Acute effects of static stretching on isokinetic thigh strength on modern dancers.

AIM: The aim of this study was to examine the acute effects of static stretching in dominant leg flexor muscle groups on concentric isokinetic leg extension and flexion peak torque (PT), peak torque % body weight (PT%BW) and total work (TW) at 60, 180 and 300 °.s-1 in stretched and non-stretched limbs of modern dancers. METHODS: Twenty-six trained modern dancers volunteered in this study. On the first measurement, isokinetic tests were performed on dominant and non-dominant legs. On the second measurement, the dominant leg flexors were stretched using 3 unassisted and 1 assisted static stretching exercises (each 4x15 seconds; 10-second rest). After the stretching, isokinetic tests were repeated on both legs. RESULTS: The results indicated a positive increase in strength in the stretched (PT%BW, TW) and non-stretched (PT, PT%BW, TW) limbs in flexion at 180°s-1 (P<0.05). We observed a positive increase (P<0.05) in the stretched limb (180 and 300°.s-1, TW; 300°.s-1, PT%BW) in extension whereas an acute decrease (P<0.05) was observed in both legs (60˚.s-1, PT and PT%BW). CONCLUSION: Our findings indicated a possible positive effect of static stretching at high angular velocities on the strength production of isokinetic contraction in stretched and non-stretched muscles. However, due to its negative effect on the extensor muscle groups, we think using static stretching is required attention before maximal strength exercises.

Designing of MIP based QCM sensor having thymine recognition sites based on biomimicking DNA approach.

Quartz crystal microbalance (QCM) sensors coated with molecular imprinted polymers (MIP) have been developed for the determination of thymine. In this method, methacryloylamidoadenine (MA-Ade) have used as a new monomer and thymine template for inspiration of DNA nucleobases interaction. The thymine can be simultaneously hydrogen binding to MA-Ade and fit into the shape-selective cavities. Thus, the interaction between nucleobases has an effect on the binding ability of the QCM sensors. The binding affinity of the thymine imprinted sensors has investigated by using the Langmuir isotherm. The thymine imprinted QCM electrodes have shown homogeneous binding sites for thymine (K(a): 1.0 x 10(5)M(-1)) while heterogeneous binding sites for uracil. On the other hand, recognition selectivity of the QCM sensor based on thymine imprinted polymer toward to uracil, ssDNA and ssRNA has been reported in this work.

Biochemical and hemodynamic effects of ascorbic acid and alpha-tocopherol in coronary artery surgery.

This study was undertaken to evaluate the effects of alpha-tocopherol and ascorbic acid on markers of myocardial reperfusion injury and myocardial contractile function after coronary artery surgery. Forty-eight patients were divided into 4 groups; 300 mg/day alpha-tocopherol was given orally to the patients in group I for 14 days. In groups II and III, 4g of ascorbic acid was administered intravenously prior to induction and in the cardioplegic solution, respectively. Group IV was the control group. Blood samples were taken to determine the concentrations of creatine phosphokinase MB isoenzyme, malondialdehyde, uric acid, ascorbic acid and alpha-tocopherol in the perioperative period. Left ventricular functions were determined by means of MUGA scans and echocardiography preoperatively and on the 3rd and 7th days, postoperatively. The changes in serum creatine phosphokinase MB and malondialdehyde were significantly lower in study groups. when compared with the control group. We observed no significant changes in ventricular function, requirement for (+) inotropic agents and the incidence of ventricular arrhythmias among the groups, postoperatively. Biochemical findings are consistent with the free radical hypothesis. But we could not confirm these data with hemodynamic findings. This is probably due to the population of low-risk elective coronary surgery patients in this study.

Beneficial effects of dietary restriction on cerebral cortical synaptic terminals: preservation of glucose and glutamate transport and mitochondrial function after exposure to amyloid beta-peptide, iron, and 3-nitropropionic acid.

