Corn flour-mimosa tannin-based adhesives without formaldehyde for interior particleboard production

A formaldehyde-free adhesive consisting of a corn flour/NaOH adhesive mixture and a mimosa tannin/hexamine intermediate component was developed and evaluated for application to wood panels such as particleboards. The main ingredients of this adhesive include corn flour, NaOH, mimosa tannin and hexamine. This study investigated the physical properties (rheological and thermal analysis) of corn flour/NaOH and mimosa tannin/hexamine adhesives as well as mechanical properties of particleboards produced with these adhesives. Thermomechanical (TMA) experiments indicate the best performance of the adhesives to be around the relative mass proportions of 50:50 between corn flour/NaOH and mimosa tannin/hexamine. Former NMR measurements on corn starch and mimosa tannin proved that the two components behave as a polymer blend rather than co-reacting. The laboratory results show that particleboards bonded with the adhesive at this optimal ratio show good mechanical properties. Moreover, the formaldehyde emission levels obtained from boards bonded with the optimal adhesive were considerably lower to those obtained from boards made with control urea formaldehyde.     

Riboflavin (Vitamin B2) induces defence responses and resistance to Plasmopara viticola in grapevine

Grapevine (Vitis vinifera) is susceptible to a variety of pathogenic fungi that affect yield and wine quality. Their control is generally achieved by widespread application of fungicides in the vineyards. The economic costs and negative environmental impact associated with these applications has led to a quest for alternative strategies, focusing on manipulation of host defence mechanisms. Here, we evaluated the ability of riboflavin (i.e. Vitamin B₂) to induce resistance against downy mildew in grapevine. Our results showed that 2 mM riboflavin applied 1–3 days before pathogen inoculation provided a disease reduction efficiency of 86 %. A microscopic analysis of the time course of P. viticola colonization in riboflavin-treated leaf discs suggests early inhibition of hyphae spreading in the intercellular space. This resistance does not result from a direct fungitoxic effect of riboflavin. However, this vitamin activates host-defence responses including H₂O₂ generation, upregulation of an array of defence-related genes and synthesis of callose in stomata cells, while stilbene synthesis is not affected. Using a pharmacological approach, we deduced that both jasmonic acid and callose biosynthesis pathways are significantly involved in riboflavin-induced resistance against downy mildew in grapevine.     

Effect of chronic lead intoxication on the distribution and elimination of amoxicillin in goats

A study of amoxicillin pharmacokinetics was conducted in healthy goats and goats with chronic lead intoxication. The intoxicated goats had increased serum concentrations of liver enzymes (alanine aminotransferase and γ-glutamyl transferase), blood urea nitrogen, and reactivated δ-aminolevulinic acid dehydratase compared to the controls. Following intravenous amoxicillin (10 mg/kg bw) in control and lead-intoxicated goats, elimination half-lives were 4.14 and 1.26 h, respectively. The volumes of distribution based on the terminal phase were 1.19 and 0.38 L/kg, respectively, and those at steady-state were 0.54 and 0.18 L/kg, respectively. After intramuscular (IM) amoxicillin (10 mg/kg bw) in lead-intoxicated goats and control animals, the absorption, distribution, and elimination of the drug were more rapid in lead-intoxicated goats than the controls. Peak serum concentrations of 21.89 and 12.19 µg/mL were achieved at 1 h and 2 h, respectively, in lead-intoxicated and control goats. Amoxicillin bioavailability in the lead-intoxicated goats decreased 20% compared to the controls. After amoxicillin, more of the drug was excreted in the urine from lead-intoxicated goats than the controls. Our results suggested that lead intoxication in goats increases the rate of amoxicillin absorption after IM administration and distribution and elimination. Thus, lead intoxication may impair the therapeutic effectiveness of amoxicillin.     

Effects of butorphanol on luteinizing hormone and follicle stimulating hormone levels in ovariectomized rats--comparative study with morphine sulphate.

Studies were conducted into the effects on pituitary gonadotrophic hormones in ovariectomized rats of butorphanol, a synthetic morphine derivative which was claimed to be a potent analgesic with few side-effects, in comparison to effects of the naturally occurring alkaloid morphine. For this purpose, 3 groups of ovariectomized rats were used. Rats of the 1st group were injected butorphanol at 2 dose levels (1 or 2 mg/kg body weight [b.w.]. Those of the 2nd group were injected morphine sulphate (10 or 20 mg/kg b.w.). The 3rd group was injected saline and served as control. Blood samples were collected by orbital sinus punctures, just before treatment and 1 hour post injection. Luteinizing hormone (LH) and follicle-stimulation hormone levels were determined in the sera of rats by radio-immuno-assay. The results revealed that morphine, at the 2 dose levels used, produced more than 90% decrease in serum LH concentration, whereas butorphanol produced more than 70% decrease in serum LH levels. Both morphine and butorphanol, at the 2 doses used, produced more than 76% decrease in serum follicle stimulating hormone concentration. It is concluded that butorphanol, the morphinic derivative, has a depressive effect on the synthesis and/or release of gonadotrophic hormones. This inhibitory effect, however, was nearly as potent as that produced by morphine sulphate.     

Immunologic analysis of blood samples obtained from horses and stored for twenty-four hours

OBJECTIVE: To determine whether immune function can be accurately assessed in blood samples obtained from horses and refrigerated overnight and whether a nonradioactive lymphocyte proliferation assay can be used to evaluate samples obtained from horses. SAMPLE POPULATION: 224 blood samples from 28 clinically normal adult horses. PROCEDURE: Heparinized blood samples were collected. Each sample was divided into 2 equal aliquots. One aliquot was refrigerated overnight to simulate overnight shipping of blood samples, and the other aliquot was evaluated on the day of blood collection. Lymphocytes were isolated and enumerated by use of a modified single-gradient procedure. Cell viability and function were assessed by use of cytologic examination, flow cytometry, and mitogen-induced proliferation assays. Lymphocyte proliferation in response to T- and B-cell mitogens was measured by use of [3H]-thymidine incorporation and a nonradioactive lymphocyte proliferation assay. RESULTS: Lymphocytes refrigerated for up to 24 hours continued to be acceptable for use in immunologic analysis on the basis that they maintained viability and did not have significant alterations in lymphocyte subsets, except for CD8, when compared with freshly isolated lymphocytes. Furthermore, results for mitogen-induced lymphocyte proliferation assays were also comparable between fresh and refrigerated aliquots. CONDUSIONS AND CLINICAL RELEVANCE: The nonradioactive lymphocyte proliferation assay is a reliable alternative to [3H]-thymidine assay for assessing proliferation of equine lymphocytes. Collectively, our results imply that blood samples refrigerated and shipped ovenight to a laboratory can be used to perform cellular-immune assays; results of those assays would enhance a clinician's diagnostic abilities to monitor the efficacy of treatment.     

Production and purification of ovine anti-tetanus antibody

We used the ovine as bioreactor for the production and optimization of anti-tetanus toxin antibody. Four female sheep were immunized with human tetanus vaccine (TT-alum) every two weeks for 16 weeks, after which serum was collected and its titer was estimated by ELISA. The highest titer obtained was 39,000 IU ml-1. To optimize a purification protocol for ovine anti-tetanus toxin, we used four procedures; weak anion (DEAE-Sephadex), weak cation (CM-Sephadex), ammonium sulfate precipitation alone or in combination with caprylic acid. Fifty percent saturation with ammonium sulfate combined with caprylic acid gave us the highest yield of protein with specific activity and the purest Fab product.