Growth hormone and experimental cancer cachexia.

Plasma levels of growth hormone (GH) and the effect of GH treatment have been evaluated in adult nongrowing sarcoma-bearing mice (C57BL/6J). Prepubertal tumor-bearing mice, tumor-bearing hypophysectomized Sprague-Dawley rats, and malnourished non-tumor-bearing animals served as additional groups of study and control animals. Adult sarcoma-bearing mice showed an increase in plasma levels of GH early following tumor implantation. GH levels increased further with tumor progression. The anorexia and the state of malnutrition in sarcoma-bearing mice were the major factors behind increased GH levels. Muscle wasting and body composition in the tumor-bearing host were not improved by GH treatment at doses that increased growth rate in normal growing mice with intact pituitaries or partially normalized growth rate in hypophysectomized rats. Exogenous GH supported tumor growth and host body growth to the same extent in hypophysectomized rats. Exogenous GH in excess of endogenous GH did not stimulate tumor growth further. It is suggested that increased GH production in a tumor-bearing host acts in concert with other hormones to stimulate endogenous substrate mobilization and in tumor-bearing animals to prevent substrate deficiency and hypoglycemia. On the basis of this conclusion, it is unlikely that GH supplementation to a freely eating tumor-bearing host will support replenishment of host tissues.

Role of insulin in development of cancer cachexia in nongrowing sarcoma-bearing mice: special reference to muscle wasting.

This study evaluated whether altered insulin metabolism is a key factor behind weight loss during sarcoma growth in nongrowing mice (C57BL/6J). Fasted sarcoma-bearing mice had decreased blood glucose concentrations but unchanged levels of insulin, compared with those in pair-weighed and freely fed controls. During refeeding, insulin levels were inappropriately low for the degree of glycemia in sarcoma-bearing mice compared with those of pair-weighed and freely fed controls. Injections ip of glucose to tumor-bearing animals resulted in insulin levels comparable to postabsorptive values in healthy control animals, indicating that hypoinsulinemia in freely eating tumor-bearing animals was due to a reduced glycemic sensitivity for pancreatic insulin release. Insulin supplementation at doses [4 IU/100 g (body wt)] that increase body fat in normal animals could not protect the tumor-bearing host from progressive loss of body fat or lean tissues. Exogenous insulin in excess of endogenous insulin production did not stimulate tumor growth. Nitrogen and RNA-DNA content were significantly decreased in the quadriceps muscle of tumor-bearing mice. This reduction was independent of altered insulin levels and could not be prevented by exogenous insulin. The depressed capacity of protein synthesis in extensor digitorum longus (EDL) muscle could be entirely attributed to the state of malnutrition in tumor-bearing animals. The sensitivity and responsiveness of protein synthesis in EDL muscles to insulin were normal in tumor-bearing mice, regardless of whether exogenous insulin exerted its effect in vivo or in vitro. This study confirms insulin resistance for glucose metabolism in an experimental sarcoma animal model. Such changes are concluded to be secondary to anorexia and necessary to counteract hypoglycemia. In non-growing sarcoma-bearing mice, malnutrition and anorexia account entirely for depressed muscle protein synthesis, which is not explained by insulin resistance at the translational level. Insulin metabolism is not a key factor behind progression of wasting in sarcoma-bearing mice, but anorexia is.

Tumor-host wasting not explained by adrenal hyperfunction in tumor-bearing animals.

This study addressed the question of whether hypercorticism in tumor-bearing animals contributes to the wasting of body fat and lean body mass, particularly that of skeletal muscles. For this purpose, hydrocortisone-substituted nongrowing sarcoma-bearing and control C57BL/6J mice were used that were either adrenalectomized or sham-operated prior to experimentation. Adrenalectomy in itself did not alter food intake or body composition in normal animals. Tumor-bearing mice and pair-weighted control animals had elevated urinary excretion of corticosteroids compared with the urinary excretion in freely fed controls. The malignant tumor induced the well-recognized wasting in tumor-bearing animals, irrespective of the presence of the adrenal glands. Therefore, an elevated corticosteroid production did not account for the wasting of body fat, lean body mass, skeletal muscle proteins, or decreased RNA activity in quadriceps muscles from tumor-bearing animals, although such muscles were sensitive to physiologic doses of injected hydrocortisone (20 micrograms/day). Tyrosine aminotransferase (TAT) activity in liver tissue from tumor-bearing animals was higher than that induced by pharmacologic doses of hydrocortisone in normal animals. Physiologic doses of hydrocortisone induced hepatic TAT activity, but pair-weighed control animals with the same degree of hypercorticism as was found in tumor-bearing animals had normal TAT activity in liver tissue. Although hypercorticism is present in tumor-bearing animals, the results demonstrate that cancer cachexia can start and proceed independently of the adrenal glands. Therefore, adrenal hyperfunction is not the proximate cause for the development of experimental cancer cachexia induced by anorexia.

