Acquisition of pneumococci specific effector and regulatory Cd4+ T cells localising within human upper respiratory-tract mucosal lymphoid tissue

The upper respiratory tract mucosa is the location for commensal Streptococcus (S.) pneumoniae colonization and therefore represents a major site of contact between host and bacteria. The CD4(+) T cell response to pneumococcus is increasingly recognised as an important mediator of immunity that protects against invasive disease, with data suggesting a critical role for Th17 cells in mucosal clearance. By assessing CD4 T cell proliferative responses we demonstrate age-related sequestration of Th1 and Th17 CD4(+) T cells reactive to pneumococcal protein antigens within mucosal lymphoid tissue. CD25(hi) T cell depletion and utilisation of pneumococcal specific MHCII tetramers revealed the presence of antigen specific Tregs that utilised CTLA-4 and PDL-1 surface molecules to suppress these responses. The balance between mucosal effector and regulatory CD4(+) T cell immunity is likely to be critical to pneumococcal commensalism and the prevention of unwanted pathology associated with carriage. However, if dysregulated, such responses may render the host more susceptible to invasive pneumococcal infection and adversely affect the successful implementation of both polysaccharide-conjugate and novel protein-based pneumococcal vaccines

Bioinformatic and statistical analysis of the optic nerve head in a primate model of ocular hypertension

<p>Abstract</p> <p>Background</p> <p>The nonhuman primate model of glaucomatous optic neuropathy most faithfully reproduces the human disease. We used high-density oligonucleotide arrays to investigate whole genome transcriptional changes occurring at the optic nerve head during primate experimental glaucoma.</p> <p>Results</p> <p>Laser scarification of the trabecular meshwork of cynomolgus macaques produced elevated intraocular pressure that was monitored over time and led to varying degrees of damage in different samples. The macaques were examined clinically before enucleation and the myelinated optic nerves were processed post-mortem to determine the degree of neuronal loss. Global gene expression was examined in dissected optic nerve heads with Affymetrix GeneChip microarrays. We validated a subset of differentially expressed genes using qRT-PCR, immunohistochemistry, and immuno-enriched astrocytes from healthy and glaucomatous human donors. These genes have previously defined roles in axonal outgrowth, immune response, cell motility, neuroprotection, and extracellular matrix remodeling.</p> <p>Conclusion</p> <p>Our findings show that glaucoma is associated with increased expression of genes that mediate axonal outgrowth, immune response, cell motility, neuroprotection, and ECM remodeling. These studies also reveal that, as glaucoma progresses, retinal ganglion cell axons may make a regenerative attempt to restore lost nerve cell contact.</p

Impact of hiatal hernia on histological pattern of non-erosive reflux disease

BACKGROUND: Hiatus hernia (HH) has major pathophysiological effects favoring gastroesophageal reflux and hence contributing to esophageal mucosa injury, especially in patients with severe gastroesophageal disease. However, prospective studies investigating the impact of HH on the esophageal mucosa in non-erosive reflux disease (NERD) are lacking. This study evaluated the association between the presence of (HH) and the histological findings in symptomatic patients with NERD. METHODS: Fifty consecutive patients with gastroesophageal reflux disease (GERD) were enrolled. After conventional endoscopy, Lugol solution was applied and biopsy specimens were obtained. Histological parameters including basal zone hyperplasia, papillary length and cellular infiltration were evaluated. The chi-square test with Yates' correlation was used for comparing discrete parameters between groups. However, Fisher's exact probability test was used where the expected frequencies were lower than 5. Wilcoxon's test for unpaired samples was preferred in cases of semi-quantitative parameters. RESULTS: The presence of HH along with more severe findings (0.01 <P < 0.05) was confirmed in 18 patients. NERD was observed in 29 (58%) patients. Basal zone hyperplasia and loss of glycogen accompanied HH in all cases, and the correlation was significant in NERD (P < 0.001). The remaining histological patterns were similar between erosive reflux disease and NERD in the presence of HH. CONCLUSION: The presence of HH is correlated with more severe endoscopy findings, and predisposes for severe histological abnormality in cases of NERD

