Deposition Of Electron-dense Material Research Articles

Undifferentiated laryngeal carcinoma with hyaline bodies in a cat

BackgroundPrimary laryngeal neoplasms are rare in cats, with lymphoma and squamous cell carcinoma being the most commonly diagnosed tumour types. These tumours are usually highly aggressive, difficult to treat, and have a poor prognosis. Here an undifferentiated laryngeal carcinoma with hyaline bodies in a cat is reported.Case presentationA 13-year-old cat was presented for progressive respiratory signs. Diagnostic procedures revealed a partially obstructive laryngeal mass. Cytology was compatible with a poorly differentiated malignant tumour, with neoplastic cells frequently containing large intracytoplasmic hyaline bodies. After 1 month the patient was euthanised due to a worsening clinical condition and submitted for post-mortem examination, which confirmed the presence of two laryngeal masses. Histopathology confirmed the presence of an undifferentiated neoplasm with marked features of malignancy. Strong immunolabelling for pancytokeratin led to a diagnosis of undifferentiated carcinoma, however, histochemical and immunohistochemical investigations could not elucidate the origin of the large intracytoplasmic hyaline bodies observed in tumour cells, which appeared as non-membrane bound deposits of electron-dense material on transmission electron microscopy.ConclusionThis is the first report of primary undifferentiated laryngeal carcinoma in a cat. Our case confirms the clinical features and the short survival that have been reported in other studies describing feline laryngeal tumours. Moreover, for the first time in feline literature, we describe the presence of intracytoplasmic hyaline bodies in neoplastic cells that were compatible with the so-called hyaline granules reported in different human cancers and also in the dog.

Anatomical and ultrastructural alterations in Ceratopteris pteridoides under cadmium stress: A mechanism of cadmium tolerance

The present research is an appraisal of anatomical and ultrastructural alterations in aquatic fern, Ceratopteris pteridoides under cadmium (Cd) exposure. Plants were cultured hydroponically for 12 consecutive days in different Cd treatments: 10 µM L−1 (CDT1), 20 µM L−1 (CDT2), 40 µM L−1 (CDT3) and 60 µM L−1 (CDT4). Anatomical and ultrastructural changes of different vegetative tissues of C. pteridoides were investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cd stress significantly (P < 0.05) decreased water content percentage (WC%), relative growth rate (RGR) and root activity in C. pteridoides, especially at highest Cd concentration (treatment CDT4). Significant (P < 0.05) drop of stress tolerance indices (STI) was noticed in C. pteridoides under treatment CDT4. Anatomical study of the Cd-treated C. pteridoides showed stomatal closure of leaves, reduction of diameter in xylem tracheids of stem and root, and decrease of intercellular spaces. Furthermore, ultrastructural alterations of leaf, stem, and root cells were evident with a damaged membrane system of chloroplast and mitochondria, disorganization of chloroplastic components, accumulation of large starch grains and plastoglobules, and formation of multivesicular bodies. The deposition of electron-dense material in the cell wall of root cells can be regarded as an important tolerance mechanism of C. pteridoides under Cd stress. Fourier transform infrared (FTIR) spectroscopy analysis of Cd-treated C. pteridoides biomass illustrated Cd-binding interaction with O–H, N–H, C–H, C≡C, C˭O, P˭O, –C–OH and CS functional groups of different metabolites.

Symplasmic Isolation Contributes to Somatic Embryo Induction and Development in the Tree Fern Cyathea delgadii Sternb.

In this report, we describe studies on symplasmic communication and cellular rearrangement during direct somatic embryogenesis (SE) in the tree fern Cyathea delgadii. We analyzed changes in the symplasmic transport of low-molecular-weight fluorochromes, such as 8-hydroxypyrene-1,3,6-trisulfonic acid, trisodium salt (HPTS) and fluorescein (delivered to cells as fluorescein diacetate, FDA), within stipe explants and somatic embryos originating from single epidermal cells and developing during 16-d long culture. Induction of SE is preceded by a restriction in fluorochrome distribution between certain explant cells. Microscopic analysis showed a series of cellular changes like a decrease in vacuole size, increase in vacuole numbers, and increased density of cytoplasm and deposition of electron-dense material in cell walls that may be related with embryogenic transition. In somatic embryos, the limited symplasmic communication between cells was observed first in linear tri-cellular embryos. Further development of the fern embryo was associated with the formation of symplasmic domains corresponding to the four segments of the plant body. Using symplasmic tracers, we provided evidence that the changes in plasmodesmata permeability are corelated with somatic-to-embryogenic transition and somatic embryo development.

