Robotic versus laparoscopic distal pancreatectomy: multicentre analysis

BACKGROUND

The role of minimally invasive distal pancreatectomy is still unclear, and whether robotic distal pancreatectomy (RDP) offers benefits over laparoscopic distal pancreatectomy (LDP) is unknown because large multicentre studies are lacking. This study compared perioperative outcomes between RDP and LDP.

METHODS

A multicentre international propensity score-matched study included patients who underwent RDP or LDP for any indication in 21 European centres from six countries that performed at least 15 distal pancreatectomies annually (January 2011 to June 2019). Propensity score matching was based on preoperative characteristics in a 1 : 1 ratio. The primary outcome was the major morbidity rate (Clavien-Dindo grade IIIa or above).

RESULTS

A total of 1551 patients (407 RDP and 1144 LDP) were included in the study. Some 402 patients who had RDP were matched with 402 who underwent LDP. After matching, there was no difference between RDP and LDP groups in rates of major morbidity (14.2 versus 16.5 per cent respectively; P = 0.378), postoperative pancreatic fistula grade B/C (24.6 versus 26.5 per cent; P = 0.543) or 90-day mortality (0.5 versus 1.3 per cent; P = 0.268). RDP was associated with a longer duration of surgery than LDP (median 285 (i.q.r. 225-350) versus 240 (195-300) min respectively; P < 0.001), lower conversion rate (6.7 versus 15.2 per cent; P < 0.001), higher spleen preservation rate (81.4 versus 62.9 per cent; P = 0.001), longer hospital stay (median 8.5 (i.q.r. 7-12) versus 7 (6-10) days; P < 0.001) and lower readmission rate (11.0 versus 18.2 per cent; P = 0.004).

CONCLUSION

The major morbidity rate was comparable between RDP and LDP. RDP was associated with improved rates of conversion, spleen preservation and readmission, to the detriment of longer duration of surgery and hospital stay.

Risk of conversion to open surgery during robotic and laparoscopic pancreatoduodenectomy and effect on outcomes: international propensity score-matched comparison study

BACKGROUND

Minimally invasive pancreatoduodenectomy (MIPD) is increasingly being performed because of perceived patient benefits. Whether conversion of MIPD to open pancreatoduodenectomy worsens outcome, and which risk factors are associated with conversion, is unclear.

METHODS

This was a post hoc analysis of a European multicentre retrospective cohort study of patients undergoing MIPD (2012-2017) in ten medium-volume (10-19 MIPDs annually) and four high-volume (at least 20 MIPDs annually) centres. Propensity score matching (1 : 1) was used to compare outcomes of converted and non-converted MIPD procedures. Multivariable logistic regression analysis was performed to identify risk factors for conversion, with results presented as odds ratios (ORs) with 95 per cent confidence intervals (c.i).

RESULTS

Overall, 65 of 709 MIPDs were converted (9.2 per cent) and the overall 30-day mortality rate was 3.8 per cent. Risk factors for conversion were tumour size larger than 40 mm (OR 2.7, 95 per cent c.i.1.0 to 6.8; P = 0.041), pancreatobiliary tumours (OR 2.2, 1.0 to 4.8; P = 0.039), age at least 75 years (OR 2.0, 1.0 to 4.1; P = 0.043), and laparoscopic pancreatoduodenectomy (OR 5.2, 2.5 to 10.7; P < 0.001). Medium-volume centres had a higher risk of conversion than high-volume centres (15.2 versus 4.1 per cent, P < 0.001; OR 4.1, 2.3 to 7.4, P < 0.001). After propensity score matching (56 converted MIPDs and 56 completed MIPDs) including risk factors, rates of complications with a Clavien-Dindo grade of III or higher (32 versus 34 per cent; P = 0.841) and 30-day mortality (12 versus 6 per cent; P = 0.274) did not differ between converted and non-converted MIPDs.

CONCLUSION

Risk factors for conversion during MIPD include age, large tumour size, tumour location, laparoscopic approach, and surgery in medium-volume centres. Although conversion during MIPD itself was not associated with worse outcomes, the outcome in these patients was poor in general which should be taken into account during patient selection for MIPD.

Safety and outcome of combined liver and pancreatic resections

Background

In Western countries, combined liver and pancreatic resections (CLPR) are performed rarely because of the perceived high morbidity and mortality rates. This study evaluated the safety and outcomes of CLPR at a tertiary European centre for hepatopancreatobiliary surgery.

