RESUMO
Morphological study of the neuromuscular junction (NMJ), a specialised peripheral synapse formed between a lower motor neuron and skeletal muscle fibre, has significantly contributed to the understanding of synaptic biology and neuromuscular disease pathogenesis. Rodent NMJs are readily accessible, and research into conditions such as amyotrophic lateral sclerosis (ALS), Charcot-Marie-Tooth disease (CMT), and spinal muscular atrophy (SMA) has relied heavily on experimental work in these small mammals. However, given that nerve length dependency is an important feature of many peripheral neuropathies, these rodent models have clear shortcomings; large animal models might be preferable, but their size presents novel anatomical challenges. Overcoming these constraints to study the NMJ morphology of large mammalian distal limb muscles is of prime importance to increase cross-species translational neuromuscular research potential, particularly in the study of long motor units. In the past, NMJ phenotype analysis of large muscle bodies within the equine distal pelvic limb, such as the tibialis cranialis, or within muscles of high fibrous content, such as the soleus, has posed a distinct experimental hurdle. We optimised a technique for NMJ location and dissection from equine pelvic limb muscles. Using a quantification method validated in smaller species, we demonstrate their morphology and show that equine NMJs can be reliably dissected, stained and analysed. We reveal that the NMJs within the equine soleus have distinctly different morphologies when compared to the extensor digitorum longus and tibialis cranialis muscles. Overall, we demonstrate that equine distal pelvic limb muscles can be regionally dissected, with samples whole-mounted and their innervation patterns visualised. These methods will allow the localisation and analysis of neuromuscular junctions within the muscle bodies of large mammals to identify neuroanatomical and neuropathological features.
Assuntos
Corantes , Doenças do Sistema Nervoso Periférico , Animais , Cavalos , Mamíferos , Neurônios Motores/patologia , Fibras Musculares Esqueléticas , Músculo Esquelético/patologia , Junção Neuromuscular/patologia , Doenças do Sistema Nervoso Periférico/patologiaRESUMO
BACKGROUND: Most patients with ovarian cancer will relapse after receiving frontline platinum-based chemotherapy and eventually develop platinum-resistant or platinum-refractory disease. We report results of avelumab alone or avelumab plus pegylated liposomal doxorubicin (PLD) compared with PLD alone in patients with platinum-resistant or platinum-refractory ovarian cancer. METHODS: JAVELIN Ovarian 200 was an open-label, parallel-group, three-arm, randomised, phase 3 trial, done at 149 hospitals and cancer treatment centres in 24 countries. Eligible patients were aged 18 years or older with epithelial ovarian, fallopian tube, or peritoneal cancer (maximum of three previous lines for platinum-sensitive disease, none for platinum-resistant disease) and an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients were randomly assigned (1:1:1) via interactive response technology to avelumab (10 mg/kg intravenously every 2 weeks), avelumab plus PLD (40 mg/m2 intravenously every 4 weeks), or PLD and stratified by disease platinum status, number of previous anticancer regimens, and bulky disease. Primary endpoints were progression-free survival by blinded independent central review and overall survival in all randomly assigned patients, with the objective to show whether avelumab alone or avelumab plus PLD is superior to PLD. Safety was assessed in all patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, NCT02580058. The trial is no longer enrolling patients and this is the final analysis of both primary endpoints. FINDINGS: Between Jan 5, 2016, and May 16, 2017, 566 patients were enrolled and randomly assigned (combination n=188; PLD n=190, avelumab n=188). At data cutoff (Sept 19, 2018), median duration of follow-up for overall survival was 18·4 months (IQR 15·6-21·9) for the combination group, 17·4 months (15·2-21·3) for the PLD group, and 18·2 months (15·8-21·2) for the avelumab group. Median progression-free survival by blinded independent central review was 3·7 months (95% CI 3·3-5·1) in the combination group, 3·5 months (2·1-4·0) in the PLD group, and 1·9 months (1·8-1·9) in the avelumab group (combination vs PLD: stratified HR 0·78 [repeated 93·1% CI 0·59-1·24], one-sided p=0·030; avelumab vs PLD: 1·68 [1·32-2·60], one-sided p>0·99). Median overall survival was 15·7 months (95% CI 12·7-18·7) in the combination group, 13·1 months (11·8-15·5) in the PLD group, and 11·8 months (8·9-14·1) in the avelumab group (combination vs PLD: stratified HR 0·89 [repeated 88·85% CI 0·74-1·24], one-sided p=0·21; avelumab vs PLD: 1·14 [0·95-1·58], one-sided p=0·83]). The most common grade 3 or worse treatment-related adverse events were palmar-plantar erythrodysesthesia syndrome (18 [10%] in the combination group vs nine [5%] in the PLD group vs none in the avelumab group), rash (11 [6%] vs three [2%] vs none), fatigue (ten [5%] vs three [2%] vs none), stomatitis (ten [5%] vs five [3%] vs none), anaemia (six [3%] vs nine [5%] vs three [2%]), neutropenia (nine [5%] vs nine [5%] vs none), and neutrophil count decreased (eight [5%] vs seven [4%] vs none). Serious treatment-related adverse events occurred in 32 (18%) patients in the combination group, 19 (11%) in the PLD group, and 14 (7%) in the avelumab group. Treatment-related adverse events resulted in death in one patient each in the PLD group (sepsis) and avelumab group (intestinal obstruction). INTERPRETATION: Neither avelumab plus PLD nor avelumab alone significantly improved progression-free survival or overall survival versus PLD. These results provide insights for patient selection in future studies of immune checkpoint inhibitors in platinum-resistant or platinum-refractory ovarian cancer. FUNDING: Pfizer and Merck KGaA, Darmstadt, Germany.
Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Inibidores de Checkpoint Imunológico/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológico , Compostos de Platina/uso terapêutico , Idoso , Anticorpos Monoclonais Humanizados/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Progressão da Doença , Intervalo Livre de Doença , Doxorrubicina/análogos & derivados , Doxorrubicina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Pessoa de Meia-Idade , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/mortalidade , Compostos de Platina/efeitos adversos , Polietilenoglicóis/uso terapêutico , Fatores de TempoRESUMO
Teachers' stress is a dynamic combination of the individual teacher's characteristics and characteristics of the classroom and school environment. To date, there are limited studies on teachers' stress in the context of lower-middle-income countries (LMICs), where working conditions as well as general political and economic circumstances might pose a considerable threat for teachers' well-being. This study explores whether certain combinations of individual and environmental experiences of teachers in LMICs may result in stress, assessed as patterns of diurnal cortisol rhythm. Participants were kindergarten teachers in Kosovo and Ukraine, two LMICs in Europe. Latent Profile Analysis identified three subgroups of teachers that significantly differed on teachers' education and experience. Preliminary results of Latent Growth Modeling suggested differences between profiles in baseline waking cortisol and patterns of diurnal decline. Teachers in the profile that was characterized by the longest experience working in the field but the lowest level of education showed blunted cortisol in the morning and a flatter slope; a pattern that could indicate a maladaptive cortisol response. Future directions for studying stress processes among teachers in LMICs and implications for policy and practice on how to support teacher well-being in low-resource contexts are discussed.
Assuntos
Ritmo Circadiano , Hidrocortisona/metabolismo , Professores Escolares/psicologia , Estresse Psicológico/metabolismo , Adulto , Países Desenvolvidos , Escolaridade , Feminino , Humanos , Kosovo/epidemiologia , Análise de Classes Latentes , Pessoa de Meia-Idade , Pobreza/estatística & dados numéricos , Saliva/química , Estresse Psicológico/psicologia , Fatores de Tempo , Uso de Tabaco/epidemiologia , Ucrânia/epidemiologiaRESUMO
OBJECTIVE: To determine whether resistance training to improve mobility outcomes after stroke adheres to the American College of Sports Medicine (ACSM) guidelines, and whether adherence was associated with better outcomes. DATA SOURCES: Online databases searched from 1975 to October 30, 2016. STUDY SELECTION: Randomized controlled trials examining the effectiveness of lower limb strength training on mobility outcomes in adult participants with stroke. DATA EXTRACTION: Two independent reviewers completed data extraction. Quality of trials was determined using the Cochrane Risk of Bias Tool. Trials were scored based on their protocol's adherence to 8 ACSM recommendations. To determine if a relation existed between total adherence score and effect size, Spearman ρ was calculated, and between individual recommendations and effect size, Mann-Whitney U or Kruskal-Wallis tests were used. DATA SYNTHESIS: Thirty-nine trials met the inclusion criteria, and 34 were scored on their adherence to the guidelines. Adherence was high for frequency of training (100% of studies), but few trials adhered to the guidelines for intensity (32%), specificity (24%), and training pattern (3%). Based on the small number of studies that could be included in pooled analysis (n=12), there was no relation between overall adherence and effect size (Spearman ρ=-.39, P=.21). CONCLUSIONS: Adherence to the ACSM guidelines for resistance training after stroke varied widely. Future trials should ensure strength training protocols adhere more closely to the guidelines, to ensure their effectiveness in stroke can be accurately determined.
