119 research outputs found

    Stem cell bioprocessing: The bioengineering of lung epithelium in 3D from embryonic stem cells

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    Stem cell therapies and tissue engineering strategies are required for the clinical treatment of respiratory diseases. Previous studies have established protocols for the differentiation of airway epithelium from stem cells but have involved costly and laborious culture methods. The aim of this thesis was to achieve efficient and reproducible maintenance and differentiation of embryonic stem cells to airway epithelium, in 2D and 3D culture, by developing appropriate bioprocessing technology. Firstly, the 2D differentiation process of human and murine ES cells into pulmonary epithelial cells was addressed. The main finding in was that the proportion of type II pneumocytes, the major epithelial component of the gas-exchange area of lung, differentiated with this method was higher than that obtained in previous sudies, 33% of resultant cell expressed the specific marker surfactant protein C (SPC) compared with up to 10%. Secondly, the maintenance and differentiation was carried out in 3D. A protocol was devised that maintained undifferentiated human ES cells in culture for more than 200 days encapsulated in alginate without any feeder layer or growth factors. For ES cell differentiation in 3D, a method was devised to provide a relatively cheap and simple means of culture and use medium conditioned by a human pneumocyte tumour cell line (A549). The differentiation of human and murine ES cells into pulmonary epithelial cells, particularly type II pneumocytes, was found to be upregulated by culture in this conditioned medium, with or without embryoid body formation. The third step was to test whether this differentiation protocol was amenable to scale-up and automation in a bioreactor using cell encapsulation. It was possible to show that encapsulated murine ES cells cultured in static, co-culture or rotating wall bioreactor (HARV) systems, differentiate into endoderm and, predominantly, type I and II pneumocytes. Flow cytometry revealed that the mean yield of differentiated type II pneumocytes was around 50% at day 10 of cultivation. The final stage of the work was to design and produce a perfusion system airlift bioreactor to mimic the pulmonary microenvironment in order to achieve large scale production of biologically functional tissue. The results of these studies thus provide new protocols for the maintenance of ES cells and their differentiation towards pulmonary phenotypes that are relatively simple and cheap and can be applied in bioreactor systems that provide for the kind of scale up of differentiated cell production needed for future clinical applications

    Effect of Psychological Empowerment and Transformational Leadership on Organizational Commitment

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    According to recent literature that relates to organizational leadership, transformational leadership consists of three important elements: idealized influence, individual consideration and intellectual stimulation. Extant studies in this area highlighted that the ability of the leaders in implementing these transformational processes (to execute organizational functions) may have a significant impact on individual outcome especially organizational commitment. Although this relationship has been studied, the mediating role of transformational leadership has taken a less prominent role in organizational leadership model. Recent studies on organizational leadership have emphasized that transformational leadership has three important characteristics: idealized influence, individual consideration and intellectual stimulation. The purpose of this paper is to examine the influence of empowerment in the relationship between transformational leadership and organizational commitment; by using 77 USAble questionnaires gathered from employees who worked at a foreign manufacturing company in Free Trade Zone, Malaysia. Results of SmartPLS path model analysis confirm that empowerment does act as an important mediating variable in the relationship between transformational leadership and organizational commitment in the organizational sample. In the succeeding sections, discussion, implications and conclusion are elaborated

    Supplier-contractor partnering impact on construction performance: A study on Malaysian construction industry

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    The construction sector plays an important role in the national economy through strengthening and enabling other sectors.Construction provides basic amenities and infrastructures that support social development.Despite its important contribution, the industry is still saddled with serious problems such as poor quality, low productivity, poor image, economic volatility, bureaucratic delays, and cost overruns.With an eye to overcoming these problems, this paper proposed a study on supplier-contractor partnering and its impact on construction performance

    Cytotoxicity and anticancer activity of Donkioporiella mellea on MRC5 (normal human lung) and A549 (human lung carcinoma) cells lines

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    Polypores are mushrooms which are rich in bioactivities and for generations, they have been widely used as herbal remedies. Despite their significant importance in treatments of various health issues, only a few local species have been reported for their pharmacological potentials. The present study was carried out to establish cytotoxicity potentials of Donkioporiella mellea, a local polypore species collected from forested areas in Malaysia at cellular levels on normal human lung (MRC5) and human lung carcinoma (A549) cell lines. Survival and inhibition rates were analyzed by 3-(4, 5)-dimethylthiahiazo (-z-y-l)-2,5-diphenyltetrazoliumbromide (MTT) while monitoring changes on cellular shapes by inverted phase contrast microscopy. Survival rates of MRC5 cells were observed to be significantly higher than A549 after treatments with various concentrations of polypore extracts. MRC5 cells showed excellence in survival performance when treated with hot and cold aqueous extracts. Cold aqueous extract showed higher cytotoxicity activities compared to hot aqueous extract () with inhibitory concentration (IC50) values of 414.29 μg/ml and >1000 μg/ml, respectively. Treatments with tamoxifen as a control exhibited necrotic features in both cell lines. The results suggest that D. mellea possesses pharmacological potentials that can be utilized for human consumption as a new bioresource alternative, thus encouraging research advancement in mycological and nutraceutical studies

    Buku ilmiah untuk golongan istimewa oleh Penerbit Universiti Putra Malaysia, Serdang Selangor

