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Biomedical subjects

N Miyazawa

Publications and source records attributed to N Miyazawa.

At least 73 records · Page 4Linked to original sources

1-(Tetrahydro-2-furanyl)-5-fluorouracil (Ftorafur) determined in rat hair as an index of drug exposure.

The fluorescence derivatization of 1-(tetrahydro-2-furanyl)-5-fluorouracil (Ftorafur, FT) with 4-bromomethyl-6,7-dimethoxycoumarin (BrMdmc) with 18-crown-6 as catalyst was utilized for a sensitive and selective liquid chromatographic method to determine the concentration of FT in hair. Hair samples collected from rats, which had received FT intraperitoneally for 1 to 4 weeks, were dissolved in 1 M NaOH by heating at 80 degrees C for 30 min. A three-step extraction procedure for FT in the dissolved hair was used before and after the derivatization of FT with BrMdmc. The detection limit achieved was < 0.16 ng/mg hair. A dose-dependent accumulation of FT was evident in the rat hair (r = 0.914, p < 0.001): 0.24 +/- 0.07, 1.35 +/- 0.39, and 2.85 +/- 0.74 ng/mg hair (mean +/- SD, n = 4-5) at the doses of 5, 15, and 50 mg/kg/day for 4 weeks, respectively. In the rats that had received the highest dose of FT, the accumulation of FT in the hair depended also on the duration of FT administration: 0.82 +/- 0.33 (1 week), 1.52 +/- 0.38 (2 weeks), and 2.85 +/- 0.74 (4 weeks) ng/mg hair (n = 4-5). These findings suggest that the analysis of an oral antineoplasmic FT in the hair may be useful for assessing the degree of exposure to the drug.

Animals↗

High copper and iron levels and expression of Mn-superoxide dismutase in mutant rats displaying hereditary hepatitis and hepatoma (LEC rats).

The LEC rat is a mutant strain displaying hereditary hepatitis and hepatoma. We established enzyme-linked immunosorbent assays of Cu,Zn- and Mn-superoxide dismutase (Cu,Zn- and Mn-SOD) and measured the levels of both SODs in various organs of LEC and Wistar rats. Mn-SOD concentrations were higher in LEC rats than in Wistar rats in most tissues. Cu,Zn-SOD levels of liver, kidney and intestine were lower in LEC rats than in Wistar rats. Atomic absorbtion techniques indicated that in addition to high Cu concentrations as previously reported, LEC rat livers contained high Fe concentrations relative to those in Wistar rat livers. These data suggest that increased concentrations of Fe and Cu and decreased levels of Cu,Zn-SOD may facilitate the Fenton reaction to produce hydroxyl radicals in the tissues of the LEC rat. To compensate for the decreased scavenging effects due to low levels of Cu,Zn-SOD, an adaptive increase of Mn-SOD may occur in the process of hepatitis and hepatocarcinogenesis in LEC rats.

Animals↗

Protection against alpha-naphthylisothiocyanate-induced acute cholestasis in mice by a novel taurine conjugate of ursodeoxycholate (UR-906).

We investigated the effects of tauroursodeoxycholate (UR-906) and ursodeoxycholic acid (UDCA) on alpha-naphthylisothiocyanate (ANIT)-induced cholestasis in mice. UR-906 and UDCA were given intravenously 2 hr prior to and 2 hr after ANIT (80 mg/kg, p.o.) treatment. The animals were sacrificed 48 hr after ANIT administration, and serum markers of liver injury were examined. UR-906 prevented significant elevations in total bilirubin, bile acids and LDH. Furthermore, this drug reduced significant elevations in ALP and LAP. UDCA also prevented significant elevations in total bilirubin and LAP. These results indicate that UR-906 as well as UDCA has a beneficial effect against ANIT-induced cholestasis in mice.

1-Naphthylisothiocyanate↗

[Effects of sevoflurane on hemodynamics during the induction of anesthesia compared with those of isoflurane, enflurane and halothane].

