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1.
Chemosphere ; 350: 141030, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38154668

ABSTRACT

Corncob (CC) based solar evaporators were employed to desalinize seawater brought from the Vallarta coast in Mexico. The pure CC produced an evaporation-rate and evaporation-efficiency of 0.63 kg m-2 h-1 and 38.4%, respectively, under natural solar light. Later, the CC was coated with carbonized CC (CCCE evaporator) or was coated with graphene (CCGE evaporator). Those evaporators were used for the desalination of seawater and obtained higher evaporation rates of 1.59-1.67 kg m-2 h-1, and higher evaporation efficiencies of 92-94% (under natural solar light). The desalination experiments were repeated under artificial solar light and the evaporation-rates/evaporation-efficiencies slightly decreased to 1.43-1.52 kg m-2 h-1/88-92%. The surface analysis of the evaporators by FTIR, XPS and Raman revealed that the CCGE evaporator had on its surface a lower content of defects and a higher amount of OH groups than the CCCE evaporator. Therefore, the CCGE evaporator had higher evaporation-rates/evaporation-efficiencies in comparison with the CCCE evaporator. Furthermore, we purified water contaminated with three different herbicides (fomesafen, 2-6 dichlorobenzamide and 4-chlorophenol at 30 ppm) by evaporation and using natural solar light. Interestingly, the CCCE and CCGE evaporators also removed the herbicides by physical adsorption with efficiencies of 12-22.5%. Moreover, the CCGE evaporator removed vegetable oil from contaminated water by adsorption and its maximum adsorption capacity was 1.72 g/g. Overall, our results demonstrated that the corncob-based evaporators studied here are a low-cost alternative to obtain clean water under natural solar light and this one was more effective for the desalination of seawater than the artificial sunlight (Xe lamp).


Subject(s)
Herbicides , Zea mays , Seawater , Water , Sunlight
2.
J Environ Manage ; 345: 118784, 2023 Nov 01.
Article in English | MEDLINE | ID: mdl-37611517

ABSTRACT

Magnetic bismuth ferrite (BiFO) microparticles were employed for the first time for the removal of polystyrene (PS) nano/microplastics from the drinking water. BiFO is formed by porous agglomerates with sizes of 5-11 µm, while the PS nano/microparticles have sizes in the range of 70-11000 nm. X-ray diffraction studies demonstrated that the BiFO microparticles are composed of BiFeO3/Bi25FeO40 (the content of Bi25FeO40 is ≈ 8.6%). Drinking water was contaminated with PS nano/microparticles (1 g L-1) and BiFO microparticles were also added to the contaminated water. Later, the mixture of PS-particles + BiFO was irradiated with NIR light (980 nm). Consequently, PS nano/microparticles melted on the BiFO microparticles due to the excessive heating on their surface. At the same time, the NIR (near infrared) light generated oxidizing agents (∙OH and h+), which degraded the by-products formed during the photocatalytic degradation of PS nano/microparticles. Subsequently, the NIR irradiation was stopped, and a Neodymium magnet was utilized to separate the BiFO microparticles from the water. This last procedure also permitted the removal of PS nano/microparticles by physical adsorption. Zeta potential measurements demonstrated that the BiFO surface was positively charged, allowing the removal of the negatively charged PS nano/microparticles by electrostatic attraction. The combination of the photocatalytic process and the physical adsorption permitted a complete removal of PS nano/microparticles after only 90 min as well as a high mineralization of by-products (≈95.5% as confirmed by the total organic carbon measurements). We estimate that ≈23.6% of the PS nano/microparticles were eliminated by photocatalysis and the rest of PS particles (≈76.4%) by physical adsorption. An outstanding adsorption capacity of 195.5 mg g-1 was obtained after the magnetic separation of the BiFO microparticles from the water. Hence, the results of this research demonstrated that using photocatalysis + physical-adsorption is a feasible strategy to quickly remove microplastic contaminants from the water.