Single-cell resolution imaging of retinal ganglion cell apoptosis in vivo using a cell-penetrating caspase-activatable peptide probe

Peptide probes for imaging retinal ganglion cell (RGC) apoptosis consist of a cell-penetrating peptide targeting moiety and a fluorophore-quencher pair flanking an effector caspase consensus sequence. Using ex vivo fluorescence imaging, we previously validated the capacity of these probes to identify apoptotic RGCs in cell culture and in an in vivo rat model of N-methyl- D-aspartate (NMDA)-induced neurotoxicity. Herein, using TcapQ488, a new probe designed and synthesized for compatibility with clinically-relevant imaging instruments, and real time imaging of a live rat RGC degeneration model, we fully characterized time- and dose-dependent probe activation, signal-to-noise ratios, and probe safety profiles in vivo. Adult rats received intravitreal injections of four NMDA concentrations followed by varying TcapQ488 doses. Fluorescence fundus imaging was performed sequentially in vivo using a confocal scanning laser ophthalmoscope and individual RGCs displaying activated probe were counted and analyzed. Rats also underwent electroretinography following intravitreal injection of probe. In vivo fluorescence fundus imaging revealed distinct single-cell probe activation as an indicator of RGC apoptosis induced by intravitreal NMDA injection that corresponded to the identical cells observed in retinal flat mounts of the same eye. Peak activation of probe in vivo was detected 12 hours post probe injection. Detectable fluorescent RGCs increased with increasing NMDA concentration; sensitivity of detection generally increased with increasing TcapQ488 dose until saturating at 0.387 nmol. Electroretinography following intravitreal injections of TcapQ488 showed no significant difference compared with control injections. We optimized the signal-to-noise ratio of a caspase-activatable cell penetrating peptide probe for quantitative non-invasive detection of RGC apoptosis in vivo. Full characterization of probe performance in this setting creates an important in vivo imaging standard for functional evaluation of future probe analogues and provides a basis for extending this strategy into glaucoma-specific animal models

Missing upper incisors: a retrospective study of orthodontic space closure versus implant

Background: The aim of this retrospective study was to compare the esthetic, periodontal, and functional outcomes of orthodontic space closure versus implant substitution in patients with missing maxillary incisors 5 years after completion of treatment. Methods: The study group consisted of ten patients treated with orthodontic space closure (six males, four females, mean age 19 ± 2.1 years at the completion of treatment) and ten patients treated with implant insertion (five males, five females, mean age 20 ± 1.4 years at the time of implant insertion). Tooth mobility, plaque index, probing depth, infraocclusion, open gingival embrasure (black triangle), and temporomandibular joint function were recorded at the 5.6 years follow-up. Self-perceived dental esthetic appearance was also evaluated through a visual analog scale (VAS) questionnaire. T-test was used to evaluate the data. Results: All patients were equally satisfied with the appearance of their teeth 5.6 ± 0.4 years after the completion of treatment. No statistically significant differences were found in relation to the VAS scores of the subjects (P < 0.857). No significant differences were found in tooth mobility, plaque index (P < 0.632), and the prevalence of signs and symptoms of temporomandibular disorders. However, significant infraocclusion was noticed in all implant patients (P < 0.001). Probing depth was also significantly higher in implant patients (P < 0.001). Conclusions: Orthodontic space closure and implant of missing maxillary incisors produced similar, well-accepted esthetic results. None of the treatments impaired temporomandibular joint function. Nevertheless, infraocclusion was evident in implant patients. Space closure patients also showed better periodontal health in comparison with implant patients

Feasibility and safety of setting up a donor breastmilk bank in a neonatal prem unit in a resource limited setting: An observational, longitudinal cohort study

