RESUMO
Teamwork in healthcare has been analysed extensively in the literature, mainly in acute healthcare settings such as the operating room, emergency room, and intensive care unit, with limited evidence related to diagnostic and interventional radiology. Multiple factors that affect teamwork in different domains have been described, such as communication, hierarchy, and distractions. Teamwork is an important patient safety, job satisfaction and patient outcome determinant, with interprofessional and interdisciplinary healthcare education playing a relevant role in the different domains affecting team performance. The aim of this article is to review the literature to describe domains and specific factors that influence teamwork in diagnostic and interventional radiology practice. This is of particular interest for radiologist involved in quality improvement and/or patient safety initiatives development and implementation. The review will conclude with a summary table highlighting the most important factors that, according to the authors, appear relevant to the radiology practice.
Assuntos
Segurança do Paciente , Melhoria de Qualidade , Humanos , Comunicação , Atitude do Pessoal de Saúde , Radiologia IntervencionistaRESUMO
BACKGROUND: The electronic Survey of Anxiety and Information for Dentists (eSAID) allows children to tell dentists about their feelings and coping preferences. It is a computer "quiz" with 26 questions and free-text responses that produces a report for the children that they can then hand to their dentist. This is the first study to report the use of eSAID in a hospital paediatric dental clinic. METHODS: This was a randomized controlled trial to evaluate whether children thought that eSAID benefitted them, made them less anxious, and improved cooperation and their treatment satisfaction. Fifty-one children aged 8-13 years were randomized to complete either eSAID or a control version in the waiting room before their scheduled dental appointment. The study group had a 26-item questionnaire; the control had only two items. Both groups scored their anxiety on a 7-point anxiety scale at the start and again at the end of the quiz. All subjects handed the resultant eSAID report as a printout to their dentist. Dental treatment proceeded as planned. After treatment, each child reported how they thought the eSAID quiz had benefitted them by scoring on a 10 cm Visual Analogue Scale and their satisfaction on the Modified Treatment Evaluation Inventory. The operating dentists scored the children's cooperation using a 10 cm Visual Analogue Scale. RESULTS: Overall, the baseline anxiety levels were low (study: mean 1.2; control: mean 1.5). The study group's post-survey anxiety reduced by 0.4, whereas controls' increased by 0.2; this difference is statistically significant (p = .04). However, it made no difference to the children's self-reported benefit (p = .30), satisfaction (p > .05), or cooperation (p = .34). CONCLUSIONS: eSAID reduced pre-treatment anxiety but made no difference to children's perceived benefit, satisfaction, or cooperation. Future study should include known anxious children.
Assuntos
Atitude Frente a Saúde , Ansiedade ao Tratamento Odontológico/prevenção & controle , Assistência Odontológica para Crianças/organização & administração , Adaptação Psicológica , Adolescente , Criança , Comunicação , Ansiedade ao Tratamento Odontológico/psicologia , Assistência Odontológica para Crianças/métodos , Assistência Odontológica para Crianças/psicologia , Relações Dentista-Paciente , Feminino , Humanos , Londres , Masculino , Satisfação do Paciente , Assistência Centrada no Paciente/organização & administração , Inquéritos e Questionários , Terapia Assistida por Computador/métodosRESUMO
BACKGROUND AND OBJECTIVES: Suicide rates among dentists and a perceived elevated risk for suicide have been debated in the academic literature. It has filtered into the public psyche that dentists have the highest suicide rate of any occupation. The present review seeks support for both protagonist and antagonist positions from multidisciplinary perspectives. Contemporary risk factors and strategies for intervention and the prevention of suicide in dentistry are explored. METHODS: An online database search for articles and reports, with selected target words, was conducted for peer reviewed publications on suicide in the dental profession, and for factors contributing to dentist suicide. Review guidelines from the American Psychological Association were used to clarify concepts, identify where most work was focussed, and to explore the superiority of any approach to the emotive topic over another. RESULTS: Findings suggest the dominant belief that dentists have an elevated risk of suicide may be historically, but not currently, accurate. Although dentists' suicide is trending down, diversity in methodology means no current consensus is possible. Factors found to be influencing dentists' suicide ranged from known occupational stressors, to toxins and substance abuse, and untreated mental health problems. CONCLUSION: The contemporary position in New Zealand shows dentists per sé are not more likely than other health professionals to commit suicide although they may have been in the past. Dentists should be aware of individual susceptibility to burnout and mental health problems. Future directions are outlined to address this including peer intervention, and programmes available for dentists to cope better with risks leading to suicide.
