Photoinitiated Transient Self-Assembly in a Catalytically Driven Chemical Reaction Cycle.

Chemically fueled chemical reaction networks (CRNs) are essential in controlling dissipative self-assembly. A key challenge in the field is to store chemical fuel-precursors or "pre-fuels" in the system that are converted into activating or deactivating fuels in a catalytically controlled CRN. In addition, real-time control over catalysis in a CRN by light is highly desirable, but so far not yet achieved. Here we show a catalytically driven CRN that is photoinitiated with 450 nm light, producing activated monomers that go on to perform transient self-assembly. Monomer activation proceeds via photoredox catalysis, converting the monomer alcohol groups into the corresponding aldehydes that self-assemble into large supramolecular fibers. Monomer deactivation is achieved by organometallic catalysis that relies on pre-fuel hydrolysis to release formate (i.e. the deactivating fuel). Additionally, irradiation with 305 nm light accelerates the release of formate by photo-uncaging the pre-fuel, leading to a factor of ca. 2 faster deactivation of the monomer. Overall, we show transient self-assembly upon visible light photoactivation, and tunable life-times by ultraviolet light.

Evaluation of the reproducibility of the Tronzo classification for intertrochanteric fractures of the femur in an orthopedic service of a Hospital in Ibagué, Colombia / Evaluación de la reproducibilidad de la clasificación de Tronzo para fracturas intertrocantéricas de fémur en un servicio de ortopedia de un Hospital de Ibague, Colombia

Introduction: Hip fractures are a pathology of traumatic origin that generates a high impact on public health. The objective is to evaluate the interobserver reproducibility of the Tronzo classification for intertrochanteric fractures. Methods: Observational, analytical and retrospective study carried out in Ibagué - Colombia, 48 hip radiographs were analyzed, classified by 10 observed among specialists and training personnel, using the Tronzo classification. Interobserver reproducibility is assessed using the kappa concordance coefficient. Results: Among all those observed in the study, there is greater agreement in the identification of intertrochanteric fractures of lesser and greater severity (Tronzo I and V), the main exponents of this agreement are the most experienced staff, the staff in training, with intermediate experience they agree when identifying those of intermediate severity and for those with less experience the concordance becomes evident when evaluating the intermediate grades. Conclusion: The concordance increases with the experience for the identification of the types with high complexity. This classification is not suitable for clinical practice, another system is necessary for this type of fracture in clinical conduct.

Introducción: Las fracturas de cadera son una patología de origen traumático que genera un alto impacto en la salud pública. El objetivo es evaluar la reproducibilidad interobservador de la clasificación de Tronzo para fracturas intertrocantéricas. Métodos: Estudio observacional, analítico y retrospectivo realizado en Ibagué ­ Colombia, se analizaron 48 radiografías de cadera, clasificadas por 10 observado entre especialistas y personal en formación, utilizando la clasificación de Tronzo. La reproducibilidad interobservador se evalúa mediante el coeficiente de concordancia kappa. Resultados: Entre todos los observados del estudio existe mayor acuerdo en la identificación de fracturas intertrocantéricas de menor y mayor gravedad (Tronzo I y V), los principales exponentes de este acuerdo son el personal de mayor experiencia, el personal en formación, con experiencia intermedia están de acuerdo al identificar a los de gravedad intermedia y para los que tienen menos experiencia la concordancia se hace evidente a la hora de evaluar los grados intermedios. Conclusión: La concordancia aumenta con la experiencia para la identificación de los tipos con alta complejidad. No es adecuado para la práctica clínica esta clasificación, es necesario otro sistema para este tipo de fracturas en las conductas clínicas.

Burden of skin cancer in Colombia.

