Progressive nodule-like lesions on bilateral lower limbs.

Pancreatic panniculitis is a rare disease characterized by subcutaneous fat necrosis. It could be the result of an associated pancreatic tumor. Herein, we reported a 63-year-old man who presented with progressive bilateral lower limb edema accompanied with nodule-like lesions for 1 month. His serum lipase was 3,927 U/L (normal, 0-160 U/L). Histopathology of the skin specimen revealed lobular panniculitis, favoring a diagnosis of pancreatic panniculitis. Abdominal computed tomography (CT) scan with contrast showed a huge mass in his left upper quadrant. Endoscopic ultrasound showed a mixed echoic tumor, measuring 11.9 × 7.8 cm in dimensions, originating from the pancreatic tail. Biopsy performed via an endoscopic ultrasound showed a poorly differentiated acinar cell carcinoma. Because of the unresectable status of the tumor, the patient underwent chemotherapy with paclitaxel and gemcitabine. After chemotherapy, his skin lesions improved progressively. It is important to treat pancreatic panniculitis with its underlying pancreatic disease.

Clarification of recombinant proteins from high cell density mammalian cell culture systems using new improved depth filters.

Increasingly high cell density, high product titer cell cultures containing mammalian cells are being used for the production of recombinant proteins. These high productivity cultures are placing a larger burden on traditional downstream clarification and purification operations due to higher product and impurity levels. Controlled flocculation and precipitation of mammalian cell culture suspensions by acidification or using polymeric flocculants have been employed to enhance clarification throughput and downstream filtration operations. While flocculation is quite effective in agglomerating cell debris and process related impurities such as (host cell) proteins and DNA, the resulting suspension is generally not easily separable solely using conventional depth filtration techniques. As a result, centrifugation is often used for clarification of cells and cell debris before filtration, which can limit process configurations and flexibility due to the investment and fixed nature of a centrifuge. To address this challenge, novel depth filter designs were designed which results in improved primary and secondary direct depth filtration of flocculated high cell density mammalian cell cultures systems feeds, thereby providing single-use clarification solution. A framework is presented here for optimizing the particle size distribution of the mammalian cell culture systems with the pore size distribution of the gradient depth filter using various pre-treatment conditions resulting in increased depth filter media utilization and improved clarification capacity. Feed conditions were optimized either by acidification or by polymer flocculation which resulted in the increased average feed particle-size and improvements in throughput with improved depth filters for several mammalian systems.

Repeating fast radio burst 20201124A originates from a magnetar/Be star binary.

Fast radio bursts (FRBs) are cosmic sources emitting millisecond-duration radio bursts. Although several hundreds FRBs have been discovered, their physical nature and central engine remain unclear. The variations of Faraday rotation measure and dispersion measure, due to local environment, are crucial clues to understanding their physical nature. The recent observations on the rotation measure of FRB 20201124A show a significant variation on a day time scale. Intriguingly, the oscillation of rotation measure supports that the local contribution can change sign, which indicates the magnetic field reversal along the line of sight. Here we present a physical model that explains observed characteristics of FRB 20201124A and proposes that repeating signal comes from a binary system containing a magnetar and a Be star with a decretion disk. When the magnetar approaches the periastron, the propagation of radio waves through the disk of the Be star naturally leads to the observed varying rotation measure, depolarization, large scattering timescale, and Faraday conversion. This study will prompt to search for FRB signals from Be/X-ray binaries.

Mental Health Youth Ambassador Programme for Anti-Stigma Among Secondary Students in Hong Kong: a Pilot Study.

OBJECTIVES: To evaluate the Mental Health Youth Ambassador Programme between 2016 and 2019 in terms of participants' improvement in attitudes towards individuals with depression or psychosis. METHODS: This anti-stigma programme was provided to secondary students (form 3 and above) and comprised three levels. Level 1 involved attending lectures about mental health; level 2 and level 3 involved social contact with persons-in-recovery. Students' attitudes towards those with depression and those with psychosis were assessed at baseline and after completion of each level of programme using the Chinese version of the Social Distance Scale. RESULTS: Only 25 students who were assessed at all four time points were included in analysis. The mean Social Distance Scale scores for attitudes towards depression and psychosis improved significantly across all time points. Specifically, significant improvement occurred after completion of level 2 and level 2 but not after completion of level 1. CONCLUSION: Social contact with people with mental illness (rather than attending lectures about mental health) contributed significantly to the improvement in students' attitude towards depression and psychosis. With the positive preliminary results, the Mental Health Youth Ambassador Programme should be extended to more students.

