Optimized cryopreservation of mixed microbial communities for conserved functionality and diversity

The use of mixed microbial communities (microbiomes) for biotechnological applications has steadily increased over the past decades. However, these microbiomes are not readily available from public culture collections, hampering their potential for widespread use. The main reason for this lack of availability is the lack of an effective cryopreservation protocol. Due to this critical need, we evaluated the functionality as well as the community structure of three different types of microbiomes before and after cryopreservation with two cryoprotective agents (CPA). Microbiomes were selected based upon relevance towards applications: (1) a methanotrophic co-culture (MOB), with potential for mitigation of greenhouse gas emissions, environmental pollutants removal and bioplastics production; (2) an oxygen limited autotrophic nitrification/denitrification (OLAND) biofilm, with enhanced economic and ecological benefits for wastewater treatment, and (3) fecal material from a human donor, with potential applications for fecal transplants and pre/probiotics research. After three months of cryopreservation at −80°C, we found that metabolic activity, in terms of the specific activity recovery of MOB, aerobic ammonium oxidizing bacteria (AerAOB) and anaerobic AOB (AnAOB, anammox) in the OLAND mixed culture, resumes sooner when one of our selected CPA [dimethyl sulfoxide (DMSO) and DMSO plus trehalose and tryptic soy broth (DMSO+TT)] was added. However, the activity of the fecal community was not influenced by the CPA addition, although the preservation of the community structure (as determined by 16S rRNA gene sequencing) was enhanced by addition of CPA. In summary, we have evaluated a cryopreservation protocol that succeeded in preserving both community structure and functionality of value-added microbiomes. This will allow individual laboratories and culture collections to boost the use of microbiomes in biotechnological applications.

The effect of diabetic neuropathy on foot bones: a systematic review and meta-analysis

AIMS

It is proposed that diabetic neuropathy may affect peripheral bone. Direct innervation of bone as well as neural control over its vascular supply and muscular influences may be affected by diabetes-induced peripheral neuropathies. Associated changes to bone may contribute to the occurrence of foot bone pathology in this population. This systematic review aims to examine the literature related to the effect of diabetic neuropathy on foot bones.

METHODS

Studies examining relationships between neuropathy and indicators of bone health (e.g. bone mineral density) in populations with diabetes were sought. Relevant publications were obtained from searches in MEDLINE, CINAHL and Embase in the period up to March 2013. Meta-analysis was performed using a random effects model in the statistical package Stata version 12.1.

RESULTS

Ten studies met the inclusion criteria and were included in the narrative synthesis. All studies were cross-sectional or case-control in design. Four of the 10 included studies found results indicating poorer bone health in those with diabetes and neuropathy compared with those with diabetes without neuropathy. Seven of the 10 studies were able to be included in a meta-analysis. The mean pooled effect was -0.36 (95% CI -0.76 to 0.04; P = 0.08), indicating a non-significant trend towards poorer bone health in those with diabetic neuropathy.

CONCLUSIONS

We did not find a significant relationship between presence of neuropathy in those with diabetes and poorer peripheral bone health. However, methodological limitations of the included studies mean further research is required to investigate this theoretical relationship.

Self administration of oxycodone by adolescent and adult mice affects striatal neurotransmitter receptor gene expression

Illicit use of prescription opioid analgesics (e.g., oxycodone) in adolescence is a pressing public health issue. Our goal was to determine whether oxycodone self administration differentially affects striatal neurotransmitter receptor gene expression in the dorsal striatum of adolescent compared to adult C57BL/6J mice. Groups of adolescent mice (4 weeks old, n=12) and of adult mice (11 weeks old, n=11) underwent surgery during which a catheter was implanted into their jugular veins. After recovering from surgery, mice self administered oxycodone (0.25 mg/kg/infusion) 2 h/day for 14 consecutive days or served as yoked saline controls. Mice were sacrificed within 1h after the last self-administration session and the dorsal striatum was isolated for mRNA analysis. Gene expression was analyzed with real time PCR using a commercially available neurotransmitter receptor PCR array containing 84 genes. We found that adolescent mice self administered less oxycodone than adult mice over the 14 days. Monoamine oxidase A (Maoa) and neuropeptide Y receptor 5 mRNA levels were lower in adolescent mice than in adult mice without oxycodone exposure. Oxycodone self administration increased Maoa mRNA levels compared to controls in both age groups. There was a positive correlation of the amount of oxycodone self administered in the last session or across 14 sessions with Maoa mRNA levels. Gastrin-releasing peptide receptor mRNA showed a significant Drug × Age interaction, with point-wise significance. More genes in the dorsal striatum of adolescents (19) changed in response to oxycodone self administration compared to controls than in adult (4) mice. Overall, this study demonstrates that repeated oxycodone self administration alters neurotransmitter receptors gene expression in the dorsal striatum of adolescent and adult mice.

