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Evaluation of repetitive isometric contractions on the heads of triceps brachii muscle during grip force exercise

Ali MA, Sundaraj K, Ahmad RB, Ahamed NU, Islam MA, Sundaraj S

Technol Health Care, 2014;22(4):617-25.
PMID: 24990168 DOI: 10.3233/THC-140833

Normally, surface electromyography electrodes are used to evaluate the activity of superficial muscles during various kinds of voluntary contractions of muscle fiber. The objective of the present study was to investigate the effect of repetitive isometric contractions on the three heads of the triceps brachii muscle during handgrip force exercise.

Matched MeSH terms: Hand Strength/physiology*
Fulltext The effects of forearm position on handgrip strength

Ali Md Nadzalan

Jurnal Sains Sukan & Pendidikan Jasmani, 2013;2(1):2-9.
MyJurnal

This study was conducted to investigate i) while the shoulder was in 180° of flexion and the elbow extended, which of the forearm position (supination, pronation and neutral) can generate the greatest handgrip strength, ii) is there any correlation of the handgrip strength between the dominant hand (right hand) and non-dominant hand (left hand) in each forearm position, and iii) will the dominant hand possessed 10% higher handgrip strength than the non-dominant hand. 100 right handed sedentary active students age 22.20 years old (± 1.03), height 172.83 cm (± 6.37), body mass 68.87 (± 11.52) and grip position 3.77 (± 0.77) were recruited in this study. The result indicated that for both the dominant and non-dominant hand, when the shoulder is in 180˚ flexion of the body with the elbow extended, the greatest grip strength was obtained when the forearm was in neutral position followed by pronation and supination position. Post Hoc analysis showed that for both dominant hand and non-dominant hand, pronation and supination forearm position produced greater strength score compared to supination forearm position (p0.05). In all forearm position, participants were shown to produced significantly greater strength in their dominant hand and all the scores were more than 10% greater compared to when using non-dominant hand. Positive relationships were also found for the strength score between dominant hand and non-dominant hand. As the conclusion, different shoulder, elbow and forearm position can affect handgrip strength.

Matched MeSH terms: Hand; Hand Strength
Fulltext Self-Calibration Algorithm for a Pressure Sensor with a Real-Time Approach Based on an Artificial Neural Network

Almassri AMM, Wan Hasan WZ, Ahmad SA, Shafie S, Wada C, Horio K

Sensors (Basel), 2018 Aug 05;18(8).
PMID: 30081581 DOI: 10.3390/s18082561

This paper presents a novel approach to predicting self-calibration in a pressure sensor using a proposed Levenberg Marquardt Back Propagation Artificial Neural Network (LMBP-ANN) model. The self-calibration algorithm should be able to fix major problems in the pressure sensor such as hysteresis, variation in gain and lack of linearity with high accuracy. The traditional calibration process for this kind of sensor is a time-consuming task because it is usually done through manual and repetitive identification. Furthermore, a traditional computational method is inadequate for solving the problem since it is extremely difficult to resolve the mathematical formula among multiple confounding pressure variables. Accordingly, this paper describes a new self-calibration methodology for nonlinear pressure sensors based on an LMBP-ANN model. The proposed method was achieved using a collected dataset from pressure sensors in real time. The load cell will be used as a reference for measuring the applied force. The proposed method was validated by comparing the output pressure of the trained network with the experimental target pressure (reference). This paper also shows that the proposed model exhibited a remarkable performance than traditional methods with a max mean square error of 0.17325 and an R-value over 0.99 for the total response of training, testing and validation. To verify the proposed model's capability to build a self-calibration algorithm, the model was tested using an untrained input data set. As a result, the proposed LMBP-ANN model for self-calibration purposes is able to successfully predict the desired pressure over time, even the uncertain behaviour of the pressure sensors due to its material creep. This means that the proposed model overcomes the problems of hysteresis, variation in gain and lack of linearity over time. In return, this can be used to enhance the durability of the grasping mechanism, leading to a more robust and secure grasp for paralyzed hands. Furthermore, the exposed analysis approach in this paper can be a useful methodology for the user to evaluate the performance of any measurement system in a real-time environment.

