Enhanced electrokinetic properties and antimicrobial activities of biodegradable chitosan/organo-bentonite composites.

In this study, chitosan (CS), Na+-bentonite (Na+-BNT) and chitosan/organo-bentonite (CS/O-BNT) biodegradable composites having three different compositions were investigated. Electrokinetic measurements were examined in aqueous medium by taking the effects pH, electrolytes (NaCl and BaCl2), surfactants (CTAB and SDS), and temperature into account. It was noticed that the initial ζ-potential of Na+-BNT shifted from negative (ζ=-35mV) to positive region (ζ=+13mV) with increasing polycationic CS content in the composite structure as aimed. Divalent 2:1 electrolyte (BaCl2) caused to shift the ζ-potentials of all the dispersions to more positive regions. While the most negative effect on ζ-potential of the composites was reached with SDS, which reduced the value of ζ-potential to -39mV for CS(1)/O-BNT composite, the most positive effect was monitored with CTAB (ζ=+40mV) for CS(3)/O-BNT composite. Further, the composites were tested against various bacterial (Gram-positive and Gram-negative) and fungal microorganisms at various concentrations and results obtained were compared with the reference antibiotics and fungicide. According to inhibition zone values accomplished, antibacterial and antifungal activities of the CS/O-BNT composites are increased with increasing CS content as proportional with their positive ζ-potential values.

Evaluation of the protective effect of agmatine against cisplatin nephrotoxicity with 99mTc-DMSA renal scintigraphy and cystatin-C.

BACKGROUND: The aim of the current study was to investigate whether agmatine (AGM) has a protective effect against cisplatin-induced nephrotoxicity. MATERIALS AND METHODS: Thirty-two rats were randomly divided into four groups: (1) Saline (control); (2) Cisplatin (CDDP; 7.5 mg/kg intraperitoneally); (3) Agmatine (AGM; 10 mg/kg intraperitoneally); (4) Cisplatin plus agmatine (CDDP + AGM). Agmatine was given before and two consecutive days after cisplatin injection. All the animals underwent renal scintigraphy with 99mTc-DMSA. The levels of serum creatinine, cystatin C, and blood urea nitrogen (BUN) were measured in addition to examination of the tissue samples with light microscopy. Acute renal injury was assessed with biochemical analyses, scintigraphic imaging, and histopathological evaluation. RESULTS: In the cisplatin group, the levels of BUN, creatinine, and cystatin C were significantly higher than that of the controls. Histopathological examination showed remarkable damage of tubular and glomerular structures. Additionally, cisplatin caused markedly decreased renal 99mTc-DMSA uptake. AGM administration improved renal functions. Serum creatinine, BUN, and cystatin C levels had a tendency to normalize and, scintigraphic and histopathological findings showed significantly less evidence of renal toxicity than those observed in animals receiving cisplatin alone. CONCLUSIONS: Our data indicate that AGM has a protective effect against cisplatin-induced nephrotoxicity. Therefore, it may improve the therapeutic index of cisplatin. In addition, the early renal damage induced by cisplatin and protective effects of AGM against cisplatin nephrotoxicity was accurately demonstrated with 99mTc-DMSA renal scintigraphy.

Bilateral generalised synovial chondromatosis of the knee: Bone scintigraphic demonstration with radiologic correlation.

A 67-year-old woman with a history of bilateral progressive knee pain and swelling was referred for (99m)Tc-methyl diphosphonate bone scintigraphy. Flow and blood pool images showed bilateral heterogeneous increased uptake and delayed phase revealed mass-looking lobulated heterogeneous increased activity in both of knees extending distal part of the femoral shaft, but no other pathologic uptake was found in rest of the body. A diagnosis of synovial chondromatosis was made when correlated with X-ray and computed tomography.(CT) images. This is a rare presentation of generalized synovial chondromatosis involving both knees which demonstrated on bone scintigraphy with X-ray and CT correlation.

Investigation of electrorheological properties of biodegradable modified cellulose/corn oil suspensions.

