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Biomedical subjects

A Yilmaz

Publications and source records attributed to A Yilmaz.

At least 37 records · Page 2Linked to original sources

Proton T1 and T2 relaxivities of serum proteins.

In the present study, T(1) and T(2) of phantoms containing serum sets with varying amounts of proteins, serum samples with certain amounts of proteins, serum diluted by distilled water, and serum treated with iron were measured. In addition, T(1) and T(2) of phantoms containing normal serum, diluted serum, and albumin-doped serum were also measured. Relaxation rates were plotted versus protein concentrations. The slope of relation was taken as relaxivity. The T(1) relaxivities of proteins were ranged from 0.035 to 0.080 s(-1)(g/dl)(-1), whereas T(2) relaxivities were ranged from 0.24 to 0.68 s(-1)(g/dl)(-1). The T(1) and T(2) relaxivities of transferrin iron were 2.40 and 2.60 mM(-1)s(-1), respectively. The contributions of diamagnetic proteins and transferrin iron to the relaxation rate of serum were also calculated for each of diluted serum, normal and albumin-doped serum. The contributions and the average TP relaxivities(calculated by using individual relaxivities and the ratios of protein fractions in TP) were used for TP calculations. The agreement between the calculated TP and TP by autoanalyzer and also the agreement between average TP relaxivities and the TP relaxivities determined from dilution experiments show that the data of relaxivities are reliable. The results suggest that individual protein relaxivities explain the influence of serum TP composition on T(1) and T(2) relaxation times.

Blood Proteins↗

Seasonal variability in behavioral despair in female rats.

Separate groups of female Wistar rats were tested every three months over a year to assess the extent of seasonal variability in the behavioral despair model of depression consisting of 2 swim tests separated by 24 h. There was a significant seasonal variability in the duration of immobility in the swim tests; duration of immobility was shorter in August and November than in February and May. These findings suggest reduced immobility and susceptibility to behavioral despair in summer and fall compared to winter and spring.

Analysis of Variance↗

Determinants of MR relaxation rates in jaw cysts: implications for diagnostic values of the relaxation times.

OBJECTIVES: The MRI signal intensities and the relaxation times (T1 and T2) have already been used for comparisons among various types of cysts. The signal intensities (or T1 and T2) were suggested to be related to cyst content. However, such a relationship between the relaxation rates (1/T1 and 1/T2) and the aspirated content of jaw cysts was not given. Therefore, an investigation on the determinants of the relaxation rates in the jaw cysts may be helpful in elucidating the biological basis for the differences in relaxation rates among the categories of jaw cysts. METHODS: The aspirated contents of 23 cysts (16 radicular and 7 haemorrhagic) were scanned using an MR imager operating at 1 T magnetic field strength. The viscosities and the dry-weight-to-water-weight ratios (Ms/Mw) were determined. Also, the mean values of cyst categories were compared using statistical analysis. RESULTS: The 1/T1 had a moderate correlation with viscosity (0.66) and Ms/Mw (0.56), while the 1/T2 had a good correlation with viscosity (0.87) and Ms/Mw (0.82). The mean values of viscosity, Ms/Mw and relaxation rates in radicular cysts were significantly lower (P < 0.05) than those of haemorrhagic cysts. CONCLUSIONS: The present data suggest that similarities and differences between relaxation rates of radicular and haemorrhagic cysts can be explained by the solid content and viscosity of cysts.

Body Water↗

Estimation of (co)variance components for reproductive traits in Angus beef cattle divergently selected for blood serum IGF-I concentration.

