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1.
Neuroimage ; 281: 120389, 2023 11 01.
Article in English | MEDLINE | ID: mdl-37751812

ABSTRACT

Frequency tagging has been demonstrated to be a useful tool for identifying representational-specific neuronal activity in the auditory and visual domains. However, the slow flicker (<30 Hz) applied in conventional frequency tagging studies is highly visible and might entrain endogenous neuronal oscillations. Hence, stimulation at faster frequencies that is much less visible and does not interfere with endogenous brain oscillatory activity is a promising new tool. In this study, we set out to examine the optimal stimulation parameters of rapid frequency tagging (RFT/RIFT) with magnetoencephalography (MEG) by quantifying the effects of stimulation frequency, size and position of the flickering patch. Rapid frequency tagging using flickers above 50 Hz results in almost invisible stimulation which does not interfere with slower endogenous oscillations; however, the signal is weaker as compared to tagging at slower frequencies so certainty over the optimal parameters of stimulation delivery are crucial. The here presented results examining the frequency range between 60 Hz and 96 Hz suggest that RFT induces brain responses with decreasing strength up to about 84 Hz. In addition, even at the smallest flicker patch (2°) focally presented RFT induces a significant and measurable oscillatory brain signal (steady state visual evoked potential/field, SSVEP/F) at the stimulation frequency (66 Hz); however, the elicited response increases with patch size. While focal RFT presentation elicits the strongest response, off-centre presentations do generally mainly elicit a measureable response if presented below the horizontal midline. Importantly, the results also revealed considerable individual differences in the neuronal responses to RFT stimulation. Finally, we discuss the comparison of oscillatory measures (coherence and power) and sensor types (planar gradiometers and magnetometers) in order to achieve optimal outcomes. Based on our extensive findings we set forward concrete recommendations for using rapid frequency tagging in human cognitive neuroscience investigations.


Subject(s)
Magnetoencephalography , Visual Cortex , Humans , Magnetoencephalography/methods , Evoked Potentials, Visual , Visual Cortex/physiology , Brain , Photic Stimulation/methods , Electroencephalography/methods
2.
Curr Biol ; 32(10): R479-R481, 2022 05 23.
Article in English | MEDLINE | ID: mdl-35609549

ABSTRACT

New research suggests that frontal midline theta EEG activity in humans controls activity in parietal cortex associated with memory maintenance. In turn, the speed of this frontal theta is modulated by the number of items to be handled, potentially indicating strong bidirectional communication within a fronto-parietal network.


Subject(s)
Memory, Short-Term , Parietal Lobe , Brain , Electroencephalography , Frontal Lobe , Humans , Theta Rhythm
3.
J Periodontal Res ; 55(6): 931-945, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32658361

ABSTRACT

OBJECTIVE: To assess the prevalence and severity of periodontitis based on different diagnostic methods in a historical Austrian population from the early middle ages. BACKGROUND: The description of the oral health status of archaeological material can provide interesting insights into prevalence, severity, and extent of oral diseases. Herein, the periodontal health status of the skeletal remains of medieval Avars (700-800 AD), which were considered as one of the earliest Avarian settlements in Austria, was investigated. METHODS: The skeletal remains of 128 Avars were examined; age and gender were estimated by standard forensic methods and tooth loss and root caries were recorded. Periodontitis was assessed by (a) measurement of the alveolar bone levels (ABL) and (b) evaluation of the interdental septa. RESULTS: A mean ABL of 4.8 mm was determined, root caries tended to accumulate in teeth with a higher alveolar bone loss, and on average, 6.2 teeth were lost antemortem. Independent of the diagnostic method >90% of the subjects were judged as periodontally diseased, and age and tooth type were significant predictors. However, on the tooth level the presence of periodontitis varied considerably depending on the diagnostic method; that is, 7.6% versus 47.2% of the teeth were judged as healthy based on ABL or interdental septa, respectively. CONCLUSION: The periodontal status of the skeletal remains of medieval Avars revealed a considerable high prevalence of periodontitis (ie, >90% of this population displayed periodontal tissue breakdown). However, the diagnostic method, disease definition, and data presentation should be considered when comparing results of archaeological material.


