Caracterización histológica del melanoma cutáneo en reportes de patología en la ciudad de Cali, 2016-2021 / Histological characterization of cutaneous melanoma in pathology reports in the city of Cali, 2016-2021

Introducción. El melanoma es la proliferación maligna de melanocitos asociado a un comportamiento agresivo. El objetivo de este estudio fue determinar las variables histológicas del melanoma cutáneo. Métodos. Estudio observacional retrospectivo, transversal descriptivo, realizado con reportes de patologías de pacientes con diagnóstico de melanoma cutáneo en un laboratorio de patología en Cali, Colombia, entre 2016-2021. Se incluyeron las variables edad, sexo, localización, subtipo, espesor de Breslow, ulceración, márgenes, mitosis, invasión linfovascular, neurotrofismo, regresión tumoral, nivel de Clark e infiltración tumoral por linfocitos. Resultados. Se obtuvieron 106 reportes y fueron excluidos 54 por duplicación. Se incluyeron 52 registros, la media de edad fue de 61 años, con una mayor frecuencia de mujeres (55,8 %). De los 33 casos donde se especificó el subtipo histológico, el más frecuente fue el de extensión superficial (66,6 %), seguido del acral lentiginoso (18,1 %) y nodular con (15,2 %). La localización más frecuente fue en extremidades (61,5 %). El espesor de Breslow más común fue IV (34,6 %) y el nivel de Clark más frecuente fue IV (34,6 %). La ulceración estuvo en el 40,4 %. El subtipo nodular fue el de presentación más agresiva, donde el 100 % presentaron espesor de Breslow IV. Conclusiones. El subtipo de melanoma más común en nuestra población fue el de extensión superficial; el segundo en frecuencia fue el subtipo acral lentiginoso, que se localizó siempre en extremidades. Más del 50 % de los melanomas tenían espesor de Breslow mayor o igual a III, lo que impacta en el pronóstico.

Background. Melanoma is the malignant proliferation of melanocytes associated with aggressive behavior. The objective of this study was to determine the histological variables of cutaneous melanoma. Methods. Observational, cross-sectional, descriptive, retrospective study carried out with reports of pathologies with a diagnosis of cutaneous melanoma in a pathology laboratory in Cali between 2016-2021. The variables were age, sex, location, subtype, Breslow thickness, ulceration, margins, mitosis, lymphovascular invasion, neurotropism, tumoral regression, Clark level and tumor infiltration by lymphocytes. Results. One hundred and six reports were obtained and 54 were excluded due to duplication. A descriptive analysis was made on the 52 records that were included, the mean age was 61 years, with a higher frequency in women with 55.8%. Of the 33 cases where the histological subtype was specified, the most frequent was superficial extension with 66.6%, followed by acral lentiginous with 18.1% and nodular with 15.2%. The most frequent location was in the extremities (61.5%); the most common Breslow was IV (34.6%), and the most frequent Clark was IV (34.6%). Ulceration was in 40.4%. The nodular subtype was the most aggressive presentation where 100% presented Breslow IV. Conclusions. The most common subtype of melanoma was that of superficial extension. In our population, the second most frequent was the acral lentiginous subtype, which was always located on the extremities. More than 50% of the melanomas had Breslow greater than or equal to III, which affects the prognosis.

C/EBPb converts bovine fibroblasts to adipocytes without hormone cocktail induction

BACKGROUND: Adipogenesis and fibrogenesis can be considered as a competitive process in muscle, which may affect the intramuscular fat deposition. The CCAAT/enhancer-binding protein beta (C/EBPb) plays an important role in adipogenesis, which is well-characterized in mice, but little known in bovine so far. RESULTS: In this study, real-time qPCR revealed that the level of C/EBPb was increased during the developmental stages of bovine and adipogenesis process of preadipocytes. Overexpression of C/EBPb promoted bovine fibroblast proliferation through mitotic clonal expansion (MCE), a necessary process for initiating adipogenesis, by significantly downregulating levels of p21 and p27 (p < 0.01). Also, the PPARc expression was inhibited during the MCE stage (p < 0.01). 31.28% of transfected fibroblasts adopted lipid-laden adipocyte morphology after 8 d. Real-time qPCR showed that C/EBPb activated the transcription of early stage adipogenesis markers C/EBPa and PPARc. Expression of ACCa, FASN, FABP4 and LPL was also significantly upregulated, while the expression of LEPR was weakened. CONCLUSIONS: It was concluded C/EBPb can convert bovine fibroblasts into adipocytes without hormone induction by initiating the MCE process and promoting adipogenic genes expression, which may provide new insights into the potential functions of C/EBPb in regulating intramuscular fat deposition in beef cattle.

