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Biomedical subjects

N Ito

Publications and source records attributed to N Ito.

At least 343 records · Page 19Linked to original sources
PubMed1993

Renal cell adenomas and carcinomas in hemodialysis patients: relationship between hemodialysis period and development of lesions.

Step-sections of 96 whole kidneys from 50 chronic hemodialysis patients were subjected to a histopathological and quantitative investigation with regard to the development of renal neoplastic lesions. The range of hemodialysis duration was from 1 to 222 months. A total of 349 renal cell adenomas were found in 41 cases (82%). They were commonly multiple and present bilaterally. Renal cell carcinomas were evident in four cases (8%), with hemodialysis durations of 54, 57, 112 and 222 months. The incidence of adenomas increased in a hemodialysis duration-dependent manner, indicating a high risk of renal cell tumor development in chronic hemodialysis patients. Furthermore, acquired cystic disease of the kidney (ACDK) was also observed in 12 cases (24.0%), where the mean hemodialysis period was 143.4 +/- 48.0 months. This value was significantly longer than that of non-ACDK cases (P < 0.001). There was, however, no clear relationship between the appearance of ACDK and renal cell tumors. The present results underline the necessity for attention to possible neoplasia of the kidney in patients on long-term hemodialysis.

Adenoma↗
PubMed1993

[An outbreak of Pseudomonas sepsis associated with nosocomial infection in a pediatric ward].

A five-year old girl, diagnosed with fever of unknown origin (FUO), was transferred to our hospital due to a deterioration in her general condition. Pseudomonas cepacia (P. cepacia) was detected in her blood culture and she soon recovered after imipenem cilastatin (IPM/CS) administration. When the former hospital was informed of the results of her blood cultures, we learned that five other cases of FUO had occurred there within the previous two weeks in noncompromised children. Except for one case, Pseudomonas species was detected in their blood cultures. P. cepacia was found in one case, Pseudomonas aeruginosa (P. aeruginosa) was detected in two other cases, and both P. cepacia and P. aeruginosa were demonstrated in the other patient. Although the origin of the bacteria is unknown, it may have spread to the children through a contaminated liquid reservoir or medical devices.

Bacteremia↗
PubMed1993

Denervated skeletal muscle: MR imaging. Work in progress.

PURPOSE: To evaluate the change in signal intensity of skeletal muscles after denervation and to determine the clinical usefulness of magnetic resonance (MR) imaging in diagnosis of denervation. MATERIALS AND METHODS: Denervated skeletal muscles associated with various forms of peripheral neuropathy and spinal radiculopathy were studied with MR imaging in 17 patients. RESULTS: On T1-weighted images, signal intensity of denervated muscles was normal in 14 patients and high in three. On T2-weighted images, all denervated muscles showed high signal intensity on at least one MR image. High signal intensity in the denervated muscles on T2-weighted images was observed 15 or more days after onset of paralysis. In two patients, signal intensity of denervated muscles returned to normal after relief of paralysis. CONCLUSION: MR imaging is a noninvasive and accurate method for use in diagnosis of denervation and may ultimately eliminate the need for electromyography.

Adipose Tissue↗
PubMed1993

Modifying effects of chemicals on the development of liver preneoplastic placental glutathione S-transferase positive foci in analbuminemic and Sprague-Dawley rats.

Nagase analbuminemic rats (NARs) were compared to the Sprague-Dawley (SD) stock in a medium-term assay system for hepatocarcinogenesis regarding their susceptibilities to the influence of chemicals on the development of glutathione S-transferase, placental form, positive (GST-P+) foci. Two weeks after initiation with diethylnitrosamine (DEN), the animals were exposed alternatively to 0.06% 3'-methyl-4-dimethyl-aminoazobenzene (3'-Me-DAB), 50 ppm DEN, 0.25% ethionine, 1% clofibrate, and 1% butylated hydroxyanisole (BHA) for a 6-wk period. Adequate controls included groups only initiated with DEN or treated with each test compound alone. For evaluation of the modifying potential of the chemicals, indices were generated by using the mean values obtained for number and area of GST-P+ foci after each treatment. Comparison between these indices suggests that SD rats were relatively more sensitive than NARs to the modifying effects of complete carcinogens (3'-Me-DAB and DEN). The strains were similarly-susceptible to the promoting influence of ethionine, a nongenotoxic carcinogen. The inhibitory influence of BHA was more intense in NARs, whereas in both strains clofibrate was associated to similarly reduced values for number and area of GST-P+ foci. The degree of susceptibility of each strain to the modifying influence of chemicals on foci development depended on the chemical agent investigated.

