Embedding and Retrieving Private Metadata in Electrocardiograms

Due to the recent explosion of ‘identity theft’ cases, the safeguarding of private data has been the focus of many scientific efforts. Medical data contain a number of sensitive attributes, whose access the rightful owner would ideally like to disclose only to authorized personnel. One way of providing limited access to sensitive data is through means of encryption. In this work we follow a different path, by proposing the fusion of the sensitive metadata within the medical data. Our work is focused on medical time-series signals and in particular on Electrocardiograms (ECG). We present techniques that allow the embedding and retrieval of sensitive numerical data, such as the patient’s social security number or birth date, within the medical signal. The proposed technique not only allows the effective hiding of the sensitive metadata within the signal itself, but it additionally provides a way of authenticating the data ownership or providing assurances about the origin of the data. Our methodology builds upon watermarking notions, and presents the following desirable characteristics: (a) it does not distort important ECG characteristics, which are essential for proper medical diagnosis, (b) it allows not only the embedding but also the efficient retrieval of the embedded data, (c) it provides resilience and fault tolerance by employing multistage watermarks (both robust and fragile). Our experiments on real ECG data indicate the viability of the proposed scheme.

Total antioxidant capacity and total oxidant status in patients with major depression: Impact of antidepressant treatment

Aim:  The purpose of the present study was to investigate whether total antioxidant capacity (TAC) and total oxidant status (TOS) are associated with major depressive disorder (MDD) and to evaluate the impact of antidepressant treatment on TAC and TOS in MDD.
Methods:  Fifty-seven MDD patients and 40 healthy controls participated in the study. Serum TAC and TOS were measured both in patients and controls using Erel's methods. Patients were treated with antidepressant drugs for 12 weeks. The treatment course was evaluated using the Montgomery–Asberg Depression Rating Scale (MADRS) in all patients.
Results:  TOS and oxidative stress index (OSI) were higher ( P  = 0.0001 for both) and TAC was lower ( P  = 0.0001) in the MDD group compared with those of the controls. After 3 months of antidepressant treatment, TOS and OSI were decreased and TAC was increased compared with the pretreatment values ( P  = 0.0001, for all). Furthermore, there were significant positive correlations between the severity of the disease and serum TOS and OSI (r = 0.584, P  = 0.0001; r = 0.636, P  = 0.0001, respectively). A negative correlation was found between the severity of the disease and serum TAC (r = −0.553, P  = 0.0001) at the pre-treatment stage.
Conclusion:  Treatment administered for 3 months to MDD patients increases TAC while decreasing TOS and OSI.     

Do sodium channel blockers have neuroprotective effect after onset of ischemic insult?

OBJECTIVE: Cerebral ischemia causes a series of pathophysiologic events that may result in cerebral infarct. Some neurons are more vulnerable to ischemia, particularly pyramidal neurons in the hippocampal CA1 region. Pharmacologic intervention for treatment of cerebral ischemia aims to counteract secondary neurotoxic events or to interrupt the progression of this process. In the present study, we compare the neuroprotective effects of sodium channel blockers (mexiletine, riluzole and phenytoin) and investigate whether they have neuroprotective effect when given after ischemic insult. METHODS: A transient global cerebral ischemia model was performed in this study by clipping bilateral common carotid arteries during 45 minutes. Riluzole (8 mg/kg), mexiletine (80 mg/kg) and phenytoin (200 mg/kg) were injected into the rats intraperitoneally 30 minutes before or after reperfusion. Lipid peroxidation levels and cerebral water contents were evaluated 24 hours after ischemia. Histopathologic assessment of hippocampal region was determined 7 days after ischemia. RESULTS: Riluzole, mexiletine and phenytoin treatment after global ischemia significantly decreased water content of the ischemic brain (p<0.05 for each). No significant difference was observed in cerebral edema among the drug treatment groups (p>0.05). When pre-treatment and post-treatment groups were compared with each other, only riluzole pre-treatment group revealed better result for cerebral edema (p<0.05). Pre-treatment with these drugs revealed significantly better results for the malonyldialdehyde (MDA) level and the number of survival neuron on the hippocampal region than the post-treatment groups. CONCLUSION: It is demonstrated that riluzole, mexiletine and phenytoin are potent neuroprotective agents in the rat model of transient global cerebral ischemia, but they are more effective when given before onset of the ischemia.     

Does pinealectomy affect the recovery rate after spinal cord injury?

Previous reports documented demonstrated that melatonin, a free radical scavenger, is important in protecting against oxidative stress-induced tissue damage after spinal cord injury (SCI). This study was undertaken to investigate the effects of pinealectomy (PX) and administration of exogenous melatonin after SCI in rats. These animals were randomized into six groups, each having 12 rats. Group 1 underwent laminectomy alone. Group 2 underwent laminectomy followed by SCI and received no medication. Group 3 underwent laminectomy followed by SCI and received melatonin. Group 4 underwent PX and laminectomy alone. Group 5 underwent PX and laminectomy followed by SCI and received no medication. Group 6 underwent PX and laminectomy followed by SCI and received melatonin. Melatonin (100 mg/kg) was given intraperitoneally immediately after trauma to the rats in the groups 3 and 6. PX caused a significant increase in the malondialdehyde (MDA), nitrite oxide (NO), glutathione (GSH), xanthine oxidase (XO) levels and decrease in GSH levels as compared with the control group. Trauma to the spinal cord results in significantly higher oxidative stress. Melatonin administration significantly reduced MDA, XO and NO levels, and increased GSH levels in the spinal cord after trauma. Exogenous melatonin treatment after trauma attenuated tissue lesion area and accelerated motor recovery rate. These findings suggest that reduction in endogenous melatonin after PX makes the rats more vulnerable to trauma and exogenous melatonin administration has an important neuroprotective effect on the level of the spinal cord.     

