Biomedical subjects

Wen Gao

Publications and source records attributed to Wen Gao.

36 records · Page 2Linked to original sources

PubMed2005

[Prognostic factors on outcome of radiofrequency ablation of 172 primary hepatic tumors].

OBJECTIVE: To investigate the prognostic factors affecting outcome in Radiofrequency (RF) ablation of primary hepatic tumors by univariate and multivariate analyses, and to assess the therapeutic efficacy of Radio-frequency ablation. METHODS: A total of 172 patients with primary hepatic tumors underwent RF treatment in our department between 1999 and 2004. Among them, 150 patients were not the surgery candidates. The follow-up period ranged from 4 to 51 months and follow-up rate was 94.8% (163 patients). Kaplan-Meier model and log-rank test were used in univariate analyses and COX regression model was used in multivariate analyses, to identify prognostic factors for survival. RESULTS: The survival rates at half a year, 1 year, 2 year and 3 year were 91.5%, 77.4%, 55.7% and 51.2% respectively. Using univariate analyses, 24 potential factors were analyzed and 8 of them were found significant for survival. These 8 factors were Child-Pugh grade, UICC stage, AFP value before first RF, Portal hypertension, first treatment or treatment for recurrence, pathological grade, treatment purpose and method, ablative safe margin. For 116 patients who underwent RF when first diagnosis, the survival rates in patients with different tumor stage (UICC standard of hepatocellular carcinoma) at half a year, 1 year, 2 year and 3 year were estimated as follows: 96.7%, 92.3%, 81.6% and 65.3% in 33 patients of stage I-II; 91.2%, 76.3%, 56.6% and 51.4% in 83 patients of stage III-IV; There was significant difference in survival rates between patients of stage I-II and patients of stage III-IV. For 56 patients suffered from recurrent hepatic tumors, the survival rates at half a year, 1 year, 2 year and 3 year were 88.5%, 70.2%, 41.4% and 24.5%, being similar to those of stage III-IV. The 8 factors mentioned above were further analyzed by multivariate model and 3 of them were identified as prognostic factors for survival. These 3 factors included Child-Pugh grade, Portal hypertension, treatment purpose and method. CONCLUSION: Based on our statistical analysis, the prognostic factors on outcome in Radio-frequency ablation of hepatic tumors were grouped into two categories. Child-Pugh grade, and Portal hypertension were the characteristics of patients and uncontrollable. While treatment purpose and method also had significant impact on survival and was controllable during RF procedure. This information might be useful to improve treatment level of Radio-frequency ablation of hepatic tumors.

Adult↗

PubMed2005

[Radiofrequency ablation of recurrent hepatocellular carcinoma after hepatectomy].

OBJECTIVE: To assess the efficiency and safety of radiofrequency ablation (RFA) of recurrent hepatocellular carcinoma (RHCC) after hepatectomy and to investigate efficacy of RFA for patients with early and late phase recurrence, separately, setting 1 year as the cut-off between the early and late phases. METHODS: A total of 42 patients with 77 RHCC and a history of hepatic resection for hepatocellular carcinoma (HCC) underwent ultrasound-guided percutaneous radiofrequency ablation in our department and entered this study (RHCC group). The average diameter of RHCC was (3.8 +/- 1.4) cm (range, 1.5-6.6 cm). 21 of the 42 RHCC patients had Child-Pugh class A cirrhosis 19, class B and two, class C cirrhosis. The average interval between initial surgery and the diagnosis of recurrence was 22.8 months (range, 1-96 month). 42 RHCC patients were divided into two groups as early recurrence group including 20 patients with 40 RHCC, and late recurrence group including the other 22 patients with 37 RHCC according to the recurrence interval. During the same period 148 patients with 217 primary HCC were also treated by RF ablation and regarded as primary HCC group. The average diameter of primary HCC was (4.0 +/- 1.4) cm (range, 1.2-7.0 cm). Regular follow-up with enhanced CT was performed to evaluate the treatment results. Ablation was considered a success if no contrast enhancement was detected in the treated area on 1 month CT scans. RESULTS: The ablation success rate, local recurrence rate, new tumor incidence and mean survival in RHCC group were 90.5%, 14.3%, 38.1% and (28.0 +/- 3.5) months, respectively, which were similar to the corresponding results of 87.2%, 16.2%, 37.8% and (39.0 +/- 2.1) month in primary HCC group. However, when further comparison was performed between early recurrence group, late recurrence group and primary HCC group, there were some significant differences. The incidence of new tumors in early recurrence group was significantly higher than that in late recurrent group (60.0% vs. 18.2%, P = 0.005); early recurrence group survived shorter than primary HCC group [(15.4 +/- 2.3) vs. (39.0 +/- 2.1) months, P < 0.005]. The survival time was similar between late recurrence group and primary HCC group. One case was found haemorrhage after RFA and recovered with conservative treatment. No major complications occurred in the remaining 41 patients. CONCLUSIONS: RF ablation is generally effective and safe in treating RHCC. And it's more effective in late recurrence than in early recurrence.

