Ochratoxin A and citrinin induced nephrosis in Beagle dogs. III. Terminal renal ultrastructural alterations

The extent and type of renal ultrastructural changes in Beagle dogs varied with the administration of ochratoxin A and citrinin alone and in the two dosage combinations. The three predominant changes were cytoplasmic vacuolation, myelin figure formation and lesions designated as cytoplasmic disarray. These changes were mainly of the endomembane system of the tubular epithelial cells. Cytoplasmic vacuoles were within proximal and distal tubules and collecting ducts and were most numerous in dogs given 10 mg/kg critrinin. Vacuolation of similar distribution, but less severe, was seen in renal tubular cells of dogs given the higher dose of the combined mycotoxins (0.2 mg/kg ochratoxin A + 10 mg/kg citrinin). This damage was limited to the proximal tubular cells in dogs given only ochratoxin A (0.1 or 0.2 mg/kg). Myelin figures were in proximal epithelial cells of dogs given ochratoxin A alone or combined with citrinin. There was cytoplasmic disarray in dogs of all groups except for dogs given 5 mg/kg citrinin. This lesions was usually limited to the proximal tubules. The lesions, however, was found in cells of the distal tubules of dogs given 10 mg/kg citrinin alone.     

Differential alterations in ultrastructural morphology of chicken heterophils and lymphocytes induced by corticosterone and lipopolysaccharide

Birds are continuously confronted by a large number of stressors, including pathogens. Despite their variety, all stressors induce an elevation in plasma corticosterone concentration, and consequently increase heterophil to leukocyte (H/L) ratio. In order to evaluate and differentiate effects of endocrine (non-bacterial) and bacterial stress on the proportions and ultrastructural characteristics of chicken leukocytes, a series of experiments were conducted with seven-week old chickens exposed either to dietary corticosterone or to intravenous (i.v.)-injected lipopolysaccharide (LPS). Samples were taken for haematological, endocrine, and electron microscopy examination. Administration of corticosterone and LPS significantly elevated plasma corticosterone concentrations and increased H/L ratios. Electron microscopy observations indicated changes in heterophil size, shape, and granulation, and lymphocyte cytoplasmic characteristics. Immature heterophils were observed in the peripheral blood, suggesting that corticosterone and LPS both stimulate an earlier release of heterophils from bone marrow and enhance their influx into blood circulation. The LPS induced a degenerative morphology and the destruction of lymphocytes, whereas corticosterone appeared to stimulate their redistribution rather than destruction. The results indicate that exposure to corticosterone or LPS similarly increase H/L ratios, but differentially alter the ultrastructure of heterophils and lymphocytes. Elucidation of the mechanisms that cause such changes may play an important role in distinguishing between a nonimmune and immune stress challenge at the molecular level.     

Early histopathologic and ultrastructural alterations in femorotibial joints of partial medial meniscectomized guinea pigs

The articular cartilage from femorotibial joints of partial medial meniscectomized male guinea pigs was evaluated at 24, 48, 72, and 96 hours post-surgery to determine the sequential histopathologic and ultrastructural alterations. At 24 hours post-surgery, histopathologic alterations were in the superficial and middle layers and consisted of degeneration and necrosis of chondrocytes and minimal decreased intensity of toluidine blue matrix staining. Changes in chondrocytes and matrix became progressively more extensive 48 hours after surgery. Ultrastructurally, the changes in the superficial matrix appeared to be the result of loss of the fine granular material interspersed between collagen fibers. At 72 and 96 hours post-surgery, chondrocyte loss was extensive and surface fibrillation was seen. These findings suggested that chondrocyte death was the initial important event which led to progressive severe cartilage degeneration in this model.     