Subject(s)
Periodontal Diseases , Periodontitis , Tooth Loss , Austria/epidemiology , Female , History, Medieval , Humans , Male , Periodontal Diseases/epidemiology , Periodontal Diseases/history , Periodontitis/epidemiology , Periodontitis/history , Prevalence , Tooth Loss/epidemiology , Tooth Loss/history
4.
J Cancer Res Clin Oncol ; 146(6): 1473-1478, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32232656

ABSTRACT

PURPOSE: Classical type of lobular neoplasia (LN) spans a spectrum of disease, including atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS), classical lobular neoplasia (LN), and the three-tiered classification of lobular intraepithelial neoplasia (LIN-1, -2, -3). This study addressed inter-observer variability of classical lobular neoplasias (LN) (B3 lesions) in preoperative breast biopsies among breast and gynecopathologists METHODS: A retrospective, observational, cross-sectional study was conducted. 40 preoperative digital images of breast core/vacuum biopsies were analyzed by eight experienced breast- and gynecopathologists. Evaluation criteria were ALH, LCIS, LN classic, LIN-1, LIN-2, LIN-3, focal B3 (one focus), extensive B3 (> one focus). Kappa-index and Chi-square tests were used for statistics. Digital scanned slides were provided to each participant. Agreement between the categories was defined as at least six of eight (cut-off 75%) concordant diagnoses. RESULTS: The highest agreement between eight pathologists was reached using the category lobular neoplasia (LN, classical), 26/40 (65%) cases were diagnosed as such. Agreements in other categories was low or poor: 12/40 (30%) (ALH), 9/40 (22%) (LCIS), 8/40 (20%) (LIN-1), 8/40 (20%) (focal B3), 3/40 (7.5%) (LIN-2), and 2/40 (5%) (extensive B3). Chi-square-test (classical LN versus the other nomenclatures) was significant (p = 0.001137). CONCLUSION: Our data suggest that among Swiss breast pathologists, the most reproducible diagnosis for B3 lobular lesions is the category of classical LN. These data further support lack of consistent data in retrospective studies using different terminologies. Validation of reproducible nomenclature is warranted in further studies. This information is useful especially in view of retro- and prospective data analysis with different diagnostic categories.


Subject(s)
Breast Neoplasms/pathology , Breast/pathology , Carcinoma, Lobular/pathology , Gynecology , Observer Variation , Pathologists , Biopsy , Breast Neoplasms/diagnosis , Carcinoma, Lobular/diagnosis , Cross-Sectional Studies , Female , Humans , Preoperative Care , Reproducibility of Results , Retrospective Studies
5.
Neuroimage ; 166: 307-316, 2018 02 01.
Article in English | MEDLINE | ID: mdl-29117579

ABSTRACT

Forming episodic memories is often driven by top-down processes of allocating attention towards voluntarily remembering the details of an episode. This attention orientation is needed to make sure that information is encoded for later remembering. Here we designed an episodic long-term memory (LTM) EEG experiment where we examined brain oscillatory activity associated with attention allocation towards the temporal link between an item and its context. The remembering of this temporal conjunction is crucial for item-context binding and hence for the formation of episodic memories. Participants saw a background picture and a word in a central position on a computer screen and were instructed to memorise (a) the picture only, (b) the word, (c) both individually (i.e. ignoring their co-occurrence) and (d) both with them being presented together. Attention allocation towards item-context binding was associated with oscillatory alpha desynchronization in the upper alpha band (10-13 Hz) over dominantly left posterior brain areas. The results highlight the role of alpha desynchronization in voluntary attention allocation towards the temporal conjunction of item and its context in episodic binding and the involvement of posterior brain areas. The pattern of results suggest that they most likely reflect additional visual processes recruited by attentional mechanisms and do not tap into neural processes of item-context binding per se. Moreover, it indicates that the involvement of alpha oscillations in cognitive processes may be more complex.


