[Melanoma of the skin: excision policy and pathology report writing in the 'Integraal Kankercentrum Zuid' region is in accordance with the guideline in slightly more than half of the patients]

OBJECTIVE

To determine the extent to which the guidelines for cutaneous melanoma had been implemented in the diagnostic and treatment approach of general hospitals.

DESIGN

Retrospective, descriptive.

METHOD

Patients were selected via the cancer registration system of the 'Integraal Kankercentrum Zuid' (Integral Cancer Centre South, the Netherlands). They were submitted through the pathology laboratory by 1 of the 16 general hospitals in the region. Data was collected from the pathology (PA) reports of the 573 patients for whom a cutaneous melanoma was diagnosed in 1988, 1993 and 1997. The treatment policy and the PA reports were compared with the recommendations in the guidelines concerned and the revised versions of these published in 1985, 1990 and 1997. The patients studied were 212 men (37%) and 361 women (63%) with an average age of 51 years (range 13-96).

RESULTS

A diagnostic excision was performed in 485/573 patients (85%). Invasiveness was assessed in 99% of the preparations; in 14% a melanoma was encountered in situ. Invasive melanomas were less often seen in the head and neck region than on the trunk or limb. Thickness of the tumour was not determined in 8% of all 493 invasive tumours and in 19% the pathology report did not state whether the diagnostic biopsy was performed radically. In accordance with the guidelines, diagnostic excision biopsy was first performed in 59% of patients with a subsequent re-excision if necessary; 77% of the PA reports satisfied the fundamental recommendations from the guidelines. For 55% of the patients the diagnostic and therapeutic procedures as well as the pathology report were completed in accordance with the guideline recommendations. Modest improvement occurred over time.

CONCLUSION

The excision and re-excision policies as well as the pathology report writing concurred with the recommendations in the consensus for cutaneous melanoma in slightly more than half of the patients who were diagnosed within the IKZ region in the years 1988, 1993 and 1997.

Upper gastrointestinal bleeding: an ammoniagenic and catabolic event due to the total absence of isoleucine in the haemoglobin molecule

Upper gastrointestinal bleeding causes increased urea concentrations in patients with normal liver function and high ammonia concentrations in patients with impaired liver function. This ammoniagenesis may precipitate encephalopathy. The haemoglobin molecule is unique because it lacks the essential amino acid isoleucine and has high amounts of leucine and valine. Upper gastrointestinal bleeding therefore presents the gut with protein of very low biologic value, which may be the stimulus to induce a cascade of events culminating in net catabolism. This may influence the function of rapidly dividing cells and short half-life proteins. We hypothesize that, following a variceal bleed in a cirrhotic patient, the lack of isoleucine in blood protein is the cause of the exaggerated ammoniagenesis and catabolism. We propose that intravenous administration of isoleucine may serve as a simple therapeutic that transforms blood protein in a balanced protein, resulting in only a short-lived rise in ammonia and urea production, and preventing interference with protein synthesis.

[Uremia after hemorrhages in the upper digestive tract]

Haemorrhages in the upper GI tract may lead to severe uraemia and, in patients with liver failure, to hyperammonaemia. The cause of this is not yet sufficiently clear. Recently we observed a decrease in arterial isoleucine levels after intragastric blood administration in pigs. This contrasted with elevated levels of most other amino acids, ammonia and urea. After an isonitrogenous control meal in these pigs all amino acids including isoleucine increased, and urea increased to a lesser extent, suggesting a relationship between the arterial isoleucine decrease and uraemia after gastrointestinal (GI) haemorrhage. Analysis of blood protein showed a complete absence of the essential amino acid isoleucine, making it a protein of low biological value. In additional porcine experiments, uraemia after intragastric blood administration could be prevented by simultaneous intravenous isoleucine administration. This led to the hypothesis that there was a causal relationship between the absence of isoleucine in blood protein and the uraemia and hyperammonaemia observed after GI bleeding. Similar results were seen in patients with intact and with impaired liver functions. These results support the hypothesis that the absence of isoleucine in blood protein causes decreased plasma and tissue isoleucine levels after GI haemorrhage. This might inhibit protein synthesis, and may contribute to uraemia and hyperammonaemia in patients with normal and impaired liver function, respectively. Intravenous isoleucine administration after GI haemorrhage could be beneficial.

