Snuff use and smoking among senior high school students: effects of a snuff sales ban

OBJECTIVES: The popularity of snuff especially among adolescents is rising. The association between long-term snuff use and oral cancer discovered in epidemiological studies has prompted a variety of preventive measures to be taken to reduce snuff use and prevent adoption of the habit. In this study, the effect of a recent (I March, 1995) snuff sales ban introduced in Finland was investigated. Further, the rates of smoking, snuff use, alcohol use and drug experimenting were investigated before the introduction of the ban to characterize the study population.
DESIGN AND SUBJECTS: Two questionnaire studies were carried out. The first was carried out 3 months prior to the ban in 1994 and the second 9 months after the ban in 1995 in a senior high school population in southwestern Finland. The participants were 793 students (aged 15–22 years) in the first survey and 545 students (aged 16–23) in the second. Associations between variables were analyzed using cross-tabulation and stepwise logistic regression. The effects of the ban were determined on the basis of direct questions in the second questionnaire relating to the snuff sales ban.
RESULTS: Snuff was used by 9% of the students participating in the first study. The results of the second questionnaire indicate that the implementation of the snuff sales ban reduced the rate of snuff use by 1% in the study population. The majority of the snuff users (76%) reported that they had maintained their snuff habit. Of those reporting that they were snuff users before implementation of the snuff sales ban, 12% had switched to smoking and 5% to drugs.
CONCLUSIONS: The results of the present study suggest that the snuff sales ban in this population with a high rate of snuff use had little effect on snuff use rates and may have some short-term negative consequences as some snuff users switch to other substitutes, such as smoking, with known adverse health effects.     

口服糖皮质激素大鼠皮肤组织形态学变化

目的:观察口服糖皮质激素大鼠皮肤形态学改变,为建立新的皮肤衰老动物模型提供形态学上的依据。方法:实验于2006-07/2007-02在广东医学院药理教研室组织药理实验室完成。①实验对象:20只SD雄性SPF级大鼠随机分为两组,糖皮质激素组和空白对照组,每组10只。②实验方法:糖皮质激素组每天口服灌胃糖皮质激素3.5mg/(kg·d),空白对照组每天口服灌胃同等剂量生理盐水,喂养100d后麻醉下处死大鼠,取背部正中1cm×1cm大小皮肤组织检测相关指标。③实验评估:常规苏木精-伊红染色、VanGieson染色法、Weigert-间苯二酚-碱性品红染色法观察皮肤组织形态改变,并用计算机图像分析系统定量分析表皮厚度和弹力纤维总面积。结果:纳入结果分析16只,其中空白对照组8只,糖皮质激素组8只。糖皮质激素组大鼠皮肤表皮变薄,弹力纤维面积减少,胶原纤维多断裂,排列疏松,糖皮质激素组大鼠表皮厚度(33.8±3.1)μm,弹力纤维总面积(3557.9±373.1)μm2,均小于对照组大鼠表皮厚度(63.7±7.4)μm,弹力纤维总面积(5049.0±497.5)μm2。结论:糖皮质激素3.5mg/(kg·d)口服灌胃100d可导致大鼠皮肤衰老样改变,与人类皮肤衰老有相似形态学表现。     

Effects of Short-Term Varenicline Administration on Emotional and Cognitive Processing in Healthy,Non-Smoking Adults: A Randomized,Double-Blind,Study

Varenicline is an effective and increasingly prescribed drug for smoking cessation, but has been associated with depressive symptoms and suicidal behavior. However, it remains unclear whether those changes in mood and behavior are directly related to varenicline use, or caused by smoking cessation itself or reflects depression and suicidality rates in smokers, independent of treatment. To investigate the influence of varenicline on mood and behavior independent of smoking and smoking cessation, we assessed the effects of varenicline on emotional processing (a biomarker of depressogenic effects), emotion-potentiated startle reactivity, impulsivity (linked with suicidal behavior), and cognitive performance in non-smoking subjects. We used a randomized, double-blind design, in which we administered varenicline or placebo to healthy subjects over 7 days (0.5 mg/day first 3 days, then 1 mg/day). Cognitive and emotional processing was assessed by a battery of computerized tasks and recording of emotion-potentiated startle response. A total of 41 subjects were randomized, with 38 subjects included in the analysis. The varenicline group did not differ from placebo in terms of negative biases in emotional processing or mood. However, compared with placebo, the varenicline group scored higher on working and declarative memory. In conclusion, short-term varenicline use did not influence negative biases in emotional processing or impulsivity in non-smoking subjects, thereby not supporting direct depressogenic or suicidal risk behavior-inducing effects. In contrast, varenicline may have cognitive-enhancing effects.     

