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Biomedical subjects

N Sahin

Publications and source records attributed to N Sahin.

At least 37 records · Page 2Linked to original sources
PubMed2002

Magnesium infusion reduces perioperative pain.

BACKGROUND AND OBJECTIVE: Magnesium has antinociceptive effects in animal and human models of pain. These effects are primarily based on the regulation of calcium influx into the cell. The aim of this study was to determine whether perioperative infusion of magnesium would reduce postoperative pain and anxiety. METHODS: Twenty-four patients, undergoing elective hysterectomy, received a bolus of 30 mg kg(-1) magnesium sulphate or the same volume of isotonic sodium chloride solution intravenously before the start of surgery and 0.5 g h(-1) infusion for the next 20 h. Intraoperative and postoperative analgesia were achieved with fentanyl and morphine respectively. Patients were evaluated pre- and postoperatively for anxiety. RESULTS: Fentanyl consumption and total morphine requirements were significantly decreased in the magnesium group compared to the control group. Postoperative anxiety scores and sedation were similar between groups. CONCLUSIONS: Continuous magnesium infusion, including the pre-, intra-, and postoperative periods reduces analgesic requirements. These results demonstrate that magnesium can be an adjuvant for perioperative analgesic management.

Adult↗
PubMed2002

The effect of toluidine blue on the survival, dormancy and outer membrane porin proteins (OmpC and OmpF) of Salmonella typhimurium LT2 in seawater.

AIMS: To study the relationship between changes in the composition of the outer membrane proteins and the survival of Salmonella typhimurium LT2 in filtered autoclaved seawater containing Toluidine Blue (TB) dye as a photosensitizer. METHODS AND RESULTS: In samples exposed to TB and excited by artificial visible light, the total viable (TVC) and respiring cell counts (RCC) showed that, although the TVC declined to an undetectable level in 6.5 h, the RCC showed that some cells were still capable of respiration. The porin protein composition changed gradually with OmpC and OmpF becoming undetectable by sodium dodecyl sulphate-polyacrylamide gel electrophoresis after 8 h of incubation. Hydrogen peroxide-pretreated cells survived longer compared with the control. CONCLUSIONS: Oxidative pretreatment of Salm. typhimurium protects cells from some of the effects of sunlight in the presence of photosensitizers. The changes in porin proteins may play a role in this protection. SIGNIFICANCE AND IMPACT OF THE STUDY: The study shows that the survival of bacteria under conditions of stress is the result of a linked series of reactions.

Bacterial Outer Membrane Proteins↗
PubMed2002

The effect of nitric oxide synthase blockade on responses to morphine in rat aortic rings.

1 It has been suggested that opioids may play an indirect role in the regulation of the peripheral circulation through the control of nitric oxide (NO) release in vascular tissue. The current study was undertaken to investigate the effect of nitric oxide synthase (NOS) blockade on responses to morphine in phenylephrine (PE)- or KCl-precontracted rat aortic rings. 2 Morphine (3 x 10(-8) - 3 x 10(-5) M) administration did not cause any significant effect on basal tonus of endothelium-intact or endothelium-denuded preparations. Morphine produced concentration-dependent relaxation responses in endothelium-intact as well as in endothelium-denuded rat aortic rings precontracted by PE or KCl. Removal of endothelium did not significantly alter the relaxation responses to morphine. 3 The relaxant responses to morphine were significantly and partially inhibited by pretreatment of tissues with naloxone (NAL, 3 x 10(-5) M) for 5 min. The inhibitory effect of NAL on relaxant responses to morphine in PE- or KCl-precontracted rings did not differ significantly between endothelium-intact and endothelium-denuded preparations. 4 Incubation of endothelium-intact or endothelium-denuded rat aortic rings with NOS inhibitor, Nomega-nitro-L-arginine methyl ester (L-NAME, 10(-4) M) for 20 min did not cause a significant inhibition on relaxation responses to morphine. 5 These findings confirmed the presence of opiate receptors in rat thoracic aorta, but suggested that mechanisms other than NO release play a role in the relaxant effect of morphine on rat aortic rings.

Animals↗
PubMed2002

Effects of dietary chromium picolinate and ascorbic acid supplementation on egg production, egg quality and some serum metabolites of laying hens reared under a low ambient temperature (6 degrees C).

