The Frequency of Otogenic Intracranial Complications in Chronic Suppurative Otitis Media with Cholesteatoma

Objectives:1. To determine the frequency of otogenic intracranial complications in chronic suppurative otitis media with cholesteatoma.2. To discuss the diagnosis and management of patients presenting with otogenic intracranial complications.Study Design: It was a prospective, descriptive and cross – sectional study using convenience sampling technique.Materials and Methods: This was a combined study conducted in the ENT Department of Postgraduate Medical Institute, Hayatabad Medical Complex, Peshawar and the ENT Department of Mardan Medical Complex, Mardan over a period of 3 years from January 1, 2007 to December 31, 2009. Cases presenting with chronic suppurative otitis media with cholesteatoma were studied and the frequency of otogenic intracranial complications occurring in these cases was calculated.Results: A total of 85 cases were studied. The ages of the patients ranged from 8 to 40 years. All the patients had chronic suppurative otitis media with cholesteatoma. The commonest complaint in cases with suspected intra-cranial complications was deep seated earache followed by persistent headache. Meningitis and extradural abscesses were the commonest intracranial complications. The frequency of intracranial complications in our study was found to be 11.76%.Conclusion: Otogenic intracranial complications due to cholesteatoma continue to pose a significant risk to the patients. High index of suspicion is essential for diagnosis and skilful management of otogenic intracranial comp-lications. Early recognition is possible and these cases should be managed in close collaboration with a neuro-surgeon

Current Trends in Acetins Production: Green versus Non-Green Synthesis

To utilize excess glycerol produced from the biodiesel industry, researchers are developing innovative methods of transforming glycerol into value-added chemicals. One strategy adopted is the conversion of glycerol into acetins, which are esters of glycerol that have wide applications in cosmetics, pharmaceuticals, food and fuel additives, and plasticizers and serve as precursors for other chemical compounds. Acetins are synthesized either by traditional chemical methods or by biological processes. Although the chemical methods are efficient, productive, and commercialized, they are “non-green”, meaning that they are unsafe for the environment and consumers. On the other hand, the biological process is “green” in the sense that it protects both the environment and consumers. It is, however, less productive and requires further effort to achieve commercialization. Thus, both methodologies have benefits and drawbacks, and this study aims to present and discuss these. In addition, we briefly discuss general strategies for optimizing biological processes that could apply to acetins production on an industrial scale

Effect of Zinc oxide Nanoparticles on Hyacinth's Fermentation

Abstract: In this study bio-hydrogen and bioethanol were produced from dry biomass of water hyacinth by microbial fermentation under influence of zinc oxide nanoparticles. For fermentative bio-hydrogen production biomass was first pretreated and then saccharified into fermentable sugars by enzymes. Sugars of enzymatic hydrolysis were xylose and glucose with concentration of 9.0% and 8.0% respectively. For bioethanol production dry plant was saccharified. The reducing sugar obtained in this method containing 5% glucose. The effect of zinc oxide nanoparticles on fermentative hydrogen and ethanol production from water hyacinth biomass was investigated in batch tests by mixed culture and yeast Saccharomyces cerevisiae respectively. Results showed that the specific concentration of zinc oxide nanoparticles decreased the hydrogen yield. Ethanol yield was enhanced by zinc oxide nanoparticles by using it in certain concentration range during fermentation. The maximum ethanol yield of 0.0193g/g of dry weight plant biomass was obtained at concentration of 5 mg/L of zinc oxide nanoparticles. The ethanol yield constitutes 75.68% of the maximum theoretical yield at zinc oxide nanoparticles

Metabolic engineering of Escherichia coli for production of mixed isoprenoid alcohols and their derivatives

Abstract Background Current petroleum-derived fuels such as gasoline (C5–C12) and diesel (C15–C22) are complex mixtures of hydrocarbons with different chain lengths and chemical structures. Isoprenoids are hydrocarbon-based compounds with different carbon chain lengths and diverse chemical structures, similar to petroleum. Thus, isoprenoid alcohols such as isopentenol (C5), geraniol (C10), and farnesol (C15) have been considered to be ideal biofuel candidates. NudB, a native phosphatase of Escherichia coli, is reported to dephosphorylate isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) into isopentenol. However, no attention has been paid to its promiscuous activity toward longer chain length (C10–C15) prenyl diphosphates. Results In this study, the promiscuous activity of NudB toward geranyl diphosphate (GPP) and farnesyl diphosphate (FPP) was applied for the production of isoprenoid alcohol mixtures, including isopentenol, geraniol, and farnesol, and their derivatives. E. coli was engineered to produce a mixture of C5 and C15 alcohols by overexpressing NudB (dihydroneopterin triphosphate diphosphohydrolase) and IspA (FPP synthase) along with a heterologous MVA pathway, which resulted in a total of up to 1652 mg/L mixture of C5 and C15 alcohols and their derivatives. The production was further increased to 2027 mg/L by overexpression of another endogenous phosphatase, AphA, in addition to NudB. Production of DMAPP- and FPP-derived alcohols and their derivatives was significantly increased with an increase in the gene dosage of idi, encoding IPP isomerase (IDI), indicating a potential modulation of the composition of the alcohols mixture according to the expression level of IDI. When IspA was replaced with its mutant IspA*, generating GPP in the production strain, a total of 1418 mg/L of the isoprenoid mixture was obtained containing C10 alcohols as a main component. Conclusions The promiscuous activity of NudB was newly identified and successfully used for production of isoprenoid-based alcohol mixtures, which are suitable as next-generation biofuels or commodity chemicals. This is the first successful report on high-titer production of an isoprenoid alcohol-based mixture. The engineering approaches can provide a valuable platform for production of other isoprenoid mixtures via a proportional modulation of IPP, DMAPP, GPP, and FPP syntheses

MOESM1 of Metabolic engineering of Escherichia coli for production of mixed isoprenoid alcohols and their derivatives

Additional file 1: Table S1. Primers, plasmids and bacterial strains used in this study. Table S2. Time course analysis of oxidation of farnesol to farnesal in E. coli DH5Îą-YjgB. Figure S1. GC-FID and GC-MS profile of standard isoprenoid-based alcohols and their derivatives. Figure S2. Comparison of cell growth of the strains NA-MBF2.0, NAK-MBF2.0, NA-MBF1.0, and NAK-MBF1.0. Figure S3. Comparison of cell growth of the strains NA-MBF1.1, NA-MBF1.2, NA-MBF1.1a and NA-MBF1.2a. Figure S4. Percent composition of isoprenoid mixtures obtained from the strains NA-MBF1.1, NA-MBF1.2, NA-MBF1.1a and NA-MBF1.2a. Figure S5. GC-FID standard curves of isoprenoid alcohols and their derivatives

MOESM2 of Metabolic engineering of Escherichia coli for production of mixed isoprenoid alcohols and their derivatives

Additional file 2: Table S3. Primers, plasmids and bacterial strains used in this study. Figure S6. GPP and FPP hydrolyzing assay of NudB