Spontaneous neoplastic lesions in aged Sprague-Dawley rats.

Neoplastic lesions were observed in untreated aged Sprague Dawley (SD) rats throughout their lifespan starting at 5 weeks. Their mean survival times were 89 to 105 weeks of age. The total tumor incidences were 70 to 76.7% and 87 to 95.8% in males and females, respectively. The common neoplasmas were pituitary adenoma and adrenal pheochromocytoma in both sexes, testicular Leydig cell tumor in males and mammary gland tumors, thyroidal C-cell adenoma and uterine stromal polyp in females.

[A 13-week oral repeated dose toxicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a novel drug for urinary frequency and incontinence, in rats followed by a 5-week recovery test].

A 13-week oral repeated dose toxicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, was conducted in Sprague-Dawley rats. Male and female rats were given the drug orally for 13 weeks at doses of 0 (control), 6, 30, 150 and 750 mg/kg. After discontinuation of the treatment, a 5-week recovery test was also conducted at doses of 0, 30, 150 and 750 mg/kg. Nine cases of death occurred in the 750 mg/kg group. Main pathological findings in these cases were congestion and edema in lung. Mydriasis, salivation, lacrimation and a decrease in body weight or a suppression of its weight gain were seen in the 30 mg/kg group and over. Piloerection and an increase in water consumption were seen in the 150 and 750 mg/kg groups. In addition, a decrease in spontaneous locomotor activity, abdominal distention, unkempt fur, soft stool, diarrhea and decreases in feces and food consumption were seen in the 750 mg/kg group. Ophthalmologic examination confirmed mydriasis and lacrimation in the 30 mg/kg group and over. Urinalysis showed decreases in Na+ and K+ excretions in the 30 mg/kg group and over, an increase in urinary protein in the 150 and 750 mg/kg groups, and a decrease in urine volume in the 750 mg/kg group. Hematological examination showed decreases in hemoglobin and hematocrit in the 150 and 750 mg/kg groups, and a decrease in lymphocytes in the 750 mg/kg group. Blood chemical examination showed an increase in total protein in the 30 mg/kg group and over, a decrease in triglyceride in the 150 and 750 mg/kg groups, and an increase in BUN in the 750 mg/kg group. Pathological examination disclosed hepatocellular hypertrophy caused by hyperplasia of smooth-ER in the 30 mg/kg group and over, and a decrease in number of glycogen granules in the 150 and 750 mg/kg groups. Stimulated thyroid follicles were seen in the 30 mg/kg group and over. Increases in incidence and severity of chronic progressive nephropathy were observed in the 150 and 750 mg/kg groups. Ultrastructual features of the renal lesions were swelling and foot process loss of the glomerular epithelial cells, absorption droplets in the glomerular epithelial cells, increase of lysosomes in the proximal tubular cells and hyaline casts in the tubular lumen. Adrenocortical hypertrophy was seen in the 150 and 750 mg/kg groups. In the 750 mg/kg group, a decrease of hematopoietic tissue in bone marrow and thymic and testicular tubular atrophy were observed. The recovery test showed that the above-mentioned changes were satisfactorily reversible or the degree and frequency of these changes were lowered. No treatment-related effects were seen in the 6 mg/kg group. These results show that the NOAEL (no observed adverse effect level) of NS-21 is 6 mg/kg for 13-week oral toxicity in rats.

[A 13-week oral repeated dose toxicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a novel drug for urinary frequency and incontinence, in dogs followed by a 5-week recovery test].

A 13-week oral repeated dose toxicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, was conducted in beagle dogs. Male and female dogs were given the drug orally for 13 weeks at doses of 0 (control), 5, 25 and 125 mg/kg. After discontinuation of the treatment, a 5-week recovery test was also conducted. No effects related to the treatment were observed on survival. Mydriasis and a decrease in body weight or a suppression of its weight gain were seen in the 25 and 125 mg/kg groups. Vomiting, salivation and a decrease in food consumption were seen in the 125 mg/kg group. Ophthalmologic examination confirmed the mydriasis in the 125 mg/kg group. Electrocardiographic examination and urinalysis showed no abnormalities attributable to the treatment. Hematological examination showed an increase in number of platelets in the 125 mg/kg group. Blood chemical examination revealed increases in GPT and ALP and a decrease in albumin in the 25 and 125 mg/kg groups, and an increase in triglyceride in the 125 mg/kg group. Pathological examination disclosed hepatocellular hypertrophy in the 125 mg/kg group, hyperplasia of smooth-ER and concentric lamellar bodies derived from the smooth-ER, and bile pigments in the bile capillary, hepatocyte and stellate cells of Kupffer in the 25 and 125 mg/kg groups. Megakaryocytes in mesenteric lymph node were observed in the 25 and 125 mg/kg groups. The recovery test showed that the above-mentioned changes were satisfactorily reversible or the degree and frequency of these changes were lowered. No treatment-related effects were seen in the 5 mg/kg group. These results show that the NOAEL (no observed adverse effect level) of NS-21 is 5 mg/kg for 13-week oral toxicity in dogs.