Exfoliation Fibrils within the Basement Membrane of Anterior Lens Capsule: A Transmission Electron Microscopy Study

ABSTRACTPurpose: The aim of the present study was to demonstrate novel findings recognized within the basement membrane of the anterior lens capsules (ALCs) in exfoliation syndrome, in a transmission electron microscopy (TEM) study.Materials and methods: Twenty-one patients with age-related cataract were included in the study. Eleven out of them suffered from exfoliation syndrome (XFS). Anterior lens capsules were obtained from patients during phacoemulsification, applying continuous curvilinear capsulorhexis and then were examined by transmission electron microscope.Results: Six out of 11 examined basement membranes with XFS had a granular appearance with dotted deposits of electron-dense material. Fibrils were clearly detected, longitudinally, within the basement membrane, usually located in the outer quarter of the basement membrane, towards the anterior chamber.Conclusion: New data about the exfoliation material and its location within the basement membrane of the anterior lens capsules of XFS patients are presented. These findings constitute new evidence for XFS’s histopathogenesis and might help clarify the lenticular exfoliation material’s (XFM) mechanisms of origin.

Anatomical and ultrastructural responses of Hordeum sativum to the soil spiked by copper.

Effects of Cu toxicity from contaminated soil were analysed in spring barley (Hordeum sativum distichum), a widely cultivated species in South Russia. In this study, H. sativum was planted outdoors in one of the most fertile soils-Haplic Chernozem spiked with high concentration of Cu and examined between the boot and head emergence phase of growth. Copper toxicity was observed to cause slow ontogenetic development of plants, changing their morphometric parameters (shape, size, colour). To the best of our knowledge, the ultrastructural changes in roots, stems and leaves of H. sativum induced by excess Cu were fully characterized for the first time using transmission electron microscopy. The plant roots were the most effected, showing degradation of the epidermis, reduced number of parenchyma cells, as well as a significant decrease in the diameter of the stele and a disruption and modification to its cell structure. The comparative analysis of the ultrastructure of control plants and plants exposed to the toxic effects of Cu has made it possible to reveal significant disruption of the integrity of the cell wall and cytoplasmic membranes in the root with deposition of electron-dense material. The changes in the ultrastructure of the main cytoplasmic organelles-endoplasmic reticulum, mitochondria, chloroplasts and peroxisomes-in the stem and leaves were found. The cellular Cu deposition, anatomical and ultrastructural modifications could mainly account for the primary impact points of metal toxicity. Therefore, this work extends the available knowledge of the mechanisms of the Cu effect tolerance of barley.

Transmission electron microscopy study of undescribed material at the anterior lens capsule in exfoliation syndrome.

In the present study, we aimed to examine the anterior lens capsule using transmission electron microscopy (TEM) and compare the findings in patients with and without exfoliation syndrome (XFS). Eighteen patients with senile cataract, including 10 with XFS, were included. Anterior capsule specimens were obtained from patients during phacoemulsification through continuous curvilinear capsulorrhexis, and were examined via TEM. In the XFS group, in addition to the typical fibrillar material above the basement membrane of the lens capsule, another unknown, microgranular, electron-dense, unbound material was observed beneath the lens epithelium. Larger formations appeared to detach from the surface of the epithelial cells, and oval or crescent-shaped structures of an electron-denser material were less commonly observed on the apical side of the epithelium. Membranous structures were occasionally attached to epithelial cells that often exhibited thicker or ruptured cell membranes on their apical-free side, along with deposits of electron-dense material. Degenerative lesions of various severities were observed at the epithelium in both groups. The anterior lens capsule epithelium in patients with XFS exhibits a highly irregular and rough margin on its free side, with unbound material over its membrane, which probably contributes to loose contact with the underlying lens and leads to different clinical behaviors in XFS eyes during cataract surgery.

