Browsing by Autor "Mayra Pérez"

Now showing 1 - 7 of 7

Assessment of the Sulfamethoxazole mobility in natural soils and of the risk of contamination of water resources at the catchment scale
(Elsevier BV, 2019) Denisse Archundia; Céline Duwig; Lorenzo Spadini; Marie‐Christine Morel; B. Prado; Mayra Pérez; Vladimir Orsag; Jean Martins
Sulfamethoxazole (SMX) is one of the antibiotics most commonly detected in aquatic and terrestrial environments and is still widely used, especially in low income countries. SMX is assumed to be highly mobile in soils due to its intrinsic molecular properties. Ten soils with contrasting properties and representative of the catchment soil types and land uses were collected throughout the watershed, which undergoes very rapid urban development. SMX displacement experiments were carried out in repacked columns of the 10 soils to explore SMX reactive transfer (mobility and reactivity) in order to assess the contamination risk of water resources in the context of the Bolivian Altiplano. Relevant sorption processes were identified by modelling (HYDRUS-1D) considering different sorption concepts. SMX mobility was best simulated when considering irreversible sorption as well as instantaneous and rate-limited reversible sorption, depending on the soil type. SMX mobility appeared lower in soils located upstream of the watershed (organic and acidic soils - Regosol) in relation with a higher adsorption capacity compared to the soils located downstream (lower organic carbon content - Cambisol). By combining soil column experiments and soil profiles description, this study suggests that SMX can be classified as a moderately to highly mobile compound in the studied watershed, depending principally on soil properties such as pH and OC. Potential risks of surface and groundwater pollution by SMX were thus identified in the lower part of the studied catchment, threatening Lake Titicaca water quality.
Eficacia y seguridad terapeutica del apafill-g™ en reparacion osea periapical mediante la vía endodontica
(2013) Mayra Pérez; Leyanis Valdés; L. F. R. Garcia; M.E. Vázquez Fernández; Daysi Márquez; J. A. Delgado; Rosa Mayelín Guerra Bretaña; Amisell Almirall; Yaidelín Peña; Gladys Josefina Velazco Viloria
Apical bone lesions in the tooth are mainly caused by pulpal disease. The restoration of these lesions goes from the radicular pulp treatment with calcium hydroxide until surgery. The aim of this study was to evaluate the mentioned medication combined with hydroxyapatite. Eight patients with periapical osteolytic lesions that consent to participate in the study, aged between 18 and 60 years, were treated. The treatment was carry out in two groups; the first one using calcium hydroxide and the second one with a mixture of equal parts of calcium hydroxide and hydroxyapatite (Apafill-G), both products were mixed with sterile distilled water. The evaluated variables were: clinical appearance of soft tissues and permanency of the filler for periods of 7, 15 y 30 days 3,6,8,9 y 12 months, measure by X Rays radiographs. The final evaluation assessed bone repair and adverse reactions in the categories of Success and Failure. The results showed a radiographic permanency of the calcium hydroxide filler of 44 %, while the combined treatment (calcium hydroxide mixed with hydroxyapatite) remained in the root canal in 90 % of applications. The clinical appearance in the initial evaluation had one Bad case in group 2, which was evaluated as Well when repeating the instrumentation and filling, showing apical repair and absence of adverse reactions. Can be concluded that apical repair was achieved for both treatments and that the intracanal filler combined with hydroxyapatite achieved a significantly higher permanence of the filler, without adverse reactions.
Empleo de N-BUTIL-2-CIANOACRILATO TISUACRYL® en traumatismos bucofaciales con dentición primaria. Reporte de caso.
