Curcumin ameliorates impaired insulin/IGF signalling and memory deficit in a streptozotocin-treated rat model

Increased serum insulin levels and reduced peripheral insulin activities seen in insulin resistance syndrome are associated with age-dependent cognitive impairment and Sporadic Alzheimer’s Disease (SAD), suggesting a disturbance in the insulin signalling system in the brain and possibly being one of the causes of dementia. Therefore, the streptozotocin (STZ)-induced animal may be an appropriate model for the investigation of SAD and related dementia. This study was designed to investigate the beneficial effect of Curcumin (CUR), a neuroprotective agent, on intracerebroventricular (ICV) STZ-induced cognitive impairment in rats. For this purpose, adult male Wistar rats were bilaterally ICV injected with STZ (3 mg/kg). An artificial cerebrospinal fluid (aCSF) was given to the control group (SHAM) instead of STZ on days 1 and 3. Learning and memory performance were assessed using the “passive avoidance task” and the “Morris water maze test”. After confirmation of acquisition impairment with these tests, the STZ group was divided into two subgroups: STZ + vehicle (Vh) and STZ + CUR. The rats in the SHAM and STZ + Vh groups were administered intraperitoneally with 0.5 ml Vh and the rats in the STZ + CUR group were treated intraperitoneally with CUR (300 mg kg⁻¹ day⁻¹ in Vh) for 10 days starting from the 25th day after STZ injection. The Morris water maze test was reapplied on the 35th day after STZ injection and all of the rats were sacrificed on day 36 for quantitation of IGF-1 and for histopathological evaluation. Rats in the STZ + CUR group were found to have a higher performance in cognitive tests than rats in the STZ + Vh group (P < 0.01). In parallel with the cognitive tests, IGF-1 levels were decreased in all of the STZ-injected groups (1.78 ± 0.34) compared to the SHAM group (3.46 ± 0.41). In contrast, CUR treatment significantly increased IGF-1 levels (P < 0.001). The degree of neuronal loss decreased after CUR treatment compared to the SHAM group (P < 0.02). These results clearly indicate that CUR treatment is effective in reducing the cognitive impairment caused by STZ in rats, and may be a potential therapeutic agent for altering neurodegeneration in SAD.     

Effects of irrigation temperature on heat control in vitro at different drilling depths

Purpose: Thermal injury during implant bed preparation has a major influence on implant osseointegration and survival. This study investigated the effectiveness of the temperature of the saline solution used for heat control during drilling.
Material and methods: Fresh frozen edentulous segments of bovine mandibles were sectioned into 12 × 6 cm pieces. Thermoresistors were placed 0.5 mm from the drilling cavity walls, at depths of 3, 7, and 12 mm. Signals from the three thermoresistors were analyzed using ORIGIN 5.0 software.
Results: The maximum temperatures during drilling without irrigation were 50.9, 47.4, and 38.1°C at depths of 3, 7, and 12 mm, respectively. With irrigation using saline at 25 and 10°C, the maximum temperatures at a depth of 12 mm were 37.4 and 36.3°C, respectively. All other measurements with both 25 and 10°C saline were below body temperature.
Discussion and conclusion: This experimental in vitro study showed that more heat was generated in the superficial part of the drilling cavity than at the bottom. Therefore, external irrigation at room temperature can provide sufficient cooling during drilling. Lower temperature saline was more effective in cooling the bone, and irrigation of the site should be continued between the drilling steps.     

Role conflict, role ambiguity, and burnout in nurses and physicians at a university hospital in Turkey

In many countries currently, health-care professionals experience burnout in their professional life. This study explored the relationship between burnout, and role conflict and role ambiguity in nurses and physicians at a university hospital in Turkey. The data were collected by questionnaires that included sociodemographic variables, Maslach's Burnout Inventory (MBI), and Rizzo's Role Conflict and Role Ambiguity Scales. Two hundred and fifty one health-care professionals (170 physicians and 81 nurses) responded to the survey. There was a strong positive correlation between the MBI and Rizzo's Role Conflict and Role Ambiguity Scales. The nurses showed significantly higher levels of role conflict, role ambiguity, and burnout compared to the physicians. A multiple regression analysis showed that role conflict and role ambiguity might help to explain the higher level of burnout experienced by the nurses compared to the physicians. Future research is needed to develop preventive measures for the burnout of health-care professionals.     

