Survival patterns of Streptococcus suis serotypes 1 and 14 in porcine blood indicate cross-reactive bactericidal antibodies in naturally infected pigs.

Streptococcus suis serotype (cps) 1 and cps14 have been detected in association with severe diseases such as meningitis and polyarthritis in pigs. Though these two cps are very similar, only cps14 is an important zoonotic agent in Asia and only cps1 is described to be associated with diseases in suckling piglets rather than weaning piglets. The main objective of this study was to assess restriction of survival of cps14 and cps1 in porcine blood by IgG and IgM putatively cross-reacting with these two cps. Furthermore, we differentiate recent European cps1/14 strains by agglutination, cpsK sequencing, MLST and virulence-associated gene profiling. Our data confirmed cps1 of clonal complex 1 as an important pathotype causing polyarthritis in suckling piglets in Europe. The experimental design included also bactericidal assays with blood samples drawn at different ages of piglets naturally infected with different S. suis cps types including cps1 but not cps14. We report survival of a cps1 and a cps14 strain (both of sequence type 1) in blood of suckling piglets with high levels of maternal IgG binding to the bacterial surface. In contrast, killing of cps1 and cps14 was recorded in older piglets due to an increase of IgM as demonstrated by specific cleavage of IgM. Heterologous absorption of antibodies with cps1 or cps14 is sufficient to significantly increase the survival of the other cps. In conclusion, IgM elicited by natural S. suis infection is crucial for killing of S. suis cps1 and cps14 in older weaning piglets and has most likely the potential to cross-react between cps1 and cps14.

GC/MS analysis and potential cytotoxic activity of Calyptranthes grandifolia (O. Berg), Calyptranthes tricona (D. Legrand) and Myrciaria plinioides (D. Legrand) essential oil in RAW264.7 and CHO-K1 cells.

The search for new bioactive substances derived from natural products is daily growing. Among biologically active products used in therapeutic approaches, essential oils are described with wide range of therapeutic and pharmacological potential. Plants from Myrtaceae family have the presence of essential oils in its composition. Calyptranthes grandifolia, Calyptranthes tricona and Myrciaria plinioides species belong to this family and are used by the local population. However, there are no reports in the literature describing relevant characteristics about the potential and possible activities of these species. The aim of this study was to identify the main compounds, evaluate the antioxidant potential and investigate, in RAW264.7 and CHO-K1 cells, the cytotoxic activity of the essential oils from the leaves of C. grandifolia, C. tricona and M. plinioides plants, in order to ensure their use. The compounds were identified by GC-MS, antioxidant activity was determined by DPPH method and cytotoxicity was assessed by the Alamar Blue method, at 48 and 72h. The main compounds found in the essential oils were sesquiterpenes. None of the essential oils have antioxidant potential. In cytotoxicity assays, the essential oils from the plants in analysis showed moderate activity in the proposed conditions. The alterations observed between the data provided by the essential oils in question, between different cell lines, may be associated with their composition, suggesting action of minor compounds. These results may suggest that the essential oils from C. grandifolia, C. tricona and M. plinioides have considerable potential to be explored. Future studies will be conducted to obtain more information about the action pathway and potential of the identified compounds.

Low-level laser therapy improves peri-implant bone formation: resonance frequency, electron microscopy, and stereology findings in a rabbit model.

Previous studies have reported positive effects of low-level laser therapy (LLLT) on bone healing. This study evaluated the effects of LLLT on peri-implant healing in vivo. Thirty-two rabbits had their mandibular left incisors removed, followed by immediate insertion of a dental implant into the fresh socket. Animals were assigned randomly to four groups: control (non-irradiated) or LLLT at three different doses per session: 5J/cm(2), 10J/cm(2), and 20J/cm(2). A GaAlAs laser (830nm, 50mW) was applied every 48h for 13 days, starting immediately after surgery. The implant stability quotient (ISQ) was measured using resonance frequency analysis upon implant insertion and immediately after death, 30 days after the last application. Tissues were prepared for scanning electron microscopy (SEM) and stereology. Variables measured were bone-implant contact (BIC) and bone neoformation within implant threads at three different sites. The results showed better ISQ for the 20J/cm(2) group (P=0.003). BIC values were significantly higher (P<0.05) in the 20J/cm(2) group, on both SEM and stereology. Bone area values were better in the 10J/cm(2) (P=0.036) and 20J/cm(2) (P=0.016) groups compared to the control group. Under these conditions, LLLT enhanced peri-implant bone repair, improving stability, BIC, and bone neoformation. The findings support and suggest parameters for the design of clinical trials using LLLT after implant placement.

Assessment of the systemic effects of low-level laser therapy (LLLT) on thyroid hormone function in a rabbit model.

The aim of this study was to assess the effects of low-level laser therapy (LLLT) applied to a dental extraction socket on thyroid gland function in a rabbit model, based on serum triiodothyronine and thyroxine levels. Sixteen male New Zealand rabbits were randomly distributed into two groups: a control group (non-irradiated animals) and an experimental group (irradiated animals: one irradiation point in the extraction socket of the lower incisor). Animals in the experimental group were irradiated with an aluminium gallium arsenide diode laser (AlGaAs; wavelength 830 nm, 40 mW, CW laser), for 13 days, every 48 h, at a dose of 6 J/cm(2) per session, resulting in a total dose of 42 J/cm(2). Serum triiodothyronine and thyroxine levels were measured in both groups before extraction and on the last day of observation (day 15). There were no statistically significant differences between the groups in pre- and post-irradiation triiodothyronine and thyroxine values. With the irradiation protocol used in this study, LLLT did not affect thyroid function in rabbits as assessed by circulating serum triiodothyronine and thyroxine levels.

Lidocaine/tetracaine patch (Rapydan) for topical anaesthesia before arterial access: a double-blind, randomized trial.

BACKGROUND: Arterial catheterization is painful and is associated with patient stress and anxiety. Analgesia is usually provided by subcutaneous injection of local anaesthetic. An alternative is topical anaesthesia, such as Rapydan which is a novel topical anaesthetic patch containing 70 mg each of lidocaine and tetracaine. We therefore tested the hypothesis that Rapydan patch analgesia is non-inferior to subcutaneous local anaesthetic. METHODS: Ninety patients undergoing elective major cardiac surgery were included in this prospective, double-blind clinical trial. Patients were randomly assigned to receive either a lidocaine/tetracaine patch, followed by subcutaneous injection 0.5 ml of normal saline solution, or placebo patch with subsequent subcutaneous injection of 0.5 ml of lidocaine 1%. Pain during arterial catheterization using 100-mm-long visual analogue scale (VAS) was the primary outcome. Other outcomes were pain during anaesthetic/saline injection and plasma tetracaine concentrations. RESULTS: VAS pain scores during arterial puncture were comparable in both groups and Rapydan was non-inferior to subcutaneous lidocaine. Pain scores at the time of subcutaneous injection were significantly lower (better) in patients assigned to the lidocaine/tetracaine patch than to lidocaine (P=0.001). Plasma tetracaine concentrations never exceeded the detection limit of 25 ng ml(-1) at any time in any patient. CONCLUSIONS: Both the lidocaine/tetracaine patch and subcutaneous injection of lidocaine provided comparable pain control during arterial catheter insertion. Subcutaneous lidocaine caused discomfort during injection, whereas the lidocaine/tetracaine patch required placement 20 min before the procedure. Given adequate time, the patch provided better overall analgesia by obviating the need for subcutaneous infiltration.