTS: Rhodopsin phosphorylation in bovine ROS was significantly promoted by the addition of anti-recoverin antibody. Similar effects on rhodopsin phosphorylation and ERG impairment were observed in rat eyes treated with anti-recoverin antibody. Co-injection of caspase inhibitors with anti-recoverin antibody inhibited ERG impairment and significantly suppressed the antibody-induced enhancement of rhodopsin phosphorylation. Aberrant expression of recoverin was found in 15 of 30 tumor tissues from patients with cancer without CAR. Profiles of calcium-dependent protein phosphorylation of cell lysate from A549 cells were modulated by the presence of purified recoverin. CONCLUSIONS: These observations suggest that anti-recoverin antibody is incorporated into rod photoreceptor cells and modulates rhodopsin phosphorylation, which in turn produces activation of caspase-dependent apoptotic pathways. Regarding antibody generation in CAR, a high incidence of aberrant expression of recoverin in cancer tissues is important, as suggested previously.

Animals↗
PubMed2001

Vascular endothelial growth factor and cellular chemotaxis: a possible autocrine pathway in adult T-cell leukemia cell invasion.

Our previous report (T. Hayashibara et al., Leukemia, 13: 1634-1635, 1999) revealed a possible link between high plasma vascular endothelial growth factor (VEGF) concentration and leukemic cell invasion in adult T-cell leukemia (ATL). However, the biological mechanism of this link has not been elucidated. The purpose of this study was to address that mechanism. Our present observations showed that VEGF mRNA was expressed in ATL cell lines. The corresponding protein was secreted into the extracellular environment, which suggested that the major source of plasma VEGF is ATL cells themselves. More interestingly, all of the cell lines examined were found to express the mRNA and protein for fms-like tyrosine kinase-1 (Flt-1), which is one of the receptors for VEGF. Cytofluorometric analysis demonstrated the VEGF binding potency of these cells. In clinical specimens, expression of VEGF and Flt-1 mRNAs was detected in all (100%) of 11 and 8 (73%) of 11 ATL patients, respectively. Cytofluorometric analysis revealed that VEGF effectively bound only to Flt-1-expressing cells. These findings are highly suggestive of an autocrine pathway involving VEGF operating in ATL. The proliferation of ATL cell lines was not affected by treatment with an anti-VEGF antibody or exogenous VEGF, which indicated that VEGF has no mitogenic effect on ATL cells. In contrast, we made the interesting finding that treatment with exogenous VEGF enhanced the chemotactic activities of some ATL cell lines, which may play a key role in ATL cell invasion. Collectively, these data lead us to propose a possible autocrine mechanism involving VEGF operating by way of Flt-1, in which ATL cells up-regulate their own chemotaxis to facilitate their invasion into various organs.

Adult↗
PubMed2001

Standardized multicolored magnetic resonance images of gynecologic lesions.

PURPOSE: The purpose of this study was to develop a convenient and simple method for visualizing in color the features of gynecologic lesions by combining T1- and T2-weighted magnetic resonance images using RGB (red-green-blue) color channels. MATERIALS AND METHODS: T1- and T2-weighted film images of gynecologic lesions were digitized using a film-scanner. The signal intensities of fat on T1-weighted images were converted to 133% of those on T2-weighted images. Additive multicolored images in the RGB color system were produced from T1- and T2-weighted images using color axes of a complementary color pair for a total of 84 typical gynecological lesions. RESULTS: Tissues were displayed in color as follows: fat: light tan; urine: light blue: muscle: dark brown; endometrium: light blue; leiomyomas with cystic degeneration: cyanblue; cellular leiomyoma: yellowish brown; endometrial cyst: orange. The images of female intrapelvic structures and gynecologic lesions were semi-natural in appearance. CONCLUSION: Standardization of fat intensities provides a simple method for multicolored visualization of the features of gynecologic lesions.

Color↗
PubMed2001

[Distribution of 5'-nucleotidase activity in greater omentum of rats].