The objective of this study was to obtain estimates of (co)variance components for reproductive traits and insulin-like growth factor-I (IGF-I) concentration. Data were from a divergent selection experiment for blood serum IGF-I concentration in Angus beef cattle. Numbers of observations for mean IGF-I concentration of three blood samples taken at d 28, 42, and 56 of the 140-d postweaning test, scrotal circumference (SC), percentage of motile sperm cells (PMSC), percentage of morphologically normal sperm cells (PNSC), age of heifers at first calving (AFC), and calving rate (CR) were 1,848, 825, 596, 765, 294, and 2,092, respectively. Total number of animals in the numerator relationship matrix, including base animals, was 2,864, of which 1,861 were inbred. Estimates of direct heritability for IGF-I concentration of three blood samples collected at d 28, 42, and 56 of the postweaning test and for mean IGF-I concentration were 0.43+/-0.08, 0.51+/-0.09, 0.41+/-0.08, and 0.50+/-0.08, respectively. Estimates of direct heritability for SC, PMSC, PNSC, AFC, and CR were 0.51+/-0.13, 0.08+/-0.12, 0.47+/-0.07, 0.26+/-0.28, and 0.11+/-0.05, respectively. With the exception of age at first calving, estimates of maternal heritability and proportion of phenotypic variance that were due to permanent environmental effects of the dams were smaller than 0.21. Observations for calving rate were entered as either 1 (if calved) or 100 (if not calved). Estimates of additive genetic correlations of mean IGF-I concentration with SC, PMSC, PNSC, AFC, and CR were 0.35+/-0.11, 0.43+/-0.32, 0.00+/-0.03, -0.14+/-0.33, and -0.41+/-0.16, respectively. Environmental and phenotypic correlations for all of the traits with IGF-I measurements were smaller than 0.23. These results suggest that selection for increased serum IGF-I concentration should result in increased scrotal circumference, percent motile sperm cells, and calving rate.

Animals↗

[Disinfectant tests at 20 and 10 degrees C to determine the virucidal activity against circoviruses].

To evaluate virucidal activity against porcine circovirus type 2 (PCV2), four disinfectants were tested under laboratory conditions. As basis to perform the testing the "Guidelines for testing chemical disinfectants" of the German Veterinary Association (DVG-guidelines) were applied. For simulation of field conditions, the tests were carried out in virus carrier tests, at 20 and 10 degrees C, and under protein load (40% foetal calf serum (FCS) in virus suspension). For disinfection of PCV2 at 20 degrees C an exposure time of 120 min in 2% Disinfectant 1 (20% glutaraldehyde, 12% 2-propenal, polymer with formaldehyde) or Disinfectant 2 (55% formic acid, 7% glyoxylic acid) was necessary. 1% of Disinfectant 3 (Component 1: Potassium peroxomonosulphate. Component 2: Active detergents) disinfected PCV2 on carriers within 180 min. After a reaction time of 120 min with 1% and 60 min with 2% Disinfectant 4 (21% glutaraldehyde, 17% formaldehyde) there could not be detected any virus. Reduction on effectivity through temperature reduction to 10 degrees C were more significant for aldehyde containing preparations Disinfectant 1 and Disinfectant 4 than for Disinfectant 2 and Disinfectant 3. These losses on effectivity could be corrected through extension of exposure time or increase of concentration.

Animals↗

Contamination of bovine carcasses and abattoir environment by Escherichia coli O157:H7 in Istanbul.

The aim of this study was to investigate contamination of carcasses and abattoir environment with Escherichia coli O157:H7. Five abattoirs in Istanbul were visited between January 2000 and April 2001. During visits, sampling was performed and a total of 330 cattle were selected. Cattle were examined for the presence of faeces on the hide (abdomen and legs) before slaughter. The swabs from the carcasses and environmental samples (abattoir floor, benches including conveyors, knives, aprons, saws, hooks, hands) were taken at the abattoir immediately after slaughter using sterile cotton swabs. A sample from the wash water of the abattoir was also taken. Preenrichment, immunomagnetic separation and CT-SMAC agar were used for the isolation. The reaction of the isolates with anti-O157 and H7 antisera were also analysed. Twelve strains (3.6%) of E. coli O157 were isolated from the cattle carcasses and eight (2.4%) of them gave positive reaction with anti-H:7. Six strains of E. coli O157 were isolated from the environmental samples and all strains were positive for H7. The number of E. coli O157H:7 strains isolated from the environmental samples was two from the knife, two from the hands, one from the apron and one from the floor. No E. coli O157 was isolated from the abattoir water.

Abattoirs↗

Upregulation of CD40-CD40 ligand (CD154) in patients with acute cerebral ischemia.

