NCCT Markers of Intracerebral Hemorrhage Expansion Using Revised Criteria: An External Validation of Their Predictive Accuracy.

BACKGROUND AND PURPOSE: Several NCCT expansion markers have been proposed to improve the prediction of hematoma expansion. We retrospectively evaluated the predictive accuracy of 9 expansion markers. MATERIALS AND METHODS: Patients admitted for intracerebral hemorrhage within 24 hours of last seen well were retrospectively included from April 2016 to April 2020. The primary outcome was revised hematoma expansion, defined as any of a ≥6-mL or ≥33% increase in intracerebral hemorrhage volume, a ≥ 1-mL increase in intraventricular hemorrhage volume, or de novo intraventricular hemorrhage. We assessed the predictive accuracy of expansion markers and determined their association with revised hematoma expansion. RESULTS: We included 124 patients, of whom 51 (41%) developed revised hematoma expansion. The sensitivity of each marker for the prediction of revised hematoma expansion ranged from 4% to 78%; the specificity, 37%-97%; the positive likelihood ratio, 0.41-7.16; and the negative likelihood ratio, 0.49-1.06. By means of univariable logistic regressions, 5 markers were significantly associated with revised hematoma expansion: black hole (OR = 8.66; 95% CI, 2.15-58.14; P = .007), hypodensity (OR = 3.18; 95% CI, 1.49-6.93; P = .003), blend (OR = 2.90; 95% CI, 1.08-8.38; P = .04), satellite (OR = 2.84; 95% CI, 1.29-6.61; P = .01), and Barras shape (OR = 2.41, 95% CI; 1.17-5.10; P = .02). In multivariable models, only the black hole marker remained independently associated with revised hematoma expansion (adjusted OR = 5.62; 95% CI, 1.23-40.23; P = .03). CONCLUSIONS: No single NCCT expansion marker had both high sensitivity and specificity for the prediction of revised hematoma expansion. Improved image-based analysis is needed to tackle limitations associated with current NCCT-based expansion markers.

Successful Reperfusion is Associated with Favorable Functional Outcome despite Vessel Perforation during Thrombectomy: A Case Series and Systematic Review.

BACKGROUND: Arterial perforation is a potentially serious complication during endovascular thrombectomy. PURPOSE: Our aim was to describe interventional approaches after arterial perforation during endovascular thrombectomy and to determine whether reperfusion remains associated with favorable outcome despite this complication. DATA SOURCES: Data from consecutive patients with acute stroke undergoing endovascular thrombectomy were retrospectively collected between 2015 to 2020 from a single-center cohort, and a systematic review was performed using PubMed, EMBASE, and Ovid MEDLINE up to June 2020. STUDY SELECTION: Articles reporting functional outcome after arterial perforation during endovascular thrombectomy were selected. DATA ANALYSIS: Functional outcomes of patients achieving successful reperfusion (TICI 2b/3) were compared with outcomes of those with unsuccessful reperfusion in our single-center cohort. We then summarized the literature review to describe interventional approaches and outcomes after arterial perforation during endovascular thrombectomy. DATA SYNTHESIS: In our single-center cohort, 1419 patients underwent endovascular thrombectomy, among whom 32 (2.3%) had vessel perforation and were included in the analysis. The most common hemostatic strategy was watchful waiting (71% of cases). Patients with successful reperfusion had a higher proportion of favorable 90-day mRS scores (60% versus 12.5%; P = .006) and a lower mortality rate (13.3% versus 56.3%, P = .01) than patients without successful reperfusion. Thirteen articles were included in the systematic review. Successful reperfusion also appeared to be associated with better outcomes. LIMITATIONS: Given the low number of published reports, we performed only a descriptive analysis. CONCLUSIONS: Arterial perforation during endovascular thrombectomy is rare but is associated with high mortality rates and poor outcome. However, successful reperfusion remains correlated with favorable outcome in these patients.

Workplace violence among healthcare workers, a multicenter study in Italy.

