RESUMO
Salter-Harris type III fractures of the distal humerus in a four-month-old male Labrador Retriever and a male crossbreed dog (estimated to be 3.5-months-old) are reported. Both fractures were treated with open reduction and interfragmentary compression by lag screw fixation. Both fractures healed and full limb use was regained at four weeks postoperatively. The occurrence of this unusual fracture type may be related to the physeal closure pattern of the distal humeral physis, and a different mechanism of injury compared to the more common Salter-Harris type IV fracture seen in this region.
Assuntos
Cães/lesões , Membro Anterior/patologia , Fixação Interna de Fraturas/veterinária , Fraturas do Úmero/veterinária , Animais , Cães/cirurgia , Membro Anterior/diagnóstico por imagem , Fraturas do Úmero/cirurgia , Masculino , RadiografiaRESUMO
Soluble CD44 proteins generated by proteolytic cleavage or aberrant intron retention have been shown to antagonize the ligand binding activity of the corresponding cell surface receptor, inducing apoptosis and inhibiting tumor growth. Interestingly, such findings appear to contradict recent studies demonstrating a correlation between the presence of high levels of soluble CD44 in the serum of cancer patients and poor prognosis. In the present study, we report the cloning of a novel, naturally occurring, differentially expressed, soluble CD44 isoform, designated CD44RC, which, in contrast to previously described soluble CD44 proteins, can dramatically enhance the hyaluronan binding activity of cell surface CD44. Sequence analysis suggests that CD44RC is generated by an alternative splicing event in which the 3' end of CD44 exon 2 is spliced into an internal splice acceptor site present within exon 18, altering reading frame and giving rise to a soluble protein with a unique COOH terminus. Functional studies suggest that CD44RC enhances hyaluronan binding by adhering to chondroitin sulfate side-chains attached to cell surface CD44, generating a multivalent complex with increased avidity for hyaluronan.
Assuntos
Adjuvantes Imunológicos/metabolismo , Receptores de Hialuronatos/química , Receptores de Hialuronatos/metabolismo , Ácido Hialurônico/metabolismo , Processamento Alternativo , Sequência de Aminoácidos , Sequência de Bases , Adesão Celular , Linhagem Celular , Sulfatos de Condroitina/metabolismo , Clonagem Molecular , Éxons , Humanos , Receptores de Hialuronatos/genética , Modelos Biológicos , Dados de Sequência Molecular , Ligação Proteica , Isoformas de Proteínas , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Células Tumorais CultivadasRESUMO
Immune reactivity in the central nervous system (CNS) in multiple sclerosis (MS) can be fuelled by activated T lymphocytes sequestered in the brain and those entering systemically. The perivascular cuff of the inflammatory lesion consists predominantly of T cells and macrophages, while the hypercellular interface between normal and degenerating myelin is comprised mainly of macrophages and activated microglia. MHC class II+ cells are abundant in the hypercellular zone and expression of both the polymorphic and invariant chains of the molecule are expressed beyond the plaque edge in the white matter where the staining is restricted largely to microglia. Under carefully controlled staining conditions expression of MHC class II can be demonstrated on microglia in control white matter. Thus the immunological privilege of the CNS does not appear to preclude constitutive expression of MHC antigens or prevent the traffic of activated lymphocytes into the brain parenchyma. However, the antigens priming the immune reaction in the CNS in MS and the role of antibodies in the demyelinating process remain a matter for speculation and the exact mechanisms of demyelination are as yet unresolved.
Assuntos
Inflamação/patologia , Esclerose Múltipla/fisiopatologia , Bainha de Mielina/patologia , Animais , Fenômenos Biomecânicos , Encéfalo/imunologia , Encéfalo/patologia , Humanos , Imuno-Histoquímica , Esclerose Múltipla/imunologia , Esclerose Múltipla/metabolismoRESUMO
A method has been developed to isolate microglia from adult human and rat brain cell suspensions by rosette formation via Fc receptors. Immunocytochemical characterisation of the cells immediately following isolation and after 7-10 days in vitro with a panel of monoclonal antibodies has demonstrated that microglia from adult brain have the phenotypic characteristics and phagocytic capacity of mononuclear phagocytes, but lack the hydrolytic enzyme, non-specific esterase. The ability to isolate rapidly a purified population of microglia from adult brain provides a means for investigating mechanisms of activation and differentiation of tissue macrophages, which could elucidate their role in inflammation of the central nervous system.
