Successful immunotherapy with matrix metalloproteinase-derived peptides in adjuvant arthritis depends on the timing of peptide administration

We have recently found that matrix metalloproteinases (MMPs) are targets for T-cell and B-cell reactivity in experimental arthritis. In the present article, we investigate whether modulation of MMP-specific T-cell responses could influence the course of adjuvant arthritis (AA). Lewis rats were treated nasally with MMP peptides prior to or after AA induction. Administration of the MMP-10 or the MMP-16 peptide prior to AA induction reduced the arthritic symptoms. In contrast, administration of the MMP-10 peptide after AA induction aggravated the arthritic symptoms. The present study shows the possible usefulness of MMP peptides for immunotherapy. However, a clear understanding of proper timing of peptide administration is crucial for the development of such therapies.     

The dual AngII/AVP receptor gene N119S/C163R variant exhibits sodium-induced dysfunction and cosegregates with salt-sensitive hypertension in the Dahl salt-sensitive hypertensive rat model

BACKGROUND: Essential hypertension is a prevalent complex polygenic disease and a major risk factor for cardiovascular disease, the leading cause of death in developed countries. Because of its complex and multifactorial nature, its genetic determinants still remain largely unknown. The Dahl salt-sensitive hypertensive rat model exhibits impaired sodium handling, which is hypothesized to play a key role in the pathophysiology of polygenic hypertension. Thus, genes associated with renal regulation of salt and water balance are a priori likely candidates for a causative role in hypertension pathogenesis. The functional properties and renal-specific expression of the recently characterized AngII/AVP receptor suggest a putative modulator role in tubular sodium and fluid reabsorption. Based on these observations, we investigated the potential involvement of the AngII/AVP receptor in salt-sensitive hypertension. MATERIALS AND METHODS:We performed cosegregation analysis of the AngII/AVP receptor locus with salt-sensitive hypertension in an F2 (Dahl S X Dahl salt-resistant [R]) hybrid male cohort characterized for blood pressure by radiotelemetry after 8 weeks of high salt challenge. Further molecular analysis was done to identify putative AngII/AVP receptor molecular variants that could account for the AngII/ AVP receptor involvement in salt-sensitive hypertension pathogenesis. RESULTS:The AngII/AVP receptor was mapped to rat chromosome 1, 1.7 cM centromeric to the D1Rat188 marker by radiation hybrid mapping analysis. Quantitative trait locus (QTL) analysis detected a highly significant linkage of the AngII/AVP receptor locus with high blood pressure (LRS = 13.8, p= 0.0002). Molecular characterization of the Dahl S and Dahl R AngII/AVP receptor cDNAs revealed two amino acid substitutions in the Dahl S AngII/AVP receptor (N119S, C163R) when compared to the Dahl R AngII/AVP receptor. These mutations are associated with an increased receptor affinity for both ligands (AVP and AngII) and an enhanced G(s)-coupling by the receptor resulting in increased activation of adenylate cyclase with concomitant increase in cAMP production. CONCLUSIONS: The observed molecular dysfunction in the Dahl S AngII/AVP receptor is consistent with increased tubular sodium and fluid reabsorption observed in Dahl S rats. Interestingly, the AngII/AVPr locus is within the narrowed chromosome 1 QTL region for blood pressure detected in different rat intercross linkage analyses. Altogether, the data strongly suggest that the AngII/AVP receptor is a hypertension susceptibility gene in the Dahl S rat model, as well as raises the hypothesis that it too underlies the chromosome 1 blood pressure QTL identified in other hypertension rat models.     

Theoretical investigation of the triphosphate forms of azidothymidine and thymidine

In this paper we investigate (using AM1 semi-empirical as well as HF methods at the STO-3G, 3-21G, 6-31G, 6-31G* and 6-31+G** level) the conformations, geometrical parameters, Mulliken charges, and solvation effects of the triphosphate form of AZT (AZTTP), as well as the thymidine nucleotide (dTTP) structure. Our calculated geometrical parameters and Mulliken charges, with and without solvation effects, are correlated with recent experimental results.     

Characterization and clinical manifestations of Arcanobacterium phocae infections in marine mammals stranded along the central California coast

Between 1994 and 2000, 141 Arcanobacterium phocae isolates were recovered from marine mammals that stranded along the central California coast (USA). Arcanobacterium phocae was cultured from tissue sites with abnormal discharge or evidence of inflammation in 66 California sea lions (Zalophus californianus), 50 Pacific harbor seals (Phoca vitulina richardii), 19 northern elephant seals (Mirounga angustirostris), five southern sea otters (Enhydra lutris nereis), and one common dolphin (Delphinus delphis). The overall prevalence of A. phocae among cultured stranded marine mammals was 8%. This is the first report of A. phocae in animals from the Pacific Ocean. Sequence analysis of a portion of the 16S ribosomal RNA gene confirmed recent isolates as A. phocae. Prior to phylogenetic testing and the routine use of the esculin hydrolysis and motility tests, A. phocae isolates may have been misidentified as Listeria ivanovii. Arcanobacterium phocae was commonly isolated from superficial abscesses, was often present in mixed infections, and was susceptible to all antimicrobial agents tested.     

