Whole Genome Sequence Analysis of Two Oxacillin-Resistant and mecA-Positive Strains of Staphylococcus haemolyticus Isolated from Ear Swab Samples of Patients with Otitis Media.

Objective: Staphylococcus haemolyticus can cause a series of infections including otitis media (OM), and the oxacillin-resistant S. haemolyticus has become a serious health concern. This study aimed to investigate the genomic characteristics of two strains of oxacillin-resistant and mecA-positive S. haemolyticus isolated from the samples of ear swabs from patients with OM and explore their acquired antibiotic resistance genes (ARGs) and the mobile genetic elements (MGEs). Methods: Two oxacillin-resistant S. haemolyticus strains, isolated from ear swab samples of patients with OM, underwent antimicrobial susceptibility evaluation, followed by whole-genome sequencing. The acquired ARGs and the MGEs carried by the ARGs, harbored by the genomes of two strains of S. haemolyticus were identified. Results: The two strains of oxacillin-resistant S. haemolyticus (strain SH1275 and strain SH9361) both carried the genetic contexts of mecA with high similarity with the SCCmec type V(5C2&5) subtype c. Surprisingly, the chromosomal aminoglycoside resistance gene aac(6')-aph(2") harbored by S. haemolyticus strain SH936 was flanked by two copies of IS256, forming the IS256-element (IS256-GNAT-[aac(6')-aph(2")]-IS256), which was widely present in strains of both Staphylococcus and Enterococcus genus. Furthermore, the two strains of oxacillin-resistant and MDR S. haemolyticus were found to harbor antimicrobial resistance plasmids, including one 26.9-kb plasmid (pSH1275-2) containing msr(A)-mph(C)) and qacA, one mobilizable plasmid pSH1275-3 harboring vga(A)LC, one plasmid (pSH9361-1) carrying erm(C), and one plasmid (pSH9361-2) carrying qacJ. Conclusion: The systematic analysis of whole-genome sequences provided insights into the mobile genetic elements responsible for multi-drug resistance in these two strains of oxacillin-resistant and mecA-positive S. haemolyticus, which will assist clinicians in devising precise, personalized, and clinical therapeutic strategies for treating otitis media caused by multi-drug resistant S. haemolyticus.

Garcinol prevents oxidative stress-induced bone loss and dysfunction of BMSCs through NRF2-antioxidant signaling.

There are multiple published data showing that excessive oxidative stress contributes to bone loss and even bone tissue damage, and it is also correlated with the pathophysiology of bone degenerative diseases, including osteoporosis (OP). Garcinol, a polyisoprenylated benzophenone derivative, has been recently established as an anti-oxidant agent. However, it remains elusive whether Garcinol protects bone marrow mesenchymal stem cells (BMSCs) and bone tissue from oxidative stress-induced damage. Here, we explored the potential effects of Garcinol supplementation in ameliorating oxidative stimulation-induced dysfunction of BMSCs and bone loss in osteoporotic mice. In this study, we verified that Garcinol exerted potent protective functions in the hydrogen peroxide (H2O2)-induced excessive oxidative stress and dysfunction of BMSCs. Besides, Garcinol was also identified to improve the reduced bone mass and abnormal lineage commitment of BMSCs in the condition of OP by suppressing the oxidative stimulation. Subsequent analysis revealed that nuclear factor erythroid 2-related factor 2 (NRF2) might be a key regulator in the sheltering effects of Garcinol on the H2O2-regulated oxidative stress, and the protective functions of Garcinol was mediated by NRF2-antioxidant signaling. Collectively, Garcinol prevented oxidative stress-related BMSC damage and bone loss through the NRF2-antioxidant signaling, which suggested the promising therapeutic values of Garcinol in the treatment of oxidative stress-related bone loss. Therefore, Garcinol might contribute to treating OP.

A general approach to S-rhodamines from diaryl thioethers and their application in constructing pH probes.

A general strategy for the efficient preparation of S-rhodamines from the condensation of diaryl thioether and 2-carboxybenzaldehydes was reported. We further took a morpholine containing spirolactam structure as an example to illustrate that these S-rhodamine dyes could be utilized to construct fluorescent probes based on the ring-opening process. This work provided a general approach for the synthesis of novel S-rhodamine dyes, thus possibly facilitating the development of fluorescence imaging.