The effects of sevoflurane (S), isoflurane (I), enflurane (E) and halothane (H) on hemodynamics were studied in 50 patients during the inhalation of 1.5 MAC of each anesthetic before the surgery. Mean arterial pressure (MAP), heart rate (HR), cardiac index (CI), systemic vascular resistance index (SVRI) and stroke volume index (SVI) were measured noninvasively using the automatic blood pressure manometer and the ultrasonic Doppler method (Accucom). There were significant differences between E and H in MAP, CI, SVRI and SVI. The values of CI, SVRI, SVI with S, as well as with I, were between those of E and H. These results indicate that sevoflurane causes the depression of blood pressure mostly by decreasing afterload during the induction of anesthesia, although the decrement with sevoflurane, as well as that with isoflurane, is less than that with enflurane.

Adult↗

[A case of squamous cell carcinoma of the trachea in a female cigarette smoker].

A rare case of squamous cell carcinoma of the trachea in a female cigarette smoker is reported. The patient was a 72-year-old female with smoking index of 440 who developed wheezing and dyspnea on December 18, 1991. She was diagnosed as having bronchial asthma and hospitalized, but the symptoms were not improved. Bronchofiberscopic examination was performed and revealed a tracheal tumor on April 24, 1992. She was then referred to this cancer center. CT scan of the neck on admission showed a solid tumor which was 19 x 18 mm in diameter and protruded from the membranous portion and the right side of the tracheal wall into the lumen. Bronchofiberscopic findings revealed a soft polypoid tumor with a whitish coat on the surface and a tendency to bleed, at the second tracheal ring from the vocal cord. Histological findings of the biopsied specimen were compatible with poorly differentiated squamous cell carcinoma. A segmental resection of the trachea with end-to-end anastomosis was performed on May 6th, 1992. Postoperative radiation therapy (50.4 Gy) was added because of the residual microscopic cancer in the distal membranous portion of the tracheal wall. Female cases of squamous cell carcinoma of the trachea have been rarely reported in Japan. The relationship between squamous cell carcinoma of the trachea and smoking is considered.

Aged↗

A study of pharyngeal symptoms caused by bronchofiberscopy.

We investigated the occurrence of pharyngeal symptoms in 100 patients who had undergone bronchofiberscopies by conducting a post-examination survey of the patients. Eighty-four patients complained of having a problem. Seventy-five patients, including 26 with dysphagia, complained of pharyngeal symptoms. The proportion with pharyngeal symptoms whose symptoms appeared on the day of examination was a high 89.4%. In 70.6% of cases, the duration of symptoms was less than four days. The pharyngeal symptoms were particularly common among patients who had undergone a bronchofiberscopy on a previous occasion or whose examination lasted for 15 min or more. A greater dysphagia incidence was noted among patients who had required an endotracheal tube (P = 0.03) and among those whose examination had lasted for 15 min or more (P = 0.01). Based on the results, we are now studying methods of alleviating pharyngeal symptoms, including dysphagia.

Adult↗

[The use of the reverse latissimus dorsi muscle flap in the management of bronchopleural fistula].

The management of a postoperative bronchopleural fistula remains a major challenge for the thoracic surgeon. We present a series of three patients who underwent closure of the fistulas with the distal flap of the divided latissimus dorsi muscle (the reverse latissimus dorsi muscle flap) and a limited thoracoplasty. The primary resections, which were performed through a standard posterolateral thoracotomy, were right lower lobectomy in two patients and right middle and lower bilobectomy in the other. The initial myoplasty produced prompt fistula closure in 2 patients and failed in the other patient because of a large empyema space. The reverse latissimus dorsi muscle flap could be used for the management of bronchopleural fistula in selected patients who underwent lower lobectomy or middle and lower bilobectomy.

Aged↗

Adjuvant chemotherapy for completely resected stage III non-small-cell lung cancer. Results of a randomized prospective study. The Japan Clinical Oncology Group.

Two hundred nine patients with completely resected stage III non-small-cell lung cancer were randomized to receive postoperative cisplatin and vindesine chemotherapy or no further treatment. Before randomization, patients were stratified by the histologic characteristics of their tumors (squamous versus nonsquamous cell carcinoma). Prognostic variables such as histology, performance status, extent of operation, and tumor and nodal status of the eligible patients in chemotherapy (n = 90) and control groups (n = 91) were equally distributed. There was no statistically significant difference in disease-free and overall survival between the two groups. The 3-year disease-free survivals of the chemotherapy and control groups were 37% and 42%, respectively. The median survival times (5-year survival) were 31 months (35%) in the chemotherapy group and 37 months (41%) in the control group. These was no different pattern in the first site of recurrence (local versus systemic) between the two groups. This study failed to demonstrate the therapeutic benefits of postoperative cisplatin and vindesine chemotherapy.

