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Biomedical subjects

D C Carter

Publications and source records attributed to D C Carter.

At least 19 recordsLinked to original sources
PubMed1998

Glutamine-supplemented total parenteral nutrition reduces blood mononuclear cell interleukin-8 release in severe acute pancreatitis.

Glutamine, a conditionally essential amino acid, is important for immune function. It is now being formulated for incorporation into total parenteral nutrition (TPN). The aims of this study were to examine the effect of glutamine administration on lymphocyte proliferation and proinflammatory cytokine release in patients with severe acute pancreatitis. Fourteen patients were randomized (in a double-blind fashion) to receive either conventional or isocaloric, isonitrogenous glutamine-supplemented (0.22 g glutamine x kg(-1) x d(-1) as glycyl-glutamine) TPN for 7 d. DNA synthesis (index of lymphocyte proliferation) and the 24-h release of tumor necrosis factor (TNF), interleukin (IL)-6, and IL-8 from peripheral blood mononuclear cells were measured in vitro on days 0, 4, and 7. Thirteen patients completed the study protocol (6 glutamine TPN, 7 conventional TPN). Glutamine supplementation increased median DNA synthesis by 3099 cpm over the study period against 219 cpm in the conventional group (increase not significantly different between the two groups) . Glutamine supplementation did not significantly influence TNF or IL-6 release, but, in contrast, median IL-8 release was reduced by day 7 in the glutamine group while it was increased in the conventional group (-17.7 ng/mL (median change over study period) versus +43.3 ng/mL, respectively; P=0.045). Small patient numbers and substantial interindividual variation limit the conclusions, but there is a trend for the glutamine group to have improved lymphocyte proliferation, and in the case of IL-8, reduced proinflammatory cytokine release.

Adult↗
PubMed1996

Serum concentrations of inflammatory mediators related to organ failure in patients with acute pancreatitis.

Leucocyte activation and proinflammatory cytokine release (tumour necrosis factor (TNF) and interleukin 6 (IL-6)) are thought to contribute to the induction of a systemic inflammatory response, an acute-phase response and multiple organ failure in patients with acute pancreatitis. The serum concentration of TNF, soluble TNF receptors (sTNFR55 and sTNFR75), IL-6 and C-reative protein (CRP) in 58 patients with acute pancreatitis was assessed during the first 2 days of admission. Thirty patients had mild disease and 28 severe disease, of whom 18 developed local pancreatic complications alone (Atlanta classification) and ten developed organ failure (a Goris score of 1 or more). TNF was detected in only 17 patients on the first day of admission, while soluble TNF receptors were detected in all patients and IL-6 in 34. On the first and second days of admission there was a progressive and significant (P < 0.03) increase in the median concentration of sTNFR55, sTNFR75 and IL-6 in patients eventually classified into those with mild disease, a local pancreatic complication alone, or organ failure. This pattern was also evident in CRP levels from the second but not the first day of admission. These findings suggest that proinflammatory cytokines or their soluble receptors may be more accurate early predictors of outcome than CRP, Moreover, markers of inflammation in the sera of patients with acute pancreatitis are highest in those who subsequently develop organ failure.

Acute Disease↗
PubMed1996

Proinflammatory cytokine release by peripheral blood mononuclear cells from patients with acute pancreatitis.

Proinflammatory cytokine release was measured from peripheral blood mononuclear cells (PBMCs) isolated from six volunteers and, on admission, from 16 patients with acute pancreatitis. Tumour necrosis factor (TNF) release in patients did not differ significantly from that of volunteers, whereas both interleukin (IL) 6 and IL-8 release in patients was raised when compared with that in the volunteer group (mean(s.e.m.) IL-6 20.7(4.6) versus 9.3(1.7) ng/ml, P = 0.03; IL-8 283(40) versus 128(22) ng/ml, P = 0.04). When variation in white cell count was accounted for, IL-6 and IL-8 release but not that of TNF was significantly greater in patients with severe disease than in those with mild disease. These results point to a complex upregulation of proinflammatory cytokine release from PBMCs in patients with acute pancreatitis, components of which relate to the clinical progress of the disease.

Acute Disease↗
PubMed1996

The effect of polyunsaturated fatty acids on the progress of cachexia in patients with pancreatic cancer.

