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Biomedical subjects

S Maeda

Publications and source records attributed to S Maeda.

At least 235 records · Page 13Linked to original sources
PubMed1999

Sequence analysis and expression of Nramp-1 gene in Bcgr and Bcgs mice.

Nucleic acid sequence of complemental DNA open reading frame for Nramp-1 gene was compared among DBA/2 (Bcgr), C57BL/6 (Bcgs) and C57BL/6-Bcgr mice which was previously developed as M. avium-resistant mouse strain (Xu, et al. Veterinary Microbiology 50:73-79 (1996). Total RNA was isolated from various organs of DBA/2, C57BL/6 and C57BL/6-Bcgr. Nramp-1 cDNA was constructed from their mRNAs by gene amplification (PCR) technique and their open reading frame sequences were compared. The results clearly showed that our C57BL/6-Bcgr was almost identical with the DNA sequence of the DBA/2 mice. In contrast, C57BL/6-Bcgs mice differed only on the substitution of adenine for guanine of the nucleic acid at position 596. This corresponded to the site of amino acid substitution (glycine to asparate) at position 169 in predicted NRAMP which had been reported. The expression of Nramp-1 mRNA was more prominent in spleens and livers and there appeared to be no significant difference among the strains of mice.

Animals↗
PubMed1999

Human retinoic X receptor beta: complete genomic sequence and mutation search for ossification of posterior longitudinal ligament of the spine.

Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by ectopic bone formation in the ligament. OPLL is a very common disorder, in fact it constitutes the leading cause of myelopathy among Japanese. In the previous report, we provided the genetic linkage evidence that the genetic susceptibility of OPLL mapped to HLA complex of chromosome 6. As a candidate gene approach, retinoic X receptor beta (RXR beta), assigned to chromosome 6p21.3 adjacent to HLA class II, was analyzed for a possible causality. To start screening for the molecular variants of RXR beta in OPLL subjects, we first obtained P1 phage genomic clones containing the entire human RXR beta and elucidated the genomic organization of the gene. The human RXR beta is composed of 10 exons spanning over 6.2 kb of genomic DNA. Sequence analysis of the promoter region revealed a GC-rich sequence without TATA motif. We have identified three distinct molecular variants, one was in exon 10 and two were in the intergenic region between RXR beta and collagen 11A2 (COL11A2). Two variants in the intergenic region, 3' end + 140 and 3' end + 561, exhibit statistically significant associations with OPLL in case-control study (p = 0.0028 for 3' end + 140 and p = 0.034 for 3' end + 561). These results indicate that the genetic causality of OPLL lies within or close to the RXR beta/COL11A2 locus.

Adult↗
PubMed1999

A parasympathetic ganglion innervating the harderian gland and lacrimal gland of the musk shrew (Suncus murinus): fluorescent tracing and immunohistochemical studies.

A small ganglion, named the peri-trigeminal ganglion (PTG), was found in the ventromedial border of the rostral half of the trigeminal ganglion (TG) in the musk shrew (Suncus murinus). In frontal sections, the PTG was semicircular or elliptical in shape. Most of the neurons constituting this ganglion were round in shape and much smaller than those of the TG. The retrograde fluorescent tracer fluoro-gold was injected into various regions of the face in order to investigate innervation by the PTG neurons. When the tracer was injected subcutaneously around the external acoustic meatus and around the circumference of the orbit, a number of labeled neurons were seen not only in the TG but also in the PTG. After applying the tracer to the lacrimal gland (LG) and the harderian gland (HG), numerous labeled neurons were detected only in the PTG. A few labeled neurons were found in the PTG after injection into the palatoglossal arch. Immunohistochemically, most of the neurons constituting the PTG were positive for vasoactive intestinal polypeptide (VIP) antiserum. And a moderate number of somatostatin (SOM)-immunoreactive neurons and a small number of leucine-enkephalin (L-ENK)-immunoreactive neurons were detected. Numerous substance P-immunoreactive nerve fibers and varicosities were found in the PTG, and fewer L-ENK-, SOM- and VIP-immunoreactive fibers were observed. The present results suggest that the PTG is an autonomic ganglion that resembles in part the pterygopalatine ganglion in other species, and mainly innervates the HG and LG.

Animals↗
PubMed1999

Stretch-induced overproduction of fibronectin in mesangial cells is mediated by the activation of mitogen-activated protein kinase.

