Comprehensive analysis of lung macrophages and dendritic cells in two murine models of allergic airway inflammation reveals model- and subset-specific accumulation and phenotypic alterations

Introduction

Allergic asthma has been mainly attributed to T helper type 2 (Th2) and proinflammatory responses but many cellular processes remain elusive. There is increasing evidence for distinct roles for macrophage and dendritic cell (DC) subsets in allergic airway inflammation (AAI). At the same time, there are various mouse models for allergic asthma that have been of utmost importance in identifying key inflammatory pathways in AAI but that differ in the allergen and/or route of sensitization. It is unclear whether and how the accumulation and activation of specialized macrophage and DC subsets depend on the experimental model chosen for analyses.

Methods

In our study, we employed high-parameter spectral flow cytometry to comprehensively assess the accumulation and phenotypic alterations of different macrophage- and DC-subsets in the lung in an OVA- and an HDM-mediated mouse model of AAI.

Results

We observed subset-specific as well as model-specific characteristics with respect to cell numbers and functional marker expression. Generally, alveolar as opposed to interstitial macrophages showed increased MHCII surface expression in AAI. Between the models, we observed significantly increased numbers of alveolar macrophages, CD103+ DC and CD11b+ DC in HDM-mediated AAI, concurrent with significantly increased airway interleukin-4 but decreased total serum IgE levels. Further, increased expression of CD80 and CD86 on DC was exclusively detected in HDM-mediated AAI.

Discussion

Our study demonstrates a model-specific involvement of macrophage and DC subsets in AAI. It further highlights spectral flow cytometry as a valuable tool for their comprehensive analysis under inflammatory conditions in the lung.

Streptococcus pneumoniae Affects Endothelial Cell Migration in Microfluidic Circulation

Bloodstream infections caused by Streptococcus pneumoniae induce strong inflammatory and procoagulant cellular responses and affect the endothelial barrier of the vascular system. Bacterial virulence determinants, such as the cytotoxic pore-forming pneumolysin, increase the endothelial barrier permeability by inducing cell apoptosis and cell damage. As life-threatening consequences, disseminated intravascular coagulation followed by consumption coagulopathy and low blood pressure is described. With the aim to decipher the role of pneumolysin in endothelial damage and leakage of the vascular barrier in more detail, we established a chamber-separation cell migration assay (CSMA) used to illustrate endothelial wound healing upon bacterial infections. We used chambered inlets for cell cultivation, which, after removal, provide a cell-free area of 500 μm in diameter as a defined gap in primary endothelial cell layers. During the process of wound healing, the size of the cell-free area is decreasing due to cell migration and proliferation, which we quantitatively determined by microscopic live cell monitoring. In addition, differential immunofluorescence staining combined with confocal microscopy was used to morphologically characterize the effect of bacterial attachment on cell migration and the velocity of gap closure. In all assays, the presence of wild-type pneumococci significantly inhibited endothelial gap closure. Remarkably, even in the presence of pneumolysin-deficient pneumococci, cell migration was significantly retarded. Moreover, the inhibitory effect of pneumococci on the proportion of cell proliferation versus cell migration within the process of endothelial gap closure was assessed by implementation of a fluorescence-conjugated nucleoside analogon. We further combined the endothelial CSMA with a microfluidic pump system, which for the first time enabled the microscopic visualization and monitoring of endothelial gap closure in the presence of circulating bacteria at defined vascular shear stress values for up to 48 h. In accordance with our CSMA results under static conditions, the gap remained cell free in the presence of circulating pneumococci in flow. Hence, our combined endothelial cultivation technique represents a complex in vitro system, which mimics the vascular physiology as close as possible by providing essential parameters of the blood flow to gain new insights into the effect of pneumococcal infection on endothelial barrier integrity in flow.

A comparison of 3 methods of face-bow transfer recording: implications for orthognathic surgery

PURPOSE

The purpose of this study was to compare the occlusal plane inclination of models mounted using 3 different systems for face-bow transfer with the actual occlusal plane inclination as measured on a cephalometric radiograph.

PATIENTS AND METHODS

Twenty-two subjects were enrolled in this study. Three alginate impressions of the maxillary dentition were taken, and 3 stone dental models were produced for each subject. Face-bow recordings were obtained on each subject using the SAM Anatomical Face-bow (Great Lakes Orthodontics Products, Ltd, Tonawanda, NY), the Erickson Surgical Face-bow (Great Lakes Orthodontics Products, Ltd) and a new technique developed by one of the authors (J.G.). For each subject, the dental models were mounted on a SAM articulator using each of the 3 face-bow recordings. Finally, a lateral cephalometric radiograph was obtained for each subject. The occlusal plane inclination was measured on the models and on the cephalometric radiographs. Differences among groups were tested using a 1-way analysis of variance. Bonferroni test was used for post hoc comparison between different pairs of groups.

RESULTS

The average occlusal plane inclination using the SAM Anatomical Face-bow was 7.8 degrees +/- 4.2 degrees greater than the actual-a difference that was statistically significant. The mean occlusal plane inclination of the models obtained using the Erickson Surgical Face-bow was 4.4 degrees +/- 2.2 degrees greater than the actual-a difference that was also statistically significant. The mean occlusal plane inclination of the models obtained by the new technique was only 0.9 degrees +/- 1.2 degrees greater than the actual; this difference was not statistically significant.

CONCLUSIONS

The new mounting technique is more accurate than the conventional SAM Face-bow or the Erickson Face-bow for reproducing the actual occlusal plane inclination.

