The influence of massive jejunectomy on endocrine pancreas of diabetic Goto-Kakizaki.

OBJECTIVE: Several bariatric surgeries have been related to the T2DM improvement in obese patients. Despite the different mechanism invoked for this improvement, many evidences showed that the pancreas cellularity is conditioned for the homeostatic physiological changes after these surgeries. Many authors reported the changes in beta-cell mass after some surgeries in healthy rats. We purpose to analyze the changes in ß-cell cellularity and ß-cell-mass after a severe malabsorptive surgical method. Thus, we studied several parameters of the islet morphometric composition after a massive jejunal resection. MATERIALS AND METHODS: We employed Goto-Kakizaki diabetic non-obese rats, which underwent the 50% resection of middle portion of the jejunum versus a control group. After 3 months, rats were sacrificed and pancreas was immunohistochemicaly studied. RESULTS: The ß-cell mass was analyzed and several parameters about the endocrine islet size distribution were studied. We report an increase of ß-cell mass in massive resection surgical group versus controls. The islet distribution was significant different between both groups. Endocrine islets of surgical group were bigger with a different cellular distribution. CONCLUSION: According to the enteroendocrine changes related to surgeries in jejunum, as in other gastrointestinal portions, the cellularity of islets changes as an adaptive process to glycemic demands.

OBJETIVO: Varias técnicas quirúrgicas bariátricas han sido relacionadas con el mejoramiento de la T2DM en pacientes obesos. Se han invocado distintos mecanismos de porqué se da este mejoramiento y muchas evidencias apuntan a que la celularidad del páncreas cambia por las condiciones fisiológicas tras estas cirugías. Se han publicado cambios en la celularidad beta en ratas sanas sometidas a estos procesos. Y nos proponemos observar dichos cambios en ratas diabéticas tras una resección jejunal masiva. Estudiamos varios parámetros sobre la masa beta y la morfometría de los islotes, que indiquen los procesos celulares que han tenido lugar. MATERIAL Y METODO: Empleamos Goto-Kakizaki, un modelo de rata diabética no obesa, a la que se sometió a una resección del 50%de la poción media del yeyuno. Tras tres meses de supervivencia, las ratas se estudiaron los páncreas mediante inmunocitoquímica. RESULTADOS: Mostramos un incremento de la masa beta en las ratas resecadas frente a los controles. La distribución de islotes fue significativamente distinta entre los grupos, donde los islotes eran mayores en las ratas diabéticas. CONCLUSIÓN: Los cambios glucémicos tras las resecciones masivas yeyunales cambian la celularidad del páncreas como una muestra de la capacidad adaptativa del mismo a las modificaciones.

A Comparative DFT Study on Process Control Agents in the Mechanochemical Synthesis of PbTe.

A process control agent is an organic additive used to regulate the balance between fracturing and mechanical kneading, which control the size of the as-milled particles. Tributyl phosphate (TBP) is evaluated to act as surface modifier of PbTe, and it is compared with the results obtained using formaldehyde (CH2O). In order to elucidate the nature of the interaction between TBP and the PbTe surface, global and local descriptors were calculated via the density functional theory. First, TBP and CH2O molecules are structurally optimized. Then, vertical ionization energies as well as vertical electron affinities are calculated to elucidate how both molecules behave energetically against removal and electron gain, respectively. The results were compared with those obtained from the electrostatic potential mapped on the van der Waals isosurface. It is inferred that the theoretical insights are useful to propose adsorption modes of TBP and CH2O on the PbTe surface, which are usable to rationalize the facets exposed by PbTe after the surface treatment. The optimized structures of the compound systems showed a close correlation between the surface energy shift (Δγ) and the PbTe facets exhibited. Finally, a Wulff construction was built to compare the usage of TBP and CH2O molecules in PbTe morphology.

CO2 Adsorption on PtCu Sub-Nanoclusters Deposited on Pyridinic N-Doped Graphene: A DFT Investigation.

