Effect of heat treatment on the morphology of carbon fibers doped with Co2p nanoparticles.

ABSTRACT: Carbon fibers (CFs) decorated by Co2P nanoparticles and carbon nanotubes were prepared via needle-less electrospinning technique. Formation of catalytically active Co2P nanoparticles and growth of carbon nanotubes were monitored in open and closed sintering environment at different sintering exposure times. Higher porosity, important in the catalytic reaction for easier penetration of electrolyte into the CFs, was achieved by mixing two immiscible polymers with natrium dodecyl sulfate and subsequent heat treatment process. Structure and morphology of the prepared modified carbon fibers were characterized by XRD, SEM and TEM. The time of heat exposure at the sintering temperature of 1200 °C and closure of the sintering space showed distinct effect on the growth and shape of carbon nanotubes. SEM and Raman spectroscopy revealed that closure of the system led to the formation of carbon nanotubes with smaller diameters and less structural disorder. Comparing of as-prepared CFs revealed that CFs with Co2P sintered in the closed system exhibited the best electrocatalytic activity for hydrogen evolution reaction due to lower overpotential and smaller Tafel slope in acidic solution.

Processing of Emotions in Functional Movement Disorder: An Exploratory fMRI Study.

Background: Affective dysregulation and impaired cognitive control are implicated in the pathology of functional neurological disorders (FNDs). However, voluntary regulation of emotions has seldom been researched in this group of patients. We hypothesized that patients with FNDs use inefficient voluntary emotion regulation strategies and regulate emotional reactions via increased motor activation. Methods: Fifteen patients with functional movement disorder (FMD) and fifteen healthy subjects matched by age, sex, and education underwent an emotion regulation task in fMRI. For stimuli, we used neutral and negative pictures from the International Affective Picture System. There was no restriction on their emotion regulation strategy. Both patients and healthy subjects were asked about the strategies they had used in a post-scanning interview. Participant levels of depression, trait anxiety, and alexithymia were assessed. Results: There were no significant differences in the emotion regulation strategies used by patients and healthy subjects, nor in levels of reported alexithymia and depression. However, patients showed increased activation in several brain areas when observing negative pictures, notably in the post-central gyrus, precuneus, posterior cingulate cortex (PCC) and cerebellar vermis, and also in their emotion regulation condition, particularly in the precuneus and post-central gyrus. Alexithymia was negatively associated with left insular activation during the observation of unpleasant stimuli only in the patient group. Conclusions: Our findings may implicate areas associated with self-referential processing in voluntary emotional regulation and lower emotional awareness as having a role in patients with functional movement disorders. However, our findings must be replicated with larger sample.

Preparation, properties and anticancer effects of mixed As4S4/ZnS nanoparticles capped by Poloxamer 407.

Arsenic sulfide compounds have a long history of application in a traditional medicine. In recent years, realgar has been studied as a promising drug in cancer treatment. In this study, the arsenic sulfide (As4S4) nanoparticles combined with zinc sulfide (ZnS) ones in different molar ratio have been prepared by a simple mechanochemical route in a planetary mill. The successful synthesis and structural properties were confirmed and followed via X-ray diffraction and high-resolution transmission electron microscopy measurements. The morphology of the particles was studied via scanning electron microscopy and transmission electron microscopy methods and the presence of nanocrystallites was verified. For biological tests, the prepared As4S4/ZnS nanoparticles were further milled in a circulation mill in a water solution of Poloxamer 407 (0.5wt%), in order to cover the particles with this biocompatible copolymer and to obtain stable nanosuspensions with unimodal distribution. The average size of the particles in the nanosuspensions (~120nm) was determined by photon cross-correlation spectroscopy method. Stability of the nanosuspensions was determined via particle size distribution and zeta potential measurements, confirming no physico-chemical changes for several months. Interestingly, with the increasing amount of ZnS in the sample, the stability was improved. The anti-cancer effects were tested on two melanoma cell lines, A375 and Bowes, with promising results, confirming increased efficiency of the samples containing both As4S4 and ZnS nanocrystals.

