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1.
J Prev Med Hyg ; 56(4): E155-61, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26900330

RESUMO

INTRODUCTION: The objective of this paper is the comparison between two different technologies used for the removal of a uterine myoma, a frequent benign tumor: the standard technology currently used, laparoscopy, and an innovative one, colpoceliotomy. It was considered relevant to evaluate the real and the potential effects of the two technologies implementation and, in addition, the consequences that the introduction or exclusion of the innovative technology would have for both the National Health System (NHS) and the entire community. METHODS: The comparison between these two different technologies, the standard and the innovative one, was conducted using a Health Technology Assessment (HTA). In particular, in order to analyse their differences, a multi-dimensional approach was considered: effectiveness, costs and budget impact analysis data were collected, applying different instruments, such as the Activity Based Costing methodology (ABC), the Cost-Effectiveness Analysis (CEA) and the Budget Impact Analysis (BIA). Organisational, equity and social impact were also evaluated. RESULTS: The results showed that the introduction of colpoceliotomy would provide significant economic savings to the Regional and National Health Service; in particular, a saving of € 453.27 for each surgical procedure. DISCUSSION: The introduction of the innovative technology, colpoceliotomy, could be considered a valuable tool; one offering many advantages related to less invasiveness and a shorter surgical procedure than the standard technology currently used (laparoscopy).

2.
Psychiatry Res ; 278: 42-50, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31146140

RESUMO

Lithium is among the best proven treatments for patients diagnosed with Bipolar Disorder, however response to Lithium appears to be considerably variable among individuals and it has been suggested that this inconstancy in Lithium response could be genetically determined. Starting from this perspective, in the last few decades, a number of pharmacogenetic studies have attempted to identify genetic variants, which might be associated with response to Lithium in bipolar patients, in order to develop a pharmacogenetics test to tailor treatment on patients, identifying who will benefit the most from therapy with Lithium. Within this context, authors have critically reviewed pharmacogenetic studies of Lithium response in bipolar disorder, suggesting strategies for future work in this field. Computerized searches of PubMed and Embase databases, for studies published between 1998 and January 2018, was performed: 1162 studies were identified but only 37 relevant papers were selected for detailed review. Despite some interesting preliminary findings, the pharmacogenetics of Lithium and the development of a specific pharmacogenetics test in bipolar disorder appears to be a field still in its infancy, even though the advent of genome-wide association studies holds particular promise for future studies, which should include larger samples.


Assuntos
Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/genética , Estudo de Associação Genômica Ampla/métodos , Lítio/uso terapêutico , Farmacogenética/tendências , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Transtorno Bipolar/diagnóstico , Humanos , Farmacogenética/métodos
3.
Int J Immunopathol Pharmacol ; 20(3): 637-42, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17880777

RESUMO

Atherosclerosis is a complex disease that affects medium and large arteries, leading to the formation and progression of plaque. In this process the proteins play an essential role and as a consequence, proteomic-based strategies examining the protein content of cells or tissues could offer a useful approach for the study of plaque proteins. Due to the heterogeneous cell composition of plaque, proteome analysis of whole lesions is difficult, besides being also complicated by the presence of plasma proteins that cannot be completely eliminated. A good way to study variations in protein expression among series of gels is to construct a synthetic gel. This type of gel is obtained by averaging the positions, shapes and optical densities of spots in a given set of gels. To be included in the synthetic gel, spots must be found in at least three gels. To obtain a profile representative of the proteome of atherosclerotic plaque, cancelling its high variability, we constructed a synthetic gel using an average of ten carotid plaque samples. We then compared it with an equivalent synthetic gel constructed using ten plasma samples from the same carotid surgery patients. For the comparison of two synthetic gels (plasma/plaque) we could discriminate plasma proteins from plaque proteins. Besides analysis of spots common to plasma, the synthetic gel is useful to detect spots exclusive to plaque, thus simplifying a very complex mixture.