Thyroid hormones and experimental cancer cachexia.

The relationship between circulating thyroid hormones and nutritional status was studied in sarcoma-bearing inbred C57BL/6J mice and control mice. Supplementation with exogenous thyroxine (T4) was also evaluated. Tumor-bearing animals had depressed levels of circulating thyroid hormones. This was also found in food-restricted (pair-fed and pair-weighed) controls. Plasma levels of thyroid hormones decreased with increased tumor burden. Thyrotropin-releasing hormone caused an increased response of thyroid-stimulating hormone in tumor-bearing animals. Low levels of thyroid hormones in sarcoma-bearing mice were due to depressed hormone production by the thyroid gland rather than to increased clearance rate of hormones. Plasma levels of triiodothyronine (T3) correlated to the amount of whole-body nitrogen among sarcoma-bearing mice and food-restricted controls. Exogenous T4 increased food intake by 20% in sarcoma-bearing mice. The benefit of this was probably counteracted by an increased metabolic rate, since reversal of plasma levels of T3 and free T4 had no net effect on body composition of freely eating sarcoma-bearing mice, although it had a negative effect on body and muscle composition in food-restricted controls. Exogenous T4 did not stimulate tumor growth. The results indicate that low circulating levels of thyroid hormones in experimental cancer cachexia are probably caused by the reduced food intake (anorexia), which is in agreement with findings in clinical cancer. Depression of thyroid hormones is probably a physiological means to reduce energy expenditure and to preserve substrates in progressive cancer disease.

Lack of evidence for elevated breakdown rate of skeletal muscles in weight-losing, tumor-bearing mice.

Protein degradation was measured as tyrosine release rate from proteins of extensor digitorum longus (EDL) muscles and as urinary excretion of 3-methylhistidine in freely fed adult nongrowing C57BL/6J mice with sarcomas, to study protein degradation in cancer-induced wasting of skeletal muscles. Whole muscle protein breakdown rate was unchanged, whereas protein synthesis was depressed, leading to an increased net degradation of skeletal muscles with loss of soluble, myofibrillar, and collagen proteins. Starvation for 24 hours elevated whole muscle protein breakdown in mice with and without sarcomas. Subsequent refeeding for 24 hours normalized the degradation. Adaptation to anorexia in pair-fed controls was achieved by a decrease in muscle protein turnover evaluated by urinary excretion of 3-methylhistidine over 5 days. The measurement of "catabolic decrease" of muscle protein breakdown protected the muscle mass in mice without tumors, but it was ineffective in tumor-bearing animals. The unchanged rate of breakdown of proteins in whole EDL muscles from tumor-bearing mice was accompanied by increased maximum cathepsin D activity and by elevated autolytic activity at acid pH in some muscles. Therefore, cathepsin D activity and net protease activities did not reflect whole muscle protein degradation in tumor-induced malnutrition. The results demonstrate that wasting of skeletal muscles in experimental cancer was not dependent on increased degradation but was dependent on depressed protein synthesis.

Flux of amino acids across the leg in weight-losing cancer patients.

