The effects of spinal, inhalation, and total intravenous anesthetic techniques on ischemia-reperfusion injury in arthroscopic knee surgery.

PURPOSE: To compare the effects of different anesthesia techniques on tourniquet-related ischemia-reperfusion by measuring the levels of malondialdehyde (MDA), ischemia-modified albumin (IMA) and neuromuscular side effects. METHODS: Sixty ASAI-II patients undergoing arthroscopic knee surgery were randomised to three groups. In Group S, intrathecal anesthesia was administered using levobupivacaine. Anesthesia was induced and maintained with sevoflurane in Group I and TIVA with propofol in Group T. Blood samples were obtained before the induction of anesthesia (t1), 30 min after tourniquet inflation (t2), immediately before (t3), and 5 min (t4), 15 min (t5), 30 min (t 6), 1 h (t7), 2 h (t8), and 6 h (t9) after tourniquet release. RESULTS: MDA and IMA levels increased significantly compared with baseline values in Group S at t2-t 9 and t2-t7. MDA levels in Group T and Group I were significantly lower than those in Group S at t2-t8 and t2-t9. IMA levels in Group T were significantly lower than those in Group S at t2-t7. Postoperatively, a temporary 1/5 loss of strength in dorsiflexion of the ankle was observed in 3 patients in Group S and 1 in Group I. CONCLUSIONS: TIVA with propofol can make a positive contribution in tourniquet-related ischemia-reperfusion.

Signal peptide-CUB-EGF domain-containing protein 1 (SCUBE1) level in hemodialysis patients and parameters affecting that level.

BACKGROUND: Signal peptide-CUB (complement C1r/C1s, Uegf, and Bmp1)-EGF (epidermal growth factor)-domain-containing protein 1 (SCUBE1) is a cell surface protein belonging to the SCUBE gene family. SCUBE1 has been shown to rise in parallel with platelet activation in acute ischemic events. However, there are no studies showing levels in the hemodialysis patient group, in which there is known to be an increase in platelet function impairment and activation. The purpose of this study was to investigate SCUBE1 levels in a hemodialysis patient group and the factors affecting those levels. MATERIALS AND METHODS: One hundred three hemodialysis patients and 21 age-matched healthy controls were included. SCUBE1 and sCD40L levels were investigated from blood specimens collected on pre- and post-hemodialysis sessions. We investigated the correlation between SCUBE1 levels and sCD40L, patients' demographic data, parameters with hemodialysis treatment and routine biochemical tests. RESULT: SCUBE1 levels were significantly higher in the hemodialysis patient group compared with the controls (p=0.000). There was a significant rise in SCUBE1 levels in the post-hemodialysis session (p=0.000). We determined a positive correlation between SCUBE1 and sCD40L (p=0.016, r=0.215). Gender, blood pressure, BUN, creatinine, hematocrit and high-sensitivity C-reactive protein (hsCRP) levels, hemodialysis membrane surface area, amount of ultrafiltration, blood flow rate, dialysis flow rate and carnitine use significantly affected SCUBE1 levels. CONCLUSION: We have shown, for the first time in the literature, that SCUBE1 level, a potential acute ischemia marker, is elevated in hemodialysis patients with no clinical ischemic event, and that various factors affect this elevation.

Relation between serum ischemia-modified albumin levels and rectus abdominis muscle flap viability.

Ischemia is a major cause of flap failure in reconstructive surgery. To detect circulatory compromise, many flap monitoring methods are used; however, there is no any optimal standard method. Ischemia-modified albumin (IMA) is an ischemia marker, which has recently been investigated in many studies and largely validated for early detection of ischemia. In this study, we investigated possible relationship between muscle flap viability and serum IMA levels in experimental flap model. The rectus abdominis muscle flap model was used in 18 New Zealand white rabbits. The study was planned using 3 groups. In group 1, the rectus abdominis muscle flap was harvested as a superior pedicle-based flap in which the inferior pedicle was sacrificed. In group 2, the flap was harvested by severing the superior pedicle. Both pedicles were harvested in group 3. Serum IMA levels were measured before the procedure and 1 hour, 6 hours, and 7 days postoperatively and then compared. In group 3, in which the ischemia was evident, and in group 1, IMA levels were significantly high 1 hour postoperatively (P < 0.05). There was no other significant difference in any of the other studied parameters between the groups. In conclusion, IMA can be used as a biochemical parameter for monitoring muscle flap viability.