Methods

A review of two prospectively maintained databases for pancreatic and liver resections was undertaken to identify patients undergoing CLPR between January 1994 and January 2012. Clinicopathological and surgical outcomes were analysed. Univariable and multivariable analyses for postoperative morbidity were performed.

Results

Fifty consecutive patients with a median age of 58 (range 20–81) years underwent CLPR. Indications for surgery were neuroendocrine carcinoma (16 patients), biliary cancer (15), colonic cancer (5), duodenal cancer (1) and others (13). The type of pancreatic resection included pancreaticoduodenectomy (30), distal pancreatectomy (17), spleen-preserving distal pancreatectomy (2) and total pancreatectomy (1). Twenty-three patients had associated major hepatectomies, 27 underwent minor liver resections and 11 had associated vascular resections. Mortality and morbidity rates were 4 and 46 per cent respectively. Univariable and multivariable analysis showed no differences in postoperative morbidity in relation to extent of liver resection or type of pancreatic resection. Use of preoperative chemotherapy was the only independent risk factor associated with postoperative morbidity (P = 0·021).

Conclusion

CLPR can be performed with fairly low morbidity and mortality rates. Postoperative outcomes were not affected by the extent of liver resection or the type of pancreatic resection. Patients receiving chemotherapy should be evaluated carefully before surgery is considered.

Two-stage hepatectomy for multiple bilobar colorectal liver metastases

BACKGROUND

As surgical resection of colorectal liver metastases (CLM) remains the only treatment for cure, efforts to extend the surgical indications to include patients with multiple bilobar CLM have been made. This study evaluated the long-term outcome, safety and efficacy of two-stage hepatectomy (TSH) for CLM in a large cohort of patients.

METHODS

Patients undergoing surgery between December 1996 and December 2009 were reviewed. The early postoperative and long-term outcomes as well as the patterns of failure to complete TSH and its clinical implications were analysed.

RESULTS

Eighty patients were scheduled to undergo TSH. Sixty-one patients had completion of TSH combined with (58 patients), or without (3) portal vein embolization/ligation (PVE/PVL). Five patients were excluded after first-stage hepatectomy and 14 after PVE/PVL. The 5-year overall survival rate and median survival in patients who completed TSH were 32 per cent and 39·6 months respectively, and corresponding recurrence-free values were 11 per cent and 9·4 months respectively. Six patients were alive beyond 5 years after TSH. Multivariable logistic regression analysis showed that failure to complete TSH was driven by two independent prognostic scenarios: three or more CLM in the future remnant liver (FRL) combined with age over 70 years predicted tumour progression after first-stage hepatectomy, and three or more CLM in the FRL combined with carcinomatosis at the time of first-stage hepatectomy predicted the development of additional FRL metastases after PVE/PVL.

CONCLUSION

A therapeutic strategy using TSH provided acceptable long-term survival with no postoperative mortality. Further efforts are needed to increase the number of patients who undergo TSH successfully.

Preliminary experience with the hanging maneuver for pancreaticoduodenectomy

BACKGROUND

Malignant periampullary tumours often invade retroperitoneal peripancreatic tissues and a positive resection margin following pancreaticoduodenectomy (PD) is associated with a poor survival. The margin most frequently invaded is the retroperitoneal margin (RM). Among the different steps of PD one of the most difficult and less codified is the resection of the RM with high risk of bleeding. We have developed a surgical technique - "hanging maneuver" - which allows at the same time a standardization of this step, a complete resection of the RM, and an optimal control of bleeding.

PATIENTS/METHODS

We described the surgical technique, and we reported our preliminary experience. Surgical data, postoperative outcome and pathological results of patients submitted to PD for pancreatic carcinoma using "hanging maneuver" technique between January 2007 and December 2007 were reviewed.

RESULTS

The hanging maneuver was performed in 20 patients without any intraoperative complication and massive bleeding. No patient required blood transfusion. After had inked the surgical margins, retroperitoneal peripancreatic tissue was invaded in 12 out of 17 patients with malignant diseases (70.5%). In only one case (6%), the retroperitoneal margin was involved by the tumour (R1 resection).

CONCLUSION

The "hanging maneuver" is a useful and safe technical variant and should be considered in the armamentarium of the pancreatic surgeons in order to achieve negative retroperitoneal margins.

Neuropsychological profile of pre-schoolers with metaphonological difficulties: results from a non-clinical sample

BACKGROUND

The level of language development reached in pre-school age is considered the most reliable predictor of reading acquisition. In normally developing children, learning to read is strongly related to early language skills, and in particular to phonological processing abilities. In dyslexic children, reading abilities seem to show a correlation with phonological awareness.