To reduce the CO2 concentration in the atmosphere, its conversion to different value-added chemicals plays a very important role. Nevertheless, the stable nature of this molecule limits its conversion. Therefore, the design of highly efficient and selective catalysts for the conversion of CO2 to value-added chemicals is required. Hence, in this work, the CO2 adsorption on Pt4-xCux (x = 0-4) sub-nanoclusters deposited on pyridinic N-doped graphene (PNG) was studied using the density functional theory. First, the stability of Pt4-xCux (x = 0-4) sub-nanoclusters supported on PNG was analyzed. Subsequently, the CO2 adsorption on Pt4-xCux (x = 0-4) sub-nanoclusters deposited on PNG was computed. According to the binding energies of the Pt4-xCux (x = 0-4) sub-nanoclusters on PNG, it was observed that PNG is a good material to stabilize the Pt4-xCux (x = 0-4) sub-nanoclusters. In addition, charge transfer occurred from Pt4-xCux (x = 0-4) sub-nanoclusters to the PNG. When the CO2 molecule was adsorbed on the Pt4-xCux (x = 0-4) sub-nanoclusters supported on the PNG, the CO2 underwent a bond length elongation and variations in what bending angle is concerned. In addition, the charge transfer from Pt4-xCux (x = 0-4) sub-nanoclusters supported on PNG to the CO2 molecule was observed, which suggests the activation of the CO2 molecule. These results proved that Pt4-xCux (x = 0-4) sub-nanoclusters supported on PNG are adequate candidates for CO2 adsorption and activation.

COVID-19 Pandemic and its Impact on the Management of Head and Neck Cancer in the Spanish Healthcare System.

Introduction Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has represented a major challenge for healthcare systems worldwide, changing the habits of physicians. A reorganization of healthcare activity has been necessary, limiting surgical activity to essential cases (emergencies and oncology), and improving the distribution of health resources. Objective To analyze the impact of the COVID-19 pandemic on head and neck cancer surgery management in Spain. Methods A cross-sectional study, through an anonymous and voluntary online survey distributed to 76 Spanish otorhinolaryngology departments. Results A total of 44 centers completed the survey, 65.9% of which were high-volume. A total of 45.5% of them had to stop high-priority surgery and 54.5% of head and neck surgeons were relocated outside their scope of practice. Surgeons reported not feeling safe during their usual practice, with a decrease to a 25% of airway procedures. A total of 29.5% were "forced" to deviate from the "standard of care" due to the epidemiological situation. Conclusions Approximately half of the departments decreased their activity, not treating their patients on a regular basis, and surgeons were reassigned to other tasks. It seems necessary that the head and neck surgeons balance infection risk with patient care. The consequences of the reported delays and changes in daily practice should be evaluated in the future in order to understand the real impact of the pandemic on the survival of head and neck cancer patients.

Recovery of sciatic nerve with complete transection in rats treated with leuprolide acetate: A gonadotropin-releasing hormone agonist.

It has been reported that the Gonadotropin-releasing hormone (GnRH) and its agonist leuprolide acetate (LA) can act as promoters of nerve regeneration. The aim of this study is to evaluate the effect of LA in a complete transection model. Sciatic nerve injury (SNI) was performed using a complete nerve transection and immediately repaired by epineural sutures. Rats were divided into three groups: SHAM, SNI treated with LA (SNI + LA) or saline solution (SNI + SS) for 5 weeks. Sciatic nerve regeneration was evaluated by kinematic gait analyzes, electrophysiological, morphological and biochemical tests. SNI + LA group had a functional recovery in kinematic gait, an increase in ankle angle value and a faster walking speed, compound muscle action potential amplitude, nerve conduction velocity (NCV). Furthermore, the number of myelinated axons and microtubule-associated protein 2 (MAP-2) expression were also higher compared to SS group. In conclusion, LA treatment improves of gait, walking speed, NCV, axons morphometry and MAP-2 expression in rats with sciatic nerve complete transection. These results suggest that LA can be a potential treatment for peripheral nerve injuries.

