Rapid whole cell imaging reveals a calcium-APPL1-dynein nexus that regulates cohort trafficking of stimulated EGF receptors.

The endosomal system provides rich signal processing capabilities for responses elicited by growth factor receptors and their ligands. At the single cell level, endosomal trafficking becomes a critical component of signal processing, as exemplified by the epidermal growth factor (EGF) receptors. Activated EGFRs are trafficked to the phosphatase-enriched peri-nuclear region (PNR), where they are dephosphorylated and degraded. The details of the mechanisms that govern the movements of stimulated EGFRs towards the PNR, are not completely known. Here, exploiting the advantages of lattice light-sheet microscopy, we show that EGFR activation by EGF triggers a transient calcium increase causing a whole-cell level redistribution of Adaptor Protein, Phosphotyrosine Interacting with PH Domain And Leucine Zipper 1 (APPL1) from pre-existing endosomes within one minute, the rebinding of liberated APPL1 directly to EGFR, and the dynein-dependent translocation of APPL1-EGF-bearing endosomes to the PNR within ten minutes. The cell spanning, fast acting network that we reveal integrates a cascade of events dedicated to the cohort movement of activated EGF receptors. Our findings support the intriguing proposal that certain endosomal pathways have shed some of the stochastic strategies of traditional trafficking and have evolved processes that provide the temporal predictability that typify canonical signaling.

A Descriptive Study of Chronic Obstructive Pulmonary Disease in Tertiary Care Clinics of a Caribbean Island / Estudio descriptivo de la enfermedad pulmonar obstructiva crónica en clínicas de atención terciaria de una isla caribeña

ABSTRACT Objective: To determine the relationship between severity of chronic obstructive pulmonary disease (COPD) and quality of life as well as COPD's correlation with depressive symptoms in West Indian subjects. Methods: This is a cross-sectional, observational study of outpatients with COPD in tertiary care. The severity of COPD was determined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage, GOLD group, and body mass index, airflow obstruction, dyspnoea and exercise capacity (BODE) index. Quality of life was assessed by the St George Respiratory Questionnaire (SGRQ) and COPD Assessment Test (CAT), and depression was assessed by the Center for Epidemiologic Studies Depression Scale (CES-D). Results: A total of 105 patients (85.7% male, 37.1% Indo-Trinidadian, 42.9% Afro-Trinidadian, 64.8% primary level education) were recruited with a mean age of 66.9 years (standard deviation: 9.60 years). The median body mass index was 25 kg/m2; 26.7% were underweight. Risk factors identified were: ever-smokers (27.6%), marijuana (20%), biomass (81.9%), passive smoke (70.5%), occupational exposures (80%). The CES-D of 25% of the patients was ≥16. Co-morbidities included diabetes (22%), hypertension (29%), gastro-oesophageal reflux disease (10%) and previous myocardial infarction (15%). A total of 59% of the patients reported a monthly household income of less than US$800. Lower level of education was associated with worse SGRQ (total and impact), lower forced expiratory volume in one second, modified Medical Research Council scale (mMRC) of ≥ 2 and higher BODE index. Higher GOLD group correlated with worse SGRQ, CAT and CES-D. Higher CES-D was associated with shorter six-minute walk distance, worse SGRQ, CAT and mMRC scores, higher GOLD group and increased COPD admissions per year. Patients with a CES-D of ≥ 16 walked shorter distances. Higher BODE quartile was associated with worse SGRQ, CAT and CES-D scores. Conclusion: Higher GOLD group and higher BODE quartile were associated with worse quality of life scores and higher depression scores. Patients in higher GOLD groups should be screened for depression. Education on COPD should be targeted at those of lower socioeconomic status.

