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Biomedical subjects

S Maeda

Publications and source records attributed to S Maeda.

At least 541 records · Page 30Linked to original sources
PubMed1993

Temporary threshold shifts in fingertip vibratory sensation from hand-transmitted vibration and repetitive shock.

Temporary threshold shifts (TTSs) in vibrotactile perception produced by continuous vibration and repetitive shock have been investigated. Subjects were exposed to vertical hand-transmitted 100 Hz continuous vibration and various repetitive shocks of equal energy content formed from one complete cycle of a 100 Hz sine wave. The repetition rate of the cycles was 5, 25, 50, or 100 s-1 while the root-mean-square (rms) acceleration measured over exposures of five minutes was held constant at 2.5, 5, or 10 ms-2 rms (weighted according to British Standard (BS) 6842 and International Standard (ISO) 5349). A control condition with no vibration was also included. Subjects held a handle with 10% of their maximum hand grip force. When exposed to five shocks per second at each of the three frequency-weighted acceleration magnitudes the subjects developed a small TTS. Exposure to 100 shocks per second (continuous vibration) at each of the three frequency-weighted acceleration magnitudes caused a large TTS, although the total frequency-weighted energy was the same as when exposed to five shocks per second. The relation between the TTS, the logarithm of the shock repetition rate, and the logarithm of the frequency-weighted rms acceleration was described by the relation TTS = -16.256 + 11.812 log10 R + 15.179 log10 ahw, where TTS is the temporary threshold shift, R is the shock repetition rate, and ahw is the frequency-weighted rms acceleration according to BS 6842 and ISO 5349. The results suggest that the equal energy hypothesis underlying BS 6842 and ISO 5349 is inappropriate for the prediction of the TTS produced by repetitive shocks.

Acceleration↗
PubMed1993

Intraoperative recordings of evoked extraocular muscle activities to monitor ocular motor nerve function.

During 22 operations in 18 patients, we stimulated the ocular motor nerves electrically, intracranially, and recorded compound muscle action potentials (CMAP) directly from the extraocular muscles with a ring electrode that we developed. Recording electrodes were applied in 52 instances to the superior rectus, medial rectus, superior oblique, or lateral rectus muscle and to the levator palpebrae superioris in 2 instances; CMAP were recorded successfully from 22 muscles. Evoked CMAP were not recorded in 2 instances because of problems with recording equipment; in the remaining 30 instances, no evoked CMAP were recorded because 1) the oculomotor or abducens nerve was not exposed during the operation; or 2) the recording electrode on the superior oblique muscle had not been properly placed to record trochlear nerve CMAP. Placement of this electrode is difficult. Ocular motor nerve function was analyzed preoperatively and postoperatively to evaluate the usefulness of this intraoperative electrophysiological monitoring method in preventing damage to ocular motor nerves. The results of this study showed that monitoring enables surgeons to locate precisely ocular motor nerves that would otherwise have been overlooked and thus possibly injured during surgery. Monitoring results also confirmed the surgeons' visual findings, thus helping the surgeons operate with greater confidence. Further, intraoperative monitoring provided us with some insights into the pathophysiology of ocular motor nerve dysfunction caused by skull base lesions; we documented electrophysiologically the occurrence of the slowing of conduction in the ocular motor nerves. We conclude that monitoring ocular motor nerve CMAP can reduce the incidence of surgical complications such as functional blindness due to inadvertent sectioning of one of these nerves and that it would be worthwhile to conduct studies of this technique in many more cases to validate our findings.

Abducens Nerve↗
PubMed1993

p-Aminohippurate transport in rat renal brush-border membranes: a potential-sensitive transport system and an anion exchanger.

