Establishment and assessments of a new model for the postoperative fatigue syndrome by major small intestinal resection in rats.

OBJECTIVE: Postoperative fatigue syndrome (POFS) is a general and main complication after surgery. However, there is no stable and standardized animal model for POFS. The aim of the present study was to establish a rodent model of POFS by small intestinal resection, with POFS evaluated by acknowledged physical and behavioral methods. MATERIAL AND METHODS: Forty-two Sprague-Dawley rats were randomly divided into four groups according to the length of a "middle" small intestinal resection: 0% (sham group; i.e., laparotomy alone), 10%, 40% and 70% groups, with corresponding lengths of small intestinal resections. Following surgery, the general state of health was evaluated. Tail suspension test, open field test and Morris water maze test were used to evaluate the degree of POFS. Serum albumin, transferrin, prealbumin and fibronectin were measured to assess the nutritional status, and superoxide dismutase (SOD) and malondialdehyde (MDA) were also measured. RESULTS: As compared with the other three groups, the 70% small intestinal resection group showed the worst general state of health, decreased strength of the tail suspension test and decreased score of Morris water maze test (p < 0.05) after operation. All rats in whom the small intestinal resection was done demonstrated a certain degree of malnutrition and behavior of depression, and the 70% resection group had the lowest levels of transferrin, prealbumin and fibronectin as compared with the other groups (p < 0.05), as well as decreased SOD and increased MDA in serum (p < 0.05). CONCLUSIONS: Resection of 70% of the small intestine resulted in typical characteristics of POFS. As this procedure is simple, stable and easily reproducible, it may serve as a model for research on POFS.

Field of attention for instantaneous object recognition.

BACKGROUND: Instantaneous object discrimination and categorization are fundamental cognitive capacities performed with the guidance of visual attention. Visual attention enables selection of a salient object within a limited area of the visual field; we referred to as "field of attention" (FA). Though there is some evidence concerning the spatial extent of object recognition, the following questions still remain unknown: (a) how large is the FA for rapid object categorization, (b) how accuracy of attention is distributed over the FA, and (c) how fast complex objects can be categorized when presented against backgrounds formed by natural scenes. METHODOLOGY/PRINCIPAL FINDINGS: To answer these questions, we used a visual perceptual task in which subjects were asked to focus their attention on a point while being required to categorize briefly flashed (20 ms) photographs of natural scenes by indicating whether or not these contained an animal. By measuring the accuracy of categorization at different eccentricities from the fixation point, we were able to determine the spatial extent and the distribution of accuracy over the FA, as well as the speed of categorizing objects using stimulus onset asynchrony (SOA). Our results revealed that subjects are able to rapidly categorize complex natural images within about 0.1 s without eye movement, and showed that the FA for instantaneous image categorization covers a visual field extending 20° × 24°, and accuracy was highest (>90%) at the center of FA and declined with increasing eccentricity. CONCLUSIONS/SIGNIFICANCE: In conclusion, human beings are able to categorize complex natural images at a glance over a large extent of the visual field without eye movement.

Soy isoflavone delays the progression of thioacetamide-induced liver fibrosis in rats.

OBJECTIVE: Our aim was to investigate the effect of soy isoflavone (SI) on liver fibrosis in a thioacetamide (TAA)-induced rat model. MATERIALS AND METHODS: Twenty-eight rats were assigned to four groups: sham group, fibrosis group, low-dose treatment group (LDg) and high-dose treatment group (HDg). SI (90 or 270 mg/kg) was administered daily during the model development by TAA. Standard liver tests, platelet derived growth factor-BB (PDGF-BB) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were measured. The expression of collagen, α-smooth muscle actin (α-SMA) and transforming growth factor-ß1 (TGF-ß1) in liver tissue was determined. Electron microscopy was used to perform ultrastructural analysis of the livers. RESULTS: Hepatic fibrosis was induced by 8 weeks of TAA administration. However, following the administration of SI, collagen staining significantly declined as compared with the fibrosis group (p < 0.01). Less collagen fibers around the hepatic stellate cells (HSCs) were observed in HDg as compared to the fibrosis group and LDg. There was no significant difference in standard liver tests between the fibrosis group and the two treatment groups. The levels of PDGF-BB and TIMP-1 in the two SI-treated groups were significantly lower than in the fibrosis group (p < 0.01). The expression of α-SMA and TGF-ß1 in HDg was less than that in the fibrosis group and LDg (p < 0.01). CONCLUSION: Administration of a high dose of SI resulted in an obvious inhibitory effect on liver fibrosis induced by TAA in rats. One hypothesis is that the effect may be related to the inhibition of HSC activation and proliferation.

