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1.
J Hepatol ; 72(1): 34-44, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31348999

RESUMEN

BACKGROUND & AIMS: Knowledge about the regulation of anti-HBV humoral immunity during natural HBV infection is limited. We recently utilized dual fluorochrome-conjugated HBsAg to demonstrate, in patients with chronic HBV (CHB) infection, the functional impairment of their HBsAg-specific B cells. However, the features of their HBcAg-specific B cells are unknown. Here we developed a method to directly visualize, select and characterize HBcAg-specific B cells in parallel with HBsAg-specific B cells. METHODS: Fluorochrome-conjugated HBcAg reagents were synthesized and utilized to directly detect ex vivo HBcAg-specific B cells in 36 patients with CHB. The frequency, phenotype, functional maturation and transcriptomic profile of HBcAg-specific B cells was studied by flow cytometry, in vitro maturation assays and NanoString-based detection of expression of immune genes, which we compared with HBsAg-specific B cells and total B cells. RESULTS: HBcAg-specific B cells are present at a higher frequency than HBsAg-specific B cells in patients with CHB and, unlike HBsAg-specific B cells, they mature efficiently into antibody-secreting cells in vitro. Their phenotypic and transcriptomic profiles show that HBcAg-specific B cells are preferentially IgG+ memory B cells. However, despite their phenotypic and functional differences, HBcAg- and HBsAg-specific B cells from patients with CHB share an mRNA expression pattern that differs from global memory B cells and is characterized by high expression of genes indicative of cross-presentation and innate immune activity. CONCLUSIONS: During chronic HBV infection, a direct relation exists between serological detection of anti-HBs and anti-HBc antibodies, and the quantity and function of their respective specific B cells. However, the transcriptomic analysis performed in HBsAg- and HBcAg-specific B cells suggests additional roles of HBV-specific B cells beyond the production of antibodies. LAY SUMMARY: Protection of viral infection necessitates the production of antibodies that are generated by specialized cells of the immune system called B cells. During chronic HBV infection, antibodies against the internal part of the virus (core or HBcAg) are detectable while the antibodies directed against the virus envelope (surface or HBsAg) are not present. Here we developed a method that allows us to directly visualize ex vivo the B cells specific for these 2 viral components, highlighting their differences and similarities, and showing how 2 components of the same virus can have different impacts on the function of antiviral B cells.


Asunto(s)
Linfocitos B/inmunología , Antígenos del Núcleo de la Hepatitis B/inmunología , Antígenos de Superficie de la Hepatitis B/inmunología , Virus de la Hepatitis B/inmunología , Hepatitis B Crónica/inmunología , Proteínas de la Nucleocápside/inmunología , Proteínas del Envoltorio Viral/inmunología , Adolescente , Adulto , Niño , Estudios de Cohortes , ADN Viral/sangre , ADN Viral/inmunología , Femenino , Anticuerpos contra la Hepatitis B/sangre , Hepatitis B Crónica/sangre , Hepatitis B Crónica/virología , Humanos , Masculino , Persona de Mediana Edad , Fenotipo , Transcriptoma , Adulto Joven
2.
Neuroimage ; 194: 272-282, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-30894331

RESUMEN

The thalamus and its nuclei are largely indistinguishable on standard T1 or T2 weighted MRI. While diffusion tensor imaging based methods have been proposed to segment the thalamic nuclei based on the angular orientation of the principal diffusion tensor, these are based on echo planar imaging which is inherently limited in spatial resolution and suffers from distortion. We present a multi-atlas segmentation technique based on white-matter-nulled MP-RAGE imaging that segments the thalamus into 12 nuclei with computation times on the order of 10 min on a desktop PC; we call this method THOMAS (THalamus Optimized Multi Atlas Segmentation). THOMAS was rigorously evaluated on 7T MRI data acquired from healthy volunteers and patients with multiple sclerosis by comparing against manual segmentations delineated by a neuroradiologist, guided by the Morel atlas. Segmentation accuracy was very high, with uniformly high Dice indices: at least 0.85 for large nuclei like the pulvinar and mediodorsal nuclei and at least 0.7 even for small structures such as the habenular, centromedian, and lateral and medial geniculate nuclei. Volume similarity indices ranged from 0.82 for the smaller nuclei to 0.97 for the larger nuclei. Volumetry revealed that the volumes of the right anteroventral, right ventral posterior lateral, and both right and left pulvinar nuclei were significantly lower in MS patients compared to controls, after adjusting for age, sex and intracranial volume. Lastly, we evaluated the potential of this method for targeting the Vim nucleus for deep brain surgery and focused ultrasound thalamotomy by overlaying the Vim nucleus segmented from pre-operative data on post-operative data. The locations of the ablated region and active DBS contact corresponded well with the segmented Vim nucleus. Our fast, direct structural MRI based segmentation method opens the door for MRI guided intra-operative procedures like thalamotomy and asleep DBS electrode placement as well as for accurate quantification of thalamic nuclear volumes to follow progression of neurological disorders.