Factors responsible for early postoperative mental alterations after bilateral implantation of subthalamic electrodes.

INTRODUCTION: Early postoperative mental changes are the most frequent problem after bilateral subthalamic electrode implantation. The study aims to find an association between them and factors related to patient, disease and surgery, including the size of the third ventricle as brain atrophy marker. MATERIAL AND METHODS: The study included 80 patients with bilateral subthalamic electrodes implanted for motor complications of Parkinson's disease (PD). Patients' age, disease and motor complications duration, medication, neuropsychological tests, surgical reports, third ventricle length (intercommissural distance) and width (intermammillary distance) were analysed. RESULTS: Early mental alterations requiring treatment were observed in 25.0% of patients with higher age being significant predictor. The duration of PD motor complications, L DOPA equivalent dose, DSR Mattis, third ventricle length and width were not statistically significant predictors. The incidence of postoperative mental alteration with intermammillary distance > 8 mm was 60%. The percentage of left sided electrodes implanted in anterior trajectory is significantly higher in patients with early mental changes. CONCLUSIONS: Higher age is a risk factor for early postoperative mental changes, but not disease, late motor complications duration and parameters describing third ventricular size except the excessive intermammillary distance. Left sided electrode implanted in anterior position is a risk factor.

Adsorption of cadmium(II) on waste biomaterial.

Significant increase of the adsorption ability of the eggshell biomaterial toward cadmium was observed upon milling, as is evidenced by the value of maximum monolayer adsorption capacity of 329mgg(-1), which is markedly higher than in the case of most "green" sorbents. The main driving force of the adsorption was proven to be the presence of aragonite phase as a consequence of phase transformation from calcite occurring during milling. Cadmium is adsorbed in a non-reversible way, as documented by different techniques (desorption tests, XRD and EDX measurements). The optimum pH for cadmium adsorption was 7. The adsorption process was accompanied by the increase of the value of specific surface area. The course of adsorption has been described by Langmuir, Freundlich and Dubinin-Radushkevich isotherms. The adsorption kinetics was evaluated using three models, among which the best correlation coefficients and the best normalized standard deviation values were achieved for the pseudo-second order model and the intraparticle diffusion model, respectively.

Subthalamic electrode implantation using the MicroDrive system and the importance of microrecording data.

OBJECTIVE: The aim of the paper was to describe the relationship of the anatomical and electrophysiological target for the subthalamic electrode implantation in Parkinson's disease patients defined as the best electrophysiological recordings from multiple paralel electrodes tracts with a target discrepancy explanation. BACKGROUND: Although microrecording is the standard in subthalamic stimulation, microelectrode monitoring prolongs surgical time and may increase the risk of haemorrhagic complications. The main purpose for the electrophysiological mapping is to overcome the discrepancy between the anatomical and electrophysiological targets. METHODS: Subthalamic electrodes were stereotactically implanted in 58 patients using microrecording by means of parallel electrodes at defined distances. The relationship of the final electrode to the anatomical trajectory, the subthalamic nucleus electrical activity length, and the relationship of right and left electrodes were analysed. RESULTS: The final electrode placement matched the anatomical trajectory in 53.4 % of patients on the right side, and 43.1 % of patients on the left side. The electrode position was symmetrical in 38.3 % of patients. The analysis of left and right electrode positions did not prove brain shift as the sole factor responsible for anatomy-functional discrepancy. Further, neither age, Parkinson's disease duration, or L-DOPA adverse effects were confirmed as responsible factors. CONCLUSIONS: The difference between the anatomical trajectory and the final electrode placement underlined the need for functional microelectrode monitoring. Brain shift is not the only causative factor for the difference (Tab. 7, Ref. 27).

