[Subchronic oral toxicity study of cyanoguanidine in F344 rats]

A 13-week subchronic oral toxicity study of cyanoguanidine was performed in male and female F344 rats by feeding of CRF1 powder diets containing 0, 1.25, 2.5, 5 and 10% cyanoguanidine to determine appropriate dose levels for a subsequent 2-year carcinogenicity study. The rats were randomly allocated to 5 groups, each consisting of 10 males and 10 females. No animals died during the administration period. Inhibition of body weight gain was more marked in both sexes of the 10% group and in females of the 5% group as compared with the control group. Mean food intake in males of the groups treated with 5% or 10% and in females of the 10% group was significantly higher than that in the control group. Serum biochemical investigation revealed a higher level of serum BUN in both sexes of the 10% group. On histopathological examination, toxic changes characterized by the occurrence of intranuclear eosinophilic inclusion bodies in the proximal tubular epithelium of the kidney were observed in both sexes of the 10% group. Similar inclusion bodies were also seen in 2 out of 10 males of the 5% group. From these results, it was concluded that a level of 10% of cyanoguanidine in the diet is unequivocally toxic. A dose level, 5% cyanoguanidine, in the diet might be appropriate as a high dose for a carcinogenicity study.

Subglottic plasma cell granuloma: report of a case

A case of subglottic and tracheal plasma cell granuloma masquerading as tumor invasion by thyroid malignancy was successfully treated using CO2 laser. A 55-year-old woman with a history of inspiratory stridor of almost 10 months duration was admitted to our clinic, and examinations revealed a mass in the subglottic space and trachea obstructing the airway. CT scan findings was suggestive of tumor invasion from a thyroid gland malignancy, however, histopathological examination of a biopsy specimen showed it to be plasma cell granuloma. Cases of plasma cell granuloma of the larynx and trachea are reviewed and discussed.

Induction of hepatocyte mitosis in intact adult rat by interleukin-1 alpha and interleukin-6

In the adult rat the liver is normally quiescent, but it proliferates rapidly in response to partial hepatectomy (PH). A hepatectomized rat is subjected to stress by the operation. We have examined the effects of acute phase cytokines. To investigate the mediation of hepatocyte growth, recombinant human interleukin-1 alpha (IL-1) and interleukin-6 (IL-6) were injected into male rats. Administration of IL-1 or IL-6 followed by NH4Cl and glucagon could induce hepatocyte mitosis 30 h after the first injection. This activity was lost when interleukins were exposed to 90 degrees C for 30 minutes. NH4Cl augmented the effects of IL-1 and IL-6. These results suggest that the IL-1 and IL-6 are important mediators of liver regeneration after PH. We present a hypothesis for the triggering mechanism of hepatocyte proliferation.

Hydrogen peroxide generation by eosinophils in allergic rhinitis

It was the aim to study the hydrogen peroxide (H2O2) generation by eosinophils in allergic rhinitis caused by house dust which was examined in nasal secretion and peripheral blood. The concentration of H2O2 in nasal secretions was increased after nasal challenge with house dust, and subsided gradually by the increase of peroxidase activity. The population of eosinophils and H2O2 generation which was morphologically detected on the plasma membrane of eosinophils in nasal secretion, were increased with the release of eosinophil chemotactic activity after nasal challenge. Also, in peripheral blood, the number and phagocytic activity of eosinophils in extremely high density 1.102 g/ml were increased after nasal challenge. A high number of eosinophils was found in a density of 1.097 g/ml in the high IgE group, but showed less phagocytic activity than in the lower IgE group. Considering from these findings, H2O2 generation by eosinophils appeared to be an important event in tissue injury and augmentation of allergic reaction.

Spontaneous uterine adenocarcinomas in aged rats and their relation to endocrine imbalance

