RESUMO
After transplant, patient infection with human herpesvirus 8 (HHV-8) and Kaposi sarcoma-associated herpesvirus (KSHV) is known to cause aggressive tumors and severe nonneoplastic complications. These latter syndromes are driven by HHV-8/KSHV lytic reactivations and related hyperinflammatory host responses typically characterized by high viral loads, elevated levels of cytokines and other inflammation biomarkers, cytopenia, organ failure, high fever, and worsening conditions (with no evidence of B cell neoplasias). These disorders are associated with a high mortality rate, often due to lack of prompt diagnosis, effective therapeutic approaches, and adequate follow-up. These features resemble most of those defining the so-called KSHV-associated inflammatory cytokine syndrome (KICS), which was recently recognized in patients positive for human immunodeficiency virus (HIV). In this report, we describe-for the first time-a case of a KICS-like nonneoplastic recurrent complication occurring after transplant in an HIV-negative patient that was successfully treated by a combination of anti-CD20 monoclonal therapy, antivirals, and modification of the immunosuppressive regimen. In addition to clinical and laboratory findings collected during 3-year follow-up, we report novel experimental data on HHV-8-specific T cell dynamics and circulating microRNA profile, showing correlations with clinical course and other laboratory markers (including viral load, C-reactive protein, and cytokine levels), providing useful information about abnormal cellular and cytokine dynamics underlying HHV-8-associated inflammatory disorders in posttransplant patients.
Assuntos
Citocinas/metabolismo , Rejeição de Enxerto/tratamento farmacológico , Imunossupressores/uso terapêutico , Inflamação/tratamento farmacológico , Transplante de Rim/efeitos adversos , Transplante de Fígado/efeitos adversos , Sarcoma de Kaposi/tratamento farmacológico , Adulto , Feminino , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto , Herpesvirus Humano 8/patogenicidade , Humanos , Inflamação/etiologia , Inflamação/patologia , Complicações Pós-Operatórias , Prognóstico , Fatores de Risco , Sarcoma de Kaposi/etiologia , Sarcoma de Kaposi/patologia , Síndrome , Doadores de Tecidos , Carga ViralRESUMO
Healthcare workers who use or may be exposed to needles are at risk of needlestick injuries, which can lead to serious infections by bloodborne pathogens. These injuries can be avoided by eliminating the unnecessary use of needles and using safety devices. The present study was aimed at evaluating the impact of a safety-engineered device, with passive fully automatic needlestick protection, on the rate of needlestick injuries among healthcare workers. The setting of the study was a network of five public healthcare institutions situated in a Northern Italian Region. Data on the type of device, the number of employees and the number of catheter devices used per year were collected through regular meetings with healthcare workers over a period of five years. The most notable result of this study was the huge risk reduction associated with safety devices. Indeed, the risk of needlestick injuries due to conventional devices was found to be 25-fold higher than that observed for safety devices. However, it is noteworthy that a considerable part of this excess can be explained by the different background number of devices used. Moreover, descriptive analysis suggested that individuals with a poor/moderate training level had a lower risk than those with good/high training, though the difference was not statistically significant. In conclusion, there is convincing evidence of a causal connection between the introduction of safety devices and the reduction in needlestick injuries. This consideration should prompt the introduction of safety devices into daily clinical practice.
Assuntos
Pessoal de Saúde , Ferimentos Penetrantes Produzidos por Agulha/prevenção & controle , Equipamentos de Proteção , Humanos , ItáliaRESUMO
OBJECTIVES: Little is known regarding outcomes and optimal therapeutic regimens of infections caused by Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) resistant to ceftazidime/avibactam (CZA) and susceptible to meropenem (MEM). Although susceptible to MEM in vitro, the possibility of developing MEM resistance overtime is a concern. We describe the clinical characteristics of patients with colonization/infection due to KPC variants with a focus on the in vitro activity of fosfomycin (FOS)-containing combinations. METHODS: Patients with colonization/infection due to a KPC variant were included. Fosfomycin susceptibility was performed by agar dilution method. Synergistic activity of FOS-based combinations was evaluated by gradient strip-agar diffusion method. The emergence of in vitro MEM resistance was also tested. RESULTS: Eleven patients were included: eight with infection [four with ventilator-associated pneumonia and four with bloodstream infections] and three with colonization. Previous therapy with CZA was administered to all patients (with a mean cumulative duration of 23 days). All subjects with infection received meropenem, in monotherapy (n = 4) or with amikacin (n = 2) or fosfomycin (n = 2), and achieved clinical cure. A new CZA-susceptible and MEM-resistant KPC-Kp strain was subsequently isolated in three patients (27.3%). Meropenem/vaborbactam (MVB) showed high in vitro activity, while FOS+MEM combination was synergistic in 40% of cases. In vitro resistance to MEM was observed with maintenance of CZA resistance. CONCLUSIONS: Detection of KPC variants may occur within the same patient, especially if CZA has been previously administered. Although clinical success has been obtained with carbapenems, the emergence of MEM resistance is a concern. Fosfomycin plus meropenem is synergistic and may be a valuable combination option for KPC variants, while MVB may be considered in monotherapy. The detection of KPC variants in an endemic setting for KPC-Kp represents a worryingly emerging condition. The optimal therapeutic approach is still unknown and the development of meropenem resistance is of concern, which may lead to therapeutic failure in clinical practice. In these cases, the addition of fosfomycin to meropenem, or a more potent antibiotic, such as meropenem/vaborbactam, may be valuable therapeutic options.