BACKGROUND AND PURPOSE: Inflammation and hypercoagulability contribute to the development of acute cerebral ischemia. Both can be mediated by the CD40 system. This study investigated whether the CD40 system and related mediators are upregulated in patients with transient ischemic attack (TIA) or stroke. METHODS: Seventeen patients with TIA, 60 patients with complete stroke, and 15 control subjects were investigated. CD154 and P-selectin were analyzed on platelets and CD40 on monocytes during and 3 months after acute cerebral ischemia by double-label flow cytometry. Blood concentrations of soluble CD154 and monocyte chemoattractant protein-1 (MCP-1) were evaluated. RESULTS: Our main findings are as follows: (1) patients with acute cerebral ischemia showed a significant increase of CD154 on platelets and CD40 on monocytes compared with controls; (2) plasma levels of soluble CD154 were significantly higher in these patients; (3) these patients had significantly higher numbers of prothrombotic platelet-monocyte aggregates; (4) the chemoattractant MCP-1 was significantly elevated in cerebral ischemia; and (5) at 3 months' follow-up, upregulation of CD154 still persisted in patients with previous acute cerebral ischemia. CONCLUSIONS: Patients with acute cerebral ischemia show upregulation of the CD40 system, which might contribute to the known proinflammatory, proatherogenic, and prothrombotic milieu found in these patients.

Acute Disease↗

Evaluation of virucidal activity of three commercial disinfectants and formic acid using bovine enterovirus type 1 (ECBO virus), mammalian orthoreovirus type 1 and bovine adenovirus type 1.

A modified version of the test method of the Comité Européen de Normalisation (CEN) was developed using formic acid and three commercial disinfectants to evaluate virucidal activity against three non-enveloped viruses, bovine enterovirus type 1 (ECBO virus), mammalian orthoreovirus type 1 and bovine adenovirus type 1 (BAV 1). Determination of the effects of temperature was carried out at 20 and 10 degrees C. All tests with protein load used bovine serum albumin (BSA) and yeast extract. The investigations were performed in suspension tests and in carrier tests using poplar wood virus carriers. The carrier tests showed that ECBO virus could be inactivated at 20 degrees C with 1% formic acid within a 60 min reaction time. For disinfection of ECBO virus at 10 degrees C within 60 min, a 2% concentration of formic acid was necessary. Formic acid was ineffective against reovirus and bovine adenovirus and cannot be recommended as a reference disinfectant. Inactivation of ECBO virus and adenovirus type 1 using a disinfectant containing aldehydes and alcohols could be achieved, but only at room temperature. The disinfection of reovirus type 1 at room temperature with this product was possible without a protein load. This disinfectant exhibited disinfection ability at 10 degrees C at a concentration of more than 2% or with a longer exposure time. A disinfectant containing aldehydes was effective at room temperature but its effect was reduced in the presence of organic matter. Inactivation at 10 degrees C was found only against adenovirus. The fourth disinfectant, which contained peroxiacetic acid, inactivated all test viruses at a concentration of 0.5% within 15 min independent of temperature and protein load.

Animals↗

Investigations on suitability of different materials for carriers to be used for virucidal testing of chemical disinfectants in the veterinary field.

Various materials with rough surfaces were tested to determine their suitability for virus carrier tests designed to evaluate virucidal activity of chemical disinfectants. A non-enveloped RNA virus, bovine enterovirus type 1, strain LCR 4 [entero cytopathogenic bovine orphan virus (ECBO)] and an enveloped RNA virus, paramyxovirus type 1 [Newcastle disease virus (NDV), strain Montana] served as test viruses. Experiments with ECBO virus were carried out in four sets, and those with NDV in three sets. In the first set we used poplar wood, frosted glass slides and Sartorius membrane filters. The second set comprised of poplar wood, frosted glass slides, polyamide filters, and cellulose nitrate filters and, in the third set, glass fibre filters and glass fibre pre-filters were added. The fourth test included poplar wood, frosted glass slides, and polyethersulphone ultra filters. Because of their extremely low levels of virus recovery, glass, polyamide, cellulose nitrate and glass fibre filter, glass fibre pre-filter, and polyethersulphone ultra filters are not suitable for sufficient recovery of ECBO virus. Only poplar wood carriers allowed sufficient recovery rates of ECBO virus. In the first and second set of tests, NDV could be sufficiently recovered from poplar wood, glass slides, and polyamide filter. In the third set, the virus recovery from polyamide filter was very low. Poplar wood carrier is recommended as a reliable carrier for the tests with both viruses, but methods for virus recovery must be improved, e.g. by more vigorous and longer shaking or optimizing the ultrasonic treatment.

Animals↗

Anetoderma associated with antiphospholipid syndrome and systemic lupus erythematosus.

Anetoderma is an uncommon disorder characterized by the loss of elastic fibres in the dermis histologically and herniation of subcutaneous tissue clinically. Recent studies indicate that immunologic mechanisms may play a role in this process. Here we report a 33-year-old woman with numerous well-circumscribed, asymptomatic skin lesions in whom clinical and histopathologic features were consistent with anetoderma. Additionally, history and investigations revealed antiphospholipid syndrome and systemic lupus erythematosus. It has been speculated that immune deposits in the dermis or within the capillary walls may lead to ischaemia and subsequent degeneration of the elastic fibres.

