Adjuvant perioperative portal vein or peripheral intravenous chemotherapy for potentially curative colorectal cancer: long-term results of a randomized controlled trial.

BACKGROUND AND AIMS: The perioperative use of a single course adjuvant portal vein infusion chemotherapy in patients with potentially curable colorectal cancer has been shown to significantly improve overall survival but did not reduce the occurrence of liver metastases (SAKK 40/81) [Swiss Group for Clinical Cancer Research (SAKK) Lancet 345(8946):349-353, 1995]. The objective of the present prospective, three-arm randomized multicenter trial was to assess whether peripheral venous administration of adjuvant chemotherapy regimen based on 5-fluorouracil (5-FU) and mitomycin C decreases the occurrence of liver metastases as well as prolongs disease-free and overall survival. MATERIALS AND METHODS: Stages I-III colorectal cancer patients (n = 753) were randomized to receive either surgery alone (control arm), surgery plus postoperative portal venous infusion of 5-FU 500 mg/m(2) plus heparin given for 24 hours for seven consecutive days plus mitomycin C 10 mg/m(2) given on the first day (arm 2), or surgery and the same chemotherapy regimen administered by peripheral venous route (arm 3). RESULTS: The 5-year disease-free survival for the three treatment groups were 65% (control group), 60% (portal vein infusion, hazard ratio 1.18, p = 0.23), and 64% (intravenous infusion, hazard ratio 1.04, p = 0.76); the 5-year overall survival was 72% (control group), 69% (portal vein infusion, hazard ratio 1.21, p = 0.2), and 74% (intravenous infusion, hazard ratio 1.03, p = 0.86), respectively. A significant accumulation of early deaths were observed in the portal vein infusion group (p = 0.015). CONCLUSIONS: The present prospective randomized multicenter trial provides compelling evidence that short-term perioperative chemotherapy does not improve disease-free and overall survival in patients with potentially curative colorectal cancer. In contrary, the chemotherapy regimen administered in the present investigation seems to have potentially harmful effects, a finding which should be carefully considered in the planning of future trials. Postoperative short-term administration of 5-FU plus mitomycin C either through portal infusion or a central venous catheter is not recommended for routine use in patients with potentially curable colorectal cancer.

Pamidronate reduces bone loss after allogeneic stem cell transplantation.

BACKGROUND: Rapid bone loss occurs from the proximal femur after allogeneic stem cell transplantation (alloSCT). OBJECTIVE: The objective of the study was to evaluate effects of high-dose pamidronate therapy on bone loss (BMD) after alloSCT. DESIGN: This was a randomized, multicenter, open-label, 12-month prospective study of iv pamidronate (90 mg/month) beginning before conditioning vs. no pamidronate. All 116 patients also received calcitriol (0.25 microg/d) and calcium (1000 mg/d), which were continued for another year. MAIN OUTCOME MEASURES: Primary objectives were to compare changes in BMD 12 months after alloSCT at the femoral neck, lumbar spine, and total hip between the treatment arms and assess influences of glucocorticoid and cyclosporin therapy on these changes. RESULTS: Pamidronate reduced bone loss at the spine, femoral neck, and total hip by 5.6, 7.7, and 4.9% (all P < or = 0.003), respectively, at 12 months. However, BMD of the femoral neck and total hip was still 2.8 and 3.5% lower than baseline, respectively (P < 0.05) with pamidronate. Only differences at the total hip remained significant between the two groups at 24 months. Benefits were restricted to patients receiving an average daily prednisolone dose greater than 10 mg and cyclosporin therapy for more than 5 months within the first 6 months of alloSCT. CONCLUSIONS: Pamidronate markedly reduced but did not completely prevent postallogeneic bone marrow transplantation bone loss. BMD benefits were greatest in patients on higher doses of immunosuppressive therapy, but most were lost 12 months after stopping pamidronate. Studies of more potent bisphosphonates or anabolic therapy with PTH after alloSCT are warranted with the aim of durable maintenance of bone mass.

SMAD4 is a predictive marker for 5-fluorouracil-based chemotherapy in patients with colorectal cancer.