Asunto(s)
Mapeo Encefálico/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Núcleos Talámicos/anatomía & histología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad
4.
J Urol ; 189(3): 828-33, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23017513

RESUMEN

PURPOSE: We determined the risk of disease specific mortality in patients with primary, low risk, noninvasive (G1pTa) bladder cancer and compared it to disease specific mortality in age and gender matched general populations. MATERIALS AND METHODS: We identified all patients with primary low risk cancer at our institution. We excluded those with adverse pathological features and then matched histopathology, pharmacy, hospital episode and Cancer Registry records. We reviewed case notes on patients with subsequent muscle invasion (progression) or disease specific mortality. Patients underwent post-resection surveillance and treatment using standard regimens. National and regional disease specific mortality rates were calculated from appropriate data. RESULTS: A total of 699 patients met study inclusion criteria. Median followup was 61 months (IQR 24-105). Of the patients 17 (2.4%) died of bladder cancer, including 13 of 14 with progression to muscle invasion and 4 of 19 with grade progression to high grade, nonmuscle invasive disease. On Cox regression analyses low grade dysplasia in the initial resection specimen and tumor weight were associated with disease specific mortality (p <0.003). Disease specific mortality in these patients was 5 times the background rate in matched populations. Limitations of this study include its retrospective nature and the low frequency of adverse events. CONCLUSIONS: Patients with low risk bladder cancer rarely progress to muscle invasion but they are at higher risk for disease specific mortality than the general population. Current surveillance regimens appear ineffective for detecting progression in time to alter prognosis.


Asunto(s)
Carcinoma de Células Transicionales/mortalidad , Cistectomía , Cistoscopía/métodos , Sistema de Registros , Neoplasias de la Vejiga Urinaria/mortalidad , Anciano , Carcinoma de Células Transicionales/diagnóstico , Carcinoma de Células Transicionales/cirugía , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia/tendencias , Reino Unido/epidemiología , Neoplasias de la Vejiga Urinaria/diagnóstico , Neoplasias de la Vejiga Urinaria/cirugía
5.
Urol Case Rep ; 50: 102421, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37719181

RESUMEN

CHEK2 mutations have been noted in bone, brain, breast, colon, lung, thyroid, and prostate cancer. Although now reported in both clear cell and non-clear cell renal cancer, we have not found CHEK2 2 mutations reported in the papillary type II subtype (PRCC). Here, we report a 63-year-old female with a PRCC type II with a concomitant CHEK2 C1100del mutation, who is currently in complete remission three years post tumor resection.

6.
Cancer ; 118(22): 5525-34, 2012 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-22544645

RESUMEN

BACKGROUND: The treatment of high-risk nonmuscle-invasive bladder cancer (NMIBC) is difficult given its unpredictable natural history and patient comorbidities. Because current case series are mostly limited in size, the authors report the outcomes from a large, single-center series. METHODS: The authors reviewed all patients with primary, high-risk NMIBC at their institution from 1994 to 2010. Outcomes were matched with clinicopathologic data. Patients who had muscle invasion within 6 months or had insufficient follow-up (<6 months) were excluded. Correlations were analyzed using multivariable Cox regression and log-rank analysis (2-sided; P < .05). RESULTS: In total, 712 patients (median age, 73.7 years) were included. Progression to muscle invasion occurred in 110 patients (15.8%; 95% confidence interval [CI], 13%-18.3%) at a median of 17.2 months (interquartile range, 8.9-35.8 months), including 26.5% (95% CI, 22.2%-31.3%) of the 366 patients who had >5 years follow-up. Progression was associated with age (hazard ratio [HR], 1.04; P = .007), dysplastic urothelium (HR, 1.6; P = .003), urothelial cell carcinoma variants (HR, 3.2; P = .001), and recurrence (HR, 18.3; P < .001). Disease-specific mortality occurred in 134 patients (18.8%; 95% CI, 16.1%-21.9%) at a median of 28 months (interquartile range, 15-45 months), including 28.7% (95% CI, 24.5%-33.3%) of those who had 5 years of follow-up. Disease-specific mortality was associated with age (HR, 1.1; P < .001), stage (HR, 1.7; P = .003), dysplasia (HR, 1.3; P = .05), and progression (HR, 5.2; P < .001). Neither progression nor disease-specific mortality were associated with the receipt of bacillus Calmette-Guerin (P > .6). CONCLUSIONS: Within a program of conservative treatment, progression of high-risk NMIBC was associated with a poor prognosis. Surveillance and bacillus Calmette-Guerin were ineffective in altering the natural history of this disease. The authors concluded that the time has come to rethink the paradigm of management of this disease.