An excessive production of extracellular matrix (ECM) proteins in glomerular mesangial cells is considered to be responsible for the development of mesangial expansion seen in diabetic nephropathy. Mechanical stretch due to glomerular hypertension has been proposed as one of the factors leading to an increase in the production of ECM proteins in mesangial cells, but the precise mechanism of stretch-induced overproduction of ECM proteins has not been elucidated. Herein, we provide the evidence that mitogen-activated protein kinase (MAPK) may play a key role in the overproduction of fibronectin (FN) in mesangial cells exposed to mechanical stretch. MAPK, also termed extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK), was activated by mechanical stretch in time- and intensity-dependent manners. Stretch-induced activation of ERK was inhibited by herbimycin A, a tyrosine kinase inhibitor, but not by GF109203X or calphostin C, the inhibitors of protein kinase C. Mechanical stretch also enhanced DNA-binding activity of AP-1, and this enhancement was inhibited by PD98059, an inhibitor of MAPK or ERK kinase (MEK). Furthermore, mechanical stretch stimulated the expression of FN mRNA followed by a significant increase in its protein accumulation. PD98059 could prevent stretch-induced increase in the expression of FN mRNA and protein. These results indicate that the activation of ERK may mediate the overproduction of ECM proteins in mesangial cells exposed to mechanical stretch, an in vitro model for glomerular hypertension seen in diabetes.

Animals↗
PubMed1999

A pilot study on the human body vibration induced by low frequency noise.

To understand the basic characteristics of the human body vibration induced by low frequency noise and to use it to evaluate the effects on health, we designed a measuring method with a miniature accelerometer and carried out preliminary measurements. Vibration was measured on the chest and abdomen of 6 male subjects who were exposed to pure tones in the frequency range of 20 to 50 Hz, where the method we designed was proved to be sensitive enough to detect vibration on the body surface. The level and rate of increase with frequency of the vibration turned out to be higher on the chest than on the abdomen. This difference was considered to be due to the mechanical structure of the human body. It also turned out that the measured noise-induced vibration negatively correlated with the subject's BMI (Body Mass Index), which suggested that the health effects of low frequency noise depended not only on the mechanical structure but also on the physical constitution of the human body.

Abdomen↗
PubMed1999

Whole-body vibration perception thresholds of recumbent subjects--Part 1: Supine posture.

The objective of the present study was to determine perception thresholds for whole-body vibration in the recumbent supine posture in vertical and horizontal directions and to compare the present results with ones obtained at the same laboratory in 1984 and also with ISO frequency weighting curves both in ISO 2631-1 and in ISO 2631-2. The frequency characteristic and thresholds values of the present results are similar to previous results. Weighting curves of ISO, however, show quite different characteristic in both vertical and horizontal directions compared to the present characteristics. It is not suitable to apply weighting curves Wk for the vertical direction, Wd for the horizontal direction and combined curves in ISO to recumbent posture from the results of this present study.

Adult↗
PubMed1999

Whole-body vibration perception thresholds of recumbent subjects--Part 2: Effect of vibration direction.

This paper presents the results of laboratory experiment concerned with perception thresholds for whole-body vibration on recumbent subjects. Thresholds of subjects exposed to x-, y- and z-axis sinusoidal vibration were determined for supine, prone, lying on the left side and lying on the right side subjects (from 1 to 80 Hz). It was clear that the threshold curves, as a function of frequency, had different characteristics for vertical vibrations than for horizontal vibrations in the recumbent postures. Significant differences were found between perception thresholds for vertical vibrations and horizontal vibrations on recumbent subjects.

Adult↗
PubMed1999

[High prevalence of VacA, CagA protein expression and presence of cag pathogenicity island in Japanese Helicobacter pylori isolates].

VacA, CagA proteins and cag pathogenicity island (PAI) were reported to be major virulence factors of Helicobacter pylori. By using specific antibodies, the expression of VacA and CagA was evaluated in Japanese isolates, together with vacuolating assay. To characterize the status of not only cagA, but entire cag PAI, H. pylori isolates were evaluated for cagA and 13 other cagPAI genes by Southern blot. VacA and CagA proteins were expressed in 87% and in 90%, respectively. Vacuolating assay was positive in 84% isolates. Most strains had all cag PAI genes and the only 6% were cag PAI deleted despite of retaining cagA gene. The majority of Japanese isolates were positive for VacA, CagA proteins and cag PAI, and the high prevalence of infection with virulence strains may contribute to the characteristics of H. pylori infection in Japan.

Antigens, Bacterial↗
PubMed1999

[Detection of Helicobacter pylori 23S rRNA gene mutation associated with clarithromycin resistance and its clinical applicability].