The regulatory roles of miR-26a in the development of fracture and osteoblasts.

Background: MicroRNAs (miRNAs) play a vital role in the bone development and bone regeneration. In this study, we investigated the effects of miR-26a in osteoblasts and fractures. Methods: Human osteoblasts were cultured and used for analysis. To identify differential miRNAs in blood samples from patients with fractures and healthy controls, quantitative real-time polymerase chain reaction (qRT-PCR) analysis was performed. Human osteoblasts were transfected with miR-26a mimics, miR-26a inhibitor, or their corresponding negative controls (NCs), respectively. MTT assay was performed to identify the effects of miR-26a on the cell viability of osteoblasts. EdU staining was applied to detect the proliferation of osteoblasts. Trypan blue staining was utilized to analyze the effects of miR-26a on the cell death of osteoblasts. Terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) staining was used to detect apoptotic osteoblasts. Alizarin red S (ARS) staining and qRT-PCR analysis were utilized to measure the mineralized nodule formation to evaluate the bone formation of osteoblasts. Dual luciferase reporter assay and western blot analysis were performed to detect the relationship between miR-26a and its target gene. Results: The results of qRT-PCR analysis identified miR-26a as our miRNA of interest and indicated that miR-26a was significantly decreased in patients with fractures. Overexpression of miR-26a significantly increased the cell viability and proliferation of osteoblasts. An increase in miR-26a reduced the cell death and apoptosis of osteoblasts, and promoted the osteoblastic activity and mineralized nodule formation. Dual luciferase reporter assay, qRT-PCR and western blot analysis showed that miR-26a could negatively regulate the expression of phosphatase and tensin homolog (PTEN). Conclusions: MiR-26a promoted new bone regeneration via regulating the functions of osteoblasts by targeting its target gene PTEN. Therefore, we propose that targeting miR-26a may be a novel therapeutic method for bone regeneration and treating fractures.

FPGA-Based Two-Dimensional Matched Filter Design for Vein Imaging Systems.

Venipuncture is a common medical procedure. The use of augmented reality-based assistive devices can improve the first puncture success rate in patients with poor vascular filling. In order to improve the image rendering quality and speed of auxiliary equipment, this study develop a two-dimensional matched filtering algorithm on a Field Programmable Gate Array (FPGA) in a near-infrared vein imaging system, which use parallel processing to offer real-time response and is designed as a small handheld portable device. A customized dorsal hand vein image library with 200 images captured from 120 participants is used to analyze the effects of convolution kernel parameters and exposure time on vascular imaging with different depths, and the correlation model between these parameters and vascular depth are constructed. We use the Tenengrad, variance, Laplace smoothness and standard deviation as evaluation indicators, and compare our algorithm with three other related studies. Experimental results show that the rendering quality of our proposed algorithm is significantly higher than other algorithms. In addition, the rendering speed of our algorithm can reach 66 fps, which is twice faster than the current fastest algorithm.

Resveratrol benefits the lineage commitment of bone marrow mesenchymal stem cells into osteoblasts via miR-320c by targeting Runx2.

Bone marrow mesenchymal stem cells (BMSCs) are a potential source of osteoblasts and have been widely used in clinical therapies due to their pluripotency. Recent publications have found that resveratrol (RSVL) played a crucial role in the proliferation and differentiation of BMSCs; however, the underlying molecular mechanism of RSVL-induced BMSCs osteogenic differentiation needs to be fully elucidated. The objective of this study was to explore functions of miRNAs in the RSVL-treated BMSCs and its effects on the differentiation potentials of BMSCs. The findings demonstrated that RSVL enhanced the osteogenesis and suppressed the adipogenesis of BMSCs in a dose-dependent manner. Besides, a novel regulatory axis containing miR-320c, and its target Runx2 was found during the differentiation process of BMSCs under RSVL treatment. Increase of miR-320c reduced the osteogenic potential of BMSCs, while knockdown of miR-320c played a positive role in the osteogenesis of BMSCs. In contrast, overexpression of miR-320c accelerated the adipogenic differentiation, while knockdown of miR-320c restrained the adipogenic differentiation of BMSCs. The results confirmed that Runx2 might be the direct target of miR-320c in RSVL-promoted osteogenic differentiation of BMSCs. This study revealed that RSVL might be used for the treatment of bone loss related diseases and miR-320c could be regarded as a novel and potential target to regulate the biological functions of BMSCs.

