Commensal bacteria anginosus group of streptococci [AGS] and cystic fibrosis pathogen PS. aeruginosa in a biofilmcontent: an in vitro study

OBJECTIVE: The objective of the study was to investigate the application on growth of anginosus group of Streptococci [AGS] by Ps. aeruginosa when grown together, and the effect on the virulence of Ps. aeruginosa when grown together with AGS on a biofilm model

METHODOLOGY: In this study we used nitrocellulose filter paper as biofilm model representing the lung epithelium. The AGS strains used were AGS F [S. constellatus from bronchiectasis], AGS 3a [S. anginosus from cystic fibrosis exacerbation], AGS PC 4890 [S. anginosus from dental plaque], AGS 2227 [S. Intermedius from unknown source], AGS EF 52 [S. contellatus from supra gingival plaque], AGS AC 9612 [S. anginosus from supra gingival dental plaque], AGS AM 699 [S. constellatus from supra gingival dental plaque] and AGS 1a [S. anginosus from cystic fibrosis exacerbation]. Ps. aeruginosa strain used was LES 1 [Liverpoolepidemic strain of Ps. Seruginosa]

RESULTS: A concentration of AGS strain in monoculture [1x10[-5]cfu], Ps. aeruginosa monoculture [1x10[-5]cfu], AGS+Ps. aeruginosa mixed culture [1x10[-5]cfu of each] was used to inoculate the biofilm. NAS agar plate and PIA agar plates were used to count the growth of AGS and Ps. Aeruginosarespectively, and pyocyanin and elastase assays were done to check the virulence of the Ps. aeruginosa. It was observed that there was a 10 folds increase in the growth of all the AGS strains; when grown in co-culture with the Ps. aeruginosa strain as compared to when grown in mono culture; both in the 24 and 48 hours aerobically incubated biofilms. When grown in an anaerobic environment AGS in monoculture had the same growth as when grown aerobically with Ps. aeruginosain co culture

There was no effect in the growth of Ps. aeruginosa in mono or co culture with AGS in 24 and 48 hours biofilm

CONCLUSION: The data supported the hypothesis that anginosus group of Streptococci grows better in presence of Ps. Aeruginosain a co-culture, as compared to when grown alone in an anaerobic environment, whereas the virulence factors [ Pyocyanin and Elsastase production] of Ps. aeruginosa increases when grown in co-culture as compared to when grown alone in aerobic conditions

Rate of apical extrusion of sodium hypochlorite: open ended versus closed ended needles

The objective was to compare the role of needles design [open ended versus closed ended] on the apical extrusion of sodium hypochlorite irrigant during root canal treatment. This was an in vitro study performed at the Department of Operative Dentistry, Liaquat University of Medical and Health Sciences, Jamshoro from March 2011 to October 2011. Access cavities were prepared in one hundred extracted human maxillary first molars. The mesiobuccal canal was left open whereas the remaining canals were sealed. The acrylic receptacles were used to hold the teeth in a position as they are present in maxillary arch naturally. The starch/KI solution [A reagent that changes into blue color when comes in contact with sodium hypochlorite] was used to fill the receptacles. The teeth were divided into two groups [G1 and G2] each contained 50 specimens respectively. G1: Irrigation of the mesiobuccal canals with 5.25% sodium hypochlorite with open ended beveled needle. G2: Irrigation of the mesiobuccal canals with 5.25% sodium hypochlorite with closed ended side vented needle. Patency file was #10 K in both the groups. The change in any color of starch/KI solution was captured with digital photographs. Results showed overall frequency of apical extrusion of sodium hypochlorite is 43% [43/100]. There was higher extrusion incidence with open ended beveled needle which was 62% [31/50] than with closed ended side vented needle which showed 24% [12/50]. It was concluded that rate of extrusion was significantly high with open ended beveled needle than with closed ended side vented needle. A closed ended side vented needles appeared significantly safer than open ended beveled needles

Determinants of upper limb amputations in a tertiary care center, Pakistan

To determine the frequency and causes of accidental upper limb amputations seeking rehabilitation [prosthesis] care in a tertiary care center. Observational Descriptive Study. This study was carried out at outpatients Department of Institute of Physical Medicine and Rehabilitation at Dow University of Health Sciences, Karachi from Jan 2007 to Dec 2010. The Sampling Technique was non Probability Purposive sampling. A study specific Performa was prepared which included patient age, stump complications, level of amputation and associated risk factors. The data was analyzed in SPSS version 15. The Mean+/-SD age of ULA was 28.56 +/- SD 11.97 [years]. Most ULA were reported from Karachi 65 [67.7%]. Labourers were the most commonly affected groups 33 [34.4%].Accidents leading to ULA were reported in 89 [92.70] and machine injury [chaff cutting] was responsible in one third of the ULA. Quarter of the ULA had leading cause electric injury. Only, 16 [16.7%] amputees had road traffic accidents. The study concluded that majority of upper limb amputation were caused by machine accidents affecting mostly labourers. Therefore, machine safety protocols for labourers, farmers and workers should be implemented in their local language and through pictoral messages and inbuilt safety measures machines should be sold by company representatives