Prophylactic Cefazolin Dosing and Surgical Site Infections: Does the Dose Matter in Obese Patients?

Background Most surgical prophylaxis guidelines recommend a 3-g cefazolin intravenous dose in patients weighing ≥ 120 kg. However, this recommendation is primarily based on pharmacokinetic studies rather than robust clinical evidence. This study aimed to compare the prevalence of surgical site infections (SSIs) in obese and non-obese patients (body mass index ≥ 30 kg/m2 and < 30 kg/m2), and those weighing ≥ 120 kg and < 120 kg, who received 2- g cefazolin preoperatively. Methods A retrospective case-control study was conducted in adult elective surgical patients. Patients receiving 2- g cefazolin were grouped as obese and non-obese, and by weight (≥ 120 kg or < 120 kg). The 90-day prevalence of SSI and potential contributing factors were investigated. Results We identified 152 obese (median 134 kg) and 152 non-obese control (median 73 kg) patients. Baseline characteristics were similar between groups, except for an increased prevalence in the obese group of diabetes (35.5% vs 13.2%; p < 0.001) and an American Society of Anaesthesiologists Score of 3 (61.8% vs 17.1%; p < 0.001). While not statistically significant, the prevalence of SSI in the obese group was almost double that in the non-obese group (8.6% vs 4.6%; p = 0.25) and in patients weighing ≥ 120 kg (n = 102) compared to those weighing < 120 kg (n = 202) (9.8% vs 5.0%; p = 0.17). Conclusion The prevalence of SSI was not significantly increased in obese patients, or those weighing ≥ 120 kg, who received cefazolin 2- g prophylactically; however, trends toward an increase were evident. Large-scale randomised trials are needed to examine whether a 2-g or 3-g cefazolin is adequate to prevent SSI in obese (and ≥ 120 kg) individuals

The impact of increased flooding occurrence on the mobility of potentially toxic elements in floodplain soil – a review

The frequency and duration of flooding events are increasing due to land-use changes increasing run-off of precipitation, and climate change causing more intense rainfall events. Floodplain soils situated downstream of urban or industrial catchments, which were traditionally considered a sink of potentially toxic elements (PTEs) arriving from the river reach, may now become a source of legacy pollution to the surrounding environment if PTEs are mobilised by unprecedented flooding events. When a soil floods, the mobility of PTEs can increase or decrease due to the net effect of five key processes; (i) the soil redox potential decreases which can directly alter the speciation, and hence mobility, of redox sensitive PTEs (e.g. Cr, As), (ii) pH increases which usually decreases the mobility of metal cations (e.g. Cd2+, Cu2+, Ni2+, Pb2+, Zn2+), (iii) dissolved organic matter (DOM) increases, which chelates and mobilises PTEs, (iv) Fe and Mn hydroxides undergo reductive dissolution, releasing adsorbed and co-precipitated PTEs, and (v) sulphate is reduced and PTEs are immobilised due to precipitation of metal sulphides. These factors may be independent mechanisms, but they interact with one another to affect the mobility of PTEs, meaning the effect of flooding on PTE mobility is not easy to predict. Many of the processes involved in mobilising PTEs are microbially mediated, temperature dependent and the kinetics are poorly understood. Soil mineralogy and texture are properties that change spatially and will affect how the mobility of PTEs in a specific soil may be impacted by flooding. As a result, knowledge based on one river catchment may not be particularly useful for predicting the impacts of flooding at another site. This review provides a critical discussion of the mechanisms controlling the mobility of PTEs in floodplain soils. It summarises current understanding, identifies limitations to existing knowledge, and highlights requirements for further research

Kärlek kommer! : En undersökning av etnicitetsrepresentation i en svensk reklamföljetong

Den här uppsatsen undersöker om karaktärerna i Comviqs populära reklamföljetong om kioskägaren Karim utsatts för någon form av reduktion och/eller stereotypisering baserad på etnicitet. Med en teoretisk ansats från verk av erkända forskare som studerat stereotyper, representation, svensk film och media bland annat, har det empiriska materialet, reklamföljetongen, analyserats enligt den semiotiska traditionen. Materialet tolkas och diskuterats med stöd i den teoretiska ansatsen, med syfte att avslöja eventuell negativ missrepresentation av etniciteter. Uppsatsen avser också att diskutera vad framställningen av karaktärerna skulle kunna ha för effekt på diverse etniska grupper i samhället. Resultatet av undersökningen landade i att en viss grad av stereotyp framställning försiggår, men att det slutgiltiga budskapet som förs fram har en positiv och antirasistisk klang

Negative fungal chemotropism to toxic metals

Hyphal growth responses of Geotrichum candidum, Gliocladium roseum, Humicola grisea and Trichoderma viride to Cu and Cd were studied using a simple tessellated agar tile system. Negative chemotropic behaviour of hyphae, which included curling and growth away from metal-containing domains, occurred in all species and with both metals. Both toxic metal and sucrose concentrations in the medium modulated the magnitude of the negative chemotropic effects observed. In general, greater concentrations of metals led to a higher level of negative chemotropism in response to Cu and Cd, which could be reduced with increasing concentrations of sucrose in the medium. This suggests that resource availability affects the ability of these fungi to grow into metal-laden domains. ß 2000 Federation of Europea

Nutritional influence on fungal colony growth and biomass distribution in response to toxic metals

This work examines nutritional influence on fungal colony growth and biomass distribution in response to toxic metals. In low-substrate solid medium, 0.1 mM Cd, Cu and Zn caused a decrease in radial expansion of both Trichoderma viride and Rhizopus arrhizus. However, as the amount of available carbon source (glucose) increased, the apparent toxicity of the metals decreased. These metals also affected the overall length of the fungal mycelium and branching patterns. In low-nutrient conditions, T. viride showed a decrease in overall mycelial length and number of branches in response to Cu, resulting in an extremely sparsely branched colony. Conversely, although Cd also reduced overall mycelial length to about one-third of the control length, the number of branches decreased only slightly which resulted in a highly branched colony with many aberrant features. Cu and Cd induced similar morphological changes in R. arrhizus. A large-scale mycelial-mapping technique showed that disruption of normal growth by Cu and Cd resulted in altered biomass distribution within the colony. When grown on metal-free low-substrate medium, T. viride showed an even distribution of biomass within the colony with some allocation to the periphery. However, Cu caused most of the biomass to be allocated to the colony periphery, while in the presence of Cd, most biomass was located at the interior of the colony. These results imply that such alterations of growth and resource allocation by Cu and Cd may influence success in locating nutrients as well as survival, and that these metals have individual and specific effects on the growing fungus