Matched MeSH terms: Hand; Hand Strength
Pixel-based skin colour detection techniques evaluation

Alnned M. Mharib, Mohammad Hamiruce Marhaban, Abdul Rahman Ramli

Pertanika Journal of Science & Technology, 2007;15(2):131-137.
MyJurnal

Skin detection has gained popularity and importance in the computer vision community. It is an essential step for important vision tasks such as the detection, tracking and recognition of face, segmentation of hand for gesture analysis, person identification, as well as video surveillance and filtering of objectionable web images. All these applications are based on the assumption that the regions of the human skin are already located. In the recent past, numerous techniques for skin colour modeling and recognition have been proposed. The aims of this paper are to compile the published pixel-based skin colour detection techniques to describe their key concepts and try to find out and summarize their advantages, disadvantages and characteristic features.

Matched MeSH terms: Hand
Fulltext Objective triceps muscle strength measurement using computerized adaptation

Amalourde A, Vinayaga P, Naveed N, Choon SK, Zaleha O

Med J Malaysia, 2004 Dec;59 Suppl F:8-13.
PMID: 15941154

In our centre the non-availability computerized exercise machines limits the objective monitoring of strength rehabilitation. We undertook this research programme to objectively measure triceps muscle strength by interfacing NORSK-Gym machine with accelerometer and positional transducers to a computer. This data was tabulated and processed using Microsoft Excel. The positional transducer was first calibrated and it showed an excellent Pearson Correlation Coefficients against a standard metric reading (r = 0.9999). Peak Force was used as a test parameter for isotonic triceps muscle strength measurements. The criterion-referenced validity was established as the peak forces measured using the accelerometer and positional transducer demonstrated identical Peak Forces (r = 0.94). Analysis of our mean Peak Force measurements using non-biological force as well as the intra-individual reproducibility demonstrated excellent Pearson Correlation Coefficients (r) = 0.982-0.998 and 0.929-0.972 respectively. This computerized adaptation of the NORSK-Gym machine produced an objective, valid and reproducible triceps muscle strength measurement.

Matched MeSH terms: Hand/physiology*
Fulltext Effects of touch-screen technology usage on the hand skills dataset

Aman NA, Chien CW, Judd J, Daud AZC

Data Brief, 2020 Dec;33:106358.
PMID: 33083507 DOI: 10.1016/j.dib.2020.106358

This data article describes the hand skills of pre-school children between five and six years old from five schools under the Ministry of Education Malaysia. These data may be used in a journal article later to show the effects of touch-screen technology usage on hand skills of pre-school children. Demographic characteristics, hand skills ability and frequency of touch-screen technology usage data that was collected from August to September 2019. These data may be used in a future systematic review, meta-analysis and meta-regression analysis to conclude the effects of touch-screen technology usage on children's hand skills. Parents, teachers and health practitioners may refer to these data to note the effects of touch-screen technology usage on hand skills of pre-school children.

Matched MeSH terms: Hand
Fulltext Plasmodium knowlesi malaria: current research perspectives

Amir A, Cheong FW, de Silva JR, Liew JWK, Lau YL

Infect Drug Resist, 2018;11:1145-1155.
PMID: 30127631 DOI: 10.2147/IDR.S148664

Originally known to cause simian malaria, Plasmodium knowlesi is now known as the fifth human malaria species. Since the publishing of a report that largely focused on human knowlesi cases in Sarawak in 2004, many more human cases have been reported in nearly all of the countries in Southeast Asia and in travelers returning from these countries. The zoonotic nature of this infection hinders malaria elimination efforts. In order to grasp the current perspective of knowlesi malaria, this literature review explores the different aspects of the disease including risk factors, diagnosis, treatment, and molecular and functional studies. Current studies do not provide sufficient data for an effective control program. Therefore, future direction for knowlesi research is highlighted here with a final aim of controlling, if not eliminating, the parasite.

Matched MeSH terms: Hand Strength
Contrast sensitivity is associated with frailty

Amir NN, Kamaruzzaman SB, Effendi-Tenang I, Jamaluddin M, Tan MP, Ramli N, et al.

