Biomedical subjects

Han Chen

Publications and source records attributed to Han Chen.

At least 37 records · Page 2Linked to original sources

PubMed2005

[The effect of cervical circumference, lingual height and lingual width on the obstructive sleep apnea-hypopnea syndrome].

OBJECTIVE: To investigate the relation between the obstructive sleep apnea syndrome and the metrical value of the patient's cervical circumference, lingual height and lingual width. METHOD: The clinical and radiographic data of 33 (OSAHS) patients were retrospectively analyzed, the value of cervical circumference was direct manual measurement, the value of lingual height, lingual width was indirect measured through X-ray radiography of Iodic oil, and selected 33 normal adult as control group. RESULT: The mean of cervical circumference, lingual height and lingual width of OSAHS group have significant difference to normal control group respectively, the value of OSAHS group remarkably higher than control group. CONCLUSION: Cervical circumference, lingual height and lingual width make important effect on pathogenesis of OSAHS.

Adult↗

PubMed2004

Synthesis and biological evaluation of thiazolidine-2,4-dione and 2,4-thione derivatives as inhibitors of translation initiation.

In an effort to generate novel translation initiation inhibitors for cancer therapy, a series of 2'-benzyloxy-5'-substituted-5-benzylidene-thiazolidine-2,4-thione and dione derivatives was synthesized and evaluated for activity in translation initiation specific assays. Several candidates of the 5-benzylidene-thiazolidine-2,4-diones (3c, 3d, and 3f) and -thiones (2b, 2e, and 2j), inhibit cell growth with low microM GI(50) mediated by inhibition of translation initiation, which involves partial depletion of intracellular Ca(2+) stores and strong phosphorylation of eIF2alpha.

Antineoplastic Agents↗

PubMed2004

Novel arylsulfoanilide-oxindole hybrid as an anticancer agent that inhibits translation initiation.

Structure-activity relationship studies of substituted arylsulfoanilides as antiproliferatives, which are mediated by the partial depletion of intracellular Ca(2+) stores, resulted in the identification of compounds with micromolar activity against lung cancer cells in a growth inhibition assay. Incorporating the substitution pattern of the best arylsulfoanilides onto the 3-phenyloxindole scaffold resulted in a potent arylsulfoanilide-oxindole hybrid, 27. Compound 27 inhibits cancer cell growth by partial depletion of intracellular Ca(2+) stores and phosphorylation of eIF2alpha.

Aniline Compounds↗

PubMed2004

[Surgical treatment for the giant hepatic carcinomas occupying the central part of the liver].

OBJECTIVE: To evaluate the techniques and the effects of surgical resection of giant hepatic carcinomas which occupied the central part of the liver. METHODS: A retrospective study was carried out of hepatectomies performed for central giant hepatic carcinomas. The hepatic tumors included in this study were hepatocellular carcinomas, cholangiocarcinomas and hepatic metastases which situated in the central part of the liver (segment IV, V, VIII, I) with a diameter of larger than 10 cm and involved hepatocaval confluence, retrohepatic inferior vena cava (IVC) as well as hepatic portal. RESULTS: A total of 40 central giant hepatic carcinomas were successfully resected, with a mean diameter of 13.6 cm (range 10.5-19.0 cm). The types of the hepatectomies conducted were as follows: extended mid-hepatectomy in 9 cases, atypical mid-hepatectomy in 13 cases, extended left hepatectomy in 13 cases, total caudatectomy plus extended left hepatectomy in 3 cases and extended right hepatectomy in 2 cases. The mean operation time was 197 min (range 90 - 380 min) and the mean intraoperative blood lose 1,596 ml (range 300-11,000 ml), with operative mortality and morbidity being 0 and 20%, respectively. The postoperative 1, 3 and 5 year survival rates for the patients were 88%, 56% and 28%, respectively. CONCLUSIONS: The hepatic carcinomas of central type, when larger than 10 cm in diameter, frequently involves all the hepatic portal, hepatocaval confluence and retrohepatic IVC. Surgical resection of this kind of tumor, though sophisticated in technique, is safe and effective and, therefore, the first choice of the treatments.

Adult↗

PubMed2004

Structure-activity requirements for the antiproliferative effect of troglitazone derivatives mediated by depletion of intracellular calcium.

Depletion of calcium from the endoplasmic reticulum has shown to affect protein synthesis and cell proliferation. The anticancer effect of troglitazone was reported to be mediated by depletion of intracellular calcium stores resulting in inhibition of translation initiation. The unsaturated form of troglitazone displays similar anticancer properties in vitro. In this letter, we report our findings on the minimum structural requirements for both compounds to retain their calcium release and antiproliferative activities.

