Effect of fast protein liquid chromatography fractionated salivary gland extracts from different ixodid tick species on interleukin-8 binding to its cell receptors

Interleukin-8 plays a critical role in inflammatory processes. Hence generation of molecules with anti-IL-8 activity is likely to be important for successful feeding and for survival of the ticks. Anti-IL-8 activity was studied in saliva of three ixodid tick species--Dermacentor reticulatus (Fabricius, 1794), Rhipicephalus appendiculatus Neumann, 1901, and Amblyomma variegatum (Fabricius, 1794). The greatest activity was shown in saliva prepared from D. reticulatus. The activity was attributed to tick salivary gland molecules that bind to IL-8, preventing binding of the chemokine to its specific receptor, rather than to occupation of the IL-8 cell receptor by the tick molecules. The distribution of anti-IL-8 activity in fast protein liquid chromatography (FPLC) fractions of salivary gland extracts (SGE) derived from adult female D. reticulatus, R. appendiculatus and A. variegatum was compared directly by both ELISA and receptor-binding inhibition assays. The correspondence in results with fractions of SGE from ELISA is consistent with detection of tick molecules that inhibit IL-8 binding to its receptor. As IL-8 is an important chemoattractant and activator of neutrophils, the presence of an anti-IL-8 activity in tick saliva indicates that neutrophils play an important role in the host response to parasitism by ticks.     

Pharmacokinetics of florfenicol in the plasma of Japanese quail

Abstract

AIM: To determine the pharmacokinetics and bioavailability of florfenicol in the plasma of healthy Japanese quail (Coturnix japonica).

METHODS: Sixty-five quail were given an I/V and I/M dose of florfenicol at 30 mg/kg bodyweight (BW). A two-period sequential design was used, with a wash-out period of 2 weeks between the different routes of administration. Concentrations of florfenicol in plasma were determined using high-performance liquid chromatography (HPLC).

RESULTS: A naíve pooled data analysis approach for the plasma concentration-time profile of florfenicol was found to fit a non-compartmental open model. After I/V administration, the mean residence time (MRT), mean volume of distribution at steady state (V_ss), and total body clearance of florfenicol were 12.0 (SD 0.37) h, 8.7 (SD 0.22) L/kg, and 1.3 (SD 0.08) L/h/kg, respectively. After I/M injection, the MRT, mean absorption time (MAT), and bioavailability were 12.3 (SD 0.37) h, 0.2 (SD 0.02) h, and 79.1 (SD 1.79)%, respectively.

CONCLUSIONS: The time for the concentration of florfenicol to fall below the probable effective concentration of 1 µg/ml of approximately 10 h is sufficient for the minimum inhibitory concentration needed for many bacterial isolates. Further pharm acodynamic studies in quail are needed to evaluate a suitable dosage regimen.     

Therapeutic and prophylactic efficacy of imidocarb dipropionate on experimental Babesia ovis infection of lambs

The objective of this study was to evaluate the therapeutic and prophylactic efficacy of imidocarb dipropionate (IMDP) against babesiosis and to determine specific antibodies against Babesia ovis in experimentally infected lambs. Thirty-six 6-month-old splenectomized lambs were used. The lambs were randomly divided into six groups with six animals each, and were intravenously inoculated with 50 mL B. ovis-infected erythrocytes as follows: group I (therapy group) was treated with IMDP (1.2 mg/kg body weight) starting on the day of onset of clinical signs of babesiosis after the inoculation; group II (untreated control animals) was not treated with any therapeutic treatment after the inoculation; groups III, IV, V and VI (prophylaxis groups) were administered IMDP (2.4 mg/kg body weight) 1, 2, 3 and 4 weeks before the inoculation, respectively. The animals were housed in a tick-proof room with water and food ad libitum up to the 30th day post-inoculation (PI). The lambs were monitored from the first day PI by recording the manifestation of clinical disease, rectal temperature, and the degree of parasitaemia. All the lambs became infected with B. ovis, except five animals from group III, which were treated 1 week prior to experimental infection. Other animals showed signs of acute clinical babesiosis. The animals treated with IMDP (group I) were able to clear the parasite from the blood circulation after 48 h post-treatment. The recrudescence of B. ovis was observed in two lambs 7 days after treatment, and they were treated with the second similar dose of the drug. Six lambs (1, 1, 2 and 2 lambs in group III, IV, V and VI, respectively) from the prophylaxis groups died within 7-17 days after showing high parasitaemia and clinical symptoms of the disease. Regardless of the clinical symptoms, 83.30% and 66.66% of the lambs which were administered IMDP 1-2 and 3-4 weeks before, were determined to be protected against the virulent field strain of B. ovis.     

Transformation of dairy activity in Mexico in the context of current globalization and regionalization

To explain globalization of the Mexicandairy production more precisely, globalization indairy systems worldwide and within Mexico ispresented, using an intensive dairy operation in theregion of La Laguna (North Mexico), and a traditionaldairy operation in Los Altos de Jalisco (West Mexico)as examples. The focus is on the economic aspects ofregionalization, and how it relates to theglobalization process. In this context, the process ofregionalization of the North American dairy systemsand their relationships with the local systems in LaLaguna and Los Altos de Jalisco are presented. Themain thesis in this paper is whether globalization hasacted as a factor to help homogenize the dairy systemsin terms of economic, political, and culturalprocesses affected by world tendencies as well aslocal trends.     

Surface quality and hardness of eastern redcedar as function of steaming

The objective of this study was to evaluate influence of steam treatment on surface quality and hardness of eastern redcedar (Juniperus virginiana L.). Defect-free samples with dimensions of 40 mm by 50 mm in by 20 mm were used for the tests. Specimens were exposed to steam having a temperature of 130 °C for 1-h and 3-h periods of time. Surface roughness of the samples at initial and exposed conditions was determined using stylus type equipment across the grain orientation on tangential surface of each sample. Janka hardness of the control and treated samples was also determined on Comten testing system. Based on the findings in this work, no significance was found between surface roughness values of the specimens steamed for 1 and 3 h. However, both types of steamed specimens had higher average roughness values ranging from 52 and 60 % than those of control samples. It appears that 3-h steaming adversely influenced hardness of the samples reducing its 9 % as compared to those of control samples. Densification effect of steaming on the samples was also evaluated using scanning electron microscope (SEM) and it was determined that steaming had some crushing effect on the cell wall.     

Utilization of pine (Pinus pinea L.) cone in manufacture of wood based composite

Physical and mechanical properties of medium density fiberboards (MDF) made from various mixtures of wood fibers and stone pine (Pinus pinea L.) cones were evaluated using European standards. MDF panels were manufactured using standardized procedures that simulated industrial production at the laboratory. Six panel types were made from mixtures of wood fiber/cone flour, 100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 percents, respectively. Addition of the cone flour into the MDF significantly reduced formaldehyde emission from the panel. In addition, the addition of 10% cone flour also improved water resistance of the MDF panels made using urea–formaldehyde (UF) resin. However, further addition of the cone flour into the panel negatively influenced their water resistance. Flexural properties and internal bond strength decreased with the increase of cone flour content in the panel. The UF resin is the main source of formaldehyde emission from the UF-bonded wood-based panels. Depending on addition of the cone flour in the panels, the formaldehyde emission values ranged from 2.6% to 55.3% lower than the panels made from 100% wood fiber. Based on the findings obtained from this study, pine cone can be used as a renewable biological formaldehyde catcher as an alternative to the traditional formaldehyde catchers for E1 Class MDF manufacture.