The yield and cost of colonoscopy in patients with metastatic cancer of unknown primary

BACKGROUND

Although gastroenterologists are asked to perform colonoscopy in patients with metastatic cancer of unknown primary (MCUP), studies evaluating this practice are lacking.

AIM

To determine the yield and cost of colonoscopy in patients referred for colonoscopy with an indication of MCUP.

METHODS

We prospectively and retrospectively assessed colonoscopies performed from 2000 to 2011 at a county, a university, and a Veterans Administration medical centre to identify patients referred for colonoscopy for the indication of MCUP. Exclusion criteria included overt or occult bleeding, iron-deficiency anaemia, familial-colon-cancer syndrome, prior colon cancer, imaging suggesting colorectal lesion, and palpable rectal mass. Outcomes were the number of primary colon cancers and costs based on 2012 Medicare reimbursements.

RESULTS

Two (1%) of the 160 patients meeting enrollment criteria had a primary colon cancer identified, and both died within 1 month after diagnosis without receiving therapy targeted at colon cancer. One patient without colon cancer had a perforation because of colonoscopy, which required surgery and colostomy. The cost of a strategy of routinely performing colonoscopy in patients referred with MCUP was $84 736 per colon primary identified.

CONCLUSIONS

Primary colon cancer was rarely identified at colonoscopy in patients with MCUP and no standard indications for diagnostic colonoscopy. Furthermore, the cost to diagnose one additional colon primary was very high. Those with colon cancer had advanced disease and were unable to benefit from targeted therapy. Routine colonoscopy for MCUP cannot be recommended at present.

Acute binge pattern cocaine administration induces region-specific effects in D1-r- and D2-r-expressing cells in eGFP transgenic mice

Cocaine addiction is driven by genetic, neurologic and environmental components. The D1-like (D1 and D5) and D2-like (D2, D3 and D4) families of dopamine receptors play an important role in modulating the effects of cocaine administration on drug-seeking behavior. The advent of bacterial artificial chromosome-eGFP (enhanced green fluorescent protein) transgenic mice that express eGFP driven by the endogenous D1-receptor (D1-r) or D2-receptor (D2-r) promoters provides a unique opportunity to distinguish between these subpopulations of cells. In an effort to identify cocaine-induced alterations in D1-r- versus D2-r-expressing cells during the initial stages of addiction, we examined cells that expressed D1-rs in Drd1-eGFP mice, or D2-rs in Drd2-eGFP mice, after an acute, 1-day binge pattern of cocaine administration. We used multiphoton confocal microscopy and Visiopharm© software, to conduct unbiased stereological counts of D1-r-labeled or D2-r-labeled cells in various striatal regions. Mice were sacrificed at 30 min and 24-h post cocaine or saline administration. Compared to saline controls, Drd1-eGFP mice that received cocaine had a higher count of D1-r-labeled cells in the dorsolateral (DL) striatum, at the 30-min and 24-h time-points. No changes in the nucleus accumbens (NAc) core or shell were observed in Drd1-eGFP mice. Drd2-eGFP mice that received cocaine had fewer D2-r-labeled cells in the DL striatum and NAc core compared to saline controls. This effect was observed at the 30-min time-point but not at 24h. Drd2-eGFP mice that received cocaine also had fewer numbers of D2-r-labeled cells in the NAc core compared to saline controls, but no significant differences in the number of D2-r-labeled cells in the NAc shell. These results suggest that acute binge pattern cocaine administration may induce region-specific alterations in D1-r or D2-receptor gene expression, and may help elucidate the differential role of dopamine receptors in the initial stages of the addiction cycle.

The effect of wearing loupes on upper extremity musculoskeletal disorders among dental hygienists

OBJECTIVES

It is well established that musculoskeletal disorders (MSD) are a significant occupational health issue for dentists and hygienists. Despite this, there has been little advancement in the application of ergonomic principles in the dental profession. While the use of loupes is often promoted as an ergonomic solution, there is little published research to robustly support this claim. The aim of the present study was to investigate the effect of the use of loupes on upper extremity MSD among dental hygienists.

METHODS

The study was conducted using an exploratory pretest and post-test design, comparing musculoskeletal measures in practising dental hygienists wearing loupes with final-year dental hygiene students who did not wear loupes. Pre- and post-test measures included valid self-reported and objective outcome measures and were measured at baseline and 6 months following the intervention. Statistical analysis was conducted as a series of mixed anovas with time and treatment as the independent variables.

RESULTS

The analysis revealed a significant interaction between time and treatment for the Disabilities of the Shoulder, Arm and Hand (DASH) scores (P < 0.04), indicating an improvement in symptoms for the treatment group but a reversed trend for the controls. There was also a significant mean increase in scapular position measures; however, this finding was evident in both groups, indicating that these were not a result of the intervention.