Antineoplastic Agents↗

PubMed2004

Synthesis of fluorescein labeled 7-methylguanosinemonophosphate.

Binding of eIF4E to the cap structure (m(7)GpppN) plays a critical role in mRNA translation. To study the interaction between eIF4E and cap, and to identify small molecule inhibitors of their binding, we synthesized a fluorescent-labeled cap analogue and used it to develop a fluorescence-polarization assay. This preliminary communication describes the synthesis of a fluorescein labeled 7-methylguanosinemonophosphate, and its dose dependent binding to purified human eIF4E as demonstrated by the fluorescence polarization assay.

Eukaryotic Initiation Factor-4E↗

PubMed2004

3,3-diaryl-1,3-dihydroindol-2-ones as antiproliferatives mediated by translation initiation inhibition.

A series of substituted 3,3-diphenyl-1,3-dihydro-indol-2-ones was synthesized from the corresponding isatins. The compounds were studied for cell growth inhibition mediated by partial depletion of intracellular Ca2+ stores that leads to phosphorylation of eIF2alpha. The diphenyloxindole (1) showed mechanism-specific antiproliferative activity that was comparable to known translation initiation inhibitors such as clotrimazole or troglitazone. SAR studies identified m'-tert-butyl and o-hydroxy substituted diphenyloxindole (25) as a lead compound for Ca2+-depletion-mediated inhibition of translation initiation.

Antineoplastic Agents↗

PubMed2004

[Percutaneous radiofrequency ablation for liver cancer located in hepatis].

OBJECTIVE: To explore the feasibility, effect and problems of percutaneous radiofrequency ablation (PRFA) performed for small liver cancer located in hepatis. METHODS: Twenty-one patients, who had small primary or metastatic liver cancer confirmed clinically or pathologically that were located in hepatis and less than 5 cm, were performed PRFA between April 2000 and October 2002. All patients were followed up to examine the value of AFP, MRI or CT. Kaplan-Meier estimation was used for the disease-free survival rate and the long-term survival rate. RESULTS: The rate of AFP positive down to negative was 77.8% (7/9). The complete necrosis rate was 90.5% (19/21). The peri-tumor recurrence-free survival rates of 0.5-, 1-, 1.5-, 2-year were all 94.7%. The distant recurrence-free survival rates of 0.5-, 1-, 1.5-, 2-year were 90.0%, 77.1%, 77.1% and 77.1% respectively. The whole survival rates of 0.5-, 1-, 1.5- and 2-year were 89.2%, 82.8%, 82.8% and 55.2% respectively. CONCLUSIONS: Small liver cancer located in hepatis was not the contra-indication of PRFA. If the puncture point and route is selected properly, electrodes outspreaded exactly and the range of heating controlled appropriately, PRFA is an effective method and of less complication rate for small liver cancer located in hepatis. Sometimes, PRFA can be combined with TACE for those tumors of the diameter larger than 3 cm.

Adult↗

PubMed2004

[Partial hepatectomy with skeletonization of the hepatoduodenal ligament for hilar cholangiocarcinoma].

OBJECTIVE: To sum up author's experience and to define the role of partial hepatectomy with skeletonization resection in the treatment of hilar cholangiocarcinoma. METHODS: Between January 1999 and December 2001, 67 patients underwent exploration in our hospital. The clinical records of these patients were reviewed. RESULTS: Sixty-five (97%) patients underwent surgical resection. Forty-nine patients (73%) had curative resection [22 skeletonization resection (SR), and the other 27 undergone SR combined with partial hepatectomy]. According to the Bismuth-Corlett classification, tumors were classified into four types. SR was performed in type I (5 cases) and type II (17 cases). Right lobectomy with right caudate lobectomy was performed in type IIIa (6 cases), left lobectomy with left caudate lobectomy in type IIIb (15 cases). Right lobectomy with whole caudate lobectomy (3 cases), left lobectomy with whole caudate lobectomy (9 cases), and quadrate lobectomy (2 cases) were undertaken in type IV. We successfully did SR and left lobectomy with whole caudate lobectomy in 2 patients (3%) who had suffered palliative biliary cancer resection and cholangiojejunostomy before. Eight patients (12%) had local resection of the tumor with Roux-en-Y hepaticojejunostomy reconstruction and intrahepatic bile ducts support. Two patients (3%) had palliative biliary drainage. Combined portal vein resection was performed in 13 (20%) patients and hepatic artery resection in 27 (40.3%). Twenty-four (35.8%) patients had no postoperative complications, and 20 (30.2%) patients developed major complications. Of the 20 patients with major complications 14 recovered; the remaining 6 patients died of liver-renal failure with other organ failure or of heart attack, intraabdominal bleeding, and gastrointestinal bleeding in 7, 12, 14, 42, 57, or 89 days after surgery. Thirty days operative mortality was 4.5%. The median survival of patients with curative resection was 16 months (ranging from 1 to 41 months), while the median survival with palliative operation was 7 months (ranging from 1 to 16 months). CONCLUSIONS: Partial hepatectomy with skeletonization resection for hilar cholangiocarcinoma can be performed with acceptable morbidity and mortality. For curative treatment of hilar cholangiocarcinoma, Caudate lobectomy is always recommended in Bismuth type III/IV.

