Clonorchis sinensis enolase: identification and biochemical characterization of a glycolytic enzyme from excretory/secretory products

Enolase plays a key role in energy metabolism and development of most organisms. We isolated a gene encoding enolase from Clonorchis sinensis (C. sinensis) adult cDNA library and expressed the recombinant protein in Escherichia coli. C. sinensis enolase (Csenolase) was identified as both an excretory/secretory product and a tegumental component of C. sinensis by western blot analysis. The transcriptional level of Csenolase was examined at adult worm, metacercaria, cercaria and egg of C. sinensis, and results showed that Csenolase is transcribed at the four life stages of C. sinensis while showing a significant higher expression level at the stage of adult worm. Immunohistochemical localization indicated that Csenolase was specifically deposited on the tegument of adult worm and cyst wall of metacercaria. Ligand blot assay revealed a specific characteristic of dose-dependent plasminogen-binding activity of Csenolase and kinetic parameters were explored using 2-phospho-D-glycerate (2-PGA) as the primary substrate by monitoring the conversion of nicotinamide-adenine dinucleotide (NADH) into nicotinamide adenine dinucleotide (NAD). In addition, Csenolase exhibited active enzyme activity in catalytic reactions while the anti-Csenolase serum inhibited the enzyme activity. In vitro incubation experiments revealed that Csenolase might play key roles in the growth of the parasites. In conclusion, Csenolase is an important glycolytic enzyme required for the development of C. sinensis, and may be a potential vaccine candidate and drug target against C. sinensis infection.

Microsatellite analysis of clinical isolates of the opportunistic fungal pathogen Penicillium marneffei from AIDS patients in China

BACKGROUND

Penicillium marneffei is an opportunistic fungus that may cause fatal disease, and usually infects acquired immune deficiency syndrome (AIDS) patients. The molecular epidemiology of this fungus remains enigmatic.

METHODS

A multilocus microsatellite typing (MLMT) system based on 11 microsatellite loci was applied to 169 unrelated isolates of P. marneffei obtained from AIDS patients, in order to identify their genetic diversity. These patients came from the provinces of Guangdong and Guangxi, areas endemic for P. marneffei in China.

RESULTS

For the overall population, the average number of alleles per locus ranged from 3 to 8 (mean 5.5), while the discriminatory power (DP) of each locus ranged from 0.235 to 0.651 (mean 0.512). By combining the information generated for 11 loci, MLMT detected 159 different multilocus genotypes (MTs), resulting in a high degree of discrimination (DP = 0.999). One hundred and sixty-nine isolates were further clustered into 9 types (from A to I) at the similarity coefficient of 0.80, with type A (80 isolates) and type B (60 isolates) being the most common types. Within 5 subpopulations from different regions of China, the distribution of MTs of P. marneffei isolates was diverse. Although 169 isolates shared a high genetic similarity (range 0.71-0.933), isolates from Guangxi and Guangdong provinces could be differentiated from each other and clustered into 2 categories by unweighted pair-group method with arithmetic mean (UPGMA) cluster analysis.

CONCLUSIONS

By MLMT, the genetic diversity of clinical P. marneffei isolates could be discriminated, the dominant strain of P. marneffei cultured from AIDS patients in China could be identified, and clinical isolates of P. marneffei from Guangxi Province could be differentiated from those from Guangdong Province.

Geographic difference in safety and efficacy of systemic chemotherapy for advanced gastric or gastroesophageal carcinoma: A meta-regression approach

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Background: The standard of chemotherapy regimens for patients with advanced or metastatic gastric cancer vary and the clinical outcome were heterogeneous in Asian vs. non-Asian countries.

Methods: Treatment group-based meta-analysis and meta-regression were performed to analyze results of randomized trials published since 2005 for advanced or metastatic gastric cancer patients who received systemic chemotherapy as first-line treatment. Data were extracted and synthesized according to the Cochrane guidelines.

