Isolated Acute Terminal Ileitis Without Preexisting Inflammatory Bowel Disease Rarely Progresses to Crohn’s Disease

Digestive Diseases and Sciences - Isolated acute terminal ileitis without chronic features of inflammation poses a diagnostic challenge. Few studies have investigated the clinical significance of...     

Structural basis for mechanical transduction in the frog vestibular sensory apparatus: I. The otolithic membrane

The mechanical coupling of the otoliths to the hair cell sensory stereocilia at the surface of the vestibular sensory epithelium is mediated by two layers of extracellular matrix, each one with a specific role in the mechanical transduction process. The first is a rigid layer in direct contact with the otolithic mass and is known as the otolithic membrane or gelatin membrane. This structure consists of a dense, randomly cross linked filament network that uniformly distributes the force of inertia of the non-uniform otolithic mass to all stereocilia bundles. The second layer formed by a columnar organization of filaments secures the otolithic membrane above the surface of the epithelium. The long columnar filaments are organized in parallel to the stereocilia bundles and are anchored to the apical surface of the supporting cells. The zonula adherens at the apical region of each supporting cell displays a thick polygonal bundle of actin filaments forming at the surface of the epithelium a transcellular honeycomb organization that provides mechanical ground support for the columnar filament layer. The dominant aspect of this columnar filament layer indicates that it may also have an important role in attenuating the force of inertia of the large otolithic mass during acceleration, screening stresses that would be directed to an effective bending of the stereocilia bundles.     

Identification of glycinergic synapses in the cochlear nucleus through immunocytochemical localization of the postsynaptic receptor

The distribution and morphology of glycinergic synapses in the cochlear nucleus were investigated using monoclonal antibodies against the glycine receptor. Glycine receptor immunoreactivity was seen on somas and proximal processes of most cells in all divisions of the cochlear nucleus; distribution of label in neuropil was denser in the dorsal cochlear nucleus and granule cell cap than in the ventral cochlear nucleus. At the ultrastructural level, glycine receptor immunoreactivity was specifically distributed postsynaptically to terminals that contained flattened vesicles in the guinea pig anteroventral cochlear nucleus. These studies show that the immunocytochemical localization of the glycine receptor can provide a means of identifying and characterizing glycinergic synapses throughout the central nervous system.     

Localization of enkephalin-like immunoreactivity in acetylcholinesterase-positive cells in the guinea-pig lateral superior olivary complex that project to the cochlea

Olivocochlear fibers have been demonstrated to have acetylcholinesterase-positive staining both in brainstem and cochlea. Olivocochlear fibres in the cochlea have also been determined to contain enkephalin-like immunoreactivity. In this study, we first determined the source of olivocochlear fibers in the guinea-pig using horseradish peroxidase and wheat germ agglutinin in retrograde transport studies. These cells were then examined for enkephalin-like immunoreactivity followed by acetylcholinesterase staining on the same sections to determine which cells and fibers showed staining for both. It was found that cells in the guinea-pig lateral superior olive that project to the cochlea have both enkephalin-like immunoreactivity staining and acetylcholinesterase-positive staining. Cells in other areas giving rise to olivocochlear fibers showed only acetylcholinesterase staining. These results suggest that there is co-localization of enkephalin and acetylcholine in a population of olivocochlear cells and fibers.     

Aspartate aminotransferase immunoreactivity in cochlea of guinea pig

The distribution of aspartate aminotransferase-like immunoreactivity in the cochlea of the guinea pig was studied at the light microscopy level. Indirect immunofluorescence histochemistry using antisera against cytoplasmic aspartate aminotransferase prepared from pig heart was applied to surface preparations of the organ of Corti and cryostat sections of the cochlea. In the modiolus, immunofluorescence was localized to spiral ganglion cells and myelinated fibers of the auditory nerve and intraganglionic spiral bundles. In the organ of Corti, immunofluorescence was seen in upper tunnel crossing fibers and at the base of outer hair cells, following a distribution similar to that of the efferent innervation of the outer hair cells. Weak immunofluorescence was seen in the inner spiral bundle and tunnel spiral bundle, but was not present in all preparations. Immunofluorescence was not seen in inner hair cells, nor at the base of inner hair cells, and may have been absent from outer hair cells.It is concluded that spiral ganglion cells and myelinated auditory nerve axons contain aspartate aminotransferase-like immunoreactivity; such immunoreactivity has previously been determined in auditory nerve endings in the cochlear nucleus. Olivocochlear neurons that innervate outer hair cells also contain such immunoreactivity while other cochlear efferents contain little or none.     