MiR-206 regulates the progression of osteoporosis via targeting HDAC4.

BACKGROUND: More and more studies have confirmed that miRNAs play an important role in maintaining bone remodeling and bone metabolism. This study investigated the expression level of miR-206 in the serum of osteoporosis (OP) patients and explored the effect and mechanism of miR-206 on the occurrence and development of osteoporosis. METHODS: 120 postmenopausal women were recruited, including 63 cases with OP and 57 women without OP. The levels of miR-206 were determined by qRT-PCR technology. Spearman correlation coefficient was used to evaluate the correlation of miR-206 with bone mineral density (BMD). An ROC curve was used to evaluate the diagnostic value of miR-206 in osteoporosis. The effects of miR-206 on cell proliferation and cell apoptosis of hFOBs were measured by CCK-8 assay and flow cytometry, respectively. Luciferase reporter gene assay was used to confirm the interaction of miR-206 and the 3'UTR of HDAC4. RESULTS: Serum miR-206 had low expression level in osteoporosis patient group compared with control group. The expression level of serum miR-206 had diagnostic value for osteoporosis, and the serum miR-206 levels were positively correlated with BMD. The down-regulated miR-206 could inhibit cell proliferation and promote cell apoptosis. Luciferase analysis indicated that HDAC4 was the target gene of miR-206. CONCLUSIONS: MiR-206 could be used as a new potential diagnostic biomarker for osteoporosis, and in in vitro cell experiments, miR-206 may regulate osteoblast cell proliferation and apoptosis by targeting HDAC4.

Long noncoding RNA NORAD regulates cancer cell proliferation and migration in human osteosarcoma by endogenously competing with miR-199a-3p.

In this study, we evaluated the expressions and functions of a long noncoding RNA (lncRNA), Noncoding RNA activated by DNA damage (NORAD) in human osteosarcoma. NORAD expressions were evaluated by qRT-PCR in in vitro osteosarcoma cell lines and in vivo clinical specimens. SiRNA-induced NORAD downregulation was conducted in Saos-2 and 143B cells, and the functional effects of NORAD downregulation on osteosarcoma cells were evaluated by CCK-8 proliferation assay, 24-well transwell invasion assay and in vivo tumor explant assay, respectively. The possibility of NORAD endogenously competing microRNA target, hsa-miR-199a-3p was examined by dual-luciferase reporter assay and qRT-PCR. Then, hsa-miR-199a-3p was downregulated in NORAD-inhibited osteosarcoma cells to examine its role in regulating NORAD inhibition induced cancer suppression in osteosarcoma cells. NORAD was found to be significantly overexpressed in both osteosarcoma cells and osteosarcoma tumors. In Saos-2 and 143B cells transfected with NORAD-specific siRNA, their proliferation, invasion, and in vivo explant growth were all markedly suppressed. Hsa-miR-199a-3p was confirmed to be the competing target of NORAD. Its downregulation in Saos-2 and 143B cells inversely augment proliferation and invasion that were initially suppressed by NORAD-downregulation. The results of our study show that NORAD plays an important role in regulating cancer cell functions of osteosarcoma, possibly through endogenously competing with hsa-miR-199a-3p.

Deoxyelephantopin Induces Reactive Oxygen Species-Mediated Apoptosis and Autophagy in Human Osteosarcoma Cells.

BACKGROUND/AIMS: Osteosarcoma is the predominant form of primary bone malignancy. Although the combinational application of neoadjuvant chemotherapy and surgical resection significantly increases the survival rate, the therapeutic outcome remains unsatisfactory. Deoxyelephantopin (DET), an active ingredient of Elephantopus scaber, has been reported to have an anti-tumor effect in recent publications. This study aimed to investigate whether DET has antineoplastic effects on osteosarcoma cells and its underlying mechanism. METHODS: Cell viability and morphological changes were assessed by MTT and Live/dead assays. Cell apoptosis, reactive oxygen species (ROS) and mitochondrial membrane potential were detected utilizing Annexin V-FITC/PI double staining, DCFH-DA and JC-1 probes, respectively. Autophagy was detected by mRFP-GFP-LC3 adenovirus transfection and western blot. RESULTS: DET dose-dependently reduced the viability of osteosarcoma cells following the increase in intracellular ROS levels. Pretreatment with N-acetylcysteine (NAC) reversed this effect. Furthermore, DET induced mitochondrial apoptosis. Depolarized cells were increased, and apoptosis-related proteins, such as Bax, Bcl-2, cleaved caspase-9, cleaved caspase-3 and cleaved ploy ADP-ribose polymerase, were activated. Additionally, we found that DET could induce autophagy in osteosarcoma cells, but autophagy inhibition did not affect the decrease in cell viability. CONCLUSION: DET induced apoptosis in osteosarcoma cells through ROS generation, mitochondrial dysfunction and caspase activation; in addition, autophagy was involved in the effects of DET on osteosarcoma cells.

