Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 127
Filtrar
1.
J Appl Microbiol ; 131(1): 499-512, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33325600

RESUMO

AIMS: To develop a protocol for environmental sampling to detect parvoviruses of dogs and cats in the environment. METHODS AND RESULTS: Environmental contamination was carried out using different dilutions of parvovirus-contaminated materials; further field samplings were performed in areas in which clinical cases of parvovirus infections were present. Sterile cotton swabs and sponges for microbial surface sampling were used. Viruses were detected in these samples with different methods: conventional PCR, nested PCR and real-time PCR, detecting viral DNA; virus isolation, detecting infectious virus; and a commercial rapid enzyme immunoassay, detecting viral antigen. No substantial differences were observed in the two sampling methods, although the sponge was more convenient for sampling rough surfaces. Molecular assays were the most sensitive methods, identifying even very low amounts of viral DNA (up to 10 copies of viral DNA/10 µl of sample). Virus isolation and the rapid test detected the viruses only at the highest viral concentrations, both in the experimental setting and field conditions. CONCLUSIONS: Environmental sampling and molecular protocols were effective in detecting environmental contamination with parvoviruses. SIGNIFICANCE AND IMPACT OF THE STUDY: The protocol will be useful to identify possible sources of infection and to assess the efficacy of disinfection protocols in the environment.


Assuntos
Doenças do Gato/virologia , Doenças do Cão/virologia , Microbiologia Ambiental , Infecções por Parvoviridae/veterinária , Parvovirus/isolamento & purificação , Animais , Antígenos Virais/imunologia , Gatos , DNA Viral/genética , Cães , Ensaio de Imunoadsorção Enzimática , Infecções por Parvoviridae/virologia , Parvovirus/genética , Parvovirus/imunologia , Reação em Cadeia da Polimerase
2.
J Neurol Sci ; 382: 29-35, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-29111013

RESUMO

Mutations in OPA1 are responsible of 32-89% cases of Autosomal Dominant Optic Atrophy (ADOA). OPA1 ADOA usually presents in childhood with bilateral, progressive visual loss due to retinal ganglion cells neurodegeneration, but environmental factors are supposed to influence onset and phenotype. Sixty Italian OPA1 mutations carriers (fifty-two symptomatic), belonging to thirteen families, underwent neuro-ophthalmologic evaluation. Visual acuity (n=60) and Optical Coherence Tomography (OCT) (n=12) were compared in missense mutations (OPA-M) versus haploinsufficiency-inducing mutations (OPA-H) and correlated with age. Presence of plus phenotypes was investigated. We found four known mutations, the most common being missense c.1034G>A, and a new missense mutation, c1193A>C, the latter in a 54-yrs old female with late-onset phenotype. Visual acuity, colour sensitivity, and optic disc atrophy were sensitive indicators of disease. OCT RNFL thickness was reduced in OPA1 compared to controls. OPA-M showed worst visual acuity than OPA-H, but not more frequent plus-phenotype, observed only in four OPA-H patients. In both groups, visual acuity worsened with age. Our data confirm worst vision in OPA-M, but not increased plus-phenotype. Since most patients belonged to nine families from south-eastern Sicily (a famous region for the cult of St. Lucy, patron of the blinds) local genetic and environmental factors might have accounted for the low occurrence of plus-phenotypes.


Assuntos
GTP Fosfo-Hidrolases/genética , Mutação de Sentido Incorreto , Atrofia Óptica Autossômica Dominante/diagnóstico por imagem , Atrofia Óptica Autossômica Dominante/genética , Tomografia de Coerência Óptica , Adulto , Fatores Etários , Estudos de Coortes , Família , Feminino , Estudos de Associação Genética , Heterozigoto , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Atrofia Óptica Autossômica Dominante/fisiopatologia , Fenótipo , Acuidade Visual , Adulto Jovem
4.
Int J Biol Markers ; 22(2): 154-8, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17549671

