[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.

Gene responsible for deficient activity of the beta subunit of C8, the eighth component of complement, is located on mouse chromosome 4

Sera from 73 strains of mice were tested for hemolytic activity through the classical and the alternative pathways (CP and AP) in a single radial hemolysis assay. Sera from 16 out of 45 laboratory inbred strains had no lytic activity, and Ouchterlony analysis with anti-C5 serum showed them to be C5-deficient. Sera from 2 out of 28 strains derived from wild mice also had no lytic activity, but the C5 molecule was detectable in both. The hemolytic activity of sera from these strains can be restored by the addition of partially purified human C8 or human serum deficient in C8 alpha-gamma, leading us to conclude that strains M.MOL-MSM (MSM) and Mae are deficient in the beta subunit of C8. Typing of (DBA/2J X MSM)F1 hybrids and of progeny of a backcross to MSM showed that this C8 deficiency is controlled by a single recessive gene, designated C8b; the allele with hemolytic activity is C8b1; and the allele with no activity C8b0. Because of synteny homologies in mouse and human, we looked for and found close linkage between C8b and Pgm-2. Typing of recombinant mice for Mup-1 mapped the C8b locus 2.3 centimorgans (cM) telomeric to Pgm-2 on mouse chromosome 4.

[Twenty-eight day repeated dose toxicity test of m-nitroaniline in F344 rats]

A twenty-eight day repeated oral dose toxicity test of m-nitroaniline (m-NA) was carried out in male and female F344 rats at dose levels of 0, 15, 50 or 170 mg/kg/day. Animals of both sexes were divided into 6 groups, each consisting of 30 animals, 4 groups being used for the 28 days dosing study and the remainder for investigation of subsequent recovery. Inhibition of body weight gain, and induction of cyanosis and methemoglobinemia were observed in the highest dose groups of both sexes, but there were no animal mortalities. Testicular atrophy was evident but there was no effect on the ovaries in the same group. In addition to these findings, hemolytic anemia and increases of liver, spleen and kidney weights were also observed in both sexes in a dose-related fashion. Histologically, the highest dose group showed reduction of spermatogenesis with multinucleated giant cell formation, lipofuscin deposition mainly in the proximal renal tubules, and increases in hemosiderin deposition and extramedullary hematopoiesis in the liver. Dose-related increases in the incidence of hemosiderin deposition in the spleen, erythroid hyperplasia in the bone marrow and swelling of hepatocytes were observed in treated groups. After a 14 day recovery period, these findings were attenuated or had disappeared. Based on these results obtained under the present experimental conditions, it was concluded that m-NA induces hemolytic anemia and exerts testicular toxicity in rats and that the non-observed-effect level of m-NA is less than 15 mg/kg/day.

Differential effects of endothelin-1 and big endothelin on canine kidneys

Renal effects of endothelin-1 (ET-1, human, 1-21) and the equivalent molar concentration of big ET (human, 1-38) and the contributions of prostaglandins and endothelium-derived relaxing factor to these actions were examined. Intrarenal infusion of ET-1, at a dose of 0.4 pmol/kg/min, decreased renal blood flow (RBF), glomerular filtration rate (GFR), and urine output (V) to 62, 70, and 45% of control values, respectively. Additional aspirin-DL-lysine (ASP) treatment (25 mg/kg) caused marked decreases in RBF, GFR, and V to 20, 14, and 9% of control values, respectively. During ET-1 infusion, intrarenal infusion of NG-monomethyl-L-arginine (L-NMMA, 1 mumol/min) caused decreases in RBF, GFR, and V. In another group, intrarenal infusion of big ET at a dose equivalent to that of ET-1 did not significantly affect RBF, GFR, or urine output, which were 95, 107, and 84% of control values, respectively. Additional ASP treatment decreased these values to 78, 69, and 52% of control values, respectively. L-NMMA infusion during big ET infusion showed little effect on renal function. Our study demonstrated that intrarenal infusion of ET-1, at a dose of 0.4 pmol/kg/min, caused significant hemodynamic and functional changes in the canine kidney compared with an equivalent molar concentration of big ET.