In addition to spontaneous uterine endometrial adenocarcinomas at a high incidence (35.1%), development of endometrial hyperplasia/adenoma was also frequently detected in rats of the Donryu strain. The total yield of all observed proliferative endometrial lesions was very high (60.6%). The tumors arose commonly in the uterine horn of aged rats. Histologically, most demonstrated glandular structures, consisting of cuboidal or columnar cells with weak eosinophilic or basophilic cytoplasm and large nuclei. In about half of the animals with adenocarcinomas, metastasis to remote organs such as the lung was observed. Histological examination of the ovary and vaginal epithelium revealed ovarian cysts, atrophy of the ovary and cornification of the vaginal epithelium more frequently in rats with endometrial carcinomas than in animals without tumors. These findings indicate that adenocarcinoma development in Donryu rats is associated with endocrine imbalance [increased serum estrogen: progesterone (E2:P)ratios]. By comparative investigation of strain differences, it was confirmed that irregular estrous cycles began earlier with higher incidence in Donryu rats than in F344 rats, a low-incidence strain. Histological findings of the ovary and vaginal epithelium also suggested relatively increased estrogen levels in Donryu rats compared to F344 rats. Estimated plasma values of gonad steroids showed that the E2:P ratio in Donryu rats at 12 months of age was about five times that in F344 rats. These results therefore indicate that hormone imbalance, particularly an increased E2:P ratio, may play an important role in the spontaneous occurrence of endometrial adenocarcinoma in Donryu rats.

High yields of granulosa cell tumors/luteomas in F344 rat ovaries after transplacental administration of N-nitrosobis(2-oxopropyl)amine

Ovarian tumors were induced at very high incidence in the offspring of F344 rats receiving 3 subcutaneous injections of 10 mg/kg of N-nitrosobis(2-oxopropyl)amine on the 14th, 18th and 20 days of gestation. Histologically, all ovarian tumors were of the granulosa cell tumor and/or luteoma type. Many of them consisted of large, polygonal cells with abundant eosinophilic or vacuolated cytoplasm, arranged in sheets or in a pseudo-palisaded pattern separated by thin fibrovascular stroma, and they exhibited typical luteoma morphological character. The high yields, and the similarities in morphology as well as putative hormonal influence suggest that this experimental system may serve as a good animal model for granulosa cell tumor and/or luteoma development in women.

[Anesthetic management of a patient with Sjögren's syndrome and pulmonary fibrosis]

We described an anesthetic management of a 63 year old man complicated with Sjögren's syndrome and pulmonary fibrosis. Sjögren's syndrome is characterized by pathological dryness of the mouth, cornea and other exocrine glands. Anesthesia was induced with thiopental and the trachea was intubated smoothly following intravenous succinylcholine. Anesthesia was maintained with enflurane in nitrous oxide and oxygen. Intraoperative muscle relaxation was adequately obtained by pancuronium. Before and during anesthesia, atropine and other drying agents were avoided. Physiological saline solution was instilled on the eyes every ten minutes against dryness. A heat and moisture exchanger (Humi-Vent) was used to maintain high moisture of the respiratory tract. Anesthesia was carried out successfully.

A novel model of solitary hepatic tumor in rats using ascites hepatoma AH13: suitability for chemotherapeutic studies

A highly reproducible model of a solitary hepatic tumor in rats using ascites hepatoma AH13 has been developed using a two-step method which was suitable for quantitative chemotherapeutic studies. Diffuse hepatic metastases were induced first by inoculation of three different ascites hepatomas, AH13, AH130 and AH7974 into the portal vein in a dose-dependent fashion. Second, the induced hepatic tumor (3 x 10(7) cells) was minced into 1 x 1 x 4 mm fragments and implanted in the liver of normal rats. In this procedure, the AH13 strain proved best suited for the generation of a solitary hepatic tumor. The growth of the solitary liver tumor using AH13 was highly reproducible. To demonstrate the suitability of this solitary hepatic tumor model for the evaluation of chemotherapy, the tumor-burdened rats were treated with adriamycin (ADR) and mitomycin C (MMC). The reduction in tumor size was proportional to dosage, and the statistical significance of the differences between the treatment group and control group was proportional to dosage. A synergistic effect of ADR and MMC on the tumor also was demonstrated. This model should prove to be a useful tool for the testing of newly developed treatments of hepatic cancer.

[Anesthetic experience of a patient with blue rubber bleb nevus syndrome]

We report an anesthetic experience of a 63-year-old female patient with blue rubber bleb nevus syndrome who underwent an open reduction of the fracture of the right femur. The syndrome is characterized by bluish nevus scattered throughout the skin of the whole body and angiomas of the gastrointestional tract causing serious bleeding. Anesthesia was induced with thiopental followed by intravenous injection of succinylcholine chloride and maintained with neuroleptanesthesia in nitorous oxide and oxygen. The course of anesthesia and emergence from anesthesia were uneventful. Anesthetic management of patients with blue rubber bleb nevus syndrome was also discussed.

