RESUMO
There are an estimated 1 billion cases of superficial fungal infection globally. Fungal pathogens form biofilms within wounds and delay the wound healing process. Miconazole and terbinafine are commonly used to treat fungal infections. They induce the accumulation of reactive oxygen species (ROS) in fungi, resulting in the death of fungal cells. ROS are highly reactive molecules, such as oxygen (O2), superoxide anion (O2â¢-), hydrogen peroxide (H2O2) and hydroxyl radicals (â¢OH). Although ROS generation is useful for killing pathogenic fungi, it is cytotoxic to human keratinocytes. To the best of our knowledge, the effect of miconazole and terbinafine on HaCaT cells has not been studied with respect to intracellular ROS stimulation. We hypothesized that miconazole and terbinafine have anti-wound healing effects on skin cells when used in antifungal treatment because they generate ROS in fungal cells. We used sulforhodamine B protein staining to investigate cytotoxicity and 2',7'-dichlorofluorescein diacetate to determine ROS accumulation at the 50% inhibitory concentrations of miconazole and terbinafine in HaCaT cells. Our preliminary results showed that topical treatment with miconazole and terbinafine induced cytotoxic responses, with miconazole showing higher cytotoxicity than terbinafine. Both the treatments stimulated ROS in keratinocytes, which may induce oxidative stress and cell death. This suggests a negative correlation between intracellular ROS accumulation in keratinocytes treated with miconazole or terbinafine and the healing of fungi-infected skin wounds.
Assuntos
Peróxido de Hidrogênio , Miconazol , Humanos , Peróxido de Hidrogênio/farmacologia , Queratinócitos , Miconazol/metabolismo , Miconazol/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Terbinafina/metabolismo , Terbinafina/toxicidadeRESUMO
Chinese knotweed (Persicaria chinensis) is of ecological and economic importance as a high-risk invasive species and a traditional medicinal herb. However, the insects associated with P. chinensis pollination have received scant attention. As a widespread invasive plant we would expect P. chinensis to be associated with a diverse group of insect pollinators, but lack of taxonomic identification capacity is an impediment to confirm this expectation. In the present study we aimed to elucidate the insect pollinators of P. chinensis in peninsular Malaysia using DNA barcoding. Forty flower visitors, representing the range of morphological diversity observed, were captured at flowers at Ulu Kali, Pahang, Malaysia. Using Automated Barcode Gap Discovery, 17 morphospecies were assigned to 23 species representing at least ten families and four orders. Using the DNA barcode library (BOLD) 30% of the species could be assigned a species name, and 70% could be assigned a genus name. The insects visiting P. chinensis were broadly similar to those previously reported as visiting Persicaria japonica, including honey bees (Apis), droneflies (Eristalis), blowflies (Lucilia) and potter wasps (Eumedes), but also included thrips and ants.
Assuntos
Código de Barras de DNA Taxonômico , Insetos/genética , Polinização/fisiologia , Polygonaceae/fisiologia , Animais , Insetos/classificação , Insetos/fisiologia , MalásiaRESUMO
OBJECTIVES: The principal objective of a healthy living environment is to improve the quality of everyday life. Visually impaired persons (VIPs) encounter many difficulties in everyday life through a series of barriers, particularly in relation to public toilets. This study aimed to explore the concerns of VIPs in accessing public toilets, and identify methods for improvement. Considerations about user participation are also discussed. STUDY DESIGN: Adopting a case study approach, VIPs were invited to participate in the research process. METHODS: In addition to in-depth interviews and field visits, models and a simulated full-scale environment were produced to facilitate the VIPs to voice their opinions. RESULTS: The key findings indicate that the design of public toilets for promoting public health should be considered and tackled from a three-level framework: plain, line and point. Governments, professionals and the public need to consider the quality of public toilets in terms of policy, implementation and management. CONCLUSIONS: VIPs have the right to access public toilets. Governments and professionals should respect the particular needs and concerns of VIPs. A three-level framework (plain, line and point) is required to consider the needs of VIPs in accessing public toilets, and user participation is a good way to reveal the actual needs of VIPs.
