5α-Reductase type 2 deficiency in families from an isolated Andean population in Venezuela.

5α-Reductase type 2 deficiency causes a 46,XY disorder of sex development (DSD) characterized by ambiguous external genitalia, rudimentary prostate, and normal internal genitalia. The disease prevalence worldwide is low, but in a small and isolated village of the Venezuelan Andes, a higher incidence has been found. DNA analysis of the SRD5A2 gene was performed in three inbred affected individuals clinically diagnosed with DSD. The entire coding regions, the p.L89V polymorphism (rs523349) and five intragenic SNPs (rs2300702, rs2268797, rs2268796, rs4952220, rs12470196) used to construct haplotypes were analyzed by Sanger sequencing. To assess the probable ethnic origin of the mutation in this geographic isolate, a population structure analysis was performed. Homozygosis for the p.N193S mutation was found in all patients, with a mutation carrier frequency of 1:80 chromosomes (0.0125) in the geographic focus, suggesting a founder phenomenon. The results of the population structure analysis suggested a mutation origin closer to the Spanish populations, according to the clusters grouping. The genotype-phenotype correlation in the patients was not absolute, being hypospadias and cryptorchidism the main traits that differentiate affected individuals.

Synthesis of three triterpene series and their activity against respiratory syncytial virus.

The human respiratory syncytial virus (hRSV) is a leading cause of hospitalization due to acute lower respiratory infection especially in infants and young children, sometimes causing fatal cases. The monoclonal antibody palivizumab is one of the available options for preventing this virus, and at the moment there are several hRSV vaccine trials underway. Unfortunately, the only drug option to treat hRSV infection is ribavirin, which can be used in severe high-risk cases. For this reason, new medicines are needed and, in this context, the triterpenes and their derivatives are promising alternatives, since many of them have shown important antiviral activity, such as bevirimat. Therefore, we report three series of triterpene (betulin (BE), betulinic acid (BA), and ursolic acid (UA)) derivatives tested against hRSV. The derivatives were synthesized by using commercial anhydrides in an easy and inexpensive step reaction. For the antiviral assay, A549 cells were infected by hRSV and after 96 h of compound or ribavirin (positive control) treatment, the cell viability was tested by MTT assay. DMSO, non-infected cells and infected cells without treatment were used as negative control. The triterpene esterification at the hydroxyl group resulted in 17 derivatives. The 3,28-di-O-acetylbetulin derivative (1a) showed the best results for cell viability, and real-time PCR amplification was performed for 1a treatment. Remarkably, one new anti-hRSV prototype was obtained through an easy synthesis of BE, which shall represent an alternative for a new lead compound for anti-hRSV therapy.

Caatinga plants: Natural and semi-synthetic compounds potentially active against Trichomonas vaginalis.

Trichomonas vaginalis causes trichomoniasis; the most common but overlooked non-viral sexually transmitted disease worldwide. The treatment is based at 5'-nitroimidazoles, however, failure are related to resistance of T. vaginalis to chemotherapy. Caatinga is a uniquely Brazilian region representing a biome with type desert vegetation and plants present diverse biological activity, however, with few studies. The aim of this study was to investigate the activity against T. vaginalis of different plants from Caatinga and identify the compounds responsible by the activity. A bioguided fractionation of Manilkara rufula was performed and four major compounds were identified: caproate of α-amyrin (1b), acetate of ß-amyrin (2a), caproate of ß-amyrin (2b), and acetate of lupeol (3a). In addition, six derivatives of α-amyrin (1), ß-amyrin (2) and lupeol (3) were synthesized and tested against the parasite. Ursolic acid (5) reduced about 98% of parasite viability after 2h of incubation and drastic ultrastructural alterations were observed by scanning electron microscopy. Moreover, 5 presented high cytotoxicity to HMVII and HeLa cell line and low cytotoxicity against Vero line at 50 µM (MIC against the parasite). Metronidazole effect against T. vaginalis resistant isolate was improved when in association with 5.

Two series of new semisynthetic triterpene derivatives: differences in anti-malarial activity, cytotoxicity and mechanism of action.

