Facial erythema in patients with atopic dermatitis treated with Dupilumab - a descriptive study of morphology and Aetiology.

BACKGROUND: The development of dermatitis on face and neck, which was not described in phase 3 clinical trials, has been reported in the literature in patients treated with dupilumab. Little is known regarding the causes or defining features of the facial dermatitis. OBJECTIVES: We conducted surveys of consecutive patients with AD on dupilumab to describe its clinical features, morphology and aetiology. METHODS: A multi-centre prospective cohort study was conducted from 1 January 2020, to 31 December 31 2020. A total of 162 patients under dupilumab treatment were asked to complete a questionnaire and patients were evaluated by dermatologists. RESULTS: Of all 162 patients, 137 (84.6%) patients reported pre-existing facial dermatitis prior to dupilumab therapy. One hundred and twenty-one (88.3%) patients with pre-existing facial dermatitis reported improvement of their facial dermatitis with dupilumab therapy, nine (6.6%) patients reported no change after the treatment and seven (4.3%) patients of them got worse after the treatment (exacerbation group). Of 25 patients who reported no pre-existing active facial dermatitis, six (24%) patients reported new-onset facial erythema after the starting dupilumab therapy (new-onset group). A large proportion of the patients in both the exacerbation (86%) and new-onset groups (67%) had a history of facial TCS use. Both groups showed similar clinical manifestations and distribution with few differences. CONCLUSIONS: The vast majority of patients treated with dupilumab in academic institutions from Korea and the United States experienced improvement in their facial dermatitis with dupilumab therapy. A small proportion of patients had new onset and exacerbation. Although the mechanisms of this adverse event remain unclear, steroid withdrawal should be considered as a diagnosis of the erythema in some patients.

[MUC4 Silencing Inhibits TGF-ß1-induced Epithelial-mesenchymal Transition VIA the ERK1/2 Pathway in Human Airway Epithelial NCI-H292 Cells].

MUC4 is a predominant membrane-tethered mucin lubricating and protecting the epithelial surface and playing various biological roles in the renewal and differentiation of epithelial cells, cell signaling, cell adhesion, and carcinogenesis. Interestingly, recent studies have demonstrated that MUC4 expression regulates the epithelial-mesenchymal transition (EMT) of cancer cells in ovarian, pancreatic, and lung cancer. However, the effects of MUC4 expression on EMT in human airway epithelial cells are not yet well known. Here, we describe the effects of transforming growth factor beta 1 (TGF-ß1)-induced MUC4 expression on EMT and evaluate its downstream signaling pathway in human airway epithelial cells. In human airway epithelial NCI-H292 cells, exposure to TGF-ß1 induced expression of MUC4, CDH2, VIM and SNAI1 genes and encoded by them proteins, MUC4, N-cadherin, vimentin and Snail, and reduced the level of CDH1 and its product, E-cadherin. In MUC4-knockdown cells, TGF-ß1-induced expression levels of MUC4, CDH2, VIM and SNAI1 and corresponding proteins were suppressed, but CDH1 and E-cadherin levels were not. In addition, TGF-ß1-induced phosphorylation of extracellular signal regulated kinase 1/2 (ERK1/2) was suppressed, but that of Smad2/3, Akt, and p38 was not. The results of this study suggest that MUC4 silencing inhibits TGF-ß1 -induced EMT via the ERK1/2 pathway, and a possible role of MUC4 in the induction of EMT in human airway epithelial cells.

Randomly Hopping Majorana Fermions in the Diluted Kitaev System α-Ru_{0.8}Ir_{0.2}Cl_{3}.

dc and ac magnetic susceptibility, magnetization, specific heat, and Raman scattering measurements are combined to probe low-lying spin excitations in α-Ru_{1-x}Ir_{x}Cl_{3} (x≈0.2), which realizes a disordered spin liquid. At intermediate energies (ℏω>3 meV), Raman spectroscopy evidences linearly ω-dependent Majorana-like excitations, obeying Fermi statistics. This points to robustness of a Kitaev paramagnetic state under spin vacancies. At low energies below 3 meV, we observe power-law dependences and quantum-critical-like scalings of the thermodynamic quantities, implying the presence of a weakly divergent low-energy density of states. This scaling phenomenology is interpreted in terms of the random hoppings of Majorana fermions. Our results demonstrate an emergent hierarchy of spin excitations in a diluted Kitaev honeycomb system subject to spin vacancies and bond randomness.

