Search

In the present study, the influence of surfactants on spectral properties of an azo dye in aqueous solutions has been investigated by means of UV-vis spectroscopy in submicellar and micellar concentration range. The spectral signature of the polarity of the azo dye C.I. Reactive Orange 16 (RO16) exhibits sensitivity to the polarity of the dye's environment. This dependence of absorption on microenvironment was used to investigate the ion pair complex formed from electrostatic interaction of a series of alkyltrimethylammonium bromide surfactants (CmTAB, m=12, 14, 16 and 18) with the anionic azo dye RO16. It was observed that the aggregation of surfactant and dye takes place at surfactant concentration far below the critical micelle concentration of the individual surfactant. Aggregation is reflected by the appearance of a new absorption band in the spectrum of the dye. Spectral behavior of dye-surfactant solution with varying concentration of surfactant confirms that electrostatic interaction between dye and surfactant occurs up to a certain level. Beyond this concentration, with addition of surfactant, micelles occur and all dye molecules are accommodated into a normal micelle as monomeric molecules. The short-range hydro phobic interactions are very important factors as the long-range electrostatic forces on the dye-surfactant aggregation in aqueous solution. The effect of the length of the alkyl chain of the surfactant on the complex formation between cationic surfactant and reactive dye was that the hydrophobicity of alkyl chains plays an important role in complex formation. Going from less hydrophobic solution to the more hydrophobic micellar environment, the occurrence of complex is found at lower surfactant concentration. Because the CMC values of dye-surfactant solution are decreased with increasing alkyl chain length.

Combinations of antiproteinurics, including angiotensin I-converting enzyme inhibitors + angiotensin II receptor antagonist + statins, are promising choices in the treatment of steroid-resistant nephrotic syndrome. We aimed to investigate the effects of high doses of immunoglobulin in addition to these combinations in rats with adriamycin-induced nephrosis. The study included 40 rats allocated into five groups: control, nephrotic syndrome without treatment, dual therapy (DT) with enalapril + losartan, triple therapy (TT) with enalapril + losartan + simvastatin, and quadruple therapy (QT) with enalapril + losartan + simvastatin + a high dose of immunoglobulin. The proteinuria levels were not statistically different between DT, TT and QT groups at weeks 5, 8, 12 and 16. At week 16, serum creatinine levels in the QT group were significantly lower than those in the control, DT and TT groups. The glomerulosclerosis index in the DT group was significantly lower than in the TT and QT groups. The scores for interstitial fibrosis and TGF-beta staining were similar among treatment groups. In conclusion, we showed that quadruple therapy including immunoglobulin had a beneficial effect on renal function in the late phase, but it had no additional effects in reducing proteinuria or in glomerulosclerosis score in experimental nephrotic syndrome. Further studies with angiotensin I-converting enzyme inhibitors (ACEIs), angiotensin II receptor antagonists (AIIRAs) and immunoglobulin combinations would offer some benefits in the treatment of nephrotic syndrome.

From the color developing reactions of o-phenylenediamine oxidizing agent and gold(III), the kinetic reactions between both of them in aquaeous solutions were studied using spectrophotometric and differential method. Light absorbances in the visible spectral range are measured as a function of mole fractions of phenylenediamine at a fixed gold(III) concentration and as a function of mole fraction of gold(III) at a fixed o-phenylenediamine concentration at periodic time internal. In the differential method, which was suggested by van't Hoff, one deals with the actual rates of reactions as determined by measuring the slopes of absorbance-time curves. Optimum condition of the reaction were established as pH 6 at lambda=466 nm and room temperature. When the oxidation of o-phenylenediamine by gold(III) was investigated, it was observed that the following rate formula and rate constant were found: v=k[Au+3]1/2[o-phenylenediamine]1/2, k=2.33x10(-2) s-1.

The effect of electrolytes on the interaction between an anionic dye and a cationic surfactant was investigated spectrophotometrically in submicellar concentration range at certain temperature. The spectral change of the azo dye C.I. Reactive Orange 16 (RO16) exhibits a high sensitivity to the polarity of dye's environment. Dodecylpyridinium chloride (DPC) affects the electronic absorption spectra of dye solution that is dye-surfactant interaction results formation of complex and therefore a decrease in maximum absorption spectra (1.577 at 494 nm). The electrolyte cations cause an increase of the absorbance of DPC-RO16 ion-pair complex in the following order: Ca(2+)>Na(+)>NH(4)(+)>K(+)>Mg(2+), also for electrolyte anions Br(-)>Cl(-)>SO(4)(2-). Furthermore, this order can be changeable with increasing electrolyte concentration. The increase on absorbance value with increasing electrolyte concentration is explained as charge screening. The increase or decrease on absorption spectra of RO16-DPC solution depends on concentration range of the electrolyte added. As an increase on absorbance value with increasing electrolyte concentration is explained as charge screening, a decrease in this value for higher concentration of electrolyte is attributed as the charge of micelle shape.

