Clinical Outcomes of Sidewall/Parametrial Simultaneous Integrated Boost for Patients with Cervical Cancer

PURPOSE/OBJECTIVE(S)

In the treatment of cervical cancer, simultaneous integrated boost (SIB) is a common technique to deliver increased dose to gross disease in the para-aortic and pelvic nodal basins. However, SIB to the pelvic sidewall/parametria is not well characterized in the literature. We hypothesized that sidewall simultaneous integrated boost (SIB) in the treatment of cervical cancer is associated with acceptable levels of toxicity.

MATERIALS/METHODS

From 1/2009-12/2018, patients who received concurrent chemoradiation with external beam radiation therapy, utilizing a sidewall SIB technique, followed by low dose rate or high dose rate brachytherapy treatment were retrospectively identified. Sidewall SIB was defined as treatment at 2.1-2.4Gy/fraction to the parametria-usually performed for those with disease width >4cm at time of treatment start. Acute and late toxicity grading was defined by the Common Terminology Criteria for Adverse Events Version 5.0. Overall survival (OS), local control, progression-free survival (PFS), and toxicity were analyzed utilizing the Kaplan Meier method. Potential associations between cumulative D2cc for bladder and rectum and time to toxicity were investigated using Cox regression.

RESULTS

Fifty-six patients with IB2-IVB cervical cancer treated with sidewall SIB were identified, with a median follow up of 7.0 years (95% CI: 6.3, 8.3). Patients had a median age of 43 years (range: 26-68); 2 (3.6%) had FIGO stage I, 7 (12.5%) stage II, 46 (82.1%) stage III, and 1 (1.8%) stage IV disease. A majority had squamous cell histology (83.9%). Nearly all patients (96.4%) received concurrent cisplatin chemotherapy. Rates of acute grade ≥3 gastrointestinal (GI), genitourinary (GU), vaginal, and hematologic toxicity were 1.8%, 1.8%, 0%, and 15.9% respectively. Rates of late grade ≥3 GI, GU, and vaginal toxicity were 11.3%, 18.5%, and 11.1% respectively. OS and local control rates at five years were 0.61 (95% CI: 0.46, 0.73) and 0.95 (95% CI: 0.84, 0.98), respectively. Median PFS was 7.8 years (95% CI: 2.4, Not reached). Cumulative D2cc bladder was not significantly associated with time to Grade 2 or greater (HR 1.04, p = 0.33) or Grade 3 or greater (HR 1.02; p = 0.64) GU toxicity. Cumulative D2cc rectum was not significantly associated with time to Grade 2 or greater (HR 1.06, p = 0.06) or Grade 3 or greater (HR 1.08; p = 0.09) GI toxicity.

CONCLUSION

Sidewall SIB is a feasible technique for dose escalation in the treatment of cervical cancer with rates of acute and late toxicity consistent with other reports.

Hyperbaric Oxygen Therapy Attenuates the Whole Brain Radiotherapy-Induced Progressive Cognitive Dysfunction via Promoting Hippocampal Neurogenesis in Rats

PURPOSE/OBJECTIVE(S)

Radiation therapy is a widely used brain tumor treatment; however, it can cause significant effects on the central nervous system, including neurogenesis impairment, microglia activation, and oxidative stress, leading to brain injury. Hyperbaric oxygen therapy (HBOT) has been shown to benefit various neurological conditions, but its effect on radiation-induced brain injury damage remains limited. This study aims to investigate the impact of HBOT on radiation-induced neurogenesis impairment, microglia activation, and lipid peroxidation levels, and also aim to assess the therapeutic potential of HBOT on preventing irradiation-induced brain injury.

MATERIALS/METHODS

This study used a rat model that delivered different doses (2, 4, 10 Gy) of whole-brain radiation therapy (WBRT). The rats were divided into two groups: one received HBOT, and the other acted as the control (normal baric air, NBA) group. HBOT was performed on day 8 of post-radiation once per day for five consecutive days a week for four weeks. The rats were subjected to different irradiation dosages as described, followed by administration of 5-chloro-2'-deoxyuridine (CldU) immediately at day 0 or day 0 to day 7 and 5-iodo-2'-deoxyuridine (IdU) at day 2 or day 14 to day 28 following WBRT to detect serially replicating cells. Then the rats underwent behavioral tests to assess their cognitive and motor function every week. Brain tissues were collected and analyzed to evaluate neurogenesis, microglia activation, lipid peroxidation, and antioxidant levels using immunofluorescence stain and ELISA on days 7 and 28 of post-WBRT.

RESULTS

The radial maze was used to measure spatial learning and memory in rats. Compared with the 0 Gy-WBRT group, the 2 Gy-, 4 Gy-, and 10 Gy-WBRT groups of rats displayed a significant increase in latency. Seven days of post-WBRT, the newly proliferation cells (IdU positive) and serial replicating cells (CldU+IdU double positive) in the hippocampal dentate gyrus were significantly increased but were coupled with apoptosis. The alterations in the cellular composition of the dentate gyrus area were observed on days 7 and 28 post-WBRT, including increased newborn neuroblast and neuron, but half underwent apoptosis, which is associated with microglia phagocytosis and results in cognitive impairment. The lipid peroxidation was significantly increased on day 28 of post-WBRT. HBOT improves cognitive function by attenuating the WBRT-induced lipid oxidation, newly-formed cell apoptosis, and microglia phagocytosis.

CONCLUSION

Our present study suggests that HBOT may have a potential role in mitigating the effects of irradiation-induced brain injury by maintaining neurogenesis and reducing lipid peroxidation.

Pretreatment Clinical Parameters Associated with Intracranial Progression Burden Following an Initial Stereotactic Radiosurgery Course in a Multi-Institutional Brain Metastases Cohort

PURPOSE/OBJECTIVE(S)

While brain metastasis (BM) velocity is a valuable prognostic metric at time of intracranial progression (ICP), pre-SRS risk factors for post-SRS high-burden intracranial progression (ICP) remain poorly characterized. We hypothesized that pre-SRS clinical parameters are associated with subsequent high-burden (ICP), defined as either ≥5 (ICP5) or new/progressive ≥11 BMs (ICP11).

MATERIALS/METHODS

All patients completing an initial SRS course for BMs at two institutions from 1/2015-12/2020 were retrospectively identified. Patients with prior whole brain radiation therapy (WBRT) and/or BM resection were eligible. Demographic and clinical parameters were collected. ICP was defined as any radiographic concern for distant and/or in-field progression per multidisciplinary consensus. Overall survival (OS) and freedom from ICP were estimated via the Kaplan Meier method. Cox models assessed association between parameters and freedom from ICP5 and ICP11.

RESULTS

We identified 1383 patients completed SRS, with a median follow up of 8.7 months. Patients were 54.8% female, 45.6% with KPS ≥90, and a median of 63.4 years old. Primary tumor types included non-small cell lung (48.7%), breast (14.7%), and melanoma (8.5%). 46.9% had oligometastatic disease (≤5 metastatic foci: including BMs) at SRS, and 53.4% underwent SRS for >1 BM. 10.3% of patients had undergone prior WBRT and 26.1% surgical resection. 555 patients (40.1%) experienced ICP following SRS, of whom 72.6% had 1-4, 11.5% had 5-10, and 15.9% had ≥11 new/progressive BMs. Among patients with ICP, 6-month freedom from ICP was 35.5% (95% CI: 31.1-40.5%) for those with 1-4 BMs at time of ICP, 29.7% (95% CI: 20.4-43.3%) for 5-10 BMs, and 20.5% (95% CI: 13.5-30.1%) for ≥11 BMs (p = 0.016). Respective 12-month OS rates were 56.8% (95% CI: 52.1-61.9%), 46.0% (95% CI: 35.1-60.1%), and 38.7% (95% CI: 29.4-50.9%; p<0.001). Neurologic symptoms at time of ICP were observed in 21.1% of patients with 1-4 BMs, 28.1% with 5-10 BMs, and 50.0% with new/progressive ≥11 BMs (p<0.001). On multivariable analysis, superior freedom from high-burden ICP was associated with the following pre-SRS parameters: oligometastatic burden (ICP5: HR 0.68, 95% CI: 0.47-0.99; ICP11: 0.59; 95% CI: 0.36-0.97), no prior immunotherapy (ICP11: HR 0.57, 95% CI: 0.34-0.57), and a single BM at time of initial SRS (1 vs 2 BM, ICP 5: HR 0.51, 95% CI: 0.31-0.82; ICP11: HR 0.45, 95% CI: 0.24-0.84), while primary tumor type was not associated with ICP5 or ICP11.

CONCLUSION

Pre-SRS parameters including polymetastatic burden, prior receipt of immunotherapy, and >1 BM were associated with post-SRS high-burden ICP. High burden ICP developed earlier following SRS completion and was associated with higher rates of neurologic decline and inferior OS.

ChatGPT is an Unreliable Tool for Reviewing Radiation Oncology Literature

PURPOSE/OBJECTIVE(S)

To assess whether ChatGPT, a popular deep learning text generation tool, can serve as a resource for in-training and practicing clinicians by accurately identifying and summarizing studies related to radiation oncology.

MATERIALS/METHODS

Three question templates (Q1-Q3, shown in Table 1) were applied to eight cancer types to compile 24 questions posed to ChatGPT. Cancer types were designated as either common (breast, non-small cell lung, prostate, p16 positive oropharyngeal, and rectal) or uncommon (hypopharyngeal, medulloblastoma, and vulvar). ChatGPT's responses to each question were then reviewed to quantify the number of studies referenced in the response, the percentage of studies listed that were real studies, and the percentage of studies listed that were correctly summarized. Outcomes were compared between cancer types (common vs uncommon) and question types using Wilcoxon rank sum tests. As a secondary analysis, we assessed internal consistency of ChatGPT's responses by querying ChatGPT with three identical iterations of Q1-Q3 for breast cancer and comparing its responses between iterations.

