Using 20-gauge percutaneous peripheral catheters to reliably collect serial 4-mL blood samples from conscious dogs

Objective To determine the reliability of collecting serial 4-mL blood samples over 13 h using a 20-gauge, cephalic catheter in conscious dogs. Design Prospective, observational study. Animals Twelve (6 males, 6 females) healthy, neutered, lean dogs. Procedure Percutaneous placement of a 20-gauge, 1.1 × 30 mm intravenous over-the-needle catheter into the cephalic vein was performed in each dog on three occasions. Catheter patency was maintained by intermittent flushing with 0.9% saline and 1 IU/mL heparinised saline solutions. Blood samples (4 mL) were obtained at 10 time-points over 13 h, with close monitoring of the dogs and the indwelling catheters. Blood volume, resistance on aspirating blood sample (minimal or marked resistance) and the methods used to improve blood flow were recorded. Results A high proportion (93%) of blood sample collections achieved the required 4-mL volume, and the remaining samples were greater than 1.5 mL. Of the 358 collections via the cephalic catheter, 311 (87%) were obtained with ‘minimal resistance’. The remaining collections had ‘marked resistance’ (n=47) and were associated with a loose catheter in 11% (5/47) and of unknown cause in 89% (42/47). After ‘marked resistance’ had been encountered and the catheter was flushed with saline and heparin solutions, subsequent sampling with ‘minimal resistance’ was frequently possible from the same catheter. Conclusion Use of a percutaneous, 20-gauge intravenous cephalic catheter allowed reliable serial collection of 4-mL blood samples over 13 h in conscious dogs.     

Diplonine, a neurotoxin isolated from cultures of the fungus Stenocarpella maydis (Berk.) Sacc. that induces diplodiosis

Diplodiosis is a neuromycotoxicosis of cattle and sheep caused by ingestion of maize infected with the ear-rot fungus Stenocarpella (= Diplodia ) maydis . Apart from ataxia, paresis, and paralysis, the toxin is responsible for stillbirths and neonatal losses characterized by the presence of spongiform degeneration in the white matter of the brain in the offspring of dams exposed to infected maize cobs. In the present study a toxin, named diplonine, which induced neurological signs in guinea pigs resembling some of those occurring in cattle and sheep, was isolated from S. maydis cultures. Purification of diplonine was achieved by methanol extraction followed by chromatographic separation on silica gel and RP-18 stationary phases. The structure and relative configuration of diplonine were defined by analysis of NMR and MS data as (S)-2-amino-2-[(1R,2S)-1-hydroxy-2-methylcyclopropyl]acetic acid or the (S)-2-amino-2-[(1S,2R)-diastereomer.     

Pathology of a nervous disorder (pushing disease or "stootsiekte") in cattle caused by the plant Matricaria nigellifolia DC. (Asteraceae)

Brains from 10 bovine field cases of pushing disease, a nervous disorder caused by the plant, Matricaria nigellifolia, were examined by light microscopy. Moderate to marked encephalitis, characterized by predominantly perivascular microgliosis, perivascular lymphocytic infiltrates and reactive changes in astrocytes, was present in all the brains. The lesion was concentrated in the white matter throughout the forebrain and midbrain. Dried, milled M. nigellifolia was dosed to 6 steers. Clinical signs of pushing disease, which included docility, clumsiness and pushing against objects, appeared abruptly in 5 of the steers after a latent period that varied from 16-44 days. The lowest total dose of plant that proved toxic was 10 g/kg. The length of the latent period appeared to be related inversely to the total dose. Encephalitis, which was similar in nature and distribution to those in the field cases, was demonstrated in the 5 affected steers. The lesion was minimal in the brain of the steer that did not develop pushing disease. The cerebral lesion is sufficiently consistent and distinctive to be useful in establishing a diagnosis of pushing disease. The perivascular distribution of microgliosis suggests that the site of the toxic insult is the cerebral vasculature. Botanical information is presented.     

酒制熟地黄炮制过程中梓醇的变化趋势及变化机理

为研究酒制熟地黄炮制工艺过程中梓醇的变化趋势和变化机理，利用HPLC检测酒制熟地黄炮制过程中不同时间点梓醇的含量，并利用FT-IR结合变温附件获取梓醇在不同温度点的红外光谱信息。结果表明，酒制熟地黄炮制过程中，梓醇含量整体呈下降趋势，但不同时间段梓醇含量下降率不同。梓醇含量下降的原因是其热稳定性较低，在温度90～100℃之间，其结构就发生变化。所以，生地黄产地加工焙干时，温度不能太高，以免梓醇含量下降；熟地黄炮制过程中，时间不能太短，以免“火候”不到。