The effect of robot-assisted gait training frequency on walking, functional recovery, and quality of life in patients with stroke.

AIM: This study aims to investigate the effects of robot-assisted gait training (RAGT) frequency on walking, functional recovery, QoL and mood. METHODS: Sixty patients aged 50-75, diagnosed with post-stroke hemiplegia were entered into the retrospective analysis. Participants who scored maximum 3 on the Modified Rankin Scale and were diagnosed with moderate stroke according to The NIH Stroke Scale were included in the study. The participants in group 1 (G1) received only conventional treatment (CT), in group 2 (G2) participants received one session of RAGT per week in addition to the CT program, and group 3 (G3) received two sessions of RAGT per week in addition to the CT program. 6-min walk test (6-MWT), Barthel Index (BI), Stroke-Specific Quality of Life Scale (SSQoL), and Beck Depression Inventory (BDI) were recorded. RESULTS: Median change in SSQoL of G3 was significantly higher from median change of G1 (p < 0.05), and median change in BDI of G3 was significantly lower than median change of G1 (p < 0.05). Median change in BDI of G3 was also significantly lower from change of G2 (p < 0.05). CONCLUSION: Two weekly sessions of RAGT in addition to CT exhibit positive effects on QoL and mood but no additional contribution to functional status.

Halofuginone improves caustic-induced oxidative injury of esophagus in rats.

BACKGROUND: The aim of this study is to evaluate the anti-inflammatory and anti-fibrotic effects of halofuginone in caustic esophageal burn injury in rats. MATERIALS AND METHODS: Corrosive esophageal injury (CEI) was produced in male Wistar albino rats by instilling NaOH solution (1 ml, 37.5%) into the distal esophagus. Rats were decapitated on the 3rd day (early group) or 28th day (late group), and treated daily with either saline or halofuginone (100 µg/kg/day; i.p.), continued on alternate days after the third day. Histopathological evaluation and measurement of nitric oxide (NO), peroxynitrite (ONOO-) and oxygen-derived radicals by chemiluminescence (CL) were made in the distal 2 cm of the esophagus. Non-irrigated proximal esophageal samples were assessed for the levels of nuclear factor (NF)-κB, caspase-3, glutathione (GSH), malondialdehyde (MDA) and myeloperoxidase (MPO) activity. RESULTS: GSH, MDA, NF-κB and caspase-3 levels, and MPO activity in the proximal esophagus were not different among groups. Increased number of TUNEL (+) cells in the irrigated esophagus of the early and late caustic injury groups was reduced by halofuginone treatment. High microscopic damage scores in both early and late CEI groups were decreased with halofuginone treatment. NO, ONOO- and CL levels, which were elevated in the saline-treated early CEI group, were reduced by halofuginone treatment, but reduced NO and ONOO- levels in the late period of saline-treated group were increased by halofuginone. CONCLUSION: In addition to its anti-fibrotic effects, current findings demonstrate that halofuginone exerts antioxidant and anti-apoptotic actions and supports therapeutic potential for halofuginone in CEI-induced oxidative stress.

Neuroprotective Effect of Erythropoietin on Phenylhydrazine-Induced Hemolytic Hyperbilirubinemia in Neonatal Rats.

Neonatal unconjugated hyperbilirubinemia might cause severe bilirubin neurotoxicity in especially hemolytic conditions. The study aimed to elucidate the potential neuroprotective effects of erythropoietin (EPO) in hemolysis-induced hyperbilirubinemia. In newborn rats, hyperbilirubinemia secondary to hemolysis was induced by injecting with phenylhydrazine hydrochloride (PHZ) and rats were injected with either vehicle or EPO. At 54th hour of the PHZ injection, rats were decapitated. Serum levels of TNF-α, IL-1ß, IL-10, brain-derived neurotrophic factor (BDNF) and S100-B and brain malondialdehyde, glutathione levels and myeloperoxidase activities were measured. TUNEL staining and NF-κB expression were evaluated. As compared to control pups, in vehicle-treated PHZ group, TNF-α and IL-1ß levels, malondialdehyde level and myeloperoxidase activity were increased with concomitant decreases in IL-10 and glutathione. All EPO regimens reversed PHZ-induced alterations in IL-10, TNF-α, malondialdehyde and glutathione levels. Three-day-treatment abolished increases in myeloperoxidase activity and IL-1ß levels, while BDNF and S100-B were elevated. Increased TUNEL (+) cells and NF-κB expressions in the brain of PHZ group were reduced in the 3-day-treated group. EPO exerted anti-inflammatory effects on PHZ-induced neural damage in newborn rats, while the neuroprotection was more obvious when the treatments were repeated successively. The results suggest that EPO treatment may have a therapeutic potential in supporting neuroplasticity in the hyperbilirubinemic neonates.

Nesfatin-1 improves oxidative skin injury in normoglycemic or hyperglycemic rats.

