A sensitive in situ ELISA for quantitative measurements of cytokines and antibodies secreted by culture lymphocytes

Cytokines are usually measured using ELISA and ELISPOT. We have developed an in situ ELISA by combining the advantages of the highly sensitive ELISPOT and the quantitative conventional ELISA techniques to measure cytokines and antibodies secreted by culture lymphocytes. In this assay, lymphocytes were cultured on ELISA plates pre-coated with either a special antigen or mAbs against IL-4, IFN-gamma. The caprtured lymphokines or immunoglobulins were subsequently measured by conventional ELISA procedures. As a comparison, a conventional ELISA was carried out in parallel. The in situ ELISA measured a 5-fold increase in antigen-stimulated IL-4 and IFN-gamma, compared to the conventional ELISA. It also rquired 10,000 times fewer lymphocytes to produce a detectable level of antigen-specific antibodies than the conventional ELISA. We conclude that the in situ ELISA is much more sensitive than a conventional ELISA and less costly and easier to perform than ELISPOT, providing a useful tool to quantitatively measure cell-secreted molecules.

Anaphylaxis from topical bovine thrombin (Thrombostat) during haemodialysis and evaluation of sensitization among a dialysis population

BACKGROUND

Topical bovine thrombin (TBT) is used as a topical haemostatic agent in haemodialysis (HD) units and for surgical procedures. It has caused allergic reactions during surgical procedures, but no previous cases have been reported with dialysis usage.

OBJECTIVE

A case is reported of anaphylaxis due to TBT in an HD patient. This led to a determination of whether HD patients exposed to TBT develop specific IgE and IgG antibodies to TBT and an assessment of the frequency of allergic symptoms in HD patients as compared with peritoneal dialysis (PD) patients.

METHODS

A cross-sectional study of 100 HD and 52 PD patients was performed using a questionnaire to determine allergic symptoms. An ELISA assay was developed to determine TBT-specific IgE and IgG serum antibodies among HD patients. HD patients without TBT exposure and age- and gender-matched blood donors served as controls.

RESULTS

Allergic symptoms temporally related to dialysis reported by a questionnaire were significantly more frequent for HD patients than for PD patients: rhinoconjuctivitis 11% vs. 2%, asthma symptoms 20% vs. 6%, urticaria 23% vs. 8% (P values <0.05). Positive TBT-specific IgE and IgG antibodies were more frequent among 65 exposed HD patients (28% for IgE and 26% for IgG) than for controls (4% and 9%), P<0.05.

CONCLUSIONS

Results indicate the potential for sensitization and clinical allergic responses to beef thrombin when used for haemostasis in HD and suggest that other haemostatic methods should be considered.

Electrochemistry and spectroscopy study on the interaction of microperoxidase-11 with lipid membrane

The interaction of microperoxidase-11 (MP11) with cationic lipid vesicles of didodecyldimethylammonium bromide (DDAB) induces an alpha-helical conformation from random coil conformations in solution and this change then makes heme macrocycle more distorted. DDAB-induced MP11 conformations were investigated by cyclic votammetry (CV), circular dichroism (CD) and UV-vis spectrometry. All results indicate that the binding of MP11 in solution to DDAB vesicles and the ordered structure formation are driven by mostly electrostatic interaction between negatively charged residues in the undecapeptide and positively charged lipid headgroups on the membrane surface. Upon binding to DDAB, its half-peak potential was also changed. The mechanism of the interaction between MP11 and DDAB was also discussed.

Expression, purification, characterization and clinical relevance of rAed a 1--a 68-kDa recombinant mosquito Aedes aegypti salivary allergen

Accurate diagnosis of mosquito allergy has been precluded by the difficulty of obtaining salivary allergens. In this study, we expressed, purified, characterized and investigated the clinical relevance of a recombinant Aedes aegypti salivary allergen, rAed a 1. Two cDNA segments were ligated together to form the full-length Aed a 1 gene. rAed a 1 was expressed using a baculovirus/insect cell system, and purified using a combination of anion-exchange and gel-filtration chromatography. The purified rAed a 1 bound to human IgE, as detected by ELISA, ELISA inhibition tests and immunoblot analyses. Epicutaneous tests with rAed a 1 and a commercial whole-body AE: aegypti extract, and AE: aegypti bite tests were performed in 48 subjects. Nine of 31 (29%) of the subjects with positive immediate bite tests also had a positive rAed a 1 immediate skin reaction and 32% had an positive immediate test to the commercial extract. Six of 33 (18%) of the subjects with positive delayed bite tests also had a positive rAed a 1 delayed skin reaction and 6% had a positive delayed test to the commercial extract. Furthermore, rAed a 1-induced flare sizes significantly correlated with mosquito bite-induced flare sizes. None of the subjects with negative bite tests had a positive skin test to rAed a 1 or to commercial extract. We conclude that the rAed a 1 has identical antigenicity and biological activity to native Aed a 1, can be used in the in vitro and in vivo diagnosis of mosquito allergy, and is more sensitive than mosquito whole-body extract for detecting delayed skin reactions.