Decreased plasma isoleucine concentrations after upper gastrointestinal haemorrhage in humans

BACKGROUND

A decrease in arterial isoleucine values after intragastric blood administration in pigs has been observed. This contrasted with increased values of most other amino acids, ammonia, and urea. After an isonitrogenous control meal in these pigs all amino acids including isoleucine increased, and urea increased to a lesser extent, suggesting a relation between the arterial isoleucine decrease and uraemia after gastrointestinal haemorrhage.

METHODS

To extend these findings to humans, plasma amino acids were determined after gastrointestinal haemorrhage in patients with peptic ulcers (n = 9) or oesophageal varices induced by liver cirrhosis (n = 4) and compared with preoperative patients (n = 106).

RESULTS

After gastrointestinal haemorrhage, isoleucine decreased in all patients by more than 60% and normalised within 48 hours. Most other amino acids increased and also normalised within 48 hours. Uraemia occurred in both groups, hyperammonaemia was seen in patients with liver cirrhosis.

CONCLUSIONS

These results confirm previous findings in animals and healthy volunteers that plasma isoleucine decreases after simulated upper gastrointestinal haemorrhage. This supports the hypothesis that the absence of isoleucine in blood protein causes decreased plasma isoleucine values after gastrointestinal haemorrhage, and may be a contributory factor to uraemia and hyperammonaemia in patients with normal and impaired liver function, respectively. Intravenous isoleucine administration after gastrointestinal haemorrhage could be beneficial and will be the subject of further research.

Modification of the effects of blood on amino acid metabolism by intravenous isoleucine

The absence of isoleucine in the hemoglobin molecule has been suggested to contribute to increased urea production after a blood meal. To unravel the underlying mechanism, the effects of isoleucine infusion after blood ingestion in the healthy pig were studied. The isoleucine dose was chosen to induce an arterial isoleucine increase comparable to those observed for leucine or valine after blood ingestion. For the experiments, 10 female overnight-fasted pigs (20-25 kg) received 250 mL bovine erythrocytes intragastrically 1 week after catheter implantation for measuring hepatic, splanchnic, portal-drained viscera, and hindquarter fluxes of amino acids, urea, and ammonia. After the administration of erythrocytes, isoleucine or saline was administered i.v. for 6 hours. The data obtained show that the increase in arterial levels of urea and almost all amino acids was significantly greater in the control group (P less than 0.001) than in the isoleucine group. The net efflux of nearly all amino acids by the portal-drained viscera increased significantly less (P less than 0.001) in the isoleucine group. The liver uptake of amino acids increased after the blood meal, but the difference was not significant except for glutamine (P less than 0.001). Hindquarter amino acid net influx increased marginally. Splanchnic urea production increased more in the control group than in the isoleucine group (P less than 0.05). The data strongly suggest that i.v. administration of isoleucine enhanced the biological value of a blood meal, possibly by promoting amino acid retention in the portal drained viscera.

Effects of infusion of branched chain amino-acids enriched TPN solutions on plasma amino-acid profiles in sepsis and trauma patients

Total parenteral nutrition with branched chain amino-acids enriched solutions has been advocated in patients with sepsis and stress because of favourable effects on nitrogen balance, protein synthesis and immune competence. The rationale for the use of BCAA-enriched solutions is based on their potential to correct the plasma amino-acid imbalances seen in these patients. In a 7-day prospective randomised study we investigated the effects on plasma amino-acid concentrations of a standard amino-acid solution (15.6% BCAA) and a branched chain amino-acid enriched solution (50.2% BCAA) in 101 parenterally fed patients with carefully assessed sepsis and/or stress scores. The infusion of the BCAA-enriched solution led to an imbalance of the essential plasma amino-acids. The branched chain amino-acids valine, leucine and isoleucine increased significantly while the non-BCAA essential amino-acids decreased significantly. In the standard solution the non-BCAA-essential amino-acids increased significantly with a slow and insignificant rise in the levels of the branched chain amino-acids. We conclude that infusion of a BCAA enriched TPN formulation induced amino-acid profile derangements that can be considered ill-suited to the achievement of anti-catabolic effects.