RESUMO

The variation between different PSA assays seems to influence the interpretation of individual PSA values and the clinical decisions about prostate cancer. One reason for this variability could be the different reactivity of antibodies for the various molecular forms of serum PSA; as a result, samples containing the same amount of tPSA but different proportions of fPSA can produce very different values. In this study, serum samples were collected prospectively from 152 consecutive patients referred to 2 institutions (Regional Hospital, Venice, 90 subjects; San Bortolo Hospital, Vicenza, 62 subjects) for PSA elevation and/or symptoms. Serum samples were assessed according to the manufacturers' instructions on the following 2 analyzers: the Immulite 2000 assay (Diagnostic Products Corporation, Los Angeles, USA), which measures tPSA and fPSA, and the ADVIA Centaur (Bayer Diagnostics, Tarrytown, USA), which assays tPSA and cPSA. cPSA values were transformed into fPSA by the equation fPSA=tPSA-cPSA. When taking Immulite tPSA and f/tPSA values as 100%, ADVIA Centaur values were 92.6% and 122%, respectively, which means that 20% of patients would be classified differently according to the traditional biopsy cutoff. In conclusion, there are considerable differences between the 2 methods, which could affect clinical decisions.


Assuntos
Antígeno Prostático Específico/sangue , Neoplasias da Próstata/diagnóstico , Biópsia , Humanos , Masculino , Próstata/citologia , Próstata/patologia , Curva ROC , Análise de Regressão , Reprodutibilidade dos Testes
5.
G Ital Med Lav Ergon ; 29(3 Suppl): 698-700, 2007.
Artigo em Italiano | MEDLINE | ID: mdl-18409911

RESUMO

To compare data obtained in a pilot study (2002) which evaluated the risk from exposure to stress and burnout in health care workers, the same three subjective questionnaires were administered: the Job Content Questionnaire (JCQ), the State-Trait Anxiety Inventory (STAI), the Maslach Burnout Inventory (MBI). The evaluation considered 294 workers employed in eight units: two of the six previous units were reorganized in four subunits. Preliminary data showed that questionnaires' scores have a concordant trend in the different units, as observed in 2002, confirming the validity of the instruments adopted. Results indicated a decreased level of the perceived stress in all the units, especially in the Third Division. We can hypothesize that the new organization, workers' turnover during the 5 years and the effect due to individual variables could have contribute to the observed variation. No significant associations, compared to 2002, between questionnaires' scores and task were found. Further evaluations, including measurement of objective parameters, will be carried out to complete the follow-up study and to determine which variables could have a role in the variation of the levels of stress and burnout's subjective perception.


Assuntos
Esgotamento Profissional/epidemiologia , Pessoal de Saúde , Doenças Profissionais/epidemiologia , Adulto , Feminino , Seguimentos , Humanos , Masculino , Estresse Psicológico/epidemiologia , Inquéritos e Questionários
6.
J Anim Sci ; 84(11): 3133-42, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17032809

RESUMO

This work was undertaken to assess the long-term impacts of a ruminal transponder, used for electronic identification, on ruminal motility and on health and performance of cattle, as well as to study the electromagnetic effects on ruminal bacteria in vitro. A passive transponder (51.4 g, 67 x 17 mm) was delivered into the forestomachs of 8 calves, 32 bulls, 10 heifers, and 40 dairy cows. Final readability was 87.5% in calves, 96.9% in bulls, 90% in heifers, and 100% in cows at 481, 360, 650, and 601 d, respectively, after transponder administration. The transponder did not affect production or reproduction of cows over a 2-yr period, or performance of bulls, or mortality compared with control animals. Chewing movements per bolus were lower (P <0.01) in treated animals than in controls (49.6 vs. 52.2, 51.2 vs. 63.6, and 57.0 vs. 59.7 for bulls, heifers, and cows, respectively). Regurgitation frequency (number of boluses/10 min) tended to be greater in treated cattle: 12.4 vs. 11.3 (P = 0.07), 11.3 vs. 10.6, and 11.3 vs. 10.7 (P = 0.08) for bulls, heifers, and cows, respectively. Rumination patterns of calves fitted with transponders within the first weeks of life were similar to controls. During the experiment, 43 treated animals (8 calves, 29 bulls, and 6 cows) were slaughtered. Thirty transponders were localized in the reticulum (3 calves, 24 bulls, and 3 cows), 11 in the rumen (4 calves, 4 bulls, and 3 cows), and 2 were not recovered (1 calf and 1 bull). Within the calves, 57% of the boluses were found in the rumen. In 8 reticula (2 calves and 6 bulls) and 1 rumen (1 cow), an impression left by physical contact of the transponder was observed, although histological examination did not reveal specific lesions in the mucosa of the dystrophic areas. In strained, whole ruminal contents incubated in vitro, pH values were lower after 24 and 48 h (P <0.001) of continuous exposure to an electromagnetic field induced by the transponder-reading system. After 48 h of incubation, total bacterial numbers and NH3-N concentration were greater (P <0.001) in exposed flasks than in controls. These data indicate that the transponder may alter, via mechanical action, the reticuloruminal mucosa and rumination patterns. Furthermore, the transponder may increase, via its electromagnetic action, the growth rate and metabolic activity of ruminal bacteria.