Assuntos
Fidelidade a Diretrizes/estatística & dados numéricos , Treinamento Resistido/normas , Medicina Esportiva/normas , Reabilitação do Acidente Vascular Cerebral/normas , Feminino , Humanos , Masculino , Ensaios Clínicos Controlados Aleatórios como Assunto , Treinamento Resistido/métodos , Sensibilidade e Especificidade , Estatísticas não Paramétricas , Acidente Vascular Cerebral/fisiopatologia , Reabilitação do Acidente Vascular Cerebral/métodosRESUMO
Characterisation of 27 types of biomass was performed together with an assessment of regional resource availability. Charcoal was produced under two conditions from all samples and their yields were compared. Sugarcane bagasse, sal and pine produced the best charcoal with a low volatile matter and high calorific value. The amount of high-quality charcoal which can be made within Nepal from the biomass types tested is equivalent to 8,073,000 tonnes of firewood a year or 51% of the yearly demand. The areas which would benefit the most from charcoal making facilities are the Mid-hills of the Western, Central and Eastern Development Regions, as well as the Terai in the Central and Eastern Development Regions. The main potential benefit is to convert agricultural residues which are underutilised because, in their original form, produce large quantities of smoke, to cleaner burning charcoal. The conversion of agricultural residues to charcoal is also a viable alternative to anaerobic digestion in the Mid-hills.
Assuntos
Agricultura , Carvão Vegetal , Saccharum , Biomassa , Celulose , NepalRESUMO
BACKGROUND: Surgical site infections (SSIs) are wound infections that occur after an operative procedure. A preventable complication, they are costly and associated with poorer patient outcomes, increased mortality, morbidity and reoperation rates. Surgical wound irrigation is an intraoperative technique, which may reduce the rate of SSIs through removal of dead or damaged tissue, metabolic waste, and wound exudate. Irrigation can be undertaken prior to wound closure or postoperatively. Intracavity lavage is a similar technique used in operations that expose a bodily cavity; such as procedures on the abdominal cavity and during joint replacement surgery. OBJECTIVES: To assess the effects of wound irrigation and intracavity lavage on the prevention of surgical site infection (SSI). SEARCH METHODS: In February 2017 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase and EBSCO CINAHL Plus. We also searched three clinical trials registries and references of included studies and relevant systematic reviews. There were no restrictions on language, date of publication or study setting. SELECTION CRITERIA: We included all randomised controlled trials (RCTs) of participants undergoing surgical procedures in which the use of a particular type of intraoperative washout (irrigation or lavage) was the only systematic difference between groups, and in which wounds underwent primary closure. The primary outcomes were SSI and wound dehiscence. Secondary outcomes were mortality, use of systemic antibiotics, antibiotic resistance, adverse events, re-intervention, length of hospital stay, and readmissions. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies for inclusion at each stage. Two review authors also undertook data extraction, assessment of risk of bias and GRADE assessment. We calculated risk ratios or differences in means with 95% confidence intervals where possible. MAIN RESULTS: We included 59 RCTs with 14,738 participants. Studies assessed comparisons between irrigation and no irrigation, between antibacterial and non-antibacterial irrigation, between different antibiotics, different antiseptics or different non-antibacterial agents, or between different methods of irrigation delivery. No studies compared antiseptic with antibiotic irrigation. Surgical site infectionIrrigation compared with no irrigation (20 studies; 7192 participants): there is no clear difference in risk of SSI between irrigation and no irrigation (RR 0.87, 95% CI 0.68 to 1.11; I2 = 28%; 14 studies, 6106 participants). This would represent an absolute difference of 13 fewer SSIs per 1000 people treated with irrigation compared with no irrigation; the 95% CI spanned from 31 fewer to 10 more SSIs. This was low-certainty evidence downgraded for risk of bias and imprecision.Antibacterial irrigation compared with non-antibacterial irrigation (36 studies, 6163 participants): there may be a lower incidence of SSI in participants treated with antibacterial irrigation compared with non-antibacterial irrigation (RR 0.57, 95% CI 0.44 to 0.75; I2 = 53%; 30 studies, 5141 participants). This would represent an absolute difference of 60 fewer SSIs per 1000 people treated with antibacterial irrigation than with non-antibacterial (95% CI 35 fewer to 78 fewer). This was low-certainty evidence downgraded for risk of bias and suspected publication bias.Comparison of irrigation of two agents of the same class (10 studies; 2118 participants): there may be a higher incidence of SSI in participants treated with povidone iodine compared with superoxidised water (Dermacyn) (RR 2.80, 95% CI 1.05 to 7.47; low-certainty evidence from one study, 190 participants). This would represent an absolute difference of 95 more SSIs per 1000 people treated with povidone iodine than with superoxidised water (95% CI 3 more to 341 more). All other comparisons found low- or very low-certainty evidence of no clear difference between groups.Comparison of two irrigation techniques: two studies compared standard (non-pulsed) methods with pulsatile methods. There may, on average, be fewer SSIs in participants treated with pulsatile methods compared with standard methods (RR 0.34, 95% CI 0.19 to 0.62; I2 = 0%; two studies, 484 participants). This would represent an absolute difference of 109 fewer SSIs occurring per 1000 with pulsatile irrigation compared with standard (95% CI 62 fewer to 134 fewer). This was low-certainty evidence downgraded twice for risks of bias across multiple domains. Wound dehiscenceFew studies reported wound dehiscence. No comparison had evidence for a difference between intervention groups. This included comparisons between irrigation and no irrigation (one study, low-certainty evidence); antibacterial