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1.
Lancet Respir Med ; 9(11): 1275-1287, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34627560

RESUMEN

BACKGROUND: The impact of COVID-19 on physical and mental health and employment after hospitalisation with acute disease is not well understood. The aim of this study was to determine the effects of COVID-19-related hospitalisation on health and employment, to identify factors associated with recovery, and to describe recovery phenotypes. METHODS: The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a multicentre, long-term follow-up study of adults (aged ≥18 years) discharged from hospital in the UK with a clinical diagnosis of COVID-19, involving an assessment between 2 and 7 months after discharge, including detailed recording of symptoms, and physiological and biochemical testing. Multivariable logistic regression was done for the primary outcome of patient-perceived recovery, with age, sex, ethnicity, body-mass index, comorbidities, and severity of acute illness as covariates. A post-hoc cluster analysis of outcomes for breathlessness, fatigue, mental health, cognitive impairment, and physical performance was done using the clustering large applications k-medoids approach. The study is registered on the ISRCTN Registry (ISRCTN10980107). FINDINGS: We report findings for 1077 patients discharged from hospital between March 5 and Nov 30, 2020, who underwent assessment at a median of 5·9 months (IQR 4·9-6·5) after discharge. Participants had a mean age of 58 years (SD 13); 384 (36%) were female, 710 (69%) were of white ethnicity, 288 (27%) had received mechanical ventilation, and 540 (50%) had at least two comorbidities. At follow-up, only 239 (29%) of 830 participants felt fully recovered, 158 (20%) of 806 had a new disability (assessed by the Washington Group Short Set on Functioning), and 124 (19%) of 641 experienced a health-related change in occupation. Factors associated with not recovering were female sex, middle age (40-59 years), two or more comorbidities, and more severe acute illness. The magnitude of the persistent health burden was substantial but only weakly associated with the severity of acute illness. Four clusters were identified with different severities of mental and physical health impairment (n=767): very severe (131 patients, 17%), severe (159, 21%), moderate along with cognitive impairment (127, 17%), and mild (350, 46%). Of the outcomes used in the cluster analysis, all were closely related except for cognitive impairment. Three (3%) of 113 patients in the very severe cluster, nine (7%) of 129 in the severe cluster, 36 (36%) of 99 in the moderate cluster, and 114 (43%) of 267 in the mild cluster reported feeling fully recovered. Persistently elevated serum C-reactive protein was positively associated with cluster severity. INTERPRETATION: We identified factors related to not recovering after hospital admission with COVID-19 at 6 months after discharge (eg, female sex, middle age, two or more comorbidities, and more acute severe illness), and four different recovery phenotypes. The severity of physical and mental health impairments were closely related, whereas cognitive health impairments were independent. In clinical care, a proactive approach is needed across the acute severity spectrum, with interdisciplinary working, wide access to COVID-19 holistic clinical services, and the potential to stratify care. FUNDING: UK Research and Innovation and National Institute for Health Research.


Asunto(s)
COVID-19 , Estado de Salud , Salud Mental , Enfermedad Aguda , Adulto , Anciano , COVID-19/complicaciones , Cognición , Comorbilidad , Femenino , Estudios de Seguimiento , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Reino Unido/epidemiología
2.
BMC Nephrol ; 22(1): 250, 2021 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-34225671

