1,534 research outputs found
Composition of Non Volatile Oils and Antimicrobial Activities of Extracts from Monanthotaxis Discolor, and an Undescribed Uvariondedron Species
The chemical compositions of non volatile oil extracts from two Annoneceous plant species Monanthotaxis discolor and an undescribed Uvariodendron species which are endemic to Eastern Arc Mountains, Tanzania were determined by GC-MS. The biological activities of extracts and fractionated samples were also determined. Both methanol and dichloromethane extracts of the root bark of M. discolor showed mild antimicrobial activity and had positive brine shrimp test (BST). The BST test for dichloromethane extract of M. discolor root bark were LC50 41.794 μg/ml and that of methanol extract showed LC50 13.560 μg/ml. The petroleum ether and dichloromethane extracts of root bark of Uvariodendron species showed cytotoxicity of LC50 33.06 μg/ml and LC50 35.35 μg/ml, respectively. Twelve major constituents were identified from the dichloromethane extract of M. discolor root bark of which the following compounds were in high composition; α- cadinol (42.85%), (-)-alloaromadendrene (11.7%) aristolone (10.57 %), γ-cadinene (8.72%), δ- cadinene (3.44%) and cubenene (2.28%). The Second fraction of the third repeated column chromatography from the VLC fraction of dichloromethane extract and the first fraction of the VLC of methanol extract root bark revealed, among others 23 components of which the most abundant were; (-)-alloaromadendrene (15.1%), T-cadinol (8.08%), chamigren (5.3%) and γ- Cadinene (5.1%). Other components were also identified from other methanol fractions; (+)- aromadendrene, (18.2%), (-)-alloaromadendrene (12.8%), 4,9-muurodiene (5.3%), T-cadinol (83%), ς-himachelene (0.63%) and ledol (0.3%). The ethanol:dichloromethane (1:1) extract of the leaves of M. discolor showed four different components from those identified from root bark extracts among which heptacosane and tributylamine had percentage composition of (3.42%) and (0.34%),.respectively. The petroleum ether extract of the root bark of the undescribed Uvariodendron species revealed seven components of which the most abundant were methyl eugenol (38.7%) and elemicin (18.2%). For the ethanol extract of stem bark oil mixtures the most abundant components were δ-cadinol (0.25%), methyl eugenol (0.12%), isoelemecene (0.04%), and diisooctyphthalate (0.02%).Keywords: Annoneceous, Monanthotaxis discolor, undescribed Uvariodendron species, Antimicrobial, cytotoxicity, α-cadinol, (-)-alloaromadendrene, T-cadinol, methyl eugenol, elemicin, aromadendrene
Chemical constitutents and cytotoxicity of some Tanzanian wild mushrooms
The sterol ergosterol and ergosta-4,22-diene-3β,7α-diol, together with 4-hydroxybenzaldehyde were isolated from the mushroom species Polyporus molluscensis, Cantharellus isabelinus, C. symoensii and a Podaxis species. Their structures were established on the basis of spectroscopic data. The ethanol extracts of mushroom samples of Agaricus sp. and Termitomyces letestui also showed cytotoxicity against the brine shrimp larvae. Tanzania Journal of Science Vol. 31 (2) 2005: pp. 1-
Frequency and Pattern of Gynecological Cancers in Federal Teaching Hospital, Abakaliki, Nigeria
Background: Gynecological cancers are common and are among the leading causes of cancer‑related deaths worldwide. Aim: The objective of this study was to determine the pattern and relative frequencies of gynecological cancers as seen at the Federal Teaching Hospital, Abakaliki, Nigeria. Materials and Methods: A 2‑year retrospective study of female genital tract malignancies was conducted at the Federal Teaching Hospital, Abakaliki. The case notes of patients admitted for female genital tract malignancy between January 1, 2012 and December 31, 2013 were retrieved from the ward admissions and discharge books and the operating theater record books. The data were analyzed using Statistical Package for Social Science (SPSS), IBM SPSS statistics Version 20, IBM incorporation and licensors 1989,2011 New York USA and the results expressed in descriptive statistics by simple percentages. Result: A total of 1,178 women were seen during the study period, while 99 were found to have gynecological malignancy. The proportion of gynecological malignancies was 8.4%. Majority of the patients were in the 5th and 6th decades of life, most (60.6%) had cervical cancer, followed by ovarian cancer (19.2%), endometrial cancer (10.1%) vulva cancer (7.1%), and the least was choriocarcinoma (3.0%). Tumors of fallopian tube and vagina were not seen during the study period. Majority of the patients presented late and the common presentation was vaginal bleeding. Conclusion: Despite the preventable nature of cancer of cervix, it remained the most common female genital tract malignancy in Abakaliki, southeast Nigeria. Education and public enlightenment on the importance of routine screening and treatment of premalignant lesions of the cervix are necessary tools to reduce the incidence and mortality of cervical cancer.KEY WORDS: Abakaliki, cancer, frequency, gynecologic, gynecological cancer, Nigeria, patter
