Ultrastructural Lesions Research Articles

Regulatory effects of sulfur dioxide on the development of atherosclerotic lesions and vascular hydrogen sulfide in atherosclerotic rats

ObjectiveThis study was designed to examine the effect of sulfur dioxide (SO2) on atherosclerotic progression and endogenous vascular hydrogen sulfide (H2S) in rats with atherosclerosis (AS). MethodsTwenty-eight male rats were randomly divided into control, AS and AS+SO2 groups. Rats were given a single dose of vitamin D3 and fed a high-cholesterol diet for 8 weeks to induce AS. Plasma lipids, aortic ultrastructure, and atherosclerotic lesions were detected at the termination of experiment. Plasma and aortic SO2 were measured using high-performance liquid chromatography, and aspartate aminotransferase (AAT) 1 and AAT2 mRNAs were detected by real-time PCR. Plasma and aortic H2S levels were determined with a sulfide-sensitive electrode. Cystathionine-γ-lyase (CSE) mRNA and protein expression was detected. Plasma glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities, malondialdehyde (MDA) and nitric oxide (NO) contents, inducible NO synthase (iNOS) and eNOS activities, and aortic SOD1 and SOD2 expressions were detected. ResultsMarked atherosclerotic lesions with elevated levels of TC and LDL-C were observed in AS rats. While, there were decreased plasma SO2 levels and aortic SO2 production, with a reduced aortic AAT activity in atherosclerotic rats. Plasma GSH-Px and SOD activities were decreased but MDA level increased. Plasma NO content and iNOS activity were also increased. SO2 donor, however, significantly decreased the atherosclerotic lesions with an increased aortic H2S/CSE pathway. It elevated plasma GSH-Px and SOD activities, reduced plasma MDA level, and increased NO/NOS pathway. ConclusionsSO2 has a marked anti-atherogenic effect with an increase in endogenous H2S production in rats with AS.

A comparison study on histopathology and ultrastructure of lesions from patients with bullous ichthyosiform erythrodermia before and after treatment with acitretin.

Objective To investigate the effect of acitretin on the histopathology and ultrastructure of lesions from patients with bullous ichthyosiform erythrodermia (BIE), and to explore mechanisms underlying the modulation of keratinization process by acitretin. Methods Lesional tissue was obtained from the back of 4 patients with BIE before and after the treatment with acitretin. Light microscopy and transmission electron microscopy were performed to observe histopathological and ultrastructural changes in these lesions. Results After treatment, the improvement in clinical manifestations was more than 75% in all the 4 patients, and reached 90% in 1 of the 4 patients. As histopathology and ultrastructural study showed, there was an obvious improvement in hyperkeratosis and continuity of extra cellular lamellar membrane, and a decrease in keratin deposition in prickle and granular layer, but no remarkable changes were observed for the proliferation of prickle cells or acantholysis. Conclusions Acitretin shows a favorable efficacy in clinical treatment of BIE,with histopathological and ultrastructural improvement mainly located in the stratum corneum. The modulation of keratinization process in keratinocytes by acitretin appears more apparent in granular and corneum layers. Key words: Ichthyosis; Acitretin; Microscopy,electron,transmission

Intracellular accumulation of cell cycle regulatory proteins and nucleolin re-localization are associated with pre-lethal ultrastructural lesions in circulating T lymphocytes: The HIV-induced cell cycle dysregulation revisited

The HIV-induced demise of CD4-T cells is thought to be a result of the execution of genetically programmed cell death that occurs in lymphoid tissue, where many resident T cells are chronically hyperactivated. Since HIV-induced alterations of cell cycle control has been often indicated as prominent mechanism of immune hyper activation and cause of apoptotic death, the signal pathway involved in cell cycle dysregulation of T lymphocytes from HIV infected patients was extensively studied.Here, we also demonstrate that circulating T lymphocytes leave lymphoid tissues with diffused regressive lesions (vacuolization, blebbing, nuclear evanescence and organelle swelling). Equally diffused are biochemical anomalies that accompany the overall disarrangement of cell structure, particularly the fragmentation and diffusion into the cytoplasm of C23/nucleolin, the intracellular accumulation of short lived regulatory proteins and the decrease in expression of membrane proteins.All this is something more than a cell cycle-related remodelling of cell morphology and biochemical mechanisms, and rather recalls a necrotic/oncotic cell damage. Since these changes are associated with adaptive mechanisms to hypoxia, we give evidence for alteration of cell cycle control developing in conditions of scarce energy supply.

