Influence of spontaneous calcium events on cell-cycle progression in embryonal carcinoma and adult stem cells.

Spontaneous Ca(2+) events have been observed in diverse stem cell lines, including carcinoma and mesenchymal stem cells. Interestingly, during cell cycle progression, cells exhibit Ca(2+) transients during the G(1) to S transition, suggesting that these oscillations may play a role in cell cycle progression. We aimed to study the influence of promoting and blocking calcium oscillations in cell proliferation and cell cycle progression, both in neural progenitor and undifferentiated cells. We also identified which calcium stores are required for maintaining these oscillations. Both in neural progenitor and undifferentiated cells calcium oscillations were restricted to the G1/S transition, suggesting a role for these events in progression of the cell cycle. Maintenance of the oscillations required calcium influx only through inositol 1,4,5-triphosphate receptors (IP(3)Rs) and L-type channels in undifferentiated cells, while neural progenitor cells also utilized ryanodine-sensitive stores. Interestingly, promoting calcium oscillations through IP(3)R agonists increased both proliferation and levels of cell cycle regulators such as cyclins A and E. Conversely, blocking calcium events with IP(3)R antagonists had the opposite effect in both undifferentiated and neural progenitor cells. This suggests that calcium events created by IP(3)Rs may be involved in cell cycle progression and proliferation, possibly due to regulation of cyclin levels, both in undifferentiated cells and in neural progenitor cells.

Improved detail in biological soft X-ray microscopy: study of blood platelets.

Improved image quality in soft x-ray contact microscopy can be obtained by examining the resist with transmission rather than scanning electron microscopy. Application of the new technique to air-dried preparations of human blood platelets reveals structures not visible in the same cells with transmission electron microscopy or when the resist is examined by scanning electron microscopy. As seen by the new technique, platelet pseudopods contain a central structure connected to a network in the platelet and dense bodies exhibit a lamellar structure.

Serotonin storage in platelets: estimation of storage-packet size.

Storage-body diameter and volume, and the number of molecules of serotonin contained in a storage body, were estimated for blood platelets. In the human, 5.23 x 10(5) molecules of serotonin are contained in a storage body 198 nanometers in diameter, while in the cat, 31.2 x 10(5) molecules of this amine are contained in a storage body 298 nanometers in diameter.

Fluorinated molecule as a tracer: difluoroserotonin in human platelets mapped by electron energy-loss spectroscopy.

The intracellular distribution of fluorine has been delineated in human platelets incubated with 4,6-difluoroserotonin, utilizing a scanning-transmission electron microscope equipped with an energy-loss spectrometer. Discrete intracellular structures corresponding in location to dense bodies contained high concentrations of fluorine. Electron energy-loss spectroscopy, which apparently can detect less than 10(-20) gram of fluorine in an area of 10 square nonometers, can thus localize fluorinated tracer molecules with biological activity.

[Adolescent drug use. Ethical dilemma in the diagnostic-therapeutic approach]. / Consumo de drogas en adolescentes. Dilema ético en el abordaje diagnóstico-terapéutico.

Illegal drug use among adolescents has increased in recent years in Spain, as well as has the risk behaviours and problems typical of adolescence. The results of studies on drug use during this stage of life reveal the serious and wide-ranging consequences that can arise. Emergency services are often the first to receive and deal with these and its professionals must face situations that pose contradictions between two of the basic ethical principles, the principle of autonomy and the principle of beneficence; an ethical dilemma that is addressed in this work.

Prevalence of cocaine and derivatives in blood and urine samples of trauma patients and correlation with injury severity: a prospective observational study.

