Kaon Photoproduction and the Λ Decay Parameter α_{-}.

The weak decay parameter α_{-} of the Λ is an important quantity for the extraction of polarization observables in various experiments. Moreover, in combination with α_{+} from Λ[over ¯] decay it provides a measure for matter-antimatter asymmetry. The weak decay parameter also affects the decay parameters of the Ξ and Ω baryons and, in general, any quantity in which the polarization of the Λ is relevant. The recently reported value by the BESIII Collaboration of 0.750(9)(4) is significantly larger than the previous PDG value of 0.642(13) that had been accepted and used for over 40 years. In this work we make an independent estimate of α_{-}, using an extensive set of polarization data measured in kaon photoproduction in the baryon resonance region and constraints set by spin algebra. The obtained value is 0.721(6)(5). The result is corroborated by multiple statistical tests as well as a modern phenomenological model, showing that our new value yields the best description of the data in question. Our analysis supports the new BESIII finding that α_{-} is significantly larger than the previous PDG value. Any experimental quantity relying on the value of α_{-} should therefore be reconsidered.

Strong Evidence for Nucleon Resonances near 1900 MeV.

Data on the reaction γp→K^{+}Λ from the CLAS experiments are used to derive the leading multipoles, E_{0+}, M_{1-}, E_{1+}, and M_{1+}, from the production threshold to 2180 MeV in 24 slices of the invariant mass. The four multipoles are determined without any constraints. The multipoles are fitted using a multichannel L+P model that allows us to search for singularities and to extract the positions of poles on the complex energy plane in an almost model-independent method. The multipoles are also used as additional constraints in an energy-dependent analysis of a large body of pion and photoinduced reactions within the Bonn-Gatchina partial wave analysis. The study confirms the existence of poles due to nucleon resonances with spin parity J^{P}=1/2^{-}, 1/2^{+}, and 3/2^{+} in the region at about 1.9 GeV.

Precision Measurement of the p(e,e

New results are reported from a measurement of π^{0} electroproduction near threshold using the p(e,e^{'}p)π^{0} reaction. The experiment was designed to determine precisely the energy dependence of s- and p-wave electromagnetic multipoles as a stringent test of the predictions of chiral perturbation theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the ϕ_{π}^{*} and θ_{π}^{*} angles in the pπ^{0} center of mass was obtained for invariant energies above threshold from 0.5 up to 15 MeV. The 4-momentum transfer Q^{2} coverage ranges from 0.05 to 0.155 (GeV/c)^{2} in fine steps. A simple phenomenological analysis of our data shows strong disagreement with p-wave predictions from ChPT for Q^{2}>0.07 (GeV/c)^{2}, while the s-wave predictions are in reasonable agreement.

Intra-amniotic pharmacological blockade of inflammatory signalling pathways in an ovine chorioamnionitis model.

Intrauterine inflammation (IUI) associated with infection is the major cause of preterm birth (PTB) at <32 weeks' gestation and accounts for ∼40% of all spontaneous PTBs. Pharmacological strategies to prevent PTB and improve fetal outcomes will likely require both antimicrobial and anti-inflammatory therapies. Here we investigated the effects of two cytokine-suppressive anti-inflammatory drugs (CSAIDs), compounds that specifically target inflammatory signalling pathways, in an ovine model of lipopolysaccharide (LPS)-induced chorioamnionitis. Chronically catheterized ewes at 116 days gestation (n = 7/group) received an intra-amniotic (IA) bolus of LPS (10 mg) plus vehicle or CSAIDS: TPCA-1 (1.2 mg/kg fetal weight) or 5z-7-oxozeaenol (OxZnl; 0.4 mg/kg fetal weight); controls received vehicle (dimethylsulphoxide). Amniotic fluid (AF), fetal and maternal blood samples were taken 0, 2, 6, 12, 24 and 48 h later; tissues were taken at autopsy (48 h). Administration of TPCA-1 or OxZnl abrogated the stimulatory effects of LPS (P < 0.01 versus vehicle control) on production of PGE2 in AF, with lesser (non-significant) effects on IL-6 production. Fetal membrane polymorphonuclear cell infiltration score was significantly higher in LPS versus vehicle control animals (P < 0.01), and this difference was absent with TPCA-1 and OxZnl treatment. LPS-induced systemic fetal inflammation was highly variable, with no significant effects of CSAIDs observed. Lung inflammation was evident with LPS exposure, but unaffected by CSAID treatment. We have shown in a large animal model that IA administration of a single dose of CSAIDs can suppress LPS-induced IA inflammatory responses, while fetal effects were minimal. Further development and investigation of these compounds in infectious models is warranted.

