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1.
Eur J Surg Oncol ; 41(3): 378-85, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25515823

RESUMO

BACKGROUND: Although implantation of a central venous device such as a Port-a-Cath was initially considered safe, extravasation rates up to 4.7% have been reported. Therefore, the objective of this study was to propose a structured procedure for the management of extravasation of a cytotoxic treatment. METHODS: A total of eight patients were evaluated after port extravasation of epirubicin (n = 3), platinum compounds (n = 3), paclitaxel (n = 1), or trabectedin (n = 1) into the subcutaneous space. Immediate explantation of the port was performed in combination with a "Subcutaneous Wash-Out Procedure" (SWOP). When removal of the port was delayed, débridement and flap coverage were performed as necessary. Epirubicin concentrations present in the samples obtained during surgical intervention were subsequently analysed using high-performance liquid chromatography (HPLC). Patients were followed for at least six months and were examined for sequelae such as pain, induration, redness, and limited movement. RESULTS: All three patients whose extravasation event was detected during chemotherapy administration benefited from SWOP with acceptable side effects (e.g., erythema). The analysis of epirubicin concentrations demonstrated the active removal of relevant amounts of the compound by wound rinsing. In contrast, late detection of extravasation led to major débridement and flap coverage in four out of five patients. A high body mass index (BMI) value was associated with all of the patients that experienced port extravasation. CONCLUSION: Depending on when Port-a-Cath extravasations into subcutaneous tissue are detected, different treatments are appropriate. When extravasation is detected early, the SWOP was found to be beneficial.


Assuntos
Antineoplásicos/administração & dosagem , Remoção de Dispositivo/métodos , Falha de Equipamento , Extravasamento de Materiais Terapêuticos e Diagnósticos/cirurgia , Neoplasias/tratamento farmacológico , Dispositivos de Acesso Vascular , Adulto , Idoso , Antineoplásicos/efeitos adversos , Índice de Massa Corporal , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Dioxóis/administração & dosagem , Dioxóis/efeitos adversos , Epirubicina/administração & dosagem , Epirubicina/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Organoplatínicos/administração & dosagem , Compostos Organoplatínicos/efeitos adversos , Oxaliplatina , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Fatores de Risco , Retalhos Cirúrgicos , Tetra-Hidroisoquinolinas/administração & dosagem , Tetra-Hidroisoquinolinas/efeitos adversos , Irrigação Terapêutica , Trabectedina , Adulto Jovem
2.
Obes Surg ; 18(11): 1381-6, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18438619

RESUMO

BACKGROUND: Beside complications like band migration, pouch-enlargement, esophageal dilation, or port-site infections, laparoscopic adjustable gastric banding (LAGB) has shown poor long-term outcome in a growing number of patients, due to primary inadequate weight loss or secondary weight regain. The aim of this study was to assess the safety and efficacy of laparoscopic conversion to Roux-en-Y gastric bypass (RYGBP) in these two indications. METHODS: A total of 25 patients, who underwent laparoscopic conversion to RYGBP due to inadequate weight loss (n = 10) or uncontrollable weight regain (n = 15) following LAGB, were included to this prospective study analyzing weight loss and postoperative complications. RESULTS: All procedures were completed laparoscopically within a mean duration of 219 +/- 52 (135-375) min. Mean body weight was reduced from 131 +/- 22 kg (range 95-194) at time of the RYGBP to 113 +/- 25, 107 +/- 22, and 100 +/- 21 kg at 3, 6, and 12 months, respectively, which results in excess weight losses (EWL) of 28.3 +/- 9.9%, 40.5 +/- 12.3%, and 50.8 +/- 15.2%. No statistically significant differences were found comparing weight loss within these two groups. CONCLUSION: RYGBP was able to achieve EWLs of 37.6 +/- 16.1%, 48.5 +/- 15.1%, and 56.9 +/- 15.0% at 3, 6, and 12 months following conversion, respectively, based on the body weight at LAGB.