[A 12-month oral repeated dose toxicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a novel drug for urinary frequency and incontinence, in dogs followed by a 2-month recovery test].

A 12-month oral repeated dose toxicity study of (+/-)-4-diethylamino-1, 1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, was conducted in beagle dogs. Male and female dogs were given the drug orally for 12 months at doses of 0 (control), 3, 17.5 and 100 mg/kg. After discontinuation of the treatment, a 2-month recovery test was also conducted. No effects related to the treatment were observed on survival and water consumption. Mydriasis, vomiting and a decrease in body weight or a suppression of its weight gain were seen in the 17.5 and 100 mg/kg groups. Salivation and a decrease in food consumption were seen in the 100 mg/kg group. Ophthalmologic examination confirmed the mydriasis in the 17.5 and 100 mg/kg groups. Electrocardiographic and hematological examinations and urinalysis showed no abnormalities attributable to the treatment. Blood chemical examination revealed increases in GPT and ALP in the 17.5 and 100 mg/kg groups, increases in GOT and triglyceride and a decrease in total protein in the 100 mg/kg group. Pathological examination disclosed hepatocellular hypertrophy and concentric lamellar bodies derived from the smooth-ER in the 100 mg/kg group, and hyperplasia of smooth-ER, an increase in number of lysosomes and bile pigments in the bile capillary, hepatocyte and stellate cells of Kupffer in the 17.5 and 100 mg/kg groups. The recovery test showed that the above-mentioned changes were satisfactorily reversible or the degree and frequency of these changes were lowered. The serum concentrations of NS-21 and its active metabolite. RCC-36, in the treated groups were increased in a dose-dependent manner. No treatment-related effects were seen in the 3 mg/kg group. These results show that the NOAEL (no observed adverse effect level) of NS-21 is 3 mg/kg for 12-month oral toxicity in dogs.

[The mechanism of increased thyroidal function caused by (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate(NS-21), a novel drug for urinary frequency and incontinence, administration in rats].

A study was conducted to elucidate the mechanism of the increased thyroidal function caused by oral administration of (+/-)-4-diethylamino-1, 1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, in rats. Rats were given 500 mg/kg of NS-21 orally for 13 weeks. Rats were also given 500 mg/kg of the drug and 15 micrograms/animal of thyroxine (T4) in order to assess the influence of T4 treatment. NS-21 caused decreases in both total and free T4 and increases in TSH and thyroxine uridine diphosphate glucuronyltransferase (T4UDP-GT). Morphological examination of thyroid gland revealed stimulated follicles indicating heightened thyroidal function. The treatment of T4 inhibited the stimulating effect of NS-21 on thyroid gland. These results show that the administration of NS-21 caused induction of T4UDP-GT, which resulted in a compensatory stimulation of the thyroidal function by the increased secretion of pituitary TSH in response to increased blood thyroid hormone metabolism.

[A 13-week oral toxicity study of prulifloxacin (NM441) in dogs followed by a 5-week recovery test].

