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1.
Ann Phys Rehabil Med ; 53(2): 96-104, 2010 Mar.
Artículo en Inglés, Francés | MEDLINE | ID: mdl-20149778

RESUMEN

PURPOSES: To determine how many patients in a permanent vegetative state or a minimally conscious state are living in healthcare institutions in the Maine-et-Loire county of western France. To evaluate patient management, physical complications, problems encountered by nursing staff and the patient care teams' wishes. PATIENTS AND METHODS: We performed a cross-sectional, descriptive study in physical medicine and rehabilitation departments, nursing homes, geriatric units and local hospitals. All patients and their medical records were examined by the same investigator. A questionnaire for carers was used to evaluate nursing tasks and a second questionnaire for head nurses served to assess staff needs and the patient care teams' wishes. RESULTS: Thirteen patients were identified. Four were in a permanent vegetative state and nine were in a minimally conscious state. Ten patients were cared for in geriatric units, one in a physical medicine and rehabilitation department and two in local hospitals. All patients displayed limited joint angle ranges. All the patient care teams reported practical difficulties and ethical issues. DISCUSSION: Our survey highlighted the variety of care scenarios for patients in a permanent vegetative state or a minimally conscious state. It revealed practical difficulties and, above all, ethical questions. The present work could serve as a basis for implementation of a recently issued French government circular on defining specific wards for these patients.


Asunto(s)
Estado Vegetativo Persistente/epidemiología , Adulto , Directivas Anticipadas , Anciano , Cuidadores , Manejo de Caso/ética , Manejo de Caso/organización & administración , Manejo de Caso/estadística & datos numéricos , Estudios Transversales , Nutrición Enteral , Femenino , Francia/epidemiología , Necesidades y Demandas de Servicios de Salud , Servicios de Salud para Ancianos/estadística & datos numéricos , Unidades Hospitalarias/estadística & datos numéricos , Humanos , Cuidados a Largo Plazo/ética , Cuidados a Largo Plazo/métodos , Cuidados a Largo Plazo/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Espasticidad Muscular/etiología , Espasticidad Muscular/rehabilitación , Supervisión de Enfermería , Planificación de Atención al Paciente , Grupo de Atención al Paciente , Estado Vegetativo Persistente/enfermería , Estado Vegetativo Persistente/rehabilitación , Estado Vegetativo Persistente/terapia , Índice de Severidad de la Enfermedad , Instituciones de Cuidados Especializados de Enfermería/estadística & datos numéricos , Encuestas y Cuestionarios , Traqueostomía
2.
Br J Dermatol ; 145(5): 749-57, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11736898

RESUMEN

BACKGROUND: The skin is the major interface between the body and its environment. Directly and continuously exposed to a large variety of foreign agents and stimuli such as ultraviolet radiation (UVR), cutaneous cells are active sites of intense metabolism. The cytochromes P450 (P450) are a group of enzymes that play an important part in the protective role of the skin; they are a family of microsomal membrane-bound mono-oxygenases. These haem-containing proteins catalyse the insertion of an atom of molecular oxygen into the substrate. Although generally present at low levels, a certain number of these enzymes have now been characterized in mammalian skin as constitutive or inducible isoforms. OBJECTIVES: To test the effects of UVR, a source of oxidative stress, on the expression of mRNA coding for several P450 isoforms (CYP), with particular reference to the CYP2E1 and CYP4A11 isoforms, which might play a role in lipid metabolism in human keratinocytes. METHODS: Human keratinocytes were cultured, irradiated and mRNA expression was analysed by gel electrophoresis after reverse transcriptase polymerase chain reactions. CYP proteins were determined from keratinocyte microsomal fractions by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and immunoperoxidase staining. Thin layer chromatography was used to detect (omega-1)- and (omega)-hydroxylation of lauric acid in the microsomal fractions. RESULTS: mRNAs for CYP2E1, CYP1A1 and CYP3A5 were expressed in all the keratinocyte preparations tested; however, neither CYP3A4 nor CYP3A7 were detected, either in the presence or absence of UVR treatment. CYP19Aro, CYP2C19 and CYP26 were not expressed constitutively, although some induction of CYP19Aro was seen after combined UVB and UVA irradiation. CYP4A11 mRNA was not detected in any keratinocyte preparations either under control conditions or after UVB treatment. Nevertheless, in non-irradiated keratinocyte microsomes, two protein bands were immunoreactive with anti-CYP4A11 enzyme antibodies, one of which corresponds to CYP4A11 protein. UVA treatment of cultured keratinocytes induced CYP4A11 mRNA expression after 24 h, as well as an increase in immunoreactivity of the two protein bands. Although (omega-1)- and (omega)-hydroxylation of fatty acids is attributed to CYP2E1 and CYP4A11, respectively, in the liver or kidney, no omega-hydroxylation of lauric acid was observed in microsomal preparations from cultured keratinocytes. CONCLUSIONS: However, CYP4A11 may participate in the defence mechanism against UVA-induced oxidative damage.


