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Biomedical subjects

K Kilinç

Publications and source records attributed to K Kilinç.

At least 19 recordsLinked to original sources
PubMed2005

Effect of low-dose N-acetyl-cysteine infusion on tourniquet-induced ischaemia-reperfusion injury in arthroscopic knee surgery.

BACKGROUND: Temporary occlusion of blood flow is used during arthroscopic knee surgery in order to provide a bloodless surgical field. The resulting ischaemia-reperfusion causes lipid peroxidation, which contributes to tissue injury. The aim of the study was to investigate the effect of low-dose n-acetyl cysteine (NAC) infusion on oxidative stress by determining malondialdehyde (MDA) levels during arthroscopic knee surgery. METHODS: Thirty patients, ASA I - II, undergoing arthroscopic knee debridement under a tourniquet were divided into NAC and control groups. Anaesthesia was induced with propofol, fentanyl and vecuronium bromide and maintained with desflurane in an equal parts O(2)-N(2)O mixture. In the NAC group, an infusion of NAC, 5 mg kg(-1).h(-1), was started after intubation, and continued until extubation. An equal volume of saline was infused to the control group. Duration of ischaemia, anaesthesia time, total dose of NAC infused were also recorded. Venous blood and synovial membrane tissue samples were obtained 10 min after the onset of NAC infusion but before tourniquet inflation (t1), after 30 min of ischaemia (t2), and after 5 min of reperfusion following tourniquet release (t3). RESULTS: Plasma MDA levels were significantly lower in the NAC group on reperfusion. There were no differences between the groups in tissue MDA levels at ischaemia and reperfusion times. CONCLUSION: Low-dose n-acetyl cysteine infusion attenuates lipid peroxidation and ischaemia-reperfusion injury in arthroscopic knee surgery requiring tourniquet application.

Acetylcysteine↗
PubMed2003

Ultrastructural effect of sildenafil citrate on corpus cavernosum and other genital organs in female rats.

AIM: To determine the ultrastructural effects of sildenafil on the female genital organs. METHODS: Twenty female cycling Wistar albino rats weighing 250+/-20 g were randomly divided into two groups of 10 each. Rats of one group were gavaged with 0.5 mg.kg(-1).d(-1) of sildenafil 3 days in a week for 4 weeks and the other served as the controls. After cessation of treatment animals were sacrificed by cervical dislocation under methoxyflurane anaesthesia. The clitoris, vagina, uterus and bartholin glands were taken at the estrous and were fixed with 10% formalin solution for light microscopy and 2.5% glutaraldehyde and osmic acid for electron microscopy. RESULTS: Under the light microscope, the fibrocollageous tissue was found increased, the capillaries enlarged and the connecting tissue elements increased in the corpus cavernosum in the treated group. On electron microscopy, increased connective tissue, fibroblasts with notched nucleus, shorten immature collagen fibers without striation were seen. Abundant foldings and penetration with collagen bundles were observed in the basal membrane. Large connection complexes, especially gap junctions among the wide capillary endothelial cells were observed. CONCLUSION: There are evident histological changes due to sildenafil citrate in female rat corpus cavernosum. The clitoris and bartholin glands were the most effected organs. While the histopathological changes of clitoral tissue could be expected, an increase in the mass of bartholin gland was surprising.

Animals↗
PubMed2002

Propofol attenuates myocardial lipid peroxidation during coronary artery bypass grafting surgery.