A case of septicaemic anthrax in an intravenous drug user
<p><b>Background:</b> In 2000, Ringertz et al described the first case of systemic anthrax caused by injecting heroin contaminated with anthrax. In 2008, there were 574 drug related deaths in Scotland, of which 336 were associated with heroin and or morphine. We report a rare case of septicaemic anthrax caused by injecting heroin contaminated with anthrax in Scotland.</p>
<p><b>Case Presentation:</b> A 32 year old intravenous drug user (IVDU), presented with a 12 hour history of increasing purulent discharge from a chronic sinus in his left groin. He had a tachycardia, pyrexia, leukocytosis and an elevated C-reactive protein (CRP). He was treated with Vancomycin, Clindamycin, Ciprofloxacin, Gentamicin and Metronidazole. Blood cultures grew Bacillus anthracis within 24 hours of presentation. He had a computed tomography (CT) scan and magnetic resonance imagining (MRI) of his abdomen, pelvis and thighs performed. These showed inflammatory change relating to the iliopsoas and an area of necrosis in the adductor magnus.</p>
<p>He underwent an exploration of his left thigh. This revealed chronically indurated subcutaneous tissues with no evidence of a collection or necrotic muscle. Treatment with Vancomycin, Ciprofloxacin and Clindamycin continued for 14 days. Negative Pressure Wound Therapy (NPWT) device was applied utilising the Venturi™ wound sealing kit. Following 4 weeks of treatment, the wound dimensions had reduced by 77%.</p>
<p><b>Conclusions:</b> Although systemic anthrax infection is rare, it should be considered when faced with severe cutaneous infection in IVDU patients. This case shows that patients with significant bacteraemia may present with no signs of haemodynamic compromise. Prompt recognition and treatment with high dose IV antimicrobial therapy increases the likelihood of survival. The use of simple wound therapy adjuncts such as NPWT can give excellent wound healing results.</p>
“Piggy-Backing” on Diagnostic Platforms Brings Hope to Neglected Diseases: The Case of Sleeping Sickness
Dynamics of DNA replication loops reveal temporal control of lagging-strand synthesis
In all organisms, the protein machinery responsible for the replication of DNA, the replisome, is faced with a directionality problem. The antiparallel nature of duplex DNA permits the leading-strand polymerase to advance in a continuous fashion, but forces the lagging-strand polymerase to synthesize in the opposite direction. By extending RNA primers, the lagging-strand polymerase restarts at short intervals and produces Okazaki fragments. At least in prokaryotic systems, this directionality problem is solved by the formation of a loop in the lagging strand of the replication fork to reorient the lagging-strand DNA polymerase so that it advances in parallel with the leading-strand polymerase. The replication loop grows and shrinks during each cycle of Okazaki fragment synthesis. Here we use single-molecule techniques to visualize, in real time, the formation and release of replication loops by individual replisomes of bacteriophage T7 supporting coordinated DNA replication. Analysis of the distributions of loop sizes and lag times between loops reveals that initiation of primer synthesis and the completion of an Okazaki fragment each serve as a trigger for loop release. The presence of two triggers may represent a fail-safe mechanism ensuring the timely reset of the replisome after the synthesis of every Okazaki fragment.
CD98hc facilitates B cell proliferation and adaptive humoral immunity.
The proliferation of antigen-specific lymphocytes and resulting clonal expansion are essential for adaptive immunity. We report here that B cell-specific deletion of the heavy chain of CD98 (CD98hc) resulted in lower antibody responses due to total suppression of B cell proliferation and subsequent plasma cell formation. Deletion of CD98hc did not impair early B cell activation but did inhibit later activation of the mitogen-activated protein kinase Erk1/2 and downregulation of the cell cycle inhibitor p27. Reconstitution of CD98hc-deficient B cells with CD98hc mutants showed that the integrin-binding domain of CD98hc was required for B cell proliferation but that the amino acid-transport function of CD98hc was dispensable for this. Thus, CD98hc supports integrin-dependent rapid proliferation of B cells. We propose that the advantage of adaptive immunity favored the appearance of CD98hc in vertebrates
Incidence of community-acquired lower respiratory tract infections and pneumonia among older adults in the United Kingdom: a population-based study.
