Ultrastructural Pathology Research Articles

Occurrence of hyaline droplets in renal biopsy specimens: an ultrastructural study

Hyaline droplets are apical cytoplasmic vesicles containing an accumulation of electron-dense amorphous materials surrounded by a unit membrane. Hyaline droplets may originate from apical vesicles after conversion to osmotic vesicles and loss of internally lined glycocalyx. They are found in the proximal tubular epithelium in biopsies from patients with renal diseases; however, their biological importance is not well understood. We reviewed ultrastructural pathology records of 140 renal biopsy patients to determine the occurrence and relevance of hyaline droplets. Of the cases, 14 (10%) showed the presence of hyaline droplets in proximal tubular epithelium. The distribution of cases were 8 of the 19 (42%) with minimal change nephritic syndrome, 2 of the 37 (5%) with IgA nephropathy, 2 of the 4 (50%) with membranous glomerulonephropathy, 1 of the 4 (25%) with tubulointerstitial nephritis, and 1 of the 1 (100%) with acute renal failure. The droplets were frequently found in male patients (86%), never in children, and were mostly associated with tubular necrosis (8 of 14 cases; 56%). Many hyaline droplets were observed in the cytoplasm of necrotic proximal tubular epithelial cells, and even when tubular necrosis was not evident, the proximal tubular epithelial cells containing hyaline droplets showed degenerated microvilli and decreased basal interdigitations. These results suggest that hyaline droplets could be one marker of renal tubular necrosis and a sign of functional disorder of protein reabsorption by degenerating proximal tubular epithelium.

Textbook–Atlas of Intestinal Infection in AIDS

Gastrointestinal tract infections are prominent in patients with AIDS. Infections may be caused by a variety of bacterial, fungal, viral, protozoal, and helminthic pathogens, and affect persons in both developing and industrialized countries. The problems are especially acute in resource-limited countries where little or no access to highly active antiretroviral therapy exists; the impact of illnesses associated with HIV is most pronounced in these countries. Daniele Dionisio, an authority in parasitology, has assembled a new treatise, Textbook–Atlas of Intestinal Infections in AIDS, that directly addresses this topic. In 489 pages, the work includes much background, including a fascinating chapter by Esther Diane on the history of the discovery of intestinal parasites. The work and illustrations of parasitic life cycles by Dionisio and colleagues are illuminating for all students of infectious diseases. Much of the book addresses particular agents and the diseases they cause. A particular strength is the numerous illustrations. Although varying in quality, they represent an enormous compendium of information about these common problems. The figures on microscopic and ultra-structural pathology are particularly strong. This volume should be considered as a background text for the pathologist, gastroenterologist, or infectious disease specialist who concentrates on HIV infections. The illustrations and references provide readers access to materials not easily obtained. The sections on clinical management of particular conditions are relatively sparse, and healthcare workers with patients with active problems should consult with a more comprehensive text. In total, this textbook-atlas is a useful addition in the battle against HIV infections and its complications. The editor and multinational group of authors are to be congratulated on their scholarly work.

Applications of Immunogold Labeling in Ultrastructural Pathology

This review provides an update on the use of postembedding immunogold labeling, preferentially of the protein A–gold technique, for electron microscopic research in diseased states. In the first part, some helpful antigen recovery techniques for use of immunogold labeling of ultrathin sections prepared from routinely aldehyde (and osmium tetroxide) fixed and conventionally epoxy resin-embedded tissue are cited. In the second part, selected applications for studies of tumor cell surface conjugates, such as polysialic acid in Wilms tumor, proinsulin–insulin conversion in human insulinoma, and the importance of pre-Golgi intermediates for retention of a misfolded polypeptide hormone in a protein misfolding disease, are discussed.

