Correlation Between Planned and Executed Bone Cuts Using Robotics in Total Knee Arthroplasty: A Prospective Study of 500 Patients.

Objective: This study evaluated the precision of robotic-arm-assisted total knee arthroplasty (RATKA) in performing bone resection, predicting component size, managing soft tissue tension, and determining postoperative range of motion (ROM). Methods: A total of 500 participants were enrolled in this prospective cohort research. The procedures were conducted at a single facility, with a uniform method and implant design. The Cuvis system, a fully automated robot, was utilized for the study. The precise removal of bone at both the tibial and femur sites, the positioning of the implant, and the release of soft tissue were documented and then compared to the preoperative plan. Results: The distal (medial and lateral) femoral cuts had a mean absolute deviation from the plan of 0.23 mm, while the posterior (medial and lateral) femoral cuts had a mean absolute difference of 1 mm and 1.4 mm, respectively. The absolute discrepancies in the medial and lateral tibial cuts are 0.93 mm and - 0.06 mm, respectively. Out of 1000 bone resections, 980 (98%) were within < 1 mm from the preoperative plan. The predictions for the sizes of the tibial and femoral components had accuracies of 100% and 98.9%, respectively. Conclusion: These findings collectively underscore the effectiveness of the fully automated Cuvis robotic system in achieving consistent and accurate results in bone resections and implant sizing, highlighting its potential as a valuable tool in orthopedic surgery.

Association of urinary bisphenol A concentration with allergic asthma: results from the National Health and Nutrition Examination Survey 2005-2006.

OBJECTIVE: Bisphenol A (BPA) is being increasingly associated with adverse health effects. Our objective was to determine whether urinary BPA concentration is associated with allergic asthma in a representative US population. METHODS: Data for this analysis were obtained from the National Health and Nutrition Examination Survey 2005-2006 survey and included asthma-related questions, total immunoglobulin E (IgE), 19 allergen-specific IgE levels, and urinary environmental phenol measurements. Allergic asthma was defined as a history of asthma ever, high eosinophil count, and high total IgE or atopy. Association analyses included dichotomous and polychotomous logistic regression, receiver operating characteristic curves, Akaike information criterion, and likelihood ratio χ(2). RESULTS: We found that 10-fold increase in BPA was independently associated with a higher likelihood of allergic asthma in females [odds ratio (OR) = 2.21, p = .032] but not in males (OR = 0.83, p = .474). These findings were reaffirmed when allergic asthma was defined based on atopy rather than total IgE (OR = 2.45, p = .001 in females and OR = 0.83, p = .605 in males). Urinary BPA was significantly associated with sensitization to various specific allergens in a dose-response manner. Lastly, urinary BPA independently predicted an asthma episode in the past 12 months in females but not in males. CONCLUSIONS: Urinary BPA is significantly associated with allergic asthma in females.

Alternaria-induced release of IL-18 from damaged airway epithelial cells: an NF-κB dependent mechanism of Th2 differentiation?

BACKGROUND: A series of epidemiologic studies have identified the fungus Alternaria as a major risk factor for asthma. The airway epithelium plays a critical role in the pathogenesis of allergic asthma. These reports suggest that activated airway epithelial cells can produce cytokines such as IL-25, TSLP and IL-33 that induce Th2 phenotype. However the epithelium-derived products that mediate the pro-asthma effects of Alternaria are not well characterized. We hypothesized that exposure of the airway epithelium to Alternaria releasing cytokines that can induce Th2 differentiation. METHODOLOGY/PRINCIPAL FINDING: We used ELISA to measure human and mouse cytokines. Alternaria extract (ALT-E) induced rapid release of IL-18, but not IL-4, IL-9, IL-13, IL-25, IL-33, or TSLP from cultured normal human bronchial epithelial cells; and in the BAL fluids of naïve mice after challenge with ALT-E. Both microscopic and FACS indicated that this release was associated with necrosis of epithelial cells. ALT-E induced much greater IL-18 release compared to 19 major outdoor allergens. Culture of naïve CD4 cells with rmIL-18 induced Th2 differentiation in the absence of IL-4 and STAT6, and this effect was abrogated by disrupting NF- κB p50 or with a NEMO binding peptide inhibitor. CONCLUSION/SIGNIFICANCE: Rapid and specific release of IL-18 from Alternaria-exposed damaged airway epithelial cells can directly initiate Th2 differentiation of naïve CD4(+) T-cells via a unique NF-κB dependent pathway.