Results: Among the 24 trials (totally 6,502 patients) eligible for meta-analysis, Asian trials reported lower percentage of gastroesophageal junctional carcinoma, higher percentage of diffuse-type histology, and more frequent use of second-line chemotherapy. Meta- regression analyses indicate that, after controlling other patient or treatment factors, Asian trials are associated with 22.7% (95% CI: 19.5-26.0%, p<0.0001) lower incidence of grade 3-4 neutropenia and 3.5% (95% CI: 2.1-4.9%, p<0.0001) lower incidence of grade 3-4 diarrhea, which were the most commonly reported toxicity. The use of high-dose infusional 5-fluorouracil, compared with other fuoropyrimidine regimens, reported 16.6% lower incidence of neutropenia (95% CI: 13.3-19.9%, p<0.0001). Higher percentage of patients with gastroesophageal junction carcinoma and patients with 2 or more organs involved predicted poor progression-free survival. The use of second-line chemotherapy predicts better 1-year overall survival, which will increase by 9% (95% CI: 8-10%) for every 10 percent increase in patients who received second-line chemotherapy.

Conclusions: Geographic region (Asian vs. non-Asian) plays an important role in the heterogeneity of gastric cancer clinical trials and is an independent predictor of safety in systemic therapy for gastric cancer.

No significant financial relationships to disclose.

Next-generation small RNA sequencing for microRNAs profiling in the honey bee Apis mellifera

MicroRNAs (miRNAs) are key regulators in various physiological and pathological processes via post-transcriptional regulation of gene expression. The honey bee (Apis mellifera) is a key model for highly social species, and its complex social behaviour can be interpreted theoretically as changes in gene regulation, in which miRNAs are thought to be involved. We used the SOLiD sequencing system to identify the repertoire of miRNAs in the honey bee by sequencing a mixed small RNA library from different developmental stages. We obtained a total of 36,796,459 raw sequences; of which 5,491,100 short sequences were fragments of mRNA and other noncoding RNAs (ncRNA), and 1,759,346 reads mapped to the known miRNAs. We predicted 267 novel honey bee miRNAs representing 380,182 short reads, including eight miRNAs of other insects in 14,107,583 genome-mapped sequences. We verified 50 of them using stem-loop reverse-transcription PCR (RT-PCR), in which 35 yielded PCR products. Cross-species analyses showed 81 novel miRNAs with homologues in other insects, suggesting that they were authentic miRNAs and have similar functions. The results of this study provide a basis for studies of the miRNA-modulating networks in development and some intriguing phenomena such as caste differentiation in A. mellifera.

The molecular characteristics of cefepime-susceptible Escherichia coli and Klebsiella spp. isolates with a positive β-lactamase screening test result but negative confirmation

A negative extended-spectrum β-lactamase (ESBL) phenotypic confirmation test result obtained after a positive ESBL screening test result but which was cefepime-susceptible (NCPSCS) using the Clinical and Laboratory Standards Institute (CLSI) methods has been observed among isolates of Escherichia coli and Klebsiella spp. in the antimicrobial surveillance program in Shanghai, China. Among isolates collected from Huashan Hospital in 2005, NCPSCS strains were observed in 2.5% of 433 E. coli isolates and in 1.2% of 562 Klebsiella spp. isolates. We then selected 11 E. coli isolates and seven Klebsiella spp. NCPSCS isolates. Transmission electron microscopy (TEM), SHV, plasmid-borne AmpC, and CTX-M type ESBL genes were detected by the polymerase chain reaction (PCR) method. We found that all except two K. pneumoniae strains of NCPSCS isolates producing ESBL and AmpC harbored a plasmid-borne CMY-2 or DHA-1 type AmpC enzyme. The majority of NCPSCS E. coli and K. pneumoniae strains from Shanghai harbor plasmid-borne AmpC enzyme, and we recommend that, when NCPSCS strains are identified, further work such as the PCR detection of ESBL genes is necessary to determine whether they will produce ESBLs. The ESBL-positive strains should be reported as resistant to cefepime according to the CLSI guidelines.

Effect of hyperoxic resuscitation on propensity of germinal matrix haemorrhage and cerebral injury

AIMS

Intraventricular haemorrhage (IVH) and cerebral injury are major neurological disorders of premature infants. The effect of hyperoxic resuscitation on the occurrence of IVH and cerebral injury is elusive. Therefore, we asked whether hyperoxia during neonatal resuscitation increased the incidence and severity of IVH and cerebral injury in premature newborns.