Subject(s)
Alpha Rhythm/physiology , Attention/physiology , Cerebral Cortex/physiology , Cortical Synchronization/physiology , Memory, Episodic , Memory, Long-Term/physiology , Adolescent , Adult , Female , Humans , Male , Young Adult
6.
Am J Case Rep ; 18: 1160-1165, 2017 Nov 03.
Article in English | MEDLINE | ID: mdl-29097650

ABSTRACT

BACKGROUND Leiomyosarcoma is the most common primary malignancy of the inferior vena cava (IVC), and represents approximately 10% of primary retroperitoneal sarcomas. Leiomyosarcoma presents with non-specific symptoms, including abdominal pain or back pain. There is an increased incidence in immunosuppressed individuals. CASE REPORT An unusual presentation of IVC leiomyosarcoma is reported in a 46-year-old female patient infected with human immunodeficiency virus (HIV) who was on highly active antiretroviral therapy (HAART) and who had a normal CD4 count of 934, who presented with back pain. Magnetic resonance imaging (MRI) of the lumbar spine showed a mass of the IVC. Initial computed tomography (CT)-guided biopsy of the IVC mass was non-diagnostic. An IVC filter was inserted, and the patient was discharged home, but 20 days later, she returned to the hospital with worsening right flank pain. Laboratory tests showed acute renal failure, and a repeat CT scan showed IVC thrombus extending 5 cm superiorly. When compared with the previous CT, there was an extension of thrombus into both renal veins. Histopathology of a transjugular needle core biopsy showed a moderately differentiated leiomyosarcoma. The patient was transferred to a multidisciplinary sarcoma center for surgical resection, chemotherapy, and radiation therapy. CONCLUSIONS This report is of a rare case of IVC leiomyosarcoma in a middle-aged HIV-positive woman with a normal CD4 count. Leiomyosarcoma of the IVC is extremely rare, is often detected when advanced, and has a poor prognosis. This case report describes the clinical, imaging, surgical and histopathological findings of leiomyosarcoma of the IVC.


Subject(s)
HIV Infections/complications , Leiomyosarcoma/pathology , Vascular Neoplasms/pathology , Vena Cava, Inferior/pathology , Back Pain/etiology , Female , Humans , Middle Aged
7.
AACN Adv Crit Care ; 27(4): 379-393, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27959294

ABSTRACT

Delirium, the most frequent complication of hospitalized older adults, particularly in intensive care units (ICUs), can result in increased mortality rates and length of stay. Nurses are neither consistently identifying nor managing delirium in these patients. The purpose of this study was to explore ICU nurses' identification of delirium, actions they would take for patients with signs or symptoms of delirium, and beliefs about delirium assessment and management. In this cross-sectional study using qualitative descriptive methods guided by the theory of planned behavior, 30 ICU nurses' responses to patient vignettes depicting different delirium subtypes were explored. Descriptive and content analyses revealed that nurses did not consistently identify delirium; their actions varied in different vignettes. Nurses believed that they needed adequate staffing, balanced workload, interprofessional collaboration, and established policy and protocols to identify and manage delirium successfully. Research is needed to determine if implementing these changes increases recognition and decreases consequences of delirium.


Subject(s)
Attitude of Health Personnel , Critical Care Nursing/standards , Delirium/diagnosis , Delirium/nursing , Nursing Staff, Hospital/psychology , Practice Guidelines as Topic , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Delirium/epidemiology , Female , Health Knowledge, Attitudes, Practice , Humans , Incidence , Male , Middle Aged , Prevalence
9.
Front Psychol ; 7: 705, 2016.
Article in English | MEDLINE | ID: mdl-27242617

ABSTRACT

Working Memory and executive functioning deficits are core characteristics of patients suffering from schizophrenia. Electrophysiological research indicates that altered patterns of neural oscillatory mechanisms underpinning executive functioning are associated with the psychiatric disorder. Such brain oscillatory changes have been found in local amplitude differences at gamma and theta frequencies in task-specific cortical areas. Moreover, interregional interactions are also disrupted as signified by decreased phase coherence of fronto-posterior theta activity in schizophrenia patients. However, schizophrenia is not a one-dimensional psychiatric disorder but has various forms and expressions. A common distinction is between positive and negative symptomatology but most patients have both negative and positive symptoms to some extent. Here, we examined three groups-healthy controls, predominantly negative, and predominantly positive symptomatic schizophrenia patients-when performing a working memory task with increasing cognitive demand and increasing need for executive control. We analyzed brain oscillatory activity in the three groups separately and investigated how predominant symptomatology might explain differences in brain oscillatory patterns. Our results indicate that differences in task specific fronto-posterior network activity (i.e., executive control network) expressed by interregional phase synchronization are able to account for working memory dysfunctions between groups. Local changes in the theta and gamma frequency range also show differences between patients and healthy controls, and more importantly, between the two patient groups. We conclude that differences in oscillatory brain activation patterns related to executive processing can be an indicator for positive and negative symptomatology in schizophrenia. Furthermore, changes in cognitive and especially executive functioning in patients are expressed by alterations in a task-specific fronto-posterior connectivity even in the absence of behavioral impairment.

