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1.
Can J Gastroenterol ; 22(3): 255-8, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18354754

RESUMO

BACKGROUND: Infection with different genotypes of virulent Helicobacter pylori strains (cytotoxin-associated gene A [CagA]- and/or vacuolating cytotoxin A [VacA]-positive) can play a role in the development of atrophic gastritis, duodenal ulcer (DU) and gastric cancer (GC). OBJECTIVE: To determine whether patients with GC and H pylori-negative histological staining had previously been infected with H pylori CagA- and/or VacA-positive virulent strains. METHODS: Twenty-three GC patients with a mean (+/- SD) age of 68.14+/-9.8 years who tested H pylori-negative on histological staining took part in the study. Three control groups were included. The first group comprised 19 patients with past H pylori infection and DUs eradicated 10 years earlier, with a mean age of 58+/-18.2 years. H pylori-negative status for this group was determined every year with Giemsa staining, and follow-up testing occured 120+/-32 months (mean +/- SD) after therapy. The subsequent control groups included 20 asymptomatic children, with a mean age of 7+/-4.47 years, and with H pylori-negative fecal tests; the final group contained 30 patients without clinical symptoms of H pylori infection, with a mean age of 68+/-11.6 years, who tested H pylori-negative by histological staining. RESULTS: Prevalence of CagA and VacA seropositivity, respectively was 82.6% and 73.91% in GC patients; 84.2% and 84.2% in H pylori-negative DU patients; 25% and 5% in H pylori-negative children; and 36.6% and 16.6% in the patients without clinical symptoms on histological staining. CagA and VacA antibody positivity was not significantly different between GC patients and patients with DUs that had been eradicated 10 years earlier. Significant positivity was found between the children's group and the H pylori-negative (with past DUs) group (P<0.001). A statistically significant difference was found in age between groups (P<0.03). CONCLUSIONS: Patients with GC, even when H pylori-negative at the time of the present study, may have been infected by H pylori before the onset of the disease, as confirmed by CagA and VacA seropositivity. These data reinforce the hypothesis that H pylori may be a direct carcinogenic agent of GC.


Assuntos
Anticorpos Antibacterianos/análise , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Neoplasias Gástricas/imunologia , Neoplasias Gástricas/microbiologia , Adulto , Idoso , Corantes Azur , Feminino , Mucosa Gástrica/microbiologia , Humanos , Memória Imunológica/fisiologia , Masculino , Pessoa de Meia-Idade , Virulência
2.
Drugs Exp Clin Res ; 31(4): 161-8, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16223206

RESUMO

Benzodiazepine-like compounds (BZDs), either taken with the diet or synthesized by intestinal bacterial flora, may represent a precipitating factor for hepatic encephalopathy (HE) in cirrhotic patients. We evaluated whether a diet and/or treatment with rifaximin or lactulose can reduce serum concentrations of BZDs in 18 cirrhotic patients without HE. Patients were given a standard diet for 7 days to keep the dietary intake of BZDs constant and were then randomized to a 7-day treatment with rifaximin 1,200 mg/day, lactulose 10-20 g three times daily, or placebo. Blood samples were collected at enrollment, at the end of the diet and drug treatment periods, and 7 days after the drug was stopped (follow-up). Serum concentrations of BZDs were measured by a radioligand binding technique after high-performance liquid chromatography extraction and purification and were expressed as diazepam equivalents (DE). No change in serum BZD concentrations was observed during the diet, while a statistically significant decrease from 105.6 +/- 66.5 to 63.5 +/- 49.5 pmol DE/ml was achieved in rifaximin-treated patients (p < 0.05) but not in patients treated with lactulose or placebo. During the followup, serum BZD concentrations returned to 104.5 +/- 74.0 pmol DE/ml in rifaximin-treated patients (p < 0.05 vs. end-treatment values), while no significant change was observed in the lactulose- and placebo-treated patients. These data indicate that control of bacterial flora with cyclic administration of rifaximin plays a pivotal role in avoiding increased plasma concentrations of BZDs, which represent a precipitating factor for HE inpatients with severe liver disease.


