19 research outputs found
Mass transfer, mixing, Chinese hamster ovary cell growth and antibody production characterization using Rushton turbine and marine impellars:
No full textLarge scale production of monoclonal antibodies has been carried out over the years using bioreactors with different length to diameter ratios, and diverse impeller and sparger designs. The differences in these physical attributes often result in dissimilar mass transfer, shear dynamics and mixing inside the bioreactor, that lead to disparities in cell growth and antibody production. A rational analysis of impeller design parameters on cell growth, protein expression levels and subsequent antibody production is needed to understand such differences and has not been investigated in depth before. The purpose of this study was to examine the impact of Rushton turbine and marine impeller designs on Chinese hamster ovary (CHO) cell growth and metabolism, and antibody production and quality. Experiments to evaluate the mass transfer and mixing characteristics were conducted to determine if the nutrient requirements of the culture would be met. The analysis of mixing times indicated significant differences between marine and Rushton turbine impellers at the same power input per unit volume of liquid (P/V). However, no significant differences were observed between the two impellers at constant P/V with respect to oxygen and carbon dioxide mass transfer properties. Experiments were conducted with CHO cells to determine the impact of different flow patterns arising from the use of different impellers on cell growth, metabolism and antibody production. The analysis of cell culture data did not indicate any significant differences in any of the measured or calculated variables between marine and Rushton turbine impellers. A deterministic model was constructed to describe culture behavior under the different flow patterns and the parameters were solved for both marine and Rushton turbine impellers. This work was intended to bridge the gap in understanding the relationship between impellers with different flow patterns and their effect on CHO cells and productivity. Literature in this area has been inadequate and therefore this work is a significant advancement in this area. More importantly, this study was able to demonstrate that the quality of the antibody was not altered with a change in the impeller geometry, which is of critical importance to the biopharmaceutical industry today.Ph.D.Includes bibliographical references (p. 113-118)by Sandeepa Sandad
Within-Host Dynamics of Multi-Species Infections:Facilitation, Competition and Virulence
No full textHost individuals are often infected with more than one parasite species (parasites defined broadly, to include viruses and bacteria). Yet, research in infection biology is dominated by studies on single-parasite infections. A focus on single-parasite infections is justified if the interactions among parasites are additive, however increasing evidence points to non-additive interactions being the norm. Here we review this evidence and theoretically explore the implications of non-additive interactions between co-infecting parasites. We use classic Lotka-Volterra two-species competition equations to investigate the within-host dynamical consequences of various mixes of competition and facilitation between a pair of co-infecting species. We then consider the implications of these dynamics for the virulence (damage to host) of co-infections and consequent evolution of parasite strategies of exploitation. We find that whereas one-way facilitation poses some increased virulence risk, reciprocal facilitation presents a qualitatively distinct destabilization of within-host dynamics and the greatest risk of severe disease.</p
Gardner syndrome
No full textA 58-year-old male patient was referred for a panoramic radiograph after having presented with a hard swelling of the right mandible. Panoramic radiographic examination (Fig. 1) demonstrated multiples dental anomalies and variable bone densities in both jaws prompting clinicians to “dig” further. Teeth 17, 12, 11, 26 and 27 were missing. Teeth 13, 23, 24, 25, 38, 34, 33 and 43 were unerupted. An unerupted supernumerary left mandibular molar appeared in the region of the mandibular coronoid process. Multiple, small, well-defined radiopacities of density comparable to odontogenic material were evident in the anterior maxilla and mandible. These opacities often demonstrated radiolucent borders consistent with the finding of multiple odontomas. Both jaws demonstrated variable bone density. Cottonwool like opacities partially blending into adjacent trabeculae were evident in the mandible and maxilla posteriorly. The contour of the inferior border of the mandible bilaterally in proximity to the angle was irregular with multiple, well-defined, smooth, lobulated homogenous radiopacities suggestive of osteomas. The radiographic features of multiple osteomas, odontomas, variable bone density, supernumerary and unerupted teeth warranted the referral of the patient for gastroenterological investigation to exclude Gardner Syndrome
Antipsoriatic potential of Annona squamosa seed oil: An in-vitro and in-vivo evaluation
No full textBackground
Corticosteroids remains compound of choice for topical treatment of psoriasis. Several side effects associated with chronic application of corticosteroids limit its uses. Hence, there is a need to find a safe and effective alternative agent for psoriasis treatment.
Purpose
The study aimed to investigate the in vitro and in vivo efficacy of petroleum ether extract of Annona squamosa seeds (ASO) as an antipsoriatic agent. The toxicity profile of ASO and its effect on psoriasis-induced inflammation has also been determined.
