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Biomedical subjects

A F Li

Publications and source records attributed to A F Li.

At least 37 records · Page 2Linked to original sources
PubMed1997

Prognostic indicators for survival after curative resection for patients with carcinoma of the stomach.

This study aims to determine prognostic indicators among patient-, tumor-, and treatment-related factors of gastric cancer patients. A total of 510 patients who underwent curative gastric resection were studied. Univariate analysis of patient-related factors showed a significantly lower survival in patients with a history of obstruction, hypoalbuminemia, and anemia. Tumor-related factors including gross appearance, location, and size of tumor; depth of cancer invasion; level, number, and frequency of lymph node metastasis; stromal reaction and tumor growth pattern; and histological classification all significantly affected survival. Surgical treatment related factors such as total or distal subtotal gastrectomy, extent of lymphadenectomy, and combined resection of adjacent organ(s) showed a statistically significant adverse influence on survival. Multivariate analysis identified only four tumor-related factors-number of metastatic lymph nodes, depth of cancer invasion, stromal reaction, and gross appearance of the tumor-as independently affecting survival. These findings suggest that only four tumor-related factors were prognostic indicators in patients with gastric cancer.

Adenocarcinoma↗
PubMed1997

Prolonged survival in a nasopharyngeal carcinoma patient with multiple metastases: a case report and review of the literature.

Nasopharyngeal carcinoma is a common cancer in South East Asia. In the early stages, radiotherapy alone may achieve sustained control, but once metastasis occurs, it becomes an incurable disease with limited survival time. We report a case of nasopharyngeal carcinoma, initial stage T4N0M0, diagnosed in 1985 in a patient aged 36 years who received 70 Gy radiotherapy to the head and neck region. In 1988, relapse occurred with multiple lung metastases. The patient received many chemotherapy regimens with a very good response, including near complete remission with the first treatment regimen of cisplatin, 5-fluorouracil and leucovorin for lung metastases, and with the fifth chemotherapy regimen of ifosfamide as a single agent. After ifosfamide treatment, there was residual fibrotic change in the lung and complete disappearance, lasting for almost a year, of the liver and bone lesions. The patient eventually died in July 1995 due to progressive disease. Prolonged survival after mainly thoracic metastasis is possible in patients with nasopharyngeal carcinoma, especially if the tumor is chemo-responsive.

Adult↗
PubMed1997

Effect of intermittent cigarette smoke inhalation on tibial lengthening: experimental study on rabbits.

We investigated the effect of intermittent cigarette smoke inhalation on the bone healing of tibial lengthening in rabbits. Thirty-eight male rabbits were divided into two groups of 19 animals each. The first group went through intermittent cigarette smoke inhalation, and the second group did not go through intermittent cigarette smoke inhalation. Each animal's right tibia was lengthened 5 mm using an uniplanar lengthening device. Five animals of each group were killed at 4, 6, and 8 weeks postoperatively for biomechanical testing, and one animal of each group was killed at 2, 4, 6, and 8 weeks postoperatively for histologic study. Using the contralateral nonoperated tibia as an internal control, we found that torsional strength of the lengthened tibia of the smoke inhalation group was decreased significantly compared with the non-smoke inhalation group. The mean percent of maximal torque at 4, 6, and 8 weeks were 22.0, 66.3, and 78.6%, respectively, in the smoke inhalation group, whereas the mean percent of maximal torque were 48.0, 84.1, and 90.8% %, respectively, in non-smoke inhalation group (one-tailed t test, p < 0.01, p < 0.01, and p < 0.05 at 4, 6, and 8 weeks, respectively). Our histologic observations revealed that the granulation tissue resorption, bone formation, and remodeling were delayed in smoke inhalation group. The results of this study suggest that intermittent inhalation of cigarette smoke delays, but does not prevent, the bone healing in tibial lengthening.

Animals↗
PubMed1997

Intestinal-type tumour in resected gastric remnant cancer.