Failure of Dietary Protein and Phosphate Restriction to Retard the Rate of Progression of Chronic Renal Failure: A Prospective, Randomized, Controlled Trial

SUMMARY Ninety-five patients (63 male, 32 female), age 45±2 years(mean±SEM) with chronic renal failure of varied aetiologywere randomized to receive either a conventional low proteindiet (0.6 g/kg/day protein, 800 mg phosphate; n=33), a low phosphatediet (providing approximately 1000 mg phosphate plus an orallyadministered phosphate binder, minimum protein intake 0.8 g/kg/day;n=30) or to control (minimum protein intake 0.8 g/kg/day, nophosphate restriction; n=32). Patients were reviewed for a minimumof 6 months before randomization and were withdrawn from thestudy if plasma creatinine exceeded 900 µmol/1, plasmaphosphate was > 2.0 mmol/1 or at the onset of uraemic symptoms. Following randomization patients were studied for an averageof 19±3 months. Mean plasma creatinine rose from 398±33to 600±50 µmol/1. Dietary protein intake was estimatedat 0.69±0.02 g/kg/day in the low protein group, 1.02±0.05in the low phosphate and 1.14±0.05 in the controls, phosphateintake was 815±43, 1000± 47, and 1315±57mg/day, respectively. Urinary urea excretion and protein catabolicrates were significantly reduced (p<0.01) only in those onprotein restriction, at 213±9 mmol/24 hours and 0.71g/kg/day, respectively. Phosphate excretion was significantlylower (p<0.05) in both the low protein group (17.9±0.8mmol/24 hours) and the low phosphate group (18.6±1.0mmol/24 hours) compared to controls. Changes in body weight,muscle mass and serum transferrin, albumin and immunoglobulinswere comparable between the groups. Mean blood pressure followingrandomization was 150/89±3/1 (low protein), 148/87±3/1(low phosphate) and 146/87±3/1 (controls). Progression of renal failure was analysed by rate of fall ofcreatinine clearance (ml/min/ 1.73 m²/month), by rate of deteriorationderived from reciprocal plasma creatinine against time plots(1/mmol/year) and to assess individual patient's response totreatment by two phase linear regression (‘breakpoint’)analysis of reciprocal plasma creatinine/time plots. Progressionwas analysed only in patients seen for at least 3 months followingrandomization. The rate of fall of creatinine clearance was not significantlydifferent between the groups (ANOVA): 0.56±0.08 ml/min/1.73m2/month (low protein, n=28), 0.44±0.07 (low phosphate,n=23) and 0.69±0.11 (control, n=27). In 50 patients (18low protein, 16 low phosphate and 16 control) whose rate ofprogression could be calculated before and after randomization,there was a fall in rate of progression averaging 0.18 ml/min/1.73m2/month in those on low protein diet and those on low phosphatediet, but a rise of 0.08 in the controls. These differenceswere, however, not statistically significant. Similar resultswere obtained when the rates of deterioration were calculatedfrom plasma creatinine. Significant individual improvements(p<0.01) in rates of progression by ‘breakpoint’analysis occurred in 17 patients: six on low protein, sevenon low phosphate and in four controls. Sixty-one (72 per cent)of the patients examined by this method showed no significantchange in the rate of progression while seven patients had acceleratedprogression. There was no difference in the requirement formaintenance dialysis facilities between groups. No significant benefit of protein and phosphate restrictionwas therefore demonstrated.     

中药癌痛克对人肝癌细胞HepG2增殖、凋亡及Rb基因表达的影响

目的:通过观察不同浓度癌痛克对肝癌细胞株HepG2增殖及凋亡的作用,以及在相应状态下细胞内Rb基因表达量的改变,探讨中药癌痛克抗肝癌的可能作用机制。方法:实验于2005-09/2006-03在广州医学院中心实验室完成。取对数生长期的HepG2细胞,使细胞静止于G0/G1期。随机分为癌痛克2,10,50mg/L组和对照组,癌痛克2,10,50mg/L组分别加入对应浓度癌痛克(购自河南省肿瘤研究所,由金蝎、土元、九香虫、大黄、人参、灵芝、黄芪等纯中药组成的粉状制剂,功能:消癌肿、消癌痛、消积水、升白排毒),对照组不加药物,每组设4个复孔。MTT法检测各组细胞24,48,72h增殖率,细胞增殖率=[(A570癌痛克组-A570对照组)/A570对照组]×100%;以流式细胞术检测各组细胞24,48,72h凋亡率;RT-PCR方法检测各组细胞24,48,72h细胞内Rb基因mRNA表达量。结果:①2～50mg/L癌痛克具有明显的增殖抑制作用,癌痛克2,10,50mg/L组在24,48,72h与对照组比较,差异有显著性意义(P<0.05);3组各时点两两之间比较差异有显著性意义(P<0.05);同组各时点之间比较差异有显著性意义(P<0.05)。②2～50mg/L癌痛克组可诱导HepG2细胞凋亡,相同作用时间癌痛克2,10,50mg/L组与对照组比较差异有显著性意义(P<0.001);同一时点各组比较差异有显著性意义(P<0.05);同组不同作用时间点比较差异有显著性意义(P<0.001)。③2～50mg/L癌痛克可上调Rb基因的表达,各浓度组在各时点与对照组比较,差异均有显著性意义(P<0.05);24,48,72h癌痛克2,10,50mg/L组之间比较差异无显著性意义(P>0.05);3组各时点比较差异有显著性意义(P<0.05)。结论:中药癌痛克可通过抑制HepG2细胞增殖或诱导其凋亡,而发挥抗肝癌作用;且其诱导细胞凋亡的机制之一可能为通过增加Rb基因的表达而实现。     