Assuntos
Fosfomicina , Infecções por Klebsiella , Humanos , Ceftazidima/uso terapêutico , Meropeném/farmacologia , Meropeném/uso terapêutico , Fosfomicina/farmacologia , Fosfomicina/uso terapêutico , Klebsiella pneumoniae , Ágar/uso terapêutico , Infecções por Klebsiella/tratamento farmacológicoRESUMO
The attributes of egg production that elicit values-based responses include the price and availability of eggs, environmental impacts, food safety or health concerns, and animal welfare. Different social groups have distinct interests regarding the sustainability of egg production that reflect these diverse values. Current scientifically based knowledge about how values and attitudes in these groups can be characterized is uneven and must be derived from studies conducted at varying times and using incomplete study methods. In general, some producer and consumer interests are translated through markets and are mediated by market mechanisms, whereas others are poorly reflected by economic behavior. An array of survey and focus group research has been performed to elicit consumer and activist beliefs about performance goals they would expect from an egg production system. These studies provide evidence that consumers' market behavior may be at odds with their ethical and political beliefs about performance goals.
Assuntos
Criação de Animais Domésticos/métodos , Galinhas , Conservação dos Recursos Naturais/métodos , Comportamento do Consumidor , Ovos/normas , Bem-Estar do Animal/normas , Animais , Feminino , Responsabilidade SocialRESUMO
Official inspections to check the compliance of farms with European legislation to protect farm animals are often perceived negatively by farmers. In addition, the inspections have a limited effect on improving farm compliance. We looked at the perceptions of both farmers and their inspectors about animal welfare and the inspections in a case study of dairy production in France. The identification of gaps and commonalities between both parties should help us to propose improvements in the inspection method by which inspections could more likely encourage compliance with animal welfare legislation. To achieve this aim, we conducted semi-structured interviews with 22 dairy farmers and their 19 inspectors. Both farmers and inspectors described animal welfare in terms of the state of the animal and of the living conditions and care provided to them. The majority of farmers found that the official checklist used by the inspectors is inappropriate to assess the welfare of their animals; inspectors themselves reported that they often use their own criteria and indicators (often based on the observation of animals) in addition to the official checklist. Both groups disagreed with some requirements of the legislation. These findings suggest that the content and background of the legislation to protect animals should be made clearer to both farmers and inspectors and that these two groups of actors should be involved in the definition of key points to be checked on farms, with special attention to animal-based indicators. All this could improve farmers' engagement with the results of the inspections and, hopefully, could lead to better compliance with legislation and improvements in animal welfare on farms.
