The Initial Mass Function of Low-mass Stars and Brown Dwarfs in the W3 Complex.

We have used archival infrared images obtained with the Wide Field Camera 3 on board the Hubble Space Telescope to constrain the initial mass function of low-mass stars and brown dwarfs in the W3 star-forming region. The images cover 438 arcmin2, which encompasses the entire complex, and were taken in the filters F110W, F139M, and F160W. We have estimated extinctions for individual sources in these data from their colors and have dereddened their photometry accordingly. By comparing an area of the images that contains the richest concentration of previously identified W3 members to an area that has few members and is dominated by background stars, we have estimated the luminosity function for members of W3 with masses of 0.03-0.4 M ⨀. That luminosity function closely resembles data in typical nearby star-forming regions that have much smaller stellar populations than W3 (≲500 vs. several thousand objects). Thus, we do not find evidence of significant variations in the initial mass function of low-mass stars and brown dwarfs with star-forming conditions, which is consistent with recent studies of other distant massive star-forming regions.

Postoperative neck pain associated with an implantable microvascular ultrasonic Doppler: a case report.

Microvascular reconstruction in the head and neck has enabled the transfer of large amounts of tissue, and has improved functional and cosmetic outcomes for patients. Its success is primarily dependent on adequate perfusion, and though many methods have been used to monitor the circulation of flaps, the Cook-Swartz implantable Doppler has gained favour with surgeons and nursing staff. We present the unusual case of a patient who had developed recurrent infection and pain that was associated with its use.

The ophthalmic blade perfectly made to create an oral antral communication blockade; a technical note.

Oral antral fistulas are commonly referred to the Oral and Maxillofacial department for surgical management. Though conventional methods of repair are well established, we present a technical note highlighting the novel use of an ophthalmic blade in raising palatal mucoperiosteal flaps. We have experienced much success with this instrument and believe it represents a very useful and complimentary addition to the oral and maxillofacial surgeon's kit.

Biodiversity and ecosystem functioning: current knowledge and future challenges.

The ecological consequences of biodiversity loss have aroused considerable interest and controversy during the past decade. Major advances have been made in describing the relationship between species diversity and ecosystem processes, in identifying functionally important species, and in revealing underlying mechanisms. There is, however, uncertainty as to how results obtained in recent experiments scale up to landscape and regional levels and generalize across ecosystem types and processes. Larger numbers of species are probably needed to reduce temporal variability in ecosystem processes in changing environments. A major future challenge is to determine how biodiversity dynamics, ecosystem processes, and abiotic factors interact.

Music therapy in palliative medicine.

A partnership between The Cleveland Clinic Foundation and The Cleveland Music School Settlement has resulted in music therapy becoming a standard part of the care in our palliative medicine inpatient unit. This paper describes a music therapy program and its impact on patients, their families, and staff. A service delivery model is suggested for implementation and integration of music therapy within palliative medicine. Specific music therapy interventions, evaluation and documentation techniques are also mentioned. A description of patient and family responses to music therapy, staff satisfaction, and effectiveness of interventions is presented.

The effect of music-based imagery and musical alternate engagement on the burn debridement process.

Management of pain is a primary concern in the treatment of burn patients. The intent of this study was to test the efficacy of music-based imagery and musical alternate engagement in assisting burn patients in managing their pain and anxiety during debridement. Twenty-five patients, 7 years of age and older, who were admitted to the Comprehensive Burn Care Center were enrolled in the study, which used a repeated-measures design with subjects serving as their own control. Subjects were randomly assigned to 1 of 2 groups. Those placed in Group A received music therapy intervention during their first dressing change, and no music therapy on the following day. Group B received no music therapy intervention during their first dressing change and music therapy during their next dressing, on the following day. Data were collected at 4 intervals in the medical procedure; in the patient's room before transfer to the treatment room, in the treatment room during debridement, in the treatment room after debridement, and upon returning to the patient's room. The measurements taken were pulse, patients' self-report of pain, patients' self-report of anxiety, and the nurse's observation of patients' tension. There was a significant reduction in the self-reporting of pain in those who received music therapy in contrast to those who did not receive music therapy (P < .03). Music therapy is a valuable noninvasive intervention for the treatment of pain after burn injury.