RESULTS

Across all 24 of ChatGPT's responses, there were 78 studies referenced, of which 37 (47.4%) were real studies and 7 (9.0%) were correctly summarized. On average, each response included 3.25 (standard deviation (SD): 0.74) studies, of which 44.0% (SD: 44.2%) were real studies and 7.8% (SD: 14.6%) were correctly summarized. The proportion of correctly summarized studies was not significantly different between common vs uncommon cancers [p = 0.29], between questions that specified randomized-control trials (Q3) vs not (Q1 or Q2) [p = 0.94], or between questions that specified intensity modulated radiotherapy (Q2) vs not (Q1 or Q3) [p = 0.31]. Across the three iterations of ChatGPT queries for breast cancer, the number of studies listed for Q1, Q2, and Q3 ranged from 3 to 5, 2 to 3, and 3 to 5, respectively; the number of correctly summarized studies listed for each question ranged from 0 to 2, 0 to 1, and 0 to 1, respectively.

CONCLUSION

ChatGPT's responses consistently included a large proportion of non-existent and incorrectly summarized studies. Furthermore, our secondary analysis suggests variability in the content and accuracy of ChatGPT responses to identical questions, raising further concerns regarding reliability. Overall, our findings argue against the use of ChatGPT as a tool for reviewing literature related to radiation oncology.

Multi-Institutional Outcomes Following Stereotactic Radiosurgery for Gastrointestinal Brain Metastases

PURPOSE/OBJECTIVE(S)

Outcomes following stereotactic radiosurgery (SRS) for gastrointestinal (GI) brain metastases (BM) are poorly defined. We analyzed our multi-institutional database of SRS patients, comparing outcomes between GI and non-GI BM patients after SRS.

MATERIALS/METHODS

We retrospectively identified all patients completing an initial SRS course across two institutions from 1/2015-12/2020. Demographic and clinical parameters were manually captured. Intracranial progression (ICP) was defined as any concern on post-SRS imaging for recurrence determined by multidisciplinary consensus. Overall survival (OS) and freedom from ICP (FFICP) were estimated via Kaplan Meier models. Cox proportional hazard models were used to assess associations between ICP and parameters.

RESULTS

Among 1383 total patients completing SRS for BM, 102 (7.4%) had GI BM. Among these, 46 (45.1%) were of colorectal (CRC) and 34 (33.3%) esophageal origin. Other GI sites (21.6%) included anal, pancreatic, gastric, GI of unknown origin, and hepatocellular carcinoma. Median follow up was 8.7 mos. GI BM patients were more likely to be younger (mean 59.1 vs 63.5 yrs, p = 0.001), male (56.9% vs 44.3%, p = 0.014 ), have more extracranial metastases (mean 1.9 vs 1.6, p = 0.003), have received systemic therapy (73.5% vs 63.9%, p = 0.049) or resection of BM (45.1% vs 25.0%, p < 0.001) prior to SRS, have larger planned target volumes of all BMs (mean 20.3 ccs vs 15.0 ccs, p = 0.013), and were less likely to receive whole brain radiation therapy (WBRT) prior to SRS (3.9% vs 10.8%, p = 0.028) or systemic therapy after SRS (54.9% vs 68.9%, p = 0.004). Among GI patients, median OS was 28.2 mos (95% CI 16.5-35.3), with no significant differences between GI and non-GI patients (p = 0.220) or among GI subgroups (CRC vs other GI: p = 0.731; esophageal vs other GI: p = 0.478). Median FFICP was significantly worse for GI patients (6.2 mos, 95% CI 4.0-9.6 mos) than for non-GI patients (12.4 mos, 95% CI 10.8-13.9 mos; p = 0.004). After accounting for age, sex, performance status, number of irradiated BMs, extracranial disease burden, extracranial disease control, interval from primary cancer diagnosis to BM diagnosis, resection status, receipt of prior WBRT, and receipt of post-SRS systemic therapy, GI origin was significantly associated with worse FFICP (HR 1.50, 95% CI 1.15-2.02, p = 0.007). FFICP was not significantly different between GI subgroups, with CRC and esophageal patients demonstrating median times to ICP of 5.0 mos (95% CI 3.4-9.6) and 7.2 mos (95% CI 2.7-14.1), respectively. Only 2 GI patients (2.0%) had ICP at site of prior SRS.

CONCLUSION

Across a modern, multi-institutional SRS cohort comparing GI to non-GI primary patients, BMs of GI origin demonstrated inferior FFICP to those of non-GI origin. OS did not vary significantly across GI and non-GI cases. Among GI subtypes, no significant differences were identified across FFICP or OS. These data may help inform treatment decisions and post-SRS surveillance.

Clinical Outcomes Following an Initial Stereotactic Radiosurgery Course for Brain Metastases from Melanoma

PURPOSE/OBJECTIVE(S)

Brain metastases (BM) are common in melanoma patients. The effect of gene mutations is not well characterized since first-line metastatic therapy has shifted from chemotherapy (CHT) to molecularly targeted therapies (TT) and immunotherapy (IO). We report outcomes of melanoma BM patients stratified by molecular subtype and pre-stereotactic radiosurgery (SRS) systemic therapy.

MATERIALS/METHODS

We identified all patients completing an initial SRS course for BM at two institutions between 1/2015 and 12/2020. Patients who had prior WBRT and/or resection were eligible. Demographic and clinical parameters were collected, along with melanoma tumor molecular characteristics. Intracranial progression (ICP) was defined as any radiographic distant and/or in-field progression per multidisciplinary consensus. Overall survival (OS) and freedom from ICP (FFICP) were estimated via the Kaplan Meier method.

RESULTS

From a total of 1383 SRS BM patients, we identified 118 (8.5%) with melanoma. Median follow up was 8.7 months, median age 64 years (IQR 51-72), 81% had cutaneous origin, and 55% had a KPS of 90-100. Molecular subtypes included BRAF (45%), NRAS (9.3%), and c-KIT (3.4%). Overall, 61% received IO prior to SRS, while 25% and 9.3% received TT and CHT prior to SRS respectively. 60% of patients harboring a mutation received IO as first line therapy, 10% received TT, and 30% received both TT and IO prior to SRS. BRAFmut patients more likely to have received TT prior to SRS (43% vs 9.2%, p<0.001) compared to BRAFwt patients. Median OS was 9.7 months (95% CI 7.8-13) and was not significantly different from non-melanoma patients (p = 0.6). Median FFICP was worse for melanoma patients (5.9 mos, 95% CI 3.5-8.5) than non-melanoma patients (8.96 mos, 95% CI 8.2-9.7, p = 0.009). A total of 72 ICP events occurred, with 56 (77.8%) distant ICP cases, 3 (4.2%) in-field ICP, and 13 (18%) ICP events that were radionecrosis (RN) only. RN was associated with the presence of a targetable mutation (18% vs 2%, p = 0.006) and receipt of TT pre-SRS (36% vs 9.8%, p = 0.001). BRAFmut patients had significantly worse FFICP (3.8 mos, 95% CI 3.0-6.8) compared to BRAFwt patients (8.5 mos, 95% CI 5.8-30.2, p = 0.006), although median OS was not significantly different (9.6 mos, 95% CI 6.9-16 vs 10.7 mos, 95% CI 6.7-15.5, p = 0.8). NRASmut was associated with better FFICP (29 mos, 95% CI 2.94-NA, p = 0.02).

CONCLUSION

In this modern, multi-institutional cohort of SRS patients, melanoma BM patients had worse FFICP compared to non-melanoma BM patients, and BRAFmut patients had worse FFICP than BRAFwt patients. RN was associated with mutational status and receipt of TT pre-SRS. OS did not vary significantly across groups. This analysis may help inform systemic therapy decisions and future genomic studies for patients with BMs from melanoma.

Evaluating the Reliability of Chat-GPT Model Responses for Radiation Oncology Patient Inquiries

PURPOSE/OBJECTIVE(S)

To determine if ChatGPT, a popular deep learning text generation tool, accurately and comprehensively answers patient questions related to radiation oncology.

MATERIALS/METHODS

A total of 28 common patient-centered questions were selected across various radiation oncology content domains, including diagnosis (4), workup (3), treatment (8), toxicity (4), and survivorship (9). To assess whether ChatGPT could detect inaccurate assumptions and/or respond negatively, we included two "negative control" questions in the treatment and toxicity domains. All questions were applied to common cancer types (breast, non-small cell lung, prostate, p16+ oropharyngeal, and rectal), uncommon cancer types (hypopharyngeal, medulloblastoma, and vulvar), and colon cancer as an additional "negative control." The ChatGPT responses were graded as 0 for any incorrect information, 1 for missing essential content, and 2 for correct and appropriately comprehensive for the length of the response. Each response was graded by two blinded MD reviewers, with discordant answers resolved by a third MD reviewer. Score distribution was compared across content domains, question type ("negative control" vs other), cancer type, and cancer commonality using the Chi-squared test.

RESULTS

Overall, a total of 252 questions were submitted to ChatGPT. A total of 86 (34.1%) answers were found to contain inaccurate information, 66 (26.2%) contained correct information but were found to be missing essential context, and 100 (39.7%) responses to questions were graded as correct and comprehensive. There was no significant difference in response score by question domains (p = 0.07). However, there was significant difference in response score across cancer type (p<0.001). The top scoring cancer types were breast (grade 0 = 10%; grade 1 = 21%, grade 2 = 68%) and prostate (grade 0 = 18%, grade 1 = 25%, grade 2 = 57%), while the two lowest scoring cancer types were colon (grade 0 = 61%, grade 1 = 21%, grade 2 = 18%) and vulvar (grade 0 = 50%, grade 1 = 25%, grade 2 = 25%). ChatGPT responses were also significantly different among common, uncommon and negative control questions, with the model performing best with responses to common cancer types (p = 0.003). ChatGPT performed significantly worse when responding to "negative control" questions (p<0.001).

