C1q,autoimmunity and apoptosis

Deficiency of classical pathway complement components displays a hierarchical association with the development of systemic lupus erythematosus (SLE). Individuals with deficiency of C1q, the first component of the classical pathway of activation, have the highest prevalence of SLE and the most severe manifestations of the disease. However, complement is also implicated in the effector inflammatory phase of the autoimmune response that characterizes SLE. Complement proteins are deposited in inflamed tissues causing consumption of complement. In addition, autoantibodies to C1q develop as part of the autoantibody response. Understanding how C1q deficiency results in the autoimmune phenotype of SLE may provide valuable clues to the role of the complement system in the maintenance of immune tolerance. In this review firstly we discuss the relationship between C1q deficiency and/or consumption and lupus. Secondly, we consider the links between apoptosis and complement. Finally we review the lessons we have learned from a murine model of C1q deficiency discussing the experimental evidence in support of the hypothesis that C1q may critically influence the immune response to self-antigens contained within the surface blebs generated by apoptotic cells.     

Serum procalcitonin levels in chronic hepatitis C patients under pegylated interferon-alpha plus ribavirin treatment.

OBJECTIVES: To evaluate the alterations of serum procalcitonin (PCT) levels in patients with chronic hepatitis C during pegylated interferon-alpha (PEG-IFNa) plus ribavirin (RIB) treatment and to correlate them with clinical and virological outcomes. STUDY DESIGN: Fifty-two consecutive patients (29 males, age=41.2+/-14.7 years) with chronic HCV-related liver disease (six cirrhotics) were evaluated for PCT levels at baseline and during the treatment course (at week 12, 24, 48 and 72) with PEG-IFNa plus RIB. Sustained virological response (SVR) was confirmed by undetectable serum HCV-RNA at the end of treatment and again 6 months after completion of treatment. RESULTS: Two patients exhibited culture-proved bacterial infections during the treatment course. Thirty-six patients (69.2%) exhibit SVR and 16 (30.8%) were non-responders. Serum PCT levels remained within normal limits (0.1-0.5 ng/mL) in all treated patients throughout the follow-up period except those two who exhibited bacterial infections during the treatment course. Virological responders exhibited significant decline of serum PCT levels over time compared to non-responders (p<0.001), even when adjusted for multiple baseline parameters (p=0.037). CONCLUSION: Serum PCT levels decline in chronic hepatitis C patients during PEG-IFNa plus RIB treatment, especially in the sustained virological responder group, while they elevate only when bacterial infections complicate the treatment course.     

Infant gaze, head, face and self-touch at 4 months differentiate secure vs. avoidant attachment at 1 year: a microanalytic approach

The study attempted to distinguish avoidant vs. secure infants at 1 year from 4-month infant behavior only, during a face-to-face play interaction with the mother. Thirty-five 4-month-old infants were coded second by second for infant gaze, head orientation, facial expression and self-touch/mouthing behavior. Mother behavior was not coded. At 1 year, 27 of these infants were classified as secure (B), and 8 as avoidant (A) attachment in the Ainsworth Strange Situation. Compared with the B infant, the future A infant spent less time paying 'focused' visual attention (a look of a minimum 2 seconds duration) to the mother's face. Only if the A infant engaged in self-touch/mouthing behavior did its focused visual attention match that of the B. Markovian t to t+1 transition matrices then showed that both for future A and for future B infants, focused visual attention on the mother constrained the movements of the head to within 60 degrees from center vis-à-vis, defining head/gaze co-ordination within an attentional-interpersonal space. However, infant maintenance of head/gaze co-ordination was associated with self-touch/mouthing behavior for the A infant but not the B. Positive affect was associated with a disruption of head/gaze co-ordination for the A but not the B. Whereas the B had more variable facial behavior, potentially providing more facial signaling for the mother, the A had more variable tactile/mouthing behavior, changing patterns of self-soothing more often. Thus, infants classified as A vs. B at 12 months showed different behavioral patterns in face-to-face play with their mothers as early as 4 months.     

