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Biomedical subjects

S Tekin

Publications and source records attributed to S Tekin.

At least 19 recordsLinked to original sources
PubMed2006

Neuropsychiatric symptoms in patients with Parkinson's disease and dementia: frequency, profile and associated care giver stress.

OBJECTIVE: To explore the profile of neuropsychiatric symptoms in patients with dementia associated with Parkinson's disease (PDD). METHODS: 537 patients with PDD drawn from an international multicentre clinical trial of rivastigmine were assessed using the 10-item Neuropsychiatric Inventory (NPI). A cluster analysis was used to investigate the inter-relationship of NPI items. Associations between the clusters and demographic and clinical variables were analysed. RESULTS: 89% of the patients presented at least one symptom on the NPI, 77% had two or more symptoms and 64% had at least one symptom with a score > or = 4. The most common symptoms were depression (58%), apathy (54%), anxiety (49%) and hallucinations (44%). Patients with more severe dementia and advanced Parkinson's disease had more neuropsychiatric symptoms. Nearly 60% of the care givers reported at least one NPI symptom to be of at least moderate severe distress. Five NPI clusters were identified: one group with few and mild symptoms (52%); a mood cluster (11%, high scores on depression, anxiety and apathy); apathy (24%; high apathy and low scores on other items); agitation (5%, high score on agitation and high total NPI score); and a psychosis cluster (8%; high scores on delusions and hallucinations). The psychosis and agitation clusters had the lowest Mini-Mental State Examination score and the highest Unified Parkinson's Disease Rating Scale and care giver distress scores. CONCLUSION: Neuropsychiatric symptoms are common in patients with PDD. The profile of these symptoms differs from that in other types of dementia. Subgroups with different neuropsychiatric profiles were identified. These subgroups may be associated with distinct neurobiological changes, which should be explored in future studies.

Aged↗
PubMed2006

Attentional deficits affect activities of daily living in dementia-associated with Parkinson's disease.

OBJECTIVE: To investigate the effects of attentional deficits on activities of daily living (ADL) in patients with dementia associated with Parkinson's disease (PDD). METHOD: 461 patients were assessed neuropsychologically. Factor analyses were used to differentiate attention from other cognitive functions and to differentiate different aspects of ADL functions. The effects of the attentional measure on ADL were examined using sequential multiple regression, controlling for age, sex, education, severity of motor symptoms and other cognitive functions. RESULTS: Three cognitive factors were identified, with one factor emerging as a measure of vigilance and focused attention. This factor predicted different aspects of ADL status even after controlling for motor functions and other cognitive factors. The attention factor was the single strongest cognitive predictor of ADL status, matching the strength of the effects of motor functions on ADL status. CONCLUSION: Impaired attention is an important determinant of ADL functions in patients with PDD.

Activities of Daily Living↗
PubMed2006

Cardiac safety of rivastigmine in Lewy body and Parkinson's disease dementias.

Cholinesterase inhibition in patients with Alzheimer's disease (AD) may affect heart rate, sometimes inducing bradycardia. Additional cardiac safety considerations apply in patients with dementia with Lewy bodies (DLB) and Parkinson's disease (PDD), in whom cardiovascular autonomic nervous system dysfunction is common. We conducted a review of the safety data available for rivastigmine in these two conditions. A modest reduction in the mean heart rate of 1.5-2 bpm was seen. No clinically meaningful treatment differences in bradycardia or ECG abnormalities were apparent. Compared with placebo, rivastigmine appeared to be associated with fewer vascular disorder adverse events (AEs) (p = 0.002) and fewer AEs of syncope (p = 0.018) in PDD patients (n = 541). A smaller randomised, placebo-controlled study of rivastigmine in DLB (n = 120) showed similar findings. Rivastigmine appears to have a favourable cardiac safety profile in PDD and DLB patients.

Aged↗
PubMed2005

[Effectiveness of clonidine and fentanyl addition to bupivacaine in postoperative patient controlled epidural analgesia].