Subject(s)
Drinking Water , Water Pollutants, Chemical , Polystyrenes , Plastics , Bismuth , Microplastics , Adsorption , Magnetic Phenomena , Water Pollutants, Chemical/analysis
3.
Public Health ; 219: 154-156, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37201416

ABSTRACT

OBJECTIVES: We analyze the profile of adults who used a mask in the context of the COVID-19 pandemic in Latin America, between October and November 2020, right before the mass vaccination campaigns. STUDY DESIGN: Based on the Latinobarometer 2020 data, we assess the individual, regional, cultural and political factors of people who used a mask in the context of the COVID-19 pandemic in 18 countries of Latin America. METHODS: We applied a logistic regression to model the probability of using the mask regularly to avoid being infected with the COVID-19 virus. RESULTS: Women, older people, those with higher education, those being employed and not working in temporarily jobs, retirees, students, people with a centrist political ideology, and Catholics had a higher chance of using a face mask on a regular basis. People living in Venezuela, Chile, Costa Rica and Brazil were the most likely to use face masks. CONCLUSION: These results highlight the need to understand the social forces behind the willingness to adopt non-pharmacological preventive measures to make them more effective in health crisis emergencies.


Subject(s)
COVID-19 , Adult , Female , Humans , Aged , Latin America/epidemiology , COVID-19/epidemiology , COVID-19/prevention & control , Pandemics/prevention & control , Masks , Vaccination
4.
J Environ Manage ; 315: 115204, 2022 Aug 01.
Article in English | MEDLINE | ID: mdl-35523072

ABSTRACT

This investigation reports the photocatalytic performance of the tungsten doped titania (TiO2:W or TW) with and without coating of chlorophyll (Chl) for the removal of the RhB dye from the drinking water. These particles were also supported on recycled plastic bottle caps (Bcap) to form other photocatalytic composites (TW/Bcap and TW + Chl/Bcap). The SEM images demonstrated that the TW particles without Chl had irregular shapes and sizes of 0.8-12 µm. The TW particles coated by the Chl presented shapes of quasi-rounded grains and smaller particle sizes of 0.8-1.8 µm. The photocatalytyic experiments showed that the photocatalyst powders containing Chl removed completely the RhB dye from the water after 2h under UV-VIS light, while the photocatalyst without Chl removed a maximum of 95% of the RhB. Interestingly, the TW/Bcap and TW + Chl/Bcap composites removed 94-100% of the RhB after 2h. Those ones removed such dye by photocatalysis and by physical adsorption at the same time (as confirmed by the absorbance and FTIR measurements), therefore, the removal of RhB was still very high. Scavenger experiments were also achieved and found that the •OH radicals are the main oxidizing species generated by the photocatalysts with and without Chl. The •O2- radicals and holes (h+) were the secondary oxidizing species. The presence of the chlorophyll on the photocatalyst increased in general the light absorption and the photocurrent. Overall, our work demonstrated that making composites with recycled plastic bottle caps is a feasible alternative to remove dyes from contaminated drinking water with high efficiency and low cost.


Subject(s)
Drinking Water , Catalysis , Chlorophyll , Coloring Agents , Plastics , Rhodamines , Titanium
5.
Sci Total Environ ; 807(Pt 2): 150820, 2022 Feb 10.
Article in English | MEDLINE | ID: mdl-34627879

ABSTRACT

Global concern about environmental pollution has increased in recent times due to the cumulative harmful impact on the human health occasioned by the diverse toxic substances released into the environment. Water reduced availability for human consumption and its pollution have been paid so much attention due to their relevance in agricultural and industrial activities. In this context, the advanced oxidation processes for removing contaminants from water, more specifically photocatalytic processes, have displayed their usefulness due to features such as easy application, low-cost, harmless effects and sustainable decontamination efficiency. This timely review is centered on worldwide studies, where efforts aimed at employing recycled materials as supports for purification applications such as the removal of different contaminants (dyes, pharmaceutical contaminants, and heavy metals) dissolved in aqueous environments have been reported. Materials like polyethylene terephthalic (PET), polystyrene (PS), disposal textile fabrics, newspapers, aluminum soda cans, rubber, waste electronic and electric components and used batteries have been employed either as supports for immobilizing catalysts or as photocatalysts. The present work offers a discussion of the ways through which photocatalytic composites have been immobilized or produced, employed characterization techniques, removal efficiencies achieved during photocatalytic degradation and possible degradation mechanism of pollutants; not only the highlights of all these studies are discussed, but also paths for future research works that could help improve the reported results are suggested. These new practical tools stand as novel sustainable strategies for the removal of emerging contaminants reusing waste flexible materials.