Adult↗

PubMed2005

[Standard treatment of liver malignancies with radiofrequency ablation].

OBJECTIVE: To investigate the role of standard treatment with ultrasound-guided radiofrequency ablation (RFA) in improving the treatment level of liver malignancies. METHODS: 302 patients with 476 liver malignancies were treated with established protocol and adjuvant measures and subjected to efficiency analysis. In the 302 patients, 181 had 282 hepatocellular carcinomas (HCC) with a mean diameter of 4.2 cm, and 121 had 194 metastatic liver carcinomas (MLC) with a mean diameter of 3.9 cm. According to UICC-TNM system 50 patients (27.6%) were in stage I/II and 131 (72.4%) in stage III/IV (including 39 patients with recurrent HCC after surgical resection). A standard protocol and an individualized protocol were used to treat the tumors based on their size, shape and special location such as the distance from diaphragm, gallbladder and gastrointestinal tract. Needle placement method and operation skill for the tumor region adjacent to important structures were described. Some adjuvant measures such as supplementary fine needle localization, local saline injection and feeding vessel ablation were used to improve RFA efficacy in tumors with different features. Local ablation of bleeding site and haemostatic administration systemically were adopted to deal with bleeding. For the patients with tumor adjacent to gastrointestinal tract, prolonged fasting after the RFA procedure was required. the patients were followed up regularly to assess the treatment efficiency, and the tumor was considered complete necrosed if no viability was found on enhanced CT or enhanced US one month after RFA. RESULTS: The tumor necrosis rate was 95.7% (270/282 tumors) for HCC, 94.8% (184/194 tumors) for MLC, 91.1% (51/56 tumors) for tumor near gastrointestinal tract, 88.5% (69/78 tumors) for tumors near diaphragm, and 94.3% (49/52 tumors) for tumor near gallbladder. The local recurrence rate was 10.3% (29/282 tumors) for HCC and 14.4% (28/194 tumors) for MLC. The 1, 2 and 3 year overall survival rates were 87.6%, 67.4% and 58.6% in the HCC patients, and 87.4%, 48.2%, 25.3% in the MLC patients respectively. The 1, 2 and 3 year survival rates of 50 HCC patients in early (I-II) stages were 90.7%, 85.9% and 73.7%, respectively. The incidence of complications was 2.2% (13/583 sessions), including 5 cases of hemorrhage, 1 case colon perforation, 8 cases of injury of adjacent structures. CONCLUSION: Application of proper protocol and adjuvant measures plays an important role in improving tumor ablation rate. Knowledge about possible complications and their control may increase the treatment efficacy and help to promote the use of RFA technique.

Carcinoma, Hepatocellular↗

PubMed2005

[Efficacy of radiofrequency ablation of 343 patients with hepatic tumor and the relevant complications].