OBJECTIVES: The purpose of this study is to assess the prevalence and determinants of workplace violence and the sociodemographic risk factors associated. STUDY DESIGN: This was a multicenter cross-sectional study. METHODS: The study was performed using self-compiled Italian version of the World Health Organization's questionnaire on workplace violence online by filling in a Google form. The survey was opened from May 2018 to March 2020 and lasted 5-10 min. RESULTS: The sample consists of 3659 healthcare workers, of which 2525 (69%) are females, 1446 (39.5%) are nurses, and 2029 (55.5%) are health workers from northern Italy. The most frequent age group of the sample is 50-54 years (16.7%). A total of 366 (10%) healthcare workers are victims of physical aggression at work in the last 12 months, of which 6.3% with a weapon. The risk of being a victim of physical aggression at work in the last 12 months is significantly associated with the following independent variables: male gender (odds ratio [OR] 1.72, 95% confidence interval [CI]: 1.36-2.17), work in southern Italy (OR 1.59, 95% CI: 1.10-2.28), and being a nurse (OR 2.56, 95% CI: 2.01-3.25). The risk of being a victim of physical aggression at work with a weapon in the last 12 months is significantly associated with work in southern Italy (OR 9.33, 95% CI: 3.83-22.73). A total of 1723 (47.1%) of healthcare workers declare to be a victim of verbal aggression at work in the last 12 months. The risk of being a victim of verbal aggression at work in the last 12 months is significantly associated with the following independent variables: work in northern Italy (adjusted OR [aOR] 1.54, 95% CI: 1.32-1.81), work in southern Italy (aOR 3.68, 95% CI: 2.90-4.68), and be more than 55 years old (aOR 0.73, 95% CI: 0.63-0.85). CONCLUSIONS: The study underlines that the problem of verbal and physical aggression against healthcare workers is still central and is a further starting point for research. The prevalence of violence is difficult to assess because violent incidents are underreported or unreported. The results of the study suggest that increased awareness is needed to develop effective control strategies at the individual, hospital, and national levels to prevent aggression and improve the conditions of victims.

Exophthalmos following mechanical thrombectomy for anterior circulation stroke: A retrospective study and review of literature.

BACKGROUND: Anecdotal cases of exophthalmos after acute mechanical thrombectomy have been described. We sought to estimate the incidence in a large cohort of patients with acute anterior circulation stroke treated with mechanical thrombectomy. Secondarily, we aimed to evaluate the underlying mechanism and to differentiate it on imaging from other pathology with similar clinical orbital features. METHODS: Between November 2016 and November 2018, we performed a retrospective single-center study of 250 patients who underwent anterior circulation mechanical thrombectomy. Development of exophthalmos was independently evaluated by two readers on preprocedure and 24-h postprocedure non-contrast cerebral CT. RESULTS: In the mechanical thrombectomy cohort, six individuals (2.4%) developed interval ipsilateral exophthalmos at 24 h. Of these, at least two patients developed clinical symptoms. There was almost perfect agreement between assessments of the two readers (Cohen's kappa = 0.907 (95% confidence interval: 0.726, 1.000)). In two patients, there was delayed ophthalmic artery filling on digital subtraction angiography. None of the patients had features of a direct carotid-cavernous fistula. CONCLUSIONS: Exophthalmos is not uncommon after mechanical thrombectomy (2.4%). The underlying mechanism is difficult to confirm, but it is most likely due to orbital ischemia from hypoperfusion or distal emboli.

Fractional Quantum Hall Effect in Weyl Semimetals.

Weyl semimetal may be thought of as a gapless topological phase protected by the chiral anomaly, where the symmetries involved in the anomaly are the U(1) charge conservation and the crystal translational symmetry. The absence of a band gap in a weakly interacting Weyl semimetal is mandated by the electronic structure topology and is guaranteed as long as the symmetries and the anomaly are intact. The nontrivial topology also manifests in the Fermi arc surface states and topological response, in particular taking the form of an anomalous Hall effect in magnetic Weyl semimetals, whose magnitude is only determined by the location of the Weyl nodes in the Brillouin zone. Here we consider the situation when the interactions are not weak and ask whether it is possible to open a gap in a magnetic Weyl semimetal while preserving its nontrivial electronic structure topology along with the translational and the charge conservation symmetries. Surprisingly, the answer turns out to be yes. The resulting topologically ordered state provides a nontrivial realization of the fractional quantum Hall effect in three spatial dimensions in the absence of an external magnetic field, which cannot be viewed as a stack of two dimensional states. Our state contains loop excitations with nontrivial braiding statistics when linked with lattice dislocations.

Giant reed growth and effects on soil biological fertility in assisted phytoremediation of an industrial polluted soil.

