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Featured researches published by A. L. Bas.


Aaps Pharmscitech | 2007

Chitosan film containing fucoidan as a wound dressing for dermal burn healing: preparation and in vitro/in vivo evaluation.

Ali Demir Sezer; F. Hatipoglu; Erdal Cevher; Z. Ogurtan; A. L. Bas; Jülide Akbuğa

The aim of this study was to develop chitosan film containing fucoidan and to investigate its suitability for the treatment of dermal burns on rabbits. Porous films, thickness between 29.7 and 269.0 μm, were obtained by the solvent dropping method. Water vapor permeability (3.3–16.6/0.1 g), the swelling (0.67–1.77 g/g), tensile strength (7.1–45.8 N), and bioadhesion (0.076–1.771 mJ/cm2) of the films were determined. The thinnest films were obtained with the lowest chitosan concentration (P<.05). The water absorption capacity of the films sharply increased with the freeze-drying technique. The film having the thickness of 29.7 μm showed the highest amount of moisture permeability (16.6 g/0.1 g). Higher chitosan concentration significantly increased tensile strength of the films (P<.05). Using higher concentration of lactic acid made films more elastic and applicable, and these films were selected for in vivo studies. Seven adult male New Zealand white rabbits were used for the evaluation of the films on superficial dermal burns. Biopsy samples were taken at 7, 14, and 21 days after wounding, and each wound site was examined macroscopically and histopathologically. After 7 days treatment, fibroplasia and scar were observed on wounds treated with fucoidan-chitosan film. The best regenerated dermal papillary formation, best reepithelization, and the fastest closure of wounds were found in the fucoidan-chitosan film treatment group after 14 days compared with other treatment and control groups. It can be concluded that fucoidan-chitosan films might be a potential treatment system for dermal burns and that changing formulation variables can modulate the characterizations of the films.


Journal of Liposome Research | 2004

Encapsulation of enrofloxacin in liposomes I: preparation and in vitro characterization of LUV.

Ali Demir Sezer; A. L. Bas; Jülide Akbuğa

Liposomes are effectively used in the treatment of microbial infections. Higher cellular uptake has been reported when antibiotics are encapsulated in liposomes. In this study, enrofloxacin (ENF) was encapsulated in large unilamellar vesicles (LUVs) and the effects of formulation variables on the liposome characteristics were investigated. Liposomes were prepared using dry lipid film method. A number of variables such as molar ratios of phospholipid (DPPC; DL‐α‐phosphatidylcholine dipalmitoyl), cholesterol, ENF and amount of α‐tocopherol and the volumes of internal (chloroform) and external phases [phosphate buffered saline PBS (pH 7.4)] were studied. In vitro characterization of the liposomes including the encapsulation capacity, size and drug release properties were carried out. Using of this method, spherical LUV liposomes with high drug content could be produced. Particle size of liposomes changed between 3.12 and 4.95 µm. The molar ratios of DPPC, cholesterol and ENF affected the size of the liposome (p < 0.05). The drug encapsulation capacities were high and changed between 37.1% and 79.5%. The highest ENF encapsulation was obtained with the highest cholesterol content. An increase in the drug encapsulation capacity of the liposome was found with increasing molar ratios of DPPC, cholesterol and ENF (p < 0.05). Furthermore, the release of ENF from the liposomes decreased as the molar ratios of DPPC, cholesterol and ENF increased (p < 0.05). In conclusion, a convenient colloidal carrier for the controlled release of ENF can be prepared by changing the formulation parameters of LUVs.


British Poultry Science | 2000

Effects of continuous supplementations of ascorbic acid, aspirin, vitamin E and selenium on some haematological parameters and serum superoxide dismutase level in broiler chickens.

Bunyamin Tras; F Inal; A. L. Bas

1. This study was conducted using male broiler chickens to determine the effects of ascorbic acid, aspirin, ascorbic acid+aspirin, vitamin E+selenium and ascorbic acid+aspirin+vitamin E+selenium supplementations on haematological parameters and serum superoxide dismutase concentration. 2. One hundred and twenty day-old male Hubbunt broiler chicks were randomly divided into 6 experimental groups of 20 chicks each and placed in different pens. Groups 2, 3, 4, 5 and 6 were given a diet supplemented with ascorbic acid, aspirin (in water), ascorbic acid+aspirin, vitamin E+selenium and ascorbic acid+aspirin+vitamin E+selenium, respectively for 45 d while group 1 was given a commercial broiler diet. 3. There was no significant effect of ascorbic acid, aspirin, ascorbic acid+aspirin, vitamin E+selenium supplementations on any of the haematological parameters (red blood cell, haemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin concentration, mean corpuscular haemoglobin) in broilers but ascorbic acid+aspirin+vitamin E+selenium supplementation significantly decreased the white blood cell counts. 4. In addition to this, ascorbic acid, aspirin, ascorbic acid+aspirin and ascorbic acid+aspirin+vitamin E+selenium supplementations had no significant effect on the serum superoxide dismutase level, but vitamin E+selenium supplementation increased the serum superoxide dismutase level.


