Visual feature tuning properties of short-latency stimulus-driven ocular position drift responses during gaze fixation

Ocular position drifts during gaze fixation are significantly less well-understood than microsaccades. We recently identified a short-latency ocular position drift response, of approximately 1 min arc amplitude, that is triggered within <100 ms by visual onsets. This systematic eye movement response is feature-tuned and seems to be coordinated with a simultaneous resetting of the saccadic system by visual stimuli. However, much remains to be learned about the drift response, especially for designing better-informed neurophysiological experiments unraveling its mechanistic substrates. Here we systematically tested multiple new feature tuning properties of drift responses. Using highly precise eye tracking in three male rhesus macaque monkeys, we found that drift responses still occur for tiny foveal visual stimuli. Moreover, the responses exhibit size tuning, scaling their amplitude (both up and down) as a function of stimulus size, and they also possess a monotonically increasing contrast sensitivity curve. Importantly, short-latency drift responses still occur for small peripheral visual targets, which additionally introduce spatially-directed modulations in drift trajectories towards the appearing peripheral stimuli. Drift responses also remain predominantly upward even for stimuli exclusively located in the lower visual field, and even when starting gaze position is upward. When we checked the timing of drift responses, we found that it was better synchronized to stimulus-induced saccadic inhibition than to stimulus onset. These results, along with a suppression of drift response amplitudes by peri-stimulus saccades, suggest that drift responses reflect the rapid impacts of short-latency and feature-tuned visual neural activity on final oculomotor control circuitry in the brain.Significance statement During gaze fixation, the eye drifts slowly in between microsaccades. While eye position drifts are not entirely random, they remain to be significantly more enigmatic than microsaccades, and they are typically mathematically modeled as random walk processes. Having recently found that these eye movements are systematically modulated with very short latencies by some stimulus onsets, here we characterized the feature-tuning properties of such stimulus-driven drift responses. Our results suggest that drift eye movements reflect the impacts of short-latency sensory signals on the oculomotor system. These results also demonstrate that visual stimuli can impact drift eye movements in a manner similar to how such stimuli impact microsaccades.

Visual feature tuning properties of stimulus-driven saccadic inhibition in macaque monkeys

Saccadic inhibition refers to a short-latency transient cessation of saccade generation after visual sensory transients. This oculomotor phenomenon occurs with a latency that is consistent with a rapid influence of sensory responses, such as stimulus-induced visual bursts, on oculomotor control circuitry. However, the neural mechanisms underlying saccadic inhibition are not well understood. Here, we exploited the fact that macaque monkeys experience robust saccadic inhibition to test the hypothesis that inhibition time and strength exhibit systematic visual feature tuning properties to a multitude of visual feature dimensions commonly used in vision science. We measured saccades in three monkeys actively controlling their gaze on a target, and we presented visual onset events at random times. Across seven experiments, the visual onsets tested size, spatial frequency, contrast, orientation, motion direction, and motion speed dependencies of saccadic inhibition. We also investigated how inhibition might depend on the behavioral relevance of the appearing stimuli. We found that saccadic inhibition starts earlier, and is stronger, for large stimuli of low spatial frequencies and high contrasts. Moreover, saccadic inhibition timing depends on motion direction and orientation, with earlier inhibition systematically occurring for horizontally drifting vertical gratings. On the other hand, saccadic inhibition is stronger for faster motions and when the appearing stimuli are subsequently foveated. Besides documenting a range of feature tuning dimensions of saccadic inhibition to the properties of exogenous visual stimuli, our results establish macaque monkeys as an ideal model system for unraveling the neural mechanisms underlying a ubiquitous oculomotor phenomenon in visual neuroscience.NEW & NOTEWORTHY Visual onsets dramatically reduce saccade generation likelihood with very short latencies. Such latencies suggest that stimulus-induced visual responses, normally jump-starting perceptual and scene analysis processes, can also directly impact the decision of whether to generate saccades or not, causing saccadic inhibition. Consistent with this, we found that changing the appearance of the visual onsets systematically alters the properties of saccadic inhibition. These results constrain neurally inspired models of coordination between saccade generation and exogenous sensory stimulation.

Regulation of Epithelial-Mesenchymal Transition by Cyrtopodion Scabrum: An in vitro Study against Colorectal Cancer Cells

BACKGROUND

Natural treatment of cancer has received a lot of attention recently due to its advantages including low cost, and fewer side effects. In this study, we aimed to investigate the antimetastatic properties of Cyrtopodion scabrum, a common home gecko, through Epithelial-Mesenchymal Transition (EMT) process.

METHODS

Human colon cancer HCT116 cell line was selected and allocated into the following experimental groups: untreated control, vehicle control (DMSO), Retinoic acid (RA), and two treatment groups including aqueous C.scabrum Whole Extract (CWE) and C.scabrum Cell Extract (CCE) groups. The effects of the two different extracts on the viability, migration, and morphology of HCT116 cells were investigated using MTT, colony formation, and wound healing assay as well as microscopic evaluation. We also investigated the gene expression of E-cad, N-cad, and Snail genes using Real-Time PCR analysis.

RESULTS

Our findings revealed that CWE and CCE were toxic to the HCT116 cell line with IC50 values of 590 and 680 µg/mL, respectively. Colony formation and migration ability of cancer cells were also inhibited by the two extracts, and the morphology of the cells were determined as epithelial phenotype. Moreover, the expression of N-cad and Snail were remarkably decreased in CWE and CCE, and RA groups, while E-cad didn't change significantly as compared to the control.

CONCLUSION

The results suggest that C. scabrum extract (CsE) may induce its anti-cancer activity through the inhibition of cancer cell growth and the EMT process. CCE, as a valuable natural source, could be also suggested, to be used as an alternative/complementary medicine for the treatment of cancer, in clinical trials.

Barriers to Applying Integrative Oncology from the Perspective of the Care Providers in Iran: A Mixed-Methods Study

OBJECTIVE

The present study aims to explain and determine the use of integrative oncology from the perspective of the care providers in Iran.

DATA SOURCES

This mixed-methods study is a convergent type of study with quantitative and qualitative phases that have been performed simultaneously. The quantitative phase was a descriptive study that was conducted through convenience sampling. With the use of a psychometrically evaluated questionnaire with 10 items, 202 nurses and physicians were included in the study to assess their views on the integration of traditional and complementary medicine (TCM) within supportive cancer care. The qualitative part of the study was conducted through semistructured interviews with 11 care providers. The interviews were analyzed through conventional content analysis and the method proposed by Graneheim and Lundman with the use of MaxQDA software.

