Detection of anti-tumor immunity induced by laser immunotherapy

Metastatic mammary tumors in rats were treated by laser immunotherapy. Tumors injected by a laserabsorbing dye and an immunoadjuvant were irradiated non-invasively by a near-infrared laser. The successfully cured rats developed a long-term resistance to repeated tumor challenges. Using the sera from cured rats as the source of primary antibodies, immune responses induced by laser immunotherapy were observed in both cellular and molecular levels using histochemical assays and Western blot analysis.     

Molecular phylogeny of Rhacophoridae (Anura): A framework of taxonomic reassignment of species within the genera Aquixalus, Chiromantis, Rhacophorus, and Philautus

Phylogenetic relationships among representative species of the family Rhacophoridae were investigated based on 2904bp of sequences from both mitochondrial (12S rRNA, 16S rRNA, the complete t-RNA for valine), and nuclear (tyrosinase, rhodopsin) genes. Maximum parsimony, maximum likelihood, and Bayesian analyses were employed to reconstruct the phylogenetic trees. This analysis, combined with previous phylogenetic studies, serves as a framework for future work in rhacophorid systematics. The monophyly of Rhacophorus is strongly confirmed except for the species R.hainanus, which is the sister taxon to A.odontotarsus. The non-monophyly of the newly designated genus Aquixalus by Delorme et al. [Delorme, M., Dubois, A., Grosjean, S., Ohler, A., 2005. Une nouvelle classification générique et subgénérique de la tribu des Philautini (Amphibia, Anura, Ranidae, Rhacophorinae). Bull. Mens. Soc. Linn. Lyon 74, 165-171] is further confirmed. Aquixalus (Aquixalus) forms a well-supported monophyletic group within Kurixalus, whereas, Aquixalus (Gracixalus) is more closely related to species of Rhacophorus, Polypedates, and Chiromantis. Philautus as currently understood, does not form a monophyletic group. Philautus (Kirtixalus) is the sister group to the clade comprising Kurixalus and Aquixalus (Aquixalus), and more remotely related to Philautus (Philautus). Chiromantisromeri does not cluster with species of Chiromantis, and forms a basal clade to all rhacophorids save Buergeria. We propose some taxonomic changes that reflect these findings, but further revision should await more detailed studies, which include combined morphological and molecular analyses, with greater species sampling.     

Landscape composition and spatial prediction of alveolar echinococcosis in southern Ningxia, China

Background

Alveolar echinococcosis (AE) presents a serious public health challenge within China. Mass screening ultrasound surveys can detect pre-symptomatic AE, but targeting areas identified from hospital records is inefficient regarding AE. Prediction of undetected or emerging hotspots would increase detection rates. Voles and lemmings of the subfamily Arvicolinae are important intermediate hosts in sylvatic transmission systems. Their populations reach high densities in productive grasslands where food and cover are abundant. Habitat availability is thought to affect arvicoline population dynamic patterns and definitive host–intermediate host interactions. Arvicoline habitat correlates with AE prevalence in Western Europe and southern Gansu Province, China.

Methods and Findings

Xiji County, Ningxia Hui Autonomous Region, borders southern Gansu. The aims of this study were to map AE prevalence across Xiji and test arvicoline habitat as a predictor. Land cover was mapped using remotely sensed (Landsat) imagery. Infection status of 3,205 individuals screened in 2002–2003 was related, using generalised additive mixed models, to covariates: gender; farming; ethnicity; dog ownership; water source; and areal cover of mountain pasture and lowland pasture. A Markov random field modelled additional spatial variation and uncertainty. Mountain pasture and lowland pasture were associated with below and above average AE prevalence, respectively.

Conclusions

Low values of the normalised difference vegetation index indicated sub-optimality of lowland pasture for grassland arvicolines. Unlike other known endemic areas, grassland arvicolines probably did not provide the principal reservoir for Echinococcus multilocularis in Xiji. This result is consistent with recent small mammal surveys reporting low arvicoline densities and high densities of hamsters, pikas and jerboas, all suitable intermediate hosts for E. multilocularis, in reforested lowland pasture. The risk of re-emergence is discussed. We recommend extending monitoring to: southern Haiyuan County, where predicted prevalence was high; southern Xiji County, where prediction uncertainty was high; and monitoring small mammal community dynamics and the infection status of dogs.     

SLC26A4 Targeted to the Endolymphatic Sac Rescues Hearing and Balance in Slc26a4 Mutant Mice

Mutations of SLC26A4 are a common cause of human hearing loss associated with enlargement of the vestibular aqueduct. SLC26A4 encodes pendrin, an anion exchanger expressed in a variety of epithelial cells in the cochlea, the vestibular labyrinth and the endolymphatic sac. Slc26a4 ^Δ/Δ mice are devoid of pendrin and develop a severe enlargement of the membranous labyrinth, fail to acquire hearing and balance, and thereby provide a model for the human phenotype. Here, we generated a transgenic mouse line that expresses human SLC26A4 controlled by the promoter of ATP6V1B1. Crossing this transgene into the Slc26a4 ^Δ/Δ line restored protein expression of pendrin in the endolymphatic sac without inducing detectable expression in the cochlea or the vestibular sensory organs. The transgene prevented abnormal enlargement of the membranous labyrinth, restored a normal endocochlear potential, normal pH gradients between endolymph and perilymph in the cochlea, normal otoconia formation in the vestibular labyrinth and normal sensory functions of hearing and balance. Our study demonstrates that restoration of pendrin to the endolymphatic sac is sufficient to restore normal inner ear function. This finding in conjunction with our previous report that pendrin expression is required for embryonic development but not for the maintenance of hearing opens the prospect that a spatially and temporally limited therapy will restore normal hearing in human patients carrying a variety of mutations of SLC26A4.     