Asunto(s)
Neoplasias de la Vejiga Urinaria/mortalidad , Neoplasias de la Vejiga Urinaria/terapia , Adulto , Anciano , Anciano de 80 o más Años , Vacuna BCG/uso terapéutico , Cistectomía , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Invasividad Neoplásica , Recurrencia Local de Neoplasia , Resultado del Tratamiento , Neoplasias de la Vejiga Urinaria/patología
7.
Artículo en Inglés | MEDLINE | ID: mdl-34955458

RESUMEN

BACKGROUND AND OBJECTIVES: There has been growing interest in potential roles of the immune system in the pathogenesis of Parkinson disease (PD). The aim of the current study was to comprehensively characterize phenotypic and functional profiles of circulating immune cells in patients with PD vs controls. METHODS: Peripheral blood was collected from patients with PD and age- and sex-matched neurologically normal controls (NCs) in 2 independent cohorts (discovery and validation). Comprehensive multicolor flow cytometry was performed on whole blood leukocytes and peripheral blood mononuclear cells to characterize different immune subsets and their ex vivo responses. RESULTS: The discovery cohort included 17 NCs and 12 participants with PD, and the validation cohort included 18 NCs and 18 participants with PD. Among major immune cell types, B cells appeared to be preferentially affected in PD. Proliferating B cell counts were decreased in patients with PD compared with controls. Proportions of B-cell subsets with regulatory capacity such as transitional B cells were preferentially reduced in the patients with PD, whereas proportions of proinflammatory cytokine-producing B cells increased, resulting in a proinflammatory shift of their B-cell functional cytokine responses. Unsupervised principal component analysis revealed increased expression of TNFα and GM-CSF by both B cells and T cells of patients with PD. In addition, levels of follicular T cells, an important B-cell helper T-cell population, decreased in the patients with PD, correlating with their B-cell abnormality. DISCUSSION: Our findings define a novel signature of peripheral immune cells and implicate aberrant Tfh:B-cell interactions in patients with PD.


Asunto(s)
Linfocitos B , Enfermedad de Parkinson/sangre , Enfermedad de Parkinson/inmunología , Células T Auxiliares Foliculares , Anciano , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad
8.
Cell Death Differ ; 29(2): 293-305, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34974533

RESUMEN

Huntington's disease is caused by a pathologically long (>35) CAG repeat located in the first exon of the Huntingtin gene (HTT). While pathologically expanded CAG repeats are the focus of extensive investigations, non-pathogenic CAG tracts in protein-coding genes are less well characterized. Here, we investigated the function and evolution of the physiological CAG tract in the HTT gene. We show that the poly-glutamine (polyQ) tract encoded by CAGs in the huntingtin protein (HTT) is under purifying selection and subjected to stronger selective pressures than CAG-encoded polyQ tracts in other proteins. For natural selection to operate, the polyQ must perform a function. By combining genome-edited mouse embryonic stem cells and cell assays, we show that small variations in HTT polyQ lengths significantly correlate with cells' neurogenic potential and with changes in the gene transcription network governing neuronal function. We conclude that during evolution natural selection promotes the conservation and purity of the CAG-encoded polyQ tract and that small increases in its physiological length influence neural functions of HTT. We propose that these changes in HTT polyQ length contribute to evolutionary fitness including potentially to the development of a more complex nervous system.


