Subnuclear lipid-containing vacuolization in cases of ketoacidosis - correlation of morphological findings and ketone body concentrations

In a study on alcoholics, diabetics, cases of hypothermia, combinations of alcoholism, diabetes and hypothermia as well as 55 controls, ketone body measurements were performed in femoral vein blood, heart blood, vitreous humor, cerebrospinal fluid and urine. Histological investigations were carried out on the kidneys of the deceased. In addition to HE-staining, the cuts were stained with Sudan and PAS to allow differentiation between lipids and glycogens. The degree of stainability in the Sudan stains was correlated with the ketone body concentrations measured. In those cases in which elevated ketone body concentrations were measured, marked fat deposits in the renal tubular epithelial cells could be demonstrated with the Sudan staining method. The higher the stainability the higher the ketone body concentrations. The ketone body concentrations measured in the various body fluids correlated with the intensity of fat stainability.

Intranuclear Coccidiosis in Tortoises: Nine Cases

Chelonian intranuclear coccidiosis has been reported once, in two radiated tortoises ( Geochelone radiata), and is apparently rare. We describe intranuclear coccidiosis diagnosed histologically in two radiated tortoises, three Travancore tortoises ( Indotestudo forstenii), two leopard tortoises ( Geochelone pardalis), one bowsprit tortoise ( Chersina angulata), and one impressed tortoise ( Manouria impressa). Infection was systemic and involved alimentary, urogenital, respiratory, lymphoid, endocrine, and integumentary systems. Trophozoites, meronts, merozoites, macrogametocytes, microgametocytes, and nonsporulated oocysts were seen histologically or by electron microscopy. intracytoplasmic and extracellular stages of parasite development also were identified histologically. Sequencing of a coccidial 18S rRNA consensus polymerase chain reaction (PCR) product revealed a novel sequence that provided phylogenetic information and may be useful for further diagnostic test design. intranuclear coccidiosis was associated with variable degrees of inflammation in all cases, was considered the cause of death in six tortoises, and was a substantial contributing factor to the cause of death in two tortoises.

Cell nuclei spin in the absence of lamin b1

Mutations of the nuclear lamins cause a wide range of human diseases, including Emery-Dreifuss muscular dystrophy and Hutchinson-Gilford progeria syndrome. Defects in A-type lamins reduce nuclear structural integrity and affect transcriptional regulation, but few data exist on the biological role of B-type lamins. To assess the functional importance of lamin B1, we examined nuclear dynamics in fibroblasts from Lmnb1(Delta/Delta) and wild-type littermate embryos by time-lapse videomicroscopy. Here, we report that Lmnb1(Delta/Delta) cells displayed striking nuclear rotation, with approximately 90% of Lmnb1(Delta/Delta) nuclei rotating at least 90 degrees during an 8-h period. The rotation involved the nuclear interior as well as the nuclear envelope. The rotation of nuclei required an intact cytoskeletal network and was eliminated by expressing lamin B1 in cells. Nuclear rotation could also be abolished by expressing larger nesprin isoforms with long spectrin repeats. These findings demonstrate that lamin B1 serves a fundamental role within the nuclear envelope: anchoring the nucleus to the cytoskeleton.

Enterospora sp., an intranuclear microsporidian infection of hermit crab Eupagurus bernhardus

Recent work at our laboratory has led to the discovery of a new genus of microsporidian parasite residing in the family Enterocytozoonidae. The type species of this new genus, Enterospora canceri, is an intranuclear parasite infecting the hepatopancreatocytes of the decapod crustacean Cancer pagurus. Here we provide the second description of a parasite within the genus Enterospora, this time infecting the hermit crab Eupagurus bernhardus from U.K. waters. The pathological manifestation and ultrastructural features of the hermit crab parasite are very similar to those described for E. canceri. Further taxonomic comparisons based upon ultrastructural and molecular affinities of Enterospora are now required to define firmer links between this new genus within the Enterocytozoonidae and all other microsporidian families. The opportunistic nature of the discovery of a second intranuclear microsporidian within the Crustacea suggests that their presence may be more common than in higher animal groups.