Relative sensitivity of an amphipod Hyalella azteca, a midge Chironomus dilutus, and a unionid mussel Lampsilis siliquoidea to a toxic sediment.

The objective of the present study was to evaluate the relative sensitivity of test organisms in exposures to dilutions of a highly toxic sediment contaminated with metals and organic compounds. One dilution series was prepared using control sand (low total organic carbon [TOC; <0.1%, low binding capacity for contaminants]) and a second dilution series was prepared using control sediment from West Bearskin Lake, Minnesota, USA (high TOC [∼10% TOC, higher binding capacity for contaminants]). Test organisms included an amphipod (Hyalella azteca; 10-d and 28-d exposures), a midge (Chironomus dilutus; 20-d and 48-d exposures started with <1-h-old larvae, and 13-d and 48-d exposures started with 7-d-old larvae), and a unionid mussel (Lampsilis siliquoidea; 28-d exposures). Relative species sensitivity depended on the toxicity endpoint and the diluent. All 3 species were more sensitive in sand dilutions than in West Bearskin Lake sediment dilutions. The <1-h-old C. dilutus were more sensitive than 7-d-old C. dilutus, but replicate variability was high in exposures started with the younger midge larvae. Larval biomass and adult emergence endpoints of C. dilutus exhibited a similar sensitivity. Survival, weight, and biomass of H. azteca were more sensitive endpoints in 28-d exposures than in 10-d exposures. Weight and biomass of L. siliquoidea were sensitive endpoints in both sand and West Bearskin Lake sediment dilutions. Metals, ammonia, oil, and other organic contaminants may have contributed to the observed toxicity.

A mobile phone enabled health promotion program for middle-aged males.

The prevalence of chronic diseases among middle aged males outweigh their female counterparts in developed countries. To prevent this, delivery of health promotion programs targeting lifestyle modifications of physical activity and nutrition in middle-aged males has been essential, but often difficult. ManUp health promotion program was a recent initiative that uses current advances in information and communication technology (ICT) to reach the middle-aged males. One of the key components of the ICT approach was the development of smartphone application to enable middle-aged men to uptake the program with their own mobile phone. The smart phone application was aimed at providing varied level of challenges towards physical activity and healthy eating behavior, with interactive and motivational feedback SMS messages. The ManUp program was recently implemented and trialed in a randomized control trial in Gladstone and Rockhampton, Queens. This paper describes the components of the smart phone application integrated within the ManUp health promotion program.

The role of surface wettability and surface charge of electrosprayed nanoapatites on the behaviour of osteoblasts.

A new deposition method is presented, based on electrospraying, that can build bioceramic structures with desirable surface properties. This technology allows nanoapatite crystals, including hydroxyapatite (nHA), carbonate-substituted HA (nCHA) and silicon-substituted HA (nSiHA), to be electrosprayed on glass substrates. Human osteoblast cells cultured on nSiHA showed enhanced cell attachment, proliferation and protein expression, namely alkaline phosphatase, type 1 collagen and osteocalcin, as compared to nHA and nCHA. The modification of nanoapatite by the addition of silicon into the HA lattice structure renders the electrosprayed surface more hydrophilic and electronegatively charged.

Induction of necrosis and cell cycle arrest in murine cancer cell lines by Melaleuca alternifolia (tea tree) oil and terpinen-4-ol.