(2022) Mayra Pérez; José Rodríguez; Gladys Velazco; Daysi Márquez; María de los Ángeles Gutiérrez Pérez; Nicolasa Rudi; Luís Pérez y Pérez
El traumatismo buco-facial puede afectar los tejidos blandos, los órganos dentarios y el hueso del complejo maxilofacial. Presentamos un caso de traumatismo en la dentición temporal de un paciente de 4 años con lesión de los tejidos bucales y faciales. El tratamiento se realizó con 2 cianoacrilato de n-butilo (Tisuacryl®), para cierre de heridas y sellador hemostático. La aplicación fue de acuerdo con los protocolos de estos materiales y tipos de lesiones, así como el respeto a los principios éticos, según la Declaración de Helsinki. Las heridas y los dientes afectados se examinaron de forma convencional y se colocó Tisuacryl® como único método, sin necesidad de anestesia. La evaluación se clasificó en Éxito o Fracaso, 10 minutos inmediatamente después del sellado y 5 y 10 días después del tratamiento. Los resultados inmediatos reflejaron correcto sellado y alto poder hemostático, a los cinco y diez días mostraron excelente recuperación de los tejidos blandos, sin dehiscencia, ni reacciones adversas. En las radiografías iniciales se observó un ligero engrosamiento del espacio periodontal, que fue desapareciendo paulatinamente hasta hacerse inapreciable a los 10 días. En la evaluación final se observó una evolución clínica y radiográfica satisfactoria, por lo que fue catalogado como Éxito. También, extraordinario bienestar al tratamiento y evolución en todas las etapas, fue manifestado por la paciente y la mama. Podemos concluir que el tratamiento exitoso convierte al 2 cianoacrilato de n-butilo, (Tisuacryl®) en una alternativa eficaz al tratamiento de heridas traumáticas buco-faciales. No hubo reacciones adversas en el tratamiento aplicado.
Functionning of the Katari-Lago Menor Basin aquifer, Lake Titicaca-Bolivia, inferred from geophysical, hydrogeological and geochemical data
(2020) Céline Duwig; Gabriela Flores; Marc Descloîtres; Yvan Rossier; Lorenzo Spadini; Anatoly Legtchenko; Álvaro Soruco; Jaime Argollo; Mayra Pérez; Waldo Medinacelli
&lt;p&gt;The population of the semi-arid Bolivian Northern Altiplano depends greatly on groundwater resources, surface water being intermittent and often contaminated by human activities. The aim of this study is to provide a first insight into the hydrogeological structure and groundwater dynamics of the Katari-Lago Menor Basin aquifer located between the Eastern Cordillera and Lake Titicaca, Bolivia. Resistivity profiles combined with geology, borehole lithology, topography as well as additional groundwater level and geochemical measurements, were helpful in resolving the spatial limits of the aquifer, the vertical and lateral continuity of the Quaternary porous geologic media, the shape and position of the bottom of the aquifer (depth to the bedrock, i.e. Tertiary or Devonian Formations), and revealed a general overview of the natural dynamic behaviour of the aquifer at the scale of the Katari and Lago Menor Basin. The quaternary sediments are hydraulically connected and behave as a single regional basin-aquifer. The main groundwater flow system starts in the upper Piedmont (high mountain ranges of the Eastern Cordillera) and follows the topographic Piedmont gradient (NE to SW). Most groundwater recharge results from the infiltration of precipitation and runoff on the high mountain ranges. Indeed, groundwater circulating in the upper and lower Piedmont layers present primarily &amp;#160;facies. In the regions of the lower Piedmont urbanized areas, groundwater presenting &amp;#160;facies, show a noticeable enrichment of sulphate and chloride relating mainly anthropogenic contamination (mining and urban nature). A large portion of the aquifer presents an unconfined behaviour whereas it remains confined below the Ulloma Formation. The thickness of the unconfined portion varies from 50 to 150 meters and that of the confined from 100 to 150 meters. Values of hydraulic conductivity for the unconfined portion range from 1.1&amp;#215;10&lt;sup&gt;-4&lt;/sup&gt; m s&lt;sup&gt;-1&lt;/sup&gt; (alluvial fan deposit), 2.5&amp;#215;10&lt;sup&gt;-6 &lt;/sup&gt;m s&lt;sup&gt;-1&lt;/sup&gt; (fluvioglacial deposits,) to 5.9&amp;#215;10&lt;sup&gt;-8 &lt;/sup&gt;m s&lt;sup&gt;-1&lt;/sup&gt; (glacial deposits), while for the confined part transmissivity values range around 6.0&amp;#215;10&lt;sup&gt;-6&lt;/sup&gt;&amp;#160; m&lt;sup&gt;2&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt; (paleo-lacustrine deposits).&lt;/p&gt;&lt;p&gt;&amp;#160;This multidisciplinary approach proved to be an appropriate method to derive a consistent picture of the hydrogeological functioning of the Katari-Lago Menor Basin aquifer.&lt;/p&gt;
