Quantitative and large-format histochemistry to characterize peripheral artery compositional gradients

The femoropopliteal artery (FPA) is a long, flexible vessel that travels down the anteromedial compartment of the thigh as the femoral artery and then behind the kneecap as the popliteal artery. This artery undergoes various degrees of flexion, extension, and torsion during normal walking movements. The FPA is also the most susceptible peripheral artery to atherosclerosis and is where peripheral artery disease manifests in 80% of cases. The connection between peripheral artery location, its mechanical flexion, and its physiological or pathological biochemistry has been investigated for decades; however, histochemical methods remain poorly leveraged in their ability to spatially correlate normal or abnormal extracellular matrix and cells with regions of mechanical flexion. This study generates new histological image processing pipelines to quantitate tissue composition across high-resolution FPA regions-of-interest or low-resolution whole-section cross-sections in relation to their anatomical locations and flexions during normal movement. Comparing healthy ovine femoral, popliteal, and cranial-tibial artery sections as a pilot, substantial arterial contortion was observed in the distal popliteal and cranial tibial regions of the FPA which correlated with increased vascular smooth muscle cells and decreased elastin content. These methods aim to aid in the quantitative characterization of the spatial distribution of extracellular matrix and cells in large heterogeneous tissue sections such as the FPA. RESEARCH HIGHLIGHTS: Large-format histology preserves artery architecture. Elastin and smooth muscle content is correlated with distance from heart and contortion during flexion. Cell and protein analyses are sensitive to sectioning plane and image magnification.

An effective and comprehensible method to detect and evaluate retinal damage due to diabetes complications

The leading cause of vision loss globally is diabetic retinopathy. Researchers are making great efforts to automatically detect and diagnose correctly diabetic retinopathy. Diabetic retinopathy includes five stages: no diabetic retinopathy, mild diabetic retinopathy, moderate diabetic retinopathy, severe diabetic retinopathy and proliferative diabetic retinopathy. Recent studies have offered several multi-tasking deep learning models to detect and assess the level of diabetic retinopathy. However, the explanation for the assessment of disease severity of these models is limited, and only stops at showing lesions through images. These studies have not explained on what basis the appraisal of disease severity is based. In this article, we present a system for assessing and interpreting the five stages of diabetic retinopathy. The proposed system is built from internal models including a deep learning model that detects lesions and an explanatory model that assesses disease stage. The deep learning model that detects lesions uses the Mask R-CNN deep learning network to specify the location and shape of the lesion and classify the lesion types. This model is a combination of two networks: one used to detect hemorrhagic and exudative lesions, and one used to detect vascular lesions like aneurysm and proliferation. The explanatory model appraises disease severity based on the severity of each type of lesion and the association between types. The severity of the disease will be decided by the model based on the number of lesions, the density and the area of the lesions. The experimental results on real-world datasets show that our proposed method achieves high accuracy of assessing five stages of diabetic retinopathy comparable to existing state-of-the-art methods and is capable of explaining the causes of disease severity.

Nivolumab for locally advanced and metastatic cutaneous squamous cell carcinoma (NIVOSQUACS study)-Phase II data covering impact of concomitant haematological malignancies

BACKGROUND

Monoclonal antibodies, such as cemiplimab and pembrolizumab, against the programmed death receptor (PD)-1 have become the current standard of care and first-line treatment of advanced cutaneous squamous cell carcinoma (cSCC), proving remarkable clinical benefit and acceptable safety.

OBJECTIVES

To assess efficacy and safety of the anti-PD-1 antibody nivolumab in patients with locally advanced and metastatic cSCC.

METHODS

Patients received open-label nivolumab 240 mg intravenously every 2 weeks for up to 24 months. Patients with concomitant haematological malignancies (CHMs), either non-progressing or stable under active therapy, were eligible for inclusion.

RESULTS

Of 31 patients with a median age of 80 years, 22.6% of patients achieved an investigator assessed complete response, resulting in an objective response rate (ORR) of 61.3% and a disease control rate (DCR) of 64.5%. Progression-free survival (PFS) was 11.1 months, and the median overall survival (OS) was not reached after 24 weeks of therapy. Median follow-up was 23.82 months. Subgroup analysis of the CHM cohort (n = 11; 35%) revealed an ORR of 45.5%, a DCR of 54.5%, a median PFS of 10.9 months, and median OS of 20.7 months. Treatment related adverse events were reported in 58.1% of all patients (19.4% grade 3, the remaining grade 1 or 2). PD-L1 expression and CD-8+ T-cell infiltration did not significantly correlate with clinical response, although a trend towards a shorter PFS of 5.6 months was observed with PD-L1 negativity and low CD8+ intratumoral infiltration.

CONCLUSION

This study demonstrated robust clinical efficacy of nivolumab in patients with locally advanced and metastatic cSCCs and a tolerability comparable to data of other anti-PD-1 antibodies. Favourable outcomes were obtained despite involving the oldest hitherto reported study cohort for anti-PD-1 antibodies and a significant proportion of CHM patients prone to high risk tumours and an aggressive course otherwise typically excluded from clinical trials.

Perspectives on COVID-19 prevention and treatment using herbal medicine in Vietnam: A cross-sectional study

INTRODUCTION

The significance of herbal medicine (HM) during the COVID-19 pandemic has been confirmed. Nevertheless, limited studies have included the people perspectives on COVID-19 prevention/treatment using herbal medicine in Vietnam. Thus, this study tackled the aforementioned issue.