Assuntos
Benzodiazepinas/sangue , Lactulose/farmacologia , Cirrose Hepática/sangue , Rifamicinas/farmacologia , Adulto , Idoso , Cromatografia Líquida de Alta Pressão , Avaliação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Placebos , Rifaximina
3.
Transplantation ; 62(6): 764-7, 1996 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-8824474

RESUMO

The observation that there are episodes of encephalopathy in liver cirrhosis patients after orthotopic liver transplantation, despite a well functioning graft and despite the lack of cerebral complications, prompted us to investigate the potential role of circulating benzodiazepine-like compounds in these episodes. The plasma levels of benzodiazepines were examined in 14 liver cirrhotic patients before and after transplantation. The benzodiazepines in the fluids infused during surgery and in individual bags of blood administered after surgery to 4 of these patients were also assayed. Herein we report that benzodiazepines accumulating in the blood of some transplanted patients appear to derive from blood transfusions utilized during surgery. The analysis of the types of benzodiazepines present in the blood utilized for transfusions suggests the use of commercial benzodiazepines by the donors. These compounds seem to be able to precipitate hepatic encephalopathy in patients with preexisting encephalopathy. Hence we suggest not using benzodiazepine consumers as blood donors, at least for patients with encephalopathy undergoing to liver transplantation.


Assuntos
Benzodiazepinas/efeitos adversos , Doadores de Sangue , Encefalopatia Hepática/induzido quimicamente , Transplante de Fígado , Complicações Pós-Operatórias/induzido quimicamente , Reação Transfusional , Adulto , Benzodiazepinas/sangue , Benzodiazepinas/farmacocinética , Encefalopatia Hepática/etiologia , Humanos , Fígado/metabolismo , Cirrose Hepática/complicações , Cirrose Hepática/cirurgia , Masculino , Pessoa de Meia-Idade
4.
Arch Ophthalmol ; 104(11): 1630-1, 1986 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3778277

RESUMO

Vitreous fluorophotometry was performed in young patients (8 to 19 years old) affected by insulin-dependent diabetes mellitus, with no signs of diabetic retinopathy. Oral fluorescein was administered, and measures were used to prevent hypoglycemia during the examination. The results showed a breakdown of the blood-retinal barrier in nine (43%) of the 21 patients. The oral fluorescein method allows a satisfactory evaluation of ocular fluorescence profiles, with minimal risk of systemic side effects.


Assuntos
Diabetes Mellitus Tipo 1/patologia , Corpo Vítreo/patologia , Administração Oral , Adolescente , Adulto , Criança , Feminino , Fluoresceína , Fluoresceínas , Fluorometria , Humanos , Masculino , Fotometria , Vasos Retinianos/metabolismo
5.
Regul Pept ; 74(1): 31-4, 1998 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-9657356

RESUMO

Cholesterol is used by cells for biosynthetic processes and for steroid synthesis. Although the role of cholesterol in tumorigenesis is not clear it is known that steroids are important factors in human carcinogenesis. A polypeptide, diazepam binding inhibitor (DBI), which is an endogenous ligand for peripheral benzodiazepine receptors enhances steroidigenesis by promoting cholesterol delivery to the inner mitochondrial membrane which represents the rate-limiting step of steroid biosynthesis. We have assayed the total cholesterol (TC) and the DBI plasma concentrations in patients with liver cirrhosis complicated by hepatocellular carcinoma (HCC) in comparison with those of uncomplicated liver cirrhosis. TC and DBI levels have been studied in 73 cirrhotic patients and in 23 patients with HCC. Both TC and DBI levels were higher in HCC patients when compared with age, sex and Child-Pugh class matched cirrhotic controls. The values (mean+/-S.D.) in patients in Child-Pugh class B and C with and without HCC were respectively 128+/-30 mg/dl vs. 106+/-27 mg/dl (P < 0.01) and 2.05+/-0.78 pmol/ml vs. 0.78+/-0.84 pmol/ml (P < 0.0001). The data may be the result of the metabolic influence of tumors that enhances steroid biosynthesis during tumor proliferation.


Assuntos
Carcinoma Hepatocelular/sangue , Proteínas de Transporte/metabolismo , Colesterol/sangue , Cirrose Hepática/sangue , Neoplasias Hepáticas/sangue , Adulto , Inibidor da Ligação a Diazepam , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Receptores de GABA-A/metabolismo , Regulação para Cima
6.
Life Sci ; 65(21): 2223-31, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10576594

