Biomedical subjects

Guido Beldi

Publications and source records attributed to Guido Beldi.

8 recordsLinked to original sources

PubMed2006

Regenerative capacity of individual liver lobes in the microsurgical mouse model.

In the development of microsurgical mouse models of hepatic regeneration and repair, lobe-specific regenerative responses were observed. We therefore determined the hepatic regenerative capacity of individual mouse liver lobes. In mice, 26, 60, 75, and 83% of total liver mass was resected. Bromo-deoxyuridine (BrdU) was injected prior to liver harvest and the BrdU labeling index determined in all remaining individual liver lobes. BrdU-positive nuclei were seen in all liver lobes after the 26 and 60% resection, but significantly fewer were detected in the caudate lobe. In the 75% group, equally distributed positive nuclei were found. However, BrdU labeling was scant in the 83% group. In microsurgical mouse liver-regeneration models, the average hepatic response depends on amount of liver tissue resected and on the remaining liver lobe. BrdU incorporation can vary significantly among individual lobes. The lobe-specific differences observed may prove valuable in further investigations of hepatic regeneration and repair.

Animals↗

PubMed2005

Interleukin-3 induces hepatocyte-specific metabolic activity in bone marrow-derived liver stem cells.

Bone marrow-derived adult liver stem cells (BALSC) are a promising target for the development of future cell-based therapies for a variety of liver disorders. However, the ability of stem cells to fully function, as hepatocytes, is limited and differentiation is time dependent. Therefore, it will be conducive to find a growth factor that is able to enhance liver-specific metabolic activity in freshly isolated liver stem cells. Recently, a subpopulation of BALSC was isolated and characterized (beta2-microglobulin-negative/ Thy-1-positive cells). We hypothesized that using interleukin-3 (IL-3), a hematopoietic differentiation growth factor, we may be able to enhance liver-specific metabolic activity in freshly isolated BALSC. Rat BALSC from normal and injured livers (bile duct ligated) were isolated and stimulated with IL-3 in culture. Cells were co-cultured with or without hepatocytes, separated by a semipermeable membrane. We measured the effect of IL-3 on BALSC to metabolize ammonia into urea (a liver-specific metabolic activity). IL-3 increased the ability of BALSC, purified from normal animals, to metabolize ammonia into urea by several folds. Interestingly, no such effect was found in cell cultures from bile duct-ligated animals. Additionally, co-cultures of BALSC with hepatocytes induced higher rate of ammonia metabolism, which was further enhanced by IL-3. Our study indicates that IL-3 may be used as an agent to enhance differentiation of BALSC, both qualitatively and quantitatively. It is conceivable that stem cells may undergo IL-3 priming before their clinical application in cell transplantation or bioartificial liver systems.

Ammonia↗

PubMed2005

Molecular absorbent recirculating system for the treatment of acute liver failure in surgical patients.

The Molecular Adsorbent Recirculating System (MARS) represents an attractive artificial liver support system for the treatment of liver insufficiency. However, neither indications for MARS treatment (i.e., after extended liver resection) nor criteria for discontinuation of therapy have been evaluated. Therefore, we analyzed the clinical data of all our surgical patients who received MARS treatment for acute liver failure (n = 7). The aim of the study was to identify prognostic indicators for survival. Four of 174 patients resected for hepatic malignancy at our institution received a total of 13 MARS treatments. Two additional patients were successfully bridged to orthotopic liver transplantation with seven MARS treatments and one patient was MARS supported after liver transplantation of a steatotic graft with three MARS treatments. Five of the seven patients survived and were dismissed an average of 31 days, ranging from 17 to 47 days, after the final MARS treatment. No technical complications or adverse effects were observed during the MARS treatments. Important prognostic factors for hepatic recovery and survival were indocyanin green plasma disappearance rates greater than 5%/min and an increase in clotting factor V levels after each MARS treatment. We conclude that MARS therapy can be an effective treatment of postoperative liver insufficiency in the surgical hepatobiliary unit.

Adult↗

PubMed2004

Evaluation of intraoperative recurrent nerve monitoring in thyroid surgery.

Surgical exposure of the recurrent laryngeal nerve decreases the incidence of nerve injuries during thyroid surgery. Intraoperative neuromonitoring was introduced to facilitate identification and protection of the recurrent laryngeal nerve. Between February 1996 and June 2002 a total of 288 patients underwent thyroid surgery with intraoperative identification and intraoperative neuromonitoring of the recurrent laryngeal nerve. The overall incidences of permanent and transient recurrent nerve palsy (considered as a percentage of the nerves at risk) were 1.4% and 8.7%, respectively. Results were stratified in benign, malignant, and recurrent thyroid disease. Intraoperative function testing revealed a positive predictive value of 33% and negative predictive value of 99%. We concluded that the incidence of recurrent nerve lesions in benign, malignant, and recurrent thyroid disease was not lowered by the use of intraoperative neuromonitoring. Although an intact nerve can be verified by the neuromonitoring, the loss of nerve function cannot be reliably identified.

