A quantitative light and electron microscopic analysis of taurine-like immunoreactivity in the dorsal horn of the rat spinal cord.

Taurine has been proposed as an inhibitory neurotransmitter or neuromodulator in the vertebrate central nervous system. Within the spinal cord, taurine has been shown to have a direct inhibitory effect on spinal neurons and to have a selective antinociceptive effect on chemically induced nociception. Although sufficient data exists to suggest that taurine plays a neurotransmitter or neuromodulatory role in the spinal cord, it is not known whether this amino acid is present in axon terminals nor if this amino acid has a unique pattern of distribution within spinal tissue. To address these questions a monoclonal antibody against taurine was employed to localize taurine-like immunoreactivity in the dorsal horn of the rat spinal cord by using both light and electron microscopic techniques. Taurine-like immunoreactivity was most dense and most prominent in laminae I and II of the dorsal horn. A moderate amount of immunoreactivity was also present in laminae VIII and IX and X while the remaining laminae were only lightly stained. In laminae I and II taurine-like immunostaining was evident within neuronal cell bodies, dendrites, myelinated and unmyelinated axons, axon terminals, and astrocytes and their processes. Cell counts of these two laminae indicated that approximately 30% of neuronal perikarya at the C2 level, 52% of neuronal perikarya at the T6 level, and 18% of neuronal perikarya at the L2 level of the cord exhibited taurine-like immunoreactivity. With preembedding diaminobenzidine staining, approximately 20% of the axons examined in laminae I and II were found to be immunoreactive for taurine. Using postembedding immunogold staining in combination with quantitative procedures, the highest densities of gold particles were found in axon terminals containing pleomorphic vesicles and forming symmetrical synapses (36.8 particles/micron2), in a subpopulation of myelinated axons (34.2 particles/micron2), in a subpopulation of neuronal dendrites (32.6 particles/micron2), and in capillary endothelial cells (39.8 particles/micron2). Moderate labeling occurred in astrocytes (20.9 particles/micron2) and neuronal perikarya (18.7 particles/micron2). The localization of taurine to presumptive inhibitory axon terminals provides anatomical support for the hypothesis that taurine may serve an inhibitory neurotransmitter role in the superficial dorsal horn of the spinal cord. On the other hand, its localization to astrocytes and endothelial cells within both the dorsal ventral horns implies that it serves other nonneuronal functions as well.     

Cross-linking of cell surface ganglioside GM1 induces the selective apoptosis of mature CD+ T lymphocytes

Gangliosides are glycosphingolipids found ubiquitously on thesurface of mammalian cells. They contain a ceramide tail thatis inserted into the membrane and exposed carbohydrate and sialicacid moleties. The non-toxic B subunit oligomer (EtxB) of Escherichiacoli heat-labile enterotoxin (Etx) is a potent immunogen invivo and has profound modulatory effects on EtxB-primed lymphocytesin vitro, properties which are dependent on its ability to bindto GM1 ganglioside receptors. Here, it is shown that cross-linkingGM1 by EtxB causes a differential effect on mature CD4⁺ andCD8⁺ T cells from lymph node cultures proliferating in responseto an unrelated antigen, ovalbumin. Addition of EtxB to suchcultures led to the complete depletion of CD8⁺ T cells comparedwith enhanced activation of CD4⁺ T cells [as measured by expressionof CD25 (IL-2R)]. By contrast, addition of a mutant EtxB, EtxB(G33D),which does not bind to GM1, failed to trigger CD8⁺ T cell depletion.When EtxB was added to isolated non-immune CD8⁺ lymphocytesrapid (12–18 h) alterations in nuclear morphology andthe appearance of sub-G₀/G₁ levels of DNA were induced; propertieswhich are characteristic of cells undergoing apoptosis. EtxB(G33D)failed to trigger apoptosis, indicating that the induction ofthe apoptotic signal was dependent on the binding of GM1. Thesefindings provide an insight into the potent immunogenicity andimmunomodulatory properties of E. coli enterotoxins as wellas heralding a novel method for the selective induction of apoptosisin mature CD8⁺ T lymphocytes.     

Association of photobiomodulation therapy (PBMT) and exercises programs in pain and functional capacity of patients with knee osteoarthritis (KOA): a systematic review of randomized trials

Lasers in Medical Science - Knee osteoarthritis (KOA) is a common degenerative disease in which several treatments and treatment associations have been investigated. This review analyzed the...     

Establishment of a formal program for retinoblastoma: Feasibility of clinical coordination across borders and impact on outcome

Retinoblastoma is an ocular tumor that occurs in young children, in either heritable or sporadic manner. The relative rarity of retinoblastoma, and the need for expensive equipment, anesthesia, and pediatric ophthalmologic expertise, are barriers for effective treatment in developing countries. Also, with an average age‐adjusted incidence of two to five cases per million children, patient number limits development of local expertise in countries with small populations. Lebanon is a small country with a population of approximately 4.5 million. In 2012, a comprehensive retinoblastoma program was formalized at the Children's Cancer Institute (CCI) at the American University of Beirut Medical Center, and resources were allocated for efficient interdisciplinary coordination to attract patients from neighboring countries such as Syria and Iraq, where such specialized therapy is also lacking. Through this program, care was coordinated across hospitals and borders such that patients would receive scheduled chemotherapy at their institution, and monthly retinal examinations and focal laser therapy at the CCI in Lebanon. Our results show the feasibility of successful collaboration across borders, with excellent patient and physician adherence to treatment plans. This was accompanied by an increase in patient referrals, which enables continued expertise development. However, the majority of patients presented with advanced intraocular disease, necessitating enucleation in 90% of eyes in unilateral cases, and more than 50% of eyes in bilateral cases. Future efforts need to focus on expanding the program that reaches to additional hospitals in both countries, and promoting early diagnosis, for further improvement of globe salvage rates.     

Mnemonic to Assist in Management of Liver Cirrhosis

Cirrhosis is a challenge for nurse practitioners in terms of providing effective management. The goals of this article are to provide readers with a general view of the pathophysiological complications of cirrhosis and to describe a mnemonic to assist in its management. Using mnemonics has been shown to reduce clinical errors and improve adherence to best practices. Mnemonics provide immediate access to relevant knowledge of complex concepts. The use of a mnemonics strategy in cirrhosis acts as an aid for translating pathophysiological and pharmaco-therapeutic concepts into meaningful interventions.