[Effect of adjuvant chemotherapy of ginsenoside Rg3 combined with mitomycin C and tegafur in advanced gastric cancer].

OBJECTIVE: To evaluate the enhancing effects of ginsenoside Rg3 combined with mitomycin C and tegafur (MF) on postoperative chemotherapy in advanced gastric cancer. METHODS: Seventy-one postoperative patients with advanced gastric cancer were randomly divided into two groups, the control group (n=33), which received treatment with only MF (Mitomycin C+Tegafur), and the trial group (n=38), which were treated with ginsenoside Rg3+MF. The serum VEGF levels in the control group and trial group were detected preoperatively and postoperatively, meanwhile, the serum VEGF levels in 30 healthy persons were detected as comparison. The relations between patients survival and serum VEGF levels were analyzed. RESULTS: The levels of serum VEGF in advanced gastric cancer were higher than those in healthy persons [(297.8+/-129.6) pg/ml vs (212.3+/-67.5) pg/ml] (P<0.01), and were correlated with the depth of tumor invasion, lymph node metastasis, tumor size > 4 cm and TNM stage (P<0.05). Fourteen weeks after operation, the levels of serum VEGF in trial group decreased below those of preoperation and approached to normal range, while in the control group, the levels of serum VEGF decreased near those of preoperation only. The median survival of patients in trial group and control group were 40 and 25 months respectively. The survival rate of patients in trial group was significantly higher than that in control group (P=0.047). CONCLUSION: The combined application of ginsenoside Rg3+MF chemotherapy can decrease the concentration of serum VEGF and improve the survival rate in advanced gastric cancer patients.

Diagnosis and surgical treatment of primary hepatic cholangiocarcinoma.

BACKGROUND/AIMS: To summarize the experience in the diagnosis and surgical treatment of primary hepatic cholangiocarcinoma (PHCC). METHODOLOGY: Forty-seven PHCC patients, who had undergone surgical treatment in our hospital from 1970 to 1999, were retrospectively analyzed with their clinicopathological features, surgical treatments and prognoses. RESULTS: 1) PHCC patients lacked typical clinical manifestation, and some had an accompanying history of virus B hepatitis (36.2%, 17/47) and liver cirrhosis (46.8%, 23/47), and elevation of AFP (25.5%, 12/47). 2) The detection rates of BUS, CT, MRI and liver scintigraphy were 95.7% (45/47), 93.6% (44/47), 100% (23/23) and 100% (4/4), respectively. The lesions detected by those methods needed to differentiate with hepatocellular carcinoma. 3) The resection rate was 76.6% (36/47), the postoperative overall 1-, 3- and 5-year survival rates were 54.1% (24/47), 34.0% (16/47), and 29.8% (14/47) in all patients, respectively, including the 1-, 3- and 5-year survival rates were 83.3% (30/36), 50.0% (18/36), and 38.9% (14/36) in hepatectomy cases, respectively. 4) All of the four patients who survived more than 5 years, including small liver cancer (< or = 3 cm) three cases and encapsulated large nodular lesion one case, received curable resection and postoperative adjuvant therapies. CONCLUSIONS: PHCC patients can obtain a better result by early detection and curative resection with adjuvant therapies.