P-selectin glycoprotein ligand-1 (PSGL-1) is a ligand for L-selectin in neutrophil aggregation

In inflammation, activated neutrophils adhere to endothelial cells and aggregate with one another. While beta 2-integrin and L-selectin are essential for aggregation, their ligands remain to be identified. We have previously shown that L-selectin mediates a carbohydrate-dependent interaction in aggregation (Simon et al: J Immunol 149:2765, 1992; Rochon et al: J Immunol 152:1385, 1994). We have suggested that the L- selectin counter-structure is a mucinlike protein and proposed that aggregation occurs through a two-step process involving L-selectin, beta 2-integrin, and their distinct counter-structures (Bennett et al: J Leuk Biol 58:510, 1995). A candidate ligand for L-selectin is P- selectin glycoprotein ligand-1 (PSGL-1), a mucinlike protein on neutrophils that binds P-and E-selectin. Using flow cytometry we show that the number and size of neutrophil aggregates is reduced with Fab fragments of PL1, an anti-PSGL-1 monoclonal antibody that blocks the interaction between P-selectin and PSGL-1 (Moore et al: J Cell Biol 128:661, 1995). In addition, monoclonal antibodies to L-selectin and PSGL-1 were used simultaneously to modulate the availability of these adhesion molecules on individual cell populations. The inhibition of aggregation by these antibodies is consistent with L-selectin and PSGL- 1 being counter-structures. We suggest that L-selectin and PSGL-1 support a collisional cell-cell interaction that represents the first step in neutrophil aggregation.     

Immunochemical characterization of fibrinogen, fibrin I, and fibrin II in human thrombi and atherosclerotic lesions

Arterial thrombi and atherosclerotic lesions were analyzed immunochemically and examined histologically. The extent of in vivo proteolytic cleavage of the amino-terminal end of fibrinogen by thrombin and plasmin was determined and quantitated by specific radioimmunoassays. The samples were treated with cyanogen bromide (CNBr), and the total amount of fibrinogen and fibrin-derived protein was determined as NDSK, the NH2-terminal disulfide knot of fibrinogen. Thrombin-releasable fibrinopeptides A and B were used to quantitate fibrinogen and fibrin I. Previous plasmin cleavage of the B beta chain was inferred from the amount of B beta 1-42 and B beta 15-42 in undigested NDSK. The results obtained in both acute and organized thrombi indicate that approximately 60% of the total protein (as determined by amino acid analysis) was fibrinogen-derived and that 70% to 80% of the fibrinogen-derived material was fibrin II. These findings support the hypothesis that fibrin II as distinct from fibrin I is the predominant component in a thrombus. In samples from normal and atherosclerotic aortas, fibrinogen-derived protein comprised less than 10% of the total protein. Samples from grossly normal aortas contained only fibrinogen and fibrin I. Fibrinogen concentration decreased and fibrin II concentration increased with increasing severity of the lesions, suggesting that increased fibrin II formation is associated with progression of atheromas.     

Knowledge, attitudes and commitment toward organ donation among nursing students in Hong Kong

Background

Organ donation is the major component for transplant programs; however, the rate of organ donation is relatively low in Asia. Therefore, understanding the attitude and knowledge of individuals that affect their willingness to commit as an organ donor is crucial to develop effective educational programs that raise public awareness and commitment toward organ donation. The current study aims to identify the knowledge level, attitude, and commitment toward organ donation among nursing students in a local university.

Methods

A questionnaire was developed and distributed to all full-time nursing students of undergraduate and master programs in a university at Hong Kong.

Results

A total of 362 students completed the questionnaire, including 87 males and 257 females. The mean age of the students was 22.6 years. A total of 147 students (40.6%) had registered for organ donation. Students on average could correctly answer 23.7 out of 33 questions (71.8%) regarding their knowledge on organ donation and transplantation. With regard to attitude toward organ donation, students obtained a mean score of 70.2. Univariate analysis revealed that year of study, religion, and attitude were significantly associated with commitment toward organ donation. In logistic regression analysis, year of study (odds ratio [OR] for year 2, 1.961, 95% confidence interval [CI], 1.006-3.824; OR for year 3, 6.915, 95% CI, 2.835-16.868; and OR for year 4, 4.845, 95% CI, 2.071-11.334) and attitude (OR, 1.087, 95% CI, 1.049-1.126) were significantly associated with commitment toward donation after adjusting the age, gender, and study program.

Conclusion

Attitude and year of study were strongly correlated with commitment toward organ donation; therefore, educational or promotional materials should be provided to improve the attitude of students toward organ donation.     

Transoral robotic supracricoid partial laryngectomy with cartilaginous framework preservation

To report the technical feasibility of performing transoral robotic supracricoid partial laryngectomy with preservation of the thyroid cartilage. This is a case report from a tertiary-care academic institution. A patient with recurrent T2 glottic squamous cell carcinoma of the larynx underwent supracricoid partial laryngectomy with negative margins and preservation of the laryngeal framework using transoral robotic surgery, where an adequate exposure to the endolarynx was obtained by using a Feyh-Kastenbauer retractor. The patient was successfully decannulated in postoperative week 4, and his gastrostomy tube was removed in postoperative week 6. Transoral robotic surgery may be feasible in select glottic/subglottic laryngeal lesions, if adequate exposure is obtained.     

p53 negatively regulates the osteogenic differentiation of vascular smooth muscle cells in mice with chronic kidney disease

Aim

To investigate the osteogenic differentiation of vascular smooth muscle cells (VSMCs) in mice with chronic kidney disease (CKD) and to evaluate the effects of p53 on the osteogenic differentiation of the VSMCs.

