Electrochemical degradation of the chloramphenicol at flow reactor

This paper reports a study of electrochemical degradation of the chloramphenicol antibiotic in aqueous medium using a flow-by reactor with DSA® anode. The process efficiency was monitored by chloramphenicol concentration analysis with liquid chromatography (HPLC) during the experiments. Analysis of Total Organic Carbon (TOC) was performed to estimate the degradation degree and Ion Chromatography (IC) was performed to determinate inorganic ions formed during the eletrochemical degradation process. In electrochemical flow-by reactor, 52% of chloramphenicol was degraded, with 12% TOC reduction. IC analysis showed the production of chloride ions (25 mg L-1), nitrate ions (6 mg L-1) and nitrite ions (4.5 mg L-1).Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Electrochemical degradation of the chloramphenicol at flow reactor

This paper reports a study of electrochemical degradation of the chloramphenicol antibiotic in aqueous medium using a flow-by reactor with DSA® anode. The process efficiency was monitored by chloramphenicol concentration analysis with liquid chromatography (HPLC) during the experiments. Analysis of Total Organic Carbon (TOC) was performed to estimate the degradation degree and Ion Chromatography (IC) was performed to determinate inorganic ions formed during the eletrochemical degradation process. In electrochemical flow-by reactor, 52% of chloramphenicol was degraded, with 12% TOC reduction. IC analysis showed the production of chloride ions (25 mg L-1), nitrate ions (6 mg L-1) and nitrite ions (4.5 mg L-1).33510881092Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Não te

H1N1pdm Influenza Infection in Hospitalized Cancer Patients: Clinical Evolution and Viral Analysis

BACKGROUND: The novel influenza A pandemic virus (H1N1pdm) caused considerable morbidity and mortality worldwide in 2009. The aim of the present study was to evaluate the clinical course, duration of viral shedding, H1N1pdm evolution and emergence of antiviral resistance in hospitalized cancer patients with severe H1N1pdm infections during the winter of 2009 in Brazil. METHODS: We performed a prospective single-center cohort study in a cancer center in Rio de Janeiro, Brazil. Hospitalized patients with cancer and a confirmed diagnosis of influenza A H1N1pdm were evaluated. The main outcome measures in this study were in-hospital mortality, duration of viral shedding, viral persistence and both functional and molecular analyses of H1N1pdm susceptibility to oseltamivir. RESULTS: A total of 44 hospitalized patients with suspected influenza-like illness were screened. A total of 24 had diagnosed H1N1pdm infections. The overall hospital mortality in our cohort was 21%. Thirteen (54%) patients required intensive care. The median age of the studied cohort was 14.5 years (3-69 years). Eighteen (75%) patients had received chemotherapy in the previous month, and 14 were neutropenic at the onset of influenza. A total of 10 patients were evaluated for their duration of viral shedding, and 5 (50%) displayed prolonged viral shedding (median 23, range=11-63 days); however, this was not associated with the emergence of a resistant H1N1pdm virus. Viral evolution was observed in sequentially collected samples. CONCLUSIONS: Prolonged influenza A H1N1pdm shedding was observed in cancer patients. However, oseltamivir resistance was not detected. Taken together, our data suggest that severely ill cancer patients may constitute a pandemic virus reservoir with major implications for viral propagation

Reduced Expression of the Vesicular Acetylcholine Transporter and Neurotransmitter Content Affects Synaptic Vesicle Distribution and Shape in Mouse Neuromuscular Junction

In vertebrates, nerve muscle communication is mediated by the release of the neurotransmitter acetylcholine packed inside synaptic vesicles by a specific vesicular acetylcholine transporter (VAChT). Here we used a mouse model (VAChT KDHOM) with 70% reduction in the expression of VAChT to investigate the morphological and functional consequences of a decreased acetylcholine uptake and release in neuromuscular synapses. Upon hypertonic stimulation, VAChT KDHOM mice presented a reduction in the amplitude and frequency of miniature endplate potentials, FM 1-43 staining intensity, total number of synaptic vesicles and altered distribution of vesicles within the synaptic terminal. In contrast, under electrical stimulation or no stimulation, VAChT KDHOM neuromuscular junctions did not differ from WT on total number of vesicles but showed altered distribution. Additionally, motor nerve terminals in VAChT KDHOM exhibited small and flattened synaptic vesicles similar to that observed in WT mice treated with vesamicol that blocks acetylcholine uptake. Based on these results, we propose that decreased VAChT levels affect synaptic vesicle biogenesis and distribution whereas a lower ACh content affects vesicles shape

