Microbial surfactants: fundamentals and applicability in the formulation of nano-sized drug delivery vectors

Microbial surfactants, so-called biosurfactants, comprise a wide variety of structurally distinct amphipathic molecules produced by several microorganisms. Besides exhibiting surface activity at the interfaces, these molecules present powerful characteristics including high biodegradability, low toxicity and special biological activities (e.g. antimicrobial, antiviral, anticancer, among others), that make them an alternative to their chemical counterparts. Several medical-related applications have been suggested for these molecules, including some reports on their potential use in the formulation of nano-sized drug delivery vectors. However, despite their promises, due to the generalized lack of knowledge on microbial surfactants phase behavior and stability under diverse physicochemical conditions, these applications remain largely unexplored, thus representing an exciting field of research. These nano-sized vectors are a powerful approach towards the current medical challenges regarding the development of efficient and targeted treatments for several diseases. In this review, a special emphasis will be given to nanoparticles and microemulsions. Nanoparticles are very auspicious as their size, shape and stability can be manipulated by changing the environmental conditions. On the other hand, the easiness of formulation, as well as the broad possibilities of administration justifies the recent popularity of the microemulsions. Notwithstanding, both vector types still require further developments to overcome some critical limitations related with toxicity and costs, among others. Such developments may include the search for other system components, as the microbial surfactants, that can display improved features.The author acknowledges the financial support from the Strategic Project PEst-OE/EQB/LA0023/2013 and project ref. RECI/BBB-EBI/0179/2012 (project number FCOMP-01-0124-FEDER-027462) funded by Fundacao para a Ciencia e a Tecnologia

Cartografía estructural y mineral mediante imagen multiespectral en el Alto Atlas Central de Marruecos

The Central High Atlas is one of the geological structures that belong to the Moroccan Atlas massif. It presents a great geological diversity and many structural and facies features. It is controlled by main faults of N70 to E-W direction that are visible at different scales and is rich in numerous mineralized veins. This area was the subject of the present work, in which we simulated the images of Landsat 8 OLI, Sentinel 2, and Aster sensors to map the hydrothermal alteration minerals associated with a lithostructural mapping that can provide more information on the mineralization of this study area. We highlight different approaches to remote sensing, considering first the methods of extraction of lineaments from the infrared-band of the Landsat 8 OLI image and from the GDEM ASTER to highlight the geological features of the study area. To obtain a good discrimination of the lithological units, Principal Component Analysis and Optimal Index Factor were applied to create colored composites with a better visual interpretation in order to generate a good lithological mapping, and finally, many band ratios are proposed for ASTER, Landsat 8 OLI and Sentinel 2 to derive several maps corresponding to the hydrothermal alteration zones that are compared to the geological map of the studied site, presenting a favorable correlation between them. The analysis of the results of the obtained maps allowed us to identify the main structural directions encompassing the NE-SW to E-W, NNE-SWSW and ENE-WSW families and also allowed us to highlight two potential zones of mineralization; one located to the south of Demnate at the western end of the Central High Atlas and the other in the middle part of the Central High Atlas. The superposition of the alteration maps and the fracturing map shows that the zones that are favorable for mineralization deposits are affected by faults in a generally NE-SW direction.El Alto Atlas Central es una de las estructuras geológicas que pertenecen al Macizo del Atlas marroquí. Presenta una gran diversidad geológica y muchas características estructurales y de facies. Está controlada por fallas principales de dirección N70 a E-O, visibles a diferentes escalas y ricas en numerosas vetas mineralizadas. Esta zona ha sido objeto del presente trabajo, en el que hemos simulado las imágenes de los sensores Landsat 8 OLI, Sentinel 2 y Aster para cartografiar los minerales de alteración hidrotermal asociados a una cartografía litoestructural que puede aportar más información sobre la mineralización de esta zona de estudio. En este punto destacamos los diferentes enfoques de teledetección adoptados, citando en primer lugar los métodos de extracción de lineamientos a partir de la banda infrarroja de la imagen Landsat 8 OLI y del GDEM ASTER para destacar la fracción geológica del área de estudio. Para obtener una buena discriminación de las unidades litológicas se realizó un Análisis de Componentes Principales y se aplicó el Factor de Índice Óptimo para crear composiciones de color con mejor interpretación visual para tener una buena cartografía litológica, y finalmente, se proponen muchas relaciones de bandas para ASTER, Landsat 8 OLI y Sentinel 2 para derivar varios mapas correspondientes a las zonas de alteración hidrotermal que se comparan con el mapa geológico del lugar estudiado, que presenta una correlación favorable entre ellos. El análisis de los resultados de los mapas obtenidos permitió identificar las grandes direcciones estructurales materializadas por las familias NE-SW a E-W, NNE-SWSW y ENE-WSW y también permitió destacar dos zonas potenciales de mineralización: una situada al sur de Demnate en el extremo occidental del Alto Atlas Central y la otra en la parte central del Alto Atlas Central. La superposición de los mapas de alteración y del mapa de fracturación muestra que las zonas que pueden ser favorables para los depósitos de mineralización están afectadas por fallas en dirección generalmente NE-SW

