Residual glutaraldehyde levels in fiberoptic endoscopes: measurement and implications for patient toxicity

Most gastroenterology societies recommend glutaraldehyde for fiberoptic endoscope disinfection. However, glutaraldehyde toxicity has been suspected in patients examined with endoscopes disinfected with this compound. The aim of our study was to determine the residual levels of glutaraldehyde in fiberoptic endoscopes after either manual or automatic disinfection and to evaluate the extent of toxicity. Furthermore, the procedures for disinfection currently performed by the department were compared with the new French guidelines. We used both manual and automatic disinfection procedures and flushed sterile distilled water through the lumens of endoscopes before use. Residual glutaraldehyde levels were determined using liquid chromatography coupled to spectrophotometric detection. In a total of 92 measurements it was found that residual glutaraldehyde levels were higher and more variable after manual disinfection (< 0.2-159.5 mg/L) than after automatic disinfection (< 0.2-6.3 mg/L). We conclude that local procedures for disinfection need to be improved to conform to the new French guidelines. Since thresholds for the toxic dose of glutaraldehyde and international norms for levels of residual glutaraldehyde in equipment have not been defined, additional studies combining accurate measurements in fiberoptic endoscopes and clinical observations of endoscopy patients will be required to draw more definitive conclusions.     

醇对戊二醛鞣制的牛心包防钙化改性的实验研究

目的本实验采用几种醇改性戊二醛处理后的牛心包,希望寻找一种理想的生物瓣处理方法。方法分为五组,即新鲜对照组及戊二醛、2,3-丁三醇、1,3-丙二醇、1,2-丙二醇组。分组将牛心包试片植入SD大鼠背部皮下60d后,行组织钙定量测定及组织学检测。结果2,3-丁二醇改性后的牛心包试片钙平均含量为3.99±0.96ug/mg干重,与GA组、1,2-丙二醇,1,3-丙二醇试片的钙平均含量(241.89±7.79、244.26±6.39、167.32±12.29ug/mg干重)相比,钙化,钙化明显减轻(均P＜0.01),但与对照组(4.11±2.23ug/mg干重)相比无显著性差异(P＞0.05)。病理组织学检查显示2,3-丁二醇组和1,3-丙二醇组试片仅有轻度形态学改变。而GA组和1,2-丙二醇组试片有严重的胶原变性,大片钙化。结论戊二醛鞣制的生物材料经2,3-丁二醇改性后,可显著减轻钙化。     

牛颈静脉带瓣管道的抗钙化研究进展

应用带瓣管道重建右心室流出道是治疗复杂先天性心脏病的一项重要手段。近年来,戊二醛处理的牛颈静脉带瓣管道被广泛应用于临床,但术后管道钙化、衰败问题一直未得到解决。目前抗钙化处理方法有去细胞、染料介导光氧化、环氧化合物、组织工程等,但单一方法往往不能取得令人满意的效果,多种方法联合处理将是组织工程技术发展的方向。     

Augmented Latex‐Specific IGE Antibody Response in BALB/c Mice Upon Concurrent Exposure to Natural Rubber Latex Proteins with Glutaraldehyde

Health care workers are exposed to numerous agents that are known to induce hypersensitivity‐mediated diseases. Yet, little is known regarding the role of coexposure to these agents on the development of hypersensitivity responses. The present studies were conducted to evaluate the immunomodulatory role of dermal exposure to glutaraldehyde (Glut) on the induction of IgE antibodies to natural rubber latex (NRL) proteins. Female BALB/c mice were dermally exposed to Glut (0.05–1 ppm; 0.1–1%) and nonammoniated latex (NAL; 25 µg) 5 days/week for up to 86 days. The NAL alone at concentrations up to 1% did not induce significantly elevated levels of total serum or latex specific IgE. In contrast, both total and NAL‐specific serum IgE were dose‐dependently (p < 0.01 and p < 0.05, respectively) elevated in mice concurrently exposed to 25 µg NAL and increasing concentrations of Glut up to 0.75 ppm. Further testing was performed to investigate the mechanism by which Glut augmented the latex‐specific response. Barrier integrity tests demonstrated that Glut did not induce sufficient disruption of the strateum corneum (less than 1% ³H₂0 penetration was observed in a guinea pig model) to allow for increased penetration of the latex proteins. However, co‐exposure to 25 µg NAL and 0.75 ppm Glut for 2 days as compared to the vehicle control was shown to induce a 15‐fold increase in MHC II positive Langerhans' cells in the epidermis. Additional experiments confirmed the upregulation of a Th2 response. Upon sacrifice following 86 days of exposure, animals exposed to 25 µg NAL and 0.75 ppm Glut demonstrated a significant increase (p < 0.01) in CD40 + (3.95 ± 0.38 × 10⁶), B220 + (7.67 ± 1.18 × 10⁶), and IgE + B220 + (3.28 ± 0.75 × 10⁶) cells as compared to the vehicle control groups (2.29 ± 0.18 × 10⁶, 3.31 ± 0.18 × 10⁶, and 0.82 ± 0.15 × 10⁶ cells), respectively. These studies demonstrate the potential for mixed exposures in the health care environment to modulate the development of IgE mediated responses to natural rubber latex proteins, underscoring the importance of environmental factors in the development of allergies to foreign antigens.     