Hyperglycemia is one of the major causes of suppressed angiogenesis and impaired wound healing leading to chronic wounds. Nesfatin-1 a novel peptide was reported to have antioxidant and anti-apoptotic properties. This study is aimed to investigate the potential healing-promoting effects of nesfatin-1 in non-diabetic or diabetic rats with surgical wounds. In male Sprague-Dawley rats, hyperglycemia was induced by intraperitoneal (ip) injection of streptozotocin (55 mg/kg). Under anesthesia, dorsum skin tissues of normoglycemic (n=16) and hyperglycemic rats were excised (2 × 2 cm, full-thickness), while control rats (n=16) had neither hyperglycemia nor wounds. Half of the rats in each group were treated ip with saline, while the others were treated with nesfatin-1 (2 µg/kg/day) for 3 days until they were decapitated. Plasma interleukin-1-beta (IL-1ß), transforming growth factor-beta (TGF-ß-1), IL-6 levels, and dermal tissue malondialdehyde (MDA), glutathione (GSH) levels, myeloperoxidase (MPO) and caspase-3 activity were measured. For histological examination, paraffin sections were stained with hematoxylin-eosin or Masson's trichrome and immunohistochemistry for vascular endothelial growth factor (VEGF) was applied. ANOVA and Student's t-tests were used for statistical analysis. Compared to control rats, skin MPO activity, MDA and caspase-3 levels were increased similarly in saline-treated normo- and hyperglycemic rats. Nesfatin-1 depressed MDA, caspase-3, MPO activity and IL-1ß with concomitant elevations in dermal GSH and plasma TGF-ß-1 levels. Histopathological examination revealed regeneration of epidermis, regular arrangement of collagen fibers in the dermis and a decrease in VEGF immunoreactivity in the epidermal keratinocytes of nesfatin-1-treated groups. Nesfatin-1 improved surgical wound healing in both normo- and hyperglycemic rats via the suppression of neutrophil recruitment, apoptosis and VEGF activation.

The neuroprotective and anti-apoptotic effects of melatonin on hemolytic hyperbilirubinemia-induced oxidative brain damage.

Melatonin exerts protection in several inflammatory and neurodegenerative disorders. To investigate the neuroprotective effects of melatonin in an experimental hemolysis-induced hyperbilirubinemia, newborn Sprague-Dawley rats (25-40 g, n = 72) were injected with phenylhydrazine hydrochloride (PHZ; 75 mg/kg) and the injections were repeated at the 24th hour. Rats were treated with saline or melatonin (10 mg/kg) 30 min before the first and second PHZ injections and 24 h after the 2nd PHZ injections. Control rats (n = 24) were injected with saline, but not PHZ. At sixth hours after the last injections of saline or melatonin, all rats were decapitated. Tumor necrosis factor (TNF)-α, IL-1ß, IL-10 and brain-derived neurotrophic factor (BDNF) and S100B levels in the plasma were measured. Brain tissue malondialdehyde (MDA), glutathione (GSH) levels and myeloperoxidase (MPO) activities were measured, and brain tissues were evaluated for apoptosis by TUNEL method. In the saline-treated PHZ group, hemoglobin, hematocrit levels were reduced, and total/direct bilirubin levels were elevated when compared to control group. Increased plasma TNF-α, IL-1ß levels, along with decreased BDNF, S100B and IL-10 values were observed in the saline-treated PHZ group, while these changes were all reversed in the melatonin-treated group. Increased MDA levels and MPO activities in the brain tissues of saline-treated hyperbilirubinemic rats, concomitant with depleted brain GSH stores, were also reversed in the melatonin-treated hyperbilirubinemic rats. Increased TUNEL(+) cells in the hippocampus of saline-treated PHZ group were reduced by melatonin treatment. Melatonin exerts neuroprotective and anti-apoptotic effects on the oxidative neuronal damage of the newborn rats with hemolysis and hyperbilirubinemia.

Poly(amidoamine) (PAMAM): An emerging material for electrochemical bio(sensing) applications.

Poly(amidoamine) (PAMAM) dendrimers have received attention due to their large surface areas with high concentration of functional end groups to bind biological material. They are monodisperse and hyper-branched polymers which include active functional groups outside its surface. These functional groups have been used for immobilizing the biorecognition molecules. They act as bioconjugating reagents and they have various applications in the fields of chemical and biochemical biosensors. Electrochemical techniques (amperometric, impedimetric, potentiometric, electrochemiluminescence) are useful for the determination of target molecules, with high sensitivity and selectivity. Dendrimer-modified enzyme biosensors, DNA biosensors, immunosensors and chemical sensors have been fabricated by using PAMAM dendrimer. This review provides a brief description of PAMAM dendrimers and its applications in biosensors and sensors. These sensors' limit of detection values are also compared in detail. Also this is the first review that assesses PAMAM dendrimers from the point of its usability in biosensor and sensor technologies.

A comparative study of short chain and long chain mercapto acids used in biosensor fabrication: A VEGF-R1-based immunosensor as a model system.