and non-antibacterial irrigation (three studies, very low-certainty evidence) and pulsatile and standard irrigation (one study, low-certainty evidence). Secondary outcomesFew studies reported outcomes such as use of systemic antibiotics and antibiotic resistance and they were poorly and incompletely reported. There was limited reporting of mortality; this may have been partially due to failure to specify zero events in participants at low risk of death. Adverse event reporting was variable and often limited to individual event types. The evidence for the impact of interventions on length of hospital stay was low or moderate certainty; where differences were seen they were too small to be clinically important. AUTHORS' CONCLUSIONS: The evidence base for intracavity lavage and wound irrigation is generally of low certainty. Therefore where we identified a possible difference in the incidence of SSI (in comparisons of antibacterial and non-antibacterial interventions, and pulsatile versus standard methods) these should be considered in the context of uncertainty, particularly given the possibility of publication bias for the comparison of antibacterial and non-antibacterial interventions. Clinicians should also consider whether the evidence is relevant to the surgical populations under consideration, the varying reporting of other prophylactic antibiotics, and concerns about antibiotic resistance.We did not identify any trials that compared an antibiotic with an antiseptic. This gap in the direct evidence base may merit further investigation, potentially using network meta-analysis; to inform the direction of new primary research. Any new trial should be adequately powered to detect a difference in SSIs in eligible participants, should use robust research methodology to reduce the risks of bias and internationally recognised criteria for diagnosis of SSI, and should have adequate duration and follow-up.
Assuntos
Infecção da Ferida Cirúrgica/prevenção & controle , Abscesso/epidemiologia , Antibacterianos/administração & dosagem , Anti-Infecciosos Locais/administração & dosagem , Combinação de Medicamentos , Humanos , Ácido Hipocloroso/administração & dosagem , Incidência , Povidona-Iodo/administração & dosagem , Ensaios Clínicos Controlados Aleatórios como Assunto , Hipoclorito de Sódio/administração & dosagem , Deiscência da Ferida Operatória/epidemiologia , Infecção da Ferida Cirúrgica/epidemiologia , Irrigação Terapêutica/métodosRESUMO
BACKGROUND: Local and international research has identified rural origin as an important reason why healthcare professionals (HCPs) work in rural areas, and in South Africa (SA) considerable effort has gone into recruiting and training rural-origin students. However, there is little information in the SA literature on where graduates supported by these initiatives work, and whether they contribute to the rural workforce long term. OBJECTIVE: To determine the number of years that rural-origin Umthombo Youth Development Foundation (UYDF)-supported graduates of different disciplines worked at rural public healthcare facilities (PHCFs). METHODS: A retrospective descriptive study reviewed work record data of 405 UYDF graduates, to calculate the number of years they worked at a rural PHCF. Data were analysed descriptively and presented in tables with totals and percentages. RESULTS: Ninety percent (363/405) of UYDF-supported graduates returned to work at a rural PHCF. High percentages of social workers (85%), optometrists (80%), speech therapists, nurses (72%) and dental therapists (70%) worked for ≥5 years at a rural PHCF, while only 13% of audiologists, 14% of doctors, 29% of pharmacists, and 28% of dentists and occupational therapists worked at a rural PHCF for ≥5 years. Ten percent (42/405) of graduates did not work at a rural PHCF at all. A total of 110/124 (89%) of doctors supported by UYDF had worked at a rural PHCF, with 32% (40/124) working at a rural PHCF for ≥3 years. Overall, 54% of UYDF-supported graduates (219/405) worked for ≥3 years at a rural PHCF, and 38.5% (157/405) worked for ≥5 years at rural PHCFs. The majority of UYDF graduates had contributed towards long-term staffing of rural PHCFs. Lack of professional development opportunities at rural PHCFs as well as the reduced number of funded posts at rural PHCFs reduced the effectiveness of the UYDF initiative. CONCLUSION: The UYDF Scholarship Scheme has shown that investment in rural students through a bonded scholarship can contribute to staffing rural PHCFs, as >90% of graduates worked at rural PHCFs, and for some disciplines >70% of graduates worked for ≥5 years at a rural PHCF. Allied HCPs worked on average for longer periods at rural PHCFs than doctors.
Assuntos
Bolsas de Estudo , Serviços de Saúde Rural , Adolescente , Humanos , Estudos Retrospectivos , África do Sul , Pessoal de Saúde , Recursos HumanosRESUMO
The field of non-surgical esthetic procedures has witnessed a significant surge in demand in recent years, with neuromodulators, skin treatments, and dermal fillers contributing significantly to the industry's growth. These procedures have become increasingly popular, reflecting the broader acceptance of esthetic enhancements in society. Neuromodulators play a pivotal role in facial rejuvenation, but they require precise knowledge of facial anatomy to optimize results and prevent complications. They include rare hypersensitivity reactions, local injection reactions, and brow and eyelid ptosis. Dermal fillers, both non-permanent and permanent, are widely used to restore volume and improve facial contours. However, they also carry risks, including bruising, temporary edema, and lumps. Permanent fillers present higher complication rates, and their use should be approached with caution. Vascular occlusion is a rare but severe complication associated with dermal fillers. To mitigate these risks, practitioners must have a comprehensive understanding of their compositions and potential complications. Overall, while non-surgical esthetic procedures offer remarkable results with minimal downtime, the importance of training, anatomic knowledge, and effective complication management cannot be overstated in ensuring patient safety and satisfaction in this evolving field of medicine.