FcgammaRIIb inhibits allergic lung inflammation in a murine model of allergic asthma.

Allergic asthma is characterized by airway eosinophilia, increased mucin production and allergen-specific IgE. Fc gamma receptor IIb (FcgammaRIIb), an inhibitory IgG receptor, has recently emerged as a negative regulator of allergic diseases like anaphylaxis and allergic rhinitis. However, no studies to date have evaluated its role in allergic asthma. Our main objective was to study the role of FcgammaRIIb in allergic lung inflammation. We used a murine model of allergic airway inflammation. Inflammation was quantified by BAL inflammatory cells and airway mucin production. FcgammaRIIb expression was measured by qPCR and flow cytometry and the cytokines were quantified by ELISA. Compared to wild type animals, FcgammaRIIb deficient mice mount a vigorous allergic lung inflammation characterized by increased bronchoalveolar lavage fluid cellularity, eosinophilia and mucin content upon ragweed extract (RWE) challenge. RWE challenge in sensitized mice upregulated FcgammaRIIb in the lungs. Disruption of IFN-gamma gene abrogated this upregulation. Treatment of naïve mice with the Th1-inducing agent CpG DNA increased FcgammaRIIb expression in the lungs. Furthermore, treatment of sensitized mice with CpG DNA prior to RWE challenge induced greater upregulation of FcgammaRIIb than RWE challenge alone. These observations indicated that RWE challenge upregulated FcgammaRIIb in the lungs by IFN-gamma- and Th1-dependent mechanisms. RWE challenge upregulated FcgammaRIIb on pulmonary CD14+/MHC II+ mononuclear cells and CD11c+ cells. FcgammaRIIb deficient mice also exhibited an exaggerated RWE-specific IgE response upon sensitization when compared to wild type mice. We propose that FcgammaRIIb physiologically regulates allergic airway inflammation by two mechanisms: 1) allergen challenge mediates upregulation of FcgammaRIIb on pulmonary CD14+/MHC II+ mononuclear cells and CD11c+ cells by an IFN-gamma dependent mechanism; and 2) by attenuating the allergen specific IgE response during sensitization. Thus, stimulating FcgammaRIIb may be a therapeutic strategy in allergic airway disorders.

Allergen challenge induces Ifng dependent GTPases in the lungs as part of a Th1 transcriptome response in a murine model of allergic asthma.

According to the current paradigm, allergic airway inflammation is mediated by Th2 cytokines and pro-inflammatory chemokines. Since allergic inflammation is self-limited, we hypothesized that allergen challenge simultaneously induces anti-inflammatory genes to counter-balance the effects of Th2 cytokines and chemokines. To identify these putative anti-inflammatory genes, we compared the gene expression profile in the lungs of ragweed-sensitized mice four hours after challenge with either PBS or ragweed extract (RWE) using a micro-array platform. Consistent with our hypothesis, RWE challenge concurrently upregulated Th1-associated early target genes of the Il12/Stat4 pathway, such as p47 and p65 GTPases (Iigp, Tgtp and Gbp1), Socs1, Cxcl9, Cxcl10 and Gadd45g with the Th2 genes Il4, Il5, Ccl2 and Ccl7. These Th1-associated genes remain upregulated longer than the Th2 genes. Augmentation of the local Th1 milieu by administration of Il12 or CpG prior to RWE challenge further upregulated these Th1 genes. Abolition of the Th1 response by disrupting the Ifng gene increased allergic airway inflammation and abrogated RWE challenge-induced upregulation of GTPases, Cxcl9, Cxcl10 and Socs1, but not Gadd45g. Our data demonstrate that allergen challenge induces two sets of Th1-associated genes in the lungs: 1) Ifng-dependent genes such as p47 and p65 GTPases, Socs1, Cxcl9 and Cxcl10 and 2) Ifng-independent Th1-inducing genes like Gadd45g. We propose that allergen-induced airway inflammation is regulated by simultaneous upregulation of Th1 and Th2 genes, and that persistent unopposed upregulation of Th1 genes resolves allergic inflammation.