CONCLUSION

After the quantitative and the qualitative data were combined, we identified four main categories as the important dimensions of using TCM: patients' main expectations of TCM services, reasons for using these services, existing challenges and barriers, and recommendations and strategies to improve the interaction between physicians and patients to facilitate the use of integrative oncology .

IMPLICATION FOR NURSING PRACTICE

Although cancer patients use TCM due to a wide range of expectations, there are many barriers to integrative oncology in Iran. Therefore, it is necessary to pay attention to the benefits of conventional medical and TCM treatments, conceptualize integrative oncology, and try to meet the existing challenges.

Determining the psychometric properties of safety attitudes questionnaire in NICUs

INTRODUCTION

This study aimed to translate and assess the psychometric properties of the Persian version of the "Safety Attitude Questionnaire" in the NICUs.

METHODS

In this psychometric study, the "Safety Attitude Questionnaire" was translated into Persian. Then this version was used for psychometric evaluation. For this purpose, the qualitative face, content validity and construct validity were performed by confirmatory factor analysis. Internal consistency and stability reliability were calculated. Data were analyzed using SPSS and AMOS software.

RESULTS

Face validity was also performed with a slight change in four items. The factor structure of the tool was determined by confirmatory factor analysis. Fit indices were appropriate. Internal consistency reliability in the whole questionnaire was 0.65 and the stability reliability was calculated to be 0.64.

DISCUSSION AND CONCLUSION

"Safety Attitude Questionnaire" has appropriate psychometric properties and can be used in NICUs.

Validation of post-traumatic growth inventory in mothers with the experience of having the NICU-Hospitalized newborns "validation of post-traumatic growth inventory"

AIMS

Investigating post-traumatic growth (PTG) in mothers with the experience of having a preterm newborn hospitalized in the NICU requires a valid tool. This study aims to determine the validity and reliability of the Farsi version of the post-traumatic growth inventory (PTGI) in mothers with the experience of having their newborns hospitalized in the NICU.

DESIGN

This study was methodological research.

METHODS

In this study, 250 mothers who had newborns with a history of NICU hospitalization during the last 3 to 12 months and had visited paediatric clinics of the selected hospitals in Tehran with the aim of having their children's condition examined were selected through convenience sampling. The data were collected using a demographic information questionnaire and PTGI. The face validity, the construct validity (confirmatory factor analysis), and the internal consistency reliability of the inventory were measured using SPSS V22 and LISREL V8.8.

RESULTS

According to appropriate values for factor analysis fit indices (FI = 0.94, RMSEA = 0.07, IFI = 0.94, NFI = 0.93, RFI = 0.91, NNFI = 0.93, SRMR = 0.07), 21 items and 5 factors were confirmed for this inventory. Furthermore, Cronbach's alpha coefficient of this inventory was measured as α = 0.94.

CONCLUSION

According to favourable psychometric properties, the Farsi version of PTGI is a suitable tool for studying PTG in mothers with the experience of having preterm newborns in the NICU. Using PTGI can help nurses in planning family-centered care interventions to reduce the impact of the mental trauma caused by the preterm newborn's hospitalization in parents.

PATIENT OR PUBLIC CONTRIBUTION

Mothers who had newborns with a history of NICU hospitalization during the last 3-12 months.

Potential Anti-Inflammatory and Growth Inhibitory Effect of Cyrtopodion scabrum Extract on Colon Cancer; An in vivo Study

BACKGROUND

The use of complementary and/or alternative medicine to increase the efficacy and decrease the side effects of current cancer treatment is highly required. In this in-vivo study, we aimed to investigate the anti-tumor activity and probable side effects of a natural treatment, Cyrtopodion scabrum extract (CsE), in a model of tumor bearing mice.

METHODS

We established 28 female CT26-tumor bearing balb/c-mice model. We divided them randomly into four groups (n=7): Negative control received distilled water (DW) and the three treatment groups were administered with 5-FU and two different doses (300 and 600 mg/kg) of the gecko aqueous extract, respectively. The changes in the tumor volumes and weights during and after treatment, along with the blood cell counts; spleen and thymus indices were assessed in the treatment groups. We have also measured the serum TNF-α, VEGF, AST, ALT and GSH, as well as the physical activities of the experimental mice.

RESULTS

We found that the means of tumor weights and volumes in both CsE and 5-FU treated groups were significantly lower than the untreated group (p<0.05). Serum TNF-α and VEGF levels in both CsE treated groups were remarkably lower than 5-FU and untreated groups (p<0.05). The 5-FU treatment caused a remarkably decrease in serum GSH, RBC count, WBC count, thymus index, and spleen index , while CsE treatment maintained these quantities, with no significant changes, compared to the control group. AST and ALT were not significantly changed in none of the treated groups compared to control.

CONCLUSION

Altogether, data suggest C. scabrum, as an effective and safe anti-cancer natural source, which could be used as an alternative/complementary medicine for the treatment of patients who suffer from colon cancer.

Evaluation of the Effect of Reduction Mammoplasty on Body Posture in Patients with Macromastia

BACKGROUND

Breast hypertrophy is a significant health problem with both physiological and psychological impacts on the patients' lives. Patients with macromastia adopt a corrective posture due to the effect of the breast on the center of gravity and possibly in a subconscious effort to conceal their breasts.

OBJECTIVE

This study aimed to evaluate whether the posture of patients with macromastia changed after the reduction of mammoplasty.

MATERIAL AND METHODS

In this prospective study, patients with breast cup sizes C, D, and DD were scheduled for reduction mammoplasty in 3 Shiraz University Hospitals. Age, weight, height, and preoperative cup sizes of the breasts were recorded for every patient, and all patients underwent posture analysis with forceplate before and after reduction mammoplasty. Finally, the preoperative and postoperative data were compared.

RESULTS

Mean age at the time of reduction mammaplasty was 43.57±9.1; the mean pre-operation, such as weight, height, and mean the body mass index (BMI) was 76.57±10 kg, 158.28±6 cm and 30.57±4.1, respectively. The average Anterior-posterior (AP) direction velocity before and after the surgery was 0.85±0.12 cm/s and 0.79±0.098, respectively. These values were 0.83±0.09 and 0.81±0.10 for the mediolateral direction. The Detrended Fluctuation Analysis (DFA) value for the AP direction was 1.63±0.3 and 1.60±0.2 for pre-and post-surgery, respectively, which was not statistically different. The DFA value for maximum likelihood (ML) direction was 1.65±0.2 and 1.48±0.2 in pre-op and post-op, respectively, which was statistically significantly different.