Assuntos
Técnicas Cosméticas , Preenchedores Dérmicos , Humanos , Preenchedores Dérmicos/efeitos adversos , Técnicas Cosméticas/efeitos adversos , Ácido Hialurônico , Estética Dentária , Injeções Subcutâneas , Neurotransmissores , RejuvenescimentoRESUMO
Expanding the volume of an irreversible electroporation treatment typically necessitates an increase in pulse voltage, number, duration, or repetition. This study investigates the addition of polyethylenimine nanoparticles (PEI-NP) to pulsed electric field treatments, determining their combined effect on ablation size and voltages. U118 cells in an in vitro 3D cell culture model were treated with one of three pulse parameters (with and without PEI-NPs) which are representative of irreversible electroporation (IRE), high frequency irreversible electroporation (H-FIRE), or nanosecond pulsed electric fields (nsPEF). The size of the ablations were compared and mapped onto an electric field model to describe the electric field required to induce cell death. Analysis was conducted to determine the role of PEI-NPs in altering media conductivity, the potential for PEI-NP degradation following pulsed electric field treatment, and PEI-NP uptake. Results show there was a statistically significant increase in ablation diameter for IRE and H-FIRE pulses with PEI-NPs. There was no increase in ablation size for nsPEF with PEI-NPs. This all occurs with no change in cell media conductivity, no observable degradation of PEI-NPs, and moderate particle uptake. These results demonstrate the synergy of a combined cationic polymer nanoparticle and pulsed electric field treatment for the ablation of cancer cells. These results set the foundation for polymer nanoparticles engineered specifically for irreversible electroporation.
Assuntos
Técnicas de Ablação , Nanopartículas , Condutividade Elétrica , Eletroporação/métodos , PolímerosRESUMO
Intercellular signaling drives human development, but there is a paucity of in vitro models that recapitulate important tissue architecture while remaining operationally simple and scalable. As an example, formation of the upper lip and palate requires the orchestrated proliferation and fusion of embryonic facial growth centers and is dependent on paracrine epithelial-mesenchymal signaling through multiple pathways including the Sonic Hedgehog (SHH), transforming growth factor-beta (Tgf-ß), bone morphogenic protein (BMP), and epidermal growth factor (EGF) pathways. We have developed a robust, throughput-compatible microphysiological system to model intercellular signaling including epithelial-mesenchymal interactions that is useful for studying both normal and abnormal orofacial development. We describe the construction and operation of an engineered microplate created using CNC micromilling of 96-well microtiter plates capable of containing up to 20 epithelial-mesenchymal microtissues. A dense three-dimensional mesenchyme is created by embedding cells (O9-1, 3T3) in a biomimetic hydrogel. An epithelial layer is then overlayed on the microtissue by loading cells in engineered microchannels that flank the microtissue. The result is an engineering epithelial-mesenchymal interface that is both on and perpendicular to the imaging plane making it suitable for high-content imaging and analysis. The resulting microtissues and device are compatible with diverse analytical techniques including fluorescent and luminescent cell health and enzymatic reporter assays, gene expression analyses, and protein staining. This tractable model and approach promise to shed light on critical processes in intercellular signaling events in orofacial development and beyond.
Assuntos
Comunicação Celular , Proteínas Hedgehog , Humanos , Mesoderma , Palato , Fator de Crescimento Transformador betaRESUMO
OBJECTIVE: The aim of the present clinical pilot study was to examine the influence of a combination of micronutrients on individuals with high stress experience. METHODS: 40 healthy students (28 female, 12 male) with a mean age of 27.1 ± 3.0 years, experiencing high examination stress, were chosen. After approval of the ethics commission, one group of students (n = 19) took a combination of micronutrients (Orthomol vital m/f) for three months, whereas other students (n = 21) served as control group. All participants underwent at the beginning and at the end of the trial a dental examination, a determination of 10 periodontal pathogens, a salivary and a blood analysis. In addition, the participants filled in a questionnaire on nutrition, quality of life and degree of stress experienced during their final examinations. RESULTS: The evaluation of the results, obtained at the end of the trial period, showed that for all students a slight worsening of oral hygiene and an increased consumption of unhealthy food could be observed. The intake of the micronutrients led to a slight improvement of the degree of gingival inflammation in comparison to the control group. The blood analysis showed an increase in vitamin (vitamin C, vitamin E) and zinc concentrations, and a lower increase in CRP. In the male subjects, a decrease in the serum concentrations of triglycerides (p = 0.073) and LDL (p = 0.048) was observed. CONCLUSIONS: This pilot study shows that micronutrients, taken during periods of high stress experience, had a beneficial effect on inflammatory processes and helped reduce the level of some of the plasma lipids in males, and thus can be recommended for supplementing the diet. However, additional studies with a higher number of subjects, also suffering from periodontal disease, are necessary to show the effect of a micronutrient supplementation more clearly.
