Biomedical subjects

W Ji

Publications and source records attributed to W Ji.

At least 55 records · Page 3Linked to original sources

PubMed1999

[Apoptosis of peripheral blood lymphocytes of patients with chronic hepatitis B and clinical significance].

OBJECTIVE: To explore the effects of apoptosis of peripheral blood lymphocytes (PBLs) of patients with chronic hepatitis B (CHB) on the persistent infection of hepatitis B virus (HBV). METHODS: The PBLs of 15 patients with CHB were isolated and cultured with or without Staphylococcus aureus enterotoxin B (SEB; 0.2 mg/L), or in the presence or absence of recombinant HBcAg (rHBcAg; 1.0 mg/L) for 48 hours in vitro. After incubations, the cells were harvested by centrifugation and then apoptosis of the PBLs was studied by staining with fluorescent dyes YOPRO-1 and Hoechst33342. RESULTS: The percentage of apoptotic cells of PBLs of patients with CHB was significantly higher than in normal controls (P < 0.01) in the presence or absence of SEB or rHBcAg, but the ratio of apoptotic cells in rHBcAg-stimulated PBLs of the patients was the highest, reaching (24.6 +/- 6.1)%. The patients with seropositive for HBeAg had higher percentage of apoptotic cells in their cultured PBLs than those with seronegative for HBeAg had, but the ratio of apoptotic cells in cultured PBLs of the patients with chronic heavy and severe hepatitis B was lower than that of the patients with chronic mild and moderate hepatitis B (P < 0.01). CONCLUSION: Activation-induced cell death of PBLs of the patients with CHB may be related to persistent infection of HBV, and assay of apoptosis of PBLs of patients with CHB may provide valuable information about pathogenesis of CHB.

Adolescent↗

PubMed1999

[Interleukin 10(IL-10) levels in serums and in culture supernatants of peripheral blood mononuclear cells from patients with chronic hepatitis B].

OBJECTIVE: To understand the impacts of interleukin 10(IL-10) in serums and in culture supernatants of peripheral blood mononuclear cells (PBMCs) from patients with chronic hepatitis B (CHB) on the persistent infection of hepatitis B virus (HBV). METHODS: The levels of IL-10 in serums and in culture supernatants of PBMCs from 15 patients with CHB and 6 normal controls were measured by ELISA method. PBMCs were cultured with or without Staphylococcus aureus enterotoxin B(SEB; 0.2 microgram/ml) or recombinant HBcAg(rHBcAg; 1.0 microgram/ml) for 48 hours in vitro. RESULTS: The levels of IL-10 in serums was greater in patients with CHB (123.11 +/- 13.89 ng/L) than in controls (95.97 +/- 11.68 ng/L, P < 0.01). Spontaneous, SEB-induced and rHBcAg-induced IL-10 production by PBMCs after culturing in vitro for 48 hours was also higher in patients with CHB (280.82 +/- 50.56 ng/L, 321.69 +/- 37.04 ng/L and 369.58 +/- 30.52 ng/L) than in controls (100.2 +/- 8.54 ng/L, 203.41 +/- 12.02 ng/L and 202.38 +/- 15.79 ng/L; P < 0.01). In addition, IL-10 production by rHBcAg-stimulated PBMCs was significantly greater than by SEB-stimulated PBMCs in patients with CHB. Patients with seropositive for HBV DNA had higher levels of IL-10 in serums and in culture supernatants of PBMCs than patients with seronegative for HBV DNA. But the levels of IL-10 were lower in patients with chronic heavy and severe hepatitis B than in patients with chronic mild and moderate hepatitis B. CONCLUSION: IL-10 may have an important role in persistent infection of HBV in patient with CHB.

Adolescent↗

PubMed1999

[One-stage reconstruction with the pedicle skin flap of forehead for defective tissue of head-neck tumors dissection].

OBJECTIVE: To discuss the feasibility on reconstructing the defective tissue with the pedicle skin flap of forhead after head-neck tumors dissection. METHOD: 14 patients with advanced head-neck tumors were studied, whose defective tissues were reconstructed by their forehead skin flaps. The flap area ranged from 5 cm x 11 cm to 7 cm x 16 cm. RESULT: 2 cases of them were partial necrosis, 3 years and 5 years survival rates were 76.9% and 63.6% respectively. The function of breath through nose or mouth and the function of swallow were satisfactory. CONCLUSION: The forehead skin flap should be a good selection for the reconstruction of defective tissue after basicranial and nasalfacial dissection.