Diagnostic value of pleural effusion ischaemia-modified albumin in patients with cardiac failure.

BACKGROUND: Ischaemia-modified albumin (IMA) is a relatively new marker of ischaemia. IMA has not been studied previously in pleural effusions due to congestive heart failure (CHF). The aim of our study was to assess the diagnostic value of IMA in the pleural fluid (PF) and serum for the identification of pleural effusion due to CHF. METHODS: The concentrations of pleural fluid and serum IMA were measured in a total of 40 patients: 10 with CHF and 30 with non-cardiac failure (10 with acute pulmonary embolism, 10 with parapneumonic effusion and 10 with malignancy). The area under the curve (AUC) quantified the overall diagnostic accuracy of the tests. RESULTS: The study demonstrated that IMA concentration was higher in both pleural fluid and serum of CHF patients compared with non-cardiac patients. PF and serum IMA demonstrated AUCs of 0.927 (95% CI: 0.844-1.00, P < 0.001), and 0.792 (95% CI: 0.653-0.930, P = 0.006), respectively, for diagnosing effusions due to CHF. The sensitivity and specificity of PF-IMA for CHF at the cut-off concentration of ≥1.0 absorbance units was 90% and 80%, respectively. Its negative predictive value (NPV) was quite high (96%). Positive correlation was found between PF-IMA concentrations and serum-IMA (r = 0.540, P < 0.001). CONCLUSIONS: Measuring IMA concentrations in serum and pleural fluid may be helpful in distinguishing pleural effusion due to a cardiac or non-cardiac aetiology.

Treatment related changes in antifibrinolytic activity in patients with polycythemia vera.

Polycythemia vera (PV) is a clonal myeloproliferative disorder characterized by predominantly excessive erythrocyte production. During the course of the disease, bleeding or thrombosis may be observed. In PV patients, the influence of antifibrinolytic activities on development of thrombohemorrhagic complications remains to be elucidated. In the present study, alterations in antifibrinolytic activity of PV patients and the effects of treatments on these alterations were investigated. Newly diagnosed and therapy-naive 22 PV patients were included. Thrombomodulin (TM), plasmin-alpha 2-antiplasmin complex (PAP), plasminogen activator inhibitor-1 (PAI-1) and thrombin activable fibrinolysis inhibitor antigen (TAFIa) levels were measured in all individuals and after phlebotomy and 5-hydroxyurea (5-HU) therapy in PV patients. TM, PAP, PAI-1 and TAFIa values of the patient group were higher than those of the controls. After phlebotomy, no changes were detected in TM, PAI-1 and TAFIa values, but PAP values decreased. On the contrary, 5-HU treatment resulted in a marked decrease in TM, PAI-1, PAP and TAFIa levels. These findings suggested that the changes in antifibrinolytic activity and endothelial dysfunction might be contributed to formation of intravascular thrombosis in PV patients, even though not clinically overt. 5-HU in addition to phlebotomy affects antifibrinolytic activity and may have an influence on diminishing predisposition of thrombosis.

Can ischemia-modified albumin be a valuable indicator of tissue ischemia in polycythemia vera?

The red cell expansion in polycythemia vera (PV) causes hyperviscosity affecting blood flow, which plays a major role in the pathogenesis of both microcirculatory disturbances and ultimately thromboses. Ischemia-modified albumin (IMA) is produced during an ischemic states and is present in blood in early and easily detectable levels. This study investigated whether IMA is a useful adjunct in the determination of ischemia in patients with PV, prior to them exhibiting clinical evidence of thrombotic complications. Blood IMA levels were determined in 20 PV patients and in 20 healthy individuals using a method described by Bar-Or. Mean IMA levels in the PV group were significantly higher than those of the control group (P<0.05). At the optimum cutoff point (0.193 absorbance units), the sensitivity and specificity of IMA were 80 and 100% to ischemia, respectively. In conclusion, IMA may be a valuable biochemical marker in predicting tissue ischemia in PV before the signs of vascular disturbances occur.

