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Biomedical subjects

C Sun

Publications and source records attributed to C Sun.

At least 145 records · Page 8Linked to original sources
PubMed1997

Thymic carcinoma (report of 14 cases).

This paper reports of 14 cases of thymic carcinoma. Most of them with symptoms of chest pain, chest stuffy and discomfort, but without combined with extrathoracic syndromes. The tumors always were large in size and frequently invaded adjacent organs, hence with low resection rate. In this series, complete resection of tumor only 2 cases, partial resection in 7 cases, exploratory thoracotomy in 5 cases. Thymic carcinoma was an extremely malignant tumor with extensive invasion intrathoracally and early metastasis extrathoracally. The common sites of metastasis were bone, liver, lung and extrathoracic lymph nodes. Adjuvant therapy postoperatively was given to all patients. Follow-up of 1-8 years showed 10 cases death, of which 5 cases died within the first year after surgery, 3 cases within the second year. Four patients were still alive so far, in which 3 patients were within 1.5 years postoperatively. Pathological studies revealed 9 cases of squamous epithelial cell thymic carcinoma, 3 of lymphoepithelioma-like thymic carcinoma and 2 of small cell undifferentiate thymic carcinoma.

Adult↗
PubMed1997

[Capillary gas chromatographic analysis of micro impurities in acrylonitrile].

A megabore SCOT series column of silicone OV-101 and OV-17 for the analysis of micro amount of impurities in acrylonitrile is presented. By using the columns of 50m x 0.53mm i.d. OV-101 and 25m x 0. 53mm i.d. OV-17, with column temperature of 75 degrees C and N2 as carrier gas, u=8cm/s, the main impurities, such as acrolein, acetone and acetonitrile may be well separated from acrylonitrile in 26 min. The results indicate that the series column possesses of high separation efficiency and long column life. The error in quantitative analysis was less than 4%.

English Abstract↗
PubMed1997

The effect of moderately increased CO2 concentration on perception of coherent motion.

BACKGROUND: Several studies have shown that some aspects of vision are impaired when exposed to higher than normal CO2 concentrations in air. The effect of moderately increased CO2 concentration on coherent motion perception, however, has not been studied. HYPOTHESIS: Studies in neurophysiology and cell biology have provided evidence that higher than normal CO2 concentration in air affects cell activities from the retina to the cortex, including the V1 area in the visual cortex. We predicted that motion perception may be impaired by moderately increased CO2, since the V1 area is a gateway for visual motion information processing. The purpose of the present work was to investigate the effect of 2.5% CO2 concentration in air on coherent motion perception. METHODS: Random dot cinematograms were generated by a computer and served as visual stimuli. A whole-room indirect calorimeter was used for the accurate measurement and control of CO2 concentration in air, and served as the experimental environment. A two-interval-forced choice (2IFC) psychophysical procedure was employed to obtain psychometric functions. RESULTS: For all three subjects, psychometric functions were shifted to the right when exposed to 2.5% CO2 in breathing air, compared to those using fresh air. CONCLUSION: This finding implies that human ability in detecting coherent motion can be temporally impaired when CO2 concentration in air is raised to 2.5%.

Aerospace Medicine↗
PubMed1997

Oxygen free radical injury and its relation to bacterial and endotoxin translocation after delayed fluid resuscitation: clinical and experimental study.

OBJECTIVE: To examine whether there is generation of oxygen free radicals (OFR) and lipid peroxidation of cell membrane after volume replacement for burn shock, and to study the relationship between OFR injury and enterogenous endotoxemia. METHODS: Forty-seven burn patients were involved in this study. Among them, 18 had delayed fluid resuscitation (DR) and the others had early fluid resuscitation (ER) within 6 hours postburn. Sixty-six gnotobiotic rats were used in a collaborating experiment as burn models. They were divided into 4 groups: sham injury (n = 6), early resuscitation (n = 24), late resuscitation (n = 24) and vitamins E and C treatment group (n = 12). All the rats, except those in the sham injury group, were inflicted with 40% total body surface area (TBSA) third-degree burns. OFR was determined in the blood of patients with electron spin resonance (ESR). S/W ratio and tau c values of patients' erythrocytes were measured with ESR spectrometer. Blood superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) activities, malondialdehyde contents and plasma endotoxin levels were assayed. Rats were sacrificed at the 12th, 24th, 48th and 72nd hour after injury. Plasma endotoxin levels, mucosal SOD, GSHPx and malondialdehyde (MDA), as well as diamine oxidase activity of ileum were determined. Cultures of mesenteric lymph nodes (MLN), liver, spleen, heart, lung, kidney and blood were done. RESULTS: A significant increase in blood OFR contents and plasma MDA, and a significant decline in blood SOD and GSHPx were found after resuscitation in DR group as compared with those in ER group. Both strong to weak spectra component (S/W) ratio and tau c value were higher in DR group in contrast with those in ER group. Higher elevation in plasma endotoxin level in DR group was seen. In DR group, plasma MDA content was correlated with S/W ratio, tau c value and plasma endotoxin level. In rats, the level of mucosal MDA, plasma endotoxin and incidence of bacterial translocation (BT) were significantly higher. Mucosal SOD, GSHPx and diamine oxidase (DAO) activity were significantly lower in DR group as compared with those in ER group. In DR group, mucosal MDA content was negatively correlated with mucosal DAO activity, while the latter was negatively correlated with BT. After treatment with vitamins E and C, mucosal MDA content decreased, plasma endotoxin and BT significantly declined and mucosal DAO heightened. CONCLUSIONS: Tissue reperfusion might induce the production of OFR, resulting in lipid peroxidation injury, especially to intestinal mucosa, and resulting in disruption of mucosal barrier function followed by endotoxemia and BT.

