不同浓度气态甲醛慢性染毒对小鼠卵泡发育影响的研究

目的:研究不同浓度气态甲醛慢性染毒对小鼠卵泡发育的影响,探讨环境污染导致卵巢性不孕的相关因素。方法:将40只性成熟SPF级雌性昆明小鼠随机分为空白对照组和3个不同浓度(0.1mg/m3、1.0mg/m3、10mg/m3)气态甲醛染毒组(模型组),每组10只。模型组采用不同浓度气态甲醛动态吸入式染毒,6h/d,连续14d,对照组给予吸入过滤的新鲜空气,时间同前。造模成功后处死小鼠,取出卵巢,计算卵巢脏器系数,光学显微镜下观察卵巢组织形态学改变,计数始基卵泡、窦前卵泡、窦状卵泡、排卵前卵泡和闭锁卵泡数。结果:不同浓度气态甲醛慢性染毒均可使小鼠一般状况差,动情周期延长且不规则,卵巢脏器系数降低。各染毒组闭锁卵泡数量增多,中、高浓度染毒组窦前卵泡、窦状卵泡和排卵前卵泡数明显减少,各组间始基卵泡和总卵泡数无明显差异。结论:不同浓度气态甲醛慢性染毒均可影响小鼠发育期卵泡,中、高浓度染毒可导致卵泡不可逆的损害,发育期卵泡数量明显减少。环境污染会诱发不孕症的发生。     

利用不同浓度气态甲醛建立小鼠卵巢早衰模型的研究

目的:探讨利用不同浓度气态甲醛建立小鼠卵巢早衰模型的方法及可行性。方法:将40只性成熟SPF级雌性昆明小鼠随机分为空白对照组和3个不同浓度(0.1mg/m3、1.0mg/m3、10mg/m3)气态甲醛染毒组(模型组)。对照组给予吸入经过滤的新鲜空气,模型组采用不同浓度气态甲醛动态吸入式染毒,6h/d,连续14d,观察气态甲醛对小鼠一般状态、动情周期、性激素水平及卵巢脏器系数的影响。结果:不同浓度气态甲醛染毒均可使小鼠一般状态差,模型组小鼠动情周期延长且不规则,血清E2水平明显降低,FSH、LH及FSH/LH水平明显升高,卵巢脏器系数显著降低,与对照组比较均有明显差异(P<0.05)。结论:利用10mg/m3浓度气态甲醛慢性染毒建立小鼠卵巢早衰模型是可行的。     

Anti-arthritic and disease modifying activity of Terminalia chebula Retz. in experimental models

Objective This study evaluates the anti‐arthritic effect of Terminalia chebula hydroalcoholic extract (TCHE) in experimental models and attempts to correlate the effect of treatment on macrophage‐derived pro‐inflammatory cytokine expression and extent of disease activity. Methods Arthritis was induced in rats by subplantar administration of either formaldehyde or complete Freund's adjuvant (CFA). Joint size was measured at regular intervals by using a micrometer screw gauge. Serum and ankle joints of rats immunized with CFA were collected and subjected to ELISA for estimation of TNF‐α level and immuno‐histochemistry for detection of IL‐1β, IL‐6 and TNF‐R1, respectively. An acute and 28‐day oral toxicity study was carried out to evaluate the safety of the test drug. Key findings TCHE produced a significant inhibition of joint swelling as compared with control in both formaldehyde‐induced and CFA‐induced arthritis. TCHE treatment also reduced serum TNF‐α level and synovial expression of TNF‐R1, IL‐6 and IL‐1β. Results of acute toxicity study showed that the oral LD50 of TCHE was >2000 mg/kg. Chronic administration also did not produce any significant physiological changes as compared with normal rats. Conclusion Results indicate that the anti‐arthritic activity of TCHE was at least in part due to its modulatory effect on pro‐inflammatory cytokine expression in the synovium. We believe that TCHE has the potential to be used as a disease‐modifying agent in treatment of rheumatoid arthritis.     

