Early effects of ethylene glycol on the ultrastructure of the renal cortex in dogs

A sublethal dose of ethylene glycol was administered orally to 3 groups of dogs; dogs of a control group were given distilled water instead. Renal cortical biopsy samples were obtained from dogs of experimental and control groups at various times after treatment. Tissue was examined by use of light microscopy and transmission electron microscopy. In dogs of the control group, the light and electron microscopic appearances of tissue were within normal limits at all sample collection hours. In dogs of the experimental groups, renal corpuscular structure remained within normal limits by use of light and electron microscopy throughout the study, though morphologic change was seen in other structures of the cortex. Light microscopic lesions first appeared at 12 hours, and were similar to those reported in the literature. Ultrastructural lesions were first observed in the 5-hour samples, and similar to the light microscopic lesions, were most common in the proximal convoluted tubules (PCT). Initial PCT cellular changes included vacuolization of cells and distention of the parabasal extracellular spaces; PCT cellular lesions seen in later-hour samples included formation of apical buds and cellular rupture. Internalization or sloughing of the PCT brush border was not observed. Distal convoluted tubules (DCT) were frequently dilated and/or packed with cellular debris. A few DCT cells had degenerative or necrotic changes. In PCT and DCT, abnormal cells were frequently flanked by normal or nearly normal cells. During later hours, a few cells with types of changes first observed in early hours continued to be observed, implying ongoing response of cells to the toxin.     

Testicular alterations in cryptorchid/orchiopexic rats chronically exposed to acrylamide or di-butyl-phthalate

Exposure of Sprague-Dawley (SD) rats to acrylamide (AA) or di-butyl-phthalate (DBP) from the 12th gestational day to the 16th postnatal week (PNW) has been shown to reduce the effectiveness of orchiopexy in recovering the testicular alterations associated with experimental cryptorchidism established at weaning. Herein, we provide information about the long-term effects of AA or DBP on the testes of cryptorchid/orchiopexic rats. Male offspring exposed in utero to 10 mg/kg/day AA or 500 mg/kg/day DBP underwent bilateral surgical cryptorchidism at the 3rd PNW and orchiopexy at the 6th week, with continuous exposure to the chemicals through diet until the 58th week. Regardless of the test chemical, there were severe qualitative/quantitative alterations in the seminiferous tubules and increased numbers of Leydig cells. There was an increase and decrease in the number of tubules with c-Kit- and placental alkaline phosphatase-labeled germ cells, respectively, as compared to those in the control group, suggesting an imbalance between apoptosis and cell proliferation processes. The histological scores of the testicular lesions at the end of this one-year study were higher than those in the previous 16-week study, indicating that exposure of rats to the toxicants AA or DBP enhanced the testicular alterations induced by the chemicals beginning at the intra-uterine life, and impaired the effectiveness of orchiopexy in restoring the testes to normal morphology. Although the present experimental protocol does not completely replicate the natural human undescended testes, our findings may contribute to understanding the alterations occurring in cryptorchid/orchiopexic testes potentially exposed to exogenous chemicals for extended periods.     

Acute airsacculitis in turkeys inoculated with cell-free culture filtrate of Pasteurella multocida

Twenty-six female and 26 male turkeys, inoculated into the caudal thoracic air sacs with cell-free culture filtrate of Pasteurella multocida strain R44/6, were examined from 0 to 6 hours post-inoculation and compared with 26 female and 26 male sham-inoculated control turkeys given brain-heart-infusion broth. The air sac reacted rapidly with exudation of heterophils. Microscopically, low numbers of heterophils were present within air sac blood vessels and also perivascularly by 0.5 hour after inoculation. These became more numerous by 1.5 and 3 hours post-inoculation. By 6 hours post-inoculation, there was severe swelling of air sac epithelial and mesothelial cells and thickening of the air sac by proteinaceous fluid and heterophils. Ultrastructurally, mesothelial and air sac epithelial cells were vacuolated, and interdigitating processes of epithelial cells were separated. Microscopically, in control turkeys, rare heterophils were present perivascularly at 1.5, 3, and 6 hours after inoculation. Ultrastructurally, all features were normal. In turkeys given cell-free culture filtrate, total cell counts in air sac lavage fluids increased markedly by 3 hours post-inoculation in which heterophils predominated (greater than 97%). There were only slight increases in cell counts of air sac lavages from control turkeys. The circulating blood heterophil cell count dropped transiently at 1.5 hours post-inoculation, followed by a return to normal 3 hours after inoculation, and by heterophilia by 6 hours post-inoculation in turkeys given either cell-free culture filtrate or brain-heart-infusion broth. These results indicate cell-free culture filtrate of P. multocida induces hematologic, cytologic, and morphologic changes indistinguishable from those induced by cultures of P. multocida.     