Variables pronósticas de pacientes con melanomas gruesos. Análisis de 362 casos / Prognostic variables in patients with thick melanomas. Analysis of 362 cases

Resumen Antecedentes: Los estudios sobre factores pronóstico de melanoma están basados en poblaciones caucásicas, con predominio de melanomas delgados (Breslow < 3 mm). Los pacientes mexicanos muestran predominio de melanomas gruesos (Breslow ≥ 3 mm). Objetivo: Identificar factores asociados al pronóstico de pacientes con melanomas gruesos. Material y métodos: Se analizó la influencia pronóstica de factores clinicopatológicos en 362 melanomas gruesos. Resultados: La mediana de Breslow fue de 7 mm, 271 (74.9 %) pacientes tuvieron melanoma acral y 49 (13.5 %) melanoma nodular. El 56.6 % de los pacientes se encontró en etapa clínica [EC] III), 269 (74.3 %) tenía ulceración y 15 (4.1 %) márgenes positivos. Las variables asociadas con menor supervivencia global [SG] fueron la EC (p < 0.001), Breslow (p = 0.044), ulceración (p = 0.004), mitosis (p < 0.001) y margen < 2 cm (p < 0.001) . En el análisis multivariante los factores que influyen en SG fueron la EC, mitosis y el margen quirúrgico. Conclusiones: En pacientes con melanomas gruesos la SG es influida por un margen positive, mitosis y EC.

Abstract Background: Studies on prognostic factors in melanoma are based on Caucasian populations, with a predominance of thin melanomas (Breslow <3 mm). Mexican patients show a predominance of thick melanomas (Breslow ≥ 3 mm). Objective: To identify factors associated with the prognosis of patients with thick melanomas. Material and methods: The prognostic influence of clinicopathological factors was analyzed in 362 thick melanomas. Results: The Breslow median was 7 mm, 271 (74.9 %) patients had acral melanoma and 49 (13.5 %) nodular melanoma. The 56.6 % of patients were found in clinical stage [CS] III), 269 (74.3 %) had ulceration, and 15 (4.1 %) had positive margins. The variables associated with lower overall survival [OS] were CS (p < 0.001), Breslow (p = 0.044), ulceration (p = 0.004), mitosis (p < 0.001) and margin < 2 cm (p < 0.001). In the multivariate analysis, the factors influencing OS were CD, mitosis, and the surgical margin. Conclusions: In patients with thick melanomas, OS is influenced by a positive margin, mitosis and CS.

Neurothekeoma in the Axilla Causing Persistent Shoulder Pain: Case Report / Neurotecoma na axila causando dor persistente no ombro: Relato de caso

Abstract Neurothekeomas, also known as neural sheath myxomas, are rare benign tumors of the neural sheath affecting most commonly the head, arms and shoulder of women in their 2nd and 3rd decades of life. Due to the low prevalence and undefined clinical picture, they are hardly considered in the initial differential diagnosis of skin tumors. We report the case of a 24 year-old woman who was seen in 2016 reporting > 1 year of moderate pain and limited mobility of her left shoulder. Clinical evaluation revealed restricted mobility of the affected shoulder and nuclear magnetic resonance imaging showed a T2-weighted contrast-enhanced multilobular mass in the quadrilateral area apparently invading the adjacent humeral cortical region. Histopathology of a needle sample material revealed loose fibroconnective tissue with no signs of invasion, mitosis or atypical figures. Successful surgical excision was performed and the diagnosis of neurothekeoma was confirmed after detailed histopathology, including immunohistochemistry. The patient was asymptomatic at 18 months of follow-up, with full recovery of shoulder movement and no signs of relapse.

Resumo Neurotecomas, também conhecidos como mixomas da bainha neural, são tumores benignos raros da bainha neural afetando mais comumente a cabeça, braços e ombros de mulheres entre 20 e 40 anos de idade. Devido à baixa prevalência e quadro clínico mal definido, essas lesões são raramente consideradas no diagnóstico diferencial de tumores cutâneos. Relatamos o caso de uma mulher de 24 anos de idade que procurou atendimento em 2016 relatando dor moderada por mais de um ano e limitação dos movimentos do ombro esquerdo. Ao exame, foi constatada restrição da mobilidade dessa articulação e uma ressonância magnética revelou imagem multilobular com aumento de sinal em T2 na região quadrilateral, aparentando invasão da região cortical do úmero subjacente. A histopatologia de uma biópsia incisional mostrou lesão composta por tecido conjuntivo frouxo, sem sinais de invasão, figuras de mitose ou atipias. Foi realizada excisão completa da lesão e o diagnóstico de neurotecoma foi confirmado após análise histopatológica que incluiu painel imunohistoquímico. À revisão de 18 meses, a paciente estava assintomática com recuperação completa do movimento e sem evidência de recidiva da lesão.

Capsiate treatment in liver surgeries may compromise its recovery

Abstract Purpose: To investigate the effects of capsiate treatment on hepatic hyperplasia in partially hepatectomized rats. Methods: The animals were divided into a Capsiate group (CPH), a Capsiate Post-Partial Hepatectomy group (CPPH) and a Partial Hepatectomy Control group (PH). CPH and CPPH animals received 60 mg/kg/day Capsiate for 30 days. Next, the rats underwent partial hepatectomy. CPPH animals continued to receive treatment for 48 h after partial hepatectomy. Liver tissue and intracardiac blood samples were obtained 24 or 48 h after PH. Results: Capsiate treatment interfered with hepatic parameters, reducing the number of mitoses and apoptosis and increasing blood ALT and alkaline phosphatase concentrations. Conclusion: Capsiate treatment preceding hepatic surgery may compromise the initial period of postoperative recovery.

