comparative analysis of bleached and sound enamel structure through scanning electron microscopy and atomic force microscopy

To analyze the effects of bleaching agent on enamel structure and to characterize the morphological and chemical changes in enamel due to bleaching. Experimental study. School of Chemical and Material Engineering [SCME], NUST Islamabad from Feb to May 2013. Ten recently extracted pre molars between the 12-22years age group were randomly assigned into two groups. Group one was a non-bleached control group with sound enamel. Group two was bleachedwith Everbrite In office tooth whitening system after specimen preparation, surface morphology was observed under SEM [scanned electron microscope] and AFM [Atomic force microscope]. Thedetrimental effects of hydrogen per-oxide on enamel were evident in bleached specimens under SEM, and AFM analysis. There were significant surface alterations found in the bleached specimens as compared to control group. However salivary buffering potentials could overcome the demineralizing effect of bleaching gel

Multidrug resistance tuberculosis in Lahore

To estimate drug resistance in TB patients and compare it with the previous studies to see if there is a changing trend. PMRC TB research centre Mayo hospital Lahore which is a specialized centre on research and diagnosis of tuberculosis. The centre receives sputum samples from all the leading hospitals of Lahore. This work was done from 2004 to 2006 where five first lines anti tuberculosis drugs were tested on LJ.medium using standard proportion method. A total of 582 confirmed isolates of Mycobacterium tuberculosis were seen. Of the total 454 were pulmonary and 128 extra pulmonary specimens from 582 patients. These patients comprised of those with and without history of previous treatment. These sputa were subjected to drug susceptibility testing. Almost half of the patients had some resistance; multiple drug resistance [MDR] was seen in 12.8% and 27.0% cases without and with history of previous treatment respectively. Overall resistance to rifampicin was 26.6%, to isoniazid 23.5%, streptomycin 19.5%, ethambutol 11.8%, and to pyrazinamide 29.7%. Statistically significant difference was seen between primary and acquired resistances. When compared with the reports from previous studies from the same area, there was a trend of gradual increase of drug resistance in this area. Resistance to anti tuberculosis drugs is high in Lahore. The current approach may not be adequate and innovative approaches such as DOTS-Plus may have to be employed to effectively control MDR TB

Value of three sputum smears microscopy in diagnosis of pulmonary tuberculosis

Early diagnosis and treatment are essential to prevent transmission of tuberculosis in the community. Smear microscopy with Zeihl-Neelsen [ZN] staining is currently the most feasible microbiological method for diagnosis of pulmonary TB in developing countries due to its rapidity, low cost and high positive predictive value for Mycobacterium tuberculosis. This study was carried out to assess the diagnostic yield of three AFB smears microscopy among suspected pulmonary tuberculosis patients of Lahore district. This descriptive study was conducted at PMRC TB Research Centre King Edward Medical University/Mayo Hospital, Lahore Pakistan where DOTS has been implemented. Patients with respiratory symptoms and or abnormal chest X-rays provided three sputum samples each for acid-fast bacilli smear microscopy. Smears were prepared and stained by Ziehl-Neelsen staining method. In 2006 a total of 2,222 TB suspects submitted three sputum samples on two consecutive days [spot, early morning, spot], therefore 6,666 AFB smear microcopy examinations were performed. The smear positivity rate was 11.5% and 257 [11.56%] suspects fulfilled the case definition of having one positive smear confirmed by a second smear. A total of 438 [19.7%] suspects had a least one positive smear; of these 290 [66.2%] were positive in first smear, 105 [24%] were negative in first smear but positive in second and 43 [9.8%] were positive in third smear after two negative smears. At least three smear microscopy examinations are required for proper diagnosis. The higher diagnostic yield of 9.8% in third smear is indicative of the importance of third smear