External wire-frame fixation of digital skin grafts: A non-invasive alternative to the K-wire insertion method

Background and Aim

The current skin graft fixation methods for digits, including the Kirschner wire insertion technique, can be limited by inadequate or excessive fixation and complications such as infection or secondary injuries. Therefore, the external wire-frame fixation method was invented and used for skin grafting of digits. This study aimed to investigate external wire-frame fixation of digital skin grafts as a non-invasive alternative to the K-wire insertion method.

Methods

In 2005–2012, 15 patients with burn scar contractures on the hand digits received a skin graft that was then fixed with an external wire frame. The intra-operative time needed to make the wire frame, the postoperative time to frame and suture removal, the graft survival rate, the effect of contracture release and the complications were recorded.

Results

In all cases, the contracture release was 100%. The complete graft survival rate was 98.6%. Four patients had epithelial necrosis in <5% of the total area. There were no other complications such as pressure ulcer or hypoxia of fingers.

Conclusions

External wire-frame fixation is simple, minimally invasive and a custom-made technique for skin grafting of the fingers. It was designed for its potential benefits and the decreased risk it poses to patients with scar contractures on their fingers. It can be implemented in three phases of grafting, does not affect the epiphyseal line or subsequent finger growth and is suitable for children with multi-digit involvement.     

Difference between periportal and pericentral Kupffer cells in uptaking lipopolysaccharides in rats

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Second window of ischemic preconditioning regulates mitochondrial permeability transition pore by enhancing Bcl-2 expression

OBJECTIVE: The second window of protection (SWOP) following brief coronary artery occlusion begins at 24 h and may last up to 72 h and occurs via many unknown mechanisms. We investigated the role of the mitochondrial permeability transition pore (PTP), a non specific pore in the inner membrane of the mitochondria in this phenomenon. METHODS: Ischemic preconditioning (IP) was induced in Wistar rats by left coronary artery occlusion (four, 3-min episodes separated by 10 min of reperfusion) on day 1. On day 2, ischemia was induced with 30 min of ischemia and 120 min of reperfusion in IP and control rats. RESULTS: IP rats showed decreased myocardial infarction (MI) area vs. non-IP control rats (15.32 vs. 45.6%). Furthermore, IP rats had preserved cardiac function (heart rate, rate pressure product, coronary flow and aortic flow) and myocardial ATP (P<0.03), decreased tissue water content (73.2 vs. 90.6%), increased expression of Bcl-2, and less mitochondrial swelling, cytochrome C release and apoptosis (2.6 vs. 12.4%) when compared to sham-operated rats. Activation of the permeability transition pore with PTP activators lonidamine (10 mg/kg body weight) or atractyloside (5 mg/kg body weight) before the sustained ischemia on day 2 resulted in complete abolition of SWOP-mediated cytoprotective effects. These agents had no effect on the cytoprotective effects that took place during the first window of preconditioning. CONCLUSION: The cytoprotective effects of SWOP are dependent on PTP activation state and may involve upregulation of Bcl-2 expression.     

A Case Report of the Histologic Transformation of Primary Follicular Lymphoma of the Duodenum

A 46-year-old woman underwent upper endoscopy for evaluation of anemia, which revealed whitish granules at the duodenal papilla, diagnosed as duodenal follicular lymphoma (DFL) by biopsy. Computed tomography and abdominal ultrasonography revealed that follicular lymphoma was confined to the duodenum. Seven years after the diagnosis, fluorine-18 fluorodeoxyglucose positron emission tomography scanning revealed multiple lesions including in bone marrow and lymph nodes. Bone marrow biopsy of the right iliac bone revealed diffuse large B-cell lymphoma, indicating systemic dissemination and histologic transformation of the DFL. The patient responded to chemotherapy and has been progression-free for 2.5 years. Although DFL is usually indolent even without any treatment, systemic dissemination with histologic transformation can occur. This case suggests that the life-time follow-up that is usually done for patients with nodal follicular lymphoma should be provided to patients with DFL.     