OBJECTIVE: To investigate the treatment efficacy of radiofrequency ablation (RFA) of hepatic tumors and the relevant complications. METHODS: A total of 343 patients with 778 hepatic tumors underwent ultrasound-guided RFA (582 procedures). There were 212 cases of hepatic cellular carcinoma (HCC) with 448 tumors, and the average largest diameter was 4.0 cm. Of all the patients, 63 (29.7%) were in the stage of I-II (UICC Systems) and 149 (70.3%) in stage of III-IV (including 43 patients with tumor recurrence after surgical resection). There were 131 cases of metastatic liver carcinoma (MLC), with 330 metastases in the liver, the average diameter was 3.9 cm, and the liver metastases of 91 patients (69.5%) came from gastrointestinal tract. The patients were treated using the relatively standard protocol. Crucial attention must be paid to monitoring the abnormal changes in ultrasound images as well as the vital signs of the patients to find the possible hemorrhage and peripheral structure injury in time. The tumors were considered ablated successfully if no viability was found on enhanced CT within 24 hours or 1 month after RFA. The patients were followed up for 2-62 months. RESULTS: The ablation success rate for HCC was 95.5% (428/448 tumors), and the rate for MLC was 96.4% (318/330 tumors). The local tumor recurrence rates for HCC and MLC were 8.5% (38/448 tumors) and 11.8% (39/330 tumors), respectively. A total of 138 patients (40.2%) underwent repeated ablations for 2-11 times because of tumor recurrence or metastasis. The first, second and third years survival rates were 87.7%, 67.4% and 56.8% for HCC patients, 81.6%, 50.8% and 27.2% for MLC patients, respectively. The survival rate from 63 early-stage HCC patients were 92.9%, 82.8% and 74.5%, respectively. The major complication rate in this study was 2.4% (14 of 582 procedures). The complications which consisted of mechanical and thermal injuries usually occurred during or shortly after the RFA treatment. There were 5 hemorrhages, 1 colon perforation, 5 injuries of adjacent structures, 2 bile leakages and 1 skin burn. CONCLUSION: RFA, as a minimally invasive local treatment, has become an effective and relatively safety alternative for the patients of hepatic tumors, even of advanced live tumor, tumor recurrence, liver metastases which are unresectable or difficult to treat with traditional therapies. Knowledge about possible complications and their control may increase the treatment efficacy and help to promote the use of RFA technique.

Adult↗

PubMed2005

Chromic-P32 phosphate treatment of implanted pancreatic carcinoma: mechanism involved.

AIM: To study the effects of chromic-P32 phosphate (32P colloids) interstitial administration in Pc-3 implanted pancreatic carcinoma, and investigate its anticancer mechanism. METHODS: Ninety-eight tumor bearing nude mice were killed at different time points after the injection of 32P colloids to the tumor core with observed radioactivity. The light microscopy, transmission electron microscopy (TEM) and immuno-histochemistry and flow cytometry were used to study the rates of tumor cell necrosis, proliferating cell nuclear antigen index, the micro vessel density (MVD). The changes of the biological response to the lymphatic transported 32P colloids in the inguinal lymph node (ILN) were dynamically observed, and the percentage of tumor cell apoptosis, and Apo2.7, caspase-3, Bcl-2, Bax-related gene expression were observed too. RESULTS: The half-life of effective medication is 13 d after injection of 32P colloids to the tumor stroma, in 1-6 groups, the tumor cell necrosis rates were 20%, 45%, 65%, 70%, 95% and 4%, respectively (F = 4.14-105.36, P<0.01). MVD were 38.5+/-4.0, 28.0+/-2.9, 17.0+/-2.9, 8.8+/-1.5, 5.7+/-2.3 and 65.0+/-5.2 (t = 11.9-26.1, P<0.01), respectively. Under TEM fairly differentiated Pc-3 cells were found. Thirty days after medication, tumors were shrunk and dried with scabs detached, and those in control group increased in size prominently with plenty of hypodermic blood vessels. In all animals the ILN were enlarged but in medicated animals they appeared later and smaller than those in control group. The extent of irradiative injury in ILN was positively correlated to the dosage of medication. Typical tumor cell apoptosis could be found under TEM in animals with intra-tumoral injection of low dosed 32P colloids. The peak of apoptosis occurred in 2.96 MBq group and 24 h after irradiation. In the course of irradiation-induced apoptosis, the value of Bcl-2/Bax was down regulated; Apo2.7 and caspase-3 protein expression were prominently increased dose dependently. CONCLUSION: 32P colloids intra-tumor injection having prominent anticancer effectiveness may reveal the ability of promoting cell differentiation. The low dose 32P colloids may induce human pancreatic carcinoma Pc-3 implanted tumor cell apoptosis; Apo2.7, caspase-3, Bcl-2 and Bax protein participated in regulating the process of irradiation induced cell apoptosis.

