Facilitating the analysis of the multifocal electroretinogram using the free software environment R

2018 ◽  
Vol 28 (1) ◽  
pp. 87-93
Author(s):  
Richard Bergholz ◽  
Mirjam Rossel ◽  
Ralf M. Dutescu ◽  
Klaas P. Vöge ◽  
Daniel J. Salchow

Purpose: The large amount of data rendered by the multifocal electroretinogram (mfERG) can be analyzed and visualized in various ways. The evaluation and comparison of more than one examination is time-consuming and prone to create errors. Using the free software environment R we developed a solution to average the data of multiple examinations and to allow a comparison of different patient groups. Methods: Data of single mfERG recordings as exported in .csv format from a RETIport 21 system (version 7/03, Roland Consult) or manually compiled .csv files are the basis for the calculations. The R software extracts response densities and implicit times of N1 and P1 for the sum response, each ring eccentricity, and each single hexagon. Averages can be calculated for as many subjects as needed. The mentioned parameters can then be compared to another group of patients or healthy subjects. Application of the software is illustrated by comparing 11 patients with chloroquine maculopathy to a control group of 7 healthy subjects. Results: The software scripts display response density and implicit time 3D plots of each examination as well as of the group averages. Differences of the group averages are presented as 3D and grayscale 2D plots. Both groups are compared using the t-test with Bonferroni correction. The group comparison is furthermore illustrated by the average waveforms and by boxplots of each eccentricity. Conclusions: This software solution on the basis of the programming language R facilitates the clinical and scientific use of the mfERG and aids in interpretation and analysis.

Mathematics ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 665 ◽  
Author(s):  
Hao Ming ◽  
JinRong Wang ◽  
Michal Fečkan

In this paper, we apply Caputo-type fractional order calculus to simulate China’s gross domestic product (GDP) growth based on R software, which is a free software environment for statistical computing and graphics. Moreover, we compare the results for the fractional model with the integer order model. In addition, we show the importance of variables according to the BIC criterion. The study shows that Caputo fractional order calculus can produce a better model and perform more accurately in predicting the GDP values from 2012–2016.


2021 ◽  
Author(s):  
Antonietta Moramarco ◽  
Luca Lucchino ◽  
Fabiana Mallone ◽  
Michela Marcelli ◽  
Ludovico Alisi ◽  
...  

Abstract The aim of the study was to examine neuroretinal function by using the mfERG test in patients with neurofibromatosis type 1 (NF1) without optic pathway gliomas (OPGs). This study was conducted on 35 patients (35 eyes) with NF1 and 30 healthy subjects (30 eyes) for the control group. Each subject underwent a complete ophthalmological examination including multifocal electroretinography (mfERG). 1.5-Tesla magnetic resonance imaging (MRI) scan of the brain was performed in NF1 patients to assess the presence of OPGs. All participants were recruited having a best corrected visual acuity (BCVA) of no less than 20/20 in each eye. The amplitude and implicit time of the P1 wave (first-order Kernel component) were evaluated on mfERG. Data analysis was carried out in the two central degrees and in the four quadrants from two to 25 degrees of visual field. Statistically significant results were obtained for the P1 wave amplitudes in the 4 quadrants in NF1 patients compared to healthy subjects, while the reduction was not significant in the 2 central degrees. A statistically significant difference was observed among the P1 wave amplitudes as recorded in the 4 quadrants within the NF1 group, with lower amplitudes in the nasal quadrants. No differences in the implicit times were recorded in the 4 quadrants and in the 2 central degrees as compared between NF1 patients and controls. The present study demonstrates impaired neuroretinal function in NF1 patients. Altered intracellular signal transduction due to abnormal neurofibromin-mediated cyclic adenosine monophosphate (cAMP) generation, could be involved. Our results suggest a possible use of mfERG as subclinical retinal damage indicator with a potential utility in clinical practice for the follow-up of NF1 patients.


