Structure and dynamics from solid state NMR spectroscopy.
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Computer Simulation↗
Biomedical subjects
F Tian
Publications and source records attributed to F Tian.
The disintegration of absorbable suture materials on exposure to human digestive juices: an update.
This is a comparative study of the disintegration of absorbable sutures when incubated in human gastric juice, bile, pancreatic juice, and their mixture. Plain catgut rapidly lost its strength in each of these digestive fluids. Chromic catgut was susceptible to digestion although it retained most of its strength in bile for two weeks. Synthetic absorbable sutures, polyglycolic acid or its derivatives (Dexon "S", Dexon Plus, and Maxon), maintained most of their strength for 2 weeks, disintegrating only after 5 to 8 weeks. Controls of saline or human plasma had little demonstrable effect. As a further control, silk maintained its strength under each exposure. Although catgut is widely used, the study suggests that it disintegrates too rapidly, at least under the conditions tested, to be appropriate for alimentary tract surgery, whereas the synthetic sutures maintained their integrity rather well for the 2 to 3 weeks needed for visceral wound healing. The data suggest that slowly absorbed synthetic sutures may be particularly useful in pancreatic or biliary anastomoses where a single layer is preferable and where a nonabsorbable suture offers inherent disadvantages.
Bile↗
Prognostic value of serum CA 19-9 levels in pancreatic adenocarcinoma.
Thirty-eight patients with histologically proven pancreatic adenocarcinoma were investigated to establish the utility of serum CA 19-9 as a prognostic indicator. CA 19-9 assays were performed serially during the course of the disease. In four patients with negative Lewis blood type, the CA 19-9 levels remained essentially normal throughout the disease course. In the remaining 34 patients, (1) CA 19-9 levels were significantly lower in patients with tumor size no larger than 5 cm in diameter, and in patients with resectable tumors than in those with tumor size larger than 5 cm or with unresectable tumors (p less than 0.01). 2) CA 19-9 levels dropped sharply after resection in all 11 resectable patients, whereas no significant change was found after laparotomy without resection. (3) The average survival time in seven patients whose CA 19-9 levels returned to normal after resection was significantly longer than in those four patients with postoperative CA 19-9 levels that decreased but did not return to normal (21.9 versus 8.7 months, p less than 0.05). (4) In 6 of 11 patients who underwent resection, recurrent elevation of CA 19-9 preceded changes detectable by computed tomography or clinical examination by 2 to 9 months. (5) In 23 patients who died of pancreatic carcinoma, 15 (65%) had an obvious rise in CA 19-9 level before death. There was a correlation between the doubling time of the CA 19-9 serum level and survival time (r = 0.5, p less than 0.05). Because it can be demonstrated that the reduction of tumor burden by resection lowers serum CA 19-9 levels, serum CA 19-9 levels may be a useful indicator of whether other forms of treatment such as radiation therapy or chemotherapy also reduce the tumor burden.
Adenocarcinoma↗
Detection of occult metastases in pancreatic adenocarcinoma with anticytokeratin antibody.
Fifty-six lymph nodes excised from 11 patients with pancreatic adenocarcinoma were studied for evidence of metastasis by standard light microscopy and immunohistochemistry using an anticytokeratin monoclonal antibody. Eight of 56 nodes contained metastatic carcinoma as demonstrated by conventional techniques. By immunohistochemistry, positive-staining cells were easily identified. In 10 of 56 nodes, the positive staining was accompanied by cytologic atypia, changes consistent with malignancy. In seven additional nodes, positive-staining cells were present, but cytologic atypia was lacking. The use of immunohistochemistry facilitated recognition of malignant cells and raised questions that single-cell metastasis may be present. Positive staining for cytokeratin should prompt a close examination of cells to determine if morphologic features of malignancy are present.
Adenocarcinoma↗
Occupational exposure to benzene in China.
Of a total of 528,729 workers exposed to benzene or benzene mixtures in China, 508,818 (96.23%) were examined. Altogether 2,676 cases of benzene poisoning were found, a prevalence of 0.15%. A higher prevalence of benzene poisoning was found in the cities of Hangjou, Hefei, Nanjing, Shenyang, and Xian. The geometric mean concentration of benzene in 50,255 workplaces was 18.1 mg/m3 but 64.6% of the workplaces had less than 40 mg/m3. There was a positive correlation between the prevalence of benzene poisoning and the concentration in shoemaking factories. The prevalence of benzene induced aplastic anaemia in shoemakers was about 5.8 times that occurring in the general population. The results of this investigation show the need for a practicable hygiene standard to prevent benzene poisoning.
Adult↗