Biomedical subjects

P G Boelens

Publications and source records attributed to P G Boelens.

10 recordsLinked to original sources

PubMed2006

[Perioperative nutrition].

Illness is associated with involuntary weight loss, which is often the result of malnutrition. The undernourished surgical patient runs a higher risk of postoperative morbidity and mortality. For this reason, perioperative nutrition is an important part of a patient's therapy. Supplying substrates for wound healing and maintaining existing organic structures are the major goals of nutrition. It is recommended that extremely malnourished patients be fed at least 7 days prior to surgery. It would seem sensible to give a carbohydrate-rich beverage up to 2 hours before surgery, both to decrease preoperative anxiety and to reduce postoperative insulin resistance. The Dutch tradition of fasting patients before surgery is difficult to defend any longer because this policy impairs patients' state of health as a result of which they are not optimally prepared for the surgical induced stress response. The postoperative recovery of all surgical patients can be improved by an early postoperative start of enteric nutrition. When the enteric administration of food turns out to be impossible, total parenteral nutrition can be given to bridge a long period without food.

Humans↗

PubMed2004

Primary immune response to keyhole limpet haemocyanin following trauma in relation to low plasma glutamine.

Severe trauma can lead to a compromised immune response, thereby increasing susceptibility to infections. Here we will study to what extent these early changes in the immune status upon trauma affect a primary immune response to keyhole limpet haemocyanin (KLH). Because glutamine is the preferred respiratory substrate for immune competent cells and known to be depleted after trauma, we studied the immune status and the primary sensitization in relation to the glutamine plasma concentration in a group of severe trauma patients [injury severity score (ISS) >17]. Trauma patients (n = 31) were sensitized with KLH within 12 h after trauma; plasma glutamine concentrations and immune parameters were determined, after which KLH-specific immune responsiveness was evaluated on days 9 and 14. Low plasma glutamine concentrations were found after trauma. Significantly elevated numbers of granulocytes and CD14-positive leucocytes were found, whereas the HLA-DR expression on CD14-positive cells was significantly lower in trauma patients than in healthy controls. Trauma did not change the in vitro proliferative capacity of lymphocytes when cultured with glutamine; however, when lymphocytes were cultured without glutamine, trauma resulted in lower proliferation than healthy controls. Phytohaemagglutinin-(PHA)-induced interferon (IFN)-gamma and interleukin (IL)-10 production was significantly lower after trauma, whereas IL-4 production was not affected. KLH sensitization following trauma resulted in poor skin test reactivity and low in vitro KLH-induced lymphocyte proliferation compared to controls. In contrast, the development of anti-KLH IgM, IgG, IgA, IgG1, IgG2, IgG3 and IgG4 production on days 9 and 14 following trauma was not different from that in healthy controls. Major trauma was associated with a reduced cell-mediated immune response, correlating with low plasma glutamine concentrations, while no effects of trauma were found on the development of a primary humoral immune response.

Adolescent↗

PubMed2001

Low arginine plasma levels do not aggravate renal blood flow after experimental renal ischaemia/reperfusion.

BACKGROUND: Ischaemic renal dysfunction is present in many clinical settings, including cardiovascular surgery. Renal hypoperfusion seems to be the most important pathophysiologic mechanism. Arginine plasma levels are rate limiting for NO synthesis, and low arginine plasma levels are seen after major vascular surgery. OBJECTIVE: to establish the effects of low arginine plasma levels on renal blood flow after renal ischaemia/reperfusion. DESIGN: Wistar rats were used in this unilateral renal ischaemia/reperfusion model. After 70 min of ischaemia, the kidney was reperfused for 150 min. Arginase infusion was used to lower arginine plasma levels. Blood flow measurement was performed at the end of the experiment using radiolabelled microspheres. Additional experiments were performed for histopathology. RESULTS: Arginase efficiently decreased arginine plasma levels to about 50% of normal. There was a lower blood flow in the ischaemic kidney than the contralateral (non-ischaemic) kidney. Lowering arginine plasma levels did not reduce renal blood flow in the ischaemic kidney. Renal histopathology was not influenced by lowered arginine plasma levels. CONCLUSIONS: Lowering arginine plasma levels did not affect blood flow or histology following renal ischaemia and reperfusion.