PURPOSE: To examine the in vitro anticancer activity of Melaleuca alternifolia (tea tree) oil (TTO), and its major active terpene component, terpinen-4-ol, against two aggressive murine tumour cell lines, AE17 mesothelioma and B16 melanoma. METHODS: Effects of TTO and terpinen-4-ol on the cellular viability of two tumour cell lines and fibroblast cells were assessed by MTT assay. Induction of apoptotic and necrotic cell death was visualised by fluorescent microscopy and quantified by flow cytometry. Tumour cell ultrastructural changes were examined by transmission electron microscopy and changes in cell cycle distribution were assessed by flow cytometry, with changes in cellular morphology monitored by video time lapse microscopy. RESULTS: TTO and terpinen-4-ol significantly inhibited the growth of two murine tumour cell lines in a dose- and time-dependent manner. Interestingly, cytotoxic doses of TTO and terpinen-4-ol were significantly less efficacious against non-tumour fibroblast cells. TTO and terpinen-4-ol induced necrotic cell death coupled with low level apoptotic cell death in both tumour cell lines. This primary necrosis was clarified by video time lapse microscopy and also by transmission electron microscopy which revealed ultrastructural features including cell and organelle swelling following treatment with TTO. In addition, both TTO and terpinen-4-ol induced their inhibitory effect by eliciting G1 cell cycle arrest. CONCLUSION: TTO and terpinen-4-ol had significant anti-proliferative activity against two tumour cell lines. Moreover, the identification of primary necrotic cell death and cell cycle arrest of the aggressive tumour cells highlights the potential anticancer activity of TTO and terpinen-4-ol.

The effects of silicate ions on human osteoblast adhesion, proliferation, and differentiation.

Silicon has been shown to have important effects on skeletal development and repair, and soluble silicate ions have been found to stimulate the expression of type-I collagen in osteoblast-like cell cultures. Furthermore, silicon has been incorporated into the hydroxyapatite lattice and enhanced metabolic activity of human osteosarcoma cells was observed when cells were cultured on this material. In vivo assessments have demonstrated enhanced bioactivity of silicon-substituted hydroxyapatite (Si-HA) over pure HA. However, detailed mechanisms for the stimulative effects of Si-HA have not been described. In this study, we found that silicon substitution into hydroxyapatite affects the adhesion of human osteoblast-like cells (HOBs) in culture, with 0.8 wt % silicon substitution being optimal. In addition, metabolic activity and proliferation of HOBs were increased by supplementation of the growth medium with 30 microM silicon. It was determined that this response may depend on the proportion of cells at different stages of differentiation within the cultures.

Bayesian analysis of pentaquark signals from CLAS data.

We examine the results of two measurements by the CLAS collaboration, one of which claimed evidence for a Theta(+) pentaquark, while the other found no such evidence. The unique feature of these two experiments was that they were performed with the same experimental setup. Using a Bayesian analysis, we find that the results of the two experiments are in fact compatible with each other, but that the first measurement did not contain sufficient information to determine unambiguously the existence of a Theta(+). Further, we suggest a means by which the existence of a new candidate particle can be tested in a rigorous manner.

Influence of nanohydroxyapatite patterns deposited by electrohydrodynamic spraying on osteoblast response.

Electrohydrodynamic spraying has been used to produce patterns of line width up to 100 microm in size on glass discs, using nanohydroxyapatite (nHA). A human osteoblast (HOB)-like cell model was then used to study the interaction between the HOB cells and nHA patterns in vitro. Growth of the cells was significantly increased (p < 0.05) on the nHA surfaces. In addition, HOBs attached and spread well, secreting extracellular matrix. It was found that a confluent, aligned cell layer was achieved on nHA patterns by day 9. Immunofluorescent staining indicated that these cells showed elongated nuclei, enhanced adhesion (vinculin adhesion plaques) and a well-aligned cytoskeleton (actin stress fibres). This work suggests that this type of spraying may provide a route for the production of nanoscale features on implants for biomedical applications.

Phenotypically plastic responses of green frog embryos to conflicting predation risk.

Predators have been shown to alter the timing of switch points between life history stages, but few studies have addressed switch point plasticity in prey exposed simultaneously to conflicting predation pressure. We tested hatching responses of green frog (Rana clamitans) embryos subject to perceived predation risk from chemical cues released by two stage-specific predators, predicting that these predators would elicit: (1) directional hatching responses when presented independently, and (2) intermediate phenotypic responses when presented simultaneously. R. clamitans embryos in outdoor exclosures were exposed to cues from an egg predator (freshwater leeches; Nephelopsis obscura), a larval predator (dragonfly nymphs, Aeschna canadensis), and both predators in a 2 x 2 factorial experiment, and changes in hatchling size, hatchling developmental stage, and hatching time were compared to those for control embryos. Leeches alone induced embryos to hatch at a smaller size and an earlier developmental stage than controls, while dragonfly nymphs elicited a delay in egg hatching time that was associated with larger size and later developmental stage at hatching. Embryos failed to respond to simultaneous exposure to both predators, implying that responses to each occurred concurrently and were therefore dampened. Our results indicate that prey under threat from conflicting predators may manifest intermediate defensive phenotypes. Such intermediate responses may result in elevated rates of prey mortality with possible consequences at the population level.