Assuntos
Proteínas Sanguíneas/análise , Estenose das Carótidas/metabolismo , Proteômica/métodos , Idoso , Estenose das Carótidas/sangue , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/cirurgia , Eletroforese em Gel Bidimensional , Endarterectomia das Carótidas , Feminino , Géis/química , Humanos , Concentração de Íons de Hidrogênio , Masculino , Ultrassonografia
4.
Biochim Biophys Acta ; 1454(1): 106-14, 1999 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-10354520

RESUMO

The synthesis of purine nucleotides has been studied in human peripheral blood lymphocytes from healthy subjects and patients affected by B-cell chronic lymphocytic leukemia (B-CLL). The rate of the synthesis was measured by following the incorporation of 14C-formate into the nucleotides of lymphocyte suspensions. The whole sequence AMP-->ADP-->ATP was found reduced in B-CLL lymphocytes; in the case of guanylates only the last step of the sequence GMP-->GDP-->GTP was significantly lower in the same cells. From the analysis of these results, combined with previous data, we conclude that purine metabolism undergoes an imbalancement during CLL, which is partially compensated, and point out the importance of studying concomitantly purine metabolism and nucleic acid synthesis in leukemia cells.


Assuntos
Nucleotídeos de Adenina/biossíntese , Nucleotídeos de Guanina/biossíntese , Leucemia Linfocítica Crônica de Células B/metabolismo , Linfócitos/metabolismo , Monofosfato de Adenosina/metabolismo , Idoso , Radioisótopos de Carbono , Células Cultivadas , Guanosina Monofosfato/metabolismo , Humanos , Inosina Monofosfato/metabolismo , Leucemia Linfocítica Crônica de Células B/sangue , Pessoa de Meia-Idade , Fatores de Tempo
5.
Biochim Biophys Acta ; 994(1): 52-8, 1989 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-2491792

RESUMO

The inhibition of highly purified rat liver L-threonine dehydratase (L-threonine hydro-lyase (deaminating), EC 4.2.1.16) by aminothiols (L-cysteine, D-cysteine, cysteamine) has been studied. Single inhibition experiments evaluated by Lineweaver-Burk and Dixon plots showed, in a given concentration range, partially (parabolic) competitive inhibitions, indicating two binding sites for each inhibitor. Double inhibition experiments revealed that the inhibition was antagonistic, the two inhibitors weakening each other's effect. Formation of EI1 and EI2 binary complexes, and ESI1, ESI2 and EI1I2 ternary complexes was demonstrated, while formation of the quaternary complex ESI1I2 was ruled out. It is assumed that one inhibitor-binding site coincides with the substrate-binding center while the second inhibitor-binding (allosteric, regulatory) site may comprise the pyridoxal-phosphate-binding SH group(s). The comparison between Km and Ki values and the evaluation of intracellular concentrations of L-threonine, L-cysteine and cysteamine suggest a possible physiological role of the inhibition.


Assuntos
Cisteamina/farmacologia , Cisteína/farmacologia , Fígado/enzimologia , Treonina Desidratase/antagonistas & inibidores , Animais , Sítios de Ligação , Ligação Competitiva , Cisteamina/metabolismo , Cisteína/metabolismo , Ditiotreitol/farmacologia , Ácido Edético/farmacologia , Masculino , Fosfato de Piridoxal/metabolismo , Ratos , Ratos Endogâmicos , Treonina Desidratase/metabolismo
6.
Biochim Biophys Acta ; 1158(3): 287-92, 1993 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-8251529

RESUMO

Oxygen-derived radicals have been suggested to produce tissue injury during endotoxic shock by initiating lipid peroxidation. In order to investigate the induction of lipid peroxidation by Escherichia coli 0111:B4 lipopolysaccharide (LPS) on hepatocytes, malondialdehyde (MDA) and superoxide dismutase (SOD) activity have been evaluated in vivo and in vitro using two experimental models: rat liver after the establishment of endotoxic reversible shock, and cultured hepatocytes after treatment with LPS. Liver MDA levels were increased in vivo during the acute-phase of endotoxic shock, decreasing below control values in the recovery phase. An inverse pattern was obtained when SOD activity was measured, consistent with an active system of cellular protection. Similar results were obtained in vitro after treatment of cultured hepatocytes with LPS (50 micrograms/ml), thus indicating that a direct LPS cytotoxic effect on hepatocytes exits during the endotoxic process. The direct LPS interaction induced alterations in Ca2+ permeability of hepatocyte plasma membrane as detected by flow cytometry using the fluorescent probe Indo-1.


