Is the oral fungal pathogen Candida albicans a cariogen?

Pathobiology of dental caries is complex. Data from recent molecular microbiologic studies have further redefined the role of the oral microbiome in the etiology of dental caries. This new information challenges the conventional view on the hegemony of classic cariogenic prokaryotes such as Streptococcus mutans in caries etiology, and raises the intriguing possibility of the participation of the eukaryotic oral fungal pathogen Candida in the caries process. The virulence attributes of Candida species such as their acidogenicity and aciduric nature, the ability to develop profuse biofilms, ferment and assimilate dietary sugars, and produce collagenolytic proteinases are all indicative of their latent cariogenic potential. Based on the above, oral candidal counts have been used by some as a caries risk indicator. On the contrary, other studies suggest that Candida is merely a passenger extant in an acidic cariogenic milieu, and not a true pathogen. In this review, we critically examine the varying roles of Candida, and traditionally accepted cariogens such as the mutans group of streptococci in the pathobiology of dental caries. The weight of available data tends to imply that Candida may play a pivotal role as a secondary agent perpetuating the carious process, especially in dentinal caries.     

Fungal infections associated with HIV infection

Oral candidiasis is perhaps the commonest infection seen in HIV disease. The aim of this workshop was to provide a sketch of the multifarious aspects of the disease from a global perspective. To this end the panellists addressed issues such as the virulence of Candida , emergence of antifungal resistance, management of candidiasis and other exotic, oral mycotic diseases. An all-pervasive theme was the dramatic differences in the management of fungal infections consequential to the availability (or the lack) of anti-HIV drugs in the developed and the developing world. Further, the social stigmata associated with the HIV disease in many developing regions in Africa and Asia appears to modify the therapeutic strategies. Additionally, the lesser-known regional variations in the disease manifestations and therapeutic approaches were stark. Further work is direly needed to address these issues.     

Clinical,microbiological and ultrastructural features of angular cheilitis lesions in Southern Chinese

OBJECTIVE: To obtain basetine data on angular cheilitis in Southern Chinese. DESIGN: A cross-sectional investigation of the clinical, microbiological and ultrastructural features of the condition. SUBJECTS AND METHOD: Thirty six Chinese adults with angular cheilitis; 28 controls matched for age and sex, with no inflammation. Clinical examination, swabs of lesions for microbiology, impressions of lesions for ultra-structure, using replica technique. MAIN OUTCOME MEASURES: Severity of lesions, associated signs and symptoms, incidence and type of microorganisms, ultrastructural features. RESULTS: Of a total 68 lesions 32 were bilateral and four unilateral. Forty four (65%) were mild (Type I) and the remaining 24 (35%) moderate (Type 11). Infective agents were isolated from 37 (54%) lesions; pure growth of Candida spp and Staph. aureus was noted in nine lesions each; a mixed growth of the two in I I, beta-haemolytic streptococci in three and a mixed flora including coliforms in the other five. Candida spp were present in one control, beta-haemolytic streptococci in two and coliforms in four others. Scanning etectron microscopy revealed natural topography of the angular skin with sparse colonisation by bacteria and yeasts. CONCLUSIONS: Angular cheilitis in Southern Chinese seems to be characterised by a milder clinical presentation and classic infective agents of the disease: Candida spp and Staph. aureus.     

FLUID MECHANICS OF ARTIFICIAL HEART VALVES

• 1 Artificial heart valves have been in use for over five decades to replace diseased heart valves. Since the first heart valve replacement performed with a caged‐ball valve, more than 50 valve designs have been developed, differing principally in valve geometry, number of leaflets and material. To date, all artificial heart valves are plagued with complications associated with haemolysis, coagulation for mechanical heart valves and leaflet tearing for tissue‐based valve prosthesis. For mechanical heart valves, these complications are believed to be associated with non‐physiological blood flow patterns.
• 2 In the present review, we provide a bird's‐eye view of fluid mechanics for the major artificial heart valve types and highlight how the engineering approach has shaped this rapidly diversifying area of research.
• 3 Mechanical heart valve designs have evolved significantly, with the most recent designs providing relatively superior haemodynamics with very low aerodynamic resistance. However, high shearing of blood cells and platelets still pose significant design challenges and patients must undergo life‐long anticoagulation therapy. Bioprosthetic or tissue valves do not require anticoagulants due to their distinct similarity to the native valve geometry and haemodynamics, but many of these valves fail structurally within the first 10–15 years of implantation.
• 4 These shortcomings have directed present and future research in three main directions in attempts to design superior artificial valves: (i) engineering living tissue heart valves; (ii) development of advanced computational tools; and (iii) blood experiments to establish the link between flow and blood damage.

     

膳食补充剂黑醋与红曲单用及联用对中老年人血脂的影响

目的:观察并比较黑醋与红曲单用及联用对中国中老年人降低血脂的效能。方法:试验于2003-10/11在大连医科大学中日合作医药科学研究所进行。选择30名年龄为45￣65岁的中老年人。30名受试者被随机分为3组,每组10人,分别服用黑醋丸6粒,红曲丸6粒或黑醋 红曲丸6粒,1次/d,连续4周;3种膳食补充剂黑醋丸、红曲丸及黑醋 红曲丸由含有不同剂量的黑醋固形物、红曲粉末K-F、柠檬酸钠、大豆油、蜂蜡、脂肪酸甘油脂组成(由日本国第一药品工业株式会社提供)。各组服用剂量分别为每天黑醋固形物360mg,红曲粉72mg及黑醋固形物360mg 红曲粉72mg。服用2和(或)4周后,检测血脂和血糖,同时用血清样品检测肝功与肾功能。实验结果用SPSS统计软件进行方差分析。结果:30名中老年人全部进入结果分析。①受试者连续3d每日营养素摄入量:3组之间热量、胆固醇、膳食纤维、宏量或微量营养素摄入量差距均无显著性。②血清脂质浓度和计算的脂质比:2,4周血清三酰甘油含量,黑醋 红曲组低于基础值(分别下降(24.6±4.9)%,(27.6±3.4)%,P<0.05);红曲组与基础值比较,差异无显著性[分别下降(6.5±3.4)%,(11.6±4.5)%];黑醋组与基础值比较,差异无显著性[分别下降(10.2±7.3)%,(12.4±8.2)%]。2,4周血清胆固醇、低密度脂蛋白胆固醇含量,黑醋 红曲丸、红曲丸和黑醋丸组均比基础值降低,差异无统计学意义。3种膳食补充剂对血清高密度脂蛋白胆固醇及计算的脂质比值无明显改变。血糖含量无变化。未发现对受试对象产生明显不良反应。结论:服用黑醋 红曲丸能明显降低受试者血清三酰甘油含量。黑醋与红曲合用对高脂血症者可能有健康效益。