Context: Limited evidence exists to guide the optimal frequency of repeat endoscopic examination for colorectal cancer screening after a negative colonoscopy. Objective: To determine the duration and magnitude of the ...Context: Limited evidence exists to guide the optimal frequency of repeat endoscopic examination for colorectal cancer screening after a negative colonoscopy. Objective: To determine the duration and magnitude of the risk of developing colorectal cancer following performance of a negative colonoscopy. Design, Setting, and Patients: Population-based retrospective analysis of individuals whose colonoscopy evaluations did not result in a diagnosis of colorectal neoplasia. Patients who had been evaluated between April 1, 1989, and December 31, 2003, were identified using Manitoba Health’s physician billing claims database (N = 35 975). Standardized incidence ratios (SIRs) were calculated to compare colorectal cancer incidence in our cohort with colorectal cancer incidence in the provincial population. Stratified analysis was performed to determine the duration of the reduced risk. Patients with a history of colorectal cancer prior to the index colonoscopy, inflammatory bowel disease, resective colorectal surgery, and lower gastrointestinal endoscopy within the 5 years before the index colonoscopy were excluded. Cohort members were followed up from the time of the index colonoscopy until diagnosis of colorectal cancer, death, out-migration from Manitoba, or end of the study period on December 31, 2003. Main Outcome Measure: Incidence of colorectal cancer. Results: A negative colonoscopy was associated with SIRs of 0.69 (95%confidence interval [CI], 0.59-0.81) at 6 months, 0.66 (95%CI, 0.56-0.78) at 1 year, 0.59 (95%CI, 0.48-0.72) at 2 years, 0.55 (95%CI, 0.41-0.73) at 5 years, and 0.28 (95%CI, 0.09-0.65) at 10 years. The proportion of colorectal cancer located in the right side of the colon was significantly higher in the colonoscopy cohort than the rate in the Manitoba population (47%vs 28%; P< .001). Conclusions: The risk of developing colorectal cancer remains decreased for more than 10 years following the performance of a negative colonoscopy. There is a need to improve the early detection rate of right-sided colorectal neoplasia in usual clinical practice.展开更多
BackgroundAcne affects 83- 95% of 16- year-oldsof both sexes, and many seek help from a clinician. Emerging problems with conventional acne treatments, specifically antibiotic resistance of Propionibacterium acnes and...BackgroundAcne affects 83- 95% of 16- year-oldsof both sexes, and many seek help from a clinician. Emerging problems with conventional acne treatments, specifically antibiotic resistance of Propionibacterium acnes and fears over th e safety and tolerance of oral isotretinoin, create a demand for novel treatment modalities in acne. Objectives To study the efficacy of aminolaevulinic acid- photodynamic therapy (ALA-PDT) in the treatment of acne and to identify the mode of acti on, looking specifically at the effects on surface numbers of P. acnes and on se bum excretion. Methods Ten patients (nine men and one woman, age range 16- 40 y ears) with mild to moderate acne on their backswere recruited. Each patient’s backwasmarkedwith four 30- cm2 areas of equal acne severity. Each site was then randomly allocated to either ALA-PDT treatment, light alone, ALAalone or an u ntreated control site. At baseline, numbers of inflammatory and noninflammatory acne lesions were counted, sebum excretionmeasured by Sebutapes (CuDerm, Dallas, TX, U.S.A.) and surface P. acnes swabs performed. ALA cream (20% in Unguentum Merck) was applied under occlusion to the ALA-PDT and ALA alone sites for 3 h . Red light from a diode laser was then delivered to the ALA-PDT and light alo ne sites (635 nm, 25 mW cm- 2, 15 J cm- 2). Each patient was treated weekly fo r 3 weeks. At each visit acne lesion counts were performed and 3 weeks following the last treatment sebum excretion rates and P. acnes swabs were repeated. Resu lts There was a statistically significant reduction in inflammatory acne lesion counts from baseline after the second treatment at the ALA-PDT site but not at any of the other sites. No statistically significant reduction in P. acnes numb ers or sebum excretion was demonstrated at any sites including the ALA-PDT sit e. Conclusions ALA-PDT is capable of clinically improving acne. An alternative mode of action for ALA-PDT other than direct damage to sebaceous glands or ph otodynamickilling of P. acnes is suggested from the results of this study.展开更多
Objective:To determine normal concentrations of procalcitonin in preterm infants shortly after birth and to assess its accuracy in detecting bacterial infection. Methods:Blood samples of 100 preterm infants were prosp...Objective:To determine normal concentrations of procalcitonin in preterm infants shortly after birth and to assess its accuracy in detecting bacterial infection. Methods:Blood samples of 100 preterm infants were prospectively drawn during the first 4 days of life for determination of procalcitonin concentration. Infants were classified into four groups according to their sepsis status.Results:Mean (SD) gestational age and birth weight were 32(2.9) weeks and 1682 (500) g respectively. A total of 283 procalcitonin concentrations from healthy infants were plotted to construct nomograms of physiologically raised procalcitonin concentration after birth,stratified by two groups to 24-30 and 31-36 weeks gestation. The peak 95th centile procalcitonin concentration was plotted at 28 hours of age; values return to normal after 4 days of life. Only 12 infants were infected,and 13 of their 16 procalcitonin concentrations after birth were higher than the 95th centile,whereas samples taken at birth were lower.In a multivariable analysis,gestational age,premature rupture of membrane,and sepsis status influenced procalcitonin concentration independently,but maternal infection status did not.Conclusions:The suggested neonatal nomograms of preterm infants are different from those of term infants. Procalcitonin concentrations exceeding the 95th centile may be helpful in detecting congenital infection,but not at birth.展开更多
