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Biomedical subjects

H Ishida

Publications and source records attributed to H Ishida.

At least 721 records · Page 40Linked to original sources
PubMed1990

[Clinical evaluation of renoscintigraphy using 123I-orthoiodohippurate--comparison with 131I-OIH and measurement of the effective renal blood flow].

Renoscintigraphy using 123I-orthoiodohipprate (123I-OIH) was conducted, and the dynamic imaging study results and the renograms were analyzed. The results using 123I-OIH were compared with those using 131I-OIH in 22 of 33 patients. Measurement of the effective renal blood flow (ERBF) was also performed using 123I-OIH by the single blood-sample method. 123I is a more suitable nuclide for gamma-camera scintigraphy than 131I in terms of physical characteristics, and a larger dose of 123I-OIH is possible than 131I-OIH because of its lesser radiation. These are the reasons why clearer dynamic images of the blood flow phase, functional phase and excretion phase can be obtained. These make possible diagnoses associated with the organic changes and functions. No essential differences could be found in the functional study results of renogram between the two drugs because on the nuclide of 131I is replaced by 123I, but a renogram with less statistical noise could be obtained using 123I-OIH than 131I-OIH. The radiation dose of 123I-OIH is less than that of 131I-OHI, and clearer dynamic images and functional indexes can be easily obtained in scintigraphy using 123I-OIH. It is concluded that 123I-OIH is a useful radiopharmaceutical for renal examination, and it should replace 131I-OIH.

Adolescent↗
PubMed1990

N-2 acetylation of 2'-deoxyguanosine by coffee mutagens, methylglyoxal and hydrogen peroxide.

Coffee shows direct-acting mutagenicity in Salmonella typhimurium TA100 and most of this mutagenicity is due to the synergistic effects of methylglyoxal and hydrogen peroxide. The modifications of deoxyribonucleosides by methylglyoxal plus hydrogen peroxide were studied in vitro. When 2'-deoxyguanosine (6.25 mumole) was treated with methylglyoxal (125 mumole) and hydrogen peroxide (125 mumole) in 5 ml of 0.1 M phosphate buffer (pH 7.4) at 37 degrees C for 3 h, N2-acetyl-2'-deoxyguanosine was formed with a yield of 1.1%. Its formation increased time-dependently. By contrast, no appreciable modification of other deoxynucleosides was detected after their incubation with methylglyoxal and hydrogen peroxide under similar conditions. N2-Acetyl-2'-deoxyguanosine was also formed during incubation of 2'-deoxyguanosine with instant coffee.

Acetylation↗
PubMed1990

Transmission electron microscopic characterization of hypersensitive human radicular dentin.

Transmission electron microscopy (TEM) and x-ray microanalysis (XMA) were used for the study of the ultrastructure of the lumens of dentinal tubules in superficial layers of dentin specimens obtained by use of a new biopsy technique from both hypersensitive and naturally desensitized areas of exposed root surfaces, in vivo. The TEM images showed clearly that the lumens of most of the tubules were occluded with mineral crystals in naturally desensitized areas, but such lumens were empty and surrounded with peritubular and intertubular dentin in hypersensitive areas. Moreover, electron-dense structures that lined peritubular dentin were observed in the empty lumens of dentinal tubules.

Adult↗
PubMed1990

Parathyroid hormone reversibly suppresses the differentiation of osteoprogenitor cells into functional osteoblasts.

The effects of PTH on osteoprogenitor cell differentiation have been analyzed by quantifying its effects on bone nodule formation in an in vitro assay. Fetal rat calvaria cells were plated at 3 x 10(4) cells/35-mm dish, and cultures were maintained for 17-23 days in alpha-Minimal Essential Medium containing ascorbic acid, Na beta-glycerophosphate, and 10% fetal bovine serum. Continuous exposure to PTH at concentrations from 1 pM to 1 nM (2 x 10(-5) to 2 x 10(-2) IU/ml) caused a dose-dependent inhibition of bone nodule formation. Half-maximal inhibition occurred at 0.05 nM, and total inhibition at 1 nM, concentrations much lower than those required to elicit a significant cAMP response in rat calvaria cells. PTH at the concentrations used did not affect cell growth or saturation density. While continuous exposure to 1 nM PTH eliminated bone nodule formation, a single 48-h pulse administered at any time during the 17-day culture period had no effect. When 1 nM PTH was added on day 1 and removed at different times during the culture period, a time-related release from inhibition was observed. Cultures exposed to 1 nM PTH until nodules had developed in the corresponding control cultures and then switched to medium without added PTH rapidly formed clusters of differentiated osteoblasts and nodules within 3 days. PTH added at different times during the culture period and present continuously there-after suppressed formation of new nodules, the magnitude of the effect being a function of the duration of exposure. The results show that PTH at physiological concentrations is a potent suppressor of osteoblast differentiation and that its effect occurs at a late stage in the differentiation of osteoprogenitor cells, probably preventing differentiation of preosteoblasts into osteoblasts.

