Biomedical subjects

Klaske van Norren

Publications and source records attributed to Klaske van Norren.

3 recordsLinked to original sources

PubMedDate not supplied

Preoperative feeding preserves heart function and decreases oxidative injury in rats.

OBJECTIVE: The nutritional status of a patient has been implicated as an important factor in the development of postoperative complications. Fasting before an operation may have detrimental effects on the metabolic state. We hypothesized that there was a positive correlation between preoperative nutritional status and postoperative organ function. METHODS: Preoperative feeding was compared with fasting with respect to effects on organ function and biochemical parameters in an animal model of extensive large abdominal surgery. Male Wistar rats were fed ad libitum or fasted for 16 h, after which the arteria mesenterica superior was clamped for 60 min followed by 180 min of reperfusion. RESULTS: After the ischemic period, heart function was significantly better in animals that were fed ad libitum than in fasted animals. Moreover, after intestinal ischemia and reperfusion, fed rats showed significantly higher levels of intestinal adenosine triphosphate and a significantly higher malondialdehyde concentration in the intestine and lung than did fasted rats. The ratio of adenosine triphosphate to adenosine diphosphate in the liver, an indicator of energy status, in fed rats was similar to that in a sham group, whereas fasted animals showed a significantly lower value. CONCLUSIONS: Preoperative nutrition in contrast to fasting may attenuate ischemia/reperfusion-induced injury and preserve organ function in the rat.

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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Preoperative fasting: an outdated concept?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.

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PubMedDate not supplied

Effects of preoperative flavonoid supplementation on different organ functions in rats.

BACKGROUND: Previously it has been reported that preoperative feeding preserves heart function in rats after intestinal ischemia-reperfusion. To further improve postoperative organ function, bioactive nutrition compounds were selected in vitro against the xanthine oxidase radical cascade, an enzyme suggested to play a key role in the induction of single- or multiple-organ dysfunction. METHODS: Flavonoids were selected in vitro for their capacity to (1) inhibit xanthine oxidase, (2) scavenge superoxide, and (3) scavenge peroxylradicals. The most bioactive flavonoids were added to the preoperative nutrition to study their effect on postintestinal ischemia-reperfusion organ function. RESULTS: A combination of flavonoids selected on basis of effective flavonoid xanthine oxidase inhibition and superoxide scavenging resulted in increased superoxide scavenging. In vivo, the selected flavonoid mixture significantly lowered postischemic intestinal apoptosis and intestinal oxidative stress indicated by malondialdehyde concentration when compared with ischemia-reperfusion fasted and sham-fasted animals. Moreover, this flavonoid mixture significantly lowered plasma creatinine and urea concentration, both indicating a better postoperative kidney function. Furthermore, oxidative stress measured as this flavonoid mixture when compared with control significantly lowered plasma malondialdehyde concentration in fed rats. CONCLUSIONS: Coadministration of bioactive flavonoid mixture to preoperative nutrition, in contrast to fasting, attenuates ischemia-reperfusion injury by preserving kidney function in the rat and decreasing apoptosis in the intestine.

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