The BH4 domain of Bcl-X(L) rescues astrocyte degeneration in amyotrophic lateral sclerosis by modulating intracellular calcium signals.

Collective evidence indicates that motor neuron degeneration in amyotrophic lateral sclerosis (ALS) is non-cell-autonomous and requires the interaction with the neighboring astrocytes. Recently, we reported that a subpopulation of spinal cord astrocytes degenerates in the microenvironment of motor neurons in the hSOD1(G93A) mouse model of ALS. Mechanistic studies in vitro identified a role for the excitatory amino acid glutamate in the gliodegenerative process via the activation of its inositol 1,4,5-triphosphate (IP(3))-generating metabotropic receptor 5 (mGluR5). Since non-physiological formation of IP(3) can prompt IP(3) receptor (IP(3)R)-mediated Ca(2+) release from the intracellular stores and trigger various forms of cell death, here we investigated the intracellular Ca(2+) signaling that occurs downstream of mGluR5 in hSOD1(G93A)-expressing astrocytes. Contrary to wild-type cells, stimulation of mGluR5 causes aberrant and persistent elevations of intracellular Ca(2+) concentrations ([Ca(2+)](i)) in the absence of spontaneous oscillations. The interaction of IP(3)Rs with the anti-apoptotic protein Bcl-X(L) was previously described to prevent cell death by modulating intracellular Ca(2+) signals. In mutant SOD1-expressing astrocytes, we found that the sole BH4 domain of Bcl-X(L), fused to the protein transduction domain of the HIV-1 TAT protein (TAT-BH4), is sufficient to restore sustained Ca(2+) oscillations and cell death resistance. Furthermore, chronic treatment of hSOD1(G93A) mice with the TAT-BH4 peptide reduces focal degeneration of astrocytes, slightly delays the onset of the disease and improves both motor performance and animal lifespan. Our results point at TAT-BH4 as a novel glioprotective agent with a therapeutic potential for ALS.

Changes in Aortic Pulse Wave Velocity in Hypertensive Postmenopausal Women: Comparison Between a Calcium Channel Blocker vs Angiotensin Receptor Blocker Regimen.

J Clin Hypertens (Greenwich). 2012;14:773-778. ©2012 Wiley Periodicals, Inc. Postmenopausal women are at greater risk for hypertension-related cardiovascular disease. Antihypertensive therapy may help alleviate arterial stiffness that represents a potential modifiable risk factor of hypertension. This randomized controlled study investigated the difference between an angiotensin receptor blocker and a calcium channel blocker in reducing arterial stiffness. Overall, 125 postmenopausal hypertensive women (age, 61.4±6 years; systolic blood pressure/diastolic blood pressure [SBP/DBP], 158±11/92±9 mm Hg) were randomized to valsartan 320 mg±hydrochlorothiazide (HCTZ) (n=63) or amlodipine 10 mg±HCTZ (n=62). The primary outcome was carotid-to-femoral pulse wave velocity (PWV) changes after 38 weeks of treatment. Both treatments lowered peripheral blood pressure (BP) (-22.9/-10.9 mm Hg for valsartan and -25.2/-11.7 mm Hg for amlodipine, P=not significant) and central BP (-15.7/-7.6 mm Hg for valsartan and -19.2/-10.3 mm Hg for amlodipine, P<.05 for central DBP). Both treatments similarly reduced the carotid-femoral PWV (-1.9 vs -1.7 m/s; P=not significant). Amlodipine was associated with a higher incidence of peripheral edema compared with the valsartan group (77% vs 14%, P<.001). BP lowering in postmenopausal women led to a reduction in arterial stiffness as assessed by PWV measurement. Both regimens reduced PWV to a similar degree after 38 weeks of treatment despite differences in central BP lowering, suggesting that the effect of valsartan on PWV is mediated through nonhemodynamic effects.

Les calcifications pulmonaires métastatiques [Pulmonary metastatic calcification].