Clarithromycin is one of the most important antibiotics for H. pylori eradication. However, 5-10% was reported to be resistant. It has been shown that one point mutation in the 23S rRNA gene is associated with resistance to clarithromycin. We confirmed that this finding applied to the isolates in Japan. To detect H. pylori infection and the mutation simultaneously, we have designed PCR primers specific for H. pylori, and established assays of PCR-RFLP and PCR-preferential homo-duplex formation (PHFA). Compared with other conventional methods, these assays achieved above 95% sensitivity. It is also demonstrated that the eradication rates achieved by clarithromycin-based regimens significantly differed between mutant and wild type infections. By detecting of 23S rRNA gene mutations associated with clarithromycin resistance, patients can be treated with adequate antibiotics with information about resistance.

Anti-Bacterial Agents↗
PubMed1999

[PCR-monitoring of gastric juice obtained with the capsuled string for the evaluation of H. pylori eradication].

We have developed a highly sensitive semi-nested PCR assay, URA-PCR, for the detection of H. pylori ureA gene in gastric juice. The primers were designed according to nucleotide sequence analyses of clinical isolates. The PCR assay has higher sensitivity than conventional methods such as culture. Characteristics of culture-negative but PCR-positive patients were similar to those of culture-positive ones. The PCR assay, using gastric juice samples obtained with capsuled strings, detected 97% cases of relapsed infection within eight weeks after antimicrobial therapy.

Breath Tests↗
PubMed1999

[Usefulness and safety of intravenous thrombolytic therapy for elderly patients with acute myocardial infarction: relationship with cardiac rupture].

The usefulness and safety of intravenous thrombolytic therapy were investigated in 298 patients older than 65 years (145 males, 153 females, mean age 78 years) with acute myocardial infarction from 1984 to 1993. These patients were divided into 2 groups of 88 patients younger than 74 years (Group A) and 210 patients older than 75 years (Group B). Seventy patients received thrombolytic therapy with urokinase (UK) or tissue-plasminogen activator [t-PA (UK96 X 10(4)U: 57 patients, t-PA 30-40 X 10(4)U/kg: 12, UK + t-PA: 1)] within 6 hours after the onset of acute myocardial infarction (Group TL). Two hundred twenty-eight patients received conventional therapy (Group C). There were no differences in the frequencies of the site of myocardial infarction, Killip class, admission within 6 hours after the onset of acute myocardial infarction or thrombolytic therapy between the 2 age groups. In-hospital mortality was significantly higher in Group B than in Group A (43% vs 24%, p < 0.01). In Groups A and B, in-hospital mortality was 20% lower in Group TL compared with Group C (20% vs 25% in Group A, 36% vs 45% in Group B). In Group B, the mortality from pump failure including shock and congestive heart failure was half in Group TL compared with Group C (13% vs 30%). Cardiac rupture was found in 11 patients of Group TL and 7 patients of Group C. Therefore, the mortality from cardiac rupture was fivefold higher in Group TL compared with Group C (8% vs. 1.6% in Group A, 20% vs 3.6% in Group B). Of 11 patients with cardiac rupture in Group TL, 8 patients suffered rupture in the early phase within 12 hours after the onset of acute myocardial infarction and the tear was present near the center of infarcted area in all 7 autopsy cases. The case of recanalization of the infarct-related coronary artery in Group TL revealed moderate to massive hemorrhagic infarction at autopsy. This indicates that the mechanisms involved in cardiac rupture are different in thrombolytic therapy and conventional therapy. Intravenous thrombolytic therapy is effective for the reduction of mortality from pump failure in elderly patients with acute myocardial infarction older than 75 years. However, it must be evaluated as one of the risk factors of cardiac rupture in elderly patients.

Age Factors↗
PubMed1999

An experimental study of surgical treatment for lymphedema in rats: A modified Kinmonth procedure and autologous lymph node capsule-venous anastomosis with lymph node transfer.

This study was carried out in order to determine the effect of various surgical procedures on lymphedema in a rat model. In 26 adult male Sprague-Dawley rats, randomly divided into four groups, surgical lymphedema was created in the left hind limbs.: The control group had no drainage, Group 1 had a conventional Kinmonth operation, Group 2 had a modified Kinmonth operation using the greater omentum and Group 3 had autologous lymph node capsule-venous anastomosis with lymph node transfer. Circumference measurement was performed to calculate percent difference and circumferential reduction rate. In Groups 2 and 3, patent blue violet was injected to identify lymphatics. In all groups, hematoxylin-eosin (H-E) and 5'-nucleotidase stainning were done to evaluate lymphatics histopathologically. The percent difference and the circumferential reduction rate respectively showed the smallest and largest values in Group 2. A significant difference was found between the control group and Group 2 (p < 0.05). Lymphatic vessels were shown by patent blue violet injection in Groups 2 and 3. H-E and 5'-nucleotidase staining revealed patency of lymphatics. A modified Kinmonth procedure using the greater omentum was the most effective procedure for early lymphedema in a rat model and autologous lymph node capsule-venous anastomosis with lymph node transfer was effective for lymph draining in certain conditions, so it may assist in elucidating surgical treatment of lymphedema.

