154 research outputs found
Hepato-protective, antioxidant activities and acute toxicity of a stem bark extract of Erythrina senegalensis DC.
This study aimed at evaluating the in vitro antioxidant and hepatoprotective activities of different stem bark extracts of Erythrina senegalensis prepared with ethanol, and the in vivo hepatoprotective activity and acute toxicity of the best extract. The 2, 4-diphenyl-1-picryl-hydrazil (DPPH) and microsomal lipid peroxidation (MLP) models, and the rat liver slices system were respectively used for the in vitro study. The Methylene chloride/methanol (1:1 v/v) (Emc) and 40% ethanolic (E40) extracts were more efficient in inhibiting MLP and in scavenging DPPH radical. However, E40 was most effective with regards to lactate dehydrogenase (LDH) leakage inhibition from rat liver slices intoxicated with carbon tetrachloride (CCl4). The in vivo hepatoprotective activity was evaluated against CCl4-induced hepatotoxicity in rats. The E40 extract (100 mg/Kg) significantly reduced the increase in ALT, AST and lipid peroxidation in liver homogenate, showing that the extract is as protective as silymarin at the same dose. Acute toxicity was evaluated in mice and E40 did not produce any behavioural changes or mortality even at an oral dose of 16 g/kg. The extract was found to contain antioxidant classes of compounds (flavonoids and polyphenols). In conclusion, the E40 extract of E. senegalensis could be an important source of hepatoprotective compounds.Key words: Erythrina senegalensis, stem bark extract, antioxidant, hepatoprotective, carbon tetrachloride
Activities of selected medicinal plants against multi-drug resistant Gram-negative bacteria in Cameroon
Background: Medicinal plants are used worldwide for several human ailments including bacterial infections. The present work was designed to assess the in vitro antibacterial activities of some Cameroonian medicinal plants including Entada abyssinica, Entada africana, Pentaclethra macrophylla, Allexis cauliflora, Anthocleista leibrechtsiana, Carapa procera, Carica papaya and Persea americana against Gram-negative bacteria expressing multidrug resistant (MDR) phenotypes.Methods: The microbroth dilution was used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the samples against eight bacterial strains belonging to four species, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae and Providencia stuartii.Results: The extracts displayed selective antibacterial activities with the minimal inhibitory concentrations (MIC) values ranges of 64 to 1024 μg/mL. The most active extract was that from Pentaclethra macrophylla (TPM) that showed inhibitory activities against five of the eight (62.5%) tested bacteria. The lowest MIC value (64 μg/mL) was recorded with the crude extract of Entada africana against E. coli AG100A whilst the best MBC (256 μg/mL) value was also obtained with methanol extract of Persea americana against this bacterial strain.Conclusion: The results of the present work provide baseline information on the possible use of Pentaclethra macrophylla, Entada africana and Entada abyssinica in the treatment of selected bacterial infections.Keywords: Antibacterial activity; multi-drug resistant; medicinal plant
Using Performance Forecasting to Accelerate Elasticity
Cloud computing facilitates dynamic resource provisioning. The automation of resource management, known as elasticity, has been subject to much research. In this context, monitoring of a running service plays a crucial role, and adjustments are made when certain thresholds are crossed. On such occasions, it is common practice to simply add or remove resources. In this paper we investigate how we can predict the performance of a service to dynamically adjust allocated resources based on predictions. In other words, instead of “repairing” because a threshold has been crossed, we attempt to stay ahead and allocate an optimized amount of resources in advance. To do so, we need to have accurate predictive models that are based on workloads. We present our approach, based on the Universal Scalability Law, and discuss initial experiments
A dual thromboxane inhibitor and thromboxane receptor antagonist prevents pig myocardial infarction induced by coronary thrombosis
peer reviewe
Hepatoprotective and antioxidant activities of stem bark extract of Khaya grandifoliola (Welw) CDC and Entada africana Guill. et Perr
ABSTRACT Khaya grandifoliola (Meliaceae) and Entada africana (Fabaceae) are traditionally used as source of medicines against liver related diseases. But the most efficient solvent to extract the plants bioactive compounds has not yet been found. This work aimed at evaluating and comparing the hepatoprotective and antioxidant activities of Hexane (HE), methylenechloride-methanol (MCME) and water (WE) extracts of the plants stem bark. The hepatoprotective activity was evaluated by acetaminopheninduced damage in rat liver slices in measuring lactate dehydrogenase (LDH) leakage as toxicity marker. The antioxidant activity was assessed by using 2, 4-diphenyl-1-picryl-hydrazil (DPPH), β-carotene-linoleic acid system (β-CLAMS) and microsomal lipid peroxidation (MLP) assays. The MCME extract of both plants efficiently decreased LDH leakage from liver slices. At the tested concentration of 100µg/ml, the hepatoprotective percentage of the extract of K. grandifoliola (87.15%) and that of silymarine (93.73%) were comparable. In the antioxidant study, the MCME and WE extracts of both plants performed well in inhibiting MLP assay but, the MCME extracts were the more antioxidant with IC 50 values of 2.7±0.05µg/ml and 0.50±0.07µg/ml comparable with Trolox (2.27±0.52µg/ml) for K. grandifoliola and E. africana, respectively. Phytochemically, many classes of compounds including polyphenols were tested positive in the MCME extracts. From the interesting activity of these extracts, it might be concluded that methylenechloride-methanol (1:1v/v) mixture is the most efficient solvent to extract hepatoprotective and antioxidant active principles from K. grandifoliola and E. africana stem bark