The gene for the transducer of transforming growth factor-beta/bone morphogenetic protein signalling SMAD4, a potential suppressor of colorectal carcinogenesis, is located at the chromosomal region 18q21. In order to evaluate the clinical relevance of SMAD4 deletion, gene copy alterations were determined by copy dosage using real-time quantitative PCR in 202 colorectal tumour biopsies from a previous randomised study of adjuvant chemotherapy. Patients with normal SMAD4 diploidy turned out to have a three-fold higher benefit of 5-fluorouracil-based adjuvant chemotherapy with a border line significance (overall survival: 3.23, P=0.056; disease-free survival: 2.89, P=0.045). These data are consistent with the previous observation that patients whose cancer had retention of the 18q21 region had a significantly higher benefit from 5-fluorouracil-based therapy. Moreover, these results may provide a refinement at the gene level of the clinical relevance of 18q21 deletion, thereby suggesting SMAD4 as a predictive marker in colorectal cancer. This data also indicate that integrity of this component of the transforming growth factor-beta/bone morphogenetic protein signalling pathway may be a critical factor for benefit of chemotherapy in patients with colorectal cancer.

Complete nucleotide sequence of the Oenothera elata plastid chromosome, representing plastome I of the five distinguishable euoenothera plastomes.

We describe the 159,443-bp [corrected] sequence of the plastid chromosome of Oenothera elata (evening primrose). The Oe. elata plastid chromosome represents type I of the five genetically distinguishable basic plastomes found in the subsection Euoenothera. The genus Oenothera provides an ideal system in which to address fundamental questions regarding the functional integration of the compartmentalised genetic system characteristic of the eukaryotic cell. Its highly developed taxonomy and genetics, together with a favourable combination of features in its genetic structure (interspecific fertility, stable heterozygous progeny, biparental transmission of organelles, and the phenomenon of complex heterozygosity), allow facile exchanges of nuclei, plastids and mitochondria, as well as individual chromosome pairs, between species. The resulting hybrids or cybrids are usually viable and fertile, but can display various forms of developmental disturbance.

Quality of life as subjective experience: reframing of perception in patients with colon cancer undergoing radical resection with or without adjuvant chemotherapy. Swiss Group for Clinical Cancer Research (SAKK)

PURPOSE AND BACKGROUND: We examined whether patients with colon cancer undergoing surgery with or without adjuvant chemotherapy change the internal standards on which they base their quality-of-life (QL) estimation, and, if they do so, whether this reframing alters interpretation of QL findings. These questions were addressed within a randomized clinical trial of the Swiss Group for Clinical Cancer Research (SAKK 40/93). PATIENTS AND METHODS: After radical resection of adenocarcinoma of the colon (pT1-4pN > 0M0 and pT3-4pN0M0) and perioperative chemotherapy, patients were randomized to three treatment arms: observation only (A), 5-FU 450 mg/m2 plus Levamisol (B), or 5-FU 600 mg/m2 (C). QL was measured by linear analogue self-assessment indicators. Patients estimated their pre-surgery QL both before surgery and retrospectively thereafter, and their pre-adjuvant QL both at the beginning of randomly assigned chemotherapy or observation and retrospectively about two months later. Thereafter, current QL was assessed. Paired t-tests were used to test the hypotheses of no change. RESULTS: Overall, 187 patients with at least one pair of corresponding questionnaires were analyzed. Patients estimated their pre-surgery QL after surgery significantly lower than before and their pre-adjuvant QL under treatment or observation also lower than at the beginning. In the adjuvant phase, in contradiction to our hypothesis, chemotherapy had almost no impact on these changes attributed to reframing. Conventionally assessed changes indicated an improvement in QL. Patients with treatment C reported less improvement in functional performance than those with B or those under observation (P = 0.04). Patients with treatment B indicated a greater worsening in nausea/vomiting than those with C, whereas patients with observation only showed an improvement (P = 0.0009). After adjustment of current QL scores under treatment or observation to patients' retrospective estimation, the treatment effects were diluted but the overall improvement was substantially amplified in most QL indicators. CONCLUSIONS: Patients with colon cancer substantially reframe their perception in estimating QL both under radical resection and under adjuvant chemotherapy or observation. This effect is an integral part of patients' adaptation to disease and treatment. An understanding of this phenomenon is of particular relevance for patient care. Its role in evaluating QL endpoints in clinical trials needs further investigation.