Assuntos
Planejamento Ambiental , Avaliação das Necessidades , Logradouros Públicos , Pessoas com Deficiência Visual , Participação da Comunidade , Feminino , Hong Kong , Humanos , Masculino , Pesquisa QualitativaRESUMO
Clozapine is considered the most effective antipsychotic for schizophrenia, but it can cause neutropenia and even agranulocytosis. We describe the first case in Hong Kong involving the use of filgrastim, a recombinant form of human granulocyte colony-stimulating factor, to enable clozapine continuation therapy for a severely ill patient with treatment-resistant schizoaffective disorder who developed recurrent neutropenia after almost 20 years of continuous clozapine therapy. Therefore, clinical vigilance is important, regardless of clozapine treatment duration. Filgrastim can facilitate long-term clozapine therapy in patients with clozapine-induced neutropenia.
Assuntos
Agranulocitose , Antipsicóticos , Clozapina , Neutropenia , Humanos , Clozapina/efeitos adversos , Filgrastim/uso terapêutico , Neutropenia/induzido quimicamente , Neutropenia/tratamento farmacológico , Antipsicóticos/efeitos adversos , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Fator Estimulador de Colônias de Granulócitos/farmacologia , Agranulocitose/induzido quimicamente , Agranulocitose/tratamento farmacológicoRESUMO
OBJECTIVES: This study aims to examine the rates of anxiety, depression, and posttraumatic stress disorder (PTSD) after hospital discharge among COVID-19 survivors and to determine the associated risk factors. METHODS: Adult COVID-19 survivors discharged from hospitals between March 2020 and March 2021 were asked to complete a questionnaire at 4 weeks after discharge. The Chinese version of the 22-item Impact of Event Scale - Revised (IES-R) was used to measure symptoms of PTSD. The 9-item Patient Health Questionnaire (PHQ-9) was used to assess symptoms of major depressive disorder. The 7-item Generalised Anxiety Disorder Scale (GAD-7) was used to measure symptoms of generalised anxiety disorder. The rates of anxiety, depression, and PTSD among discharged patients were determined, as were associations between psychosocial factors and outcome measures and predictors for moderate-tosevere symptoms of anxiety, depression, and PTSD. RESULTS: 96 men and 103 women aged 18 to 81 years returned the completed questionnaire. 12.1% to 20.1% of them reported symptoms of PTSD, anxiety, or depression. Higher symptom severity was associated with higher perceived life threat, lower emotional support, lower disease severity upon admission, and longer hospital stay. Women had more PTSD symptoms than men, particularly when knowing someone under quarantine. CONCLUSION: COVID-19 survivors with higher perceived life threat, lower emotional support, lower disease severity upon admission, and longer hospital stay were associated with higher severity of symptoms of PTSD, anxiety, and depression. Timely intervention should provide to at-risk survivors.
Assuntos
COVID-19 , Transtorno Depressivo Maior , Transtornos de Estresse Pós-Traumáticos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Ansiedade/epidemiologia , Transtornos de Ansiedade/complicações , Transtornos de Ansiedade/epidemiologia , COVID-19/epidemiologia , Depressão/epidemiologia , Transtorno Depressivo Maior/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos de Estresse Pós-Traumáticos/etiologia , Sobreviventes , Adulto JovemRESUMO
OBJECTIVE: To compare predictive validity of the Wilson Sims Fall Risk Assessment Tool (WSFRAT) with that of the Morse Fall Scale (MFS) in psychogeriatric inpatients. METHODS: Psychogeriatric patients from Shatin Hospital, Tai Po Hospital, Castle Peak Hospital, and United Christian Hospital who had fall incident between April 2019 and April 2020 were identified. Their fall risks were assessed by the WSFRAT and the MFS, and their falls incidents during hospitalisation were recorded. Patients were classified as having high fall risk when their MFS score was ≥45 and when their WSFRAT score was ≥7. Sensitivity, specificity, and positive and negative predictive values of the two scales were calculated. RESULTS: We identified 183 (90 male and 93 female) psychogeriatric patients aged ≥65 years who had fall incident and were assessed by both the WSFRAT and the MFS during the study period. Among the 183 patients, four sustained a fall during hospital stay, giving a prevalence of 2.19%. All four patients were classified as having high risk of fall by WSFRAT, but only two of them were classified so by MFS. The sensitivity of WSFRAT was 100%, which was higher than the 50% by MFS, but specificity of MFS was higher than that of WSFRAT (45.81% vs 54.75%). CONCLUSION: WSFRAT is a better fall risk assessment scale for psychiatric inpatients than MFS, because of higher sensitivity (100% vs 50%). It has items specific to psychiatric patients and should replace MFS in psychiatric settings.