INTRODUCTION: The lung is the organ most frequently involved by metastatic calcification. This condition is probably under-diagnosed, the patients usually being asymptomatic. This article summarizes the current knowledge concerning pulmonary metastatic calcification. BACKGROUND: The pathogenesis of pulmonary metastatic calcification is not well known, but it involves phosphate-calcium balance, renal function and pH. The most frequently encountered aetiologies are hyperparathyroidism, neoplastic bony lesions, and renal failure. The definitive diagnosis is achieved by histology, radiological examinations being insensitive. The clinical manifestations are various and can include a pulmonary restrictive syndrome, diffusion abnormalities, hypoxaemia and respiratory failure. The latter can be severe and influence the prognosis adversely: 19 cases of fatal pulmonary metastatic calcification have been reported. The treatment is aetiological and symptomatic. VIEWPOINT: The prognostic factors for a poor outcome of this potentially lethal condition remain to be determined. The management of asymptomatic patients is also uncertain. CONCLUSIONS: Pulmonary metastatic calcification is a rare condition of complex pathogenesis. The clinical manifestations are varied, ranging from asymptomatic to severe, even fatal.

Production and Evaluation of Calcium Magnesium Acetate, HR-243, 1982

Calcium magnesium acetate (CMA) has been identified by Bjorksten Research Laboratories as an environmentally harmless alternative to sodium or calcium chloride for deicing highways. Their study found CMA to be noncorrosive to steel, aluminum and zinc with little or no anticipated environmental impact. When used, it degrades into elements found in abundance in nature. The deicing capabilities were found to be similar to sodium chloride. The neutralized CMA they produced did cause scaling of PC concrete, but they did not expect mildly alkaline CMA to have this effect. In the initial investigation of CMA at the Iowa DOT laboratory, it was found that CMA produced from hydrated lime and acetic acid was a light, fluffy material. It was recognized that a deicer in this form would be difficult to effectively distribute on highways without considerable wind loss. A process was developed to produce CMA in the presence of sand to increase particle weight. In this report the product of this process, which consists of sand particles coated with CMA, is referred to as "CMA deicer". The mixture of salts, calcium magnesium acetate, is referred to as "CMA". The major problems with CMA for deicing are: (1) it is not commercially available, (2) it is expensive with present production methods and (3) there is very little known about how it performs on highways under actual deicing conditions. In view of the potential benefits this material offers, it is highly desirable to find solutions or answers to these problems. This study provides information to advance that effort. The study consisted of four principal tasks which were: 1. Production of CMA Deicer The objective was to further develop the laboratory process for producing CMA deicer on a pilot plant basis and to produce a sufficient quantity for field trials. The original proposal called for producing 20 tons of CMA deicer. 2. Field Evaluation of CMA Deicer The objective was to evaluate the effectiveness of CMA deicer when used under field conditions and obtain information on application procedures. Performance was compared with a regular 50/50 mixture of sand and sodium chloride. 3. Investigation of Effects of CMA on PC Concrete The objective was to determine any scaling effect that mildly alkaline CMA might have on PC concrete. Comparison was made with calcium chloride. 4. Determine Feasibility of Producing High Magnesium CMA The objective was to investigate the possibility of producing a CMA deicer with magnesium acetate content well above that produced from dolomitic lime. A high magnesium acetate content is desirable because pure magnesium acetate has a water eutectic of -22 F° as compared with +5 F° for calcium acetate and is therefore a more effective deicer.

Aggregation of liposomes induced by calcium: A structural and kinetic study

In this work, the calcium-induced aggregation of phosphatidylserine liposomes is probed by means of the analysis of the kinetics of such process as well as the aggregate morphology. This novel characterization of liposome aggregation involves the use of static and dynamic light-scattering techniques to obtain kinetic exponents and fractal dimensions. For salt concentrations larger than 5 mM, a diffusion-limited aggregation regime is observed and the Brownian kernel properly describes the time evolution of the diffusion coefficient. For slow kinetics, a slightly modified multiple contact kernel is required. In any case, a time evolution model based on the numerical resolution of Smoluchowski's equation is proposed in order to establish a theoretical description for the aggregating system. Such a model provides an alternative procedure to determine the dimerization constant, which might supply valuable information about interaction mechanisms between phospholipid vesicles.