Ultrastructural alterations in furazolidone-induced cystic testicular degeneration in ducklings

Cystic testicular degeneration was induced in groups of ducklings by feeding furazolidone at 250, 400, 550, or 750 mg per kilogram of feed (ppm) for 4 weeks. In normal ducklings, tall, columnar Sertoli cells predominated in the seminiferous epithelium. In treated ducklings, the mildest ultrastructural alteration was cytoplasmic vacuolation of Sertoli cells. In birds with more severely affected tubules, cytoplasmic vacuolation was more severe and the cells were cuboidal or rounded. The rounded cells desquamated into the tubular lumens, eventually undergoing cytolysis. In birds with the most severely affected tubules, only extensively flattened epithelial cells lined the extremely dilated seminiferous tubules. The interstitium was edematous and compacted between the expanded tubules. Many of the testicular ultrastructural alterations in furazolidone-intoxicated ducklings were similar to those described in the testicles of sodium-intoxicated cockerels.     

Ultrastructural postmortem changes in chicken kidneys at 27 C

Ultrastructural postmortem changes of glomeruli, proximal tubules (PT), distal tubules (DT), and cortical collecting ducts (CD) were studied in adult chickens held at 27 C for 0, 1, 5, 10, 30, 60, or 360 minutes. There were marked ultrastructural alterations in tissues considered normal by light microscopy. The earliest changes, evident in immediately fixed samples, consisted of apical cell swelling of PT and DT epithelium and formation of smaller projections from glomerular capillary endothelium. Swelling increased with time, and gaps in cell membranes of tubular cytoplasmic blebs were evident by 10 minutes postmortem. The urinary space also contained cellular debris in immediately fixed samples and was filled by swollen epithelial cells by 10 minutes postmortem. Organelle changes were pronounced by 5 minutes in PT epithelium and by 10 minutes in DT epithelium. These initial changes consisted of dilation of mitochondrial and endoplasmic reticulum. Flocculent mitochondrial matrix densities were present by 5 minutes in PT epithelium and enlarged and appeared in other tubular segments as the time postmortem increased. Nuclear chromatin margination occurred first in 10-minute samples of PT and DT, and it was present by 30 minutes in glomerular epithelial cells. Chromatin clumping was present in PT and DT epithelium at 30 minutes and was followed by pyknosis and karyorrhexis at 360 minutes. These latter nuclear changes were not found in glomerular cells during the study. Nuclei of CD showed little change during the periods studied. The glomerular basement membrane appeared as a single hyaline membrane by 30 minutes postmortem, but this membrane and podocyte foot processes showed little further change by 360 minutes postmortem.     

Influence of environment on adrenal cortical response to ACTH stimulation in clinically normal dogs.

Effect of testing environment on adrenal cortical responses to an injection of ACTH in clinically normal dogs was examined in three locations, presumably of increasing order of stress elicitation: in a home; veterinary hospital (VH), 4 hours in a cage; and VH, overnight in a cage. Basal cortisol (hydrocortisone) values for plasma were significantly lower (P less than 0.001) for the home group (1.8 microgram/dl) when compared with values for the VH, 4-hour cage (3.8 microgram/dl) or the VH, overnight cage (3.9 microgram/dl) groups. However, significant differences (P greater than 0.05) were not observed 2 hours after ACTH admininstration for the home group (13.7 microgram/dl); VH, 4-hour cage group (14.8 microgram/dl); or VH, overnight cage group (16.0 microgram/dl). Responses of individual dogs were consistent (P less than 0.005). The testing environment did not markedly affect results of adrenal cortical function tests for dogs when ACTH stimulation was utilized. The response of dogs to ACTH, as monitored by immunologic assay techniques (competitive protein-binding assay or radioimmunoassay), was consistent and was useful as a diagnostic aid for adrenal malfunction.     

