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BACKGROUND: Because of critical shortage of physician anaesthesiologists, the government of Tanzania adopted a task shifting strategy for provision of anaesthesia services. This paper describes the results of an operational study designed to increase the number of anaesthesia providers for emergency obstetric surgeries in order to reduce maternal and perinatal mortality in underserved rural Tanzania. METHODS: In 2016 a before-after cohort study was conducted in seven health centres in rural Tanzania. Five health centres received an intervention and two were selected to track secular trends (control group). Ten associate clinicians, i.e. assistant medical officers, clinical officers, and nurse midwives, from five health centres were trained in anaesthesia skills for emergency obstetric surgeries for three months followed by quarterly supportive supervision, mentoring and teleconsultation to reinforce skills. Primary and secondary outcome measures included Caesarean delivery (CD) rate, quality and safety of anaesthesia, and uptake of the educational program for anaesthesia. RESULTS: Out of the 2,179 CDs performed in the intervention facilities from 2016 to 2019, two women died from complications of anaesthesia. The risk of death from anaesthetic complications was 0.9 per 1000 CD (95% CI 0.1-3.3. The risk of death was not established in the control group because of inadequate documentation and records keeping. The proportion of CD performed under spinal anaesthesia in intervention facilities doubled from 28% (60/214 with 95% CI 22-35) at baseline (July 2014 - June 2016) to 57% (558/971 with 95% CI of 54-61) in year three (July 2018 - June 2019), while in the control group increased by only 40% from 19% (92/475 with 95% CI of 16-23) at baseline and 27% (68/251 with 95% CI of 22-33) in year three. In 2020I, this educational training program was then adopted by the government with minor content changes and increasing duration of training to six months. CONCLUSIONS: This three month educational training program for associate clinicians in anaesthesia, complemented by supportive supervision, can increase the CD rate to one that fills the "unmet need" and the proportion of operations performed under spinal anaesthesia, the gold standard technique for CD. The program can be used to meet the urgent demand for anaesthesia services in other underserved areas in Africa.
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Raquianestesia , Anestesiologia , Gravidez , Humanos , Feminino , Tanzânia/epidemiologia , Estudos de Coortes , AnestesiologistasRESUMO
Lactic acid bacteria (LAB), widely used as starter cultures for the fermentation of a large variety of food, can improve the safety, shelf life, nutritional value and overall quality of the fermented products. In this regard, the selection of strains delivering health-promoting compounds is now the main objective of many researchers. Although most LAB are auxotrophic for several vitamins, it is known that certain strains have the capability to synthesize B-group vitamins. This is an important property since humans cannot synthesize most vitamins, and these could be obtained by consuming LAB fermented foods. This review discusses the use of LAB as an alternative to fortification by the chemical synthesis to increase riboflavin and folate concentrations in food. Moreover, it provides an overview of the recent applications of vitamin-producing LAB with anti-inflammatory/antioxidant activities against gastrointestinal tract inflammation. This review shows the potential uses of riboflavin and folates producing LAB for the biofortification of food, as therapeutics against intestinal pathologies and to complement anti-inflammatory/anti-neoplastic treatments.
