Possible cause for altered spatial cognition of prepubescent rats exposed to chronic radiofrequency electromagnetic radiation.

The effects of chronic and repeated radiofrequency electromagnetic radiation (RFEMR) exposure on spatial cognition and hippocampal architecture were investigated in prepubescent rats. Four weeks old male Wistar rats were exposed to RF-EMR (900 MHz; SAR-1.15 W/kg with peak power density of 146.60 µW/cm(2)) for 1 h/day, for 28 days. Followed by this, spatial cognition was evaluated by Morris water maze test. To evaluate the hippocampal morphology; H&E staining, cresyl violet staining, and Golgi-Cox staining were performed on hippocampal sections. CA3 pyramidal neuron morphology and surviving neuron count (in CA3 region) were studied using H&E and cresyl violet stained sections. Dendritic arborization pattern of CA3 pyramidal neuron was investigated by concentric circle method. Progressive learning abilities were found to be decreased in RF-EMR exposed rats. Memory retention test performed 24 h after the last training revealed minor spatial memory deficit in RF-EMR exposed group. However, RF-EMR exposed rats exhibited poor spatial memory retention when tested 48 h after the final trial. Hirano bodies and Granulovacuolar bodies were absent in the CA3 pyramidal neurons of different groups studied. Nevertheless, RF-EMR exposure affected the viable cell count in dorsal hippocampal CA3 region. RF-EMR exposure influenced dendritic arborization pattern of both apical and basal dendritic trees in RF-EMR exposed rats. Structural changes found in the hippocampus of RF-EMR exposed rats could be one of the possible reasons for altered cognition.

A novel method for blood volume estimation using trivalent chromium in rabbit models.

BACKGROUND: Blood volume measurement though important in management of critically ill-patients is not routinely estimated in clinical practice owing to labour intensive, intricate and time consuming nature of existing methods. AIMS: The aim was to compare blood volume estimations using trivalent chromium [(51)Cr(III)] and standard Evans blue dye (EBD) method in New Zealand white rabbit models and establish correction-factor (CF). MATERIALS AND METHODS: Blood volume estimation in 33 rabbits was carried out using EBD method and concentration determined using spectrophotometric assay followed by blood volume estimation using direct injection of (51)Cr(III). Twenty out of 33 rabbits were used to find CF by dividing blood volume estimation using EBD with blood volume estimation using (51)Cr(III). CF is validated in 13 rabbits by multiplying it with blood volume estimation values obtained using (51)Cr(III). RESULTS: The mean circulating blood volume of 33 rabbits using EBD was 142.02 ± 22.77 ml or 65.76 ± 9.31 ml/kg and using (51)Cr(III) was estimated to be 195.66 ± 47.30 ml or 89.81 ± 17.88 ml/kg. The CF was found to be 0.77. The mean blood volume of 13 rabbits measured using EBD was 139.54 ± 27.19 ml or 66.33 ± 8.26 ml/kg and using (51)Cr(III) with CF was 152.73 ± 46.25 ml or 71.87 ± 13.81 ml/kg (P = 0.11). CONCLUSIONS: The estimation of blood volume using (51)Cr(III) was comparable to standard EBD method using CF. With further research in this direction, we envisage human blood volume estimation using (51)Cr(III) to find its application in acute clinical settings.

Serial blood volume estimation in rabbits using trivalent chromium - An exploratory study.

Though often used in cardiac intensive monitoring set up, simultaneous evaluation of several variables like CVP, PCWP, SVV and hTEE for fluid volume resuscitation (especially when capillary permeability is major problem than cardiac performance) is a major challenge in many ICU setups. Therefore, repetitive determination of blood volume by trivalent chromium [51Cr (III)] as a direct single variable method may be a near ideal method during fluid volume resuscitation in cases where capillary permeability is a major problem (e.g. Burns). Hence, in the present article the repeatability and reliability of 51Cr (III) method in New Zealand white rabbits was explored. Mean blood volume values of initial measurement were 195.66 ± 47.30 ml or 89.81 ± 17.88 ml/kg body weight. Repeated mean blood volume values, measured after 1 h, was 181.98 ± 53.16 ml or 83.68 ± 22.09 ml/kg body weight. The average difference between the initial and repeated measurements was 10.93 ml (95% CI -3.33, 25.19 ml), which is not statistically significant (P = 0.128). The method using 51Cr (III) for repeat blood volume measurements after sixty minutes in rabbits is a reliable method. •Rapid•Repeatable•Reliable.