CONCLUSIONS

Overall, this study suggests that wearing loupes appears to have both positive and negative effects on upper extremity MSD among dental hygienists. Ongoing research is required to determine the long-term effects of loupes wear, over an extended period of time.

Conceptualizing functional traits and ecological characteristics of methane-oxidizing bacteria as life strategies

Methane-oxidizing bacteria (MOB) possess the ability to use methane for energy generation and growth, thereby, providing a key ecosystem service that is highly relevant to the regulation of the global climate. MOB subgroups have different responses to key environmental controls, reflecting on their functional traits. Their unique features (C1-metabolism, unique lipids and congruence between the 16S rRNA and pmoA gene phylogeny) have facilitated numerous environmental studies, which in combination with the availability of cultured representatives, yield the most comprehensive ecological picture of any known microbial functional guild. Here, we focus on the broad MOB subgroups (type I and type II MOB), and aim to conceptualize MOB functional traits and observational characteristics derived primarily from these environmental studies to be interpreted as microbial life strategies. We focus on the functional traits, and the conditions under which these traits will render different MOB subgroups a selective advantage. We hypothesize that type I and type II MOB generally have distinct life strategies, enabling them to predominate under different conditions and maintain functionality. The ecological characteristics implicated in their adopted life strategies are discussed, and incorporated into the Competitor-Stress tolerator-Ruderal functional classification framework as put forward for plant communities. In this context, type I MOB can broadly be classified as competitor-ruderal while type II MOB fit more within the stress tolerator categories. Finally, we provide an outlook on MOB applications by exemplifying two approaches where their inferred life strategies could be exploited thereby, putting MOB into the context of microbial resource management.

Regional mRNA expression of GABAergic receptor subunits in brains of C57BL/6J and 129P3/J mice: strain and heroin effects

C57BL/6J and 129 substrains of mice are known to differ in their basal levels of anxiety and behavioral response to drugs of abuse. We have previously shown strain differences in heroin-induced conditioned place preference (CPP) between C57BL/6J (C57) and 129P3/J (129) mice, and in the regional expression of several receptor and peptide mRNAs. In this study, we examined the contribution of the GABAergic system in the cortex, nucleus accumbens (NAc), caudate putamen (CPu) and the region containing the substantia nigra and ventral tegmental area (SN/VTA) to heroin reward by measuring mRNA levels of 7 of the most commonly expressed GABA-A receptor subunits, and both GABA-B receptor subunits, in these same mice following saline (control) or heroin administration in a CPP design. Using real-time PCR, we studied the effects of strain and heroin administration on GABA-A α1, α2, α3, β2, and γ2 subunits, which typically constitute synaptic GABA-A receptors, GABA-A α4 and δ subunits, which typically constitute extrasynaptic GABA-A receptors, and GABA-B R1 and R2 subunits. In saline-treated animals, we found an experiment-wise significant strain difference in GABA-Aα2 mRNA expression in the SN/VTA. Point-wise significant strain differences were also observed in GABA-Aα2, GABA-Aα3, and GABA-Aα4 mRNA expression in the NAc, as well as GABA-BR2 mRNA expression in the NAc and CPu, and GABA-BR1 mRNA expression in the cortex. For all differences, 129 mice had higher mRNA expression compared to C57 animals, with the exception of GABA-BR1 mRNA in the cortex where we observed lower levels in 129 mice. Therefore, it may be possible that known behavioral differences between these two strains are, in part, due to differences in their GABAergic systems. While we did not find heroin dose-related changes in mRNA expression levels in C57 mice, we did observe dose-related differences in 129 mice. These results may relate to our earlier behavioral finding that 129 mice are hyporesponsive to the rewarding effects of heroin.

Systematic review and pooled analysis assessing the association between elderly age and outcome following surgical resection of esophageal malignancy

