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Biomedical subjects

Y Nishimura

Publications and source records attributed to Y Nishimura.

At least 1,351 records · Page 75Linked to original sources
PubMedDate not supplied

Increased heating efficiency of hyperthermia using an ultrasound contrast agent: a phantom study.

It is known that there are large temperature elevations in proximity to air bubbles during US (ultrasound) heating. The existence of tiny air bubbles in the target tissue may enhance the temperature elevation in US hyperthermia. To examine this hypothesis, phantom tissue experiments using an US contrast agent consisting of tiny air bubbles surrounded by a 5% (w/v) human albumin shell (Alb) were performed. As a phantom tissue, a 2 cm cube of beef was used. The phantom tissue was heated with or without the US contrast agent by an US hyperthermia device for 3 min. The heating device was operated at 1.5 MHz with the US intensity of 0.9 W/cm2. Physiological saline solution, iodized oil, and ethanol were used for control experiments. The effect of multiple needle punctures to the beef phantom was also examined. The temperature elevation rate (TER) was defined as the ratio of temperature elevation by heating with Alb or control materials to the temperature elevation by US heating alone. The TER of Alb was 1.7, whereas the TERs of the control materials and of the multiple needle punctures were approximately 1. The administration of Alb significantly increased the temperature in US hyperthermia. In addition, the heating efficiency of Alb was compared to the effect of an increase in the US intensity. Phantom tissue was heated at various US intensities. When the US intensity was increased from 0.9 to 1.8 W/cm2, the temperature elevated by approximately 1.7-fold. Thus, the effect of the administration of Alb was almost equivalent to the effect of increase in US power intensities from 0.9 to 1.8 W/cm2 in the present experimental settings. The results suggest that the US contrast agent can be a potential enhancer in US hyperthermia.

Hyperthermia, Induced↗
PubMedDate not supplied

Scrotal ulcer occurring in patients with acute promyelocytic leukemia during treatment with all-trans retinoic acid.

Although all-trans retinoic acid (ATRA) has been shown to improve the outcome of patients with acute promyelocytic leukemia (APL) compared with chemotherapy alone, various adverse effects have been reported. We report here the development of scrotal ulcer in four patients with APL during ATRA treatment. ATRA 45 mg/m2 was administered orally to four patients with newly diagnosed APL, two of whom also received chemotherapy. Scrotal ulcers appeared in all four patients after a median of 22 days (range: 17-29 days) of ATRA treatment. ATRA was discontinued in only one patient, who was then treated with methylprednisolone pulse therapy. The fever resolved, and scrotal ulcer improved after this treatment. The other three patients were treated with steroid or antibiotic ointment for scrotal ulcers. ATRA was re-administered 2 years later in one patient who had relapse of APL. Ulcers appeared again on the scrotal and lower abdominal skin on day 27 of ATRA treatment. These findings strongly suggest that scrotal ulcer is a potential adverse effect of ATRA.

Abdomen↗
PubMedDate not supplied

Concurrent chemoradiotherapy combined with intraoperative radiotherapy for locally advanced pancreatic cancer: a feasibility study.

Initial clinical results of concurrent chemoradiotherapy combined with high-dose intraoperative radiotherapy (IOR) for locally advanced pancreatic cancer were analyzed. Between June 1996 and May 1999, 6 patients with locally advanced pancreatic cancer without distant metastasis were treated with preoperative concurrent chemoradiotherapy followed by IOR. Preoperative radiation therapy was given by the dynamic arc conformal technique with a daily fraction of 1.8 Gy to a total dose of 45 Gy in 5 weeks. Cisplatin (5 mg/day for 4 weeks) and 5-fluorouracil (250 mg/day for 5 weeks) were administered continuously during preoperative radiation therapy. IOR as a single dose of 28 or 30 Gy was given to the gross tumor volume using electron beams of 15- to 22-MeV. Concurrent chemoradiotherapy was well tolerated, although all of the patients complained of nausea and fatigue. Two patients developed grade III leukopenia. No other serious acute toxicity was noted. The median survival time of the 6 patients was 17.5 months, which was significantly longer than that of our historical control treated with external radiation therapy with IOR (8 months), although the difference in survival was borderline significant (p=0.068). Concurrent chemoradiotherapy followed by high-dose IOR was well tolerated in patients with locally advanced pancreatic cancer, and the initial clinical results appeared promising.

