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Biomedical subjects

L Li

Publications and source records attributed to L Li.

At least 397 records · Page 22Linked to original sources
PubMed2001

Nitric oxide in vPAG mediates the depressor response to acupuncture in stress-induced hypertensive rats.

The hypertensive rat model was made by chronic stress of electric foot-shocks and noises. On such hypertensive rats, when anesthetized with urethane and chloralose, the electroacupuncture (EA) to bilateral "Zusanli (st.36)" acupoints for 20 min, could result in a depressor (including both systolic and diastolic pressure) and bradycardiac response as well as an attenuation in the maximum of left ventricular pressure, end diastolic pressure and +/-dp/dt. In power spectrum analysis of heart rate variability aspect, EA could increase all total variance, very low frequency component, low frequency component and the ratio of low frequency component and high frequency component. When EA with microinjection of N(omega) - Nitro- L-Arginine , a blocker of the formation of nitric oxide, into the ventral periaqueductal gray matter (vPAG), the above effects of EA were abolished or reduced significantly. The results suggest that the depressor effect of EA on stress-induced hypertensive rats might be mediated by nitric oxide in the vPAG due to activation of sympathetic inhibitory system and by attenuated cardiac activities.

Acupuncture Points↗
PubMed2001

[A diagnosis test of stress fracture during basic training set of new military recruits].

OBJECTIVE: To evaluate efficacy of stress fracture (SF) during basic training for military recruits using clinical diagnosis method. METHODS: Two hundred and eighty-eight suspected SF were checked clinically and with bone scanning as golden standard. RESULTS: Sensitivity, specificity, accuracy, positive and negative predictive value, positive and negative likelihood ratios and Youden's index of clinical diagnosis were found to be 97.5%, 61.7%, 91.7%, 92.9%, 82.9%, 2.55, 0.04 and 0.59 respectively when calculated with cases. The agreement rate between two physicians was 81.7% with kappa value 0.64. When calculated with position, the precious measures were 97.2%, 84.1%, 89.7%, 82.0%, 97.6%, 6.12, 0.03, and 0.81 respectively. The agreement rate between two physicians was 94.4% with kappa value 0.88. CONCLUSION: Efficacy reliability and agreement of clinical diagnosis for SF seemed to be satisfactory.

Diagnostic Tests, Routine↗
PubMed2001

[Expression of cell adhesion molecule (CD44V6) in thyroid tumors and its significance].

OBJECTIVE: To investigate the expression of the cell adhesion molecule (CD44V6) in thyroid tumor tissue and its relationship with the pathogenesis, development, invasiveness and metastasis of the tumor. METHODS: Immunohistochemistry was applied to examine the expression of CD44V6 in 20 specimens of tissue adjacent to carcinoma, 24 of thyroid adenoma and 64 of thyroid carcinoma (including 30 papillary carcinoma, 26 follicular carcinoma, 2 anaplastic carcinoma and 6 medullary carcinoma). All the specimens were paraffin-embedded. RESULTS: The expression of CD44V6 was observed in 14 specimens of adenomas(58.33%), and 59 of carcinoma (92.19%), but was not detected in the tissue adjacent to carcinoma. The expression of CD44V6 was significantly different between follicular epithelial carcinoma and medullary carcinoma (96.55% vs 50.0%, P < 0.01). The frequency of overexpression of CD44V6 was associated with both invasiveness and lymph node metastasis (P < 0.01), but it had no relation with age, sex and tumor size (P > 0.05). CONCLUSION: It is suggested that CD44V6 will be useful for the diagnosis of thyroid carcinoma and serves as a biological marker for local invasion and lymph node metastasis of thyroid carcinoma.

Adenocarcinoma, Follicular↗
PubMed2001

Detection of p53 gene mutations in sputum samples and their implications in the early diagnosis of lung cancer in suspicious patients.