10.
J Clin Med Res ; 7(6): 417-21, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25883703

ABSTRACT

BACKGROUND: Transfusion-associated hyperkalemic cardiac arrest is a serious complication in patients receiving packed red blood cell (PRBC) transfusions. Mortality from hyperkalemia increases with large volumes of PRBC transfusion, increased rate of transfusion, and the use of stored PRBCs. Theoretically, hyperkalemia may be complicated by low cardiac output, acidosis, hyperglycemia, hypocalcemia, and hypothermia. In this study, we focus on transfusion-related hyperkalemia involving only medical intensive care unit (MICU) patients. METHOD: This prospective observational study focuses on PRBC transfusions among MICU patients greater than 18 years of age. Factors considered during each transfusion included patient's diagnosis, indication for transfusion, medical co-morbidities, acid-base disorders, K(+) levels before and after each PRBC transfusion, age of stored blood, volume and rate of transfusion, and other adverse events. We used Pearson correlation and multivariate analysis for each factor listed above and performed a logistic regression analysis. RESULTS: Between June 2011 and December 2011, 125 patients received a total of 160 units of PRBCs. Median age was 63 years (22 - 92 years). Seventy-one (57%) were females. Sixty-three patients (50%) had metabolic acidosis, 75 (60%) had acute renal failure (ARF), and 12 (10%) had end-stage renal disease (ESRD). Indications for transfusion included septic shock (n = 65, 52%), acute blood loss (n = 25, 20%), non-ST elevation myocardial infarction (NSTEMI) (n = 25, 20%) and preparation for procedures (n = 14, 11%). Baseline K(+) value was 3.9 ± 1.1 mEq/L compared to 4.3 ± 1.2 mEq/L post-transfusion respectively (P = 0.9). During this study period, 4% of patients developed hyperkalemia (K(+) 5.5 mEq/L or above). The mean change of serum potassium in patients receiving transfusion ≥ 12 days old blood was 4.1 ± 0.4 mEq/L compared to 4.8 ± 0.3 mEq/L (mean ± SD) in patients receiving blood 12 days or less old. Sixty-two patients (77.5%) that were transfused stored blood (for more than 12 days) had increased serum K(+); eight (17.7%) patients received blood that was stored for less than 12 days. In both univariate (P = 0.02) and multivariate (P = 0.04) analysis, findings showed that among all factors, transfusion of stored blood was the only factor that affected serum potassium levels (95% CI: 0.32 - 0.91). No difference was found between central and peripheral intravenous access (P = 0.12), acidosis (P = 0.12), ARF (P = 0.6), ESRD (P = 0.5), and multiple transfusions (P = 0.09). One subject developed a sustained cardiac arrest after developing severe hyperkalemia (K(+) = 9.0) following transfusion of seven units of PRBCs. Multivariate logistic regression showed linear correlation between duration of stored blood and serum K(+) (R(2) = 0.889). CONCLUSION: This study assesses factors that affect K(+) in patients admitted to MICU. Results from the study show that rise in serum K(+) level is more pronounced in patients who receive stored blood (> 12 days). Future studies should focus on the use of altered storage solution, inclusion of potassium absorption filters during transfusion and cautious use of blood warmer in patients requiring massive blood transfusions.