BACKGROUND AND OBJECTIVES: The aim of this prospective randomized double-blinded study was to compare the analgesic and side-effects of bupivacaine in combination with clonidine or fentanyl during patient-controlled-epidural analgesia (PCEA) in the postoperative period after abdominal hysterectomy. METHODS: 75 patients from 18 to 65 years of age with ASA status I - II were investigated. After preoperative epidural catheterization, the patients were operated in general anesthesia. After surgery, the patients were randomly allocated to 3 PCEA-groups: Group B 0.125 % bupivacaine, Group F 0.125 % bupivacaine plus 1 microg x ml (-1) fentanyl, Group C 0.125 % bupivacaine plus 0.75 microg x ml (-1) clonidine (10 ml loading dose, 5 ml repetitive bolus dose, 10 min lockout time, 30 ml limit within 4 h). During the following 24 hours, hemodynamic parameters, pain score using visual analog scale (VAS), total analgesic consumption, additional analgesic requirements, sedation, satisfaction, nausea scores and probable side-effects were evaluated. RESULTS: Total analgesic consumption was not different between Group F and Group C, but lower than in Group B (p < 0.05). Additional analgesic use was not different between the groups. Group F and Group C had lower VAS-scores in 24 hours than Group B (p < 0.05). Hemodynamic and sedation scores of patients were not different. In Group C, incidence of nausea was lower and satisfaction of patients was higher (p < 0.05). CONCLUSIONS: Addition of clonidine or fentanyl to local anesthetics for PCEA can reduce the analgetic demand. Epidural clonidine can reduce postoperative nausea and is connected with higher patients' satisfaction.

Adolescent↗
PubMed2004

Impact of APOE in mild cognitive impairment.

OBJECTIVE: The authors aimed to use baseline data of an ongoing large, prospective study in subjects with mild cognitive impairment (MCI) to investigate the impact of APOE genotype on the symptom profile of the condition. METHODS: Cognitive assessments included the AD Assessment Scale cognitive subscale (ADAS-cog), the Mini-Mental State Examination (MMSE), and a cognitive battery for assessment of memory, attention, and executive function. Behavioral assessments included the Neuropsychiatric Inventory and Beck Depression Inventory. Activities of daily living were assessed by the AD Cooperative Study Activities of Daily Living (ADCS-ADL) scale. Hippocampal volumes were measured with MRI. RESULTS: A total of 494 of 1,018 study subjects provided APOE data. Approximately 40% of the subjects were APOE epsilon4 carriers. APOE epsilon4 carriers had lower MMSE (p = 0.01) and higher ADAS-cog (p < 0.0001) scores than noncarriers, indicating worse cognitive impairment. APOE epsilon4 carriers also had greater deficits on New York University delayed paragraph recall and Buschke free and cued selective reminding tests, and on the ADCS-ADL scale (p < 0.001). They also had smaller hippocampal volumes (p = 0.002). Behavioral scores were similar across the subgroups. CONCLUSION: MCI subjects carrying the APOE epsilon4 allele showed distinct cognitive and imaging profiles, which appeared to resemble those of early Alzheimer patients. APOE epsilon4 genotype was associated with greater impairments in memory and functional activities as well as hippocampal atrophy.

Activities of Daily Living↗
PubMed2004

Behavioral symptoms in mild cognitive impairment.

The authors investigated neuropsychiatric symptoms in mild cognitive impairment (MCI) from baseline data of the Investigation in the Delay to Diagnosis of AD with Exelon (InDDEx) study (n = 1,010). Neuropsychiatric symptoms were reported in 59% of subjects (Neuropsychiatric Inventory [NPI]). NPI+ subjects had significantly greater impairment on global, cognitive, and functional scores than NPI- subjects. The presence of neuropsychiatric symptoms appears to be a marker of MCI severity.

Aged↗
PubMed2003

Pericardial collar modification for Ross procedure.

Although the surgical technique of the Ross operation has been improved over the years, there are still some technical difficulties: (1) The possibility of damage to first septal artery during harvesting and reconstruction of right ventricular outflow tract (RVOT). (2) Weak posterior anastomotic area during RVOT reconstruction. (3) Persistent bleeding from septal dissection site of pulmonary autograft. To deal with these difficulties, we used a 1-cm wide pericardial strip (pericardial collar) which was sutured to epicardium at the posterior and septal edge of the RVOT. The conduit used for the reconstruction of pulmonary outflow was then sutured to this pericardial strip at the posterior part of the anastomosis. We found this technique very useful to create a safe and strong margin for the posterior suture line. Persistent bleeding from septal dissection site can be also avoided using this modification by diverting the bleeding site into the right ventricular cavity.

