مجله مطالعات علوم پزشکی
سال سی‌ام شماره 8 (آبان 1398)

Tracheal intubation with a cuffed tube for the administration of general anesthesia is routine. The cuff of the endotracheal tube is inflated with air to achieve an adequate seal to prevent aspiration and leakage of air and anesthetic gases. Whereas over-inflation can decrease the mucosal perfusion, leading to pressure necrosis and nerve palsies. This study aimed to evaluate the change in ETT cuff pressure by changing the position from supine to prone and lateral decubitus without head movement.

During this prospective analytical study, fifty-five patients candidate for surgery under general anesthesia with lateral or prone positions were enrolled. The initial base pressure of the ETT cuff was measured, and the cuff pressure was subsequently adjusted to a normal range. The cuff pressure then was measured after applying the prone or lateral positions and at the end of operation when the patient had the supine position.

The cuff pressure increased significantly after changing position from supine to prone (27.06±2 vs. 36.87 ± 9 cmH2O, p < 0.001). Also, significant increase in cuff pressure was also observed after changing position from supine to lateral decubitus (27.95 ±3 vs. 40.81 ± 10 cmH2O, p < 0.001).

The position change from supine to prone and supine to lateral decubitus without head movement can cause an increase in the endotracheal tube cuff pressure. The necessity of routine monitoring of cuff pressure in these patients is recommended.

In recent years, iron oxide nanoparticles have been used in contrast-enhanced magnetic resonance imaging for diagnosing a wide range of diseases. In order to provide biocompatibility and prevent the toxicity of the nanoparticles, using organic or inorganic coating around these nanoparticles is important for their application. The aim of this study is to investigate the effect of bilayer inorganic (aluminosilicate) and organic (polyethylene glycol) coating around the iron oxide nanoparticles on magnetic resonance imaging contrast.

Iron oxide- aluminosilicate- polyethylene glycol nanocomposite with the size of 170-200 nm was prepared. Magnetic resonance imaging for different concentrations of the nanocomposite was carried out by the use of similar repetition time and different echo times. Mean signal intensities were measured based on applied concentrations, and the curves of spin-spin relaxation times plotted. Transverse relaxivity value was obtained using the slope of spin-spin relaxation rate versus concentration.

Reduction of signal intensity with increasing echo time was observed for all concentrations. The spin-spin relaxation time decreased as a function of the concentration. The transverse relaxivity as a parameter to show magnetic resonance imaging contrast was calculated to be 80.73 s-1.mM-1.

Iron oxide nanoparticles with bilayer aluminosilicate and polyethylene glycol coating can provide negative contrast for magnetic resonance images due to the porous structure of the aluminosilicate, and the possibility of using the nanocomposite for drug delivery according to the presence of polyethylene glycol.

Calcium plays a major role in cellular functions such as transmission, secretion, the activity of fuel enzymes, cell adhesion, and muscle contraction. Disturbance in its cytosolic levels is associated with cellular abnormalities and apoptosis. The purpose of this study was to investigate the effect of different training intensities, and consequent detraining on changes in phospholamban, and sarcolipin, inhibitory proteins involved in the transfer of calcium.

The present research is applied and developmental in terms of purpose and experimental in terms of the method. Thirty-six male Wistar rats (325.66 ± 35.92) were divided into three groups: aerobic training (AE), high intensity interval training (HIIT), and control (CO). The AE and HIIT groups ran on treadmills at speeds of 12 to 15 and 25 to 30 (m/min) for 8 weeks. At the end of eight weeks of training and four weeks of detraining, the samples were killed, and their extensor digitorum longus (EDL) and soleus (Sol) muscles were removed, homogenized, and centrifuged. ELISA test was used to evaluate the content of PLN and SLN proteins. ANOVA, independent t-test, and two-way analysis of variance test (α = 0.05) were used for statistical analysis.

The results of the study showed that there is a significant interactive effect between the exercise intensity and the type of muscle on the content of inhibitory proteins, phospholamban (P = 0.008), and sarcolipin (P = 0.001). In addition, after four weeks of detraining, interactive effect between muscle type and background of training on phospholamban density (p = 0.002) was observed.

It seems that AE exercises in slow-twitch muscles cause more reduction in inhibitory proteins. It also increases the level of inhibitory proteins, especially in the muscle, which reduces the calcium transfer rate.

All organisms struggle to survive and find food. This is the biggest and most important need of all organisms. Meanwhile, food safety is very important. Nanotechnology has penetrated every aspect of human life and plays an important role in the food industry. This technology has changed production and services as well as packaging and specifying the expiration of the food. Metal and metal oxide nanoparticles, chitosan, polymeric nanoparticles, and liposome are the most common particles in the packing and food protection. Here is a review of a number of developments in the nanotechnology over the food industry.

This study was a Nonsystematic Review and was searched through the databases Pubmed, SCOPUS, Web of Science, and Google Scholar with the keywords Nanotechnology, Nanoparticle, Packaging, and Food Science in recent years (2015-2018). There were 852 articles of which 43 papers were selected.

Metal and metal oxide nanoparticles, chitosan nanoparticles, polymer nanoparticles, and liposomes are the most commonly used particles in packaging and food preservation. The use of various nanoparticles and nanoparticle-coated composites, nanofilms, etc. has improved the quality and shelf-life of foodstuffs.

Nanotechnology has been able to influence the food industry as an emerging technology that has entered into all aspects of human life.

