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Biomedical subjects

I Yalcin

Publications and source records attributed to I Yalcin.

10 recordsLinked to original sources
PubMed2006

Synthesis, antimicrobial activity and QSARs of new benzoxazine-3-ones.

New ethyl 3,4-dihydro-3-oxo-4,6,7-trisubstituted-2H-1,4-benzoxazine-2-acetate derivatives were synthesized and their structures were elucidated by IR, (1)H NMR and mass spectral data. Antimicrobial activity of the compounds was investigated by using the method of twofold serial dilution technique against different Gram-positive, Gram-negative bacteria and some Candida species in comparison to standard drugs. Microbiological results indicated that the synthesized compounds possessed a broad spectrum of activity having MIC values of 6.25-100 micro g/ml against the tested microorganisms. The QSAR analysis of a set of these compounds tested for growth inhibitory activity against Candida krusei was performed by using the computer-assisted multiple regression procedure. The activity contributions for substituent effects of these compounds were determined from the correlation equation for predictions of the lead optimization.

Anti-Bacterial Agents↗
PubMed2006

3D-QSAR study on heterocyclic topoisomerase II inhibitors using CoMSIA.

Selective topoisomerase II (Topo II) inhibitors have interested to a great extent for the design of new antitumoral compounds in recent years. Comparative molecular similarity indices analysis (CoMSIA) was performed on a series of previously synthesized benzoxazole, benzimidazole, and oxazolo(4,5-b)pyridine derivatives as eukaryotic Topo II inhibitors. A training set of 16 heterocyclic compounds was used to establish the CoMSIA model. They were constructed and geometrically optimized using SYBYL v7.0. The predictive ability of the model was assessed using a test set of 7 compounds. The best model has demonstrated a good fit having r2 value of 0.968 and cross-validated coefficient q2 value as 0.562 including steric and hydrophobic fields. The hydrophobic interactions showed a dominant role for increasing Topo II inhibitor activity and hydrophilic substituent was found more important than hydrophobic one on the 5 or 6 position of benzazole moiety. The model obtained from the present study can be useful for the modification and/or evaluation of the development of new Topo II inhibitors as potential antitumor compounds.

Benzimidazoles↗
PubMed2006

A study on the antioxidant activities of some new benzazole derivatives.

The in vitro antioxidant properties of some new benzazole derivatives (1-10) such as benzoxazoles, benzimidazoles, and benzothiazoles were determined by their effects on the rat liver microsomal NADPH-dependent lipid peroxidation (LP) level, the scavenging of superoxide anion and the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). Compounds 1, 2, 4 and 6, showed potent scavenging effect on superoxide radical at 10(-3) M. Compound 8, 5-nitro-2-(phenoxymethyl)benzimidazole, strongly inhibited lipid peroxidation at 10(-3) M concentration.

Animals↗
PubMed2006

Neuropeptides in psychiatric diseases: an overview with a particular focus on depression and anxiety disorders.

This paper aimed at reviewing the involvement of neuropeptides in various psychiatric diseases, particularly in depression, and anxiety disorders. General features of neuropeptides are first described, including the history of their discovery, their definition, classification, biosynthesis, transport, release, inactivation, as well as their interaction with specific neuronal receptors. The differences with classical neurotransmitters are mentioned, as well as the different patterns of co-transmission. Finally, different mechanisms, both at the cellular and at the systemic level, are proposed that may explain the involvement of these molecules in various psychiatric diseases. Indeed, at the cellular level, a neuropeptide can be involved in a psychiatric disease, either because it is co-localized with a classical neurotransmitter involved in a disease, or because the neuropeptide-containing neuron projects on a target neuron involved in the disease. At the systemic level, a neuropeptide can play a direct role in the expression of a symptom of the disease. This is illustrated by different examples.

Animals↗
PubMed2004

Duloxetine vs placebo in the treatment of stress urinary incontinence: a four-continent randomized clinical trial.

OBJECTIVES: To further assess, in a phase 3 study, treatment with duloxetine for women with stress urinary incontinence (SUI) in other geographical regions, including Argentina, Australia, Brazil, Finland, Poland, South Africa and Spain, as previous trials in North America and Europe provided evidence for the safety and efficacy of duloxetine as a pharmacological treatment for SUI in women. PATIENTS AND METHODS: The study included 458 women aged 27-79 years enrolled in a double-blind, placebo-controlled trial. The patients with predominantly SUI were identified using a validated clinical algorithm. They were randomly assigned to receive placebo (231) or duloxetine 40 mg twice daily (227) for 12 weeks. The primary outcome variables included the incontinence episode frequency (IEF) and the Incontinence Quality of Life (I-QOL) questionnaire. Van Elteren's test was used to analyse the percentage changes in IEF where the stratification variable was weekly baseline IEF (IEF < 14 and > or = 14). Analysis of covariance was used to analyse I-QOL scores. RESULTS: The mean baseline IEF was 18.4/week; 55% of patients had a baseline IEF of > or = 14. There was a significantly greater median decrease in IEF with duloxetine with placebo (54% vs 40%, P = 0.05), with comparable significant improvements in quality of life (I-QOL score increases of 10.3 vs 6.4, P = 0.007). The improvements with duloxetine were associated with significantly greater increases in voiding intervals than with placebo (20.4 vs 8.5 min, P < 0.001). The placebo response was 10.7% and 12.5% higher than those reported in two European and North American phase 3 trials. This may have been related to more patients being naïve for incontinence management in the current trial. Discontinuation rates for adverse events were 1.7% for placebo and 17.2% for duloxetine (P < 0.001), with nausea being the most common reason for discontinuation (3.1%); it was the most common adverse event with duloxetine, but was mild or moderate in most (81%), did not worsen in any patient and resolved within 7 days in 60% and within 1 month in 86% of continuing patients; 88% of women who experienced nausea while taking duloxetine completed the trial. CONCLUSIONS: These results show improvements in incontinence and quality of life with duloxetine 40 mg twice daily for 12 weeks that are in keeping with those reported in two other recently completed phase 3 trials in Europe and North America.

