THE EFFECT OF GLUCOVANCE THERAPY ON BIOMECHANICAL DETERIORATION OF BONE IN STREPTOZOTOCIN-INDUCED DIABETIC RATS.

AIM: Is to evaluate the influence of glucovance therapy on biomechanical properties of bone in streptozotocin - induced diabetes mellitus (DM) in rats. MATERIALS AND METHODS: A total of 28 male Wistar-Albino rats (12-week-old; 210-300 g) were divided into 4 groups including control (C; no treatment; n=7), sham [Sh; distilled water (gavage, for 8 weeks); n=7], diabetes [DM; streptozotocin (45 mg/kg, single i.p injection); n=7] and diabetes+ Glucovance treatment [DM+G; streptozotocin (45 mg/kg, single i.p injection) + Glucovance (Glucovance, 500/5 mg/kg/day/rat, gavage, for 8 weeks); n=7] groups. Body weight, blood glucose levels (BGLs), bone mineral density (BMD) and geometric/mechanical properties of bone tissue were evaluated. BGLs in diabetic rats were significantly increased compared to non-diabetic rats, while the body weights were decreased (p<0.05). RESULTS: A significant difference was not detected between groups with regard to cross-sectional area of diaphyseal femur (p>0.05). Maximum load, energy absorption capacity, ultimate stress, ultimate strain, toughness and displacement were shown to decrease and stiffness was shown to increase in DM rats (p<0.05). Ultimate stress and maximum load were significantly increased in DM+G groups compared to DM groups (p<0.05). CONCLUSION: Glucovance treatment seems to be effective in restoration of biomechanical deterioration of bone specific to STZ-induced DM.

Comparing the effects of fluticasone, anti-IgE and anti-TNF treatments in a chronic asthma model

BACKGROUND: Corticosteroids are used in the treatment of asthma. The aim of this study was to determine the efficacy of anti-IgE and anti-TNF alpha as asthma treatments. METHODS: A mouse model of chronic asthma was developed. The fluticasone group was exposed to fluticasone and the anti-IgE and anti-TNF groups were administered anti-IgE or anti-TNF. IL-4, and IgE levels were measured, and histological analysis, pathological analysis and miRNA-126, miRNA-133a analyses were applied. RESULTS: The cell concentration in the BAL fluid decreased in all the treatment groups. The rate of perivascular and peribronchial cell infiltration decreased in the lung in the high-dose anti-IgE and anti-TNF groups. Smooth muscle thickness decreased in the lung tissue in the low-dose anti-IgE and anti-TNF groups. Bronchial wall thickness decreased in the lung tissue in the fluticasone+anti-IgE group. The IL-4 level in BAL fluid decreased in the high-dose anti-IgE, fluticasone+anti-IgE and anti-TNF groups. IgE levels increased in the BAL fluid in the high-dose anti-IgE and anti-TNF groups. The lymphocyte level increased in the BAL fluid in the high-dose anti-IgE group. The macrophage level decreased in the BAL fluid in the anti-TNF group. The relative expression of miRNA-126 increased in all groups. The relative expression of miRNA-133a decreased in the placebo and fluticasone groups. The relative expression of miRNA-133a increased in the low-dose anti-IgE, high-dose anti-IgE, fluticasone+anti-IgE and anti-TNF groups. CONCLUSIONS: The results showed that anti-IgE is successful as a treatment. Fluticasone+anti-IgE and anti-TNF were seen to be superior to other therapeutic modalities when used for prophylaxis

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Comparing the effects of fluticasone, anti-IgE and anti-TNF treatments in a chronic asthma model.

