Gracie Ong

Gelam honey inhibits lipopolysaccharide-induced endotoxemia in rats through the induction of heme oxygenase-1 and the inhibition of cytokines, nitric oxide, and high-mobility group protein B1.

Malaysian Gelam honey has anti-inflammatory and antibacterial properties, a high antioxidant capacity, and free radical-scavenging activity. Lipopolysaccharide (LPS) stimulates immune cells to sequentially release early pro- and anti-inflammatory cytokines and induces the synthesis of several related enzymes. The aim of this study was to investigate the effect of the intravenous injection of honey in rats with LPS-induced endotoxemia. The results showed that after 4h of treatment, honey reduced cytokine (tumor necrosis factor-α, interleukins 1β, and 10) and NO levels and increased heme oxygenase-1 levels. After 24h, a decrease in cytokines and NO and an increase in HO-1 were seen in all groups, whereas a reduction in HMGB1 occurred only in the honey-treated groups. These results support the further examination of honey as a natural compound for the treatment of a wide range of inflammatory diseases.

Severe bronchospasm during epidural anaesthesia

A case of severe bronchospasm occurring during epidural anaesthesia in a patient undergoing Caesarean section is described. The aetiology of the bronchospasm may have been related to sympathetic nervous blockade allowing unopposed parasympathetically mediated bronchoconstriction.

Percutaneous needle cricothyroidotomy with repetitive airway obstruction.

To develop a technique for needle cricothyrotomy that mimics the normal respiratory cycle (using repetitive obstruction of the upper airway and relatively low flow oxygen through small catheters), a controlled trial in three anesthetized dogs was performed. Oxygen from a standard bottle and pressure reducer was delivered through the cricothyroid membrane at 0.36 L/kg/min, which is metabolically equivalent to 0.2 L/kg/min in an adult human. The upper airway was obstructed until the chest rose and then was unobstructed to allow exhalation. The animals were ventilated for 5 minutes to allow equilibration. Arterial PCO2 was measured after 2-minute periods of apnea and 3 minutes of ventilation, each repeated four times. The procedure was repeated in three other dogs at a flow of 0.18 L/kg/min to simulate a 50% air leak. Cricothyroid ventilation at 0.36 L/kg/min lowered the PCO2 from 65 mm Hg to 43 mm Hg, F = 258, P = .004. All PCO2 after 25 minutes were in the normal range. Ventilation at 0.18 L/kg/min stabilized the PCO2 at approximately 1.5 times normal (67 mm Hg versus 79 mm Hg for the preceding apnea, F = 77, P = .013). Flow rates achievable with 18- to 20-gauge catheters and standard oxygen sources are adequate for cricothyroid ventilation when the airway is repetitively obstructed to allow a normal respiratory cycle.

CAFFEIC ACID PHENETHYL ESTER (CAPE): SCAVENGER OF PEROXYNITRITE IN VITRO AND IN SEPSIS MODELS

ABSTRACT Excessive free radical production by immune cells has been linked to cell death and tissue injury during sepsis. Peroxynitrite is a short-lived oxidant and a potent inducer of cell death that has been identified in several pathological conditions. Caffeic acid phenethyl ester (CAPE) is an active component of honeybee products and exhibits antioxidant, anti-inflammatory, and immunomodulatory activities. The present study examined the ability of CAPE to scavenge peroxynitrite in RAW 264.7 murine macrophages stimulated with lipopolysaccharide/interferon-&ggr; that was used as an in vitro model. Conversion of 123-dihydrorhodamine to its oxidation product 123-rhodamine was used to measure peroxynitrite production. Two mouse models of sepsis (endotoxemia and cecal ligation and puncture) were used as in vivo models. The level of serum 3-nitrotyrosine was used as an in vivo marker of peroxynitrite. The results demonstrated that CAPE significantly improved the viability of lipopolysaccharide/interferon-&ggr;–treated RAW 264.7 cells and significantly inhibited nitric oxide production, with effects similar to those observed with an inhibitor of inducible nitric oxide synthase (1400W). In addition, CAPE exclusively inhibited the synthesis of peroxynitrite from the artificial substrate SIN-1 and directly prevented the peroxynitrite-mediated conversion of dihydrorhodamine-123 to its fluorescent oxidation product rhodamine-123. In both sepsis models, CAPE inhibited cellular peroxynitrite synthesis, as evidenced by the absence of serum 3-nitrotyrosine, an in vivo marker of peroxynitrite. Thus, CAPE attenuates the inflammatory responses that lead to cell damage and, potentially, cell death through suppression of the production of cytotoxic molecules such as nitric oxide and peroxynitrite. These observations provide evidence of the therapeutic potential of CAPE treatment for a wide range of inflammatory disorders.