BACKGROUND: Propofol can scavenge free radicals because it has a chemical structure similar to antioxidants. METHODS: We examined if free radical scavenging occurs with propofol during CABG operations. We studied 24 patients undergoing CABG surgery for triple vessel disease, randomized into two groups. After induction of anaesthesia with fentanyl 10 micrograms kg-1 and midazolam 0.1 mg kg-1, patients in the fentanyl group (n = 14) received fentanyl infusion 10-30 micrograms kg-1 h-1 and patients in the propofol group (n = 10) received propofol infusion 3-6 mg kg-1 h-1 for maintenance of anaesthesia. Atrial tissue biopsies were taken during cannulation for bypass, 45 min after cross-clamp insertion, 5 min after unclamping, and in the decannulation period. Lipid peroxidation was assessed by measurement of thiobarbituric acid reactive substances (TBARS) in the atrial tissue samples. RESULTS: Lipid peroxidation in the propofol group was less than in the fentanyl group (P < 0.05) in all sampling periods. Lipid peroxidation in the fentanyl group increased significantly during cardiopulmonary bypass (CPB) (P < 0.05), but no increase was found in the propofol group (P > 0.05). CONCLUSION: In clinical doses, propofol strongly attenuates lipid peroxidation during CABG surgery.

Aged↗
PubMed2001

C-Reactive protein as a risk factor for left ventricular thrombus in patients with acute myocardial infarction.

BACKGROUND: Elevated C-reactive protein (CRP) has been found to correlate with higher risk for cardiac events in patients with acute myocardial infarction (AMI). It has been suggested that CRP may be involved in initiation process of coagulation; however, the role of CRP level in the formation of left ventricular (LV) thrombus has not been studied. HYPOTHESIS: This study investigated whether CRP is a risk factor for LV thrombus in patients with AMI. METHODS: Clinical, echocardiographic, and biochemical data were analyzed in 141 consecutive patients (aged 57 +/- 13 years; 33 women) with first anterior AMI. Two-dimensional and Doppler echocardiographic examinations were performed on Days 1, 3, 7, 15, and 30. Blood samples were obtained every day during hospitalization. Serum CRP concentrations were measured by an ultrasensitive immunonephelometry method. RESULTS: Left ventricular thrombus was detected in 33 (23.4%) patients. Univariate analysis showed that patients with LV thrombus had a higher peak creatine kinase (CK) level (2,879 +/- 742 vs. 1,693 +/- 1,210 I/U, p = 0.001), higher peak CRP level (14.9 +/- 7.1 vs. 9.2 +/- 6.8 mg/dl, p = 0.001), higher wall motion score index (1.8 +/- 0.2 vs. 1.5 +/- 0.3, p = 0.002), higher apical wall motion score index (2.35 +/- 0.72 vs. 2.07 +/- 0.70, p = 0.001), larger end-diastolic volume (145.2 +/- 43.7 vs. 116.5 +/- 44.2 ml, p = 0.002), larger end-systolic volume (85.4 +/- 37.2 vs. 62.9 +/- 31.6 ml, p = 0.003), and lower ejection fraction (42.1 +/- 12 vs. 47.3 +/- 13, p = 0.04). In multivariate analyses, only peak CK level (p = 0.0001), LV apical wall motion score index (p = 0.001), and CRP levels (p = 0.001) were independent predictors of LV thrombus formation. CONCLUSIONS: These results suggest that CRP is a risk factor for LV thrombus in patients with AMI.

Adult↗
PubMed2001

In vitro and in vivo inhibition of myeloperoxidase with 5-fluorouracil.

OBJECTIVE: Myeloperoxidase (MPO) exists in neutrophils and has an important bactericidal role. During phagocytosis, MPO catalyzes a peroxidative reaction using chloride ion and hydrogen peroxide (H2O2) as substrate. The aim of the present study was to investigate whether 5-fluorouracil (5-FU), a chemotherapeutic agent, has a direct inhibitory effect on MPO and to evaluate some properties of this inhibition. METHODS: The inhibitory effect of 5-FU on MPO was studied in rat tissue, human leukocytes, and leukocytes from cancer patients under 5-FU therapy. MPO was solubilized in a detergent-containing buffer. MPO activity was measured spectrophotometrically through the oxidation of a synthetic substrate tetramethyl benzidine in the presence of H2O2. RESULTS: 5-FU inhibited tissue-associated MPO activity in a dose-dependent but not time-dependent manner with an IC50 value of 0.6 mg/ml. 5-FU also inhibited MPO activity in isolated human leukocytes in a dose-dependent manner, and the IC50 value was 0.75 mg/ml. Using this 5-FU concentration, the inhibitory effect was monitored at different substrate concentrations. Leukocyte MPO activities of patients receiving 5-FU therapy were compared before treatment and after the first, second, and third administration cycles. 5-FU treatment resulted in a significant decrease in leukocyte MPO activity, and repeated 5-FU treatment caused additional decrease. CONCLUSION: Our data showed that 5-FU directly inhibited the MPO activity of human leukocytes in vitro and in vivo. We concluded that, the patients treated with 5-FU should be intensively followed for the risk of infections.

