Distinct tumor-infiltrating lymphocyte landscapes are associated with clinical outcomes in localized non-small-cell lung cancer.

BACKGROUND: Despite the importance of tumor-infiltrating T lymphocytes (TILs) in cancer biology, the relationship between TIL phenotypes and their prognostic relevance for localized non-small-cell lung cancer (NSCLC) has not been well established. PATIENTS AND METHODS: Fresh tumor and normal adjacent tissue was prospectively collected from 150 patients with localized NSCLC. Tissue was comprehensively characterized by high-dimensional flow cytometry of TILs integrated with immunogenomic data from multiplex immunofluorescence, T-cell receptor sequencing, exome sequencing, RNA sequencing, targeted proteomics, and clinicopathologic features. RESULTS: While neither the magnitude of TIL infiltration nor specific TIL subsets were significantly prognostic alone, the integration of high-dimensional flow cytometry data identified two major immunotypes (IM1 and IM2) that were predictive of recurrence-free survival independent of clinical characteristics. IM2 was associated with poor prognosis and characterized by the presence of proliferating TILs expressing cluster of differentiation 103, programmed cell death protein 1, T-cell immunoglobulin and mucin-domain containing protein 3, and inducible T-cell costimulator. Conversely, IM1 was associated with good prognosis and differentiated by an abundance of CD8+ T cells expressing cytolytic enzymes, CD4+ T cells lacking the expression of inhibitory receptors, and increased levels of B-cell infiltrates and tertiary lymphoid structures. While increased B-cell infiltration was associated with good prognosis, the best prognosis was observed in patients with tumors exhibiting high levels of both B cells and T cells. These findings were validated in patient tumors from The Cancer Genome Atlas. CONCLUSIONS: Our study suggests that although the number of infiltrating T cells is not associated with patient survival, the nature of the infiltrating T cells, resolved in distinct TIL immunotypes, is prognostically relevant in NSCLC and may inform therapeutic approaches to clinical care.

Analysis of trimodal and bimodal therapy in a selective-surgery paradigm for locally advanced oesophageal squamous cell carcinoma.

BACKGROUND: Long-term survival outcomes of trimodal therapy (TMT; chemoradiation plus surgery) and bimodal therapy (BMT; chemoradiation) have seldom been analysed. In a selective-surgery paradigm, the benefit of TMT in patients with a complete clinical response is controversial. Factors associated with survival in patients with a clinical complete response to chemoradiation were evaluated. METHODS: Patients with stage II-III oesophageal squamous cell carcinoma treated with TMT or BMT from 2002 to 2017 were evaluated. The BMT group consisted of patients who were otherwise eligible for surgery but underwent chemoradiation alone followed by observation. This group included patients who later had salvage oesophagectomy. Survival was evaluated and compared between TMT and BMT groups. Elastic net regularization was performed to select co-variables for Cox multivariable survival analysis in patients with a clinical complete response. RESULTS: Of 143 patients, 60 (41.9 per cent) underwent TMT and 83 (58.0 per cent) BMT. Patients who underwent TMT had longer median overall survival than those who had BMT (77 versus 33 months; P = 0.019). For patients with a clinical complete response, TMT achieved longer median overall survival than BMT (123 versus 55 months; P = 0.04). BMT had a high locoregional recurrence rate (48 versus 6 per cent; P < 0.001); 26 of 29 patients with locoregional recurrence in the BMT groupunderwent salvage resection. Cox multivariable analysis demonstrated that upper-mid oesophageal tumour location (hazard ratio (HR) 2.04; P = 0.024) and tumour length (HR 1.18; P = 0.046) were associated with worse survival. Although TMT was not associated with survival, it was a predictor of reduced recurrence (HR 0.28; P = 0.028). The maximum standardized uptake value after chemoradiation also predicted recurrence (HR 1.33; P < 0.001). CONCLUSION: In patients who achieve a clinical complete response, TMT reduces locoregional recurrence but may not prolong survival. The differences in survival outcomes may be due to patient selection; therefore, a selective-surgery strategy in oesophageal squamous cell carcinoma is a reasonable approach.

