Yoram Wollman

Effect of low-power laser irradiation on the mechanical properties of bone fracture healing in rats.

Low‐power laser irradiation (LPLI) has been found to have a positive effect on bone fracture healing in animal models, based on morphogenic, biochemical, roentgenographic, and electron microscopic measurements. We investigated the effect of LPLI on bone fracture healing in rats using biomechanical methods.

Anemia, chronic renal disease and congestive heart failure—the cardio renal anemia syndrome: the need for cooperation between cardiologists and nephrologists

Many patients with congestive heart failure (CHF) fail to respond to maximal CHF therapy and progress to end stage CHF with many hospitalizations, poor quality of life (QoL), progressive chronic kidney disease (CKD) which can lead to end stage kidney disease (ESKD), or die of cardiovascular complications within a short time. One factor that has generally been ignored in many of these people is the fact that they are often anemic. The anemia in CHF is due mainly to the frequently-associated CKD but also to the inhibitory effects of cytokines on erythropoietin production and on bone marrow activity, as well as to their interference with iron absorption from the gut and their inhibiting effect on the release of iron from iron stores. Anemia itself may further worsen cardiac and renal function and make the patients resistant to standard CHF therapy. Indeed anemia in CHF has been associated with increased severity of CHF, increased hospitalization, worse cardiac function and functional class, the need for higher doses of diuretics, progressive worsening of renal function and reduced QoL. In both controlled and uncontrolled studies of CHF, the correction of the anemia with erythropoietin (EPO) and oral or intravenous (IV) iron has been associated with improvement in many cardiac and renal parameters and an increased QoL. EPO itself may also play a direct role in improving the heart unrelated to the improvement of the anemia—by reducing apoptosis of cardiac and endothelial cells, increasing the number of endothelial progenitor cells, and improving endothelial cell function and neovascularization of the heart. Anemia may also play a role in the worsening of acute myocardial infarction and chronic coronary heart disease (CHD) and in the cardiovascular complications of renal transplantation. Anemia, CHF and CKD interact as a vicious circle so as to cause or worsen each other- the so-called cardio renal anemia syndrome. Only adequate treatment of all three conditions can prevent the CHF and CKD from progressing.

Nitric oxide in ischaemic acute renal failure of streptozotocin diabetic rats.

SummaryChanges in nitric oxide (NO) levels were determined in ischaemic acute renal failure in streptozotocin-induced diabetes mellitus rats. Two weeks after streptozotocin administration and immediately after right nephrectomy, the left renal artery was occluded for 60 min. Similar procedures were carried out in non-diabetic rats. The nitrite (NO2) + nitrate (NO3) levels were measured in plasma and urine. The effects of chronic oral supplementation with l-arginine and an NO synthase inhibitor (N-omega-nitro-l-arginine) were also studied in both diabetic and non-diabetic rats before and after renal artery clamping. The rats with diabetic acute renal failure had a much lower creatinine clearance (90±22 Μl · min−1 · 100 g body weight−1, p<0.005), and higher fractional excretion of sodium (FENa)% (10.90±4.2, p<0.001) and protein excretion (2078±69 Μg/ml creatinine clearance, p<0.001) compared with the respective values in the non-diabetic groups (163±30; 1.46±86; 453.3±31). The plasma and urine NO2 + NO3 levels were significantly higher in the untreated diabetic rats compared with the untreated normal rats before ischaemia (p<0.001). The ischaemic acute renal failure in non-diabetic rats increased the plasma and urinary NO2 + NO3 excretion after ischaemia. The urinary excretion of these metabolites decreased significantly and their plasma levels remained unchanged in the ischaemic diabetic rats. The l-arginine administration resulted in a small but significantly higher creatinine clearance after clamping in the non-diabetic rats. The NO synthase inhibitor caused deterioration in renal function in all ischaemic and non-ischaemic groups. In summary, the greater vulnerability to ischaemia of the diabetic kidney seems to be associated with both impaired response to and impaired production of NO.

rhEPO in patients with anemia and congestive heart failure

Many patients with congestive heart failure (CHF) fail to respond to maximal CHF therapy and progress to end stage CHF with many hospitalizations, very poor quality of life, end stage renal failure, or die of cardiovascular complications within a short time. One factor that has generally been ignored in many of these people is the fact that they are often anemic.The anemia is due mainly to renal failure but also to the inhibitory effects of cytokines on the bone marrow. Anemia itself may further worsen the cardiac function and make the patients resistant to standard CHF therapies. Indeed anemia has been associated with increased severity of CHF, increased hospitalization, worse cardiac function and functional class, higher doses of diuretics, worsening of renal function and reduced quality of life. In both controlled and uncontrolled studies the correction of the anemia with recombinant human erythropoietin (rhEPO) and oral or intravenous (IV) iron is associated with improvement in all these parameters. EPO itself may also play a direct role in improving the heart unrelated to the improvement of the anemia. Anemia may also play a role in the worsening of coronary heart disease even without CHF.