Transport mechanisms of p-aminohippurate (PAH) were investigated in rat renal brush-border membrane vesicles. The uptake of PAH was stimulated by an inside-positive membrane potential created by K+ and valinomycin. This potential-stimulated uptake of PAH was inhibited by various anion transport inhibitors and was saturable. In addition, PAH uptake in the presence of valinomycin was linearly increased in proportion to log[K+]out/[K+]in. On one hand, PAH uptake was stimulated by [14C]PAH/PAH or [14C]PAH/Cl- exchange, and the [14C]PAH/PAH exchange was insensitive to the membrane potential. The uptake by the exchanger was also inhibited by anion transport inhibitors, but the potential-stimulated uptake of PAH was more sensitive to furosemide and 4,4'-diisothiocyano-2,2'-disulfonic stilbene. On the contrary, [14C]PAH/PAH exchange was more sensitive to urate than the potential-stimulated uptake of PAH. These findings indicate that PAH is transported by two distinct transport systems in rat renal brush-border membranes, a potential-sensitive transport system and an anion exchanger.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1993

In situ hybridization using bromodeoxyuridine labelled DNA probe and RNase H.

We developed a modified in situ DNA-RNA hybridization technique and demonstrated c-myc proto-oncogene transcripts in nodular sclerosis type Hodgkin's disease (HD-NS). A hybridization probe was prepared by metabolic labelling of bromodeoxyuridine (BrdU). The hybridized probe was detected with anti-BrdU monoclonal antibody after incubation with ribonuclease H (RNase H), which specifically degrades RNA from DNA-RNA hybrids. In HD-NS, c-myc protooncogene transcripts were demonstrated in the cytoplasm of lacuna cells and a few surrounding lymphoid cells. This modified hybridization method was sensitive and applicable to the study of oncogene expression at a single cell level.

Adult↗
PubMed1993

In situ hybridization at the electron microscopic level using a bromodeoxyuridine labeled DNA probe.

A bromodeoxyuridine (BrdU) labeled DNA probe was used for in situ hybridization at the electron microscopic (EM) level. A BrdU labeled DNA probe was hybridized in situ to cryostat sections of paraformaldehyde fixed OCT compound embedded cultured HL-60 cells. After hybridization, some sections were incubated with FITC-conjugated anti-BrdU monoclonal antibody for fluorescence microscopy (FM), and others were embedded in Quetol for electron microscopy (EM). The ultrathin sections of Quetol-embedded specimens were incubated with the anti-BrdU monoclonal antibody and the immunoglobulin: gold colloid. In both FM and EM studies, the signals were concentrated in the rough endoplasmic reticulum. Moreover, some label was arranged from the nucleus to the cytoplasm at the EM level. Relatively simple methods using the BrdU labeled DNA probe for the detection of the defined nucleic acid sequence with reasonable tissue preservation and high resolution are described here. This method may be useful for developmental and disease related studies of specific mRNA in cells and tissues.

Antibodies, Monoclonal↗
PubMed1993

[Characteristics of bladder tumors showing positive urinary cytology--respective analysis in differentiated and undifferentiated type].

To study the characters of bladder tumors which showed positive urinary cytologies, the results of urinary cytology of untreated bladder tumor patients in our hospital during 10 years between July 1980 and June 1990 were evaluated according to the degree of tumor differentiation, namely differentiated type which did not contain grade 3, and undifferentiated type which contained grade 3. Concerning the differentiated tumors, positive rate of cytology was 37.3% on the whole. Positive rates of multiple tumors or tumors around internal urethral orifice were significantly high, and those of tumors larger than 3 cm, tumors located on posterior wall, left wall or throughout the entire surface, were higher than the overall positive rates. Repeated examinations of yielded increased rates of positive cytology results. Concerning the undifferentiated tumors, the positive rate of cytology was 90.0% on the whole, was not influenced by tumor sizes or locations, and was consistently observed irrespective of the number of times of cytologic examination.

Aged↗
PubMed1993

[Transurethral endoureteropyelotomy].

Transurethral endoureteropyelotomy was performed in a total of 37 patients with primary ureteropelvic junction obstruction or various ureteral strictures. Thirty-one (84%) of the 37 evaluable patients showed a radiographical improvement of hydronephrosis with a mean follow-up period of 15.8 +/- 10.5 months (range: 3-40). The clinical success rates were as follows: primary ureteropelvic junction obstruction, 11/12 92%); upper ureteral stricture, 6/7 (86%); lower ureteral stricture, 14/18 (78%). This endourological procedure required a mean operation time of 38.0 +/- 27.7 minutes and hospital stay of 7.3 +/- 4.9 days. No major complication has been identified. This retrograde procedure has a straight access to the strictured segment of ureteropelvic junction. It is safe and less invasive to the renal parenchym as it does not require percutaneous nephrostomy. Therefore, it might be clinically useful for the treatment of primary ureteropelvic junction obstruction and other ureteral strictures.

