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Our skin is home to a diverse community of commensal microorganisms integral to cutaneous function. However, microbial dysbiosis and barrier perturbation increase the risk of local and systemic infection. Staphylococcus aureus is a particularly problematic bacterial pathogen, with high levels of antimicrobial resistance and direct association with poor healing outcome. Innovative approaches are needed to selectively kill skin pathogens, such as S aureus, without harming the resident microbiota. In this study, we provide important data on the selectivity and efficacy of an S aureus-targeted endolysin (XZ.700) within the complex living skin/wound microbiome. Initial cross-species comparison using Nanopore long-read sequencing identified the translational potential of porcine rather than murine skin for human-relevant microbiome studies. We therefore performed an interventional study in pigs to assess the impact of endolysin administration on the microbiome. XZ.700 selectively inhibited endogenous porcine S aureus in vivo, restoring microbial diversity and promoting multiple aspects of wound repair. Subsequent mechanistic studies confirmed the importance of this microbiome modulation for effective healing in human skin. Taken together, these findings strongly support further development of S aureus-targeted endolysins for future clinical management of skin and wound infections.
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Microbiota , Piel , Staphylococcus aureus , Cicatrización de Heridas , Animales , Staphylococcus aureus/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacos , Piel/microbiología , Microbiota/efectos de los fármacos , Porcinos , Humanos , Ratones , Endopeptidasas , Modelos Animales de Enfermedad , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/tratamiento farmacológico , FemeninoRESUMEN
OBJECTIVE: One recommended psychological intervention for trauma treatment in Western countries, including posttraumatic stress disorder (PTSD), is eye movement desensitization reprocessing (EMDR). However, there is a paucity of data regarding treatment interventions in low- and middle-income countries. This study examined the efficacy of EMDR for treating posttraumatic stress (PTS), anxiety, and depression among a cohort of individuals with low socioeconomic status in a conflict-affected middle-income country as well as a smaller refugee cohort. METHODS: Two hundred and sixty-eight adults residing in Lebanon (male = 65, female = 203, SDgender = 0.43; µage = 30.5, SDage = 10.49; 85% Lebanese, 15% refugees [9.3% from Syria, and 5.7% from Iraq, Palestine, the Philippines, and Other]) received EMDR therapy. Measures of PTS, anxiety, and depression were taken at three time points: before treatment (T0), posttreatment (T1), and 6-month follow-up (T2). RESULTS: Reduction in PTS symptoms from T0 to T1, F(1, 208) = 412.3, p < .01, and T1 to T2, F(1, 46) = 136.1, p < .01. Reduction in anxiety symptoms from T0 to T1, F(1, 208) = 387.0, p < .01, and T1 to T2, F(1, 46) = 153.7, p < .01. Similarly, for depression, a reduction of symptoms from T0 to T1, F(1, 207) = 309.5, p < .01, and T0 to T2, F(1, 46) = 96.0, p < .01. CONCLUSION: This research supports the use of EMDR for the treatment of PTS, depression, and anxiety symptoms in individuals with low socioeconomic status and refugees, thus contributing to the research base for populations that are under-researched. Mental health services, especially in conflict-affected settings, would benefit from using EMDR therapy to target these pathologies in these populations. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
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BACKGROUND: British American Football (BAF) is a developing sport in the UK, with keen growth in the British Universities and Colleges Sport (BUCS) league. Participation in BAF carries risks and so to facilitate safe participation medical care services must be evaluated. AIMS: To evaluate medical provision in BUCS American Football in the 2019-2020 season. METHODS: An online survey tool was used to collect data from BUCS BAF teams in the 2019-2020 season. Thirty-one teams (from across England, Wales and Scotland) responded to questions on facilities, provision and procedures. RESULTS: Almost 42% of teams had a regular team first aider who attended home games each week. Only 61.5% attended away games and 7.7% attended team training. Access to a first aider was not dependent upon division. Home games were more likely to be risk assessed and have an emergency action plan compared to away games. The majority of teams had access to automated external defibrillator (AED) within 100 m of the pitch, yet only 29% of staff were trained to use them. Almost 84% of teams reported carrying a designated fully charged phone (with signal). Prominent qualitative themes indicated were cost/funding as barriers to hiring qualified medical staff, lack of institutional support, unreliability of medical provision and inadequate facilities/preparation for games. CONCLUSIONS: These findings provide key information on the status of medical provision, facilities and protocols in BUCS BAF. Data reveals a lack of consistent medical personnel, particularly at training and away games, and training in emergency care.