OBJECTIVES: To evaluate the value of detecting p53 gene point mutations in sputum samples and its validity and reliability as a surveillance index in the early diagnosis of lung cancer in suspicious patients. METHODS: Sputum samples were collected from 54 cases identified as lung cancer and 114 cases identified as pulmonary benign disease. The polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was performed for the detection of point mutations at exons 5-8 of the p53 gene, and sputum smears were also used for each sample. RESULTS: The detected mutation rate of 55.56% (30/54) in the lung cancer group was significantly higher than that of 1.75% (2/114) in the control group (P < 0.001). In the lung cancer group, the sensitivity, specificity, and positive likelihood ratio (PLR) of p53 mutations as a diagnostic marker for lung cancer were 55.56%, 98.25% and 31.75%, respectively. Also, the detection rates were 35.19% (19/54) by smears and 55.56% (30/54) by PCR-SSCP-silver stain, respectively. The differences both in rate and consistency were statistically significant (P < 0.01 and P < 0.05, respectively). Moreover, statistical analysis showed no significant relations between p53 mutations and clinical parameters such as gender, smoking habits, histotypes and stages, but the detection rate of p53 mutations in older patients (> or = 60 years old) was significantly higher than that in younger patients (P = 0.02). One case with p53 mutations at exon 5 in the control group was confirmed to be squamous cell carcinoma after 4 years of follow-up. CONCLUSION: Detection of p53 gene alterations in sputum samples by PCR-SSCP-silver stain can be used as a follow-up surveillance index for the early diagnosis of lung cancer in suspicious patients.

Adult↗
PubMed2001

Identification and function of glucose transporter 1 in human mesangial cells.

OBJECTIVE: To evaluate the role of glucose transporter 1 (GLUT1) in the glucose uptake of glomerular mesangial cells. METHODS: Cultured human glomerular mesangial cells were used. The expressions of glucose transporter 1 mRNA and protein were detected with reverse transcription-polymerase chain reaction (RT-PCR), flow cytometry and immunofluorescence staining. Glucose uptake was determined with 2-deoxy-[3H]-D-glucose uptake assay. RESULTS: The expressions of GLUT1 mRNA and proteins were detected in human mesangial cells. Glucose uptake and its kinetics assay showed that GLUT1 is a functional glucose transporter in cultured human mesangial cells, and that its function could be inhibited by the specific inhibitor, Phloretin. CONCLUSION: GLUT1 is the predominant glucose transporter in human mesangial cells, which has the kinetic characteristics of high affinity and low capacity for D-glucose. This suggests that in order for mesangial cells to take up excessive quantities of glucose, as in diabetes, changes in glucose transporter expression, translocation or activity may be required.

Glomerular Mesangium↗
PubMed2001

Monocyte chemoattractant protein-1 expression in renal tissue is associated with monocyte recruitment and tubulo-interstitial lesions in patients with lupus nephritis.

OBJECTIVE: To investigate the pattern of monocyte chemoattractant prolein-1 (MCP-1) distribution in the renal interstitium and evaluate its pathogenic role in tubulo-interstitial lesions in patients with lupus nephritis, the distribution of MCP-1 in renal tissue was observed. METHODS: Eighteen female patients with biopsy-proven lupus nephritis were enrolled in this study. No intensive immunosuppresive therapy was used in these patients during the 3 months prior to renal biopsy. The distribution of MCP-1, infiltration of CD68+ (macrophage/monocyte), CD4+ and CD8+ cells in the tubulo-interstitium of patients with lupus nephritis was detected using immunohistochemical staining with specific antibodies. Renal specimens from patients with minimal change glomerulonephritis were used as controls. RESULTS: MCP-1 protein was widely distributed in the renal tissue of patients with lupus nephritis, mainly located at the baso-lateral surface of tubular epithelial cells (16/18 biopsies), and on the wall of interstitial blood vessels (9/18 biopsies). In contrast, tubular MCP-1 staining was weak and rare in renal tissue from controls (7.4 +/- 6.2% vs 26.7 +/- 22.8%, P < 0.01). Tubulo-interstitial infiltration of CD68+, CD4+ and CD8+ cells was markedly increased in patients with lupus nephritis as compared to controls. The tubular expression of MCP-1 was strongly associated with the amount of CD68+ cell infiltration in the interstitium (r = 0.5420, P < 0.05) and the extent of interstitial fibrosis. There was no correlation between MCP-1 production in tubules and the degree of urinary protein excretion in patients with lupus nephritis (r = 0.0547, P > 0.05). CONCLUSIONS: The expression of MCP-1 in the renal tubules and vascular wall was markedly increased in patients with lupus nephritis. The overproduction of MCP-1 in renal tissue may contribute to monocyte recruitment in the interstitium and thus result in tubulo-interstitial damage in lupus nephritis.

