Prospect of Gum Arabic-Cocoliposome Matrix to Encapsulate Curcumin for Oral Administration

Curcumin is an antioxidant that can effectively eliminate free radicals. However, as its oral bioavailability is low, an effective delivery method is required. Phospholipid-based liposomes can encapsulate lipophilic drugs, such as curcumin, while liposome, cholesterol, and gum Arabic (GA) can enhance the internal and external stability of drug membranes. This present study used concentrations of cholesterol (Cchol) and GA (CGA), ranging from 0 to 10, 20, 30, and 40% as well as 0 to 5, 10, 15, 20, 30, and 40%, respectively, to encapsulate curcumin in a GA-cocoliposome (CCL/GA) matrix and test its efficacy in simulated intestinal fluid (SIF) and simulated gastric fluid (SGF). The absence of new characteristic peaks in the Fourier transform infrared (FTIR) spectra results indicate the presence of non-covalent interactions in the CCL/GA encapsulation. Furthermore, increasing the Cchol decreased the encapsulation efficiency (EE), loading capacity (LC), and antioxidant activity (IR) of the CCL/GA encapsulation but increased its release rate (RR). Conversely, increasing CGA increased its EE and IR but decreased its LC and RR. The two conditions applied confirmed this. Liposomal curcumin had the highest IR in SIF (84.081%) and the highest RR in SGF (0.657 ppm/day). Furthermore, liposomes loaded with 10% Cchol and 20% CGA performed best in SIF, while those loaded with 10% Cchol and 30% CGA performed best in SGF. Lastly, the CCL/GA performed better in SIF than SGF.

Random forest-based simultaneous and proportional myoelectric control system for finger movements

A classification scheme for myoelectric control systems (MCS) cannot mimic complex hand movements. This paper presents simultaneous and proportional MCS by estimating the angles of fourteen finger joints using time-domain feature extraction and random forest. The experimental results show that the best feature was the root mean square (RMS). Furthermore, the random forest attained an average coefficient of determination (R2) of 0.85 compared to other regressors which perform below 0.75. The ANOVA tests indicated that the performance of the proposed system was significantly different. Therefore, the proposed system will be the best option for real-time MCS applications in the future.

Development of Galectin-3 Targeting Drugs for Therapeutic Applications in Various Diseases

Galectin-3 (Gal3) is one of the most studied members of the galectin family that mediate various biological processes such as growth regulation, immune function, cancer metastasis, and apoptosis. Since Gal3 is pro-inflammatory, it is involved in many diseases that are associated with chronic inflammation such as cancer, organ fibrosis, and type 2 diabetes. As a multifunctional protein involved in multiple pathways of many diseases, Gal3 has generated significant interest in pharmaceutical industries. As a result, several Gal3-targeting therapeutic drugs are being developed to address unmet medical needs. Based on the PubMed search of Gal3 to date (1987-2023), here, we briefly describe its structure, carbohydrate-binding properties, endogenous ligands, and roles in various diseases. We also discuss its potential antagonists that are currently being investigated clinically or pre-clinically by the public and private companies. The updated knowledge on Gal3 function in various diseases could initiate new clinical or pre-clinical investigations to test therapeutic strategies, and some of these strategies could be successful and recognized as novel therapeutics for unmet medical needs.

Current trends and future perspective of probiotic yeasts research in Indonesia

Indonesia is a mega biodiversity country with various local wisdom, including the enormous variety of fermented foods and beverages. Indonesian researchers have conducted an intensive study to understand the diversity of microbes on those fermented products, one of which shows probiotic properties. Compared to that lactic acid bacteria, the study on probiotic yeasts is less explored. Probiotic yeast isolates are commonly isolated from traditional Indonesian fermented products. Saccharomyces, Pichia, and Candida are among Indonesia's most popular genera of probiotic yeasts, primarily applied in poultry and human health. The exploration of functional probiotic characteristics, such as antimicrobial, antifungal, antioxidant, and immunomodulator, has been widely reported from these local probiotic yeast strains. In vivo studies in a model organism such as mice conclude the prospective functional probiotic characteristics of the yeast isolates. Employment of current technology, such as omics, is essential in elucidating those functional properties. Advanced research and development of probiotic yeasts in Indonesia are gaining significant attention currently. For instance, probiotic yeasts-mediated fermentation in the production of kefir and kombucha are among the trend with promising economic value. The future trends of probiotic yeasts research in Indonesia are discussed in this review to give valuable sight into the application of indigenous probiotic yeasts in various fields.

An Empirical Study on the Use of Digital Technologies to Achieve Cost-Effectiveness in Healthcare Management

Objectives: Healthcare cost reduction is one of the major challenges of the current era. This study was based on the general system theory-based view to assess the significance of sensing communication technologies and processing actuation technologies in improving healthcare quality, leading to cost reduction. Moreover, the contingent rule of healthcare supply chain management in enhancing the influence of improved quality on healthcare cost reduction was also empirically tested. Methods: The sample of the study comprised 337 middle and senior healthcare managers employed in various government and private hospitals and health institutions in Jakarta, Indonesia. The administrative departments of each hospital and health institution was visited to take their consent to conduct this survey at their clinical and non-clinical departments. The data collected was analyzed using SmartPLS ver. 4 software. Results: Results reveal a significant direct and indirect influence of sensing communication technologies and processing actuation technologies on achieving cost-effectiveness in the healthcare sector, in the presence of perceived quality improvement as a mediator. However, the strength of the associations varied and was based on highly reliable and familiar nature of sensing communication technologies compared to processing actuation technologies which were emerging and gaining popularity in recent years. Conclusion: Considering the healthcare cost as a critical factor based on limited resources in emerging economies, healthcare institutions/centers should use digital technologies to achieve cost-effectiveness for providing healthcare facilities in the industry 4.0 era.

CO2 Sequestration Using Sodium Hydroxide and Its Utilization for Chlorella sorokiniana Biomass Production

Chlorella is widely used for its fast growth rate and easy cultivation with 14–30% lipid content and 36–59% dry weight. Thus, sodium hydroxide is used to increase carbon consumption, biomass, and metabolites productions in microalgae. This study was conducted to observe the effect of sodium hydroxide addition on biomass and metabolites  production in photoautotrophic cultivated Chlorella sorokiniana. Microalgae C.sorokiniana (LIPI12-Al016) was obtained from the culture collection of Microalgae and Bioprocess Engineering Research Group laboratory, National Research and Innovation Agency. Then, the microalgae were cultivated in media with various concentrations of sodium hydroxide. Biomass production was measured by gravimetry, and carbon consumption was measured by acid-alkalimetry. Sodium hydroxide 60 mM gave the best growth, maximizing average carbon consumption to 691.8 mg.L-1 and biomass production to 598.3 mg.L-1. The utilization of NaOH in the medium did not increase the metabolites content, except for protein. Carbohydrate was the dominant metabolite among the others. Fatty acids profile mainly composed of C16 and C18 fatty acids, which are favorable for biodiesel production. These results gave an overview of the potency of microalgae C. sorokiniana as a CO2 mitigation agent and alternative sources of energy and nutrition.