RESUMO

The peripheral benzodiazepine receptor system triggers intracellular metabolic events and has been associated with cell proliferation. Its endogenous ligand, the diazepam binding inhibitor, contributes to steroidogenesis by promoting cholesterol delivery to the inner mitochondrial membrane. The present study was undertaken to verify whether this system is altered in tumors sited in the liver. Peripheral benzodiazepine receptors and diazepam binding inhibitor were studied using immunocytochemistry and in situ hybridization in 9 human tumors sited in the liver, in liver hyperplasia, cirrhotic nodular regeneration, intestinal adenocarcinoma and in surrounding non-tumoral tissue. Immunocytochemical staining and in situ hybridization demonstrated that peripheral benzodiazepine receptors and diazepam binding inhibitor were more prominently expressed in neoplastic cells than in non-tumoral tissue. They were present in the same cells, suggesting that diazepam binding inhibitor may act in an intracrine manner in these cells. Higher peripheral benzodiazepine receptors and diazepam binding inhibitor expression in tumor cells suggest an implication of this system in the metabolism of neoplastic cells. Furthermore the evaluation of peripheral benzodiazepine receptor and diazepam binding inhibitor expression might be useful in evaluating malignancy and in diagnostic approaches of tumors in liver tissue.


Assuntos
Proteínas de Transporte/biossíntese , Neoplasias Hepáticas/metabolismo , Sistema Nervoso Periférico/metabolismo , Receptores de GABA-A/biossíntese , Idoso , Inibidor da Ligação a Diazepam , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Hibridização In Situ , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/análise , RNA Mensageiro/biossíntese
7.
Life Sci ; 63(14): 1269-80, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9771915

RESUMO

Increased number of peripheral benzodiazepine receptors (PBRs) have been found in some tumors outside the liver. The present study was to verify whether the PBR system is altered in hepatocellular carcinoma (HCC). The levels of endogenous benzodiazepine-like compounds (BZDs), measured by radioreceptor binding technique after HPLC purification and the endogenous ligand for PBRs, termed diazepam binding inhibitor (DBI), measured by radioimmunoassay utilizing a specific antibody for human DBI, were studied in the blood of 15 normal subjects, 12 liver cirrhosis and 10 patients with HCC. The levels of BZDs in serum were increased hundred fold in liver cirrhosis patients and slightly elevated in HCC patients. DBI was found to be increased in HCC patients. The binding recognition sites for PBRs (Bmax) were increased 4 to 7 fold in HCC tissue in comparison with that found in non-tumoral liver tissue (NTLT). On the contrary the concentrations of DBI were found to be significantly decreased in HCC tissue in comparison with the respective NTLT. These results seem to suggest an implication of PBRs and of their putative endogenous ligands in the metabolism of these neoplastic cells and possibly in their proliferation. The up-regulation of PBRs found in HCC tissue seems to indicate an increased functional activity of these receptors and opens up the possibility of new pharmacological and diagnostic approaches while the changes in the circulating endogenous ligands for the above receptors might be envisaged as early markers of tumorigenesis in liver cirrhosis.


Assuntos
Carcinoma Hepatocelular/química , Neoplasias Hepáticas/química , Receptores de GABA-A/análise , Adulto , Idoso , Benzodiazepinas/sangue , Proteínas de Transporte/sangue , Inibidor da Ligação a Diazepam , Feminino , Humanos , Fígado/química , Masculino , Pessoa de Meia-Idade , Regulação para Cima
8.
Adv Exp Med Biol ; 467: 155-67, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10721052

RESUMO

Oxindole administration (1-100 mg/kg i.p.) to mammals decreases locomotor activity, reduces muscular tone and blood pressure and at larger doses causes coma and death. Utilizing both HPLC and GC/MS, we showed that oxindole is present in the blood, brain and other organs of several animal species, including humans. We demonstrated that oxindole is a tryptophan metabolite able to significantly decrease neuronal excitability by modifying the function of voltage-operated sodium channels. Its synthesis requires the availability of indole, which is formed in the gut. When liver function is impaired, a sufficient amount of indole reaches systemic circulation and is oxidized into oxindole, which seems to be one of the responsible agents for the neurological symptoms found in the course of liver impairment.