[ 40 years of 5-fluorouracil--still an attractive cytostatic]. / 40 Jahre 5-Fluorouracil--ein nach wie vor attraktives Zytostatikum.

On its 40th birthday 5-fluorouracil (FU) is still an attractive drug frequently employed in adjuvant and palliative treatment of colorectal and breast cancer, head and neck cancer, oesophageal cancer and anal cancer. After all this time it is still not known what the optimal schedule or the best form of administration is, and whether or not modulation of the drug is of any benefit. This article deals with the drug's different modes of action depending on the schedule of administration. An overview of the literature on drug modulation is given. We introduce the less well-known side effects of the drug and the newly developed orally administered prodrugs of FU.

Cloning, expression, and spectroscopic characterization of Cucumis sativus stellacyanin in its nonglycosylated form.

The cDNA encoding the 182 amino acid long precursor stellacyanin from Cucumis sativus was isolated and characterized. The protein precursor consists of four sequence domains: I, a 23 amino acid hydrophobic N-terminal signal peptide with features characteristic of secretory proteins; II, a 109 amino acid copper-binding domain; III, a 26 amino acid hydroxyproline- and serine-rich peptide characteristic of motifs found in the extension family, extracellular structural glycoproteins found in plant cell walls; and IV, a 22 amino acid hydrophobic extension. Maturation of the protein involves posttranslational processing of domains I and IV. The copper-binding domain (domain II), which shares high sequence identity with other stellacyanins, has been expressed without its carbohydrate attachment sites, refolded from the Escherichia coli inclusion bodies, purified, and characterized by electronic absorption, EPR, ESEEM, and RR spectroscopy. Its spectroscopic properties are nearly identical to those of stellacyanin from the Japanese lacquer tree Rhus vernicifera, the most extensively studied and best characterized stellacyanin, indicating that this domain folds correctly, even in the absence of its carbohydrate moiety. The presence of a hydroxyproline- and serine-rich domain III suggests that stellacyanin may have a function other than that of a diffusible electron transfer protein, conceivably participating in redox reactions localized at the plant cell wall, which are known to occur in response to wounding or infection of the plant.

Molecular studies of CtpA, the carboxyl-terminal processing protease for the D1 protein of the photosystem II reaction center in higher plants.

The D1 reaction center protein of the Photosystem II complex in green plants is synthesized with a short carboxyl-terminal extension. Proteolytic cleavage and removal of this extension peptide in the thylakoid lumen are necessary for the assembly of a manganese cluster that is essential for the oxygen evolution activity of Photosystem II. We have isolated cDNAs encoding CtpA, the carboxyl-terminal processing protease for the D1 protein, from two higher plants, spinach and barley. In each of these organisms, CtpA is encoded by a single copy nuclear gene, and its steady-state mRNA levels are light-regulated. The CtpA protein is detectable in etiolated material, and its level increases approximately 5-fold upon illumination. Moreover, the CtpA gene is expressed in shoot tissues and not in roots. In its precursor form, the CtpA protein harbors a bipartite transit sequence characteristic for thylakoid lumenal proteins. Cell fractionation studies demonstrated that CtpA is associated with thylakoid membranes and is resistant to treatments with thermolysin, consistent with its localization in the lumen of thylakoids. Comparisons of the sequence of the higher plant CtpA enzyme with those of other related carboxyl-terminal processing proteases suggest that these proteins constitute a new family of proteases.

[Adjuvant treatment of colonic carcinoma]. / Adjuvante Behandlung des Kolonkarzinoms.