Animals↗

PubMed2005

pFind: a novel database-searching software system for automated peptide and protein identification via tandem mass spectrometry.

SUMMARY: Research in proteomics requires powerful database-searching software to automatically identify protein sequences in a complex protein mixture via tandem mass spectrometry. In this paper, we describe a novel database-searching software system called pFind (peptide/protein Finder), which employs an effective peptide-scoring algorithm that we reported earlier. The pFind server is implemented with the C++ STL, .Net and XML technologies. As a result, high speed and good usability of the software are achieved.

Algorithms↗

PubMed2005

Preprocessing of tandem mass spectrometric data based on decision tree classification.

In this study, we present a preprocessing method for quadrupole time-of-flight (Q-TOF) tandem mass spectra to increase the accuracy of database searching for peptide (protein) identification. Based on the natural isotopic information inherent in tandem mass spectra, we construct a decision tree after feature selection to classify the noise and ion peaks in tandem spectra. Furthermore, we recognize overlapping peaks to find the monoisotopic masses of ions for the following identification process. The experimental results show that this preprocessing method increases the search speed and the reliability of peptide identification.

Amino Acid Sequence↗

PubMed2005

[Skip metastasis to mediastinal lymph nodes: clinical significance and prognosis in stage III non-small cell lung cancer].

OBJECTIVE: To analyze the significance and prognosis of skip metastasis to mediastinal lymph nodes in stage III non-small cell lung cancer (NSCLC). METHODS: The data of 65 patients who underwent resection for NSCLC with a pN(2)-stage were analyzed retrospectively. Twenty-one of these patients (32.3%), showing no metastatic involvement of hilar (N(1)) lymph nodes, were compared to the remaining 44 patients with infiltration of hilar nodes (N(1)) as well as N(2) nodes. Software SPSS 10.0 was used for statistical analysis. RESULTS: Multivariate analysis showed no statistically significant difference between the skip metastasis and the continuous N(2) group regarding sex, age, histology, location, and T-or M-status. In the skip metastasis group, mediastinal node metastasis was found in >or=2 region in 16 patients (36.4%) and in continuous N(2) group in 2 patients (9.5%, chi(2) = 8.571, P = 0.036). The 5-year survival rate of pN(2) patients with skip metastasis was 41% compared to 21% in patients with involvement of N(1) and N(2) nodes (P = 0.022 6), and the mean survival time was 44 months and 26 months respectively. CONCLUSIONS: pN(2) patients with mediastinal lymph node skip metastasis have a more favorable prognosis compared to pN(2) patients with continuous infiltration of the regional lymph nodes. Skip metastasis is an independent prognostic factor for survival. Skip metastasis may represent a subgroup of pN(2) classification.

Aged↗

PubMed2005

[Experimental study about the protective effect of Ginkgo biloba extract on renal acute ischemia-reperfusion injury in rats].

OBJECTIVE: To study the protective effect of Ginkgo biloba extract(EGb) on the kidney in the case of ischemia-reperfusion injury. METHOD: The model of renal ischemia-reperfusion injury in male rats was made by ligation of left renal artery for 45 min and 4 h of reperfusion. The rats with pretreament were fed with EGb prior to operation. The change of MDA, SOD, Na+-K+-ATPase, Ca2+-ATPase in kidney and BUN, Cr in plasma were determined. The renal pathologic changes were observed. RESULT: After ischemia-reperfusion, the content of MDA in renal cortex and the levels of BUN, Cr in plasma were increased,the activity of SOD,Na+-K+-ATPase, Ca2+-ATPase in renal cortex were decreased, and the phathological changes induced by ischemia-reperfusion in renal tissues were observed clearly. The pretreatment of rats with EGb coued significantly prevente the reduction of SOD, Na+-K+-ATPase, Ca2+-ATPase activity in renal cortex and the increase of MDA content in renal cortex, decrease the concenration of BUN, Cr in plasma. The pathological changes of proximal tubular cells in rats kidneys induced by ischemia-reperfusion were also prevented by the pretreatment with EGb. CONCLUSION: EGb can protect rats from renal injuries caused by ischemia-reperfusion.