Considerable scientific and industrial interest is currently being focused on a class of materials known as electrorheological (ER) fluids, which display remarkable rheological behaviour, being able to convert rapidly and repeatedly from a liquid to solid when an electric field (E) is applied or removed. In this study, biodegradable cellulose was modified and converted to their carboxyl salts. Modified cellulose is characterised by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA) and conductivity measurements. Suspensions of cellulose (C) and modified cellulose (MC) were prepared in insulated corn oil (CO). The effects of electric field strength, shear rate, shear stress, temperature, etc. of these suspensions onto ER activity were determined. Rheological measurements were carried out via a rotational rheometer with a high-voltage generator to investigate the effects of electric field strength and particle concentration on ER performance. The results show that the ER properties are enhanced by increasing the particle concentration and electric field strength. Also the cellulose-based ER fluids exhibit viscoelastic behaviour under an applied electric field due to the chain formation induced by electric polarization between particles.

Helicobacter pylori eradication lowers serum asymmetric dimethylarginine levels.

INTRODUCTION: Microbial pathogens, one of them is Helicobacter pylori (H. pylori), have frequently been implicated in the atherogenesis. Endothelium-derived nitric oxide (NO) is synthesized from L-arginine by nitric oxide synthase (NOS) and plays a pivotal role in the regulation of vascular tone. Asymmetric dimethylarginine (ADMA) is the most potent endogenous NOS inhibitor. Elevated levels of ADMA have been reported in many circumstances associated with a high cardiovascular risk. The aim of the present study was to investigate whether the eradication of H. pylori infection affects serum ADMA levels. MATERIALS AND METHODS: Forty-two H. pylori-positive patients were enrolled in the study. Triple therapy for 14 days were given to all patients. Serum ADMA levels were measured at baseline and 2 months after therapy. RESULTS: Eradication was achieved in 34 (81%) patients. The mean serum ADMA levels before and after therapy were 1, 77 ± 0, 30 and 1, 67 ± 0, 29 ng/mL in the group with H. pylori eradicated and 1, 63 ± 0, 28 and 1, 56 ± 0, 32 ng/mL in the noneradicated, respectively. We detected statistically significant decreased serum ADMA levels after therapy in H. pylori eradicated group. CONCLUSION: These findings have indicated that eradication of H. pylori infection may decrease the risk of atherosclerosis and cardiovascular events.

Pharmacological preconditioning with erythropoietin reduces ischemia-reperfusion injury in the small intestine of rats.

AIMS: Considering the implications that arose from several recent experimental studies using recombinant human erythropoietin in rodents, erythropoietin has been regarded as a pharmacological preconditioning agent. The purpose of the present study was to evaluate whether erythropoietin has a preconditioning effect against ischemia and reperfusion injury in the small intestine of the rat. MAIN METHODS: Intestinal ischemia was induced in male Wistar rats by clamping the superior mesenteric artery for 30 min, followed by reperfusion for 180 min. Recombinant human erythropoietin (1000 or 3000 U/kg) or vehicle was administered intraperitoneally 24 h prior to ischemia. After collection of ileal tissue, evaluation of damage was based on measurements of the accumulation of polymorphonuclear neutrophils by technetium-99m-labeled leukocyte uptake, content of malondialdehyde, reduced glutathione, contractile responses to agonists, and an evaluation of histopathological features in intestinal tissue. KEY FINDINGS: Treatment with erythropoietin 24 h before ischemia significantly reduced the tissue content of malondialdehyde and increased that of reduced glutathione. Pretreatment also significantly suppressed leukocyte infiltration into the postischemic tissue, as evidenced by the lower content of myeloperoxidase and technetium-99m-labeled leukocytes. Physiological and histopathological improvements were also significant with the rHuEpo treatment. SIGNIFICANCE: Results of the present study indicate that rHuEpo is an effective preconditioning agent in ischemic injury of the small intestine. Protection provided by recombinant human erythropoietin is closely related to the inhibition of oxidative stress and leukocyte infiltration, which might be among the possible protective mechanisms of erythropoietin in intestinal ischemia and reperfusion.

Lung clearance of 99mTc-DTPA in ankylosing spondylitis.