11.
PLoS One ; 10(4): e0122478, 2015.
Article in English | MEDLINE | ID: mdl-25898361

ABSTRACT

Symptoms of narcolepsy tend to arise during adolescence or young adulthood, a formative time in human development during which people are usually completing their education and launching a career. Little is known about the impact of narcolepsy on the social aspects of health-related quality of life in young adults. The purpose of this study was to examine relationships between health-related stigma, mood (anxiety and depression) and daytime functioning in young adults with narcolepsy compared to those without narcolepsy. Young adults (age 18-35) with narcolepsy (N = 122) and without narcolepsy (N = 93) were mailed a packet that included questionnaires and a self-addressed postage paid envelope. The questionnaire included demographic information and a composite of instruments including the SF 36, Functional Outcomes of Sleep Questionnaire (FOSQ), Fife Stigma Scale (FSS), Epworth Sleepiness Scale (ESS) and Hospital Anxiety and Depression Scale (HADS). Variable associations were assessed using descriptive statistics, ANOVA, Mann-Whitney U Test, correlations, stepwise multiple regression and path analysis. Young adults with narcolepsy perceived significantly more stigma and lower mood and health-related quality of life than young adults without narcolepsy (p<0.01). Health-related stigma was directly and indirectly associated with lower functioning through depressed mood. Fifty-two percent of the variance in functioning was explained by the final model in the young adults with narcolepsy. Health-related stigma in young adults with narcolepsy is at a level consistent with other chronic medical illnesses. Health-related stigma may be an important determinant of functioning in young adults with narcolepsy. Future work is indicated toward further characterizing stigma and developing interventions that address various domains of stigma in people with narcolepsy.


Subject(s)
Narcolepsy/psychology , Adolescent , Anxiety/epidemiology , Case-Control Studies , Cataplexy , Cross-Sectional Studies , Depression/epidemiology , Employment , Female , Humans , Male , Narcolepsy/epidemiology , Quality of Life , Social Stigma , Young Adult
12.
Biology (Basel) ; 4(1): 173-86, 2015 Mar 02.
Article in English | MEDLINE | ID: mdl-25738809

ABSTRACT

Anodal transcranial Direct Current Stimulation (tDCS) has been shown to be an effective non-invasive brain stimulation method for improving cognitive and motor functioning in patients with neurological deficits. tDCS over motor cortex (M1), for instance, facilitates motor learning in stroke patients. However, the literature on anodal tDCS effects on motor learning in healthy participants is inconclusive, and the effects of tDCS on visuo-motor integration are not well understood. In the present study we examined whether tDCS over the contralateral motor cortex enhances learning of grip-force output in a visually guided feedback task in young and neurologically healthy volunteers. Twenty minutes of 1 mA anodal tDCS were applied over the primary motor cortex (M1) contralateral to the dominant (right) hand, during the first half of a 40 min power-grip task. This task required the control of a visual signal by modulating the strength of the power-grip for six seconds per trial. Each participant completed a two-session sham-controlled crossover protocol. The stimulation conditions were counterbalanced across participants and the sessions were one week apart. Performance measures comprised time-on-target and target-deviation, and were calculated for the periods of stimulation (or sham) and during the afterphase respectively. Statistical analyses revealed significant performance improvements over the stimulation and the afterphase, but this learning effect was not modulated by tDCS condition. This suggests that the form of visuomotor learning taking place in the present task was not sensitive to neurostimulation. These null effects, together with similar reports for other types of motor tasks, lead to the proposition that tDCS facilitation of motor learning might be restricted to cases or situations where the motor system is challenged, such as motor deficits, advanced age, or very high task demand.

13.
Neurosci Lett ; 588: 114-9, 2015 Feb 19.
Article in English | MEDLINE | ID: mdl-25576699

ABSTRACT

Rhythmical brain activity in the range between four and eight Hz acquired over frontal-midline EEG recording sites - so called frontal-midline theta activity - is regarded as one of the most prominent neural signatures of sustained attention. It is reported to parametrically increase with cognitive load and is thought to be generated in medial prefrontal cortex. Here we explored the possibility of using anodal transcranial direct current stimulation over frontal sites to enhance frontal-midline theta activity and to increase sustained attention performance. We used a small preliminary sample to test a novel direct current stimulation electrode configuration by which we were able to significantly increase frontal-midline theta amplitude in a resting condition after the end of the stimulation period. Using standardised low resolution electromagnetic tomography analysis the effect in the surface EEG was localised to right prefrontal and left medial prefrontal brain areas. Transcranial direct current stimulation did, however, not have any impact on behavioural performance during a sustained attention task. This most likely was due to a very fast washout of the stimulation's after effect on theta activity. Although these are only preliminary results from a rather small sample, this study demonstrates that transcranial direct current stimulation can be used to rather selectively enhance frontal-midline theta amplitude.