This experiment was conducted to evaluate the effects of chromium (chromium picolinate, Cr Pic) and vitamin C (L-ascorbic acid) supplementation on egg production and egg quality in laying hens (Hy-Line) kept at 18 degrees C (at thermo-neutral zone) or 6 degrees C (cold stress) in temperature-controlled rooms. One hundred and fifty laying hens (32 week-old) were divided into 5 groups, 30 hens per group. The laying hens kept at 6 degrees C temperature were fed either a basal diet (low temperature-basal diet, LTB group) or the basal diet supplemented with either 400 micrograms of Cr per kg diet (Cr group), 250 mg of L-ascorbic acid per kg diet (Vit C group) or 400 micrograms of Cr plus 250 mg of L-ascorbic acid per kg diet (Vit C + Cr group) while hens kept at 18 degrees C fed a basal diet (thermo-neutral-basal diet, TNB group). Performance and egg quality were significantly reduced in LTB group compared with TNB group. Supplemental chromium and vitamin C significantly increased live weight change, egg production, and improved feed efficiency in cold-stressed hens compared with group fed the basal diet at 6 degrees C brought up to the values of the group reared under thermoneutral conditions (18 degrees C). Egg production and egg weight were also greater in each supplemental group compared with the LTB group. Separately or as a combination, supplemental chromium and vitamin C increased serum insulin but decreased corticosterone, glucose and cholesterol concentrations. Results of the present study show that supplementing vitamin C and chromium, particularly as a combination, improved the performance of cold-stressed hens. Such a combination of supplement can offer a potential protective management practice in preventing cold stress-related losses in performance of laying hens.

Animals↗
PubMed2001

Effects of dietary chromium picolinate supplementation on performance and plasma concentrations of insulin and corticosterone in laying hens under low ambient temperature.

This experiment was conducted to evaluate the effects of chromium (chromium picolinate) on performance and plasma concentrations of insulin and corticosterone of laying hens (Ross Brown) under a low ambient temperature (6.9 degrees C). One hundred and twenty laying hens (46 weeks old) were divided into four groups, 30 hens per group. The laying hens were fed either a control diet containing 710.3 p.p.b. chromium or the control diet supplemented with 100, 200 or 400 microg chromium/kg diet. Increasing supplemental chromium increased live weight change (p < or = 0.001, linear) and egg production (p < or = 0.001, linear) and also improved feed efficiency linearly (p < or = 0.001). Live weight change and egg production also had quadratic responses (p < or = 0.001) to increasing chromium supplementation. Plasma insulin concentration increased linearly (p < or = 0.001), whereas corticosterone concentration decreased linearly (p < or = 0.001) as dietary chromium supplementation increased. The results of this study indicate that supplemental dietary chromium, 200 p.p.b. in particular, had a positive effect on performance and increased the plasma insulin concentration of laying hens under cold stress.

Animals↗
PubMed2001

Coronary artery bypass grafting nine months after pneumonectomy.

We performed coronary artery bypass grafting on a 58-year-old man who only 9 months earlier had undergone right pneumonectomy for bronchial carcinoma. Although his preoperative pulmonary function had been poor, coronary artery bypass surgery was successful, and the patient was discharged on the 9th postoperative day Two years after surgery, he remained in New York Heart Association functional class I. We attribute this success to special management before, during, and after the operation. On the 32nd postoperative month, this patient died of multiple tumor metastases.

Angina, Unstable↗
PubMed2001

[Heart wounds].

In our study, we aimed to present our cases with heart wounds and to determine the factors influencing mortality. We retrospectively evaluated 23 cases with cardiac injuries who were treated among years 1986-99 in our clinic. There were 4 female and 19 male cases, and the average age was 32 years (range 12-52). Heart wounds were caused by blunt trauma in 6 cases, and penetrating trauma in 17 cases. Penetrating heart wounds was caused by gunshot wounds in four patients and stab wounds in 13 patients. Our cases were underwent to rapid resuscitation and emergency surgery. Mortality rate was 17% with 3 cases. Blunt cardiac wounds was caused by motor vehicle accidents in all cases. Diagnosis with immediate echocardiography and efficient treatment was performed. Mortality rate was 33% with 2 cases. We think that emergent resuscitation and immediately surgical exploration in patients with penetrating heart wounds and immediate diagnosis by echocardiography and prompt treatment in patients with blunt heart injuries may improve overall survival.

Adolescent↗
PubMed2000

Taxonomic position of "Pseudomonas oxalaticus" strain ox14T (DSM 1105T) (Khambata and Bhat, 1953) and its description in the genus Ralstonia as Ralstonia oxalatica comb. nov.

"Pseudomonas oxalaticus" strain Ox1T (= DSM 1105T), which was described as an oxalate-decomposing bacterium, was reinvestigated to clarify its taxonomic position. 16S ribosomal DNA sequence comparisons demonstrated that this species is phylogenetically related to the species of the genus Ralstonia. and represents a new species. The result of the DNA-DNA hybridization value was supported in this placement. Strain Ox1T is closely related to Ralstonia eutropha with a less than 60% DNA-DNA hybridization value. The new name Ralstonia oxalatica comb. nov. is proposed to strain Ox1T, on the basis of these results and previously published data for the G+C content of the genomic DNA and the phenotypic characters.