Adolescent↗
PubMed1993

In vitro expansion of murine hematopoietic progenitor cells in liquid cultures for bone marrow transplantation: effects of stem cell factor.

In this study, we demonstrated that recombinant stem cell factor (SCF), when used in combination with interleukin-1 (IL-1), IL-3 and IL-1 plus IL-3, promoted the expansion of immature murine hematopoietic progenitor cells in liquid cultures. In cultures with IL-1 plus IL-3 plus SCF, high proliferative potential-colony forming cells (HPP-CFC) increased 7-8-fold compared with the increase in fresh bone marrow cells, while SCF alone had no effect on the expansion of HPP-CFC. SCF also increased the numbers of colony forming unit-spleen (CFU-S) cells in combination with IL-1 plus IL-3. Transplantation of bone marrow cells cultured with IL-1 plus IL-3 plus SCF resulted in reconstitution of hematopoiesis in lethally irradiated mice earlier than transplantation of fresh bone marrow cells. These results raised the possibility that in vitro expansion of hematopoietic progenitor cells, carried out with SCF in combination with IL-1 and IL-3 in liquid cultures, can be utilized in bone marrow transplantation.

Animals↗
PubMed1993

[The significance of c-erbB-2 and int-2 gene alterations and DNA ploidy pattern for aggressiveness of breast cancer].

We have analyzed amplification of the c-erbB-2 and int-2 genes, and restriction fragment length polymorphisms (RFLPs) of the int-2 gene in 105 primary breast carcinomas. In 90 of 105 samples, overexpression of the c-erbB-2 protein and the DNA ploidy pattern were also analyzed. Amplification of the c-erbB-2 and int-2 gene was found in 27% and in 17%, respectively. No statistical correlation between c-erbB-2 and int-2 genes amplification was observed. Overexpression of the c-erbB-2 protein was detected in 28% of samples. A correlation was observed between amplification of the c-erbB-2 gene and positive nodal status. Amplification of the int-2 gene showed no correlation with clinicopathological parameters, except that a significantly higher incidence of amplification was observed in breast carcinoma with more than 4 positive lymph nodes. Genotypes of the int-2 gene identified by RFLPs analysis revealed no correlation with clinicopathological parameters. DNA ploidy pattern, which showed neither correlation with c-erbB-2 nor int-2 genetic alterations, was associated with tumor size and TNM classification. Our result suggests that analysis of genetic alterations of the c-erbB-2 and int-2 genes and the DNA ploidy pattern may be a useful adjunct in the assessment of aggressiveness of breast carcinoma.

Breast Neoplasms↗
PubMed1993

[Studies on background of gamma-GTP abnormality in human multiphasic screening. (Part 1): Effect of obesity and ingestion of alcohol on gamma-GTP level in serum].

The present study deals mainly with the relationship between abnormal gamma-GTP level in serum on the one hand and obesity and ingestion of alcohol on the other hand on the basis of data for 1,493 cases (1,256 male cases, 237 female cases) who visited our clinic for their health check in the short-term human dry dock managed by the Fukuoka University Hospital. Abnormality in gamma-GTP serum level (> 60 mu/ml) was noted in 28.9% of men, which was second highest after 33.5% for the rate of triglyceride abnormality among the laboratory examinations performed in the human dry dock. In women the rate of abnormal LAP level in serum was the highest at 22.0%, while the rate of abnormal level of gamma-GTP was not more than 3%. The rate of abnormal gamma-GTP in serum increased with elevation in the obesity rate. Particularly in men there was a close relationship between the rate of abnormal gamma-GTP in serum and the amount of alcohol ingested, and the rate of abnormal gamma-GTP was 30.8% in men who take between 1 and 2 "gou" of Sake (1 "gou" of Sake contains 30g of alcohol) a day but reached 71.6% in case of the alcohol ingestion exceeding 2 "gou" of Sake. The relative risk ratio for abnormal gamma-GTP in serum was greater for alcohol than for obesity with 6.80 for those who are not obese but drink alcohol and 2.23 for those who are obese but do not drink alcohol. In both men and women, obesity plus ingestion of alcohol brought about a synergistic rather than additional effect. In men the relative risk ratio in the group having both obesity and ingestion of alcohol amounted to 11.5.