Subject(s)
Brain/physiology , Theta Rhythm , Transcranial Direct Current Stimulation , Adult , Attention , Brain Mapping , Double-Blind Method , Female , Humans , Male , Young Adult
14.
Biology (Basel) ; 4(1): 1-16, 2014 Dec 24.
Article in English | MEDLINE | ID: mdl-25545793

ABSTRACT

Memory consists of various individual processes which form a dynamic system co-ordinated by central (executive) functions. The episodic buffer as direct interface between episodic long-term memory (LTM) and working memory (WM) is fairly well studied but such direct interaction is less clear in semantic LTM. Here, we designed a verbal delayed-match-to-sample task specifically to differentiate between pure information maintenance and mental manipulation of memory traces with and without involvement of access to semantic LTM. Task-related amplitude differences of electroencephalographic (EEG) oscillatory brain activity showed a linear increase in frontal-midline theta and linear suppression of parietal beta amplitudes relative to memory operation complexity. Amplitude suppression at upper alpha frequency, which was previously found to indicate access to semantic LTM, was only sensitive to mental manipulation in general, irrespective of LTM involvement. This suggests that suppression of upper EEG alpha activity might rather reflect unspecific distributed cortical activation during complex mental processes than accessing semantic LTM.

15.
Am J Health Syst Pharm ; 71(24): 2137-41, 2014 Dec 15.
Article in English | MEDLINE | ID: mdl-25465585

ABSTRACT

PURPOSE: A case of episodic hyperkalemia associated with daptomycin administration is reported. SUMMARY: A 46-year-old African-American woman was hospitalized for treatment of a shoulder abscess. Initially treated with i.v. vancomycin, the patient was switched to daptomycin 9 mg/kg i.v. (500 mg daily) after three days. On day 10 of daptomycin therapy, she was noted to have a serum potassium concentration of 5.4 meq/L, with an increase to 6.1 meq/L on day 11. Reversal of hyperkalemia was achieved with oral sodium polystyrene sulfonate and other agents, and daptomycin was withheld for one day, during which time the patient's serum potassium level normalized. One day after daptomycin therapy was resumed at a lower dose (7 mg/kg), the potassium concentration increased again (to 5.5 meq/L). With a further dosage reduction and continued administration of sodium polystyrene sulfonate, the patient completed the full course of daptomycin therapy. There was a close temporal relationship between daptomycin administrations and the serum potassium fluctuations; other potential causes of hyperkalemia were ruled out. Evaluation of this case using the algorithm of Naranjo et al. yielded a score of 6, indicating that the serum potassium elevations probably constituted an adverse reaction to daptomycin. A literature search identified no other reports of hyperkalemia associated with daptomycin use in a patient with normal renal function. CONCLUSION: A 46-year-old women with normal renal function developed hyperkalemia after receiving high-dose daptomycin therapy. The potassium levels normalized when daptomycin was withheld but increased again when the patient was rechallenged with the drug.


Subject(s)
Daptomycin/adverse effects , Hyperkalemia/chemically induced , Polystyrenes/administration & dosage , Skin Diseases, Bacterial/drug therapy , Abscess/drug therapy , Administration, Oral , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/adverse effects , Anti-Bacterial Agents/therapeutic use , Chelating Agents/administration & dosage , Chelating Agents/therapeutic use , Daptomycin/administration & dosage , Daptomycin/therapeutic use , Female , Humans , Hyperkalemia/drug therapy , Middle Aged , Polystyrenes/therapeutic use
16.
Crit Care Nurse ; 34(5): 27-42, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25274762

