Two L1-peptides are excellent tools for serological detection of HPV-associated cervical carcinoma lesions

A persistent high risk human papillomavirus (HR-HPV) infection causes cervical intraepithelial lesions and cervical carcinoma. There is evidence that detecting anti-L1 antibodies could be successfully used for discriminating between cervical lesion patients and women having normal cytology. It was found that peptides 18283 (55PNNNKILVPKVSGLQYRVFR74) and 18294 (284LYIKGSGSTANLASSNYFPT300) from the L1-surface exposed regions were specifically recognised by antibodies from the cervical lesion patient sera. These peptides were tested against 165 womens' normal cytology sera and 148 cervical lesion or cervical cancer patients' sera. Less than 3.6% of women's normal cytology sera recognised peptides 18283 or 18294; on the contrary, 91% to 96% of the cervical lesion (CIN I to CIN III) or cervical cancer patient sera recognised peptides 18283 and 18294. These data show that anti-peptide 18283 and 18294 antibodies in the patients' sera are strongly associated with the presence of HR-HPV associated cervical lesions, showing 92-97% sensitivity and 89-95% specificity in recognising precancerous and cervical cancer patients. These two peptides could be excellent tools for use in large-scale serological screening of women populations at risk of developing cervical carcinoma.     

Defective CD3zeta chain expression in Herpesvirus saimiri (HVS)-derived T-cell lines in gastric adenocarcinoma

Low expression of the CD3zeta chain has been reported in patients with cancer and it has been suggested that tumor-derived factors are involved in its downregulation. The expression of CD3zeta chain was measured in T-cell lines from patients with gastric adenocarcinoma and healthy volunteers and grown in vitro for several months and, hence, in the absence of any tumor-derived factors. T-cell lines of mucosal origin were obtained by Herpesvirus saimiri transformation from gastric cancer patients. The expression of CD3zeta and CD3epsilon was measured by flow cytometry and Western-blot analysis. Calcium mobilization and apoptosis rate were also measured. The levels of CD3zeta, but not CD3epsilon, chain on the cell surface were significantly reduced in T-cell lines derived from patients with gastric cancer when cultured in the absence of IL-2. Western-blot analysis of total cell extracts or lipid raft fractions confirmed this finding. Calcium mobilization, a measure of signal transduction, was reduced in T cell lines from patients with gastric cancer. We conclude that T cells from patients with cancer express lower levels of CD3zeta. This downregulation is not caused by a direct effect of tumor-derived factors but, rather, it appears to be inherent to the patient cells. The low CD3zeta expression would render T lymphocytes unable to control the growth of tumor cells.     

Association between reduced bronchodilatory effect of deep inspiration and loss of alveolar attachments

Background

We have previously shown that the bronchodilatory effect of deep inspiration is attenuated in individuals with COPD. This study was designed to investigate whether the impairment in this effect is associated with loss of alveolar attachments.

Methods

We measured deep inspiration (DI)-induced bronchodilation in 15 individuals with and without COPD (67 ± 2.2 yrs of age, mean ± SEM) undergoing lobar resection for peripheral pulmonary nodule. Prior to surgery, we measured TLCO and determined the bronchodilatory effect of deep inspiration after constricting the airways with methacholine. The number of destroyed alveolar attachments, as well as airway wall area and airway smooth muscle area, were determined in tumor-free, peripheral lung tissue.

Results

The bronchodilatory effect of deep inspiration correlated inversely with the % destroyed attachments (r = -0.51, p = 0.05) and directly with the airway smooth muscle area (r = 0.59, p = 0.03), but not with the total wall area (r = 0.39, p = 0.15).

Conclusion

We postulate that attenuation of airway stretch due to loss of alveolar attachments contributes to the loss of the bronchodilatory effect of lung inflation in COPD.     