Management of infants with brief resolved unexplained events (Brue) and apparent life-threatening events (alte): A rand/ucla appropriateness approach
Unexpected events of breath, tone, and skin color change in infants are a cause of consider-able distress to the caregiver and there is still debate on their appropriate management. The aim of this study is to survey the trend in prevention, decision-making, and management of brief resolved unexplained events (BRUE)/apparent life-threatening events (ALTE) and to develop a shared proto-col among hospitals and primary care pediatricians regarding hospital admission criteria, work-up and post-discharge monitoring of patients with BRUE/ALTE. For the study purpose, a panel of 54 experts was selected to achieve consensus using the RAND/UCLA appropriateness method. Twelve scenarios were developed: one addressed to primary prevention of ALTE and BRUE, and 11 focused on hospital management of BRUE and ALTE. For each scenario, participants were asked to rank each option from ‘1’ (extremely inappropriate) to ‘9’ (extremely appropriate). Results derived from panel meeting and discussion showed several points of agreement but also disagreement with different opinion emerged and the need of focused education on some areas. However, by combining previous recommendations with expert opinion, the application of the RAND/UCLA appropriateness permit-ted us to drive pediatricians to reasoned and informed decisions in term of evaluation, treatment and follow-up of infants with BRUE/ALTE, reducing inappropriate exams and hospitalisation and highlighting priorities for educational interventions
The 2009 edition of the GEISA spectroscopic database
The updated 2009 edition of the spectroscopic database GEISA (Gestionet Etudedes Informations Spectroscopiques Atmospheriques ; Management and Study of Atmospheric Spectroscopic Information) is described in this paper. GEISA is a computer-accessible system comprising three independent sub-databases devoted, respectively, to: line parameters, infrared and ultraviolet/visible absorption cross-sections, microphysical and optical properties of atmospheric aerosols. In this edition, 50 molecules are involved in the line parameters sub-database, including 111 isotopologues, for a total of 3,807,997 entries, in the spectral range from 10-6 to 35,877.031cm-1.
GEISA, continuously developed and maintained at LMD (Laboratoirede Meteorologie Dynamique, France) since 1976, is implemented on the IPSL/CNRS(France) ‘‘Ether’’ Products and Services Centre WEB site (http://ether.ipsl.jussieu.fr), where all archived spectroscopic data can be handled through general and user friendly associated managements of software facilities. More than 350 researchers are registered for online use of GEISA
The HITRAN2020 Molecular Spectroscopic Database
The HITRAN database is a compilation of molecular spectroscopic parameters. It was established in the early 1970s and is used by various computer codes to predict and simulate the transmission and emission of light in gaseous media (with an emphasis on terrestrial and planetary atmospheres). The HITRAN compilation is composed of five major components: the line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, experimental infrared absorption cross-sections (for molecules where it is not yet feasible for representation in a line-by-line form), collision-induced absorption data, aerosol indices of refraction, and general tables (including partition sums) that apply globally to the data. This paper describes the contents of the 2020 quadrennial edition of HITRAN. The HITRAN2020 edition takes advantage of recent experimental and theoretical data that were meticulously validated, in particular, against laboratory and atmospheric spectra. The new edition replaces the previous HITRAN edition of 2016 (including its updates during the intervening years).
All five components of HITRAN have undergone major updates. In particular, the extent of the updates in the HITRAN2020 edition range from updating a few lines of specific molecules to complete replacements of the lists, and also the introduction of additional isotopologues and new (to HITRAN) molecules: SO, CH3F, GeH4, CS2, CH3I and NF3. Many new vibrational bands were added, extending the spectral coverage and completeness of the line lists. Also, the accuracy of the parameters for major atmospheric absorbers has been increased substantially, often featuring sub-percent uncertainties. Broadening parameters associated with the ambient pressure of water vapor were introduced to HITRAN for the first time and are now available for several molecules.