Assuntos
Acidentes por Quedas/estatística & dados numéricos , Psiquiatria Geriátrica , Hospitalização , Pacientes Internados/estatística & dados numéricos , Idoso , Feminino , Humanos , Masculino , Medição de Risco , Fatores de RiscoRESUMO
This report describes a 68-year-old Chinese man who was diagnosed with Good syndrome 6 years after initial presentation when he underwent thymectomy. He presented with recurrent pneumonia, diarrhoea, weight loss, and visual symptoms. Extensive examination for anaemia and neutropenia was done, yet no conclusive diagnosis could be derived. During his last admission for pneumonia, his history of AB thymoma suggested the possibility of Good syndrome. Immunological testing revealed low T cells, absent B cells, and low immunoglobulin M and immunoglobulin G levels. Moreover, he had histologically identified cytomegalovirus pneumonia, cytomegalovirus colitis, and fundoscopic features of cytomegalovirus retinitis. He was treated with a 2-week course of intravenous ganciclovir, lifelong oral valganciclovir, and monthly immunoglobulin infusion. It took 6 years for the diagnosis to be established, therefore, early attention and vigorous search for such potentially treatable conditions in post-thymectomy patients presenting with recurrent infections is recommended.
Assuntos
Infecções por Citomegalovirus/etiologia , Diarreia/etiologia , Pneumonia/etiologia , Timectomia/efeitos adversos , Transtornos da Visão/etiologia , Idoso , Humanos , Masculino , Recidiva , Síndrome , Timoma/cirurgia , Neoplasias do Timo/cirurgiaRESUMO
Antimicrobial resistance remains a serious problem that results in high mortality and increased healthcare costs globally. One of the major issues is that resistant pathogens decrease the efficacy of conventional antimicrobials. Accordingly, development of novel antimicrobial agents and therapeutic strategies is urgently needed to overcome the challenge of antimicrobial resistance. A potential strategy is to kill pathogenic microorganisms via the formation of reactive oxygen species (ROS). ROS are defined as a number of highly reactive molecules that comprise molecular oxygen (O2), superoxide anion (O2â¢-), hydrogen peroxide (H2O2) and hydroxyl radicals (â¢OH). ROS exhibit antimicrobial actions against a broad range of pathogens through the induction of oxidative stress, which is an imbalance between ROS and the ability of the antioxidant defence system to detoxify ROS. ROS-dependent oxidative stress can damage cellular macromolecules, including DNA, lipids and proteins. This article reviews the antimicrobial action of ROS, challenges to ROS hypothesis, work to solidify ROS-mediated antimicrobial lethality hypothesis, recent developments in antimicrobial agents using ROS as an antimicrobial strategy, safety concerns related to ROS, and future directions in ROS research.
Assuntos
Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , DNA Bacteriano/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Animais , Humanos , Estresse OxidativoRESUMO
OBJECTIVE: To compare the tensile biomechanical properties of age-matched adult human knee articular cartilage exhibiting distinct stages of degenerative or osteoarthritic deterioration and to determine the relationships between tensile properties and biochemical and structural properties hypothesized to underlie functional biomechanical deterioration. METHODS: Age-matched articular cartilage samples, obtained from the lateral and medial femoral condyles (LFC and MFC), exhibited (1) minimal fibrillation, characteristic of normal aging (NLA), (2) overt fibrillation associated with degeneration (DGN), or (3) overt fibrillation associated with osteoarthritis (OA). DGN samples were from knees that exhibited degeneration but not osteophytes while OA samples were from fragments removed during total knee arthroplasty. Cartilage samples were analyzed for tensile properties, cell and matrix composition, and histopathological structure. RESULTS: Differences in tensile, compositional and surface structural properties were indicative of distinct stages of cartilage degeneration, early (OA) advanced (DGN) and late (OA) with early degenerative changes in NLA samples being more advanced in the MFC than the LFC, including higher surface fibrillation, lower intrinsic fluorescence, and lower mechanical integrity. The transition from early to advanced degeneration involved a diminution in mechanical function, surface integrity, and intrinsic fluorescence. The transition from advanced to late degeneration involved an increase in cartilage water content, an increase in degraded collagen, and loss of collagen. CONCLUSIONS: These results provide evidence of coordinated mechanical dysfunction, collagen network remodeling, and surface fibrillation. Even in the cartilage of knees exhibiting overt fibrillation but not extensive erosions characteristic of clinical osteoarthritis, most features of advanced cartilage degeneration were present.