Enterospora canceri n. gen., n. sp., intranuclear within the hepatopancreatocytes of the European edible crab Cancer pagurus

Only 1 genus (Nucleospora) within 1 family (Enterocytozoonidae) of the Microsporidia contains species that are parasitic within the nuclei of their host cells; to date, all described intranuclear Nucleospora spp. parasitise fish. This study describes the first intranuclear microsporidian parasite of an invertebrate, the European edible crab Cancer pagurus L. (Decapoda: Cancridae). Infected crabs displayed no obvious external signs, and maximum apparent prevalence of infection within a monthly sample was 3.45%. Infected hepatopancreatic tubules were characterised by varying numbers of hypertrophic and eosinophilic nuclei within epithelial cells. Parasite stages appeared as eosinophilic granular accumulations causing margination of host chromatin. In advanced cases, the tubule epithelia degenerated, with parasites and sloughed epithelial cells appearing in tubule lumens. All life stages of the parasite were observed within host nuclei. Uninucleate meronts were not detected, although binucleate stages were observed. Multinucleate plasmodia (sporogonal plasmodia) contained up to 22 nuclei in section, and late-stage plasmodia contained multiple copies of apparatus resembling the polar filament and anchoring disk, apparently associated with individual plasmodial nuclei. As such, aggregation and early assembly of sporoblast components took place within the intact sporogonial plasmodium, a feature unique to the Enterocytozoonidae. Liberation of sporoblasts from plasmodia or the presence of liberated sporoblasts was not observed in this study. However, large numbers of maturing and mature spores (measuring 1.3 +/- 0.02 x 0.7 +/- 0.01 microm) were frequently observed in direct contact with the host nucleoplasm. Considering the shared features of this parasite with microsporidians of the family Enterocytozoonidae, and the unique presence of this parasite within the nucleoplasm of decapod crustacean hepatopancreatocytes, this parasite (Enterospora canceri) is proposed as the type species of a new genus (Enterospora) of microsporidian. Molecular taxonomic work is now required, comparing Enterospora to Enterocytozoon and Nucleospora, the 2 other genera within the Enterocytozoonidae.

Interstitial Cajal-like cells (ICLC) in human resting mammary gland stroma. Transmission electron microscope (TEM) identification

We have previously shown the existence of ICLC in human resting mammary gland stroma by means of methylene blue (vital) staining and c-kit immunopositivity (immunofluorescence and immunohistochemistry). In addition, we reported the phenotype characteristics of these ICLC in vitro (primary cell cultures). Since the identification of ICLC outside the gut requires, at this moment, the obligatory use of TEM, we used this technique and provide unequivocal evidence for the presence of ICLC in the intralobular stroma of human resting mammary gland. According to the 'platinum standard' (10 TEM criteria for the certitude diagnosis of ICLC), we found interstitial cells with the following characteristics: 1. location: among the tubulo-alveolar structures, in the non-epithelial space; 2. caveolae: approximately 2.5% of cell volume; 3. mitochondria: approximately 10% of cell volume; 4. endoplasmic reticulum: either smooth or rough, approximately 2-3% of cell volume; 5. cytoskeleton: intermediate and thin filaments, as well as microtubules are present; 6. myosin thick filaments: undetectable; 7. basal lamina: occasionally found; 8. gap junctions: occasionally found; 9. close contacts with targets: nerve fibers, capillaries, immunoreactive cells by 'stromal synapses'; 10. characteristic cytoplasmic processes: i) number: frequently 2-3; ii) length: several tens of mum; iii) thickness: uneven caliber, 0.1-0.5 microm, with dilations, but very thin from the emerging point; iv) aspect: moniliform, usually with mitochondria located in dilations; v) branching: dichotomous pattern; vi) Ca(2+) release units: are present; vii) network labyrinthic system: overlapping cytoplasmic processes. It remains to be established which of the possible roles that we previously suggested for ICLC (e.g. juxta- and/or paracrine secretion, uncommited progenitor cells, immunological surveillance, intercellular signaling, etc.) are essential for the epithelium/stroma equilibrium in the mammary gland under normal or pathological conditions.