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INTRODUCTION: Despite advances in diagnosis and management, the outcomes for both lung cancer and idiopathic pulmonary fibrosis (IPF) are still unfavourable. The pathophysiology and outcomes for patients with concomitant lung cancer and IPF remains unclear. METHODOLOGY: A retrospective analysis was performed of all patients presenting with concomitant IPF and lung cancer to our centre over a 3-year period. Patients with connective tissue disease, asbestos exposure, sarcoidosis, previous thoracic radiation, radiological evidence of fibrosis but no histological confirmation of lung cancer, or the use of medications known to cause pulmonary fibrosis were excluded. We describe clinical, radiological and pathological characteristics of this group. We also report the response to standardized lung cancer therapy in this cohort. RESULTS: Of 637 lung cancer patients, 34 were identified with concomitant IPF (5.3 %) and all were smokers. 85 % had non-small cell lung cancer, 41 % were squamous cell cancers. The majority of tumours were located in the lower lobes, peripheral and present in an area of honeycombing. Despite the fact that approximately 2/3rds of the patients had localised or locally advanced lung cancer, the outcome of therapy for lung cancer was extremely poor regardless of tumour stage or severity of IPF. CONCLUSIONS: At our centre, 1/20 patients with lung cancer have concomitant IPF. The majority of these tumours are small in size, peripheral in location and squamous cell carcinoma; in an area of honey combing. The outcome for concomitant lung cancer and IPF regardless of stage or therapy is poor.
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Carcinoma de Pulmón de Células no Pequeñas/complicaciones , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Carcinoma de Células Escamosas/complicaciones , Carcinoma de Células Escamosas/diagnóstico , Fibrosis Pulmonar Idiopática/complicaciones , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/diagnóstico , Pulmón/diagnóstico por imagen , Pulmón/patología , Anciano , Biopsia , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/terapia , Carcinoma de Células Escamosas/diagnóstico por imagen , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/terapia , Femenino , Humanos , Fibrosis Pulmonar Idiopática/diagnóstico , Fibrosis Pulmonar Idiopática/mortalidad , Irlanda , Estimación de Kaplan-Meier , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/terapia , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Fumar/efectos adversos , Factores de Tiempo , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Carga TumoralRESUMEN
OBJECTIVES: The aim of this study was to evaluate inhaler technique and symptom control in patients with poorly controlled asthma at baseline and at follow-up in a dedicated asthma clinic in a tertiary hospital. We also investigated the impact of asthma on these patients' quality of life. METHODS: Patients referred to a newly established asthma clinic in Cork University Hospital were prospectively recruited over a 6-month period. Their inhaler technique was assessed by a pulmonary nurse specialist using a validated scoring system. They received instruction on inhaler usage when scores were suboptimal. Patients completed a validated asthma control questionnaire (ACQ) and asthma quality of life questionnaire (AQLQ). At follow-up 3-4 months later, the inhaler technique was reassessed and the ACQ questionnaire repeated. RESULTS: Forty-six patients were recruited (female = 74%), and 40/46 were followed up. Mean [SD] FEV1 % predicted at baseline = 76.5% [21.5]. About 63% of the patients were classified as incorrectly using their inhaler at their initial assessment. This decreased to 20% at follow-up, indicating an overall significant improvement in inhaler usage post-training (p = 0.003). ACQ scores improved significantly from median [interquartile range] 2.70 [1.66] to 2.00 [1.90] (p = 0.002). Baseline measurement indicated that patients' quality of life was moderately affected by asthma, with a median AQLQ score of 4.75 [1.97]. CONCLUSION: This study demonstrates the importance of educating and formally assessing inhaler technique in patients with asthma as a part of their ongoing clinical review.