Evidence that 17alpha-estradiol is biologically active in the uterine tissue: Antiuterotonic and antiuterotrophic action

Background  

17alpha-Estradiol has been considered as the hormonally inactive isomer of 17beta-estradiol. Recently, nongenomic (smooth muscle relaxation) and genomic (light estrogenic activity) effects of 17alpha-estradiol have been reported, but no reports have yet determined its possible antiestrogenic activity. Therefore, this study investigated: the nongenomic action of 17alpha-estradiol on uterine contractile activity and its potential agonist-antagonist activity on uterine growth.     

Production and characterization of a noncytotoxic deletion variant of the Aspergillus fumigatus allergen Aspf1 displaying reduced IgE binding

Aspergillus fumigatus is responsible for many allergic respiratory diseases, the most notable of which - due to its severity - is allergic bronchopulmonary aspergillosis. Aspf1 is a major allergen of this fungus: this 149-amino acid protein belongs to the ribotoxin family, whose best characterized member is alpha-sarcin (EC 3.1.27.10). The proteins of this group are cytotoxic ribonucleases that degrade a unique bond in ribosomal RNA impairing protein biosynthesis. Aspf1 and its deletion mutant Aspf1Delta(7-22) have been produced as recombinant proteins; the deleted region corresponds to an exposed beta-hairpin. The conformation of these two proteins has been studied by CD and fluorescence spectroscopy. Their enzymatic activity and cytotoxicity against human rhabdomyosarcoma cells was also measured and their allergenic properties have been studied by using 58 individual sera of patients sensitized to Aspergillus. Aspf1Delta(7-22) lacks cytotoxicity and shows a remarkably reduced IgE reactivity. From these studies it can be concluded that the deleted beta-hairpin is involved in ribosome recognition and is a significant allergenic region.     

The seventh transmembrane domains of the delta and kappa opioid receptors have different accessibility patterns and interhelical interactions

We applied the substituted cysteine accessibility method (SCAM) to map the residues of the transmembrane helices (TMs) 7 of delta and kappa opioid receptors (deltaOR and kappaOR) that are on the water-accessible surface of the binding-site crevices. A total of 25 consecutive residues (except C7.38) in the TMs 7 were mutated to Cys, one at a time, and each mutant was expressed in HEK 293 cells. Most mutants displayed similar binding affinity for [(3)H]diprenorphine, an antagonist, as the wild types. Pretreatment with (2-aminoethyl)methanethiosulfonate (MTSEA) inhibited [(3)H]diprenorphine binding to eight deltaOR and eight kappaOR mutants. All mutants except deltaOR L7.52(317)C were protected by naloxone from the MTSEA effect, indicating that the side chains of V7.31(296), A7.34(299), I7.39(304), L7.41(306), G7.42(307), P7.50(315), and Y7.53(318) of deltaOR and S7.34(311), F7.37(314), I7.39(316), A7.40(317), L7.41(318), G7.42(319), Y7.43(320), and N7.49(326) of kappaOR are on the water-accessible surface of the binding pockets. Combining the SCAM data with rhodopsin-based molecular models of the receptors led to the following conclusions. (i) The residues of the extracellular portion of TM7 predicted to face TM1 are sensitive to MTSEA in kappaOR but are not in deltaOR. Thus, TM1 may be closer to TM7 in deltaOR than in kappaOR. (ii) MTSEA-sensitive mutants start at position 7.31(296) in deltaOR and at 7.34(311) in kappaOR, suggesting that TM7 in deltaOR may have an additional helical turn (from 7.30 to 7.33). (iii) There is a conserved hydrogen-bond network linking D2.50 of the NLxxxD motif in TM2 with W6.48 of the CWxP motif in TM6. (iv) The NPxxY motif in TM7 interacts with TM2, TM6, and helix 8 to maintain receptors in inactive states. To the best of our knowledge, this represents the first such comparison of the structures of two highly homologous GPCRs.     

