The mouse vomeronasal glands: a light and electron microscopical study

The glands of adult mouse vomeronasal organ (VNO) were studiedwith light- and electro-microscopical techniques. The vomeronasalglands (VN-Gs) consist of several individual glandular complexesdistributed along the long axis of the VNO. The secretory productsreleased from VN-G cells enter into the lumen of the VNO inthe region of transition between the neuroepithelium and thereceptor-free epithelium. The acini show the typical morphologicalfeatures of serous glands. The secretory cells of these aciniare characterized by a round to oval nucleus and a well-developed,rough endoplasmic reticulum, both preferentially located inthe basal part of the cell. The supranuclear region is occupiedby the Golgi apparatus and secretory granules varying in sizeand electron density. They accumulate towards the apical partof the cell. Secretory cells are connected by tight junctions,desmosomes and membrane interdigitations, moreover, they arealso coupled by gap junctions. Axonal terminals containing clearvesicles and dense-cored vesicles are frequently seen betweenthe secretory cells. Secretory cells are directly related tothe thin basal lamina of the acinus; myoepithelial cells arenot present. In the lamina propria, numerous smooth muscle cells,blood vessels and nerve bundles containing both myelinated andunmyelinated axons can be observed. An automatic regulationof the activity of the VN-Gs is discussed in relation to thevomeronasal pump.     

GABA immunoreactivity in the human cerebellar cortex: a light and electron microscopical study

The distribution of gamma-aminobutyric acid (GABA) in surgical samples of human cerebellar cortex was studied by light and electron microscope immunocytochemistry using a polyclonal antibody generated in rabbit against GABA coupled to bovine serum albumin with glutaraldehyde. Observations by light microscopy revealed immunostained neuronal bodies and processes as well as axon terminals in all layers of the cerebellar cortex. Perikarya of stellate, basket and Golgi neurons showed evident GABA immunoreactivity. In contrast, perikarya of Purkinje neurons appeared to be negative or weakly positive. Immunoreactive tracts of longitudinally- or obliquely-sectioned neuronal processes and punctate elements, corresponding to axon terminals or cross-sectioned neuronal processes, showed a layer-specific pattern of distribution and were seen on the surface of neuronal bodies, in the neuropil and at microvessel walls. Electron microscope observations mainly focussed on the analysis of GABA-labelled axon terminals and of their relationships with neurons and microvessels. GABA-labelled terminals contained gold particles associated with pleomorphic vesicles and mitochondria and established symmetric synapses with neuronal bodies and dendrites in all cortex layers. GABA-labelled terminals associated with capillaries were seen to contact the perivascular glial processes, basal lamina and endothelial cells and to establish synapses with subendothelial unlabelled axons.     

An electron microscopical study of the human neurohypophysis

Summary The human posterior pituitary obtained at operation was studied with the electron microscope.The fine structure of the human neurohypophysis was found to be basically similar to that of the other mammalian and cold-blooded vertebrates examined.In addition to the nerve fibres and their swellings two cell types were seen: the pituicytes and the cells in the perivascular spaces — the fibroblasts.The distribution, size and shape of the pituicytes was variable. Long pituicyte processes were seen (sometimes > 20 in length) running between nerve fibres and their swellings, and ending on or in the perivascular space.Several types of large nerve swellings were seen: a) those containing only elementary granules, mitochondria and small vesicles; b) modified swellings characterised by contorted mitochondria and mitochondrial fragments. The latter were often surrounded by single or multiple highly osmiophilic myelin-like membranes; c) multilamellar bodies characterised by concentric osmiophilic myelin-like membranes or lamellae apparently dividing the swellings into separate compartments. The small vesicles, appearing in considerable numbers in such swellings, are suggested to originate from the osmiophilic lamellae.While some true synaptic vesicles may occur in non-secretory nerve fibres, the small vesicles (250–600 Å) seen in most nerve fibre swellings were thought to be derived from elementary granules.Repeated swellings were seen in individual nerve fibres and their functional significance discussed.The electron-dense material within the elementary granules was variable and is suggested to be dependent on the functional state of the neurohypophysis rather than on hormone content. Internal structure was often seen in the elementary granules. The impression is gained that the osmiophilic content of the elementary granules was composed of microvesicles possibly representing molecular aggregations of the hormone-neurophysin complex.     