Adolescent↗
PubMed1997

[Clinical evaluation on laparoscopic diagnosis of pelvic endometriosis by heat-colour test with endocoagulation].

OBJECTIVE: To assess the value of heat-colour test (HCT) with endocoagulation under laparoscopy as a new method for diagnosis of pelvic endometriosis (EM). METHODS: Laparoscopic visible examination (LVE), lesion biopsy and HCT with endocoagulation were employed for diagnosis of EM in 83 cases of infertility. Brown-black colour changes of peritoneal tissue after endocoagulation with controlled heating (100 C) indicate EM implants (HCT positive). RESULTS: LVE indicated that 35 cases had peritoneal lesions typical of EM in appearance. HCT was positive in all cases of visible EM lesions. 48 cases showed no visible peritoneal lesions by LVE, but nonpigmented peritoneal EM lesions were detected by HCT in 20 of the 48 cases. A variety of gross appearances of nonpigmented EM lesions were found in our study including: peritoneal hyperemia (70.9%), circular peritoneal defects (12.7%), semitransparant glandular excrescences (10.9%), white opacification of the peritoneum (10.9%) and normal appearance (5.4%). 25 biopsies were taken from nonpigmented peritoneal lesions in 13 cases. Histology examinations revealed the presence of EM in 64.0% of them. CONCLUSIONS: HCT is a reliable, sensitive and accurate method for diagnosis of EM. It can overcome multiple factors for missing diagnosis of EM by LVE and biopsy. The clinical significance of HCT is its ability to detect nonpigmented endometriotic lesions, to differentiate the causes of pelvic adhesions, therefore to increase accuracy of FIGO EM staging under laparoscopy.

Endometriosis↗
PubMed1997

[The mediopatellar plica syndrome of knee in 61 cases].

From 1989 to 1996, 61 patients, including 66 knees, aged 8 to 62, were diagnosed as mediopatellar plica syndrome of knee after arthroscopic examination. Twenty-one cases were misdiagnosed as medial meniscal lesions before arthroscopic examination. Fifty-nine patients (64 knees) underwent arthroscopic resection of the plicae and 2 patients underwent opened resection. Fifty-nine cases had an average follow-up of seven months. Fifty cases (54 knees) of them showed excellent and good results.

Adolescent↗
PubMed1996

Serologic association between human papillomavirus type 16 infection and esophageal cancer in Shaanxi Province, China.

