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Biomedical subjects

K Hoshi

Publications and source records attributed to K Hoshi.

At least 19 recordsLinked to original sources
PubMed1995

Intraductal extension of primary invasive breast carcinoma treated by breast-conservative surgery. Computer graphic three-dimensional reconstruction of the mammary duct-lobular systems.

BACKGROUND: Intraductal tumor extension is a characteristic feature of primary breast carcinoma, and is an important consideration in patients undergoing breast conservative surgery. However, there have been no reports of studies of intraductal extension within the mammary ductal tree. METHODS: Quadrantectomy specimens from 20 patients with primary invasive breast carcinoma were examined by subgross and stereomicroscopic technique to visualize intraductal tumor extension. Serial 2 mm-thick sections were subjected to two-dimensional (2-D) tumor mapping, measuring the distances and angles of extension, and to three-dimensional (3-D) reconstruction of the mammary duct-lobular systems by means of computer graphics. RESULTS: Intraductal tumor extension was found in 16 of 20 specimens (80.0%), extending continuously from the primary invasive carcinoma through the mammary ductal tree. The distances and angles of extension were larger in tumors with microcalcifications, papillotubular invasive ductal carcinoma, 30% or more of intraductal component, and comedo-type intraductal tumor extension. The 3-D reconstructions demonstrated three types of extension; central (11 cases), peripheral (3 cases), and mixed (2 cases). Further, there were some ductal branches anastomosing with different mammary duct-lobular systems at various sites. In one specimen, intraductal tumor extended widely from the primary invasive carcinoma through a branch connecting adjacent mammary duct-lobular systems. CONCLUSIONS: Three-dimensional reconstruction images of intraductal extension of invasive breast carcinomas are presented for the first time to the authors' knowledge. Examples of ductal anastomoses were observed, and should be considered as a risk factor for possible widespread intraductal extension through multiple mammary duct-lobular systems.

Adult↗
PubMed1995

Inhibition of cholesterol synthesis ex vivo and in vivo by fluvastatin, a new inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase.

The inhibitory effect of fluvastatin sodium (fluvastatin), a new type of 3-hydroxy-3-methylglutaryl (HMG) coenzyme A inhibitor, on de novo cholesterol synthesis was investigated and compared with that of pravastatin. Fluvastatin at a concentration of 12.5 mg/kg inhibited sterol synthesis ex vivo from [14C]acetate in rat liver and ileum by 97-99% with respect to the control, while the inhibition in kidney was 55%. The inhibition by fluvastatin in the liver and ileum persisted for approximately 9 h after administration. Significant differences between fluvastatin also had an inhibitory effect on cholesterol synthesis in vivo in various tissues of rats given [14C]acetate intraperitoneally. Sterol synthesis in the liver, ileum and kidney was inhibited by over 95% 3 h after administration of 6.25 mg/kg of fluvastatin. Significant differences between fluvastatin and pravastatin were found in the liver and ileum. Fluvastatin was more potent than pravastatin in inhibiting both ex vivo and in vivo sterol synthesis in the ileum (but not in kidney) and liver.

Acetates↗
PubMed1995

A case of uterine cervical adenoid cystic carcinoma: immunohistochemical study for basement membrane material.

BACKGROUND: Adenoid cystic carcinoma is a rare neoplasm of the cervix. Only two reports of immunohistochemical studies for basement membrane material in adenoid cystic carcinoma of the cervix have been reported. CASE: An 80-year-old Japanese woman complained of atypical vaginal bleeding and underwent removal of a cervical polyp; the biopsy specimen revealed a solid variant of adenoid cystic carcinoma. The tumor was composed of nests and nodules of small carcinoma cells, and there were few characteristic cribriform patterns. Immunohistochemical findings for type IV collagen and laminin revealed intercellular cylinders composed of basement membrane material in the solid area without a cribriform pattern. CONCLUSION: The immunohistochemical finding of intercellular cylinders that reacted for type IV collagen was useful for the diagnosis of a solid variant of adenoid cystic carcinoma.

Aged↗
PubMed1995

Intracytoplasmic sperm injection using immobilized or motile human spermatozoon.