Monoclonal antibodies to rhamnogalacturonan I backbone

Monoclonal antibodies were raised against rhamnogalacturonan I backbone, a pectin domain, using Arabidopsis thaliana seed mucilage-derived rhamnogalacturonan I oligosaccharides—BSA conjugates. Two monoclonal antibodies, designated INRA-RU1 and INRA-RU2, selected for further characterization, were specific for the backbone of rhamnogalacturonan I, displaying no binding activity against the other pectin domains i.e. homogalacturonans, galactans or arabinans. A range of oligosaccharides was prepared by enzymatic digestion of rhamnogalacturonan I isolated from Arabidopsis thaliana seed mucilage and from sugar beet pectin, purified by low-pressure chromatography and characterized by high-performance anion-exchange chromatography and mass spectrometry. These rhamnogalacturonan I oligomers were used to characterize the binding site of the two monoclonal antibodies by competitive inhibition. Both INRA-RU1 and INRA-RU2 showed maximal binding to the [→2)-α-l-rhamnosep-(1→4)-α-d-galacturonic acid p-(1→]₇ structural motif but differed in their minimum binding requirement. INRA-RU2 required at least two disaccharide (rhamnose–galacturonic acid) repeats for the antibody to bind, while INRA-RU1 required a minimum of six disaccharide repeats. Furthermore, the binding capacity of INRA-RU1 decreased steeply as the number of disaccharide repeats go beyond seven. Each of these antibodies reacted with hairy regions isolated from sugar beet pectin. Immunofluorescence microscopy indicated that both antibodies can be readily used to detect rhamnogalacturonan I epitopes in various cell wall samples.     

Autonomous regulation of free Ca2+ concentrations in isolated plant cell nuclei: a mathematical analysis

Experiments performed on nuclei isolated from animal or plant cells have provided evidence that the nucleus generates directly specific nucleoplasmic calcium transients in response to external stimuli. Recent data suggest that isolated plant nuclei might be considered as a closed system where the nuclear concentration of free calcium would be regulated by reversible movements between the nucleoplasm and nuclear stores. We have addressed the relevance of this hypothesis by developing a mathematical approach to simulate nucleoplasmic calcium dynamics generated under various pH and temperature conditions. Here, we show that the experimental results could be explained provided that calcium channels as well as systems transporting calcium are present on the inner nuclear membrane. The putative channels would allow the entry of calcium into the nucleoplasm whereas the elusive transporting system(s) would contribute to replenish the nuclear stores. The simple proposed model is versatile enough to explain and predict autonomous changes in free calcium in the nucleoplasm of isolated plant nuclei.     

Mapping the binding site of arginine vasopressin to V1a and V1b vasopressin receptors

Starting from the 2.8-A resolution x-ray structure of bovine rhodopsin, three-dimensional molecular models of the complexes between arginine vasopressin and two receptor subtypes (V1a, V1b) have been built. Amino acid sequence alignment and docking studies suggest that four key residues (1.35, 2.65, 4.61, and 5.35) fine tune the binding of vasopressin and related peptide agonists to both receptor subtypes. To validate these predictions, a series of single or double mutants were engineered at V1a and V1b receptor subtypes and tested for their binding and functional properties. Two negatively charged amino acids at positions 1.35 and 2.65 are key anchoring residues to the Arg8 residue of arginine vasopressin. Moreover, two amino acids (V(4.61) and P(5.35)) delineating a hydrophobic subsite at the human V1b receptor are responsible for the recognition of V1b selective peptide agonists. Last, one of the latter positions (5.35) is hypothesized to explain the pharmacological species differences between rat and human vasopressin receptors for a V1b peptide agonist. Altogether these refined three-dimensional models of V1a and V1b human receptors should enable the identification of further new selective V1a and V1b agonists as pharmacological but also therapeutic tools.     

Hennekam syndrome can be caused by FAT4 mutations and be allelic to Van Maldergem syndrome

The Hennekam lymphangiectasia–lymphedema syndrome is a genetically heterogeneous disorder. It can be caused by mutations in CCBE1 which are found in approximately 25 % of cases. We used homozygosity mapping and whole-exome sequencing in the original HS family with multiple affected individuals in whom no CCBE1 mutation had been detected, and identified a homozygous mutation in the FAT4 gene. Subsequent targeted mutation analysis of FAT4 in a cohort of 24 CCBE1 mutation-negative Hennekam syndrome patients identified homozygous or compound heterozygous mutations in four additional families. Mutations in FAT4 have been previously associated with Van Maldergem syndrome. Detailed clinical comparison between van Maldergem syndrome and Hennekam syndrome patients shows that there is a substantial overlap in phenotype, especially in facial appearance. We conclude that Hennekam syndrome can be caused by mutations in FAT4 and be allelic to Van Maldergem syndrome.