Eur Geriatr Med, 2021 Apr;12(2):313-319.
PMID: 33486745 DOI: 10.1007/s41999-021-00450-2

PURPOSE: Using data from the Malaysian Elders Longitudinal Research (MELoR), this study investigated the association between visual function (visual acuity and contrast sensitivity) and frailty in a group of urban-dwelling older adults.
METHODS: This was a cross-sectional study. 1332 participants aged ≥ 55 years were selected by random sampling from the parliamentary electoral register. Only 1274 participants completed the frailty assessment and 1278 participants completed the contrast sensitivity assessment. Impaired vision was defined as a Snellen visual acuity of worse than 6/12 in the better eye. Poor contrast sensitivity was defined as a score on the Pelli Robson chart of lower than 1.65. Frailty was defined with the Fried's phenotype criteria. Inter-group comparisons were determined with the independent T-test for continuous variables and the Pearson's Chi-squared test for categorical variables. The odds ratio (OR) with 95% confidence interval (CI) was used to evaluate the cross-sectional association between frailty and visual function.
RESULTS: The mean age of participants was 68.8 ± 7.5 years, of which 58.1% (774) were women. Impaired vision and poor contrast sensitivity were present in 187 (14%) and 271 (21.2%) subjects respectively. 73 (5.8%) individuals were classified as frail, 1161 (91.0.%) pre-frail, and 40 (2.8%) non-frail. There was no significant difference in frailty phenotypes between those with good and impaired vision (p = 0.241). Fried's component of handgrip strength, gait speed and exhaustion were significantly better in those with good visual function (p

Matched MeSH terms: Hand Strength
Fulltext Handedness of Malaysian undergraduate dental students and its impact on perceived difficulty in clinical trainingin dentistry

Amiruzehan Kassim, Raja Nur Adilah Raja Abdul Rahman, Mohd Faizal Hafez Hidayat, Budi Aslinie Md Sabri

Compendium of Oral Science, 2016;3(1):25-32.
MyJurnal

Objectives: To assess the prevalence of handedness and its impact on the perceived difficulty in clinical training amongst undergraduate dental students in Malaysia. Materials and Methods: A cross-sectional survey using a self-administered questionnaire was conducted in 5 dental schools around the Klang Valley. Samples consisted of year 4 and year 5 clinical undergraduate dental students. Information on the socio-demographic data, the determination of handedness and assesment of perceived difficulty in carrying out certain clinical procedures were collected. Results: A total sample of 347 participants of which 76.9% were females was obtained. The distribution of year 4 and year 5 students in the sample were equal. Eighty five percent of the samples were right-handed, 9.5% were ambidextrous and 5.5% were left-handed. Statistically significant difference was found between handedness groups for the combined clinical procedures variable: F (2.100), P

Matched MeSH terms: Hand
Fulltext Advances in Antigenic Peptide-Based Vaccine and Neutralizing Antibodies against Viruses Causing Hand, Foot, and Mouth Disease

Anasir MI, Poh CL

Int J Mol Sci, 2019 Mar 13;20(6).
PMID: 30871133 DOI: 10.3390/ijms20061256

Hand, foot, and mouth disease (HFMD) commonly produces herpangina, but fatal neurological complications have been observed in children. Enterovirus 71 (EV-A71) and Coxsackievirus 16 (CV-A16) are the predominant viruses causing HFMD worldwide. With rising concern about HFMD outbreaks, there is a need for an effective vaccine against EV-A71 and CV-A16. Although an inactivated vaccine has been developed against EV-A71 in China, the inability of the inactivated vaccine to confer protection against CV-A16 infection and other HFMD etiological agents, such as CV-A6 and CV-A10, necessitates the exploration of other vaccine platforms. Thus, the antigenic peptide-based vaccines are promising platforms to develop safe and efficacious multivalent vaccines, while the monoclonal antibodies are viable therapeutic and prophylactic agents against HFMD etiological agents. This article reviews the available information related to the antigenic peptides of the etiological agents of HFMD and their neutralizing antibodies that can provide a basis for the design of future therapies against HFMD etiological agents.