Adolescent↗

PubMed1999

[Pathologic feature of occult lymphatic metastasis in supraglottic carcinoma].

OBJECTIVE: To study the pathologic features of occult lymphatic metastasis in patients with supraglottic carcinoma and its implication in treatment. METHODS: Serial sections of 153 neck dissection specimens in 100 patients with supraglottic carcinoma were studied under microscope. RESULTS: Clinically negative nodes had been proved histologically positive in 58 specimens (38%) and 51 occult nodes, size ranged from 0.5 cm to 2.6 cm with average of 1.1 cm. The distribution of metastastic lymph nodes was 1 in level I (2%), 37 in level II (73%), 12 in level III(23%) and 1 in level IV(2%). Among the 51 nodes, 21(41%) were in early stage, 18 (35%) in growth stage, 7(14%) in full stage, 5(10%) were extracapsular. CONCLUSION: Occult metastasis rate of supraglottic carcinoma is as high as 38%, selective neck dissection is recommended for the surgical treatment of this disease.

Adult↗

PubMed1998

Identification of PKDL, a novel polycystic kidney disease 2-like gene whose murine homologue is deleted in mice with kidney and retinal defects.

Polycystin-1 and polycystin-2 are the products of PKD1 and PKD2, genes that are mutated in most cases of autosomal dominant polycystic kidney disease. Polycystin-2 shares approximately 46% homology with pore-forming domains of a number of cation channels. It has been suggested that polycystin-2 may function as a subunit of an ion channel whose activity is regulated by polycystin-1. Here we report the identification of a human gene, PKDL, which encodes a new member of the polycystin protein family designated polycystin-L. Polycystin-L has 50% amino acid sequence identity and 71% homology to polycystin-2 and has striking sequence and structural resemblance to the pore-forming alpha1 subunits of Ca2+ channels, suggesting that polycystin-L may function as a subunit of an ion channel. The full-length transcript of PKDL is expressed at high levels in fetal tissues, including kidney and liver, and down-regulated in adult tissues. PKDL was assigned to 10q24 by fluorescence in situ hybridization and is linked to D10S603 by radiation hybrid mapping. There is no evidence of linkage to PKDL in six ADPKD families that are unlinked to PKD1 or PKD2. The mouse homologue of PKDL is deleted in Krd mice, a deletion mutant with defects in the kidney and eye. We propose that PKDL is an excellent candidate for as yet unmapped cystic diseases in man and animals.

Amino Acid Sequence↗

PubMed1998

Hypomethylation of pericentromeric DNA in breast adenocarcinomas.

Drug-induced DNA demethylation in normal human cells and inherited localized hypomethylation in mitogen-stimulated lymphocytes from patients with a rare recessive disease (ICF: immunodeficiency, centromeric region instability, facial anomalies) are associated with karyotypic instability. This chromosomal recombination is targeted to heterochromatin in the vicinity of the centromere (pericentromeric region) of human chromosome 1. Pericentromeric rearrangements in this chromosome as well as overall genomic hypomethylation are frequently observed in many kinds of cancer, including breast adenocarcinoma. We found that almost half of 25 examined breast adenocarcinomas exhibited hypomethylation in satellite 2 DNA, which is located in the long region of heterochromatin adjacent to the centromere of chromosome 1 and is normally highly methylated. One of the 19 examined non-malignant breast tissues displaying fibrocystic changes was similarly hypomethylated in this satellite DNA. We also looked at an opposing type of methylation alteration in these cancers, namely, hypermethylation in a tumor-suppressor gene region that is frequently hypermethylated in breast cancers. We found that increased methylation in the E-cadherin promoter region and decreased methylation in satellite 2 DNA were often present in the same breast cancers. While hypermethylation in certain tumor-suppressor gene regions may favor tumorigenesis by repressing transcription, demethylation of other DNA sequences may predispose to cancer-promoting chromosomal re-arrangements.

Adenocarcinoma↗

PubMed1998

[Significance of pathological type in cervical lymph metastasis of laryngeal cancer].