Acetylglucosaminidase↗
PubMed1993

Cell proliferation and forestomach carcinogenesis.

To analyze the role of cell proliferation in phenolic compound-induced rat forestomach carcinogenesis, early forestomach histopathological changes as well as oncogene expression and reversibility of early forestomach lesions were examined in F344 male rats. For the analysis of early lesions, five animals each were treated with butylated hydroxyanisole (BHA), caffeic acid, sesamol, or 4-methoxyphenol in the diet, each at a dose of 2%, and killed for histopathological examination after 12 hr, 1, 3, or 7 days. For oncogene analysis, three animals each were treated with BHA for 15, 30 min, 1, 3, 6, or 24 hr and then sacrificed. In the reversibility study, groups of animals were treated with BHA, caffeic acid, sesamol or 4-methoxyphenol for 24 weeks, and basal diet alone was supplied for a further 24-week period. Animals were killed at 24 and 48 weeks and forestomach epithelium was examined histopathologically. DNA synthesis increased within 12 hr to 3 days after commencement of chemical treatment in all cases. Toxicity and cell proliferation became evident subsequent to increase in DNA synthesis in each case. Elevated expression of c-fos and c-myc oncogenes was demonstrated 15 min after beginning treatment with BHA. In the reversibility study, although most of the proliferative lesions induced by these antioxidants regressed after cessation of chemical treatment, some dysplastic lesions were still observed at week 48. The results indicate that these phenolic compounds act primarily as mitogens in rat forestomach epithelium, with regeneration due to toxicity further enhancing cell proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Gap junctional intercellular communication and cell proliferation during rat liver carcinogenesis.

During multistage liver carcinogenesis, there is a sequential decrease in gap junctional intercellular communication (GJIC), associated with reduced expression of a major liver gap-junction protein (connexin 32). There are also several lines of evidence indicating that the induction of cell proliferation plays an important role during liver carcinogenesis. The relationship between GJIC and cell proliferation and their roles in liver carcinogenesis are not yet known. Results from various experiments suggest that there is a close relationship between the inhibition of GJIC and stimulation of liver cell proliferation. However, our results also suggest that different stimuli may affect cell proliferation and GJIC differentially by different mechanisms.

Animals↗
PubMed1993

Hepatitis in an adult with rubella.

Rubella was accompanied by hepatic dysfunction in a 28-year-old male. Serum aminotransferase levels were moderately elevated and LDH markedly increased, especially LDH isoenzyme 5, whereas total bilirubin and ALP remained almost normal. GOT, GPT and LDH levels were completely normalized by the 21st hospital day. Paired antibody titers of viruses which may cause hepatitis, other than rubella, were of no significance. Laparoscopy showed enlarged, red liver. Histologic and electron microscopic findings of the liver were consistent with acute hepatitis. Hepatic damage with rubella is rare, and it is possible that the hepatic dysfunction seen in adult rubella may be mediated by an immunopathologic mechanism.

Acute Disease↗
PubMed1993

The occurrence of monocytoid B-lymphocytes in the spleen in gastric cancer.

Occurrence of monocytoid B-lymphocytes (MBL) in spleens of 34 patients with gastric cancer was examined. Histologic findings of gastric cancer including classification, depth of invasion, and stage of disease were defined based on the General Rules for the Gastric Cancer Study (Japan). MBL were defined morphologically as having abundant pale cytoplasm with distinct cell borders and small nucleus often with reniform shape. Immunohistochemically, these cells were B-cell in nature, i.e., CD15-, CD43-, CD45RA+, CD45Ro-, CD68-, CD74+, CDw75+, Mx-PanB(L26)+, MBI+, EMA-, PG-MI-. Clusters of MBL were found in 14 of 34 (41%) patients: they were found to be directly adjoining to the periarterial sheath or apart from the white pulp. In the cases without MBL, zonation of mantle zone and marginal zone was apparent with distinct secondary follicles in 72% of cases. Meanwhile, in spleens with MBL, the mantle zone showed atrophy in a half of cases, resulting in indistinct zonation of the mantle zone and marginal zone. Secondary follicles were distinct in less than 30% of cases. Correlation of the occurrence of MBL, evaluated by Spearman's correlation coefficient, revealed that the age was the most important factor (R = -0.4852, P = 0.00364): the median age of patients with and without MBL was 75.7 and 61.7 yr, respectively. The MBL were increased in gastric cancer as compared with other cancers (P < 0.03) and with noncancer spleens (P < 0.1). The age of gastric cancer patients with MBL was older than those in other cancers and noncancer patients. Therefore occurrence of MBL in spleen might be a function of aging.