A novel impedimetric biosensor utilizing a biological receptor, vascular endothelial growth factor receptor-1 (VEGF-R1), was developed for the determination of vascular endothelial growth factor (VEGF). VEGF-R1 was covalently immobilized by coupling with 11-mercaptoundecanoic acid, which formed a self-assembled monolayer on gold electrodes. Cyclic voltammetry and electrochemical impedance spectroscopy techniques were employed to characterize the immobilization process and to detect VEGF. To successfully construct the biosensor current, the experimental parameters were optimized. A Kramers-Kronig transform was performed on the experimental impedance data. The results obtained provided a linear response range from 1 to 6 ng/mL human VEGF. The applicability of the biosensor developed to determine VEGF in a spiked artificial human serum sample was tested. The important parameters related with the biosensors fabricated by using two different mercapto acids were compared in terms of the self-assembly processes, the activation conditions of -COOH ends, linear ranges obtained for VEGF, repeatabilities and reproducibilities, and cleaning procedures. The results of this study revealed that the length of the mercapto acids used for biosensor fabrication considerably affected the analytical performance and the practicability of the preparation of the biosensor.

A review on impedimetric biosensors.

Electrochemical impedance spectroscopy (EIS) is a sensitive technique for the analysis of the interfacial properties related to biorecognition events such as reactions catalyzed by enzymes, biomolecular recognition events of specific binding proteins, lectins, receptors, nucleic acids, whole cells, antibodies or antibody-related substances, occurring at the modified surface. Many studies on impedimetric biosensors are focused on immunosensors and aptasensors. In impedimetric immunosensors, antibodies and antigens are bound each other and thus immunocomplex is formed and the electrode is coated with a blocking layer. As a result of that electron transfer resistance increases. In impedimetric aptasensors, impedance changes following the binding of target sequences, conformational changes, or DNA damages. Impedimetric biosensors allow direct detection of biomolecular recognition events without using enzyme labels. In this paper, impedimetric biosensors are reviewed and the most interesting ones are discussed.

Applications of commercial biosensors in clinical, food, environmental, and biothreat/biowarfare analyses.

The lack of specific, low-cost, rapid, sensitive, and easy detection of biomolecules has resulted in the development of biosensor technology. Innovations in biosensor technology have enabled many biosensors to be commercialized and have enabled biomolecules to be detected onsite. Moreover, the emerging technologies of lab-on-a-chip microdevices and nanosensors offer opportunities for the development of new biosensors with much better performance. Biosensors were first introduced into the laboratory by Clark and Lyons. They developed the first glucose biosensor for laboratory conditions. Then in 1973, a glucose biosensor was commercialized by Yellow Springs Instruments. The commercial biosensors have small size and simple construction and they are ideal for point-of-care biosensing. In addition to glucose, a wide variety of metabolites such as lactate, cholesterol, and creatinine can be detected by using commercial biosensors. Like the glucose biosensors (tests) other commercial tests such as for pregnancy (hCG), Escherichia coli O157, influenza A and B viruses, Helicobacter pylori, human immunodeficiency virus, tuberculosis, and malaria have achieved success. Apart from their use in clinical analysis, commercial tests are also used in environmental (such as biochemical oxygen demand, nitrate, pesticide), food (such as glutamate, glutamine, sucrose, lactose, alcohol, ascorbic acid), and biothreat/biowarfare (Bacillus anthracis, Salmonella, Botulinum toxin) analysis. In this review, commercial biosensors in clinical, environmental, food, and biowarfare analysis are summarized and the commercial biosensors are compared in terms of their important characteristics. This is the first review in which all the commercially available tests are compiled together.

Electrochemical biosensors for hormone analyses.

Electrochemical biosensors have a unique place in determination of hormones due to simplicity, sensitivity, portability and ease of operation. Unlike chromatographic techniques, electrochemical techniques used do not require pre-treatment. Electrochemical biosensors are based on amperometric, potentiometric, impedimetric, and conductometric principle. Amperometric technique is a commonly used one. Although electrochemical biosensors offer a great selectivity and sensitivity for early clinical analysis, the poor reproducible results, difficult regeneration steps remain primary challenges to the commercialization of these biosensors. This review summarizes electrochemical (amperometric, potentiometric, impedimetric and conductometric) biosensors for hormone detection for the first time in the literature. After a brief description of the hormones, the immobilization steps and analytical performance of these biosensors are summarized. Linear ranges, LODs, reproducibilities, regenerations of developed biosensors are compared. Future outlooks in this area are also discussed.

Applications of electrochemical immunosensors for early clinical diagnostics.

Cancer and cardiovascular diseases are the major threats to global health. Hence, there is a growing demand for a range of portable, rapid and low cost biosensing devices for the detection of these diseases. Electrochemical immunosensors are simple, rapid, reliable and inexpensive devices and they have sensitive detection limits to monitor both levels of the biomarkers in normal and patient serum. Due to the specific binding of antibody to its corresponding antigen, immunosensors based on antibody-antigen interaction are one of the most widely used analytical techniques in the quantitative detection of these diseases. The changed levels of markers in patients are associated with diseases. In this article the biosensors and biomarkers, which were commonly used in terms of monitoring the diagnosis and treatment of cancer and cardiac diseases, are reviewed. In addition, the developed biosensors are compared in terms of precision, reproducibility, regeneration, stability and specificity.