Cardiopulmonary Bypass↗
PubMed2003

Genetic divergence in cellular resistance to heat shock in cattle: differences between breeds developed in temperate versus hot climates in responses of preimplantation embryos, reproductive tract tissues and lymphocytes to increased culture temperatures.

The detrimental effects of heat stress on fertility in cattle are less pronounced in heat-tolerant breeds. Although these genetic differences reflect differences in thermoregulation, cells from heat-tolerant breeds are less adversely compromised by increased temperature (that is, heat shock) than cells from heat-sensitive breeds. Experiments were performed to test the hypothesis that cells and tissues from two thermotolerant breeds (Brahman and Senepol) are better able to survive and function after exposure to increased temperature than cells and tissues from two thermosensitive breeds (Holstein and Angus). Exposure of embryos at>eight-cell stage at day 5 after insemination to heat shock of 41.0 degrees C for 6 h decreased development to the blastocyst stage and the number of cells per embryo. However, the deleterious effect of heat shock on blastocyst formation and the number of cells per embryo was less pronounced for Brahman than for Holstein and Angus breeds. Embryos from Senepol cows had very low development and it was not possible to determine heat shock effects in this breed. In contrast to the sensitivity of embryos to heat shock, there was no effect of a 41.0 degrees C heat shock on [(3)H]leucine incorporation into proteins secreted by oviductal or endometrial explants. Lymphocytes from Brahman and Senepol cows were more resistant to heat-induced apoptosis than lymphocytes from other breeds. Heat shock reduced lymphocyte glutathione content but the magnitude of the decrease was not affected by breed. In conclusion, embryos from Brahman cows are more resistant to heat shock than embryos from Holstein or Angus cows. Genetic differences are also present in thermotolerance for apoptosis response in lymphocytes, with Brahman and Senepol cattle being more resistant to heat shock than Angus and Holstein breeds. It is likely that the evolutionary forces that led to the Brahman and Senepol breeds being adapted to hot climates resulted in the selection of genes controlling resistance to cellular heat shock.

Analysis of Variance↗
PubMed2001

Local versus systemic control of numbers of endometrial T cells during pregnancy in sheep.

Pregnancy in sheep is associated with changes in numbers of specific T-lymphocyte populations in the uterine endometrium. These changes probably contribute to evasion by the conceptus of maternal immunological rejection and indicate a possible role for T cells in placental growth, parturition and post-parturient uterine defence against infection. The purpose of the present experiment was to evaluate the relative importance of systemic signals (i.e. those present throughout the uterus or from the circulation, including conceptus hormones secreted into the maternal blood) versus locally acting conceptus signals for regulating changes in numbers of endometrial lymphocytes during pregnancy. The approach taken was to surgically confine pregnancy to one uterine horn and compare differences in lymphocyte numbers between the two uterine horns as well as between both horns of pregnant ewes with those of ovariectomized ewes. As compared with ovariectomized ewes, there was a decline in numbers of CD45R+ lymphocytes within glandular epithelium and an increase in gammadelta T-cell number within the luminal epithelium. These changes occurred in both the pregnant and non-pregnant uterine horns of unilaterally pregnant ewes. Moreover, there were no significant differences in lymphocyte numbers between the two uterine horns of unilaterally pregnant ewes. Expression of CD25 was absent in tissues from both uterine horns. In conclusion, changes in numbers of endometrial lymphocytes during pregnancy, rather than due to locally acting signals of conceptus origin, are the result of hormonal signals of maternal or conceptus origin that either act directly on endometrial lymphocytes or stimulate the uterine endometrium to induce synthesis of regulatory molecules that affect lymphocyte dynamics.

Animals↗
PubMed2001

Activities of daily living in Alzheimer's disease: neuropsychiatric, cognitive, and medical illness influences.