Airborne environmental injuries and human health

The concept that the environment in which we live can have detrimental effects on our health has existed for centuries. Obvious examples of substances that can cause human diseases include infectious agents, poisons, chemicals and other noxious agents, drugs, and physical stimuli such as bright lights and loud sounds. Some less obvious agents can include allergens, nontangible agents such as colorless, odorless gases and aerosolized toxins. In recent decades, humans have developed various new materials and compounds. Additionally, we are now producing known compounds, and even naturally occurring substances, in vastly increased amounts. Many of these substances are generally believedto threaten the health of our environment. However, there is also a considerable amount of hype and exaggeration regarding some of these agents (e.g., mold) that is unsubstantiated. This article extensively reviews the data on a large number of airborne-related illnesses and attempted to place scientific reality in the context of clinical medicine.     

Haemodialysis-associated anaphylactic and anaphylactoid reactions

Anaphylactic and anaphylactoid reactions related to haemodialysis have been increasingly described for almost 3 decades. The majority of these cases used to occur with ethylene oxide sterilized, and complement-activating cellulose membranes. However, a considerable number of publications have focused on polyacrylonitrile AN69 high flux membranes, angiotensin converting enzyme inhibitors and iron as other important causes of potentially severe haemodialysis-related anaphylactoid reactions. Clinical manifestations vary considerably and generally do not allow differentiation between IgE-mediated anaphylaxis and anaphylactoid reactions (e.g. from nonspecific mediator release). Successful management of these patients requires multidisciplinary approach and involves prompt recognition and treatment by the attending physician, and identification of the offending agent(s) with subsequent avoidance of the incriminated compound(s). This review focuses on some major causes of anaphylactoid and anaphylactic reactions during haemodialysis. Special consideration is given to the therapeutic and diagnostic approach.     

Editorial

This is the second part of a review article on formaldehyde‐releasers used as durable press chemical finishes (DPCF) in textiles. The early finishes contained large amounts of free formaldehyde, which led to many cases of allergic contact dermatitis to clothes in the 1950s and 1960s. Currently, most finishes are based on modified dimethylol dihydroxyethyleneurea, which releases less formaldehyde. Nevertheless, recent studies in the United States and Israel have identified patients reacting to DPCF, considered to have allergic contact reactions to clothes, either from formaldehyde released by the DPCF therein or from the DPCF per se (in patients negative to formaldehyde). However, all studies had some weaknesses in design or interpretation and in not a single case has the clinical relevance been proven. The amount of free formaldehyde in most garments will likely be below the threshold for the elicitation of dermatitis for all but the most sensitive patients. The amount of free cyclized urea DPCF in clothes is unlikely to be high enough to cause sensitization. Patch test reactions to formaldehyde‐releasing DPCF will in most cases represent a reaction to formaldehyde released from the test material.     

Formaldehyde exposure impairs the function and differentiation of NK cells

We investigated the cytotoxic effects of formaldehyde (FA) on lymphocytes. FA-exposed mice showed a profound reduction not only in the number of natural killer (NK) cells but also in the expression of NK cell-specific receptors, but these mice did not exhibit decreases in the numbers of T or B lymphocytes. FA exposure also induced decreases in NK cytolytic activity and in the expression of NK cell-associated genes, such as IFN-γ, perforin and CD122. To determine the effect of FA on tumorigenicity, C57BL/6 mice were subcutaneously injected with B16F10 melanoma cells after FA exposure. The mass of the B16F10 tumor and the concentration of extravascular polymorphonuclear leukocytes were greater than those in unexposed tumor-bearing control mice. The number and cytolytic activity of NK cells were also reduced in B16F10 tumor-bearing mice exposed to FA. To determine how FA reduces the NK cell number, NK precursor (pNK) cells were treated with FA, and the differentiation status of the NK cells was analyzed. NK cell differentiation was impaired by FA treatment in a concentration-dependent manner. These findings indicate that FA exposure may promote tumor progression by impairing NK cell function and differentiation.     