Animals↗
PubMed2001

Free radical changes in rat muscle tissue after exercise.

Intense exercise accompanied by a manifold increase in oxygen utilization over resting conditions has been shown to elevate the probability of the appearance of free radicals. One of the effects of free radicals appears to be the peroxidation of cell membrane lipids resulting in malondialdehyde formation, which is detrimental to cell function. A common method for the measurement of malondialdehyde involves a reaction with thiobarbituric acid. The aim of this study was to evaluate the influence of exercise on concentrations of thiobarbituric acid-reactive substances (TBARS) in the gastrocnemius and soleus muscles of rats. Thirty male rats were used in this study. Soleus and gastrocnemius muscle biopsies were performed and TBARS levels were studied in these two muscles. The rats were randomly assigned to three groups of ten each. Group A was the control group and did not perform exercise. In group B, gastrocnemius and soleus muscle biopsies were performed immediately after exercise, and in group C muscle biopsies were performed on the 2nd postexercise day. The exercise resulted in a significant increase in TBARS in the gastrocnemius muscle. In the soleus, TBARS also increased, but this was not statistically significant. In conclusion, exercise-induced free radical changes may depend on the muscle type studied.

Animals↗
PubMed2001

Effect of melatonin on cerebral edema in rats.

OBJECTIVE: Melatonin (5-methoxy-N-acetyltrypamine), a chemical naturally produced in the pineal gland, has been suggested to be a free radical scavenger and an antioxidant. In the present study, the effect of melatonin on cold-induced brain edema was evaluated by determination of cerebral water content, blood-brain barrier permeability, and areas of infarct; the effects were also studied histopathologically. METHODS: Brain edema was produced in rats by creating a lesion via cortical freezing. Animals were separated into four groups: sham-operated (craniectomy only); control (cold injury); sham-vehicle (cold injury plus saline); and melatonin treatment (cold injury plus melatonin). Melatonin was administered (50 mg/kg intraperitoneally) 15 minutes after the cold injury was induced. Twenty-four hours later, tissue samples from the core, from the periphery of the cold-injured hemisphere, and from the contralateral hemisphere symmetrical to the cold injury were obtained. RESULTS: Melatonin treatment reduced edema (mean +/- standard deviation; 86.22 +/- 1.54% in the control group versus 80.78 +/- 2.76% in the melatonin treatment group, P < 0.001) and blood-brain barrier permeability (45.34 +/- 2.75% in the control group versus 38.26 +/- 3.40% in the melatonin treatment group, P < 0.001) at the periphery of cold injury. Area of infarct reduced from 5.84 +/- 0.58% in the control group to 3.30 +/- 0.89% in the melatonin treatment group (P < 0.001). The effect of melatonin was also confirmed histopathologically. CONCLUSION: Melatonin was found to be neuroprotective in instances of cold-induced brain edema. Thus, melatonin may be a valuable therapeutic agent in the treatment of cerebral edema.

Animals↗
PubMed2001

Detection of head and neck cancer with 99Tc(m) glutathione: a correlative study with tissue glutathione and glutathione S-transferase levels.