METHODS

Online-based cross-sectional study was conducted in Vietnamese adults between February-April 2021. Descriptive analysis, regression and Chi-squared tests were implemented for the statistical purposes.

RESULTS

total of 787 respondents attended the study, 368 (46.8%) confirmed that they use herbal medicine/nutritional supplements for COVID-19 prevention/treatment. Over 50% of the respondents possessed positive perspective on vitamin C ingestion. Using herbal medicine for external use as a disinfectant was mostly preferred. Respondents who had a 'very good' health self-perception or who lived in rural areas, were more likely to have a positive opinion in the COVID-19 prevention/treatment using herbal medicine. The main barrier for herbal medicine utilization was the deficiency of personal experience or expert advice.

CONCLUSION

The Vietnamese people commonly utilize herbal medicine for the COVID-19 prevention/treatment. These data might help policy-makers in managing the public knowledge and practice on herbal medicine use in Vietnam.

Preclinical Immune Response and Safety Evaluation of the Protein Subunit Vaccine Nanocovax for COVID-19

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global health concern. The development of vaccines with high immunogenicity and safety is crucial for controlling the global COVID-19 pandemic and preventing further illness and fatalities. Here, we report the development of a SARS-CoV-2 vaccine candidate, Nanocovax, based on recombinant protein production of the extracellular (soluble) portion of the spike (S) protein of SARS-CoV-2. The results showed that Nanocovax induced high levels of S protein-specific IgG and neutralizing antibodies in three animal models: BALB/c mouse, Syrian hamster, and a non-human primate (Macaca leonina). In addition, a viral challenge study using the hamster model showed that Nanocovax protected the upper respiratory tract from SARS-CoV-2 infection. Nanocovax did not induce any adverse effects in mice (Mus musculus var. albino) and rats (Rattus norvegicus). These preclinical results indicate that Nanocovax is safe and effective.

Structural basis for loading and inhibition of a bacterial T6SS phospholipase effector by the VgrG spike

The bacterial type VI secretion system (T6SS) is a macromolecular machine that injects effectors into prokaryotic and eukaryotic cells. The mode of action of the T6SS is similar to contractile phages: the contraction of a sheath structure pushes a tube topped by a spike into target cells. Effectors are loaded onto the spike or confined into the tube. In enteroaggregative Escherichia coli, the Tle1 phospholipase binds the C-terminal extension of the VgrG trimeric spike. Here, we purify the VgrG-Tle1 complex and show that a VgrG trimer binds three Tle1 monomers and inhibits their activity. Using covalent cross-linking coupled to high-resolution mass spectrometry, we provide information on the sites of contact and further identify the requirement for a Tle1 N-terminal secretion sequence in complex formation. Finally, we report the 2.6-Å-resolution cryo-electron microscopy tri-dimensional structure of the (VgrG)₃ -(Tle1)₃ complex revealing how the effector binds its cargo, and how VgrG inhibits Tle1 phospholipase activity. The inhibition of Tle1 phospholipase activity once bound to VgrG suggests that Tle1 dissociation from VgrG is required upon delivery.

Clinical diversity and treatment approaches to blastic plasmacytoid dendritic cell neoplasm: a retrospective multicentre study

BACKGROUND

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, aggressive type of haematologic precursor malignancy primarily often manifesting in the skin. We sought to provide a thorough clinical characterization and report our experience on therapeutic approaches to BPDCN.

METHODS

In the present multicentric retrospective study, we collected all BPDCN cases occurring between 05/1999 and 03/2018 in 10 secondary care centres of the German-Swiss-Austrian cutaneous lymphoma working group.

RESULTS

A total of 37 BPDCN cases were identified and included. Almost 90% of the patients had systemic manifestations (bone marrow, lymph nodes, peripheral blood) in addition to skin involvement. The latter presented with various types of cutaneous lesions: nodular (in more than 2/3) and bruise-like (in 1/3) skin lesions, but also maculopapular exanthema (in circa 1/6). Therapeutically, 22 patients received diverse combinations of chemotherapeutic regimens and/or radiotherapy. Despite initial responses, all of them ultimately relapsed and died from progressive disease. Eleven patients underwent haematopoietic stem cell transplantation (HSCT; autologous HSCT n = 3, allo-HSCT n = 8). The mortality rate among HSCT patients was only 33.33% with a median survival time of 60.5 months.

CONCLUSION

Our study demonstrates the clinical diversity of cutaneous BPDCN manifestations and the positive development observed after the introduction of HSCT.

Correction of Upper Incisor Proclination by Applying Lingual Crown Torque with Pre adjusted Lingual Brackets in a Skeletal-Class III Patient - Case Report

BACKGROUND:

After levelling and alignment in skeletal Class III patients with upper anterior crowding, the upper incisors usually have excessive proclination. In these cases, the upper incisors’ axial proclination need to be reduced to improve esthetics.

CASE REPORT:

This case report presents an invisible orthodontic treatment of a 24-year-old adult female patient with skeletal Class III relationship, anterior crossbite, proclined upper incisors, and reduced incisor showing. Patients denied extraction and interproximal reduction. With multi-slotted lingual brackets and straight archwires, we applied lingual crown torque to upper anterior teeth to reduce axial proclination. The resulting uprighted position of upper incisors led to increased incisor showing. A good smile and stable occlusion were obtained after 15 months of active treatment.

CONCLUSION:

The use of lingual brackets to apply lingual crown torque helps to reduce axial proclination and increasing upper incisor showing without interproximal reduction nor extraction in skeletal Class III patients with upper anterior crowding.

