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1.
BMC Emerg Med ; 24(1): 67, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38627619

RESUMO

BACKGROUND: Anaphylaxis is a potentially life-threatening allergic reaction, with presentations to emergency departments (EDs) increasing across Australia. Understanding the features of those presenting with anaphylaxis and aspects related to its optimal clinical management across the admission, treatment and discharge settings is needed to minimise its impact. We aimed to evaluate the nature and management of presentations related to anaphylaxis across two Australian EDs. METHODS: Retrospective audit of paediatric and adult patients presenting to a community or tertiary level ED with anaphylaxis from 1 May 2018 to 30 April 2019. Data extracted from medical records included demographic characteristics, causative agents, clinical features, treatments administered across community, ambulance or ED settings, as well as post-discharge care arrangements including provision of Adrenaline Auto-Injector (AAI) and Allergy/Anaphylaxis Action Plan (AAP). RESULTS: A total of 369 (107 paediatric and 262 adult) ED presentations were identified. A total of 94 (36%) adult and 46 (43%) paediatric patients received pre-hospital adrenaline, with a further 91 (35%) adult and 29 (27%) paediatric patients receiving a dose of adrenaline in the ED. The most commonly administered treatment in ED were corticosteroids, given to 157 (60%) adult and 55 (51%) paediatric patients. Among those requiring an AAI for discharge, 123/210 (59%) adult and 57/91 (63%) of paediatric patients left hospital with an AAI. In contrast, among those requiring an allergy/anaphylaxis action plan (AAP) on discharge, 61/206 (30%) adult and 30/90 (33%) of paediatric patients left hospital with one. Factors associated with an increased likelihood of receiving AAI on discharge in paediatric and adult patients included receipt of any adrenaline, receipt of two or more doses of adrenaline, and longer duration of hospital stay. Adults presenting within business hours were more likely to be discharged with AAI, but no such difference was observed for paediatric patients. Similar findings were evident for provision of AAP on discharge. CONCLUSION: These findings demonstrate the need to improve assessment and treatment in the ED. In particular, the observed large variability in provision of AAI and AAP on discharge presents opportunities to explore strategies to improve awareness and provision of these critical components of post-discharge care.


Assuntos
Anafilaxia , Adulto , Humanos , Criança , Anafilaxia/tratamento farmacológico , Anafilaxia/etiologia , Assistência ao Convalescente , Estudos Retrospectivos , Austrália , Alta do Paciente , Serviço Hospitalar de Emergência , Epinefrina/uso terapêutico
2.
AJNR Am J Neuroradiol ; 38(4): 691-695, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28126745

RESUMO

BACKGROUND AND PURPOSE: Posttraumatic migraines are common after mild traumatic brain injury. The purpose of this study was to determine if a specific axonal injury pattern underlies posttraumatic migraines after mild traumatic brain injury utilizing Tract-Based Spatial Statistics analysis of diffusion tensor imaging. MATERIALS AND METHODS: DTI was performed in 58 patients with mild traumatic brain injury with posttraumatic migraines. Controls consisted of 17 patients with mild traumatic brain injury without posttraumatic migraines. Fractional anisotropy and diffusivity maps were generated to measure white matter integrity and were evaluated by using Tract-Based Spatial Statistics regression analysis with a general linear model. DTI findings were correlated with symptom severity, neurocognitive test scores, and time to recovery with the Pearson correlation coefficient. RESULTS: Patients with mild traumatic brain injury with posttraumatic migraines were not significantly different from controls in terms of age, sex, type of injury, or neurocognitive test performance. Patients with posttraumatic migraines had higher initial symptom severity (P = .01) than controls. Compared with controls, patients with mild traumatic brain injury with posttraumatic migraines had decreased fractional anisotropy in the corpus callosum (P = .03) and fornix/septohippocampal circuit (P = .045). Injury to the fornix/septohippocampal circuit correlated with decreased visual memory (r = 0.325, P = .01). Injury to corpus callosum trended toward inverse correlation with recovery (r = -0.260, P = .05). CONCLUSIONS: Injuries to the corpus callosum and fornix/septohippocampal circuit were seen in patients with mild traumatic brain injury with posttraumatic migraines, with injuries in the fornix/septohippocampal circuit correlating with decreased performance on neurocognitive testing.