Adult↗
PubMed1993

[Studies on background of gamma-GTP abnormality in human multiphasic screening. (Part 2): Principle component analysis by SAS statistic package for computer analysis].

In previous studies we reported that the abnormality of the gamma-GTP level was found not only in hepatobiliary diseases but also in obesity and ingestion of alcohol in healthy individuals. In relation to this results, the present study deals with the relationship between abnormal gamma-GTP level in serum on the one hand and obesity and ingestion of alcohol on the other hand on the basis of test data for 1493 cases (1256 male cases, 237 female cases) who were examined in the short-term human dry dock managed by the Fukuoka University Hospital. To observe how results of various measurements including the degree of obesity and the amount of alcohol ingested exert effects on one another, principle component analysis was done by means of SAS statistic package for computer analysis. In men, as the first principle main components, obesity rate, Hb, Ht, RBC, GPT, gamma-GTP, LAP, GOT, triglyceride and total protein were extracted. As the second main principle components, alcohol, gamma-GTP, MCH, MCV, and HDL were extracted. Theses result demonstrate that the obesity is accompanied by variations in Hb, Ht, RBC and triglyceride and that digestion of alcohol is accompanied by variations in MCH, MCV and HDL in male. In women, components related to erythrocyte and transaminase along with the degree of obesity were extracted as the first main principle components, and principle components related to erythrocyte and alcohol were extracted as the second main components. In either case, alcohol and gamma-GTP were not included.

Adult↗
PubMed1993

[Studies on background of gamma-GTP abnormality in human multiphasic screening. (Part 3): Multiple regression analysis by SAS statistic package for computer analysis].

Multiple regression analysis in 1493 cases (1256 male cases, 237 female cases) who were examined in the short-term human dry dock managed by the Fukuoka University Hospital, was done with gamma-GTP as the dependent variable and other parameters as the independent variables. As the result, 16 variables including LAP, alcohol, GPT, triglyceride, HDL and obesity rate were selected as the variables explaining gamma-GTP by stepwise methods in men. The standard regression coefficient of alcohol is shown to be greater than that of obesity on gamma-GTP. On the contrary, neither alcohol nor the obesity rate was included in this regression formula in women.

Adult↗
PubMed1993

Expression of c-erbB-2 oncoprotein in primary human tumors: an immunohistochemistry study.

An immunohistochemical study was performed with 130 primary malignant human tumors of breast (n = 55)..colon/rectum (n = 16), stomach (n = 19), esophagus (n = 14), lung (n = 15) and liver (n = 11) using the 21N c-erbB-2 specific monoclonal antibody to identify the tumors that over-expressed the c-erbB-2 oncoprotein. Positivity appeared as an intense brown granular staining located predominantly at the cell membrane. This occurred in 41.8% of breast carcinomas, 12.5% of colorectal adenocarcinomas. None of the gastric adenocarcinomas, squamous cell carcinomas of the esophagus, small cell lung carcinomas or hepatocellular carcinomas were positive for the oncoprotein. The result of this study suggests that over-expression of the c-erbB-2 oncoprotein is common in breast cancer and relatively rare in other malignancies examined.

Antibodies, Monoclonal↗
PubMed1993

[Immunohistochemical analysis of overexpression of c-erbB-2 protein in node-positive breast carcinoma].