BACKGROUND: Levels of incidence and mortality of skin cancer in Colombia and Latin America are largely unknown. OBJECTIVES: Present the available information from official and gray literature and governmental databases to grasp the magnitude and characteristics of skin cancer in Colombia (middle-income Latin American country). METHODS: Narrative review based on a literature search (2005-2020), gray literature and cancer registry and governmental warehouse data, calculation of proportions and age-standardized incidence (ASIR) and mortality rates (ASMR), expressed per 100,000 person-years. RESULTS: ASIR of cutaneous melanoma in Colombia is around 3, corresponding ASMR between 0.7 and 0.8. Distinctive features are the high proportion and rates for acral melanomas, and the advanced stage at diagnosis in the general population but not in private clinics. For non-melanoma skin cancer, ASIR is at least around 35-40, ASMR 0.8. CONCLUSIONS: Among the wealthy Colombians, melanoma features are similar to those of high incidence countries (but of lower magnitude), whereas the majority of the population present distinct features with a much higher proportion of acral melanomas, very late stages at diagnosis, and poor prognosis. More advanced melanomas seem to have a relation with lower socioeconomic status. Non-melanoma skin cancer is common, with very high mortality rates at levels even above those of predominantly fair-skinned populations, implying high fatality rates for non-melanoma skin cancers. This could indicate a late diagnosis or difficulties in access to treatment, illustrating the need for primary and secondary prevention to reduce the burden of disease and improve the prognosis of this common cancer.

Chemically Fueled Self-Sorted Hydrogels.

Narcissistic self-sorting in supramolecular assemblies can help to construct materials with more complex hierarchies. Whereas controlled changes in pH or temperature have been used to this extent for two-component self-sorted gels, here we show that a chemically fueled approach can provide three-component materials with high precision. The latter materials have interesting mechanical properties, such as enhanced or suppressed stiffness, and intricate multistep gelation kinetics. In addition, we show that we can achieve supramolecular templating, where pre-existing supramolecular fibers first act as templates for growth of a second gelator, after which they can selectively be removed.

Melanoma Lentiginoso Acral Revisión Narrativa de uno de los Melanomas más Frecuentes en América Latina / Acral lentiginous melanoma: Review of one of the most frequent melanomas in Latin America

Resumen El melanoma es el cáncer de piel con mayor tasa de mortalidad a nivel mundial. Se han descrito 4 subtipos principales de melanoma cutáneo: el melanoma de extensión superficial, el melanoma nodular, el léntigo maligno y el melanoma lentiginoso acral. Existen diferencias raciales y geográficas en la distribución y frecuencia de estos subtipos. En caucásicos, el riesgo es mayor para melanomas de piel expuesta a radiación UV, ya sea de forma crónica o intermitente. En contraste, en asiáticos, afroamericanos e hispanos, la tendencia es mayor en sitios anatómicos no expuestos (palmas y plantas), encabezando el melanoma lentiginoso acral en una proporción mayor. Usualmente, este melanoma se diagnostica de manera tardía y en estadios avanzados, por cual se asocia con un peor pronóstico. La presente revisión pretende brindar una visión general sobre el conocimiento del melanoma lentiginoso acral, describiendo aspectos como la epidemiología, los factores de riesgo asociados, las características genéticas y los factores pronósticos.

Abstract Melanoma is the cutaneous cancer with the highest mortality worldwide. Four main subtypes of cutaneous melanoma have been described: superficial spreading melanoma, nodular melanoma, lentigo maligna melanoma, and acral lentiginous melanoma. There are racial and geographical differences in the distribution and frequency of these subtypes. In Caucasians, the risk is higher to develop melanoma on skin exposed to UV radiation, either chronically or intermittently. In contrast, in Asians, African Americans, and Hispanics, there is a greater tendency towards unexposed anatomical sites (palms and soles), which is called acral lentiginous melanoma. This melanoma is usually diagnosed in advanced stages, and therefore has a worse prognosis. This review aims to provide an update on what is known about acral lentiginous melanoma, mainly describing its epidemiology, risk factors associated with genetic characteristics, and prognosis.

An Immunoinformatics Approach for SARS-CoV-2 in Latam Populations and Multi-Epitope Vaccine Candidate Directed towards the World's Population.