Using a retrospective data analysis, the authors investigated the relationships between instrumental activities of daily living (IADLs) and neuropsychiatric symptoms, cognitive impairment, and medical illness burden in patients with Alzheimer's disease (AD). One hundred forty-three patients fulfilling the clinical criteria for probable or possible AD in an outpatient clinic were assessed for IADLs, neuropsychiatric symptoms, cognitive impairment, and medical illness burden with the Functional Activities Questionnaire (FAQ), Neuropsychiatric Inventory (NPI), Mini-Mental State Exam (MMSE), and Cumulative Illness Rating Scale-Geriatric (CIRS-G). Both MMSE and NPI scores related significantly to IADLs as measured by the FAQ. Several psychiatric symptoms were correlated significantly with IADLs. FAQ scores had no correlation with CIRS-G. Neuropsychiatric findings also were associated significantly with MMSE and had a weak correlation with CIRS-G scores. IADLs changed with cognition and neuropsychiatric disturbances in AD. Medical illness burden had little influence on functional status and a limited impact on neuropsychiatric symptoms.

Activities of Daily Living↗
PubMed2001

Orbitofrontal and anterior cingulate cortex neurofibrillary tangle burden is associated with agitation in Alzheimer disease.

Few studies evaluate neuropathological correlates of behavioral changes in Alzheimer disease (AD). We identified 31 autopsy patients with a diagnosis of definite AD. Behavioral changes were assessed with the Neuropsychiatric Inventory. Brain sections were collected from bilateral orbitofrontal and left anterior cingulate, superior temporal, inferior parietal, occipital, and hippocampal cortices for quantification of neurofibrillary tangles (NFTs) and diffuse and neuritic plaques. Sections from frontal, cingulate, and hippocampal cortices were reviewed for the presence of Lewy bodies (LBs). Hypothesis-driven correlational analyses were performed by the bootstrap method. Subgroup analyses contrasted a group with high scores of one specific behavior to a group with low scores after equating groups for other behaviors. NFT burden in the left orbitofrontal cortex across all 31 patients significantly correlated with agitation scores (r = 0.41, p < 0.015) and NFTs correlated significantly (r = 0.66, p = 0.004) with higher agitation scores in the subgroup analysis. Left anterior cingulate NFTs, although not within our hypotheses, also showed a significant relationship to agitation within the subgroups (r = 0.76, p = 0.0003; Bonferroni p = 0.02). Seven patients, including three in the agitation subgroup, had cortical LBs. Aberrant motor behavior and NFT density in the left orbitofrontal cortex showed a significant relationship for the entire group (r = 0.38, p < 0.03) and for subgroups (r = 0.49, p = 0.04), whereas apathy and left anterior cingulate NFTs showed a significant relationship only for the entire group (r = 0.25, p < or = 0.01). These observations suggest that agitation and aberrant motor behavior are correlates of greater NFT pathology in the orbitofrontal cortex in AD, whereas increasing apathy may relate to greater NFT burden in the anterior cingulate.

Aged↗
PubMed2000

Gastric tonometer monitoring in infants undergoing repair of coarctation of the aorta.

OBJECTIVE: To evaluate gastric tonometer monitoring for splanchnic hypoperfusion in infants during surgical intervention for aortic coarctation, especially within aortic cross-clamp periods. DESIGN: A prospective study. SETTING: Cardiovascular intensive care unit in a university hospital. PARTICIPANTS: Fourteen infant patients after elective, uncomplicated repair of coarctation of the aorta. INTERVENTIONS: After the anesthesia induction, a 7F tonometry catheter was inserted into the stomach oropharyngeally. Gastric carbon dioxide, arterial blood gases, blood pressure of upper extremities, and hematocrit values were measured in 5 different time intervals. Time periods were as follows: T1 (after the anesthesia induction), T2 (before aortic cross-clamp), T3 (immediately after aortic cross-clamp removal), T4 (40 minutes after aortic cross-clamp removal), and T5 (as the patient reached the intensive care unit). Intramucosal pH was measured by means of the Henderson-Hasselbach equation. The mean values of all parameters were calculated. According to T1 time, T2, T3, T4, and T5 times were compared with Student's t-test. MEASUREMENTS AND MAIN RESULTS: Mean aortic cross-clamp time was 19.4 +/- 6.6 minutes. Intramucosal pH values of T3 (p < 0.001) and T4 (p < 0.01) were found to be lower than values of T1. The gastric carbon dioxide values of T3 were significantly higher than T1 (p < 0.01), and bicarbonate and arterial pH values of T3 were significantly lower (p < 0.01). There were no significant differences in other parameters over time intervals. CONCLUSION: Splanchnic hypoperfusion exists during aortic cross-clamping in infant aortic coarctation surgery, and the tonometric catheter is considered to be a safe method for monitoring this hypoperfusion.