Assuntos
Encéfalo/citologia , Neuroglia/imunologia , Animais , Carboxilesterase , Hidrolases de Éster Carboxílico/análise , Separação Celular , Humanos , Imuno-Histoquímica , Neuroglia/enzimologia , Fagocitose , Ratos , Receptores Fc/análise , Formação de RosetaRESUMO
In vivo levels of interleukin-1 (IL-1) and IL-6, present in the interstitial spaces of brain, have been repeatedly monitored up to 7 days after insertion of a microdialysis probe, designed to induce mechanical trauma to the brain. IL-1 is barely detectable immediately after implantation but over a 24-48 h period a 15-fold increase is seen. In contrast IL-6 levels at day 0 are high, increasing slightly (10%) by day 1 but decreasing to 40% by day 2. The temporal pattern of IL-6 recovery in the cerebrospinal fluid was similar to that in the dialysate but the levels were significantly lower and may reflect diffusion from the site of the probe lesion. Cellular sources of these cytokines include macrophages and neutrophils, which have infiltrated the lesion and microglia resident in the brain, which can be identified at the lesion site within 24 h of probe implantation. The astrocytic response to injury, evidenced by increased glial fibrillary acidic protein staining occurs much later, by day 7, and is unlikely to be responsible for IL-1 and IL-6 production found at 24-48 h. Since upon isolation and stimulation of microglia in vitro with lipopolysaccharide IL-1 and IL-6 can be measured in the supernatant, it would appear that they have the capacity to produce cytokines in vivo. Localised synthesis of cytokines at sites of brain injury by microglia would further stimulate microglia in an autocrine manner and also propagate the astrocytic reaction.
Assuntos
Lesões Encefálicas/metabolismo , Encéfalo/metabolismo , Citocinas/biossíntese , Interleucina-1/metabolismo , Interleucina-6/metabolismo , Neuroglia/fisiologia , Animais , Diálise/métodos , Imuno-Histoquímica , Ratos , Ratos EndogâmicosRESUMO
Previous studies on beta-amyloid production have been carried out using transfected cells and cell lines. We measured the 40 and 42 amino acid forms of beta-amyloid released into the culture medium by primary human foetal mixed brain cell aggregate culture over 3 months. In this model, neurones and supporting cells are maintained in serum-free defined medium. The secretion of significant amounts of beta-amyloid 40 and 42 was observed throughout culture for three separate cultures. Levels of beta-amyloid 40 and 42 closely followed the neuronal content of the cultures as estimated by cellular neurone-specific enolase. Addition of synthetic beta-amyloid 1-40 to the cultures for 1 week at 35 days in vitro resulted in a dose-related reduction in cellular neurone-specific enolase levels. Primary human aggregate brain cell cultures produced multimeric beta-amyloid, as determined by immunoassay. beta-Amyloid-treated cultures released diminishing amounts of multimeric beta-amyloid and contained increasing amounts of intracellular multimeric beta-amyloid with increasing exogenous beta-amyloid. These results suggest that release of multimeric beta-amyloid into the extracellular environment by human primary neurones can be affected by the presence of extracellular beta-amyloid. This has implications for Alzheimer's disease in that beta-amyloid released into the extracellular environment by dead/dying neurones could modulate beta-amyloid release by surrounding neurones, potentially causing amplification of toxicity. Moreover, intracellular beta-amyloid oligomer-dependent neurotoxicity may be a component of neurodegeneration in Alzheimer's disease, and other conditions with increased beta-amyloid synthesis, suggesting anti-amyloid therapies for Alzheimer's disease may have to target intracellular beta-amyloid.
