Ischaemia-reperfusion injury of the peripheral nerve: An experimental study

Although the neuropathology of ischaemic fibre degeneration is relatively well known, its pathogenesis is poorly understood. One of the presumed mechanisms is oxidative stress, causing the breakdown of the blood-nerve barrier (BNB) and ending in lipid peroxidation. We evaluated the effect of ischaemia and reperfusion on the sciatic-tibial nerve of the rat and investigated the biochemical, pathological, and functional evidence of BNB disruption and lipid peroxidation. The distal portion and trifurcation of the sciatic nerve were rendered ischaemic by clamping the femoral vessels for 3 h and followed by varying durations of reperfusion. Reperfusion resulted in an increase in lipid peroxidation beginning from the first hour and increasing until the seventh day, followed by a gradual decline over the following weeks. Nerve oedema and ischaemic fibre degeneration (IFD) consistently became more severe and prominent with reperfusion, indicating that oxidative stress damages the BNB and causes IFD. Results of functional testing by the sciatic function index correlated with other parameters as walking track analysis results got worse as reperfusion periods increased. Impairment of walking patterns was more striking after the first day and continued up to the third week. These data indicate that severe ischaemia of the peripheral nerve results in reperfusion injury, functional impairment, and disruption of the BNB. Microvascular events, which may occur during reperfusion, may be important in amplifying the nerve fibre degeneration that initiated during ischaemia.     

Effect of platelet rich plasma on bone regeneration in maxillary sinus augmentation (randomized clinical trial)

This study evaluates bone quality in sinus augmented with autogenous bone with or without platelet rich plasma (PRP) mix. 15 partially edentulous patients requiring maxillary sinus floor augmentation, followed by implant insertion were studied. In Group I, 5 patients underwent maxillary sinus lifting with autogenous bone augmentation and implant insertion at 6 months post grafting. In Group II, 10 patients underwent maxillary sinus lifting with autogenous bone augmentation mixed with PRP prepared from the patient's own blood with implant insertion at 4 or 6 months post grafting (n = 5 for each implantation time). A core biopsy was taken at the time of implant placement for histological and histomorphometric evaluation. Immediately and 3 months after implantation, Group I showed the statistically significant highest mean bone density (p = 0.046 and 0.022, respectively). At 6 months post-implantation, Group II showed the statistically significant highest mean bone density (p = 0.041). Histomorphometric analysis showed that Group I had the statistically significant highest mean value (39.5 ± 7.4; p = 0.003). Enrichment with PRP did not significantly improve bone density or morphometric value at 3 months post grafting. PRP enriched bone grafts were associated with superior bone density at 6 months post grafting.     

T helper subsets & regulatory T cells: rethinking the paradigm in the clinical context of solid organ transplantation

Recent years have witnessed remarkable expansion in the knowledge of how various immune/inflammatory cells and T helper (Th) cell subsets, including Th1, Th2, Th9, Th17, Th22, follicular T helper (Tfh) and Treg subpopulations, reciprocally regulate each other. This review highlights current understanding of the Th subsets paradigm, who are the old school players, who are the new kids on the block and how does each come to play in different clinical contexts in solid organ transplantation. The article commences with a brief overview of the development and characteristic cytokine profiles of individual members of the paradigm. However, the main focus of this review is on the current understanding of the Th subset paradigm, and how these unique subpopulations impact host responses towards solid organ allografts. More specifically, it will highlight the recent findings that implicate the paradigm in transplantation. The interplay among different subsets is discussed collectively in the clinical context of pretransplant immunological risk factors such as alloimmunization as well as post‐transplant immunological consequences such as rejection. Accumulating evidence suggests that Th17 cells play a role in the development of chronic allograft injury in transplantation of various organs. In vitro, tacrolimus suppressed Th1 and Th2 cells but not Th17 cells. Animal studies suggest that regulatory T cells (Treg)‐based therapies could be effective as mechanisms of long‐term drug‐free transplant tolerance in humans. Indeed, a dual role for TGF‐β and Foxp3 in induced tolerance has been proposed, in which TGF‐β stimulates Foxp3 expression and is associated with the induction of Treg‐facilitating acquisition of tolerance. Exploiting Th subsets' regulatory functions could potentially offer opportunities for immunological interventions in solid organ transplantation.     