SARS-CoV-2 Antibody Neutralization Assay Platforms Based on Epitopes Sources: Live Virus, Pseudovirus, and Recombinant S Glycoprotein RBD

The high virulent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus that emerged in China at the end of 2019 has generated novel coronavirus disease, coronavirus disease 2019 (COVID-19), causing a pandemic worldwide. Every country has made great efforts to struggle against SARS-CoV-2 infection, including massive vaccination, immunological patients’ surveillance, and the utilization of convalescence plasma for COVID-19 therapy. These efforts are associated with the attempts to increase the titers of SARS-CoV-2 neutralizing Abs (nAbs) generated either after infection or vaccination that represent the body’s immune status. As there is no standard therapy for COVID-19 yet, virus eradication will mainly depend on these nAbs contents in the body. Therefore, serological nAbs neutralization assays become a requirement for researchers and clinicians to measure nAbs titers. Different platforms have been developed to evaluate nAbs titers utilizing various epitopes sources, including neutralization assays based on the live virus, pseudovirus, and neutralization assays utilizing recombinant SARS-CoV-2 S glycoprotein receptor binding site, receptor-binding domain. As a standard neutralization assay, the plaque reduction neutralization test (PRNT) requires isolation and propagation of live pathogenic SARS-CoV-2 virus conducted in a BSL-3 containment. Hence, other surrogate neutralization assays relevant to the PRNT play important alternatives that offer better safety besides facilitating high throughput analyses. This review discusses the current neutralization assay platforms used to evaluate nAbs, their techniques, advantages, and limitations.

Treatment prioritization and risk stratification of head and neck cancer during COVID-19 pandemic: A systematic review

INTRODUCTION

Treatment of head and neck cancer patients amidst the COVID-19 pandemic is challenging, whereas prolonged treatment initiation in head and neck squamous cell carcinoma may increase mortality and likelihood of recurrence. Special attention is needed to ensure safe and appropriate care of these patients. This article aims to review and discuss existing research on treatment prioritization and risk stratification of head and neck cancer patients during the pandemic.

MATERIALS AND METHODS

The authors conducted literature search in three databases (PubMed, Cochrane, and Clinical Key) on July 15th, 2020. The keywords were ("Head and Neck Mucosal Malignancy" OR "Head and Neck Cancer") AND ("Management" OR "Head and Neck Surgery") AND ("COVID-19" OR "Pandemic"). The inclusion criteria were cancer in adult patients, published from 2020 in English, and with available access to full text. The exclusion criteria were comments, letters, and case reports. The articles were critically appraised using the Centre of Evidence-based Medicine (CEBM), University of Oxford and Duke University. The literature search strategy is illustrated using Preferred Reporting Items for Systematic review and meta-analysis (PRISMA) flow diagram.

RESULTS

A total of 150 articles were identified; 21 articles were gathered from Clinical Key, 33 from Cochrane, and 96 from Pubmed. After screening abstracts and reviewing the full text, the authors determined five articles met the inclusion criteria. There are several key points of head and neck cancer management in the COVID-19 pandemic. Head and neck cancer management is considered a high-risk procedure; the clinician should use proper personal protective equipment. Before operative treatment, all patients should undergo a PCR test 14 days before surgery. In diagnosing head and neck cancer, laryngoscopy should be considered carefully; and cytology should be preferred instead. Medically Necessary, Time-sensitive (MeNTS) score is recommended for risk stratification and surgery prioritization; it has three domains: procedure, disease, and patient. However, it is not specified to head and neck cancer; therefore, it should be combined with other references. Stanford University Head and Neck Surgery Division Department of Otolaryngology made surgery prioritization into three groups, urgent (should be operated immediately), can be postponed for 30 days, and can be postponed for 30- 90 days. Some urgent cases and should be operated on immediately include cancers involving the airways, decreased renal function, and metastases. For chemoradiation decision to delay or continue should refer to the goal of treatment, current oncologic status, and tolerance to radiation. In terms of patient's follow up, telephone consultation should be maximized.

CONCLUSION

MeNTS scoring combined with Guideline from Department of Otolaryngology at Stanford University prioritizing criteria can be helpful in decision making of stratifying Risk and prioritizing surgery in head and neck cancer management.

The effects of Goldenhar Syndrome on hearing and speech development

Goldenhar syndrome is a congenital abnormality with an incidence of 1 in 5,200 to 26,500 births. This syndrome is characterized by facial asymmetry, ear malformation, and/or defects in the eyes and vertebrae. The hearing disorder manifests as both conductive or sensorineural due to the abnormalities occurring in the inner and outer ear. We report a case of a 1-year-3-month-old child presenting with left anotia and right microtia, severe bilateral conductive hearing loss, and global delayed development. The patient was also found to have a hemifacial microsomia, a secundum atrial septal defect (ASD), and a ventricular septal defect (VSD). The patient was advised to use hearing aids and participate in speech therapy. The management of this Goldenhar syndrome patient should be done comprehensively, appropriate to the abnormalities found to achieve the best result.

Assessing encapsulation of curcumin in cocoliposome: In vitro study

Curcumin has been known and used in the medical and industrial world. One way to improve its stability, bioavailability and its medical applications is using encapsulation method. In this research, we studied cocoliposome (coconut liposome) as the encapsulation material. The encapsulation efficiency (EE), loading capacity (LC), release rate (RR), as well as the free radical scavenging activity, measured by inhibition ratio (IR), of curcumin in encapsulation product were studied on varying cholesterol compositions and in simulated gastric fluid (SGF, pH 1.2) and simulated intestinal fluid (SIF, pH 7.4) conditions. We found that curcumin encapsulation in cocoliposome (CCL) formulation was influenced by cholesterol composition and pH conditions. The EE, LC and free radical scavenging activity diminished under both the SIF and SGF conditions when the cholesterol concentration enhanced. However, the RR increased as the cholesterol intensified. The condition to acquire the most favorable encapsulation parameter values was at 10% cholesterol composition. Furthermore, the IR results at 10% cholesterol concentration of CCL was 67.70 and 82.13% in SGF and SIF milieu, respectively. The CCL formulation thrived better under SIF conditions for free radical scavenging activities.

Subject-independent Classification on Brain-Computer Interface using Autonomous Deep Learning for finger movement recognition

The degradation of the subject-independent classification on a brain-computer interface is a challenging issue. One method mostly taken to overcome this problem is by collecting as many subjects as possible and then training the system across all subjects. This article introduces streaming online learning called autonomous deep learning (ADL) to classify five individual fingers based on electroencephalography (EEG) signals to overcome the issue above. ADL is a deep learning architecture that can construct its structure by itself through streaming learning and adapt its structure to the changes occurring in the input. In this article, the input of ADL is a common spatial pattern (CSP) extracted from the EEG signal of healthy subjects. The experimental results on the subject-dependence classification across four subjects using 5fold cross-validation show that that ADL achieved the classification accuracy of around 77%. This performance was excellent compared to a random forest (RF) and a convolutional neural network (CNN). They achieved accuracies of about 53% and 72%, respectively. On the subject-independent classification, ADL outperforms CNN by resulting stable accuracies for both training and testing, different from CNN that experience accuracy degradation to approximately 50%. These results imply that ADL is a promising machine learning in dealing with the issue in the subject-independent classification.