Hemolymph cells of the bivalve mollusc Mercenaria mercenaria: an electron microscopical study.

The hemolymph cells of Mercenaria mercenaria were studied with the transmission electron microscope. Three morphological types of cells, granulocytes, hyalinocytes, and fibrocytes, are distinguishable and their fine structural characteristics are described. However, as a result of analyzing the fine structural features of the so-called fibrocytes of M. mercenaria, i.e., the inclusion of large aggregates of glycogen granules in their cytoplasm and the occurrence of primary phagosomes enclosing partially degraded exogenous material and digestive lamellae, it is suggested that fibrocytes are actually granulocytes which are at the terminal phase of their physiologic cycle relative to the degradation of phagocytized nonself materials. The cytoplasmic granules of M. mercenaria granulocytes are structurally different from those of Crassostrea virginica in that they are delimited by a unit membrane, rather than by a complex wall, and include a homogenously electron-dense material. Lipidlike droplets are reported from both granulocytes and hyalinocytes of M. mercenaria for the first time.     

Diprosopus: a unique case and review of the literature

BACKGROUND: We present a case of partial facial duplication in a male infant. METHODS: The clinical, radiological, and laboratory findings for this patient are described, followed by a review of the literature. RESULTS: Craniofacial duplication is a rare form of conjoined twinning and presents in a wide spectrum, from dicephalus to diprosopus to partial facial duplication. Many of these cases can be diagnosed prenatally. Prenatal assessment of our patient revealed only agenesis of the corpus callosum. CONCLUSIONS: The pathogenesis is believed to involve duplication of the notochord. Where there are more severe associated anomalies, the prognosis is poor. Partial facial duplication, as in our case, is associated with fewer anomalies, and the prognosis is better. Symmetry and an excess of tissue, rather than deficiency, favor a positive result.     

SUCLG1 mutations and mitochondrial encephalomyopathy: a case study and review of the literature

Molecular Biology Reports - The mitochondrial encephalomyopathies represent a clinically heterogeneous group of neurodegenerative disorders. The clinical phenotype of patients could be explained by...     

ICF syndrome: a new case and review of the literature

Patients with ICF syndrome can be recognized by the presence of a variable immunodeficiency, instability of the pericentromeric heterochromatin of, in particular, chromosomes 1, 9, and 16 in cultured peripheral lymphocytes, and a number of facial anomalies. Recently, aberrations at the molecular level have been described, consisting of alterations in the methylation pattern of classical satellite DNA, in a number of patients. ICF syndrome is considered to be inherited in an autosomal recessive manner and may be rare, as only 14 patients have been described thus far. We present a new case, a boy with agammaglobulinemia, who was extensively studied by means of classical cytogenetics and fluorescent in situ hybridization. All patients previously reported in the literature are reviewed.     

Townes-Brocks syndrome. Report of a case and review of the literature

The authors report a new case of Townes-Brocks syndrome with cardiac defect, ossicular anomalies and dominant transmission. The intrafamilial variability of the phenotype and the difficulty of diagnosis in isolated cases are underlined.     

A light and electron microscopical study of the green flagellateSpermatozopsis similis spec. nova

The green flagellateSpermatozopsis similis spec. nova has been studied in culture by light and electron microscopy. The flagellate bears two flagella, is naked and has a characteristic crescent and spirally twisted cell shape. The two flagella are of subequal length, each with a prominent hair-point. Each cell contains two contractile vacuoles, a single chloroplast with an anterior eyespot but lacking a pyrenoid, an anteriorly located nucleus, a single dictyosome associated with the posterior end of the nucleus, a single mitochondrion posterior to the nucleus and associated with a small microbody, some conspicuous vacuoles, and a greater number of secondary cytoskeletal microtubules which probably are responsible for maintaining the peculiar shape of this species. SinceS. similis in culture is only biflagellate, it cannot be accommodated within the quadriflagellate, but otherwise very similar speciesS. exsultans. Spermatozopsis similis is compared with other green flagellates and is shown to share common ultrastructural characters withChlamydomonas-type green algae.     