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Servicios Médicos de Urgencia , Fútbol Americano , Humanos , Universidades , Personal de Salud , InglaterraRESUMEN
OBJECTIVES: To examine concussion knowledge and concussion attitudes of players, coaches, and support staff in British American Football (BAF). METHODS: Data from players, coaches and support staff (n = 236) were collected from across all leagues in BAF. An online survey tool was used which included the Rosenbaum Concussion Knowledge and Attitudes Survey (RoCKAS), and questions examining concussion education and perceived risk of participating in football. RESULTS: The mean score on the RoCKAS concussion knowledge was 21.0 ± 2.1 of a possible score of 25 reflecting good knowledge. Of a possible score of 65, the mean concussion attitude score was 55.6 ± 6.1 showing safe attitude. Whilst an overall safe attitude was seen, almost half of participants (45.3%) noted they would continue to play with a concussion. No relationship was found between CAI and prior concussion history. Fifty seven percent of participants agreed the benefits of playing football outweighed the risks. Forty eight percent reported that they had received no concussion-related education in the past 12 months. CONCLUSION: BAF participants have good concussion knowledge and safe attitudes. However, risky behavior is demonstrated through unsafe likelihood to report and attitude to long-term health risks. Access to the British American Football Association (BAFA) concussion policy and education was poor raising questions over what sources of information stakeholders are drawing their knowledge from. These findings can help form the foundation of educational interventions (e.g. coaching workshops) to challenge current misconceptions and improve likelihood to report concussion in BAF.
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BACKGROUND: Vitamin D deficiency has been postulated as a cause for impaired bone healing and remodeling. The purpose of this study was to assess the potential association between low vitamin D levels and reoperation for nonunion following ankle fusion surgery. METHODS: All adult patients (aged ≥18 years) who underwent ankle fusion procedures at a tertiary referral center from January 2010 to January 2019 with available vitamin D levels within 12 months preoperatively were retrospectively reviewed (n = 47). Patients were categorized as vitamin D deficient (<30 ng/mL) vs normal (31-80 ng/mL). The primary outcome was the incidence of reoperation secondary to nonunion. Secondary outcomes included incidence of reoperation not related to nonunion and the need for repeat reoperation. RESULTS: The average level in the vitamin D-deficient group (n = 17; 36.2%) was 16.9 vs 46.4 ng/mL in the normal group (n = 30; 63.8%). All recorded reoperations for nonunion occurred exclusively in the vitamin D-deficient cohort (4/17 [23.5%]; P = .013). There were similar reoperation rates for causes other than nonunion (2/17 [11.8%] vs 4/30 [13.3%]; P > .99) and repeat reoperation rates (3/17 [17.6%] vs 1/30 [3.3%]; P = .128) among vitamin D-deficient vs normal patients. CONCLUSION: Vitamin D deficiency may be associated with an increased risk of reoperation for nonunion after ankle fusion.
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Tobillo , Deficiencia de Vitamina D , Adolescente , Adulto , Tobillo/cirugía , Articulación del Tobillo/cirugía , Artrodesis/métodos , Humanos , Reoperación , Estudios Retrospectivos , Resultado del Tratamiento , Vitamina D , Deficiencia de Vitamina D/complicacionesRESUMEN
To relieve the severe economic and social burdens and patient suffering caused by the increasing incidence of chronic wounds, more effective treatments are urgently needed. In this study, we focused on developing a novel sprayable wound dressing with the active ingredient ß-1,3/1,6-glucan (ßG). Since ßG is already available as the active ingredient in a commercial wound healing product provided as a hydrogel in a tube (ßG-Gel), the sprayable format should bring clinical benefit by being easily sprayed onto wounds; whilst retaining ßG-Gel's physical stability, biological safety and wound healing efficacy. Potentially sprayable ßG hydrogels were therefore formulated, based on an experimental design setup. One spray formulation, named ßG-Spray, was selected for further investigation, as it showed favorable rheological and spraying properties. The ßG-Spray was furthermore found to be stable at room temperature for more than a year, retaining its rheological properties and sprayability. The cytotoxicity of ßG-Spray in keratinocytes in vitro, was shown to be promising even at the highest tested concentration of 100 µg/ml. The ßG-Spray also displayed favorable fluid affinity characteristics, with a capacity to both donate and absorb close to 10% fluid relative to its own weight. Finally, the ßG-Spray was proven comparably effective to the commercial product, ßG-Gel, and superior to both the water and the carrier controls (NoßG-Spray), in terms of its ability to promote wound healing in healing-impaired animals. Contraction was found to be the main wound closure mechanism responsible for the improvement seen in the ßG-treatment groups (ßG-Spray and ßG-Gel). In conclusion, the novel sprayable ßG formulation, confirmed its potential to expand the clinical use of ßG as wound dressing.