The cyclophilin inhibitor Debio 025 normalizes mitochondrial function, muscle apoptosis and ultrastructural defects in Col6a1−/− myopathic mice

We have investigated the therapeutic effects of the selective cyclophilin inhibitor D-MeAla(3)-EtVal(4)-cyclosporin (Debio 025) in myopathic Col6a1(-/-) mice, a model of muscular dystrophies due to defects of collagen VI. We studied calcineurin activity based on NFAT translocation; T cell activation based on expression of CD69 and CD25; propensity to open the permeability transition pore in mitochondria and skeletal muscle fibres based on the ability to retain Ca(2+) and on membrane potential, respectively; muscle ultrastructure by electronmicroscopy; and apoptotic rates by terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling assays in Col6a1(-/-) mice before after treatment with Debio 025. Debio 025 did not inhibit calcineurin activity, yet it desensitizes the mitochondrial permeability transition pore in vivo. Treatment with Debio 025 prevented the mitochondrial dysfunction and normalized the apoptotic rates and ultrastructural lesions of myopathic Col6a1(-/-) mice. Desensitization of the mitochondrial permeability transition pore can be achieved by selective inhibition of matrix cyclophilin D without inhibition of calcineurin, resulting in an effective therapy of Col6a1(-/-) myopathic mice. These findings provide an important proof of principle that collagen VI muscular dystrophies can be treated with Debio 025. They represent an essential step towards an effective therapy for Ullrich Congenital Muscular Dystrophy and Bethlem Myopathy, because Debio 025 does not expose patients to the potentially harmful effects of immunosuppression.

Winter fine particulate matter from Milan induces morphological and functional alterations in human pulmonary epithelial cells (A549)

Samples of PM(2.5) were gravimetrically collected during the winter 2005/2006 in the urban area of Milan (North Italy). Samples were chemically characterized and the particles were detached from filters to determine their cytotoxic effects on the A549 cell line. Based on the potential toxicological relevance of its components, Milan winter PM(2.5) contained high concentrations of pro-oxidant transition metals and PAHs, while re-suspended particles showed a relatively high frequency of dimensional classes ranging from 40 nm to 300 nm. A549 cells exposed to particle suspensions showed a concentration-dependent decrease in viability, starting from 10 microg/cm(2). Phagocytosis of particles by A549 cells and particle aggregates were morphologically characterized and seemed to depend on both particle concentration and exposure time, with the majority of particles being engulfed in membrane-bound vacuoles after 24h of exposure. The ability of ultrafine particles to penetrate and spread throughout the cells was also verified. Cell membrane lysis and mitochondrial ultrastructural disruption appeared to be the main modifications induced by PM(2.5) on A549 cells. Concomitantly to the adverse effects observed in terms of cell mortality and ultrastructural lesions, a significant intracellular production of reactive oxygen species (ROS) was observed, suggesting that the cytotoxicity, exerted by the winter PM(2.5) in Milan, derived also from its oxidative potential, probably associated with particle-adsorbed metals and PAHs.

Protective effects of salidroside on oxidative damage in fatigue mice

To study the protective effects of salidroside on oxidative damage in fatigue mice. Thirty-two male Kunming mice were randomly divided into four groups based on body weight: normal control group, salidroside group, training group and salidroside plus training group. The mice in the normal control group and the training group were given distilled water and mice in the salidroside group and the salidroside plus training group were given 180 mg/ (kg * d) salidroside for 15 days. At 30 min after the last administration, the mice in the training group and the salidroside plus training group were forced to swim for 120 min. Finally, all the mice were killed. The activities of lactate dehydrogenase (LDH), creatine kinase (CK) and creatine kinase-myocardial band isoenzyme (CK-MB) in plasma were determined by an auto-biochemistry analyzer. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the content of malonaldehyde (MDA) in liver tissue were also detected. The changes of ultrastructures of the skeletal muscle and cardiac muscle were observed under an electron microscope. Compared with no swimming, long-time swimming could significantly increase the activities of LDH, CK and CK-MB in plasma (P < 0.05, P < 0.01), while salidroside could significantly decrease the activities of CK and CK-MB in plasma induced by long-time swimming (P < 0.05, P < 0.01). There existed interactions in LDH, CK and CK-MB activities between salidroside and long-time swimming (P < 0.05). Compared with no swimming, long-time swimming could significantly decrease the SOD and GSH-Px activities and increase the MDA content in liver tissue (P < 0.01). Salidroside could significantly increase the GSH-Px and SOD activities and decrease the MDA content in liver tissue (P < 0.05, P < 0.01). However, there were no interactions in GSH-Px activity and MDA content between salidroside and long-time swimming (P < 0.05). After long-time swimming, more ultrastructural lesions were found in the cardiac muscle and skeletal muscle in the training group than in the salidroside plus training group. Salidroside may play a role in protecting the mice from oxidative damage caused by long-time endurance training.

