GEOMETRICAL STRING and DUAL SPIN SYSTEMS

We are able to perform the duality transformation of the spin system which was found before as a lattice realization of the string with linear action. In four and higher dimensions this spin system can be described in terms of a two-plaquette gauge Hamiltonian. The duality transformation is constructed in geometrical and algebraic language. The dual Hamiltonian represents a new type of spin system with local gauge invariance. At each vertex $\xi$ there are $d(d-1)/2$ Ising spins $\Lambda_{\mu,\nu}= \Lambda_{\nu,\mu}$, $\mu \neq \nu = 1,..,d$ and one Ising spin $\Gamma$ on every link $(\xi,\xi +e_{\mu})$. For the frozen spin $\Gamma \equiv 1$ the dual Hamiltonian factorizes into $d(d-1)/2$ two-dimensional Ising ferromagnets and into antiferromagnets in the case $\Gamma \equiv -1$. For fluctuating $\Gamma$ it is a sort of spin glass system with local gauge invariance. The generalization to $p$-branes is given.Comment: 16 pages,Late

IGF-1 induces skeletal myocyte hypertrophy through calcineurin in association with GATA-2 and NF-ATc1

Localized synthesis of insulin-like growth factors (IGFs) has been broadly implicated in skeletal muscle growth, hypertrophy and regeneration(1). Virally delivered IGF-1 genes induce local skeletal muscle hypertrophy and attenuate age-related skeletal muscle atrophy, restoring and improving muscle mass and strength in mice(2), Here we show that the molecular pathways underlying the hypertrophic action of IGF-1 in skeletal muscle are similar to those responsible for cardiac hypertrophy, Transfected IGF-1 gene expression in postmitotic skeletal myocytes activates calcineurin-mediated calcium signalling by inducing calcineurin transcripts and nuclear localization of calcineurin protein. Expression of activated calcineurin mimics the effects of IGF-1, whereas expression of a dominant-negative calcineurin mutant or addition of cyclosporin, a calcineurin inhibitor, represses myocyte differentiation and hypertrophy. Either IGF-1 or activated calcineurin induces expression of the transcription factor GATA-2, which accumulates in a subset of myocyte nuclei, where it associates with calcineurin and a specific dephosphorylated isoform of the transcription factor NF-ATc1. Thus, IGF-1 induces calcineurin-mediated signalling and activation of GATA-2, a marker of skeletal muscle hypertrophy, which cooperates with selected NF-ATc isoforms to activate gene expression programs

Protocolo de tratamiento de cicatrices queloides en el pabellón auricular del Hospital General Dr. Manuel Gea González Treatment protocol of auricular keloid scars in the General Hospital Dr. Manuel Gea González

Las cicatrices queloideas son una de las patologías de más difícil tratamiento por el alto porcentaje de recidivas que presentan, hasta un 100 % en tratamientos únicos y un 50 % en tratamientos combinados. El pabellón auricular es un blanco frecuente de esta patología. Presentamos el protocolo de tratamiento empleado en nuestro hospital en los últimos 6 años con terapia combinada en 51 pacientes y 64 pabellones auriculares afectados por queloides. Aplicamos de forma preoperatoria 3 dosis de triamcinolona o betametasona intralesional, con diferencia de 4 a 6 semanas entre dosis y 4 semanas después de la última dosis, realizamos resección de la cicatriz dejando piel suficiente para el cierre sin tensión. En los pacientes que presentaban antecedente de resección quirúrgica se añadió al tratamiento el uso de colchicina, comenzando el día de la cirugía y manteniéndolo durante 8 semanas, a dosis de 1 mg. al día, con control de pruebas de función hepática pre y postratamiento. En el 74.5 % de los casos la cicatriz queloide fue unilateral; el 56.8 % de los pacientes fueron mujeres; las edades fluctuaron entre los 8 y los 61 años con una media de 24 años de edad. En el 65 % de los casos el queloide se presentó en el pabellón auricular derecho y en cuanto a su localización dentro del mismo, el 42 % se presentó en el lóbulo. La causa en el 56 % de los casos fue por perforación. El 18.6 % de las cicatrices tratadas cedieron con la infiltración intralesional; de las 48 cicatrices que recibieron tratamiento quirúrgico, hubo recidiva en el 12.5 % (6 cicatrices), con un seguimiento de entre 8 meses a 6 años.<br>Keloid scars are one of the most difficult pathologies to treat because its high rate of recurrence, from 100 % with single treatment to 50 % with combined therapy. The auricle is a frequent localization of keloids. We report our experience in the last 6 years with combined therapy in 51 patients and 64 auricles with keloid scars.: All scars were injected with triamcinolone or betamethasone 3 times with 4-6 weeks between each injection. Four weeks after the last injection, the keloids were excised and skin closure was done without tension. In those patients with history of surgical excision, we added to the treatment colchicine, 1 mg daily, for 8 weeks with hepatic function test before and after the administration of colchicine. The keloid was unilateral in 74.5 % of the cases; 56.8 % females; the age of presentation was between 8 and 61 years old, with a media of 24 years old.The right auricle was affected in 65 % and the most frequently affected area was the lobule in 42 %.The etiology in 56 % of the cases were secondary to piercing. In 18.6 % of the cases the scar was resolved with the intralesional injection of triamcinolone or betametasone. From the 48 excisions performed, 12.5 % (6 keloid scars) presented recurrence, with a follow up of 8 months to 6 years