Biomedical subjects

M Guo

Publications and source records attributed to M Guo.

At least 73 records · Page 4Linked to original sources

PubMed2000

A randomized controlled clinical trial on etimicin, a new aminoglycoside antibiotic, versus netilmicin in the treatment of bacterial infections.

OBJECTIVE: To compare the efficacy and safety of two aminoglycoside antibiotics, etimicin and netilmicin, in the treatment of bacterial infections. METHODS: A randomized, open label, controlled clinical trial was conducted for the treatment of 65 patients hospitalized with respiratory tract infections, urinary tract infections, and skin and tissue infections. Thirty-four patients received etimicin and thirty-one patients received netilmicin at a dose of 100 mg every 12 hours by intravenous infusion. The duration of treatment was 7-10 days in both groups. RESULTS: 47 patients were enrolled in the etimicin group; 35 patients were assessable for safety and 34 patients were assessable for efficacy, 46 patients were enrolled in the netilmicin group; 32 patients were assessable for safety and 31 patients were assessable for efficacy. The results show that overall efficacy was 85.3% for the etimicin group and 83.9% for the netilmicin group, whereas bacterial clearance rates were 87.5% for the etimicin group and 89.7% for the netilmicin group. The incidence of adverse reactions was 8.6% (3/35) and 9.4% (3/32), respectively. CONCLUSION: Etimicin and netilmicin were effective and safe for the treatment of respiratory tract infection, urinary tract infection, and skin and tissue infections. The results show there was no statistically significant difference between the two groups (P > 0.05).

Adolescent↗

PubMed2000

Dysregulation of apoptosis: a possible mechanism leading to chronic progressive renal histological changes in lupus nephritis.

OBJECTIVE: To evaluate apoptosis in lupus nephritis and the relationship between the existence of apoptotic cells in renal tissue and histopathological or clinical changes. METHODS: Apoptosis was detected by in situ nick-end labeling techniques (TUNEL) in renal biopsies from 25 patients with type IV lupus nephritis (LN), 12 patients with IgA nephropathy IgAN, 4 patients with idiopathic mesangioproliferative glomerulonephritis (MsPGN) and 3 patients with acute poststreptococcal glomerulonephritis (APGN). Normal renal tissue obtained at nephrectomy for hypernephroma in 4 adults was used as control. Proliferating cells were identified by proliferating cell nuclear antigen (PCNA) in these patients. RESULTS: Compared to other proliferative glomerulonephritis and controls, the patients with lupus nephritis had less apoptotic cells, a higher ratio of PCNA + cells/TdT + cells (P/T) in renal tissues; and their P/T ratio in glomeruli and tubulointerstitium correlated with the chronicity index, r = 0.4983 (P = 0.0132), r = 0.8399 (P < 0.001), r = 0.6614 (P = 0.0033), respectively. P/T ratios in the glomerulus and tubule had a positive correlation with 24-hour urinary protein, r = 0.8554 (P < 0.001) and r = 0.7134 (P = 0.001); and a negative correlation with creatinine clearance (Ccr), r = -0.4880 (P = 0.0133) and r = -0.7229 (P = 0.001), which in tubules positively correlated with serum creatinine (Scr), r = 0.4107 (P = 0.0414). CONCLUSIONS: Apoptosis is reduced in proliferative lupus nephritis. Intense proliferation without a commensurate increase in apoptosis is a possible mechanism that leads to chronic progressive renal histopathological changes.

Adult↗

PubMed2000

[The effect of TGF-beta1 on the expression of plasminogen activator inhibitors 1 and matrix metalloproteinases in cultured rat mesangial cells transfected with antisense-TGF-beta1 vector].