After many years of negative trials of adjuvant chemotherapy in colon cancer, two studies in the years 1989 and 1990 of the NCCTG and the Intergroup Trial, respectively showed a significant reduction of relapse and improved survival in patients treated with 5-FU and levamisole in an adjuvant setting. The absolute and relative reductions in 5-year-relapse and death rates were approximately 35% and 17%, respectively. Intraportal perfusion of the liver in an adjuvant perioperative setting seems to be of similar benefit. Preliminary data of the adjuvant therapy with 5-FU and folinic acid also show that this combination seems to have at least the same efficacy as the current standard 5-FU/levamisole in the adjuvant therapy of colon cancer. At the current time, patients with colon cancer of Dukes stage C should be offered adjuvant chemotherapy with 5-FU/levamisole outside of clinical studies.

A plant lectin derived from Viscum album induces cytokine gene expression and protein production in cultures of human peripheral blood mononuclear cells.

A plant lectin from Viscum album (ML-I) has been shown to increase the number and cytotoxic activity of natural killer cells and to induce antitumor activity in animal models. However, the mechanisms underlying the effects of ML-I on natural host defenses are unknown. After 24 h incubation of peripheral blood mononuclear cells in the presence of 10 and 1 ng/ml of ML-I, mRNA expression and secretion of a panel of cytokines were evaluated by reverse polymerase chain reaction and by ELISA, respectively. The lectin induced expression of interleukin (IL)-1 alpha, IL-1 beta, IL-6, tumor necrosis factor-alpha, interferon-gamma, granulocyte-monocyte colony-stimulating factor and IL-10 genes but no expression of IL-2 and IL-5 genes could be detected. Regarding cytokine secretion, IL-6 and TNF-alpha production was induced by 10 ng/ml ML-I. On the other hand, IL-10 secretion was only stimulated by 1 ng/ml lectin. No production of IFN-gamma or, as expectable, IL-2 could be detected. In addition, ML-I increased the percentage of HLA-DR+ T lymphocytes in vitro. In tests performed on whole blood, monocytes and granulocytes bound the fluorescence-conjugated ML-I molecules to a higher degree than lymphocytes. Expression of IL-1 beta and IFN-gamma genes could also be observed upon ML-I stimulation of nonadherent cells. These results suggest that lectin-sugar interactions on the cell surface of immunocompetent cells can induce cytokine gene expression and protein synthesis.

Effects of omega-3 fatty acids on intravascular lipolysis of very-low-density lipoproteins in humans.

Very-low-density lipoproteins (VLDLs) are the major carriers of fasting plasma triglyceride (TG). TG-enriched VLDLs become cholesterol (C)-enriched low-density lipoproteins (LDLs) through hydrolysis facilitated by lipoprotein lipase (LPL). Omega-3 fatty acid (n-3 FA) supplementation may increase LDL-C while decreasing plasma TG in hypertriglyceridemic patients. It has been proposed that n-3 FAs increase LDL-C by promoting production of TG-poor VLDL and accelerating conversion of VLDL to LDL. To study the effects of n-3 FA supplementation on in vivo lipolysis of VLDL directly, we treated 11 hypertriglyceridemic subjects with n-3 FA (3.3 g/d). Each participant was studied three times: at baseline, after a 1-month period of run-in olive oil placebo, and after 1 more month of n-3 FA supplementation. Lipolysis was induced by intravenous infusion of heparin for 2 hours. Plasma samples were obtained every 30 minutes for determination of lipids and apoproteins (apos), separation of individual lipoproteins by fast protein liquid chromatography (FPLC), and measurement of LPL and hepatic TG lipase (HTGL) levels. n-3 FA supplementation decreased fasting plasma TG (2.51 +/- 0.23 v 3.97 +/- 0.46 mmol/L), VLDL-TG (1.08 +/- 0.18 v 2.35 +/- 0.35 mmol/L), and VLDL-C (0.39 +/- 0.05 v 0.72 +/- 0.13 mmol/L) while increasing LDL-C (3.59 +/- 0.21 v 3.00 +/- 0.23 mmol/L) and plasma apo B (3.31 +/- 0.19 v 2.90 +/- 0.17 mmol/L). The absolute rate of TG lipolysis correlated with fasting TG (r = .74, P < .005) and was lower after n-3 FA supplementation (0.11 +/- 0.01 mmol/mL/min) as compared with placebo (0.19 +/- 0.01, P < .01), whereas percent decreases from baseline TG levels were similar at entry onto the study (57.4% +/- 2.5%), after placebo (58.8% +/- 2.7%), and after n-3 FA (52% +/- 3.6%).(ABSTRACT TRUNCATED AT 250 WORDS)

Iron deficiency. Current trends and fads.

