以重组蛋白为抗原的ELISA法检测旋毛虫抗体

目的 寻求特异性强、敏感性高的旋毛虫病诊断抗原。 方法 以旋毛虫新生幼虫期特异性T668基因在E.coli高效表达的重组蛋白为抗原，分别以兔、猪和健康者血清及旋毛虫病阳性血清为一抗，以辣根过氧化物酶（HRP）标记的山羊抗兔IgG、山羊抗猪IgG和山羊抗人IgG为二抗，建立检测旋毛虫抗体的间接ELISA方法，并以旋毛虫肌幼虫排泄?鄄分泌（ES）抗原作为检测对照。 结果 以T668重组蛋白为抗原，对兔、猪和人旋毛虫病血清进行检测，阳性检出率为100 ％，且敏感性高（0.016 μg / 孔），与ES抗原检测结果完全一致。 结论 T668重组抗原有望替代ES抗原检测旋毛虫抗体。     

Midkine is highly expressed in neuroblastoma tissues

Purpose  Neuroblastoma (NBL) is a tumor from neural crest cells, and is the most frequent solid tumor in children. Midkine (MK) is a pleiotropin analogon, which is frequently expressed in neuronal and epithelial tumors and is a marker for a poor clinical outcome. The aims of this study were to assess MK expression in NBL and investigate the correlation with clinical outcome. Methods  Fifty-six specimens of NBL were stained for MK on a tissue microarray by immunohistochemistry (IHC). Fresh frozen tumor tissues were used for RNA isolation, and RT-PCR analysis for MK-mRNA expression was performed. Survival data, risk factors and disease stages were correlated with MK status assessed by IHC and RT-PCR analysis. Results  MK-mRNA expression was found in the majority of the tumor tissues (75%), whereas MK protein could be detected only in 46% of the NBL by IHC. No correlation of MK status with survival, risk factors or disease stage was observed. Conclusion  A majority of NBL express MK-mRNA, whereas not all MK mRNA positive tumors showed also a positive MK IHC staining. The high expression of MK-mRNA expression might present a promising target for new adenovirus-based gene therapeutic approaches for the treatment of NBL.     

TRPV1 receptors modulate retinal development

We investigated the possible participation of TRPV1 channels in retinal apoptosis and overall development. Retinas from newborn, male albino rats were treated in vitro with capsazepine, a TRPV1 antagonist. The expression of cell cycle markers was not changed after TRPV1 blockade, whereas capsazepine reduced the number of apoptotic cells throughout the retina,increased ERK1/2 and p38 phosphorylation and slightly reduced JNK phosphorylation. The expression of BAD, Bcl-2, as well as integral and cleaved capsase-3 were similar in all experimental conditions. Newborn rats were kept for 2 months after receiving high doses of capsazepine. In their retinas, calbindin and parvalbumin protein levels were upregulated, but only the number of amacrine-like, parvalbumin-positive cells was increased. The numbers of calretinin, calbindin, ChAT, vimentin, PKC-alpha and GABA-positive cells were similar in both conditions. Protein expression of synapsin Ib was also increased in the retinas of capsazepine-treated rats. Calretinin, vimentin, GFAP, synapsin Ia, synaptophysin and light neurofilament protein levels were not changed when compared to control values.Our results indicate that TRPV1 channels play a role in the control of the early apoptosis that occur during retinal development, which might be dependent on MAPK signaling. Moreover, it seems that TRPV1 function might be important for neuronal and synaptic maturation in the retina.     

Glycosidases of Trichinella spiralis

The exoglycosidases beta-N-acetyl-D-glucosaminidase, beta-N-acetyl-D-galactosaminidase, alpha-1-fucosidase, alpha-D-glucosidase and alpha-D-mannosidase, and a non-specific acid phosphohydrolase are present at high levels in extracts of adult and muscle-stage (L1) Trichinella spiralis and at lower (5-30-fold) levels in extracts of the newborn larvae. The enzyme activities from the L1 extract were characterized. All displayed maximum activity at acid pH. beta-N-acetyl-D-glucosaminidase and beta-N-acetyl-D-galactosaminidase had identical molecular weights (110 000), pH optima (5.0), and isoelectric points (5.7) indicating that both of these substrate specificities reside in the same protein molecule. alpha-1-Fucosidase had a molecular weight of 125 000 and exhibited two pH optima (5.0 and 6.0) and four isoelectric points (5.9, 6.4, 6.7 and 7.1) indicating its presence in multiple molecular forms. alpha-D-Glucosidase had a molecular weight of 85 000, a pH optimum of 6.0 and an isoelectric point of 5.2; alpha-D-mannosidase had a molecular weight of 192 000, a pH optimum of 6.0 and an isoelectric point of 4.5; and acid phosphatase had a molecular weight of 81 000, a pH optimum of 6.0 and two isoelectric points (4.8 and 5.9) indicating its existence in two molecular forms. The same glycosidases and acid phosphatase were detected also in culture fluids collected after 15-20-h incubation of both L1 and adults. As in the worm extracts, beta-N-acetyl-D-glucosaminidase was present in these culture fluids at the highest activity with acid phosphatase present at the next highest activity.     