A Novel Mechanism for Nitrosative Stress Tolerance Dependent on GTP Cyclohydrolase II Activity Involved in Riboflavin Synthesis of Yeast

The biological functions of nitric oxide (NO) depend on its concentration, and excessive levels of NO induce various harmful situations known as nitrosative stress. Therefore, organisms possess many kinds of strategies to regulate the intracellular NO concentration and/or to detoxify excess NO. Here, we used genetic screening to identify a novel nitrosative stress tolerance gene, RIB1, encoding GTP cyclohydrolase II (GTPCH2), which catalyzes the first step in riboflavin biosynthesis. Our further analyses demonstrated that the GTPCH2 enzymatic activity of Rib1 is essential for RIB1-dependent nitrosative stress tolerance, but that riboflavin itself is not required for this tolerance. Furthermore, the reaction mixture of a recombinant purified Rib1 was shown to quench NO or its derivatives, even though formate or pyrophosphate, which are byproducts of the Rib1 reaction, did not, suggesting that the reaction product of Rib1, 2,5-diamino-6-(5-phospo-d-ribosylamino)-pyrimidin-4(3 H)-one (DARP), scavenges NO or its derivatives. Finally, it was revealed that 2,4,5-triamino-1H-pyrimidin-6-one, which is identical to a pyrimidine moiety of DARP, scavenged NO or its derivatives, suggesting that DARP reacts with N₂O₃ generated via its pyrimidine moiety.

Adaptive myoelectric pattern recognition for arm movement in different positions using advanced online sequential extreme learning machine

The performance of the myoelectric pattern recognition system sharply decreases when working in various limb positions. The issue can be solved by cumbersome training procedure that can anticipate all possible future situations. However, this procedure will sacrifice the comfort of the user. In addition, many unpredictable scenarios may be met in the future. This paper proposed a new adaptive myoelectric pattern recognition using advance online sequential extreme learning (AOS-ELM) for classification of the hand movements to five different positions. AOS-ELM is an improvement of OS-ELM that can verify the adaptation validity using entropy. The proposed adaptive MPR was able to classify eight different classes from eleven subjects by accuracy of 95.42 % using data from one position. After learning the data from whole positions, the performance of the proposed system is 86.13 %. This performance was better than the MPR that employed original OS-ELM, but it was worse than the MPR that utilized the batch classifiers. Nevertheless, the adaptation mechanism of AOS-ELM is preferred in the real-time application.

Evaluation of extreme learning machine for classification of individual and combined finger movements using electromyography on amputees and non-amputees

The success of myoelectric pattern recognition (M-PR) mostly relies on the features extracted and classifier employed. This paper proposes and evaluates a fast classifier, extreme learning machine (ELM), to classify individual and combined finger movements on amputees and non-amputees. ELM is a single hidden layer feed-forward network (SLFN) that avoids iterative learning by determining input weights randomly and output weights analytically. Therefore, it can accelerate the training time of SLFNs. In addition to the classifier evaluation, this paper evaluates various feature combinations to improve the performance of M-PR and investigate some feature projections to improve the class separability of the features. Different from other studies on the implementation of ELM in the myoelectric controller, this paper presents a complete and thorough investigation of various types of ELMs including the node-based and kernel-based ELM. Furthermore, this paper provides comparisons of ELMs and other well-known classifiers such as linear discriminant analysis (LDA), k-nearest neighbour (kNN), support vector machine (SVM) and least-square SVM (LS-SVM). The experimental results show the most accurate ELM classifier is radial basis function ELM (RBF-ELM). The comparison of RBF-ELM and other well-known classifiers shows that RBF-ELM is as accurate as SVM and LS-SVM but faster than the SVM family; it is superior to LDA and kNN. The experimental results also indicate that the accuracy gap of the M-PR on the amputees and non-amputees is not too much with the accuracy of 98.55% on amputees and 99.5% on the non-amputees using six electromyography (EMG) channels.

A robust myoelectric pattern recognition using online sequential extreme learning machine for finger movement classification

A robust myoelectric pattern-recognition-system requires a system that should work in the real application as good as in the laboratory. However, this demand should be handled properly and rigorously to achieve a robust myoelectric system. Electrode shift is an issue that usually emerges when dealing with robustness issue. In daily life, the placement of electrodes becomes a significant issue that can downgrade the performance of the system. This paper proposed a new way to overcome the robustness issue by conducting an update to the system to anticipate changes in the future such as electrode shift, improvement in muscle strength or any other issue. Such update will be used to generate an adaptation. The adaptation is done according to the user's need by employing an online sequential extreme learning (OS-ELM) to learn the training data chunk by chunk. OS-ELM enables the myoelectric system to learn from a small number of data to avoid cumbersome training process. The day-to-day experiment shows that the proposed system can maintain its performance on average accuracy around 85% whereas the non-adaptive system could not.

A novel upper limb rehabilitation system with self-driven virtual arm illusion

This paper proposes a novel upper extremity rehabilitation system with virtual arm illusion. It aims for fast recovery from lost functions of the upper limb as a result of stroke to provide a novel rehabilitation system for paralyzed patients. The system is integrated with a number of technologies that include Augmented Reality (AR) technology to develop game like exercise, computer vision technology to create the illusion scene, 3D modeling and model simulation, and signal processing to detect user intention via EMG signal. The effectiveness of the developed system has evaluated via usability study and questionnaires which is represented by graphical and analytical methods. The evaluation provides with positive results and this indicates the developed system has potential as an effective rehabilitation system for upper limb impairment.

Swarm-wavelet based extreme learning machine for finger movement classification on transradial amputees

The use of a small number of surface electromyography (EMG) channels on the transradial amputee in a myoelectric controller is a big challenge. This paper proposes a pattern recognition system using an extreme learning machine (ELM) optimized by particle swarm optimization (PSO). PSO is mutated by wavelet function to avoid trapped in a local minima. The proposed system is used to classify eleven imagined finger motions on five amputees by using only two EMG channels. The optimal performance of wavelet-PSO was compared to a grid-search method and standard PSO. The experimental results show that the proposed system is the most accurate classifier among other tested classifiers. It could classify 11 finger motions with the average accuracy of about 94 % across five amputees.

