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1.
Analgesic nephropathy is known to have a high incidence in Australia where, following the experience in Scandinavia, reports have been published for some time recording the association between analgesic nephropathy and urothelial malignancies. The morbid anatomical features of analgesic nephropathy are now sufficiently well accepted to allow a retrospective study of unselected nephrectomies for transitional cell carcinoma of the renal pelvis and ureter, in order to assess the incidence of analgesic-type changes in this well defined group of malignancies. The records of a large general histopathology department between 1972–1978 were searched and 24 consecutive transitional cell carcinomas in these sites treated by nephrectomy were selected for study. Of these, 21 were suitable for assessment and on review were shown to comprise 11 cases with papillary changes acceptable as analgesic in type and five which were suggestive of early analgesic change. Of these 16, seven were female, only two were known analgesic abusers and five were recorded as consuming analgesics on a regular basis. These findings suggest that analgesics may play a significant role in the pathogenesis of urothelial malignancy in the general population.  相似文献   

2.
o‐Phenylphenol (OPP) is a widely used fungicide and antibacterial agent that at high doses has been shown to cause bladder cancer in male F344 rats. The mechanisms underlying OPP‐induced bladder carcinogenicity remain unclear but it has been proposed that a non‐enzymatic pH‐dependent autoxidation of phenylhydroquinone (PHQ), a primary metabolite of OPP, may be a key step in OPP‐induced rat bladder carcinogenesis. To investigate this mechanism and to provide insights into the potential human health relevance of OPP‐induced cancer, a series of in vitro and in vivo experiments were conducted. In human lymphoblastoid TK‐6 cells and rat bladder epithelial NBT‐II cells, strong increases in cytotoxicity were seen at a constant concentration of PHQ by increasing the buffer pH as well as by increasing concentrations of PHQ at a constant pH. In in vivo studies, male rats were administered OPP (4,000 and 8,000 ppm) in a diet supplemented with either 1% ammonium chloride or 3% sodium bicarbonate to produce acidic and alkaline urinary pH, respectively. Significant increases in cell proliferation as detected by 5‐bromo‐2′‐deoxyuridine incorporation and micronucleus formation were seen in the bladder cells of OPP‐treated rats with neutral or alkaline urinary pH but not in animals with the acidified urine. The results from these in vitro and in vivo studies provide support for the autoxidation hypothesis of bioactivation, and provide additional evidence that urinary pH can significantly influence the genotoxicity and carcinogenicity of this important agent. Environ. Mol. Mutagen. 57:210–219, 2016. © 2016 Wiley Periodicals, Inc.  相似文献   

3.
Pathomorphology of the organ of Corti was studied on models of acute and chronic sensorineural damage to the acoustic analyzer. Peculiarities of hair cell degeneration, necrosis, and apoptosis in the organ were studied by light and scanning electron microscopy. The type of pathomorphological substrate in abnormalities of the organ of Corti depends on the intensity of the destructive exposure, but not on the nature of otopathological factors. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 141, No. 3, pp. 356–360, March, 2006  相似文献   

4.
Previous biochemical studies on pooled hepatocytes have provided a wealth of information concerning age-related changes in DNA damage and DNA vulnerability (susceptibility) to oxygen radicals and related oxidants, but these studies focused on the whole liver and not on individual hepatocytes. The present study was designed to clarify the DNA damage and DNA vulnerability to hydrogen peroxide in individual hepatocytes using single cell gel electrophoresis (comet assay), a method that measures DNA single-stranded breaks/alkali-labile sites in individual cells. Hepatocytes were prepared from the liver of young (6–11 months) and old (26–29 months) male Fischer 344 rats. DNA damage was induced by exposure to hydrogen peroxide (3 × 10−5, 3 × 10−4 and 3 × 10−3%). Observation of each comet image (migration length of DNA (MLD)) was performed in a non-exposure status (basal level) and after exposure. The mean value of MLD was significantly increased (approximately 1.5-fold) in the old rats at the basal level (P = 0.009). Moreover, the proportion of highly DNA-damaged hepatocytes (MLD > 80 μm) increased significantly (approximately 2.5-fold) in advanced age (P = 0.02). The mean value of MLD after exposure to hydrogen peroxide was increased with its concentration, but no significant difference was observed in DNA vulnerability to hydrogen peroxide between young and old rats. However, the proportion of hepatocytes showing a markedly high DNA vulnerability (MLD > 140 μm) to hydrogen peroxide was significantly higher in the old rats than in the young rats. It is suggested that the age-related increase in DNA vulnerability to oxygen radicals and/or related oxidants is some subpopulations causes the increase in DNA damage in advanced age in the liver as a whole.  相似文献   