[A study of bone development and metabolism in childhood]

OBJECTIVE

To explore the regularity of bone development and metabolism in childhood.

METHODS

A survey was made to collect and analyze the data on bone biochemistry, the density of lumbar vertebrae and the X-ray examination of calcaneus in 224 healthy children aged 3-15 years in the urban area of Chengdu.

RESULTS

Comparative analysis of serum and urine calcium and phosphate concentrations showed no significant difference between the age groups. The serum alkaline phosphatase (ALP) and bone alkaline phosphatase (BALP) were found to increase with age and reach their peak values in children aged 7-12 years, and their values were significantly higher than that of adults (P < 0.05). The density of lumbar vertebrae and the trabecular bone of calcanesus also developed with age.

CONCLUSION

The measurements of the bone biochemistry, bone density and the trabecular bone of calcaneus which reflect the bone development and metabolism have their special regularity in childhood. The criteria in use for adulthood is not fit for the evaluation in childhood. The data obtained can be used in clinical diagnosis and treatment of the bone metabolic diseases of children.

Cooperative folding of the isolated alpha-helical domain of hen egg-white lysozyme

Proteins in the alpha-lactalbumin and c-type lysozyme family have been studied extensively as model systems in protein folding. Early formation of the alpha-helical domain is observed in both alpha-lactalbumin and c-type lysozyme; however, the details of the kinetic folding pathways are significantly different. The major folding intermediate of hen egg-white lysozyme has a cooperatively formed tertiary structure, whereas the intermediate of alpha-lactalbumin exhibits the characteristics of a molten globule. In this study, we have designed and constructed an isolated alpha-helical domain of hen egg-white lysozyme, called Lyso-alpha, as a model of the lysozyme folding intermediate that is stable at equilibrium. Disulfide-exchange studies show that under native conditions, the cysteine residues in Lyso-alpha prefer to form the same set of disulfide bonds as in the alpha-helical domain of full-length lysozyme. Under denaturing conditions, formation of the nearest-neighbor disulfide bonds is strongly preferred. In contrast to the isolated alpha-helical domain of alpha-lactalbumin, Lyso-alpha with two native disulfide bonds exhibits a well-defined tertiary structure, as indicated by cooperative thermal unfolding and a well-dispersed NMR spectrum. Thus, the determinants for formation of the cooperative side-chain interactions are located mainly in the alpha-helical domain. Our studies suggest that the difference in kinetic folding pathways between alpha-lactalbumin and lysozyme can be explained by the difference in packing density between secondary structural elements and support the hypothesis that the structured regions in a protein folding intermediate may correspond to regions that can fold independently.

Molecular characterization of subunit 6 of the COP9 signalosome and its role in multifaceted developmental processes in Arabidopsis

The COP9 signalosome is a highly conserved protein complex initially identified as a repressor of photomorphogenesis. Here, we report that subunit 6 of the Arabidopsis COP9 signalosome is encoded by a family of two genes (CSN6A and CSN6B) located on chromosomes V and IV, respectively. The CSN6A and CSN6B proteins share 87% amino acid identity and contain a MPR1p and PAD1p N-terminal (MPN) domain at the N-terminal region. The CSN6 proteins share homology with CSN5 and belong to the Mov34 superfamily of proteins. CSN6 proteins present only in the complex form and coimmunoprecipitate with other known subunits of the COP9 signalosome. Partial loss-of-function strains of the COP9 signalosome created by antisense and cosuppression with CSN6A exhibit diverse developmental defects, including homeotic organ transformation, symmetric body organization, and organ boundary definition. Protein blot analysis revealed that the defective plants accumulate significant amounts of ubiquitinated proteins, supporting the conclusion that the COP9 signalosome regulates multifaceted developmental processes through its involvement in ubiquitin/proteasome-mediated protein degradation.