米尔贝肟大鼠急性中毒的病理学研究

以SD大鼠为研究对象,采用一次性灌胃给药法进行米尔贝肟的急性毒性试验,研究了试验大鼠对米尔贝肟的毒性反应和病理变化.结果显示,米尔贝肟对SD大鼠具有雄雌差异性,半数致死量(LD50)分别为2002、1131 mg/kg·BW.大鼠急性中毒4h后,出现明显的临床症状,主要表现为共济失调、立毛、精神委靡、呼吸困难、食欲减退,且呈明显的量效关系.组织病理学变化主要为肝脏中央静脉淤血,肝索排列紊乱,肝细胞颗粒变性;肺淤血;肾小管上皮细胞和消化道黏膜上皮颗粒变性、坏死;脾脏淤血;大脑皮层血管炎症细胞浸润,边缘空泡化.根据WHO外源性急性毒性分级标准,米尔贝肟属低毒化学物.米尔贝肟急性中毒后会广泛损害大鼠肝、肺、肾和肠等多种组织器官,甚至引起这些组织器官的变性坏死,并可对神经组织造成一定的损伤.     

CHRONIC RENAL FAILURE IN A YOUNG PONY

SUMMARY A 19-month-old pony gelding was presented with chronic renal failure, after deteriorating progressively during the preceding 3 months. There was pronounced azotaemia, hyponatraemia and hypochloraemia, but plasma calcium and phosphorus levels were normal. At autopsy both kidneys were small and nodular and were characterised by collapsed segments of cortex and medulla interspersed with areas of pale tissue. The latter showed glomerular immaturity associated with a range of degenerative processes involving the glomeruli and tubules. The condition bore many similarities to that of renal cortical dysplasia in other species.     

Increased levels of DNA synthesis in hyperplastic renal tubules of aging nephropathy in female F344/NCr rats

Histoautoradiography was done to evaluate cell turnover by measuring levels of DNA synthesis in the different anatomic areas of the kidney in aging (76 to 103 weeks of age) female F344/NCr rats after injection of tritiated thymidine (3H-thymidine). All areas showed increased 3H-thymidine labeling indices (LI), including cortical and medullary tubules and interstitium. The extent of increase was directly correlated with increasing severity of the nephropathy. Atrophic, degenerative, and hyperplastic cortical tubules in areas of nephropathy had LI eight to nine times greater than nonaffected areas and more normal kidneys. These observations suggest that the hyperplastic responses of renal tubules to the unknown etiologic agents of aging nephropathy may be similar to those of tubules responding to chemical toxins.     

苦马豆素对新生SD大鼠大脑皮质神经细胞形态学损伤作用的研究

通过建立新生SD大鼠大脑皮质神经细胞原代体外培养模型,采用MTT法测定一个生长周期内神经细胞的活性分布,运用寇氏法计算苦马豆素对大鼠大脑皮质神经细胞的IC50。然后用不同质量浓度苦马豆素染毒12h,倒置相差显微镜观察神经细胞形态并测量其胞体短直径和突起长度的变化。结果显示,一个生长周期内的大鼠大脑皮质神经细胞活力最强为培养第5天,苦马豆素对大鼠大脑皮质神经细胞的IC50为0.851 1g/L。与对照组相比,各试验组神经细胞密度降低,神经网络减少;除0.5g/L试验组外,其他各试验组神经细胞胞体短直径显著减小（P〈0.05）,突起长度显著变短（P〈0.05）,但组间差异不显著（P〉0.05）。结果表明,苦马豆素能明显影响新生大鼠大脑皮质神经细胞的生长发育,苦马豆素作用质量浓度与神经细胞形态改变存在明显剂量-效应关系。     

Mycotoxicosis produced in swine by cultural products of an isolate of Aspergillus ochraceus. I. Clinical observations and pathology.