Phytoremediation is a cost-effective "green technology" that uses plants to improve the soil properties of polluted sites, preventing the dispersion of pollutants and reducing the mobility of potentially toxic elements (PTEs) through their adsorption and accumulation by roots or precipitation within the root zone. Being highly tolerant to pollutants and other abiotic stresses, giant reed (Arundo donax L.) is a suitable biomass crop for phytoremediation of contaminated soils. We report the results of a two-year open-air lysimeter study aimed at assessing the adaptability of giant reed to grow on industrial substrates polluted by Pb and Zn and at testing commercial humic acids from leonardite as improvers of plant performance. We evaluated giant reed potential for: 1) biomass production for energy or biomaterial recovery; 2) PTE phytoextraction and 3) soil fertility restoration. Chemical fertility was monitored by measuring soil C while soil biological fertility was estimated by quantifying the abundance of bacterial functional genes regulating nitrogen fixation (nifH) and nitrification (amoA). Giant reed above-ground growth on the polluted soils was slightly lower (-16%) than on a non-polluted soil, with a preferential storage of biomass in the rhizome acting as a survival strategy in limiting growing conditions. Humic acids improved plant stress tolerance and production levels. As aerial biomass (shoots) did not accumulate PTEs, the plant in question can be used for bioenergy or biopolymer production. In contrast, below-ground biomass (rhizomes) accumulated PTEs, and can thus be harvested and removed from soil to improve phytoremediation protocols and also used as industrial biofuel. Giant reed growth increased the abundance of N-cycling bacteria and soil C in the rhizospheric soil, as well as reduced soil Pb and Zn EDTA extractable fraction.

Cerebral Perfusion Pressure is Maintained in Acute Intracerebral Hemorrhage: A CT Perfusion Study.

BACKGROUND AND PURPOSE: Although blood pressure reduction has been postulated to result in a fall in cerebral perfusion pressure in patients with intracerebral hemorrhage, the latter is rarely measured. We assessed regional cerebral perfusion pressure in patients with intracerebral hemorrhage by using CT perfusion source data. MATERIALS AND METHODS: Patients with acute primary intracerebral hemorrhage were randomized to target systolic blood pressures of <150 mm Hg (n = 37) or <180 mm Hg (n = 36). Regional maps of cerebral blood flow, cerebral perfusion pressure, and cerebrovascular resistance were generated by using CT perfusion source data, obtained 2 hours after randomization. RESULTS: Perihematoma cerebral blood flow (38.7 ± 11.9 mL/100 g/min) was reduced relative to contralateral regions (44.1 ± 11.1 mL/100 g/min, P = .001), but cerebral perfusion pressure was not (14.4 ± 4.6 minutes(-1) versus 14.3 ± 4.8 minutes(-1), P = .93). Perihematoma cerebrovascular resistance (0.34 ± 0.11 g/mL) was higher than that in the contralateral region (0.30 ± 0.10 g/mL, P < .001). Ipsilateral and contralateral cerebral perfusion pressure in the external (15.0 ± 4.6 versus 15.6 ± 5.3 minutes(-1), P = .15) and internal (15.0 ± 4.8 versus 15.0 ± 4.8 minutes(-1), P = .90) borderzone regions were all similar. Borderzone cerebral perfusion pressure was similar to mean global cerebral perfusion pressure (14.7 ± 4.7 minutes(-1), P ≥ .29). Perihematoma cerebral perfusion pressure did not differ between blood pressure treatment groups (13.9 ± 5.5 minutes(-1) versus 14.8 ± 3.4 minutes(-1), P = .38) or vary with mean arterial pressure (r = -0.08, [-0.10, 0.05]). CONCLUSIONS: Perihematoma cerebral perfusion pressure is maintained despite increased cerebrovascular resistance and reduced cerebral blood flow. Aggressive antihypertensive therapy does not affect perihematoma or borderzone cerebral perfusion pressure. Maintenance of cerebral perfusion pressure provides physiologic support for the safety of blood pressure reduction in intracerebral hemorrhage.

Insular ischemic stroke: clinical presentation and outcome.