Adipose-derived stromal cells promote allograft tolerance induction

Amputations and unsalvageable injuries with devastating tissue loss are common in the combat wounded. Reconstructive transplantation in the civilian setting using vascular composite allotransplants (VCAs) with multiple tissues (skin, muscle, nerve, bone) combined with long-term multidrug immunosuppression has been encouraging. However, skin rejection remains a critical complication. Adipose-derived stromal/stem cells (ASCs) are easily obtained from normal individuals in high numbers, precluding ex vivo expansion. The reparative function and paracrine immunomodulatory capacity of ASCs has gained considerable attention. The present study investigated whether ASCs facilitate long-term skin allograft survival. ASCs were isolated from fresh human subcutaneous adipose lipoaspirate. Full-thickness skin grafts from BALB/c mice were transplanted onto the dorsal flanks of C57BL/6 mice treated with five doses of anti-CD4/CD8 monoclonal antibodies (10 mg/kg) on days 0, +2, +5, +7, and +14 relative to skin grafting. A single nonmyeloablative low dose of busulfan (5 mg/kg) was given on day +5. Seven days after skin transplantation, ASCs (3×10(6)) were infused i.v. with or without donor bone marrow cells (BMCs; 5×10(5)). ASC+BMC coinfusion with minimal conditioning led to stable lymphoid and myeloid macrochimerism, deletion of alloreactive T cells, expansion of regulatory T cells, and long-term allograft survival (>200 days). ASCs constitutively produced high levels of anti-inflammatory/immunoregulatory factors such as prostaglandin E2, indoleamine 2,3-dioxygenase, APO-1/Fas (CD95), and programmed cell death-1 ligand-2. These findings serve as a foundation for developing a translational advanced VCA protocol, embodying both ASCs and low-dose donor BMCs, in nonhuman primates, with the goal of enhancing functional outcomes and eliminating the complications associated with long-term immunosuppression.

Comparative analysis of gene transcripts for cell signaling receptors in bone marrow-derived hematopoietic stem/progenitor cell and mesenchymal stromal cell populations

Introduction

Knowing the repertoire of cell signaling receptors would provide pivotal insight into the developmental and regenerative capabilities of bone marrow cell (BMC)-derived hematopoietic stem/progenitor cells (HSPCs) and bone marrow mesenchymal stromal cells (BMMSCs).

Methods

Murine HSPCs were enriched from fluorescence-activated cell sorting (FACS)-sorted Lin^–c-Kit⁺Sca-1⁺ BMCs isolated from the tibia and femoral marrow compartments. Purified BMMSCs (CD73⁺, CD90⁺, CD105⁺, and CD45^–, CD34^–, CD31^–, c-Kit^–) with extensive self-renewal potential and multilineage differentiation capacity (into different mesodermal cell lineages including osteocytes, chrondrocytes, adipocytes) were derived from adherent BMC cultures after CD45⁺ cell depletion. Adherent colony-forming cells were passaged two to three times and FACS analysis was used to assess cell purity and validate cell-specific surface marker phenotype prior to experimentation. Gene transcripts for a number of cell signaling molecules were assessed using a custom quantitative real-time RT-PCR low-density microarray (94 genes; TaqMan^® technology).

Results

We identified 16 mRNA transcripts that were specifically expressed in BMC-derived HSPC (including Ptprc, c-Kit, Csf3r, Csf2rb2, Ccr4, Cxcr3 and Tie-1), and 14 transcripts specifically expressed in BMMSCs (including Pdgfra, Ddr2, Ngfr, Mst1r, Fgfr2, Epha3, and Ephb3). We also identified 27 transcripts that were specifically upregulated (≥2-fold expression) in BMMSCs relative to HSPCs (Axl, Bmpr1a, Met, Pdgfrb, Fgfr1, Mertk, Cmkor1, Egfr, Epha7, and Ephb4), and 19 transcripts that were specifically upregulated in HSPCs relative to BMMSCs (Ccr1, Csf1r, Csf2ra, Epor, IL6ra, and IL7r). Eleven transcripts were equally expressed (<2-fold upregulation) in HSPCs and BMMSCs (Flt1, Insr, Kdr, Jak1, Agtrl1, Ccr3, Ednrb, Il3ra, Hoxb4, Tnfrsf1a, and Abcb1b), whilst another seven transcripts (Epha6, Epha8, Musk, Ntrk2, Ros1, Srms, and Tnk1) were not expressed in either cell population.

Conclusions

We demonstrate that besides their unique immunophenotype and functional differences, BMC-derived HSPCs and BMMSCs have different molecular receptor signaling transcript profiles linked to cell survival, growth, cell differentiation status, growth factor/cytokine production and genes involved in cell migration/trafficking/adhesion that may be critical to maintain their pluripotency, plasticity, and stem cell function.

Amnion-derived multipotent progenitor cells support allograft tolerance induction

Donor-specific immunological tolerance using high doses of bone marrow cells (BMCs) has been demonstrated in mixed chimerism-based tolerance induction protocols; however, the development of graft versus host disease remains a risk. Here, we demonstrate that the co-infusion of limited numbers of donor unfractionated BMCs with human amnion-derived multipotent progenitor cells (AMPs) 7 days post-allograft transplantation facilitates macrochimerism induction and graft tolerance in a mouse skin transplantation model. AMPs + BMCs co-infusion with minimal conditioning led to stable, mixed, multilineage lymphoid and myeloid macrochimerism, deletion of donor-reactive T cells, expansion of CD4(+)CD25(+)Foxp3(+) regulatory T cells (T(regs)) and long-term allograft survival (>300 days). Based on these findings, we speculate that AMPs maybe a pro-tolerogenic cellular therapeutic that could have clinical efficacy for both solid organ and hematopoietic stem cell transplant applications.

Two-channel surface electromyography for individual and combined finger movements

This paper proposes the pattern recognition system for individual and combined finger movements by using two channel electromyography (EMG) signals. The proposed system employs Spectral Regression Discriminant Analysis (SRDA) for dimensionality reduction, Extreme Learning Machine (ELM) for classification and the majority vote for the classification smoothness. The advantage of the SRDA is its speed which is faster than original LDA so that it could deal with multiple features. In addition, the use of ELM which is fast and has similar classification performance to well-known SVM empowers the classification system. The experimental results show that the proposed system was able to recognize the individual and combined fingers movements with up to 98 % classification accuracy by using only just two EMG channels.

Pattern of congenital heart diseases

This prospective observational study was done to find out the frequency of various forms of congenital heart disease (CHD) diagnosed by echocardiography. During the study period (January 2002 to December 2005) 2050 patients were screened by echocardiography. All patients were evaluated by cardiologists and had chest radiograph, electrocardiogram and echocardiography. Total 2050 patients were studied and among them 1071 had congenital heart disease. Male was 561(52.38%) and female was 510(47.62%). Atrial septal defect (ASD) was 374(34.92%), ventricular septal defect (VSD) was 318(29.69%), patent ductus arteriosus (PDA) 83(7.75%), pulmonary stenosis (PS) 58(5.42%), tetralogy of Fallot 162(15.13%), transposition of great vessels (TGA) 16(1.49%), Ebstein anomaly 5(0.4%), coarctation of aorta 1(0.09%) and single ventricle 2(0.19%). This distribution is more or less similar to that reported in studies at home and abroad. In this study atrial septal defect (ASD) was the commonest in acyanotic CHD and tetralogy of Fallot was the commonest cyanotic CHD.