The association of ankylosing spondylitis (AS) and lung parenchyma abnormalities has been shown in previous studies by radiological and pulmonary function tests. Technetium-99m diethylene triamine pentaacetic acid ((99m)Tc-DTPA) dynamic lung scanning is an easy, noninvasive method to assess alveolar-capillary barrier permeability. We aimed to study the abnormalities in pulmonary clearance of (99m)Tc-DTPA in patients with AS, and the presence of any correlation between this clearance and the radiological and pulmonary function tests. We studied twenty-one nonsmoker patients with AS who were compared to 21 age and sex matched healthy volunteers. All subjects underwent pulmonary function tests and pulmonary scintigraphy with (99m)Tc-DTPA to evaluate pulmonary clearance. Clearance half time (T(1/2)) of (99m)Tc-DTPA through the lungs was calculated by placing a monoexponential fit on the 30 min activity curves. High resolution CT and pulmonary function tests were performed for each patient. Our results showed the following: Spirometric parameters of forced vital capecity (FVC) and theratio of forced expiratory value in 1sec/FVC (FEV1%) scores were worse in patients compared to the control group (P<0.005 and P<0.05, respectively). Clearance half time was longer in AS group than in the control group (58.45+/-7.59 and 51.62+/-4.79 min, respectively; P<0.05). There was a negative correlation between T(1/2) value and FEV1% (r=-0.876, P< 0.01), of AS patients and the control group. Additionally, there were moderate positive correlation between T(1/2) and FVC (r=0.705, P<0.001), weak positive correlation between T(1/2) and FEF2575 (r=0.493, P<0.05), and T(1/2) and DLCO (r=0.444, P<0.05). A positive correlation was found between the duration of the disease and T(1/2) (r=0.44, P<0.05). In conclusion, longer T(1/2) values and lower FVC values in nonsmoker AS patients may suggest not only the pulmonary involvement in AS but also the duration of the disease.

Renoprotective effect of erdosteine in rats against gentamicin nephrotoxicity: a comparison of 99mTc-DMSA uptake with biochemical studies.

Erdosteine is a mucolytic agent having antioxidant properties through its active metabolites in acute injuries induced by pharmacological drugs. This study was designed to investigate the renoprotective potential of Erdosteine against gentamicin (GM)-induced renal dysfunction by using Technetium-99 m dimercaptosuccinic acid (Tc-99 m DMSA) uptake and scintigraphy in rats. For this purpose, male Wistar rats were randomly allotted into one of the four experimental groups: Control, Erdosteine, GM, and GM + Erdosteine groups. GM and GM + Erdosteine groups received 100 mg/kg GM intramuscularly for 6 days. In addition, Erdosteine and GM + Erdosteine groups received 50 mg/kg Erdosteine orally for 6 days. Renal function tests were assessed by serum blood urea nitrogen (BUN), creatinine levels, as well as scintigraphic and tissue radioactivity measurements with Tc-99 m DMSA. Renal oxidative damage was determined by renal malondialdehyde (MDA) levels, by antioxidant enzyme activities; superoxide dismutase (SOD) and catalase (CAT) and activities of oxidant enzymes; xanthine oxidase (XO) and myeloperoxidase (MPO). GM administration resulted in marked renal lipid peroxidation, increased XO and MPO activities and decreased antioxidant enzyme activities. GM + Erdosteine group significantly had lower MDA levels, higher SOD and CAT activities and lower XO and MPO activities, when compared to GM. Also GM + Erdosteine had lower levels of serum BUN, creatinine and higher renal tissue Tc-99 m DMSA uptake and radioactivity with respect to GM. In conclusion, our results supported a protective role of Erdosteine in nephrotoxicity associated with GM treatment.

Analysis of glomerular filtration rate, serum cystatin C levels, and renal resistive index values in cirrhosis patients.