CONCLUSION

Reducing the weight of enlarged breasts can correct disturbed sagittal balance and postural sway.

Explanation of factors forming missed nursing care during the COVID-19 pandemic: A qualitative study

Background

Providing nursing care to patients with COVID-19 has put additional pressure on nurses, making it challenging to meet several care requirements. This situation has caused parts of nursing care to be missed, potentially reducing the quality of nursing care and threatening patient safety. Therefore, the present study aimed at explaining the factors forming missed nursing care during the COVID-19 pandemic from the perspective of nurses.

Methods

This qualitative study was conducted using a conventional content analysis approach in Iran, 2020-2021. Data were collected from in-depth, semi-structured interviews with 14 nurses based on purposive sampling. Data analysis was performed simultaneously with data collection. Graneheim and Lundman's approach was used for data analysis, and MAXQDA software was used for data management. After transcribing the recorded interviews, to achieve the accuracy and validity of the study, the criteria proposed by Lincoln and Guba were considered and used.

Results

A total of 14 nurses with a mean age and standard deviation of 31.85 ± 4.95 and working in the COVID-19 wards participated in the study. The acquired data were categorized into four main categories: care-related factors, disease-related factors, patient-related factors, and organization-related factors. The category "care-related factors" comprised uncertainty in care, PPE-related limitations, attrition from care, and futile care. The category "disease-related factors" consisted of the extension of symptoms, unpredictable peaks of the disease, and restriction on the presence of patients' companions. The category "patient-related factors" included comorbidities, elderly patients, and deterioration of infected patients. Ultimately, the category "organization-related factors" consisted of restrictions on equipment supply, lack of human resources, weaknesses in teamwork, and an unsupportive work environment.

Conclusion

The results of this study showed that several reasons including factors related to care, patient, disease, and organization cause missed nursing care. By modifying the related affecting factors and considering the effective mechanisms to minimize missed nursing care, it is possible to provide better services.

Repurposing FDA-approved drugs cetilistat, abiraterone, diiodohydroxyquinoline, bexarotene, and remdesivir as potential inhibitors against RNA dependent RNA polymerase of SARS-CoV-2: A comparative in silico perspective

Vaccines are undoubtedly the most effective means of combating viral diseases like COVID-19. However, there are risks associated with vaccination, such as incomplete viral deactivation or potential adverse effects in humans. However, designing and developing a panel of new drug molecules is always encouraged. In an emergency, drug repurposing research is one of the most potent and rapid options. RdRp (RNA-dependent RNA polymerase) has been discovered to play a pivotal role in viral replication. In this study, FDA-approved drugs bexarotene, diiodohydroxyquinoline, abiraterone, cetilistat, and remdesivir were repurposed against the RdRp by molecular modeling, docking, and dynamic simulation. Furthermore, to validate the potency of these drugs, we compared them to the antiviral remdesivir, which inhibits RdRp. Our finding indicated that the selected drugs have a high potential to be developed as RdRp inhibitors and, with further validation studies, could serve as potential drugs for the treatment of COVID-19.

Caregivers' Knowledge of and Attitude towards Palliative Care in Iran

BACKGROUND

Addressing the palliative care needs requires clinicians to have sufficient knowledge of and positive attitudes toward palliative care. The study aimed to determine nurses' and physicians' knowledge of and attitudes towards palliative care in Iran.

METHODS

This descriptive cross-sectional study was conducted in 2021 on 493 physicians and nurses, selected through convenience sampling. Three online questionnaires addressing caregivers' demographic and professional's questionnaire, Health Care Providers' Attitude toward PC Questionnaire, and Health Care Providers' Knowledge of PC Questionnaire were used. The data was analyzed in SPSS using correlational and descriptive statistics and regression analysis.

RESULTS

The mean score of attitude towards palliative care was 142.03 ± 11.35 and the mean score of palliative care knowledge, 19.47 ± 2.62. Considering the regression coefficients between these two mean scores (P-value = 0.001, b = 1.304), it can be inferred that knowledge is a good predictor of attitude. In addition, the mean scores of knowledge and attitude have a significant relationship with age, female gender, holding a master's or PhD degree, the need for formal education in the field of palliative care and the need to take a palliative care course.

CONCLUSIONS

The present study showed that Iranian nurses and physicians have a moderate level of knowledge and attitude towards palliative care. It is necessary to take measures in order to improve knowledge and attitude by holding retraining courses, theoretical and clinical training sessions and relevant seminars in short term, and also by integrating related topics into nursing and medical curriculums in long term.

Rewiring Cortico-Muscular Control in the Healthy and Poststroke Human Brain with Proprioceptive β-Band Neurofeedback

In severely affected stroke survivors, cortico-muscular control is disturbed and volitional upper limb movements often absent. Mental rehearsal of the impaired movement in conjunction with sensory feedback provision are suggested as promising rehabilitation exercises. Knowledge about the underlying neural processes, however, remains vague. In male and female chronic stroke patients with hand paralysis, a brain-computer interface controlled a robotic orthosis and turned sensorimotor β-band desynchronization during motor imagery (MI) of finger extension into contingent hand opening. Healthy control subjects performed the same task and received the same proprioceptive feedback with a robotic orthosis or visual feedback only. Only when proprioceptive feedback was provided, cortico-muscular coherence (CMC) increased with a predominant information flow from the sensorimotor cortex to the finger extensors. This effect (1) was specific to the β frequency band, (2) transferred to a motor task (MT), (3) was proportional to subsequent corticospinal excitability (CSE) and correlated with behavioral changes in the (4) healthy and (5) poststroke condition; notably, MI-related enhancement of β-band CMC in the ipsilesional premotor cortex correlated with motor improvements after the intervention. In the healthy and injured human nervous system, synchronized activation of motor-related cortical and spinal neural pools facilitates, in accordance with the communication-through-coherence hypothesis, cortico-spinal communication and may, thereby, be therapeutically relevant for functional restoration after stroke, when voluntary movements are no longer possible.SIGNIFICANCE STATEMENT This study provides insights into the neural processes that transfer effects of brain-computer interface neurofeedback to subsequent motor behavior. Specifically, volitional control of cortical oscillations and proprioceptive feedback enhances both cortical activity and behaviorally relevant connectivity to the periphery in a topographically circumscribed and frequency-specific way. This enhanced cortico-muscular control can be induced in the healthy and poststroke brain. Thereby, activating the motor cortex with mental rehearsal of the impaired movement and closing the loop by robot-assisted feedback synchronizes ipsilesional premotor cortex and spinal neural pools in the β frequency band. This facilitates, in accordance with the communication-through-coherence hypothesis, cortico-spinal communication and may, thereby, be therapeutically relevant for functional restoration after stroke, when voluntary movements are no longer possible.