RESUMEN

BACKGROUND: Taurine depletion occurs in patients with end-stage chronic kidney disease (CKD). In contrast, in the absence of CKD, plasma taurine is reported to increase following dietary L-glutamine supplementation. This study tested the hypothesis that taurine biosynthesis decreases in a rat CKD model, but is rectified by L-glutamine supplementation. METHODS: CKD was induced by partial nephrectomy in male Sprague-Dawley rats, followed 2 weeks later by 2 weeks of 12% w/w L-glutamine supplemented diet (designated NxT) or control diet (NxC). Sham-operated control rats (S) received control diet. RESULTS: Taurine concentration in plasma, liver and skeletal muscle was not depleted, but steady-state urinary taurine excretion (a measure of whole-body taurine biosynthesis) was strongly suppressed (28.3 ± 8.7 in NxC rats versus 78.5 ± 7.6 µmol/24 h in S, P < 0.05), accompanied by reduced taurine clearance (NxC 0.14 ± 0.05 versus 0.70 ± 0.11 ml/min/Kg body weight in S, P < 0.05). Hepatic expression of mRNAs encoding key enzymes of taurine biosynthesis (cysteine sulphinic acid decarboxylase (CSAD) and cysteine dioxygenase (CDO)) showed no statistically significant response to CKD (mean relative expression of CSAD and CDO in NxC versus S was 0.91 ± 0.18 and 0.87 ± 0.14 respectively). Expression of CDO protein was also unaffected. However, CSAD protein decreased strongly in NxC livers (45.0 ± 16.8% of that in S livers, P < 0.005). L-glutamine supplementation failed to rectify taurine biosynthesis or CSAD protein expression, but worsened CKD (proteinuria in NxT 12.5 ± 1.2 versus 6.7 ± 1.5 mg/24 h in NxC, P < 0.05). CONCLUSION: In CKD, hepatic CSAD is depleted and taurine biosynthesis impaired. This is important in view of taurine's reported protective effect against cardio-vascular disease - the leading cause of death in human CKD.


Asunto(s)
Carboxiliasas/metabolismo , Suplementos Dietéticos , Glutamina/administración & dosificación , Hígado/enzimología , Insuficiencia Renal Crónica/metabolismo , Taurina/biosíntesis , Animales , Cisteína-Dioxigenasa/metabolismo , Modelos Animales de Enfermedad , Humanos , Hígado/metabolismo , Masculino , Músculo Esquelético/metabolismo , Nefrectomía , Proteinuria , ARN Mensajero/metabolismo , Ratas Sprague-Dawley , Insuficiencia Renal Crónica/dietoterapia , Taurina/metabolismo
3.
Gastrointest Endosc ; 94(5): 953-958, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34081967

RESUMEN

BACKGROUND AND AIMS: Image-guided radiation therapy (IGRT) often relies on EUS-guided fiducial markers. Previously used manually backloaded fiducial needles have multiple potential limitations including safety and efficiency concerns. Our aim was to evaluate the efficacy, feasibility, and safety of EUS-guided placement of gold fiducials using a novel preloaded 22-gauge needle compared with a traditional, backloaded 19-gauge needle. METHODS: This was a single-center comparative cohort study. Patients with pancreatic and hepatobiliary malignancy who underwent EUS-guided fiducial placement (EUS-FP) between October 2014 and February 2018 were included. The main outcome was the technical success of fiducial placement. Secondary outcomes were mean procedure time, fiducial visibility during IGRT, technical success of IGRT delivery, and adverse events. RESULTS: One hundred fourteen patients underwent EUS-FP during the study period. Of these, 111 patients had successful placement of a minimum of 2 fiducials. Fifty-six patients underwent placement using a backloaded 19-gauge needle and 58 patients underwent placement using a 22-gauge preloaded needle. The mean number of fiducials placed successfully at the target site was significantly higher in the 22-gauge group compared with the 19-gauge group (3.53 ± .96 vs 3.11 ± .61, respectively; P = .006). In the 22-gauge group, the clinical goal of placing 4 fiducials was achieved in 78%, compared with 23% in the 19-gauge group (P < .001). In univariate analyses, gender, age, procedure time, tumor size, and location did not influence the number of successfully placed fiducials. Technical success of IGRT with fiducial tracking was high in both the 19-gauge (51/56, 91%) and the 22-gauge group (47/58, 81%; P = .12). CONCLUSIONS: EUS-FP using a preloaded 22-gauge needle is feasible, effective, and safe and allows for a higher number of fiducials placed when compared with the traditional backloaded 19-gauge needle.


