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Biomedical subjects

M Ulgen

Publications and source records attributed to M Ulgen.

At least 19 recordsLinked to original sources
PubMed2006

Urinary tract infections due to Mycoplasma canis in dogs.

Urine samples were obtained from 100 dogs with symptoms of lower urinary tract disease by cystocentesis and were examined for mycoplasmas. Urinalysis, haematological and biochemical analyses were also performed. Bacteria were isolated from urine in 41 of 100 dogs; Mycoplasma canis was isolated from four of 100 (4%) urine samples and three were pure culture. Selective mycoplasma media were used for isolation. In growth inhibition test, propagation of the four M. canis isolates was inhibited by their specific hyperimmune sera and there was no cross reactivity between isolates and hyperimmune sera of other mycoplasmas. Dogs in which M. canis was isolated were azotemic. All dogs were treated with enrofloxacin, furosemide, and supportive therapy (fluid therapy, ascorbic acid). In all animals, clinical improvements were observed after treatment.

Animals↗
PubMed2006

An high performance liquid chromatographic method for the quantification of cotinine in the urine of preschool children.

Tobacco smoke exposure is an important and preventable cause of morbidity among children. Enviromental tobacco smoke (ETS) increases respiratory symptoms and disease and also decreases lung function in children who live in a household with at least one smoker. We have developed a simple and reliable HPLC method with diode array dedection to determine the urine concentrations of cotinine in children aged 3 to 6 years, exposed to ETS. The assay involved a liquid-liquid extraction with chloroform. The HPLC method utilized a Chromasil C18 column (150 mm x 4.6 mm i.d.) and an isocratic mobile phase of phosphate buffer: acetonitrile (83:17 v/v, 0.02 M containing 0.1% triethylamine, adjusted to pH 6.72 with orthophosphoric acid), at a flow rate of 0.7 ml min(-1). The detection was performed at 260 nm and the total analysis time of analysis was less than 15 min. Linearity ranged from 0 to 80 microg L(-1); correlation coefficients (r2) for calibration curves were greater than 0.99. With 2 mL of urine for extraction, the limit of detection was 0.1 microg L(-1). The mean extraction ratio of cotinine was 88.78%. This analytical method is suitable for the determination of cotinine levels in a large number of urine samples.

Calibration↗
PubMed1999

In vitro hepatic microsomal metabolism of N-benzyl-N-methylaniline.

In the present study, the in vitro microsomal metabolism of a tertiary aniline, N-benzyl-N-methylaniline (NBNMA) was studied to determine whether this compound produces an amide derivative (benzoyl) together with N-dealkylation and C- and N-oxidation products as metabolites. The preparations of the corresponding potential metabolites were undertaken and were separated using TLC and HPLC. Incubations were performed using rat microsomal preparations fortified with NADPH. The substrate and its potential metabolites were extracted into dichloromethane in the presence of NaCl and examined by TLC and HPLC-UV. The results indicated that NBNMA did not produce the corresponding amide (benzoyl derivative) or N-oxide metabolite but was dealkylated to the corresponding secondary amine. Two p-hydroxylated phenolic metabolites were also observed. These findings support the concept that nitrones are essential intermediate metabolites for the formation of amides from secondary aromatic amines (chemical rearrangement to amide via an oxaziridine intermediate). The carbinolamine produced from NBNMA does not seem stable enough to allow further oxidation to the amide and therefore this intermediate is broken down to the dealkylation products. N-Dealkylations and p-hydroxylations are major metabolic reactions following in vitro hepatic microsomal metabolism of the benzylic tertiary aniline, NBNMA.

Amides↗
PubMed1999

The in vitro hepatic metabolism of 1-phenyl-2-(2-benzothiazolinone-3-yl)ethanone and their reduced derivatives.

The in vitro hepatic microsomal metabolism of 1-phenyl-2-(2-benzothiazolinone-3-yl)ethanone (I) and (+/-)-1-Phenyl-2-(2-benzothiazolinone-3-yl)ethanol (II) was studied using both rat microsomal preparations and soluble fractions fortified with NADPH. These two substrates and their potential dealkylation metabolite 2-benzothiazolinone were synthesized and their structures were elucidated by spectral methods. The results showed that (I) was metabolised to (II), the corresponding alcohol by reduction. More alcohol metabolite was observed with microsomes than those obtained with the soluble fractions. No dealkylation of (I) was observed in the experiments using both microsomes and soluble fractions. (II) was metabolised to (I), the corresponding ketone by oxidation. However, compared to the metabolism of (I), more ketone metabolite was observed with soluble fractions than microsomes. (II) was also dealkylated to (III) with only soluble fractions but no dealkylated metabolites were found in the microsomes. In addition, a common unknown metabolite was observed with each substrates.

