Uric acid and oxidative stress.

Uric acid is the final product of purine metabolism in humans. The final two reactions of its production catalyzing the conversion of hypoxanthine to xanthine and the latter to uric acid are catalysed by the enzyme xanthine oxidoreductase, which may attain two inter-convertible forms, namely xanthine dehydrogenase or xanthine oxidase. The latter uses molecular oxygen as electron acceptor and generates superoxide anion and other reactive oxygen products. The role of uric acid in conditions associated with oxidative stress is not entirely clear. Evidence mainly based on epidemiological studies suggests that increased serum levels of uric acid are a risk factor for cardiovascular disease where oxidative stress plays an important pathophysiological role. Also, allopurinol, a xanthine oxidoreductase inhibitor that lowers serum levels of uric acid exerts protective effects in situations associated with oxidative stress (e.g. ischaemia-reperfusion injury, cardiovascular disease). However, there is increasing experimental and clinical evidence showing that uric acid has an important role in vivo as an antioxidant. This review presents the current evidence regarding the antioxidant role of uric acid and suggests that it has an important role as an oxidative stress marker and a potential therapeutic role as an antioxidant. Further well designed clinical studies are needed to clarify the potential use of uric acid (or uric acid precursors) in diseases associated with oxidative stress.

Circulating endothelial cells are elevated in patients with type 2 diabetes mellitus independently of HbA(1)c.

AIMS/HYPOTHESIS: Patients with diabetes mellitus are well known to be at high risk for vascular disease. Circulating endothelial cells (CECs) have been reported to be an ex vivo indicator of vascular injury. We investigated the presence of CECs in the peripheral blood of 25 patients with diabetes mellitus and in nine non-diabetic control donors. METHODS: Endothelial cells were isolated from peripheral blood with anti-CD-146-coated immunomagnetic Dynabeads, and were stained with acridine orange dye and counted by fluorescence microscopy. The cells were also stained for von Willebrand factor and Ulex europaeus lectin 1. RESULTS: Patients with diabetes mellitus had an elevated number of CECs (mean 69+/-30 cells/ml, range 35-126) compared with healthy controls (mean 10+/-5 cells/ml, range 3-18) (p<0.001). The increase in CECs did not correlate with the levels of HbA(1)c. Circulating endothelial cell numbers were elevated regardless of glucose levels, suggesting that, even with control of glucose levels, there is increased endothelial cell sloughing. CONCLUSIONS: Our study suggests that the higher number of CECs in patients with type 2 diabetes may reflect ongoing vascular injury that is not directly dependent on glucose control.

A fatal case of sclerosing mesenteritis.

A 22-year-old patient was admitted because of abdominal pain and vomiting. Computed tomography diagnosed small intestinal malignancy. Ileal resection was performed, and the histological findings were consistent with sclerosing mesenteritis. The patient was treated with enteral nutrition, corticosteroids, azathioprine and methotrexate, but died 2 years later.

Assessment of local stage in rectal cancer using endorectal ultrasonography (EUS).

BACKGROUND: Preoperative staging of rectal cancer is essential for the selection of the optimal treatment. This study aims to evaluate the accuracy of endorectal ultrasonography (EUS) in local staging of rectal cancer. PATIENTS AND METHODS: During a 4-year period, 33 patients with biopsy-proven rectal cancer underwent evaluation of the invasion of the rectal wall, the mesorectal lymph nodes status and the pelvic organs using EUS. We compared the EUS findings (uTN) to the histopathology examination of the resected specimens (pTN) according to TNM classification. RESULTS: Most patients had T3 tumours. Overall accuracy in assessing the depth of rectal wall invasion (T) and the lymph node status was 79% and 59% respectively. Two patients previously treated by preoperative chemoradiation were correctly staged only for N stage. CONCLUSIONS: EUS is a valuable diagnostic tool in local staging of rectal cancer. Progressively increasing experience will overcome the obstacles in accurate interpretation of ultrasound images.

Human heme oxygenase: cell cycle-dependent expression and DNA microarray identification of multiple gene responses after transduction of endothelial cells.