The Spectrum of Pediatric Tumors in Infancy, Childhood, and Adolescence: A Comprehensive Review with Emphasis on Special Techniques in Diagnosis

The spectrum of pediatric tumors varies considerably, from those derived from blastemal cells in various organ systems to proliferations of soft tissue supporting cells to hamartomatous processes that mimic malignant tumors. Small round cell tumors are often undifferentiated or poorly differentiated, making it difficult sometimes to provide a definitive diagnosis. Both benign and malignant tumors require a coordinated method for diagnosis, and need a comprehensive evaluation to provide the most appropriate diagnosis for designing therapy and predicting prognosis. Pediatric tumors require the integration of routine histopathologic examination with histochemical, immunocytochemical, ultrastructural, cytogenetic, and diagnostic molecular pathology techniques. This review provides updated guidelines with respect to the application of these special techniques in this rapidly evolving diagnostic arena.

Life cycle stages of the amphibian chytrid Batrachochytrium dendrobatidis

An overview of the morphology and life cycle of Batrachochytrium dendrobatidis, the cause of chytridiomycosis of amphibians, is presented. We used a range of methods to examine stages of the life cycle in culture and in frog skin, and to assess ultrastructural pathology in the skin of 2 frogs. Methods included light microscopy, transmission electron microscopy with conventional methods as well as high pressure freezing and freeze substitution, and scanning electron microscopy with critical point drying as well as examination of bulk-frozen and freeze-fractured material. Although chytridiomycosis is an emerging disease, B. dendrobatidis has adaptations that suggest it has long been evolved to live within cells in the dynamic tissue of the stratified epidermis. Sporangia developed at a rate that coincided with the maturation of the cell, and fungal discharge tubes usually opened onto the distal surface of epidermal cells of the stratum corneum. A zone of condensed, fibrillar, host cytoplasm surrounded some sporangia. Hyperkeratosis may be due to (1) a hyperplastic response that leads to an increased turnover of epidermal cells, and (2) premature keratinization and death of infected cells.

Lesões perinatais em bovinos na intoxicação experimental por Ateleia glazioviana (Leg.Papilionoideae)

Folhas de Ateleia glazioviana Baill., dessecadas em estufa a 100ºC por 16 a 20 horas, foram administradas a sete vacas sem raça definida. Duas vacas receberam 9 g/kg da planta seca aos 4 meses de gestação em dose única. Três vacas no 8º mês de gestação, receberam doses diárias de 1 a 2 g/kg da planta seca, perfazendo totais de 10, 21 e 28 g/kg. Duas outras, também no 8º mês de gestação, receberam a planta seca em dose única 15,5 e 18 g/kg. Duas vacas, no 4º mês de gestação, receberam 35 g/kg da planta verde, em dose única. A vaca que recebeu 21 g/kg da planta seca foi a única a apresentar sinais clínicos de intoxicação e o bezerro nasceu morto. As demais vacas não apresentaram sinais clínicos. Os bezerros das vacas que receberam a planta seca nas doses de 9, 15,5 e 28 g/kg, apresentaram sinais clínicos de debilidade, dificuldade de manter-se em pé e mamar e foram sacrificados. Macroscopicamente, no bezerro que nasceu morto, foram observados áreas esbranquiçadas e espessamento da parede do ventrículo cardíaco direito. Os demais bezerros que nasceram fracos foram sacrificados e não apresentaram lesões macroscópicas, com exceção do bezerro da vaca que recebeu a planta seca, na dose total de 28g/kg, que apresentou, também, espessamento da parede do ventrículo direito. As alterações histológicas do bezerro que nasceu morto e dos que foram sacrificados por apresentarem sinais clínicos de debilidade caracterizaram-se por tumefação e vacuolização de feixes de fibras musculares e proliferação de tecido fibroso entre os cardiomiócitos. Essas lesões são semelhantes às observadas em casos espontâneos da intoxicação. Os cardiomiócitos mostraram reação PAS positiva no sarcoplasma, mais acentuada do que no animal controle. No bezerro que nasceu morto foi observado, também, espongiose discreta na substância branca do cerebelo, colículos rostrais e tálamo. O estudo ultra-estrutural do coração revelou fibras cardíacas com acúmulos de gliocogênio, situados entre feixes de miofibrilas, os quais mostravam perda de miofilamentos e desaparecimento de sarcômeros inteiros. No animal controle a presença de glicogênio foi substancialmente menor do que nos animais intoxicados.

