Acute hypoxemia does not increase blood fibrinolytic activity in man

The influence of acute hypoxemia on blood fibrinolytic activity was investigated in 12 healthy males. Physiologically significant hypoxemia was produced by inspiration of 13% oxygen for 30 min. Six healthy males were exposed to hypoxemia at rest and 6 males to hypoxemia during exhaustive physical exercise on an ergocyclometer. During control experiments both groups of health males inspired 21% oxygen. In 5 patients with manifest respiratory insufficiency the effect of hypoxemia at rest was studied during withdrawal of oxygen treatment for up to 2.5 hours. No increase in fibrinolytic activity (measured with euglobulin clot lysis and fibrin plates) due to hypoxemia was observed either in resting healthy males or in patients. In healthy males the increase in fibrinolytic activity after physical exercise at 13% oxygen was even somewhat lower compared to 21% oxygen. No changes in other hemostatic parameters (activated partial thromboplastin time, factor VIII-related antigen, fibrinogen, plasminogen, alpha-2-antiplasmin, fibrin(ogen) degradation products) that could be attributed to hypoxemia, were observed in any group tested. It was concluded that short-term acute hypoxemia does not increase blood fibrinolytic activity in man.     

Dihydropyridine actions on calcium currents of frog sympathetic neurons.

Dihydropyridines (DHPs) generally have little effect on whole-cell calcium currents of neurons, even at concentrations far higher than those effective on muscle. Either neuronal calcium currents are much less sensitive to DHPs, or only a small proportion of the current is DHP-sensitive. We find that DHP agonists and antagonists act at low concentration on calcium currents in frog sympathetic neurons but that the effects are small even at optimal concentrations. The half-maximal dose (EC50) of the agonist Bay K 8644 is approximately 50 nM, and the effect of Bay K 8644 is blocked by 50% at approximately 300 nM nifedipine, from a holding potential of -80 mV. Nifedipine is more effective from a holding potential of -50 mV. These results suggest the presence of an L-type calcium current, with DHP sensitivity similar to L-currents in cardiac muscle. The predominant (greater than 90%) calcium current in frog sympathetic neurons is a DHP-resistant N-type current. However, high concentrations of DHPs (10 microM) partially block N-type calcium current, as well as voltage-dependent sodium and potassium currents.     

Brain activity during walking: A systematic review

BackgroundThis systematic review provides an overview of the literature deducing information about brain activation during (1) imagined walking using MRI/fMRI or (2) during real walking using measurement systems as fNIRS, EEG and PET.MethodsThree independent reviewers undertook an electronic database research browsing six databases. The search request consisted of three search fields. The first field comprised common methods to evaluate brain activity. The second search field comprised synonyms for brain responses to movements. The third search field comprised synonyms for walking.Results48 of an initial yield of 1832 papers were reviewed. We found differences in cortical activity regarding young vs. old individuals, physically fit vs. physically unfit cohorts, healthy people vs. patients with neurological diseases, and between simple and complex walking tasks.ConclusionsWe summarize that the dimension of brain activity in different brain areas during walking is highly sensitive to task complexity, age and pathologies supporting previous assumptions underpinning the significance of cortical control. Many compensation mechanisms reflect the brain's plasticity which ensures stable walking.     

Physical activity in patients with deep venous thrombosis: a systematic review

Objectives

We performed a systematic review to assess the benefits or risks of physical activity in patients with an acute or previous DVT of the leg.

Data sources

PubMed, EMBASE and Science Citation Index were searched without language restrictions up to July 2007. Bibliographies of retrieved articles and personal files were also searched.

Review methods

Randomized trials and prospective cohort studies that included patients with acute or previous DVT, described an exercise intervention or exercise exposure, and described any related clinical outcome were selected. Data were independently extracted by 2 investigators.

Results

Seven randomized trials and two prospective observational studies were included. Early exercise, compared with bed rest, was associated with a similar short-term risk of pulmonary embolism in patients with acute DVT and led to more rapid resolution of limb pain. In patients with acute DVT, a 6 month daily walking program led to similar degrees of vein recanalization and improvement in quality of life as controls. In patients with previous DVT, 30 min of vigorous treadmill exercise did not worsen venous symptoms and improved calf muscle flexibility; a 6 month exercise training program improved calf muscle strength and pump function; and high levels of physical activity at one month tended to be associated with reduced severity of postthrombotic symptoms during the subsequent 3 months.

Conclusions

Early walking exercise is safe in patients with acute DVT and may help to reduce acute symptoms. Exercise training does not increase leg symptoms acutely in patients with a previous DVT and may help to prevent or improve the postthrombotic syndrome.     