METHODS

Premature rabbit pups, delivered by C-section, were sequentially assigned to receive 100%, 40% or 21% oxygen for 15 or 60 min at birth. The pups were treated with intraperitoneal glycerol at 24-h postnatal age to determine the incidence and severity of glycerol-induced IVH. Vascular endothelial growth factor and angiopoietin-2 genes and protein expression, endothelial proliferation as well as free radical levels and antioxidants were assessed in the germinal matrix, white matter and cortex of pups exposed to 100% oxygen and to 21% oxygen.

RESULTS

Exposure with 100% oxygen for 1 h did not adversely exacerbate the incidence of glycerol-induced IVH in premature rabbit pups. Compared with room air, 100% oxygen enhanced mRNA expression of both vascular endothelial growth factor and angiopoietin-2 as well as reactive oxygen species levels in the germinal matrix. Hyperoxia did not affect endothelial proliferation, apoptosis or neuronal degeneration in the forebrain.

CONCLUSION

Our data suggest that 100% oxygen exposure for 1 h does not increase the risk of IVH or cerebral injury in premature rabbit pups. Although extrapolating rabbit neural developmental data into humans has obvious limitations, we speculate that hyperoxia of short duration at birth in premature infants may not result in major neurological adverse effects.

Stage and tissue specific differences in SjBMI1, a Polycomb protein in Schistosoma japonicum

Polycomb group protein BMI1, plays a central role in the stem cell pluripotency and development in metazoans. A gene encoding BMI1 homologue in the Schistosoma japonicum (SjBMI1) was cloned and identified. The deduced amino acid sequence shows high identity to the homologues from Schistosoma mansoni and Homo sapiens. Quantitative real time polymerase chain reaction (RT-PCR) and Western blot analysis revealed that the SjBMI1 is highly expressed in adult worms and eggs, not in cercariae. By immunofluorescent studies, SjBMI1 was localized to testes, ovaries of mixed sex infected adult worms, but not of single sex infected adult worms. The study reveals the SjBMI1 expression profile in developmental stages and localization characteristic and provides a clue that it may be associated with reproductive development of S. japonicum.

Molecular characterization of a novel Clonorchis sinensis secretory phospholipase A(2) and investigation of its potential contribution to hepatic fibrosis

A gene encoding a homologue of phospholipase A(2) was identified from the Clonorchis sinensis adult cDNA plasmid library. The deduced amino acid sequence including a signal peptide that has 28-46% identity with secretory phospholipase A(2), group III (group III sPLA(2)) of other species. It also has typical features of group III sPLA(2)s including 10 cysteines, the key residues of the Ca(2+) loop and catalytic site. The recombinant protein encoded by this gene expressed in Escherichia coli showed a product of about 34kDa in SDS-PAGE. Prediction of signal peptide and Western blot analysis indicated the group III secretory phospholipase A(2) of C. sinensis (CsGIIIsPLA(2)) was an excretory-secretory product (ES product). The enzyme activity of the recombinant protein was determined using phosphatidylcholine as substrates. The result revealed that the protein was a Ca(2+)-dependent PLA(2). Both MTT test and cell cycle analysis of LX-2 showed a higher percentage of cells are in proliferation phase. Semi-quantitative RT-PCR experiments demonstrated an up-regulated expression of collagen III in these cells after incubation with the recombinant protein. We also identified that the recombinant CsGIIIsPLA(2) could bind to some membrane proteins on LX-2 cells specifically by immunofluorescence, thus there might be receptors of CsGIIIsPLA(2) on the LX-2 cell membrane. Our results suggest that CsGIIIsPLA(2) might play an important role in the initiation and development of hepatic fibrosis caused by C. sinensis.

Quality of life in advanced non-small cell lung cancer patients receiving first-line gefitinib monotherapy