In this study glutathione (GSH), a natural tripeptide which plays an important role in detoxification reactions, protecting cells against damage from xenobiotics, has been labelled with 99Tc(m) for the demonstration of head and neck cancer. Twenty-eight patients (10 females and 18 males) with various malignancies of the head and neck were given 740 MBq of 99Tc(m)-GSH intravenously and single-photon emission computed tomography (SPECT) images were obtained at 3 h. Semiquantification was performed by drawing regions of interest on three consecutive transaxial slices and tumour to background ratios were calculated. In addition, GSH and glutathione S-transferase (GST) levels were measured in the tumour samples and in normal tissue which were obtained during surgery. Scintigraphic images showed that there was increased uptake in the tumour compared to the normal contralateral side (tumour/normal tissue (mean +/- SD) = 1.94 +/- 0.76). The tissue analyses revealed increased levels of GST in tumour tissues, but both GST and GSH levels in tumour were not statistically different from those in the normal tissue. We conclude that scintigraphic visualization of head and neck tumours can be attributed to increased demand for GSH in cancer. Protein binding might account for the prolonged retention of 99Tc(m)-GSH in the malignant tissue. Like other peptides, it is accumulated and excreted by the kidneys, which allows clear visualization of the abdomen without interference from gastrointestinal system activity.

Adult↗
PubMed2001

Serum lipoprotein(a) and its relation to left ventricular thrombus in patients with acute myocardial infarction.

It is well known that the incidence of left ventricular (LV) thrombosis is high in patients with acute myocardial infarction (AMI). Due to the high degree of structural homology with plasminogen, lipoprotein(a) may produce thrombogenic effects by modulating the fibrinolytic system. However, the role of Lp(a) level in the formation of LV thrombus has not been studied. This study sought to determine whether Lp(a) is a risk factor for LV thrombus in patients with AMI. We have analyzed clinical, echocardiographic and biochemical data in 102 consecutive patients (aged 58+/-12 years, 92 men / 10 women) with first anterior AMI. Two-dimensional examination was performed on days 1, 3, 7, 15, and 30. Blood samples were obtained within 12 h after the onset of symptoms and before beginning the therapy. Plasma levels of fibrinogen and Lp(a) were measured using enzyme-linked immunosorbent assay and immunonephelometric methods, respectively. LV thrombus was detected in 20 (20.3%) patients. No significant difference was found for admission Lp(a) levels between patients with or without thrombus (30.5+/-17.2 vs 32.3+/-22.4 mg/dl, p = 0.7). Univariate analysis showed that patients with LV thrombus had a higher wall motion score index (1.8+/-0.3 vs 1.4+/-0.3, p = 0.002), a higher peak creatine kinase level (2945+/-898 vs 1805+/-1336, I / U p = 0.004), a larger end-diastolic volume (139.7+/-38.6 vs 114.1+/-41.8 ml, p = 0.04), a larger end-systolic volume (83.1+/-34.3 vs 59.2+/-30.6 ml, p = 0.02 ), and a lower ejection fraction (38+/-12 vs 47+/-11, p = 0.04). In multivariate analyses, only peak creatine kinase level (p = 0.04) and LV wall motion score index (p = 0.002) were independent predictors of left ventricular thrombus formation. These results suggest that Lp (a) is not a risk factor for LV thrombus in patients with AMI. Our data demonstrate that the best predictors of LV thrombus formation after AMI are a high peak creatine kinase level and a high LV wall motion score index.

Aged↗
PubMed2001

Analysis of factors that may affect the enzymatic profile of gingival crevicular fluid: sampling technique, sequential sampling and mode of data presentation.