Asunto(s)
Radioterapia Guiada por Imagen , Estudios de Cohortes , Endosonografía , Marcadores Fiduciales , Humanos , Agujas
4.
BMJ Case Rep ; 12(1)2019 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-30700454

RESUMEN

We describe three cases of pulmonary aspergillosis (PA) in three patients without traditional risk factors for invasive aspergillosis infection, such as prolonged neutropenia or high dose systemic corticosteroid therapy. All three patients developed PA while taking tyrosine kinase inhibitors (TKI) and sustained greater clinical improvement once TKI were withdrawn. Our case series supports the theory TKI treatment can increase susceptibility to PA without causing neutropenia. Recognition that TKI treatment may predispose to invasive aspergillosis will allow for rapid recognition of affected patients and more effective management of future cases.


Asunto(s)
Antifúngicos/uso terapéutico , Aspergilosis/tratamiento farmacológico , Tumores del Estroma Gastrointestinal/complicaciones , Infecciones Fúngicas Invasoras/tratamiento farmacológico , Leucemia/complicaciones , Inhibidores de Proteínas Quinasas/farmacología , Anciano , Resultado Fatal , Femenino , Tumores del Estroma Gastrointestinal/tratamiento farmacológico , Humanos , Leucemia/tratamiento farmacológico , Pulmón/diagnóstico por imagen , Pulmón/microbiología , Masculino , Persona de Mediana Edad , Inhibidores de Proteínas Quinasas/uso terapéutico , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
5.
Hear Res ; 363: 28-38, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29605168

RESUMEN

Miniature high frequency ultrasound devices show promise as tools for clinical middle ear and basal cochlea imaging and vibrometry. However, before clinical use it is important to verify that the ultrasound exposure does not damage the cochlea. In this initial study, electrophysiological responses of the cochlea were measured for a range of stimulus frequencies in both ears of anesthetized chinchillas, before and after exposing the organ of Corti region of one ear to pulsed focused ultrasound for 30 min. Measurements were again taken after an 11 day survival period. Cochlear tissue was examined with a confocal microscope for signs of damage to the cochlear hair cells. No significant change in response thresholds due to exposure was found, and no signs of ultrasound-induced tissue damage were observed, although one animal (out of ten) did have a region of extensive tissue damage in the exposed cochlea. However, after further analysis this was concluded to be not likely a result of the ultrasound exposure.


Asunto(s)
Membrana Basilar/diagnóstico por imagen , Cóclea/diagnóstico por imagen , Células Ciliadas Auditivas , Ultrasonografía/métodos , Estimulación Acústica , Animales , Audiometría de Respuesta Evocada , Umbral Auditivo , Membrana Basilar/fisiología , Supervivencia Celular , Chinchilla , Cóclea/fisiología , Diseño de Equipo , Células Ciliadas Auditivas/fisiología , Masculino , Microscopía Confocal , Miniaturización , Valor Predictivo de las Pruebas , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Transductores , Ultrasonografía/efectos adversos , Ultrasonografía/instrumentación
6.
PLoS One ; 12(11): e0188833, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29190798

RESUMEN

Empyema is defined by the presence of bacteria and/or pus in pleural effusions. However, the biology of bacteria within human pleural fluid has not been studied. Streptococcus pneumoniae is the most common cause of pediatric and frequent cause of adult empyema. We investigated whether S. pneumoniae can proliferate within human pleural fluid and if growth is affected by the cellular content of the fluid and/or characteristics of pneumococcal surface proteins. Invasive S. pneumoniae isolates (n = 24) and reference strain recovered from human blood or empyema were inoculated (1.5×106CFU/mL) into sterile human malignant pleural fluid samples (n = 11). All S. pneumoniae (n = 25) strains proliferated rapidly, increasing by a median of 3009 (IQR 1063-9846) from baseline at 24hrs in all pleural effusions tested. Proliferation was greater than in commercial pneumococcal culture media and concentrations were maintained for 48hrs without autolysis. A similar magnitude of proliferation was observed in pleural fluid before and after removal of its cellular content, p = 0.728. S. pneumoniae (D39 strain) wild-type, and derivatives (n = 12), each with mutation(s) in a different gene required for full virulence were inoculated into human pleural fluid (n = 8). S. pneumoniae with pneumococcal surface antigen A (ΔpsaA) mutation failed to grow (2207-fold lower than wild-type), p<0.001, however growth was restored with manganese supplementation. Growth of other common respiratory pathogens (n = 14) across pleural fluid samples (n = 7) was variable and inconsistent, with some strains failing to grow. We establish for the first time that pleural fluid is a potent growth medium for S. pneumoniae and proliferation is dependent on the PsaA surface protein and manganese.