BACKGROUND: The discovery and development of anti-malarial compounds of plant origin and semisynthetic derivatives thereof, such as quinine (QN) and chloroquine (CQ), has highlighted the importance of these compounds in the treatment of malaria. Ursolic acid analogues bearing an acetyl group at C-3 have demonstrated significant anti-malarial activity. With this in mind, two new series of betulinic acid (BA) and ursolic acid (UA) derivatives with ester groups at C-3 were synthesized in an attempt to improve anti-malarial activity, reduce cytotoxicity, and search for new targets. In vitro activity against CQ-sensitive Plasmodium falciparum 3D7 and an evaluation of cytotoxicity in a mammalian cell line (HEK293T) are reported. Furthermore, two possible mechanisms of action of anti-malarial compounds have been evaluated: effects on mitochondrial membrane potential (ΔΨm) and inhibition of ß-haematin formation. RESULTS: Among the 18 derivatives synthesized, those having shorter side chains were most effective against CQ-sensitive P. falciparum 3D7, and were non-cytotoxic. These derivatives were three to five times more active than BA and UA. A DiOC(6)(3) ΔΨm assay showed that mitochondria are not involved in their mechanism of action. Inhibition of ß-haematin formation by the active derivatives was weaker than with CQ. Compounds of the BA series were generally more active against P. falciparum 3D7 than those of the UA series. CONCLUSIONS: Three new anti-malarial prototypes were obtained from natural sources through an easy and relatively inexpensive synthesis. They represent an alternative for new lead compounds for anti-malarial chemotherapy.

[Clinical and molecular study of the Noonan syndrome]. / Estudio clínico y molecular del síndrome de Noonan.

Noonan syndrome is a relatively common autosomal dominant entity, clinically variable and genetically heterogeneous; characterized by postnatally reduced growth, distinctive facial dysmorphism, cardiac defects and variable cognitive deficits. The PTPN11 gene is located on the long arm of chromosome 12 and is primarily responsible for the clinically diagnosed cases of this entity. We report the case of a 18 month-old boy, evaluated in a multidisciplinary way, with clinic and molecular diagnosis of Noonan syndrome, with the missense mutation in PTPN11 gene, G503R (c.1507 G>A). Several clinical features and the genetic alterations associated with this mutation are discussed.

The Relationship Between Different Bench Test Methodologies and Accuracy of Insulin Infusion Pumps: A Systematic Literature Review.

Diabetes technology has rapidly evolved, and insulin infusion pumps (IIPs) have gained worldwide acceptance in diabetes care. The safety of medical equipment is highly discussed, imposing complex challenges in its use. The accuracy of IIPs can be determined through laboratory tests, generally following the IEC 60601-2-24 protocol. Studies have evaluated the accuracy and precision of IIPs, and there are discrepant results. So, we conducted a Systematic Literature Review to assess the methodologies used to evaluate the accuracy of IIPs, organizing the findings in a compiled perspective. The methodology was based on Kitchenham and Biolchini guidelines, and when possible it was carried out the Bayesian meta-analyses to compare the accuracy of IIPs. Most studies used the microgravimetric technique to evaluate the device accuracy, and some proposed adaptations for the standard protocol. The variation of results was recurrent, and the establishment of a protocol, especially to evaluate patch pumps, is necessary. The present study gives enough data to understand the scenario of the IIPs evaluation, as well as the different protocols that can be explored for its evaluation. This highlights the need for a reliable, practical, and low-cost methodology to assist the evaluation of IIPs.

[Pearson syndrome. Case report]. / Síndrome de Pearson. Reporte de un caso.

Among the etiologies of anemia in the infancy, the mitochondrial cytopathies are infrequent. Pearson syndrome is diagnosed principally during the initial stages of life and it is characterized by refractory sideroblastic anemia with vacuolization of marrow progenitor cells, exocrine pancreatic dysfunction and variable neurologic, hepatic, renal and endocrine failures. We report the case of a 14 month-old girl evaluated by a multicentric study, with clinic and molecular diagnosis of Pearson syndrome, with the 4,977-base pair common deletion of mitochondrial DNA. This entity has been associated to diverse phenotypes within the broad clinical spectrum of mitochondrial disease.

Design, synthesis, and evaluation of Bothrops venom serine protease peptidic inhibitors.