Complications in paediatric liver transplant from Kuwait when transplanted abroad

Background and study aimsSince the introduction of liver transplantation (LTx) in children suffering from liver failure in 1963, many centres around the world have offered this service to children that have no other alternative. The aim of this retrospective study is to analyse the results of paediatric liver transplant in Kuwait over the last decade.Patients and methodsA retrospective chart review was done involving paediatric patients during the time period of 1995–2004. The information collected included patient demographics, indications for liver transplantation, survival of both patient and allograft, and complications.ResultsA total of 16 cases were found and analysed. The mean age was 3.6 years (ranged 5 months–17 years). There were nine boys and seven girls. The most common indications for LTx were biliary atresia and metabolic liver disease. All the liver transplants were done abroad. There were totally nine deceased donor and seven living related cases. The complications were acute cellular rejection in five, hypertension in two, biliary complications in four, cytomegalovirus (CMV) infection in three and post lymphoproliferative disease in two cases. All but one patient are presently alive.ConclusionThe above information demonstrates that LTx in Kuwati children is safe and improves the quality of life for those that would otherwise have no other alternative.     

Quantification of silver in several samples using a new ionophore polymer membrane as an optical sensor

Growing concerns about the possible toxicity of silver to aquatic organisms, bacteria, and humans have led to newly issued regulations by the United States Environmental Protection Agency (US EPA) and the Food and Drug Administration (FDA) regarding the use of silver. However, the increase in bacterial resistance to antibiotics has led to a resurgence in the use of silver as a biocidal agent in applications ranging from washing machine additives to the drinking water treatment system on the International Space Station (ISS). For Ag⁺ ion detection, a highly sensitive and reversible optical sensor has been established. The optode relies on a novel Schiff base, namely 2-[(benzo[d]thiazol-2-ylimino)methyl]phenol (BTMP) immobilized within PVC film and also incorporated with tris(2-ethylhexyl)phosphate (TEHP) and Aliquat 336 as an ion carrier. Under optimum conditions (i.e. pH 8.5), the proposed sensor displayed a linear response to Ag⁺ over 4.8 × 10⁻⁹ to 1.0 × 10⁻⁵ M (0.8494–1698.7 μg L⁻¹) with limits of detection and quantification of 1.5 × 10⁻⁹ and 4.8 × 10⁻⁹ M (0.2548 and 0.8494 μg L⁻¹), respectively. The sensor''s response time was found to be 8.0 min. The sensor was applied successfully to determine Ag⁺ ion in some real samples, including food, biological, water, and environmental samples.

Growing concerns about the possible toxicity of silver to aquatic organisms, bacteria and humans have led to newly issued regulations by the United States Environmental Protection Agency and the Food and Drug Administration regarding the use of silver.     

The use of lower turbinate bone grafts in the treatment of saddle nose deformities

Saddle nose reconstruction is based on the use of support grafts to manage aesthetic and functional problems. Bone (calvarial, iliac crest, costal, nasal hump, ulnar, and heterogeneous origin), cartilage (septal, costal, heterogeneous), and synthetic materials (silicon, silastic, polyethylene) were used as support grafts. Three patients have been included in this study to define the surgical management and long-term aesthetic and functional results of patients undergoing rhinoplasty with support grafts for a saddle nose deformity. Open rhinoplasty was employed. Both the lower turbinates were excised and the bone dissected from the soft tissues in two cases and in one case, only mucosa was removed. The amount of support needed was measured by using bone wax. The bone was used shaped in layers, according to the defect, and sutured to each other by vycril suture, and wrapped around by surgicell. The graft was then inserted in its place and fixed with external prolene sutures. Results were satisfactory in both function and aesthetics. Ten to 16-month follow-ups had no complications. Saddle nose surgery basically requires the use of a support graft to repair the nasal dorsum. A lower turbinate bone graft procedure has some advantages: it is cheap and safe, it is ready to use and not time-consuming, there is no donor area and no additional donor site morbidity, and it enlarges the airway and the passage to prevent nasal airway obstruction.     

Giant pilomatrixoma

. Pilomatrixoma is most commonly seen in the head and neck region, occurring in the first two decades of life. It varies from 0.5 cm to 3 cm in diameter. Pilomatrixoma differentiates toward hair cells. Treatment of choice is excision. A 42-year-old woman presented with a giant painful pilomatrixoma, 5 cm in diameter, in the forearm. It had gradually grown larger over a period of years. Physical examination revealed a painful, red-brown colored, ulcerative, mobile mass, 50 mm in diameter, with surrounding hyperemia. Histopathological examination of the specimen provided the diagnosis of "pilomatrixoma". The mass was totally excised, and the resultant tissue defect was repaired with a full-thickness skin graft from the inguinal area. Two years later, there was no recurrence and the postoperative scar was cosmetically acceptable. Generally, there is no recurrence if the pilomatrixoma is totally resected. The case presented in this paper is of interest because the lesion had a large diameter, appeared in the fourth decade, and had a "faceted stone" appearance with perforation of the overlying skin. It is important to differentiate this lesion from a pilomatrix carcinoma.