Asunto(s)
Empiema Pleural/microbiología , Derrame Pleural/microbiología , Streptococcus pneumoniae/crecimiento & desarrollo , Humanos , Streptococcus pneumoniae/patogenicidad
7.
Health Technol Assess ; 21(66): 1-80, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-29153075

RESUMEN

BACKGROUND: For patients referred to hospital with suspected colorectal cancer (CRC), it is current standard clinical practice to conduct an examination of the whole colon and rectum. However, studies have shown that an examination of the distal colorectum using flexible sigmoidoscopy (FS) can be a safe and clinically effective investigation for some patients. These findings require validation in a multicentre study. OBJECTIVES: To investigate the links between patient symptoms at presentation and CRC risk by subsite, and to provide evidence of whether or not FS is an effective alternative to whole-colon investigation (WCI) in patients whose symptoms do not suggest proximal or obstructive disease. DESIGN: A multicentre retrospective study using data collected prospectively from two randomised controlled trials. Additional data were collected from trial diagnostic procedure reports and hospital records. CRC diagnoses within 3 years of referral were sourced from hospital records and national cancer registries via the Health and Social Care Information Centre. SETTING: Participants were recruited to the two randomised controlled trials from 21 NHS hospitals in England between 2004 and 2007. PARTICIPANTS: Men and women aged ≥ 55 years referred to secondary care for the investigation of symptoms suggestive of CRC. MAIN OUTCOME MEASURE: Diagnostic yield of CRC at distal (to the splenic flexure) and proximal subsites by symptoms/clinical signs at presentation. RESULTS: The data set for analysis comprised 7380 patients, of whom 59% were women (median age 69 years, interquartile range 62-76 years). Change in bowel habit (CIBH) was the most frequently presenting symptom (73%), followed by rectal bleeding (38%) and abdominal pain (29%); 26% of patients had anaemia. CRC was diagnosed in 551 patients (7.5%): 424 (77%) patients with distal CRC, 122 (22%) patients with cancer proximal to the descending colon and five patients with both proximal and distal CRC. Proximal cancer was diagnosed in 96 out of 2021 (4.8%) patients with anaemia and/or an abdominal mass. The yield of proximal cancer in patients without anaemia or an abdominal mass who presented with rectal bleeding with or without a CIBH or with a CIBH to looser and/or more frequent stools as a single symptom was low (0.5%). These low-risk groups for proximal cancer accounted for 41% (3032/7380) of the cohort; only three proximal cancers were diagnosed in 814 low-risk patients examined by FS (diagnostic yield 0.4%). LIMITATIONS: A limitation to this study is that changes to practice since the trial ended, such as new referral guidelines and improvements in endoscopy quality, potentially weaken the generalisability of our findings. CONCLUSIONS: Symptom profiles can be used to determine whether or not WCI is necessary. Most proximal cancers were diagnosed in patients who presented with anaemia and/or an abdominal mass. In patients without anaemia or an abdominal mass, proximal cancer diagnoses were rare in those with rectal bleeding with or without a CIBH or with a CIBH to looser and/or more frequent stools as a single symptom. FS alone should be a safe and clinically effective investigation in these patients. A cost-effectiveness analysis of symptom-based tailoring of diagnostic investigations for CRC is recommended. TRIAL REGISTRATION: Current Controlled Trials ISRCTN95152621. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 66. See the NIHR Journals Library website for further project information.