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Background: Gefitinib is a potential first-line treatment option for patients with advanced non-small cell lung cancer (NSCLC), especially for patients with activating mutations in the EGFR gene. However, little is known about patient-reported health-related quality of life (HRQOL) in this patient population. The aims of this study were to explore the prognostic values of baseline HRQOL for time-to-treatment failure (TTF), as well as the predictors of repeatedly measured posttreatment HRQOL, in advanced NSCLC patients receiving first-line gefitinib. Methods: A total of 106 chemonaive patients with advanced NSCLC were enrolled in a phase II trial. Gefitinib was given at a dose of 250 mg/d. HRQOL was assessed monthly with the EuroQoL instrument (EQ-5D) and the Lung Cancer Symptom Scale (LCSS) questionnaire. Baseline HRQOL and clinical/molecular predictors of TTF were jointly examined by multiple Cox's proportional hazards model. The associations between the clinical/molecular factors and repeatedly measured posttreatment HRQOL were analyzed by fitting marginal linear regression model using the generalized estimating equations (GEE) method. Results: In this prospective study, HRQOL data were obtained from 94 patients. Baseline EQ-5D index (estimated hazard ratio = 0.286, 95% C.I.: 0.135–0.603, p = 0.001) and the presence of L858R EGFR mutation in adenocarcinoma (estimated hazard ratio = 0.520, 95% C.I.: 0.307–0.880, p = 0.015) were retained as independent prognostic factors in the final multiple Cox's proportional hazards model for TTF. According to preliminary GEE analysis of repeatedly measured posttreatment HRQOL, the patients with wild-type EGFR consistently had worse HRQOL in EQ-5D index (p < 0.0001), EQ-5D VAS score (p = 0.0002), and LCSS global score (p < 0.0001), respectively. Conclusions: In advanced NSCLC patients receiving first-line gefitinib, better baseline EQ-5D index and L858R EGFR mutation in adenocarcinoma predict longer TTF. In addition, patients with wild-type EGFR had worse posttreatment HRQOL.

No significant financial relationships to disclose.

A phase I trial of intratumoral administration of recombinant oncolytic adenovirus overexpressing HSP70 in advanced solid tumor patients

Our pre-clinical studies demonstrated that intratumoral vaccination with a recombinant oncolytic type 2 adenovirus overexpressing the heat shock protein (HSP)70 protein, designated as H103, can inhibit primary and metastatic tumors through enhanced oncolytic activity and HSP-mediated immune responses against shared and mutated tumor antigens. In the pre-clinical studies of local H103 administration, no significant toxicity was observed in the animal trials with mice, cavy or rhesus monkeys. A phase I clinical trial of intratumoral injection of H103 was conducted in the patients with advanced solid tumors. A total of 27 patients were injected intratumorally with H103 in a dose-escalation study from a dose of 2.5 x 10(7) to 3.0 x 10(12) viral particles (VPs). The maximum tolerated dose of H103 was not defined. Two patients developed dose-limiting toxicities of grade III fever at the dose of 1.5 x 10(12) VP and transient grade IV thrombocytopenia at the dose of 3.0 x 10(12) VP. The common adverse events were mainly mild to moderate (grade I/II) in nature, including fever, mild injection-site reaction, leucopenia, lymphopenia, thrombocytopenia and hypochromia. The objective response (complete response+partial response) to H103-injected tumors was 11.1% (3/27), and the clinical benefit rate (complete response+partial response+minor response+stable disease) was 48.1%. Interestingly, transient and partial regression of distant, uninjected tumors was observed in three patients. The numbers of immune cells (CD4(+) and CD8(+) T cells, and natural killer cells) were elevated after H103 administration, but without statistical significance. This phase I trial demonstrates that intratumoral administration of H103 can be safely applied to cancer patients and shows promising clinical antitumor activity, warranting a further clinical investigation.

NOD2-expressing bone marrow-derived cells appear to regulate epithelial innate immunity of the transplanted human small intestine

BACKGROUND

Intestinal allograft rejection resembles Crohn's disease clinically and pathologically. An understanding of its mechanism could impact this life-saving procedure, as well as provide insight into the pathophysiology of inflammatory bowel disease. The NOD2 protein has been implicated as a key player in intestinal immune health, as a consequence of the discovery of three polymorphisms linked with Crohn's disease. An investigation was carried out to determine whether epithelial immune function and graft survival were influenced by NOD2 mutations in an intestinal transplant population.

METHODS

The NOD2 genotypes of 34 transplants performed consecutively over the past 3 years were determined. The NOD2 genotypes were related to clinical outcomes and the expression of certain intestinal antimicrobial peptides (AMPs) believed to protect the epithelium.

