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Biomedical subjects

L Zhu

Publications and source records attributed to L Zhu.

At least 235 records · Page 13Linked to original sources
PubMed1999

[CT findings of metastatic and primary neoplasms of the kidney: a comparative study].

OBJECTIVE: To study CT findings of renal metastases and compare them with primary renal cell carcinoma. METHODS: CT features of eleven cases of renal metastases and one hundred cases of primary renal cell carcinoma confirmed by histopathology were studied and compared. The metastastic tumors arised from lung carcinoma in 6 cases, esophagus carcinoma in 2 cases and one in each of adrenal cortical carcinoma, testis seminoma and unknown primary tumor. RESULTS: Renal metastases accounted for 3.7% of all malignant tumors of the kidney. The ratio of renal metastases to second primary renal carcinoma was 1:1. On CT, the renal metastases appeared as diffusely invasive, ill-definded mass (63.6%), 18.2% of the neoplasms were multiple, without or less exophytic (81.8%) and without or with minimal enhancing on postcontrast scan (100%). The tumor invaded the pelvocalyceal system (72.7%). In contrast, the primary renal cell carcinomas were nodular, rounded or lobulated and more exophytic mass with well-defined border and regular contours (87.0%). Moderate to high enhancing postcontrast (80.7%) was observed with obvious necrosis (60.2%), foci of calcification (15.0%) and invasion of the renal vein and inferior vena cava (7.0%). CONCLUSION: Contrast-enhanced CT is helpful in the differential diagnosis of renal metastases from primary renal cell carcinoma. But for those showing single, more exophytic mass with well-defined border and intense enhancing postcontrast, the correct diagnosis depends on histopathology.

Adult↗
PubMed1999

[Study on prevention and treatment of middle and aged women diabetes with kidney deficiency and bone metabolic disturbance].

OBJECTIVE: To Study the therapeutic effect of Chinese herbal medicine (CHM) for supplementing Qi, activating blood circulation and tonifying Kidney on prevention and treatment of middle and aged women diabetes with Kidney Deficiency and bone metabolic disturbance. METHODS: Clinical observation was taken in 52 patients, who were divided into two groups, the control group (treated with hypoglycemic agent alone) and the treated group (treated with hypoglycemic agent and CHM). RESULTS: Before treatment, patients of both groups showed obvious higher blood alkaline phosphatase, beta 2-microglobulin (beta 2-MG) level, urinary beta 2-MG, calcium and phosphorus level, but lower serum estradiol level than those in normal subjects. After 3 months' treatment, no apparent change on serum estradiol level was observed, but other parameters were all lowered obviously in the two groups, the changes revealed more obvious in the treated group. The symptoms of Kidney Deficiency, such as lumbodorsal pain, general fatigue, palpitation and vertigo, were improved after treatment, and the improvement was also more obvious in the treated group. CONCLUSION: CHM for supplementing Qi, activating blood circulation and tonifying Kidney was effective in improving Kidney Deficiency and mineral substance loss of bone in middle and aged women diabetes patients. The CHM and western drugs may acted synergistically.

Aged↗
PubMed1999

[A randomized controlled clinical study of sparfloxacin versus ofloxacin in the treatment of bacterial infections].

OBJECTIVE: To evaluate the efficacy and safety of sparfloxacin in the treatment of bacterial infections. METHODS: A randomized controlled multi-centre clinical trial was conducted. Ofloxacin used as the control drug. A total of 212 patients entered the study, with 106 in the sparfloxacin group and the remaining 106 in the ofloxacin group. Both compounds were given by oral administration. RESULTS: The cure rate of sparfloxacin and ofloxacin was 74.5% and 69.8% respectively and the overall efficacy rate was 91.5% and 88.7% respectively. The bacterial clearance rate was 90.7% in the sparfloxacin group and 90.8% in the ofloxacin group. The adverse drug reaction rate of sparfloxacin and ofloxacin was 9.43% and 8.49% respectively. There was no statistical significant difference between the two groups for the above results. The results of in vitro activity of sparfloxacin as compared with other 5 antibacterial agents showed that sparfloxacin had good activity against many Gram-negative organisms and was similar to those of ofloxacin. The activity against Gram-positive organisms (MIC(90) <or= 0.25 mg/L) was generally higher than that of ofloxacin. CONCLUSION: Sparfloxacin is a highly effective and safe broad-spectrum antibacterial agent for the treatment of bacterial infections. It is also effective in the treatment of infections caused by Gram-positive organisms.