Fipronil upregulates inflammatory cytokines and MUC5AC expression in human nasal epithelial cells.

BACKGROUND: Airway inflammation and excessive mucin production are pathophysiological characteristics of airway diseases. Fipronil, a pesticide, is being extensively used in agriculture and veterinary medicine worldwide. However, this compound impairs immune function in non-target organisms. The present study aimed to evaluate the effect of fipronil on pro-inflammatory cytokine and mucus production and signalling pathways in human primary nasal METHODOLOGY: The effect of fipronil on pro-inflammatory cytokine and MUC5AC expression and the signalling pathway of fipronil were investigated using real-time PCR, enzyme immunoassays, immunofluorescence, and immunoblot analysis with specific inhibitors and small interfering RNA. RESULTS: Fipronil treatment increased pro-inflammatory cytokine interleukin (IL)-1beta, IL-6, IL-8, and MUC5AC expression in human primary nasal epithelial cells. It also induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) mitogenactivated protein kinase (MAPK), p38 MAPK, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB). MAPK and NF-kB inhibitor treatment significantly inhibited increases in IL-1beta, IL-6, IL-8, and MUC5AC expression. Ex vivo data confirmed that fipronil-induced MUC5AC expression occurs through ERK1/2, p38, and NF-kB signalling pathways in nasal inferior turbinate tissue. CONCLUSIONS: Fipronil induced pro-inflammatory cytokine IL-1beta, IL-6, IL-8, and MUC5AC expression via ERK1/2 MAPK, p38 MAPK, and NF-kB in human primary nasal epithelial cells.

Exotic Low-Energy Excitations Emergent in the Random Kitaev Magnet Cu_{2}IrO_{3}.

We report on magnetization M(H), dc and ac magnetic susceptibility χ(T), specific heat C_{m}(T) and muon spin relaxation (µSR) measurements of the Kitaev honeycomb iridate Cu_{2}IrO_{3} with quenched disorder. In spite of the chemical disorders, we find no indication of spin glass down to 260 mK from the C_{m}(T) and µSR data. Furthermore, a persistent spin dynamics observed by the zero-field muon spin relaxation evidences an absence of static magnetism. The remarkable observation is a scaling relation of χ[H,T] and M[H,T] in H/T with the scaling exponent α=0.26-0.28, expected from bond randomness. However, C_{m}[H,T]/T disobeys the predicted universal scaling law, pointing towards the presence of additional low-lying excitations on the background of bond-disordered spin liquid. Our results signify a many-faceted impact of quenched disorder in a Kitaev spin system due to its peculiar bond character.

Identification of transfusion-transmitted hepatitis A through postdonation information in Korea: results of an HAV lookback (2007-2012).

BACKGROUND AND OBJECTIVES: Despite safety measures to minimize the risk of transfusion-transmitted infections, a residual risk remains. To trace and review some such cases, we ask donors to notify the blood centre if they are diagnosed with an infection after they donate blood. MATERIALS AND METHODS: We analysed all data on postdonation cases of hepatitis A reported between 2007 and 2012. Archived specimens from these donors were tested for hepatitis A virus (HAV) using anti-HAV IgM/IgG and HAV-PCR as markers. If any of the test results were positive, we reviewed the medical records of the recipients and, if necessary, tested them for hepatitis A. RESULTS: Fifteen blood donors notified the blood centres of having been diagnosed with hepatitis A after donation. All archived samples except for one were HAV-PCR-positive and anti-HAV IgM/IgG-negative. Of the donated components, four RBCs and 14 FFPs had not been transfused to patients and were recalled. Among 26 recipients of the implicated components, fourteen were still alive when they were notified. Two patients showed clinical symptoms of hepatitis A and had positive results with anti-HAV IgM. CONCLUSION: Transfusion-transmitted hepatitis A is rare but exists. To reduce the risk, donors should be told to notify the blood centre if they are diagnosed with blood-borne diseases after they donate blood. Physicians should consider the possibility of transfusion-transmitted hepatitis A if a transfused patient has hepatitis A but no history of travel or route of faecal-oral infection.