RESUMEN Objetivo: Determinar la relación entre la severidad de la enfermedad pulmonar obstructiva crónica (EPOC) y la calidad de vida, así como la correlación de la EPOC con síntomas depresivos en sujetos antillanos. Métodos: Se realizó un estudio observacional transversal de pacientes ambulatorios con EPOC en cuidados terciarios. La severidad de la EPOC fue determinada por la etapa de la Iniciativa Global para la Enfermedad Pulmonar Obstructiva Crónica (GOLD, en inglés), el grupo GOLD, así como el índice de masa corporal, la obstrucción del flujo de aire, la disnea y la capacidad de ejercicio (índice BODE). La calidad de vida fue evaluada mediante el Cuestionario Respiratorio de Saint George (CRSG) y la prueba de evaluación de la EPOC (CAT, en inglés), en tanto que la depresión fue evaluada por la Escala de Depresión del Centro de Estudios Epidemiológicos (CES-D). Resultados: Un total de 105 pacientes (85.7% varones, 37.1% indotrinitenses, 42.9% afrotrinitenses, 64.8% nivel de educación primaria) fueron reclutados con una edad promedio de 66.9 años (desviación estándar: 9.60 años). El índice de masa corporal promedio fue de 25 kg/m2; 26.7% por debajo del peso normal. Los factores de riesgo identificados fueron: fumar ocasionalmente (27.6%), marihuana (20%), biomasa (81.9%), humo pasivo (70.5%), exposición ocupacional (80%). El CES-D del 25% de los pacientes fue ≥ 16. Las comorbilidades incluyeron diabetes (22%), hipertensión (29%), enfermedad por reflujo gastroesofágico (10%), y previo infarto del miocardio (15%). Un total de 59% de los pacientes reportaron un ingreso mensual familiar de menos de $800 USD. El nivel más bajo de educación se asoció con un peor (CRSG) (total e impacto), menor volumen espiratorio forzado en un segundo, Escala del Consejo de Investigaciones Médicas modificada (mMRC) de ≥ 2, y más alto índice de BODE. Un grupo más alto de GOLD se correlacionó con peores resultados de CRSG, CAT y CES-D. El CES-D más alto se asoció con una caminata de una distancia más corta en seis minutos, peores puntuaciones de CRSG, CAT y mMRC, un grupo más alto de GOLD, y mayores ingresos de EPOC por año. Los pacientes con CES-D de ≥ 16 caminaron distancias más cortas. El cuartil más alto de BODE estuvo asociado con las puntuaciones peores de CRSG, CAT y CES-D. Conclusión: El grupo GOLD más alto y el cuartil más alto de BODE se asociaron con peores puntuaciones de calidad de vida y puntuaciones de depresión más altas. Los pacientes en los grupos de GOLD más altos deben ser tamizados para detectar si padecen depresión. La educación sobre la EPOC debe estar dirigida a aquellos que tienen una situación socioeconómica inferior.

Immediate reporting of chest X-rays referred from general practice by reporting radiographers: a single centre feasibility study.

AIM: To investigate the feasibility of radiographer-led immediate reporting of chest radiographs (CXRs) referred from general practice. MATERIALS AND METHODS: This 4-month feasibility study (November 2016 to March 2017) was carried out in a single radiology department at an acute general hospital. Comparison was made between CXRs that received an immediate and routine report to determine the number of lung cancers diagnosed, time to diagnosis of lung cancer, time to computed tomography (CT), and number of urgent referrals to respiratory medicine. RESULTS: Forty of 186 sessions (22%) were covered by radiographer immediate reporting. Of the 1,687 CXRs referred from general practice, 558 (33.1%) received an immediate report (radiographer or radiologist). Twenty-two (of 36) CT examinations performed were following an abnormal CXR with an immediate report (mean 0.8 scans/week). Time from CXR to CT was shorter in the immediate report group (n=22 mean 0.9 days SD=2.3) compared to routine reporting (n=14; mean 6.5 SD=3.2; F=27.883, p<0.0001). Time to multidisciplinary team (MDT) discussion was shorter in the immediate reporting group (mean 4.1 SD=2.9) compared to routine reporting (mean 10.6; SD=4.5; F=11.59, p<0.0001). No apparent difference was found for time to discussion at treatment MDT. CONCLUSION: It is feasible to introduce a radiographer-led immediate CXR reporting service. Patients can be taken off the lung cancer pathway sooner with the introduction of radiographer immediate reporting of CXRs and this may improve outcomes for patients. A definitive study assessing outcomes is required to determine whether this will have an impact mortality and morbidity for patients.

Factors responsible for delayed enrollment for anti-retroviral treatment.