The purpose of the present study was to examine the role of human heme oxygenase (human HO-1) in cell cycle progression following exposure to heme or human HO-1 gene transfer and to identify target genes associated with human HO-1-meditated increases in cell cycle progression using cDNA microarray technology. Heme-induced robust human HO-1 expression in quiescent human microvessel endothelial cells cultured in 1% FBS and the levels of human HO-1 expression progressively declined without a change in the cell cyclin. To identify genes regulated by human HO-1 in the cell cycle, human endothelial cells were transduced with a retroviral vector encoded with human HO-1 gene or an empty vector. Transgene expression and functionality of the recombinant protein were assessed by Western blotting, enzyme activity, carbon monoxide, cGMP production, and cell cycle analysis. Human cDNA gene array and quantitative real-time RT-PCR were used to identify both known and novel differentially expressed genes in cells overexpressing human HO-1. Major findings were upregulation of several genes associated with cell cycle progression, including cyclin E and D; downregulation of cyclin-dependent kinase inhibitors p21 and p27, cyclin-dependent kinases 2, 5, and 6, and monocyte chemoattractant protein-1; and upregulation of growth factors, including vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor I (VEGFRI), endothelial growth factor (EGF) and hepatic-derived growth factor (HDGF). These findings identify an array of gene responses to overexpression of human HO-1 and elucidate new aspects of human HO-1 signaling involved in cell growth.

Laparoscopic surgery-induced changes in oxidative stress markers in human plasma.

BACKGROUND: The induction of the pneumoperitoneum increases intraabdominal pressure (IAP), causing splanchnic ischemia, whereas its deflation normalizes IAP and splanchnic blood flow. This procedure appears to represent an ischemia-reperfusion model in humans. METHODS: Thirty laparoscopic cholecystectomies (LC) were performed in 30 patients with a mean age of 54.6 +/- 15.6 years. A group of 20 patients mean age, 57.3 +/- 9.65 who underwent open cholecystectomy (OC) was also studied. Vein plasma levels of thiobarbituric acid-reactive substances (TBARS), a marker of free radical production; plasma total antioxidant status (TAS); and uric acid (UA) levels were measured preoperatively, 5 min after deflation of the pneumoperitoneum or at the end of operation, and 24 h postoperatively. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (TBL) levels were measured preoperatively and 24 h after the operation. RESULTS: In the LC group, significant elevations in the concentration of TBARS were observed in the early postoperative measurements in comparison with the preoperative measurements. TAS and UA levels were decreased significantly 24 h postoperatively compared to preoperative levels. The postoperative levels of AST, ALT, and TBL increased significantly in comparison with the preoperative levels. In the OC group, no alterations in the concentration of TBARS were observed in the postoperative period. The other parameters had changes similar to those recorded for the LC group. CONCLUSIONS: Free radical-induced lipid peroxidation associated with a decrease in plasma antioxidant capacity and UA levels as well as altered hepatic function is observed after deflation of the pneumoperitoneum. These results suggest that free radicals are generated at the end of a laparoscopic procedure, possibly as a result of an ischemia-reperfusion phenomenon induced by the inflation and deflation of the pneumoperitoneum.

Regulation of human heme oxygenase in endothelial cells by using sense and antisense retroviral constructs.

Our objective was to determine whether overexpression and underexpression of human heme oxygenase (HHO)-1 could be controlled on a long-term basis by introduction of the HO-1 gene in sense (S) and antisense (AS) orientation with an appropriate vector into endothelial cells. Retroviral vector (LXSN) containing viral long terminal repeat promoter-driven human HO-1 S (LSN-HHO-1) and LXSN vectors containing HHO-1 promoter (HOP)-controlled HHO-1 S and AS (LSN-HOP-HHO-1 and LSN-HOP-HHO-1-AS) sequences were constructed and used to transfect rat lung microvessel endothelial cells (RLMV cells) and human dermal microvessel endothelial cells (HMEC-1 cells). RLMV cells transduced with HHO-1 S expressed human HO-1 mRNA and HO-1 protein associated with elevation in total HO activity compared with nontransduced cells. Vector-mediated expression of HHO-1 S or AS under control of HOP resulted in effective production of HO-1 or blocked induction of endogenous human HO-1 in HMEC-1 cells, respectively. Overexpression of HO-1 AS was associated with a long-term decrease (45%) of endogenous HO-1 protein and an increase (167%) in unmetabolized exogenous heme in HMEC-1 cells. Carbon monoxide (CO) production in HO-1 S- or AS-transduced HMEC-1 cells after heme treatment was increased (159%) or decreased (50%), respectively, compared with nontransduced cells. HO-2 protein levels did not change. These findings demonstrate that HHO-1 S and AS retroviral constructs are functional in enhancing and reducing HO activity, respectively, and thus can be used to regulate cellular heme levels, the activity of heme-dependent enzymes, and the rate of heme catabolism to CO and bilirubin.