Carotid ultrasound measurements for assessing fluid responsiveness in spontaneously breathing patients: corrected flow time and respirophasic variation in blood flow peak velocity.

BACKGROUND: This study evaluated the ability of two Doppler ultrasound-derived parameters, the carotid corrected flow time (FTc) and respirophasic variation in carotid artery blood flow peak velocity (ΔVpeak), to predict fluid responsiveness in spontaneously breathing patients. METHODS: A total of 53 spontaneously breathing patients were studied before anaesthetic induction for neurosurgery. Carotid FTc, ΔVpeak, and haemodynamic data were measured before and after administration of 6 ml kg-1 colloid. Fluid responsiveness was defined as a 15% or more increase in stroke volume index as assessed by transthoracic echocardiography after the fluid challenge. RESULTS: Twenty-two (42%) patients were fluid responders. The areas under the receiver operating characteristic curves for FTc and ΔVpeak were 0.842 [95% confidence interval (CI) 0.735-0.948, P<0.001] and 0.818 (95% CI: 0.701-0.935, P<0.001), respectively. The optimal cut-off values of FTc and ΔVpeak for fluid responsiveness were 349.4 ms (sensitivity of 72.7%; specificity of 83.9%) and 9.1% (sensitivity of 72.7%; specificity of 87.1%), respectively. The grey zone for FTc was 346.9-361.0 ms and included 28% of the patients, and the grey zone for ΔVpeak was 6.5-10.2% and included 50% of the patients. CONCLUSIONS: Using Doppler ultrasound-derived parameters measured at the carotid artery, FTc predicted fluid responsiveness in spontaneously breathing patients better than ΔVpeak. However, further studies are warranted before these parameters are recommended for clinical use. CLINICAL TRIAL REGISTRATION: NCT 02843477.

Relationships between 25(OH)D concentration, sarcopenia and HOMA-IR in postmenopausal Korean women.

OBJECTIVE: Sarcopenia and insulin resistance are common co-morbidities in the elderly and are known to be associated with vitamin D deficiency. However, no previous studies have investigated interactions between all three of these factors. We aimed to investigate the relationship between 25-hydroxyvitamin D concentration, sarcopenia, and insulin resistance in postmenopausal Korean women. METHODS: This study used data from the Korea National Health and Nutrition Examination Survey 2008-2011. Participants were 3744 postmenopausal Korean women. Sarcopenia was defined as appendicular skeletal muscle mass divided by body weight >1 standard deviation below the mean for women aged 20-40 years. The serum 25-hydroxyvitamin D and fasting insulin levels were measured, and insulin resistance was calculated using the formula: fasting plasma glucose (mg/dl) × fasting insulin (mIU/l)/405. RESULTS: We found a strong inverse association between 25-hydroxyvitamin D concentration and sarcopenia in postmenopausal Korean women (p = 0.0009). There was also a significant association between sarcopenia and insulin resistance, independent of vitamin D and obesity status (p < 0.0001). However, there was no significant association between 25-hydroxyvitamin D concentration and insulin resistance. In the subgroup analysis, insulin resistance was found to be determined by sarcopenic rather than vitamin D status. CONCLUSIONS: Sarcopenia was associated with both insulin resistance and 25-hydroxyvitamin D concentration in postmenopausal Korean women, regardless of obesity status. However, 25-hydroxyvitamin D concentration was not associated with insulin resistance. Sarcopenia is therefore of greater clinical importance due to its close relationship with insulin resistance.

