A 13-week subchronic toxicity study of hinokitiol administered in the diet to F344 rats.

Myocarditis has been reported in male F344 rats given a diet containing hinokitiol (HT). A subchronic toxicity study was here performed to re-evaluate toxic effects of HT in both sexes of F344 rats with dietary administration at concentrations of 0%, 0.02%, 0.07% and 0.2% for 13 weeks. Significant reduction of body weight gain was noted in 0.2% males and 0.07% and above females. Significant decrease in RBC counts, hemoglobin and hematocrit was detected in 0.07% and 0.2% females. Significant increase in MCV was observed in 0.07% and above males and 0.2% females. In the rats given 0.07% and 0.2%, significant increase in total protein and albumin were detected in males, and in total cholesterol in females. Significant increases in total cholesterol, urea nitrogen and creatinine were also detected in the 0.2% males. Significant increase in relative liver weights was detected in the 0.07% and above males and females. Absolute and relative heart weights were significantly decreased in the 0.07% and above males. Based on the above findings the no-observed-adverse-effect level (NOAEL) of HT for both male and female rats was estimated to be 0.02%, translating into 12.7 and 14.8 mg/kg b.w./day, respectively. Myocarditis was not evident in the present study.

A 13-week subchronic toxicity study of dietary administered saponin-rich and isoflavones-containing soybean extract in F344 rats.

A subchronic toxicity study of soybean extract was performed in F344 rats with dietary administration at concentrations of 0%, 1.25%, 2.5% and 5% for 13 weeks. No mortality or abnormal clinical signs in any group were observed. Body weight gains were decreased with a tendency for reduction of feed intake in the 1.25% and above female and 5% male groups. In males, absolute and relative liver weights were increased in the 1.25% and above groups. In females relative kidney weights were increased in the 1.25% and above groups. Other significant changes such as decreased RBC and hematocrit and increased urea nitrogen were detected in the 2.5% and/or 5% groups. On histopathological observation, atrophy of the ventral prostate was observed in all animals in the 5% male group. Mucification and atrophy of the vaginal epithelium and increased atretic follicles in ovaries were noted in 2.5% and 5% female rats. Based on the above findings the lowest-observed-adverse-effect level for male and female rats was estimated to be 1.25% (707.2 and 751.8 mg/kg b.w./day, respectively).

Evaluation of toxicity of green tea catechins with 90-day dietary administration to F344 rats.

Green tea catechins (GTC), polyphenols extracted from the stalks and leaves of Camellia sinensis, are found in the different types of tea beverages and as antioxidant additives to many foods, snacks, fats and fatty oils. As a part of their safety assessment, subchronic toxicity was investigated in male and female F344 rats with dietary administration at concentrations of 0 (control), 0.3%, 1.25% and 5.0% for 90 days. The average daily intakes of GTC in each group were 180, 764 and 3525mg/kg body weight/day, respectively for males, and 189, 820 and 3542mg/kg body weight/day, respectively for females. No mortality or obvious clinical signs were observed throughout the experimental period but body weights were reduced from week 1 to the end of the experiment in 5.0% males. In serum biochemistry, alanine transaminase and alkaline phosphatase in 5.0% males and females and aspartate transaminase in 5.0% females were increased, together with the relative liver weights in both sexes receiving 5.0%. Although decreases were evident for total cholesterol in 0.3-5.0% males and triglycerides in 1.25% and 5.0% males and 5.0% females, these changes were not considered to be adverse. Hematology and histopathological observation revealed no GTC-related toxicological changes. Based on above findings, the no observed adverse effect level (NOAEL) of GTC was estimated to be 1.25% (764mg/kg body weight/day for males and 820mg/kg body weight/day for females).

Chronic toxicity and carcinogenicity of dietary administered ammonium sulfate in F344 rats.

Chronic toxicity and carcinogenicity studies of ammonium sulfate, used as a food additive in fermentation, were performed in male and female Fisher 344 rats at dietary concentrations of 0%, 0.1%, 0.6% and 3.0% in a 52-week toxicity study and 0%, 1.5% and 3.0% in a 104-week carcinogenicity study. Treatment with ammonium sulfate caused significant increase in kidney and/or liver weights in males and females of the 3.0% diet group, but no effects were found on survival rate, body weights, and hematological, serum biochemical or histopathological parameters at any dose levels in the chronic toxicity study. Regarding carcinogenicity, ammonium sulfate did not exert any significant influence on the incidences of tumors in any of the organs and tissues examined. It was concluded that the no observed adverse effect level of ammonium sulfate was the 0.6% diet, which is equivalent to 256 and 284 mg/kg b.w./day in males and females, respectively, and the compound is non-carcinogenic under the conditions of the study.