BACKGROUND: The insula is a small but complex structure located in the depth of the sylvian fissure, covered by the frontal, parietal and temporal operculum. Ischemic strokes limited to the insula are rare and have not been well studied. Our objective is to better define the clinical presentation and outcome of insular ischemic strokes (IIS). METHODS: We reviewed the institutional prospective, consecutive stroke database from two centers to identify patients with IIS seen between 2008 and 2010. We also searched the Medline database using the keywords insula(r), infarction and stroke to identify previously published IIS cases confirmed by MRI. Minimal extension to an adjacent operculum or subinsular area was accepted. Clinicoradiological correlation was performed by distinguishing IIS involving the anterior (AIC) or posterior insular cortex (PIC). We collected clinical, demographic and radiological data. The outcome was determined using the modified Rankin Scale (mRS). RESULTS: We identified 7 patients from our institutions and 16 previously published cases of IIS. Infarcts were limited to the AIC (n = 4) or the PIC (n = 12) or affected both (n = 7). The five most frequent symptoms were somatosensory deficits (n = 10), aphasia (n = 10), dysarthria (n = 10), a vestibular-like syndrome (n = 8) and motor deficits (n = 6). A significant correlation was found between involvement of the PIC and somatosensory manifestations (p = 0.04). No other statistically significant associations were found. IIS presentation resembled a partial anterior circulation infarct (n = 9), a lacunar infarct (n = 2) or a posterior circulation infarct (n = 2). However, most cases presented findings that did not fit with these classical patterns (n = 10). At the 6 month follow up, mRS was 0 in 8/23 (35%) patients, 1-2 in 7/23 (30%) and unknown in 8/23 (35%). CONCLUSIONS: IIS presentation is variable. Due to the confluence of functions in a restricted region, it results in multimodal deficits. It should be suspected when vestibular-like or motor but especially somatosensory, speech or language disturbances are combined in the same patient. The outcome of IIS is often favorable. Larger prospective studies are needed to better define the clinical presentation and outcome of IIS.

An evaluation of the dot-ELISA procedure as a diagnostic test in an area with a high prevalence of human Toxocara canis infection.

The aim of this work was to evaluate a dot-enzyme-linked immunosorbent assay (dot-ELISA) using excretory-secretory antigens from the larval stages of Toxocara canis for the diagnosis of toxocariasis. A secondary aim was to establish the optimal conditions for its use in an area with a high prevalence of human T. canis infection. The dot-ELISA test was standardised using different concentrations of the antigen fixed on nitrocellulose paper strips and increasing dilutions of the serum and conjugate. Both the dot-ELISA and standard ELISA methods were tested in parallel with the same batch of sera from controls and from individuals living in the problem area. The best results were obtained with 1.33 µg/mL of antigen, dilutions of 1/80 for the samples and controls and a dilution of 1/5,000 for the anti-human IgG-peroxidase conjugate. All steps of the procedure were performed at room temperature. The coincidence between ELISA and dot-ELISA was 85% and the kappa index was 0.72. The dot-ELISA test described here is rapid, easy to perform and does not require expensive equipment. Thus, this test is suitable for the serological diagnosis of human T. canis infection in field surveys and in the primary health care centres of endemic regions.

An evaluation of the dot-ELISA procedure as a diagnostic test in an area with a high prevalence of human Toxocara canis infection

The aim of this work was to evaluate a dot-enzyme-linked immunosorbent assay (dot-ELISA) using excretory-secretory antigens from the larval stages of Toxocara canis for the diagnosis of toxocariasis. A secondary aim was to establish the optimal conditions for its use in an area with a high prevalence of human T. canis infection. The dot-ELISA test was standardised using different concentrations of the antigen fixed on nitrocellulose paper strips and increasing dilutions of the serum and conjugate. Both the dot-ELISA and standard ELISA methods were tested in parallel with the same batch of sera from controls and from individuals living in the problem area. The best results were obtained with 1.33 µg/mL of antigen, dilutions of 1/80 for the samples and controls and a dilution of 1/5,000 for the anti-human IgG-peroxidase conjugate. All steps of the procedure were performed at room temperature. The coincidence between ELISA and dot-ELISA was 85 percent and the kappa index was 0.72. The dot-ELISA test described here is rapid, easy to perform and does not require expensive equipment. Thus, this test is suitable for the serological diagnosis of human T. canis infection in field surveys and in the primary health care centres of endemic regions.

Systemic adverse events during 2005 phacoemulsifications under monitored anesthesia care: a prospective evaluation.