Animals↗
PubMed1990

Measurement of inhibin concentrations in men: study of changes after castration and comparison with androgen levels in testicular tissue, spermatic venous blood, and peripheral venous blood.

We measured serum inhibin levels in eight untreated patients with prostatic cancer undergoing castration by RIA using an antiserum against 31-kDa bovine follicular fluid inhibin. The inhibin concentrations in testicular tissue and spermatic venous blood were also measured in six of these patients. Serum inhibin levels (mean +/- SD, 377.8 +/- 212.1 U/L), declined rapidly after castration (15 min after, 233 +/- 171.4; 30 min, 224.6 +/- 156.6; 1 h, 181.5 +/- 95.9; 2 h, 174.3 +/- 69.4; 4 h, 122 +/- 6.4; 6 h, less than 120). High concentrations of inhibin were detected in testicular tissue (31,360 +/- 15,180 U/kg), and the levels in spermatic venous blood (3,178.3 +/- 1,386.8 U/L) were approximately 10 times greater than those in peripheral blood (385.5 +/- 233.1 U/L). Testosterone levels were 1,968.2 +/- 992.3 nmol/kg in testicular tissue and approximately 100 times greater in spermatic venous blood (1,631.6 +/- 389.7 nmol/L) than in peripheral blood (18.0 +/- 4.4 nmol/L). These results suggest that circulating inhibin in men mainly originates from testis and that one of the routes of secretion is via the bloodstream.

Aged↗
PubMed1990

Possible involvement of lymphocyte activating factor (LAF) as an endogenous pyrogen in fever induced by the cell wall skeleton of Nocardia rubra (N-CWS).

We investigated whether interleukin-1 (IL-1) acts as an endogenous pyrogen (EP) on the fever caused by the cell wall skeleton of Nocardia rubra (N-CWS) in guinea pigs. IL-1 activity was expressed as potency of lymphocyte activating factor (LAF). When guinea pig peritoneal macrophages were pulse-stimulated with N-CWS (1-100 micrograms/ml), dose-dependent LAF activity was detected in the supernatants after culture for 4 h. Gel filtration of the culture supernatants on Sephadex G-200 showed that the fractions with LAF activity were not the same as those with cytotoxic activity for L-929 cells, which was measured as an index of tumor necrosis factor (TNF) in parallel with LAF activity. Pyretic activity was detected both in the fractions with LAF activity and in those with cytotoxic activity for L-929 cells. Furthermore, when these macrophages were pulse-stimulated again, this time with the supernatant obtained from macrophages previously pulse-stimulated with N-CWS, LAF and cytotoxic activity for L-929 cells continued to be released from the macrophages. We suggest that IL-1 might be a possible EP in the process of fever elicited by N-CWS, and that such an EP stimulates the macrophages to release further IL-1 or TNF. The resultant long-lasting fever would thus be caused by the continuous release of an EP.

Animals↗
PubMed1990

[Study on ear burn model in mice and its significant application].

The experimental ear burn model in mice was developed in order to research the wound surface on a burn injury biochemically, and the following results were obtained: 1) The ear weight tended to increase up to 3 hr after preparation of the burn and then decreased subsequently. 2) Significant increase in leakage of Evans blue (EB) dye into the ear was observed in the burn group as compared to the non-burnt group. The amount of EB dye leaked per ear became the maximum in 3 hr which was similar to the increase in ear weight. 3) Correlation between the ear weight after burn and the amount of EB dye leaked into the ear on the burned site was observed up to 6 hr after preparation of the burn. 4) Vasopermeability of the ear was depressed with antihistamine treatment, but non-steroidal anti-inflammatory drugs had no effect. The ear weight of glucocorticoid-treated mice tended to be decreased as compared with the weight of the burned ear. 5) The histamine contents in the burned ear did not change, but the bradykinin contents significantly increased after the burn.

Animals↗
PubMed1990

Development of monoclonal antibodies against human gastrointestinal cancer.