Causes of Missed Nursing Care During COVID-19 Pandemic: A Qualitative Study in Iran

Background

The unpredictable and variable nature of COVID-19 and the lack of healthcare resources has led to inadequate care for patients. This study aimed to explain the causes of missed nursing care during the COVID-19 pandemic from the perspective of Iranian nurses.

Method

This qualitative study was conducted using semi-structured interviews with 14 nurses caring for patients with COVID-19 in three hospitals in Iran. Sampling was performed by the purposive method. Data were analyzed using the conventional content analysis method. The interviews were first recorded and transcribed, and then the data were analyzed using the Elo and Kyngas method. Data management was done with MAXQDA software version 10. To achieve trustworthiness, the criteria presented by Lincoln and Guba were used.

Findings

A total of 14 nurses participated in the study. The mean age of participants was 31.85 ± 4.95 years, and the mean number of years of work experience was 7.71 ± 4.44. Eleven participants were women. Among all participants, nine had a bachelor's degree and five had a master's degree. Four nurses had fixed shifts, while ten nurses had rotating shifts. The causes of missed nursing care were categorized into 4 groups. The category “unfulfilled care” comprised the reasons for forgetting care, neglecting care, arbitrary elimination of care, and compulsory elimination of care. The category of “care at improper time” consisted of interference of the care in patients' daily activities and interference with other healthcare providers' activities. The “incomplete cares” category comprised failure to complete the care period in hospital, interruption in care, and discontinuance of care after patient discharge. The last category, “incorrect care,” consisted of providing care regardless of the nursing process, providing care by unqualified professionals, and providing trial-and-error care.

Conclusion

This study illustrates an understanding of the causes of missed nursing care during the COVID-19 pandemic from the perspective of nurses. The increasing demand for care caused by the pandemic and problems in the work environment has led to the failure of nurses to provide complete, correct care and sometimes miss parts of care to patients. Therefore, nursing policymakers and managers should develop and implement appropriate care protocols and instructions to minimize missed nursing care.

Efficient conjugation of anti-HBsAg antibody to modified core-shell magnetic nanoparticles (Fe3O4@SiO2/NH2)

Introduction: Further development of magnetic-based detection techniques could be of significant use in increasing the sensitivity of detection and quantification of hepatitis B virus (HBV) infection. The present work addresses the fabrication and characterization of a new bio-nano composite based on the immobilization of goat anti-HBsAg antibody on modified core-shell magnetic nanoparticles (NPs) by (3-aminopropyl) triethoxysilane (APTES), named Fe₃O₄@SiO₂/NH₂, and magnetic NPs modified by chitosan (Fe₃O₄@CS).

Methods: At the first step, Fe₃O₄ was modified with the silica and APTES (Fe₃O₄@SiO₂/NH₂) and chitosan (Fe₃O₄@CS) separately. The goat anti-HBsAg antibody was activated by two different protocols: Sodium periodate and EDC-NHS. Then the resulted composites were conjugated with activated goat anti-HBsAg IgG. An external magnet collected Bio-super magnetic NPs (BSMNPs) and the remained solution was analyzed by the Bradford method to check the amount of attached antibody to the surface of BSMNPs.

Results: The findings indicated that activation of antibodies by sodium periodate method 15-17 µg antibody immobilized on 1 mg of super magnetic nanoparticles (SMNPs). However, in the EDC-NHS method, 8-10 µg of antibody was conjugated with 1 mg of SMNPs. The resulting bio-magnetic NPs were applied for interaction with the HBsAg target using enzyme-linked immunosorbent assay (ELISA). About 1 µg antigen attached to 1 mg SMNPs, which demonstrated that the fabricated materials are applicable in the detection scope of HBsAg.

Conclusion: In the present study, we developed new antibody-conjugated magnetic NPs for the detection of HBsAg using an efficient conjugation strategy. The results demonstrated that the binding capacity of Fe₃O₄@SiO₂/NH₂ was comparable with commercially available products. Our designed method for conjugating anti-HBsAg antibody to a magnetic nanoparticle opens the way to produce a high capacity of magnetic NPs.

The effect of mandala colouring on anxiety in hospitalized COVID-19 patients: A randomized controlled clinical trial

COVID-19 significantly affects patients' mental health, triggering a wide range of psychological disorders, including anxiety. The aim of this study was to investigate the effect of mandala colouring on the anxiety of hospitalized COVID-19 patients. In this randomized controlled clinical trial, 70 hospitalized patients with COVID-19 were randomly divided between the intervention and control groups. Standard care was provided for both groups. The intervention group spent 30 min/day for six consecutive days performing mandala colouring. Patient anxiety was measured prior and subsequent to the intervention in both groups using the Spielberger State-Trait Anxiety Inventory. Data were analysed using SPSS software version 25. The mean anxiety score was not significantly different between the two groups before the intervention (P = 0.08). Subsequent to the intervention, the mean anxiety score in the intervention and control groups was 44.05 ± 4.67 and 67.85 ± 6.25, respectively, indicating a statistically significant (P = 0.0001) decrease in the anxiety measured among the intervention group as compared with that of the control group. The results of this study show that 30 min of mandala colouring daily is an effective strategy for reducing anxiety in hospitalized COVID-19 patients. Mandala colouring can complement routine treatment and provides a non-pharmaceutical option for decreasing patient anxiety.