Ultrastructural Findings in Lymph Nodes from Pigs Suffering from Naturally Occurring Postweaning Multisystemic Wasting Syndrome

The aims of this study were to evaluate ultrastructural lesions in lymph nodes from postweaning multisystemic wasting syndrome (PMWS)-affected pigs and to correlate these alterations with detection of viral-like particles (VLPs). Samples of lymph nodes were taken from 4 PMWS-affected pigs and 2 healthy animals and processed by transmission electron microscopy. Significant ultrastructural alterations were only noted in PMWS-affected pigs, mainly in histiocytes and rarely in other cell types. Histiocytes showed severe swelling and proliferation of mitochondria, and proliferation and dilation of rough endoplasmic reticulum and Golgi complex. Infected histiocytes contained large numbers of intracytoplasmic inclusion (ICI) bodies with VLPs; some histiocytes also had intranuclear inclusions (INIs). Small inclusions were surrounded by double membrane, with a granular appearance or containing paracrystalline arrays; icosahedral VLPs were 8-17 nm in diameter. Large ICIs were double-membrane bounded or not and contained VLPs usually forming paracrystalline arrays. ICIs were often found next to mitochondria with severe swelling, and also inside them. INIs were not surrounded by membranes and contained virions of 10-13 nm diameter. Lymphocyte depletion was a striking finding of lymph nodes from PMWS-affected pigs. The inclusion bodies containing VLPs referred to in the present study should be classified as viral factories, suggesting that viral replication is probably a frequent event in macrophages, in which mitochondria might play a role.

Spontaneous Lysosomal Storage Disease Caused by Sida carpinifolia (Malvaceae) Poisoning in Cattle

Clinical and pathologic findings for the spontaneous poisoning by Sida carpinifolia in cattle are described in this study. A survey on field cases of S. carpinifolia in cattle was carried out on farms of Alto Vale do Itajaí, State of Santa Catarina, southern Brazil. Sixteen affected animals were clinically evaluated and 9 were subjected to postmortem examination. The main clinical signs consisted of marching gait, alert gaze, head tremors, and poor growth. Histologic and ultrastructural lesions consisted of vacuolization and distension of neuronal perikarya, mainly from Purkinje cells, and of the cytoplasm of acinar pancreatic and thyroid follicular cells. Clinical signs and lesions varied from mild to severe. Improvement of the clinical signs was observed in cattle after a period of up to 90 days without consuming the plant; however, residual lesions, mainly characterized by axonal spheroids and absence of Purkinje neurons in some areas of the cerebellum, were observed in these cases. It is concluded that the natural chronic consumption of S. carpinifolia was the etiologic cause of storage disease in cattle in this study.

Nephrotic Syndrome Induced by Dibasic Sodium Phosphate Injections for Twenty-eight Days in Rats

Sprague-Dawley rats received once daily tail-vein injections of 360 mM dibasic sodium phosphate solution at 8 mL/kg for fourteen or twenty-eight days. Clinical examination revealed persistent proteinuria from three days after the first dosing and thereafter severe proteinuria from eight days or later in the phosphate-treated groups. Proteinuria developed without remission even after fourteen-day withdrawal in the fourteen-day dosed group. Phosphate-treated animals developed lipemia, hypercholesterolemia, anemia, higher serum fibrinogen levels, and lower serum albumin/globulin ratios on day 29. Renal weight increased significantly compared with control animals, and the kidneys appeared pale and enlarged with a rough surface. Histopathologically, glomerular changes consisted of mineralization in whole glomeruli, glomerular capillary dilatation, partial adhesion of glomerular tufts to Bowman's capsule, and mesangiolysis. Ultrastructural lesions such as an increased number of microvilli, effacement of foot processes, and thickening of the glomerular basement membrane, and immunocytochemical changes in podocytes, mainly decreased podoplanin-positive cells and increased desmin expression, were also conspicuous in the phosphate-treated rats for twenty-eight days. Marked tubulointerstitial lesions were tubular regeneration and dilatation, protein casts, mineralization in the basement membrane, focal interstitial inflammation, and fibrosis in the cortex. These clinical and morphological changes were similar to features of human nephrotic syndrome.