Assuntos
Bem-Estar do Animal , Fazendeiros , Animais , Animais Domésticos , Indústria de Laticínios , Fazendas , França , HumanosRESUMO
BACKGROUND: Microcell-mediated transfer of chromosome 6 into human C8161 and MelJuSo melanoma cell suppresses their ability to metastasize by at least 95% without affecting their tumorigenicity. This observation demonstrates that the ability to metastasize is a phenotype distinct from tumor formation and suggests that tumorigenic cells acquire metastatic capability only after accumulating additional genetic defects. These results also imply that mutations of genes on chromosome 6 are among those late genetic changes responsible for metastatic potential. They further suggest that a melanoma metastasis-suppressor gene(s) is encoded on chromosome 6 or is regulated by genes on chromosome 6. PURPOSE: Our objective was to identify the gene(s) responsible for the suppression of metastasis in chromosome 6/melanoma cell hybrids. METHODS: A modified subtractive hybridization technique was used to compare the expression of messenger RNAs (mRNAs), via an analysis of complementary DNAs (cDNAs), in metastatic cells (C8161 or MelJuSo) and nonmetastatic hybrid clones (neo6/C8161 or neo6/MelJuSo). RESULTS: A novel cDNA, designated KiSS-1, was isolated from malignant melanoma cells that had been suppressed for metastatic potential by the introduction of human chromosome 6. Northern blot analyses comparing mRNAs from a panel of human melanoma cells revealed that KiSS-1 mRNA expression occurred only in nonmetastatic melanoma cells. Expression of this mRNA in normal heart, brain, liver, lung, and skeletal muscle was undetectable by northern blot analysis. Weak expression was found in the kidney and pancreas, but the highest expression was observed in the placenta. The KiSS-1 cDNA encodes a predominantly hydrophilic, 164 amino acid protein with a polyproline-rich domain indicative of an SH3 ligand (binds to the homology 3 domain of the oncoprotein Src) and a putative protein kinase C-alpha phosphorylation site. Transfection of a full-length KiSS-1 cDNA into C8161 melanoma cells suppressed metastasis in an expression-dependent manner. CONCLUSIONS: These data strongly suggest that KiSS-1 expression may suppress the metastatic potential of malignant melanoma cells. IMPLICATIONS: KiSS-1 may be a useful marker for distinguishing metastatic melanomas from nonmetastatic melanomas.
Assuntos
Genes Supressores de Tumor , Melanoma/genética , Metástase Neoplásica/genética , Sequência de Aminoácidos , Análise de Variância , Animais , Northern Blotting , Humanos , Melanoma/secundário , Camundongos , Camundongos Nus , Dados de Sequência Molecular , Transfecção , Células Tumorais CultivadasRESUMO
To determine the relevance of genetic information on chromosome 11 in the development of metastatic breast tumors, we introduced a normal human chromosome 11 into the highly metastatic MDA-MB-435 breast carcinoma cell line via the microcell-mediated chromosome transfer technique. Although the MDA-MB-435 recipient cell line and four randomly selected microcell hybrid clones remained tumorigenic in nude mice, the hybrids were >95% suppressed for metastasis to lung and regional lymph nodes (p<0.01). We also tested whether chromosome 6 harbors a metastasis-suppressor gene for breast cancer as observed previously for human melanoma. Grouped together, the four neo6 microcell hybrids had no statistically significant reduction in the incidence or number of lung or lymph node metastases compared to the weakly metastatic, subcloned parent cell line, MDA-MB-453.7. Expression of nm23-H1 (NME1), a known metastasis-suppressor gene in this breast cancer cell line, did not correlate with metastasis suppression in the microcell hybrids. These results further demonstrate that control of metastasis is molecularly distinct from tumorigenic potential. They also indicate that chromosome 11 encodes a metastasis-suppressor gene for human breast cancer.
Assuntos
Neoplasias da Mama/genética , Carcinoma Ductal de Mama/genética , Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 6/genética , Técnicas de Transferência de Genes , Genes Supressores de Tumor , Adulto , Animais , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Carcinoma Ductal de Mama/secundário , Fusão Celular/genética , Feminino , Humanos , Células Híbridas , Cariotipagem , Camundongos , Camundongos Nus , Metástase Neoplásica/genética , Transplante de Neoplasias , Células Tumorais CultivadasRESUMO
Structural alterations of chromosome 6, including del(6q), are often associated with metastatic melanoma; therefore, we hypothesized that a metastasis-suppressor gene could be coded on human chromosome 6. Highly metastatic C8161 human malignant melanoma cells exhibit chromosomal changes typical of late-stage melanomas. Using microcell-mediated chromosome transfer, a copy of a normal human chromosome 6 was introduced into C8161. Three randomly selected hybrid clones (neo6/C8161.1, neo6/C8161.2 and neo6/C8161.3) were assayed for metastasis in athymic nude mice. All controls - parental C8161 cells, randomly-selected single cell clones, neo-transfected cell clones, neo11/C8161.2 and neo11/C8161.3 - were tumorigenic (270/272 mice) and metastatic (208/272 mice). neo6/C8161 hybrid cells were still tumorigenic (91/93 mice) but were not metastatic (0/195 mice). The presence of the added chromosomes was verified in cultured and tumor cells by amplification of polymorphic (CA)n markers using PCR-RFLP. The neo6/C8161 hybrids display growth and morphological patterns of more differentiated cells than C8161. In Northern blot analysis an inverse relationship between metastatic ability and metastasis-suppressor gene, nm23-H1, expression is observed - with clone neo6/C8161.1 expressing the highest level of nm23 transcripts, neo6/C8161.2 and neo6/C8161.3 expressing intermediate levels, and barely detectable levels are seen in C8161. Collectively, these results suggest that a malignant melanoma metastasis-regulatory gene may be located on human chromosome 6. These results further demonstrate that tumorigenicity and metastatic ability are distinct phenotypes.