Analgesics↗
PubMed1999

The in vitro hepatic microsomal metabolism of 3,5-dimethyl-4-(phenylazo)-(1H)-pyrazole in rats.

The in vitro hepatic microsomal metabolism of 3,5-dimethyl-4-(phenylazo)-(1H)-pyrazole (DMPAP) was studied using washed rat hepatic microsomal preparations fortified with NADPH. The substrate, DMPAP, and its potential metabolites, i.e. the corresponding reduction product, 3,5-dimethyl-4-amino-(1H)-pyrazole (DMAP), and the oxidation product, 3,5-dimethyl-4-(phenylazoxy)-(1H)-pyrazole (DMAPO), were synthesized and their structures elucidated by use of their spectral characteristics. DMPAP and its potential metabolites were then separated using a reverse phase HPLC system consisting of a C18 column and a mobile phase of acetonitrile:water (50:50) at a flow rate of 1 ml/min with UV detection at 254 nm. DMPAP was incubated with rat microsomal preparations, extracted into DCM in the presence of NaCl, and finally evaporated under a stream of nitrogen. The results from HPLC studies showed that DMPAP was metabolised to the corresponding reduction and oxidation products in the presence of NADPH.

Animals↗
PubMed1999

The in vitro hepatic microsomal metabolism of N-benzyladamantanamine in rats.

The metabolism of N-benzyladamantanamine (NBAD) was studied in vitro using rat hepatic microsomal preparations. The substrate and proposed metabolites were synthesized and characterized using spectroscopic techniques and separated using a reverse phase HPLC system. NBAD was incubated with rat microsomal preparations, extracted into DCM in the presence of NaCl and evaporated under a stream of nitrogen. The results from HPLC studies showed that NBAD produced the corresponding nitrone and hydroxylamine. This experiment also revealed that dealkylation occurred. No metabolites were observed which corresponded to authentic amide or oxaziridine. The reactions required a microsomal enzyme source and NADPH as a cofactor. The results indicate that the nitrone observed as a metabolite of NBAD is not an intermediate leading to the formation of an oxaziridine and hence an amide, under careful experimental conditions excluding light.

Amantadine↗
PubMed1999

The in vitro hepatic microsomal metabolism of methyl 2-(2(3H)-benzoxazolone-3-yl)acetate in rats.

The in vitro hepatic microsomal metabolism of methyl 2-(2(3H)-benzoxazolone-3-yl)acetate (I) was studied using hepatic washed rat microsomal preparations fortified with NADPH. The substrate (I) and its potential hydrolytic metabolite 2-(2(3H)-benzoxazolone-3-yl)acetic acid (II) and 2(3H)-benzoxazolone (III), a potential dealkylation metabolite, were separated using a reverse phase HPLC system which consisted of a C18 column and a mobile phase of acetonitrile: 0.02 M phosphate buffer (30:70, final pH 7) at a flow rate of 1 ml/min with UV detection at 254 nm. The substrate (I) was incubated with rat microsomal preparations, extracted into DCM, and finally evaporated under nitrogen. The results from HPLC studies showed that (I) was metabolised to (II) and (III) by rat microsomes in the presence of NADPH.

Acetates↗
PubMed1999

Chemical artifacts in drug metabolism research.

A number of drug metabolism reactions results in artifacts produced by non-enzymatic changes in substrate or metabolite. Substrates and/or their metabolites may either be chemically modified during their metabolism or at any stage of the experimental procedure, i.e. extraction, concentration, separation and storage into breakdown/condensation products. In the present work, the formation and the sources of the chemical artifacts, most of which were previously observed in our laboratories, will be discussed. These will include the chemical formation of amides and oxaziridines from diarylnitrones; diarylnitrones from the corresponding hydroxylamines and the observation of diarylimines formed as a metabonate from debenzylation products during the metabolism of N-benzyl-4-chloraniline and N-(4-chlorobenzyl)-4-chloraniline.

Animals↗
PubMed1998

Synthesis and in vitro microsomal metabolism of 4-ethyl-5-(4-fluorophenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione and its potential metabolites.

Although most triazoline-3-thione derivatives (cyclic thiosemicarbazides) are important compounds possessing some biological and pharmacological activities, no literature was found showing their metabolic reactions with hepatic microsomal preparations. We, therefore, planned to study the in vitro microsomal metabolism of a prototype, 4-ethyl-5-(4-fluorophenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (A). The substrate (A) and its potential metabolites i.e. the corresponding dealkylation (A1), desulphuration (A2) and S-oxidation (A3) products were synthesized and characterized by spectral methods. The substrate and its potential metabolites were separated by a reverse phase HPLC. A was incubated with rat microsomal preparations fortified with NADPH and extracted into DCM; concentrated under a stream of N2 at 20 degrees C and analyzed by HPLC. The results indicated that A was metabolically inert and failed to produce the corresponding desulphuration (triazole-3-one) and S-oxidation (sulphenic acid) metabolites which would lead to pharmacological and toxicological alterations compared to the parent molecule. However, a small amount of dealkylated product (A1) was observed as a metabolite together with two unidentified metabolites.