Assuntos
Micronutrientes/farmacologia , Saúde Bucal , Adulto , Análise Química do Sangue , Feminino , Gengiva/efeitos dos fármacos , Gengiva/patologia , Humanos , Inflamação/patologia , Masculino , Micronutrientes/administração & dosagem , Adulto JovemRESUMO
The influence of microstructural variations and chemical composition to the mechanical properties and apparent flaw sensitivity of dentin were evaluated. Rectangular beams (N = 80) of the deep and superficial coronal dentin were prepared from virgin 3rd molars; twenty beams of each region were nominally flaw free and the remainder possessed a single "surface flaw" via a Vickers indentation. Mechanical properties were estimated in four-point flexure and examined using Weibull statistics. Fourier Transform Infrared Microspectroscopy in Reflectance Mode (FTIR-RM) was used to quantify the relative mineral to collagen ratios. Results showed that the average flexural strength, and strain and energy to fracture of the deep dentin beams were significantly lower (P < 0.005) than for the superficial dentin. While the deep dentin exhibited the highest mineral/collagen ratio and lowest damage tolerance, there was no significant effect of the surface flaws. Weibull analyses suggest that deep dentin possesses a larger distribution of intrinsic flaw sizes that contributes to the location dependence in strength.
Assuntos
Dentina , Mecânica , Adolescente , Adulto , Humanos , Microscopia Eletrônica de Varredura , Adulto JovemRESUMO
PURPOSE: To demonstrate the robustness of the Featherstone pH cycling model when tested in three independent laboratories and to evaluate the use of "non-inferiority" testing at those laboratories. METHODS: The fundamental principles for the Featherstone laboratory pH cycling model to be an appropriate alternative to animal testing is that it must demonstrate equivalent accuracy to the "Gold Standard" (rat caries model) by: (1) providing a meaningful representation of the caries process; (2) demonstrating a proportionate response to fluoride dose (or concentration); (3) being able to show that clinically proven formulations perform similarly relative to the controls; and (4) differentiating products that have attenuated fluoride activity. RESULTS: This cross-validation study confirmed the ability of the three independent laboratories to discriminate between various concentrations of fluoride-containing dentifrice formulations, demonstrated that clinically proven formulas perform as expected and identified an attenuated fluoride formulation (NaF/CaCO3 dentifrice - 1100 ppm NaF) as inferior compared to the 1100 ppm F (NaF/silica) positive control.
Assuntos
Alternativas aos Testes com Animais , Cariostáticos/uso terapêutico , Cárie Dentária , Dentifrícios/química , Fluoretos/uso terapêutico , Animais , Bovinos , Cárie Dentária/fisiopatologia , Cárie Dentária/prevenção & controle , Esmalte Dentário , Dentifrícios/uso terapêutico , Relação Dose-Resposta a Droga , Humanos , Concentração de Íons de Hidrogênio , Estudos Prospectivos , Reprodutibilidade dos TestesRESUMO
Synthetic phospholipid vesicles (liposomes) containing the purified glycoprotein (G) of vesicular stomatitis virus (VSV) and solubilized membrane proteins from cells of the appropriate H-2 haplotype elicited H-2-restricted cytotoxic T lymphocytes (CTL) that lysed VSV-infected target cells. The CTL were elicited by intact liposomes, not by released components. Thus, when spleen cells from VSV-primed H-2d X H-2b hybrid mice were stimulated with liposomes having G protein + membrane proteins from cells with one of the parental H-2 haplotypes, the resulting CTL lysed only VSV-infected target cells with that parent's H-2 type. This result argues against the view that T cells in general recognize only processed antigenic fragments on macrophages. Moreover, liposomes were only effective when G protein and cell membrane proteins were included in the same vesicles. This result suggests that for effective interaction with CTL precursors the antigen (G protein) and products of the H-2 complex must be closer to each other than 600--1,000 angstrom, the diameter of the lipid vesicles used in this study.