Promotion of thyroid carcinogenesis by para-aminobenzoic acid in rats initiated with N-bis(2-hydroxypropyl)nitrosamine.

Sulfonamide analogues of para-aminobenzoic acid (PABA), a precursor of folate synthesis, have beneficial effects as antifolate, but thyroid peroxidase inhibition has been reported as a side effect that results in promotion of rat thyroid carcinogenesis. In the present study, effects of PABA itself on F344 rat thyroid carcinogenesis after initiation with N-bis(2-hydroxypropyl)nitrosamine (DHPN) were evaluated. In experiment 1, rats in groups 1-4 received a single subcutaneous injection of DHPN at 2800 mg/kg, and groups 5 and 6 received vehicle saline alone. From 1 week after DHPN initiation, rats in groups 2, 3, 4, and 6 were fed basal diet containing 0.25%, 0.5%, 1.0%, and 1.0% PABA, respectively, for 40 weeks. Rats in groups 1 and 5 received basal diet alone throughout the experiment. The final incidence of thyroid follicular cell adenomas and adenocarcinomas was significantly (p < 0.05 or 0.01) increased in groups 3 and 4 as compared to group 1. No thyroid tumors were found in groups 5 and 6. In experiment 2, animals in group 1 were fed basal diet alone, while groups 2 and 3 were given 0.5% and 1.0% PABA in the diet, respectively, for 2 weeks. Thyroid weights in group 3, and serum thyroid stimulating hormone level and proliferative activity of follicular cells in groups 2 and 3 were significantly (p < 0.05 or 0.01) elevated. In addition, the serum thyroxine level in group 3 was significantly (p < 0.05) depressed. These results clearly indicate that PABA exerts promotion/progression effects on rat thyroid carcinogenesis as a result of hypothyroidism followed by negative-feedback via the thyroid-pituitary axis.

Evaluation of the toxicity of enzymatically decomposed rutin with 13-weeks dietary administration to Wistar rats.

The subchronic toxicity of enzymatically decomposed rutin, which consists mainly of isoquercitrin, was investigated in male and female Wistar rats with dietary administration at concentrations of 0, 0.2, 1 and 5% for 13 weeks. No mortality or abnormal clinical signs were observed throughout the experimental period in any groups. Body weight gain was reduced from week 10 to the end of the experiment in the 5% dosed males as compared to the 0% controls. Decreased erythrocytic parameters, i.e. red blood cell count, hemoglobin concentration and hematocrit, and significantly lowered serum triglyceride levels were also detected in the 5% males. Organ weight measurement, macro and microscopic observation revealed no test substance-related toxicological changes. Based on the above findings, no-observed-adverse-effect levels (NOAELs) for male and female rats were estimated to be 1 and 5%, respectively, translating into 539 and 3227 mg/kg b.w./day.

[Cerebral malformations associated with probable intrauterine infection].

An autopsy case with various cerebral malformations was studied and discussed on the pathogenesis. The patient was a 17-year-old female who developed tonic seizures around the age of 1 month and was treated under a diagnosis of infantile spasms. A CT scanning revealed agenesis of corpus callosum, subtentorial arachnoid cyst and brain atrophy. Neuropathologically multiple malformations were observed in the brain, polymicrogyria, pachygyria, cerebral gray matter heterotopia, partial agenesis of corpus callosum, hypoplasia of cerebellar vermis and arachnoid cyst. The most remarkable finding was chronic inflammation represented by infiltration of lymphocytes and foamy macrophages, fibrosis and vascular hyalinization in the arachnoid membrane as well as in the choroid plexus of the third ventricle. Proliferation of astrocytes with intracytoplasmic eosinophilic inclusions was also found in the areas of polymicrogyria and heterotopia. The infratentorial cyst was walled by scarring cerebellar tissue with a focal inflammation which was probably caused by an encephaloclastic process. The diversity in these cerebral malformations suggests that etiology might be polyphasic in time and infectious in nature during the intrauterine period of cerebral development.

[A case of an cerebello-pontine angle pineoblastoma].

