Effect of dexamethasone and hydrocortisone on the course of superovulation in cattle

The effect of hydrocortisone and dexamethasone on superovulation was examined in 12 cows. On the day PMSG was given, each animal received either the first of five daily doses of 250 mg succinate hydrocortisone or one injection of 30 mg dexamethasone. In the 48-hr interval between the injection of PMSG and PGF(2)alpha, the concentration of progesterone rose from 6.97 to 10.22 ng/ml in the experimental groups and only to about 2.8 ng/ml in the control group. In the following days progesterone increased even more, from 15.7 to 26.0 ng/ml seven days after estrus in the experimental group and to 19.25 ng/ml in the control group. The group which received dexamethasone had an average of 4.7 corpora lutea and one embryo flushed per animal. The hydrocortisone group had an average of 2.5 corpora lutea and one cow had two embryos. The control group had 6.2 corpora lutea and 5.2 embryos per animal.     

Cryopreservation of mammalian ova and embryos by vitrification

Vitrification is a new approach to oocyte and embryo cryoconservation. It consists in the solidification of a solution caused not by crystallization, but by a drastic increase in viscosity during cooling. The application of this approach to cryoconservation of oocytes and embryos of different species depends upon the development of proper procedures and non-toxic media. From the technical point of view, the vitrification method is simple and relatively easily applicable under field conditions. The authors review the current procedures applied to oocytes and embryos of laboratory and farm animals.     

Factors affecting the survival of one- and two-cell rabbit embryos cryopreserved by vitrification

The effects of equilibration time, glycerol (GLY), and 1,2-propanediol (PROH) concentration, and of vitrification and sucrose solution on the viability of 1- and 2-cell rabbit embryos were investigated. After collection, the embryos were equilibrated for 5 or 10 minutes in phosphate buffered saline (PBS) containing 10% GLY-20% PROH and were exposed for 30 seconds at 4 degrees C or were exposed and vitrified in one of two vitrification solutions 35% GLY-35% PROH or 20% GLY-50% PROH. The in vitro survival rates of 1-cell embryos equilibrated for both 5 and 10 minutes were lower (34.0 and 48.0%, respectively) than those of 2-cell embryos (78.8 and 68.5%, respectively; P<0.01). No differences were noted in the viability of embryos exposed to the 2 vitrification solutions. Following vitrification in a mixture of 35% GLY-35% PROH, the survival rates of 1- and 2-cell embryos were 18.3 and 13.7% and 19.6 and 10.4% for 5 and 10 minutes of equilibration, respectively. The survival rates of 1- and 2-cell embryos vitrified in a solution of 20% GLY-50% PROH were 25.7 and 35.4% and 26.2 and 21.3% for 5 and 10 minutes of equilibration, respectively. The survival rates of 1-and 2-cell embryos stored in 1M sucrose solution were 63.8 and 84.0%, respectively. In conclusion, the viability of vitrified 1- and 2-cell rabbit embryos was reduced as a consequence of their equilibration before vitrification, the exposure to vitrification solution and the dilution in a sucrose solution rather than of the vitrification process itself.     

Collagenase-3 (MMP-13) deficiency protects C57BL/6 mice from antibody-induced arthritis

Introduction

Matrix metalloproteinases (MMPs) are important in tissue remodelling. Here we investigate the role of collagenase-3 (MMP-13) in antibody-induced arthritis.

Methods

For this study we employed the K/BxN serum-induced arthritis model. Arthritis was induced in C57BL/6 wild type (WT) and MMP-13-deficient (MMP-13^–/–) mice by intraperitoneal injection of 200 μl of K/BxN serum. Arthritis was assessed by measuring the ankle swelling. During the course of the experiments, mice were sacrificed every second day for histological examination of the ankle joints. Ankle sections were evaluated histologically for infiltration of inflammatory cells, pannus tissue formation and bone/cartilage destruction. Semi-quantitative PCR was used to determine MMP-13 expression levels in ankle joints of untreated and K/BxN serum-injected mice.

Results

This study shows that MMP-13 is a regulator of inflammation. We observed increased expression of MMP-13 in ankle joints of WT mice during K/BxN serum-induced arthritis and both K/BxN serum-treated WT and MMP-13^–/– mice developed progressive arthritis with a similar onset. However, MMP-13^–/– mice showed significantly reduced disease over the whole arthritic period. Ankle joints of WT mice showed severe joint destruction with extensive inflammation and erosion of cartilage and bone. In contrast, MMP-13^–/– mice displayed significantly decreased severity of arthritis (50% to 60%) as analyzed by clinical and histological scoring methods.

Conclusions

MMP-13 deficiency acts to suppress the local inflammatory responses. Therefore, MMP-13 has a role in the pathogenesis of arthritis, suggesting MMP-13 is a potential therapeutic target.     