Assuntos
Antígenos Virais/imunologia , Citotoxicidade Imunológica , Lipossomos/imunologia , Proteínas de Membrana/imunologia , Linfócitos T/imunologia , Animais , Cruzamentos Genéticos , Antígenos H-2/genética , Antígenos H-2/imunologia , Memória Imunológica , Camundongos , Camundongos Endogâmicos BALB C/genética , Baço/imunologia , Vírus da Estomatite Vesicular Indiana/imunologiaRESUMO
Significant histological overlap exists between fibro-osseous lesions and diagnosis is made on a clinicopathological basis. Ossifying fibroma is a benign fibro-osseous neoplasm of the jaw and craniofacial complex that has generated a degree of controversy regarding diagnosis and classification, especially with respect to the psammomatoid variant. Orbital lesions mainly arise from the paranasal sinuses affecting the medial or inferior orbital wall. Lateral orbital wall ossifying fibroma is, therefore, a rare condition with only a single previous case report. We present a second case of lateral orbital wall ossifying fibroma and a review of the associated literature.
Assuntos
Fibroma Ossificante/diagnóstico por imagem , Fibroma Ossificante/patologia , Neoplasias Orbitárias/diagnóstico por imagem , Neoplasias Orbitárias/patologia , Adulto , Biópsia por Agulha , Fibroma Ossificante/cirurgia , Seguimentos , Humanos , Imuno-Histoquímica , Masculino , Procedimentos Cirúrgicos Oftalmológicos/métodos , Neoplasias Orbitárias/cirurgia , Medição de Risco , Tomografia Computadorizada por Raios X/métodos , Resultado do TratamentoRESUMO
OBJECTIVES: The aim of this study was to compare measurements of angle of lateral opening (ALO) and version determined using a radioopaque cup position assessment device imaged with fluoroscopy to measurements obtained by CT and direct measurement in a cadaveric model. Our null hypothesis was that there would not be any difference in the angles measured by the techniques. METHODS: Six cadavers were implanted with BFX acetabular components. The CPAD was placed and images were obtained with fluoroscopy. Measurements were obtained from the radiopaque marker bars on the CPAD device, and version and ALO were calculated. The ALO and version were determined by CT and DM. Comparisons were made using a two-way analysis of variance and a generalized linear model procedure analysis. RESULTS: There were no significant differences between the measurements for ALO (p = 0.275) or version (p = 0.226). Correlation between methods was 0.948 and 0.951 for ALO and version, respectively. The mean difference (standard deviation [SD], and 95% confidence interval [CI]) for ALO were: CT versus CPAD 1.85 degrees (± 2.32 degrees [-2.99-3.31]), CT versus DM 1.96 degrees (± 1.99 degrees [-2.2-4.27]), CPAD versus DM1.74 degrees (±2.21 degrees [-1.13 and 5.24]). The mean difference (SD [CI]) for version was CT versus CPAD 2.86 degrees (±1.56 degrees [ -2.63-1.69]), CT versus DM 1.10 degrees (±1.42 degrees [-1.57-2.09]), CPAD versus DM 1.07 degrees (±0.76 degrees [0.13-2.09]). CLINICAL RELEVANCE: The results demonstrate that intraoperative imaging in cadaveric specimens with the CPAD is an accurate method to determine ALO and version of the acetabular component.
Assuntos
Acetábulo/cirurgia , Artroplastia de Quadril/veterinária , Cães , Fluoroscopia/veterinária , Prótese de Quadril/veterinária , Resinas Acrílicas , Animais , CadáverRESUMO
Functional integration of implanted biomaterials and bioengineered tissues in vivo requires effective and timely vascular ingrowth. While many vascularization strategies rely on delivery of angiogenic growth factors or endothelial cells to promote vascular ingrowth, the effect of physical and architectural features of biomaterials on the vascularization process is less well understood. Microchannels are a simple, accessible architectural feature frequently engineered into 3D biomaterials to promote mass transfer. In this study, the effect of microchannels on the integration and vascularization of 3D porous silk scaffolds was explored over a 14 week period. An array of 508 µm diameter microchannels spanning the length of critically sized, porous silk scaffolds significantly improved tissue ingrowth into the constructs. At week 6, all silk scaffolds (n = 8) with microchannels showed complete tissue infiltration throughout the construct, while only one of eight (12.5%) did so in the absence of microchannels. The presence of microchannels improved silk scaffold vascularization with significantly more vessels per unit area in the presence of microchannels. The vessel size distribution was similar in both scaffold types, but a shift in distribution toward smaller vessels was observed in the presence of microchannels. The blood vessels in silk scaffolds were perfused, functional and connected to the animal's cardiovascular system, as demonstrated by the presence of red blood cells in the vessel lumens, and effective delivery of a contrast agent the vessels inside the scaffold. This study demonstrates the utility of microchannels as a simple architectural feature that significantly improves vascularization and integration of implanted biomaterials.
