Biomedical subjects

Z Sun

Publications and source records attributed to Z Sun.

At least 235 records · Page 13Linked to original sources

PubMed1996

[The internalization of immunotargeting drugs for hepatocellar carcinoma and its significance].

OBJECTIVE: To study the internalization law of immunotargeting drug for hepatocellular carcinoma and its significance. METHODS: Colloidal gold technique and the process of internalization of the immunotargeting drugs, Hab18-ADM and Hab25-ADM, against hepatoma in the targeting cells of human hepatoma cell line SMMC-7721 was used under an electron microscope. RESULTS: 80% of the target cells with gold-labeled particles on the cellular surfaces. The main way of internalization was invariably through a non-coated microinvagination. 18 hours after the intercellular internalization of immunotargeting drugs, the cytoplasmic vacuolization could be visible, even cellular necrosis. The control cells grew well. The above results indicate that after entering into the targeting cells the immunotargeting drugs degrade within the lysosomes, then, ADM arrives at its function site and plays the role of cell toxicity intranuclearly. CONCLUSION: The internalization of Hab 18-ADM and Hab25-ADM is effective, and possesses a good prospect in clinical application.

Antibiotics, Antineoplastic↗

PubMed1996

[Study on factors influencing survival in patients with advanced gastric carcinoma after resection by Cox's proportional hazard model].

A prospective follow-up study of 539 advanced gastric carcinoma patients after resection was undertaken between 1 January 1980 and 31 December 1989, with a follow-up rate of 95.36%. A multivariate analysis of possible factors influencing survival of these patients was performed, and their predicting models of survival rates was established by Cox proportional hazard model. The results showed that the major significant prognostic factors influencing survival of these patients were rate and station of lymph node metastases, type of operation, hepatic metastases, size of tumor, age and location of tumor. The most important factor was the rate of lymph node metastases. According to their regression coefficients, the predicting value (PV) of each patient was calculated, then all patients were divided into five risk groups according to PV, their predicting models of survival rates after resection were established in groups. The goodness-fit of estimated predicting models of survival rates were checked by fitting curve and residual plot, and the estimated models tallied with the actual situation. The results suggest that the patients with advanced gastric cancer after resection without lymph node metastases and hepatic metastases had a better prognosis, and their survival probability may be predicted according to the predicting model of survival rates.

Female↗

PubMed1996

[Effect of anisodamine in prevention and treatment of visceral complications in serious burns].

From January 1992 to December 1994, anisodamine was used in 156 cases of serious burns. The results showed that there was a significant lowering of incidence of visceral complications in the treatment group than in the control group. Also the cure rate of visceral complications was significantly elevated in the treatment group than control group. The result indicated that anisodamine had both prevention and treatment effects on visceral complications in serious burns.

Adult↗

PubMed1996

[Treatment of oral leukoplakia with retinamide].

Inhibition of buccal pouch carcinogenesis induced by dimethyl-benzanthracene in hamsters with retinamide was studied. Group A received oral retinamide at a dosage of 20mg/kg, every day for eight weeks. Group B was treated by retinamide orally at the same dosage, plus topical treatment by retinamide. Group C was treated by retinamide topically for eight weeks. Experiments exhibited that under the action of retinamide the incidence of tumor was lowered significantly. All the Group A, B and C had a good response. Clinically 80 patients were randomly arranged into two groups. One group received placebo and served as controls and the other group was treated by retinamide. Results indicate that retinamide is effective against leukoplakia and the response rate is as high as 84.0%. By contrast, only 16.7% of patients receiving placebo showed some improvement.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1996

[The nonfunctional adrenal tumors: report of 30 cases].

79 cases of adrenal tumors were treated in our hospital from 1985 to Aprit. 1994. 30 of them had nonfunctional adrenal tumors. Data have shown that nonfunction adrenal tumor is not unusual. The detection rate of the disease will increase with the development and popularization of medical imageology which consists of B-ultrasonography and CT scanning etc. In this article, the diagnosis and treatment of this disease were discussed in detail with a review of the literature.

Adenocarcinoma↗

PubMed1996

[The secondary ossification center of fetus].

Most textbooks on human anatomy and human embryology state that the appearance of the secondary ossification center (SOC) of the fetus is considered to be after or around birth. In our study, while collecting the data on growth indexes from 346 fetuses in normal pregnancy with conceptional ages from 12 to 38 complete weeks, we investigated using B-ultrasonography the appearance of the secondary ossification center and compared them in part with the anatomically observed data collected from fetal specimens. The results of B-ultrasonic observation show that SOC can be seen at the distal end of femur after 29 complete weeks. From them on, the percentage of the appearance of SOC increases weekly, and it is almost 100% in 34 complete weeks.

