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CNS Drugs Nov 2019Prolonged-release (PR) fampridine is a potassium channel blocker used as a symptomatic treatment for walking disability in patients with multiple sclerosis (MS). Its... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Prolonged-release (PR) fampridine is a potassium channel blocker used as a symptomatic treatment for walking disability in patients with multiple sclerosis (MS). Its clinical effects in such patients have not been systematically reviewed, and may be more wide-ranging than expected.
OBJECTIVES
To summarize the evidence on the effects of PR fampridine in patients with MS.
METHODS
A systematic search of Pubmed, Scopus (including EMBASE), and PsycINFO (completed in 01/2019) was carried out to identify randomized controlled trials (RCT) that compared PR fampridine to placebo. When appropriate, data were pooled using a random-effects model, and standardized mean differences (SMD) were computed. Study quality was assessed using the Downs and Black checklist. PRISMA guidelines were followed. All retrieved functional outcomes were categorized according to the International Classification of Functioning, Disability and Health (ICF).
RESULTS
A total of 706 articles were screened for inclusion. Twenty RCTs involving 2616 patients met the eligibility criteria. Most studies were of good-to-excellent quality. PR fampridine administration resulted in significant benefits in relation to walking short distances (SMD: 1.23 (95% IC 0.65-1.81)) and perceived walking capacity (0.64 (0.27-1.02)). Its effects on muscle strength and middle-distance walking were not significant (0.53 (- 0.04 to 1.10) and 0.31 (- 0.18 to 0.80), respectively). No effect on higher-level cognitive functions (- 0.07 (- 0.58 to 0.45)) or hand and arm use (0.16 (- 0.33 to 0.64)) was observed. Individual studies reported effects on other outcomes across the ICF domains.
CONCLUSIONS
There is strong evidence that PR fampridine exerts strong effects on the ability to walk short distances and on perceived walking capacity. Other effects of PR fampridine according to the ICF are possible but still unclear.
Topics: 4-Aminopyridine; Delayed-Action Preparations; Double-Blind Method; Humans; Multiple Sclerosis; Potassium Channel Blockers; Randomized Controlled Trials as Topic; Treatment Outcome; Walking
PubMed: 31612418
DOI: 10.1007/s40263-019-00671-x -
Evidence Report/technology Assessment Nov 2010The purpose of this report is to systematically examine the possible causal mechanism(s) that may explain the association between alcohol (ethanol) consumption and the... (Review)
Review
OBJECTIVES
The purpose of this report is to systematically examine the possible causal mechanism(s) that may explain the association between alcohol (ethanol) consumption and the risk of developing breast and colorectal cancers.
DATA SOURCES
We searched 11 external databases, including PubMed® and Embase, for studies on possible mechanisms. These searches used Medical Subject Headings and free text words to identify relevant evidence.
REVIEW METHODS
Two reviewers independently screened search results, selected studies to be included, and reviewed each trial for inclusion. We manually examined the bibliographies of included studies, scanned the content of new issues of selected journals, and reviewed relevant gray literature for potential additional articles.
RESULTS
Breast Cancer. Five human and 15 animal studies identified in our searches point to a connection between alcohol intake and changes in important metabolic pathways that when altered may increase the risk of developing breast cancer. Alterations in blood hormone levels, especially elevated estrogen-related hormones, have been reported in humans. Several cell line studies suggest that the estrogen receptor pathways may be altered by ethanol. Increased estrogen levels may increase the risk of breast cancer through increases in cell proliferation and alterations in estrogen receptors. Human studies have also suggested a connection with prolactin and with biomarkers of oxidative stress. Of 15 animal studies, six reported increased mammary tumorigenesis (four administered a co-carcinogen and two did not). Other animal studies reported conversion of ethanol to acetaldehyde in mammary tissue as having a significant effect on the progression of tumor development. Fifteen cell line studies suggested the following mechanisms: Increased hormonal receptor levels. Increased cell proliferation. A direct stimulatory effect. DNA adduct formation. Increase cyclic adenosine monophosphate (camp). Change in potassium channels. Modulation of gene expression. Colorectal Cancer. One human tissue study, 19 animal studies (of which 12 administered a co-carcinogen and seven did not), and 10 cell line studies indicate that ethanol and acetaldehyde may alter metabolic pathways and cell structures that increase the risk of developing colon cancer. Exposure of human colonic biopsies to acetaldehyde suggests that acetaldehyde disrupts epithelial tight junctions. Among 19 animal studies the mechanisms considered included: Mucosal damage after ethanol consumption. Increased degradation of folate. Stimulation of rectal carcinogenesis. Increased cell proliferation. Increased effect of carcinogens. Ten cell line studies suggested: Folate uptake modulation. Tumor necrosis factor modulation. Inflammation and cell death. DNA adduct formation. Cell differentiation. Modulation of gene expression. One study used a combination of animal and cell line and suggested intestinal cell proliferation and disruption of cellular signals as possible mechanisms.