Physical activity and dietary interventions in diabetic neuropathy: a systematic review

Clinical Autonomic Research - Diabetic neuropathy is a common and disabling disorder, and there are currently no proven effective disease-modifying treatments. Physical activity and dietary...     

Residents-as-teachers programs in psychiatry: a systematic review.

OBJECTIVES: Because psychiatry residents have important roles as teachers and significant opportunities to contribute to medical student education, we set out to: identify all randomized control trials (RCT) for residents' teaching skills programs in psychiatry and to identify the efficacy of those interventions for improving teaching skills; identify the strengths and weaknesses of the available studies across medical disciplines; and identify currently available methods for enhancing residents' teaching skills for residents training in psychiatry. METHODS: The published English-language literature was searched using PubMed, Social Sciences Index, and PsycINFO databases, with key search words including: residents, teaching skills, residents as teachers, psychiatry, and assessments. Both RCT and controlled, nonrandomized trials of residents' teaching programs directed to enhance residents' teaching skills were selected and critically appraised. RESULTS: Of 13 trials identified and reviewed, most included residents in internal medicine. Only one included psychiatry residents and assessed their ability to teach interviewing skills to medical students. Along with other studies, this study demonstrated improvement in residents' teaching skills. Overall, interventions and outcome measures were heterogeneous while the quality of methodologies varied. Five studies were of higher quality, representing examples of quality educational research. Several described group differences, blinding, good follow-up, and use of valid, reliable tools. CONCLUSIONS: Only one trial exists that incorporated psychiatry residents. Significant opportunity to advance educational research in this field exists. Psychiatry residency program directors should incorporate high-quality methodologies and can benefit from the findings of trials in other disciplines.     

Treatment of child neglect: a systematic review.

OBJECTIVE: Child neglect is the most common type of child maltreatment. Our objective was to systematically evaluate the available evidence regarding the effectiveness of child neglect treatment programs, including those focused on victims of childhood neglect and (or) their caregivers. METHOD: We comprehensively searched the Medline, Psycinfo, and Eric databases from January 1980 to May 2003. Two authors independently reviewed 54 studies that met inclusion criteria. Fourteen articles met our design criterion and were assessed for their methodological quality according to guidelines developed by the US Preventive Services Task Force. RESULTS: Of the 14 studies included in the review, 2 were rated as good, and 3 were rated as fair. We found evidence that 2 specific types of play therapy and a therapeutic day treatment program had beneficial effects for children. Further, parents and children in families where neglect had occurred showed improvement with multisystemic therapy. CONCLUSIONS: Rigorous studies of treatments for neglected children and their families are lacking. Well-designed and well-conducted evaluations are urgently required to identify effective treatments, which should then be made available to children and their caregivers.     

Intracellular calcium increase in epileptiform activity: modulation by levetiracetam and lamotrigine

PURPOSE: Alterations in neuronal calcium (Ca2+) homeostasis are believed to play an essential role in the generation and propagation of epileptiform events. Levetiracetam (LEV) and lamotrigine (LTG), novel antiepileptic drugs (AEDs), were tested on epileptiform events and the corresponding elevations in intracellular Ca2+ concentration ([Ca2+]i) recorded from rat neocortical slices. METHODS: Electrophysiological recordings were performed from single pyramidal neurons from a slice preparation. Spontaneous epileptiform events consisting of long-lasting, repetitive paroxysmal depolarization shifts (PDSs) and interictal spike activity were induced by reducing the magnesium concentration from the solution and by adding bicuculline and 4-aminopyridine. Simultaneously, microfluorimetric measurements of [Ca2+]i were performed. Optical imaging with Ca2+ indicators revealed a close correlation between Ca2+ transients and epileptiform events. RESULTS: Both LEV and LTG were able to reduce both amplitude and duration of PDSs, as well as the concomitant elevation in [Ca2+]i, in a dose-dependent fashion. Whole-cell patch-clamp recordings from isolated neocortical neurons revealed that LEV significantly reduced N-, and partially P/Q-type high-voltage-activated (HVA) Ca2+ currents, whereas sodium currents were unaffected. Interestingly, the inhibitory effects of LEV were mimicked and occluded by LTG or by a combination of omega-conotoxin GVIA and omega-agatoxin IVA, selective blockers of N- and P/Q-type HVA channels, respectively, suggesting a common site of action for these AEDs. CONCLUSIONS: These results demonstrate that large, transient elevations in neuronal [Ca2+]i correlate to epileptiform discharges. The antagonistic effects of LEV and LTG on [Ca2+]i overload might represent the basis for their anticonvulsant efficacy and could preserve neuronal viability.     