Effect of branched chain amino acid enrichment of total parenteral nutrition on nitrogen sparing and clinical outcome of sepsis and trauma: a prospective randomized double blind trial

Administration of extra branched chain amino acids (BCAA) has been associated with a nitrogen sparing effect in septic and traumatized patients. Whether nitrogen sparing is associated with decreased morbidity and mortality rates is unknown. We therefore undertook a prospective, randomized, double blind trial investigating the effects of BCAA enrichment of a total parenteral nutrition (TPN) regimen on nitrogen balance, 3-methylhistidine excretion, morbidity as evidenced by disturbances in organ function, severity of sepsis and mortality. One hundred and one patients entered the study; 52 received a standard TPN solution and 49 a BCAA-enriched solution. Both groups received 30 kcal kg-1 body-weight, 15 per cent fat calories and 0.17 g nitrogen kg-1 body-weight. In the BCAA-enriched group, patients received 0.56 g BCAA kg-1 body-weight (50.2 per cent BCAA). Standard group patients received 0.18 g BCAA kg-1 body-weight (15.6 per cent BCAA). Nitrogen balances and 3-methylhistidine excretion were not significantly different between groups. Although morbidity scores tended to decrease during the study no difference was observed between groups. Mortality (early or late), sepsis or stress-related, did not differ significantly between groups. We were not able to confirm the reported beneficial effects of BCAA-enriched TPN solutions for use in septic and traumatized patients.

Is increased ammonia liberation after bleeding in the digestive tract the consequence of complete absence of isoleucine in hemoglobin? A study in pigs

A variable protein-induced toxicity has been reported in liver disease. The aim of this study was to establish the cause of increased ammonia liberation in the gut after intraluminal bleeding. Therefore, blood was sampled from catheterized piglets [20 +/- 0.8 kg (means +/- S.E.); n = 10] to determine ammonia, urea and amino acid levels before and 1, 2, 3 and 6 hr after a standard pig meal (750 gm, 12% protein). After 1 week, this procedure was repeated after ingestion of an isonitrogenous amount of bovine whole blood (400 ml). In a second series of experiments, the same procedures were performed after ingestion of plasma, whole blood, erythrocytes and feed. Electromagnetically measured total intestinal, small and large bowel flow was not significantly influenced by the type of meal ingested. Portal ammonia release was significantly increased 2-fold after a blood meal, whereas intestinal glutamine utilization did not increase. Plasma urea levels were increased 200 to 300% after whole blood and erythrocytes, whereas after ingestion of plasma, urea levels were similar to values in controls. Glutamine utilization was not different among the various groups and occurred predominantly in the small bowel. In the fasted state, small bowel glutamine utilization paralleled ammonia production. In the fed state, this equimolar relationship could not be assessed because luminal glutamine utilization could not be determined. Isoleucine levels decreased to 25% of fasting levels. Analysis of blood constituents revealed a complete lack of isoleucine in the hemoglobin molecule. Net total alpha-amino-nitrogen absorption was doubled after a blood meal.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma-amino acid profiles in sepsis and stress

Sepsis has been associated with specific plasma amino acid patterns. Sixty-five patients were prospectively investigated as to whether these patterns are indeed sepsis specific, or specific for metabolic stress without concomitant sepsis, or associated with the presence of organ failure. Virtually all aminoacid levels were decreased by 10-30% (p less than 0.05), whereas cystine and phenylalanine were significantly elevated. These changes were more pronounced in severe sepsis. Organ failure was not associated with significantly altered amino acid profiles. No differences were found between sepsis and stress without signs of sepsis. In addition, imminent death was not associated with aberrant amino acid profiles. We conclude that sepsis and metabolic stress are associated with changes in plasma amino acid profiles, but that such changes are aspecific and therefore poor indicators of disease severity.

Fully automated liquid-chromatographic determination of amino acids

This inexpensive method for fully automated amino acid analysis combines the advantages of automated precolumn derivatization with o-phthaldialdehyde and favorable analytical conditions to separate and quantify 30 amino acids found in normal plasma. The system can run unattended for almost four days, during which the data are processed automatically by a personal computer and a maximum of 76 samples and 19 standards can be processed (cycle time per analysis: 55 min). Only 1 microL of deproteinized plasma is required per analysis. Coefficients of variation for retention times and areas measured for all relevant amino acids are less than 1% and 3%, respectively. The system described is well suited for quick, sensitive operation in daily practice.

Fully automated liquid-chromatographic determination of amino acids

This inexpensive method for fully automated amino acid analysis combines the advantages of automated precolumn derivatization with o-phthaldialdehyde and favorable analytical conditions to separate and quantify 30 amino acids found in normal plasma. The system can run unattended for almost four days, during which the data are processed automatically by a personal computer and a maximum of 76 samples and 19 standards can be processed (cycle time per analysis: 55 min). Only 1 microL of deproteinized plasma is required per analysis. Coefficients of variation for retention times and areas measured for all relevant amino acids are less than 1% and 3%, respectively. The system described is well suited for quick, sensitive operation in daily practice.