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Antiasmáticos/administración & dosificación , Asma/tratamiento farmacológico , Nebulizadores y Vaporizadores/estadística & datos numéricos , Cooperación del Paciente/estadística & datos numéricos , Educación del Paciente como Asunto/métodos , Administración por Inhalación , Adulto , Atención Ambulatoria/métodos , Instituciones de Atención Ambulatoria , Asma/diagnóstico , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Irlanda , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Control de Calidad , Medición de Riesgo , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND: The diagnostic accuracy of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for the diagnosis of lymphoma in patients with mediastinal lymphadenopathy is not well defined. METHODS: A retrospective review was performed of all patients with mediastinal lymphadenopathy referred for EBUS-TBNA between August 2005 and December 2006 in whom lymphoma was suspected based on prior history or clinical presentation. Mediastinal biopsy specimens were taken using a linear array ultrasonic bronchoscope (Olympus XBF-UC 160F) and a 22-gauge cytology needle (NA-202C Olympus) with on-site cytopathological support. The EBUS-TBNA result was compared with a reference standard of pathological tissue diagnosis or a composite of > or =6 months of clinical follow-up with radiographic imaging. RESULTS: Of 236 patients who underwent EBUS-TBNA, 25 were eligible for inclusion. Indications for EBUS-TBNA were suspected mediastinal recurrence of lymphoma (n = 13) and mediastinal lymphadenopathy of unknown cause (n = 12). Adequate lymph node sampling was accomplished in 24/25 patients (96%); there were no complications. EBUS-TBNA identified lymphoma in 10 patients and benign disease in 14 patients. There was one false negative EBUS-TBNA for lymphoma (lymphoma prevalence 11/25 (44%)). Follow-up over a median of 10.5 months (range 1-19) confirmed stable or regressive lymphadenopathy in all 14 patients without a lymphoma diagnosis, consistent with a benign diagnosis. Overall, EBUS-TBNA had a sensitivity of 90.9%, specificity of 100%, positive predictive value of 100% and negative predictive value of 92.9% for the diagnosis of lymphoma. CONCLUSIONS: EBUS-TBNA is an accurate, safe and useful tool in the investigation of suspected lymphoma with isolated mediastinal adenopathy, and may diminish the need for more invasive procedures such as mediastinoscopy.
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Neoplasias Pulmonares/patología , Linfoma/patología , Adulto , Anciano , Biopsia con Aguja/métodos , Broncoscopía/métodos , Femenino , Humanos , Masculino , Mediastino/patología , Persona de Mediana Edad , Estudios Retrospectivos , Ultrasonografía Intervencional/métodosRESUMEN
Brachytherapy is a modality of treatment available for lung cancer with tracheal involvement. Correct positioning of the brachytherapy catheter is vital to the optimisation of treatment effect and reduction of complications. Normal airway anatomy and tumour location can make this positioning difficult. The current study presents the case of a 65-yr-old male with invasive tracheal squamous cell carcinoma of the anterior main carina involving the proximal left and right bronchus. The patient was successfully treated with brachytherapy using a novel modified airway stent with a traversing suture for positioning and stabilising the brachytherapy catheters and maximisation of the radiation effect. This simple yet innovative modification of readily available bronchoscopic equipment permits approximation and fixation of a brachytherapy catheter to any part of the proximal airway. Further analysis of this technique, including a prospective controlled trial, is planned.
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Braquiterapia/instrumentación , Neoplasias de Células Escamosas/radioterapia , Stents , Neoplasias de la Tráquea/radioterapia , Anciano , Braquiterapia/métodos , Broncoscopios , Humanos , MasculinoRESUMEN
BACKGROUND: Community acquired pneumonia is one of the most common infections for which antibiotics are prescribed in Australia. METHODS: We audited empiric antibiotic prescribing for 392 adults with community-acquired pneumonia. RESULTS: Only 61.9% of patients received empiric antibiotic coverage for both typical and atypical pathogens. Of those who required intensive care unit management, 34.6% did not receive antibiotic cover for atypical pneumonia pathogens within the first 24 h. Approximately 21.9% of patients reporting antibiotic allergies were given antibiotics to which they had a documented allergy. CONCLUSION: Efforts to improve prescribing practices could be focused towards identifying patients with severe illness early and improving recognition of documented allergies.