Animals↗
PubMed1997

The influence of the masticatory hypofunction on the craniofacial growth and development in rats.

In the present study, one masticatory hypofunction group and one normal function group were comprised of growing Wistar albino rats. The influence of the masticatory hypofunction on the growth and development of the craniofacial skeleton in rats was examined. The normal function group received the diet in the form of hard pellets, but the hypofunction group was fed powdered food. To avoid growth reduction because of nutritional deficiency, the animals were fed ad libitum, diet and water. At the end of the experimental period, the 90-day-old adult animals were killed and the direct anthropometric cranial, maxillary, and mandibular measurements were made on the skulls. The significant results can be summarized as follows: Total skull length, total anterior face height, lower anterior face height, ramus mandibula height, corpus mandibula height, premaxillary length, and maxillary width have been reduced but foramen incisivum width has been increased. This study showed that there is no significant effect of the masticatory hypofunction on the cranial growth and development in the growing rats, but that masticatory hypofunction affected the growth and development of the maxillofacial skeleton.

Animal Nutritional Physiological Phenomena↗
PubMed1997

Psychosocial aspects and psychiatric disorders in children with thalassemia major.

beta-thalassemia major (TM), a chronic, genetically determined hematological disorder, has received little investigation on the psychological aspects of the disease and the psychosocial adjustment of patients with this anemia. In the present study, the aim was to assess the mental capacity, self-image, hopelessness and anxiety displayed by children who suffered from TM, and to investigate the existence of psychiatric disorders in these children. Twenty-five children (16 boys and 9 girls) with TM, 12.0-19.6 years old, from the Hematology Unit of the Department of Pediatrics at the SSK Tepecik Teaching Hospital, were included in the study. Fifteen healthy cases matched for age, sex and socio-economic status were used as controls. The Wechsler Intelligence Scale for Children (or Wechsler Adult Intelligence Scale), Offer Self-Image Questionnaire, Beck Hopelessness Scale, Trait Anxiety Inventory, Symptom Check List (revised) and the Family Assessment Device were performed on all patients. Then, the patients were evaluated for a psychiatric disorder by a psychiatrist (according to the diagnostic criteria of the Diagnostic and Statistical Manual IV of the American Psychiatric Association). The results for the patients and control cases were compared statistically using Mann-Whitney and Kruskal-Wallis tests. Self-image was found to be significantly lower in patients with TM than in control cases (P < 0.01). Hopelessness and Trait-Anxiety scores were determined to be significantly higher in patients with TM than in control cases (P < 0.01 and P < 0.05, respectively). Eighty percent of the patients with TM have had at least one psychiatric disorder. As a result, the study showed that most of the patients with TM had severe psychosocial problems. Relying on these data, it was concluded that medical therapy of these patients should be supported with psychological aid and psychiatric treatment.

Adolescent↗
PubMed1997

Microsomal metabolism of N-benzyl-N-ethylaniline and N-benzyl-N-ethyl-p-toluidine.

The in vitro hepatic microsomal metabolism of two tertiary anilines, N-benzyl-N-ethylaniline (NBNEA) and N-benzyl-N-ethyl-p-toluidine (NBNEPT), was examined in order to determine whether these compounds produce amide derivatives (benzoyl or acetyl) in addition to N-dealkylation and N-oxidation products as metabolites. The preparation of these tertiary anilines and their corresponding potential metabolites was undertaken. The amines and metabolites were separated using TLC and HPLC. Incubations were performed using hamster microsomal preparations fortified with NADPH. The substrates and their potential metabolites were extracted into dichloromethane and examined by TLC and HPLC. The metabolic process of particular interest was the formation of amides from NBNEA and NBNEPT. The results from these experiments indicated that neither tertiary aniline (NBNEA and NBNEPT) produced amide (acetyl or benzoyl) or N-oxide metabolites. These substrates were dealkylated to the corresponding secondary amines via debenzylation and de-ethylation. Uncharacterised metabolites observed with substrates are proposed to be phenolic (for NBNEA) and hydroxymethyl (for NBNEPT). These findings support the concept that: nitrones are essential intermediates for the formation of amides from secondary aromatic amines (chemical rearrangement to amide via an oxaziridine intermediate); carbinolamines produced by NBNEA and NBNEPT are not stable enough to allow further oxidation to amides and therefore these intermediates are broken down to dealkylated products. The results are discussed in relation to the mechanism of metabolic amide formation from amines.