Circulatory and adipose tissue leptin and adiponectin in relationship to resting energy expenditure in patients with chronic obstructive pulmonary disease.

Increases in resting energy expenditure (REE) likely contribute to weight loss in various chronic diseases. In chronic obstructive pulmonary disease (COPD), relationships between the ventilatory impairment and increased REE, and between disturbances in adipokines and weight loss were previously described. Therefore, we investigated serum levels and adipose tissue expression of leptin and adiponectin, and their relationships to REE in patients with COPD. In 44 patients with stable COPD (38 male; age 62.3+/-7.2 years), REE was assessed using indirect calorimetry. Subcutaneous adipose tissue samples were analyzed using real-time PCR. From underweight [n=9; body mass index (BMI) <20.0 kg.m(-2)], to normal weight-overweight (n=24, BMI=20.0-29.9 kg.m(-2)) and obese patients (n=11; BMI>/=30 kg.m(-2)), REE adjusted for body weight decreased (32.9+/-6.1 vs. 26.2+/-5.8 vs. 23.9+/-6.6 kcal.kg(-1).24 h(-1), p=0.006), serum levels and adipose tissue expression of leptin increased (p<0.001 for both), and serum and adipose tissue adiponectin decreased (p<0.001; p=0.004, respectively). REE was inversely related to serum and adipose tissue leptin (R=-0.547, p<0.001; R=-0.458, p=0.002), and directly to serum adiponectin (R=0.316, p=0.039). Underweight patients had increased REE compared to normal weight-overweight patients, in association with reductions in serum and adipose tissue leptin, and increased serum adiponectin, suggesting a role of adipokines in energy imbalance in COPD-related cachexia.

Dementia after DBS Surgery: A Case Report and Literature Review.

We report the case history of a 75-year-old woman with Parkinson's disease who developed severe cognitive problems after deep brain stimulation (DBS) of the bilateral subthalamic nuclei (STN). After a brief cognitive improvement, the patient gradually deteriorated until she developed full-blown dementia. We discuss the case with respect to the cognitive effects of STN DBS and the possible risk factors of dementia after STN DBS surgery.

Involvement of the subthalamic nucleus and globus pallidus internus in attention.

We studied the appearance of cognitive event-related potentials (ERPs) and event-related de/synchronizations (ERD/S) in the subthalamic nucleus (STN) and globus pallidus internus (GPi). We particularly focused on the rare non-target (distractor) stimuli processing. ERPs and ERD/S in the alpha and beta frequency range were analyzed in seven Parkinson's disease patients and one primary dystonia patient with implanted deep brain stimulation (DBS) electrodes. A visual three-stimulus protocol was used (frequent stimulus, target stimulus, and distractor). The non-target and distractor-related waveforms manifested similar shapes. A specific positive ERP peak around 200 ms and a low alpha frequency ERS were detected from the STN as a response to the distractor stimuli in six of the patients with Parkinson's disease and also in the primary dystonia patient's GPi. This positivity probably reflects an attentional orienting response to the distractor stimuli. The STN and GPi are probably involved in attentional cerebral networks.

The effect of cortical repetitive transcranial magnetic stimulation on cognitive event-related potentials recorded in the subthalamic nucleus.

We studied whether the cognitive event-related potentials (ERP) in the subthalamic nucleus (STN) are modified by the modulation of the inferior frontal cortex (IFC) and the dorsolateral prefrontal cortex (DLPFC) with repetitive transcranial magnetic stimulation (rTMS). Eighteen patients with Parkinson's disease who had been implanted with a deep brain stimulation (DBS) electrode were included in the study. The ERPs were recorded from the DBS electrode before and after the rTMS (1 Hz, 600 pulses) over either the right IFC (10 patients) or the right DLPFC (8 patients). The ERPs were generated by auditory stimuli. rTMS over the right IFC led to a shortening of ERP latencies from 277 +/- 14 ms (SD) to 252 +/- 19 ms in the standard protocol and from 296 +/- 17 ms to 270 +/- 20 ms in the protocol modified by a higher load of executive functions (both P < 0.01). The application of rTMS over the DLPFC and the sham stimulation over the IFC showed no significant changes. The shortening of ERP latency after rTMS over the right IFC reflected the increase in the speed of the cognitive process. The rTMS modulation of activity of the DLPFC did not influence the ERP. Connections (the IFC-STN hyperdirect pathway) with the cortex that bypass the BG-thalamocortical circuitries could explain the position of the STN in the processing of executive functions.