An extremely rare case of a left cerebello-pontine angle (CP angle) pineoblastoma has been reported. The patient was a 32-year-old male whose initial manifestations were those of increased intracranial pressure. CT scan showed a large enhancing mass located at the left CP angle, associated with a moderate occlusive hydrocephalus. Left suboccipital craniectomy was performed. The mass was an extramedullary tumor which had compressed the left cerebellar hemisphere, and was easily separable from the adjacent tissue. The tumor was totally resected, and the patient had a temporary release from the symptoms. Recurrence and spinal dissemination were found within the ensuing few months. The tumor had invaded deeply through the left CP angle into the cerebellar parenchyme, and showed no anatomical connection with the pineal body. The tumor dissemination was also observed widely in the spinal subarachnoid space. No abnormalities at the pineal region were able to be confirmed using CT and MRI studies. Irradiation to the whole brain, to the localized left CP angle and to the spinal cord with additional chemotherapy was given. The patient died half a year after the first operation. Autopsy was not performed. Histopathologically, the tumor was delineated into lobular structures by reticulin fibrils and vimentin-positive interstitial tissue. Tumor cells were small in size, and had irregularly shaped hyperchromatic nuclei with increased mitotic figures, and formed various types of rosettes; pineocytomatous, Flexner-Wintersteiner, Homer-Wright and perivascular. Fine argyrophilic cell processes with club-shaped expansions were demonstrated inside the pineocytomatous rosettes.(ABSTRACT TRUNCATED AT 250 WORDS)

[Tyrosine hydroxylase-immunohistochemical study in the midbrain of experimental MPTP parkinsonism].

We have performed tyrosine hydroxylase (TH)-immunohistochemical study in the midbrain of experimental MPTP parkinsonism. Eight female adult crab-eating monkeys (macaca fascicularis) were subjected to the experiment and divided into four groups. In the acute experimental parkinsonism (group A), a daily dose of 1.3 mg/kg MPTP was given intravenously for 7 days. Monkeys in the subacute group B were injected every other day a dose of 1.0 mg/kg MPTP intravenously for 7-14 days. Chronic experimental parkinsonism group C was induced by administration of a dose of 0.5 mg/kg twice a week intravenously for 120 days. Group D served as a control. TH-immunoreactive cells were counted in substantia nigra pars compacta (SNc: consisting of lateral, intermediate, medial regions) and paramedian region of midbrain. The remaining TH-immunoreactive cells in group A,B and C were approximately 65.1%, 46.6% and 32.1% of the control group D. The ratio of TH-immunoreactive cells in the lateral region of group A, B and C was lower than in group D. The TH-immunoreactive ratio in the intermediate and medial region of group B and C was lower than in group D. In the medial region of group C, the TH-immunoreactive ratio was increased than in group B. In the paramedian region of all groups, there was no significant differences in the ratio of TH-immunoreactive cells, but many more TH-immunoreactive nerve fibers were observed in group B and C than in group A and D. From the 90th day after MPTP treatment, monkeys in group C began to show a gradual recovery from the flexed posture and hypokinesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Nuclear bodies in human autopsy prostate with special reference to appearance rate.

Nuclear bodies were observed in the nuclei of human prostatic epithelial cells at 2 to 3 hours post mortem. Although the epithelial cells of the autopsy cases revealed autolytic necrosis, the general feature of nuclear bodies were almost similar to those of fresh biopsied prostatic tissue. The nuclear body appearance rate was statistically analyzed in both secretory epithelial and basal cells of 3 different cellular condition areas (the hyperplastic nodule, non-nodule and atrophic). It was significantly high in the secretory epithelium of the hyperplastic nodule, but not in the other 2 areas. There was no significant result in the basal cells. The nuclear body appearance rate was statistically compared with that of human fresh biopsy cases previously reported by us (Furusato et al. 1986). The nuclear body appearance rates obtained in these 2 groups were not statistically different in each cell type and in 3 areas. The result suggests that the nuclear body appearance rate is reliable at 2 to 3 hours post mortem.

Two- and three-dimensional ultrastructure of endothelium and pericyte interdigitations in capillary of human granulation tissue.

Two- and three-dimensional electron microscopic observation in the immature capillary of the human granulation tissue revealed cytoplasmic interdigitations (CID) between the endothelium and the pericyte. These were composed of a cytoplasmic projection and indentation, and there was a gap space without basement membrane-like components between the two cell membranes. Plasmalemmal vesicles were frequently found locating beneath and/or attached to the cell membranes at the indentated side of the interdigitation. Two kinds of cytoplasmic interdigitation, each having a characteristic configuration, were demonstrated. The CID which was composed of a cytoplasmic projection from the endothelium to the pericyte had a dull-shaped cytoplasmic projection, while the CID which was composed of a cytoplasmic projection from the pericyte to the endothelium had a slender and long finger-like configuration.