Subject(s)
Electronics , Water , Humans
6.
Int J Cardiol Heart Vasc ; 35: 100846, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34386574

ABSTRACT

Background Coronary heart disease has multiple risk factors, including air pollution. Numerous pathophysiological mechanisms have been identified with increasing levels of air pollution, mainly with ozone (O3), nitrogen dioxide (NO2), sulphur dioxide (SO2), particulate matter (PM10), fine particulate matter (PM2.5) and carbon monoxide (CO). In Mexico, the pollution level is reported using an air quality index called IMECA. Methods All patients with STEMI admitted at Hospital Español were collected between 2012 and 2019 (N = 348). We conducted a retrospective analysis using the air pollution exposure at the time of each event (lag0), the previous 24 h (lag1), 48 h (lag2), 72 h (lag3) and 5-day cumulative lag. The level of air pollution was analyzed independently using IMECA and particle concentrations. The data was divided in two groups: days with one of more STEMI's (MI group) and days free of events (Control group), using ANCOVA to evaluate the difference between means of both groups taking into account confounders. Results: For days with one or more cardiovascular event, a significant increase in SO2 was observed at lag1; similar increase was found in CO, PM2.5, SO2 at lag2. For the 5-day cumulative lag, SO2 and PM2.5 showed a significant increase. No differences were found using the IMECA levels in both groups. Conclusions: The elevated concentrations levels of CO, SO2 and PM2.5 showed significant association with STEMI at different time points before the event. Ozone, PM10 and NO2 showed no difference between groups. IMECA levels showed no association with STEMI in our study.

7.
Tob Control ; 25(5): 551-7, 2016 09.
Article in English | MEDLINE | ID: mdl-26307052

ABSTRACT

INTRODUCTION: Tobacco smoking is among the leading causes of preventable mortality worldwide. We assessed the impact of smoking on life expectancy worldwide between 1980 and 2010. METHODS: We retrieved cause-specific mortality data from the WHO Mortality Database by sex, year and age for 63 countries with high or moderate quality data (1980-2010). Using the time of the peak of the smoking epidemic by country, relative risks from the three waves of the Cancer Prevention Study were applied to calculate the smoking impact ratio and population attributable fraction. Finally, we estimated the potential gain in life expectancy at age 40 if smoking-related deaths in middle age (40-79 years) were eliminated. RESULTS: Currently, tobacco smoking is related to approximately 20% of total adult mortality in the countries in this study (24% in men and 12% in women). If smoking-related deaths were eliminated, adult life expectancy would increase on average by 2.4 years in men (0.1 in Uzbekistan to 4.8 years in Hungary) and 1 year in women (0.1 in Kyrgyzstan to 2.9 years in the USA). The proportion of smoking-related mortality among men has declined in most countries, but has increased in the most populous country in the world, that is, China from 4.6% to 7.3%. Increases in the impact of tobacco on life expectancy were observed among women in high-income countries. CONCLUSIONS: Recent trends indicate a substantial rise in the population-level impact of tobacco smoking on life expectancy in women and in middle-income countries. High-quality local data are needed in most low-income countries.


Subject(s)
Cigarette Smoking/adverse effects , Global Health/statistics & numerical data , Life Expectancy/trends , Adult , Aged , Cigarette Smoking/epidemiology , Developed Countries/statistics & numerical data , Developing Countries/statistics & numerical data , Female , Global Health/trends , Humans , Male , Middle Aged , Sex Factors , Smoking/epidemiology , Smoking/mortality
8.
J Immunoassay Immunochem ; 33(1): 59-65, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22181821

ABSTRACT

A commercially available multi-antigen lateral flow assay (LFA) for detection of antibodies to Mycobacterium bovis was evaluated by testing dairy cattle in Baja California, México. Sera and tissue samples were obtained from 268 dairy cattle at a slaughterhouse and were tested by LFA, bacteriological culture, and polymerase chain reaction (PCR). Of 107 culture positive samples, 70 (65.4%) were positive by PCR and 49 (45.8%) were positive by LFA. The PCR and LFA gave positive results with an additional 59 (36.6%) and 77 (47.8%) of the 161 culture negative samples, respectively. The false negative rate for the PCR was 34.6% and 54.2% for the LFA. Due to the high false positive rate for both PCR and LFA observed in this study, the LFA cannot be a useful test, even in combination with PCR.