Animals↗

PubMed2004

Transabdominal ultrasonography in preoperative staging of gastric cancer.

AIM: To investigate the value of transabdominal ultrasonography (US) in the preoperative staging of gastric cancer. METHODS: A total of 198 patients with gastric cancer underwent preoperatively transabdominal US, depth of tumor infiltration was assessed in 125 patients, and lymph node metastasis was assessed in 106 patients. RESULTS: The staging accuracy of transabdominal US was 55.6%, 75.0%, 87.3% and 71.1% in T1, T2, T3 and T4 carcinomas, respectively. The overall accuracy was 77.6%. The detection rate for pancreatic invasion and liver invasion was 77.4%, 71.4%, respectively. The sensitivity, specificity, accuracy of transabdominal US in assessment of lymph node metastasis were 77.6%, 64.1%, 72.6%, respectively. Various shapes such as round, ovoid, spindle were encountered in benign and malignant lymph nodes. Majority of both benign and malignant lymph nodes were hyperechoic and had a distinct border. Benign lymph nodes were smaller than malignant lymph nodes in length and width (P = 0.000, 0.005). Irregular shape, fusional shape, infiltrative signs, inhomogenous echo were seen mainly in malignant lymph nodes (P = 0.045, 0.006, 0.027, 0.006). CONCLUSION: Transabdominal US is useful for preoperative staging in gastric cancer, although it is difficult to differentiate benign from malignant lymph nodes.

Abdomen↗

PubMed2004

Exploiting the kernel trick to correlate fragment ions for peptide identification via tandem mass spectrometry.

MOTIVATION: The correlation among fragment ions in a tandem mass spectrum is crucial in reducing stochastic mismatches for peptide identification by database searching. Until now, an efficient scoring algorithm that considers the correlative information in a tunable and comprehensive manner has been lacking. RESULTS: This paper provides a promising approach to utilizing the correlative information for improving the peptide identification accuracy. The kernel trick, rooted in the statistical learning theory, is exploited to address this issue with low computational effort. The common scoring method, the tandem mass spectral dot product (SDP), is extended to the kernel SDP (KSDP). Experiments on a dataset reported previously demonstrate the effectiveness of the KSDP. The implementation on consecutive fragments shows a decrease of 10% in the error rate compared with the SDP. Our software tool, pFind, using a simple scoring function based on the KSDP, outperforms two SDP-based software tools, SEQUEST and Sonar MS/MS, in terms of identification accuracy. SUPPLEMENTARY INFORMATION: http://www.jdl.ac.cn/user/yfu/pfind/index.html

Algorithms↗

PubMed2004

[Mathematical protocol for radiofrequency ablation of liver tumors and its clinical application].

OBJECTIVE: To develop a preoperative protocol for ultrasonography-guided percutaneous radiofrequency ablation (RFA) on liver tumors larger than 3.5 cm in diameter based on mathematical models and clinical experience, and to evaluate its ablated effect compared to the previous non-math method. METHODS: One hundred and twenty-five patients with 80 primary and 55 secondary liver tumors (4.7 +/- 0.9 cm in diameter, ranged from 3.6 - 7.0 cm) were enrolled in this study, of which the first 22 patients (23 tumors) had been treated empirically before the mathematical model was set up and were referred as the non-math group. The rest 103 patients (112 tumors) were treated based on the mathematical model and referred as the math group. Based on principle of overlapping spheres, a mathematical analysis was performed to investigate how multiple ablation spheres could overlap and cover larger tumors most efficiently. Some mathematical models such as regular prism and regular polyhedron model were chosen to estimate the mathematical protocol which included least ablation (sphere) number and optimal overlapping mode required to adequately ablate a large and spherical target lesion. The target volume consisted of the tumor plus a 0.5 - 1 cm tumor-free margin. The operation method for electrode placement was also described. RESULTS: The procedure success rate for the math group was 88.4% (99/112), local recurrence rate and estimated mean time until local recurrence were 25.9% (29/112) and 17.5 months, respectively. While for the non-math group the results were 52.2% (12/23) (P < 0.01), 56.5% (13/23) (P < 0.05) and 11.9 months (P < 0.05), respectively. The therapy results in the math group were much better than in the non-math group. CONCLUSION: This study provides theoretic basis and clinical guidance for RFA therapy for liver tumors larger than 3.5 cm. These results could be used to reduce local recurrence rate and improve treatment response.