Human heme oxygenase-1 gene transfer lowers blood pressure and promotes growth in spontaneously hypertensive rats.

Heme oxygenase (HO) catalyzes the conversion of heme to biliverdin, with release of free iron and carbon monoxide. Both heme and carbon monoxide have been implicated in the regulation of vascular tone. A retroviral vector containing human HO-1 cDNA (LSN-HHO-1) was constructed and subjected to purification and concentration of the viral particles to achieve 5x10(9) to 1x10(10) colony-forming units per milliliter. The ability of concentrated infectious viral particles to express human HO-1 (HHO-1) in vivo was tested. A single intracardiac injection of the concentrated infectious viral particles (expressing HHO-1) to 5-day-old spontaneously hypertensive rats resulted in functional expression of the HHO-1 gene and attenuation of the development of hypertension. Rats expressing HHO-1 showed a significant decrease in urinary excretion of a vasoconstrictor arachidonic acid metabolite and a reduction in myogenic responses to increased intraluminal pressure in isolated arterioles. Unexpectedly, HHO-1 chimeric rats showed a simultaneous significant proportionate increase in somatic growth. Thus, delivery of HHO-1 gene by retroviral vector attenuates the development of hypertension and promotes body growth in spontaneously hypertensive rats.

Manometric study in Kearns-Sayre syndrome.

Although swallowing difficulties have been described in patients with Kearns-Sayre syndrome (KSS), the spectrum of manometric characteristics of dysphagia is not yet well known. Moreover, it is conceivable that a combination of various degrees of swallowing difficulties with different patterns in manometric studies exist, each playing a major role in the prognosis, natural history, and quality of life of KSS patients. An 18-year-old girl diagnosed at the age of 5 years with KSS (muscle biopsy) was admitted to our department with an upper respiratory tract infection and dysphagia. Clinical examination revealed growth retardation, external ophthalmoplegia, pigmentary retinopathy, impaired hearing, and ataxia. An electrocardiogram revealed cardiac conduction defects (long Q-T), and brain magnetic resonance imaging showed abnormalities in the cerebellar hemispheres. A manometric and motility study for dysphagia was conducted and the pharynx and upper esophageal sphincter (UES) resting pressures were similar to control group values, but the swallowing peak contraction pressure of the pharynx and the closing pressure of the UES were very low and could not promote effective peristaltic waves. Relaxation and coordination of the UES were not affected although pharyngeal and upper esophagus peristaltic waves proved to be very low and, consequently, were practically ineffective. The patient was started on treatment comprising a diet rich in potassium, magnesium, and calcium, and oral administration of vitamin D and co-enzyme Q10 100 mg daily; she was discharged 6 days later with apparent clinical improvement.

Heterotopic gastric mucosa together with intestinal metaplasia and moderate dysplasia in the gall bladder: report of two clinically unusual cases with literature review.

We report the clinicopathological findings of two patients with ectopic gastric mucosa within the gall ladder. The first patient, a 78 year old man, was asymptomatic. He was admitted to hospital for a colon adenocarcinoma. Intraoperatively, a firm nodule was palpable in the gall bladder. Histological examination of the resected specimen revealed a body type gastric mucosa in the submucosa, adjacent to which were extensive pyloric gland and intestinal metaplasia with mild to moderate dysplasia. The remaining gall bladder mucosa demonstrated changes of chronic cholecystitis. The second patient was a 62 year old woman with symptoms of chronic cholecystitis. The preoperative diagnosis was consistent with this diagnosis with a "polyp" at the junction of the neck and cystic duct. Cholecystectomy was performed and the histological examination of the resected specimen showed that the "polyp" consisted of heterotopic gastric mucosa with glands of body and fundus type. In the remaining mucosa, chronic cholecystitis was evident. To the best of our knowledge, this is the first report of a clinicopathological presentation of heterotopic gastric mucosa, pyloric gland type, and intestinal metaplasia with dysplastic changes in the gall bladder. As heterotopic tissue may promote carcinogenesis of the gall bladder, close attention should be paid to any occurrence of such lesions in this anatomical region.

Mesenteric injury after blunt abdominal trauma.