Natural products as new antimitotic compounds for anticancer drug development

Cell cycle control genes are frequently mutated in cancer cells, which usually display higher rates of proliferation than normal cells. Dysregulated mitosis leads to genomic instability, which contributes to tumor progression and aggressiveness. Many drugs that disrupt mitosis have been studied because they induce cell cycle arrest and tumor cell death. These antitumor compounds are referred to as antimitotics. Vinca alkaloids and taxanes are natural products that target microtubules and inhibit mitosis, and their derivatives are among the most commonly used drugs in cancer therapy worldwide. However, severe adverse effects such as neuropathies are frequently observed during treatment with microtubule-targeting agents. Many efforts have been directed at developing improved antimitotics with increased specificity and decreased likelihood of inducing side effects. These new drugs generally target specific components of mitotic regulation that are mainly or exclusively expressed during cell division, such as kinases, motor proteins and multiprotein complexes. Such small molecules are now in preclinical studies and clinical trials, and many are products or derivatives from natural sources. In this review, we focused on the most promising targets for the development of antimitotics and discussed the advantages and disadvantages of these targets. We also highlighted the novel natural antimitotic agents under investigation by our research group, including combretastatins, withanolides and pterocarpans, which show the potential to circumvent the main issues in antimitotic therapy.

Estudo retrospectivo dos pacientes portadores de melanoma cutâneo atendidos na Universidade Federal de São Paulo / Retrospective study of patients with cutaneous melanoma treated at the Federal University of São Paulo

RESUMO Objetivo: avaliar as características dos pacientes portadores de melanoma cutâneo atendidos no Hospital São Paulo - UNIFESP. Métodos: estudo retrospectivo de 184 casos de melanoma cutâneo. Foram analisadas as informações sobre sexo, idade, características do tumor, características histológicas e estadiamento. Resultados: a média de idade ao diagnóstico foi de 58,7 anos, com distribuição etária homogênea entre os sexos e predominância em indivíduos brancos (70,6%). Observou-se acometimento predominante de tronco, em homens (36,7%), e de membros inferiores, em mulheres (42%). A exposição solar, com queimaduras, foi mais comum entre homens (31,2%) do que entre mulheres (23,5%). Houve aumento de aproximadamente três vezes no acometimento linfonodal quando o índice mitótico subia de zero (11,9%) para uma ou mais mitoses por campo (36,2%), e aumento progressivo do acometimento linfonodal e de desfechos ruins quanto maior a espessura de Breslow: 10,2% quando menor do que 1mm e 59,2% quando maior do que 4mm. Conclusão: as características dos pacientes portadores de melanoma cutâneo atendidos no Hospital São Paulo são semelhantes às encontradas na literatura.

ABSTRACT Objective: to evaluate the characteristics of the patients with cutaneous melanoma treated at the São Paulo Hospital - UNIFESP. Methods: we conducted a retrospective study of 184 cases of cutaneous melanoma. We analyzed information on gender, age, tumor characteristics, histological characteristics and staging. Results: mean age at diagnosis was 58.7 years, with homogeneous age distribution between genders and predominance in white individuals (70.6%). There was a predominance of trunk involvement in men (36.7%) and lower limbs in women (42%). Sun exposure, with sunburns, was more common among males (31.2%) than among females (23.5%). There was an approximately three-fold increase in lymph node involvement when the mitotic index rose from zero (11.9%) to one or more mitosis per field (36.2%). In addition, the greater the Breslow thickness, the greater the lymph node involvement and poor the outcomes: 10.2% when less than 1mm and 59.2% when greater than 4mm. Conclusion: the characteristics of patients with cutaneous melanoma treated at Hospital São Paulo are similar to those found in the literature.

Cytogenotoxicity of rice crop water after application of the tricyclazole fungicide

ABSTRACT Tricyclazole is currently one of the fungicides recommended for the treatment of diseases in irrigated rice. However, there is relatively little information on its cytotoxic and genotoxic potential. The objective of this study was to evaluate the cytotoxicity and genotoxicity of rice crop water after apllication of the tricyclazole fungicide through the Allium cepa L. test. The rice crop water samplings were collected before and 1, 15 and 30 days after application of the fungicide in rice plant shoots. The Allium cepa roots were placed in contact with the rice crop water to check for possible chromosomal abnormalities and mitotic index of the bioindicators meristematic cells. The data obtained by the Allium cepa test indicates that the application of the tricyclazole fungicide leads to an increase in the genotoxic activity in the rice crop water, through the appearance of chromosomal abnormalities, without, however, causing significant effects on the mitotic index. The major chromosomal alterations observed were anaphasic and telophasic bridges and laggard chromosomes.

Antiproliferative and genotoxic effects of nature identical and artificial synthetic food additives of aroma and flavor / Efeito antiproliferativo e genotóxico de aditivos alimentares de aroma e sabor sintéticos, dos tipos idêntico ao natural e artificial

Abstract This study aimed to analyze the antiproliferative and genotoxic potential of synthetic food flavorings, nature identical passion fruit and artificial vanilla. This assessment used root meristem cells of Allium cepa L., in exposure times of 24 and 48 hours and using doses of 0.2; 0.4 and 0.6 mL. Roots were fixed in Carnoy’s solution, hydrolyzed in hydrochloric acid, stained with acetic orcein and analyzed with optical microscope at 400× magnification, 5,000 cells for each treatment. For data analysis, it was used Chi-square test at 5%. Doses of 0.2 mL at ET 48 h; 0.4 and 0.6 mL at ET 24 and 48 h of passion fruit flavor, and the three doses of the vanilla flavor at ET 24 and 48 h significantly reduced the cell division rate in the meristems of roots, proving to be cytotoxic. Doses of 0.2; 0.4 and 0.6 mL of the passion fruit additive, and the three doses of vanilla tested, in the two exposure times, induced mitotic spindle changes and micronuclei formation in the cells of the test organism used, proving to be genotoxic. Therefore, under the studied conditions, flavoring solutions of vanilla and passion fruit, marketed nationally and internationally, significantly altered the functioning of the cell cycle in root meristem cells of A. cepa.