Biomedical and therapeutic applications of biosurfactants

During the last years, several applications of biosurfactants with medical purposes have been reported. Biosurfactants are considered relevant molecules for applications in combating many diseases and as therapeutic agents due to their antibacterial, antifungal and antiviral activities. Furthermore, their role as anti-adhesive agents against several pathogens illustrate their utility as suitable anti-adhesive coating agents for medical insertional materials leading to a reduction of a large number of hospital infections without the use of synthetic drugs and chemicals. Biomedical and therapeutic perspectives of biosurfactants applications are presented and discussed in this chapter

Eumycotic mycetoma in a young girl from Sokoto, Nigeria: a rare and unusual presentation

Introduction: A typical presentation of Mycetoma is not uncommon although clinical manifestations might be misleading leading to delay in diagnosis, treatment and consequently leading to poor prognosis. Mycetoma can have a fungal or bacterial etiology and manifestation is usually that of a disfiguring subcutaneous infection that can affect any part of the exposed body. We are reporting a case of Mycetoma in an eleven years old girl that occurred in parts of the lower abdomen, perineum and gluteal region that was initially thought to be a soft tissue sarcoma or disseminated tuberculosis.Case Presentation: An eleven years old girl presented to Usmanu Danfodiyo University Teaching Hospital, Sokoto with lower abdominal mass and multiple nodular masses with discharging sinuses on the upper part of the right thigh, perineum and gluteal region of six months duration. Swellings started as multiple small boils that subsequently started discharging from various points. Patient usually fetches firewood in the forest for her parents as her routine house chores and she remembered an incident where she had pricks from thorns in the bush around her lower thigh and perineum. On examination she was chronically ill looking, in painful distress, with bilateral inguinal lymphadenopathy. She had nodular lesions of varying sizes ranging from 1x1cm to 4x4cm, tender, involving the upper part of the thigh bilaterally, but more on the right, lower abdomen, labia and gluteal region. Some of the lesions had hyper-pigmented sinuses discharging mucopurulent fluid, with areas of soft tissue swelling around the lower abdomen and upper right thigh extending to the leg. Patient was observed to walk with a limp gait.Management and Outcome: An initial diagnosis of soft tissue infection to rule out soft tissue sarcoma and disseminated tuberculosis (abdomen and lymph nodes) and deep tissue mycosis was made. However, with further investigations and reviews by the medical microbiologist and anatomic pathologist, along with bacteriologic, and mycologic studies of swab samples and aspirate and tissue biopsy for Histology revealed an eumycotic mycetoma. She received Ketoconazole and Trimetoprim-sulphametoxazole. She responded significantly as lesions reduced in sizes, abdominal swelling and leg swelling reduced with closure of discharging sinuses. Patient could walk with some resolution of the limp. Repeat abdominal ultrasound scan showed resolution of initial findings. She spent four weeks in the hospital and was discharged. On subsequent follow-up; she was walking without any limp and lesions were healed with some scar and few areas left to dry up. Further follow-up visits after one month and three month showed progressive healing and complete resolution of lesion respectively. However. Patient was however lost to further follow-up which would have enabled monitoring as to any reoccurrence or not.Conclusion: We presented a case of a young girl with an abnormal presentation of eumycotic mycetoma. Patient achieved near cure on medications without the need of surgery due to an excellent multidisciplinary approach between pediatricians, clinicians, clinical microbiologists and anatomic pathologists.Keywords: Mycetoma, Eumycetoma, Paediatric

Biomechanical simulations of the scoliotic deformation process in the pinealectomized chicken: a preliminary study