ABSTRACT

BACKGROUND: In patients receiving heparin infusions, variations in specimen collection technique may contribute to inaccurate measurements of activated partial thromboplastin time (aPTT). OBJECTIVES: To determine if there is a difference in aPTT results between specimens collected from a central venous access device (CVAD) compared with venipuncture in patients receiving heparin infusions. METHODS: Simultaneous blood samples (CVAD vs venipuncture) from 66 patients receiving continuous heparin infusions were compared. RESULTS: The mean aPTT difference (peripheral aPTT minus CVAD aPTT) was -7.3 seconds (P=.07). Neither length of time heparin was turned off (P=.18) nor waste volume (P=.32) was significantly associated with the difference in aPTT. The median aPTT difference when the CVAD specimen was obtained from the heparin infusion port was -20.5 seconds, compared with -0.1, -3.0, and -0.2 seconds for specimens from a port proximal to, distal to, or coterminal with the heparin infusion, respectively (P=.008). CONCLUSIONS: Use of this protocol resulted in similar aPTTs when the CVAD specimen was not obtained from the heparin infusion port. However, obtaining the specimen from the heparin infusion port resulted in significantly higher aPTT values.


Subject(s)
Anticoagulants/administration & dosage , Blood Specimen Collection/methods , Heparin/administration & dosage , Partial Thromboplastin Time , Phlebotomy/methods , Adult , Aged , Aged, 80 and over , Catheterization, Central Venous , Female , Humans , Infusions, Intravenous , Male , Middle Aged
17.
Biomed Res Int ; 2014: 936096, 2014.
Article in English | MEDLINE | ID: mdl-25013813

ABSTRACT

Functional meaning of oscillatory brain activity in various frequency bands in the human electroencephalogram (EEG) is increasingly researched. While most research focuses on event-related changes of brain activity in response to external events there is also increasing interest in internal brain states influencing information processing. Several studies suggest amplitude changes of EEG oscillatory activity selectively influencing cortical excitability, and more recently it was shown that phase of EEG activity (instantaneous phase) conveys additional meaning. Here we review this field with many conflicting findings and further investigate whether corticospinal excitability in the resting brain is dependent on a specific spontaneously occurring brain state reflected by amplitude and instantaneous phase of EEG oscillations. We applied single pulse transcranial magnetic stimulation (TMS) over the left sensorimotor cortex, while simultaneously recording ongoing oscillatory activity with EEG. Results indicate that brain oscillations reflect rapid, spontaneous fluctuations of cortical excitability. Instantaneous phase but not amplitude of oscillations at various frequency bands at stimulation site at the time of TMS-pulse is indicative for brain states associated with different levels of excitability (defined by size of the elicited motor evoked potential). These results are further evidence that ongoing brain oscillations directly influence neural excitability which puts further emphasis on their role in orchestrating neuronal firing in the brain.


Subject(s)
Electroencephalography/methods , Neurons/physiology , Sensorimotor Cortex/physiology , Transcranial Magnetic Stimulation/methods , Adult , Brain Mapping , Electric Stimulation , Evoked Potentials, Motor , Female , Humans
18.
Cogn Affect Behav Neurosci ; 14(4): 1340-55, 2014 Dec.
Article in English | MEDLINE | ID: mdl-24763921

ABSTRACT

In healthy humans, it has been shown that executive functions are associated with increased frontal-midline EEG theta activity and theta phase coupling between frontal and posterior brain regions. In individuals with schizophrenia, central executive functions are supposed to be heavily impaired. Given that theta phase coupling is causally involved in central executive functions, one would expect that patients with an executive function deficit should display abnormal EEG theta synchronization. We therefore investigated executive functioning in 21 healthy controls and 21 individuals with schizophrenia while they performed a visuospatial delayed match to sample task. The task required either high executive demands (manipulation of content in working memory [WM]) or low executive demands (retention of WM content). In addition, WM load (one vs. three items) was varied. Results indicated higher frontal theta activity for manipulation processes than for retention processes in patients with schizophrenia, as compared with healthy controls, independently of WM load. Furthermore, individuals with schizophrenia revealed a reduction in theta phase coupling during early stages of the delay period for retention, as well as for manipulation processes at high-WM loads. Deviations in theta phase coupling in individuals with schizophrenia were mainly characterized by aberrant fronto-posterior connections, but also by attenuated posterior connections during manipulation of high-WM load. To conclude, fronto-parietal theta coupling seems to be substantially involved in executive control, whereas frontal theta activity seems to reflect general task demands, such as deployment of attentional resources during WM.