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Antiinfecciosos/uso terapéutico , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Neumonía/tratamiento farmacológico , Pautas de la Práctica en Medicina , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Infecciones Comunitarias Adquiridas/microbiología , Servicio de Urgencia en Hospital , Femenino , Humanos , Masculino , Auditoría Médica , Persona de Mediana Edad , Neumonía/microbiologíaRESUMEN
SETTING: The Southwest of Ireland (Counties Cork and Kerry) 1987-2000, average population 549,500. OBJECTIVE: Nontuberculous mycobacteria (NTM) cause significant morbidity worldwide and the study of epidemiology and characteristics helps in their prevention and treatment. This study was performed to determine the incidence of NTM disease in comparison to Mycobacterium tuberculosis (M. tuberculosis) and Mycobacterium bovis (M. bovis) in Southwest Ireland, over the above time period. DESIGN: A retrospective study was carried out in all human isolates of NTM, M. tuberculosis and M. bovis between 1987 and 2000, in the Southwest Region of Ireland. RESULTS: The mean incidence of NTM (0.4/100,000 population) has risen since 1995, principally of pulmonary Mycobacterium avium intracellulare complex (MAC). The annual incidence of M. tuberculosis in humans over 14 years in the same region was 971/100,000 population with a significant reduction since 1994 and M. bovis remained constant at 0.5/100,000 population. CONCLUSION: The increasing incidence of disease causing NTM noted in Southwest Ireland reflects global data and is surmised to be due to an ageing population, increased incidence related to chronic fibrotic lung disease, and environmental mycobacterial factors.
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Infecciones por Mycobacterium/epidemiología , Adulto , Femenino , Humanos , Incidencia , Irlanda/epidemiología , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
Previous studies of setting expansion of gypsum-bonded investments have not examined how wax patterns expand with time. The purpose of this study was to provide a method of measuring wax patterns during the setting reaction. Ten MOD inlay wax patterns were invested individually in plastic casting rings and imaged at specific intervals on a stage on which both the rings and xeroradiographic cassettes were fixed. Distances between the axiogingival proximal walls, axiopulpal proximal walls, and axial walls were measured at each interval. Reproducibility of measurements of xeroradiographic images was about 0.3%. After setting, the wax was burned out, and the rings were cooled to room temperature and cast in a Bi-Sn alloy that did not shrink upon solidification. The castings were measured and the means compared with the means of xeroradiographic measurements. There was no significant difference between the expansion means of the axiogingival or axiopulpal dimensions measured by casting or xeroradiographically (p greater than 0.05, two-tailed t test). Significant differences (p less than 0.05) were seen between means of the axial expansion measured by castings and xeroradiographically, suggesting the formation of a void at the proviral walls of the wax patterns. All horizontal expansion occurred between two and 22 min from the start of mix.
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Revestimiento para Colado Dental , Ensayo de Materiales , XerorradiografíaRESUMEN
The Green Lane Hospital experience of patients presenting with cardiac damage as a result of chest trauma has been reviewed following the recent referral of a patient with tricuspid regurgitation due to trauma. A retrospective search of surgical records was made over the preceding 28 years which yielded a further nine patients. Our group has experienced a number of unusual causes of non-fatal cardiac trauma that have followed accidents. In nine out of ten cases closed chest injury resulted in damage to the heart. In some, diagnosis had been delayed for years. Echocardiography is a very useful diagnostic tool. Surgery was undertaken in all cases.
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Lesiones Cardíacas/etiología , Traumatismos Torácicos/complicaciones , Heridas no Penetrantes/complicaciones , Adolescente , Adulto , Niño , Errores Diagnósticos , Femenino , Lesiones Cardíacas/diagnóstico , Lesiones Cardíacas/cirugía , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo , Resultado del TratamientoRESUMEN
INTRODUCTION: The aim of this study was to identify radiological factors that may reduce false-positive results and increase diagnostic accuracy when staging the mediastinum of patients with non-small cell lung carcinoma (NSCLC). METHODS: This was a retrospective, interdisciplinary, per-node analysis study. We included patients with NSCLC and mediastinal nodes with an SUV max in the range of 2.5-4.0 on PET-CT. We hypothesized that the greatest number of false positive cases would occur in this cohort of patients. RESULTS: A total of 92 mediastinal lymph nodes were analyzed in 44 patients. Mediastinal disease (N2/N3) was histologically confirmed in 15 of 44 patients and in 34 of 92 lymph nodes; positive predictive value of 37% and false positive rate of 63%. Lymph node SUV max, tumor size, ratio of node SUV max to tumor SUV max (SUVn/SUVp), and ratio of node SUV max to node size (SUV n/SADn) were significantly higher in true positive cases. Using a threshold of 0.3 for SUV node/tumor and 3 for SUV node/size yielded sensitivities of 91% and 71% and specificities of 71% and 69% respectively for the detection of mediastinal disease. Using both ratios in combination resulted in a sensitivity of 65% and a specificity of 88%. Concurrent benign lung disease was observed significantly more frequently in false-positive cases. CONCLUSION: SUVn/SUVpt and SUVn/SADn may be complimentary to conventional visual interpretation and SUV max measurement in the assessment of mediastinal disease in patients with NSCLC.