Adolescent↗
PubMed1999

[Surgical treatment of truncus arteriosus in children].

OBJECTIVE: To summarize the surgical results of truncus arteriosus in children. METHODS: Five patients with persistent truncus arteriosus underwent complete repair of truncus arteriosus. Type I was found in 2 patients, type II in 2 and type IV in 1 according to Collett and Edwards. Their ages ranged from 3 to 12 years (mean 6.3 years). The time of pulmonary circulation and evacuation of the pulmonary artery was not significantly prolonged. Complete repair was via a median sternotomy utilizing hypothemia with cardiopulmonary bypass, entailing separation of the pulmonary arteries from the truncus, repair of the resultant defect in the aorta, ventricular septal defect (VSD) closure with a patch in which the interrupted pledget-supported suture was placed in the truncal valve annulus of the superior border of VSD, and restoration of right ventricular outflow tract (RVOT) continuity utilizing extra cardiac conduits, of which autologous pericardial valved dacron conduit was used in 4 patients and homograft conduit in 1. RESULTS: Postoperative mean pulmonary pressure decreased significantly in all patients (P < 0.01) and the pressure gradient across conduit was 7 - 35 mm Hg. Two patients died immediately after the operation, which was not associated with pulmonary vascular lesion. Among 3 survivors, I had low cardiac output and respiratory dysfunction after operation and the others recuperated uneventfully. Survivors were followed up for a period of 114, 96 and 34 months respectively, and were all in NYHA functional class I. One died of occlusion of conduit 8 years after operation. CONCLUSIONS: Children with truncus arteriosus are still indicated for complete correction. Autologous pericardial valved dacron conduit has excellent long-term outcomes. Correcting truncal valve insufficiency, repairing VSD, avoiding large pressure gradient across conduit and shortening CPB time are keys to improve the survival rate of patients and achieve excellent long-term outcome.

Bioprosthesis↗
PubMed1999

[Clinical pathological analysis and immunohistochemical expression of primary cervical adenocarcinoma in 98 cases].

OBJECTIVE: To discuss the pathological classification, immunohistochemical expression characteristics, differential diagnosis and factors affecting prognosis in cervical adenocarcinoma. METHODS: Clinical pathological analysis and immunohistochemical study were performed on all primary cervical adenocarcinoma cases (98 patient) from 1991 to 1998. Comparison was made with 18 cases of endometrial adenocarcinoma. 54 cases were followed-up. RESULTS: These primary cervical adenocarcinoma cases fell into 5 categories, of which the endocervical type being the most common. The positive rate of CEA, HPV16 and HPV6B/11 staining were 15/18 (83.3%), 6/9 (66.7%) and 10/18 (55.6%) cases respectively, while the results of ER and vimentin staining were all negative. PCNA staining was strongly positive in all the cases. In the control group (endometrial adenocarcinoma group) the CEA and vimentin staining positive rates were 27.8% and 83.3% respectively, the difference was significant. The two year follow-up indicated that the incidence of recurrence, metastasis and mortality in the endocervical type were higher that those of other types. CONCLUSION: It is difficult to diagnose highly differentiated endocervical adenocarcinoma preoperatively, therefore adequate attention should be attached. Immunohistochemical staining can be used as an important basis for the diagnosis and differential diagnosis of cervical adenocarcinoma. The strongly positive results of PCNA staining, regardless of the degree of differentiation, proves that even highly differentiated adenocarcinoma exhibits a high degree of cell activity. Preliminary data suggests that cervical adenocarcinoma is related to HPV infection. Its relation with each HPV subtype remains to be clarified.