BACKGROUND: In Central and South America, snakebite envenomation is mainly caused by Bothrops spp. snakes, whose venoms feature significant biochemical richness, including serine proteases. The available bothropic antivenoms are efficient in avoiding fatalities, but do not completely neutralize venom serine proteases, which are co-responsible for some disorders observed during envenomation. METHODS: In order to search for tools to improve the antivenom's, 6-mer peptides were designed based on a specific substrate for Bothrops jararaca venom serine proteases, and then synthesized, with the intention to selectively inhibit these enzymes. RESULTS: Using batroxobin as a snake venom serine protease model, two structurally similar inhibitor peptides were identified. When tested on B. jararaca venom, one of the new inhibitors displayed a good potential to inhibit the activity of the venom serine proteases. These inhibitors do not affect human serine proteases as human factor Xa and thrombin, due to their selectivity. CONCLUSION: Our study identified two small peptides able to inhibit bothropic serine proteases, but not human ones, can be used as tools to enhance knowledge of the venom composition and function. Moreover, one promising peptide (pepC) was identified that can be explored in the search for improving Bothrops spp. envenomation treatment.

Reactive Arthritis - A Rare Complication of Intravesical BCG Instillation.

Reactive arthritis (ReA) with the classic triad of arthritis, conjunctivitis and urethritis, previously termed Reiter's syndrome, is a systemic illness, usually induced by genitourinary or gastrointestinal infections. However, it can be a rare complication of intravesical Bacillus Calmette-Guérin instillation (iBCG), a therapy prepared from attenuated strains of Mycobacterium bovis, a common and effective treatment for carcinoma in situ of the bladder (CisB). We report a case of a patient with CisB who developed ReA after iBCG. The symptoms resolved completely with corticosteroids. iBCG was stopped with no recurrence of carcinoma within 2 years. LEARNING POINTS: ReA is an aseptic arthritis, usually triggered by genitourinary or gastrointestinal infections, generally in individuals positive for HLA-B27.Septic arthritis and microcrystalline arthritis can mimic ReA and they must be ruled out with arthrocentesis.ReA may be considered as a complication in patients under iBCG.

Antioxidant effects of different extracts from Melissa officinalis, Matricaria recutita and Cymbopogon citratus.

Considering the important role of oxidative stress in the pathogenesis of several neurological diseases, and the growing evidence of the presence of compounds with antioxidant properties in the plant extracts, the aim of the present study was to investigate the antioxidant capacity of three plants used in Brazil to treat neurological disorders: Melissa officinalis, Matricaria recutita and Cymbopogon citratus. The antioxidant effect of phenolic compounds commonly found in plant extracts, namely, quercetin, gallic acid, quercitrin and rutin was also examined for comparative purposes. Cerebral lipid peroxidation (assessed by TBARS) was induced by iron sulfate (10 microM), sodium nitroprusside (5 microM) or 3-nitropropionic acid (2 mM). Free radical scavenger properties and the chemical composition of plant extracts were assessed by 1'-1' Diphenyl-2' picrylhydrazyl (DPPH) method and by Thin Layer Chromatography (TLC), respectively. M. officinalis aqueous extract caused the highest decrease in TBARS production induced by all tested pro-oxidants. In the DPPH assay, M. officinalis presented also the best antioxidant effect, but, in this case, the antioxidant potencies were similar for the aqueous, methanolic and ethanolic extracts. Among the purified compounds, quercetin had the highest antioxidant activity followed by gallic acid, quercitrin and rutin. In this work, we have demonstrated that the plant extracts could protect against oxidative damage induced by various pro-oxidant agents that induce lipid peroxidation by different process. Thus, plant extracts could inhibit the generation of early chemical reactive species that subsequently initiate lipid peroxidation or, alternatively, they could block a common final pathway in the process of polyunsaturated fatty acids peroxidation. Our study indicates that M. officinalis could be considered an effective agent in the prevention of various neurological diseases associated with oxidative stress.

Osteogenesis imperfect: clinical and epidemiological findings in a series of pediatric patients.