Assuntos
Sistemas de Identificação Animal/veterinária , Bovinos/fisiologia , Campos Eletromagnéticos/efeitos adversos , Rúmen/microbiologia , Envelhecimento , Sistemas de Identificação Animal/instrumentação , Animais , Comportamento Alimentar/fisiologia , Feminino , Masculino , Rúmen/fisiologia
7.
J Clin Virol ; 37(4): 244-7, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17005444

RESUMO

BACKGROUND AND OBJECTIVES: Human herpesvirus-6 (HHV-6) is the causative agent of exanthem subitum. Both HHV-6 variants, A and B, have been associated with central nervous system (CNS) diseases, suggesting a wide neuropathogenic potential. We describe a case of recurrent bilateral anterior optic neuritis with HHV-6 active infection associated with clinical relapses. CASE REPORT: A 23-year old woman presented with progressive visual impairment, bilateral papillitis and painful ocular movements. Nested polymerase chain reaction (PCR) for DNA viruses, HHV-6 variant specific real time quantitative PCR, serological analysis and retrotranscription PCR (RT-PCR) for HHV-6 mRNA transcripts were performed. Nested PCR in PBMC and CSF samples was negative for all viruses but positive for HHV-6 DNA, subtyped as HHV-6B. The disease had a relapsing/remitting course. During relapses PBMC samples remained positive for HHV-6 DNA, and HHV-6 active infection was confirmed by the presence of anti-HHV-6 IgM and of HHV-6 U27 mRNA transcript. High viremia levels and relapses were overlapping. After the last relapse, the patient was successfully treated with gancyclovir. CONCLUSIONS: The case reported here suggests a possible association of HHV-6 in bilateral optic neuritis. HHV-6 could be monitored when bilateral optic neuritis is identified, in order to establish an appropriate antiviral therapy.


Assuntos
Infecções por Herpesviridae/virologia , Herpesvirus Humano 6/isolamento & purificação , Neurite Óptica/virologia , Adulto , DNA Viral/análise , DNA Viral/genética , Feminino , Infecções por Herpesviridae/diagnóstico , Infecções por Herpesviridae/epidemiologia , Humanos , Neurite Óptica/diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa
8.
Int J Biol Markers ; 21(1): 1-5, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16711507

RESUMO

The free-to-total prostate-specific antigen ratio (F/T PSA) is associated with the presence of prostate cancer and is thus used as an indicator for suspicion of prostate cancer and as a determinant for biopsy. We reviewed a recent retrospective series of 966 consecutive prostate biopsies where F/T PSA was blindly determined and did not influence biopsy indication. We simulated the association of F/T PSA with biopsy outcome and its impact as a biopsy determinant. When adopting an F/T PSA cutoff of 10%, 13%, 16% or 20% among random sextant biopsies in the 4-10 ng/mL total PSA range, the sensitivity was 15%, 37%, 55% and 72% and the specificity 89%, 80%, 64% and 44%, respectively. Using F/T PSA as a biopsy determinant, from 1.7 to 2.6 cancer biopsies would have been delayed to avoid 10 benign biopsies. As this balance is not acceptable, F/T PSA has no role as a biopsy indicator and its clinical use is questionable.