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Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/secundario , Aumento de la Imagen/métodos , Neoplasias Pulmonares/patología , Mediastino/patología , Tomografía de Emisión de Positrones/métodos , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Reacciones Falso Positivas , Femenino , Fluorodesoxiglucosa F18 , Humanos , Ganglios Linfáticos/diagnóstico por imagen , Ganglios Linfáticos/patología , Metástasis Linfática , Masculino , Persona de Mediana Edad , Imagen Multimodal/métodos , Estadificación de Neoplasias , Variaciones Dependientes del Observador , Radiofármacos , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Several severity scores have been proposed to predict patient outcome and to guide initial management of patients with community acquired pneumonia (CAP). Most have been derived as predictors of mortality. A study was undertaken to compare the predictive value of these tools using different clinically meaningful outcomes as constructs for "severe pneumonia". METHODS: A prospective cohort study was performed of all patients presenting to the emergency department with an admission diagnosis of CAP from March 2003 to March 2004. Clinical and laboratory features at presentation were used to calculate severity scores using the pneumonia severity index (PSI), the revised American Thoracic Society score (rATS), and the British Thoracic Society (BTS) severity scores CURB, modified BTS severity score, and CURB-65. The sensitivity, specificity, positive and negative predictive values were compared for four different outcomes (death, need for ICU admission, and combined outcomes of death and/or need for ventilatory or inotropic support). RESULTS: 392 patients were included in the analysis; 37 (9.4%) died and 26 (6.6%) required ventilatory and/or inotropic support. The modified BTS severity score performed best for all four outcomes. The PSI (classes IV+V) and CURB had a very similar performance as predictive tools for each outcome. The rATS identified the need for ICU admission well but not mortality. The CURB-65 score predicted mortality well but performed less well when requirement for ICU was included in the outcome of interest. When the combined outcome was evaluated (excluding patients aged >90 years and those from nursing homes), the best predictors were the modified BTS severity score (sensitivity 94.3%) and the PSI and CURB score (sensitivity 83.3% for both). CONCLUSIONS: Different severity scores have different strengths and weaknesses as prediction tools. Validation should be done in the most relevant clinical setting, using more appropriate constructs of "severe pneumonia" to ensure that these potentially useful tools truly deliver what clinicians expect of them.
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Neumonía Bacteriana/diagnóstico , Índice de Severidad de la Enfermedad , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Infecciones Comunitarias Adquiridas/diagnóstico , Infecciones Comunitarias Adquiridas/mortalidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neumonía Bacteriana/mortalidad , Pronóstico , Estudios Prospectivos , Sensibilidad y EspecificidadRESUMEN
Migraine is a pleomorphic condition in which neurologic manifestations may be absent or a minor or a major feature. Similarly, head injury may range from trivial to lethal with regard to neurologic morbidity. Migraine may be precipitated by a variety of stimuli, including head trauma, significant or trivial. Presented is the case of a patient with migrainous hemiparesis precipitated by minor head injury. The clinical features and laboratory and radiological findings of trauma-precipitated migraine are reviewed.