Aniline Compounds↗
PubMed1997

In vitro microsomal metabolic studies on secondary aromatic amides.

Previous studies showed that amides are metabolites arising from certain secondary aromatic amines. However, some analogue amines did not lead to the formation of the corresponding amides when metabolised under identical conditions. We, therefore, wished to establish the factors preventing detection of amides. In the present study, we thought that amide detection as metabolites from secondary anilines may depend on the hydrolytic rate of the corresponding amide. We studied the in vitro hepatic microsomal metabolism of four aromatic amides i.e. N-(4-nitrobenzoyl)aniline (N4NBZA), N-benzoyl-4-nitroaniline (NBZ4NA), N-benzoylaniline (NBZA) and N-benzoyl-2,4,6-trimethylaniline (NBZTMA) which were (or not) detected following microsomal metabolism of secondary anilines in previous studies. Following the preparation, characterisation and separation of substrates and potential metabolites, incubations were carried out using rabbit microsomal preparations fortified with NADPH. The substrates and potential metabolites were extracted into dichloromethane and analysed by TLC, HPLC and UV. The results indicated that both steric and electronic factors may influence hydrolysis of amides. Three amides i.e. N4NBZA, NBZ4NA and NBZA yielded hydrolytic metabolites, whereas, NBZTMA did not. Para hydroxylated metabolites were also detected from N4NBZA and NBZA. These observations support the concept that one reason for not detecting amides as metabolites from secondary anilines in previous studies could be due to their rapid hydrolysis to the corresponding primary amines.

Amides↗
PubMed1996

The effects of the FR-3 appliance on the transversal dimension.

The purpose of this study was to examine the effects of the FR-3 appliance on the transversal dimension. The treatment group consisted of 20 patients with Class III malocclusion, who were treated with the FR-3 appliance. The control group consisted of 19 patients with Class III malocclusion. Posteroanterior radiographs and study models were taken at the beginning and at the end of the study in both groups. The results suggested that although FR-3 appliance therapy does not increase the width of the nasal cavity and does not stimulate the growth of the maxillary apical base, it does cause an increase in the intermolar and interpremolar distances in the maxilla both in the dental and the alveolar areas.

Alveolar Process↗
PubMed1996

The failure of substrate pKa to influence the microsomal formation of amides from N-benzylamines: the microsomal metabolism of N-benzyl pyrrolidine, N-benzyl carbazole and N-acetyl-N-benzyl-4-methylaniline.

The in-vitro hepatic microsomal metabolism of N-benzylpyrrolidine (NBP), N-benzylcarbazole (NBC) and N-acetyl-N-benzyl-4-methylaniline (NANBMA) has been studied, using hamster microsomal preparations, to establish whether the corresponding amide is formed. Amide formation was not observed with any of the substrates utilized, although several metabolic products were detected by HPLC with UV detection. These included the oxidative debenzylation products (for all substrates), ring hydroxylated products (for NBC) and a lactam metabolite (for NBP). The results support the concept that the metabolic conversion of benzylic amines to the corresponding amide involves an N-oxidative step.

Aniline Compounds↗
PubMed1995

The effects of Frankel's function regulator (FR-4) therapy on the treatment of Angle Class I skeletal anterior open bite malocclusion.

The present study attempts to evaluate cephalometrically the effects of Fränkel's function regulator (FR-4) appliance on the treatment of Angle Class I skeletal anterior open bite malocclusion. Forty Turkish children (26 girls and 14 boys), with Angle Class I skeletal anterior open bite, were randomly divided into two groups of 20 (13 girls and 7 boys). Patients who had not undergone treatment served as the control group, whereas a second group was treated with lip-seal training and the FR-4 appliance. Chronologic mean decimal age at initial period of the investigation was 8.7 years in the treated group, and 8.9 years in the control group. Treatment and observation periods were 2 years. Investigation was carried out on lateral cephalograms taken before and after the study period. The results indicate that a spontaneous downward and backward growth direction of the mandible observed in the control group could be changed to a upward and forward direction by FR-4 therapy. The skeletal anterior open bite was successfully corrected through upward and forward mandibular rotation.

Cephalometry↗
PubMed1995

Chemical and metabolic studies on N-benzyl-tert-butylamine and its potential metabolites.

The metabolism of N-benzyl-tert-butylamine was studied in vitro using male hamster hepatic microsomal preparations. This substrate produced the corresponding nitrone, benzaldehyde and an uncharacterised metabolite. No metabolites were detected which corresponded to either authentic amide or oxaziridine. The results indicate that the nitrone observed as a metabolite in this experiment is not an intermediate leading to the formation of an oxaziridine and hence an amide, under careful experimental conditions excluding light.

Animals↗