Assuntos
Biomarcadores Tumorais/sangue , Antígeno Prostático Específico/sangue , Próstata/patologia , Neoplasias da Próstata/diagnóstico , Biópsia , Diagnóstico Diferencial , Humanos , Masculino , Hiperplasia Prostática/diagnóstico , Sensibilidade e Especificidade
9.
Int J Biol Markers ; 20(2): 134-6, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16011045

RESUMO

The aim of the present preliminary study was to investigate the presence of free DNA (FDNA) in urine as a possible marker for the diagnosis of bladder cancer. Naturally voided morning urine specimens were collected from 57 patients with suspected bladder cancer before cystoscopy. A standard urine test was performed; the specimens were then processed in order to obtain a quantitative evaluation of the presence of free DNA in the urine. Twenty-two patients were excluded from the study because they had leukocyturia and/or bacteriuria. Free DNA concentrations higher than 250 ng/mL were found in all 16 patients showing bladder cancer at cystoscopy and in seven (36.8%) of the 19 patients with negative cystoscopy. Urinary FDNA seems to have an excellent sensitivity: we observed no false negative cases and 36.8% false positive cases. By contrast, only 6.25% of the bladder cancer patients had positive urine cytology. Our results seem promising, although further studies and larger numbers are needed to define urinary free DNA as a reliable marker of bladder cancer.


Assuntos
Biomarcadores Tumorais/urina , DNA/urina , Neoplasias da Bexiga Urinária/urina , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade
11.
Eur J Cancer ; 39(7): 1019-29, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12706373

RESUMO

The identification of markers predicting the response to therapy is of the utmost importance in oncology. Several authors have suggested that increased levels of glutathione (GSH) and glutathione S-transferase (GST) activity might be meaningful predictors of poor responsiveness to chemotherapy in several human cancers, but the biological assays have not been standardised and published studies show conflicting evidence. The aim of the present study was to select a validated panel of tests to assess the GST/GSH system in a clinical setting. Matched blood and tissue samples (normal and malignant) from 52 cancer patients with either non-small cell lung cancer (NSCLC) or head and neck squamous cell carcinoma (SCCHN) were investigated. GSH levels and GST activity were higher in cancer tissues than in matched normal tissues in both malignancies. The difference was statistically significant in NSCLC (P=0.0004 and P=0.0002, for GSH and GST, respectively) and borderline in SCCHN (P=0.03 and P=0.02, for GSH and GST, respectively). Moreover a strong correlation was found between the GSH level in whole blood and GST activity in cancer tissue in both malignancies (P=0.003, r=0.53 in NSCLC, P<0.0001, r=0.89 in SCCHN). In conclusion, reliable and robust methods for routine use in tissue extracts and in whole blood have been validated. Our finding regarding the GSH level in blood indicates that circulating GSH could have a clinical relevance as a surrogate marker of GST activity in tumour tissue.


Assuntos
Biomarcadores Tumorais/sangue , Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma de Células Escamosas/sangue , Glutationa Transferase/sangue , Glutationa/sangue , Neoplasias de Cabeça e Pescoço/sangue , Neoplasias Pulmonares/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/enzimologia , Carcinoma de Células Escamosas/enzimologia , Feminino , Neoplasias de Cabeça e Pescoço/enzimologia , Humanos , Neoplasias Pulmonares/enzimologia , Masculino , Pessoa de Meia-Idade
12.
G Ital Med Lav Ergon ; 25 Suppl(3): 219-21, 2003.
Artigo em Italiano | MEDLINE | ID: mdl-14979158

RESUMO

To assess the risk from exposure to stress and burnout in health care workers, a pilot study was planned to compare and integrate the information based on the risk evaluation obtained through different parameters that can be quantified and elaborated to produce a numerical index, called the "Stress Index", and the subjective symptoms from the individual workers. For these purposes, three internationally validated questionnaires were administered: the Job Content Questionnaire, the State-Trait Anxiety Inventory and the Maslach Burnout Inventory. The study considered six different Units from three divisions of Internal Medicine of a large public hospital in Northern Italy, and a total group of 228 health care workers employed in the six units. The results showed an association between the Stress Index scores and the scores from the questionnaires. In particular, in the two units with the highest levels of the index, a significantly higher unbalance between job demand and decision latitude was observed, together with the highest levels of state and trait anxiety and of depersonalization, indicating higher burnout levels.