Assuntos
Derivação Gástrica , Gastroplastia , Aumento de Peso , Redução de Peso , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reoperação
3.
Obes Surg ; 15(7): 1024-9, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16105401

RESUMO

BACKGROUND: Different changes of plasma ghrelin levels have been reported following gastric banding, Roux-en-Y gastric bypass, and biliopancreatic diversion. METHODS: This prospective study compares plasma ghrelin levels and weight loss following laparoscopic sleeve gastrectomy (LSG) and laparoscopic adjustable gastric banding (LAGB) in 20 patients. RESULTS: Patients who underwent LSG (n=10) showed a significant decrease of plasma ghrelin at day 1 compared to preoperative values (35.8 +/- 12.3 fmol/ml vs 109.6 +/- 32.6 fmol/ml, P=0.005). Plasma ghrelin remained low and stable at 1 and 6 months postoperatively. In contrast, no change of plasma ghrelin at day 1 (71.8 +/- 35.3 fmol/ml vs 73.7 +/- 24.8 fmol/ml, P=0.441) was found in patients after LAGB (n=10). Increased plasma ghrelin levels compared with the preoperative levels at 1 (101.9 +/- 30.3 fmol/ml vs 73.7 +/- 24.8 fmol/ml, P=0.028) and 6 months (104.9 +/- 51.1 fmol/ml vs 73.7 +/- 24.8 fmol/ml, P=0.012) after surgery were observed. Mean excess weight loss was higher in the LSG group at 1 (30 +/- 13% vs 17 +/- 7%, P=0.005) and 6 months (61 +/- 16% vs 29 +/- 11%, P=0.001) compared with the LAGB group. CONCLUSIONS: As a consequence of resection of the gastric fundus, the predominant area of human ghrelin production, ghrelin is significantly reduced after LSG but not after LAGB. This reduction remains stable at follow-up 6 months postoperatively, which may contribute to the superior weight loss when compared with LAGB.


Assuntos
Gastrectomia , Gastroplastia , Obesidade Mórbida/fisiopatologia , Hormônios Peptídicos/sangue , Adulto , Feminino , Grelina , Humanos , Laparoscopia , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/sangue , Obesidade Mórbida/cirurgia , Estudos Prospectivos , Redução de Peso
4.
Med Pediatr Oncol ; 37(4): 357-64, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11568899

RESUMO

BACKGROUND: So far, there is no approved tumour marker for diagnosis or follow-up in Wilms tumour (WT). Tissue polypeptide-specific antigen (TPS), a cytokeratin 18 proteolytic fragment, has been suggested to be of value in the clinical management of WT patients. Cytokeratin 18 fragments are an early indicator of apoptosis and cytokeratin 18 might influence tumour cell behaviour. We investigated TPS expression in specimens of WT and other paediatric renal malignancies PROCEDURE: Immunoreactivity of WT sections (n = 9), clear cell sarcomas (CCSK, n = 3), and a renal cell carcinoma (RCC), and two pediatric kidney tumour cell lines (WT: SK-NEP-1 and rhabdoid tumour of the kidney: G-401) were investigated using the monoclonal antibody M3. Additionally, immunoblotting and RT-PCR analysis were performed. Cell culture supernatants were evaluated for TPS release. Serum TPS was measured in five patients at diagnosis, during chemotherapy and after surgical resection. RESULTS: Moderate to strong immunoreactivity for TPS was found in tubular and blastemal components of nearly all (8/9) WT specimens. This was confirmed by Western-blotting. Cystic and epithelial-like portions of CCSKs and RCC showed distinct reactivity (3/3). The supernatant of G-401 but not of SK-NEP-1 showed a time- and cell number-dependent increase of TPS release. Interestingly, TPS synthesis was demonstrated in SK-NEP-1 cells. Median preoperative serum TPS was elevated (293 U/l) compared to healthy children and lowest after surgical resection (49.5 U/l). CONCLUSIONS: This is the first study demonstrating the synthesis and release of TPS by WTs and other paediatric renal malignancies. Considering the elevated levels of TPS in serum of these patients, a further investigation of this marker by larger clinical trials seems to be justified.