Considering the high prevalence of constipation and its possible impact on the outcomes of patients admitted to the intensive care unit, we decided to conduct a retrospective cross-sectional study with the aim of investigating the frequency and consequences of constipation in patients undergoing mechanical ventilation in General Intensive Care Unit (GICU) of Urmia Imam Khomeini Hospital in a 5-years period (2012-2016).

In this study, patients were divided into two groups (with and without constipation). Demographic information, APACHE II score, frequency of constipation, duration of mechanical ventilation, length of staying in intensive care unit, length of hospitalization, and mortality of patients were extracted from clinical records of the patients and entered in the checklist and were statistically analyzed at the end of the study (p <0.05).

The mean duration of mechanical ventilation was 14.37± 10 10.08 days, the mean length of staying in the intensive care unit was 18.67± 11. 11.31 days, and the mean of hospitalization was 28.82 17± 17.71 days. There was a significant difference between the duration of mechanical ventilation, length of staying in ICU, and hospitalization in patients with and without constipation (p <0.05). While there was a statistically significant difference between patients’ mortality and sex (p <0.05).

This retrospective cross-sectional study with a slight difference in the frequency of constipation with confirmation of previous studies showed a relationship among duration of mechanical ventilation, staying in intensive care unit, and hospitalization with constipation. Although no significant difference was found in mortality between the two groups, there was a statistically significant difference between mortality and sex of patients.

 The most commonly used method for external radiation therapy is the use of photons, protons, neutrons, and heavy ions. Hadron therapy is used to eliminate cancerous tissues by using ionizing particles which will bring less damage to healthy tissues.The aim of this study was to evaluate the dose, energy, and flux in a cancerous tumor in the liver and also secondary particles produced by hadrons, which is using the Geant4 Monte Carlo simulation.

In this analytical and applied study by using the Geant4 Monte Carlo Codes, the human body phantom and the tumor that was inserted inside the liver tissue, were simulated. In the method of hadron therapy with different energies, dose deposit, energy, and flux, for carbon and boron were obtained and the approximate area of the target tissue was determined by extrapolation of data.

As observed, as the energy of the beam increases, the peaks become wider and their maximum value (maximum absorbed dose) decreases, because the particle path, depends only on its primary energy. In this study, according to the simulation, the best energy range to start the interaction and Bragg's peak in the tumor area, for boron, is 1805 to 2075 MeV, and for carbon is 2415 to 3015 MeV.

Hadron therapy is more accurate than conventional radiotherapy because of less damage to healthy cells around the tumor. As a result, in the calculated useful energy, the highest dose or destruction caused by radiation is only given to the tumor tissue. The results obtained from the doses, energy, and flux in the simulated liver tissue tumor showed that the hadrons after a long-distance leave the highest dose and energy in the tumor area.

Liver is considered a target organ affected by diabetes mellitus. Exercise training and supplementations could prevent hepatic damage induced by diabetes. The present study was conducted to evaluate the hepatoprotective effects of 6 weeks of endurance exercise and berberine (BBR) usage on streptozotocin (STZ) induced Wistar diabetic rats.

64 healthy male Wistar rats were randomly selected and divided into 8 experimental groups: healthy (N), diabetic (D), diabetic+15 mg/kg BBR (DB15), diabetic+30 mg/kg BBR (DB30), diabetic+aerobictraining+15 mg/kg BBR (DTB15), diabetic + aerobictraining+ 30 mg/kg BBR (DTB30), Non-diabetic+aerobictraining (NT), and diabetic+aerobic training (DT). Diabetes was induced by a single dose of STZ (60 mg/kg, b.w.) given intraperitoneally in sodium citrate buffer. After 6 weeks, blood samples were collected into a plain container for the estimation of alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine transaminase (ALT), and blood glucose. Statistical analysis was done with ANOVA and Bonferroni test using SPSS v. 20 software. The significant level was set at p< 0.05.

The result showed that 30 mg of BBR has lowered blood glucose in diabetic groups (p=0.047). Exercise training alone reduced ALT in group D (p=0.001). In addition, compared to group D, ALP was significantly reduced in 15DB (p=0.016) and 30DBT (p=0.028). There were no significant improvements in other variables.

The results demonstrated that BBR with or without exercise possesses some hypoglycemic and hepatoprotective effects and aerobic exercise alone did not have an important significant effect on these markers in diabetic patients.

One of the objectives of a smooth laryngoscopy is to minimize hemodynamic changes. The goal of this study was to assess the effects of dexmedetomidine and labetalol on heart rate and blood pressure changes after laryngoscopy compared to a control group.

This was a randomized, double-blind clinical trial conducted on 120 patients aged between 18 and 60 years, who were candidates for surgery under general anesthesia at Alzahra Hospital in Isfahan during 2017-2018. Patients were randomly allocated to three groups: dexmedetomidine group, labetalol group, and control group. The patient's age, weight, height, gender, and clinical data including mean blood pressure(BP), heart rate, systolic BP, diastolic BP, and oxygen saturation during 1, 3, 5 and 10 minutes after intubation were collected and analyzed using repeated measure analysis.

The average age of patients who were candidates for surgery was 42.62 +/- 1.40. Fifty-two percent (63 patients) of the subjects were male. The results showed no significant difference in mean BP, diastolic BP, systolic BP or oxygen saturation (p>0.05) in the three groups. But the difference in heart rate between the three groups was statistically significant. The heart rate in the dexmedetomidine group was significantly lower than the labetalol and control groups (p =0.00).

The results of the current study demonstrated that using labetalol provided more desirable hemodynamic stability compared to dexmedetomidine and caused less hemodynamic disturbances.