Transient bacteremia due to Mycobacterium avium complex in patients with AIDS

It is generally assumed that Mycobacterium avium complex (MAC) bacteremia, once it develops, is unremitting. On the basis of this presumption, changes in the level of mycobacteremia are used to gauge therapeutic response. In 7 (12%) of 60 patients enrolled in a prospective trial of MAC bacteremia and AIDS, bacteremia became undetectable before the initiation of antimycobacterial therapy. Patients with transient bacteremia reported fewer and shorter symptoms and survived longer than those with sustained bacteremia (59 vs. 31 weeks; P = .022). There was no difference in the duration of AIDS, CD4+ cell count, hematocrit, or body weight between groups. Two additional patients with transient bacteremia were identified outside this study setting. Despite disappearance of detectable mycobacteremia and subsequent administration of antimycobacterial agent(s), bacteremia once again became detectable in 6 patients 4-45 weeks after their negative pretreatment cultures. Patients with disseminated MAC may have fluctuating levels of mycobacteremia that become undetectable in the absence of antimycobacterial therapy.

Factors influencing breast-feeding among adolescents

During a 15-month study period, 244 adolescent mothers under 18 years of age were surveyed, of whom 53% elected to breast-feed. A subset of 60 primiparous breast-feeding adolescents were studied regarding the influence of several factors on the duration of breast-feeding. An attitude questionnaire was administered in the hospital within 48 hours of delivery. Follow-up interviews were obtained by telephone or in person at approximately 2 weeks and 2 months after birth. Eighty-three percent made the decision to breast-feed before the third trimester. Thirty-five percent discontinued breast-feeding within the first postpartum month, the most common reason being "nipple confusion" in the infant; 22% nursed for more than 1 month but less than 2 months, and 43% breast-fed for 2 months or more. None of the variables examined (maternal age, ethnic group, education level, involvement of the baby's father, timing of the breast-feeding decision, intended duration of breast-feeding, age at which formula supplementation was started, or availability of maternal support) was predictive of the duration of breast-feeding. Contrary to adolescent stereotypes, 65% of mothers chose breast-feeding because it was "good for the baby," and 67% identified the "closeness" of the nursing relationship as the most enjoyable part of breast-feeding. Twenty-eight percent cited modesty issues about breast-feeding as the greatest disadvantage, and 17% returned to work or school within the first 2 postpartum months, posing additional obstacles to breast-feeding. Our data suggest that adolescents are receptive to breast-feeding, but they may require close follow-up and anticipatory guidance tailored to their individual needs.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of two types of hospital feeding gift packs on duration of breast-feeding among adolescent mothers

Two hundred forty-four adolescent mothers under 18 years of age were surveyed during a 15-month period, and 53% elected to breast-feed. A subset of 60 primiparous breast-feeding adolescents were enrolled in an investigator-blind, randomized, prospective study to compare the effects on breast-feeding duration of a standard hospital discharge feeding gift pack containing formula and a specially designed study pack that was free of infant formula. Thirty-five percent of the 60 women breast-fed less than 1 month; 22% nursed longer than 1 month but less than 2 months; and 43% breast-fed more than 2 months. There was no significant difference in breast-feeding duration among mothers by gift pack group, although those who received the study gift pack rated it higher in usefulness (p less than (0.025). The provision of infant formula samples did not appear to have a deleterious effect on the duration of breast-feeding among a population of adolescent mothers.

Platelet collection and transfusion using the fenwal CS-3000 cell separator

A prototype model of the Fenwal CS-3000 Blood Cell Separator (Deerfield, IL) was studied for plateletpheresis in 63 donors and 5 transfusions in patients. Donor effects were consistent with platelet removal and mild hemodilution. The incidence of reactions (9 of 63) was low and all were mild "citrate" type. A two-hour collection yielded 4.0 +/- 0.72 x 10(11) platelets at an efficiency of 45 +/- 6.9 per cent. The product had little contamination with leukocytes (0.26 +/- 1.2 x 10(9) and red blood cells (hematocrit less than 1%). Morphology and pH were well preserved during 24 hours of storage. Four patients with uncomplicated aregenerative thrombocytopenia were transfused on five occasions, with a mean of 4.5 +/- 0.87 x 10(11) platelets resulting in a mean platelet count increment of 55,000/microliter and dramatic reduction in template bleeding times.

Possible nosocomial transmission of group Y Neisseria meningitidis among oncology patients

Within 4 days, two oncology patients in the Clinical Research Unit had bacteremia causes by group Y Neisseria meningitidis. Three additional patients, identified by prevalence survey, were found to have nasopharyngeal colonization with that serogroup, compared with only one employee (not associated with patients) and no family contacts. Infected and colonized (case) patients were located in the same or adjacent rooms but did not have close contact. A comparison of host and risk factors showed no significant differences between case patients and the other (control) patients located in the same rooms. In retrospect, the index patient, who had marked sputum production but was not isolated, had unrecognized meningococcal pneumonia and probably was the hospital source of a heavy, airborne dispersal of organisms to other patients. Respiratory isolation is warranted for patients with suspected N. meningitidis infection.

The Denver articulation screening exam

This report describes the development of an articulation-screening test for economically disadvantaged children. The test is unique in that it was designed for use by trained nonprofessional workers. Thirty-four sound elements were administered to over 1500 Anglos, blacks, and Mexican-Americans two and one-half to six years of age. They varied significantly on the production of four sounds, which were eliminated from further study. In their production of the remaining 30 sounds, no significant differences were noted among cultural groups or between males and females. Age normative data in pronunciation of the 30 sounds were combined for all three cultural groups and displayed in a percentile rank format for each age category. Validation studies using nonprofessional screeners established the fifteenth percentile as the cutoff point for referral of abnormal children. Test-retest reliability was 0.95. Application of the test to large populations of children and use of nonprofessional screeners are discussed.