CONCLUSION

ChatGPT failed to consistently generate accurate and comprehensive responses to the majority of radiation oncology patient centered questions, particularly across less common cancers and with "negative control" questions that included incorrect assumptions. This raises concern for the possible ChatGPT mediated reinforcement of patient misperceptions regarding radiotherapy.

Culture-negative TB: clinical characteristics, risk factors and treatment outcomes

BACKGROUND: Although culture remains the standard for TB diagnosis, 15-20% of patients diagnosed and treated for TB are culture-negative. We explored clinical characteristics, risk factors and treatment outcomes for culture-negative TB in a Peruvian cohort.METHODS: We recruited 4,500 index TB patients and 10,160 household contacts in Lima, Peru, and enrolled 692 secondary patients diagnosed with TB during follow-up of household contacts. We analyzed smear and culture status, sociodemographic factors, clinical characteristics and TB treatment outcomes to compare culture-negative and positive patients.RESULTS: Of the 4,880 adult patients, 915 (18.8%) were culture-negative. Culture-negative patients were less likely to report symptoms of TB disease and disease of longer duration. A multivariate analysis showed no statistically significant difference in loss to follow-up, treatment failure or recurrence between the culture-negative and -positive groups but a higher rate of death among culture-negative patients with an adjusted OR of 1.65 (95% CI 1.05-2.60). In a multivariate analysis of determinants of culture negativity, older age, substance use and being a secondary case were associated with culture status.CONCLUSIONS: More recognition and awareness of culture-negative TB is key for early and correct diagnosis to reduce transmission and improve treatment outcomes.

[Association of lean tissue index with arteriovenous fistula dysfunction in maintenance hemodialysis patients]

The clinical data of maintenance hemodialysis (MHD) patients from twenty hemodialysis centers in Guizhou province from June to September 2020 were collected by cross-sectional study. The patients were divided into AFD group and non-AFD group according to whether AFD had occurred. LTI was measured by body composition monitor. The results showed that the incidence of AFD in 2 781 MHD patients was 30.0% (835/2 781). Median LTI level was 15.2 (13.2, 17.5) kg/m². The LTI level in the AFD group was higher than that in the non-AFD group (P < 0.05). According to the tertiles of LTI, low LTI group (LTI ≤ 13.9 kg/m²) had the highest incidence of AFD (35.5%, 334/940), and the high LTI group had the lowest incidence of AFD (26.3%, 241/916), and the difference among the three groups was statistically significant (χ²=20.182,P < 0.001). Multivariate logistic regression analysis showed that low LTI group as the reference, the risk of AFD in moderate LTI group (13.9 kg/m² < LTI ≤ 16.6 kg/m²) and high LTI group were associated with the 20.0% (OR=0.800, 95% CI 0.650-0.986, P=0.036) and 22.8% (OR=0.772, 95% CI 0.616-0.966, P=0.024) decrease, respectively. These results suggest that low LTI level is independently associated with an increased risk of AFD in MHD patients.

Identifying a sphenoid sinus fungus ball using a nomogram model

Background: Sphenoid sinus fungus ball (SSFB) is a rare entity and usually presents with non-specific symptoms. SSFB could potentially lead to serious orbital and intracranial complications. Computed tomography (CT) scan is usually the first imaging test of the diagnostic workup in patients with specific clinical symptoms. This study aimed to compare the clinical characteristics and CT features between SSFB and unilateral (non-fungus ball) chronic sphenoid rhinosinusitis (USRS) and help differentiate between these two most common inflammatory diseases of the sphenoid sinus. Methods: By retrospective database review, 66 patients with a histopathologic diagnosis of isolated SSFB were recruited for analysis. Fifty-four patients who underwent endoscopic sinus surgery with clinical and histopathological diagnoses of USRS were enrolled as the control group. Clinical characteristics and CT features were evaluated. Results: Headache, rhinorrhoea, nasal obstruction, postnasal dripping, and hyposmia were the most common symptoms in both groups. In the univariate analysis, older age, lower white blood cell counts, irregular surface, bony dehiscence, lateral wall sclerosis, and intralesional hyperdensity (IH) were significant predictors for SSFB. Older age, irregular surface, and IH remained statistically significant in the multivariate analysis. Based on the results of the regression analysis, a nomogram for predicting the probability of SSFB was plotted. Conclusions: We developed a nomogram model as a novel preoperative diagnostic tool for identifying SSFB according to the predictors both in clinical characteristics and on CT features. This could help the clinicians in predicting the probability of SSFB, to reduce ineffective or delayed treatment and occurrence of complications.

Profiled polyethylene terephthalate filaments that incorporate collagen and calcium phosphate enhance ligamentisation and bone formation

Polyethylene terephthalate (PET) artificial ligaments offer an unlimited source of ligaments without donor-site-related morbidity and with good mechanical properties for a rapid return to sporting activities. Developing PET artificial ligaments with excellent ligamentisation and ligament-bone healing is still a considerable challenge. This study aimed to investigate the effects of the profiled PET/collagen/calcium phosphate (PET/C/CaP) ligament upon cell growth, ligamentisation and ligament-bone healing in vitro and in vivo. Profiled PET/C/CaP filaments were made by melt-spinning process with 2 % CaP hybrid spinning and collagen coating. Rat mesenchymal stem cells (MSCs) were cultured on the profiled PET/C filaments for cytotoxicity, viability, scanning electron microscopy (SEM) and ligament-related gene expression analysis. MSCs' osteogenic capacity on the profiled PET/CaP filaments was identified by detecting osteogenic gene expression and alizarin red S staining. For in vivo verification, an animal study was performed to evaluate the effect of the profiled PET/C/CaP ligament in a rabbit knee medial collateral ligament reinforcement reconstruction model. The graft ligamentisation and bone formation were investigated by SEM, histology, microcomputed tomography and mechanical tests. The profiled PET/C filaments enhanced MSC proliferation and ligament-related gene expression. Furthermore, they enhanced osteogenic gene expression, alkaline phosphatase activity and mineralisation of MSCs. The in vivo study indicated that the profiled PET/C/CaP ligament enhanced ligamentous matrix remodelling and bone formation. Therefore, their use is an effective strategy for promoting MSCs' ligamentous and osteogenic potential in vitro and enhancing ligamentous matrix remodelling and bone formation in vivo.

Lithium upregulates growth-associated protein-43 (GAP-43) and postsynaptic density-95 (PSD-95) in cultured neurons exposed to oxygen-glucose deprivation and improves electrophysiological outcomes in rats subjected to transient focal cerebral ischemia following a long-term recovery period

OBJECTIVES

Lithium has numerous neuroplastic and neuroprotective effects in patients with stroke. Here, we evaluated whether delayed and short-term lithium treatment reduces brain infarction volume and improves electrophysiological and neurobehavioral outcomes following long-term recovery after cerebral ischemia and the possible contributions of lithium-mediated mechanisms of neuroplasticity.

METHODS

Male Sprague Dawley rats were subjected to right middle cerebral artery occlusion for 90 min, followed by 28 days of recovery. Lithium chloride (1 mEq/kg) or vehicle was administered via intraperitoneal infusion once per day at 24 h after reperfusion onset. Neurobehavioral outcomes and somatosensory evoked potentials (SSEPs) were examined before and 28 days after ischemia-reperfusion. Brain infarction was assessed using Nissl staining. Primary cortical neuron cultures were exposed to oxygen-glucose deprivation (OGD) and treated with 2 or 20 μM lithium for 24 or 48 h; subsequent brain-derived neurotrophic factor (BDNF), growth-associated protein-43 (GAP-43), postsynaptic density-95 (PSD-95), and synaptosomal-associated protein-25 (SNAP-25) levels were analyzed using western blotting.

RESULTS

Compared to controls, lithium significantly reduced infarction volume in the ischemic brain and improved electrophysiological and neurobehavioral outcomes at 28 days post-insult. In cultured cortical neurons, BDNF, GAP-43, and PSD-95 expression were enhanced by 24- and 48-h treatment with lithium after OGD.

CONCLUSION

Lithium upregulates BDNF, GAP-43, and PSD-95, which partly accounts for its improvement of neuroplasticity and provision of long-term neuroprotection in the ischemic brain.Abbreviations: BDNF: brain-derived neurotrophic factor; ECM: extracellular matrix; EDTA: ethylenediaminetetraacetic acid; GAP-43: growth-associated protein-43; GSK-3β: glycogen synthase kinase-3β; HBSS: Hank's balanced salt solution; LCBF: local cortical blood perfusion; LDF: laser-Doppler flowmetry; MCAO: middle cerebral artery occlusion; MMP: matrix metalloproteinase; NMDA: N-methyl-D-aspartate; NMDAR: N-methyl-D-aspartate receptor; OCT: optimal cutting temperature compound; OGD: oxygen-glucose deprivation; PSD-95: postsynaptic density-95; SDS: sodium dodecyl sulfate; SNAP-25: synaptosomal-associated protein-25; SSEP: somatosensory evoked potential.

