Oriented Collagen and Applications of Waveguide Evanescent Field Scattering (WEFS) Microscopy

In this thesis, Waveguide Evanescent Field Scattering (WEFS) microscopy is developed as a non-invasive, label-free live cell imaging technique. This new high-contrast imaging can be employed to study the first hundred nanometers from the surface as it utilizes the evanescent field of a waveguide as the illumination source. Previously, waveguide evanescent field fluorescence (WEFF) microscopy was developed as a fluorescence imaging technique comparable to the total internal reflection fluorescent (TIRF) microscopy. Both the WEFF and WEFS technique utilizes the same fundamental concepts except in WEFS microscopy imaging is accomplished without the application of any fluorescent labeling. In this work, bacterial biofilms and osteoblasts were cultured on waveguides and imaged with WEFS microscopy. It was possible to detect cell-substrate interactions as well as imaging of cell membrane and cytoplasmic granularity with this microscopy. This non-invasive microscopy can have wide applications for real time imaging of live/dead cells with enhanced sensitivity and contrast. One of the major investigations in tissue engineering is the fabrication of biomaterials that can serve as cell responsive scaffolds. In the present work, collagen thin films were fabricated on hydrophobic glass substrates employing Langmuir-Blodgett (LB) technology. Different orientation distributions of collagen fibrils were found using various geometrical shaped hydrophobic glass substrates. It was observed that the substrate geometry plays a significant role for the collagen orientation distribution. The different orientations of the collagen on the thin films were found to be dependent on the direction of dipping, flow parameters on the LB trough and size and shape of the substrates. The collagen films were also found to be stable under different temperature and solvent conditions for up to three months. The oriented collagen films need to be tested in the future for their application as waveguide coatings for WEFF and WEFS microscopy

Presentation of invasive cervical cancer in Bangladesh

Background: Cervical cancer is a disease of significant worldwide morbidity and mortality. More than 85% of the disease occurs in developing countries. Bangladesh, like other developing countries faces a burden of the disease. ObJec­tive: To find out the different way of presentation of invasive cervical cancer patients. Methods: This cross-sectional study was carried out in the Gynaecologic Oncology wing of the Department of Obstetrics and Gynaecology of Bang­abandhu Sheikh Mujib Medical University (BSMMU) during 1st January 2007 to 30th April 2008. One hundred and four patients with invasive cervical cancer admitted in hospital were enrolled in the study by purposive sampling. All the infor­mation were collected in a pre-designed structured questionnaire. Data were analyzed using statistical program SPSS version: 17.0. Frequency distributions were used to present the characteristics of the patients. Chi-square test was calcu­lated and the significant level was set at P<0.05. Results: Maximum patients (60.6%) were in stage II. Majority of the patients (61.5%) presented with abnormal bleeding. Exophytic growth was found in the majority of the patients (71.2%). Squamous cell carcinoma was more (92.3%) in the majority of patients and adenocarcinoma was more in younger age group. Conclusion: The status of the patients irJ this study reflects advanced stage of the disease at presentation and the peak incidence was observed in 36-45 years age group

Orientation Distribution of Highly Oriented Type I Collagen Deposited on Flat Samples with Different Geometries

The structural arrangement of type I collagen in vivo is critical for the normal functioning of tissues, such as bone, cornea, tendons and blood vessels. At present, there are no established low-cost techniques for fabricating aligned collagen structures for applications in regenerative medicine. Here, we report on a straightforward approach to fabricate collagen films, with defined orientation distributions of collagen fibrillar aggregates within a matrix of oriented collagen molecules on flat sample surfaces. Langmuir Blodgett (LB) technology was used to deposit thin films of oriented type I collagen onto flat substrates exhibiting various shapes. By varying the shapes of the substrates (e.g. rectangles, squares, circles, parallelograms, and various shaped triangles) as well as their sizes, a systematic study on collagen alignment patterns was conducted. It was found that the orientation and the orientation distribution of collagen along these various shaped substrates is directly depending on the geometry of the substrate and the dipping direction of that sample with respect to the collagen/water subphase. An important factor in tissue engineering is the stability, durability and endurance of the constructed artificial tissue, and thus its functioning in regenerative medicine applications. By testing these criteria we found that the coated films and their alignments were stable for at least three months under different conditions and, moreover, that these films can withstand temperatures of up to 60°C for a short time. Therefore, these constructs may have widespread applicability in the engineering of collagen-rich tissues

Presentation of invasive cervical cancer in Bangladesh

Background: Cervical cancer is a disease of significant worldwide morbidity and mortality. More than 85% of the disease occurs in developing countries. Bangladesh, like other developing countries faces a burden of the disease. ObJec­tive: To find out the different way of presentation of invasive cervical cancer patients. Methods: This cross-sectional study was carried out in the Gynaecologic Oncology wing of the Department of Obstetrics and Gynaecology of Bang­abandhu Sheikh Mujib Medical University (BSMMU) during 1st January 2007 to 30th April 2008. One hundred and four patients with invasive cervical cancer admitted in hospital were enrolled in the study by purposive sampling. All the infor­mation were collected in a pre-designed structured questionnaire. Data were analyzed using statistical program SPSS version: 17.0. Frequency distributions were used to present the characteristics of the patients. Chi-square test was calcu­lated and the significant level was set at P<0.05. Results: Maximum patients (60.6%) were in stage II. Majority of the patients (61.5%) presented with abnormal bleeding. Exophytic growth was found in the majority of the patients (71.2%). Squamous cell carcinoma was more (92.3%) in the majority of patients and adenocarcinoma was more in younger age group. Conclusion: The status of the patients irJ this study reflects advanced stage of the disease at presentation and the peak incidence was observed in 36-45 years age group