A repeated dose toxicity study of prulifloxacin, a new antibacterial agent, was conducted in beagle dogs. Male and female dogs were given the test material orally for 13 weeks at doses of 0 (control), 20, 100 and 500 mg/kg. After discontinuation of the treatment, a 5-week recovery test was also conducted. Vomiting, salivation and decreased body weight gain or reduced body weight were seen in the 100 and 500 mg/kg groups. In the 500 mg/kg group, tremor, paresis of posterior limb associated with prone or sitting position and decreased food consumption were also observed. There were no treatment-related effects on survival and water consumption. Ophthalmoscopic, electrocardiographic and hematologic examinations, and urinalysis failed to show any abnormalities attributable to the treatment. Blood chemical examination showed increased GPT and decreased beta- and gamma-globulins in the 100 and 500 mg/kg groups, and increased GOT in the 500 mg/kg group. In pathological examination, cavitations and erosions were seen in the humeral and femoral articular cartilages in the 100 and 500 mg/kg groups. The above-mentioned changes were satisfactorily reversible except for erosions in the humeral and femoral articular cartilages in the 100 and 500 mg/kg groups. No toxicological findings were seen in the 20 mg/kg group. The results show that the NOAEL of prulifloxacin is 20 mg/kg for 13-week repeated dose toxicity in dogs.

[Renal toxicity of prulifloxacin (NM441) in rats].

Renal toxicity of prulifloxacin, a new antibacterial agent, was investigated in rats of both sexes. The animals were given prulifloxacin orally for 28 days at a dose of 3000 mg/kg. Tubular nephrosis in which crystalline substances appeared primarily within tubules was observed from the second day of administration, and a large number of brown circular crystals were found in the urinary sediment from the first day of administration. Electron microscopic observation revealed a close resemblance of the ultrastructural characteristics between the intratubular crystalline substance and the urinary brown circular crystal, and the tubules were occasionally occluded by the crystalline substances. Infrared spectral analysis and X-ray microanalysis indicated that the brown circular crystal consisted of NM394, an active metabolite of prulifloxacin. These results suggested that NM394, which was filtered into the primary urine, may be precipitated as crystals on the process of water reabsorption in the tubules. And then most of the crystals would be washed out as crystalluria particles, and some of crystals retained and caused the obstructive uropathy.

[A 13-week oral toxicity study of prulifloxacin (NM441) in rats followed by a 5-week recovery test].

A repeated dose toxicity study of prulifloxacin, a new antibacterial agent, was conducted in Sprague-Dawley rats. Male and female rats were given the test material orally for 13 weeks at doses of 0 (control), 30, 170 and 1000 mg/kg. After discontinuation of the treatment, a 5-week recovery test was also conducted. Salivation, soft feces, reduced body weight gain and increased water consumption were seen in the 1000 mg/kg group. There were no treatment-related effects on survival and food consumption. Ophthalmoscopic and hematologic examinations failed to show any abnormalities attributable to the treatment. Urinalysis revealed increased urine volume and decreased K+ excretion in the 1000 mg/kg group. Blood chemical examination showed increased BUN, decreased triglyceride, K+, Cl- and total protein in the 1000 mg/kg group. Pathological changes caused by the treatment were as follows. Renal tubular nephrosis with crystalline substance was observed in the 170 and 1000 mg/kg groups. Renal weight was increased and crystalline substance was noted in the lumen of the urinary bladder in the 1000 mg/kg group. Cecal distention with increased its organ weight was observed in all dose groups and swelling of its absorptive cells was seen in the 170 and 1000 mg/kg groups. Swelling of jejunal goblet cells was observed in the 1000 mg/kg group. In femoral articular cartilage, focal accumulation of chondrocytes, small cavities and proliferation of fibrous tissue were seen in the 170 and 1000 mg/kg groups. The above-mentioned changes were reversible except for renal tubular nephrosis and cecal distention with its increased organ weight, of which the degree and frequency, however, were lowered. The cecal distention in the 30 mg/kg group was considered to be attributable to the pharmacological effect of the test material. The results show that the NOAEL of prulifloxacin is 30 mg/kg for 13-week repeated dose toxicity in rats.

[13-week oral toxicity study of lactitol (NS-4) in rats followed by 5-week recovery test].