Lauren's intestinal type of gastric cancer was proposed to be dependent on long-term environmental factors and is always preceded by chronic premalignant change. A cohort study was performed and demonstrated an increased cancer risk of gastric remnant after gastric surgery for benign disease. It is generally believed that after gastrectomy the residual stomach has an environmental change and, thus, enters a neoplastic process. Based on the carcinogenic theory of intestinal-type tumour, it would be of interest to know whether the intestinal-type tumour is more common in gastric remnant cancer. Forty patients with gastric remnant cancer had gastrectomy in the Veterans General Hospital-Taipei. Another 683 patients with primary gastric carcinoma underwent resection and were used as controls. The clinical characteristics, tumour stage and intestinal-type tumour were analysed in gastric remnant cancer and were compared with the various portions of primary gastric carcinoma. Although the overall distribution of intestinal-type carcinoma in gastric remnant (45%) was no different to that of any other portion of stomach cancer, intestinal-type carcinoma was more common in the early stage of gastric remnant (73%) and distal stomach (73%), but not in the proximal stomach (50%), which was supposed to have the same characteristics as the gastric remnant because of identical anatomic location. More than expected, intestinal-type carcinoma in early gastric remnant cancer together with a long incubation interval between primary surgery and later tumour occurrence were compatible with the theory of carcinogenesis of intestinal-type carcinoma.

Adenocarcinoma↗
PubMed1996

Adaptations of ligamentum teres in ischemic necrosis of human femoral head.

Little is known about the biomechanical properties of human ligamentum teres. To more fully understand the ligamentum teres, its dimensions and mechanical properties were measured in 22 cases of acute fracture of the femoral neck and 21 cases of ischemic necrosis of the femoral head. The specimens first were preconditioned and then loaded to failure with a testing machine at a fast strain rate of 100% s(-1). The ischemic necrosis group had a significantly larger volume (3.09 +/- 1.81 ml versus 1.30 +/- 0.62 ml) and cross section area (65.3 +/- 59.1 mm2 versus 30.6 +/- 27.2 mm2) than did the acute fracture group. The former also had a significantly greater ultimate load (234 +/- 168 N versus 130 +/- 111 N) and strain energy to failure (1.22 +/- 1.04 J versus 0.41 +/- 0.39 J), but a significantly smaller linear modulus (4.72 +/- 3.31 MPa versus 8.69 +/- 7.97 MPa) than did the latter. Histologic studies showed differences in the amount of organized collagen and components of subsynovial tissue between the 2 groups. Mechanical and morphologic adaptations of the ligamentum teres in a group of ischemic femoral heads are described, and a possible biomechanical role is suggested for the ligamentum teres in the hip joint in conjunction with the ischemic necrosis of the femoral head.

Adaptation, Physiological↗
PubMed1995

Defective mitochondrial oxidative phosphorylation in varicocele-bearing testicles.

OBJECTIVES: Our previous study revealed a decreased blood flow in varicocele-bearing testicles. For further understanding of the possible mechanism of varicocele-induced infertility, we investigated the changes in energy metabolism in varicocele-bearing testicles. METHODS: Partial ligation of the left renal vein was performed in 40 Wistar rats to induce dilation of the internal spermatic vein, and sham operations were performed in 20 other age-matched Wistar rats serving as controls. Orchiectomy was done at 1, 2, 4, and 6 months after induction of varicocele (or sham operation) in both groups. The histologic changes in the testicles were evaluated under the light microscope. The concentration of adenine nucleotides was determined by high-performance liquid chromatography, and various enzyme activities of mitochondria were determined by a spectrophotometer. RESULTS: Histologic studies of varicocele-bearing testicles showed a lower Johnsen score (8.5 +/- 0.7 versus 9.3 +/- 0.5) and a decreased mean testicular tubular diameter (280.0 +/- 3.2 versus 295.0 +/- 1.4 microns) compared with the testicles in the sham-operated group. The energy charge decreased from 0.71 +/- 0.04, 0.70 +/- 0.03, 0.69 +/- 0.06, and 0.64 +/- 0.03 to 0.62 +/- 0.08, 0.59 +/- 0.05, 0.58 +/- 0.05, and 0.56 +/- 0.02 at 1, 2, 4, and 6 months, respectively. The reduced nicotinamide-adenine dinucleotide-cytochrome c reductase activities were decreased from 136.6 +/- 4.9, 127.3 +/- 10.7, 121.6 +/- 7.8, and 118.9 +/- 8.5 to 96.3 +/- 13.9, 95.6 +/- 27.8, 88.3 +/- 13.8, and 80.4 +/- 8.7 nmol/min/mg of protein, respectively; the succinate-cytochrome c reductase activities were decreased from 50.4 +/- 2.7, 49.0 +/- 4.7, 49.6 +/- 7.1, and 42.6 +/- 1.6 to 40.3 +/- 7.3, 41.0 +/- 11.5, 40.2 +/- 5.7, and 32.0 +/- 1.3 nmol/min/mg of protein, respectively; and the cytochrome c oxidase activities were decreased from 361.2 +/- 23.4, 350.3 +/- 25.5, 223.5 +/- 12.9, and 194.1 +/- 18.3 to 253.7 +/- 32.9, 256.4 +/- 38.8, 178.2 +/- 15.7, and 147.1 +/- 17.2 nmol/min/mg of protein at 1, 2, 4, and 6 months, respectively. CONCLUSIONS: We thus suggest that defective energy metabolism plays an important role in the impairment of spermatogenesis of varicocele-bearing testicles.