Resumo Neste trabalho teve-se por objetivo analisar o potencial antiproliferativo e genotóxico de aromatizantes alimentares sintéticos, idêntico ao natural de Maracujá, e artificial de Baunilha. Esta avaliação foi realizada por meio das células meristemáticas de raízes de Allium cepa L., nos tempos de exposição de 24 e 48 horas e nas doses de 0,2; 0,4 e 0,6 ml. As raízes foram fixadas em solução de Carnoy, hidrolisadas em ácido clorídrico e coradas com orceína acética. Analisou-se, em microscópio óptico em aumento de 400×, 5.000 células por grupo tratamento, e utilizou-se o teste estatístico Qui-quadrado a 5% para análise dos dados. Verificou-se que as doses de 0,2 ml, no TE 48 h; 0,4 e 0,6 ml, nos TE 24 e 48 h, do aromatizante de Maracujá, e as três doses analisadas, nos TE 24 e 48 h, do aditivo de Baunilha reduziram significativamente o índice de divisão celular dos meristemas de raízes, mostrando-se citotóxicas. As doses 0,2; 0,4 e 0,6 ml do aditivo de Maracujá, e a de 0,6 ml do aromatizante de Baunilha, nos dois tempos de exposição considerados, induziram alterações de fuso mitótico e micronúcleos as células do organismo de prova utilizado, mostrando-se genotóxicas. Portanto, nas condições analisadas, as soluções aromatizantes de Baunilha e Maracujá, comercializadas nacional e internacionalmente, alteraram significativamente o funcionamento do ciclo celular das células meristemáticas de raízes de A. cepa.

Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

Apolipoprotein E (APOE=gene, apoE=protein) is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln) treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE-/-) and wild-type (APOE+/+) C57BL6J male and female mice (N=86) were given either Ala-Gln (100 mM) or phosphate buffered saline (PBS) by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU) challenge (450 mg/kg, via intraperitoneal injection). Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1) and B-cell lymphoma 2 (Bcl-2) intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001) in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05) were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE-/- mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE+/+ mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE-/--challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU challenge.

A possible role of Drosophila CTCF in mitotic bookmarking and maintaining chromatin domains during the cell cycle

BACKGROUND: The CCCTC-binding factor (CTCF) is a highly conserved insulator protein that plays various roles in many cellular processes. CTCF is one of the main architecture proteins in higher eukaryotes, and in combination with other architecture proteins and regulators, also shapes the three-dimensional organization of a genome. Experiments show CTCF partially remains associated with chromatin during mitosis. However, the role of CTCF in the maintenance and propagation of genome architectures throughout the cell cycle remains elusive. RESULTS: We performed a comprehensive bioinformatics analysis on public datasets of Drosophila CTCF (dCTCF). We characterized dCTCF-binding sites according to their occupancy status during the cell cycle, and identified three classes: interphase-mitosis-common (IM), interphase-only (IO) and mitosis-only (MO) sites. Integrated function analysis showed dCTCF-binding sites of different classes might be involved in different biological processes, and IM sites were more conserved and more intensely bound. dCTCF-binding sites of the same class preferentially localized closer to each other, and were highly enriched at chromatin syntenic and topologically associating domains boundaries. CONCLUSIONS: Our results revealed different functions of dCTCF during the cell cycle and suggested that dCTCF might contribute to the establishment of the three-dimensional architecture of the Drosophila genome by maintaining local chromatin compartments throughout the whole cell cycle.

Evaluation of liver regeneration with use of diet supplemented with l-arginine

PURPOSE: To compare controlled liver regeneration in rats submitted to 60% hepatic resection having L-arginine supplemented diet, based on weight changes of the regenerated liver, laboratory parameters of liver function and pathological findings. METHODS: Thirty-six rats were divided into two groups, control and L- arginine. The first received standard chow and saline solution by gavage. The second had supplementation with L- arginine. Animals were killed on postoperative period at 24h, 72h and seven days. For analysis of liver regeneration was used Kwon formula for weight, laboratory tests and mitosis. RESULTS: Weight, showed no benefit with L- arginine supplementation; however, intergroup comparison in the first 24h observed positive effect on supplementation (p=0.008). Alkaline phosphatase was increased in arginine group (p<0.04). The number of mitoses showed no difference between the two groups; however, in the first 24 hours, the supplemented group had higher number of mitoses within the groups (p=0.03). CONCLUSION: Supplementation with L-arginine did not show benefits in liver regeneration; however, supplemented group in the first 24 hours showed benefits over 72 hours and seven days of the evaluation by weight gain and number of mitosis. .