Citrinin mycotoxicosis in the rabbit: ultrastructural alterations

Citrinin was given to rabbits as a single oral dose of 120 or 67 mg/kg. Rabbits were killed at 4, 6, 8, 10, and 12 hours post dosing, and the kidneys were fixed by intravascular perfusion. Ultrastructural alterations were evident by 4 hours after treatment. In the proximal tubule, alterations were brush border disruption, cytoplasmic rarefaction, and swelling of interdigitating processes. At higher doses, mitochondria were condensed and distorted. Medullary and straight cortical distal tubules had marked distention of the intercellular spaces and disorganization of interdigitating processes. Changes in cortical and outer medullary collecting ducts were similar but less severe. Renal alterations were suggestive of damage to membrane structure and/or transport functions and interference with cellular bioenergetics. Leukocytic infiltration was associated with damaged tubules indicating a contribution of inflammation to the development of the lesions.     

Adenocarcinoma of the salivary gland in a white Swiss mouse.

A salivary gland adenocarcinoma in a white Swiss mouse used in a titration of the scrapie agent is reported. The neoplasm originated from the serous cells of the parotid salivary gland. Retroviral particles were detected in the neoplastic salivary gland cells by electron microscopy.     

Tissue gamma-glutamyl transpeptidase activity and hepatic ultrastructural alterations in dogs with experimentally induced glucocorticoid hepatopathy

Glucocorticoid hepatopathy was induced in 2 Beagle dogs with IM injections of prednisone, 4.4 mg/kg, given once daily for 14 consecutive days. Serum enzymatic activities were monitored and percutaneous hepatic biopsy materials were collected. A placebo-treated group of 2 Beagle dogs was given saline solution injections. Treated dogs showed clinical signs of Cushing's disease and alterations in mean serum enzymatic activities consistent with glucocorticoid hepatopathy. The gamma-glutamyl transpeptidase activities in placebo-treated dogs were highest for kidney, less (but marked) for pancreas, and least for liver, gallbladder, jejunum, duodenum, spleen, heart, lung, skeletal muscle, and erythrocytes. In treated dogs, the gamma-glutamyl transpeptidase activities were highest for pancreas and were decreased for kidney and slightly increased for the other tissues. Results of hepatic biopsy and necropsy examinations of treated dogs showed swollen, pale, friable hepatic parenchyma with hepatocytic cytoplasmic vacuolation and glycogen accumulation. Extrahepatic lesions included gastric ulceration, catarrhal enteritis, splenic and lymph node atrophy and lymphocytolysis, and vacuolation of adrenal cortical cells in the zona fasciculata. Ultrastructural study of liver from dogs with glucocorticoid hepatopathy indicated that the principle alterations were abundant glycogen accumulation and few mitochondria in hepatocytes.     

使用超净工作台实施子宫摘除术净化ICR小鼠的研究

为了建立SPF级远交系ICR小鼠种群。使用超净工作台实施子宫摘除术净化小鼠,结果:使用上述方法成功剖腹孕鼠20只,得到净化小鼠140只,育成小鼠120只,检测各项指标符合SPF级标准。结论:在普通环境中使用超净工作台实施子宫摘除术净化ICR小鼠,是建立SPF级种群唯一经济有效的方法。     

Histopathologic alterations induced in the lungs of sheep by use of alpha2-adrenergic receptor agonists