BACKGROUND: The existence of large geographic variations in the prevalence of esophageal cancer in some countries, such as China, indicates that environmental risk factors may be important in the development of this disease. Some studies have implicated genital-mucosal strains of human papillomaviruses (HPVs) in the etiology of this cancer. PURPOSE: We conducted a case-control study in Shaanxi Province, China, an area with a population at high risk for esophageal cancer, to assess the association of this disease with infection by HPV type 16 (HPV16), the most common cancer-associated genital-mucosal HPV type. METHODS: Ninety individuals with esophageal cancer and 121 cancer-free control subjects were identified among the patients in two hospitals in Xi'an, Shaanxi Province. The control subjects were matched to the case patients on the basis of age and sex. Blood specimens were drawn from all study subjects, and serum was isolated by routine methods. The presence of HPV16 antibodies in serum samples was determined by use of an enzyme-linked immunosorbent assay (ELISA) that used baculovirus-derived HPV16 virus-like particles as the antigen. A similar ELISA that used bovine papillomavirus type 1 (BPV1) virus-like particles as the antigen controlled for the specificity of HPV16 seroreactivity. Data from the HPV16 and the BPV1 assays were normalized with respect to results obtained in each assay with a control serum of known HPV16 seroreactivity. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to examine the association between HPV16 seroreactivity and esophageal cancer. Reported P values are two-sided. RESULTS: The mean seroreactivity to HPV16 virus-like particles was significantly higher for the cancer patients than for the control subjects (mean value +/- standard deviation = 0.85 +/- 0.22 versus 0.74 +/- 0.18; P<.0001). When the cancer patients and control subjects were compared by sex and age groups, the differences in mean seroreactivity remained statistically significant. The difference in mean seroreactivity to BPV1 virus-like particles between cancer patients and control subjects was not statistically significant (0.81 +/- 0.28 versus 0.88 +/- 0.32; P = .12); this result was not altered when sex and age groups were compared. By use of a cutoff point for HPV16 seropositivity that was established in studies of cervical neoplasia, 24% of the cancer patients were seropositive compared with 7% of the control subjects, yielding a sex- and age-adjusted OR of 4.5 (95% CI = 1.8-11.9). In general, the OR for esophageal cancer increased with increasing HPV16 seroreactivity. CONCLUSIONS AND IMPLICATIONS: HPV16 infection may be a risk factor for esophageal cancer. Further studies of the association between HPV16 infection and the incidence of esophageal cancer are needed.

Antibodies, Viral↗
PubMed1996

Reversion of UVC-induced tumorigenic human hybrid cells to the non-tumorigenic phenotype.

Non-tumorigenic HeLa x skin fibroblast human hybrid cells were UVC-irradiated (10 J/m2) and induced to neoplastic transformation with accompanying morphological change and expression of the HeLa tumour-associated antigen, intestinal alkaline phosphatase (IAP). A single-cell-derived cell line was cloned out of a neoplastically transformed focus and designated as UV-12. In low density culture, this cell line demonstrated the ability to undergo reversion to a morphology similar to that of the non-tumorigenic parent with accompanying, much reduced levels of IAP expression. The frequency of this reversion to low IAP expression increased with passage of low density cultures reaching 10(-2) at 26 passages. A revertant colony was selected and expanded into a cell line which was designated UV-12-RM-1. This cell line had a 67-fold reduction in IAP expression compared to UV-12 and demonstrated a much reduced tumorigenic phenotype. A cell line reconstituted from a tumour derived from this cell line demonstrated a high IAP expression level (3-fold less than UV-12) and was highly tumorigenic. Six single-cell-derived lines were cloned from UV-12-RM-1 and all had low IAP expression. Of these, one demonstrated an aggressive tumorigenicity, four showed the reduced tumorigenic phenotype characteristic of UV-12-RM-1, and one (UV-12-RM-105) was non-tumorigenic. However, with passage in culture, this latter cell line reverted to a weakly tumorigenic phenotype and a much elevated IAP level. It is hypothesised that the phenotypic shifts demonstrated by these UV-induced tumorigenic cells are under epigenetic control, and that they are most likely a consequence of an underlying genetic instability in the survivors of UVC-irradiation.

Alkaline Phosphatase↗
PubMed1996

Effect of low-concentration CO2 on stereoacuity and energy expenditure.

BACKGROUND: Low-concentration CO2 commonly exists in our living environment in such locations as airplanes and cars. Its effect on visual performance and energy metabolism (through O2 uptake) has not been well studied, although several studies have shown that high-level CO2 (6-10%) significantly impaired visual performance. HYPOTHESIS: We felt that breathing CO2 might also interfere with the energy expenditure pathway, partly due to the reduced O2 fraction. Thus, we studied the effect of low-concentration CO2 (2.5%) on human visual stereoacuity and energy expenditure. METHODS: Computer-controlled Random Dot Stereograms and psychometric function were used for stereoacuity tests. A whole-room indirect calorimeter allowed for the accurate measurement of energy expenditure, and also served as a good testing environment. RESULTS: Of 10 subjects tested, 8 had a slight increase in resting energy expenditure after exposure to 2.5% CO2. The increase ranged from 0.4-6.1% (p = 0.087, paired t-test). In stereoacuity tests, the psychometric function curves of all three subjects tested shifted to the right when breathing 2.5% CO2 and returned to baseline 2 h after breathing fresh air. Stereoacuity value, which is the reciprocal of stereoscopic threshold, was significantly lower (p < 0.01, 2-tailed z score test) after CO2 exposure for all subjects tested. CONCLUSION: We conclude that CO2 levels as low as 2.5% can cause temporary reduction in human stereoacuity, and also cause a persistent but small increase in energy expenditure.