Asunto(s)
Enfermedad de Huntington , Péptidos , Animales , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismo , Enfermedad de Huntington/patología , Ratones , Neuronas/metabolismo , Péptidos/genética , Péptidos/metabolismo
9.
Eur Urol Focus ; 7(3): 554-565, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-32576531

RESUMEN

BACKGROUND: The 2002 National Institute for Health and Care Excellence guidance on centralisation of radical cystectomy (RC) coincided with changes in practice: use of neoadjuvant chemotherapy (NAC) and pelvic lymph node dissection (PLND), and RC for high-risk non-muscle-invasive bladder cancer (HR-NMIBC). OBJECTIVE: To report the outcomes of RC at a single centre and to compare trends in survival with respect to centralisation and change in RC practice. DESIGN, SETTING, AND PARTICIPANTS: Data were collected retrospectively between 1 January 1994 and 31 December 2016. Patients with urothelial cell carcinoma (UCC) were selected. Outcomes from 1994 to 2007 (before centralisation, era 1) were compared with those from 2008 to 2016 (after centralisation, era 2). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was disease-specific mortality. Secondary outcomes were survival and use of NAC and PLND. RESULTS AND LIMITATIONS: Overall, 1100 RCs (era 1, 316; era 2, 794) were performed for UCC. Median (interquartile range [IQR]) follow-up was 28.5 (11.9-57.4) mo. RC for NMIBC was 36.2% versus 51.3% (p<0.001), NAC use was 2.2% versus 31.6% (p<0.001), and PLND use was 59.7% versus 76.4% (p<0.001) in era 1 versus era 2. The 30-d (1.6% [era 1] vs 0.8% [era 2], p=0.21) and 90-d (4.1% vs 2.6%, p=0.2) mortality rates did not differ with respect to RC year. Five-year disease-specific survival (DSS) was 56.0% in era 1 versus 79.0% in era 2 (p<0.001). RC for patients aged ≥75 yr was 13.9% versus 28.1% (p<0.001) and 30-d mortality in this group was 4.5% versus 0% (p=0.001) in era 1 versus era 2. The study is limited by its retrospective design. CONCLUSIONS: Centralisation was associated with higher rates of NAC and PLND use, and increased RC performed for older patients and patients with HR-NMIBC. DSS was higher and RC appeared to be safer for older patients (fewer postoperative mortalities) after centralisation. PATIENT SUMMARY: We looked at outcomes from bladder removal for bladder cancer. Survival outcomes improved following centralisation of services. Surgery appeared to be safer for older patients, as there were fewer postoperative mortalities after centralisation. Centralisation of radical cystectomy (RC) services was associated with higher rates of neoadjuvant chemotherapy and pelvic lymph node dissection use, and increased usage of RC for older patients with high-risk non-muscle-invasive bladder cancer. Survival outcomes from RC were superior after centralisation and safer for older patients undergoing RC (fewer postoperative mortalities).


Asunto(s)
Carcinoma de Células Transicionales , Neoplasias de la Vejiga Urinaria , Carcinoma de Células Transicionales/patología , Carcinoma de Células Transicionales/cirugía , Cistectomía/métodos , Humanos , Estudios Retrospectivos , Vejiga Urinaria/patología , Neoplasias de la Vejiga Urinaria/patología
10.
Prostate ; 70(8): 856-65, 2010 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-20127733

RESUMEN

BACKGROUND: Tumor growth is influenced by an increase in cell proliferation and a reduction in apoptosis; both of which are affected by alterations in extracellular matrix (ECM). Our aim was to assess if the susceptibility of prostate cancer cells to apoptosis induced by either chemotherapeutics or radiotherapy was altered by changes in the ECM. METHODS: Prostate cancer cell lines LNCaP and DU145 (androgen independent) cells were treated with chemotherapeutics (ceramide and docetaxel) or radiotherapy in the presence or absence of fibronectin, laminin, or vitronectin. Cell death was assessed using Trypan blue cell counting and apoptosis was confirmed by measuring PARP cleavage by Western immunoblotting (WIB). To identify a mechanism of action, changes in the abundance (WIB) or association (immunoprecipitation followed by WIB) of key proteins was also assessed. RESULTS: We found that fibronectin, but not laminin or vitronectin activated a survival pathway that protected DU145 but not LNCaP prostate cancer cells against ceramide and docetaxel-induced apoptosis but not that induced by radiotherapy. This survival effect involved the insulin-like growth factor (IGF-I) and beta1 integrin receptors and was associated with an increase in the recruitment of the beta1 integrin to a complex containing the IGF-IR and protein receptor for activated C kinase (RACK-1) and an increase in the abundance of a MAPK-phosphatase-1 (MKP-1). CONCLUSIONS: Changes in the ECM associated with disease progression may contribute to resistance to chemotherapeutic drugs but not to radiation therapy. The susceptibility to chemotherapy may be improved by targeting either the IGF-I or beta1 integrin receptors.