Assuntos
Encefalopatia Hepática/tratamento farmacológico , Indóis/metabolismo , Indóis/toxicidade , Triptofano/metabolismo , Animais , Humanos , Hipnóticos e Sedativos/farmacologia , Mamíferos , Atividade Motora/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/fisiologia
9.
Hepatogastroenterology ; 45(19): 44-7, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9496485

RESUMO

Mesenteric vein thrombosis is a rare disorder which can develop rapidly with intestinal infarction or subacutely with abdominal pain due to intestinal ischemia. Despite the availability of modern diagnostic tools, which allow an early diagnosis in most cases, the mortality from this disease has not significantly diminished over the years. The problem is that the syndrome is rare and unusual and the clinical presentation is usually vague or confusing. Particularly in cirrhotic patients, this diagnosis requires the exclusion of several other complications of liver disease, like spontaneous bacterial peritonitis, tense ascites or portal thrombosis. Here, we report the occurrence of acute mesenteric vein thrombosis in two patients with liver cirrhosis. Severe subcontinuous abdominal pain out of proportion to the physical findings and abdominal distension were the major symptoms in both patients. Magnetic resonance imaging in one case and ultrasound scan with color Doppler followed by computed tomography in the other patient confirmed the diagnosis and enabled an appropriate early therapy to be undertaken.


Assuntos
Dor Abdominal/etiologia , Cirrose Hepática/complicações , Oclusão Vascular Mesentérica/complicações , Trombose/complicações , Doença Aguda , Idoso , Carcinoma Hepatocelular/complicações , Humanos , Neoplasias Hepáticas/complicações , Imageamento por Ressonância Magnética , Masculino , Oclusão Vascular Mesentérica/diagnóstico , Veias Mesentéricas , Pessoa de Meia-Idade , Trombose/diagnóstico , Tomografia Computadorizada por Raios X , Ultrassonografia Doppler em Cores
10.
Hepatogastroenterology ; 45(24): 2344-7, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9951920

RESUMO

The association of primary sclerosing cholangitis and celiac disease is uncommon. Herein, we report on 2 different cases which developed this association. Case 1 was a 59 year-old female who firstly complained of symptoms of cholestasis. The diagnosis of primary cholangitis was made on liver biopsy, and the endoscopic retrograde cholangiopancreatography (ERCP) showed narrowing and irregularity of the extra- and intrahepatic bile ducts. The results were positive for antiendomysial antibodies and the jejunal biopsy confirmed the coexistence of celiac disease, which was asymptomatic until that moment. The gluten-free diet ameliorated the index of cholestasis. Case 2 was an old man suffering from undiagnosed celiac disease for at least 5 years prior to admission at our Department. The diagnosis was based on the histological examination of a jejunal biopsy. The patient did not follow the gluten-free diet and was again admitted to our Department 6 years later with symptoms of cholestasis. The liver biopsy and ERCP confirmed the diagnosis of primary sclerosing cholangitis.


Assuntos
Doença Celíaca/epidemiologia , Colangite Esclerosante/epidemiologia , Adulto , Idoso , Ductos Biliares Extra-Hepáticos/diagnóstico por imagem , Ductos Biliares Extra-Hepáticos/patologia , Ductos Biliares Intra-Hepáticos/diagnóstico por imagem , Ductos Biliares Intra-Hepáticos/patologia , Doença Celíaca/diagnóstico por imagem , Doença Celíaca/patologia , Colangiopancreatografia Retrógrada Endoscópica , Colangite Esclerosante/diagnóstico por imagem , Colangite Esclerosante/patologia , Comorbidade , Duodeno/patologia , Feminino , Humanos , Mucosa Intestinal/patologia , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
11.
Minerva Gastroenterol Dietol ; 48(2): 203-6, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16489317

RESUMO

BACKGROUND: Endoscopic mucosal resection (EMR) of gastric superficial malignancies less than 20 mm in size and flat or slightly elevated without ulceration can be a definitive treatment, but its role in lesions of uncertain etiology or in which standard biopsies specimens fail to determine diagnosis is uncertain. EMR was performed in 7 patients previously diagnosed as having low grade dysplasia (Category 3 of Vienna classification) by standard biopsies on polypoid or flat gastric lesions. METHODS: After day spraying with 0.2% indigo carmine and injection of 20 ml saline with adrenaline 1/20000, EMR of flat or sessile polyps (size between 5 to 15 mm) was performed by the Cap and Suction technique (Inoue). RESULTS: In 3 patients a previous diagnosis of low grade dysplasia was changed into high grade dysplasia, in 1 patient adenocarcinoma was found at EMR histology. In 3 patients EMR confirmed diagnosis made with routine endoscopy biopsies and finally in 2 patients dysplasia was down-graded into intestinal metaplasia. CONCLUSIONS: EMR may be considered in diagnostic gastric lesions with low grade dysplasia at standard biopsies (Category 3 of Vienna Classification of gastrointestinal neoplasia).