Recent studies have shown that rats and mice maintained on a dietary restriction (DR) regimen exhibit increased resistance of neurons to excitotoxic, oxidative, and metabolic insults in experimental models of Alzheimer's, Parkinson's, and Huntington's diseases and stroke. Because synaptic terminals are sites where the neurodegenerative process may begin in such neurodegenerative disorders, we determined the effects of DR on synaptic homeostasis and vulnerability to oxidative and metabolic insults. Basal levels of glucose uptake were similar in cerebral cortical synaptosomes from rats maintained on DR for 3 months compared with synaptosomes from rats fed ad libitum. Exposure of synaptosomes to oxidative insults (amyloid beta-peptide and Fe(2+)) and a metabolic insult (the mitochondrial toxin 3-nitropropionic acid) resulted in decreased levels of glucose uptake. Impairment of glucose uptake following oxidative and metabolic insults was significantly attenuated in synaptosomes from rats maintained on DR. DR was also effective in protecting synaptosomes against oxidative and metabolic impairment of glutamate uptake. Loss of mitochondrial function caused by oxidative and metabolic insults, as indicated by increased levels of reactive oxygen species and decreased transmembrane potential, was significantly attenuated in synaptosomes from rats maintained on DR. Levels of the stress proteins HSP-70 and GRP-78 were increased in synaptosomes from DR rats, consistent with previous data suggesting that the neuroprotective mechanism of DR involves a "preconditioning" effect. Collectively, our data provide the first evidence that DR can alter synaptic homeostasis in a manner that enhances the ability of synapses to withstand adversity.

Long-term effects of combined iliac dilatation and distal arterial surgery.

PURPOSE: When standard aortofemoral surgical procedure is combined with lower extremity vascular surgery, problems related with the hospital stay, morbidity, mortality and the cost of treatment will exist. The number of reports relating to combined iliac artery PTA and distal bypass surgery is limited. After the development of stenting procedures, the results of arterial system plasty have much more improved. This report reviews our preliminary experience with iliac artery angioplasty with distal bypass procedures. PATIENTS AND METHODS: A total of 41 patients have undergone combined iliac artery dilatation and distal arterial revascularization. Angioplastic procedures were performed in the angiography suite and distal surgery was carried out at the same day or the day after. Of all patients, 29 underwent percutaneous transluminal angioplasty (PTA) and 12 underwent combined PTA and stent placement. Ipsilateral femoropopliteal bypass was performed as a distal revascularization procedure in all patients. RESULTS: Mean systolic iliac artery pressure gradients improved from 34.7+/-8.6 mmHg to 3.9+/-3.2 mmHg after angioplastic procedures (P < 0.0001). Six patients needed reangioplasty because of restenosis in the follow-up period. Thrombectomy was performed on 1 patient in the early postoperative period and re-do femoropopliteal bypass was performed on two patients in the 2nd and 23rd months. Three minor wound infections were successfully treated with antibiotics and local care. Mean follow-up was 21.4 months (range 1-48 months). By life-table analyses, the overall 4-year cumulative primary patency of combined procedures was 78.1%. CONCLUSION: The results show that the combined procedure is a suitable method for the treatment of patients with multiple stenotic lesions at the iliac and distal arterial levels. We believe that the combined use of PTA and distal vascular surgery by an experienced surgical team will give beneficial results and a highly satisfactory outcome in this group of patients.

Evaluation of heparin-coated circuits with full heparin dose strategy.