Cachexia is common in patients with pancreatic cancer and has been associated with persistent activation of the hepatic acute phase response and increased energy expenditure. Fatty acids have been shown to have anticachectic effects in animal models and to reduce inflammatory mediators in healthy subjects and patients with chronic inflammatory disease. Eighteen patients with unresectable pancreatic cancer received dietary supplementation orally with fish oil capsules (1 g each) containing eicosapentaenoic acid 18% and docosahexaenoic acid 12%. Anthropometric measurement, body composition analysis, and measurement of resting energy expenditure and serum C-reactive protein were performed before and after supplementation with a median of 12 g/day of fish oil. Patients had a median weight loss of 2.9 kg/month (IQR 2-4.6) prior to supplementation. At a median of 3 months after commencement of fish oil supplementation, patients had a median weight gain of 0.3 kg/month (IQR 0-0.5) (p < 0.002). Changes in weight were accompanied by a temporary but significant reduction in acute phase protein production (p < 0.002) and by stabilisation of resting energy expenditure. This study suggests a component fish oil, perhaps EPA, merits further investigation in the treatment of cancer cachexia.

Acute-Phase Proteins↗
PubMed1996

Cell cycle arrest and induction of apoptosis in pancreatic cancer cells exposed to eicosapentaenoic acid in vitro.

Eicosapentaenoic acid (EPA) has been shown to have an inhibitory effect on the growth of several pancreatic cancer cell lines in vitro. This study investigates the mechanism of growth inhibition and cytotoxicity of EPA on the pancreatic cancer cell line MIA PaCa-2. Cells were analysed for cell count, viability, cell cycle distribution and ultrastructural changes. There was a time- and dose-dependent decrease in cell count and viability in cultures of pancreatic cancer cells supplemented with EPA. Flow cytometric DNA analysis of MIA PaCa-2 cells incubated with EPA demonstrated the presence of sub G1 populations corresponding to the presence of apoptotic cells and the blockade of cell cycle progression in S-phase and G2/M-phase. The presence of apoptosis in EPA-supplemented cultures was further confirmed by DNA fragmentation and ultrastructural changes associated with apoptosis. Therefore, we conclude that EPA mediates its effect on the pancreatic cancer cell line MIA PaCa-2, at least in part, via cell cycle arrest and the induction of apoptosis.

Antineoplastic Agents↗
PubMed1996

Extracolonic features of familial adenomatous polyposis in patients with sporadic colorectal cancer.

We have investigated the occurrence of attenuated extracolonic manifestations (AEMs) of familial adenomatous polyposis (FAP) in patients with non-polyposis colorectal cancer. In a prospective case-control study, we observed that significantly more colorectal cancer patients exhibited AEM than did age and sex-matched controls (19.5% vs 7.5%, P < 0.004). However patients with AEMs do not have occult FAP, as we found no heterozygous adenomatous polyposis coli (APC) gene mutations despite extensive analysis of constitutional DNA. Genome-wide DNA replication errors (RERs) occur in a proportion of colorectal cancers, particularly right-sided lesions and in almost all tumours from hereditary non-polyposis colorectal cancer (HNPCC) patients. As AEMs have been reported in familial colon cancer cases, we investigated the relationship of AEMs to tumour RER phenotype. There was indeed an excess of AEMs in patients with right-sided tumours (30.2% of 53 patients vs 14.7% of 116 patients, P < 0.03) and in those with RER tumours (3 out of 12 patients with RER tumours vs none out of 21 patients with non-RER tumours, P < 0.05). Two patients with AEM were from HNPCC families compared with none of those without AEM (P < 0.05). The association of AEMs with colorectal cancer is intriguing, and we speculate that it may be a manifestation of mutational mosaicism of the APC gene, perhaps associated with a constitutional defect in DNA mismatch pair.

Adenomatous Polyposis Coli↗
PubMed1996

Metabolic disturbance and sensitivity to endotoxin in patients with advanced cancer: relationship to lymphocyte reactivity, tumour necrosis factor (TNF) production and survival.