12.
Minerva Gastroenterol Dietol ; 48(2): 159-64, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16489309

RESUMO

BACKGROUND: Infection with different genotypes of virulent Helicobacter pylori (Hp) strain, CagA and/or VacA positive, can play a role in the development of atrophic gastritis, duodenal ulcer (DU), and gastric carcinomas (GC). This study was undertaken to investigate if patients with GC with Hp negative histological Giemsa staining had a past infection by virulent strains of Hp CagA and/or VacA positive. METHODS: Twenty GC, (average age +/- SD) 68.14+/-9.8 years old, Hp negative to histological take part to the study. Two-control group were included: 19 Hp infected patients with DU eradicated 10 years before, 58+/-18.2 yrs. Hp negative status was determined every year with histology and follow-up after therapy was 120+/-32 months; range 96-144 months. Twenty asymptomatic children, 7+/-4.47 yrs, with Hp negative faecal test. The immunoblot assay was used to detect serum antibodies against CagA and VacA. RESULTS: Prevalence of CagA and VacA seropositivity was 90 and 95% in GC, 84 and 84% in DU Hp negative, 25 and 5% in children Hp negative, respectively. CagA and VacA antibody positivity was not significantly different between GC and patients with DU eradicated 10 years before. A true significant positivity was found against children (''t''-Student test; p<0.0001). Statistical difference was found in age between groups p<0.03. CONCLUSIONS: Patients with GC, although Hp negative at present, could be infected by Hp before the appearance of the disease as confirmed by CagA and VacA seropositivity. These data may reinforce the idea to consider Hp as a direct carcinogenetic agent of GC.

13.
Minerva Gastroenterol Dietol ; 48(2): 169-73, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16489311

RESUMO

BACKGROUND: To evaluate the utility of 2 biopsies of antrum and gastric body on routinary endoscopy for the assessment of type III intestinal metaplasia (IM-3) and Helicobacter pylori (Hp) status, 1750 patients (pts) (895 males and 855 females, mean age 60.2) were considered from June 1998 to June 2000. METHODS: Specimens were graded 0 to 3 for atrophy, IM-3 and Hp status. 620 pts treated previously with antibiotics or not eligible for biopsy were excluded from initial 2360 pts. RESULTS: IM-3 (score >0), was found in 118 pts (6.7%), 86 pts (4.9%) only in the antrum. Ten of 355 pts (2.8%) with normal endoscopy findings and 47 of 702 (6.6%) with non erosive endoscopic gastritis resulted IM-3 positive in the antrum. 709 pts (40.5%) were found positive for Hp in antrum or/and corpus. The presence of Hp and IM-3 in the antrum was not correlated (p=0.99; spearman test). A positive correlation (p=0.000) between duodenal ulcer and Hp was found when antral Hp positivity was taken into account. Gastric carcinoma risk index (GCRI) was found in 358 pts (20.4%); in this group 131 pts (36.6%) were Hp positive, 82 pts (23%) have IM-3, 184 pts (51.4%) have atrophy. CONCLUSIONS: The incidence of IM-3 is low (6.7%) in routinary endoscopy. Normal endoscopy does not exclude the presence of IM-3. The biopsy is necessary to discover IM-3 in the antrum in 5.3% of pts with normal or aspecific endoscopic gastritis. Application of the GCRI might be useful to identify a group of patients carrying a higher risk for gastric carcinoma.

14.
Minerva Gastroenterol Dietol ; 48(2): 175-8, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16489312

RESUMO

BACKGROUND: Chronic atrophic gastritis and intestinal metaplasia are regarded as predisposing factors for gastric cancer associated with Helicobacter pylori infection, and their severity appears to influence gastric cancer risk. Our purpose was to determine the outcome of chronic gastritis after H. pylori eradication in a long-term follow-up. METHODS: Fifty-four consecutive patients with duodenal ulcer and H. pylori infection were enrolled in the study. Endoscopic examination with antral and corporal biopsy was done at baseline and yearly after conventional eradication therapy (omeprazole 40 mg b.i.d., amoxocyllin 1 g b.i.d and clarithromycin 500 mg b.i.d.). Gastritis, atrophy, and metaplasia were graded according to the updated Sydney System. RESULTS: Twenty-four patients were successfully treated; infection persisted in 14 and 16 dropped out (during the first 5 years of follow-up). Inflammation and mean neutrophil activity significantly decreased in patients in whom H. pylori was eradicated. Glandular atrophy improved in 2 and disappeared in 5/17 patients, whereas intestinal metaplasia improved in 3 and disappeared in 2/12. In the patients in whom H. pylori persisted, inflammatory infiltrate, atrophy and intestinal metaplasia had not significantly decreased during follow-up. In contrast, glandular atrophy worsened in 2 and developed in 5/7 patients. Similarly, intestinal metaplasia did not improve when present and developed in 5/13 cases. CONCLUSIONS: In a long-term follow-up, H. pylori eradication does not affect glandular atrophy, but it seems to prevent the development of precancerous lesions such as intestinal metaplasia.