Subject(s)
Antibodies, Bacterial/analysis , Immunoassay/methods , Tuberculosis, Bovine/diagnosis , Animals , Antibodies, Bacterial/blood , Antibodies, Bacterial/immunology , Cattle , Dairying , Mycobacterium bovis/genetics , Mycobacterium bovis/immunology , Polymerase Chain Reaction , Tuberculosis, Bovine/blood , Tuberculosis, Bovine/immunology , Tuberculosis, Bovine/microbiology
9.
Am J Physiol Cell Physiol ; 298(6): C1353-62, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20147652

ABSTRACT

We report a novel form of modulation of T-type calcium currents carried out by the neuronal actin-binding protein (ABP) Kelch-like 1 (KLHL1). KLHL1 is a constitutive neuronal ABP localized to the soma and dendritic arbors; its genetic elimination in Purkinje neurons leads to dendritic atrophy and motor insufficiency. KLHL1 participates in neurite outgrowth and upregulates voltage-gated P/Q-type calcium channel function; here we investigated KLHL1's role as a modulator of low-voltage-gated calcium channels and determined the molecular mechanism of this modulation with electrophysiology and biochemistry. Coexpression of KLHL1 with Ca(V)3.1 or Ca(V)3.2 (alpha(1G) or alpha(1H) subunits) caused increases in T-type current density (35%) and calcium influx (75-83%) when carried out by alpha(1H) but not by alpha(1G). The association between KLHL1 and alpha(1H) was determined by immunoprecipitation and immunolocalization in brain membrane fractions and in vitro in HEK-293 cells. Noise analysis showed that neither alpha(1H) single-channel conductance nor open probability was altered by KLHL1, yet a significant increase in channel number was detected and further corroborated by Western blot analysis. KLHL1 also induced an increase in alpha(1H) current deactivation time (tau(deactivation)). Interestingly, the majority of KLHL1's effects were eliminated when the actin-binding motif (kelch) was removed, with the exception of the calcium influx increase during action potentials, indicating that KLHL1 interacts with alpha(1H) and actin and selectively regulates alpha(1H) function by increasing the number of alpha(1H) channels. This constitutes a novel regulatory mechanism of T-type calcium currents and supports the role of KLHL1 in the modulation of cellular excitability.


Subject(s)
Actins/metabolism , Calcium Channels, T-Type/metabolism , Calcium/metabolism , Cerebellum/metabolism , Hippocampus/metabolism , Microfilament Proteins/metabolism , Neurons/metabolism , Action Potentials , Amino Acid Motifs , Animals , Blotting, Western , Calcium Channels, T-Type/genetics , Cell Line , Cerebellum/cytology , Fluorescent Antibody Technique , Hippocampus/cytology , Humans , Immunoprecipitation , Ion Channel Gating , Kinetics , Mice , Microfilament Proteins/genetics , Mutation , Patch-Clamp Techniques , Protein Structure, Tertiary , Recombinant Fusion Proteins/metabolism , Transfection , Up-Regulation
10.
Neuroscience ; 145(3): 841-50, 2007 Mar 30.
Article in English | MEDLINE | ID: mdl-17289272

ABSTRACT

The actin-binding protein Kelch-like 1 (KLHL1) is a neuronal protein that belongs to the evolutionarily-conserved Kelch protein super-family. The mammalian KLHL1 is brain-specific, cytosolic and can form multimers and bind actin filaments. KLHL1's function is likely that of an actin-organizing protein, possibly modulating neurite outgrowth, the dynamic morphology of dendritic spine heads; or anchoring proteins essential for post-synaptic function, like ion channels. Targeted deletion of the KLHL1 gene in Purkinje neurons results in dendritic deficits in these neurons, abnormal gait, and progressive loss of motor coordination in mice [He Y, Zu T, Benzow KA, Orr HT, Clark HB, Koob MD (2006) Targeted deletion of a single SCA8 ataxia locus allele in mice causes abnormal gait, progressive loss of motor coordination, and Purkinje cell dendritic deficits. J Neurosci 26:9975-9982]. Here we tested the hypothesis that KLHL1 may interact and modulate voltage-gated calcium channels by assessing the interaction of the principal subunit of P/Q-type channels, alpha(1A), with KLHL1. Experiments in human embryonic kidney line HEK 293 (HEK) cells and cerebellar primary cultures revealed co-incidence of alpha(1A) and KLHL1 immunoreactivity when testing both the endogenous or epitope-tagged versions of the proteins. Similarly, co-immunoprecipitation experiments in HEK cells and brain tissue exposed the presence of KLHL1 in protein samples immunoprecipitated with FLAG-tagged or alpha(1A) antibodies. Functional studies of KLHL1 on P/Q-type current properties probed with whole-cell patch clamp revealed a significant increase in mean current density in the presence of KLHL1 (80% increase; from -13.2+/-2.0 pA/pF to -23.7+/-4.2 pA/pF, P<0.02), as well as a shift in steady state activation V(50) of -5.5 mV (from 12.8+/-1.8 mV to 7.3+/-1.0 mV, P<0.02). Our data are consistent with a modulatory effect of KLHL1 on the P/Q-type calcium channel function and suggest a possible novel role for KLHL1 in cellular excitability.