Increased TNF production and impaired lymphocyte function have been individually linked with metabolic disturbance, endotoxaemia and mortality in humans. The inter-relationship between these observations was investigated in humans with cancer. In 13 patients with metastatic colorectal cancer and seven healthy volunteers, observations (n = 23) included peripheral blood mononuclear cell (PBMC) TNF production, IL-2 production and phytohaemagglutinin (PHA) response; the acute-phase protein response (APPR) (serum C-reactive protein (CRP), albumin, CRP/albumin ratio), and survival. APPR correlated with survival (CRP, r = -0.689, P = 0.006; CRP/albumin, r = -0.758, P = 0.002; albumin, r = 0.655, P = 0.011), but not with TNF production. TNF production in response to in vitro endotoxin correlated with impaired lymphocyte function in patients (r = 0.567, P = 0.043) and in the whole group (r = 0.65, P = 0.001). The ratio (basal PBMC TNF production)/(lymphocyte function) correlated with CRP (r = 0.569, P = 0.042), CRP/albumin (r = 0.617, P = 0.025), endotoxin sensitivity (r = 0.567, P = 0.043) and survival (r = -0.545, P = 0.038) in patients, and the whole group (P < 0.002). Impaired lymphocyte function may influence TNF production, endotoxin sensitivity and metabolic disturbance in humans with cancer. (r = Spearman correlation coefficient.)

Adult↗
PubMed1996

Report on consensus conference on colorectal cancer: Royal College of Surgeons of Edinburgh 1993.

Colorectal cancer is the second commonest cause of death from cancer in Scotland. Recent developments in molecular biology, pre-symptomatic diagnosis, surgery and adjuvant treatment suggest that a substantial reduction in mortality is achievable. Some fear that major changes to the organisation of the NHS could undermine future attempts to coordinate major cancer screening studies or multicentre adjuvant trials. In contrast, others argue that a sharp focus on cost and benefits could encourage the development of clear guidelines based on a consensus of good practice. Thus, the time seems right for a consensus conference and this article summarises the outcome of such a recent conference held in Scotland. A group of 80 surgeons, radiation oncologists and medical oncologists were invited as a representative cross-section of clinicians with an interest in colorectal cancer. Seventy per cent of those attending were surgeons. A series of expert presentations were used to lead discussion in four sessions devoted respectively to epidemiology and screening, influence of surgical factors and outcome, the role of adjuvant therapy and planning for the future. Full discussion from delegates was encouraged and computer-collated, key-pad responses allowed documentation of the opinions of the audience in respect of pre-defined questions. For statistical purposes we have assumed that a consensus had been reached when there was a statistically significant difference (Chi-square) between the observed response from clinicians and the null hypothesis, i.e. a 50/50 split.

Aftercare↗
PubMed1995

Acute-phase protein response and survival duration of patients with pancreatic cancer.

BACKGROUND: Current methods to predict survival duration of patients with pancreatic cancer are limited. The aim of this study was to determine whether certain nutritional indices and the acute-phase protein response are prognostic factors independent of disease stage for patients with unresectable pancreatic cancer. METHODS: Variables at the time of diagnosis of 102 patients with unresectable pancreatic cancer were entered into a Cox's proportional hazards model. Included in the analysis were the serum concentration of C-reactive protein (CRP) and albumin, the extent of weight loss, age, sex, and disease stage (International Union Against Cancer criteria). RESULTS: A multivariate analysis in which each factor was adjusted for the influence of the other factors revealed the patient age, disease stage, serum albumin, and serum CRP to be independent predictors of survival. The presence of an acute-phase protein response was the most significant independent predictors of survival duration. The median survival of those with an acute-phase protein response (CRP > 10 mg/L, n = 45) was 66 days compared with 222 days for those with no acute-phase protein response (n = 57, P = 0.001, Mann-Whitney U test). CONCLUSION: The acute-phase protein response is a useful prognostic indicator for patients with unresectable pancreatic cancer. Moreover, the metabolic disturbances associated with an acute-phase protein response of patients with pancreatic cancer may be a worthwhile therapeutic target.

Acute-Phase Proteins↗
PubMed1995

Effect of ibuprofen on the acute-phase response and protein metabolism in patients with cancer and weight loss.

The aim of this study was to determine whether administration of the non-steroidal anti-inflammatory agent ibuprofen might attenuate the acute-phase response in patients with colonic cancer. Cytokines and acute-phase proteins were measured before administration of ibuprofen and again 3 days later, when protein synthesis was measured using 15N-glycine. In patients with cancer, ibuprofen caused a significant reduction in the plasma concentration of all five acute-phase proteins studied. Although interleukin 6 levels were raised, they did not change following administration of ibuprofen. Unlike the situation in patients with cancer who did not receive ibuprofen, whole-body protein kinetics were similar to those of control subjects in patients with cancer who received ibuprofen. Whether or not ibuprofen had been administered, non-export hepatic protein synthesis rates were significantly lower in patients with than in those without cancer. These results suggest that short-term administration of ibuprofen can attenuate accelerated whole-body protein kinetics and the acute-phase response in patients with advanced cancer.