Los cromosomas de las tortugas tropicales: Kinosternon leucostomum, Trachemys scripta y Staurotypus triporcatus (Testudines: Kinosternidae/Emydidae) / Tropical turtles chromosomes: Kinosternon leucostomum, Trachemys scripta and Staurotypus triporcatus (Testudines: Kinosternidae/Emydidae)

Mexico is a biodiverse country in several taxa as reptiles, that include several species of freshwater and marine turtles. Eventhough most of this group species are under protection, Tabasco State has nine native freshwater turtles, like Kinosternon leucostomum, Trachemys scripta and Staurotypus triporcatus that are very important in traditional dishes. This has resulted in a critical level of their populations, together with little biological knowledge for their conservation. Therefore, this study was dedicated to turtle cytogenetics. The study was conducted using the conventional methods for cytogenetics. The results showed the modal diploid and haploid number for K. leucostomum of 2n=56 (2n=56+3 microchromosomes “B”) and 1n=28 chromosomes in mitosis and meiosis, respectively. In T. scripta 2n=50 chromosomes (2n=50+2 microchromosomes “B”) and 1n=25 chromosomes were also characterized. Whereas in S. triporcatus we only report the 2=54 chromosomes (2n=54+2 microchromosomes “B”). The karyological formula for K. leucostomum was integrated by 12 metacentric-submetacentric chromosomes “msm”/”A”+22 subtelocentrictelocentric chromosomes “stt”/”B”+22 telocentric chromosomes “T”/”C” with fundamental number (FN) of 90 chromosome arms. While T. scripta karyotype was integrated by 32 “msm/”A”+10 “stt”/”B”+8”T/”C” chromosomes, with FN of 92 arms. S. triporcatus karyotype formula was built up by 20 chromosomes “msm”/”A”+34 chromosomes “T”/”C” with FN of 74. The variation in chromosome classification, the fundamental number and the presence of supernumerary microchromosomes “B” in the studied species, were evidence of a particular chromosome cytotypes in Tabasco. We considered that the presence of microchromosomes “B” probably has different origins, and they may be very important as a pattern for the formation or separation of new species. This study also showed the absence of heterologous chromosomes between the females and males karyotypes from the studied species. Rev. Biol. Trop. 62 (2): 671-688. Epub 2014 June 01.

México es un país biodiverso en varios grupos taxonómicos incluyendo a los reptiles, por ello en el país existen varias especies de tortugas dulceacuícolas y marinas. Las especies que integran dicho grupo se encuentran dentro del listado de especies sujetas a protección. El estado de Tabasco cuenta con nueve especies de tortugas de agua dulce, de las cuales Kinosternon leucostomum, Trachemys scripta y Staurotypus triporcatus son de las más importantes dentro de la tradición culinaria, hecho que las ha llevado a niveles críticos en sus poblaciones; aunado al poco conocimiento biológico que sobre dichas especies existe para conservarlas. Por lo anterior, el presente estudio de citogenética es el primero en tortugas de agua dulce en la región. El estudio se realizó, empleando el método convencional de citogenética. Los resultados muestran, el número modal diploide y haploide de K. leucostomum de 2n=56 (2n=56+3 microcromosomas “B”) y 1n=28 cromosomas 686 en mitosis y meiosis, respectivamente. En T. scripta de 2n=50 cromosomas (2n=50+2 microcromosomas “B”) y 1n=25 cromosomas. Mientras que en S. triporcatus solo se reporta el 2n=54 cromosomas (2n=54+2 microcromosomas “B”). La fórmula cromosómica en K. leucostomum, fue de 12 cromosomas metacéntricos submetacéntricos “msm”/“A”+22 cromosomas subtelocéntricos-telocéntricos “stt”/“B”+22 cromosomas telocéntricos “T”/“C”, con número fundamental (NF) de 90 brazos cromosómicos. En T. scripta fue de 32 cromosomas “msm”/“A”+10 cromosomas “stt”/“B”+8 cromosomas “T”/“C”, con NF de 92 y en S. triporcatus 20 cromosomas “msm”/“A”+34 cromosomas “T”/“C” con NF de 74. La variación en la clasificación cromosómica, el número fundamental y la presencia de microcromosomas “B” supernumerarios en las tres especies, son evidencia de citotipos cromosómicos particulares de las tortugas de Tabasco. Se argumenta que la presencia de los microcromosomas “B” tiene diferentes orígenes y de su importancia como pauta para la formación o separación de nuevas especies. En el estudio se descarta la presencia de cromosomas heterólogos entre las hembras y los machos de las especies estudiadas.

La proliferación de los miocitos ventriculares del corazón de mamífero adulto: un fenómeno esporádico pero factible / Proliferation of adult mammalian ventricular cardiomyocytes: A sporadic but feasible phenomenon

La proliferación de los miocitos que forman parte de los ventrículos cardíacos del mamífero adulto ha sido descartada por algunos investigadores con el argumento de que estas células están diferenciadas en forma terminal; sin embargo, este dogma ha sido puesto en duda a partir de los hallazgos de otros investigadores quienes han observado que estos miocitos pueden presentar los procesos necesarios para la proliferación, es decir síntesis de ADN, mitosis y citocinesis, cuando el miocardio se daña en forma experimental con estrategias de tipo farmacológico o quirúrgico, o debido a condiciones patológicas relacionadas con el sistema cardiovascular. Esta revisión integra algunos de los trabajos disponibles en la literatura que han evaluado la síntesis del ADN, mitosis y citocinesis en estas células, en el miocardio dañado, para saber si su proliferación puede ser considerada como un fenómeno factible. La revisión concluye con una reflexión sobre las perspectivas del conocimiento generado en esta área de estudio.