Subject(s)
Alpha Rhythm/physiology , Executive Function/physiology , Memory Disorders/etiology , Memory, Short-Term/physiology , Schizophrenia/complications , Schizophrenic Psychology , Adult , Cerebral Cortex/physiopathology , Electroencephalography , Female , Humans , Male , Memory Disorders/diagnosis , Middle Aged , Neuropsychological Tests , Photic Stimulation , Psychiatric Status Rating Scales , Reaction Time , Schizophrenia/pathology , Visual Perception , Young Adult
19.
J Clin Med Res ; 5(1): 12-7, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23390470

ABSTRACT

BACKGROUND: Pancreatitis complicating HIV infection, even in the Highly Active Antiretroviral Therapy (HAART) era, remains a management challenge. We felt there is a need to discern patterns in the biochemical markers, radiological studies, co-infections, length of stay (LOS) in patients with HIV or AIDS AND pancreatitis. METHODS: This is a retrospective study conducted from June, 2008 to August, 2010 on patients admitted with acute pancreatitis to our hospital. We extracted and compared the following parameters: biochemical markers, HBV markers (surface antigen, core antibody and surface antibody), HCV antibody, radiological studies, and length of stay (LOS). The Balthazar Grade score was used to assess radiological severity of disease. We stratified the cohort into comparison subsets according to CD4 count. RESULTS: Ninety-four admissions met the criteria for HIV or AIDS AND pancreatitis; 67 unique patients comprised the cohort. Median age was 48 years (range, 23 to 60 years). Thirty seven (55%) were male, 30 (45%), female. Two third (n = 51) (76%) were African American. Known risk factors included a history of pancreatitis, 17 (25%); cholecystitis, 13 (19%); alcohol abuse, 25 (37%); Intravenous drug abuse, 18 (27%). Only 36 (38%) admissions were on HAART regimen. Biochemical features on admission were: WBC, 6,100/mm(3) (900 - 25,700); amylase, 152 U/L (30 - 1,344); lipase, 702.5 U/L (30 - 5,766), triglyceride, 65 mg/dL (57 - 400); glucose, 94 mg/dL (60 - 1,670); lactate, 2.3 mmol/L (1.09 - 5.49); AST, 61.5 U/L (9 - 1,950); LDH, 762 U/L (394 - 5,500); bicarbonate 19.5 mEq/L (3.3 - 82.7). Interestingly, 62% patients had normal pancreas on CT scan on admission. Of 67 individuals, hepatitis profile was available in 43, 21 (49%) were positive for HCV, 11 (26%) had markers for HBV. Four of 11 patients (36) with CD4 < 50 had evidence of persistent HBV (+core, -surface ab). Patients with CD4 < 200 have a median time for hospital course of 8 days (range 4 - 61 days) compare to 3 days in patients with CD4 > 200. P = 0.03 via t-test comparison. One patient with CD4 < 50 died due to acute pancreatitis. CONCLUSION: Pancreatitis remains a major cause of morbidity in HIV-infected individuals. This study has provided detailed features in the HAART therapy era about the clinical, biochemical and radiological features of pancreatitis. Half of our patients were positive for HCV; additionally, 36% with CD4 < 50 had persistent HBV. As opposed to earlier studies, we did not find a female predominance. Patients with CD4 < 200 had a 2.67-fold increase length of stay. Future studies are needed for a closer look on viral cofactors which might precipitate episodes of acute pancreatitis.

20.
Oncoimmunology ; 1(4): 529-530, 2012 Jul 01.
Article in English | MEDLINE | ID: mdl-22754774

ABSTRACT

Expression or release of immunosuppressive molecules may protect tumor cells from the recognition and destruction by the immune system. New findings indicate that colorectal tumors produce immunoregulatory glucocorticoids and thereby suppress immune cell activation. The nuclear receptor LRH-1 plays a critical role in the regulation of colorectal tumor proliferation and glucocorticoid synthesis.

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