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Query: UMLS:C0009402 (colorectal cancer)
 53,228 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is well known that chronic inflammation of the colon and rectum is associated with an increased risk of colorectal cancer, but the mechanisms by which inflammation promotes neoplasia remain undefined. The authors propose that inflammatory neutrophils may produce carcinogenic nitrosamines via the L-arginine-dependent formation of nitrogen oxides such as nitric oxide. Therefore, the objectives of the study were to characterize the L-arginine-dependent formation of nitrogen oxides by inflammatory (elicited) neutrophils using conditions that more closely mimic the extravascular (i.e., interstitial) compartment of the gut and to characterize the neutrophil-dependent N-nitrosation of a model amine to yield its nitrosamine derivative. In the absence of any metabolic activation, adherent, inflammatory neutrophils (2 x 10(6) cells) produced 12.8 +/- 1.4 mumol/L of nitrite during a 4-hour incubation period. Omission of L-arginine and/or inhibition of nitric oxide synthase by the addition of 1 mmol/L NG-nitro-L-arginine methyl ester (L-NAME) resulted in 35%-78% inhibition of nitrite production, suggesting that nitrite was derived from nitric oxide. By comparison, neither circulating rat neutrophils nor elicited rat macrophages produced significant amounts of nitrite under the same conditions. Furthermore, elicited neutrophils (2 x 10(6) cells) were capable of N-nitrosating 2,3-diaminonaphthalene to yield its nitrosamine derivative 1-naphtho-2,3-triazole (282 +/- 12 nmol/L) in a time- and cell-dependent pattern similar to that of nitrite production. Addition of a variety of antioxidants (e.g., ascorbic acid, reduced glutathione, alpha-tocopherol analog), 5-aminosalicylic acid, or L-NAME resulted in 80%-85% inhibition of neutrophil-mediated nitrosamine formation. Taken together, these data suggest that inflammatory neutrophils may represent an important metabolic source of endogenous carcinogens during times of active intestinal inflammation.
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PMID:Neutrophil-mediated nitrosamine formation: role of nitric oxide in rats. 139 83

Cryosurgery, using liquid nitrogen at -196 degrees C, was explored for treating colorectal liver metastases in an experimental study of rat colon cancer and in a clinical investigation of patients with unresectable liver tumors. The viability of rat colon cancer isografts showed that while two or three freeze-thaw cycles were 100% effective in controlling established isografts and preventing isograft take, one freeze-thaw cycle was suboptimal. In these animals cryosurgery was as effective as surgical resection in controlling established experimental liver metastases. Cryosurgery by operative liver exposure and intraoperative ultrasound monitoring were used to treat liver metastases from colorectal cancer in 24 patients. At a median follow-up of 2 years (range, 5 months to 5 years), seven patients (29%) are disease free, eight (33.5%) are alive with recurrent tumors, and nine (37.5%) have died. The patterns of failure were: remaining liver and extrahepatic sites, ten patients (59%); remaining liver only, six patients (35%); and extrahepatic only, one patient (6%). These data demonstrate that cryosurgery is a useful modality for treating unresectable primary and metastatic liver cancers. Addition of systemic adjuvant therapy may improve the tertiary failure following the control of liver metastases.
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PMID:Experimental and clinical observations on hepatic cryosurgery for colorectal metastases. 193 94

Eleven patients with multiple hepatic metastases from colorectal cancer, all judged inoperable, were treated by cryotherapy using a probe through which liquid nitrogen was circulated using a single freeze thaw sequence. Localization of metastases, positioning of the probe and monitoring of ice ball size was by intra-operative ultrasound. Serum carcinoembryonic antigen (CEA) was measured in these patients: there was a postoperative fall in all but two. In all but one, there has been a subsequent rise. Speed and degree of rise of CEA varied between patients. Serial CEA may be an effective means of monitoring the effect of hepatic cryotherapy.
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PMID:Effect of hepatic cryotherapy on serum CEA concentration in patients with multiple inoperable hepatic metastases from colorectal cancer. 199 85