The coronavirus pandemic is a major public health crisis affecting global health systems with dire socioeconomic consequences, especially in vulnerable regions such as Latin America (LATAM). There is an urgent need for a vaccine to help control contagion, reduce mortality and alleviate social costs. In this study, we propose a rational multi-epitope candidate vaccine against SARS-CoV-2. Using bioinformatics, we constructed a library of potential vaccine peptides, based on the affinity of the most common major human histocompatibility complex (HLA) I and II molecules in the LATAM population to predict immunological complexes among antigenic, non-toxic and non-allergenic peptides extracted from the conserved regions of 92 proteomes. Although HLA-C, had the greatest antigenic peptide capacity from SARS-CoV-2, HLA-B and HLA-A, could be more relevant based on COVID-19 risk of infection in LATAM countries. We also used three-dimensional structures of SARS-CoV-2 proteins to identify potential regions for antibody production. The best HLA-I and II predictions (with increased coverage in common alleles and regions evoking B lymphocyte responses) were grouped into an optimized final multi-epitope construct containing the adjuvants Beta defensin-3, TpD, and PADRE, which are recognized for invoking a safe and specific immune response. Finally, we used Molecular Dynamics to identify the multi-epitope construct which may be a stable target for TLR-4/MD-2. This would prove to be safe and provide the physicochemical requirements for conducting experimental tests around the world.

Eccrine Porocarcinoma with Zosteriform Metastasis.

Eccrine porocarcinoma is a rare malignant tumor that develops in the eccrine glands, appearing as a primary tumor, or by malignant transformation of an eccrine poroma. It is a carcinoma with high metastatic and recurrent potential; it has the same incidence in both sexes, and mainly affects the elderly. Its diagnosis, rather than clinical, is histological, and due to the rarity of the disease, it is a pathological challenge. There are no standardized treatment guidelines for porocarcinoma, but surgical resection with tumor-free margins is considered the basis of treatment, in addition to sentinel node biopsy under risk factors and individualization of each patient. For the metastatic form, chemotherapy and radiotherapy are the treatment of choice. Herein, we present the case of a man with eccrine porocarcinoma with extensive zosteriform skin metastasis and lymph node involvement, treated with chemotherapy and concomitant radiotherapy.

Dermatofibrosarcoma protuberans / Dermatofibrosarcoma protuberans

Resumen El dermatofibrosarcoma protuberans (DFSP) es un sarcoma cutáneo de baja incidencia y lento crecimiento que afecta principalmente a personas de entre 20 a 39 años y es más frecuente en afrodescendientes. La localización anatómica más común es el tronco, seguido de las extremidades superiores. La etiología no está clara, pero la mayoría de los casos presentan rearreglos genéticos que involucran los genes COL1A1 y PDGFB. El riesgo de metástasis es bajo, pero tiene tendencia a la recurrencia local, especialmente en: los tumores resecados con márgenes insuficientes, los tumores profundos y los tumores que presentan cambio fibrosarcomatoso. La primera línea de manejo para la enfermedad local es la cirugía con la resección local amplia o la cirugía micrográfica de Mohs (CMM), que ha mostrado recurrencias consistentemente bajas. La radioterapia se ha usado para tumores irresecables o como adyuvancia. En los casos de enfermedad metastásica el manejo de elección es el imatinib.

Abstract Dermatofibrosarcoma protuberans (DFSP) is a low incidence and slow growing cutaneous sarcoma that mainly affects individuals between 20 and 39 years old and is more frequent in black race. The most common anatomical site is the trunk, followed by the upper extremities. The etiology is unclear, but the most cases present genetic rearrangements involving the COL1A1 and PDGFB genes. The risk of metastasis is low, but it tends to local recurrence, especially when section margins were insufficient, in deep tumors or those with fibrosarcomatous change. The first line of treatment for local disease is surgery; wide local resection or Mohs micrographic surgery (MMS). The latter technique has shown consistently low recurrence rate. Radiotherapy has been used for unresectable cases or as adjuvant therapy. Imatinib is useful for metastatic disease.

Epidemiological profile of primary cutaneous melanoma over a 15-year period at a private skin cancer center in Colombia.