The aim of the present study is to demonstrate the cellular basis of 5'-nucleotidase (5'-Nase) activity in the greater omentum of rats. Enzyme histochemistry for 5'-Nase showed that lymphatic vessels in the omentum as well as lymphocytes in the milky spots were positively stained. Electron microscopic observation revealed-5'-Nase activity at the luminal surface of the lymphatic endothelial cells, pinocytotic vesicles in the endothelial cells and the surface of fibroblasts located at the intercellular space of adipose cells. Fibroblasts extended long cytoplasmic processes toward adipose cells and inflammatory cells. These findings suggest that lymphatic endothelial cells as well as fibroblasts in the omentum may play an important role in regulation of metabolism and immune mechanisms in the greater omentum by supplying adenosin.

5'-Nucleotidase↗
PubMed2001

Retinal dysfunction in cancer-associated retinopathy is improved by Ca(2+) antagonist administration and dark adaptation.

PURPOSE: It was recently found that recoverin acts as an autoantigen recognized by sera of patients with cancer-associated retinopathy (CAR), and that CAR-like retinal dysfunction is produced by intravitreous administration of anti-recoverin antibody in Lewis rat eyes. To examine the pathologic molecular mechanism of CAR, and to elucidate an effective therapy for CAR, the function and morphology of CAR were compared with those of phototoxic retinal damage, another form of photoreceptor dysfunction, and the effect of nilvadipine, a Ca(2+) antagonist, on the retinal degenerations was studied, using these models. METHODS: Under different illumination conditions and/or medication with nilvadipine, the functional and morphologic properties of the retinas were evaluated after intravitreous injection of anti-recoverin antibody into Lewis rat eyes (six rats, 12 eyes in each experimental condition), using electroretinogram (ERG), rhodopsin phosphorylation, and light microscopy. RESULTS: Anti-recoverin antibody administered into the vitreous of Lewis rat eyes induced a significant decrease and increase of ERG responses and rhodopsin phosphorylation levels, respectively, under cyclic or continuous light. Similar changes were observed in eyes of rats bred under continuous illumination that did not receive anti-recoverin antibodies. However, anti-recoverin antibody-induced retinal dysfunctions were not observed in rat eyes under dark conditions. Administration of nilvadipine, a Ca(2+) antagonist, to the anti-recoverin antibody-treated rats and rats with phototoxic retinal dysfunction caused significant improvement of the deterioration of ERG and normalization of rhodopsin phosphorylation. CONCLUSIONS: The present data indicate that anti-recoverin antibody-induced retinal dysfunction was functionally similar to phototoxic retinal dysfunction and was markedly suppressed under dark conditions or by systemic administration of a Ca(2+) antagonist.

Animals↗
PubMed2001

[A promising new treatment strategy for advanced hepatocellular carcinoma--"multi-ablation therapy" consisting of radio-frequency ablation (RFA), microwave coagulation therapy (MCT) and ethanol injection therapy (EIT)].

We introduce a new treatment strategy (multi-ablation therapy) for advanced hepatocellular carcinoma (HCC). The therapy consists of radio-frequency ablation (RFA), microwave coagulation therapy (MCT) and ethanol injection therapy (EIT). We assessed the efficacy of the therapy in 20 patients with advanced HCCs, including 10 patients with stage III and 10 patients with stage IV. The average tumor diameter was 3.6 cm (max: 6.6 cm) and the average tumor number was 3.6 (max: 11). RFA, MCT and EIT were performed in 20, 14 and 9 cases, respectively. A percutaneous, endoscopic and open approach was applied in 2, 11 and 7 cases, respectively. The average number of times treated on initial admission was 1.1. The response rate, calculated by the tumor necrosis effect, was 100%. The cumulative two-year recurrent rate in the treated sites was 33% and the 2-year cumulative survival rate was 90%. Complications were encountered in two patients (liver failure and pyothorax). Multi-ablation therapy provides an excellent prognosis for advanced HCC patients whose condition could not be controlled with conventional therapeutic modalities.

Carcinoma, Hepatocellular↗
PubMed2001

[Orchiectomy for tuberculous epididymitis: a report of two cases with intractable to antituberculosis treatment].