Asunto(s)
Sistema Enzimático del Citocromo P-450/metabolismo , Queratinocitos/metabolismo , Queratinocitos/efectos de la radiación , Oxigenasas de Función Mixta/metabolismo , Rayos Ultravioleta , Técnicas de Cultivo de Célula , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP4A , Sistema Enzimático del Citocromo P-450/genética , Electroforesis en Gel de Poliacrilamida , Expresión Génica/efectos de la radiación , Humanos , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Microsomas/metabolismo , Oxigenasas de Función Mixta/genética , ARN Mensajero/genética
3.
Pigment Cell Res ; 13(3): 165-71, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10885675

RESUMEN

The effects of calcium D-pantetheine-S-sulfonate (PaSSO3Ca) on human pigmentation were examined by in vitro assays using two types of human melanocytes: normal adult melanocytes (HNM) and M4Be melanoma cells. The compound, when added to a culture medium at doses indicating no cytotoxicity, causes a visually recognizable, reversible loss of pigment in both types of cells. Determination of melanin content, incorporation of 14C-DOPA into melanins and tyrosinase activities demonstrated that treatment of these cells with PaSSO3Ca resulted in a marked decrease in all three areas. When homogenates of these cells were assayed with lectins, the glycosylation pattern was modified, as tyrosinase activities were reduced in the cells treated with the compound. Immunoprecipitation of tyrosinase and tyrosinase-related protein 1 (Tyrp1 or TRP1) in cells incubated with radioactive glucosamine disclosed that glucosamine uptake by these enzymes was apparently increased, suggesting structural alterations in their sugar moieties. It is also noted that PaSSO3Ca is analogous in its chemical structure to Coenzyme A (CoA), which plays an important role in the intracellular transport of proteins. Based on these findings, it is likely that the compound exerts its depigmenting effects in human pigment cells through the modification of glycosylation of tyrosinase and TRP1, which are key enzymes for melanogenesis.


Asunto(s)
Melanocitos/efectos de los fármacos , Glicoproteínas de Membrana , Oxidorreductasas , Panteteína/análogos & derivados , Panteteína/farmacología , Pigmentación/efectos de los fármacos , Western Blotting , Coenzima A/metabolismo , Dihidroxifenilalanina/metabolismo , Glicosilación , Humanos , Immunoblotting , Melaninas/metabolismo , Melanocitos/metabolismo , Melanoma/tratamiento farmacológico , Melanoma/metabolismo , Monofenol Monooxigenasa/metabolismo , Proteínas/metabolismo , Células Tumorales Cultivadas/efectos de los fármacos
4.
Cell Mol Biol (Noisy-le-grand) ; 45(8): 1183-9, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10643967

RESUMEN

Activation of the Na+/H+ exchanger is associated with cell growth and differentiation. Our study has tested whether somatostatin-14 (SS-14), which is a potent inhibitor of liver regeneration, has an inhibitory effect on the Na+/H+ exchange (NHE-1) of rat hepatocytes. We treated hepatocytes with SS-14 prior and after cell culture. NHE-1 activity of short term cultured hepatocytes was estimated with the recovery rate of pHi after 9 min. acid-loading in a sodium free buffer. Cultured with SS-14 (100 nM) inhibited significantly the pHi recovery rate of hepatocytes, dpHi/dt and set point were significantly decreased in the presence of SS-14 in comparison to controls. The resting pHi of hepatocytes was not affected in the presence of SS-14. In contrast, addition of SS-14 after cell culture had no effect on the pHi recovery rate of hepatocytes. Therefore the inhibitory action of SS-14 on NHE-1 activity of rat hepatocytes appears to depend on the presence of the hormone in the early steps of the process of cell growth/adhesion. Inhibition of SS-14 on NHE-1 activity seems to mediate, at least in part, its inhibition on liver regeneration.