Adult↗
PubMed2001

Changes in intestinal microflora in patients with chronic severe hepatitis.

OBJECTIVE: To investigate changes in intestinal microflora in patients with chronic severe hepatitis (CSH), and their role in this life-threatening disease. METHODS: We classified nineteen patients with chronic severe hepatitis as the CSH group, thirty patients with chronic hepatitis (CH) as the CH group and thirty-one healthy volunteer as the control group. Fecal flora from all subjects were analyzed. Concentrations of plasma endotoxin, serum cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) and liver function were assessed. RESULTS: The number of fecal bifidobacterium (P < 0.001, P < 0.05 respectively), as well as bacteroidaceae (P < 0.001, P < 0.01 respectively) were significantly deceased in patients with chronic severe hepatitis compared with the CH and control groups, while the number of enterobacteriaceae (P < 0.001, P < 0.05 respectively) and yeasts (P < 0.01, P < 0.05 respectively) were significantly increased. Levels of plasma endotoxin, serum TNF-alpha, IL-1 beta and total bilirubin (TBiL) were significantly increased in the CSH group. The concentration of endotoxin positively correlated with levels of both TNF-alpha, IL-1 beta and TBiL (P < 0.001, respectively). Levels of plasma endotoxin were positively correlated with the number of fecal enterobacteriaceae and negatively correlated with bifidobacterium (P < 0.05, P < 0.001, respectively). CONCLUSION: Intestinal flora in patients with chronic severe hepatitis were severely disturbed and gut microbiological colonization resistance was impaired. Changes in intestinal flora may have a pivotal role in both the elevation of plasma endotoxin and further hepatic lesions resulting in liver failure.

Adult↗
PubMed2001

Treatment of hepatic failure with artificial liver support system.

OBJECTIVE: To assess the effectiveness of artificial liver support system (ALSS) treatment in patients with hepatic failure. METHODS: 235 cases of hepatic failure were treated with ALSS in our hospital. All data were analyzed by SPSS. The effectiveness of ALSS treatment was compared according to different stages (i.e., early, middle and end stages). RESULTS: 108 patients survived after therapy of ALSS. After each ALSS treatment, the liver function of these patients was greatly improved, the serum endotoxin and HBV-DNA concentrations were significantly decreased, and the serum concentration of aromatic amino acids (AAA) such as methionine decreased while the ratio of branched chain amino acids and aromatic amino acids (BCAA/AAA ratio) increased; patients treated with ALSS in the early or middle stages of disease had much higher survival rates than patients in the end stage of disease. CONCLUSION: ALSS is a reliable therapy for advanced liver diseases and treatment at early or middle stages is appropriate.

Adult↗
PubMed2001

Expression and function of c-kit receptor in bone marrow mononuclear cells of patients with myelodysplastic syndromes.

OBJECTIVE: To determine the expression and function of the c-kit receptor in bone marrow mononuclear cells (BMMNC) of patients with myelodysplastic syndromes (MDS). METHODS: Direct immunofluorescence assay and reverse transcriptase-polymerase chain reaction (RT-PCR) were used to detect c-kit protein and c-kit mRNA expressions in the BMMNC of 29 MDS patients and 10 normal controls. Cell culture was used to detect the function of the c-kit receptor. RESULTS: c-kit protein expression in the MDS group was significantly higher than that in the control group (8.58% +/- 5.28% vs 3.04% +/- 1.49%, P < 0.05). c-kit protein expression in the refractory anemia (RA) group was significantly lower than that in the RA with an excess of blasts (RAEB)/RAEB in transformation (RAEB-t) group (5.12% +/- 2.13% vs 10.01% +/- 5.07%, P < 0.05). The rate of c-kit protein expression was 32.43% in acute myeloblastic leukemia (AML) cases transformed from MDS (t-AML). c-kit mRNA expression in the MDS group was correlated with c-kit protein expression. Interleukin-3 (IL-3) and erythropoietin (Epo), with or without stem cell factor (SCF), upregulated c-kit protein and its mRNA expression. In the presence of IL-3 and Epo, SCF showed significant stimulating effects on the formation of CFU-GM and BFU-E in semi-solid cultures of normal BMMNC, but had no effects on those of the MDS patients. CONCLUSION: The protein and mRNA expression of the c-kit receptor in the BMMNC of MDS patients were higher than those of normal controls, and the function of this receptor in MDS BMMNC was abnormal.