Increased programmed death-ligand-1 expression in human gastric epithelial cells in Helicobacter pylori infection.

B7-H1 [programmed death-ligand-1 (PD-L1)] is a B7-family member that binds to programmed death-1 (PD-1). Recently, deficiency of PD-L1 has been demonstrated to result in accelerated gastric epithelial cell damage in gastritis, and PD-L1 is suggested to play a critical role in regulating T cell homeostasis. Here, we aimed to gain more insight into gastric PD-L1 expression, regulation and function during Helicobacter pylori infection. PD-L1 expression in human gastric epithelial cells was analysed using Western blotting, quantitative polymerase chain reaction and fluorescence activated cell sorter analysis. Furthermore, co-culture experiments of human gastric epithelial cells with primary human T cells or Jurkat T cells were conducted. PD-L1 expression in primary human gastric epithelial cells was strongly enhanced by H. pylori infection and activated T cells, and augmented markedly by further stimulation with interferon-γ or tumour necrosis factor-α. Moreover, PD-L1 expression in gastric epithelial cells significantly induced apoptosis of T cells. Our results indicate that a novel bidirectional interaction between human gastric epithelial cells and lymphocytes modulates PD-L1 expression in human gastric epithelial cells, contributing to the unique immunological properties of the stomach.

High-redshift gamma-ray bursts: observational signatures of superconducting cosmic strings?

The high-redshift gamma-ray bursts (GRBs), GRBs 080913 and 090423, challenge the conventional GRB progenitor models by their short durations, typical for short GRBs, and their high energy releases, typical for long GRBs. Meanwhile, the GRB rate inferred from high-redshift GRBs also remarkably exceeds the prediction of the collapsar model, with an ordinary star formation history. We show that all these contradictions could be eliminated naturally, if we ascribe some high-redshift GRBs to electromagnetic bursts of superconducting cosmic strings. High-redshift GRBs could become a reasonable way to test the superconducting cosmic string model because the event rate of cosmic string bursts increases rapidly with increasing redshifts, whereas the collapsar rate decreases.

A rapid cosmic-ray increase in BC 3372-3371 from ancient buried tree rings in China.

Cosmic rays interact with the Earth's atmosphere to produce 14C, which can be absorbed by trees. Therefore, rapid increases of 14C in tree rings can be used to probe previous cosmic-ray events. By this method, three 14C rapidly increasing events have been found. Plausible causes of these events include large solar proton events, supernovae, or short gamma-ray bursts. However, due to the lack of measurements of 14C by year, the occurrence frequency of such 14C rapidly increasing events is poorly known. In addition, rapid increases may be hidden in the IntCal13 data with five-year resolution. Here we report the result of 14C measurements using an ancient buried tree during the period between BC 3388 and 3358. We found a rapid increase of about 9‰ in the 14C content from BC 3372 to BC 3371. We suggest that this event could originate from a large solar proton event.

Psychiatric Morbidity in Chinese Adults with Type 1 Diabetes in Hong Kong.