Inhibitory activity of FDA-approved drugs cetilistat, abiraterone, diiodohydroxyquinoline, bexarotene, remdesivir, and hydroxychloroquine on COVID-19 main protease and human ACE2 receptor: A comparative in silico approach

By September 1, 2021, SARS-CoV-2, a respiratory virus that prompted Coronavirus Disease in 2019, had infected approximately 218,567,442 patients and claimed 4,534,151 lives. There are currently no specific treatments available for this lethal virus, although several drugs, including remdesivir and hydroxychloroquine, have been tested. The purpose of this study is to assess the activity of FDA-approved drugs cetilistat, abiraterone, diiodohydroxyquinoline, bexarotene, remdesivir, and hydroxychloroquine as potential SARS-CoV-2 main protease inhibitors. Additionally, this study aims to provide insight into the development of potential inhibitors that may inhibit ACE2, thereby preventing SARS-CoV-2 entry into the host cell and infection. To this end, remdesivir and hydroxychloroquine were used as comparator drugs. The calculations revealed that cetilistat, abiraterone, diiodohydroxyquinoline, and bexarotene inhibit main protease and ACE2 receptors more effectively than the well-known drug hydroxychloroquine when used against COVID-19. Meanwhile, bexarotene and cetilistat bind more tightly to the SARS-CoV-2 main protease and the ACE2 receptor, respectively, than remdesivir, a potential treatment for COVID-19 that is the first FDA-approved drug against this virus. As a result, the molecular dynamic simulations of these two drugs in the presence of proteins were investigated. The MD simulation results demonstrated that these drugs interact to stabilize the systems, allowing them to be used as effective inhibitors of these proteins. Meanwhile, bexarotene, abiraterone, cetilistat, and diiodohydroxyquinoline's systemic effects should be further investigated in suitable ex vivo human organ culture or organoids, animal models, or clinical trials.

Current Advances in the Use of Nanophytomedicine Therapies for Human Cardiovascular Diseases

Considering the high prevalence of cardiovascular diseases (CVDs), the primary cause of death during the last several decades, it is necessary to develop proper strategies for the prevention and treatment of CVDs. Given the excessive side effects of current therapies, alternative therapeutic approaches like medicinal plants and natural products are preferred. Lower toxicity, chemical diversity, cost-effectiveness, and proven therapeutic potentials make natural products superior compared to other products. Nanoformulation methods improve the solubility, bioavailability, circulation time, surface area-to-volume ratio, systemic adverse side effects, and drug delivery efficiency of these medications. This study intended to review the functionality of the most recent nanoformulated medicinal plants and/or natural products against various cardiovascular conditions such as hypertension, atherosclerosis, thrombosis, and myocardial infarction. Literature review revealed that curcumin, quercetin, and resveratrol were the most applied natural products, respectively. Combination therapy, conjugation, or fabrication of nanoparticles and nanocarriers improved the applications and therapeutic efficacy of herbal- or natural-based nanoformulations. In the context of CVDs prevention and/or treatment, available data suggest that natural-based nanoformulations are considerably efficient, alone or in blend with other herbal/synthetic medicines. However, clinical trials are mandatory to elucidate the safety, cardioprotective effect, and mechanism of actions of nanophytomedicines.

Instantaneous movement-unrelated midbrain activity modifies ongoing eye movements

At any moment in time, new information is sampled from the environment and interacts with ongoing brain state. Often, such interaction takes place within individual circuits that are capable of both mediating the internally ongoing plan as well as representing exogenous sensory events. Here, we investigated how sensory-driven neural activity can be integrated, very often in the same neuron types, into ongoing saccade motor commands. Despite the ballistic nature of saccades, visually induced action potentials in the rhesus macaque superior colliculus (SC), a structure known to drive eye movements, not only occurred intra-saccadically, but they were also associated with highly predictable modifications of ongoing eye movements. Such predictable modifications reflected a simultaneity of movement-related discharge at one SC site and visually induced activity at another. Our results suggest instantaneous readout of the SC during movement generation, irrespective of activity source, and they explain a significant component of kinematic variability of motor outputs.

The Construction and Characterization of 1F5 Chimeric Anti-CD20 Monoclonal Antibodies: An Efficient Splicing by Overlap Extension-polymerase Chain Reaction Technique

Despite the unparalleled success of anti-CD20-targeted immunotherapy, the currently available mAbs are not sufficiently efficacious in the treatment of lymphoma. 1F5 is one of a panel of anti-CD20 mAbs that was used in the B-cell lymphoma serotherapy. Despite the efficacy of murine 1F5 mAbs in lymphoma patients, the 1F5 chimeric antibodies with human effector functionality are yet to be approved and widely used in the treatment of lymphoma. In this study, the conversion of 1F5 mAb from mouse IgG2a to human-mouse chimeric IgG1 was achieved and the chimeric antibody was partially characterized. We constructed the 1F5 chimeric mouse-human anti-CD20 antibody genes using an efficient Splicing by overlap extension-polymerase chain reaction (SOE-PCR) technique and cloned the chimeric heavy and light genes in pBudCE4.1mammalian expression vector, followed by purification of the expressed chimeric 1F5 mAbs using affinity chromatography. Our investigation also included the biological properties of purified chimeric antibodies. The generated 1F5 chimeric mAbs mediate complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC) against Raji and Daudi Burkitt's lymphoma cell lines, which were comparable with rituximab and exhibit superior reduction in cell viability in vitro, compared to rituximab. The current study indicated that the generated chimeric 1F5 mAbs has potential CDC and ADCC activity which was comparable with rituximab whereas it exhibits a superior reduction in cell viability, compared to rituximab. Our work contributes to future studies involving in vivo biological functions and the application of the 1F5 chimeric antibody.

Selenium nanoparticles: Synthesis, in-vitro cytotoxicity, antioxidant activity and interaction studies with ct-DNA and HSA, HHb and Cyt c serum proteins

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Spherical SeNPs with average size 134 nm were synthesized employing Vitamin C.

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The synthesized SeNPs represented great antioxidant and anticancer activity.

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The interaction of SeNPs with ct-DNA, HSA, HHb and Cyt c was investigated.

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Nano-selenium can bind to ct-DNA through partial intercalation binding mode.

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HSA, HHb and Cyt c could keep their biological activity even in the presence of Nano-selenium.

The aim of this study was the synthesis of selenium nanoparticles (SeNPs) employing vitamin C as a biocompatible and low toxic reducing agent. The synthesized selenium nanoparticles were characterized by using UV–vis, FT-IR, SEM-EDX, TEM, DLS, and zeta potential measurements. The results of the DPPH free radical scavenging assay demonstrate that this synthesized nano-selenium has strong potentials to scavenge the free radicals and cytotoxicity against MCF-7 and Raji Burkitt's lymphoma cancer cell lines. The interaction of calf thymus DNA (ct-DNA) with SeNPs indicated that the anticancer activity might be associated with the DNA-binding properties of nano-selenium. Finally, it was found that the synthesized nano-selenium can bind to the most important blood proteins such as human serum albumin (HSA), human hemoglobin (HHb), and Cytochrome c (Cyt c). The results showed that the secondary structure of these proteins remains unchanged, suggesting that the synthesized nano-selenium could be employed as a carrier in the drug delivery system without any cytotoxicity effect.