Assuntos
Odontólogos/psicologia , Estresse Psicológico/psicologia , Suicídio/estatística & dados numéricos , Adaptação Psicológica , Humanos , Fatores de RiscoRESUMO
BACKGROUND AND OBJECTIVES: A review of psychology, dental, and medical literature aimed to identify key variables for an ideal dentist-patient relationship. When empathy surfaced as the key positive variable, a further aim, which became the aim of this paper, was to explore how empathy could be intentionally applied. METHODS: An online database search, limited to judgementally selected target-words, was conducted for peer-reviewed papers on the dentist-patient relationship. Review guidelines from the American Psychological Association were used to clarify concepts, identify where most work was focussed, and to explore the superiority of any approach to the topic, over another. RESULTS: The distinction between instrumental (information) and affective (emotional) communication was important with empathy being the key variable. Empathy was seen clearly to facilitate improved communication and the experience of dentistry for patient and practitioner alike. Empathy was positively associated with negotiated treatment plans, treatment adherence, increased patient satisfaction, and reduced dental anxiety. However, the concept of empathy was rarely operationally defined, or empirically measured. At best it was a scale score or a theme in qualitative data analysis. As such, applied empathy is discussed as a perceived concept. Dental school curricula and patient request forms were found to have the greatest potential to train dentists to convey empathy, and for patients to perceive empathy. CONCLUSION: Future directions are proposed, to apply empathy in the dentist-patient relationship through an integrated model of patient-centred communication.
Assuntos
Relações Dentista-Paciente , Empatia , Atitude do Pessoal de Saúde , Comunicação , HumanosRESUMO
BACKGROUND: Children's unhappy visits to the dentist can negatively impact lifelong oral health. A possible intervention is to enhance empathy in the child patient-dental practitioner relationship through communication. The present paper presents a new instrument, the Survey of Anxiety and Information for Dentists (SAID), which targets children's dental anxiety, coping preferences and dental neglect, and offers children a change to request information and engage in treatment planning. METHOD: Five children's focus groups pilot tested the content, wording and response format of a prototype patient request form, the SAID. Participants were 34 10- to 13-year-old children who individually completed the form then discussed it item by item in their small groups. RESULTS: Children had no difficulty completing most items. They identified ambiguities, and items that were meaningless to them, and proposed a new item asking the dentist about their job. Children were polarized over the response format, but they were emphatic about passing the form directly to the dentist, and not to a receptionist or assistant, stressing the importance of having a conversation with their dentist. CONCLUSIONS: Before the pilot, dentists had expressed concerns about the potential for words in the SAID-provoking negative feelings. Children, however, wanted and needed facts, so requested that dentists use plain language, not euphemisms, to describe problems and treatment options. We report their selected practical suggestions. SAID-informed negotiated care may promote more patient cooperation and satisfaction at appointments, and more attention to oral hygiene between appointments.
Assuntos
Comunicação , Ansiedade ao Tratamento Odontológico/prevenção & controle , Assistência Odontológica para Crianças/organização & administração , Melhoria de Qualidade , Adolescente , Criança , Pré-Escolar , Ansiedade ao Tratamento Odontológico/psicologia , Relações Dentista-Paciente , Feminino , Humanos , Masculino , Saúde Bucal , Higiene Bucal/normas , Projetos PilotoRESUMO
Circulating cortisol, corticosteroid-binding globulin, and sex hormone-binding globulin were measured retrospectively in plasma samples following the oral glucose tolerance test in 20 spinal cord-injured men and 20 able-bodied controls. Plasma-free cortisol responses attenuated more rapidly in the able-bodied men, compared to spinal cord-injured subjects, due to significant rise in circulating corticosteroid-binding globulin whereas changes in total plasma cortisol were similar in both groups. The changes in plasma-free cortisol in both groups paralleled changes in insulin and glucose and show that spinal cord-injured men had heightened exposure to free cortisol during this dynamic test. This raises the possibility that the mechanism of abdominal obesity and the propensity towards insulin resistance in spinal cord-injured men could be subtly mediated by perturbations in free cortisol. There were no significant changes in plasma sex hormone-binding globulin in either group.