Subject(s)
Calcium Channels, N-Type/physiology , Cerebellum/physiology , Microfilament Proteins/physiology , Neurons/physiology , Action Potentials/physiology , Calcium , Cell Line , Cells, Cultured , DNA, Complementary/genetics , Dendrites/physiology , Dendrites/ultrastructure , Humans , Kidney , Kinetics , Microfilament Proteins/genetics , Neurites/physiology , Spinocerebellar Ataxias , Synapses/physiology , Transfection
11.
J Neurosci ; 21(23): 9185-93, 2001 Dec 01.
Article in English | MEDLINE | ID: mdl-11717352

ABSTRACT

The expansion of polyglutamine tracts encoded by CAG trinucleotide repeats is a common mutational mechanism in inherited neurodegenerative diseases. Spinocerebellar ataxia type 6 (SCA6), an autosomal dominant, progressive disease, arises from trinucleotide repeat expansions present in the coding region of CACNA1A (chromosome 19p13). This gene encodes alpha(1A), the principal subunit of P/Q-type Ca(2+) channels, which are abundant in the CNS, particularly in cerebellar Purkinje and granule neurons. We assayed ion channel function by introduction of human alpha(1A) cDNAs in human embryonic kidney 293 cells that stably coexpressed beta(1) and alpha(2)delta subunits. Immunocytochemical analysis showed a rise in intracellular and surface expression of alpha(1A) protein when CAG repeat lengths reached or exceeded the pathogenic range for SCA6. This gain at the protein level was not a consequence of changes in RNA stability, as indicated by Northern blot analysis. The electrophysiological behavior of alpha(1A) subunits containing expanded (EXP) numbers of CAG repeats (23, 27, and 72) was compared against that of wild-type subunits (WT) (4 and 11 repeats) using standard whole-cell patch-clamp recording conditions. The EXP alpha(1A) subunits yielded functional ion channels that supported inward Ca(2+) channel currents, with a sharp increase in P/Q Ca(2+) channel current density relative to WT. Our results showed that Ca(2+) channels from SCA6 patients display near-normal biophysical properties but increased current density attributable to elevated protein expression at the cell surface.


Subject(s)
Calcium Channels/genetics , Calcium Channels/metabolism , Protein Subunits , Spinocerebellar Ataxias/etiology , Trinucleotide Repeat Expansion/genetics , Blotting, Northern , Calcium/metabolism , Calcium Channels, P-Type/genetics , Calcium Channels, P-Type/metabolism , Calcium Channels, Q-Type/genetics , Calcium Channels, Q-Type/metabolism , Cell Line , Cell Membrane/metabolism , Chromosomes, Human, Pair 19/genetics , DNA, Complementary/genetics , DNA, Complementary/metabolism , Gene Expression , Genes, Dominant , Humans , Immunohistochemistry , Ion Transport/genetics , Kidney/cytology , Kidney/metabolism , Patch-Clamp Techniques , RNA, Messenger/metabolism , Spinocerebellar Ataxias/metabolism , Transfection
12.
Neuron ; 28(1): 221-31, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11086996

ABSTRACT

Functional presynaptic vesicles have been subdivided into readily releasable (RRP) and reserve (RP) pools. We studied recycling properties of RRP vesicles through differential retention of FM1-43 and FM2-10 and by varying the time window for FM dye uptake. Both approaches indicated that vesicles residing in the RRP underwent rapid endocytosis (tau approximately 1s), whereas newly recruited RP vesicles were recycled slowly (tau approximately 30 s). With repeated challenges (hypertonic or electrical stimuli), the ability to release neurotransmitter recovered 10-fold more rapidly than restoration of FM2-10 destaining. Finding neurotransmission in the absence of destaining implied that rapidly endocytosed RRP vesicles were capable of reuse, a process distinct from repopulation from the RP. Reuse would greatly expand the functional capabilities of a limited number of vesicles in CNS terminals, particularly during intermittent bursts of activity.