To research significance of pathological type in cervical lymph metastasis of laryngeal cancer. Observing metastasis lymph nodes in serial sections of 55 cases neck dissection specimens with microscope. Single type 21 cases, 90% of them were occult metastasis, three-year survival rate was 90%. Multiple types 10 cases, 70% of them were occult metastasis, three-year survival rate was 70%. Gathering type 24 cases, 92% of them can be palpated by physician, three-year survival rate was 54%. It is suitable that cervical metastasis lymph nodes of laryngeal cancer were divided into three types in pathology. It is significance for treatment and prognosis.

Adult↗

PubMed1998

[Childhood rhadomyosarcoma in head and neck].

2 cases childhood rhadomyosarcoma in head and neck were reported, both patients were treated by surgery, radiotherapy or chemotherapy. The pathologic type, clinical stage, diagnosis, treatment and prognosis of the childhood rhadomyosarcoma were discussed.

Child↗

PubMed1998

[Cervical necrotizing fasciitis].

Necrotizing fasciitis is a severe fatal soft tissue infection characterized by necrosis of fascia. It was caused by polymicrobial infections with aerobe and anaerobe. Although it commonly involved abdomen, extremities and perineum, it might also occur in head and neck. One case of CNF arising from pharyngolaryngitis was reported. A review of the literature with the clinical presentations, bacteriology, diagnosis and treatment was presented. The key to successful management is early recognition, broad-spectrum antibiotics and prompt aggressive surgical intervention with medical support and hyperbaric oxygen therapy.

Fasciitis, Necrotizing↗

PubMed1998

[Quantitative analysis of vestibulo-ocular reflex and optokinetic reflex electronystagmography in patients with unilateral loss of vestibular function].

OBJECTIVE: To study changes of the vestibular function in the process of vestibular compensation. METHODS: The electronystagmography recording of spontaneous nystagmus(SN) with tests for vestibulo-ocular reflex (VOR) and optokinetic reflex (OKR) were performed in 105 patients with unilateral loss of vestibular function, the results were analysed quantitatively. RESULTS: (1) Twenty-one patients with courses from 3 days to 6 years presented a SN directed towards the intact side, with an average slow phase velocity (ASPV) of 7.12-12.07 degrees/s. (2) The intensity of VOR nystagmus as a response to the warm-cold water stimulation to the intact ear was lower than that of normal subjects. (3) By 0.167 Hz, 90 degrees sinusional oscillation stimulation, the ASPVs of the patients' VOR nystagmus directed towards the intact and affected sides were lower than that of the normal. A predominance of VOR nystagmus rotation towards the intact side was found in patients with courses < or = 5 years. There was no predominance of VOR nystagmus found in patients with courses > 5 years. (4) There was no significant difference between the optokinetic nystagmus (OKN) intensity of the normal persons and that of patients with lesions outside the cerebellopontine angle and with tumors in cerebellopontine angle which was < 2.5 cm in diameter. The OKN intensity of patients with tumors in cerebellopotine angle with diameters > or = 2.5 cm was lower than that of normal subjects. A predominance of OKN towards the intactside was found in these patients. CONCLUSION: The vestibular function is in inhibitory and the vestibular system becomes rebalanced due to this inhibition in the process of vestibular compensation.

Adolescent↗

PubMed1998

[Analysis of trace Pd in marine deposit samples using laser-excited atomic fluorescence spectrometry].

Laser-excited atomic fluorescence spectrometry and its experimental set-up are introduced in this paper. Using this spectrometer, Pd contents in 36 marine deposit samples of the East-sea continental shelf were analyzed. The results show that the detection limit and the precision of this spectrometer are 50 pg/mL and 6% respectively, and the measurements of Pd in marine deposit samples are reliable.

English Abstract↗

PubMed1997

Reexpression of the retinoblastoma protein in tumor cells induces senescence and telomerase inhibition.

Normal human diploid cells senesce in vitro and in vivo after a limited number of cell divisions. This process known as cellular senescence is an underlying cause of aging and a critical barrier for development of human cancers. We demonstrate here that reexpression of functional pRB alone in RB/p53-defective tumor cells via a modified tetracycline-regulated gene expression system resulted in a stable growth arrest at the G0/G1 phase of the cell cycle, preventing tumor cells from entering S phase in response to a variety of mitogenic stimuli. These cells displayed multiple morphological changes consistent with cellular senescence and expressed a senescence-associated beta-galactosidase biomarker. Further studies indicated that telomerase activity, which was assumably essential for an extended proliferative life-span of neoplastic cells, was abrogated or repressed in the tumor cell lines after induction of pRB (but not p53) expression. Strikingly, when returned to an non-permissive medium for pRB expression, the pRB-induced senescent tumor cells resumed DNA synthesis, attempted to divide but most died in the process, a phenomenon similar to postsenescent crisis of SV40 T-antigen-transformed human diploid fibroblasts in late passage. These observations provide direct evidence that overexpression of pRB alone in RB/p53-defective tumor cells is sufficient to reverse their immortality and cause a phenotype that is, by all generally accepted criteria, indistinguishable from replicative senescence. The results suggest that pRB may play a causal role in the intrinsic cellular senescence program.

