Gad Shaked

Involvement of adenosine in the antiinflammatory action of ketamine

Background:Ketamine is an anesthetic drug. Subanesthetic doses of ketamine have been shown to reduce interleukin-6 concentrations after surgery and to reduce mortality and the production of tumor necrosis factor α and interleukin 6 in septic animals. Similarly, adenosine was shown to reduce tumor necrosis factor α and mortality of septic animals. The aim of this study was to determine whether adenosine mediates the antiinflammatory effects of ketamine. Methods:Sepsis was induced in mice by lipopolysaccharide or Escherichia coli inoculation. Leukocyte recruitment and cytokine concentrations were used as inflammation markers. Adenosine concentrations were assayed by high-performance liquid chromatography, and the involvement of adenosine in the effects of ketamine was demonstrated by adenosine receptor agonists and antagonists. Results:Ketamine markedly reduced mortality from sepsis, leukocyte recruitment, and tumor necrosis factor-α and interleukin-6 concentrations. Ketamine administration in mice and rats was associated with a surge at 20–35 min of adenosine in serum (up to 5 &mgr;m) and peritoneal fluid. The adenosine A2A receptor agonist CGS-21680 mimicked the effect of ketamine in peritonitis, whereas the A2A receptor antagonists DMPX and ZM 241385 blocked its antiinflammatory effects. In contrast, A1 and A3 receptor antagonists had no effect. ZM 241385 reversed the beneficial effect of ketamine on survival from bacterial sepsis. Conclusions:The current data suggest that the sepsis-protective antiinflammatory effects of ketamine are mediated by the release of adenosine acting through the A2A receptor.

Measurement of circulating cell-free DNA levels by a new simple fluorescent test in patients with primary colorectal cancer.

Elevated circulating cell-free DNA (CFD) levels were found in patients with cancer. The standard CFD assays are work-intensive and expensive. The aim was to evaluate in patients with cancer a new simple CFD assay. In mice inoculated with cancer cells, CFD levels correlated with tumor size. Compared with healthy subjects, 38 patients with colorectal cancer (CRC) had higher preoperative CFD levels (798 ± 409 vs 308 ± 256 ng/mL; P < .0001). Compared with patients free of disease at 1 year, CFD levels were elevated in patients who remained with disease or died (DD). CFD correlated with DD (P = .033), and a combined index of carcinoembryonic antigen × CFD exhibited a better correlation to DD than did pathologic staging (P = .0027 vs P = .0065). For patients with CRC, CFD levels were prognostic of death and disease. A large prospective study will need to be performed to truly evaluate the efficacy of this method for early detection, follow-up, and evaluation of patient response to treatment.

Anti-Inflammatory Preconditioning by Agonists of Adenosine A1 Receptor

Background Adenosine levels rise during inflammation and modulate inflammatory responses by engaging with four different G protein-coupled receptors. It is suggested that adenosine exhibits pro-inflammatory effects through its A1 receptor (A1R), and anti-inflammatory effects through A2A receptor (A2AR). Therefore, understanding of the mechanisms that govern adenosine receptor regulation may advance treatment of various inflammatory disorders. We previously reported that peak A1R expression during leukocyte recruitment, is followed by a peak in A2AR during inflammation resolution. Principal Findings Here, we examined whether A1R activation sequentially induces A2AR expression and by this reverses inflammation. The effect of adenosine on A1R mediated A2AR expression was examined in peritoneal macrophages (PMΦ) and primary peritoneal mesothelial cells (PMC) in vitro. Induction of A2AR was inhibited by pertussis toxin (PTX) and partly dependent on A2AR stimulation. Administration of A1R agonists to healthy mice reduced A1R expression and induced A2AR production in PMC. Mice that were preconditioned with A1R agonists 24 hours before E. coli inoculation exhibited decreased TNFα and IL-6 sera levels and reduced leukocytes recruitment. Preconditioning was blocked by pretreatment with A1R antagonist, as well as, or by late treatment with A2AR antagonist, and was absent in A2AR−/− mice. Conclusions Our data suggest that preconditioning by an A1R-agonist promotes the resolution of inflammation by inducing the production of A2AR. Future implications may include early treatment during inflammatory disorders or pretreatment before anticipated high risk inflammatory events, such as invasive surgery and organ transplantation.