Adult↗

PubMed2004

A glycosynapse in myelin?

Myelin, the multilayered membrane which surrounds nerve axons, is the only example of a membranous structure where contact between extracellular surfaces of membrane from the same cell occurs. The two major glycosphingolipids (GSLs) of myelin, galactosylceramide (GalC) and its sulfated form, galactosylceramide I(3)-sulfate (SGC), can interact with each other by trans carbohydrate-carbohydrate interactions across apposed membranes. They occur in detergent-insoluble lipid rafts containing kinases and thus may be located in membrane signaling domains. These signaling domains may contact each other across apposed extracellular membranes, thus forming glycosynapses in myelin. Multivalent forms of these carbohydrates, GalC/SGC-containing liposomes, or galactose conjugated to albumin, have been added to cultured oligodendrocytes (OLs) to mimic interactions which might occur between these signaling domains when OL membranes or the extracellular surfaces of myelin come into contact. These interactions between multivalent carbohydrate and the OL membrane cause co-clustering or redistribution of myelin GSLs, GPI-linked proteins, several transmembrane proteins, and signaling proteins to the same membrane domains. They also cause depolymerization of the cytoskeleton, indicating that they cause transmission of a signal across the membrane. Their effects have similarities to those of anti-GSL antibodies on OLs, shown by others, suggesting that the multivalent carbohydrate interacts with GalC/SGC in the OL membrane. Communication between the myelin sheath and the axon regulates both axonal and myelin function and is necessary to prevent neurodegeneration. Participation of transient GalC and SGC interactions in glycosynapses between the apposed extracellular surfaces of mature compact internodal myelin might allow transmission of signals throughout the myelin sheath and thus facilitate myelin-axonal communication.

Actins↗

PubMed2004

[Risk factors scoring system for predicting acute respiratory failure after general thoracic surgery].

OBJECTIVE: To establish a scoring system for predicting the occurrence of postoperative acute respiratory failure (ARF) after general thoracic surgery. METHODS: Eighty-five cases of post-operative ARF and 300 postoperative cases without ARF, treated from July 1981 to December 1998, were retrospectively analyzed by means of Logistic regression. The main risk factors were determined, and scores were allocated to the corresponding interval respectively, so as to establish the scoring system. RESULTS: Ten items were included in the system: lung function (existence of symptom of shortness of break, forced expiratory volume in one second (FEV1)), arterial blood gas index (arterial oxygen pressure (PaO2)), nutritional status, cigarette-smoking index, impact of operation (blood loss, influence on the lung), complicating diseases (asthma, myasthenia gravis), and age. The sensitivity and specificity of this system was 67.05 percent and 90.33 percent respectively. CONCLUSION: This newly established scoring system for predicting postoperative ARF has the advantage of convenience and objectivity.

Aged↗

PubMed2003

[Helicobacter pylori inhibits cell growth and induces G1/S arrest in AGS gastric epithelial cells].

OBJECTIVE: To observe the effects of Helicobacter pylori (H. pylori) on growth and cell cycle progression of AGS gastric epithelial cells. METHODS: AGS cells and H. pylori were co-cultured for 1 - 4 days. Vital cell numbers were counted by heamatocounter. Apoptosis was detected by fluorescence stain of cell nucleus and DNA agarose electrophoresis. Cell cycle was analyzed by flow cytometry technique. RESULTS: During co-culture of AGS cells and H. pylori, cell growth inhibition was observed. H. pylori induces apoptosis and cell cycle arrest from G1 to S phase accompanied by high expression of cyclinD1. CONCLUSION: Exposure of gastric epithelial cells to H. pylori causes block of G1 to S progression of cell cycle and alters expression of cyclinD1. The cell cycle arrest and the associated induction of apoptosis are responsible for the growth inhibition of gastric epithelial cells caused by H. pylori.

