Evaluation and comparison of cytotoxicity, genotoxicity, and apoptotic effects of poly-l-lysine/plasmid DNA micro- and nanoparticles

The principal impediment to gene therapy is the development of efficient, nontoxic gene carriers that can handle and deliver foreign genetic materials into various cell types, including healthy and cancerous cells. Poly-l-lysine (PLL) polymers are one of the most favorable gene carriers among nonviral vectors, and PLL had low transfection and safety issues. The purpose of this study was to measure cellular toxicity, DNA damage, and apoptotic effects of PLL nanoparticles. Neuro2A mammalian cells were cultured and exposed to PLL/DNA complexes at different polymer/DNA ratios ( C/ P ratio 2 and 6) for 24 h. To evaluate metabolic activity, genotoxicity, and apoptotic influences of PLL nanoparticle, the following experimental methods were employed, in order: 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), DNA damage (COMET analysis) assay, and sub-G1 peak apoptosis assay. Our data indicate that toxicity is concentration dependent and a high concentration of polymer declined the metabolic activity. In addition, largest complexes ( C/ P 6 in HEPES buffered saline buffer) have slighter negative impact on metabolic activity. In agreement with our cytotoxicity data, apoptotic assay result represented that increase in size of PLL/DNA complexes decrease the number of apoptotic cells. Also, there was a remarkable increase in percent tail DNA of Neuro2A cells treated with higher concentration of PLL and its polyplexes. The present study demonstrated that PLL/DNA complexes caused cytotoxic, apoptotic, and genotoxic effects in a dose-dependent and weight ratio-dependent manner, which also affected the size of polyplexes.

Assessment of safety culture among job positions in high-rise construction: a hybrid fuzzy multi criteria decision-making (FMCDM) approach

The construction industry is known as one of the most dangerous industries, which not only requires sound operation of executive laws and regulations, but also necessitates the safety culture of all workers at workshops. Therefore, the aim of this research is to identify the factors of safety culture and ranking occupations in jobsites based on those factors in order to proactively improve the safety culture of construction projects and subsequently promote safety conditions and worksites. In this study, safety culture criteria are weighted by a combination of Fuzzy Decision Trail and Evaluation Laboratory and Fuzzy ANP methods. Next, different job positions in high-rise projects are ranked using the Fuzzy Technique for Order of Preference by Similarity to Ideal Solution method. Findings demonstrated that the project manager, site superintendent and supervisor occupations had the highest and labourers had the lowest level of safety culture in the high-rise construction industry. Furthermore, factors such as safety supervision and training must be considered more seriously in order to create a positive safety culture among workers.

Micrometastasis in colorectal cancer: does it affect staging?

BACKGROUND

Micrometastasis (MM) in colorectal cancer (CRC) is not considered in tumour-node-metastasis (TNM) staging currently and also the prognostic significance of these occult tumoural cells is not proven yet. This study was designed to find whether MM to bone marrow (BM) and/or liver cause upstaging of the tumour according to conventional staging system and if it may alter the survival rate.

METHODS

Thirty-eight CRC patients who were candidates of surgical procedure were enrolled in our cross-sectional study. Liver and BM biopsy were obtained during the surgery to be looked for tissue-specific marker of CRC, CK20. CK20 expression in BM and liver was assessed by the two methods of reverse transcriptase polymerase chain reaction and immunohistochemistry.

RESULTS

Among the 38 submitted patients, a total number of 14 MM, including 10 BM (23%) and seven hepatic (18%) were detected. There was no significant difference in clinicopathological aspects including size, location, stage, grade, local invasion to vessels and neurons, TNM staging and relapse rate of tumour among patients with/without disseminated tumoural cells. The result did not demonstrate a survival difference between patients receiving neoadjuvant chemotherapy compared to other patients.

