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Biomedical subjects

K Shimpo

Publications and source records attributed to K Shimpo.

17 recordsLinked to original sources

T cell receptor beta diversity and joining segments in the NOD mouse.

Pancreatic beta-cell autoantigen recognition by the immune system appears to be a critical event in the evolution of insulin dependent diabetes. Immune recognition involves antigen presentation by macrophages and subsequent antigen-peptide-class II MHC recognition by T cell receptors (TCR). Using the NOD mouse as a model for human IDD, we hypothesized that germline variability in the D beta nod and/or J beta nod segments could contribute to beta cell autoimmunity by influencing the specific peptides that are recognized. As an initial approach to our hypothesis, we sought to compare these segments to other strains of mice in search of genetic polymorphisms as reported in NZW mice. The germ line TCR beta nod gene did not display evidence of an expansion or contraction in the number of D beta nod or J beta nod segments at the level of resolution provided by restriction fragment length polymorphism analysis. The absence of such polymorphisms suggests that D beta nod or J beta nod segments are not different from nonautoimmune strains of mice.

Animals

Ascorbic acid and adriamycin toxicity.

Adriamycin (ADR) is effective against a wide range of human neoplasms. However, its clinical use is compromised by serious cardiac toxicity, possibly through induction of peroxidation in cardiac lipids. Ascorbic acid, a potent antioxidant, was examined for effect in reducing ADR toxicity in mice and guinea pigs. Ascorbic acid had no effect on the antitumor activity of ADR in mice inoculated with leukemia L1210 or Ehrlich ascites carcinoma, but it significantly prolonged the life of animals treated with ADR. ADR elevated lipid peroxide levels in mouse heart, and ascorbic acid prevented the elevation. The significant prevention of ADR-induced cardiomyopathy in guinea pigs by ascorbic acid was proved by electron microscopy. Ascorbic acid and the derivatives may delay general toxicity of ADR and also prevent the cardiac toxicity. The results also suggest the clinical efficacy of the combined treatment of ADR and ascorbic acid or the derivatives.

Animals

[Three-month oral subacute toxicity study of mofezolac (N-22) in rats].

A three-month oral subacute toxicity study of mofezolac (N-22), a non-steroidal anti-inflammatory agent, was performed using dose levels of 6, 20, 60 and 200 mg/kg in rats, and recovery was also assessed one month after withdrawal. 1. Toxic signs caused by N-22 administration, observed only in the 200 mg/kg group, were as follows: soiling around the mouth and/or nose, piloerection, anemia, diarrhea, emaciation and decreased spontaneous locomotor activity. Nine males and thirteen females in the 200 mg/kg group excreted bloody diarrhea and died of general exhaustion between weeks four and thirteen of study. 2. In the 200 mg/kg group, decrease in food consumption and suppression of body weight gain were noted in males from about week four and in females from about week six after initiation of administration, and increase in water consumption was noted in males from about week seven. 3. Urinary examination revealed a decline in urinary pH in males of the 20 mg/kg and above groups and elevation of urobilinogen levels in males of the 60 and 200 mg/kg groups. 4. Hematological examination showed decreases in erythrocyte count (RBC), hematocrit value (Ht) and hemoglobin concentration (Hb) and increase in reticulocyte rate in both sexes of the 200 mg/kg group and an increase in neutrophil rate in males of the 200 mg/kg group. 5. Biochemical examination demonstrated a decrease in chloride (Cl-) in males receiving the 20 mg/kg or above doses and a decrease in calcium (Ca++) in males of the 60 and 200 mg/kg groups. Moreover, there were decreases in cholinesterase (ChE) activity, total protein (TP) and albumin (Alb) values, as well as increases in blood urea nitrogen (BUN), uric acid (UA) and potassium (K+) in both sexes of the 200 mg/kg group, along with elevations in GOT and lactate dehydrogenase (LDH) activities in females of the 200 mg/kg group. 6. The absolute and/or relative organ weights for liver, kidneys, spleen and adrenals were increased in the 200 mg/kg group. 7. On pathological examination, perforating ulceration in the jejunum and ileum, turbid ascites, adhesion and inflammatory changes in capsules of the abdominal organs, splenomegaly, mesenteric lymph node hyperplasia and inflammatory changes in the thoracic cavity were observed in dead animals of the 200 mg/kg group. Similar pathological changes were observed in a few survival cases of the 200 mg/kg group. 8. After a one month recovery period, the above-mentioned changes had mostly recovered, indicating that they were reversible.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral

[Three-month subacute oral toxicity study of mofezolac (N-22) in dogs].