Adenocarcinoma↗

[Multidisciplinary treatment of advanced invasive thymoma].

From February 1988 to September 1992, six patients with Stage III or IV invasive thymoma were enrolled onto our study of multidisciplinary treatment, which included chemotherapy, surgery, and radiotherapy. The chemotherapy consisted of cisplatin (20 mg/m2 continuous 24-hour infusion on days 1 through 4), doxorubicin (40 mg/m2 on day 1), and methylprednisolone (1,000 mg on days 1 through 4 and 500 mg days 5 and 6). Two patients received surgery (incomplete resection) and postoperative chemo/radiotherapy, and four patients received induction chemotherapy followed by surgery and chemo/radiotherapy. All patients with induction chemotherapy showed a partial response and underwent complete (n = 2) or partial (n = 2) resection. Four patients are alive with no evidence of disease for 31 to 55 months after the diagnoses. But two with partial resection after chemotherapy died of recurrent disease. Multidisciplinary treatment including chemotherapy may be a new therapeutic choice in management of advanced invasive thymoma.

Adult↗

[Effect of enflurane on human somatosensory evoked potentials: differences between specific and nonspecific responses].

The effect of enflurane on somatosensory evoked potentials (SEP) was investigated in nine gynecological patients under nitrous oxide-enflurane anesthesia. SEPs were obtained from electrodes placed on the scalp C4 and earlobes by median nerve stimulation contralateral to the recording site. SEPs taken in a control study without enflurane consisted of six components; P12, N17, P23, N31, P50, and N65. Components N17, P23, N31, and P50, thought to be specific SEP responses, showed a dose-dependent increase in latencies under enflurane while P12, the initial SEP components, did not show any significant changes throughout the experiment. The longer the latency for a given response component, the greater was the increase in latency seen under enflurane anesthesia. On the other hand, N65, assumed to be a nonspecific SEP response, was completely lost with inhalation of 0.5 MAC or more of enflurane. However, the peak-to-peak amplitude between P23 and N31 was enhanced dose-dependently with enflurane up to 1.5 MAC. These results suggest that, at clinically effective doses, enflurane may inhibit nonspecific projection pathways while enhancing the primary cortical sensory area, and this enhancement may be responsible for provoking convulsive seizures under enflurane anesthesia.

Adult↗

Possible effect of pigment on the pharmacokinetics of ofloxacin and its excretion in hair.

The mechanism of excretion of the antimicrobial ofloxacin in human scalp hair was investigated. When black and white hairs were taken from a patient with grizzled hair, who had been treated with ofloxacin, a much larger quantity of the drug was detected in the black hair. To study this difference and to elucidate the cause, ofloxacin (6, 20, and 60 mg/kg/day, b.i.d.) was administered ip for 5 weeks to albino and pigmented rats, whose backs had been depilated beforehand. In the last week of administration, the time-plasma concentration profile of ofloxacin was determined. One week after the last dosing, the newly grown hair on the depilated area was collected, and the drug concentration in hair was measured. The concentration in hair of the pigmented rats correlated significantly with the daily dose, area under the plasma concentration curve (AUC), and maximum plasma concentration (Cmax) at steady state, whereas that in the albino rats correlated with the dose and Cmax only, because AUC did not increase linearly with the dose in the albino rats. Moreover, the drug concentration in the hair of the pigmented rats was always much larger than that in the hair of the albino ones, although AUC and Cmax did not differ greatly between both rat groups. The findings suggest that ofloxacin is excreted in the hair in relation to the dose administered, and that the mechanism of the excretion is closely linked with the presence of melanin.

Animals↗

Phase II study of cisplatin as a 5-day continuous infusion with vindesine plus recombinant human granulocyte-colony-stimulating factor in the treatment of advanced non-small-cell lung cancer.