Structural and Biochemical Changes in Salicylic-Acid-Treated Date Palm Roots Challenged with Fusarium oxysporum f. sp. albedinis.

Histochemical and ultrastructural analyses were carried out to assess structural and biochemical changes in date palm roots pretreated with salicylic acid (SA) then inoculated with Fusarium oxysporum f. sp. albedinis (Foa). Flavonoids, induced proteins, and peroxidase activity were revealed in root tissues of SA-treated plants after challenge by Foa. These reactions were closely associated with plant resistance to Foa. Host reactions induced after inoculation of SA-treated plants with Foa included the plugging of intercellular spaces, the deposition of electron-dense materials at the sites of pathogen penetration, and several damages to fungal cells. On the other hand, untreated inoculated plants showed marked cell wall degradation and total cytoplasm disorganization, indicating the protective effects provided by salicylic acid in treated plants.

PH-Dependent Toxicity of High Aspect Ratio ZnO Nanowires in Macrophages Due to Intracellular Dissolution

High-aspect ratio ZnO nanowires have become one of the most promising products in the nanosciences within the past few years with a multitude of applications at the interface of optics and electronics. The interaction of zinc with cells and organisms is complex, with both deficiency and excess causing severe effects. The emerging significance of zinc for many cellular processes makes it imperative to investigate the biological safety of ZnO nanowires in order to guarantee their safe economic exploitation. In this study, ZnO nanowires were found to be toxic to human monocyte macrophages (HMMs) at similar concentrations as ZnCl(2). Confocal microscopy on live cells confirmed a rise in intracellular Zn(2+) concentrations prior to cell death. In vitro, ZnO nanowires dissolved very rapidly in a simulated body fluid of lysosomal pH, whereas they were comparatively stable at extracellular pH. Bright-field transmission electron microscopy (TEM) showed a rapid macrophage uptake of ZnO nanowire aggregates by phagocytosis. Nanowire dissolution occurred within membrane-bound compartments, triggered by the acidic pH of the lysosomes. ZnO nanowire dissolution was confirmed by scanning electron microscopy/energy-dispersive X-ray spectrometry. Deposition of electron-dense material throughout the ZnO nanowire structures observed by TEM could indicate adsorption of cellular components onto the wires or localized zinc-induced protein precipitation. Our study demonstrates that ZnO nanowire toxicity in HMMs is due to pH-triggered, intracellular release of ionic Zn(2+) rather than the high-aspect nature of the wires. Cell death had features of necrosis as well as apoptosis, with mitochondria displaying severe structural changes. The implications of these findings for the application of ZnO nanowires are discussed.

Amiodarone-induced liver cirrhosis and parkinsonism: a case report

Amiodarone-induced hepatotoxicity consists of mild liver test abnormalities and rare cases of acute hepatitis and chronic hepatic lesions, and histologically resembles the whole spectrum of alcoholic liver disease, i.e., non-alcoholic steatohepatitis. Amiodarone-induced neurotoxicity, including tremor, ataxia and peripheral neuropathy, is known, and some cases of parkinsonism following amiodarone use have also been reported. To study the pathology of amiodarone-associated parkinsonism. Light and electromicroscopic examinations of a patient with liver cirrhosis and amiodarone-induced parkinsonism. On postmortem examination, the liver showed micronodular cirrhosis. Striking steatosis and frequent Mallory bodies were present on light microscopy. There were lysosomal inclusion bodies on electron microscopy. From these findings, amiodarone-induced liver cirrhosis was diagnosed. Brain atrophy and infarcts were not observed, and pigmentation in the substantia nigra was preserved. Histologically, there was a slightly lesser degree of neuronal loss with astrocytosis in the substantia nigra, locus ceruleus, and dorsal vagal nucleus. Lewy bodies were not found. In the cerebral white matter and basal ganglia, Alzheimer Type II astrocytes, which are abundant in hepatic encephalopathy, had deposition of electron-dense materials within the lysosomes and mitochondrial matrices. The materials were compatible with the accelerated amiodarone. This is the first case in which the accumulation of amiodarone in the brain was morphologically observed. Amiodarone accumulation in the brain may play a role in neurotoxicity inducing parkinsonism.