Polymer films containing chemically anchored diazonium salts with long-term stability as colorimetric sensors.

We have prepared polymeric films as easy-to-handle sensory materials for the colorimetric detection and quantification of phenol derivatives (phenols) in water. Phenols in water resources result from their presence in pesticides and fungicides, among other goods, and are harmful ecotoxins. Colorless polymeric films with pendant diazonium groups attached to the acrylic polymer structure were designed and prepared for use as sensory matrices to detect phenol-derived species in water. Upon dipping the sensory films into aqueous media, the material swells, and if phenols are present, they react with the diazonium groups of the polymer to render a highly colored azo group, giving rise to the recognition phenomenon. The color development can be visually followed for a qualitative determination of phenols. Additionally, quantitative analysis can be performed by two different techniques: a) by using a UV-vis spectrophotometer (limit of detection of 0.12 ppm for 2-phenylphenol) and/or b) by using a smartphone with subsequent RGB analysis (limit of detection of 30 ppb for 2-phenylphenol).

Selective Serotonin Reuptake Inhibitors Reduce Longitudinal Growth in Risperidone-Treated Boys.

OBJECTIVES: To examine whether selective serotonin reuptake inhibitors (SSRIs) inhibit longitudinal growth in children and adolescents, particularly in the early stages of puberty, using a sample of convenience comprising risperidone-treated boys. STUDY DESIGN: Data from four clinic-based studies in risperidone-treated 5- to 17-year-old boys with no general medical conditions were combined for this analysis. Anthropometric measurements and psychotropic treatment history were extracted from the medical and pharmacy records. Linear mixed effects regression analyses examined the association between SSRI use and change in age-sex-specific height and body mass index z scores, after adjusting for relevant confounders. RESULTS: Risperidone-treated boys (n = 267; age: 12.7 ± 2.7 years), 71% of whom had ever taken an SSRI, contributed to the analysis. After adjusting for age, psychostimulant and antipsychotic use, and time in the study, both the duration of SSRI use as well as the cumulative dose were inversely associated with height z score after age 11 years (P < .0001). After adjusting for baseline height, duration of SSRI use was most strongly inversely associated with height z score in Tanner stages 3 and 4 boys who took SSRIs continuously (r = -0.69, P < .009). No association was observed with body mass index z score. CONCLUSIONS: In risperidone-treated boys, SSRI use is associated with reduced longitudinal growth, particularly in those undergoing puberty. Whether adult height or other metabolic or psychological outcomes are affected remains to be determined.

The Coffee Berry Borer (Coleoptera: Curculionidae) in Puerto Rico: Distribution, Infestation, and Population per Fruit.

The coffee berry borer (CBB) (Hypothenemus hampei: Ferrar) was first detected in Puerto Rico in 2007. Its distribution since then has been extensive, but not extensively documented. An island-wide survey was carried out from August to November 2014 (the coffee production season) to assess CBB distribution, infestation, and population per fruit. The CBB was well-established throughout the coffee-growing area of Puerto Rico, but was not evenly distributed. Infestation (or percentages of fruits perforated) in sites sampled ranged from 0 to 95%, and CBB number per infested fruit varied from 1 to 34 individuals. CBB infestation and total population per fruit were positively correlated with altitude. Highest infestation and total population were observed in sites located >400 masl; most of the coffee-producing area in Puerto Rico is above this altitude. Coffea arabica (L.) had higher CBB infestation and population per fruit than Coffea canephora (Pierre ex A. Froehner) (robusta coffee). Based on these results, management tools should be implemented to mitigate the severe damage that CBB is causing in Puerto Rico. These management tools should include the removal of all fruits that remain on the plants after harvest and the use of the entomopathogenic fungus Beauveria bassiana (Balls.) Vuill. for biocontrol, especially on coffee farms at higher elevations.