Bacterial Typing Techniques↗
PubMed1999

Classification of thermophilic streptomycetes, including the description of Streptomyces thermoalcalitolerans sp. nov.

A polyphasic taxonomic study was undertaken to clarify relationships within and between representative thermophilic alkalitolerant streptomycetes isolated from soil and appropriate marker strains. The resultant data, notably those from DNA-DNA relatedness studies, support the taxonomic integrity of the validly described species Streptomyces thermodiastaticus, Streptomyces thermoviolaceus and Streptomyces thermovulgaris. However, the genotypic and phenotypic data clearly show that Streptomyces thermonitrificans Desai and Dhala 1967 and S. thermovulgaris (Henssen 1957) Goodfellow et al. 1987 represent a single species. On the basis of priority, S. thermonitrificans is a later subjective synonym of S. thermovulgaris. Similarly, 10 out of the 11 representative thermophilic alkalitolerant isolates had a combination of properties consistent with their classification as S. thermovulgaris. The remaining thermophilic alkalitolerant isolate, Streptomyces strain TA56, merited species status. The name Streptomyces thermoalcalitolerans sp. nov. is proposed for this strain. A neutrophilic thermophilic isolate, Streptomyces strain NAR85, was identified as S. thermodiastaticus.

DNA, Bacterial↗
PubMed1999

The comparison of intraocular pressure reductions after isometric and isokinetic exercises in normal individuals.

The lowering effect of physical exercise on intraocular pressure (IOP) has been reported both in healthy people and those with glaucoma, but a comparison of the lowering effect of isometric and isokinetic exercises on IOP has not been conducted in any study. Our aims were to investigate the relationship between intensity of exercise and IOP, and whether a significant difference in IOP lowering effect existed between isometric and isokinetic exercises. Sixty-seven patients with an age range of 23-40 who had no ocular disease were randomly divided into two groups. While 31 patients in the first group, group A, performed isokinetic exercise with the Cybex 6000 dynamometer, 32 patients in the second group, group B, had isometric exercises with the same machine. IOP was measured in the right eye of patients with Shiotz tonometer just before and 10 min following exercise. Exercise intensity and total energy consumption were determined by the machine for each patient. While IOP values measured before exercise, the degree of exercise applied, and total energy consumption did not differ significantly between groups, both isometric and isotonic exercises lowered IOP significantly. As a result, isometric and isokinetic exercises lowered IOP in ophthalmologically normal subjects with direct relationship to exercise intensity and total energy consumption. Since the pressure lowering effect of isokinetic exercise was more significant, it might prove useful to glaucomatous patients.

Adult↗
PubMed1999

Replacement of an immobile prosthetic mitral valve: a case report.

A mechanical prosthetic heart valve can become acutely obstructed despite anticoagulation therapy. This can be a life-threatening complication. We report the case of a 38-year-old woman who survived obstruction of her Sorin prosthetic mitral valve. She was admitted to the hospital because of severe pulmonary edema. On auscultation, mechanical valve sounds were absent. Transthoracic echocardiography showed an immobile mechanical valve. The patient suffered a cardiac arrest while being prepared for surgery, but she underwent successful mitral valve replacement after cardiopulmonary resuscitation. When patients with prosthetic mitral valves present with acute dyspnea, the possibility of an obstructed prosthetic valve must be considered in the differential diagnosis.

Adult↗
PubMed1997

Shigella gastroenteritis: clinical and epidemiological aspects, and antibiotic susceptibility.

The epidemiology and antibiotic sensitivity of Shigella species is changing worldwide. The present study surveyed the changing clinical and epidemiological characteristics and antibiotic susceptibility of Shigella gastroenteritis in Hacettepe University Ihsan Dogramaci Children's Hospital Diarrhoea Training and Treatment Unit between 1987 and 1994. Among 19,812 diarrheal admissions, 618 (3.2%) patient files with Shigella gastroenteritis were reviewed retrospectively. Shigella soneii has been the commonest isolate (64%) since 1987 followed by S. flexineri (30%), S. boydii (5%) and S. dysenteriae (1%), the latter having not been isolated since 1990. The isolate rate of S. sonnei has increased whereas the isolation rate of S. flexineri has decreased concomitantly since 1987 (r = -0.94; P < 0.001). The majority of cases (365/618, 59%) were between 1 and 5 years of age. On admission bloody diarrhea was present in 36%, seizures in 3% and mild-moderate dehydration in 11% of cases. No case had severe dehydration. Only six patients (1%) were hospitalized. No deaths were recorded. The resistance rate for trimethoprim-sulfamethoxazole has increased from 27% in 1990 to 66% in 1994 (P < 0.05) while the resistance rate for ampicillin has decreased from 81% in 1987 to 32% in 1993 (P < 0.001). Shigella flexineri was found to have higher resistance rates to ampicillin, sulbactam-ampicillin, chloramphenicol and gentamicin than S. sonnei. Changing Shigella sp. over the years may be the reason for the mild course of Shigella gastroenteritis. Further regional epidemiological studies are necessary to develop more appropriate management guidelines, especially in developing countries.