The diurnal increase in euglobulin fibrinolytic activity in women using oral contraceptives and in normal women, and the generation of intrinsic fibrinolytic activity

The diurnal fluctuations in plasma euglobulin fibrinolytic activity in women on oral contraceptives and in normal women showed similar patterns of increase. Following inactivation of inhibitors by flufenamate the individual increases and the evening levels did not differ. The diurnal increase was related to an increase in extrinsic (tissue-type) plasminogen activator (t-PA) activity, which contributes little to the total activity of the euglobulin fraction but induces an activation of the intrinsic system.     

Physical activity measurement instruments for children with cerebral palsy: a systematic review

Aim This paper is a systematic review of physical activity measurement instruments for field‐based studies involving children with cerebral palsy (CP). Method Database searches using PubMed Central, MEDLINE, CINAHL Plus, PsycINFO, EMBASE, Cochrane Library, and PEDro located 12 research papers, identifying seven instruments that met the inclusion criteria of (1) having been developed for children aged 0 to 18 years, (2) having been used to evaluate a physical activity dimension, and (3) having been used in a field‐based study involving children with CP. The instruments reviewed were the Activities Scale for Kids – Performance version (ASKp), the Canada Fitness Survey, the Children’s Assessment of Participation and Enjoyment/Preferences for Activities of Children (CAPE/PAC), the Compendium of Physical Activities, the Physical Activity Questionnaire – Adolescents (PAQ‐A), StepWatch, and the Uptimer. Second‐round searches yielded 11 more papers, providing reliability and validity evidence for the instruments. Results The instruments measure physical activity frequency, mode, domain, and duration. Although most instruments demonstrated adequate reliability and validity, only the ASKp and CAPE/PAC have established reliability and validity for children with physical disabilities; the Uptimer has established concurrent validity. No instrument measuring intensity in free‐living has been validated or found reliable for children with CP. Interpretation The findings suggest that further studies are needed to examine the methodological properties of physical activity measurement in children with CP. Combining subjective and objective instruments is recommended to achieve better understanding of physical activity participation.     

Estrogens and experimental ischemic stroke: a systematic review.

Estrogens are believed to provide females with endogenous protection against cerebrovascular events although clinical trials studying long-term hormone replacement have yielded disappointing results. In contrast, estrogens might be neuroprotective after experimental ischemia. We performed a systematic review of controlled experimental studies that administered estrogens before, or after, cerebral ischemia and measured lesion volume. Relevant studies were found from searching PubMed, Embase and Web of Science. From 161 identified publications, 27 studies using 1,304 experimental subjects were analyzed using the Cochrane Review Manager software. Estrogens reduced lesion volume in a dose-dependent manner, after either transient (P<0.001) or permanent (P<0.001) ischemia and whether administered before or up to 4 h after ischemia onset; no studies assessed efficacy for later time periods. The effect size for estrogens decreased with increasing quality scores for studies of transient ischemia. Estrogens reduced lesion volume when administered to ovariectomized females and young adult males, but had no effect in intact females. Limited data were present for aged animals and the full dose-response relationship was not available in all experimental groups. On the basis of these data, estrogens are a candidate treatment for ischemic stroke, although further preclinical studies are also warranted.     

Intrasellar cysticercosis: a systematic review

The objective of this study was to review patients with intrasellar cysticercosis to outline the features of this form of neurocysticercosis. A MEDLINE and manual search of patients with intrasellar cysticercosis were done. Abstracted data included clinical manifestations, neuroimaging findings, therapy, and outcome. Twenty-three patients were reviewed. Ophthalmological disturbances, including diminution of visual acuity and visual field defects following a chiasmatic pattern, were recorded in 67 % of cases. Endocrine abnormalities were found in 56 % of patients (panhypopituitarism, hyperprolactinemia, diabetes insipidus, and isolated hypothyroidism). In addition, some patients complained of seizures or chronic headaches. Neuroimaging studies showed lesions confined to the sellar region in 47 % of cases. The remaining patients also had subarachnoid cysts associated or not with hydrocephalus, parenchymal brain cysts, or parenchymal brain calcifications. Thirteen patients underwent surgical resection of the sellar cyst through a craniotomy in nine cases and by the transsphenoidal approach in four. Visual acuity or visual field defects improved in only two of these patients. Five patients were treated with cysticidal drugs without improvement. Intrasellar cysticercosis is rare and probably under-recognized. Clinical manifestations resemble those caused by pituitary tumors, cysts, or other granulomatous lesions. Neuroimaging findings are of more value when intrasellar cysts are associated with other forms of neurocysticercosis, such as basal subarachnoid cysts or hydrocephalus. Prompt surgical resection is mandatory to reduce the risk of permanent loss of visual function. There seems to be no role for cysticidal drug therapy in these cases.     