Asunto(s)
Enema Opaco/métodos , Colonografía Tomográfica Computarizada/métodos , Colonoscopía/métodos , Neoplasias Colorrectales/diagnóstico , Ensayos Clínicos Controlados Aleatorios como Asunto , Sigmoidoscopía/métodos , Anciano , Neoplasias Colorrectales/diagnóstico por imagen , Detección Precoz del Cáncer , Inglaterra , Femenino , Humanos , Masculino , Estudios Retrospectivos , Sensibilidad y Especificidad
8.
J Antimicrob Chemother ; 72(11): 3181-3186, 2017 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-28961759

RESUMEN

OBJECTIVES: To examine antimicrobial susceptibility patterns and predictors of resistance among Shigella isolates in New South Wales (NSW), Australia during 2013-14 with emphasis on azithromycin. METHODS: Cross-sectional analysis of all shigellosis cases (160) notified to public health authorities in NSW, Australia was performed. RESULTS: Among 160 Shigella isolates tested, 139 (86.9%) were susceptible to azithromycin, 104 (65.0%) to ciprofloxacin and 38 (23.7%) to co-trimoxazole. Ciprofloxacin resistance was 1.9 times more common in infections acquired in Australia compared with those acquired overseas, while azithromycin resistance was 8.5 times more common in males. CONCLUSIONS: We recommend ongoing reconsideration of guidelines for the treatment of shigellosis based on emerging resistance patterns. First-line therapy may need to be reconsidered based on local resistance rates due to common resistance to co-trimoxazole and ciprofloxacin. We recommend culture and susceptibility testing for suspected and proven shigellosis. Azithromycin susceptibility breakpoints for Shigella species may need to be species specific.


Asunto(s)
Antibacterianos/farmacología , Azitromicina/farmacología , Farmacorresistencia Bacteriana Múltiple , Disentería Bacilar/epidemiología , Disentería Bacilar/microbiología , Shigella/efectos de los fármacos , Adolescente , Adulto , Anciano , Antibacterianos/uso terapéutico , Australia/epidemiología , Azitromicina/uso terapéutico , Niño , Preescolar , Ciprofloxacina/farmacología , Ciprofloxacina/uso terapéutico , Estudios Transversales , Disentería Bacilar/tratamiento farmacológico , Femenino , Humanos , Modelos Logísticos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Nueva Gales del Sur/epidemiología , Guías de Práctica Clínica como Asunto , Adulto Joven
9.
J Acoust Soc Am ; 141(6): 4610, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28679279

RESUMEN

The basilar membrane and organ of Corti in the cochlea are essential for sound detection and frequency discrimination in normal hearing. There are currently no methods used for real-time high resolution clinical imaging or vibrometry of these structures. The ability to perform such imaging could aid in the diagnosis of some pathologies and advance understanding of the causes. It is demonstrated that high frequency ultrasound can be used to measure basilar membrane vibrations through the round window of chinchilla cochleas in vivo. The basic vibration characteristics of the basilar membrane agree with previous studies that used other methods, although as expected, the sensitivity of ultrasound was not as high as optical methods. At the best frequency for the recording location, the average vibration velocity amplitude was about 4 mm/s/Pa with stimulus intensity of 50 dB sound pressure level. The displacement noise floor was about 0.4 nm with 256 trial averages (5.12 ms per trial). Although vibration signals were observed, which likely originated from the organ of Corti, the spatial resolution was not adequate to resolve any of the sub-structures. Improvements to the ultrasound probe design may improve resolution and allow the responses of these different structures to be better discriminated.


Asunto(s)
Membrana Basilar/diagnóstico por imagen , Membrana Basilar/fisiología , Cóclea/diagnóstico por imagen , Cóclea/fisiología , Audición , Ultrasonografía/métodos , Estimulación Acústica , Animales , Chinchilla , Diseño de Equipo , Masculino , Mecanotransducción Celular , Miniaturización , Movimiento (Física) , Presión , Sonido , Transductores , Ultrasonografía/instrumentación , Vibración
10.
J Clin Gastroenterol ; 50(10): 828-835, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27548731

RESUMEN

Chronic abdominal wall pain (CAWP) refers to a condition wherein pain originates from the abdominal wall itself rather than the underlying viscera. According to various estimates, 10% to 30% of patients with chronic abdominal pain are eventually diagnosed with CAWP, usually after expensive testing has failed to uncover another etiology. The most common cause of CAWP is anterior cutaneous nerve entrapment syndrome. The diagnosis of CAWP is made using an oft-forgotten physical examination finding known as Carnett's sign, where focal abdominal tenderness is either the same or worsened during contraction of the abdominal musculature. CAWP can be confirmed by response to trigger point injection of local anesthetic. Once diagnosis is made, treatment ranges from conservative management to trigger point injection and in refractory cases, even surgery. This review provides an overview of CAWP, discusses the cost and implications of a missed diagnosis, compares somatic versus visceral innervation, describes the pathophysiology of nerve entrapment, and reviews the evidence behind available treatment modalities.