BACKGROUND: Late presentation followed by delayed diagnosis and further delayed initiation of anti-retroviral therapy (ART) increases the risk of opportunistic infections and neoplasms among the HIV infected patients. Furthermore, this leads to not only poor response to therapy but also early death among them. METHODS: An institution based cross-sectional study was undertaken to identify the factor(s) responsible for delayed registration for initiation of therapy among the HIV infected patients with absolute CD4 count <250 cells/µL based on self reports. ART naïve adult HIV patients (age ≥18 years) with baseline CD4 count of <250 cells/µL were included in this study. RESULTS: Most patients 95 (95%) were unaware of the available 'Integrated Counseling and Testing Centres'. Although 13 (13%) respondents had multiple reasons for delayed enrollment, majority 47 (47%) of the delays were due to the physician's failure to suspect and refer them for HIV testing at the earliest opportunity. Other causes include health seeking behavior 13 (13%), fear of stigma 5 (5%), depression 3 (3%), and lack of family support 6 (6%). CONCLUSIONS: Even though delays in pre-ART enrollment have been realized since long, prevention efforts are poor, mostly due to the lack of understanding of the nature of the problem in its social context. Lack of clinical suspicion for HIV infection at the primary and secondary levels of health care still remains the most important reason for the delay. In order to prevent these delays in enrollments, intervention efforts need to be focused on not only the people infected with HIV but the primary health care providers as well, especially the practicing physicians.

The ubiquitin ligase CHIP regulates c-Myc stability and transcriptional activity.

c-Myc is a proto-oncogenic transcription factor and its rapid turnover mediated by the ubiquitin-proteasome system is critical for maintaining normal cellular homeostasis. Multiple ubiquitin ligases have been assigned for c-Myc regulation till date. However, the available data suggest for the possible existence of additional E3 ligase(s). Here, we report a new E3 ligase for c-Myc, the carboxyl terminus of Hsc70-interacting protein or CHIP, which is a chaperone-associated Ubox-containing E3 ligase. In this report, we show that CHIP interacts and ubiquitinates c-Myc, thus targeting it for proteasome-mediated degradation. Overexpression of CHIP could accelerate the turnover rate of c-Myc protein. Conversely, knockdown of CHIP by RNAi stabilizes endogenous c-Myc. The interaction between CHIP and c-Myc depends on the N-terminally located tetratricopeptide repeats of CHIP, which has been implicated as a chaperone-binding motif. Inhibition of Hsp90 chaperone activity by 17-N-allylamino-17-demethoxygeldanamycin reduces c-Myc protein level. We found that the association between CHIP and c-Myc is dependent on the chaperones; particularly Hsp70. CHIP antagonizes the transcriptional activity of c-Myc and decreases the abundance of the transcripts of its target genes. Overall, CHIP-knockdown increases malignant behavior of C6 glioma cells. To the best of our knowledge, this is the first report of c-Myc being regulated by a bona-fide chaperone-associated E3 ligase in HEK293 as well as glioma cells. Because CHIP has been reported earlier to be negatively regulating Akt1, BCR-ABL and hTERT, and now c-Myc, the present study may strengthen the view that CHIP acts as a tumor suppressor.

Granulomatous mediastinal adenopathy: can endoscopic ultrasound-guided fine-needle aspiration differentiate between tuberculosis and sarcoidosis?

BACKGROUND AND STUDY AIMS: Mediastinal lymphadenopathy may indicate diseases such as tuberculosis or sarcoidosis, and it is often difficult to establish a diagnosis when standard medical work-up is inconclusive. In this study we investigated the diagnostic yield of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in the differentiation between tuberculosis and sarcoidosis. PATIENTS AND METHODS: In this prospective study, 72 consecutive patients with mediastinal lymphadenopathy, negative endoscopic investigations including bronchoscopic procedures, and no radiological evidence of lung cancer or other malignancies on computed tomography were enrolled. EUS-FNA and subsequent cytology, microscopy for acid-fast bacilli, and culture were performed. At least 12 months' follow-up including further investigations was included to exclude tuberculosis. RESULTS: Adequate samples were obtained from 71/72 patients (36 male; mean age 50.2 years). No complications occurred. The final diagnosis included 30 cases of sarcoidosis, 28 of tuberculosis, four malignancies, one abscess, and nine benign lymphadenopathies. The size of lymph nodes on EUS varied from 0.5 cm to 4.2 cm. Tuberculosis nodes were significantly smaller than those in sarcoidosis. Unrelated nodes were significantly smaller than in either tuberculosis or sarcoidosis. The sensitivity, specificity, and positive and negative predictive values of EUS - FNA for tuberculosis were 86 %, 100 %, 100 %, and 91 %, respectively; those for sarcoidosis were 100 %, 93 %, 91 %, and 100 %, respectively. For culture of tuberculosis, they were 71 %, 100 %, 100 %, and 84 %, respectively. EUS - FNA led to a definite diagnosis in 64/72 cases (89 %) that had not been previously diagnosed by routine methods. CONCLUSION: EUS - FNA offers a high diagnostic yield for the differential diagnosis of tuberculosis and sarcoidosis that have not been diagnosed by conventional methods.