Assuntos
Imagem de Tensor de Difusão/métodos , Transtornos de Enxaqueca/etiologia , Transtornos de Enxaqueca/patologia , Síndrome Pós-Concussão/patologia , Adulto , Anisotropia , Corpo Caloso/diagnóstico por imagem , Corpo Caloso/lesões , Corpo Caloso/patologia , Feminino , Fórnice/diagnóstico por imagem , Fórnice/lesões , Fórnice/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos de Enxaqueca/diagnóstico por imagem , Testes Neuropsicológicos , Síndrome Pós-Concussão/diagnóstico por imagem , Análise de Regressão , Substância Branca/lesões , Adulto Jovem
5.
Int J Radiat Biol ; 78(8): 671-9, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12194750

RESUMO

PURPOSE: To investigate the relationship between the susceptibility of B-chronic lymphoid leukaemia (B-CLL) cells to DNA damage-induced apoptosis, the kinetics of DNA strand-break rejoining, and chromosome damage after exposure to ionizing irradiation. MATERIALS AND METHODS: Lymphocytes from B-CLL patients were gamma-irradiated in vitro with 0.2-5 Gy and stimulated by Staphylococcus aureus cowan I (SAC I) for estimation of chromosomal damage. Induction of apoptosis after irradiation was studied in 50 patients by two methods: morphological characterization of apoptotic cells after fluorescent staining (Hoechst), and specific quantification of mono- and oligonucleosomes in cytoplasmic cell fractions (ELISA assay). Morphological chromosome damage was scored in the first cell generation after irradiation (13 patients). In parallel, the kinetics of DNA single-strand break rejoining were investigated by the alkaline comet assay (12 patients). RESULTS: Ionizing irradiation did not induce apoptosis in lymphocytes from a subset of B-CLL patients. The results suggest that B-CLL cells resistant to radiation-induced apoptosis could repair DNA strand-breaks more rapidly and showed a higher level of chromosome aberrations than radiation-sensitive B-CLL cells. CONCLUSION: Each of three biological effects observed (apoptosis, kinetics of DNA single-strand-break repair, chromosomal damage) might be explained by different modifications occurring in irradiated B-CLL cells. Their convergence strongly suggests that resistance to apoptotic death initiation by DNA damage may be impeded by a rapid engaging of the DNA repair mechanisms. The higher level of chromosome aberrations observed in these cells suggests that the type of DNA repair system involved may generate inaccurate repair.


Assuntos
Apoptose , Aberrações Cromossômicas , Reparo do DNA , Leucemia Linfoide/metabolismo , Leucemia Linfoide/radioterapia , Linfócitos B/efeitos da radiação , Ensaio Cometa , DNA/metabolismo , Dano ao DNA , Relação Dose-Resposta à Radiação , Ensaio de Imunoadsorção Enzimática , Humanos , Radiação Ionizante , Fatores de Tempo
6.
Med Arh ; 55(2): 71-4, 2001.
Artigo em Servo-Croata (Latino) | MEDLINE | ID: mdl-11769043

RESUMO

In this study anatomical variations of shape, size and relation of the kidneys have been analyzed. It has been carried out on 33 pairs of the human adult kidneys of both sex, randomly chosen. It has determined size, width and thickness of the kidney. The kidneys are very variable organs in the size and in the shape. Reduced largeness of the kidney and enlarged kidney are forms of variations of size. Reduced largeness of the left kidney has been found in 18.18%, and enlarged one in 24.24%. Reduced largeness of the right kidney has been found in 24.24% and enlarged one in 21.21%. Two types of the shape were presented: fetal lobularness and lobarnes of the kidney. The shape of left kidney was variable in 39.39%, fetal lobularness was present in 33.33%, and lobarness in 6.06%. The shape of right kidney was variable in 30.30%, foetal lobularness was present in 27.27%, and lobarness in 3.03%. All parameters that determine the size of kidneys show statistically high positive correlation. It means that mutual functional dependence is present, what made it possible from the size of right kidney calculating the size of left kidney and opposite.