Asunto(s)
Supervivencia Celular/efectos de los fármacos , Fibronectinas/metabolismo , Próstata/efectos de los fármacos , Receptor IGF Tipo 1/metabolismo , Análisis de Varianza , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/efectos de la radiación , Western Blotting , Recuento de Células , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Proliferación Celular/efectos de la radiación , Supervivencia Celular/efectos de la radiación , Células Cultivadas , Ceramidas/farmacología , Docetaxel , Relación Dosis-Respuesta a Droga , Fosfatasa 1 de Especificidad Dual/metabolismo , Humanos , Integrinas/metabolismo , Laminina/metabolismo , Masculino , Próstata/metabolismo , Próstata/efectos de la radiación , Fármacos Sensibilizantes a Radiaciones/farmacología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/efectos de la radiación , Taxoides/farmacología , Vitronectina/metabolismo
11.
Prostate ; 69(2): 219-24, 2009 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-18942120

RESUMEN

BACKGROUND: Compelling evidence has accumulated for chemopreventive effects for the active component of green tea Epigallocatechin-3-Gallate (EGCG) particularly for prostate cancer (CaP). METHODS: We have assessed interactions between the effects of EGCG and two main regulators of prostate cell function, dihydrotestosterone (DHT) and insulin-like growth factor-1 (IGF-I). Using LNCaP (androgen-sensitive), PC3 and DU145 (androgen-resistant) CaP cell lines, we assessed the effect of EGCG alone on growth (0-200 microM) and on cell death (0-50 microM). RESULTS: EGCG decreased the proliferation of all the CaP cancer cells in a dose-dependent manner with an increase in apoptosis from 30 to 50 microM. With DU145 cells, a sub-apoptotic dose of EGCG (10-20 microM) reduced IGF-induced growth. With LNCaP cells, a sub-apoptotic dose of EGCG (8 microM) switched DHT from a growth promoter to a growth inhibitor. A similar reversal of DHT effect was seen in the presence of an IGF-I receptor inhibitor, AG1024 (1 microM). These responses appeared to be due to DHT sensitizing the cells to apoptosis by EGCG and AG1024 (P < 0.01 and P < 0.001 respectively). CONCLUSIONS: Our data suggests that both green tea and AG1024 are effective in inhibiting cell growth and inducing death in CaP cells but the effects of both are more effective in the presence of androgen.


Asunto(s)
Catequina/análogos & derivados , Muerte Celular/efectos de los fármacos , Dihidrotestosterona/farmacología , Neoplasias de la Próstata/patología , Receptor IGF Tipo 1/fisiología , Western Blotting , Catequina/fisiología , Línea Celular Tumoral , Replicación del ADN , ADN de Neoplasias/genética , Humanos , Masculino , Proteínas de Neoplasias/aislamiento & purificación , Neoplasias de la Próstata/metabolismo , Timidina/metabolismo
12.
Eur Urol Focus ; 5(4): 650-657, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29089252

RESUMEN

BACKGROUND: Guidelines advocate early re-resection for these cancers, although the benefits are unclear and the uniform need is questioned. Here, we compare the outcomes using a large single-center cohort. OBJECTIVES: To compare the outcomes of patients with high-grade non-muscle-invasive bladder cancer (BC) who underwent and who did not undergo re-resection following their initial treatment. DESIGN, SETTING, AND PARTICIPANTS: We identified all eligible patients with a new diagnosis treated between 1994 and 2009 in Sheffield. We annotated these with hospital and registry records. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Primary outcomes were disease-specific and overall survival. Secondary outcomes were the findings at re-resection, rates of muscle invasion, and radical treatment. Statistical tests were two tailed and significance defined as p<0.05. RESULTS AND LIMITATIONS: We identified 932 eligible patients, including 229(25%) who underwent re-resection within 12 wk and 234 (25%) within 3-6 mo after diagnosis. Clinicopathological criteria were similar in patients with and without re-resection. Histological findings on re-resection were no residual cancer in 91 (20%) and BC in 138 (30%: 15 low-grade and 85 high-grade non-muscle-invasive cancers, and 38 muscle-invasive cancers). Patients with re-resection were more frequently diagnosed with muscle invasion (126 [27%] vs 49 [11%], chi-square p<0.001) and more commonly underwent radical treatment (127 [27%] vs 35 [8%], p<0.001) than those without re-resection. A total of 207 patients died from BC, including 46 (22%) with and 161 (78%) without re-resection. Patients who underwent re-resection within 3 mo had significantly higher disease-specific (log rank p=0.009) and overall survival (p<0.001) survival compared with those who did not. Differences were present only for patients with pT1 cancer at diagnosis. CONCLUSIONS: Patients undergoing re-resection within 3 mo of diagnosis were more likely to have histologically identified muscle invasion, were more likely to undergo radical treatment, and had a higher survival rate. The differences were greatest in patients with lamina propria invasion, suggesting the potential to avoid in others. Limitations of our work include retrospective design and selection bias. PATIENT SUMMARY: Patients undergoing re-resection after a diagnosis of high-grade non-muscle-invasive bladder cancer had higher disease-specific and overall survival rates due to more accurate diagnosis and appropriate subsequent radical treatment. Re-resection carries greatest benefit to patients with lamina propria invasion at diagnosis.