Ammonium Phosphate/Fly Ash Road Base Construction, HR-294, 1993

The objective of this research project was to evaluate the construction and service performance of ammonium phosphate/fly ash (APFA) treated base courses of crushed fines and/or unprocessed sand. Specific test results related to construction of the test sections were included in the 1987 construction report by Iowa State University. The performance of the experimental sections is dealt with in this final report. This 1986 project demonstrated that in all cases the control sections utilizing a Type B base experienced dramatically less cracking in the surface than the APFA treated base sections. The cost per mix and subsequent surface maintenance costs for the APFA base sections, especially those having a substantial amount of limestone, were higher than the Type B base control sections. This type of construction may prove to be economical only when petroleum product costs escalate.

Calcium entry blockade attenuates the acute blood pressure rise induced by cigarette smoking.

The purpose of this study was to assess whether the administration of a calcium entry blocker can prevent the acute blood pressure rise induced by cigarette smoking. Seven male habitual smokers were included. After 45 min of equilibration, they took in randomized single-blind fashion at a 1 week interval either a placebo or nifedipine, 10 mg p.o. Thirty minutes thereafter, the subjects smoked within 10 min two cigarettes containing 1.4 mg of nicotine each. In addition to heart rate and skin blood flow (laser Doppler method), blood pressure of the median left finger was monitored continuously for 100 min using a noninvasive device (Finapres). Nifedipine induced an increase in skin blood flow that was not influenced by smoking. This skin blood flow response was observed although nifedipine had by itself no effect on systemic blood pressure. The calcium antagonist markedly attenuated the blood pressure rise induced by cigarette smoking. However, it tended to accentuate the heart rate acceleration resulting from inhalation of nicotine-containing smoke.

Members of the PHO1 gene family show limited functional redundancy in phosphate transfer to the shoot, and are regulated by phosphate deficiency via distinct pathways.

The PHO1 family comprises 11 members in Arabidopsis thaliana. In order to decipher the role of these genes in inorganic phosphate (Pi) transport and homeostasis, complementation of the pho1 mutant, deficient in loading Pi to the root xylem, was determined by the expression of the PHO1 homologous genes under the control of the PHO1 promoter. Only PHO1 and the homologue PHO1;H1 could complement pho1. The PHO1;H1 promoter was active in the vascular cylinder of roots and shoots. Expression of PHO1;H1 was very low in Pi-sufficient plants, but was strongly induced under Pi-deficient conditions. T-DNA knock-out mutants of PHO1;H1 neither showed growth defects nor alteration in Pi transport dynamics, or Pi content, compared with wild type. However, the double mutant pho1/pho1;h1 showed a strong reduction in growth and in the capacity to transfer Pi from the root to the shoot compared with pho1. Grafting experiments revealed that phenotypes associated with the pho1 and pho1/pho1;h1 mutants were linked to the lack of gene expression in the root. The increased expression of PHO1;H1 under Pi deficiency was largely controlled by the transcription factor PHR1 and was suppressed by the phosphate analogue phosphite, whereas the increase of PHO1 expression was independent of PHR1 and was not influenced by phosphite. Together, these data reveal that although transfer of Pi to the root xylem vessel is primarily mediated by PHO1, the homologue PHO1;H1 also contributes to Pi loading to the xylem, and that the two corresponding genes are regulated by Pi deficiency by distinct signal transduction pathways.

Microtubule-associated protein 1B binds glyceraldehyde-3-phosphate dehydrogenase.