Osteoclast formation and bone resorption are inhibited by megakaryocytes.

It has been previously reported that addition of megakaryocytes (MKs) to osteoblasts in vitro results in increased osteoblastic collagen and osteoprotegerin (OPG) production, suggesting a role for MKs in bone formation. To further investigate this role, we have studied the effects of MKs on osteoclast formation and activity. Human osteoclasts were generated from CD14 monocytes isolated from peripheral blood and cultured in the presence of M-CSF and sRANKL on dentine and calcium phosphate substrates. MKs were generated from CD34+ cells isolated from either human peripheral blood or cord blood and cultured in liquid medium for 6 days, after which time maturing MKs (CD61-positive cells) were isolated and added to monocyte cultures. After 6 and 9 days of culture, the number of osteoclasts identified morphologically and by TRAP staining was counted. Cells were removed and the area of resorption was identified by von Kossa staining and quantitatively assessed by image analysis. The addition of MKs to osteoclast cultures at day 0 inhibited the number of osteoclasts formed 1.9-fold (p>0.003), whereas addition at 3 days had no effect on osteoclast number. The presence of MKs inhibited resorption 8.7-fold when co-cultured with osteoclasts from day 0 (p>0.004), but only by 3.1-fold when co-cultured from day 3 (p>0.01). In dose-response experiments, it was found that 1-10% of MKs added to monocyte cultures elicited the greatest inhibition of resorption. Similar osteoclast cultures were treated with CD61-negative cells (non-MKs) to confirm that the inhibition of osteoclast formation and activity was specifically due to MKs. Experiments with a cell-impermeable membrane indicated that both cell to cell contact and release of soluble factor(s) were involved in mediating these effects. These results show that MKs inhibit osteoclast formation and activity. The most pronounced effects were seen when MKs and osteoclasts were co-cultured from day 0, suggesting that MKs act primarily on osteoclast precursors.

Endometrial adenocarcinoma following insertion of the levonorgestrel-releasing intrauterine system (mirena) in a 36-year-old woman.

The levonorgestrel-releasing intrauterine system (LNG-IUS), commonly referred to as mirena, is an effective form of contraception, which is widely used as an intrauterine device. It has a 32-mm long-shaped plastic frame that holds a reservoir (on the vertical stem) of 52 mg of levonorgestrel mixed with polydimethylsiloxane to allow a steady release of 20 mug of levonorgestrel per day within the endometrial cavity through a rate-limiting surface membrane. Apart from contraceptive purpose, it is also now commonly used in the management of heavy menstrual blood loss. This study included a 36-year old woman who developed endometrial cancer following the insertion of the LNG-IUS. Her main presentation was irregular vaginal bleeding, which is a common finding in women using this form of contraception. Although we would advice caution in investigating such women, the LNG-IUS remains a relatively safe method of contraception.

Mesovarian hemangioma presenting as massive ascites, pelvic mass, and elevated CA125.

We present the case of a 48-year-old woman with pelvic mass, ascites, and an elevated CA125 mimicking advanced-stage ovarian cancer. She underwent laparotomy, drainage of ascites, total abdominal hysterectomy, bilateral salpingo-oophorectomy, and infracolic omentectomy. Histology confirmed this to be mesovarian hemangioma, a benign condition.

Should women with postcoital bleeding be referred for colposcopy?

This study was to determine the risk of finding significant cervical pathological abnormality in women referred to the colposcopy clinic primarily because of postcoital bleeding. We evaluated the cervical smear history of such women and correlated this with any colposcopic or pathological abnormality. There were 142 women seen over a period of 12 months. The age range of the study population was 16 - 61 years (mean age of 34.1 years). There was no case of lower genital tract invasive neoplasia. Out of the 142 cases, 56 women (39.4%) had normal findings at colposcopy and 44 (31%) were secondary to cervical ectopy. A total of 27 (19%) had cervical intraepithelial neoplasia (CIN) out of which there were 15 (10.6%) cases of high-grade disease (CIN II and CIN III); and, 20 (74%) out of the 27 women with CIN had a recently negative cervical smear (within the previous 36 months). Seven women (4.9%) had benign cervical polyps that were removed during colposcopy. The frequency of finding invasive lower genital tract neoplasia in women with postcoital bleeding is low. However, a good proportion of them would have a diagnosis of cervical intraepithelial neoplasia even with a recently negative cervical smear. Therefore, postcoital bleeding should remain an indication for referral to the colposcopy clinic for a detailed evaluation of the lower genital tract.