Assuntos
Materiais Biocompatíveis , Seda , Animais , Sinais (Psicologia) , Células Endoteliais , Alicerces TeciduaisRESUMO
BACKGROUND: Saphenofemoral junction (SFJ) ligation has been a major component of surgical intervention for varicose veins; however, recurrence occurs in as many as 40%. Neovascularization with reconnection of the venous channels at the transected SFJ has been identified as the major cause of this recurrence. This randomized controlled study sought to evaluate mechanical suppression of neovascularization at the SFJ, with the use of a synthetic patch, to prevent recurrence after ligation surgery. METHODS AND RESULTS: A total of 389 limbs (from 292 patients) were randomized into either control (SFJ ligation surgery) or patch (SFJ ligation with polytetrafluoroethylene patch of the transected SFJ) groups. All patients underwent clinical assessment, duplex imaging, and air plethysmography studies preoperatively and at 1, 6, 12, and 36 months postoperatively. The patch consistently halved the recurrence rate to 3 years postoperatively in all clinical subgroups. In those patched SFJs that still developed recurrence, evidence of neovascularization circumventing the polytetrafluoroethylene patch was observed by both ultrasound and histology. CONCLUSIONS: This study demonstrates that use of a polytetrafluoroethylene patch is an effective mechanical suppressant of neovasculogenesis at the SFJ and can be safely used as a strategy to improve long-term outcome of varicose vein surgery.
Assuntos
Neovascularização Patológica/prevenção & controle , Politetrafluoretileno , Próteses e Implantes , Veia Safena/cirurgia , Varizes/cirurgia , Método Duplo-Cego , Segurança de Equipamentos , Feminino , Seguimentos , Humanos , Perna (Membro)/irrigação sanguínea , Ligadura , Masculino , Pessoa de Meia-Idade , Neovascularização Patológica/fisiopatologia , Neovascularização Patológica/cirurgia , Veia Safena/fisiopatologia , Prevenção Secundária , Tempo , Resultado do Tratamento , Varizes/fisiopatologia , Procedimentos Cirúrgicos Vasculares , Insuficiência Venosa/fisiopatologia , Insuficiência Venosa/cirurgiaRESUMO
Multiple death signals influence mitochondria during apoptosis, yet the critical initiating event for mitochondrial dysfunction in vivo has been unclear. tBID, the caspase-activated form of a "BH3-domain-only" BCL-2 family member, triggers the homooligomerization of "multidomain" conserved proapoptotic family members BAK or BAX, resulting in the release of cytochrome c from mitochondria. We find that cells lacking both Bax and Bak, but not cells lacking only one of these components, are completely resistant to tBID-induced cytochrome c release and apoptosis. Moreover, doubly deficient cells are resistant to multiple apoptotic stimuli that act through disruption of mitochondrial function: staurosporine, ultraviolet radiation, growth factor deprivation, etoposide, and the endoplasmic reticulum stress stimuli thapsigargin and tunicamycin. Thus, activation of a "multidomain" proapoptotic member, BAX or BAK, appears to be an essential gateway to mitochondrial dysfunction required for cell death in response to diverse stimuli.
Assuntos
Apoptose/fisiologia , Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2 , Proteínas Proto-Oncogênicas/metabolismo , Animais , Anticorpos , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3 , Biopolímeros , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Células Cultivadas , Grupo dos Citocromos c/metabolismo , Retículo Endoplasmático/metabolismo , Etoposídeo/farmacologia , Hepatócitos/citologia , Hepatócitos/metabolismo , Membranas Intracelulares/metabolismo , Proteínas de Membrana/genética , Camundongos , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas/genética , Transdução de Sinais , Estaurosporina/farmacologia , Transfecção , Raios Ultravioleta , Proteína Killer-Antagonista Homóloga a bcl-2 , Proteína X Associada a bcl-2 , Receptor fas/imunologia , Receptor fas/fisiologiaRESUMO
The state of nutritional health in the United States in the early part of the twentieth century was very different from today. Nutrient deficiencies and dental caries were prevalent health concerns for many Americans. In 1940, the US National Defense Advisory Commission asked the National Academy of Sciences for help in studying problems of nutrition in the United States. The outcome was issuance of the first RDAs. The goal of the RDAs was to recommend " allowances sufficiently liberal to be suitable for maintenance of good nutritional status." In the subsequent decades, a very different nutritional health challenge began to emerge for an increasing proportion of the population, that of overweight and obesity and risk of diet-related chronic disease. In part, as a response to this challenge, the RDA process was revised and the Dietary Reference Intakes (DRIs) were developed. The DRIs are a set of reference values that, when adhered to, predict a low probability of nutrient inadequacy or excessive intake. Recently, new DRI guidelines were proposed to define reference points for nutrient and food component intakes that influence risk of chronic disease. Developing DRIs for chronic disease endpoints presents unique challenges, notably, chronic diseases are multifactorial in nature and not directly nutrient-specific; the body of evidence supporting nutrients and other food substances as modifiers of risk of chronic disease is generally limited; and there is a lack of consistency in findings across study types. In addition, the latency of dietary exposures and chronic disease outcomes makes it difficult to demonstrate causality. Adapting the DRI model to meet the needs of the general population in the current context suggests a need to redefine the boundaries that describe the health of the population and to re-examine how indicators of chronic disease can be integrated effectively into the DRI process.