Morbidity following salvage esophagectomy for squamous cell carcinoma: the MD Anderson experience.

The survival advantage associated with the addition of surgical therapy in esophageal squamous cell carcinoma (ESCC) patients who demonstrate a complete clinical response to chemoradiotherapy is unclear, and many institutions have adopted an organ-preserving strategy of selective surgery in this population. We sought to characterize our institutional experience of salvage esophagectomy (for failure of definitive bimodality therapy) and planned esophagectomy (as a component of trimodality therapy) by retrospectively analyzing patients with ESCC of the thoracic esophagus and GEJ who underwent esophagectomy following chemoradiotherapy between 2004 and 2016. Of 76 patients who met inclusion criteria, 46.1% (35) underwent salvage esophagectomy. Major postoperative complications (major cardiovascular and pulmonary events, anastomotic leak [grade ≥ 2], and 90-day mortality) were frequent and occurred in 52.6% of the cohort (planned resection: 36.6% [15/41]; salvage esophagectomy: 71.4% [25/35]). Observed rates of 30- and 90-day mortality for the entire cohort were 7.9% (planned: 7.3% [3/41]; salvage: 8.6% [3/35]) and 13.2% (planned: 9.8% [4/41]; salvage: 17.1% [6/35]), respectively. In summary, esophagectomy following chemoradiotherapy for ESCC at our institution has been associated with frequent postoperative morbidity and considerable rates of mortality in both planned and salvage settings. Although a selective approach to surgery may permit organ preservation in many patients with ESCC, these results highlight that salvage esophagectomy for failure of definitive-intent treatment of ESCC may also constitute a difficult clinical undertaking in some cases.

Lessons from aviation - the role of checklists in minimally invasive cardiac surgery.

We describe an adverse event during minimally invasive cardiac surgery that resulted in a multi-disciplinary review of intra-operative errors and the creation of a procedural checklist. This checklist aims to prevent errors of omission and communication failures that result in increased morbidity and mortality. We discuss the application of the aviation - led "threats and errors model" to medical practice and the role of checklists and other strategies aimed at reducing medical errors.

Maternal vitamin D and E intakes during early pregnancy are associated with airway epithelial cell responses in neonates.

BACKGROUND: Antenatal factors including maternal diet may predispose to airway disease, possibly by impacting on fetal airway development. OBJECTIVE: This cohort study tested the hypothesis that maternal vitamin D and E status in early pregnancy is associated with airway epithelial cell (AEC) responses in new born infants and examined constitutive and TNFα/IL-1ß, house dust mite (HDM) extract or lipopolysaccharide (LPS)-stimulated neonatal AEC responses in vitro. METHODS: Maternal dietary vitamin D and E intakes (plasma 25[OH]D3 or α-tocopherol) were characterized at 10-12 weeks gestation. Neonatal nasal AECs were collected soon after birth and cultured to tertiary passage. Constitutive and stimulated - TNFα/IL-1ß, HDM extract or LPS - secretory responses (VEGF, RANTES, MCP-1, IL-17A, IFN-γ, GM-CSF, eotaxin, MIP1-α, MIP1-ß, ICAM, IL-6, IL-8, IL-10, TNF) in 139 AEC cultures were quantified. RESULTS: AEC mediator release was greater following TNF-α/IL-1ß, HDM or LPS stimulation compared to constitutive release. Increased maternal dietary vitamin D was associated with significant increases in IL-10 release by AEC after stimulation with TNF-α/IL-1ß (P = 0.024) or HDM (P = 0.049). Maternal plasma α-tocopherol at 10-12 weeks gestation was positively associated with MIP1α (Spearman's rho 0.242, P = 0.009) and IL-3 (ρ 0.189, P = 0.043) responses after TNF-α/IL-1ß stimulation and negatively associated with TNF (ρ -0.404, P = 0.011) and MIP1ß (ρ -0.322, P = 0.046) responses after LPS stimulation. DISCUSSION: Neonatal AECs respond to pro-inflammatory and allergenic stimuli in vitro demonstrating their potential to function as components of the innate immune response. Our findings suggest that associations exist between maternal micronutrient intake during early pregnancy and aspects of stimulated neonatal airway epithelial cell secretory function that may in turn impact on the development of asthma and/or allergic rhinitis in later life.