TNF-alpha and IL-1beta cross-desensitization of astrocytes and astrocytoma cell lines.

Exposure of human astrocytes and astrocytoma cell lines to TNF-alpha, IL-1beta and gammaIFN induce expression of a specific member of the intercrine/chemokine family of cytokines, RANTES. Pre-incubation with non-stimulatory concentrations of TNF-alpha inhibit IL-1beta-stimulated RANTES expression and similarly, non-stimulatory concentrations of IL-1beta inhibits TNF-alpha induced RANTES expression. The lowered responsiveness of these cells is stably maintained for at least 24 h. The inhibitory effect of TNF-alpha on IL-1beta-induced responses was mediated by TNF receptor-1 since low concentrations of a specific anti-TNF receptor-1 antiserum mimicked the inhibitory effect. These results indicate that TNF and IL-1 receptors mediate pro- and antiinflammatory responses in a concentration dependent manner, suggesting that at low receptor occupancy, TNF and IL-1 receptors may share a common signaling pathway and behave as endogenous antiinflammatory cytokines.

Production of IL-5 and granulocyte-macrophage colony-stimulating factor by naive human mast cells activated by high-affinity IgE receptor ligation.

BACKGROUND: The late-phase allergic reaction is an eosinophilic inflammatory response that begins several hours after allergen exposure, may persist for 24 hours, and is an important pathogenic mechanism in allergic disease. OBJECTIVE: Cultured naive human mast cells were used to investigate whether mast cells are a direct source of the eosinophil-promoting cytokines IL-5, IL-3, and granulocyte-macrophage colony-stimulating factor (GM-CSF). METHODS: Naive human mast cells were derived from bone marrow mononuclear cells cultured in the presence of stem-cell factor. Cytokine message and protein production in response to high-affinity IgE receptor ligation of cultured mast cells were measured by semiquantitative polymerase chain reaction and ELISA, respectively. RESULTS: IL-5, IL-3, and GM-CSF messenger RNA increased within 2 hours of mast cell activation, with IL-5 and GM-CSF message remaining elevated for 24 hours, whereas IL-3 mRNA rapidly declined. IL-5 and GM-CSF protein were measurable 4 to 6 hours after stimulation and peaked by 24 and 12 hours, respectively. IL-3 protein was not detectable. CONCLUSION: These findings demonstrate that naive mast cells do not constitutively produce IL-5 or GM-CSF protein but are a major source of these eosinophilotropic cytokines on high-affinity IgE receptor ligation.

Induction of RANTES expression by astrocytes and astrocytoma cell lines.

The cellular infiltrate found during the acute phase of multiple sclerosis (MS) consists of monocytes and activated T cells, suggesting the presence of cell-specific chemotactic signals during the inflammatory response. We examined the ability of human astrocytoma cell lines, as well as primary human and rat astrocytes, to generate a specific member of the intercrine/chemokine family of cytokines, RANTES, when exposed to TNF-alpha, IL-1 beta and IFN-gamma. Astrocytoma cells as well as primary astrocytes produced RANTES upon incubation with TNF-alpha or IL-1 beta. IFN-gamma alone did not induce RANTES production by astrocytes, but it potentiated the effects of either TNF-alpha or IL-1 beta. Induction of RANTES by TNF-alpha was mediated by the p55 receptor since a specific anti-p55 antiserum mimicked the effect of TNF-alpha. These results indicate that human astrocytes are capable of generating a cell-specific chemokine that can account for the inflammatory cellular infiltrate observed during the acute phase of MS, in a process that is regulated by cytokines.

Delineation of IL-5 domains predicted to engage the IL-5 receptor complex.

