Time Related Fungal Contamination of Animal Cage Beddings

The purpose of the study was to measure the extent of fungal contamination in laboratory animal cage beddings  over time. The material was analysed for the content of fungal enzyme N-acetylhexosaminidase and  the fungal cell wall agent 1,3-ß-glucan at 0-7 days after use. In some cages the values were increased above  baseline already at 3 days and at 7 days practically all beddings showed a fungal contamination. It is suggested  that the fungal enzyme test can be used for bedding quality control purposes and to monitor fungal  contamination in animal cages to prevent pulmonary and other pathologies.

Behavioural Effects of the Shelter Design on Male Guinea Pigs

To improve the welfare of group-housed male guinea pigs during the acclimatization period, which is when  social groups are formed, different designs of shelters were tested, one shelter having one entrance to a single  compartment – a Box for group hiding – and the other having individual entrances to a compartment  in the cage – a Garage for single hiding. Both were studied to evaluate whether they had any affect on the  behavioral levels. Behavioural and weight data were collected during five of the seven days of the acclimatization  period. Data were tested against the Mann-Whitney U and Variance Analysis test. Results demonstrated  that males in cages with the garage spent more time inside the shelter (P =0.0004), while males in  cages with the box spent more time resting (P =0.000), feeding (P =0.0043) and drinking (P =0.0022) on  the open floor, and yet there was no difference in individual weight between treatments at the end of the  study. Males in cages with garage experienced a more rapid establishment of the social hierarchy (P =  0.0024) by being involved with a lower number of social interactions. The conclusion from the present  study is considered to show that males in cages with the garage were able to avoid unnecessarily high levels  of stress and aggression caused by territorial defence while the hierarchy was established.

Who is a compatible partner for a male mouse?

The complex issue of social housing of laboratory mice was addressed by studying the housing compatibility of male mice with castrated males, or with ovariectomized females, for a period of up to seven weeks. Sexually mature males were shown to be socially incompatible with castrated males of the same age but to be more compatible with same age or older ovariectomized females (results varied according to the mouse strains used). These ovariectomized females could also be repeatedly housed with different sets of younger male mice, even after being briefly separated and again re-paired. Our data suggest that ovariectomized females could be used to establish a long-term companion group fully compatible for male mice group housing

To Group or Not to Group? Good Practice for Housing Male Laboratory Mice

It is widely recommended to group-house male laboratory mice because they are ‘social animals’, but male mice do not naturally share territories and aggression can be a serious welfare problem. Even without aggression, not all animals within a group will be in a state of positive welfare. Rather, many male mice may be negatively affected by the stress of repeated social defeat and subordination, raising concerns about welfare and also research validity. However, individual housing may not be an appropriate solution, given the welfare implications associated with no social contact. An essential question is whether it is in the best welfare interests of male mice to be group- or singly housed. This review explores the likely impacts—positive and negative—of both housing conditions, presents results of a survey of current practice and awareness of mouse behavior, and includes recommendations for good practice and future research. We conclude that whether group- or single-housing is better (or less worse) in any situation is highly context-dependent according to several factors including strain, age, social position, life experiences, and housing and husbandry protocols. It is important to recognise this and evaluate what is preferable from animal welfare and ethical perspectives in each case

Fluid loading therapy to prevent spinal hypotension in women undergoing elective caesarean section Network meta-analysis, trial sequential analysis and meta-regression

BACKGROUND Fluid loading is one of the recognised measures to prevent hypotension due to spinal anaesthesia in women scheduled for a caesarean section. OBJECTIVE We aimed to evaluate the current evidence on fluid loading in the prevention of spinal anaesthesia-induced hypotension. DESIGN Systematic review and network meta-analysis with trial sequential analy

The effect of anaesthesia and adrenergic therapy on the distribution and elimination of a crystalloid solution studied by volume kinetic analysis