Adult↗
PubMedDate not supplied

Altered expression of retinoic acid (RA) receptor mRNAs in the fetal mouse secondary palate by all-trans and 13-cis RAs: implications for RA-induced teratogenesis.

Retinoic acid (RA) is mandatory for various biological processes and normal embryonic development but is teratogenic at high concentrations. In rodents, one of the major malformations induced by RA is cleft palate (CP). RA mediates its effects by RA receptors (RARs), but the expression patterns of RARs in the developing palate are still unclear. We investigated the normal expression of RAR alpha, beta, and gamma messenger RNAs (mRNAs) in the fetal mouse secondary palate and the effects of all-trans and 13-cis RAs on the expression of RAR mRNAs by Northern blot analysis. RAR alpha (2.8, 3.8 kb), RAR beta (3.3 kb), and RAR gamma (3.7 kb) mRNAs were detected in the fetal palate on gestational days (GD) 12.5-14.5. The expression of RAR alpha and gamma mRNAs did not show apparent sequential changes, but that of RAR beta mRNA increased at GD 13.5. Treatment of pregnant mice with 100 mg/kg all-trans RA induced CP in 94% of the fetuses and elevated the levels of RAR beta and gamma mRNAs in the fetal palate. The up-regulation of RAR beta mRNA by all-trans RA was more marked than that of RAR gamma mRNA. Treatment with 100 mg/kg 13-cis RA induced CP in only 19% of the fetuses. Although 13-cis RA elevated the RAR beta and gamma mRNA levels in fetal palates, its up-regulation was slower and less marked than that induced by all-trans RA. These findings indicate that the induction of RAR beta mRNA in the fetal palate correlates well with the tissue concentration of all-trans RA after RA treatment, and RAR beta may be one of the most influential candidate molecules for RA-induced teratogenesis.

Animals↗
PubMedDate not supplied

[A case of bilateral brachial plexopathy after median sternotomy].

A 53-year-old man with bilateral brachial plexopathy after median sternotomy for cardiac surgery was described. When he was awakened six days after cardiac surgery, he experienced weakness and paresthesia of both upper limbs. Neurological examination revealed moderate to severe atrophy and weakness of right biceps, brachioradialis, left triceps, and distal muscles of both upper limbs, and paresthesia around the right thumb and the left hypothenar. Deep tendon reflex of the right biceps, triceps, brachioradialis and left triceps was absent. In addition, he showed Horner's syndrome at the left side. The results of needle EMG and nerve conduction study indicated the damage of the right upper trunk and left middle and lower trunks of the brachial plexus. Although brachial plexopathy following median sternotomy has previously been reported in Western literatures, there is only a single report of unilateral brachial plexopathy in Japan. This is the first report in Japan of the bilateral brachial plexopathy following median sternotomy, and suggests that brachial plexopathy should be recognized as a complication of median sternotomy.

Brachial Plexus↗
PubMedDate not supplied

Cyclin D1 expression in endometrioid-type endometrial adenocarcinoma is correlated with histological grade and proliferative activity, but not with prognosis.

To elucidate carcinogenesis in the endometrium, we investigated cyclin D1 immunoreactivities in 20 normal endometria, 20 endometrial hyperplasias and 141 endometrioid-type endometrial adenocarcinoma. We also evaluated the correlation of cyclin D1 expression with Ki-67, cyclin E, cyclin A, cdk2, p27 and p53, and clinicopathological parameters and prognosis. Cyclin D1 expression increased significantly with histological grade, and the labeling index (LI) for cyclin D1 was 121 +/- 23.4% in G1, 12.7 +/- 23.7% in G2 and 15.7 +/- 18.5% in G3. The LIs were significantly correlated with those for cyclin E, cyclin A and Ki-67, but not with the LIs of cdk2, p27 or p53. In contrast, high cyclin D1 expression was significantly correlated with low p53 expression. Cyclin D1 expression was not significantly correlated with any of the clinicopathological parameters except histological grade. Cyclin D1 expression was significantly correlated with histological grade and proliferative activity, but not clinicopathological parameters and prognosis in endometrial adenocarcinoma.