Animals↗

PubMed2001

Flavonoids: a review of probable mechanisms of action and potential applications.

The aim of this review, a summary of the putative biological actions of flavonoids, was to obtain a further understanding of the reported beneficial health effects of these substances. Flavonoids occur naturally in fruit, vegetables, and beverages such as tea and wine. Research in the field of flavonoids has increased since the discovery of the French paradox,ie, the low cardiovascular mortality rate observed in Mediterranean populations in association with red wine consumption and a high saturated fat intake. Several other potential beneficial properties of flavonoids have since been ascertained. We review the different groups of known flavonoids, the probable mechanisms by which they act, and the potential clinical applications of these fascinating natural substances.

Antioxidants↗

PubMed2001

Glutamine alimentation in catabolic state.

Glutamine should be reclassified as a conditionally essential amino acid in the catabolic state because the body's glutamine expenditures exceed synthesis and low glutamine levels in plasma are associated with poor clinical outcome. After severe stress, several amino acids are mobilized from muscle tissue to supply energy and substrate to the host. Glutamine is one of the most important amino acids that provide this function. Glutamine acts as the preferred respiratory fuel for lymphocytes, hepatocytes and intestinal mucosal cells and is metabolized in the gut to citrulline, ammonium and other amino acids. Low concentrations of glutamine in plasma reflect reduced stores in muscle and this reduced availability of glutamine in the catabolic state seems to correlate with increased morbidity and mortality. Adding glutamine to the nutrition of clinical patients, enterally or parenterally, may reduce morbidity. Several excellent clinical trials have been performed to prove efficacy and feasibility of the use of glutamine supplementation in parenteral and enteral nutrition. The increased intake of glutamine has resulted in lower septic morbidity in certain critically ill patient populations. This review will focus on the efficacy and the importance of glutamine supplementation in diverse catabolic states.

Acquired Immunodeficiency Syndrome↗

PubMed2001

Coagulopathy following major liver resection: the effect of rBPI21 and the role of decreased synthesis of regulating proteins by the liver.

This prospective study investigated the role of reduced hepatic synthesis of regulating proteins in coagulopathy after partial hepatectomy (PH) compared with major abdominal surgery (MAS) without involvement of the liver. Furthermore, we studied the effect of rBPI21, an endotoxin-neutralizing agent, on coagulopathy after PH was studied. Compared with MAS, PH resulted in significantly elevated levels of thrombin-antithrombin-III and plasmin-alpha2-antiplasmin complexes. Levels of antithrombin-3, alpha2-antiplasmin, fibrinogen, plasminogen, alpha2-macroglobulin (alpha2-M), and C1-inhibitor remained lower following PH. Treatment with rBPI21 led to significantly lower levels of tissue-type plasminogen activator (t-PA). Post-operative disseminated intravascular coagulation (DIC) was associated with significantly higher bilirubin and t-PA plasma levels and significantly lower levels of alpha2-M. This study indicates that PH induced hepatic failure results in decreased synthesis of hepatic regulating plasma proteins and subsequent activation of coagulation and fibrinolysis. Prevention of t-PA release by rBPI21 may have important clinical implications. Decreased availability of alpha2-M may be a factor in post-operative DIC.

Abdomen↗

PubMed2001

Perioperative treatment with bactericidal/permeability-increasing protein (rBPI21) in major liver surgery: a concise summary.

INTRODUCTION: Major hepatic resections are still associated with considerable morbidity. Gut-derived bacteria and bacterial endotoxin are considered to play a central role in the pathophysiology of complications. Experimental studies suggest that bactericidal/permeability-increasing protein (BPI), which has both antibacterial and endotoxin-neutralising properties, can reduce postoperative complications. MATERIAL AND METHODS: A phase II, double-blind, placebo-controlled, multicentre, dose escalation trial was conducted in patients undergoing major liver resection, and clinical outcome, infectious complications, plasma amino acid patterns, coagulation and fibrinolytic cascade systems and neutrophil functions were compared between the two treatment groups and an extra group of patients undergoing major abdominal non-hepatic surgery. RESULTS: Drug administration in this patient group was safe, and resulted in a significant reduction of infectious complications. Furthermore, beneficial effects were found in the postoperative amino acid ratio and fibrinolytic cascades, and rBPI21 preserved leukocyte functions. CONCLUSION: Administration of rBPI21 in patients undergoing major liver resection is well tolerated and results in improvement of both clinical and biochemical parameters.