Assuntos
Biomarcadores Tumorais/análise , Queratinas/metabolismo , Neoplasias Renais/metabolismo , Peptídeos/análise , RNA Mensageiro/análise , Tumor de Wilms/metabolismo , Adolescente , Sequência de Bases , Biópsia por Agulha , Western Blotting , Linhagem Celular , Criança , Pré-Escolar , Feminino , Imunofluorescência , Humanos , Imuno-Histoquímica , Lactente , Recém-Nascido , Queratinas/análise , Neoplasias Renais/patologia , Masculino , Dados de Sequência Molecular , Prognóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Tumor de Wilms/patologia
6.
J Surg Oncol ; 76(4): 289-96, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11320522

RESUMO

BACKGROUND: Solid-pseudopapillary tumor of the pancreas (SPT) is an exceptionally rare neoplasm in children. Its origin remains enigmatic. It is of low malignant potential and occurs most frequently in young females. PATIENTS AND METHODS: A cumulative review of the tumor's clinicopathological characteristics from the world's literature is presented. The clinical course, pathohistologic data and outcome of surgery of four Austrian children treated at the general hospital of Vienna are analyzed. RESULTS: Between 1987 and 1999, four girls (age: 12--16 years) with SPT were diagnosed at our institution. All patients presented with an abdominal mass and uncharacteristic abdominal pain. Two tumors were located in the tail, one in the body and tail and one in the head of the pancreas (diameter: 7--15 cm). Surgical procedures included three distal pancreatectomies and one partial duodenopancreatectomy (Whipple procedure). One patient had two recurrences with metastases that could only be partially resected. Chemotherapy was initiated for this patient. In the follow-up period (range: 6 months to 12 years) all patients are alive with no evidence of recurrence. CONCLUSIONS: SPT is a rare differential diagnosis of a pancreatic mass in children. It is mandatory to establish this diagnosis since complete surgical removal of the tumor even in case of metastases or local invasion offers an excellent prognosis.


Assuntos
Cistadenoma Papilar/patologia , Neoplasias Pancreáticas/patologia , Adolescente , Criança , Cistadenoma Papilar/metabolismo , Cistadenoma Papilar/cirurgia , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/cirurgia
8.
JSLS ; 4(2): 121-4, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10917118

RESUMO

Although between 4% and 20% of all appendectomies in adults are performed laparoscopically, this procedure is rarely done in the pediatric age group because of the substantially more difficult technique, the expected risks and suspected higher rate of complications. In a prospective study of 500 consecutive appendectomies, we tried to assess the actual rate of complications of each operative approach. We included 362 conventional and 138 laparoscopic appendectomies, the median age of the patients was 10.8 years. The mortality was 0 in both groups. We observed 89 minor and 11 major complications. All major complications (wound infections needing re-operation under general anesthesia, intra-abdominal abscesses, ileus due to adhesions and a case of renal insufficiency because of glomerulonephritis) occurred in the conventional group (n=11, ie, 3% of 362 open appendectomies). Seventy-two minor complications were seen in the same group (20%). In the laparoscopic group, there were 17 (13%) minor complications and no severe complications. This difference was statistically significant. We conclude that in children laparoscopic appendectomy does not carry a greater risk of intra- or postoperative complications and can therefore safely be established as a standard procedure.


Assuntos
Apendicectomia/métodos , Apendicite/cirurgia , Laparoscopia , Adolescente , Adulto , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Complicações Pós-Operatórias , Estudos Prospectivos
9.
Klin Padiatr ; 212(2): 64-70, 2000.
Artigo em Alemão | MEDLINE | ID: mdl-10812555

RESUMO

Progressive familial intrahepatic cholestasis (PFIC) is a congenital liver disease. First symptoms can frequently be seen shortly after birth. Quality and expectation of life are substantially reduced due to severe pruritus and the complications of progressive liver cirrhosis. PFIC is diagnosed on the basis of characteristic clinical and laboratory parameters and genetic analysis after exclusion of other liver diseases leading to intrahepatic cholestasis. Medical therapy is only effective in a proportion of children with PFIC. Partial biliary diversion (PBD) is nowadays considered the therapy of choice in patients with therapy-refractive pruritus. If performed in time, damage to the liver can be delayed or arrested, thus orthotopic liver transplantation (OLT) can be postponed or even avoided in at least some patients with PFIC. Besides providing a current overview of PFIC, we report on three patients who were successfully treated surgically. One patient was subjected to a new technique of PBD (cholecysto-appendicostomy), the other two had OLT.