Saccular aneurysms of the distal anterior cerebral artery

We report a series of 42 consecutive patients with aneurysms of the distal anterior cerebral artery (ACA). Of these, 36 patients had one aneurysm, 5 had two aneurysms, and one had three aneurysms. Thirty patients had a ruptured distal ACA aneurysm; among these patients, the size of the aneurysm was less than 5 mm in diameter in 20, 6 to 10 mm in 7, and larger than 11 mm in 3. Eighteen patients (42.9%) had multiple aneurysms, and distal ACA aneurysms were responsible for a subarachnoid hemorrhage in 10. Thirty-four patients underwent direct surgery, and 30 of these had excellent outcomes 3 months after surgery. The treatment of patients with distal ACA aneurysms is often technically difficult, because of their broad neck configuration and the coexistence of other aneurysms. Nevertheless, the present study emphasizes that distal ACA aneurysms tend to bleed, irrespective of their size, and that excellent outcomes are obtainable by direct surgery.

Mental outcome following encephaloduroarteriosynangiosis in children with moyamoya disease with the onset earlier than 5 years of age

The mental prognosis of children with moyamoya disease, in whom the onset was when they were younger than 5 years of age, has been reported to be very poor. We studied the mental outcome of these patients after encephaloduroarteriosynangiosis (EDAS) in relation to the age at the onset of the disease and the age at operation. For patients in whom the onset of moyamoya disease occurs when they are younger than 2 years of age, the prognosis is very poor with regard to mental abilities even if they have an operation within a year after the onset. Slight hope remains if the operation is within 3 months of the onset. For patients in whom the disease begins when they are 2-5 years of age, EDAS performed before the age of 9 years may result in a good outcome with regard to mental ability, as well as resolution of the paroxysmal symptoms and cerebral revascularization.

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.

Substitution of S-(beta-aminoethyl)-cysteine for active-site lysine of thermostable aspartate aminotransferase

The active site lysyl residue (K239) of the thermostable aspartate aminotransferase [EC 2.6.1.1] was replaced by cysteinyl residue by means of site-directed mutagenesis. The K239C mutant enzyme obtained was catalytically inactive. The reaction of the cysteinyl residue of the K239C mutant enzyme with ethylenimine led to the formation of S-(beta-aminoethylcysteinyl (SAEC) residue. The K239SAEC mutant enzyme obtained showed about 25% of the activity of wild-type enzyme, and absorbed at 375 nm, which suggested the internal Schiff base formation.

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.

A comparison of lisinopril with enalapril by monitoring plasma angiotensin II levels in humans

The present study was designed to examine and compare the acute effects of lisinopril (20 mg) and enalapril (10 mg) after a single oral administration on the inhibition of the renin-angiotensin system (RAS) in eight normal subjects. Serum concentration of lisinopril and enalaprilat, an active metabolite of enalapril, reached the respective maximal levels at 6 and 4 hr after administration of the drugs. At 24 hr, the serum concentration of lisinopril was higher than that of enalapril; thus the rate of disappearance of lisinopril was retarded, in comparison to that of enalapril. The reduction of serum angiotensin I converting enzyme (ACE) activity was consistent with the pattern of increase of concentration of the drugs in the serum. However, with these two drugs, the concentration of plasma ANG II was decreased in a similar manner, and it returned to the pretreatment level within 24 hr. Thus, there was no significant difference in ANG II levels throughout the 24 hr-study between the lisinopril and enalapril treatment. The results indicate that a single administration of 20 mg lisinopril and 10 mg enalapril show similar potency for lowering the circulating ANG II level, although lisinopril exerts a more sustained inhibition of serum ACE activity. The measurement of ANG II provides useful informations for evaluating the efficacy of ACE inhibitors for the inhibition of circulatory RAS.

[Anesthesia for a patient with spinocerebellar degeneration who developed atrioventricular block]

A 54-year-old female with a history of spinocerebellar degeneration (SCD) and myoma uteri had general anesthesia for the abdominal total hysterectomy. Though the operation was uneventfully performed, various atrioventricular blocks occurred. These might be related to the SCD. Hypertonic state of the vagus was considered to be the quite possible cause of the block. Myocardial degeneration associated with the SCD was also an undeniable factor of the block. No arrhythmia occurred and symptoms of the SCD were not aggravative after the anesthesia and the patient was discharged uneventfully.