A human antibody binds to alpha-galactose receptors and mimics the effects of Clostridium difficile toxin A in rat colon

BACKGROUND & AIMS: Nearly all human sera contain an immunoglobulin G antibody (antigalactose) that binds the trisaccharide Gal alpha 1-3Gal beta 1-4GlcNAc expressed on cells from most mammals but not humans. Because the Clostridium difficile toxin A receptor in rodents contains this trisaccharide, the aim of this study was to examine whether antigalactose could mimic the enterotoxic effects of toxin A and bind to receptors containing this trisaccharide. METHODS: Fluid secretion, [3H]-mannitol permeability, and release of rat mast cell protease II and prostaglandin E2 were measured after luminal exposure of rat colon to either purified human anti-galactose, control immunoglobulin G, toxin A, or buffer. RESULTS: Toxin A (5 micrograms) and antigalactose (250 micrograms) but not control immunoglobulin (250 micrograms) stimulated colonic fluid secretion and caused increased mannitol permeability and rat mast cell protease II release. Antigalactose and toxin A and, to a lesser degree, control immunoglobulin G also stimulated release of prostaglandin E2, but only toxin A produced acute inflammation of rat colonic mucosa. Antigalactose and toxin A bound specifically to a single class of colonic brush border receptors with dissociation constants of 10(-6) mol/L and 5.4 x 10(-8) mol/L, respectively. CONCLUSIONS: Fluid secretion, increased permeability, and mast cell activation occur in rat colon when toxin A or human antigalactose immunoglobulin G bind to receptors bearing the trisaccharide Gal alpha 1-3Gal beta 1-4GlcNAc. (Gastroenterology 1996 Jun;110(6):1704-12)     

FACTOR VIII RELATED ANTIGEN IN CONNECTIVE TISSUE DISEASE PATIENTS AND RELATIVES

This study assayed serum levels of FVIII Rag as a marker ofendothelial injury in patients not only with frank connectivetissue disease but also in those presenting with Raynaud's phenomenonand in families of those with systemic sclerosis. Elevated levelsof FVIII Rag were found in 62% of patients with systemic sclerosis(SS), 38% with systemic lupus erythematosus (SLE), 67% withmixed connective tissue disease (MCTD) and in 17% with primaryRaynaud's phenomenon. Twenty percent of first degree relativesof patients with SS also demonstrated high levels of FVIII Ragand certain antibodies, namely those reacting with U, RNP andthe centromere. The association between elevated FVIII Rag andantibodies linked to Raynaud's and vasculitis lends supportto antibody involvement in pathogenesis. High levels of FVIIIRag in family members may reflect an increased susceptibilityof endothelium to injury particularly since relatives also havea higher frequency of clinical features such as Raynaud's phenomenon. KEY WORDS: Systemic lupus erythematosus, Raynaud's phenomenon, Scleroderma, Mixed connective tissue disease, Vasculitis     

中频交变磁场照射后小鼠的行为学变化

目的:目前电磁辐射对生物体行为学方面的研究还很薄弱,设立不同磁场的强度和不同照射的周期,观察中频领域磁场照射对小鼠的自主活动和学习记忆的影响。方法:实验于2007-05-10/06-15在清华大学医学院和中国医学科学院药用植物研究所完成。①实验材料:磁场发生装置:中频交变磁场发生装置由清华大学工程物理系医学物理与工程研究所自主研发,可产生频率为40kHz,场强为28.8A/m,28.8kA/m的中频交变磁场。自主活动测试箱:中国医学科学院药用植物研究所提供,为一可封闭的金属箱,内置摄像头。4只黑色塑料测试桶分别置于箱子四角。水迷宫测试箱:中国医学科学院药用植物研究所提供。②实验动物及方法:将80只小鼠随机分为不同场强照射组和对照组。强磁场照射1组:11.6kA/m/40kHz,1h/d,连续照射7d。强磁场照射2组:11.6kA/m/40kHz,2h/d,连续照射7d。强磁场照射3组:11.6kA/m/40kHz,2h/d连续照射15d。弱磁场照射组:28.8kA/m/40kHz,2h/d,连续照射7d。对照组除了未放入磁场照射,其他条件与照射组一致。实验过程中对动物处置符合动物伦理学要求。③实验评估:观察其一般活动的改变,并采用自主活动测试箱和水迷宫测试箱进行测试,观察各组小鼠的自主活动和学习记忆的改变。结果:①一般行为观察:与对照组小鼠对比,经过中频交变磁场照射过的各组小鼠活跃度减低,毛色较差。强磁场照射3组(145G,2h/d,连续15d)于第11天和13天分别死亡1只。②自主活动检测结果:强磁场照射2,3组小鼠的运动路程、运动速度、运动时间明显低于对照组(P<0.05)。③水迷宫测试结果:在学习记忆检测阶段撤掉平台,发现各组动物2min内穿越平台原来所在象限的次数没有明显差别(P>0.05)。结论:中频交变磁场照射会给小鼠的自发活动造成一定影响,对学习记忆没有影响。