Assuntos
Hidrocortisona/sangue , Globulina de Ligação a Hormônio Sexual/metabolismo , Traumatismos da Medula Espinal/metabolismo , Transcortina/metabolismo , Adolescente , Adulto , Glicemia , Estudos de Casos e Controles , Teste de Tolerância a Glucose , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Traumatismos da Medula Espinal/sangue , Adulto JovemRESUMO
We present the case of a 33-year-old man with right-sided facial pain. Clinical examination revealed an isolated mass attached to the right inferior turbinate. This was confirmed with computed tomography. Excision was achieved endoscopically and histology revealed an angioleiomyoma. Full symptomatic relief was achieved after surgical excision. Less than 1% of angioleiomyoma lesions are found within the sinonasal cavity. We describe the first documented presentation of angioleiomyoma as a cause of isolated, unilateral facial pain; a very common presentation to the otorhinolaryngology clinic. We promote consideration of angioleiomyoma as a different diagnosis in the presence of facial pain and a unilateral sinonasal lesion. Endoscopic resection provides complete symptomatic resolution.
Assuntos
Angiomioma/diagnóstico , Dor Facial/etiologia , Obstrução Nasal/etiologia , Neoplasias Nasais/diagnóstico , Adulto , Angiomioma/complicações , Angiomioma/cirurgia , Biópsia , Endoscopia , Dor Facial/cirurgia , Humanos , Masculino , Obstrução Nasal/diagnóstico por imagem , Obstrução Nasal/cirurgia , Neoplasias Nasais/complicações , Neoplasias Nasais/cirurgia , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Conchas Nasais/diagnóstico por imagem , Conchas Nasais/patologiaRESUMO
Stress hormones significantly impact dendritic cell (DC) activation and function, typically in a suppressive fashion. However, a social stressor termed social disruption (SDR) has been shown to induce an increase in inflammatory responses and a state of glucocorticoid resistance in splenic CD11b+ monocytes. These experiments were designed to determine the effects of SDR on DC activation, Toll-like receptor-induced cytokine secretion, and glucocorticoid sensitivity. Compared to cells obtained from control animals, splenic DCs from SDR mice displayed increased levels of MHC I, CD80, and CD44, indicative of an activated phenotype. In addition, DCs from SDR mice produced comparatively higher TNF-alpha, IL-6, and IL-10 in response to in vitro stimulation with LPS and CpG DNA. Increased amounts of TNF-alpha and IL-6 were also evident in SDR DC cultures stimulated with poly(I:C). Furthermore, as shown previously in CD11b+ monocytes, the CD11c+ DCs obtained from SDR mice were glucocorticoid resistant. Taken together, the data suggest that social stress, in the absence of any immune challenge, activates DCs, increases DC cytokine secretion in response to Toll-specific stimuli and renders DCs glucocorticoid resistant.
Assuntos
Células Dendríticas/imunologia , Dominação-Subordinação , Glucocorticoides/metabolismo , Baço/citologia , Estresse Psicológico/imunologia , Receptores Toll-Like/metabolismo , Análise de Variância , Animais , Antígeno B7-1/metabolismo , Antígeno CD11b/metabolismo , Antígeno CD11c/metabolismo , Células Cultivadas , Citocinas/metabolismo , Citometria de Fluxo , Genes MHC Classe I/fisiologia , Glucocorticoides/farmacologia , Receptores de Hialuronatos/metabolismo , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Lipopolissacarídeos/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/imunologia , Monócitos/metabolismo , Baço/imunologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
After a strong earthquake, the possibility of the occurrence of either significant aftershocks or an even stronger mainshock is a continuing hazard that threatens the resumption of critical services and reoccupation of essential but partially damaged structures. A stochastic parametric model allows determination of probabilities for aftershocks and larger mainshocks during intervals following the mainshock. The probabilities depend strongly on the model parameters, which are estimated with Bayesian statistics from both the ongoing aftershock sequence and from a suite of historic California aftershock sequences. Probabilities for damaging aftershocks and greater mainshocks are typically well-constrained after the first day of the sequence, with accuracy increasing with time.
RESUMO
The Whittier Narrows earthquake sequence (local magnitude, M(L) = 5.9), which caused over $358-million damage, indicates that assessments of earthquake hazards in the Los Angeles metropolitan area may be underestimated. The sequence ruptured a previously unidentified thrust fault that may be part of a large system of thrust faults that extends across the entire east-west length of the northern margin of the Los Angeles basin. Peak horizontal accelerations from the main shock, which were measured at ground level and in structures, were as high as 0.6g (where g is the acceleration of gravity at sea level) within 50 kilometers of the epicenter. The distribution of the modified Mercalli intensity VII reflects a broad north-south elongated zone of damage that is approximately centered on the main shock epicenter.