Quantification of yessotoxin using the fluorescence polarization technique and study of the adequate extraction procedure

Yessotoxin (YTX) is a polycyclic ether toxin produced by phytoplanktonic microalgae from the group of dinoflagellates. It has been shown that YTX increases the 3',5'-cyclic nucleotide phosphodiesterases (PDEs) activity and that there is a binding between these proteins and the toxin. Fluorescence polarization (FP) is a spectroscopic technique that can be used to study the interactions between molecules. It is based on exciting a fluorescent molecule with plane-polarized light and measuring the polarization degree of the emitted light. In this study, the FP is applied to the study of the interaction between YTX and phosphodiesterases I and II (PDE I and II). The phosphodiesterases are labeled with a reactive succinimidyl esther of carboxyfluorescein, and the FP of the protein-dye conjugate is measured when the YTX concentration in the medium increases. The results show that in both cases the fluorescence polarization of the conjugates decreases when they bind to YTX. For the PDE I, it is possible to draw a Gaussian curve or a straight line that relates the two variables (FP and YTX concentration). The concentration of this toxin in a spiked mussel extract (which contains the conjugate) can be quantified measuring its FP and using the equations of those lines. Different extraction methods are tried in this study, and those that can be used to obtain an appropriate mussel extract to be quantified with this technique are determined.     

Disentangling extrinsic from intrinsic factors in disease dynamics: a nonlinear time series approach with an application to cholera

Alternative explanations for disease and other population cycles typically include extrinsic environmental drivers, such as climate variability, and intrinsic nonlinear dynamics resulting from feedbacks within the system, such as species interactions and density dependence. Because these different factors can interact in nonlinear systems and can give rise to oscillations whose frequencies differ from those of extrinsic drivers, it is difficult to identify their respective contributions from temporal population patterns. In the case of disease, immunity is an important intrinsic factor. However, for many diseases, such as cholera, for which immunity is temporary, the duration and decay pattern of immunity is not well known. We present a nonlinear time series model with two related objectives: the reconstruction of immunity patterns from data on cases and population sizes and the identification of the respective roles of extrinsic and intrinsic factors in the dynamics. Extrinsic factors here include both seasonality and long-term changes or interannual variability in forcing. Results with simulated data show that this semiparametric method successfully recovers the decay of immunity and identifies the origin of interannual variability. An application to historical cholera data indicates that temporary immunity can be long-lasting and decays in approximately 9 yr. Extrinsic forcing of transmissibility is identified to have a strong seasonal component along with a long-term decrease. Furthermore, noise appears to sustain the multiple frequencies in the long-term dynamics. Similar semiparametric models should apply to population data other than for disease.     

Resonant mirror biosensor detection method based on yessotoxin-phosphodiesterase interactions

Yessotoxin (YTX) is a generic name for a group of lipophilic compounds recently discovered and chemically characterized. Association measurements were done in a resonant mirror biosensor. The instrument detects changes in the refractive index and/or thickness occurring within a few hundred nanometers form the sensor surface where a molecule is attached. We used aminosilane surfaces where phosphodiesterase 3',5'-cyclic-nucleotide-specific from bovine brain (PDEs) was immobilized. Over this immobilized ligand different amounts of YTX were added and typical association curve profiles were observed. These association curves fit a pseudo-first-order kinetic equation where the apparent association rate constant (k(on)) can be calculated. The value of this constant increases with YTX concentration. From the representation of k(on) versus YTX concentration we obtained the association rate constant (k(ass)) 248+/-40 M(-1)s(-1) and the dissociation rate constant (k(diss)) 9.36 x 10(-4)+/-1.72 x 10(-4)s(-1). From these values the kinetic equilibrium dissociation constant (K(D)) for YTX-PDEs association can be calculated. The value of this last constant is 3.74 x 10(-6)+/-8.25 x 10(-8)M YTX. The PDE-YTX association was used as a method suitable for determination of the toxin concentration in a shellfish sample. The assay had sufficient sensitivity and can be used on simple shellfish extracts.