RESUMEN
Cohesion is one of the most studied group phenomena and there is an agreement among scholars today that cohesion is a key contributor to team functioning and performance. A large body of research has shown that cohesion has several positive effects on psychological, social, and behavioral outcomes. Since research on cohesion has increased significantly in recent decades there is a need for an updated overview of research regarding antecedents and outcomes of cohesion in a military context. In this paper, a systematic literature review is conducted. The paper adheres to suggestions by scholars, relating the results in accordance with the dimensionality (i.e. social, task, or general) and organizational level of the construct (i.e. horizontal, vertical, or organizational) as well as focusing exclusively on studies with a longitudinal design. The paper highlights gaps in the literature and provides direction for future research.
RESUMEN
It is vital that cellular- and tissue-based products (CTPs) used for wound treatment do not provoke autoimmunity. In this study, the immunogenic response to extracts of 2 CTPs of piscine and porcine origin was assessed in the collagen-induced arthritis model. Male DBA/1J mice were divided into 4 groups, each composed of 7 to 9 animals. Each animal was injected with one of following to assess their immune responses: (1) bovine type II collagen (100 µg) in Freund's adjuvant, (2) extract of piscine skin (100 µg) in Freund's adjuvant, (3) extract of porcine urinary bladder matrix (100 µg) in Freund's adjuvant, or (4) Freund's adjuvant alone (control) at the beginning of the experiment and 3 weeks later. Clinical signs of arthritis were assessed from week 5 onwards, and anti-type II and anti-type I collagen antibody immunoglobulin G (IgG) serum levels were measured before injections and 8 weeks after exposure using enzyme-linked immunosorbent assays. Only the mice exposed to bovine type II collagen developed clinical arthritis accompanied by very high anti-type II collagen IgG serum levels. Anti-type II collagen IgG serum levels were also detected in the porcine group but were undetectable in the piscine skin and control groups after 8 weeks. There were no significant differences in anti-type I collagen IgG serum levels among the groups. The results showed that piscine skin did not provoke systemic autoimmunity against type II collagens in DBA/1J mice.
Asunto(s)
Dermis Acelular , Artritis Experimental/cirugía , Trasplante de Piel/métodos , Análisis de Varianza , Animales , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Explotaciones Pesqueras , Adyuvante de Freund/farmacología , Rechazo de Injerto , Supervivencia de Injerto , Inmunoglobulina G/inmunología , Masculino , Ratones , Ratones Endogámicos DBA , Distribución Aleatoria , Medición de Riesgo , Sensibilidad y Especificidad , Porcinos , Vejiga Urinaria/cirugía , Vejiga Urinaria/trasplanteRESUMEN
Surface proteins of viruses and bacteria used for cell attachment and invasion are candidates for degradation by proteases. Trypsin from Atlantic cod (Gadus morhua) was previously demonstrated to have efficacy against influenza viruses in vitro and on skin. In this paper, cod trypsin is shown to be 3-12 times more effective in degrading large native proteins than its mesophilic analogue, bovine trypsin. This is in agreement with previous findings where cod trypsin was found to be the most active among twelve different proteases in cleaving various cytokines and pathological proteins. Furthermore, our results show that cod trypsin has high efficacy against herpes simplex virus type 1 (HSV-1) and the respiratory syncytial virus (RSV) in vitro. The results on the antipathogenic properties of cod trypsin are important because rhinovirus, RSV, and influenza are the most predominant pathogenic viruses in upper respiratory tract infections. Results from a clinical study presented in this paper show that a specific formulation containing cod trypsin was preferred for wound healing over other methods used in the study. Apparently, the high digestive ability of the cold-adapted cod trypsin towards large native proteins plays a role in its efficacy against pathogens and its positive effects on wounds.
Asunto(s)
Antivirales/administración & dosificación , Gadus morhua , Enfermedades Respiratorias/tratamiento farmacológico , Tripsina/administración & dosificación , Animales , Investigación Biomédica , Bovinos , Herpesvirus Humano 1/efectos de los fármacos , Humanos , Orthomyxoviridae/efectos de los fármacos , Virus Sincitiales Respiratorios/efectos de los fármacos , Enfermedades Respiratorias/virologíaRESUMEN
Lipids such as fatty alcohols, free fatty acids and monoglycerides of fatty acids are known to be potent antimicrobial/microbicidal agents in vitro and to kill enveloped viruses, Gram-positive and Gram-negative bacteria and fungi on contact. For over half a century several studies have tried to answer the question of whether or not lipids play a role in the natural host defense against pathogens. A comprehensive review is given of these studies, particularly concerning infections in skin and in mucosal membranes of the respiratory tract, and of the role of lipids in the antimicrobial activity of breast milk. Based on studies of the microbicidal activities of lipids, both in vitro and in vivo, the possibility of using such lipids as active ingredients in prophylactic and therapeutic dosage forms is considered and examples are given of studies of such pharmaceutical dosage forms in experimental animal models and in clinical trials.