2021 ◽  
Author(s):  
Zahra Maleki ◽  
Soroor Behbahani ◽  
Hamid Ahmadieh

Abstract Purpose: Non-proliferative diabetic retinopathy (NPDR) is the earliest stage of diabetic eye disease. Microscopic changes occur in the blood vessels of the eye in NPDR. The changes typically do not produce symptoms and are not visible to the naked eye. This paper aims to investigate a method for distinguishing NPDR based on Electroretinogram (ERG).Method: The ERG responses were recorded in 20 eyes from 14 patients with NPDR and 20 eyes from 20 healthy subjects as the control group. The responses of three standard stimuli were collected for both groups. Time-domain parameters, including amplitudes and implicit time, and a nonlinear criterion, were used to differentiate the groups. Results: This study showed that implicit time and amplitude of b-wave in dark-adapted 10.0 ERG and amplitude and implicit time of light-adapted flicker 30 Hz could distinguish between controls and NPDR groups. Theta values obtained for dark-adapted 10.0 ERG (p=0.0019), light-adapted 3.0 ERG (p=0.0021), and light-adapted flicker 30 Hz (p=0.0023) had significant differences between the groups. Conclusion: The proposed features have made it possible to distinguish between healthy and NPDR eyes. Choosing an appropriate method can effectively evaluate inner retinal dysfunction, especially in diabetic retinopathy.


Author(s):  
Niken Setyaningrum ◽  
Andri Setyorini ◽  
Fachruddin Tri Fitrianta

ABSTRACTBackground: Hypertension is one of the most common diseases, because this disease is suffered byboth men and women, as well as adults and young people. Treatment of hypertension does not onlyrely on medications from the doctor or regulate diet alone, but it is also important to make our bodyalways relaxed. Laughter can help to control blood pressure by reducing endocrine stress andcreating a relaxed condition to deal with relaxation.Objective: The general objective of the study was to determine the effect of laughter therapy ondecreasing elderly blood pressure in UPT Panti Wredha Budhi Dharma Yogyakarta.Methods: The design used in this study is a pre-experimental design study with one group pre-posttestresearch design where there is no control group (comparison). The population in this study wereelderly aged over> 60 years at 55 UPT Panti Wredha Budhi Dharma Yogyakarta. The method oftaking in this study uses total sampling. The sample in this study were 55 elderly. Data analysis wasused to determine the difference in blood pressure before and after laughing therapy with a ratio datascale that was using Pairs T-TestResult: There is an effect of laughing therapy on blood pressure in the elderly at UPT Panti WredhaBudhi Dharma Yogyakarta marked with a significant value of 0.000 (P <0.05)


2018 ◽  
Vol 7 (09) ◽  
pp. 91-96
Author(s):  
Irmayanti. A.Oka

The research aimed at investigating the effect of giving counterpressure technique to decrease the intensity of pain in the first stage of labor in the delivery room of RSUD Sawerigading Palopo. This study was conducted in a preexperimental manner with static group comparison design, in subject static group comparison design divided into two groups, where the treatment group was followed by observation and observation result compared with the observation result in the control group which only received standard treatment. Data were analyzed using T test. Where t value hit 6.971> t table 2.05, so it can be concluded that the results obtained mean that there is influence of counterpressure technique is big enough to decrease the intensity of labor pain. Keyword: Counterpressure, Labor Pain, Kala I


2018 ◽  
Vol 15 (1) ◽  
pp. 74-78
Author(s):  
Mohammadali Nazarinia ◽  
Asghar Zare ◽  
Mohammad javad Fallahi ◽  
Mesbah Shams

