Effects of different forms of chitosan on intercellular junctions of mouse fibroblasts in vitro.

Chitosan is a linear polysaccharide that has many biomedical applications. We compared the effects of chitosan, in both solution and membranous form, on intercellular adhesion of Swiss 3T3 mouse fibroblasts. Cells were grown as spheroidal cell cultures. Some control cell spheroids were cultured without chitosan and two experimental groups were cultured with chitosan. Chitosan in solution was used for one experimental group and chitosan in membranous form was used for the other. For each group, intercellular adhesion was investigated on days 5 and 10 of culture. Transmission electron microscopy revealed well-defined cellular projections that were more prominent in cells exposed to either membranous or solution forms of chitosan than to the chitosan-free control. Immunocytochemical staining of ICAM-1 and e-cadherin was used to determine the development of intercellular junctions. Compared to the weakly stained control, strong reactions were observed in both chitosan exposed groups at both 5 and 10 days. Cells were treated with 5-bromo-2-deoxyuridine (BrdU) and incubated with anti-BrdU primary antibody to assess proliferation. Both the solution and membranous forms of chitosan increased proliferation at both 5 and 10 days. Cellular viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The MTT assay indicated high cell viability; maximum viability was obtained with the solution form of chitosan at day 5. Chitosan exposure increased the number of intercellular junctions and showed a significant proliferative effect on 3T3 mouse fibroblasts.

The Investigation of Plasma Glucagon-like Peptide-1 Levels in Newly Diagnosed Type 1 Diabetic Children.

OBJECTIVE: To reveal the possible role of glucagon-like peptide-1 (GLP-1) in newly diagnosed Type 1 diabetic children. METHODS: Twenty-five newly diagnosed children and 22 healthy children were included in the study. RESULTS: In oral glucose tolerance tests, no correlation was observed between C-peptide and GLP-1 levels at 0 and 30 minutes, and plasma GLP-1 levels in both groups at 0 and 30 minutes were not statistically different. CONCLUSION: Consequently, fasting and postprandial GLP-1 levels in newly diagnosed Type 1 diabetic children are not different from healthy children. Glucagon-like peptide-1 levels in newly diagnosed Type 1 diabetic children suggest that plasma GLP-1 levels do not have any role in the pathogenesis of Type 1 diabetes mellitus.

Anodic voltammetry of zolmitriptan at boron-doped diamond electrode and its analytical applications.

The electrooxidative behavior and determination of zolmitriptan at a boron-doped diamond electrode were investigated using cyclic, linear sweep, differential pulse and square wave voltammetric techniques. Zolmitriptan undergoes irreversible oxidation at a peak potential of about +0.9 V (vs Ag/AgCl/3 M KCl). DPV and SWV techniques are proposed for the determination of zolmitriptan in phosphate buffer at pH 3.03, which allows quantitation over the two different ranges (8 x 10(-7) - 8 x 10(-6) M and 1 x 10(-5) - 1 x 10(-4) M) in supporting electrolyte for both methods. A linear response was obtained in phosphate buffer over two different ranges (6 x 10(-7) - 8 x 10(-6) M and 1 x 10(-5) - 1 x 10(-4) M) for spiked serum samples at pH 3.03 for both techniques. The repeatability and reproducibility of the methods for all media were determined. The standard addition method was used in serum. Precision and accuracy were also checked in all media. No electroactive interferences from the excipients and endegenous substances were found in the pharmaceutical dosage form and the biological sample, respectively.

Assessment of adrenal functions in patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease and extrarenal manifestations may be observed in many organ systems. Hypothalamus-pituitary-adrenal axis was not evaluated extensively in patients with ADPKD. We aimed to evaluate this axis in these patients. METHODS: Twenty two patients with ADPKD and 27 healthy subjects were enrolled. Basal dehydroepiandrosterone sulfate (DHEAS) levels and cortisol and DHEA responses to low dose short adrenocorticotropin stimulation test were assessed. Correlation analyses of these parameters with glomerular filtration rates (GFR), renal volumes and pain characteristics in patients with ADPKD were performed. RESULTS: Patients with ADPKD had higher basal cortisol levels (12.1 ± 3.4 vs. 9.6 ± 4.3 µg/dL, p=0.033), and higher basal cortisol/DHEAS ratios (0.073 ± 0.05 vs. 0.045 ± 0.02, p=0.015) compared to controls. None of the subjects had inadequate response to adrenocorticotropin stimulation. Patients with ADPKD had lower delta cortisol (absolute increase between peak and basal) levels (10.3 ± 2.8 vs. 12.6 ± 4.2 µg/dL, p=0.026) compared to controls. Subgroup analysis showed that significant differences existed only between female patients and female controls. There was no significant correlation between cortisol levels and renal volumes or GFR. A significant correlation was found only between delta cortisol and pain frequency in female patients. CONCLUSIONS: Patients with ADPKD had higher basal cortisol levels, higher basal cortisol/DHEAS ratios and lower delta cortisol levels compared to controls, indicating promptly stimulated zona fasciculata function. Further studies are needed to confirm these results and to investigate possible underlying mechanisms.