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Ácido Fólico/biossíntese , Alimentos Fortificados , Doenças Inflamatórias Intestinais/terapia , Lactobacillales/metabolismo , Mucosite/terapia , Riboflavina/biossíntese , Animais , Antioxidantes/análise , Fermentação , Alimentos Fermentados , Ácido Fólico/análise , Humanos , Lactobacillales/isolamento & purificação , Riboflavina/análise , Vitaminas/análise , Vitaminas/biossínteseRESUMO
AIMS: To evaluate a mixture of selected lactic acid bacteria (LAB) (a riboflavin-producer, a folate-producer and an immunomodulatory strain) as co-adjuvant for 5-fluorouracil (5-FU) chemotherapy in cell culture and using a 4T1 cell animal model of breast cancer. METHODS AND RESULTS: The viability of Caco-2 cells exposed to 5-FU and/or LAB was analysed. Mice bearing breast tumour were treated with 5-FU and/or LAB. Tumour growth was measured. Intestinal mucositis (IM) was evaluated in small intestine; haematological parameters and plasma cytokines were determined. The bacterial mixture did not negatively affect the cytotoxic activity of 5-FU on Caco-2 cells. The LAB mixture attenuated the IM and prevented blood cell decreases associated with 5-FU treatment. Mice that received 5-FU and LAB mixture decreased tumour growth and showed modulation of systemic cytokines modified by both tumour growth and 5-FU treatment. The LAB mixture by itself delayed tumour growth. CONCLUSIONS: The mixture of selected LAB was able to reduce the side-effects associated with chemotherapy without affecting its primary anti-tumour activity. SIGNIFICANCE AND IMPACT OF THE STUDY: This bacterial mixture could prevent the interruption of conventional oncologic therapies by reducing undesirable side-effects. In addition, this blend would provide essential nutrients (vitamins) to oncology patients.
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Adjuvantes Imunológicos , Neoplasias da Mama/terapia , Fluoruracila/uso terapêutico , Lactobacillales/imunologia , Lactobacillales/metabolismo , Animais , Antineoplásicos/uso terapêutico , Células CACO-2 , Linhagem Celular , Sobrevivência Celular , Citocinas/sangue , Modelos Animais de Doenças , Feminino , Ácido Fólico/metabolismo , Humanos , Imunomodulação , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Camundongos , Camundongos Endogâmicos BALB C , Mucosite/microbiologia , Mucosite/patologia , Riboflavina/metabolismo , VitaminasRESUMO
The ground state of the Hubbard model with nearest-neighbor hopping on the square lattice at half filling is known to be that of an antiferromagnetic (AFM) band insulator for any on-site repulsion. At finite temperature, the absence of long-range order makes the question of how the interaction-driven insulator is realized nontrivial. We address this problem with controlled accuracy in the thermodynamic limit using self-energy diagrammatic determinant Monte Carlo and dynamical cluster approximation methods and show that development of long-range AFM correlations drives an extended crossover from Fermi liquid to insulating behavior in the parameter regime that precludes a metal-to-insulator transition. The intermediate crossover state is best described as a non-Fermi liquid with a partially gapped Fermi surface.
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BACKGROUND: Recent studies have demonstrated the possibility of negative associations between prior influenza vaccines and subsequent influenza vaccine effectiveness (VE), depending on season and strain. We investigated this association over 4 consecutive influenza seasons (2011-2012 through 2014-2015) in Canada. METHODS: Using a matched test-negative design, laboratory-confirmed influenza cases and matched test-negative controls admitted to hospitals were enrolled. Patients were stratified into 4 groups according to influenza vaccine history (not vaccinated current and prior season [referent], vaccinated prior season only, vaccinated current season only, and vaccinated both current and prior season). Conditional logistic regression was used to estimate VE; prior vaccine impact was assessed each season for overall effect and effect stratified by age (<65 years, ≥65 years) and type/subtype (A/H1N1, A/H3N2, influenza B). RESULTS: Overall, mainly nonsignificant associations were observed. Trends of nonsignificant decreased VE among patients repeatedly vaccinated in both prior and current season relative to the current season only were observed in the A/H3N2-dominant seasons of 2012-2013 and 2014-2015. Conversely, in 2011-2012, during which B viruses circulated, and in 2013-2014, when A/H1N1 circulated, being vaccinated in both seasons tended to result in a high VE in the current season against the dominant circulating subtype. CONCLUSIONS: Prior vaccine impact on subsequent VE among Canadian inpatients was mainly nonsignificant. Even in circumstances where we observed a trend of negative impact, being repeatedly vaccinated was still more effective than not receiving the current season's vaccine. These findings favor continuation of annual influenza vaccination recommendations, particularly in older adults. CLINICAL TRIALS REGISTRATION: NCT01517191.
