Nedret Koç

Oral nystatin prophylaxis to prevent invasive candidiasis in Neonatal Intensive Care Unit.

The use of oral nystatin to prevent fungal colonisation and infection in neonates in the Neonatal Intensive Care Unit (NICU) is still an open question and not yet recommended as a standard of care. To determine whether prophylactic oral nystatin results in a decreased incidence of invasive candidiasis in the newborn infants, a total of 3991 infants were divided randomly into two groups. Group A infants (n = 1995), only those neonates who were identified as yeast carriers (oral moniliasis) were treated with oral nystatin. Group B infants, all neonates who were admitted to the unit received oral nystatin, was routinely administered three times a day. Group A was divided into groups A1 and A2 (who were treated only if identified as yeast carriers). Urine and rectal cultures were taken on admission and then weekly thereafter. There were 215 (14.2%), 27 (5.6%) and 36 (1.8%) patients positive for invasive candidiasis in groups A1, A2 and B respectively. Oral nystatin prophylaxis significantly reduced the invasive candidiasis (P = 0.004) in extremely low‐birth weight (ELBW) and very low‐birth weight (VLBW) infants. Prophylactic administration of oral nystatine to the ELBW and VLBW infants results in a decreased risk of invasive candidiasis.

Effects of age and anxiety on learning and memory.

This study aims to investigate the effects of age and anxiety on behavior, learning and memory in rats. Before and after the anxiety and learning tests, locomotor activity, exploratory activity and autonomic functions of the rats were tested in open field area. At the beginning and at the end of behavior tests, urines were collected so as to determine 5-hydroxyindolaceticacid (5-HIAA) levels. Following these tests, rats were anesthetized and their serum corticosteron (CORT) levels were analyzed. After anxiety, except for defecation, all parameters in open field such as line crossing, rearing, sitting and number of grooming were decreased in both young and aged animals. 5-Hydroxyindolaceticacid levels were decreased and serum CORT levels were increased, it is supported that especially the aged rats were much more affected from anxiety compared to the young ones. Elevated T-maze results show that emotional learning did not change while conditioned performance was tested in the closed arm and unconditioned performance was tested in the open arm. Nevertheless, it is observed that aging leaded to extensions in avoidance responses and thus caused difficulty in learning. In water maze test, rats showed higher performance in reaching the platform in repetitive trials; this demonstrates that they have learned by environmental cues. Experimental group had not better performance in reaching the platform according to control group, so this supports that anxiety affects spatial learning. As a conclusion, it could be stated that especially in aged rats, anxiety that is created by elevated T-maze and cat odor and supported with 5-hydroxyindoleacetic acid and serum corticosterone, causes difficulty in emotional and spatial learning.

Renal effects of long-term leptin infusion and preventive role of losartan treatment in rats

BACKGROUND Leptin has direct and indirect effects on renal pathophysiological characteristics. In the present study, the effects of long-term leptin infusion on the renal hemodynamics, renal excretory functions, and the expression of transforming growth factor-beta (TGF-beta), plasma endothelin-1 (ET-1) levels, and preventive effects of the angiotensin II type 1 receptor antagonist, losartan, on these renal changes were evaluated. METHODS The study was performed by using forty Wistar albino rats. On day 0, osmotic mini-pumps filled with leptin or placebo were intraperitoneally placed under sterile conditions. The rats in Group L (Leptin group, n=15) and Group LL (Leptin-losartan group, n=15) were given recombinant murine leptin at a rate of 250 ng per hour for 28 days. Control rats (Group C, n=10) were administered placebo at the same infusion rate. The rats in Group LL were also administered losartan (10 mg kg(-1) d(-1)) perorally for 28 days. On day 28, the rats were placed in metabolic cages, and the food and water intakes were determined, and the urine was collected for 24 h. At the end of the study, systolic blood pressure (SBP), diastolic blood pressure (DBP) were determined directly from the left femoral artery, and renal blood flow (RBF) was recorded indirectly using a laser Doppler flow module. RESULTS Leptin infusion did not produce any changes in systemic arterial blood pressures and urinary flow rate. The rates of creatinine (Cr), sodium (Na), and protein excretions of the animals infused leptin were significantly increased. The urinary Cr and Na excretions were decreased, while the urinary protein excretion was normalized with the losartan treatment. The rats infused leptin had also higher circulating ET-1 levels. ET-1 levels were also reversed to the normal values with the losartan treatment. Renal TGF-beta1 expression was determined immunohistochemically, and it was more prominent in the renal tubules from the rats treated with leptin. The losartan treatment had no effect on renal TGF-beta1 expression. CONCLUSIONS Our results indicate that pathophysiological increases in plasma leptin concentrations cause enhanced renal Na, Cr and protein excretions, and high circulating ET-1 levels. Na and Cr excretions were decreased, while proteinuria and plasma ET-1 levels were normalized by losartan treatment, suggesting that renin-angiotensin system activation may have a role in leptin induced renal changes. TGF-beta1 may have an important role in leptin induced nephropathy.