Obstructive lung disease in acute medical patients / Enfermedad pulmonar obstructiva en pacientes clínicos agudos

OBJECTIVES: To determine the proportion of adult medical patients who have chronic obstructive pulmonary disease (COPD), using the Global initiative for Chronic Obstructive Lung Disease guide-lines (GOLD), and its relation to vascular disease. METHODS: This is a prospective cross-sectional study of adult patients admitted to acute medical wards. Interviewer administered questionnaire, anthropometric and spirometric measurements were done. RESULTS: Spirometry was performed in 720 acute admissions [Mean (SD) age 50.0 (18.9) years, FEV1: 1.98L (0.83), FEV1/FVC %: 75.1 (11.9)%; males 332 (46.1%), smokers 318 (44%); 43.2% had vascular disease]. Sixty-seven per cent of patients (480) had no airway disease including 35 (4.5%) with chronic cough and sputum with normal spirometry; 89 (12.4%) had asthma and 151 (20.9%) had COPD. Patients with COPD were significantly older [60.3 (16.6) years] than non-COPD patients [47.3 (18.5) years], p < 0.001 and had a greater number of pack years of smoking. A greater percentage of patients with COPD had vascular disease (52%) than the non-COPD patients (40.1%), p = 0.017). Multivariate analysis with vascular disease as outcome variable revealed relationships with older age (p < 0.001) and Indo-Trinidadian ethnicity (p = 0.015), but not with gender (p = 0.321) and smoking (p = 0.442). FEV1% as well as FEV1 showed a significant inverse relationship with vascular disease (p < 0.05). CONCLUSIONS: The prevalence of COPD using GOLD guidelines in acute hospital admissions is 20.9%; 11.7% of admissions have chronic sputum or cough with normal spirometry. Vascular disease is more prevalent in those with COPD. Patients admitted to acute medical care with vascular disease may also have COPD.

OBJETIVOS: Determinar la proporción de pacientes clínicos adultos con EPOC, mediante la guía clínica de la Iniciativa Global para la Enfermedad Pulmonar Obstructiva Crónica (GOLD, en inglés), y su relación con la enfermedad vascular. MÉTODOS: Este es un estudio transversal prospectivo de pacientes adultos ingresados en salas para la atención de enfermedades agudas. El entrevistador aplicó cuestionarios, y se realizaron mediciones antropométricas y espirométricas. RESULTADOS: La espirometría se realizó en 270 casos de ingresos con enfermedades agudas (edad promedio (SD) 50.0 (18.9) años, FEV1: 1.98 L (0.83), FEV1/FVC %: 75.1 (11.9) %; varones 332 (46.1%), fumadores 318 (44%); 43.2% padecían de enfermedad vascular). El sesenta y siete por ciento de los pacientes (480) no presentaban enfermedades de las vías respiratorias, incluyendo 35 (4.5%) con tos crónica y esputo con espirometría normal; 89 (12.4%) padecían de asma y 151 (20.9%) tenían EPOC. Los pacientes con EPOC eran significativamente mayores [60.3 (16.6) años] que los pacientes sin EPOC [47.3 (18.5) años], p < 0.001 y llevaban un número mayor de paquete-años fumando. Un mayor porcentaje de pacientes con EPOC presentaban enfermedades vasculares (52%) en comparación con los pacientes sin EPOC [(40.1%), p = 0.017)]. El análisis multivariante con la enfermedad vascular como variable dependiente o variable respuesta reveló relaciones con el incremento de los años de edad (p < 0.001) y la etnicidad indo-trinitense (p = 0.015), pero no con el género (p = 0.321) y el hábito de fumar (p = 0.442). FEV1% así como FEV1 mostraron una relación significativa inversa con la enfermedad vascular (p < 0.05). CONCLUSIONES: La prevalencia de EPOC usando la guía clínica GOLD en los ingresos a hospitales debido a enfermedades agudas es de 20.9%; 11.7% de los ingresos presentan esputo crónico y tos con espirometría normal. La enfermedad vascular es más prevalente en pacientes con EPOC. Los pacientes ingresados para atención médica por enfermedad aguda, pueden también presentar EPOC.