Modeling the Structure of RNA Molecules with Small-Angle X-Ray Scattering Data

We propose a novel fragment assembly method for low-resolution modeling of RNA and show how it may be used along with small-angle X-ray solution scattering (SAXS) data to model low-resolution structures of particles having as many as 12 independent secondary structure elements. We assessed this model-building procedure by using both artificial data on a previously proposed benchmark and publicly available data. With the artificial data, SAXS-guided models show better similarity to native structures than ROSETTA decoys. The publicly available data showed that SAXS-guided models can be used to reinterpret RNA structures previously deposited in the Protein Data Bank. Our approach allows for fast and efficient building of de novo models of RNA using approximate secondary structures that can be readily obtained from existing bioinformatic approaches. We also offer a rigorous assessment of the resolving power of SAXS in the case of small RNA structures, along with a small multimetric benchmark of the proposed method.     

Telocytes: new insight into the pathogenesis of gallstone disease

The major mechanisms of gallstone formation include biliary cholesterol hypersecretion, supersaturation and crystallization, mucus hypersecretion, gel formation and bile stasis. Gallbladder hypomotility seems to be a key event that triggers the precipitation of cholesterol microcrystals from supersaturated lithogenic bile. Telocytes, a new type of interstitial cells, have been recently identified in many organs, including gallbladder. Considering telocyte functions, it is presumed that these cells might be involved in the signalling processes. The purpose of this study was to correlate the quantity of telocytes in the gallbladder with the lithogenicity of bile. Gallbladder specimens were collected from 24 patients who underwent elective laparoscopic cholecystectomy for symptomatic gallstone disease. The control group consisted of 25 consecutive patients who received elective treatment for pancreatic head tumours. Telocytes were visualized in paraffin sections of gallbladders with double immunofluorescence using primary antibodies against c‐Kit (anti‐CD117) and anti‐mast cell tryptase. Cholesterol, phospholipid and bile acid levels were measured in gallbladder bile. The number of telocytes in the gallbladder wall was significantly lower in the study group than that in the control group (3.03 ± 1.43 versus 6.34 ± 1.66 cell/field of view in the muscularis propria, P < 0.001) and correlated with a significant increase in the cholesterol saturation index. The glycocholic and taurocholic acid levels were significantly elevated in the control subjects compared with the study group. The results suggest that bile composition may play an important role in the reduction in telocytes density in the gallbladder.     

Copper binding to chicken and human prion protein amylodogenic regions: Differences and similarities revealed by Ni as a diamagnetic probe

Both human (h) and chicken (Ch) prion proteins (PrP) bind copper ions within the so called “tandem repeat” N-terminal region. Outside this region, hPrP possesses two additional copper binding sites, localized at His-96 and His-111 in the so called “amylodogenic” or neurotoxic region (residues 91-126). Also ChPrP possesses a similar region (ChPrP_105−140) containing two His (His-110 and His-124) and an identical hydrophobic tail of 15 amino acids rich in Ala and Gly. The copper binding abilities within such region of ChPrP were investigated by NMR, CD and potentiometry using Ni²⁺ as diamagnetic probe. The formation of diamagnetic metal complexes allowed to monitor the chemical shift and signal intensity variations and to determine the structural and kinetic features of the His-110 and His-124 metal binding sites. Finally a comparison between the hPrP and ChPrP metal binding abilities was performed. We found that the two prion proteins exhibited different copper and nickel preferences with the favoured metal binding sites localized at opposite His: His-110 for ChPrP, and His-111 for hPrP.     

Seroprevalence of <Emphasis Type="Italic">Borrelia burgdorferi</Emphasis> sensu lato and <Emphasis Type="Italic">Anaplasma phagocytophilum</Emphasis> in Danish horses

Background

Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum are able to infect horses. However, the extend to which Danish horses are infected and seroconvert due to these two bacteria is unknown. The aim of the present study was to evaluate the seroprevalence of B. burgdorferi sensu lato and A. phagocytophilum in Danish horses.

Methods

A total of 390 blood samples collected from all major regions of Denmark and with a geographical distribution corresponding to the density of the Danish horse population were analyzed. All samples were examined for the presence of antibodies against B. burgdorferi sensu lato and A. phagocytophilum by the use of the SNAP^®4DX ^® ELISA test.

Results

Overall, 29.0% of the horses were seropositive for B. burgdorferi sensu lato whereas 22.3% were seropositive for A. phagocytophilum.

Conclusions

Antibodies against B burgdorferi sensu lato and A. phagocytophilum are commonly found among Danish horses thus showing that Danish horses are frequently infected by these organisms.