Potential benefits of melatonin in organ transplantation: a review

Organ transplantation is a useful therapeutic tool for patients with end-stage organ failure; however, graft rejection is a major obstacle in terms of a successful treatment. Rejection is usually a consequence of a complex immunological and nonimmunological antigen-independent cascade of events, including free radical-mediated ischemia-reperfusion injury (IRI). To reduce the frequency of this outcome, continuing improvements in the efficacy of antirejection drugs are a top priority to enhance the long-term survival of transplant recipients. Melatonin (N-acetyl-5-methoxytryptamine) is a powerful antioxidant and ant-inflammatory agent synthesized from the essential amino acid L-tryptophan; it is produced by the pineal gland as well as by many other organs including ovary, testes, bone marrow, gut, placenta, and liver. Melatonin has proven to be a potentially useful therapeutic tool in the reduction of graft rejection. Its benefits are based on its direct actions as a free radical scavenger as well as its indirect antioxidative actions in the stimulation of the cellular antioxidant defense system. Moreover, it has significant anti-inflammatory activity. Melatonin has been found to improve the beneficial effects of preservation fluids when they are enriched with the indoleamine. This article reviews the experimental evidence that melatonin is useful in reducing graft failure, especially in cardiac, bone, otolaryngology, ovarian, testicular, lung, pancreas, kidney, and liver transplantation

Gamma-aminobutyric acid (GABA) Neurons and Perineuronal Nets (PNN) in the Monodelphis domestica and Relevance to Psychiatric Disorders

Background/ Purpose: Gamma-aminobutyric acid (GABA) is an amino acid that serves as the central nervous system’s (CNS) main inhibitory neurotransmitter. By inhibiting nerve transmission, it works to lower neuronal excitability. Altered GABA levels have been associated with a variety of psychiatric disorders, for example Epilepsies, Parkinson’s Disease, and Schizophrenia. Perineuronal nets (PNN) are extracellular molecules that are released by neurons and glial cells that modulate many neuronal and glial functions by encapsulating the inhibitory cells and neurites. Altered PNN levels serve as a potential trigger to synaptic imbalance. The purpose of this study is to quantify and analyze the presence, change in number, and area difference of GAD67 and Lectin in the brain of the Monodelphis domestica. Methods: Two Monodelphis domestica were transcardially perfused with 4% paraformaldehyde and brains were collected and sliced at a thickness of 35 µm. An antibody for Glutamic Acid Decarboxylase (GAD_67) was used to identify GABAergic neurons and Lectin to identify the Perineuronal Nets, following the ABC-DAB method of immunohistochemistry. The criteria for identifying GAD-positive neurons and PNNs include presence of a dark brown reaction within the perikaryal cytoplasm. Using Image J software and stereological methods, midbrain sections targeting the Superior Colliculus Sensory and Motor and Substantia Nigra were used to compare the number of GABA cells and PNNs that were present. Moreover, a t-test and an ANOVA test were used to determine whether there was a statistically significant difference between the areas of the brain regions in focus. The average areas were obtained from 10 neurons for the GAD67 neurons antibody and Lectin in 4 different brain figures. Results: GAD67 antibody and Lectin were both used to identify GABAergic neurons and PNNs, respectively. GAD67 neurons were smaller and had a less clearly defined cell body and nucleus than PNNs. Based on preliminary quantification of GAD67 neurons, the number of GAD67 neurons in the Superior Colliculus and the Substantia Nigra were significantly higher in animals under a social stimulus than the control group. Conclusion: Our findings support the relevant literature regarding the way in which GAD67 and PNNs are expressed. By assessing the change in number and area difference in various regions of the brain, our recent findings will contribute to the use of Monodelphis as a model for neurological illnesses. Furthermore, we plan to relate our findings between GABAergic neurons and PNNs to hypothesize a connection between neural morphometry and connectivity and establish a relationship (or lack of relationship) between them

Polygenic analysis of ammonia-oxidizing bacteria using 16S rDNA, amoA, and amoB genes