Long-term toxicity/carcinogenicity of musk xylol in B6C3F1 mice

The long-term toxicity/carcinogenicity of musk xylol, a synthetic nitro musk, was examined in B6C3F1 mice of both sexes. Musk xylol was administered at dietary levels of 0 (control), 0.075 or 0.15% for 80 wk. The overall tumour incidences in all treated groups of both sexes were significantly higher than those in the corresponding controls. Combined malignant and benign liver cell tumours were clearly increased in both sexes, and in males a positive significant trend was also noted for the occurrence of hepatocellular carcinomas. In males the incidence of Harderian gland tumours was also significantly greater in treated groups than in controls. Some other neoplasms, such as lung tumours in both sexes and Harderian gland tumours and lymphomas in females, occurred in greater numbers in the treated groups, although the differences were not statistically significant in comparison with the controls. In addition, the incidences and total numbers of malignant tumours were significantly increased in treated groups of both sexes, although the increases were not dose dependent. The results demonstrated that musk xylol is carcinogenic in B6C3F1 mice when given at dose levels of 0.075 or 0.15% in the diet for 80 wk.

[The effect of IL-2 injection around the metastatic cervical lymphnode]

Six patients with squamous cell carcinoma of head and neck were treated with injection of interleukin-2 (IL-2) around the metastatic cervical lymphnodes. Lymphokine activated killer (LAK) activity in peripheral blood in administration of IL-2 showed a significant high of 13.2% at effector/target (E/T) ratio 13 compared with non-administration of IL-2 showed 4.3%. LAK activity in cervical non-metastatic lymphnodes in 6 cases of administration of IL-2 showed a significant high of 23.0% at E/T ratio 50 compared with 3 cases of non-administration of IL-2 which showed 3.7%. In the 2 evaluable courses given in patients a partial response was obtained in one case.

[Plasma cortisol levels during abdominal surgery under sevoflurane anesthesia: comparison between gastrointestinal and gynecological surgery]

Plasma cortisol levels during abdominal surgery under sevoflurane anesthesia were evaluated in 22 patients who ranged in ages from 37 to 65. They underwent either gastrointestinal or gynecological abdominal surgery. Anesthesia was induced and maintained with sevoflurane (1-5%) in nitrous oxide (4 l.min-1) and oxygen (2 l.min-1). Succinylcholine was administered intravenously to facilitate tracheal intubation and pancuronium was given intravenously during surgery. Lactated Ringer's solution at a speed of 10-15 ml.kg-1.hr-1 was also administered intravenously throughout the surgical procedures. Plasma cortisol levels were unchanged with the induction of sevoflurane anesthesia alone, but they increased significantly 2-3 times of the preanesthetic levels during and after surgery in both groups. However, the concentrations of plasma cortisol after recovery from anesthesia were significantly higher in the gastrointestinal group than in the gynecological group. The findings suggest that plasma cortisol levels after surgery reflect the difference in magnitude of stress response between gastrointestinal and gynecological surgery.

[Sevoflurane anesthesia for a patient with arthrogryposis multiplex congenita]

We reported an anesthetic experience of a 6-year-old male patient with arthrogryposis multiplex congenita who underwent tonsillectomy and adenoidectomy. The induction and maintenance of anesthesia were smoothly performed with inhalation of 1-5% sevoflurane in nitrous oxide and oxygen. Emergence from anesthesia was also smooth. Halothane and succinylcholine chloride were not used to avoid possible hyperthermia. Anesthetic management of patients with arthrogryposis multiplex congenita was discussed citing literature references.

[Difference in the therapeutic efficacy between anaplastic astrocytoma and glioblastoma multiforme types]

We have investigated the differences in therapeutic efficacy between 25 cases with an anaplastic astrocytoma (AA group) and 31 cases with a glioblastoma multiforme (GM group). A good response to induction therapy was achieved with radiation and nitrosourea after a (sub) total removal that led to a prolonged tumor-free interval that was remarkable in the AA group, especially in those with moderate anaplastic astrocytoma. On the other hand, in the GM group, early recurrence tended to occur with no correlation to the degree of the tumor resection, and this made the execution of the maintenance therapy difficult in spite of a similar response to the initial induction therapy as that seen in the AA group.