Effects of CIDR-G and melatonin implants, and their combination on the efficacy of oestrus induction and fertility of Kilis goats.

The objective of this study was to compare the efficiency of oestrus induction protocols on Kilis dairy goats kept on a goat farm situated close to Kilis, Turkey. Eighty goats were assigned randomly into four groups of 20 animals each in a factorial arrangement: (i) untreated control (CON), (ii) melatonin implant (MEL), (iii) CIDR-G (CIDR) and (iv) melatonin implant plus CIDR-G (MC). Experiments were performed in mid-anoestrus season under natural photoperiod environment. The differences among treatment groups in oestrus response were significant. Oestrus response was higher in the MC group than in other groups (p < 0.05). A significant difference was observed in the time interval from cessation of treatment to the onset of oestrus among treatments. The CIDR-G treatment reduced intervals from buck introduction to oestrus. The time to onset of oestrus in both the MC and CIDR groups was significantly shorter, compared with the MEL and CON groups (p < 0.05). The number of does kidding and fertility were not different among treatment groups (p > 0.05). Fecundity was similar among goats in all groups. Prolificacy and twining rates showed similar trends as fecundity rates, with no differences (p > 0.05) between treatments. The results of this study showed that oestrus in Kilis does can be effectively induced by using melatonin and CIDR combined treatment, and fertility will not be adversely affected. However, this treatment did not improve fecundity, prolificacy and twining rates.

Application of environmental impact quotient model to Kumluca region, Turkey to determine environmental impacts of pesticides.

Besides the new developments in agricultural technology, intensive use of pesticides poses a great environmental hazard. The unthinking use of pesticides leads to contamination of air, water and soil. There are several pesticide risk indicator models available in the literature to assess pesticide impacts on the applicator and the ecosystem which is an important issue. This paper refers to an application of a pesticide risk indicator model, called Environmental Impact Quotient (EIQ) which was developed to measure the environmental impacts of pesticide active ingredients used in vegetable and fruit production. The application site is the Kumluca region of Turkey, which is well known for its intensive agricultural activities. As the first step in the model application, EIQ values have been calculated for 35 commonly used pesticides in Kumluca. EIO values were then turned into EIQ field use rating results based on the active ingredient percent and application rate. Furthermore, some pesticide management scenarios were evaluated to select the least detrimental pesticide by comparing EIO model results. The EIO model is an easily applied and very helpful tool for pest management practitioners and agricultural specialists. It can be used efficiently to compare different agricultural pest management strategies or programs.

Vitamin E protects against the development of radiation-induced pulmonary fibrosis in rats.

AIMS: To investigate whether the application of vitamin E with or without pentoxifylline could modify the development of radiation-induced pulmonary fibrosis. MATERIALS AND METHODS: Wistar albino rats were supplemented with either vitamin E or pentoxifylline or with both vitamin E and pentoxifylline after a single dose of 14 Gy thoracic irradiation. Supplementation was started the day after irradiation and continued until the rats were sacrificed. As a quantitative end point, the extent of fibrosis was evaluated with a scale from 0 (normal lung) to 8 (total fibrous obliteration of the field) at pathological examination of the lung tissue. RESULTS: A significant reduction in fibrosis was obtained in the group of rats supplemented with vitamin E with or without pentoxifylline, when compared with the group that had irradiation only. CONCLUSION: This experimental study showed that vitamin E supplementation immediately after irradiation protected rats against radiation-induced pulmonary fibrosis. The combination with pentoxifylline was more effective, although pentoxifylline itself had limited efficacy, which was not statistically significant.

T-cell-rich B-cell lymphoma of the spleen presenting with severe hypersplenism.