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Complicaciones de la Diabetes/terapia , Apósitos Oclusivos , Cicatrización de Heridas , Heridas y Lesiones , beta-Glucanos/farmacología , Adyuvantes Inmunológicos , Animales , Composición de Medicamentos/métodos , Estabilidad de Medicamentos , Humanos , Hidrogeles/farmacología , Ratones , Ratones Endogámicos , Resultado del Tratamiento , Cicatrización de Heridas/efectos de los fármacos , Cicatrización de Heridas/fisiología , Heridas y Lesiones/etiología , Heridas y Lesiones/terapiaRESUMEN
The objective of this study was to examine concussion reporting and safeguarding policy in British American Football (BAF). Data were collected via an online survey tool. The data presented are part of a broader study that examined injury profiles, concussion reporting behaviors, and medical provision in BAF. Concussion-like symptoms were found in over half (58.8%) of the participants. Of those, 36.4% reported they had previously been formally diagnosed with a concussion while playing BAF. Just under half of the participants (44.7%) had suspected they had had a concussion, although it was not formally diagnosed, and 23.5% of the participants had previously hidden concussion symptoms. Fifty-eight percent of the teams reported they did not have a regular game-day medic, with a range of hired medical personnel who attended the games. Prominent barriers to hiring a medic included budget, institutional support shortfall, and lack of medic reliability and game knowledge. BAF is a developing sport with a clear vision for growth of participation. Yet, the current concussion and medical provision policies do not address the sport's welfare needs. Through discussion of these policies in the context of this study's findings, we highlight vital areas of concern in policy and practice that the British American Football Association needs to address in their medical and concussion policies.
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Objective: Traditional negative pressure wound therapy (tNPWT) systems can be large and cumbersome, limiting patient mobility and adversely affecting quality of life. PICO™, a no canister single-use system, offers a lightweight, portable alternative to tNPWT, with improved clinical performance. The aim of this study was to determine the potential mechanism(s) of action of single-use NPWT (sNPWT) versus tNPWT. Approach: sNPWT and tNPWT were applied to an in vivo porcine excisional wound model, following product use guidelines. Macroscopic, histological, and biochemical analyses were performed at defined healing time points to assess multiple aspects of the healing response. Results: Wounds treated with single-use negative pressure displayed greater wound closure and increased reepithelialization versus those treated with traditional negative pressure. The resulting granulation tissue was more advanced with fewer neutrophils, reduced inflammatory markers, more mature collagen, and no wound filler-associated foreign body reactions. Of note, single-use negative pressure therapy failed to induce wound edge epithelial hyperproliferation, while traditional negative pressure therapy compromised periwound skin, which remained inflamed with high transepidermal water loss; features not observed following single-use treatment. Innovation: Single-use negative pressure was identified to improve multiple aspects of healing versus traditional negative pressure treatment. Conclusion: This study provides important new insight into the differing mode of action of single-use versus traditional negative pressure and may go some way to explaining the improved clinical outcomes observed with single-use negative pressure therapy.
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Terapia de Presión Negativa para Heridas , Cicatrización de Heridas/fisiología , Animales , Quemaduras/terapia , Humanos , Calidad de Vida , Porcinos , Resultado del TratamientoRESUMEN
Correction for 'A diet containing high- versus low-daidzein does not affect bone density and osteogenic gene expression in the obese Zucker rat model' by Eric Rochester et al., Food Funct., 2019, 10, 6851-6857.
