Immunological markers in patients with different forms of viral hepatitis B treated by "conventional" therapy or with HuIFN alpha

Selected immunological, biochemical, and other viral hepatitis B (VH-B) markers were followed and analysed during "conventional" or human interferon alpha (HuIFN alpha) therapy of patients with different forms of VH-B. The immunological data obtained from "conventionally"-treated acute hepatitis B (AH-B), prolonged acute hepatitis B (AH-BP) or chronic active hepatitis B (CAH-B) patients disclosed differences unsatisfactory for comparison of the influence of HuIFN alpha therapy on changes of the immunological markers. More valuable data were obtained through continuous registration of the dynamics of selected blood markers. Partial effects on immunological parameters were seen after HuIFN alpha administration to 2 patients with developing CAH-B infection. Progression of the disease was markedly halted in these both patients after IFN treatment.     

Heat-shock protein (HSP70-2) allelic frequencies in three distinct Mexican populations

The major histocompatibility complex (MHC) genes are highly polymorphic and therefore have been useful in population genetics and disease association studies. We analyzed restriction fragment length polymorphism of HSP70-2 alleles in healthy unrelated Mestizo, Mazatecan and Nahua populations. Both Indian groups, Mazatecans and Nahuas, were in Hardy-Weinberg equilibrium, while Mestizos were in disequilibrium (chi 2 = 0.399; P < 0.05). The Mazatecan Indians presented a high frequency of BB homozygosity (17.35%) compared to Mestizos (5%) (P = 0.01). Mexican ethnic groups present differences in distribution of BB genotype. The low frequency of BB genotype in Mestizos may be the result of a negative selection process.     

Volatile substances from larval habitats mediate species-specific oviposition in Anopheles mosquitoes

Oviposition site selection has been recognized as critical both for the survival and population dynamics of mosquitoes. Volatile substances released from larval habitats have been implicated as potential olfactory cues mediating oviposition. In our continuing studies of cues involved in oviposition site selection, we collected material from the larval habitats of Anopheles albimanus Wiedemann and Anopheles vestitipennis Dyar & Knab, i.e., cyanobacterial mats and Typha domingensis Pers. litter, respectively. The volatile compounds were extracted by freeze-drying the material and trapping the volatilized material on a -55 degrees C titanium condenser. For oviposition trials conducted with wild-caught females, the tested volatile materials were pipetted onto filters floating on the surface of distilled water in Teflon beakers that were placed within oviposition cages. For both species, volatile materials in low concentrations increased oviposition, assessed as egg density, whereas there was a shift to reduced oviposition at higher concentrations. Volatile effect was strongly habitat/species-specific as shown by reciprocal treatment tests.     

Herpes Simplex Virus Type 1 (HSV-1) Strain HSZP Host Shutoff Gene: Nucleotide Sequence and Comparison with HSV-1 Strains Differing in Early Shutoff of Host Protein Synthesis

The UL41 gene of the HSZP strain of herpes simplex virus type 1 (HSV-1) defective with respect to the early shutoff of host protein synthesis was sequenced and compared with the corresponding HSV-1 strain KOS and 17 gene sequences. In comparison with strain 17, nine mutations (base changes) were HSZP specific, five KOS specific and four were common for both strains. Nine mutations caused codon changes. Three of these mapped to the nonconserved regions and the others to the conserved regions of the functional map of UL4l gene. One KOS specific mutation mapped to the region responsible for the binding of the virion host shutoff (vhs) protein to the alpha-transinducing factor (VP16). The possible relationship between mutations and host shutoff function is discussed. The nucleotide sequence data of the UL41 gene of HSZP and KOS have been submitted to the Genbank nucleotide database and have been assigned the accesion numbers Z72337 and Z72338. This revised version was published online in July 2006 with corrections to the Cover Date.     

Assessment of the interaction of human complement regulatory proteins with group A Streptococcus. Identification of a high-affinity group A Streptococcus binding site in FHL-1

Group A Streptococcus (GAS), the most frequent bacterial cause of suppurative infections in humans, expresses on the cell surface M proteins with capacity to bind factor H, FHL-1 and C4b binding protein (C4BP). This has been interpreted as a mechanism developed by this pathogen to decrease phagocytosis by macrophages and polymorphonuclear cells. We report the analysis of the capacity to bind factor H, FHL-1 and C4BP of 69 clinical isolates from 19 different serotypes. We show that strains binding complement regulators (30/69) belong to specific M serotypes. Of these, M18 strains are relatively frequent and interact with all three complement regulators simultaneously. However, the most virulent M1 and M3 strains did not bind complement regulators in our assays. The relevance of the interaction between complement regulators and S. pyogenes was analyzed using different approaches with the conclusion that under physiological conditions only FHL-1 and C4BP bind to streptococci. We show that FHL-1 presents a higher binding affinity for S. pyogenes than factor H because it carries a hydrophobic, high-affinity, GAS binding site in addition to the heparin binding site in SCR7. Using synthetic peptides we provide evidence that the high-affinity GAS binding site in FHL-1 involves the hydrophobic tail (Ser-Phe-Thr-Leu) that distinguishes FHL-1 from factor H.     

