Immunoglobulin M Enzyme-Linked Immunosorbent Assay Using Recombinant Polypeptides for Diagnosis of Dengue

We demonstrate that a mixture of four recombinant dengue virus E polypeptides corresponding to the N-terminal region of the envelope protein from all serotypes substitutes for standard antigens in two immunoglobulin M enzyme-linked immunosorbent assay formats with 100% concordance, making these polypeptides a useful and accessible reagent for serological diagnosis of dengue in endemic countries.     

Preemptive plasmapheresis and recurrence of focal segmental glomerulosclerosis in pediatric renal transplantation

Gonzalez E, Ettenger R, Rianthavorn P, Tsai E, Malekzadeh M. Preemptive plasmapheresis and recurrence of focal segmental glomerulosclerosis in pediatric renal transplantation.
Pediatr Transplantation 2011: 15: 495–501. © 2011 John Wiley & Sons A/S. Abstract: FSGS has a high recurrence rate after renal transplantation. To examine the effects of the use of preemptive and post‐transplant PP on recurrence and graft outcome, we conducted a retrospective study on 34 pediatric patients (mean age 13 ± 5 yr) with biopsy‐proven pretransplant FSGS and who underwent a renal transplantation between 1996 and 2007. Recurrence was defined as a serum albumin level of <3.0 g/L in the presence of nephrotic‐range proteinuria (>40 mg/m²/h). Total response to PP therapy was defined as the resolution of the nephrotic‐range proteinuria and partial response as persistent proteinuria despite PP but not in the nephrotic range. Fifteen patients received a LD renal transplantation and 19 patients received a DD renal transplantation. Nineteen patients received CsA and 14 patients received tacrolimus. Nineteen patients (56%) had FSGS recurrence. There was no difference in the recurrence rate between patients receiving CsA vs. tacrolimus. Among the 15 LD patients, 13 received preemptive PP (1–10 sessions) and seven patients (47%) had subsequent FSGS recurrence. Among the 19 DD patients, four received preemptive PP and 12 (63%) had FSGS recurrence. The number of preemptive PP did not affect the recurrence rate. In a group of patients with a previous graft loss secondary to recurrence, the rate of recurrence was lower than expected (40%) and two of the three patients who did not recur had three or more sessions of preemptive PP. Of the 19 patients with recurrence, 17 were treated with PP therapy and 88% of the patients fully or partially responded. Only five patients had graft loss at three yr post‐transplant: two from FSGS recurrence and three from non‐compliance. These results suggest that preemptive PP does not decrease the rate of recurrence after transplantation but might be beneficial in treating high‐risk patients with documented recurrence. Patients with FSGS recurrence post‐transplant can achieve good graft survival with both LD and DD transplantation.     

Angiotensin II regulates vascular endothelial growth factor via hypoxia-inducible factor-1alpha induction and redox mechanisms in the kidney

Angiotensin II (AngII) is a cytokine that participates in renal damage. Vascular endothelial growth factor (VEGF) is constitutively expressed in the kidney and is involved in the progression of renal disease. The aim of this work was to investigate the relation between AngII and VEGF and the mechanisms involved in its regulation in the kidney. We have observed that in cultured tubuloepithelial cells (NRK52E cell line) AngII increased VEGF gene expression and promoter activation. Hypoxia-inducible factor-1 (HIF-1) is one of the main VEGF gene activators. AngII induces HIF-1alpha protein production and increases HIF-1 DNA-binding activity. An antisense HIF-1alpha oligodeoxynucleotide inhibited AngII-induced VEGF overexpression. The reactive oxygen species act as second messengers in kidney damage caused by AngII and mediate the induction of HIF-1 by cytokines. In tubuloepithelial cells, VEGF up-regulation and HIF-1alpha induction due to AngII were significantly diminished by antioxidants, suggesting a redox-mediated mechanism. Infusion of AngII into mice caused renal VEGF overexpression, HIF-1 activation, and oxidative stress. In summary, these data show that AngII in vivo and in vitro up-regulates renal VEGF expression by a mechanism that involves HIF-1 activation and oxidative stress.     

Molecular pathology of well-differentiated thyroid carcinomas

The newly discovered molecular features of well-differentiated thyroid carcinomas derived from follicular cells are reviewed, within the frame of the 2004 WHO classification of thyroid tumours, under the following headings: “Follicular carcinoma”, “Papillary carcinoma”, “Follicular variant of papillary carcinoma” and “Hürthle cell tumours”. A particular emphasis is put on the meaning of PAX8–PPARγ rearrangements, RAS and BRAF mutations, and deletions and mutations of mitochondrial genes and of nuclear genes encoding for mitochondrial enzymes, for thyroid tumorigenesis.     

Premenstrual dysphoric disorder and changes in frontal alpha asymmetry.

OBJECTIVE: Since the clinical picture of premenstrual dysphoric disorder (PMDD) in the Luteal phase of the menstrual cycle is characterized by extreme negative affect, we predicted and obtained a change in frontal cortical EEG alpha asymmetry, which has been shown to be an index of affect. METHOD: We observed two monthly cycles for five women diagnosed as having PMDD and one monthly cycle for five non-PMDD control subjects. RESULTS: Asymmetry percent scores for the five PMDD women, and for the five control subjects before and after the Luteal phase were typically within the normal non-depressed range, however the asymmetry scores for the PMDD group fell into the negative range during the Luteal period while the control subjects remained stable. DISCUSSION: We predicted alpha asymmetry scores would be affected by the luteal phase in PMDD cases. This hypothesis was clearly confirmed.     