Obstructive lung disease in acute medical patients.

OBJECTIVES: To determine the proportion of adult medical patients who have chronic obstructive pulmonary disease (COPD), using the Global initiative for Chronic Obstructive Lung Disease guidelines (GOLD), and its relation to vascular disease. METHODS: This is a prospective cross-sectional study of adult patients admitted to acute medical wards. Interviewer administered questionnaire, anthropometric and spirometric measurements were done. RESULTS: Spirometry was performed in 720 acute admissions [Mean (SD) age 50.0 (18.9) years, FEV1: 1.98 L (0.83), FEV1/FVC%: 75.1 (11.9)%; males 332 (46.1%), smokers 318 (44%); 43.2% had vascular disease]. Sixty-seven per cent of patients (480) had no airway disease including 35 (4.5%) with chronic cough and sputum with normal spirometry; 89 (12.4%) had asthma and 151 (20.9%) had COPD. Patients with COPD were significantly older [60.3 (16.6) years] than non-COPD patients [47.3 (18.5) years], p < 0.001 and had a greater number of pack years of smoking. A greater percentage of patients with COPD had vascular disease (52%) than the non-COPD patients (40.1%), p = 0.017). Multivariate analysis with vascular disease as outcome variable revealed relationships with older age (p < 0.001) and Indo-Trinidadian ethnicity (p = 0.015), but not with gender (p = 0.321) and smoking (p = 0.442). FEV1% as well as FEV1 showed a significant inverse relationship with vascular disease (p < 0.05). CONCLUSIONS: The prevalence of COPD using GOLD guidelines in acute hospital admissions is 20.9%; 11.7% of admissions have chronic sputum or cough with normal spirometry. Vascular disease is more prevalent in those with COPD. Patients admitted to acute medical care with vascular disease may also have COPD.

Effects of exacerbations and seasonality on exhaled nitric oxide in COPD.

Exhaled nitric oxide (eNO) appears to be associated with airway inflammation seen in chronic obstructive pulmonary disease (COPD). The present authors studied the effects of exacerbation, season, temperature and pollution on eNO. eNO was measured seasonally and at exacerbations in 79 outpatients suffering from COPD (mean forced expiratory volume in one second=42%). The effects of exacerbation symptoms, physiological and environmental parameters were analysed. Stable eNO levels were correlated positively with arterial oxygen tension. Median levels were found to be lower in smokers (5.3 ppb) than in ex- or nonsmokers (6.8 ppb). Levels were higher during October to December (6.9 ppb) than in April to June (4.6 ppb). Levels were also higher during 68 exacerbations in 38 patients (7.4 ppb) than in stable conditions (5.4 ppb), independent of the effects of smoking. The rise in eNO was greater in exacerbations that were associated with colds, a sore throat or dyspnoea combined with a cold. In conclusion, exhaled nitric oxide levels were higher in colder weather and in the autumn, perhaps related to the increased prevalence of viral infection at this time of year. The levels were lower in more severe chronic obstructive pulmonary disease. Exhaled nitric oxide levels were raised at the onset of exacerbation, particularly in the presence of a cold.

MMP-9, TIMP-1 and inflammatory cells in sputum from COPD patients during exacerbation.

BACKGROUND: Irreversible airflow obstruction in Chronic Obstructive Pulmonary Disease (COPD) is thought to result from airway remodelling associated with aberrant inflammation. Patients who experience frequent episodes of acute deterioration in symptoms and lung function, termed exacerbations, experience a faster decline in their lung function, and thus over time greater disease severity However the mechanisms by which these episodes may contribute to decreased lung function are poorly understood. This study has prospectively examined changes in sputum levels of inflammatory cells, MMP-9 and TIMP-1 during exacerbations comparing with paired samples taken prior to exacerbation. METHODS: Nineteen COPD patients ((median, [IQR]) age 69 [63 to 74], forced expiratory volume in one second (FEV1) 1.0 [0.9 to 1.2], FEV1% predicted 37.6 [27.3 to 46.2]) provided sputa at exacerbation. Of these, 12 were paired with a samples collected when the patient was stable, a median 4 months [2 to 8 months] beforehand. RESULTS: MMP-9 levels increased from 10.5 microg/g [1.2 to 21.1] prior to exacerbation to 17.1 microg/g [9.3 to 48.7] during exacerbation (P < 0.01). TIMP-1 levels decreased from 3.5 microg/g [0.6 to 7.8] to 1.5 microg/g [0.3 to 4.9] (P = 0.16). MMP-9/TIMP-1 Molar ratio significantly increased from 0.6 [0.2 to 1.1] to 3.6 [2.0 to 25.3] (P < 0.05). Neutrophil, eosinophil and lymphocyte counts all showed significant increase during exacerbation compared to before (P < 0.05). Macrophage numbers remained level. MMP-9 levels during exacerbation showed highly significant correlation with both neutrophil and lymphocyte counts (Rho = 0.7, P < 0.01). CONCLUSION: During exacerbation, increased inflammatory burden coincides with an imbalance of the proteinase MMP-9 and its cognate inhibitor TIMP-1. This may suggest a pathway connecting frequent exacerbations with lung function decline.