Occult inflammation and/or ischemia may be responsible for the false positivity of biochemical Down syndrome screening test.

OBJECTIVE: To determine the possible underlying cause of a false-positive first or second trimester biochemical Down syndrome screening test result by means of second trimester amniotic fluid cytokine level analysis. METHODS: A total of 74 consecutive patients undergoing amniocentesis for karyotype analysis at 16-20 weeks' gestation were included in this prospective age-matched case-control study. The study group (n=38) had abnormal first or second trimester screening test results and normal karyotype results, while controls (n=36) included those admitted for genetic amniocentesis for other reasons who had normal first or second trimester screening test and normal karyotype results. Four markers [interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-alpha, and ischemia-modified albumin (IMA)] were studied in amniotic fluid. RESULTS: The mean age of the women in the study and control groups was 34.0+/-5.6 and 33.6+/-7.2 years, respectively. The women in the study and control groups had similar clinical and laboratory characteristics. The mean amniotic fluid IL-6 (414.84+/-83.96 vs. 343.02+/-110.59, p=0.002) and IL-8 (377.61+/-243.31 vs. 261.90+/-201.29, p=0.029), TNF-alpha (24.91+/-5.78 vs. 21.60+/-5.55, p=0.014), and IMA (1.19+/- 0.10 vs. 1.05+/-0.12, p<0.001) values were significantly increased in the study group when compared to controls. CONCLUSION: The higher amniotic fluid cytokine and ischemia-modified albumin levels in patients with false-positive first or second trimester biochemical Down syndrome screening test may result from subclinical fetal membrane inflammation and/or ischemia.

Ischemia-modified albumin reduction after coronary bypass surgery is associated with the cardioprotective efficacy of cold-blood cardioplegia enriched with N-acetylcysteine: a preliminary study.

BACKGROUND: The aims of this preliminary study were to determine the alteration of serum ischemia-modified albumin (IMA) levels and to investigate whether IMA may be used as an indicator of the cardioprotective efficacy of N-acetylcysteine (NAC) in patients undergoing coronary bypass grafting (CABG). PATIENTS AND METHODS: Forty-four patients were randomized into one of two groups on the basis of cardioplegic strategies, either cold-blood cardioplegia enriched with NAC (50 mg/kg) or cold-blood cardioplegia alone. Serum IMA, cardiac troponin T (cTnT) and malondialdehyde (MDA) levels determined in NAC-enriched patients before and after CABG were compared with those of the NAC-free group. The albumin cobalt binding assay was used for IMA determination. RESULTS: Serum IMA levels were significantly elevated after cross-clamping and peaked at 6 h after reperfusion in the two groups. In NAC-enriched patients, IMA levels determined 6, 12, 24 and 48 h after reperfusion were significantly lower than those of the NAC-free group (p < or = 0.001, p < 0.001, p < 0.001 and p < 0.001, respectively). IMA returned to baseline 24 h after reperfusion differently from cTnT and MDA in the NAC-enriched group. CONCLUSIONS: IMA may be used as not only an indicator of myocardial ischemia-reperfusion injury, but also as a useful indicator of the cardioprotective effect of NAC in CABG.

Elevated concentrations of serum ischaemia-modified albumin in PCOS, a novel ischaemia marker of coronary artery disease.