Flux of amino acids across the leg was measured in malnourished cancer patients and three control groups: (a) malnourished patients without cancer; (b) well-nourished but acutely ill patients; and (c) well-nourished controls hospitalized for minor elective surgery. All patients were examined after an overnight fast, and some patients were reexamined 2 weeks later during enteral nutrition by gastric infusion of a formula diet. The efflux of amino acids did not differ qualitatively or quantitatively between malnourished cancer patients and malnourished patients without cancer. Well-nourished patients with acute illness had the greatest release of amino acids after an overnight fast. The leg efflux of amino acids did not correlate with plasma insulin levels in any of the patient groups, either in the fasting or in the fed state. Enteral nutrition decreased the efflux of amino acids from the leg in malnourished patients without cancer, but not in the malnourished cancer group. Enteral nutrition resulted in an increased peripheral uptake of energy precursors as glucose, free fatty acids, and the branched-chain amino acids. This was concomitant with increase in plasma level of triiodothyronine in malnourished patients without cancer. This study demonstrates that malnourished cancer patients do not differ from malnourished patients without cancer or from well-nourished patients after an overnight fast with respect to amino acid efflux from peripheral tissues, and thus shows normal adaptation for protein conservation. The results also suggest that conventional nasogastric tube-feeding was not sufficient alone to support normal replenishment of peripheral tissue in malnourished patients with and without cancer.

Efflux of 3-methylhistidine from the leg in cancer patients who experience weight loss.

An improved method for measurement of 3-methylhistidine in blood samples has been used to assess efflux of 3-methylhistidine from the leg in cancer patients experiencing weight loss. Three control groups were studied: malnourished depleted patients without cancer; comparatively well-nourished but acutely ill patients; and well-nourished controls, hospitalized for elective surgery, who showed no symptoms of metabolic disease. Well-nourished controls and acutely ill patients had a statistically significant release of 3-methylhistidine [1.92 +/- 0.40 (S.E.) nmol/min/100 g leg tissue and 0.93 +/- 0.32 nmol/min/100 g, respectively], but cancer patients and malnourished noncancer patients had insignificant efflux. When nutritional support was provided, noncancer patients abolished their previously negative tyrosine balance and increased the efflux of 3-methylhistidine; however, cancer patients as a group continued to show a negative tyrosine balance, and the efflux of 3-methylhistidine continued to decrease further in them. The results in this study demonstrate that weight loss in clinical cancer is not dependent on increased skeletal muscle protein degradation, not even at an early stage of the disease. It seems likely that decreased protein synthesis is a more important factor.

Anti-inflammatory treatment may prolong survival in undernourished patients with metastatic solid tumors.

Eicosanoids may be important factors for tumor cell proliferation, metastatic formation, and development of cancer cachexia. The present study has evaluated the effect of anti-inflammatory treatment on tumor progression in clinical cancer. Patients (n = 135) with insidious or overt malnutrition due to generalized malignancy (various kinds of solid tumors) and an expected survival of more than 6 months were randomized by a computer-based algorithm to receive placebo, prednisolone (10 mg twice daily), or indomethacin (50 mg twice daily) p.o. until death. Patient groups were stratified in the randomization procedure for sex, tumor type, stage, nutritional state, and previous tumor treatment, and biochemical, physiological, and some functional variables (Karnowsky index, fatigue and pain score). A majority of these variables was then registered during the follow-up. Indomethacin and prednisolone treatment maintained Karnowsky index, while placebo-treated patients experienced a decreased index. Indomethacin-treated patients suffered less pain and consumed less additional analgetics compared to the other patient groups. Indomethacin prolonged mean survival compared to placebo-treated patients from 250 +/- 28 days to 510 +/- 28 days (P < 0.05). Survival analysis on observations from all patients treated with either indomethacin or prednisolone demonstrated a significantly prolonged survival by anti-inflammatory treatment compared to placebo treatment (log rank, P < 0.03). The results suggest that not only may prostaglandin synthesis inhibition offer palliative support to patients with solid advanced cancer, but it may also impact on pathways that ultimately determine outcome.

Effects related to indomethacin prolonged survival and decreased tumor-growth in a mouse-tumor model with cytokine dependent cancer cachexia.

