Ischemic preconditioning increases antioxidants in the brain and peripheral organs after cerebral ischemia

BACKGROUND AND PURPOSE: Low molecular weight antioxidants (LMWA), which reflect tissue reducing power, are among the endogenous mechanisms for neutralizing reactive oxygen species (ROS). Ischemic preconditioning (IPC) was associated with decreased oxidative stress. We examined the effect of focal ischemia on LMWA and on prostaglandin E(2) (PGE(2), a product of arachidonic acid oxidation) in the brain, heart, liver, and lungs of rats subjected to 90 min of ischemia and in IPC rats subjected to similar insult. METHODS: Transient right middle cerebral artery occlusion (MCAO) was performed for 90 min and at 0, 5, 30, 60, or 240 min of reperfusion, LMWA and PGE(2) were evaluated by cyclic voltametry (CV) and radioimmunoassay, respectively. IPC was induced by 2 min of MCAO, 24 h prior to the major ischemic episode. RESULTS: LMWA decreased at 5 min of reperfusion in the brain, heart, liver, and lung and rose 4 h later only in the brain. PGE(2) levels increased three to fivefold in all tissues examined. Surprisingly, in IPC rats a dramatic increase of LMWA occurred at 5 min of reperfusion in the brain and in the peripheral organs. Uric acid, but not ascorbic, is the major LMWA increased. CONCLUSIONS: We propose that after ischemia, ROS rapidly consume the antioxidants reserves in the brain and also in peripheral organs, suggesting that the whole body is under oxidative stress. Moreover, part of the neuroprotection afforded by IPC is mediated by the brain's ability to mobilize antioxidants, especially uric acid, that attenuate the massive ROS-mediated oxidative stress.     

A miniature and mobile intermittent pneumatic compression device for the prevention of deep-vein thrombosis after joint replacement

The WizAir-DVT is a miniature, lightweight (690 g), battery-operated and mobile intermittent pneumatic compression device (ICD), which enables continuous intraoperative use and immediate patient mobilization postoperatively. We compared its efficacy with a commonly used ICD, the Kendall SCD. Peak femoral vein flow velocity was measured in 20 apparently healthy volunteers at rest and with each device: we found no significant differences between them. A second prospective, randomized, clinical trial was used to compare the efficiency of the device in preventing deep venous thrombosis (DVT) after joint replacement in 50 patients (n=25/group). None developed DVT. Doppler ultrasonography revealed no significant differences. The WizAir-DVT antithrombotic compression device is as safe and effective as the Kendall SCD.     

Routine Cyclosporine concentration - C2 level Monitoring. Is it helpful during the early post Transplant Period?

Background

Pre dose or trough blood cyclosporine (CSA) concentration is routinely monitored and the result is used to alter patient''s drug dosing. Patients with identical pre dose blood CSA may have very different systemic exposure to the drug. Recently CSA 2 hour post dose level [C2] has been reported to correlate better with drug exposure. We undertook this study to evaluate the influence of trough and C2, CSA concentration monitoring on short-term renal allograft outcomes.

Methods

25 patients of renal transplant receiving a triple drug regimen of CSA micro emulsion (Panacea Biotec) 8mg/kg, azathioprine 1mg/kg and prednisolone 0.5mg/kg were analyzed prospectively for graft outcomes. CSA levels were monitored in whole blood by radioimmunoassay using monoclonal antibodies, at 72 hours after the transplant.

Results

The mean age of patients was 37.08 + 9.1 years. There were 20 males and 5 females. The mean age of donors was 40.2 + 8.2 years. There were 11 related donors with at least a haplomatch, 4 spousal and 10 unrelated donors with a nil antigen match. The mean pre dose CSA concentration was 289.22 + 171.9ng/ml; range (98.8 + 783.41ng/ml). The CSA concentration at 2 hours after the CSA administration was 838 + 310.87ng/ml (range, 169 + 1268ng/ml). 3 (12%) patients had acute rejection. In these patients the mean pre dose CSA concentration was 328.67ng/ml and the mean C2, CSA concentration was 1006.26ng/ml. CSA induced hemolytic uraemic syndrome was diagnosed in one patient. The trough and C2, CSA concentration levels were 174 and 870.83ng/ml respectively in this patient.

Conclusion

In our study CSA levels, trough and peak showed significant inter patient variability. The trough and C2 concentration levels did not correlate with the episodes of acute rejection. We conclude that in a triple drug regimen with fixed dosing schedules routine trough CSA level monitoring is not helpful in the acute post renal transplant period.Key Words: Cyclosporine levels, Cyclosporine trough levels, C2 levels     

Sonovue improves endocardial border detection and variability in assessing wall motion score and ejection fraction during stress echocardiography

Background Stress echocardiography is useful for assessing patients with coronary artery disease unable to undergo formal exercise testing. Considerable skill is required to avoid large intra- and inter-observer variability due to poor endocardial definition. Intravenous ultrasound contrast agents are now available which may improve this variability. Aim To study intravenous Sonovue in assessing wall motion score and ejection fraction (EF) during stress echocardiography. Methods Thirty-eight patients undergoing arbutamine stress echocardiography for known or suspected coronary artery disease were studied. Echocardiographic analysis of wall motion score index, endocardial border detection (EBD) and EF was performed at rest and at peak stress before and after intravenous injection of Sonovue, by experienced and inexperienced observers. Results All three observers noted an improvement in endocardial border definition following Sonovue (p=<0.001). At baseline, there was a significant difference in wall motion score index between experienced and inexperienced observers at rest (p=0.01) and at peak stress (p=0.001). Following Sonovue administration this was no longer significant (p=0.07, p=0.114). Intra-observer variability of end diastolic, end systolic volumes (ESV) and EF improved following contrast (p<0.05) at rest and during stress. Conclusion Sonovue significantly improved EBD and reduced intra-observer variability of EF at rest and during peak arbutamine infusion.     