OBJECTIVE: To study the plasminogen activator inhibitors 1 (PAI-1) and matrix metalloproteinases (MMPs) expression on the cultured rat mesangial cells (MsC) transfected with antisense-TGF-beta1 vector. METHODS: Lipofectin method was used to transfect antisense-TGF-beta1 vector into MsC, Western blot and Northern blot analysis for detecting TGF-beta1 peptides and antisense TGF-beta1 RNA level. The expression of PAI-1 and MMPs were determined by Northern blot, Western bolt and zymography assay. RESULTS: The MsC clone (MAT1) which blocked the expression of TGF-beta1 peptides was successfully established. The MsC clone showed increased expression of MMP-2 mRNA protein and enzyme activity of MMP-2, 3, 7. However, expression of PAI-1 mRNA of MsC clone was suppressed. CONCLUSION: Blocked expression of TGF-beta1 can upregulate the expression of MMP-2, 3, 7 and downregulate the expression of PAI-1 mRNA in MsC. It is possible that antisense-TGF-beta1 may be used for gene therapy in glomerular diseases.

Animals↗

PubMed2000

[A report of two Chinese familial Budd-Chiari syndrome].

OBJECTIVE: To investigate the etiology of two Chinese familial Budd-Chiari syndrome (BCS). METHOD: Four patients with familial BCS (from A and B families), and the other 41 family members were detected by angiography, ultrasound Dopler, etiology analysis and Factor V Leiden (FvL) mutation analysis. RESULT: Four BCS patients were proved by angiography, 2 by ultra sound Dopler in family A. Ten members in family A were varicosis in low extremeties. FvL mutation was detected in 4 of 6 patients and 2 normal family members. A II(2), A III(7, 11, 15,) B II(10) and B III(5) had FvL mutation. The FvL mutations were compatible with Mendel hereditary law. CONCLUSION: FvL mutation may be one of main risk factors and varicosis in low extremeties may be another risk factors for familial BCS.

Adolescent↗

PubMed2000

[Assessment on application of Chinese herbs in process of corticosterone reduction in nephrotic syndrome].

OBJECTIVE: To evaluate the effect of Chinese herbs in the process of corticosterone (CS) reduction in nephrotic syndrome. METHODS: One hundred and twenty patients of idiopathic nephrotic syndrome sensitive to prednisone treatment were divided into two groups randomly. The dosage of prednisone used was reduced by routine in both groups but Chinese herbal treatment was added to the treated group in the period of prednisone reduction. The effect of Chinese herbs was estimated by observing the recurrence rate of disease and side-effects of prednisone. RESULTS: The recurrence rate of disease and the occurrence rate of side-effects of prednisone in the treated group were lesser than that in the control group significantly (P < 0.01). CONCLUSION: Additional Chinese herbs in the process of CS reduction in the treatment of CS sensitive nephrotic syndrome could extenuate markedly the recurrence rate of disease and the side-effect of CS reduction.

Adolescent↗

PubMed2000

[Supracricoid subtotal laryngectomy for the treatment of advanced laryngeal cancers].

OBJECTIVE: This procedure was designed to eradicate the advanced laryngeal carcinomas while preserving the laryngeal physiologic function. The indications and contraindications for the operation were also discussed and evaluated in this paper. METHODS: Twenty-one patients with advanced laryngeal cancers underwent this procedure during the period from 1988 through 1996 in our department. All of the patients were not amenable to conventional partial horizontal and vertical laryngectomies. In those patients, there were 9 supraglottic cancers, 10 glottic cancers and 2 transglottic cancers. Among them, 16 cases had stage T2 lesions and 5 cases had stage T3 lesions. In this procedure, the hyoid and thyroid cartilages were excised in toto, along with both true and false vocal cords, paraglottic space as well as the partial or total epiglottis and the whole preepiglottic space. The cricoid cartilage and at least one arytenoid cartilage were spared. The new larynx was reconstructed by suturing the cricoid and/or epiglottis to the base of the tongue. RESULTS: Of 21 patients, 95% were able to eat normally without aspiration, 90% were decannulated with near normal speech function. In two patients, the tracheotomy tube was reserved, one developed a stenosis, and another had recurrent aspiration pneumonia. No patients experienced local recurrence. Nineteen patients were followed up for at least 3 years, 13 patients achieved 5 years tumor-free survival. CONCLUSION: The term supracricoid subtotal laryngectomy best describes the surgical approach and the reconstruction model of the new larynx. As a useful alternative to total laryngectomy in selected advanced laryngeal cancers, this procedure may greatly improve the quality of life and prolong the life without recurrence.