Bone Marrow Cells↗
PubMed2001

Investigation of infection risk and the value of urine endotoxin during extracorporeal shock wave lithotripsy.

OBJECTIVE: To clarify the infection risks and the value of endotoxin determination in urine during extracorporeal shock wave lithotripsy (ESWL). METHODS: According to the distribution and complications of upper urinary calculi, 164 patients were divided into five groups. Group A consisted of 48 patients with 1 to 4 renal calculi, which were or less than 2 cm in diameter. Group B was composed of 24 patients with renal calculus larger than 2 cm in diameter or one to multiple renal calculi. Group C was composed of 22 patients with 1 to 3 renal calculi accompanied by 1 to 2 ureteric calculi. Group D consisted of 51 patients with 1 to 3 ureteric calculi that were 0.5 to 1.2 cm in diameter, respectively. Group E included 19 patients with complicated renal calculus, such as casting and staghorn renal calculus. Urine and blood samples of these patients were obtained before and after ESWL, respectively. Their urine samples were proven sterile prior to treatment. All samples were cultured for bacteria and investigated for endotoxin concentration by the limulus lysate test. RESULTS: No significant difference in serum endotoxin was noted before and after ESWL. Blood bacterial cultures were all negative in all patients after ESWL, similar to those before ESWL. Significant increases in urine endotoxin after ESWL compared with that before ESWL in patients of Groups B, C and E were observed, respectively (P < 0.05). There was no significant difference in urine endotoxin after ESWL compared with that before ESWL in patients of Groups A and D. The positive incidences of urine bacterial culture were significantly increased (P < 0.05) in Groups B and C and very significantly increased (P < 0.01) in Group E compared with those in Groups A and D. CONCLUSIONS: Urinary infection risk following ESWL was lower in patients with one to several renal calculi, which were less than 2 cm in diameter and did not interfere obviously with the urine flow or in patients with 1 to 3 ureteric calculi that were 0.5 to 1.2 cm in diameter. The risk was higher in those with complicated calculi, such as casting, staghorn renal calculus, renal calculus larger than 2 cm in diameter or renal calculi accompanied by ureteric calculi. For patients with higher infection risk after ESWL, prophylactic antibiotics are necessary even if bacteriuria is not present before ESWL. Endotoxin determination in urine is a reliable, sensitive and simple method for the diagnosis of bacterial infection in patients undergoing ESWL.

Adolescent↗
PubMed2001

An epidemiological survey on neonatal jaundice in China.

OBJECTIVE: To provide epidemiological data for revising the diagnostic criteria of neonatal hyperbilirubinemia in China. METHODS: A survey was performed among full-term infants in multiple centers throughout the country. From less than 24 hours after birth, the infants' bilirubin levels were measured every day until the peak level fell to less than 68.4 mumol/L. Auditory brainstem responses were assessed in 56 infants randomly chosen from those with serum bilirubin levels of higher than 220.5 mumol/L. RESULTS: Jaundice in most infants was detected at 2-3 days after birth. The bilirubin level usually reached a peak level of 204 +/- 54.69 mumol/L at 5 days after birth and then fell. Among the 875 infants, the serum bilirubin levels in 34.4% of neonates were higher than 220.5 mumol/L. The mean serum bilirubin level of the infants during the first week after birth varied with geography (P < 0.001) and season (P < 0.001). The serum bilirubin level was significantly associated with gestation age (P < 0.01), delivery method (P < 0.01), weight loss (P < 0.001), and PCV elevation (P < 0.001) during the first three days after birth. CONCLUSIONS: The start time of neonatal jaundice was similar to that reported elsewhere, but the mean peak level in our study was higher than the reported. It is suggested that the diagnostic criteria for neonatal hyperbilirubinemia in China should be strict.