Asunto(s)
Intercambiadores de Sodio-Hidrógeno/metabolismo , Somatostatina/metabolismo , Animales , Adhesión Celular/fisiología , Células Cultivadas , Hígado/citología , Hígado/metabolismo , Ratas , Somatostatina/farmacología
5.
J Invest Dermatol ; 111(3): 472-7, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9740243

RESUMEN

Although the induction of pigmentation following exposure of melanocytes to ultraviolet light in vivo and in vitro is well documented, the intracellular mechanisms involved in this response are not yet fully understood. Exposure to UV-B radiation leads to the production of DNA damage, mainly cyclobutane pyrimidine dimers, and it was recently suggested that the thymidine dinucleotide pTpT, mimicking small DNA fragments released in the course of excision repair mechanisms, could trigger melanin synthesis. We now report that the thymidine dinucleotide pTpT induces melanogenesis both in human normal adult melanocytes and in human melanoma cells. Thus, the SOS-like response suggested by Gilchrest's work to be evolutionary conserved, based primarily on work in murine cells and guinea pigs, is also apparently present in the human. Thymidine dinucleotide is nontoxic to melanoma cells and does not induce apoptosis in these cells, but induces S phase cell cycle arrest and a proliferation slow down. Because thymidine excess in culture medium leads to the synchronization of cells in S phase, we investigated whether this phenomenon was involved in the increase in melanin synthesis. We show that melanin synthesis is specifically triggered by the dimeric form of the thymidine and not by the monomeric form pT. Thus, our data strongly support that thymidine dinucleotides pTpT mimic at least part of the effects of ultraviolet irradiation, and may hence represent an invaluable model in the study of the molecular events involved in melanogenesis induction triggered through DNA damage.


Asunto(s)
Melaninas/biosíntesis , Melanocitos/efectos de los fármacos , Oligonucleótidos/farmacología , Fase S/efectos de los fármacos , Timidina/farmacología , División Celular/efectos de los fármacos , Fragmentación del ADN , Humanos , Melanocitos/metabolismo , Células Tumorales Cultivadas
7.
J Hepatol ; 26(6): 1281-6, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9210615

RESUMEN

BACKGROUND/AIMS: Electroneutral absorption of NaCl by the gallbladder mucosa is likely to depend at least in part on a Na+/H+ exchanger. In intestine and colon, absorption due to Na+/H+ exchanger is explained by the presence of specific isoforms of the exchanger, the NHE-3 isoform and possibly the NHE-2 isoform. The aim of the present work was to determine whether the mRNAs coding for NHE-2 and NHE-3 are expressed in epithelial cells of human gallbladder. METHODS: Total RNAs from human gallbladder were subjected to reverse transcription-polymerase chain reaction using specific primers. No message was observed with NHE-2 specific primers, showing that NHE-2 isoform plays no role in gallbladder absorption. With NHE-3 specific primers, a 239 bp cDNA fragment was obtained and showed a high homology with the NHE-3 isoform, confirming the presence of NHE-3 in the gallbladder wall. This fragment was cloned in a pLitmus vector in order to produce cRNA probes by in vitro transcription. Cellular localization of the NHE-3 mRNA was studied on cryostat sections using the cRNA probes labeled with Digoxigenin-11-UTP, controls included assays with sense probe, antibodies without probe and RNaseA treated tissue. A specific staining of the NHE-3 mRNAs was found to be strictly localized to the gallbladder epithelial cells. RESULTS/CONCLUSIONS: Expression of NHE-3 in the gallbladder was found only in the absorptive epithelial cells. The NHE-3 isoform of the Na+/H+ exchanger is likely to be involved in water and electrolyte absorption from bile.