OBJECTIVE: To describe clinical, histopathological and treatment characteristics of melanoma in a private institution of Bogotá, Colombia, and to identify differences regarding sex and age. MATERIALS AND METHODS: Observational, retrospective study. 415 medical records between January 1999 and May 2014 were analyzed. RESULTS: Out of 415 patients, 244 (58.8%) were females and 171 (41.2%) were males with a mean age of 56.1 ±16.2 SD. Superficial spreading melanoma (SSMM) was the main subtype (n=175, 42.7%). Breslow's thickness ≤1mm was predominant, while phototypes II and III were more frequent (n=87, 69.6%). Melanoma was predominantly localized on the head in men (n=83, 50.3%) and in the lower limbs in women (n=89, 36.8%), with a higher frequency of SSMM pattern among patients aged ≤65. Lentigo maligna (LM) was more frequent in patients aged >65 (p<0.001), with a higher number of ulcerated melanomas (p=0.046). CONCLUSIONS: A predominance of thin SSMM and fair skin phototypes were found, unlike previous reports that showed acral lentiginous melanoma (ALM) as predominant, which may be caused by local variations related to mixed ethnicity.

Epidemiological profile of primary cutaneous melanoma over a 15-year period at a private skin cancer center in Colombia / Perfil epidemiológico del melanoma cutáneo primario durante 15 años en un centro privado de cáncer de piel en Colombia

ABSTRACT Objective To describe clinical, histopathological and treatment characteristics of melanoma in a private institution of Bogotá, Colombia, and to identify differences regarding sex and age. Materials and Methods Observational, retrospective study. 415 medical records between January 1999 and May 2014 were analyzed. Results Out of 415 patients, 244 (58.8%) were females and 171 (41.2%) were males with a mean age of 56.1 ±16.2 SD. Superficial spreading melanoma (SSMM) was the main subtype (n=175, 42.7%). Breslow's thickness ≤1mm was predominant, while phototypes II and III were more frequent (n=87, 69.6%). Melanoma was predominantly localized on the head in men (n=83, 50.3%) and in the lower limbs in women (n=89, 36.8%), with a higher frequency of SSMM pattern among patients aged ≤65. Lentigo maligna (LM) was more frequent in patients aged >65 (p<0.001), with a higher number of ulcerated melanomas (p=0.046). Conclusions A predominance of thin SSMM and fair skin phototypes were found, unlike previous reports that showed acral lentiginous melanoma (ALM) as predominant, which may be caused by local variations related to mixed ethnicity.(AU)

RESUMEN Objetivo Describir las características clínicas, histopatológicas y de tratamiento del melanoma de una institución privada en Bogotá, Colombia, e identificar las diferencias con respecto al sexo y la edad. Métodos Estudio observacional retrospectivo. Se evaluaron 415 registros médicos entre enero de 1999 y mayo de 2014 Resultados Se incluyeron 415 pacientes, 244 (58,8%) mujeres, 171 (41,2%) mujeres con una edad media de 56,1 ± 16,2 DE. El melanoma de extensión superficial fue el subtipo principal (n=175, 42,7%). El grosor del Breslow ≤1mm fue predominante. Los fototipos II y III fueron los más frecuentes (n=87, 69,6%). Los melanomas estuvieron predominantemente localizados en la cabeza en los hombres (n=83, 50,3%) y las extremidades inferiores en las mujeres (n=89, 36,8%), con una frecuencia más alta para el patrón de extensión superficial (SSMM) entre los pacientes con edad ≤65 años y lentigo maligno (LM) en pacientes ancianos mayores de 65 años (p<0,001) con un mayor número de melanomas ulcerados para este último grupo (p=0,046). Conclusiones Se encontró un predominio de SSMM delgados y fototipos de piel clara, a diferencia de los reportes previos que mostraban al melanoma lentiginoso acral (ALM) como preponderante. Lo que podría deberse a las variaciones locales relacionadas con el origen étnico mixto.(AU)

Dermatofibrosarcoma Protuberans.