Ultrastructural characterization of fresh and cryopreserved in vivo produced ovine embryos

Controlled slow freezing and vitrification have been successfully used for ovine embryo cryopreservation. Selection of embryos for transfer is based on stereomicroscopical embryo scoring after thawing, but the subjectivity inherent to this selection step has been demonstrated by ultrastructural studies of controlled slow frozen, in vivo produced ovine morulae and blastocysts. These studies have shown that certain abnormalities remain undetected by stereomicroscopy only. In the present study, using ovine in vivo produced morulae and blastocysts, we have studied the ultrastructural alterations induced by open pulled straw vitrification (OPS) and controlled slow freezing, compared stereomicroscopical embryo scoring with light microscopy evaluation of embryo's semithin sections, and related the ultrastructural cellular damage with the embryo classification by stereomicroscopical embryo scoring of embryos’ and semithin section evaluation by light microscopy. The ultrastructural lesions found for OPS-vitrified and controlled slow frozen embryos were similar, independently of embryo stage. A significant higher number of grade 3 embryos was found at stereomicroscopical scoring after controlled slow freezing ( P = 0.02), and a significant higher number of grade 3 blastocysts was found at semithin sectioning after OPS vitrification ( P = 0.037). The extension of ultrastructural damage, especially of mitochondria and cytoskeleton, was related to the semithin classification but not to stereomicroscopical scoring at thawing. This suggests that semithin scoring is a useful tool for predicting ultrastructural lesions and new improvements in cryopreservation and thawing methods of ovine embryos are still warranted, including in the case of blastocysts cryopreserved by OPS vitrification.

Deletion of Cd151 Results in a Strain-Dependent Glomerular Disease Due to Severe Alterations of the Glomerular Basement Membrane

Alterations in CD151 have been associated with primary glomerular disease in both humans and mice, implicating CD151 as a key component of the glomerular filtration barrier. CD151 belongs to the tetraspanin family and associates with cell-matrix adhesion complexes such as alpha3beta1-integrin. Here we show that Cd151-deficient mice develop severe kidney disease on an FVB background but are healthy on a B6 background, providing a new and unique tool for the identification of genes that modulate the onset of proteinuria. To better understand the function of CD151 in the kidney, we studied its expression pattern and characterized early ultrastructural defects in Cd151-null kidneys. CD151 is expressed in podocytes of the mouse kidney and co-localizes with alpha3-integrin at the base of podocyte foot processes, at the site of anchorage to the glomerular basement membrane (GBM). Interestingly, the first ultrastructural lesions seen at the onset of proteinuria in Cd151-null kidneys were severe alterations of the GBM, reminiscent of Alport syndrome and consisting of massive thickening and splitting of the GBM. These lesions are associated with increased expression of GBM components. Podocyte abnormalities, effacement of foot processes, and podocyte loss appear to occur consequently to the GBM damage. In conclusion, CD151 appears to be involved in the establishment, maturation, and/or maintenance of the GBM structure in addition to its role in integrin-mediated adhesion strengthening.

Ultrastructure of Placental Hyperplasia in Mice: Comparison of Placental Phenotypes with Three Different Etiologies

Hyperplastic placentas have been reported in several experimental mouse models, including animals produced by somatic cell nuclear transfer, by inter(sub)species hybridization, and by somatic cytoplasm introduction to oocytes followed by intracytoplasmic sperm injection. Of great interest are the gross and histological features common to these placental phenotypes – despite their quite different etiologies – such as the enlargement of the spongiotrophoblast layers. To find morphological clues to the pathways leading to these similar placental phenotypes, we analyzed the ultrastructure of the three different types of hyperplastic placenta. Most cells affected were of trophoblast origin and their subcellular ultrastructural lesions were common to the three groups, e.g., a heavy accumulation of cytoplasmic vacuoles in the trophoblastic cells composing the labyrinthine wall and an increased volume of spongiotrophoblastic cells with extraordinarily dilatated rough endoplasmic reticulum. Although the numbers of trophoblastic glycogen cells were greatly increased, they maintained their normal ultrastructural morphology, including a heavy glycogen deposition throughout the cytoplasm. The fetal endothelium and small vessels were nearly intact. Our ultrastructural study suggests that these three types of placental hyperplasias, with different etiologies, may have common pathological pathways, which probably exclusively affect the development of certain cell types of the trophoblastic lineage during mouse placentation.