We have evaluated approximately 10,000 monoclonal antibodies resulting from 14 hybridization of spleen cells from mice immunized with established cancer cell lines. They were screened by binding assays using cancer cell lines or normal fibroblast cells, followed by immunohistochemical study on tissue sections. Ninety-one monoclonal antibodies were obtained by above binding assays. One of them, named KM10 was further investigated. Isotype of KM10 was IgG1 with kappa-light chain. It was shown that KM10 has strong reactivity with tumors of colon, stomach, papilla Vater, and pancreas, while the limited reactivity displayed with normal tissues. The electron microscopic observation revealed that the antigen recognized by KM10 is expressed on the surface of cancer cells. KM10 could mediate ADCC. These results indicate that KM10 is a good candidate for a probe of diagnosis and therapy of cancer.

Antibodies, Monoclonal↗
PubMed1990

Noninvasive ambulatory blood pressure monitoring during clinic visit in elderly hypertensive patients.

The pressor response to blood pressure measurements in a routine outpatient clinic setting has not been adequately characterized. Blood pressure was monitored in 104 hypertensive patients, mean age of 62 years, by noninvasive automatic ambulatory monitoring device at 5 minutes interval throughout the time of their visits to our outpatient clinic. The average rise in systolic and diastolic blood pressures upon patients' visit to doctor's room was 17 and 7 mm Hg respectively. There was concomitant tachycardia (average rise 3 beats/minute). The rise in blood pressure and heart rate was significantly related to the value in the doctor's room, but was not related to either age, the value in the waiting room or treatment. The rise in systolic blood pressure was more prominent in female patients than in males. Blood pressure and heart rate returned to the baseline level by approximately 40 minutes after leaving the doctor's room. These results illustrate a transient rise in blood pressure during measurement by a doctor in an outpatient clinic. Noninvasive ambulatory blood pressure monitoring during clinic visit in hypertensive patients may be a potentially useful and convenient method for the better diagnosis of hypertension by abolishing the alerting reaction.

Adult↗
PubMed1990

[Ultrasonographic study on kidneys in patients with chronic renal failure. Part I. Ultrasonic measurement of renal size and analysis of renal ultrasonotomograms].

Ultrasonograms of 546 kidneys were obtained in 280 patients undergoing chronic dialysis. Dialysed kidneys could be detected in 529 of the 546 kidneys (96.9%) by ultrasonic examination. The ultrasonic diagnoses on dialysed kidneys were contracted kidney in 313 kidneys (59.2%) and acquired cystic disease of the kidney in 107 kidneys (20.2%). Ultrasonic measurement of the size of kidney (length and thickness) revealed that the kidneys in patients with chronic renal failure were much smaller than normal ones. But the kidneys in patients undergoing dialysis for more than 8 years gradually increased in size with incidence of acquired renal cysts. The kidneys in patients with diabetic nephropathy were greater in length and thickness than those with chronic glomerulonephritis. Sonographic features of dialysed kidneys were unclear renal imaging, unidentified central echoes, cortico-medulla + border and increased parenchymal echogenicity. Irregularity of the renal contour had a tendency to increase in number with incidence of cysts in long-term dialysis patients. The ultrasonograms of the kidneys with diabetic nephropathy showed fewer changes than normal ones. No major complication of the kidney was detected in the present study. However, two retroperitoneal hematomas and one renal cell carcinoma developed within two years after this examination. We believe that regular screening of the kidneys by ultrasonic examination is mandatory in patients on chronic dialysis for early diagnosis and treatment of these complications.

Adolescent↗
PubMed1990

[Ultrasonographic study on kidneys in patients with chronic renal failure. Part II. Acquired cystic disease of the kidneys].

Ultrasonic examination of the kidney was performed on 280 patients undergoing chronic dialysis. Acquired cystic disease of the kidney (ACDK) was detected in 107 of 529 kidneys (20.2%). This paper presents an analysis of ultrasonotomograms of ACDK. Ultrasonic measurement of the size of ACDK was 72.5 +/- 15.2 mm in length and 41.7 +/- 9.8 mm in thickness. The size of ACDK was significantly greater than that of contracted kidneys by ultrasonographic diagnosis. With regard to sex distinction the length and thickness of ACDK were significantly greater in males than in females. As for laboratory data, patients with ACDK showed significantly higher values of red blood cell count, hematocrit and serum creatinine concentration compared with contracted kidneys. Prolongation of the dialysis peirod increased the incidence of ACDK. The size of ACDK showed a tendency to increase with duration of dialysis. However, no correlation was noted statistically between the incidence of ACDK and duration of dialysis and between the size of ACDK and duration of dialysis. There was a significantly lower incidence of ACDK in patients with diabetic nephropathy than those with chronic glomerulonephritis. A sonographic feature of ACDK is irregularity of the renal contour because of cystic transformation. Renal imaging, identification of the corticomedullary border, identification of the central echoes and increased parenchymal echogenicity were similar to other dialyzed kidneys. The main complications of ACDK are hemorrhage and tumor formation. We observed two retroperitoneal hematomas and one renal cell carcinoma developed within two years after this examination. The incidence of complications of ACDK was 5.1 per cent. We believe that patients with ACDK should be watched carefully by regular ultrasonic examination for early diagnosis and treatment of these complications.