Asunto(s)
Dolor Abdominal/etiología , Pared Abdominal/inervación , Síndromes de Compresión Nerviosa/diagnóstico , Humanos , Síndromes de Compresión Nerviosa/complicaciones
11.
Lab Invest ; 95(9): 1019-28, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26121320

RESUMEN

Defects in sialylation are known to have serious consequences on podocyte function leading to collapse of the glomerular filtration barrier and the development of proteinuria. However, the cellular processes underlying aberrant sialylation in renal disease are inadequately defined. We have shown in cultured human podocytes that puromycin aminonucleoside (PAN) downregulates enzymes involved in sialic acid metabolism and redox homeostasis and these can be rescued by co-treatment with free sialic acid. The aim of the current study was to ascertain whether sialic acid supplementation could improve renal function and attenuate desialylation in an in vivo model of proteinuria (PAN nephrosis) and to delineate the possible mechanisms involved. PAN nephrotic rats were supplemented with free sialic acid, its precursor N-acetyl mannosamine or the NADPH oxidase inhibitor apocynin. Glomeruli, urine, and sera were examined for evidence of kidney injury and therapeutic efficacy. Of the three treatment regimens, sialic acid had the broadest efficacy in attenuating PAN-induced injury. Proteinuria and urinary nephrin loss were reduced. Transmission electron microscopy revealed that podocyte ultrastructure, exhibited less severe foot process effacement. PAN-induced oxidative stress was ameliorated as evidenced by a reduction in glomerular NOX4 expression and a downregulation of urine xanthine oxidase levels. Sialylation dysfunction was improved as indicated by reduced urinary concentrations of free sialic acid, restored electrophoretic mobility of podocalyxin, and improved expression of a sialyltransferase. These data indicate that PAN induces alterations in the expression of enzymes involved in redox control and sialoglycoprotein metabolism, which can be ameliorated by sialic acid supplementation possibly via its properties as both an antioxidant and a substrate for sialylation.


Asunto(s)
Ácido N-Acetilneuramínico/farmacología , Nefrosis/inducido químicamente , Nefrosis/tratamiento farmacológico , Puromicina Aminonucleósido/efectos adversos , Acetofenonas , Animales , Suplementos Dietéticos , Hexosaminas , Glomérulos Renales/patología , Proteínas de la Membrana/orina , Microscopía Electrónica de Transmisión , Ácido N-Acetilneuramínico/administración & dosificación , NADPH Oxidasa 4 , NADPH Oxidasas/metabolismo , Estrés Oxidativo/fisiología , Podocitos/ultraestructura , Proteinuria/patología , Ratas
12.
Hear Res ; 326: 1-7, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25818516

RESUMEN

Imaging techniques currently used in the clinic to inspect ears in patients are generally limited to views terminating at the tympanic membrane (TM) surface. For imaging past the TM, methods such as computed tomography are typically used, but in addition to disadvantages such as being costly, time consuming, and causing radiation exposure, these often do not provide sufficient resolution of the middle ear structures of interest. This study presents an investigation into the capability of high frequency ultrasound to image the middle ear with high resolution in real-time, as well as measure vibrations of TM and middle ear structures in response to sound stimuli. In unfixed cadaver ears, the TM, ossicles, and ossicular support tissues were all readily identifiable, with capabilities demonstrated for real-time imaging and video capture, and vibrometry of middle ear structures. Based on these results, we conclude that high frequency ultrasonography is a relatively simple and minimally invasive technology with great potential to provide clinicians with new tools for diagnosing and monitoring middle ear pathologies.