Adrenergic Uptake Inhibitors↗
PubMed2000

The stability of the factor structure of the General Health Questionnaire.

BACKGROUND: Different versions of the General Health Questionnaire (GHQ), including the GHQ-12 and GHQ-28 have been subjected to factor analysis in a variety of countries. The World Health Organization study of psychological disorders in general health care offered the opportunity to investigate the factor structure of both GHQ versions in 15 different centres. METHODS: The factor structures of the GHQ-12 and GHQ-28 extracted by principal component analysis were compared in participating centres. The GHQ-12 was completed by 26,120 patients and 5,273 patients completed the GHQ-28. The factor structure of the GHQ-28 found in Manchester in this study was compared with that found in the earlier study in 1979. RESULTS: For the GHQ-12, substantial factor variation between centres was found. After rotation, two factors expressing depression and social dysfunction could be identified. For the GHQ-28, factor variance was less. In general, the original C (social dysfunction) and D (depression) scales of the GHQ-28 were more stable than the A (somatic symptoms) and B (anxiety) scales. Multiple cross-loadings occurred in both versions of the GHQ suggesting correlation of the extracted factors. In Manchester, the factor structure of the GHQ had changed since its development. Validity as a case detector was not affected by factor variance. CONCLUSIONS: These findings confirm that despite factor variation for the GHQ-12, two domains, depression and social dysfunction, appear across the 15 centres. In the scaled GHQ-28, two of the scales were remarkably robust between the centres. The cross-correlation between the other two subscales, probably reflects the strength of the relationship between anxiety and somatic symptoms existing in different locations.

Asia↗
PubMed1999

Quality of life of women with urinary incontinence: further development of the incontinence quality of life instrument (I-QOL)

OBJECTIVES: To report on the further development of the Incontinence Quality of Life Instrument (I-QOL), a self-report quality of life measure specific to urinary incontinence (UI), including its measurement model, responsiveness, and effect size. METHODS: Incontinent female patients (141 with stress, 147 with mixed UI) completed the I-QOL and comparative measures at screening, pretreatment, and four subsequent follow-up visits during participation in a multicenter, double-blind, placebo-controlled, randomized trial assessing the efficacy of duloxetine. Psychometric testing followed standardized procedures. RESULTS: Factor analysis confirmed an overall score and three subscale scores (avoidance and limiting behaviors, psychosocial impacts, and social embarrassment). All scores were internally consistent (alpha = 0.87 to 0.93) and reproducible (ICC = 0.87 to 0.91). The pattern of previously reported correlations with the Short-Form 36-item Health Survey and Psychological Well-Being Schedule were confirmed. Responsiveness statistics using changes in the independent measures of stress test pad weight, number of incontinent episodes, and patient global impression of improvement ranged from 0.4 to 0.8. Minimally important changes ranged from 2% to 5% in association with these measures and effect sizes. CONCLUSIONS: In a clinical trial, the I-QOL proved to be valid, reproducible, and responsive to treatment for UI in women.

Adolescent↗
PubMed1998

In vitro chromosomal radiosensitivity in common variable immune deficiency.

Common variable immune deficiency (CVID) is characterized by low immunoglobulin levels and recurrent infections in patients with a period of normal immune function several years after birth. It is associated with diarrhea, malabsorption, bronchiectasis, and lymphoreticular malignancies. Radiation-induced chromosome instability may contribute to the high degree of susceptibility to neoplasia. Peripheral blood lymphocyte cultures were obtained from six patients with CVID and the healthy control group matched by age and sex. The groups did not differ in the frequency of spontaneous chromosome aberrations. After exposure to X-ray radiation, mitotic indices were found to be significantly low and incidence of chromosomal alterations were high in the CVID group. We conclude that chromosomes of cells from patients with CVID are significantly more radiosensitive than those of controls. Thus these patients must be protected from unnecessary X-ray examinations and in case of radiosensitive tumour, the dose of irradiation should be carefully monitored.

Adolescent↗
PubMed1984

In vitro investigations in asthmatic children undergoing hyposensitization with tyrosine-adsorbed Dermatophagoides pteronyssinus antigen.

Successful hyposensitization to Dermatophagoides pteronyssinus in perennial childhood asthma was associated with a slight mean rise of serum IgG antibody to the mite antigen in contrast to a placebo group in whom this antibody fell slightly. No relationship was detected between the effect on asthma and the magnitude of this change. Nor was there any consistent effect on IgE or IgA antibody. There was a wide range of total serum IgE and IgE, IgG and IgA antibody to D. pteronyssinus before treatment; this level did not predict the effect of treatment. Some patients lacked IgA antibody. IgE antibody to timothy grass pollen was raised in some but not others. These levels did not change systematically during the study and improvement occurred in those who had this antibody as well as IgE antibody to D. pteronyssinus. IgG and IgE antibodies to D. pteronyssinus were significantly correlated in the pre-treatment samples. Lymphocyte thymidine uptake was lower after 8 weeks of treatment than in the control group, not only after stimulus with D. pteronyssinus antigen, in vitro, but also with antigen from Candida albicans. This was not a serum effect. The late bronchial provocation response was lost only in those with serum IgA less than the log mean for age.

Adolescent↗