Adenocarcinoma↗
PubMed1999

[One hundred and twenty-four cases of diffuse pulmonary disease diagnosed by transbronchial lung biopsy via fiberbronchoscope].

OBJECTIVE: To understand the diagnostic value in diffuse pulmonary disease examined with transbronchial lung biopsy(TBLB) via fiber bronchoscope. METHOD: One hundred and twenty-four cases of diffuse pulmonary disease were diagnosed with TBLB via fiberbronchoscope. RESULT: Confirmed diagnosis was obtained in 91 patients; the total diagnostic rate was 73.39%. The kinds of the diseases included lung cancer, lung tuberculosis, diffuse interstitial pulmonary fibrosis, pulmonary sarcoidosis, and pulmonary lesion in collageous diseases. There were no other serious complications except for bloody or blood-streaking sputum, and pneumothorax occurred occasionally. CONCLUSION: It is suggested that TBLB is an easy, safe and useful method for diagnosing diffuse pulmonary diseases.

Adolescent↗
PubMed1999

[Temperature effect and temperature gradient technology in capillary electrophoresis].

A review is given here to describe the temperature effect and temperature gradient technology in capillary electrophoresis (CE). The temperature effects on the analysis of DNA, protein peptides and amino acids, enantiomers, carbohydrates and other substances are discussed respectively. The theory of temperature effect is also mentioned. The importance of the temperature gradient in CE, the classifications of gradient technology in CE, the potential applications and different method development of the temperature gradient are described. Fifty-one references are cited.

Amino Acids↗
PubMed1999

[Effect of postoperative treatment on endoscopic sinus surgery].

OBJECTIVE: To investigate the effect of postoperative treatment on endoscopic sinus surgery (ESS) and to discover the best way of care. METHOD: We checked 54 patients who had undergone ESS and been followed-up. RESULT: 7 cases (13.0%) were found with recurrent nasal polyps; 8 cases (14.8%) with recurrent sinusitis; 7 cases (13.0%) with adhesion and 10 cases (18.5%) with incomplete epithelialization. CONCLUSION: A suitable postoperative treatment and reasonable regular following-up by endoscopy is one of the important segment for securing optimal long-term result.

Adolescent↗
PubMed1999

[6A8 cDNA encodes A type of alpha-mannosidase].

OBJECTIVE: To find the nature of the protein encoded by 6A8 cDNA. METHODS: In the light of that the ligand of Con A is mannoses and that the function of alpha-mannosidase is trimming of mannoses in the oligosaccharide chains of glycoproteins, COS-7 cells and CNE-2L2 cells, a cloned cell line of human nasopharyngeal carcinoma, were transfected with pRc/CMV-sense 6A8 cDNA or pRc/CMV-antisense 6A8 cDNA and the Con A binding to the cells was examined upon a lazer scan confocal microscope. RESULTS: The data demonstrated that with transfection of pRc/CMV-sense 6A8 cDNA the binding of Con A to the cells was decreased, but the staining of the cells with mAb 6A8 was enhanced, and vise versa for the cells with transfection of pRc/CMV-antisense 6A8 cDNA. CONCLUSIONS: The protein encoded by 6A8 cDNA might be a type of alpha-mannosidase recognized by mAb 6A8.

Animals↗
PubMed1998

Activation of dihydrofolate reductase following thiol modification involves a conformational change at the active site.

