305 research outputs found

    Antibiotic resistance profile of staphylococci from clinical sources recovered from infants

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    Infants, children and the aged are among the groups most vulnerable to microbial infections more so when these microbial agents become resistant to antimicrobials. The antibiotic resistant profile of Staphylococcus aureus and selected coagulase negative staphylococci were determined by standard methods. Of the 178 staphylococcal isolates evaluated, 122 were S. aureus and the rest coagulase negative staphylococci. 68% of S. aureus isolates were resistant to amoxicillin, 69.8% to cloxacillin, 51% to augmentin and 71% to tetracycline. However, only 2.6% of the 116 S aureus isolates tested were resistant to gentamycin making the drug a reliable therapeutic agent in the event of failure of other antimicrobials in treating staphylococcal infections at least in this community. Resistance to the penicillin drugs was mediated by the elaboration of &#946-lactamase by both pathogenic and non-pathogenic staphylococci. The study shows a high rate of cloxacillin resistance and possibly the existence of methicillin resistance among these strains. 80% of the S aureus strains were multi-resistant with 25% of these resistant to three different antibiotics, 21% to 4 and 6.8% to 6 different drugs. Only 1.2% of these S aureus strains were resistant to 7 different antimicrobials underscoring the need to reduce the high incidence of multi-resistance in this community in the event of an epidemic caused by these strains. The study reveals prevalence of multi-resistance among both pathogenic and non-pathogenic staphylococci in the community.Key words: Staphylococci, Staphylococcus aureus, antibiotics, multi-resistance.African Journal of Biotechnology Vol. 4 (8), pp. 810-82

    Bacteriological Examination of Chronic Osteomyelitis cases in Ile-Ife, southwestern Nigeria.

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    The bacteriological examination of chronic osteomyelitis cases in lle-lfe, revealed Proteus mirabilisas the p'redominant isolate encountered (23.1 %). Staphylococci constituted 30.7% of the total bacterial isolates with Staphylococcus aureus accounting for only 1 0.2%. Other Gram-positive cocci cultured include, Staphylococcus spp (20.5%), coagulase negative staphylococci (CONS) (12.8%) and Streptococcus spp.{1.2%). Gram-negative rods constituted 55.1% of the total isolates with Pseudomonas aeruginosa being 8.5%, Eschericia coli 5.1% Citrobacter freundii, Salmonella spp 2.5% each. Antibiotic sensitivity test revealed all isolates to be multi-resistant to traditional antimicrobials, which is of epidemiologcal importance in treating cases of chronic osteomyelitis in this environment The studv suaaests institution of aoaressive theraoeutic interventions to avert oossible seaualae

    Assisted Self-Assembly to Target Heterometallic Mn-Nd and Mn-Sm SMMs: Synthesis and Magnetic Characterisation of [Mn7_{7}Ln3_{3}(O)4_{4}(OH)4_{4}(mdea)3_{3}(piv)9_{9}(NO3_{3})3_{3}] (Ln=Nd, Sm, Eu, Gd)**