Proliferation of adult mammalian ventricular cardiomyocytes has been ruled out by some researchers, who have argued that these cells are terminally differentiated; however, this dogma has been rejected because other researchers have reported that these cells can present the processes necessary to proliferate, that is, DNA synthesis, mitosis and cytokinesis when the heart is damaged experimentally through pharmacological and surgical strategies or due to pathological conditions concerning the cardiovascular system. This review integrates some of the available works in the literature evaluating the DNA synthesis, mitosis and cytokinesis in these myocytes, when the myocardium is damaged, with the purpose of knowing if their proliferation can be considered as a feasible phenomenon. The review is concluded with a reflection about the perspectives of the knowledge generated in this area.

Simultaneous silencing of VEGF and KSP by siRNA cocktail inhibits proliferation and induces apoptosis of hepatocellular carcinoma Hep3B cells

BACKGROUND: Vascular endothelial growth factor (VEGF) is involved in the growth of new blood vessels that feed tumors and kinesin spindle protein (KSP) plays a critical role in mitosis involving in cell proliferation. Simultaneous silencing of VEGF and KSP, an attractive and viable approach in cancer, leads on restricting cancer progression. The purpose of this study is to examine the therapeutic potential of dual gene targeted siRNA cocktail on human hepatocellular carcinoma Hep3B cells. RESULTS: The predesigned siRNAs could inhibit VEGF and KSP at mRNA level. siRNA cocktail showed a further downregulation on KSP mRNA and protein levels compared to KSP-siRNA or VEGF-siRNA, but not on VEGF expression. It also exhibited greater suppression on cell proliferation as well as cell migration or invasion capabilities and induction of apoptosis in Hep3B cells than single siRNA simultaneously. This could be explained by the significant downregulation of Cyclin D1, Bcl-2 and Survivin. However, no sigificant difference in the mRNA and protein levels of ANG2, involving inhibition of angiogenesis was found in HUVECs cultured with supernatant of Hep3B cells treated with siRNA cocktail, compared to that of VEGF-siRNA. CONCLUSION: Silencing of VEGF and KSP plays a key role in inhibiting cell proliferation, migration, invasion and inducing apoptosis of Hep3B cells. Simultaneous silencing of VEGF and KSP using siRNA cocktail yields promising results for eradicating hepatocellular carcinoma cells, a new direction for liver cancer treatment.

Cariotipo de Espeletiopsis muiska / Karyotype of Espeletiopsis muiska

Objetivo. Estudiar el ciclo celular y realizar la descripción cromosómica de Espeletiopsis muiska, utilizando células meristemáticas de ápices radicales obtenidos a través de cultivo in vitro de embriones en medio MS suplementado con AIB. Materiales y métodos. Se colectaron ápices radicales a diferentes horas del día y se contaron en ellos las células presentes en cada fase mitótica, se determinó la duración del ciclo celular y la hora de mayor actividad mitótica. La descripción de los cromosomas y la elaboración del cariotipo de la especie, se realizó utilizando un protocolo que permitió la obtención de cromosomas metafásicos. Resultados. Respecto a la duración del ciclo celular, se encontró que la interfase comprende el 94.65% y la mitosis el 5.35% del total del ciclo celular. Entre las fases mitóticas la profase tiene mayor duración, 1.92%, mientras que la anafase es la más corta, 0.96%. En cuanto a la hora mitótica, las células meristemáticas de los ápices radicales presentaron mayor actividad entre las 10:30 y las 11:15. Con el estudio citogenético se encontraron 19 pares de cromosomas con longitudes e índices centroméricos similares y cariotipo asimétrico. Conclusiones. El estudio detallado de los cromosomas, permitió determinar un complemento cromosómico 2n=38+2B, dos cromosomas con microsatélites terminales y uno con constricción secundaria.

Objective. The cell cycle and chromosomic description of Espeletiopsis muiska was studied in meristematic cells of root tips obtained from in vitro culture of embryos on MS medium supplemented with IBA. Materials and methods. Root tips at different times of day were collected and the cells in each mitotic phase were counted. With this information, the cell cycle length and mitotic activity was determined at its peak hours. Description of chromosomes and elaboration of karyotype of the specie was done with a protocol that allows obtaining metaphase chromosomes. Results. Regarding the cell cycle length, we found that the interface includes the 94.65% and mitosis the 5.35% of total cell cycle. Regarding the mitotic phases, the prophase lasts longer, 1.92%, while the anaphase is the shortest, 0.96%. As to mitotic hour, meristematic cells of root tips showed an increased activity between 10:30 and 11:15. 19 pairs of chromosomes with similar lengths, similar centromeric indices and asymmetrical karyotype were found in this cytogenetic study. Conclusions. The detailed study of the chromosomes revealed a chromosome complement 2n=38+2B, two chromosomes with microsatellite terminals and one with a secondary constriction.