Assuntos
Escherichia coli , Lipopolissacarídeos/farmacologia , Fígado/efeitos dos fármacos , Animais , Cálcio/análise , Células Cultivadas , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Indução Enzimática/efeitos dos fármacos , Citometria de Fluxo , Peroxidação de Lipídeos , Fígado/metabolismo , Masculino , Malondialdeído/análise , Ratos , Ratos Wistar , Choque Séptico/etiologia , Superóxido Dismutase/biossíntese
7.
Biochim Biophys Acta ; 1077(2): 233-40, 1991 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-2015295

RESUMO

The effects exerted by carbamoyl phosphate (CP) and cyanate (KCNO) on rat liver L-threonine deaminase have been studied. The two compounds showed that same effects, inhibiting through a competitive mechanism both the holoenzyme and the dialyzed enzyme; inhibition was more evident for the latter. Ki values, both for L-threonine and pyridoxal 5'-phosphate (PLP), were lower for the apoenzyme and the inhibitors also affected the Km of the apoenzyme for PLP. The effects of CP and KCNO are mainly due to an interference in the association reaction apoenzyme + PLP in equilibrium holoenzyme This was clearly demonstrated by the fact that, when PLP was incubated with CP or KCNO, it failed to enhance the activity of the holoenzyme nor did it reactivate the resolved apoenzyme. Such interference of CP and KCNO in the L-threonine deaminase activity was mainly due to a specific mechanism, the formation of a new derivative of PLP. The reaction of PLP with either CP or KCNO occurred readily, at low concentrations, under physiological conditions. The new compound was identified as 3,4-dihydro-2H-pyrido[3,4-e]1,3-oxazin-2-one derivative by ultraviolet-visible spectra, elemental analysis, infrared, NMR and MS spectra. In this paper we formulate the hypothesis that this compound is involved in the regulation of the CP and PLP intracellular content and in the control of PLP dependent enzymes.


Assuntos
Carbamoil-Fosfato/farmacologia , Fígado/enzimologia , Fosfato de Piridoxal/análogos & derivados , Treonina Desidratase/antagonistas & inibidores , Animais , Cianatos/farmacologia , Espectroscopia de Ressonância Magnética , Masculino , Espectrometria de Massas , Fosfato de Piridoxal/biossíntese , Ratos , Ratos Endogâmicos , Análise Espectral
8.
Biochim Biophys Acta ; 1092(1): 1-6, 1991 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-2009305

RESUMO

In this study, the fluorescent Ca2+ probe fura-2 and the fluorescent pH indicator BCECF have been used to monitor cytosolic free Ca2+ and intracellular pH (pHi), respectively, in isolated and cultured hepatocytes treated with Escherichia coli O111:B4 endotoxin. Uptake of 45Ca2+ was also measured to study the effect of endotoxin on the extracellular calcium influx. Endotoxin treatment produced a progressive increase of cytosolic Ca2+ in a dose-dependent manner caused by both induction of a significant release of Ca2+ from intracellular stores and stimulation of the extracellular calcium influx. The perturbation of Ca2+ homeostasis by endotoxin may cause an abnormal stimulation of physiological processes, developing lethal cell injury. Endotoxin also produced a significant decrease in the pHi of hepatocytes which can justify important metabolic alterations during endotoxicosis.