SLAM: cross-species gene finding and alignment with a generalized pair hidden Markov model

Comparative-based gene recognition is driven by the principle that conserved regions between related organisms are more likely than divergent regions to be coding. We describe a probabilistic framework for gene structure and alignment that can be used to simultaneously find both the gene structure and alignment of two syntenic genomic regions. A key feature of the method is the ability to enhance gene predictions by finding the best alignment between two syntenic sequences, while at the same time finding biologically meaningful alignments that preserve the correspondence between coding exons. Our probabilistic framework is the generalized pair hidden Markov model, a hybrid of (1). generalized hidden Markov models, which have been used previously for gene finding, and (2). pair hidden Markov models, which have applications to sequence alignment. We have built a gene finding and alignment program called SLAM, which aligns and identifies complete exon/intron structures of genes in two related but unannotated sequences of DNA. SLAM is able to reliably predict gene structures for any suitably related pair of organisms, most notably with fewer false-positive predictions compared to previous methods (examples are provided for Homo sapiens/Mus musculus and Plasmodium falciparum/Plasmodium vivax comparisons). Accuracy is obtained by distinguishing conserved noncoding sequence (CNS) from conserved coding sequence. CNS annotation is a novel feature of SLAM and may be useful for the annotation of UTRs, regulatory elements, and other noncoding features.     

Expression studies of two novel in CIS-mutations identified in an intermediate case of Hunter syndrome

Hunter syndrome (Mucopolysaccharidosis type II) is a rare X-linked recessive lysosomal storage disorder caused by the deficiency of the enzyme iduronate-2-sulfatase (IDS). To date, more than 200 different mutations have been reported in the IDS gene, located on Xq27.3-q28. Here, we report two new mutations (M488I and G489A) identified in hemizygosity in an Italian Hunter patient. Their "in vitro" expression by COS 7 cells was carried out in order to evaluate their functional consequence on enzyme activity as well as their possible cumulative effect on the malfunctioning of the protein. The results obtained enabled us to confirm the G489A mutation as causative. The M488I mutation, however, could not be unequivocally considered as causing disease because of its residual activity. Although a cumulative effect of the two mutations can be excluded "in vitro," we are cautious about drawing a conclusion with regard to the possible role that the two mutations could have played "in vivo" in modulating the phenotype of the patient. Finally, the knowledge of the molecular defect of the patient has enabled us to identify the carriers, providing reliable genetic counselling to the females of the family.     

Prospective Cohort Study of Enterotoxigenic Escherichia coli Infections in Argentinean Children

In a follow-up study, enterotoxigenic Escherichia coli (ETEC) infections in 145 children from two communities located in northeastern Argentina were monitored for 2 years. The occurrence of diarrhea was monitored by weekly household visits. Of 730 fecal specimens collected, 137 (19%) corresponded to diarrheal episodes. ETEC was isolated from a significantly higher proportion of symptomatic (18.3%) than asymptomatic (13.3%) children (P = 0.04541). Individuals of up to 24 months of age were found to have a higher risk of developing ETEC diarrhea than older children (odds ratio [OR], 3.872; P = 0.00021). When the toxin profiles were considered, only heat stable enterotoxin (ST)-producing ETEC was directly associated with diarrhea (P = 0.00035). Fifty-five percent of the ETEC isolated from symptomatic children and 19% of the ETEC isolated from asymptomatic children expressed one of the colonization factors (CFs) investigated, i.e., CF antigen I (CFA/I), CFA/II, CFA/III, and CFA/IV; coli surface antigens CS7 and CS17; and putative CFs PCFO159, PCFO166, and PCFO20, indicating a clear association between diarrhea and ETEC strains that carry these factors (P = 0.0000034). The most frequently identified CFs were CFA/IV (16%), CFA/I (10%), and CS17 (9%). CFs were mostly associated with ETEC strains that produce ST and both heat-labile enterotoxin and ST. Logistic regression analysis, applied to remove confounding effects, revealed that the expression of CFs was associated with illness independently of the toxin type (OR, 4.81; P = 0.0003). When each CF was considered separately, CS17 was the only factor independently associated with illness (OR, 16.6; P = 0.0151). Most CFs (the exception was CFA/IV) fell within a limited array of serotypes, while the CF-negative isolates belonged to many different O:H types. These results demonstrate that some CFs are risk factors for the development of ETEC diarrhea.     