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Hospitalização , Vacinas contra Influenza/imunologia , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Estações do Ano , Vacinação , Idoso , Idoso de 80 Anos ou mais , Canadá/epidemiologia , Estudos de Casos e Controles , Feminino , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza B/imunologia , Vacinas contra Influenza/administração & dosagem , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Vigilância em Saúde Pública , Fatores de RiscoRESUMO
RATIONALE: Laser microdissection-liquid vortex capture/electrospray ionization mass spectrometry (LMD-LVC/ESI-MS) has potential for on-line classification of tissue but an investigation into what analytical conditions provide best spectral differentiation has not been conducted. The effects of solvent, ionization polarity, and spectral acquisition parameters on differentiation of mouse brain tissue regions are described. METHODS: Individual 40 × 40 µm microdissections from cortex, white, grey, granular, and nucleus regions of mouse brain tissue were analyzed using different capture/ESI solvents, in positive and negative ion mode ESI, using time-of-flight (TOF)-MS and sequential window acquisitions of all theoretical spectra (SWATH)-MS (a permutation of tandem-MS), and combinations thereof. Principal component analysis-linear discriminant analysis (PCA-LDA), applied to each mass spectral dataset, was used to determine the accuracy of differentiation of mouse brain tissue regions. RESULTS: Mass spectral differences associated with capture/ESI solvent composition manifested as altered relative distributions of ions rather than the presence or absence of unique ions. In negative ion mode ESI, 80/20 (v/v) methanol/water yielded spectra with low signal/noise ratios relative to other solvents. PCA-LDA models acquired using 90/10 (v/v) methanol/chloroform differentiated tissue regions with 100% accuracy while data collected using methanol misclassified some samples. The combination of SWATH-MS and TOF-MS data improved differentiation accuracy. CONCLUSIONS: Combined TOF-MS and SWATH-MS data differentiated white, grey, granular, and nucleus mouse tissue regions with greater accuracy than when solely using TOF-MS data. Using 90/10 (v/v) methanol/chloroform, tissue regions were perfectly differentiated. These results will guide future studies looking to utilize the potential of LMD-LVC/ESI-MS for tissue and disease differentiation.
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AIM: To evaluate two folate-producing strains, Streptococcus (Strep.) thermophilus CRL 808 and Strep. thermophilus CRL 415, against chemically induced mucositis in mice. METHODS AND RESULTS: In vitro assays with Caco-2 cells were performed to evaluate the effect of the bacteria in the presence of 5-fluorouracil (5-FU). For in vivo studies, mice were daily injected with 5-FU to induce intestinal mucositis (IM) and orally administered with folate-producing strains during 6 days. Clinical symptoms, histological parameters and cytokine profiles were assessed. The results showed that Strep. thermophilus CRL 808 increased the cytotoxicity of 5-FU against Caco-2 cells. Administration of this strain in mice with chemically induced IM resulted in a reduction in diarrhoea score and restoration of the intestinal architecture. Cytokine analysis showed that the anti-inflammatory effect by the bacterium is not associated with an immune mechanism. Regarding Strep. thermophilus CRL 415, no improvements were observed in any of the parameters evaluated. CONCLUSION: The administration of the folate-producing Strep. thermophilus CRL 808 has the potential to prevent IM induced by 5-FU in mice. SIGNIFICANCE AND IMPACT OF THE STUDY: Folate-producing LAB could be used in chemotherapy patients to reduce the symptoms of IM, improve their nutritional status and increase the effectiveness of 5-FU.