Phenotype-genotype characterization of 10 families with severe a subunit factor XIII deficiency

Factor XIII (FXIII) deficiency is a very rare severe autosomal bleeding disorder with a frequency of 1:2,000,000 in the general population and only a few patients have been genetically characterized so far. We report a phenotype-genotype characterization of 10 unrelated Iranian patients. Two FXIII (transglutaminase) activity assays showed no FXIII activity, except a conserved residual activity in patients receiving prophylactic substitution treatment. FXIII antigen concentrations measured by two immunoassays were comparable. Genotype characterization identified four novel mutations (2 missense and 2 small deletions) and two previously reported missense mutations in the FXIII A subunit gene (F13A). Molecular modeling was carried out to reveal the structural consequences of the missense mutations, that caused the replacement of an arginine residue involved in the formation of structurally important extensive hydrogen-bonded network. The replacements [c.320G>A (p.Arg77His) in the beta-sandwich, c.868C>T (p.Arg260Cys), c.869G>A (p.Arg260His) and c.1236G>T (p.Arg382Ser) in the core domain] resulted in the loss or impairment of such H-bonded network. Energy decomposition analysis demonstrated that this situation leads to the instability and perhaps to the incorrect folding of the A subunit, that would explain the development of severe FXIII deficiency.     

RNA interference screening in ticks for identification of protective antigens

Ticks are ectoparasites of wild and domestic animals and humans, and are considered to be the most important arthropod vector of pathogens in North America. Development of vaccines directed against tick proteins may effect reduction of tick infestations and transmission of tick-borne pathogens. The limiting step for the development of tick vaccines has been the identification of tick protective antigens. Reverse vaccinology approaches aimed at reducing animal experimentation while allowing for the rapid screening of pools of potential tick vaccine candidates would greatly facilitate progress towards the development of tick vaccines. Herein, we describe the screening of Ixodes scapularis cDNAs for identification of tick protective antigens using RNA interference (RNAi). The results of the RNAi screening were similar to those obtained previously using expression library immunization and demonstrated that RNAi could serve as a more rapid and cost-effective tool for vaccine antigen discovery in ticks and in other nonmodel organisms.     

Nonmyeloablative stem cell transplantation is an effective therapy for refractory or relapsed hodgkin lymphoma: results of a spanish prospective cooperative protocol.

We report the results of reduced-intensity conditioning allogeneic stem cell transplantation (allo-RIC) in patients with advanced Hodgkin lymphoma (HL). Forty patients with relapsed or refractory HL were homogeneously treated with an RIC protocol (fludarabine 150 mg/m(2) intravenously plus melphalan 140 mg/m(2) intravenously) and cyclosporin A and methotrexate as graft-versus-host disease (GVHD) prophylaxis. Twenty-one patients (53%) had received >2 lines of chemotherapy, 23 patients (58%) had received radiotherapy, and 29 patients (73%) had experienced treatment failure with a previous autologous stem cell transplantation. Twenty patients (50%) were allografted in resistant relapse, and 38 patients received hematopoietic cells from an HLA-identical sibling. Five patients (12%) died from early transplant-related mortality (before day +100 after allo-RIC). One-year transplant-related mortality was 25%. Acute GVHD developed in 18 patients (45%). Chronic GVHD developed in 17 (45%) of the 31 evaluable patients. The response rate 3 months after the allo-RIC was 67% (21 [52%] complete remissions and 6 [15%] partial remissions). Eleven patients received donor lymphocyte infusions (DLIs) for disease relapse. The response rate after DLI was 54% (3 complete remissions and 3 partial remissions). Overall survival (OS) and progression-free survival (PFS) were 48% +/- 10% and 32% +/- 10% at 2 years, respectively. Refractoriness to chemotherapy was the only adverse prognostic factor for both OS (63% +/- 12% versus 35% +/- 13%; P = .05) and PFS (55% +/- 16% versus 10% +/- 9%; P = .006). For patients with failure of a prior autologous hematopoietic stem cell transplantation, results were especially good for those who experienced late relapses (>/=12 months: 2-year OS and PFS were 75% +/- 16% and 70% +/- 18%, respectively). These data suggest that allo-RIC is feasible in heavily pretreated HL patients and has an acceptable early transplant-related mortality. Results are better in patients allografted in sensitive disease. Both responses observed after the development of GVHD and DLI may suggest a graft-versus-HL effect. Allo-RIC has to be considered an effective therapeutic approach for patients who have had treatment failure with a previous autologous hematopoietic stem cell transplantation.