We report a 19-year-old woman who was presented with B-symptoms, massive splenomegaly, hepatomegaly and hypersplenism. She underwent diagnostic/therapeutic splenectomy. Microscopically, the spleen showed a vaguely micronodular and diffuse proliferation of lymphoid cells in the white pulp that also involved the red pulp. On immunohistochemical staining, this proliferation consisted predominantly of CD3(+), CD7(+) small T cells with the presence of a minor population of CD15(-),CD30(-), CD20(+) large atypical B cells. A liver biopsy also showed a similar morphology to that seen in the spleen. After splenectomy, only the pancytopenia improved. A combined immunochemotherapy regimen (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone) was utilized, which resulted in a complete remission.

Electrochemical methods for determination of the protease inhibitor indinavir sulfate in pharmaceuticals and human serum.

Indinavir sulfate is an inhibitor of the human immunodeficiency virus (HIV) protease. The aim of this study was to determine indinavir levels in serum and pharmaceuticals, by means of electrochemical methods using the hanging mercury drop electrode (HMDE). Indinavir exhibited irreversible cathodic waves over the pH range 2.00-12.00 in different supporting electrolytes. The current-concentration plot was rectilinear over the range from 8 x 10(-7) M to 8 x 10(-6) M with a correlation coefficient of 0.996 for differential pulse voltammetry (DPV) and 8 x 10(-7) M to 1 x 10(-5) M with correlation of 0.999 M for osteryoung square ware voltammetry (OSWV) in Britton-Robinson buffer at pH 10.00. The wave was characterized as being irreversible and diffusion-controlled. The proposed methods were fully validated and successfully applied to the determination of indinavir in capsules and spiked human serum samples with good recoveries. The repeatability and reproducibility of the methods as well as precision and accuracy (such as supporting electrolyte, serum samples) were determined. No electroactive interferences from the endogenous substances were found in serum samples.

Anodic adsorptive stripping voltammetry of the antihypertensive drug candesartan cilexetil at a glassy carbon electrode.

The electrochemical behaviour of candesartan cilexetil (CND) was investigated in an acetonitrile: supporting electrolyte mixture (30% acetonitrile) in the pH range 1.5-11.00 by cyclic, linear sweep, differential pulse (DPV), adsorptive stripping differential pulse (AdSDPV), square wave (SWV) and adsorptive stripping square wave (AdSSWV) voltammetric techniques. CND exhibited one wave and one peak to the anodic direction. The oxidation process was found to be irreversible and adsorption controlled. To obtain good sensitivity, the instrumental and accumulation variables were studied using DPV and SWV techniques. Two linear calibration plots were obtained for both techniques. The detection limits were 9.15 x 10(-7) M and 7.94 x 10(-6) M for AdSDPV and AdSSWV, respectively. The method was validated and successfully applied for the analysis of CND tablets.

Validated RP-hPLC method for the assay of zalcitabine in drug substance, formulated products and human serum.

A HPLC method for zalcitabine determination in bulk form, pharmaceutical dosage forms and human serum has been developed and validated. The proposed method was conducted using a reverse phase technique, and UV monitoring at 265 nm. The mobile phase consisted of methanol: 0.01 M NaH2PO4 (85:15; v/v) adjusted to pH 4.62 with 1 M NaOH. The detector response was linear in the range of 0.015-50 microg mL(-1). The limit of detection and the limit of quantification of the procedure were 0.0066 microg mL(-1) and 0.022 microg mL(-1), respectively. The retention time was 2.5 min for zalcitabine and 3.5 min for the internal standard. No interferences from tablet additives were observed and analysing tablets containing zalcitabine proved the applicability of the method. This method was also applied for the determination of zalcitabine in spiked human serum samples.

Determination of olsalazine sodium in pharmaceuticals by differential pulse voltammetry.

The electrochemical oxidation of olsalazine sodium was investigated by cyclic, linear sweep, differential pulse and square wave voltammetry using glassy carbon disc electrode in different buffer systems. Best results were obtained for the determination of olsalazine using the differential pulse voltammetric technique in phosphate buffer at pH 7.0. The electroactive species exhibits a diffusion-controlled voltammetric wave and its differential pulse peak current shows a linear dependence on olsalazine concentration in the range between 2 x 10(-6) M and 2 x 10(-4) M. This relationship has been applied to the determination of olsalazine in commercial capsule dosage forms. The recovery study shows good accuracy and precision for the assay developed. A UV spectrophotometric assay is also reported for comparison.