Preparation of cross-linked chitosan microspheres by spray drying: Effect of cross-linking agent on the properties of spray dried microspheres

Chitosan microspheres cross-linked with three different cross-linking agents viz, tripolyphosphate (TPP), formaldehyde (FA) and gluteraldehyde (GA) have been prepared by spray drying technique. The influence of these cross-linking agents on the properties of spray dried chitosan microspheres was extensively investigated. The particle size and encapsulation efficiencies of thus prepared chitosan microspheres ranged mainly between 4.1–4.7?µm and 95.12–99.17%, respectively. Surface morphology, % erosion, % water uptake and drug release properties of the spray dried chitosan microspheres was remarkably influenced by the type (chemical or ionic) and extent (1 or 2%?w/w) of cross-linking agents. Spray dried chitosan microspheres cross-linked with TPP exhibited higher swelling capacity, % water uptake, % erosion and drug release rate at both the cross-linking extent (1 and 2%?w/w) when compared to those cross-linked with FA and GA. The sphericity and surface smoothness of the spray dried chitosan microspheres was lost when the cross-linking extent was increased from 1 to 2%?w/w. Release rate of the drug from spray dried chitosan microspheres decreased when the cross-linking extent was increased from 1 to 2%?w/w. The physical state of the drug in chitosan-TPP, chitosan-FA and chitosan-GA matrices was confirmed by the X-ray diffraction (XRD) study and found that the drug remains in a crystalline state even after its encapsulation. Release of the drug from chitosan-TPP, chitosan-FA and chitosan-GA matrices followed Fick's law of diffusion.     

生血丸对甲醛致小鼠细胞损伤的影响

目的 探讨生血丸对甲醛致小鼠肺、肝、脾、骨髓细胞及外周血淋巴细胞损伤的预防与修复作用及机制。方法 将小鼠随机分5组：对照组、生血丸预防给药组（预防组）、生血丸治疗给药组（治疗组）、模型1组（对应治疗组）、模型2组（对应预防组）。ELISA法检测肺、肝、脾组织中羟自由基、超氧阴离子自由基、鸟氨酸脱羧酶（ODC）的活性。高倍镜下观察骨髓细胞及外周血淋巴细胞的微核率。结果 2个模型组小鼠肺、肝、脾组织内羟自由基、超氧阴离子自由基、ODC活性比对照组显著增加,骨髓细胞及外周血淋巴细胞的微核率显著增加（P<0.05）;生血丸预防组及治疗组小鼠的肺、肝、脾组织中羟自由基、超氧阴离子及ODC的活性与对应模型组比较显著降低（P<0.05）,外周血淋巴细胞的微核率显著降低（P<0.05）。结论 生血丸能有效预防和改善小鼠肺、肝、脾、骨髓细胞及外周血淋巴细胞由于甲醛造成的损伤。     

2009-2011年广州市番禺区水产品污染状况分析

目的分析番禺区水产品污染状况,为食品安全监管提供依据。方法在番禺区各水产交易市场、肉菜综合市场和餐饮单位随机采集鲜活鱼（淡水鱼、海水鱼）、虾蟹、贝类、冰鲜、生吃水产品等水产品进行重金属、抗生素、农药、致病菌、肝吸虫等项目检测。结果各类水产品均存在镉超标,总超标率为5.2%。虾蟹类镉平均含量为0.516mg/kg,最高含量为14.300mg/kg;贝类、海水鱼、淡水鱼的镉超标率分别为4.5%、3.7%、2.5%。铅合格率为99.5%,汞和无机砷均未超标。部分水产品中检出四环素、土霉素、金霉素超标,超标率在8.3%～14.3%。各类水产品中六六六、DDT的含量均未超标。冰鲜水产品中甲醛合格率为98.1%。222份水产品中副溶血性弧菌检出率为18.5%（41/222）,其中检出率最高的是虾蟹类为41.7%,贝类为33.3%。淡水鱼、海水鱼、虾蟹类、贝类等4类水产品的副溶血性弧菌检出率差异有统计学意义（P〈0.05）,淡水鱼与海水鱼的副溶血性弧菌检出率差异无统计学意义（P〉0.05）。所有样品均未检出沙门菌和霍乱弧菌。生吃水产品未检出致病菌和肝吸虫。结论番禺区水产品镉污染情况较为突出,水产品中副溶血性弧菌检出率较高,水产养殖和销售中存在不按规定使用抗生素的情况。