Background:Systemic sclerosis is a disorder of connective tissue with unknown cause, affecting the skin and internal organs, characterized by fibrotic changes.Objective:To determine the correlation between serum homocysteine level and interstitial lung involvement in systemic sclerosis. </P><P> Materials and Methods: In this case – control study, 59 patients who fulfilled the ACR/EULAR classification criteria for systemic sclerosis and were referred to Hafez Hospital of Shiraz, Iran, were included as the case group. Fifty nine healthy subjects were involved as the control group. Patients were divided into two groups based on interstitial lung involvement and two subtypes, diffuse and limited type. Serum homocysteine, vitamin B12, and folate levels compared between the controls, and cases groups.Results:Of 59 case and control group, 53 (%89.8) were female and the mean age did not differ in both groups (P=0.929). Thirty five (%59.3) patients had interstitial lung involvement and 38(%64.4) had diffuse cutaneous systemic sclerosis. The mean serum homocysteine level was 13.9±6.3 µmol/L in the case and 13.7±9.2 µmol/L in the control group (P=0.86). The mean serum homocysteine level did not differ between the patients with and without interstitial lung involvement (P=0.52). The patients with lung involvement was older than those without lung involvement (P=0.004). Lung disease was more common in diffuse type (P=0.014).Conclusion:In our study, serum homocysteine level did not differ between the patients and healthy subjects. Also, there was no correlation between serum homocysteine level and lung involvement, but lung involvement was more common in older patients and also diffuse subtype.


Author(s):  
Jasem Saki ◽  
Karim Mowla ◽  
Reza Arjmand ◽  
Forough Kazemi ◽  
Somayeh Fallahizadeh

Introduction: Parasitic myositis is caused by some parasites such as T. gondii and T. canis. So, the aim of the study was to evaluate the prevalence T. gondii and T. canis in patients with myositis and healthy individuals. Methods: A total of 108 samples were randomly selected as the control (54 healthy individuals) and test (54 myositis patients) groups. IgG and IgM antibodies against T. gondii and IgG antibodies against T. canis were measured by the ELISA. The detection of chronic and acute toxoplasmosis was performed by the ELISA IgG avidity. The presence of T. gondii in blood was evaluated by the nested-PCR. Results: Of 108, 33 (30.6%) cases were detected positive for IgG against T. gondii that 19 (35.2%) and 14 (25.9%) were observed in myositis patients and healthy individuals, respectively (P=0.296). Of 19 positive cases, 12 (63.2%) and 7 (36.8%) cases were detected as chronic and acute toxoplasmosis, respectively, while, all positive cases in the control group had chronic toxoplasmosis (P=0.013). One (1.9%) sample was detected positive for anti- Toxoplasma gondii IgM and two (3.7%) samples were found positive for IgG against T. canis by the ELISA that these positive cases were observed only in myositis patients (P=1.000 P=0.495, respectively). B1 T. gondii gene was amplified in 12 (63.2%) and 1 (7.1%) in myositis patients and healthy subjects (P=0.001). Conclusions: Our findings showed that there was a relatively high prevalence of acute toxoplasmosis in myositis patients in comparison with the control subjects in southwest of Iran.


2006 ◽  
Vol 124 (5) ◽  
pp. 280-284 ◽  
Author(s):  
Fátima Palha de Oliveira ◽  
Roberto Coury Pedrosa

CONTEXT AND OBJECTIVE: The change in slope of the VE/VCO2 curve with time during exercise (VE/VCO2 slope) has been recommended as a parameter for analyzing the ventilatory response during exercise among patients with heart failure of different etiologies. The aim of this work was to evaluate the ventilatory response among patients with chronic Chagas cardiopathy. METHODS: Forty-eight patients, divided into four groups according to the Los Andes clinical/hemodynamic classification, were studied. They were also classified according to peak oxygen uptake (peak VO2) for a second analysis. The results from the patients were compared with results from a control group consisting of 21 healthy male volunteers (no Chagas disease). Exercise was performed on a cycle ergometer with loads increasing at the rate of 12.5 watts/min, and exercise duration was symptom-limited. Gas concentration and flow rate data were fed into a computer, which produced a real-time report on ventilatory and gas exchange parameters (breath-by-breath). The ventilatory parameters of VE/VCO2 slope and VE/VCO2 ratio computed at different times of the test were adopted. RESULTS: Although there were no significant differences in VE/VCO2 ratio and VE/VCO2 slope when patients were grouped using the Los Andes clinical/hemodynamic classification, these parameters varied significantly when peak VO2 was used to define patient groups. CONCLUSION: Our results indicate that progressive deterioration in ventilatory response among chronic Chagas cardiopathy patients during exercise is more evident when the functional capacity (peak VO2) is reduced, than when changes are related to the Los Andes classification.