Contrast sensitivity after wave front-guided LASIK

PURPOSE: To compare the effects on contrast sensitivity of wave front-guided (WFG) versus standard LASIK. DESIGN: Prospective, nonrandomized, comparative clinical study. PARTICIPANTS: Twenty-four eyes of 13 consecutive patients (mean age, 25.2+/-8.4 years; spherical equivalent, -0.5 to -4.25 diopters [D]) treated with WFG LASIK (WaveLight-Allegretto scanning-spot laser and wave front analyzer) and 22 eyes of 12 consecutive patients (mean age, 28.4+/-9.1 years; spherical equivalent, -0.75 to -4.5 D) treated with standard LASIK (WaveLight-Allegretto scanning-spot laser). METHODS: Best-corrected contrast sensitivity was measured before and 1 month after surgery in both the WFG LASIK group and the standard LASIK group. A sine-wave contrast sensitivity test (functional acuity contrast test) was used to measure contrast sensitivity at 5 spatial frequencies (1.5, 3, 6, 12, and 18 cycles/degree). We compared the LASIK-induced changes in contrast sensitivity in each groups at each spatial frequency. MAIN OUTCOME MEASURE: The effect on contrast sensitivity of WFG LASIK versus standard LASIK. RESULTS: Uncorrected visual acuity of 20/20 or better was achieved by 72% of eyes treated with WFG LASIK and by 70% of the eyes treated with standard LASIK. One month after LASIK, 88% of the contrast sensitivity measurements improved in the WFG LASIK group, whereas in the standard LASIK group, only 40% of the contrast sensitivity measurements improved. The contrast sensitivity improvement was significantly larger in the WFG LASIK group at all spatial frequencies (P<0.05). The WFG LASIK patients had a negative correlation between the changes in contrast sensitivity and the preoperative refractive error. CONCLUSIONS: The ability of WFG LASIK to correct optical aberrations results in significantly improved contrast sensitivity compared with standard LASIK 1 month after surgery.     

Trends in adolescent sexual risk behaviors

Many societies worldwide are faced with an increase in adolescent pregnancy, rape, sexual abuse and sexually transmitted disease due to different sexual behaviors and sometimes lack of responsible sexual behaviors. The World Health Organization and the Surgeon General of the United States Government have called for action to this serious public health issue. In this short communication data from the United States, Canada and Israel is presented with a call for a professional response to this public health challenge.     

Do physicians correctly estimate radiation risks from medical imaging?

Proper use of medical imaging tools requires knowledge of their associated radiation risks, as well as their possible benefits. The authors assessed physicians' knowledge of the radiation risks associated with bone scintigraphy (bone scan) during an annual meeting of the Israeli Orthopedic Society. The mortality risk of radiation-induced carcinoma from bone scan was identified correctly by less than 5% of respondents. The most frequent answer (38.4%) was the option that was least correct. Senior orthopedists estimated lower risks than did residents. Overall, respondents grossly underestimated the potential radiation risk from bone scan.     

Informed Consent

There have been significant changes in the doctor patient relationship with the impact of technology in day-to-day practice. More and more patients are aware of their rights and are keen to make free choice and decision on their treatment. This helps them to choose the treatment of their choice from the options available and to select a physician of their choice. Doctor's decisions are being questioned regarding their correctness and there is a need to educate the patient, on what one offers by way of treatment. In some procedures and types of treatment, patient needs to be educated and informed of the merits and demerits of the treatment available. This will help the patient to make appropriate choice and also to accept some adverse outcome of treatment. Towards this end, all countries are looking afresh at the necessity of Informed Consent. Methods adopted by some countries are highlighted to help our physicians practice them in an appropriate way. A lot of remedial work needs to be done to minimize future litigation, as many doctors misunderstand their legal obligations and haven't caught up with the change in judge's thinking.     

Significance of subcentimetre 18F-FDG PET/CT pulmonary abnormality in patients with known extrapulmonary malignancy

The significance of a subcentimetre ¹⁸F-FDG PET/CT pulmonary abnormality in a patient with known extrapulmonary primary malignancy can have a major impact on the clinical management of the patient. The clinician’s reliance on the semi-quantitative and qualitative PET/CT analysis of the abnormality has, at times, led to untoward diagnostic problems, given the limited spatial resolution of PET for a small volume lesion performed as part of the standard PET/CT study. This paper highlights a case each of an FDG-positive and an FDG-negative focal pulmonary abnormality in a combined PET/CT study of patients with known extrapulmonary malignancy. © 2010 Biomedical Imaging and Intervention Journal. All rights reserved.