Tumor-bearing mice with two different locally growing malignant tumors (epithelial like, MCG 101; malignant melanoma, K1735-M2) were used to evaluate the putative role of prostaglandins for survival and local tumor growth in experimental cancer. Daily systemic injections of indomethacin (1 mu g/g bw) were used to block prostaglandin production in normal and T-cell deficient tumor-bearing nude mice. Tumor progression was determined by measurements of tumor weight, DNA-synthesis, cell cycle kinetics in vivo and in vitro (flow cytometry), tumor tissue concentrations of polyamines (putrescine, spermidine, spermine) and tumor tissue gene expression of growth regulating factors (IL-1 alpha, IL-6, TNF alpha, A,B-PDGF, EGF, VEGF, bFGF, TGF beta(3), angiogenin and transferrin receptor). Tumor tissue content of von Willebrandt factor VIII was estimated by immunohistochemistry. Indomethacin had no effect on survival, host nutritional state or local tumor growth in mice bearing the malignant melanoma with low PGE(2) production. In contrast, indomethacin prolonged survival, improved cachexia and decreased tumor growth in mice bearing the MCG 101 tumor with hundredfold higher prostaglandin tumor production, leading to elevated liver and muscle tissue as well as plasma concentrations of PGE(2). Indomethacin inhibited almost completely the high tumor PGE(2) production in MCG tumors, leading to prolonged potential doubling time for tumor growth in vivo, and a trend to decreased tumor tissue concentration of polyamines (spermidine). Indomethacin had no inhibitory effect on tumor cell proliferation in vitro, although PGE(2) production was decreased by 75%. The effect of indomethacin in vivo was independent of T-cells and was observed with similar magnitude irrespective of the number of MCG cells (10(4)-10(6)) implanted or the site of implantation (s.c., i.p., liver, lung, skeletal muscles). Tumor growth inhibition by indomethacin was not intrinsically transferable by tumor cells from indomethacin treated tumor-animals. Tumor expression of mRNA for several growth regulating factors were either increased (IL-6, TNF alpha, GM-CSF, TGF beta(3)) unchanged (EGF, VEGF, PDGF A,B, IL-1 alpha, transferrin receptor) or decreased (b-FGF and angiogenin) (p<0.05) by indomethacin treatment of MCG mice. Decreased tumor content of von Willebrandt factor VIII in combination with an attenuated tumor vasculature were associated with decreased tumor growth (p<0.05). Our results confirm that high tumor production of prostaglandins was related to reduced survival. Tumor prostaglandins probably promote local tumor growth by stimulation of tumor surrounding cells to produce growth factor(s) for tumor angiogenesis including tumor and matrix cell proliferation unrelated to immune cells.

The effect of clenbuterol on body composition in spontaneously eating tumour-bearing mice.

The aim of this study was to investigate the effect of a selective beta 2-adrenoceptor agonist, clenbuterol, on body composition in tumour-bearing adult and growing mice. Therefore, adult female C57/BL6 mice (n = 20) were inoculated subcutaneously with a 3-methylcholanthrene-induced sarcoma and divided into two identical groups. One group received injections twice a day of clenbuterol corresponding to 1 mg/kg body weight, the other group received sham injections. Growing mice (n = 20) were similarly divided after tumour inoculation into one study group with clenbuterol injections and one control group. The growing animals were sacrificed on day 11 after commencement of treatment, the adult mice on day 16. Clenbuterol treatment had no statistically significant effect on accumulated food intake or body composition in the adult mice. However, food intake in these animals increased numerically compared to control animals after day 11 of the study. Tumour growth was also unaffected. The growing animals displayed an increased carcass dry weight with borderline significance (p = 0.06) and an increased quadriceps muscle fat free dry weight after clenbuterol treatment. Tumour growth was not affected. Food intake measured on a daily basis was significantly increased in the growing clenbuterol treated animals and accumulated food intake was increased with a trend towards statistical significance (p = 0.06). The results support the suggestion that treatment with a selective beta 2-adrenoceptor agonist does not improve body composition in tumour-bearing adult mice relying on spontaneous food intake while growing animals may benefit from such treatment.

Mouse extensor digitorum longus muscle preparation as a tool in nutrition research: a quantitative comparison to in vivo and cell culture experiments.