The incidence of esophageal malignancy continues to increase worldwide. At the same time, average life expectancy levels continue to climb, ensuring that more patients will present in their 70s, 80s, and 90s. The aim of this pooled analysis is to compare short- and long-term outcomes for elderly and younger patients undergoing esophagectomy for malignancy. Studies comparing the outcomes of esophagectomy for malignancy in elderly and young cohorts of patients were included. The minimum threshold age used to define the elderly cohort was 70 years. Primary outcomes were in-hospital mortality, overall and cancer-related 5-year survival. Secondary outcomes were the length of hospital stay, the incidence of anastomotic leak, conduit ischemia, cardiac and pulmonary complications, and the use of neoadjuvant therapy. Twenty-five publications comprising 9531 and 2573 operations on younger and elderly cohorts of patients respectively were analyzed. Elderly patients were less likely to receive neoadjuvant therapy (14.6% vs. 29.47%; pooled odds ratio [POR]= 0.48; 95% confidence interval [C.I.]= 0.35-0.65; P < 0.05). Esophagectomy in elderly patients was associated with increased in-hospital mortality (7.83% vs. 4.21%; POR = 1.87; 95% C.I. = 1.54-2.26; P < 0.05), as well as increased pulmonary (21.77% vs. 19.49%) and cardiac (18.7% vs. 13.17%) complications. Subset analysis of studies using an age threshold of 80 years showed an even more significant association between in-hospital mortality and elderly age (pooled odds ratio = 3.19; 95% C.I. = 1.6-6.35; P < 0.05). There were no significant differences between the groups in length of hospital stay, incidence of anastomotic leak, or conduit ischemia. The elderly group showed reduced overall 5-year survival (21.23% vs. 29.01%; pooled odds ratio = 0.73; 95% C.I. = 0.62-0.87; P < 0.05) and reduced cancer-free 5-year survival (34.4% vs. 41.8%; POR = 0.75; 95% C.I. = 0.64-0.89; P < 0.05). Elderly patients are at increased risk of pulmonary and cardiac complications, and perioperative mortality following esophagectomy, and show reduced cancer-related 5-year survival compared with younger patients. These patients represent a high-risk cohort, who requires thorough assessment of medical comorbidity, targeted counseling, and optimized treatment pathways.

Providing predictive testing for Huntington disease via telehealth: results of a pilot study in British Columbia, Canada

Predictive testing (PT) for Huntington disease (HD) usually requires several in-person appointments which acts as a barrier to testing for those from remote regions. This pilot study reports the use of telehealth PT to examine whether such telehealth testing improves access to HD PT while maintaining quality of care and support. Individuals underwent PT via the telehealth protocol or standard in-person protocol and were asked to complete surveys regarding their experience. Results reveal no significant differences between the in-person-tested and telehealth-tested groups with respect to quality of care, information, counselling and support. The majority of participants in both groups stated that pre-test counselling had provided them with sufficient knowledge about the advantages and disadvantages of undergoing testing, the opportunity to ask questions, and the ability to make an informed decision. The majority of participants in both groups were satisfied by the manner in which results were delivered and stated they had received sufficient information regarding the implications of these results. This study reveals that telehealth PT improves access while maintaining quality of care and support.

Cocaine place conditioning increases pro-opiomelanocortin gene expression in rat hypothalamus

Recent research suggests an involvement of pro-opiomelanocortin (POMC) gene products in modulating cocaine reward and addiction-like behaviors in rodents. In this study, we investigated whether cocaine-induced conditioned place preference (CPP) alters POMC gene expression in the brain or pituitary of rats. Sprague-Dawley rats were conditioned with 4 injections of 0, 10 or 30 mg/kg cocaine (i.p.) over 8 days and tested 4 days after the last conditioning session. Another group received the same pattern of cocaine injections without conditioning. POMC mRNA levels in the hypothalamus (including arcuate nucleus), amygdala and anterior pituitary, as well as plasma ACTH and corticosterone levels were measured. Cocaine place conditioning at 10 and 30 mg/kg doses increased POMC mRNA levels in a dose-dependent manner in the hypothalamus, with no effect in the amygdala. Cocaine CPP had no effect on POMC mRNA levels in the anterior pituitary or on plasma ACTH or corticosterone levels. In rats that received cocaine at 30 mg/kg without conditioning, there was no such effect on hypothalamic POMC mRNA levels. Alteration of POMC gene expression in the hypothalamus is region-specific after cocaine place conditioning, and dose-dependent. The increased POMC gene expression in the hypothalamus suggests that it is involved in the reward/learning process of cocaine-induced conditioning.

Detection of bremsstrahlung radiation of 90Sr-90Y for emergency lung counting

This study explores the possibility of developing a field-deployable (90)Sr detector for rapid lung counting in emergency situations. The detection of beta-emitters (90)Sr and its daughter (90)Y inside the human lung via bremsstrahlung radiation was performed using a 3″ × 3″ NaI(Tl) crystal detector and a polyethylene-encapsulated source to emulate human lung tissue. The simulation results show that this method is a viable technique for detecting (90)Sr with a minimum detectable activity (MDA) of 1.07 × 10(4) Bq, using a realistic dual-shielded detector system in a 0.25-µGy h(-1) background field for a 100-s scan. The MDA is sufficiently sensitive to meet the requirement for emergency lung counting of Type S (90)Sr intake. The experimental data were verified using Monte Carlo calculations, including an estimate for internal bremsstrahlung, and an optimisation of the detector geometry was performed. Optimisations in background reduction techniques and in the electronic acquisition systems are suggested.