| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Abbas, Aamer, 1973, et al.
(författare)
-
Chemical images of marine bio-active compounds by surface enhanced Raman spectroscopy and transposed orthogonal partial least squares (T-OPLS)
- 2012
-
Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670 .- 1873-4324. ; 737, s. 37-44
-
Tidskriftsartikel (refereegranskat)abstract
- Surface enhanced Raman spectroscopy combined with transposed Orthogonal Partial Least Squares (T-OPLS) was shown to produce chemical images of the natural antibacterial surface-active compound 1,1,3,3-tetrabromo-2-heptanone (TBH) on Bonnemaisonia hamifera. The use of gold colloids function-alised with the internal standard 4-mercapto-benzonitrile (MBN) made it possible to create images of the relative concentration of TBH over the surfaces. A gradient of TBH could be mapped over and in the close vicinity of the B. hamifera algal vesicles at the attomol/pixel level. T-OPLS produced a measure of the spectral correlation for each pixel of the hyperspectral images whilst not including spectral variation that was linearly independent of the target spectrum. In this paper we show the possibility to retrieve specific spectral information with a low magnitude in a complex matrix.
|
|
| 5. |
- Abdel-Shafi, Seham, et al.
(författare)
-
The Association between icaA and icaB Genes, Antibiotic Resistance and Biofilm Formation in Clinical Isolates of Staphylococci spp.
- 2022
-
Ingår i: Antibiotics. - : MDPI. - 2079-6382. ; 11:3
-
Tidskriftsartikel (refereegranskat)abstract
- Sixty-six (66) Staphylococcus bacterial isolates were withdrawn from separate clinical samples of hospitalized patients with various clinical infections. Conventional bacteriological tests identified the species of all isolates, and standard microbiological techniques differentiated them into CoPS or CoNS. Their biofilm development was followed by an analysis via the MTP (microtiter tissue culture plates) technique, and we then investigated the presence/absence of icaA and icaB, which were qualified in the top-30 potent biofilm-forming isolates. Thirteen isolates (46.7%) showed the presence of one gene, six (20%) isolates exhibited the two genes, while ten (33.3%) had neither of them. The formation of staphylococci biofilms in the absence of ica genes may be related to the presence of other biofilm formation ica-independent mechanisms. CoPS was the most abundant species among the total population. S. aureus was the sole representative of CoPS, while S. epidermidis was the most abundant form of CoNS. Antibiotic resistance was developing against the most frequently used antimicrobial drugs, while vancomycin was the least-resisted drug. The totality of the strong and medium-strength film-forming isolates represented the majority proportion (80%) of the total investigated clinical samples. The biochemical pattern CoPS is associated with antibiotic resistance and biofilm formation and can be an alarming indicator of potential antibiotic resistance.
|
|
| 6. |
- Abdul-Hussein, Saba
(författare)
-
Cellular studies of neuromuscular disorders related to the sarcomeric proteins
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sarcomere is the basic unit of cardiac and skeletal muscle contraction and its proper function requires an invariant organization of this structure. Mutations in sarcomeric proteins are known to cause increasing number of different cardiac and skeletal muscle diseases. The front line in research on muscle diseases is at present to define the genetic background and pathogenesis of these diseases. The potential for development of effective therapies depends on elucidation of the molecular and cellular impact of the mutations on morphological abnormalities and muscle weakness that accompany pathogenesis. In paper I we identified an unexpected skeletal muscle myopathy in an infant with fatal cardiomyopathy due to a homozygous mutation in MyBPC3. The ectopic expression of cardiac MyBPC was restricted to abnormal type 1 muscle fibres, indicating that the muscle pathology was caused by a dominate-negative effect of mutant MyBPC3. In paper II we addressed the expression profile of a panel of sarcomeric components during myogenesis, with a focus on proteins associated with a group of congenital disorders. The analyses were performed in cultured human skeletal muscle myoblasts and myotubes. We identified early expression of certain isoforms involved in congenital diseases, suggesting the possibility of an early role for these proteins as constituent of the developing contractile apparatus during myofibrillogenesis. In paper III we used human tissue-culture cells as a model to investigate the primary trigger for β-tropomyosin-related myopathies and the basis for the histological changes seen in muscle biopsies of patients. Protein localization and pathobiology caused by dominant TPM2 mutations were investigated by transfecting human myoblasts and C2C12 with WT and mutant EGFP-fusion β-TM constructs. Abnormal aggregation of β-TM