Meta-analysis of suicide rates among psychiatric in-patients.

OBJECTIVE: To examine factors associated with the number of psychiatric admissions per in-patient suicide and the suicide rate per 100,000 in-patient years in psychiatric hospitals. METHOD: Random-effects meta-analysis was used to calculate pooled estimates, and meta-regression was used to examine between-sample heterogeneity. RESULTS: Forty-four studies published between 1945 and 2013 reported a total of 7552 in-patient suicides. The pooled estimate of the number of admissions per suicide calculated using 39 studies reporting 150 independent samples was 676 (95% CI: 604-755). Recent studies tended to report higher numbers of admissions per suicide than earlier studies. The pooled estimate of suicide rates per 100,000 in-patient years calculated using 27 studies reporting 95 independent samples was 147 (95% CI: 138-156). Rates of suicide per 100,000 in-patient years tended to be higher in more recent samples, in samples from regions with a higher whole of population suicide rate, in samples from settings with a shorter average length of hospital stay and in studies using coronial records to define suicide. CONCLUSION: Rates of in-patient suicide in psychiatric hospitals vary remarkably and are disturbingly high. Further research might clarify the extent to which patient factors and the characteristics of in-patient facilities contribute to the unacceptable mortality in psychiatric hospitals.

Goserelin with chemotherapy to preserve ovarian function in pre-menopausal women with early breast cancer: menstruation and pregnancy outcomes.

BACKGROUND: Premature ovarian failure and infertility following chemotherapy in early breast cancer (EBC) are major concerns for young women. The role of gonadotrophin-releasing hormone (GnRH) agonists with chemotherapy in EBC in reducing the incidence of chemotherapy-induced early menopause remains uncertain, and long-term data on the recovery of fertility are sparse. We report an audit of our experience with the GnRH agonist, goserelin (Zoladex®), used with chemotherapy to preserve ovarian function and maintain fertility. PATIENTS AND METHODS: Pre-menopausal women were given goserelin subcutaneously every 28 days during chemotherapy, starting 0-14 days before treatment. The main clinical end point was recovery of menstruation after chemotherapy. The other end points were rate of successful conception and median time to recovery of menses. RESULTS: About 84% of 125 women recovered menstruation with the median time to recovery of 6 months (1-43 months), including 76% of 71 patients aged over 35. Of the 42 patients who attempted pregnancy, 71% (n=30) managed to achieve pregnancies. At the time of analysis, there were 42 pregnancies and 30 healthy deliveries. CONCLUSIONS: The GnRH agonist, goserelin, given with chemotherapy for EBC is associated with a low risk of long-term chemotherapy-induced amenorrhoea and a high chance of pregnancy. Further randomised trials are needed.

A phase II randomized trial of induction chemotherapy versus no induction chemotherapy followed by preoperative chemoradiation in patients with esophageal cancer.