Adult↗

PubMed2004

[Significance of typing of tumor thrombi in determination of treatment and assessment of prognosis of hepatocellular carcinoma with tumor thrombi in the portal vein].

OBJECTIVE: To evaluate the benefit of typing of tumor thrombi in determining treatment plan and assessing prognosis of hepatocellular carcinoma (HCC) with tumor thrombi in the portal vein. METHODS: The clinical data of 84 patients of HCC with portal vein tumor thrombi admitted from Jan. 2000 to Jan. 2003 were analyzed retrospectively. The patients, 75 males and 9 females, aged 47 (28 - 70), were divided into 4 groups, groups I - IV, according to imaging examination of the tumor thrombi. The median survival periods and effectiveness of treatment, including surgical resection and non-surgical treatment, were observed. RESULTS: The surgical resection rates were 64.7%, 83.8%, 31.4%, and 0 in the groups I - IV respectively (P = 0.912). The general median survival period of the patients undergoing surgery was 8.0 months, significantly longer than that of the patients receiving non-surgical treatment (4.0 months, P = 0.000 6). In different group of tumor thrombi type, the general median survival period of the patients undergoing surgery was significantly longer than that of the patients receiving non-surgical treatment. The median survival periods were 10.1, 7.2, 5.7 and 3.0 months for groups I (n = 17), II (n = 26), III (n = 35) and groups IV (n = 6) respectively, with significant difference between any 2 groups (all P = 0.000 1). CONCLUSION: Typing of tumor thrombi helps determine the treatment plan and assess the prognosis of hepatocellular carcinoma patients with tumor thrombi in the portal vein.

Adult↗

PubMed2004

Culture-independent analysis of fecal enterobacteria in environmental samples by single-cell mRNA profiling.

A culture-independent method called mRNA profiling has been developed for the analysis of fecal enterobacteria and their physiological status in environmental samples. This taxon-specific approach determines the single-cell content of selected gene transcripts whose abundance is either directly or inversely proportional to growth state. Fluorescence in situ hybridization using fluorochrome-labeled oligonucleotide probes was used to measure the cellular concentration of fis and dps mRNA. Relative levels of these transcripts provided a measure of cell growth state and the ability to enumerate fecal enterobacterial cell number. Orthologs were cloned by inverse PCR from several major enterobacterial genera, and probes specific for fecal enterobacteria were designed using multiple DNA sequence alignments. Probe specificity was determined experimentally using pure and mixed cultures of the major enterobacterial genera as well as secondary treated wastewater samples seeded with pure culture inocula. Analysis of the fecal enterobacterial community resident in unseeded secondary treated wastewater detected fluctuations in transcript abundance that were commensurate with incubation time and nutrient availability and demonstrated the utility of the method using environmental samples. mRNA profiling provides a new strategy to improve wastewater disinfection efficiency by accelerating water quality analysis.

Bacterial Outer Membrane Proteins↗

PubMed2004

[Transcatheter hepatic arterial chemoembolization and thymosin alpha1 in postoperative treatment of hepatocellular carcinoma].

OBJECTIVE: To observe the effect of postoperative transcatheter hepatic arterial chemoembolization (TACE) and thymosin alpha(1) (T(alpha1)) treatment on recurrence of hepatocellular carcinoma (HCC). METHODS: From Jan 2000 to Dec 2002, 57 patients with HCC were randomly divided into three groups: group A (n = 18) received hepatectomy plus postoperative TACE and T(alpha1), group B (n = 23) received hepatectomy plus postoperative TACE and group C (n = 16) received hepatectomy only. The recurrence rate, the time to tumor recurrence and the median survival for the three groups were investigated. RESULTS: For group A, B and C, the 1 year recurrence rate was 83.3%, 87.0% and 87.5% (P = 0.926), respectively. The time to tumor recurrence was 7.0, 5.0 and 4.0 months (P = 0.039), respectively. The median survival was 10.0, 7.0 and 8.0 months (P = 0.002), respectively. CONCLUSION: Postoperative TACE plus Talpha(1) treatment for HCC patients does not decrease the recurrence rate but may delay its occurrence and prolong surviving time.

