Frontal organs in the Acoelomorpha (Turbellaria): Ultrastructure and phylogenetic significance

Using characters discernible through electron microscopy, we redefine the organ traditionally identified as the frontal organ in acoelomorph turbellarians as being a collection of two to several large mucus-secreting glands whose necks emerge together through a frontal pore at the exact apical pole of the body, i.e. at the point where the pattern of epidermal ciliary rootlets converges. Representatives that we have studied of each of the acoel families Paratomellidae, Diopisthoporidae, Solenofilomorphidae, Convolutidae, Otocelidae, and Mecynostomidae, as well as a representative of the Nemertodermatida, have such glands. Up to five additional types of glands that open anteriorly outside of the frontal pore, some of which are indistinguishable from glands of the general body wall, could be seen in the nemertodermatid, in Hesiolicium inops (Paratomellidae), and in representatives of the latter four acoel families. In Paratomella, three different types of glands open in diffuse fashion in a frontal glandular complex reminiscent of that in the Macrostomida.Sensory elements near the frontal pore appear to be independent of the gland necks, and so the organ cannot be considered a sensory organ.The frontal organ, as described above, appears very likely to be homologous within the Acoelomorpha, and represents another strong (although unrooted) autapomorphy for this line of turbellarian evolution.     

Autoradiographic confirmation of mucus-mediated absorption in the halfbeak Hyporhamphus regularis ardelio (Whitley, 1931)

In an investigation of the relationship between acidic glycoproteins released in the pharynx and oesophagus of Hyporhamphus regularis ardelio and 'juice' released from Zostera capricorni by pharyngeal milling, autoradiographs of thin sections of guts of fish fed C¹⁴ labelled seagrass leaves revealed high emission densities in the acidic glycoprotein sheath surrounding the ingesta. This indicates that 'juice' liberated from seagrass is taken up by the mucus.     

Human Saliva-Derived Exosomes: Comparing Methods of Isolation

ExoQuick-TC^TM (EQ), a chemical-based agent designed to precipitate exosomes, was calibrated for use on saliva collected from healthy individuals. The morphological and molecular features of the precipitations were compared with those obtained using the classical, physical-based method of ultracentrifugation (UC). Electron microscopy and immunoelectron microscopy with anti-CD63 showed vesicular nanoparticles surrounded by bi-layered membrane, compatible with exosomes in EQ, similar to that observed with UC. Atomic force microscopy highlighted larger, irregularly shaped/aggregated EQ nanoparticles that contrasted with the single, round-shaped UC nanoparticles. ELISA (performed on 0.5 ml of saliva) revealed a tendency for a higher expression of the specific exosomal markers (CD63, CD9, CD81) in EQ than in UC (p>0.05). ELISA for epithelial growth factor receptor, a non-exosomal-related marker, showed a significantly higher concentration in EQ than in UC (p=0.04). Western blotting of equal total-protein concentrations revealed bands of CD63, CD9 and CD81 in both types of preparations, although they were less pronounced in EQ compared with UC. This may be related to a higher fraction of non-exosomal proteins in EQ. In conclusion, EQ is suitable and efficient for precipitation of salivary exosomes from small volumes of saliva; however, EQ tends to be associated with considerably more biological impurities (non-exosomal-related proteins/microvesicles) as compared with UC.     

Unique Occurrence of the 1CF11 Carbohydrate Epitope in Primate Saliva

We examined a large number of individual human and animal saliva samples for the reactivity with 1CF11, a mouse monoclonal antibody previously produced for the characterization of human milk mucin and apparently recognizing a certain carbohydrate antigenic structure shared by various human glycoproteins in secretions. The results obtained here confirm the unique occurrence of 1CF11 epitope in each and every saliva sample from humans and Old world monkeys as well, though a vast variety was observed among individual saliva samples in the immunological reactivity with 1CF11.     

A PCR-DGGE method for detection and identification of Campylobacter, Helicobacter, Arcobacter and related Epsilobacteria and its application to saliva samples from humans and domestic pets

AIMS: To develop a PCR-denaturing gradient gel electrophoresis (PCR-DGGE) method for the detection and identification of Campylobacter, Helicobacter and Arcobacter species (Epsilobacteria) in clinical samples and evaluate its efficacy on saliva samples from humans and domestic pets. METHODS AND RESULTS: A semi-nested PCR was developed to allow sensitive detection of all Epsilobacteria, with species separation undertaken by DGGE. A database was constructed in BioNumerics using 145 strains covering 51 Campylobacter, Arcobacter and Helicobacter taxa; Nineteen distinct DGGE profile-groups were distinguished. This approach detected Epsilobacteria in all saliva samples collected from humans, cats and dogs, and identified Campylobacter concisus and/or Campylobacter gracilis in the human samples. The pet animal samples were taken from individuals with oral/dental diseases; PCR-DGGE identified up to four different species in each sample. The most common species detected included Wolinella succinogenes, Arcobacter butzleri and two hitherto uncultured campylobacters. The enteropathogen Campylobacter lari was also found. CONCLUSIONS: PCR combined with DGGE is a useful tool for direct detection and preliminary identification of Epsilobacteria in the oral cavity of humans and small animals. SIGNIFICANCE AND IMPACT OF THE STUDY: The PCR-DGGE method should allow determination of the true prevalence and diversity of Epsilobacteria in clinical and other samples. Contact with the oral cavity of domestic pets may represent a route of transmission for epsilobacterial enteric diseases.     