Meso/micropore-controlled hierarchical porous carbon derived from activated biochar as a high-performance adsorbent for copper removal

High-quality meso/micropore-controlled hierarchical porous carbon (HPC) was synthesized by a hard template method utilizing rice husk biochar and then used to adsorb copper ions from an aqueous solution. The preparation procedure included two main steps: base leaching and physicochemical activation. During the activation process, the porosity characteristics (i.e., specific surface area and meso/micropore ratio) were controlled by altering the KOH impregnation ratio, activation time, and temperature under the CO₂ atmosphere. In addition, a copper adsorption study was performed using three HPC samples with different pore structures and characteristics. The results of this study indicate that the adsorption capacity of HPC material derived from rice husk biochar is strongly influenced by its meso/micropore ratio. As evidenced, HPC 3-0.5-800, which was impregnated by a KOH:biochar ratio of 3 and activated at 800°C for 0.5h under a CO₂ atmosphere, has a very high specific surface area of 2330 m²g^-1 with an 81% mesopore to total specific surface area. Importantly, it exhibited a superior adsorption capacity of 265mgg^-1 and rapid adsorption kinetics for copper ions. The improvement is ascribed to the high specific surface area and favorable hierarchical structure. The findings demonstrate the feasibility of controlling the hierarchical pore structure of rice husk biochar-derived carbons as high-performance adsorbents for copper ion removal from water.

Design and performance of a coarse media, high hydraulic load polishing wetland for steel industry wastewater

This paper presents the design of a constructed wetland (CW) system in an area with limited land availability, resulting in high hydraulic loads. The CW was constructed to act as a buffering/ polishing step after stabilization ponds for steel industry wastewater post-treatment. A pilot test with two different filter media (50-100mm vs 40-60mm diameter) indicated that a flow rate increase from 49.5 m³/h to 122.4 m³/h would lead to a head loss increase from 2.9cm to 8.7cm, and more than double that for the finer gravel. This was substantially higher than the calculated theoretical values, though the relation with flow rate was similar. Four full scale wetland cells (CW1, CW2, CW3 and CW4) were constructed using the coarser gravel. A design value of total head loss of 1.01m over the total system length, with a design flow of 36,000 m³/day, was expected based on pilot test results. During the first operation year (September 2017 to July 2018), the pond-CW system has received wastewater already meeting required discharge standards. The effluent from the CWs had consistently lower concentrations of all measured variables, and met the predicted values for biochemical oxygen demand (BOD₅), total nitrogen (TN) and NH₄ ⁺-N. Highest removal efficiencies were achieved for NH₄ ⁺-N (>90%), Mn (>60%) and Fe (45%) with removal efficiencies for TN (14%), BOD₅ and chemical oxygen demand (COD) (around 30%). Concentrations of phenol, CN^- and Cr⁶⁺ were below 10, 4 and 3μg/l, respectively, in in- and outflows. An appreciated benefit of the wetland was the 'green element' in the industrial landscape.

[Adverse effects of immunotherapy : Clinical aspects, radiological and nuclear medicine results]

BACKGROUND

The increasing use of immunotherapy in oncology increases the need for radiologic evaluation of frequent and severe immune-related adverse events.

OBJECTIVE

Determination of the incidence and manifestation of radiologic and nuclear medicine findings of immune-related adverse events.

MATERIAL AND METHODS

Literature review of clinical and imaging findings of immune-related adverse events induced by the immune checkpoint inhibitors ipilimumab, nivolumab and pembrolizumab. Findings are illustrated with pictorial examples and contrasted to other relevant differential diagnoses.

RESULTS

The most frequent imaging manifestations are colitis, hepatitis, pancreatitis, hypophysitis, pneumonitis, arthritis and sarcoid-like lymphadenopathy. Severe to life-threatening complications may result from colitis, pneumonitis and hypophysitis. A clear differentiation from other autoimmune diseases and discrimination of immune-related and infectious pulmonary findings can be very difficult and need close multidisciplinary collaboration.

CONCLUSION

Knowledge of clinical and imaging findings of adverse events induced by immunotherapy is essential for timely and adequate therapeutic decisions. In addition to staging and follow-up imaging, identification and monitoring of immune-related adverse events adds to the radiologic responsibility in oncologic care.

Primary education in Vietnam and pupil online engagement

Purpose

The purpose of this paper is to explore the disparities in social awareness and use of the internet between urban and rural school children in the North of Vietnam.

Design/methodology/approach

A total of 525 pupils, aged 9-11 years old, randomly selected from seven urban and rural schools, who are internet users, participated in the study and consented to responding to a questionnaire adapted from an equivalent European Union study. A comparative statistical analysis of the responses was then carried out, using IBM SPSS v21, which consisted of a descriptive analysis, an identification of personal self-development opportunities, as well as issues related to pupils’ digital prowess and knowledge of internet use and internet safety, including parental engagement in their offspring’s online activities.

Findings

The study highlights the fact that children from both the urban and rural regions of the North of Vietnam mostly access the internet from home, but with more children in the urbanized areas accessing it at school than their rural counterparts. Although children from the rural areas scored lower on all the internet indicators, such as digital access and online personal experience and awareness, there was no disparity in awareness of internet risks between the two sub-samples. It is noteworthy that there was no statistically significant gender difference towards online activities that support self-development. In relation to safe internet usage, children are likely to seek advice from their parents, rather than through teachers or friends. However, they are not yet provided with an effective safety net while exposing themselves to the digital world.