Assuntos
Cromossomos Humanos Par 6 , Genes Supressores de Tumor , Melanoma/genética , Metástase Neoplásica/prevenção & controle , Animais , Cromossomos Humanos Par 11 , Feminino , Humanos , Camundongos , Metástase Neoplásica/genética , Células Tumorais CultivadasAssuntos
Antígenos CD34/análise , Preservação de Sangue , Criopreservação , Transplante de Células-Tronco Hematopoéticas/métodos , Separação Imunomagnética , Linfoma Anaplásico de Células Grandes/sangue , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carmustina/administração & dosagem , Contagem de Células , Pré-Escolar , Terapia Combinada , Ciclofosfamida , Citarabina/administração & dosagem , Fator Estimulador de Colônias de Granulócitos , Mobilização de Células-Tronco Hematopoéticas , Humanos , Separação Imunomagnética/instrumentação , Leucaférese , Linfoma Anaplásico de Células Grandes/tratamento farmacológico , Linfoma Anaplásico de Células Grandes/cirurgia , Melfalan/administração & dosagem , Podofilotoxina/administração & dosagem , Recidiva , Transplante AutólogoRESUMO
Metastasis is suppressed more than 95% following microcell-mediated transfer of a single copy of neomycin-tagged human chromosome 6 (neo6) into the human melanoma cell lines C8161 and MelJuSo. Concomitant with metastasis suppression is upregulation of NME1 (Nm23-H1) mRNA and protein expression. The purposes of this study were to determine whether NME1 expression was responsible for metastasis suppression in neo6/melanoma hybrids, and whether genes on chromosome 6 regulate NME1. Using neo6/C8161 cells, transfection of CAT reporter constructs linked to the NME1 promoter failed to consistently induce CAT. Therefore, it does not appear that genes on chromosome 6 directly control transcription of NME1. Transfection and overexpression of NME1 in MelJuSo, under the control of the CMV promoter, resulted in 40-80% inhibition of lung metastasis following i.v. inoculation of 2 x 10(5) cells. Only one transfectant of C8161 subclone 9 (C8161cl.9) cells was suppressed for metastasis. Control transfections with pCMVneo or pSV2neo did not suppress metastasis in either cell line. Taken together, these data suggest that NME1 can reduce metastatic potential of some human melanoma cells; but, this inhibitory activity appears to be independent of the metastasis suppression following introduction of chromosome 6 into C8161 and MelJuSo human melanoma cell lines.
Assuntos
Cromossomos Humanos Par 6 , Melanoma/prevenção & controle , Melanoma/secundário , Proteínas Monoméricas de Ligação ao GTP , Núcleosídeo-Difosfato Quinase , Fatores de Transcrição/fisiologia , Animais , Genes Supressores de Tumor , Humanos , Camundongos , Nucleosídeo NM23 Difosfato Quinases , Transfecção , Células Tumorais CultivadasRESUMO
A deficiency of striatal dopamine (DA) is generally accepted as an expression of manganese (Mn) toxicity in experimental animals. Since compromised cellular defence mechanisms may be involved in Mn neurotoxicity, we investigated the response of the neuronal antioxidant system [ascorbic acid (AA) oxidation, glutathione (GSH) and uric acid levels] and neurochemical changes in the striatum in aged rats exposed to Mn. Levels of dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), AA, dehydroascorbic acid (DHAA), GSH and uric acid were determined after subchronic oral exposure to MnCl2 200 mg/kg (3-month-old rats) and 30-100-200 mg/kg (20-month-old-rats). Aged rats had basal levels of striatal DA, DOPAC, HVA, 5-HT, 5-HIAA, GSH and AA lower than those of young rats. In the striatum of aged rats, Mn induced biphasic changes in the levels of DA, DOPAC, HVA (an increase at the lower dose and a decrease at the higher dose) and DHAA (opposite changes). Mn decreased GSH levels and increased uric acid levels both in the striatum and in synaptosomes in all groups of aged rats. All of these parameters were affected to a lesser extent in young rats. In conclusion, the response of cellular defence mechanisms in aged rats is consistent with a Mn-induced increase in the formation of reactive oxygen species. An age-related impairment of the neuronal antioxidant system may play an enabling role in Mn neurotoxicity.