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Traumatismos Craneocerebrales/complicaciones , Hemiplejía/etiología , Trastornos Migrañosos/etiología , Adulto , Diagnóstico Diferencial , Servicio de Urgencia en Hospital , Femenino , Hemiplejía/diagnóstico , Hemiplejía/terapia , Hospitalización , Humanos , Trastornos Migrañosos/diagnóstico , Trastornos Migrañosos/terapia , Examen Neurológico , Tomografía Computarizada por Rayos XRESUMEN
Modern quality management (QM) has evolved in industry over the last few decades to be a major factor in organizational structure and focus. The health industry has to a degree recognized or perceived merits in this model and has applied the principles of QM to many of its activities. It has also incorporated the concept of a commitment to quality improvement (QI) into its most recognized peer-review structure, hospital accreditation (ACHS). Apparent resistance exists in the medical fraternity to a transition from audit-focused quality assurance to contemporary systematic QI. An understanding of this issue may be gained from analysis of the medical profession's perception of QI, factors in the historical structures within health, and a review of the factors which hinder the transition to QI. By considering within a framework of organisational behaviour theory (OBT), some key concepts it is possible to work towards some solutions and proposals. These concepts include attitude, motivation, conflict, organizational change and development. It is likely that the appropriate focus should be broader than the 'recalcitrant group of conservative practitioners who resist change'. Indeed where a deficiency exists, QI methodology would have us look beyond an individual or single group towards the processes that create the opportunity for deficiency to occur. Within the current context, such processes are inherently structural and are historically established within the health industry. A solution to this problem requires organizational commitment and a period of analysis as well as the transformation of attitudes and practices. Organizational commitment will take the form of adequate resourcing and a developmental approach to organizational change. Internal professional change (perhaps guided by organizational development) must address the interface between the 'medical profession' and the broader group of professional health-care providers.
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Gestión de la Calidad Total/organización & administración , Actitud del Personal de Salud , Difusión de Innovaciones , Humanos , Motivación , Innovación Organizacional , Desarrollo de Programa , Gestión de la Calidad Total/métodosRESUMEN
OBJECTIVES: To review and analyse the system effects of the Emergency Service Enhancement Program (ESEP): bonus payments made to public hospitals to improve access to care for patients attending emergency departments. DESIGN: A review of the first 3 years' performance data, obtained from the Victorian Emergency Department Minimum Dataset (VEMD). SETTING: 21 public hospital emergency departments in Victoria, Australia (population 4.5 million), with about 700,000 patient attendances per year. The ESEP began in April 1995. MAIN OUTCOME MEASURES: The ESEP indicators of emergency department and inpatient bed access: occasions of "ambulance bypass" (emergency department unable to accept patients arriving by ambulance); emergency waiting times for Category 1, 2 and 3 patients (National Triage Scale) compared with agreed national performance thresholds; and "access block" (> 12 hours' waiting time in the emergency department before admission to hospital). RESULTS: The number of occasions of ambulance bypass per quarter decreased from 600 in 1994 to fewer than 100 in 1997 (P < 0.001). Despite an increased proportion of patient encounters in triage categories 1, 2 and 3 (31% v. 23%), zero waiting times for Category 1 patients were consistently adhered to, and adherence to waiting time thresholds for Category 2 and 3 patients improved significantly (P < 0.001, R2 = 0.74; and P < 0.035, R2 = 0.37, respectively), particularly for Category 2 patients. The number of patients waiting longer than 12 hours in emergency departments decreased non-significantly (P = 0.3, R2 = 0.1). CONCLUSION: Our results show that the ESEP has produced sustained improvements in all the indicators linked with bonus payments.