Methods

Experimental models of CKD-associated vascular calcification generated by five-sixth (5/6) nephrectomy (Nx) and a high-phosphate (HP) diet were used in p53+/+ and p53–/– mice. Following 5/6 Nx, aortic calcification, markers of osteogenic differentiation, VSMCs and p53 protein in aortic tissues were studied.

Results

Aortic calcification was observed after eight weeks following 5/6 Nx in mice of both genotypes, and expression of the markers of osteogenic differentiation in the VSMCs was increased. These changes were continuously observed up to 12 weeks after 5/6 Nx, and particularly after 5/6 Nx + HP. Compared with p53+/+ mice, aortic calcification in p53–/– mice was more severe (p < 0.001). Expression of the markers of osteogenic differentiation was noticeably increased (p < 0.001), while expression of the marker of VSMCs had decreased (p < 0.001). Statistical analysis demonstrated that the markers of osteogenic differentiation were negatively correlated with p53, and the marker of VSMCs was positively correlated with p53 (p < 0.001).

Conclusion

p53 has the potential to negatively regulate the osteogenic differentiation of VSMCs in CKD mice.     

Optimal Lymph Node Examination and Adjuvant Chemotherapy for Stage I Lung Cancer

ObjectiveTo determine the optimal number of lymph nodes (LNs) examined and the role of adjuvant chemotherapy in stage I lung cancer.MethodsThe National Cancer Database was queried for surgically treated patients with pathologic stage I lung cancer between 2006 and 2014 (N = 65,438). The optimal LN numbers were determined in the multivariate Cox model and were further validated in the cohort with clinical stage I disease (N = 117,112) in terms of nodal upstaging and prognostic stratification. The role of adjuvant chemotherapy in patients with suboptimal staging (number of LNs examined was less than than the optimum) was evaluated in each T stage.ResultsThe number of LNs examined correlated with tumor size (p < 0.001). There were increasing survival benefits with each additional LN examined—up to eight, nine, 10, and 11 nodes for patients with T1a, T1b, T1c, and T2a, respectively. Validation from the cohort with clinically staged disease showed that the threshold of eight to 11 LNs was an independent predictor of nodal upstaging (OR = 1.706, 95% confidence interval [CI] 1.608–1.779) and survival outcome (hazard ratio = 0.890, 95% CI: 0.865–0.916). After propensity matching, adjuvant chemotherapy was associated with improved survival in patients with stage T2a disease having suboptimal staging (hazard ratio = 0.841, 95% CI: 0.714–0.990), but not in patients with stage T1a to T1c disease.ConclusionLN evaluation was important for accurate staging and adequate treatment, and examinations of an increasing number of nodes for progressively higher T components (i.e., eight, nine, 10, and 11 nodes for T1a, T1b, T1c, and T2a tumors, respectively) seemed crucial to predict upstaging and survival outcomes. Adjuvant chemotherapy might be beneficial to patients with stage T2a disease who have suboptimal nodal staging.     

Treatment of murine lupus using nucleosomal T cell epitopes identified by bone marrow–derived dendritic cells

Objective

Systemic lupus erythematosus (SLE) is characterized by the existence of a heterogeneous group of autoantibodies directed against intact nuclear structures, such as nucleosomes. The most prominent of these autoantibodies are those directed against double‐stranded DNA (dsDNA) and histones. The majority are of the IgG isotype and show affinity maturation, both of which are known hallmarks of T cell help. Much evidence suggests that the nucleosome is a major candidate autoantigen in SLE. In this study, a novel strategy was used to identify the critical CD4+ T cell autoepitopes in nucleosomes. In addition, peptide‐based therapy was then performed in a lupus animal model.

Methods

Bone marrow (BM)–derived dendritic cells (DCs) were used to examine the self–T cell responses against nucleosomes and to characterize the T cell epitope(s) of nucleosomes in (NZB × NZW)F₁ (BWF₁) mice.

Results

Several potential auto–T cell epitopes of core histone proteins (H2A, H2B, H3, and H4) were identified. Nucleosome‐pulsed BM‐derived DCs elicited release of interleukin‐4 and interferon‐γ, representing a Th0 (i.e., mixed Th1 and Th2) pattern of cytokine production. In addition, intradermal immunization of BWF₁ mice with the H3^111–130 peptide not only suppressed the level of anti‐dsDNA and anti–single‐stranded DNA IgG, but also significantly delayed the progress of glomerulonephritis in lupus‐prone BWF₁ mice.

Conclusion

These results will help in understanding how pathogenic autoimmune responses develop in spontaneous SLE. This may potentially open the way to T cell–based immunotherapy for lupus.