Matched MeSH terms: Hand, Foot and Mouth Disease/immunology*
Fulltext More than meets the naked eye: an unusual psoriatic arthritis mimicry and the important role of dermoscopic examination

Anne LJ, Rahim MJC, Ghazali WSW, Ahmed WAW, Isa SAM

BMC Rheumatol, 2021 Apr 12;5(1):10.
PMID: 33840385 DOI: 10.1186/s41927-021-00182-7

BACKGROUND: Psoriatic arthritis (PsA) can manifest in various forms. This includes mimicry of other diseases. We describe an unusual mimicry of PsA.
CASE PRESENTATION: We report a case of a middle-aged lady who presented with severe pain and morning stiffness over the small joints of the left hand for 3 months and painless deformity of the affected joints 1 year before. She was under treatment for pruritic rash over her ankles and knees for the past 1 year as well. Physical examination revealed a fixed flexion deformity, swelling and tenderness of the left ring and little fingers' distal interphalangeal (DIP) joints. Left hand radiograph showed sclerotic joint margin, narrowed joint space and marginal osteophytes of the affected DIP joints. Dermoscopic examination showed red- violaceous, flat-topped papules and plaques with minimal scales on both ankles; hyperpigmented scaly plaques over both knees and vertical fingernail ridges. Serum autoimmune screening and inflammatory markers were unremarkable. Left ankle skin biopsy showed features consistent of psoriasis. PsA was diagnosed. Weekly titrated oral methotrexate and topical steroid were started. The patient showed significant improvement after 1 month of treatment.
CONCLUSION: PsA is a great mimicker. Dermoscopy is an accessible and valuable tool to assess skin lesions in greater detail. Clinicians should be aware of coexisting diseases or misdiagnosis when patients do not respond to treatment.

Matched MeSH terms: Hand
Fulltext Occupational risk factors for carpal tunnel syndrome among nurses in medical

Anuar Ithnin, Kong, Dinnee, Venkataraman, Saraswathy

Int J Public Health Res, 2012;2(2):137-143.
MyJurnal

Carpal tunnel syndrome (CTS) is a hand disorder which indicates the presence of symptoms such as pain, numbness, and muscle weakness among the patient. CTS is an occupational related disorder which can occur in any profession. However, it can be prevented and managed. The aims of the research were to determine the prevalence of acquiring CTS among nurses who worked in the wards and occupational risk factors involving the upper limbs during nursing tasks performance. The specific aims were to determine the relationship between the prevalence of acquiring CTS and individual factors (age, gender, race, educational level, duration of work and medical history), relationship between the prevalence of acquiring CTS and occupational risk factors in nursing tasks. Nurses profession was chosen as they are performing multitask involving upper limbs especially the wrist joints. Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) was used to determine the level of severity in CTS. Occupational risk factors were assessed by using the Rapid Upper Limb Assessment (RULA). This research was a cross sectional mode which was carried out at a government university medical centre from November through December 2010. Eighty nurses were involved in the research. The respondents were required to fill in the socio-demographic information sheet. Those having CTS were required to fill in the BCTQ. Assessments were performed by observing of the job activity through RULA. The results showed that the prevalence for nurses acquiring CTS is 7.5%. The RULA assessment also indicated that the risk factor was in the highest level with a score of 7. No relationship was shown between the prevalence of CTS and race, gender, educational level and medical history. Significant relationship was indicated by the prevalence of CTS and occupational risk factors. In conclusion, a significant prevalence of CTS related to age of more than 30 years old, Malay races compared to Indian, working experience of more than 10 years and respondents with right hand dominant. Occupational risk factors also indicated among the active nurses. Therefore, it is important for us to modify the work environment, work flow, work methodology and ergonomic factors in order to prevent the nurses from acquiring CTS. Furthermore, education about the condition of CTS should be implemented and reinforced especially among the higher risk nurses.

Matched MeSH terms: Hand
Fulltext Resection of thumb metacarpal ewing sarcoma and primary reconstruction with non-vascularized osteoarticular metatarsal autograft

Ariff, M.S., Faisham, W.I., Krishnan, J., Zulmi, W.