Adult↗

PubMed1999

The radial pattern of basilar membrane motion evoked by electric stimulation of the cochlea.

Electric current applied to the cochlea can evoke in situ electromotile responses of the organ of Corti. These nonsound-generated responses can give insight into the mechanics of the organ as the putative forces produced by outer hair cells (OHC) must couple to the modes of vibration of the basilar membrane (BM). In this study, platinum-iridium wire electrodes were positioned into the scala vestibuli and scala tympani of the first cochlear turn in the guinea pig. Current (1.5 ms rectangular-shaped pulses) was applied to these electrodes at levels to 500 microA peak. A laser Doppler velocimeter was used to record the velocity or displacement of the basilar membrane at the tonotopic 18 kHz place via an opening into the scala tympani of the first cochlear turn. Beads were positioned across the width of the BM so that the velocity or displacement of the BM could be studied in the radial direction. It was found that the current pulses evoked linear displacements of up to 2 nm for current levels of 500 microA (higher levels were damaging to the organ of Corti). The pattern of motion across the width of the BM was such that maximum displacement and velocity was located near the first row of OHCs and the position of the outer pillar cell footplate. The BM motion was biphasic in that the zona arcuata moved in the opposite direction to that of the zona pectinata. The results of this study demonstrate that the level of force produced by OHCs is effective in moving the BM and that the distribution of force within the organ of Corti leads to a multimodal motion pattern of the BM for this experimentally artificial means of evoking OHC motion.

Animals↗

PubMed1999

Cell proliferation and apoptosis.

Cell proliferation and cell death are essential yet opposing cellular processes. Crosstalk between these processes promotes a balance between proliferation and death, and it limits the growth and survival of cells with oncogenic mutations. New insights into the mechanisms by which strong signals to proliferate and activation of cyclin-dependent kinases promote apoptosis have recently been published, and a novel cell cycle regulated caspase inhibitor, Survivin, has been described.

Animals↗

PubMed1999

Immunohistochemical detection of breast cancer cells in paired peripheral blood progenitor cell specimens collected after cytokine or cytokine and myelosuppressive chemotherapy.

Mobilized peripheral blood progenitor cells (PBPC) from 30 patients with advanced breast cancer were studied for the presence of tumor cell contamination using a highly sensitive immunohistochemical technique with the capacity to detect one tumor cell in one million mononuclear cells. Aliquots of PBPC were obtained after 4 days of G-CSF and/or GM-CSF and again during G-CSF-stimulated recovery from myelosuppressive doses of cyclophosphamide. The overall incidence of tumor cell contamination was 23%, occurring in PBPC specimens from seven of 30 patients. All four cases in which tumor cells were detected after mobilization with cytokine alone also had tumor cells detected in PBPCs collected following chemotherapy and G-CSF. There were three cases in which malignant contamination was detected only in the specimens collected after cyclophosphamide. There was a greater frequency of tumor cell contamination in aphereses performed during G-CSF-stimulated recovery from cyclophosphamide than in collections primed by cytokine alone (13% vs 23%; P = 0.08), although this did not reach statistical significance. This trend suggests that collection of PBPC during cytokine-stimulated recovery from myelosuppressive chemotherapy may be associated with a greater risk of contamination with malignant cells than apheresis during mobilization with cytokines in the steady state.

Adult↗

PubMed1999

Ex-vivo expansion of CFU-GM and BFU-E in unselected PBMC cultures with Flt3L is enhanced by autologous plasma.