Effects of exacerbations and seasonality on exhaled nitric oxide in COPD

Exhaled nitric oxide (eNO) appears to be associated with airway inflammation seen in chronic obstructive pulmonary disease (COPD). The present authors studied the effects of exacerbation, season, temperature and pollution on eNO. eNO was measured seasonally and at exacerbations in 79 outpatients suffering from COPD (mean forced expiratory volume in one second = 42%). The effects of exacerbation symptoms, physiological and environmental parameters were analysed. Stable eNO levels were correlated positively with arterial oxygen tension. Median levels were found to be lower in smokers (5.3 ppb) than in ex- or nonsmokers (6.8 ppb). Levels were higher during October to December (6.9 ppb) than in April to June (4.6 ppb). Levels were also higher during 68 exacerbations in 38 patients (7.4 ppb) than in stable conditions (5.4 ppb), independent of the effects of smoking. The rise in eNO was greater in exacerbations that were associated with colds, a sore throat or dyspnoea combined with a cold. In conclusion, exhaled nitric oxide levels were higher in colder weather and in the autumn, perhaps related to the increased prevalence of viral infection at this time of year. The levels were lower in more severe chronic obstructive pulmonary disease. Exhaled nitric oxide levels were raised at the onset of exacerbation, particularly in the presence of a cold.

Relationship between exacerbation frequency and lung function decline in chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterised by both an accelerated decline in lung function and periods of acute deterioration in symptoms termed exacerbations. The aim of this study was to investigate whether these are related. METHODS: Over 4 years, peak expiratory flow (PEF) and symptoms were measured at home daily by 109 patients with COPD (81 men; median (IQR) age 68.1 (63-74) years; arterial oxygen tension (PaO(2)) 9.00 (8.3-9.5) kPa, forced expiratory volume in 1 second (FEV(1)) 1.00 (0.7-1.3) l, forced vital capacity (FVC) 2.51 (1.9-3.0) l); of these, 32 (29 men) recorded daily FEV(1). Exacerbations were identified from symptoms and the effect of frequent or infrequent exacerbations (> or < 2.92 per year) on lung function decline was examined using cross sectional, random effects models. RESULTS: The 109 patients experienced 757 exacerbations. Patients with frequent exacerbations had a significantly faster decline in FEV(1) and peak expiratory flow (PEF) of -40.1 ml/year (n=16) and -2.9 l/min/year (n=46) than infrequent exacerbators in whom FEV(1) changed by -32.1 ml/year (n=16) and PEF by -0.7 l/min/year (n=63). Frequent exacerbators also had a greater decline in FEV(1) if allowance was made for smoking status. Patients with frequent exacerbations were more often admitted to hospital with longer length of stay. Frequent exacerbations were a consistent feature within a patient, with their number positively correlated (between years 1 and 2, 2 and 3, 3 and 4). CONCLUSIONS: These results suggest that the frequency of exacerbations contributes to long term decline in lung function of patients with moderate to severe COPD.

Roles of cytoskeleton and tyrosine receptor mediated signal transduction in the restitution of isolated guinea pig gastric mucosa.