Adjuvants, Immunologic↗

PubMed2004

Modified Sugiura procedure for the management of 160 cirrhotic patients with portal hypertension.

BACKGROUND: Portal hypertension is a common disease with a high mortality and serious effect on the life quality of patients. Presently, shunt and disconnection are commonly used for surgical treatment of portal hypertension. The aim of this study was conducted to analyze the results of a modified Sugiura procedure for the management of 160 cirrhotic patients with portal hypertension. METHODS: The results of a modified Sugiura procedure for the treatment of 160 cirrhotic patients with portal hypertension from January 1991 to July 2002 were retrospectively analyzed. RESULTS: The operative mortality for the procedure was zero. Postoperative intra-abdominal bleeding was noted in 2 patients, drowned lung in 1, pneumonia in 1, and splenic venous thrombosis in 4. Of the 160 patients, 157 (98%) were followed up from 6 months to 11.5 years. Of the 157 patients, only one died of hepatic coma 6 years after operation, and 3 of rebleeding. The absolute and relative survival rates were 97.5%(156/160) and 99%(159/160), respectively. The absolute and relative occurrence rates of hepatic coma were 2.5%(4/160) and 0.6%(1/157), respectively. The absolute and relative occurrence rates of rebleeding were 3.8%(6/160) and 1.9%(3/157), respectively. In 96 of 116 Child B patients (82.8%), liver function improved from preoperative class B to A 3 months after operation. Sixty-five patients were subjected to gastroscopy and 22 patients, esophageal barium photography 6 months after operation. Gastro-esophageal varices disappeared in 56 patients (64.4%, 56/87), obviously improved in 30 (34.5%, 30/87), and unchanged in 1 (1.2%, 1/87). The occurrence rate of portal hypertensive gastropathy (PHG) was 13.9%(9/65). CONCLUSION: Our results showed that the modified Sugiura procedure is effective in the treatment of portal hypertension, with a low rate of operative complication, bleeding recurrence, and hepatic coma.

Adult↗

PubMed2004

[Focal nodular hyperplasia of the liver: a clinical study of 48 patients].

OBJECTIVE: To study the diagnosis and proper treatment of focal nodular hyperplasia (FNH) of the liver. METHODS: Forty-eight consecutive patients with FNH treated from 1998 to 2002 were analyzed. Clinical, pathologic, and preoperative imaging findings of FNH all proved surgically and pathologically were retrospectively reviewed. RESULTS: Most of the patients were asymptomatic and serum test was normal. Helical multiphasic liver CT and MR imaging demonstrated characteristic features in 25 patients. Histologically, characteristic scar-like tissues were found in 29 cases. The overall complication rate was 2.1% and there was no death. No recurrence was observed after follow-up of 4 years after operation. CONCLUSION: There is little evidence for an increased risk for FNH in people using modern oral contraceptives, while characteristic imaging features exist in helical multiphasic liver CT and MR imaging. Operation is the optimal treatment for FNH, but for proved FNH less than 5 cm and asymptomatic patients, close periodic followed up should be done.

Adolescent↗

PubMed2003

Synthesis of new 2,4-Diaminopyrido[2,3-d]pyrimidine and 2,4-Diaminopyrrolo[2,3-d]pyrimidine inhibitors of Pneumocystis carinii, Toxoplasma gondii, and Mycobacterium avium dihydrofolate reductase.