Female↗

PubMed1996

[Hepatic tuberculosis: a report of 8 patients].

8 patients with hepatic tuberculosis were confirmed by surgical operation and pathological examination of liver. The average age of the patients was 26.5 years. Only one of the 8 patients was suspected of having hepatic tuberculosis before operation. Liver biopsy during the operation was carried out in 3 patients, and lobectomy or partial excision of the liver was performed in 4 patients, and incision and drainage of the liver abscess were performed in 1 patient. All of the patients were cured. The follow-up results showed that hepatic tuberculosis less than or equals to 3 cm in diameter could be cured by regular chemotherapeutics. In this paper, the infectious path, pathological types, differential diagnosis and treatment are discussed, and experience and lessons are summarized.

Adolescent↗

PubMed1996

[A study on the pathogenetic role of the viral structural proteins of hemorrhagic fever with renal syndrome].

In order to clarify the pathogenesis of hemorrhagic fever with renal syndrome (HFRS), we detected HFRS virus structural proteins expressed in perepheral blood mononuclear cells (PBMC) by using immunohistochemical technique. Meanwhile we also determined plasma endothelin (ET), substance P (SP) and some sensitive markers of renal function with radioimmunoassay. The result showed that in HFRS patients, from the day of admission up to the thirteenth day of illness, the antigens of HFRS virus membrane protein (MP) and nucleocapsid (NP) could simultaneously be found in PBMC, though their expressive degree gradually decreased when the condition of the patients became better. Based on the external appearance and nucleus pattern of PBMC we recognized the MP and NP positive cells were mainly monocytes among which only a few presented faint IgM and C3 stain. On admission there was difference in expressive intensity between MP and NP. The MP expressive intensity was in parallel with plasma ET/SP ratio, the general condition and the severity of renal damage. These data suggest that HFRS virus can invade PBMC, replicate in them, and express their structural proteins. MP may be related with the pathogenesis of HFRS virus and the increase of plasma ET/SP ratio may be an important factor aggravating kidney injury.

Adult↗

PubMed1996

[CT study of the ostiomeatal complex in patients with deviated nasal septum].

This study was designed to evaluate the influence of nasal septal deviation on ostiomeatal complex (OMC). From April 1994 to February 1995, 32 patients with deviated nasal septum were investigated by high-resolution CT scan. The results showed that (1) 15 patients (15/32) were found to have ipsilateral or bilateral ostiomeatal complex disease (OMCD). The incidence of OMCD was related to the severity of the septal deviation; (2) measurement of uncinate process angulation and ethmoid infundibulum width in patients with OMCD was of limited value; (3) the relationship between septal deviation and OMC variation needed further study. It has been indicated that for patients with septal deviation coronal CT study is necessary to evaluate the degree of OMCD.

Adult↗

PubMed1996

[Protective effect of active components extracted from radix Astragali on human erythrocyte membrane damages caused by reactive oxygen species].

A study has been made on the protective activities of active components extracted from Radix Astragali by using reactive oxygen species initiated lipid peroxidation of purified human erythrocyte membrane. The results show that the total flavonoids of Astragalus and total saponins of Astragalus can significantly inhibit the membrane lipid peroxidation generated by O2.-, H2O2 and UV rays, while the total polysaccharide of Astragalus possesses weaker protective activity.

Drugs, Chinese Herbal↗

PubMed1995

Organization and analysis of the complete rat calmodulin-dependent protein kinase IV gene.

A 42-kilobase pair region of rat DNA containing the Ca2+/calmodulin-dependent protein kinase IV (CaM kinase IV) gene has been cloned and characterized. The gene consists of 12 exons and 11 introns and is predicted to encode both beta and alpha forms of CaM kinase IV as well as the testis-specific calmodulin-binding protein calspermin. The promoter utilized to generate the alpha-kinase isoform is located in intron 1, whereas the promoter utilized to produce the calspermin transcript is contained in intron 10. The calspermin promoter region which extends from -200 to +321 relative to the calspermin transcription initiation site that contains two cyclic AMP response elements (CRE) at -70 and -50 and has been shown previously to be inactive in NIH3T3 cells (Sun, Z., Sassone-Corsi, P., and Means, A. R. (1995) Mol. Cell. Biol. 15, 561-571) was ligated to the lacZ reporter gene and used to generate transgenic mice. The promoter was expressed exclusively in postmeiotic testis where beta-galactosidase was found predominantly in elongating spermatids. The cell and developmental specificity of transgene expression was very similar to the pattern shown by the endogenous gene. Although the transgene promoter was silent in somatic tissues, beta-galactosidase expression could be restored in primary cultures of skin fibroblasts by introduction of vectors encoding CREM tau and CaM kinase IV.

