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Biomedical subjects

H Takagi

Publications and source records attributed to H Takagi.

At least 721 records · Page 40Linked to original sources
PubMed1993

Cholecystokinin (CCK)-8-immunoreactivity in the piriform cortex of the rat with special reference to its fine structures.

Characteristic features of cholecystokinin-8 (CCK-8) containing neuronal structures in the rat piriform cortex were examined by the immunocytochemistry at the light and electron microscopic levels. CCK-immunoreactive (CCKI) neurons were divided into at least four distinct morphological classes; bipolar, bitufted, multipolar and semilunar types. Each type of CCKI cells as well as CCKI axon terminals were studied by the electron microscopy in the layer II and III where most of them were located. Bipolar and bitufted types of CCKI cells made synaptic contacts with both non-CCKI and CCKI axon terminals with the former predominance. A total of 200 synaptic contacts formed by CCKI axon terminals were examined by random section analysis. Over 98% of CCKI axon terminals formed symmetrical synapses. In several cases, non-immunoreactive postsynaptic targets were identified; the pyramidal cells and small/medium sized multipolar cells in the layer II and III, and semilunar cells in the layer II. Additionally, the axonal initial segments of non-immunoreactive pyramidal cells were occasionally made symmetrical contacts with CCKI axon terminals. These findings suggest that CCK afferents exert monosynaptic influences on both projecting neurons and interneurons in the piriform cortex, and are thereby involved in the control of cortical neuronal activities.

Animals↗
PubMed1993

Effects of nifedipine, 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate hydrochloride and atrial natriuretic peptide on endothelin-induced antinatriuresis in dogs.

Nifedipine, 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate hydrochloride (TMB-8) or atrial natriuretic peptide (ANP) was infused into the renal artery before and during intrarenal arterial infusion of endothelin-1 (ET) in anesthetized dogs. Before ET infusion, nifedipine (0.1 micrograms kg-1 min-1), TMB-8 (75 micrograms kg-1 min-1) or ANP (10 ng kg-1 min-1) increased the urine flow rate, urinary sodium excretion and fractional sodium excretion with little change in renal blood flow or glomerular filtration rate. ET (2 ng kg-1 min-1) reduced the basal renal blood flow, glomerular filtration rate, urine flow rate, urinary sodium excretion and fractional sodium excretion. Both nifedipine and TMB-8 induced natriuresis during ET infusion; but only TMB-8 completely reversed the ET-induced reduction in fractional sodium excretion and partially antagonized the reductions in urine flow rate and urinary sodium excretion. ANP did not induce substantial urinary responses during ET infusion. Neither nifedipine, TMB-8 nor ANP reversed the ET-induced decreases in renal blood flow and glomerular filtration rate. The present study suggests that in the dog kidney 1) the ET-induced antinatriuresis is caused in part by enhancement of tubular sodium reabsorption, 2) the tubular action of ET depends on TMB-8-sensitive calcium movements but not calcium influx through dihydropyridine-sensitive channels and 3) ANP cannot counteract the ET-induced antinatriuresis.

Animals↗
PubMed1993

Muscle relaxant action of dantrolene sodium in rats.

The relationship between the muscle relaxant action and intramuscular concentration of unchanged dantrolene sodium [1-[5-(p-natrophenyl) furfurylidene amino] hydantoin sodium hemiheptahydrate, dantrolene] by intravenous administration of dantrolene was examined in rats. The mechanism of the muscle relaxant action of dantrolene was also examined. Dantrolene, unlike tolperisone, a centrally acting muscle relaxant, dose-dependently inhibited twitch contraction evoked by electrical stimulation of both the muscle and the phrenic nerve in the rat isolated phrenic nerve-diaphragm preparation to a similar extent (IC50: 9.5 and 6.5 x 10(-6) M, respectively). Inhibition of both twitch contractions by dantrolene (50 microM) was antagonized by 4-aminopyridine (42.5 microM) and caffeine (4 mM). The twitch contraction of the gastrocnemius muscle elicited by sciatic nerve stimulation was inhibited by intravenous administration of dantrolene in a dose-dependent manner. The effective intramuscular concentration of dantrolene producing 50% depression (ID50) was 3.4 micrograms/g tissue, equal to about 1 x 10(-5) M. We thus found a close relationship between IC50 in vitro and ID50 in situ. Furthermore, this study raised the possibility that dantrolene produces its muscle relaxant action by affecting peripheral muscular Ca2+ mobilization.

