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Biomedical subjects

Jin Gu

Publications and source records attributed to Jin Gu.

29 records · Page 2Linked to original sources
PubMed2004

Clinical features, diagnosis, treatment and prognosis of multiple primary colorectal carcinoma.

AIM: To investigate the clinical features, diagnosis, treatment and prognosis of multiple primary colorectal carcinomas (MPCC). METHODS: A retrospective analysis of 37 patients with MPCC from 1974 to 1998 was carried out. RESULTS: The incidence of MPCC was 2.74%(37/1 348) in patients with primary colorectal carcinomas, 15 cases of them were patients with synchronous carcinomas (SC) and 22 cases were diagnosed as metachronous carcinomas (MC). Most tumors were located in the right colon and rectum. Fifty-five percent (12/22) of MC were diagnosed within 3 years after tumor resection and 41%(9/22) of MC occurred after 8 years. Radical resections were performed in all patients except for 1 case. The 5-year survival rate of SC was 72.7%(8/11) and that of MC after the first cancer and second cancer was 71.4%(15/21) and 38.9%(7/18), respectively. CONCLUSION: The results indicate the importance of complete preoperative examination, careful intraoperative exploration and periodic postoperative surveillance. Early diagnosis and radical resection can increase survival rate of MPCC.

Adult↗
PubMed2004

An assessment of World Health Organization criteria for severe acute respiratory syndrome in patients with cancer.

BACKGROUND: The differential diagnosis of severe acute respiratory syndrome (SARS) in patients with cancer can be challenging. Although diagnostic criteria for SARS have been issued by the World Health Organization (WHO), simple adoption of the established criteria may lead to overdiagnosis in patients with cancer or to an increase in the risk of spreading SARS within cancer hospitals. METHODS: The authors report their experience with the exclusion and quarantine of patients with cancer during the peak of the SARS epidemic in Beijing, China. The patients included 4 males and 7 females with a median age of 66 years (range, 39-73 years). RESULTS: All 11 patients met the WHO diagnostic criteria for probable SARS. Among those 11 patients with probable SARS, only 1 had confirmed SARS; for the other 10 patients, the possibility of SARS infection was ruled out. CONCLUSIONS: Special attention must be paid to patients with cancer who have symptoms similar to those seen in SARS. Although the WHO diagnostic criteria for SARS should be widely accepted, they are not definite or practical in certain populations.

Adult↗
PubMed2004

Response of equatorial x-ray reflections and stiffness to altered sarcomere length and myofilament lattice spacing in relaxed skinned cardiac muscle.

Low angle x-ray diffraction measurements of myofilament lattice spacing (D(1,0)) and equatorial reflection intensity ratio (I(1,1)/I(1,0)) were made in relaxed skinned cardiac trabeculae from rats. We tested the hypothesis that the degree of weak cross-bridge (Xbr) binding, which has been shown to be obligatory for force generation in skeletal muscle, is modulated by changes in lattice spacing in skinned cardiac muscle. Altered weak Xbr binding was detected both by changes in I(1,1)/I(1,0) and by measurements of chord stiffness (chord K). Both measurements showed that, similar to skeletal muscle, the probability of weak Xbr binding at 170-mM ionic strength was significantly enhanced by lowering temperature to 5 degrees C. The effects of lattice spacing on weak Xbr binding were therefore determined under these conditions. Changes in D(1,0), I(1,1)/I(1,0), and chord K by osmotic compression with dextran T500 were determined at sarcomere lengths (SL) of 2.0 and 2.35 micro m. At each SL increasing [dextran] caused D(1,0) to decrease and both I(1,1)/I(1,0) and chord K to increase, indicating increased weak Xbr binding. The results suggest that in intact cardiac muscle increasing SL and decreasing lattice spacing could lead to increased force by increasing the probability of initial weak Xbr binding.

Actin Cytoskeleton↗
PubMed2003

Clinical application of radioimmunoguided surgery in colorectal cancer using 125I-labeled carcinoembryonic antigen-specific monoclonal antibody submucosally.