Amino Acid Sequence↗

PubMed1995

Results of revascularization in patients with severe left ventricular dysfunction.

BACKGROUND: In patients with coronary artery disease and poor ventricular function (ejection fraction, < 20%), bypass grafting remains a surgical challenge. This study evaluates experience with isolated revascularization in such patients. METHODS AND RESULTS: In 79 consecutive patients (69 men, 10 women; average age, 59 +/- 9 years), preoperative ejection fraction was 18 +/- 5%. Indications for surgery were congestive heart failure (CHF) in 5 of 79 patients (6%), CHF and angina in 19 (24%), angina in 41 (52%), ventricular arrhythmias (VAs) in 8 (10%), and critical anatomy in 6 (8%). Some patients had prior VAs (23 of 79; 29%) or mitral regurgitation (18; 23%) and required emergent surgery (25; 32%). At surgery, temperature mapping ensured adequate distribution of antegrade cold cardioplegia, with 3.6 +/- 0.7 grafts per patient, including left internal mammary artery graft in 60 of 79 (76%) and endarterectomy in 14 (18%). Hospital mortality was 3.8%. Perioperative support included intra-aortic balloon pump in 18 of 79 (23%) and drugs for VAs in 28 (35%). Morbidity included myocardial infarction in 2 of 79 (2.5%) and stroke in 2 (2.5%). During follow-up, there were 19 late deaths. Actuarial survival was 94%, 82%, and 68% at 1, 2, and 5 years, respectively, and was similar in patients with severe angina, CHF, mitral regurgitation, or VAs. Freedom from sudden death was 100%, 98%, and 91% at 1, 2, and 5 years, respectively. Among survivors, angina improved in 84% and heart failure improved in 26%. CONCLUSIONS: These data support bypass graft surgery in patients with severe LV dysfunction. With careful cardioplegic techniques, hospital mortality was low (3.8%). Long-term survival is encouraging, with good relief of symptoms in most patients. Perioperative VAs are frequent but respond to medical treatment, with only 23% of patients discharged on antiarrhythmic drugs. Five-year freedom from sudden death is 91%, with only 3 late sudden deaths in this series.

Actuarial Analysis↗

PubMed1995

Is sex a factor in determining operative risk for aortocoronary bypass graft surgery?

BACKGROUND: This study examines trends and sex differences in characteristics of patients referred for bypass graft surgery to identify factors associated with operative morbidity and mortality. METHODS AND RESULTS: Data were collected prospectively on consecutive patients (1132 men and 355 women). Over time, the proportion of patients > 65 years old, with diabetes, or requiring urgent surgery, increased. Predictors of mortality were age > 75 years, urgent surgery, and poor left ventricular (LV) grade. Women were older (62 +/- 9 versus 59 +/- 9 years, P < .001) and had more varicose veins (18% versus 7%, P < .001), diabetes (27% versus 18%, P < .001), hypertension (48% versus 41%, P < .05), peripheral vascular disease (16% versus 12%, P < .05), and more severe angina (P < .001). There were no sex differences in prior myocardial infarction (59% versus 62%) or need for urgent surgery (17% versus 18%). Women had a higher ejection fraction (51% +/- 12% versus 47% +/- 14%, P < .001) and fewer diseased vessels (2.4 +/- 0.7 versus 2.6 +/- 0.6, P < .001) and received fewer grafts (2.9 +/- 0.9 versus 3.3 +/- 0.8, P < .001). Women had smaller body size but were no more likely to have small target vessels (< 1.5 mm). There was no sex difference in operative mortality (1.4% versus 1.1%), perioperative myocardial infarction (4.8% versus 3.5%), need for intra-aortic balloon pump (10% versus 8%), stroke (1.7% versus 1.4%), reexploration for bleeding (1.7% versus 1.7%), or leg infection (2.0% versus 1.4%). Women had fewer sternal wound infections (0.6% versus 2.2%, P < .05). CONCLUSIONS: Predictors of mortality include advanced age, decreased LV function, and need for urgent surgery. With time, despite increasing age, associated diabetes, and increased urgent surgery, operative mortality has decreased. Women were older and had more diabetes and hypertension but less extensive disease and better LV function. Bypass graft surgery was associated with equally low mortality in women and men (1.4% versus 1.1%). Concern over increased operative mortality in women should not bias referral patterns for angiography and coronary bypass graft surgery.