PURPOSE: The abuse of cocaine and its derivatives presents a likely risk factor for injury. Trauma incurred by cocaine and derivative abusers may be more severe than that incurred by non-users. OBJECTIVES: To ascertain the presence of cocaine and its derivatives in trauma patients and to correlate RTS (Revised Trauma Score) and ISS (Injury Severity Score) with the presence of cocaine and its derivatives in blood and urine samples. METHODS: All trauma victims treated in an emergency unit between November 11, 2012 and September 15, 2013 were included in the study. Blood and urine samples were collected on admission to hospital. RTS and ISS scores were then compared with the presence or absence of cocaine and its derivatives in the samples. The associations between RTS < 7.84 and ISS > 16 and the independent variables were evaluated by the gross odds ratio values, determined by univariate logistic regression. Multivariate analysis was performed using multivariate logistic regression. RESULTS: Of 453 patients (83.7% male) included in the study, 28.6% presented ISS > 16 and 33.6% presented RTS < 7.84. A total of 435 samples were collected, and 86 (19.8%) provided positive samples for cocaine, 48 (11%) for crack and 69 (15.9%) for cocaethylene. Compared to other patients, drug users showed a greater probability of RTS < 7.84 (2.18 times greater) and a greater probability of ISS > 16 (1.76 times greater). CONCLUSION: For the trauma patients included in our study, the use of cocaine and its derivatives was shown to be associated with more severe traumas, as demonstrated by their RTS and ISS scores.

First detection of Corynebacterium ulcerans producing a diphtheria-like toxin in a case of human with pulmonary infection in the Rio de Janeiro metropolitan area, Brazil.

The frequency and severity of human infections associated with Corynebacterium ulcerans appear to be increasing in different countries. Here, we describe the first C. ulcerans strain producing a diphtheria-like toxin isolated from an elderly woman with a fatal pulmonary infection and a history of leg skin ulcers in the Rio de Janeiro metropolitan area.

Use of multimetric indices to classify estuaries with different hydromorphological characteristics and different levels of human pressure.

The assessment of estuaries based on benthic communities is widely used to determine impacts caused by human pressure and is one of the required tools for the implementation of the European Water Framework Directive (WFD). Our study compared multimetric approaches (B-IBI and TICOR) to assess the benthic condition of three Portuguese estuaries (Mondego, Tejo, and Mira rivers) with different levels of natural and human induced stress. Benthic community condition was classified into quality status categories of the WFD and compared for consistency with a priori status categories based upon physical-chemical criteria. Both multimetric indices discriminated equally well between locations classified above or below the good status category but were unable to provide good separation between other quality classes (high/good, moderate, poor/bad). Metrics included in these indices are greatly affected by natural stress and we recommend the development of habitat-specific thresholds to increase the discriminatory ability of any benthic condition index.

Influence of seasonal variability in benthic invertebrate community structure on the use of biotic indices to assess the ecological status of a Portuguese estuary.

The present study focused on the use of benthic invertebrate communities to assess the ecological quality of a Portuguese estuary characterized by strong seasonal changes and with eutrophication problems. Seasonal benthic samples were collected during a flood year and the methodology proposed by the WFD Portuguese group was used to classify benthic assemblages into five different quality classes. Factor analysis was applied to classify stations based on their physical-chemical status. Different classifications were obtained with different indices and among seasons and there was low agreement between indices and index-season interactions. Diversity indices were better correlated to eutrophication related variables than AMBI and ABC method. Predictable responses of benthic indices to anthropogenic stress symptoms were stronger during the dry period.

[Ivermectin as an adjunct in the treatment of refractory epilepsy]. / Ivermectina como coadyuvante en la epilepsia refractaria.

INTRODUCTION: Ivermectin, a 22'23 dihydro derivative of avermectins beta-1a, is a highly effective veterinary and human anti parasitic, used to treat endoparasites of difficult control such as filariasis and onchocerciasis, with a median plasma life of at least of 16 hours. The recommended therapeutic doses range from 0.05 to 0.40 mg/kg, without undesirable effects or risk to human life. It went from being a great success in animal health to its application in humans, where it has had great impact. Studies in basic sciences have shown that ivermectin has anticonvulsive effects in different epileptic animal models, where five different mechanisms of action have been described. PATIENTS AND METHODS: Descriptive, prospective observational study, performed between 2013 and 2015, with 32 refractory epileptic patients, who received ivermectin as an a dose of adjunctive treatment of 10 mg/day three or seven times a week, controlled every three months, followed by 12-24 months, without withdrawal of anticonvulsant medications that they received previously. RESULTS: Progressively, patients entered into crisis control, at the end of the programmed follow-up period, the total percentage of crisis reduction was 97%, of which 57% did not return to crisis from the beginning of treatment, all patients being free of crisis according to International League Against Epilepsy criteria. CONCLUSION: Ivermectin has been useful as an adjuvant, achieving a significant decrease in seizures in this group of drug resistant patients.