The Impact of Endogenous Breast Cancer Resistance Protein on Human P-Glycoprotein-Mediated Transport Assays Using LLC-PK1 Cells Transfected With Human P-Glycoprotein

Lilly Laboratories cell porcine kidney 1 (LLC-PK1) cells transfected with human P-glycoprotein (LLC-PK1-P-gp) are widely used in transport assays to identify drug candidates that function as substrates of this efflux transporter. Endogenous transporters expressed in LLC-PK1 cells may complicate the interpretation of findings from P-gp-mediated transport assays. We investigated the impact of porcine breast cancer resistance protein (Bcrp) in P-gp-mediated transport assays in LLC-PK1 cells. Porcine Bcrp mRNA was detected in both LLC-PK1 wildtype (WT) and LLC-PK1-P-gp cells by quantitative RT-PCR. To investigate the activity and impact of porcine Bcrp, we conducted transport assays using 6 typical BCRP substrates in LLC-PK1 cells. Efflux ratios (ER) of the 6 BCRP substrates in LLC-PK1 WT cells were >2, and were reduced in the presence of the BCRP inhibitor Ko143. The efflux activities of the 6 BCRP substrates were confirmed using MDCKII cells transfected with human BCRP. Net ERs of prazosin and fluvastatin, dual substrates of P-gp and BCRP, determined by dividing ERs in LLC-PK1-P-gp cells by those in LLC-PK1 WT cells, were <2, but increased to >2 in the presence of Ko143. These results indicated that endogenous Bcrp in LLC-PK1 cells was involved in the transport of BCRP substrates and may interfere with the identification of P-gp substrates.     

Murine CD27(?) Vγ6(+) γδ T cells producing IL-17A promote ovarian cancer growth via mobilization of protumor small peritoneal macrophages

