Rapid radiosynthesis of [11C] and [14C]azelaic,suberic, and sebacic acids for in vivo mechanistic studies of systemic acquired resistance in plants

A recent report that the aliphatic dicarboxylic acid, azelaic acid (1,9‐nonanedioic acid) but not related acids, suberic acid (1,8‐octanedioic acid) or sebacic (1,10‐decanedioic acid) acid induces systemic acquired resistance to invading pathogens in plants stimulated the development of a rapid method for labeling these dicarboxylic acids with ¹¹C and ¹⁴C for in vivo mechanistic studies in whole plants. ¹¹C‐labeling was performed by reaction of ammonium [¹¹C]cyanide with the corresponding bromonitrile precursor followed by hydrolysis with aqueous sodium hydroxide solution. Total synthesis time was 60 min. Median decay‐corrected radiochemical yield for [¹¹C]azelaic acid was 40% relative to trapped [¹¹C]cyanide, and specific activity was 15 GBq/µmol. Yields for [¹¹C]suberic and sebacic acids were similar. The ¹⁴C‐labeled version of azelaic acid was prepared from potassium [¹⁴C]cyanide in 45% overall radiochemical yield. Radiolabeling procedures were verified using ¹³C‐labeling coupled with ¹³C‐NMR and liquid chromatography–mass spectrometry analysis. The ¹¹C and ¹⁴C‐labeled azelaic acid and related dicarboxylic acids are expected to be of value in understanding the mode‐of‐action, transport, and fate of this putative signaling molecule in plants. Copyright © 2011 John Wiley & Sons, Ltd.     

Effects of Cling Film Draping Material on Body Temperature of Mice During Surgery

General anesthesia induces many systemic effects, including thermoregulatory impairment and subsequent perioperative hypothermia. Due to the animals’ small size, monitoring and maintaining body temperatures in laboratory rodents during anesthesia is important for successful surgical outcomes and prompt anesthetic recovery. Draping materials have the potential to aid in thermal support during surgical anesthesia. In this study, rectal and surface (infrared) temperatures were measured in C57BL/6 mice under isoflurane anesthesia every 5 min for the duration of a 35-min sham surgery. In addition to placement on a circulating water bath, mice (n = 6/group) were draped with commercial cling film (CF; Press''n Seal, Glad, Oakland, CA), a conventional paper drape (PD), or no drape (ND) during surgery. Results demonstrated that CF-draped animals had significantly higher rectal temperatures than nondraped animals. Furthermore, surface temperatures of CF-draped mice were considerably higher than those of both paper-draped and undraped animals. The data indicate that cling film is an effective material to help minimize hypothermia in mice and potentially in other laboratory rodents requiring general anesthesia.