Gender differences in limited duty time for lower limb injury.

Background: Among active-duty military personnel, lower limb musculoskeletal injuries and related conditions (injuries) frequently arise as unintended consequences of physical training. These injuries are particularly common among women. The practical impact of such injuries on temporary military occupational disability has not been estimated with precision on a large scale. Aims: To determine the proportion of service time compromised by limited duty days attributable to lower limb injuries, characterize the time affected by these limitations in terms of specific lower limb region and compare the limited duty time between male and female soldiers. Methods: Administrative data and individual limited duty assignments (profiles) were obtained for active-duty US Army personnel who served in 2014. Lower limb injury-related profiles were used to calculate the percent of person-time requiring duty limitations by gender and body region. Results: The study group was 568 753 soldiers of whom 14% were women. Nearly 13% of service days for active-duty US Army soldiers required limited duty for lower limb injuries during 2014. Knee injuries were responsible for 45% of those days. Within integrated military occupations, female soldiers experienced 27-57% more time on limited duty for lower limb injuries compared with men. Conclusions: The substantial amount of limited duty for lower limb musculoskeletal injuries among soldiers highlights the need for improvement in training-related injury screening, prevention and timely treatment with particular attention to knee injuries. The excessive impact of lower limb injuries on female soldiers' occupational functions should be a surveillance priority in the current environment of expanding gender-integrated training.

Associations of dietary calcium intake with metabolic syndrome and bone mineral density among the Korean population: KNHANES 2008-2011.

Excessive amount of calcium intake increased risk for metabolic syndrome in men. However, modest amount decreased the risk of metabolic syndrome and osteoporosis in postmenopausal women. Modest amount of calcium also increased bone mineral density (BMD) in both men and postmenopausal women. INTRODUCTION: The present study aimed to evaluate the associations of dietary calcium intake with metabolic syndrome and bone mineral density (BMD) in Korean men and women, especially postmenopausal women. METHODS: The study was performed using data from the Korean National Health and Nutrition Examination Survey (2008-2011) and included 14,705 participants (5953 men, 4258 premenopausal women, and 4494 postmenopausal women). Clinical and other objective characteristics, presence of metabolic syndrome, and the BMD of the femur neck and lumbar spine were evaluated according to dietary calcium intake. RESULTS: There was a higher tendency for metabolic syndrome in men with a dietary calcium intake of >1200 mg/day than with ≤400 mg of calcium intake; >400 and ≤800 mg of calcium intake was helpful for postmenopausal women to decrease risk for metabolic syndrome. Overall, the group with calcium intake >400 and ≤800 mg daily had significantly increased BMD in both femoral neck and lumbar spine from both men and postmenopausal women. From both femoral neck and lumbar spine, the prevalence of osteoporosis in postmenopausal women significantly decreased in the group whose calcium intake was >400 and ≤800 mg daily. CONCLUSION: Excessive dietary calcium may increase the prevalence of metabolic syndrome in men. For postmenopausal women, calcium intake does not increase the risk of metabolic syndrome, but modest amount decreases the risk. It may increase the BMD in men and postmenopausal women, and also reduce the prevalence of both osteoporosis and metabolic syndrome in postmenopausal women.

Effect of caudal block using different volumes of local anaesthetic on optic nerve sheath diameter in children: a prospective, randomized trial.