4-Aminopyridine↗
PubMed1993

Expression of plasminogen activators and their inhibitors in human pancreatic carcinoma: immunohistochemical study.

Expression of plasminogen activators (PA), tissue type (t-PA) and urokinase type (u-PA), as well as PA inhibitors (PAI), type-1 (PAI-1) and type 2 (PAI-2), were investigated immunohistochemically in 97 human pancreatic carcinomas. u-PA expression predominated in pancreatic carcinomas, compared with t-PA [u-PA expression in 76 specimens (78.4%) and t-PA in eight specimens (8.2%)]. PAI-1 expression was detected in 80 carcinoma specimens (82.5%) and PAI-2 in 79 carcinoma specimens (81.4%). PAI-2 expression was significantly lower in carcinomas with peritoneal metastasis (p < 0.02). Strong PAI-2 expression was associated with significantly higher survival than negative or weak PAI-2 expression (p < 0.05). We conclude that immunohistochemical analysis of PAI-2 expression in pancreatic carcinomas may yield important prognostic information.

Adenocarcinoma↗
PubMed1993

Fibronectin expression in salivary gland pleomorphic adenoma.

The distribution of fibronectin in the normal and pleomorphic adenoma of the salivary gland was investigated in forty cases of surgically resected tumor specimens. The immunoreactivity of fibronectin using polyclonal antibody (anti-fibronectin A2 45, Dakopatts, Denmark) was detected in the cytoplasm of intercalated duct cells and certain striated duct cells in normal salivary glands. Pleomorphic adenoma showed few fibronectin positive cells with a scattered or isolated distribution within the epithelial tumor elements of tubulo-ductal or solid foci of tumor cells. Modified myoepithelial cells and luminal cells of tubulo-ductal structures reacted strongly to fibronectin. In hyalinous, myxoid and chondroid areas, fibrillary myoepithelial cells expressed strongly positive reactivity but with diffuse staining in the myxoid and chondroid areas suggesting that fibronectin plays an important role in tumor cell-extracellular matrix interactions to produce the complex histopathological features of pleomorphic adenoma.

Adenoma, Pleomorphic↗
PubMed1993

[A comparative study among ftorafur, ftorafur plus tamoxifen, and tamoxifen in adjuvant therapy for breast cancer. The Chubu Cooperative Study Group of Adjuvant Chemoendocrine Therapy for Breast Cancer, Japan].

A randomized study assessing the efficacy of three treatment of ftorafur (FT), ftorafur plus Tamoxifen (TAM), and Tamoxifen in patients diagnosed as having stage II (N1b) or stage III breast cancer was carried out at 90 institutions in the Chubu district of Japan. After 10 mg of MMC administration on the day of surgery and the next day, patients were allocated to one of three treatments: FT 600 mg/day for 2 years, FT 600 mg/day plus TAM 20 mg/day for 2 years, or TAM 20 mg/day for 2 years. A total of 647 cases were analyzed. No significant differences were observed in the 5-year disease-free survival rates or in the 5-year survival rates. In the stratified analysis, however, a beneficial effect of adding FT to TAM was observed in the patients with ER-positive tumors in the 5-year survival rate, and FT plus TAM treatment was favorable compared with the other two treatments for postmenopausal patients with ER-positive tumors.

Adult↗
PubMed1993

Isolated pancreatectomy for pancreatic head carcinoma using catheter bypass of the portal vein.