BACKGROUND: The aim of this study was to evaluate the relation of glomerular filtration rate (GFR) to serum cystatin C levels, renal resistive index (RRI), serum creatinine and creatinine clearance in patients with different stages of cirrhosis. METHODS: The study sample was 25 cirrhotic patients (10 females and 15 males; mean age 57.3+/-2.04 years), 10 in the compensated stage without ascites and 15 in the decompensated stage with new-onset ascites. None had azotemia nor were on diuretic treatment. The control group comprised 25 healthy adults (11 female and 14 men; mean age 56.56+/-1.91 years). Serum cystatin C, RRI, serum creatinine and creatinine clearance were measured. GFR was determined by technetium(99m)-diethylene triamine pentaacetic acid renal scintigraphy. RESULTS: Cirrhosis cases had lower mean scintigraphic GFR than controls (64.5+/-4.03 vs. 87.96+/-4.16 mL/min, p<0.05). Serum cystatin C and RRI were significantly higher in the cirrhotic group compared to controls (1.16+/-0.09 mg/L and 0.68+/-0.01 vs. 0.86+/-0.03 mg/L and 0.64+/-0.01, respectively; p<0.05). Subgroup comparative analysis showed that only two parameters, scintigraphic GFR and serum cystatin C, were significantly different between compensated and decompensated cirrhotics (75.62+/-4.9 mL/min and 0.89+/-0.07 mg/L vs. 57.23+/-5.14 mL/min and 1.34+/-0.13 mg/L, respectively; p<0.05). Scintigraphic GFR showed significant correlation with cystatin C, but not with serum creatinine or creatinine clearance (r=-0.877, p<0.05) in decompensated patients. No correlation was observed between scintigraphic GFR and RRI or between serum cystatin C and RRI in all subjects. A receiver operator characteristics curve showed that cystatin C at a cutoff value of 1.01 mg/L can significantly differentiate patients with GFR <70 mL/min with 80% sensitivity and 80% specificity. CONCLUSIONS: Serum cystatin C, but not serum creatinine or RRI measurement, correlates with GFR in each stage of liver failure and has a significant diagnostic advantage in detecting lower GFR in such cases.

Myocardial ischemia caused by a coronary anomaly left anterior descending coronary artery arising from right sinus of Valsalva.

We present the case of a patient in anomalous origin of the left anterior descending coronary artery that caused myocardial ischemia and led to positive myocardial scintigraphic results. Coronary angiography showed that the left anterior descending coronary artery arose from the right coronary ostium-an anomaly that has been associated with chest discomfort-without atherosclerotic lesions. Left circumflex artery and the diagonal branches were arising from the left main coronary artery and the whole coronary tree were free of atherosclerosis.

Role of caffeic acid phenethyl ester, an active component of propolis, against NAOH-induced esophageal burns in rats.

OBJECTIVES: This study was evaluated to investigate the efficacy of caffeic acid phenethyl ester (CAPE), which is a natural honeybee product exhibits a spectrum of biological activities including anti-microbial, anti-inflammatory, antioxidant and anti-tumoral actions, on the prevention of stricture development after esophageal caustic injuries in the rat. METHODS: Thirty healthy male Wistar albino rats were utilized in this study. The rats were randomly allotted into one of three experimental groups: group A (sham) animals were uninjured. Caustic esophageal burn was created by applying 1 ml 37.5% NaOH to the distal esophagus. Group B rats were injured but untreated. Group C rats were injured and received CAPE (10 micromol/kg/day i.p. for 28 days). Efficacy of the treatment was assessed by measuring the esophageal transit time, stenosis index, histopathologic damage score and biochemically by determining tissue hydroxyproline content, lipid peroxidation and antioxidant enzyme activities. RESULTS: The esophageal transit time, the stenosis index, histopathologic damage score and the hydroxyproline level were significantly increased in the untreated group compared with the sham and CAPE-treated groups. Treatment with CAPE decreased tissue hydroxyproline levels, histological damage, and the stenosis index, but except the esophageal transit time. Caustic esophageal burn also increased the lipid peroxidation and decreased the antioxidant enzyme activities in the untreated group. CAPE treatments decreased the elevated lipid peroxidation and also increased the reduced antioxidant enzyme activities. In corrosive esophageal burn group with no treatment, the most consistent findings were degenerative changes and increased in submucosal collagen content, and the luminal narrowing. CAPE treatment protected esophagus. Nevertheless, there was the slight increase in submucosal collagen. CONCLUSIONS: It is concluded that CAPE has a preventive effect on the stricture development after esophageal caustic injuries in the rat.