Originality/value

Although the Vietnamese national curriculum on the computer science subject does not explicitly cover the use of the internet and its related aspects, the majority of children who took part in this study claimed to have used the internet in their learning activities. This emphasises the urgent need for the Ministry of Education and educators in the country to not only improve information and communication technology facilities in schools, but also to revise the computer science curriculum in order to provide a supportive environment for learning development and collectively advocate the dynamics of internet use in order to ensure safe access and use by the children.

The Impact of Online Learning Activities on Student Learning Outcome in Blended Learning Course

The aim of the study is to determine the impact of online learning activities on learning outcomes of students who participated in the blended learning course, focusing specifically on skill-based courses. The learning outcomes or results of a learner are usually measured by scores, knowledge or skills gained in the course. In blended learning courses, the learning outcomes can be assessed according to many criteria. In this study, interactive activities such as teacher–student interaction, student–student interaction, student–content interaction and student–technology interaction are considered. Undergraduate students participated in the blended learning course in which formative assessment was used to evaluate student learning outcomes by the combination of different learning activities through a learning management system. The quantitative results obtained by using regression analysis of data from the system showed that the students who effectively interacted with learning activities in the course have better results. Quantitative analytical results indicated that student–student interaction has a greater impact on student learning outcomes. These learning activities are used for interactive activities as suggestions for teachers to design and implement learning activities for blended learning courses.

Towards the implementation of an assessment-centred blended learning framework at the course level

Purpose

The purpose of this paper is to build an assessment-centred blended learning (BL) framework to assess learners, to analyse and to evaluate the impact of the technology support in the form of formative assessment in students’ positive learning.

Design/methodology/approach

This research proposed an assessment-centred BL framework at the course level to support formative assessment in students by designing a variety of online learning activities combined with e-assessment tools of learning management system (LMS) to analyse and evaluate the impact of the technology application in the form of formative assessment student learning initiative. The author has tested this model in five years with more than 200 courses.

Findings

Experimental results have shown that formative assessment evaluation form is more efficient when supported by technology such as LMS.

Originality/value

This research proposed an assessment-centred BL framework at the course level by using LMS tools combined with traditional teaching.

Transmission of helminth eggs through hands in a high-risk community

BACKGROUND

The role that hands play in the transmission of Ascaris is not well understood.

METHODS

A newly developed method to quantify the presence helminth eggs on hands was tested among a group of farmers in Vietnam. High turbidity in hand rinse samples meant that the adopted sugar solution had to be replaced by zinc sulphate as a flotation solution.

RESULTS

The survey found 34% (31/90) of study participant hands' were positive for helminth eggs, though concentrations were low and ranged from 0-10 eggs/2 hands. The use of fresh excreta in agriculture was the only variable that showed an association with the concentrations of eggs found on hands.

CONCLUSIONS

The results highlight the need to promote handwashing with soap to prevent the transmission of soil-transmitted helminth infections.

The onset of type 2 diabetes: proposal for a multi-scale model

Background

Type 2 diabetes mellitus (T2D) is a common age-related disease, and is a major health concern, particularly in developed countries where the population is aging, including Europe. The multi-scale immune system simulator for the onset of type 2 diabetes (MISSION-T2D) is a European Union-funded project that aims to develop and validate an integrated, multilevel, and patient-specific model, incorporating genetic, metabolic, and nutritional data for the simulation and prediction of metabolic and inflammatory processes in the onset and progression of T2D. The project will ultimately provide a tool for diagnosis and clinical decision making that can estimate the risk of developing T2D and predict its progression in response to possible therapies. Recent data showed that T2D and its complications, specifically in the heart, kidney, retina, and feet, should be considered a systemic disease that is sustained by a pervasive, metabolically-driven state of inflammation. Accordingly, there is an urgent need (1) to understand the complex mechanisms underpinning the onset of this disease, and (2) to identify early patient-specific diagnostic parameters and related inflammatory indicators.

Objective

We aim to accomplish this mission by setting up a multi-scale model to study the systemic interactions of the biological mechanisms involved in response to a variety of nutritional and metabolic stimuli and stressors.

Methods

Specifically, we will be studying the biological mechanisms of immunological/inflammatory processes, energy intake/expenditure ratio, and cell cycle rate. The overall architecture of the model will exploit an already established immune system simulator as well as several discrete and continuous mathematical methods for modeling of the processes critically involved in the onset and progression of T2D. We aim to validate the predictions of our models using actual biological and clinical data.

Results

This study was initiated in March 2013 and is expected to be completed by February 2016.

Conclusions

MISSION-T2D aims to pave the way for translating validated multilevel immune-metabolic models into the clinical setting of T2D. This approach will eventually generate predictive biomarkers for this disease from the integration of clinical data with metabolic, nutritional, immune/inflammatory, genetic, and gut microbiota profiles. Eventually, it should prove possible to translate these into cost-effective and mobile-based diagnostic tools.

Optimising water and phosphorus management in the urban environmental sanitation system of Hanoi, Vietnam

Many areas in the world face clean water scarcity problems and phosphorus reserves are likely to be depleted in the near future. Still, a large amount of clean water is used to transport excreta through sewer systems. Most of the wastewater generated worldwide is discharged untreated into aquatic systems and leads to water pollution and loss of valuable nutrients. In Hanoi, Vietnam's capital city, high population and economic growth as well as industrialisation have led to a decrease in groundwater level and to serious river and lake pollution. A probabilistic model, simulating the impact of measures on groundwater abstraction and nutrient recovery, was used to determine the impact of policy changes in Hanoi. The results obtained reveal that harmonising environmental sanitation and agricultural systems with one another will considerably increase nutrient recovery for food production, lower expenditure for artificial fertilisers and reduce the nutrient load into the environment. The model can be applied in urban areas of developing countries to assist in the design of environmental sanitation concepts.

