The Effect of Probiotic Bacteria on Composition and Metabolite Production of Faecal Microbiota Using In Vitro Batch Cultures

Probiotic supplements are increasingly being used to target the gut microbiome with a view to improving cognitive and psychological function via the gut-brain axis. One possible mechanism behind the effect of probiotics is through alterations to microbially-derived metabolites including short-chain fatty acids (SCFA) and neurotransmitters. However, research to date has largely been conducted in animal models or under conditions irrelevant to the human gastrointestinal tract (GIT). The aim of the current work was therefore to use anaerobic, pH controlled in vitro batch cultures to (a) assess the production of neuroactive metabolites in human faecal microbiota under conditions relevant to the human GIT, and (b) to explore how several pre-selected probiotic strains may affect bacterial composition and metabolite production. Enumeration of bacteria was assessed using fluorescence in situ hybridisation with flow cytometry, and concentrations of SCFAs and neurotransmitters were measured using gas chromatography and liquid chromatography mass spectroscopy, respectively. GABA, serotonin, tryptophan, and dopamine were successfully detected, suggesting some level of microbial derivation. The addition of Lactococcus lactis W58 and Lactobacillus rhamnosus W198 resulted in a significant increase in lactate after 8 h of fermentation, while no significant effect of probiotics on bacterial composition or neurotransmitter production was found.

Voriconazole-associated periostitis presenting as hypertrophic osteoarthropathy following lung transplantation report of two cases and review of the literature

BACKGROUND

Hypertrophic osteoarthropathy (HOA) is a syndrome characterized by abnormal proliferation of skin and osseous tissue frequently associated with underlying pulmonary disorders. Cardinal features include digital clubbing, periostitis and significant joint and bone pain. A number of recent reports have emerged of HOA and periostitis occurring in association with the antifungal agent voriconazole.

METHODS

We present two additional cases of voriconazole-induced HOA and periostitis in lung transplant recipients with a review the medical literature.

RESULTS

In both cases, symptoms were painful and severe enough to require opioid medication. Rapid improvement occurred within days of voriconazole cessation. A review of existing literature revealed an additional 17 cases of voriconazole-induced HOA and periostitis in lung transplant patients.

CONCLUSION

We highlight the importance of recognizing the association of voriconazole with painful HOA and periostitis in lung transplant patients receiving antifungal therapy. Management of this painful condition involves cessation of voriconazole therapy, which may necessitate alternative anti-fungal drug therapies as well as adjustment of immunosuppressive drug dosage since voriconazole is a strong drug-inducer.

Antioxidant activity, total phenolics and flavonoids contents: Should we ban in vitro screening methods?

As many studies are exploring the association between ingestion of bioactive compounds and decreased risk of non-communicable diseases, the scientific community continues to show considerable interest in these compounds. In addition, as many non-nutrients with putative health benefits are reducing agents, hydrogen donors, singlet oxygen quenchers or metal chelators, measurement of antioxidant activity using in vitro assays has become very popular over recent decades. Measuring concentrations of total phenolics, flavonoids, and other compound (sub)classes using UV/Vis spectrophotometry offers a rapid chemical index, but chromatographic techniques are necessary to establish structure-activity. For bioactive purposes, in vivo models are required or, at the very least, methods that employ distinct mechanisms of action (i.e., single electron transfer, transition metal chelating ability, and hydrogen atom transfer). In this regard, better understanding and application of in vitro screening methods should help design of future research studies on 'bioactive compounds'.

Profile measurements in the plasma edge of mega amp spherical tokamak using a ball pen probe

The ball pen probe (BPP) technique is used successfully to make profile measurements of plasma potential, electron temperature, and radial electric field on the Mega Amp Spherical Tokamak. The potential profile measured by the BPP is shown to significantly differ from the floating potential both in polarity and profile shape. By combining the BPP potential and the floating potential, the electron temperature can be measured, which is compared with the Thomson scattering (TS) diagnostic. Excellent agreement between the two diagnostics is obtained when secondary electron emission is accounted for in the floating potential. From the BPP profile, an estimate of the radial electric field is extracted which is shown to be of the order ∼1 kV/m and increases with plasma current. Corrections to the BPP measurement, constrained by the TS comparison, introduce uncertainty into the ER measurements. The uncertainty is most significant in the electric field well inside the separatrix. The electric field is used to estimate toroidal and poloidal rotation velocities from E × B motion. This paper further demonstrates the ability of the ball pen probe to make valuable and important measurements in the boundary plasma of a tokamak.

Divertor impurity injection using high voltage arcs for impurity transport studies on the Mega Amp Spherical Tokamak

The operation of next-generation fusion reactors will be significantly affected by impurity transport in the scrape-off layer (SOL). Current modelling efforts are restricted by a lack of detailed data on impurity transport in the SOL. In order to address this, a carbon injector has been designed and installed on the Mega Amp Spherical Tokamak (MAST). The injector creates short lived carbon plumes originating at the MAST divertor lasting less than 50 μs. High voltage capacitor banks are used to create a discharge across concentric carbon electrodes located in a probe mounted on the Divertor Science Facility in the MAST lower divertor. This results in a very short plume duration allowing observation of the evolution of the plume and precise localisation of the plume relative to the X-point on MAST. The emission from the carbon plume was imaged using fast visible cameras filtered in order to isolate the carbon II and carbon III emission lines centered around 514 nm and 465 nm.