Assuntos
Rim/anatomia & histologia , Adulto , Antropometria , Feminino , Humanos , Masculino
7.
Leuk Lymphoma ; 42(6): 1173-80, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11911398

RESUMO

The ubiquitin system regulates diverse biological processes such as DNA replication and repair, biogenesis of ribosome, peroxisome and nucleosome, cell cycle, stress response and signal transduction pathways. Thus, the reported role of the ubiquitin system in apoptotic death control as well the alteration of its control in carcinogenesis should come as no surprise. Indeed, we and other groups have reported that the ubiquitin system is involved in apoptotic cell death of normal human lymphocytes and that this control is altered in B lymphocytes derived from chronic lymphocytic leukemia patients (B-CLL), rendering these malignant cells hypersensitive to specific inhibition of protein degradation/processing through proteasomal function. This approach recently allowed us to demonstrate that the stability of the tumor suppressor and pro-apoptotic protein p53 is differentially regulated in B-CLL versus normal lymphocytes and that this difference might at least partly explain the impaired response of B-CLL lymphocytes to apoptotic death activation. These results strongly suggest an imbalance in p53 regulation in B-CLL cells that leads to a variable response to DNA damage and constitutively expressed chromosomal instability. The question we and others would like to address is whether this alteration, or more likely a subset of alterations of the ubiquitin-proteasome pathway, is specific to B-CLL malignancy or if it is a hallmark of cancer cells in general. In either case, a better understanding of the ubiquitin-dependent control of apoptosis should pave the way towards a methodological approach for in vitro development of discriminating treatments which may be of potential usefulness in clinical trials of B-CLL.


Assuntos
Apoptose , Cromossomos Humanos/genética , Leucemia Linfocítica Crônica de Células B/genética , Proteína Supressora de Tumor p53/metabolismo , Ubiquitina/metabolismo , Cisteína Endopeptidases/fisiologia , Dano ao DNA , Humanos , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Complexos Multienzimáticos/fisiologia , Complexo de Endopeptidases do Proteassoma
8.
Med Arh ; 54(3): 185-6, 2000.
Artigo em Servo-Croata (Latino) | MEDLINE | ID: mdl-11117019

RESUMO

In this report is described anomally of arteria ulnaris topography. By anatomical dissection of cadaver of a male new-born, we noticed the ulnar artery, on the right arm, layed superficially, under of fascia antebrachi. The ulnar artery was the branch of brachial artery, and it run directly from the brachial artery, in the level of interepicondilar line, to the madial part of the distal end of antebrachium, and it attached by ulnar nerve before they entered Guyon's canal.


Assuntos
Artéria Ulnar/anormalidades , Humanos , Recém-Nascido , Masculino , Artéria Ulnar/anatomia & histologia
9.
Regul Toxicol Pharmacol ; 32(2): 144-55, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11067771

RESUMO

Occupational exposure limits (OELs) for individual substances are established on the basis of the available toxicological information at the time of their promulgation, expert interpretation of these data in light of industrial use, and the framework in which they sit. In the United Kingdom, the establishment of specific OELs includes the application of uncertainty factors to a defined starting point, usually the NOAEL from a suitable animal study. The magnitude of the uncertainty factors is generally determined through expert judgment including a knowledge of workplace conditions and management of exposure. PBPK modeling may help in this process by informing on issues relating to extrapolation between and within species. This study was therefore designed to consider how PBPK modeling could contribute to the establishment of OELs. PBPK models were developed for chloroform (mouse and human) and carbon tetrachloride (rat and human). These substances were chosen for examination because of the extent of their toxicological databases and availability of existing PBPK models. The models were exercised to predict the rate (chloroform) or extent (carbon tetrachloride) of metabolism of these substances, in both rodents and humans. Monte Carlo analysis was used to investigate the influence of variability within the human and animal model populations. The ratio of the rates/extent of metabolism predicted for humans compared to animals was compared to the uncertainty factors involved in setting the OES. Predictions obtained from the PBPK models indicated that average rat and mouse metabolism of carbon tetrachloride and chloroform, respectively, are much greater than that of the average human. Application of Monte Carlo analysis indicated that even those people who have the fastest rates or most extensive amounts of metabolism in the population are unlikely to generate the levels of metabolite of these substances necessary to produce overt toxicity in rodents. This study highlights the value that the use of PBPK modeling may add to help inform and improve toxicological aspects of a regulatory process.