TITLE: Ivermectina como coadyuvante en la epilepsia refractaria.Introduccion. La ivermectina es un 22'23 dihidroderivado de las avermectinas beta-1a, un antiparasitario de uso veterinario y humano de gran eficacia, utilizado para tratar endoparasitos de dificil control, como la filariasis y la oncocercosis. Tiene una vida media plasmatica de al menos 16 horas. Las dosis terapeuticas recomendadas varian entre 0,05 y 0,40 mg/kg, sin efectos indeseados ni riesgo para la vida humana. Paso de ser un gran exito en sanidad animal a su aplicacion en seres humanos, donde ha tenido gran impacto. Estudios en ciencias basicas han demostrado que la ivermectina tiene efectos anticonvulsionantes en diferentes modelos animales epilepticos, donde se han descritos cinco diferentes mecanismos de accion. Pacientes y metodos. Estudio descriptivo, observacional prospectivo, realizado entre 2013 y 2015, con 32 pacientes epilepticos refractarios, quienes recibieron ivermectina como tratamiento coadyuvante en dosis de 10 mg/dia, tres o siete veces por semana, controlados cada tres meses, seguidos durante 12-24 meses, sin retirada de los medicamentos anticonvulsionantes que recibian previamente. Resultados. Progresivamente, los pacientes entraron en control de las crisis. Al final del periodo de seguimiento programado, el porcentaje total de reduccion de las crisis fue del 97%. El 57% de estos pacientes no volvio a presentar crisis desde el inicio del tratamiento, y todos los pacientes se encontraron libres de crisis segun los criterios de la Liga Internacional contra la Epilepsia. Conclusion. La ivermectina ha sido util como coadyuvante y ha logrado una significativa disminucion de crisis en este grupo de pacientes farmacorresistentes.

Association of paradoxical sleep deprivation and ecstasy (MDMA) enhances genital reflexes in male rats.

Ecstasy ((+/-)3,4-methylenedioxymethamphetamine, MDMA) is a psychostimulant and a synthetic derivative of amphetamine that, according to its consumers, promotes the enhancement of sexual pleasure. This study sought to investigate the effects of ecstasy in the genital reflexes of paradoxical sleep deprived (PSD) male rats. Distinct groups of PSD rats were administered with saline or different doses of ecstasy. The incidence of genital reflexes was verified for 100 min. The four doses that were used induced genital reflexes in PSD animals and these significantly differed from their respective treated control groups. Under the influence of two intermediary doses (2.5 and 5mg/kg), all animals displayed erection and ejaculation. The frequency of genital reflexes was also significantly greater than in relation to the PSD-saline group. The comparison between cocaine and ecstasy in PSD rats revealed that ecstasy induced more erections and ejaculations than cocaine. Thus, the present results showed a great enhancement of the genital reflexes of PSD rats that might have occurred due to serotoninergic alterations induced by this illicit substance when associated to sleep deprivation.

Aggregation of model asphaltenes: a molecular dynamics study.

Natural asphaltenes are defined as polyaromatic compounds whose chemical composition and structure are dependent on their geological origin and production history, hence are regarded as complex molecules with aromatic cores and aliphatic tails that occur in the heaviest fraction of crude oil. The aggregation of asphaltenes presents a range of technical challenges to the production and processing of oil. In this work we study the behaviour of the model asphaltene-like molecule hexa-tert-butylhexa-peri-hexabenzocoronene (HTBHBC) using molecular dynamics simulation. It was found that the regular arrangement of the tert-butyl side chains prevents the formation of strongly-bound dimers by severely restricting the configurational space of the aggregation pathway. In contrast, a modified molecule with only 3 side chains is readily able to form dimers. This work therefore confirms the influence of the molecular structure of polyaromatic compounds on their aggregation mechanism, and reveals the unexpected design rules required for model systems that can mimic the behavior of asphaltenes.