METHODS

A group of 65 children (aged 5-6 years) were recruited and submitted to an in-depth neuropsychological assessment [i.e. metaphonological skills, intelligence, verbal short-term memory (VSTM) and other aspects of receptive and expressive language]. We were able to identify 14 children with significant metaphonological difficulties (MD): 11 children with exclusively MD, and the other three children with specific language impairment. This study compares the neuropsychological profile obtained from children with MD with that of a peer group without any language impairment (N).

RESULTS

The performances of the MD were within the normal ability range in almost all the administered tests but significantly lower compared with those of their peers without language impairment (N) in some items of the intelligence scale (Wechsler Preschool and Primary Scale of Intelligence) and in the tests of VSTM and of receptive/expressive language. Nevertheless, there were not statistically significant differences between MD and N in output phonology.

CONCLUSIONS

In pre-school age, in a group of non-clinical children, with a range of abilities, those with MD appear to be at the lower end of the normal range in many other verbal skills. These children could be considered at-risk for possible subsequent difficulties learning to read and thus need to be identified and to warrant prompt treatment.

Increasing age and APACHE II scores are the main determinants of outcome from pancreatic necrosectomy

BACKGROUND

The aim of this study was to identify factors associated with death after surgery in patients with extensive pancreatic necrosis.

METHODS

Sixty-four patients who underwent pancreatic necrosectomy between 1996 and 2002 were studied.

RESULTS

The median age was 60.5 (95 per cent confidence interval (c.i.) 57 to 64) years and 40 patients (62.5 per cent) were tertiary referrals. The initial median Acute Physiology And Chronic Health Evaluation (APACHE) II score was 9 (95 per cent c.i. 7.9 to 10.1) and there were 21 deaths (32.8 per cent). Twenty-eight patients (43.8 per cent) underwent minimally invasive retroperitoneal pancreatic necrosectomy (MIRP) and the remainder had open pancreatic necrosectomy (OPN); 44 (72.1 per cent) of 61 patients had infected pancreatic necrosis at the time of the first procedure. Seven patients who underwent MIRP died compared with 14 after OPN (P = 0.240). Patients who died were older than those who survived, with higher APACHE II scores at presentation, and before and after surgery (P = 0.001). Survivors had significantly longer times to surgery than those who died (P = 0.038). All 21 patients who died required intensive care compared with 26 of 43 survivors (P < 0.001). Thirty of 36 patients who had the OPN procedure required intensive care compared with only 17 of 28 patients who had MIRP (P = 0.042). Logistic regression analysis showed that only postoperative APACHE II score was an independent predictor of increased mortality (P = 0.031).

CONCLUSION

Advanced age and increasing APACHE II score, and a need for postoperative intensive care, were the most important predictors of outcome after pancreatic necrosectomy.

Minimally invasive retroperitoneal pancreatic necrosectomy

INTRODUCTION

Open surgery for pancreatic necrosis is associated with considerable morbidity and mortality. We report the results of a recently developed minimally invasive technique that we adopted in 1998.

METHODS

A descriptive explanation of the approach is given together with the results of a retrospective analysis of patients who underwent a minimally invasive retroperitoneal pancreatic necrosectomy (MIRP) between August 1998 and April 2002.

PATIENTS

There were 24 patients with a median (range) age of 61 (29-75) years. The initial median (range) APACHE II score was 8 (2-21). All patients had infected pancreatic necrosis with at least 50% pancreatic necrosis. In three patients it was not possible to complete the first MIRP because of technical reasons.

RESULTS

A total of 88 procedures were performed with a median (range) of 4 (0-8) per patient. Twenty-one (88%) patients developed 36 complications during the course of their illness. Five patients required an additional open procedure: 2 for subsequent distant collections, 2 for bleeding and 1 for persisting sepsis and a distant abscess. Six (25%) patients who had MIRP died. The median (range) post-operative hospital stay was 51 (5-200) days.

CONCLUSIONS

MIRP is a new technique that has shown promising results, and could be preferable to open pancreatic necrosectomy in selected patients. However, unresolved issues remain to be overcome and the exact role of MIRP in the management of pancreatic necrosis has yet to be defined.

Laparoscopic vs open hepatic resection: a comparative study

BACKGROUND

Although the feasibility of minor laparoscopic liver resections (LLR) has been demonstrated, data comparing the open vs the laparoscopic approach to liver resection are lacking.