RESULTS

An unexpectedly high percentage of recipients, 35%, possessed NOD2 polymorphisms, while 8.6% of donors had comparable mutations. The likelihood of allograft failure was about 100-fold higher in recipients with mutant NOD2 alleles compared with recipients with wild-type NOD2 loci. Rejection in NOD2 mutant recipients was characterised by decreased expression of certain Paneth cell and enterocyte AMPs, prior to the onset of epithelial injury and inflammation.

CONCLUSIONS

Crohn's disease-associated polymorphisms in the NOD2 gene in the recipient represent a critical immunological risk factor for intestinal allograft rejection. Compromised epithelial defences precede visible epithelial injury and inflammatory infiltration. The association of impaired epithelial immunity with the recipient's genotype suggests that certain NOD2-expressing cells of haematopoietic origin play a role in the process, perhaps by regulating expression of certain epithelial AMPs within the allograft.

A five-year follow-up study of goiter and thyroid nodules in three regions with different iodine intakes in China

OBJECTIVE

The association between iodine status and the prevalence of goiter and thyroid nodules has been well established but the extent to which different iodine intake levels influence the incidence of goiter and thyroid nodules is unclear. The aim of the study was to determine the incidence of goiter and thyroid nodules in 3 regions with different iodine intake levels: mildly deficient, more than adequate, and excessive.

DESIGN, PATIENTS AND MEASUREMENTS

Of the 3385 unselected subjects enrolled in 1999 in Panshan, Zhangwu, and Huanghua where median urinary iodine excretion (UIE) was 83.5 microg/l, 242.9 microg/l, and 650.9 microg/l, respectively, 2708 (80.0%) participated in the follow-up study in 2004. The examinations of thyroid ultrasonography, thyroid function, thyroid autoantibodies and UIE were performed at baseline and follow-up.

RESULTS

The cumulative incidence of diffuse goiter was 7.1%, 4.4%, and 6.9%, respectively, higher in Panshan and Huanghua than in Zhangwu (p=0.013 and p=0.015) and that of nodular goiter was 5.0%, 2.4%, and 0.8%, respectively, declining with increasing iodine intake levels (p<0.001). Mild iodine deficiency, chronic iodine excess as well as positive thyroid autoantibodies were associated with the occurrence of goiter [Logistic regression: odds ratio (OR)=1.83 (95% confidence interval (CI) 1.26-2.65), OR=1.46 (95% CI 1.01-2.11) and OR=1.68 (95% CI 1.14-2.48), respectively]. The cumulative incidence of single nodule was 4.0%, 5.7%, and 5.6%, respectively and that of multiple nodules was 0.4%, 1.2%, and 1.0%, respectively.

CONCLUSIONS

The relationship between iodine and the risk for the occurrence of diffuse goiter shows a U-shaped curve. Nodular goiters are more prevalent in iodine-deficient areas.

Survival outcome and cost-effectiveness with docetaxel and paclitaxel in patients with metastatic breast cancer: a population-based evaluation

BACKGROUND

A randomized controlled trial showed longer overall survival (OS) with docetaxel compared with paclitaxel in metastatic breast cancer patients with prior exposure to anthracycline. We report a similar comparison using population-based data.

METHODS

Data on patients treated with single-agent paclitaxel or docetaxel were retrospectively reviewed. OS was compared using a two-tailed log-rank test and expressed as Kaplan-Meier plots. A cost-effectiveness analysis was carried out using cost/patient and OS.

RESULTS

Four hundred and thirty-five patients met eligibility criteria. Prognostic factors were balanced between docetaxel and paclitaxel groups. Median OS was significantly longer for docetaxel versus paclitaxel [10.9 versus 8.3 months; hazard ratio 0.76; 95% confidence interval (CI), 0.62-0.92; P = 0.006]. The median number of cycles administered were four (docetaxel) and three (paclitaxel). The incremental cost-effectiveness ratio was $2434/per month of median survival gained. In the sensitivity analysis, the results were robust except that paclitaxel dominated when the low end of the 95% CI of survival for docetaxel was compared with the high end for paclitaxel.

CONCLUSION

This population-based study corroborated the randomized trial's conclusion that for patients with metastatic breast cancer, docetaxel provided superior survival compared with paclitaxel. Each additional month of survival had an incremental cost of $2434.

