Effects of hypertonic dextrose injections in the rabbit carpal tunnel

Objective

This study investigated the effects of different doses of hypertonic dextrose injection on the carpal tunnel subsynovial connective tissue (SSCT) and median nerve in a rabbit model.

Methods

Thirty‐eight New Zealand white rabbits weighing 4.0–4.5 kg were used. One forepaw carpal tunnel was randomly injected with one of five different treatments: saline‐single injection; saline‐two injections 1 week apart; 10% dextrose‐single injection; 20% dextrose‐single injection; or 10% dextrose‐two injections 1 week apart. Animals were sacrificed at 12 weeks after the initial injection and were evaluated by electrophysiology (EP), SSCT mechanical testing and histology.

Results

There were significant increases in the energy absorption of the SSCT in the 10% dextrose‐double injection group compared to the saline injection groups. SSCT stiffness was also significantly increased in the 10% dextrose‐double injection group compared to the other groups. There was a significant increase in the thickness of the SSCT in the 10% dextrose‐double injection group compared to the saline‐single injection group and a significant decrease in the nerve short‐long diameter ratio in the 10% dextrose‐double injection group compared to the saline‐single injection group. There were no changes in EP among the groups.

Conclusions

SSCT fibrosis is present for up to 12 weeks after dextrose injection; multiple injections have bigger effects, including what appears to be a secondary change in nerve flattening. This model may be useful to study the effects of external fibrosis on nerve morphology and physiology, such as occurs clinically in carpal tunnel syndrome. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1022–1027, 2011     

Candida albicans is an immunogen for anti-Saccharomyces cerevisiae antibody markers of Crohn's disease

BACKGROUND AND AIMS: Antibodies directed against oligomannose sequences alpha-1,3 Man (alpha-1,2 Man alpha-1,2 Man)(n) (n = 1 or 2), termed anti-Saccharomyces cerevisiae antibodies (ASCAs) are markers of Crohn's disease (CD). S. cerevisiae mannan, which expresses these haptens, is used to detect ASCA, but the exact immunogen for ASCA is unknown. Structural and genetic studies have shown that Candida albicans produces mannosyltransferase enzymes that can synthesize S cerevisiae oligomannose sequences depending on growth conditions. This study investigated whether C. albicans could act as an immunogen for ASCA. METHODS: Sequential sera were collected from patients with CD, systemic candidiasis, and rabbits infected with C. albicans. Antibodies were purified by using chemically synthesized (Sigma) ASCA major epitopes. These affinity-purified antibodies and lectins were then used to analyze the expression of ASCA epitopes on molecular extracts and cell walls of C. albicans and S cerevisiae grown in various conditions. RESULTS: In humans and rabbits, generation of ASCA was shown to be associated with the generation of anti-C. albicans antibodies resulting specifically from infection. By using affinity-purified antibodies, C. albicans was shown to express ASCA epitopes on mannoproteins similar to those of S. cerevisiae. By changing the growth conditions, C. albicans mannan was also able to mimic S. cerevisiae mannan in its ability to detect ASCA associated with CD. This overexpression of ASCA epitopes was achieved when C. albicans grew in human tissues. CONCLUSIONS: C. albicans is one of several immunogens for ASCA and may be at the origin of an aberrant immune response in CD.     

Evaluation of a porcine model to study in vivo platelet activation

INTRODUCTION: In order to investigate if decompression sickness involves platelet activation an animal model was evaluated. MATERIALS AND METHODS: Twenty-four thiopentone-midazolam-fentanyl-anaesthetized pigs in four groups received 5-min infusions of adenosine diphosphate (25 mg/kg) or platelet activating factor (0.4 microg/kg). Groups 1 and 2 (adenosine diphosphate, n=6 and platelet activating factor, n=6) were studied for 30 min and then sacrificed. Groups 3 and 4 (adenosine diphosphate, n=6 and platelet activating factor, n=6) were sacrificed immediately afterwards to study short-term changes. Haemodynamics, platelet counts and post mortem lung platelet aggregates were registered. Groups 1 and 2 also had indium platelet labelling, lung scintigraphy and platelet accumulation index calculations performed. RESULTS: Adenosine diphosphate induced immediate and more profound transient shocks. Platelet and leukocyte count decreases and occurrences of post mortem lung platelet aggregates were significantly more profound in the 5-min adenosine diphosphate group (Group 3) than in the platelet activating factor group (Group 4). With platelet labelling there were positive platelet accumulation index trends in the 30-min adenosine diphosphate group (Group 1). Adenosine diphosphate also produced platelet aggregation in platelet-rich porcine plasma. Only adenosine diphosphate (an intermediate platelet agonist) showed signs of platelet activation when considering all platelet parameters. The model should be further evaluated with different bolus doses of adenosine diphosphate, but may be used to evaluate if gas bubbles introduced into the circulation (as with decompression sickness), or possibly if clinical drugs, might produce platelet activation in vivo.     