Aortic Coarctation↗
PubMed2000

Differences in lymphocyte-regulatory activity among variants of ovine IFN-tau.

Interferon-tau (IFN-tau) is secreted from trophectoderm of the ruminant preimplantation conceptus and functions during pregnancy to prevent luteolysis. In addition, IFN-tau can inhibit proliferation of peripheral blood lymphocytes (PBL) and other cells. Several distinct ovine IFN-tau (OvIFN-tau) gene variants exist; three of these (IFN-tau4, IFN-tau6d, IFN-tau11) differ in their ability to prevent luteolysis (IFN-tau4 > IFN-tau6d > IFN-tau11), inhibit growth of Daudi cells (IFN-tau4 > IFN-tau6d > IFN-tau11), and induce an antiviral state (IFN-tau4 > IFN-tau6d = IFN-tau11). The present objective was to compare variants for differences in ability to inhibit proliferation of phytohemagglutinin-stimulated PBL. At equal concentrations, IFN-tau4 was more inhibitory than IFN-tau6d, IFN-tau11, or an IFN-omega control. Similar differences in potency were seen when IFN-tau variants were tested at equal antiviral concentrations. Thus, the sheep trophectoderm secretes variants of IFN-tau that differ in ability to regulate lymphocyte function. The nature of the effect of the trophectoderm on endometrial lymphocytes may depend on the relative amount of each variant produced.

Animals↗
PubMed2000

The effects of splenic artery ligation in an experimental model of secondary hypersplenism.

OBJECTIVE: To induce hypersplenism in rats by splenic vein ligation and to investigate the effects of splenic artery ligation in this model. BACKGROUND: Selective arterial embolisation and splenic artery ligation (SAL) are used in the treatment of secondary hypersplenism in some medical centres but these methods are not common. MATERIALS AND METHODS: Thirty male Saprague-Dawley rats were allocated to three groups (n = 10). The first group underwent laparotomy, the second and third groups underwent laparotomy and splenic vein ligation. At the end of the third week, laparotomy was performed in the first and second groups and splenic artery ligation in the third group. Erythrocyte, leukocyte and platelet counts were performed weekly. At the end of the sixth week, the animals were sacrificed and the spleens were taken for histopathologic examination. RESULTS: In the second and third groups, after splenic vein ligation, the erythrocyte and platelet counts were significantly reduced at the end of the second week (p < 0.01). In the second group, which underwent splenic vein ligation only, the levels remained low throughout the experiment. In the third group, after splenic artery ligation, there were rises in both erythrocyte and platelet counts; the levels were similar to the levels in the control group at three weeks after splenic artery ligation (p > 0.05). No significant changes were observed in the leukocyte counts throughout the experiment (p > 0.05). CONCLUSIONS: Splenic vein ligation successfully induces experimental secondary hypersplenism. This state can be ameliorated by splenic artery ligation.

Animals↗
PubMed1999

Effects of phentolamine on tissue perfusion in pediatric cardiac surgery.

