Modulation of Macrophage Polarization for Bone Tissue Engineering Applications

Innate immune cells play a crucial role in bone development and repair. Macrophages are the main effector cells in immune responses to implants and are indispensable for bone healing success. The heterogeneity and plasticity of macrophages make them a prime target for immune system modulation to enhance bone repair and regeneration. It is believed that the polarization of macrophage phenotype towards the anti-inflammatory M2, rather than the inflammatory M1 phenotype, promotes osteogenesis. Tissue-engineered bioimplants are potentially capable of producing signals to modulate macrophage polarization. Therefore, development of smart immunomodulatory bioimplants via manipulation of their properties seem a promising strategy for tuning immune responses to optimize bone repair without any unwanted inflammatory reactions. The purpose of the present review is to summarize the currently available studies performed on the effects of macrophage polarization, especially towards M2 phenotype, both in bone repair and in bioimplant-stimulated osteogenesis. Moreover, this literature highlights the need to focus future studies on the development of smart immunomodulatory implants capable of switching macrophage polarization-enhancing bone implant-host tissue integration.

Randomized controlled trial on the comparison of chest tube drainage and needle aspiration in the treatment of primary spontaneous pneumothorax

Objectives

To evaluate the efficacy of the chest tube drainage (CTD) and the needle aspiration (NA) in the treatment of primary Spontaneous pneumothorax (SP).

Methods

In a randomized controlled trial, seventy patients suffering SP were divided equally into two subgroups, as follows: (A) CTD and (B) NA. The immediate and one-week rate of the treatments was the primary endpoints. Postoperative complications, length of hospital stay and incidence of pneumothorax recurrence during one-year follow up were also recorded.

Results

The immediate success of treatment was 68.5% and 54.2% of patients in CTD and NA groups, respectively that showed no significant difference between study groups (P: 0.16). The complete lung expansion after one week observed in 32 (91.4%) of NA group and 33 (94.2%) patients in CTD group (P: 0.5). Pneumothorax recurrence was detected in 13 patients (4 in NA and 9 in CTD group) (P: 0.11). Mean pain intensity was significantly lower in the NA group at the first hour after the procedure, the first postoperative day and the first week after the intervention (P< 0.001).

Conclusion

Needle aspiration (NA) can be applied as a first step treatment in patients with primary SP, considering its advantages.

Modulation of Macrophage Polarization for Bone Tissue Engineering Applications

Innate immune cells play a crucial role in bone development and repair. Macrophages are the main effector cells in immune responses to implants and are indispensable for bone healing success. The heterogeneity and plasticity of macrophages make them a prime target for immune system modulation to enhance bone repair and regeneration. It is believed that the polarization of macrophage phenotype towards the anti-inflammatory M2, rather than the inflammatory M1 phenotype, promotes osteogenesis. Tissue-engineered bioimplants are potentially capable of producing signals to modulate macrophage polarization. Therefore, development of smart immunomodulatory bioimplants via manipulation of their properties seem a promising strategy for tuning immune responses to optimize bone repair without any unwanted inflammatory reactions. The purpose of the present review is to summarize the currently available studies performed on the effects of macrophage polarization, especially towards M2 phenotype, both in bone repair and in bioimplant-stimulated osteogenesis. Moreover, this literature highlights the need to focus future studies on the development of smart immunomodulatory implants capable of switching macrophage polarization-enhancing bone implant-host tissue integration.

Prevalence and characteristics of colorectal polyps in symptomatic and asymptomatic Iranian patients undergoing colonoscopy from 2009-2013

BACKGROUND

Colorectal cancer is the third most common type of cancer in males and the second in females in Iran. Males are more likely to develop CRC than women and age is considered as a main risk factor for colorectal cancer. Prevalence of colorectal cancer has been increasing in Asian countries.

AIM

The object of this study was to determine the clinical and pathology characteristics of colorectal polyps in Iranian patients and to investigate the variation between our populations with other populations.

MATERIALS AND METHODS

A total of 167 patients with colorectal polyps were included in our study. All underwent colonoscopy during 2009-2013 and specimens were taken through polypectomy and transferred to pathology. All data in patient files including pathology reports were collected and analyzed by SPSS 16 software. A two-tailed test was used and a P-value of <0.05 was considered significant.

RESULTS

Mean age of participants was 57±15. Some 84 were females (50.3%) and 83 males (49.7%). Total of 225 polyps were detected which 119 (52.9%) were in males and 106 (47.1%) were in females. Solitary polyps were observed in 124 patients (74%), 26 (15.6%) had two polyps and 17 (10.1%) with more than two polyps (three to five). Rectosigmoid was the site of most of the polyps (63.1%), followed by 19.6% in the descending colon, 7.6% in the transverse, 5.8% in the ascending, and 3.1% in the cecum, data being missing in two cases.

CONCLUSIONS

Recto sigmoid was site of most of the polyps. The most prevalent type of lesion was adenomatous polyps detected in 78 (34.7%). Mixed hyperplastic adenomatous type observed in 70 (31.1%). This high prevalence of adenomatous polyps in Iranian patients implies the urgent need for screening plans to prevent further healthcare problems with colorectal cancer in the Iranian population.

Human erythropoietin effect in postoperative visual loss following spine surgery: a case report

Introduction:

Postoperative visual loss (POVL) has become the focus of attention for anesthesiologists as a hallmark of perioperative management in spine surgery. A number of Intraoperative and postoperative factors has been documented but the exact etiology is still unclear. Nowadays, perioperative management and also complete curing of POLV is a big question of ophthalmologists and anesthesiologists. The purpose of this case report is to present a unique experience of complete curing the POLV.

Case Presentation:

Our patient was a 61-year-old man, with 75 kg weight and 180 cm height. The patient had no history of visual impairment except mild cataract in his right eye. The patient had a history of diffuse idiopathic skeletal hyperostosis (DISH). The patient had undergone lumbar surgery in prone position. The operation time was about 6 hours. About 30 minutes after transferring to postanesthesia care unit (PACU), patient was awake and complained of losing his eyesight. There was no vision and light perception in his right eye on primary examination. Urgent ophthalmologist consultation was requested. In ophthalmology examinations, the pupil reflex to light was absent in the right eye. After obtaining patients and his family informed consent, four hours after the operation, 40000 I.U. of recombinant human erythropoietin (rhEPO) was administered for patient in PACU (IV infusion, in 30 min). An ophthalmologist visited him every 6 hours after administration of rhEPO. The patient was transferred to intensive care unit (ICU) one hour later with total visual loss in the right eye. Ophthalmologic examination after the second dose of rhEPO, 30 hours after the operation, reported pupil reflex enhancement and light perception in his right eye. Finally the third dose of rhEPO (40000 I.U., IV infusion) was administered on the third day. Ophthalmologic examination after the third dose of rhEPO, 60 hours after the operation, reported normal pupillary light reflex of the right eye and visual acuity improvement to 20/20. The patient was discharged from hospital after six days, with normal visual acuity and without any new complications except surgical site pain.

Conclusions:

Our case report showed the therapeutic effect of rhEPO in complete curing of POVL. Regarding the side effects of EPO such as thrombogenic effects or mild hemodynamic changes like transient sinus tachycardia during infusion, it seems that beneficial effects of EPO is more than its disadvantages and expenses, for patients with POVL.