Endocrine response in rabbits immunized with native versus deglycosylated porcine zona pellucida antigens

Previous studies evaluating porcine zona pellucida antigens for immunocontraceptive purposes have in some cases revealed altered ovarian function in association with antibody response. This study was undertaken in an attempt to identify zona immunogens that do not cause adverse endocrine effects. To this end, we investigated the effects of highly purified preparations of native and deglycosylated pig zona pellucida antigens on ovarian function and immune response in the rabbit. Thirty female rabbits were immunized, 5 per group, with 100 micrograms each of either 1) SIZP, solubilized isolated zonae pellucidae; 2) ZP3, a purified porcine zona preparation containing the two principle glycoproteins, ZP3 alpha and ZP3 beta, endo-beta-galactosidase-digested ZP3 glycoproteins (approximately 30% deglycosylated) termed 3) ZP3 alpha/EBGD and 4) ZP3 beta/EBGD; and chemically deglycosylated ZP3 alpha and ZP3 beta (greater than or equal to 92% deglycosylated), termed 5) ZP3 alpha/DG and 6) ZP3 beta/DG. Rabbits injected with saline (n = 2) or Freund's adjuvant alone (n = 3) served as controls. Serum LH, FSH, estradiol, and progesterone were measured at 5-day intervals during seven 20-day cycles of hCG-induced pseudopregnancy over 42 wk. Anti-ZP3 titers, determined by RIA, developed in all treatment groups and correlated directly with carbohydrate content. Animals immunized with SIZP, ZP3, and ZP3 beta/EBGD showed a significant elevation of LH and FSH and a significant decline of peak progesterone levels by the fourth pseudopregnancy cycle. In contrast, animals immunized with ZP3 alpha/EBGD, ZP3 alpha/DG, and ZP3 beta/DG showed no significant elevations of gonadotropins and continued to display cyclic progesterone secretion in response to hCG.(ABSTRACT TRUNCATED AT 250 WORDS)     

Spatial properties of receptive fields of mechanosensitive primary afferent nerve fibers

Tactile sensation is rich and varied, requiring input from a variety of mechanoreceptors whose spatiotemporal aspects deserve careful study. Recent data for virtually every class of sensitive mechanoreceptor have revealed spatial inhomogeneities in sensitivity reflecting the distribution of sense organ terminals and the complexity of gradients in the complex spatial organization of receptive fields. Controlled surface parallel stimulation provides a means for examining sensitivity in a manner that may shed light on active tactile exploration and allow quantitative analysis of orientation, direction, and velocity properties underlying some aspects of feature extraction by the central nervous system.     

Large, rapidly evolving intergenic spacers in the mitochondrial DNA of the salamander family Ambystomatidae (Amphibia: Caudata)

We report the presence, in the mitochondrial DNA (mtDNA) of all of the sexual species of the salamander family Ambystomatidae, of a shared 240- bp intergenic spacer between tRNAThr and tRNAPro. We place the intergenic spacer in context by presenting the sequence of 1,746 bp of mtDNA from Ambystoma tigrinum tigrinum, describe the nucleotide composition of the intergenic spacer in all of the species of Ambystomatidae, and compare it to other coding and noncoding regions of Ambystoma and several other vertebrate mtDNAs. The nucleotide substitution rate of the intergenic spacer is approximately three times faster than the substitution rate of the control region, as shown by comparisons among six Ambystoma macrodactylum sequences and eight members of the Ambystoma tigrinum complex. We also found additional inserts within the intergenic spacers of five species that varied from 87-444 bp in length. The presence of the intergenic spacer in all sexual species of Ambystomatidae suggests that it arose at least 20 MYA and has been a stable component of the ambystomatid mtDNA ever since. As such, it represents one of the few examples of a large and persistent intergenic spacer in the mtDNA of any vertebrate clade.      