Asunto(s)
Vesícula Biliar/metabolismo , Intercambiadores de Sodio-Hidrógeno/biosíntesis , Secuencia de Bases , Cartilla de ADN , ADN Complementario , Epitelio/metabolismo , Humanos , Hibridación in Situ , Datos de Secuencia Molecular , Membrana Mucosa/metabolismo , Reacción en Cadena de la Polimerasa , ARN Mensajero/biosíntesis , Homología de Secuencia de Ácido Nucleico , Intercambiador 3 de Sodio-Hidrógeno , Intercambiadores de Sodio-Hidrógeno/genética , Transcripción Genética
8.
Pflugers Arch ; 432(5): 791-6, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8772128

RESUMEN

The absorption of water and electrolytes by the gallbladder seems to be largely dependent upon a Na+/H+ exchange at the apical membrane of the gallbladder epithelium. To find out if the exchanger involved is the NHE3 isoform, as in other absorbing epithelia, two studies were performed using the rabbit gallbladder. First, we studied 22Na absorption in Ussing chambers with Krebs buffer as a control solution, and in the presence of amiloride (100, 200 or 1000 microM), ethyl-isopropyl-amiloride (EIPA, 1 or 5 microM), or the phorbol ester, phorbol 12-myristate 13-acetate (PMA, 1 microM). A net mucosal-to-serosal Na+ flux was observed with control buffer. No inhibition of this net flux was observed with 5 microM EIPA, and the IC50 for amiloride was found to be 200 microM. PMA induced a reduction of absorption by 30% that was prevented by incubation with calphostin C. Resistance to amiloride and EIPA, and inhibition by PMA are consistent with the involvement of the NHE3 isoform. The second study involved reverse-transcriptase polymerase chain reaction (RT-PCR) of total gallbladder RNA, with two primers designed to amplify a 645-base-pair fragment from NHE3 mRNA. A cDNA fragment of the expected size was actually obtained from gallbladder RNA, while RT-PCR of RNA from the liver, which does not contain NHE3, gave negative results. A sequence of 492 nucleotides of the amplified product was determined, which was almost superimposable onto the known sequence of the corresponding fragment of rabbit NHE3. It is concluded that, in rabbit gallbladder, neutral NaCl absorption is, at least in part, dependent on the NHE3 isoform of the Na+/H+ exchanger.


Asunto(s)
Vesícula Biliar/metabolismo , Intercambiadores de Sodio-Hidrógeno/fisiología , Sodio/metabolismo , Absorción , Amilorida/farmacología , Animales , Secuencia de Bases , Agua Corporal/metabolismo , ADN Complementario/metabolismo , Electroforesis en Gel de Agar , Inhibidores Enzimáticos/farmacología , Datos de Secuencia Molecular , Naftalenos/farmacología , Reacción en Cadena de la Polimerasa , ARN Mensajero/metabolismo , Conejos , Intercambiadores de Sodio-Hidrógeno/genética , Acetato de Tetradecanoilforbol/farmacología
9.
Clin Sci (Lond) ; 91(2): 209-12, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8795445

RESUMEN

1. In man and in various animal species, absorption of NaCl from bile by the gallbladder mucosa is associated with luminal proton secretion. A similar absorption of NaCl in small intestine, colon and renal tubule is related, at least in part, to the presence of the NHE3 isoform of the Na+/H+ exchanger. This work was designed to find out whether NHE3 is also present in human gallbladder. 2. At surgery, 100-200 mg of the gallbladder wall was obtained from patients treated by cholecystectomy for gallstones. After isolation of the mucosa, total RNA was extracted and submitted to reverse transcription-polymerase chain reaction with two primers: 5'-AAGCCICTGGTGCAGTGGCTGAAGG-3' and 5'-GGAGTCCTTIAAGTCGGCIAAGCTGGGC-3', designed to amplify a sequence of 645 bp of rabbit NHE3 mRNA (642 bp in man). RNA from human liver and from rabbit heart, neither of which contain NHE3, and human ileal RNA, which does contain NHE3, were used as controls. 3. RNA extracted from the mucosal moiety of the gallbladder wall gave an amplification product of about 645 nucleotides. Controls gave the expected negative or positive results. Sequencing of the amplified RNA showed it was almost identical to previously determined sequences of NHE3 in other human tissues. 4. It is concluded that the mucosa of human gallbladder contains the mRNA of NHE3 isoform. This isoform could therefore play a role in sodium absorption from bile.