Adult↗
PubMed1990

Desensitization of mucin secretion from rat submandibular tissues in response to isoproterenol.

Studies on the secretory response of rat submandibular tissues to isoproterenol (IPR) and the neurotransmitter receptors show that beta-adrenoceptors are altered with specific changes in mucin secretion by brief treatment of the tissues with IPR. Mucin secretion is stimulated by IPR in a dose dependent manner. Pretreatment with 10 microM of IPR for 10, 15, or 30 min reduces mucin secretion during further incubation with the same amount of IPR and increases the EC50 values of mucin secretion for IPR. A binding experiment of [3H] dihydroalprenolol (DHA) shows that this pretreatment also reduces the Bmax of beta-adrenoceptors from 162 +/- 2 to 140 +/- 1 fmol/mg protein and increases the IC50 values of IPR from 195 +/- 17 to 685 +/- 73 nM. The alteration in beta-adrenoceptors by brief treatment of IPR is paralleled by a change in the cyclic AMP content in the tissues from 143.2 +/- 3.2 to 102.3 +/- 4.6 pmol/mg protein.

Adenylyl Cyclases↗
PubMed1990

[Kinetics and clinical application of 99mTc-technegas].

Biological characteristics and clinical utilization of 99mTc-technegas were evaluated in three normal volunteers and 10 patients with various pulmonary diseases. 99mTc-pertechnetate (296 MBq (8 mCi] was injected in the crusible of 99mTc-technegas generator, and about 37 MBq (1 mCi) of 99mTc-technegas was inhaled in the lung by three times of deep inspiration. Blood activity was appeared immediately after inhalation of 99mTc-technegas and it was 0.2% of the inhaled dose/liter of blood after 2 hours. Urine activity was also increased after inhalation and cumulative dose was 4.96% of the inhaled dose after 24 hours. The tracer dose to distribution to the lung was about 95% of the total dose in whole body. Biological half time of 99mTc-technegas in the lung was 135 hours and pulmonary image was stable even after 24 hours. Radiation dose to the lung was 0.004 Gy/37 MBq (1 mCi). In patients with pulmonary disease, distribution of 99mTc-technegas was similar to that of 81mKr gas, although defect on 99mTc-technegas image was larger in severe obstructive disease. 99mTc-technegas study was superior over 133Xe gas study to identify the areas of ventilation abnormality more clearly, although quantitative evaluation was difficult in 99mTc-technegas study. On comparative study with 99mTc-aerosol, 99mTc-technegas distributed in more peripheral sites and both methods were cooperative for evaluation of ventilatory disturbance. These results suggest that 99mTc-technegas inhalation study is safe and useful method for ventilation study.

Administration, Inhalation↗
PubMed1990

Trends in dental hygiene applicant pool size and characteristics of students upon entry over three decades.

A survey was conducted to determine trends that have occurred in the dental hygiene applicant pool and characteristics of entering dental hygiene students between 1957 and 1987. A two page, 46-item questionnaire with a cover letter and stamped pre-addressed envelope was mailed to each dental hygiene program director in the United States. A second mailing was sent one month later to directors who had not responded to the first mailing. A total of 106 usable questionnaires were returned, for a 54 percent response rate for 1987 programs. Response rates for programs existing in 1977, 1967, and 1957 were 51 percent, 45 percent, and 45 percent, respectively. For associate degree/certificate and baccalaureate degree programs, results suggest trends toward (1) a dramatic decline in dental hygiene applicants over the past ten years, (2) a decrease in dental hygiene class size, (3) an increase in age of applicants and length of education prior to acceptance into dental hygiene programs, and (4) a slight decrease in applicants' overall grade point average and science grade point average in the past decade. In addition, findings indicate that dental hygiene remains predominantly a Caucasian woman's profession. Implications of these findings for recruitment efforts and the numbers of dental hygienists for the future are discussed.

Adolescent↗