5.
One i.p. injection of a sterile suspension of streptococcal cell walls (SCW) induces chronic erosive polyarthritis in susceptible Lewis rats, but not in resistant F344 or nude Lewis rats. Because continuous exacerbations may be one possible mechanism underlying chronic disease, we studied the mechanism of these flare-up reactions in Lewis and F344 rats. Injection of SCW into the right knee joint of rats induced a transient monoarthritis in both strains. Reactivation of the subsided arthritis by i.v. administration of the same antigen could be evoked only in the Lewis rat. Even repeated i.v. challenges with SCW failed to induce a flare-up reaction in the F344 rat, while the Lewis rat went through an exacerbation after every challenge. Removal of T lymphocytes by monoclonal antibodies before induction of an exacerbation rendered Lewis rats refractory to flare-up reactions, thus indicating the T cell-dependence of this reaction. Furthermore, when cell walls from heterologous bacteria were tested for their capacity to induce exacerbations of SCW-induced monoarthritis and to induce proliferation of SCW-specific T lymphocytes in vitro, a strong correlation between both features was found, again pointing to a role for SCW-specific T cells in exacerbations. Together, these data support our hypothesis that chronic arthritis is the result from repeated reactivations of a waning arthritis which are dependent on antigen-specific T lymphocytes.  相似文献   

6.
There are 2 types of bronchiolo-alveolar hyperplasia found in rat lungs. One is ‘inflammatory hyperplasia’ with a potential to recover in future with removal of the stimulating insult and the other is ‘latent tumorigenic hyperplasia’ as an independent preneoplastic lesion for adenocarcinoma. In the present experiment, we focused on rat lung bronchiolo-alveolar hyperplasia induced by 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK), which decreases with time after induction and reverts to normal, or by N-bis(2-hydroxypropyl)nitrosamine (DHPN), with tumorigenic potential to progress to adenoma and adenocarcinoma. Though NNK is a typical carcinogen inducing lung adenocarcinoma in female A/J mice, the tumorigenic potential by NNK in rats is weak. Differences between hyperplasias induced by DHPN and by NNK were here examined immunohistochemically.Formalin fixed paraffin embedded lung samples with hyperplastic and inflammatory lesions were obtained from rats exposed to DHPN or NNK and from lung inflammation models induced with fine particles like CuO, NiO and quartz. The 19 markers were examined immunohistochemically.Napsin A, in the inflammatory lesions and hyperplasia induced by NNK, was positive for macrophages and secretions in the alveoli spaces but less so in the walls of the alveoli. In the proliferative lesions including hyperplasia induced by DHPN, strong positive staining for napsin A was observed in the walls of the alveoli. Thus high expression was suggested to be possibly useful for detecting tumorigenic potential of rat lung hyperplasia.  相似文献   

7.
目的 评价胶原蛋白(Collagen)的细胞相容性;研究胶原与大鼠胎脑神经细胞(FBN)复合体(C—FBN)脑内移植对脑损伤的修复作用。方法 将大鼠FBN与Collagen联合体外培养,进行光镜、电镜观察,并将体外联合培养4天的C-FBN(移植前48h培养液中加入Brdu)移植到大脑皮质损伤模型的大鼠脑损伤部位,术后3d、6d、10d、15d及30d观察脑组织对移植物的反应、移植细胞生长状态及载体在体内的降解情况等。结果 Collagen对FBN生长无不良影响;脑组织对移植物无明显的免疫排斥反应;Collagen与周围脑组织整合好,有血管长入移植物中;载体内有大量存活神经细胞,术后各时段都检出Brdu阳性细胞;Collagen吸收、降解快,可诱导组织再生。结论 Collagen具有良好的细胞相容性和组织相容性,是神经组织工程的一种较为理想的生物载体材料;移植的FBN在脑内可以长时间存活。  相似文献   