Assuntos
Tetracloreto de Carbono/farmacocinética , Tetracloreto de Carbono/toxicidade , Clorofórmio/farmacocinética , Clorofórmio/toxicidade , Administração por Inalação , Animais , Tetracloreto de Carbono/administração & dosagem , Clorofórmio/administração & dosagem , Feminino , Exposição por Inalação , Concentração Máxima Permitida , Camundongos , Camundongos Endogâmicos , Modelos Biológicos , Método de Monte Carlo , Ratos , Medição de Risco
10.
Leuk Lymphoma ; 38(5-6): 499-504, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10953970

RESUMO

The ubiquitin-proteasome-dependent proteolytic system has been reported to regulate apoptotic cell death in many experimental cell models. We recently found that B-CLL (chronic lymphocytic leukemia) lymphocytes are hypersensitive to apoptotic death activation through specific inhibition of proteasome function by lactacystin. Lactacystin efficiently activates apoptotic death process in B-CLL lymphocytes at doses at which no apoptotic effect can be observed in normal human lymphocytes in which 10-fold higher doses of lactacystin are required to weakly induce apoptosis. This hypersensitivity of B-cell CLL may be a result of an altered ubiquitin pathway and proteasomal proteolysis in these malignant cells, and this alteration could be specific for this malignancy. Together with other published works, these results suggest that lactacystin, though not per se a discriminatory inhibitor of the ubiquitinated protein processing/degradation, can nonetheless be discriminatory in the apoptotic cell response between B-CLL and normal lymphocytes: the property that promises efficacy in clinical trials of B-cell CLL. This hypothesis is documented by the fact that lymphocytes from patients in complete remission become resistant to lactacystin-induced apoptosis as normal lymphocytes do.


Assuntos
Apoptose/fisiologia , Cisteína Endopeptidases/fisiologia , Leucemia Linfocítica Crônica de Células B/patologia , Leucemia Linfocítica Crônica de Células B/fisiopatologia , Complexos Multienzimáticos/fisiologia , Ubiquitinas/fisiologia , Acetilcisteína/análogos & derivados , Acetilcisteína/farmacologia , Acetilcisteína/uso terapêutico , Apoptose/efeitos dos fármacos , Inibidores de Cisteína Proteinase/farmacologia , Inibidores de Cisteína Proteinase/uso terapêutico , Humanos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Complexo de Endopeptidases do Proteassoma , Transdução de Sinais
11.
Blood ; 96(1): 269-74, 2000 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-10891461

RESUMO

We recently reported increased sensitivity of B-cell chronic lymphocytic leukemia (B-CLL) lymphocytes to apoptotic death activation by the proteasome-specific inhibitor lactacystin. Here, we show that only specific-not nonspecific-proteasomal inhibitors can discriminate between malignant and normal lymphocytes in inducing the apoptotic death response. Indeed, lactacystin and its active metabolite clasto-lactacystin beta-lactone induced apoptotic death in CLL but not in normal lymphocytes. This difference was completely abolished when tripeptide aldehydes such as MG132 or LLnL (which can also inhibit calpains) were used as less specific proteasomal inhibitors. Moreover, B-CLL cells exhibited a constitutive altered ubiquitin-proteasome system, including a threefold higher chymotrypsin-like proteasomal activity and high levels of nuclear ubiquitin-conjugated proteins compared with normal lymphocytes. Interestingly, B-CLL cells also displayed altered proteolytic regulation of wild-type p53, an apoptotic factor reported to be a substrate for the ubiquitin-proteasome system. Nuclear wild-type p53 accumulated after lactacystin treatment used at the discriminating concentration in malignant, but not in normal, lymphocytes. In contrast, p53 was stabilized by MG132 or LLnL in malignant and normal cells undergoing apoptosis, indicating that in normal lymphocytes p53 is regulated mainly by calpains and not by the ubiquitin-proteasome system. This work raises the possibility that two different proteolytic pathways controlling p53 stability may be pathologically imbalanced. This could result in modification of apoptosis control, since in CLL-lymphocytes a highly upregulated ubiquitin-proteasome system, which controls p53 stability among other apoptotic factors, was correlated with an increased propensity of these cells to apoptosis triggered by lactacystin.


