Ethanol alters the expression of ion channel genes in Daphnia pulex.

BACKGROUND: Heavy drinking can increase heart rate and blood glucose, induce hypoxic tolerance, impair brain cognitive functions, and alter gene expressions. These phenomena may occur even in response to small dose of ethanol exposure or during its withdrawal. OBJECTIVES: To evaluate whether persistent low concentrations of ethanol exposure affect organism function and the gene expressions of ion channels. METHODS: Daphnids were randomized to receive placebo 300 min, 2 mM ethanol 300 min, or 2 mM ethanol 240 min and then placebo 60 min. Heart rate, glucose levels, phototactic behavior, and hypoxic tolerance were recorded during experiment. At the end of the study, changes in the mRNA levels of ion channel genes were assessed in response to exposure to ethanol using quantitative polymerase chain reaction (PCR) techniques. RESULTS: Heart rate was reversibly increased by ethanol withdrawal and returned to basal levels upon re-exposure to ethanol. Fifteen of 120 ion channel transcripts were affected by persistent ethanol exposure. Neither ethanol withdrawal nor persistent exposures showed an effect on blood glucose, phototactic behavior, or hypoxic tolerance. CONCLUSIONS: Small doses of ethanol can increase heart rate and alter gene expression of multiple ion channels in Daphnia pulex. Affected ion channel genes may assist in understanding the mechanism of ethanol adaptation and tolerance.

Establishment of An Alloxan-induced Diabetes Model in Daphnia Pulex.

Objective To establish a Daphnia model of alloxan-induced diabetes. Methods Daphnia were exposed to three different concentrations of alloxan (3, 5, and 10 mmol/L) for 30 minutes. Blood glucose and survival rate were recorded for 72 hours after alloxan insult. Sequence analysis and phylogenetic inference for glucose transporters (GLUT) were clustered with the maximum-likelihood method. Using reverse transcription and quantitative polymerase chain reaction techniques, we investigated the transcriptional changes of GLUT at 12 hours after alloxan (5 mmol/L) exposure. Results Compared with control, 3 mmol/L, and 5 mmol/L as well as 10 mmol/L alloxan initially induced transient blood glucose decline by 15% for 2 hours and 12 hours respectively. In Daphnia with 5 and 10 mmol/L alloxan, their blood glucose was persistently raised by about 150% since after 24-hour insult. Survival rate of Daphnia exposure to alloxan with concentrations of 3, 5, and 10 mmol/L were 90%, 75%, and 25% respectively. We predicted seven GLUT genes in the Daphnia genome and successfully amplified them using real-time polymerase chain reaction. Two of seven GLUT transcripts were down-regulated in Daphnia with 5 mmol/L alloxan-induced diabetes. Conclusion Alloxan-induced diabetes model was successfully established in the Daphnia pulex, suggesting diabetes-relevant experiments can be conducted using Daphnia.

Dorsal penile nerve block for rigid cystoscopy in men: study protocol for a randomized controlled trial.

BACKGROUND: Pain is common in men undergoing rigid cystoscopy. Even with the application of a lubricant containing 2 % lidocaine, about 76 % of men suffer from mild to severe pain when undergoing rigid cystoscopy. The most painful part of the procedure for men is when the cystoscope passes through the membranous urethra. Song et al. (Neurourol Urodyn 29:592-5, 2010) did autopsies on males and found that the dorsal nerve of the penis (DNP), the terminal branch of the pudendal nerve, innervates the membranous urethra in 53.3 % of specimens. In addition, the urethral mucosa has branches of innervated DNP. Dorsal penile nerve block (DPNB) is usually used for circumcision in children, and it has been shown to provide effective analgesia for penile surgeries. In this study, we hypothesized that DPNB could reduce the overall pain level in men during rigid cystoscopy. METHODS/DESIGN: The trial is a prospective, randomized, double-blind, placebo-controlled, single-center trial to evaluate the effectiveness and safety of DPNB in analgesia for men undergoing rigid cystoscopy. Participants will be enrolled and randomly allocated into one of three groups according to the different analgesia regimens: 1) tetracaine gel group (DPNB with saline), 2) DPNB group (DPNB with ropivacaine plus plain lubricant), 3) combination group (DPNB with ropivacaine plus tetracaine gel). The primary outcome of this study is the visual analog scale (VAS, 0-10) for pain at cystoscopic inspection of the external sphincter. VAS scores evaluated at other time points serve as secondary outcomes. Vital signs are secondary outcomes that address the discomfort and pain during the procedure. Furthermore, the incidence of adverse events as secondary outcomes will also be recorded for evaluation of the safety of DPNB in rigid cystoscopy. Clinical assessments will be evaluated prior to DPNB, at administration of the lubricant gel, at cystoscopic inspection of the penile and bulbar urethra, external sphincter, prostate, and bladder, as well as at withdrawal of the cystoscope. DISCUSSION: This research will determine the effectiveness and safety of DPNB in men undergoing rigid cystoscopy. The results of this trial may have important implications for exploring the role of DPNB in analgesia for cystoscopy in men. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02502487 (6 Jul 2015).

Isoflurane pre-treatment before cardiopulmonary bypass alleviates neutrophil accumulation in dog lungs.

OBJECTIVE: This study investigated the effect of isoflurane pretreatment on cardiopulmonary bypass (CPB)-related lung injury. METHODS: Twelve dogs were randomly divided into two groups of six each. In one group, 1.0 minimum alveolar concentration (MAC) of isoflurane was dministered for 30 min before CPB, while the control group received no anaesthetic. Both groups then underwent 100 min of mild hypothermic CPB with 60-min aortic cross clamping. Haemodynamic parameters, respiratory mechanics and alveolar arterial oxygen difference (AaDO2) were measured during the experiment. One hundred and fifty minutes after CPB, lung tissue samples from the non-dependent and dependent portions of the left and right lungs were harvested for polymorphonulear leukocyte (PMNs) counts. RESULTS: Following CPB, within the control group, pulmonary vascular resistance (PVR) was significantly increased at 60, 120 and 180 min after declamping, AaDO2 deteriorated at 180 min post-declamping, and dynamic lung compliance (DLC) was reduced dramatically after declamping. Isoflurane pretreatment before CPB significantly reduced PVR compared to the controls. AaDO2 was impaired at 180 min after declamping and DLC was decreased after declamping within the isoflurane group. No differences in AaDO2 and DLC were found between the isoflurane and control groups. At 180 min after declamping, the PMN count in both the non-dependent and dependent regions of the isoflurane pre-treated lungs was significantly lower than that of the controls. CONCLUSIONS: Our results suggest that 30-min pre-treatment with 1.0 MAC isoflurane before CPB caused a reduction in PMN accumulation in the dog lungs, inhibition of increases in PVR, and it did not affect AaDO2 in the early post-CPB stage.