8.
In the course of ischemia and reperfusion a disruption of release and uptake of excitatory neurotransmitters occurs. This excitotoxicity triggers delayed cell death, a process closely related to mitochondrial physiology and one that shows both apoptotic and necrotic features. The aim of the present study was to use electron microscopy to characterize the cell death of pyramidal cells from the CA1 field of the hippocampus after 10 min of transient global ischemia followed by short reperfusion periods. For this study 25 adult male Wistar rats were used, divided into six groups: 10 min of ischemia, 3, 6, 12 and 24 h of reperfusion and an untouched group. Transient forebrain ischemia was produced using the 4-vessel occlusion method. The pyramidal cells of the CA1 field from rat hippocampus submitted to ischemia exhibited intracellular alterations consistent with a process of degeneration, with varied intensities according to the reperfusion period and bearing both apoptotic and necrotic features. Gradual neuronal and glial modifications allowed for the classification of the degenerative process into three stages: initial, intermediate and final were found. With 3 and 6 h of reperfusion, slight and moderate morphological alterations were seen, such as organelle and cytoplasm edema. Within 12 h of reperfusion, there was an apparent recovery and more 'intact' cells could be identified, while 24 h after the event neuronal damage was more severe and cells with disrupted membranes and cell debris were identified. Necrotic-like neurons were found together with some apoptotic bodies with 24 h of reperfusion. Present results support the view that cell death in the CA1 field of rat hippocampus submitted to 10 min of global transient ischemia and early reperfusion times includes both apoptotic and necrotic features, a process referred to as parapoptosis.  相似文献   

9.
Sodium dichromate dihydrate (SDD), an inorganic compound containing hexavalent chromium (Cr(VI)), is a common environmental contaminant of groundwater sources due to widespread industrial use. There are indications in the literature that Cr(VI) may induce immunotoxic effects following dermal exposure, including acting as both an irritant and a sensitizer; however, the potential immunomodulatory effects of Cr(VI) following oral exposure are relatively unknown. Following the detection of Cr(VI) in drinking water sources, the National Toxicology Program (NTP) conducted extensive evaluations of the toxicity and carcinogenicity of SDD following drinking water exposure, including studies to assess the potential for Cr(VI) to modulate immune function. For the immunotoxicity assessments, female Fischer 344/N (F344/N) and Sprague Dawley (SD) rats and female B6C3F1 mice were exposed to SDD in drinking water for 28 consecutive days and evaluated for alterations in cellular and humoral immune function as well as innate immunity. Rats were exposed to concentrations of 0, 14.3, 57.3, 172, or 516?ppm SDD while mice were exposed to concentrations of 0, 15.6, 31.3, 62.5, 125, or 250?ppm SDD. Final mean body weight and body weight gain were decreased relative to controls in 250?ppm B6C3F1 mice and 516?ppm SD rats. Water consumption was significantly decreased in F344/N and SD rats exposed to 172 and 516?ppm SDD; this was attributed to poor palatability of the SDD drinking water solutions. Several red blood cell-specific parameters were significantly (5–7%) decreased in 250?ppm mice; however, these parameters were unaffected in rats. Sporadic increases in the spleen IgM antibody response to sheep red blood cells (SRBC) were observed, however, these increases were not dose-dependent and were not reproducible. No significant effects were observed in the other immunological parameters evaluated. Overall, exposure to Cr(VI) in drinking water had limited effects on the immune system in both rats and mice.  相似文献   

