Sustain release of dexamethasone from polyvinyl alcohol microparticle produced via coaxial microfluidic system.

OBJECTIVE: Polyvinyl alcohol (PVA) as a synthetic biopolymer has unique physicochemical properties to achieve an efficient drug carrier. In this study phenol-substituted polyvinyl alcohol (PVAPh) microparticle was made through a microfluidic system and peroxidase-mediated reaction in the presence of hydrogen peroxide and in following dexamethasone (Dex) release characteristics from this vehicle were elaborated for sustained drug delivery applications. RESULTS: PVAPh was synthesized by esterification and amidation reactions respectively. Then, the synthesized PVAPh solution containing peroxidase and Dex flowed within the inner channel of the coaxial microfluidic device while liquid paraffin saturated with H2O2 flowed from the outer channel. The monodisperse microparticles were produced in a spherical shape with an average diameter of 160 µm. The Dex was successfully encapsulated in PVAPh MP and its sustained release profile was maintained for up to 7 days. It was found that exposure of Dex-loaded PVAPh MPs to subcultured mouse embryonic fibroblast 10T1/2 cells had no deleterious effects on cell viability, morphology and growth rate. Moreover, the sustained release of Dex and the high mechanical durability of PVAPh MPs suggest an excellent prospect for the synthesized PVAPh and the developed method as a biocompatible carrier required for drug delivery and regenerative medicine.

Efficiency of tungsten-polymer composite shields on fetal dose reduction in chest CT scans.

Given their desirable shielding properties, 5 polymer composite shields reinforced with tungsten were selected and their effects as gamma shields on fetal dose reduction were investigated. According to the results, the selected shields reduce the fetus brain, the fetus lungs, the fetus kidneys, and the total fetus dose almost 34.17%-41.19%, 20.47%-25.08%, 9.27%-12.13%, and 15.39%-18.69%, respectively, at tube voltage of 80 kVp. At the higher tube potentials, the values of dose reduction were smaller. Moreover, it was observed that polymers named PHEMA-WO3 and RS-U-30 had an excellent shielding ability among the other studied composites.

Intrarectal Lidocaine-Diltiazem-Meperidine Gel for Transrectal Ultrasound Guided Prostate Biopsy.

BACKGROUND: TRUS-guided needle biopsy of the prostate gland is the current standard method used for diagnosis of prostate cancer. Pain control during this procedure is through the use of i.v. sedation or local anaesthetic (LA), depending on clinician preference. OBJECTIVES: The aim of this study was to evaluate the effectiveness of intrarectal lidocaine, lidocaine-diltiazem and lidocaine-meperidine-diltiazem gel for anesthetizing transrectal ultrasound guided prostate biopsy. PATIENTS AND METHODS: In a randomized double-blind clinical trial, 100 consecutive patients were divided into three groups. The patients received one of the gels before transrectal ultrasound guided prostate needle biopsy: group A, intrarectal and perianal lidocaine, gel 1 g; group B, intrarectal lidocaine gel, 1 g, + perianal diltiazem, 1 g; group C, intrarectal lidocaine gel, 1 g, + meperidine, 25 mg, and perianal diltiazem, 1 g. Visual analog pain scale was used to estimate pain during probe insertion and biopsy. Heart rate and blood pressure during probe insertion and biopsy were recorded too. RESULTS: The mean of visual analog pain scale was 4.5 in group A, 3.5 in group B, and 2.0 in group C during probe insertion (P value = 0.01). The mean of visual analog pain scale was 5.1 in group A, 3.5 group B, and 2.5 in group C during biopsy (P value = 0.001). The groups were comparable for patients' age, weight, serum prostate-specific antigen (PSA), and prostate size (P > 0.05). No side effects of meperidine and lidocaine including drowsiness, dizziness, tinnitus and light-headedness or requiring assistance for activity were noted. CONCLUSIONS: Lidocaine-meperidine-diltiazem gel provides significantly better pain control than lidocaine-diltiazem gel and lidocaine gel alone during transrectal ultrasound guided prostate biopsy and probe insertion. This mixture gel is safe, easy to administer and well accepted by patients.

Senior medical students' attitudes toward psychiatry as a career choice before and after an undergraduate psychiatry internship in Iran.