Compared with the activation of dihydrofolate reductase (DHFR) by protein denaturants and inorganic salts, activation of the enzyme by thiol modification is relatively slow. Thus it is an ideal system for kinetic study of the activation mechanism. We describe here a kinetic study of the activation of DHFRs from chicken liver and Chinese hamster ovary by p-hydroxymercuribenzoate (p-HMB). The conformational changes in the enzyme molecule that result from the modification were monitored by measuring fluorescence enhancement due to the binding of 2-p-toluidinylnaphthalene-6-sulphonate (TNS), and by monitoring changes in the intrinsic fluorescence of the enzyme. Both activation and the conformational change probed by TNS followed pseudo-first-order kinetics, and the rate constants obtained are in good agreement with each other. The change in intrinsic fluorescence is a biphasic process. The rate of the fast phase, which may reflect a change in the microenvironment of Trp-24 at the active site, coincides with the rate of activation and the conformational change probed by TNS. The rate of the slow phase, which reflects a global conformational change, is about one order of magnitude lower than that of activation. The results indicate that the activation of DHFR by p-HMB is due to modification-induced conformational changes at its active site, rather than the modification of the thiol group itself, which is almost complete within the dead-time of the experiment. This study provides kinetic evidence for the proposal that flexibility at the active site is essential for full expression of catalytic activity.

Animals↗
PubMed1998

Comparison of murine Supt4h and a nearly identical expressed, processed gene: evidence of sequence conservation through gene conversion extending into the untranslated regions.

We show herein the transcription of a processed gene that originated from a spliced transcript. Recently, we isolated the human and murine homologues of the yeast chromatin protein, SPT4. The Supt4h gene is spliced normally from five exons encoded by chromosome 11. Here we show that a related sequence on chromosome 10 encodes Supt4h2, a processed intronless gene (with a polyA tail and a tandemly-duplicated 13 bp insertion site in the genome) with a different 5' control region. Both the spliced gene, Supt4h , and the processed gene, Supt4h2 , are expressed in each of four tissues we examined. Supt4h2 encodes a 117 amino acid protein nearly identical to the Supt4h gene product with only one amino acid difference, indicating extreme conservation of this expressed processed gene with the spliced gene over evolutionary time. This illustrates another potential complexity of the mammalian genome, i.e. the use of a processed gene under the control of a different promoter region than the spliced gene.

Animals↗
PubMed1998

Cloning and characterization of a novel human hepatocyte transcription factor, hB1F, which binds and activates enhancer II of hepatitis B virus.

Enhancer II (ENII) of hepatitis B virus (HBV) is one of the essential cis-elements for the transcriptional regulation of HBV gene expression. Its function is highly liver-specific, suggesting that liver-enriched transcriptional factors play critical roles in regulating the activity of ENII. In this report, a novel hepatocyte transcription factor, which binds specifically to the B1 region (AACGACCGACCTTGAG) within the major functional unit (B unit) of ENII, has been cloned from a human liver cDNA library by yeast one-hybrid screening, and demonstrated to trans-activate ENII via the B1 region. We named this factor hB1F, for human B1-binding factor. Amino acid analysis revealed this factor structurally belongs to nuclear receptor superfamily. Based on the sequence similarities, hB1F is characterized to be a novel human homolog of the orphan receptor fushi tarazu factor I (FTZ-F1). Using reverse transcription-polymerase chain reaction, a splicing isoform of hB1F (hB1F-2) was identified, which has an extra 46 amino acid residues in the A/B region. Examination of the tissue distribution has revealed an abundant 5.2-kilobase transcript of hB1F is present specifically in human pancreas and liver. Interestingly, an additional transcript of 3.8 kilobases was found to be present in hepatoma cells HepG2. Fluorescent in situ hybridization has mapped the gene locus of hB1F to the region q31-32.1 of human chromosome 1. Altogether, this study provides the first report that a novel human homolog of FTZ-F1 binds and regulates ENII of HBV. The potential roles of this FTZ-F1 homolog in tissue-specific gene regulation, in embryonic development, as well as in liver carcinogenesis are discussed.

Amino Acid Sequence↗
PubMed1998

Induction of PPARgamma1 expression in human THP-1 monocytic leukemia cells by 9-cis-retinoic acid is associated with cellular growth suppression.