OBJECTIVES: To determine the prevalence of psychiatric morbidity and identify the correlates, as well as to evaluate the effectiveness of the Hospital Anxiety and Depression Scale and the 12-item General Health Questionnaire to screen for psychiatric morbidity in Chinese adults with type 1 diabetes. METHODS: Subjects were recruited from a local public diabetes specialist outpatient clinic from August 2013 to January 2014. Demographic and clinical factors were recorded. Psychiatric diagnosis was established using the Chinese-bilingual version of the Structured Clinical Interview for the DSM-IV Axis I disorders. Scores for the Hospital Anxiety and Depression Scale and the 12-item General Health Questionnaire were compared with the psychiatric diagnosis. RESULTS: Of the 136 patients, the point prevalence of overall psychiatric, depressive, and anxiety disorders was 39.7%, 23.5%, and 25.7%, respectively. Family history of mental illness, smoking status, history of mental illness, presence of social problems, perceived absence of confidant, presence of neuropathy and hyperlipidaemia, as well as higher level of glycosylated haemoglobin were found to be the associated factors. CONCLUSION: Psychiatric disorders were common in Chinese adults with type 1 diabetes. Finding out associated factors and using the Hospital Anxiety and Depression Scale and the 12-item General Health Questionnaire as a screening tool helped to identify patients in a diabetes clinic with psychiatric disorders.

Expression of proliferating cell nuclear antigen in luminal epithelium during the growth and regression of rat uterus.

Proliferating cell nuclear antigen (PCNA), a processivity factor of DNA synthesis, has often been used as a marker that reveals proliferating cells. However, it also plays a role other than in DNA replication. The aim of this study was to examine the relationship between the expression of PCNA and cell proliferation, and also its relation to cell death in the uterine epithelium under various hormonal conditions. Rats with regular estrous cycles were killed at various stages of the cycle, and their uteri were removed for the detection of PCNA and apoptosis by immunohistochemical and terminal deoxynucleotidyl transferase-mediated nick end-label staining respectively. There was an inverse relationship between the expression of PCNA and apoptosis in the uterine epithelium during the estrous cycle. From diestrus to proestrus, the expression of PCNA increased, and few apoptotic cells were detected in the luminal epithelium. However, at estrus, apoptosis occurred markedly, and the expression of PCNA disappeared. To study further the effects of estrogen on PCNA expression and cell growth in the uterus, rats were ovariectomized and then implanted s.c. with estrogen capsules 2 weeks later. In ovariectomized rats, only a few PCNA-positive cells were observed in the uterine epithelium. After estrogen treatment, PCNA was expressed strongly in the luminal and glandular epithelia. In these rats, the removal of estrogen capsules resulted in apoptotic death and surprisingly strong PCNA expression in the cells of luminal epithelium. Our results demonstrate that PCNA is expressed not only in the estrogen-stimulated uterine growth, but also in the processes of regression induced by the withdrawal of estrogen. Although the expression of PCNA has been reported to represent cell proliferation, our results implicate functions other than cell replication for PCNA in the uterus.

Expression of vascular endothelial growth factor in normal liver and hepatocellular carcinoma: an immunohistochemical study.

Angiogenesis is of vital importance during the development and progression of solid tumors. To examine the role of vascular endothelial growth factor (VEGF) in hepatocarcinogenesis, we evaluated the expression of peptide in normal human liver (n = 6) and in 36 cases of hepatocellular carcinoma (HCC). Immunoreactivity for VEGF was present in the extracellular matrix of the portal tracts in the normal and nontumor part of liver, but not in hepatocytes and bile duct epithelium. For HCC, variable amounts of VEGF were expressed in 13 cases (36.1%) of tumor cells. Using a logistic regression model, expression of VEGF was significantly associated with a higher proliferative index (P = .01) and sonographic portal vein thrombosis (P = .05). However, VEGF expression did not correlate with a biochemical liver profile, alpha-fetoprotein levels, histological grading, gender, or clinical stage of cirrhosis (P > 0.1, respectively). Log-rank test showed that evaluation of VEGF did not provide more prognostic information (P > .5) than that from tumor volume and portal vein thrombosis (P < .01, respectively). In addition, VEGF was always present in the fibrovascular stroma or pericellular matrix of HCC, although no strong relationship was observed with the expression of VEGF in tumor cells (P > .5). Our data suggested that expression of VEGF may characterize a progression toward higher proliferation in hepatocarcinogenesis in vivo. The relevance of VEGF existing in the extracellular matrix of the normal liver and HCC remains to be clarified.

University of Wisconsin solution extends lung preservation after prostaglandin E1 infusion.