BACKGROUND: Corticosteroids are used in the treatment of asthma. The aim of this study was to determine the efficacy of anti-IgE and anti-TNF alpha as asthma treatments. METHODS: A mouse model of chronic asthma was developed. The fluticasone group was exposed to fluticasone and the anti-IgE and anti-TNF groups were administered anti-IgE or anti-TNF. IL-4, and IgE levels were measured, and histological analysis, pathological analysis and miRNA-126, miRNA-133a analyses were applied. RESULTS: The cell concentration in the BAL fluid decreased in all the treatment groups. The rate of perivascular and peribronchial cell infiltration decreased in the lung in the high-dose anti-IgE and anti-TNF groups. Smooth muscle thickness decreased in the lung tissue in the low-dose anti-IgE and anti-TNF groups. Bronchial wall thickness decreased in the lung tissue in the fluticasone+anti-IgE group. The IL-4 level in BAL fluid decreased in the high-dose anti-IgE, fluticasone+anti-IgE and anti-TNF groups. IgE levels increased in the BAL fluid in the high-dose anti-IgE and anti-TNF groups. The lymphocyte level increased in the BAL fluid in the high-dose anti-IgE group. The macrophage level decreased in the BAL fluid in the anti-TNF group. The relative expression of miRNA-126 increased in all groups. The relative expression of miRNA-133a decreased in the placebo and fluticasone groups. The relative expression of miRNA-133a increased in the low-dose anti-IgE, high-dose anti-IgE, fluticasone+anti-IgE and anti-TNF groups. CONCLUSIONS: The results showed that anti-IgE is successful as a treatment. Fluticasone+anti-IgE and anti-TNF were seen to be superior to other therapeutic modalities when used for prophylaxis.

Role of ischemic modified albumin in the early diagnosis of increased intracranial pressure and brain death.

AIM: Increased intracranial pressure following trauma and subsequent possible development of brain death are important factors for morbidity and mortality due to ischemic changes. We aimed to establish the role of ischemic modified albumin (IMA) in the early diagnosis of the process, starting with increased intracranial pressure and ending with brain death. MATERIALS AND METHODS: Eighteen Wistar-Albino rats were divided into three groups; control (CG, n = 6), increased intracranial pressure (ICPG, n = 6), and brain death (BDG, n = 6). Intracranial pressure elevation and brain death were constituted with the inflation of a balloon of a Fogarty catheter in the epidural space. In all three groups, blood samples were drawn before the procedure, and at minutes 150 and 240 for IMA and malondialdehyde (MDA) analysis. RESULTS: Serum IMA levels at 150 and 240 minutes were higher in ICPG than in CG (p < 0.05). IMA levels were similar in ICPG and BDG. Serum MDA levels at 150 and 240 minutes increased in ICPG and BDG groups compared to CG (p < 0.05). MDA levels were similar in ICP and BD groups. CONCLUSION: IMA should be considered as a biochemical parameter in the process starting from increased intracranial pressure elevation and ending at brain death (Tab. 3, Fig. 5, Ref. 31).

Quantitative changes in testicular structure and function in rat exposed to mobile phone radiation.

The possible effects of the electromagnetic fields (EMF) generated by mobile phones on reproductive functions have been discussed in recent years. The aim of this study was to evaluate the effects of EMF emitted from mobile phones on the rat testis morphology and histopathology using stereological techniques. We also investigated cortisol, testosterone, FSH and LH levels. A total of thirty-two (n = 32) male Wistar albino rats were used in this study. Animals were randomly divided into four groups as control (C, n = 8), sham (Sh, n = 8), mobile phone speech (Sp, n = 8) and mobile phone standby (ST by). Morphometric measurements were made with the help of a computer-assisted stereological analysis system. The testis weight and volume were significantly lower in the EMF exposed groups. The mean volume fraction of interstitial tissue was higher, but the volume fraction of tubular tissue was lower in the EMF-exposed groups. The mean tubular and germinal tissue volume, seminiferous tubule diameter and germinal epithelium height were also lower in EMF exposed groups. The cortisol levels in the EMF-exposed groups were significantly higher. In conclusion, the EMF created by mobile phones caused morphologic and histological changes by the affecting germinal epithelium tissue negatively.

Leaching of nano-ZnO in municipal solid waste.

Despite widespread use of engineered nanomaterials (ENMs) in commercial products and their potential disposal in landfills, the fate of ENMs in solid waste environments are still not well understood. In this study, the leaching behavior of nano ZnO -one of the most used ENMs- in fresh municipal solid waste (MSW) was investigated. Batch reactors containing municipal solid waste samples were spiked with three different types of nano ZnO having different surface stabilization. The leaching of ZnO was examined under acidic, basic and elevated ionic strength (IS) conditions. The results of the 3-day batch tests showed that the percent of the added nano-ZnO mass retained within the solid waste matrix ranged between 80% and 93% on average for the three types of nano-ZnO tested. The pH and IS conditions did not significantly influence the leaching behavior of ZnO. To further analyze the behavior of ZnO in the MSW matrix, a kinetic particle deposition/detachment model was developed. The model was able to reproduce the main trends of the batch experiments. Reaction rate constants for the batch tests ranged from 0.01 to 0.4 1/hr, reflecting the rapid deposition of nano-ZnO within the MSW matrix.

