Comparative study to evaluate the antibacterial effect of 3 different forms of calcium hydroxide used in root canal treatment.

The antimicrobial effectiveness of three different forms of calcium hydroxide in root canals of extracted human teeth was compared. Canals were enlarged and inoculated with S. aureus, Str. faecalis. E. coli and Ps. aeruginosa in pure forms as well as in different combinations. After treatment with the tested forms of calcium hydroxide [powder, paste and points] and sealing, the roots were incubated at 37 C. At intervals, 0 hour, 24 hour, 48 hour, 72 hour and 7 days, a set of root canals was analyzed for the viability of bacterial strains. All tested forms of calcium hydroxide exhibited similar antibacterial activity against all bacteria and bacterial mixtures included in the study. Str. faecalis was the most sensitive one [after 24 hour] followed by E. coli [after 48 hour], while S. aureus and Ps. aeruginosa as well as the mixtures used were inactivated after 72 hour exposure. A similar comparative study was done on thirty patients having single rooted teeth with necrotic pulps and indicated for root canal treatment. Intracanal culture samples were taken before canal preparation for bacterial count. Patients were divided into three groups, each group received an interappointment dressing of one form of calcium hydroxide. Cultures were repeated at 3, 7 and 10 days and the antibacterial effect of different forms was expressed as percentage reduction of the viable bacterial count compared to the baseline cultures

Evaluation of a single tube medium, Y-nitrophenyl-phi-D galactopyranoside phenylalanine motility sulphate for screening pathogenic members of the family enterobacteraceae

Identification of members of the Enterobacteriaceae requires the application of biochemical tests before serological confirmation. Of the important tests in such a setting are ONPG, phenylalanine deaminase, motility, H2S and indole production. ONPG-PA-M sulfate medium is a semisolid medium in which all these reactions can be detected. The present study evaluated this medium for detecting such reactions in comparison to the diagnostic set in the microbiology lab [TSI, MIO and urease] and the standard API 20-E system for enterobacteria were evaluated. The reactions of 192 gram negative isolates from stool and other clinical specimens [urine, pus and sputum] as well as 63 control strains were compared. All tested strain showed identical reactions in the three sets, except for a missed positive ONPG reaction in the ONPGPA-M sulfate medium [by an atypical E. coli] and two missed H2S production in the TSI that were detected by the single tube medium [one E. coli and one Cit. freundii]. The ONPGPA-M sulfate medium appeared to be a reliable in assessing these reactions and even superior to TSI in detecting H2S, in addition to the cost reduction achieved by performing all these tests in a single tube. Thus, its use in routine microbiology laboratories was recommended

Serum nitrite and nitrate levels in cirrhotic patients: relationship to endotoxemia

Cirrhotic patients exhibit several hemodynamic alterations manifested by tendency to arterial hypotension. Nitric oxide, the potent vasodilator substance, has been postulated to play a major role in these hemodynamic dysfunction. Serum nitrite and nitrate levels with determination of plasma endotoxin and aldosterone levels were evaluated in 40 patients with liver cirrhosis in addition to 10 healthy control subjects. The patients were further classified into 3 groups: Group 1 included 17 pafeitns with compensated cirrhosis, group II: 14 patients with decompensated cirrhosis and ascites and Group III included 9 patients with decompensated cirrhosis, ascites and functional renal failure. Serum nitrite/nitrate and endotoxin levels were significantly increased in cirrhotic patients compared to healthy controls, particularly in decompensated patients. Nitrite/nitrate levels directly correlated with endotoxin levels and aldosterone levels respectively. In conclusion our results suggested that circulating endotoxins in cirrhotics might be responsible for excessive synthesis and release of nitric oxide which may play a key role in hemodynamic dysfunction in cirrhotic patients