We investigated perioperative complications and survival rate in 114 patients with pancreatic cancer who underwent surgical resection between July, 1981 and March, 1992 with an antithrombogenic bypass catheter of the portal vein which we have developed. With this catheter, mesenteric venous blood can be bypassed to the systemic circulation or intrahepatic portal vein to prevent portal congestion or hepatic ischemia during portal obstruction or simultaneous obstruction of the hepatic artery. All the arteries supplying, and veins draining, the pancreas are dissected prior to its manipulation, following which isolated pancreatectomy accompanied by portal vein resection can be performed. Eighty patients (70%) also underwent isolated pancreatectomy. The perioperative death rate was 9.6%, and the main factor contributing to mortality with the bypass method was not portal vein resection, but various postoperative complications, such as insufficiency of the pancreatojejunostomy and thrombosis of the hepatic artery or superior mesenteric artery after resection and reconstruction. We conclude that aggressive surgery with the bypass method increases the operability of pancreatic cancer, although auxiliary therapies combined with radical surgery are necessary to improve the therapeutic outcome for this cancer.

Catheterization↗
PubMed1993

[Severe subcutaneous emphysema and hypercapnia during laparoscopic cholecystectomy].

A 41-year old, 50 kg female was scheduled for laparoscopic cholecystectomy. Anesthesia was induced with thiopental 250 mg IV and endotracheal intubation was performed using succinylcholine 60 mg IV. Anesthesia was maintained with N2O (67%)-oxygen-sevoflurane (1.5-2%) and pancuronium was used for muscle relaxation. The lungs were mechanically ventilated with TV 500 ml and RR 12.min-1. Immediately after the start of incision, PECO2 was 30 mmHg. But about thirty minutes after introducing carbon dioxide pneumoperitoneum, subcutaneous emphysema and high PECO2 (60 mmHg) were noted and arterial blood gas analysis showed PaCO2 63.2 mmHg, PaO2 135.4 mmHg and pH 7.32. Generally in laparoscopic cholecystectomy, subcutaneous emphysema is more common than in gynecologic laparoscopy and especially with severe subcutaneous emphysema, there is a risk of hypercapnia. This is because carbon dioxide in subcutaneous tissue is more absorbable than that in peritoneal cavity. As carbon dioxide in subcutaneous tissue is absorbed continuously after the operation, the patient should be carefully observed postoperatively.

Adult↗
PubMed1993

[Anxiolytic effect of preoperative showing of "anesthesia video" for surgical patients].

Over 60% of preoperative surgical patients are reported to suffer from preoperative anxiety. Since 1986, an anesthesia video, explaining our routine anesthesia procedures has been shown to elective surgical patients preoperatively at our clinic. In 1990, as our anesthesia method was modified, we revised this video and evaluated the effect of this video on their preoperative anxiety. Female patients, in general, have much more anxiety than male patients, and the female patients of 30-59 years of age were the most anxious about their surgical operations not about anesthesia per se. The patients who were to undergo a major surgery, such as gynecological patients also belonged to the most anxious patient group. After demonstrating the video any patient group including gynecological patients of 30-59 years of age was less anxious about the upcoming anesthesia and surgery.

Adolescent↗
PubMed1993

[The quantitative assay of (1-->3)-beta-D-glucan in culture medium of Candida albicans using G-test].

It has been difficult to diagnose the deep-seated fungal infection. Limulus test which originally has been developed to detect endotoxin in blood is also activated by (1-->3)-beta-D-glucan, the cell wall component of the fungi. Factor G in limulus lysate is activated by (1-->3)-beta-D-glucan and not by endotoxin. The quantitative assay of (1-->3)-beta-D-glucan is possible by the G-test using factor G. (1-->3)-beta-D-glucan in RPMI culture medium of Candida albicans was periodically measured using G-test and the effect of antifungal drug or neutrophil to the changes of (1-->3)-beta-D-glucan in the culture medium was studied. Increase in the level of (1-->3)-beta-D-glucan was in parallel with the growth of Candida albicans. G-test may be applied to the clinical diagnosis of fungal infection.