Effect of prenatal exposure to an anti-inflammatory drug on neuron number in cornu ammonis and dentate gyrus of the rat hippocampus: a stereological study

Prenatal exposed to an anti-inflammatory drug is a major problem for the developing central nervous system. It is not well known the effect of prenatal exposed to a non-steroidal anti-inflammatory drug on the hippocampus. Total neuron number in one side of the cornu ammonis (CA) and gyrus dentatus (GD) of the hippocampal formation in control and drug-treated (diclofenac sodium, DS) groups of male rats was estimated using the optical fractionator technique. Each main group has also two subgroups that are 4 weeks old (4W-old) and 20 weeks old (20W-old). In CA, no significant difference between 4W-old DS-treated and their control was found, but a significant difference was observed between 20W-old DS-treated and their controls. A decreasing of neuron number was 12% for 20W-old DS-treated group. In GD, a decreasing of the granule cell number in 4W-old of DS-treated group was seen but an increasing of granule cell number was found in the 20W-old drug-treated rats in comparison to its control group, 7% and 9%, respectively. Although an increasing of neuron number in CA at the control group was seen with age, from 4th week to 20th week (10%), age-dependent substantial granule cell decline (17%) was observed in GD. No age effect on the total cell numbers of CA and GD of the drug-treated groups was seen in comparison to 4W-old week and 20W-old. A pronounced neuron loss observed in the drug-treated group may be attributed to the neurotoxicity of diclofenac sodium (DS) on the developing hippocampal formation. Age-dependent neuron increase in the CA of 20W-old and neuron decline in GD of 20W-old control groups may be a result of a dual effect of saline injection during the fetal life, since these animals were exposed to a stress of 15-day-period of saline injection, prenatal stress. The reason of no age effect on CA and GD cell number in the drug-treated groups may be attributed to the depletion of the progenitor cells due to neurotoxicity of DS in the fetal life of these animals.     

Effect of chronic treatment of haloperidol on the rat liver: a stereological and histopathological study

Haloperidol is commonly used in therapy for patients with acute and chronic schizophrenia. Because it can have some adverse effects on specific target organs such as the liver, we analyzed whether haloperidol exerts a toxic effect on rat liver by means of stereological and histopathological methods. Fifteen adult male rats, divided into three groups, were used in the experiments. Once a day for 6 weeks, either saline or 0.4 or 0.8 mg kg⁻¹ doses of haloperidol were given interperitoneally to the control, low-dose, and high-dose groups, respectively. At the end of the experiment, rats were killed by an overdose of a general anesthetic, and the livers were dissected out, fixed for sectioning, and evaluated using stereological and histopathological methods. Hepatocyte numbers were found to be 271.672, 291.072, and 238.415 hepatocytes per cubic millimeter in the liver of the control, low-dose, and high-dose groups, respectively. The differences between high-dose and control groups and also between high-dose and low-dose groups were significant (p < 0.05). Our histopathological findings at both the structural and the ultra-structural level were confirmed by stereological estimations. Results suggest a relationship between haloperidol dose and toxic effects on the liver, and they indicate that a high dose of haloperidol may result in irreversible liver damage. This research was conducted in the Laboratory of Pharmacology at Ataturk University, School of Medicine, 25240 Erzurum/Turkey and the Laboratory of Histology and Embryology, School of Medicine, at Ataturk University, 25240 Erzurum/Turkey. None of the authors has a commercial interest, financial interest, and/or other relationship with manufacturers of pharmaceuticals, laboratory supplies, and/or medical devices or with commercial providers of medically related services.     

Anxiety and depression in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) mostly follows a painful, progressively disabling course, and individuals with RA experience more psychological distress than healthy individuals. The objective of the present study is to examine the prevalences of accompanying anxiety and depression in RA cases. The study included 82 RA cases and 41 age- and sex-matched healthy volunteers as the control group. Psychiatric examinations of all cases of the patient and control groups were performed according to DSM-IV criteria. Hamilton Anxiety Scale or Hamilton Depression Scale was applied to those who were found to have anxiety or depression. Total prevalence of anxiety, depression, and mixed anxiety-depressive disorder was found to be 70.8% (n=58) in the patient group and 7.3% (n=3) in the control group, and the difference was significant (p<0.001). Of the RA patients, 41.5% (n=34) was found to have depression, 13.4% (n=11) anxiety, and 15.9% (n=13) mixed anxiety-depressive disorder. The disease duration in patients with anxiety was shorter than the RA patient with depression (p<0.05). The disease duration was positively correlated with the degree of depression and negatively correlated with the degree of anxiety (r=0.341, p<0.05; r=−0.642, p<0.05, respectively). The results of our study suggest that prevalences of anxiety and mainly depression, increase in RA cases. When the clinical picture in RA cases becomes complicated with anxiety or depression, some problems at patients’ adaptation and response to treatment may be possible. RA cases should be monitored for accompanying anxiety or depression during follow-up.     

Subclavian artery pseudoaneurysm in Behcet’s disease

Behcet’s disease (BD) is an autoimmune, multisystemic, and chronic inflammatory disease. Although it affects all systems, involvement of the vascular system is of vital importance. Pseudoaneurysm ruptures in the arteries are the major causes of sudden deaths in BD. Although pseudoaneurysms in aorta and pulmonary arteries are rare, it is even more rare in the subclavian arteries. In our case, a pulsatile mass in the right clavicular area was determined to be associated with BD and this case is presented because subclavian artery pseudoaneurysm is seen rarely in BD.