Pharmacokinetics of metaflumizone and amitraz in the plasma and hair of dogs following topical application.

Controlled laboratory studies have shown that a metaflumizone plus amitraz combination (ProMeris/ProMeris Duo for Dogs, Fort Dodge Animal Health, Overland Park, KS) applied topically is effective for the treatment and control of fleas and ticks on dogs. Two studies were conducted to determine the distribution of both metaflumizone and amitraz in the plasma and hair of dogs following treatment at the minimum recommended dose of approximately 20mg/kg of each active ingredient. Six purpose-bred, adult Beagle dogs were used in each study. Plasma or hair samples were collected from each dog just prior to dosing and periodically through 56 days after treatment. Samples were analyzed by HPLC methods validated for the simultaneous determination of metaflumizone and amitraz. Amitraz was detectable (>3.2ng/ml) but not quantifiable (<50ng/ml) in only two plasma samples, collected 1 and 2 days post-treatment from different dogs. Metaflumizone concentrations in plasma were generally detectable (>1.0ng/ml) but not quantifiable (<50ng/ml). Measurable levels were found in one dog 7 days post-treatment, increasing to a maximum of four dogs at 42 days after dosing, with a metaflumizone range of 59-138ng/ml. Analysis of hair samples indicated that both metaflumizone and amitraz were widely distributed at basically similar levels in the hair within 1-day after administration, reaching maximum concentrations between 2 and 7 days post-treatment. Low but quantifiable levels of both compounds were still present on hair at the end of the 56-day study. These studies indicate that the ectoparasitic activity is due to exposure of the parasites to metaflumizone and amitraz on the surface of the host (hair and/or skin), not to exposure via the circulatory system of the host.

An integrated ten-pump, eight-channel parallel LC/MS system for automated high-throughput analysis of proteins.

An integrated 10-pump eight-channel LC/MS system has been developed for automated high-throughput analysis of intact proteins in recombinant protein purification processes. The key features of the system include (1) a compact 10-pump HPLC module that uses two pumps to generate a binary gradient and 8 pumps to deliver the mixed gradient to eight independent flow channels; (2) a TOF mass spectrometer with an eight-channel multiplexed ESI interface, which records separate data for all eight channels over each HPLC run cycle; and (3) highly automated data processing software that allows unattended calculation of protein molecular weight (in Da) from original mass spectral data (in m/z). This system was used in the routine screening of fractions from preparative scale chromatography to monitor the purification process with the required mass accuracy and throughput. As an example, the production and purification of an acylated protein with a molecular weight of 9 kDa is described. Using this off-line approach, it is practical to fully characterize protein-containing fractions from column chromatography with an overall analytical throughput of 1 min/protein sample with minimum operator involvement.

Influence of bradykinin in gastrointestinal disorders and visceral pain induced by acute or chronic inflammation in rats.

This work investigated the role of bradykinin in viscerosensitivity before and during inflammation in two models of visceral pain induced by rectal distension (RD) or "abdominal distension" (AD) in rats. RD induced both inhibition of colonic motility and an increase of abdominal spike bursts. Bradykinin receptor antagonist, Hoe 140 did not affect any of the RD-induced responses. After TNB-induced rectal inflammation, colonic inhibition and the number of abdominal contractions were enhanced. Hoe 140 selectively reduced the abdominal response to the highest distension volume, without affecting the colonic response. In AD group, acetic acid inhibited gastric emptying and increased the number of abdominal contractions, whereas the same volume of saline did not affect any of the responses. Before inflammation, Hoe 140 (1-5 mg/kg, intraperitoneally) did not affect per se abdominal and gastric emptying responses; in contrast, at 5 mg/kg, intraperitoneally, it reduced significantly (P < 0.05) both acetic acid-induced responses. We conclude that bradykinin is involved in viscerosensitivity changes related to abdominal and rectal distension in inflammatory conditions.