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Ácido Fólico/biossíntese , Lactobacillales/metabolismo , Mucosite/terapia , Probióticos/uso terapêutico , Animais , Células CACO-2 , Citocinas/metabolismo , Diarreia/prevenção & controle , Fluoruracila , Humanos , Inflamação/patologia , Mucosa Intestinal/patologia , Intestinos/patologia , Lactobacillales/genética , Camundongos , Mucosite/induzido quimicamente , Streptococcus thermophilus/genética , Streptococcus thermophilus/metabolismoRESUMO
AIM: To assess the anti-inflammatory effect associated with individual probiotic suspensions of riboflavin-producing lactic acid bacteria (LAB) in a colitis murine model. METHODS AND RESULTS: Mice intrarectally inoculated with trinitrobenzene sulfonic acid (TNBS) were orally administered with individual suspensions of riboflavin-producing strains: Lactobacillus (Lact.) plantarum CRL2130, Lact. paracasei CRL76, Lact. bulgaricus CRL871 and Streptococcus thermophilus CRL803; and a nonriboflavin-producing strain or commercial riboflavin. The extent of colonic damage and inflammation and microbial translocation to liver were evaluated. iNOs enzyme was analysed in the intestinal tissues and cytokine concentrations in the intestinal fluids. Animals given either one of the four riboflavin-producing strains showed lower macroscopic and histologic damage scores, lower microbial translocation to liver, significant decreases of iNOs+ cells in their large intestines and decreased proinflammatory cytokines, compared with mice without treatment. The administration of pure riboflavin showed similar benefits. Lact. paracasei CRL76 accompanied its anti-inflammatory effect with increased IL-10 levels demonstrating other beneficial properties in addition to the vitamin production. CONCLUSION: Administration of riboflavin-producing strains prevented the intestinal damage induced by TNBS in mice. SIGNIFICANCE AND IMPACT OF THE STUDY: Riboflavin-producing phenotype in LAB represents a potent tool to select them for preventing/treating IBD.
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Colite/tratamento farmacológico , Lactobacillus/metabolismo , Probióticos/administração & dosagem , Riboflavina/metabolismo , Streptococcus thermophilus/metabolismo , Animais , Colite/induzido quimicamente , Colite/genética , Colite/imunologia , Fezes/microbiologia , Feminino , Humanos , Interleucina-10/genética , Interleucina-10/imunologia , Intestinos/imunologia , Intestinos/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Ácido Trinitrobenzenossulfônico/efeitos adversosRESUMO
OBJECTIVES: The Montreal Cognitive Assessement (MoCA) is a brief and standardized cognitive screening tool that has been used with several clinical populations. The aim of this study was to screen the early cognitive status of patients following mild traumatic brain injury (mTBI) with the MoCA. METHODS: The MoCA was administered within the first 2 weeks post-injury to 42 patients with uncomplicated mTBI, 92 patients with complicated mTBI and 50 healthy controls. RESULTS: Patients with complicated mTBI had a significantly lower performance (more impairments) on the total score of the MoCA than both the group with uncomplicated mTBI and the control group. Also, the group with uncomplicated mTBI had a significantly lower performance than controls. Moreover, age, education and TBI severity had a significant effect on the MoCA total score where younger, more educated and patients with less severe (higher GCS score) mTBI performed significantly better. CONCLUSIONS: The MoCA may be clinically useful to acutely screen cognition following mTBI.
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Tatton-Brown-Rahman syndrome (TBRS) was recently described in 13 isolated cases with de novo mutations in the DNMT3A gene. This autosomal dominant condition is characterized by tall stature, intellectual disability and a distinctive facial appearance. Here, we report six cases of inherited TBRS caused by novel DNMT3A germline mutations. The affected individuals belong to two sib-ships: four from an Old Order Amish family in America and two from a French Canadian family in Canada. All of them presented with characteristic features of TBRS, including dysmorphic facial features, increased height, intellectual disability, and variable additional features. We performed clinical exome sequencing and identified two mutations in the DNMT3A gene, a c.2312G>A (p.Arg771Gln) missense mutation in the Amish family and a c.2296_2297delAA (p.Lys766Glufs*15) small deletion in the French Canadian family. Parental DNA analysis by Sanger sequencing revealed that the Amish mutation was inherited from the healthy mosaic father. This study reflects the first cases with inherited TBRS and expands the phenotypic spectrum of TBRS.