Intravenous fluid therapy is a mandatory treasure during anaesthesia and surgery. It is sometimes combined with adrenergic therapy to maintain haemodynamic stability. It is of great importance to know how the body handles the distribution of fluid in these circumstances in order to minimize the risk of fluid overload. The objective of this thesis was to examine intravenous fluid handling by studying changes in cardiovascular parameters and by using a volume kinetic method to analyze fluid volumes in the body. Methods: In Paper I we studied whether anaesthesia and surgery affect the sensitivity of the À-2 adrenergic receptor in vivo. 10 patients and 10 volunteers were given an intravenous infusion of epinephrine (50 Êg/kg/min). Both cardiovascular and biochemical changes were measured for which the ratios of the areas under the curve were calculated. In Paper II an animal model was used to evaluate how different adrenergic stimuli affect the distribution and elimination of crystalloid fluid bolus. The impact of three different drugs (dopamine 50 Êg/kg/min, isoprenaline 0.1 Êg/kg/min and phenylephrine 3 Êg/kg/min ) on the relationship between plasma dilution and haemodynamics was evaluated. The plasma dilution (an index of volume expansion) was studied using volume kinetic analysis. Paper III studied the initial effect of spinal and general anaesthesia on the distribution and elimination of crystalloid fluid loads. The volume kinetic model was fitted to data from a total of 20 patients who received 20 ml/kg BW of Ringer's acetate iv. The haemodynamic changes were also recorded. In Paper IV three different intravenous fluid regimens (a bolus of 5ml/kg BW of Ringer's acetate, 2 ml/kg BW of dextran I and a continuous infusion of Ringer's acetate 15 ml/kg BW over 40 min) were given during the induction of spinal anaesthesia to prevent arterial hypotension. A total of 75 patients were studied using haemodynamic measurements and volume kinetic analysis. The anaesthetic agent isoflurane has earlier been shown in air animal model to promote extravascular accumulation of crystalloid fluid and, in Paper V, thirty patients undergoing thyroid surgery were randomly anaesthetized with isoflurane or propofol (controls) respectively, to evaluate whether isoflurane also promotes extravascular accumulation in a human model given 25 ml/kg BW of Ringer Ls acetate. The volume kinetic model was again used to analyse the distribution and elimination of fluid. Results: The response to epinephrine (Paper I) measured as the AUC (area under the curve) of P-cAMP divided by the AUC for Pepinephrine, was more pronounced in the patient group than among the controls (p<0.02). This was reflected in greater hypokalaemic and hyperglycaemic responses (p<0.0004). All results indicate air increased adrenergic response during the first hour of abdominal surgery. All adrenergic drugs (Paper II) changed the baseline of the haemodynamic parameters. Alpha stimulus (phenylephrine) promoted renal excretion of fluid at the expense of fluid. distribution to the periphery (p<0.05 vs. controls) while beta stimulus (isoprenaline) had the opposite effect. Normal saline caused an increase in atrial, arterial pressures and in cardiac output. These increases showed a linear correlation with the plasma dilution, which was strong for both the phenylephrine and control groups. The volume kinetics in Paper III showed that the induction of anaesthesia resulted in similar changes in both groups. The elimination of fluid was significantly reduced (p<0.003) and the distribution of fluid from a central fluid space to a peripheral one was halved (p<0.01). Both types of anaesthesia decreased the mean arterial pressure significantly, and general anaesthesia to a higher degree than spinal anaesthesia (p<0.05). A computer simulation of the obtained kinetic data suggested that a small i.v. fluid load given immediately following the induction of spinal anaesthesia could be more effective in preventing hypotension and this was confirmed in 5 additional patients. In Paper IV there were no differences between the groups and the mean arterial pressure decreased by approximately 26%. The freight of the block was the only factor that correlated with the drop in blood pressure. Patient discomfort (nausea, swearing) was inure common in the dextran 1 and control groups. Volume kinetic analysis showed that the bolus regimens diluted plasma by 10% and, in the control group, by almost 20%. The dilution-time curve shows no apparent elimination during the bolus experiments, but the patients still had a diuresis. Fluid must therefore have been recruited front the periphery. Plasma dilution in Paper V increased to 30% during the infusion and then remained half as high throughout the experiment. Urinary excretion during the experiment amounted to only 11% of infused volume. The amount of water loss through extra vascular retention and evaporation was equal in both groups and amounted to 2.0-2.2 ml/min. Conclusion: Abdominal surgery under general anaesthesia for one hour does not cause desensitization of adrenergic receptors. Anaesthesia causes air accumulation of infused fluid in a central compartment by reducing the tendency for distribution to a peripheral compartment. Urinary excretion is markedly reduced. Both these facts contribute to a prolonged plasma dilution by crystalloid solutions. By adding an adrenergic drug, the distribution and elimination of such a fluid can be changed. Alpha stimuli cause a centralization of fluid. and promote diuresis, while beta stimuli have the opposite effect. lsoflurane does riot cause a greater extravascular accumulation of fluid. than propofol

Gestaltning : - organistens viktigaste instrument

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