Assuntos
Cálcio/metabolismo , Endotoxinas/farmacologia , Escherichia coli , Fígado/efeitos dos fármacos , Animais , Células Cultivadas , Citosol/efeitos dos fármacos , Fluoresceínas , Fura-2 , Concentração de Íons de Hidrogênio , Fígado/metabolismo , Masculino , Ratos , Ratos Endogâmicos
9.
Biochim Biophys Acta ; 1204(2): 250-6, 1994 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-8142466

RESUMO

We examined the effects on alanine aminotransferase and aspartate aminotransferase of different aminothiols (L-cysteine, D-cysteine, cysteamine, L-cysteine ethyl ester, L-cysteine methyl ester) and several vitamin B-6 derivatives (pyridoxal, pyridoxamine, pyridoxol, pyridoxol 5'-phosphate), before and after treatment with KOCN, which transforms these molecules into the corresponding carbamoyl derivatives. Only GPT, and not GOT, was specifically inhibited by L-cysteine and, to a lesser extent, by D-cysteine. The association reaction: PLP + apo GPT<-->holo GPT was inhibited by the vitamin B-6 derivatives, and this inhibition was prevented by pretreatment of the vitamin B-6 derivatives with KOCN. All the observed effects occurred at pH 7, 37 degrees C, at mM and even lower concentrations of reagents. Hence, they all potentially play a physiological role, in the regulation of the PLP dependent enzymes and of the vitamin B-6 levels in the cell.


Assuntos
Alanina Transaminase/metabolismo , Aspartato Aminotransferases/metabolismo , Cisteína/farmacologia , Piridoxina/análogos & derivados , Alanina Transaminase/antagonistas & inibidores , Aspartato Aminotransferases/antagonistas & inibidores , Cianatos/farmacologia , Cisteína/análogos & derivados , Relação Dose-Resposta a Droga , Concentração de Íons de Hidrogênio , Fosfato de Piridoxal/análise , Fosfato de Piridoxal/farmacologia , Piridoxamina/análogos & derivados , Piridoxamina/análise , Piridoxamina/farmacologia , Estereoisomerismo , Temperatura
10.
Biochim Biophys Acta ; 926(2): 177-85, 1987 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-3117120

RESUMO

We examined the effects of a two-thirds hepatectomy in the adult rat on the activities of the three L-threonine-degrading enzymes, L-threonine dehydratase, L-threonine aldolase and L-threonine dehydrogenase. Noticeable variations were observed which did not occur in either sham-operated or turpentine-treated rats and were not linked to food intake. They were considered specific to the regenerating liver. When the reactions were followed in vitro, L-threonine deaminase and L-threonine aldolase were significantly lower for the first 12-24 h: L-threonine dehydrogenase decreased only after 48 h. These results are linked to a decrease in the enzyme concentration in the tissue. L-Serine and L-threonine liver concentrations increased 2-3-fold during the same periods. When the activities were evaluated in vivo, the levels of the first two enzymes remained constant for 24 h, but increased after 48 h; L-threonine dehydrogenase increased between 12 and 48 h. The in vivo activity of the enzymes was reflected by total L-threonine degradation, which had a single sharp peak at 48 h. The asynchronous variations in enzyme activity are related to the differences in protein metabolism which occur in the regenerating liver, and are the consequence of a new transient differential control. The changes observed are significant in liver regeneration; they regulate the consumption and the serum and liver levels of L-serine and L-threonine, setting them aside for protein synthesis. They minutely control the flux of amino acids toward gluconeogenesis, since, during the first 48 h after partial hepatectomy, the production of glucose is ensured principally by lactate; the contribution of L-threonine seems to be more significant only at 48 h. These findings are useful in the study of the regulation of the enzymes involved in amino acid metabolism during liver regeneration.