Asunto(s)
Vesícula Biliar/química , ARN Mensajero/análisis , Intercambiadores de Sodio-Hidrógeno/análisis , Animales , Secuencia de Bases , Cartilla de ADN/genética , ADN Circular/genética , Electroforesis en Gel de Agar , Humanos , Íleon , Mucosa Intestinal/química , Datos de Secuencia Molecular , Membrana Mucosa/química , Reacción en Cadena de la Polimerasa , Conejos , Intercambiadores de Sodio-Hidrógeno/genética
10.
Dig Dis Sci ; 40(11): 2336-40, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7587811

RESUMEN

The finding of a high PCO2 in basally secreted pancreatic juice of man and dog raises the hypothesis of proton secretion from ductal epithelial cells presumably through a Na+/H+ exchanger. To test this possibility, H+ luminal secretion and Na+ movements were measured in vitro on samples of bovine pancreatic ducts mounted in Ussing-type chambers. The rate of luminal acidification measured by the pH stat method, using bicarbonate-free media gassed with 100% O2, reached 2.75 muEq/cm2/hr. Proton secretion was blocked in the presence of 1 nM amiloride or in the absence of Na+ (replaced by choline) in the mucosal solution. Study of transepithelial 22Na fluxes in short-circuited tissue, bathed on both sides by control Ringer solution, gassed by 95% O2-5% CO2 demonstrated a net sodium transport from the mucosal to the interstitial side of the duct (net 22Na flux = 3.23 +/- 0.8 muEq/cm2/hr). This net sodium transport was electroneutral and blocked by mucosal amiloride (0.5-1 mM/liter) or by interstitial ouabain (1 mM/liter). These results are consistent with the existence of a Na+/H+ exchanger on the luminal side of the bovine main pancreatic duct.


Asunto(s)
Conductos Pancreáticos/metabolismo , Intercambiadores de Sodio-Hidrógeno/metabolismo , Amilorida/farmacología , Animales , Bovinos , Técnicas In Vitro , Nistatina/farmacología , Ouabaína/farmacología , Sodio/metabolismo , Intercambiadores de Sodio-Hidrógeno/antagonistas & inhibidores
11.
Contracept Fertil Sex ; 23(7-8): 457-9, 1995.
Artículo en Francés | MEDLINE | ID: mdl-7550559

RESUMEN

A new solution intended for use in feminine hygiene, and composed of a lactic acid base and of lactoserum at pH 5.2, was tested for a period of 8 weeks on 40 women. This test focused on its influence on the pH and the flora, as well as on the tolerance of the mucous membrane. Successive measurements of the vulvar and vaginal pH revealed no statistically significant variation between the beginning and the end of the trial. At the study inclusion thirty patients had a normal flora; of these, twenty-eight showed no change during the eight weeks of the trial. A candidiasis appeared in two patients in the middle of the trial; one of these patients received no treatment, while the other was given a five-day treatment due to similar occurrences in her past medical history. The product under study was continued throughout the trial, at the conclusion of which the flora was found to have returned to normal. At the study inclusion ten patients had either a candidiasis or a vaginitis. Their lack of symptoms and the absence of any previous problems resulted in no treatment being made in five of the ten cases, while in four cases the presence of such prior problems led to the immediate carrying out of short-length treatments. In every case, the product under study was used until the end of the trial. Bacteriological studies showed that in all the patients--whether or not they had been treated--the flora rapidly returned to normal.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Higiene , Sueros Inmunes , Lactatos/administración & dosificación , Ácido Láctico , Jabones/administración & dosificación , Vagina/efectos de los fármacos , Administración Intravaginal , Adulto , Candidiasis Vulvovaginal/inducido químicamente , Combinación de Medicamentos , Emulsiones , Femenino , Humanos , Concentración de Iones de Hidrógeno , Lactatos/efectos adversos , Persona de Mediana Edad , Vagina/microbiología
12.
J Lab Clin Med ; 123(4): 565-73, 1994 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8145005