Pigs fed a ration, 25% of which was rice culture, of Aspergillus ochraceus lost weight or failed to gain and became depressed. Some pigs died and most developed subcutaneous edema, hydrothorax, hydroperitoneum, pulmonary atelectasis, edema of the mesentery and perirenal edema. Microscopic lesions in addition to edema were primarily renal and consisted of tubular degeneration and necrosis, hyaline tubular casts, interstitial fibrosis and tubular cell regeneration. The first change found after 3 days was cytoplasmic vacuolation of the convoluted and straight segments of the proximal tubules. Necrotic proximal tubules were found after 4 days and after 9 days degeneration and necrosis involved predominantly proximal tubular segments. Pigs fed a ration, 12.5% of which was rice culture, for 8 weeks did not develop perirenal edema but had firm kidneys. Extensive interstitial fibrosis of the cortical labyrinth was the principal change. Within the fibrous connective tissue, some tubules were necrotic and others were atrophied.     

磺胺类药物对猪肾脏损害的病理学观察

对14例含有磺胺结晶的猪肾脏用10%中性福尔马林固定,常规石蜡切片技术切片染色,对肾脏进行组织病理学观察。结果显示,皮质区肾小管上皮细胞肿胀变性、髄质区肾小管破坏较为严重,大部分肾小管、集合管上皮细胞脱落、变性坏死,并引起梗阻性肾病,同时,肾小球囊腔扩张、血管球萎缩。结果证实,超剂量或长期使用磺胺类药物会严重损害肾实质,导致肾功能下降甚至肾衰竭。     

Acute airsacculitis in turkeys inoculated with phorbol myristate acetate

Phorbol myristate acetate (PMA), which induces acute pulmonary injury in mammals, induced acute airsacculitis in turkeys after intra-airsac inoculation of 0.1 mg/kg. Grossly, air sacs contained multifocal to diffuse hemorrhage and edema at postinoculation hours (PIH) 3 and 6. Microscopically, there was multifocal congestion and small thrombocyte aggregates within small blood vessels by PIH 0.5, with a few vessels containing small numbers of marginating heterophils. By PIH 1.5, thrombocyte aggregates were larger and more numerous, and moderate numbers of heterophils were located perivascularly. Erythrocytes and proteinaceous fluid were in air sac interstitium. By PIH 3 and 6, hemorrhage and exudation of proteinaceous fluid had increased, in some instances severely distending the air sac. Ultrastructurally, changes resulting from PMA-induced injury were thrombocyte aggregation and degeneration, air sac epithelial cell vacuolation with separation of interdigitating cell processes, and endothelial cell vacuolar degeneration with loss of vascular integrity. Air sac lavage fluids had mildly increased total cell counts by PIH 1.5, but values returned to baseline by the end of the experiment, indicating lack of cell exudation into the air sac lumen. Circulating leukocyte changes included transient lymphopenia at PIH 3 and marked heterophilia at PIH 6. These results indicate that thrombocytes and/or heterophils are central to the pathogenesis of injury induced in air sacs by PMA and that the air sac responds differently to PMA than to pathogenic bacteria.     

Relationship of Cell Proliferating Marker Expressions with PGE(2) Receptors in Regenerating Rat Renal Tubules after Cisplatin Injection

Cisplatin, an anticancer drug, is well known to have nephrotoxicity as an adverse effect. We investigated the expressions of cell cycle markers and prostaglandin E(2) (PGE(2)) receptors (EP) in the affected renal tubules in rats injected with a single dose (6 mg/kg body weight) of cisplatin. On days 1-3 after dosing, the affected renal epithelial cells were almost desquamated, showing necrosis. On day 5 onwards, the renal tubules were rimmed by flattened or cuboidal epithelial cells with basophilic cytoplasm; BrdU-immunopositive cells began to significantly increase, indicating regeneration. Simultaneously, TUNEL-positive apoptotic cells were also seen. On days 1-5, cyclin D1-immunopositive cells were decreased with an increased expression in p21 mRNA, indicating G(1) arrest in the cell cycle. The affected renal epithelial cells began to react to EP4 receptor, but not to EP2 receptor. Some EP4 receptor-reacting epithelial cells gave a positive reaction to BrdU or cyclin D1. Collectively, the affected renal tubules underwent various alterations such as necrosis, apoptosis, regeneration and G(1) arrest; the aspects might be influenced by endogenous PGE(2) through EP4 receptor.     