Cancer-associated inflammation mobilizes a variety of leukocyte populations that can inhibit or enhance tumor cell growth in situ. These subsets include γδ T cells, which can infiltrate tumors and typically provide large amounts of antitumor cytokines, such as IFN-γ. By contrast, we report here that in a well-established transplantable (ID8 cell line) model of peritoneal/ovarian cancer, γδ T cells promote tumor cell growth. γδ T cells accumulated in the peritoneal cavity in response to tumor challenge and could be visualized within solid tumor foci. Functional characterization of tumor-associated γδ T cells revealed preferential production of interleukin-17A (IL-17), rather than IFN-γ. Consistent with this finding, both T cell receptor (TCR)δ-deficient and IL-17–deficient mice displayed reduced ID8 tumor growth compared with wild-type animals. IL-17 production by γδ T cells in the tumor environment was essentially restricted to a highly proliferative CD27⁽⁻⁾ subset that expressed Vγ6 instead of the more common Vγ1 and Vγ4 TCR chains. The preferential expansion of IL-17–secreting CD27⁽⁻⁾ Vγ6⁽⁺⁾ γδ T cells associated with the selective mobilization of unconventional small peritoneal macrophages (SPMs) that, in comparison with large peritoneal macrophages, were enriched for IL-17 receptor A, and for protumor and proangiogenic molecular mediators, which were up-regulated by IL-17. Importantly, SPMs were uniquely and directly capable of promoting ovarian cancer cell proliferation. Collectively, this work identifies an IL-17–dependent lymphoid/myeloid cross-talk involving γδ T cells and SPMs that promotes tumor cell growth and thus counteracts cancer immunosurveillance.Developing tumors are infiltrated by a variety of leukocyte subsets that can either promote or inhibit inflammation, and thus impact on cancer progression (1). Among such populations are γδ T cells, which are major players in lymphoid stress surveillance likely due to their recognition of stress-inducible molecules independently of MHC-mediated antigen presentation (2). Moreover, abundant IFN-γ secretion and cytotoxic effector functions endow γδ T cells with potent antitumor activity. This has been clearly documented in murine models of spontaneous (3), chemically induced (4), transgenic (5), and transplantable (6, 7) tumors. For example, in the widely used B16 melanoma model, γδ T cells were shown to infiltrate tumors very early and provided a critical source of IFN-γ that significantly delayed tumor growth (6, 7).Human γδ T cells also possess IFN-γ–secreting potential, which is displayed immediately at birth (8) and display cytotoxicity against tumor lines of diverse origin, including epithelial (9, 10) and hematological (11, 12) tumors. This has prompted the development of cancer clinical trials targeting γδ T cells, which have produced encouraging, albeit highly variable, degrees of therapeutic responses (13–15). There is therefore great interest in maximizing the antitumor functions of γδ T cells for cancer immunotherapy.Despite these highly promising reports, a clinical study on breast cancer tissue revealed a surprising inverse correlation between infiltrating γδ T cells and overall patient survival (16). In fact, γδ T cells represented the most significant independent prognostic factor for assessing severity of breast cancer (16). Similarly, a recent report on colorectal cancer showed a positive correlation between clinopathological parameters and the infiltration of γδ T cells specifically producing interleukin-17 (IL-17) (17). A tumor-promoting function of γδ T cells was also suggested in murine fibrosarcoma (18) and hepatocellular carcinoma (19) models, in which γδ T cells were the major cellular source of IL-17, which was required for optimal tumor growth in vivo. These data raise the interesting question as to whether distinct functional attributes of γδ T cells, for example differential cytokine production, may associate with markedly different outcomes for tumor growth.Along these lines, we have pioneered the identification of two distinct functional subsets of murine γδ T cells based on the expression levels of the CD27 coreceptor (20). We showed that robust IFN-γ production is associated with the CD27⁽⁺⁾ phenotype, whereas secretion of IL-17 is restricted to CD27⁽⁻⁾ γδ T cells. This dichotomy of hard-wired commitment to specific cytokine production is established during thymic development and maintained during the immune response to various infection agents (21, 22). Thus, the overall impact of γδ T cells in a given disease may depend on the balance between distinct proinflammatory effector cell subsets.Building on these foundations, we have here analyzed the overall and subset-specific contributions of γδ T cells to a well-established murine syngeneic model of ovarian cancer (ID8; transplantable cell line) that has a strong inflammatory component (23–25), akin to that observed in human patients with high-grade serous ovarian cancer (25, 26). In this murine model, we demonstrate that γδ T cells are major sources of IL-17, and both T cell receptor (TCR)δ-deficient and IL-17–deficient mice display reduced ID8 tumor growth. Interestingly, IL-17 production by γδ T cells in the tumor environment is essentially restricted to a CD27⁽⁻⁾ subset that does not express the commonly used Vγ1 or Vγ4 TCR chains, but rather Vγ6; these Vγ6⁽⁺⁾ cells are highly biased toward IL-17 production, in contrast to their IFN-γ–producing Vγ1⁽⁺⁾ and Vγ4⁽⁺⁾ counterparts. The ID8 tumor environment gets progressively enriched in the IL-17–promoting factor IL-7, whose receptor is highly expressed on Vγ6⁽⁺⁾ cells. This associates with preferential Vγ6⁽⁺⁾ cell proliferation and accumulation of IL-17 in the tumor bed, which in turn induces the mobilization of (recently described) small peritoneal macrophages (SPMs) that are enriched in IL-17 receptor A (IL-17RA) and in protumor and proangiogenic molecular mediators. Importantly, in comparison with large peritoneal macrophages (LPMs), SPMs can strongly and directly promote ovarian cancer cell proliferation. In summary, our work identifies an IL-17–dependent γδ T-cell/SPM axis that promotes tumor cell growth and thus opposes the widely accepted antitumor (and IFN-γ mediated) function of γδ T cells.