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Phytoestrogens are nonsteroidal plant compounds with similar chemical structures to mammalian estrogen capable of mimicking the effect of estrogen in selective tissues. A diet rich in phytoestrogens is associated with a variety of health benefits including decreased risks for heart disease, breast cancer, and osteoporosis. Obesity has long thought to be associated with improved bone density due to increased mechanical loading, but recent literature suggests obesity may actually decrease bone health. Daidzein, a soy-derived phytoestrogen, has been shown to improve parameters of bone health in lean animal models of osteoporosis but has not been tested in obese animals. Following a one-week acclimation to a standard AIN-93G diet, 19 five-week-old female obese Zucker rats (OZR) were randomly assigned to a modified AIN-93G diet containing either high daidzein (HD, 0.121 g kg-1 feed) or low daidzein (LD, 0.01 g kg-1 feed). After 8 weeks, tibias and femurs were removed to assess true density (Archimedes principal), mechanical strength (three-point bending test), and femoral osteogenic gene expression. Serum was collected to assess osteocalcin and deoxypyridinoline. Our results indicated that there were no significant differences between the measures for tibial or femoral true density or mechanical strength for the rats in the HD and LD diet groups. Similarly, there were no significant differences in gene expressions related to osteogenic pathways, or serum biomarkers of bone formation and resorption. Overall, an increased dose of daidzein from soy protein supplementation does not elicit an improvement in markers of bone health in obese Zucker rats.
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Densidad Ósea/efectos de los fármacos , Dieta , Expresión Génica/efectos de los fármacos , Isoflavonas/farmacología , Obesidad/tratamiento farmacológico , Osteogénesis/efectos de los fármacos , Aminoácidos/sangre , Animales , Biomarcadores , Peso Corporal/efectos de los fármacos , Densidad Ósea/genética , Huesos/efectos de los fármacos , Suplementos Dietéticos , Modelos Animales de Enfermedad , Ingestión de Energía , Femenino , Fémur , Obesidad/dietoterapia , Osteocalcina/sangre , Osteogénesis/genética , Osteoporosis/dietoterapia , Osteoporosis/tratamiento farmacológico , Fitoestrógenos/farmacología , Ratas , Ratas ZuckerRESUMEN
Non-alcoholic fatty liver disease is a common liver disorder worldwide and is associated with obesity. We investigated effects of obesity and short-term intake of soy protein with isoflavones (SPI) on body weight change, energy intake, liver steatosis, and serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and leptin levels. Seventeen lean and seventeen obese (fa/fa) female Zucker rats were randomly assigned to either casein or SPI diet for 8 weeks. Body weight was recorded twice weekly; feed intake was measured weekly. Livers were examined histologically, and serum AST, ALT, and leptin levels were measured. Obese soy-fed (OS) rats gained more weight but had lower liver steatosis than obese casein-fed (OC) rats. Energy intake for OS versus OC rats were only different at weeks 2 and 3. Serum AST and ALT levels were lower in OS versus OC rats. Obesity increased serum leptin levels for both diets. In summary, short-term SPI intake reduced liver steatosis, and the only time points at which the mean energy intakes of OS and OC rats differed were at weeks 2 and 3, where OS rats had a higher mean energy intake, which may have accounted for the increased body weight in OS rats.
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OBJECTIVES: To compare the current methods of appointment, qualifications and occupational experience of club doctors and physiotherapists in English professional football with (i) those outlined in a study published in 1999, and (ii) Football Association (FA) medical regulations. DESIGN: Qualitative. METHODS: Postal questionnaire survey of (head) doctors and physiotherapists at each of the clubs in the English Premiership, Championship and Football Leagues 1 and 2. Response rates of 35.8% and 45.6% respectively were obtained. RESULTS: The majority of football club doctors are GPs who have sports medicine qualifications and relevant occupational experience. Time commitments vary from full time to a few hours per week. Most are appointed through personal contacts rather than job advertisements and/or interview. Almost all football clubs have a chartered physiotherapist, many of whom have a postgraduate qualification. They work full time and long hours. Most are appointed through personal contacts rather than job advertisements. They are frequently interviewed but not always by someone qualified to judge their professional expertise. CONCLUSIONS: Football club medical provision has become more extensive and increasingly professional over the last 10-20years, with better qualified, more career-oriented and more formally contracted staff. It is likely that clinical autonomy has subsequently increased. However recruitment procedures still need to be improved, especially in relation to advertising vacancies, interviewing candidates, and including medical personnel on interview panels. In two aspects clubs appear not to be compliant with current FA medical regulations.