Leaching potential of nano-scale titanium dioxide in fresh municipal solid waste.

With the rapid development in nanotechnology in recent years, the number of commercially available products containing engineered nanomaterials (ENMs) has increased significantly. It is expected that large fractions of these ENMs will end up in landfills for final disposal. Despite the wide use of ENMs, little data is available on their fate within landfills. This study examined the leaching behavior of nanoscale titanium dioxide (nano-TiO2), one of the mostly used ENMs, in fresh municipal solid wastes (MSWs). Batch reactors containing municipal waste samples were spiked with a range of nano-TiO2 concentrations at different pH and ionic strength conditions. The Ti concentrations in leachate decreased rapidly and reached steady state after about 12-24 h. Results suggest that, for the environmental conditions considered, approximately 3-19% of the added nano-TiO2 remained in leachate. Batch tests conducted with individual synthetically-prepared solid waste components also showed low leaching potential (5.2% for organic waste, 3.3% for glass, 1.7% for both textile and paper and 0.6% for metal), indicating that all components of MSW contributed to the retention of the nano-TiO2 mass within the solid matrix.

Relationship between the level of hippocampal leptin receptor gene expression and learning performance in diabetic rats.

Diabetes mellitus may be associated with impaired cognitive function. Decreased peripheral glucose regulation was associated with decreased general cognitive performance, memory impairments, and atrophy of the hippocampus, a brain area that is key for learning and memory. Leptin that is a peptide hormone, acts in the hippocampus where it facilitates the induction of long-term potentiation and enhances NMDA receptor mediated transmission. The aim of the present study is to investigate possible relationship between the hippocampal leptin receptor gene expression and learning performance in streptozotocin (STZ) induced diabetic rats. In this study was conducted on a total of 40 Winstar albino female rats, including a control group consisting of 20 rats and experimental group comprising of 20 rats in which diabetes was induced by means of STZ administration. Leptin receptor gene expression was detected in hippocampal samples by using real time-PCR. According to the evaluation, the learning performance of rats with induced diabetes was found to be same throughout the first 3 days after STZ in comparison to the control group rats. End of the 45 days the learning performance of the control group was found to be better than the diabetic group (p<0.05). Hipocampal leptin receptor expression was found lower in diabetic group than the control group (p<0.05). The results provide evidence that leptin receptor gene may related to learning performance in diabetic rats. Further, detailed studies are needed to address the exact role of leptin and related molecules in learning performance.

The effects of dexmedetomidine on pulmonary artery pressure in experiment.

AIM: The primary purpose of this study is to assess the effects of dexmedetomidine (DEX) infusion on pulmonary artery pressures (PAP), heart rate (HR), and mean arterial pressure (MAP) in pigs. The secondary purpose is to evaluate whether DEX infusion via the pulmonary artery has any beneficial effect over the peripheral IV route. MATERIALS AND METHODS: Sixteen healthy male pigs (25-35 kg) scheduled for laparoscopy training were used in this study. The animals were randomly allocated into two groups: Group I (n = 9): A loading dose of 1 µg/kg DEX was administered over 10 minutes followed by an infusion of 0.5 µg/kg/hr for one hour via the pulmonary artery catheter. Group II (n = 7): A loading dose of 1 µg/kg DEX was administered over 10 minutes followed by an infusion of 0.5 µg/kg/hr for one hour via the peripheral venous catheter. Mean PAP, HR, MAP, SpO2, and ETCO2 were recorded at 5, 10, 15, 30, 45, and 60 minutes after the initiation of the DEX infusion. RESULTS: Heart rate and MAP were similar in both groups at all time points. Also, neither the HR nor the MAP deviated from the basal values in Groups I and II at any time point. The mean PAP values were similar in Groups I and II, and in Group I, the mean PAP values were similar to Group I's basal value at all time points. However, in Group II, the mean PAP values at 5, 45, and 60 minutes were significantly lower than Group II's basal value (p = 0.023, p = 0.041, p = 0.015, respectively). CONCLUSION: DEX infusion did not elevate the mean PAP and the results from the administration of DEX through the peripheral vein and pulmonary artery were similar (Tab. 3, Ref. 13).