OBJECTIVES: To investigate the efficacy of the treatments for oocyte activation on the results of intracytoplasmic sperm injection using immobilized or motile human spermatozoa. DESIGN: The protocol of intracytoplasmic sperm injection was divided into four groups according to the states of sperm used for microinjection and the treatment for oocyte activation. In group A, immobilized sperm is used. The oocyte is activated merely by aspiration of the cytoplasm into the pipette. In group B, immobilized sperm is used. Microinjected oocyte is treated with A23187. In group C, immobilized sperm is used. Electroporation is performed on the microinjected oocyte. In group D, motile sperm is used. The oocyte is activated merely by aspiration of the cytoplasm into the pipette. SETTING: The Obstetrics and Gynecology Hospital, Fukushima Medical College. PATIENTS: The subjects are the cases that had failed fertilization in standard IVF, cases of severe oligozoospermia, and cases of severe asthenozoospermia. RESULTS: No difference was found between the groups as to the survival rate and fertilizing rates of oocytes after intracytoplasmic sperm injection. The cleavage rate of oocytes was high in order of group D, C, B, A. The cleavage rate for groups D, C, and B was significantly higher than group A. Cases of pregnancy were found in groups D and B. CONCLUSION: Using motile sperm rather than immobilized sperm can be expected to produce better results in human ICSI. Activating oocytes positively is needed when immobilized sperm is used.

Cleavage Stage, Ovum↗
PubMed1995

Effects of endothelins on mechanical activity and inositol phosphate production in pregnant rat myometrium.

Endothelins (ETs) caused concentration-dependent contraction in pregnant rat myometrium. ET-2 was as potent as ET-1 in affecting contractile responses, whereas ET-3 was considerably less potent than ET-1 or ET-2. ETs also increased inositol phosphate (IP) production in a dose-dependent manner, with IP production paralleling the contractile response. The rank order of potency for both the contractile responses and IP production was ET-1 = ET-2 > ET-3. When we compared the important oxytocic agent oxytocin, we found that oxytocin (10(-7) M) strongly increased contractility and IP production, and the responses were comparable to those elicited by ET-1 (10(-7) M) and ET-2 (10(-7) M). These results suggest that ET-induced myometrial contraction involves phospholipase C activation, and that a subtype of endothelin receptor existing in pregnant rat myometrium could be classified as ETA.

Animals↗
PubMed1995

Plasma thrombomodulin levels in coronary sinus blood in patients with coronary artery disease.

Plasma thrombomodulin (TM) levels in coronary sinus blood were measured in 15 patients with coronary artery disease who underwent elective PTCA (group A). TM was also measured in eight patients with coronary artery disease (group B) and six patients without coronary artery disease (group C), who only underwent diagnostic coronary angiography. The baseline level was 21.6 +/- 3.4 U/ml in group A, and 21.0 +/- 4.9 in group B, and both levels were slightly higher (P < 0.05) than those in group C (15.1 +/- 3.3). In group A, the level increased to 27.5 +/- 8.3 (P < 0.01) immediately after PTCA and then returned to 22.2 +/- 5.1 by 24 h. In groups B and C, levels showed no change immediately after angiography. In group A, the percentage increase in the TM level immediately after PTCA from that before the procedure correlated with the number of balloon inflations (r = 0.76, P < 0.01). In conclusion, the plasma TM level in coronary sinus blood might indicate endothelial damage due to atherosclerotic coronary artery disease and an increase in the level after PTCA might directly indicate vascular injury by balloon inflation.

Aged↗
PubMed1995

Effects of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors on mitochondrial respiration in ischaemic dog hearts.

1. Effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, pravastatin and simvastatin, on the myocardial level of coenzyme Q10, and on mitochondrial respiration were examined in dogs. 2. Either vehicle (control), pravastatin (4 mg kg-1 day-1), or simvastatin (2 mg kg-1 day-1) was administered orally for 3 weeks. First, the myocardial tissue level of coenzyme Q10 was determined in the 3 groups. Second, ischaemia was induced by ligating the left anterior descending coronary artery (LAD) in anaesthetized open chest dogs, pretreated with the inhibitors. After 30 min of ischaemia, nonischaemic and ischaemic myocardium were removed from the left circumflex and LAD regions, respectively, and immediately used for isolation of mitochondria. The mitochondrial respiration was determined by polarography, with glutamate and succinate used as substrates. 3. Simvastatin significantly decreased the myocardial level of coenzyme Q10, but pravastatin did not. 4. Ischaemia decreased the mitochondrial respiratory control index (RCI) in both groups. Significant differences in RCI between nonischaemic and ischaemic myocardium were observed in the control and simvastatin-treated groups. 5. Only in the simvastatin-treated group did ischaemia significantly decrease the ADP/O ratio, determined with succinate. 6. The present results indicate that simvastatin but not pravastatin may cause worsening of the myocardial mitochondrial respiration during ischaemia, probably because of reduction of the myocardial coenzyme Q10 level.

Animals↗
PubMed1995

Systemic amyloidosis following ankylosing spondylitis associated with congestive heart failure. A case report.