To evaluate the possible effect of sampling technique and sequential sampling on gingival crevicular fluid (GCF) volume and myeloperoxidase (MPO) activity, 14 patients presenting at least two symmetrical maxillary sites with mild/moderate periodontitis were selected. Two sites in each individual were sequentially sampled using either the deep-intracrevicular or orifice technique. Spectrophotometrically determined MPO levels were presented either as total MPO activity or MPO concentration. Although the clinical periodontal status of the 20 sampling sites were similar, the deep-intracrevicular technique regularly provided larger GCF volumes. With both techniques, the last samples contained the highest GCF volume. During sequential orifice sampling, GCF volume was relatively more stable. In general, a depletion of MPO activity was observed with sequential sampling performed with either of the techniques. Depletion of MPO did not replenish to baseline levels at the end of the 10-min sequential sampling. Although MPO activity showed a general reduction during sequential orifice sampling with both modes of data presentation, total MPO activity and MPO concentration did not match with the deep-intracrevicular technique. Due to the potential of affecting GCF volume/composition, the selection of sampling technique seems to be a critical methodological decision in GCF-profile studies, primarily during sequential sampling. In GCF-profile studies, mode of data presentation should also be considered.

Adult↗
PubMed2001

Protective effect of lisinopril against ischemia-reperfusion injury in isolated guinea pig hearts.

BACKGROUND: In order to determine whether angiotensin-converting enzyme inhibitors (ACEI s) attenuate ischemia-reperfusion injury, we investigated and compared the effects of lisinopril via different routes of administration in an isolated guinea pig heart model of ischaemia reperfusion. METHODS: The effect of lisinopril cardioplegia, oral pretreatment with lisinopril and lisinopril enriched reperfusion solution on myocardium after a normothermic global ischemia of 90 minutes and 30 minutes of reperfusion in the modified Langendorff model was randomly studied in 4 groups (n=8 in each). In all groups, cardioplegic arrest was achieved by administering St. Thomas Hospital Cardioplegic Solution (STHCS). The first group was utilized as the control. In the second group, hearts were arrested with lisinopril (1 micromol/L) enriched STHCS. In the third group, animals were pretreated with oral lisinopril (0.2 mg/kg/twice a day) for ten days. In the last group hearts were again pretreated with oral lisinopril (like in Group 3) and the heart were reperfused with lisinopril enriched (1 micromol/L) Krebs-Henseleit solution during the reperfusion period. RESULTS: Contractility, which was expressed as contractile force (g contractility/g heart weight), was preserved better in the study groups. In the last group, the hearts had the best left ventricular contractile function, where contractile force was 58.4%+/-4.82% of the preischaemic values. In Group I, Group II and Group III they achieved 29.5%+/-5.6%, 41.9%+/-4.9%, and 55.3%+/-5.8% of their preischaemic contractile force values respectively. Creatine kinase leakage was significantly lower and also post- ischaemic coronary flows were significantly higher in the 4th group. Coronary flow after reperfusion increased from 48.0+/-6.2 to 68.0+/-4.51 ml/min.g.heart, in Group IV (p<0.05). CONCLUSIONS: Myocardial MDA and GSH contents showed that there was a correlation between the depletion of myocardial GSH content and increased lipid peroxidation. The myocardial GSH content indicates that the best results were obtained in the last group as compared to the other groups. These preliminary results showed that oral preconditioning improved postischaemic myocardial function and decreased myocardial injury. Because the best results were achieved in the last group, it can be suggested that lisinopril may also play a protective role against reperfusion injury.

Administration, Oral↗
PubMed2000

The protective effect of lisinopril on membrane-bound enzymes in myocardial preservation.