OBJECTIVE: To present our experience of mesenteric injuries after blunt abdominal trauma. DESIGN: Retrospective study. SETTING: University hospital, Greece. SUBJECTS: 31 patients with mesenteric injuries out of 333 who required operations for blunt abdominal trauma between March 1978 and March 1998. 21 were diagnosed within 6 hours (median 160 min, early group) and in 10 the diagnosis was delayed (median 21 hours, range 15 hours-7 days, delayed group). INTERVENTIONS: Emergency laparotomy. MAIN OUTCOME MEASURES: Mortality, morbidity, and hospital stay. RESULTS: There were no deaths. The diagnosis was confirmed by diagnostic peritoneal lavage in 17/21 patients in the early group whereas 7/10 in the delayed group were diagnosed by clinical examination alone. Most of the injuries (n = 23) were caused by road traffic accidents. 30 patients had injured the small bowel mesentery and 4 the large bowel mesentery. 25 of the 31 patients had associated injuries. There were no complications in the early group, compared with 6 wound infections and 1 case of small bowel obstruction in the delayed group (p < 0.0001). Median hospital stay in the early group was 11 days (range 3-24) compared with 23 days (range 10-61) in the delayed group (p = 0.004). CONCLUSION: Because delay in diagnosis is significantly associated with morbidity and duration of hospital stay we recommend that all patients admitted with blunt abdominal trauma should have a diagnostic peritoneal lavage as soon as possible

Adenoviral vector-mediated transfer of human heme oxygenase in rats decreases renal heme-dependent arachidonic acid epoxygenase activity.

Intravenous administration of an adenovirus human heme oxygenase (HO)-1 gene construct to rats resulted in functional expression of human HO-1 in brain, heart, lung, liver, and kidney. Because accurate assessment of human HO-1 mRNA in various tissues by Northern analysis is not sufficiently sensitive, we developed a method for quantifying human HO-1 mRNA copies with quantitative reverse transcription- polymerase chain reaction techniques; this allowed us to use the same primers for both the sample and internal standard. Administration of the adenovirus human HO-1 gene resulted in the detection of human HO-1 mRNA in various tissues with the highest levels seen in the kidney followed, in order, by lung > liver > brain > heart. Human HO-1 was detectable for up to 4 weeks in all tissues studied. Administration of adenovirus human HO-1 resulted in maximal increase of HO activity after 1 to 2 weeks in rats. The increase in HO activity due to gene transfer also was associated with a parallel decrease (approximately 25%) in cytochrome P-450 (CYP) content and in CYP-dependent arachidonic acid metabolism. In addition, we investigated the possibility that the human HO-1 gene altered the expression of the endogenous rat enzyme after administration of cobalt chloride s.c. Cobalt chloride administration resulted in increased HO activity in all tissues examined in rats transduced with the human HO-1 gene to the same degree as in nontransduced rats. The metal was a more potent inducer of renal HO activity than was the adenoviral-mediated human HO-1 vector. The increase in HO activity after adenoviral-mediated human HO-1 transfer was associated with a decrease in microsomal heme-CYP and CYP activity. The increase in HO-1 activity after adenovirus-mediated human HO-1 gene transfer may prove useful as a means of selectively increasing enzyme activity in a specific organ and regulating homeostasis by modulation of vasoactive molecules such as carbon monoxide and bilirubin and, in addition, providing a means of delivering the human HO-1 gene for experimental purposes.

Influence of growth factors erythropoietin and granulocyte macrophage colony stimulating factor on mechanical strength and healing of colonic anastomoses in rats.

OBJECTIVE: To find out what influence erythropoietin and granulocyte macrophage colony stimulating factor (GM-CSF) had on the healing of left colonic anastomoses in rats. DESIGN: Experimental study. SETTING: University hospital of Ioannina, Greece. ANIMALS: 40 rats. INTERVENTIONS: An end to end anastomosis was created in the left colon. The rats in the experimental groups were treated with erythropoietin, or GM-CSF, or the two in combination. MAIN OUTCOME MEASURES: Tensile breaking strength of the anastomosis, histological characteristics of the anastomosed segment, changes in body weight, and packed cell volume (PCV) during the experiment. RESULTS: The tensile breaking strength of the anastomosis on the seventh postoperative day was significantly greater in the erythropoietin group (mean 2.8N, 95% confidence interval (CI) 0.12N, p 0.0004) than in the control group (mean 1.60N, 95% CI 0.12N). It did not differ from the GM-CSF groups (mean 1.67N, 95% CI 0.21N, p 0.68) or erythropoietin GM-CSF (mean 1.67N, 95% CI 0.11N, p 0.44). The PCV was significantly higher in the two groups given erythropoietin (p < 0.001) but not in the GM-CSF group (p 0.8) while that in the control group was significantly lower (p < 0.001). The body weight followed the same pattern, being significantly more in the two groups given erythropoietin (p = 0.03 and 0.003) but not in controls (p = 0.09) or the GM-CSF group (p = 0.2). CONCLUSIONS: Erythropoietin enhances the healing of anastomosis in rat colon by increasing the number of fibroblasts and accelerating the maturation of new vessels.