Clinical and angiographic profile of congenital anomalous origin of coronary arteries

Coronary artery anomalies were found in 24(0.6%) patients undergoing coronary arteriography at University Cardiac Center, Bangabandhu Sheikh Mujib Medical University, Dhaka from 2004 to 2007. Of the 24 patient, 21(87.5%) had anomalies of origin and distribution and 3(12.5%) had coronary artery fistulae. Most coronary anomalies did not result in signs, symptoms or complications and usually were discovered as an incidental finding at the time of catheterization. Most of them were benign anomalies: i) separate origin of left anterior descending and circumflex from sinus of valsalva; ii) ectopic origin of circumflex from right sinus of valsalva; iii) Anomalous origin of left main coronary artery from right coronary artery; iv) anomalous coronary origin from ascending aorta; v) absent left circumflex; vi) double right coronary artery; vii) small coronary artery fistula. These anomalies may be associated with potentially serious sequelae such as angina pectoris, myocardial infarction, syncope, cardiac arrhythmias, congestive heart failure, or sudden death. In this study large coronary artery fistula was found as potentially serious anomaly. So coronary artery anomalies require accurate recognition for the appropriate management of the patients.

Outcome of pregnancy in patients with congenital heart diseases

This prospective study was conducted to evaluate the outcome of pregnancies in women with congenital heart diseases. In this study 50 pregnant women age between 20-45 years with congenital heart diseases were included. Twenty two (44%) were presented with atrial septal defect, 12(24%) with ventricular septal defect, 5(10%) were with patent ductus arteriosus, 6(12%) with Fallot's tetralogy, 2(4%) with pulmonary stenosis, 2(4%) with Eisenmenger syndrome, 1(2%) with dextrocardia. Shortness of breath (60%) was the main presenting complaint. Normal vaginal delivery (52%) was done in majority of cases. Spontaneous abortion occurred in 16% of pregnancies. Major complications were heart failure 16%, arrhythmias 21%, cardiovascular mortality 4%, preeclampsia 4%, and eclampsia 2%. Premature birth 16%, fetal demise 4%, neonatal death 2% and cardiac anomaly at birth 2% were also observed. The outcome of pregnancy in women with congenital heart diseases is favourable with considerable maternal and neonatal complications.

Valvular heart disease in pregnancy: maternal and fetal outcome

The aim of this study was to evaluate the maternal and fetal outcome of pregnancy in Valvular Heart Disease (VHD). A better understanding of the effects of valvular abnormalities on pregnancy outcome is of value for risk assessment and the design of a therapeutic plan from the available information of a series of patient. A multicenter prospective study was carried out over a period of 5 years (2005-2009) involving 60 pregnant patients with valvular heart disease. Thirty eight patients (64%) had single valve involvement and mitral stenosis was the most predominant lesion (50%). Ten patients (16.7%) had undergone interventional and surgical correction prior to the pregnancy. Fourteen (24%) patients were identified as a NYHA class III-IV. Women with VHD had 8.35% pulmonary edema, 15.03% developed different types arrhythmia. The incidence of preterm birth and small for gestational age newborn was 11.69% and 13.36% respectively. There was one (1.67%) maternal death. Pregnancy in women with valvular heart disease is associated with remarkable unfavourable effect on maternal and fetal outcome which are related to severity of disease.

Heterotopic ossification in complex orthopaedic combat wounds: quantification and characterization of osteogenic precursor cell activity in traumatized muscle

BACKGROUND

Heterotopic ossification frequently develops following high-energy blast injuries sustained in modern warfare. We hypothesized that differences in the population of progenitor cells present in a wound would correlate with the subsequent formation of heterotopic ossification.

METHODS

We obtained muscle biopsy specimens from military service members who had sustained high-energy wartime injuries and from patients undergoing harvest of a hamstring tendon autograft. Plastic-adherent cells were isolated in single-cell suspension and plated to assess the prevalence of colony-forming cells. Phenotypic characteristics were assessed with use of flow cytometry. Individual colony-forming units were counted after an incubation period of seven to ten days, and replicate cultures were incubated in lineage-specific induction media. Immunohistochemical staining was then performed to determine the percentage of colonies that had differentiated along an osteogenic lineage. Quantitative real-time reverse-transcription polymerase chain reaction was used to identify changes in osteogenic gene expression.

RESULTS

Injured patients had significantly higher numbers of muscle-derived connective-tissue progenitor cells per gram of tissue (p < 0.0001; 95% confidence interval [CI], 129,930 to 253,333), and those who developed heterotopic ossification had higher numbers of assayable osteogenic colonies (p < 0.016; 95% CI, 12,249 to 106,065). In the injured group, quantitative real-time reverse-transcription polymerase chain reaction performed on the in vitro expanded progeny of connective-tissue progenitors demonstrated upregulation of COL10A1, COL4A3, COMP, FGFR2, FLT1, IGF2, ITGAM, MMP9, PHEX, SCARB1, SOX9, and VEGFA in the patients with heterotopic ossification as compared with those without heterotopic ossification.

CONCLUSIONS

Our study suggests that the number of connective-tissue progenitor cells is increased in traumatized tissue. Furthermore, wounds in which heterotopic ossification eventually forms have a higher percentage of connective-tissue progenitor cells committed to osteogenic differentiation than do wounds in which heterotopic ossification does not form. The early identification of heterotopic ossification-precursor cells and target genes in severe wounds not only may be an effective prognostic tool with which to assess whether heterotopic ossification will develop in a wound, but may also guide the future development of individualized prophylactic measures.

Angiographic profile in patients with congenital anomalous origin of the coronary arteries

Online: 20 July 2010 DOI: http://dx.doi.org/10.3329/bmrcb.v36i1.5540 Bangladesh Med Res Counc Bull 2010; 36: 39-41

Infusion of Lin- bone marrow cells results in multilineage macrochimerism and skin allograft tolerance in minimally conditioned recipient mice

Donor-specific immunological tolerance using high doses of donor bone marrow cells (BMC) has been demonstrated in mixed chimerism-based tolerance induction protocols; however, the development of graft versus host disease (GVHD) remains a risk. In the present study, we demonstrate that the infusion of low numbers of donor Lin(-) bone marrow cells (Lin(-) BMC) 7 days post allograft transplantation facilitates high level macrochimerism induction and graft tolerance. Full-thickness BALB/c skin allografts were transplanted onto C57BL/6 mice. Mice were treated with anti-CD4 and anti-CD8 mAbs on day 0, +2, +5, +7 and +14 along with low dose busulfan on day +5. A low dose of highly purified Lin(-) BMC from BALB/c donor mice was infused on day +7. Chimerism and clonal cell deletion were evaluated using flow cytometry. Donor-specific tolerance was tested by donor and third-party skin grafting and mixed leukocyte reaction (MLR). Lin(-) BMC infusion with minimal immunosuppression led to stable, mixed, multilineage macrochimerism and long-term allograft survival (>300 days). Mixed donor-recipient macrochimerism was observed. Donor-reactive T cells were clonally deleted and a 130% increase in CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) was observed in the spleen. Tolerant mice subsequently accepted second donor, but not third-party (C3H), skin grafts and recipient splenocytes failed to react with allogeneic donor cells indicating donor-specific immunological tolerance was achieved. We conclude that the infusion of donor Lin(-) BMC without cytoreductive recipient conditioning can induce indefinite survival of skin allografts via mechanisms involving the establishment of a multilineage macrochimeric state principally through clonal deletion of alloreactive T cells and peripherally induced CD4(+)Foxp3(+) Tregs.