CS1 (CRACC, CD319) induces proliferation and autocrine cytokine expression on human B lymphocytes.

CS1 (CRACC, CD319), a member of the CD2 family of cell surface receptors, is implicated in the activation of NK cell-mediated cytotoxicity. Previous studies showed that CS1 is also expressed on activated B cells. However, the functional role of CS1 in human B-lymphocytes is not known. Two isoforms of CS1, CS1-L and CS1-S, are expressed in human NK cells that differentially regulate NK cell function. CS1-L contains immunoreceptor tyrosine-based switch motifs in its cytoplasmic domain whereas CS1-S lacks immunoreceptor tyrosine-based switch motifs. In this study, we show that human B lymphocytes express only the CS1-L isoform, and its expression is up-regulated upon B cell activation with various stimulators. Moreover, anti-CS1 mAb strongly enhanced proliferation of both freshly isolated as well as activated B cells. The enhanced proliferation effects of CS1 were most prominent on B cells activated by anti-CD40 mAbs and/or hrIL-4. The effects of CS1 on B cell proliferation were shown on both naive and memory B cells. Human cytokine microarray and quantitative real-time PCR results indicated that CS1 activation enhanced mRNA transcripts of flt3 ligand, lymphotoxin A, TNF, and IL-14. Neutralizing Abs against lymphotoxin A, TNF-alpha, and/or flt3 ligand abolished the ability of CS1 on the B cell proliferation. These results suggest that activation of B lymphocytes, through surface CS1, may be mediated through secretion of autocrine cytokines and CS1 may play a role in the regulation of B lymphocyte proliferation during immune responses.

Human natural killer cell receptor 2B4 (CD244) down-regulates its own expression by reduced promoter activity at an Ets element.

2B4 (CD244), a member of the CD2 subset of the immunoglobulin superfamily, is important for stimulating human natural killer (NK) cell cytotoxicity and cytokine production. It is expressed on all NK cells, a subpopulation of T cells, monocytes, basophils and eosinophils. 2B4 interaction with its ligand CD48 regulates NK, T and B lymphocyte functions and thus plays a central role in various immune responses. Previous study indicated a role for AP-1 and Ets in the transcription of the 2B4 gene. In this study we report that stimulation of NK cells through surface 2B4 down-regulates its own expression due to a reduction in the promoter activity at the Ets element. The down-regulation of 2B4 could be a mechanism to attenuate the co-stimulatory signal from 2B4--CD48 interactions.

Of mice and men: different functions of the murine and human 2B4 (CD244) receptor on NK cells.

2B4 was initially discovered on murine NK cells and T cells displaying non-MHC dependent cytotoxicity. Human 2B4 was cloned based on sequence homology with mouse 2B4. Recent evidence suggests that the function of this receptor might be different in the two species. Human 2B4 activates NK cell cytotoxicity and interferon gamma production when engaged by CD48, its ligand, on target cells. This activating function of human 2B4 requires recruitment of the SH2 domain containing molecule, SLAM-associated protein or SAP. In the absence of SAP in human NK cells, as occurs in immature NK cells or NK cells from X-linked lymphoproliferative disorder (XLPD) patients, human 2B4 acts as an inhibitory receptor. In contrast, in vitro and in vivo studies using 2B4-deficient mice suggest that the major function of mouse 2B4 is to inhibit murine NK cell functions when triggered by CD48 on target cells, although there are reports of activating function of murine 2B4. This inhibitory function of murine 2B4 is mediated by EAT-2, ERT and possibly other phosphatases like SHP-1 and SHIP. 2B4-SAP interaction in mouse NK cells might be a low affinity one and might not be physiologically relevant considering the inhibitory function of 2B4. This suggests that mouse and human 2B4 diverged functionally with the evolution of greater affinity between 2B4 and SAP in the human species. We speculate that evolutionary pressure from viral infections, possibly EBV, might have led to the emergence of this association and activating function of 2B4 in humans.

An Ets element regulates the transcription of the human 2B4 gene in natural killer cells.