METHODS

We compared 30 LLR with 30 open liver resections (OLR) in a pair-matched analysis. The indications for resection were malignant disease in 47% of the LLR and 83% of the OLR. The average size of the lesions was 42 mm for LLR and 41 mm for OLR. Five wedge resections, 12 segmentectomies, and 13 bisegmentectomies were performed in each group.

RESULTS

The conversion rate for LLR was nil. The mean operative time was 148 min for LLR and 142 min for OLR. Mean blood loss was minimal in the LLR group (320 vs 479 ml; p < 0.05). Postoperative complications occurred in 6.6% of the patients in each group; there were no deaths. The mean postoperative hospital stay was shorter for LLR patients (6.4 vs 8.7 days; p < 0.05). In tumors, the resection margin was <1 cm in 43% of the LLR patients and 40% of the OLR patients ( p = NS).

CONCLUSIONS

Minor LLR of the anterior segments has the same rates of mortality and morbidity as OLR. However, the laparoscopic approach reduces blood loss and postoperative hospital stay.

Evaluation of Gd-enhancement in brain MR of multiple sclerosis: image subtraction with and without magnetization transfer

The aim of our study was to test the possibility of using image subtraction in detecting enhancing lesions in brain MR scans with and without magnetization transfer (MT) in multiple sclerosis (MS). Ten MS patients underwent 1.5-T MR imaging of the brain with spin-echo T1-weighted sequences with and without MT, repeated after 0.1 mmol/kg of an usual two-compartment paramagnetic contrast agent (Gadoteridol, Gd-HP-DO3A). Precontrast images were subtracted from postcontrast. Enhancing lesions were counted on the postcontrast images only (post-Gd), comparing pre- and postcontrast images by direct visual control (pre/post-Gd), and on the subtracted images (SI) only. Without MT, 36 enhancing lesions were counted on post-Gd, 36 on pre/post-Gd, and 59 on SI; using MT, 69, 52, and 50, respectively. Significant differences were found for pre/post-Gd without MT vs SI without MT ( p=0.028) and vs pre/post-Gd with MT ( p=0.012) as well as for pre/post-Gd with MT vs post-Gd with MT ( p=0.028). With pre/post-Gd, MT allowed the detection of 1.6 enhancing lesions per patient more than without MT. Whereas the SI without MT allow the detection of an increased number of enhancing lesions, SI with MT do not. An off-site final assessment allowed calculation of sensitivity and positive predictive value as follows: without MT were 63 and 94% (post-Gd), 67 and 100% (pre/post-Gd), 96 and 88% (SI); and with MT were 93 and 73% (post-Gd), 96 and 100% (pre/post-Gd), 91 and 98% (SI), respectively. Thus, SI seem to increase the sensitivity without MT; moreover, they could be used to correct the pseudoenhancement that impair post-Gd images with MT.

[Brain magnetic resonance with magnetization transfer in multiple sclerosis. Lesion hyperintensity before and after intravenous gadolinium administration]

PURPOSE

To evaluate lesion contrast enhancement in brain magnetic resonance (MR) images with and without magnetization transfer pulse (MT) in patients affected with multiple sclerosis (MS).

MATERIAL AND METHODS

Ten patients affected with relapsing-remitting MS underwent a 1.5-T (Magnetom Vision, Siemens) MR examination with T1-weighted spin-echo sequences without MT (TR/TE = 630/14 ms) and with MT (840/14 ms) using the following common parameters: 21 para-axial slices (thickness 5 mm, 10% gap); matrix 256 x 256; field of view 25 cm (rectangular 5/8); 2 excitations. The postcontrast sequences with and without MT were acquired in a randomized order, starting 5 minutes after the intravenous injection of 0.1 mmol/kg Gadoteridol (ProHance, Bracco). The images were blindly evaluated in four separate sessions: only the postcontrast images with MT (post-Gd with MT); only the postcontrast images without MT (post-Gd without MT); comparing the pre- and postcontrast images with MT (pre/post-Gd with MT); comparing the pre- and postcontrast images without MT (pre/post-Gd without MT). The number of hyperintense areas referred to contrast enhancement and the evaluation time were measured for each session. The Wilcoxon test was used for statistical analysis.

