Effects of growth hormone, insulin-like growth factor-I, and cortisol on periparturient antibody response profiles of dairy cattle

The objectives of this study were to determine hormone and antibody response profiles from the prepartum period to peak lactation, and evaluate potential immunomodulatory effects of the classic endocrine hormones, growth hormone (GH), insulin-like growth factor-I (IGF-I) and cortisol. Specifically, 33 Holstein cows were immunized with ovalbumin (OVA) and Escherichia coli J5 at weeks -8 and -3 prior to parturition. At parturition (week 0), cows received an additional immunization of OVA. Blood was collected at weeks -8, -3, 0, 3 and 6 relative to parturition and various samples were used to determine plasma hormone concentration, serum immunoglobulin (Ig), and specific antibody response to OVA and E. coli. Colostrum and milk samples were also collected post-parturition to monitor local immunoglobulin and antibody responses. Results indicated that not all periparturient cows exhibited depressed immune response, and that antibody response to OVA could be used to partition cows into 3 groups recognizing animals with sustained measurable antibody response before and after parturition (Group 1), animals which responded poorly to immunization at parturition (Group 2), and animals which did not respond to immunizations at week -3 or parturition (Group 3). Cows with the highest antibody response to OVA (Group 1) also tended (P < or = 0.10) to have the highest response to E. coli J5 at parturition and had the lowest incidence of disease, particularly mastitis. Antibody response to OVA measured in milk tended to be higher in Group 1 cows, particularly at week 0 (P < or = 0.06) compared to cows of Group 3. IGF-I was higher (P < or = 0.05) in cows of Group 1 than Group 3 at peak lactation (week 6).     

The ATP-binding site of protein kinase CK2 holds a positive electrostatic area and conserved water molecules

CK2 is a highly pleiotropic Ser/Thr protein kinase that is able to promote cell survival and enhance the tumour phenotype under specific circumstances. We have determined the crystal structure of three new complexes with tetrabromobenzimidazole derivatives that display K(i) values between 0.15 and 0.30 microM. A comparative analysis of these data with those of four other inhibitors of the same family revealed the presence of some highly conserved water molecules in the ATP-binding site. These waters reside near Lys68, in an area with a positive electrostatic potential that is able to attract and orient negatively charged ligands. The presence of this positive region and two unique bulky residues that are typical of CK2, Ile66 and Ile174, play a critical role in determining the ligand orientation and binding selectivity.     

Urolithin as a converging scaffold linking ellagic acid and coumarin analogues: design of potent protein kinase CK2 inhibitors

Casein kinase 2 (CK2) is a ubiquitous, essential, and highly pleiotropic protein kinase; its abnormally high constitutive activity is suspected to underlie its pathogenic potential in neoplasia and other relevant diseases. Previously, using different in silico screening approaches, two potent and selective CK2 inhibitors were identified by our group: ellagic acid, a naturally occurring tannic acid derivative (K(i)=20 nM) and 3,8-dibromo-7-hydroxy-4-methylchromen-2-one (DBC, K(i)=60 nM). Comparing the crystallographic binding modes of both ellagic acid and DBC, an X-ray structure-driven merging approach was taken to design novel CK2 inhibitors with improved target affinity. A urolithin moiety is proposed as a possible bridging scaffold between the two known CK2 inhibitors, ellagic acid and DBC. Optimization of urolithin A as the bridging moiety led to the identification of 4-bromo-3,8-dihydroxy-benzo[c]chromen-6-one as a novel, potent and selective CK2 inhibitor, which shows a K(i) value of 7 nM against the protein kinase, representing a significant improvement in affinity for the target compared with the two parent fragments.     