Assuntos
Densidade Óssea/fisiologia , Cartilagem Articular/patologia , Colágeno/fisiologia , Fêmur/patologia , Osteoartrite/fisiopatologia , Resistência à Tração/fisiologia , Fenômenos Biomecânicos , Cartilagem Articular/metabolismo , Feminino , Fluorescência , Humanos , Masculino , Osteoartrite/metabolismoRESUMO
BACKGROUND: Patients with major depressive disorder are found to show selective attention biases towards mood-congruent information. Although previous studies have identified various structural changes in the brains of these patients, it remains unclear whether the structural abnormalities are associated with these attention biases. In this study, we used voxel-based morphometry (VBM) to explore the structural correlates of attention biases towards depression-related stimuli. METHOD: Seventeen female patients with major depressive disorder and 17 female healthy controls, matched on age and intelligence, underwent magnetic resonance imaging (MRI). They also performed positive-priming (PP) and negative-priming (NP) tasks involving neutral and negative words that assessed selective attention biases. The reaction time (RT) to a target word that had been attended to or ignored in a preceding trial was measured on the PP and NP tasks respectively. The structural differences between the two groups were correlated with the indexes of attention biases towards the negative words. RESULTS: The enhanced facilitation of attention to stimuli in the PP task by the negative valence was only found in the depressed patients, not in the healthy controls. Such attention biases towards negative stimuli were found to be associated with reduced gray-matter concentration (GMC) in the right superior frontal gyrus, the right anterior cingulate gyrus and the right fusiform gyrus. No differential effect in inhibition of attention towards negative stimuli in the NP task was found between the depressed patients and the healthy controls. CONCLUSIONS: Specific structural abnormalities in depression are associated with their attention biases towards mood-congruent information.
Assuntos
Afeto/fisiologia , Atenção/fisiologia , Encéfalo/fisiopatologia , Transtorno Depressivo Maior/fisiopatologia , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Semântica , Adulto , Mapeamento Encefálico , Sinais (Psicologia) , Dominância Cerebral/fisiologia , Feminino , Lobo Frontal/fisiopatologia , Giro do Cíngulo/fisiopatologia , Humanos , Sistema Límbico/fisiopatologia , Pessoa de Meia-Idade , Rede Nervosa/fisiopatologia , Inventário de Personalidade/estatística & dados numéricos , Psicometria , Tempo de Reação/fisiologia , Leitura , Valores de Referência , Lobo Temporal/fisiopatologiaRESUMO
In acinar cells from rat salivary glands, cholinergic agonists cause oscillations in cytoplasmic free calcium concentration, which then drive oscillations of cell volume that reflect oscillating cell solute content and fluid secretion. By quantitative fluorescence ratio microscopy of an intracellular indicator dye for sodium, it has now been shown that large amplitude oscillations of sodium concentration were associated with the calcium and cell volume oscillations. Both calcium and sodium oscillations were dependent on the continued presence of calcium in the extracellular medium and were abolished by the specific sodium-potassium adenosine triphosphatase inhibitor ouabain. Thus, calcium oscillations in salivary acinar cells, by modulating the activities of ion transport pathways in the plasma membrane, can cause significant oscillations of monovalent ions that may in turn feed back to regulate calcium oscillations and fluid secretion.