Acute pulmonary edema, capillaritis and alveolar hemorrhage: pulmonary manifestations coexistent in antiphospholipid syndrome and systemic lupus erythematosus?

Pulmonary capillaritis and alveolar hemorrhage are rare yet serious and life threatening complications of systemic lupus erythematosus (SLE). Pulmonary manifestations of antiphospholipid syndrome (APS) are similar and include, apart from pulmonary embolism and pulmonary hypertension, pulmonary capillaritis, diffuse alveolar hemorrhage and respiratory insufficiency in patients with catastrophic APS. Herein, we described the radiological features of three patients with pulmonary and SLE-associated APS, manifested with pulmonary edema, capillaritis and alveolar hemorrhage. We observed that the radiological features of pulmonary APS shared close resemblance to those of pulmonary SLE. Based on these findings, we conclude that both entities are not only histologically, but also radiologically indistinguishable from each other, suggesting a mutual pathogenetic mechanism. This raises the question of whether some of the reported lupus pneumonitis cases in the past might be manifestations of APS rather than of SLE.

Multiple tolerance of Rhodotorula glutinis R-1 to acid, aluminum ion and manganese ion, and its unusual ability of neutralizing acidic medium

A red yeast isolated from the acidic water of Kusatsu hot spring could grow in an acidic medium of pH 1.5 and was identified as Rhodotorula glutinis. Electron microscope observations (scanning electron microscopy [SEM] and transmission electron microscopy [TEM]) showed that cell envelope became wrinkled and thick as the pH values of media became lower. The cell membrane grown at pH 1.5 was about four times as thick as that grown at pH 6.0. It was suggested that the change of cell envelope plays an important role in the acid tolerance. Cellular proteins at pH 1.5 appeared to be different from those at pH 6.0 and the amounts of phospholipids and non-phospholipids increased and decreased under low pH conditions, respectively. The acid-tolerant yeast also showed strong resistance to both aluminum and manganese ions. An acidic medium (pH 3.0) containing these ions (100 mM) was shifted to neutral pH by long-term cultivation of the red yeast, suggesting the potential of using this yeast in the bioremediation of acidic soil containing these ions at a high level.

Human herpesvirus-8 infection of umbilical cord-blood-derived CD34+ stem cells enhances the immunostimulatory function of their dendritic cell progeny

CD34(+) progenitor cells carrying human herpesvirus-8, Kaposi's sarcoma-associated herpesvirus (HHV-8/KSHV), have been described in the peripheral blood of AIDS patients suffering from Kaposi's sarcoma (KS). In this study, we investigated the influence of HHV-8 on the differentiation of CD34(+) progenitor cells. Native CD34(+) cells derived from cord blood could be infected by a laboratory strain of HHV-8, as shown by immunofluorescence staining and polymerase chain reaction, but no significant initial maturation/differentiation effects were observed. In addition, these infected cells were differentiated into immature and mature dendritic cells (DCs) using cytokine induction with recombinant human granulocyte-macrophage colony-stimulating factor (rhGm-CSF), recombinant human tumor necrosis factor (rhTNF-alpha) and recombinant human stem cell factor (rhSCF). Double immunofluorescence and flow cytometry studies demonstrated that virus infection did not impair the development of immature and mature DC populations. Subsequently, the immunostimulating capacity of DC populations was tested in a mixed lymphocyte reaction using allogeneic T-cells. The HHV-8-infected CD34(+) progenitor cell-derived mature DC population showed a significantly enhanced antigen-presenting capacity, compared to non-infected DCs, which was not observed with the immature DCs. This suggests stimulation of DC function by HHV-8 infection. Because there are only a small percentage of HHV-8-positive DCs in the preparations and because it is not clear whether infection is abortive or productive to some extent, this seems to be most likely due to an indirect viral effect.

Tolerability and efficacy of N-chlorotaurine in comparison with chloramine T for the treatment of chronic leg ulcers with a purulent coating: a randomized phase II study

BACKGROUND

The well-known active chlorine compound chloramine T (CAT) with broad-spectrum antimicrobial activity is in common therapeutic use for leg ulcers with purulent coatings; however, this treatment is painful. The tolerability of the less aggressive N-chlorotaurine (NCT), an endogenous compound also produced in vivo by stimulated human granulocytes, could be superior.

OBJECTIVES

To assess the tolerability and efficacy of NCT in the cleaning of purulent coatings in chronic leg ulcers in comparison with CAT.

METHODS

In a double-blind, randomized phase IIb clinical study 40 patients were treated for a median of 7 days (range 3-14) with a 1% aqueous solution of either NCT (20 subjects) or CAT (20 subjects) by twice-daily application of dressings soaked in the test solutions. Criteria for evaluation of tolerability were intensity and duration of pain caused by the ulcer therapy and scores of tissue toxicity (necrosis, granulation tissue and re-epithelialization). Therapeutic efficacy was graded as scores of intensity of purulent coating of the ulcers.