Psychometric Properties of the Farsi Version of Posttraumatic Growth Inventory for Children-Revised in Iranian Children with Cancer

Objective:

Coping with childhood cancer, as a stressful incident, can lead to a growth in various aspects of the child's life. Therefore, this study aims to validate Posttraumatic Growth Inventory for Children-Revised (PTGI-C-R) in children with cancer.

Methods:

This methodological research was carried out in referral children hospitals in Tehran. PTGI-C-R was translated and back-translated. Content and face validity were assessed. Confirmatory factor analysis (CFA) was performed on 200 children with inclusion criteria, using LISREL V8.5. Due to the rejection of the model, an exploratory factor analysis (EFA) was done, using SPSS V21. The correlation of posttraumatic growth (PTG) with the variables, i.e., age and gender, was investigated.

Results:

Some writing changes were made in phrases in the sections concerning face and content validity. CFA rejected the five-factor model due to the undesirable fit indices. Therefore, an EFA was used and the three-factor model was not approved, either despite the statistical appropriateness or due to the lack of similarity between the items loaded on factors. The results also indicated a significant relationship between PTG and age (r = 0.13, P = 0.05). There is no significant relationship between PTG and gender (z = −1.35, P = 0.83).

Conclusions:

PTGI-C-R does not have desirable psychometric properties in Iranian children with cancer and may not be able to reflect all the aspects of PTG experienced by them. Therefore, it cannot be used as an appropriate scale, and it is necessary to develop and validate a specific tool through a qualitative study.

The Antimicrobial Peptide, Nisin, Synergistically Enhances the Cytotoxic and Apoptotic Effects of Rituximab Treatment on Human Burkitt's Lymphoma Cell Lines

Background

Non-Hodgkin's lymphomas comprise the most common hematological cancers worldwide and consist of a heterogenous group of malignancies affecting the lymphoid system. Treatment of non-Hodgkin's lymphoma has been significantly enhanced with the addition of Rituximab to the standard chemotherapy regimen. However, even with the advancement of treatment patients continue to relapse and develop resistance to Rituximab, rendering subsequent treatments unsuccessful. The use of novel drugs with unique antitumor mechanisms has gained considerable attention. In this study, we explored the in vitro anti-cancer effects of the combined therapy of Rituximab and Nisin on human Burkitt's lymphoma cells.

Methods

The human Burkitt's lymphoma cells lines, Raji and Daudi, were treated with Nisin, Rituximab, or a combination of the two agents at various concentrations. Cytotoxicity following treatment was determined using cell viability assay. The degree of apoptosis was verified via flow cytometric analysis using FITC annexin V/PI staining.

Results

Our findings show that the combined treatment of Rituximab and Nisin results in a more significant reduction in the survival of Raji and Daudi Burkitt's lymphoma cells, compared to Nisin or Rituximab treatment alone. Additionally, our results indicate that Nisin can induce a significant degree of apoptosis in the Burkitt's lymphoma cells compared to the negative controls. However, the addition of Nisin to the Rituximab treatment synergistically enhances the apoptotic antitumor effect.

Conclusion

This study demonstrates the synergistic antitumor effect of Nisin treatment in vitro to enhance tumor cell apoptosis and the potential value of Nisin as an adjunct therapy in the treatment of lymphoma.

Production of monoclonal antibody against recombinant bovine sex-determining region Y (SRY) and their preferential binding to Y chromosome-bearing sperm

Separation of X and Y chromosome-bearing sperm is an appropriate method for the selection of desired sex of offspring to increase the profit in livestock industries. The purpose of this study was the production of a monoclonal antibody against recombinant bovine sex-determining region Y protein for separation Y sperm. The hybridoma cells from splenocytes of immunized female's balb/C mice and Sp2/0 cells were made. The binding affinity of our monoclonal antibody (mAbSRY2) was compared with mouse monoclonal SRY-15. The Western blot method indicated that mAbSRY2 successfully detected the rbSRY protein. The specificity and sensitivity of mAbSRY2 is comparable to SRY-15 commercially ones. The SRY gene in 100% of bull semen contains the Y chromosome that had the strongest binding affinity to mAbSRY2 was synthesized. In other words, the binding affinity of semen contains the X sperms near the negative control. In general, this immunological method can help to separate X from Y sperms. However, the mAbSRY2 is bind to Y-bearing sexed sperm, but in the future; the sexed sperms need to apply in farms.

Molecular detection of carbapenem-resistant genes in clinical isolates of Klebsiella pneumoniae

INTRODUCTION

The emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a considerable threat to public health worldwide. The aim of this study was to determine the prevalence of CRKP isolated from clinical specimens by phenotypic and genotypic methods.

METHODS

In total, 110 consecutive non-repetitive isolates of K. pneumoniae were analyzed. Minimal inhibitory concentrations (MICs) of imipenem were determined. The mechanism of resistance was evaluated by imipenem-EDTA combined disk test and modified Hodge test. PCR method was used for the detection of blaVIM, blaIMP, blaNDM-1, blaOXA-48 and KPC genes.

RESULTS

Totally, 8 (7.3 %) isolates were resistant to imipenem, showing MIC ≥4 µg/mL. Based on imipenem-EDTA combined disk test, all imipenem-resistant isolates were metallo-beta-lactamase (MBL) positive. PCR confirmed that 6 (75%) isolates were blaNDM-1 positive. Other resistance genes (blaVIM, blaIMP, blaOXA-48 and KPC) were not detected.

CONCLUSIONS

Based on this study, the prevalence of CRKP strains was not at a high level, however, continuous monitoring of antibiotic resistance should be performed to control dissemination of CRKP infections.

Glutathione-dependent enzymes in the follicular fluid of the first-retrieved oocyte and their impact on oocyte and embryos in polycystic ovary syndrome: A cross-sectional study

Background

Oxidative stress and GSH-dependent antioxidant system plays a key role in the pathogenesis of polycystic ovary syndrome (PCOS).

Objective

We compared glutathione peroxidase (GPx) and glutathione reductase activities and reduced glutathione (GSH) levels in serum and follicular fluid (FF) of the first-retrieved follicle and their impact on quality of oocyte and embryo in PCOS women undergoing IVF.

Materials and Methods

This cross sectional study was conducted on 80 pairs of blood samples and FF of the first-retrieved follicle from PCOS women, at the Infertility center of Ghadir Mother and Child Hospital. The mean activity of GPx and GR, also GSH levels in the serum and FF were compared to the quality of the first follicle and resultant embryo.