Small cell carcinoma of the stomach: an immunohistochemical and electron microscopic study.

A 4 x 6 cm ulcerative mass in the antrum was found to consist of papillary adenocarcinoma in the surrounding wall and the small round cell neoplasm at its base. Immunohistochemical staining revealed that elements of the papillary adenocarcinoma were positive for carcinoembryonic antigen, epithelial membrane antigen, keratin, endocrine granule constituent, and CA19-9, while components of the small cell carcinoma were weakly positive only for neuron-specific enolase. In one portion of the small cell carcinoma, particularly large cells with pleomorphic nuclei which were intensely positive for desmin were detected. Electron microscopic examination revealed dense-cored granules and intercellular junctions in the small neoplastic cells and bundles of intermediate filaments in the desmin-positive large cells. These findings suggest that ultrastructural examination is vital in diagnosis of small cell carcinoma and they reveal the capability of this carcinoma toward multidirectional differentiation.     

Primary cutaneous adenoid cystic carcinoma: a case report and review of the literature.

A case of adenoid cystic carcinoma of the ear in a 67-year-old man is presented along with a review of the literature. Adenoid cystic carcinoma most commonly arises in the salivary glands. Primary cutaneous adenoid cystic carcinoma occurs principally in the scalp and chest. Perineural invasion is seen in at least half the cases and is associated with an increased recurrence rate. Treatment consists of wide local resection with tumor-free margins. Just over half the patients will develop recurrence, with long tumor-free intervals necessitating long-term follow-up. Distant metastases are rarely seen. Radiation therapy is not curative and should be reserved for palliation.     

Hyperparathyroidism in pregnancy: case report and review of the literature.

The apparent incidence of hyperparathyroidism (HPT) is low in pregnancy but will likely increase now that more asymptomatic HPT is being diagnosed. However, since the serum calcium levels are decreased in pregnant women, mild primary HPT may go unrecognized. In untreated cases of HPT, complications during pregnancy or during the neonatal period have included spontaneous abortion, stillbirth, neonatal death, neonatal tetany and hypercalcemia. A review of the literature indicates a substantial improvement in fetal outcome when parathyroidectomy is done during pregnancy, as in the case reported here. Therefore, parathyroidectomy is the treatment of choice when the diagnosis is made during pregnancy, although oral phosphate therapy may be an alternative if surgery is contraindicated.     

The coating of mouse myocardial cells. A cytochemical electron microscopical study.

The coating of mouse myocardial cells has been investigated with a variety of cytochemical methods. The coating of the surface membrane gives a positive reaction with ruthenium red, colloidal thorium, phosphotungstic acid (PTA) at low pH, silver methenamine after periodic oxidation (PA-silver technique) and with silver proteinate after periodic oxidation and thiocarbohydrazide treatment (PA-TCH-silver technique). The coating of the T system gives almost similar results. The nexuses do not react with PTA nor with the PA-silver and PA-TCH-silver techniques, but they are strongly stained with ruthenium red which reveals periodic structures in their gaps. The specificities of the colloidal thorium technique and PAT staining have been tested by chemical treatments (methylation, acetylation, saponification), enzymatic digestions (pronase, trypsin, hyaluronidase, neuraminidase) and carbohydrate extractions (with 0.1 N NaOH and 0.05 M H2SO4). These cytochemical data indicate, considering the specificity of the reactions, that the coating of the membrane surface and the T system contains polyanionic groups. A part of them, at least, would belong to a carbohydrate-containing material (glycoproteins), whereas at the level of nexuses the sugar residues would probably be absent.