<p>Abstract</p> <p>Background</p> <p>The basic mechanisms whereby mechanical factors modulate the metabolism of the growing spine remain poorly understood, especially the role of growth adaptation in spinal disorders like in adolescent idiopathic scoliosis (AIS). This paper presents a finite element model (FEM) that was developed to simulate early stages of scoliotic deformities progression using a pinealectomized chicken as animal model.</p> <p>Methods</p> <p>The FEM includes basic growth and growth modulation created by the muscle force imbalance. The experimental data were used to adapt a FEM previously developed to simulate the scoliosis deformation process in human. The simulations of the spine deformation process are compared with the results of an experimental study including a group of pinealectomized chickens.</p> <p>Results</p> <p>The comparison of the simulation results of the spine deformation process (Cobb angle of 37°) is in agreement with experimental scoliotic deformities of two representative cases (Cobb angle of 41° and 30°). For the vertebral wedging, a good agreement is also observed between the calculated (28°) and the observed (25° – 30°) values.</p> <p>Conclusion</p> <p>The proposed biomechanical model presents a novel approach to realistically simulate the scoliotic deformation process in pinealectomized chickens and investigate different parameters influencing the progression of scoliosis.</p

Lubiprostone Decreases the Small Bowel Transit Time by Capsule Endoscopy: An Exploratory, Randomised, Double-Blind, Placebo-Controlled 3-Way Crossover Study

The aim of this study was to investigate the usefulness of lubiprostone for bowel preparation and as a propulsive agent in small bowel endoscopy. Six healthy male volunteers participated in this randomized, 3-way crossover study. The subjects received a 24 μg tablet of lubiprostone 60 minutes prior to the capsule ingestion for capsule endoscopy (CE) and a placebo tablet 30 minutes before the capsule ingestion (L-P regimen), a placebo tablet 60 minutes prior to CE and a 24 μg tablet of lubiprostone 30 minutes prior to CE (P-L regimen), or a placebo tablet 60 minutes prior to r CE and a placebo tablet again 30 minutes prior to CE (P-P regimen). The quality of the capsule endoscopic images and the amount of water in the small bowel were assessed on 5-point scale. The median SBTT was 178.5 (117–407) minutes in the P-P regimen, 122.5 (27–282) minutes in the L-P regimen, and 110.5 (11–331) minutes in the P-L regimen (P=0.042). This study showed that the use of lubiprostone significantly decreased the SBTT. We also confirmed that lubiprostone was effective for inducing water secretion into the small bowel during CE

Brazilian green propolis modulates inflammation, angiogenesis and fibrogenesis in intraperitoneal implant in mice

BACKGROUND: Chronic inflammatory processes in the peritoneal cavity develop as a result of ischemia, foreign body reaction, and trauma. Brazilian green propolis, a beeswax product, has been shown to exhibit multiple actions on inflammation and tissue repair. Our aim was to investigate the effects of this natural product on the inflammatory, angiogenic, and fibrogenic components of the peritoneal fibroproliferative tissue induced by a synthetic matrix. METHODS: Chronic inflammation was induced by placing polyether-polyurethane sponge discs in the abdominal cavity of anesthetized Swiss mice. Oral administration of propolis (500/mg/kg/day) by gavage started 24 hours after injury for four days. The effect of propolis on peritoneal permeability was evaluated through fluorescein diffusion rate 4 days post implantation. The effects of propolis on the inflammatory (myeloperoxidase and n-acetyl-β-D-glucosaminidase activities and TNF-α levels), angiogenic (hemoglobin content-Hb), and fibrogenic (TGF-β1 and collagen deposition) components of the fibrovascular tissue in the implants were determined 5 days after the injury. RESULTS: Propolis was able to decrease intraperitoneal permeability. The time taken for fluorescence to peak in the systemic circulation was 20 ± 1 min in the treated group in contrast with 15 ± 1 min in the control group. In addition, the treatment was shown to down-regulate angiogenesis (Hb content) and fibrosis by decreasing TGF-β1 levels and collagen deposition in fibroproliferative tissue induced by the synthetic implants. Conversely, the treatment up-regulated inflammatory enzyme activities, TNF-α levels and gene expression of NOS2 and IFN-γ (23 and 7 fold, respectively), and of FIZZ1 and YM1 (8 and 2 fold) when compared with the untreated group. CONCLUSIONS: These observations show for the first time the effects of propolis modulating intraperitoneal inflammatory angiogenesis in mice and disclose important action mechanisms of the compound (downregulation of angiogenic components and activation of murine macrophage pathways)