Abordagem Prática Para o Ensino de Bioquímica

For the past 13 years, at the Federal University of Minas Gerais, practical classes during the Biochemistry course for Biology students have been based on small research projects developed by the students. At the beginning of the semester, each group of four to six students receives a different question which they are required to answer experimentally. One third of the 90 hour/semester course is dedicated to the development of the projects. Students must research the subjects and choose the best way to solve the problem experimentally. They write a proposal which is discussed and evaluated by the professors and, only after extensively discussing the proposals, the project is executed. Only minimal tutoring is offered, so that the solution of the problem is found by the students themselves. At the end of the semester, students write a report in the format of a scientific paper and present their results at a public poster session. This experience has been successful, as judged by its continuity of 13 years with different teams of professors, by the enthusiasm shown by the students and by the number of Biology students that decide to pursue undergraduate lab training and subsequently graduate work in our Department.</p

The construction process of pedagogical knowledge among nursing professors

Didactic knowledge about contents is constructed through an idiosyncratic synthesis between knowledge about the subject area, students' general pedagogical knowledge and the teacher's biography. This study aimed to understand the construction process and the sources of Pedagogical Content Knowledge, as well as to analyze its manifestations and variations in interactive teaching by teachers whom the students considered competent. Data collection involved teachers from an undergraduate nursing program in the South of Brazil, through non-participant observation and semistructured interviews. Data analysis was submitted to the constant comparison method. The results disclose the need for initial education to cover pedagogical aspects for nurses; to assume permanent education as fundamental in view of the complexity of contents and teaching; to use mentoring/monitoring and the value learning with experienced teachers with a view to the development of quality teaching

Reduced Vesicular Acetylcholine Transporter favors antidepressant behaviors and modulates serotonin and dopamine in female mouse brain.

Depression is extremely harmful to modern society. Despite its complex spectrum of symptoms, previous studies have mostly focused on the monaminergic system in search of pharmacological targets. However, other neurotransmitter systems have also been linked to the pathophysiology of depression. In this study, we provide evidence for a role of the cholinergic system in depressive-like behavior of female mice. We evaluated mice knockdown for the vesicular acetylcholine transporter (VAChT KD mice), which have been previously shown to exhibit reduced cholinergic transmission. Animals were subjected to the tail suspension and marble burying tests, classical paradigms to assess depressive-like behaviors and to screen for novel antidepressant drugs. In addition, brain levels of serotonin and dopamine were measured by high performance liquid chromatography. We found that female homozygous VAChT KD mice spent less time immobile during tail suspension and buried less marbles, indicating a less depressive phenotype. These differences in behavior were reverted by central, but not peripheral, acetylcholinesterase inhibition. Moreover, female homozygous VAChT KD mice exhibited higher levels of dopamine and serotonin in the striatum, and increased dopamine in the hippocampus. Our study thus shows a connection between depressive-like behaviors and the cholinergic system, and that the latter interacts with the monoaminergic system

VAChT KD^HOM NMJs have normal morphology but altered SVs distribution in the absence of stimulus.

<p>A and B– Representative images of nerve terminal profile from VAChT WT and VAChT KD^HOM mice in the absence of stimulation showed a altered SVs distribution from the active zone within the circles: 50 and 300 nm from the membrane, small and big circles respectively. Scale bar  = 500 nm. Magnification 50.000x. C– Graph showing the area of the presynaptic terminals in μm². D– Graph comparing the total postsynaptic membrane lenght (μm). E – Graph of the ratio SVs/area of presynaptic terminal in μm². F– Graph showing the average number of SVs located at different distances from the presynaptic active zones. G and H– Four serial sections of the profile of NMJs of VAChT WT (G1–G4) and VAChT KD^HOM (H1–H4) mice showing the altered SVs distribution in the active zone (* represent depletion areas of SVs) of motor terminals of VAChT KD^HOM in the absence of stimulus. Scale bar  = 500 nm. Magnification 50.000x. (n = 5 individual animals per genotype. * p<0.05).</p

The reduced expression of VAChT alters SVs distribution involved in eletrically stimulated NMJs.

<p>A and B – Representative images of two NMJs from diaphragm muscle of VAChT WT and VAChT KD^HOM mice after electrical stimulation (20 Hz for 5 minutes) showing an altered SVs distribution from the active zone within the circles: 50 and 300 nm from the membrane, small and big circles respectively. Scale bar  = 500 nm. Magnification 50.000x. C– Graph of the ratio SVs/area of presynaptic terminal in μm². D – Graph showing the average number of SVs located at different distances from the presynaptic active zones. E and F– Four serial sections of NMJs from VAChT WT (E1–E4) and VAChT KD^HOM (F1–F4) diaphragm showing the altered SVs distribution in the active zone (* represent areas depleted of SVs touching the membrane) of motor terminals of VAChT KD^HOM after electrical stimulation. Scale bar  = 500 nm. Magnification 50.000x. (n = 3 individual animals per genotype. * p<0.05, ** p = 0.005; *** p = 0.0006).</p