Cloning and expression of an atrazine inducible cytochrome P450, CYP4G33, from Chironomus tentans (Diptera: Chironomidae)

Previous studies performed in our laboratory have measured the effect of atrazine exposure on cytochrome P450-dependent monooxygenase activity and have found increased activity in midge larvae (Chironomus tentans) as a result of atrazine exposure (1-10 ppm). Here we report the cloning and expression of a specific C. tentans CYP4 gene that is responsive to atrazine induction with an open reading frame of 1678 bp which encodes a putative protein of 559 amino acid residues. Alignments of deduced amino acid sequences with other insect P450 genes and phylogenetic analysis indicated a high degree of similarity to other insect CYP4 genes. Northern blotting analysis employing a fragment of 1200 bp from the CYP4 gene as a probe indicated that the CYP4 gene was expressed in all developmental stages, but was expressed at highest levels in late instar larvae. Additionally, over-expression of CYP4 in C. tentans exposed to atrazine (10 mg/l) confirms the ability of atrazine to induce specific P450 genes and provides insight into potential consequences of atrazine exposure in aquatic organisms.     

Phosphorus and phosphate metabolism in veterinary patients

Objective: To review phosphorus and phosphate metabolism and the importance of phosphate abnormalities in veterinary patients. Data sources: A review of recent human and veterinary medical literature. Human data synthesis: There is a significant amount of original research on human patients with phosphate abnormalities. Hypophosphatemia has been studied in patients with diabetic ketoacidosis (DKA), head trauma, refeeding syndrome, hypothermia and in ventilator patients that fail to wean. Hyperphosphatemia has been studied in patients with renal failure and malignancy. Phosphate levels have also been evaluated for prognostic value in sepsis and acute liver failure. Veterinary data synthesis: Although animal models were used in early experimental research, fewer studies have been published on the effects of phosphate abnormalities in veterinary patients. Hypophosphatemia has been studied in animals with DKA, with refeeding syndrome and with hyperparathyroidism. Hyperphosphatemia has been studied in animals with renal failure and with secondary hypoparathyroidism. Conclusion: Phosphorus and phosphate are important in many biological functions. This paper is a review of their role in normal metabolism and the clinical importance of phosphate imbalances for our emergency and critical care patients.     

Herbicide residues in waste waters from ricefields

The herbicides bentazone, 2,4-D, MCPA, propanil, molinate, and tiocarbazil, and the insecticide phenthoate, were applied to ricefields in Sardinia at rates equivalent to maximum aqueous concentrations of 0.4-2.8 mg kg^?1, assuming the water to be 20 cm deep. Their concentrations in water were measured by high-performance liquid chromatography. Residues in 162 water samples, collected from 16 ricefields 1, 4, 7, 10, 12, 18, 21 and 120 days after the last spraying, were all below the limit of determination (0.03 mg kg^?1). Residues in 40 water samples taken from five drainage canals were also less than 0.03 mg kg^?1.     

Structure-activity relationships in fungitoxicants related to triforine and chloraniformethan. Part IV: Evaluation of the predictive power of the Hansch analysis by the preparation and testing of further chloraniformethan analogues

Seven chloraniformethan analogues, which were predicted, on the basis of the quantitative Hansch analysis performed previously, to be as active as the parent compound against barley powdery mildew (Erysiphe graminis), were prepared. Their activity as leaf sprays against E. graminis was much lower than that calculated using the regression equations, indicating that the Hansch analysis is not a suitable method for predicting fungitoxicity in this chloraniformethan series of compounds.     

Fungicidal activity and chemical constitution. XX. The activity of substituted 1,4-naphthohydroquinone esters and substituted 1,4-naphthoquinones against powdery mildews

Eleven 2-n-alkyl-, ten 2-n-alkyl-3-hydroxy- and ten 2-n-alkyl-2,3-epoxy-3-hydro-1,4-naphthoquinones, together with eighteen 1,4-naphthohydroquinone esters were tested as protectant fungicides against the apple and cucumber powdery mildews (caused by Podosphaera leucotricha and Sphaerotheca fuliginea respectively). In.general the former pathogen was more susceptible to compounds from all four series, the lowest 10⁵ED⁵⁰(M) being 0.7 for 2-n-octyl-2,3-epoxy-3-hydro-1,4 naphthoquinone.     

Effect of Pre- and Post-Partum Feed Supplementation on the Productive and Reproductive Performance of Grazing Primiparous Brahman Cows

This experiment studied the combined effect of pre- and post-calving feed supplementation on the productive and reproductive performance of primiparous Brahman cows. The animals were 4 years old (420 kg live weight) and pregnant, and grazed rotationally on Stargrass (Cynodon nlemfuensis) pastures. Supplementation was given before and after (T1, n = 15), only before (T2, n = 15) or only after (T3, n = 16) calving, and there was an unsupplemented control (T4, n = 16). The supplement (1.5 kg/animal per day, 13.4 MJ digestible energy/kg dry matter and 20% crude protein) was given for 45 days before and/or after calving. Changes in body weight and body condition score and the productive behaviour of the calves were similar (p>0.05) among treatments. The concentration of urea in the plasma was low in the control group (T4) before and after calving. The animals in all the groups had a poor reproductive performance. The percentage of cows in oestrus was higher (p<0.05) in T1 (73.3%) than in T3 (37.5%). The interval from calving to conception (148.7±53.7 days) and the pregnancy rate (48.5%) were similar (p>0.05) among the treatments. The level of supplementation offered before and/or after calving did not improve the pregnancy rate.     

Immunization of rats against Fasciola hepatica using crude antigens conjugated with Freund's adjuvant or oligodeoxynucleotides

Chronic Fasciola hepatica infection is correlated with the development of a T helper (Th2)-predominant immune response. To determine whether immunostimulatory CpG-containing oligodeoxynucleotides (CpG-ODN) or Freund's complete adjuvant (FCA), known to promote a Th1 (T helper 1) immune responses, could provide protection from F. hepatica infection, total homogenate (TH) of F. hepatica mixed with CpG-ODN or FCA were injected subcutaneously (s.c.) into Wistar rats. A F. hepatica-specific Th1-predominant immune response was induced with CpG-ODN or FCA in lymph nodes of immunized animals. Lymph node cells from TH-CpG-ODN or TH-FCA immunized rats showed increased antigen-specific proliferation with high levels of INFgamma, compared to lymphocytes from rats injected with TH alone. In contrast, these two groups of immunized animals did not modify IL-4 release by draining lymph node cells, when they were subsequently stimulated with TH in vitro. However, a significant reduction in the burden of flukes (76.7%) was only observed in rats immunized with TH-FCA. Conversely, immunization of rats with TH-CpG-ODN did not promote protection against the parasite. Therefore, even though CpG-ODNs and FCA induced Th1 type responses, only FCA provided a significant protection to rats infected with F. hepatica.