Enterovirus A71 Induces Neurological Diseases and Dynamic Variants in Oral Infection of Human SCARB2-Transgenic Weaned Mice

Enterovirus A71 (EV-A71) and many members of the Picornaviridae family are neurotropic pathogens of global concern. These viruses are primarily transmitted through the fecal-oral route, and thus suitable animal models of oral infection are needed to investigate viral pathogenesis. An animal model of oral infection was developed using transgenic mice expressing human SCARB2 (hSCARB2 Tg), murine-adapted EV-A71/MP4 virus, and EV-A71/MP4 virus with an engineered nanoluciferase gene that allows imaging of viral replication and spread in infected mice. Next-generation sequencing of EV-A71 genomes in the tissues and organs of infected mice was also performed. Oral inoculation of EV-A71/MP4 or nanoluciferase-carrying MP4 virus stably induced neurological symptoms and death in infected 21-day-old weaned mice. In vivo bioluminescence imaging of infected mice and tissue immunostaining of viral antigens indicated that orally inoculated virus can spread to the central nervous system (CNS) and other tissues. Next-generating sequencing further identified diverse mutations in viral genomes that can potentially contribute to viral pathogenesis. This study presents an EV-A71 oral infection murine model that efficiently infects weaned mice and allows tracking of viral spread, features that can facilitate research into viral pathogenesis and neuroinvasion via the natural route of infection. IMPORTANCE Enterovirus A71 (EV-A71), a positive-strand RNA virus of the Picornaviridae, poses a persistent global public health problem. EV-A71 is primarily transmitted through the fecal-oral route, and thus suitable animal models of oral infection are needed to investigate viral pathogenesis. We present an animal model of EV-A71 infection that enables the natural route of oral infection in weaned and nonimmunocompromised 21-day-old hSCARB2 transgenic mice. Our results demonstrate that severe disease and death could be stably induced, and viral invasion of the CNS could be replicated in this model, similar to severe real-world EV-A71 infections. We also developed a nanoluciferase-containing EV-A71 virus that can be used with this animal model to track viral spread after oral infection in real time. Such a model offers several advantages over existing animal models and can facilitate future research into viral spread, tissue tropism, and viral pathogenesis, all pressing issues that remain unaddressed for EV-A71 infections.

O-086 End-to-end deep learning for recognition of ploidy status using time-lapse videos

Study question

Our Retrospective study is to investigate an end-to-end deep learning model in identifying ploidy status through raw time-lapse video.

Summary answer

Our deep learning model demonstrates a proof of concept and potential in recognizing the ploidy status.

What is known already

Since the time-lapse system has been introduced into the IVF lab, the relationship between morphogenetic and ploidy status has been often discussed. However, the result has not yet reached a united conclusion due to some limitations such as human labeling. Besides the statistical approach, deep learning models have been utilized for ploidy prediction. As such approaches are single image-based, the performance remains unpromising as previous statistical-based research. Therefore, in order to move further toward clinical application, better research design and approach are needed.

Study design, size, duration

A retrospective analysis of the time-lapse videos and chromosomal status from 690 biopsied blastocysts cultured in a time-lapse incubator (EmbryoScope+, Vitrolife) between January 2017 and August 2018 in the Lee Women’s Hospital were assessed. The ploidy status of the blastocyst was derived from the PGT-A using high-resolution next-generation sequencing (hr-NGS). Embryo videos were obtained after normal fertilization through the intracytoplasmic sperm injection or conventional insemination.

Participants/materials, setting, methods

By randomly dividing the data into 80% and 20%, we developed our deep learning model based on Two-Stream Inflated 3D ConvNets(I3D) network. This model was trained by the 80% time-lapse videos and the PGT-A result. The remaining 20% has been tested by feeding the time-lapse video as input and the PGT-A prediction as output. Ploidy status was classified as Group 1 (aneuploidy) and Group 2 (euploidy and mosaicism).

Main results and the role of chance

Time-lapse videos were divided into 3-time partitions: day 1, day 1 to 3, and day 1 to 5. Deep learning models have been fed by RGB and optical flow. Combining 3 different time partitions with RGB, optical flow, and fused result from RGB and optical flow, we received nine sets of test results. According to the results, the longest time partition with the fusion method has the highest AUC result as 0.74, which appeared higher than the other eight experimental settings with a maximum increase of 0.17.

Limitations, reasons for caution

The present study is retrospective and future prospective research would help us to identify more key factors and improve this model. In addition, expanding sample size combined with cross-centered validation will also be considered in our future approach.

Wider implications of the findings

Group 1 and Group 2 approach provided deselection of aneuploidy embryos, while future deep learning approaches toward high mosaicism, low mosaicism, and euploidy will be needed, in order to provide a better clinical application.

Trial registration number

CS18082

P–009 A modified sperm chromatin dispersion test, LensHooke® R10, for quick and accurate determination of human sperm DNA fragmentation

Study question

The performance and efficiency of the LensHooke® R10 test kit were evaluated by the clinical examination for precision, accuracy, and time.

Summary answer

The LensHooke® R10 based on sperm chromatin dispersion test offers not only quick testing for sperm DNA fragmentation but also reliable and accurate test results.

What is known already

Sperm chromatin dispersion (SCD) test, one of the most commonly used testing for sperm DNA fragmentation (SDF), can be conducted promptly and without the need for expensive laboratory instruments. However, the main disadvantage of the SCD test is inter-observer variability in categorizing the size of characteristics halos surrounding the core of sperm. Moreover, it takes more than one hour to accomplish whole assay procedures making this testing an inefficient diagnostic tool. These may hinder its broad availability among andrology laboratories or prevent it from being routinely used for the evaluation of male infertility.

Study design, size, duration

A total of 108 participants was included in this prospective study. Data was collected from the reproductive medicine center between June and December 2020.

Participants/materials, setting, methods

This study included 108 consecutive male partners of couples attending for assisted reproductive treatment. SDF was simultaneously tested by using LensHooke® R10 (R10) and Halosperm® G2 (G2) respectively. We evaluated the correlation and agreement between two SCD-based test kits. The repeatability and reproducibility of the SCD kits were assessed by intra-and inter-observer agreement experiments. The sensitivity, specificity, positive predictive value, negative predictive value for the R10 was determined by receiver operator characteristics (ROC) curve analysis.

Main results and the role of chance

The R10 produced more clear sperm core and dispersed chromatin, therefore highly recognizable images can be easily and accurately categorized when scoring of SDF. It took 50% less time for SDF testing by the R10 compared to the G2 (38.26 ± 9.85 minutes vs. 76.52 ± 19.7 minutes, P &lt; 0.0001). The SDF% results showed a strong correlation for the R10 and G2 with Spearman’s coefficients of rank correlation (rho) above 0.8 (P &lt; 0.0001, N = 108). The R10 showed 89.8% accuracy with 87.9% sensitivity, 90.8% specificity, 82.9% PPV, and 93.7% NPV on the measurement of SDF% at the threshold value of 22%. Intraclass correlation coefficients (ICC) &gt;0.9 showed a strong agreement between two observers on the testing of SDF using the R10. ICC &gt;0.9 showed a high intra-observer agreement within 4 repeated testing on SDF using the R10. The R10 showed an intra-observer’s precision of coefficient variation, CV &lt; 10% for SDF%. In addition, SDF% test results obtained by the R10 for asthenospermic (31.8% ± 16.7%), teratospermic (22.9% ± 14.4%), and oligoasthenoteratozoospermic samples (36.6% ± 14.4%) were significantly higher than that observed in normozoospermic samples (15.3% ± 10.2%, p &lt; 0.05), was comparable with the G2.

Limitations, reasons for caution

The sample size of 4 semen specimens used to evaluate the intra-and inter-observer agreement was a limitation. Besides, evaluating the relationship between the SDF and clinical outcome of ART is necessary for further study.

Wider implications of the findings: The new in vitro diagnostics reagent, LensHooke® R10, is a simple and quick test kit that offers reliable and accurate test results of sperm DNA fragmentation, can be routinely used in male infertility evaluation.

Trial registration number

CS2–20012

75Safety and efficacy of rivaroxaban in combination with anti-arrhythmic drugs in patients with non-permanent atrial fibrillation

Background

Rivaroxaban is useful for stroke prevention in atrial fibrillation (AF) patients. Most patients with non-permanent AF also treated with anti-arrhythmic drugs (AADs) to prevent the recurrence of arrhythmia. But there are limited data regarding drug-drug interactions between rivaroxaban and AADs despite its high clinical relevance.

Purpose

To compare the bleeding risks and ischemic events between the use of rivaroxaban alone and the concomitant use of AADs.

Methods

This is a multicenter retrospective study, which identified patients with a diagnosis of non-permanent AF who received rivaroxaban more than 1 month between December 1, 2011 and November 30, 2016. The study divided patients into 4 groups : rivaroxaban alone, combined with amiodarone, dronedarone and propafenone. We compared the clinical events and cumulative incidences to compare the endpoints including efficacy endpoint (new ischemic stroke, intracranial hemorrhage, or new

embolism), safety endpoints (Hb fall more than 2g/dL or transfusion more than 2U PRBC, critical site bleeding, or fatal bleeding.) and major adverse cardiovascular events (MACE), including cardiovascular death, myocardial infarction, new ischemic stroke, new embolism, or intracranial hemorrhage.

Results

Of 1777 enrolled patients, the rivaroxaban alone was 1205 cases, 177 in amiodarone group, 231 in dronedarone group and 164 in propafenone group. There was no statistically significant difference on efficacy endpoints, safety endpoints and MACE between the 4 groups. The average dosage of rivaroxaban was insignificantly the lowest in the group combined with dronedarone (12.3mg, p = 0.146). The rate of new embolism (0%, p = 0.029), recurrent heart failure admission rate (3.9%, p &lt; 0.001), and all-cause mortality (3.0%, p = 0.013) in dronedarone group showed a significant lower occurrence rate. The occurrence rate of new ischemic stroke (0.9%, p = 0.549), new hemorrhagic stroke (0.4%, p = 0.546), efficacy endpoints (1.7%, p = 0.369) and MACE (3.9%, p = 0.72) in dronedarone droup were the lowest but insignificant. The cumulative incidences of efficacy endpoints, safety endpoints and MACE during follow-up period were also similar in these four groups.(Picture 1)

Conclusions

In patients with non-permanent atrial fibrillation, this real-world study showed that there were no significant differences between using rivaroxaban alone or concomitant with an AAD (dronedarone/amiodarone/propafenone) on events such as new ischemic stroke, intracranial hemorrhage, GI bleeding and MACEs. The happening of new embolism was lower especially in the group combined with dronedarone. The safety and efficacy between rivaroxaban alone and combined with rhythm control using AADs proved to be the same.  Relative low dose rivaroxaban combined with dronedarone did not increase the bleeding risk, and may decrease the probability of thromboembolism.