Assuntos
Regeneração Hepática , Fígado/enzimologia , Treonina/metabolismo , Oxirredutases do Álcool/metabolismo , Animais , Glicina/metabolismo , Glicina Hidroximetiltransferase/metabolismo , Hepatectomia , Cinética , Fígado/efeitos dos fármacos , Masculino , Ratos , Ratos Endogâmicos , Serina/metabolismo , Treonina Desidratase/metabolismo , Terebintina/farmacologia
11.
Biochim Biophys Acta ; 1157(1): 9-14, 1993 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-8499482

RESUMO

Nitrogen metabolism was investigated in regenerating liver-bearing rats through the following parameters: (1) liver aminoacid content, (2) plasma and urinary urea and creatinine, (3) plasma and urinary oxypurines, uric acid and allantoin. Two groups of aminoacids were considered: (1) the essential aminoacids (phenylalanine, tyrosine, isoleucine, lysine, leucine, valine, arginine, histidine and methionine); (2) the non-essential aminoacids (aspartic acid, asparagine, glutamic acid, glutamine, alanine, glycine, serine, threonine and proline). Some of the first group tended to decrease, and those of the second group to increase, immediately after partial hepatectomy. Few ketogenic aminoacids are probably oxidized to provide energy. The flux of aminoacids for gluconeogenesis is minutely controlled, therefore, those of the second group being spared at first and set aside for protein synthesis, which increases on the second and third days after partial hepatectomy. Plasma and urinary urea, oxypurines, uric acid and allantoin did not show any significant variations after partial hepatectomy. The conclusion emerging from the present research is that, although variations in aminoacid composition and metabolism and in purine nucleotide metabolism have been demonstrated to occur in the regenerating liver, the overall nitrogen catabolism, as reflected by the principal end products, does not undergo substantial variations. The remaining liver is able to fulfil this function.


Assuntos
Regeneração Hepática , Fígado/metabolismo , Nitrogênio/metabolismo , Alantoína/sangue , Alantoína/urina , Aminoácidos/metabolismo , Animais , Creatina/sangue , Creatina/urina , Hepatectomia , Hipoxantina , Hipoxantinas/urina , Tamanho do Órgão , Ratos , Ratos Wistar , Ureia/sangue , Ureia/urina , Ácido Úrico/sangue , Ácido Úrico/urina , Xantina , Xantinas/urina
12.
Biochim Biophys Acta ; 1244(1): 49-52, 1995 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-7766668

RESUMO

In a previous paper, we showed inhibition of rat liver L-threonine dehydrogenase by a preparation obtained by dialysis and concentration from rat liver mitochondria stored at -20 degrees C for 7-10 days (Pagani, R., Leoncini, R., Guerranti, R. and Marinello, E. (1990) It. J. Biochem. 39, 106-114). The chemical composition of the fraction containing the unknown 'inhibitor' has now been studied and identified as D-3-hydroxybutyrate (D3HB).


Assuntos
Oxirredutases do Álcool/antagonistas & inibidores , Mitocôndrias Hepáticas/enzimologia , Ácido 3-Hidroxibutírico , Animais , Hidroxibutirato Desidrogenase/metabolismo , Hidroxibutiratos/farmacologia , Masculino , Ratos , Ratos Wistar
13.
Biochim Biophys Acta ; 1568(1): 45-52, 2001 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-11731084

RESUMO

Rat liver L-threonine dehydrogenase is a mitochondrial enzyme which transforms L-threonine either into aminoacetone or into acetyl-CoA. We show that it is inhibited by several fatty acids and their derivatives: short chain fatty acids, L-2-hydroxybutyrate and D-3-hydroxybutyrate, long chain fatty acids, such as lauric acid, myristic acid, palmitic and stearic acids, bicarboxylic acids such as malonic acid and its derivatives methyl- and hydroxymalonic acids. The inhibition occurs at low and physiological concentrations of such compounds, which are normally present and metabolized in mitochondria. It presumably plays a role in the physiology of acetyl-CoA-dependent formation of fatty acids and ketobodies, in L-threonine-dependent gluconeogenesis, and in the regulation of L-threonine metabolism by L-threonine dehydrogenase and L-threonine deaminase.