Neuronal and Glial Alterations Due to Focal Cortical Hypoxia Induced by Direct Cobalt Chloride (CoCl2) Brain Injection

Ischemic brain injury is a dynamic process that involves oxidative stress, inflammation, and cell death, as well as activation of endogenous adaptive and regenerative mechanisms depending on activation of transcription factors such as hypoxia inducible factor 1-alpha (HIF-1alpha). Because CoCl2 activates HIF-1alpha, we described a new focal-hypoxia model by direct intracerebral CoCl2 injection. Adult male Wistar rats were intracerebrally injected with CoCl2 (2 microl-50 mM), in frontoparietal cortex of right hemisphere, and saline (2 microl) in the contralateral hemisphere. In slides of fixed brains at 1, 6, 9, 24 h or 5 day after treatment, TTC, histochemistry (toluidine blue, Hoescht-33342, TUNEL), immunostaining (HIF-1alpha, GFAP), Lycopersicon esculentum lectin staining, and electron microscopy (EM) were performed. Immediately after 1 h post CoCl2 injection, HIF-1alpha stabilization and neuronal nuclear shrinkage and cromathin condensation were observed by immunostaining and EM, respectively. Neuronal apoptotic nuclear morphology and GFAP immunoreactivity and lectin maximal reactivity were detected during 6-9 h. Ultrastructural alterations of morphology included edematous perinuclear cytoplasm, organelles and endoplasmic reticulum (RE) enlargement, mitochondrial swelling with increased matrix density, and deposits of electron-dense material. Neurons showed particular nuclear indentations. Astrocytes and oligodendrocytes presented alterations in both nuclei and RE with dilated lumen and altered mitochondrias, and all these ultrastructural changes became detectable at day 5. CoCl2 cortical injection mimics focal brain ischemia, inducing neuronal death and glial activation. This model brings the opportunity to develop focal ischemia in selected brain areas to study their functional consequences and potential pharmacological therapies for in vivo models of stroke.

Morphology and taxonomy of the microsporidium Liebermannia covasacrae n. sp. from the grasshopper Covasacris pallidinota (Orthoptera, Acrididae)

During a survey for grasshopper pathogens in Argentina in 2005–2006, individual Covasacris pallidinota from halophylous grasslands in Laprida, Buenos Aires province were found to be infected with a microsporidium. Infection was restricted to the salivary gland epithelial cells. The microsporidium produced ovocylindrical spores averaging 2.6 ± 0.28 × 1.4 ± 0.12 μm (range 2.2–3.4 × 1.1–1.7 μm), which resembled in size and shape the spores of Liebermannia patagonica and L. dichroplusae, two recently described species that also parasitize Argentine grasshoppers. The life cycle of the microsporidium included the formation of polynucleate, diplokaryotic, moniliform, merogonial plasmodia wrapped in flattened cisterns of the host endoplasmic reticulum (ER). Plasmodia divided to produce diplokaryotic cells. The latter underwent elongation, dissociation of diplokarya counterparts, vacuolization, dismantling of the host ER envelope, and deposition of electron-dense material outside the plasma membrane. The resultant binucleate sporogonial plasmodia divided into two uninucleate sporoblasts, which eventually transformed into spores. Uninucleate spores contained a lamellar polaroplast, embraced by an elongated polar sac, anchoring disc, 3–5 polar filament coils, and a cluster of anastomizing tubules (sporoblast trans-Golgi, posterosome) at the posterior end. Sequence similarity of the SSU rDNA of the newly discovered microsporidium (Genbank accession no. EU709818) to L. patagonica and L. dichroplusae was 99% and 97%, respectively, suggesting that the three species belong to one genus. All three species fell into one clade in SSU rDNA-based phylogenetic trees produced by neighbor joining, maximum parsimony, and maximum likelihood analyses with 100% statistical support. We assign the name Liebermannia covasacrae to this microsporidium. It can be easily differentiated from both congeners by host species, tissue tropism, type of sporogony, and several features of morphology. Comparison of the three Liebermannia spp. demonstrates that the nuclear phase (dikaryotic versus monokaryotic spores) and type of sporogony (polysporous versus disporous) may vary in closely related species.