A New Perspective for Osteosarcoma Therapy: Proteasome Inhibition by MLN9708/2238 Successfully Induces Apoptosis and Cell Cycle Arrest and Attenuates the Invasion Ability of Osteosarcoma Cells in Vitro.

BACKGROUND: The proteasome exists in all eukaryotic cells and provides the main route of intracellular proteins degradation involved in cell growth and apoptosis. Proteasome inhibition could block protein degradation pathways and disturb regulatory networks, possibly leading to profound effects on cell growth, particularly in cancer cells. A proteasome inhibitor with an appropriate toxicity index for malignant cells rather than normal cells would be an attractive anticancer therapy. METHODS: The human osteosarcoma (OS) cell lines MG-63 and Saos-2 and normal osteoblast cells were used to study the antitumour activity of the proteasome inhibitor MLN9708/2238. RESULTS: MLN2238 inhibited cell growth, induced cell cycle arrest and apoptosis, and attenuated the invasion abilities of MG-63 and Saos-2 cells, with little cytotoxicity to normal cells. In addition, MLN2238 promoted antitumour mechanisms including the accumulation of E2F1, P53, P21 and other negative G2/M checkpoint proteins; up-regulated the relative expression ratio of BAX/BCL-2, APAF-1 and pro-apoptotic proteins of the BCL-2 family; triggered mitochondrial outer membrane permeabilization (MOMP); down-regulated BCL-2 and XIAP; activated caspase3/8/9; and suppressed MMP2/9 expression and secretion levels. CONCLUSIONS: The proteasome may be a novel biochemical target for OS treatment in vitro. Our study provides a promising mechanistic framework for MLN9708/2238 in OS treatment, supporting its clinical development.

Evaluation of platelet-rich plasma and fibrin matrix to assist in healing and repair of rotator cuff injuries: a systematic review and meta-analysis.

OBJECTIVE: To perform a meta-analysis examining the effectiveness of platelet-rich plasma and platelet-rich fibrin matrix for improving healing of rotator cuff injuries. Data sources/design: A meta-analysis of eligible studies was performed after searching Medline, Cochrane, and EMBASE on 14 December 2015. SETTING: University hospital. PARTICIPANTS: Patients with rotator cuff injuries. Review methods/intervention: Databases were searched using the keywords "PRP or platelet-rich plasma," "PRFM or platelet-rich fibrin matrix," "rotator cuff," and "platelet-rich" for studies comparing outcomes of patients with rotator cuff injuries that did and did not receive a platelet-rich product. MAIN MEASURES: The primary outcome was a functional score change from pre- to post-treatment (Scorepost-Scorepre). The secondary outcome was a visual analogue scale (VAS) pain score change from pre- to post-treatment (VASpost-VASpre). RESULTS: A total of 11 studies were included in the meta-analysis. The total number of patients that received platelet-rich plasma or platelet-rich fibrin matrix was 320 and the number of control patients was 318. The standard difference in means of the functional scores was similar between patients administered platelet-rich plasma/fibrin matrix and patients in the control group (standard difference in means for functional scores = 0.029; 95% confidence interval (CI): -0.132 to 0.190; p = 0.725). The standard difference in means was similar between patients administered platelet-rich plasma and the controls (standard difference in means = 0.142; 95% CI: -0.080 to 0.364; p = 0.209). CONCLUSION: The results of this meta-analysis do not support the use of platelet-rich plasma/platelet-rich fibrin matrix in patients with rotator cuff injuries.

Long noncoding RNA FGFR3-AS1 promotes osteosarcoma growth through regulating its natural antisense transcript FGFR3.