Microtubule-associated protein 1B, MAP1B, is a major cytoskeletal protein during brain development and one of the largest brain MAPs associated with microtubules and microfilaments. Here, we identified several proteins that bind to MAP1B via immunoprecipitation with a MAP1B-specific antibody, by one and two-dimensional gel electrophoresis and subsequent mass spectrometry identification of precipitated proteins. In addition to tubulin and actin, a variety of proteins were identified. Among these proteins were glyceraldehyde-3-phosphate dehydrogenase (GAPDH), heat shock protein 8, dihydropyrimidinase related proteins 2 and 3, protein-L-isoaspartate O-methyltransferase, beta-spectrin, and clathrin protein MKIAA0034, linking either directly or indirectly to MAP1B. In particular, GAPDH, a key glycolytic enzyme, was bound in large quantity to the heavy chain of MAP1B in adult brain tissue. In vitro binding studies confirmed a direct binding of GAPDH to MAP1B. In PC12 cells, GAPDH was found in cytoplasm and nuclei and partially co-localized with MAP1B. It disappeared from the cytoplasm under oxidative stress or after a disruption of cytoskeletal elements after colcemid or cytochalasin exposure. GAPDH may be essential in the local energy provision of cytoskeletal structures and MAP1B may help to keep this key enzyme close to the cytoskeleton.

Experimental Use of Calcium Magnesium Acetate, HR-253, 1983

The Iowa Department of Transportation Materials Laboratory personnel announced in early 1982 a process to produce a road deicer consisting of sand grains coated with calcium magnesium acetate (CMA). From that point forward the Iowa DOT began searching for a means of economically producing CMA to their concept. During 1983 and 1984 the first attempts devised for commercially producing CMA were attempted by the W.G. Block Company, Davenport, Iowa, under Iowa Highway Research Board Project HR-253. This first attempt at commercially producing CMA was accomplished by the use of concrete transit mixer equipment. Even though this procedure proved successful in the batch mixing of CMA, the need for higher production rates to reduce the cost per ton still existed. During the fall of 1984, Cedarapids Inc, Cedar Rapids, Iowa, proposed to Iowa DOT personnel the application of their technology to a continuous mixing concept for CMA. Arrangements were made for the continuous test mixing of 60 to 100 tons of CMA/sand deicer. This report covers the production effort, description and results of procedures outlined in Cedarapids Inc's proposal of September 19, 1984. The objectives of this research were: 1. To produce the CMA/sand deicer concept on a continuous mixing basis to Iowa DOT CMA concentration levels. 2. To evaluate the results of preheating the carrying vehicle (sand) prior to CMA ingredient introduction. 3. To analyze the feasibility of production equipment and procedures necessary for portable and/or stationary applications of continuous mixing concepts.

Neuronal calcium channel mutation in a patient with congenital ataxia and attacks of hemiplegic migraine with cerebral edema

Background: Familial Hemiplegic Migraine (FHM), characterized by a prolonged unilateral hemiparesis, mainly results from mutations in the alpha-1a subunit of the calcium channel gene CACNA1A that can also cause two other dominantly inherited neurological disorders, Episodic Ataxia type 2 (EA2, with sometimes migrainous headaches) and Spinocerebellar Ataxia type 6 (SCA6, late-onset and progressive). A same mutation can have different clinical expression in a family (hemiplegic migraine, migraine-coma, cerebellar ataxia). CACNA1A mutations in FHM are usually missense, leading to gain-of-function, while truncating mutations leading to loss-of-function are usually associated with EA2. Case report: This 9-year-old girl was seen as a baby for hypotonia and transient vertical nystagmus. Her first brain MRI was normal. She evolved as a congenital ataxia, but since the age of two, she had attacks of coma, hemiparesis (either side), partial seizures, dystonic movements and fever. Attacks were initially triggered by minor head bumps, subsequently spontaneous. Brain MRIs in the acute stage always showed transient unilateral hemisphere swelling. Follow-up images revealed atrophic lesions in the temporo-occipital regions and cerebellar atrophy. A prophylactic trial with flunarizine was ineffective. Acetazolamide was recently introduced. Methods: Since our patient shared features of both FHM and EA2, we studied the CACNA1A gene by direct sequencing in the patient's and parents' DNA. Results: We identified an unreported de novo heterozygous deletion of three base pairs (c.4503_4505delCTT) predicting the deletion of one amino acid (p.Phe1502del). The CACNA1A protein contains 4 domains, each formed by six transmembrane segments. The deletion is located in a highly conserved region in segment 6 (S6) of the third domain. Mutations in S6 segments of calcium channels change single-channel conductance and channel selectivity, most resulting in loss-of-function. Outlook: In vitro expression studies of the identified mutation are underway, aiming at understanding its functional consequences and finding an efficient treatment.