Wound trauma mediated inflammatory signaling attenuates a tissue regenerative response in MRL/MpJ mice

Background

Severe trauma can induce pathophysiological responses that have marked inflammatory components. The development of systemic inflammation following severe thermal injury has been implicated in immune dysfunction, delayed wound healing, multi-system organ failure and increased mortality.

Methods

In this study, we examined the impact of thermal injury-induced systemic inflammation on the healing response of a secondary wound in the MRL/MpJ mouse model, which was anatomically remote from the primary site of trauma, a wound that typically undergoes scarless healing in this specific strain. Ear-hole wounds in MRL/MpJ mice have previously displayed accelerated healing and tissue regeneration in the absence of a secondary insult.

Results

Severe thermal injury in addition to distal ear-hole wounds induced marked local and systemic inflammatory responses in the lungs and significantly augmented the expression of inflammatory mediators in the ear tissue. By day 14, 61% of the ear-hole wounds from thermally injured mice demonstrated extensive inflammation with marked inflammatory cell infiltration, extensive ulceration, and various level of necrosis to the point where a large percentage (38%) had to be euthanized early during the study due to extensive necrosis, inflammation and ear deformation. By day 35, ear-hole wounds in mice not subjected to thermal injury were completely closed, while the ear-hole wounds in thermally injured mice exhibited less inflammation and necrosis and only closed partially (62%). Thermal injury resulted in marked increases in serum levels of IL-6, TNFα, KC (CXCL1), and MIP-2α (CXCL2). Interestingly, attenuated early ear wound healing in the thermally injured mouse resulted in incomplete tissue regeneration in addition to a marked inflammatory response, as evidenced by the histological appearance of the wound and increased transcription of potent inflammatory mediators.

Conclusion

These findings suggest that the observed systemic inflammatory response of a severe thermal injury undoubtedly has an adverse effect on wound healing and tissue regeneration.

Balloon mitral valvuloplasty: immediate and short term haemodynamic and clinical outcome

This prospective study was carried out in the Department of Cardiology, University Cardiac Center, Banghabandhu Sheikh Mujib Medical University, Dhaka, to evaluate the short term clinical and haemodynamic outcome of Balloon mitral valvuloplasty in mitral stenosis. Total 100 patients underwent percutaneous mitral commissurotomy out of which 60 cases had pure mitral stenosis and 40 patients had concomitant other nonsignificant valvular disease. Mitral valve dilatation increases in mitral valve area from 0.5+/-0.22 to 1.80+/-0.41 cm2. Mitral valve mean pressure gradient decline from 24.0+/-6.48 mm of Hg to 6.1+/-3.0 mm of Hg: mean left arterial pressure decline from 21.40+/-4.80 mm of Hg to 6.50+/-2.82 mm of Hg (p<0.001). The pulmonary artery systolic pressure decreased from 78.7+/-20.34 mm of Hg to 30.18+/-10.8 mm of Hg (p<0.001). Procedural success, as defined final mitral valve area>1.5 cm2 or>50% increase in area, was achieved in 95% patients. Serious complications occurred in 2(2%) patients and no death occurred in the study. Minor complications such as vasovagal reaction (03%), balloon rupture without sequelae (1%), hypotension, Seizure etc. during the procedure were also noted. Although percutaneous transvenous mistral commissurotomy appears to be effective at relieving the hemodynamic effects of rheumatic mitral stenosis, it is not without risk. In properly selected patients, however, it appears to have low morbidity and mortality. The overall results of this study demonstrate that the short term clinical and haemodynamic outcome of the procedure were excellent and the incidence of related complications were reasonable.

Extracorporeal shock wave therapy suppresses the early proinflammatory immune response to a severe cutaneous burn injury

Following severe burn injury, persistent inflammation perpetuated by surface eschar, bacterial colonisation and neutrophil proteolytic activity can impede normal healing and result in further tissue damage. Extracorporeal shock wave treatment (ESWT) has been shown in the clinical setting to promote the healing of burn and difficult-to-heal wounds; however, the mechanism is unclear. We investigated the role of ESWT on the early proinflammatory response using a severe, full-thickness and highly inflammatory cutaneous burn wound in a murine model. Various wound-healing parameters were measured and leukocyte infiltration quantitated. A panel of 188 candidate genes known to be involved in acute inflammation and wound healing was screened. We show that ESWT of burn wounds 1 hour postwounding significantly blunts polymorphonuclear neutrophil and macrophage infiltration into the wound. ESWT treatment potently attenuates both CC- and CXC-chemokine expression, acute proinflammatory cytokine expression and extracellular matrix proteolytic activity at the wound margin. Given these findings and the clinical success of ESWT, we speculate that ESWT may be a potential therapeutic modality to treat severe wounds wherein excessive inflammatory responses involving increased levels of inflammatory cells, proinflammatory cytokines and proteases may become self-resolving allowing wound healing to progresses by way of normal physiological repair processes.

Severe tissue trauma triggers the autoimmune state systemic lupus erythematosus in the MRL/++ lupus-prone mouse

Tissue damage associated with a severe injury can result in profound inflammatory responses that may trigger autoimmune development in lupus-prone individuals. In this study, we investigated the role of a large full-thickness cutaneous burn injury on the early onset of autoimmune disease in lupus-prone MRL/++ mice. MRL/++ mice (chronic model) exhibit autoimmune symptoms at >70 weeks of age, whereas MRL/-Faslpr mice (acute model) develop autoimmune disease in 17–22 weeks due to a lymphoproliferative mutation. Autoimmune disease developed in MRL/++ mice (4–15 weeks post injury) is manifested by skin lesions, vasculitis, epidermal ulcers, cellular infiltration, splenomegaly, lymphadenopathy, hypergammaglobulinemia, elevated autoantibodies and renal pathologies including proteinuria, glomerulonephritis and immune complex deposition; complications that contribute to reduced survival. Transcription studies of wound margin tissue show a correlation between the pathogenic effects of dysregulated IL-1β, IL-6, TNF-α and PGE2 synthesis during early wound healing and early onset of autoimmune disease. Interestingly, MRL/++ mice with healed wounds (30–40 days post burn) strongly rejected skin isografts. Conversely, skin isografts transplanted onto naive age-matched MRL/++ littermates achieved long-term survival. Collectively, these findings suggest that traumatic injury exacerbates inflammatory skin disease and severe multi-organ pathogenesis in lupus-prone mice.