CONCLUSIONS
Based on our systematic review of the literature, many potential mechanisms by which alcohol may influence the development of breast or colorectal cancers have been explored but the exact connection or connections remain unclear. The evidence points in several directions but the importance of any one mechanism is not apparent at this time.
Topics: Alcohol Drinking; Animals; Breast Neoplasms; Cell Proliferation; Colorectal Neoplasms; Estrogens; Ethanol; Female; Humans; Male; Mammary Neoplasms, Animal; Oxidative Stress; Prolactin; Receptors, Estrogen; Risk
PubMed: 23126574
DOI: No ID Found -
Diabetes, Obesity & Metabolism Feb 2012Insulin secretagogues promote insulin release by binding to sulfonylurea receptors on pancreatic β-cells (SUR1). However, these drugs also bind to receptor isoforms on... (Review)
Review
AIM
Insulin secretagogues promote insulin release by binding to sulfonylurea receptors on pancreatic β-cells (SUR1). However, these drugs also bind to receptor isoforms on cardiac myocytes (SUR2A) and vascular smooth muscle (SUR2B). Binding to SUR2A/SUR2B may inhibit ischaemic preconditioning, an endogenous protective mechanism enabling cardiac tissue to survive periods of ischaemia. This study was designed to identify insulin secretagogues that selectively bind to SUR1 when given at therapeutic doses.
METHODS
Using accepted systematic review methods, three electronic databases were searched from inception to 13 June 2011. Original studies measuring the half-maximal inhibitory concentration (IC(50)) for an insulin secretagogue on K(ATP) channels using standard electrophysiological techniques were included. Steady-state concentrations (C(SS)) were estimated from the usual oral dose and clearance values for each drug.
RESULTS
Data were extracted from 27 studies meeting all inclusion criteria. IC(50) values for SUR1 were below those for SUR2A/SUR2B for all insulin secretagogues and addition of C(SS) values identified three distinct patterns. The C(SS) for gliclazide, glipizide, mitiglinide and nateglinide lie between IC(50) values for SUR1 and SUR2A/SUR2B, suggesting that these drugs bind selectively to pancreatic receptors. The C(SS) for glimepiride and glyburide (glibenclamide) was above IC(50) values for all three isoforms, suggesting these drugs are non-selective. Tolbutamide and repaglinide may have partial pancreatic receptor selectivity because IC(50) values for SUR1 and SUR2A/SUR2B overlapped somewhat, with the C(SS) in the midst of these values.
CONCLUSIONS
Insulin secretagogues display different tissue selectivity characteristics at therapeutic doses. This may translate into different levels of cardiovascular risk.
Topics: ATP-Binding Cassette Transporters; Animals; Carbamates; Cardiovascular Diseases; Cricetinae; Cyclohexanes; Diabetes Mellitus, Type 2; Gliclazide; Glipizide; Glyburide; Humans; Hypoglycemic Agents; Ischemic Preconditioning, Myocardial; Isoindoles; Mice; Muscle, Smooth, Vascular; Myocytes, Cardiac; Nateglinide; Phenylalanine; Piperidines; Potassium Channels, Inwardly Rectifying; Rats; Receptors, Drug; Risk Factors; Sulfonylurea Compounds; Sulfonylurea Receptors; Tolbutamide
PubMed: 21923736
DOI: 10.1111/j.1463-1326.2011.01496.x -
Journal of Diabetes Research 2021Diabetes mellitus (DM) is a major chronic metabolic disease in the world, and the prevalence has been increasing rapidly in recent years. The channel of K plays an...