Subject(s)
Hippocampus/metabolism , Synapses/metabolism , Synaptic Vesicles/metabolism , Action Potentials/physiology , Animals , Cells, Cultured , Electric Stimulation , Endocytosis/physiology , Exocytosis/drug effects , Exocytosis/physiology , Fluorescent Dyes , Hippocampus/cytology , Hypertonic Solutions/pharmacology , Models, Neurological , Neurotransmitter Agents/metabolism , Pyridinium Compounds , Quaternary Ammonium Compounds , Rats , Rats, Sprague-Dawley , Synaptic Transmission/physiology
13.
Proc Natl Acad Sci U S A ; 96(26): 15245-50, 1999 Dec 21.
Article in English | MEDLINE | ID: mdl-10611370

ABSTRACT

The Ca(2+) channel alpha(1A)-subunit is a voltage-gated, pore-forming membrane protein positioned at the intersection of two important lines of research: one exploring the diversity of Ca(2+) channels and their physiological roles, and the other pursuing mechanisms of ataxia, dystonia, epilepsy, and migraine. alpha(1A)-Subunits are thought to support both P- and Q-type Ca(2+) channel currents, but the most direct test, a null mutant, has not been described, nor is it known which changes in neurotransmission might arise from elimination of the predominant Ca(2+) delivery system at excitatory nerve terminals. We generated alpha(1A)-deficient mice (alpha(1A)(-/-)) and found that they developed a rapidly progressive neurological deficit with specific characteristics of ataxia and dystonia before dying approximately 3-4 weeks after birth. P-type currents in Purkinje neurons and P- and Q-type currents in cerebellar granule cells were eliminated completely whereas other Ca(2+) channel types, including those involved in triggering transmitter release, also underwent concomitant changes in density. Synaptic transmission in alpha(1A)(-/-) hippocampal slices persisted despite the lack of P/Q-type channels but showed enhanced reliance on N-type and R-type Ca(2+) entry. The alpha(1A)(-/-) mice provide a starting point for unraveling neuropathological mechanisms of human diseases generated by mutations in alpha(1A).


Subject(s)
Ataxia , Calcium Channels, P-Type/metabolism , Calcium Channels, Q-Type/metabolism , Calcium Channels/deficiency , Nerve Tissue Proteins/deficiency , Synaptic Transmission , Animals , Calcium/metabolism , Calcium Channels/genetics , Calcium Channels, N-Type , Cerebellum/metabolism , Electric Conductivity , Hippocampus/metabolism , Mice , Mice, Knockout , Nerve Tissue Proteins/genetics , Nervous System Diseases/etiology , Purkinje Cells/metabolism
14.
Proc Natl Acad Sci U S A ; 95(13): 7760-5, 1998 Jun 23.
Article in English | MEDLINE | ID: mdl-9636224

ABSTRACT

Many neurons of the central nervous system display multiple high voltage-activated Ca2+ currents, pharmacologically classified as L-, N-, P-, Q-, and R-type. Of these current types, the R-type is the least understood. The leading candidate for the molecular correlate of R-type currents in cerebellar granule cells is the alpha1E subunit, which yields Ca2+ currents very similar to the R-type when expressed in heterologous systems. As a complementary approach, we tested whether antisense oligonucleotides against alpha1E could decrease the expression of R-type current in rat cerebellar granule neurons in culture. Cells were supplemented with either antisense or sense oligonucleotides and whole-cell patch clamp recordings were obtained after 6-8 days in vitro. Incubation with alpha1E antisense oligonucleotide caused a 52.5% decrease in the peak R-type current density, from -10 +/- 0.6 picoamperes/picofarad (pA/pF) (n = 6) in the untreated controls to -4.8 +/- 0.8 pA/pF (n = 11) (P < 0.01). In contrast, no significant changes in the current expression were seen in sense oligonucleotide-treated cells (-11.3 +/- 3.2 pA/pF). The specificity of the alpha1E antisense oligonucleotides was supported by the lack of change in estimates of the P/Q current amplitude. Furthermore, antisense and sense oligonucleotides against alpha1A did not affect R-type current expression (-11.5 +/- 1.7 and -11.7 +/- 1.7 pA/pF, respectively), whereas the alpha1A antisense oligonucleotide significantly reduced whole cell currents under conditions in which P/Q current is dominant. Our results support the hypothesis that members of the E class of alpha1 subunits support the high voltage-activated R-type current in cerebellar granule cells.