Asunto(s)
Oído Medio/diagnóstico por imagen , Oído Medio/fisiología , Estimulación Acústica , Cadáver , Sistemas de Computación , Osículos del Oído/diagnóstico por imagen , Osículos del Oído/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Membrana Timpánica/diagnóstico por imagen , Membrana Timpánica/fisiología , Ultrasonografía , Vibración
13.
Infect Immun ; 83(3): 1181-9, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25583525

RESUMEN

Although the importance of alveolar macrophages for host immunity during early Streptococcus pneumoniae lung infection is well established, the contribution and relative importance of other innate immunity mechanisms and of bacterial factors are less clear. We have used a murine model of S. pneumoniae early lung infection with wild-type, unencapsulated, and para-amino benzoic acid auxotroph mutant TIGR4 strains to assess the effects of inoculum size, bacterial replication, capsule, and alveolar macrophage-dependent and -independent clearance mechanisms on bacterial persistence within the lungs. Alveolar macrophage-dependent and -independent (calculated indirectly) clearance half-lives and bacterial replication doubling times were estimated using a mathematical model. In this model, after infection with a high-dose inoculum of encapsulated S. pneumoniae, alveolar macrophage-independent clearance mechanisms were dominant, with a clearance half-life of 24 min compared to 135 min for alveolar macrophage-dependent clearance. In addition, after a high-dose inoculum, successful lung infection required rapid bacterial replication, with an estimated S. pneumoniae doubling time of 16 min. The capsule had wide effects on early lung clearance mechanisms, with reduced half-lives of 14 min for alveolar macrophage-independent and 31 min for alveolar macrophage-dependent clearance of unencapsulated bacteria. In contrast, with a lower-dose inoculum, the bacterial doubling time increased to 56 min and the S. pneumoniae alveolar macrophage-dependent clearance half-life improved to 42 min and was largely unaffected by the capsule. These data demonstrate the large effects of bacterial factors (inoculum size, the capsule, and rapid replication) and alveolar macrophage-independent clearance mechanisms during early lung infection with S. pneumoniae.


Asunto(s)
Inmunidad Innata , Pulmón/inmunología , Macrófagos Alveolares/inmunología , Modelos Estadísticos , Neumonía Neumocócica/inmunología , Streptococcus pneumoniae/inmunología , Ácido 4-Aminobenzoico/metabolismo , Animales , Cápsulas Bacterianas/inmunología , Carga Bacteriana/inmunología , Femenino , Semivida , Pulmón/microbiología , Pulmón/patología , Macrófagos Alveolares/microbiología , Macrófagos Alveolares/patología , Masculino , Ratones , Ratones Endogámicos , Mutación , Fagocitosis , Neumonía Neumocócica/microbiología , Neumonía Neumocócica/patología , Índice de Severidad de la Enfermedad , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/crecimiento & desarrollo , Factores de Tiempo
14.
Mol Microbiol ; 82(4): 904-16, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22023106

RESUMEN

Zinc is an essential trace metal for living cells. The ABC transporter AdcABC was previously shown to be required for zinc uptake by Streptococcus pneumoniae. As we have recently described AdcAII as another zinc-binding lipoprotein, we have investigated the role of both AdcA and AdcAII in S. pneumoniae zinc metabolism. Deletion of either adcA or adcAII but not phtD reduced S. pneumoniae zinc uptake, with dual mutation of both adcA and adcAII further decreasing zinc import. For the Δ(adcA/adcAII) mutant, growth and intracellular concentrations of zinc were both greatly reduced in low zinc concentration. When grown in zinc-deficient medium, the Δ(adcA/adcAII) mutant displayed morphological defects related to aberrant septation. Growth and morphology of the Δ(adcA/adcAII) mutant recovered after supplementation with zinc. Dual deletion of adcA and adcAII strongly impaired growth of the pneumococcus in bronchoalveolar lavage fluid and human serum, and prevented S. pneumoniae establishing infection in mouse models of nasopharyngeal colonization, pneumonia and sepsis without altering the capsule. Taken together, our results show that AdcA and AdcAII play an essential and redundant role in specifically importing zinc into the pneumococcus, and that both zinc transporters are required for proper cell division and for S. pneumoniae survival during infection.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/metabolismo , Proteínas Bacterianas/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Streptococcus pneumoniae/citología , Streptococcus pneumoniae/patogenicidad , Factores de Virulencia/metabolismo , Zinc/metabolismo , Transportadoras de Casetes de Unión a ATP/genética , Animales , Proteínas Bacterianas/genética , Líquido del Lavado Bronquioalveolar/microbiología , División Celular , Medios de Cultivo/química , Modelos Animales de Enfermedad , Humanos , Proteínas de Transporte de Membrana/genética , Ratones , Viabilidad Microbiana , Nasofaringe/microbiología , Infecciones Neumocócicas/microbiología , Sepsis/microbiología , Suero/microbiología , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/metabolismo , Virulencia , Factores de Virulencia/genética
15.
Biochemistry ; 50(17): 3551-8, 2011 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-21425866