[Otitis medias with effusion: association with the Eustachian tube dysfunction and adenoiditis. The case of the Central Hospital of Maputo]. / Otitis medias con derrame: asociación con el síndrome de disfunción tubárica y las adenoiditis. El caso del Hospital Central de Maputo.

INTRODUCTION: Although the aetiology of otitis media is known to be multifactorial, adenoids infections and Eustachian tube dysfunction, have been frequently associated with the incidence of middle-ear effusion. Middle-ear effusion cases are frequent in Maputo, Mozambique, and very often insertion of tympanostomy tubes and adenoidectomy alone or with amigdalectomy have been used to treat these cases and to prevent further episodes. The objective of this study is to describe the association of these factors with otitis medias with effusion in patients that visit the Otorrinolaringology department (ENT) at the Central Hospital of Maputo (HCM), as well as to describe the clinical and epidemiological profile of these patients. PATIENTS AND METHODS: A cross sectional study was conducted. 4157 clinical files of all patients who made their first visit to the ENT department at the HCM, with otitis media during a period of 4 years (1995 to 1998). RESULTS: 23.3% of patients who visited the ORL service of Maputo with otitis media, are children under 3 years; the major proportion of otitis media with effusion was observed in children aged from 3 to 7 years old (49.2%). In boys under, otitis media with effusion is strongly associated with the history of adenoiditis and/or Eustachian tube dysfunction (OR=9.53) and in older patients (OR=12.26). CONCLUSION: The proportion of otitis media with effusion increases more evidently in patients with disfuntion tube syndrome. Other factor that can be important in patients under seven, is the presence of adenoiditis.

Performance of calves born in different periods of the calving season in intensive beef cattle farming / [Desempenho em pecuária de corte intensiva de progênies nascidas em diferentes períodos da estação de parição]

The objective of this study was to evaluate, for two years, the performance of 124 female and 105 male Braford calves born during the first and second halves of the same calving season and the effects of birth period on the development of males until slaughter, as yearlings, and of females until calving, after having mated at 13-15 months of age. Early-born females were heavier than those born late at weaning (119.3 vs 109.9kg; P<0.05), at the start of the breeding season (275.0 vs 263.0kg; P<0.05), and at the end of the breeding season (300.0 vs 289.5kg; P<0.05), in addition to being more fertile (70 vs 50% pregnancy rate). There was no difference (P>0.05) in the development of males born early in relation to those born late, except for weaning weight, which was higher in the former. Steers born early were ready for slaughter at a younger age (459.6 vs 490.1 days; P<0.05), and both groups (early- and late-born) had a body condition classified as fat (4.21 points). In intensive production systems, both male and female calves perform better if they are born during the first half of the calving season.(AU)

O objetivo deste estudo foi avaliar, por dois anos, o desempenho de 124 bezerras e 105 bezerros Braford nascidos durante a primeira e segunda metades da mesma estação, bem como os efeitos do período de nascimento no desenvolvimento dos machos até o abate e das fêmeas até o primeiro parto, após serem acasalados entre 13/15 meses de idade. As fêmeas nascidas precocemente foram mais pesadas do que as nascidas tardiamente ao desmame quando bezerras (119,3 vs. 109,9kg; P<0,05), no início da estação reprodutiva (275,0 vs. 263,0kg; P<0,05) e no final da estação reprodutiva (300,0 vs. 289,5kg; P<0,05), além de terem maior fertilidade (taxa de prenhez 70 vs. 50%). Não houve diferença (P>0,05) no desenvolvimento de bezerros nascidos precocemente em relação aos nascidos mais tardiamente, exceto no peso ao desmame, com superioridade dos primeiros. Os novilhos nascidos mais cedo ficaram prontos para o abate à idade mais jovem (459,6 vs. 490,1 dias; P<0,05), e ambos os grupos (nascidos precoce e tardiamente) tinham uma condição corporal classificada como gordura (4,21 pontos). Em sistemas de produção intensiva, os bezerros machos e fêmeas nascidos precocemente, na primeira metade da estação de parição, possuem melhor desempenho.(AU)

Effects of ayahuasca on the development of ethanol-induced behavioral sensitization and on a post-sensitization treatment in mice.