Heparin-coated cardiopulmonary circuits (HCC) in combination with a reduced systemic heparin dose has been demonstrated to reduce postoperative hemorrhage after cardiac surgery. But, it has still been equivocal whether this effect was related to the improved bio-compatibility or to the reduced exposure of the circulating heparin. Sixty patients undergoing elective coronary artery bypass grafting were randomly allocated into two groups either to be operated by HCC (30 patients) or uncoated but otherwise identical circuits (NHCC). Full systemic heparinization was induced in both groups. Hemodynamic parameters, hematological and biocompatibility tests were monitored within 24 hours. Postoperative blood loss, requirements for transfusions, clinical performance were recorded. Arterial filters were examined electron microscopically. Platelet levels remained significantly higher in the HCC group starting at the tenth minute following the institution of cardiopulmonary bypass until postoperative 24 hours. Electron microscopy showed significantly more platelet adhesion and pseudopod formation in the NHCC group. The mean amount of shed pleural and mediastinal blood measured from the time of the sternal closure was significantly lower in the HCC group (316 +/- 30 cc for HCC and 550 +/- 35 cc for NHCC). Mean postoperative transfusion requirements were also lower in the HCC group (230 +/- 23 cc for HCC and 320 +/- 25 cc for NHCC). The use of HCC and full systemic heparinization did not change the inflammatory response or biocompatibility but demonstrated benefits in platelet preservation and postoperative bleeding.

The dose-dependent effects of L-carnitine in myocardial protection in normothermic ischemia.

L-Carnitine has been shown to improve the post-ischemic recovery of myocardial function and metabolic measurements that are reduced in the course of ischemia and reperfusion of the heart. In this study we used 40 male guinea-pigs in order to determine if the effect of L-carnitine which is used in the protection of the post-ischemic reperfused heart, is dose-dependent or not. All harvested hearts were perfused for 30 min on modified Langendorf apparatus with oxygenized Krebs-Henseleit solution. After this period, in (n = 10), 5 mmol and 10 mmol (group B, n = 10) of L-carnitine were added into a Krebs-Henseleit solution. After 20 min, perfusion was complete and the hearts were then exposed to normothermic ischemia for 20 minutes. Following the ischemia, hearts were reperfused with the same solutions for 30 min. In group C (n = 10), 10 mmol of L-carnitine was added into the solution at the post-ischemic reperfusion step. In the control group, the same procedures were performed without using L-carnitine. Matching was done according to the contractile force of the heart rate and the levels of malondialdehyde and adenosine deaminase. When 10 mmol L-carnitine was added into the perfusion solutions at the pre-ischemic period, the best results were obtained and myocardial damage was much less than the control group. The protective effects of L-carnitine in normothermic ischemia is dose-dependent and it must be given at the pre-ischemic period.

Psychiatric complications of cardiac surgery postoperative delirium syndrome.

Psychiatric disturbances due to cardiopulmonary bypass, especially postoperative delirium syndrome, are among the immediate complications of open-heart surgery. In a series of 32 male and 18 female patients the prevalence of such disorders was investigated and search was made for possible risk factors for their occurrence. Psychiatric, neurologic and electroencephalographic evaluation was made pre- and postoperatively, in addition to haemodynamic, echocardiographic, angiographic and regional cerebral blood flow studies. Nine of the 50 patients had significantly reduced perfusion of certain cerebral lobes in single photon emission computed tomography, and in six of them the psychiatric tests indicated postoperative delirium; three of these six also had moderate electroencephalographic changes. The cerebral hypoperfusion persisted on day 15 in four patients, while psychiatric tests were negative. The study showed possible risk factors to be patient age, long aortic cross-clamp time, high-dose inotropic support and excessive transfusion of blood or blood products.

Mitral and aortic valve replacement using fresh unstented pulmonary and aortic homografts.

The use of prosthetic valves carries a high incidence of complications including thromboembolism, hemolysis, infection, impaired hemodynamic function and mechanical failure. Unstented homograft valves provide a good quality of life, particularly in terms of a reasonable freedom from these complications. This paper presents the first simultaneous replacement of the mitral and aortic valves using fresh unstented pulmonary and aortic homografts collected from the same donor. We believe that this technique will be especially useful in developing countries facing financial difficulties and problems with patient education.

Effect of selenium on ischemic and reperfusion injury in isolated guinea pig lungs.

