Evasion of the toxic effects of oxygen

Oxygen is an efficient terminal electron acceptor in respiratory pathways. During aerobic respiration the electron transport chain generates free radical oxygen species as a result of electron leakage; this generation of toxic species is proportional to the oxygen tension (51). In addition, toxic oxygen species (TOS) may be formed exogenously, for example, by chemical processes or through radiation. TOS also result from the oxidative burst of polymorphonuclear leukocytes (PMN). Infection with Helicobacter pylori induces an inflammatory response (gastritis), which leads to an increase in the level of TOS in the gastric mucosa and the gastric juice (4, 24–26, 59). This increase in the level of toxic metabolites is probably the result of the generation of the superoxide anion (O2·− ), a reactive TOS, formed as part of the oxidative burst of PMN and enzymic activities of gastric epithelial cells. There is evidence that H. pylori infection leads to increased production of O2·− via NADPH oxidase in gastric cells, stimulated by lipopolysaccharide as well as xanthine oxidase, another mechanism for the generation of oxygen-derived free radicals (8, 80). In response to increased superoxide anion production in gastric tissue, changes have been detected in the level of expression of human superoxide dismutase (SOD) (12). Human gastric SOD exists as a cytoplasmic copper-zinc-superoxide dismutase (Cu, Zn-SOD) found in gland cells of the gastric body and antral mucosa, and as a manganese-superoxide dismutase (Mn-SOD) within mitochondria (63). An increase in the amount and activity of Mn-SOD has been observed in response to H. pylori infection and gastritis, whereas the amount and activity of the Cu, Zn-SOD remained constant or decreased slightly (39). It has been suggested that the induction of Mn-SOD is in response to increased cytokine production within the inflamed gastric mucosa (39). This situation is reversed following successful treatment of the infection (38). The data suggest that within the gastric environment H. pylori may be exposed to increased levels of TOS. In such an environment it is important for bacterial survival that the impact of such TOS be neutralized

Genomics and drug discovery

Genomics represents a new tool in drug discovery. Microbial genomics have been at the forefront of a new era of whole cell molecular biology because genomic data provides a quantum leap in available genetic data. But while the tool is valuable and important, it is not the complete answer

Lateral stress evolution in chromium sulfide cermets with varying excess chromium

The shock response of chromium sulfide-chromium, a cermet of potential interest as a matrix material for ballistic applications, has been investigated at two molar ratios. Using a combustion synthesis technique allowed for control of the molar ratio of the material, which was investigated under near-stoichiometric (cermet) and excess chromium (interpenetrating composite) conditions, representing chromium:sulfur molar ratios of 1.15:1 and 4:1, respectively. The compacts were investigated via the plate-impact technique, which allowed the material to be loaded under a onedimensional state of strain. Embedded manganin stress gauges were employed to monitor the temporal evolution of longitudinal and lateral components of stress in both materials. Comparison of these two components has allowed assessment of the variation of material shear strength both with impact pressure/strain-rate and time for the two molar ratio conditions. The two materials exhibited identical material strength despite variations in their excess chromium content

Fomentar el desarrollo sustentable en las zonas poco favorecidas:

Tabla de matieras: Tecnologias para las tierras altas del este de Africa;tecnologias para las zonas tropicales de los Andes; Tecnologias para las tierras altas del sudeste de Asia; Utilidades de la inversion publica: datos de la India y China; Estrategias de desarrollo para las zonas semiaridas del sur de Asia; Estratagias de desarollo para las tierras altas del este de Africa; Estratagias de desarrollo para el oeste de Africa; La funcion de la ciencia agricola.resource management, Sustainability, Rural development projects, Developing countries, Agriculture, india,

Agricultural growth linkages in Sub-Saharan Africa:

How much extra net income growth can be had in rural areas of Africa by increasing the spending power of local households? The answer depends on how rural households spend increments to income, whether the items desired can be imported to the local area in response to increased demand, and, if not, whether increased demand will lead to new local production or simply to price rises. For every dollar in new farm income earned, at least one additional dollar could be realized from growth multipliers, according to Agricultural Growth Linkages in Sub-Saharan Africa.Income Rural areas Africa., Agricultural development Africa., Agricultural policy Economic aspects., Households Zimbabwe., Social accounting., Africa sub-Saharan,

Understanding the barriers to accessing symptom-specific cognitive behavior therapy (CBT) for distressing voices: reflecting on and extending the lessons learnt from the CBT for psychosis literature

The experience of hearing voices ('auditory hallucinations') can cause significant distress and disruption to quality of life for people with a psychosis diagnosis. Psychological therapy in the form of Cognitive Behavior Therapy for psychosis is recommended for the treatment of positive symptoms, including distressing voices, but is rarely available to patients in the UK. Cognitive Behavior Therapy for psychosis has recently evolved with the development of symptom-specific therapies that focus upon only one symptom of psychosis at a time. Preliminary findings from randomized controlled trials suggest that these symptom-specific therapies can be more effective for distressing voices than the use of broad CBT protocols, and have the potential to target voices trans-diagnostically. Whilst this literature is evolving, consideration must be given to the potential for a symptom-specific approach to overcome some of the barriers to delivery of evidence-based psychological therapies within clinical services. These barriers are discussed in relation to the UK mental health services, and we offer suggestions for future research to enhance our understanding of these barriers

Understanding clinician attitudes towards implementation of guided self-help cognitive behaviour therapy for those who hear distressing voices: using factor analysis to test normalisation process theory

Background The Normalisation Process Theory (NPT) has been used to understand the implementation of physical health care interventions. The current study aims to apply the NPT model to a secondary mental health context, and test the model using exploratory factor analysis. This study will consider the implementation of a brief cognitive behaviour therapy for psychosis (CBTp) intervention. Methods Mental health clinicians were asked to complete a NPT-based questionnaire on the implementation of a brief CBTp intervention. All clinicians had experience of either working with the target client group or were able to deliver psychological therapies. In total, 201 clinicians completed the questionnaire. Results The results of the exploratory factor analysis found partial support for the NPT model, as three of the NPT factors were extracted: (1) coherence, (2) cognitive participation, and (3) reflexive monitoring. We did not find support for the fourth NPT factor (collective action). All scales showed strong internal consistency. Secondary analysis of these factors showed clinicians to generally support the implementation of the brief CBTp intervention. Conclusions This study provides strong evidence for the validity of the three NPT factors extracted. Further research is needed to determine whether participants’ level of seniority moderates factor extraction, whether this factor structure can be generalised to other healthcare settings, and whether pre-implementation attitudes predict actual implementation outcomes