A new caprellid species (Crustacea: Amphipoda: Senticaudata) from Brazil.

A new species of caprellid, Pseudaeginella arraialensis, is described from Arraial do Cabo, Rio de Janeiro, Brazil. Abundant material was collected in Praia do Forno, associated to hydroids and algae of natural rocky substrata and fouling communities of artificial floating structures. The new species can be distinguished easily from the remaining species in the genus mainly by the pattern of dorsal projections, and by the setose antennae and gnathopod 2 in males. The dietary analysis revealed that the species is omnivorous, with a high contribution of small crustaceans in its diet. Detailed figures showing ontogenetic development and intraspecific variation of P. arraialensis are also included.

New genus and new species of Caprellidae (Crustacea: Peracarida: Amphipoda) from the mesophotic coral ecosystems of Puerto Rico and St. Croix, Caribbean Sea.

A new genus and two new species are described based on material collected from the mesophotic coral ecosystems of the U.S. Caribbean. The new genus Borikenella can be distinguished from other related genera such as Pseudaeginella, Paradeutella, Aciconula and Deutella by the combination of the following characters: pereopods 3 and 4 three-articulate, pereopods 5-7 six-articulate, mandible molar present, palp of the mandible with a setal formula 1-x-0, abdomen without appendages. The new species Liropus gurui, can be distinguished from the closely related L. japonicus mainly by the lack of anteroventral margin extended forward in pereonite 3, the lack of cleft and serration in the propodus of gnathopod 2, the longer pereopod 3 and the larger abdominal appendages.

A performance/cost evaluation for a GPU-based drug discovery application on volunteer computing.

Bioinformatics is an interdisciplinary research field that develops tools for the analysis of large biological databases, and, thus, the use of high performance computing (HPC) platforms is mandatory for the generation of useful biological knowledge. The latest generation of graphics processing units (GPUs) has democratized the use of HPC as they push desktop computers to cluster-level performance. Many applications within this field have been developed to leverage these powerful and low-cost architectures. However, these applications still need to scale to larger GPU-based systems to enable remarkable advances in the fields of healthcare, drug discovery, genome research, etc. The inclusion of GPUs in HPC systems exacerbates power and temperature issues, increasing the total cost of ownership (TCO). This paper explores the benefits of volunteer computing to scale bioinformatics applications as an alternative to own large GPU-based local infrastructures. We use as a benchmark a GPU-based drug discovery application called BINDSURF that their computational requirements go beyond a single desktop machine. Volunteer computing is presented as a cheap and valid HPC system for those bioinformatics applications that need to process huge amounts of data and where the response time is not a critical factor.

The Panama Canal and the transoceanic dispersal of marine invertebrates: evaluation of the introduced amphipod Paracaprella pusilla Mayer, 1890 in the Pacific Ocean.

Although the Panama Canal is one of the major corridors for shipping and potential dispersal of marine invaders in the tropics, little is known about the effect that the Canal has had on the distribution of marine biota. In this study, we (a) document the existence of established populations of the Western Atlantic caprellid amphipod Paracaprella pusilla, Mayer, 1890 for the first time at the Pacific entrance to the Canal, (b) review its distribution in the Pacific Ocean, and (c) evaluate possible mechanisms of introduction. The confirmed distribution of P. pusilla in the Pacific Ocean is limited to Australia, Hawaii, and Panama, despite earlier published reports from Chile and China. Laboratory experiments demonstrated intolerance of P. pusilla to freshwater, causing 100% mortality, and suggest invasion of the Pacific coast of Panama occurred through the Canal via ships' ballast water or by secondary spread via ships (ballast water or hull fouling) from another Pacific region.