Adult↗

[Disinfection of caliciviruses at 20 and 10 degrees C].

Five disinfectants, Venno FF super, Venno Vet 1 super, Venno Oxygen, M&Enno-Veterinär B neu und Neopredisan 135-1, were tested to evaluate their efficacy against caliciviruses at 20 and 10 degrees C. As model test virus served feline calicivirus type F9 (FCV F9). All disinfectants were tested according to Guidelines of the German Veterinary Association (DVG). The investigations were performed in suspension tests and germ carrier tests. The suspension tests were carried out without and with protein load. As protein was used foetal calf serum at the concentration of 40%. Venno FF super showed less protein dependence, however a considerable temperature dependence. This matter can be corrected by increase of concentration on 2%. Venno Vet 1 super was without protein especially effective. The losses on the effectiveness through low temperature and protein load can be annulled also here by increase of concentration. Venno Oxygen was more effective in the comparison to that here named both preparations. The effects of temperature can be corrected by extension of reaction time. The most effective preparation was M&Enno Veterinär B neu. The disinfection occurred at 20 degrees C with 0.5% solution within 120 min and at 10 degrees C with 1.0% solution within 60 min. The fifth disinfectant Neopredisan was in suspension tests without protein load and carrier tests with gauze at 20 and 10 degrees C relative convincing but in germ carrier tests with poplar wood, no complete disinfection could be achieved within tested concentrations and reaction times.

Animals↗

Successful treatment of intrathecal morphine overdose.

A 47-year-old woman was diagnosed with secondary progressive multiple sclerosis, and was treated with intrathecal morphine for chronic pain via a slow-release subcutaneous pump. She accidentally received a 35-ml (510 mg) bolus injection of morphine by this route, which led to status epilepticus. She was treated with continuous intravenous naloxone infusion, and with medication to control hypertension and stop the seizure activity. The outcome was excellent, and the patient returned to her neurological baseline. This report describes the complications and the successful treatment of intrathecal morphine overdose. In order to prevent these serious errors, it is vital that only care providers who are proficient with these devices perform the refilling procedure.

Analgesics, Opioid↗

Evaluation of long-term efficacy of an asthma education programme in an out-patient clinic.

The aim of the present study was to evaluate long-term efficacy of a patient education programme in an asthma out-patient clinic. The study included two groups. Educational group consisted of 25 patients who were given special education for one year. Usual care group included 27 patients who were not given special education. All patients were evaluated after 3 years follow-up period. Mean per cent asthma knowledge score (KS%), mean per cent demonstration score (DS%), daytime and nighttime symptom scores, Aas score, and pulmonary function tests were measured. The asthma-quality-of-life assessment was performed. The rate of application to emergency room and admission to hospital for last 1 year had been calculated. KS% was higher in educational group than in usual care group (P < 0.001). Daytime score was 0.3 +/- 0.6 in educational group and was 0.8 +/- 1.2 in usual care group (P = 0.08). Nighttime symptom score was found to be 0.5 +/- 0.9 and 0.9 +/- 1.3, respectively (P = 0.07). Usual care group had higher Aas score compared to educational group (P = 0.048). The total score of quality of life was 197.1 +/- 17.8 in educational group and was 176.7 +/- 33.7 in usual care group (P = 0.009). While none of the patients had emergency room application and hospital admission in educational group, seven patients had 21 emergency room application (P = 0.01) and four patients had four hospital admissions in usual care group. Additional short-acting inhaled beta-2 agonist usage was found lower in the educational group (P = 0.068). In conclusion, proper drug use and usual care of patients are not sufficient for asthma treatment. Patient education is an important component of therapy in asthma patients. For a life with optimum standards, in addition to these factors, patient education must be accepted first by doctors and then by patients.

Adolescent↗

The effects of acute phase proteins on serum albumin, transferrin and haemoglobin in haemodialysis patients.