9-cis-Retinoic acid (RA) and peroxisome proliferator activated receptor gamma (PPARgamma) regulates cellular growth and differentiation. In THP-1 cells, a human monocytic leukemia cell line, RA markedly induced PPARgamma1 RNA, nuclear PPARgamma1 protein and suppressed cell growth. The PPARgamma ligand, BRL49653 enhanced RA's growth suppression ability. With BRL49653 alone, THP-1 cell growth was only marginally suppressed. Cell cycle analysis revealed the G1 phase cell population was significantly increased when cells were treated with both ligands. RA induced growth suppression did not differentiate the THP-1 cells to macrophages. Phorbol ester (PMA) induced differentiation of cells to macrophage also induced PPARgamma1 expression, however when RA is given either simultaneously or sequentially to these cells, no further increase in expression of the nuclear receptor was observed. Overall, these data suggest RA induction of PPARgamma1 may block cell growth and may have application for the treatment of proliferative diseases.

Alitretinoin↗
PubMed1998

Modulation of endoplasmic reticulum calcium pump by Bcl-2.

Members of the bcl-2 gene family encode proteins that function either to promote or to inhibit apoptosis. Despite numerous efforts, the mechanism of action of Bcl-2, an anti-apoptotic protein, is still not clear. In particular, the relation between Bcl-2 and the endoplasmic reticulum (ER) calcium store is not well-understood. In the present work, we examined the effect of Bcl-2 on the ER store. We demonstrate that overexpression of Bcl-2 in breast epithelial cells modulates ER store by upregulating calcium pump (SERCA) expression without affecting the release channel (IP3R). The steady state levels of SERCA2 mRNA and protein were both increased in Bcl-2 expression clones. The increase in SERCA2 protein leads to accelerated calcium uptake and enhanced Ca2+ loading. In addition, we also show the detection of intracellular interaction between Bcl-2 and SERCA molecules by co-immunoprecipitation. Since high lumenal Ca2+ concentration of ER is essential for normal cell functions, the results suggest that Bcl-2 preserves the ER Ca2+ store by upregulating SERCA gene expression as well as by a possible interaction with the pump.

Calcium↗
PubMed1998

Human herpesvirus-8 ORF K8.1 gene encodes immunogenic glycoproteins generated by spliced transcripts.

A cDNA library from phorbol ester-induced human herpesvirus-8 (HHV-8) carrying BCBL-1 cells was screened with an HIV+KS+ serum, and several cDNA clones encoding HHV-8 proteins were identified. Sequence analysis of two full-length cDNA clones show open reading frames (ORFs) encoded by spliced messages originating from the HHV-8 K8.1 gene. One cDNA encodes an ORF of 228 amino acids, designated K8. 1.A, with a cleavable signal sequence, a transmembrane domain, and four N-glycosylation sites. The splicing event generated the transmembrane domain in the ORF not seen in the genomic K8.1 ORF. Another cDNA encodes an ORF of 167 amino acids, designated K8.1.B, that shares similar amino and carboxyl termini with ORF K8.1.A but with an in-frame deletion. The primary translation products of ORF K8.1A (34 kDa) and K8.1B (20 kDa) in the in vitro-transcription-translation experiments shifted into glycosylated species of 43 and 32 kDa, respectively, in the presence of microsomal membranes. This suggested that the ORF K8.1A and K8.1B encode for glycoproteins. Riboprobes from the K8.1A cDNA insert hybridized with an HHV-8-specific 0.9-kb abundant transcript from BCBL-1 cells. Synthesis of this RNA was eliminated in the presence of a DNA synthesis inhibitor, suggesting that this RNA was a late gene transcript. Because ORFs K8.1A and K8.1B are unique for HHV-8, human sera were tested in Western blot reactions for antibodies against glutathione-S-transferase-ORF K8.1A fusion protein. All sera that were positive for HHV-8 antibodies in immunofluorescence assays with phorbol ester-induced BCBL-1 cells were also positive for anti-ORF K8.1A antibodies. This suggests that measurement of anti-ORF K8.1A antibodies would provide an HHV-8-specific serological assay. Further work is needed to define the biological role of the HHV-8 ORF K8.1A and K8.1B glycoproteins.

