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Biomedical subjects

D Jaeck

Publications and source records attributed to D Jaeck.

At least 55 records · Page 3Linked to original sources
PubMed1999

Infection of primary cultures of human Kupffer cells by Dengue virus: no viral progeny synthesis, but cytokine production is evident.

We investigated the ability of dengue virus to invade human primary Kupffer cells and to complete its life cycle. The virus effectively penetrated Kupffer cells, but the infection did not result in any viral progeny. Dengue virus-replicating Kupffer cells underwent apoptosis and were cleared by phagocytosis. Infected Kupffer cells produced soluble mediators that could intervene in dengue virus pathogenesis.

Apoptosis↗
PubMed1999

Perioperative hepatic functional risk assessed with technetium-99m diethylenetriamine pentaacetic acid-galactosyl human serum albumin liver scintigraphy in patients undergoing pancreaticoduodenectomy complicated by obstructive jaundice.

CONCLUSION: Liver scintigraphy with technetium-99m diethylenetriamine pentaacetic acid-galactosyl human serum albumin (Tc-GSA) can be used to predict outcome of biliary drainage and hepatic function after pancreaticoduodenectomy in patients with pancreatic, biliary, and ampullary carcinomas complicated by obstructive jaundice. BACKGROUND: Preoperative obstructive jaundice has been reported as a crucial risk factor for serious postoperative complications in patients undergoing pancreaticoduodenectomy. The aim of the present study was to investigate whether Tc-GSA liver scintigraphy can assess hepatic functional risk in patients with pancreatic, biliary, and ampullary carcinomas complicated by obstructive jaundice. METHODS: Liver scintigraphy was performed before biliary drainage in 18 patients with obstructive jaundice. The maximum removal rate of Tc-GSA (GSA-Rmax; standard normal value > or = 0.60) was calculated. These patients underwent pancreaticoduodenectomy with wide lymphadenectomy. The efficacy of preoperative biliary drainage was assessed with the decrease in serum bilirubin concentration in the first week after biliary drainage. Postoperative liver function was assessed with the increase in serum bilirubin concentration, which was the difference between the immediate preoperative and maximal postoperative bilirubin concentrations. RESULTS: Serum bilirubin decreased more in the first week after biliary drainage in patients with GSA-Rmax > or = 0.60 (7.64 +/- 1.09 mg/Dl/wk) than in patients with GSA-Rmax < 0.60 (3.56 +/- 1.25 mg/DL/wk, p = 0.042). Postoperative bilirubin increased less in patients with GSA-Rmax > or = 0.60 (0.81 +/- 0.30 mg/dL) than in patients with GSA-Rmax < 0.60 (4.00 +/- 0.69 mg/DL, p = 0.0012). Multivariate analysis showed that GSA-Rmax significantly predicted the postoperative bilirubin increase (p = 0.020).

Adult↗
PubMed1998

[Evaluating the risk of axillary lymph node involvement in inferior breast cancer measuring 3 centimeters. Analysis of a predictive model based on 893 cases].

STUDY AIM: The aim of the study was to assess, by clinical and histological predictive factors, the axillary lymph-node involvement (pN+) in early breast cancers. MATERIALS AND METHODS: Eight hundred ninety-three patients with unilateral invasive breast cancer were studied. The evaluated parameters included clinical size (T), pathological size (pT), histological subtype (ductal infiltrating, according to grading 1, 2, 3, lobular infiltrating and others), age (less than 40, 40 to 60 and above 60). Furthermore, a new parameter, the dosimetric breast size, recently described, was included (Eur J Cancer 1997; 33: 2432-4). RESULTS: The global rate of pN+ was 25.3%, with respectively, pN1: 10%, pN2-3: 8.4% and pN > 3: 6.9%. According to T, the pN+ rates were, respectively, 13.8%, 19.8% and 36.2% in the T0, T1 and T2 < or = 3 cm groups. According to pT, the pN+ rates were, respectively, 11.1%, 17.7%, 23.5%, 30.1% and 36% in the following groups: 0-9.9 mm, 10-14.9 mm, 15-19.9 mm, 20-24.9 mm and 25-29.9 mm. For the ductal infiltrating carcinoma, according to the gradings 1, 2 and 3, we found, respectively, 18.3%, 27.2% and 37.8% of pN+. For the lobular infiltrating carcinoma and the other histological subtypes, the rates were 22.7% and 10%, respectively. For the three age categories cited above the pN+ rates were, respectively, 30.3%, 25.8% and 22.4%. According to breast size we found 30.1% and 24.4% of pN+ respectively for small and medium or large dosimetric breast size. After a multivariate analysis, three factors were significant for pN+ risk: clinical tumor size (P = 0.0001), histological subtype (P = 0.0005) and dosimetric breast size (P = 0.004). With a combination of these three factors, the pN+ rates varied from 5% to 50%. CONCLUSIONS: The authors conclude that both clinical and pathological characteristics of the primary tumor (specified by previous core biopsy) can indicate the risk for axillary node metastases, and allow selection of candidates for limited axilla surgery (sentinel node).