Environmental and management determinants of vegetation state on protected areas in the eastern Lowveld of South Africa

Principal driving determinants (rainfall, geology, soil, tree density and canopy cover, animal numbers and feeding classes, and fire) of vegetation structure and function in the Lowveld savanna in South Africa were grouped for a 7‐year period to establish their influence on the limiting herbaceous layer. Grass type, abundance and cover were examined (450 sites; approximately 4000 km²). Using ordination, the variation and differences in the herbaceous‐response variables viz. perennial composition and cover allowed for the broad environmental grouping of areas of similar ecological potential. We demonstrate that areas of higher ecological potential carried higher densities of large herbivores without detrimentally affecting herbaceous composition and cover. The results have implications for land users and policy makers in terms of setting animal stocking density guidelines.     

Short AntiMicrobial Peptides (SAMPs) as a class of extraordinary promising therapeutic agents

The emergence of multidrug resistant bacteria has a direct impact on global public health because of the reduced potency of existing antibiotics against pathogens. Hence, there is a pressing need for new drugs with different modes of action that can kill microorganisms. Antimicrobial peptides (AMPs) can be regarded as an alternative tool for this purpose because they are proven to have therapeutic effects with broad‐spectrum activities. There are some hurdles in using AMPs as clinical candidates such as toxicity, lack of stability and high budgets required for manufacturing. This can be overcome by developing shorter and more easily accessible AMPs, the so‐called S hort A nti M icrobial P eptides (SAMPs) that contain between two and ten amino acid residues. These are emerging as an attractive class of therapeutic agents with high potential for clinical use and possessing multifunctional activities. In this review we attempted to compile those SAMPs that have exhibited biological properties which are believed to hold promise for the future. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.     

Plasma membrane Ca2+-ATPase expression during colon cancer cell line differentiation

The differentiation of colon cancer cell lines is associated with changes in calcium homeostasis. Concomitantly there are changes in the expression of some calcium transporters and G-protein-coupled receptors, which are capable of altering cytosolic-free calcium levels. Recent studies associate alterations in calcium transporter expression with tumourigenesis, such as changes in specific isoforms of the plasma membrane calcium ATPase (PMCA) in breast cancer cell lines. In this study, we examined the expression of PMCA isoforms in the HT-29 colon cancer cell line using two methods of differentiation (sodium butyrate-mediated and spontaneous post-confluency induced differentiation). Our studies show that differentiation of HT-29 colon cancer cells is associated with the up-regulation of the PMCA isoform PMCA4 but no significant alteration in PMCA1. These results suggest that PMCA4 may be important and have a specific role in colon cells as well as being significant in colon cancer tumourigenesis.     

Characterisation of inosine monophosphate dehydrogenase expression during retinal development: differences between variants and isoforms

In mammals there are two ubiquitous, catalytically indistinguishable isoforms of inosine monophosphate dehydrogenase and mutations in the type I isoform, but not type II, cause retina-specific disorders. We have characterised the spatio-temporal expression of these proteins during development of the rat retina and performed functional investigations of the recently described retinal type I variants. Inosine monophosphate dehydrogenase was present in all immature cells throughout the retina during embryonic and neonatal development. Following eye opening and cell differentiation its distribution was restricted to the photoreceptors and bipolar cells, becoming prominent in Müller cells with aging. Type II was present in early, developing retinae whilst type I was undetectable. An isoform switch occurred around P10, after which the type I variants, type Ialpha and type Igamma, were the major forms. Functional investigations indicate type Igamma has greater catalytic activity compared with other variants and isoforms. Finally, all forms of type I show an increased propensity to form intracellular macrostructures compared to type II and these structures appear to be regulated in response to changing intracellular GTP levels. Collectively these data demonstrate that (i) type I does not play a role in early retinal development, (ii) type Igamma has greater activity and (iii) there are differences between type I and type II isoforms. These observations are consistent with the aetiology of retinitis pigmentosa and raise the possibility that programmed expression of specific inosine monophosphate dehydrogenase proteins may have arisen to meet the requirements of the cellular environment.