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Fisioterapeutas/normas , Médicos/normas , Fútbol , Medicina Deportiva , Adulto , Competencia Clínica , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Reino Unido , Recursos HumanosRESUMEN
The prevalence of obesity is increasing worldwide. Obesity increases the risk for non-alcoholic fatty liver disease through adipokine dysregulation and inflammation. Previously, we have reported that a high-isoflavone soy protein isolate (HISPI) diet is associated with significantly heavier body weights and reduced liver steatosis in obese Zucker rats (OZR) compared to a casein diet. The objective of this study was to investigate whether daidzein, a soy isoflavone in HISPI, is responsible for increased body weight gain or reduced liver steatosis. We hypothesized that a casein diet containing high daidzein (HD) compared to low daidzein (LD) would mitigate hepatic steatosis in female OZR. We used 19 five-week-old female OZR (fa/fa). Rats were randomly assigned to a modified AIN-93G diet containing HD (0.121 g kg-1 feed) or LD (0.01 g kg-1 feed). Rats were weighed twice weekly. Feed intake was measured once weekly, and kcal per kg of body weight was calculated. After 8 weeks, rats were sacrificed. Serum and livers were collected. Sections of the liver lobe were fixed in 10% buffered formalin and stained with hematoxylin and eosin. Steatosis was semiquantitated as a score of 1 to 4 based upon the relative degree of steatosis within hepatocytes: (1) <25%, (2) 25%-50%, (3) 50%-75%, and (4) >75%. Serum leptin and adiponectin were measured by ELISA. Our results did not show significant differences in mean liver steatosis scores, body weights, energy intake, and serum leptin and adiponectin levels between diet groups. In conclusion, daidzein may not be the main component of HISPI responsible for increasing body weight or reducing liver steatosis in OZR.
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Glycine max/metabolismo , Isoflavonas/metabolismo , Enfermedad del Hígado Graso no Alcohólico/dietoterapia , Extractos Vegetales/metabolismo , Adiponectina/sangre , Animales , Femenino , Humanos , Insulina/sangre , Isoflavonas/administración & dosificación , Leptina/sangre , Metabolismo de los Lípidos , Hígado/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Extractos Vegetales/administración & dosificación , Ratas , Ratas Zucker , Glycine max/químicaRESUMEN
Obesity is a major health problem in the US and globally. Obesity is associated with the risk of cardiovascular disease, type 2 diabetes, cancers, hyperlipidemia, and liver steatosis development. Dehydroepiandrosterone (DHEA) is a dietary supplement used as an anti-obesity supplement. Previously, we reported that DHEA feeding protects 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary tumors. The objectives of this study were to investigate the effects of obesity and DHEA feeding on liver steatosis, body weight gain, and serum DHEA, DHEA sulfate (DHEA-S), insulin-like growth factor-1 (IGF-1), and insulin-like growth factor binding protein-3 (IGFBP-3) levels. Female Zucker rats were randomly assigned to either a control diet or a control diet with DHEA supplementation for 155 days. Livers were collected for histological examination. Serum was collected to measure DHEA, DHEA-S, IGF-1, and IGFBP-3. Our results show that DHEA-fed rats had significantly less liver steatosis (p < 0.001) than control-fed rats and gained less weight (p < 0.001). DHEA feeding caused significant decreases (p < 0.001) in the serum levels of IGF-1 and IGFBP-3 and significantly increased (p < 0.001) serum levels of DHEA and DHEA-S. Our results suggest that DHEA feeding can protect against liver steatosis by reducing body weight gain and modulating serum IGF-1 and IGFBP-3 levels in an obese breast cancer rat model.