A total of 36 patients with advanced non-small-cell lung cancer (NSCLC) were treated with a combination of 5-day continuous i.v. infusion of cisplatin (25 mg/m2 daily), bolus infusion of vindesine (3 mg/m2) on days 1 and 8, and s.c. injection of recombinant human granulocyte-colony-stimulating factor (2 micrograms/kg daily) on days 6-21. Treatment was repeated every 3-4 weeks. Responding patients with stage IIIA or IIIB disease received chest radiation therapy (50-60 Gy) after this treatment. One complete response and 23 partial responses were observed, for an overall response rate of 66.7% (24/36; 95% confidence limits, 51.3%-82.1%). The median duration of response was 5.7 months and the median overall survival was 10.1 months. WHO grade 3 or 4 leukopenia and neutropenia occurred in 22 (61%) and 27 (75%) patients, respectively, but the mean duration of leukopenia (< 2,000/mm3) and neutropenia (< 1,000/mm3) was 3.4 and 3.5 days, respectively, and there was no instance of life-threatening infection. Thrombocytopenia and anemia of grade 3 or 4 occurred in 28% and 36% of our subjects, respectively. Grade 2 nausea and vomiting occurred in 47% of the patients. Elevated serum creatinine levels (> 1.5 mg/dl) were observed in 3 (8%) of the 36 patients. One patient died of acute renal failure induced by hemorrhage of a gastric ulcer. This regimen is effective in the treatment of NSCLC and further studies of this combination are warranted.

Actuarial Analysis↗

Invasive thymoma with intracaval growth into the right atrium.

We report an unusual case of invasive thymoma with intracaval growth into the right atrium. Computed tomography and venacavography demonstrated this manner of extension of thymoma. The tumor was completely removed by means of cardiopulmonary bypass after four courses of chemotherapy. Multidisciplinary treatment for invasive thymoma with this growth pattern is thought to be useful.

Aged↗

Analysis of ofloxacin in hair as a measure of hair growth and as a time marker for hair analysis.

The distribution of ofloxacin (OFLX) along a single hair shaft was analyzed in detail for use as an index of hair growth and as a time marker for drug analysis in hair. A single hair obtained from each of seven subjects, who had taken OFLX for 1-4 days (total of 200-1,200 mg) 2.7-5.3 months before hair sampling, was cut into 1-cm-long portions successively from its scalp end. OFLX in each hair portion was measured by high-performance liquid chromatography with a fluorescence detector, and the distance from the scalp end of the hair portion containing OFLX was determined. Then the other 2-cm long segment of hair, which had the above-determined distance at its middle, was cut successively into 2-mm-long pieces and OFLX was determined in each piece. This procedure was repeated in a total of three to four hair strands collected from one subject. OFLX was observed to distribute only in one to three consecutive 2-mm-long pieces of hair, showing no large diffusion of OFLX along the hair shaft with time. Therefore, OFLX distribution may serve as a time marker for analyzing other drugs in hair. Hair growth rate could be thus estimated and ranged from 0.99 to 1.27 cm/month (1.12 +/- 0.11 cm/month, mean +/- SD) among individuals. The intraindividual variability of hair growth rate was 4.8-18.1% (10.3 +/- 5.1%) as coefficient of variation.

Adult↗

[A case of pulmonary metastasis from carcinosarcoma of uterus with subcutaneous implantation of tumor cells along the needle tract after percutaneous needle biopsy of lung].

A 68-year-old female who had undergone total hysterectomy for carcinosarcoma five months previously was noted to have a solitary nodular shadow in the right lung on chest X-ray. Percutaneous needle biopsy of the lung was performed via the right anterior chest wall, and the histologic findings showed metastasis from carcinosarcoma of uterus. Two months after needle biopsy, a chest wall mass appeared of the site of puncture of the lung needle biopsy. The mass was resected to relieve the chest wall pain and the specimen showed carcinosarcoma of uterus histologically. We consider that tumor cells were implanted to the chest wall along the needle tract after percutaneous needle biopsy of the lung. The postoperative chest computed tomogram showed the route of tumor implantation from the metastasis of right lung into the right chest wall. Dissemination and chest wall implantation of malignant cells after percutaneous lung needle biopsy have been rarely reported. However there are no reports of tumor implantation of sarcoma. The possibility of implantation of tumor cells along the needle tract after percutaneous lung needle biopsy should be carefully considered in cases of carcinosarcoma.

Aged↗