Pathogenesis of alcoholic neuropathy.

Chronic alcoholism is a medical, economical and social problem. Motility and mental function disorders are among the complications of chronic alcoholism and have been known for more than two centuries as "alcoholic paralysis", and are caused by alcoholic neuropathy. The pathogenesis of alcoholic neuropathy does not appear to be identical with central nervous system disorders which are caused by chronic alcoholism and it seems that it results from a failure of the protection barrier systems in the peripheral nervous system. To the pathogenesis of alcoholic neuropathy includes: 1. direct toxic effects of alcohol on the cellular population of the central nervous system and other tissues, especially of parenchymatous organs (in particular of the liver), 2. indirect metabolic and exotoxic changes mediated by malabsorption, maldigestion and secondary caloric and energy deprivation, 3. effects of genetic factors. (Fig. 2, Ref. 23.)

Is the spinal cord lesion rare in diabetes mellitus? Somatosensory evoked potentials and central conduction time in diabetes mellitus.

BACKGROUND: Diabetic neuropathy and autonomic nervous system neuropathy are recognized as the most common clinical pictures of nervous system disorders caused by DM, while the damage to the brain and the spinal cord is considered to be rare. The aim of this work is to indicate the importance of somatosensory evoked potentials (SEP) for the early diagnosis of nerve system damage related to diabetes mellitus. MATERIAL AND METHODS: We studied 20 patients (aged 35-50 years), with type 2 diabetes mellitus lasting for 5-10 years. The control group population comprised of 30 healthy individuals of the same median age. The spinal and cortical somatosensory evoked potentials (SEP) after stimulation of median and fibular nerves were examined in both groups of patients. We measured the latencies and amplitudes of individual wave deflections, peripheral and central conduction time (PCT and CCT) of spinal and cortical SEP. RESULTS: The examination proved and confirmed the elongation not only of peripheral conduction time but also of the central conduction time - especially in spinal cord structures. The spinal cord changes connected with decrease of myelinated fibers which are able of conduction from periphery have to be accepted. The comparison of CCT1 and CCT2 conduction times showed that in group of diabetic patients the spinal cord structures are responsible for prolongation CCT. CONCLUSIONS: We confirm that the use of somatosensory evoked potentials examination and conduction times measurement has the significance in the confirmation of inapparent lesion of the spinal cord in diabetics.

A novel inserted membrane technique for studies of mycorrhizal extraradical mycelium.

A simple "inserted membrane technique" (IMT) for sampling mycorrhizal extraradical mycelium (ERM) was developed as an alternative to the commonly used membrane filtration technique (MFT). The ERM of two types of mycorrhiza, orchid and arbuscular, was extracted by insertion of cellulose nitrate or cellulose acetate membrane filters (0.45-0.6 µm pore size) into the mycorrhizosphere of host plants. The membranes with adhered ERM were removed at harvest and stained with trypan blue for estimation of total hyphal length and with enzyme stains to indicate the viability of the ERM. There are two apparent advantages of the IMT over the MFT: (1) Samples were cleaner and easier to observe, particularly when the hyphae were stained for enzyme activities and (2) the ERM remained intact and, thus, was also suitable for observation of ERM morphology. There were statistically significant correlations between the lengths of ERM extracted from clinoptinolite using MFT and IMT for both mycorrhizal types tested, orchid mycorrhiza (r=0.63) and arbuscular mycorrhiza (r=0.80). Linear regression analysis indicated the best fit for the data obtained (P<0.05, n=14 for orchid mycorrhiza and P<0.001, n=26 for arbuscular mycorrhiza). Advantages of the new technique over other techniques for studying ERM are discussed.