Assuntos
Oxirredutases do Álcool/antagonistas & inibidores , Ácidos Graxos/farmacologia , Fígado/efeitos dos fármacos , Ácido 3-Hidroxibutírico/farmacologia , Animais , Ácidos Dicarboxílicos/farmacologia , Gluconeogênese/efeitos dos fármacos , Hidroxibutiratos/farmacologia , Cinética , Fígado/enzimologia , Masculino , Modelos Químicos , Ratos , Ratos Wistar , Estereoisomerismo
14.
Biochim Biophys Acta ; 1425(2): 411-8, 1998 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-9795257

RESUMO

When a highly purified preparation of rat liver l-threonine deaminase (l-TDH, EC 4.2.1.16) was 99% inactivated by dialysis, removing bound pyridoxal 5'-phosphate (PLP), the apoenzyme was reactivated not only by PLP but also by pyridoxamine 5'-phosphate (PMP). When purified by HPLC, the commercial PMP used in the incubation mixture was found to contain only extremely small amounts of PLP, which could not account for restoration of l-threonine dehydratase activity. HPLC analysis of the assay mixtures showed that during incubation, sufficient PLP had been formed for reactivation of the apoenzyme. The apoenzyme evidently bound PMP and triggered transamination between PMP and the keto acids, which either contaminated, or were formed by the minimal amount of PLP-holoenzyme always present even in the dialyzed preparation. When sufficient PLP was formed, the PLP-holoenzyme and the original 'true' l-threonine dehydratase activity were restored. When PMP was incubated with the apoenzyme in the presence of small quantities of keto acids (pyruvate or 2-oxobutyrate) small amounts of l-alanine or l-aminobutyrate were formed. The reaction was not reversible; l-alanine and l-aminobutyrate did not react with the PLP-holoenzyme. No transaminating activity occurred with other amino acids. These results show that l-threonine dehydratase exists in two forms: the well known stable apoenzyme-PLP (hydrolase deaminating) and the transient apoenzyme-PMP (non-reversible half-transaminating). Half-transamination has the biological role of keeping the activity of the 'true' l-TDH constant and of regulating intracellular levels of pyruvate, alanine, oxobutyric acid, l-aminobutyric acid, l-threonine and l-serine.


Assuntos
Reativadores Enzimáticos/farmacologia , Fígado/efeitos dos fármacos , Fosfato de Piridoxal/farmacologia , Piridoxamina/análogos & derivados , Treonina Desidratase/metabolismo , Acetoacetatos/metabolismo , Alanina/metabolismo , Animais , Apoenzimas/metabolismo , Fígado/enzimologia , Masculino , Piridoxamina/farmacologia , Ácido Pirúvico/metabolismo , Ratos , Ratos Wistar , Treonina Desidratase/química , Treonina Desidratase/isolamento & purificação
15.
Biochim Biophys Acta ; 1117(1): 1-6, 1992 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-1627585

RESUMO

A simple procedure is described for the assay of liver uric acid and allantoin and their specific radioactivity after administration of a radioactive precursor. Uric acid was quantified by the uricase reaction in liver trichloroacetic acid (TCA) extracts. The 'true' allantoin content of the liver could be estimated only after precipitation with Hg-acetate, a step by which the standard allantoin was also quantitatively recovered. Crude extracts lead to the evaluation of 'apparent' allantoin. For the determination of specific radioactivity, the Hg-acetate precipitate was further purified by ion-exchange chromatography. The purity of the two metabolites was confirmed by ultraviolet absorbance spectra, HPLC, constancy of specific radioactivity and the absence of amino acids. The incorporation of [14C]formate into uric acid and allantoin in the liver was studied by this procedure. The radioactivity in allantoin was several-fold higher than that in uric acid up to 60 min after administration of the precursor. This quite unexpected result is not easily explained on the basis of current knowledge.