A Comprehensive Study of Easter Lily Poisoning in Cats

This study was conducted with 3 objectives in mind: first, to identify the toxic fraction (aqueous or organic) in leaves and flowers; second, to identify diagnostic marker(s) of toxicosis in cats; and, third, to evaluate the morphologic effects of intoxication. The study was conducted in 2 phases. Phase 1 was to identify which extract, organic or aqueous, was nephrotoxic and also to determine the appropriate dose for use in the phase 2 studies. Results indicated that only the aqueous extracts of leaves and flowers were nephrotoxic and pancreotoxic. To identify the proximate toxic compound, cats in the phase 2 study were orally exposed to subfractions of the aqueous flower extract, 1 subfraction per cat. Results confirmed vomiting, depression, polyuria, polydipsia, azotemia, glucosuria, proteinuria, and isosthenuria as toxic effects of the Easter lily plant. Another significant finding in serum was elevated creatinine kinase. Significant histologic kidney changes included acute necrosis of proximal convoluted tubules and degeneration of pancreatic acinar cells. Renal ultrastructural changes included swollen mitochondria, megamitochondria, edema, and lipidosis. Subfraction IIa3 of the aqueous floral extract contained most of the toxic compound(s). These studies reproduced the clinical disease, identified the most toxic fraction of the Easter lily, and helped characterize the clinical pathology, histopathology, and ultrastructural pathology associated with the disease.

Reply to: Prophylactic use of deferiprone (L1) and MRI T2* or T2 for preventing heart disease in thalassaemia

and risks of deferiprone in iron overload in thalassaemia and other conditions. Comparison of epidemiological and therapeutic aspects with deferoxamine. Drug Safety, 26, 553–584. Kyriacou, K., Michaelides, Y., Senkus, R., Simamonian, K., Pavlides, N., Antoniades, L. & Zambartas, C. (2000) Ultrastructural pathology of the heart in patients with b-thalassaemia major. Ultastructural Pathology, 24, 75–81. Peng, C.T., Chow, K.C., Chen, J.H., Chiang, Y.P., Lin, T.Y. & Tsai, C.H. (2003) Safety monitoring of cardiac and hepatic systems in b-thalassemia patients with chelating treatment in Taiwan. European Journal of Haematology, 70, 392–397.

Ultrastructural pathology of prion diseases revisited: brain biopsy studies

We report here a detailed ultrastructural comparison of brain biopsies from 13 cases of Creutzfeldt-Jakob disease (CJD) and from one case of fatal familial insomnia (FFI). The latter disease has not heretofore benefited from ultrastructural study. In particular, we searched for tubulovesicular structures (TVS), 35-nm particles regarded as the only disease-specific structures at the level of thin-section electron microscopy. Our material consisted of brain biopsies obtained by open surgery from one FFI case from a new French family, one case of variant CJD (vCJD), nine cases of sporadic CJD (sCJD), two cases of iatrogenic (human growth hormone) CJD and one case of hereditary CJD (Val203Iso). The ultrastructural picture of the cerebral cortex of the FFI patient was virtually indistinguishable from that of CJD. TVS were found, albeit only after prolonged search. Typical spongiform change was observed, consisting of intracellular membrane-bound vacuoles containing secondary chambers (vacuoles within vacuoles) and amorphous material. Neuronal degeneration was widespread: some processes contained degenerating mitochondria and lysosomal electron-dense bodies and these met the criteria for neuroaxonal dystrophy. Other processes contained branching cisterns; still others were filled with electron-dense masses and amorphous vesicles. The overall ultrastructural appearance of variant CJD was similar to that of FFI cerebral cortex, except for a much higher number of cellular processes containing TVS. We detected TVS in the majority of sCJD cases that, in addition to typical spongiform change and robust astrocytic reaction, showed widespread neuritic and synaptic degeneration and autophagic vacuoles. We conclude that TVS are readily found in FFI, vCJD and sCJD and that widespread neuritic degeneration is a part of ultrastructural pathology in prion diseases.