THE HISTOPATHOLOGY OF INFECTIOUS BRONCHITIS IN FOWLS INFECTED WITH A NEPHROTROPIC "T" STRAIN OF VIRUS

The histopathology of the infectious bronchitis caused by the Cumming "T" strain of virus is described in fowls exposed to infection by an aerosol method. Desquamation of the ciliated and glandular epithelium throughout the trachea was seen 24 hours after exposure to virus. This was followed by rapid proliferation presumably of residual basal cells with the production of a stratified undifferentiated epithelial covering. Small areas of the tracheal submucosa showed lymphocytic infiltration by the 4th day. Cilia were first observed in the regenerating epithelium on the 7th day when mucous cells were also seen to be numerous. Alveolar mucous glands developed over the following 4 days and by the 12th day regeneration appeared complete. Pulmonary lesions were generally not severe and the air sacs were only slightly oedematous for 4 days following exposure. Necrosis of a few tubules scattered throughout the kidneys was seen on the 4th day. By the 6th day cystic tubules containing epithelial debris and polymorphonuclear leukocytes were prominent in both cortex and medulla and necrotic tubules were scattered throughout the kidneys. PAS positive granules were present in the renal tubular epithelium and were most pronounced in the distal convoluted tubules. Infiltration of the interstitium by lymphocytes and plasma cells was generally marked on the 7th day. The cytoplasm of these plasma cells was strongly PAS positive and such cells were most numerous on the 12th and 13th days after exposure and then their numbers rapidly declined. Regeneration of tubular epithelium was advanced by the 10th day and much of the cell debris had been cleared from the lumina of the tubules. What appeared to be compressed areas were seen in the cortex from the 13th day where glomeruli and tubules were numerous through considerably reduced in size. These were not seen after the 35th day, however an occasional lymph nodule persisted in the intersitium.     

Acute airsacculitis in untreated and cyclophosphamide-pretreated broiler chickens inoculated with Escherichia coli or Escherichia coli cell-free culture filtrate.

Ninety commercial broiler chickens were divided into three equal groups; 30 were injected with brain-heart-infusion broth into the cranial thoracic air sacs (controls), 30 were similarly inoculated with a culture of Escherichia coli, and 30 were similarly inoculated with E. coli cell-free culture filtrate. Birds were examined from 0 to 6 hours post-inoculation. E. coli-inoculated and cell-free culture filtrate-inoculated chickens reacted similarly, with exudation of heterophils into the air sac. Microscopically, heterophils were present in low numbers perivascularly 0.5 hour after inoculation and became more numerous by 3 hours post-inoculation. By 6 hours post-inoculation, there was severe swelling of air sac epithelial cells and thickening of the air sac by proteinaceous fluid and heterophils. Ultrastructurally, air sac epithelial cells were swollen and vacuolated, and interdigitating processes were separated. Histologically and ultrastructurally, all features in control chickens were normal, with only rare heterophils in the air sac interstitium. In E. coli-inoculated and cell-free culture filtrate-inoculated chickens, cell counts (predominantly heterophils) in air sac lavage fluids increased markedly at 3 and 6 hours, with only slight increases in counts from lavages of controls. Heteropenia was observed in E. coli-inoculated chickens, whereas heterophilia was observed in cell-free filtrate chickens and controls. Ninety additional chickens were pretreated with cyclophosphamide, subdivided into three equal groups, and inoculated and examined similarly as above. Cyclophosphamide pretreatment reduced inflammatory changes in air sacs, lowered cell numbers in lavage fluids, and abolished hematologic changes; however, it did not prevent epithelial cell changes. These results indicate that cell-free culture filtrate of E. coli induces changes similar to those induced by cultures of E. coli.     