Assuntos
Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/farmacologia , Encéfalo/metabolismo , Neurônios/metabolismo , Peptídeos beta-Amiloides/efeitos dos fármacos , Encéfalo/citologia , Encéfalo/efeitos dos fármacos , Técnicas de Cultura de Células , Relação Dose-Resposta a Droga , Feto , Proteína Glial Fibrilar Ácida/efeitos dos fármacos , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Imunoensaio , Neurônios/efeitos dos fármacos , Fosfopiruvato Hidratase/efeitos dos fármacos , Fosfopiruvato Hidratase/metabolismo , SolubilidadeRESUMO
One difficulty in generating in vitro models of neuropathogenesis lies in maintaining stable proportions of primary neurons within a mixed brain cell population. Rotation-mediated fetal brain aggregate culture has been modified to permit growth of human primary fetal brain cells containing 50 to 60% neurons. After 12 weeks cholinesterase, neuron specific enolase and microtubule-associated protein-2 were demonstrable by biochemical assay and immunocytochemical labelling of cryostat sections of human fetal brain aggregates. Upon exposure to the glutamate agonist; N-methyl-D-aspartate for 7 days at 35 days in vitro neuron specific enolase and cholinesterase decreased to 60 to 70% of untreated levels. Glial fibrillary acidic protein did not change significantly but swollen astrocytes were seen in labelled sections of treated aggregates. This method is useful to study human neurotoxicity and degeneration in mixed glial culture without astrocyte overgrowth.
Assuntos
Astrócitos/citologia , Encéfalo/citologia , Técnicas de Cultura de Células/métodos , Agonistas de Aminoácidos Excitatórios/toxicidade , N-Metilaspartato/toxicidade , Neurônios/citologia , Astrócitos/efeitos dos fármacos , Separação Celular/métodos , Células Cultivadas , Feto/citologia , Humanos , L-Lactato Desidrogenase/análise , Microscopia Confocal , Degeneração Neural/induzido quimicamente , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Fosfopiruvato Hidratase/análise , RotaçãoRESUMO
In normal human white matter the predominant cell type expressing MHC Class II is the microglia. This population of cells reacts with the pan macrophage marker, EBM/11, and constitutes about 13% of the glial cell population. The intensity of staining was enhanced and the absolute number of Class II+ microglia increased in normal appearing white matter from multiple sclerosis (MS) brain. As T cell activation in MS may occur in the brain the upregulation of microglia bearing MHC Class II may reflect their function as antigen presenting cells in the development of inflammatory lesions.
Assuntos
Encéfalo/imunologia , Antígenos HLA-D/análise , Esclerose Múltipla/imunologia , Neuroglia/imunologia , Adulto , Idoso , Anticorpos Monoclonais , Contagem de Células , Antígenos HLA-DR/análise , Humanos , Técnicas Imunoenzimáticas , Macrófagos/imunologia , Pessoa de Meia-IdadeRESUMO
The sparse distributed memory (SDM) was originally developed to tackle the problem of storing large binary data patterns. The model succeeded well in storing random input data. However, its efficiency, particularly in handling nonrandom data, was poor. In its original form it is a static and inflexible system. Most of the recent work on the SDM has concentrated on improving the efficiency of a modified form of the SDM which treats the memory as a single-layer neural network. This paper introduces an alternative SDM, the SDM signal model which retains the essential characteristics of the original SDM, while providing the memory with a greater scope for plasticity and self-evolution. By removing many of the problematic features of the original SDM the new model is not as dependent upon a priori input values. This gives it an increased robustness to learn either random or correlated input patterns. The improvements in this new SDM signal model should be also of benefit to modified SDM neural network models.
RESUMO
OBJECTIVES: To determine the in vitro persistence of clotrimazole 1% cream in the canine frontal sinus and to evaluate the distribution of clotrimazole solution over the sino-nasal mucosa using a previously described surgical treatment protocol for canine nasal aspergillosis. METHODS: Two canine skulls were used to monitor the persistence of clotrimazole cream in the lateral frontal sinus at 37°C. The distribution of irrigation solution around the frontal sinus compartments and nasal cavity was determined using six canine cadaver heads by trephining either the lateral or both the lateral and rostral compartments of the frontal sinus. Stain was added to the sinus irrigation solution before visually inspecting the sagittally sectioned heads. RESULTS: Clotrimazole cream persisted in the frontal sinus for at least 96 hours. The nasal cavity mucosa was completely stained in 8 of 12 sides and almost completely stained in the remaining 4 of 12 sides. Flushing irrigation solution through the lateral compartment of the frontal sinus resulted in inadequate staining of the rostral compartment but medicating both the lateral and rostral compartments resulted in complete coating of all frontal sinus mucosa in eight of eight sides. CLINICAL SIGNIFICANCE: Clotrimazole cream has the potential to be retained in the frontal sinus for several days and is distributed effectively in normal canine cadavers. Medicating both the rostral and lateral compartments of the frontal sinus may be indicated in some clinical cases.