Autophagy is a part of ultrastructural synaptic pathology in Creutzfeldt–Jakob disease: a brain biopsy study

Ultrastructural correlates of synaptic and dendritic spines loss have never been studied in detail in human transmissible spongiform encephalopathies (TSEs)—Creutzfeldt–Jakob disease (CJD), Gerstmann-Sträussler-Scheinker (GSS) disease and fatal familial insomnia (FFI). In this paper, we describe synaptic alterations as found in brain biopsies from Creutzfeldt–Jakob disease and fatal familial insomnia patients. Our material consisted of brain biopsies obtained by open surgery from one FFI case, one case of variant Creutzfeldt–Jakob disease (vCJD), seven cases of sporadic Creutzfeldt–Jakob disease (sCJD) and one case of iatrogenic (human growth hormone) Creutzfeldt–Jakob disease (iCJD). For electron microscopy, approximately 2 mm 3 samples were immersion fixed in 2.5% glutaraldehyde for less than 24 h, embedded in Epon and routinely processed. Grids were examined and photographed in a transmission electron microscope. The synaptic alterations were found constantly; in practically every brain biopsy they were frequent. The accumulation of different subcellular organelles (neuroaxonal dystrophy), dark synapses and branching cisterns were the most frequent findings while concentric arrays of membranes were only rarely found. Autophagic vacuoles are formed in many synapses in all categories of human transmissible encephalopathies. We conclude that synaptic autophagy contributes to overall synaptic loss in brains affected in prion diseases.

Effect of microwave irradiation on neurocyte mitochondrial ultrastructure and mtTFA mRNA expression in rats cerebral cortex and hippocampus

To explore molecular controlling mechanism of mitochondrial injury induced by different density of microwave irradiation. Rats were exposed to microwave irradiation for 1 hour at average power density of 3 mW/cm(2) or 30 mW/cm(2). After microwave irradiation, the changes of pathological ultrastructure of rat cerebral cortex and hippocampus were observed by electron microscope, and mitochondrial transcription factor A (mtTFA) mRNA expression level were determined by RT-PCR. After 3 mW/cm(2) microwave irradiation for 0, 3, 24 h, mitochondrial ultrastructure and mtTFA mRNA expression level didn't significantly change in rat cerebral cortex and hippocampus. After 30 mW/cm(2) microwave irradiation for 0, 3, 24 h, mitochondrial ultrastructure obviously changed, mtTFA mRNA expression in rat hippocampus significantly increased by 67.00%, 80.00%, 30.00% respectively, and in rat cerebral cortex by 133.00%, 86.00%, 233.00% respectively. There were significant differences between the corresponding groups of hippocampus and cerebral cortex (P < 0.01). No obvious change in mitochondria was found after 3 mW/cm(2) microwave irradiation, but it was found after 30 mW/cm(2) microwave irradiation. Mitochondria injury in cerebral cortex was more severe than that in hippocampus. mtTFA mRNA may have certain regulation in mitochondrial energy metabolism.

Case for the Panel of Ultrastructural Pathology—Uterine Leiomyoma

Case for the Panel of Ultrastructural Pathology—Uterine Leiomyoma

Pathological findings associated with naturally acquired porcine circovirus type 2 associated disease

Porcine circovirus type 2 (PCV2) is a novel virus of the Circoviridae family which is considered the cause of postweaning multisystemic wasting syndrome (PMWS). PCV2 has also been associated to a number of pathological conditions of pigs, including porcine dermatitis and nephropathy syndrome, reproductive failure, porcine respiratory disease complex, proliferative and necrotising pneumonia and congenital tremor type AII. Pathological studies have been used to describe and characterise PMWS and these emerging conditions associated with PCV2. The objective of this review is to concentrate on the gross, microscopic and ultrastructural pathology associated with natural cases of PCV2 associated disease, along with some speculations on the pathogenesis of naturally occurring PMWS.