Adult↗
PubMed1998

Removal of primate xenoreactive natural antibodies by extracorporeal perfusion of pig kidneys and livers.

Organ perfusion is one of the possible strategies to attenuate rejection of discordant xenografts by reducing the levels of the recipient's xenoreactive natural antibodies (XNA). Its efficacy in terms of XNA removal was studied in models of primate blood or plasma perfusion through porcine kidneys or livers, with special attention to haematological consequences and potential side-effects. We first perfused the blood of rhesus monkeys through pig kidneys and livers, and demonstrated that the perfusion of a pig liver resulted in higher XNA adsorption (72 +/- 13%) than the perfusion of a pig kidney (51 +/- 25%). However, when we normalized for the weight of the perfused organs and for levels of natural antibodies in individual monkeys, livers adsorbed less antibody (1.4 +/- 0.9 U antibody/g) than kidneys (7.2 +/- 7 U antibody/g). Histological signs of rejection were observed in perfused kidneys, but not in perfused livers. A major drawback of the perfusion of blood through livers was a considerable decrease in the primates' haemoglobin and platelet levels. To avoid this, we developed a plasma liver perfusion device. This method allowed a significant improvement in the haemodynamic state of primates and was particularly effective in preventing anaemia. Moreover, plasma liver perfusion was as effective as blood liver perfusion to remove natural antibodies and, resulted in a marked decrease in their functional activity as assessed by complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC). The level of other plasma proteins was not significantly affected, apart from a dilution effect. After xenoperfusion a strong antibody response was evidenced by ELISA, CDC and ADCC between days 7 and 14 and then decreased progressively. We conclude that the separation of blood to allow the perfusion of plasma through a pig organ is safer than the perfusion of unseparated blood and is associated with efficient natural antibody removal. However, organ perfusion is limited by a rebound in antibody levels after a few days, and thus will have to be associated with anti-B cell immunosuppressive therapy for long-term or repeated applications.

Animals↗
PubMed1998

Efficacy of preconditioning with N-acetylcysteine against reperfusion injury after prolonged cold ischaemia in rats liver in which glutathione had been reduced by buthionine sulphoximine.

OBJECTIVE: To investigate the ability of N-acetylcysteine (NAC) to prevent cold ischaemic-reperfusion injury and improve hepatic integrity in a glutathione-depleted condition. DESIGN: Open laboratory study. SETTING: University hospitals, Japan and France. MATERIALS: 40 male Wistar rats. INTERVENTIONS: To produce a glutathione-depleted liver, buthionine sulphoximine (BSO) was injected intraperitoneally 2 hours before either NAC or 5% dextrose was infused 15 minutes before the liver was harvested. We used an isolated perfused rat liver model that had undergone prolonged hypothermic ischaemia, cold-storage for 48 hours and reperfusion for 120 minutes. MAIN OUTCOME MEASURES: Concentrations of hepatic enzymes released into samples of perfusate, concentration of adenosine triphosphate in liver tissue, concentrations of reduced and oxidized glutathione in perfusate, and bile production. RESULTS: The concentrations of the hepatocellular enzymes and oxidised glutathione in the perfusate samples were significantly reduced in the NAC group compared with the 5% dextrose group. Bile production improved significantly in the NAC group compared with the 5% dextrose group. The concentration of reduced glutathione in liver tissue was not increased by NAC. CONCLUSION: In a glutathione-depleted liver NAC prevented hepatic injury and improved liver integrity after a cold ischaemic-reperfusion injury, by acting not as a substrate for glutathione synthesis but as a direct free radical scavenger.

Acetylcysteine↗
PubMed1998

Relapse of Graves' disease after subacute thyroiditis.

We report the case of a 46-year-old man whose Graves' disease relapsed 5 years after its first appearance. At the time of relapse thyrotropin (TSH) receptor antibodies were very high, as was radioactive uptake in the left lobe of the thyroid. After thyroidectomy, histological analysis of the specimen showed evidence of treated Graves' disease, and there were signs of subacute thyroiditis in the right lobe. The clinical and immunologic characteristics of this observation are discussed as well as the hypothesis explaining the succession of an inflammatory and autoimmune thyroid disease.

Autoantibodies↗
PubMed1998

Antibodies to human adhesion molecules and von Willebrand factor: in vitro cross-species reactivity in the xenotransplantation setting.