OPINION STATEMENT: Dermatofibrosarcoma protuberans (DFSP) is a slow growing tumor with a very low metastatic potential but with significant subclinical extension and great capacity for local destruction. Thus, the first surgeon approached with such challenging tumor must attempt to cure the patient with a method that spares healthy tissue and ensures an optimal oncological, functional, and esthetic result. The treatment of DFSP often requires a multidisciplinary approach. Depending on location, dermatologic surgeons, surgical oncologists, head and neck surgeons, neurosurgeons, plastic surgeons, and occasionally medical oncologists may be involved with the management. Mohs micrographic surgery (MMS) is the preferred method when available. In our institution, most of the DFSP cases are often advanced cases; thus, dermatologic surgeons obtain clear margins peripherally and other surgical specialties assist with resection of the fascia and any critical deeper structures. When MMS is not available, wide local excision (at least 2- to 3-cm margins of resection) with exhaustive pathologic assessment of margin status is recommended, and it is best to confirm tumor extirpation prior to any reconstruction. Subclinical extension of the tumor could be related to the size; how long it has been growing or histological markers that are unknown right now. No clinical trials comparing MMS vs WLE are available, and further research should be focused on these subjects as well as the use of imatinib and other targeted therapies for recurrent and metastatic tumors and for neoadjuvant treatment.

Criocirugía en el manejo del carcinoma basocelular de bajo riesgo y evaluación de la recidiva tumoral / Tumour recurrence after cryosurgery in the treatment of low risk basal cell Basal cell carcinoma

Objetivos: Describir las características demográficas, clínicas e histológicas de pacientes con carcinoma basocelular de bajo riesgo llevados a criocirugía y la respuesta al tratamiento en términos de recidiva o curación tumoral. Métodos: Se realizó un estudio tipo serie de casos retrospectivo, los sujetos fueron pacientes con carcinoma basocelular de bajo riesgo tratados con criocirugía en el servicio de dermatología del Instituto Nacional de Cancerología de Colombia (INC) entre enero de 2009 y agosto de 2012, con seguimiento clínico entre 1,7 y 64,3 meses. Los pacientes se sometieron a un procedimiento estandarizado que implicó: marcación dermatoscópica de los márgenes, saucerización en caso de lesión evidente y dos ciclos de congelación-descongelación. Se evaluó la función de supervivencia a la recidiva utilizando el método de Kaplan-Meier. Resultados: Se analizaron los datos de 108 pacientes que presentaron un total de 156 tumores; la curación se diagnosticó en el 98,7% de los casos. Se presentó recidiva tumoral en dos pacientes de sexo masculino a los 17 y 22 meses, ambas localizadas en la zona H de la cabeza. Conclusión: Los datos de curación clínica fueron similares a los reportados en la literatura, en el presente estudio se evidenció que la criocirugía en carcinoma basocelular de bajo riesgo tuvo cifras de curación equivalentes a las descritas en resección quirúrgica.

Objectives: The objective of this study is to describe the demographic, clinical and histological characteristics of the population studied, and to determine the recurrence or cure rate of low-risk basal cell carcinoma treated with cryosurgery. Methods: A retrospective study was conducted on a case series of patients with low-risk basal cell carcinoma treated with cryosurgery between January 2009 and August 2012, in the Dermatology Department of the National Institute of Cancerology (Bogotá, Colombia). The clinical follow-up ranged between 1.7 months and 64.3 months. Each tumour was treated with a standardised cryosurgery procedure performed by the same operator. In each case, the tumour margins were delineated with careful dermoscopic evaluation. Saucerisation was performed in case of clinical visible tumour. Two freeze-thaw spray cycles were performed. Progression free survival was measured using the Kaplan -Meier method. Results: In the analysis of 108 patients with 156 tumours, there was a clinical cure-rate of 98.7% of tumours. Two tumour recurrences located in the H area were detected at 17 months and 22 months after treatment in two male patients. Conclusion: Data from clinical cure-rate reported in the literature were similar to our study. In this group of patients, it was shown that in low-risk basal cell carcinoma treated with cryosurgery, the cure-rates were equivalent to those described in the literature with surgical resection.