Assuntos
Alantoína/isolamento & purificação , Fígado/metabolismo , Ácido Úrico/isolamento & purificação , Animais , Radioisótopos de Carbono , Precipitação Química , Cromatografia por Troca Iônica , Formiatos/metabolismo , Masculino , Mercúrio , Ratos , Ácido Tricloroacético , Urato Oxidase
16.
Biochim Biophys Acta ; 1182(3): 317-22, 1993 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-8399367

RESUMO

The purine nucleotide content was examined in various cells before and after HIV-1 virus infection: healthy peripheral blood lymphocytes (PBL) and cultured PBL after infection; the PBL of asymptomatic, ARC and AIDS patients. In all cases, changes in purine nucleotide concentrations were observed. The pattern of purine nucleosides and nucleobases was also evaluated by HPLC in PBL of controls and patients. The analysis was integrated by following the incorporation of a labelled precursor ([14C]formate) into purine nucleotides, which was investigated as an indication of the rate of purine metabolism in these cells. Many interesting variations in the catabolic and of anabolic pathways were observed, demonstrating that the viral penetration affects purine nucleotide metabolism. These results suggest interesting perspectives in AIDS research.


Assuntos
Complexo Relacionado com a AIDS/metabolismo , Síndrome da Imunodeficiência Adquirida/metabolismo , Soropositividade para HIV/metabolismo , HIV-1 , Linfócitos/metabolismo , Nucleotídeos de Purina/metabolismo , Adulto , Sobrevivência Celular , Feminino , Humanos , Cinética , Masculino , Pessoa de Meia-Idade , Nucleotídeos de Pirimidina/metabolismo
17.
Eur J Cell Biol ; 65(1): 200-5, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7889990

RESUMO

During endotoxic shock, the liver exerts an endotoxin (lipopolysaccharide, LPS) clearance function with the participation of both sinusoidal (mainly Kupffer and endothelial cells) and parenchymal cells. In order to determine the specificity and diversity of response of each liver cell type, the effect of Escherichia coli 0111:B4 endotoxin (LPS) on intracellular Ca2+ content and reactive oxygen metabolite production in rat liver Kupffer, endothelial and parenchymal cells, was evaluated by flow cytometry during short treatment times (from 0-2 min) with a low dose of LPS (10 micrograms/ml). Concerning sinusoidal cells, LPS produced a significant increase of intracellular Ca2+ in both endothelial and Kupffer cells. The LPS effect on Kupffer cells was higher than on endothelial cells. When intracellular reactive oxygen metabolite production was evaluated in LPS-treated sinusoidal cells, a fast and significant increase of Kupffer cells in activated state (cells with a high reactive oxygen intermediate production) was observed. However, endothelial cells did not show LPS-induced changes in their intracellular reactive oxygen metabolite content. All these results support a rapid activation of liver Kupffer cells by endotoxin consistent with the major role of this cellular type as active first line of defense during endotoxic shock. The liver endothelial cells are also involved in the first steps of the cell damage showing intracellular Ca2+ alterations. Liver parenchymal cells did not show any response at these experimental conditions (short treatment time and low LPS dose) indicating that longer treatment times are needed for LPS binding and action in agreement with previous studies.


Assuntos
Cálcio/metabolismo , Células de Kupffer/metabolismo , Lipopolissacarídeos/farmacologia , Fígado/metabolismo , Animais , Endotélio/citologia , Endotélio/metabolismo , Estudos de Avaliação como Assunto , Citometria de Fluxo , Radicais Livres , Fígado/citologia , Masculino , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo
18.
Eur J Cell Biol ; 43(2): 243-6, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3297705

RESUMO

The biphasic behaviour observed in endotoxin-induced shock attributed to a direct interaction of bacterial lipopolysaccharides with the cell membrane and an indirect activation of multiple homeostatic regulatory mechanisms, cannot be completely elucidated with in vivo studies. In primary cultures of adult rat hepatocytes, lipopolysaccharide from Escherichia coli 0111:B4 affects the cytochrome P450 levels directly; however, albumin and aspartate aminotransferase secretion are induced by some mediators present in the sera of animals in acute-phase shock.