BACKGROUND: Caudal block is commonly administered for postoperative analgesia in children. Although caudal block with 1.5 ml kg -1 local anaesthetic has been reported to reduce cerebral oxygenation in infants, the effect of caudal block on intracranial pressure (ICP) in children has not been well investigated. Optic nerve sheath diameter (ONSD) correlates with degree of ICP. This study aimed to estimate the effects of caudal block on ICP according to volume of local anaesthetic using ultrasonographic measurement of ONSD in children. METHODS: Eighty patients, 6- to 48-months-old, were randomly allocated to the high-volume (HV) or low-volume (LV) groups for caudal block with ropivacaine 0.15%, 1.5 ml kg -1 or 1.0 ml kg -1 , respectively. Measurement of ONSD was performed before (T0), immediately after (T1), and 10 min (T2) and 30 min (T3) after caudal block. RESULTS: The two groups exhibited significant differences in ONSD according to time ( P Group x Time =0.003). The HV group exhibited significantly greater changes in ONSD from T0 to T2 and T3 than the LV group. However, in both groups, ONSDs at T1, T2 and T3 were significantly greater compared with those at T0, with the highest values at T2. CONCLUSIONS: Caudal block with a high volume of local anaesthetic can cause a greater increase in ICP than caudal block with a low volume of local anaesthetic. However, caudal block with 1.0 ml kg -1 of local anaesthetic can also result in a significant increase in ICP. CLINICAL TRIAL REGISTRATION: NCT02768493.

Improved methods for evaluating pre-clinical and histological effects of subcutaneous fat reduction using high-intensity focused ultrasound in a porcine model.

BACKGROUND: Non-invasive body sculpting procedures are becoming increasingly popular. High-intensity focused ultrasound (HIFU) treatment is a non-surgical fat reduction procedure that permanently destroys unwanted abdominal fat. Despite its increasing popularity, evaluation methods for the procedure have not yet been fully developed. AIMS: The objective of this study was to develop evaluation methods for HIFU for non-surgical, permanent fat reduction in the anterior abdomen using a porcine model. METHODS: The abdomens of female pigs (Sus scrofa, n = 7) were treated with a HIFU device (SCIZER™ , Classys Inc, Seoul, Korea). We examined treatment effects using photography, ultrasound, gross and microscopic pathology, and serum lipid and liver function level analysis, carbon tracer test, and histological examination in order to determine the mechanism of action, efficacy, and safety of the procedure. RESULTS: HIFU treatment effectively reduced abdominal fat in a porcine model; it accurately treated the target subcutaneous fat layer and the subcutaneous fat was reduced effectively via ultrasonic measurement after HIFU treatment. On histological staining (H&E, toluidine blue, oil red O and immunohistochemistry), we found that subcutaneous fat reduction occurred effectively via accurate treatment of the targeted subcutaneous fat layer. On hematological assay, there were changes within normal range, and values remained stable after 48 h. Via carbon tracer test, the migration of activated macrophages was identified within the axillary lymph node (LN). PPAR-delta, a protein defined by immunohistochemistry staining, was overexpressed in the early stage on days 1 and 7, but a gradual decreasing pattern was confirmed. CONCLUSION: We successfully used a HIFU device for body contouring and fat reduction in a pre-clinical study. These results provide that the essential clues toward the effective evaluation, guiding selection of the appropriate diagnostic investigations.

Morphometric analysis of the maxillary root apex positions according to crowding severity.

OBJECTIVES: To determine differences in arch forms derived from the root apices locations between individuals with <2 mm maxillary crowding and controls. SETTING AND SAMPLE POPULATION: The Department of Orthodontics, Pusan National University. Cone-beam computed tomography (CBCT) images of 102 patients in the control group and 95 patients in the crowding group. MATERIALS AND METHODS: X, Y and Z coordinates of the tip of the crowns and the apex of the root of the maxillary teeth (except second molars) were determined on the CBCT images. The acquired three-dimensional (3D) coordinates were converted into two-dimensional (2D) coordinates via projection on the palatal plane, and the Procrustes analysis was employed to process the converted 2D coordinates. The mean shape of the arch form derived from the location of the tip of the crowns and the apex of the root was compared between groups using the statistical shape analysis. RESULTS: There was a statistically significant difference (P = .046) between the groups for the mean shape of the root apex arch form, but the difference was small and clinically irrelevant as it is minor compared to the degree of crowding. CONCLUSIONS: Maxillary arch from at the level of the maxillary apices only shows minor differences between crowded and non-crowded dentitions.