BACKGROUND: Hallucinogenic drugs were used to treat alcoholic patients in the past, and recent developments in the study of hallucinogens led to a renewal of interest regarding the application of these drugs in the treatment of addiction. In this scenario, accumulating evidence suggests that the hallucinogenic brew ayahuasca (Aya) may have therapeutic effects on substance abuse problems. METHODS: We investigated the effects of Aya on spontaneous locomotor activity and ethanol(Eth)-induced hyperlocomotion and subsequent locomotor sensitization by a two-injection protocol. Additionally, we tested the effect of Aya on an 8-day counter-sensitization protocol to modify sensitized responses induced by a repeated treatment with Eth (1.8g/kg) for 8 alternate days. RESULTS: Aya showed high sensitivity in preventing the development of Eth-induced behavioral sensitization, attenuating it at all doses (30, 100, 200, 300 or 500 mg/kg) without modifying spontaneous locomotor activity. At the highest doses (300 and 500 mg/kg), Aya also showed selectivity to both acute and sensitized Eth responses. Finally, a counter-sensitization strategy with 100 or 300 mg/kg of Aya for 8 consecutive days after the establishment of Eth-induced behavioral sensitization was effective in blocking its subsequent expression on an Eth challenge. CONCLUSIONS: We demonstrated that Aya not only inhibits early behaviors associated with the initiation and development of Eth addiction, but also showed effectiveness in reversing long-term drug effects expression, inhibiting the reinstatement of Eth-induced behavioral sensitization when administered in the Eth-associated environment.

Evaluation of zimeldine in Alzheimer's disease. Cognitive and biochemical measures.

Neuropsychological and neurochemical effects of zimeldine, a relatively specific serotonin reuptake blocker, were examined in four patients with clinically diagnosed Alzheimer's disease, in a double-blind, placebo-controlled, crossover study. Individualized doses of zimeldine were administered to achieve target plasma zimeldine concentrations of approximately 50 (low) to 100 (high) ng/mL. Overall, there was no significant effect of zimeldine on memory or reaction time measures as compared with placebo. The drug significantly reduced (by up to 38%) 5-hydroxyindoleacetic acid concentrations in the cereobrospinal fluid and almost abolished (90% reduction) platelet serotonin uptake. Cerebrospinal fluid concentrations of 3-methoxy-4-hydroxy-phenylglycol, a major metabolite of norepinephrine, and homovanillic acid, the major metabolite of dopamine, were not altered. Our findings indicate that alterations in central and peripheral serotoninergic function by a serotonin reuptake blocker (zimeldine) are unaccompanied by measurable changes in memory and/or reaction time in patients presumed to have Alzheimer's disease.

Prevalence of HIV-1 and HIV-2/HTLV-IV infections in Luanda and Cabinda, Angola.

A seroepidemiological study of human immune deficiency virus type 1 (HIV-1) and HIV-2/human T-lymphotropic virus type IV (HIV-2/HTLV-IV) infections was performed in Angola in October 1986. Until then five cases of acquired immune deficiency syndrome (AIDS) had been registered in Angola. During this study, another three cases with clinical AIDS were found and confirmed by HIV-1 serology. A total of 1,215 sera from groups of healthy persons and patients were tested for HIV-1 and HIV-2/HTLV-IV antibodies by enzyme-linked immunosorbent assays (ELISA). Sera positive by ELISA were also tested by Western blot (WB) analysis. In Luanda, the capital, HIV-1 antibodies were demonstrated in 0.4% (2/452) of male blood donors, in 0.3% (1/357) of pregnant women, in 1% (1/100) of tuberculosis patients, in 4% (4/94) of patients at medical wards, and in none of 22 women hospitalized with pelvic infections. In the Cabinda province, 11% (4/38) of postnatal women at a maternity ward were found to be HIV-1 seropositive, but only 2% (1/55) of other hospitalized patients and none of 32 male blood donors or 59 healthy persons in a village on the border to Zaire. Specific antibodies to HIV-2/HTLV-IV were not found in any of the sera. However, 16 out of 17 HIV-1 positive sera cross-reacted with HIV-2/HTLV-IV core proteins by WB. In October 1987, 280 of the blood donors from Luanda were retested for HIV-1 antibodies and one of them was found to have seroconverted during the previous year.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the utility of air-dried whole mounts for quantitative electron microprobe studies of platelet dense bodies.