RESUMO
Listeria monocytogenes is a food-borne pathogen with a high mortality rate that has also emerged as a paradigm for intracellular parasitism. We present and compare the genome sequences of L. monocytogenes (2,944,528 base pairs) and a nonpathogenic species, L. innocua (3,011,209 base pairs). We found a large number of predicted genes encoding surface and secreted proteins, transporters, and transcriptional regulators, consistent with the ability of both species to adapt to diverse environments. The presence of 270 L. monocytogenes and 149 L. innocua strain-specific genes (clustered in 100 and 63 islets, respectively) suggests that virulence in Listeria results from multiple gene acquisition and deletion events.
Assuntos
Proteínas de Bactérias/genética , Genoma Bacteriano , Listeria monocytogenes/genética , Listeria/genética , Adaptação Fisiológica , Motivos de Aminoácidos , Bacillus subtilis/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/fisiologia , Composição de Bases , Proteínas de Transporte/química , Proteínas de Transporte/genética , Cromossomos Bacterianos/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Transferência Genética Horizontal , Genes Bacterianos , Genômica , Listeria/química , Listeria/fisiologia , Listeria monocytogenes/química , Listeria monocytogenes/patogenicidade , Listeria monocytogenes/fisiologia , Proteínas de Membrana/química , Proteínas de Membrana/genética , Análise de Sequência de DNA , Staphylococcus aureus/genética , Fatores de Transcrição/química , Fatores de Transcrição/genética , Virulência/genéticaRESUMO
Competency at graduation, in a variety of physical and attitudinal skills, is an essential outcome measure for courses training veterinary surgeons. The approach adopted by the Royal Veterinary College, London, to identify and define the expected skill competencies required of our veterinary undergraduates by the time of graduation is described. In addition, we demonstrate how this skill set was built into a framework that was aligned with other student learning objectives. This two-year project resulted in the publication of a day-one skills handbook, which was introduced to the college staff and students in 2007.
Assuntos
Competência Clínica , Currículo/normas , Educação em Veterinária/normas , Medicina Veterinária/normas , Animais , Medicina Baseada em Evidências , Humanos , Aprendizagem Baseada em ProblemasRESUMO
The prospect of "curing" spinal cord injury using stem cell therapy is one of the significant goals of many stem cell researchers. In this communication we consider some of the physiological implications of successful in vivo spinal cord repair and the ethical issues this potential revolutionary therapy will raise.
Assuntos
Traumatismos da Medula Espinal/terapia , Transplante de Células-Tronco/ética , Humanos , Regeneração Nervosa/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Nervos Espinhais/fisiologia , Transplante de Células-Tronco/tendênciasRESUMO
The Asian Tsunami killed more than 130,000 people and made 400,000 homeless in Aceh, an area in Indonesia already affected by over thirty years of conflict. This paper examines an approach taken by an International Non-Governmental Organisation (INGO) to address emergency mental health and psychosocial needs in an integrated way, by providing a continuum of care incorporating psychosocial support for the wider community and clinical services for the more severely affected. The model included outreach to the indigenous system. Psychosocial activities were developed in partnership with the local communities. Community-based clinical mental health services were established by identifying and building locally-based capacity at the primary health care level, and potentially sustainable services were established in collaboration with the Ministry of Health. By December 2005, four hundred and eighty three patients had been seen. More than one third suffered from serious mental disorders that predated the Tsunami. Thus, crisis provided an opportunity to address longstanding community mental health needs. The lessons learned from this approach are also discussed.
Assuntos
Serviços Comunitários de Saúde Mental/organização & administração , Continuidade da Assistência ao Paciente/normas , Desastres , Transtornos Mentais/terapia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Serviços Comunitários de Saúde Mental/provisão & distribuição , Relações Comunidade-Instituição , Continuidade da Assistência ao Paciente/tendências , Feminino , Pesar , Humanos , Indonésia/epidemiologia , Lactente , Recém-Nascido , Agências Internacionais , Masculino , Transtornos Mentais/epidemiologia , Transtornos Mentais/psicologia , Pessoa de Meia-Idade , Apoio Social , Instituições Filantrópicas de SaúdeRESUMO
The inhibition of DNA synthesis in triciribine (TCN)-treated L1210 cells was shown to involve two mechanisms, with different concentration dependence. (a) Initiation of new replicons and possibly of Okazaki fragments was inhibited when the cells were treated with 0.1 microM TCN. The inhibition of replicon initiation was shown by the rate of alkaline elution of [3H]DNA from 15-min-[3H]thymidine-labeled cells being slower if the cells had been pretreated with TCN, indicating that the average size of actively replicating DNA strands was increased. (b) At 1 microM TCN elongation of previously initiated DNA chains was also inhibited. This conclusion was suggested by the decrease in the rate of alkaline elution of [3H]DNA, during postlabeling incubation, being less if TCN was included in the medium. The mechanism of inhibition of DNA synthesis by TCN was shown not to involve DNA strand breakage or cross-linking, inhibition of polyamine biosynthesis, inhibition of purine de novo biosynthesis, inhibition of DNA polymerase alpha or DNA primase, or inhibition of ligation of Okazaki fragments. The effects of TCN on the incorporation of [3H]thymidine into Okazaki fragments and higher molecular weight DNA suggested the possibilities of inhibition of Okazaki fragment initiation and/or DNA polymerase delta.
