Triterpenes from Euphorbia spinidens with immunomodulatory activity.

Dried aceton-chloroform extract of aerial parts of Euphorbia spinidens Bornm. ex Prokh. endemic to Iran, yielded two new triterpenoids, lup-20(29)-ene-33, 28 diol commonly known as betulin and (3ß,23E)-Cycloarta-23-ene-3,25-diol. The structures of the isolated compounds were elucidated by 13C- and 1H-NMR as well as 2D-NMR, IR and by the aid of mass fragmentation pattern. In phagocyte chemiluminescence assay, different concentrations of compounds were incubated with the human whole blood in triplicate and the chemiluminescence activity of phagocytic cells were measured by using serum opsonized zymosan and luminol. For lymphocyte proliferation assay, peripheral human blood lymphocytes were incubated with different concentrations of the test compound in supplemented Roswell Park Memorial Institute (RPMI) 1640 medium along with 5.0 µg/ml phytohemagglutinin (PHA) at 37°C in CO2 environment for 72 h and proliferation level was determined by Beta-scintillation counter. In phagocyte chemiluminescence assay, betulin showed moderate inhibitory effect on the oxidative burst in the neutrophils, while addition of betulin triterpene was able to stimulate the proliferation of the phytohemagglutinin (PHA) treated human peripheral blood lymphocytes (hPBLs).

The prevalence of internet addiction among students of Rafsanjan University of Medical Sciences

Internet addiction is defined as mismanagement of internet use that causes mental, social and occupational problems. Thus, the assessment of prevalence of this disorder can lead to preventive measures and appropriate treatment to prevent its spread. Methods: In this cross-sectional study, prevalence of internet addiction disorder was assessed in Rafsanjan University of Medical Sciences, Rafsanjan, Iran in 2012. Stratified random sample was used to select 224 students. Demographic data were recorded and Internet Addiction test Test (IAT) questionnaire was administrated. Results: Out off 224 students participating in the study, 86 (38.4%) were males and 138 (61.6%) were female with a mean age of 21.05± 0.1 years. Most of the students (42.4%) were using the internet "under one hour" and the lowest (4%) "More than six hours". Mean test score of IAT was 24.81 ± 1.08 (mild addiction). In terms of internet addiction, 95 (42.4%) cases were normal users, 115 (51.3%) had mild addiction, 12 (5.4%) showed moderate addiction and 2 (0.9%) were cases of severe addiction which are lower compared to previous studies. Conclusion: The rate of internet addiction among students of Rafsanjan University of Medical Sciences in Iran is lower than the previous reports. It is still necessary to curb the spread of this problem due to its complications.

New tigliane-type diterpenoids from Euphorbia aellenii Rech. f. with immunomodulatory activity.

The cytotoxic chloroform fraction of Euphorbia aellenii Rech. F. (Euphorbiaceae) afforded two new phorbol diterpenoids: 4-deoxy-4α-phorbol-12-(2,3-dimethyl) butyrate-13-isobutyrate and 17-hydroxy-4-deoxy-4α-phorbol-12-(2,3-dimethyl) butyrate-13-isobutyrate. Their structures were elucidated by NMR and other spectroscopic methods. The immunomodulating potentials of the isolated compounds were tested using standard proliferation and chemiluminescence assays. Compound 2 showed moderate inhibitory activity against both T-cell proliferation and reactive oxygen species (ROS) production in whole blood with IC50 of 14.0 ± 0.57 and 44.1 ± 3.8 µg/ml, respectively, while compound 1 was relatively inactive with IC50 >50 µg/mL for T-cell proliferation, and >100 µg/mL for ROS.

A modified Zeeman model for producing HRV signals and its application to ECG signal generation.

Developing a mathematical model for the artificial generation of electrocardiogram (ECG) signals is a subject that has been widely investigated. One of the challenges is to generate ECG signals with a wide range of waveforms, power spectra and variations in heart rate variability (HRV)--all of which are important indexes of human heart functions. In this paper we present a comprehensive model for generating such artificial ECG signals. We incorporate into our model the effects of respiratory sinus arrhythmia, Mayer waves and the important very low-frequency component in the power spectrum of HRV. We use a new modified Zeeman model for generating the time series for HRV, and a single cycle of ECG is produced by using a simple neural network. The importance of the work is the model's ability to produce artificial ECG signals that resemble experimental recordings under various physiological conditions. As such the model provides a useful tool to simulate and analyse the main characteristics of ECG, such as its power spectrum and HRV under different conditions. Potential applications of this model include using the generated ECG as a flexible signal source to assess the effectiveness of a diagnostic ECG signal-processing device.

Validity and reliability of the Persian translation of the SF-36 version 2 questionnaire.

To assess the validity and reliability of a Persian translation of the SF-36 questionnaire (version 2) as a tool for use in the general population and outpatients, we carried out a cross-sectional study of the staff of Shiraz Medical School during November 2001. Response rate was 83.6%. Internal consistency for 8 scales using Cronbach's alpha was 0.87 (minimum recommended 0.85). Construct validity was acceptable as correlation between scales and some sociodemographic characteristics was significant. The correlation coefficient between 8 scales and related principal components was also acceptable. This translation is an appropriate tool for assessing health perceptions of the population.

Validity and reliability of the Persian translation of the SF-36 version 2 questionnaire

To assess the validity and reliability of a Persian translation of the SF-36 questionnaire [version 2] as a tool for use in the general population and outpatients, we carried out a cross-sectional study of the staff of Shiraz Medical School during November 2001. Response rate was 83.6%. Internal consistency for 8 scales using Cronbach's alpha was 0.87 [minimum recommended 0.85]. Construct validity was acceptable as correlation between scales and some sociodemographic characteristics was significant. The correlation coefficient between 8 scales and related principal components was also acceptable. This translation is an appropriate tool for assessing health perceptions of the population

Wigner-Ville distribution and Gabor transform in Doppler ultrasound signal processing.

Time-frequency distributions have been used extensively for nonstationary signal analysis, they describe how the frequency content of a signal is changing in time. The Wigner-Ville distribution (WVD) is the best known. The draw back of WVD is cross-term artifacts. An alternative to the WVD is Gabor transform (GT), a signal decomposition method, which displays the time-frequency energy of a signal on a joint t-f plane without generating considerable cross-terms. In this paper the WVD and GT of ultrasound echo signals are computed analytically.

Using the discrete Gabor expansion for the Doppler ultrasound signal processing.

In this paper we have synthesized the Doppler signal with a known time varying mean frequency, then used the orthogonal-like Discrete Gabor Transform (DGT) and the spectrogram for analyzing the signal. Mean square error has been computed for each method respectively and at last we have analyzed the real clinical signal too.