Expression of Simple Mucin Type Antigens and Lewis Type 1 and Type 2 Chain Antigens in the Thyroid Gland: An Immunohistochemical Study of Normal Thyroid Tissues,Benign Lesions,and Malignant Tumors

In order to characterize the pattern of expression of carbohydrate structures in several types of thyroid tissues and to evaluate the putative usefulness of the detection of such antigens in diagnostic surgical pathology, we undertook the immunohistochemical study of simple mucin type antigens (T, Tn, and sialyl Tn), Lewis type I antigens (Lewis a, sialyl Lewis a, and Lewis b), and Lewis type 2 related antigens (precursor type 2, H type 2, Lewis x, sialyl Lewis x, and Lewis y) in thyroid samples obtained from 65 patients. The material consisted on paraffin sections of normal thyroid (n = 43), benign lesions (13 goiters/ hyperplastic lesions and 15 adenomas), and malignant tumors (12 follicular carcinomas and 27 papillary carcinomas, 5 of which had lymph node metastases) of the thyroid follicular epithelium. Tn, T, and precursor type 2 antigens were the only antigens that were detected—and very rarely—in normal thyroid. Benign lesions were similar to normal thyroid despite displaying a higher prevalence of immunoreactivity for severa antigens of the three groups. Thyroid carcinomas presented a significantly higher level of expression of all types of simple mucin, Lewis type 1, and Lewis type 2 antigens than the normal thyroid and benign lesions. The expression of sialyl Tn was restricted to malignant tumors, and the expression of sialyl Lewis x was closely associated, though not exclusively, to papillary carcinomas. The immunoreactivity was stronger and the number of positive cases was higher in papillary than in follicular carcinomas. No differences were found between primary tumors and the respective metastases. The existence of distinct patterns of expression of carbohydrate antigens in different types of thyroid lesions points to the usefulness of the detection of some of these antigens in thyroid surgical pathology. The putative role of such antigens in the peculiar metastatic properties of thyroid carcinomas remains unsettled.     

Evaluation of the Reactivity of Sera from Patients with Systemic Lupus Erythematosus Against the Human MCP1

This study evaluates metaphase chromosome protein 1 (MCP1), a nuclear antigen, as a diagnostic marker for systemic lupus erythematosus (SLE). Reactivity of sera from 114 Portuguese patients with autoimmune rheumatic disease or from healthy blood donors (HBD), against MCP1, produced in bacteria (bact-MCP1) or in its native form (native-MCP1), was determined by immunoblotting. Predictive and discriminative power of MCP1 reactivity for SLE diagnosis in disease-control groups was evaluated by logistic regression, its diagnostic value determined by receiver-operating characteristic analysis and compared with similar analysis of antinuclear antibody and double-stranded DNA (dsDNA). We demonstrated that native-MCP1, in contrast to bact-MCP1, reacts with SLE sera with significant predictive and discriminative power versus other autoimmune diseases (odds ratio [OR] ≤3.537 and ≥3.265; area under the receiver-operating characteristic curve [AUC] ≤0.643 and ≥0.636) or versus HBD (OR?=?5.006; AUC?=?0.671), showing a good diagnostic power with high specificity (82.1% versus HBD) and low sensitivity for SLE, similar to those of dsDNA. The reactivity of SLE sera with native-MCP1 was shown to be dependent on the presence of phosphorylated residues. Native-MCP1 was shown to have diagnostic value as a specific marker for SLE diagnosis and, therefore, is a suitable substrate for a new antibody test. The widely reported importance of phosphorylated epitopes as targets for autoantibodies in SLE could also be confirmed for native-MCP1.     

Upregulation of HTLV-1 and HTLV-2 expression by HIV-1 in vitro

Co-infections with HIV-1 and the human T leukemia virus types 1 and 2 (HTLV-1, HTLV-2) occur frequently, particularly in large metropolitan areas where injection drug use is a shared mode of transmission. Recent evidence suggests that HIV-HTLV co-infections are associated with upregulated HTLV-1/2 virus expression and disease. An in vitro model of HIV-1 and HTLV-1/2 co-infection was utilized to determine if cell free HIV-1 virions or recombinant HIV-1 Tat protein (200-1,000 ng/ml) upregulated HTLV-1/2 expression and infectivity. Exposure to HIV-1 increased the number of HTLV-1 antigen expressing cells, from 6% at baseline to 12% at 24 hr, and 20% at 120 hr (P < 0.05) post-exposure. A similar, although less robust response was observed in HTLV-2 infected cells. HIV-1 co-localized almost exclusively with HTLV-1/2 positive cells. Exposure to HIV-1 Tat protein (1,000 ng/ml) increased HTLV-1 p19 expression almost twofold by 48 hr, and cells co-stimulated with 10 nM phorbol myristate acetate (PMA) showed almost a fourfold increase over baseline. It is concluded that HIV-1 augments HTLV-1/2 infectivity in vitro. The findings also suggest a role for the HIV-1 Tat protein and PMA-inducible cellular factors, in HIV-1 induced HTLV-1/2 antigen expression.