N-acetylcysteine ameliorates nitrosative stress on radiation-inducible damage in rat liver.

PURPOSE: The present study was designed to investigate the potential radioprotective effects of N-acetylcysteine (NAC) on radiation-induced nitrosative stress caused by gamma irradiation (single dose, 6 Gy) in rat liver. METHODS: The rats (n=40) were divided randomly and equally into 4 groups: Control (C), Radiation (R), R+NAC (received irradiation and 1,000 mg/kg of NAC) and R+WR-2721 (received irradiation and 200 mg/kg of WR-2721). Liver tissue of each animal was harvested and utilized for 3-nitrotyrosine (3-NT) detection using high-performance liquid chromatography- ultraviolet (HPLC-UV) system. RESULTS: In the R rats, 3-NT levels significantly increased when compared to those of the C rats (p<0.05). There were no significant differences in the 3-NT levels among R+NAC and R+WR-2721 rats. Histologically examined liver tissue samples showed no obvious differences. CONCLUSION: The present study suggests that irradiation has a negative effect on the cellular proteins by enhancing 3-NT formation. The prophylactic use of NAC seems to reduce the nitrosative damage during radiotherapy.

Significance of analytical parameters for the understanding of natural organic matter in relation to photocatalytic oxidation.

In this review, special interest was devoted to provide information on the surrogate parameters expressing both quality and quantity of organic matter for the understanding of the photocatalytic oxidation of humic substances. Detailed investigation was directed to the application of photocatalysis with reference to source, origin and modeling of organic matter. Evaluation of the literature findings emphasizes that organic matter taken from natural waters are site specific and should be characterized in detail to be comparable to other studies. Taking into account the photocatalytic degradation studies of natural organic matter, humic substances, humic acids and fulvic acids in slurry systems, a procedure could be deduced that depends on the selection of a standard model sample with a representative concentration, selection of a standard photocatalyst and dose (e.g., TiO2 Degussa P-25, 0.25 mg mL(-1)), application of standardized reaction conditions such as light intensity, pH, and temperature. Furthermore, standardized filtration step avoiding organic leaching and selection of the most suitable analytical parameter are the crucial points to be considered. The use of such a protocol could form a basis for the determination of "relative degradation efficiency" of any sample containing natural organic matter, humic substances, humic acids and fulvic acids regardless of dependency on source and origin.

The effect of lidocaine on the endothelium damage in rabbit vein grafts.

OBJECTIVE: To investigate the effects of perivascular and intravenous application of lidocaine on venous endothelial morphology of harvested rabbit vein graft. METHODS: This study was conducted in Gazi University Animal Research Laboratory, Ankara, Turkey in March 2009. Three ear veins of each rabbits (n=6) were used. Control group (Group C, n=6 vessels), vein segment was excised from the distal end. Perivascular group (Group P, n=6); 2 ml lidocaine 1% was injected in the perivascular area of the second vein of the same ear, and the vein segment was excised. Intravascular group (Group I, n=6); the vein in the second ear was clamped and 2 ml of lidocaine 1% was administered intravascular, and 5 minutes later, a 2 cm vein segment was excised. Nitric oxide synthase and thiobarbutiric acid reactive substance levels were measured, and histopathologic examination was performed to assess the effects of lidocaine administration. RESULTS: Histopathological findings in groups C, P and I were similar. There were lower thiobarbituric reactive substances level in groups I (p=0.024) and P (p=0.041) than the control group. Nitric oxide synthase activity was higher in groups I (p=0.026) and P (p=0.037) when compared to group C. CONCLUSION: Our results showed both perivascular infiltration and intravascular administration could prevent the consequences of endothelium damage that occurs during the harvesting of veins.

N-acetylcysteine ameliorates γ-radiation-induced deterioration of bone quality in the rat femur.