RESUMEN

Calcium concentration of pancreatic juice depends on secretion of calcium bound to enzymatic proteins or calcium diffusion from interstitial fluids. To evaluate the relative magnitude of these pathways, we studied the influence of hypercalcemia on ionized calcium (Ca++) in dog pancreatic juice. Pancreatic juice was collected during basal secretion and during stimulation by secretin or secretin plus caerulein in control conditions and under CaCl2 infusion. [Ca++] was measured by selective electrodes. Saturation of juice in CaCO3 was calculated. In stimulated juice, total calcium concentration ([CaT]) and [Ca++] were unchanged by hypercalcemia. In basal juice, composition was profoundly modified by hypercalcemia because [CaT] (3.31 +/- 0.89 mmol/L vs 1.80 +/- 0.44 for controls), [Ca++] (1.44 +/- 0.37 mmol/L vs 0.84 +/- 0.24 mmol/L for controls), and the index of saturation in CaCO3 (5.2 +/- 2.4 vs 2.9 +/- 1.8 for controls) increased significantly. Protein concentration was unchanged. This suggests that in basal conditions, the relationship between plasma and juice calcium levels is due to passive interstitial Ca++ diffusion through the pancreatic ducts. In accordance with the hypothesis of a restricted calcium diffusion, the effects of hypercalcemia were flow rate dependent, being less pronounced when basal flow rate increased. It is concluded that, in the dog, the calcium species found in stimulated juice result from a redistribution of calcium secreted along with proteins, whereas at low secretion rate, juice calcium level depends mainly on interstitial Ca++ diffusion into the main pancreatic ducts.


Asunto(s)
Calcio/metabolismo , Hipercalcemia/metabolismo , Jugo Pancreático/metabolismo , Análisis de Varianza , Animales , Cationes Bivalentes/metabolismo , Ceruletida , Perros , Eritritol/metabolismo , Espacio Extracelular/metabolismo , Secretina
13.
Dig Dis Sci ; 38(11): 2090-7, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8223086

RESUMEN

In several species, bicarbonate and calcium concentrations of pancreatic juice are known to vary during the different phases of pancreatic secretion. The effects of these variations on the saturation of juice with calcium carbonate, a critical factor for the formation of pancreatic stones, are not known. In this work, we studied the saturation degree of pancreatic juice with calcium carbonate in six unanesthetized beagle dogs equipped with Thomas cannulae during basal secretion and after bolus injections of cerulein (30 ng/kg) or secretin (0.25 units/kg). In the different samples of pure pancreatic juice, pH, PCO2, bicarbonate, and proteins were measured by standard methods. Total calcium (CaT) and ionized calcium (Ca2+) were determined using calcium-specific electrodes. Saturation with calcium carbonate was calculated by reference to the solubility product of calcite at 37 degrees C. Almost all the samples were found to be supersaturated with calcium carbonate but large variations of the saturation index were observed. In basal samples, obtained during periods of low secretion rate, the mean saturation index (3.35 +/- 3.01) was significantly lower than under secretion (12.10 +/- 5.14) or cerulein (18.01 +/- 8.42). This low basal saturation index, in spite of a high Ca2+ content, was explained by a low bicarbonate concentration (37.6 +/- 18.9 mmol/liter) and a high PCO2 (13.4 +/- 7.5 kPa). In contrast, in juice obtained after hormonal stimulation, PCO2 (4.8 +/- 1.6 kPa) was similar to plasma PCO2 (5.5 +/- 1.2 kPa).(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Carbonato de Calcio/metabolismo , Cálculos/etiología , Enfermedades Pancreáticas/etiología , Conductos Pancreáticos/metabolismo , Jugo Pancreático/química , Animales , Cálculos/química , Ceruletida/farmacología , Perros , Enfermedades Pancreáticas/metabolismo , Jugo Pancreático/metabolismo , Secretina/farmacología , Factores de Tiempo
14.
Hepatology ; 11(6): 997-1002, 1990 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2365297

RESUMEN

Samples of gallbladder bile obtained from 25 controls and 34 patients with pigment (28 cases) or cholesterol (6 cases) gallstones were studied to establish whether disturbances in regulation of the biliary pH are likely to play a role in the pathogenesis of gallstones. Samples were assayed for pH, PCO2 and concentrations of sodium, bicarbonate and calcium (total and ionized). Saturation of bile in calcium carbonate was calculated. The main results of the study were as follows: (a) mean (+/- S.D.) PCO2 was significantly higher in gallbladder bile (6.72 +/- 0.36 kPa (in controls) and 7.63 +/- 0.29 kPa in patients) than in blood. This is consonant with previous results in animal species; it suggests that also in man a mucosal Na+ H+ antiport acidifies the gallbladder bile generating CO2 from biliary bicarbonate. (b) Biliary pH decreased when sodium concentration increased over a range of 140 to 280 mM. The pH decreased slightly when sodium increased from 140 to 200 mM and rapidly beyond this value; the rapid pH decrease in concentrated bile was associated with bicarbonate concentrations lower than 1 to 2 mM. The results showed that bicarbonate is the main buffer of gallbladder bile. (c) The pH decrease during bile concentration was similar in patients and controls. In both groups, fully concentrated bile was unsaturated in calcium carbonate. The results suggest that gallstone formation is not due to disturbances of biliary pH regulation. However, the normal concentration process that increases Ca++ concentration up to 4 mM and lowers pH values is likely to favor, in fully concentrated biles, the precipitation of calcium salts such as calcium bilirubinate.