<p>Abstract</p> <p>Background</p> <p>The beneficial effects of human milk on decreasing rates of paediatric infections such as necrotizing enterocolitis (NEC) and sepsis have been clearly demonstrated. Donor breastmilk has been encouraged as the milk of choice when a mother's own breastmilk is not available. The objectives of this study were to assess feasibility of providing donor breastmilk to infants in a resource limited Neonatal Prem Unit (NPU). In addition we sought to determine whether donor breastmilk could be safely pasteurized and administered to infants without any adverse events.</p> <p>Methods</p> <p>Low birth weight infants < 1800 g and under 32 weeks gestational age were followed up in the NPU over a 3 week period; feeding data and morbidity data was collected in order to determine if there were any adverse events associated with donor breastmilk. Samples of pasteurized breastmilk were cultured to check for any bacterial contamination.</p> <p>Results</p> <p>191 infants met the inclusion criteria of whom 96 received their mother's own breastmilk. Of the 95 infants who were potentially eligible to receive donor milk, only 40 did in fact receive donor milk. There was no evidence of bacterial contamination in the samples analyzed, and no evidence of adverse events from feeding with donor breastmilk.</p> <p>Conclusion</p> <p>It is feasible to supply donor breastmilk to infants in an NPU in a resource limited setting, however staff needs to be sensitized to the importance of donor breastmilk to improve uptake rates. Secondly we showed that it is possible to supply donor breastmilk according to established guidelines with no adverse events therefore making it possible to prevent NEC and other side effects often associated with formula feeding of premature infants.</p

The addition of locust bean gum but not water delayed the gastric emptying rate of a nutrient semisolid meal in healthy subjects

BACKGROUND: Most of the previous studies regarding the effects of gel-forming fibres have considered the gastric emptying of liquid or solid meals after the addition of pectin or guar gum. The influence of locust bean gum, on gastric emptying of nutrient semisolid meals in humans has been less well studied, despite its common occurrence in foods. Using a standardised ultrasound method, this study was aimed at investigating if the gastric emptying in healthy subjects could be influenced by adding locust been gum, a widely used thickening agent, or water directly into a nutrient semisolid test meal. METHODS: The viscosity of a basic test meal (300 g rice pudding, 330 kcal) was increased by adding Nestargel (6 g, 2.4 kcal), containing viscous dietary fibres (96.5%) provided as seed flour of locust bean gum, and decreased by adding 100 ml of water. Gastric emptying of these three test meals were evaluated in fifteen healthy non-smoking volunteers, using ultrasound measurements of the gastric antral area to estimate the gastric emptying rate (GER). RESULTS: The median value of GER with the basic test meal (rice pudding) was estimated at 63 %, (range 47 to 84 %), (the first quartile = 61 %, the third quartile = 69 %). Increasing the viscosity of the rice pudding by adding Nestargel, resulted in significantly lower gastric emptying rates (p < 0.01), median GER 54 %, (range 7 to 71 %), (the first quartile = 48 %, the third quartile = 60 %). When the viscosity of the rice pudding was decreased (basic test meal added with water), the difference in median GER 65 %, (range 38 to 79 %), (the first quartile = 56 %, the third quartile = 71 %) was not significantly different (p = 0.28) compared to the GER of the basic test meal. CONCLUSIONS: We conclude that the addition of locust bean gum to a nutrient semisolid meal has a major impact on gastric emptying by delaying the emptying rate, but that the addition of water to this test meal has no influence on gastric emptying in healthy subjects

A candidate probiotic with unfavourable effects in subjects with irritable bowel syndrome: a randomised controlled trial

<p>Abstract</p> <p>Background</p> <p>Some probiotics have shown efficacy for patients with irritable bowel syndrome (IBS). <it>Lactobacillus (L.) plantarum </it>MF1298 was found to have the best <it>in vitro </it>probiotic properties of 22 strains of lactobacilli. The aim of this study was to investigate the symptomatic effect of <it>L. plantarum </it>MF1298 in subjects with IBS. Primary outcome was treatment preference and secondary outcomes were number of weeks with satisfactory relief of symptoms and IBS sum score.</p> <p>Methods</p> <p>The design was a randomised double blind placebo-controlled crossover trial. 16 subjects with IBS underwent two three-week periods of daily intake of one capsule of 10¹⁰CFU <it>L. plantarum </it>MF 1298 or placebo separated by a four-week washout period.</p> <p>Results</p> <p>Thirteen participants (81%; 95% CI 57% to 93%; <it>P </it>= 0.012) preferred placebo to <it>L. plantarum </it>MF1298 treatment. The mean (SD) number of weeks with satisfactory relief of symptoms in the periods with <it>L. plantarum </it>MF1298 and placebo were 0.50 (0.89) and 1.44 (1.26), respectively (<it>P </it>= 0.006). IBS sum score was 6.44 (1.81) in the period with <it>L. plantarum </it>MF1298 treatment compared with 5.35 (1.77) in the period with placebo (<it>P </it>= 0.010). With a clinically significant difference in the IBS sum score of 2 in disfavour of active treatment, the number needed to harm was 3.7, 95% CI 2.3 to 10.9.</p> <p>Conclusions</p> <p>This trial shows for the first time an unfavourable effect on symptoms in subjects with IBS after intake of a potential probiotic.</p> <p>The trial registration number</p> <p>Clinical trials NCT00355810.</p