A variety of electronmicroscope techniques have been used to examine how the air-drying process may affect the dense bodies in whole mounts of platelets. (a) Selected-area-diffraction and electron microprobe studies suggest that the air-drying process can result in the formation of crystalline precipitates of sodium chloride on grid films and platelets. However, no crystals were detected in the calcium-and-phosphorus-containing matrix of dense bodies. (b) Tilting studies show that dense bodies in human platelets are spherical or ellipsoidal in shape. Dense bodies in rabbit platelets, in contrast, appear flattened in a horizontal plane. (c) Human-platelet dense bodies probed with a small (20 nm diameter) spot vary widely in their peak/background ratios for calcium and phosphorus-a finding that suggests that the two elements may not be evenly distributed throughout the dense-body matrix. Nevertheless, when dense bodies are probed with a larger (200 nm diameter) spot, they do not appear to differ appreciably among themselves in their calcium or phosphorus content. The data suggest that with human platelets, air drying may be a preparative procedure which permits comparison by microprobe techniques of dense-body matrix content in platelet populations.

Uptake of 6-fluoro-5-hydroxytryptamine and 4,6-difluoro-5-hydroxytryptamine into releasable and non-releasable compartments of human platelets.

1 The ring-fluorinated compounds, 6-fluoro-5-hydroxytryptamine and 4,6-difluoro-5-hydroxytryptamine, are sterically similar to 5-hydroxytryptamine (5-HT) but have pKaS for their 5-hydroxyl groups (9.7 and 8.0 respectively) which are lower than that of 5-HT. 2 The rates at which [3H]-5-HT, [3H]-6-fluoro-5-HT, and [3H]-4,6-difluoro-5-HT entered the releasable (vesicular) and non-releasable compartments of washed human platelets during a 1 min incubation period at 37 degrees C were similar. These portions of the uptake process therefore appears to be relatively independent of the pKa of the 5-hydroxyl group. 3 The [3H]-4,6-difluoro-5-HT was unique since material accumulated in the non-releasable compartment during uptake did not migrate into the vesicular compartment under appropriate incubation conditions. 4 The data suggest that the zwitterionic form of 5-HT is not the transported species, but that the electronic configuration about the 5-hydroxyl group may be critical for translocation from a non-releasable to a releasable compartment.

Evaluation of the uptake of various amines into storage vesicles of intact human platelets.

1 The uptake of various 3H-labelled amines into a thrombin-releasable compartment of human platelets, thought to represent the platelet vesicular storage pool, has been evaluated. Measurable amounts of 5-hydroxytryptamine (5-HT), dopamine, tyramine, octopamine, and tryptamine accumulate in this pool, and also in a non-thrombin-releasable (cytoplasmic) pool during a 30 min incubation period with 10(-5) M extracellular amine concentrations. 2 No differences in the accumulation of vesicular or cytoplasmic 5-HT, dopamine, and tyramine are found in platelets treated with deprenyl to inhibit platelet monoamine oxidase as compared to controls. 3 Extracellular tyramine or dopamine in concentrations as high as 10(-5) M does not alter the initial rate of 5-HT uptake across the platelet plasma membrane. Similarly, sizable cytoplasmic pools of either amine do not alter the initial rate at which small amounts of 5-HT enter platelet cytoplasm or storage vesicles. 5-HT thus appears to be the preferred substrate for uptake into platelets and for movement from cytoplasm to vesicles.