Assuntos
Esgotamento Profissional/diagnóstico , Humanos , Medição de Risco/métodos , Inquéritos e Questionários
13.
Int J Tissue React ; 24(2): 65-71, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12182235

RESUMO

Hyaluronic acid protects granulation tissue from oxygen free radical damage and stimulates wound healing, but its molecular weight prevents it from permeating the epidermal barrier A low molecular weight hyaluronic acid preparation is able to permeate the skin, but it is unknown whether or not it retains the scavenging effects of oxygen free radicals in granulation tissue. Our experiments were conducted in rats with excisional or incisional wounds. Wound contraction over 11 days and breaking strength on the fifth day were measured. Oxygen free radical production was induced by intraperitoneal administration of two different xenobiotics: phenazine methosulfate and zymosan. The wounds were treated topically with low molecular weight hyaluronic acid (0.2%) cream or placebo. In the incisional wound group, the effects of superoxide dismutase were also determined. Absolute controls received wounds and placebo but no xenobiotics. Wound healing was significantly slower in the xenobiotic group than in the control groups. These effects were strongly reduced by topical administration of low molecular weight hyaluronic acid (0.2%) cream and in incisional wounds by topically injected superoxide dismutase. Low molecular weight hyaluronic acid is effective as the native compound against oxygen free radicals. Its pharmacological effects through transdermal administration should be tested in appropriate models.


Assuntos
Tecido de Granulação/efeitos dos fármacos , Tecido de Granulação/patologia , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Espécies Reativas de Oxigênio/efeitos adversos , Cicatrização/fisiologia , Tecido de Granulação/metabolismo , Humanos , Ácido Hialurônico/farmacocinética , Metilfenazônio Metossulfato/farmacologia , Peso Molecular , Pele/lesões , Resistência à Tração , Fatores de Tempo , Cicatrização/efeitos dos fármacos , Ferimentos Penetrantes/fisiopatologia , Xenobióticos/farmacologia , Zimosan/farmacologia
14.
Headache ; 42(2): 120-4, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12005286

RESUMO

BACKGROUND AND OBJECTIVE: A role for endothelin-1, a potent vasoconstrictor peptide, in some cerebrovascular diseases has been proposed. To obtain preliminary data about peripheral concentrations of endothelin-1 in acute cluster headache, we measured the plasma endothelin-1 secretory pattern in 10 men with cluster during and independent of a headache attack. METHODS: We collected blood samples for plasma endothelin-1 determinations at 0, 15, 30, 45, 60, 90, and 120 minutes during a cluster attack and closely monitored blood pressures. We repeated the same sampling during an asymptomatic period. RESULTS: The mean values of plasma endothelin-1 (before a cluster headache, 3.3 +/- 0.3 pg/mL) significantly increased (F = 2.578, P < .05) during an attack, reaching their peak at 30 minutes (5.0 +/- 0.5 pg/mL, P < .05). We found no significant variations in mean arterial pressure. CONCLUSION: Endothelin-1 may play a role in the pathophysiology of cluster attacks. The increase in plasma observed during cluster attacks may be linked to alterations in systemic hemodynamics and vascular tone.


Assuntos
Cefaleia Histamínica/sangue , Endotelina-2/sangue , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Concentração Osmolar , Valores de Referência , Fatores de Tempo
15.
Biomed Pharmacother ; 55(8): 458-65, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11686580

RESUMO

Multiple endocrine abnormalities have been reported in stroke patients. In the past few years, it has been claimed that some of these abnormalities may play a role in worsening the neurological deficit and the outcome of stroke. Several mechanisms have been hypothesised, including a direct effect on the development of neuronal cell death, vasospasm, and development of brain edema. In this brief review, we discuss the current knowledge concerning the role of endothelin-1, arginine vasopressin, and cortisol in the pathogenesis of stroke. Finally, we discuss the possibility that leptin, the OB gene product, may be the link of some of these endocrine abnormalities, and that its abnormal secretion during stroke may contribute to the eating disorders and poor nutritional status often seen in these patients.