Adolescent↗

PubMed2004

Magnetic resonance imaging provides accurate and precise volume determination of the regenerating mouse liver.

Direct and repetitive noninvasive determination of the time course and the strain-specific hepatic regenerative capacity after partial hepatectomy can extend our knowledge about the basic mechanisms of liver regeneration and repair. The aim of this study was to develop a magnetic resonance (MR)-based volumetric procedure to measure the hepatic volume in the regenerating mouse liver. In Balb-C mice (n = 14), varying amounts of liver tissue were resected and MR imaging was performed 24 hours later in a 1.5 Tesla Magnet Unit. Three dimensional (3D) T1- (volumetric interpolated breath-hold examination [VIBE] sequence) and T2-weighted images were acquired with continuous 1-mm thin slices. Animals with and without intravenous administration of paramagnetic contrast agents were compared. Immediately after MR examination, mice were euthanized and livers were weighted. The liver volume was determined on MR images using Cavalieri's method and linear regression analysis was performed from the data obtained. Correlation coefficients between the liver volume measured by MR and the liver weight were 0.98 (T1) and 0.94 (T2) in the group without paramagnetic contrast injection and 0.70 (T1) and 0.96 (T2) after paramagnetic contrast application. We conclude that MR-based liver volumetry allows precise liver volume measurement during hepatic regeneration after partial hepatectomy in mice and can be a valuable tool with regard to experimental hepatology.

Animals↗

PubMed2002

Mural thrombus of the aorta in association with homozygous plasminogen activator inhibitor type 1 (PAI-1)-675(4G) and heterozygous GP Ia 807C/T genotypes.

Thrombus formation in the thoracic and abdominal aorta without evidence of arteriosclerotic disease is very uncommon. We present a case of a 50-year-old woman with a mural thrombus of the upper abdominal aorta associated with a combination of two mutations predisposing for thrombophilia. The genetic analysis showed a homozygous mutation of plasminogen activator inhibitor type 1 (PAI-1)-675 (4G) and a heterozygous mutation of GP Ia 807C/T. To our knowledge, this is the first report of the combination of both mutations occurring in a patient with isolated thrombus formation of the aorta.

Aorta, Abdominal↗

PubMed2002

Long-term gastrointestinal symptoms after laparoscopic nissen fundoplication.

Patients who have undergone fundoplication may be at risk for recurrent gastroesophageal reflux and may experience postoperative gastrointestinal symptoms. We investigated the long-term symptomatic outcome after laparoscopic Nissen fundoplication. Between 1993 and 1998 we treated 60 patients with laparoscopic fundoplication for gastroesophageal reflux disease. Signs of recurrence and gastrointestinal symptoms were assessed in 55 (92%) patients after a minimum follow-up of 1 year (median: 3.6 years). At follow-up, 52 patients (95%) were completely free of reflux symptoms. Mild gastrointestinal symptoms (flatulence, 60%; early satiety, 51%; meteorism, 42%; inability to vomit, 27%; dysphagia, 25%; diarrhea, 25%; epigastric pain, 24%; inability to belch, 22%) were found in a total of 51 patients (93%). Disturbing symptoms occurred in only 9 patients (16%). Laparoscopic Nissen fundoplication results in excellent control of gastroesophageal reflux disease at long-term follow-up. Despite a high rate of gastrointestinal symptoms, patient satisfaction showed the operation to be effective and well tolerated.

Adult↗

PubMedDate not supplied

Intraoperative three-dimensional fluoroscopic cholangiography.

Precise intraoperative assessment of the architecture of the biliary tree could reduce lesions to intra- or extrahepatic bile ducts. The aim of this study was to test feasibility of intraoperative three-dimensional imaging during liver resections. Isocentric C-arm fluoroscopy acquires three-dimensional images during a 190 degrees orbital rotation. The bile ducts were displayed three-dimensionally by realtime rotational projections or multiplanar reconstructions. The technique was established ex vivo in a preserved cadaveric human liver. Intraoperative three-dimensional cholangiography was performed in five patients with centrally located liver malignancies. Complete data acquisition in 3 patients depicted precise anatomical details of the architecture of the biliary tree up to third order divisions. Biliary imaging can be improved by the application of real-time intraoperative three-dimensional cholangiography. For the development of computer-aided navigation in hepatobiliary procedures, this technique could be an important prerequisite for defining landmarks of the liver in a three-dimensional space.

Aged↗