A concise new route allowing easy access to five previously unreported 2,4-diamino-6-(substituted benzyl)pyrido[2,3-d]pyrimidines (2a-e) was developed, involving condensation of 2,4-dipivaloylamino-5-bromopyrido[2,3-d]pyrimidine (6) with an organozinc halide in the presence of a catalytic amount of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II).CH(2)Cl(2), followed by removal of the pivaloyl groups with base. Also prepared via a scheme based on the Taylor ring expansion/ring annulation synthesis were three heretofore undescribed 2,4-diamino-5-(substituted benzyl)-7H-pyrrolo[2,3-d]pyrimidines (3b-c). Standard spectrophotometric assays were used to compare the ability of 2a-e and 3b-c to inhibit dihydrofolate reductase (DHFR) from Pneumocystis carinii, Toxoplasma gondii, and Mycobacterium avium, three examples of opportunistic pathogens to which AIDS patients are highly vulnerable because of their immunocompromised state. For comparison, 13 previously untested 2,4-diamino-6-(substituted benzyl)quinazolines (17a-m) were also evaluated as inhibitors of these enzymes, as well as the enzyme from rat liver. None of the quinazolines or pyridopyrimidines tested was more potent against the P. carinii enzyme than the structurally related reference compound piritrexim (1), and none showed selectivity for the P. carinii enzyme over the rat enzyme. One of the pyridopyrimidines (2c) showed 10-fold selectivity for T. gondii versus rat DHFR, and two of them (2b, 2c) showed selectivity for the M. avium enzyme. However, this gain in species selectivity was achieved at the cost of decreased in potency, as has been noted with many other lipophilic DHFR inhibitors.

Animals↗

PubMed2003

Single-cell protein profiling of wastewater enterobacterial communities predicts disinfection efficiency.

The efficiency of enterobacterial disinfection is dependent largely on enterobacterial community physiology. However, the relationship between enterobacterial community physiology and wastewater processing is unclear. The purpose of this study was to investigate this relationship. The influence of wastewater treatment processes on enterobacterial community physiology was examined at the single-cell level by using culture-independent methods. Intracellular concentrations of two conserved proteins, the growth-related protein Fis and the stationary-phase protein Dps, were analyzed by epifluoresence microscopy of uncultivated cells by using enterobacterial group-specific polyclonal fluorochrome-coupled antibodies. Enterobacterial single-cell community protein profiles were distinct for different types of biological treatment. The differences were not apparent when bulk methods of protein analysis were used. Trickling filter wastewater yielded Fis-enriched communities compared to the communities in submerged aeration basin wastewater. Community differences in Fis and Dps contents were used to predict disinfection efficiency. Disinfection of community samples by heat exposure combined with cultivation in selective media confirmed that enterobacterial communities exhibited significant differences in sensitivity to disinfection. These findings provide strategies that can be used to increase treatment plant performance, reduce the enterobacterial content in municipal wastewater, and minimize the release of disinfection by-products into receiving water.

Bacterial Proteins↗

PubMed2003

[Percutaneous hepatic puncture radio frequency ablation in the treatment of hepatocellular carcinoma].

OBJECTIVE: To observe the curative effect of percutaneous radio frequency ablation (PRFA) on hepatocellular carcinoma. METHODS: Under local or epidural anaesthesia, radio frequency electrodes were percutaneously introduced with ultrasound guide into the tumor in the liver for ablation. RESULTS: Among the 96 hepatic cancer lesions in 60 patients, 41 (42.7%) with diameter < 3.5 cm were ablated by one session. The effective rate (CR + PR) was 100% (41/41) with CR 92.6% (38/41) and PR 7.3% (3/41). During the 6 - 24 month follow up of these lesions, 36 (87.8%) of these 41 patients showed no recurrence by CT or MRI. Fifty-five (57.3%) lesions with diameter 3.5 cm < or = Phi < 12 cm were ablated by two or three sessions, with CR 3.6% (2/55), PR 67.3% (37/55) and CR + PR 70.9% (39/55) by CT or MRI in 1 to 3 months after the treatment. CONCLUSION: Percutaneous radio frequency ablation is effective on liver tumor with Phi < 3.5 cm. It is partly effective on lesions with 3.5 cm < or = Phi < 12 cm.

Adult↗

PubMed2003

[Surgical treatment of hepatocellular carcinoma with tumor thrombus in the inferior vena cava].

OBJECTIVE: To clarify the proper surgical procedure of treating hepatocellular carcinoma (HCC) with a tumor thrombus in the inferior vena cava (IVC). METHODS: Four patients with HCC with a tumor thrombus in the IVC underwent hepatectomy and thrombectomy. Following hepatectomy, tumor thrombus was removed by incising the wall of the IVC in 3 patients and from the hepatic vein in one patient. The 3 patients underwent thrombectomy under either hepatic vascular exclusion (HVE) or Satinsky's vascular clamping. RESULTS: All the operations were successful without operative death and major complications. The postoperative course was uneventful in 3 patients and pleural effusion occurred in one patient who needed thoracentesis. Follow-up showed 3 patients died after 30, 10 and 14 months, respectively, and one patient is alive for 7 months. CONCLUSIONS: HCC with tumor thrombus in the IVC is operable and the proper procedure is hepatectomy plus thrombectomy.

Carcinoma, Hepatocellular↗