A role of Arabidopsis COP9 signalosome in multifaceted developmental processes revealed by the characterization of its subunit 3

The COP9 signalosome is a highly conserved eight-subunit protein complex initially defined as a repressor of photomorphogenic development in Arabidopsis. It has recently been suggested that the COP9 signalosome directly interacts and regulates SCF type E3 ligases, implying a key role in ubiquitin-proteasome mediated protein degradation. We report that Arabidopsis FUS11 gene encodes the subunit 3 of the COP9 signalosome (CSN3). The fus11 mutant is defective in the COP9 signalosome and accumulates significant amount of multi-ubiquitinated proteins. The same mutant is specifically impaired in the 26S proteasome-mediated degradation of HY5 but not PHYA, indicating a selective involvement in protein degradation. Reduction-of-function transgenic lines of CSN3 produced through gene co-suppression also accumulate multi-ubiquitinated proteins and exhibit diverse developmental defects. This result substantiates a hypothesis that the COP9 signalosome is involved in multifaceted developmental processes through regulating proteasome-mediated protein degradation.

[Analysis on the genotype of measles virus epidemic strains in Dongguan city, Guangdong province in 2000]

OBJECTIVE

To analyze the genotype of the measles virus epidemic strains in Dongguan according to the patients suffered measles in 2000.

METHODS

The saliva of 55 patients with acute measles symptoms were collected and detected with RT-PCR. The PCR products of the 5 samples were sequenced and analyzed with the software DNASTAR.

RESULTS

The positive detection rate was 87.3%, whereas the positive rate of anti MV-IgM in serum was only 70.9%. 68.8% of the saliva samples of patients with anti MV-IgM negative results showing MV RNA positive. The 293 bp fragment of N gene and 194 bp fragment of M gene were amplified from the vaccine virus and the specimens. The sequences of the epidemic strains were identical in both M gene and N gene.

CONCLUSION

These results suggested that the outbreak came from a single MV strain. The epidemic strain was obviously different from the standard strains discovered in other countries of the world (the deviation were 1.4%-11.7%) that might belong to H genotype.

[A method of desulfurization with calcium sulfite and it's mechanism]

Directing to the scaling problem lying in wet desulfurization with lime slurry, a method of desulfurization with calcium sulfite was proposed. Reaction mechanism and the effects of different conditions on desulfurization efficiency were studied. The optimum conditions were obtained, i.e. air velocity of 2.75 m/s in empty tower, L/G = 3.0 L/m3, solid content 6.7%, air temperature 31 degrees C, concentration inlet of SO2 1500 x 10(-6) and inlet suspension pH of 8.0. Under the conditions, the desulfurization efficiency was about 87%. The presented method theoretically and practically solved the scaling problems, which is a novel indirect lime-method with Ca-contained material as desulfurization agent.

[Expression of cell cycle associated proteins cyclin D1 and P16 in endometrial carcinoma and the correlation between their expression status]

OBJECTIVE

To study the expression of cell cycle associated proteins Cyclin D1, P16 in endometrial carcinoma and their correlation to clinical parameters, and to assess the correlation between their expression status.

METHODS

Immunohistochemical method was used to detect Cyclin D1 and P16 expressions in 64 cases of endometrial carcinoma.

RESULT

The positive rate of Cyclin D1 was 54.68%. The Cyclin D1 expression was significantly associated with FIGO stage (P < 0.05). The positive rate of P16 was 53.13% and its expression was related to age, histological grade and FIGO stage (P < 0.05). There was an inverse correlation between Cyclin D1 and P16, r = -0.4007 (P < 0.01).

CONCLUSION

Cyclin D1 and P16 had cooperative effect and may play an important role in the development and progression of endometrial carcinoma.

Hepatic artery angiography and embolization for hemobilia after hepatobiliary surgery

OBJECTIVE

To evaluate the effectiveness of hepatic angiography and embolization in the diagnosis and treatment of hemobilia after hepatobiliary surgery.

METHODS

Nine patients had upper gastrointestinal bleeding 7 days to 3 months after surgery. They underwent emergency hepatic artery angiography and were treated by embolization using Gelfoam particles only (8 patients) and Gelfoam particles plus microcoils (1 patient).