Insight into the Katari-Lago Menor Basin aquifer, Lake Titicaca-Bolivia, inferred from geophysical (TDEM), hydrogeological and geochemical data
(Elsevier BV, 2020) Gabriela Patricia Flores Avilés; Marc Descloîtres; Céline Duwig; Yvan Rossier; Lorenzo Spadini; A. Legchenko; Álvaro Soruco; Jaime Argollo; Mayra Pérez; Waldo Medinaceli
Relleno de defecto óseo postquirúrgico con hidroxiapatita: reporte de un caso
(2015) Jenair del Valle Yépez Guillén; Reynaldo Luis Ortíz Ramos; Mayra Pérez; Gladys Josefina Velazco Viloria; Anajulia González Betancourt; Dubraska Suárez Vega
Odontogenic cysts are characterized by a cavity lined by epithelium and a capsule containing connective tissue, being periapical cyst the most common one due to the chronic infection and necrosis of the pulp organ. These type of lesions causes irreversible damage to the bone tissue, which healing process is slow and not always leads to complete healing of the bone defect. Hydroxyapatite is the major component of bone and teeth of all vertebrates, that is why biomaterials based on hydroxyapatite does not cause significant immune response when implanted in the body. The aim of this paper is to demonstrate the effectiveness of hydroxyapatite (Apafill-G), as an osteoconductive and promoter of bone defects regeneration material. The case of a 32 years old male patient is reported, who at routine radiographic examination presented a jaw injury compatible with periapical cyst, associated with right upper central incisor, which was treated surgically, sealing the defect with Apafill-G (0,4mm-0,6mm), posterior suture with tissue adhesive (Tisuacryl®), and clinical and radiographic postoperative controls. Excellent results were obtained in the postoperative evaluation of the patient treated, proving the high biofunctionability and biocompatibility of the biomaterials used.
Respuesta biológica entre una hidroxiapatita y un betafosfato tricalcico en la regeneración de tejido óseo
(2011) Mayra Pérez; José Delgado; Gladys Josefina Velazco Viloria; Rosa Mayelín Guerra Bretaña; J A Juan Ortega
When teeth are extracted maxillary tissue and jaw bone is remodeled to form the residual alveolar ridge, which tends to be reabsorbed gradually taking different forms. This pheno-menon can be modified when placed in bone that contributes to the new formation and maintenance of bone morphology, thereby facilitating prosthetic treatment. The aim of this paper is to present a surgical technique combining internal and external filled the alveoli, allowing conventional prosthesis subsequently rehabilitate or metal implants. We present 5 patients who underwent dental extractions, the padding inside the socket with absorbable material (Biograft-G ®) and the outer table of the alveolar bone ridge regularized with the stable product Apafill-G ®. At that time placed a kind acrylic prosthesis immediately. Pa-tients were evaluated clinically and radiographically at 7 days, 1 month and 6 months. The results showed that both materials filled with proper bone regeneration achieved without peel granules, adjusting prosthesis and absence of sub denture stomatitis, edema or erythe-ma adverse events. We obtained a well-formed rim, avoiding the mandibular or maxillary atrophy. We achieved a strong external wall to receive acrylic prosthesis, while the inner filling resorbable facilitated the possibility of metallic implants. We conclude that this is a new surgical alternative to prevent the atrophy of the alveolar ridge without interfering infuture prosthetic rehabilitation.