OBJECTIVE: To study effects of central- and peripheral-acting alpha2-adrenergic receptor agonists on lung parenchyma, platelets, and pulmonary intravascular macrophages (PIM) of sheep. ANIMALS: 12 healthy mature female sheep. PROCEDURE: Group-1 (control, n = 2) sheep received 5 ml of physiologic saline solution IV and were euthanatized 3 minutes later. Sheep of group 2 (n = 8) received xylazine (150 microg/kg of body weight, IV), then 2 sheep each were euthanatized 3, 10, or 60 minutes, or 12 hours later. Sheep (n = 2) of group 3 were given ST-91 (30 microg/kg, IV), then were euthanatized 3 minutes later. Immediately after euthanasia, the lungs were fixed intratracheally and tissue was obtained for light and electron microscopy after 1 hour. RESULTS: Pulmonary parenchymal damage or morphologic alterations in PIM and platelets were not evident in control sheep. Three minutes after xylazine administration, morphologic changes in PIM were appreciable. After 10 minutes, extensive damage to the capillary endothelium and alveolar type-I cells, intra-alveolar hemorrhage, and interstitial and alveolar edema were evident. Most PIM had complete internalization of the surface coat. Similar changes were seen 60 minutes after xylazine administration; however, by 12 hours, morphologic features of PIM and lung parenchyma were almost completely restored. Evidence of PIM activation, obvious damage to capillary endothelium, and extensive pulmonary edema also were evident 3 minutes after ST-91 administration. CONCLUSIONS: XYLAZINE induces severe pulmonary parenchymal damage when administered at clinical sedative doses in sheep; morphologic changes in PIM within 3 minutes after administration of these drugs are substantial; and platelet aggregation is not apparent.     

Improved development of ICR mouse 2-cell embryos by the addition of amino acids to a serum-, phosphate-and glucose-free medium

This study was conducted to evaluate how exogenous amino acids could affect preimplantation development of ICR mouse embryos. Two-cell embryos collected from naturally mated mice were cultured in amino acid-, glucose- and phosphate-free preimplantation (P)-1 medium. In Experiments 1, 19 amino acids (aa; 1% and 0.5% of MEM essential and nonessential amino acid solutions, respectively) were added to P-1 medium supplemented with either fatty acid-free bovine serum albumin (BSA; 3 mg/mL) or human follicular fluid (hFF; 10%). Regardless of BSA or hFF addition, embryo development to the morula (84 to 86% vs. 97 to 100%) and the blastocyst (54% vs. 93 to 94%) stages was significantly (P<0.05) enhanced by the addition of aa compared with no addition. In Experiment 2, the cell number of blastomeres and inner cell mass (ICM) cells in blastocysts and the ratio of ICM cell to trophectodermal cell (TE) were evaluated after aa addition. In both BSA- and hFF-containing P-1 medium, a significant increase in total blastomere number were found after aa addition (47 to 52 vs. 62 to 63 cells) compared with no addition. However, the ICM/TE ratio was not significantly affected by aa supplementation in both media, while ICM cell number was greatly increased after aa addition in hFF-containing medium (12 vs. 17 cells). When blastocysts were further cultured up to 162 hr post-hCG injection, development to the hatched blastocyst stage was significantly promoted by aa addition (0% vs. 11 to 20%) in both BSA- and hFF-containing media. In conclusion, aa significantly promote the preimplantation development to the hatched blastocyst stage and such effect mainly exerted on supporting blastomere proliferation.     

Early renal ultrasonographic findings in dogs with experimentally induced ethylene glycol nephrosis

Renal ultrasonographic changes were evaluated in 5 dogs administered 10 ml of commercial antifreeze (95% ethylene glycol)/kg of body weight, PO, and in 2 dogs given placebos. Studies were made prior to and after ingestion on an hourly basis over a period of 8 to 10 hours. All dogs were anesthetized immediately after toxin or placebo ingestion for the duration of the study. Renal cortical echogenicity was evaluated in comparison with that of the adjacent liver and spleen. Echogenicity of the renal medulla and definition of the corticomedullary junction were assessed. Within 4 hours after ethylene glycol administration, renal cortical echogenicity of all intoxicated dogs increased from normal to surpass that of liver and approach or equal that of the spleen. Medullary echogenicity in all intoxicated dogs progressively increased over the course of the study, with changes recognized within 5 hours after ethylene glycol administration. An ultrasonographic pattern consisting of nearly equal, marked increase in cortical and medullary echogenicity and relatively hypoechoic corticomedullary junction and central medullary regions was recognized concurrent with the development of anuria in 3 of the 5 intoxicated dogs. Mild, transient increases in cortical and medullary echogenicity were observed in anesthetized control dogs. However, no statistical difference (P less than 0.05) was detected between baseline, peak, and terminal echogenicity values in these dogs. Blood and urine samples were collected hourly from intoxicated dogs to coincide with ultrasonographic studies. Most clinicopathologic values derived from these samples were not statistically different (P less than 0.05) from those reported in a study that used a similar intoxication protocol in nonanesthetized dogs.     