The effect of prolonged breast-feeding on the development of postmenopausal osteoporosis in population with insufficient calcium intake and vitamin D level.

UNLABELLED: Breast-feeding affects bone metabolism and calcium homeostasis, and prolonged breast-feeding may influence the development of postmenopausal osteoporosis, particularly in highly susceptible populations. The study determined that breast-feeding may be a risk factor for postmenopausal osteoporosis, especially in people with low calcium intakes and vitamin D deficiencies. INTRODUCTION: The purpose of this study was to determine whether breast-feeding is a risk factor in the development of postmenopausal osteoporosis, especially in highly susceptible population. METHODS: The study was performed using data from the 2010 to 2011 Korea National Health and Nutrition Examination Survey, and it included 1231 postmenopausal women who were aged between 45 and 70 years. Osteoporosis was defined using the World Health Organization's T-score criteria, namely, a T-score of ≤-2.5 at the femoral neck or the lumbar spine. The patients' ages, body mass indexes, daily calcium intakes, serum vitamin D levels, exercise levels, smoking histories, and reproductive factors relating to menarche, menopause, delivery, breast-feeding, hormone treatment, and oral contraceptive use were evaluated. Comparisons between the osteoporosis and non-osteoporosis groups were undertaken using Student's t test and the chi-square test, and logistic regression models were built. RESULTS: A significant increase in the risk of osteoporosis was apparent in postmenopausal women with prolonged breast-feeding histories (≥24 months) (model 1: odds ratio [OR] = 2.489; 95 % confidence interval [CI] = 1.111 to 5.578, p = 0.027; model 2: OR = 2.503; 95 % CI = 1.118 to 5.602, p = 0.026; model 3: OR = 2.825; 95 % CI = 1.056 to 7.56, p = 0.039), particularly in those with inadequate serum vitamin D levels and calcium intakes (<800 mg/day). CONCLUSIONS: Breast-feeding seems to increase the risk of postmenopausal osteoporosis; however, its impact may not be definitive in women with sufficient vitamin D levels and calcium intakes. Therefore, sufficient calcium intakes and adequate vitamin D levels may be important to prevent osteoporosis in postmenopausal women that is derived from breast-feeding.

An effective diagnostic strategy for accurate detection of RhD variants including Asian DEL type in apparently RhD-negative blood donors in Korea.

BACKGROUND AND OBJECTIVES: The purpose of this study was to provide an effective RHD genotyping strategy for the East Asian blood donors. MATERIAL AND METHODS: RhD phenotyping, weak D testing and RhCE phenotyping were performed on 110 samples from members of the RhD-negative club, private organization composed of RhD-negative blood donors, in the GwangJu-Chonnam region of Korea. The RHD promoter, intron 4, and exons 7 and 10 were analysed by real-time PCR. Two nucleotide changes (c.1227 G>A, and c.1222 T>C) in exon 9 were analysed by sequencing. RESULTS: Of 110 RhD-negative club members, 79 (71·8%) showed complete deletion of the RHD gene, 10 (9·1%) showed results consistent with RHD-CE-D hybrid, and 21 (19·1%) showed amplification of RHD promoter, intron 4, and exons 7 and 10. Of the latter group, 16 (14·5%) were in the DEL blood group including c.1227 G>A (N = 14) and c.1222 T>C (N = 2), 2 (1·8%) were weak D, 1(0·9%) was partial D, and 2 (1·8%) were undetermined. The RhD-negative phenotype samples consisted of 58 C-E-c+e+, 19 C-E+c+e+, 3 C-E+c+e-, 21 C+E-c+e-, 6 C+E-c+e+ and 3 C+E-c-e + . Notably, all 58 samples with the C-E-c+e+ phenotype were revealed to have complete deletion of the RHD gene. The C-E-c+e+ phenotype showed 100% positive predictive value for detecting D-negative cases. CONCLUSIONS: RHD genotyping is not required in half of D-negative cases. We suggest here an effective RHD genotyping strategy for accurate detection of RhD variants in apparently RhD-negative blood donors in East Asia.