A number of studies have reported that oxidant stress reduces the activity of isolated Na(+)-K(+) ATPase and Ca(2+) ATPase which are known to affect the cell membrane integrity. The aim of the study is to determine whether the administration of lisinopril is able to protect the membrane-bound enzyme levels in isolated guinea pig hearts and also ascertain whether or not a relationship exists between oxygen free radicals and membrane bound Na(+)-K(+) ATPase and Ca(2+) ATPase. Forty guinea pig hearts were studied in an isolated Krebs-Henseleit solution-perfused Langendorff cardiac model. In all groups cardioplegic arrest was achieved by administering St. Thomas' Hospital cardioplegic solution (STHCS). Group 1 (control, n=10) received only STHCS. Group 2 (n=10) were arrested with lisinopril (l micromol l(-1)) added STHCS. Group 3 (n=10) were pretreated with oral lisinopril (0.2 mg kg(-1) twice a day) for 10 days and then arrested with STHCS. Group 4 were also pretreated with oral lisinopril (0.2 mg kg(-1) twice a day for 10 days), arrested with STHCS and reperfused with lisinopril added to Krebs-Henseleit solution (l micromol l(-1)). Hearts were subjected to normothermic global ischaemia for 90 min and then reperfused at 37 degrees C. Pretreatment and addition of lisinopril in the reperfusion buffer improved the levels of membrane-bound enzymes. When the treated groups were compared with control hearts, the best results were achieved in group 4. The Na(+)-K(+) and Ca(2+) ATPase levels increased from 466.38+/-5.99 to 560.12+/-18.02 and 884.69+/-9.13 to 1287.71+/-13.01 nmolPi mg(-1) protein h(-1) respectively (p<0.05). These results suggest that lisinopril protects the cell membrane integrity and lessens free radical-induced oxidant stress.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2000

Do experimentally induced ipsilateral testicular torsion, vas deferens obstruction, intra-abdominal testis or venous obstruction damage the contralateral testis through a common mechanism?

OBJECTIVE: To evaluate if various conditions affecting the ipsilateral testis which also damage the contralateral testis share a common pathway for their effects. MATERIALS AND METHODS: The study comprised five groups of 10 adult rats which underwent surgery to produce (on their left sides); group 1, a sham operation (control); group 2, testicular torsion; group 3, vas deferens obstruction; group 4, an intra-abdominal testis; and group 5, venous obstruction. The ipsilateral and contralateral testes were harvested 4 weeks after surgery. The relative proportions of haploid cells, the mean seminiferous tubular diameter (MSTD), mean testicular biopsy scores (MTBS), and lactate and hypoxanthine levels were determined and compared. RESULTS: The proportions of haploid cells in the ipsilateral and the contralateral testes of groups 2-5 were significantly lower than those of the corresponding testes of the control group. The MSTD and MTBS of the ipsilateral testes in groups 2-5 were also significantly lower than the ipsilateral testes of controls and the contralateral testes within the same groups. While the MSTD and MTBS of the contralateral testes of groups 1 and 5 were not significantly different, those of the contralateral testes of groups 2-4 were significantly less than that of group 1. The lactic acid and hypoxanthine levels of the ipsilateral and contralateral testes were significantly increased in groups 2 and 3. While only the hypoxanthine level of group 5 increased significantly, both variables were not significantly different between the ipsilateral testes of groups 1 and 4. CONCLUSIONS: These four treatments damaged both the ipsilateral and contralateral testes. As the lactic acid and hypoxanthine levels within the contralateral testis were greater than in the controls, testicular torsion and vas deferens obstruction seem to share a common pathway (which may be a reflex decrease in contralateral testicular blood flow) for their effects on the contralateral testis.

Animals↗
PubMed2000

The protective effect of taurine against gentamicin-induced acute tubular necrosis in rats.