Adolescent↗
PubMed1995

Fears of children and the cultural context: the Turkish norms.

The present study was undertaken to identify children's fears in terms of their age, gender and Socio Economic Status (SES) characteristics. Another aim of the study was the adaptation and the standardization of the "Fear Survey Schedule for Children" (FSSC) to Turkish population and to determine its psychometric properties. FSSC was given to 1237 Lower SES children aged 9-13 years. To understand the effects of social and environmental factors the results were compared with 644 children from high socio-economic level and 118 children of Turkish immigrant labourer families residing in Holland. The most prevalent 10 fear items in all three groups were also determined. Results indicated that girls had more intense and frequent fears at all age levels than boys. Low SES children reveal more fears compared to their high SES pears of their self reported fears. Fears related to death and separation occupy the top positions and religious fears that are mentioned very often by children especially by those in the lower SES group. Test-retest reliability, internal consistency and the factorial structure of the scale have proved it to be a valuable and reliable tool for research and clinical purposes in Turkey.

Adolescent↗
PubMed1995

The concentration of plasma atrial natriuretic peptide in normotensive and preeclamptic pregnancies.

UNLABELLED: Atrial natriuretic peptide (ANP) is a family of peptides secreted by the heart, affecting the cardiovascular, renal and endocrine systems. This study questions previous research findings regarding elevated ANP levels, despite vasoconstriction and hypovolemia, in preeclamptic patients. MATERIALS AND METHODS: Seventeen patients with preeclampsia, 5 with superimposed preeclampsia with chronic hypertension and 17 normotensive pregnant women were compared with respect to plasma ANP levels. Seventeen non-pregnant women were taken as the control group. All the women, except the ones with superimposed preeclampsia, were age matched and in their third trimester. RESULTS: ANP levels in the non-pregnant women (6.9 +/- 0.7 pg/ml) were not different from those in the normotensive pregnant women (6.4 +/- 0.7 pg/ml). ANP levels were significantly higher in women with preeclampsia (10.8 +/- 1.8 pg/ml) or superimposed preeclampsia (9.7 +/- 1.4 pg/ml) than in normotensive pregnant women and normal non-pregnant women (P < 0.05). According to the literature, there is a volume depletion in preeclamptic women. However, this wasn't demonstrated in our study group. CONCLUSION: ANP levels in preeclamptic women were found to be higher than those in normotensive pregnant women. The etiology still remains obscure.

Adolescent↗
PubMed1995

Change in atrial natriuretic peptide concentration after acute plasma volume expansion in normal pregnancy and preeclampsia.

Atrial natriuretic peptide (ANP) is found to be elevated in preeclamptic patients despite the presence of hemodynamic characteristics such as vasoconstriction and hypovolemia. In this study, the effect on ANP secretion of plasma volume expansion with crystalloid solutions was investigated. Seven preeclamptic and seven normotensive pregnant women in their last trimester were compared. After basal ANP measurements, 0.9% Ringer's solution, 15 cm3/kg body weight was infused within 30 min to expand the plasma volume. Blood sampling was repeated after the infusion. Maternal blood volume expansion was calculated from the decrease in hematocrit. Plasma ANP levels were corrected according to the degree of volume expansion. Basal mean levels in both groups were not different. Although the postinfusion levels of ANP in normotensive pregnant women were similar to the basal levels (means +/- SE: 20.6 +/- 0.41 and 27.2 +/- 0.52 pg/ml, respectively, p = 0.10), the postinfusion ANP levels in preeclamptic women increased significantly (21.4 +/- 0.31 and 34.1 +/- 0.28 pg/ml, respectively, p = 0.01). Preeclampsia is associated with a greater increase in plasma ANP levels in response to volume expansion compared with normotensive pregnancy. The greater change in the right atrial pressure with volume expansion, due to decreased compliance of the capacitance vessels in preeclamptic subjects might explain the greater change in the plasma level of ANP.

Adolescent↗