Aged↗
PubMed1993

Effect of phenol block on peripheral nerve: morphometric and histochemical study in rats.

Nerve degeneration and regeneration following phenol block were investigated quantitatively by coordinated morphometry and histochemistry. Retrograde axonal transport of horseradish peroxidase was used to assess functional deficits in peripheral nerves. After one side of the rat sciatic nerve was blocked by 5 or 10% phenol, horseradish peroxidase was injected into the tibial muscular compartments bilaterally at various time intervals. The number and somatic area distribution of labeled motoneurons on the blocked side were compared to the contralateral unoperated side. After phenol block, the motoneuron number that had decreased during the first 2 weeks increased significantly at 4 weeks, and then returned to the level of the control side at 8 weeks at both phenol concentrations. No difference was found in somatic area between the blocked and control side during the process of recovery. It is concluded that phenol should not be used to cause selective and irreversible nerve block.

Animals↗
PubMed1993

[A case of postpartum silent thyroiditis misapprehended as malignant lymphoma of the thyroid].

A case of postpartum silent thyroiditis misapprehended as malignant lymphoma of the thyroid is reported. The patient was a 30-year-old female who had received irradiation therapy to the neck for malignant lymphoma 9 years ago. She was referred to our department owing to a struma accompanying rapid aggravation of chronic thyroiditis after delivery. The mechanism of this case was possible to be explained by immune rebound theory. It was difficult to make differential diagnosis of this case from malignant lymphoma of the thyroid clinically and cytologically when immune rebound phenomena with invasion of lymphocyte and appearance of lymph follicle were the strongest. Immune state of the patients with chronic thyroiditis accompanied by morphological change should be taken into consideration in the process of making diagnosis of malignant lymphoma of the thyroid.

Adult↗
PubMed1993

[Ipsilateral gustatory disturbance by thalamic hemorrhage].

Animal studies have recently demonstrated that the gustatory pathway ascends in the brainstem ipsilaterally without crossing, and terminates in the ipsilateral lower caudal limit of the thalamus, i.e., the nucleus ventralis posteromedialis parvocellularis (VPMpc). However, little is yet known about the corresponding anatomical arrangement in man. Some clinical reports on cases of ipsilateral gustatory disturbance caused by tegmental pontine hemorrhage have suggested that the human gustatory pathway may also ascend ipsilaterally in the brainstem. Our case is a 35-year-old man, who was admitted to the hospital because of double vision. Computed tomography revealed a small high density area in the right paramedian tegmentum of the upper midbrain. On the 7th hospital day, the patient suddenly complained of dysesthesia on the right side of the oral cavity. Neurological examination demonstrated remarkable total hypogeusia on the right side of the tongue. MR imaging revealed upward extension of the hematoma toward the lower caudal portion of right thalamus. This is first report to demonstrate unilateral gustatory disturbance due to lesion in the ipsilateral thalamus. It is also worth of note that unilateral gustatory disturbance caused by thalamic lesion can be accompanied by sensory impairment in the ipsilateral oral cavity.

Adult↗
PubMed1992

Reversibility of catechol-induced rat glandular stomach lesions.

The potential reversibility of glandular stomach lesions induced by the clastogen, catechol, was examined in groups of male F344 rats treated continuously with 0.8% catechol in the diet for 12, 24, 48, 72, or 96 weeks. After a return to basal diet for 84, 72, 48, 24, and 0 weeks, respectively, the animals were killed for histopathological examination. Incidences of submucosal hyperplasia, adenomas and adenocarcinomas, average number of tumors per rat, and the size of tumors in rats treated with catechol for 12, 24, 48, 72, and 96 weeks increased time dependently. After cessation of catechol treatment, although average number of tumors per rat slightly decreased, the size of tumors tended to increase. Labeling indices in both tumorous and nontumorous areas decreased after cessation of catechol treatment. The results thus indicate that whereas some submucosal hyperplasias or adenomas may regress, others have the potential to develop into adenomas or adenocarcinomas. However, tumor growth does depend to a certain extent on continued catechol treatment.

Adenocarcinoma↗
PubMed1992

Lack of modulation effects of praziquantel on DMN-induced lesion development in the Syrian hamster liver.