Assuntos
Colestase Intra-Hepática/congênito , Apêndice/cirurgia , Desvio Biliopancreático , Colestase Intra-Hepática/complicações , Colestase Intra-Hepática/cirurgia , Feminino , Vesícula Biliar/cirurgia , Humanos , Lactente , Recém-Nascido , Cirrose Hepática/etiologia , Transplante de Fígado , Masculino , Prurido/etiologia
10.
Pediatr Pulmonol ; 27(5): 336-40, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10344713

RESUMO

From 1986-1996, 33 children with 49 pulmonary hydatid cysts underwent surgical treatment in Vienna and Istanbul. Cysts were unilateral in 28 and bilateral in 5 cases; unruptured cysts (URC) were diagnosed in 19 patients, and 14 children presented with ruptured cysts (RC). Ten patients had cysts in other organs (liver, spleen, central nervous system) in addition to pulmonary cysts. Diagnosis was primarily based on chest X-ray and computed tomography scan. In Austrian children, a new combination of serological tests was used successfully (71% positive). The standard surgical procedure was cystotomy followed by capitonnage. The main postoperative complications were fever and wound infection. There were two recurrences after a mean follow-up of 4.8 years, and one patient died because of multiple organ involvement. We conclude that the therapy of choice in pediatric pulmonary hydatidosis is complete surgical elimination of the cyst by cystotomy and capitonnage, whereas more extended resections should be avoided. Ideally, benzimidazole treatment should be combined with surgery. New serological tests can improve diagnostic accuracy.


Assuntos
Equinococose Pulmonar/cirurgia , Adolescente , Animais , Anticorpos Anti-Helmínticos/análise , Criança , Pré-Escolar , Equinococose Pulmonar/diagnóstico por imagem , Echinococcus/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Seguimentos , Humanos , Masculino , Radiografia Torácica , Estudos Retrospectivos , Sucção/métodos , Técnicas de Sutura , Toracotomia , Tomografia Computadorizada por Raios X , Resultado do Tratamento
12.
Br J Cancer ; 78(11): 1503-6, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9836484

RESUMO

Although tissue polypeptide-specific antigen (TPS) has been described as a potentially useful serum marker of tumour activity in adult epithelial tumours, few data are available for childhood malignancies. Neuroblastomas and Wilms' tumours are the commonest types of solid malignancies found in the retroperitoneum of children. At this time, a widely used marker for Wilms' tumour is not available. Using an enzyme-linked immunosorbent assay (ELISA) kit, serum TPS levels in 23 children with neuroblastomas, nine with Wilms' tumours and 22 with benign tumours were evaluated to test the usefulness of the marker in identifying malignancies. Compared with healthy children (n = 110), the preoperative least-square means (LSM) of serum TPS were considerably elevated in both neuroblastoma (LSM = 209 U l(-1)) and Wilms' tumour (LSM = 235 U l(-1)), whereas values in benign tumours were only slightly elevated. Although the Wilms' tumours were associated with higher preoperative serum TPS levels, there was no statistically significant difference compared with neuroblastomas. Receiver operating characteristic analysis (ROC curves) showed a high sensitivity and specificity for both malignancies. Successful treatment resulted in decrease in TPS serum values. Serum TPS measurements in children presenting with abdominal masses can help in diagnosing the two commonest extracranial solid malignancies of childhood. Furthermore, TPS could acquire a pivotal role in monitoring therapy.


Assuntos
Neoplasias Renais/sangue , Proteínas de Neoplasias/sangue , Neuroblastoma/sangue , Antígeno Polipeptídico Tecidual/sangue , Tumor de Wilms/sangue , Análise de Variância , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Neoplasias Renais/diagnóstico , Masculino , Neuroblastoma/diagnóstico , Curva ROC , Tumor de Wilms/diagnóstico
13.
Med Pediatr Oncol ; 29(3): 218-21, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9212848