Adult↗
PubMedDate not supplied

Clinical usefulness of oral itraconazole, an antimycotic drug, for refractory atopic dermatitis.

We investigated the clinical usefulness of oral itraconazole for refractory atopic dermatitis in a crossover study. Patients with refractory atopic dermatitis were divided into two groups: Group A; a combination of itraconazole plus a conventional lactobacillus preparation was administered for 8 weeks, followed by lactobacillus preparation alone for 8 weeks, Group B; lactobacillus preparation alone was administered for 8 weeks, followed by itraconazole plus lactobacillus for 8 weeks. In both groups, a decrease in dose or strength of concomitant topical steroids was observed at the end of the treatment course of itraconazole, and improvement of parameters such as eosinophil count, serum IgE level and specific IgE antibody titers to fungi was also observed after the administration of itraconazole. These results suggest that oral itraconazole is useful for the treatment of intractable atopic dermatitis patients who do not respond to conventional therapeutic approaches.

Administration, Oral↗
PubMedDate not supplied

Reversal of nonresponders and postexposure prophylaxis by intradermal hepatitis B vaccination in Japanese medical personnel.

Thirty-one Japanese nonresponders to subcutaneous hepatitis B vaccination and 15 medical personnel who were accidentally exposed to specimens positive for hepatitis B e antigen and were given hepatitis B immunoglobulin were intradermally immunized with 5 micrograms of plasma-derived hepatitis B vaccine every 2 weeks until delayed type hypersensitivity skin reaction to hepatitis B surface antigen became positive. Thirty (97%) of the 31 nonresponders developed delayed type hypersensitivity skin reactions to hepatitis B surface antigen after 2.3 +/- 1.2 (mean +/- SD) revaccinations. Twenty-nine (94%) of the 31 nonresponders had anti-hepatitis B surface antigen antibody levels greater than 10 IU/L. The immunoglobulin subclass of the antibody to hepatitis B surface antigen was mainly IgG1. After 1 year, 23 (74%) of the 31 nonresponders continued to have anti-hepatitis B surface antigen antibody levels greater than 10 IU/L. Persons accidentally exposed to specimens positive for hepatitis B e antigen developed delayed type hypersensitivity skin reactions to hepatitis B surface antigen following 3.1 +/- 1.1 revaccinations. None developed clinical hepatitis. There was no production of anti-hepatitis B core antigen antibody 1 year after exposure, indicating that protection was 100%. Intradermal hepatitis B vaccination is useful in reversing nonresponsiveness to hepatitis B surface antigen and for prophylaxis after exposure.

Adult↗
PubMedDate not supplied

Response of mammary tumors of C3H/He mice to hyperthermia and bleomycin in vivo.

The cytotoxicity of bleomycin in vitro has previously been shown to be enhanced by hyperthermia. This study demonstrates in vivo a synergistic interaction between local hyperthermia (43 degrees C, 45 min) and bleomycin (15 mg/kg) against implanted mammary tumors of C3H/He mice. Hyperthermia was given by water bath heating. When combined treatments of heat and bleomycin were administered within 30 min of each other, a synergistic effect was observed. In contrast, when the interval between heat and bleomycin injection was longer than 30 min, only an additive effect was obtained. Timing is therefore considered to be a critical factor for the optimal combination of hyperthermia and bleomycin.

Animals↗
PubMedDate not supplied

Afterloading intracavitary irradiation and expanding stent for malignant biliary obstruction.

A double lumen catheter was developed as an applicator for the remote afterloading (RALS) of 60Co source for the intracavitary irradiation of an obstructed common bile duct caused by carcinoma of the gallbladder. This was followed by the placement of nylon-covered expandable metallic stents to maintain patency. This combination effectively provided palliation.

Brachytherapy↗
PubMedDate not supplied

Postoperative radiation therapy for esophageal cancer.

The value of postoperative radiation therapy (RT) was investigated in 77 patients with esophageal cancer resected between 1977 and 1986. Surgical resection was palliative in 13 of these patients. Although seven of them underwent postoperative irradiation to the residual tumor, all of the patients died within one year. Following potentially curative resection performed in 64 patients, 31 patients received 50 Gy of postoperative RT to the lower neck and the mediastinum (group Ia), seven were unable to receive full-dose postoperative RT (group Ib), and 26 were not treated with postoperative RT (group II). The 5-year survival rate estimated by the Kaplan-Meier method was 54% for group Ia, 29% for group Ib, and 33% for group II, with the difference between groups Ia and II being significant (p less than 0.025). The local recurrence rate in the mediastinum was lower in group Ia than in group II. Prophylactic postoperative RT for esophageal cancer is a safe and effective regimen for patients with resected disease.