We studied the overexpression of c-erbB-2 protein in formalin-fixed, paraffin-embedded tissues from matched primary tumors and metastatic lymph nodes derived from each of 95 breast carcinoma patients. Twenty of 95 primary tumors (21%) exhibited positive membrane staining. Positive staining was also detected in the metastatic lymph nodes from 20 patients. In 19 patients overexpression of c-erbB-2 protein was observed in both primary and metastatic lymph nodes, indicating that there is a significant correlation between c-erbB-2 protein overexpression of primary and secondary metastatic lesion. Overexpression of the c-erbB-2 protein was observed at almost the same frequency regardless of clinical stage. The c-erbB-2 protein overexpression was associated with an absence of estrogen and progesterone receptors. Furthermore the overall survival and disease-free survival were reduced, although not significantly, in the patients with c-erbB-2 protein overexpression. Multivariate analysis indicated that overexpression of c-erbB-2 protein was a significant predictor of early relapse for node-positive patients. These results suggest that overexpression of the c-erbB-2 protein plays a role not only in an early stage but also in a metastatic stage in a certain patient subpopulation with breast carcinoma, and that c-erbB-2 protein overexpression analyzed by immunohistochemical techniques is of clinical significance in these patients.

Analysis of Variance↗
PubMed1993

[Pathology and histochemistry of mitral valve prolapse].

UNLABELLED: To analyze the myxomatous changes and the components of acidic glycosaminoglycans (GAG) of the mitral valve in aged patients with the mitral valve prolapse (MVP) syndrome, a pathological and histochemical study was performed on hearts of 18 autopsied cases with MVP. The histochemical study included toluidine blue Ohno's method, and 3 enzymatic digestion tests with streptomyces hyaluronidase, chondroitinase AC-II and chondroitinase ABC. The following results were obtained: 1. The incidence of MVP with mitral regurgitation among 2,060 elderly autopsy patients over 60 years of age was 0.87%. 2. PATHOLOGICAL FINDINGS: marked prolapse was detected in the anterior leaflet of 3 patients, moderate prolapse in the anterior leaflet of 6 and moderate prolapse in the posterior leaflet of 5. Most patients showed greater prolapse in the anterior than in the posterior leaflets. The MVP of 11 patients (61%) was associated with tricuspid valve prolapse. 3. Histological findings: All cases exhibited thickening at the rough zone; 17 patients showed enlargement of the spongiosa layer, and 15 showed a decrease or disappearance of the fibrosa layer. All cases showed various degrees of change in the atrialis layer. The main site of myxomatous change in the mitral valve of MVP was the spongiosa layer of the rough zone. 4. Histochemical findings: Results using 3 methods of enzymatic digestion tests were positive in 13 patients, which suggested that the major component of increased GAG at the myxomatous changes in the mitral valve of MVP was hyaluronic acid, as did the results with Ohno's toluidine blue method.

Aged↗
PubMed1993

[Effective removal of the contaminating host fibroblasts for establishment of human-tumor cultured lines].

We report a useful method for the establishment of cell lines in vitro from human tumors. One of the obstacles to establishing pure human cancer cells in vitro is contaminating fibroblasts in cultures. This obstacle could be overcome by selective-growth control of fibroblasts treated with serum-free GIT medium and their selective elimination with antibiotic Geneticin (G418-sulfate). In this study, the process of establishing cultured cell lines from two oral cavity cancers is demonstrated using GIT medium and Geneticin. The comparative study of the growth of cells of the two oral cavity cancers and of two control normal fibroblast cell lines supported the selective growth inhibition and elimination of normal fibroblasts by the "G-G method".

Aged↗
PubMed1993

[Ureteral obstruction caused by aneurysm of iliac artery].

A 76-year-old man was referred to our hospital because of right hydronephrosis. A retrograde pyelogram showed obstruction of the right ureter at the level where it was crossed by the common iliac artery. A computerized tomography scan demonstrated an encased right ureter and aneurysm of right common iliac artery. Arteriography revealed aneurysm of right common iliac artery. An aorto-iliac graft bypass and ureterolysis were performed with intra-peritoneal displacement of the right ureter. The diagnostic procedures and treatment modalities for ureteral obstruction caused by aneurysm are discussed.

Aged↗