Abstract Figure. Picture 1

P1064Using Data Mining to Predict Bleeding Events caused by Novel Oral Anticoagulants

Background

Novel oral anticoagulants (NOAC) is important in preventing thromboembolism in atrial fibrillation (AF) patients. Bleeding risk was evaluated by HAS-BLED score traditionally. Data mining is a relatively new discipline that has sprung up at the confluence of several other disciplines, driven primarily by the growth of large databases. 

Purpose

This study aimed to find a useful predictive model by data mining to assess the risk of rivaroxaban, an antithrombotic drug that causes bleeding in AF patients. The seven parameters of the HAS-BLED score were used to predict the effect of rivaroxaban on bleeding tendency in AF patients and may provide clinicians with appropriate treatments to avoid complications from bleeding events and reduce the incidence of health damage.

Methods

Through conducting a multicenter retrospective study, we identified patients with AF who were treated with rivaroxaban for more than 1 month between December 1, 2011 and November 30, 2016. After preprocessing, the established data were used for training and testing of data mining models. This study evaluated four models, including association rules, neural networks, Bayesian classification, and decision trees.

Result

Of the 872 enrolled cases, 432 were in any of the bleeding groups and 432 were in the non-bleeding randomized control group. After comparing the overall classification accuracy, omission error and over-prediction error, the decision tree proved to be the most accurate model for bleeding prediction. The overall classification accuracy is 77%, the omission error is 15%, the over-prediction error is 21.9%, and the AUC score is 0.84. The results show that the model has good discriminative ability and visibility of decision rules.

Conclusion

Among several data mining models, decision tree proved to be the most accurate model for bleeding prediction. The conclusion of this study can be used as a reference for supporting decision making before anticoagulation treatment and suggest future research to compare efficacy of bleeding prediction between HAS-BLED score and decision tree.

Data mining comparison Model Omission error Commission error Overall accuracy AUC score Ranking Decision tree 15.0% 21.90% 77.00% 0.84 1 Association rules 16.8% 27.20% 76.50% 0.81 2 Neural networks 12.0% 26.40% 78.20% 0.83 3 Bayesian classification 16.1% 27.50% 76.50% 0.83 4

Effect of novel atmospheric-pressure jet pretreatment on the drying kinetics and quality of white grapes

BACKGROUND

Raisin is a popular snack and a common constituent of many foods owing to its good flavor and nutritional value. Conventional drying of grapes can be a slow and energy-consuming process as their waxy surface hinders efficient moisture migration. A drying pretreatment that disrupts the waxy cuticle is usually applied to increase the drying rate.

RESULTS

The application of an atmospheric-pressure air plasma jet to the grape surface could effectively enhance the drying kinetics and decrease the drying time by more than 20%. Through etching of the waxy cuticle, the air plasma jet optimally improves the quality of the final product. Although the surface hydrophilicity was increased by 40%, the physical appearance, color, and texture of plasma-treated raisins were similar to the product from untreated control and chemical-treated groups. A more than twofold increase in the total phenolic content and antioxidant capacity was observed when compared to other experimental groups.

CONCLUSIONS

The results indicate that atmospheric plasma could be a better option than using chemicals to pretreat grapes before drying since it leaves no toxic residue, while successfully preserving the product quality. This work shows the great potential for the application of atmospheric air plasma in the drying of food materials. © 2019 Society of Chemical Industry.

A nonsense mutant of the hepatitis B virus large S protein antagonizes multiple tumor suppressor pathways through c-Jun activation domain-binding protein1

Hepatitis B virus (HBV) is a major cause of hepatocellular carcinoma (HCC). Previous studies have identified recurrent nonsense mutations in the HBV large S (LHBs) gene from the liver from HBV core antigen-positive HCC patients. These nonsense mutants have been shown to be oncogenic in mouse xenograft models using a mouse embryonic fibroblast cell line. Here, we expressed in a liver cell line Huh-7 a carboxy terminally truncated protein from a nonsense mutant of the LHBs gene, sW182* (stop codon at tryptophane-182). Although the sW182* protein appeared not to be very stable in the cultured liver cells, we confirmed that the protein can be highly expressed and retained for a prolonged period of time in the hepatocytes in the mouse liver, indicating its stable nature in the physiological condition. In the Huh-7 cells, the sW182* mutant downregulated tumor suppressors p53 and Smad4. This downregulation was reversed by a proteasome inhibitor MG132, implying the involvement of proteasome-based protein degradation in the observed regulation of the tumor suppressors. On the other hand, we found that c-Jun activation domain-binding protein 1 (Jab1) physically interacts with the sW182*, but not wild-type LHBs. RNA interference (RNAi) of Jab1 restored the levels of the downregulated p53 and Smad4. The sW182* mutant inhibited the promoter activity of downstream target genes of the tumor suppressors. Consistently, Jab1 RNAi reversed the inhibition. These results suggest that the LHBs nonsense mutant antagonizes the tumor suppressor pathways through Jab1 in the liver contributing to HCC development.

Predicting Vaginal Delivery in Nulliparous Women Undergoing Induction of Labor at Term

OBJECTIVE

We sought to develop a model to calculate the likelihood of vaginal delivery in nulliparous women undergoing induction at term.

STUDY DESIGN

We obtained data from the Consortium on Safe Labor by including nulliparous women with term singleton pregnancies undergoing induction of labor at term. Women with contraindications for vaginal delivery were excluded. A stepwise logistic regression analysis was used to identify the predictors associated with vaginal delivery by considering maternal characteristics and comorbidities and fetal conditions. The receiver operating characteristic curve, with an area under the curve (AUC) was used to assess the accuracy of the model.

RESULTS

Of 10,591 nulliparous women who underwent induction of labor, 8,202 (77.4%) women had vaginal delivery. Our model identified maternal age, gestational age at delivery, race, maternal height, prepregnancy weight, gestational weight gain, cervical exam on admission (dilation, effacement, and station), chronic hypertension, gestational diabetes, pregestational diabetes, and abruption as significant predictors for successful vaginal delivery. The overall predictive ability of the final model, as measured by the AUC was 0.759 (95% confidence interval, 0.749-0.770).

CONCLUSION

We identified independent risk factors that can be used to predict vaginal delivery among nulliparas undergoing induction at term. Our predictor provides women with additional information when considering induction.

Revealing the nature of low-temperature photoluminescence peaks by laser treatment in van der Waals epitaxially grown WS2 monolayers

Monolayers of transition metal dichalcogenides (TMD) are promising materials for optoelectronics devices. However, one of the challenges is to fabricate large-scale growth of high quality TMD monolayers with the desired properties in order to expand their use in potential applications. Here, we demonstrate large-scale tungsten disulfide (WS₂) monolayers grown by van der Waals Epitaxy (VdWE). We show that, in addition to the large structural uniformity and homogeneity of these samples, their optical properties are very sensitive to laser irradiation. We observe a time instability in the photoluminescence (PL) emission at low temperatures in the scale of seconds to minutes. Interestingly, this change of the PL spectra with time, which is due to laser induced carrier doping, is employed to successfully distinguish the emission of two negatively charged bright excitons. Furthermore, we also detect blinking sharp bound exciton emissions which are usually attractive for single photon sources. Our findings contribute to a deeper understanding of this complex carrier dynamics induced by laser irradiation which is very important for future optoelectronic devices based on large scale TMD monolayers.

Comparing the Chinese versions of two knee-specific questionnaires (IKDC and KOOS): reliability, validity, and responsiveness

BACKGROUND

The International Knee Documentation Committee Subjective Knee Form (IKDC) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) are knee-specific questionnaires that have been widely used and translated into numerous languages. However, the differences in the psychometric properties between the Chinese IKDC and KOOS remain unclear. The purpose of this study was to conduct a cross-cultural adaptation of the Chinese IKDC and Chinese KOOS and to compare the psychometric properties of these two measures in patients with various knee injuries from the acute stage up to 12 weeks after receiving treatment.

METHODS

The original IKDC and KOOS were translated into Chinese based on the guidelines of cross-cultural adaptation and translation protocols. One hundred and seventy-three patients with various knee injuries were recruited in this study and completed both Chinese IKDC and Chinese KOOS as well as a generic health status questionnaire (Chinese Short Form-36 [SF-36]). The reliability, internal consistency, content validity, convergent and divergent validity and responsiveness of both IKDC and KOOS were assessed with appropriate indices.

RESULTS

The Chinese IKDC showed excellent reliability (ICC = 0.97) and strong internal consistency (Cronbach alpha = 0.87). The Chinese KOOS also presented good reliability with ICCs ranging from 0.89 to 0.95 and internal consistency (Cronbach alpha coefficients ranging from 0.76 to 0.97). The content validity of these two questionnaires were excellent, yielding no floor or ceiling effects. Both the Chinese IKDC and KOOS were highly associated with the physical component summary (PCS) score and weakly related to the mental component summary (MCS) score of the SF-36. Responsiveness to change was large (effect size =0.95) for the Chinese IKDC and moderate (effect sizes = 0.49~0.60) at 12-week after physical therapy.