Adult↗

PubMed2000

Interleukin-10 appearance following thoraco-abdominal and abdominal aortic aneurysm repair is associated with the duration of visceral ischaemia.

OBJECTIVES: to evaluate the plasma IL-10 levels during elective operative repair of thoraco-abdominal and abdominal aortic aneurysm repair. To study whether IL-10 plasma levels are associated with the duration of cross-clamping (ischaemia) and clinical outcome. MATERIALS: fifteen consecutive patients undergoing surgery for TAAA and 10 consecutive patients undergoing surgical repair of AAA were included. METHODS: plasma concentrations of IL-10 were measured by ELISA technique. Clinical outcome of the TAAA patients was prospectively analysed. RESULTS: during aortic clamping IL-10 was produced in both populations. The plasma IL-10 peak (934+/-172 pg/ml) of the TAAA group was seen at 4 h after declamping and remained detectable after 48 h. The plasma IL-10 peak (212+/-32 pg/ml) of the AAA group was seen 30 min after declamping and fell to undetectable levels by 24 h. These data show that the peak IL-10 plasma levels in TAAA repair are significantly (p<0.05) higher compared to the peak IL-10 plasma levels as seen during AAA repair. A positive correlation was seen between cross-clamping and peak plasma IL-10 and organ dysfunction. CONCLUSIONS: IL-10 plasma concentrations appear higher, later and are longer detectable in patients undergoing TAAA. Correlations were seen with duration of cross-clamping and MSOD.

Aortic Aneurysm, Abdominal↗

PubMedDate not supplied

Aortic aneurysm repair is associated with a lower inflammatory response compared with surgery for inflammatory bowel disease.

BACKGROUND: Since the plasma cytokine profile reflects the body's inflammatory response to injury, this study was designed to prospectively observe the plasma cytokine levels in response to the degree of different sorts of abdominal surgical trauma. METHODS: Plasma levels of TNF-alpha, type I TNF receptor (p55), type II TNF receptor (p75), IL-6, IL-8, IL-10, phospholipase A(2) (PLA(2)), and haptoglobin were measured peri-operatively in patients undergoing bowel resection for inflammatory bowel disease or diverticulitis (IBD) (n = 9), elective repair of abdominal aortic aneurysm (AAA) (n = 9), or laparoscopic cholecystectomy (lap chole) (n = 9). RESULTS: The IBD patients showed a significant (p < 0.05) post-operative elevation in plasma IL-6, p55, p75, and PLA(2) levels, but no significant change in TNF-alpha, IL-8, IL-10 or haptoglobin levels. The AAA patients had a significant post-operative rise in IL-10 levels and a significant decrease in plasma haptoglobin levels, but no significant change of TNF-alpha, IL-6, IL-8, p55, p75, or PLA(2) concentrations. The lap chole patients demonstrated no significant change in any of these parameters. CONCLUSION: These data show that IL-6, IL-10, p55, and p75 are markers to measure the degree of inflammatory stress associated with abdominal operative procedures and demonstrate the relative lack of a cytokine response to laparoscopic cholecystectomy.

Adult↗

PubMedDate not supplied

Preoperative fasting: an outdated concept?

Recent studies have shown that fasting during the preoperative period for elective surgery induces a metabolic state that seems unfavorable for patients. Results from animal studies indicate that rapid depletion of liver glycogen before surgery leads to mobilization of muscle glycogen after surgery, in turn leading to reduced muscle strength. Depletion of liver glycogen also influences the function of the mononuclear phagocytic system (MPS), which is located predominantly in the liver. The MPS is essential in restricting endotoxin, which may translocate from the gut. In addition, surgery per se puts a substantial physical strain on the patient, and fasting may adversely affect the metabolic response to surgery. This paper presents experimental and clinical data that, when combined together, prove that fasting before surgery has adverse consequences for the patient.

Animals↗