BACKGROUND: The immediate response of the GI-epithelium to a superficial injury is primarily directed to restore the disturbed epithelial continuity in a process called restitution. The involvement of both structural (cytoskeleton) and humoral (growth factors and cytokines) signal transduction systems in the process has been documented. Previously, in experimental circumstances the role of the two systems has been examined as two distinct units. Nevertheless, in normal conditions in vivo, the two systems are presumably acting simultaneously. This study investigates the functional roles of cytoskeleton and tyrosine receptor mediated signalling in the regulation of restitution. METHODS: Guinea pig gastric mucosa was mounted in Ussing-chamber, injured with 1.25 M NaCl and subsequently perfused for 4 h. Simultaneously, the electrophysiological resistance of the tissue (R) was recorded. During the recovery, the tissue was exposed bilaterally either to modulators of cytoskeleton (cytochalasin B/lysophosphatidic acid) or of tyrosine receptor mediated signalling (genistein/epidermal growth factor + transforming growth factor-alpha). After the experiment, the tissue was analysed morphologically and the proliferative index (PI) was determined morphometrically. RESULTS: Exposure of the tissue to cytochalasin caused a significant decrease of both restitution (tissue resistance) and proliferation (PI), whereas simultaneous treatment with EGF+ TGFalpha restored both restitution and proliferation. Correspondingly, exposure of the tissue to genistein during restitution impaired the process as well as induction of proliferation, while simultaneous exposure to lysophosphatidic acid restored the processes. Exposure of the tissue to EGF+ TGFalpha and lysophosphatidic acid simultaneously resulted in a mild, but insignificant additive inductions of both restitution and proliferation. CONCLUSIONS: Restitution is controlled by both structural and humoral signalling systems. If one of the regulating systems fails, stimulation of the other restores the process. Simultaneous stimulation of both systems has a minor additive effect on both restitution and proliferation.

Respiratory viruses, symptoms, and inflammatory markers in acute exacerbations and stable chronic obstructive pulmonary disease.

The effects of respiratory viral infection on the time course of chronic obstructive pulmonary disease (COPD) exacerbation were examined by monitoring changes in systemic inflammatory markers in stable COPD and at exacerbation. Eighty-three patients with COPD (mean [SD] age, 66.6 [7.1] yr, FEV(1), 1.06 [0.61] L) recorded daily peak expiratory flow rate and any increases in respiratory symptoms. Nasal samples and blood were taken for respiratory virus detection by culture, polymerase chain reaction, and serology, and plasma fibrinogen and serum interleukin-6 (IL-6) were determined at stable baseline and exacerbation. Sixty-four percent of exacerbations were associated with a cold occurring up to 18 d before exacerbation. Seventy-seven viruses (39 [58.2%] rhinoviruses) were detected in 66 (39.2%) of 168 COPD exacerbations in 53 (64%) patients. Viral exacerbations were associated with frequent exacerbators, colds with increased dyspnea, a higher total symptom count at presentation, a longer median symptom recovery period of 13 d, and a tendency toward higher plasma fibrinogen and serum IL-6 levels. Non-respiratory syncytial virus (RSV) respiratory viruses were detected in 11 (16%), and RSV in 16 (23.5%), of 68 stable COPD patients, with RSV detection associated with higher inflammatory marker levels. Respiratory virus infections are associated with more severe and frequent exacerbations, and may cause chronic infection in COPD. Prevention and early treatment of viral infections may lead to a decreased exacerbation frequency and morbidity associated with COPD.

Sputum and plasma endothelin-1 levels in exacerbations of chronic obstructive pulmonary disease.

BACKGROUND: Endothelin (ET)-l is a bronchoconstrictor peptide produced in the airways. It has been implicated in the pathogenesis of asthma and virally mediated airway inflammation and may play a role in exacerbations of chronic obstructive pulmonary disease (COPD). METHODS: Seventy one patients with COPD were followed prospectively and sampled for plasma and sputum ET-1 levels when stable and during an exacerbation. Sputum was also examined for cytokines, human rhinovirus, and Chlamydia pneumoniae. RESULTS: Plasma ET-1 levels were available for 67 patients with stable COPD (mean (SD) 0.58 (0.31) pg/ml); 28 pairs of stable-exacerbation plasma samples had a mean stable ET-1 level of 0.54 (0.30) pg/ml rising to 0.67 (0.35) pg/ml at exacerbation (mean difference 0.13, 95% confidence interval (CI) 0.04 to 0.21, p = 0.004). Plasma ET-1 levels in the 67 patients with stable COPD were inversely correlated with baseline forced expiratory volume in one second (FEV(1); r = -0. 29, p = 0.022) and forced vital capacity (FVC; r = -0.38, p = 0.002). The change in plasma ET-1 levels during an exacerbation correlated with the change in oxygen saturation (SaO(2); r = -0.41, p = 0.036). In 14 stable-exacerbation pairs of sputum samples median stable ET-1 levels were 5.37 (0.97-21.95) pg/ml rising to 34.68 (13.77-51.95) pg/ml during an exacerbation (mean difference 25.14, 95% CI 3.77 to 46.51, p = 0.028). This increase in sputum ET-1 levels correlated with the increase in plasma ET-1 levels (r = 0.917, p = 0.001) and sputum interleukin (IL)-6 levels (r = 0.718, p = 0.013). CONCLUSIONS: Sputum levels of ET-1 rise in COPD patients during an exacerbation and this is reflected by a smaller rise in plasma ET-1 levels. ET-1 may have a role in mediating airway inflammatory changes during exacerbations of COPD.