Assuntos
Envelhecimento/fisiologia , Intoxicação por Manganês , Neostriado/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Animais , Ácido Ascórbico/metabolismo , Dopamina/metabolismo , Glutationa/metabolismo , Masculino , Neostriado/citologia , Neostriado/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Serotonina/metabolismo , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismo , Ácido Úrico/metabolismoRESUMO
Extracellular brain ascorbate fluctuates with neuronal activity. There is previous evidence that the release of ascorbate is triggered by the re-uptake of neuronally released glutamate. This hypothesis predicts that drugs which block the release and re-uptake of glutamate will also block the release of ascorbate. In the present experiments we have used a novel dialysis electrode which allows continuous monitoring of physiologically induced ascorbate release from the striatum in freely moving rats. An infusion of the enzyme ascorbic acid oxidase abolished the increase in oxidation current in response to tail-pinch, which identified it as an ascorbate current. Perfusion with tetrodotoxin reduced the response to 25% and with CdCl2 to 4% of control. Perfusion with the uptake blocker L-trans-pyrrolidine-2,4-di-carboxylate reduced the response to 24% of control. A neuroprotective function for this coupling of ascorbate and glutamate release is discussed.
Assuntos
Ácido Ascórbico/metabolismo , Encéfalo/metabolismo , Encéfalo/fisiologia , Cálcio/metabolismo , Glutamatos/metabolismo , Animais , Ascorbato Oxidase/farmacologia , Cádmio/farmacologia , Ácidos Dicarboxílicos/farmacologia , Antagonistas de Aminoácidos Excitatórios , Masculino , Estimulação Física , Pirrolidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Tetrodotoxina/farmacologiaRESUMO
1. We showed previously that interaction between NO and iron(II), both released following decomposition of sodium nitroprusside (SNP), accounted for the late SNP-induced dopamine (DA) increase in dialysates from the striatum of freely moving rats. 2. In this study, intrastriatal infusion of the NO-donor S-nitroso-N-acetylpenicillamine (SNAP) (0.2 mM for 180 min) induced a moderate increase in dialysate DA and decreases in ascorbic acid dialysate concentrations; in contrast, SNAP 1 mM infusion induced a long-lasting decrease in both DA and ascorbic acid dialysate concentrations. 3-Methoxy-tyramine (3-MT), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and uric acid levels were unaffected. 3. Co-infusion of ferrous sulphate [iron(II), 1 mM for 40 min] with SNAP either 1 or 0.2 mM (for 180 min), produced a significant increase in both DA and 3-MT dialysate concentrations, but it did not affect decreases in dialysate ascorbic acid levels. All other dialysate neurochemicals were unaffected. 4. Co-infusion of ascorbic acid (0.1 mM) with SNAP (1 mM) for 180 min did not modify SNAP-induced decreases in dialysate DA levels. In contrast, co-infusion of uric acid (1 mM) reversed SNAP-induced decreases in dialysate DA; co-infusion of a superoxide dismutase mimetic delayed SNAP-induced DA decreases for a short period, while co-infusion of the antioxidant N-acetylcysteine (NAC, 0.1 mM) significantly increased dialysate DA. 5. The results of this study show that SNAP induces concentration-related changes in DA dialysate levels. At higher concentrations, SNAP induces non-enzymatic DA oxidation, which is inhibited by uric acid and NAC; ascorbic acid failed to protect dialysate DA from oxidation, probably owing to its promoting effect on SNAP decomposition; exogenous iron(II) may react with NO generated from SNAP decomposition, with a consequent increase in dialysate DA and 3-MT, therefore mimicking SNP effects on striatal DA release.
