A randomised controlled clinical trial to compare the incidence of injury to the inferior alveolar nerve as a result of coronectomy and removal of mandibular third molars

We randomised 128 patients who required operations on mandibular third molars and who had radiological evidence of proximity of the third molar to the canal of the inferior alveolar nerve to one of two operations: extraction [n=102], and coronectomy [n=94]. Some roots were dislodged during intended coronectomy and were therefore removed, resulting in two subgroups (successful coronectomy n=58, and failed coronectomy n=36). The mean (S.D.) follow up was 25 (13) months. Nineteen nerves were damaged (19%) after extraction, none after successful coronectomy, and three (8%) after failed coronectomy (p=0.01). The incidence of dry socket infection was similar in the three groups (10/102, 10%, 7/58, 12%, and 4/36, 11%, respectively). No root required removal or reoperation. To our knowledge this is the first clinical trial of the efficacy of coronectomy in preserving the inferior alveolar nerve. The length of follow up was about 2 years, which for the assessment of delayed eruption of the root fragments is not sufficient as this process may continue for up to 10 years. However, it seems that coronectomy reduces the incidence of injury to the inferior alveolar nerve without increasing the risk of dry socket or infection.     

Demographic characteristics and prevalence of serologic markers among donors who use the confidential unit exclusion process: the Retrovirus Epidemiology Donor Study

BACKGROUND: Most blood centers utilize a confidential unit exclusion (CUE) process, intended to reduce the risk of transfusion-associated infectious diseases by allowing high-risk donors confidentially to exclude their blood from use for transfusion. The effectiveness of this method remains controversial. STUDY DESIGN AND METHODS: Confirmatory or supplemental test results for antibodies to human immunodeficiency virus, human T-lymphotropic virus type I, and hepatitis C virus, as well as hepatitis B surface antigen and syphilis and screening test results for antibodies to hepatitis B core (antigen) and alanine aminotransferase levels were obtained for approximately 1.8 million units donated during 1991 and 1992 at five blood centers within the United States. The prevalences of these infectious disease markers in units that the donors confidentially excluded (CUE+) and units that the donors did not exclude (CUE-) were calculated and examined within demographic subgroups. RESULTS: Units that were CUE+ were 8 to 41 times more likely to be seropositive for antibodies to human immunodeficiency virus and hepatitis C virus, hepatitis B surface antigen, and syphilis and three to four times more likely to react for antibody to hepatitis B core (antigen) or to have elevated alanine aminotransferase levels than units that were CUE- (p < 0.001). The positive predictive value of CUE (the percentage of CUE+ units that were confirmed seropositive for any marker) was 3.5 percent, and the sensitivity of CUE (the percentage of confirmed-seropositive units that were CUE+) was 2.3 percent. CONCLUSION: The current CUE process has low sensitivity and apparently low positive predictive value, and in many cases, it appeared that donors misunderstood it. Yet, CUE was not a “random process,” as CUE+ units were more likely to be seropositive for any infectious disease marker than CUE- units. This suggests that efforts to improve the CUE system may be warranted. As risk factors for transfusion-transmitted infection become more difficult to identify by history-based screening, however, such efforts may have limited effect.     

Total radical trapping antioxidant potential (TRAP) and exercise

The relationship between physical activity, physical fitness and total radical trapping antioxidant potential (TRAP) was examined in the Northern Ireland Health and Activity Survey. This was a cross-sectional population study (n = 1600) using a two-stage probability sample of the population. TRAP was calculated using the sum of the individual serum antioxidant concentrations (urate, protein thiols, ascorbate, alpha tocopherol and bilirubin) multiplied by their respective stoichiometric values. Physical fitness was determined by estimation of VO2max by extrapolation from submaximal oxygen uptake, and physical activity was recorded by computer-assisted interview. Mean serum TRAP concentrations were significantly higher in males (653 +/- 8.2 mumol/l, mean +/- SEM) compared to females (564 +/- 8.0 mumol/l) (p < 0.0001). Both male and female smokers had significantly lower TRAP values than non-smokers (males p < 0.0001, females p = 0.02). In females, there was a positive relationship of TRAP with age (p < 0.001) and body mass index (p < 0.001) but a negative relationship with physical fitness (p < 0.05). The known beneficial effects of exercise and activity do not appear to be directly mediated through increased antioxidant status.      

The association of Chlamydia trachomatis and Mycoplasma genitalium with non-gonococcal urethritis: observations on heterosexual men and their female partners

Our objectives were to study the distribution of Chlamydia trachomatis and Mycoplasma genitalium in men with or without non-gonococcal urethritis (NGU) and their respective female partners. A case-control study was carried out to which men with or without NGU and their female partners were recruited. All study participants were tested for the presence of C. trachomatis and M. genitalium. An analysis firstly of the distribution of each of these microorganisms among men with or without urethritis and their respective female partners was carried out. Furthermore, we examined the association of each of these microorganisms and NGU when the other had been excluded. Chlamydia trachomatis was present in 14 (36%) of 39 men with NGU compared to none of 12 men without NGU (P=0.022). The prevalence rates for female partners of men with NGU were 10 (26%) of 39 compared to none of 12 partners of men without NGU (P=0.092). M. genitalium was detected in 12 (33%) of 36 men with NGU compared to 1 (9%) of men without NGU (not significant; P=0.147). The prevalence rates for female partners of men with NGU were 10 (32%) of 31 women compared to none of 7 partners of men without NGU (not significant; P=0.156). There was a greater concordance than discordance of carriage of each of the 2 microorganisms among the study couples and each tended to be carried independently of the other by men. Analysis of the association between the presence of C. trachomatis in men and NGU was significantly improved by the exclusion of men with M. genitalium (P=0.0058). Likewise, the association between the presence of M. genitalium in men and NGU was significantly improved by the exclusion of couples in whom either the man or woman was C. trachomatis-positive (P=0.049). The independent carriage of C. trachomatis and M. genitalium by men with NGU, coupled with the improved association between each pathogen and NGU by exclusion of the other provides support for the separate role of each in the aetiology of NGU.     

Escherichia coli tetracycline efflux determinants in relation to tetracycline residues in chicken

ObjectiveTo screen for Escherichia coli (E. coli) resistant to tetracycline, followed by identification of tet efflux genes by polymerase chain reaction (PCR). In addition, detection of tetracycline residues in chicken livers and kidneys were conducted using high performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS).MethodsStrains of E. coli were isolated from samples of chicken colon and screened for tetracycline resistance. Tetracycline genes conferring resistance (Tc^r) were detected by polymerase chain reaction (PCR). Most of the isolates were resistant to tetracycline (97.9%).ResultsPCR analysis indicated that Tc^r E. coli R-plasmids contained tet(A), tet(B) and a combination of both efflux genes. None of the isolates contained other efflux tet genes tet (C, D, E and Y). High performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS), a sensitive technique, was used to detect residues of chlortetracycline (CTC), oxytetracycline (OTC), doxycycline (DC) in chicken livers and kidneys. The samples containing tetracycline residues were at 0.13-0.65 pg/μL levels.ConclusionsTetracycline and other antibiotics are commonly used in the poultry and meat production industry for prevention of microbial infections. Multiple antibiotic resistant bacteria in Oman have increased to alarming levels, threatening public health, domestic and may have adverse effect on environment.