International Journal of Endocrinology | 2012

Nerium oleander Distillate Improves Fat and Glucose Metabolism in High-Fat Diet-Fed Streptozotocin-Induced Diabetic Rats

A. L. Bas; Sule Demirci; Nuray Yazihan; Kamil Uney; Ezgi Ermis Kaya

Diabetes was induced by intraperitoneal injection of streptozotocin (35 mg/kg bw) in all rats of five groups after being fed for 2 weeks high-fat diet. Type 2 diabetic Nerium-oleander- (NO-) administered groups received the NO distillate at a dose of 3.75, 37.5, and 375 μg/0.5 mL of distilled water (NO-0.1, NO-1, NO-10, resp.); positive control group had 0.6 mg glibenclamide/kg bw/d by gavage daily for 12 weeks. Type 2 diabetic negative control group had no treatment. NO distillate administration reduced fasting blood glucose, HbA1c, insulin resistance, total cholesterol, low density lipoprotein, atherogenic index, triglyceride-HDL ratio, insulin, and leptin levels. Improved beta cell function and HDL concentration were observed by NO usage. HDL percentage in total cholesterol of all NO groups was similar to healthy control. NO-10 distillate enhanced mRNA expressions of peroxisome proliferator-activated-receptor- (PPAR-) α, β, and γ in adipose tissue and PPAR-α–γ in liver. The findings from both in vivo and in vitro studies suggest that the considerable beneficial effect of NO distillate administration at a dose of 375 μg/0.5 mL of distilled water may offer new approaches to treatment strategies that target both fat and glucose metabolism in type 2 diabetes.


Drug Delivery | 2007

In Vitro Evaluation of Enrofloxacin-Loaded MLV Liposomes

Ali Demir Sezer; Jülide Akbuğa; A. L. Bas

Fluoroquinolones are broad-spectrum antimicrobial agents that seem to reach their intracellular target site (DNA gyrase) in Escherichia coli by means of an uptake process through the outer and inner membranes. Delivery of quinolones with liposomes has many advantages than the free form of the drug. Liposomes may represent an excellent device for improving the selective transport of antibiotics in these respects. In this study, enrofloxacin-loaded multilamellar vesicles (MLVs) were prepared and the effects of formulation variables on the liposome characteristics were investigated. Liposomes were prepared by using the dry lipid film method. A number of variables, such as phospholipid (DL-α -phosphatidylcholine dipalmitoyl), cholesterol, enrofloxacin (ENF), stearylamine, and dicetyl phosphate molar ratios and α -tocopherol amounts, were studied. The liposome size, encapsulation capacity, drug release, stability, and electrophoretic mobility of ENF-loaded liposomes were determined. Using this method, spherical MLVs with high drug content could be produced. Particle size of liposomes changed between 1.63 and 3.31 μ m and liposome size was affected by all formulation variables (p < 0.05) except molar ratio of ENF. MLVs can be used as a carrier system for the controlled release of ENF. The highest encapsulation of ENF amount can be obtained using positively charged SA in the formulation and changing the formulation parameters can vary drug release patterns.


Veterinary Quarterly | 1998

Concentrations of sulfadoxine and trimethoprim in plasma, lymph fluids and some tissues 24 h after intramuscular administration to angora goats

Bunyamin Tras; Muammer Elmas; E. Yazar; A. L. Bas; Ercan Keskin; Z. Daşci

This study was carried out to determine the concentrations of sulfadoxine and trimethoprim in plasma, lymph, and some tissues in goats after administration of a single recommended therapeutic dose. Five healthy, adult Angora goats were used. The drug combination, containing 200 mg sulfadoxine and 40 mg trimethoprim per millilitre, was given as a single IM injection at the recommended dose level, 15 mg/kg body weight for sulfadoxine and 3 mg/kg body weight for trimethoprim. The goats were slaughtered 24 hours after drug administration and samples were taken from liver, bone marrow, pelvic limb muscles, hepatic, thoracic duct, and the pelvic limb lymph fluids for analysis of drug concentrations by HPLC. The concentrations of trimethoprim in bone marrow, liver, pelvic limb muscles, hepatic lymph, the pelvic limb lymph, and thoracic duct lymph were found to be 6, 5, 4, 2, 5 and 15 times higher than those of plasma, respectively. Although the sulfadoxine concentrations in bone marrow, pelvic limb muscles, and liver were 2, 3 and 2 times higher than the plasma concentrations, respectively, the sulfadoxine concentrations in hepatic lymph, the pelvic limb lymph, and thoracic duct lymph were lower than those of plasma. The results show that the trimethoprim concentrations in lymph fluids were quite similar to those in tissues. However, the sulfadoxine concentrations in lymph fluids were different in each tissue.