BACKGROUND: The contribution of induction chemotherapy (IC) before preoperative chemoradiation for esophageal cancer (EC) is not known. We hypothesized that IC would increase the rate of pathologic complete response (pathCR). METHODS: Trimodality-eligibile patients were randomized to receive no IC (Arm A) or IC (oxaliplatin/FU; Arm B) before oxaliplatin/FU/radiation. Surgery was attempted ∼5-6 weeks after chemoradiation. The pathCR rate, post-surgery 30-day mortality, overall survival (OS), and toxic effects were assessed. Bayesian methods and Fisher's exact test were used. RESULTS: One hundred twenty-six patients were randomized dynamically to balance the two arms for histology, baseline stage, gender, race, and age. Fifty-five patients in Arm A and 54 in Arm B underwent surgery. The median actuarial OS for all patients (54 deaths) was 45.62 months [95% confidence interval (CI), 27.63-NA], with median OS 45.62 months (95% CI 25.56-NA) in Arm A and 43.68 months (95% CI 27.63-NA) in Arm B (P = 0.69). The pathCR rate in Arm A was 13% (7 of 55) and 26% (14 of 54) in Arm B (two-sided Fisher's exact test, P = 0.094). Safety was similar in both arms. CONCLUSIONS: These data suggest that IC produces non-significant increase in the pathCR rate and does not prolong OS. Further development of IC before chemoradiation may not be beneficial. Clinical trial no.: NCT 00525915 (www.clinicaltrials.gov).

Photonic-plasmonic-coupled nanoantennas for polarization-controlled multispectral nanofocusing.

We report on the design and experimental demonstration of array-enhanced nanoantennas for polarization-controlled multispectral nanofocusing in the near-IR spectral range. We design plasmonic double bow-tie nanoantennas-coupled to multiple-periodic nanoparticle arrays to harvest radiation of designed wavelengths from a large spatial area and to focus it into a targeted nanoscale region. Near-field calculations were performed on a gold nanoantenna array using three-dimensional finite difference time domain simulations. Cross-shaped optical nanoantennas were fabricated on glass substrates using electron beam lithography. The optical characterization of the fabricated nanoantennas was performed using second harmonic excitation spectroscopy that demonstrates multiwavelength photonic coupling in good agreement with the antenna modeling. The nanoantenna structures introduced in this Letter provide the ability to focus optical energy into deep subwavelength areas and to address multiple spectral regions with polarization control. Such attributes are highly desirable in optical biosensing, enhanced Raman scattering, and for nonlinear plasmonic applications.

Application of molecular epidemiology to understanding campylobacteriosis in the Canterbury region of New Zealand.

Pulsed-field gel electrophoresis genotypes of Campylobacter isolates from 603 human patients were compared with 485 isolates from retail offal (primarily chicken and lamb) to identify temporal clusters and possible sources of campylobacteriosis. Detailed epidemiological information was collected from 364 of the patients, and when combined with genotyping data allowed a putative transmission pathway of campylobacteriosis to be assigned for 88% of patients. The sources of infection were 47% food, 28% direct animal contact, 7% overseas travel, 4% person-to-person transmission and 3% water-related. A significant summer increase in campylobacteriosis cases was primarily attributed to an increase in food-related cases. Genotyping of isolates was essential for identifying the likely cause of infection for individuals. However, a more rapid and cheaper typing tool for Campylobacter is needed, which if applied to human and animal isolates on a routine basis could advance greatly our understanding of the ongoing problem of Campylobacter infection in New Zealand.

The Economic Impact of a Pilot Digital Day-Case Pathway for Knee Arthroplasty in a U.K. Setting.

Knee replacements are an increasingly common procedure in the U.K. National Health Service (NHS). Importantly, the pathway for such procedures represents a prime opportunity to leverage digital technology, modernize and streamline the approach to care, and free up resources. Methods: In this 21-patient pilot study, we assessed the impact of implementing a digital day-case pathway for knee replacement surgery at the Calderdale and Huddersfield NHS Foundation trust. Results: Fourteen (67%) of the 21 eligible patients were treated as day cases, with an average length of stay of 8.8 hours. The pilot data were utilized to model the potential impact of implementing a digital day-case program more widely across the trust. This model showed increased efficiency over the entire episode of care, with reductions in physiotherapy appointments, preoperative visits, hospital days, and face-to-face consultations. Not only would these improvements free up capacity, but they would also result in an estimated saving of £240,540 to the trust while reducing the CO2 footprint of knee replacements by 119,381 kg CO2 emitted. A sensitivity analysis revealed that, even with substantial variation of several key variables within the pathway, a trust-wide digital day-case program would still be a cost-saving measure. Conclusions: Overall, the present study supports the growing notion that digital technology can facilitate the transformation of care pathways, resulting in greater efficiency and financial savings for health-care providers while reducing the time patients spend in the hospital. Level of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Exploring the Impact and Acceptance of Wearable Sensor Technology for Pre- and Postoperative Rehabilitation in Knee Replacement Patients: A U.K.-Based Pilot Study.