Animals↗
PubMed1994

Morphological change in the urothelium after electrohydraulic versus pulsed dye laser lithotripsy.

OBJECTIVE: To observe morphological changes in the urothelium after exposure to laser beam and electrohydraulic spark. MATERIALS AND METHODS: The pulse dye laser lithotripter (MDL-2, Candela Corporation, Boston, USA) and the electrohydraulic lithotripter (AEH-2, Circon ACMI Corporation Stamford, USA) were used directly on the bladder mucosa in six pigs. Immediately after treatment, the bladder mucosa was prepared for light microscopic and scanning electron microscopic examination. RESULTS: Both electrohydraulic spark and laser beam caused mucosal denudation, submucosal swelling and haemorrhage. There was a positive correlation between the degree of urothelial damage and the power and pulse numbers applied. CONCLUSION: Direct contact of the urothelium in patients treated with laser beam or electrohydraulic spark should be avoided.

Animals↗
PubMed1993

DNA ploidy as a major prognostic factor in resectable ampulla of Vater cancers.

The archival paraffin-embedded specimens from 63 ampulla of Vater cancers after pancreaticoduodenectomy between 1965 and 1991 were analyzed by flow cytometry. Of the 63 cancers, 31 (49.2%) were diploid DNA cancers and 32 (50.8%) were aneuploid. Patients with diploid DNA cancer had a median survival time of 159.0 months, and patients with aneuploid DNA cancer had 24.0 months. This difference is statistically significant (P = 0.0257). The aneuploid group did have a poorer prognosis than the diploid group. The multivariate analysis demonstrated that DNA ploidy was an independent and very important prognostic factor, even stronger than the stage and lymph node status. There was a tendency toward higher values of S-phase fraction, proliferative index, and total aneuploid DNA fraction in the shorter survival groups, but they were of no statistical significance. These data suggest that DNA ploidy appears to be the most important and the only pre-operative predictor of prognosis in resectable ampulla of Vater cancers since endoscopic biopsy is feasible.

Ampulla of Vater↗
PubMed1991

Differential response of rat limb bones to strenuous exercise.

We examined the influence of a strenuous exercise regimen on tibial and metatarsal bones to show not only how the geometric, histological, and mechanical properties of immature bone respond to strenuous exercise but also how long bones within the same limb may respond differentially to exercise. Female Sprague-Dawley rats (8 wk old) were divided randomly into two groups: a sedentary control (n = 15) and an exercised group (n = 15). The exercise intensity was 80-90% of maximum oxygen capacity 5 days/wk for 10 wk. Mechanical properties of tibia and second metatarsus (MT) were determined with three-point bending, and contralateral bones were used for geometric and histological analyses. Length and middiaphyseal cross-sectional geometry of the exercised tibiae were significantly less than controls, but material properties were not different. The exercised tibiae had significantly lower structural properties (e.g., loads at the proportional limit and maximum and energy at failure load). The middiaphyseal dorsal cortex of exercised MT was significantly thicker than controls, but tensile stress at the proportional limit and elastic modulus of exercised MT were significantly less than controls. The average number of osteons and osteocytes per unit area of the tibial middiaphysis was significantly greater in the exercised group--especially in lateral and posterior cortices. The number of osteons and osteocytes per unit area in the MT, however, was significantly less in the exercised group. The differential effects of strenuous exercise on tibia and MT suggest that local loading and bone-specific responses have important roles in modulating the response of immature bone to strenuous exercise.