Background: Osteogenesis imperfecta (OI) is the most common hereditary bone disorder with an incidence of one in 10,000-25,000 births. It is caused mainly by mutations in the genes that code for Type I collagen chains. In most cases, it shows an autosomal dominant inheritance pattern. OI is characterized by an increase in bone fragility that leads to frequent fractures, which cause pain, deformity and disability associated with other alterations. The objective of this study was to present the clinical and epidemiological characteristics of a series of pediatric patients diagnosed with OI evaluated at the University of Los Andes. Methods: A series of 37 pediatric cases with diagnosis of OI according to the clinical and radiological classification of sillence is analyzed, which were evaluated in the medical genetics unit of the University of Los Andes consultation between January 2006 and December 2018. Results: Type I was the most frequent OI type, with 31 patients (83.78%). Additionally, the femur was the most affected bone. Blue scleras were the most frequent additional finding in 32 patients (86.49%). Conclusions: OI represents the main reason for consultation of alterations in the skeletal system in the medical genetics unit of the University of Los Andes. Given the broad clinical presentation, the evaluation must be individual and interdisciplinary. Further study will provide timely family genetic counseling.

Introducción: La osteogénesis imperfecta (OI) es el trastorno óseo hereditario más común, con una incidencia de 1 en 10,000 a 25,000 nacimientos. Este trastorno está causado principalmente por mutaciones de los genes que codifican las cadenas del colágeno tipo I. En la mayoría de los casos, se presenta un patrón de herencia autosómico dominante. La OI se caracteriza principalmente por un aumento en la fragilidad ósea que da lugar a fracturas frecuentes que producen dolor, deformidad y discapacidad asociada con otras alteraciones. El objetivo del estudio fue exponer las características clínicas y epidemiológicas de una serie de pacientes pediátricos con diagnóstico de OI evaluados en la Universidad de Los Andes. Métodos: El presente trabajo consiste en el análisis de una serie de 37 casos pediátricos con diagnóstico de OI, de acuerdo a la clasificación clínica y radiológica de Sillence, evaluados en la consulta de la Unidad de Genética Médica de la Universidad de Los Andes, entre enero de 2006 y diciembre de 2018. Resultados: La OI tipo I fue la de presentación más frecuente, con 31 pacientes (83.78%). El fémur fue el hueso más afectado de manera conjunta. Las escleras azules fueron el hallazgo adicional más frecuente, en 32 pacientes (86.49%). Conclusiones: La OI representa el principal motivo de consulta por alteraciones en el sistema esquelético en la Unidad de Genética Médica de la Universidad de Los Andes. Ante la amplia forma clínica de presentación, la evaluación debe ser individual e interdisciplinaria. A través de un estudio más profundo se podrá brindar el oportuno asesoramiento genético familiar.

Felty's syndrome - a rare case of febrile neutropenia.

Felty's syndrome (rheumatoid arthritis with neutropenia and splenomegaly) is a rare condition with poor long-term prognosis, mainly as a result of severe infection risk. An effective treatment strategy has not been developed so far and current treatment options are based upon case reports, small series and clinical experience since no randomized clinical trials are available. The authors describe the case of a 53-year-old female patient with a 14-year history of rheumatoid arthritis presenting with fever, neutropenia and splenomegaly. Broad-spectrum antibiotics and granulocyte colony-stimulating factor were administered with good clinical outcome and low dose methotrexate for disease control was successfully initiated after discharge. We would like to highlight the importance of being aware of this syndrome in the differential diagnosis of long term rheumatoid arthritis patients presenting with febrile neutropenia.

Occam's razor versus Hickam's dictum: two very rare tumours in one single patient.

Occam's razor, the principle that a single explanation is the most likely in medicine, assumes that when a patient has multiple symptoms the clinician seeks a single diagnosis rather than diagnosing multiple and different ones. However, as proposed by Hickam's dictum, sometimes rare different diseases occurred in only one patient. We present a patient with a simultaneous diagnosis of two rare tumours, a cardiac hemangioma (primary cardiac tumour, often misdiagnosed as myxoma) and an appendiceal mucocele (a lesion of the appendix that can be neoplastic or not). A 71-year-old male presented with anorexia, asthenia, fever and weight loss for about one month. During the etiological investigation, a cardiac mass and an appendiceal lesion were detected and both lesions required surgical intervention. Cardiac and abdominal surgeries were uneventful and full recovery was achieved. The histological examination showed a cardiac hemangioma and a neoplastic appendiceal mucocele.