Community-acquired lower respiratory tract infections (LRTI) and pneumonia (CAP) are common causes of morbidity and mortality among those aged ≥65 years; a growing population in many countries. Detailed incidence estimates for these infections among older adults in the United Kingdom (UK) are lacking. We used electronic general practice records from the Clinical Practice Research Data link, linked to Hospital Episode Statistics inpatient data, to estimate incidence of community-acquired LRTI and CAP among UK older adults between April 1997-March 2011, by age, sex, region and deprivation quintile. Levels of antibiotic prescribing were also assessed. LRTI incidence increased with fluctuations over time, was higher in men than women aged ≥70 and increased with age from 92.21 episodes/1000 person-years (65-69 years) to 187.91/1000 (85-89 years). CAP incidence increased more markedly with age, from 2.81 to 21.81 episodes/1000 person-years respectively, and was higher among men. For both infection groups, increases over time were attenuated after age-standardisation, indicating that these rises were largely due to population aging. Rates among those in the most deprived quintile were around 70% higher than the least deprived and were generally higher in the North of England. GP antibiotic prescribing rates were high for LRTI but lower for CAP (mostly due to immediate hospitalisation). This is the first study to provide long-term detailed incidence estimates of community-acquired LRTI and CAP in UK older individuals, taking person-time at risk into account. The summary incidence commonly presented for the ≥65 age group considerably underestimates LRTI/CAP rates, particularly among older individuals within this group. Our methodology and findings are likely to be highly relevant to health planners and researchers in other countries with aging populations
Performance of the 2007 WHO Algorithm to diagnose Smear-negative Pulmonary Tuberculosis in a HIV prevalent setting
The 2007 WHO algorithm for diagnosis of smear-negative pulmonary tuberculosis (PTB) including Mycobacterium tuberculosis (MTB) culture was evaluated in a HIV prevalent area of Kenya
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Pressure shielding mechanism of canopies for trailing edge noise reduction in aerofoils
Session: Airframe / High-Lift Noise IView Video Presentation: https://doi.org/10.2514/6.2023-3204.vidThe pressure shielding mechanism of bio-inspired surface treatment, called canopies, has been investigated experimentally and applied to reduce trailing edge noise generated by aero- foils. Surface pressure experiments beneath the boundary layer on a flat and aerofoil section show that canopies can attenuate surface pressure in two frequency ranges, ∆ f 1 = 0.1 to 1.0 kHz and ∆f2 = 2 to 12 kHz, at some critical canopies’ height from the wall. Canopies with an Open-Area-Ratio (OAR or σ) of 50 % placed closer (h/δ=0.08) to the surface tend to in- crease attenuation with frequency, without any low-frequency peak attenuation. This high- frequency attenuation is mainly due to the mechanism of dissipation, of small-scale structures in the boundary-layer, provided by the canopies, which have relatively higher wall shear stress compared to flat plate or thicker canopy designs. As h/δ increases, the low-frequency atten- uation in the surface pressure becomes noticeable, with a peak value of 5 dB for a critical height of h/δ∗ ∼ 1, indicating the mechanism of blockage or shielding of large structures in the boundary-layer is responsible for the low-frequency attenuation. For h/δ ≥ 0.16, both the low- and high-frequency attenuation reduces and becomes almost zero for h/δ = 0.5. Furthermore, the mechanism of pressure shielding provided by the canopy treatment is shown to be a local phenomenon, for 70% <OAR < 90 % and very sensitive to the location of the canopy itself. The maximum attenuation in surface pressure is seen for the canopy geometries with small rod diameters with less spacing. The optimum canopy geometry, based on the surface pres- sure studies, was applied near the trailing edge of the NACA0012 aerofoil. The far-field noise study demonstrates, for the first time, that canopies can reduce broadband noise levels up to 12-14 dB in the frequency range between 2 and 12 kHz, provided they are scaled appropriately based on the incoming turbulent boundary-layer flow.EPSRC under grant No. EP/V038273/1
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