The jejunoileal bypass provokes morphological changes in the large intestine? An experimental study in rats / A derivação jejuno-ileal provoca alterações morfológicas no intestino grosso? Estudo experimental em ratos

PURPOSE: To analyse histopathological alterations characterized by the mitotic index in the mucosa of the large intestine in Wistar rats submitted to jejunoileal bypass operation after continued administration of sodium nitrite and vitamin C to different groups. METHODS: Eighty male Wistar rats were employed and separated into 12 groups. In the control group (20 rats): five animals ingested only water; five animals received vitamin C; five animals received sodium nitrite and five received sodium nitrite + vitamin C. In the sham group (20 rats), the animals were anesthetized and underwent midline laparotomy and only intestinal manipulation was performed: five animals ingested only water; five animals received vitamin C; five animals received sodium nitrite and five received sodium nitrite + vitamin C. In the operated group 40 rats underwent a jejunoileal bypass surgery: ten animals ingested only water; ten animals received vitamin C; ten animals received sodium nitrite and ten received sodium nitrite + vitamin C. The mean weight of the animals was measured weekly. The large intestine was subdivided into cecum (S1), ascending colon (S2), transverse colon (S3), descending colon (S4) and rectum (S5) for histopathological analysis and mitotic counts. The statistical analysis was used to compare the mitotic indices. The level of significance was 5%. RESULTS: The mean of all the segments indicates that the sodium nitrite+vitamin C group obtained the lowest mitotic index compared to the other treatments in the control group. The segments S1 and S2 showed a statistical difference with the vitamin C treatment: a higher mitotic index and better preservation of the mucosa in the operated group. In the sham group the main statistical difference occurred only in the sodium nitrite+vitamin C group between the means of the segments. CONCLUSIONS: The comparison of all the colonic segments of the various groups revealed a lower mitotic index in the animals treated with sodium nitrite+vitamin C. In addition, it was found that vitamin C did not present a statistically significant inhibiting effect on the preservation of the mucosa and the mitotic index.

OBJETIVO: Analisar as alterações histopatológicas caracterizada pelo índice mitótico na mucosa do intestino grosso em ratos Wistar submetidos a operação de bypass jejunoileal após a administração continuada de nitrito de sódio e vitamina C para diferentes grupos. MÉTODOS: Oitenta ratos Wistar foram utilizados e separados em 12 grupos. No grupo controle (20 ratos): cinco animais ingeriram apenas água; cinco animais receberam vitamina C, cinco animais receberam nitrito de sódio e cinco receberam nitrito de sódio + vitamina C. No grupo sham (20 ratos), os animais foram anestesiados e submetidos a laparotomia mediana e só a manipulação intestinal foi realizada: cinco animais ingeriram apenas água; cinco animais receberam vitamina C, cinco animais receberam nitrito de sódio e cinco receberam nitrito de sódio + vitamina C. No grupo operado 40 ratos foram submetidos a uma cirurgia de bypass jejunoileal: dez animais ingeridos apenas água; dez animais receberam vitamina C, dez animais receberam nitrito de sódio e dez nitrito de sódio + vitamina C. O peso médio dos animais foi medido semanalmente. O intestino grosso foi subdividido em ceco (S1), cólon ascendente (S2), cólon transverso (S3), cólon descendente (S4) e reto (S5) para análise histopatológica e contagem das mitoses. A análise estatística foi utilizado para comparar os índices mitóticos. O nível de significância foi de 5%. RESULTADOS: A média de todos os segmentos indica que o grupo que ingeriu nitrito de sódio + vitamina C obteve o menor índice mitótico em relação aos demais tratamentos no grupo controle. Os segmentos S1 e S2 mostraram uma diferença estatística com a vitamina C de tratamento: um maior índice mitótico e melhor preservação da mucosa no grupo operado. No grupo sham a principal diferença estatística ocorreu apenas no grupo que ingeriu nitrito de sódio + vitamina C entre as médias dos segmentos. CONCLUSÕES: A comparação de todos os segmentos do colon dos vários grupos revelaram um menor índice de mitose nos animais tratados com nitrito de sódio + vitamina C. Além disso, a vitamina C não apresentou efeito inibidor, estatísticamente significativo, na preservação da mucosa e do índice de mitoses.

Mitose como fator prognóstico para biópsia de linfonodo sentinela em melanoma fino / The importance of mitosis as a factor for predicting sentinel lymph node biopsy for thin melanoma

Paciente, sexo feminino, 23 anos, com melanoma extensivo superficial em dorso, Breslow 0,35 mm, Clark II, sem ulcerações e com 2 mitoses / mm². Foi submetida à ampliação de margem e biópsia de dois linfonodos sentinela (axila esquerda). O exame anatomopatológico mostrou micrometástases, no seio subcapsular de ambos. Seguindo a recomendação do "American Joint Commitee on Cancer" 2009, a paciente foi submetida à linfadenectomia axilar total, sem outros linfonodos metastáticos. A aplicação da dermatoscopia vem permitindo maior precisão diagnóstica de melanoma cutâneo, contribuindo para maior proporção de melanoma fino ao diagnóstico. A taxa mitótica foi incluída como um importante fator prognóstico para melanomas finos pelo "American Joint Commitee on Cancer" 2009, sugerindo biópsia para esses pacientes.

23-year-old female patient, with superficial spreading melanoma (SSM) on the back, Breslow 0.35 mm, Clark II, without ulceration and with 2 mitosis/mm². Patient was submitted to margin enlargement and sentinel biopsy of 2 lymph nodes (left armpit). Histopathology revealed micrometastasis in the subcapsular sinus of both. Following the recommendation of the 2009 American Joint Committee on Cancer Melanoma Staging (AJCC), the patient underwent complete axillary lymphadenectomy. No other lymph nodes were metastatic. The clinical application of dermoscopy has enabled more accurate diagnosis of cutaneous melanoma, probably contributing to a greater proportion of thin melanomas at diagnosis. The mitotic rate was included as an important prognostic factor for thin melanomas by the AJCC, suggesting biopsy for these patients.