Assuntos
Apoptose/fisiologia , Leucemia Linfocítica Crônica de Células B/imunologia , Linfócitos/imunologia , Proteínas Nucleares , Proteínas Proto-Oncogênicas c-bcl-2 , Proteína Supressora de Tumor p53/metabolismo , Ubiquitinas/fisiologia , Acetilcisteína/análogos & derivados , Acetilcisteína/farmacologia , Adenosina Trifosfatases/sangue , Cisteína Endopeptidases/sangue , Inibidores de Cisteína Proteinase/farmacologia , Humanos , Leucemia Linfocítica Crônica de Células B/sangue , Linfócitos/citologia , Linfócitos/fisiologia , Complexos Multienzimáticos/sangue , Proteínas de Neoplasias/sangue , Complexo de Endopeptidases do Proteassoma , Proteínas Proto-Oncogênicas/sangue , Proteínas Proto-Oncogênicas c-mdm2 , Valores de Referência , Proteína X Associada a bcl-2 , Receptor fas/sangue
12.
Oncogene ; 19(23): 2731-8, 2000 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-10851073

RESUMO

Bloom's syndrome (BS) is a rare human autosomal recessive disorder characterized by an increased risk to develop cancer of all types. BS cells are characterized by a generalized genetic instability including a high level of sister chromatid exchanges. BS arises through mutations in both alleles of the BLM gene which encodes a 3' - 5' DNA helicase identified as a member of the RecQ family. We developed polyclonal antibodies specific for the NH2- and COOH-terminal region of BLM. Using these antibodies, we analysed BLM expression during the cell cycle and showed that the BLM protein accumulates to high levels in S phase, persists in G2/M and sharply declines in G1, strongly suggestive of degradation during mitosis. The BLM protein is subject to post-translational modifications in mitosis, as revealed by slow migrating forms of BLM found in both demecolcine-treated cells and in mitotic cells isolated from non-treated asynchronous populations. Phosphatase treatment indicated that phosphorylation events were solely responsible for the appearance of the retarded moieties, a possible signal for subsequent degradation. Together, these results are consistent with a role of BLM in a replicative (S phase) and/or post-replicative (G2 phase) process. Oncogene (2000).


Assuntos
Adenosina Trifosfatases/genética , Síndrome de Bloom/genética , DNA Helicases/genética , Regulação Enzimológica da Expressão Gênica , Complexo de Endopeptidases do Proteassoma , Adenosina Trifosfatases/metabolismo , Síndrome de Bloom/enzimologia , Síndrome de Bloom/metabolismo , DNA Helicases/metabolismo , Demecolcina/farmacologia , Fase G2 , Células HeLa , Humanos , Mitose , Peptídeo Hidrolases/metabolismo , Fosforilação , Inibidores de Proteases/farmacologia , Processamento de Proteína Pós-Traducional , RecQ Helicases , Fase S , Células Tumorais Cultivadas
13.
Exp Cell Res ; 257(1): 48-57, 2000 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-10854053

RESUMO

The ubiquitination of nuclear proteins activated in human lymphocytes undergoing radiation-induced apoptosis and the subsequent downstream proteasomal protein processing, shown to be involved in apoptotic death control, may be dependent on an amino-terminal sequence identity of ubiquitin target proteins, the "N-end rule" pathway. Here we report that this selective pathway controls radiation-induced apoptosis and that it is involved in the initiation of this type of cell death. Dipeptide competitors of protein ubiquitination/processing dependent solely on the basic amino-terminal residues (type I) efficiently inhibited the radiation-induced apoptotic death phenotype, indicating that only the substrates of ubiquitination with basic NH2-terminal amino acids are involved in apoptotic death control. This selective inhibition was followed by an early, overall but also target-specific inhibition of ubiquitination and by an activation and stabilization of poly(ADP-ribose) polymerase (PARP) that occurs through inhibition of ubiquitination of its cleaved form (85 kDa). Interestingly, caspases-3 and -7 were not activated following irradiation, further suggesting that PARP cleavage may be regulated by an N-end rule pathway in a caspase-independent manner. These results highly suggest involvement of this subset of the ubiquitin system in the apoptotic death control and in the specific regulation of PARP activity.