Metronidazole-induced encephalopathy: a systematic review

Journal of Neurology - Metronidazole, a commonly used antibiotic drug, can cause adverse effects in the central nervous system termed metronidazole-induced encephalopathy, leading to diagnostic...     

Epileptogenic drugs: a systematic review

A wide range of substances, including drugs and illicit compounds, increase the risk of epileptic seizures. In this systematic review, the authors address the issue of the epileptogenic potential of marketed drugs, with the aims of providing criteria for the assessment of the cause-effect relationship between drug exposure and the risk of seizures; and to identify the compounds better fulfilling the requirements of an epileptogenic drug. Finding a correlation between drug exposure and occurrence of seizures does not necessarily establish a causal association. In light of the available evidence, even with these limitations, some conclusive remarks can be made on the epileptogenic potential of some active principles. Drugs with high epileptogenic potential include meperidine, sevoflurane, clozapine, phenothiazines and cyclosporine. Drugs with intermediate epileptogenic potential include propofol, maprotiline, tricyclic antidepressants and chlorambucil. Drugs with low epileptogenic potential include fluorquinolones, carbapenems, bupropion and iodinated contrast media. Drugs with minimal or inconclusive epileptogenic potential include interferon alpha.     

Physical activity in people with epilepsy: A systematic review

This study aimed to systematically review studies focusing on levels of physical activity (PA) in people with epilepsy (PWE) compared with non-epilepsy controls, and identify factors associated with PA in PWE. Intervention studies were also reviewed to consider the effects of psychological interventions on levels of PA, and the effects of PA-based interventions on seizure activity, psychiatric comorbidity, and health-related quality of life (HRQoL). PRISMA guidelines were followed. Searches were conducted using PubMed, Cochrane Controlled Register of Trials, PsycINFO, and Embase. Forty-six studies met inclusion criteria, including case-control, cross-sectional, and intervention studies. Assessment measures included questionnaires, activity trackers, and measures of physiological fitness. Twelve of 22 (54.5%) case-control studies utilizing self-report questionnaire measures reported that PWE were performing lower levels of PA, less likely to be engaging in PA, or less likely to meet PA guidelines than controls. The remaining studies did not find a difference between PWE and controls. Eight of 12 (67%) case-control studies utilizing exercise/fitness tests reported that PWE performed significantly poorer than controls, whereas in two studies PWE performed better than controls. One of three studies investigating the relationship between PA and seizure frequency found that increased self-reported PA was associated with having fewer seizures, whereas two did not find a significant relationship. All seven cross-sectional studies that included measures of HRQoL and depression/anxiety found a positive relationship between levels of PA and HRQoL/reduced levels of depression and anxiety. All four studies that used PA-based interventions demonstrated improvements in levels of PA and increased HRQoL. Study quality was almost universally low. In conclusion, there is some evidence that PWE engage in less PA than peers, and that interventions can improve PA levels and HRQoL. However, there is a need for more robust study designs to better understand PA in individuals with epilepsy.     

Physical activity and fitness in children with developmental coordination disorder: a systematic review

Developmental coordination disorder (DCD) is a neurodevelopmental condition characterized by poor motor proficiency that interferes with a child's activities of daily living. Activities that most young children engage in such as running, walking, and jumping are important for the proper development of fitness and overall health. However, children with DCD usually find these activities challenging. A systematic review of the literature was conducted to synthesize the recent available data on fitness and physical activity in children with DCD, and to understand the extent of the differences between children with DCD and their typically developing peers. Systematic searches of electronic databases and reference lists identified 40 peer-reviewed studies meeting the inclusion criteria. These studies were reviewed in terms of: (a) study design, (b) population, (c) assessment tools, (d) measures, and (e) fitness and physical activity outcomes. It has been demonstrated that body composition, cardiorespiratory fitness, muscle strength and endurance, anaerobic capacity, power, and physical activity have all been negatively associated, to various degrees, with poor motor proficiency. However, differences in flexibility were not conclusive as the results on this parameter are mixed. Studies’ limitations and the impact of results on future work are discussed.