In the present study, the effects of C-reactive protein (CRP) and ferritin on serum albumin, transferrin and haemoglobin (Hb) were assessed to investigate the relationship between inflammation, hypoalbuminaemia and anaemia in haemodialysis patients. A total of 117 patients who were followed at three haemodialysis units in Kocaeli were enrolled. The mean age was 47.83 +/- 16.85 years. The median time on dialysis was 26 (minimum 1, maximum 209) months. Serum CRP albumin and ferritin concentrations were measured in our laboratory and transferrin, urea reduction ratio (URR) and Kt/V were calculated. There was significant inverse correlation between serum CRP level and albumin (p<0.001), serum CRP and Hb (p<0.001), and serum transferrin and ferritin (p<0.05). There was significant positive correlation between serum albumin and Hb (p<0.001), serum CRP and ferritin (p<0.05), and transferrin and URR (p<0.05). Our findings suggest that inflammation is a contributor in the development of hypoalbuminaemia and anaemia in haemodialysis patients as well as malnutrition and inadequate dialysis.

Adolescent↗

Peritubular capillary basement membrane reduplication in allografts and native kidney disease: a clinicopathologic study of 278 consecutive renal specimens.

BACKGROUND: An association has been found between transplant glomerulopathy (TG) and reduplication of peritubular capillary basement membranes (PTCR). Although such an association is of practical and theoretical importance, only one prospective study has tried to confirm it. METHODS: We examined 278 consecutive renal specimens (from 135 transplants and 143 native kidneys) for ultrastructural evidence of PTCR. In addition to renal allografts with TG, we also examined grafts with acute rejection, recurrent glomerulonephritis, chronic allograft nephropathy and stable grafts ("protocol biopsies"). Native kidney specimens included a wide range of glomerulopathies as well as cases of thrombotic microangiopathy, malignant hypertension, acute interstitial nephritis, and acute tubular necrosis. RESULTS: We found PTCR in 14 of 15 cases of TG, in 7 transplant biopsy specimens without TG, and in 13 of 143 native kidney biopsy specimens. These 13 included cases of malignant hypertension, thrombotic microangiopathy, lupus nephritis, Henoch-Schonlein nephritis, crescentic glomerulonephritis, and cocaine-related acute renal failure. Mild PTCR in allografts without TG did not predict renal failure or significant proteinuria after follow-up periods of between 3 months and 1 year. CONCLUSIONS: We conclude that in transplants, there is a strong association between well-developed PTCR and TG, while the significance of mild PTCR and its predictive value in the absence of TG is unclear. PTCR also occurs in certain native kidney diseases, though the association is not as strong as that for TG. We suggest that repeated endothelial injury, including immunologic injury, may be the cause of this lesion both in allografts and native kidneys.

Basement Membrane↗

Effects of amifostine in a patient with an advanced-stage myelodysplastic syndrome.

We report on a 63-year-old man with myelodysplastic syndrome at the stage of a refractory anemia with an excess of blasts in transformation (MDS-RAEB-T), first diagnosed in December 1996. After a period of stability, with no need for transfusions, the MDS progressed into acute myeloid leukemia (AML) in August 1998 with the emergence of a cytogenetic abnormality (11q-). Two courses of chemotherapy were given, resulting in prolonged pancytopenia; however, no clearance of bone marrow (BM) blasts was achieved. At that time, severe infections and daily epistaxis occurred. Frequent transfusions of packed red blood cells (RBC) and platelets (2-3/week) were necessary. After 2 months of persisting severe pancytopenia, we started a therapy with amifostine: 4 x 250 mg intravenously (i.v.) weekly for 1 month, followed by a maintenance therapy with 500 mg once weekly. After 2 weeks of amifostine therapy, hematopoiesis began to improve. In the subsequent 2 months, the patient became completely independent of the platelet transfusions; the transfusion frequency of RBC was permanently reduced (2 RBC transfusions/month) and a significant decrease of BM blasts was achieved. After 30 weeks of amifostine therapy, the morphology of the MDS switched to a chronic myelomonocytic leukemia (CMML)-like appearance, with continuously increasing leukocytes, so that we discontinued amifostine therapy for 1 month to exclude a possible side effect of amifostine. At that time, leukocytes further increased to 74,000/microl; thus, we decided to perform a cytoreductive chemotherapy (hydroxycarbamide) and continued weekly amifostine infusions. During 1 year of amifostine therapy, the patient had a good quality of life, with no need for hospitalization and a complete cytogenetic remission. We conclude that, in this case, amifostine had two effects: a significant improvement of impaired hematopoiesis and a slowing down of disease progression. Thus, amifostine might be a therapeutic option in older patients with advanced MDS.

Amifostine↗