Profilaxis de fracturas osteoporóticas: ni caerse, ni dejarse caer / Prophylaxie des fractures ostéoporotiques: ne pas tomber ni se négliger / Prophylaxis in ostoporotic structures: neither drop nor let yourself drop

La interacción de los conceptos caerse y dejarse caer en la tercera edad, así como el conocimiento de las causas y consecuencias de uno y otro, resultan esenciales en la prevención de las fracturas poróticas. El objetivo de este trabajo es mostrar los distintos factores que al actuar sobre el sistema osteomioarticular conducen a caerse y provocar estas fracturas, y qué se debe hacer para evitarlas. Se concluye que no caerse ni dejarse caer, no es una meta sino elementos del viaje de la vida para hacernos, aunque viejos, más libres(AU)

The interaction between the concepts to drop and let yourself drop in the elderly as well as the knowledge of the causes and consequences of these facts are fundamental in the prevention of porous fractures. Therefore, the aim of this work is to show the different factors that, acting on the osteomyoarticular system, lead to drops and cause these types of fractures and what to do to avoid them. It is concluded that, neither drop nor let yourself drop, is not a goal but elements of our life journey that make us be older, but freer(AU)

L'interaction des concepts «tomber¼ et se négliger chez les personnes âgées, ainsi que la connaissance des causes et des conséquences d'un concept et d'un autre, sont associées à la prévention des fractures ostéoporotiques. Le but de ce travail est donc de montrer les différents facteurs conduisant aux chutes et aux fractures, et comment les éviter. On conclu que la notion «ne pas tomber ni se négliger¼ n'est pas un but, mais des éléments essentiels nous rendant plus indépendants au cours de la vie(AU)

Intravitreal bevacizumab for peripapillary subretinal neovascular membrane associated to papilledema: a case report.

The purpose of this report is to document the use of bevacizumab as treatment of peripapillary subretinal neovascular membrane associated to idiopathic intracranial hypertension. This case reports a 31-year-old obese female with chronic papilledema due to idiopathic intracranial hypertension that developed an acute submacular hemorrhage due to a choroidal neovascular membrane in her left eye. Two separate intravitreal injections of bevacizumab (1.25 mg/0.5 ml) were administered with six weeks apart. Fourteen weeks after the initial injection her visual acuity improved to 20/40 in her left eye with associated angiographic resolution of the hemorrhage. Bevacizumab appears to be an effective option for patients who have subretinal neovascular membranes due to papilledema. Although choroidal neovascularization may have different pathogenic mechanisms, our case report demonstrates encouraging results without adverse ocular or systemic side effects.

Analysis of thyroglobulin gene polymorphisms in patients with autoimmune thyroiditis.

The autoimmune thyroid disease is a complex disorder caused by a combination of genetic susceptibility and environmental factors, which are believed to initiate the autoimmune response to thyroid antigens. Identification of the susceptibility genes has found that unique and diverse genetic factors are in association with Graves' disease and autoimmune thyroiditis. The thyroglobulin gene is an identified thyroid-specific gene associated to autoimmune thyroid disease and, principally, with autoimmune thyroiditis. The aim of this work was to test for evidence of allelic association between autoimmune thyroiditis and thyroglobulin polymorphism markers. We studied six polymorphisms distributed throughout all the thyroglobulin gene: four microsatellites (Tgms1, Tgms2, TGrI29 and TGrI30), one insertion/deletion (Indel) polymorphism (IndelTG-IVS18) and one exonic single nucleotide polymorphism (SNP) (c.7589G>A) in 122 patients with autoimmune thyroiditis compared with 100 non-related normal subjects. No differences in allele and genotype distribution were observed between autoimmune thyroiditis cases and controls for Tgms1, Tgms2, TGrI30, IndelTG-IVS18 and c.7589G>A. However, when we analyzed the patients with the TGrI29 microsatellite we found a significant association between the 199-bp allele and AT (33.7% vs. 24.5% in control group) (P = 0.0372). In addition, a higher prevalence of the 201-bp allele has been observed in control subjects (47.5% vs. 38.1% in patients group), although not statistically significant (P = 0.0536). Our work shows the association between the thyroglobulin gene and autoimmune thyroiditis and reinforce that thyroglobulin is a thyroid-specific susceptibility gene for this disease.