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    Assisted self-assembly by using a preformed [Mn6_{6}O2_{2}(piv)10_{10}(4-Me-py)2_{2}(pivH)2_{2}] (1) (pivH=pivalic acid) cluster leads to 3 different outcomes of the reaction with Ln(NO3_{3})3_{3} ⋅ xH2_{2}O (Ln=Pr−Ho and Y): Mn7_{7}Ln3_{3} and in some cases the inverse butterfly Mn2_{2}Ln2_{2} for Ln=Pr−Eu, Mn5_{5}Ln4_{4} for Ln=Tb-Ho and in the special case of Gd all three possibilities can form. Whilst the magnetic properties for the Mn5_{5}Ln4_{4} systems show the expected known SMM properties, for Mn7_{7}Ln3_{3} two new examples of Nd- and Sm-containing SMMs have been discovered. in an assisted self-assembly approach starting from the [Mn6_{6}O2_{2}(piv)10_{10}(4-Me-py)2_{2}(pivH)2_{2}] cluster a family of Mn−Ln compounds (Ln=Pr−Yb) was synthesised. The reaction of [Mn6_{6}O2_{2}(piv)10_{10}(4-Me-py)2_{2}(pivH)2_{2}] (1) with N-methyldiethanolamine (mdeaH2_{2}) and Ln(NO3_{3})3_{3} ⋅ 6H2_{2}O in MeCN generally yields two main structure types: for Ln=Tb−Yb a previously reported Mn5_{5}Ln4_{4} motif is obtained, whereas for Ln=Pr−Eu a series of Mn7_{7}Ln3_{3} clusters is obtained. Within this series the GdIII^{III} analogue represents a special case because it shows both structural types as well as a third Mn2_{2}Ln2_{2} inverse butterfly motif. Variation in reaction conditions allows access to different structure types across the whole series. This prompts further studies into the reaction mechanism of this cluster assisted self-assembly approach. For the Mn7_{7}Ln3_{3} analogues reported here variable-temperature magnetic susceptibility measurements suggest that antiferromagnetic interactions between the spin carriers are dominant. Compounds incorporating Ln=NdIII^{III}(2), SmIII^{III}(3) and GdIII^{III} (5) display SMM behaviour. The slow relaxation of the magnetisation for these compounds was confirmed by ac measurements above 1.8 K

    Characterisation of Bacterial Isolates from Patients Wounds and Environmental Factors Predictive of Post-Surgical Infections at the Orthopaedic Ward in Ile-Ife, Nigeria

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    Objective: To determine the pattern of orthopaedic wound infection and the influence of environmental factors on the distribution of the etiologic bacterial agents. Design: A prospective observational study. Setting: Department of Orthopaedic Surgery and Traumatology, Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria. Subjects: Sixty patients with orthopaedic wound infections and orthopaedic ward environment. Results: Thirty- nine males (mean age 33.31+2SD) and 21 females ( mean age 27.47+2SD) with orthopaedic wounds. Three hundred and ten bacteria (190 from patients and 120 from ward environment) were isolated. The pattern of bacterial isolates from patients’ wounds was different from that of the airborne bacterial isolates irrespective of the length of stay on the ward. There was a significant difference in the distribution and resistance pattern of bacterial isolates from the patient’s wounds and ward environment. Conclusion: There is a high incidence of antibiotic resistance of bacterial isolates from samples cultured from patients compared with isolates from ward environment at this centre. The extensive use of pre-operative prophylactic and post-surgical antibiotics in various combinations at this centre needs to be re-examined to reduce the preponderance of antibiotic resistance

    Classical Analysis of Phenomenological Potentials for Metallic Clusters

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    The classical trajectories of single particle motion in a Wodds-Saxon and a modified Nilsson potential are studied for axial quadrupole deformation. Both cases give rise to chaotic behaviour when the deformation in the Woods-Saxon and the l**2 term in the modified Nilsson potential are turned on. Important similarities, in particular with regard to the shortest periodic orbits, have been found.Comment: 9 pages LaTex + 4 figures available via e-mail requests from the authors, to appear in Phys.Rev.Let

    On the possibility of magneto-structural correlations: detailed studies of di-nickel carboxylate complexes

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    A series of water-bridged dinickel complexes of the general formula [Ni<sub>2</sub>(μ<sub>2</sub>-OH<sub>2</sub>)(μ2- O<sub>2</sub>C<sup>t</sup>Bu)<sub>2</sub>(O<sub>2</sub>C<sup>t</sup>Bu)2(L)(L0)] (L = HO<sub>2</sub>C<sup>t</sup>Bu, L0 = HO<sub>2</sub>C<sup>t</sup>Bu (1), pyridine (2), 3-methylpyridine (4); L = L0 = pyridine (3), 3-methylpyridine (5)) has been synthesized and structurally characterized by X-ray crystallography. The magnetic properties have been probed by magnetometry and EPR spectroscopy, and detailed measurements show that the axial zero-field splitting, D, of the nickel(ii) ions is on the same order as the isotropic exchange interaction, J, between the nickel sites. The isotropic exchange interaction can be related to the angle between the nickel centers and the bridging water molecule, while the magnitude of D can be related to the coordination sphere at the nickel sites