Ultrastructural changes of radish leaf exposed to cadmium

Cadmium (Cd 2+) is one of the most toxic heavy metal pollutants in nature. Mesophyll cells from the leaf of radish seedlings exposed to 0.25 and 1.0 mM of CdCl 2 during 24 h exhibited structural changes of chloroplasts, mitochondria and nuclei when compared to non-treated control plants. Chloroplasts from Cd 2+-exposed samples exhibited changes in the organelle shape, an increase in the stroma volume and a deposition of electron-dense material in the double membrane. The changes in the chloroplast membranes were not very drastic, however and reorganization of the thylakoids and stroma was observed. In contrast, the breakdown of the nuclear envelope of the plant cells treated with Cd 2+ was very clear. The accumulation of electron-dense granules was also observed in mitochondria. No alterations were observed in the vacuoles of radish seedlings grown at different Cd 2+ concentrations for the periods tested.

Functional cerebrovascular abnormalities in CADASIL

CADASIL is a hereditary small vessel disease related to NOTCH3 mutations. Main vascular characteristics include: vascular smooth muscle cell degeneration, deposition of the extracellular domain of the Notch3 receptor, and deposition of electron dense material within the arterial wall. SPECT, PET, and perfusion MRI studies have demonstrated a reduction in cerebral blood flow (CBF) and cerebral blood volume (CBV) particularly within white matter regions that are hyperintense on T2-weighed images. Consistent with these findings, doppler sonography reveals diminished mean flow velocities in the MCA. These changes might in part relate to a rarefication of the microvascular tree. Several studies found an impaired cerebrovascular reactivity. Thus, for example, the vasodilatory response to C02 and acetazolamide was found to be reduced whereas the vasodilatory response to L-Arginine was significantly enhanced in cerebral blood vessels. Again, altered cerebrovascular reactivity was most pronounced within WML. Treatment with statins over two months had no significant effect on cerebrovascular CO2 reactivity and the response to L-Arginine. Isolated peripheral blood vessels from CADASIL patients show an enhanced vasoconstrictor response to angiotensin II and reduced tachyphylaxis in the presence of a normal vasodilatory response to acetylcholine and bradykinin. Both structural and functional vascular alterations might contribute to the occurence of subcortical lesions. Yet, the exact mechanisms underlying such lesions in CADASIL are still unknown.

IgA deficiency and membranous glomerulonephritis presenting as nephrotic syndrome

Selective IgA deficiency associated with glomerulonephritis is rare and no previous reports in childhood have been made of the association of IgA deficiency and membranous glomerulonephritis (MGN). We report a 5-year-old boy with selective IgA deficiency and MGN. He presented with nephrotic syndrome. Percutaneous renal needle biopsy showed diffuse global thickening on light microscopy and heavy IgG and moderate C3 deposits were found on immunofluorescence. Electron microscopy detected extensive global subepithelial deposition of electron-dense material with frequent intramembranous extension and spike formation. The pathological diagnosis was diffuse MGN stage 1. Oral prednisolone (1 mg kg(-1) day(-1)), angiotensin-converting enzyme inhibitors (ACEI), and angiotensin II receptor blocker (ARB) were given resulting in reduction of proteinuria. The prednisolone dose was gradually tapered and discontinued after 2 months. At present the patient has been in complete remission for 10 months despite the discontinuance of prednisolone. In conclusion, our treatment with corticosteroid, ACEI and ARB reduced proteinuria and was effective for our case with selective IgA deficiency and MGN.