Determination of H2O2-dependent generation of singlet oxygen from human saliva with a novel chemiluminescence probe

Singlet oxygen (¹O₂) has been shown to play an important role in salivary defense system, but its generation process and level from human saliva remain uncertain due to the lack of a reliable detection method. We have previously reported 4,4′(5′)-bis[2-(9-anthryloxy)ethylthio]tetrathiafulvalene (BAET) as a novel chemiluminescence probe for ¹O₂. In this work, the probe is successfully used to characterize H₂O₂-dependent generation of ¹O₂ from saliva in real time. However, the yield of ¹O₂ is found to be very low, for example, being about 0.13 nmol from 200 μL saliva in the presence of 1 mM of hydrogen peroxide over a 5-s reaction period. The result is also compared with that obtained with another ¹O₂ probe 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2-a]pyrazin-3-one (CLA), demonstrating that, besides ¹O₂, the other reactive oxygen species such as hydroxyl radical may also be involved in the reaction of saliva with H₂O₂. Furthermore, the present study shows that the selectivity of BAET for ¹O₂ is much higher than that of CLA and thus BAET is highly suited for the detection of ¹O₂ in the presence of other reactive oxygen species in biological systems.     

Origin, structure, and biological activities of peroxidases in human saliva

Human whole saliva contains two peroxidases, salivary peroxidase (hSPO) and myeloperoxidase (hMPO), which are part of the innate host defence in oral cavity. Both hSPO as well as human milk lactoperoxidase (hLPO) are coded by the same gene, but to what extent the different producing glands, salivary and mammary glands, affect the final conformation of the enzymes is not known. In human saliva the major function of hSPO and hMPO is to catalyze the oxidation of thiocyanate (SCN(-)) in the presence of hydrogen peroxide (H(2)O(2)) resulting in end products of wide antimicrobial potential. In addition cytotoxic H(2)O(2) is degraded. Similar peroxidation reactions inactivate some mutagenic and carcinogenic compounds, which suggests another protective mechanism of peroxidases in human saliva. Although being target of an active antimicrobial research, the structure-function relationships of hSPO are poorly known. However, recently published method for recombinant hSPO production offers new tools for those investigations.     

Myzus persicae (green peach aphid) salivary components induce defence responses in Arabidopsis thaliana

Myzus persicae (green peach aphid) feeding on Arabidopsis thaliana induces a defence response, quantified as reduced aphid progeny production, in infested leaves but not in other parts of the plant. Similarly, infiltration of aphid saliva into Arabidopsis leaves causes only a local increase in aphid resistance. Further characterization of the defence-eliciting salivary components indicates that Arabidopsis recognizes a proteinaceous elicitor with a size between 3 and 10 kD. Genetic analysis using well-characterized Arabidopsis mutants shows that saliva-induced resistance against M. persicae is independent of the known defence signalling pathways involving salicylic acid, jasmonate and ethylene. Among 78 Arabidopsis genes that were induced by aphid saliva infiltration, 52 had been identified previously as aphid-induced, but few are responsive to the well-known plant defence signalling molecules salicylic acid and jasmonate. Quantitative PCR analyses confirm expression of saliva-induced genes. In particular, expression of a set of O -methyltransferases, which may be involved in the synthesis of aphid-repellent glucosinolates, was significantly up-regulated by both M. persicae feeding and treatment with aphid saliva. However, this did not correlate with increased production of 4-methoxyindol-3-ylmethylglucosinolate, suggesting that aphid salivary components trigger an Arabidopsis defence response that is independent of this aphid-deterrent glucosinolate.     

Noninvasive recovery and detection of possum Trichosurus vulpecula DNA from bitten bait interference devices (WaxTags)

The brushtail possum is a major agricultural and ecological pest in New Zealand. A novel noninvasive DNA sampling tool for detecting its presence (WaxTags, or WT) was tested. DNA was recovered from saliva left on WT, and two lengths (407 bp and 648 bp) of the cytochrome c oxidase I (COI) barcoding region were amplified by polymerase chain reaction (PCR). PCR products were considered (+) when a DNA band was clearly visible by electrophoresis. Different factors that might affect PCR (+) were investigated with captive possums: (i) both extraction protocols of the QIAGEN DNeasy Blood and Tissue Kit, (ii) effect of an overnight or longer delay of up to 3 weeks before DNA extraction on both COI amplicons, and (iii) effect of the individual, order and magnitude of the bite. Extraction protocols were not significantly different. The effect of the overnight delay was not significant, and amplification of the short amplicon was significantly higher (100%) than for the long fragment (48%). After a two or 3‐week delay, the short amplicon had 94% and 56% PCR (+), success rates, respectively. Individual, order and magnitude of a bite had no significant effect. The delay trial was repeated with WT from the wild, for which PCR (+) rate of the short amplicon was 63%, regardless of freshness. Four microsatellites were amplified from captive WT samples. We conclude that DNA from saliva traces can be recovered from WT, a potential new tool for noninvasive monitoring of possums and other wildlife.     

异麦芽低聚糖对D-半乳糖致衰老大鼠肠道菌群、血清IgG和肠黏膜sIgA的影响

目的探讨异麦芽低聚糖对D-半乳糖致衰老大鼠肠黏膜功能的影响。方法Wistar大鼠随机分为3组：（1）青年对照组,（2）衰老对照组,（3）衰老观察组（衰老＋异麦芽低聚糖）。采用D-半乳糖造成衰老模型后,应用异麦芽低聚糖灌胃,检测各组肠道菌群、血清IgG和肠黏膜sIgA。结果D-半乳糖致衰老大鼠肠道菌群失调;灌胃异麦芽低聚糖后,衰老大鼠肠道双歧杆菌增加（P〈0．05）,肠杆菌和肠球菌数量减少（P〈0．05）;血清IgG、肠黏膜sIgA含量增加（P〈0．05）。结论异麦芽低聚糖可改善衰老机体肠黏膜功能。