PURPOSE: The aim of this study was to evaluate the applicability of 125I-labeled carcinoembryonic antigen-specific monoclonal antibody CL58 in clinical radioimmunoguided surgery for colorectal cancer. METHODS: First, we tested the purity and affinity constant of CL58 and measured the binding affinity of CL58 to colorectal cancer cells and normal cells. Second, we injected 125I-labeled CL58 into nude mice with colon cancers. Then, samples from the tumor, blood, and normal tissues of injected mice were weighed and counted in a gamma-ray counter for assessment of biodistribution. Finally, we administered 125I-labeled CL58 submucosally in 29 patients with colorectal cancer via endoscope. Radioimmunoguided surgery was performed 3 to 14 days later with a portable gamma-detecting probe to obtain the counts in the target sites. Tumor-to-normal tissue ratio of 3 was taken as the lowest positive threshold value for primary lesions, wall infiltration, and lymph node metastasis. In addition, all the samples were examined by routine histopathology. Lymph nodes negative by routine histopathology were subjected to immunohistochemical staining with anticytokeratin to detect the lymphatic micrometastasis. RESULTS: The affinity constant of CL58 was 7.5 x 109 M-. Moreover, CL58 reacted strongly to the colorectal cancer cell lines, but not to the normal control cells. Furthermore, the tumor tissues showed significant intake of 125I-labeled CL58, as compared with that of normal tissues. The sensitivity of radioimmunoguided surgery in detecting primary lesions was 93.1 percent, and the specificity of radioimmunoguided surgery to correctly identify negative incisional margins for tumor infiltration was 95.5 percent. For the detection of lymphatic metastasis, the sensitivity of radioimmunoguided surgery was 92.0 percent and the specificity was 87.8 percent. The sensitivity of radioimmunoguided surgery in detecting lymph node metastasis was significantly higher when compared with traditional clinical methods (P = 0.0087). The specificity of radioimmunoguided surgery to identify negative incisional margins was also significantly higher when compared with traditional clinical methods (P = 0.0117). The sensitivity and specificity of radioimmunoguided surgery in detecting lymph nodes metastasis showed statistical significance, as compared with traditional clinical methods. Immunohistochemistry verified the existence of lymphatic micrometastasis in radioimmunoguided surgery-positive but histology-negative lymph nodes. CONCLUSIONS: This study indicates that radioimmunoguided surgery for colorectal cancer using 125I-labeled anticarcinoembryonic antigen monoclonal antibody submucosally enables surgeons to define lymphatic metastasis, thus successfully guiding surgeons in performing personalized radical operation.

Adult↗
PubMed2003

Angiography for diagnosis and treatment of colorectal cancer.

AIM: To evaluate the role of preoperative angiography in the diagnosis and treatment of colorectal cancer. METHODS: The authors performed selective arterial cannulation by Seldinger's method in 47 patients to locate the primary cancer and to diagnose metastasis to the liver. Each patient was then given intra-arterial regional chemotherapy, and received 5-fluorouracil (5-Fu, 1 000 mg), mitomycin C (MMC, 20 mg), and cisplatinum (CDDP, 80 mg). RESULTS: The location and shape of each tumor were observed, including metastatic tumors in the liver, in 42 of the 47 (89.4 %) patients. The site of the primary tumor was difficult to identify in 5 cases because the patients had a recurrence of cancer. Arterial chemotherapy was performed successfully in all patients. The authors recorded no partial or significant morbidity resulted from angiography. The only incident was bleeding from the artery puncture site in one patient, which was successfully stopped by general medication. CONCLUSION: Preoperative selective arterial angiography can help the diagnosis and locate primary tumors and to detect liver metastasis. At the same time, regional arterial chemotherapy can be an important form of preoperative therapy.

Adult↗
PubMed2003

Role of COX-2 in carcinogenesis of colorectal cancer and its relationship with tumor biological characteristics and patients' prognosis.

AIM: Recent clinical epidemiological studies have demonstrated the preventive effect of non-steroidal anti-inflammatory drugs (NSAIDs) against colorectal cancer. The underlying mechanism might be the inhibition of rate-limiting enzyme cyclooxygenase-2 (COX-2) in metabolism of arachidonic acid. The role of COX-2 in carcinogenesis of colorectal cancer and its relationship with tumor biological characteristics and patients' prognosis still remain unclear. This study was to investigate the role of COX-2 expression in carcinogenesis of colorectal cancer and its relationship with tumor biological characteristics and patients' prognosis. METHODS: A total of 139 colorectal cancers and 19 adenomas surgically treated in School of Oncology, Peking University, from January 1993 to September 2001 were retrospectively studied. COX-2 expression was detected with tissue microarray (TMA) and immunohistochemistry (IHC) procedure. The association between COX-2 expression and clinicopathological features and its influence on patients' prognosis were studied. RESULTS: COX-2 expression was strong in colorectal cancer, moderate in adenoma and weak in normal mucosa, which demonstrated statistically significant difference (chi(2)=46.997, P<0.001). COX-2 expression had no association with clinicopathological features such as gross type, differentiation, invasion depth, vessel emboli and TNM staging. Cox proportional hazards modeling analysis and Log rank test revealed no prognostic role of COX-2 expression in colorectal cancer patients. CONCLUSION: COX-2 may play an important role in the early stage of carcinogenesis, and its expression in colorectal cancer is not associated with clinicopathological features and patients' prognosis.

Adenocarcinoma↗
PubMed2003

[Expression of matrix metalloproteinase-9 and its complex in the urine of breast cancer patients].