The effect of lateral osteotomy of septorhinoplasty on nasolacrimal duct functions: a radionuclide imaging study.

BACKGROUND: The aim of this study was to evaluate the effects of lateral osteotomy of septorhinoplasty on nasolacrimal duct functions by dacryoscintigraphy. METHODS: The study group comprised 60 nasolacrimal systems of 30 consecutive patients who underwent septorhinoplasty. Dacryoscintigraphy images were taken in the preoperative period and postoperative 1st week and 3rd month. After Tc-99m pertechnetate instillation, dynamic images were obtained every 15 seconds. For cases of normal drainage, the study was terminated after 10 minutes but when obstruction was suspected, external ocular massage and rapid nasal inspiration were applied and the test was extended for an additional 10 minutes. Systems were classified either as passage without massage (normal nasolacrimal test), passage with massage (physiological obstruction), or presac or postsac obstruction (partial or complete obstruction) according to test results. Transit time was determined for cases with normal test or physiological obstruction. RESULTS: In the preoperative period eight systems (two presac and six postsac) had obstruction. There were a total of 11 (18.3%) additional systems with obstruction (4 presac and 7 postsac) in the 1st postoperative week and patient symptoms were not in complete agreement with the test results in this period. By the 3rd month, nine systems (three presac and six post sac) had obstruction. Transit time was prolonged in both the postoperative 1st week and the postoperative 3rd month tests compared with the preoperative tests (p = 0.000 and p = 0.023, respectively). CONCLUSION: We did not encounter any permanent obstructions after lateral osteotomy of rhinoplasty. Temporary obstructions in the 1st postoperative week improved to normal preoperative status by the postoperative 3rd month.

Evaluation of nasal mucociliary functions with rhinoscintigraphy in coal workers' pneumoconiosis.

OBJECTIVE: To compare nasal mucociliary clearance (NMC) functions in coal workers with pneumoconiosis, coal workers without pneumoconiosis and healthy controls by using technetium-99m-labeled macroaggregated albumin rhinoscintigraphy. METHODS: Sixty-five of the 86 coal workers were clinically documented as suffering from coal workers' pneumoconiosis (CWP group). CWP workers were divided into two groups according to smoking status: 44 smokers (CWP-S) and 21 nonsmokers (CWP-NS). Twenty-one workers without pneumoconiosis (NCWP group) were similarly divided into two groups: 12 smokers (NCWP-S) and 9 nonsmokers (NCWP-NS). Thirty-three healthy male volunteers were selected for the control group [15 smokers (control-S), 18 nonsmokers (control-NS)]. The half-time (t1/2) value for the clearance of the radiopharmaceutical was calculated for each patient. RESULTS: Mean t1/2 values for CWP-S, CWP-NS, NCWP-S, NCWP-NS, control-S and control-NS were 25.10 +/- 7.75, 10.97 +/- 3.24, 14.68 +/- 4.98, 9.17 +/- 3.71, 19.15 +/- 5.04 and 15.08 +/- 5.11, respectively (p < 0.001, Kruskal-Wallis variance analysis). Further, mean t1/2 values of smokers versus nonsmokers in CWP, NCWP and control groups were compared, and it was found that although smoking prolonged nasal transport time in all three groups, the difference was significant only in the CWP group (p < 0.001, p < 0.023 and p < 0.027, respectively, Bonferroni-adjusted Mann-Whitney test). CONCLUSION: Our findings demonstrated a synergistic detrimental effect of smoking with coal dust exposure on nasal transport time.

Myocardial Ischemia caused by a coronary anomaly: left circumflex coronary artery arising from right sinus of valsalva.

We present the case of a patient in whom a previously undetected anomalous origin of the circumflex coronary artery caused myocardial ischemia and led to positive myocardial scintigraphic results. Subsequent coronary angiography showed that the left circumflex coronary artery arose from the right coronary ostium-an anomaly that has been associated with chest discomfort-without atherosclerotic lesions. The peripheral distribution of the left circumflex artery was normal. We describe the clinical and angiographic findings in our patient and discuss the relationship between coronary artery anomalies and ischemia.