Ketamine improves survival in burn injury followed by sepsis in rats

Ketamine was reported to decrease cytokine production and improve survival after Escherichia coli-induced sepsis. We examined whether ketamine decreased interleukin (IL)-6 production and improved survival after 1) burn injury or 2) burn injury combined with sepsis (E. coli) at 24 h. Ketamine (10 mg/kg) or saline was given at 1 h after burn injury (G 1, 2, 5, 6), 24 h after burn injury (G 3, 4), or at E. coli inoculation (G 7, 8). Mortality was recorded for 7 days and IL-6 was measured in serum at 6 h after burn (G 1–2), 30 h after burn (G 3–4), or 6 h after sepsis (30 h after burn) (G 5–8). Burn injury only: Ketamine given immediately (1 h) after burn injury but not 24 h after, decreased the burn-induced increase of IL-6 but did not improve survival. Burn injury + sepsis: Ketamine given immediately after burn injury did not significantly decrease the sepsis-induced increase of IL-6 or improve survival. In contrast, ketamine given immediately after sepsis significantly improved survival (46.1% versus 13.3%, P = 0.008) and decreased IL-6 production (72,640 ± 40,990 vs 332,300 ± 32,300 pg/mL, P = 0.008). We conclude that ketamine therapy improves survival in burn injury followed by sepsis. This beneficial effect is probably achieved through interference with the inflammatory cascade, as evidenced by attenuation of the proinflammatory marker IL-6.

Intermittent cycles of remote ischemic preconditioning augment diabetic foot ulcer healing

The morbidity and mortality caused by diabetic foot ulcer (DFU) are still significant. Conservative treatment of DFU is often ineffective. Treatment modalities using stem cells directly into the DFU or systematically have been introduced recently. Ischemic preconditioning (IPC) has been proved to be a cheap, simple, and safe method which can augment stem cells number in the peripheral blood circulation. This studys purpose was to test whether IPC can improve DFU healing. Forty diabetic patients were enrolled and divided into study and control groups. All patients received their regular treatment. The study group patients received in addition brief, transient cycles of IPC while the control group patients received a sham procedure only. The procedure was repeated every 2 weeks to complete a follow‐up period of 6 weeks. The ulcers were photographed to measure wound area, and the degree of granulation tissue was assessed. No serious adverse events were noted. Twenty‐two patients from the study group and 12 from the control group completed the entire follow‐up. The ratio of patients who reached complete healing of their ulcer was 9/22 (41%) in the study group compared with 0/12 (0%) in the control group, p = 0.01. Furthermore, the mean remaining ulcer area at the end of the follow‐up was significantly smaller in the study group, 25 ± 6% of the initial area vs. 61 ± 10% in the control group, p = 0.007. The degree of granulation increased after one cycle of treatment in 8/24 (33%) study patients compared to 3/16 (19%) in the control group, p = 0.47. Remote, repeated IPC significantly improves the healing of DFU. This simple, safe, inexpensive treatment method should be considered to be routinely applied to diabetic patients with DFU in addition to other regular treatment modalities.

Distended urinary bladder and diverticulum—a rare cause of large-bowel obstruction

A 76-year-old man presented to the emergency department with diffuse abdominal pain and constipation. In the few months before this admission the patient had complained of strenuous micturition. The diagnostic work-up included a plain abdominal radiograph and an abdominal computed tomography scan that revealed large-bowel obstruction with a rare cause. The colonic obstruction was secondary to external compression of the rectosigmoid colon against the sacrum by a distended bladder and diverticulum. The immediate management was insertion of an indwelling urinary catheter that resulted in quick relief of the obstruction. Later the patient underwent surgery to remove an enlarged benign prostatic adenoma, which was the underlying cause of the bladder distention.

Admission Cell Free DNA as a Prognostic Factor in Burns: Quantification by Use of a Direct Rapid Fluorometric Technique

Background. Despite great advances in the treatment of burn patients, useful prognostic markers are sparse. During the past years there has been increasing interest in circulating plasma cell free DNA as a potential marker for tissue injury. We have developed a rapid direct fluorescent assay for cell free DNA quantification that allows obtaining accurate, fast, and inexpensive measurements. Objective. To use this technique for measuring plasma cell free DNA levels in burn patients and to further explore the use of cell free DNA as a potential marker of patient outcome in burns. Methods. Cell free DNA levels obtained from 14 burn victims within 6 hours of injury and 14 healthy controls were quantified by a direct rapid fluorometric assay. Results. Patient admission cell free DNA levels were significantly elevated compared with that of controls (1797 ± 1523 ng/mL versus 374 ± 245 ng/mL, P = 0.004). There are statistically significant correlations between cell free DNA admission levels and burn degree (Spearmans correlation = 0.78, P = 0.001), total body surface area (Spearmans correlation = 0.61, P = 0.02), and total burn volume (Spearmans correlation = 0.64, P = 0.014). Conclusions. Admission cell free DNA levels can serve as a prognostic factor in burns and future routine use can be made possible by use of our direct rapid fluorometric assay.