Surgery and anesthesia introduce many challenges, especially in veterinary medicine, due to the diversity of species. One major challenge during general anesthesia involves changes in an animal''s thermoregulatory ability.^1,14 Body temperatures in mice and rats fall significantly during anesthesia if no thermal support is provided.^29,30 Hypothermia occurs due to drug-induced alterations to the thermoregulatory center, inadequate circulation, and a loss of body heat to the environment from evaporation, radiation, conduction, and convection.⁷ Mice are particularly susceptible to hypothermia, due to their large surface area per gram of body weight, which permits significant physiologic changes in response to fluctuations in the ambient temperature.³¹ Covering the animal''s body with towels, drapes, or blankets to reduce the area exposed to the environment can minimize heat loss.^6,7,13 Placing the animal on an insulated surface can limit conductive heat loss. In larger animals, warmed fluids can be given perioperatively, heated anesthetic gasses can be administered, and heated blankets and heat packs can be applied to body surfaces to provide exogenous heat.^1,7 Safer and more practical methods for rodents are circulating water heating blankets, thermal gel packs, and warming lamps, which are commonly used for thermal support during anesthesia.^5,14 Addressing all of these factors can contribute to maintaining normothermia during anesthesia.Risk of mortality is elevated during anesthesia and in the postoperative period, including in rodents.^1,13 Hypothermia induced by anesthesia can negatively affect rodents by altering vital parameters such as heart rate and blood pressure and delaying anesthetic recovery.^3,5,12,19 These risks require careful selection of an appropriate anesthetic protocol and careful monitoring of the patient throughout anesthesia until full recovery occurs. Strict anesthetic monitoring and the use of supplemental heat devices have been shown to reduce the likelihood of complications, improve overall postoperative recovery, and reduce mortality associated with surgical procedures.^1,7,15,16 However, due to these species’ small size, monitoring equipment must be specialized and is often costly. Cost-effective and practical alternative equipment and materials would facilitate monitoring and care of rodents.Various draping options are available for rodent surgery, and their use is vital for both sterile technique and heat retention. Traditionally, paper draping material has been a popular option, because it is relatively inexpensive and can be autoclaved together with surgical instruments.^15,16 Some institutions have adopted varying methods and types of draping, including no drape and paper draping. Commercial cling film (CF) has been used as draping due to its low cost, ease of use, and sterility straight out of the box.⁹ Our study team sought to evaluate the effects of draping material on intraoperative thermoregulation in mice by measuring rectal temperature (modified rectal probe) and surface temperature (infrared device) during a 35-min laparotomy procedure, with both temperature devices chosen for affordability and availability. We hypothesized that mice draped with CF would maintain a higher intraoperative body temperature under general anesthesia than would mice with traditional paper drapes or no drape.     

Absence of intestinal synthesis of apolipoprotein B-48 in two cases of abetalipoproteinemia

Previous studies have reported that the absence of chylomicron, very-low-density lipoprotein, and low-density lipoprotein in abetalipoproteinemia is a consequence of apoprotein B (apo B) deficiency. Although the absence of apo B from the intestine has been shown by immunofluorescence, the antiserum used was raised against low-density lipoprotein apo B. Therefore, the precise nature of the underlying defect remains unknown, given that the postulated gene mutation could prevent the synthesis of the molecular form of apo B specific for chylomicrons, apo B-48, or produce an unstable aberrant form of apo B particle. This report concerns 2 girls aged 5.5 and 4.75 with well-documented clinical and biological manifestations of the disease in whom there was no immunologically detectable plasma apo B-48 and apo B-100. Their cultured jejunal explants incubated with [14C]palmitate showed slight decrease in the esterification of triglycerides, phospholipids, and cholesteryl esters. However, only traces of triglycerides and small amounts of cholesteryl esters were found in the culture medium in contrast to phospholipids, which were readily exported. Protein synthesis as assessed by [3H]leucine incorporation by explants was normal and only modestly diminished in the fat chylomicronlike fraction floated from the sonicated explants. However, there was no radioactivity at the electrophoretic position of apo B-100 and apo B-48. Immunologic confirmation of the absence of these two apoproteins was obtained by Western blots. These data confirm the hypothesis that in certain cases of abetalipoproteinemia the intestinal defect results from the lack of synthesis of apo B-48.     

The alternate iron transport pathway: mobilferrin and integrin in reticulocytes

Iron transport in reticulocytes is known to occur via the well-described transferrin-receptor–endosome pathway. An alternative pathway for iron transport independent of transferrin has been postulated in reticulocytes and other cells. Transport of iron into reticulocytes from ferric citrate solutions was shown to be saturable and independent of transferrin. During transport of iron from ferric citrate, both cell surface integrins, and a soluble protein, mobilferrin, were labelled. This demonstrated that the reticulocyte transferrin independent pathway for iron transport involved integrins and mobilferrin similar to intestinal absorptive cells. This pathway would be expected to transport iron into cells under conditions of iron overload and was capable of providing iron for haemoglobin synthesis. Mobilferrin was also radiolabelled when radioiron labelled transferrin was incubated with reticulocytes and this occurred with a different time course than was observed following reticulocyte exposure to radiolabelled ferric citrate. This suggested that mobilferrin may serve as an intermediary in both pathways.