Subcellular localization of chromium and nickel in root cells of Allium cepa by EELS and ESI.

The ultrastructural investigation of the root cells of Allium cepa L. exposed to two different concentrations of chromium + nickel (Cr+Ni) (10 micromol/L and 100 micromol/L) revealed that toxic symptoms were induced by increasing heavy metal concentration and treatment time. Several significant ultrastructural changes were caused by 100 micromol/L Cr+Ni - deposition of electron dense material in cell walls; larger vacuolar precipitates surrounded by membranes inside vacuoles; increment of disintegrated organelles and high vacuolization in cytoplasm. The localization of the precipitates in which the metal ions were detected by electron energy loss spectroscopy (EELS) and electron spectroscopic imaging (ESI) was investigated. Chromium and nickel were localized in the electron dense precipitates of the root cells exposed to only 100 micromol/L Cr+Ni. None were found in the root cells exposed to 10 micromol/L Cr+Ni. Higher amounts of Cr+Ni were mainly accumulated in the cell walls and vacuoles of the fourth or fifth cortical layer.

Subcellular localization of Cd in the root cells of Allium sativum by electron energy loss spectroscopy.

The ultrastructural investigation of the root cells of Allium sativum L. exposed to three different concentrations of Cd (100 mM, 1 mM and 10 mM) for 9 days was carried out. The results showed that Cd induced several significant ultrastructural changes high vacuolization in cytoplasm, deposition of electron-dense material in vacuoles and nucleoli and increment of disintegrated organelles. Data from electron energy loss spectroscopy (EELS) revealed that Cd was localized in the electron-dense precipitates in the root cells treated with 10 mM Cd. High amounts of Cd were mainly accumulated in the vacuoles and nucleoli of cortical cells in differentiating and mature root tissues. The mechanisms of detoxification and tolerance of Cd are briefly explained.

Croissance, activité peroxydasique et modifications ultrastructurales induites par le cadmium dans la racine de tomate

Accumulation of Cd in the organs of young tomato plants (Lycopersicon esculentum var. Ibiza F1), as well as its effects on growth, peroxidasic activity, and root ultrastructure were evaluated. Plants previously cultivated in a basic nutrient solution and then treated for 10 days with different concentrations of CdCl2(0, 5, 10, 20, 50, 100 μM) accumulated high quantities of cadmium in their root tissues and showed reduced growth. Increased peroxidasic activity observed at this level reflects a state of oxidative stress induced by cadmium. An ultrastructural study of the root apex showed a strong vacuolization in the meristematic cells as well as deposition of electron-dense material in vacuoles and plastids. On either side of the cell wall, a medullated-like and (or) vesicular membrane system developed over a significant periplasmic space. Results suggest an endocellular metal accumulation leading to a disorganization of membrane systems, probably related to the onset of an oxidative state of stress.Key words: cadmium, tomato, peroxidases, ultrastructure, root.[Translated by editorial staff]

Ultrastructural changes of neuronal mitochondria after transient and permanent cerebral ischemia.

Mitochondrial swelling is one of the most striking and initial ultrastructural changes after acute brain ischemia. The purpose of the present study was to examine the role of reperfusion of the cerebral cortex after transient focal cerebral ischemia on neuronal mitochondrial damage. Male Sprague-Dawley rats (n=16) were subjected to either temporary or permanent occlusion of the middle cerebral artery and bilateral carotid arteries. Three experimental conditions were compared: group I, permanent ischemia (3, 5, and 24 hours); group II, transient ischemia (2, 24 hours of reperfusion); and sham surgery. Anesthetized rats were killed by cardiac perfusion, and brain tissue was removed ipsilaterally and contralaterally from the ischemic core section of the frontoparietal cortex. Fixed tissue was prepared for electron microscopic examination, and electron microscopic thin sections of random neurons were photographed. Perinuclear neuronal mitochondria were analyzed in a blinded manner for qualitative ultrastructural changes (compared with sham control) by 2 independent investigators using an objective grading system. Cortical neuronal mitochondria exposed to severe ischemic/reperfusion conditions demonstrated dramatic signs of injury in the form of condensation, increased matrix density, and deposits of electron-dense material followed by disintegration by 24 hours. In contrast, mitochondria exposed to an equivalent time of permanent ischemia demonstrated increasing loss of matrix density with pronounced swelling followed by retention of their shape by 24 hours. Neuronal mitochondria undergoing transient versus permanent ischemia exhibit significantly different patterns of injury. Structural damage to neuronal mitochondria of the neocortex occurs more acutely and to a greater extent during the reperfusion phase in comparison to ischemic conditions alone. Further research is in progress to delineate the role of oxygen free radical production in the observed mitochondrial damage during postischemic reoxygenation.