Mofezolac (N-22) is a new developed analgesic and anti-inflammatory agent. A subacute oral toxicity test of N-22 was carried out at dose-levels of 0, 2, 6 and 20 mg/kg/day using male and female beagle dogs. Treatment for 3 months was followed by 1 month recovery period except in the case of both sexes receiving 20 mg/kg/day. The results obtained from the present study were as follows. 1. Observation of general conditions revealed vomiting, sporadic bloody feces, anemia, recumbency and hyposthenia in both sexes receiving 20 mg/kg/day. Anemia or erosion of tongue was observed in each female receiving 6 mg/kg/day. 2. Respectively 3 dogs of both sexes receiving 20 mg/kg/day died during dosing period. In these animals, perforating ulcers were observed in the pars pylorica ventriculi or duodenum, and loss of blood, peritonitis and aggravation of general exhaustion were considered as causes of death. 3. Body weight tended to decrease in both sexes receiving 20 mg/kg/day, and food and water consumption levels decreased in males receiving 2 mg/kg/day or above and females receiving 2 mg/kg/day. 4. Urinalysis demonstrated an increasing tendency for specific gravity of urine and a decreasing tendency for urine volume in males receiving 2 mg/kg/day or above. 5. Hematological examination showed decreases in red blood cell count and Hb concentration in males receiving 2 mg/kg/day or above, and in Ht values in males receiving 6 mg/kg/day or above. 6. Serum biochemical examination revealed decreases in total protein and albumin in both sexes receiving 20 mg/kg/day. 7. There were no remarkable changes in hepatic and renal function, ophthalmological findings or electrocardiogram. 8. In the organ weights, significant decrease in thymus weights was observed in the dead animals receiving 20 mg/kg/day. 9. Pathologically, the dead animals receiving 20 mg/kg/day were found to exhibit peritonitis with perforating ulcers in the pars pylorica ventriculi or duodenum. In the surviving animals of this group, scar ulcers in the pars pylorica ventriculi and small intestine were evident on necropsy, and histopathology revealed neutrophils infiltration and thrombosis in blood vessels in the thickened submucosal stomach tissues. Moreover, localized hepatocyte necrosis and intrasinusoidal cellular infiltration in liver, as well as interstitial cellular infiltration, degeneration and dilatation of the renal tubules in the kidney were observed. In females receiving 6 mg/kg/day, the changes in kidney were similar to those in surviving animals receiving 20 mg/kg/day, and male of the group showed atrophy of thymus.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Oral

Immunogenetic analysis of beta-cell autoimmunity in NOD mice. Relationship of insulitis to T-lymphocyte-receptor beta nod and A beta nod genes.

An early molecular event in the evolution of insulin-dependent diabetes in humans and NOD mice appears to involve the interaction of MHC class II molecules, beta-cell autoantigen-derived peptides, and receptor molecules of helper T lymphocytes. To examine the influence of T-lymphocyte-receptor beta-genes on the development of beta-cell autoimmunity, (NOD x NZW)F1 x NOD backcrossed (BC) mice were studied for the development of insulitis, because insulitis is the pathognomonic histological lesion of autoimmune diabetes. Heterozygosity for H-2nod was permissive for the development of pancreatic interstitial inflammation and peri-islet insulitis, whereas homozygosity for H-2nod was highly associated with insulitis. However, (NOD x NZW)F1 x NOD BC mice developed insulitis regardless of homozygosity or heterozygosity for T-lymphocyte receptor beta nod. Therefore, in our study, T-lymphocyte receptor beta nod did not function as an autosomal-recessive beta-cell autoimmunity gene.

Animals

[Chronic oral toxicity study of proglumetacin maleate in beagle dogs].

