Neurofibromatosis tipo 1: seudoaneurisma de arteria temporal / Neurofibromatosis type 1: temporal artery pseudoaneurysm

Neurofibromatosis is a disease caused by a mutation on chromosome 17, and was described by Friedrich Daniel von Recklinghausen in 1882. It is characterized by the appearance of benign tumors in different organs that can occasionally turn malignant. Four types of neurofibromatosis are described; being type 1 the most frequent, produced by mutations in NF1 gene inhibiting neurofibromin, and in a small percentage of cases by 17q11 microdeletion. In 50% of cases, it is autosomal dominant and the penetrance is 100%. Its prevalence is 1/3000 births and affects both sexes equally. The diagnosis is done by the presence of characteristic signs and can be corroborated through genetic studies. It usually manifests in childhood and involves skin issues, formation of multiple neurofibromas, gliomas of the optic pathway, hamartomas of the iris, bone malformations, arterial hypertension, vascular alterations, intracranial and peripheral nerve sheath tumors, seizures, hydrocephalus, cognitive deficits and learning difficulties. Vascular disease is a rare complication that is usually asymptomatic and can affect the vessels that go from the proximal aorta to small arterioles, including arterial stenosis, aneurysms and arteriovenous malformations. The prognosis is usually good, with neoplasms and vascular diseases being the cause of early mortality. We present the case of a patient with a diagnosis of neurofibromatosis type 1 who presents a rupture of a pseudoaneurysm dependent on the left temporal artery with a fistula with drainage to the superficial facial vein that resulved favorably by endovascular treatment.

La neurofibromatosis es una enfermedad producida por una mutación en el cromosoma 17; fue descrita por Friedrich Daniel von Recklinghausen en 1882. Se caracteriza por la aparición de tumores benignos en distintos órganos que, ocasionalmente, pueden malignizarse. Se describen cuatro tipos de neurofibromatosis; la más frecuente es la de tipo 1, que se produce por mutaciones en el gen NF1, inhibiendo la neurofibromina, y en un pequeño porcentaje de casos por microdeleción 17q11. En el 50% de los casos es autosómica dominante y la penetrancia es del 100%. Su prevalencia es de 1/3000 nacidos vivos y afecta por igual a ambos sexos. El diagnóstico se efectúa por la presencia de signos característicos y puede corroborarse por medio de estudios genéticos. Suele manifestarse en la infancia y comprometer la piel, con formación de múltiples neurofibromas, gliomas de la vía óptica, hamartomas del iris, malformaciones óseas, hipertensión arterial, alteraciones vasculares, tumores intracraneales y de las vainas de nervios periféricos, convulsiones, hidrocefalia, déficit cognitivo y dificultades del aprendizaje. La enfermedad vascular es una complicación rara que suele ser asintomática, puede afectar los vasos que van desde la aorta proximal hasta las arteriolas pequeñas, incluyendo estenosis arteriales, aneurismas y malformaciones arteriovenosas. El pronóstico suele ser bueno; las causas de mortalidad temprana son las neoplasias y las vasculopatías. Presentamos el caso de un paciente con diagnóstico de neurofibromatosis tipo 1 que presentó ruptura de seudoaneurisma dependiente de la arteria temporal izquierda, con fístula con drenaje a la vena facial superficial, que se resolvió favorablemente mediante tratamiento endovascular

Paquimeningitis hipertrófica posinfecciosa: presentación de caso clínico / Post-infection hypertrophic pachymeningitis: a clinical case report

La paquimeningitis hipertrófica es una entidad infrecuente que puede ser idiopática o secundaria, y dado que incluso un diagnóstico acertado y un correcto tratamiento pueden dejar secuelas neurológicas graves o, incluso, producir la muerte, presentamos este caso en el que consideramos que la causa fue una meningitis que no recibió tratamiento adecuado al inicio de los síntomas y que tuvo una respuesta satisfactoria al tratamiento con corticoides, inicialmente en altas dosis.

Assessment of Ablative Fractional CO2 Laser and Er:YAG Laser to Treat Hypertrophic Scars in a Red Duroc Pig Model.

Hypertrophic scarring is a fibroproliferative process that occurs following a third-degree dermal burn injury, producing significant morbidity due to persistent pain, itching, cosmetic disfigurement, and loss of function due to contractures. Ablative fractional lasers have emerged clinically as a fundamental or standard therapeutic modality for hypertrophic burn scars. Yet the examination of their histopathological and biochemical mechanisms of tissue remodeling and comparison among different laser types has been lacking. In addition, deficiency of a relevant animal model limits our ability to gain a better understanding of hypertrophic scar pathophysiology. To evaluate the effect of ablative fractional lasers on hypertrophic third-degree burn scars, we have developed an in vivo Red Duroc porcine model. Third-degree burn wounds were created on the backs of animals, and burn scars were allowed to develop for 70 days before treatment. Scars received treatment with either CO2 or erbium: yttrium aluminum garnet (YAG) ablative fractional lasers. Here, we describe the effect of both lasers on hypertrophic third-degree burn scars in Red Duroc pigs. In this report, we found that Er:YAG has improved outcomes versus fractional CO2. Molecular changes noted in the areas of dermal remodeling indicated that matrix metalloproteinase 2, matrix metalloproteinase 9, and Decorin may play a role in this dermal remodeling and account for the enhanced effect of the Er:YAG laser. We have demonstrated that ablative fractional laser treatment of burn scars can lead to favorable clinical, histological, and molecular changes. This study provides support that hypertrophic third-degree burn scars can be modified by fractional laser treatment.