Case for the Panel of Ultrastructural Pathology

Case for the Panel of Ultrastructural Pathology

Organized Deposits in the Kidney and Look-Alikes

Organized or structured deposits are encountered during electron microscopic examination of kidney tissue in a wide variety of primary renal and multisystemic disorders. They are most commonly seen in the renal glomerulus, though extraglomerular sites are occasionally involved. In some cases, organized deposits herald the presence of a specific disease process. Included in this category are organized substances containing immunoglobulin molecules or parts thereof as well as non-immunoglobulin-containing materials that accumulate in several rare heritable disorders. A second broad category of structured deposits includes substances that accumulate in response to nonspecific tissue injuries. In many instances, such "look-alikes" can be difficult to distinguish from disease-specific structured deposits. Ultrastructural pathology is central to the detection and characterization of organized deposits in the kidney and is the primary focus of this paper. Correlative light microscopic studies are often useful, however, and will be described as well.

The "Ultra" Years and Many More to Come: A Glimpse into the Future

"The "Ultra" Years and Many More to Come: A Glimpse into the Future." Ultrastructural Pathology, 27(5), pp. 287–288

Ultrastructural Pathology of Smooth Muscle Tissue Surrounding Prostatic Adenocarcinoma

Ultrastructural Pathology of Smooth Muscle Tissue Surrounding Prostatic Adenocarcinoma

Identification of an electron densification of the glomerular basement membrane in renal biopsy specimens.

Ultrastructural examination of renal biopsy specimens is often necessary to establish a diagnosis. We have noted, in some renal biopsies, that normal-appearing glomerular basement membrane (GBM) shows an electron densification. The aim of this study was to describe this phenomenon and assess the degree of its occurrence. We reviewed ultrastructural pathology records of 153 renal biopsy patients with special reference to the careful examination of the electron micrographs. Of these, 28 cases (18%) showed a definite and homogeneous electron densification of normal-appearing GBM in the glomeruli. The pathological diagnosis in these cases was IgA nephropathy in 15, minimal change nephrotic syndrome in 6, interstitial nephritis in 3, membranoproliferative glomerulonephritis in 2, and nephritis of Henoch-Schonlein purpura and membranous nephropathy in 1 case each. In addition, frequent deposition of IgG without C3 in the GBM (86%) and glomerular endothelial cell edema (96%) were observed. No apparent correlation could be ascertained between the presence of the electron densification and pathological diagnosis. It is suggested that electron densification of the GBM may be caused by the penetration of some electron-dense materials into the GBM as a result of an abnormality in the glomerular filtration barrier and that this could be considered as a sign of altered properties of the lamina densa.

Ultrastructural pathology of myelinated fibers in schizophrenia: A morphometric study of prefrontal and visual cortex

The function of cellular prion protein (PrPC), which is a copper binding protein, remains unclear. To elucidate the mechanisms in which PrPC is involved in neuroprotection, we compared death signals in prion protein gene-deficient (Prnp−/−) primary cerebellar granular neurons (CGNs) to those with wild-type (WT) CGNs. When copper was exposed to these CGNs, ZrchI, and Rikn Prnp−/− CGNs were more sensitized and underwent apoptotic cell death more readily than WT CGNs. Furthermore, the level of intracellular hydrogen peroxide (H2O2) in WT CGNs increased by copper toxicity, whereas those in ZrchI and Rikn Prnp−/− CGNs did not. These results suggest that PrPC modulates the intracellular H2O2 level as a copper-binding protein to protect CGNs from apoptotic cell death possibly due to inhibiting a Fenton reaction.

Organized Deposits in the Kidney and Look-Alikes

Organized or structured deposits are encountered during electron microscopic examination of kidney tissue in a wide variety of primary renal and multisystemic disorders. They are most commonly seen in the renal glomerulus, though extraglomerular sites are occasionally involved. In some cases, organized deposits herald the presence of a specific disease process. Included in this category are organized substances containing immunoglobulin molecules or parts thereof as well as non-immunoglobulin-containing materials that accumulate in several rare heritable disorders. A second broad category of structured deposits includes substances that accumulate in response to nonspecific tissue injuries. In many instances, such "look-alikes" can be difficult to distinguish from disease-specific structured deposits. Ultrastructural pathology is central to the detection and characterization of organized deposits in the kidney and is the primary focus of this paper. Correlative light microscopic studies are often useful, however, and will be described as well.