BACKGROUND: The aim of the study was to evaluate the systemic adverse events triggering on-call anesthesiologist's intervention during 2005 phacoemulsification under topical anesthesia on a day-surgery monitored anesthesia care regimen. METHODS: Adverse events triggering an anesthesiologist call by the attending nurse were registered. Comorbidities (7 categories), age, gender, body mass index, ASA status, length of surgery, time of the day of surgery and operated eye (first/second) were analyzed as potentially predictive factors. Odds Ratios are expressed as OR (95% CI). RESULTS: The anesthesiologist was called in 433 (21.6%) cases: age (5-yr-OR 0.95 [0.91-0.99]), ASA status 3-4 (OR 1.37 [1.02-1.85]), positive neurological history (OR 1.60 [1.06-2.40]), positive psychiatric history (OR 2.56 [1.34-4.93]) and length of surgery (OR 1.03 [1.01-1.06]) were predictive of the anesthesiologist call. Arterial hypertension (10.3%) and agitation (9.5%) were the most frequent adverse events. Age (5-yr-OR 1.27 [1.16-1.38]) and ASA status 3-4 (OR 1.83 [1.30-2.56]) were predictive of arterial hypertension. Age (5-yr-OR 0.80 [0.76-0.85]), positive neurological history (OR 1.86 [1.10-3.14]) and positive psychiatric history (OR 4.48 [2.26-8.88]) were predictive of agitation. Interruption of surgery was never required. CONCLUSION: One-day cataract surgery performed under topical anesthesia with monitored anesthesia care required anesthesiologist intervention in 21.6% of cases, mainly because of agitation or hypertension. Agitation occurred more often in younger patients with neurological or psychiatric comorbidities. Hypertension occurred more often in older patients with higher ASA scores.

Fusion as the result of sperm-somatic cell interaction.

The research has been designed to investigate whether acrosome-reacted spermatozoa can fuse with somatic cells and to check whether this event may involve the molecular machinery implicated in the sperm-egg fusion. Boar spermatozoa were capacitated in vitro and then treated with A23187 to induce acrosome reaction and activate their fusogenic potential. Reacted spermatozoa, loaded with the membrane-permeant fluorescent dye calcein AM, were incubated with plated granulosa cells or cells derived from stable cell lines: CRFK, VERO, and ESK4. The fusion between spermatozoa and somatic cells was revealed by the diffusion of the fluorescent dye from the sperm to the cell as membrane fusion and cytoplasmic continuity between the two cells were established. The involvement of integrin alpha6 and tetraspanin CD9 in the process of fusion was assessed by carrying out the experiment in the presence of antibodies against these molecules. Moreover, the incidence of fusion displayed by the different cell types used was analyzed in relation to their content in the above molecules assessed by western blot and immunostaining. The role of CD9 was additionally investigated by using CD9-negative cells. The data presented demonstrate that boar spermatozoa can fuse with different somatic cell types derived from different species and the process requires the combined presence of both integrin and tetraspanin molecules on the cell plasma membrane.

Synthesis and biological activity of Akt/PI3K inhibitors.

Phosphatidylinositol 3-kinase (PI3K) and serine/threonine protein kinase B (PKB or Akt) pathways regulate important cellular processes and are related to a number of human pathologies, such as cancer. The development of kinase inhibitors, with particular attention to small molecule analogues of natural phosphoinositides for pathway interruption and therapeutic applications will be reviewed.

Spatio-temporal analysis of vascular endothelial growth factor expression and blood vessel remodelling in pig ovarian follicles during the periovulatory period.

Vascular endothelial growth factor (VEGF) expression pattern and blood vessel remodelling were evaluated during the transition from the preovulatory follicle to the corpus luteum (CL). To this end, prepubertal gilts were treated with equine chorionic gonadotrophin (eCG) to collect preovulatory follicles (60 h after eCG) and with human chorionic gonadotrophin (hCG) to obtain periovulatory follicles 18 h and 36 h later. The VEGF mRNA content was analysed by in situ hybridization, while protein localization in follicular fluid (FF) and in granulosa and theca compartments was evaluated by ELISA, immunohistochemistry or western blot. Blood vessel architecture and vascular area (VA) were investigated using immunohistochemistry for von Willenbrand Factor, a specific endothelial marker. Vascular remodelling was finally tested using Ki-67 immunocytochemistry as a proliferation marker, or alpha-smooth muscle actin (alpha-SMA) as a specific mural cell marker. eCG-treated follicles showed high VEGF levels and two concentric blood vessel networks composed of proliferating endothelial cells without any association with mural components. hCG injection inhibited VEGF synthesis in the granulosa compartment and, as a consequence, the protein fell within the FF. In parallel, endothelial cell proliferation stopped and the VA decreased. Close to ovulation, VEGF production restarted in both follicular compartments and VEGF mRNA content significantly increased in the theca layer. Changes in follicular VEGF secretion were observed; the protein disappeared from FF and was observed in the extracellular matrix. An active angiogenesis characterized the follicle; endothelial cell proliferation was associated with a recruitment of alpha-SMA-positive mural cells. The data presented in this work showed that, in the phases preceding ovulation, a complete vascular remodelling occurs, characterized by both an evident neovascularization and the appearance of blood vessels presenting smooth musculature which could be involved in CL formation after ovulation.