Analysis of Glomerulosclerosis and Atherosclerosis in Lecithin Cholesterol Acyltransferase-deficient Mice

To evaluate the biochemical and molecular mechanisms leading to glomerulosclerosis and the variable development of atherosclerosis in patients with familial lecithin cholesterol acyl transferase (LCAT) deficiency, we generated LCAT knockout (KO) mice and cross-bred them with apolipoprotein (apo) E KO, low density lipoprotein receptor (LDLr) KO, and cholesteryl ester transfer protein transgenic mice. LCAT-KO mice had normochromic normocytic anemia with increased reticulocyte and target cell counts as well as decreased red blood cell osmotic fragility. A subset of LCAT-KO mice accumulated lipoprotein X and developed proteinuria and glomerulosclerosis characterized by mesangial cell proliferation, sclerosis, lipid accumulation, and deposition of electron dense material throughout the glomeruli. LCAT deficiency reduced the plasma high density lipoprotein (HDL) cholesterol (-70 to -94%) and non-HDL cholesterol (-48 to -85%) levels in control, apoE-KO, LDLr-KO, and cholesteryl ester transfer protein-Tg mice. Transcriptome and Western blot analysis demonstrated up-regulation of hepatic LDLr and apoE expression in LCAT-KO mice. Despite decreased HDL, aortic atherosclerosis was significantly reduced (-35% to -99%) in all mouse models with LCAT deficiency. Our studies indicate (i) that the plasma levels of apoB containing lipoproteins rather than HDL may determine the atherogenic risk of patients with hypoalphalipoproteinemia due to LCAT deficiency and (ii) a potential etiological role for lipoproteins X in the development of glomerulosclerosis in LCAT deficiency. The availability of LCAT-KO mice characterized by lipid, hematologic, and renal abnormalities similar to familial LCAT deficiency patients will permit future evaluation of LCAT gene transfer as a possible treatment for glomerulosclerosis in LCAT-deficient states.

Reproductive impairment of sea urchin upon chronic exposure to cadmium. Part II: Effects on sperm development

Chronic pollution may impair the reproductive success of adult organisms through a decrease in the quality of gametes. Our parallel study on gamete quality, showed that male sea urchins were more sensitive than the females towards cadmium pollution. The effects of chronic exposure to 0.01 and 1 ppm Cd 2+ on sperm development of the sea urchin Anthocidaris crassispina were studied. Despite the fact that no significant change in gonad index was observed when sea urchins were exposed to both levels of Cd 2+ for 4 weeks, deposition of electron-dense materials was conspicuous at the wall and intracellular space of male gonads. Apparent cytological alterations were observed in sperm cells, including changes in morphology of nuage in spermatogonia. The discrete, granular bodies of nuage were replaced by a large electron-dense body. Spermatozoa with short, incomplete ‘broken’ tails (scanning electron microscope observation) or tails of spermatids/spermatozoa with extraordinary electron-density (transmission electron microscope observation) were more abundant in gonads exposed to both levels of Cd 2+. Mitochondrial cristae deformation was observed for sperm cells at all stages of development. Sperm plasma membrane also became more convoluted but acrosome remained intact. The observed cytological distortion of sperm tails and mitochondria/midpiece could help to explain the decline in motility as well as poor perseverance in sperm produced by sea urchins exposed to cadmium observed in our earlier study.