Negative regulation of human heme oxygenase in microvessel endothelial cells by dexamethasone.

Heme oxygenase-1 (HO-1) is a stress protein, and its induction has been suggested to participate in defense mechanisms against agents that promote oxidative injury such as endotoxins and heme. We have shown that the inflammatory cytokines, interleukin-6 (IL-6) and heme-induced HO-1 gene expression, were suppressed by dexamethasone (Dex) in a sustained manner. We examined the mechanism by which the anti-inflammatory agent, Dex, inhibits IL-6 and heme-induced HO-1 expression in rabbit coronary endothelial cells. Endothelial cells treated with heme (10 microM) and IL-6 (25 ng/ml), increased HO-1 mRNA 15- and 60-fold, respectively. The activity of HO was increased 3-fold after such treatment. Although Dex failed to inhibit heme-mediated HO-1 mRNA and HO activity, it was able to reverse IL-6-stimulated HO activity. Several human HO-1 promoter-drive chloramphenicol acetyltransferase (CAT) constructs were examined to analyze IL-6 and Dex-mediated modulation of the HO-1 gene in endothelial cells. CAT assays revealed that the HO-1 promoter region between -180 and -1500 might contain a Dex-mediated negative regulator. Gel mobility shift assays using nuclear extracts from IL-6-treated endothelial cells showed a binding to the synthetic 21 base pairs of the HO-1 sequence that contains the putative STAT3 sequence. STAT3-specific probe inhibited nuclear binding protein to the putative HO-1-STAT3 sequence. This suggests that IL-6 induction of human HO-1 is mediated via the JAK-STAT pathway and that Dex inhibition of gene expression is carried out by activation of a transcriptional protein in competition with the STAT3 binding site.

Differential effects of heme oxygenase isoforms on heme mediation of endothelial intracellular adhesion molecule 1 expression.

Heme oxygenase (HO), by catabolizing heme to bile pigments, down-regulates cellular hemoprotein, hemoglobin, and heme; the latter generates pro-oxidant products, including free radicals. Two HO isozymes, the products of distinct genes, have been described; HO-1 is the inducible isoform, whereas HO-2 is suggested to be constitutively expressed. We studied the inducing effect of several metal compounds (CoCl(2), stannic mesoporphyrin, and heme) on HO activity. Additionally, we studied HO-1 expression in experimental models of adhesion molecule expression produced by heme in endothelial cells, and the relationship of HO-1 expression to the induced adhesion molecules. Flow cytometry analysis showed that heme induces intracellular adhesion molecule 1 (ICAM-1) expression in a concentration (10-100 microM)- and time (1-24 h)-dependent fashion in human umbilical vein endothelial cells. Pretreatment with stannic mesoporphyrin, an inhibitor of HO activity, caused a 2-fold increase in heme-induced ICAM-1 expression. In contrast, HO induction by CoCl(2) decreased heme-induced ICAM-1 expression by 33%. To examine the contribution of HO-1 and HO-2 to endothelial HO activity, specific antisense oligonucleotides (ODNs) of each isoform were tested for their specificity to inhibit HO activity in cells exposed to heme. Endothelial cells exposed to heme elicited increased HO activity, which was prevented (70%) by HO-1 antisense ODNs. HO-2 antisense ODN inhibited heme-induced HO activity by 21%. Addition of HO-1 antisense ODNs prevented heme degradation and resulted in elevation of microsomal heme. Western blot analysis showed that HO-1 antisense ODNs selectively inhibited HO-1 protein and failed to inhibit HO-2 protein. Incubation of endothelial cells with HO-1 antisense enhanced heme-dependent increase of ICAM-1. In contrast, addition of HO-2 antisense to endothelial cells failed to increase adhesion molecules. The role of glutathione, an important antioxidant, was examined on heme-induced ICAM-1 expression. Endothelial cells pretreated with a glutathione precursor, N-acetylcysteine, or glutathione ester, showed a decrease in heme-induced ICAM-1 expression of 37 and 44%, respectively, suggesting that the mechanism of ICAM-1 induction by heme may be partly dependent on the levels of antioxidant. It is possible that amelioration of the heme-induced oxidative stress and expression of ICAM-I is due, in part, to the induction of HO-1 activity. Regulation of HO activity in this manner may have clinical applications.