Knee replacement operations are common, highly successful procedures that are increasing in frequency. The COVID-19 pandemic has emphasized the need for innovative care pathways that reduce face-to-face appointments. We report on the impact of introducing a wearable sensor for pre- and postoperative rehabilitation of 21 knee replacement patients at 2 hospitals in the U.K. Methods: The sensor (BPMpathway; 270 Vision) was provided during joint school prior to knee replacement and stayed with the patient until a maximum of 9 weeks post-surgery. Participant progress and exercise were monitored remotely, with exercise regimens altered as required. Participants and clinicians could communicate remotely via the device. Results: The median range of motion during the first week post-surgery was 63° (interquartile range [IQR] = 21°) and increased to 136° (IQR = 16°) by week 7. The rate of participant compliance with exercises using the device was 32.3% for thrice-daily compliance and 52.4% for once-daily compliance. The 2-way communication channel was well utilized by both participants and clinicians. We report a 35.7% reduction in face-to-face physiotherapy appointments compared with standard practice. Finally, >80% of users who completed the feedback questionnaire reported a positive experience using the device, finding it easy to understand and reporting that it motivated them to perform their exercises. Conclusions: The use of BPMpathway was well received, effective, and reduced face-to-face physiotherapy appointments. Clinical Relevance: Remote monitoring can reduce the burden to the outpatient physiotherapy service by supporting the post-COVID-19 surgical service recovery plans of the National Health Service and allowing patients to recuperate at home.

The Philippine cynomolgus monkey (Macaca fasicularis) provides a new nonhuman primate model of tuberculosis that resembles human disease.

A nonhuman primate model of tuberculosis that closely resembles human disease is urgently needed. We have evaluated the Philippine cynomolgus monkey, Macaca fasicularis, as a model of TB. Cynomolgus monkeys challenged intratracheally with extremely high doses of Mycobacterium tuberculosis (10(5) or 10(4) CFU) developed an acute, rapidly progressive, highly fatal multilobar pneumonia. However, monkeys challenged with moderate or low doses of M. tuberculosis (

Retrovirus-mediated wild-type p53 gene transfer to tumors of patients with lung cancer.

A retroviral vector containing the wild-type p53 gene under control of a beta-actin promoter was produced to mediate transfer of wild-type p53 into human non-small cell lung cancers by direct injection. Nine patients whose conventional treatments failed were entered into the study. No clinically significant vector-related toxic effects were noted up to five months after treatment. In situ hybridization and DNA polymerase chain reaction showed vector-p53 sequences in posttreatment biopsies. Apoptosis (programmed cell death) was more frequent in posttreatment biopsies than in pretreatment biopsies. Tumor regression was noted in three patients, and tumor growth stabilized in three other patients.

Minimally invasive esophagectomy versus open esophagectomy, a symptom assessment study.