Cellular Senescence↗

PubMed1997

DNA demethylation and pericentromeric rearrangements of chromosome 1.

Rearrangements in the vicinity of the centromere of chromosome 1 are over-represented in many types of human cancer and are a characteristic feature of a rare genetic disease called ICF (immunodeficiency, centromeric heterochromatin instability, and facial anomalies). Evidence is presented that implicates DNA hypomethylation in the formation of these pericentromeric chromosomal anomalies. The DNA methylation inhibitors 5-azadeoxycytidine and 5-azacytidine, but not other tested genotoxins, induced the preferential formation of pericentromeric rearrangements of chromosome 1 at a very high frequency in a pro-B-cell line (FLEB14) and at a lower frequency in a mature B-cell line (AHH-1). These abnormal chromosomes appear identical to the diagnostic chromosomal aberrations in the ICF syndrome. A major component of the pericentromeric DNA in chromosome 1, satellite 2, was shown to be hypomethylated in an ICF B-cell line, although DNA from this cell line did not display detectable overall hypomethylation. It is hypothesized that demethylation in certain DNA regions, including in pericentromeric satellite DNA, helps lead to pericentromeric chromosomal rearrangements in lymphocytes from ICF patients and in normal lymphoblastoid cells incubated in vitro with DNA demethylating agents.

Adult↗

PubMed1997

Development of an adenovirus vector with tetracycline-regulatable human tumor necrosis factor alpha gene expression.

Tumor necrosis factor alpha (TNF-alpha) is a multifunctional cytokine with direct antitumor activity. However, clinical trials using TNF-alpha for cancer treatment have been disappointing due in part to its severe side effects, and it has been estimated that TNF-alpha therapy would be effective only at 5-25 times the maximum tolerated dose. We have recently modified a tetracycline (Tc) repressor/operator-based mammalian gene expression system and have generated a Tc-responsive recombinant adenovirus vector, AdVtTA.TNF-alpha. A variety of human tumor cells and T lymphocytes transduced by AdVtTA.TNF-alpha secreted high-titer (5,000-100,000 pg/10(6) cells/24 h) and biologically active TNF-alpha in the absence of Tc. Expression of TNF-alpha in the transduced cells was nondetectable when the culture medium contained as little as 0.1 microg/ml of Tc. At least a fraction of the clonogenic cells from human peripheral blood stem cell concentrates were also transducible by AdVtTA.TNF-alpha. The availability of this type of adenovirus vector opens a door to tumor- or organ-specific delivery of high-dose TNF-alpha and other therapeutic gene products for systemic cancer gene therapy.

Adenoviridae↗

PubMed1997

Inhibition of hepatitis B virus by retroviral vectors expressing antisense RNA.

Two retroviral vectors carrying an antisense gene from the hepatitis B virus (HBV) preS/S or preC/C were constructed and used to infect the human hepatoblastoma cell line 2.2.15, which expresses HBV surface antigen (HBsAg), HBV e antigen (HBeAg) and releases HBV particles. The results showed that the inhibitory effects of antisense gene transfer, mediated by retroviral vectors on the expression of HBV antigens, appeared as early as day 3 after transduction, reached a maximum on day 5 and persisted for at least 11 days. Our data indicate that, on day 5 after introduction, antisense preS/S inhibited HBsAg and HBeAg expression by 71% and 23%, and the antisense preC/C inhibited HBsAg and HBeAg expression by 23% and 59%. HBV DNA production, in the supernatant of the 2.2.15 cells transduced with either antisense preS/S or preC/C, was also reduced on day 5, but the viability of the 2.2.15 cells was not affected. Our results demonstrate that the replication and expression of HBV can be inhibited through antisense gene transfer mediated by retroviral vectors and that the antisense-preC/C or antisense-preS/S may be potentially useful for clinical gene therapy against HBV.