Porcine intestinal ammonia liberation. Influence of food intake, lactulose and neomycin treatment

Lactulose and neomycin have, besides influencing ammonia production of the intestinal flora, been proposed to reduce glutamine-dependent ammonia formation. To test this hypothesis we determined the effects of lactulose and neomycin on the release or uptake of ammonia, urea, and amino acids across the intestine of freely moving healthy pigs. Blood was sampled from catheterized piglets (20 +/- 0.8 kg; n = 6) before and 1, 2, 3, and 6 h after a standard pig meal (750 g, 12% protein). After a week of lactulose (Legendal; 2 x 60 g/day) or neomycin (8 g/day) treatment this procedure was repeated. Electromagnetic portal and small bowel flow measurements were carried out in separate groups of pigs. Flow measurements were independent of the kind of food ingested. No significant alterations in flow could be detected during the 6 h study period. Portal and porto-arterial ammonia differences were significantly decreased after lactulose (-20%) and neomycin (-35%) treatment. alpha-Amino-nitrogen absorption decreased in both groups as compared to controls, but this decrease did not reach significance. Systemic and portal glutamine levels as well as intestinal glutamine utilization were significantly lower in the treatment groups. Citrulline and glutamate levels and intestinal production decreased after treatment. In this in vivo model, ammonia liberation after protein meals decreased in animals pretreated with lactulose or neomycin. The decreased systemic and consequently intestinal glutamine utilization may contribute to a reduction of endogenous ammonia formation in the gut wall. Diminished absorption from the gut of alpha-amino-nitrogen may, however, also contribute to a decrease in ammonia production.(ABSTRACT TRUNCATED AT 250 WORDS)

A technique to study splanchnic metabolism in the unrestrained conscious pig

In recent years similarities recognized between porcine and human anatomy and physiology have made the pig an experimental animal of considerable value in biomedical research. We developed a pig model for unrestrained repeated sampling of portal and arterial blood, and selectively of small and large bowel veins. Catheters were inserted, under halothane anesthesia, in ten female crossbred (Yorkshire x Dutch Landrace) piglets (8 weeks; 20 +/- 2 kg). After recovery for at least 3 days the catheters were used for sampling of blood. Aortic and portal catheters patency rates were 60% at day 24. For the small bowel catheters, a patency rate of 30% was seen at day 24. The large bowel patency rate was 30% at day 10. These results are promising because they allow long-term metabolic splanchnic research in unrestrained piglets.

gamma-Aminobutyric acid production in small and large intestine of normal and germ-free Wistar rats. Influence of food intake and intestinal flora

In recent hypotheses concerning the pathogenesis of hepatic encephalopathy, gamma-aminobutyric acid (GABA) is claimed to be produced by the colonic flora, although enzymes necessary to generate GABA have been reported to be present in intestinal mucosa. In this study, using normal and germ-free Wistar rats, we determined GABA levels and amino-grams of arterial blood and of venous effluent from small and large bowel. The data indicate that large and small intestinal mucosa significantly contribute to GABA production. In the fasted state GABA concentrations are greater in the venous effluent of the small bowel than in the venous effluent of the large bowel. Feeding increases the arterioportal differences, and uptake in the small bowel is still significantly higher than in the large bowel. This process is not, or can only be to a minor degree, bacterially mediated, because GABA production in the gut both in the fed and fasted state is of similar magnitude in germ-free and normal animals. gamma-Aminobutyric acid release correlates significantly with glutamine uptake in the small bowel of fasted rats. Only a small fraction of the glutamine taken up is needed to account for GABA release, so that conclusions concerning which amino acids may serve as precursors of GABA cannot be drawn. Further studies are needed to delineate the metabolic pathways leading to GABA synthesis.

Primary partial internal sphincterectomy in the treatment of anorectal abscess

Anorectal abscess is usually treated by simple incision and drainage. Many patients treated in this way will develop a recurrence of the abscess or a chronic anal fistula. In order to prevent such a recurrence partial internal sphincterectomy has been added to the incision and drainage. The results with this so-called primary partial internal sphincterectomy in 74 patients were excellent, because of absence of recurrent abscess or persistent fistula.