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A sound knowledge of anatomical variations that could be encountered during surgical procedures is helpful in avoiding surgical complications. The current article details anomalous morphology of inferior alveolar nerves encountered during routine dissection of the craniofacial region in the Gross Anatomy laboratory. We also report variations of the lingual nerves, associated with the inferior alveolar nerves. The variations were documented and a thorough review of literature was carried out. We focus on the variations themselves, and the clinical implications that these variations present. Thorough understanding of variant anatomy of the lingual and inferior alveolar nerves may determine the success of procedural anesthesia, the etiology of pathologic processes, and the avoidance of surgical misadventure.
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Variación Anatómica , Anestesia Dental/métodos , Anestesia Local/métodos , Nervio Mandibular/anatomía & histología , Anciano de 80 o más Años , Cadáver , Arco Dental/inervación , Femenino , Humanos , Nervio Lingual/anatomía & histología , Masculino , Mandíbula/inervación , Arteria Maxilar/inervaciónRESUMEN
Potentiometric membrane electrodes that respond to heparin and other polyanions were introduced in the early 1990s. Herein, the mechanism of polymer membrane electrode type heparin sensors is revisited. The extraction/diffusion of heparin is studied via both potentiometric and impedance spectroscopic techniques using a pre-fractionated heparin preparation that contains polyanionic species > 10000 Daltons. The reversal in EMF response using this heparin preparation indicates diffusion of higher MW heparin fragments to the backside of the membrane. Diffusion coefficients are calculated using a novel formula derived from the phase boundary potential model and Fick's second law of diffusion. Impedance spectroscopy is also employed to show that high MW heparin species are extracted and diffuse across the PVC membranes.
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Chronic wounds, such as ulceration of the lower limb, represent a significant clinical challenge in today's ageing society. With the aim of identifying improved therapeutics, we have previously described a bioresponsive, dextrin-recombinant human epidermal growth factor conjugate (dextrin-rhEGF), that (i) protects rhEGF against proteolytic degradation by human chronic wound fluid; and (ii) mediates rhEGF release by α-amylase, capable of stimulating increased proliferation/migration in normal dermal and chronic wound fibroblasts; and keratinocytes, in vitro. The aim of this study was to extend these findings, by investigating the effects of dextrin-rhEGF on wound healing in the (db/db) diabetic mouse, a widely used in vivo model of delayed wound healing. Standardised, full-thickness excisional wounds, created in the dorsal flank skin, were treated topically with succinoylated dextrin (50 µg/mL), rhEGF (10 µg/mL) or dextrin-rhEGF (1 or 10 µg/mL). Treatments were applied immediately after injury and subsequently on post-wounding, days 3 and 8. Wound healing was assessed macroscopically, in terms of initiation of neo-dermal tissue deposition and wound closure (including wound contraction and re-epithelialisation), over a 16 day period. Wound healing was assessed histologically, in terms of granulation tissue formation/maturity; cranio-caudal wound contraction and wound angiogenesis (CD31 immuno-staining), using tissues harvested at day 16. Blood samples were also analysed for α-amylase and rhEGF concentrations. In this established impaired wound healing model, the topically-applied dextrin-rhEGF significantly accelerated wound closure and neo-dermal tissue formation at the macroscopic level; and significantly increased granulation tissue deposition and angiogenesis at the histological level (p<0.05), relative to untreated, succinoylated dextrin and rhEGF alone controls. Overall, these findings support the further development of bioresponsive polymer conjugates, for tissue repair.