RESUMO

Measurement of serum concentrations of tissue polypeptide-specific Antigen (TPS) has been demonstrated to the useful in diagnosis and monitoring of adult epithelial tumors. So far, no data have been available on normal or pathologic TPS values in children. Therefore, the present study was designed to evaluate the normal values of TPS in childhood. Using a commercial enzyme linked immunosorbent assay (ELISA) kit, serum TPS was determined in 361 healthy children. Median (M) TPS was found to be 107 U/l at birth (n = 124). By the end of the first week, the value rose to M = 150 U/l (n = 68) and then continuously decreased with age (1 week-1 year, n = 45, M = 88 U/l; 1-7 years, n = 75, M = 51 U/l) until reaching the adult level (8-18 years, n = 49, M = 34 U/l). Additionally, the serum TPS values of 45 mothers right after delivery (M = 161 U/l) were assessed, and there was no correlation to the marker levels determined in the cord blood of their children. The age-dependent distribution of serum TPS in healthy children must be taken into account in the clinical application of this tumor marker.


Assuntos
Antígenos/sangue , Biomarcadores Tumorais/sangue , Peptídeos/sangue , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Parto Obstétrico , Ensaio de Imunoadsorção Enzimática , Feminino , Sangue Fetal/química , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Masculino , Idade Materna , Mães , Período Pós-Parto/sangue , Gravidez , Valores de Referência
14.
Anticancer Res ; 17(4B): 2865-8, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9329549

RESUMO

Tissue Polypeptide Specific Antigen (TPS) may soon be routinely used as a proliferation marker in adult epithelial tumors. So far, no data have been available on normal or pathologic TPS values in children. Therefore the present study was designed to test the marker for the first time in pediatric malignancies. Using a commercial ELISA kit (Beki Diagnostics), serum TPS levels were determined in 270 healthy children and compared with various benign (n = 143) and malignant (n = 58) diseases. In healthy children, we found an age-dependent distribution of TPS values. Median (M) TPS was found to be 105.05 U/l at birth as determined from umbilical cord blood (n = 96). By the end of the first week, the value rose to M = 164 U/l and then continuously decreased with age until reaching the adult level at around 14 years. Patients with benign masses (n = 29) did not show elevated serum TPS in contrast to children with malignancies. Advanced tumor stage, metastases, and low dignity correlated with an increase in serum values. In many cases, chemotherapy and especially surgical resection of the tumor were followed by a decrease of the previously markedly elevated TPS levels. Severe infections and impaired renal function were however related with very high values and this must be taken into account when judging the validity of TPS measurements. The marker appears useful for the differential diagnosis between benign and malignant processes. While previous investigators described its use exclusively in epithelial tumors of adults, we cannot confirm this specifity in pediatric patients: Our data show that elevated TPS values in children can also be observed in nonepithelial tumors.


Assuntos
Biomarcadores Tumorais/sangue , Neoplasias/sangue , Peptídeos/sangue , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Neoplasias Renais/sangue , Neuroblastoma/sangue , Tumor de Wilms/sangue
15.
Yale J Biol Med ; 70(4): 459-69, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9626766

RESUMO

Canalicular bile formation is a complex process that involves basolateral and apical cell membrane transport, paracellular transport and vesicular transport, all of which may be subject to regulation by pH. We review the concept that apical cell membrane bicarbonate secretion promotes bile salt independent canalicular bile formation. We show that the presence of paracellular electrolyte transport imposes a severe restriction in interpreting data from ion substitution experiments aimed at demonstrating pH or bicarbonate dependent bile formation. Furthermore, we report on experiments that all show stimulation of bile flow under three disparate experimental conditions: i) intracellular alkalinization in the absence of [HCO3-]i or associated with a decrease of [HCO3-]i, ii) intracellular alkalinization with an increase of [HCO3-]i, and iii) intracellular acidification with increase of [HCO3-]i. It is suggested that both, intracellular pH and intracellular bicarbonate may modulate canalicular bile salt independent bile formation, but it remains conjectural which mechanism is the prevailing one under a given experimental setting.