The effects of repeated praziquantel administration subsequent to dimethylnitrosamine (DMN) treatment of Syrian hamsters were investigated. The antihelminthic drug was given (200 mg/kg body wt. as a suspension in corn oil, by i.g. intubation) 11 times at 2 week intervals starting at week 4 after initial 20 mg/kg DMN i.p. injections at weeks 0 and 2. Sacrifice at week 28 revealed no differences in either hepatocellular or cholangiocellular lesion development between carcinogen-initiated groups with or without antihelminthic treatment. No lesions were observed in the praziquantel alone or untreated groups. The results thus indicate no promotion potential for praziquantel on nitrosamine-induced lesions in the hamster liver.

Animals↗
PubMed1992

Strategy of research for cancer--chemoprevention.

It has been reported that environmental chemicals are important factors in terms of both development and prevention of human cancer. For the latter, detection of early stages is an essential first step followed by clinical trials for surveying populations at risk. Thus a great deal of attention has been focused on these areas. However, investigations of possibilities for active prevention of cancer development itself form another major project. Chemoprevention of carcinogenesis, which means prevention of carcinogenesis by exogenous chemical compounds, has been investigated extensively in a variety of organs in animal models. Usually attention is concentrated on only one organ. However, antioxidants, such as BHA, exert very different effects on different organs, suggesting the necessity of whole body approaches to the question of chemoprevention. Furthermore, the mechanisms of chemoprevention, including the step of carcinogenesis, i.e., initiation, promotion, progression or whole carcinogenesis steps, in which exogenous compounds exert their protective effects, should be considered. A medium-term bioassay system and a multi-organ carcinogenesis system, which can be used for investigation of potential for cancer chemoprevention, have been developed in our laboratory. Dose dependent inhibitory effects were established for both BHA and alpha-tocopherol in the medium-term bioassay system, and inhibition of small intestinal carcinogenesis by catechins in green tea has also been investigated in our multi-organ carcinogenesis protocol. It is extremely important for prevention of human cancer that we find new candidates for chemopreventive agents using animal studies. This paper reviews published reports on chemoprevention, taking into account effective stages, and proposes suitable experimental animal models for future investigations in this increasingly important area.

Animals↗
PubMed1992

Effects of various bile acids and their sodium salts on development of pepsinogen-altered pyloric glands in rats.

Effects of dietary bile acids and their sodium salts on the development of pepsinogen-altered pyloric glands (PAPG) were examined in male WKY/N Crj rats initially given a single dose of 160 mg/kg body weight of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) by gastric intubation. From week 3 the animals were administered basal diet containing 0.5% supplements of cholic acid (CA), deoxycholic acid (DCA), chenodeoxycholic acid (CDCA) or their sodium salts (Na-C, Na-DC and Na-CDC), or 5% ascorbic acid (ASA) or its salt (Na-AS) for 18 weeks. The concentration of DCA and Na-DC was reduced to 0.3% from week 12. At week 20, animals were killed and the numbers of immunohistochemically-demonstrated PAPG were determined. Values were significantly higher with Na-C and Na-CDC than with the corresponding parent acids, and in the Na-C case PAPG development was greater than with MNNG alone. In addition, Na-CDC itself induced the numbers of PAPG significantly. These results suggest that bile salts are possible intrinsic promoters of gastric carcinogenesis. They were without effect, however, on forestomach lesions.

Animals↗
PubMed1992

N-nitrosoheptamethyleneimine-induced pulmonary and esophageal carcinogenesis and effects of concomitant treatment with bleomycin in rats.

The combination effects of bleomycin with N-nitrosoheptamethyleneimine (NHMI) or dihydroxy-di-N-propylnitrosamine (DHPN) on pulmonary carcinogenesis were investigated. Male F344 rats were given NHMI (20 or 40 ppm) or DHPN (200 ppm) in the drinking water and intraperitoneally injected with bleomycin (1 mg/kg) once a week for 18 weeks and then killed at week 24. Many rats treated with NHMI died before the termination of the experiment due to toxicity or development of advanced esophageal carcinomas, considered to be the main cause of death. Detailed histological examination performed on rats killed at week 24 revealed no statistically significant effects of bleomycin on NHMI or DHPN induction of neoplastic lesions in the lung or esophagus, although pulmonary carcinomas were only found in two rats treated with NHMI plus bleomycin. Under the present experimental conditions, NHMI exerted stronger carcinogenic activity in the esophagus than in the lung, and no obvious modifying effects of simultaneously administered bleomycin were evident on NHMI- or DHPN-induced pulmonary carcinogenesis.

Adenoma↗