Neuroprotective effects of nitrone radical scavenger S-PBN on reperfusion nerve injury in rats

The nitrone-based free radical scavengers have potent neuroprotective activities in models of stroke in which oxidative stress plays a key role in its development. We examined the effects of S-PBN (sodium 4-[(tert-butylimino) methyl]benzene-3-sulfonate N-oxide), a spin trap nitrone, on reperfusion injury in rat peripheral nerves. Immediately after the onset of 4-h ischaemia in rat right hindlimb, S-PBN was administered via mini-osmotic pumps, containing 2 ml of S-PBN (1.2 M), inserted subcutaneously. S-PBN, in addition, was given by a single injection (50 mg/kg BW, i.p.). Mean plasma concentrations of S-PBN were significantly greater in S-PBN-treated rats than in controls after 24, 48 and 72 h of reperfusion. Pump and dosing solution analysis indicated that the rats received between 82 and 99% of the target S-PBN concentration. Morphology in sciatic, tibial and peroneal nerves was assessed after 4 h of ischaemia followed by 72 h and 7 days of reperfusion. After 72 h of reperfusion, saline-treated control rats showed endoneurial oedema at the thigh level and diffuse axonal degeneration of myelinated nerve fibres distally. S-PBN-treated nerves were normal or revealed less severe abnormalities in myelinated fibres after 72 h and 7 days of reperfusion, when compared with those in saline-treated control nerves. Morphometrically, the frequency of abnormal myelinated fibres at calf levels was significantly less in S-PBN-treated nerves than in controls. In conclusion, post-ischaemic administration of S-PBN exhibits substantial neuroprotective properties in ischemia/reperfusion nerve injury.     

Targeted mass treatment for syphilis with oral azithromycin

From mid 1997 to end of 1999, there was a sexually-transmitted infectious syphilis outbreak mainly in heterosexual people in British Columbia, Canada, that was concentrated in Vancouver. The rate across the province increased from less than 0.5 to 3.4 per 100000, and the rate in Vancouver reached 12.9 per 100000. We aimed to eliminate the syphillis outbreak by treating people at risk of infection. In 2000, a targeted mass treatment programme provided azithromycin (1.8 g orally) to 4384 at-risk residents in this city. After the programme, syphilis frequency fell significantly for 6 months (p=0.016), but rose again in 2001. Results from curve fitting analyses showed that the number of cases in 2001 (177) was higher than expected (0.0001相似文献   

Management of the primary cutaneous lymphomas

Cutaneous lymphomas are rare and, although some are a manifestation of systemic lymphoma, the majority arise primarily from the skin. These primary cutaneous lymphomas comprise both T- and B-cell subtypes and represent a wide spectrum of disorders, which at times can be difficult to diagnose and classify. Classical therapeutic strategies include topical corticosteroids, phototherapy, radiotherapy, retinoids, extracorporeal photopheresis, topical chemotherapy, systemic chemotherapy and biological response modifiers. Newer therapies include the synthetic retinoid bexarotene, the immunotoxin conjugate denileukin diftitox, interleukin-12 and monoclonal antibodies such as alemtuzumab and rituximab.     

Rosacea: a cutaneous marker of Helicobacter pylori infection? Results of a pilot study

Given the long purported anecdotal association between rosacea and gastrointestinal disease, the discovery that Helicobacter pylori causes gastritis and duodenal ulcer disease has led to a hypothesized role for this organism in the aetiology of rosacea. We conducted a case-series study of 49 patients to assess the potential association between severity of rosacea and direct and serological evidence of H. pylori infection. Patients were classified by severity into non-inflammatory erythematotelangiectatic or inflammatory/papulopustular rosacea and were tested for current H. pylori infection and evidence of previous exposure. Positive 13C-urea breath test and ELISA tests were more likely to be observed in patients with inflammatory rosacea, although not statistically significantly so (OR = 3.0, p = 0.15 and OR = 2.9, p = 0.16, respectively). However, the proportion of patients who tested positive in both assays (versus negative in at least one) was even higher in the inflammatory rosacea group and neared statistical significance (OR = 4.5, p = 0.06). This pilot study provides sufficient evidence suggestive of a positive association between the severity of rosacea and the presence of H. pylori to warrant further research.     

Effect of smoking and sun on the aging skin

Smoking and ultraviolet radiation are known to have a detrimental effect on human skin. Important characteristics of the aging skin are elastosis and telangiectasia. The purpose of the study was to assess the relative importance of age per se, and the detrimental effects caused by sun exposure and smoking on the development of cutaneous elastosis and telangiectasia in a well-defined group of individuals. We made use of 966 individuals who participated in a case-control study to investigate environmental and genetic risk factors for skin cancer. Exposure measurements for sunlight and smoking were collected and the amount of elastosis and telangiectasia in the face and neck was recorded according to a four-graded score varying from none to severe. Relative risks were estimated using exposure odds ratios from cross-tabulation and logistic regression. Multivariate logistic regression was used to adjust for potential confounders. Among both sexes a strong association was observed between increasing age, sun exposure, and amount of elastosis. The association between increasing age, sun exposure, and amount of telangiectasia was strong among men, but less apparent among women. Smoking was also associated with elastosis among both sexes, and with telangiectasia predominantly among men. Intrinsic differences between men and women (e.g., hormones) or behavior differences (e.g., more frequent use of creams and cosmetics among women) could account for this apparent difference in the occurrence of telangiectasia. In contrast to elastosis, telangiectasia may not be a good marker of the aging skin, specifically not in women.     

A longitudinal study of incremental expansion using a mandibular lip bumper

A retrospective study using models was performed to evaluate the incremental expansion that occurred during mandibular lip bumper therapy in 44 adolescent patients. The purpose was to determine whether expansion occurs evenly between appointments or whether it attenuates with treatment time. Dental cast measurements were made for arch width and arch length. Treatment duration was broken into near-equal time segments and compared. Results showed that about 50% of the total expansion achieved occurred within about the first 100 days. Forty percent of the total amount of expansion occurred during the next 200 days, with only about 10% of the total expansion occurring after the first 300 days. It is unnecessary to have the appliance in place for longer than 300 days. The percentage of expansion that occurred at each time segment was not related to whether the patient had concomitant maxillary expansion.     

Are nicotine replacement strategies to facilitate smoking cessation safe?

Professional obligations to curb the prevalence of cigarette smoking reflect the importance of this preventable risk factor for innumerable diseases. These include chronic obstructive pulmonary disease and oral, lung and other cancers, although the morbidity and mortality rates for cerebrovascular disease (e.g., ischemic strokes) and cardiovascular disease (e.g., ischemic myocardial infarction) tend to be greater. Various alternative nicotine sources (e.g., transdermal nicotine patches, nicotine gum, nicotine nasal sprays) have been incorporated into smoking cessation programs. This review is intended to increase professional awareness of nicotine delivery systems available in Canada, including safety considerations. The pathogenic potential of nicotine, regardless of source, and the contraindications to the use of nicotine replacement therapies are discussed. However, the systemic nicotine load in individuals undergoing replacement therapy is generally lower than during active smoking. Nicotine is only one of many thousands of constituents of tobacco smoke. Furthermore, nicotine replacement is usually delivered over the short term (a matter of weeks). Therefore, nicotine replacement is recognized as a relatively safe and effective aid to smoking cessation.