Aggressive angiomyxoma of the perineum.

We report the case of perineal aggressive angiomyxoma in a 46-year-old woman presenting as left perineal swelling associated with superficial dyspareunia. Initial clinical examination revealed a 4- to 5-cm cystic mass in the posterior aspect of the left labia majora, not thought to be typical of a Bartholin cyst. A magnetic resonance imaging (MRI) scan revealed a well-defined 2- x 1.5- x 2-cm area posterolateral to the lower vagina on the left but anterolateral to the anal canal extending into the left ischiorectal fossa, with no obvious involvement of the anal sphincter complex. Excision biopsy was performed via an incision in the left labia majus under general anesthesia. Histologic findings were consistent with aggressive angiomyxoma of the vulva. This was confirmed by immunohistochemistry showing spindle cells positive for vimentin with strong nuclear staining for estrogen and progestogen receptors. Postoperative management following discussion at the multidisciplinary gynecological oncology meeting was to perform a repeat MRI scan 6 weeks postoperatively, and treatment with raloxifene was commenced for its antiestrogenic property.

Rupture of the flexor digitorum profundus tendon to the small finger within the carpal tunnel.

We report three patients who sustained a rupture of the flexor digitorum profundus tendon to the small finger within the carpal tunnel. There was a common mechanism of injury, each rupture occurred during resisted flexion of the digit with the metacarpophalangeal joint in extension. All the patients were male, one patient had an asymptomatic undiagnosed fracture of the hook of hamate, one patient had radiological evidence of piso-triquetral osteoarthritis. In each case, an attrition rupture was confirmed at surgery.

A vascularised bone graft from the medial femoral condyle for recurrent failed arthrodesis of the distal interphalangeal joint.

A vascularised bone graft from the medial femoral condyle was used to correct a recurrent failed arthrodesis of the index finger distal interphalangeal joint. The flap was based upon the articular branch of the descending genicular artery. Union was confirmed 3 months after surgery.

Megakaryocytes modulate osteoblast synthesis of type-l collagen, osteoprotegerin, and RANKL.

We have previously reported evidence that megakaryocytes may play a role in bone remodeling, possibly by interactions with cells at the bone surface. To investigate the direct effects of megakaryocytes on osteoblasts, maturing megakaryocytes (CD61 positive cells) were isolated and added to cultures of human osteoblasts. Osteoblasts alone and osteoblasts treated with CD61-negative (non-megakaryocytic) cells were used as control cultures. After 48 h in culture, megakaryocytes were removed and osteoblasts immunolocalized for type-1 collagen, osteoprotegerin (OPG), and RANKL expression. Similar cultures were used for RNA extraction with mRNA for Col 1A1, OPG, and RANKL in osteoblasts measured quantitatively by RT-PCR. Osteoblasts cultured alone showed high levels of expression of collagen with 74% (+/-7) of cells staining positively. When cultured with megakaryocytes, the number of positively staining cells remained similar but the intensity of expression was increased 1.54-fold (P < 0.02). OPG was expressed by 32% (+/-6.3) of osteoblasts increasing to 51% (+/-5.5) when cultured in the presence of megakaryocytes (P < 0.01) with a 1.63-fold increase in intensity of expression (P < 0.01). In contrast, osteoblasts cultured with megakaryocytes showed suppression of RANKL expression; 35.6% (+/-5.8) of osteoblasts cultured alone stained positively decreasing to 24.3% (+/-5.3) with a 1.6-fold diminished intensity of expression (P < 0.02). Osteoblasts co-cultured with CD61-negative cells showed no differences in collagen, OPG, or RANKL expression levels compared to osteoblasts cultured alone. mRNA data supported these findings with a 3.1-fold increase in Col 1A1 expression in megakaryocyte-treated cultures compared to controls (P < 0.02). Low-level OPG mRNA expression increased 8.14-fold in osteoblasts cultured in the presence of megakaryocytes (P < 0.01), while RANKL expression was suppressed 3.3-fold (P < 0.02). These results demonstrate that in vitro, megakaryocytes have direct effects on osteoblastic production of factors affecting both bone formation and resorption. These data provide further evidence that megakaryocytes may play an important role in bone remodeling.