variants and their localization within the thin filaments was observed in myoblasts and differentiated myotubes. We demonstrated that histopathological phenotypes associated with β-TM mutants might be accounted for the variable response to the cellular environment influenced by physiological context, in combination with the time course of expression of mutant protein rather than the alteration of amino acid itself. Our results confirmed that cell cultures of human skeletal muscle are an appropriate tool and environment closer to the reality in human skeletal muscle and more reliably mimic the disease conditions. In paper IV we identified and characterized a new human protein aggregate myopathy and cardiomyopathy associated with combined mutations in isogenes TRIM63 and TRIM54, encoding muscle specific ring finger proteins, MuRF1 and MuRF3, respectively. Our morphological and cellular investigation suggested that the disease is caused through impaired organization of the microtubule network and sarcomeric M-band proteins. The results from this study have deepened the understanding of pathogenesis of a group of sarcomeric
|
|
| 7. |
- Abdul-Hussein, Saba, et al.
(författare)
-
Expression profiles of muscle disease-associated genes and their isoforms during differentiation of cultured human skeletal muscle cells
- 2012
-
Ingår i: BMC Musculoskeletal Disorders. - : BioMed Central. - 1471-2474. ; 13
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The formation of contractile myofibrils requires the stepwise onset of expression of muscle specific proteins. It is likely that elucidation of the expression patterns of muscle-specific sarcomeric proteins is important to understand muscle disorders originating from defects in contractile sarcomeric proteins.METHODS: We investigated the expression profile of a panel of sarcomeric components with a focus on proteins associated with a group of congenital disorders. The analyses were performed in cultured human skeletal muscle cells during myoblast proliferation and myotube development.RESULTS: Our culture technique resulted in the development of striated myotubes and the expression of adult isoforms of the sarcomeric proteins, such as fast TnI, fast TnT, adult fast and slow MyHC isoforms and predominantly skeletal muscle rather than cardiac actin. Many proteins involved in muscle diseases, such as beta tropomyosin, slow TnI, slow MyBPC and cardiac TnI were readily detected in the initial stages of muscle cell differentiation, suggesting the possibility of an early role for these proteins as constituent of the developing contractile apparatus during myofibrillogenesis. This suggests that in disease conditions the mechanisms of pathogenesis for each of the mutated sarcomeric proteins might be reflected by altered expression patterns, and disturbed assembly of cytoskeletal, myofibrillar structures and muscle development.CONCLUSIONS: In conclusion, we here confirm that cell cultures of human skeletal muscle are an appropriate tool to study developmental stages of myofibrillogenesis. The expression of several disease-associated proteins indicates that they might be a useful model system for studying the pathogenesis of muscle diseases caused by defects in specific sarcomeric constituents.
|
|
| 8. |
- Abdulrazaq, Muhammed, et al.
(författare)
-
Numerical modelling of the extensional dynamics in elastoviscoplastic fluids
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The extensional dynamics of an elasto-viscoplastic (EVP) fluid is studied by means of numerical simulations closely modelling an experimental configuration. Specifically, we track the interface between the EVP material and the Newtonian medium using an algebraic volume of fluid method (MTHINC-VOF) and employ a fully Eulerian immersed boundary method (IBM) to model the motion of the piston responsible of the extension of the material.We investigate the role of different values of the yield stress, surface tension at the interface between the EVP material and the surrounding fluid, polymer viscosity ratio, and extension rates on the necking thickness of the material, extensional viscosity, and yielding of the material. The results of the simulations reveal that when the yield stress of the EVP material is much larger than the viscous stresses, the material undergoes an elastic deformation, regardless of the selected values of extension rate, interfacial forces, and viscosity ratio. Moreover, increasing the ratio of the polymeric viscosity to the total viscosity of the system accelerates the EVP rupture due to the high stress concentration in the central part of the material sample. Specific and novel to our study, we show that interfacial forces cannot be ignored when the surface tension coefficient is such that a Capillary number based on the extensional rate is order 1. For large values of the surface tension coefficient, the EVP material fails sooner, with a clear deviation from the exponential reduction in the neck thickness.
|
|
| 9. |
- Abraha, Aynalem, et al.