RESULTS

The concentration tolerated in vitro by human epidermoid carcinoma cells was at least 10-fold higher for NCT (0.01%) compared with CAT (0.0001-0.001%). There was significantly less pain caused by NCT compared with CAT (P < 0.05) on days 1 and 4 and a trend for a shorter duration of pain (P = 0.093). The scores of intensity of coating improved without difference in both treatment groups, whereas granulation and re-epithelialization appeared earlier in the NCT group (P < 0.05). Non-quantitative microbiological cultures from ulcer smears revealed persistence of colonization by bacterial species in approximately half of both treatment groups.

CONCLUSIONS

Both active chlorine compounds were helpful in reducing purulent coatings. Because of its lower toxicity and better tolerability, NCT is of advantage in the treatment of leg ulcers.

Synthesis of the marine natural product barbamide

The first total synthesis of the trichlorinated natural product barbamide is described. The convergent approach involves coupling (S)-3-trichloromethylbutanoyl chloride with Meldrum's acid (2,2-dimethyl-1,3-dioxane-4,6-dione) to give 15 followed by addition of the novel secondary amine N-methyl-(S)-dolaphenine 2 (prepared in 6 steps and 24% overall yield from N-Cbz-L-phenylalanine) to give the beta-keto amide 16 which was converted directly to the required (E)-enol ether.

Controlling binocular rivalry

Binocular rivalry is the alternating perception that occurs when the two eyes are presented with incompatible stimuli. We have developed a new method for controlling binocular rivalry and measuring its progress. One eye views a static grating while the fellow eye views a grating that smoothly and cyclically varies between two orientations, one the same as the static grating and the other orthogonal. Contrast sensitivity was tested monocularly a number of times during the stimulus cycle. When the eye viewing the static grating was tested, sensitivity varied between maximum and minimum values as the conditioning stimulus varied from binocularly compatible to incompatible. The interocular suppression thus demonstrated was limited to the eye viewing the static grating; variations in the fellow eye's sensitivity were due to interocular masking alone.

The depth and selectivity of suppression in binocular rivalry

Binocular rivalry occurs when the two eyes are presented with incompatible stimuli and the perceived image alternates between the two stimuli. The aim of this study was to find out whether the periodic perceptual loss of a monocular stimulus during binocular rivalry is mirrored by a comparable loss of contrast sensitivity. We presented brief test stimuli to one eye while its conditioning stimulus was dominant or suppressed. The test stimuli were varied widely across four stimulus domains--namely, the relative stimulation of medium- and long-wavelength-sensitive cones, duration, spatial frequency, and grating orientation. The result in each case was the same. Suppression depended slightly or not at all on the type of test stimulus, and contrast sensitivity during suppression was around 64% of that during dominance. The effect of suppression on sensitivity is therefore very weak, relative to its effect on the perceived image. Furthermore, suppression was largely independent of the similarity between the conditioning and the test stimuli, indicating that our results are better explained by eye suppression than by stimulus suppression. A model is presented to account for the small, monocular sensitivity loss during suppression: It assumes that test detection precedes conditioning stimulus perception in the visual pathway.

Rapid activation of protein kinase B/Akt has a key role in antiapoptotic signaling during liver regeneration

Liver regeneration is controlled by multiple signaling pathways induced by a variety of growth factors, hormones, and cytokines. Here we report that protein kinase B (PKB)/Akt, part of a key cell survival signaling pathway, is markedly activated after partial hepatectomy (PHX). The antiapoptotic protein Bad, a downstream target of PKB/Akt, is also phosphorylated. This cascade can be activated by various factors in primary hepatocytes, with the strongest activation by insulin and the alpha1-adrenergic agonist phenylephrine (PE), followed by IL-6, epidermal growth factor (EGF), and hepatocyte growth factor (HGF). Pretreatment of cells with the specific PI3 kinase inhibitor LY294002 abolished insulin- or PE-activation of PKB/Akt, suggesting that activation of PKB/Akt is mediated by a PI3 kinase-dependent mechanism. In vivo administration of PE, insulin, IL-6, HGF, or EGF to mice markedly stimulated PKB/Akt in the liver, with the strongest stimulation induced by insulin and PE. Moreover, HGF and insulin were able to attenuate transforming growth factor beta-induced apoptosis in hepatic cells, and these effects were antagonized by LY294002. Taken together, these findings suggest that rapid activation of PKB/Akt is a key antiapoptotic signaling pathway involved in liver regeneration.

IL-10 attenuates IFN-alpha-activated STAT1 in the liver: involvement of SOCS2 and SOCS3

Interleukin-10 (IL-10) has been used in the treatment of viral hepatitis in interferon-alpha (IFN-alpha) non-responders while patients who have high levels of IL-10 are poorly responsive to IFN-alpha. The mechanism underlying such controversial functions of IL-10 remains unknown. Here we demonstrated that injection of IL-10 into mice attenuated IFN-alpha-induced signal transducer and activator transcription factor (STAT)1 tyrosine phosphorylation in the liver. Reverse transcriptase-polymerase chain reaction assay demonstrated that mouse liver expressed high levels of IL-10 receptor 2 (IL-10R2) but low levels of IL-10R1. Injection of IL-10 into mice activated STAT3 but not STAT1 tyrosine phosphorylation and induced suppressor of cytokine signal 2 (SOCS2), SOCS3, and cytokine-inducible SH2 protein (CIS) mRNA expression in the liver. Furthermore, overexpression of SOCS2 or SOCS3 inhibited IFN-alpha-induced reporter activity in hepatic cells. These findings suggest that IL-10 inhibits IFN-alpha-activated STAT1 in the liver, at least in part, by inducing SOCS2, SOCS3, and CIS expression, which may be responsible for the resistance of IFN-alpha therapy in patients who have high levels of IL-10 and recommends that IL-10 treatment for viral hepatitis should be cautious.