BACKGROUND: Previous ex-vivo expansion studies in our laboratory, comparing unselected and CD34(+)-selected PBMC, have shown no advantage for CD34(+) cell selection, in terms of the expansion achieved. Our goal was to develop procedures for consistent generation of large numbers of hematopoietic progenitor and post-progenitor cells from unselected PBMC. METHODS: Unselected PBMC, collected from cancer patients undergoing apheresis prior to high-dose chemotherapy and autologous stem cell rescue, were expanded ex vivo in static cultures, without a stromal layer, in the presence of Flt3 ligand (Flt3L), a recombinant GM-CSF/IL-3 fusion protein (PIXY321), G-CSF and GM-CSF for 10 days. RESULTS: The addition of 2% autologous plasma to this cytokine combination enhanced expansion of total cell numbers (3.2 fold versus 1.9 fold; p < 0.01), colony-forming units granulocyte-macrophage (CFU-GM) (22.0 fold versus 8.1 fold, p < 0.01) and burst-forming units erythroid (BFU-E) (17.6 fold versus 7.0 fold, 0.01 < p < 0.02). The optimal seeding density for a given specimen was inversely related to the frequency of CD34(+) cells in the sample. CFU-GM expansion with the Flt3L-containing cytokine cocktail was equivalent to that obtained with IL-3, IL-6, G-CSF and SCF, whether or not the cultures were supplemented with autologous plasma. In plasma-free cultures, BFU-E expansion was significantly higher with IL-3, IL-6, G-CSF and SCF than with Flt3L, PIXY321, G-CSF and GM-CSF. In the presence of autologous plasma, however BFU-E expansion was higher in the Flt3L-containing media. In comparison studies, autologous plasma suppressed BFU-E expansion in SCF-containing cultures. Consistent with our colony assay results, dual-parameter flow cytometric analysis of the expanded cell population revealed that supplementation with autologous plasma yielded a significant increase in the numbers of myeloid progenitors in Flt3L-containing cultures. DISCUSSION: Unselected PBMC from cancer patients can be effectively expanded ex vivo in Flt3L, PIXY321, G-CSF and GM-CSF, supplemented with autologous plasma, yielding high numbers of myeloid and erythroid progenitors.

Antigens, CD34↗

PubMed1999

Basal cell carcinoma with lung metastasis diagnosed by fine-needle aspiration biopsy.

Basal cell carcinoma of the skin is one of the most common types of cancer. Its natural history is one of local recurrence rather than metastatic spread. Certain histologic features and primary tumor size seem to be risk factors for metastases. The diagnosis of metastatic disease imparts a poor prognosis with a short median survival. Treatment is usually in the form of systemic chemotherapy with cisplatin-based combination described as most active agent.

Aged↗

PubMed1999

Molecular characterization of a porcine enteric calicivirus genetically related to Sapporo-like human caliciviruses.

Porcine enteric calicivirus (PEC) is associated with diarrhea in pigs, and to date it is the only cultivable enteric calicivirus (tissue culture-adapted [TC] PEC/Cowden). Based on sequence analysis of cDNA clones and reverse transcription-PCR products, TC PEC/Cowden has an RNA genome of 7,320 bp, excluding its 3' poly(A)(+) tail. The genome is organized in two open reading frames (ORFs), similar to the organizations of the human Sapporo-like viruses (SLVs) and the lagoviruses. ORF1 encodes the polyprotein that is fused to and contiguous with the capsid protein. ORF2 at the 3' end encodes a small basic protein of 164 amino acids. Among caliciviruses, PEC has the highest amino acid sequence identities in the putative RNA polymerase (66%), 2C helicase (49.6%), 3C-like protease (43.7%), and capsid (39%) regions with the SLVs, indicating that PEC is genetically most closely related to the SLVs. The complete RNA genome of wild-type (WT) PEC/Cowden was also sequenced. Sequence comparisons revealed that the WT and TC PEC/Cowden have 100% nucleotide sequence identities in the 5' terminus, 2C helicase, ORF2, and the 3' nontranslated region. TC PEC/Cowden has one silent mutation in its protease, two amino acid changes and a silent mutation in its RNA polymerase, and five nucleotide substitutions in its capsid that result in one distant and three clustered amino acid changes and a silent mutation. These substitutions may be associated with adaptation of TC PEC/Cowden to cell culture. The cultivable PEC should be a useful model for studies of the pathogenesis, replication, and possible rescue of uncultivable human enteric caliciviruses.

Amino Acid Sequence↗

PubMed1999

Transcripts of immunoglobulin germline mu: an amplified myeloid and B-lymphoid common gene program in various leukemias.