Anaemia due to iron deficiency remains the commonest form of anaemia world-wide, predominantly due to blood loss, either associated with infestations such as hook worm or menstrual blood loss, or malnutrition. In Australia, iron deficiency anaemia is the commonest form of anaemia and is seen in pregnant and breastfeeding females where the iron balance is often in a negative state. Fads and fallacies abound, particularly in this group. Despite extensive knowledge of iron metabolism, diagnosis of iron deficiency often remains a difficult problem. The use of diagnostic tests available is discussed in this article.

Mutations at the stromal processing peptidase cleavage site of a thylakoid lumen protein precursor affect the rate of processing but not the fidelity.

Nuclear-encoded stromal proteins are imported into the chloroplast by means of presequences, or transit peptides, which are removed after import by a stromal processing peptidase (SPP); the presequences of thylakoid lumen proteins are processed by SPP at intermediate sites prior to transport of these proteins across the thylakoid membrane. SPP has been previously shown to be a highly specific enzyme, but the basis for the reaction specificity is unclear, because the cleavage sites of different substrates display virtually no primary structure similarity. We have examined the influence of the cleavage site residues on the SPP reaction mechanism by introducing mutations at these positions (denoted -1 and +1, relative to the SPP cleavage site) within the presequence of the lumenal 33-kDa photosystem II protein. Substitution of the -1 Arg by Ala or Met leads to a 5-7-fold reduction in the rate of processing, whereas substitution by Glu almost completely blocks cleavage. The replacement of the +1 Ala by Lys likewise almost completely blocks cleavage. None of the introduced -1 mutations affect cleavage fidelity; we show that all three mutants are cleaved only at the correct site. All of the mutant precursors are efficiently imported into the thylakoid lumen of intact chloroplasts, indicating that this cleavage event is not an important element of the overall import pathway. The results indicate that the identity of the -1 residue, within the context of a given presequence, is important in terms of influencing processing efficiency, but that the site of cleavage is specified by other determinants. At least a proportion of the other determinants are likely to be in close proximity to the cleavage site, since the deletion of a 7-residue section spanning this site completely blocks processing.

Electron transfer from plastocyanin to photosystem I.

Mutant plastocyanins with Leu at position 10, 90 or 83 (Gly, Ala and Tyr respectively in wildtype) were constructed by site-specific mutagenesis of the spinach gene, and expressed in transgenic potato plants under the control of the authentic plastocyanin promoter, as well as in Escherichia coli as truncated precursor intermediates carrying the C-terminal 22 amino acid residues of the transit peptide, i.e. the thylakoid-targeting domain that acts as a bacterial export signal. The identity of the purified plastocyanins was verified by matrix-assisted laser desorption/ionization mass spectrometry. The formation of a complex between authentic or mutant spinach plastocyanin and isolated photosystem I and the electron transfer has been studied from the biphasic reduction kinetics of P700+ after excitation with laser flashes. The formation of the complex was abolished by the bulky hydrophobic group of Leu at the respective position of G10 or A90 which are part of the conserved flat hydrophobic surface around the copper ligand H87. The rate of electron transfer decreased by both mutations to < 20% of that found with wildtype plastocyanin. We conclude that the conserved flat surface of plastocyanin represents one of two crucial structural elements for both the docking at photosystem I and the efficient electron transfer via H87 to P700+. The Y83L mutant exhibited faster electron transfer to P700+ than did authentic plastocyanin. This proves that Y83 is not involved in electron transfer to P700 and suggests that electron transfer from cytochrome f and to P700 follows different routes in the plastocyanin molecule. Plastocyanin (Y83L) expressed in either E. coli or potato exhibited different isoelectric points and binding constants to photosystem I indicative of differences in the folding of the protein. The structure of the binding site at photosystem I and the mechanism of electron transfer are discussed.