Sequential intermediate high-dose therapy with etoposide, ifosfamide and cisplatin for patients with germ cell tumors.

Intermediate high dose VIP (etoposide, ifosfamide, cisplatin) achieved comparable efficacy and improved tolerance in comparison with high-dose chemotherapy plus PBSC in poor risk germ cell tumors. The aim of this study was to confirm the effectivity and tolerance of this regimen in clinical practice. Twenty-five consecutive patients, 9 previously untreated with poor prognosis and 16 relapsed, were treated with 1.6 VIP or 1.9 VIP+PBSC. A relative dose intensity of 1.6 VIP was used in 14 patients and 11 patients received the intensity of 1.9 VIP. Clinical response was achieved in 56% of patients. Fifty-eight percent of patients have survived more than 1 year and 44% more than 2 years. No significant difference was noted between previously treated and untreated patients, as well as between the patients on 1.6 VIP and 1.9 VIP, with the exception of improved 1-year survival of patients on 1.9 VIP. One of four cisplatin-refractory patients achieved durable partial remission with a normal level of tumor markers. Serious non-hematological toxicity was rare. Myelotoxicity of 1.9 VIP was less serious in comparison with 1.6 VIP regimen, but the difference was not significant. Sequential intermediate high-dose therapy is an effective and tolerable regimen for patients with poor risk germ cell tumor as well as for relapsed patients.

Carboplatin and cyclophosphamide in the treatment of metastatic seminoma.

Cisplatin-based chemotherapy is highly effective in advanced seminoma, but at the cost of a considerable toxicity. The response rate of carboplatin is comparable with cisplatin combinations but the relapse rate is higher. Our study assesses the efficacy and the toxicity of the combination of carboplatin and cyclophosphamide in patients with advanced seminoma. Nineteen consecutive patients received 6 cycles of intravenous cyclophosphamide 750 mg/m2 and carboplatin 350 mg/m2, repeated every 21 days. The overall objective response rate was 100%, 11 patients (58%) achieved a complete response and 8 patients (42%) showed a partial response. At median follow up of 4.2 years 3 patients (15%) relapsed. The 2-year disease-free survival and the overall survival are 72 and 94%, respectively. This outpatient treatment was well tolerated and the toxicity was mild. One patient had granulocytopenic fever and one patient had grade 3 cystitis. The combination therapy with carboplatin and cyclophosphamide is an effective and tolerable regimen in advanced seminoma.

Bacteremia in neutropenic versus nonneutropenic cancer patients: etiology and outcome in 401 episodes.

Etiology, risk factors, symptomatology and outcome of 401 bacteremic episodes during the period of 6 years in a National Cancer Institute occurring among 9987 admissions were analyzed. Neutropenia as an independent risk factor was observed in 198 episodes, while 203 bacteremic episodes appeared in nonneutropenic patients. Both groups were compared in risk factors, etiology, clinical symptomatology and outcome. Proportion of particular pathogens did not show significant differences in both groups, except for E. faecalis occurring more frequently in the group of nonneutropenic patients in contrast to Enterobacteriaceae, occurring more frequently in neutropenic patients. There was significant by higher proportion of anaerobic bacteremia and fungemia in neutropenic than in nonneutropenic patients. Prior prophylaxis with quinolones with breakthrough bacteremia were also seen more frequently in the group of neutropenic patients. Septic shock and death due to bacteremia occurred more frequently in the group of neutropenic patients.

Staphylococcal bacteremia in cancer patients: risk factors and outcome in 134 episodes prior to and after introduction of quinolones into infection prevention in neutropenia.