Interferons activate the p42/44 mitogen-activated protein kinase and JAK-STAT (Janus kinase-signal transducer and activator transcription factor) signalling pathways in hepatocytes: differential regulation by acute ethanol via a protein kinase C-dependent mechanism

Interferons (IFNs) have been used in the treatment of viral hepatitis. However, their effectiveness is much reduced (<10%) in alcoholics. The mechanism underlying this resistance remains unknown. Here, we report that IFN-alpha/beta and IFN-gamma rapidly activate the JAK-STAT1 (Janus kinase-signal transducer and activator transcription factor 1) and p42/44 mitogen-activated protein kinase (p42/44 MAPK) in freshly isolated rat hepatocytes. Treatment of hepatocytes with 25-100 mM ethanol for 30 min inhibited IFN-beta- or IFN-gamma-induced STAT1 activation and tyrosine phosphorylation. The inhibitory effect of ethanol was not reversed by pretreatment with either sodium vanadate, a non-selective tyrosine phosphatase inhibitor, or with MG132, a specific proteasome inhibitor. This suggests that protein tyrosine phosphatases or the ubiquitin-proteasome pathway are not involved in the inhibitory action of ethanol. In contrast with the JAK-STAT signalling pathway, acute ethanol exposure significantly potentiated IFN-beta or IFN-gamma-induced activation of p42/44 MAPK, and caused marked activation of protein kinase C (PKC). Inhibition of PKC partially antagonized ethanol attenuation of IFN-induced STAT1 activation, suggesting that PKC may be involved. Taken together, these findings suggest that the ability of biologically relevant concentrations of ethanol (less than 100 mM) to markedly inhibit IFN-activated STAT1 is one of the cellular mechanisms responsible for the observed resistance of IFN therapy in alcoholics.

Activation of mitogen-activated protein kinases is required for alpha1-adrenergic agonist-induced cell scattering in transfected HepG2 cells

Activation of alpha1B-adrenergic receptors ((alpha1B)AR) by phenylephrine (PE) induces scattering of HepG2 cells stably transfected with the (alpha1B)AR (TFG2 cells). Scattering was also observed after stimulation of TFG2 cells with phorbol myristate acetate (PMA) but not with hepatocyte growth factor/scatter factor, epidermal growth factor, or insulin. PMA but not phenylephrine rapidly activated PKCalpha in TFG2 cells, and the highly selective PKC inhibitor bisindolylmaleimide (GFX) completely abolished PMA-induced but not PE-induced scattering. PE rapidly activated p44/42 mitogen-activated protein kinase (MAPK), p38 MAPK, c-Jun N-terminal kinase (JNK), and AP1 (c-fos/c-jun). Selective blockade of p42/44 MAPK activity by PD98059 or by transfection of a MEK1 dominant negative adenovirus significantly inhibited the PE-induced scattering of TFG2 cells. Selective inhibition of p38 MAPK by SB203850 or SB202190 also blocked PE-induced scattering, whereas treatment of TFG2 cells with the PI3 kinase inhibitors LY294002 or wortmannin did not inhibit PE-induced scattering. Blocking JNK activation with a dominant negative mutant of JNK or blocking AP1 activation with a dominant negative mutant of c-jun (TAM67) significantly inhibited PE-induced cell scattering. These data indicate that PE-induced scattering of TFG2 cells is mediated by complex mechanisms, including activation of p42/44 MAPK, p38 MAPK, and JNK. Cell spreading has been reported to play important roles in wound repair, tumor invasion, and metastasis. Therefore, catecholamines acting via the (alpha1)AR may modulate these physiological and pathological processes.

Alpha(1) adrenergic agonist induction of p21(waf1/cip1) mRNA stability in transfected HepG2 cells correlates with the increased binding of an AU-rich element binding factor

Stimulation of transfected HepG2 cells (TFG2) with the alpha(1)-adrenergic agonist phenylephrine (PE) significantly activated p21(waf1/cip1) gene expression without affecting p53 gene expression. Northern blotting and reporter assay demonstrated that this induction was due to PE stimulation of p21(waf1/cip1) mRNA stability. To further define the underlying mechanism, we prepared a chloramphenicol acetyltransferase (CAT)-p21(waf1/cip1) 3'-untranslated region (3'-UTR) hybrid construct by inserting the 3'-UTR of p21(waf1/cip1) mRNA just downstream from the CAT coding sequence and transfected it into TFG2 cells. PE treatment enhanced the activity of this construct by 6-fold. Deletion analyses indicated that an AU-rich element (AURE) located between 553 to 625 within the p21(waf1/cip1) 3'-UTR was required for this induction. RNA gel shift assays demonstrated that this AURE bound an RNA-binding protein. This protein has been purified 5000-fold from PE-treated TFG2 cells by heparin-Sepharose and RNA affinity chromatography. SDS-polyacrylamide gel electrophoresis, UV cross-linking, and Northwestern analyses indicated the molecular mass of this protein as 24 and 52 kDa. Finally, PE treatment markedly enhanced this RNA-protein binding by a p42/44 mitogen-activated protein kinase-dependent mechanism. These data suggest that the AURE located between 553 and 625 within the p21(waf1/cip1) mRNA 3'-UTR, which binds an RNA-binding protein, is responsible for PE-induced p21(waf1/cip1) mRNA stability.