[Clinical, biochemical and molecular findings of propionic acidemia]. / Hallazgos clínicos, bioquímicos y moleculares de la acidemia propiónica: reporte de un caso.

Propionic acidemia is an infrequent disorder with an autosomal recessive inheritance pattern caused by the deficiency of the mitochondrial enzyme propionyl-CoA carboxylase that converts propionyl-CoA to D-methylmalonyl-CoA. We present the case of a male newborn who showed signs of respiratory distress, vomiting and tiredness during feeding. He presented metabolic acidosis, positive serum and urine ketone bodies, hyperammonemia, anemia, thrombocytopenia and hypoproteinemia. The biochemical study by gas chromatography coupled to mass spectrometry in a urine sample was suggestive of propionic acidemia. The molecular study in the PCCA gene found the mutations c.893A>G (p.K298R) in the father and c.937C> T (p.R313X) in the mother. There is a need to establish the diagnosis of this infrequent entity to implement the therapeutic measures available and provide the appropriate genetic counseling.

La acidemia propiónica es un trastorno infrecuente con patrón de herencia autosómico recesivo causado por la deficiencia de la enzima mitocondrial propionil-CoA carboxilasa, que convierte el propionil-CoA a D-metilmalonil-CoA. Se expone el caso de un recién nacido masculino con signos de dificultad respiratoria, vómitos y cansancio durante la alimentación. Presentó acidosis metabólica, cuerpos cetónicos en el suero y la orina positivos, hiperamonemia, anemia, trombocitopenia e hipoproteinemia. El estudio bioquímico por cromatografía de gases acoplada a espectrometría de masas en la muestra de orina fue sugestivo de acidemia propiónica. El estudio molecular en el gen PCCA encontró las mutaciones c.893A>G (p.K298R) en el padre y c.937C>T (p.R313X) en la madre. Existe la necesidad de establecer el diagnóstico de esta entidad infrecuente para implementar las medidas terapéuticas disponibles y aportar el oportuno asesoramiento genético.

[Wolf-Hirschhorn syndrome. Description of five cases characterized by means of single nucleotide polymorphism microarrays]. / Síndrome de Wolf-Hirschhorn. Descripción de cinco casos caracterizados por microarrays de polimorfismos de nucleótido único.

Wolf-Hirschhorn syndrome is a polymalformative entity due to the microdeletion in the distal region of the short arm of chromosome 4 (4p16.3), which produces a series of clinical manifestations that can vary depending on the type and size of the genetic defect in this contiguous gene syndrome. Five patients are presented, three of them female, all with the primary clinical findings, characterized by "Greek warrior helmet appearance" facial feature, growth retardation and psychomotor development delay. In addition to the partial deletion in the distal region of the short arm of chromosome 4, two additional genetic alterations were found in two patients, through the use of single nucleotide polymorphism arrays. The clinical characteristics of Wolf-Hirschhorn syndrome are highlighted in order to guide the diagnosis, provide interdisciplinary medical care and, through its confirmation, provide adequate family genetic counseling.

El síndrome de Wolf-Hirschhorn es una entidad polimalformativa debida a la microdeleción en la región distal del brazo corto del cromosoma 4 (4p16.3), el cual produce una serie de manifestaciones clínicas, que pueden variar dependiendo del tipo y tamaño del defecto genético en este síndrome de genes contiguos. Se presentan cinco pacientes, tres de ellos de sexo femenino, todos con los hallazgos clínicos primordiales, con rasgo facial característico de "apariencia en casco de guerrero griego", retraso en el crecimiento y del desarrollo psicomotor. Además de la deleción parcial en la región distal del brazo corto del cromosoma 4, en dos pacientes, se encontraron alteraciones genéticas adicionales, mediante el uso de microarrays de polimorfismos de nucleótido único. Se resaltan las características clínicas del síndrome de Wolf-Hirschhorn con la finalidad de orientar el diagnóstico, brindar una atención médica interdisciplinaria y, a través de su confirmación, brindar un adecuado asesoramiento genético familiar.