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    Adakah penerbitan di negara ini, khususnya penerbit di universiti hanya menerbitkan buku ilmiah kepada golongan normal sahaja? Banyakkah judul dan kandungan ilmiah yang dapat dibaca dan dirujuk oleh golongan orang kelainan upaya (OKU) dan ahli keluarganya? Makalah ini memberi tumpuan buku ilmiah untuk golongan istimewa: kajian kes di Penerbit Universiti Putra Malaysia, Serdang Selangor. Kajian ini dijalankan untuk mengenal pasti buku untuk golongan istimewa yang diterbitkan oleh Penerbit Universiti Putra Malaysia (Penerbit UPM), dan membincangkan relevan buku untuk golongan istimewa yang diterbitkan dan dipromosikan kepada umum. Dalam kajian ini, sebanyak 10 judul ilmiah yang berkaitan golongan istimewa dibincangkan dalam penulisan ini kerana dihasilkan oleh penulis dan diterbitkan dalam bahasa Melayu dan English ini boleh menjadi pilihan buku untuk golongan OKU. Prinsip penerbitan iaitu untuk menyebarluaskan pengetahun dan pengalaman hidup di dalam buku kepada masyarakat diterapkan analisis kajian ini. Secara umumnya, penerbitan ilmiah untuk golongan istimewa diperlukan oleh masyarakat umum dan usaha untuk menerbitkannya hendaklah dilakukan oleh penerbit dengan konsisten

    The effect of feed-based vaccination on tilapia farm endemic for streptococcosis

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    A tilapia farm experiencing endemic streptococcosis was selected to study the effect of vaccination with a feed-based vaccine on naturally ocurring streptococcosis. A total of 9000 red tilapia, Oreochromis niloticus × Oreochromis mossambicus of 100 ± 20 g were divided into 9 cages. Fish of Group 1 in cages 1, 2 and 3 were not vaccinated. Group 2 in cages 4, 5 and 6 were vaccinated on days 0 and 14 (single booster) while Group 3 in cages 7, 8 and 9 were vaccinated on days 0, 14 and 42 (double booster). Vaccination was done by oral administration of the feed-based bacterin vaccine at 4% bodyweight. Samples of serum for antibody study and the brain, eyes and kidney for bacterial isolation were collected at 14-day intervals. The study was carried out during the critical months between April and June. Following vaccination and booster, there was significant (p < 0.05) increase in the antibody levels in all vaccinated groups from week 1 that reached the peak at week 3 before declining gradually until week 6. However, second booster on week 6 significantly (p < 0.05) increased the antibody level that remained high until the end of the 16-week study period (double booster). Streptococcus agalactiae was isolated at the start of the experiment (day 0) at an average of 10 ± 5.0% of the sampled fish. In week 4, the isolation rate was 13 ± 5.7% but increased to 18 ± 7.6% in week 8, to 25 ± 10.0% in week 10, to 28 ± 5.8% in week 12 and 25 ± 7.3% in week 14. The average isolation rate was 28 ± 7.2%, 18 ± 7.1% and 13 ± 8.2% of the fish sampled from unvaccinated, single booster and double booster groups, respectively. At the end of the study period, the survival rate was 45.2 ± 2.45% for unvaccinated, 65.3 ± 4.8% for single booster and 75.1 ± 2.1% for double booster groups. Vaccinating fish in endemic farm might not eliminate the disease but was able to significantly improve the survival rate

    Discrimination analysis of hybrid Pangasianodon hypophthalmus (Sauvage, 1983) (♀) × Pangasius nasutus (♂) (Bleeker, 1976) and its parental species

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    Comparative analysis was performed to discriminate a hybrid produced from the crossbreed of Pangasianodon hypophthalmus (♀) and Pangasius nasutus (♂) and its parental species based on morphology appearances and morphometric characters. Morphological structures of the vomerin and palatal teeth varied between the hybrid and both parents. Results of the univariate analysis revealed 22 morphometric characters were significantly different between the hybrid and its parental species. Under the stepwise discriminate function analysis, the first Function explained 86.10% of total variations and 13.90% in Function 2. Of the 30 characters, only 10 characters which include prepelvic, caudal peduncle length, dorsal fin length, pectoral fin length, anal fin height, anal fin length, adipose fin length, interorbital length, distant to isthmus, and predorsal length can be used to significantly differentiate these species. The predicted fish groups exhibited characters which 100% differentiate and validate them into their respective group. Examination on vomerin and palatal teeth distinct the hybrid and its parental species

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Interpopulation crosses, inheritance study, and genetic variability in the brown planthopper complex, Nilaparvata lugens (Homoptera: Delphacidae)

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    Studies on hybridization, inheritance, and population genetics of brown planthoppers that infest rice and weeds were undertaken using starch gel electrophoresis to determine whether the weed-infesting population represents a biological race or a species. F(1) and F(2) generations were produced by crosses between parental insects from the two populations with little indication of hybrid sterility. Gpi, Mdh, and Idh loci were inherited in a simple Mendelian fashion in families of two sympatric populations. Sixteen populations of Nilaparvata spp. from eight locations were collected. The Mdh, Idh, Pgm, Gpi, 6Pgd, and Acp loci were polymorphic. The N. lugens of rice with high esterase activity were clustered into a group and characterized by the presence of alleles Gpi (110) and Gpi (120), whereas N. lugens from weeds with low esterase activity were clustered into another group and characterized by Gpi (100) and Gpi (90) . There was a lack of heterozygotes between the common alleles of the two populations. This means that the two groups of individuals belong to different gene pools
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