University of Wisconsin (UW) solution has been demonstrated to enhance and extend the preservation of the hepatic, pancreatic, renal, and cardiac allografts. Prostaglandin E1 (PGE1), which has been used to produce pulmonary vasodilatation, has improved preservation in lung transplantation. Experiments were designed to evaluate their potential role in 24-h preservation of the allografts in lung transplantation. Thirty-six dogs underwent left lung transplantation. The donor lungs (n = 6 in each group) were flushed with UW solution (group 1 and 2) or modified Euro-Collins (EC) solution (group 3) after PGE1 infusion (500 micrograms). In group 1, donor lungs were transplanted immediately. Lung allografts of group 2 and 3 were cold stored (4 degrees C) in the same preservation solution for 24 h in the inflated state and then transplanted. The right pulmonary artery and right main bronchus were ligated 1 h after completion of the transplantation, forcing the recipient dogs to survive with the transplanted left lung. The recipients were ventilated with an inspired oxygen fraction of 0.4 and end-expiratory pressure 10 cm H2O. Two dogs died prematurely in group 3, whereas all dogs in group 1 and 2 survived the experimental period. The arterial oxygen tension and saturation and dynamic lung compliance were significantly higher in dogs of group 1 and 2. Transplanted lungs of group 1 and 2 had significantly lower pulmonary vascular resistance, alveolar-arterial oxygen difference, and wet/dry lung weight ratio. Histologically, pulmonary edema, congestion, sloughing of bronchial mucosa, and peribronchial and peripulmonary arterial hemorrhage were shown in lungs of group 3, but not in those of group 1 and 2. Airway mucosa and pulmonary vascular structure were well preserved in lungs of group 1 and 2. There was no significant difference between group 1 and 2 in lung functions, hemodynamics, or morphologic features. We concluded that PGE1 and UW solution could effectively extend lung preservation up to 24 h in this in vivo canine lung allotransplantation model.

Specific absorption rate ratio patterns of cylindrical ultrasound transducers for breast tumors.

The purpose of this paper is to examine the optimal driving frequency and to configure the ultrasound energy deposition schema for a various size and location of breast tissues when a portion or the entire cylindrical ultrasound transducer is employed for breast hyperthermia treatments. This work employs a computer simulation program based on an ideal ultrasound power deposition from a cylindrical transducer. The ultrasound power within the breast is assumed to be exponentially attenuated according to the penetration depth of the ultrasound beam and a uniform absorption for the entire breast is also assumed. The distribution of the specific absorption rate (SAR) ratio is employed to determine the heating pattern of a set of given parameters. The control parameters considered are the ultrasound frequency in the breast tissue, the active portion of cylindrical transducer, and the shifting distance between the central axes of the breast and the transducer. The effect of the breast size on the SAR ratio is also considered. Simulation results demonstrate that the breast size, the ultrasound frequency in breast tissue, the shifting distance, and the active portion of the cylindrical transducer are the potential parameters for influencing the distribution of the SAR ratio. High frequencies should be used for the superficial heating treatments and the active portion of the transducer can be changed to obtain a region with an appropriate SAR ratio to cover the treatment region. Low frequencies are used for deep heating treatments and the region of the high SAR ratio can be moved by shifting the transducer and its pattern is varied with the transducer's active portion. The distribution of the SAR ratio indicates the domain of treatable tumor size and tumor depth for a given set of parameters (driving frequency, shifting distance and active portion of the transducer, as well as breast diameter). Findings of this study can be used to know whether or not the tumor is treatable as well as to select the optimal driving frequency and the appropriate active portion of the cylindrical transducer for a treatment, and hopefully to design an appropriate cylindrical ultrasound heating system for breast tumors.

The application of competitive Hopfield neural network to medical image segmentation.

In this paper, a parallel and unsupervised approach using the competitive Hopfield neural network (CHNN) is proposed for medical image segmentation. It is a kind of Hopfield network which incorporates the winner-takes-all (WTA) learning mechanism. The image segmentation is conceptually formulated as a problem of pixel clustering based upon the global information of the gray level distribution. Thus, the energy function for minimization is defined as the mean of the squared distance measures of the gray levels within each class. The proposed network avoids the onerous procedure of determining values for the weighting factors in the energy function. In addition, its training scheme enables the network to learn rapidly and effectively. For an image of n gray levels and c interesting objects, the proposed CHNN would consist of n by c neurons and be independent of the image size. In both simulation studies and practical medical image segmentation, the CHNN method shows promising results in comparison with two well-known methods: the hard and the fuzzy c-means (FCM) methods.