Assuntos
Isquemia Encefálica/fisiopatologia , Doenças do Sistema Endócrino/complicações , Acidente Vascular Cerebral/fisiopatologia , Arginina Vasopressina/fisiologia , Isquemia Encefálica/complicações , Endotelina-1/fisiologia , Humanos , Hidrocortisona/fisiologia , Hipotálamo/fisiologia , Leptina/fisiologia , Sistema Hipófise-Suprarrenal/fisiologia , Acidente Vascular Cerebral/complicações
16.
Biomed Pharmacother ; 55(5): 272-6, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11428553

RESUMO

Endothelin-1 (ET-1) is a potent and long-acting vasoconstrictor peptide, which may play a role in the pathophysiology of a number of diseases. Controversial data exist on its role in human ischemic stroke. In order to ascertain whether changes in ET-1 plasma levels occur in ischemic stroke, plasma ET-1 levels and mean arterial pressure were determined in 15 patients at their first ischemic cerebral infarction and in 15 control subjects, over a 24-hour period. In stroke patients, mean 24-hour plasma ET-1 levels (4.9+/-0.5 ng/L) were higher (P< 0.05) than in control subjects (3.2+/-0.3 ng/L), and correlated with the mean size of the lesion, but not with the severity score of the neurological deficit. These results support the hypothesis that ET-1 levels reflect an indicator function for the amount of damaged cerebral tissue rather than a pathophysiological role.


Assuntos
Endotelina-1/metabolismo , Acidente Vascular Cerebral/metabolismo , Idoso , Pressão Sanguínea/fisiologia , Ritmo Circadiano/efeitos dos fármacos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radioimunoensaio , Acidente Vascular Cerebral/fisiopatologia
18.
Cerebrovasc Dis ; 11(2): 113-8, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11223663

RESUMO

Arginine vasopressin (AVP) may play a role in the development of ischemic brain edema and/or cerebral vasospasm. Data available on AVP plasma levels in ischemic stroke are few and discordant. In order to ascertain whether changes in AVP plasma levels occur in ischemic stroke, plasma AVP levels, plasma osmolality and mean arterial pressure were determined in 24 patients with unprecedented ischemic cerebral infarction and in 15 controls over a 24-hour period. In stroke patients, mean 24-hour plasma AVP levels (7.2 +/- 0.8 ng/l) were higher (p < 0.05) than in control subjects (2.4 +/- 0.3 ng/l), and correlated with the severity score of the neurologic deficit and the mean size of the lesion. In patients with a more severe neurologic deficit, the mean 24-hour plasma AVP levels (8.7 +/- 1.0 ng/l) were higher than in patients with a less severe neurologic deficit (5.2 +/- 0.8 ng/l). Data indicate that in ischemic stroke an increased AVP secretion occurs independently of osmotic or baroreceptorial mechanisms. The possibility that AVP may play a role in neuronal cell damage following cerebral ischemia warrants further attention.


Assuntos
Arginina Vasopressina/sangue , Infarto Encefálico/sangue , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
19.
J Exp Med ; 192(3): 337-46, 2000 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-10934222