RESUMEN

Zinc homeostasis is critical for pathogen host colonization. Indeed, during invasion, Streptococcus pneumoniae has to finely regulate zinc transport to cope with a wide range of Zn(2+) concentrations within the various host niches. AdcAII was identified as a pneumococcal Zn(2+)-binding protein; its gene is present in an operon together with the phtD gene. PhtD belongs to the histidine triad protein family, but to date, its function has not been clarified. Using several complementary biochemical methods, we provide evidence that like AdcAII, PhtD is a metal-binding protein specific for zinc. When Zn(2+) binds (K(d) = 131 ± 10 nM), the protein displays substantial thermal stabilization. We also present the first direct evidence of a joint function of AdcAII and PhtD by demonstrating that their expression is corepressed by Zn(2+), that they interact directly in vitro, and that they are colocalized at the bacterial surface. These results suggest the common involvement of the AdcAII-PhtD system in pneumococcal zinc homeostasis.


Asunto(s)
Proteínas Bacterianas/metabolismo , Proteínas Portadoras/metabolismo , Proteínas de Transporte de Catión/metabolismo , Hidrolasas/metabolismo , Streptococcus pneumoniae/metabolismo , Zinc/metabolismo , Secuencias de Aminoácidos , Proteínas Bacterianas/química , Proteínas Portadoras/química , Proteínas de Transporte de Catión/química , Hidrolasas/química , Lipoproteínas/química , Lipoproteínas/metabolismo , Proteínas Recombinantes/química
16.
Am J Emerg Med ; 23(1): 30-4, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15672334

RESUMEN

OBJECTIVE: To establish a clinical pathway for outpatient enoxaparin therapy in deep venous thrombosis (DVT) and then characterize its implementation and barriers to use. PROCEDURE: Single institution, prospective, observational study of consecutive adult emergency department patients (age > or =18 years) who had a diagnosis of DVT. A clinical pathway was created to facilitate outpatient therapy with enoxaparin, and then all patients with DVT were enrolled and studied. RESULTS: A total of 97/98 (99%) eligible patients were enrolled. Among 97 patients, 29 (30%) were successfully started on the outpatient enoxaparin therapy approach. Of the 68 (70%) patients not started on the outpatient therapy, 19 (20%) patients had contraindications to anticoagulant therapy, 33 (34%) had other indications for hospitalization, 6 (6%) were unable to reliably self-inject, and 10 (10%) patients had a primary care physician or emergency physician who rejected the outpatient approach. CONCLUSIONS: The establishment of an organized DVT pathway for outpatient enoxaparin may facilitate home therapy; however, there will remain reasons that make hospital admission unavoidable in some patients.


Asunto(s)
Atención Ambulatoria/estadística & datos numéricos , Anticoagulantes/uso terapéutico , Vías Clínicas/estadística & datos numéricos , Enoxaparina/uso terapéutico , Trombosis de la Vena/tratamiento farmacológico , Atención Ambulatoria/normas , Protocolos Clínicos , Utilización de Medicamentos , Femenino , Hospitalización/estadística & datos numéricos , Humanos , Masculino , Massachusetts , Persona de Mediana Edad , Selección de Paciente , Estudios Prospectivos , Garantía de la Calidad de Atención de Salud/métodos
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