15.
Therapie ; 55(1): 143-6, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10860017

RESUMO

The existence of endogenous benzodiazepines such as diazepam and nordiazepam has been provided in human blood and brains as well as in medicinal plants and foods. It must be stressed, however, that in plasma and brain tissue there are also other benzodiazepine-like compounds termed 'endozepines' which are not halogenated. A synthetic pathway for the production of benzodiazepine-like compounds and endozepines has not yet been found, hence it may be surmised that these compounds could be of exogenous source. Changes in the level of endogenous circulating benzodiazepines due to food or drug ingestion could be responsible for pathological conditions. Clinical experiments were designed in order to study the levels of the endogenous benzodiazepines in vegetables and in the blood of control subjects and of cirrhotic patients. These patients accumulate benzodiazepines because of decreased liver metabolization capacity and impaired renal secretion, reaching plasma concentrations similar to those recorded in commercial benzodiazepine consumers.


Assuntos
Benzodiazepinas/farmacologia , Receptores de Superfície Celular/metabolismo , Receptores de GABA/fisiologia , Ácido gama-Aminobutírico/fisiologia , Anti-Inflamatórios não Esteroides , Antipirina , Benzodiazepinas/sangue , Análise de Alimentos , Humanos , Cirrose Hepática/metabolismo
17.
Metab Brain Dis ; 24(1): 81-93, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19082698

RESUMO

Benzodiazepines of natural origin (NBZDs) have been found in human blood and brains as well as in medicinal plants and foods. In plasma and brain tissue there are i.e. diazepam and nordiazepam equal to commercial drugs but there are also other benzodiazepine-like compounds termed "endozepines", which act as agonists at the benzodiazepine receptors of central type (CBR). A synthetic pathway for the production of NBZDs has not yet been found, but it has been suggested that micro-organisms may synthesize molecules with benzodiazepine-like structures. Hence NBZDs could be of both endogenous and exogenous source and be considered as natural anxyolitic and sedative. Interestingly there are also natural compounds, such as the polypeptide Diazepam Binding Inhibitor (DBI) acting as an "inversive agonist" implicated in fair and panic disorders. It has been suggested that NBZDs may play a role in the pathogenesis of hepatic encephalopathy (HE). Multidirectional studies evaluated NBZDs levels (1) in the blood of normal subjects, of cirrhotic with or without HE and in commercial benzodiazepine consumers; (2) in the blood of cirrhotic treated or not with a non-absorbable antibiotic; (3) in several constituents of our diet. In conclusion, NBZDs increase sometime in cirrhotics with or without HE but they reach concentrations not higher than those found in commercial benzodiazepines consumers. Hence NBZDs must be considered as occasional precipitating factor of HE and benzodiazepine antagonists only symptomatic drugs. The finding that NBZDs may be in part synthesized by intestinal bacterial flora and in part constituent of our diet underlines the importance to feed cirrhotic patients with selected food.


Assuntos
Encéfalo/metabolismo , Encéfalo/fisiopatologia , Inibidor da Ligação a Diazepam/metabolismo , Encefalopatia Hepática/metabolismo , Encefalopatia Hepática/fisiopatologia , Receptores de GABA-A/metabolismo , Animais , Ansiolíticos/metabolismo , Bactérias/química , Bactérias/metabolismo , Alimentos Formulados/normas , Antagonistas de Receptores de GABA-A , Humanos , Ligantes , Extratos Vegetais/metabolismo , Extratos Vegetais/farmacologia
18.
Acta Ophthalmol Scand ; 75(1): 41-3, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9088399