This animal study evaluated the radioprotective effects of N-acetylcysteine (NAC) and amifostine on the biomechanical properties of bone in Wistar albino rats of both genders. The rats were randomly divided into four groups of eight: a control group (C); a group given a single dose of 40 Gy of γ-irradiation (R); a group given γ-irradiation plus 200 mg/kg amifostine (R + amifostine); and a group given γ-irradiation plus 1000 mg/kg NAC (R + NAC). Extrinsic and intrinsic properties of bone, bone mineral density (BMD) and the cross-sectional area of the femoral shaft were determined. The cross-sectional area was significantly higher in the R + NAC and R + amifostine groups compared with the R and C groups. The BMD, maximum load and stiffness were also significantly higher in the R + NAC and R + amifostine groups than in the R group, and energy absorption capacity was higher in the R + NAC group than in the R group. These findings indicate that NAC and amifostine preserve bone quality in rats exposed to γ-irradiation.

The preventive effect of N-acetylcysteine on radiation-induced dermatitis in a rat model.

PURPOSE: We investigated the potential radioprotective effects of N-acetylcysteine (NAC) comparing its effects with that of amifostine (WR-2721), as a representative of clinically used radioprotector, in ameliorating skin injury from irradiation in rats (single dose, 18 Gy to the left hind legs of the rats). METHODS: The rats (n=28) were divided randomly and equally into 4 groups: Control (C), Radiation (R), R+WR-2721 (received irradiation and 200 mg/kg of WR- 2721) and R+NAC (received irradiation and 1000 mg/kg of NAC). Acute skin reactions were assessed every 3 days by a radiation oncologist and a biophysicist. Light microscopic findings were assessed by an expert pathologist. RESULTS: Clinically and histopathologically, irradiation increased dermatitis when compared with the control group (p<0.05). The severity of radiodermatitis of the rats in the R+NAC and R+WR-2721 groups was significantly lower than in the R group (p<0.05). The protective effects of NAC and WR-2721 on irradiation-increased dermatitis were clinically and histopathologically similar (p>0.05). CONCLUSION: The study gives clues about the beneficial effects of NAC against radiation-induced dermatitis.

Evaluation of a local anaesthesia regimen using a subphrenic catheter after gynaecological laparoscopy.

BACKGROUND AND OBJECTIVE: The purpose of intraperitoneal local anaesthetic administration is to block visceral nociceptive conduction and to provide an additional route of analgesia. The present study evaluates the effects of sequential injections of bupivacaine on postoperative pain through a subphrenic catheter. METHODS: In this double-blinded controlled study, patients scheduled for gynaecological laparoscopy were randomly divided into two groups. One group received 20 mL of saline with 1:200000 epinephrine through a subphrenic catheter before the incision closure and at 4-hourly intervals for the first postoperative 20 h. The second group received 20 mL of bupivacaine 0.125% with 1:200000 epinephrine at the same injection times. Postoperative pain scores and consumption of analgesics were compared. RESULTS: There were no statistical differences in pain scores at rest or incidence of shoulder pain between the two groups, but the patients of the bupivacaine group reported lower pain scores on coughing only in the first hour postoperatively (P = 0.007). Although the patients consumed comparable amounts of metamizole and ondansetron, the number of patients requiring supplemental meperidine and flurbiprofen in the bupivacaine group were significantly lower than in the saline group (P < 0.05). CONCLUSIONS: This study demonstrates that intraperitoneal bupivacaine may reduce pain on coughing in the early postoperative period and the consumption of analgesics postoperatively. The subphrenic catheter technique had no impact upon pain at rest and shoulder-tip pain after gynaecological laparoscopy.

Comparison of ephedrine and ketamine in prevention of injection pain and hypotension due to propofol induction.

BACKGROUND AND OBJECTIVE: This prospective, double-blind, randomized, placebo-controlled study compares the effects of ephedrine and ketamine on injection pain, and hypotension from propofol. METHODS: After obtaining the approval of the Ethics Committee, 75 patients (ASA I-II) scheduled for elective operations with general anaesthesia were divided into three groups. Saline 2 mL (Group S, n = 25), ketamine 0.5 mg kg(-1) (Group K, n = 25) or ephedrine 70 microg kg(-1) (Group E, n = 25) were administered over 5 s after tourniquet application. After releasing the tourniquet, propofol 2 mg kg(-1) was injected in 30 s. Pain was evaluated on a numerical scale (0-10) where 0 represented no pain and 10 the most severe pain possible. Systolic, diastolic blood pressures and heart rates were recorded preoperatively, 1 min after propofol injection, before intubation and 1, 2 and 3 min after intubation in all patients. RESULTS: The incidences of pain in Groups S, E and K were similar (84%, 80% and 72%, respectively). The mean pain score in Group K (2.1, SD 3.1) was significantly lower than those of Groups S and E (4.9, SD 2.6 and 4.6, SD, 3.3, respectively) (P < 0.05). The systolic and diastolic blood pressure values in Group K (120 +/- 27 mmHg) and Group E (123 +/- 21 mmHg) before intubation were significantly higher than that of Group S (104 +/- 25 mmHg) (P < 0.05). There was no significant difference between the mean heart rate values of the groups. CONCLUSIONS: Low dose ketamine or ephedrine pretreatment may prevent hypotension due to propofol induction. Despite the reduction in injection pain intensity after ketamine, the study drugs were found to be ineffective in lowering the injection pain incidence.