Immunohistochemical evaluation of cathepsin D expression in colorectal tumours: a correlation with extracellular matrix components, p53, pRb, bcl-2, c-erbB-2, EGFR and proliferation indices.

The immunohistochemical Cathepsin D (CD) expression of tumour and stromal cells was investigated in a series of 93 human colorectal adenocarcinomas and 22 adenomas with the intention to evaluate its prognostic significance and its contribution in the metastatic potential of colorectal cancer. CD expression was correlated with the expression of extracellular matrix components (collagen type IV, laminin and fibronectin), p53 protein, pRb, bcl-2, c-erbB-2, EGFR, proliferation indices (Ki-67, PCNA) as well as with other conventional clinicopathological features. CD expression (> 10% of positive tumour cells) was observed in 60.2% of carcinomas and in 72.7% of adenomas. Stromal CD expression was detected in all cases. A statistically significant positive correlation between neoplastic cells CD and stromal cells CD (SCCD) was observed in both carcinomas and adenomas. Cancer cells CD (CCCD) was positively correlated with collagen type IV and pRb expression as well as with PCNA score. In carcinomas, SCCD expression was statistically correlated with p53 protein and pRb expression and a trend for correlation with PCNA score was found. These data suggest that Cathepsin D of cancer and stromal cells, especially in combination with other markers, may provide more information about the biological behaviour of colorectal cancer.

Postoperative radiation and concomitant bolus fluorouracil with or without additional chemotherapy with fluorouracil and high-dose leucovorin in patients with high-risk rectal cancer: a randomized phase III study conducted by the Hellenic Cooperative Oncology Group.

BACKGROUND: Randomized studies have shown that postoperative chemotherapy with or without radiation therapy (RT) improved local control and survival of patients with stages II or III rectal cancer. However, the optimal sequence of treatments and the optimal chemotherapeutic regimen have not been defined. Modulation of fluorouracil (FU) by leucovorin (LV) has yielded a highly significant difference in response rate from that of FU monotherapy, as suggested by an overview of randomized trials in patients with advanced colorectal cancer. However, this difference in response rate did not translate into a survival benefit. PURPOSE: To evaluate the impact on the disease-free survival (DFS) and overall survival (OS) of patients with stages II or III rectal cancer of postoperative RT and concomitant bolus FU administration alone or with additional chemotherapy using FU and high-dose LV. PATIENTS AND METHODS: From October 1989 until February 1997, 220 patients were randomized postoperatively to receive either one cycle of chemotherapy with FU (600 mg/m2/week x 6 followed by a two-week rest) and leucovorin (LV, 500 mg/m2/week x 6 as a two-hour infusion) followed by pelvic RT with concomitant FU (400 mg/m2) as a rapid intravenous injection during the first three and last three days of RT, and three more cycles of the same chemotherapy with FU and LV (standard, group A, 111 patients) or pelvic RT with concomitant FU only (experimental, group B, 109 patients). RESULTS: As of August 1998, after a median follow-up of 4.9 years, there was no significant difference in either three-year DFS (Group A, 70.3%; group B, 68.2%, P = 0.53) or OS (group A, 77%; group B, 73.3%. P = 0.75). Cox multivariate analysis revealed stage of disease, number of infiltrated nodes, tumor grade, presence of regional implants and perforation to be significant prognostic factors. The incidence of severe side effects was significantly higher in the patients in group A than in those in group B (32.4% vs. 4.6%, P < 0.0001). CONCLUSIONS: The incorporation of additional chemotherapy with FU and LV into postoperative concomitant RT and bolus infusion of FU does not offer a > or = 10% three-year survival benefit over that of concomitant RT and bolus infusion of FU, and significantly increases toxicity in patients with stages II or III rectal cancer.