Influence of heat shock preconditioning on structure and function of mitochondria in gastric mucosa of severely burned animals: experiment with rats

To investigate the influence of heat shock (HS) preconditioning on the ultra-structure of gastric mucosal cells and the activity of cytochrome oxidase (CCO) and superoxide dismutase (SOD) in mitochondria isolated from gastric mucosa of burned rats in order to investigate its protective mechanism on burn-induced acute gastric mucosal lesion. Ninety-six Wistar rats were divided randomly into two groups:(1) burn model group (n =40) undergoing burning and made into model of acute gastric mucosal lesion; and then subdivided into 5 equal subgroups: 3, 6, 12, 24, and 48 h after burning; (2) normal control group (n = 8); (3) HS preconditioning + burn group (n = 40), undergoing burning 24 h after HS preconditioning; and (4) HS preconditioning group (n = 8), without burn as experimental control A number of rats were sacrificed and laparotomized before and 3, 6, 12, 24, and 48 h after the burning. Specimens were obtained from the gastric antrum, bodies if stomach and gastric lesion to undergo microscopy and determination of the ulcer index ( UI ). Streptavidin-peroxidase immunohistochemistry was used to detect the protein expression of heat shock protein (HSP)-60 and HSP-70. Mitochondria were isolated and the activities of CCO and SOD in mitochondria were measured. The dynamic postburn changes in micro and ultra structure of gastric mucosal cells of scalded rats were observed. The rats of the burn group showed conspicuous gastric mucosal lesions. The UI levels at every time point of the HS group were all the lowest in comparison with other groups. The expression levels of HSP70 and HSP60 of the HS group, especially those at the time points 3, 6, 12, and 24 h were significantly higher than those of the burn group (P <0.05 or P <0.01). The activities of mCCO and mSOD of the HS group did not decrease remarkably at any time point in comparison with the control groups, and the activities of mCCO and mSOD at the time points 6, 12, and 24 h of the HS group were all significantly higher than those of the burn group (P <0.05 of P <0.01). Electron microscopy showed that the ultrastructural lesion was mild and alteration of gastric mucosal mitochondria was not significant in the HS group compared with those of the burn group. A positive correlation was shown between SOD and HSP70 (r = 0.436, P <0.05) and also between CCO and HSP60 (r =0.679, P <0.05). HS preconditioning ameliorates the burn-induced acute gastric mucosal lesion and has a protective role to gastric mucosal mitochondria. The role of HS preconditioning on mitochondria is associated with the protection of the activity of antioxidase and CCO by HSP60 and 70.

Histopathological and ultrastructural studies of a mouse lung model of Campylobacter jejuni infection

Campylobacter jejuni is a major cause of diarrhoea in humans. However, the pathogenesis of C. jejuni diarrhoea is poorly understood due to the lack of a good animal model of infection. Many animals have been tried with limited success, but a mouse lung model of infection has been found to be satisfactory previously; however, the lung pathology of this model has not been studied. For the purpose of characterizing the histopathological and ultrastructural lesions in the lung of the mouse pulmonary model of C. jejuni infection, C. jejuni strain 81-176 or sterile PBS was intranasally inoculated into BALB/c mice. The infection resulted in a mild illness only, and in an initial predominance of polymorphonuclear cells, followed by the accumulation of macrophages and later the prominence of epithelioid cells. Focal peribronchial pneumonia appeared on day 3, granuloma-like reaction on day 4 and bronchopneumonia on day 5 post-infection. These features developed until day 5 post-infection, but were less consistent afterwards when histopathology was monitored up to 9 days post-infection. Intracellular structures resembling bacteria were observed on days 3 and 5 post-infection, but not on day 7 post-infection. On days 3 and 5 post-infection, degenerative changes were also observed by transmission electron microscopy. The histological changes were not associated with acid-fast bacteria or any fungal elements. The infection was systemic as C. jejuni was isolated from blood and all organ homogenates (lung, spleen, liver, and small and large intestines) at 24 h post-infection. Thereafter, the organism was recovered from the intestine only, thus indicating its predilection for this location. This characterization of pathology should contribute to a better understanding of the animal model and pathogenesis of C. jejuni infection.