(författare)
-
Perceptions of cancer patients and their caregivers regarding COVID-19 pandemic in Ethiopia
- 2021
-
Ingår i: J Clin Oncol 39, 2021 (suppl 15; abstr e24116).
-
Konferensbidrag (refereegranskat)abstract
- Background: Limited research is available about COVID 19 pandemic in Ethiopia in general and in relation to cancer care in particular. Ethiopia reported the first COVID-19 in March, 2020. The number of cases is increasing, putting much pressure on oncology care. This study examines what the Ethiopian cancer patients and their caregivers knew about COVID 19 after the initial stages of the pandemic. It also assesses the information needs, psychological experiences as well as the impact of pandemic on oncologist-patient-caregiver communication and treatment process. Methods: A cross-sectional study was conducted among 200 participants (100 cancer patients and 100 caregivers) at the initial stage of pandemic (May 1 - June 30, 2020) at Tikur Anbessa Specialized Hospital (TASH), Addis Ababa, Ethiopia. Data was collected using a pre-tested, structured questionnaire to assess knowledge and perceptions on COVID-19. Ethics approval was obtained from the Ethical Review Board of TASH (04/14/2015) and the Ethical Review Board of Western Sweden (DNR 520-18). Results: The results indicate that though both cancer patients and their caregivers show a high awareness of and knowledge about COVID 19, they need more information about the risks specific to cancer patients. The respondents are also concerned about the risks of pandemic outbreak in Ethiopia and its impact on availability of cancer care treatments in the country. The respondents report experiencing psychological concerns in relation to the pandemic. The higher educated patients and caregivers report being more concerned than the lower educated respondents. Delays in appointments and therapy are the main concerns in relation to cancer care. Further, both patients and caregivers experience that the restrictions on the number of caregivers present during interactions with oncologists negatively influence communication, resulting in relatives being excluded and patients experiencing loneliness and lack of support. Conclusions: Getting a better insight into knowledge and awareness of COVID-19 among cancer patients and their caregivers is essential for managing the effects of pandemic in cancer care. To our knowledge, there was no similar study in Ethiopia. The results of the study contribute to insights into patient and caregiver awareness of COVID 19, essential for adoption of health care protective practices, providing information and managing oncologist-patient-caregiver communication.
|
|
| 10. |
- Abraha, Atakelti, et al.
(författare)
-
Social determinants of under-5 child health : A qualitative study in Wolkayit Woreda, Tigray Region, Ethiopia
- 2019
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14:6
-
Tidskriftsartikel (refereegranskat)abstract
- Despite the significant reductions seen in under-5 child mortality in Ethiopia over the last two decades, more than 10,000 children still die each year in Tigray Region alone, of whom 75% die from preventable diseases. Using an equity lens, this study aimed to investigate the social determinants of child health in one particularly vulnerable district as a means of informing the health policy decision-making process. An exploratory qualitative study design was adopted, combining focus group discussions and qualitative interviews. Seven Focus Group Discussions with mothers of young children, and 21 qualitative interviews with health workers were conducted in Wolkayit district in May-June 2015. Data were subjected to thematic analysis. Mothers’ knowledge regarding the major causes of child mortality appeared to be good, and they also knew about and trusted the available child health interventions. However, utilization and practice of these interventions was limited by a range of issues, including cultural factors, financial shortages, limited female autonomy on financial resources, seasonal mobility, and inaccessible or unaffordable health services. Our findings pointed to the importance of a multi-sectoral strategy to improve child health equity and reduce under-5 mortality in Wolkayit. Recommendations include further decentralizing child health services to local-level Health Posts, and increasing the number of Health Facilities based on local topography and living conditions.
|
|