Assuntos
Antifúngicos/farmacocinética , Aspergilose/veterinária , Clotrimazol/farmacocinética , Doenças do Cão/tratamento farmacológico , Animais , Antifúngicos/administração & dosagem , Aspergilose/tratamento farmacológico , Aspergilose/metabolismo , Cadáver , Clotrimazol/administração & dosagem , Corantes , Doenças do Cão/metabolismo , Cães , Cavidade Nasal/metabolismo , Seios Paranasais/metabolismoRESUMO
OBJECTIVES: To report on a series of dogs and cats with long bone fractures that occurred as a direct consequence of linear external skeletal fixation (ESF) application. METHODS: Retrospective study. Data from the medical records and radiographs of canine (n = 4) and feline (n = 7) cases were collected from three referral and three first opinion practices in the UK (1999 to 2011). RESULTS: Long bone fractures occurred following the application of linear ESF either while the ESF was in situ or after removal. All fractures occurred through either a pin tract or an empty drill hole. Pins associated with ESF-related fracture tended to be in the higher end of the recommended size range. The majority of cases had additional complicating factors such as multiple injuries, revision surgery, poor owner compliance with postoperative exercise restriction and the presence of empty drill holes. CLINICAL SIGNIFICANCE: In cases with features that could complicate outcome, careful attention should be paid to recommendations for ESF application. Leaving empty drill holes is suboptimal. The retrospective nature of the study, low numbers of, and diversity amongst, cases should be taken into consideration when interpreting the results from this study.
Assuntos
Gatos/lesões , Cães/lesões , Fixadores Externos/veterinária , Fraturas do Fêmur/veterinária , Fraturas do Úmero/veterinária , Fraturas da Tíbia/veterinária , Animais , Fixadores Externos/efeitos adversos , Feminino , Fraturas do Fêmur/etiologia , Fraturas do Úmero/etiologia , Masculino , Estudos Retrospectivos , Fraturas da Tíbia/etiologiaRESUMO
OBJECTIVES: To investigate relationships between central venous oxygen saturation (ScvO(2)) and survival to hospital discharge in dogs. Central venous oxygen saturation is an accessible measure of the balance between systemic oxygen delivery and consumption. METHODS: Prospective observational cohort study, enrolling 126 client-owned dogs with central venous catheters. Central venous oxygen saturation was measured over the 24 hours following intensive care unit admission. Poor outcome was defined as death or euthanasia performed for moribund status. Regression analysis identified independent predictors of non-survival and physiologic parameters associated with central venous oxygen saturation. Area under the receiver operator curve analysis identified a cut-off point of central venous oxygen saturation, below which central venous oxygen saturation decrease was associated with increased mortality risk. RESULTS: Mortality risk was 30·9%. Low central venous oxygen saturation was associated with poor outcome (P<0·05). Area under the receiver operator curve analysis selected a central venous oxygen saturation of 68% as the point below which a fall in central venous oxygen saturation was associated with increased mortality risk. For each 10% drop in central venous oxygen saturation below 68%, odds of non-survival increased by 2·66 times (P=0·0002, 95% confidence interval of odds ratio=1·45 to 4·85). Central venous oxygen saturation was equivalent to lactate in predicting non-survival. Predictors of central venous oxygen saturation (packed cell volume, mean arterial blood pressure, fever, % arterial haemoglobin saturation as measured by pulse oximeter) were consistent with hypothesised physiologic mechanisms. CLINICAL SIGNIFICANCE: Central venous oxygen saturation was a strong mortality predictor. Further work is needed to determine if therapy targeting central venous oxygen saturation can reduce mortality in canine intensive care unit patients.