Anodic oxidation of etodolac and its square wave and differential pulse voltammetric determination in pharmaceuticals and human serum.

A voltammetric study of the oxidation of etodolac has been carried out at the glassy carbon electrode. The electrochemical oxidation of etodolac was investigated by cyclic, linear sweep, differential pulse and square wave voltammetry using glassy carbon electrode. Different parameters were tested to optimize the conditions for the determination of etodolac. The dependence of intensities of currents and potentials on pH, concentration, scan rate, nature of the buffer was investigated. For analytical purposes, a very well resolved diffusion controlled voltammetric peak was obtained in Britton-Robinson buffer at pH 2.15 for differential pulse and square wave voltammetric techniques. The linear response was obtained in the ranges of 2.10(-6)-8.10(-5) M with a detection limit of 6.8x10(-7) and 6x10(-6)-8x10(-5) M with a detection limit of 1.1x10(-6) M for differential pulse and square wave voltammetric techniques, respectively. Based on this study, simple, rapid, selective and sensitive two voltammetric methods were developed for the determination of the etodolac in tablet dosage form and human serum.

Simultaneous determination of melatonin and pyridoxine in tablet formulations by differential pulse voltammetry.

A method has been developed for the simultaneous determination of melatonin (MT) and pyridoxine hydrochloride (PY) in pharmaceutical dosage forms by differential pulse voltammetry, based on the oxidation of both drugs at a glassy carbon electrode. Cyclic and linear scan voltammetry were used to examine the influence of pH, nature of the buffer, scan rate and concentration. The results in 0.5 M H2SO4 with 20% methanol allowed a method to be developed for the determination of MT and PY simultaneously and in the presence of each other in the ranges 2 x 10(-5)-8 x 10(-5) and 2 x 10(-5)-4 x 10(-4) M, with the detection limits of 5.86 x 10(-6) and 2.45 x 10(-6) M, respectively. The proposed method was successfully applied to the commercial tablets containing this drug combination without any interference by the excipients.

Intraoperative management of the thyroid gland in laryngeal cancer surgery.

OBJECTIVE: To determine if it is necessary to perform a hemithyroidectomy routinely with all total laryngectomies or if it should be reserved for selected cases. DESIGN: A retrospective analysis of 215 cases who had been operated on due to laryngeal cancer in our clinic between 1985 and 1999. SETTING: In only 182 cases, hemithyroidectomy and isthmectomy were performed together with laryngeal surgery. Of these, 98% were male. Their ages ranged between 42 and 70 years. The tumour was located in the supraglottic region in 93 (51%) and in the glottic region in 24 (13%) cases. In 65 cases (36%), the tumour was transglottic. Twenty cases of transglottic tumours (31%) and 3 cases of glottic tumours (12.5%) were found to have subglottic extension. METHODS: Total laryngectomy with unilateral or bilateral neck dissection and hemithyroidectomy on the tumour side plus isthmectomy were performed on all patients. On the pathologic specimens, subglottic extension was measured anteriorly and posteriorly from the free edges of the vocal cords. The specimens were stained with hematoxylin and eosin and examined under a light microscope. MAIN OUTCOME MEASURES: With glottic and transglottic carcinomas, the need for thyroidectomy may be based on the intraoperative assessment of the thyroid gland. In subglottic carcinomas, a hemithyroidectomy should routinely be performed. There may be no need to perform thyroidectomy in all total laryngectomy cases. RESULTS: The thyroid gland was invaded by squamous cell carcinoma in only 2 cases (1%). Both of these cases were transglottic tumours staged as T3 and T4 and had a subglottic extension more than 1 cm. CONCLUSIONS: We recommend routine hemithyroidectomy and isthmectomy during total laryngectomy only in cases with subglottic extensions more than 1 cm or thyroid cartilage invasion with tumour. In the other cases, assessment of extralaryngeal invasion and thyroid gland invasion by the tumour will determine whether thyroidectomy should be performed.

Study on electrooxidation of cefadroxil monohydrate and its determination by differential pulse voltammetry.

In this work electrooxidation of cefadroxil monohydrate was investigated using a glassy carbon electrode depending on pH and supporting electrolyte. It was shown that the direct determination of the substance from capsules and in oral suspension could be made by differential pulse voltammetry (DPV). UV and first derivative UV spectrophotometric methods are also proposed as comparative methods.