Results

Retrieved oocytes included 53 (66.25%) MII, 17 (21.25%) MI, and 10 (12.5%) germinal vesicles; after IVF 42 (52.50%) embryos with grade I and 11 (13.75%) with grade II were produced. The mean values for all three antioxidants were higher in the FF compared to serum (p < 0.001). Also all of the mean measured levels were significantly higher in the FF of the MII oocytes compared to that of oocytes with lower grades (p = 0.012, 0.006 and 0.012, respectively). The mean GPX activity and GSH levels were significantly higher in the serum (p = 0.016 and 0.012, respectively) and FF (p = 0.001 for both) of the high-quality grade I embryos.

Conclusion

GSH-dependent antioxidant system functions more efficiently in the FF of oocytes and embryos with higher quality.

Covid-19 and nursing home residents: The potential role of geriatric nurses in a special crisis

The article's abstract is no available.

Visual feature tuning of superior colliculus neural reafferent responses after fixational microsaccades

The primate superior colliculus (SC) is causally involved in microsaccade generation. Moreover, visually responsive SC neurons across this structure's topographic map, even at peripheral eccentricities much larger than the tiny microsaccade amplitudes, exhibit significant modulations of evoked response sensitivity when stimuli appear perimicrosaccadically. However, during natural viewing, visual stimuli are normally stably present in the environment and are only shifted on the retina by eye movements. Here we investigated this scenario for the case of microsaccades, asking whether and how SC neurons respond to microsaccade-induced image jitter. We recorded neural activity from two male rhesus macaque monkeys. Within the response field (RF) of a neuron, there was a stable stimulus consisting of a grating of one of three possible spatial frequencies. The grating was stable on the display, but microsaccades periodically jittered the retinotopic RF location over it. We observed clear short-latency visual reafferent responses after microsaccades. These responses were weaker, but earlier (relative to new fixation onset after microsaccade end), than responses to sudden stimulus onsets without microsaccades. The reafferent responses clearly depended on microsaccade amplitude as well as microsaccade direction relative to grating orientation. Our results indicate that one way for microsaccades to influence vision is through modulating how the spatio-temporal landscape of SC visual neural activity represents stable stimuli in the environment. Such representation depends on the specific pattern of temporal luminance modulations expected from the relative relationship between eye movement vector (size and direction) on one hand and spatial visual pattern layout on the other.NEW & NOTEWORTHY Despite being diminutive, microsaccades still jitter retinal images. We investigated how such jitter affects superior colliculus (SC) activity. We found that SC neurons exhibit short-latency visual reafferent bursts after microsaccades. These bursts reflect not only the spatial luminance profiles of visual patterns but also how such profiles are shifted by eye movement size and direction. These results indicate that the SC continuously represents visual patterns, even as they are jittered by the smallest possible saccades.

Antibiotic resistance profiles of Salmonella serotypes isolated from animals in Iran: a meta-analysis

BACKGROUND

Salmonella infection (salmonellosis) is a zoonotic bacterial disease. Widespread use of antibiotics in livestock and poultry production for different purposes such as treatment and growth promotion has led to the emergence of antibiotic-resistant Salmonella, causing treatment of Salmonella infections more difficult with each passing year.

AIMS

To determine the antibiotic resistance prevalence of Salmonella serotypes isolated from animals in different provinces of Iran.

METHODS

To find eligible articles, we searched the international and national electronic databases using appropriate keywords in English and Persian.

RESULTS

After applying predefined criteria, 54 articles reporting antibiotic resistance profiles of Salmonella serotypes were included. Salmonella isolates were mostly resistant against nalidixic acid (67%), tetracycline (66.9%), and streptomycin (49.6%), followed by trimethoprim/sulfamethoxazole (41.6%) and kanamycin (23.6%). The highest sensitivity was observed against imipenem, meropenem, and cefepime with 1.7%, 1.4%, and 1.9% of all isolates being resistant, respectively.

CONCLUSION

Results revealed that the prevalence of resistant isolates to nalidixic acid, tetracycline and streptomycin is high and their use must be restricted. In addition, resistance to other antibiotics such as chloramphenicol, ampicillin, cephalothin, cefixime, and enrofloxacin is at an alarming level that calls for attention in the future infection control and antibiotic stewardship programs.

Distinct Beta-band Oscillatory Circuits Underlie Corticospinal Gain Modulation

Rhythmic synchronization of neurons is known to affect neuronal interactions. In the motor system, oscillatory power fluctuations modulate corticospinal excitability. However, previous research addressing phase-specific gain modulation in the motor system has resulted in contradictory findings. It remains unclear how many time windows of increased responsiveness each oscillatory cycle provides. Moreover, we still lack conclusive evidence as to whether the motor cortex entails an intrinsic response modulation along the rhythm cycle, as shown for spinal neurons. We investigated this question with single-pulse transcranial magnetic stimulation over the primary motor cortex at rest. Application of near-motor threshold stimuli revealed a frequency- and phase-specific gain modulation at both cortical and spinal level, independent of the spontaneous oscillatory power fluctuations at each level. We detected bilateral sensorimotor circuits in the lower beta-band (14–17 Hz) and unilateral corticospinal circuits in the upper beta-band (20–24 Hz). These findings provide novel evidence that intrinsic activity in the human motor cortex modulates input gain along the beta oscillatory cycle within distinct circuits. In accordance with periodic alternations of synchronous hyper- and depolarization, increased neuronal responsiveness occurred once per oscillatory beta cycle. This information may lead to new brain state-dependent and circuit-specific interventions for targeted neuromodulation.

Caring power of mothers who have a child with cancer and its predictors

Background: Attention to the family care provider needs and their caring power is essential. Since mothers are considered as the child’s main care provider, this study aimed to determine the caring power and its predictors among mothers of children with cancer. Materials and Methods: In this descriptive-correlational study, 196 mothers who had a child with cancer were selected through purposive sampling. The data were collected using two questionnaires, namely demographics questionnaire and the care power of the care providers of cancer patient questionnaire. The data were analyzed using SPSS 19 and running descriptive statistics and regression analysis. Results: The highest average score belonged to dimensions of “effective role play” (44.62 ± 5.28) and “trust” (14 ± 1.67), and the lowest ones respectively belonged to dimensions of “fatigue and resignation” (22.38 ± 6.33), “awareness” (8.46 ± 2.70), and “uncertainty” (12.38 ± 3.50). In addition, variables of educational level (p <0.001), adequacy of family income (p <0.001), and duration of illness (p0.29) were found as predictors of caring power. Conclusion: The results of this study showed that the caring power of mothers with a child with cancer is favorable. High trust and effective role-play reduced fatigue and resignation of mothers, and low awareness about the provision of care caused uncertainty affecting negatively the care power. In addition, the adequacy of family income, the high level of mother's education, and the reduction in the duration of the disease had a direct impact on care power.