We report the case of a 38-year-old man who developed fatal, systemic amyloidosis following ankylosing spondylitis. He was admitted for symptoms of congestive heart failure. Based on parotid gland biopsy and echocardiography, he was diagnosed as having systemic amyloidosis following active ankylosing spondylitis. However, the clinical course was rapidly progressive and eventually the patient died of acute necrotizing pancreatitis. The association has been reported thus far in a limited number of cases worldwide. The literature has featured localized lesions and a benign clinical course of the amyloidosis. This case, the first report from Japan, indicates that the amyloidosis associated with ankylosing spondylitis might exhibit a rapidly progressive clinical course, thereby suggesting that in such a case, meticulous treatment is required.

Acute Disease↗
PubMed1995

[Influence of endotoxin on sensitivity to oxytocin in pregnant rat myometrium].

In order to clarify the mechanism of preterm labor induced by intrauterine infection, we studied the effect of endotoxin on oxytocin sensitivity of the myometrium in the pregnant rat. We administrated bacterial endotoxin obtained from Escherichia coli to the pregnant rat at preterm. By using a myometrial strip, we determined the effect of oxytocin on contractility, production of prostaglandins (PGs) and phosphoinositide hydrolysis. 1. Endotoxin increased myometrial sensitivity to oxytocin in the pregnant rat at preterm. The pD2 value was equal to that of myometrium taken from term pregnant rat. This hypersensitivity was significantly inhibited by indomethacin. 2. In the myometrial strips from rats to which endotoxin was administered, the concentrations of PGF2 alpha and PGE2 had already developed a tendency to increase during spontaneous contractions, when compared to the controls. There was seen a significant additional increase due to oxytocin. PGF2 alpha production was also significantly inhibited by indomethacin. 3. Oxytocin significantly stimulated total inositol phosphate production in a dose-dependent manner in myometrium taken from preterm pregnant rat. The inositol 1.4.5-trisphosphate production stimulated by oxytocin significantly increased in comparison to the controls. These results suggest that not only the production of PGs but phosphoinositide hydrolysis of transmembrane signaling pathways would play an important role in the mechanism of myometrial contraction at preterm when intrauterine bacterial infection developed.

Animals↗
PubMed1995

[Pathological characterization of atypical ductal hyperplasia of the breast].

To clarify the pathological features of atypical ductal hyperplasia (ADH) defined by Page's criteria, histological patterns and the extent of 17 lesions of ADH including clinging carcinoma were examined. The nuclear measurements (mean nuclear area and irregularity of nuclear shape) and the MIB-1 labeling index of ADH were compared with those of noncomedo DCIS with lower grade nuclei, and usual ductal hyperplasia (DH). All ADH were classified into cribriform or micropapillary/clinging types. The extent of ADH was always less than 2.5 mm in the cribriform type (1.4 mm in average), against 5 mm or greater in 6 of 8 lesions of the micropapillary/clinging type (7.1 mm in average). Nuclei of ADH tended to be smaller (< or = 8 microns) than DH and DCIS (p < 0.05), and less irregular in shape than DH (p < 0.01), although indistinguishable from lower grade nuclei of DCIS using these parameters. The MIB-1 labeling index of ADH was very low (0-2.3%) and was the best parameter to distinguish from DCIS (p < 0.01). It was also suggested that the lower level of proliferative activity is one of the most distinctive features of ADH.

Breast↗
PubMed1995

[Quality of life, subjective health status and health and life satisfaction in rheumatoid arthritis].

A Japanese version of Arthritis Impact Measurement Scales (AIMS) was developed after the original AIMS Version 2 and utilized for Quality of Life (QOL) measurement in 691 patients with Rheumatoid Arthritis (RA). Various medical (physical and laboratory) examinations, which are widely used in the clinical settings for the assessment of RA activity and severity, were also performed by physicians. Interrelationships between QOL, patient subjective health status, and health and life satisfaction were analyzed with the following results: 1: The effect of QOL impairment by RA upon patients' subjective health rating and health satisfaction were not constant over the range of severity of disease status. Pain was found to lower overall subjective health and health satisfaction regardless of RA class. On the other hand, while the deterioration of mobility aspects of QOL had negative effects upon patients' subjective health status and satisfaction among less-disabled RA patients, any of physical aspects of QOL, including the degree of mobility impairment, showed no significant association with patients' subjective health status and satisfaction in the more disabled. 2: Psychological aspects of QOL (mood and tension) had significant associations with patients' subjective health status and satisfaction. In the less severe group, mood impairment had a significant effect on subjective health and satisfaction, while in the more severe group tension showed a significant association. It was indicated that management of psychological aspects of QOL is important in RA patients to improve and advance their subjective health status and satisfaction. 3: Although social aspects of QOL, i.e. social support, social life and job status, showed no significant relationship to subjective health rating and health satisfaction, those with less disease severity who lacked social support and who had a jobless state were likely to have lower disease acceptance and life satisfaction, while those with more severe disease who had less social interaction manifested lower life satisfaction. These results suggested that social aspects of QOL, while not directly associated with subjective health rating, could be important factors affecting disease acceptance and life satisfaction.

