Spatio-temporal distribution and characterisation of phytoplankton populations coupled with abiotic and biotic changes in landfill leachate treatment basins (Etuffont, Belfort, France)

The quantitative distribution of dominant phytoplankton species was carried out in the stabilisation ponds of Etueffont landfill leachate (Belfort, France) from May 1998 to May 1999. The results showed maximum phytoplankton abundance in the last lagooning basin during summer 1998, that coincided with an increase in temperature and better leachate quality. In addition, the phytoplankton was dominated by Euglenophytes species Phacus sp. and Euglena sp. known to resist constraints induced by the highly polluted aquatic environments. An improve in water quality of the last basins translated into a shift in species composition with the substitution of the Bacillariophyceae (Stephanodiscus dubius) by the Chlorophyceae (Coelastrum sp.).     

Association of increased serum acute‐phase protein concentrations with reproductive performance in dairy cows with postpartum metritis

Background: It is known that quantification of bovine acute‐phase proteins could routinely provide early diagnostic and prognostic information for monitoring herd health status. Objective: The aim of this study was to test the hypothesis that haptoglobin (Hp) and serum amyloid A (SAA) have the potential for indicating uterine infection, mainly due to subclinical endometritis, which can seriously influence the reproductive performance in dairy cows. Methods: A total of 264 serum samples were collected from 24 Holstein dairy cows at defined intervals from 1 week prepartum to 6 months postpartum. Clinically healthy animals (Group 1, n=6) were compared with 24 animals having acute puerperal metritis (Group 2, n=18) and with concentrations obtained from healthy heifers (baseline values, n=10). The concentrations of serum Hp and SAA were measured using a hemoglobin‐binding assay and Western blot analysis, respectively. Reproductive performance was assessed as the number of days open and the conception rate at the end of the study. Results: Upper cut‐off values for Hp and SAA concentrations in heifers were 130.9 μg/L and 51.9 μg/mL, respectively. Hp concentrations in Group 2 were significantly higher than those in Group 1 at all time points (P<.001). Additionally, among the successfully pregnant animals, the number of days open was significantly higher in 6 cows with Hp >130.9 μg/mL (median=316 days) than in 11 cows with Hp ≤130.9 μg/mL (median=120 days) (P=.0024). Conclusions: Serum Hp and SAA concentrations can be used to recognize uterine infection in postpartum cows. The association between elevated Hp values and number of days open suggests Hp may also be a useful indicator of poor prognosis for reproductive performance.     

Jejunojejunal Intussusception and Colonic Impaction in a 12-Day-Old Orphan Foal

A 12-day-old, 14.4-kg, female foal of Australian Miniature Pony breed was presented at the National Chung Hsing University Veterinary Medicine Teaching Hospital, Taiwan, with a history of weakness of 2 days’ duration. The mare died of unknown cause on the previous day. Abnormal findings during physical examination included an estimated dehydration of 3 to 5%, dark red oral mucous membranes, elevated heart and respiratory rates, stiffened feces, and absence of intestinal motility on auscultation. Continual nursing care was followed by intravenous fluid therapy and nonsteroidal anti-inflammatory drug and antibiotic treatment. The foal's condition deteriorated rapidly, and feeding was refused. Subsequently, she developed signs of pyrexia and panting. In spite of oxygen supplement, she died 18 hours after admission. Postmortem examination revealed the presence of a jejunojejunal intussusception, 20 cm in length; a torsion of jejunum proximal to the intussusception also was noted. An ulcerative lesion, 3 cm in diameter, was found on the mucosa of duodenum. Large amounts of sand, coat hair, and hay mantling in bloody discharge were observed in a colonic impaction. That it was an acute case was evident by the involvement of intussusception and ulceration, indicating desquamation of the necrotic epithelial cells with edema and distinct infiltration of neutrophils. These results suggested that a practical management strategy for nursing an orphan foal should be performed to avoid a similar case in the future.     