Fulminant pertussis: A multi‐center study with new insights into the clinico‐pathological mechanisms

Pertussis carries a high risk of mortality in very young infants. The mechanism of refractory cardio‐respiratory failure is complex and not clearly delineated. We aimed to examine the clinico‐pathological features and suggest how they may be related to outcome, by multi‐center review of clinical records and post‐mortem findings of 10 patients with fulminant pertussis (FP). All cases were less than 8 weeks of age, and required ventilation for worsening respiratory symptoms and inotropic support for severe hemodynamic compromise. All died or underwent extra corporeal membrane oxygenation (ECMO) within 1 week. All had increased leukocyte counts (from 54 to 132 × 10⁹/L) with prominent neutrophilia in 9/10. The post‐mortem demonstrated necrotizing bronchitis and bronchiolitis with extensive areas of necrosis of the alveolar epithelium. Hyaline membranes were present in those cases with viral co‐infection. Pulmonary blood vessels were filled with leukocytes without well‐organized thrombi. Immunodepletion of the thymus, spleen, and lymph nodes was a common feature. Other organisms were isolated as follows; 2/10 cases Para influenza type 3, 2/10 Moraxella catarrhalis, 1/10 each with respiratory syncytial virus (RSV), a coliform organism, methicillin‐resistant Staphylococcus aureus (MRSA), Haemophilus influenzae, Stenotrophomonas maltophilia, methicillin‐sensitive Staphylococcus aureus (MSSA), and candida tropicalis. We postulate that severe hypoxemia and intractable cardiac failure may be due to the effects of pertussis toxin, necrotizing bronchiolitis, extensive damage to the alveolar epithelium, tenacious airway secretions, and possibly leukostasis with activation of the immunological cascade, all contributing to increased pulmonary vascular resistance. Cellular apoptosis appeared to underlay much of these changes. The secondary immuno‐compromise may facilitate co‐infection. Pediatr Pulmonol. 2009; 44:970–980. ©2009 Wiley‐Liss, Inc.     

Challenges of emerging adulthood-transition from paediatric to adult diabetes

Diabetes mellitus is a complex condition with far reaching physical, psychological and psychosocial effects. These outcomes can be significant when considering the care of a youth transferring from paediatric through to adult diabetes services. The art of mastering a smooth care transfer is crucial if not pivotal to optimising overall diabetic control. Quite often the nature of consultation varies between the two service providers and the objectives and outcomes will mirror this. The purpose of this review is to analyse the particular challenges and barriers one might expect to encounter when transferring these services over to an adult care provider. Particular emphasis is paid towards the psychological aspects of this delicate period, which needs to be recognised and appreciated appropriately in order to understand the particular plights a young diabetic child will be challenged with. We explore the approaches that can be positively adopted in order to improve the experience for child, parents and also the multi- disciplinary team concerned with the overall delivery of this care. Finally we will close with reflection on the potential areas for future development that will ultimately aim to improve long-term outcomes and experiences of the young adolescent confronted with diabetes as well as the burden of disease and burden of cost of disease.     

Immunocytochemical localization of choline acetyltransferase-like immunoreactivity in the guinea pig cochlea

The immunocytochemical localization of the enzyme choline acetyltransferase (ChAT) was examined in the guinea pig organ of Corti to determine if both lateral and medial systems of efferents would show immunoreactive labeling for this specific enzyme marker of cholinergic neurons. Cochleae were also examined after lesion of efferents to determine if ChAT-like immunoreactivity is confined to efferents. ChAT-like immunoreactivity was seen in the inner spiral bundle, tunnel spiral bundle and by the bases of inner hair cells corresponding to the lateral system of efferents. ChAT-like immunoreactivity was also seen in crossing fibers and puncta at the bases and by the nuclei of outer hair cells corresponding to the medial system of efferents. With the use of video enhanced contrast microscopy more than 9 ChAT-like immunoreactive puncta at the bases of outer hair cells could be resolved. In cochleae examined 6 weeks after ipsilateral lesion of efferents, no ChAT-like immunoreactivity was observed. These results add strong evidence that acetylcholine is a transmitter of both the medial and lateral systems of efferents.     

Cyclical changes in the vaginal epithelium of the rat seen by scanning electron microscopy

Keratinization or mucification of the epithelium of the rat vagina is related to the hormonal state of the animal. During the normal cycle and after the administration of exogenous hormones (estrogen and progestin) to spayed animals, the surface characteristics and topography of the vaginal epithelium were studied with the scanning electron microscope. During estrus and under the influence of estrogen, the superficial cells were keratinized, overlap each other like shingles, and are continuously sloughed off. Like the surface of other keratinizing epithelia, theirs has a characteristic microridge pattern. In ovariectomized animals, the apical surface is covered with microvilli instead of microridges, and the cells resemble hexagonally shaped units, tightly bound instead of overlapping each other. At the boundary between the cells, a ridge demarcates the cells. The surface configurations of progestin-treated, progestin plus estrogen-treated, and diestrous animals are the same as in spayed animals.