Incubated restrained and unrestrained extensor digitorum longus (EDL) muscles from adult non-growing mice were evaluated as a tool in non-steady state nutrition experiments. Energy state was determined by nucleotide determinations in muscles. Protein synthesis was estimated by the amount of L-[U-14C]phenylalanine incorporated into proteins, and protein balance was measured by tyrosine release from muscle proteins. Confluent cultured L6 rat muscle cells served as a reference system in steady state without hypoxia being sensitive to growth factors and regulatory peptides at physiologic concentrations. Irrespective of medium composition, incubated EDL muscles remained in negative protein balance, being unrelated to the resting tension of the incubated muscles. Energy-rich phosphates were not restored to normal levels during incubation, but protein synthesis was not attenuated by the decline in energy state. Fractional protein synthesis (0.05-0.15%/h) remained constant for up to 6 h of EDL incubation, and was comparable to protein synthesis in cultured confluent non-proliferating myocytes (0.20-0.30%/h) and to mixed leg muscles measured in vivo (0.10-0.20%/h). Protein synthesis in incubated EDL muscles reflected alterations in muscle peptide formation in vivo following either oral provision of food or parenteral injection of insulin. EDL muscles were sensitive to in vitro exposure to both insulin (60-125 microU/mL) and insulin-like growth factor 1 (IGF-1) (1000 ng/mL). The sensitivity to insulin seemed to be modified by the nutritional state (starved/fed) of the animals before sacrifice. Protein synthesis in EDL muscles was less responsive to serum-containing growth factors (IGF-1, epidermal growth factor [EGF], platelet-derived growth factor [PDGF]) compared to confluent L6 muscle cells, which probably reflected different receptor expression. Our results demonstrate that protein metabolism in incubated unrestrained mouse EDL muscles reflects in vivo protein metabolism.

Facts about the Kock continent ileostomy.

A great number of publications on the results obtained by different techniques employed for construction of the continent ileostomy have been published over the years. Unfortunately, many reports are incomplete or presented in such a way that they do not allow for proper interpretation or mutual comparison. Analysis of the collective results obtained from studies where the different techniques employed are accurately described and complications properly specified demonstrates more clearly what measures may improve the success rate and which factors have to be taken into account for anyone who is going to adopt the method.

The Kock continent ileostomy: influence of a defunctioning ileostomy and nipple valve stapling on early and late morbidity.

Early and late morbidity was studied in 45 consecutive patients submitted to the Kock continent ileostomy reservoir procedure protected by a temporary loop ileostomy. In 24 patients the nipple valve was made by simple intussusception of the ileal segment after stripping of its mesenteric peritoneum and fat, whereas in 21 patients the nipple valve was stapled in addition. The early complication rate was low with necrosis of the nipple valve occurring in 3 patients and a nipple valve fistula in 1. These complications were easily dealt with and revision was done subsequently on an elective basis. The overall revision rate for late nipple valve dysfunction, mainly caused by sliding of the nipple valve was 29%. The majority of these complications occurred within the first postoperative year. Stapling of the nipple valve did not significantly reduce the rate of sliding. The overall complication rate was significantly less compared with a historical series of 21 patients not provided with a loop ileostomy. A temporary defunctioning ileostomy may reduce early complications and their consequences. Whether it may also lessen the risk of later nipple valve sliding is, however, not clear from this study. The observation that sliding was as common in both unstapled and stapled patients could imply either that the loop ileostomy is beneficial in preventing this complication or that the stapling procedure is in this respect unimportant. Which step or steps among all the measures employed are important in increasing the success rate of this operation remains unclear. Randomised controlled studies are needed for a true evaluation of this issue.

The cause of death in non-metastasizing sarcoma-bearing mice. A study with relevance for tumor treatment experiments in mice.

Adult sarcoma-bearing mice were used to demonstrate whether hypoglycemia was the immediate cause of death in experimental animals with rapidly growing tumors without metastases. This kind of tumor model is representative of the majority of animal models used in experimental cancer research. Tumor-bearing animals died with severe hypoglycemia under all experimental conditions, while pair-killed controls were normoglycemic. Anorexia prevented tumor-bearing animals from attenuating the hypoglycemia by drinking glucose-containing water while completely starved control animals survived more than 14 days with glucose-containing water as the only energy source. Adrenalectomy shortened survival in tumor-bearing animals, but survival of adrenalectomized tumor-bearing animals could be normalized by daily injections of pharmacologic doses of hydrocortisone (25 mg/25 g body wt/day) but not by physiologic replacement (20 micrograms/25 g body wt/day). Injections of pharmacologic doses of hydrocortisone did not influence on survival or body composition in tumor-bearing animals with intact adrenals. Glucagon was without effect on either survival, tumor growth or body composition. Based on the results in this study and in our previous reports we conclude that hypoglycemia is the cause of death in the majority of murine tumor models. This hypoglycemic theory is important, since any treatment modality in animal experiments that influences glucose metabolism in the host may indirectly change tumor growth and may thus be misinterpreted as a direct tumor effect.