Anastomosis, Surgical↗
PubMed1999

[Syphilitic orchitis: a case report].

Syphilitic orchitis is recently a rare disease in Japan. A 75-year-old man was referred to our hospital with the complaint of persistent swelling of the left scrotal contents in spite of prior antibiotic therapy. We suspected a testicular tumor because of lack of pain, and performed high orchiectomy. The specimen showed wide-ranged necrosis with a non-specific inflammatory change of the testis on hematoxylin-eosin stain. After performing analysis using a polymerase chain reaction method, we reached the final diagnosis of syphilitic orchitis.

Aged↗
PubMed1999

[Statistics on the operations at the Department of Urology, Toyota Memorial Hospital during an 11-year period (1987-1997)].

A clinical statistic survey was carried out on the operations performed at our Hospital from 1987 through 1997. The total number of operations was 3,383 and the number of operations excluding extracorporeal shock wave lithotripsy (ESWL) was 1,672, consisting of 227 (13.6%) operations of the kidney and ureter, 194 (11.6%) operations of the bladder, 481 (28.8%) operations of the prostate and urethra, and 705 (42.2%) operations of the penis and scrotal contents. Since new endourological technology and ESWL were developed for clinical application, the mode of operation has dramatically changed during the last 11 years, trending toward minimally invasive surgery.

Humans↗
PubMed1999

Experimental studies on application of small-caliber vascular prosthesis produced by polyurethane.

It has been suggested that a microporous structure enhances fast and complete endothelialization. For long-term patency, antithrombogenicity and microporous structure are very important factors. In this paper, we have developed a new technique to give a micro-porous structure to small-caliber vascular prosthesis produced by polyurethane which has favorable antithrombogenecity. A mixed solution (tetrahydrofuran: dimethylformamide = 1:1) containing 13 wt% of segmented polyurethane and a variable amount of calcium carbonate (mean particle size of 8 mm in diameter) was dip-coated on a glass mandril of 3 mm and 6 mm in diameter and placed into distilled water for 24 hours. After the glass mandrill was removed, this polyurethane tube was placed into 1 mmol hydrochloric acid for 1 hour, and a microporous polyurethane vascular prosthesis of 20 mm in length was completed. These prostheses of 3 mm and 6 mm in diameter were implanted into the femoral and the carotid arteries, and the abdominal aorta of the dogs, respectively. Patency was recognized by arteriography and Duplex scanning and the removed grafts were inspected macro- and microscopically. Greater hydraulic permeability of this graft was obtained with an increase in the quantity of calcium carbonate mixed with polyurethane. In elasticity, this graft was more similar to the canine jugular vein than the polytetrafluoroethylene graft. Patency was observed 8 weeks after implantation on the arteriogram, and neointima was observed microscopically on the smooth and lustrous lumen. The new polyurethane vascular prosthesis we developed might provide a potential prosthesis for small-caliber vascular reconstruction.

Animals↗
PubMed1999

[Bacillus Calmette-Guerin intravesical instillation treatment for carcinoma in situ of the bladder. Gifu BCG Instillation Therapy Research Group].

We performed a retrospective long-term study to evaluate the efficacy of intravesical instillation of Tokyo 172 strain Bacillus Calmette-Guerin (BCG) on carcinoma in situ (CIS) of the bladder. Between 1989 and 1998, 42 patients with CIS of bladder underwent intravesical instillation of BCG. In the follow-up period from 6 to 116 months (mean: 37.3 months), the efficacy rate of intravesical BCG instillation for CIS of the bladder was 81.0%. Two patients died from the bladder cancer. The non-recurrence rate in patients with grade 2 carcinoma (19 cases) was not significantly different from that in those with grade 3 carcinoma (23 cases). However, the recurrence rate in patients with secondary CIS (15 cases) was significantly higher than in those with primary CIS (27 cases). The recurrence of CIS was observed in 7 of 42 cases. In 6 of 7 patients, CIS recurred within one year after treatment. Total cystectomy was performed in 10 of 42 patients, and pathological findings of muscle layer invasion were detected in 8 patients. Although side effects occurred in 33 patients (77.5%), no clinically significant side effects were observed. Our results suggest that intravesical BCG therapy may be useful for the treatment of CIS of the bladder.

Adjuvants, Immunologic↗