Methods
Physicochemical characterization was performed to determine constituents of ASO. Anti-proliferative activity of ASO was studied by Sulforhodamine B (SRB) assay using HaCaT cell lines. Oxazolone-induced psoriasis in female Balb/C mice was used as an animal model for investigating in-vivo efficacy of ASO. Inflammatory markers were analyzed by immunohistochemical staining of mice ears. Safety profile of ASO was confirmed by performing acute dose dermal toxicity and repeated dose dermal toxicity testing.
Results
Predominant presence of polyunsaturated fatty acids viz. linoleic acid and oleic acid in ASO was confirmed by 1H NMR, 13C NMR and GC-MS analysis. The petroleum ether extract of Annona squamosa seeds showed inhibition of cell proliferation of keratinocytes (HaCaT cells). The growth inhibitory property of ASO was significantly higher than that was observed in presence of corticosteroid, clobetasol propionaste (CP). Application of ASO to the ears of Balb/C mice with oxazolone induced psoriasis showed marked reduction in erythema and edema, which was comparable to treatment with 0.05% CP cream. The increased levels of cytokines IL6, IL17, TNF-α, INF-γ, GMCSF, and infiltration of CD4 T cells observed in psoriasis lesions were decreased upon application of ASO. Acute and repeated dermal toxicity studies of ASO did not reveal any adverse events affirming the safety of ASO.
Conclusion
The present data has demonstrated that ASO is a safe and effective anti-psoriatic agent when tested in animal models. The efficacy of ASO in preclinical studies could further be exploited for the development of potential topical antipsoriatic agent for therapy in human
Maxillofacial Radiology 195
No full textA 48 year old asymptomatic male patient presented with a mass on the left maxilla with a reported awareness of two years. Clinical examination revealed normal mucosa overlying buccal and palatal swellings in dental region extending from the 23 to 27. Tooth 26 was missing and teeth 24, 27 and 28 demonstrated displacement
A Review of the role of Nuclear Medicine Imaging in Diagnostic Dentistry
No full textThe increasing scope of nuclear medicine imaging as a diagnostic utility is impressive. Plain film radiographs, computed tomography (CT) scans and magnetic resonance imaging (MRI) diagnostically provide high-quality images but provide little physiological information about disease processes. Nuclear medicine imaging modalities advantageously can characterise the early dynamic physiological changes in a diseased environment. Dental professionals working within the arena of integrated holistic health practices are likely to encounter patients having had procedures like conventional scintigraphy, single photon emission computed tomography (SPECT), hybrid SPECT/CT and positron emission tomography computed tomography (PET/CT). The aim of this review is to acquaint the oral health care professional with some commonly utilised nuclear medicine techniques, the principles upon which such modalities are based and their applications in the diagnosis of head and neck pathology to facilitate enhanced multidisciplinary patient management
Cone beam computed tomography use in sialolithiasis of the submandibular salivary gland
No full textA 62-year-old diabetic male patient presented with right sided facial pain associated with a firm palpable mobile mass in the right submandibular area. Following initial examination, cone beam computed tomography (CBCT) investigation demonstrated multiple smooth homogenous calcifications (Figure 1) collectively measuring 12mm x 9mm x 8mm within the region of the right submandibular gland (Figure 2). On resection of the submandibular gland, the histological features of the lesion were confirmed to be those of chronic sclerosing sialadenitis supporting the clinical impression of a sialolith
Political Opinion Mining and Analysis for Social Media
No full textComputational approaches to opinion mining have mostly focused on sentiment classification for reviews or blogs such as product reviews. This thesis analyses socio-political opinion mining to determine sentiment or stance towards a given target of interest, particularly for social media such as Twitter and Facebook. We explore the tasks of automatically determining from political opinion in social media whether the author of a given text is positive or negative towards a target and aspects of the target, a problem known as fine-grained opinion mining, and in favour or against a target, a problem known as stance detection.
The main contribution of this thesis is the introduction of two novel probabilistic topic models for fine-grained opinion mining and stance detection for political opinion analysis from social media. Such models are capable of representing all the variables of interest simultaneously and considering dependencies between variables. Further, the ability to train the models in a weakly supervised approach, without the use of labelled corpora, is another advantage of the proposed models.
The first model, called Joint Entity-Aspect-Sentiment (JEAS), is based on Latent Dirichlet Allocation (LDA), which detects the target entity, aspects of the entity and sentiment towards entity and aspect simultaneously from the text. The underlying hypothesis of the JEAS is that sentiment of an opinion is dependent on both target entity and aspect. The second model, Joint Sentiment-Issue-Stance (JSIS), also based on LDA, detects target issues and stance simultaneously from text. In JSIS, the stance is generated conditioned on both issues and sentiment distributions.
The proposed models have been evaluated on Twitter and Facebook datasets in the political domain. The experimental results of both models illustrate the effectiveness of the proposed models and confirm the validity of the underlying hypotheses of each model by outperforming baselines for document-level classification tasks. Additionally, both models are capable of learning coherent and informative topic words related to each variable in the models