1. An experimental comparative study on isolated guinea pig lungs was carried out to determine the effect of selenium added to pulmoplegic solution on ischemic lung preservation. 2. Two different types of solutions (Eurocollins in control group and Eurocollins + selenium 10(-3) M in experimental group) were infused before 3 hr of normothermic ischemia. 3. Tissue malone dialdehyde (MDA) and tissue glutathione (GSH) levels were assessed before the ischemic period, after the ischemia and at the end of reperfusion. Electron microscopic changes were also studied at the end of reperfusion to compare the cellular injury between the groups. 4. Addition of selenium before the ischemic period relatively decreased tissue MDA levels after reperfusion but did not alter tissue GSH levels.

The role of selenium added to pulmonary preservation solutions in isolated guinea pig lungs.

An experimental comparative study on isolated guinea pig lungs has been undertaken to determine the probable beneficial effects of adding selenium to pulmonary preservation solutions in lung ischemia. The isolated lungs (n = 10 in each group) previously being perfused by oxygenated Krebs-Henseleit solution were put in normothermic ischemic conditions just after the infusion of 30 ml of pulmonary preservation solution (Euro-Collins in the control group, Euro-Collins plus selenium 10(-3) mol in the experiment group). After 3 hours of normothermic ischemia the lungs were reperfused with the same buffer for 20 minutes. Pulmonary artery pressures, tissue malondialdehyde levels, and adenosine deaminase levels of the perfusate were measured before and after the ischemic period and also at the end of reperfusion. An electron microscopic analysis was performed on the lung tissues at the end of the experimental procedure. According to our data, the addition of selenium to pulmonary preservation solution showed a significant protective effect regarding both ischemic and reperfusion injury.

The effect of selenium added cardioplegia in guinea pigs.

1. The aim of the study was to determine the effect of selenium added cardioplegic solutions on postischemic myocardial recovery. 2. The hearts were mounted on Langendorf perfusion apparatus and perfused with Krebs-Henseleit solution. The hearts were arrested by one of the following cardioplegic solutions; (a) K+ 20 mmol/l (control group); (b) K+ 20 mmol/l+selenium 10(-3) mol/l (experimental group). After 20 min of normothermic ischemia the hearts were reperfused by the same buffer. 3. Postischemic percentage changes of heart rate, contractile force and heart work were compared between the groups. 4. Addition of selenium to the cardioplegic solution significantly decreased the postischemic myocardial injury.

The effects of thyroid hormones on the heart following global ischemia. A clinical and experimental study.

Cardiopulmonary bypass is associated with a reduction in plasma thyroid hormone concentrations in patients undergoing cardiac surgery. However, studies of the effects of cardiopulmonary bypass on thyroid function are limited and many studies report conflicting data concerning only the period of cardiopulmonary bypass. In this study, we tried to clinically determine the effects of cardiopulmonary bypass on concentrations of thyroid hormones by comprehensive thyroid function tests in 10 patients before and after surgery, and observed the benefits of triiodothyronine supplementation after global ischemia on myocardial function experimentally in guinea pigs. In patients undergoing surgery, concentrations of total triiodothyronine and free triiodothyronine decreased progressively on the institution of cardiopulmonary bypass and remained below normal levels until 24 hours postoperatively. In the guinea pig hearts studied in a Langendorf perfusion apparatus, T3 supplementation enhanced percentage recovery of ventricular contractile force, heart work and heart rate with respect to other groups receiving no T3 supplementation or T3 supplementation without any ischemic interval.

Effect of right atrial appendicectomy on the release of atrial natriuretic peptide in humans.

The present study evaluated the effect of right atrial appendicectomy on the release of atrial natriuretic peptide (ANP) and subsequent changes in postoperative haemodynamics in 20 men undergoing coronary artery bypass graft surgery. The right atrial appendix was removed in ten patients and saved in ten. Serum ANP, sodium levels and urinary sodium excretion were measured before and on days 1, 7 and 30 after surgery. Haemodynamic parameters were monitored before surgery and on day 30. Serum ANP levels fell significantly in patients undergoing appendicectomy (P < 0.05); haemodynamic parameters were unchanged. Hence, appendicectomy reduced serum ANP levels in the short term, though these tended to rise again with time; cardiac function was not affected by lowered levels of serum ANP. Consequently, saving the appendix in right atrial appendicectomy improves natriuresis and may decrease diuretic requirement.