Bilirubin↗
PubMed2001

The clinical and pathological characteristics of Chinese patients with pauci-immune crescent glomerulonephritis.

OBJECTIVE: To investigate the clinical and pathological characteristics of pauci-immune crescent glomerulonephritis (PICGN) in Chinese patients. METHODS: During 13 years (1985-1998), 6400 patients underwent non-transplanting renal biopsy. Twenty-four patients were diagnosed as PICGN. All clinical and laboratory data of these patients were collected from the patients' records and used for detailed analysis. The diagnosis is based on clinicopathologic findings. RESULTS: Of the 24 patients, 16 were females and 8 were males, with median age of 33 years (ranged 10-76 years). Microscopic polyarteritis (MPA) (33.3%) and systemic vasculitis (8.3%) were the secondary diseases. The incidence of PICGN was 0.38% in renal biopsies and 22.9% in crescentic glomerulonephritis. Clinically, most patients (75.0%) showed rapidly progressive nephritis with enlarged kidneys. At onset, gross hematuria was noted in 58.3% of patients, hypertension in 45.8%, nephrotic syndrome in 41.7%, and oliguria in 25.0%. However, systemic symptoms were rare except for anemia. Pathologically, necrosis of glomerular capillaries (62.5%), infiltration of monocytes and neutrophil cells in glomeruli (66.7%), and vasculitis in the interstitium (53.3%) were observed. In addition, glomerulosclerosis was noted in 45.8%, severe tubular atrophy in 83.3% and interstitial fibrosis in 75.0%. Anti-neutrophil cytoplasmic antibodies (ANCAs) were positive in 52.2%. All patients except two received intensively immunosuppressive therapy. Sixteen patients were available for long-term follow up (median 29.8 months, range 8-92 months). Twelve of them had life-sustaining renal function, four had normal serum creatinine (< 124 mumol/L) and only 4 patients were dialysis-dependent. CONCLUSION: PICGN is not rare in China. Early diagnosis and administration of immunosuppressive therapy, particularly in patients with rapidly progressive glomerulonephritis (RPGN), are important for good prognosis.

Adolescent↗
PubMed2001

[Study on the intestinal microbial colonization resistance in patients with chronic severe hepatitis].

OBJECTIVE: To investigate the changes of microbial colonization resistance of the bowel in patients with chronic severe hepatitis. METHODS: The fecal flora bifidobacteria, enterobacteriaceae, enterococci, and yeasts of subjects (chronic severe hepatitis, chronic hepatitis, and healthy volunteers) were quantitatively and qualitatively analyzed by Mitsuoka's methods. While the ratio of bifidobacterium to enterobacteriaceae ( B/E ratio ) was calculated. RESULTS: The number of bifidobacteria and the B/E ratio in chronic severe hepatitis group was significantly deceased compared with that of the control group (P<0.001). The number of enterobacteriaceae and yeasts was significantly increased compared with that of control group (P<0.001 and P<0.01, respectively). CONCLUSIONS: The results suggest that the intestinal microbial colonization resistance in patients with chronic severe hepatitis is seriously impaired.

Bifidobacterium↗
PubMed2001

[Expression and function of protein kinase C-alpha and beta I isoenzymes in drug-resistant gastric cancer cells].