RESULTS

The number of areas referred to lesion contrast enhancement per patient were as follows: post-Gd with MT, 6.9 +/- 6.8 (mean +/- standard deviation) (range 1-24); post-Gd without MT, 3.6 +/- 4.3 (0-14); pre/post-Gd with MT, 5.2 +/- 6.1 (1-21); pre/post-Gd without MT, 3.6 +/- 4.9 (0-16). A nonsignificant difference was found for the comparison between post-Gd without MT and pre/post-Gd without MT while significant differences were found between post-Gd with MT and pre/post-Gd with MT (p = .028), pre/post-Gd without MT and pre/post-Gd with MT (p = .012), as well as between post-Gd without and post-Gd with MT (p = .008). The mean evaluation time for the different sessions was always less than a minute, ranging from 33 seconds for pre/post-Gd without MT to 51 seconds for post-Gd with MT.

CONCLUSIONS

The postcontrast sequence obtained with the MT pulse detects more active lesions than the postcontrast sequence without MT. However, the comparison with the plain images with the MT pulse is mandatory to exclude pseudoenhancement foci, i.e. hyperintense areas already present in the precontrast images with the MT pulse, without disruption of the blood-brain barrier. The post-Gd without MT sequence needs not be compared with the precontrast images without MT. Differences in evaluation time are practically negligible.

Do magnesium ions influence barium mucosal coating of the large bowel?

The aim of the present study was to verify whether the presence of magnesium in the colon lumen at the time of the double-contrast barium enema (DCBE) examination changes the quality of barium mucosal coating. The two members of 38 pairs of patients undergoing DCBE with a standardised technique were randomly subjected to bowel preparation with sennosides and magnesium sulphate, or sennosides and sodium sulphate. Mucosal coating, residual fluid and colon cleansing were assessed independently by three radiologists. The null hypothesis was tested by means of Wilcoxon's signed-rank test. Barium mucosal coating was judged to be better in the members to whom magnesium sulphate was administered (p = 0.0007). There was no difference in the amount of residual fluids (p = 0.3198). Colon cleansing was judged to be better in the members to whom sodium sulphate was administered (p = 0.0166). These results demonstrate, in a simple way, that magnesium ions increase barium coating of the colon mucosa in vivo. The underlying mechanisms (increase in viscosity of barium suspension through water subtraction owing to the hydrophilism of magnesium ions, or interactions with the polysaccharide additives) need further investigation. A first clinical application could be the integration of magnesium ions in a newly designed isotonic electrolyte solution containing polyethylene glycol for the oral colon wash-out.

[The surgical treatment of lung metastases. The prognostic factors and the indications for the surgical approach]

BACKGROUND

After the liver, the lungs represent the most frequent site of metastasis from primary tumours. Surgical treatment of lung secondary neoplasms leads to a significant improvement in survival.

METHODS

Between 1960-1997, 178 patients with lung metastases underwent surgery at the Thoracic Surgery Department of Turin University in a total of 193 operations. A retrospective study was made in order to identify the prognostic factors which influenced final survival in this population.

RESULTS

Overall survival was 47% after 2 years and 20% after five years. Prognosis was not influenced by the size of metastases, the type of surgery, adjuvant therapy and the number of operations on the same patient. On the other hand, useful prognostic factors were found to be the histological type of the primary tumour, the original site of the neoplasm, the number of metastases and, above all, the disease-free interval (DFI).

CONCLUSIONS

Lung metastasectomy is an important therapeutic aid in selected patients, whereas the preoperative evaluation of the above prognostic factors enables a reasonably precise prognosis to be made in most patients.

Bowel preparation for the double-contrast barium enema: how to maintain coating with cleansing?

AIM

Poor mucosal coating, due to excess of fluid in the colon lumen, is a problem when the oral lavage method (4 litres of an iso-osmotic saline solution containing polyethylene glycol) is used as a preparation for double-contrast barium enema. Our aim was to assess the value of prior administration of sennosides to obtain a clean colon with a reduced volume of polyethylene glycol (PEG)-saline solution, but maintaining good mucosal coating.

MATERIALS AND METHODS

After a 2-day low-residue diet, three different oral preparations were compared: (i) 4 litres of a PEG-saline solution (SELG) and 15 mg of bisacodyl (116 patients, SELG-4 group); (ii) 156 mg of sennosides, 15 g of magnesium sulphate, and 2 litres of water (116 patients, SennMg group); (iii) 156mg of sennosides and 2 litres of SELG (116 patients, SennSELG group). Compliance, complaints, cleansing, mucosal coating, and fluid retention were evaluated.