Assuntos
Apoptose/fisiologia , Linfócitos/patologia , Linfócitos/fisiologia , Poli(ADP-Ribose) Polimerases/fisiologia , Ubiquitinas/fisiologia , Aminoácidos , Apoptose/efeitos da radiação , Células Cultivadas , Humanos , Linfócitos/efeitos da radiação , Fragmentos de Peptídeos
14.
Br J Haematol ; 105(3): 752-7, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10354141

RESUMO

Ubiquitin-proteasome-dependent protein processing appears to be an essential component in the control of radiation-induced apoptosis in human lymphocytes. This control is altered in chronic lymphocytic leukaemia (CLL), compared to that of normal human lymphocytes which mainly showed high apoptotic values after irradiation, but in some cases no sensitivity was observed. Interestingly, lactacystin activated the apoptotic pathway in both radio-resistant and sensitive CLL cells, at doses which had no effect in normal cells where significantly higher concentrations were required. Therefore the resistance of some CLL cells to apoptosis initiation by radiation does not correlate to observed increased sensitivity to lactacystin. The nuclear level of the transcription factor NF-kappaB or the cytoplasmic level of IkappaBalpha remained unaltered upon irradiation or lactacystin CLL cells treatment, suggesting that the activity of the other factors involved in apoptotic death control were altered through proteasomal inhibition. These results strongly suggest an essential role of the ubiquitin system in apoptotic cell death control in CLL lymphocytes. The inhibition of proteasome-ubiquitin-dependent processing could be a discriminatory apoptotic stimulus between normal versus malignant lymphocytes and therefore might potentially be of use in this specific human pathology.


Assuntos
Acetilcisteína/análogos & derivados , Inibidores de Cisteína Proteinase/uso terapêutico , Leucemia Linfocítica Crônica de Células B/patologia , Acetilcisteína/uso terapêutico , Idoso , Apoptose/efeitos dos fármacos , Western Blotting , Humanos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Linfócitos/patologia , Linfócitos/efeitos da radiação , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/farmacologia
15.
Concise international chemical assessment document ; 15
Monografia em Inglês | WHO IRIS | ID: who-42199
16.
Ann Occup Hyg ; 42(8): 531-40, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9838866

RESUMO

The control of exposure to hazardous substances in the workplace has traditionally focused on uptake via the inhalation route. Control of skin uptake has generally been considered for solids and liquids but the potential for uptake from vapours and gases has received relatively little attention. The current work was undertaken to establish a methodology to study the dermal uptake from vapours and to provide new and comparative information on a range of substance vapours. Groups of human volunteers were exposed to a small range of substances either 'whole body' or via the skin only. Substances (xylene, toluene, tetrahydrofuran [THF], methyl ethyl ketone [MEK] and 1-methoxypropan-2-ol [M2P]) were selected on the basis of their predicted dermal uptake from the vapour phase; their industrial use and potential for occupational exposure; the existence of a health-based occupational exposure limit; the availability of an analytical technique(s) for the substance and/or metabolite(s); and as representatives of chemical classes. Exposures were for four hours generally at the level of the UK Occupational Exposure Standard. Uptake was assessed by monitoring of parent or metabolite in blood, single breath or urine following exposure. Uptake of xylene, toluene and THF vapours via the skin under the conditions of this study was estimated to contribute around 1-2% of the body burden received following whole body (including inhalation) exposure. MEK showed more uptake via the skin, contributing around 3-3.5% of the body burden. Most dermal uptake was seen for the glycol ether M2P for which estimates of between 5-10% of whole body exposure body burden were obtained. The results of this and other studies indicate that uptake of vapours across the skin can occur but that for some substances (e.g., xylene, toluene, THF) this is likely to contribute little to the body burden. For other substances, such as the glycol ethers, skin uptake from vapours may be an important contributor to total uptake, particularly in situations where respiratory protective equipment is used to control inhalation exposure.