    Environmental Costs of Government-Sponsored Agrarian Settlements in Brazilian Amazonia

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    Brazil has presided over the most comprehensive agrarian reform frontier colonization program on Earth, in which ~1.2 million settlers have been translocated by successive governments since the 1970's, mostly into forested hinterlands of Brazilian Amazonia. These settlements encompass 5.3% of this ~5 million km2 region, but have contributed with 13.5% of all land conversion into agropastoral land uses. The Brazilian Federal Agrarian Agency (INCRA) has repeatedly claimed that deforestation in these areas largely predates the sanctioned arrival of new settlers. Here, we quantify rates of natural vegetation conversion across 1911 agrarian settlements allocated to 568 Amazonian counties and compare fire incidence and deforestation rates before and after the official occupation of settlements by migrant farmers. The timing and spatial distribution of deforestation and fires in our analysis provides irrefutable chronological and spatially explicit evidence of agropastoral conversion both inside and immediately outside agrarian settlements over the last decade. Deforestation rates are strongly related to local human population density and road access to regional markets. Agrarian settlements consistently accelerated rates of deforestation and fires, compared to neighboring areas outside settlements, but within the same counties. Relocated smallholders allocated to forest areas undoubtedly operate as pivotal agents of deforestation, and most of the forest clearance occurs in the aftermath of government-induced migration

    Preclinical Efficacy of Cabazitaxel Loaded Poly (2-alkyl cyanoacrylate) Nanoparticle Variants

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    \ua9 2024 Valsalakumari et al. This work is published and licensed by Dove Medical Press Limited.Background: Biodegradable poly(alkyl cyanoacrylate) (PACA) nanoparticles (NPs) are receiving increasing attention in anti-cancer nanomedicine development not only for targeted cancer chemotherapy, but also for modulation of the tumor microenvironment. We previously reported promising results with cabazitaxel (CBZ) loaded poly(2-ethylbutyl cyanoacrylate) NPs (PEBCA-CBZ NPs) in a patient derived xenograft (PDX) model of triple-negative breast cancer, and this was associated with a decrease in M2 macrophages. The present study aims at comparing two endotoxin-free PACA NP variants (PEBCA and poly(2-ethylhexyl cyanoacrylate); PEHCA), loaded with CBZ and test whether conjugation with folate would improve their effect. Methods: Cytotoxicity assays and cellular uptake of NPs by flow cytometry were performed in different breast cancer cells. Biodistribution and efficacy studies were performed in PDX models of breast cancer. Tumor associated immune cells were analyzed by multiparametric flow cytometry. Results: In vitro studies showed similar NP-induced cytotoxicity patterns despite difference in early NP internalization. On intravenous injection, the liver cleared the majority of NPs. Efficacy studies in the HBCx39 PDX model demonstrated an enhanced effect of drug-loaded PEBCA variants compared with free drug and PEHCA NPs. Furthermore, the folate conjugated PEBCA variant did not show any enhanced effects compared with the unconjugated counterpart which might be due to unfavorable orientation of folate on the NPs. Finally, analyses of the immune cell populations in tumors revealed that treatment with drug loaded PEBCA variants affected the myeloid cells, especially macrophages, contributing to an inflammatory, immune activated tumor microenvironment. Conclusion: We report for the first time, comparative efficacy of PEBCA and PEHCA NP variants in triple negative breast cancer models and show that CBZ-loaded PEBCA NPs exhibit a combined effect on tumor cells and on the tumor associated myeloid compartment, which may boost the anti-tumor response
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