2021 ◽  
Vol 10 (8) ◽  
pp. 1716
Author(s):  
Idoia Genua ◽  
Núria Puig ◽  
Inka Miñambres ◽  
Sonia Benítez ◽  
Pedro Gil ◽  
...  

The effect of bariatric surgery on lipid profile and the qualitative characteristics of lipoproteins was analyzed in morbidly obese subjects. Thirteen obese patients underwent bariatric surgery. Plasma samples were obtained before surgery and at 6 and 12 months after the intervention. Thirteen healthy subjects comprised the control group. Lipid profile, hsCRP, and the composition and functional characteristics of VLDL, LDL, and HDL were assessed. At baseline, plasma from subjects with obesity had more triglycerides, VLDLc, and hsCRP, and less HDLc than the control group. These levels progressively normalized after surgery, although triglyceride and hsCRP levels remained higher than those in the controls. The main differences in lipoprotein composition between the obese subjects and the controls were increased apoE in VLDL, and decreased cholesterol and apoJ and increased apoC-III content in HDL. The pro-/anti-atherogenic properties of LDL and HDL were altered in the subjects with obesity at baseline compared with the controls, presenting smaller LDL particles that are more susceptible to modification and smaller HDL particles with decreased antioxidant capacity. Bariatric surgery normalized the composition of lipoproteins and improved the qualitative characteristics of LDL and HDL. In summary, patients with obesity present multiple alterations in the qualitative properties of lipoproteins compared with healthy subjects. Bariatric surgery reverted most of these alterations.


2021 ◽  
Vol 22 (9) ◽  
pp. 4953
Author(s):  
Natalie M. Zahr ◽  
Kilian M. Pohl ◽  
Allison J. Kwong ◽  
Edith V. Sullivan ◽  
Adolf Pfefferbaum

Classical inflammation in response to bacterial, parasitic, or viral infections such as HIV includes local recruitment of neutrophils and macrophages and the production of proinflammatory cytokines and chemokines. Proposed biomarkers of organ integrity in Alcohol Use Disorders (AUD) include elevations in peripheral plasma levels of proinflammatory proteins. In testing this proposal, previous work included a group of human immunodeficiency virus (HIV)-infected individuals as positive controls and identified elevations in the soluble proteins TNFα and IP10; these cytokines were only elevated in AUD individuals seropositive for hepatitis C infection (HCV). The current observational, cross-sectional study evaluated whether higher levels of these proinflammatory cytokines would be associated with compromised brain integrity. Soluble protein levels were quantified in 86 healthy controls, 132 individuals with AUD, 54 individuals seropositive for HIV, and 49 individuals with AUD and HIV. Among the patient groups, HCV was present in 24 of the individuals with AUD, 13 individuals with HIV, and 20 of the individuals in the comorbid AUD and HIV group. Soluble protein levels were correlated to regional brain volumes as quantified with structural magnetic resonance imaging (MRI). In addition to higher levels of TNFα and IP10 in the 2 HIV groups and the HCV-seropositive AUD group, this study identified lower levels of IL1β in the 3 patient groups relative to the control group. Only TNFα, however, showed a relationship with brain integrity: in HCV or HIV infection, higher peripheral levels of TNFα correlated with smaller subcortical white matter volume. These preliminary results highlight the privileged status of TNFα on brain integrity in the context of infection.


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