Experimental transplantation models of mouse sarcoma 180 in ICR mice for evaluation of anti-tumor drugs.

Two new experimental models of transplantable mouse sarcoma 180 were developed in ICR mice in order to examine the optimum transplantation sites and methods. The cervicodorsal hypoderm was evaluated as the best transplantation site for mouse sarcoma 180 among seemingly usable transplantation sites such as groin, armpit, cervicodorsal, abdominal and lumbodorsal hypoderms by hypodermic transplantation. In addition, the lung transplantation model was established by monitoring the survival period as a reliable parameter for evaluation of anti-tumor effects.     

Burro aortic collagen: platelet aggregating activity and ultrastructural changes induced by plasma.

A fibrillar collagen molecule was extracted from the upper thoracic aorta of an old burro (Equus asinus). Presence of the collagen in the extract was determined by amino acid analysis, scanning and transmission electron microscopy, incubation with collagenase, and assays of its platelet-aggregating capacity by "aggregometry". Based on the amino acid rations of proline/hydroxyproline and lysine/hydroxylysine, the collagenous protein most nearly resembles type I of 4 main published types of collagen. Quantitative assays of the collagen as a mediator of platelet aggregation showed human platelets more sensitive and sheep platelets slightly less sensitive than burro platelets. Incubation with collagenase abolished platelet aggregation capacity and converted the fibrillar collagen to a gel-like mass. Incubation with galactose oxidase neither lessened nor intensified the collagen-mediated platelet aggregation. Incubation with burro plasma decreased platelet aggregating activity and changed the collagen ultrastructure (demonstrated with scanning electron microscopic imaging). The significance of a naturally occurring plasma (protein) factor(s) which may have a regulatory role in reducing the chemical activity of the fibrillar collagen molecule with platelets is also discussed.     

Phenoxy-acid induced renal changes in the chicken. I. Ultrastructure

Forty-five day-old broiler chicks were equally divided into 3 groups, 2 being fed 2,4-D and 2,4,5-T, respectively, from the fifth day of life for up to 7 months, at 1,000 p.p.m. in the drinking water, and the third serving as a control. From 8 weeks of age 2 of the control animals were fed 2,4-D at the same rate for 7 months.Seven of the treated animals died, or were killed in a moribund state, during the experiment (Table 1), the survivors showing only slight signs of poisoning such as reduced mobility and food and water intakes.Animals were sacrificed after varying time intervals (Table 1). The tissue distribution patterns of 2,4-D and 2,4,5-T, as determined in selected tissues of a few of the animals (Table 2), were similar to that observed earlier with 2,4-D.Both compounds produced qualitatively similar morphological effects, although the action of 2,4,5-T apparently was somewhat more intense.The predominant necropsy finding was kidney enlargement (Table 1) due to hypertrophy of the proximal convoluted tubular epithelium (Fig. 1).Electron-microscopically, increased numbers of mitochondria were demonstrated in the tubular cells, with variations in mitochondrial size, shape and structure (Figs. 4–7). The number of micro-bodies was also definitely increased (Figs. 2 and 4). In the nuclei nuclear bodies were observed (Figs. 2 and 3).The significance of the findings is discussed.     

Characteristics of cytotoxic cells induced by Toxoplasma lysate antigen in mouse spleen.