[Subcutaneous Emphysema and Pneumomediastinum During a Tooth Extraction].

Subcutaneous emphysema is a possible but rare complication after dental procedures. The condition should be distinguished from other situations, such as hematoma, allergic reaction or angioedema, and infection. We describe the case of a 20-year-old puerperal woman, with multiple dental caries, who developed cervicofacial subcutaneous emphysema complicated by pneumomediastinum, following an incomplete extraction of the lower right second molar. This was diagnosed clinically and through imaging tests, and the situation resolved after hospital admission, with antibiotics and close monitoring. The case underlines the need to diagnose and treat this complication early, because of the risk of airway compromise, air embolism, infection, sepsis and death.

O enfisema subcutâneo cervicofacial e mediastínico é uma possível complicação, rara, após procedimentos dentários. Deve-se distinguir de outras situações como o hematoma, reação alérgica ou angioedema e infeção. Descreve-se o caso de uma puérpera de 20 anos com múltiplas cáries dentárias, que desenvolveu enfisema subcutâneo cervicofacial, complicado de pneumomediastino, após extração incompleta do segundo molar inferior direito. O diagnóstico da complicação foi clínico e imagiológico e a situação resolveu sob vigilância, com antibioterapia, em internamento. O caso pretende chamar a atenção para a necessidade de se diagnosticar e tratar precocemente esta complicação, devido ao risco de compromisso da via aérea, embolia gasosa, infeção, sépsis e morte.

[Clinical and molecular study in a family with cleidocranial dysplasia]. / Estudio clínico y molecular en una familia con displasia cleidocraneal.

Cleidocranial dysplasia is an uncommon bone dysplasia with an autosomal dominant inheritance pattern characterized by short stature, large fontanels, midface hypoplasia, absence or hypoplasia of clavicles and orodental alterations. This is Estudio clínico y molecular en una familia con displasia cleidocraneal Clinical and molecular study in a family with cleidocranial dysplasia produced by mutations in the RUNX2 gene located at 6p21.1. We report two male adolescents (cousins), with cleidocranial dysplasia who presented a heterozygous missense mutation (c.674G> A, p.R225Q) in the RUNX2 gene, characterized by severe phenotype, such as absent clavicles, but with variation in the delayed fontanel closure, dental abnormalities (anomalies in shape and number) and scoliosis, thus demonstrating intrafamilial variation in these patients with the same genotype.

La displasia cleidocraneal es una displasia ósea infrecuente con patrón de herencia autosómico dominante, que se caracteriza por presentar talla baja, fontanelas amplias, hipoplasia mediofacial, ausencia o hipoplasia de clavículas y alteraciones orodentales. Es producida por mutaciones en el gen RUNX2 localizado en 6p21.1. Se presentan dos adolescentes masculinos (primos hermanos) con displasia cleidocraneal, los cuales mostraron mutación heterocigota, cambio de sentido (c.674G>A, p.R225Q) en el gen RUNX2, caracterizados por presentar fenotipo grave, como ausencia de clavículas, pero con variación en el retardo en el cierre de fontanelas, alteraciones dentales (anomalías en forma y número) y escoliosis, por lo que se demuestra la variación intrafamiliar en estos pacientes con el mismo genotipo.

[Mosaic trisomy 18. Series of cases]. / Trisomía 18 en mosaico. Serie de casos.

Trisomy 18 syndrome (T18) is a clinical and genetic disorder, which has a full extra chromosome 18 in each cell, variant that is called free trisomy. In addition, it can occur in partial and mosaic form. It is characterized by intrauterine growth restriction, psychomotor and mental retardation, characteristic craniofacial findings, congenital heart disease, hypoplastic pelvis, clenched hand and rocker-bottom foot, among others. The mosaic T18 occurs when cells with T18 and normal cell lines exist in the same individual and correspond to 5% of cases. Trisomía 18 en mosaico. Serie de casos Mosaic trisomy 18. Series of cases The phenotypic findings are highly variable and no correlation was evident between the percentage of trisomic cells and the findings found. The aim of this report is to present a series of five cases of mosaic T18 with emphasis on clinical aspects in order to guide an interdisciplinary adequate medical care and provide timely genetic counseling.