Inhibition of angiogenesis by bleomycin and its copper complex

The effects of bleomycin (BLM) and its copper complex on embryonic angiogenesis were studied in the chorioallantoic membranes of 4.5-day-old chick embryos. Copper-free BLM inhibited embryonic angiogenesis in a dose-dependent manner, with activity detectable at 1 ng/egg and maximal at 1000 ng/egg. Also, treatment with copper-BLM complex dose-dependently caused inhibition of embryonic angiogenesis in a lower dose range. Since tumor growth is believed to depend on angiogenesis, the present results may indicate that the antiangiogenic activity of BLM is, at least in part, implicated in the antitumor activity of the drug.

Two-year carcinogenicity study of 6-mercaptopurine in F344 rats

The carcinogenicity of 6-mercaptopurine (6-MP), an anticancer drug, was examined in F344 rats of both sexes, administered the chemical at dietary levels of 0 (control), 25 ppm or 50 ppm for 2 years. Many tumors developed in all groups including the control group, the organ distribution and histological types being similar to those reported for spontaneous lesions. In males, there was no significant increase in the incidence of any tumor in the treated groups over that in the control group. In females, however, positive trends were noted in the occurrence of C-cell tumors, pheochromocytomas, uterine adenocarcinomas and gliomas, and the incidences of C-cell tumors and pheochromocytomas in the 50 ppm group were significantly higher than the values in the respective control group. In addition, the total numbers of malignant tumors increased significantly in the female 50 ppm group. However, most of the tumors demonstrating increase are frequently observed spontaneous lesions in this strain of rats, and their incidences in the present female control group were lower than in our historical data. In addition, there were no significant differences in the incidences of preneoplastic changes and induction times for the above-listed tumors between the female control and the 50 ppm groups. These results thus indicated that while the carcinogenic potential of 6-MP can not be precluded, it can be only very weak or marginal, after continuous administration in the diet at the 50 ppm level for 2 years. The leukemogenic action of 6-MP was negative under the present experimental conditions.

[Etoposide delivery to malignant brain tumors by induced hypertension with angiotensin II]

Etoposide delivery to 9L gliosarcoma model in Fischer 344 rats was evaluated. Etoposide 2 mg/body was given intravenously (IV) or intracarotidly with (IHIC) or without (IC) intravenously administrated angiotensin II. Mean etoposide concentration of tumors was 5.08 micrograms/g for IHIC group, 2.27 micrograms/g for IC group and 0.70 micrograms/g for IV group. The difference in etoposide concentration between IHIC group and IV group was statistically significant (p less than 0.05). In addition, etoposide concentrations of the normal brain tissues were lower than concurrent plasma concentrations in all groups. The etoposide concentration was increased in the tumor and very low in the normal brain tissues in Fischer 344 rats with 9L gliosarcoma by induced hypertension with angiotensin II. These studies might suggest that intraarterial chemotherapy by induced hypertension with angiotensin II was useful on treatment of malignant brain tumors.

Lack of toxicity/carcinogenicity of monosodium succinate in F344 rats

The toxicity/carcinogenicity of monosodium succinate, a food additive, was examined in F344 rats. The oral LD50 was greater than 8 g/kg body weight. In a 13-wk subchronic oral toxicity study, the only toxicological finding was suppression of body-weight gain in groups given greater than or equal to 2.5% monosodium succinate in the drinking-water. Histological examination revealed no toxic lesions specifically caused by the compound in any organs of any of the treated rats. The maximum tolerated dose was determined to be 2-2.5% on the basis of body-weight depression. In a long-term (2-yr) toxicity/carcinogenicity study, monosodium succinate was given ad lib. in drinking-water (distilled water) at levels of 0, 1 or 2% to groups of 50 male and 50 female rats. No toxic lesion specifically caused by long-term administration of monosodium succinate was detected. No dose-related increase was found in the incidences of tumours in any organ or tissue except for C-cell tumours of the thyroid gland of females. The incidence of these tumours in females given the 2% dose was higher than that in controls but not significantly so, and a positive trend for this tumour was noted in females. C-Cell tumour is one of the most commonly observed spontaneous tumours in ageing female rats of this strain and occurs at a variable incidence. There was no difference between the female control and treated groups in the incidence of preneoplastic change of the thyroid gland. Furthermore, the incidence of C-cell tumours in the female control group was lower than that in our historical controls. It is concluded that the increase in C-cell tumours in the female high-dose group and the detection of a positive trend for this tumour in females were probably a function of experimental variability and were not related to treatment. The results indicate that monosodium succinate had neither toxic nor carcinogenic activity in F344 rats when it was given continuously at levels of 1 or 2% in the drinking-water for 2 yr.