Assuntos
Exposição Ocupacional , Pele/metabolismo , Solventes/farmacocinética , Administração Cutânea , Adulto , Carga Corporal (Radioterapia) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Roupa de Proteção , Valores de Referência , Absorção Cutânea , Volatilização
17.
Br J Cancer ; 77(7): 1103-7, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9569046

RESUMO

Apoptosis can be triggered by cytotoxic agents and radiation currently used in cancer treatment. However, the apoptotic response appears to vary between cell types (normal or transformed) and between types of malignancy. Thus, irradiation induces apoptosis in normal human lymphocytes but not in lymphocytes derived from a subset of chronic lymphocytic leukaemia (CLL). Moreover, in this subset, spontaneous apoptosis is inhibited by irradiation. Why irradiation does not allow the initiation of the apoptotic death pathway could be explained, at least in part, and in agreement with recent findings on experimental models, by the activation of the transcriptional factor NF-kappaB, which is able to inhibit apoptotic cell response. Low doses (at which no effect is observed with normal human lymphocytes) of the highly specific proteasome inhibitor lactacystin are sufficient to trigger apoptosis in these malignant cells. Proteasome inhibition by lactacystin prevents the nuclear translocation of both p50 and p65 NF-kappaB subunits and sensitizes these cells to apoptosis by tumour necrosis factor (TNF)-alpha treatment. As this subset of CLL is totally resistant to any treatment, proteasome inhibition by lactacystin provides a new therapeutic approach to be explored, considering the sensitivity of malignant CLL-derived lymphocytes to be quite different from that of normal human lymphocytes.


Assuntos
Acetilcisteína/análogos & derivados , Apoptose/efeitos dos fármacos , Cisteína Endopeptidases/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Leucemia Linfocítica Crônica de Células B/fisiopatologia , Linfócitos/efeitos dos fármacos , Complexos Multienzimáticos/metabolismo , NF-kappa B/metabolismo , Proteínas de Neoplasias/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Acetilcisteína/farmacologia , Apoptose/efeitos da radiação , Resistencia a Medicamentos Antineoplásicos , Humanos , Leucemia Linfocítica Crônica de Células B/sangue , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Linfócitos/efeitos da radiação , Complexo de Endopeptidases do Proteassoma , Tolerância a Radiação , Fator de Necrose Tumoral alfa/metabolismo
18.
Cytometry ; 32(1): 44-50, 1998 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-9581623

RESUMO

Fine-needle samples of 75 non-Hodgkin's lymphomas were investigated for apoptosis immediately and after 24 h of culture after in vitro irradiation (2 Gy, 10 Gy, and nonirradiated controls). Apoptotic cells were simultaneously quantified by fluorescence microscopic enumeration of apoptotic cells using Hoechst 33342 staining, and by flow cytometric detection of sub-G1 peak cells. The nonirradiated controls showed a similar mean percent apoptotic cells using both methods, analyzed immediately (9% by morphology vs. 10% by flow) or after 24 h of culture (40% by morphology vs. 41% by flow). In the irradiated samples, the mean percent apoptotic cells quantified by morphology was higher than by flow cytometry (64% by morphology vs. 55% by flow after 2 Gy irradiation, and 71% vs. 58% after 10 Gy). The results of the two methods were correlated, although large differences were seen between the techniques in individual tumors. In our system, flow cytometric sub-G1 peak analysis appears to underestimate apoptosis. Of these two methods, we find the Hoechst morphology method to be more reliable for quantitation of apoptosis utilizing fresh fine-needle sample material, in that discrimination of apoptotic cells from debris is easier and that both early and late apoptotic cells are detectable.