Assuntos
Ácidos e Sais Biliares/metabolismo , Canalículos Biliares/metabolismo , Animais , Bicarbonatos/metabolismo , Soluções Tampão , Membrana Celular/metabolismo , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Líquido Intracelular/metabolismo , Transporte de Íons , Masculino , Perfusão
17.
Biochim Biophys Acta ; 1103(1): 51-61, 1992 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-1730021

RESUMO

Modulation of hepatic cholate transport by transmembrane pH-gradients and during interferences with the homeostatic regulation of intracellular pH and K+ was studied in the isolated perfused rat liver. Within the concentration range studied uptake into the liver was saturable and appeared to be associated with release of OH- and uptake of K+. Perfusate acidification ineffectually stimulated uptake. Application of NH4Cl caused intracellular alkalinization, release of K+ and stimulation of cholate uptake, withdrawal of NH4Cl resulted in intracellular acidification, regain of K+ and inhibition of cholate uptake. Inhibition of Na+/H(+)-exchange with amiloride reduced basal release of acid equivalents into the perfusate, initiated K(+)-release, and inhibited both, control cholate uptake and its recovery following intracellular acidification. K(+)-free perfusion caused K(+)-release and inhibited cholate uptake. K(+)-readmission resulted in brisk K(+)-uptake and recovery of cholate transport. Both effects were inhibited by amiloride. Interference with cholate transport through modulation of pH homeostasis by diisothiocyanostilbenedisulfonate (DIDS) could not be demonstrated because DIDS affected bile acid transport directly. Biliary bile acid secretion was stimulated by intracellular alkalinization and by activation of K(+)-transport. Uncoupling of the mutual interference between pH-dependent cholate uptake and K(+)-transport by amiloride indicates tertiary active transport of cholate. In this, Na+/K(+)-ATPase provides the transmembrane Na(+)-gradient to sustain Na+/H(+)-exchange which maintains the transmembrane pH-gradient and thus supports cholate uptake. Effects of canalicular bile acid secretion are consistent with a saturable, electrogenic transport.


Assuntos
Ácidos Cólicos/metabolismo , Fígado/metabolismo , Potássio/metabolismo , Ácido 4,4'-Di-Isotiocianoestilbeno-2,2'-Dissulfônico , Ácido 4-Acetamido-4'-isotiocianatostilbeno-2,2'-dissulfônico/análogos & derivados , Amilorida/farmacologia , Animais , Ácidos e Sais Biliares/metabolismo , Transporte Biológico , Membrana Celular/efeitos dos fármacos , Membrana Celular/fisiologia , Ácidos Cólicos/farmacologia , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Cinética , Fígado/citologia , Masculino , Potenciais da Membrana , Ratos
19.
Pflugers Arch ; 419(2): 215-7, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1961691

RESUMO

The pH-sensitive fluorescent dye 1,3-dihydroxy-pyrene-6,8-disulfonic acid (DHPDS) was used to measure intracellular pH (pHi) from the surface fluorescence of the isolated perfused rat liver. Monochromatic light from a fluorometer was focused on the liver with a fiber optic, emitted light was collected with a second fiber bundle and returned to the spectrometer. To correct for changes in intracellular dye concentration, the excitation wavelength was changed between the pH-sensitive excitation peak wavelength and the isosbestic wavelength, then a ratio was computed between fluorescence intensities at these two wavelengths. Intracellular calibration of the dye was performed by clamping the intracellular to the extracellular pH with H+/K(+)-ionophore Nigericin. This method was used to monitor transient changes in intracellular pH caused either by addition and removal of NH4Cl or by changing perfusate CO2 and HCO3- concentrations while keeping their ratio constant. The effects of these maneuvers on bileflow were studied, too. Data obtained in the perfused liver were in good agreement with those obtained in isolated liver cells except that the steady-state pHi (7.46 +/- 0.02) was slightly higher than reported values. Measurements in livers of mutant TR- rats that are defective of dye secretion revealed similar pHi values, indicating that secretion of the dye into bile canaliculi did not affect measurements. The technique appears adequate to measure pHi in the liver and will allow to study pH regulatory mechanisms in the intact organ.


Assuntos
Tecnologia de Fibra Óptica , Fígado/fisiologia , Animais , Corantes Fluorescentes , Concentração de Íons de Hidrogênio , Fígado/metabolismo , Masculino , Fibras Ópticas , Ratos
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