Twenty male and 20 female Slc : SD rats were orally given lactitol, a hepatic encephalopathy drug, for 13 weeks at doses of 0, 0.625, 2.5 or 10 g/kg/day. A 5 week recovery test was conducted after the discontinuation of the drug treatment. Soft stool and decreased food consumption were seen in the 2.5 and 10 g/kg groups. In the 10 g/kg group, there were diarrhea, soiled fur, abdominal distention, salivation, piloerection, decreased body weight gain and increased water consumption. Urinalysis showed decreased urine volume and K+ excretion in the 10 g/kg group. In this dose group, biochemical examination showed decreased ALP, total cholesterol, triglyceride, glucose, Ca, Na+, Cl- and total protein. In the pathological examination, the cecum weight was increased in all dose groups. In the 2.5 and 10 g/kg groups, cecum distention with mucosal hyperplasia was observed. The adrenal weight was increased in the 10 g/kg group and hypertrophy of zona fasciculata of adrenal gland were seen in the 2.5 and 10 g/kg groups. The thymic weight was decreased in the 10 g/kg group. Ophthalmoscopic and hematologic examinations failed to reveal any drug induced changes. The increased cecum weight in the 0.625 g/kg group was regarded as toxicologically insignificant because of the failure of the association with any clinical or morphological findings. The above mentioned changes were satisfactorily reversible except for those in the cecum. Based on the results obtained, the NOAEL of this study was suggested to be 0.625 g/kg/day.

A case of multiloculated, intracranial epidermoid cyst in a beagle dog.

An intracranial epidermoid cyst was identified within the fourth ventricle of a male 10-month-old beagle dog. The cyst, which exhibited a multilocular structure, was lined by a stratified squamous epithelium and filled with desquamated keratin. In the region of the roof of the fourth ventricle, choroid plexus adherent to the cyst wall and secondary compression of the cerebellum were also seen.

Disinfection of water with quaternary ammonium salts insolubilized on a porous glass surface.

Insoluble quaternary ammonium salts bound to porous glass showed antibacterial activity. An agent designated as G(12), which had a dodecyl alkyl chain, was selected for some antibacterial tests on comparison of it with the agent reported previously. The antibacterial activity of G(12) toward Escherichia coli was mainly due to the adsorption of cells and therefore gradually decreased during continuous treatment of a cell suspension. The lost G(12) activity was completely recovered by washing with ethanol, and the activity of refreshed G(12) decreased in the same manner as that of fresh G(12). The lost activity was, however, always recovered only by ethanol treatment. This indicated that G(12) might interact with cells more strongly by means of a hydrophobic force than an electrostatic one. The antimicrobial spectrum showed that G(12) was effective against not only bacteria but also yeasts.

Adsorption of Escherichia coli onto insolubilized lauryl pyridinium iodide and its bacteriostatic action.

Insoluble lauryl pyridinium iodide [C12(50)] was synthesized as an antimicrobial agent. Escherichia coli cells were not killed by C12(50) but only adsorbed onto it. Though cells on C12(50) could not grow in nutrient agar, they possessed the ability to develop once they were liberated from C12(50). The adsorption of cells onto C12(50) was inhibited by iodide anions released from C12(50) itself. The ability of C12(50) to adsorb was decreased by the adsorbed cells, but C12(50) could be reactivated by washing with alkaline solutions. It was, therefore, suggested that this adsorption was mainly due to the electrostatic interaction between cells and C12(50). The adsorption of cells onto C12(50) was confirmed by scanning electron microscopy.

Antimicrobial characteristic of insoluble alkylpyridinium iodide.

Insoluble and soluble alkylpyridinium iodides (C8 to C18) were synthesized. The insoluble agents were quaternized 4-vinylpyridine-divinylbenzene copolymers. The insoluble agent [C12(50)] that contained 50% divinylbenzene and had a C12 alkyl chain was selected as the most suitable insoluble agent. C12(50) showed poor durability of the antibacterial activity, but C12(50), which had lost the activity, was refreshed by washing with ethanol. This washing became ineffective after a few cycles of antibacterial treatment and refreshment. Such C12(50) recovered the activity upon 1.0 N NaOH treatment. The antibacterial activity of C12(50) depended on its surface area. It showed high antimicrobial activity against gram-positive bacteria and also showed activity against gram-negative bacteria and yeasts. But the activities of C12(50) and laurylpyridinium iodide solution were different against some microbes. The antibacterial activities of the agents were investigated against Escherichia coli and Micrococcus luteus under various conditions. The activity of C12(50) was higher at a higher temperature or at a lower cell concentration. The activity of C12(50) decreased on addition of NaCl, glucose, or bovine albumin to the cell suspension or in 0.01 M sodium-potassium phosphate buffer. C12(50) showed less activity when cells were mixed with dead cells or the supernatant of dead cells killed in an autoclave. The mode of action of the laurylpyridinium iodide solution against E. coli and M. luteus was similar to that of C12(50) except for the influence of E. coli cell concentration.