Occurrence,Efficacy, Metabolism,and Toxicity of Triclosan

Triclosan has broad-spectrum anti-microbial activity against most gram-negative and gram-positive bacteria. It is widely used in personal care products, household items, medical devices, and clinical settings. Due to its extensive use, there is potential for humans in all age groups to receive life-time exposures to triclosan, and, indeed, triclosan has been detected in human tissues and the environment. Data gaps exist regarding the chronic dermal toxicity and carcinogenicity of triclosan, which is needed for the risk assessment of triclosan. The US Food and Drug Administration (FDA) nominated triclosan to the National Toxicology Program (NTP) for toxicological evaluations. Currently, the NTP is conducting several dermal toxicological studies to determine the carcinogenic potential of triclosan, evaluate its endocrine and developmental-reproductive effects, and investigate the potential UV-induced dermal formation of chlorinated phenols and dioxins of triclosan. This paper reviews data on the human exposure, environmental fate, efficacy of anti-microbial activity, absorption, distribution, metabolism and elimination, endocrine disrupting effects, and toxicity of triclosan.     

Safe conversion of mycophenolate mofetil to azathioprine in kidney transplant recipients with sirolimus-based immunosuppression

Aim:   Mycophenolate mofetil (MMF) is a powerful immunosuppressive drug with established efficacy and safety. The long-term use of MMF may bring increased risk of for infection and malignancy and also increased cost of transplantation. The search for minimization of immunosuppressive protocol has led to an open randomized clinical trial of conversion from MMF to azathioprine (AZA).
Methods:   A total of 50 kidney allograft recipients treated with prednisone, sirolimus and MMF were randomized into two groups: converted (AZA group) and continuing (MMF group). The average duration of MMF therapy prior to conversion was 43 months in each group. Inclusion criteria included: patients with serum creatinine levels of less than 200 µmol/L; no past history of acute vascular rejection or recent acute rejection 6 months before randomization; and normal liver function tests.
Results:   Baseline demographics were similar in the two groups. During the 12 month observation period, there were no acute rejection episodes in either group. There were no significant differences in overall patient or graft survival or function. AZA-treated patients had a lower incidence of gastrointestinal complications ( P  = 0.03). Daily cost reduction in the AZA group was more than $US8.79/day per patient.
Conclusion:   In general, replacing MMF with AZA in stable renal transplant recipients is well tolerated and was cost effective with no increased risk of rejection. As the this study was on relatively small samples, larger and longer follow-up studies will be needed to confirm these expected advantages for the long-term outcome and to assess the long-term safety of this minimization of immunosuppressive therapy.     

Diagnostic Value of Comparison of Ventriculoatrial Interval During Junctional Tachycardia and Right Ventricular Apical Pacing

We postulated that comparison of ventriculoatrial intervals during junctional tachycardia and during right ventricular apical pacing may provide similar diagnostic information to that obtained from the insertion of ventricular extrasystoles during tachycardia. We studied 39 patients with either atrioventricular reentrant tachycardia (AVRT) (23 patients) using a single atrioventricular accessory pathway or atrioventricular nodal reentrant tachycardia (AVNRT) (16 patients). Ventriculoatrial [VA] intervals were measured during tachycardia, during right ventricular apical pacing at the same rate as that of the tachycardia and following a ventricular extrasystole delivered at the minimum reset interval (minimum prematurity of a ventricular extrasystole required to advance the subsequent atrial complex by more than 10 msec). The difference between the minimum VA interval during tachycardia and during ventricular pacing was closely related to both the minimum reset interval (r = 0.92, P less than 0.001) and the difference between the minimum VA interval during tachycardia and following a ventricular extrasystole delivered at the minimum reset interval (r = 0.97, P less than 0.001) in the 23 patients in whom the minimum reset interval could be determined. The ratio between the minimum ventriculoatrial interval during tachycardia and ventricular pacing could be determined in all cases and was between 1.53 and 1.68 in AVRT with right free wall (two patients), 0.94 and 1.29 with anteroseptal (three patients), 0.91 and 1.08 with posteroseptal (five patients) and 0.48 and 0.71 with left free wall (13 patients) pathways, while it was between 0.32 and 0.27 in AVNRT (16 patients). The ratio was more discriminative when corrected for ventricular latency and was also useful when calculated from the high right atrial electrogram. We concluded that comparison of ventriculoatrial intervals during junctional tachycardia and during right ventricular apical pacing can discriminate between the mechanisms of tachycardia and the site of pathway. It provides similar information to that obtained from ventricular extrasystoles during tachycardia with the advantage that it can be determined in all cases.(ABSTRACT TRUNCATED AT 400 WORDS)     

Flexural Strength and Modulus Properties of Carbamide Peroxide–Treated Bovine Dentin

Background : The effects of carbamide peroxide bleach on tooth structure are uncertain.
Purpose : The purpose of this study was to investigate the effects of direct or indirect carbamide peroxide application on dentin flexural strength and modulus in vitro.
Materials and Methods : Dentin bars were machined from bovine incisors and treated with 10% carbamide peroxide for 6 h/d for 14 days. Four groups were created, with eight bars in each group: group 1–direct bleach application only; group 2–indirect bleach application only; group 3–direct bleach application followed by a 2–week storage in artificial saliva; group 4–direct bleach application followed by a 2-week storage in artificial saliva and daily topical fluoride treatments. The specimens' flexural strength and modulus were tested after 24 hours, and the results were compared with water controls using independent t -tests ( p < .05).
Results : Flexural strength results (in megapascals) for bleached versus control dentin (1 = 205 ± 26 vs 215 ± 14,2 = 257 ± 25 vs 261 ± 14,3 = 180 ± 22 vs 193 ± 36, 4 = 157 ± 18 vs 184 ± 11) were significantly lower in group 4 ( p = .005). Modulus results (in gigapascals) for bleached versus control dentin (1 = 10.7 ± 1.4 vs 12.2 ± 0.6, 2 = 14.2 ± 1.7 vs 14.4 ± 1.6, 3 = 10.0 ± 2.0 vs 10.9 ± 1.3, 4 = 9.0 ± 1.2 vs 11.1 ± 1.0) were significantly lower in groups 1 and 4 ( p = .013 and p = .003, respectively). There were no significant differences in strength and modulus results between the bleached and control dentin in groups 2 and 3. A direct application of carbamide peroxide to bovine dentin significantly decreased some dentin mechanical properties in vitro. An indirect application of carbamide peroxide to dentin did not significantly decrease dentin strength and stiffness.     

染色体异常致反复和后代5p12-15.3三体:一对叙利亚夫妇报道及文献复习（英文）

在本研究中,我们介绍一叙利亚夫妻发生孕早期反复流产、胎儿畸形和/或新生儿死亡。经检查,父亲表型正常,有一个平衡的染色体易位t(5;15),在无精子症因子(AZF)b座位s Y125基因发生了微缺失而且其伴有MTHFRC677T纯合子基因多态性。值得注意的是,他的妻子则伴有MTHFRA1298C纯合子基因多态性。这对夫妻经历了两次流产,有2个夭折的孩子均为严重畸形,为5号染色体短臂部分三体。夫妻结婚10年后没有任何存活后代。