Adult↗
PubMedDate not supplied

Probucol therapy in the prevention of restenosis after successful percutaneous transluminal coronary angioplasty.

The effect of probucol, a drug that inhibits the secretion of smooth muscle cell-derived growth factor, was evaluated in the prevention of restenosis after percutaneous transluminal coronary angioplasty (PTCA). In 67 patients who successfully underwent prospective PTCA for the first time, the effects obtained in 31 patients given 750 mg or 1000 mg of probucol daily (group P) were compared with those in 36 patients given 150 mg of dipyridamole daily (group D). Drug treatment was initiated at least 7 days before PTCA and was continued for 3 to 6 months after PTCA, at which time a follow-up angiography was performed. There were no significant differences in patient characteristics (age, sex, pre-PTCA severity of angina pectoris), the number of affected vessels undergoing dilatation, or the residual degree of stenosis. The restenosis rate was significantly lower in group P (6 cases, 19.4%) than in group D (15 cases, 41.7%). In the nonrestenosis subgroup, the degree of stenosis progressed from 28.0 +/- 13.9% just after PTCA to 32.4 +/- 20.5% at follow-up angiography in group P, while it progressed significantly from 28.6 +/- 15.6% to 40.1 +/- 21.2% in group D (P < 0.05). A significant drop in serum cholesterol was observed in group P. The restenosis rate was lower in patients with high cholesterol levels at PTCA. No adverse reactions were noted in any patient. We conclude that probucol is effective in preventing restenosis after PTCA.

Aged↗
PubMedDate not supplied

Intrahepatic cholangiocarcinoma with a long-term survival of 12 years after surgical resection: report of a case and review of the literature.

The prognosis of primary liver cancer, especially cholangiocarcinoma, is extremely poor. A long term, 12 years survivor of intrahepatic cholangiocarcinoma arising in a local dilatation of the intrahepatic bile duct is presented. A 40-year-old male patient was presented with recurrent upper abdominal pain, fever, and jaundice. Computed tomography revealed a localized duct dilatation, and ultrasound clearly demonstrated a tumor mass arising within the bile duct. At surgery in March, 1982, the tumor mass was resected and histologically confirmed as a well differentiated papillary adenocarcinoma arising. In March, 1994, the patient is alive and cancer-free, 12 years after surgical resection. To our knowledge, there has been no report on a patient surviving more than 10 years after initial treatment. This case suggests that a localized cystic dilatation of the intrahepatic-bile duct on imaging modalities may harbor a bile duct carcinoma, and this in turn may contribute to early diagnosis of carcinomas and improved long term survival.

Adult↗
PubMedDate not supplied

Targeted hyperthermia using dextran magnetite complex: a new treatment modality for liver tumors.

BACKGROUND/AIMS: Dextran magnetite complex (DM) is a colloidal suspension of subdomain magnetite particles ('magnetic fluid'). It has been reported that DM generates a great amount of heat in an AC magnetic field. MATERIAL AND METHODS: In this experimental study on Japanese white rabbits, a new treatment modality for liver tumors was examined in which the tumor is selectively heated with an intravascularly administered DM-containing embolic material followed by external application of an AC magnetic field. RESULTS: The heat generation of DM in vitro was found to be more than 3-fold greater than that with magnetite particles of 40-micron diameter. As a DM-containing embolic material, we developed a DM/Lipiodol emulsion. When DM/Lipiodol emulsion was injected into the hepatic arteries of the rabbits following VX2 tumor transplantation into the liver, embolization of the artery and selective heating of the embolized liver were successfully attained following exposure to a 100-kHz AC magnetic field of approximately 15000 A/m. Histological examination of the embolized liver disclosed that DM had accumulated in the hypervascular, viable part of the tumor. CONCLUSION: These results demonstrate the potential feasibility of using a DM-containing embolic material for targeted hyperthermia of liver tumors.

Animals↗