Candida albicans↗
PubMed1993

[Inhaled nonasbestos fibers; pulmonary concentrations and fiber size in autopsied urban residents].

Nonasbestos fiber concentrations and fiber size distribution in autopsied lung tissues of 53 urban residents (34 males and 19 females) were analyzed by low temperature ashing-analytical transmission electron microscopy. The following findings were obtained. 1. Pulmonary nonasbestos fibers were found in all samples. Fiber consisting mainly of aluminum and silicon represented 80.0% of the total nonasbestos fibers observed. 2. The geometric mean concentration of nonasbestos fiber was significantly higher in males (47.6 x 10(6) fibers/g dry lung) than in females (18.2 x 10(6) fibers/g dry lung) (p < 0.05). This may be caused by differences in occupational exposure to nonasbestos fibers between males and females. 3. In females, the geometric mean concentration of nonasbestos fibers of smokers (34.6 x 10(6) fibers/g dry lung) was higher than that of nonsmokers (11.4 x 10(6) fibers/g dry lung), while, in males, the geometric mean concentration of nonasbestos fibers was lower in smokers (53.9 x 10(6) fibers/g dry lung) than in nonsmokers (89.1 x 10(6) fibers/g dry lung). These differences were not statistically significant. 4. The mean value for the ratio of nonasbestos fiber to asbestos concentration which ranged from 2.3 to 268 in males, and from 1.3 to 52.0 in females, was 30.1 and 20.2 respectively. 5. The mean length, diameter and aspect ratio for nonasbestos fibers were 1.01 microns, 0.103 microns and 11.3, respectively. Although nonasbestos fibers were almost equal in length to asbestos, the mean diameter of nonasbestos fibers was almost one-half of that of asbestos. Most of nonasbestos fibers (99.0%) were too small to be visible by light microscopy.

Adult↗
PubMed1993

[Brain metastasis of testicular yolk sac tumor with massive hemorrhage: case report].

A rare case of yolk sac tumor of the testis which metastasized to the brain parenchyma with repeated intra-tumoral hemorrhage is reported. The patient was a 38 year-old-man admitted to the Department of Urology with the chief complaint of painless swelling of the left testis for a period of one year. He underwent orchiectomy with highly suspected malignancy, because chest X-ray examination demonstrated metastatic coin lesions. Pathological examination of the operated specimen showed typical yolk sac tumor of the testis. Postoperative clinical course was uneventful. However, on the 4th postoperative day, the patient suddenly fell into a coma with left hemiplegia and dilated right pupil. CT scan demonstrated an intra-parenchymal hematoma in the right parietal lobe. Emergency craniotomy with evacuation of the hematoma clot was performed. Histological examination of the hematoma clot showed the same histology (yolk sac tumor) as found in the operative specimens of the left testis. After regaining full consciousness, chemotherapy (PEB and PVB) was started. It was effective to reduce the high serum AFP level and the size of the metastatic coin lesions in the lung. However, it was not effective in preventing brain metastasis. He again relapsed into coma due to a newly-developed intra-tumoral hematoma with multiple brain metastasis and died 6 months after the orchiectomy. Yolk sac tumor of the testis is rare in adult Japanese and there is no previous report of its metastasis to the brain parenchyma with intratumoral hemorrhage. We have reviewed the previously reported cases and discussed the brain metastasis of this malignant urogenic tumor.

Adult↗
PubMed1993

[Evaluation on our procedure for autotransplantation of parathyroid glands by the intact-PTH].