A chronic oral toxicity test of proglumetacin maleate (PGM), an anti-inflammatory agent, was studied at dose-levels of 0, 0.6, 2.5 and 10.0 mg/kg/day using male and female beagle dogs. They were treated for 12 months, followed by 1 month recovery period. Excretion soft and mucous feces was observed in females of 2.5 mg/kg/day group. In addition, excretion of diarrheal and blood-tinged feces was also found in females of 10.0 mg/kg/day group. One female animal given 10.0 mg/kg/day of PGM was found dead on day 178 of administration. For about a month before death, diarrheal and blood-tinged feces, decreases in body weight and food consumption, and anemia had been noticed. At the autopsy, brown-cloudy ascitic fluid, adhesion of visceral organs, hyperemia or hemorrhage in the mucosa and serosa of the digestive tract, and an ulcer in the duodenum were found. No significant influences of PGM were noted on the changes of body weights, food and water consumptions, excluding the dead animal. A fecal occult blood test showed an increase in no. of animals with blood-positive reaction in 2.5 and 10.0 mg/kg/day groups of both sexes, especially marked in females of 10.0 mg/kg/day group. In urinary tests, no significant changes were found in any of the PGM-treated groups of both sexes; the dead one, however, showed decreases in urine volume and electrolyte excretion on month 6 of administration. No significant hematological changes associated with the administration of PGM were found in any of the animals excluding the dead one, in which anemia and inflammation-related findings were found on month 6 of administration. Serum-biochemical tests showed no significant changes in any of the PGM-treated groups of both sexes. No significant influences of PGM were found on ICG and PSP clearances, ocular fundus and ECG. At the autopsy performed at the end of administration, no significant changes were found in any of the PGM-treated groups of both sexes. Histopathologically, a duodenal ulcer and peritonitis-related findings were observed in the female dead animal of 10.0 mg/kg/day group. No influences of PGM were found in any of the tests performed at the end of the recovery phase. From these results, the non-effective dose of PGM was estimated to be 0.6 mg/kg/day, and the toxic doses of PGM to be more than 10.0 mg/kg/day for males and 10.0 mg/kg/day for females, respectively, in beagle dogs treated orally with PGM for 12 months.

Administration, Oral

[Study on the toxicity of SF-1008C (II): Subacute toxicity study in rats].

The toxicity of an elemental diet (SF-1008C) for hepatic failure and recovery after administration were investigated in Sprague-Dawley rats. The rats were orally administered the drug in doses of 10, 20 and 30 g/kg/day for five weeks, after which, recovery was studied for five weeks. The results were summarized as below: In the 30 g/kg/day group, decreases in food and water consumption were observed, while the body weight gain and the rate of body weight gain were high compared to the treated control group. In addition, urinary pH and serum total protein were lower, and serum glucose and calcium levels were higher than in the treated control group, but these results were not considered to be due to the drug's toxicity. In the 20 and 10 g/kg/day groups, a slight decrease in food consumption was observed, though the rate of body weight gain was higher than in the treated control group. Slight decreases in urinary pH and serum total protein were observed, but were not considered to be due to the toxic effect of the drug. From the above results, it was concluded that the maximal non-effect dose of SF-1008C in oral administration was 30 g/kg/day, which was the maximally applicable dose in rats.

Administration, Oral

[Percutaneous chronic toxicity study of 10% nitroglycerin (NT-1 ointment) in rabbits].

A chronic toxicity test of 10% nitroglycerin (NT-1 ointment) was carried out in male NZW rabbits. NT-1 ointment was applied to the back skin for 26 weeks at daily doses of 15, 60 and 240 mg/kg as nitroglycerin itself, and 5-week withdrawal period was followed. Topical dermal responses to NT-1: Macroscopically, erythema, edema, scales, papules and dermal thickening were observed in response to NT-1 ointment. In the withdrawal period, however, all of them disappeared. Histopathologically, thickening of epidermis and cell infiltration were observed in response to NT-1 ointment. In addition, elongation of rete ridges and Touton giant cells were found only in 60 and 240 mg/kg groups, and hyperkeratosis only in 240 mg/kg group. At the end of withdrawal period, Touton giant cells were still found in 60 and 240 mg/kg groups, although the other dermal reactions disappeared. Systemic responses to NT-1 ointment: A slight increase in the excretion of loose or mucous feces was observed in 240 mg/kg group. The weights of right and left kidneys were increased by the administration of 240 mg/kg NT-1 ointment, and a similar trend was seen also in the weight of heart, although there found no such among-group differences at the end of withdrawal period. White blood cells, especially neutrophils, and gamma-globulin fraction were increased in response to 240 mg/kg NT-1 ointment. In conclusion, a no-toxic effect dose of NT-1 ointment as nitroglycerin itself was considered to be 15 mg/kg/day for the skin and 60 mg/kg/day for the general somatic system.