Oral drug therapy following bariatric surgery: an overview of fundamentals, literature and clinical recommendations

Bariatric surgery is the most effective solution for severe obesity and obesity with comorbidities, and the number of patients going through bariatric surgery is rapidly and constantly growing. The modified gastrointestinal anatomy of the patient may lead to significant pharmacokinetic alterations in the oral absorption of drugs after the surgery; however, because of insufficient available literature and inadequate awareness of the medical team, bariatric surgery patients may be discharged from the hospital with insufficient instructions regarding their medication therapy. In this article, we aim to present the various mechanisms by which bariatric surgery may influence oral drug absorption, to provide an overview of the currently available literature on the subject, and to draw guidelines for the recommendations bariatric surgery patients should be instructed before leaving the hospital. To date, and until more robust data are published, it is essential to follow and monitor patients closely for safety and efficacy of their medication therapies, both in the immediate and distant time post‐surgery.

Regulation of adenosine system at the onset of peritonitis

BACKGROUND Adenosine, a potent regulator of inflammation, is produced under stressful conditions due to degradation of ATP/ADP by the ectoenzymes CD39 and CD73. Adenosine is rapidly degraded by adenosine deaminase (ADA) or phosphorylated in the cell by adenosine kinase (AK). From four known receptors to adenosine, A(1) (A(1)R) promotes inflammation by a G(i)-coupled receptor. We have previously shown that A(1)R is up-regulated in the first hours following bacterial inoculation. The aim of the current study is to characterize the inflammatory mediators that regulate adenosine-metabolizing enzymes and A(1)R at the onset of peritonitis. METHODS Peritonitis was induced in CD1 mice by intraperitoneal injection of Escherichia coli. TNFalpha and IL-6 levels were determined in peritoneal fluid by enzyme-linked immunosorbent assay. Adenosine-metabolizing enzymes and the A(1)R mRNA or protein levels were analyzed by quantitative PCR or by Western blot analysis, respectively. RESULTS We found that CD39 and CD73 were up-regulated in response to bacterial stimuli (6-fold the basal levels), while AK and ADA mRNA levels were down-regulated. Cytokine production and leukocyte recruitment were enhanced (2.5-fold) by treatment with an A(1)R agonist (2-chloro-N(6)-cyclopentyladenosine, 0.1 mg/kg) and reduced (2.5-3-fold) by the A(1)R antagonist (8-cyclopentyl-1, 3-dipropylxanthine, 1 mg/kg). In contrast to lipopolysaccharide, IL-1, TNF and IFNgamma, only low IL-6 levels (0.01 ng/ml), in the presence of its soluble IL-6R (sIL-6R), were found to promote A(1)R expression on mesothelial cells. In mice, administration of neutralizing antibody to IL-6R or soluble gp130-Fc (sgp130-Fc) blocked peritoneal A(1)R up-regulation following inoculation. CONCLUSION Bacterial products induce the production of adenosine by up-regulation of CD39 and CD73. Low IL-6-sIL-6R up-regulates the A(1)R to promote efficient inflammatory response against invading microorganisms.

Incidence and injury characteristics of traumatic brain injury: Comparison between children, adults and seniors in Israel

Abstract Aim: To assess the incidence and injury characteristics of hospitalized trauma patients diagnosed with TBI. Methods: A retrospective study of all injured hospitalized patients recorded in the National Trauma Registry at 19 trauma centres in Israel between 2002–2011. Incidence and injury characteristics were examined among children, adults and seniors. Results: The annual incidence rate of hospitalized TBI for the Israeli population in 2011 was 31.8/100 000. Age-specific incidence was highest among seniors with a dramatic decrease in TBI-related mortality rate among them. Adults, in comparison to children and seniors, had higher rates of severe TBI, severe and critical injuries, more admission to the intensive care unit, underwent surgery, were hospitalization for more than 2 weeks and were discharged to rehabilitation. After adjusting for age, gender, ethnicity, mechanism of injury and injury severity score, TBI-related in-hospital mortality was higher among seniors and adults compared to children. Conclusion: Seniors are at high risk for TBI-related in-hospital mortality, although adults had more severe and critical injuries and utilized more hospital resources. However, seniors showed the most significant reduction in mortality rate during the study period. Appropriate intervention programmes should be designed and implemented, targeted to reduce TBI among high risk groups.