An electrophoretic polymorphism in salivary amylases (Amy-1) of mastomys (Praomys coucha)

An electrophoretic polymorphism of salivary amylases (Amy-1) in mastomys (Praomys coucha) (MWC, MRJ and MCC strains) was detected. Amylase in MWC or MRJ saliva, which migrated fast toward the anode, was designated as AMY-1A, and that in MCC saliva migrating slowly as AMY-1B. Salivary amylases are controlled by a pair of codominant alleles at a single autosomal locus (Amy-1). No polymorphism was seen in pancreatic amylases (Amy-2). The frequencies of these phenotypes did not differ between the sexes. Some isoamylases were observed and these were different from those in mouse or rat.

Mechanisms of intracellular pH regulation in the hamster inner medullary collecting duct perfused in vitro

To examine the mechanisms of H+ transport in the mid-inner medullary collecting duct of hamsters, we measured the intracellular pH (pHi) in the in vitro perfused tubules by microscopic fluorometry using 2',7'-bis(carboxyethyl)-carboxyfluorescein (BCECF) as a fluorescent probe. In the basal condition, pHi was 6.74 +/- 0.04 (n = 45) in HCO3(-)-free modified Ringer solution. Either elimination of Na+ from the bath or addition of amiloride (1 mM) to the bath produced a reversible fall in pHi. After acid loading with 25 mM NH4Cl, pHi spontaneously recovered with an initial recovery rate of 0.096 +/- 0.012 (n = 23) pH unit/min. In the absence of ambient Na+, after removal of NH+4, the pHi remained low (5.95 +/- 0.10, n = 8) and showed no signs of recovery. Subsequent restoration of Na+ only in the lumen had no effect on pHi. However, when Na+ in the bath was returned to the control level, pHi recovered completely Amiloride (1 mM) in the bath completely inhibited the Na(-)-dependent pHi recovery. Furthermore, elimination of Na+ from the bath, but not from the lumen, decreased pHi from 6.97 +/- 0.07 to 6.44 +/- 0.05 (n = 12) in the HCO3-/Ringer solution or 6.70 +/- 0.03 to 6.02 +/- 0.5 pH unit/min in the presence of CO2/HCO3-, whereas it did not recover in the absence of CO2/HCO3-.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Preparative high-performance liquid chromatography on chemically modified porous glass. Isolation of saponins from ginseng

Preparative high-performance liquid chromatography on octadecylsilyl porous glass (pore size, 550 A) with acetonitrile-water as the mobile phase was applied for the isolation of saponins from Panax ginseng. In a single run, several milligrams of pure ginsenosides were obtained from 10 g of roots of Panax ginseng. The method was simple, rapid and convenient and should be applicable to isolation of other saponins of crude drugs.

Simultaneous determination of ginsenosides and saikosaponins by high-performance liquid chromatography

Octadecyl porous glass was used as the packing for reversed-phase high-performance liquid chromatography. A mixture of ginsenosides and saikosaponins (saponins of ginseng and bupleurum root, respectively) were analysed with detection at 203 nm. A well resolved chromatogram of ginsenoside Rb1, Rc, Rb2 and Rd and saikosaponin a, b2 and c was obtained with acetonitrile-water (25.5:74.5) as the mobile phase. The whole separation was achieved in 20 min with a flow-rate of 1.5 ml/min. Calibration graphs for ginsenoside Rb1, Rc, Rb2 and Rd and saikosaponin a and c were linear up to 5 micrograms. Rapid and accurate simultaneous determinations of the saponins are possible by the described method.

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.