The transduction of rat submandibular glands by an adenoviral vector carrying the human growth hormone gene is associated with limited and reversible changes at the infusion site

Adenoviral vectors have been shown to efficiently deliver exogenous genes to salivary glands and have therefore been investigated as tools for the treatment of human disease. The purpose of this study was to evaluate the response of F344 rats to intraductal infusion of the right submandibular salivary gland with an adenoviral vector encoding the gene for human growth hormone (AdCMVhGH). Co-administration of hydroxychloroquine (HCQ) was used to redirect the secretion of human growth hormone (hGH) from saliva into serum. This paper documents the findings of the pathology evaluation of this National Toxicology Program study. The right submandibular salivary gland (infusion site) was the primary target organ, with microscopic lesions characteristic of a mild to moderate insult observed at 3 days post infusion in vector exposed animals. These lesions were characterized by variable degrees of acute glandular inflammation, degeneration and necrosis, with more severe lesions in the higher dose groups. Rats at 28 days post infusion had milder inflammation, degeneration and necrosis compared to day 3 rats, with variable degrees of regeneration. In conclusion, the effects on the salivary glands are reversible as indicated by the milder inflammation and degeneration in the day 28 rats concomitant with mild to moderate regeneration. Therefore, the vector appears relatively innocuous with limited tissue toxicity. [The supplemental data referenced in this paper is not printed in this issue of Toxicologic Pathology. It is available as a downloadable file in the online edition of Toxicologic Pathology, 34(4). In order to access the full article online, you must have either an individual subscription or a member subscription accessed through www.toxpath.org.].

Toxicity and biodistribution of a first-generation recombinant adenoviral vector, in the presence of hydroxychloroquine, following retroductal delivery to a single rat submandibular gland

OBJECTIVE

We examined the toxicity and biodistribution associated with a single administration of a first-generation, serotype 5, adenoviral vector encoding human growth hormone (hGH; AdCMVhGH) to a single rat submandibular gland in the presence of hydroxychloroquine (HCQ). Previously, we showed that hGH is primarily secreted into saliva (approximately ninefold serum level) when expressed as a transgene in salivary glands (e.g. Baum et al, 1999), but administration of HCQ substantially increases the hGH levels secreted into the bloodstream (Hoque et al, 2001). A potential application of this observation is for patients with adult hGH deficiency.

METHODS

Six groups of male and female adult rats (n = 12 each) were studied, with zero to 1.5 x 10(11) particles of AdCMVhGH, +/-HCQ, administered retroductally. Multiple clinical and pathological parameters, as well as vector tissue distribution, were assessed.

RESULTS

All animals survived until the scheduled day of sacrifice, and essentially no untoward events were observed clinically or at gross necropsy. We observed no vector-related effects on clinical hematology evaluations and a single, transient significant change on clinical chemistry evaluations (increased serum globulin levels). Three days after AdCMVhGH administration, the vector distributed to all tissues analyzed with the exception of gonads and heart. By day 29, most organs, other than the targeted and contralateral submandibular glands, were negative for the presence of vector. On day 3, none of the animals tested positive for the presence of replication competent adenovirus in either their blood or saliva.

CONCLUSION

Salivary gland delivery of AdCMVhGH +/-HCQ appears associated with limited toxicity in rats.

Characterization of the cytoplasmic filament protein gene (cfpA) of Treponema pallidum subsp. pallidum

Treponema pallidum and other members of the genera Treponema, Spirochaeta, and Leptonema contain multiple cytoplasmic filaments that run the length of the organism just underneath the cytoplasmic membrane. These cytoplasmic filaments have a ribbon-like profile and consist of a major cytoplasmic filament protein subunit (CfpA, formerly called TpN83) with a relative molecular weight of approximately 80,000. Degenerate DNA primers based on N-terminal and CNBr cleavage fragment amino acid sequences of T. pallidum subsp. pallidum (Nichols) CfpA were utilized to amplify a fragment of the encoding gene (cfpA). A 6.8-kb EcoRI fragment containing all but the 5' end of cfpA was identified by hybridization with the resulting PCR product and cloned into Lambda ZAP II. The 5' region was obtained by inverse PCR, and the complete gene sequence was determined. The cfpA sequence contained a 2,034-nucleotide coding region, a putative promoter with consensus sequences (5'-TTTACA-3' for -35 and 5'-TACAAT-3' for -10) similar to the sigma70 recognition sequence of Escherichia coli and other organisms, and a putative ribosome-binding site (5'-AGGAG-3'). The deduced amino acid sequence of CfpA indicated a protein of 678 residues with a calculated molecular mass of 78.5 kDa and an estimated pI of 6.15. No significant homology to known proteins or structural motifs was found among known prokaryotic or eukaryotic sequences. Expression of a LacZ-CfpA fusion protein in E. coli was detrimental to survival and growth of the host strain and resulted in the formation of short, irregular filaments suggestive of partial self-assembly of CfpA. The cytoplasmic filaments of T. pallidum and other spirochetes appear to represent a unique form of prokaryotic intracytoplasmic inclusions.

Alcoholic seizures: intellectual and neuropsychological sequelae

Alcoholics who experienced withdrawal seizures performed comparably to those who did not suffer seizures on intellectual and neuropsychological tests. Both groups, however, exhibited a number of impairments. The hypothesis that the withdrawal seizure is indicative of alcoholism severity and can serve as a marker for extent of neurological disturbance was not supported.