Mesenchymal Stem Cell Exosomes Induce Proliferation and Migration of Normal and Chronic Wound Fibroblasts, and Enhance Angiogenesis In Vitro.

Although chronic wounds are common and continue to be a major cause of morbidity and mortality, treatments for these conditions are lacking and often ineffective. A large body of evidence exists demonstrating the therapeutic potential of mesenchymal stem cells (MSCs) for repair and regeneration of damaged tissue, including acceleration of cutaneous wound healing. However, the exact mechanisms of wound healing mediated by MSCs are unclear. In this study, we examined the role of MSC exosomes in wound healing. We found that MSC exosomes ranged from 30 to 100-nm in diameter and internalization of MSC exosomes resulted in a dose-dependent enhancement of proliferation and migration of fibroblasts derived from normal donors and chronic wound patients. Uptake of MSC exosomes by human umbilical vein endothelial cells also resulted in dose-dependent increases of tube formation by endothelial cells. MSC exosomes were found to activate several signaling pathways important in wound healing (Akt, ERK, and STAT3) and induce the expression of a number of growth factors [hepatocyte growth factor (HGF), insulin-like growth factor-1 (IGF1), nerve growth factor (NGF), and stromal-derived growth factor-1 (SDF1)]. These findings represent a promising opportunity to gain insight into how MSCs may mediate wound healing.

Role of whole bone marrow, whole bone marrow cultured cells, and mesenchymal stem cells in chronic wound healing.

INTRODUCTION: Recent evidence has shown that bone marrow cells play critical roles during the inflammatory, proliferative and remodeling phases of cutaneous wound healing. Among the bone marrow cells delivered to wounds are stem cells, which can differentiate into multiple tissue-forming cell lineages to effect, healing. Gaining insight into which lineages are most important in accelerating wound healing would be quite valuable in designing therapeutic approaches for difficult to heal wounds. METHODS: In this report we compared the effect of different bone marrow preparations on established in vitro wound healing assays. The preparations examined were whole bone marrow (WBM), whole bone marrow (long term initiating/hematopoietic based) cultured cells (BMC), and bone marrow derived mesenchymal stem cells (BM-MSC). We also applied these bone marrow preparations in two murine models of radiation induced delayed wound healing to determine which had a greater effect on healing. RESULTS: Angiogenesis assays demonstrated that tube formation was stimulated by both WBM and BMC, with WBM having the greatest effect. Scratch wound assays showed higher fibroblast migration at 24, 48, and 72 hours in presence of WBM as compared to BM-MSC. WBM also appeared to stimulate a greater healing response than BMC and BM-MSC in a radiation induced delayed wound healing animal model. CONCLUSIONS: These studies promise to help elucidate the role of stem cells during repair of chronic wounds and reveal which cells present in bone marrow might contribute most to the wound healing process.

Percutaneous bone marrow transplantation using fractional ablative Erbium:YAG laser.

Topical application of therapeutic agents has been a mainstay in Dermatology for the treatment of skin disorders but is not commonly used for systemic delivery. For a topically applied agent to reach distant body sites it must first overcome the barrier function of the skin and then penetrate into deeper structures before reaching the systemic circulation. This has limited the use of topically applied agents to those having specific charge, solubility and size restrictions. Pretreatment of the skin with ablative fractional laser appears to enhance the uptake of some topically applied drugs but the ability to effectively deliver agents to distant sites is largely unproven. In this report we used a fractional ablative Erb:YAG (Erbium/Yttrium Aluminum Garnet) laser to facilitate the transfer of bone marrow stem cells through the skin in a murine bone marrow transplant model. Chimerism could be detected in the peripheral blood of recipient C57BL/6 mice that were pretreated with ablative fractional laser and had topically applied enhanced green fluorescent protein (GFP) labeled bone marrow cells from syngeneic donor transgenic mice. This study indicates that fractional laser can be used to deliver stem cells through the skin and remain functionally intact.

Stimulation of skin and wound fibroblast migration by mesenchymal stem cells derived from normal donors and chronic wound patients.

Chronic wounds continue to be a major cause of morbidity for patients and an economic burden on the health care system. Novel therapeutic approaches to improved wound healing will need, however, to address cellular changes induced by a number of systemic comorbidities seen in chronic wound patients, such as diabetes, chronic renal failure, and arterial or venous insufficiency. These effects likely include impaired inflammatory cell migration, reduced growth factor production, and poor tissue remodeling. The multifunctional properties of bone marrow-derived mesenchymal stem cells (MSCs), including their ability to differentiate into various cell types and capacity to secrete factors important in accelerating healing of cutaneous wounds, have made MSCs a promising agent for tissue repair and regeneration. In this study we have used an in vitro scratch assay procedure incorporating labeled MSCs and fibroblasts derived from normal donors and chronic wound patients in order to characterize the induction of mobilization when these cells are mixed. A modified Boyden chamber assay was also used to examine the effect of soluble factors on fibroblast migration. These studies suggest that MSCs play a role in skin wound closure by affecting dermal fibroblast migration in a dose-dependent manner. Deficiencies were noted, however, in chronic wound patient fibroblasts and MSCs as compared with those derived from normal donors. These findings provide a foundation to develop therapies targeted specifically to the use of bone marrow-derived MSCs in wound healing and may provide insight into why some wounds do not heal.