2B4 (CD244) acts as an activation receptor on human NK cells, whereas it sends inhibitory signals in murine NK cells. A previous study indicated a prominent role for AP-1 in the transcription of 2B4 gene. To further understand the transcriptional regulation we analyzed the upstream positive regulatory region (-1151 to -704) of the 2B4 promoter. We have identified an Ets element that regulates the 2B4 gene transcription in an AP1 dependent manner.

Targeted disruption of the 2B4 gene in mice reveals an in vivo role of 2B4 (CD244) in the rejection of B16 melanoma cells.

Murine 2B4 (CD244) is a cell surface receptor expressed on all NK cells, gammadelta-T cells, a subset of CD8(+) T cells, and all CD14(+) monocytes. 2B4 binds to CD48 with high affinity, and cross-linking 2B4 with anti-2B4 Ab in vitro causes activation of NK cells. To study its physiological role, we have generated, by gene targeting, mice deficient in the expression of this cell surface molecule. The expression of lymphoid cell surface markers on PBMC and splenocytes of mice homozygous for the mutation in 2B4 (2B4(-/-)) is identical to that in wild-type mice. However, thymocytes from female 2B4(-/-) mice, but not male 2B4(-/-) mice, have an increase in the immature CD4(-)/CD8(-) population. To investigate the in vivo role of 2B4, wild-type and 2B4(-/-) mice were injected with CD48(+) and CD48(-) metastatic B16 melanoma cells. Wild-type mice rejected CD48(+) melanoma poorly compared with CD48(-) tumor cells, suggesting that ligation of 2B4 by CD48 on melanoma cells is inhibitory. In keeping with this, male 2B4(-/-) mice showed enhanced ability to reject CD48(+) melanoma cells. However, female 2B4(-/-) mice poorly rejected both CD48(+) and CD48(-) melanoma cells, revealing a gender-specific and CD48-independent defect in mice lacking 2B4. In vitro and in vivo experiments reveal a complex role of NK cells in gender specificity.

The LLT1 receptor induces IFN-gamma production by human natural killer cells.

Natural killer cell functions are regulated by signals through activating and inhibitory receptors. These receptors belong to the immunoglobulin superfamily or the lectin superfamily. We have previously identified a lectin-like transcript, LLT1, expressed in human NK cells. In the present study, we have generated a monoclonal antibody, L9.7, that specifically binds LLT1 receptor and studied the functional role of LLT1 in human NK cells. Binding of mAb L9.7 to surface LLT1 induced IFN-gamma production, but did not modulate cytotoxicity by YT cells, a human NK cell line. We further demonstrate that in resting NK cells as well as in IL-2 activated NK cells LLT1 induced IFN-gamma production, but not cytotoxicity. Excess amounts of L9.7 mAb failed to increase natural or antibody-dependent cell-mediated cytolytic activity, whereas minimal amounts achieved maximal production of IFN-gamma by YT and activated NK cells. These findings further support the separation of signaling pathways that regulate cytotoxicity and IFN-gamma production in resting as well as activated NK cells.

2B4(CD244)-mediated activation of NK cells reduces metastases of B16F10 melanoma in mice.

BACKGROUND: Natural killer (NK) cells are a third population of lymphocytes that can kill certain tumor cells. This killing is regulated by signals received through activating and inhibitory receptors. 2B4 (CD244), a member of the CD2 subset of Immunoglobulin superfamily, was identified as an activating receptor on NK cells. Interaction of 2B4 with its ligand CD48 or anti-2B4 mAb stimulates NK cell cytolytic function as well as production of INF-gamma. MATERIALS AND METHODS: A murine tumor model was used to study the in vivo role of 2B4. 2B4 and CD48 were activated in vivo by injecting anti-2B4 and anti-CD48 monoclonal antibodies. RESULTS: Activation of 2B4 or CD48 resulted in a five-fold reduction in tumor metastasis. IFN-gamma knockout mice had a two-fold increase in metastasis as compared to wild-type after 2B4 activation. CONCLUSION: Activation of 2B4 and CD48 reduces metastasis of B16F10 melanoma cells and this anti-tumor effect involves both cytolytic function and cytokine production.