Adaptation, Physiological↗
PubMed1990

Effects of a high fat-sucrose diet on cortical bone morphology and biomechanics.

High fat-sucrose (HFS) diets can reportedly produce glucose intolerance and hyperinsulinemia that may indirectly have deleterious effects on bone. The effects of a high-fat diet on calcium absorption, bone calcium content, and bone mechanical properties, however, remain controversial. Thus, we examined the morphological and biomechanical adaptations in limb bones of rats that were fed a HFS diet. Female Sprague-Dawley rats (8 weeks old) were randomly assigned to two groups, either a control group (n = 9) fed a standard diet (low-fat complex-carbohydrate) or an experimental group (n = 9) fed a HFS diet for 10 weeks. The right tibia and second metatarsus (MT) were fractured in three-point bending, and contralateral bones were used for morphological and histological analyses. HFS tibias had significantly lower maximum load and failure energy, and tensile stress at the proportional limit for both HFS tibia and MT was significantly less than controls. In addition, the elastic modulus and density of the HFS MT was significantly lower than controls. Geometry of the tibial mid-diaphysial cross section did not differ for the two diets, but the cortical cross-sectional area of HFS MT increased significantly compared to control MT. The total number of osteons in the mid-diaphysis of HFS MT decreased, but tibial and MT porosities did not change with the HFS diet. Our results suggest that the deleterious effects of the HFS diet may be more related to changes in the material properties of the cortical bone rather than to osteoporotic changes in the bone.

Animals↗
PubMedDate not supplied

Soil quality evolution after land use change from paddy soil to vegetable land.

A survey was done in 15 typical villages, 150 soil and 86 vegetable plant samples were taken in Jiaxin prefecture of the Taihu Lake region, northern Zhejian province. Results indicate that after 15-20 years land use changed from the paddy rice-wheat (or oilseed rape) double cropping system, to a continuous vegetable land has caused soil quality dramatic change. (1) Acidification: average soil pH was 5.4; about 61% of total samples were pH < 5.5. It was 0.9 units lower than 10 years ago with same upland vegetable cultivation and was 1.2 units lower than soil pH of paddy rice-wheat (or oilseed rape) rotation. (2) Fertilizer salt accumulation: the average salt content was 0.28%, among these about 36.2% of the total samples contained more than 0.3%. (3) Nitrate N and available phosphorus (P) over accumulation: on average it was 279 mg NO3-N/kg, and 45-115 mg P/kg. Nitrate N four times higher and available P 4-10 times more than it is in present paddy rice-wheat rotation soils respectively. This has caused wide concern because of possible groundwater and well drinking water pollution by leached nitrate N and the P losses to water by runoff from vegetable lands induce surface water eutrophication.

Agriculture↗
PubMedDate not supplied

Ambient level ozone effects on subpopulations of thymocytes and spleen T lymphocytes.

The effects of ozone on thymocyte and spleen T lymphocyte subpopulations were studied. Balb/c mice were exposed to clean air or to 0.3 +/- 0.05 ppm ozone for 1-3 wk. Thymocytes and spleen T cells were stained with fluorochrome conjugated monoclonal antibodies against surface differentiation markers and/or propidium iodide for deoxyribonucleic acid (DNA). The cells were then analyzed by fluorescence activated cell sorter. The percentages of certain thymocyte and spleen T lymphocyte subtypes and DNA synthesizing spleen T cells were lower following 1 wk of ozone exposure. After 3 wk exposure, the thymocyte percentages were higher in ozone-exposed mice, whereas the absolute number remained lower, and spleen T lymphocytes showed no changes. The findings suggest that short-term ozone inhalation can affect the T cell immune system adversely, particularly the CD4+ cells.

Animals↗
PubMedDate not supplied

Hepatocyte growth factor and Met/HGF receptors in patients with gastric adenocarcinoma.