The interaction between an anionic dye C.I. Reactive Orange 16 (RO16) and a cationic surfactant dodecylpyridinium chloride (DPC) in mixtures of DPC and nonionic surfactants poly(oxyethylene)ethers (C(m)POE(n); m = 12, 16 and 18, n = 4, 10 and 23) are investigated spectrophotometrically in a certain micellar concentration range. The spectrophotometric measurements of dye-surfactant systems are carried out as function of mole fraction of surfactant at four different temperatures. For this reason, a typical system was occurred at 1.0 x 10(-2) mol l(-1) for surfactants and at 1.0 x 10(-4) mol l(-1) for dye concentrations. The formation of DPC-RO16 complex in the C(m)POE(n) solutions of different mole fractions in its micellar concentration range have been determined and compared to those obtained in the binary mixtures. From the spectrophotometric measurements has been observed that the addition of nonionic surfactant in to the mixture of DPC-RO16, causes a significant increase of the value of absorbance. This increase explains that the stability of DPC-RO16 complex is reduced in the presence of nonionic surfactant micelles. It can be seen from results; in mixed surfactant solutions, there are DPC-C(m)POE(n) and RO16-C(m)POE(n) interactions in addition to DPC-RO16 interaction. Since the solubilizaton of the DPC-RO16 complex has been appeared in the C(m)POE(n) solution, our results support the conclusion that adding C(m)POE(n) influences the hydrophobic-hydrophilic balance of the studied complex. Furthermore effect of the alkyl chain length and the number of poly(oxyethylene) in nonionic surfactant on values of absorbance have been investigated.

In this study, the right sciatic nerves of 40 rats were used to determine whether a nerve graft within a vein graft might accelerate and facilitate axonal regeneration, compared with a nerve graft alone. The animals were separated into four groups, as follows: group 1, sham control; group 2 (control), segmental nerve resection and no repair; group 3, segmental nerve resection and nerve grafting; group 4, segmental nerve resection and reconstruction with a nerve graft within a vein conduit graft. For all groups, sciatic functional indices were calculated before the operation and on postoperative days 7 and 90. On postoperative day 90, the sciatic nerves were reexposed and nerve conduction velocities were recorded. The sciatic nerves were harvested from all groups for counting of the myelinated axons with a stereological method. No statistically significant differences with respect to return of gait function, axon count, or nerve conduction were noted between groups 3 and 4 (p > 0.05). However, functional recovery in group 4 on postoperative day 90 was significant, compared with group 2 (p < 0.05); the recovery difference between groups 2 and 3 was not significant (p > 0.05). This study was not able to demonstrate any functional benefits with the use of a nerve graft within a vein graft, compared with standard nerve grafting.

Recent studies revealed reverse remodeling in left ventricle with cardiac resynchronization therapy (CRT). However, effects on left atrial remodeling, left atrial total emptying fraction and left atrial spontaneous echo contrast (SEC) have not been adequately evaluated. The aim of this study was to investigate the long-term changes in SEC, left atrial reverse remodeling, and left atrial total emptying fraction after CRT. Twenty patients with systolic heart failure and complete left bundle-branch block underwent implantation of biventricular pacemaker devices. Transthoracic and transesophageal echocardiography were performed one week before and one and six months after pacemaker implantation. After biventricular pacemaker implantation, significant clinical improvement was observed in all patients. Left atrial maximal and minimal volumes showed a significant progressive decline after CRT (reverse remodeling). Left atrial total emptying ejection fraction (LATEF) was 33 +/- 19% at baseline and increased to 37 +/- 10% and 41 +/- 11% at the 1st and 6th months respectively (p = 0.01 and p = 0.04). SEC was detected in 18 of 20 patients (90%) at the beginning of the study. After six months SEC disappeared in 5 patients and frequency of SEC reduced to 45%. Decrease in the intensity of the SEC was also statistically significant (at the 1st and 6th months; p = 0.001 and p < 0.001 respectively). Long-term CRT results in atrial reverse remodeling, increases LATEF, and reduces both frequency and intensity of atrial SEC.