In thyroid cancer surgery since 1978 we have made parathyroidal autotransplantation which has been to resect the entire parathyroid, cut fine to mud and autotransplant into greater pectoral muscle. To evaluate our procedure and consider the mechanism of hypocalcemia and tetanus following surgery, we examined the intact-PTH recovered to about 80% of its preoperative value on 14-postoperative-days and thereafter remained almost constant. It remained below the sensitivity of measurement from immediately to 3-postoperative-days, and with our procedure, parathyroid was considered to be totally resected. Comparison between 2 (6 cases) and more autotransplanted glands (11 cases) revealed that the former showed slightly later functional recovery, but recovered to the almost some extent as the other 21-postoperative-days. Comparison between the group requiring calcium supplement therapy (12 cases) and the otherwise (5 cases) revealed almost the same course of recovery. Thus, our procedure seems to enable us to make satisfactory functional preservation and expect functional recovery by 2-gland autotransplantation at least. The supplement therapy was considered not to be detrimental to the take of autotransplanted glands and functional recovery, and no correlation was noted between the onset of tetanus and intact-PTH.

Adult↗
PubMed1993

[Clinical study of total intravenous anesthesia with droperidol, fentanyl and ketamine--effects of nicardipine, diltiazem and nifedipine on intraoperative hypertension].

Effects of Ca ion channel blockers, nicardipine, diltiazem and nifedipine on intraoperative hypertension were evaluated clinically in ninety surgical patients who received various surgical procedures under total intravenous anesthesia with droperidol, fentanyl and ketamine. When the systemic blood pressure exceeded 160 mmHg systolic at least for ten minutes, even though they received a total dose of 10-15 micrograms.kg-1 of fentanyl, one of the following three antihypertension drugs was administered:nicardipine 0.5-1.0 micrograms i.v., diltiazem 5-10 mg i.v. and nifedipine 5-10 mg intranasally. The effects were evaluated by measuring the systemic blood pressure, heart rate and rate pressure product, before the administration as well as 5, 15, 20 and 30 minutes after the administration. Following the injection of the drug a significant 10-20% reduction in the mean systemic blood pressure was observed in the nifedipine group, while less decrease was observed in the diltiazem and nicardipine groups. The mean heart rate in the nifedipine group increased slightly, while a slight decreases was observed in the other two groups. Therefore the rate pressure product was reduced significantly in three groups, but there was no significant difference among them. No adverse episodes such as ischemic changes on E.K.G. and deterioration of the cardiovascular system were encountered in any patients. We conclude that any of these drugs, particularly nifedipine would be appropriate to control hypertension during total intravenous anesthesia with droperidol, fentanyl and ketamine.

Anesthesia, Intravenous↗
PubMed1993

[Plasma levels of isosorbide dinitrate and its metabolites during intravenous infusion in surgical patients--effect of preoperative administration of isosorbide dinitrate].

Nineteen patients with ischemic heart disease were studied to determine plasma levels of isosorbide dinitrate (ISDN) and its metabolites, isosorbide-2-mononitrate (2-ISMN) and isosorbide-5-mononitrate (5-ISMN) for 6 hrs during intravenous administration of ISDN, using gas chromatography. Differences in plasma levels of these substances were also evaluated in patients with or without preanesthetic medication of ISDN. These patients ranging in ages from 42 to 80 years were administered ISDN intravenously at a rate of 1 micrograms.kg-1 x min-1 during anesthesia and surgery. Preanesthetic administration of ISDN consisted of transdermal application of 40 mg dose. Surgery included gastrectomy, pneumonectomy, extended cholecystectomy, radical mastectomy and so on under either enflurane anesthesia or neuroleptanesthesia. Plasma ISDN levels increased and reached a plateau 3 hrs after the start of intravenous infusion of ISDN in patients of both groups. Plasma 2-ISMN levels increased gradually and reached a plateau 5 hrs after the commencement of intravenous administration of ISDN in patients of both groups. Plasma 5-ISMN levels increased gradually reaching the peak 6 hrs after the start of intravenous infusion of ISDN in both groups. Plasma ISDN, 2-ISMN and 5-ISMN levels were slightly higher in patients who received preanesthetic ISDN than in those who did not receive preanesthetic ISDN. However, there were no statistical differences in plasma ISDN or 2-ISMN levels between the groups except prior to the infusion. On the contrary, plasma 5-ISMN levels were significantly higher in patients who received preanesthetic ISDN than in those who did not receive preanesthetic ISDN for 3 hrs after the start of the infusion.

Adult↗