Apoptosis↗

PubMed2003

[Biologic significance of thyroid transcription factor-1 and surfactant protein expression in pulmonary sclerosing hemangioma].

OBJECTIVE: To investigate the biologic significance of thyroid transcription factor-1 (TTF-1) and surfactant protein A (SP-A) and SP-B expression in pulmonary sclerosing hemangioma (PSH). METHODS: TTF-1, SP-A, SP-B, epithelial membrane antigen (EMA), pancytokeratin (AE(1)/AE(3)), vimentin, CK7, CK5/6, calretinin, S-100, neuron specific enolase (NSE), synaptophysin (Syn), chromogranin A (CgA), CD(34), Factor VIII and smooth muscle actin (SMA) in 42 patients with PSH were examined with immunohistochemistry, while samples from 10 patients were also observed by electron microscope. RESULTS: Histopathologically, PSH mainly consisted of both surface lining cuboidal cells and pale polygonal cells. Both of them were stained with TTF-1, EMA and vimentin, whereas SP-A, SP-B, pancytokeratin and CK7 were only positive in surface lining cuboidal cells. Syn, NSE, S-100 and CgA showed scattered positivity in these cells. There was no significant difference in the expressions of TTF-1 and EMA between these two cell types (P > 0.05), whereas the difference was significant in the expression of vimentin (P < 0.01). The ultrastructural features cannot differentiate these two cells by electron microscope. CONCLUSIONS: It is suggested that PSH is derived from primitive respiratory epithelium, and both surface lining cuboidal cells and pale polygonal cells were entity cells of the tumor. Examination of different immunohistochemical markers including TTF-1, SP-A, SP-B, pancytokeratin, EMA and vimentin is helpful in the diagnosis and differential diagnosis of PSH.

Adolescent↗

PubMed2003

[Pathogenicity and treatment of acute respiratory distress syndrome after thoracotomy].

OBJECTIVE: To investigate the causes of acute respiratory distress (ARDS) after thoracotomy and to find out the measures to prevent ARDS. METHODS: The characteristics of incidence, pathogenicity and treatment of ARDS after thoracotomy in 31 patients were analysed. RESULTS: The patients who had chronic obstructive pulmonary disease, long history of smoking, hypertension were prone to ARDS. Injury to lung in operation, shock and pulmonary infection probably caused ARDS. Clearing away respiratory tract secretion, preserving of a clear airway, controlling pulmonary infection, alleviating pneumonedema by diuresis, early executing tracheotomy or mechanic assistant ventilation by tracheointubation were keys to rescuing patients successfully. CONCLUSIONS: It is suggested that multi factors were related to ARDS after thoracotomy. Shock, injury to lung in operation, pulmonary infection, are important factors that lead to post-operative ARDS after thoracotomy. Early treatment can reduce mortality of ARDS.

Adult↗

PubMedDate not supplied

Predicting molecular formulas of fragment ions with isotope patterns in tandem mass spectra.

A number of different approaches have been proposed to predict elemental component formulas (or molecular formulas) of molecular ions in low and medium resolution mass spectra. Most of them rely on isotope patterns, enumerate all possible formulas for an ion, and exclude certain formulas violating chemical constraints. However, these methods cannot be well generalized to the component prediction of fragment ions in tandem mass spectra. In this paper, a new method, FFP (Fragment ion Formula Prediction), is presented to predict elemental component formulas of fragment ions. In the FFP method, the prediction of the best formulas is converted into the minimization of the distance between theoretical and observed isotope patterns. And, then, a novel local search model is proposed to generate a set of candidate formulas efficiently. After the search, FFP applies a new multiconstraint filtering to exclude as many invalid and improbable formulas as possible. FFP is experimentally compared with the previous enumeration methods, and shown to outperform them significantly. The results of this paper can help to improve the reliability of de novo in the identification of peptide sequences.

Algorithms↗