OBJECTIVE: To investigate the expression and clinical significance of matrix metalloproteinase-9 and its complex in the urine of the patient with breast cancer. METHODS: Using substract gel electrophoresis and western-blot analysis, expressions of MMP-9 and MMP-9/NGAL complex in breast cancer (n = 97), breast benign (n = 41) and normal (n = 60) were observed. RESULTS: There MMP-9 and MMP-9/NGAL complex expressions were 76.29% and 64.95% in breast cancer, 46.34% and 43.90% in breast benign, and 23.33% in normal respectively. The MMP-9 and MMP-9/NGAL complex expressions were higher in breast cancer than those in breast benign and in normal (chi(2) = 7.456, P < 0.01). MMP-9 and MMP-9/NGAL complex expressions in urine of breast cancer had not any relationship with tumor size, TNM stage, patient age, menopause status as well as ER status, but was correlated to lymphatic node status (chi(2) = 5.206, P < 0.05). CONCLUSIONS: MMP-9 and MMP-9/NGAL complex expressions in urine are significant in estimating lymphatic node metastasis in breast cancer and a valuable early prognostic factors and screening in breast cancer.

Acute-Phase Proteins↗
PubMed2002

A model of cross-bridge attachment to actin in the A*M*ATP state based on x-ray diffraction from permeabilized rabbit psoas muscle.

A model of cross-bridges binding to actin in the weak binding A*M*ATP state is presented. The modeling was based on the x-ray diffraction patterns from the relaxed skinned rabbit psoas muscle fibers where ATP hydrolysis was inhibited by N-phenylmaleimide treatment (S. Xu, J. Gu, G. Melvin, L. C. Yu. 2002. Biophys. J. 82:2111-2122). Calculations included both the myosin filaments and the actin filaments of the muscle cells, and the binding to actin was assumed to be single headed. To achieve a good fit, considerable flexibility in the orientation of the myosin head and the position of the S1-S2 junction is necessary, such that the myosin head can bind to a nearby actin whereas the tail end was kept in the proximity of the helical track of the myosin filament. Hence, the best-fit model shows that the head binds to actin in a wide range of orientations, and the tail end deviates substantially from its lattice position in the radial direction (approximately 60 A). Surprisingly, the best fit model reveals that the detached head, whose location thus far has remained undetected, seems to be located close to the surface of the myosin filament. Another significant requirement of the best-fit model is that the binding site on actin is near the N terminus of the actin subunit, a position distinct from the putative rigor-binding site. The results support the idea that the essential role played by the weak binding states M*ATP <--> A*M*ATP for force generation lies in its flexibility, because the probability of attachment is greatly increased, compared with the weak binding M*ADP*P(i) <--> A*M*ADP*P(i) states.

Adenosine Monophosphate↗
PubMed2002

Neuroprotection by melatonin against ischemic neuronal injury associated with modulation of DNA damage and repair in the rat following a transient cerebral ischemia.

In the present study, double fluorescence staining combined with confocal laser scanning microscopy analysis were used to examine the effects of melatonin on ischemia-induced neuronal DNA strand breaks and its possible mechanisms in a transient middle cerebral artery (MCA) occlusion model. Results showed that melatonin dose-dependently reduced infarct areas and decreased both DNA double and single strand breaks (DSB and SSB) and enhanced cell viability in the peri-ischemic brain regions. Furthermore, Bcl-2 induction in the ischemic brain was further enhanced by melatonin treatment. Double staining analysis indicated that the cells costained for Bcl-2 and TdT-mediated-deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL), a DSB marker, displayed a relative regular morphology compared with the cells only stained with TUNEL. Transient ischemia induced an expression of excision repair cross-complementing factor 6 (ERCC6) mRNA, a gene essential for the preferential repair of nuclear excision repair, in the injured neurons. Double labeling showed that ERCC6 only co-localized with proliferating cell nuclear antigen (PCNA), a member of the nuclear excision repair complex, but not with TUNEL. Melatonin further and statistical significantly up-regulated ERCC6 mRNA expression in the peri-ischemic region of rat brains. The results suggest that neuroprotection by melatonin against ischemic injury may be related to modulation of apoptosis and DNA repair capacity.

Animals↗
PubMed2002

[Long-term results of preoperative regional intraarterial chemotherapy against colorectal cancer].

OBJECTIVES: To summarize the clinical experience of preoperative intraarterial chemotherapy (PRAC) and evaluate the long-term results of multimodality against colorectal cancer. METHODS: Seldinger procedure was used to intubate the tube to the artery branch which supplied blood to the tumor. The tumor was imaged to make sure the diagnosis and irrigate the chemotherapeutic drugs. Ten days after PRAC, the patients received radical operation and 6 chemotherapeutic courses with FCF regimen. Concurrent patients receiving surgical treatment yet no PRAC therapy were chosen as controls. RESULTS: One-year survival rate was 93.05% in the PRAC group and 80.78% in the controls (P = 0.023). COX multivariate analysis was used to analyse the prognostic factors. Dukes'staging and the PRAC prescription or not were found to be independent prognostic factors of colorectal cancer patients. Patients in the PRAC group survived longer than those in the control group. CONCLUSION: PRAC can improve the survival of colorectal cancer patients.

Antineoplastic Agents↗