Plasma Concentrations of Isoniazid and Rifampin Are Decreased in Adult Pulmonary Tuberculosis Patients with Diabetes Mellitus

Plasma isoniazid and rifampin concentrations, but not pyrazinamide and ethambutol concentrations, were decreased by about 50% (P < 0.05) in diabetic pulmonary tuberculosis patients. The prevalences of subnormal plasma isoniazid, rifampin, pyrazinamide, and ethambutol concentrations were 49% or 100% (P < 0.01), 66% or 100% (P < 0.05), 30% or 50% (P = 0.198), and 32% or 21% (P = 0.742) in nondiabetic or diabetic tuberculosis patients, respectively. These data show that plasma concentrations of isoniazid and rifampin were greatly reduced in diabetic tuberculosis patients.     

Copeptin and cardiovascular disease: A review of a novel neurohormone

Neurohormones (NHs) in the cascade of the arginine vasopressin (AVP) system have drawn particular attention in the recent years. Copeptin, the C-terminal portion of provasopressin, is a novel NH of the AVP system, and is known to be co-released with AVP from hypothalamus (neurohypophysis). As a surrogate marker of the AVP system, copeptin has gradually replaced AVP in several clinical studies largely due to its structural and methodological advantages. Copeptin has been regarded as a marker of non-specific stress response, and has also been suggested to have clinical implications in a variety of non-cardiovascular (pneumonia, sepsis, etc.) and cardiovascular conditions (heart failure and acute coronary syndromes (ACSs, etc.)). However, current data on relation of copeptin with other cardiovascular conditions ( arrhythmias, etc.) are still insufficient. The present review primarily focuses on general features of copeptin, its general clinical implications, and specifically aims to cover its potential clinical value in a variety of cardiovascular conditions.     

Tobacco Education and Counseling in Obstetrics and Gynecology Clerkships: A Survey of Medical School Program Directors

The 16,000 medical students completing OB/GYN clerkship programs each year provide a unique opportunity to motivate and mentor students in facilitating tobacco cessation. To determine the scope of current tobacco teaching in obstetrics/gynecology (OB/GYN) education at US medical schools and to assess opportunities for including new tobacco teaching, a 28-question survey was administered to directors and assistant directors at US medical school OB/GYN clerkship programs. Surveys were completed at 71% of schools. Only 9% reported having at least 15 min of dedicated teaching time for improving tobacco cessation skills. Nearly three-fourths of respondents reported teaching students how to intervene to reduce smoking during a work-up in the OB/GYN clinic, but only 43% reported that students would know where to refer someone wishing to quit. Only a third of respondents reported teaching students both to intervene with and refer OB/GYN patients who smoke. These findings suggest that although medical students see many OB and GYN patients who smoke, they have few opportunities to learn comprehensive cessation skills during their clerkships.     

Magnification-corrected photodynamic therapy

Background To present a method for performing photodynamic therapy (PDT) with a constant predictable light fluence based on actual laser spot magnification. Methods A calibrated Gullstrand-type model eye with a scale of half circles in the centre of the artificial fundus was used for this study. The axial length of the model eye was set to different values ranging from 20 to 31 mm, and the actual laser spot magnification of four indirect condensing laser lenses were determined using a PDT laser unit. Results Equations for determining the actual laser spot magnification were calculated for each laser lens. The total change in laser spot magnification from hyperopia (axial length 20 mm) to myopia (axial length 31 mm) was −20% to +24.8% for Mainster Standard lens (Ocular Instruments Inc, Bellevue, Washington, USA), −15.7% to +27.7% for Mainster Wide Field lens (Ocular Instruments Inc), −16.3% to +33.1% for Volk Transequator lens (Volk Optical Inc, Mentor, Ohio, USA), and −19.2% to +24.4% for Volk PDT Laser lens (Volk Optical Inc). Conclusions Axial length of the eye has a considerable effect on PDT laser spot magnification when an indirect laser lens is used. By calculating the actual laser spot magnification in conjunction with knowledge of the true greatest linear dimension of the neovascular lesion, the clinician may be able to deliver a constant predictable amount of light fluence to the fundus independent of the axial length of the PDT treating eye. No Grant/Financial Support. The authors have no financial interest in any of the products discussed in this article.     