Endothelial cell activation is thought to play an important role in xenograft rejection through cell retraction and expression of pro-coagulant and pro-inflammatory factors. Identification of antibodies recognizing porcine endothelial molecules would be useful to study and manipulate the inflammatory response to a xenograft. The aim of this study was to investigate the cross-reactivity of antibodies directed against human adhesion molecules and von Willebrand factor (vWF). Binding of monoclonal antibodies (mAbs) directed against human CD3 1, CD44, CD49, CD54, CD62E, CD102, and CD106 was evaluated on resting and activated endothelial cells from human and pig by flow cytometry. Among 30 antibodies tested, 4 were shown to react with pig cells. Two of them, directed against human CD62E (E-selectin) and rabbit CD106 (VCAM-1) reacted strongly with activated and/or resting pig cells, whereas two others, directed to human CD31 (PECAM) and CD44 (H-CAM), bound weakly to pig cells. In addition, we analyzed the cross-reactivity of five polyclonal or monoclonal antibodies to human or pig vWF with human, baboon, rhesus, pig, and rat vWF. Binding of antibodies was tested by ELISA by using platelet lysates as source of vWF from the different species. Four anti-human or porcine vWF antibodies exhibited a broad reactivity with vWF from all species, whereas one anti-human vWF antibody was specific for primate vWF. In this study, we identified a small number of cross-reacting antibodies that may prove useful to study in vitro and in vivo xenogeneic responses. However, the weak antibody cross-reactivity observed with most porcine molecules points out the necessity of producing species-specific antibodies to study the immune response to xenografts or for use as specific immunosuppressive therapeutic reagents.

Animals↗
PubMed1998

Metabolic capacities in cultured human hepatocytes obtained by a new isolating procedure from non-wedge small liver biopsies.

A new isolating procedure of human hepatocytes has been developed using two-step collagenase digestion by a non-perfusion procedure (NP) of non-wedge liver biopsies. 1. A yield of 2-7 x 10(6) hepatocytes/g liver, 52-95% viability and 13-75% attachment were obtained from liver biopsies weighing 6-60 g, comparable to that obtained when using the classical perfusion procedure (P) to isolate human hepatocytes from wedge liver samples of 50-150 g. 2. In culture, human hepatocytes obtained by NP remained attached to plastic for up to 5 days and displayed the usual morphological characteristics. Their metabolic capacities, assessed by liver-specific albumin and urea synthesis and by CYP-dependent and conjugation pathways, were equivalent to those of human hepatocytes obtained by P. In addition, they responded adequately to specific CYP inducers, demonstrating that they constitute a model in which human drug metabolism and toxicity studies can be performed.

Adult↗
PubMed1997

Long-term survival following resection of colorectal hepatic metastases. Association Française de Chirurgie.

AIM: The aim of this study was to analyse characteristics of patients who survived more than 5 years after liver resection of colorectal metastases. METHODS: A multicentre retrospective study collected 1818 patients who underwent curative resection of hepatic metastases between 1959 and 1991. Among the 747 patients operated on before 1987, 102 survived longer than 5 years, and were compared with patients who survived less than 5 years. RESULTS: Three risk factors proved independently significant in multivariate analysis between the two groups: serosa infiltration (P = 0.003), involvement of peritumoral lymph nodes around the primary colorectal tumour (P = 0.04), and a liver resection margin of less than 1 cm (P = 0.02). There was no significant difference for other parameters studied (location of primary tumour, location, number and size of metastases, type of resection). A trend towards a shorter survival of patients with increased carcinoembryonic antigen serum level was observed. CONCLUSION: Resection of colorectal hepatic metastases can provide long-term survival even in patients with poor prognostic factors. It seems justified to undertake resection of colorectal liver metastases whenever it may be performed safely as a curative treatment.

Carcinoembryonic Antigen↗
PubMed1997

'Dosimetric breast size': a new and useful parameter for the prediction of local recurrence after breast conservative treatment.

To evaluate the risk of local recurrence following breast-conserving therapy for breast cancer, we measured the distance between each entry point of the irradiation on the surface of the breast in line with the axis of the external and internal tangential fields (dosimetric breast size). 652 breast cancer patients were retrospectively analysed, with a median age of 51 years and a median follow-up of 99 months (range 84-192). There were 50 local recurrences, 44 isolated and 6 associated with nodal recurrence or metastases. The global rates of local recurrences at 5 and 10 years were 5.3% and 9%, respectively (Kaplan-Meier analysis). Following a Cox's multivariate analysis, the only significant and independent parameters related to local recurrence were quality of excision, age at diagnosis and dosimetric breast size. For a small dosimetric breast size (< or = 10 cm), the rate of local recurrence was 14.1 compared with 11.8 for medium dosimetric breast size (> 10 cm-< or = 12 cm) and 5.2 for large dosimetric breast size (> 12 cm). If the analysis was restricted to only those with complete excision, then the relative risk for a patient with a small dosimetric breast size was three times that for a large breast size.

Adult↗