Increased insulin-like growth factor-I levels in women with polycystic ovary syndrome, and beneficial effects of metformin therapy.

We aimed to investigate whether metformin would reverse the endocrinopathy of polycystic ovary syndrome (PCOS), allowing resumption of cyclic ovulation and regular menses, and whether metformin causes any change in the serum concentration of insulin-like growth factor-I (IGF-I) in patients with PCOS. Fifty-eight women with PCOS participated in the study and received metformin at a dose of 850 mg three times a day (total 2550 mg) for 16 weeks. Serum concentrations of luteinizing hormone, follicle stimulating hormone, estradiol, free testosterone, total testosterone, 17-hydroxyprogesterone, dehydroepiandrosterone sulfate, fasting insulin, IGF-I, sex hormone binding globulin and insulin-like growth factor binding protein-1 (IGFBP-1) were evaluated before and after metformin treatment. Patients were divided into two groups as responders and non-responders according to the achievement of regular menstrual periods. The mean IGF-I levels decreased significantly on metformin therapy. After 16 weeks of metformin treatment, 55.17% of PCOS patients achieved regular menses. Only the change in serum levels of progesterone and IGF-I on metformin were statistically significant between responders and non-responders; metformin-induced decremental change in IGF-I levels were greater in responders. In conclusion, we observed that elevated IGF-I levels may have a crucial role in many consequences of PCOS in addition to hyperinsulinemia. By decreasing insulin and IGF-I levels, metformin therapy offers additional beneficial effects in resumption of regular menses. Thus, in PCOS patients with elevated levels of IGF-I, metformin may be considered as an appropriate agent to be used for the regulation of menstrual cycles.

An unusual complication of total intravenous anesthesia: mutism.

IMPLICATIONS: We report a case of mutism secondary to total IV anesthesia with propofol, as an unusual complication that we have not found in the literature.

The effects of volatile anesthetics on the Q-Tc interval.

OBJECTIVE: To examine the effects of halothane, isoflurane, and sevoflurane on Q-Tc interval (corrected for heart rate) during inhalation induction of anesthesia. DESIGN: Prospective, double-blind, randomized study. SETTING: Departments of Cardiology and Anesthesiology in a university hospital. PARTICIPANTS: Patients undergoing noncardiac surgery. INTERVENTIONS: A total of 65 American Society of Anesthesiologists physical status I-II patients, aged 16 to 50 years, undergoing general anesthesia, were randomly allocated to receive halothane, isoflurane, or sevoflurane. MEASUREMENTS AND MAIN RESULTS: The time to reach the predetermined end-tidal concentrations of 3 minimum alveolar concentration was 6 to 10 minutes. When compared with preinduction values, heart rate decreased after halothane (p < 0.01) and sevoflurane (p < 0.05) administration; in contrast, heart rate increased after induction of anesthesia with isoflurane (p < 0.05). The mean QRS intervals were not significantly changed after halothane, isoflurane, or sevoflurane. The Q-Tc interval was increased with isoflurane compared with baseline (465 +/- 23 v 441 +/- 18 msec, p < 0.01), not changed with sevoflurane (441 +/- 17 v 434 +/- 19 ms, p > 0.05), and shortened with halothane (426 +/- 23 v 445 +/- 21 msec, p < 0.01). CONCLUSION: Sevoflurane or halothane may be preferred to isoflurane in patients with conditions that are known to induce a prolonged Q-Tc interval. The effects of Q-Tc interval changes resulting from different anesthetic agents on morbidity and the incidence of arrhythmias during anesthesia warrant further investigation.