Light and electron microscopy study of radioinduced injuries in rat cortex kidney vs. dose rate of irradiation

In order to describe radiation induced alterations of renal cell morphology, adult rats were whole-body exposed to 60-cobalt gamma rays at various doses (1, 2, or 4 Gy) and two dose rates (1 Gy/min or 1 Gy/h). 24 h or 48 h after irradiation, kidneys were take off and cortex fragments were fixed and embedded. Paraffin sections were used for light microscope study and TUNEL assay, and epon ones for conventional transmission electron microscope observations. Morphological changes in numerous tubules of irradiated samples were observed mainly in cells of proximal convoluted tubules (PCT) and not in distal ones (DCT), as nuclear and cytoplasm lesions. Epithelial cells containing round and small nucleus with homogenous condensed chromatin were detected in 1 Gy/min samples, which number increased with dose and post-irradiation time. Cells protuberances were seen in PCT lumen and identified as cellular proliferations. Damaged cells appeared TUNEL assay positives when compared to same serial histological cuts. Large tubular necrosis areas were seen only at 4 Gy dose, 1Gy/min dose rate and 48 h post-irradiation time that involved all tubules. Ultrastructural lesions were observed in cortex kidneys 24 h after irradiation at 2 and 4 Gy doses and 1 Gy/min dose rate, displaying all features of apoptotic process mainly in PCT isolated cells. Their appeared with dense cytoplasm that contains clusters of enlarged mitochondrias, numerous light vesicles and condensed heterogeneous chromatin within atypical shape nuclei. Others subcellular alterations of epithelial cells were seen only in 4 Gy-irradiated samples as brush border irregular microvilli. Some cellular fragments were detected inside the lumen of intact DCT containing recognizable organelles that we suppose to be apoptotic bodies of injured PCT cells. When compared to controls, glomeruli changes were induced at 1 Gy/h dose rate, 24 h after exposition for the two doses of irradiation as detachment of enlarged podocytes from basal membrane, hypertrophy of mesangial cells, damaged endothelial cells and vacuolization of the parietal leaflet.

Intoxicação experimental por Sida carpinifolia (Malvaceae) em bovinos

Descrevem-se os achados clínicos e patológicos da intoxicação experimental por Sida carpinifolia em bovinos. Para a reprodução experimental da doença, folhas verdes da planta foram coletadas semanalmente na região do Alto Vale do Itajaí e fornecidas in natura diariamente para cinco bovinos nas doses de 10 e 20g/kg por 120 dias, 40g/kg por 30 dias, e 30 e 40g/kg de peso animal por 150 dias. Um bovino morreu e os outros foram eutanasiados ao final do período de consumo da planta. Os principais sinais clínicos consistiam de andar em marcha, olhar atento e tremores de cabeça e foram de intensidade leve a acentuado conforme a dose de planta e tempo de consumo. A lesão histológica predominante caracterizava-se por vacuolização e tumefação de neurônios (principalmente os de Purkinje), das células acinares pancreáticas e células foliculares da tireóide. Ultra-estruturalmente verificou-se vacúolos, por vezes, contendo material finamente granular em neurônios, células acinares pancreáticas e células foliculares da tireóide. S. carpinifolia causa doença de depósito lisossomal em bovinos quando consumida por período prolongado, mesmo em pequenas doses.

Histological and ultrastructural studies of renal lesions in Babesia canis infected dogs treated with imidocarb

Histological and electron microscopic examinations of the kidneys of 8 dogs suffering from fatal, naturally acquired Babesia canis infection and nephropathy are presented. Seven animals were treated with imidocarb dipropionate on average 4.5 days prior to death. Severe anaemia was present only in 2 cases. Degenerative histological changes observed mostly in the proximal convoluted tubules included vacuolar-hydropic degeneration, necrosis and detachment of renal tubular epithelial (RTE) cells from the basement membrane. Necrotic debris occasionally formed acidophilic casts within the tubules. In some cases, necrosis of the whole tubule was observed. Haemoglobin casts in the tubules and haemoglobin droplets in RTE cells seldom appeared. No significant histological changes were seen in the glomeruli. Ultrastructural lesions in RTE cells included nuclear membrane hyperchromatosis, karyopyknosis, karyolysis, swelling or collapse of mitochondria with fragmentation of cristae and vacuolar-hydropic degeneration in the endoplasmic reticulum and microvilli. Nuclear oedema was also observed. Many RTE cells exhibiting necrosis collapsed. Vacuolar-hydropic degeneration and necrosis were also observed in the glomerular and interstitial capillary endothelium. The severe acute tubular necrosis described in this study is probably the result of hypoxic renal injury. Systemic hypotension leading to vasoconstriction in the kidneys might be the most important cause of renal hypoxia in B. canis infections, but anaemia may also contribute to inadequate oxygenation. Imidocarb should be applied with caution in patients with possible renal involvement until further data become available on its potential nephrotoxicity in dogs.