Subject(s)
Calcium Channels/genetics , Cerebellum/drug effects , Neurons/drug effects , Oligonucleotides, Antisense/pharmacology , Animals , Calcium Channels/drug effects , Calcium Channels/physiology , Cells, Cultured , Cerebellum/physiology , Electrophysiology , Neurons/physiology , Rats , Thionucleotides/pharmacology
15.
Am J Physiol ; 272(4 Pt 2): H1791-7, 1997 Apr.
Article in English | MEDLINE | ID: mdl-9139964

ABSTRACT

The peptide hormone relaxin has direct, positive inotropic and chronotropic effects on rat hearts in vivo and in vitro. Relaxin's effects on the electrophysiological properties of single quiescent atrial cells from normal rats were investigated with a whole cell patch clamp. Relaxin had a significant inhibitory effect on outward potassium currents. The outward potassium current consisted of a transient component (I(to)) and a sustained component (I(S)). The addition of 100 ng/ml of relaxin inhibited the peak I(to) in a voltage-dependent manner (74% inhibition at a membrane potential of -10 mV to 30% inhibition at +70 mV). The time to reach peak I(to) and the apparent time constant of inactivation of I(to) were increased by relaxin. Dialysis with the protein kinase A inhibitor 5-24 amide (2 microM) prevented relaxin's effects, suggesting an obligatory role for this kinase in the relaxin-dependent regulation of the potassium current.


Subject(s)
Cyclic AMP-Dependent Protein Kinases/metabolism , Heart/physiology , Potassium Channels/physiology , Relaxin/pharmacology , Animals , Cells, Cultured , Female , Heart/drug effects , Heart Atria , Kinetics , Male , Membrane Potentials/drug effects , Patch-Clamp Techniques , Phosphorylation , Potassium Channels/drug effects , Rats , Rats, Inbred F344 , Time Factors
16.
Am J Physiol ; 272(4 Pt 2): H1798-803, 1997 Apr.
Article in English | MEDLINE | ID: mdl-9139965

ABSTRACT

Relaxin produces positive inotropic and chronotropic effects in rat hearts. The effect of relaxin on the action potential duration (APD) of single quiescent rat atrial cells was investigated with a whole cell patch clamp. Relaxin induced a significant, dose-dependent prolongation of the APD. This effect was maximal at 200 ng/ml (nominal concentration of 33.6 nM), which caused, on average, a 57% increase in the time taken to reach 90% repolarization. The effect of relaxin was blocked by the protein kinase A inhibitor 5-24 amide, indicating that its effect is mediated by an adenosine 3',5'-cyclic monophosphate-dependent mechanism. The increased APD induced by relaxin caused an enhanced entrance of calcium, with the charge carried through voltage-activated calcium channels increased by approximately 25%. This increase was not due to a direct modulation of calcium currents (20); rather, it was a consequence of the longer period of cellular depolarization. Our findings that relaxin increased the APD and therefore increased the calcium influx in atrial myocytes could explain the positive inotropic effects induced by relaxin in atrial preparations.


Subject(s)
Action Potentials/drug effects , Heart/physiology , Relaxin/pharmacology , 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology , Animals , Calcium/metabolism , Calcium Channels/drug effects , Calcium Channels/physiology , Cells, Cultured , Female , Heart/drug effects , Heart Atria , Kinetics , Male , Patch-Clamp Techniques , Phosphorylation , Protein Kinase C/metabolism , Rats , Rats, Inbred F344 , Time Factors
17.
Proc Natl Acad Sci U S A ; 94(26): 14936-41, 1997 Dec 23.
Article in English | MEDLINE | ID: mdl-9405717

ABSTRACT

Low voltage-activated, or T-type, calcium currents are important regulators of neuronal and muscle excitability, secretion, and possibly cell growth and differentiation. The gene (or genes) coding for the pore-forming subunit of low voltage-activated channel proteins has not been unequivocally identified. We have used reverse transcription-PCR to identify partial clones from rat atrial myocytes that share high homology with a member of the E class of calcium channel genes. Antisense oligonucleotides targeting one of these partial clones (raE1) specifically block the increase in T-current density that normally results when atrial myocytes are treated with insulin-like growth factor 1 (IGF-1). Antisense oligonucleotides targeting portions of the neuronal rat alpha1E sequence, which are not part of the clones detected in atrial tissue, also block the IGF-1-induced increase in T-current, suggesting that the high homology to alpha1E seen in the partial clone may be present in the complete atrial sequence. The basal T-current expressed in these cells is also blocked by antisense oligonucleotides, which is consistent with the notion that IGF-1 up-regulates the same gene that encodes the basal current. These results support the hypothesis that a member of the E class of calcium channel genes encodes a low voltage-activated calcium channel in atrial myocytes.