Immunogenicity of recombinant Bacillus subtilis spores expressing Clonorchis sinensis tegumental protein

Clonorchis sinensis, which causes clonorchiasis, is of major socioeconomic importance in China. In this study, we report the use of CotC, a major component of the Bacillus subtilis spore coat, as a fusion partner for the expression of C. sinensis TP20.8 (Tegumental Protein 20.8 kDa) on the spore coat. Western blotting was used to identify TP20.8 surface expression on spores. Recombinant spores displaying the TP20.8 antigen were used for oral immunization and were shown to generate mucosal response in rats. TP20.8-specific secretory IgA in feces reached significant levels 2 weeks after oral dosing. This report shows that surface display of recombinant C. sinensis TP20.8 on B. subtilis spores was immunogenic and B. subtilis spores can be used as a mucosal immunization vehicle for parasite prevention and control.

The association of epidermal growth factor receptor (EGFR) polymorphisms and clinicopathological factors with skin rash on gefitinib use

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Background: Skin rash is the most common toxicity of EGFR-targeted therapy. Skin rash of EGFR inhibitor is associated with longer survival or tumor response. However, the clinical and genetic factors associated with this skin rash are not well understood. Methods: Fifty-two non-small-cell lung cancer patients enrolled in a prospective clinical trial of first-line gefitinib treatment were genotyped for EGFR intron 1 CA repeat polymorphism (CAn) and single nucleotide polymorphisms at promoters G-216T, C-191A, and R521K. Grade 2 to 3 skin rash within 4 weeks of treatment (early G2/3 rash) was correlated with the genotype and clinicopathological features of the patients by multivariate logistic regression. Results: Seventeen patients (32.7%) developed early G2/3 rash. In multivariate logistic regression analysis, only the CAn genotype was associated with early G2/3 rash and the effect was modified by patient age. Early G2/3 rash developed in 21% of patients with homozygous long allele (19 to 22 repeats, L) genotype (4/19), 31% of heterozygous short allele (15 to 18 repeats, S) / L genotype (8/26), and 71% of S/S genotype (5/7), respectively. The median ages of patients with early G2/3 rash and patients without early G2/3 rash were 57 years (range: 39–77) and 69 years (range: 43–86), respectively. The estimated logarithm of odds ratio (ln OR) for early G2/3 rash, as compared to S/S genotype, for S/L genotype was -0.038 multiplied by patient age (P = 0.011); and the ln OR for L/L genotype was -0.050 multiplied by patient age (P = 0.004). Fifty patients were evaluable for response. In logistic regression analysis, early G2/3 rash correlated with tumor response (P = 0.027). However, the CAn genotype was not significantly correlated with tumor response (P = 0.43). Conclusions: Homozygous short allele of EGFR CAn is more likely to develop skin rashes on gefitinib treatment. Genotyping of EGFR CAn appears to be a useful predictive marker for development of skin rashes on gefitinib use.

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Molecular cloning and identification of a novel Clonorchis sinensis gene encoding a tegumental protein

The tegumental membrane of platyhelminth parasites is of crucial importance for modulation of the host response and parasite survival. A cDNA encoding a novel tegumental protein 20.8 kDa (TP20.8) was found by large-scale sequencing of a Clonorchis sinensis cDNA library. This new cDNA was 755 bp long containing an open reading frame of 555 bp, which encoded a 20.8-kDa protein with an isoelectric point of 4.33. The deduced amino acid sequence exhibits 40 and 37% identity to Schistosoma japonicum sj20.8 and Schistosoma mansoni Sm 20.8, respectively. TP20.8 transcripts were detected in the adult worm and metacercariae cDNA libraries of C. sinensis but not in the egg. Recombinant C. sinensis TP20.8 protein was produced and purified from Escherichia coli BL21. Using specific anti-recombinant TP20.8 protein sera, the TP20.8 protein was immunohistochemically localized to the outer-surface membrane of C. sinensis. The specificity and sensitivity of the recombinant antigen for serologic diagnosis was assessed by enzyme-linked immunosorbent assay using serum from 100 patients with clonorchiasis, 20 patients with schistosomiasis, and 30 negative controls. The sensitivity was 68%, and the specificity was 84%. The antigen was less useful for the serodiagnosis of clonorchiasis with IgG.