[Sevoflurane anesthesia for a patient with cerebral palsy]

We report anesthetic management of a 20-year-old male patient with cerebral palsy who underwent an operation for retinal detachment of the left eye. Induction and maintenance of anesthesia were smoothly done with inhalation of 1-5% sevoflurane with nitrous oxide and oxygen. Emergence of anesthesia was also smooth except for slight and transient excitement. Anesthetic management of a patient with cerebral palsy was also discussed.

Inhibition of angiogenesis by vitamin D3 analogues

The effects of vitamin D3 and two analogues on embryonic angiogenesis were studied in 4.5-day-old chick embryo chorioallantoic membranes. The active metabolite of vitamin D3, 1 alpha,25-dihydroxyvitamin D3, and a synthetic vitamin D3 analogue, 22-oxa-1 alpha,25-dihydroxyvitamin D3, inhibited angiogenesis in a dose-dependent manner, the inhibition occurring in the picomolar range. In contrast, vitamin D3 was not effective. The results suggest that these two vitamin D3 analogues might be promising anti-angiogenic agents for controlling the angiogenesis which occurs in several pathological conditions, including tumor development.

Multiple oligodendroglioma--case report

A 32-year-old male was hospitalized with headache and disturbance of consciousness. Computed tomography (CT) revealed a tumor and an intracranial hematoma in the right frontal lobe. The tumor was totally removed, and postoperative radiation therapy was administrated locally at 50 Gy. Five years later, he experienced sudden onset of headache and vertigo. CT demonstrated a mass lesion with a hematoma in the cerebellar vermis. The tumor was subtotally removed and he underwent postoperative local irradiation at 50 Gy as well as ventriculoperitoneal shunting. Four years later, he complained of visual and gait disturbances, and CT disclosed a tumor in the suprasellar region. Following partial removal of the tumor, local brain irradiation was given at 40 Gy. Histological examination proved all three tumors to be oligodendrogliomas with no evidence of malignant change.

[Subchronic oral toxicity study of tannic acid in F344 rats]

A 13-week subchronic oral toxicity study of tannic acid (TA) was carried out in F344 rats at dose levels of 0, 0.025, 0.05, 0.1, 0.2 and 0.4% in the drinking water, to determine appropriate dose levels for a subsequent 2-year carcinogenicity study. The rats were randomly allocated to 6 groups, each consisting of 12 males and 12 females. No animals died during the administration period. There were no significant difference in body weight gain, food consumption and organ weights between the treated and control groups, although a slight decrease in water intake was seen in the 0.4% TA treated group. No specific changes were observed in any parameters in the hematological and biochemical investigations. Histopathological examination, revealed toxic changes in the TA treated male groups, in the form of necrosis in the liver, but toxicologically it was of minor importance. From these results, it was concluded that the provable maximum tolerable dose of TA in the drinking water would be more than 0.4%. In consideration of the avoidance of drinking water, the maximum tolerable dose of tannic acid was determined to be 0.5%, when given in the drinking water.

Antitumor effect of combination of murine recombinant interferon beta, murine recombinant interferon gamma and human recombinant interleukin-2 in MethA-bearing mice

We have previously reported that the combination of murine recombinant interferon beta (Mu-rIFN beta) with murine recombinant interferon gamma (Mu-rIFN gamma) provided greater inhibition of tumor growth than did each one alone in MethA-bearing mice. In the present study the effect of addition of human recombinant interleukin-2 (Hu-rIL-2) to the combination of Mu-rIFN beta with Mu-rIFN gamma on tumor growth in BALB/c mice bearing syngeneic MethA fibrosarcoma was examined. Low doses of Hu-rIL-2 (5 x 10(3) U or 5 x 10(4) U at 3-day intervals) showed no antitumor activity, while a high dose of Hu-rIL-2 (5 x 10(5) U) showed profound growth inhibition. The administration of IL-2 (ranging between 5 x 10(3) U and 5 x 10(5) U) in addition to the combination of IFN beta and IFN gamma showed more augmented antitumor effects in a dose-dependent manner. Furthermore, the simultaneous administration of IL-2, IFN beta and IFN gamma had more effective therapeutic activity, compared with the sequential administration of interferons and IL-2. These findings indicated that IL-2 in combination with IFN beta and gamma was effective for cancer treatment.