Possible role of renal prostaglandin E2 in natriuresis associated with supraventricular tachycardia

We investigated the possible role of renal prostaglandin (PG) E2 in natriuresis associated with supraventricular tachycardia (SVT). In five female patients with paroxysmal tachycardia, SVT was artificially induced and then stopped 60 min later. Before, during, and after SVT, plasma levels of arginine vasopressin and atrial natriuretic peptide (ANP) and the urinary excretion of sodium and PGE2 were measured. Polyuria was observed during SVT. However, natriuresis did not occur until immediately after the termination of SVT. During SVT, the plasma levels of arginine vasopressin tended to decrease. When SVT was terminated, the vasopressin levels increased significantly (p less than 0.01). Urinary excretion of PGE2 tended to decrease during SVT and then increased significantly (p less than 0.01) after SVT ended. Urinary excretion of sodium was correlated (r = 0.699, p less than 0.001) with the urinary excretion of PGE2. Plasma ANP increased during SVT, but there was no correlation with urinary sodium excretion. These results suggest that renal PGE2, the biosynthesis of which may be stimulated by a increase in plasma vasopressin, is an important factor contributing to the natriuresis observed after the end of SVT.

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.

[A case report of mediastinal malignant lymphoma with long survival following combination chemotherapy using adriamycin, vincristine and cyclophosphamide]

Mediastinal B-cell malignant lymphoma of a 22-year-old female was successfully treated by combination chemotherapy including Adriamycin, Vincristine and Cyclophosphamide. She suffered from dyspnea and axillary tumor in September 1984. Roentgenological examination revealed a large anterior mediastinal tumor. Biopsy of the axillary tumor yielded a diagnosis of metastatic undifferentiated carcinoma from thymus by hematoxylin and eosin. Radiotherapy and chemotherapy including CDDP and ACNU resulted in a symptom-free period of only 2 months. Superior vena cava syndrome and massive pleural effusion recurred. Salvage chemotherapy including Adriamycin, Vincristine and Cyclophosphamide resulted in rapid therapeutic effect. Six courses of chemotherapy were administered, and she is alive and well 4 years after the first salvage chemotherapy. A definitive diagnosis of B-cell lymphoma was made after review of biopsy specimens using immunohistochemical procedures. To select adequate treatment for mediastinal malignant lymphoma, reliable diagnostic procedures including immunohistochemistry are needed. Intensive chemotherapy with appropriate drugs may obtain good response even in advanced cases, such as this.

[Toxicity and carcinogenicity studies of musk xylol in B6C3F1 mouse]

Toxicity and carcinogenicity studies of musk xylol were examined in B6C3F1 mice. The LD50 of the chemical was considered to be more than 4000 mg/kg. In the acute toxicity and 14-day repeated-dose oral toxicity studies, tremor was observed in some animals given high doses of the chemical. In the 17-week repeated-dose oral toxicity study, musk xylol was given at dietary dose levels of 0.0375, 0.6%. During the experimental period, almost all mice given 0.3% or more died. There was no difference in the body-weight gain between the treated groups given 0.15% or less and the control group. Histologically, enlargement and irregularity of hepatocyte were found in both sexes given 0.15% or more. Based on the results, the chemical was given at dietary levels of 0 (control), 0.075 or 0.15% for 80 weeks in the carcinogenicity study. Overall tumor incidences in all treated groups of both sexes were significantly higher than those in the respective controls. Combined malignant and benign liver cell tumors increased clearly in both sexes and a significant positive trend for the occurrence of hepatocellular carcinomas was noted in males. Incidences of lung and Harderian gland tumors and lymphomas in treated groups were also slightly higher than those in controls. In addition, incidences and total numbers of malignant tumors increased significantly in treated groups of both sexes, although no dose-relation was evident. The results demonstrated that musk xylol is carcinogenic in B6C3F1 mice of both sexes when given at dose-levels of 0.075 or 0.15% in the diet for 80 weeks.

Symptoms and their pattern of progression in childhood moyamoya disease

In the series of 81 childhood moyamoya patients, the common pattern of clinical progression seen in 77 patients was revealed to be no more than four. The characteristics of each type of clinical progression were presented for a better understanding of the disease and for an initiation of early treatment of this rather rare and insidiously progressive disease. Type I (21 cases) and type II (15 cases) are cases without infarction, even in those types there are cases with poor IQ. Type III (17 cases) and type IV (24 cases) are cases with infarction and an early operation is mandatory. Types I and II are also good candidates for early operation, for IQ deterioration insidiously progress in these types and there is no way of knowing them from type III before infarctions occur. We now have effective surgical measures to improve the ischemic conditions of this disease.

[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.