Minimally invasive esophagectomy (MIE) is used with hope to decrease the morbidity associated with an open esophagectomy. Reflux and dumping syndromes are the most important functional complaints in patients after esophagectomy. This study compares the functional benefits of MIE with open esophagectomy. The study enrolled patients who underwent either minimally invasive or open esophagectomy for cancer between 2004 and 2009. No patients in the MIE group had a pyloroplasty or myotomy. Each patient in the MIE group was paired to a patient in the open esophagectomy group via propensity matching. Matching variables included age, race, gender, preoperative treatment, history of prior cancer, American Society of Anesthesiologists Risk Scale, performance status, clinical stage, body mass index, histology, level of anastomosis, and time elapsed since surgery. The patients were asked to answer 26 questions about their reflux and dumping using validated questionnaires. A total of 181 patients were included in the study. From this group, 44 pairs of patients were created and used for the analysis. The median follow-up was 12.1 months for the MIE group and 18.3 months for the open group. The reflux score was slightly worse in the MIE group (5.5 versus 3.5, P= 0.021). There was no difference in the dumping symptoms between the two groups. The most common complaints seen in the dumping questionnaire in almost one-third of all patients were early satiety, abdominal discomfort, nausea, and diarrhea. Of the patients, 77% were satisfied or very satisfied with their condition in the MIE group compared with 93% in the open group (P= 0.287). Reflux, dumping, and overall satisfaction after MIE without pyloroplasty are comparable with those obtained after open esophagectomy with a pyloric drainage procedure.

Different depth intermittent sand filters for laboratory treatment of synthetic wastewater with concentrations close to measured septic tank effluent.

The objective of this study was to apply hydraulic and chemical oxygen demand (COD) loading rates at the upper limits of the design criteria for buried sand filters to test the sand filter depth design criteria. Over a 274-day study duration, synthetic effluent with a strength of domestic wastewater was intermittently dosed onto two sand filters of 0.2 m diameter, with depths of 0.3 and 0.4 m. Hydraulic and organic carbon loading rates of 105 L m(-2) d(-1) and 40 g COD m(-2) d(-1), respectively, were applied to the filters. The filters did not clog and had good effluent removal capabilities for 274 and 190 days, respectively. However, the 0.3 m-deep filter did experience a reduced performance towards the end of the study period. In the 0.3 and 0.4 m-deep filters, the effluent COD and SS concentrations were less than 86 and 31 mg L(-1), respectively, and nitrification was nearly complete in both these columns. Ortho-phosphorus (PO(4)-P) removal in fine sand and laterite 'upflow' filters, receiving effluent from the 0.3 m-deep filter, was 10% and 44%, respectively.

Evaluating the use of gradient echo imaging for the detection of cerebral microbleeds in acute stroke cases: A retrospective data analysis in a UK stroke unit.

INTRODUCTION: Imaging in stroke, allows its classification into ischaemic stroke (IS) or intracranial haemorrhagic stroke (ICH), ensuring time-sensitive treatment to be administered. Imaging can also allow detection of cerebral microbleeds (CMBs), which may further determine pharmacological intervention in acute stroke. True gradient echo (T2∗GRE) or susceptibility weighted imaging (SWI) have high sensitivity for the detection of CMBs. These two sequences are included in the national guidelines; however, the implementation of these guidelines can vary depending on local interpretation and scanner capabilities. AIM: To explore the use and application of blood sensitive MRI sequences in a specialist UK stroke unit for the detection of CMBs, to improve local practice. METHODS: A retrospective data analysis of the native database, spanning a 6-month period, was used. The data of 281 acute stroke patients with an MRI were reviewed and analysed. The MRI sequences applied, and the final diagnosis were noted for each case. RESULTS: Of the 281 acute stroke patients with MRI, 259 (92.1%) had an IS, 16 (5.68%) an ICH and 6 (2.14%) had both. Overall, 13 (4.63%) had a CMB diagnosis. All of these 13 patients had a true T2∗GRE sequence. CMBs were not detected in the absence of a T2∗GRE sequence. CONCLUSION: T2∗GRE imaging is essential for detecting CMBs. When omitted, CMB incidence can be considerably lower than that suggested in the literature. Missing CMB diagnoses in stroke patients may result in suboptimal treatment pathways, compromising the patients' standard of care. IMPLICATIONS FOR PRACTICE: When SWI is not available, it is imperative to always include a true T2∗GRE sequence to detect microbleeds in suspected acute stroke cases.