Experiência inicial em Málaga(Espanha) com prótese aórtica CoreValve para tratamento de estenose aórtica sintomática grave / Malaga(Spain)early experience with the CoreValve aortic prosthesis for the treatment of severe symptomatic aortic stenosis

Introdução: A prevalência de estenose aórtica grave vem crescendo em decorrência do aumento da expectativa de vida. Alguns pacientes não se beneficiam do tratamento cirúrgico por causa das comorbidades associadas. Apresentamos os resultados de nossa experiência no tratamento percutâneo da estenose aórtica. Método: Estudo prospectivo, realizado entre abril de 2008 e fevereiro de 2009, em que 31 pacientes consecutivos com estenose aórtica grave sintomática e que apresentavam alto risco cirúrgico foram tratados com a prótese aórtica CoreValve. Todos os procedimentos foram realizados com anestesia local. Em 29 casos a via de acesso foi a artéria femoral, com introdutor 18 F, a punção femoral foi fechada com Prostar 10 F, e em 2 pacientes a artéria subclávia esquerda foi a via de acesso. Resultados: A média de idade foi de 77,8 ± 8,9anos e o EuroSCORE logístico médio foi de 17,5 ± 12,6%. O sucesso do implante foi de 100%. O gradiente de pico a pico após o implante desapareceu. Nenhum paciente apresentou insuficiência aórtica residual > grau 2 de Sellers. A mortalidade aos 30 dias foi de 3,2%. Foram necessários marca-passos definitivos em 31% dos pacientes. Depois de acompanhamento médio de 154 ± 90 dias, foram registrados 4 óbitos (1 morte súbita e 3 por causas não-cardíacas). Conclusões: O implante percutâneo da prótese aórtica CoreValve como tratamento alternativo da estenose aórtica grave em pacientes com alto risco cirúrgico é factível e seguro, com elevada taxa de êxito no procedimento e porcentual de complicações abaixo do esperado em função do risco cirúrgico estimado com o EuroSCORE.

Background: The prevalence of severe aortic stenosis is increasing with the rise in life expectancy. Some patients cannot undergo surgical treatment of aortic stenosis due to associated disorders. We present the results of our experience with the percutaneous treatment of aortic stenosis as an alternative to surgery in high-risk patients. Methods: This prospective cohort study included 31 consecutive high surgical risk patients with severe and symptomatic aortic stenosis treated with a CoreValve aortic prosthesis from April 2008 to February 2009. All the procedures were undertaken with local anesthesia. In 29 patients we used a femoral artery access, with an 18 F introducer, closing the femoral puncture with a 10 F Prostar, and in two patients the access was via the left subclavian artery. Results: The mean age of the patients was 77.8 ± 8.9 years and the mean logistic EuroSCORE was 17.5 ± 12.6%. The implant was successful in 100% of cases. The peak-to-peak gradient after the implant disappeared. No patient had residual aortic insufficiency Sellers' grade > 2. One-month mortality was 3.2%. A definitive pacemaker was required in 31% of the patients. After a mean follow-up of 154 ± 90 days there were four deaths (1 sudden death and 3 for noncardiac causes). Conclusions: Percutaneous implantation of the CoreValve aortic prosthesis as an alternative treatment for severe aortic stenosis in high surgical risk patients is feasible and safe, with a high success rate for the procedure and a percentage of complications below the expected for the surgical risk, as estimated by the EuroSCORE.

Acute and repeated effects of three organophosphorus pesticides on the acquisition and retention of an instrumental learning task in rats.