Multiple-reflection effects in photoelastic stress analysis.

The interpretation of fringes observed in photoelastic stress measurements made with coherent well-collimated optical radiation such as a laser beam and slab specimens with parallel surfaces is affected by multiple internal reflections of light within the sample, which are usually negligible when incoherent light is used. An analysis of the multiple-reflection effects in photoelastic measurements involving the plane polariscope configuration is presented. The results show that the isochromatic fringes are modified by the interference of multiply reflected waves. The multipass differential phase accumulations that display oscillatory magnitudes as functions of the model thickness and the optical wavelength result in a shifted and altered intensity profile across the isochromatic fringes. It is shown that for large values of reflectivity, as in the case of samples with reflective coating or partial mirrors, the bright fringes split into multiple peaks.

Self-phase modulation in polydiacetylene single crystal measured at 720-1064nm.

Detailed measurement of spectral broadening in a poly-[2, 4 hexadiyne-1, 6 diol-bis-(p -toluene sulfonate)] (PTS) single crystal owing to self-phase modulation was performed as a function of wavelength by use of a Ti:sapphire laser producing 200-fs pulses at 720-920 nm and a Nd:YAG laser producing 50-ps pulses at 1064 nm. The nonlinear refractive index (n(2)) of PTS at these wavelengths was determined from the measured phase shift. Group-velocity dispersion was estimated and found to have a negligible effect on the observed spectral broadening. The two-photon absorption coefficient (alpha(2)) over this wavelength range was determined from nonlinear transmission measurements. The largest magnitude of n(2) observed at 720 nm was 3.9x10(-5)cm (2)/MW . The results show that the magnitude of n(2) monotonically decreases as wavelength is increased away from resonance, and two-photon absorption does not make a significant contribution to n(2) at off-resonant wavelengths up to 1064 nm.

Detection of rhinovirus in induced sputum at exacerbation of chronic obstructive pulmonary disease.

Common colds are associated with exacerbations of chronic obstructive pulmonary disease (COPD). However, the role of the common cold virus (human rhinovirus) in the production of symptoms and lower airway inflammation at COPD exacerbation is unknown. Thirty three patients with moderate-to-severe COPD were seen at baseline, when the number of chest infections in the previous year was noted, and acutely at COPD exacerbation. Within 48 h after the onset of the exacerbation and at baseline, nasal aspirates and induced sputum were taken for rhinovirus reverse transcriptase polymerase chain reaction (RT-PCR) analysis and determination of cytokine levels. Symptoms, recorded on diary cards, were noted and forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) measured. At exacerbation, mean FEV1 and FVC fell significantly from baseline (p<0.001). Ten of 43 exacerbations were associated with rhinovirus infection, detected in induced sputum. In four of these, nasopharyngeal samples contained no detectable rhinovirus. All baseline samples were negative for rhinovirus. The simultaneous presence of increased nasal discharge/nasal congestion (in 26 of the 43 exacerbations) and increased sputum (29 exacerbations) was strongly associated with the presence of rhinovirus (odds ratio 6.15; p=0.036). Total symptom scores were greater for rhinovirus as compared to nonrhinovirus exacerbations (p=0.039). Median baseline sputum interleukin-6 levels rose from 90.2 to 140.3 pg x mL(-1) at exacerbation (p=0.005); the change was greater in the presence of rhinovirus infection (p=0.008). Rhinovirus infection can be detected at chronic obstructive pulmonary disease exacerbation. This is associated with elevation of lower airway interleukin-6 levels, which may mediate lower airway symptom expression during chronic obstructive pulmonary disease exacerbations.