The antioxidant system of seminal fluid during in vitro storage of sterlet <Emphasis Type="Italic">Acipenser ruthenus</Emphasis> sperm

The role of the seminal fluid antioxidant system in protection against damage to spermatozoa during in vitro sperm storage is unclear. This study investigated the effect of in vitro storage of sterlet Acipenser ruthenus spermatozoa together with seminal fluid for 36 h at 4 °C on spermatozoon motility rate and curvilinear velocity, thiobarbituric acid reactive substance level, and components of enzyme and non-enzyme antioxidant system (superoxide dismutase and catalase activity and uric acid concentration) in seminal fluid. Spermatozoon motility parameters after sperm storage were significantly decreased, while the level of thiobarbituric acid reactive substances, activity of superoxide dismutase and catalase, and uric acid concentration did not change. Our findings suggest that the antioxidant system of sterlet seminal fluid is effective in preventing oxidative stress during short-term sperm storage and prompt future investigations of changes in spermatozoon homeostasis and in spermatozoon plasma membrane structure which are other possible reasons of spermatozoon motility deterioration upon sperm storage.     

Serum haptoglobin concentration in cattle

To obtain a basal concentration of serum Haptoglobin (Hp) in cattle in Taiwan, Hp concentrations were measured from serum samples collected from 10 healthy heifers, every week for one year. The values were also compared with those collected from 15 cows diagnosed with postpartum metritis. The heifers were successfully impregnated by artificial insemination six months after the tests. Hp concentrations were also measured in the serum collected from 11 other cows within 3 weeks after parturition. The Hp assay developed in this study gave a good correlation (r=0.893)with Western blotting. The Hp concentration of 454 serum samples from the 10 heifers had a mean value of 83.6 +/- 34.1 mg/l, and there was no significant difference among individual heifers. The basal value of Hp in heifers was calculated as less than 73.6 mg/l. No significant difference in Hp concentration was observed among the 10 heifers during cold and warm seasons (19.8 +/- 2.2 degrees C vs 27.3 +/- 1.4 degrees C), or before and after pregnancy. The mean serum Hp concentration from cows suffering from postpartum reproductive disorders was 1133.5 +/- 627.1 mg/l, which was significantly greater than the serum of healthy heifers and postpartum cows (104.6 +/- 61.0 mg/l) (P<0.05). These results demonstrate that Hp concentration may be a useful indicator for cows with postpartum reproductive disorders.     

Effects of ions on the motility of fresh and demembranate spermatozoa of common carp (Cyprinus carpio) and paddlefish (Polyodon spathula)

In the present study was summarize the factors activating and/or inhibiting the motility of intact and/or demembranated spermatozoa of common carp and paddlefish as teleostean and chondrostean models using methods of sperm demembranation. The movement of spermatozoa of cyprinids species, common carp, is influenced by osmotic pressure or high concentration of ions. The movements of spermatozoa of chrondrostean species, paddlefish, are under reciprocal control by the concentration of K⁺ and Ca²⁺.     

Early infections by myxoma virus of young rabbits (Oryctolagus cuniculus) protected by maternal antibodies activate their immune system and enhance herd immunity in wild populations

The role of maternal antibodies is to protect newborns against acute early infection by pathogens. This can be achieved either by preventing any infection or by allowing attenuated infections associated with activation of the immune system, the two strategies being based on different cost/benefit ratios. We carried out an epidemiological survey of myxomatosis, which is a highly lethal infectious disease, in two distant wild populations of rabbits to describe the epidemiological pattern of the disease. Detection of specific IgM and IgG enabled us to describe the pattern of immunity. We show that maternal immunity attenuates early infection of juveniles and enables activation of their immune system. This mechanism associated with steady circulation of the myxoma virus in both populations, which induces frequent reinfections of immune rabbits, leads to the maintenance of high immunity levels within populations. Thus, myxomatosis has a low impact, with most infections being asymptomatic. This work shows that infection of young rabbits protected by maternal antibodies induces attenuated disease and activates their immune system. This may play a major role in reducing the impact of a highly lethal disease when ecological conditions enable permanent circulation of the pathogen.     

Enhanced CpG mutability and tumorigenesis in MBD4-deficient mice

The mammalian protein MBD4 contains a methyl-CpG binding domain and can enzymatically remove thymine (T) or uracil (U) from a mismatched CpG site in vitro. These properties suggest that MBD4 might function in vivo to minimize the mutability of 5-methylcytosine by removing its deamination product from DNA. We tested this hypothesis by analyzing Mbd4-/- mice and found that the frequency of of C --> T transitions at CpG sites was increased by a factor of three. On a cancer-susceptible Apc(Min/+) background, Mbd4-/- mice showed accelerated tumor formation with CpG --> TpG mutations in the Apc gene. Thus MBD4 suppresses CpG mutability and tumorigenesis in vivo.