Aged↗

PubMed1995

An intron facilitates activation of the calspermin gene by the testis-specific transcription factor CREM tau.

Calspermin is a high affinity Ca2+/calmodulin binding protein that is found only in postmeiotic male germ cells. Our previous studies have shown that the calspermin transcript is produced by utilization of a testis-specific promoter located within an intron of the calmodulin kinase IV gene. This promoter contains two cAMP response element-like motifs that bind the testis-specific transcription factor CREM tau. This interaction is required for transcriptional activation. Here we describe a novel regulatory element, the 111-base pair first intron of the calspermin gene, which is also required for enhancement of transcription by CREM tau via the cAMP response element motifs. Deletion or inversion of this intron results in loss of CREM tau-mediated stimulation of transcription. However, CREM tau stimulates calspermin promoter activity when the intron is moved upstream of the promoter but only when inserted in the proper orientation. Footprint, linker scanning, and deletion analyses were used to identify regulatory elements in the intron. We suggest that the intron functions as an orientation-dependent but position-independent regulatory element to activate the calspermin promoter by facilitating the stimulatory effect of CREM tau on transcription.

3T3 Cells↗

PubMed1995

Aberrant cell cycle inhibition pattern in human colon carcinoma cell lines after exposure to 5-fluorouracil.

In this report, we describe the use of two human colon carcinoma cell lines, HCT-8 and HT-29, as potential models to study DNA- and RNA-directed cytotoxicity due to 5-fluorouracil (FUra) exposure by flow microfluorimetric analysis of DNA cell content. The sensitivity of the HT-29 line (EC50 = 0.9 microM) to FUra was somewhat greater than that of the HCT-8 line (EC50 = 4 microM), but each presented a dramatically different DNA histogram after exposure to FUra. In HCT-8, an unexpected and nearly complete disappearance of cells in S-phase occurred, whereas in HT-29 the expected accumulation of cells at the G1-S border was observed. The absence of HCT-8 cells in S-phase also occurred as a result of two RNA polymerase inhibitors: actinomycin D and dichloro-D-ribofuranosylbenzimidazole. However, an accumulation of cells in S-phase was observed in the presence of 5-fluorodeoxyuridine. These results suggest that in the HCT-8 cell line, FUra predominantly causes an RNA-related toxicity. By comparison, the rate of formation of 5-fluorodeoxyuridine monophosphate, the increased dUMP pool size, and low thymidylate synthase activity in the HT-29 line are consistent with its greater susceptibility to DNA-directed toxicity. Further evidence was seen in the prevention of FUra cytotoxicity by thymidine in HT-29, but not in HCT-8 cells. Similarly, Leucovorin synergized the action of FUra in HT-29 but not in HCT-8. Enzymatic correlates supporting these observations are seen in the greater activity of uridine kinase than thymidine kinase (20:1) in HCT-8 cells compared with that in HT-29 cells (4:1).

Cell Cycle↗

PubMed1995

Identification and characterization of a functional promoter region in the human eosinophil IL-5 receptor alpha subunit gene.

The molecular basis for the commitment of multipotential myeloid progenitors to the eosinophil lineage, and the transcriptional mechanisms by which eosinophil-specific genes are subsequently expressed and regulated during eosinophil development are currently unknown. Interleukin-5 (IL-5) is a T cell and mast cell-derived cytokine with actions restricted to the eosinophil and closely related basophil lineages in humans. The high affinity receptor for IL-5 (IL-5R) is composed of an alpha subunit (IL-5R alpha) expressed by the eosinophil lineage, that associates with a beta c subunit shared with the receptors for IL-3 and granulocyte-macrophage colony stimulating factor (GM-CSF). As a prerequisite to studies of the transcriptional regulation of the IL-5R alpha subunit gene, we used three different methods, including primer extension, RNase protection, and 5'-RACE to precisely map the transcriptional start site to a position 15 base pairs (bp) upstream of the 5' end of the published sequence of IL-5R alpha exon 1. To initially identify the IL-5R alpha promoter, 3.5 kilobases (kb) and 561 bp of the 5' sequence flanking the transcriptional start site were subcloned into the promoterless pXP2-luciferase vector. Transient transfection of these constructs into an eosinophil-committed HL-60 subline, clone HL-60-C15, induced the expression of approximately 240-fold greater luciferase activity than the promoterless vector, identifying a strong functionally active promoter region within the 561 bp of sequence proximal to the transcriptional start site and with activity equivalent to pXP2 constructs containing the entire 3.5 kb of upstream sequence. To more precisely localize the cis-acting regulatory elements in this region important for promoter activity, a series of 5' deletion mutants of the 561-bp region were generated in the pXP2-luciferase vector. Deletion of the region between bp -432 and -398 reduced promoter activity by more than 80% in the HL-60-C15 cell line. Further analyses of the activity of the IL-5R alpha promoter constructs in various other eosinophil, myeloid, and non-myeloid cell lines indicated that the promoter was relatively myeloid and eosinophil lineage-specific in its expression. Consensus sequences for known transcription factor binding sites were not present in the 34-bp region of the promoter required for maximal activity, suggesting unique myeloid- and possibly eosinophil-specific regulatory elements.(ABSTRACT TRUNCATED AT 400 WORDS)