RESULTS

Hepatic artery angiography revealed hepatic artery pseudoaneurysms in 3 patients, diffuse hemorrhage of the hepatic artery branches in 3, right hepatic artery-bile duct fistulas in 2, and hepatic artery-small intestine fistula in 1. Hemobilia was controlled with embolization in 7 patients, of whom 1 had recurrent bleeding 1 day after treatment. During the follow-up, 3 patients died of multiple organ dysfunction syndrome. Two patients whose hemorrhage could not be controlled due to technical reasons died several days later.

CONCLUSION

When hemobilia after hepatobiliary surgery is suspected, patients should receive hepatic angiography as a first diagnostic procedure and be treated with minimally invasive procedure of selective embolization of the involved artery as soon as possible.

Determination of peripheral blood stem cells by the Sysmex SE-9500

The Sysmex SE-9500 automated haematology analyser provides an estimate of immature cells, referred to as 'haematopoietic progenitor cells' (HPC). The aim of this study was to evaluate the reliability and usefulness of the SE-9500 HPC parameter as compared with the CD34 + cell count and to determine whether the HPC count was of value in predicting the optimal harvesting time for peripheral blood stem cells (PBSC). Studies were performed on 112 samples from 21 patients with haematological malignancies and 13 healthy donors undergoing progenitor cell mobilisation. Coefficients of variation for the HPC count were 30%, 23.8%, 12.4% and 8.3% respectively for samples with low (4 x 106/l), medium (13 x 106/l), high (250 x 106/l) and very high (2413 x 106/l) counts. There was good linearity for HPC measurement in both peripheral blood (PB) and purified CD34 + cell suspensions (r > 0.995), and no detectable carryover was observed. There was an acceptable correlation between HPC and CD34 + cell counts for PB samples (r=0.669) and for CD34 + cell suspensions (r=0.859). Analysis of purified CD34 + cells using the SE-9500 HPC mode revealed that they appear both in the blast cell area and the immature granulocyte area of the analyser cell display. Quantitation of CD34 + cells and HPC during PBSC mobilisation showed good agreement between these parameters with regard to the optimal time for PBSC harvesting. These findings suggest that HPC counting with the Sysmex SE-9500 may be clinically useful for optimising the timing of PBSC collection.

Laboratory evaluation of the Sysmex SE-9500 automated haematology analyser

The Sysmex SE-9c500 is a new, fully automated haematology analyser, providing a complete blood count (CBC), including a five-part differential count (DC), with flagging of morphological abnormalities. The SE-9500 was evaluated according to guidelines published by the International Committee for Standardisation in Haematology (ICSH). The results demonstrated minimal carryover (< 0.01%) and excellent linearity for WBC, RBC, HGB and platelet (PLT) (r > 0.995). Samples were stable with regard to CBC parameters after storage for up to 48 h at room temperature (RT) and 4 degrees C. Imprecision was generally acceptable for all CBC parameters (CV < 5%). Correlation between the SE-9500 and reference methods was excellent (r > 0.97) for all the major CBC parameters (WBC, RBC, HGB, PLT). There was minimal interference for WBC, RBC, HGB and PLT at high concentrations of bilirubin (BIL=224 micromol/l) or triglyceride (TG=7.78 mmol/l). SE-9500 reference values for CBC parameters are presented. Our results indicate that the SE-9500 is an excellent tool for routine haematological examination.

The Aalpha6 locus: its relation to mating-type regulation of sexual development in Schizophyllum commune

We have isolated and examined the Aalpha6 mating-type locus of Schizophyllum commune as a first step toward resolving a functional difference between this locus and the Aalpha loci previously studied. Our analyses show Aalpha6 to be remarkably similar to the Aalpha loci of known structure. The locus is composed of two, divergently transcribed genes similar in size to known Z and Y genes of the Aalpha loci. We have termed the two genes, Z6 and Y6, on the basis of their demonstrated mating activities and encoded protein motifs. The Z6 gene encodes a homeodomain-related sequence, two acidic regions and a predicted coiled-coil motif. The Y6 gene encodes a homeodomain, predicted coiled-coil motif, two regions with homology to the Abeta locus gene V6, a basic region encoding a putative nuclear localization sequence and a serine-rich region. The Z6 and Y6 proteins share these features with the other known Z and Y proteins, respectively. One of the two amino acid sequences with homology to the AbetaV6 protein has not previously been reported.