Overexpression and amplification of Met/HGF receptor has been detected in gastric cancer tissues and cell lines. In this study hepatocyte growth factor (HGF) and Met/HGF receptors were localized in 32 gastric cancer and adjacent normal gastric tissues by the avidin-biotin-peroxidase complex technique. HGF (87.5%) and Met/HGF receptors (68.8%) were demonstrated in gastric cancer tissues. A high positive rate of HGF (87.0%) and Met/ HGF receptors (82.6%) presented in intestinal type gastric cancer. HGF immunoreactivity in gastric cancer tissues was a significant and powerful prognostic indicator (relative risk 15.9; p=0.01). These data suggest that HGF and Met/HGF receptors are involved in the morphogenesis of intestinal type gastric cancer. HGF may have other mechanism that favor gastric cancer spread and independently affect survival.

Adenocarcinoma↗
PubMedDate not supplied

Oxidative stress is insignificant in N1S1-transplanted hepatoma despite markedly declined activities of the antioxidant enzymes.

It has been proposed that persistent oxidative stress accounts for the increased levels of DNA damage in cancer tissues. We have examined the profile of anti-oxidant enzymes in a transplanted hepatic tumor model by injecting N1S1 rat hepatoma cells into the liver of Sprague-Dawley rats. The transplanted N1S1 tumors displayed characteristics resembling human hepatocellular carcinoma. The immunoreactivities of catalase (CAT), manganese-superoxide dismutase (Mn SOD), copper/zinc-SOD (Cu/Zn SOD), and glutathione peroxidase (GPx) were found to decrease significantly. The enzyme activity in tumors decreased 26.2-, 4.2-, 4.5-, and 5.4-fold for CAT, Mn SOD, Cu/Zn SOD, and GPx, respectively, relative to those in normal liver tissue from the same animals. In contrast, the mRNA levels of CAT and GPx in tumors decreased only 5- and 2-fold, respectively, and the mRNA levels of Cu/Zn SOD and Mn SOD showed either no change or an increase as compared to those of normal liver tissue. The contents of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) and thiobarbituric acid-reactive substances (TBARS) were comparable to those of normal controls. Furthermore, mitochondrial production of superoxide in tumors was 4 times lower than that in normal tissues. In conclusion, the data indicate that the reduced activities of anti-oxidant enzymes in the N1S1 tumor did not cause significant oxidative stress.

Animals↗
PubMedDate not supplied

The role of MIB-1 index in the prognosis of resectable pancreatic head cancer.

BACKGROUND/AIMS: Cell kinetics are important indicators of the biological behavior of various human tumors. In this study, we evaluated the prognostic values of the proliferative factors including MIB-1 index, DNA ploidy and S-phase fraction, and further determined the independent prognostic factors in pancreatic head cancer after pancreatoduodenectomy. METHODOLOGY: Patients with pancreatic head cancer undergoing pancreatoduodenectomy were included. Cell proliferative parameters including MIB-1 index, DNA ploidy and S-phase fraction measured by flow cytometry were evaluated and compared with the conventional clinicopathologic factors. RESULTS: There were 21 resectable pancreatic head cancers. By univariate analysis MIB-1 index, cell differentiation and lymphovascular invasion were significant prognostic factors. The 5-year survival rate was 22.2% for overall patients and 29.2% for patients with MIB-1 < or = 11%, while it was 0% for MIB-1 index > 11%, p=0.011. Tumors without lymphovascular invasion had significantly better prognosis than those with lymphovascular invasion (median survival: 38 vs. 10 months, p=0.009). The median survival was significantly longer for well-differentiated cancers than for moderately and poorly differentiated cancers (44 vs. 11 and 9 months, p=0.038). There was no correlation between the MIB-1 index and the other 2 conventional prognostic factors. After multivariate analysis, only the MIB-1 index emerged as the independent prognostic factor. CONCLUSIONS: MIB-1 index played a significant role in the prognosis of the resectable pancreatic head cancer and could potentially complement the conventional factors in predicting the prognosis and determining the optimal treatment strategy. MIB-1 index was also an important independent prognostic factor.

Adult↗