Endothelial injury in internal organs of University of California at Davis line 200 (UCD 200) chickens, an animal model for systemic sclerosis (Scleroderma)

Systemic sclerosis (SSc) is a multisystem disorder characterized by mononuclear cell infiltration and fibrosis. Using skin samples from human SSc and UCD 200 chickens, which spontaneously develop a hereditary disease closely resembling human SSc, we have shown previously that endothelial cell apoptosis is a primary event in the pathogenesis of SSc. The aim of the present study was to investigate the initial disease stage in visceral organs of UCD 200 chickens with special emphasis on endothelial apoptosis, mononuclear cell infiltration and collagen deposition using tissue samples from oesophagus, lung, heart, kidney and liver. Apoptotic endothelial cells were detected by terminal deoxynucleotidyl transferase-mediated FITC-dUTP nick end labeling (TUNEL), mononuclear cell infiltrates were stained with hematoxylin and eosin, and increased collagen deposition was demonstrated by Goldner staining. Apoptotic endothelial cells were detected in oesophagus, lung and kidney of UCD 200 chickens at the initial stage of the disease. No apoptotic endothelial cells were found in heart or liver of UCD 200 or in visceral organs of healthy normal UCD 058 control chickens. Oesophagus of UCD 200 chickens, which was the most affected internal organ, showed mononuclear cell infiltrations and increased deposition of collagen. Perivascular inflammatory infiltrates and collagen deposition appeared later than endothelial cell apoptosis. These data support the hypothesis that endothelial cell apoptosis initiates the disease process, followed by mononuclear cell infiltration and fibrosis.

Cross-talk between alpha(1B)-adrenergic receptor (alpha(1B)AR) and interleukin-6 (IL-6) signaling pathways. Activation of alpha(1b)AR inhibits il-6-activated STAT3 in hepatic cells by a p42/44 mitogen-activated protein kinase-dependent mechanism

Treatment of primary rat hepatocytes or tranfected HepG2 cells with the alpha(1B)-adrenergic receptor (alpha(1B)AR) agonist phenylephrine (PE) significantly inhibited interleukin 6 (IL-6)-induced STAT3 binding, tyrosine phosphorylation, and IL-6-induced serum amyloid A mRNA expression. Western analyses and in vitro kinase assays indicate that this inhibition is not due to either down-regulation of STAT3 protein expression nor inactivation of upstream-located JAK1 and JAK2. Blocking the new RNA and protein syntheses antagonized the inhibitory effect of PE on IL-6-activated STAT3, suggesting synthesis of an inhibitory factor(s) is involved. The inhibitory effect of PE on IL-6 activation of STAT3 was also abolished by the tyrosine phosphatase inhibitor sodium vanadate, indicating involvement of protein tyrosine phosphatases. Furthermore, preincubation of the cells with the specific MEK1 inhibitor PD98059 or a dominant negative MEK1 reversed the inhibitory effect of PE, and expression of constitutively activated MEK1 alone abolished IL-6-activated STAT3. Taken together, these data indicate that PE inhibits IL-6 activation of STAT3 in hepatic cells by a p42/44 mitogen-activated protein kinase-dependent mechanism, and tyrosine phosphatases are involved. This inhibitory cross-talk between the alpha(1B)AR and IL-6 signaling pathways implicates the alpha(1B)AR involvement in regulating the IL-6-mediated inflammatory responses.

Components of visual acuity loss in strabismus

Strabismus, the misalignment of the visual axis of one eye relative to that of the other eye, reduces visual acuity in the affected eye. Several processes contributing to that loss are: amblyopia, which results in a chronic acuity loss whether or not the fellow eye is viewing; strabismic deviation, which shifts the image of an acuity target onto more peripheral, and therefore less acute, retina when the fellow eye fixates; interocular suppression and binocular masking, which reduce visibility in the strabismic eye due to neural influences from the other eye. We measured the losses due to these processes in nine small-angle strabismic subjects. Amblyopia reduced acuity by a median of 34% relative to its value in subjects with normal binocular vision, and strabismic deviation produced a loss of 44%. Suppression and masking together reduced acuity by 20%, and therefore had substantially less effect than the other factors.

Balloon angioplasty with intraluminal stenting as the initial treatment modality in aorto-iliac occlusive disease

PURPOSE

We retrospectively evaluated balloon angioplasty with intraluminal stenting to define applicability, early results, cost, and length of stay.

METHODS

Seventy-three patients underwent 94 aorto-iliac angioplasties with intraluminal stents from October 1991 through July 1993. All had disabling claudication or rest ischemia.

RESULTS

Mean follow-up was 10.2 months and was 90.4% complete. Ninety percent of procedures were immediately successful. There were no deaths within 30 days of surgery. Complications occurred in 13%. The ankle:brachial indices improved in all groups. Functional class improved in all groups. In class 4, limb salvage or a benefit on level of amputation was universal. Length of stay ranged 33% to 82% less than when aorto-iliac or aortofemoral bypass were undertaken (diagnosis-related group 39.25). Hospital charges for stent procedures ranged 25% to 66% less than for aorto-iliac or aortofemoral bypass (diagnosis-related group 39.25).

CONCLUSION

The procedure is widely applicable, with an apparent initial advantage in mortality, morbidity, charges, and length of stay. Durability is unproven.