A total of 134 episodes of staphylococcal bacteremia (SBE) appearing among 9987 admissions, and 979 episodes of bacteremia in cancer patients within 5 years, were analyzed for risk factors, clinical course and outcome; 64 were monomicrobial and 70 polymicrobial. The most frequent risk factors were acute leukemia, catheter insertion, long-lasting neutropenia, and prior prophylaxis with quinolones. There was no significant difference between polymicrobial and monomicrobial SBE in risk factors. The two groups differed only in the source of bacteremia (gastrointestinal and respiratory-tract infections were more common in monomicrobial SBE) and etiology-Staphylococcus aureus appeared more frequently in monomicrobial than in polymicrobial bacteremia (20.3% compared to 4.3%, P < 0.05). More complications (14.3%) such as abscesses, endocarditis, etc. appeared in the group of polymicrobial SBE (P < 0.05). No difference was observed in clinical course and outcome between monomicrobial and polymicrobial SBE. The incidence of SBE has increased since 1991, when quinolones were first used in prophylaxis in afebrile neutropenia at our center; however, the infection-associated mortality in monomicrobial SBE was low (4.3%).

Etiology of bacteraemia in patients with various malignancies: is there association between certain antineoplastic drugs and microorganism?

The authors studied a relationship between particular bacterial or fungal organisms isolated from blood cultures and type of malignancy and antineoplastic drugs in 237 cancer patients. Sixty four had acute myelogenous leukemia (AML), 43 non-Hodgkin's lymphoma (NHL) and 140 solid tumors (ST). All patients had at least one positive blood cultures for one or more microorganism drawn during 1-10 days after cytotoxic chemotherapy, viridans streptococcal bacteremia was more frequently observed in patients with AML (12.5%) and NHL (27.9%) than ST (43%, p < 0.01 and 0.03). The incidence of anaerobic bacteria was similar in patients with NHL and ST, and in both groups significantly higher (p < 0.05) than in AML. Enterobacteriaceae caused bacteremia less frequently in patients with AML than in those with ST (12.5 vs 27.8%, p < 0.05). However, the highest incidence of Stenotrophomonas maltophilia bacteremia was seen in patients with AML (6.3% vs 2.3%, p < 0.04 and 0.03). Concerning fungemia, Candida albicans occurred significantly more frequently in blood cultures in patients with NHL, and molds in patients with AML. Cytarabine and metothrexate seems to be more frequently associated with viridans streptococci, cytarabine and mitoxanthrone with Stenotrophomonas maltophilia, B. fragilis with cisplatin and 5-fluorouracil, Fusarium spp., Mucorales and Aspergillus spp. with acute leukaemia (AL) treated with cytarabine and mitoxantrone. The association of other pathogens with an underlying disease or chemotherapeutic regimen could not be documented. (Tab. 1, Ref. 19.).

[Malignant cystosarcoma phyllodes: clinico-pathological conference in connection with two cases]. / Malignus cystosarcoma phyllodes: kliniko-patológiai áttekintés két eset kapcsán.

Clinical and morphological characteristics of two malignant cystosarcoma phyllodes mammae were reported with the review of recent literature. One of the patients went to see her doctor 2 years after she had noticed the tumour because of "problems in her family". In the removed giant fibroadenoma osteo-chondrosarcomatous transformation was found. The other patient tried "to mobilise her inner energies against the growth" for 3 years. The removed tumour weighed 2100 grams and there were metastases in the axillary lymph nodes. Histological examination showed malignant cystosarcoma phyllodes with vasoformative tendency. Electron microscopical studies confirmed in both cases that the tumors with varying structures originated from immature mesenchymal cells. Authors agree on wide extirpation of the tumour. According to the literature adjuvant chemo- or radiotherapy do not improve patients survival. In case of early radical operation the malignant transformation is less probable.