Finding a unique molecular marker capable of quickly providing rigorous and useful phylogenetic information would facilitate assessing the diversity of ammonia-oxidizing bacteria in environmental samples. Since only one of several available markers can be used at a time in these kinds of studies, the 16S rDNA, amoA and amoB genes were evaluated individually and then compared in order to identify the one that best fits the information provided by the composite dataset. Distance-based neighbor-joining and maximum parsimony trees generated using the sequences of the three mentioned genes were analyzed with respect to the combined polygenic trees. Maximum parsimony trees were found to be more accurate than distance-based ones, and the polygenic topology was shown to best fit the information contained in the sequences. However, the taxonomic and phylogenetic information provided by the three markers separately was also valid. Therefore, either of the functional markers (amoA or amoB ) can be used to trace ammonia oxidizers in environmental studies in which only one gene can be targeted. [Int Microbiol 2005; 8(2):103-110

The introduction of modern physics: overcoming a deformed vision of science

In this paper, we try to show initially that modern physics is usually introduced in high school curricula without reference to the difficulties of classical physics, simply juxtaposing the two paradigms or even mixing them up. As a result, serious misconceptions arise. We then present another way of introducing modern physics, based on a contructivist view of science learning, and give some results obtained with the new materials

Bilateral Internuclear Ophthalmoplegia in a Patient with Devic's Neuromyelitis Optica

An unusual presentation of Devic's neuromyelitis optica (NMO) disease associated with bilateral internuclear ophthalmoplegia (INO) is described. A 32-year-old pregnant patient was diagnosed with NMO. First symptoms were headache and sudden visual loss in her right eye (RE). Eighteen months ago, she reported other neurologic symptoms such as paresthesia. Based on her visual field, fundoscopy and Ishihara test, she was diagnosed with retrobulbar neuritis of the RE. After delivery, new neurologic symptoms resembling transverse myelitis appeared. She was treated with methylprednisolone and plasmapheresis, which improved her visual acuity; however, a sudden bilateral INO appeared, with adduction defect and nystagmus with abduction in both eyes. No improvement was obtained after treatment with azathioprine and rituximab. Paresis of the legs and the right arm persisted, but double vision and OIN gradually disappeared. At the end, the patient had a residual exophoria in the RE and nystagmus with abduction in the left eye. Prevalence of NMO is lower than one case per one million inhabitants, and it is not likely to affect the encephalic trunk; furthermore, bilateral INO in NMO is rare. Two major criteria and at least two of the three minor ones are required to confirm a NMO diagnosis, and our patient fulfilled these diagnosis criteria

Inflation-Produced Magnetic Fields in Nonlinear Electrodynamics

We study the generation of primeval magnetic fields during inflation era in nonlinear theories of electrodynamics. Although the intensity of the produced fields strongly depends on characteristics of inflation and on the form of electromagnetic Lagrangian, our results do not exclude the possibility that these fields could be astrophysically interesting.Comment: 6 page

Ionized and neutral gas in the peculiar star/cluster complex in NGC 6946

The characteristics of ionized and HI gas in the peculiar star/cluster complex in NGC 6946, obtained with the 6-m telescope (BTA) SAO RAS, the Gemini North telescope, and the Westerbork Synthesis Radio Telescope (WSRT), are presented. The complex is unusual as hosting a super star cluster, the most massive known in an apparently non-interacting giant galaxy. It contains a number of smaller clusters and is bordered by a sharp C-shaped rim. We found that the complex is additionally unusual in having peculiar gas kinematics. The velocity field of the ionized gas reveals a deep oval minimum, ~300 pc in size, centered 7" east of the supercluster. The Vr of the ionized gas in the dip center is 100 km/s lower than in its surroundings, and emission lines within the dip appear to be shock excited. This dip is near the center of an HI hole and a semi-ring of HII regions. The HI (and less certainly, HII) velocity fields reveal expansion, with the velocity reaching ~30 km/s at a distance about 300 pc from the center of expansion, which is near the deep minimum position. The super star cluster is at the western rim of the minimum. The sharp western rim of the whole complex is plausibly a manifestation of a regular dust arc along the complex edge. Different hypotheses about the complex and the Vr depression origins are discussed, including a HVC/dark mini-halo impact, a BCD galaxy merging, and a gas outflow due to release of energy from the supercluster stars.Comment: MN RAS, accepte