To investigate the clinical implications of germline C mu transcription, the splice region between the 3' end of the enhancer and the first exon of immunoglobulin germline mu; was analyzed by RT-PCR in 63 samples from 59 patients with leukemia. Immunophenotypes of 33 samples from patients with acute leukemia were analyzed using a panel of these monoclonal antibodies: anti-immature/stem cell (HLA-DR, CD34); anti-mature myeloid (CD33, CD15); anti-T lymphoid (CD2, CD3, CD5, CD7, CD8), and anti-B lymphoid (CD10, CD19, CD20). Of the 63 samples, 33 (52%) contained germline C mu transcripts: 2/2 patients with chronic lymphocytic leukemia; 17/26 (65.4%) patients with acute myeloblastic leukemia; all 4 patients with chronic myelogenous leukemia in blast crisis and 1 in accelerated phase; 9/12 patients with acute lymphocytic leukemia. A clear correlation between germline transcripts and HLA-DR expression was observed among germline-positive cases (p < 0. 01). C mu expression and response to therapy clearly indicated that germline-mu-positive leukemia patients responded poorly to chemotherapy and had a worse clinical prognosis compared with C mu-negative patients (p < 0.01). After two courses of chemotherapy, 7/9 C mu-negative patients achieved complete remission compared to only 7/29 C mu-positive patients (p < 0.01). We conclude that the gene-regulating immunoglobulin germline C mu may be amplified in myeloid and B-lymphoid cells during leukemogenesis. Such genetic changes may be correlated with cellular terminal differentiation injury, resistance to chemotherapy and uncontrolled malignant cell proliferation.

Adolescent↗

PubMed1999

Advantages of concurrent biochemotherapy modified by decrescendo interleukin-2, granulocyte colony-stimulating factor, and tamoxifen for patients with metastatic melanoma.

PURPOSE: Concurrent biochemotherapy results in high response rates but also significant toxicity in patients with metastatic melanoma. We attempted to improve its efficacy and decrease its toxicity by using decrescendo dosing of interleukin-2 (IL-2), posttreatment granulocyte colony-stimulating factor (G-CSF), and low-dose tamoxifen. PATIENTS AND METHODS: Forty-five patients with poor prognosis metastatic melanoma were treated at a community hospital inpatient oncology unit affiliated with the John Wayne Cancer Institute (Santa Monica, CA) between July 1995 and September 1997. A 5-day modified concurrent biochemotherapy regimen of dacarbazine, vinblastine, cisplatin, decrescendo IL-2, interferon alfa-2b, and tamoxifen was repeated at 21-day intervals. G-CSF was administered beginning on day 6 for 7 to 10 days. RESULTS: The overall response rate was 57% (95% confidence interval, 42% to 72%), the complete response rate was 23%, and the partial response rate was 34%. Complete remissions were achieved in an additional 11% of patients by surgical resection of residual disease after biochemotherapy. The median time to progression was 6.3 months and the median duration of survival was 11.4 months. At a maximum follow-up of 36 months (range, 10 to 36 months), 32% of patients are alive and 14% remain free of disease. Decrescendo IL-2 dosing and administration of G-CSF seemed to reduce toxicity, length of hospital stay, and readmission rates. No patient required intensive care unit monitoring, and there were no treatment-related deaths. CONCLUSION: The data from this study indicate that the modified concurrent biochemotherapy regimen reduces the toxicity of concurrent biochemotherapy with no apparent decrease in response rate in patients with poor prognosis metastatic melanoma.

Adult↗

PubMed1999

Apoptotic cell death of human gastric tumor induced by nucleosides from CD57+HLA-DRbright natural suppressor cell line.

CD57+HLA-DRbright natural suppressor (57.DR-NS) cell line derived from human decidual tissue generated apoptosis in a human gastric carcinoma cell line (GCIY) but not in a human diploid normal cell line (WI-38). The factors released from 57.DR-NS cells were purified by thin-layer-chromatography (TLC) and separated by high performance liquid chromatography (HPLC) into six components. The physicochemical structures of the six components were determined as a series of nucleosides and their modified forms collectively termed in a previous study. They could generate apoptotic cell death of GCIY malignant target cells, but not disturb the viability of WI-38 normal target cells. The administration of AINs into GCIY tumor bearing SCID mice resulted in drastic suppression of tumor growth followed by the decrease in tumor size due to the occurrence of apoptosis in tumor tissues.