Assuntos
Antineoplásicos/farmacologia , Replicação do DNA/efeitos dos fármacos , Ribonucleosídeos/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos , Animais , DNA Polimerase I/metabolismo , DNA Primase , DNA de Neoplasias/antagonistas & inibidores , DNA de Neoplasias/biossíntese , DNA de Neoplasias/isolamento & purificação , Cinética , Leucemia L1210/metabolismo , Camundongos , Putrescina/metabolismo , RNA Nucleotidiltransferases/metabolismo , Espermidina/metabolismo , Espermina/metabolismo , Timidina/metabolismo , Células Tumorais Cultivadas/metabolismoRESUMO
The microplate version of the leukocyte adherence inhibition (LAI) test was evaluated in murine and human studies. It was used in parallel with the microcytotoxicity assay, lymphotoxin assay, leukocyte migration inhibition, and lymphocyte stimulation tests in a transplantable murine tumor model, and it compared favorably with these established techniques for the detection of cellular immunity. The LAI test detected both primary and secondary anamnestic responses in Bacillus Calmette-Guérin-primed mice, and it displayed sensitivity to host humoral factors comparable to that seen with other tests. The LAI phenomenon was shown to be mediated by a soluble supernatant factor liberated by antigen-exposed immune leukocytes in the mouse and by concanavalin A-stimulated human leukocytes. In the mouse, deliberate depletion of T-cells ablates LAI reactivity in cells taken at the peak of a primary response; however, immune serum "arms" non-thymus-dependent cells taken from unimmunized hosts. In the mouse, the results of LAI tests correlate with other established techniques, when purified protein derivative reactivity was assessed in spleen cells from Bacillus Calmette-Guérin-immunized mice. Comparable correlation is not found when reactivity to this antigen is assessed in human peripheral blood samples from unimmunized donors.
Assuntos
Imunidade Celular , Técnicas Imunológicas , Teste de Inibição de Aderência Leucocítica , Neoplasias Experimentais/imunologia , Animais , Anticorpos Antineoplásicos , Antígenos de Neoplasias/administração & dosagem , Ligação Competitiva , Humanos , Ativação Linfocitária , Melanoma/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Baço/imunologiaRESUMO
Comparing 14 women with and 55 women without endometriosis, the authors found no significant differences in the prevalence of affective disorder. They discuss the discrepancy between their finding and Lewis et al.'s finding of an association between affective disorder and endometriosis.
Assuntos
Transtorno Depressivo/complicações , Endometriose/complicações , Adulto , Estudos Transversais , Transtorno Depressivo/epidemiologia , Transtorno Depressivo/genética , Humanos , Masculino , Escalas de Graduação PsiquiátricaRESUMO
The adhesion of tumour cells to the hyaluronan (HA) pericellular coat of mesothelial cells is an important step in the peritoneal spread of ovarian cancer. Previously, we have shown that the cell surface molecule CD44 is involved in this process. Paradoxically, the degree of adhesion does not appear to be related to the amount of CD44 expressed. In order to explain this observation we have examined the in vitro adhesion to HA of four high CD44-expressing ovarian cancer lines in relation to their CD44 spliced variant content and the CD44 glycosylation. Adhesion was measured in multiwell plates coated with different concentrations of HA in order to determine both the avidity and the maximum adhesion. Two lines had high adhesion and two lines had low adhesion. The avidity for HA was different for each line, but in all cases this could be totally blocked by treatment with an anti-CD44 antibody. The standard form of CD44 was the major species detected by RT/PCR in all lines and spliced variants were present in low amounts. Neuraminidase treatment increased the adhesion of the 'low-adhesion' lines at all HA coating concentrations; but only substantially increased the adhesion of the 'high-adhesion' lines at the lower HA coating concentrations. Tunicamycin treatment decreased the adhesion of the 'high-adhesion lines' at all HA coating concentrations and only substantially decreased the adhesion of one of the 'low-adhesion' lines when the plates were coated with a low concentration of HA. The adhesion of the remaining 'low-adhesion' line was slightly increased after tunicamycin treatment. It is concluded that glycosylation and not spliced variant content of CD44 affects the adhesive properties of ovarian tumour cells. This conclusion may have important consequences for developing new therapies in ovarian cancer.