The HITRAN2020 edition continues to take advantage of the relational structure and efficient interface available at www.hitran.org and the HITRAN Application Programming Interface (HAPI). The functionality of both tools has been extended for the new edition
The HITRAN2020 molecular spectroscopic database
The HITRAN database is a compilation of molecular spectroscopic parameters. It was established in the early 1970s and is used by various computer codes to predict and simulate the transmission and emission of light in gaseous media (with an emphasis on terrestrial and planetary atmospheres). The HITRAN compilation is composed of five major components: the line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, experimental infrared absorption cross-sections (for molecules where it is not yet feasible for representation in a line-by-line form), collision-induced absorption data, aerosol indices of refraction, and general tables (including partition sums) that apply globally to the data. This paper describes the contents of the 2020 quadrennial edition of HITRAN. The HITRAN2020 edition takes advantage of recent experimental and theoretical data that were meticulously validated, in particular, against laboratory and atmospheric spectra. The new edition replaces the previous HITRAN edition of 2016 (including its updates during the intervening years). All five components of HITRAN have undergone major updates. In particular, the extent of the updates in the HITRAN2020 edition range from updating a few lines of specific molecules to complete replacements of the lists, and also the introduction of additional isotopologues and new (to HITRAN) molecules: SO, CH3F, GeH4, CS2, CH3I and NF3. Many new vibrational bands were added, extending the spectral coverage and completeness of the line lists. Also, the accuracy of the parameters for major atmospheric absorbers has been increased substantially, often featuring sub-percent uncertainties. Broadening parameters associated with the ambient pressure of water vapor were introduced to HITRAN for the first time and are now available for several molecules. The HITRAN2020 edition continues to take advantage of the relational structure and efficient interface available at www.hitran.org and the HITRAN Application Programming Interface (HAPI). The functionality of both tools has been extended for the new edition
An equivalent posture to squatting is seen in an unoperated adult with tetralogy of Fallot.
Sir,
The advances in paediatric cardiology and cardiac
surgery have led to earlier and earlier surgical repair
of congenital cardiac malformations. In consequence,
the clinical picture of many congenital
cardiac malformations has changed, and some
signs and symptoms are no longer observed in their
typical appearance. Sometimes, however, it is
possible to recognise the transformation of an old
symptom or sign into a new one, with a new clinical
appearance, as we have recenrly observed in an adult
patient with retralogy of Fal1ot.
The old sign is squarring, which is the
characteristic instinctive knees-to-chest-posirion
assumed after exertion by patients with certain
rypes of cyanotic congenital cardiac malformations,
notably tetralogy of Fallot. Squatring was initially
brought to prominence by Taussig,' and generally
appears at about one year of age, or when the child
starts waiking. Investigarions have shown that the
saturations of oxygen, diminished by exercise, can
return to the levels prior ro exercise more rapidly
when the subject adopts a squarring rather than
a standing position.''' This beneficial effect of
squatting is probably due to two phenomenons.
The first is the exclusion from the circulation of the
highly unsaturated blood from the legs, due to the
compression of the femoral vessels. The second is
the reduction in the degree of right-to-left shunting
due to the increase ofperipheral vascular resisrance,
which opposes the right-to-left shunt through the
ventricular septal defect, and increases the flow of
blood to the 1ungs. During hypoxic spells, an infant
Correspondence to: Dr. Nicola Carano, Department of Pediatrics, Pediarric
Cardiology Unit, University of Parma, Via Gramsci 14, 43lOO parma, Italy.
Tel : * 390) 2 1 7021 42; Fax: + 190121,1 02394t E-mail: [email protected]
incapable of standing also tries to obtain the same
physiological effects of squatting, compressing his
abdomen against the shoulder of his caregiver.
1ù7hat happens in adults? \We have recently
observed a 40 year-old man with tetralogy of Fallot,
who had always refirsed surgicai rreatmenr. His
clinical condition progressively worsened during his
life, with increasing cyanosis, dyspnoea on exertion,
and severe limitation in his physical activity. This man
previously loved working in the countryside, and
would not abandon this hobby even if it caused him
severe fatigue and cyanosis. §7hen he was exhausted,
he would return home on his tractor, and press his
abdomen against the top of a small refrigeraror that
was in the garage, assuming a position with his legs
on one side of the refrigerator and his head on rhe
other. This position permitted him more rapidly to
return to his usual srate more rapidly. This clinical
observation indicates that adults with retralogy of
Fallot use manoeuvres that are equivalent to squarring
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