OBJECTIVE: To evaluate whether the deleterious effects of cardiopulmonary bypass (CPB) can be overcome by phentolamine-induced pharmacologic vasodilation in pediatric patients with congenital heart disease. DESIGN: Prospective, randomized, clinical study. SETTING: Single university hospital. PARTICIPANTS: Forty-three pediatric patients undergoing open cardiac surgery for repair of congenital heart disease. INTERVENTIONS: Patients were randomly allocated into two groups. Patients in group 1 (n = 22) received 0.2 mg/kg of phentolamine during the cooling and rewarming periods of CPB. Group 2 patients (n = 21) did not receive phentolamine. Temperature measurements (rectal [R], nasopharyngeal [N], and toe [P]) and serum lactate values were obtained before, during, and after CPB; systemic oxygen consumption was evaluated during CPB. MEASUREMENTS AND MAIN RESULTS: At the end of the CPB period and at the end of the operation, lactate values of group 1 (1.87+/-0.37 and 1.8+/-0.39 mmol/L, respectively) were significantly lower than values of group 2 (2.24+/-0.28 and 2.33+/-0.33 mmol/L; p < 0.05 and p < 0.05, respectively). At the beginning of the rewarming period N-R temperature gradients of group 1 (0.14 degrees C+/-0.92 degrees C) were lower than group 2 (-0.58 degrees C+/-1.84 degrees C) values (p < 0.05). Central-peripheral temperature gradients of group 1 obtained at the end of the CPB period (N-R = 2.18 degrees C+/-0.69 degrees C; N-P = 7.84 degrees C+/-1.54 degrees C; R-P = 5.66 degrees C+/-1.70 degrees C) were significantly lower than the values of group 2 (N-R = 2.80 degrees C+/-0.91 degrees C, N-P = 9.97 degrees C+/-2.02 degrees C; R-P = 7.18 degrees C+/-2.10 degrees C; p < 0.05; p < 0.001; p < 0.05). At the end of the operation values of group 1 (N-R = 0.48 degrees C+/-0.31 degrees C; N-P = 6.30 degrees C+/-1.23 degrees C; R-P = 5.82 degrees C+/-1.16 degrees C) were significantly lower than the values of group 2 (N-R = 0.94 degrees C+/-0.56 degrees C; N-P = 8.69 degrees C+/-0.28 degrees C; R-P = 7.75 degrees C+/-2.15 degrees C; p < 0.05; p < 0.001; p < 0.001). The systemic oxygen consumption values of group 1 were higher than group 2 (6.26+/-1.82 v 5.17+/-1.05 mL/min/kg; p < 0.05) after complete rewarming. Mean arterial pressure (MAP) values of group 1 (58.9+/-6.4 mmHg) were lower than group 2 (63.4+/-6.7 mmHg) at the period after CPB (p = 0.03). CONCLUSION: The results suggest that the use of phentolamine during CPB is associated with limited systemic anaerobic metabolism and more uniform body perfusion.

Adrenergic alpha-Agonists↗
PubMed1998

Antiglutamatergic therapy in Alzheimer's disease--effects of lamotrigine. Short communication.

It has been proposed that excitotoxic damage by glutamatergic hyperactivity is responsible for neurodegeneration in Alzheimer's disease. Lamotrigine (LTG) inhibits presynaptic glutamate release and is considered to be effective in treatment of other neurodegenerative disorders by its cerebroprotective properties. We used LTG in 11 patients with the diagnosis of probable Alzheimer's disease. 300 mg/day administration of LTG improved word recognition, naming and depressed mood on Alzheimer Disease Assessment Scale (ADAS).

Aged↗
PubMed1997

Case of intracranial vertebral artery dissection in young age.

Stroke in childhood is rare and has its own characteristic findings. Vertebrobasilar ischemia due to trauma in this age group has been described, but its specific features have not yet been clearly defined. Dissection of vertebral artery is one of the causes of vertebrobasilar ischemia that is very uncommonly detected in the intracranial portion of the posterior circulation in childhood. We report a 14-year-old boy with a history of neck trauma and transient vertigo attacks who presented with brainstem and cerebellar ischemic findings. Due to the large left cerebellar infarct size compressing the fourth ventricle, we performed emergent posterior fossa decompression. Digital cerebral subtraction angiography revealed left vertebral artery dissection beginning at the V1 portion to the level of V4 and distal thrombosis of basilar artery. After 2 months, he was discharged from the hospital with minor neurologic deficit with anticoagulation therapy. Due to better outcome in childhood, early investigation for intracranial dissection should be included in the evaluation of posterior circulation infarcts in this age group.

Adolescent↗