Subject(s)
Brain/metabolism , Calcium Channels/metabolism , Calcium/metabolism , Heart Atria/metabolism , Oligonucleotides, Antisense/genetics , Animals , Base Sequence , Calcium Channels/genetics , Cells, Cultured , Ion Transport/drug effects , Molecular Sequence Data , Oligonucleotides, Antisense/pharmacology , Rats , Rats, Sprague-Dawley
18.
Ginecol Obstet Mex ; 64: 523-7, 1996 Dec.
Article in Spanish | MEDLINE | ID: mdl-9019433

ABSTRACT

A descriptive, transversal retrospective study was performed, to determine the prevalence of HELLP syndrome among patients with Pregnancy-Induced Hypertension (PIH), who were admitted into the Gynecology and Obstetrics Service the American British Cowdray Hospital in Mexico City, since July 1992 to June 1995. We detected a total or 11 patients who had the diagnostic parameters proposed by Sibaí, those were 11.8% of all the patients with PIH. The medial gestational age was 33 weeks (range from 30 to 39) The mean tensional levels were 170/ 107 mm Hg, in base of platelet count, nine patients were classified as Class I (82%) and two in Class II (18%), the medial peak levels of transaminases and bilirubins was reached 40 hours and that of lactic deshidrogenase 60 hours after the diagnosis was established, while the minimum levels of hematocrit and platelets were at 48 and 57 respectively. The mean weight of the neonates was 1,655 g, the maternal mortality rate was 9% and the perinatal 8.3%, the diagnosis of HELLP syndrome was established before delivery in 40% of the cases and after that in 60%, puerperal HELLP may occur more frequently that is believed. Point out the importance of early detection of this clinic entity in order to establish an opportune and efficient treatment which improves maternal and fetal prognosis.


Subject(s)
HELLP Syndrome/epidemiology , Hypertension/epidemiology , Pregnancy Complications, Cardiovascular/epidemiology , Adult , Female , HELLP Syndrome/blood , Humans , Hypertension/blood , Infant, Newborn , Pregnancy , Pregnancy Complications, Cardiovascular/blood , Prevalence , Retrospective Studies
19.
Ginecol Obstet Mex ; 64: 64-72, 1996 Feb.
Article in Spanish | MEDLINE | ID: mdl-8714066

ABSTRACT

The HELLP syndrome is an English acronym, for describing patients with Pregnancy Induced Hypertension (PIH), who also has hemolysis, elevated hepatic enzymes and low platelets, its presence is associated with a frequency of maternal mortality from 5 to 25% and when it is associated with hepatic rupture it increases to 35% and a perinatal one from 30 to 60%. It is present in 2 to 12% among women with PIH. Its etiology has not been elucidated completely, the base of its pathophysiology is an unbalance in prostanoid metabolism which conduces to generalize vasopasm with the subsequent endothelial damage and platelets activation. Sibaí describes the diagnostic parameters of the syndrome. Its initial treatment is the hemodinamic stabilization of the maternal status and the evaluation of fetal well-being for decide whether immediate delivery is indicated. HELLP appears in the puerperium in 30% of the cases. There are both maternal and perinatal severe complications, and a recurrence risk of a 4 to 27%. We emphasize the importance of early detection of the syndrome which improves maternal-fetal prognosis.


Subject(s)
HELLP Syndrome/mortality , Female , HELLP Syndrome/complications , HELLP Syndrome/diagnosis , Humans , Infant, Newborn , Maternal Mortality , Maternal-Fetal Exchange , Mexico/epidemiology , Pregnancy , Prognosis , Recurrence , Time Factors
20.
Ginecol Obstet Mex ; 63: 448-51, 1995 Nov.
Article in Spanish | MEDLINE | ID: mdl-8537033

ABSTRACT

Two extreme cases of pregnancy-induced hypertension with puerperal HELLP syndrome are presented and the literature is review. HELLP is an English acronym, for describing the preeclamptic or eclamptic patient, who also has hemolysis, elevated hepatic enzymes and low platelets. Its etiology has not been elucidated, but it has been accepted the theory of dysequilibrium in prostanoid metabolism. It has an incidence of 5 to 15% among patients with pregnancy-induced hypertension. Maternal mortality is about 10 to 28% and neonatal of 40%. Owing to fatal complications, treatment consist of interrupting pregnancy. Point out the importance of early detection of this clinic entity, which improves maternal-fetal prognosis.


Subject(s)
HELLP Syndrome , Puerperal Disorders , Adult , Cesarean Section , Female , Fetal Death/etiology , HELLP Syndrome/diagnosis , Humans , Infant, Newborn , Pregnancy , Prognosis
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