El síndrome de la trisomía 18 es un trastorno clínico y genético, el cual presenta un cromosoma 18 extra completo en cada célula, variante que se denomina trisomía libre. Además, puede ocurrir en la forma parcial y mosaico. Clínicamente, se caracteriza por retardo del crecimiento intrauterino, del desarrollo psicomotor y mental, hallazgos craneofaciales característicos, cardiopatía congénita, pelvis hipoplásica, manos empuñadas y pies en mecedora, entre otros. La trisomía 18 en mosaico se presenta cuando células con trisomía del cromosoma 18 y líneas celulares normales existen en un mismo individuo, y corresponde al 5% de los casos. Los hallazgos fenotípicos son muy variables y no se evidencia una correlación entre el porcentaje de células trisómicas y los hallazgos encontrados. El objetivo de este informe es presentar una serie de cinco casos de trisomía 18 en mosaico. Se hace énfasis en los aspectos clínicos con la finalidad de orientar una adecuada atención médica interdisciplinaria y brindar un oportuno asesoramiento genético.

Design, Synthesis and Biological Evaluation of Betulinic Acid Derivatives as New Antitumor Agents for Leukemia.

BACKGROUND: Chronic myeloid leukemia (CML) is currently treated with imatinib, a Bcr-Abl inhibitor. However, resistance to this drug usually develops over time. Triptolide, a diterpenoid triepoxide, has been shown active against CML cells resistant to imatinib, acting mainly on the level of Bcr-Abl transcription inhibition. OBJECTIVE: Here, we used the triterpene betulinic acid, a known proteasome inhibitor with potential antileukemic activity, as a scaffold for the generation of analogues with predicted triptolide biological activity. METHOD: Betulinic acid derivatives were designed based on the structure-activity relationship of triptolide and evaluated for their cytotoxic effects in CML cells, lymphocytes and human keratinocytes (HaCaT), as well as against the proteasome complex. The main modification performed on betulinic acid was fluorination at C-28 and epoxidation, both of which are responsible for enhancing activity of triptolide. A total of 10 compounds were obtained: 6 previously described and 4 novel compounds. The cytotoxic activity over a CML cell line (K562) was assessed using flow cytometry and compared to lymphocytes and HaCaT. RESULT: The results show that betulinic acid was the most cytotoxic compound against CML cells, showing a good selectivity index for cancer over normal cells. The most important trend for the activity in betulinic acid derivatives is the presence of a free hydroxyl group at C-3 and a carboxyl group at C-28. Results also indicated that the epoxide is important for enhancing the activity, while modification at C-28 worsens the activity. CONCLUSION: Proteasome inhibition assays suggest that proteasome is the main target for betulinic acid and its derivatives.

Larvicidal activity of natural and modified triterpenoids against Aedes aegypti (Diptera: Culicidae).

BACKGROUND: Insecticide resistance to commonly used substances demands new molecules for the chemical control of the dengue vector Aedes aegypti. Because natural product sources have been an alternative to obtain larvicidal compounds, the aim of this study was to evaluate the triterpenoids betulinic (BA) and ursolic (UA) acids and their semi-synthetic derivatives against larval Ae. aegypti. BA, UA, ten derivatives modified at the C-3 position and a positive control (diflubenzuron) were evaluated. Larvicidal assays were carried out with early fourth-instar larvae, and mortality was observed between 48 and 96 h. Doses from 200 to 10 ppm were used to calculate lethal concentrations (LCs). RESULTS: Natural compounds, i.e. UA and BA, had the lowest LCs (LC50 of 112 and 142 ppm respectively), except for the modified compound 2b (LC50 of 130 ppm). Larvicidal activity increased significantly from 48 to 96 h for all the compounds evaluated, ranging from 20 to 50% after 48 h and from 48 to 76% after 96 h. Some derivatives, e.g. 2a and 2d, had up to a three-fold larvicidal activity increase from 48 to 96 h. CONCLUSION: BA, UA and their derivatives showed larvicidal activity against Ae. aegypti larvae, increasing significantly from 48 to 96 h. The presence of a hydroxyl group is essential for larvicidal potential in these triterpenoids. © 2016 Society of Chemical Industry.