Pharmacologic effects of the red blood cell substitutes cross-linked and non-cross-linked hemoglobins on hematopoiesis in rabbits.

The red blood cell substitutes beta-beta cross-linked (DECA-Hb, XLBV-Hb) and non-cross-linked (HbA) hemoglobins (Hbs), were transfused into rabbits and their effects on hematopoiesis examined. All rabbits receiving DECA-Hb or XLBV-Hb tolerated the Hbs well, whereas 50% of the animals transfused with similar doses of non-cross-linked HbA died. Analysis of peripheral blood and bone marrow BFU-E and CFU-GM production revealed that there was no significant variation in the generation of BFU-E and CFU-GM numbers for each cross-linked Hb transfusion group, but there were significant reductions in the HbA group. In animals transfused with cross-linked Hbs, splenic heme oxygenase (HO) activity was similar to that of controls; liver HO activity was slightly elevated, whereas HO activity was significantly increased in kidneys. Transfusion with non-cross-linked HbA produced greater inductions of HO activity in the liver and kidneys. Hepatic delta-aminolevulinic acid synthase (ALAS) activity was significantly reduced in HbA-transfused animals, whereas transfusion with cross-linked Hbs produced only minor, statistically nonsignificant, reductions in ALAS activity.

Alterations in body weight, breaking strength, and wound healing in Wistar rats treated pre- and postoperatively with erythropoietin or granulocyte macrophage-colony stimulating factor: evidence of a previously unknown anabolic effect of erythropoietin?

Several growth factors, such as growth hormone and insulin-like growth factor-1, have been used to reverse the high rate of catabolism observed either after an operation or during serious illness. We conducted a pilot study in Wistar rats in an attempt to assess whether regulatory peptides widely used in clinical practice, such as erythropoietin (EPO) and granulocyte macrophage colony-stimulating factor (GM-CSF), alone or in combination, might influence the metabolism after surgery. Forty animals were randomly allocated into four groups (one control group and three experimental groups; 10 animals per group). The rats in the control group received isotonic NaCl; the rats in one experimental group received recombinant human EPO (rHuEPO) at a dose of 500 IU/kg (EPO group) and those in another received recombinant GM-CSF at a dose of 20 microg/kg (GM-CSF group); in the fourth group, each animal received the two drugs in combination (EPO/GM-CSF group). In all groups, rats were given the drug(s) or NaCl daily for 15 days before the operation and for 7 days after the operation until they were killed. We estimated the body weight (g) and the hematocrit (%) on the first day of the experiment (baseline values) and on the seventh day after the operation, and we estimated the rate of healing and the breaking strength of the intestinal anastomosis on the day the rats were killed. At the end of the study we found that the body weight (median 250 g, minimum 230 g, maximum 270 g) and the levels of hematocrit (median 64%, minimum 60%, maximum 65%) were significantly increased in the EPO group (P < .001 and P < .005, respectively) as compared with the baseline values (median 217.5 g, minimum 200 g, maximum 250 g; median 51.5%, minimum 45%, maximum 55%, respectively). A similar significant increase in body weight (median 230 g; minimum 200 g; maximum 250 g) and hematocrit (median 64%; minimum 59%; maximum 67%) was found at the end of the study in the EPO/GM-CSF group (P = .01 and P < .005, respectively) as compared with the baseline values (median 210 g; minimum 200 g; maximum 250 g; median 50%, minimum 48%, maximum 54%, respectively). The breaking strength (in newtons (N)) statistically differed in the four groups (Kruskal-Wallis, P = .0008). A comparison between groups showed that the breaking strength had been significantly increased in the animals in the EPO group (median 2.18 N, minimum 1.98 N, maximum 2.44 N) as compared with those in the control group (median 1.66 N, minimum 1.33 N, maximum 1.87 N; P = .004), GM-CSF group (median 1.73 N, minimum 1.25 N, maximum 2.07 N; P < .005), and EPO/GM-CSF group (median 1.71 N, minimum 1.37 N, maximum 1.91 N; P = .0005). In conclusion, this study demonstrated that the administration of rHuEPO appears to have a beneficial positive effect on the body weight, hematocrit, and healing rate and the breaking strength of large bowel anastomoses in rats. These observations provide evidence of an as-yet-unknown anabolic effect of EPO, and they may expand its usual applications. However, more studies are needed to confirm our findings and furthermore to define the optimal dose and timing of EPO administration.