OBJECTIVES: The study aimed to assess 1) the attitudes of medical students in the sixth and seventh years (known as interns in Iran) toward psychiatry as a career choice, and 2) the degree of attractiveness of psychiatry as a career choice, with regard to various defined aspects, before and after an undergraduate psychiatry internship (similar to the medical school psychiatry rotation in the United States, but mandatory in Iran) in three major medical schools in Tehran, the capital of Iran. METHOD: Sixth- and seventh-year medical students (locally called interns, N=347) at Tehran, Shahid Beheshti, and Iran Universities of Medical Sciences were consecutively invited to complete anonymous self-report questionnaires designed to assess their perceptions of careers in psychiatry before and after internship in psychiatry wards. Also, students evaluated psychiatry in terms of the factors that reflected the degree of attractiveness of this specialty. RESULTS: Positive responses toward choosing psychiatry as a career were seen in 18.8% before and 20.0% after psychiatry rotation. No significant differences were observed in the positive responses before and after psychiatry internship. The students' opinions changed to a more attractive degree in terms of only 3 out of the 13 defined aspects. There was also no significant difference in the total score on attractiveness of psychiatry before and after the psychiatry internship. CONCLUSIONS: The study indicated that undergraduate psychiatry internship might not induce more students to consider psychiatry as a possible career. The present pattern of psychiatry education in Iran seems not to positively affect most aspects of medical students' attitudes toward psychiatry.

Iranian medical students' perception of psychiatry: before and after a psychiatry clerkship.

OBJECTIVE: We aimed to compare the medical students' attitude towards psychiatry before and after psychiatry clerkship, and to examine the association of choosing psychiatry as a future career with some personal characteristics. METHOD: In a self-controlled, quasi-experimental study, all of the medical students entering the psychiatry clerkship in three major medical schools of Iran located in Tehran (Tehran, Shahid Beheshti, and Iran University of Medical Sciences) were asked to participate anonymously in the study on the first and the last 3-days of their psychiatry clerkship. From 346 invited 4th-5th year medical students, 225 (65%) completed anonymous self-report questionnaires before and after a 4-week psychiatry clerkship. RESULTS: Positive response to choose psychiatry as a career was seen in 13.3% and 18.3% before and after psychiatry rotation, respectively. However, the difference was not statistically significant; about one-quarter of the students were turned on to psychiatry and 25% were discouraged during the clerkship. Individual pair wise comparisons revealed significant improvements only in two out of 13 measured aspects of psychiatry. Seventeen out of 38 (47.7%) students who identified psychiatry as the career of choice or strong possibility reported that one of their family members or close friends' mental illness had an impact on their choice. Those students who considered psychiatry as the strong possibility claimed that they are more interested in humanities (OR = 2.96; 95% CI: 1.17, 7.49), and playing a musical instrument (OR = 2.53; 95% CI: 1.15, 5.57). CONCLUSION: It may be concluded that exposure to psychiatry clerkship could influence medical students' opinion about psychiatry positively, or negatively. Personal characteristics and individual interests of students may play an important role in choosing psychiatry as their future career.

Freshmen versus interns' specialty interests.

PURPOSE: The purpose of this study was to determine career preferences of medical students at the time of entering medical school compared with interns who were graduating; and to determine what factors influence the choice of a special discipline as a career. METHODS: A cross-sectional, questionnaire-based survey study involving freshmen and interns at Tehran University of Medical Sciences was conducted in 2006 - 2007. Respondents anonymously completed a specialties questionnaire developed by Feifel et al. The questionnaire was translated into Persian (Farsi) and several items were modified based on the circumstances. RESULTS: The response rate was 91 (73%) among freshmen and 137 (77%) among interns. Forty-six freshman students (50%) and 71 interns (51.8%) indicated that they had not developed a strong decision about any particular field of medicine and needed more time. The preferred specialties among freshmen were surgery and internal medicine; whereas graduating students were more interested in "other specialties". There was no significant difference between pediatrics, gynecology, psychiatry, and general practice among the two groups. There was a significant difference in rating when it came to "anticipated income", "prestige" and "helping patients" of which interns were less interested compared to freshmen in these three areas. CONCLUSION: Approximately one-half of the medical students were unclear about their future goals. The experience of medical school may play a role in diminishing students' interest in surgery and internal medicine as prospective careers.