Administration, Cutaneous

[Teratological test of 10% nitroglycerin (NT-1 ointment) in rabbits].

A teratological test of 10% nitroglycerin (NT-1 ointment) was carried out in New Zealand White rabbits. Pregnant rabbits were treated percutaneously with NT-1 ointment from day 6 to 18 of gestation at dose levels of 15, 60 and 240 mg/kg/day as nitroglycerin itself. All pregnant rabbits were killed on day 29 of gestation, and the influences of NT-1 ointment upon the performances of dams and fetuses were examined. During the treatment period, erythema was observed on the treated dorsal skin in all groups excluding the nontreatment control group. However, it disappeared soon after the cessation of NT-1 ointment administration. Influences of NT-1 ointment administration were not found at any dose levels on the food consumption and body weight changes of pregnant rabbits. In addition, influences of NT-1 ointment on the reproductive performance of dams and the development of fetuses were not observed at any dose levels. Therefore, the non-effect dose of NT-1 ointment on reproductive performance of dams and fetal development in rabbits was estimated to be 240 mg/kg/day and more as nitroglycerin itself.

Abnormalities, Drug-Induced

[Study on toxicity of halopredone acetate. (II). Subacute toxicity study in rats].

Halopredone acetate (THS-201), a synthetic corticosteroid, is expected to be used clinically for intra-articular injection because of its long-lasting activity in the synovial bursa. Subacute toxicity study was carried out on THS-201 by using Jcl: Wistar rats. THS-201 was subcutaneously administered to the rat in doses of 0.1, 0.5, 2.5 and 12.5 mg/kg/day, with the periods for administration and recovery being 3 and 2 months, respectively. Methylprednisolone acetate (MPA) was used for the positive control in dose of 0.5 mg/kg/day. In the group of THS-201 12.5 mg/kg, the below findings were observed: thinning of lumbar hair, swelling of injection site, suppression in body weight gain and decrease of food consumption. The lesions to lymphatic system were indicated by the examinations of peripheral blood, autopsy and histopathology. Slight changes in erythrocytic and biochemical values were seen, and foreign body granuloma was observed in injected subcutis. These findings, exception for lesion of injection site, were almost recovered after the 2 month-recovery period. In the group of THS-201 2.5 mg/kg, some of the changes were noted slightly. In the groups of THS-201 0.5 and 0.1 mg/kg, any toxic changes attributable to THS-201 were not observed. On the other hand, in the group of MPA 0.5 mg/kg, similar findings noted in THS-201 12.5 mg/kg group were observed, but these changes were recovered almost completely at the end of the 2 month-recovery period. It was concluded that the non-toxic dose and the defined toxic dose of THS-201 in this study were 0.5 and 2.5 mg/kg/day, respectively.

Animals

[Study on toxicity of halopredone acetate. (III). Chronic toxicity study in rats].

Chronic toxicity study of halopredone acetate (THS-201), a synthetic corticosteroid, was carried out using Jcl: Wistar rats. THS-201 was subcutaneously administered to the rat in doses of 0.02, 0.1, 0.5 and 2.5 mg/kg/day, with the periods for administration and recovery being 12 and 2 months, respectively. In the group of THS-201 2.5 mg/kg, the below findings were observed: thinning of lumbar hair, suppression in body weight gain, decrease of food consumption in both sexes and decrease of water consumption in male. The lesions to lymphatic system were indicated by the examinations of hemogram, organ weight and histopathology. A few changes in urinary and biochemical values were seen, and foreign body granuloma was observed in the injected subcutis. After 2 month-recovery period, above-mentioned findings almost disappeared. In the group of THS-201 0.5 mg/kg, some of the changes were noted slightly and disappeared after the recovery period. In the groups of THS-201 0.1 and 0.02 mg/kg, any toxic changes attributable to THS-201 were not observed. It was concluded that the non-toxic dose and the defined toxic dose of THS-201 in this study were 0.1 and 0.5 mg/kg/day, respectively.