ETHE1 mutations are specific to ethylmalonic encephalopathy.

Mutations in ETHE1, a gene located at chromosome 19q13, have recently been identified in patients affected by ethylmalonic encephalopathy (EE). EE is a devastating infantile metabolic disorder, characterised by widespread lesions in the brain, hyperlactic acidaemia, petechiae, orthostatic acrocyanosis, and high levels of ethylmalonic acid in body fluids. To investigate to what extent ETHE1 is responsible for EE, we analysed this gene in 29 patients with typical EE and in 11 patients presenting with early onset progressive encephalopathy with ethylmalonic aciduria (non-EE EMA). Frameshift, stop, splice site, and missense mutations of ETHE1 were detected in all the typical EE patients analysed. Western blot analysis of the ETHE1 protein indicated that some of the missense mutations are associated with the presence of the protein, suggesting that the corresponding wild type amino acid residues have a catalytic function. No ETHE1 mutations were identified in non-EE EMA patients. Experiments based on two dimensional blue native electrophoresis indicated that ETHE1 protein works as a supramolecular, presumably homodimeric, complex, and a three dimensional model of the protein suggests that it is likely to be a mitochondrial matrix thioesterase acting on a still unknown substrate. Finally, the 625G-->A single nucleotide polymorphism in the gene encoding the short chain acyl-coenzyme A dehydrogenase (SCAD) was previously proposed as a co-factor in the aetiology of EE and other EMA syndromes. SNP analysis in our patients ruled out a pathogenic role of SCAD variants in EE, but did show a highly significant prevalence of the 625A alleles in non-EE EMA patients.

Expression of the chemokine receptor CCR3 on human mast cells.

BACKGROUND: The aim of this study was to investigate whether human mast cells express functional active CCR3 receptors, which are activated by CC chemokines. These ligands include the CCR3-selective chemokines eotaxin and eotaxin-2 and the more promiscuous CC chemokines, MCP-4, MCP-3, MCP-2 and RANTES. METHODS: Immunohistochemical analysis was performed on skin, gut and lung specimens. Double immunostaining was performed with anti-CCR3 and antitryptase, and anti-CCR3 and antichymase antibody (Ab) by using the avidin-biotin-peroxidase system with two different substrates. Mast cells were isolated and purified from human lung parenchyma (HLMC) by countercurrent elutriation followed by discontinuous Percoll density gradient. Flow-cytometric analysis of HLMC surface CCR3 expression was performed with the monoclonal Ab anti-CCR3 (7B11). Functional activation of HLMC was verified by the ability of cells to release histamine and/or migrate in response to eotaxin. RESULTS: High percentages (>70%) of tryptase-positive cells showing CCR3 expression were found in the skin and in the intestinal submucosa, whereas much lower percentages (< or = 20%) were found in the intestinal mucosa and in the lung interstitium. Eotaxin (1-100 nM) neither induced histamine release from HLMC nor enhanced anti-IgE-induced histamine release. In contrast, eotaxin (10-100 nM) and RANTES (10-100 nM) induced HLMC chemotaxis in vitro. Preincubation of HLMC with antibody anti-CCR3 (5 microg/ml) before loading into the chemotaxis chamber abrogated chemotaxis elicited by eotaxin. Double immunostaining with anti-CCR3 and anti-chymase antibody showed that the vast majority of CCR3-expressing mast cells in the various human tissues examined were tryptase-chymase double-positive. CONCLUSIONS: These results indicate that CCR3 is expressed on human mast cells and that these cells are attracted by CCR3-binding chemokines.