10.
11.
Recent studies demonstrated that administration of a p55-tumor necrosis factor (TNF) receptor IgG-fusion protein (TNFR-IgG) prevented the clinical onset of experimental autoimmune encephalomyelitis but did not alter the number or tissue distribution of autoantigen-specific CD4+ effector T cells which trafficked into the central nervous system. To determine whether specific target tissues of autoimmune damage remain intact after TNFR-IgG treatment despite the presence of inflammatory cells within the tissues, we examined rats with experimental autoimmune uveoretinitis (EAU), as in this model, the main target of autoreactive CD4+ T cells, the retinal rod outer segments (ROS), can be examined readily by light microscopy. As judged by direct ophthalmoscopy, the onset of inflammation in the anterior chamber of the eye in EAU following administration of TNFR-IgG was delayed by 6 days compared to untreated controls, but the magnitude of the response was only slightly less than controls. Histological examination of the retinae and direct assessment of retinal inflammation revealed a disproportionate sparing of ROS in the TNFR-IgG-treated animals despite a level of retinal inflammation not substantially less than controls in which ROS damage was marked. Analysis of retinal leukocytes by immunofluo-rescence microscopy and flow cytometry indicated that approximately equal numbers of CD4+ αβTCR+ lymphocytes were present in treated and control retinae, more than 30% of CD4+ cells in both experimental groups expressed the CD25 or MRC OX40 activation markers and most cells, which would include the CD4+ T lymphocytes, were activated as evidenced by MHC class II expression. Fewer activated macrophages and granulocytes were present in the treated retinae, possibly reflecting the lower level of tissue damage and subsequent accumulation of these inflammatory cells. The results demonstrate directly that a tissue specifically targeted for autoimmune destruction can be protected despite the influx of fully activated CD4+ T cells.  相似文献   

12.
13.
Metabolites ofTrichinella spiralis produced genotoxic and cytotoxic effects on somatic and generative cells of the host organism. They increased the number of single-chain breaks, alkaline-labile sites in nuclear DNA, and count of apoptotic cells in the bone marrow and testes of infected mice. These effects depended on the stage of parasite development in the host organism and became more pronounced with increasing invasion intensity. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 138, No. 9, pp. 320–323, September, 2004  相似文献   

14.
Metabolites of Trichinella spiralis produced genotoxic and cytotoxic effects on somatic and generative cells of the host organism. They increased the number of single-chain breaks, alkaline-labile sites in nuclear DNA, and count of apoptotic cells in the bone marrow and testes of infected mice. These effects depended on the stage of parasite development in the host organism and became more pronounced with increasing invasion intensity.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 9, pp. 320–323, September, 2004  相似文献   

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17.
Experimental autoimmune encephalomyelitis (EAE) is an animal model of multiple sclerosis, a chronic inflammatory and demyelinating disease of the CNS. Albino Oxford (AO) rats are resistant to the induction of EAE, while the disease can be readily induced in Dark Agouti (DA) rats. Here we investigated a potential contribution of the CNS milieu in the limitation of the encephalitogenic autoimmune response. EAE was induced by immunization of the respective rat strains with spinal cord homogenate emulsified in complete Freund's adjuvant. AO rats did not exhibit clinical signs after immunization while DA rats developed severe neurologic deficits. Infiltration of immune cells into spinal cords (SC) was evident in both strains 12-14 days after the immunization. EAE lesions of AO rats contained substantially lower numbers of CD4+ T cells and CD11b+ cells compared to those in DA rats. This went together with lower levels of interferon (IFN)-γ and interleukin (IL)-17 in the cells isolated from SC. We found a dramatic increase of CXCL12 expression in SC tissue and microvessels of AO rats, whereas DA rats markedly decreased the expression of this chemokine within their CNS. Administration of the CXCL12 antagonist AMD3100 to a substrain of AO rats that developed a weak EAE led to earlier onset and exacerbation of the disease. These results suggest a role of CXCL12 in down-regulating autoimmune processes in AO rats during EAE. Therapeutic modulation of CXCL12 could be a promising strategy for the treatment of CNS autoimmunity.  相似文献   

