Hemodynamic effects of isometric exercise in hypertrophic cardiomyopathy: Comparison with normal subjects

BACKGROUND: We assessed the hemodynamic effects of isometric exercise by an ambulatory radionuclide monitoring device (VEST) that measured left ventricular function in patients who had hypertrophic cardiomyopathy (HCM), with and without significant left ventricular outflow-tract obstruction at rest, compared with control subjects. METHODS AND RESULTS: We studied 10 patients with obstructive HCM, 25 patients with nonobstructive HCM, and 11 control subjects. During VEST monitoring, all patients gripped a dynamometer at 75% of maximal strength for up to 5 minutes. End-diastolic, end-systolic, and stroke volumes; cardiac output; and systemic vascular resistance were expressed as a percentage of baseline. The mean exercise duration was similar among the 3 groups. During handgrip, heart rate, systolic blood pressure, and cardiac output increased significantly and similarly in the 3 groups. There was a significant difference in the lung activity between obstructive and nonobstructive HCM patients and control subjects (P <.001), with a fall in control subjects and no change in HCM patients, irrespective of obstruction. Control subjects showed a decrease in end-systolic volume (P =.02) and an increase in ejection fraction (P =.003) and stroke volume (P =.009), whereas these parameters did not change in HCM patients, irrespective of obstruction. Systemic vascular resistance increased in obstructive (P =.02) and nonobstructive (P <.01) HCM patients but did not change in control subjects. CONCLUSIONS: Isometric exercise causes an abnormal and similar adaptation to load changes in obstructive and nonobstructive HCM patients, as compared with control subjects.     

Therapeutic effectiveness and safety of outdated human red blood cells rejuvenated to improve oxygen transport function, frozen for about 1.5 years at 80 C, washed, and stored at 4 C for 24 hours prior to rapid infusion

After storage at 4 C for 20 to 28 days, red blood cells were biochemically modified to improve their oxygen transport function which had deteriorated during liquid storage. The solution used for rejuvenation contained pyruvate, inosine, glucose, phosphate, and adenine (PIGPA Solution B). The rejuvenated red blood cells were frozen with 40% W/V glycerol in a polyolefin plastic bag and were stored in the frozen state for about 1.5 years at −80 C. After thawing and washing the red blood cells were stored at 4 C in a sodium chloride- glucose-phosphate solution for 24 hours before transfusion. A pool of four to ten units was rapidly transfused to each of 14 elderly anemic recipients, 11 of whom had cardiopulmonary insufficiency. Recovery of the red blood cells after the freeze-thaw process was about 97 per cent, and after the freeze-thaw-wash process about 90 per cent. The 24− hour posttransfusion survival values were about 75 per cent, and the long-term survival values were about 85 days depending on the disease state of the recipient. The red blood cells had 1.5 times normal 2.3- DPG levels and a decreased affinity for oxygen at the time of transfusion and were able to delivery oxygen at high oxygen tension immediately after the rapid infusion of pools of from four to ten units through a 40-or 170-micron filter. Plasma hemoglobin levels were consistent with extravascular sequestration of nonviable red blood cells, and uric acid levels were not increased during the immediate 24− hour posttransfusion period.     

Giant cell tumour of the tendon sheath of the hand: A pictorial essay

Giant cell tumour of the tendon sheath is a soft tissue mass found occasionally in the hand. Its diagnosis can be readily made preoperatively if the characteristic MRI features are appreciated. This pictorial essay demonstrates and describes the imaging findings correlated with histopathological findings in a group of patients with proven giant cell tumour of the tendon sheath.     

Assessment of in vitro-generated platelet microparticles using a modified flow cytometric strategy.

Quantification of platelet microparticles (PMPs) may be a useful marker for the detection of in vivo platelet activation. Optimisation of flow cytometric methods for detection and quantification of PMPs has not been systemically evaluated. This study reports the optimisation of flow cytometric procedures for the detection of PMPs, the determination of limits of size detection using microbeads, and the characterisation of PMP generation by in vitro activation of platelets using collagen and adenosine 5' diphosphate (ADP). Fluorescent and plain microbeads proved useful for defining the limits of the flow cytometer in detecting PMPs. A systematic calibration of the forward scatter (FS) threshold parameter (size) of the flow cytometer using microbeads allowed for the detection of very small particles (down to 0.1 microm diameter). PMPs generated in vitro using ADP and collagen were reliably detected by flow cytometry using monoclonal antibodies (MAb) directed towards platelet surface membrane glycoproteins (Gp). The PMP events were detected in the FS low (i.e., small size events) and fluorescence (FL) high (i.e., platelet Gp MAb-labelled events) region. PMPs of different size profiles were observed for each of the agonists. Flow cytometry can be used as a tool in the assessment of PMPs. As detection of particles of this type is at the limit of resolution of flow cytometers, careful attention is required with the choice of platelet-specific MAb, isotype control, and optimisation of procedure setup and performance.