Apoptosis of proliferative cortical tubular epithelia in chronic progressive nephrosis of rats

To investigate the role of apoptosis in the pathogenesis of rat chronic progressive nephrosis (CPN), the kidney of male F344/DuCrj rats, 19, 59, and 111 weeks of age, was examined histologically. In situ analysis for DNA fragmentation and proliferating cell nuclear antigen (PCNA) was performed simultaneously by TdT-mediated dUTP-biotin nick end labeling (TUNEL) and immunohistochemistry, respectively. CPN was seen in all the kidneys of 59-week-old (n=6) and 111-week-old rats (n=16), correlating significantly (p<0.01) with age. There were apoptotic bodies (ABs) in the single-layered epithelia of dilated tubules (SLD) and the multilayered epithelia (ML) of the cortical tubules. There were no ABs in any of the kidneys of the 19-week-old (n=5) or 59-week-old rats (n=6). Proliferative activity might have been enhanced in the single-layered and flattened epithelia, SLD, and ML of the cortical tubules in the kidneys of the 59-week-old rats (n=6) compared with that in 111-week-old rats (n=8). The correlations between the TUNEL-positive ratio and number of PCNA-positive cells, and age and the CPN grade were significant (p<0.01) exclusively in the ML. Thus, the results suggest that apoptosis occurs in the proliferative ML of rat CPN, and the pathological significance might be the removal of abnormal or excess cells.     

Age-related pathophysiological changes in rats with unilateral renal agenesis

Affected rats of the unilateral urogenital anomalies (UUA) strain show renal agenesis restricted to the left side. To determine whether unilateral renal agenesis is a risk factor for the progression of renal insufficiency, we studied age-related pathophysiological alterations in affected rats. Although body growth and food intake were normal, polydipsia and polyuria with low specific gravity were present at 10 weeks and deteriorated further with age. Blood hemoglobin concentrations were normal, though there was slight erythropenia with increased MCV and MCH. Although hypoalbuminemia, hypercholesterolemia, azotemia, and hypermagnesemia were manifested after age 20 weeks, neither hyperphosphatemia nor hypocalcemia was observed. Plasma Cre and UN concentrations gradually increased with age. Cre clearance was almost normal, whereas fractional UN excretion was consistently lower than normal. Proteinuria increased with age, and albumin was the major leakage protein. In addition to cortical lesions, dilated tubules, cast formation, and interstitial fibrosis were observed in the renal medulla of 50 week-old affected rats. Renal weight was increased 1.7-fold and glomerular number 1.2-fold compared with normal rats. These findings show that the remaining kidney in UUA rats is involved not only in compensatory reactions but experiences pathophysiological alterations associated with progressive renal insufficiency.     

The pathology of nephrotoxicity of gentamicin in snakes. A model for reptilian gout.

Two gopher snakes (Pitophis melanoleucus catenifer) each were given 5 mg/kg body weight gentamicin every 72 hours (group 1); two snakes each were given 5 mg/kg/day (group 2). Doses for both groups were given over a 2-week period. After the second week, the dose for one snake in each group was increased to 50 mg/kg/day for 2 more weeks and then discontinued. Weekly renal biopsies taken from snakes in group 1 showed no abnormalities by light microscopy during and at the completion of the experiment. Snakes in group 2 had cloudy swelling of the proximal tubules at 2 and 4 weeks after the gentamicin was administered. Snakes given the high dose of gentamicin had hydropic degeneration of the proximal tubules 2 weeks after the dose was raised to 50 mg/kg/day. This progressed to tubular necrosis 1 week after the gentamicin was discontinued. These snakes (high dose) also developed visceral gout, apparently as the result of the extensive tubular necrosis. Tophi were in the pericardium, serosal membranes and parenchyma of the kidneys, liver, spleen and lungs.     

Microscopic and ultrastructural renal pathology of oosporein-induced toxicosis in broiler chicks

Kidneys from broiler chicks receiving 300 micrograms of oosporein K salt per gram of feed continuously from 0 to 21 days of age were examined by light and electron microscopy. Chicks that died at 3 days had nephrosis of initial proximal tubular segments with an early pyogranulomatous interstitial response. Macula densa cells had cytoplasmic accumulations of periodic-acid-Schiff-positive granules. Kidneys from chicks surviving 21 days had hypercellular or atrophic glomeruli and hyperplastic dilated proximal tubules. Centrilobular distal tubules were dilated and filled with hyaline basophilic casts. Interstitial fibrosis was prominent in cortical and medullary zones. These findings indicate that oral oosporein is a severe nephrotoxin which can cause visceral urate deposition and severe nephrosis of initial proximal tubular segments. The histopathology of this mycotoxicosis was compared with those of infectious-bronchitis-induced nephrosis and avian urolithiasis syndrome.