Adult↗
PubMed1996

[Overexpression of P53 and its risk factors in esophageal cancer in urban areas of Xian].

OBJECTIVE: To investigate the risk factors of esophageal cancer (EC) in urban areas of Xi'an, and to correlate these risk factors with overexpression of P53 in EC. METHODS: A hospital-based case-control study was performed. All cases (89) and controls (97) were permanent residents in urban areas of Xi'an. Tumor tissues and normal tissues adjacent to tumors of 65 cases, and 24 available normal esophageal tissues of controls were detected by P53 overexpression via immunohistochemical method. RESULTS: Smoking and family history of EC were significantly associated with EC in Xi'an inhabitants. OR was 3.26 and 10.48, respectively. The laboratory findings indicated that P53 positive stain in Ec was 52.3% (34/65) and 6.1% (4/65) in normal tissues adjacent to tumor, but no positive stain was found in normal esophageal tissues of controls. Moreover, the results showed that P53 overexpression was closely related to smoking and family history of EC. OR was 3.89 and 17.28, respectively. CONCLUSION: These findings suggest that smoking and family history of EC are important risk factors for EC, and the alteration of P53 gene may be related to smoking and inherited factor.

Aged↗
PubMed1996

Surgical treatment and prognosis of bronchial carcinoid tumor.

In order to understand the effect of surgery in the treatment of the bronchial carcinoid tumor and the factors affecting prognosis, 18 cases of bronchial carcinoid tumor are presented, including 5 cases with Cushing's syndrome. There were lobectomy in 10, lung wedge resection in 3, excision of intraluminal tumor of bronchus in 3, exploratory thoracotomy in 2 cases. No operation death. Pathological examination revealed 14 cases were typical carcinoid tumor and 4 cases were atypical carcinoid tumor. By 2-13 years follow-up, 3, 5 and 10 years survival rate were 82%, 78% and 70% respectively. Bronchial carcinoid tumor is often confused with small cell carcinoma of lung, the correct diagnosis can be obtained by light microscopic, electron microscopic and immunohistochemistry studies. Those patients accompanied with ectopic-ACTH secretion always have Cushing's syndrome, resection of tumor can produce good result. Proper operation method depends on the location of the tumor and patient's extent of cardiac and pulmonary reserve. Atypical carcinoid tumor had high malignancy and poor prognosis. The size of tumor, lymph node involvement and adjuvant therapy seem no definite effect on the patients' survival rate.

Adolescent↗
PubMed1996

[Protective effects of radix Salviae miltiorrhizae on azathioprine hepatotoxicity in rats].

The changes of liver function and malondialdehyde (MDA) and glutathione (GSH) were studied in rats intoxicated with azathioprine (Aza) 15mg/(kg.d) and in rats treated with Aza mixed Salviae 8g/(kg.d). The results showed that in the Aza group, the levels of ALT, AKP, MDA increased and GSH decreased significantly in week 1 and week 2. But in the Salviae group the levels of ALT, AKP, MDA decreased and GSH increased significantly, approaching the normal levels, It follows that Salviae has protective effects on Aza hepatotoxicity in rats.

Animals↗
PubMed1995

Induction of cisplatinum sensitivity without alteration in radiation sensitivity by fractionated radiation treatment of a human laryngeal squamous cell carcinoma cell line.

PURPOSE: To determine if fractionated radiation treatment can alter cisplatinum sensitivity of a human laryngeal squamous carcinoma cell line. METHODS AND MATERIALS: Human squamous carcinoma cells, both previously untreated, as well as survivors of fractionated radiation therapy, were tested in vitro for their sensitivity to gamma radiation and cisplatinum. Fractionated gamma radiation was delivered in 14 or 10 daily fractions of 2 Gy. The cell line, cSCC-20, was derived from an untreated primary human laryngeal carcinoma. RESULTS: The human laryngeal squamous cell carcinoma cell line, cSCC-20, was demonstrated to have heterogeneous subpopulations with respect to cisplatinum sensitivity. No variation in radiation sensitivity was seen among subpopulations of varying cisplatinum sensitivity. The cells were relatively radioresistant (Do = 2.5 Gy). Fractionated radiation treatments of the parent cell line (14 fractions, 14 days, 2 Gy/fraction) or a cisplatinum sensitive subline (10 fractions, 12 days, 2 Gy/fraction) induced cisplatinum sensitivity (factor of 1.3 to 1.4) in the surviving cells. CONCLUSION: Fractionated radiation treatment of human squamous carcinoma cells in vitro induced sensitivity to cisplatinum without concomitant alteration in radiation sensitivity.

Carcinoma, Squamous Cell↗