The effects of organophosphorus pesticides on higher functions of the central nervous system are not well understood yet. As a first approach, the acute and repeated effects of three organophosphorus pesticides on learning and memory capabilities of behaving adult rats were studied here. Prior to training, animals received acute or repeated (5-day, 15-day, and 30-day) doses of diazinon, malathion, or fenitrothion. Animals were trained with an operant conditioning test, using a fixed-interval (FI 2 min) paradigm. Fifteen days later, animals were tested for retention of the learned task. Specific modifications in some selected behavioral displays were also quantified across the training process. Although their motor behaviors were not affected, treated animals required longer times for the acquisition of the fixed-interval test than did controls. As opposed to controls, not all (45.8% for diazinon, 66.6% for malathion, and 62.5% for fenitrothion) treated animals reached criterion during the retention test. Specific behaviors, such as grooming, rearing, exploratory whisking, and freezing, were modified at different levels by some (or all) of the three organophosphorus pesticides. According to these results, the three organophosphorus pesticides used here affected the acquisition and, mainly, the retention of instrumental conditioning, using a fixed-interval paradigm. The presentation of some specific behavioral displays was also modified in treated animals.

A new case of congenital goiter with hypothyroidism caused by a homozygous p.R277X mutation in the exon 7 of the thyroglobulin gene: a mutational hot spot could explain the recurrence of this mutation.

Identification of thyroglobulin (TG) gene mutations may provide insight into the structure-function relationship. In this study, we have performed molecular studies in a patient with congenital goiter, hypothyroidism, and impairment of TG synthesis. Genomic DNA sequencing revealed a homozygous c.886C-->T mutation in exon 7, resulting in a premature stop codon at amino acid 277 (p.R277X). The same nonsense mutation had been reported previously in two Brazilian families with multiple occurrence of congenital hypothyroidism with goiter. We compared the insertion/deletion polymorphism in intron 18, microsatellites (Tgm1, Tgm2, TGrI29, and TGrI30), and exonic single-nucleotide polymorphism haplotypes identified in the patient with a member of the previously reported family, who also carry the mutation as a compound heterozygous mutation. The single-nucleotide polymorphism and microsatellite analysis revealed that the two affected individuals do not share a common TG allele. This suggests that the p.R277X mutation is a mutational hot spot. No difference in either splicing or abundance of the amplified product was detected by RT-PCR, excluding that an alternative splicing mechanism, by skipping of exon 7, would restore the normal reading frame. In conclusion, we report a new case of congenital goiter and hypothyroidism caused by a p.R277X mutation in the TG gene. Moreover, we show that nucleotide 886 is a mutational hot spot that explains the recurrence of this mutation.

Prevención de la infección por el complejo Mycobacterium avium. ¿Una necesidad en nuestros pacientes con SIDA? / Prevention of infection due to Mycobacterium avium complex. A need in our AIDS patients?

Antecedentes: el complejo Mycobacterium avium (CMA) está compuesto por dos especies que poseen poca virulencia en el huésped normal, ya que la inmunidad celular da protección. Objetivo: conocer la frecuencia de la infección diseminada por el complejo Mycobacterium avium en nuestra población de pacientes con SIDA. Material y métodos: se estudiaron todos los pacientes que tuvieron cuadro clínico sugestivo y linfocitos CD4 < 200 células/mm3; también se les efectuó cultivo de médula ósea para procesarse en medio de Lowenstein Jensen. El grupo total estuvo constituido por 33 pacientes. Resultados: en ningún caso se aisló la micobacteria después de doce semanas de incubación. Dos enfermos (6 por ciento) fallecieron debido a sarcoma de Kaposi y otras infecciones oportunistas, y 31 individuos (94 por ciento) se encontraban en buenas condiciones después de seis meses de seguimiento. Conclusiones: la infección diseminada por el complejo Mycobacterium avium no es común en nuestro medio, por lo cual, al parecer, la profilaxis rutinaria no es imprescindible.