Asunto(s)
Bilis/metabolismo , Colelitiasis/metabolismo , Vesícula Biliar/metabolismo , Bicarbonatos/metabolismo , Calcio/metabolismo , Carbonato de Calcio/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Concentración Osmolar , Valores de Referencia
15.
Gastroenterology ; 96(3): 881-4, 1989 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2914648

RESUMEN

Saturation with calcium carbonate was measured in human pancreatic juice anaerobically collected for diagnostic purposes in 15 patients who were ultimately found not to have pancreatic disease. Bicarbonate, PCO2, proteins, and total and ionized calcium were measured in samples collected every minute during a 20-min period after intravenous administration of secretin (1 U/kg) and, 10 min later, caerulein (75 ng/kg). All samples were supersaturated with calcium carbonate. The first sample (washing-out sample) contained the highest concentrations of ionized calcium (Ca2+) and proteins but was least supersaturated with calcium carbonate. Washing-out samples also differed significantly from samples under caerulein by having a lower pH (7.52 +/- 0.30) and higher PCO2 (103.1 +/- 32.20 mmHg) versus 8.22 +/- 0.15 and 38.4 +/- 4.5 mmHg, respectively. Values of PCO2 increased and bicarbonate concentration decreased linearly with protein concentration in washing-out samples but not under hormonal stimulation. This suggests that a concentration of pancreatic juice occurs in pancreatic ducts in association with luminal H+ secretion and CO2 formation, which results from bicarbonate neutralization. During stimulation, ionized calcium concentration increased with protein concentration without any change of PCO2, so that supersaturation was more pronounced under caerulein than under secretin stimulation. Disturbances of the ductal concentration of pancreatic juice during interdigestive periods could be important for pancreatic stone formation in humans.


Asunto(s)
Carbonato de Calcio/análisis , Jugo Pancreático/análisis , Bicarbonatos/análisis , Ceruletida , Femenino , Humanos , Concentración de Iones de Hidrógeno , Masculino , Persona de Mediana Edad , Conductos Pancreáticos/metabolismo , Secretina , Estimulación Química
16.
J Hepatol ; 7(1): 57-62, 1988 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-3183351

RESUMEN

To establish whether the calcium-binding capacities of the bile salts play an essential role in their stimulatory effects on biliary calcium secretion, we compared (1) the effects of tauro- and glycoconjugates of ursodeoxycholate (TUDC-GUDC) and cholate (TC-GC) on biliary calcium in bile fistula rats, and (2) the in vitro calcium-binding capacities of mixed micelles containing the same bile salts. The increase of biliary calcium depended on the infused bile salt in the following order: GUDC greater than GC = TUDC greater than GC). The same order was obtained in vitro, so that there was a linear relationship between the slopes of the [Ca] vs. [bile salts] regression lines in vivo and the binding percentages of the four bile salts. Biliary ionized calcium concentration was almost independent of bile salt concentration. However, hepatic bile was supersaturated with calcium carbonate in the presence of the four bile salts. Our results suggest that biliary calcium concentration increases in relation to the calcium-binding capacity of the various bile acids so that ionized biliary calcium remains in equilibrium with plasma. As a result, bile saturation with calcium is almost completely independent of bile salt secretion.