Animals↗

PubMed1999

Rejoining of DNA double-strand breaks in Ku80-deficient mouse fibroblasts.

The role of Ku80 in the repair of DNA double-strand breaks (DSBs) was examined in fibroblasts derived from a Ku80 knockout mouse model described by Nussenzweig et al. (Nature 382, 551-555, 1996). Primary fibroblasts from Ku80+/+ and Ku80-/- mice were immortalized by transfection with plasmids containing either the human MYC proto-oncogene or the Simian virus 40 (SV40) T antigen and were used to measure induction and rejoining of DSBs after exposure to ionizing radiation. The number of DSBs in the cells was quantified by either asymmetric field-inversion gel electrophoresis (AFIGE) or clamped homogeneous electrical-field gel electrophoresis (CHEF). The latter method was introduced for a more reliable quantification of repair even when DNA degradation occurs in a fraction of the irradiated cell population during the postirradiation incubation time. The results confirm that Ku80-deficient mouse fibroblasts are sensitive to ionizing radiation and demonstrate that the increased radiosensitivity may result from a deficiency in DSB rejoining. The results further indicate that unless techniques are employed that allow for distinction between DNA degradation and DNA repair, erroneous conclusions may be drawn regarding the potential of cells to repair DSBs.

Animals↗

PubMed1999

[Cytogenetic analysis and bcr/abl mRNA detection in chronic myeloid leukemia].

OBJECTIVE: To define the relationship between Ph chromosome and BCR/ABL mRNA expression in chronic myeloid leukemia (CML) patients, and compare cytogenetic analysis and PCR method. METHODS: Marrow or peripheral blood samples from 33 CML patients were analyzed by R banding technique and PCR method. Eleven patients who received allogeneic BMT or alpha-IFN + low dose HU were followed up. RESULTS: In 33 patients, 29 were Ph(+), 30 expressed BCR/ABL mRNA. In 6 patients who received BMT, 4 were Ph(-), 2 were Ph(+). However, 2 patients were (-), 4 were (+) by PCR method. In 5 patients who received alpha-IFN, the percentage of Ph(+) cells reduced after 6 and 12 months treatment than before treatment in 2 cases respectively. In 41 samples, 34 cases were consistent by 2 methods. CONCLUSION: Each method, Cytogenetic analysis or PCR has its advantage and defect. The better method are integration of 2 methods in diagnosis and treatment monitoring of CML patients, so that provide real and beneficial information for clinic.

Adolescent↗

PubMed1999

[Smoking, related cancers, and other diseases in shanghai: a 10-year prospective study].

OBJECTIVE: To explore the relationship between smoking and related diseases among residents of Shanghai. METHODS: A cross-sectional study on current smoking status among 213,800 residents aged 20 yr and over in Shanghai urban, suburb and rural areas was carried out during the early 1980s. The residents in the urban area were followed up for 12 years (1983 - 1994) and those in suburb and rural areas for 11 years (1984 - 1994). A Poisson regression model was used to estimate relative risks RRs of certain diseases for smoking adjusted for age with their 95% confidence intervals by sex and area among persons aged 40 yr and over at the beginning of the study. RESULTS: In the urban area, the RRs of death for smoking were 1.48 and 1.62 in males and females, respectively and for cancer death were 2.20 and 2.00. Statistically significant elevated RRs were seen for cancers of the lung and liver in both males and females and for cancers of the oesophagus, stomach, pancreas and bladder only in males. Significantly higher RRs were also observed for cerebrovascular disease, chronic bronchitis and emphysema, and pulmonary heart disease. RRs lower than in the urban area were found in the suburb and rural areas. The population attributable risks (%, PAR) for death due to smoking for males were estimated by area. PARs for death were 20.9, 18.9 and 16.3 in urban, suburb and rural areas, respectively. For all cancers, PARs were 40.0, 34.5 and 34.2 and for lung cancer were 71.7, 59.2 and 64.7. CONCLUSION: Smoking was associated with the mortality of some common cancers, chronic bronchitis, and emphysema, pulmonary heart, and cerebrovascular diseases.

China↗