OBJECTIVES
Diabetes mellitus (DM) is a major chronic metabolic disease in the world, and the prevalence has been increasing rapidly in recent years. The channel of K plays an important role in the regulation of insulin secretion. The variants in gene encoding the SUR1 subunit of K could cause a variety of phenotypes, including neonatal diabetes mellitus (NDM) and -induced nonneonatal diabetes mellitus (-NNDM). Since the features of -NNDM have not been elucidated, this study is aimed at concluding the genetic features and clinical characteristics.
METHODS
We comprehensively reviewed the literature associated with -NNDM in the following databases: MEDLINE, PubMed, and Web of Science to investigate the features of -NNDM.
RESULTS
Based on a comprehensive literature search, we found that 87 probands with -NNDM carried 71 genetic variant alleles, 24% of whom carried inactivating variants, 24% carried activating variants, and the remaining 52% carried activating or inactivating variants. Nine of these variants were confirmed to be activating or inactivating through functional studies, while four variants (p.R370S, p.E1506K, p.R1418H, and p.R1420H) were confirmed to be inactivating. The phenotypes of -NNDM were variable and could also present with early hyperinsulinemia followed by reduced insulin secretion, progressing to diabetes later. They had a relatively high risk of microvascular complications and low prevalence of nervous disease, which is different from NDM.
CONCLUSIONS
Genetic testing is essential for proper diagnosis and appropriate treatment for patients with -NNDM. And further studies are required to determine the complex mechanism of the variants of -NNDM.
Topics: Animals; Blood Glucose; Diabetes Mellitus; Genetic Predisposition to Disease; Genetic Variation; Humans; Insulin; Phenotype; Sulfonylurea Receptors
PubMed: 34631896
DOI: 10.1155/2021/9479268 -
Journal of the American Heart... Jan 2020Background Sudden unexpected death in epilepsy (SUDEP) is the leading cause of epilepsy-related death. SUDEP shares many features with sudden cardiac death and sudden...
Background Sudden unexpected death in epilepsy (SUDEP) is the leading cause of epilepsy-related death. SUDEP shares many features with sudden cardiac death and sudden unexplained death in the young and may have a similar genetic contribution. We aim to systematically review the literature on the genetics of SUDEP. Methods and Results PubMed, MEDLINE Epub Ahead of Print, Ovid Medline In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, and Scopus were searched through April 4, 2017. English language human studies analyzing SUDEP for known sudden death, ion channel and arrhythmia-related pathogenic variants, novel variant discovery, and copy number variant analyses were included. Aggregate descriptive statistics were generated; data were insufficient for meta-analysis. A total of 8 studies with 161 unique individuals were included; mean was age 29.0 (±SD 14.2) years; 61% males; ECG data were reported in 7.5% of cases; 50.7% were found prone and 58% of deaths were nocturnal. Cause included all types of epilepsy. Antemortem diagnosis of Dravet syndrome and autism (with duplication of chromosome 15) was associated with 11% and 9% of cases. The most frequently detected known pathogenic variants at postmortem were in Na and K ion channel subunits, as were novel potentially pathogenic variants (11%). Overall, the majority of variants were of unknown significance. Analysis of copy number variant was insignificant. Conclusions SUDEP case adjudication and evaluation remains limited largely because of crucial missing data such as ECGs. The most frequent pathogenic/likely pathogenic variants identified by molecular autopsy are in ion channel or arrhythmia-related genes, with an ≈11% discovery rate. Comprehensive postmortem examination should include examination of the heart and brain by specialized pathologists and blood storage.
Topics: Adolescent; Adult; Arrhythmias, Cardiac; Child; Child, Preschool; Death, Sudden, Cardiac; Epilepsy; Female; Genetic Predisposition to Disease; Genetic Variation; Humans; Infant; Male; Middle Aged; Phenotype; Potassium Channels; Risk Assessment; Risk Factors; Sodium Channels; Sudden Unexpected Death in Epilepsy; Young Adult
PubMed: 31865891
DOI: 10.1161/JAHA.119.012264 -
The Journal of Neuropsychiatry and... 2013Limbic encephalitis is an autoimmune neuropsychiatric condition characterized by subacute cognitive symptoms, seizures, and affective changes. Although limbic... (Review)
Review
Limbic encephalitis is an autoimmune neuropsychiatric condition characterized by subacute cognitive symptoms, seizures, and affective changes. Although limbic encephalitis is usually caused by an immune reaction secondary to neoplasms, different types of potentially treatable non-paraneoplastic limbic encephalitis (nPLE) have recently been described. In particular, published studies have reported variable responses to immunosuppressive therapy in Voltage-Gated Potassium Channel (VGKC) complex antibody-associated nPLE. This systematic literature review found that the most significant improvements were reported by patients presenting with affective symptoms and consistent neuroradiological changes. In these patients, improved clinical outcomes correlated with the largest decreases in antibody titers.