Assuntos
Cálcio/fisiologia , Glândula Parótida/fisiologia , Sódio/fisiologia , Animais , Cloretos/fisiologia , Citosol/fisiologia , Técnicas In Vitro , Masculino , Ouabaína/farmacologia , Periodicidade , Potássio/fisiologia , Ratos , Ratos Endogâmicos , Equilíbrio HidroeletrolíticoRESUMO
Bullous pemphigoid (BP) is an autoimmune blistering disease primarily of the elderly, characterized by the development of urticarial plaques surmounted by subepidermal blisters and the deposition of immunoglobulins and complement at the basement membrane zone (BMZ). Immunologically, it is characterized by the development of autoantibodies targeting two structural proteins of the hemidesmosomes, BP180 (collagen XVII) and BP230. BP230 is intracellular protein of the hemidesmosomal plaque, while BP180 is a transmembrane protein with a collagenous extracellular domain. The weight of experimental evidence indicates that BP180 is the primary target of the pathogenic autoantibodies. Autoantibodies are of both the IgG or IgE class, and their binding in the skin triggers complement activation, mast cell degranulation and the accumulation of inflammatory cells, including eosinophils, mast cells, and neutrophils. Release of proteases from these inflammatory cells results in cleavage of the BMZ and blister formation. While the initial triggers of autoantibody production remain obscure, a better understanding of the pathomechanisms of blister formation will lead to the development of new therapeutic strategies.
Assuntos
Autoanticorpos/imunologia , Autoantígenos/imunologia , Autoimunidade , Penfigoide Bolhoso/imunologia , Animais , Modelos Animais de Doenças , HumanosRESUMO
To date nearly all clinical trials of Alzheimer's disease (AD) therapies have failed. These failures are, at least in part, attributable to poor endpoint choice and to inadequate recruitment criteria. Recently, focus has shifted to targeting at-risk populations in the preclinical stages of AD thus improved predictive markers for identifying individuals likely to progress to AD are crucial to help inform the sample of individuals to be recruited into clinical trials. We focus on hippocampal volume (HV) and assess the added benefit of combining HV and rate of hippocampal atrophy over time in relation to disease progression. Following the cross-validation of previously published estimates of the predictive value of HV, we consider a series of combinations of HV metrics and show that a combination of HV and rate of hippocampal atrophy characterises disease progression better than either measure individually. Furthermore, we demonstrate that the risk of disease progression associated with HV metrics does not differ significantly between clinical states. HV and rate of hippocampal atrophy should therefore be used in tandem when describing AD progression in at-risk individuals. Analyses also suggest that the effects of HV metrics are constant across the continuum of the early stages of the disease.
Assuntos
Doença de Alzheimer/diagnóstico por imagem , Hipocampo/diagnóstico por imagem , Idoso , Doença de Alzheimer/patologia , Progressão da Doença , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Tomografia por Emissão de PósitronsRESUMO
BACKGROUND: The prevalence of chronic obstructive pulmonary disease (COPD) is rising in many parts of the world. This is a study of risk factors for COPD in Chinese patients in Hong Kong. DESIGN: Case-control study matched by sex and age (+/-5 years). METHODS: A total of 289 consecutive patients with COPD were recruited from out-patient clinics while healthy controls were recruited from two sources: random population and community centres for senior citizens. All patients and controls underwent a questionnaire-based interview and spirometry. RESULTS: The mean ages of COPD patients and controls were 71.1 +/- 9.4 and 67.5 +/- 9.3 years, respectively. The male to female ratio of COPD patients was 5 to 1. Smoking was found to be the most important determinant for COPD, followed by poor education and low body mass index adjusted for confounders. A dose-dependent relationship was found between the risk of COPD and pack-years smoked. Place of birth, exposure to environmental tobacco smoke and a history of asthma and tuberculosis were not associated with increased risk of COPD. CONCLUSION: Despite a progressive reduction in prevalence, smoking remains the most important predictor of COPD in Hong Kong. Greater anti-smoking efforts are warranted.
Assuntos
Povo Asiático , Doença Pulmonar Obstrutiva Crônica/etnologia , Doença Pulmonar Obstrutiva Crônica/etiologia , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Hong Kong , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fumar/efeitos adversos , Fatores SocioeconômicosRESUMO
OBJECTIVE: To assess cognitive performance in elderly depressed patients following treatment for 6 months. Remission rate of depression after 6 months of treatment was calculated. METHODS: The study was performed in a consecutive group of patients aged ≥ 65 years with late-onset depression. Severity of depression was assessed by the Hamilton Depression Scale, cognitive performance by the Hong Kong Montreal Cognitive Assessment, and functional level by the Instrumental Activities of Daily Living Scale. RESULTS: A total of 52 patients were recruited. In all, 28 (53.8%) were found to have cognitive impairment at baseline and 8 (28.6%) of them had improvement after 6 months. This cognitively impaired group was older and had a lower Instrumental Activities of Daily Living Scale score. The remission rate of depression was 61.5%. CONCLUSIONS: Cognitive impairment constituted a stable feature in a considerable number of elderly patients with depression. About two-thirds of patients achieved remission of depression after 6 months of treatment.