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Dextrinas/química , Complicaciones de la Diabetes/tratamiento farmacológico , Portadores de Fármacos/química , Factor de Crecimiento Epidérmico/administración & dosificación , Factor de Crecimiento Epidérmico/uso terapéutico , Proteínas Recombinantes/administración & dosificación , Cicatrización de Heridas/efectos de los fármacos , Animales , Complicaciones de la Diabetes/patología , Factor de Crecimiento Epidérmico/sangre , Factor de Crecimiento Epidérmico/química , Factor de Crecimiento Epidérmico/farmacología , Tejido de Granulación/anatomía & histología , Tejido de Granulación/irrigación sanguínea , Tejido de Granulación/efectos de los fármacos , Tejido de Granulación/crecimiento & desarrollo , Humanos , Masculino , Ratones , Ratones Mutantes , Neovascularización Fisiológica/efectos de los fármacos , Proteínas Recombinantes/sangre , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacología , Proteínas Recombinantes/uso terapéutico , Piel/efectos de los fármacos , Piel/patología , alfa-Amilasas/sangreRESUMEN
The large molecular size of antibody drugs is considered one major factor preventing them from becoming more efficient therapeutics. Variable regions of heavy chain antibodies (HCAbs), or single-domain antibodies (sdAbs), are ideal building blocks for smaller antibodies due to their molecular size and enhanced stability. In the search for better antibody formats for in vivo imaging and/or therapy of cancer, three types of sdAb-based molecules directed against epidermal growth factor receptor (EGFR) were constructed, characterized and tested. Eleven sdAbs were isolated from a phage display library constructed from the sdAb repertoire of a llama immunized with a variant of EGFR. A pentameric sdAb, or pentabody, V2C-EG2 was constructed by fusing one of the sdAbs, EG2, to a pentamerization protein domain. A chimeric HCAb (cHCAb), EG2-hFc, was constructed by fusing EG2 to the fragment crystallizable (Fc) of human IgG1. Whereas EG2 and V2C-EG2 localized mainly in the kidneys after i.v. injection, EG2-hFc exhibited excellent tumor accumulation, and this was largely attributed to its long serum half life, which is comparable to that of IgGs. The moderate size (approximately 80 kDa) and intact human Fc make HCAbs a unique antibody format which may outperform whole IgGs as imaging and therapeutic reagents.
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Sistemas de Liberación de Medicamentos , Receptores ErbB/efectos de los fármacos , Fragmentos de Inmunoglobulinas/farmacología , Secuencia de Aminoácidos , Animales , Camélidos del Nuevo Mundo , Línea Celular Tumoral , Receptores ErbB/genética , Femenino , Humanos , Fragmentos de Inmunoglobulinas/administración & dosificación , Fragmentos de Inmunoglobulinas/genética , Masculino , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Neoplasias Pancreáticas/tratamiento farmacológico , Ingeniería de Proteínas , Alineación de SecuenciaRESUMEN
The solvation parameter model is now well established as a useful tool for obtaining quantitative structure-property relationships for chemical, biomedical and environmental processes. The model correlates a free-energy related property of a system to six free-energy derived descriptors describing molecular properties. These molecular descriptors are defined as L (gas-liquid partition coefficient on hexadecane at 298K), V (McGowan's characteristic volume), E (excess molar refraction), S (dipolarity/polarizability), A (hydrogen-bond acidity), and B (hydrogen-bond basicity). McGowan's characteristic volume is trivially calculated from structure and the excess molar refraction can be calculated for liquids from their refractive index and easily estimated for solids. The remaining four descriptors are derived by experiment using (largely) two-phase partitioning, chromatography, and solubility measurements. In this article, the use of gas chromatography, reversed-phase liquid chromatography, micellar electrokinetic chromatography, and two-phase partitioning for determining solute descriptors is described. A large database of experimental retention factors and partition coefficients is constructed after first applying selection tools to remove unreliable experimental values and an optimized collection of varied compounds with descriptor values suitable for calibrating chromatographic systems is presented. These optimized descriptors are demonstrated to be robust and more suitable than other groups of descriptors characterizing the separation properties of chromatographic systems.
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Cromatografía de Gases/métodos , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Capilar Electrocinética Micelar/métodos , Enlace de Hidrógeno , Concentración de Iones de Hidrógeno , SolubilidadRESUMEN
Monoclonal antibodies have been successfully engineered as approved therapeutics. However, their large size is considered a major factor preventing them from having a more efficient tissue penetration. As the first step to establish a possibly more efficient antibody platform, we present here transient expression, purification and characterization of six chimeric heavy chain antibodies (cHCAbs), or fusion of camelid single domain antibodies (sdAbs) to human fragment crystallizable (Fc). All six HCAbs have a MW of approximately 80 kDa, expressed well in a HEK293 expression system and have G0, G1 and G2 types of glycosylation. The transient expression also provided a very fast way to generate high milligram to low gram amount of proteins for in vitro assays and preliminary animal studies.