CONCLUSION

Both the Chinese IKDC and KOOS demonstrated good psychometric properties. However, the Chinese IKDC was more sensitive to changes over a period of 2, 4, 8, 12 weeks of physical therapy than the Chinese KOOS. The ROC analyses revealed a value of area under the curve (0.83 for the Chinese IKDC and 0.67-0.79 for the subscales of Chinese KOOS). Minimal clinically important difference values were 9.8 for the Chinese IKDC and 0.79, 0.76, 0.76, 0.76, 0.67 for the Symptoms, Pain, Activities of Daily Living, Sport/Recreation, and Quality of Life subscales of Chinese KOOS, respectively. The current study provides information for clinicians and researchers to use these appraisal tools for Chinese-speaking patients with various knee disorders.

Clinical analysis of submucosal Medpor implantation for empty nose syndrome

BACKGROUND

Empty nose syndrome (ENS) describes symptomatology and radiographic findings after surgeries on turbinates.The treatment of ENS is still debatable.

PURPOSE

To analyse clinical outcomes of submucosal Medpor® implantation for ENS.

METHODS

A total of 18 patients underwent submucosal Medpor® implantation from 2006 to 2011. We applied SNOT-22 (SinoNasalOutcome Test) for statistical survey of the patients' symptoms before and after surgery.

RESULTS

Two patients were lost to follow up after the surgery. Most of the patients developed ENS-related symptoms gradually within 2 years to 16 years after the previous nasal surgery or treatment. The sites of submucosal implantation are mainly septum and nasal floor, unilaterally or bilaterally. There is a significant improvement of SNOT-22 pre-operatively to one year post-operatively.

CONCLUSIONS

The symptomatolgy remains the most important point when dealing with patients with ENS. Submucosal implantation of Medpor® is a feasible surgical treatment to ENS. A positive cotton test is suggested for the surgical indication and planning.

Effect of tobacco smoke on hydrogen sulfide-induced rat thoracic aorta relaxation

Levels of hydrogen sulfide (H₂S), a gaseous signaling molecule, are reduced in the serum of individuals who smoke. We hypothesized that tobacco smoke influenced smooth muscle relaxation by decreasing H₂S levels and this effect could also influence expression of cystathionine γ-lyase (CSE) and sulfonylurea receptor-2 (SUR-2). The aim of this study was to explore the effect of tobacco smoke on H₂S-mediated rat thoracic aorta relaxation and its possible mechanism. Thirty-two Sprague-Dawley rats were divided into four groups: control (C) group, short-term smoker (SS) group, mid-term smoker (MS) group, and long-term smoker (LS) group. H₂S concentrations in serum, action of H₂S on rat aortic vascular relaxation, and expression of CSE and SUR-2 in thoracic aortic smooth muscle were measured. Although there was no significant difference in H₂S between the C and the SS groups, concentration of H₂S was significantly reduced in both the LS and MS groups compared to control (P<0.01). Furthermore, H₂S was significantly lower in the LS than in the MS group (P<0.05). Rat aortic vascular relaxation was lower in all three treatment groups compared to the control, with the most significant decrease observed in the LS group (P<0.05 compared to the MS group). Expression of CSE and SUR-2 was reduced in the LS and MS groups compared to control (P<0.05), with the lowest levels observed in the LS group (P<0.05). Therefore, tobacco smoke reduced expression of CSE and SUR-2 in rat thoracic aorta, which may inhibit H₂S production and vascular dilation.

DnaT is a PriC-binding protein

DnaT and PriC are replication restart primosomal proteins required for re-initiating chromosomal DNA replication. DnaT is a component of the PriA-dependent primosome, while PriC belongs to the PriC-dependent primosome. Whether DnaT can interact with PriC is still unknown. In this study, we define a direct interaction between PriC, a key initiator protein in PriC-mediated DNA replication restart, and DnaT, a DnaB/C complex loader protein, from Klebsiella pneumoniae. In fluorescence titrations, PriC bound to single-stranded DNA with a binding-site size of approximately 9 nt. Gold nanoparticle assay showed that the solution of DnaT-PriC changed from red to purple, which indicated the protein-protein interactions due to gold nanoparticle aggregate. In addition, this DnaT-PriC complex could be co-purified by the heparin HP column. Surface plasmon resonance analysis showed that the Kd value of DnaT bound to PriC was 2.9 × 10(-8) M. These results constitute a pioneering study of the DnaT-PriC interaction and present a putative link between the two independent replication restart pathways, namely, PriA- and PriC-dependent primosome assemblies. Further research can directly focus on determining how DnaT binds to the PriC-SSB-DNA tricomplex and regulates the PriC-dependent replication restart.

Characterization of Staphylococcus aureus Primosomal DnaD Protein: Highly Conserved C-Terminal Region Is Crucial for ssDNA and PriA Helicase Binding but Not for DnaA Protein-Binding and Self-Tetramerization

The role of DnaD in the recruitment of replicative helicase has been identified. However, knowledge of the DNA, PriA, and DnaA binding mechanism of this protein for the DnaA- and PriA-directed replication primosome assemblies is limited. We characterized the DNA-binding properties of DnaD from Staphylococcus aureus (SaDnaD) and analyzed its interactions with SaPriA and SaDnaA. The gel filtration chromatography analysis of purified SaDnaD and its deletion mutant proteins (SaDnaD1-195, SaDnaD1-200 and SaDnaD1-204) showed a stable tetramer in solution. This finding indicates that the C-terminal region aa 196-228 is not crucial for SaDnaD oligomerization. SaDnaD forms distinct complexes with ssDNA of different lengths. In fluorescence titrations, SaDnaD bound to ssDNA with a binding-site size of approximately 32 nt. A stable complex of SaDnaD1-195, SaDnaD1-200, and SaDnaD1-204 with ssDNA dT40 was undetectable, indicating that the C-terminal region of SaDnaD (particularly aa 205-228) is crucial for ssDNA binding. The SPR results revealed that SaDnaD1-195 can interact with SaDnaA but not with SaPriA, which may indicate that DnaD has different binding sites for PriA and DnaA. Both SaDnaD and SaDnaDY176A mutant proteins, but not SaDnaD1-195, can significantly stimulate the ATPase activity of SaPriA. Hence, the stimulation effect mainly resulted from direct contact within the protein-protein interaction, not via the DNA-protein interaction. Kinetic studies revealed that the SaDnaD-SaPriA interaction increases the Vmax of the SaPriA ATPase fivefold without significantly affecting the Km. These results indicate that the conserved C-terminal region is crucial for ssDNA and PriA helicase binding, but not for DnaA protein-binding and self-tetramerization.

Inhibition of Staphylococcus aureus PriA Helicase by Flavonol Kaempferol

Staphylococcus aureus is an important etiological agent responsible for healthcare-associated infections. In this study, the effect of flavonoids on the inhibition of S. aureus PriA (SaPriA), an essential helicase for DNA replication restart, which is critical for bacterial survival, was investigated. Using vanadate-sensitive colorimetric assay, the concentration of phosphate, from ATP hydrolysis by SaPriA, was decreased to 37 and 69 %, respectively, in the presence of 35 μM kaempferol and myricetin. The effect of quercetin, galangin, dihydromyricetin, and myricitrin was insignificant. From titration curve, IC₅₀ of kaempferol for SaPriA was determined to be 22 ± 2 μM. Using fluorescence quenching, we identified that kaempferol can bind to SaPriA with K_d of 9.1 ± 3.2 μM. To our knowledge, these preliminary results constituted the first study regarding that naturally occurring product such as flavonols kaempferol and myricetin can be potent inhibitors targeting PriA.

Stevens-Johnson syndrome and toxic epidermal necrolysis in patients with malignancies

BACKGROUND

Malignancy is known to be associated with an increased mortality rate in patients with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). However, risk factors contributing to the poor prognosis of patients with SJS/TEN with malignancies remain undefined.

OBJECTIVES

To explore the potential involvement of malignancy and its related factors contributing to the poor outcome of SJS/TEN, in a retrospective study.

METHODS

In total 517 patients with SJS/TEN were enrolled. Forty-seven who sustained various types of malignancies were analysed for numerous malignancy-related factors, including cancer types, clinical stages and chemotherapies given or not before the onset of SJS/TEN.

RESULTS

We found that the mortality rate of patients with SJS/TEN with malignancies was higher than that of patients without malignancies (32%, 15/47 vs. 8·5%, 40/470, respectively) (P < 0·001). The use of phenytoin was significantly higher in the malignancy group. The presence of hepatocellular carcinoma (80%, four of five; P < 0·001; odds ratio 43) and colorectal cancer (67%, two of three; P = 0·022; odds ratio 21·5) significantly increased the death rate of patients with SJS/TEN, whereas lung cancer and urothelial carcinoma did not. Patients who had received ongoing or recent chemotherapy showed higher mortality than those without chemotherapy (P = 0·022; odds ratio 4·95). Furthermore, among the 47 patients with SJS/TEN with malignancies, lower serum albumin, haemoglobin and platelet count were detected in the deceased patients than in the surviving patients before the onset of SJS/TEN.

CONCLUSIONS

Our results suggest that several factors related to malignancies, such as specific cancer types, chemotherapy and malnutrition, may contribute to poor prognosis in patients with malignancies developing SJS/TEN.

Prenatal air pollutant exposure and occurrence of atopic dermatitis

BACKGROUND

Hereditary and environmental factors have been related to the occurrence of atopic dermatitis (AD) in early childhood. However, the role of prenatal and early postnatal exposure to air pollutants has not been totally elucidated.

OBJECTIVES

To evaluate the association between prenatal air pollutant exposure and occurrence of AD.

METHODS

In total 24 200 infant-mother pairs were recruited to participate in the Taiwan Birth Cohort Study in 2005 using multistage stratified sampling. Medical history, including physician-diagnosed AD, was inquired by questionnaire at the infant's age of 6 months. Monthly averages of five criteria air pollutants - NO2 , CO, O3 , SO2 and PM10 - were retrieved from 66 air-quality-monitoring stations, and interpolated to all administrative districts using the kriging method. Exposure data during each of the three gestational trimesters and three months after birth were calculated for each study subject, and odds ratios (ORs) of AD occurrence were calculated by logistic regression.