Trichinella spiralis infection rapidly induces lung inflammatory response: the lung as the site of helminthocytotoxic activity

In the present work, we studied the kinetics of the appearance of different immunological parameters in the lungs during the intestinal phase of infection with Trichinella spiralis. We also evaluated the lung's role in the retention and death of this helminth in its migratory stage. To study these parameters, we used lung extracts, lung cell suspensions and rat lung tissue sections.During the intestinal phase of infection (days 0-13 post-infection, p.i.), an inflammatory response is elicited in the lungs, which reflects humoral, cellular and functional changes. These changes included an increased number of mast cells and eosinophils and the local production of IL-4, IL-5, IL-10, TNFα, IFNγ, IL-13, CCL11 and CCL28. We found hyperplasia of the bronchus-associated lymphoid tissue (BALT). Total and specific IgA, IgE, IgG1 and IgG2a were detected locally. The retention of the migratory larvae in the lung, together with the ex vivo cytotoxic capacity of the lung cells and antibodies present in the lung extracts, suggested that the lung was one of the immune defense organs against the pathogen's migration stage.     

A major change in surface antigens during the maturation of newborn larvae of Trichinella spiralis

Newborn larvae of Trichinella spiralis were collected for 30 min from female worms in culture, incubated in vitro for various times up to 18 h, and surface-labelled with iodine. The detergent-solubilised products were examined by SDS-polyacrylamide gel electrophoresis. At time periods up to 6 h these larvae expressed only one M_r 64 000 iodine-labelled surface protein. Some time between 6 h and 18 h a further three components (apparent M_r 58 000, 34 000 and 32 000) became accessible to surface labelling. All four of these components are antigenic in that they can be immunoprecipitated with T. spiralis immune sera. Tryptic peptide analysis revealed that the 32 and 34 kDa antigens were structurally very similar, but the 58 and 64 kDa proteins differed from each other and the 32–34 kDa pair. Thus T. spiralis not only undergoes a total change in surface antigens between moults, but also major changes in surface antigen expression within one stage.     

Metastatic 4S neuroblastoma with excellent outcome in Saudi cancer center

Objectives:To retrospectively review a small series of infant neuroblastoma (NBL) in a single Saudi medical institution over 10 years, including their presentation, management, and outcomes.Methods:Fifty-three subjects aged 0 to 14 years with previously untreated NBL who were diagnosed and treated at Princess Nora Oncology Center, King Abdulaziz Medical City (KAMC), Jeddah, Saudi Arabia, between 2010 and 2019. Six infants (11.3%) had stage 4S characteristics.Results:The median age at diagnosis was 3 months (range 52 days - 4 months). Biopsies confirmed that the adrenal gland was the primary tumor site for 3 patients, while the other 2 had retroperitoneal sites. Four patients had favorable histology, and one had unfavorable histology. All patients had liver metastasis, and no bone marrow or skin metastasis was recorded. All patients received chemotherapy except one, and all survived with no disease progression at a median follow up to 5 years.Conclusion:Our data confirm that NBL-4S is a curable cancer, especially with early recognition and intervention. Chemotherapy is the first-line treatment for symptomatic patients. Unless the condition is life threatening, radiotherapy is not indicated. Surgical resection may be indicated in younger infants with localized tumors and favorable biology, but otherwise, it is not usually indicated for residual cases.     

Trichinella spiralis: the infectivity of synchronous newborn larvae of different ages inoculated intraocularly

Trichinella spiralis infection results in the transformation of muscle cells into a new, non-muscular cell called the nurse cell, and the nurse cell-muscle larva complex is finally created. To investigate whether T. spiralis infectivity is NBL age-dependent, five groups of synchronous newborn larvae (sNBL) were obtained at 1, 9, 24, 48, and 72 h of age and were inoculated into mice by intravenous injection into the retro-orbital venous plexus. When both “young” groups of sNBL (1 and 9 h old) were injected, the highest number of larvae were capable of infecting the muscle cells. The highest infectivity of 80.0% was observed for 9-h-old sNBL. In older sNBL the infectivity gradually decreased; thus, for 72-h-old sNBL the lowest level – 0.1% – was detected. Therefore, an “age limit” for NBL infectivity in the present study was precisely determined. Received: 14 September 1998 / Accepted: 15 October 1998