Results of fundus perimetry after resorbed premacular hemorrhages under the internal limiting membrane in 10 patients

BACKGROUND: During their acute phase, premacular hemorrhages under the internal limiting membrane induce an absolute scotoma. It is generally suspected that extravasal blood has a toxic effect on the neuroretina. The objective of this study is to investigate whether one can indeed detect sensoric defects after resorbed hemorrhages under the internal limiting membrane. MATERIALS AND METHODS: Our patient group consisted of 10 patients with resorbed premacular hemorrhages, which had been caused by either Vasalva-Manouver or arterial macroaneurysms. In order to avoid visual field defects due to other causes, patients with diabetes, retinal vein occlusion and glaucoma were excluded from this study. The investigation was carried out with the Scotometry Programme Vers. 2.01 of the Rodenstock Scanning Laser Ophthalmoscope. Furthermore, fundus photographs were taken. RESULTS: Under condition of no pre-existing retinal pathologies, no scotomas could be revealed at the site of the preretinal hemorrhage after full resorption. Relative or absolute scotomas could only be found in cases of pre-existing epiretinal gliosis, pigmentepitheliumdefect, persistent subretinal hemorrhages or scars. CONCLUSION: Since no sensoric defects of the retinal receptors could be detected, the hypothesis of the extravasal blood having a direct toxic effect on the neuroretina, could not be confirmed in this patient group.     

Leukoaraiosis in stroke patients

Pathogenesis of leukoaraiosis (LA) is not clearly understood and its significance in patients with stroke remains undetermined. In the Neurology Department of Ankara Hospital, computed tomography (CT) examination of brain was performed for various reasons in 288 patients. LA was detected in 178 patients by the use of brain CT. Patients with LA had a higher incidence of hypertension history (70.8%) when compared with the non-LA group (57.3%; p <.05). There was no statistically significant difference in terms of sex, mean age, smoking, diabetes mellitus, history of cerebrovascular disease, cardiac failure, ischemic cardiac disease between patients with and without LA. We showed that LA is related to hypertension but not related to age, diabetes mellitus, or cardiac disease in our patient population.     

Inhibition of human endothelial cell proliferation by ShIF, a vacuolar H(+)-ATPase-like protein

ShIF is a bone marrow stroma cell-derived factor originally identified to support proliferation of bone marrow cells in vitro. This protein shares high sequence homology to the yeast vacuolar H(+)-ATPase subunit, Vph1p, and the 116 kDa proton pump of the rat and bovine synaptic vesicle, Vpp1. We examined the function of ShIF in the proliferation of human umbilical vein endothelial cells (HUVEC). ShIF inhibited HUVEC proliferation in a dose-dependent manner. Recombinant ShIF added at 10 and 20 ng/ml inhibited HUVEC proliferation by 21.6 and 44.3%, respectively and increasing the concentration of ShIF to 100 ng/ml inhibited proliferation by as much as 55.5%. When HUVEC cells were cultured at various concentrations of ShIF in the presence of anti-ShIF antibody, the inhibitory effects of ShIF to HUVEC proliferation were abrogated by 89-91% indicating that the activity of ShIF to HUVEC was specific. HUVEC cultured in the presence of ShIF and bafilomycin, a specific inhibitor of ATPase, resulted to a 90% growth inhibition. Thus, ShIF may act as an antagonist to the ATPase complex by disrupting the production of cellular ATP thereby decreasing the ability of HUVEC to proliferate.