Calcium Microdomains Control Exo-Endocytosis of Synaptic-Like Microvesicles in Astrocytes

During the last decade, the discovery that astrocytes possess a nonelectrical form of excitability (Ca21-excitability) that leads to the release of chemical transmitters, an activity called ''gliotransmission'', indicates that these cells may have additional important roles in brain function. Elucidating the stimulus-secretion coupling leading to the exocytic release of chemical transmitters (such as glutamate, Bezzi et al., Nature Neurosci, 2004) may therefore clarify i) whether astrocytes represent in full a new class of secretory cells in the brain and ii) whether they can participate to the fast brain signaling in the brain. Here by using a recently developed approach for studying vesicle recycling dynamics at synapses (Voglmaier et al., Neuron, 2006; Balaji and Ryan, PNAS, 2007) combined with epifluorescence and total internal reflection fluorescence (TIRF) imaging, we investigated the spatiotemporal characteristics of stimulus-secretion coupling leading glutamate exocytosis of synaptic-like microvesicles (SLMVs) in astrocytes. We performed the analysis at both the whole-cell and single-vesicle levels providing the first system for comparing exo-endocytic processes in astrocytes with those in neurons. Both the time course and modalities of secretion in astrocytes present more similarities to neurons then previously expected. We found that 1. the G-protein-coupled receptor (GPCR)-evoked exocytosis reached the maximum on a ms time scale and that 2. ER tubuli formed sub-micrometer domains beneath the plasma membrane in close proximity to exocytic vesicles, where fusion events were spatiotemporally correlated with fast Ca21 events.

Evaluation of Calcium Magnesium Acetate Deicer in Scott County, HR-253, Progress Report, 1987

The field testing of the noncorrosive alternative deicing agent, calcium magnesium acetate is described. Seventy three tons were produced of one part CMA and three parts sand deicer which was field tested on I-280 from I-80 to the Mississippi River (7,000 ADT with 50% trucks). A comparative application was made with one part sand and one part sodium chloride. The study found that CMA deicer required a longer time for the pavement to reach normal conditions, and 20-25% more CMA deicer to provide the desired deicing. It was concluded that the CMA deicer was not as dependable as the sodium chloride deicing agent, and it was more difficult to clean up the equipment for spreading the CMA deicer.

Experimental Use of Calcium Magnesium Acetate, Addendum, HR-253, 1984

The Iowa Department of Transportation Materials Laboratory personnel developed a process to produce a road deicer consisting of sand grains coated with calcium magnesium acetate (CMA). Research project HR-253 was established to explore commercial production of the CMA/sand deicer by an independent contractor. About 60 tons of the deicer was produced at a ready-mix concrete facility and evaluated in the field during the 1983-1984 winter season. The initial contracted production of CMA/sand deicer under research project HR-253 identified two major problems: (1) excessive unreacted lime in the final product, and (2) formation of spherical lumps within the product requiring subsequent size reduction. It was recommended in the HR-253 report that additional deicer be produced as a continuation of the project in order to address these problems and further develop the production process. A contract was negotiated with W. G. Block Co. to produce and deliver 50 tons of additional deicer. This addendum report covers this production effort including descriptions and results of all modifications of equipment and process procedures used.