Asunto(s)
Cistectomía/métodos , Neoplasias de la Vejiga Urinaria/cirugía , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Reoperación , Estudios Retrospectivos , Medición de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Neoplasias de la Vejiga Urinaria/patología
13.
Bioresour Technol ; 99(15): 6709-24, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18334292

RESUMEN

A number of industries currently produce varying concentrations of heavy metal laden waste streams with significant consequences for any receiving environmental compartment. In recent years, increasing emphasis has been placed on environmental impact minimisation and resulting from this the range and capability of natural and prepared materials capable of heavy metal removal has seen steady development. In particular considerable work has been carried out on the use of both natural materials and their modifications. These natural materials, in many instances are relatively cheap, abundant in supply and have significant potential for modification and ultimately enhancement of their adsorption capabilities. This review paper reviews the current state of research on the use of the naturally occurring material cellulose, its modified forms and their efficacy as adsorbents for the removal of heavy metals from waste streams. Adsorbents based on direct modification of cellulose are evaluated initially and subsequently modifications resulting from the grafting of selected monomers to the cellulose backbone with subsequent functionalisation are assessed. The heavy metal adsorption capacities for these modified cellulose materials were found to be significant and levels of uptake were comparable, in many instances, to both other naturally occurring adsorbent materials and commercial ion exchange type resins. Many of the modified cellulose adsorbents proved regenerable and re-usable over a number of adsorption/desorption cycles allowing recovery of the adsorbed heavy metal in a more concentrated form.


Asunto(s)
Celulosa/química , Metales Pesados/química , Adsorción
15.
Free Radic Biol Med ; 95: 333-48, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26944189

RESUMEN

Reactive oxygen species, such as H2O2, can damage cells but also promote fundamental processes, including growth, differentiation and migration. The mechanisms allowing cells to differentially respond to toxic or signaling H2O2 levels are poorly defined. Here we reveal that increasing external H2O2 produces a bi-phasic response in intracellular H2O2. Peroxiredoxins (Prx) are abundant peroxidases which protect against genome instability, ageing and cancer. We have developed a dynamic model simulating in vivo changes in Prx oxidation. Remarkably, we show that the thioredoxin peroxidase activity of Prx does not provide any significant protection against external rises in H2O2. Instead, our model and experimental data are consistent with low levels of extracellular H2O2 being efficiently buffered by other thioredoxin-dependent activities, including H2O2-reactive cysteines in the thiol-proteome. We show that when extracellular H2O2 levels overwhelm this buffering capacity, the consequent rise in intracellular H2O2 triggers hyperoxidation of Prx to thioredoxin-resistant, peroxidase-inactive form/s. Accordingly, Prx hyperoxidation signals that H2O2 defenses are breached, diverting thioredoxin to repair damage.


Asunto(s)
Peróxido de Hidrógeno/química , Oxidación-Reducción , Peroxirredoxinas/química , Tiorredoxinas/química , Citoplasma/química , Citoplasma/metabolismo , Peróxido de Hidrógeno/metabolismo , Modelos Químicos , Peroxirredoxinas/genética , Especies Reactivas de Oxígeno/química , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal , Tiorredoxinas/metabolismo
16.
Kidney Int ; 61(1 Suppl): S79-84, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11841618

RESUMEN

Pancreatic islet transplantation (PIT) is an attractive alternative to insulin-dependent diabetes treatment but is not yet a clinical reality. The first few days after PIT are characterized by substantial pancreatic islet dysfunction and death. Apoptosis has been documented in PI after extracellular matrix removal, during culture time, after exposure to proinflammatory cytokines, hypoxic conditions before islet revascularization, and rejection. Targeting the apoptosis pathway by adenoviral-mediated gene transfer of the anti-apoptotic Bcl-2 gene exerts a major cytoprotective effect on isolated macaque pancreatic islets. Bcl-2 transfection ex vivo protects islets from apoptosis induced by disruption of the islet extracellular matrix during pancreatic digestion. Additionally, over-expression of Bcl-2 confers long-term, stable protection and maintenance of functional islet mass after transplantation into diabetic SCID mice. Genetic modification of PI also reduced the islet mass required to achieve stable euglycemia. Ex vivo gene transfer of anti-apoptotic genes has potential as a therapeutic approach to both minimize loss of functional islet mass post-transplant and reduce the high islet requirement currently needed for successful stable reversal of insulin-dependent diabetes [1, 2].