Effect of allopurinol on myocardial recovery during reperfusion.

A comparative study on isolated guinea pig hearts was carried out to determine the effect of allopurinol added to reperfusion solution on myocardial recovery after global ischaemia. After 20 min of normothermic ischaemia two groups of solutions (1-Krebs Solution 2-Krebs Solution + Allopurinol 1 mmol l-1) were used for reperfusion (10 animals in each group). Post-ischaemic myocardial functions (ventricular contractile force and heart work) and enzyme activities (CK-MB, LD) were compared with their preischemic values. Addition of allopurinol 1 mmol l-1 to reperfusion solution improved post-ischaemic myocardial functions and decreased myocardial injury.

Cardioplegia with adenosine and adenosine triphosphate in the isolated guinea pig heart.

In order to determine the effect of adenosine triphosphate (ATP) and adenosine in cardioplegic solutions, a comparative study has been undertaken in isolated guinea pig hearts using the Langendorff perfusion technique as a model of cardiopulmonary bypass. The hearts (n = 10 in each group) previously being perfused by Krebs-Henseleit solution, were arrested by one of the following cardioplegic solutions: 1) Potassium 20 mM/L (Plegisol), 2) Potassium 20 mM/L+ATP 10 mM/L, 3) Adenosine 10 mM/L, 4) Adenosine 10 mM/L+ATP 10 mM/L. After 45 min of hypothermic ischemia, postischemic recovery of heart rate, ventricular contractility, heart work and postischemic changes in tissue enzymes (LDH, SGOT, SGPT) were compared among the 4 different cardioplegic solutions. Arrest time and number of arrest beats were also recorded and compared among the groups. Although similar beneficial results on postischemic recovery were achieved with adenosine cardioplegia and with ATP supplemented potassium cardioplegia, ATP supplemented adenosine cardioplegia did not show any beneficial effects on postischemic recovery.

Effect of ATP and verapamil as cardioplegic additives in the isolated guinea pig heart.

1. A comparative study on isolated guinea pig hearts was carried out to determine the effects of ATP and verapamil as cardioplegic additives. 2. The hearts were arrested by one of the plegic solutions: I, potassium 20 mmol/l; II, potassium 20 mmol/l+verapamil 1.1 mumol/l; III, potassium 20 mmol/l+ATP 10 mmol/l. After 45 min of hypothermic ischemia, the hearts were reperfused by Krebs-Henseleit buffer. 3. Postischemic percentage change of myocardial functions (heart rate, contractility, heart work) and tissue enzymes (LDH, SGOT, SGPT) were compared between the groups. 4. Although a rapid cardiac arrest could be obtained by verapamil added cardioplegia. Postischemic myocardial recovery was much better with ATP added cardioplegic solutions.

Dipyridamole induced myocardial recovery after global ischemia.

1. An experimental comparative study on isolated guinea pig hearts was carried out to determine the effect of dipyridamole added to the reperfusion solution on myocardial recovery after global ischemia. 2. After 20 min of normothermic ischemia two groups of solutions: (1) Krebs solution; (2) Krebs + dipyridamole 20 micrograms/l (10 experiments in each group) were used for reperfusion. 3. Postischemic myocardial functions (heart rate, ventricular contractility, heart work) and tissue enzymes (CPK-MB, LDH) were compared with their preischemic values. 4. Addition of dipyridamole 20 micrograms/l to reperfusion solution improved postischemic myocardial functions and decreased myocardial injury.

Horseshoe lung with left lung hypoplasia.

Horseshoe lung is an uncommon congenital malformation in which the bases of the right and the left lungs are fused to each other by a narrow isthmus posterior to the cardiac apex. So far 22 cases have been described: most of these were associated with right lung hypoplasia and the scimitar syndrome. A horseshoe lung anomaly with left lung hypoplasia is described.