Long noncoding RNAs (lncRNAs), a new class of RNAs with no protein-coding potential, have been reported to have crucial roles in the regulation of a variety of tumors. However, the functions and molecular mechanisms of lncRNAs to osteosarcoma are still largely unknown. The purpose of this study is to examine the expression, functions and molecular mechanisms of a new lncRNA FGFR3 antisense transcript 1 (FGFR3-AS1) in osteosarcoma. The expression of FGFR3-AS1 was examined by real-time quantitative PCR. The regulation of FGFR3 by FGFR3-AS1 was examined by RNase protection assay, real-time quantitative PCR, western blotting, and luciferase reporter assay. The effects of FGFR3-AS1 on osteosarcoma cell proliferation and cell cycle were determined by Cell Counting Kit-8, Ethynyl deoxyuridine incorporation assay and flow cytometry. FGFR3-AS1 was upregulated in osteosarcoma. Increased FGFR3-AS1 expression correlates with large tumor size, advanced Enneking stage, metastasis and poor survival. Through antisense pairing with FGFR3 3'UTR, FGFR3-AS1 increases FGFR3 mRNA stability and upregulates FGFR3 expression. The expression of FGFR3-AS1 and FGFR3 is positively correlated in osteosarcoma tissues. Knockdown of FGFR3-AS1 inhibits the proliferation and cell cycle progression of osteosarcoma cells in vitro. Moreover, knockdown of FGFR3-AS1 inhibits xenograft tumor growth of osteosarcoma cells in vivo. These data demonstrate the mechanisms of how antisense noncoding RNA regulate the expression of sense genes, and show the pivotal functions of FGFR3-AS1 in osteosarcoma.

A crucial role of IL-17 in bone resorption during rejection of fresh bone xenotransplantation in rats.

Bone grafting is a very useful approach to reconstruction of skeletal defects. However, the clinical use of autografts, allografts, and synthetic products is associated with a number of problems. The use of bone xenotransplantation, on the other hand, is associated with strong immune response, and therefore clear understanding of the mechanisms of immune rejection is essential. In this study, we used rabbit-to-rat xenotransplantation model to investigate the role of IL-17, and the relationship between IL-17, IL-23 and RANKL in inflammatory response during the bone grafting. Rabbit hindlimb bone was transplanted to rats, and half of the xenograft recipient animals received injection of IL-17 neutralizing antibodies before xenotransplantation. Sham control rats did not receive bone transplants. In the xenotransplant group, significant mononuclear cell infiltration and erosion/resorption of graft bone were observed. Administration of IL-17 neutralizing antibodies decreased mononuclear cell infiltration and inhibited bone resorption. The levels of IL-17+, IL-23+, and RANKL+ cells were elevated in xenotransplanted group from compared to the sham control. IL-17+ and RANKL+ cells infiltration was decreased upon administration of IL-17 neutralizing antibodies. No significant difference in the level of IL-23 in xenotransplanted groups with and without IL-17 antibodies was observed. Our results indicate that RANKL, IL-17, and IL-23 participate in the immune rejection of bone xenotransplantion. The IL-17/RANKL pathway may play a very important role in the bone resorption during rejection of fresh bone xenotransplants.

MicroRNA-214 regulates osteosarcoma survival and growth by directly targeting phosphatase and tensin homolog.

An increasing number of microRNAs (miRNAs) have been identified as diagnostic and prognostic biomarkers, as well as additional therapeutic tools, in skeletal diseases. Recent studies have established the pathophysiological role of miR­214, using human osteoporotic bone specimens. However, miR­214 expression levels and the underlying regulatory mechanism in human osteosarcoma remain unclear. Quantitative polymerase chain reaction (qPCR) was used to examine the expression of miR­214 in human osteosarcoma tissues and cells. Transfection of the cells with either a miR­214 expressing­plasmid, mimic or inhibitor was performed, in order to investigate the role of miR­214 in osteosarcoma. In this study, miR­214 was shown to be significantly increased in the majority of 15 examined osteosarcoma tissues and in the Saos­2 human osteosarcoma cell line. Overexpression of miR­214 in Saos­2 cells induced cell proliferation, while inhibition of miR­214 promoted Saos­2 cell apoptosis in vitro. Furthermore, ectopic expression of miR­214 markedly promoted osteosarcoma development in a subcutaneous xenotransplantation model in BALB/c athymic nude mice. The role of miR­214 in osteocarcinogenesis was further investigated and phosphatase and tensin homolog (PTEN) was determined to be a direct target of miR­214 in Saos­2 cells. The proliferation­promoting effect of PTEN knockdown was similar to that of miR­214 overexpression. This study revealed that miR­214 exerted a crucial role in promoting osteosarcoma progression and this suggests that modulation of miR­214 levels may provide a novel therapeutic approach in cancer treatment.