Cation Exchange in Dynamic 3D Porous Magnets: Improvement of the Physical Properties.

We report two novel three-dimensional porous coordination polymers (PCPs) of formulas Li4{Mn4[Cu2(Me3mpba)2]3}·68H2O (2) and K4{Mn4[Cu2(Me3mpba)2]3}·69H2O (3) obtained-via alkali cation exchange in a single-crystal to single-crystal process-from the earlier reported anionic manganese(II)-copper(II) PCP of formula Na4{Mn4[Cu2(Me3mpba)2]3}·60H2O (1) [Me3mpba(4-) = N,N'-2,4,6-trimethyl-1,3-phenylenebis(oxamate)]. This postsynthetic process succeeds where the direct synthesis in solution from the corresponding building blocks fails and affords significantly more robust PCPs with enhanced magnetic properties [long-range 3D magnetic ordering temperatures for the dehydrated phases (1'-3') of 2.0 (1'), 12.0 (2'), and 20.0 K (3')]. Changes in the adsorptive properties upon postsynthetic exchange suggest that the nature, electrostatic properties, mobility, and location of the cations within the framework are crucial for the enhanced structural stability. Overall, these results further confirm the potential of postsynthetic methods (including cation exchange) to obtain PCPs with novel or enhanced physical properties while maintaining unaltered their open-framework structures.

Dicopper(II) anthraquinophanes as multielectron reservoirs for oxidation and reduction: a joint experimental and theoretical study.

Two new dinuclear copper(II) metallacyclophanes with 1,4-disubstituted 9,10-anthraquinonebis(oxamate) bridging ligands are reported that can reversibly take and release electrons at the redox-active ligand and metal sites, respectively, to give the corresponding mono- and bis(semiquinonate and/or catecholate) Cu(II)2 species and mixed-valent Cu(II)/Cu(III) and high-valent Cu(III)2 ones. Density functional calculations allow us to give further insights on the dual ligand- and metal-based character of the redox processes in this novel family of antiferromagnetically coupled di- copper(II) anthraquinophanes. This unique ability for charge storage could be the basis for the development of new kinds of molecular spintronic devices, referred to as molecular magnetic capacitors (MMCs).

Características del melanoma cutáneo primario en el Instituto Nacional de Cancerología 2006-2010 / Characteristics of primary cutaneous melanoma in the Colombian National Cancerology Institute 2006-2010

Objetivos: Describir las principales características del melanoma cutáneo en el Instituto Nacional de Cancerología, centro de referencia del cáncer, en Bogotá, Colombia. Materiales y métodos: Estudio descriptivo, retrospectivo, de las características demográficas, clínicas e histológicas de los pacientes con diagnóstico de melanoma cutáneo primario, en el Instituto Nacional de Cancerología entre 2006 y 2010. Resultados: Se incluyeron un total de 599 pacientes, de los cuales el 57,4% eran mujeres (n = 344) y el 42,6% hombres (n = 255). La edad media de diagnóstico fue de 60,8 años. La mayoría de los casos fueron procedentes de Bogotá, con el 56,3% (n = 329). Fue más frecuente el área urbana como sitio de residencia habitual (n = 500). La media de frecuencia anual fue de 115 casos nuevos por año. La localización más frecuente fue acral, con el 42,2% (n = 253), seguido de cabeza y cuello (n = 186). Concordando con la localización, el subtipo más frecuente fue el melanoma lentiginoso acral, con el 43,7% (n = 262), seguido por el lentigo maligno, con el 24% (n = 144). En cuanto a la profundidad, se observó una frecuencia igual de melanomas in situ y melanomas con Breslow > 4 mm, ambos con el 19% de los casos. Se encontró que la mayoría de los lentigos malignos, el 75% (n = 108), fueron in situ o con un Breslow ≤ 1 mm; por el contrario, los lentiginosos acrales y los nodulares tuvieron un Breslow > 4 mm con mayor frecuencia (con el 26,3%, n = 69, y el 45,4%, n = 10, respectivamente). El estadio más frecuente fue el III, con el 26,2% de los casos (n = 157). Conclusiones: Se evidenció un mayor porcentaje de melanomas en mujeres y mayor frecuencia de melanomas acrales. Un número importante de pacientes se ubicaron en estado avanzado, por lo que se requieren mayores acciones para la detección temprana del melanoma.