High and low frequency transcutaneous electrical nerve stimulation inhibits nociceptive responses induced by CO2 laser stimulation in humans

The aim of the study was to evaluate the effects of transcutaneous electric nerve stimulation (TENS) on CO(2) laser evoked potentials (LEPs) in 16 normal subjects. The volar side of the forearm was stimulated by 10 Hz TENS in eight subjects and by 100 Hz TENS in the remainder; the skin of the forearm was stimulated by CO(2) laser and the LEPs were recorded in basal conditions and soon after and 15 min after TENS. Both low and high frequency TENS significantly reduced the subjective rating of heat stimuli and the LEPs amplitude, although high frequency TENS appeared more efficacious. TENS seemed to exert a mild inhibition of the perception and processing of pain induced by laser Adelta fibres activation; the implications of these effects in the clinical employment of TENS remain to be clarified.     

Modulation of Borrelia burgdorferi stringent response and gene expression during extracellular growth with tick cells

Borrelia burgdorferi N40 multiplied extracellularly when it was cocultured with tick cells in L15BS medium, a medium which by itself did not support B. burgdorferi N40 growth. Growth of B. burgdorferi N40 in the presence of tick cells was associated with decreased production of (p)ppGpp, the stringent response global regulator, a fourfold decrease in relA/spoT mRNA, an eightfold net decrease in bmpD mRNA, and a fourfold increase in rpsL-bmpD mRNA compared to growth of B. burgdorferi in BSK-H medium. As a result, the polycistronic rpsL-bmpD mRNA level increased from 3 to 100% of the total bmpD message. These observations demonstrate that there are reciprocal interactions between B. burgdorferi and tick cells in vitro and indicate that the starvation-associated stringent response mediated by (p)ppGpp present in B. burgdorferi growing in BSK-H medium is ameliorated in B. burgdorferi growing in coculture with tick cell lines. These results suggest that this system can provide a useful model for identifying genes controlling interactions of B. burgdorferi with tick cells in vitro when it is coupled with genetic methods to isolate and complement B. burgdorferi mutants.     

Molecular cloning and characterization of actin genes from Echinococcus granulosus

An Echinococcus granulosus genomic library has been screened with a mouse β-actin cDNA probe. Two clones carrying DNA fragments of about 15 kb, possibly derived from the same genome region, have been isolated. This 15-kb genomic region includes 2 actin-related sequences (EgactI and EgactII) separated by about 4 kb. The nucleotide sequences of both genes were determined. The EgactI sequence presents no introns, but an intron of 591 bp was observed in the EgactII sequence. The genes potentially encode 375 and 376 amino-acid-long actins, respectively, with a homology of 85.3%. The deduced amino acid sequences from both genes were compared to the actin sequences from other organisms, showing similarities ranging from 63.5% to 90.6%. The nucleotide sequence of a partial actin cDNA clone has been determined. The deduced amino acids sequence showed a homology of 90.3% and 88.0% in relation to the EgactI and EgactII sequences respectively, suggesting the existence of at least one more actin gene in E. granulosus. This hypothesis is reinforced by the number of bands detected in the Southern blot analysis. Experiments based on the amplification of DNA segments using 3′-specific actin primers indicate that the EgactI gene is transcribed in protoscoleces.