Base Sequence↗

PubMed1995

The Hancock II bioprosthesis at ten years.

The Hancock II bioprosthesis was used for heart valve replacement in 843 patients from 1982 to 1993. Aortic valve replacement (AVR) was performed in 536 patients, mitral valve replacement (MVR) in 250, and aortic and mitral valve replacement (DVR) in 57. The mean age was 64 +/- 12 years. Before operation, 80% of the patients were in New York Heart Association functional class III or IV; approximately one-third of the patients had coronary artery disease, and 60 patients had ascending aorta aneurysm. There were 47 operative deaths (AVR, 4%; MVR, 7%; DVR, 10%) and 147 late deaths. Follow-up was complete in 98.6% of the patients and extended from 3 to 140 months (mean, 59 months). At the last follow-up, 84% of the patients were in New York Heart Association class I or II. The actuarial survival at 10 years was 63% +/- 4% for AVR, 55% +/- 5% for MVR, and 53% +/- 9% for DVR. At the end of 10 years, the freedom from thromboembolic complications was 80% +/- 4% for AVR, 88% +/- 3% for MVR, and 86% +/- 5% for DVR; the freedom from endocarditis was 95% +/- 2% for AVR, 96% +/- 1% for MVR, and 87% +/- 5% for DVR; the freedom from primary tissue failure was 92% +/- 3% for AVR, 81% +/- 6% for MVR, and 65% +/- 16% for DVR; and the freedom from reoperation was 89% +/- 2% for AVR, 81% +/- 6% for MVR, and 61% +/- 15% for DVR. The durability of this bioprosthetic valve was affected by the patient's age and by the position where it was implanted. The clinical results of the Hancock II bioprosthesis at 10 years are comparable to those of other current porcine and pericardial valves.

Actuarial Analysis↗

PubMed1995

Cell shape, cytoskeletal mechanics, and cell cycle control in angiogenesis.

Capillary endothelial cells can be switched between growth and differentiation by altering cell-extracellular matrix interactions and thereby, modulating cell shape. Studies were carried out to determine when cell shape exerts its growth-regulatory influence during cell cycle progression and to explore the role of cytoskeletal structure and mechanics in this control mechanism. When G0-synchronized cells were cultured in basic fibroblast growth factor (FGF)-containing defined medium on dishes coated with increasing densities of fibronectin or a synthetic integrin ligand (RGD-containing peptide), cell spreading, nuclear extension, and DNA synthesis all increased in parallel. To determine the minimum time cells must be adherent and spread on extracellular matrix (ECM) to gain entry into S phase, cells were removed with trypsin or induced to retract using cytochalasin D at different times after plating. Both approaches revealed that cells must remain extended for approximately 12-15 h and hence, most of G1, in order to enter S phase. After this restriction point was passed, normally 'anchorage-dependent' endothelial cells turned on DNA synthesis even when round and in suspension. The importance of actin-containing microfilaments in shape-dependent growth control was confirmed by culturing cells in the presence of cytochalasin D (25-1000 ng ml-1): dose-dependent inhibition of cell spreading, nuclear extension, and DNA synthesis resulted. In contrast, induction of microtubule disassembly using nocodazole had little effect on cell or nuclear spreading and only partially inhibited DNA synthesis. Interestingly, combination of nocodazole with a suboptimal dose of cytochalasin D (100 ng ml-1) resulted in potent inhibition of both spreading and growth, suggesting that microtubules are redundant structural elements which can provide critical load-bearing functions when microfilaments are partially compromised. Similar synergism between nocodazole and cytochalasin D was observed when cytoskeletal stiffness was measured directly in living cells using magnetic twisting cytometry. These results emphasize the importance of matrix-dependent changes in cell and nuclear shape as well as higher order structural interactions between different cytoskeletal filament systems for control of capillary cell growth during angiogenesis.

Actin Cytoskeleton↗