IL-5 is an interdigitating homodimeric glycoprotein and a member of the helical bundle family of cytokines. IL-5 is a potent activator of eosinophils and a specific promoter of their differentiation. This activity has implicated IL-5 in the pathogenesis of asthma and allergic disease. A detailed understanding of IL-5 structure and function is required to develop immunomodulators of IL-5-mediated inflammatory responses. We generated a panel of neutralizing anti-IL-5 mAbs which were used to map functional domains on IL-5. In addition, the nucleotide sequences for human IL-5, murine IL-5, rat IL-5, and eight human/murine IL-5 chimeras were engineered and expressed in COS-7 cells. These recombinant cytokines and mAbs were used in TF-1 bioassays to identify five functional epitopes on the tertiary structure of IL-5. Residues responsible for the species-specific activity of human IL-5 were identified with the murine BCL1 bioassay. One set of epitopes cluster around the helix A-loop 2 region, which is predicted to engage the IL-5 receptor beta-chain. The second set of epitopes as well as the species specificity domain cluster around the loop 3-helix D region, which is predicted to engage the IL-5 receptor alpha-chain. Together, these analyses target the A/D helical face of IL-5 as the region involved in receptor engagement.

Human B cells express IL-5 receptor messenger ribonucleic acid and respond to IL-5 with enhanced IgM production after mitogenic stimulation with Moraxella catarrhalis.

The potential for IL-5 to regulate human B cells is controversial despite its well established role as a regulatory factor for murine B cells. We hypothesized that the mechanism by which human B cells were stimulated would, as with murine B cells, determine their potential to respond to IL-5. Since Staphylococcus aureus Cowan strain I (SAC) and Moraxella catarrhalis (MCat) stimulate human B cells by distinct interactions with cell-surface Ig, we compared their potential to induce an IL-5-responsive state by human B cells purified to homogeneity. Neither SAC alone nor SAC plus IL-5 stimulated Ig production, although microgram quantities of IgM were produced with SAC plus IL-2. In contrast, MCat induced microgram quantities of IgM by B cells in the absence of exogenous cytokines, and IL-5 significantly increased IgM production over twofold in the majority of donors. Synergism of IL-5 and IL-2 was detected using suboptimal concentrations of IL-2 with MCat-, but not SAC-, stimulated B cells. Donor B cells unresponsive to IL-5 when stimulated with MCat, became IL-5 responsive in the presence of IL-2. Since message for the IL-5R alpha, IL-5R beta, and soluble IL-5R alpha chains was detected in freshly isolated B cells, we further investigated whether IL-5 responsiveness to MCat, but not SAC, was due to their differential regulation of IL-5R mRNA. Surprisingly, stimulation by either MCat or SAC, without or with IL-2, increased both IL-5R alpha and IL-5R beta mRNA and decreased soluble IL-5R alpha mRNA. These studies demonstrate that, as with murine B cells, human B cells express message for IL-5R but can respond to IL-5 only if appropriately stimulated to undergo terminal differentiation.

Interferon (IFN) beta acts downstream of IFN-gamma-induced class II transactivator messenger RNA accumulation to block major histocompatibility complex class II gene expression and requires the 48-kD DNA-binding protein, ISGF3-gamma.