Assuntos
Transtornos Cognitivos/etiologia , Transtorno Depressivo/psicologia , Atividades Cotidianas/psicologia , Idoso , Idoso de 80 Anos ou mais , Antidepressivos/uso terapêutico , Transtorno Depressivo/tratamento farmacológico , Feminino , Seguimentos , Avaliação Geriátrica/métodos , Hong Kong , Humanos , Masculino , Escalas de Graduação PsiquiátricaRESUMO
A young girl had tibial osteotomies at age 14 for genu valgum and then had recurrent tibial cysts over a number of years. Hypocalcemia and hyperphosphatemia were first noted at age 21. The diagnosis of pseudohypoparathyroidism was made at age 28, when elevated plasma PTH was detected. Clinical and biochemical features, including a PTH response test and assay of RBC Gs, established the diagnosis of pseudohypoparathyroidism type 1b. Failure to suppress plasma PTH with vitamin D therapy led to an exacerbation of her cystic bone disease; there were widespread lytic lesions radiologically, most of which took up [99mTc]diphosphonate on bone scan. Microradioscopy revealed evidence of resorption of phalangeal tufts. Bone biopsy showed osteitis fibrosa cystica. During an orthopedic procedure, trabecular bone fragments were taken from her right humerus, and bone-derived cells cultured using an explant technique. The cultured cells were osteoblast-like in morphology, fully responsive to PTH, cholera toxin, forskolin, and PGE1 in vitro, and had an alkaline phosphatase and osteocalcin response to 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. Following this examination of skeletal responsiveness, attempts were made to suppress the elevated plasma PTH levels and symptomatic bone disease by optimizing therapy with oral 1,25-(OH)2D3. When bone pain associated with the cystic bone disease failed to resolve, the patient underwent total parathyroidectomy, following which the bone pain gradually resolved. This is the first direct demonstration of PTH responsiveness in cultured bone cells in the syndrome of pseudohypoparathyroidism with osteitis fibrosa cystica.
Assuntos
Osso e Ossos/efeitos dos fármacos , Osteíte Fibrosa Cística/metabolismo , Osteoblastos/efeitos dos fármacos , Hormônio Paratireóideo/farmacologia , Pseudo-Hipoparatireoidismo/metabolismo , Adenilil Ciclases/metabolismo , Adulto , Osso e Ossos/citologia , Osso e Ossos/metabolismo , Células Cultivadas , Feminino , Humanos , Osteoblastos/metabolismo , Osteocalcina/metabolismo , Hormônio Paratireóideo/metabolismo , SíndromeRESUMO
Bone cells derived from human trabecular explants display osteoblastic features. We examined the modulation of alkaline phosphatase activity and cAMP production as the result of exposing trabecular explants to physiologic concentrations of dexamethasone for 4 weeks during cellular outgrowth and subculture. Cells treated with dexamethasone were observed to grow generally more slowly than control cells. Cells appeared larger and more polygonal, and staining for alkaline phosphatase was more intense in the dexamethasone-exposed cultures. There was a progressive increase in cellular PTH responsiveness with increasing duration of exposure of cells to dexamethasone. Cells grown for 6 weeks in 3 x 10(-8) M dexamethasone had a 10-fold increase in PTH-stimulated cyclic AMP accumulation. Dexamethasone-treated cells also had a significantly increased alkaline phosphatase activity. 1,25-(OH)2D3-stimulated alkaline phosphatase activity was increased approximately 20-fold. cAMP responses were significantly increased to PTH (21.7-fold), PGE1 (2.67-fold), and forskolin (4.81-fold), but not to cholera toxin. Dexamethasone-treated cells also had a mean decrease in 1,25-(OH)2D3-stimulated osteocalcin production to 26.2% of control values (p less than 0.001). Hydrocortisone treatment gave rise to similar effects but of smaller magnitude than those of dexamethasone. Testosterone did not have a significant effect on alkaline phosphatase activity or cAMP production. Skin fibroblasts showed a significant enhancement of alkaline phosphatase activity in response to dexamethasone, but of a much smaller magnitude than in bone cells. The phenotypic changes induced by long-term culture in dexamethasone are consistent with the promotion of a more differentiated osteoblastic phenotype.