Low dose busulfan facilitates chimerism and tolerance in a murine model

T cell depletion, sirolimus and "mega" dose donor specific bone marrow (DSBM) infusion promotes stable multilineage chimerism and indefinite survival of skin allografts in completely mismatched mice. The purpose of this study is to determine whether the addition of low dose busulfan can reduce the amount of DSBM required while preserving efficacy. C57BL/6 recipients of BALB/c skin allografts were treated with alphaCD4 and alphaCD8 monoclonal antibodies, DSBM, sirolimus and various doses of busulfan. The kinetics and phenotype of chimerism and the presence of clonal deletion of alloreactive T-cells were defined using flow cytometry. In vitro reactivity was determined using mixed lymphocyte culture. Second skin grafts confirmed the presence of tolerance. All doses of busulfan resulted in engraftment when combined with this regimen using a reduced dose of donor marrow. The level, kinetics and character of chimerism observed were dose related. Chimerism was associated with indefinite allograft acceptance (>200 days). Tolerance was documented both in vitro/in vivo and was associated with clonal deletion. Addition of a single low dose of busulfan to an established tolerance protocol reduced the required DSBM dose by over 80% while still promoting comparable levels of donor chimerism and donor-specific tolerance.

Leishmania promastigote membrane antigen-based enzyme-linked immunosorbent assay and immunoblotting for differential diagnosis of Indian post-kala-azar dermal leishmaniasis

Diagnosis of post-kala-azar dermal leishmaniasis (PKDL), caused by Leishmania donovani, is difficult, as the dermal lesions are of several types and resemble those caused by other skin diseases, especially leprosy. Since the disease generally appears very late after the clinical cure of kala-azar in India, it is also difficult to correlate PKDL with a previous exposure to L. donovani. Very few attempts have been made so far to diagnose PKDL serologically, and the diagnostic methods vary in their sensitivities and specificities. Diagnosis of PKDL through sophisticated PCR methods, although highly sensitive, has limited practical use. We have developed a serodiagnostic method using an enzyme-linked immunosorbent assay to detect specific immunoglobulin (Ig) isotypes and IgG subclass antibodies in the sera of Indian PKDL patients. Our assay, which uses L. donovani promastigote membrane antigens, was 100% sensitive for the detection of IgG and 96.7% specific for the detection of IgG and IgG1. Optical density values for individual patients, however, demonstrated wide variations. Western blot analysis based on IgG reactivity could differentiate patients with PKDL from control subjects, which included patients with leprosy, patients from areas where kala-azar is endemic, and healthy subjects, by the detection of polypeptides of 67, 72, and 120 kDa. The recognition patterns of the majority of serum samples from patients with PKDL were also distinct from those of the serum samples from patients with visceral leishmaniasis (VL), at least for a 31-kDa polypeptide. To further differentiate patients with PKDL from those with active and cured VL, we analyzed the specific titers of the Ig isotypes and IgG subclasses. High levels of IgG, IgG1, IgG2, and IgG3 antibodies significantly differentiated patients with PKDL from patients cured of VL. The absence of antileishmanial IgE and IgG4 in patients with PKDL differentiated these patients from those with active VL. These results imply intrinsic differences in the antibodies generated in the sera from patients with PKDL and VL.

INFLUENCE OF PHOSPHOLIPID COMPOSITION ON THE ADJUVANTICITY AND PROTECTIVE EFFICACY OF LIPOSOME-ENCAPSULATED LEISHMANIA DONOVANI ANTIGENS

In this study, we evaluate the effect of phospholipid on the adjuvanicity and protective efficacy of liposome vaccine carriers against visceral leishmaniasis (VL) in a hamster model. Liposomes prepared with distearyol derivative of L-alpha-phosphatidyl choline (DSPC) having liquid crystalline transition temperature (Tc) 54 C were as efficient as dipalmitoyl (DPPC) (Tc 41 C) and dimyristoyl (DMPC) (Tc 23 C) derivatives in their ability to entrap Leishmania donovani membrane antigens (LAg) and to potentiate strong antigen-specific antibody responses. However, whereas LAg in DPPC and DMPC liposomes stimulated inconsistent delayed type hypersensitivity (DTH) responses, strong DTH was observed with LAg in DSPC liposomes. The heightened adjuvant activity of DSPC liposomes corresponded with 95% protection, with almost no protectivity with LAg in DPPC and DMPC liposomes, 4 mo after challenge with L. donovani. These data demonstrate the superiority of DSPC liposomes for formulation of L. donovani vaccine. In addition, they demonstrate a correlation of humoral and cell-mediated immunity with protection against VL in hamsters.

Targeted T-Cell Depletion or CD154 Blockade Generates Mixed Hemopoietic Chimerism and Donor-Specific Tolerance in Mice Treated with Sirolimus and Donor Bone Marrow

BACKGROUND

The administration of donor specific bone marrow (DSBM) to mice conditioned with antilymphocyte serum (ALS) and sirolimus can result in stable multilineage mixed chimerism and long-term graft survival. This study seeks to determine if either the targeted depletion of CD4 and/or CD8 pos T cells or costimulation blockade can substitute for ALS and preserve the efficacy of this regimen.

METHODS

C57BL/6 recipients of BALB/c skin allografts were treated with DSBM (150 x 10(6) cells), sirolimus (24 mg/kg intraperitonealy), and either ALS or various monoclonal antibodies (alphaCD4, alphaCD8, alphaCD154 alone or in combination). Recipient peripheral blood mononuclear cell (PBMC) depletion, donor chimerism, and deletion of donor reactive T cells were assessed using flow cytometry. The specificity of immunologic nonreactivity and the presence of immunoregulatory activity were assessed through a mixed lymphocyte reaction assay.

RESULTS

The administration of ALS, sirolimus, and DSBM resulted in sustained recipient PBMC depletion, transient chimerism, and prolonged graft survival. The substitution of an equivalent degree and duration of targeted depletion of either CD4 or CD8 pos T cells alone for ALS failed to produce chimerism or prolonged graft survival. In contrast, depletion of both CD4 and CD8 pos T cells resulted in durable multilineage chimerism, indefinite allograft acceptance (>350 days), and donor-specific tolerance to secondary skin grafts. Substitution of alphaCD154 monoclonal antibody for ALS also resulted in a state of mixed chimerism and donor specific tolerance. This tolerant state appears to be maintained at least partially through clonal deletion and suppression.

CONCLUSION

Either combined CD4 and CD8 T-cell depletion or alphaCD154 blockade can effectively substitute for ALS in producing chimerism and tolerance in this model.