RESULTS

Compliance was > 94% in every group. A higher percentage of mild nausea was observed in SELG-4 group, of mild abdominal cramping in SennMg group, of substantial abdominal cramping in SennSELG group (P < 0.02). Cleansing was better in SennSELG than in both the SELG-4 (P = 0.0003) and SennMg (P = 0.0353) group. Mucosal coating was better in SennMg than both SELG-4 (P = 0.0034) and SennSELG (P < 0.0001) group. There was more residual fluid in the SennSELG group than both in SELG-4 (P = 0.0029) and SennMg (P = 0.0059) group.

CONCLUSION

For colon cleansing, the combination of sennosides and PEG-saline solution was better than either the 4 litre PEG protocol or the combination of sennosides and magnesium sulphate. For mucosal coating, the protocol combining sennosides and magnesium sulphate was more effective than either protocols using the PEG-saline solution. This may be due to the interaction of residual magnesium ions in the colon lumen with the barium suspension.

A new magnesium-containing PEG-electrolyte solution for the oral lavage of the colon

AIM

The aim of the present study was to verify whether the addition of magnesium ions to an electrolyte solution containing polyethylene glycol (PEG-ELS) for the oral lavage of the colon increases barium mucosal coating at the time of double-contrast barium enema (DCBE) examination.

MATERIALS AND METHODS

The two patients from 60 pairs of patients undergoing DCBE with a standardized technique were randomly subjected to bowel preparation with sennosides and an isotonic PEG-ELS (SELG, Promefarm, Italy), or sennosides and a modified isotonic SELG preparation to which 7.5 g/l of magnesium sulphate were added. Mucosal coating, residual fluid and colon cleansing were assessed independently by three radiologists. The null hypothesis was tested by means of Wilcoxon's signed-rank test.

RESULTS

Barium mucosal coating was judged to be significantly better in the SELG-Mg members (P<0.0001). The amount of residual fluid was significantly lower in SELG-Mg members (P<0.0001). There was no difference in colon cleansing (P = 0.690). These results demonstrate, in a simple way, that magnesium ions increase barium coating of the colon mucosa in vivo. The underlying mechanism seems to be the increase in viscosity of barium suspension by free water subtraction owing to the hydrophilia of magnesium ions.

CONCLUSION

The integration of magnesium in a newly designed isotonic PEG-ELS could be the correcting factor for the poor barium mucosal coating that normal solutions for the oral colon lavage induce.

[Vascular endothelial growth factor. From basic research to clinical application]

There is increasing evidence to support the concept that growth and metastasis of solid tumors, including those of gastrointestinal tract, is facilitated by neoangiogenesis. Vascular Endothelial Growth Factor (VEGF) is one of the most powerful known inducer of endothelial cell growth. Therefore, VEGF is likely to contribute to tumor growth by promoting angiogenesis and stroma formation both directly, through its neovascularization inducing activity, and indirectly, by increasing vascular permeability. In addition, VEGF facilitates tumor diffusion favouring metastatic spread of cancer cells. In view of these implications, it is important to understand the physiopathological role played by this factor. In this review the authors present the accumulating body of data on the biological and functional properties of VEGF, paying special reference to new evidence on its contribution in tumor immune escape, through a marked inhibition of differentiation and activity of the professional antigen presenting cells (APC), namely dendritic cells (DC). As the molecular and cellular events that underlie the functional role of VEGF in tumor angiogenesis and immune suppression become better defined, rational pharmacological and/or gene therapies can be derived in order to treat those neoplasms, such as pancreatic adenocarcinoma, not well amenable to chemo- and radiotherapy or immunotherapy.

Modulation of rat liver protein kinase C during "in vivo" CC14-induced oxidative stress

Rat intoxication with a single dose of the hepatotoxin carbon tetrachloride induces a significant modification of liver protein kinase C total activity which depends on the degree of the intrahepatocyte oxidative unbalance provoked by various concentrations of the haloalkane. Low carbon tetrachloride amounts stimulate total protein kinase C activity, while one order of magnitude higher amounts exert strong enzyme inhibition. The latter effect is due to an early inactivation followed with progress of time by a proteolytic degradation of the enzyme. A pathological recruitment of the calcium-dependent protein kinase C regulatory enzymes calpain and calpastatin appears responsible for protein kinase C loss. The prolonged excess of cytosolic calcium which characterizes the single high dose carbon tetrachloride poisoning also leads to inactivation of calpain II and calpastatin in a time-dependent manner.