BACKGROUND: Taurine, which is the major intracellular free beta-amino acid, is known to be an endogenous antioxidant and a membrane-stabilizing agent. In this study, we wished to know whether taurine altered the concentration of gentamicin in kidney tissue and could protect against gentamicin-induced acute proximal tubular injury. METHODS: Wistar albino rats of both sexes were assigned to three groups, which all received one of the following daily intraperitoneal injections for 8 days: (i) 0.9% sodium chloride (NaCl) alone at the same volume as gentamicin treated rats (group C; n=8); (ii) 100 mg/kg/day gentamicin alone (group G; n=8, four male, four female); or (iii) 100 mg/kg/day gentamicin plus 7.5 ml/kg/day taurine (group G+T; n=9, five male, four female). Urine was collected for 24 h for the determination of urine volume and creatinine. Intracardiac blood was collected for blood urea nitrogen (BUN) and serum creatinine determination. The kidneys were removed, weighed, and the left kidneys were subjected to biochemical analysis for the determination of thiobarbituric acid-reactive substance (TBARS) and lactate levels, and glutathione peroxidase (Gpx) and superoxide dismutase (SOD) activities. The right kidneys were divided vertically in half. The upper halves were used for histopathological examination, by light and electron microscopy. The lower halves were used to detect the gentamicin concentration within the kidney tissue, by high-performance liquid chromatography (HPLC). Changes in body weight and normalized kidney weight were recorded. RESULTS: Taurine treatment reduced gentamicin-induced increases in serum creatinine, 24 h urine volume, BUN and tissue lactate and TBARS levels (0.57+/-0.02 vs 1.06+/-0.08 mg/dl, P<0.001; 9.00+/-1.46 vs 20.9+/-2.73 ml, P<0.001; 25.3+/-1.87 vs 54.1+/-6.99 mg/dl, P<0. 001; 2.56+/-0.10 vs 3.44+/-0.08 micromol/g wet tissue, P<0.001; and 66.4+/-3.41 vs 79.5+/-5.07 nmol/g wet tissue, P>0.05, respectively). Taurine reduced the accumulation of gentamicin within the kidney tissue (233+/-29 vs 494+/-93 microg/g wet tissue, P<0.05). Taurine treatment also prevented body weight loss due to gentamicin administration (17.8+/-1.64 vs -10.0+/-7.08 g, P<0.01) and normalized reduced Gpx and SOD activities (3.46+/-0.16 vs 2.37+/-0. 15 U/g wet tissue, P<0.01; and 15577+/-377 vs 12662+/-577 U/g wet tissue, P<0.01, respectively). Light microscopic examination of the renal tissues from gentamicin-treated rats revealed severe histopathological changes, whereas specimens obtained from taurine-treated rats revealed only mild changes. This finding was supported by electron microscopic examination. CONCLUSIONS: Our observations suggest that taurine treatment attenuates the accumulation of gentamicin within kidney tissue and counteracts the deleterious effect of gentamicin on renal tubular function. They may have potentially important clinical implications.

Acute Disease↗
PubMed2000

The importance of data presentation regarding gingival crevicular fluid myeloperoxidase and elastase-like activity in periodontal disease and health status.

BACKGROUND: The enzymatic profile of gingival crevicular fluid (GCF) is being analyzed with increasing interest, but related studies lack a general consensus on most methodological points, including the appropriate mode of data presentation. METHODS: GCF myeloperoxidase (MPO) and elastase-like activity (ELA) levels were spectrophotometrically determined on a total of 60 subjects who were divided into three equal subgroups as early-onset periodontitis (EOP), adult periodontitis (AP), and healthy. GCF enzyme levels were calculated and evaluated both as total enzyme activity and enzyme concentration. The correlations between these GCF enzymes and clinical periodontal status were also analyzed. RESULTS: With both modes of data presentation, the results regarding MPO activity were consistent. When presented either as total MPO activity or MPO concentration, the periodontally healthy group showed significantly lower MPO activity than the two patient groups (P<0.05). However, two modes of data presentation did not match when GCF ELA was concerned. When data were reported as total ELA, the healthy group exhibited lower enzyme activity (0.02 +/- 0.001 U) than EOP (0.04 +/- 0.01 U) and AP (0.06 +/- 0.02 U) groups; but when reported as concentration, the highest ELA levels were seen in the healthy group (221 +/- 31.53 nmol/min/ml), followed by AP (98.63 +/- 23.03 nmol/min/ml) and EOP (70.49 +/- 12.02 nmol/min/ml) (P<0.05). A strong-positive and significant correlation existed between GCF MPO and ELA. Correlations with clinical parameters were mostly observed with total activities. CONCLUSIONS: The findings of the present study confirm the relationship between GCF ELA and MPO activity and periodontal disease and also support the functional relativity between the two enzymes. Furthermore, based on these findings, it can be suggested that data presentation by use of total activity seems to be more sensitive in both the reflection of the actual enzymatic profile of GCF and also the existing clinical periodontal status. For each GCF component, the validity of different modes of data presentation should be considered.