The aim of this study was to investigate the nitrogen-sparing effect of hypocaloric parenteral nutrition (HPN) with a balanced amino acid supply compared with that of a standard Rose's formula. Eighteen well-nourished patients with colorectal cancer were randomly distributed into 3 groups: I control, II Study group, III Rose's formula. The amount of non-protein calories was similar in both groups: 8 kcal/kg administered as glucose, and 1.33 g of amino acid/kg was also infused during 5 days. There were no differences in the plasma protein levels of total proteins, albumin, and transferrin, but retinol-binding protein was higher in group II compared with the control. Nitrogen balance was significantly better in group II than in group III during the 3rd and 4th days. There were differences in the concentration of aspartic acid and glycine in the plasmatic aminograms between groups II and III. It was concluded that the balanced amino acid solution does not significantly improve a patient's nutritional state. Nor have we observed that the balanced amino acid solution causes fewer modifications in the plasma aminograms. However, it does achieve a slight improvement in the nitrogen balances and the synthesis of retinol-binding protein.
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PMID:Effect of balanced amino acid solution on protein metabolism after surgery. A clinical study. 211 36

From the 200 malnutritional cancer patients, we had obtained, so called, prognostic nutritional index (PNI): PNI = 10 X Alb. + 0.005 Lymph. C., where Alb. is serum albumin level (g/dl) and Lymph. C. is total lymphocytes count of peripheral blood level. This index, as we had reported, shows linear predictive model correlating the risk of operative complication, mortality or both with nutritional status. In this study, we report on the utility of the PNI as a nutritional index (NI) for postoperative patients. The subjects of this study were 22 gastric cancer patients (G group), performed total gastrectomy or proximal gastrectomy, and 18 colorectal cancer patients (C group), underwent colectomy or rectal resection and anastomosis but amputation. All these cases underwent nutritional support by TPN postoperatively. The values of NI of both groups were the lowest at the first postoperative day, and increased gradually to the seventh postoperative day. And the value of C group was higher than that of G group throughout the TPN period: From the first postoperative day to the 14th day. These results reflected the result obtained from the estimation of nitrogen balance, urinary 3-methylhistidine excretion and serum rapid turnover protein (transferrin, prealbumin and retinol binding protein). These results suggest that the NI is useful to estimate the improvement of the postoperative nutritional status.
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PMID:[Postoperative nutritional assessment in gastric and colorectal cancer]. 309 25

The short and long-term effects of postoperative total parenteral nutrition (TPN) on body composition were studied in a randomised series of patients undergoing major colorectal surgery. Ninety-two patients (colorectal cancer: 50, ulcerative colitis or Crohn's disease: 42) were grouped according to diagnosis and clinical inflammatory activity. TPN was given for 9.7 +/- 1.1 days. The complication rate was not changed by the TPN. Nitrogen balance was studied during the first week. Body weight, total body potassium, triceps skinfold, serum albumin and body water were measured before and at intervals up to 24 weeks after the operation. Cumulative nitrogen balance in control patients at 7 days after surgery was -47.3 g. Patients given TPN balanced nitrogen intake and output (cancer patients and patients with quiescent inflammatory bowel disease, IBD) or were in positive balance (patients with active IBD). Weight loss at 1 week after surgery was less in TPN patients compared to controls and this difference remained statistically significant up to 6 months after termination of the nutritional treatment. A similar, although not statistically significant, difference was noted in total body potassium and triceps skinfold. Patients with active IBD regained pre-operative body composition earlier than cancer patients and patients with quiescent IBD. It is concluded that TPN after major colorectal surgery reduces postoperative weight loss and that this effect lasts after termination of the nutritional treatment. In the absence of increased body potassium and increased body water, we conclude that the long-term effect of TPN on body weight is most likely due to preservation of fat.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The immediate and long-term effects of postoperative total parenteral nutrition on body composition. 311 32

An electrophilic center at saturated carbon generated by the departure of molecular nitrogen shows minimum discrimination between various nucleophiles. The generation of such a center in the active site of a protein is therefore an attractive way of labeling that active site. The chemistry of deamination reactions will be discussed with respect to the practicality of triggering the deamination in the active sites of proteins. Successful applications of this principle using the N-nitrosamide functionality, the alkyl aryl triazene functionality, and the diazo functionality will be described. Reasons why active-site reagents incorporating this type of covert electrophilicity are more specific than those incorporating an overtly electrophilic center (such as -CO-CH2-Halogen) will be advanced. The actual and potential application of deamination precursors to the specific inhibition of physiological activities in living cells will be discussed.
CRC Crit Rev Biochem 1982 Apr
PMID:Affinity labeling via deamination reactions. 628 35

