36 research outputs found
Hepatic arterioportal malformation in a dog - case report
ABSTRACT Arterioportal communications are complex hepatic vascular abnormalities. These are rarely seen in dogs and typically manifest as neurological, gastrointestinal, and developmental changes. This report describes clinical, laboratory and imaging findings associated with hepatic arterioportal malformation in a male Shih-Tzu dog aged 12 months. The diagnosis was achieved using computed tomographic angiography. The therapeutic approach selected consisted of palliative medical management (diuretics) combined with dietary protein restriction (3.6 g/100 kcal) provided by hepatic diet and gut activity modulation using lactulose. Surgical intervention was not recommended due to the complexity of vascular changes and portal hypertension. Despite initial clinical improvement, the patient died of disease-related complications seven months after diagnosis. Computed tomographic angiography was vital for accurate diagnosis and treatment selection, that needs to be more investigated
Law of Genome Evolution Direction : Coding Information Quantity Grows
The problem of the directionality of genome evolution is studied. Based on
the analysis of C-value paradox and the evolution of genome size we propose
that the function-coding information quantity of a genome always grows in the
course of evolution through sequence duplication, expansion of code, and gene
transfer from outside. The function-coding information quantity of a genome
consists of two parts, p-coding information quantity which encodes functional
protein and n-coding information quantity which encodes other functional
elements except amino acid sequence. The evidences on the evolutionary law
about the function-coding information quantity are listed. The needs of
function is the motive force for the expansion of coding information quantity
and the information quantity expansion is the way to make functional innovation
and extension for a species. So, the increase of coding information quantity of
a genome is a measure of the acquired new function and it determines the
directionality of genome evolution.Comment: 16 page
Epigenetic control of nuclear architecture
The cell nucleus is a highly structured compartment where nuclear components are thought to localize in non-random positions. Correct positioning of large chromatin domains may have a direct impact on the localization of other nuclear components, and can therefore influence the global functionality of the nuclear compartment. DNA methylation of cytosine residues in CpG dinucleotides is a prominent epigenetic modification of the chromatin fiber. DNA methylation, in conjunction with the biochemical modification pattern of histone tails, is known to lock chromatin in a close and transcriptionally inactive conformation. The relationship between DNA methylation and large-scale organization of nuclear architecture, however, is poorly understood. Here we briefly summarize present concepts of nuclear architecture and current data supporting a link between DNA methylation and the maintenance of large-scale nuclear organization
Duas abordagens artroscópicas para a articulação escapulo umeral no cão Two arthroscopic approaches for the shoulder joint in dog
O objetivo deste trabalho foi estudar em cadáveres de cães a exeqüibilidade do exame das estruturas intra-articulares através de duas diferentes abordagens artroscópicas da articulação escápulo-umeral. As articulações constituíram dois grupos: (A) o portal artroscópico foi estabelecido cranial e o portal instrumental caudal ao processo acromial; (B) o portal artroscópico foi confeccionado caudal e o portal instrumental cranial ao processo acromial. Durante o exame, procurou-se avaliar a possibilidade de visibilização concomitante com o toque através de sonda nas estruturas intra-articulares: cartilagem da cabeça do úmero (cranial, media e caudal), cavidade glenóide, tendão do músculo bíceps braquial, tendão do músculo subescapular, ligamento glenoumeral medial e lateral e bolsa articular caudal. As estruturas localizadas na porção cranial e média da articulação foram mais bem examinadas pela abordagem artroscópica realizada no grupo B, enquanto que aquelas estruturas situadas na porção média e caudal da articulação foram mais bem acessadas pela técnica utilizada no grupo A. Em nenhuma das abordagens, o ligamento glenoumeral lateral foi satisfatoriamente examinado.<br>This research was aimed at studing in dog corpses the feasibility of the exam of the intrarticular structures by using two different arthroscopic shoulder approaches. The joints were assembled in two groups: (A) the arthroscopic portal was established cranially and the instrumental portal caudally to the acromial process; (B) the arthroscopic portal was established caudally and the instrumental portal cranially to the acromial process. At the time of the exam the possibility of arthroscopic visualization concurrently with the touch with the probe of the intra articular structures was evaluated: humeral head cartilage (cranial, midlle and caudal), glenoid cavity, brachial biceps muscle tendon, subscapularis muscle tendon, medial and lateral glenohumeral ligament and caudal joint pouch. The intra articular structures situated in the cranial and middle side of the joint were better examined by approaching used in B group. On the other hand the structures localized in the caudal and middle portions of the joint were better inspected by approaching used in A group. However the lateral glenohumeral ligament was not completely checked neither using the A group approach nor using the B group approach
Phototrexate : a novel drug candidate for cancer and psoriasis
Antifolates are structural analogs of folates, essential one-carbon donors in the synthesis of DNA in mammalian cells, and they work as inhibitors of key enzymes in folate metabolism, such as dihydrofolate reductase and thymidylate synthetase. Methotrexate (MTX) was one of the first agents of this class and is still extensively used in the treatment of a variety of tumors, including acute lymphocytic leukemia, breast cancer, osteosarcoma, primary central nervous system lymphoma, and head and neck cancer. Above all, it is also commonly used in certain autoimmune diseases, such as rheumatoid arthritis or psoriasis. However, the clinical efficacy of MTX is often limited and compromised by toxic dose-related side effects, which leads to morbidity, interruption of the treatment, and occasional mortality. A promising approach to tackle this problem is to activate the drug exclusively at its desired place of action. In fact, in those diseases that would benefit from a highly localized treatment, a precise spatiotemporal control over the activity of a chemotherapeutic agent would allow reducing the concentration of active compound outside the target tissue, improving the tolerability and hence the efficacy of the treatment. Light is a powerful tool in this respect: it offers unparalleled opportunities as a non-invasive regulatory signal for pharmacological applications because it can be delivered with high precision regarding space, time, intensity and wavelength. We have recently developed Phototrexate, the first photoswitchable antifolate, by incorporation of a photochromic unit into the structure of MTX. Phototrexate was designed to be constitutively inactive in its thermodynamically stable configuration (E isomer), while it can be activated with light (Z isomer) to locally provide the pharmacological effects of the parent drug, as confirmed in our earlier experiments in vitro and in zebrafish larvae. Studies are currently underway to assess safety/tolerability, pharmacokinetics, pharmacodynamics, and efficacy of our compound in vitro and in preclinical animal models. All current results indicate that Phototrexate is a drug candidate with high potential for development as an innovative light-regulated antifolate for cancer and psoriasis