18.
背景:间充质干细胞具有免疫调节特性,脐带间充质干细胞因其特有的优势,将在急性肺损伤和急性呼吸窘迫综合征的临床应用中有着光明的前景。 目的:探讨脐带间充质干细胞移植对内毒素性大鼠急性肺损伤模型的保护作用。 方法:将48只健康雄性SD大鼠随机均分为正常对照组、急性肺损伤组和脐带间充质干细胞移植组。后两组采用经气管内滴注内毒素建立急性肺损伤模型。成功造模1 h后,脐带间充质干细胞移植组,经气管内滴注脐带间充质干细胞混悬液,正常对照组和急性肺损伤组同法予以等量生理盐水。分别在干预后24,72 h,观察肺组织病理改变,检测病理组织评分、肺组织干湿质量比、髓过氧化物酶活性及血浆白细胞介素6、白细胞介素10及肿瘤坏死因子α水平。 结果与结论:脐带间充质干细胞移植可以减轻内毒素诱导的急性肺损伤模型的损伤程度;脐带间充质干细胞移植组在各时间点与急性肺损伤组比较,病理损伤评分、肺干湿质量比、肺组织髓过氧化物酶活性、血浆白细胞介素6和肿瘤坏死因子α水平均明显降低,血浆白细胞介素10水平明显升高。说明脐带间充质干细胞对内毒素性急性肺损伤模型有保护作用;其保护机制可能为脐带间充质干细胞移植维持肺内炎性递质和抗炎递质平衡。  相似文献   

19.
Combination antiretroviral therapy (cART) has shown to cause inflammation, cellular injury and oxidative stress, whereas melatonin has been successful in reducing these effects. The aim of the study was to determine potential morphometric changes caused by cART in combination with melatonin supplementation in human immunodeficiency virus (HIV)-free rats.Tissue samples (N?=?40) of the pancreas, liver and kidney from a control (C/ART-/M-), cART group (C/ART?+?), melatonin (C/M?+?) and experimental group (ART+/M?+?) were collected and stained with haematoxylin and eosin (H&E) and evaluated for histopathology. The pancreata were labelled with anti-insulin and anti-glucagon to determine α- and β-cell regions. Kidneys were stained with periodic acid Schiff (PAS) to measure the area, perimeter, diameter and radius of renal corpuscles, glomeruli and proximal convoluted tubules (PCTs). Blood tests were conducted to determine hepatotoxicity.No significant changes in histopathology were seen. Melatonin stimulated pancreatic islet abundance, as the number of islets per mm2 was significantly higher in the C/M+ than in the C/ART-/M- and ART+/M+. Parameters of the renal corpuscle, glomeruli, renal space and PCTs were significantly lower in the C/ART+ compared to the other groups, thus cART may have caused tubular dysfunction or cellular damage. A significant increase in serum haemoglobin was observed in the C/ART+ compared to the C/ART-, which showed cART increases serum haemoglobin in the absence of immune deficiency. Serum lipids were significantly decreased in the C/M+ compared to the C/ART-, possibly due to the effect of melatonin on the decrease of lipolysis, decreasing effect on cholesterol absorption and stimulation of lipoprotein lipase (LPL) activity.In conclusion, we have demonstrated that melatonin stimulated α-cell production, increased the number of pancreatic islets and caused a decrease in total lipids, whereas cART increased serum haemoglobin and decreased various parameters of the nephron in an HIV-free rat model, suggestive of tubular dysfunction.  相似文献   

20.
Chemotactic cytokines (chemokines) have been traditionally defined as small (10-14kDa) secreted leukocyte chemoattractants. However, chemokines and their cognate receptors are constitutively expressed in the central nervous system (CNS) where immune activities are under stringent control. Why and how the CNS uses the chemokine system to carry out its complex physiological functions has intrigued neurobiologists. Here, we focus on chemokine CXCL12 and its receptor CXCR4 that have been widely characterized in peripheral tissues and delineate their main functions in the CNS. Extensive evidence supports CXCL12 as a key regulator for early development of the CNS. CXCR4 signaling is required for the migration of neuronal precursors, axon guidance/pathfinding and maintenance of neural progenitor cells (NPCs). In the mature CNS, CXCL12 modulates neurotransmission, neurotoxicity and neuroglial interactions. Thus, chemokines represent an inherent system that helps establish and maintain CNS homeostasis. In addition, growing evidence implicates altered expression of CXCL12 and CXCR4 in the pathogenesis of CNS disorders such as HIV-associated encephalopathy, brain tumor, stroke and multiple sclerosis (MS), making them the plausible targets for future pharmacological intervention.  相似文献   

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