Preferential utilization of inorganic polyphosphate over other bioavailable phosphorus sources by the model diatoms Thalassiosira spp.

Polyphosphates and phosphomonoesters are dominant components of marine dissolved organic phosphorus (DOP). Collectively, DOP represents an important nutritional phosphorus (P) source for phytoplankton growth in the ocean, but the contribution of specific DOP sources to microbial community P demand is not fully understood. In a prior study, it was reported that inorganic polyphosphate was not bioavailable to the model diatoms Thalassiosira weissflogii and Thalassiosira pseudonana. However, in this study, we show that the previous finding was a misinterpretation based on a technical artefact of media preparation and that inorganic polyphosphate is actually widely bioavailable to Thalassiosira spp. In fact, orthophosphate, inorganic tripolyphosphate (3polyP), adenosine triphosphate (ATP) and adenosine monophosphate supported equivalent growth rates and final growth yields within each of four strains of Thalassiosira spp. However, enzyme activity assays revealed in all cultures that cell-associated hydrolysis rates of 3polyP were typically more than ~10-fold higher than degradation of ATP and the model phosphomonoester compound 4-methylumbelliferyl phosphate. These results build on prior work, which showed the preferential utilization of polyphosphates in the cell-free exudates of Thalassiosira spp., and suggest that inorganic polyphosphates may be a key bioavailable source of P for marine phytoplankton.

Gabapentin in the Management of Pain following Tonsillectomy: A Randomized Double-Blind Placebo-Controlled Trial.

Objective To determine if a single dose of oral gabapentin given prior to tonsillectomy decreases postoperative morbidity. Study Design Prospective randomized double-blind placebo-controlled trial. Setting Southern District Health Board University Hospitals, New Zealand, over a 10-month period. Subjects and Methods Seventy-three adults undergoing tonsillectomy were randomized to receive either a single preoperative dose of oral gabapentin (600 mg) or placebo. A standard analgesic protocol was prescribed for 14 postoperative days. The primary outcome was a patient-assigned visual analog scale pain score during rest and swallow; secondary outcomes were analgesic consumption, nausea, vomiting, and return to normal diet and activities. Complications and adverse effects were also recorded. Results Thirty-seven participants were allocated to the placebo group and 36 to the gabapentin group. After withdrawals, data were analyzed from 31 in the placebo group and 27 in the gabapentin group. Pain scores between groups were not significantly different within the first 6 hours. The gabapentin group recorded significantly higher pain scores between days 5 and 10 (maximal difference, day 8: 17.6 mm; effect size, -8.87; P = .03; 95% CI, -16.883 to -0.865). There was no significant difference in swallow pain scores or early postoperative fentanyl consumption. Consumption of paracetamol ( P = .01 at day 13 and P = .004 at day 14) and codeine ( P < .05 at days 3-5, 7, 8, 10, 14) was higher in the gabapentin group. No significant difference between groups was found for the other outcomes. Conclusions Preemptive gabapentin (600 mg) was associated with greater postoperative pain scores and analgesic consumption following adult tonsillectomy when compared with placebo.

Gabapentin for Perioperative Analgesia in Otorhinolaryngology-Head and Neck Surgery: Systematic Review.

OBJECTIVE: Recent research has investigated the role of gabapentin in perioperative pain relief in otorhinolaryngology-head and neck surgery. This review aims to identify whether sufficient evidence exists for the routine use of gabapentin in the perioperative setting. DATA SOURCES: MEDLINE, Cochrane CENTRAL, EMBASE, and Google Scholar. REVIEW METHODS: A comprehensive systematic search was performed with keywords for articles up to November 2015. The systematic review included all randomized, placebo-, and active-controlled trials investigating the role of perioperative gabapentin for pain in otorhinolaryngology-head and neck surgery. The studies were assessed for risk of bias and selected and reviewed by the main author. Selected trials were required to have data in the form of pain intensity scores, analgesic consumption, adverse effects, or return to normal function. RESULTS: A total of 14 randomized controlled trials were included, of which 4 had an active control. The placebo-controlled trials included 4 for tonsillectomy, 3 for rhinology, and 3 for thyroidectomy. These studies were not suitable for meta-analysis. Trial quality involving gabapentin in tonsillectomy surgery is variable. The higher-quality studies reported significantly reduced analgesic consumption in the gabapentin groups, with the effect on pain scores less clear. There was a significant benefit, within the first 24 hours, in pain and analgesic consumption as compared with placebo favoring the gabapentin groups following rhinologic and thyroid surgery. CONCLUSION: Overall, gabapentin appears to have a significant beneficial effect on perioperative pain relief and analgesic consumption in otorhinolaryngology-head and neck surgery procedures within the first 24 hours.

A case of subglottic and diffuse tracheal stenoses appearing responsive to macrolide therapy.

We present an atypical case of subglottic stenosis with diffuse tracheal stenoses in a child responsive only to steroid and azithromycin (AZI) therapy. A 12-year-old boy presented with acute biphasic stridor on the background of an 18-month history of progressive shortness of breath, decreased exercise tolerance and snoring. Subsequent laryngoscopy and bronchoscopy revealed granulation tissue in the subglottic area, two circumferential stenoses of the trachea and a number of fibrous bands at the carina and at the aperture if the right main bronchus were seen. A battery of serological and histological investigations did not reveal a specific aetiology. In the acute phase this patient only responded to steroid therapy. In the medium term, repeat laryngoscopies were performed with sharp division of stenotic bands and balloon dilatation. The patient's condition was unresponsive to non-steroidal anti-inflammatories, multiple first-line antibiotics, and surgical treatment of the tracheal lesions. However definitive treatment was found with the macrolide antibiotic AZI used for its anti-inflammatory properties. This highly unusual case of diffuse tracheal stenoses in a child proved to be a management challenge. Definitive treatment was found with the use of AZI. From our literature search this appears to be the first reported case of AZI successfully treating subglottic and tracheal stenoses.

Enhancing the ecological risk assessment process.

The Ecological Processes and Effects Committee of the US Environmental Protection Agency Science Advisory Board conducted a self-initiated study and convened a public workshop to characterize the state of the ecological risk assessment (ERA), with a view toward advancing the science and application of the process. That survey and analysis of ERA in decision making shows that such assessments have been most effective when clear management goals were included in the problem formulation; translated into information needs; and developed in collaboration with decision makers, assessors, scientists, and stakeholders. This process is best facilitated when risk managers, risk assessors, and stakeholders are engaged in an ongoing dialogue about problem formulation. Identification and acknowledgment of uncertainties that have the potential to profoundly affect the results and outcome of risk assessments also improves assessment effectiveness. Thus we suggest 1) through peer review of ERAs be conducted at the problem formulation stage and 2) the predictive power of risk-based decision making be expanded to reduce uncertainties through analytical and methodological approaches like life cycle analysis. Risk assessment and monitoring programs need better integration to reduce uncertainty and to evaluate risk management decision outcomes. Postdecision audit programs should be initiated to evaluate the environmental outcomes of risk-based decisions. In addition, a process should be developed to demonstrate how monitoring data can be used to reduce uncertainties. Ecological risk assessments should include the effects of chemical and nonchemical stressors at multiple levels of biological organization and spatial scale, and the extent and resolution of the pertinent scales and levels of organization should be explicitly considered during problem formulation. An approach to interpreting lines of evidence and weight of evidence is critically needed for complex assessments, and it would be useful to develop case studies and/or standards of practice for interpreting lines of evidence. In addition, tools for cumulative risk assessment should be developed because contaminants are often released into stressed environments.