RESUMO

2B4 is a surface molecule involved in activation of the natural killer (NK) cell-mediated cytotoxicity. It binds a protein termed Src homology 2 domain-containing protein (SH2D1A) or signaling lymphocyte activation molecule (SLAM)-associated protein (SAP), which in turn has been proposed to function as a regulator of the 2B4-associated signal transduction pathway. In this study, we analyzed patients with X-linked lymphoproliferative disease (XLP), a severe inherited immunodeficiency characterized by critical mutations in the SH2D1A gene and by the inability to control Epstein-Barr virus (EBV) infections. We show that, in these patients, 2B4 not only fails to transduce triggering signals, but also mediates a sharp inhibition of the NK-mediated cytolysis. Other receptors involved in NK cell triggering, including CD16, NKp46, NKp44, and NKp30, displayed a normal functional capability. However, their activating function was inhibited upon engagement of 2B4 molecules. CD48, the natural ligand of 2B4, is highly expressed on the surface of EBV(+) B cell lines. Remarkably, NK cells from XLP patients could not kill EBV(+) B cell lines. This failure was found to be the consequence of inhibitory signals generated by the interaction between 2B4 and CD48, as the antibody-mediated disruption of the 2B4-CD48 interaction restored lysis of EBV(+) target cells lacking human histocompatibility leukocyte antigen (HLA) class I molecules. In the case of autologous or allogeneic (HLA class I(+)) EBV(+) lymphoblastoid cell lines, restoration of lysis was achieved only by the simultaneous disruption of 2B4-CD48 and NK receptor-HLA class I interactions. Molecular analysis revealed that 2B4 molecules isolated from either XLP or normal NK cells were identical. As expected, in XLP-NK cells, 2B4 did not associate with SH2D1A, whereas similar to 2B4 molecules isolated from normal NK cells, it did associate with Src homology 2 domain-containing phosphatase 1.


Assuntos
Antígenos CD , Herpesvirus Humano 4/imunologia , Peptídeos e Proteínas de Sinalização Intracelular , Células Matadoras Naturais/imunologia , Transtornos Linfoproliferativos/imunologia , Glicoproteínas de Membrana/imunologia , Receptores Imunológicos/imunologia , Transdução de Sinais , Cromossomo X , Sequência de Bases , Proteínas de Transporte/genética , Linhagem Celular , Membrana Celular/metabolismo , Pré-Escolar , DNA Complementar , Ligação Genética , Humanos , Células Matadoras Naturais/virologia , Ativação Linfocitária/imunologia , Transtornos Linfoproliferativos/sangue , Transtornos Linfoproliferativos/genética , Masculino , Glicoproteínas de Membrana/biossíntese , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/fisiologia , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mutação , Receptor 1 Desencadeador da Citotoxicidade Natural , Receptores Imunológicos/metabolismo , Proteína Associada à Molécula de Sinalização da Ativação Linfocitária , Família de Moléculas de Sinalização da Ativação Linfocitária , Células Tumorais Cultivadas
20.
J Hepatol ; 33(1): 33-7, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10905583

RESUMO

BACKGROUND/AIM: Serum levels of leptin, the adipocyte-derived hormone regulating food intake and energy expenditure in mammals, have been found to be increased in cirrhotic patients. The aim of the present study was to investigate leptin serum level in relation to anthropometric features and liver function in patients with viral chronic hepatitis or liver cirrhosis. METHODS: Serum leptin levels were determined by radioimmunoassay in 30 male and 10 female patients with chronic hepatitis, in 42 male and 10 female patients with liver cirrhosis, and in four respective control groups. Liver function was evaluated by the monoethylglycinexylidide formation test. Body mass index and body fat mass were estimated by weight, height and skinfold thickness measurements. RESULTS: Compared with controls, absolute serum leptin levels were significantly (p<0.01) lower in chronic hepatitis patients and similar in cirrhotic patients. Leptin serum levels were significantly (p<0.05) higher in cirrhotic than in chronic hepatitis patients. When expressed in relation to body fat mass, the above differences persisted; however, cirrhotic females showed significantly (p<0.05) higher serum leptin values than controls. Serum leptin values correlated negatively (p<0.01) with monoethylglycinexylidide serum values in all groups of patients. CONCLUSIONS: In patients with chronic viral liver disease, serum leptin levels tend to increase as liver function worsens. This may reflect a decline in the ability to downregulate energy expenditure as an adaptation to anorexia and/or to defective substrate utilisation due to liver disease and may negatively influence body weight homeostasis in these patients.


Assuntos
Hepatite B Crônica/sangue , Hepatite C Crônica/sangue , Leptina/sangue , Lidocaína/análogos & derivados , Cirrose Hepática/sangue , Tecido Adiposo/patologia , Adulto , Feminino , Hepatite B Crônica/complicações , Hepatite B Crônica/patologia , Hepatite C Crônica/complicações , Hepatite C Crônica/patologia , Humanos , Lidocaína/sangue , Cirrose Hepática/patologia , Cirrose Hepática/virologia , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Valores de Referência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...