Assuntos
Apoptose , Benzimidazóis , Citometria de Fluxo/métodos , Corantes Fluorescentes , Linfoma não Hodgkin/patologia , Humanos , Estudos Prospectivos
19.
Radiother Oncol ; 46(2): 185-91, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9510046

RESUMO

PURPOSE: Prospective investigation of spontaneous and in vitro radiation-induced apoptosis to predict early response to palliative radiotherapy in patients with non-Hodgkin's lymphomas. PATIENTS AND METHODS: Fine-needle sampling was performed in 28 tumor sites (26 patients) and yielded adequate cell numbers in 27 cases. Apoptotic cells were counted by fluorescence microscopy immediately after sampling and after 24-h culture (spontaneous apoptosis) and 24 h after 2- and 10-Gy in vitro irradiation (radiation-induced apoptosis). Early response to low-dose in vivo radiotherapy (mostly 4 Gy in two fractions over 3 days) was evaluated 15 days after treatment. RESULTS: The tumor response rates at 15 days were 11 (39%) complete responses, nine (32%) responses of greater than 50% reduction in volume, six (21%) responses of less than 50% reduction in volume and two (7%) cases of no response. Tumors achieving complete or major response after in vivo irradiation had higher percentages of apoptotic cells after in vitro irradiation, while no significant differences in terms of spontaneous apoptosis were observed between responders and non-responders. CONCLUSION: Spontaneous and in vitro radiation-induced apoptosis can be easily and quickly assessed on cells obtained by fine-needle sampling of non-Hodgkin's lymphoma lesions. The present results suggest that in vitro radiation-induced apoptosis could be used as a predictive assay of early response to low-dose in vivo irradiation in patients with non-Hodgkin's lymphomas.


Assuntos
Apoptose/efeitos da radiação , Linfoma não Hodgkin/patologia , Linfoma não Hodgkin/radioterapia , Tolerância a Radiação , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha , Relação Dose-Resposta à Radiação , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
20.
Ann Occup Hyg ; 41(4): 455-65, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9284647

RESUMO

A number of studies have been conducted in recent years investigating the potential effects on various health endpoints of the combination of noise and a variety of different industrial substances. This review indicates that the information available in both animals and humans on this subject is limited particularly with respect to assessing occupational risk. Most studies have focused on auditory effects in animals, although investigations have been performed for other toxicological endpoints. For some substances, notably toluene, the information from animals studies does suggest an interaction but these were performed only at exposure levels to both noise and chemicals which were each individually ototoxic. Single simultaneous exposure to noise and styrene did not result in any enhancement of auditory impairment above that produced by noise or styrene alone. Single simultaneous exposure to noise and carbon monoxide (CO), however, showed some evidence of enhancement of ototoxicity beyond that produced by noise or carbon monoxide alone, although only at high atmospheric concentrations of CO. When 1,3-dinitrobenzene was administered parentally at neurotoxic dose levels with continuous noise exposure, there was an increased severity of effects in the brain stem. Combined exposure to noise and lead and/or cadmium resulted in histopathological heart lesions of undefined severity, a finding which was not observed for either of those agents in isolation. Dermal exposure to dimethylformamide and noise or inhalation exposure to xylene and noise resulted in some biochemical changes in cardiac muscle which were of doubtful toxicological significance. In developing mice, there was evidence that combined exposure to cadmium sulphate and noise caused an increased incidence of external and skeletal malformations but only at dose levels of cadmium which would have induced developmental effects. Overall, for each of these chemicals and endpoints observed there is a suggestion of some interaction with noise exposure. From the data that are currently available, however, inferences cannot be drawn on whether or not interactions would have occurred at lower, more occupationally relevant, levels of exposure. A number of studies have investigated human populations exposed to both noise and industrial chemicals. Due to confounding factors, however, it was concluded that these data were inadequate for assessing the combined effects of noise and chemical exposure on hearing.


Assuntos
Exposição Ambiental/efeitos adversos , Substâncias Perigosas/efeitos adversos , Sensibilidade Química Múltipla/etiologia , Ruído/efeitos adversos , Animais , Relação Dose-Resposta a Droga , Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Feminino , Humanos , Masculino , Camundongos/embriologia , Exposição Ocupacional/efeitos adversos , Gravidez , Solventes/efeitos adversos , Solventes/toxicidade
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