Gelam Honey Scavenges Peroxynitrite During the Immune Response

Monocytes and macrophages are part of the first-line defense against bacterial, fungal, and viral infections during host immune responses; they express high levels of proinflammatory cytokines and cytotoxic molecules, including nitric oxide, reactive oxygen species, and their reaction product peroxynitrite. Peroxynitrite is a short-lived oxidant and a potent inducer of cell death. Honey, in addition to its well-known sweetening properties, is a natural antioxidant that has been used since ancient times in traditional medicine. We examined the ability of Gelam honey, derived from the Gelam tree (Melaleuca spp.), to scavenge peroxynitrite during immune responses mounted in the murine macrophage cell line RAW 264.7 when stimulated with lipopolysaccharide/interferon-γ (LPS/IFN-γ) and in LPS-treated rats. Gelam honey significantly improved the viability of LPS/IFN-γ-treated RAW 264.7 cells and inhibited nitric oxide production—similar to the effects observed with an inhibitor of inducible nitric oxide synthase (1400W). Furthermore, honey, but not 1400W, inhibited peroxynitrite production from the synthetic substrate 3-morpholinosydnonimine (SIN-1) and prevented the peroxynitrite-mediated conversion of dihydrorhodamine 123 to its fluorescent oxidation product rhodamine 123. Honey inhibited peroxynitrite synthesis in LPS-treated rats. Thus, honey may attenuate inflammatory responses that lead to cell damage and death, suggesting its therapeutic uses for several inflammatory disorders.

Kidney Function Alters the Relationship between Postoperative Troponin T Level and Death

Cardiac troponin T (cTnT), even at low concentrations, is a risk factor for 30-day mortality in patients undergoing noncardiac surgery, but it is uncertain whether that risk is generalizable to patients with poor kidney function. We, therefore, evaluated the relationship between cTnT concentration and kidney function on the outcome of 30-day mortality in a post hoc analysis of a prospective cohort study of patients undergoing noncardiac surgery. cTnT was measured for 3 days after surgery and considered abnormal if the peak was ≥0.02 ng/ml. Of the included 14,037 patients, 267 (1.9%) patients died within 30 days of surgery. The adjusted hazard ratios for death with an abnormal cTnT concentration were 4.37 (95% confidence intervals [95% CI], 3.21 to 6.22), 6.15 (95% CI, 2.95 to 140.9), 6.30 (95% CI, 3.12 to 21.23), 1.33 (95% CI, 0.56 to 4.85), and 1.46 (95% CI, 0.46 to 9.21) for eGFR≥60, 45 to <60, 30 to <45, 15 to <30, and <15 ml/min per 1.73 m(2) or on dialysis, respectively. Compared with patients with eGFR≥60 ml/min per 1.73 m(2), the adjusted hazard ratio was significantly lower for patients with eGFR=15 to <30 ml/min per 1.73 m(2) (interaction P value=0.02). Redefining abnormal cTnT concentration as ≥0.03 ng/ml or a change of ≥0.02 ng/ml did not alter results. Because the risk associated with postoperative cTnT levels may be different for patients with eGFR<30 ml/min per 1.73 m(2), additional research is required to determine how to interpret perioperative cTnT values for patients with low kidney function.

Use of the endotracheal tube as a pharyngeal airway.

An animal study was conducted to determine whether an endotracheal tube placed above the vocal cords in the pharynx can be used for ventilation. Four dogs undergoing general anesthesia were ventilated through an endotracheal tube placed in the oropharynx with the remainder of the airway occluded. Ventilation was performed for 3 of every 5 minutes during a total period of 25 minutes. Arterial PCO2 was compared in sequential samples alternating apnea and pharyngeal ventilation. Ventilation via the pharyngeal tube significantly reduced the arterial PCO2 from 48.8 mm Hg (SD 16) during apnea to 30.1 mm Hg (SD 10.9). Repeated measures ANOVAF = 8.2, P < .001. All PCO2 levels during ventilation were in or below the normal range of 34 to 46. Provided that the mouth and nose can be sealed, an endotracheal tube placed in the pharynx above the cords allows for adequate ventilation.

Stimulation of β-adrenergic receptors plays a protective role via increased expression of RAF-1 and PDX-1 in hyperglycemic rat pancreatic islet (RIN-m5F) cells

Introduction It is a widely held view that a progressive reduction of beta-cell mass occurs in the progression of diabetes. RAF-1 kinase and pancreas duodenal homeobox 1 (PDX-1) are major factors that promote survival of cells and maintain normal insulin functions. In this study we investigated the effect of a β-adrenergic receptor agonist and antagonist on RAF-1 and PDX-1, and their respective effects on apoptosis and insulin release in RIN-m5F cells. Material and methods RIN-m5F cells were cultured in normal (5 mM) and high (25 mM) glucose to mimic diabetic conditions, followed by treatment with 5 µM, 10 µM and 20 µM of isoproterenol and isoproterenol + propranolol for 6, 12 and 24 h. Western blotting and reverse transcription analysis were performed to examine the expression of RAF-1 and PDX-1. Annexin-V-FITC and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assays were used to investigate apoptosis. ELISA was used to measure insulin levels. Reverse transcription polymerase chain reaction was conducted to investigate the expression of genes. Results Stimulation of β-adrenergic receptors with isoproterenol significantly induced RAF-1 and PDX-1 genes in a concentration-dependent and time-independent manner. Changes were significant both at protein and mRNA levels. Up-regulation of RAF-1 and PDX-1 was accompanied by improved insulin levels and reduced apoptosis. Concentrations of 10 µM and 20 µM for 12 and 24 h were more effective in achieving significant differences in the experimental and control groups. Propranolol reversed the effect of isoproterenol mostly at maximum concentrations and time periods. Conclusions A positive effect of a β-adrenergic agonist on RAF-1 and PDX-1, reduction in β-cell apoptosis and improved insulin contents can help to understand the pathogenesis of diabetes and to develop novel approaches for the β-cell dysfunction in diabetes.