Therapeutic Benefit of Radial Optic Neurotomy in a Rat Model of Glaucoma

Radial optic neurotomy (RON) has been proposed as a surgical treatment to alleviate the neurovascular compression and to improve the venous outflow in patients with central retinal vein occlusion. Glaucoma is characterized by specific visual field defects due to the loss of retinal ganglion cells and damage to the optic nerve head (ONH). One of the clinical hallmarks of glaucomatous neuropathy is the excavation of the ONH. The aim of this work was to analyze the effect of RON in an experimental model of glaucoma in rats induced by intracameral injections of chondroitin sulfate (CS). For this purpose, Wistar rats were bilaterally injected with vehicle or CS in the eye anterior chamber, once a week, for 10 weeks. At 3 or 6 weeks of a treatment with vehicle or CS, RON was performed by a single incision in the edge of the neuro-retinal ring at the nasal hemisphere of the optic disk in one eye, while the contralateral eye was submitted to a sham procedure. Electroretinograms (ERGs) were registered under scotopic conditions and visual evoked potentials (VEPs) were registered with skull-implanted electrodes. Retinal and optic nerve morphology was examined by optical microscopy. RON did not affect the ocular hypertension induced by CS. In eyes injected with CS, a significant decrease of retinal (ERG a- and b-wave amplitude) and visual pathway (VEP N2-P2 component amplitude) function was observed, whereas RON reduced these functional alterations in hypertensive eyes. Moreover, a significant loss of cells in the ganglion cell layer, and Thy-1-, NeuN- and Brn3a- positive cells was observed in eyes injected with CS, whereas RON significantly preserved these parameters. In addition, RON preserved the optic nerve structure in eyes with chronic ocular hypertension. These results indicate that RON reduces functional and histological alterations induced by experimental chronic ocular hypertension

A new method for determining physician decision thresholds using empiric, uncertain recommendations

<p>Abstract</p> <p>Background</p> <p>The concept of risk thresholds has been studied in medical decision making for over 30 years. During that time, physicians have been shown to be poor at estimating the probabilities required to use this method. To better assess physician risk thresholds and to more closely model medical decision making, we set out to design and test a method that derives thresholds from actual physician treatment recommendations. Such an approach would avoid the need to ask physicians for estimates of patient risk when trying to determine individual thresholds for treatment. Assessments of physician decision making are increasingly relevant as new data are generated from clinical research. For example, recommendations made in the setting of ocular hypertension are of interest as a large clinical trial has identified new risk factors that should be considered by physicians. Precisely how physicians use this new information when making treatment recommendations has not yet been determined.</p> <p>Results</p> <p>We derived a new method for estimating treatment thresholds using ordinal logistic regression and tested it by asking ophthalmologists to review cases of ocular hypertension before expressing how likely they would be to recommend treatment. Fifty-eight physicians were recruited from the American Glaucoma Society. Demographic information was collected from the participating physicians and the treatment threshold for each physician was estimated. The method was validated by showing that while treatment thresholds varied over a wide range, the most common values were consistent with the 10-15% 5-year risk of glaucoma suggested by expert opinion and decision analysis.</p> <p>Conclusions</p> <p>This method has advantages over prior means of assessing treatment thresholds. It does not require physicians to explicitly estimate patient risk and it allows for uncertainty in the recommendations. These advantages will make it possible to use this method when assessing interventions intended to alter clinical decision making.</p