High Tregs and systemic IL-10 expressions linked to the absence of sheath antibodies in lymphatic filariasis: implications on the persistence of residual infection

The persistence of residual infection is one of the major factors in failure of the Global Programme to Eliminate Lymphatic Filariasis (GPELF). The present study aims to explore the status of sheath antibody and regulatory T cells (Tregs) known to play key roles in clearance of parasite and patent filarial infection, in individuals with residual infection after MDA. A total of 61 microfilaremic (Mf) individuals were followed up after at least 6 rounds of MDA. Infection status of subjects was assessed through the detection of Mf and circulating filarial antigen (CFA). Antibodies to Mf sheath were determined by immuno-peroxidase assay (IPA). The expression of Tregs was measured by a flow cytometer. IL-10 and IFN-γ were evaluated using the commercially available ELISA kit. The sheath antibody was present in subjects who have cleared both Mf and CFA and absent in individuals who were found to be Mf /CFA positive. Further individuals carrying infection have significantly high levels of Tregs and IL-10. A positive correlation was observed between Tregs, IL-10, and CFA in infected individuals. In contrast, a negative correlation was observed between IFN-γ and IL-10 in both infected and uninfected subjects. Our study reveals that the absence of a sheath antibody and a high level of Tregs and IL-10 are the hallmarks of the persistence of residual filarial infection.

     

In utero sensitization modulates IgG isotype,IFN‐γ and IL‐10 responses of neonates in bancroftian filariasis

In utero exposure has been considered as a risk factor for filarial infection. To evaluate the influence of maternal infection on filarial‐specific IgG subclass response in neonates and their correlation with plasma levels IL‐10 and interferon‐γ, 145 pairs of mothers and their respective cord bloods were examined. Transplacental transfer of circulating filarial antigen (CFA) was observed in 34·8% cord bloods from CFA positive mothers. Filarial‐specific IgG1, IgG2 and IgG4 responses of cord bloods were found to be positively correlated with CFA of mothers. In contrast, IgG3 responses negatively correlated with CFA of mothers. The % of similarity of recognition pattern in the cord blood with maternal blood was high for IgG3 response than IgG4 in all three groups. An increased levels of IL‐10 and decreased levels of interferon gamma (IFN‐γ) were observed in cord blood of infected mothers. Interferon gamma was positively correlated with IgG3 and negatively correlated with IgG4 level. On the other hand, IL‐10 was positively correlated with IgG4 and CFA, indicating that cytokines may play a role in modulating the immune responses in cord bloods of sensitized foetus. The findings of the study reveal that in utero tolerance or sensitization may influence the filarial‐specific immunity to infection in neonates.     

Bancroftian filariasis: circulating B‐1 cells decreased in microfilaria carriers and correlate with immunoglobulin M levels

B‐1 cells play an important role in the outcome of infection in schistosomiasis, pneumonia and experimental filariasis. However, no information exists regarding status of B‐1 cells in clinical manifestations of human filariasis. We investigated the levels of B‐1 cells from the total B cells by flow cytometry. Significantly low levels of B‐1 cells and IgM antibodies were detected against a wide variety of autoantigens in microfilariae carriers as compared to endemic controls and patients with chronic pathology. A positive correlation was found between IgM antibodies to actin and ss‐DNA. Absorption of plasma with soluble actin, myosin and lipopolysaccharides (LPS) resulted in significant removal of antifilarial antibodies. Affinity‐purified anti‐ss‐DNA antibodies were found to be reactive to filarial antigens and various autoantigens. Further, a positive correlation was found between polyreactive antibodies and B‐1 cells in filarial‐infected human subjects. After antifilarial treatment, levels of IgM antibodies to ss‐DNA, actin, LPS and filarial antigen increased significantly indicating a role of polyreactive naturally occurring antibodies in filarial infection. Our findings add to the existing evidence that the B‐cell defect in BALB.Xid mice account for susceptibility to murine filarial infection and indicate an important role for these antibodies in providing host protection against filarial infection.     

Transient cortical blindness in fat embolism syndrome—a diagnostic enigma

Fat embolism syndrome (FES) is a serious life-threatening manifestation of the fat embolism phenomenon characterized by Bergman’s triad of dyspnea, petechiae and mental confusion. While fat embolization into systemic circulation is common, FES occurs in a meagre 0.05%e3% of patients having isolated long bone fractures. Though visual symptoms are commonly attributed to fat embolism retinopathy and is a later occurrence, it may not always be the case. Cortical blindness has been seldom reported in association with FES, and less so as a presenting complaint. Furthermore, no previous literature has described the same in context of an isolated tibia fracture. We report a 20-year-old gentleman with an isolated right tibia shaft fracture who developed sudden onset diminution of vision in both eyes less than 24 h following trauma with no other complaints. Lack of any remarkable ophthalmoscopic findings or other symptoms left us with a diagnostic conundrum. He later went on to develop altered mentation, hypoxia and generalized tonic-clonic seizures with subsequent MRI revealing multiple cerebral fat emboli also involving both occipital lobes. Supportive measures were instituted and his general condition as well as vision gradually improved following which he underwent plate fixation of the fracture under spinal anaesthesia. The perioperative period was uneventful and he was discharged following staple removal. At one month of follow-up, the patient had no residual visual field defects or neurological deficits. Though FES is rare among isolated tibia fractures, this clinical catastrophe may strike in any unsuspected setting thereby warranting a high index of suspicion to ensure early diagnosis and improved patient outcomes.     