Prevalence and risk factors of onychomycosis in primary school children living in rural and urban areas in Central Anatolia of Turkey

BACKGROUND Onychomycosis is a world-wide public health concern in children, requiring epidemiological data for different regions for control and prevention. AIM The aim of this study was to evaluate the predominant pathogens and risk factors for onychomycosis in school children living in Kayseri, Turkey. METHODS This study included 8122 school children, aged 5-16 years, living in the rural and urban areas around Kayseri. Onychomycosis was clinically classified as distal and lateral subungual (DLSO), proximal subungual, superficial white, endonyx and totally dystrophic onychomycosis. Nail samples from children with clinically diagnosed onychomycosis were collected, examined by direct microscopy and inoculated for culture study. The demographic features and possible risk factors were recorded and assessed by logistic regression models. RESULTS We clinically diagnosed onychomycosis in 152 out of 8,122 (0.18%) school children. DLSO was the most frequent clinical diagnosis (120/152, 78.9%). Culture-positive onychomycosis was detected in 27/152 (17.7%) children. The prevalence of culture-positive onychomycosis was determined as 0.33%. All culture-positive samples were only from toenails. The onychomycosis causative agents were dermatophytes in 17/27 cases (62.9%), including Trichophyton rubrum 12 (44.4%), Trichophyton mentagrophytes 1 (3.7%), Trichophyton tonsurans 1 (3.7%) and Trichophyton spp. 3 (11.1%) and yeasts in 10/27 cases (37.1%), including Candida glabrata 4 (14.8%), Candida parapsilosis 1 (3.7%), Trichosporon 2 (7.4%) and Rhodotorula 3 (11.1%). Age, fathers occupation, number of siblings and rooms were statistically associated with the frequency of onychomycosis. CONCLUSIONS Although to be prevalence of onychomycosis in school children in central Anatolia of Turkey seems very low degree, pediatric onychomycosis is a growing public health concern all over the world. Children having more siblings or unemployed fathers and children living in small house as well as older children should be examined carefully for onychomycosis.

Saprochaete capitata as an emerging fungus among patients with haematological malignencies

Saprochaete capitata is a very rare pathogen that causes invasive disease particularly in patients with haematological malignancies. We recognised a clustering of S. capitata fungaemia in recent years. So, we report our 6‐year surveillance study of fungaemia among patients with haematological malignancies and haematopoietic stem cell transplant. We performed a retrospective and observational study. Hospitalised patients aged >18 years with haematological malignancies were included in the study. A total of 51 fungaemia episodes of 47 patients were analysed. The characteristics of fungaemia in patients with S. capitata compared to patients with candidemia. Median duration of neutropenia was 21.5 days in patients with S. capitata fungaemia, whereas this duration was significantly shorter in patients with candidemia (8 days). Interval between first and last positive culture was significantly longer in patients with S. capitata fungaemia (P < 0.05). Previous use of caspofungin was significantly more common in patients with S. capitata fungaemia. Thirty‐day mortality was found 40% for patients with candidemia, whereas it was 39% for patients with S. capitata. In conclusion, despite its limitations this study showed that a novel and more resistant yeast‐like pathogen become prevalent due to use of caspofungin in patients with long‐lasting neutropenia which was the most noteworthy finding of this 6‐year surveillance study.

Comparative study ofin vitro methods used to analyse the antifungal activity of propolis againstTrichophyton rubrum andTrichophyton mentagrophytes

The aim of this study was to evaluate thein vitro activity of propolis against clinical isolates ofTrichophyton rubrum andTrichophyton mentagrophytes by following the NCCLS guidelines for testing filamentous fungi, and compare the two methods of evaluating the efficacy of propolis: NCCLS microdilution and agar dilution methods. A broth microdilution method following the recommendations established by the National Committee for Clinical Laboratory Standards (NCCLS) and agar dilution method were used to compare the in vitro activity of propolis with that of itraconazole (ITC) against 29 clinical isolates the dermatophytes belonging to two different species ofTrichophyton. In terms of MICs (minimal inhibitory concentrations), ITC showed greater activity than propolis. MICs of propolis at which 50% (MIC50) and 90% (MIC90) of the isolates were 0.1 and 0.2 μg ml−1, respectively. Propolis merits further investigations as a potentially useful agent for treatment of dermatophytosis and the broth microdilution and the agar dilution methods were good agreement for propolis against dermatophytes. Moreover, the study suggests the potential value of the broth microdilution as a convenient alternative method for testing the susceptibilities of dermatophytes to propolis.