Assuntos
Estado Terminal/mortalidade , Cães/sangue , Oximetria/veterinária , Consumo de Oxigênio/fisiologia , Oxigênio/sangue , Animais , Área Sob a Curva , Cateterismo Venoso Central/veterinária , Estudos de Coortes , Cuidados Críticos , Doenças do Cão/sangue , Doenças do Cão/mortalidade , Feminino , Masculino , Monitorização Fisiológica/veterinária , Oxigênio/análise , Valor Preditivo dos Testes , Estudos Prospectivos , Curva ROCRESUMO
Otitis media with effusion (OME) is a common incidental finding in otherwise normal Cavalier King Charles spaniels (CKCS). In this study, measurements made on MRI were used to determine whether there was an association between OME and brachycephalic conformation. The results confirm that association and also demonstrate that, in CKCS, greater thickness of the soft palate and reduced nasopharyngeal aperture are significantly associated with OME. These results suggest that auditory tube dysfunction and OME may represent a previously overlooked consequence of brachycephalic conformation in dogs.
Assuntos
Doenças do Cão/etiologia , Nasofaringe/anatomia & histologia , Otite Média com Derrame/veterinária , Animais , Doenças do Cão/epidemiologia , Doenças do Cão/patologia , Cães , Tuba Auditiva/fisiopatologia , Incidência , Imageamento por Ressonância Magnética/veterinária , Otite Média com Derrame/epidemiologia , Otite Média com Derrame/etiologia , Palato Mole/anatomia & histologia , Fatores de Risco , Especificidade da EspécieRESUMO
OBJECTIVES: To determine the significant risk factors for medial meniscal injury in naturally occurring cranial cruciate ligament rupture and to quantify the risk using multivariate analysis. METHODS: A retrospective case control study was performed of dogs that had undergone surgery for cranial cruciate ligament rupture. Data recorded included patient signalment (age, breed and sex), the duration of the lameness, the extent of the cranial cruciate ligament rupture (complete or partial) and the condition of the medial meniscus. Logistic regression was used to analyse the relationship between these variables and tears in the medial meniscus. RESULTS: One hundred and sixty-one of 443 stifles (36·3%) in 366 dogs had a medial meniscal tear. The risk of a medial meniscal tear was increased by 12·9 times in association with complete cranial cruciate ligament rupture (OR 12·9; 95% CI 6·8 to 24·2), by approximately 2·6% for each additional week of lameness (OR 1·026; 95% CI 1·009 to 1·043) and by approximately 1·4% for each additional kilogram of bodyweight (OR 1·014; 95% CI 1·000 to 1·028). Golden retrievers and Rottweilers were at increased risk and West Highland white terriers were at reduced risk of medial meniscal tears compared with Labrador retrievers. CLINICAL SIGNIFICANCE: To minimise the risk of medial meniscal tears, surgical stabilisation should not be unnecessarily delayed.
Assuntos
Lesões do Ligamento Cruzado Anterior , Cães/lesões , Lesões do Menisco Tibial , Animais , Ligamento Cruzado Anterior/cirurgia , Peso Corporal/fisiologia , Cruzamento , Estudos de Casos e Controles , Cães/cirurgia , Feminino , Coxeadura Animal , Modelos Logísticos , Masculino , Meniscos Tibiais/cirurgia , Análise Multivariada , Prevalência , Estudos Retrospectivos , Fatores de Risco , Ruptura/cirurgia , Ruptura/veterinária , Joelho de Quadrúpedes/lesões , Joelho de Quadrúpedes/cirurgiaRESUMO
Exploiting the antitumor effect of natural killer (NK) cells has regained interest in light of data from preclinical and clinical work on the potential of alloreactive NK cells. Multiple myeloma (MM) and chronic lymphocytic leukemia (CLL) represent the two most prevalent adult hematological malignancies in the western hemisphere. To evaluate the role of NK cells in the immune surveillance and their therapeutic potential for CLL and MM, tumor cell susceptibility to NK-mediated killing was investigated. Results show relative resistance of tumor cells from CLL as well as MM (73 and 70% of the patients, respectively) to NK-mediated killing. To gain insight into molecular mechanisms of this resistance, the expression of the tolerogenic HLA-G molecule in CLL and MM and its relevance to susceptibility to NK-mediated killing were investigated. HLA-G transcript was found in tumor cells from 89% (n=19) of CLL and 100% (n=9) of MM patients examined. HLA-G1 surface expression was observed in CLL and was very low or undetectable in MM. Notably, blocking of HLA-G1 with specific antibody on CLL samples increased their susceptibility to NK-mediated killing, demonstrating that HLA-G participates in protecting CLL cells from NK-mediated killing and may thus contribute to their immune escape in vivo.