Asunto(s)
Ácidos y Sales Biliares/farmacología , Bilis/metabolismo , Carbonato de Calcio/metabolismo , Calcio/metabolismo , Animales , Ácido Glicocólico/farmacología , Masculino , Ratas , Ratas Endogámicas , Ácido Tauroquenodesoxicólico/farmacología , Ácido Taurocólico/farmacología , Ácido Ursodesoxicólico/análogos & derivados , Ácido Ursodesoxicólico/farmacología
17.
Life Sci ; 42(5): 533-8, 1988.
Artículo en Inglés | MEDLINE | ID: mdl-3339946

RESUMEN

By using a specific collagenase preparation preserving lipolytic enzymes, we could isolate intact rat liver cells with monoester lipase (MEL) and, for the first time, substantial amounts of endogenous neutral triester lipase (TEL) activities assayable as cell-bound enzymes. TEL and MEL activities were found exclusively in parenchymal cells. Virtually all TEL was located on plasma membrane from which it was rapidly released at 37 degrees C in the absence of any additive. MEL was distributed almost equally inside the cell and in the membrane, to which it was firmly attached. Infusion of heparin to the whole animal before liver exposure decreased by 80% the TEL content of parenchymal cells (a property typical of hepatic lipase) whilst MEL was unchanged. These results question the concept that heparin-releasable hepatic lipase acts at the surface of endothelial liver cells and further suggest that TEL and MEL refer to distinct catalytic entities.


Asunto(s)
Lipasa/metabolismo , Lipólisis , Hígado/enzimología , Animales , Membrana Celular/enzimología , Separación Celular , Heparina/farmacología , Hígado/citología , Hígado/efectos de los fármacos , Masculino , Ratas , Ratas Endogámicas
18.
Anal Biochem ; 154(1): 26-8, 1986 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-3010771

RESUMEN

The heparin-releasable neutral lipase (EC 3.1.1.3) from rat liver is inactivated by the common preparations of collagenases (EC 3.4.24.3) used for the isolation of liver cells. We show that two collagenases purified from Clostridium histolyticum allow both the complete preservation of this lipolytic activity and a good viability of liver cells isolated by the usual perfusion protocol.


Asunto(s)
Fraccionamiento Celular/métodos , Lipasa/metabolismo , Hígado/enzimología , Colagenasa Microbiana , Animales , Clostridium/enzimología , Lipasa/antagonistas & inhibidores , Hígado/citología , Masculino , Colagenasa Microbiana/aislamiento & purificación , Colagenasa Microbiana/farmacología , Ratas , Ratas Endogámicas
19.
Hepatology ; 5(6): 1209-12, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-2998964

RESUMEN

The potential role of bile salts in preventing calcium carbonate precipitation was investigated by studying their interaction of Ca2+ and their inhibitory effects on calcium carbonate formation. Glycochenodeoxycholate micelles bound more calcium than did glycocholate. At bile salt concentrations exceeding 12.5 mM, glycoursodeoxycholate bound calcium as well as glycochenodexycholate did. Similar results for calcium binding were observed in mixed micelles of bile salts and lecithin. In bicarbonate (25 or 50 mM) and CaCl2 (10 mM) solutions, calcium carbonate formation was inhibited by the bile salts. Glycoursodeoxycholate and glycochenodeoxycholate (25 mM) prevented calcium carbonate formation which was delayed by glycocholate. This effect is not due to differences between both series of bile salts for calcium binding since glycoursodeoxycholate or glycochenodeoxycholate (25 mM) more efficiently prevented calcium carbonate precipitation than did 35 mM glycocholate in spite of the same Ca2+ binding. These results suggest that some bile salts may have a specific role in preventing calcium precipitation in bile. The mechanism is unknown. The physical properties of glycoursodeoxycholate and glycochenodeoxycholate do not support a role for CaCO3 precipitation in gallstone calcification during litholytic therapy.


Asunto(s)
Ácidos y Sales Biliares/metabolismo , Carbonato de Calcio/metabolismo , Ácido Desoxicólico/análogos & derivados , Ácido Ursodesoxicólico/análogos & derivados , Bicarbonatos , Tampones (Química) , Calcinosis/metabolismo , Cloruro de Calcio , Fenómenos Químicos , Precipitación Química , Química , Ácido Quenodesoxicólico/metabolismo , Colelitiasis/metabolismo , Ácido Cólico , Ácidos Cólicos/metabolismo , Humanos , Técnicas In Vitro , Micelas , Sodio , Bicarbonato de Sodio , Ácido Ursodesoxicólico/metabolismo
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