文摘Context: Limited evidence exists to guide the optimal frequency of repeat endoscopic examination for colorectal cancer screening after a negative colonoscopy. Objective: To determine the duration and magnitude of the risk of developing colorectal cancer following performance of a negative colonoscopy. Design, Setting, and Patients: Population-based retrospective analysis of individuals whose colonoscopy evaluations did not result in a diagnosis of colorectal neoplasia. Patients who had been evaluated between April 1, 1989, and December 31, 2003, were identified using Manitoba Health’s physician billing claims database (N = 35 975). Standardized incidence ratios (SIRs) were calculated to compare colorectal cancer incidence in our cohort with colorectal cancer incidence in the provincial population. Stratified analysis was performed to determine the duration of the reduced risk. Patients with a history of colorectal cancer prior to the index colonoscopy, inflammatory bowel disease, resective colorectal surgery, and lower gastrointestinal endoscopy within the 5 years before the index colonoscopy were excluded. Cohort members were followed up from the time of the index colonoscopy until diagnosis of colorectal cancer, death, out-migration from Manitoba, or end of the study period on December 31, 2003. Main Outcome Measure: Incidence of colorectal cancer. Results: A negative colonoscopy was associated with SIRs of 0.69 (95%confidence interval [CI], 0.59-0.81) at 6 months, 0.66 (95%CI, 0.56-0.78) at 1 year, 0.59 (95%CI, 0.48-0.72) at 2 years, 0.55 (95%CI, 0.41-0.73) at 5 years, and 0.28 (95%CI, 0.09-0.65) at 10 years. The proportion of colorectal cancer located in the right side of the colon was significantly higher in the colonoscopy cohort than the rate in the Manitoba population (47%vs 28%; P< .001). Conclusions: The risk of developing colorectal cancer remains decreased for more than 10 years following the performance of a negative colonoscopy. There is a need to improve the early detection rate of right-sided colorectal neoplasia in usual clinical practice.
文摘BackgroundAcne affects 83- 95% of 16- year-oldsof both sexes, and many seek help from a clinician. Emerging problems with conventional acne treatments, specifically antibiotic resistance of Propionibacterium acnes and fears over th e safety and tolerance of oral isotretinoin, create a demand for novel treatment modalities in acne. Objectives To study the efficacy of aminolaevulinic acid- photodynamic therapy (ALA-PDT) in the treatment of acne and to identify the mode of acti on, looking specifically at the effects on surface numbers of P. acnes and on se bum excretion. Methods Ten patients (nine men and one woman, age range 16- 40 y ears) with mild to moderate acne on their backswere recruited. Each patient’s backwasmarkedwith four 30- cm2 areas of equal acne severity. Each site was then randomly allocated to either ALA-PDT treatment, light alone, ALAalone or an u ntreated control site. At baseline, numbers of inflammatory and noninflammatory acne lesions were counted, sebum excretionmeasured by Sebutapes (CuDerm, Dallas, TX, U.S.A.) and surface P. acnes swabs performed. ALA cream (20% in Unguentum Merck) was applied under occlusion to the ALA-PDT and ALA alone sites for 3 h . Red light from a diode laser was then delivered to the ALA-PDT and light alo ne sites (635 nm, 25 mW cm- 2, 15 J cm- 2). Each patient was treated weekly fo r 3 weeks. At each visit acne lesion counts were performed and 3 weeks following the last treatment sebum excretion rates and P. acnes swabs were repeated. Resu lts There was a statistically significant reduction in inflammatory acne lesion counts from baseline after the second treatment at the ALA-PDT site but not at any of the other sites. No statistically significant reduction in P. acnes numb ers or sebum excretion was demonstrated at any sites including the ALA-PDT sit e. Conclusions ALA-PDT is capable of clinically improving acne. An alternative mode of action for ALA-PDT other than direct damage to sebaceous glands or ph otodynamickilling of P. acnes is suggested from the results of this study.
文摘Objective:To determine normal concentrations of procalcitonin in preterm infants shortly after birth and to assess its accuracy in detecting bacterial infection. Methods:Blood samples of 100 preterm infants were prospectively drawn during the first 4 days of life for determination of procalcitonin concentration. Infants were classified into four groups according to their sepsis status.Results:Mean (SD) gestational age and birth weight were 32(2.9) weeks and 1682 (500) g respectively. A total of 283 procalcitonin concentrations from healthy infants were plotted to construct nomograms of physiologically raised procalcitonin concentration after birth,stratified by two groups to 24-30 and 31-36 weeks gestation. The peak 95th centile procalcitonin concentration was plotted at 28 hours of age; values return to normal after 4 days of life. Only 12 infants were infected,and 13 of their 16 procalcitonin concentrations after birth were higher than the 95th centile,whereas samples taken at birth were lower.In a multivariable analysis,gestational age,premature rupture of membrane,and sepsis status influenced procalcitonin concentration independently,but maternal infection status did not.Conclusions:The suggested neonatal nomograms of preterm infants are different from those of term infants. Procalcitonin concentrations exceeding the 95th centile may be helpful in detecting congenital infection,but not at birth.