Asunto(s)
Antiinfecciosos , Lípidos/inmunología , Animales , Humanos , Inmunidad , Infecciones/inmunología , Lípidos/uso terapéuticoRESUMEN
Of 11 fatty acids and monoglycerides tested against Campylobacter jejuni, the 1-monoglyceride of capric acid (monocaprin) was the most active in killing the bacterium. Various monocaprin-in-water emulsions were prepared which were stable after storage at room temperature for many months and which retained their microbicidal activity. A procedure was developed to manufacture up to 500 ml of 200 mM preconcentrated emulsions of monocaprin in tap water. The concentrates were clear and remained stable for at least 12 months. They were active against C. jejuni upon 160- to 200-fold dilution in tap water and caused a >6- to 7-log(10) reduction in viable bacterial count in 1 min at room temperature. The addition of 0.8% Tween 40 to the concentrates as an emulsifying agent did not change the microbicidal activity. Emulsions of monocaprin killed a variety of Campylobacter isolates from humans and poultry and also killed strains of Campylobacter coli and Campylobacter lari, indicating a broad anticampylobacter activity. Emulsions of 1.25 mM monocaprin in citrate-lactate buffer at pH 4 to 5 caused a >6- to 7-log(10) reduction in viable bacterial counts of Salmonella spp. and Escherichia coli in 10 min. C. jejuni was also more susceptible to monocaprin emulsions at low pH. The addition of 5 and 10 mM monocaprin emulsions to Campylobacter-spiked chicken feed significantly reduced the bacterial contamination. These results are discussed in view of the possible utilization of monocaprin emulsions in controlling the spread of food-borne bacteria from poultry to humans.
Asunto(s)
Campylobacter jejuni/crecimiento & desarrollo , Emulsiones/farmacología , Escherichia coli/crecimiento & desarrollo , Glicéridos/farmacología , Salmonella/crecimiento & desarrollo , Alimentación Animal , Animales , Campylobacter jejuni/efectos de los fármacos , Pollos , Recuento de Colonia Microbiana , Escherichia coli/efectos de los fármacos , Contaminación de Alimentos/prevención & control , Humanos , Concentración de Iones de Hidrógeno , Pruebas de Sensibilidad Microbiana/métodos , Polisorbatos , Salmonella/clasificación , Salmonella/efectos de los fármacos , TensoactivosRESUMEN
Previous studies have shown that certain lipids and fatty alcohols have microbicidal activities against a number of pathogens. In this study, virucidal activities of fatty alcohols and lipids were tested against HSV types 1 and 2 at various concentrations, times, and pH levels. The aim was first, to determine which compounds are most virucidal against HSV and could possibly be used as active ingredients in topical drug formulations and second, to attempt to throw light on the mode of action of virucidal lipids. Good agreement was found between the activities for HSV-1 and HSV-2. The activity of a compound depends on the concentration and time of contact and most of the compounds are more active at pH 4.2 than at pH 7. This information may be helpful in the formulation of pharmaceutical dosage forms for treatment of herpes lesions in skin and mucosa. The difference between the polar groups of alcohols and fatty acids, i.e. hydroxyl group versus carboxyl group, and the corresponding difference in their hydrophile-lipophile balance (HLB) may explain their different virucidal activities against HSV. However, in most cases HLB numbers cannot explain the different virucidal activities of fatty alcohols and lipids, particularly not their increased activity at low pH. It is more likely that the acidic environment makes HSV more sensitive, possibly by ionic changes in the envelope proteins.
Asunto(s)
Antivirales/farmacología , Ácidos Grasos/farmacología , Alcoholes Grasos/farmacología , Glicéridos/farmacología , Herpesvirus Humano 1/efectos de los fármacos , Herpesvirus Humano 2/efectos de los fármacos , Animales , Chlorocebus aethiops , Dodecanol/farmacología , Relación Dosis-Respuesta a Droga , Concentración de Iones de Hidrógeno , Células VeroRESUMEN
A series of soft quaternary ammonium antimicrobial agents, which are analogues to currently used quaternary ammonium preservatives such as cetyl pyridinium chloride and benzalkonium chloride, were synthesized. These soft analogues consist of long alkyl chain connected to a polar headgroup via chemically labile spacer group. They are characterized by facile nonenzymatic and enzymatic degradation to form their original nontoxic building blocks. However, their chemical stability has to be adequate in order for them to have antimicrobial effects. Stability studies and antibacterial and antiviral activity measurements revealed relationship between activity, lipophilicity, and stability. Their minimum inhibitory concentration (MIC) was as low as 1 microg/mL, and their viral reduction was in some cases greater than 6.7 log. The structure-activity studies demonstrate that the bioactive compounds (i.e., MIC for Gram-positive bacteria of <10 microg/mL) have an alkyl chain length between 12 and 18 carbon atoms, with a polar headgroup preferably of a small quaternary ammonium group, and their acquired inactivation half-life must be greater than 3 h at 60 degrees C.