Topics: Autoantibodies; Autoimmune Diseases; Humans; Immunoglobulins, Intravenous; Limbic Encephalitis; Neuropsychological Tests; Plasma Exchange; Potassium Channels, Voltage-Gated; Steroids
PubMed: 24247853
DOI: 10.1176/appi.neuropsych.13020022 -
Epilepsia Mar 2024KCTD7-related progressive myoclonic epilepsy (PME) is a rare autosomal-recessive disorder. This study aimed to describe the clinical details and genetic variants in a...
OBJECTIVE
KCTD7-related progressive myoclonic epilepsy (PME) is a rare autosomal-recessive disorder. This study aimed to describe the clinical details and genetic variants in a large international cohort.
METHODS
Families with molecularly confirmed diagnoses of KCTD7-related PME were identified through international collaboration. Furthermore, a systematic review was done to identify previously reported cases. Salient demographic, epilepsy, treatment, genetic testing, electroencephalographic (EEG), and imaging-related variables were collected and summarized.
RESULTS
Forty-two patients (36 families) were included. The median age at first seizure was 14 months (interquartile range = 11.75-22.5). Myoclonic seizures were frequently the first seizure type noted (n = 18, 43.9%). EEG and brain magnetic resonance imaging findings were variable. Many patients exhibited delayed development with subsequent progressive regression (n = 16, 38.1%). Twenty-one cases with genetic testing available (55%) had previously reported variants in KCTD7, and 17 cases (45%) had novel variants in KCTD7 gene. Six patients died in the cohort (age range = 1.5-21 years). The systematic review identified 23 eligible studies and further identified 59 previously reported cases of KCTD7-related disorders from the literature. The phenotype for the majority of the reported cases was consistent with a PME (n = 52, 88%). Other reported phenotypes in the literature included opsoclonus myoclonus ataxia syndrome (n = 2), myoclonus dystonia (n = 2), and neuronal ceroid lipofuscinosis (n = 3). Eight published cases died over time (14%, age range = 3-18 years).
SIGNIFICANCE
This study cohort and systematic review consolidated the phenotypic spectrum and natural history of KCTD7-related disorders. Early onset drug-resistant epilepsy, relentless neuroregression, and severe neurological sequalae were common. Better understanding of the natural history may help future clinical trials.
Topics: Adolescent; Child; Child, Preschool; Humans; Infant; Young Adult; Electroencephalography; Epilepsies, Myoclonic; Myoclonic Epilepsies, Progressive; Potassium Channels; Seizures; Unverricht-Lundborg Syndrome
PubMed: 38231304
DOI: 10.1111/epi.17880 -
The Cochrane Database of Systematic... Jan 2010Potassium-sparing diuretics, which block the epithelial sodium channel (ENaC), are widely prescribed for hypertension as a second-line drug in patients taking other... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Potassium-sparing diuretics, which block the epithelial sodium channel (ENaC), are widely prescribed for hypertension as a second-line drug in patients taking other diuretics (e.g. thiazide diuretics) and much less commonly prescribed as monotherapy. Therefore, it is essential to determine the effects of ENaC blockers on blood pressure (BP), heart rate and withdrawals due to adverse effects (WDAEs) when given as a first-line or second-line therapy.
OBJECTIVES
To quantify the dose-related reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP) of ENaC blocker therapy as a first-line or second-line drug in patients with primary hypertension.
SEARCH STRATEGY
We searched CENTRAL (The Cochrane Library 2009, Issue 3), MEDLINE (1950 to August 2009), EMBASE (1980 to August 2009) and reference lists of articles.