Assuntos
Ácido Ascórbico/fisiologia , Corpo Estriado/efeitos dos fármacos , Dopamina/metabolismo , Doadores de Óxido Nítrico/farmacologia , Estresse Oxidativo , Penicilamina/farmacologia , Acetilcisteína/farmacologia , Animais , Corpo Estriado/metabolismo , Ferro/metabolismo , Masculino , Microdiálise , Penicilamina/análogos & derivados , Ratos , Ratos Wistar , S-Nitroso-N-AcetilpenicilaminaRESUMO
1. We showed previously that interaction between NO and iron (II), both released following the decomposition of sodium nitroprusside (SNP), accounted for the late SNP-induced dopamine (DA) increase in dialysates from the striatum of freely moving rats; in addition, we showed that co-infusion of iron (II) with the NO-donor S-nitroso-N-acetylpenicillamine mimicked SNP effects on striatal DA release. 2. In the present study, intrastriatal co-infusion of iron (II) (given as FeSO(4), 1 mM for 40 min) with the NO-donor and potential peroxynitrite generator 3-morpholinosydnonimine (SIN-1) (0.2, 0.5, 1.0 or 5.0 mM for 180 min), potentiated the SIN-1-induced increase in DA concentration in dialysates from the striatum of freely moving rats. Neither alone nor associated with iron (II) did SIN-1 induce changes in dialysate ascorbic acid or uric acid concentrations. 3. Neither co-infusion of a superoxide dismutase mimetic nor uric acid affected SIN-1-induced increases in dialysate DA concentration. 4. Infusion of the iron chelator deferoxamine (0.2 mM for 180 min) decreased dialysate DA and attenuated SIN-1-induced increases in dialysate DA concentrations. 5. These results suggest that iron plays a key role in SIN-1-induced release of striatal DA and do not support any role for either peroxynitrite or superoxide anion in SIN-1-induced release of striatal DA.
Assuntos
Corpo Estriado/efeitos dos fármacos , Dopamina/metabolismo , Ferro/farmacologia , Molsidomina/análogos & derivados , Molsidomina/farmacologia , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico/fisiologia , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Acetilcisteína/farmacologia , Animais , Ácido Ascórbico/metabolismo , Corpo Estriado/metabolismo , Desferroxamina/farmacologia , Soluções para Diálise/química , Relação Dose-Resposta a Droga , Sequestradores de Radicais Livres/farmacologia , Ácido Homovanílico/metabolismo , Masculino , Metaloporfirinas/farmacologia , Movimento , Ratos , Ratos Wistar , Ácido Úrico/metabolismo , Ácido Úrico/farmacologiaRESUMO
The effects of intrastriatal infusion of 3-morpholinosydnonimine (SIN-1) or sodium nitroprusside (SNP) on dopamine (DA), 3-methoxytyramine (3-MT), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), L-dihydroxyphenylalanine (L-DOPA), ascorbic acid and uric acid concentrations in dialysates from the striatum of freely moving rats were evaluated using microdialysis. SIN-1 (1 mM) infusion for 180 min increased microdialysate DA and 3-MT concentrations, while L-DOPA, DOPCA+HVA, ascorbic acid and uric acid levels were unaffected. Co-infusion with ascorbic acid (0.1 mM) inhibited SIN-1-induced increases in DA and 3-MT dialysate concentration. SNP (1 mM) infusion for 180 min increased greatly the dialysate DA concentration to a peak (2950% of baseline) at the end of the infusion, while increases in 3-MT were negligible. In addition, SNP decreased ascorbic acid and L-DOPA but increased uric acid concentration in the dialysate. Co-infusion with deferoxamine (0.2 mM) inhibited the late SNP-induced increase in DA dialysate concentration, but did not affect the decrease in ascorbic acid and increase uric acid dialysate concentrations. SNP (1 mM) infusion for 20 min moderately increased uric acid, DA and 3-MT, but decreased L-DOPA levels in the dialysate. Ascorbic acid concentration increased at the end of SNP infusion. Co-infusion with ascorbic acid (0.1 mM) inhibited the SNP-induced increase in DA and 3-MT, but did not affect the decrease in L-DOPA and increase in uric acid dialysate concentrations. These results suggest that NO released from SIN-1 may account for the increase in the dialysate DA concentration. NO released following decomposition of SNP may account for the early increase in dialysate DA, while late changes in microdialysate composition following SNP may result from an interaction between NO and the ferrocyanide moiety of SNP. Exogenous ascorbic acid inhibits the effect of exogenous NO on DA release probably by scavenging NO, suggesting that endogenous ascorbic acid may modulate the NO control of DA release from 300 striatal dopaminergic terminals.
