PAS-positive Bodies Research Articles

A case of amoebic appendicitis in north Queensland

A 13-year-old female from Mornington Island presented with diarrhoea, vomiting, and abdominal pain. Laparoscopic investigation was performed and a gangrenous appendix removed. Histological examination was initially unremarkable, but a later review of the periodic acid-Schiff (PAS) stain demonstrated several areas of PAS-positive bodies consistent with invasive Entamoeba histolytica. Further testing was performed to confirm the diagnosis of E. histolytica, including serology and PCR from paraffinised tissue. The patient was treated with metronidazole and paromomycin to ensure treatment of both tissue and luminal phases of the parasite. This case highlights an unusual presentation of E. histolytica infection, and serves as a reminder that endemic transmission of this parasite is not only possible, but becoming increasingly recognised.

Extradural spinal cord lesion in a dog: First case study of canine neurological histoplasmosis in Italy

A 7-year-old intact male mixed dog was presented with a history of acute and progressive paraparesis. Abnormal clinical signs consisted of non-ambulatory paraparesis, hind limbs hypertonia and severe thoracolumbar pain. Magnetic resonance imaging demonstrated an isointense in T1 and T2 WI epidural lesion, with good contrast enhancement, extending from T-10 to T-13. Laminectomy was carried out to remove the epidural mass. Histological examination revealed a pyogranulomatous lesion characterized by numerous macrophages containing yeast-like Grocott and PAS-positive bodies. Immunohistochemistry and PCR performed on formalin-fixed paraffin-embedded tissue confirmed Histoplasma capsulatum as the causative agent.H. capsulatum has a worldwide distribution in temperate and subtropical climates but its presence as an autochthonous fungus in Europe is now recognized. To the authors’ knowledge this is the first report of canine histoplasmosis in Italy with lesion confined to the central nervous system.

Lafora's disease. An ultrastructural and histochemical study.

Cerebral biopsies of three patients aged 22, 18 and 16 years with myoclonic epilepsy contained Lafory bodies. Two were a brother and sister of consanguineous parents. The Lafora bodies occurred in most neurons but not in glial cells. The ultrastructure of these bodies showed a fibrillar and granular material in the perikaryon and neuropile. In some neurons small Lafora bodies were delimited by a double membrane, suggesting that in early phases they have a membrene which disappears when they become more developed. Other non-specific neuron alterations are described. One of the cases presented in the liver PAS positive bodies of a structure different from the Lafora bodies.

Pulmonary Granulomas Associated with PAS-Positive Bodies in Brachycephalic Dogs

Pulmonary Granulomas Associated with PAS-Positive Bodies in Brachycephalic Dogs

Electron Microscopy of an Intracellular Response of Tetrahymena Pyriformis to Fluids From Normal Animals

It was previously reported that log phase Tetrahymena pyriformis (strain WHg), washed free of growth medium, after mixing with normal human or rabbit serum or mouse ascites fluid, gave rise after several hours to numerous large and small bodies in the cytoplasm, as visualized by the light microscope. Generally, the large bodies remained in the posterior portion of the animal, while the small ones were localized near the anterior end. Stained preparations showed small Sudan IV positive bodies and large PAS positive bodies. Electron micrographs also identified the small bodies as lipid and showed the large ones to be enclosed within a membrane (Fig. 1) and unlike anything yet described for this organism. Whether all these large bodies correspond to the PAS positive bodies on the slide preparations is uncertain.

Pulmonary Granulomas Associated with PAS-Positive Bodies in Brachycephalic Dogs.

Pulmonary granulomas were incidental findings at necropsy in 18 dogs, mainly of the brachycephalic breeds. These lesions were multifocal along smaller bronchi and the subpleural tissue at the margins of lobes. The granulomatous reaction contained numerous periodic acid-Schiff (PAS)-positive bodies that histochemically had reactions suggestive of a calcium-lipid-mucopolysaccharide complex. Although the cause is not clear, the location and distribution are suggestive of an inhalation or aspiration pneumonia. The shortened muzzle of brachycephalic breeds, particularly when there is concurrent upper respiratory disease, may predispose them to these bodies.

Keratinocyte Glycogen: An Ultrastructural Study of the Epidermal Response to Galactosamine and Glucose in Organ Culture

D-galactosamine produces in vitro a striking change in the epidermis with the appearance of large PAS-positive cytoplasmic bodies. The effectiveness of galactosamine in eliciting this response was compared with glucose, glucosamine, and galactose. Explants of normal-appearing skin from 42 patients were maintained in organ culture with basal medium alone containing 100 mg% glucose or in media to which sugars had been added to give final concentrations of 1100 mg% glucose, 100 mg% glucose and 1000 mg% glucosamine, 100 mg% glucose and 1000 mg% galactose, or 100 mg% glucose and 100 mg% galactosamine. The explants were removed in 3–7 days, processed for light and electron microscopic examination and graded for the presence of PAS-positive material. Galactosamine alone produced a marked and consistent response in the epidermis which was statistically greater than the response to the other sugars. Contrary to previous report the PAS-positive bodies are diastase-labile and on ultrastructural examination are composed of 700–800 AU granules resembling the alpha, or rosette, form of glycogen a form of glycogen not normally present in the epidermis. Glycogen induced by the presence of glucose alone appeared in the form of 300–400 AU particles normal for epidermis.

Lysosomal changes in epithelial cells of the mouse thymus after hydrocortisone treatment.

A cytochemical and biochemical study was made of lysosomal changes in epithelial cells of mouse thymus before and after hydrocortisone treatment. In untreated mouse thymus, acid phosphatase is present mainly in the golgi vesicles and occasionally in lysosomes. There is a delayed lysosomal response (12 hours) after treatment, with acid phosphatase activity reaching its maximum during the peak of involution (18–36 hours). During this period most of the enzyme activity is confined to the lysosomes. The pattern of distribution of histochemically demonstrable lysosomal enzymes bears a close resemblance to that of PAS positive bodies. It has been postulated that the lymphopoietic stimulating factor(s) is secreted in these PAS positive structures. On the basis of this assumption, it is suggested that lysosomal enzymes which are found to be present in the secretory vacuoles mediate the breakdown and release of this factor(s), in the manner of other endocrine glands.

Human cytomegalovirus. Cytochemical observations of intracellular lesion development correlated with viral synthesis and release

The evolution of the intracytoplasmic and intranuclear lesions produced by a human cytomegalovirus in human embryo cells is described and the lesions characterized cytochemically. Twenty-four hours after infection basophilic, lipid-containing, PAS-positive bodies surrounded by a halo containing RNA appear in a juxtanuclear position in the cytoplasm. Forty-eight hours after infection amphophilic patches that contain DNA and viral antigen appear in the nucleus. The cytoplasmic lesion also contains viral antigen at this time. Seventy-two hours after infection, the cytoplasmic lesion contains DNA and the nucleus is significantly enlarged. At about this time, infectious virus is first found intracellularly, and shortly thereafter release into the medium begins.