Step-down vs. step-up noxious stimulation: differential effects on pain perception and patterns of brain activation.

BACKGROUND: We hypothesize that pain and brain responses are affected by changes in the presentation sequence of noxious stimuli that are, overall, identical in intensity and duration. METHODS: During functional magnetic resonance imaging (fMRI) scanning, 21 participants experienced three patterns of noxious stimulation: Up-type (step-up noxious stimulation, 15 s), Down-type (step-down noxious stimulation, 15 s), and Down-up-type (decreasing and increasing pattern of noxious stimulation, 15 s). The total intensity and duration of the three noxious stimulation patterns were identical, but the stimulation sequences were different. RESULTS: Pain and unpleasantness ratings in the Down- and Down-up-type noxious stimulations were lower than in the Up-type noxious stimulation. The left prefrontal cortex [(PFC, BA (Brodmann area) 10, (-45, 50, 1)] was more highly activated in the Down- and Down-up-type noxious stimulations than in the Up-type noxious stimulation. The S1, S2, insula, bilateral PFC (BA 46), and midcingulate cortex were more highly activated in the Up-type noxious stimulation than in the Down-type noxious stimulation. PFC BA 10 was located at an inferior level compared to the bilateral PFC BA 46 (Z axis = 1 for BA 10, compared to 22 and 25 for the right and left BA 46, respectively). When cortisol level was increased, the left hippocampal cortex, along with the left parahippocampal cortex, was greatly activated for the Up-type noxious stimulation. CONCLUSION: When pain cannot be avoided in clinical practice, noxious stimuli should be applied to patients in a step-down pattern that delivers the most intense pain first and the least intense pain last.

Effects of postmortem temperature on the physicochemical characteristics of prerigor Pekin duck breast muscles.

The effects of postmortem (PM) temperature on prerigor Pekin duck breast muscle quality were assessed. Breast meat was obtained from 90 ducks within 15 min PM and then divided into 3 storage temperature groups at 0, 15, and 30°C for 24 h PM. Results revealed that the meat stored at 0°C had a higher pH value than that stored at 30°C. The R-value tended to increase between 15 min, 2 h, and 24 h PM, whereas the water-holding capacity decreased significantly (P < 0.05) with increasing storage time. The drip loss of treatment in meat stored at 30°C was higher than in those stored at 0 and 15°C. As storage periods increased, cooking loss of meat stored at each temperature increased significantly (P < 0.05) at 2 h, but storage temperature does not affect cooking loss of duck breast muscle. The shear force of breast meat at 24 h PM had the lowest value, but meat stored at 30°C increased at 2 h and decreased at 24 h PM. Meat stored at 15°C showed a longer sarcomere length than meat stored at 0 and 30°C. The rate of muscle shortening was high during the 2 h PM for meat at the 3 temperatures. It is concluded that the different temperatures in the range of 0 to 30°C affected the muscle shortening or meat quality of the duck breast meat.

Bacterial invasion and persistence: critical events in the pathogenesis of periodontitis?

Periodontitis is chronic inflammation of the periodontium caused by the host's inflammatory response to plaque biofilm, which destroys tooth-supporting soft and hard tissues. Periodontitis is a complex disease that involves interactions among three main features - microbial challenge, the host immune response, and environmental and genetic risk factors - in its pathogenesis. Although periodontitis has been regarded as the result of hyperimmune or hyperinflammatory responses to plaque bacteria, recent studies indicate that periodontal pathogens are rather poor activators and/or suppressors of the host immune response. This raises the question of how periodontal pathogens cause inflammation. To resolve this issue, in the present review we propose that bacterial invasion into gingival tissue is a key event in the initiation of periodontitis and that the persistence of these bacteria within host tissue results in chronic inflammation. In support of this hypothesis, we present the ways in which microbial, environmental and genetic risk factors contribute to bacterial invasion. It is hoped that the current model will instigate active discussion and new research to complete the puzzle of this complex disease process.