Objectives: To describe the main characteristics of cutaneous melanoma in the National Cancerology Institute, a cancer reference center in Bogota, Colombia. Materials and methods: A descriptive, retrospective study was conducted on the demographic, clinical and histological characteristics of patients diagnosed with primary cutaneous melanoma in the National Cancerology Institute between 2006 and 2010. Results: A total of 599 patients were included, of whom 57.4% were females (n= 344) and 42.6% males (n=255). The mean age at diagnosis was 60.8 years. The majority of cases, 56.3% (n=329), were from Bogota. It was also the most common urban area where the patients had their usual residence (n=500). The mean annual frequency was 115 new cases per year. The most frequent location was acral, with 42.2% (n=253), followed by head and neck (n=186). In accordance with the location, the most common sub-type was acral lentiginous melanoma, with con 43.7% (n=262), followed by lentigo maligna, with 24% (n=144). As regards the depth, a similar frequency was observed for melanomas in situ and melanomas with Breslow >4 mm, both with 19% of the cases. It was found that the large majority of the lentigo maligna, 75% (n=108) were in situ or with a Breslow ≤1 mm. On the other hand, acral lentiginous and nodular melanomas had a higher frequency of Breslow >4 mm (with 26.3% n=69 and 45.4% n=10, respectively). Stage III was the most common stage, with 26.2% (n=157) of the cases. Conclusions: A higher percentage of melanomas were observed in women, as well as a higher frequency of acral melanomas. A signifi cant number of patients were in an advanced stage, thus greater action is required for the early detection of melanoma.

Tumor pilar proliferante maligno en cuero cabelludo / Malignant proliferating pilar tumor of the scalp

El tumor pilar proliferante maligno es una neoplasia rara que puede confundirse con un carcinoma escamocelular y está caracterizado a la clínica por localizarse en áreas diferentes al cuero cabelludo, crecimiento rápido e infi ltrativo, un diámetro mayor a 5 centímetros y, en algunas instancias, reportes de metástasis. Presentamos el caso de una paciente de sexo femenino, con diagnóstico de tumor pilar proliferante maligno localizado en el cuero cabelludo.

The malignant proliferating pilar tumor is a rare neoplasm that may be confused with squamous cell carcinoma, and is characterized by the clinical location in areas other than the scalp, rapid and infiltrative growth, a diameter greater than 5 centimeters, and in some instances, reports of metastasis. We report the case of a female patient, diagnosed with malignant proliferating pilar tumor, located in the scalp.

New family of thiocyanate-bridged Re(IV)-SCN-M(II) (M = Ni, Co, Fe, and Mn) heterobimetallic compounds: synthesis, crystal structure, and magnetic properties.