A candidate metastasis-associated DNA marker for ductal mammary carcinoma

Background

Molecular genetic markers to identify the 13% lymph node-negative mammary carcinomas that are prone to develop metastases would clearly be of considerable value in indicating those cases in need of early aggressive therapy.

Methods

Representational difference analysis was used in an attempt to identify genetic alterations related to breast cancer metastasis by comparing genomic DNA from microdissected normal cells and from metastatic cells of ductal breast carcinoma patients.

Results

Representational difference analysis products yielded 10 unique metastasis-associated DNA sequences (MADS), i.e. products apparently lost in metastatic cell DNA. Of these sequences, MADS-IX was found to be lost in the transition from primary to metastasis in two out of five ductal breast carcinoma cases. This sequence was localized on chromosome 10q21 by radiation hybrid mapping and fluorescence in situ hybridization. The PTEN gene, which is also located on chromosome 10q, was detected to be present by PCR in all five cases. On the contrary, a breast carcinoma cell line, HCC-1937, which has homozygous loss of a region encompassing the PTEN gene, showed the presence of MADS-IX. PCR screening of three additional breast carcinoma cell lines with known losses in specific chromosomal regions also showed the presence of MADS-IX.

Conclusion

These data suggest that MADS-IX possibly is part of a novel candidate metastasis-associated gene located close to the PTEN gene on chromosome 10q. The first set of PCR screening in five patient samples indicates that it could be used as a molecular marker for ductal mammary metastasis.     

血红素氧化酶1基因多态和冠状动脉旁路移植后的炎症反应

背景:血红素氧化酶1是降解血红素生成胆红素、亚铁及一氧化碳过程的限速酶,具有重要的抗炎功能,其启动子部位GT重复序列的多态性可使该基因表达的水平不同,重复序列较短者基因转录活性较高.目的:观察冠状动脉旁路移植术后炎性标记物白细胞介素6,C-反应蛋白及纤维蛋白原的水平及其相关性,探讨血红素氧化酶1基因变量对它们的影响.设计、时间及地点:观察性试验,于2003年在英国伦敦大学学院心血管遗传病学中心完成.对象:220例符合入选条件的行冠状动脉旁路移植术的患者,男179例,女41例,年龄(63.34±9.64)岁.方法:PCR方法和DNA测序仪分析其血红素氧化酶1基因启动子部位GT重复序列的长短;于手术前及术后6,24,48,72,96,120 h分别测白细胞介素6、C-反应蛋白和纤维蛋白原水平.主要观察指标:血红素氧化酶1基因启动子部位GT重复序列的长短;手术前及术后不同时间白细胞介素6、C-反应蛋白和纤维蛋白原水平.结果:术前白细胞介素6水平与C-反应蛋白及纤维蛋白原值显著相关(r=0.48,P＜0.000 1;r=0.41,P＜0.000 1),术后3者均显著升高,白细胞介素6峰质量浓度与C-反应蛋白峰质量浓度显著相关(r=0.34,P=0.0009),但与纤维蛋白原峰值无明显相关性(r=0.15,P=0.13).术前C-反应蛋白值在血红素氧化酶1各基因组间存在明显差异,长GT重复序列者比短GT重复序列携带者高(3.76±0.79),(2.07±0.17)mg/L,P=0.013];术后则各基因型组间水平相似.结论:炎症标志物的水平间存在相关性,血红素氧化酶1基因多态只与术前的基础C-反应蛋白和纤维蛋白原值有关,提示其可能只影响疾病的慢性炎症状态,从而影响炎性疾病的发生,而非急性炎症反应.     

Vertebral osteomyelitis after a closed fracture of the spine. A case report

A case of spinal tuberculosis after a closed fracture, differing from the usual tuberculous spondylitis in that trauma appeared to have predisposed the affected vertebrae to haematogenous infection, is described.     

Aluminium induced oxidative stress and DNA damage in root cells of Allium cepa L

Aluminium (Al) was evaluated for induction of oxidative stress and DNA damage employing the growing roots of Allium cepa L. as the assay system. Intact roots of A. cepa were treated with different concentrations, 0, 1, 10, 50, 100, or 200 μM of aluminium chloride, at pH 4.5 for 4 h (or 2 h for comet assay) at room temperature, 25±1 °C. Following treatment the parameters investigated in root tissue were Al-uptake, cell death, extra cellular generation of reactive oxygen intermediates (ROI), viz. O₂⁻, H₂O₂ and OH, lipid peroxidation, protein oxidation, activities of antioxidant enzymes namely catalase (CAT), superoxide dismutase (SOD), guaiacol peroxidase (GPX), ascorbate peroxidase (APX); and DNA damage, assessed by comet assay. The findings indicated that Al triggered generation of extra-cellular ROI following a dose-response. Through application of specific enzyme inhibitors it was demonstrated that extra-cellular generation of ROI was primarily due to the activity of cell wall bound NADH-PX. Generation of ROI in root tissue as well as cell death was better correlated to the levels of root Al-uptake rather than to the concentrations of Al in ambient experimental solutions. Induction of lipid peroxidation and protein oxidation by Al were statistically significant. Whereas Al inhibited CAT activity, enhanced SOD, GPX and APX activities significantly; that followed dose-response. Comet assay provided evidence that Al induced DNA damage in a range of concentrations 50–200 μM, which was comparable to that induced by ethylmethane sulfonate (EMS), an alkylating mutagen served as the positive control. The findings provided evidence that Al comparable to biotic stress induced oxidative burst at the cell surface through up- or down-regulation of some of the key enzymes of oxidative metabolism ultimately resulting in oxidative stress leading to DNA damage and cell death in root cells of A. cepa.