3T3 Cells↗

PubMed1997

[Clinical and pathological study on cervical lymph node metastasis of supraglottic cancer].

AIM: To study pathological features of cervical lymph node metastasis and the relationship between supraglottic cancer and cervical lymph node metastasis. METHOD: Observation of 100 whole-organ serial sections of the larynges and 170 sides of the radical neck dissection specimens. RESULTS: 1. Cervical lymph node metastasis 55 cases, metastatic rate 55%; 2. Four series of cervical metastasis: clinico-pathologic metastases (29 cases), pathologic metastases (26 cases), clinical metastases (5 cases), no metastasis (40 cases). 3. Four stages of metastatic lymphnode: early stage, growth stage, fullness stage and capsular perforative stage; 4. Three types of metastases: single type (21 cases), multiple type (10 cases) and aggregated (24 cases) type. 5. Metastatic rates of supraglottic cancer of different regions: aryepiglottic fold 85.7%, arytenoid cartilage area 66.6%, epiglotto-ventricular fold 56.8%, epiglottic 46.4%, ventricular fold 45.4%. 6. When the tumour spread to the perilaryngeal region, the metastatic rate was 80% to 84%. CONCLUSION: Metastatic rate of cervical lymph node is higher in supraglottic cancers, the aggregated type and capsular perforative stage are more in metastasis lymph nodes. Analysis the original sites of supraglottic cancer is conductive to the prediction of the cervical lymph node metastasis.

Glottis↗

PubMed1997

[The value of the ratio of--SP/AP in diagnosing Ménière's disease].

To further explore the diagnostic value of the ratio of--SP/AP (> 0.4) in Ménière's disease, the EcochG results from 70 (76 ears) cases with Ménière's disease were compared to that of 49 cases with sudden hearing loss(SHL), noise induced hearing loss(NIHL), ototoxic hearing loss, and 20 normal hearing person. The effects of different stimulus intensities and the degree of hearing loss on the detectable rate of--SP, the ratio of--SP/AP and its feature in the above mentioned disease were analysed. The results indicated: 1. The mean ratio of--SP/AP was 0.39 +/- 0.02 in normal person on 75 dB nHL stimulus level, while it was larger than 0.45 in SHL and NIHL on 75 dB and 65 nHL stimulus level respectively. 2. There was a rapid descending trend of the ratio of--SP/AP with stimulus level from 65 to 55 dB nHL in all ears except Ménière's cases, which was correlated with stimulus level as well as the degree of hearing loss. 3. The mean ratio of--SP/AP presented linear increase when stimulus level was < or = 75 dB nHL, and when stimulus level was > 75 dB nHL, the mean ratio of--SP/AP no longer presented linear increase and could even decrease, it suggested stimulus level on 75 dB nHL could be used as the diagnostic stimulus level. 4. If the degree of hearing loss exceeded 80 dB HL, the ratio of--SP/AP > 0.4 had no practical significance in diagnosis.

Adolescent↗

PubMed1997

[Transcription of antisense RNA of hepatitis B virus through retroviral mediated gene transfer].

To probe the ways by which the antisense gene of hepatitis B virus (HBV) can be transferred and transcripted in eukaryotic cells to inhibit HBV replication and expression. Two retroviral vectors that carried antisense gene of hepatitis B virus (HBV) PreC/C or PreS/S region were constructed. The HBV ayw PreC/C and PreS/S fragments were inserted into the vector pDO. R cloning site in the sense or antisense orientation and the recombinant retroviral vectors were then transfected into PA317 packaging cells by calcium phosphate coprecipitation, respectively. The stably transformed G418-resistant PA317 cells were selected and the recombinant retroviruses released from transfected G418-resistant PA317 cells were assayed by G418 selection method, using NIH 3T3 cells as target cells. Southern blot and RNA Dot blot analysis showed that the recombinant retroviral vector sequences were stably integrated into the chromosome of transfected PA317 cells and the antisense RNA of HBV PreS/S or PreC/C gene also transcripted in the transduced NIH 3T3 cells. These results suggested that antisense gene of HBV can be successfully transferred and transcripted in target cells through retroviral vector mediated gene transfer and the antisense retroviral vectors may be potentially useful for anti-HBV gene therapy.

Animals↗