Adolescent↗
PubMed2000

Analysis of human gingival tissue and gingival crevicular fluid beta-glucuronidase activity in specific periodontal diseases.

BACKGROUND: Beta-glucuronidase (betaG) is one of the enzymes involved in the destruction of non-collagenous components of the extracellular matrix. It is also considered an indicator or predictor of periodontal disease activity. The present study was conducted to determine the presence and the levels of betaG activity in gingival tissue and gingival crevicular fluid (GCF) in periodontal disease and health status. The validity of 2 expressions of data, total betaG activity versus betaG concentration, and the correlations between clinical periodontal status and betaG profile was also evaluated. METHODS: betaG activities in gingival tissues and GCF samples from 57 individuals, divided into 3 equal groups of adult periodontitis (AP), early-onset periodontitis (EOP), and periodontally healthy subjects were spectrophotometrically examined. RESULTS: Both patient groups had higher betaG levels in both gingiva and GCF than controls. Significant differences were observed among all groups when total GCF betaG activities were examined (P <0.05). However, the difference between AP and controls was not significant when concentration values were compared (P >0.05). The highest GCF betaG activity, with both expressions, was detected in EOP group. No absolute correlations between clinical parameters and betaG activity were observed, except for random correlations in the patient groups with mean total betaG activities. Also GCF/gingiva betaG levels and the 2 expressions did not show absolute correlations. CONCLUSIONS: The findings of the present study confirm the relationship between betaG activity and periodontal diseases. The differences in data concerning GCF total betaG activity and betaG concentration may suggest that they are not matching measures. Data presentation seems to be an important factor in GCF/enzyme profile studies.

Adolescent↗
PubMed2000

Comparison of the effects of melatonin and methylprednisolone in experimental spinal cord injury.

OBJECT: Melatonin is a very effective antioxidant agent. This study was performed to investigate the effects of melatonin in experimental spinal cord injury (SCI). The authors also compared its effects with those of methylprednisolone, which also protects the spinal cord from secondary injury because of its antioxidant effect on membrane lipids. METHODS: Adult male albino rats were used for the study, and paraplegia was produced using a previously described weight-drop technique. Melatonin and methylprednisolone were given intraperitoneally by bolus injections of 100 mg/kg and 30 mg/kg, respectively, immediately after induction of trauma. The animals were killed, and 1-cm samples of injured spinal cord were obtained at 1, 24, and 48 hours postinjury. Lipid peroxidation was estimated by thiobarbituric acid test. Electron microscopic studies were performed to determine the effects of melatonin on neurons, axons, and subcellular organelles after experimental SCI. A grading system was used for quantitative evaluation. Following SCI, there was significant increase in lipid peroxidation. In melatonin- and methylprednisolone-treated groups, lipid peroxidation was found to decrease to the baseline (preinjury) levels. There was a significant difference between trauma-alone and treatment groups, but no statistical difference was found between the melatonin- and methylprednisolone-treated groups. Electron microscopic findings showed that SCI produced by the weight-drop technique resulted in profound tissue damage. CONCLUSIONS: Both melatonin and methylprednisolone have been shown to protect neuron, axon, myelin, and intracellular organelles including mitochondrion and nucleus. However, this study provides quantitative evidence that this protection of neurons and subcellular organelles of spinal cord after secondary injury is much more obvious in melatonin-treated rats than those treated with methylprednisolone. In view of these data, melatonin has been shown to be very effective in protecting the injured spinal cord from secondary injury.

Analysis of Variance↗