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DNA (Citosina-5-)-Metiltransferases/genética , Predisposição Genética para Doença , Mutação em Linhagem Germinativa/genética , Deficiência Intelectual/genética , Adolescente , Adulto , Canadá , Criança , DNA Metiltransferase 3A , Exoma/genética , Fácies , Feminino , Heterozigoto , Humanos , Deficiência Intelectual/fisiopatologia , Masculino , Pessoa de Meia-Idade , Linhagem , Análise de Sequência de DNARESUMO
OBJECTIVE: The goal of this study was to identify factors that would predict short-term neuropsychological outcome in patients with traumatic brain injury (TBI) hospitalized in an acute rehabilitation setting. METHODS: Data was collected in the context of an acute early rehabilitation setting of a trauma centre. A brief neuropsychological assessment was carried out for 348 patients within a month following their trauma. RESULTS: Length of post-traumatic amnesia (PTA) was the best predictor of behavioural, memory and executive function variables within a month post TBI. The odds of being agitated, labile, irritable and disinhibited at one month post trauma were almost six times higher for those with PTA that lasted more than 7 days compared to those with a PTA of less than 24 hours. Also, the odds of having a higher mental manipulation score (less significant executive function impairment) were almost two times lower for those with frontal lesions, and three to six times lower for those with PTA of more than 24 hours. In addition, TBI severity, education and age were considered good predictors of some aspects of neuropsychological outcome. CONCLUSION: This model may help clinicians and administrators recognize the probable post-traumatic deficits as quickly as possible and to plan interventions as well as post-acute discharge orientation accordingly and early on.
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Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/reabilitação , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/etiologia , Transtornos Mentais/diagnóstico , Transtornos Mentais/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Função Executiva/fisiologia , Feminino , Escala de Coma de Glasgow , Humanos , Masculino , Memória/fisiologia , Pessoa de Meia-Idade , Testes Neuropsicológicos , Valor Preditivo dos Testes , Estatísticas não Paramétricas , Tomógrafos Computadorizados , Adulto JovemRESUMO
In this technical note, we demonstrate the hyphenation of production-scale free-flow electrophoresis (FFE) and sheathless electrospray ionization mass spectrometry (ESI-MS). In contrast to previous hyphenation approaches, we used a highly conductive background electrolyte (BGE) required for production-scale FFE. We found that this kind of BGE as well as a production-scale setup leads to significant electric interference between FFE and MS. This interference prevents steady-state FFE operation. We examine this interference in detail and discuss possible solutions to this issue. We demonstrate that the straightforward grounding of the transfer line removes the influence of ESI-MS on FFE, but creates a current leak from the ESI interface, which adversely affects the ESI spray. Furthermore, we show that only the electrical disconnection of the ESI probe from the FFE-MS transfer line suppresses this undesirable current. In order to facilitate the electrical disconnection we used a low conductivity, silica-based ESI probe with withdrawn inner capillary. This approach allowed the interference-free hyphenation of production-scale FFE (using a highly conductive BGE) with ESI-MS.
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It has been previously shown that Lactobacillus plantarum CRL 2130 is able to produce riboflavin in soyamilk. The aim of the present study was to evaluate the efficiency of this riboflavin-bio-enriched soyamilk to revert and/or prevent the nutritional deficiency of riboflavin using different animal models. When used to supplement the diets of previously depleted animals, it was shown that the growth, riboflavin status and morphology of the small intestines reverted to normal parameters and were similar to animals supplemented with commercial riboflavin. In the prevention model, the same tendency was observed, where animals that received soyamilk fermented with L. plantarum CRL 2130 did not show signs of riboflavin deficiency. This new bio-fortified soya-based product could be used as part of normal diets to provide a more natural alternative to mandatory fortification with riboflavin for the prevention of its deficiency.