Schistosoma mansoni polo-like kinases and their function in control of mitosis and parasite reproduction

Polo-like kinases are important regulators of cell cycle progression and mitosis. They constitute a family of conserved serine/threonine kinases which are highly related in their catalytic domains and contain polo boxes involved in protein-protein interactions and subcellular localization. In mammals, five Plks (Plk 1-5) encompass diverse roles in centrosome dynamics, spindle formation, intra S-phase and G2/M checkpoints and DNA damage response. Plk1 is a key positive regulator of mitosis and is overexpressed in various types of cancers. Plk4 is a divergent member of the Plk family, with essential functions in centriole duplication. Homozygous disruption of Plk1 or Plk4 in mice is lethal in embryos. Two Plk members SmPlk1 and SmSak, homologous to Plk1 and Plk4 respectively, are present in the parasitic platyhelminth Schistosoma mansoni. Structural and functional analyses of SmPlk1 have demonstrated its conserved function in the regulation of cell cycle G2/M transition in Xenopus oocytes. The anti-cancer drug BI 2536 (the most potent and selective Plk1 inhibitor) inhibits specifically the catalytic activity of SmPlk1 and induced profound alterations in schistosome gonads, indicating a role of SmPlk1 in parasite gametogenesis and its potential as a novel chemotherapeutic target against schistosomiasis. Functions of SmSak in cell cycle regulation and schistosome gonad development are currently investigated.

Quinases do tipo Polo ("polo-like") são importantes reguladores da progressão do ciclo celular e da mitose. Elas constituem uma família de serina/treonina quinases que são altamente relacionadas entre si no seu domínio catalítico e contêm blocos "polo" envolvidos com interações proteína-proteína e com localização subcelular. Em mamíferos, cinco Plks (Plk 1-5) englobam diversos papéis na dinâmica do centrossomo, formação do fuso, "checkpoints" dentro da fase S e da transição G2/M, e na resposta aos danos do DNA. Plk1 é um regulador positivo chave da mitose, e é superexpresso em vários tipos de câncer. Plk4 é um membro divergente da família Plk, com funções essenciais na duplicação do centríolo. Deleção homozigótica de Plk1 ou Plk4 em camundongos é letal em embriões. Dois membros da família Plk, SmPlk1 e SmSak, homólogos a Plk1 e Plk4, respectivamente, estão presentes no parasita platelmíntico Schistosoma mansoni. Análises estruturais e funcionais de SmPlk1 demonstraram uma função conservada na regulação da transição G2/M do ciclo celular em ovócitos de Xenopus. A droga anticâncer BI2536 (o inibidor mais potente e seletivo de Plk1) inibe específicamente a atividade catalítica de SmPlk1 e induz alterações profundas nas gonadas de esquistossomos, indicando um papel de SmPlk1 na gametogênese do parasita e seu potencial como um alvo terapêutico novo contra a esquistossomose. As funções de SmSak na regulação do ciclo celular e no desenvolvimento das gônadas de esquistossomos estão sendo investigadas no momento.

Caracterización cariotípica en mitosis y meiosis del robalo blanco Centropomus undecimalis (Pisces: Centropomidae)

Karyotypic characterization in mitosis and meiosis of the common snook Centropomus undecimalis (Pisces: Centropomidae). The common snook Centropomus undecimalis inhabits marine, brackish and freshwater habitats in the Western Central Atlantic Ocean, including the Gulf of Mexico. Common snook is an economically important fish in many localities, nevertheless the number of studies on its biology and genetics are still few. The present study attempts to establish the cytogenetic profiles of the specimens collected in Paraiso Municipality Tabasco, Mexico. Tissue of five females and eight male organisms were processed by conventional cytological techniques to obtain chromosome slides of high quality in order to assemble the karyotype. The results from the kidney tissue analysis showed that 85.1% of 288 mitosis had a 2n=48 chromosomes, and 52.8% of 104 meiosis exhibited the haploid number 1n=24. The diploid karyotype showed 48 monoarmed chromosomes of the telocentric (T) type. There was no chromosome heteromorphism between females and males. The diploid karyotype was very similar to that observed in the majority of marine fishes. Rev. Biol. Trop. 59 (2): 683-692. Epub 2011 June 01.

El robalo blanco Centropomus undecimalis, vive en hábitats marinos, salobres y dulceacuícolas en el océano Atlántico occidental, incluyendo el golfo de México. La especie, es económicamente importante en varias localidades, no obstante los estudios sobre su biología y genética son hasta el momento pocos. El presente estudio tiene como propósito, la caracterización citogenética de especímenes recolectados en el municipio de Paraíso, Tabasco, México. Cinco hembras y ocho machos fueron procesados por técnicas citológicas convencionales para la obtención de preparaciones cromosómicas de buena calidad para elaborar el cariotipo. Los resultados del análisis del tejido del riñón, mostraron que 85.1% de 288 mitosis tienen 2n=48 cromosomas y 52.8% de 104 meiosis exhiben el número haploide de 1n=24. El cariotipo diploide mostro 48 cromosomas monorrámeos de tipo telocéntrico (T). No se observó heteromorfismo cromosómico entre hembras y machos. El cariotipo diploide fue similar a los observados en la mayoría de peces marinos.