Adhesion to fibronectin prolongs eosinophil survival.

We have investigated the effect of adhesion to fibronectin (Fn) on the survival of eosinophils in culture. Peripheral blood eosinophils from normal human donors were separated by immunomagnetic selection and cultured in RPMI on Fn- (100 micrograms/ml) coated microtiter plates for up to 96 h. Survival was measured by trypan blue exclusion. There was a significant enhancement of eosinophil survival with Fn as compared with both bovine serum albumin-coated and uncoated wells (p < 0.05-0.01). Fn-induced eosinophil survival was comparable to that obtained with exogenous interleukin 3 (IL-3) or granulocyte/macrophage colony-stimulating factor (GM-CSF) and was inhibitable by antibodies against Fn, very late antigen 4 (VLA-4), IL-3, and GM-CSF. Supernatants from Fn-, but not BSA-coated wells contained picogram amounts of IL-3 and GM-CSF, and eosinophils cultured on Fn for 24 h expressed mRNA for GM-CSF as determined by in situ hybridization. Therefore, Fn prolongs eosinophil survival in culture by triggering autocrine generation of cytokines by eosinophils. Since neutrophils lack VLA-4, this could provide a partial explanation for the preferential accumulation of eosinophils at sites of allergic inflammation, as well as the predominant tissue localization of eosinophils in healthy individuals.

Eosinophil adhesion to nasal polyp endothelium is P-selectin-dependent.

Tissue eosinophilia is a characteristic feature of a number of inflammatory diseases including asthma and nasal polyposis. Eosinophil migration into tissues is controlled in part by interactions between eosinophil adhesion receptors and counter-structures on the vascular endothelium. To determine the receptors used by eosinophils to adhere to vascular endothelium in allergic inflammation we have adapted the Stamper-Woodruff frozen section assay (FSA) to study eosinophil adhesion to nasal polyp endothelium. Immunohistology indicated that intercellular adhesion molecule 1 (ICAM-1), E-selectin and P-selectin were well expressed by nasal polyp endothelium, whereas expression of vascular cell adhesion molecule 1 (VCAM-1) was weak or absent. Unstimulated human peripheral blood eosinophils adhered specifically to nasal polyp endothelium. Adherence was temperature and divalent cation-dependent and saturable at cell densities > 5 x 10(6) cells/ml. Eosinophil adhesion was almost completely inhibited by a monoclonal antibody (mAb) against P-selectin and by a chimeric molecule consisting of the Fc portion of human IgG and the lectin binding domain of P-selectin, which binds to the P-selectin ligand on leucocytes. Anti-Mac-1 mAb partially inhibited eosinophil adhesion whereas mAb against E-selectin, L-selectin, ICAM-1, VCAM-1, very late activation antigen 4, and lymphocyte function-associated antigen 1 had no effect. P-selectin is stored in intracellular granules within the endothelial cell and in vitro is only transiently expressed. To determine if P-selectin was expressed on the membrane of the nasal polyp endothelium we compared P-selectin expression in normal skin and nasal polyps after acetone fixation, which permeabilizes cells, and paraformaldehyde, which only allows staining of membrane expressed receptors. In the skin, good expression was seen with acetone fixation but no expression was seen after paraformaldehyde treatment, whereas in nasal polyps, similar expression was observed with both fixatives. In addition immunofluorescence with confocal microscopy demonstrated lumenal staining of nasal polyp endothelium indicating that P-selectin was located on the surface of endothelial cells while in skin only an intracellular granular distribution was apparent. Lastly, whereas eosinophils bound consistently to nasal polyp endothelium, no binding was observed to blood vessels in normal skin further supporting the idea that eosinophils were binding to membrane expressed and not intracellular P-selectin. The importance of P-selectin in eosinophil adhesion to nasal polyp endothelium suggests that P-selectin antagonists may be effective at inhibiting eosinophil accumulation at sites of allergic inflammation.