Asunto(s)
Citoprotección , Terapia Genética , Trasplante de Islotes Pancreáticos , Islotes Pancreáticos/citología , Animales , Técnicas de Transferencia de Gen , Macaca mulatta , Masculino , Cuidados Posoperatorios , Cuidados Preoperatorios , Factores de Tiempo
17.
Transpl Immunol ; 11(3-4): 335-44, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12967786

RESUMEN

Brief treatment of rhesus macaques with immunotoxin plus 15-deoxyspergualin has yielded exceptional numbers (54%) of stable tolerant kidney allograft recipients, surviving over 6 years without rejection or immunosuppression. An early increase in IL-10 and reduction in IFNgamma distinguished recipients that subsequently became tolerant. Furthermore, analysis suggested that this immune switch was programmed within hours of transplantation. Administering deoxyspergualin within 5 h of surgery gave a higher incidence of tolerance (76%) compared to administration >5 h before or after surgery (11%, P<0.01). Deoxyspergualin inhibits nuclear translocation of activated NF-kappaB through heat shock proteins. Lymph node biopsies from tolerant recipients showed significant reductions in cytoplasmic expression of Hsp70 and RelB and almost complete inhibition of nuclear translocation of both. The early timing effect of deoxyspergualin suggests a crucial limitation to induction of stable tolerance is activation of Hsp-dependent innate responses to damage by ischemia-reperfusion. This was supported by studies in murine kidney reperfusion injury, where deoxyspergualin given 5 h before reperfusion protected renal function and reduced levels of IL-6 and IL-12. The narrow timing window for initiating deoxyspergualin treatment suggests the innate immune system is poised to defeat allograft tolerance induction, so effective blockade of NF-kappaB-mediated innate immunity must be in place early, to enable development of a tolerogenic environment.


Asunto(s)
Guanidinas/uso terapéutico , Inmunotoxinas/uso terapéutico , Macaca mulatta/inmunología , Tolerancia al Trasplante , Animales , Citocinas/antagonistas & inhibidores , Humanos , Tolerancia Inmunológica , Inmunidad Innata/efectos de los fármacos , Trasplante de Riñón/inmunología , Masculino , Ratones , Daño por Reperfusión/patología , Daño por Reperfusión/prevención & control
18.
J AOAC Int ; 87(4): 950-60, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15295890

RESUMEN

StarLink is a genetically modified corn that produces an insecticidal protein, Cry9C. Studies were conducted to determine the variability and Cry9C distribution among sample test results when Cry9C protein was estimated in a bulk lot of corn flour and meal. Emphasis was placed on measuring sampling and analytical variances associated with each step of the test procedure used to measure Cry9C in corn flour and meal. Two commercially available enzyme-linked immunosorbent assay kits were used: one for the determination of Cry9C protein concentration and the other for % StarLink seed. The sampling and analytical variances associated with each step of the Cry9C test procedures were determined for flour and meal. Variances were found to be functions of Cry9C concentration, and regression equations were developed to describe the relationships. Because of the larger particle size, sampling variability associated with cornmeal was about double that for corn flour. For cornmeal, the sampling variance accounted for 92.6% of the total testing variability. The observed sampling and analytical distributions were compared with the Normal distribution. In almost all comparisons, the null hypothesis that the Cry9C protein values were sampled from a Normal distribution could not be rejected at 95% confidence limits. The Normal distribution and the variance estimates were used to evaluate the performance of several Cry9C protein sampling plans for corn flour and meal. Operating characteristic curves were developed and used to demonstrate the effect of increasing sample size on reducing false positives (seller's risk) and false negatives (buyer's risk).