The heterobimetallic complexes of formula [(Me(2)phen)(2)M(µ-NCS)Re(NCS)(5)]·CH(3)CN [Me(2)phen = 2,9-dimethyl-1,10-phenanthroline and M = Ni (1), Co (2), Fe (3), and Mn (4)] have been prepared, and their crystal structures have been determined by X-ray diffraction on single crystals. Compounds 1-4 crystallize in the monoclinic C2/c space group, and their structure consists of neutral [(Me(2)phen)(2)M(µ-NCS)Re(NCS)(5)] heterodinuclear units with a Re-SCN-M bridge. Each Re(IV) ion in this series is six-coordinated with one sulfur and five nitrogen atoms from six thiocyanate groups building a somewhat distorted octahedral environment, whereas the M(II) metal ions are five-coordinated with four nitrogen atoms from two bidentate Me(2)phen molecules and a nitrogen atom from the bridging thiocyanate describing distorted trigonal bipyramidal surroundings. The values of the Re···M separation through the thiocyanate bridge in 1-4 vary in the range 5.903(1)-6.117(3) Å. The magnetic properties of 1-4 as well as those of the parent mononuclear Re(IV) compounds (NBu(4))(2)[Re(NCS)(6)] (A1) (NBu(4)(+) = tetra-n-butylammonium cation) and [Zn(NO(3))(Me(2)phen)(2)](2)[Re(NCS)(5)(SCN)] (A2) were investigated in the temperature range 1.9-300 K. Weak antiferromagnetic interactions between the Re(IV) and M(II) ions across the bridging thiocyanate were found in 1-4 [J = -4.3 (1), -2.4 (2), -1.8 (3), and -1.2 cm(-1) (4), the Hamiltonian being defined as H = -JS(Re)·S(M)]. The magnetic behavior of A2 is that of a magnetically diluted Re(IV) complex with a large and positive value of the zero-field splitting for the ground level (D(Re) = +37.0 cm(-1)). In the case of A1, although its magnetic behavior is similar to that of A2 in the high-temperature range (D(Re) being +19.0 cm(-1)), it exhibits a weak ferromagnetism below 3.0 K with a canting angle of 1.3°.

Experiencia de linfomas cutáneos entre enero de 1995 y abril de 2008 en el Instituto Nacional de Cancerología / Experience with cutaneous lymphomas between January 1995 and April 2008 at the National Cancer Institute

Objetivos: Describir los diferentes linfomas cutáneos conforme a la clasificación WHO- EORTC, observados en el Instituto Nacional de Cancerología (INC) entre el 1° de enero de 1995 y abril de 2008. Métodos: Estudio retrospectivo, descriptivo, donde se incluyó a los pacientes con diagnóstico de linfoma cutáneo en el INC desde enero de 1995 hasta abril de 2008. La ubicación de las historias clínicas se realizó utilizando la base de datos del Departamento de Patología. El análisis estadístico se realizó mediante el programa Epi info 2008. Resultados: Se revisaron 252 historias y se incluyó a 160 pacientes en el estudio: 139 linfomas T (87%) y 21 linfomas B (13%). El linfoma más común fue la micosis fungoide (63% de los casos). Dentro de las variantes descritas de micosis fungoide (MF) llamó la atención la frecuencia de MF hipopigmentadas (13%). El grupo de enfermedades linfoproliferativas CD30+ fue el segundo en frecuencia dentro de los linfomas T. En el grupo de linfomas B los linfomas indolentes de excelente pronóstico se presentaron en un 5% de los casos. Conclusiones: Los linfomas cutáneos primarios son tumores raros. Predominan los linfomas de células T sobre los B. La mayoría de los casos son linfomas de bajo grado, y deben tratarse con terapias dirigidas a la piel. Dentro de cada categoría existen linfomas que van a progresar y comprometer órganos internos.

Objectives: To describe different cutaneous lymphomas in accordance with WHO-EORTC classification under observation at the National Cancer Institute (NCI) between January 1, 1995 and April, 2008. Methods: A descriptive, retrospective study was carried out which included patients diagnosed with cutaneous lymphoma at the NCI from January 1995 until April 2008. Clinical cases were taken from Pathology Department data base. Statistical analysis was performed with Epi 2008 info program. Results: A total of 252 case histories were reviewed, and 160 patients were included in the study: 139 T-cell lymphomas (87%) and 21 B-cell lymphomas (13%). The most common (63% of cases) was mycosis fungoides (MF). Among the variations of MF described, the frequency of hypopigmented MF (13%) stood out. The lymphoproliferative CD30+ disease group was the second most frequent among T-cell lymphomas. In the B-cell lymphoma group, the indolent lymphomas with excellent prognosis made up 5% of cases. Conclusions: Primary cutaneous lymphomas are rare tumors. T-cell lymphomas predominate over B-cell. Most cases are low grade lymphomas and should be treated with skin therapies. Within each category, lymphomas exist that will progress and compromise internal organs.