Interferon (IFN) gamma, a cardinal proinflammatory cytokine, induces expression of the gene products of the class II locus of the major histocompatibility complex (MHC), whereas IFN-alpha or -beta suppresses MHC class II expression. The mechanism of IFN-beta-mediated MHC class II inhibition has been unclear. Recently, a novel factor termed class II transactivator (CIITA) has been identified as essential for IFN-gamma-induced MHC class II transcription. We studied the status of IFN-gamma-induced CIITA messenger RNA (mRNA) accumulation and CIITA-driven transactivation in IFN-beta-treated cells and used cell lines that had defined defects in the type I IFN response pathway to address the roles of IFN signaling components in the inhibition of MHC class II induction. IFN-beta treatment did not suppress IFN-gamma-induced accumulation of CIITA mRNA. After cells were stably transfected with CIITA, endogenous MHC class II genes were constitutively expressed, and MHC class II promoters, delivered by transfection, were actively transcribed in CIITA-expressing cells. Expression of these promoters was significantly impaired by pretreatment with IFN-beta. These results suggest that IFN-beta acts downstream of CIITA mRNA accumulation, and acts in part by reducing the functional competence of CIITA for transactivating MHC class II promoters. IFN stimulated gene factor 3 (ISGF3) gamma was essential for IFN-beta to mediate inhibition of MHC class II induction, regardless of whether MHC class II transcription was stimulated by IFN-gamma or directly by CIITA expression. Results of these experiments suggest that inhibition of MHC class II in IFN-beta-treated cells requires expression of gene(s) directed by the ISGF3-IFN-stimulated response element pathway, and that these gene product(s) may act by blocking CIITA-driven transcription of MHC class II promoters.

Role of protein kinase C and tyrosine kinase activity in IFN-gamma-induced expression of the class II MHC gene.

Astrocytes are induced by interferon-gamma (IFN-gamma) to express class II major histocompatibility complex (MHC) antigens. Our previous studies demonstrated that IFN-gamma-initiated signaling events important for class II expression include activation of protein kinase C (PKC) and the Na+/H+ antiporter. We have extended these studies and found that protein tyrosine kinase (PTK) activity is also required for class II expression. Treatment of astrocytes with inhibitors specific for PKC and PTK blocked INF-gamma-induced class II gene transcription, mRNA expression, and protein expression. Immunoblotting and immunoprecipitation experiments demonstrated that IFN-gamma induced tyrosine phosphorylation of the p91 component of ISGF3, which is blocked by preincubation of cells with PTK inhibitors. Treatment of astrocytes with IFN-gamma and either PKC and PTK inhibitors changed the mobility and intensity of a nuclear factor, IFN-gamma-enhanced factor X, which binds to the X box of the class II MHC promoter. Taken together, these data provide evidence that activation of both PTK and PKC is required for IFN-gamma-induced expression of the class II gene.

Enhanced detection of human IL-5 in biological fluids utilizing murine monoclonal antibodies which delineate distinct neutralizing epitopes.

Interleukin 5 (IL-5) is a homodimeric cytokine arranged in a head-to-tail configuration covalently linked by two disulfide bonds. IL-5 has pleiotropic effects on murine and human leukocytes and has been implicated in the pathogenesis of many inflammatory disorders. To facilitate the study of functionally relevant IL-5 domains involved in receptor binding and to develop a highly sensitive and specific ELISA capable of detecting IL-5 in biological fluids, a library of murine anti-human IL-5 (hIL-5) mAb was generated to baculovirus expressed recombinant hIL-5 (rhIL-5). Fifteen subclones of seven hybridomas were characterized. All mAb bound hIL-5, but not murine IL-5 (mIL-5), and neutralized hIL-5 biological activity in the BCl1 proliferation assay. By competitive ELISA, the mAb were divided into two binding groups. Utilizing comparative analysis with TRFK-5, a rat anti-mIL-5 mAb crossreactive with hIL-5, at least three hIL-5 neutralizing epitopes were defined. By ELISA and Western analysis, each epitope was shown to be present as a conformationally identical pair on the hIL-5 dimer. Various combinations of mAb in sandwich ELISA were used to predict the relative proximity of each epitope pair. Utilizing mAb binding characteristics, highly sensitive and specific sandwich ELISA were developed with a minimum detection limit of 6.25 pg hIL-5/ml (P < 0.05). Quantitation of hIL-5 in both serum and bronchoalveolar lavage (BAL) fluid demonstrated the utility of these anti-hIL-5 mAb for investigating the role of hIL-5 in inflammation. These mAb should also serve as useful reagents for epitope mapping of functional hIL-5 domains.