Assuntos
Escherichia coli , Lipopolissacarídeos/toxicidade , Fígado/patologia , Ácido Aminolevulínico/farmacologia , Animais , Aspartato Aminotransferases/metabolismo , Células Cultivadas , Sistema Enzimático do Citocromo P-450/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Ratos , Ratos Endogâmicos , Albumina Sérica/metabolismo
19.
Neuroscience ; 123(1): 75-85, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14667443

RESUMO

Voltage-dependent calcium channels (VDCC) have a key role in neuronal function transforming the voltage signals into intracellular calcium signals. They are composed of the pore-forming alpha(1) and the regulatory alpha(2)delta, gamma and beta subunits. Molecular and functional studies have revealed which alpha(1) subunit gene product is the molecular constituent of each class of native calcium channel (L, N, P/Q, R and T type). Electrophysiological and immunocytochemical studies have suggested that at adult mouse motor nerve terminal (MNT) only P/Q type channels, formed by alpha(1A) subunit, mediate evoked transmitter release. The generation of alpha(1A)-null mutant mice offers an opportunity to study the expression and localization of calcium channels at a synapse with complete loss of P/Q calcium channel. We have investigated the expression and localization of VDCCs alpha(1) and beta subunits at the wild type (WT) and knockout (KO) mouse neuromuscular junction (NMJ) using fluorescence immunocytochemistry. The alpha(1A) subunit was observed only at WT NMJ and was absent at denervated muscles and at KO NMJ. The subunits alpha(1B), alpha(1D) and alpha(1E) were also present at WT NMJ and they were over- expressed at KO NMJ suggesting a compensatory expression due to the lack of the alpha(1A). On the other hand, the beta(1b), beta(2a) and beta(4) were present at the same levels in both genotypes. The presence of other types of VDCC at WT NMJ indicate that they may play other roles in the signaling process which have not been elucidated and also shows that other types of VDCC are able to substitute the alpha(1A) subunit, P/Q channel under certain pathological conditions.


Assuntos
Canais de Cálcio Tipo L/biossíntese , Canais de Cálcio Tipo N/biossíntese , Canais de Cálcio/biossíntese , Proteínas de Transporte de Cátions , Proteínas do Tecido Nervoso/biossíntese , Junção Neuromuscular/metabolismo , Animais , Canais de Cálcio/deficiência , Canais de Cálcio/genética , Canais de Cálcio Tipo L/deficiência , Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo N/deficiência , Canais de Cálcio Tipo N/genética , Canais de Cálcio Tipo R , Regulação da Expressão Gênica/fisiologia , Camundongos , Camundongos Knockout , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética
20.
Mol Cell Endocrinol ; 119(2): 123-7, 1996 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-8807631

RESUMO

The effect of testosterone on the morphology and biochemistry of adult castrated rat liver is described. Castration decreases mean weight and volume of hepatocytes, volume and surface area of sinusoidal lumen, and apparently increases cell number per g of tissue. These variations indicate cell distress. Testosterone administration restored sinusoidal volume and surface area, indicating a true hyperplastic response and improved trophic conditions. Acid soluble nucleotides, RNA and DNA content were lower after castration, being partially restored after testosterone treatment. This restoration, however, was only statistically significant for total guanylate. We concluded that testosterone deficiency and administration exerts a specific effect on the liver in terms of morphological and biochemical changes. Purine nucleotide metabolism is probably the first target of hormonal action, since its changes are the most significant and useful to explain all the other observations.


Assuntos
Fígado/efeitos dos fármacos , Nucleotídeos de Purina/metabolismo , Testosterona/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Núcleo Celular , Tamanho Celular/efeitos dos fármacos , DNA/análise , Fígado/química , Fígado/citologia , Fígado/metabolismo , Masculino , Orquiectomia , Tamanho do Órgão/efeitos dos fármacos , RNA/análise , Ratos , Ratos Wistar , Testosterona/fisiologia
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