Microorganism-derived biological macromolecules for tissue engineering / 医学前沿

According to literature, certain microorganism productions mediate biological effects. However, their beneficial characteristics remain unclear. Nowadays, scientists concentrate on obtaining natural materials from live creatures as new sources to produce innovative smart biomaterials for increasing tissue reconstruction in tissue engineering and regenerative medicine. The present review aims to introduce microorganism-derived biological macromolecules, such as pullulan, alginate, dextran, curdlan, and hyaluronic acid, and their available sources for tissue engineering. Growing evidence indicates that these materials can be used as biological material in scaffolds to enhance regeneration in damaged tissues and contribute to cosmetic and dermatological applications. These natural-based materials are attractive in pharmaceutical, regenerative medicine, and biomedical applications. This study provides a detailed overview of natural-based biomaterials, their chemical and physical properties, and new directions for future research and therapeutic applications.

Seroprevalence of toxoplasmosis among women referring to Shahid Beheshti hospital, Hamadan, Iran

Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii. The aim of this study was investigate the prevalence of toxoplasmosis among young women who referred to check up for toxoplasmosis attended in Shahid Beheshti hospital, Hamadan during 2013-2014. This study was performed on 2523 pregnant women who referred to laboratory of Shahid Beheshti hospital in Hamadan province [western of Iran] during 2013-2014. Age, level of education and place of residence were recorded in the relevant forms. Antibodies serum levels for all samples were examined by ELISA. IgG titer equals and more than 1:200 was presumed as seropositive. Data were analyzed using by SPSS version 19.0 software. 26.1% of IgG seropositive persons were city residents while 32.3% of them lived at village and suburb of city. 1.4% and 1.1% of at risk persons [based on IgG titration] were city and village residents, respectively. 1.3% and 1.9% of IgM seropositives were city and village residents, respectively. The percentage of at risk persons of city and village [based on IgM titration] were 0.3% and 0.6%, in a row. 29.7% of IgG seropositives did not have academic education while 30.4% of them graduated from high school, at least. The seropositive IgM percentage of non-academic educated persons and graduated/academic ones were 1.7% and 1.4%, respectively. Our funding indicates the association between age of women and their level of education with percentage of contamination and prevalence. IgM seropositive is lesser than IgG. It means that toxoplasmosis is chronic or there is previous contact. To avoid the risk of toxoplasmosis infection particularly in pregnant women should be examined and the necessary preventive measures and training for young women should be presented

Seroprevalence of hepatitis B virus Infection by quantitative chemiluminescent in Tabriz [north west of Iran], 2010-2011

Hepatitis B is considered as one of the most common infectious diseases. The contamination of this virus has caused hygienic problems all over the world. Liver cirrhosis and hepatocellular carcinoma are most important consequences of this disease. The purpose of this study is to determine the rate of infection in Tabriz North West of Iran. This study is carried out, on partial and short time basis between 2010 and 2011, on test results of 21421 examined individuals whom have visited clinics in Tabriz. HBsAg of the samples was analyzed with chemiluminescence apparatus and finally, SPSS software was used to conduct the statistical examination of the results. Among 21421 examined individuals [5021 cases in 2010 and 16400 cases in 2011], 594 samples [2.77%] were reported positive and 20827 samples [97.23%] were reported negative. According to the results, gender was not a determining factor affecting the susceptibility of patients. Our country is endemic to this disease, so diagnostic and preventive methods are crucial, more over comprehensive national vaccination can help to noticeably reduce the infectious cases caused by the disease

Cell-Penetrating Peptides [CPPs]: a tool in modern biotechnology

The major limitation in the application of bioactive molecule is their low permeation across plasma membrane. In 1988 it was discovered, that a natural polycationic protein, the trans-acting activator of transcription [TAT] of the human immunodeficiency virus [HIV-1], passed very efficiently through cell membrane of cultured mammalian cells. TAT became known as the first cell penetrating peptide [CPP]. CPPs have demonstrated themselves to be capable of delivering biologically active cargo to the cell interior and the vehicular capabilities of CPPs have already been harnessed for use as laboratory tools. Attached to a CPP, therapeutic cargo could be delivered to an intracellular target, thus overcoming the entry restrictions set by the plasma membrane. Since the discovery of TAT, the number of known peptides with cell-penetrating capabilities has grown and in 2003, the first CPP-based drug reached phase II clinical trials. In this review we introduce and discuss the current knowledge of CPPs

Comparison of prophylactic effects of polyurethane cylindrical or tapered cuff and polyvinyl chloride cuff endotracheal tubes on ventilator-associated pneumonia

Because microaspiration of contaminated supraglottic secretions past the endotracheal tube cuff is considered to be central in the pathogenesis of pneumonia, improved design of tracheal tubes with new cuff material and shape have reduced the size and number of folds, which together with the addition of suction ports above the cuff to drain pooled subglottic secretions leads to reduced aspiration of oropharyngeal secretions. So we conducted a study to compare the prophylactic effects of polyurethane-cylindrical or tapered cuff and polyvinyl chloride cuff endotracheal tubes [ETT] on ventilator-associated pneumonia. This randomized clinical trial was carried out in a 12 bed surgical intensive care unit. 96 patients expected to require mechanical ventilation more than 96 hours were randomly allocated to one of three following groups: Polyvinyl chloride cuff [PCV] ETT, Polyurethane [PU] cylindrical Sealguard ETT and PU Taperguard ETT. Cuff pressure monitored every three hours 3 days in all patients. Mean cuff pressure didn't have significant difference between three groups during 72 hours. Pneumonia was seen in 11 patients [34%] in group PVC, 8 [25%] in Sealguard and 7 [21%] in Taperguard group. Changes in mean cuff pressure between Sealguard and PVC tubes and also between Taperguard and PVC tubes did not show any significant difference. There was no significant difference in overinflation between three groups. The use of ETT with PU material results in reducing ventilator-associated pneumonia compared to ETT with PVC cuff. In PU tubes Taperguard has less incidence of ventilator-associated pneumonia compared to Sealguard tubes

Nasogastric tube placement errors and complications in pediatric intensive care unit: a case report

Nasal ala pressure sores are among complications of nasogastric tube in Pediatric Intensive Care Unit [PICU]. The severity of the injury is usually minor and easily ignored. However, the complication could be easily avoided. This is a case of nasal ala sore after the placement of nasal enteral tube in a pediatric intensive care unit in our center. A 5-month-old female with pulmonary hypertension secondary to bronchiectasis with nasal ala pressure sore were reported. She was hospitalized in pediatric intensive care unit at Tabriz Children Hospital in 2010.After 53 days of PICU hospitaliza-tion she had nasal ala sore. Conclusion: We know that nasal ala pressure sores could easily be avoided when preventive procedures were performed during nasogastric tube insertion