RESULTS

Among the participants, 16 686 mother-infant pairs were qualified for and included in the analysis. Among them, 1206 infants (7·2%) had been diagnosed as having AD before the age of 6 months, and the prevalence was higher in boys (8·3%) than in girls (6·1%). The occurrence of AD was significantly associated with CO exposure during the whole gestational period [adjusted OR (aOR) 1·37, 95% confidence interval (CI) 1·06-1·78] and the first trimester (aOR 1·51, 95% CI 1·16-1·97). We did not observe any significant association among the other air pollutants during either the whole gestational period or any period of the three trimesters and 3 months after birth.

CONCLUSIONS

Our study found a relationship between AD occurrence and gestational exposure to CO, where exposure during the first trimester seemed to be the most important.

A Modified Particle Swarm Optimization Technique for Finding Optimal Designs for Mixture Models

Particle Swarm Optimization (PSO) is a meta-heuristic algorithm that has been shown to be successful in solving a wide variety of real and complicated optimization problems in engineering and computer science. This paper introduces a projection based PSO technique, named ProjPSO, to efficiently find different types of optimal designs, or nearly optimal designs, for mixture models with and without constraints on the components, and also for related models, like the log contrast models. We also compare the modified PSO performance with Fedorov's algorithm, a popular algorithm used to generate optimal designs, Cocktail algorithm, and the recent algorithm proposed by [1].

4-Phenylbutyric Acid (4-PBA) and Lithium Cooperatively Attenuate Cell Death during Oxygen-Glucose Deprivation (OGD) and Reoxygenation

Hypoxia is an important cause of brain injury in ischemic stroke. It is known that endoplasmic reticulum (ER) stress is an important determinant of cell survival or death during hypoxia. However, the signaling pathways and molecular mechanisms involved remain to be studied in more detail. To investigate whether inhibition of ER stress promotes neuroprotection pathways, we applied an in vitro oxygen-glucose deprivation (OGD) followed by reoxygenation model of human SK-N-MC neuronal cell cultures in this study. Our results showed that neuronal cell death was induced in this model during the OGD reoxygenation by the sustained ER stress, but not during OGD phase. However, treatment of the cultures with lithium with the OGD reoxygenation insult did not result in neuroprotection, whereas concomitant treatment of chemical chaperon 4-phenylbutyric acid (4-PBA) provides protective effects in ER stress-exposed cells. Moreover, 4-PBA rescued ER stress-suppressed Akt protein biosynthesis, which works cooperatively with lithium in the activation of Akt downstream signaling by inhibition of autophagy-induced cell death. Taken together, our finding provides a possible mechanism by which 4-PBA and lithium contribute to mediate neuroprotection cooperatively. This result may potentially be a useful therapeutic strategy for ischemic stroke.

Estrogen-dependent sushi domain containing 3 regulates cytoskeleton organization and migration in breast cancer cells

Aromatase inhibitors (AIs) are the standard endocrine therapy for postmenopausal breast cancer; however, currently used biomarkers, such as, estrogen receptor-alpha/progesterone receptor (ERα/PR), predict only slightly more than half of the potential responders to AI treatment. To identify novel markers of AI responsiveness, a genome-wide microarray analysis was performed using primary breast tumor samples from 50 postmenopausal women who later developed metastatic breast cancer. Sushi domain containing 3 (SUSD3) is a significantly differentially expressed gene, with 3.38-fold higher mRNA levels in AI-responsive breast tumors vs non-responders (P<0.001). SUSD3 was highly expressed in ERα-positive breast tumors and treatment with estradiol increased SUSD3 expression in ERα-positive breast cancer cells. Treatment with an antiestrogen or ERα knockdown abolished basal and estradiol-dependent SUSD3 expression. Recruitment of ERα upstream of the transcription start site of SUSD3 was demonstrated by chromatin immunoprecipitation-PCR. Flow cytometric analysis of SUSD3-knockdown cells revealed blunted estradiol effects on progression into S and M phases. SUSD3 was localized to the plasma membrane of breast cancer cells. SUSD3 knockdown decreased the appearance of actin-rich protrusions, stress fibers and large basal focal adhesions, while increasing the presence of cortical actin concomitant with a decrease in Rho and focal adhesion kinase activity. SUSD3-deficient cells demonstrated diminished cell spreading, cell-cell adhesion and motility. In conclusion, SUSD3 is a novel promoter of estrogen-dependent cell proliferation and regulator of cell-cell and cell-substrate interactions and migration in breast cancer. It may serve as a novel predictor of response to endocrine therapy and potential therapeutic target.

An isolated intracranial mucocoele herniated from the frontal sinus

Mucocoeles are chronic mucosa-lined retention cysts that occur due to sinus ostium obstruction and expand along the path of least resistance, most commonly involving the frontal sinus. A frontal mucocoele typically appears as a smooth and rounded expansile enlargement of a completely opacified frontal sinus, with or without thinning of the bony wall of the sinus. Here we report a rare case of isolated intracranial mucocoele that presented with posterior herniation to the anterior cranial fossa through a small bony defect on the posterior table of the frontal sinus. The findings upon imaging could easily be confused with intracranial abscess, potentially leading to craniotomy drainage. In the present case of mucocoele, the frontal intracranial lesion was completely resolved following endoscopic frontal sinusotomy.

YM155 down-regulates survivin and XIAP, modulates autophagy and induces autophagy-dependent DNA damage in breast cancer cells

BACKGROUND AND PURPOSE

The aim of this study was to determine the potency and molecular mechanism of action of YM155, a first-in-class survivin inhibitor that is currently under phase I/II clinical investigations, in various drug-resistant breast cancers including the oestrogen receptor positive (ER(+) ) tamoxifen-resistant breast cancer and the caspase-3-deficient breast cancer.

EXPERIMENTAL APPROACH

The potency of YM155 in SK-BR-3, MDA-MB-231, MCF7 and its tamoxifen-resistant sublines, TamR6, TamR7, TamR8, TamC3 and TamC6, were determined by MTT assay. Western blot analysis, flow cytometric analysis, reverse transcription-PCR, fluorescent microscopy and comet assay were used to determine the molecular mechanism of action of YM155 in different breast cancer cell lines.

KEY RESULTS

YM155 was equally potent towards the parental ER(+) /caspase-3-deficient MCF7 breast cancer cells and its tamoxifen-resistant sublines in vitro. The ER(-) /HER2(+) SK-BR-3 breast cancer cells and the triple-negative/caspase-3-expressing metastatic aggressive MDA-MB-231 breast cancer cells were also sensitive to YM155 with IC50 values in the low nanomolar range. Targeting survivin by YM155 modulated autophagy, induced autophagy-dependent caspase-7 activation and autophagy-dependent DNA damage in breast cancer cells. Interestingly, YM155 also induced XIAP degradation and the degradation of XIAP might play an important role in YM155-induced autophagy in breast cancer cells.

CONCLUSIONS AND IMPLICATIONS

YM155 is a potent survivin inhibitor that has potential for the management of various breast cancer subtypes regardless of the expression of ER, HER2 and caspase-3. Importantly, this study provides new insights into YM155's molecular mechanism of action and therapeutic potential in the treatment of tamoxifen-resistant breast cancer.

Resonant x-ray diffraction spectrum for possible structures of the smectic liquid crystal phase with a six-layer periodicity

With the discovery of the smectic-C(d6)(*) (SmC(d6)(*)) phase showing six-layer periodicity [S. Wang et al., Phys. Rev. Lett. 104, 027801 (2010)] and a recent report of the observation of a possible alternative structure, the need for a reliable and accurate method for distinguishing different possible structures is more urgent than ever. Through simulations using the tensorial structure factor method, we present the resonant x-ray diffraction (RXRD) spectra for different possible structures as proposed in several theoretical studies. Subtle distinctions between models are shown. The ability and limitations of RXRD as a technique for determining the structure of this particular phase is discussed.

Polymorphic microsatellite loci isolated from Cervus unicolor (Cervidae) show inbreeding in a domesticated population of Taiwan Sambar deer

Primers for eight microsatellites were developed; they successfully amplified DNA from 20 domesticated Formosan Sambar deer (Cervus unicolor swinhoei). All loci were polymorphic, with 10-19 alleles per locus. The average observed heterozygosity across loci and samples was 0.310, ranging from 0 to 0.750 at each locus. All loci but one, CU18, deviated from Hardy-Weinberg equilibrium due to excessive homozygosity in these domesticated broodstocks, reflecting inbreeding. These microsatellite loci will be useful, not only for assessment of population structure and genetic variability, but also for conservation of wild deer populations in Taiwan.

Loss of speech after living-related donor liver transplantation: detection of the lesion by diffusion tensor image

INTRODUCTION

Loss of speech after living-related liver transplantation is uncommon. Either immunosuppressive agents, related sequelae, or a neurological event may cause it.

CASE REPORT

A 46-year-old man developed dysarthria and dysphagia on the 10th day after living-related donor liver transplantation for alcoholic cirrhosis with Child-Pugh class C. Brain magnetic resonance images and electroencephalograms could not detect any lesion, but the diffusion tensor image showed a subacute lacunar infarction at right midbrain. The patient's speech improved 1 month after rehabilitation.

CONCLUSIONS

Some unexpected neurological events, such as loss of speech, may occur after liver transplantation. The differential diagnosis becomes very important before active treatment. Magnetic resonance imaging supplemented with diffusion tensor imaging is an effective imaging study in establishing the diagnosis.