Amino Acid Sequence↗
PubMed1998

Apolipoprotein(a) binds via its C-terminal domain to the protein core of the proteoglycan decorin. Implications for the retention of lipoprotein(a) in atherosclerotic lesions.

Although it is known that lipoprotein(a) (Lp(a)) binds to proteoglycans, the mechanism for this binding has not been fully elucidated. In order to shed light on this subject, we examined the interactions of decorin, a proteoglycan with a well defined protein core and a single glycosaminoglycan (GAG) chain, with Lp(a) and derivatives, namely Lp(a) deprived of apo(a), or Lp(a-), free apo(a), and the two main proteolytic fragments, F1 and F2. By circular dichroism criteria, the decorin preparations used had the same secondary structure as that previously reported for native decorin. Authentic low density lipoprotein from the same human donor was used as a control. In a solid phase system, Lp(a-)and low density lipoprotein bound to decorin in a comparable manner. This binding required Ca2+/Mg2+ ions, was lysine-mediated, and was markedly decreased in the presence of GAG-depleted decorin, suggesting the ionic nature of the interaction likely involving apoB100 and the GAG component of decorin. Free apo(a) also bound to decorin; however, the binding was neither cation-dependent nor lysine-mediated, unaffected by sialic acid depletion of apo(a), and markedly decreased when either reduced and alkylated apo(a) or reduced and alkylated decorin was used in the assay. Of note, the binding of apo(a) was unaffected when it was incubated with a spectrally native decorin that had been renatured from either 4 M guanidine hydrochloride by extensive dialysis or cooled from 65 to 25 degrees C. On the other hand, the binding significantly increased when decorin was depleted of GAGs, which by themselves had no affinity for apo(a). The binding of apo(a) to the decorin protein core was also elicited by the C-terminal domain of apo(a), and it was favored by high NaCl concentrations, 1 to 2 M. No binding was exhibited by the N-terminal domain accounting for the lack of effect of apo(a) size polymorphism on the binding. In the case of whole Lp(a), the binding to immobilized decorin was mostly GAG-dependent and ionic in nature. A minor contribution by apo(a) was detected when GAG-depleted decorin was used in the assay. Our results indicate that the binding of Lp(a) to decorin involves interactions both electrostatic (apoB100-GAG) and hydrophobic (apo(a)-decorin protein core), and that the binding of apo(a) requires decorin protein core to be in its native state.

Animals↗
PubMed1998

Blood perfusion measurements in the canine prostate during transurethral hyperthermia.

Using a thermal pulse decay technique, blood perfusion rates were measured within different regions in the canine prostate under normal and hyperthermic conditions induced either by the microwave or the radio frequency heating. Results indicate that, under the normal condition, the periurethral region is most highly perfused with an average rate of 0.60 +/- 0.25 ml/min/gm (n = 4) while the perfusion rate is 0.34 +/- 0.22 ml/min/gm (n = 10) in parenchyma. An approximately 3.5 fold increase in perfusion from the respective baselines was observed in both regions when the local tissue temperature was raised to 41.5 degrees C by the microwave heating. Another 0.5 fold increase was found in parenchyma after the tissue was further heated to 43.1 degrees C at which oscillatory behaviors in tissue temperature have been observed. To further study the cause of these oscillatory behaviors, the instantaneous blood perfusion response to changes in local tissue temperature was investigated using the radio frequency heating. It has been revealed that blood flow acts as a feedback of local tissue temperature in a closed control system. The thermally stimulated blood perfusion increase appeared to be a function of tissue temperature and its temporal gradient. Results from this study have shown experimental evidences of local thermoregulation in the prostate during hyperthermia.

Animals↗