Animals

[On the acute toxicity of labetalol (AH-5158), a combined alpha-and-beta-adrenoceptor-blocking agent (author's transl)].

Acute toxicity studies in labetalol were performed using mice, rats and rabbits, An oral administration of labetalol produced an increase in salivary secretion due to local irritation. Death followed convulsions by large doses of labetalol. Pathological examinations suggested that the cause of death by labetalol was circulatory disturbances due to the damage of heart muscles and a subsequent respiratory paralysis. Parenteral LD50 showed almost the same values among mice (50 mg/kg iv, 117 mg/kg ip), rats (66 mg/kg iv, 115 mg/kg ip) and rabbits (43 mg/kg iv). However, species difference was seen in oral LD50 values which were enormously large as compared with iv LD50 values.

Administration, Oral

[On the toxicity of CT-1341 evoked by long-term administration. I. Subacute toxicity of the intravenous anesthetic, CT-1341 in rats (author's transl)].

CT-1341, an intravenous anesthetic was given in various daily doses in rats for a period of one month to test the subacute toxicity. The drug was administered intraperitoneally in rats. Rats tolerated to daily administration of CT-1341 at doses of less than 1.8 ml/kg without showing other particular toxic signs than anesthesia. Main pathological findings were swelling of cells in the liver and renal tubules, and perivascular cuffing in lungs. No severe patho-histological changes were observed in any organs. Mortal cases were seen in the group of rats, in which CT-1341 was given in a daily dose of 5.4 ml/kg. A paralysis of respiratory center was suggested to be cause of death, because no severe patho-histological changes were observed in any organs of mortal rats. Survivals of this group showed no particular symptom except anesthesia, but an inhibition of the growth curve was seen in male rats only.

Alfaxalone Alfadolone Mixture

[On the toxicity of CT-1341 evoked by long-term administration. II. Subacute and chronic toxicities of alphaxalone in rats (author's transl)].

Alphaxalone, an anesthetic steroid dissolved in 20% Cremophor solution was administered intraperitoneally to test the subacute toxicity (administration for one month) and chronic toxicity (administration for 3 months). In daily doses less than 8 mg/kg, alphaxalone did not show any particular toxic sign after administered for three months. Rats tolerated to daily administration of 20 mg/kg for three months, without showing severe toxic signs in body weight curve, blood cells and biochemical data obtained in blood and urine. However, some female rats receiving 50 mg/kg/day of alphaxalone, died by paralysis of respiratory center at the second day. Main histo-pathological changes induced by subacute and chronic administrations of the larger doses than 20 mg/kg, were swelling of cells in the liver and kidneys, but severe pathological changes were not seen in any organs.

Alfaxalone Alfadolone Mixture

[On the toxicity of CT-1341 evoked by long-term administration. III. Subacute toxicity of alphadolone acetate and solvent contained in CT-1341 (author's transl)].

Subacute toxicity of solvent adjuvant, alphadolone acetate and solvent, 20 per cent Cremophor solution contained in CT-1341 was studied by using rats of both sexes. Alphadolone acetate and Cremophor solution were intraperitoneally injected every day for a period of one month. Total rats tolerated to daily administration of 60 mg/kg of alphadolone acetate or of 20 ml/kg of 20 per cent Cremophor solution, without showing significant changes in body weight curves and food intake. No change was observed in blood cells and in biochemical data of blood and urine as compared with control. Rats subjected to daily administration of 60 mg/kg of alphadolone acetate presented slight patho-histological changes such as swelling of cells of the liver and kidneys, and also cell infiltration of pericapillary tissues of the lung.

Alfaxalone Alfadolone Mixture