Assuntos
Carcinoma Endometrioide/patologia , Moléculas de Adesão Celular/fisiologia , Adesão Celular , Cistadenocarcinoma Papilar/patologia , Receptores de Hialuronatos/fisiologia , Ácido Hialurônico/fisiologia , Glicoproteínas de Membrana/fisiologia , Metástase Neoplásica/fisiopatologia , Proteínas de Neoplasias/fisiologia , Neoplasias Ovarianas/patologia , Processamento de Proteína Pós-Traducional , Carcinoma Endometrioide/metabolismo , Moléculas de Adesão Celular/biossíntese , Cistadenocarcinoma Papilar/metabolismo , Feminino , Glicosilação/efeitos dos fármacos , Humanos , Receptores de Hialuronatos/biossíntese , Glicoproteínas de Membrana/biossíntese , Ácido N-Acetilneuramínico/química , Proteínas de Neoplasias/biossíntese , Neuraminidase/farmacologia , Neoplasias Ovarianas/metabolismo , Neoplasias Peritoneais/secundário , Ligação Proteica , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Células Tumorais Cultivadas , Tunicamicina/farmacologiaRESUMO
Our previous studies have suggested that the interaction between hyaluronic acid (HA) on peritoneal mesothelial cells and the membrane adhesion molecule, CD44, on ovarian tumour cells could be important in ovarian cancer metastasis. In order to study this further, adhesion of six ovarian tumour lines to HA coated on to a plastic surface was investigated. Four lines bound to the HA coat and two lines did not. The adhesive lines were those that expressed high amounts of CD44, but the degree of adhesion was not closely correlated with CD44 expression. The results suggested that different tumour lines had different affinities for HA. Treatment of the HA coat with hyaluronidase substantially reduced adhesion. Adhesion was also partially reduced if the tumour cells were preincubated with either soluble HA, or anti-CD44 antibodies directed against the HA binding region. An antibody against a non-HA binding region only slightly blocked adhesion at high antibody concentrations. Only the CD44H isoform was detected by immunoprecipitation on the tumour cells. These results suggest that ovarian tumour cells can attach to immobilised HA via CD44H on the cell membrane.
Assuntos
Receptores de Hialuronatos/biossíntese , Ácido Hialurônico/metabolismo , Neoplasias Ovarianas/metabolismo , Neoplasias Peritoneais/secundário , Anticorpos/farmacologia , Autorradiografia , Adesão Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Relação Dose-Resposta a Droga , Eletroforese/métodos , Feminino , Fluorometria/métodos , Humanos , Receptores de Hialuronatos/imunologia , Ácido Hialurônico/farmacologia , Hialuronoglucosaminidase/farmacologia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Células Tumorais CultivadasRESUMO
The adhesion to mesothelial monolayers of eight cultured ovarian tumour cell lines was studied in multiwell plates as a model for some of the interactions of ovarian cancer in the peritoneal cavity. When only the upper half of the conditioned medium (CM) from a confluent mesothelial cell culture was aspirated, the adhesion of the tumour cells was low (3.5%-36%). When the medium was removed completely the adhesion increased. The tumour cell lines showing the greatest enhancement of adhesion were those which had previously been shown to express the highest amounts of CD44. By adding erythrocyte suspensions to mesothelial cells it was shown that there was a pericellular coat around the mesothelial cells that could be destroyed by aspirating the medium, or by treating the medium with hyaluronidase (Hase). Treatment of the CM with Hase also considerably increased tumour cell adhesion. Furthermore, CM was shown to contain high amounts of hyaluronic acid (HA). HA blocked adhesion in the absence of CM, but the effect was not as large as that produced by the pericellular coat. It is proposed that pericellular HA produced by mesothelial cells has an important role in the invasion of ovarian tumour cells in the peritoneal cavity.