Mast cells mediate acute kidney injury through the production of TNF

Leukocyte recruitment contributes to acute kidney injury (AKI), but the mechanisms by which leukocytes promote injury are not completely understood. The degranulation of mast cells releases inflammatory molecules, including TNF, but whether these cells participate in the pathogenesis of AKI is unknown. Here, we induced AKI with cisplatin in mast cell-deficient and wild-type mice. Compared with wild-type mice, deficiency of mast cells attenuated renal injury, reduced serum levels of TNF, and reduced recruitment of leukocytes to the inflamed kidney. Mast cell-deficient mice also exhibited significantly lower intrarenal expression of leukocyte chemoattractants. Mast cell-deficient mice reconstituted with mast cells from wild-type mice exhibited similar cisplastin-induced renal damage and serum levels of TNF as wild-type mice. In contrast, mast cell-deficient mice reconstituted with mast cells from TNF-deficient mice continued to demonstrate significant attenuation of cisplatin-induced renal injury. Furthermore, the mast-cell stabilizer sodium chromoglycate also significantly abrogated renal injury in this model of AKI. Taken together, these results suggest that mast cells mediate AKI through the production of TNF.     

Alcohol and interpersonal violence may increase the severity of facial fracture

The association between alcohol and interpersonal violence has been established in studies from a number of countries. We aimed to determine whether alcohol was a contributing factor in the incidence or severity of facial trauma. For 15 months we prospectively studied patients with facial fractures who presented for oral and maxillofacial review. Severity of injury was assessed using the maxillofacial injury severity score (MFISS). Of the 255 patients with facial trauma who presented to our tertiary referral centre, 202 had fractures of the facial skeleton. Most presentations were secondary to interpersonal violence (n=105, 52%), and 91 (87%) of these involved alcohol. Overall, alcohol was involved in 53% of cases (n=107). The relative risk of requiring surgical intervention when alcohol was involved was 1.61 (CI=1.12-2.32). Alcohol significantly increased the severity of facial fracture for both MFISS: alcohol (n=107) mean (SD) 11.43 (7.63); no alcohol (n=95) mean (SD) 6.87 (6.22) (p<0.05). Interpersonal violence also increased the severity of facial fracture: interpersonal violence (n=105) mean (SD) 11.06 (6.68), no interpersonal violence (n=97) mean (SD) 7.37 (7.59) (p<0.05). Patients whose facial fractures are the result of interpersonal violence have more severe injuries and are more likely to require surgery if alcohol is involved. This results in a heavier surgical workload, and is an economic and social burden to the community. Primary prevention strategies will have an important role in reducing such injuries.     

Lead (Pb2+) sorptive removal using chitosan-modified biochar: batch and fixed-bed studies

Chitosan-Modified fast pyrolysis BioChar (CMBC) was used to remove Pb²⁺ from water. CMBC was made by mixing pine wood biochar with a 2% aqueous acetic acid chitosan (85% deacylated chitin) solution followed by treatment with NaOH. The characterizations of both CMBC and Non-Modified BioChar (NMBC) were done using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), scanning electron microscopy (SEM), surface area measurements (S_BET), elemental analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and ζ-potential measurements. Elemental analysis indicated that chitosan accounts for about 25% weight of the CMBC. The Langmuir maximum adsorption capacity of CMBC at pH 5 was 134 mg g⁻¹versus 48.2 mg g⁻¹ for NMBC at 318 K. CMBC column adsorption studies resulted in a capacity of 5.8 mg g⁻¹ (Pb²⁺ conc. 150 mg L⁻¹; pH 5; column dia 1.0 cm; column length 20 cm; bed height 5.0 cm; flow rate 2.5 mL min⁻¹). CMBC removed more Pb²⁺ than NMBC suggesting that modification with chitosan generates amine groups on the biochar surface which enhance Pb²⁺ adsorption. The modes of Pb²⁺ adsorption on CMBC were studied by comparing DRIFTS and X-ray photoelectron spectroscopy spectra before and after Pb²⁺ adsorption.

Batch and fixed-bed column studies for the removal of lead (Pb²⁺) from aqueous solution by chitosan-modified pinewood biochar.