Adult↗
PubMed1994

Synthesis of androst-5-en-7-ones and androsta-3,5-dien-7-ones and their related 7-deoxy analogs as conformational and catalytic probes for the active site of aromatase.

A series of androst-5-en-7-ones and androsta-3,5-dien-7-ones and their 7-deoxy derivatives, respectively, were synthesized and tested for their abilities to inhibit aromatase in human placental microsomes. All the steroids inhibited the enzyme in a competitive manner with Ki's ranging from 0.058 to 45 microM. The inhibitory activities of 17-oxo compounds were much more potent than those of the corresponding 17 beta-alcohols in each series. Steroids having an oxygen function (hydroxy or carbonyl) at C-19 were less potent inhibitors than the corresponding parent compounds having a 19-methyl group. 3,5-Dien-7-one 24 and its 19-hydroxy and 19-oxo derivatives (12 and 13) as well as 19-oxo-5-en-7-one 3 caused a time-dependent inactivation of aromatase only in the presence of NADPH in which the kinact values of 19-als 3 and 13 (0.143 and 0.189 min-1, respectively) were larger than those of the corresponding 19-methyl (23 and 24) and 19-hydroxy (1 and 12) steroids, respectively. 19-Nor-5-en-7-one 4 but not its 3,5-diene derivative 14 also inactivated the enzyme in a time-dependent manner. In contrast, 7-deoxy steroids 21 and 27, having a 19-methyl group, did not cause it. The inactivations were prevented by the substrate androstenedione, and no significant effects of L-cysteine on the inactivations were observed in each case. The results suggest that oxygenation at C-19 would be at least in part involved in the inactivations caused by the inhibitors 23 and 24. The conjugated enone structures should play a critical role in the inactivation sequences.

Androstadienes↗
PubMed1994

Coculture of mouse embryos with cryopreserved human oviduct epithelial cells.

PURPOSE: The effect of coculturing mouse embryos with cryopreserved human oviduct epithelial cells was investigated. The cryopreserved cells in Cellbanker were thawed and cultured in Richard D. Goldsby culture medium to establish monolayers. Two-cell-stage mouse embryos were cultured alone (control group) or cocultured with monolayers established from cryopreserved cells (cryopreserved coculture group) or from fresh cells (fresh coculture group). The rates of embryo development and the qualities of the blastocysts in the three groups were compared. RESULTS: The two coculture groups had significantly higher blastocyst development rates (cryopreserved coculture group, 81.6%; fresh coculture group, 82.2%) than the control group (63.1%). The two coculture groups had significantly more blastomeres (cryopreserved coculture group, 108.3 +/- 25.9; fresh coculture group, 108.4 +/- 25.1) than the control group (87.7 +/- 31.9). CONCLUSION: The method of cryopreservation of human oviduct epithelial cells using Cellbanker is simpler than conventional cryopreservation methods. These cryopreserved human oviduct epithelial cells may provide a constant supply of cells for coculture for in vitro fertilization and embryo transfer.

Adult↗
PubMed1994

A case of quadruplet pregnancy containing complete mole and three fetuses.

A case of a quadruplet pregnancy containing a complete mole and three fetuses is reported. A 29-year-old Japanese woman who had received clomiphene therapy was delivered of a complete mole, one dead and two living fetuses, and three placentas. Deoxyribonucleic acid fingerprint analysis proved the androgenesis of molar tissue and the trizygosity of the three fetuses.

Adult↗
PubMed1994

Localization of fibronectin on the surface of human spermatozoa and relation to the sperm-egg interaction.

OBJECTIVES: The mechanism of human sperm-oolemma adhesion and penetration as well as localization of fibronectin on the sperm head and its relation to fertilization were investigated. DESIGN: Sperm-oolemma interaction was examined with an in vitro assay of the human sperm-zona-free hamster egg interaction. Localization of fibronectin on the surface of human spermatozoa was observed by the back scattered electron imaging mode of the scanning electron microscopy (SEM). RESULTS: It was confirmed by observations under SEM that the anterior tip of the sperm head is the first to come into contact with the egg plasma membrane but that the equatorial segment of the sperm head is the first to be trapped by microvilli of the plasma membrane and that the postacrosomal region is first incorporated into ooplasm. Localization of fibronectin on the equatorial segment of the human sperm head was detected by SEM. Antifibronectin antibodies inhibited human sperm-oolemma adhesion significantly. CONCLUSIONS: Important involvement of fibronectin in the gamete interaction was made clear by the fact that fibronectin is localized in the region where a spermatozoon is fused first with the egg plasma membrane during fertilization and that the sperm adhering to the egg is inhibited by antifibronectin antibodies.

Animals↗