Increased urinary excretion of cortisol and catecholami-NES in malnourished cancer patients.

Excretion of cortisol and catecholamines were measured from 24-hour urine samples collected over a period of 3 days from hospitalized cancer patients suffering from malnutrition and were compared with those of control patients equally malnourished and having a similar degree of inflammation. Compared with control patients, cancer patients had a higher excretion of cortisol, adrenaline, and noradrenaline, although noradrenaline excretion reached statistical significance only when normalized to creatinine excretion. Plasma glycerol concentrations after an overnight fast were significantly higher in cancer patients as compared with control patients, in keeping with an increased adrenal and adrenergic activity. This study demonstrates evidence of simultaneously elevated catecholamine and cortisol excretion in cancer patients, which could not be ascribed to alteration in body composition. The results may, in part, explain the mechanisms behind ongoing tissue breakdown in progressive cancer disease.

Incidence and characteristics of pouchitis in the Kock continent ileostomy and the pelvic pouch.

The incidence, the median time to first appearance, and the clinical pattern of pouchitis were prospectively studied in 180 patients operated on for ulcerative proctocolitis with a continent ileostomy (CI; 84 patients) and a pelvic pouch (PP; 96 patients). Median follow-up for CI patients was 8.5 years (range, 2-15 years) and for PP patients, 5 years (range, 1-8 years). Pouchitis, with symptoms severe enough to require treatment, developed in 33% (28 of 84) of CI and 47% (45 of 96) of PP patients. The cumulative risk of developing one or more episodes of pouchitis over a 5-year follow-up was 34% in CI patients and 51% in PP patients. The median time to first appearance of pouchitis was 5 and 12 months, respectively. Eighty-six per cent of CI patients with pouchitis (24 of 28) and 71% of PP patients (32 of 45) experienced their initial episode within the first 2 years. Sixty-four per cent (18 of 28) of the CI patients and 76% (34 of 45) of PP patients had one single or a few short-lasting episodes of pouchitis with various symptom-free intervals, whereas 18% of patients in each group (5 of 28 CI patients, 8 of 45 PP patients) had frequent relapses. Most of these patients responded promptly to metronidazole treatment. Eighteen per cent (5 of 28) of CI patients and 6% (3 of 45) of PP patients had long-lasting episodes with a poor response to treatment. In this long-term study the pouch inflammation proved eventually to be Crohn's disease in four patients (2.2%).(ABSTRACT TRUNCATED AT 250 WORDS)

Autosuture of low colorectal anastomosis.

The safety of low colorectal anastomosis constructed with autosuture technique (U.S. EEA-stapling device, USSC) and the functional results were assessed in consecutive series of patients operated upon for rectal carcinoma. The operative procedure was greatly facilitated and certainly, many of the patients would otherwise have been subjected to abdominoperineal resection with permanent colostomy. Clinical leaks were observed in 4 of the 25 patients (16%) and another 4 patients were shown to have subclinical leaks, as demonstrated by endoscopy and/or X-ray. The total incidence of leaks was therefore 32% (8/25). Even when constructed with the autosuture technique a low anastomosis should probably be protected by a proximal enterostomy. There was a general tendency to anastomic narrowing during the initial period but in most patients stenosis disappeared with time after closure of the enterostomy. Frequent endoscopic examinations and dilatation of the anastomosis during the early postoperative period may be advantageous. The immediate functional results were unsatisfactory with increased frequency and varying grades of incontinence. Although these disturbances improved with time the results at six months after surgery were still not satisfactory and for confidence many patients wore a pad.