1. The rate of whole-body nitrogen flux, protein synthesis and protein breakdown were measured in patients with colorectal cancer (Dukes A-C) just before and 12 weeks after surgical removal of the tumour. The rates were determined from the urinary excretion of 15N in ammonia and in urea over a 9 h period after an oral dose of [15N]glycine. 2. The food intake during the 2 study days was identical for individual patients. The amount each received was determined from measurement of their intake of food ad libitum on the day preceding the pre-operative study and was consumed in six equal portions every 2 h during the experimental period. 3. No significant differences in the rates of nitrogen flux, protein synthesis and protein breakdown were found before and after tumour resection, whether calculated from the excretion of 15N in ammonia or in urea. Some changes in flux, both increases and decreases, were observed in individual patients after tumour removal but these could not be related to classification of the tumour, or to the presence of pre-operative anorexia or weight loss. 4. The results suggest that the primary tumour itself does not alter the overall rate of protein metabolism in the whole body.
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PMID:Whole-body protein turnover before and after resection of colorectal tumours. 682 46

Hepatic artery infusion (HAI) of fluoroudeoxyuridine (FUDR) has been shown to be effective in the treatment of liver metastases from colorectal cancer. However, local toxicity is the most serious limitation of this therapy. The aetiology of HAI toxicity remains unclear. To assess the HAI toxicity, forty-eight non-tumour-bearing, healthy BD-IX rats were randomized to control or treatment groups. The control group (n = 24) received heparinized saline alone (200 u heparin kg-1 day-1) and the treatment group (n = 24) received 6.7 mg FUDR kg-1 day-1 (equivalent to the human dose of 1.0 kg-1 day-1) via HAI for 28 days. Blood samples were collected for haematologic and biochemical analysis twice a week (on days 3 and 7). Toxicity was evaluated by determination of mortality, body weight, white blood cell (WBC) count, serum glutamic oxaloacetic transaminase (SGOT), alkaline phosphatase (ALP), total bilirubin and blood urea nitrogen (BUN), and creatinine. No significant differences in WBC, SGOT, BUN and creatinine levels were found between the group receiving FUDR treatment and the control group. Significantly higher total bilirubin levels, mortality and body weight loss were found in the FUDR-treated group than in the control group. A multivariate analysis revealed that total bilirubin level was the only significant predictor of mortality in the FUDR treatment group. These results suggested that biliary tract damage seems to be the principal toxicity of HAI FUDR chemotherapy.
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PMID:Toxicity study of hepatic artery infusion chemotherapy with massive dose FUDR in rats. 758 87

There are only a few experimental investigations on the feasibility and potential advantages of intraportal nutrition in animals and only two uncontrolled studies in humans. The purpose of this study was to compare some metabolic variables in patients who received portal or systemic nutrition after elective surgery for colorectal cancer. Twenty patients were randomized to receive postoperatively for a week a hypocaloric, "protein sparing" standard infusion via the portal (catheter in the gastroepiploic vein) (10 patients) or systemic (10 patients) route. We evaluated the basal concentrations of some visceral and acute-phase proteins and their variations in the first postoperative week and the nitrogen balance. Statistical analysis was performed by the two-tailed Student t test. There was no difference in the daily changes of the visceral and acute-phase proteins after surgery in the two groups of patients, but in the portal group there was a significantly better recovery of the level of total protein, albumin, and cholinesterase at the end of the portal infusion vs the systemic group (p < or = .005, .03, and .02, respectively). In regard to the nitrogen balance, although there was no difference in the overall balance between portal and systemic nutrition, if we separate the acute phase of the injury from the later one we do not see any significant difference in the first period but we do see a highly significant advantage for the portal group during the last 2 days (p < or = .0001).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Does portal nutrition benefit liver protein synthesis? 843 18


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