This paper describes two cases with tuberculous epididymitis. The first case was a 69-year-old man who was admitted to our hospital because of ulceration or right scrotum. Physical examination revealed a hard, rounded, a little bigger than egg-sized mass in the right scrotum. The second case was a 40-year-old man who was admitted to our hospital because of cough, fever and body weight loss. He was treated for pulmonary tuberculosis with isoniazid, rifampicin, streptomycin and pyrazinamide. Six months after admission, he complained of a painless swelling of the right scrotum. Physical examination revealed a hard, rounded, more than egg-sized mass in the right scrotum. Right orchiectomy was performed in these two cases, and they were cured.

Adult↗
PubMed2001

Identification of missense mutation (G365R) of the butyrylcholinesterase (BCHE) gene in a Japanese patient with familial cholinesterasemia.

A point mutation which caused a silent phenotype of human serum butyrylcholinesterase (BChE) was identified in the genomic DNA of a 57-year-old Japanese woman who visited our hospital because of pneumonia. The propositus exhibited an unusually low level of BChE activity, whereas her son and daughter had an intermediate level. Immunologically, there was an absence of BChE protein in the propositus's serum. DNA sequence analysis of the propositus demonstrated a point mutation at codon 365 (GGA-CGA), resulting in a Gly-Arg substitution. A family study showed her son and daughter to have the same mutation.

Butyrylcholinesterase↗
PubMed2001

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents. Special references to bacteria isolated between April 1998 and March 1999].

The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in Japan since July 1982. This paper describes the results obtained in fiscal 1998 (from April 1998 to March 1999). The number of cases investigated as objectives was 225 for one year. A total of 429 strains (121 strains from primary infections and 308 strains from postoperative infections) were isolated from 183 cases (81.3% of total cases). In primary infections, the isolation rates of anaerobes and Escherichia coli were higher than in postoperative infections, while in postoperative infections, those of Gram-positive aerobes and Pseudomonas aeruginosa were higher than in primary infections. On the whole, among Gram-positive aerobes, the isolation rate of Enterococcus faecalis was the highest, followed by Staphylococcus aureus with high frequency in isolation from postoperative infections. Among Gram-positive anaerobes, Peptostreptococcus spp. and Streptococcus spp. were predominantly isolated. Among Gram-negative aerobes, E. coli, P. aeruginosa, Klebsiella pneumoniae and Enterobacter cloacae were frequently isolated. Among Gram-negative anaerobes, Bacteroides fragilis group was the majority of isolates. In primary infections, the percentage of Gram-negative aerobes has gradually increased since fiscal 1995 or 1996 with these years as the turning point, while those of Gram-positive and Gram-negative anaerobes have gradually declined. In postoperative infections, the percentage of Gram-negative anaerobes has increased continuously since the mid-1980s. The percentage of MRSA among S. aureus rose to 89.7%, which was the highest level since the beginning of this study. The susceptibilities of B. fragilis, which did not show apparent changes, were recognized to have decreased against cephems in fiscal 1998. Among other bacteria in B. fragilis group, development of resistance to cephems has continued on a long-term basis since the mid-1980s. E. coli and K. pneuminiae have obviously not changed in susceptibilities, however, the susceptibilities of isolated strains in fiscal 1998 against high-generation cephems, oxacephems and monobactams have declined. We found neither vancomycin-resistant nor teicoplanin-resistant strains of S. aureus and Enterococcus spp.

Anti-Bacterial Agents↗
PubMed2001

Prognostic significance of apoptosis in squamous cell carcinoma of oral cavity with special reference to TNM stage, histological grade and survival.

Apoptotic count was assessed in 38 cases of squamous cell carcinoma of oral cavity by light microscopy and correlated with TNM stage, histological grade and survival. A direct correlation with the TNM stage (p = 0.0166) and an inverse correlation with the histological grade (p = 0.03) was found, however no correlation was found with the survival. Apoptotic count was significantly different between well and moderately differentiated carcinoma (p = 0.347) and well and poorly differentiated carcinoma (p = 0.0190). Thus apoptotic count may have prognostic value particularly in combination with staging and histological grade.

Adult↗