Candida albicans and filtrates interfere with human spermatozoal motility and alter the ultrastructure of spermatozoa: an in vitro study

The in vitro effects of Candida albicans and its filtrates on the motility and ultrastructure of human spermatozoa from healthy donors were studied. A significant reduction in sperm progressive motility and signs of membrane alteration, directly related to contact time were observed. Distinct adhesion of spermatozoa to C. albicans and agglutination were observed. Light and transmission electron microscopy examinations showed that spermatozoa attached to C. albicans mainly via the head. Multiple ultrastructural lesions were present, which were the possible morphological reasons for spermatozoan immobilization observed in the present study. It is concluded that C. albicans as well as its filtrates had an inhibitory effect on human sperm motility and impaired the ultrastructure of human spermatozoa, which could be associated with male infertility.

Equine laminitis: ultrastructural lesions detected 24–30 hours after induction with oligofructose

The pathology of equine laminitis has been well-documented 48 h after dosing with oligofructose when clinical lameness and lamellar disintegration is well advanced. Further analysis of the earliest lesions, by collecting lamellar samples at the first sign of foot lameness after oligofructose dosing is required in order to increase understanding of the disease. To investigate lamellar epidermal hemidesmosome damage and basement membrane dysadhesion by transmission electron microscopy (TEM). Eight clinically normal, mature Standardbred horses were divided randomly into 2 groups of 4. The treatment group were dosed with oligofructose (10 g/kg bwt) and subjected to euthanasia when shifting weight from one foot to other commenced and at the first sign of lameness during walking and turning. This occurred at 24 h in 3 horses and 30 h in one. The sham treatment control group were dosed with water and subjected to euthanasia after 48 h. Lamellar tissues of the front feet were harvested and processed for ultrastructural study using TEM. Examination by TEM showed excessive waviness of the basement membrane zone and pointed tips of some secondary epidermal lamellae, an ultrastructural lesion typical of laminitis. The average number of hemidesmosomes/microm of basement membrane was decreased and their distance from the centre of the lamina densa of the basement membrane was increased. Laminitis lesions are detectable 24 h after oligofructose administration. Hindgut events occurring in the first 24 h after dosing have begun the destruction of the hoof lamellar interface. Prevention and treatment strategies should precede lameness if they are to be efficacious.

Epidemiologia e sinais clínicos da conidiobolomicose em ovinos no Estado do Piauí

Foi realizado um estudo de ocorrência da conidiobolomicose ovina em 25 rebanhos no Estado do Piauí, de janeiro de 2002 a dezembro de 2004. A enfermidade acometeu apenas ovinos e ocorreu principalmente em abril-julho. A incidência média anual foi de 2,80% e a incidência semestral foi significativamente mais alta (P &lt;0,05) no primeiro semestre (2,10%), durante a época chuvosa, do que no segundo semestre (0,69%), durante a seca. A incidência entre rebanhos variou de 0,1-14,3% e a letalidade foi de 100%. Ao exame clínico, os animais apresentavam apatia, emagrecimento progressivo, secreção nasal serosa, mucosa e/ou hemorrágica, dificuldade respiratória, respiração ruidosa, febre e na maioria dos casos assimetria crânio-facial e exoftalmia. Alguns ovinos permaneciam com a cabeça baixa ou a pressionavam contra objetos. O curso clínico foi de 1-5 semanas. As lesões macroscópicas, microscópicas e ultrastructurais e a identificação do agente são descritas separadamente. Este é o primeiro registro de conidiobolomicose em ovinos no Brasil, enfermidade endêmica no Estado do Piauí, associada à alta pluviosidade (1000-1600mm anuais) e alta temperatura (19-36ºC).