CONCLUSION

Our study did not confirm that the presence of MM influences TNM staging and overall survival of the patients. Additional clinical investigations with longer follow-up period and larger number of cases are required to decide on administration of neoadjuvant therapy in CRC patients.

Bcl-2 associated athanogene-1 overexpression in diffuse large B-cell lymphoma

BACKGROUND

Apoptosis and cell cycle regulation play an important role in pathogenesis and tumor progression in patients with Diffuse Large B-Cell Lymphoma (DLBCL). Bcl-2 associated athanogene-1 (BAG-1) is an antiapoptotic protein as well as a regulator of cell growth. There is no conclusive evidence about BAG-1 protein expression in this disease.

OBJECTIVE

To investigate the expression level of BAG-1 protein in DLBCL.

METHODS

Thirty patients diagnosed from 1997-2004, as having DLBCL, were selected. Also 30 normal lymph nodes were included as normal counterparts in this study. BAG-1 expression was determined by immunohistochemical staining in both DLBCL and normal lymph node samples.

RESULTS

Of the 30 DLBCLs examined, 100% were positive for nuclear and 83% were positive for cytoplasmic BAG-1 staining. Of the 30 normal lymph nodes investigated, 20% were positive for nuclear and 0% were positive for cytoplasmic BAG-1 staining. Nuclear staining in DLBCL samples was significantly higher than those of normal lymph nodes (100% versus 20%, p <0.001). Besides, cytoplasmic staining in DLBCL samples was significantly higher than those of normal lymph nodes (83% versus 0%, p <0.001). There was no association between BAG-1 staining and patients' overall survival.

CONCLUSION

Our data indicated that BAG-1 protein was deregulated in this disease similar to some other malignancies such as breast and colon cancer. Overexpression of BAG-1 in DLBCL suggests that this protein probably plays an important role in the pathogenesis of DLBCL. Besides, higher nuclear BAG-1 staining might be correlated with poor prognosis.

Single-versus multiple-dose antibiotics prophylaxis for cardiac surgery

BACKGROUND

This study was carried out to determine if single-dose antimicrobial prophylaxis is sufficient for cardiac surgery.

METHODS

The study was a prospective non-randomized trial of 353 consecutive patients undergoing cardiac surgery. Group A (n = 151) received 48 h of prophylaxis and Group B (n = 202) received a single dose. Cephazolin was used in all patients except those at high risk from methicillin-resistant Staphylococcus aureus (MRSA) who received teicoplanin and timentin.

RESULTS

There was an overall in-hospital infection rate of 2.8%. There was no significant difference in rate or type of infection between the two groups.

CONCLUSIONS

An in-hospital infection rate of 2.8% compares favourably with other reported series. Single-dose antimicrobial prophylaxis is as effective as a 48-h regimen. Targeting high-risk groups is effective.

Right aortic arch with aberrant left subclavian artery: aneurysmal dilatation causing symptomatic compression of the right main bronchus in an adult

A 60-year-old woman presented with a cough, nocturnal stridor and dysphagia. Bronchoscopy showed tight compression of the right main bronchus. Digital subtraction angiography (DSA) and a computed tomographic (CT) scan showed the presence of a right-sided aortic arch with aberrant left subclavian artery. The distal right arch and proximal right-sided descending thoracic aorta were aneurysmal and were responsible for this compression. Surgical relief was accomplished by dividing the aberrant left subclavian artery and replacing the aneurysm with a vascular graft.

Clinical trial of levamisole in the treatment of ascariasis in Khorasan, Iran

This paper identifies the parasitic infections and their incidence in 246 people aged between 10--20 years living in a semi-rural Iranian village. 64 patients with ascariasis were treated with levamisole ('Ketrax' ICI) in accordance with the manufacturer's instructions. Most were followed up 1 and 2 weeks after treatment, with cure rate of 97.7% and 98.4% respectively, as assessed by negative egg findings in faeces. No side effects were reported. Levamisole meets the requirements of individual and mass treatment of ascariasis.