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Fermentação , Lactobacillus plantarum/metabolismo , Deficiência de Riboflavina/prevenção & controle , Riboflavina/biossíntese , Leite de Soja/química , Animais , Dieta , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Riboflavina/administração & dosagem , Deficiência de Riboflavina/etiologia , Leite de Soja/metabolismoRESUMO
AIMS: To evaluate the beneficial properties of a potentially probiotic yoghurt obtained by the fermentation of two selected anti-inflammatory bacterial strains using in vivo mouse models of intestinal inflammation and colon carcinogenesis. METHODS AND RESULTS: Yoghurt was administered to mice suffering chemically induced intestinal inflammation or colon carcinogenesis. It was shown that this novel yoghurt was able to prevent local inflammation in the intestines of mice through a regulation of the immune response, prevent macroscopic and histological damages, and prevent colon carcinogenesis through an anti-inflammatory response. CONCLUSIONS: The developed yoghurt showed in vivo anti-inflammatory properties by modulation of the host immune response for the prevention of colon inflammation and carcinogenesis. SIGNIFICANCE AND IMPACT OF THE STUDY: This new yoghurt could thus be considered a probiotic food and be useful as a complement to current treatment protocols for inflammatory bowel diseases and colon cancer, a first since there are no current functional foods specifically oriented for these patients.
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Colite/prevenção & controle , Neoplasias do Colo/prevenção & controle , Probióticos/administração & dosagem , Iogurte/microbiologia , Animais , Carcinogênese , Colite/imunologia , Colite/microbiologia , Neoplasias do Colo/imunologia , Neoplasias do Colo/microbiologia , Feminino , Fermentação , Humanos , Intestinos/imunologia , Intestinos/microbiologia , Ácido Láctico/metabolismo , Lactobacillaceae/imunologia , Lactobacillaceae/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Probióticos/classificação , Probióticos/isolamento & purificaçãoRESUMO
We compute the two-particle quantities relevant for superconducting correlations in the two-dimensional Hubbard model within the dynamical cluster approximation. In the normal state we identify the parameter regime in density, interaction, and second-nearest-neighbor hopping strength that maximizes the d_{x^{2}-y^{2}} superconducting transition temperature. We find in all cases that the optimal transition temperature occurs at intermediate coupling strength, and is suppressed at strong and weak interaction strengths. Similarly, superconducting fluctuations are strongest at intermediate doping and suppressed towards large doping and half filling. We find a change in sign of the vertex contributions to d_{xy} superconductivity from repulsive near half filling to attractive at large doping. p-wave superconductivity is not found at the parameters we study, and s-wave contributions are always repulsive. For negative second-nearest-neighbor hopping the optimal transition temperature shifts towards the electron-doped side in opposition to the van Hove singularity, which moves towards hole doping. We surmise that an increase of the local interaction of the electron-doped compounds would increase T_{c}.
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We demonstrate how to identify which physical processes dominate the low-energy spectral functions of correlated electron systems. We obtain an unambiguous classification through an analysis of the equation of motion for the electron self-energy in its charge, spin, and particle-particle representations. Our procedure is then employed to clarify the controversial physics responsible for the appearance of the pseudogap in correlated systems. We illustrate our method by examining the attractive and repulsive Hubbard model in two dimensions. In the latter, spin fluctuations are identified as the origin of the pseudogap, and we also explain why d-wave pairing fluctuations play a marginal role in suppressing the low-energy spectral weight, independent of their actual strength.
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OBJECTIVE: To study the acute relationship between olfactory function and traumatic brain injury (TBI), cognitive functions and outcome. METHODS: Sixty-two patients with TBI were evaluated within the first 2 weeks following TBI. The Sniffin'Sticks identification test was used to assess olfaction. A neuropsychological evaluation was carried out to assess attention, verbal fluency, naming, memory, problem-solving and mental flexibility. The extended Glasgow Outcome Scale (GOSE) and the Disability Rating Scale (DRS) were rated at discharge from acute care. RESULTS: Traumatic lesions located in the basal frontal area resulted in odour identification scores that were significantly lower than when lesions were elsewhere (p < 0.001). A significant positive correlation was shown between odour identification scores and mental flexibility scores (p = 0.004) and patients with hyposmia had worse performances on executive tests measuring problem-solving, verbal fluency and mental flexibility (p < 0.01). Moreover, the odour identification score and the DRS total score were related (p = 0.019). CONCLUSIONS: These findings add information regarding acute olfactory status following TBI and provide evidence on the importance of assessing olfaction very early post-TBI in order to plan intervention and determine what accident prevention advice will be required for home or work re-integration.