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Servicios Médicos de Urgencia/normas , Garantía de la Calidad de Atención de Salud , Reembolso de Incentivo , Triaje/clasificación , Grupos Diagnósticos Relacionados/economía , Servicios Médicos de Urgencia/economía , Servicios Médicos de Urgencia/organización & administración , Servicios Médicos de Urgencia/estadística & datos numéricos , Humanos , Factores de Tiempo , VictoriaRESUMEN
OBJECTIVES: The primary objective was to describe the current level of implementation of quality management (QM) structures and practices with Australian emergency departments. The secondary objective was to describe the level of association between the presence of QM structures and processes and the achievement of associated improvements. DESIGN: Data were collected by mail-out of a structured survey instrument to all Australian emergency departments accredited for postgraduate training by the Australasian College for Emergency Medicine. PARTICIPANTS: Director of Emergency Medicine or delegate in each surveyed department. MAIN OUTCOME MEASURES: The presence of specific structure and process indicators of QM and the achievement of QM linked improvements. RESULTS: A response rate of 63% was achieved. Designation of a hospital quality improvement (QI) physician was reported by 40% of institutions, an emergency department (ED) QI physician by 40%, and an ED QI nurse by 67%. A structured system for QM indicator analysis was present in 67% of the departments; in 45% of the departments public reporting of performance occurred. There was a significant association between QM process indicators and the presence of (i) a hospital QI physician (P=0.02), (ii) an ED QI nurse (P=0.02), (iii) presence of a system for data analysis and reporting (P=0.01), and (iv) presence of a QM component to postgraduate education (P= 0.05). There was a significant relationship between the presence of QM process indicators and the achievement of QM linked improvements (P= 0.003). CONCLUSIONS: Demonstration of the links between QM structures, its indicators of activity (in structure and process), and the achievement of outcome improvement is fundamental to quality improvement methodology. These links are demonstrated within the context of Australian emergency medicine, providing support for the effectiveness of this approach in promoting change and performance improvement.
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Servicio de Urgencia en Hospital/estadística & datos numéricos , Servicio de Urgencia en Hospital/normas , Garantía de la Calidad de Atención de Salud/organización & administración , Australia , Humanos , Auditoría Administrativa , Encuestas y CuestionariosRESUMEN
Western Tennessee contains unusually highly polymorphic populations of southern short-tailed shrews (Blarina carolinensis). We previously documented eight Robertsonian translocations (ROBs) accounting for a variation in diploid number from 46 in most of this species' range to 34-40 in western Tennessee. We have now expanded our study to include data from adjacent areas in Tennessee and Mississippi, 10 localities in all. The new data show a variation in diploid number ranging from 31 to 41, four new ROBs (for a total of 12), and the novel finding of monobrachial translocations in this group. All animals collected from this large area (extending over 12, 000 km(2)) had some level of ROBs, and none represented the 2n = 46 form seen in other parts of the range of this species. Because other species of shrews (genus Sorex) are not affected in the same area, the factors and/or selective forces causing this extensive polymorphism in B. carolinensis must be unique to this species and to this geographic area. Some ROBs were found throughout this large area of over 12,000 km(2). Other translocations (including those with monobrachial homology) were located in one or two localities in this large area, and still other translocations were intermediate in their distribution. There was a concentric pattern to the evolution and presumed spreading of the ROBs. This allowed us to expand the concept of a Robertsonian "fan," introduced by Matthey (1970), to that of concentric evolution of multiple fusion fans: ROBs likely arose independently, separated temporally and geographically, and radiated into surrounding populations to create this complex zone of polymorphism. This is an active process in its infancy, and it is not as mature as that seen in European studies of Mus and Sorex.
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Cromosomas/genética , Evolución Molecular , Modelos Genéticos , Polimorfismo Genético/genética , Musarañas/genética , Translocación Genética/genética , Animales , Células Cultivadas , Diploidia , Variación Genética/genética , Heterocigoto , Cariotipificación , Mississippi , Muestreo , Tennessee , Factores de TiempoRESUMEN
Monolayer cultures of shark rectal gland (SRG) epithelial cells were treated with atriopeptin (AP), and the effects on Cl- secretion and intracellular guanosine 3',5'-cyclic monophosphate (cGMP) accumulation were examined. Basolateral or apical exposure to 10(-7) M AP markedly stimulated (8-fold) Cl(-)-dependent, bumetanide-sensitive, short-circuit current (Isc). The AP-stimulated Isc exhibited transient oscillations before reaching a steady state. This behavior is not observed when Isc is activated by other secretagogues such as vasoactive intestinal peptide, 2-chloroadenosine, forskolin, or ionomycin. Intracellular cGMP was concomitantly elevated (10-fold) by 10(-7) M AP. Both Isc stimulation and cGMP accumulation responses exhibited a similar dose dependency beginning at an AP concentration of 1 nM. The bilateral response to AP suggests the presence of receptors on both apical and basolateral plasma membranes. These results are the first demonstration of a direct effect of AP on Cl(-)-secreting epithelial cells. These data also suggest a role for cGMP in mediating Cl- secretion in these cells.