Acute-Phase Proteins↗
PubMed1995

Ibuprofen reduces energy expenditure and acute-phase protein production compared with placebo in pancreatic cancer patients.

The aim of this study was to investigate the effect of the cyclo-oxygenase inhibitor ibuprofen on the acute-phase protein response and resting energy expenditure (REE) of weight-losing patients with pancreatic cancer. Patients with irresectable pancreatic cancer (n = 16) were treated with either ibuprofen (1200 mg day-1 for 7 days (n = 10) or placebo (n = 6). A group of 17 age-related non-cancer subjects were also studied. Indirect calorimetry, anthropometry, multifrequency bioelectrical impedence analysis and serum C-reactive protein (CRP) estimation were performed immediately before and after treatment. Before treatment, total REE was significantly elevated in the pancreatic cancer patients compared with healthy controls (1499 +/- 71 vs 1377 +/- 58 kcal) (P < 0.02). Following treatment the mean REE of the ibuprofen group fell significantly (1386 +/- 89 kcal) compared with pretreatment values (1468 +/- 99 kcal) (P < 0.02), whereas no change was observed in the placebo group. Serum CRP concentration was also reduced in the ibuprofen-treated group (pre-ibuprofen, 51 mg l-1; post-ibuprofen, 29 mg l-1; P < 0.05). These results suggest that ibuprofen may have a role in abrogating the catabolic processes which contribute to weight loss in patients with pancreatic cancer.

Acute-Phase Proteins↗
PubMed1995

Interleukin-4 and interleukin-10 increase endotoxin-stimulated human umbilical vein endothelial cell interleukin-8 release.

The aim of this study was to determine the effect of interleukin-4 (IL-4) and interleukin-10 (IL-10) on interleukin-8 (IL-8) release from endothelial cells. Confluent monolayers of human umbilical vein endothelial cells (HUVECs) were incubated in the absence or presence of 10 ng/ml of bacterial lipopolysaccharide (LPS), with 5% human AB serum and recombinant human IL-4 or IL-10 over a dose range from 50 fg/ml to 50 ng/ml (final concentration). IL-4 and IL-10 had no effect on HUVEC IL-8 release in the absence of LPS. In the presence of LPS, IL-4 and IL-10 enhanced IL-8 release by approximately 300% compared with LPS-stimulated cells alone, IL-8 release increasing from 2594 +/- 493 pg/ml (no IL-4 or IL-10) to 7892 +/- 320 pg/ml (IL-4, 5 pg/ml; p = 0.001) and 8359 +/- 712 pg/ml (IL-10, 50 pg/ml; p = 0.002). IL-8 release in response to IL-4 or IL-10 plateaued above 5 and 50 pg/ml, respectively. This study suggests that IL-4 and IL-10 may be involved in the complex regulation of endothelial cell cytokine production during the response to endotoxin.

Cells, Cultured↗
PubMed1995

Interaction between a Fab fragment against gp41 of human immunodeficiency virus 1 and its peptide epitope: characterization using a peptide epitope library and molecular modeling.

The molecular interaction of the Fab fragment of the human monoclonal antibody 3D6, directed against the transmembrane protein gp41 of human immunodeficiency virus (HIV) 1, with its peptide epitope is characterized by a panel of overlapping peptides, a peptide epitope library and molecular modeling techniques. The sequence CSGKLICTTAVPW, corresponding to amino acids 605-617 of gp41, was identified as the best binding peptide (KD = 1 x 10(-8) mol/l). This peptide served as a starting point to prepare a cellulose-bound peptide epitope library in which each residue of the epitope is substituted by all L- and D-amino acids, resulting in 494 epitope peptide variants which were subsequently analyzed for binding 3D6. The library was synthesized to identify residues critical for binding and to obtain information about the molecular environment of the epitope peptide bound to 3D6. Both cysteine residues, as well as isoleucine 6, threonine 8 and proline 12, of the epitope were highly sensitive to substitution. Using the data obtained from the epitope characterization, as well as a low-resolution electron density map of a 3D6 Fab-peptide complex, a 3-D model of the Fab-peptide complex was generated by molecular modeling. The modeling experiments predict binding of the peptide, which is cyclized via the two cysteine residues, to a pocket formed dominantly by the hypervariable loops complementarity determining regions CDR3L, CDR2H and CDR3H.

Amino Acid Sequence↗