RESUMO

Vitreous fluorophotometry was used to investigate the effect of Bendazac lysine on the blood retinal barrier in 12 insulin-dependent diabetics with mild background retinopathy. The study was a randomized, double blind, cross-over trial, drug versus Placebo. Each treatment period was of 4 months. The vitreous penetration coefficient was reduced by 21% (95% c.i. 12, 30; p = 0.001) by treatment with respect to Placebo.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Barreira Hematorretiniana/efeitos dos fármacos , Permeabilidade da Membrana Celular , Fluorofotometria , Indazóis/uso terapêutico , Corpo Vítreo/metabolismo , Adulto , Barreira Hematorretiniana/fisiologia , Estudos Cross-Over , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Método Duplo-Cego , Feminino , Fluoresceína , Fluoresceínas/administração & dosagem , Corantes Fluorescentes/administração & dosagem , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho da Amostra , Corpo Vítreo/efeitos dos fármacos
19.
Pharmacol Res ; 32(1-2): 57-61, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8668648

RESUMO

Polyamine concentrations including putrescine, spermidine and spermine were documented in two brain areas of rats with mild and severe stages of hepatic encephalopathy (HE) due to fulminant hepatic failure induced by galactosamine HC1 injection (3 g kg-1 i.p.). In the mild stage of HE putrescine increased by 3-4 times whereas spermidine and spermine showed a slight increase. The scenario, however, was found to be changed going from the mild to the severe stage of HE, since in this last stage spermidine and spermine showed a further rise while putrescine was found to be significantly lower than in the mild stage of HE in both the brain areas studied. The changes in the ratio among the three polyamines with an enhanced prevalence in the severe stage of HE of spermidine and spermine are likely to be related to the exhaustion of the synthetic pathway of putrescine or to a reduction of the interconversion to this polyamine from spermidine and spermine. Considering that these last two polyamines potentiate the N-methyl-D-aspartate glutamate receptor mediated toxicity and that they might exert neurotoxic effects per se, there are clear reasons for suspecting an implication of the described changes of polyamines in the neurochemical mechanism which sustain HE and to surmise a potential therapeutic effect in this pathology of non-competitive antagonists of polyamine-site on N-methyl-D-aspartate glutamate receptors.


Assuntos
Galactosamina/efeitos adversos , Encefalopatia Hepática/metabolismo , Poliaminas/metabolismo , Animais , Lobo Frontal/química , Encefalopatia Hepática/induzido quimicamente , Hipocampo/química , Putrescina/metabolismo , Ratos , Ratos Sprague-Dawley , Espermidina/metabolismo , Espermina/metabolismo
20.
Ital J Gastroenterol Hepatol ; 31(1): 61-5, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10091105

RESUMO

BACKGROUND: Although the role of cholesterol in tumourigenesis is unclear, it is used by the tumoural cells for biosynthetic processes and for steroid synthesis. AIM: To accertain whether plasma cholesterol levels might be a reliable neoplastic marker of a developing hepatocellular carcinoma in patients with liver cirrhosis. PATIENTS: Plasma cholesterol has been studied in 287 liver cirrhosis patients without hepatocellular carcinoma and in 132 patients with hepatocellular carcinoma. RESULTS: Cholesterol (mean +/- SEM) was higher in hepatocellular carcinoma patients when compared with age-, sex- and Child-Pugh class matched cirrhotic controls. In Child-Pugh class A, B and C with uncomplicated liver cirrhosis these values were, respectively, 142.0 +/- 2.5, 117.3 +/- 2.5, 97.4 +/- 2.9 vs 172.5 +/- 4.7, 163.8 +/- 7.9, 153.5 +/- 8.0 +/- mg/dl in patients with hepatocellular carcinoma (p < 0.001). A significant increase of cholesterol (p < 0.001) has been reported in the patients with liver cirrhosis when complicated by hepatocellular carcinoma and it was not related to cholestasis. CONCLUSIONS: This observation seems to suggest that the enhanced cholesterol biosynthesis by tumoural cells leads to a rise in plasma cholesterol of patients with cancer, and, moreover, that, this increase may be used as a neoplastic marker indicating the development of a tumour in patients with liver cirrhosis.


Assuntos
Biomarcadores Tumorais/sangue , Carcinoma Hepatocelular/sangue , Colesterol/sangue , Cirrose Hepática/sangue , Neoplasias Hepáticas/sangue , Biópsia , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/patologia , Colorimetria , Progressão da Doença , Feminino , Seguimentos , Humanos , Cirrose Hepática/complicações , Cirrose Hepática/patologia , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Fatores de Risco
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