Assuntos
Ácido Ascórbico/farmacologia , Corpo Estriado/metabolismo , Dopamina/metabolismo , Ferro/fisiologia , Molsidomina/análogos & derivados , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico/fisiologia , Nitroprussiato/farmacologia , Animais , Desferroxamina/farmacologia , Masculino , Microdiálise , Molsidomina/farmacologia , Ratos , Ratos WistarRESUMO
1. The effects of systemic, intrastriatal or intranigral administration of d-amphetamine on glutamate, aspartate, ascorbic acid (AA), uric acid, dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) concentrations in dialysates from the striatum of freely-moving rats were evaluated using microdialysis. 2. d-Amphetamine (2 mg kg-1) given subcutaneously (s.c.) increased DA, AA and uric acid and decreased DOPAC + HVA, glutamate and aspartate dialysate concentrations over a 3 h period after d-amphetamine. 5-HIAA concentrations were unaffected. Individual changes in glutamate and AA dialysate concentrations were negatively correlated. 3. d-Amphetamine (0.2 mM), given intrastriatally, increased DA and decreased DOPAC + HVA and aspartate dialysate concentrations, but failed to change those of glutamate, AA uric acid or 5-HIAA, over a 2 h period after d-amphetamine. Haloperidol (0.1 mM), given intrastriatally, increased aspartate concentrations without affecting those of glutamate or AA. 4. d-Amphetamine (0.2 mM), given intranigrally, increased AA and uric acid dialysate concentrations and decreased those of glutamate, aspartate and DA; DOPAC + HVA and 5-HIAA concentrations were unaffected. 5. These results suggest that d-amphetamine-induced increases in AA and uric acid and decreases in glutamate concentrations are triggered at nigral sites. The changes in aspartate levels may be evoked by at least two mechanisms: striatal (mediated by inhibitory dopaminergic receptors) and nigral (activation of amino acid carrier-mediated uptake).
Assuntos
Ácido Ascórbico/metabolismo , Dextroanfetamina/farmacologia , Inibidores da Captação de Dopamina/farmacologia , Ácido Glutâmico/metabolismo , Neostriado/metabolismo , Ácido Úrico/metabolismo , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Animais , Dextroanfetamina/administração & dosagem , Dopamina/metabolismo , Antagonistas de Dopamina/farmacologia , Inibidores da Captação de Dopamina/administração & dosagem , Haloperidol/farmacologia , Técnicas In Vitro , Injeções , Masculino , Microdiálise , Atividade Motora/efeitos dos fármacos , Neostriado/efeitos dos fármacos , Oxirredução , Ratos , Ratos Wistar , Técnicas Estereotáxicas , Comportamento Estereotipado/efeitos dos fármacosRESUMO
We have previously shown that manganese enhances L-dihydroxyphenylanine (L-DOPA) toxicity to PC12 cells in vitro. The supposed mechanism of manganese enhancing effect [an increase in L-DOPA and dopamine (DA) auto-oxidation] was studied using microdialysis in the striatum of freely moving rats. Systemic L-DOPA [25 mg kg(-1) intraperitoneally (i.p.) twice in a 12 h interval] significantly increased baseline dialysate concentrations of L-DOPA, dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and uric acid, compared to controls. Conversely, DA and ascorbic acid concentrations were significantly decreased. A L-DOPA oxidation product, presumptively identified as L-DOPA semiquinone, was detected in the dialysate. The L-DOPA semiquinone was detected also following intrastriatal infusion of L-DOPA. In rats given L-DOPA i.p. , intrastriatal infusion of N-acetylcysteine (NAC) significantly increased DA and L-DOPA dialysate concentrations and lowered those of L-DOPA semiquinone; in addition, NAC decreased DOPAC+HVA and uric acid dialysate concentrations. In rats given L-DOPA either systemically or intrastriatally, intrastriatal infusion of manganese decreased L-DOPA dialysate concentrations and greatly increased those of L-DOPA semiquinone. These changes were inhibited by NAC infusion. These findings demonstrate that auto-oxidation of exogenous L-DOPA occurs in vivo in the rat striatum. The consequent reactive oxygen species generation may account for the decrease in dialysate DA and ascorbic acid concentrations and increase in enzymatic oxidation of xanthine and DA. L-DOPA auto-oxidation is inhibited by NAC and enhanced by manganese. These results may be of relevance to the L-DOPA long-term therapy of Parkinson's disease.