Assuntos
Antígenos HLA/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Células Matadoras Naturais/imunologia , Leucemia Linfocítica Crônica de Células B/imunologia , Mieloma Múltiplo/imunologia , Evasão Tumoral , Antígenos de Neoplasias , Citotoxicidade Imunológica , Antígenos HLA/análise , Antígenos HLA/genética , Antígenos HLA-G , Antígenos de Histocompatibilidade Classe I/análise , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Vigilância Imunológica , RNA Neoplásico/análiseRESUMO
In the UK 50% of primary care physicians are using electronic medical records in real time during the consultation. Some have given up using manual records at all. This paper describes the reasons they have implemented electronic medical records for progress notes during a consultation and the way such records improve the care given to individual patients. The essence of the argument is that doctors make decisions whilst they are with the patient. It is therefore essential that any assistance the computer can offer is available during every consultation.
Assuntos
Tomada de Decisões Assistida por Computador , Medicina de Família e Comunidade , Sistemas Computadorizados de Registros Médicos , Sistemas On-Line , Humanos , Sistemas Computadorizados de Registros Médicos/estatística & dados numéricos , Qualidade da Assistência à Saúde , Reino UnidoRESUMO
This paper considers the lessons learnt during the development of the electronic medical record for patient care. It is not a definitive history of medical records but an assessment of what has been learnt, what has to be learnt and how we can move forward. It considers the needs for structured intelligent records that help in individual patient care, the need to provide functionality that fits with the requirements of the clinician-patient interaction and the need to take into account the human factors that affect clinician's uptake of such systems. It outlines the issues of free form input as opposed to controlled input that have to be resolved.
Assuntos
Sistemas Computadorizados de Registros Médicos , Atitude do Pessoal de Saúde , Previsões , Humanos , Sistemas Computadorizados de Registros Médicos/tendências , Registros Médicos Orientados a ProblemasRESUMO
Treatment of microglia isolated from adult rat brain with interferon-gamma (IFN-gamma) at a concentration of 1 U/ml resulted in enhanced expression of Fc receptors and major histocompatibility complex (MHC) antigens and increased production of superoxide anions. Neonatal microglia and peritoneal macrophages, isolated and cultured in the same manner, displayed functional properties very similar to those of adult microglia, indicating a common origin for different macrophage populations. The Fc binding capacity of microglia was found to be significantly greater than that of peritoneal cells, thus underlining the potential role of microglia in immune-mediated demyelination.
Assuntos
Encéfalo/imunologia , Antígenos de Histocompatibilidade/análise , Interferon gama/farmacologia , Neuroglia/imunologia , Receptores Fc/análise , Superóxidos/metabolismo , Animais , Encéfalo/citologia , Separação Celular , Feminino , Macrófagos/imunologia , Masculino , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Ratos , Ratos Endogâmicos , Proteínas RecombinantesRESUMO
A solid phase approach has been used to synthesize a large branched disulphide peptide from IgG Fc, Ac-F-C*-A-K-V-N-N-K-D-L-P-A-P-I-E-K(Ac-E-L-L-G-G-P-S-V-F)-C*-I-NH2. This peptide combines the lower hinge region of IgG and a proximal beta-hairpin loop, both implicated in binding to Fc gammaRI. Solid phase Tl(tfa)3 cyclization of the linear branched peptide resulted in a poor yield of cyclic hinge-loop peptide (11%) most likely due to steric hindrance caused by the branch. However, if addition of the branch was preceded by solid phase Tl(tfa)3 cyclization of the loop, the yield was excellent at 75%. Cyclic hinge-loop peptide was active in displacing IgG2a from Fc gammaRI expressed on monocyte cell lines with an IC50 of 40 microM, whereas the linear form of this peptide was inactive. The Fc hinge-loop peptide demonstrates the potential for a non-mAb high affinity, immunomodulatory ligand for Fc gammaRI.