Crystal structure of TNF-alpha mutant R31D with greater affinity for receptor R1 compared with R2

Crystal structures have been determined of recombinant human tumor necrosis factor-alpha (TNF-alpha) and its R31D mutant that preferentially binds to TNF receptor R1 with more than seven times the relative affinity of binding to receptor R2. Crystals of the wild-type TNF were of space group P4(1)2(1)2 and had unit cell dimensions of a = b = 94.7 and c = 117.4 A. Refinement of the structure gave an R-factor of 22.3% at 2.5 A resolution. The crystals of TNF R31D mutant diffracted to 2.3 A resolution, and were of identical space group to the wild type with unit cell dimensions of a = b = 95.4 and c = 116.2 A, and the structure was refined to an R-factor of 21.8%. The trimer structures of the wild-type and mutant TNF were similar with a root mean square (r.m.s.) deviation of 0.56 A for Calpha atoms; however, the subunits within each trimer were more variable with an average r.m.s. deviation of 1.00 A on Calpha atoms for pairwise comparison of subunits. Model complexes of TNF with receptors R1 and R2 have been used to predict TNF-receptor interactions. Arg31 in all three subunits of wild-type TNF is predicted to form an ionic interaction with the equivalent glutamic acid in both receptors R1 and R2. Asp31 of the TNF R31D mutant is predicted to interact differently with the two receptors. The side chain of Asp31 in two subunits of the TNF mutant is predicted to form hydrogen bond interactions with Ser59 or Cys70 of R1, while it has no predicted interactions with R2. The loss of three strong ionic interactions of Arg31 and the electrostatic repulsion of Asp31 with Glu in the receptors is consistent with the reduced binding of the R31D mutant to both receptors relative to wild-type TNF. The replacement of these ionic interactions by two weaker hydrogen bond interactions between Asp31 of the R31D mutant and R1, compared with no interactions with R2, is in agreement with the observed preferential binding of the R31D mutant to R1 over R2. Analysis of the structure and function of receptor-discriminating mutants of TNF will help understand the biological role of TNF and facilitate its use as an antitumor agent.      

The Influence of the Amount of Fluoride Catalyst on the Morphological Properties of the Anilinepropylsilica Xerogel Prepared in Basic Medium

Anilinepropylsilica hybrid powder was synthesized by a sol-gel route in basic medium using HF as catalyst. The effect of the amount of HF catalyst on the morphologies and on organic content was studied. The xerogels were characterized using FTIR, SEM and N₂ adsorption-desorption isotherms. The increase in the HF quantity results in an slight increase in organic content and changes in the particle size, surface area and pore structure.     

Correlation of cerebral blood flow with outcome in head injured patients

In order to determine the relationship of cerebral blood flow (CBF) to the clinical outcome of head injury, serial determinations of CBF were performed by the intravenous Xenon technique in 24 patients. The patients were of mixed injury severity and were classified into four groups depending on the neurological exam at the time of each CBF study. All eight patients who were lethargic on admission demonstrated increases in their minimally depressed CBF as they improved to normal status. Eleven patients in deep stupor or coma ultimately recovered. Ten of these patients initially had moderate to profound decreases in CBF which improved as recovery occurred. The single exception was an adolescent whose initial CBF was high but became normal at recovery. Five comatose patients died. In four of these, already depressed CBF fell even lower, while one adolescent with initially increased CBF developed very low CBF preterminally. The data presented in this report demonstrated a good correlation between CBF and clinical outcome. In every one of the adult survivors, depressed CBF increased as the patient recovered to normal status. All adults who died showed a deterioration of CBF as the neurological status worsened. The only exceptions were two adolescents who initially showed high CBF values. In the adolescent who died, CBF dropped to low levels while in the survivor a normal CBF was achieved. Thus in adults a traumatic brain injury was associated with depressed CBF which increased with recovery or decreased further with deterioration while the reaction to injury was quite different in the younger brain.     

Intraventricular chemotherapy in neonatal meningitis

All of 16 infants with neonatal meningitis treated during a 30-month period were found to have accompanying ventriculitis at the time of the initial ventricular puncture. Fifteen of these infants were caused by gramm-negative organisms. All infants received antibiotics systemically and intraventricularly via an implanted ventriculostomy reservoir or by direct ventricular injection. Antibiotic concentrations within the ventricular fluid were monitored during chemotherapy; the complications encountered during treatment are discussed. Fifteen infants survived the infection; of these, seven infants were normal at follow-up examinations. In our experience intraventricular chemotherapy as an adjunct to systemic administration of antibiotics has greatly reduced the mortality rate in neonatal meningitis.