International Medical Journal Malaysia, 2015;14(1):103-107.
MyJurnal

Ewing sarcoma is a primary bone malignancy that rarely occurs in the hand. Resection and reconstruction will usually result in reduced or loss of thumb function. We describe a case of successful transplantation of non- vascularized osteoarticular second metatarsal autograft following wide resection of Ewing sarcoma of first metacarpal in an 11-year-old girl. The capsule of the graft’s metatarso-phalangeal joint was repaired to achieve mobility of the joint. This enabled preservation of thumb function by a relatively simple surgical technique. Detailed surgical procedures and excellence function after 2 years following surgery are described.

Matched MeSH terms: Hand
Fulltext Key enablers in a production sharing contract operatorship transfer exercise

Ariffin Samsuri, Zainal Zakaria, Kamal Hafez Manaf, Issham Ismail

Journal of Advanced Review on Scientific Research, 2017;37(1):1-13.
MyJurnal

Production Sharing Contract (PSC) is one of the petroleum agreements mode that
are being utilized in many parts of the world in enabling exploration, development
and production of the petroleum resources at the respective locations. It was first
introduced in Indonesia in 1966, and followed by Malaysia, Vietnam, Thailand, and
Brunei. One of interesting aspects of PSC management is the operatorship
transferhandling when a PSC is nearing its expiry. When the time come, the
current PSC contractor as operator has the option to relinquish it to the host
authority to be handed over to other operator, farm it out to the other PSC
contractor to reduce the risk exposure or continue operating under a new PSC
terms. The most challenging will be to relinquish the operatorship to another
operator whereby several complexities will need to be adequately addressed to
ensure benefit preservation to the host authority, incoming operator and
outgoing operator. Therefore there is a need to adhere to key factors or enablers
to administer the operatorship transfer exercise if it occurs in the near future. The
key enablers would be able to address the operatorship transfer exercise
effectively with the objective to alleviate complications to the host authority,
outgoing operator and incoming operator. With the emphasized in the PETRONAS
Procedure & Guideline for Upstream Activities together with three case studies,
this paper proposed several key enablers to be considered for a PSC successful
operatorship transfer which is human resources, data management, asset
reliability and integrity management, supply chain management and good
relationship between parties. With identified key factors, it is hoped that any PSC
operatorship transfer will be able to be managed smoothly and will ensure
benefits to all parties concerned.

Matched MeSH terms: Hand
Fulltext Hemi-hamate Arthroplasty in Chronic Fracture-dislocation of Proximal Interphalangeal Joint of Fingers: A Report of Two Cases

Arsad SR, Sem SH, Silvanathan JP, Muhammad Nawawi RF

Cureus, 2020 Jan 22;12(1):e6735.
PMID: 32140316 DOI: 10.7759/cureus.6735

Dorsal dislocations of proximal interphalangeal joint with palmar lip fractures base of middle phalanx of fingers are rare, complex, and often a challenging injury to the treating hand surgeons especially in those chronic cases. Hemi-hamate arthroplasty is the preferred surgical option in treating chronic dorsal fracture-dislocations of the proximal interphalangeal joint. We report two cases with a chronic injury that have been treated with hemi-hamate arthroplasty. Range of motion, pinch and grip strengths, QuickDASH scores, complications, and radiological findings were recorded at follow-up. Good functional outcomes were observed in both patients without major complications. Hemi-hamate arthroplasty can be a reliable surgical treatment for chronic proximal interphalangeal joint fracture-dislocations.

Matched MeSH terms: Hand Strength
Hybrid learning control for improving suppression of hand tremor

As'arry A, Md Zain MZ, Mailah M, Hussein M

Proc Inst Mech Eng H, 2013 Nov;227(11):1171-80.
PMID: 23901066 DOI: 10.1177/0954411913494325

Patients with hand tremors may find routine activities such as writing and holding objects affected. In response to this problem, an active control technique has been examined in order to lessen the severity of tremors. In this article, an online method of a hybrid proportional-integral control with active force control strategy for tremor attenuation is presented. An intelligent mechanism using iterative learning control is incorporated into the active force control loop to approximate the estimation mass parameter. Experiments were conducted on a dummy hand model placed horizontally in a tremor test rig. When activated by a shaker in the vertical direction, this resembles a postural tremor condition. In the proportional-integral plus active force control, a linear voice coil actuator is used as the main active tremor suppressive element. A sensitivity analysis is presented to investigate the robustness of the proposed controller in a real-time control environment. The findings of this study demonstrate that the intelligent active force control and iterative learning controller show excellent performance in reducing tremor error compared to classic pure proportional, proportional-integral and hybrid proportional-integral plus active force control controllers.

