Delayed Decline of Cognitive Function by Antihypertensive Agents: A Cohort Study Linked with Genotype Data.

BACKGROUND: Arterial hypertension is among factors with the potential for increasing the risk of cognitive impairment in elderly subjects. However, studies investigating the effects of antihypertensives on cognitive function have reported mixed results. METHODS: We have used the National Alzheimer's Coordinating Center (NACC) Uniform Data Set (UDS) to investigate the effect of each class of antihypertensives, both as single and combined, in reducing the rate of conversion from normal to mild cognitive impairment (MCI). RESULTS: The use of antihypertensive drugs was associated with 21% (Hazard ratio: 0.79, p<01001) delay in the rate of conversion to MCI. This effect was modulated by age, gender, and genotypic APOE4 allele. Among different antihypertensive subclasses, calcium channel blockers (CCBs) (24%, HR: 0.76, P=0.004), diuretics (21%, HR: 0.79, P=0.006), and α1-adrenergic blockers (α1-ABs) (23%, HR: 0.77, P=0.034) significantly delayed the rate of MCI conversion. A significant effect was observed with the selective L-type voltage-gated CCBs, dihydropyridines, amlodipine (47%, HR=0.53, P<0.001) and nifedipine (49%, HR=0.51, P=0.012), whereas non-DHPs showed insignificant effect. Loop diuretics, potassium sparing diuretics, and thiazides all significantly reduced the rate of MCI conversion. Combination of α1-AB and diuretics led to synergistic effects; combination of vasodilators plus ß-blockers (ßBs), and α1-AB plus ßBs led to additive effect in delaying the rate of MCI conversion, when compared to a single drug. CONCLUSION: Our results could have implications for the more effective treatment of hypertensive elderly adults who are likely to be at high risk of cognitive decline and dementia. The choice of combination of antihypertensive therapy should also consider the combination which would lead to an optimum benefit on cognitive function.

Neuroendocrine Responses to Transvascular Autonomic Modulation: A Modified Balloon Angioplasty in Multiple Sclerosis Patients.

Balloon angioplasty (BA) is a treatment modality to correct vascular lesions in multiple sclerosis (MS) patients, who present with chronic cerebrospinal venous insufficiency (CCSVI). We hypothesized that BA clinical benefits stems in part from improvement in cardiovascular autonomic nervous system (ANS) function. We adopted the Transvascular Autonomic Modulation (TVAM), as a modified BA technique, with the objective of further enhancing ANS functional activities. TVAM involved dilation of multiple vascular beds, including IJVs, azygos and renal veins, and application of manual compression. Since the ANS regulates the function of the hypothalamus pituitary (HPA) axis, we examined TVAM effects on HPA axis in MS patients, and determined the relationship between ANS function and HPA activity. The adrenocorticotropic hormone (ACTH) and cortisol serum levels, systolic and diastolic blood pressure (BP), and heart rate variability (HRV) parameters were measured before and 24 h after TVAM procedure in 72 MS patients. Baseline ACTH and cortisol serum levels were lower than normal ranges in 18% and 25% MS patients respectively. The intervention resulted in significant reductions in both ACTH and cortisol (p<0.001), with a more marked ACTH reduction in males compared to females (p<0.001). Post-TVAM BP increased in patients who presented with baseline BP within lower limits of normal ranges, but decreased in patients with baseline BP above the normal ranges. In a univariate analysis, the changes (Δ) in ACTH serum levels correlated weakly, although significantly, with Δ in diastolic BP (r=-0.265, p=0.03), and Δ in cortisol serum levels correlated weakly, but significantly, with Δ in systolic BP (r=-0.283, p=0.01). The observed ACTH and cortisol reductions are counter to the stress-mediated increases in serum levels of these hormones, which are expected following an invasive procedure. The clinical implications of this unexpected response warrant further investigations.

Acamprosate modulates experimental autoimmune encephalomyelitis.

OBJECTIVE: This pilot study aimed to determine the efficacy of acamprosate (N-acetyl homotaurine) in reducing the pathological features of experimental autoimmune encephalomyelitis (EAE) which is an animal model for multiple sclerosis (MS). BACKGROUND: The amino acid taurine has multiple biological activities including immunomodulation and neuromodulation. The synthetic acetylated taurine derivative, acamprosate, which crosses the blood-brain barrier more readily compared to taurine, is currently being used for the prevention of alcohol withdrawal symptoms associated with enhanced glutamatergic receptor function and GABA receptor hypofunction. METHODS: EAE was induced in C57BL/6 female mice with myelin oligodendrocyte glyocoprotein, amino acid 35-55. Mice were treated with 20, 100 and 500 mg/kg acamprosate for 21 days. RESULTS: Neurological scores at disease peak were reduced by 21, 64 and 9% in the 20, 100 and 500 mg/kg groups, respectively. Neurological improvement in the 100 mg/kg group correlated with a reduction in numbers of inflammatory lesions and the extent of CNS demyelination. Blood TNF-α levels were significantly reduced in the 500 mg/kg group. DISCUSSION: Acamprosate and other taurine analogs have a potential for future MS therapy.

Soluble receptor for advanced glycation end products in multiple sclerosis: a potential marker of disease severity.

OBJECTIVES: To compare serum levels of the receptor for advanced glycation end products (sRAGE) between multiple sclerosis (MS) patients and healthy control subjects, and to investigate whether serum sRAGE levels correlate with MS disease severity as indicated by the Kurtzke Expanded Disability Status Scale (EDSS). METHOD: 37 patients with clinical diagnosis of MS and 22 healthy control subjects were investigated in a cross-sectional study using enzyme-linked immunosorbent assays (ELISA). RESULTS: Serum levels of sRAGE were found to be significantly lower in MS patients compared to levels in healthy controls (p = 0.005). A trend toward lower levels of serum sRAGE was observed in female MS patients compared to their male counterparts (p = 0.05). A relationship between sRAGE and EDSS, and sRAGE and rate of clinical relapse was observed (p = 0.012). CONCLUSION: The significant reduction of sRAGE in MS patients relative to healthy controls supports the potential role for RAGE axis in MS clinical pathology. Lower levels of sRAGE may be associated with enhanced inflammatory responses. Based on these observations, further investigations into the role of sRAGE in MS clinical pathology is warranted.

A comparative study of permeabilization induced by extracellular ATP and by Sendai virus.

Both Sendai virus and extracellular ATP induce membrane changes in 3T6 cells which allow passage of phosphorylated metabolites and normally impermeant aqueous solutes. The two processes share many features in common, including their kinetics and the effects of temperature, Ca2+, and various metabolic inhibitors. Furthermore, in each case permeabilization is preceded by net changes in intracellular cations. However, there are significant differences in that only ATP-dependent permeabilization is influenced by changes in the ionic strength of the medium, by inhibition of the Na+, K+, Cl- cotransporter and by preincubation of 3T6 cells with dithiothreitol.