Targeting of proteins to the thylakoids by bipartite presequences: CFoII is imported by a novel, third pathway.

The CFoII subunit of the ATP synthase is an integral component of the thylakoid membrane which is synthesized in the cytosol with a bipartite, lumen-targeting presequence similar in structural terms to those of imported lumenal proteins such as plastocyanin. This presequence is shown to possess a terminal cleavage site for the thylakoidal processing peptidase, but no intermediate site for the stromal processing peptidase. The integration of CFoII into the thylakoid membrane of Pisum sativum has been analysed using in vitro assays for the import of proteins into intact chloroplasts or isolated thylakoids. Efficient integration into thylakoids is observed in the light and dark, and the integration process does not require the presence of either stromal extracts or nucleoside triphosphates. The uncoupler nigericin inhibits integration only very slightly, indicating that the thylakoidal delta pH does not play a significant role in the integration mechanism. In each of these respects, the requirements for CFoII integration differ notably from those determined for integration of the light-harvesting chlorophyll-binding protein of photosystem II. The integration mechanism also differs significantly from the two mechanisms involved in the translocation of lumenal proteins across the thylakoid membrane, since one of these processes requires the presence of stromal protein factors and ATP, and the other mechanism is dependent on the thylakoidal delta pH. This conclusion is reinforced by the finding that saturation of the translocation system for the precursor to the lumenal 23 kDa oxygen-evolving complex protein does not affect integration of CFoII into thylakoids.(ABSTRACT TRUNCATED AT 250 WORDS)

The presequence of a chimeric construct dictates which of two mechanisms are utilized for translocation across the thylakoid membrane: evidence for the existence of two distinct translocation systems.

The translocation of plastocyanin across the thylakoid membrane in Pisum sativum has been studied in reconstitution assays and using chimeric constructs. The reconstitution assays demonstrate that plastocyanin translocation is absolutely dependent on the presence of a stromal factor(s) and nucleotide triphosphates (NTPs), whereas neither element is required for the translocation of the 23 or 16 kDa proteins of the oxygen-evolving complex. Previous studies had revealed that the transthylakoidal delta pH is essential for translocation of the 23 and 16 kDa proteins but unnecessary for plastocyanin translocation. The basis for these mechanistic differences has been tested by analysing the translocation of a chimeric construct consisting of the presequence of the 23 kDa protein linked to the mature plastocyanin sequence. This construct is efficiently imported into thylakoids in the absence of stromal extracts or NTPs and translocation across the thylakoid membrane within intact chloroplasts is totally inhibited by the uncoupler nigericin: the translocation requirements are thus identical to those of the pre-23 kDa protein and diametrically opposite to those of pre-plastocyanin. Transport across the thylakoid membrane of a second fusion protein, consisting of the presequence of the 16 kDa protein linked to mature plastocyanin, is also dependent on a delta pH. The data suggest that two distinct systems are involved in the translocation of proteins across the thylakoid membrane, with each system recognizing specific signals within the presequences of a subset of lumenal protein precursors.

Microcirculatory effects of hyperthermia and 5-fluorouracil in the skin of nude mice.

During cancer chemotherapy physical manipulation of skin perfusion by hyperthermia can limit therapeutic efficacy. Because it is important to know microcirculatory responses to those forms of treatment, we used the ear of the lightly or not at all anesthetized nude mouse (rnü/rnü). To test, if whole body hyperthermia (WBH) and 5-fluorouracil (5-FU) acutely affect skin microvessels, we applied red light (group 1). 5-FU was injected prior to WBH, to test for effects of 5-FU on WBH (group 2). Respiratory rate increased and medium sized and small arterioles constricted during WBH in both groups and cutaneous perfusion decreased. 5-FU did not change these results. There were more leucocytes rolling along the vessel wall of small and medium-sized venules after 5-FU treatment (compared to BL). Our data suggest that activation of sympathetic tone by an external heat source compromises skin perfusion and could decrease the amount of cytostatic agents to that organ during WBH. Finally, there is more intense interaction among leucocytes and endothelial cells omit in response to 5-FU.