Factors affecting the recovery of Legionella pneumophila serogroup 1 from cooling tower water systems.

A total of 20 water samples collected from the cooling towers at 20 different sites were analyzed under various conditions for the presence of Legionella pneumophila serogroup 1. A comparative assessment was performed to evaluate methods of sample collection (spray drops, beneath water at 20- to 40-cm depth, and water outlet), concentration (filtration and centrifugation), acid buffer treatment (no treatment, treatment for 3, 5, and 15 min), and CO2 incubation or candle jar incubation. The reduction in viable colonies and false negative rate were compared for the different factors. No quantitative differences in isolation of L. pneumophila serogroup 1 was found among samples collected from water at a depth of 20 to 40 cm, from water outlet, and from spray drops. Treatment in an acid buffer for 15 min significantly reduced the recovery rate, with a reduction in bacterial counts of about 40%, compared with a 3-min (12%) or a 5-min (25%) treatment. Acid buffer treatment for 3 or 5 min reduced the overgrowth of commensal flora. This treatment improved the selectivity but not the sensitivity for L. pneumophila serogroup 1. Colonies on plates incubated at 37 degrees C in a candle jar with a humidified atmosphere grew better than those incubated at 35 degrees C with 5% CO2. These results demonstrate that methods of sample collection, concentration, and incubation, but not collection site, can affect the isolation rate for L. pneumophila serogroup 1.

Emphysema surgery--loop ligation approach.

OBJECTIVES: To demonstrate the efficacy of using thoracoscopic endoloop ligation of bullae in patients with bullous emphysema. METHODS: From 1992 to 1997, 93 advanced age (mean age, 66 years) and oxygen dependency patients underwent thoracoscopic procedure using endoloop ligation for treatment of bullous emphysema. Clinical data were collected from chart review. Thoracoscopic loop ligation of bulla was carried out under general anesthesia with double lumen endotracheal tube and single lung ventilation. RESULTS: Eighty-two patients (88%) exhibited subjective improvement in their symptom status at 3-month follow-up (from grade 2 or 3 to grade 1 or 2) according to the modified Medical Research Council dyspnea scale. The mean duration of chest drainage was 7.5 days (range, 4-19 days). Average hospital stay was 9.5 (range, 5-26) days. There was no post-operative death. A comparison of pre-operative and post-operative functional evaluation was available in 27 patients who showed an average increase in FEV1 (from 0.89 to 1.12 l) and declined in residual volume after operation. Complications include persistent airleak over 10 days in nine patients (9.7%), wound infection in three patients and localized empyema in five patients. There was no recurrent after a mean follow-up of 37 months. CONCLUSION: Thoracoscopic loop ligation of bulla has proven to be a safe, reliable and cost effective means of technique for bullous emphysema.

Electrode models for electric current computed tomography.

This paper develops a mathematical model for the physical properties of electrodes suitable for use in electric current computed tomography (ECCT). The model includes the effects of discretization, shunt, and contact impedance. The complete model was validated by experiment. Bath resistivities of 284.0, 139.7, 62.3, 29.5 omega.cm were studied. Values of "effective" contact impedance zeta used in the numerical approximations were 58.0, 35.0, 15.0, and 7.5 omega.cm2, respectively. Agreement between the calculated and experimentally measured values was excellent throughout the range of bath conductivities studied. It is desirable in electrical impedance imaging systems to model the observed voltages to the same precision as they are measured in order to be able to make the highest resolution reconstructions of the internal conductivity that the measurement precision allows. The complete electrode model, which includes the effects of discretization of the current pattern, the shunt effect due to the highly conductive electrode material, and the effect of an "effective" contact impedance, allows calculation of the voltages due to any current pattern applied to a homogeneous resistivity field.