SELECTION CRITERIA
Double-blind, randomized, controlled trials in patients with primary hypertension that evaluate, for a duration of 3 to 12 weeks, the BP lowering efficacy of: 1) fixed-dose monotherapy with an ENaC blocker compared with placebo; or 2) an ENaC blocker in combination with another class of anti-hypertensive drugs compared with the respective monotherapy (without an ENaC blocker).
DATA COLLECTION AND ANALYSIS
Two authors independently assessed the risk of bias and extracted data. Study authors were contacted for additional information. WDAE information was also collected from the trials.
MAIN RESULTS
No trials evaluating the BP lowering efficacy of ENaC blockers as monotherapy in patients with primary hypertension were identified. Only 6 trials evaluated the BP lowering efficacy of low doses of amiloride and triamterene as a second drug in 496 participants with a baseline BP of 151/102 mm Hg. The additional BP reduction caused by the ENaC blocker as a second drug was estimated by comparing the difference in BP reduction between the combination and monotherapy groups. The addition of low doses of amiloride and triamterene in these trials did not reduce BP. An estimate of the dose-related BP lowering efficacy for ENaC blockers was not possible because of a lack of trial data at higher doses.
AUTHORS' CONCLUSIONS
ENaC blockers do not have a statistically or clinically significant BP lowering effect at low doses but trials at higher doses are not available. The review did not provide a good estimate of the incidence of harms associated with ENaC blockers.
Topics: Amiloride; Antihypertensive Agents; Blood Pressure; Diuretics; Dose-Response Relationship, Drug; Drug Therapy, Combination; Humans; Hypertension; Randomized Controlled Trials as Topic; Sodium Channel Blockers; Triamterene
PubMed: 20091662
DOI: 10.1002/14651858.CD008167.pub2 -
Thrombosis Research Nov 2017Levosimendan has been developed for treatment of severe heart failure. The favorable hemodynamic effect of levosimendan is related to its unique dual mechanism of action... (Review)
Review
Levosimendan has been developed for treatment of severe heart failure. The favorable hemodynamic effect of levosimendan is related to its unique dual mechanism of action - increase of the contractile force of the myocardium caused by enhanced sensitivity of myofilaments to calcium combined with vasodilatation caused by the opening of adenosine triphosphate - dependent potassium channels. Due to the structural similarities to phosphodiesterase inhibitors it may partly exert its action via inhibition of phosphodiesterase inhibitors III. Inhibition of the phosphodiesterase inhibitors III leads to an increase of intracellular concentration of cyclic adenosine monophosphate causing an anti-aggregatory effect. There are some contradictory or indirect and inconclusive reports related to the impact of levosimendan on platelet function. The aim of this systematic review was to critically discuss the impact of levosimendan on platelet function according to currently available knowledge based on the findings of experimental as well as observational and randomized clinical studies.
Topics: Blood Platelets; Humans; Hydrazones; Platelet Function Tests; Pyridazines; Simendan; Vasodilator Agents
PubMed: 28987709
DOI: 10.1016/j.thromres.2017.10.001 -
Journal of Cardiothoracic Surgery Nov 2010Atrial Fibrillation (AF) is the most common arrhythmia occurring after cardiac surgery. Its incidence varies depending on type of surgery. Postoperative AF may cause... (Review)
Review
Atrial Fibrillation (AF) is the most common arrhythmia occurring after cardiac surgery. Its incidence varies depending on type of surgery. Postoperative AF may cause hemodynamic deterioration, predispose to stroke and increase mortality. Effective treatment for prophylaxis of postoperative AF is vital as reduces hospitalization and overall morbidity. Beta-blockers, have been proved to prevent effectively atrial fibrillation following cardiac surgery and should be routinely used if there are no contraindications. Sotalol may be more effective than standard b-blockers for the prevention of AF without causing an excess of side effects. Amiodarone is useful when beta-blocker therapy is not possible or as additional prophylaxis in high risk patients. Other agents such as magnesium, calcium channels blocker or non-antiarrhythmic drugs as glycose-insulin--potassium, non-steroidal anti-inflammatory drugs, corticosteroids, N-acetylcysteine and statins have been studied as alternative treatment for postoperative AF prophylaxis.
Topics: Anti-Arrhythmia Agents; Atrial Fibrillation; Cardiac Surgical Procedures; Chemoprevention; Humans; Premedication
PubMed: 21118555
DOI: 10.1186/1749-8090-5-121