Asunto(s)
Proteínas Bacterianas/química , Toxinas Bacterianas/química , Endotoxinas/química , Harina/análisis , Zea mays/química , Algoritmos , Toxinas de Bacillus thuringiensis , Calibración , Ensayo de Inmunoadsorción Enzimática , Proteínas Hemolisinas , Fosfatos/química , Reproducibilidad de los Resultados
19.
Adv Mind Body Med ; 28(4): 18-33, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25590293

RESUMEN

Current brain research increasingly reveals the underlying mechanisms and processes of human behavior, cognition, and emotion. In addition to being of interest to a wide range of scientists, educators, and professionals, as well as laypeople, brain-based models are of particular value in a clinical setting. Psychiatrists, psychologists, counselors, and other mental health professionals are in need of operational models that integrate recent findings in the physical, cognitive, and emotional domains, and offer a common language for interdisciplinary understanding and communication. Based on individual traits, predispositions, and responses to stimuli, we can begin to identify emotional and behavioral pathways and mental processing patterns. The purpose of this article is to present a brain-path activation model to understand individual differences in decision making and psychopathology. The first section discusses the role of frontal lobe electroencephalography (EEG) asymmetry, summarizes state- and trait-based models of decision making, and provides a more complex analysis that supplements the traditional simple left-right brain model. Key components of the new model are the introduction of right hemisphere parallel and left hemisphere serial scanning in rendering decisions, and the proposition of pathways that incorporate both past experiences as well as future implications into the decision process. Main attributes of each decision-making mechanism are provided. The second section applies the model within the realm of clinical mental health as a tool to understand specific human behavior and pathology. Applications include general and chronic anxiety, depression, paranoia, risk taking, and the pathways employed when well-functioning operational integration is observed. Finally, specific applications such as meditation and mindfulness are offered to facilitate positive functioning.


Asunto(s)
Toma de Decisiones/fisiología , Emociones/fisiología , Salud Mental , Modelos Psicológicos , Encéfalo/fisiología , Humanos , Meditación , Atención Plena
20.
J Vasc Surg Venous Lymphat Disord ; 2(4): 355-61, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26993537

RESUMEN

BACKGROUND: Venous leg ulcers (VLUs) are a prevalent and morbid disease that consumes considerable health care resources. Estimates place the total costs for treatment of VLU at 1% of health care budgets in many industrialized countries. Unfortunately, there is little contemporary information on the total cost of treating VLU in the United States, particularly in a wound center staffed by vascular specialists. The purpose of this study was to define the actual cost of treating VLU and to identify factors influencing costs. METHODS: A cohort of 84 patients with active VLU (Clinical, Etiologic, Anatomic, and Pathologic class 6 disease) who were treated in a wound center by five vascular surgeons with a minimum follow-up of 6 months (median, 368 days; range, 336-483 days) was retrospectively studied. Actual costs (not charges) were obtained for outpatient and inpatient facility, visiting nurse services, and our physician practice group to yield true cost. The proportion of healed VLUs and time to complete healing were determined to calculate time to healing as well as ulcer-free intervals. Calculations of cost/ulcer-free days and cost to complete healing for the entire follow-up period were carried out as well as univariate analysis of factors affecting cost. RESULTS: The mean total cost of treating VLU during this follow-up period was $15,732. A total of 50 patients (60%) healed their VLUs without recurrence in a mean time of 122 days (range, 6-379 days) at a cost of $10,563 (range, $430-$50,967). This translated to $86/day of treatment to heal an ulcer, resulting in a cost of $42/ulcer-free day. In comparison, the total cost was threefold higher at $33,907 (range, $390-$132,730) for the patients (n = 17; 20%) who did not heal their VLUs. Significant contributing factors included outpatient facility fees ($10,332) and visiting nurse services ($11,365) related to extended treatment of the open VLU. Patients who had a recurrence of their VLU (n = 17; 20%) during the follow-up period had a total cost of $12,760. Inpatient admission for wound-related issues increased total cost to $33,629. Nearly two thirds of admissions were for treatment of cellulitis with intravenous antibiotics. VLUs treated with surgical intervention did not significantly increase total cost ($12,304 vs $19,503; P > .05) but significantly reduced recurrence rates (34% vs 5%). There were three outliers who experienced complications after treatment of outflow obstruction that dramatically increased the total cost to $71,526. CONCLUSIONS: This economic analysis demonstrates the high true costs associated with modern treatment of VLU by aggressive medical and surgical techniques. Inpatient and outpatient facility fees, physician fees, and visiting nurse payments all contribute to the cumulative tally that results in these staggering direct costs for treatment of VLUs. The daily cost of treatment that accrues for the ongoing care of VLU patients until they are healed provides an economic rationale for initiatives that advance approaches seeking to provide more rapid wound healing. Our analysis also highlights the significant costs associated with treatment of infections and complications encountered in aggressive surgical interventions for patients with extensive chronic central venous occlusive disease. More aggressive early outpatient treatment of infections and refined criteria for selection of outflow stenting candidates may reduce total cost by preventing complications while improving outcomes.

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