Spleen cells from Toxoplasma lysate antigen (TLA)-sensitized BALB/c mice showed the strong cytotoxic activity against both natural killer (NK)-sensitive cells (YAC-1 and RL male-1) and NK-insensitive cells (P-815), when incubated with TLA or recombinant human IL-2 (rhIL-2). The increment of TLA concentration in culture medium increased the cytotoxic activity. Treatment of effector cells; spleen cells from TLA-sensitized mice incubated with TLA, with anti-asialo GM1 or anti-Thy-1 plus complement inhibited the cytotoxic activity of effector cells, whereas treatment with anti-mouse Lyt-2.2 serum plus complement had no effect on the cytotoxic activity. Treatment of spleen cells from TLA-sensitized mice with anti-asialo GM1 and/or anti-Thy-1 plus complement inhibited cytotoxic activities of effector cells. These results suggested that spleen cells sensitized with TLA both in vivo and in vitro were asialo GM1 positive and Thy-1 positive, and the majority of cytotoxic cells induced by TLA were similar to lymphokine-activated killer (LAK) cells induced by IL-2.     

Spontaneous extraskeletal osteosarcoma with various histological growth patterns in the abdominal wall of an ICR mouse

Extraskeletal osteosarcoma is extremely rare in mice. This case report demonstrates a spontaneous murine extraskeletal osteosarcoma that exhibited various histological growth patterns in an ICR mouse. At necropsy, the tumor mass was located in the abdominal wall and was 45 × 30 × 25 mm in size. Histopathologically, the tumor showed the following four growth patterns: a solid pattern of polygonal cells embedded in an osteoid eosinophilic matrix with calcification, an irregular sheet pattern of short spindle cells accompanying some eosinophilic multinucleated cells, a fascicular pattern of spindle cells and a cystic pattern lined by short spindle cells. Immunohistochemically, most of the tumor cells were positive for vimentin, proliferating cell nuclear antigen and osterix. The multinucleated cells mentioned above were desmin positive and were regarded as regenerative striated muscles but not tumor cells. Since no clear continuity with normal bone tissues was observed, the tumor was diagnosed as an “extraskeletal osteosarcoma.”     

Early embryonic death in lambs induced by Veratrum californicum

Both field and laboratory observations have suggested the possibility of embryonic death from 14th day ingestion of Veratrum californicum by pregnant sheep. An experiment was conducted to tabulate the incidence of embryonic death from 14th day ingestion of high doses of plant material. Six of eight ewes so dosed were non-pregnant at term (75%), compared to none in controls, and were, therefore, believed to have experienced embryonic death from the plant ingestion. Results suggest that ingestion of plant material could account for many open ewes at lambing time in ranching operations where Veratrum has been ingested in early gestation.     

Characterization of the renal response to protein ingestion in dogs with experimentally induced renal failure.

Effects of a protein meal (2.7 g of casein/kg of body weight) on glomerular filtration rate (GFR) and renal plasma flow (RPF) were assessed in dogs after 15/16 nephrectomy (n = 10), and were compared with observations in dogs with intact kidneys (n = 5). Increase in GFR and RPF was observed in both groups of dogs between 1.5 and 8 hours after protein ingestion. A maximal value for GFR was observed between 4 and 5 hours after protein ingestion in dogs of both groups. Enhancement of urinary protein excretion was evident in partially nephrectomized dogs after protein ingestion (P less than 0.05), a result that was confirmed by 24-hour total urine collection from partially nephrectomized dogs fed a balanced ration. A qualitatively similar vasodilatory response was observed in partially nephrectomized dogs and in dogs with intact kidneys, and the mean maximal increase of GFR and RPF expressed as a percentage of baseline values in the latter dogs (47.0 +/- 8.1 and 43.6 +/- 10.3%, respectively) exceeded that observed in partially nephrectomized dogs (20.8 +/- 2.2 and 22.7 +/- 6.3%, respectively; P less than 0.01). The incremental response of the kidneys to protein ingestion was directly related to the degree of renal function, as reflected in the linear regression relationship between the incremental increase in GFR and the baseline value for GFR (P less than 0.01, R2 = 0.721).