Ultrasound imaging in an animal model of vascular inflammation following balloon injury

Cardiovascular disease is a major cause of morbidity and mortality in the world and better prevention and treatment strategies are needed. Studies from this laboratory have shown that perfluorocarbon exposed sonicated dextrose albumin (PESDA) microbubbles bind to inflamed vasculature through interactions with scavenger receptors (SR). This current study details the use of PESDA as a tool for accessing and quantifying the extent of vascular inflammation. Angioplastied rat aortas were evaluated with low mechanical index microbubble imaging techniques contrast pulse sequencing (CPS); Siemens Acuson Sequoia 15L8, 7–15 MHz ultrasound probe with a mechanical index of 0.09 to detect microbubble binding. Real-time polymerase chain reaction (RT-PCR) analysis of angioplastied aortas demonstrated a significantly (p < 0.01) increased expression of both SRs and Interleukin 6 (IL-6). Vessel wall enhancement was quantified using densitometry of CPS ultrasound images and correlated with the upregulated expression of scavenger receptors, Toll-like receptors and IL-6. This study demonstrates that PESDA, in conjunction with CPS ultrasound, is an effective imaging technique to better detect early vascular inflammation and potential cardiovascular disease.     

Higher dextrose delivery via TPN related to the development of hyperglycemia in non-diabetic critically ill patients

The beneficial effects of total parenteral nutrition (TPN) in improving the nutritional status of malnourished patients during hospital stays have been well established. However, recent randomized trials and meta-analyses have reported an increased rate of TPN-associated complications and mortality in critically ill patients. The increased risk of complications during TPN therapy has been linked to the development of hyperglycemia, especially during the first few days of TPN therapy. This retrospective study was conducted to determine whether the amount of dextrose from TPN in the 1^st week in the intensive care unit (ICU) was related to the development of hyperglycemia and the clinical outcome. We included 88 non-diabetic critically ill patients who stayed in the medical ICU for more than two days. The subjects were 65 ± 16 years old, and the mean APACHE (Acute Physiology and Chronic Health Evaluation) II score upon admission was 20.9 ± 7.1. The subjects received 2.3 ± 1.4 g/kg/day of dextrose intravenously. We divided the subjects into two groups according to the mean blood glucose (BG) level during the 1^st week of ICU stay: < 140 mg/dl vs ≥ 140 mg/dl. Baseline BG and the amount of dextrose delivered via TPN were significantly higher in the hyperglycemia group than those in the normoglycemia group. Mortality was higher in the hyperglycemia group than in the normoglycemia group (42.4% vs 12.8%, P = 0.008). The amount of dextrose from TPN was the only significant variable in the multiple linear regression analysis, which included age, APACHE II score, baseline blood glucose concentration and dextrose delivery via TPN as independent variables. We concluded that the amount of dextrose delivered via TPN might be associated with the development of hyperglycemia in critically ill patients without a history of diabetes mellitus. The amount of dextrose in TPN should be decided and adapted carefully to maintain blood glucose within the target range.     

Flow cytometric detection of endothelial microparticles (EMP): Effects of centrifugation and storage alter with the phenotype studied

Introduction

Endothelial microparticles (EMP) are released into the circulation in case of endothelial disturbance, and are therefore increasingly investigated as a biomarker reflecting disease activity. Numerous pre-analytic methods have been proposed for their flow cytometric enumeration, but standardization is still lacking. In this study we evaluated the influence of centrifugation and storage conditions on EMP quantification.

Materials and Methods

Platelet-poor plasma (PPP) from 10 healthy volunteers was prepared by centrifugation at 1 550 g for 20 minutes twice. A first aliquot of PPP was analyzed immediately, a second after storage at 4 °C for 7 hours. A third and fourth aliquot were snap-frozen and stored at -80 °C for 7 and 28 days. A final aliquot was further centrifuged at 10 000 g for 10 minutes and analyzed immediately. EMP were defined as CD31+CD42b-, CD62E+, CD144+ or CD144+CD105+ particles, smaller than 1.0 µm.

Results

High speed centrifugation led to a significant loss of CD31+CD42b- EMP (p = 0.004). A good correlation between PPP and high speed centrifuged PPP was only found for CD144+ EMP (Kendall tau b = 0.611, p = 0.025).Storage at 4 °C did not affect EMP quantification. However, freezing at -80 °C increased CD31+CD42b- and CD62E+ EMP counts, and lowered CD144+ EMP (p < 0.05). Nevertheless, the agreement among the different storage conditions was relatively good (Kendall coefficient of concordance > 0.487; p < 0.05).

Conclusion

The flow cytometric detection of EMP varies with the centrifugation protocol and the storage method used, and these changes also depend on the phenotype studied. The results of this study caution against comparing study results gathered with different EMP laboratory protocols.     

高浓度葡萄糖注射液细菌内毒素的测定

50%的葡萄糖溶液可抑制鲎试剂凝集反应,干扰细菌内毒素的测定,本文使用中空纤维透析器,以双向超滤技术,将细菌内毒素与葡萄糖分离,降低了葡萄糖浓度,消除了葡萄糖对鲎试剂凝集反应的抑制作用,方法实用,操作简便,快速灵敏。     

Prevalence and diversity of filamentous fungi in the airways of cystic fibrosis patients – A Dutch,multicentre study

Background

Progressive lung injury in Cystic Fibrosis (CF) patients can lead to chronic colonization with bacteria and fungi. Fungal colonization is obtained from the environment which necessitates locally performed epidemiology studies. We prospectively analyzed respiratory samples of CF patients during a 3-year period, using a uniform fungal culture protocol, focusing on filamentous fungi and azole resistance in Aspergillus fumigatus.