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Lesões Encefálicas/fisiopatologia , Função Executiva/fisiologia , Transtornos do Olfato/fisiopatologia , Olfato/fisiologia , Adolescente , Adulto , Idoso , Cognição/fisiologia , Feminino , Escala de Resultado de Glasgow , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Transtornos do Olfato/etiologia , Estudos RetrospectivosRESUMO
In this study, Lactococcus lactis was engineered to express mutated internalin A on its surface and to secrete large amounts of listeriolysin O (LLO) in order to improve its potential as a vehicle for DNA vaccination. Western blotting experiments demonstrated that the bacterium expressed LLO in both the cytoplasmic and extracellular compartments, with higher quantities found in the culture supernatants. A hemolytic assay showed that the recombinant strain secreted 250 ng active LLO/mg total protein. This mInlA/LLO-producing strain of L. lactis may be used as an alternative tool in DNA vaccination against a number of infectious diseases or in cancer therapy.
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Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Toxinas Bacterianas/genética , Toxinas Bacterianas/imunologia , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/imunologia , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/imunologia , Lactococcus lactis/genética , Listeria monocytogenes/imunologia , Mutação , Proteínas Recombinantes , Vacinas Bacterianas , Membrana Celular/metabolismo , Expressão Gênica , Hemólise , Lactococcus lactis/metabolismo , VacinaçãoRESUMO
Studying the kinetics of reversible protein-small molecule binding is a major challenge. The available approaches require that either the small molecule or the protein be modified by labeling or immobilization on a surface. Not only can such modifications be difficult to do but also they can drastically affect the kinetic parameters of the interaction. To solve this problem, we present kinetic size-exclusion chromatography with mass spectrometry detection (KSEC-MS), a solution-based label-free approach. KSEC-MS utilizes the ability of size-exclusion chromatography (SEC) to separate any small molecule from any protein-small molecule complex without immobilization and the ability of mass spectrometry (MS) to detect a small molecule without a label. The rate constants of complex formation and dissociation are deconvoluted from the temporal pattern of small molecule elution measured with MS at the exit from the SEC column. This work describes the concept of KSEC-MS and proves it in principle by measuring the rate constants of interaction between carbonic anhydrase and acetazolamide.
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Cromatografia em Gel/métodos , Espectrometria de Massas/métodos , Proteínas/química , CinéticaRESUMO
OBJECTIVES: Cornelia de Lange syndrome (CdLS) is characterized by distinct facial features, growth retardation, upper limb reduction defects, hirsutism, and intellectual disability. NIPBL mutations have been identified in approximately 60% of patients with CdLS diagnosed postnatally. Prenatal ultrasound findings include upper limb reduction defects, intrauterine growth restriction, and micrognathia. CdLS has also been associated with decreased PAPP-A and increased nuchal translucency (NT). We reviewed NIPBL sequence analysis results for 12 prenatal samples in our laboratory to determine the frequency of mutations in our cohort. METHODS: This retrospective study analyzed data from all 12 prenatal cases with suspected CdLS, which were received by The University of Chicago Genetic Services Laboratories. Diagnostic NIPBL sequencing was performed for all samples. Clinical information was collected from referring physicians. RESULTS: NIPBL mutations were identified in 9 out of the 12 cases prenatally (75%). Amongst the NIPBL mutation-positive cases with clinical information available, the most common findings were upper limb malformations and micrognathia. Five patients had NT measurements in the first trimester, of which four were noted to be increased. CONCLUSION: We demonstrate that prenatally-detected phenotypes of CdLS, particularly severe micrognathia and bilateral upper limb defects, are associated with an increased frequency of NIPBL mutations.