Spontaneous and field-induced mesomorphism of a silyl-terminated bent-core liquid crystal as determined from second-harmonic generation and resonant X-ray scattering

The polarity and structure of the phases of a liquid crystal constituted by thiophene-based bent-core molecules is investigated by means of optical second-harmonic generation (SHG), and resonant and conventional X-ray diffraction. The material studied is representative of a wide family of mesogens that contain silyl groups at the ends of the chains. These bulky terminal groups have been reported to give rise to smectic phases showing ferroelectric switching. However, the analysis of the SHG signal before and after application of electric fields has allowed us to establish unambiguously that the reported ferroelectricity is not intrinsic to the material but stabilized by the cell substrates once an electric field has been applied. In addition, the results obtained from resonant X-ray diffraction indicate that virgin samples have antiferroelectric undulated synclinic smectic structures.

DSPP contains an IRES element responsible for the translation of dentin phosphophoryn

The major phosphoprotein in dentin is the aspartic acid and serine-rich protein called dentin phosphophoryn (DPP). DPP appears to be synthesized as a part of a larger compound protein, dentin sialophosphoprotein (DSPP). DSPP has never been isolated or detected in dentin extracts. It is now evident that DSPP is a chimeric protein composed of 3 parts: dentin sialoprotein (DSP), DPP, and dentin glycoprotein (DGP). Previous reports have suggested that the BMP1 protease is responsible for processing DSPP. However, unequal amounts of these products are present in the dentin matrix. Here, we provide evidence for an internal ribosome entry site in the DSPP gene that directs the synthesis of DPP. This mechanism would account for unequal amounts of intracellular DSP and DPP. The internal ribosomal entry site (IRES) activity varied in different cell types, suggesting the presence of additional regulatory elements during the translational regulation of DPP. Further, we provide evidence that DPP is transported to the extracellular matrix (ECM) through exosomes. Using tissue recombination and lentivirus-mediated gain-of-function approaches, we also demonstrate that DPP is essential for the formation of well-defined tooth structures with mineralized dentin matrix.

First Report of Chrysoporthe deuterocubensis Causing Canker on Syzygium samarangense in Taiwan

Wax apple (Syzygium samarangense Merr. & Perry, syn. Eugenia javanica Lam.) belongs to the Myrtaceae family is an important economical tree fruit in Taiwan. The total production acreage of wax apple was 5,266 ha in which more than 77% were located in Pingtung County, southern Taiwan, in 2012. Since the winter of 2010, symptoms of withering leaves and cracking branches on wax apple trees were observed in some orchards in Nanjhou and Linbian Townships, Pingtung County. Diseased trees declined gradually and resulted in reduced fruit production. On the bark of diseased twigs and branches, black conidiamata with yellowish orange conidia were usually observed. For diagnosis, tissues from symptomatic branches were excised, surface sterilized with 0.5% sodium hypochlorite, and placed on 2% water agar in petri dishes. A total of four identical fungal isolates were obtained and maintained on potato dextrose agar (PDA). To fulfill Koch's postulates, three twigs of a wax apple tree were wounded with scalpel and inoculated with each of the four isolates, one tree per isolate. A 7-day-old hyphal mat (about 7 × 18 mm) of each fungal isolate was attached on the wound, wrapped with a wet absorbent cotton and Parafilm, and then covered with a layer of aluminum foil. For the control, the twigs of a wax apple tree were inoculated with PDA plugs. The pathogenicity test was repeated once. After 30 days, withering leaves and cracking twigs were observed on inoculated twigs and the same pathogen was reisolated. Conversely, all of the non-inoculated plants remained healthy. Identification of the pathogen was conducted using its morphological, physiological, and molecular characteristics. On malt extract agar, the colony was floccose and white with hazel hues. The optimal temperature for the mycelial growth was 30°C. Conidia were hyaline, and oblong, with the average size of 4.7 ± 0.6 × 2.7 ± 0.2 μm (100 conidia). Ascostromata were semi-immersed in the bark with fusoid asci, eight ascospores per ascus. Ascospores were hyaline, 2-celled, and tapered in both ends, with the average length of 6.8 ± 0.7 × 2.4 ± 0.3 μm (100 ascospores). For molecular identification, the internal transcribed spacer (ITS) of ribosomal DNA and β-tubulin genes was amplified using the ITS1/ITS4 (3), Bt1a/Bt1b, and Bt2a/Bt2b (1) primer pairs. The gene sequences were deposited in GenBank (Accessions KC792616, KC792617, KC792618, and KC792619 for the ITS region; KC792620, KC792621, KC792622, and KC792623 for Bt1 region, and KC812732, KC812733, KC812734, and KC812735 for Bt2 region) and showed 99 to 100% identity to the Chrysoporthe deuterocubensis isolate CMW12745 (DQ368764 for ITS region; GQ290183 for Bt1 region, and DQ368781 for Bt2 region). In addition, the Bt1 region of the β-tubulin gene consisted of two restriction sites for AvaI and one restriction site for HindIII. This is identical to the description of C. deuterocubensis, a cryptic species in C. cubensis, by Van Der Merwe et al. (2). According to these results, the pathogen was identified as C. deuterocubensis Gryzenh. & M. J. Wingf. To the best of our knowledge, this is the first report of canker disease caused by C. deuterocubensis on S. samarangense in Taiwan. References: (1) N. L. Glass and G. C. Donaldson. Appl. Environ. Microbiol. 61:1323, 1995. (2) N. A. Van Der Merwe et al. Fungal Biol. 114:966, 2010. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

Brucellosis in a renal transplant recipient

Brucellosis is one of the most common systemic zoonotic diseases transmitted by consumption of unpasteurized dairy products or by occupational contact with infected animals. Brucellosis is rare in renal transplant recipients. Only 3 cases have been reported in the literature. We report a case of brucellosis with hematologic and hepatobiliary complications in a patient 3 years after renal transplantation. The mean time from transplantation to the diagnosis of brucellosis in these 4 reported patients was 5.1 years (range 17 months to 13 years). All patients had fever and constitutional symptoms, and all attained clinical cure after combination antibiotic therapy. Given the small number of patients, further study is needed to identify the characteristics of brucellosis in renal transplant recipients. Drug interactions and acute renal failure developed in our patient during antibiotic treatment. Therefore, we should monitor the levels of immunosuppressive agents frequently. Several studies have shown in vitro susceptibilities of Brucella melitensis to tigecycline. In our patient, fever finally subsided after tigecycline administration. The minimum inhibitory concentration of tigecycline using Etest was 0.094 μg/mL. Tigecycline may be a potential option for treatment of brucellosis in the setting of transplantation.

Assessing patient safety culture in hospitals across countries

OBJECTIVE

It is believed that in order to reduce the number of adverse events, hospitals have to stimulate a more open culture and reflective attitude towards errors and patient safety. The objective is to examine similarities and differences in hospital patient safety culture in three countries: the Netherlands, the USA and Taiwan.

DESIGN

This is a cross-sectional survey study across three countries. A questionnaire, the Hospital Survey on Patient Safety Culture (Hospital SOPS), was disseminated nationwide in the Netherlands, the USA and Taiwan.

SETTING

The study was conducted in 45 hospitals in the Netherlands, 622 in the USA and 74 in Taiwan.

PARTICIPANTS

A total of 3779 professionals from the participating hospitals in the Netherlands, 196 462 from the USA and 10 146 from Taiwan participated in the study.

MAIN OUTCOME MEASURES

The main outcome measures of the study were 12 dimensions of patient safety culture, e.g. Teamwork, Organizational learning, Communication openness.

RESULTS

Most hospitals in all three countries have high scores on teamwork within units. The area with a high potential for improvement in all three countries is Handoffs and transitions. Differences between countries exist on the following dimensions: Non-punitive response to error, Feedback and communication about error, Communication openness, Management support for patient safety and Organizational learning--continuous improvement. On the whole, US respondents were more positive about the safety culture in their hospitals than Dutch and Taiwanese respondents. Nevertheless, there are even larger differences between hospitals within a country.

CONCLUSIONS

Comparison of patient safety culture data has shown similarities and differences within and between countries. All three countries can improve areas of their patient safety culture. Countries can identify and share best practices and learn from each other.

High-resolution calorimetric study of phase transitions in chiral smectic-C liquid crystalline phases

We carried out an improved characterization of phase transitions among chiral smectic-C subphases observed for various antiferroelectric liquid crystals by precise heat capacity measurements. It was found that the phase transitions are intrinsically first order exhibiting a remarkable heat anomaly which involves little pretransitional thermal fluctuation and a finite thermal hysteresis. On the other hand, we also noticed that the critical point of the smectic-C(α)(*)-smectic-C* transition is induced by the destabilization of the smectic-C(α)(*) phase which couples with the fluctuation associated with the smectic-A-smectic-C(α)(*) phase transition.

A fractal dimensional approach to successful evaluation of apical healing

AIM

To evaluate whether the initial healing of apical radiolucencies 1 year after root canal treatment could be quantitatively identified by the change in fractal dimension (FD) values for the eventually completely healed cases.

METHODOLOGY

Twenty-six patients with successful root canal treatment were recruited. All teeth were associated with complete healing either before or at 1 year following treatment (six of 26) or still undergoing healing at 1 year after treatment but completely healed thereafter (20 of 26). Two radiographs were selected for the same patient, one taken before treatment and the other taken 1 year after treatment. Eight regions of interests (ROIs) were selected from each radiograph, two as the experimental group located close to the infected root apex, two as the control group in the healthy bone and the other four in the healthy bone ensuring the image quality.

RESULTS

Based on the FD values of the four ROIs in the healthy bone, the two radiographs were confirmed to have been taken with similar projection angles and exposure. The FD values were shown to significantly increase (P = 0.006) and decrease (P = 0.000) around the root apex and the neighbouring region of the apical lesion, respectively.

CONCLUSION

Changes in fractal dimension values may serve as a necessary condition to quantitatively indicate the initial healing status 1 year after root canal treatment.