Assuntos
Corpo Estriado/efeitos dos fármacos , Levodopa/metabolismo , Manganês/farmacologia , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Acetilcisteína/farmacologia , Animais , Ácido Ascórbico/metabolismo , Cloretos/farmacologia , Cromatografia Líquida de Alta Pressão , Corpo Estriado/metabolismo , Soluções para Diálise/química , Dopamina/metabolismo , Ácido Homovanílico/metabolismo , Bombas de Infusão , Levodopa/farmacologia , Levodopa/uso terapêutico , Masculino , Compostos de Manganês/farmacologia , Microdiálise , Movimento , Oxirredução/efeitos dos fármacos , Doença de Parkinson/tratamento farmacológico , Ratos , Ratos Wistar , Fatores de Tempo , Ácido Úrico/metabolismoRESUMO
Soluble and nuclear estrogen receptor (ER) content was measured by ligand binding assay, and estrogen and progesterone receptors by immunohistochemical assays (ER-ICA and PR-ICA) in 214 patients with breast cancer recruited at the "M. Ascoli" Cancer Hospital Centre in Palermo, Sicily, to assess the discriminant and predictive value of these parameters. On follow-up, data from both ER-ICA and PR-ICA showed a statistically significant difference, PR-positive patients having longer disease-free (DSF) and overall (OS) survival than PR-negative ones. Conversely, ER status did not correlate significantly with both DFS (P = 0.6) and OS (P = 0.2). In particular, PR-positive patients had 59 +/- 18 months DFS and 67 +/- 12 months OS, compared to 51 +/- 22 months DFS and 57 +/- 17 months OS of PR-negative cases. The present evidence implies that a PR-negative status identifies breast cancer patients with early relapse, as also suggested by previous studies. It also agrees with the results of ligand binding assay of ER, where ER status is a good discriminant and predictor of response to endocrine treatment, but is unable to anticipate early relapse in breast cancer patients. Evidence that PR status is a statistically significant prognostic indicator deserves further study to ascertain whether or not PR should be regarded as an ER-dependent parameter or be related to other biological variables such as growth factor (e.g., EGF), oncogene (e.g., Her2/Neu), or tumor suppressor gene (e.g., p53) products.
Assuntos
Neoplasias da Mama/metabolismo , Estrogênios/metabolismo , Receptores de Progesterona/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Sítios de Ligação , Feminino , Seguimentos , Humanos , Imuno-Histoquímica , Ligantes , Pessoa de Meia-IdadeRESUMO
Preliminary evidence from a case control study of healthy postmenopausal women living in Palermo, Sicily, is presented to investigate the potential impact of a traditional Mediterranean diet on the risk of developing breast cancer. Of the 230 women who fulfilled specific eligibility criteria, 115 were enrolled in the study based on serum testosterone values equal to or greater than the median population value (0.14 microg/ml). Women were then individually randomized into a diet intervention (n = 58) and a control (n = 55) group. Women in the intervention group attended a weekly "cooking course" for 1 year, being trained by professional chefs in the correct use of the natural ingredients of the traditional Mediterranean diet, including whole cereals, legumes, seeds, fish, cruciferous vegetables, and many others. The intervention group was subsequently instructed to follow the learned diet at home, while the control group was only advised to increase the consumption of fruits and vegetables, as recommended by WHO. The following measures were taken at the beginning, middle, and end of the study: (a) fasting blood and 12-hour urine samples to assay defined hormonal endpoints; (b) height, weight, and circumference of the waist and hip; and (c) a food frequency and computerized 24-hour dietary recall questionnaire. After 1 year, both the control and the intervention groups showed satisfactory compliance rates (81 and 85%, respectively). In addition, preliminary results so far obtained reveal an unequivocal trend towards weight loss, a strong reduction in cholesterol levels, and a psychophysical feeling of well-being by women adopting the Mediterranean diet. The study is currently ongoing to verify the association of changes in serum and urine hormone levels and breast cancer risk in the intervention group.
Assuntos
Neoplasias da Mama/prevenção & controle , Dieta , Adulto , Idoso , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/etiologia , Estudos de Casos e Controles , Características Culturais , Dieta/psicologia , Feminino , Humanos , Região do Mediterrâneo/epidemiologia , Pessoa de Meia-Idade , Testosterona/sangueRESUMO
A quantitative method consisting of the modification of the zero net flux technique was used to determine the extracellular concentration of ascorbate. A carbon paste electrode (CPE) held at constant potential was combined with a microdialysis probe through which various concentrations of ascorbate were locally infused. In experiments with bilateral CPEs, one of which was combined with a dialysis probe, no difference was observed in either basal or stimulated ascorbate currents. Addition of different concentrations of ascorbate to the perfusion fluid produced rapid changes in the voltammetric current due to ascorbate oxidation. Irrespective of the concentration of ascorbate infused, the current returned to basal level when the perfusion was stopped. The return was found to be more rapid after infusion of concentrations of ascorbate higher than the extracellular concentration than after perfusion with ascorbate-free solutions. This demonstrates that homeostasis of ascorbate occurs in vivo. The calculated point of zero net flux was 416 +/- 66 microM (n = 6). This represents the extracellular concentration of ascorbate.