This prospective case-control study comprised 41 consecutive patients with PCOS and 41 non-PCOS control patients matched for body mass index (BMI) and age (mean age, 22.17 +/- 4.45 and 23.29 +/- 3.11 years, respectively). Serum IMA, fasting glucose, fasting insulin, homeostatic model assessment insulin resistance index (HOMA-IR), prolactin, thyroid-stimulating hormone, LH, FSH, oestradiol, total testosterone, dehydroepiandrosterone sulphate, high-density lipoprotein (HDL) cholesterol, triglyceride, 17-alpha-hydroxyprogesterone and cortisol concentrations were measured. Compared with the control group, women with PCOS had significantly higher concentrations of LH (P < 0.001), LH/FSH ratio (P < 0.001), fasting insulin (P < 0.001), HOMA (P < 0.001) and total testosterone (P = 0.031). Serum IMA concentrations in PCOS women were significantly higher than control group (0.63 +/- 0.26 versus 0.49 +/- 0.16 absorbance units, respectively, P = 0.003, 95% CI 0.05-0.24). Bivariate analysis revealed that serum IMA concentrations were only well correlated with the Ferriman-Gallwey score (r = 0.416, P = 0.007), total testosterone (r = 0.357, P = 0.022) and BMI (r = 0.3751, P = 0.016) in PCOS group. Serum IMA, which has recently been developed as a clinical marker of ongoing myocardial ischaemia, appears to be elevated in PCOS. This may be due to increased androgen concentrations observed in PCOS.

The effects of N-acetylcysteine on antioxidant enzyme activities in experimental testicular torsion.

Testicular torsion is a serious problem in male children and, if not treated at the right time, can lead to subfertility and infertility. The main reason for testicular damage is ischemia-reperfusion injury. A number of chemical substances have been used to protect testes against ischemia-reperfusion injury in experimental animals. The possible protective effect of N-acetylcysteine on testicular tissue after testicular detorsion was examined in the current study. Twenty-four rats were divided into four groups: sham operation, torsion, detorsion, and NAC + detorsion groups (n = 6 for each group). Excluding sham operation group, the rats were subjected to unilateral torsion (720-degree rotation in clockwise direction). After torsion (5 h) and detorsion (2 h), unilateral orchidectomy was performed. Malondialdehyde levels and superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities were determined in testicular tissue. Administration of N-acetylcysteine caused a decrease in malondialdehyde levels and an increase in glutathione peroxidase levels compared to detorsion group. The results suggest that N-acetylcysteine may be a potential protective agent for preventing the negative biochemical changes related to oxidative stress in testicular injury caused by testis torsion.

Cardioprotective effect of cold-blood cardioplegia enriched with N-acetylcysteine during coronary artery bypass grafting.

BACKGROUND: Cold-blood cardioplegia is a well-known method in coronary artery bypass graft surgery, and several authors have used various agents in the enrichment of cold-blood cardioplegia to decrease ischemia-reperfusion injury seen during surgery. N-acetylcysteine, which can increase glutathione levels, is one of the agents added to cardioplegic solutions to decrease myocardial injury. This study was planned to assess the efficiency of N-acetylcysteine-enriched cold-blood cardioplegia on early reperfusion injury in patients with ischemic heart disease undergoing coronary artery bypass grafting, using measurements of cardiac troponin I and malondialdehyde release. METHODS: Thirty patients (11 women and 19 men) with left ventricular ejection fraction greater than 0.40 scheduled for coronary artery bypass grafting were randomly divided into two groups. We used cold-blood cardioplegia enriched with N-acetylcysteine (50 mg per kilogram of body weight) in the first group and cold-blood cardioplegia alone in the second group. Hemodynamic variables and clinical properties of the patients were preoperatively and postoperatively evaluated. Enzyme releases were measured in the early hours after the operation. RESULTS: In the N-acetylcysteine-enriched group cardiac troponin I levels were lower than in the N-acetylcysteine-free group, and this difference was statistically significant. Cardiac troponin I levels increased in both groups in the 6th and 12th hours postoperatively, but there was a statistically significant difference between the two groups. Malondialdehyde levels were significantly higher in the N-acetylcysteine-free group after the 6th, 12th, 24th, and 48th hours postoperatively when compared with the N-acetylcysteine-enriched group. CONCLUSIONS: N-acetylcysteine-supplemented cold-blood cardioplegia minimizes myocardial injury in the early hours after and during the cardiac surgery.

The effects of short-term raloxifene therapy on fibrinolysis markers: TAFI, tPA, and PAI-1.