Nicotine-Induced Oxidative Stress in Human Primary Endometrial Cells

Nicotine is a major component of tobacco plants and is responsible for the development of reproductive problems in smokers. Nicotine has been recognized to result in oxidative stress by inducing the generation of reactive oxygen species (ROS) in some parts of female reproductive system, but the effect of nicotine on endometrium that plays an important role in reproductive biology stays unexplored. The aim of this work was to clarify the direct effects of nicotine administration on the antioxidant defense system and lipid peroxidation in human endometrial cells. Human endometrial stromal primary cells were treated with nicotine (0, 10−11, 10−8, and 10−6 M) for 24 hours. On nicotine administration, the endometrial cells were associated with a decrease in antioxidant defense markers such as Glutathione (GSH) level, glutathione peroxidase (GPx), glutathione reductase (GR), and catalase (CAT) enzymes activity and higher levels of malondialdehyde (MDA) in a dose-dependent manner when compared to the control. We concluded that nicotine as a pro-oxidant affects the oxidative state of the endometrial cells.

A systematic review and meta-analysis on the epidemiology of antibiotic resistance of Vibrio cholerae in Iran

BACKGROUND

Cholera, an acute diarrheal disease caused by Vibrio cholerae (V. cholerae), is an endemic disease and a major public health problem in Iran. Antibiotic therapy can decrease duration of the disease, transmission of infection and contamination of the environment. Considering different pattern of V. cholerae antibiotic resistance around the world, the aim of the current systematic review and meta-analysis was to evaluate the prevalence of antibiotic resistance of V. cholerae in Iran.

METHODS

A systematic review of the literature was performed using related keywords in the electronic national and international databases including SID, Irandoc, Iran Medex and Magiran as well as PubMed, Scopus, Google Scholar and ISI web of knowledge. Up to July 31, 2018, 27 eligible papers were included in our meta-analysis based on the defined inclusion criteria.

RESULTS

V. cholerae O1 was the most prevalent strain isolated in Iran and exhibited a high resistance rate against numerous antibiotics including chloramphenicol (33.6%), oxytetracycline (40.2%), trimethoprim/sulphamethoxazole (86%), tetracycline (34.5%), furazolidone (69.8%), streptomycin (93.8%), polymyxin (80.7%), ampicillin (32.1%), nalidixic acid (88.9%), kanamycin (29%) and amoxicillin (30.5%).

CONCLUSIONS

According to the meta-analysis results, antibiotic therapy with ciprofloxacin, doxycycline, erythromycin, gentamicin, azithromycin, cefixime and cefepime could be effective for the treatment of severe cases of cholera in Iran.

An Evidence-Based Study on Medicinal Plants for Hemorrhoids in Medieval Persia

Hemorrhoids is one of the most common gastrointestinal diseases. There are several therapeutic options associated with some complications. Therefore, researchers look for traditional medicines as a potential resource for introduction of new natural drugs. The current study reports an evidence-based review of herbal remedies for hemorrhoids in traditional Persian medicine. A comprehensive survey about hemorrhoids on the most important manuscripts of traditional Persian medicine was done. Then, scientific data banks were searched for possible related properties of each herb in the conventional medicine. We reported some historical aspects of traditional Persian medicine view on classification, examination, and predisposing factors of hemorrhoids. In addition, we have reported 105 medicinal plants belonging to 51 families. More than half of the reported herbs exhibited anti-inflammatory and analgesic effects. Although lack of human studies regarding the mentioned herbs is noted, positive results from experimental findings can be considered for new drug discovery supported by traditional and medieval experiences.

Oral Contraceptive Use May Modulate Global Genomic DNA Methylation and Promoter Methylation of APC1 and ESR1

Background:

There are challenging reports in the public health sphere regarding associations between oral contraceptive (OC) use and cancer risk.

Methods:

To evaluate possible effects of OCs on cancer susceptibility, we quantified of global 5-methyl cytosine (5-mC) levels and assessed methylation patterns of CpG islands of two key tumor suppressor genes, APC1 and ESR1, in serum of users by enzyme-linked immunosorbent assay and methylation specific PCR methods, respectively.

Results:

Our results indicated that OCs significantly decrease the level of global DNA methylation in users relative to control non-users. However, our data revealed no significant differences between CpG island methylation patterns for ESR1 and APC1 in healthy control and OC-treated women. However, we did find a trend for hypermethylation of both tumor suppressor genes in OC users.

Conclusion:

Our data suggest that the level of 5-mC but not individual CpG island patterns is significantly influenced by OCs in our cross-section of adult users.

Construction and characterization of monoclonal antibodies against the extracellular domain of B-lymphocyte antigen CD20 using DNA immunization method

To date, several new anti-CD20 monoclonal antibodies (mAbs) have been developed for potential efficacies compared with familiar mAb rituximab. Despite the recent advances in development of anti-CD20 mAbs for the treatment of B cell malignancies, the efforts should be continued to develop novel antibodies with improved properties. However, the development of mAbs against CD20 as a multi-transmembrane protein is challenging due to the difficulty of providing a lipid environment that can maintain native epitopes. To overcome this limitation, we describe a simple and efficient DNA immunization strategy for the construction of a novel anti-CD20 mAb with improved anti-tumour properties. Using a DNA immunization strategy that includes intradermal (i.d.) immunization with naked plasmid DNA encoding the CD20 gene, we generated the hybridoma cell line D4, which secretes functional mAbs against an extracellular epitope of CD20. Immunocytochemistry analysis and a cell-based enzyme-linked immunosorbent assay using a Burkitt's lymphoma cell line showed that D4 mAbs are capable of binding to native extracellular epitopes of CD20. Moreover, the binding specificity of D4 mAbs was determined by western blot analysis. Cell proliferation was examined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was detected by the annexin V/propidium iodide staining and dye exclusion assay. The results showed that D4 anti-CD20 mAbs produced by DNA immunization exhibit potent growth inhibitory activity and have superior direct B-cell cytotoxicity compared to rituximab. We propose that antibody-induced apoptosis is one of the mechanisms of cell growth inhibition. Taken together, the data reported here open the path to DNA-based immunization for generating pharmacologically active monoclonal antibodies against CD20. In addition, the data support future in vivo animal testing and subsequent procedures to produce a potential therapeutic mAb.