Veterinary Quarterly | 2001

Pharmacology: Investigation of biochemical and haematological side‐effects of cefquinome in healthy dogs

M. Maden; Bunyamin Tras; A. L. Bas; Muammer Elmas; E. Yazar; F.M. Birdane

Summary In the present study, the effects of cefquinome, a 4 generation cephalosporin, on clinical, biochemical, haemato‐logical, and blood gas variables were investigated. Five healthy dogs were injected with cefquinome (1 mg/kg body weight, IM, daily) for 14 days. Negative effects of cefquinome on clinical, biochemical, and haematological variables were not observed, but it did change some blood gas variables.


Canadian Journal of Physiology and Pharmacology | 2017

The effect of midkine on growth factors and oxidative status in an experimental wound model in diabetic and healthy rats

Burak Dik; A. L. Bas; Nuray Yazihan

Wound healing is important for longevity. Midkine is a cytokine involved in controlling tissue repair and new tissue development, and in regulating inflammation. We investigated the effect of midkine on wound healing in rats. In total, 108 Wistar albino rats were used: 12 as healthy and diabetic controls; 96 were split into 4 groups: healthy, saline treated; healthy, midkine (10 ng/kg, 48 h intervals) treated; diabetic, saline treated; and diabetic, midkine treated. Following wound creation, 6 rats per group were euthanized on days 3, 7, 14, and 28; the wounded skin was removed. Levels of epidermal growth factor (EGF), matrix metalloproteinase-8 (MMP-8), transforming growth factor beta (TGF-β), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and thiobarbituric acid reactive substances (TBARS) were measured. MMP-8 and PDGF levels fluctuated in all groups; TGF-β fluctuated in the diabetic groups and was significantly higher in the HM group than other groups after 14 days. EGF and VEGF levels were increased in the HM group after 3 days. TBARS levels were highest in the diabetic groups. Macroscopically, the midkine-treated groups healed better. Midkine can accelerate wound healing by influencing growth factors and oxidative status in wound tissues.


Pharmaceutical Biology | 2014

Implications from a pharmacogenomic analysis: Nerium oleander leaf distillate supplemented diet regulates cholesterol metabolism in rats

Meltem Demirel Kars; Burcu Asena Odabaşı; Gökhan Kars; Kamil Uney; Yavuz Bagci; A. L. Bas

Abstract Context: Despite the usage of Nerium oleander L. (Apocynaceae) for anticancer studies and traditional remediation, the regulatory effect of N. oleander leaf distillate on cholesterol metabolism is not disclosed sufficiently. Objective: Cholesterol is an important biological molecule and the synthesis rate is regulated by the amount of cholesterol uptake from the diet. The aim of this study was to investigate the regulation of cholesterol metabolism in response to a high-fat diet (HFD) and the effects of N. oleander leaf distillate-supplemented diet (NOHFD) in rats. Materials and methods: Microarray technology was used to clarify the regulation of cholesterol mechanism in HFD and NOHFD-fed rats (375 μg/0.5 mL distilled water applied by gavage). The treatment period was 90 days. Rat liver tissues were used for microarray analysis using the Affymetrix GeneChip Rat Genome platform. Results of groups were statistically analyzed with the Partek 6.6 bioinformatic program. Results: The HFD group exhibited alterations in the expression levels of about 1945 genes with respect to the normal diet (ND) group. The results showed that expression levels of 47 genes were altered related to cholesterol metabolism in HFD and NOHFD groups. The expression levels of seven genes in the NOHFD group were significantly closer to those in the ND group than those of the HFD group. Discussion and conclusion: To conclude, findings suggest that N. oleander leaf distillate-supplemented food has considerable beneficial effects on cholesterol metabolism-related gene expression levels.


Biological & Pharmaceutical Bulletin | 2008

Preparation of fucoidan-chitosan hydrogel and its application as burn healing accelerator on rabbits.

Ali Demir Sezer; Erdal Cevher; F. Hatipoglu; Z. Ogurtan; A. L. Bas; Jülide Akbuğa

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