A mixed Th1/Th2 response elicited by a liposomal formulation of Leishmania vaccine instructs Th1 responses and resistance to Leishmania donovani in susceptible BALB/c mice

In this study, we have developed a vaccine with Leishmania donovani promastigote membrane antigens (leishmanial antigens (LAg)) encapsulated in a liposome carrier formulated with distearyol (DSPC, transition temperature (Tc) = 54 degrees C) derivative of l-alpha-phosphatidyl choline, for immunizing BALB/c mice against progressive visceral leishmaniasis. This formulation could limit hepatosplenomegaly to almost normal levels and conferred strong levels of protection in both liver and spleen against challenge infection. Immunization with liposomal LAg activated peritoneal macrophages for enhanced leishmanicidal activity in association with NO production, and induced antibody as well as T-cell mediated immune responses. Production of both IFN-gamma and IL-4 by splenic T cells, and serum IgG1 and IgG2a, suggest induction of a mixed Th1/Th2 response following immunization. Experimental challenge corresponded with elevated DTH, and mitogen and antigen specific cellular responses. Increased production of NO and IFN-gamma by spleen cells, and down regulation of IL-4, demonstrate that an initial stimulation of a mixed Th1/Th2 response by vaccination instructs Th1 responses and resistance against a progressive infection by L. donovani.

Characterization of immunoglobulin G and its subclass response to Indian kala-azar infection before and after chemotherapy

Serologic parameters of kala-azar were evaluated by Western blot analysis. Sera from kala-azar patients with confirmed diagnoses were screened for immunoglobulin G (IgG) and IgG subclass-specific reactivity against Leishmania donovani membrane antigen (LAg). Heterogeneous LAg-specific IgG reactivity with numerous proteins with molecular masses ranging from 18 to 190 kDa was observed. Though the individual band patterns were varied, seven polypeptides of approximately 31, 34, 51, 63, 72, 91, and 120 kDa were immunoreactive with all the sera tested from kala-azar patients. The band patterns of the immunoblots of sera from patients after treatment and clinical cure with sodium antimony gluconate revealed a decrease in the frequency of the bands. Still, recognition of the 63- and 120-kDa bands was 100%, and the 55- and 91-kDa fractions were recognized in 93% of the sera from cured individuals. Among the IgG subclasses, IgG1 reacted with the greatest number of polypeptides. The 63-kDa protein was again detected by all of the IgG subclasses of all the sera tested. Other fractions recognized by the subclasses of more than 70% of the serum samples included those of 47, 51, 55, and 78 kDa. Following treatment, 63- and 51-kDa bands were the most reactive with the IgG subclasses. LAg-associated cross-reaction with other reference human antisera revealed a mild reactivity of the 63-kDa polypeptide with some of the serum samples from leprosy, malaria, typhoid, tuberculosis, and healthy controls. Western blot analysis of LAg entrapped in liposomes, strong vaccine candidates against experimental visceral leishmaniasis, revealed a more restricted band pattern. The 63-kDa fraction revealed by all pre- and posttreatment sera showed almost negligible levels of cross-reaction with sera from patients with other diseases or from healthy controls. These observations provide insight into induced immunity during kala-azar infection for future application.

Characterization of Leishmania donovani antigens encapsulated in liposomes that induce protective immunity in BALB/c mice

Leishmania donovani promastigote membrane antigens (LAg) encapsulated in positively charged liposomes have been found to induce very significant levels of protection against experimental visceral leishmaniasis. The protectively immunized animals exhibited profound delayed-type hypersensitivity and antibody responses. The extent of protection induced by the same antigens, however, varied depending on the charge of the vesicles, with maximum induction by positively charged liposomes, followed by neutral liposomes and last negatively charged liposomes. Characterization of LAg and LAg entrapped in liposomes of different charges by Western blot analysis revealed the immunodominance of gp63 in all three vaccine preparations. The strong reactivity of antigens in a restricted antigen profile that included, in addition to gp63, 72-, 52-, 48-, 45-, 39-, and 20-kDa components in neutral and positively charged liposomes contrasted with the reactivity of a greater number of LAg components in negatively charged liposomes. Resistance to visceral leishmaniasis appears to depend on the immunity induced by gp63 and a few select antigens in association with the right liposomes. A striking similarity between the immunogenic profile of partially purified soluble antigens and that of LAg in neutral and positively charged liposomes suggests the potentiality of these antigens in future vaccine studies of L. donovani.

Infectivity and virulence of Leishmania donovani promastigotes: a role for media, source, and strain of parasite

Transformation of promastigotes of Leishmania donovani strain AG83 from amastigotes derived from an infected animal was studied in three media, Schneider's Drosophila medium (SDM), Medium 199 (M199), and biphasic M199 (B-M199) with 10% fetal bovine serum. The media, SDM and B-M199, both supported a more efficient transformation of promastigotes in comparison with M199. Infectivity studies in hamsters and BALB/c mice showed that promastigotes isolated in B-M199 were several folds more infective than those obtained from M199. Comparison of the infectivity and virulence of promastigotes of AG83, with a recent isolate of kala-azar, SL94, harvested under similar conditions, revealed greater infectivity of SL94 for both macrophages and animal models. The present study demonstrates that the medium used for the conversion of amastigotes to promastigotes plays a major role in determining the infectivity of the freshly transformed L. donovani promastigotes in hamsters and BALB/c mice. The source and the strain of the parasite also influence the outcome of L. donovani infection.

Leishmanicidal activity of stearylamine-bearing liposomes in vitro

Liposomes consisting of stearylamine (SA) and egg yolk phosphatidylcholine (PC) were studied for their cytotoxic activity against freshly transformed promastigotes and intracellular amastigotes of Leishmania donovani, the causative agent of visceral leishmaniasis. More than 99% of the parasites of strain AG83 were killed within 60 min by treatment with 22 mol% SA-PC liposomes (132 microg/ml total lipids). This was further confirmed by incubating the liposome-treated promastigotes at 22 C for 96 hr. The killing activity of the liposomes progressively decreased with lowering lipid concentration. However, weak cytotoxic activity was still detected at 6.6 microg/ml lipids. Leishmanicidal activity of the liposomes became stronger with increasing SA content but was reduced with the incorporation of cholesterol in the liposomes. A similar cytotoxic effect was observed on other Indian strains of L. donovani, for example PKDL and DD8, as well as on species such as Leishmania donovani S1, Leishmania donovani infantum, Leishmania tropica, Leishmania amazonensis, and Leishmania mexicana. However, freshly transformed promastigotes appeared to be more susceptible than the ones subcultured. The strong leishmanicidal activity of SA-PC liposomes was also demonstrated toward intracellular L. donovani amastigotes. The SA-bearing vesicles could effectively inhibit the growth and multiplication of the parasites within the macrophages. The cytolytic activity of these liposomes on leishmanial parasites and low toxicity on host macrophages may, thus, find application in the therapy of leishmaniasis.