Application of a novel high resolution widefield surface plasmon microscope in cell engineering, wound healing and development of new binding assays

Surface Plasmon (SP) microscope systems are mostly built around the prism based Krctschmann configuration. In thcsc systcms the generation of Surface Plasmons (SPs) is achieved by p-polarized light striking a metallised prism surfacc at a spccific angle and then monitoring thc intensity of the reOected light. Thus in these systems. an image of the material can be obtained in terms of an intensity map. in which the intcnsity of thc image is dcpendent on the way the light couples into the SPs. The drawback of these systems is that lateral resolution relies on the ability of plasmons to propagate along the metallised layer. The lateral resolution is thus limited to a few microns. Therefore, a new microscope systcm was developed. i.e. thc Widcficld Surface Plasmon Resonance (WSPR) microscope. that is not only capable of analysing molecular interactions at high vertical resolutions. but also enables SP imaging at much higher lateral resolution than prism based systcms. The functionality of thc novel (WSPR) microscope has been investigated by imaging a scquence of binding events between micropattcrncd cxtracellular matrix proteins and their specific antibodies both in air and real-time. Using the WSPR systcm a changc in contrast was observed with each protein binding cvcnts. Images produced via the WSPR system were analyzcd and comparcd qualitatively and quantitatively. The preliminary results acquired for these binding studics between antibody/antigens dcmonstrate that the WSPR systcm capablc of resolving features down to 260nm although the theoretically proven lateral resolution of the WSPR system is -500nm. Cell surface interactions undcr two diffcrent culture conditions. i.e. HaCaTs cultured on SPR substrate with Transforming Growth Factor ~3 (TGF~3) (50ng/lII/) and without TGF~3 were also invcstigated. It was found that I-IaCaTs cultured in the presence of TGF~3 showed enhanced division and motility along with decreased cell attachmcnt as compared with cclls maintained in TGF~3 free media. It is believed that cellular signalling by TGF~3 is very important for enhancing tissue development in wound rcpair. It is confirmed that the WSPR microscope described here can be used to study sequential monomolecular layer of antibody/antigen interactions binding cvents and examination of cell surface intcrfacial intcractions at latcral scales of less than one micron without the need for traditional immunoOuorescent labelling. These rcsults have significant implications in the developmcnt of ncw brecd fast binding assays system and in enabling high resolution detailed examination of the cell surface couplings and ccll signalling proccsses involvcd in cell attachmcnt and migration

Impact of Exchange rate Volatility on Growth and Economic Performance: A Case Study of Pakistan, 1973-2003

This paper investigates the impact of volatility of exchange rates on the manufactured production of Pakistan’s economy. After a short introduction of the underlying theories and empirical literature, the relationship between these two variables is estimated. In the regression, the conditional variance of the real exchange rate is the measure of uncertainty (GARCH estimation). The results obtained are positive but are insignificant, and do not support the position that excessive volatility or shifting of exchange rate regimes has pronounced effects for manufacturing production. These results are consistent with what we obtain from the impulse responses. It is believed, however, that the thesis adds to the body of evidence, suggesting that exchange rate variability has no significant effect on manufacturing products.

Serological and Molecular Investigation of Brucella Species in Dogs in Pakistan

Brucellosis is an important bacterial zoonosis caused by B. abortus and B. melitensis in Pakistan. The status of canine brucellosis caused by B. canis remains obscure. In total, 181 serum samples were collected from stray and working dogs in two different prefectures viz. Faisalabad (n = 87) and Bahawalpur (n = 94). Presence of antibodies against B. canis and B. abortus/B. melitensis was determined using the slow agglutination test (SAT) and ELISA, respectively. Real-time PCR was performed to detect and differentiate Brucella DNA at the species level. In Faisalabad, the serological prevalence was found to be 9.2% (8/87) and 10.3% (9/87) by SAT and ELISA, respectively. Only one of the ELISA positive samples (1.15%) yielded amplification for B. abortus DNA. In Bahawalpur, 63.8% (60/94) samples were found positive by SAT; however, none of the samples was positive by ELISA or by real-time PCR. Location, age (≥1 year) and body condition (weak) were found to be associated with B. canis infection, whereas presence of wounds was found to be associated with B. abortus infection only. These findings point towards a risk of transmission from dog to livestock and humans and vice versa. The study expects to draw the attention of concerned authorities towards infection prevention and animal welfare. This study warrants further epidemiological investigation on brucellosis in pet dogs and their owners. To the best of our knowledge, this is first ever report on B. canis and B. abortus in dogs in Pakistan