Assuntos
Osso e Ossos/efeitos dos fármacos , Dexametasona/farmacologia , Adenilil Ciclases/metabolismo , Fosfatase Alcalina/metabolismo , Osso e Ossos/citologia , Osso e Ossos/metabolismo , Contagem de Células/efeitos dos fármacos , Células Cultivadas , AMP Cíclico/metabolismo , Humanos , Hidrocortisona/farmacologia , Osteoblastos/efeitos dos fármacos , Osteocalcina/metabolismo , Hormônio Paratireóideo/metabolismo , Ligação Proteica , Testosterona/farmacologia , Fatores de TempoRESUMO
Pseudohypoparathyroidism (PHP) is characterized by a lack of response to parathyroid hormone (PTH); however, normal skeletal responsiveness to PTH in some patients with PHP type Ia was previously suggested on the basis of clinical observations. To test this hypothesis, we measured cyclic adenosine monophosphate (cAMP) production in response to various agonists in bone-derived osteoblast-like (OBL) cells from trabecular explants obtained from an iliac crest biopsy of a 25-year-old woman with PHP. The patient was proved to have PHP type Ia on the basis of Albright's hereditary osteodystrophy and decreased activity of stimulatory guanine nucleotide-binding protein (Gs) in erythrocytes. Responsiveness of the patient's OBL cells was compared with OBL cells from eight subjects aged 18-39 years who had no evidence of metabolic bone disease. OBL cells from the patient responded to the following agonists (expressed in multiples of elevation of cAMP, stimulated/basal, mean +/- SE, n = 3): PTH, 3.8 +/- 0.3; forskolin, 8.2 +/- 0.2; and cholera toxin, 56.8 +/- 10.0. These responses were not significantly different from those of control OBL cells: PTH, 4.5 +/- 1.1 (range 2.4-7.5); forskolin, 7.7 +/- 1.4; and cholera toxin, 57.9 +/- 16.2. The normal cholera toxin response indicated the presence of functional Gs. Bone cells from patients with PHP type Ia may exhibit a normal PTH receptor-coupled adenylyl cyclase system in vitro despite clinical evidence of impaired hormone-responsive adenylyl cyclase in other tissues, including the kidney. Skeletal responsiveness to PTH may explain the long periods of spontaneous normocalcemia observed in this patient.
Assuntos
Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Hormônio Paratireóideo/farmacologia , Pseudo-Hipoparatireoidismo/metabolismo , Adenilil Ciclases/metabolismo , Adolescente , Adulto , Fosfatase Alcalina/metabolismo , Osso e Ossos/patologia , Células Cultivadas , AMP Cíclico/biossíntese , Feminino , Humanos , Masculino , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteocalcina/biossíntese , Pseudo-Hipoparatireoidismo/classificação , Pseudo-Hipoparatireoidismo/patologiaRESUMO
The role of severe acute respiratory syndrome (SARS) coronavirus as an enteric pathogen was investigated in a cohort of 142 patients with SARS who were treated with a standard treatment protocol. Data from daily hematological, biochemical, radiological, and microbiological investigations were prospectively collected, and the correlation of these findings with diarrhea was retrospectively analyzed. Sixty-nine patients (48.6%) developed diarrhea at a mean (+/- standard deviation [SD]) of 7.6+/-2.6 days after the onset of symptoms. The diarrhea was most severe at a mean (+/-SD) of 8.8+/-2.4 days after onset, with a maximum frequency of 24 episodes per day (median, 5 episodes; range, 3-24 episodes). A higher mean virus load in nasopharyngeal specimens obtained on day 10 after the onset of symptoms was significantly associated with the occurrence of diarrhea (3.1 log10 vs. 1.8 log10 copies/mL; P=.01) and mortality (6.2 vs. 1.7 log10 copies/mL; P<.01). However, diarrhea was not associated with mortality. The lung and the gastrointestinal tract may react differently to SARS coronavirus infection. Additional investigation of the role of SARS coronavirus in the pathogenesis of diarrhea in patients with SARS should be conducted.