Matched MeSH terms: Hand/physiopathology
A cross-sectional evaluation on physical fitness of Malaysian firefighters

Atikah C, Nihayah M, Omar B, Leonard J, Noor Ibrahim M, Zurkarnain M, et al.

Sains Malaysiana, 2015;44:1461-1466.

Fire fighting is one of the most strenuous activities in the hazardous fire service industry. Firefighters have to be physically fit in order to provide an effective and safe fire prevention to the afflicted community and as well as to themselves. The aimed of this cross-sectional study was to evaluate the physical fitness among Malaysian firefighters. The hand grip test to evaluate hand and muscular strength was measured using hand dynamometer and one-minute sit ups and one-minute push ups were conducted to measure abdominal muscle endurance. The sit and reach test was carried out to measure lower back and hamstring flexibility. VO2 max was assessed by a 20 meter shuttle run test to measure cardiorespiratory fitness. A total of 385 subjects were participated and the results showed that 77.1% (n=297) and 84.8% (n=325) of them had very poor scores for hand grip strength and VO2 max, respectively. For one-minute sit ups, 40.8% (n=157) of subjects scored excellent. Meanwhile, 32.7% (n=126) subjects scored average for one-minute push ups. For flexibility test, 53.2% (n=205) subjects had poor flexibilty. The results showed there were significantly difference between one-minute sit ups (p<0.001), one-minute push ups (p<0.05), flexibility (p<0.05) and VO2 max (p<0.001) according to age. As a conclusion, this study provides representative data on physical fitness among Malaysian firefighters. These findings suggested the needs to explore the issues behind low physical fitness among Malaysian firefighters and to find ways to improve them.

Matched MeSH terms: Hand Strength
Fulltext Higher-order Brain Areas Associated with Real-time Functional MRI Neurofeedback Training of the Somato-motor Cortex

Auer T, Dewiputri WI, Frahm J, Schweizer R

Neuroscience, 2018 May 15;378:22-33.
PMID: 27133575 DOI: 10.1016/j.neuroscience.2016.04.034

Neurofeedback (NFB) allows subjects to learn self-regulation of neuronal brain activation based on information about the ongoing activation. The implementation of real-time functional magnetic resonance imaging (rt-fMRI) for NFB training now facilitates the investigation into underlying processes. Our study involved 16 control and 16 training right-handed subjects, the latter performing an extensive rt-fMRI NFB training using motor imagery. A previous analysis focused on the targeted primary somato-motor cortex (SMC). The present study extends the analysis to the supplementary motor area (SMA), the next higher brain area within the hierarchy of the motor system. We also examined transfer-related functional connectivity using a whole-volume psycho-physiological interaction (PPI) analysis to reveal brain areas associated with learning. The ROI analysis of the pre- and post-training fMRI data for motor imagery without NFB (transfer) resulted in a significant training-specific increase in the SMA. It could also be shown that the contralateral SMA exhibited a larger increase than the ipsilateral SMA in the training and the transfer runs, and that the right-hand training elicited a larger increase in the transfer runs than the left-hand training. The PPI analysis revealed a training-specific increase in transfer-related functional connectivity between the left SMA and frontal areas as well as the anterior midcingulate cortex (aMCC) for right- and left-hand trainings. Moreover, the transfer success was related with training-specific increase in functional connectivity between the left SMA and the target area SMC. Our study demonstrates that NFB training increases functional connectivity with non-targeted brain areas. These are associated with the training strategy (i.e., SMA) as well as with learning the NFB skill (i.e., aMCC and frontal areas). This detailed description of both the system to be trained and the areas involved in learning can provide valuable information for further optimization of NFB trainings.