Development of a carbon nanotubes paste electrode modified with crosslinked chitosan for cadmium(II) and mercury(II) determination

A functionalized carbon nanotubes paste electrode modified with cross-linked chitosan for the determination of trace amounts of cadmium(II) and mercury(II) by linear anodic stripping voltammetry is described. Under optimal experimental conditions, the peak current was linear in the Cd(II) concentration range from 5.9 × 10⁻⁸ to 1.5 × 10⁻⁶ mol L⁻¹ with a detection limit of 9.8 × 10⁻⁹ mol L⁻¹ and, for Hg(II) from 6.7 × 10⁻⁹ to 8.3 × 10⁻⁸ mol L⁻¹with a detection limit of 2.4 × 10⁻⁹ mol L⁻¹. The proposed method was successfully applied for the determination of Hg(II) in natural and industrial wastewater samples, and Cd(II) in sediments, human urine, natural, and industrial wastewater samples.     

环氧氯丙烷改性戊二醛处理对猪主动脉根部构型的影响

但仅R和N之间差异有统计学意义(P＜0.05).结论 EC改性GA处理对瓣膜主动脉壁尺寸的改变不明显,但对瓣叶尺寸的改变差异有统计学意义.     

HPLC法测定稀戊二醛溶液中戊二醛含量

目的：建立HPLC法测定稀戊二醛溶液中戊二醛含量的方法。方法：采用AichromBond-AQ C18色谱柱（4.6mm＆#215;150mm,5μm）,流动相：甲醇∶水（50∶50）,流速0.5ml/min,检测波长235nm,进样量20μl。结果：戊二醛在51.6～1010.4μg/ml范围内时,与峰面积呈良好的线性关系（r=0.9992）,平均回收率为101.1%。结论：本法操作简便,灵敏度高,重复性好,可用于稀戊二醛溶液中戊二醛的含量控制。     

In vitro evaluation of plant-derived agents to preserve dentin collagen

Objective

Biomodification of dentin by a natural crosslinker has been recommended to improve a mechanical property of demineralized dentin. This study investigated the effect of various plant-derived agents (hesperidin, proanthocyanidin, epigallocatechin gallate and genipin) on the stability of dentin collagen matrix to resist collagenase degradation.

Methods

The dentin specimens were treated with glutaraldehyde (0.5% and 5.0%) and each plant-derived test solution (0.5%). They were subjected to ultimate tensile strength (UTS) and swelling ratio measurements. Demineralized human dentin powder was incubated with 0.02%, 0.1% and 0.5% of each test agent and followed by bacterial collagenase digestion. The extent of collagen degradation was investigated using hydroxyproline assay.

Results

The UTS and swelling ratio measurements revealed that the mechanical property of dentin was improved by the use of these natural agents. The greatest reduction in collagen degradation was shown following the use of hesperidin, proanthocyanidin, and epigallocatechin gallate at 0.5%.

Significance

The use of hesperidin, proanthocyanidin, and epigallocatechin gallate could improve the mechanical properties of collagen and resist enzymatic degradation, leading to functional repair of pathological dentin lesion.     

用于乙肝表面抗原及其抗体同步检测压电免疫传感器阵列的研制

目的：研制同步检测HBsAg和anti—HBs的压电免疫传感器阵列。方法：采用戊二醛交联法，将乙肝表面抗体及其抗原固定于石英晶体表面，同步检测HBsAg和anti—HBs。结果：该阵列对HBsAg和anti—HBs能进行定性定量分析，可以明显区分阴阳性对照血清，以阳性频移值为信号，阴性频移值为噪声，其信噪比均大于2；其线性范围分别为1～25μg／ml和0．032～1．6mg／ml。结论：该阵列具有临床推广应用价值。     

Meniscal material properties are minimally affected by matrix stabilization using glutaraldehyde and glycation with ribose.

Knee meniscus replacement holds promise, but current allografts are susceptible to biodegradation. Matrix stabilization with glutaraldehyde, a crosslinking agent used clinically to fabricate cardiovascular bioprostheses, or with glycation, a process of crosslinking collagen with sugars such as ribose, is a potential means of rendering tissue resistant to such degradation. However, stabilization should not significantly alter meniscal material properties, which could disturb normal function in the knee. Our objective was to evaluate the effects of glutaraldehyde- and glycation-induced matrix stabilization on the material properties of porcine meniscus. Normal untreated meniscus specimens were tested in confined compression at one of three applied stresses (0.069, 0.208, 0.347 MPa), subjected to either a glutaraldehyde or glycation stabilization treatment, and then re-tested to measure changes in tissue aggregate modulus, permeability, and compressive strain at equilibrium. Changes in these properties significantly increased with glutaraldehyde concentration and exposure time to ribose. One glutaraldehyde and three glycation treatments did not alter aggregate modulus or compressive strain at equilibrium compared to controls (p > 0.10). However, all treatments increased permeability by at least 108% compared to controls (p < 0.001). This study reveals a dose-dependent relationship between meniscal material properties and certain stabilization conditions and identifies treatments that minimally affect these properties. Further research is necessary to determine whether these treatments prevent enzymatic degradation before and after surgical implantation in the knee.