DNA prime-protein boost immunization in monkeys: efficacy of a novel construct containing functional domains of Plasmodium cynomolgi CS and TRAP

We report the efficacy of a bimodal immunization regimen that involved priming with naked DNA (multiple doses) followed by a booster with recombinant protein in rhesus monkeys with a chimeric construct containing the N-terminus of thrombospondin-related adhesive protein and the C-terminus of circumsporozoite protein of Plasmodium cynomolgi. The vaccinated animals developed high titer antibodies against the chimeric antigen, the two components of the hybrid and the native proteins of sporozoites. The peripheral blood mononuclear cells isolated from the vaccinated animals had significant in vitro T cell proliferation activity when stimulated with the recombinant chimeric protein. Furthermore, following challenge with 1000 P. cynomolgi sporozoites, the peak and total parasitemia were significantly lower in vaccinated animals than in the control animals.     

Voltage dependence of the coupling of Ca(2+) sparks to BK(Ca) channels in urinary bladder smooth muscle

Large-conductance Ca(2+)-dependent K(+) (BK(Ca)) channels play a critical role in regulating urinary bladder smooth muscle (UBSM) excitability and contractility. Measurements of BK(Ca) currents and intracellular Ca(2+) revealed that BK(Ca) currents are activated by Ca(2+) release events (Ca(2+) sparks) from ryanodine receptors (RyRs) in the sarcoplasmic reticulum. The goals of this project were to characterize Ca(2+) sparks and BK(Ca) currents and to determine the voltage dependence of the coupling of RyRs (Ca(2+) sparks) to BK(Ca) channels in UBSM. Ca(2+) sparks in UBSM had properties similar to those described in arterial smooth muscle. Most Ca(2+) sparks caused BK(Ca) currents at all voltages tested, consistent with the BK(Ca) channels sensing approximately 10 microM Ca(2+). Membrane potential depolarization from -50 to -20 mV increased Ca(2+) spark and BK(Ca) current frequency threefold. However, membrane depolarization over this range had a differential effect on spark and current amplitude, with Ca(2+) spark amplitude increasing by only 30% and BK(Ca) current amplitude increasing 16-fold. A major component of the amplitude modulation of spark-activated BK(Ca) current was quantitatively explained by the known voltage dependence of the Ca(2+) sensitivity of BK(Ca) channels. We, therefore, propose that membrane potential, or any other agent that modulates the Ca(2+) sensitivity of BK(Ca) channels, profoundly alters the coupling strength of Ca(2+) sparks to BK(Ca) channels.     

The Basques according to polymorphic Alu insertions

Polymorphic Alu insertions provide a set of DNA markers of interest in human population genetics. Approximately 1000-2000 of these insertions have not reached fixation within the human genome. Each one of these polymorphic loci most probably resulted from a unique insertional event, and therefore all individuals possessing the insertion are related by descent not just state. In addition, the direction of mutational change is toward the gain of the Alu element at a particular locus. Therefore, the improved knowledge of both the ancestral state and the direction of mutational change greatly facilitates the analysis of population relationships. As a result, Alu insertion polymorphisms represent a significant tool for population genetic studies. In this study, polymorphic Alu insertions have been employed to ascertain phylogenetic relationships among Basque groups and worldwide populations. The Basques are considered to be a geographic isolate with a unique language and customs. They may be direct descendants of Cro-Magnon enclaves from the upper Paleolithic (38,000 to 10,000 years). The Basques are distributed among narrow valleys in northeastern Spain with little migration between them until recently. This characteristic may have had an effect on allelic frequency distributions. With the aim of studying this possible effect, we have analyzed six autosomal polymorphic Alu loci from four different sites within the Spanish Basque region in order to ascertain any genetic heterogeneity among the Basques. The results are consistent with a lack of homogeneity among these four autochthonous Basque groups.     

Generalized microsporidiosis caused by Encephalitozoon sp. in a pediatric patient with Bruton's disease

We present the case of a four-year-old boy with a history of repeated upper respiratory tract infections and pyoderma. He presented fever, seizures, inability to talk, loss of swallowing, fine tremor in the upper extremities; positive bilateral Babinski reflex and quadriparesis. The diagnosis of Bruton's disease and generalized microporidiosis was based on immunologic analysis, smear tests with chromotrope R2 stain and indirect immunofluorescense with monoclonal 3B6 antibody for Encephalitozoon species in samples of spinal fluid, bronchial and paranasal sinus aspirates and stool, which were all positive. The patient was treated with albendazol during 72 days; he left the hospital in a good condition, walking, talking and able to swallow. His laboratory test controls were negative; he is followed up in the outpatient department.