A different approach to end in end anastomosis was tested to minimise the undesirable traits of classic and sleeve (telescoping) methods. Our approach aimed to maintain full contact at the level of the anastomosis by using longitudinal matrix sutures as a new invaginating suture technique in microarterial sleeve anastomosis. Classic end-to-end anastomosis with seven to eight stitches, Lauritzen's end-in-end anastomosis with four stitches, and our modified end-in-end anastomosis with two horizontal matrix sutures were made in 10, 20, and 25 rat femoral arteries, respectively. Nine, 17, and 18, respectively were patent at early evaluation; and eight, 13, and 14 at the time of late evaluation. There was no significant difference in between the patency rates of the groups. Histopathological examination showed large strictures and the formation of intra-luminal organised thrombus with thin intramural fibrin precipitation in occluded specimens. The longitudinal matrix sutures in the sleeve anastomoses, which passed through all layers of the vascular wall, injured the intima (a vertical rupture) and constricted the lumen.

Reconstruction options for columellar defects together with membranous septum, nasal base, and upper lip are restricted. We present a case successfully treated with bilateral cheek advancement flaps with upper medial, perialar skin flaps to reconstruct the upper lip, columella, nasal base and membranous septum in a single session. This method provides adequate tissue with minimal cosmetic deformity in a single stage for repairing such compound defects.

The umbilicus is an important and essential aesthetic component of the abdomen. Many surgeons use different methods to relocate umbilicus during abdominoplasties. We prefer to use a simple combination of different well-known principles to form the neo-umbilicus. The main steps of the procedure are to make an elliptical vertical incision, to do vertical abdominal fascial plication, to embed the umbilical stalk in this plication by suturing the umbilical skin and the rectus fascia together to maintain the umbilical dimple, to place it at the vertical incision made in the abdominal skin at a predetermined point. Silk sutures are used for the abdominal fascial plication and neo-umbilical fixation. Liposuction from the neo-umbilicus to xiphoid along the midline of the upper abdomen creates a minimal superior sulcus. In each patient, a three-dimensional umbilicus with sufficient depression was obtained. All patients, including one case with complications, were pleased by the final aesthetic results.

For practice in microsurgery, animal models and microsurgical instruments are required. The use of some synthetic and non-animal materials such as human placenta and other tissues have also been suggested for practicing. The other material that is needed is microsuture. These materials are expensive and often not easily obtained. To meet this requirement, the authors present human hair as a microsuture material for microsurgical practice.

Despite the many methods described for correction of the deviated nose, it still continues to be one of the most challenging problems in rhinoplasty. It is obvious from the literature that the deformities present in the deviated nose can be quite different from patient to patient and that there is no one method that should be used for every deviated nose. Although unilateral osteotomy technique is not a new concept, so far it has not received the interest of plastic surgeons. Shorter operation time, lessened surgical trauma to the nose, lessened intraoperative bleeding, lessened postoperative edema, and lessened recurrence of the deviation are distinct features of the unilateral osteotomy technique that should be considered when planning surgery on such a complex deformity. We present our experiences with unilateral osteotomy and recommend it for patients who have a deviation related to only one side of the nose.

Flap necrosis is still a significant complication in all types of flap surgery. The effect of parenteral pentoxifylline and nitroglycerin in improving survival of ischemic skin flaps was tested in Wistar rats. In the control group (n = 15) the mean viable length of the flaps was calculated to be 6.160 +/- 0.936, and nonnecrotic flap area was found to be 1859.1 +/- 269.3. In the group treated with pentoxifylline and nitroglycerin (n = 15), the mean viable length of the flap was calculated to be 6.907 +/- 0.617, and the mean nonnecrotic flap area was found to be 2078.5 +/- 172.7. In this study results showed that the use of parenteral pentoxifylline and topical nitroglycerin is effective on skin flap survival.

Swiss-Albino male rats were exposed to sulfur dioxide (SO2) (10 ppm) one hour daily for 60 days and the effect on the erythrocyte antioxidant enzyme activities was studied. Erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD), superoxide dismutase (Cu,Zn-SOD), glutathione peroxidase (GSH-Px), catalase (CAT), glutathione-S-transferase (GST) activities and thiobarbituric acid reactive substances (TBARS) of 30 rats (14 controls and 16 sulfur dioxide groups) were measured. There were no significant differences in the catalase and G-6-PD activities of SO2 group as compared with controls. GSH-Px and GST activities in SO2 group were significantly higher than those in the control group. But, there was a significant decrease in the SOD activity. The rate of TBARS formation was enhanced significantly in erythrocytes of the SO2 group relative to the control group. These results reveal that SO2 inhalation enhanced lipid peroxidation in the erythrocyte and influence the antioxidant enzymes of erythrocyte.