A minimally invasive modified reverse sural adipofascial flap for treating posttraumatic distal tibial and calcaneal osteomyelitis.

Our aim was to report a modified reverse sural adipofascial flap for treating posttraumatic distal tibial or calcaneal osteomyelitis. We retrospectively reviewed the records of 15 patients with posttraumatic distal tibial or calcaneal osteomyelitis treated with modified reverse sural adipofascial flaps between 2005 and 2010. The flap was raised through 2 short incisions in the posterior aspect of the lower leg. The raw surface of the flap was covered with a full-thickness skin graft. Donor sites were closed primarily. Lower Extremity Functional Scale (LEFS) scores and 2-point discrimination (TPD) were recorded preoperatively and postoperatively. There were 12 males and 3 females, with an average age of 39 years (range = 18-55 years). Twelve lesions were in the distal tibia and 3 in the calcaneus. The flap ranged in size from 11 × 5 cm to 16 × 7 cm. All flaps survived, and skin grafts healed without complications. Recipient sites had an anatomic contour, and all patients were able to ambulate without the assistance of special shoes or orthoses. No infections recurred, and no ulcers of the grafted skin occurred with the regular wearing of shoes. The follow-up duration was 18.7 ± 6.8 months (range = 12-36 months). The mean LEFS score increased from 22.4 ± 8.3 preoperatively to 53.0 ± 11.2 postoperatively (P = .001). TPD markedly recovered at 24 months postoperatively. The modified reverse sural adipofascial flap provides good outcomes in treating distal tibial and calcaneal osteomyelitis with minimal donor site morbidity.

Modified distally based sural adipofascial flap for reconstructing of leg and ankle.

BACKGROUND: While free flaps can be used in many cases to cover soft tissue defects in the distal leg and ankle in a single stage, factors such as diabetes and advanced age can interfere with success of vascular anastomoses. METHODS: Twenty-five patients with deep tissue exposure of the distal leg and ankle underwent reconstruction with a modified reverse sural adipofascial flap. Seventeen cases were due to trauma (13 due to high velocity trauma). All 17 had anterior tibial soft tissue defects without significant rear calf soft tissue injury. Eight patients had iatrogenic soft tissue defects due to orthopaedic surgeries for fractures. The flap is raised through two small incisions (3-5 cm) in the posterior aspect of the leg and the subcutaneous fat is split such that some is preserved with the skin. Once the flap is in place, it is covered by a full-thickness skin graft and the donor site is closed primarily. RESULTS: Twenty-one flaps survived. Four had partial loss of the skin graft on the flap, which healed spontaneously without secondary resurfacing. Anatomic contour was obtained in the recipient sites of all 25 patients. All donor sites healed primarily with the preservation of protective sensation in the calf and acceptable aesthetic appearance. Numbness in the lateral dorsal foot improved gradually and only minor residual numbness was noted at 1 year postoperatively. CONCLUSIONS: The modified reverse sural adipofascial flap preserved the sensation of the donor site and the anatomic contour of both recipient and donor sites.

Immune responses following mouse peripheral nerve xenotransplantation in rats.

Xenotransplantation offers a potentially unlimited source for tissues and organs for transplantation, but the strong xenoimmune responses pose a major obstacle to its application in the clinic. In this study, we investigate the rejection of mouse peripheral nerve xenografts in rats. Severe intragraft mononuclear cell infiltration, graft distension, and necrosis were detected in the recipients as early as 2 weeks after mouse nerve xenotransplantation. The number of axons in xenografts reduced progressively and became almost undetectable at week 8. However, mouse nerve xenotransplantation only led to a transient and moderate increase in the production of Th1 cytokines, including IL-2, IFN-gamma, and TNF-alpha. The data implicate that cellular immune responses play a critical role in nerve xenograft rejection but that further identification of the major effector cells mediating the rejection is required for developing effective means to prevent peripheral nerve xenograft rejection.