BACKGROUND: Markers of fibrinolysis, thrombin-activatable fibrinolysis inhibitor (TAFI), tissue-type plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) levels were studied for the evaluation of short-term effects of raloxifene administration in postmenopausal women. METHODS: Thirty-nine postmenopausal women with osteopenia or osteoporosis were included in this prospective, controlled clinical study. Twenty-five women were given raloxifene hydrochloride (60 mg/day) plus calcium (500 mg/day). Age-matched controls (n = 14) were given only calcium. Plasma TAFI, tPA, and PAI-1 antigen levels were measured at baseline and after 3 months of treatment by commercially available ELISA kits. Variations of individuals were assessed by Wilcoxon's test. Relationship between those markers and demographic characteristics were investigated. RESULTS: Three months of raloxifene treatment was associated with a significant decrease in the plasma TAFI antigen concentrations (16% change, P < 0.01), and a significant increase in tPA antigen concentrations (25% change, P < 0.05). A significant correlation was found between baseline TAFI antigen concentrations and the duration of amenorrhea (P < 0.05; r = 0.33). CONCLUSION: We suggest that the increased risk of venous thromboembolism due to raloxifene treatment may be related to increased tPA levels, but not TAFI levels.

Effects of Turkish pollen and propolis extracts on respiratory burst for K-562 cell lines.

Bee-collected pollen and propolis are apicultural products which are composed of nutritionally valuable substances and contain considerable amounts of polyphenol substances which may act as potent antioxidants. We wanted to show if respiratory burst within a cancer cell lines could be influenced when incubated with pollen and propolis extracts or not. Pollen and propolis extracts at concentrations of 50, 25, 12.5 and 0 mg/ml were prepared by dimethyl sulfoxide (DMSO). K-562 cell cultures and mononuclear cell (MNC) cultures prepared from a peripheral blood sample to serve as control cells were incubated with extracts for 24 h. Determination of respiratory burst was carried out by intracellular dichlorofluorescein (DCFH) test by using flow-cytometric fluorescence analysis. While about 90% and 66% fluorescence was detected at zero concentrations for both K-562 and MNC cultures, fluorescence positivity decreased (between 3.8% and 11.8%) as concentrations of both propolis and pollen extracts increased for K-562 cell culture, but unchanged (between 20% and 83%) for MNC culture. It was concluded that pollen and propolis extracts inhibit respiratory burst within cancer cell lines probably by their antioxidant potentials.

Acute phase effects of ATP-MgCl2 on experimental spinal cord injury.

The purpose of this study was to study the acute phase effects of adenosine triphosphate (ATP)-MgCl2 on experimental spinal cord clip compression injury. Spinal cord clip compression injury was performed on 36 albino Wistar rats. The rats were divided into five groups. T4-T8 total laminectomy was performed on all rats. Group 1: sham-operated group. Group 2: clip compression group. In group 3, ATP-MgCl2 (100 micro mol/kg) was given 2 min before the "clip compression injury." In group 4, ATP-MgCl2 (100 micro mol/kg) was given 5 min after the clip compression injury. In group 5, ATP MgCl2 (100 micro mol/kg) was administered 8 h after the injury. The spinal cords were excised for a length of 2 cm and deep frozen at -76 degrees C. Tissue malondialdehyde (MDA) levels were used to determine the effects of ATP-MgCl2 on spinal cord lipid peroxidation. In the groups in which ATP MgCl2 was administered after the clip compression injury (groups 4 and 5), the decrease in spinal cord MDA levels was statistically significant when compared with those of the injury group (group 2). Although MDA levels of group 4 were lower than those of group 5, this difference was not statistically significant. Administration of the ATP-MgCl2 before the clip compression injury (in group 3) did not have a statistically significant effect on lipid peroxidation when compared with the injury group (group 2). In this study, we found that ATP-MgCl2 has decreased lipid peroxidation in spinal cord injury and protected the spinal cord from secondary injury after the trauma. We concluded that ATP-MgCl2 may be used in the treatment of spinal cord injuries in conjunction with the other treatment modalities, but further investigations are mandatory.