Matched MeSH terms: Hand/physiology
Immune responses against enterovirus A71 infection: Implications for vaccine success

Aw-Yong KL, NikNadia NMN, Tan CW, Sam IC, Chan YF

Rev Med Virol, 2019 09;29(5):e2073.
PMID: 31369184 DOI: 10.1002/rmv.2073

Enterovirus A71 (EV-A71) from the Picornaviridae family is an important emerging pathogen causing hand, foot, and mouth disease (HFMD) outbreaks worldwide. EV-A71 also caused fatal neurological complications in young children especially in Asia. On the basis of seroepidemiological studies from many Asian countries, EV-A71 infection is very common. Children of very young age are particularly vulnerable. Large-scale epidemics that occur every 3 to 4 years are associated with accumulation of an immunologically naive younger population. Capsid proteins especially VP1 with the presence of major B- and T-cell epitopes are the most antigenic proteins. The nonstructural proteins mainly contribute to T-cell epitopes that induce cross-reactive immune responses against other enteroviruses. Dominant epitopes and their neutralization magnitudes differ in mice, rabbits, and humans. Neutralizing antibody is sufficient for immune protection, but poorer cellular immunity may lead to severe neurological complications and deaths. Some chemokines/cytokines are consistently found in severely ill patients, for example, IL-6, IL-10, IL-17A, MCP-1, IL-8, MIG, IP-10, IFN-γ, and G-CSF. An increase in white cell counts is a risk factor for severe HFMD. Recent clinical trials on EV-A71 inactivated vaccine showed >90% efficacy and a robust neutralization response that was protective, indicating neutralizing antibody correlates for protection. No protection against other enteroviruses was observed. A comprehensive understanding of the immune responses to EV-A71 infection will benefit the development of diagnostic tools, potential therapeutics, and subunit vaccine candidates. Future development of a multivalent enterovirus vaccine will require knowledge of correlates of protection, understanding of cross-protection and memory T-cell responses among enteroviruses.

Matched MeSH terms: Hand, Foot and Mouth Disease
Fulltext Immunodominant IgM and IgG Epitopes Recognized by Antibodies Induced in Enterovirus A71-Associated Hand, Foot and Mouth Disease Patients

Aw-Yong KL, Sam IC, Koh MT, Chan YF

PLoS One, 2016;11(11):e0165659.
PMID: 27806091 DOI: 10.1371/journal.pone.0165659

Enterovirus A71 (EV-A71) is one of the main causative agents of hand, foot and mouth disease (HFMD). Unlike other enteroviruses that cause HFMD, EV-A71 is more frequently associated with severe neurological complications and fatality. To date, no effective licensed antivirals are available to combat EV-A71 infection. Little is known about the immunogenicity of viral non-structural proteins in humans. Previous studies have mainly focused on characterization of epitopes of EV-A71 structural proteins by using immunized animal antisera. In this study, we have characterized human antibody responses against the structural and non-structural proteins of EV-A71. Each viral protein was cloned and expressed in either bacterial or mammalian systems, and tested with antisera by western blot. Results revealed that all structural proteins (VP1-4), and non-structural proteins 2A, 3C and 3D were targets of EV-A71 IgM, whereas EV-A71 IgG recognized all the structural and non-structural proteins. Sixty three synthetic peptides predicted to be immunogenic in silico were synthesized and used for the characterization of EV-A71 linear B-cell epitopes. In total, we identified 22 IgM and four IgG dominant epitopes. Synthetic peptide PEP27, corresponding to residues 142-156 of VP1, was identified as the EV-A71 IgM-specific immunodominant epitope. PEP23, mapped to VP1 41-55, was recognized as the EV-A71 IgG cross-reactive immunodominant epitope. The structural protein VP1 is the major immunodominant site targeted by anti-EV-A71 IgM and IgG antibodies, but epitopes against non-structural proteins were also detected. These data provide new understanding of the immune response to EV-A71 infection, which benefits the development of diagnostic tools, potential therapeutics and subunit vaccine candidates.

Matched MeSH terms: Hand, Foot and Mouth Disease/immunology*

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