OBJECTIVE: To study the expression and function of PKC-alpha and beta I isoenzymes in drug-resistant cells of gastric cancer. METHODS: Two tumor cell lines were used in the study: gastric cancer SGC7901 and its drug-resistant counterpart SGC7901/VCR stepwise-selected by various concentrations of vincristine. The expression of PKC-alpha and beta I isoenzymes in SGC7901 and SGC7901/VCR was detected by immunohistochemistry, laser confocal scanning microscopy and Western blot. The effects of anti-PKC-alpha or beta I antibody on adriamycin accumulation in SGC7901/VCR cells were determined by flow cytometric analysis. RESULTS: SGC7901 cells exhibited positive staining of PKC-alpha. The staining of PKC-alpha in SGC7901/VCR was stronger than that in SGC7901 cells. The higher the concentrations of vincristine, the stronger staining of PKC-alpha was observed on SGC7901/VCR cells. Both SGC7901 and SGC7901/VCR cells were positive for PKC-beta I, but without difference in staining intensity. Comparing with SGC7901, SGC7901/VCR cells showed decreased adriamycin accumulation; the decrease was more marked with the increase in concentrations of vincristine for selection of cells. Increased adriamycin accumulation in SGC7901/VCR was observed when co-incubated with anti-PKC-alpha but not anti-PKC-beta I antibodies. CONCLUSION: PKC-alpha may play a role in multidrug resistance of gastric cancer cells SGC7901/VCR.

Blotting, Western↗
PubMed2001

[Immunoelectron microscopic analysis of P-glycoprotein, p53, and Bcl-2 proteins expressions in lung cancer].

OBJECTIVE: To determine the ultrastructural localization of P-gp, p53 protein, and Bcl-2 protein in lung cancer cells, their relation to multidrug resistance and possible mechanisms of action. METHODS: Expression of P-gp, p53, and Bcl-2 proteins was examined in 8 NSCLC surgical specimens and 7 SCLC bronchoscopically biopsied specimens using postembedding PAG immunolabelling technique for electron microscopy. RESULTS: P-gp was detected on the cell membrane and the periphery of endoplasmic reticulum (ER). P53 protein was observed not only in the nuclei associated with heterochromatin but also in the cytosol. Bcl-2 protein immunoreactivity was associated with mitochondria and ER. P-gp, p53, and Bcl-2 were detected in 5(33%), 9(60%), and 4 (26.7%) out of the 15 samples examined, respectively. In 8 normal lung tissues, these three proteins were detected. Of 5 P-gp positive samples 4 were NSCLC, only 1 was SCLC after chemotherapy. CONCLUSION: P-gp, p53, and Bcl-2 proteins are detectable immuno-electron microscopically in lung cancer cells. No correlation in expression existed between of p53 and P-gp, nor did that between p53 and Bcl-2. The plasma membrane localization of P-gp supports its action as a transmembrane drug efflux pump. P-gp may play a role in MDR in lung cancer.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

[Comparative study on liquid-based cytology for cervical carcinoma screening in a high-risk area of China].

OBJECTIVE: To evaluate the efficacy of liquid-based cytology (ThinPrep Pap Test) for cervical carcinoma screening in a high incidence area, Xiangyuan county of Shanxi province. METHODS: This study was performed on 1997 women residing in Xiangyuan county, a high incidence of cervical carcinoma. Exfoliative cervical samples and subsequent colposcopic biopsies were taken from all subjects. Cervical samples were collected into a liquid buffer for both ThinPrep Pap Test cytologic screening and human papilloma virus (HPV) DNA test. All tests were carried out independently and blindly of which the results were compared with those of HPV DNA detection and colposcopic biopsies. RESULTS: When the cytologic diagnosis of atypical squamous cells of determined significance (ASCUS) was taken as the detection threshold and compared with the "standard" biopsy, the ThinPrep slides were able to detect 100%(12/12) of squamous cell carcinoma (SCC) and 93.2% high grade squamous intraepithelial lesions (HSIL) which included 96.8% (30/31) CIN III, 90.7% (39/43) CIN II and 72.4%(92/127) low grade squamous intraepithelial lesions (LSIL). When cytologic diagnosis of HSIL was used as the detection threshold, the ThinPrep slides were able to detect 100% (12/12) SCC and 87%(27/31) CIN III. CONCLUSION: Cervical specimens collected into a liquid buffer are suitable for both cytologic screening and human papilloma virus test. The ThinPrep cytology demonstrates a high sensitivity for the detection of high grade squamous intraepithelial lesions and squamous cell carcinoma.

Carcinoma, Squamous Cell↗
PubMed2001

[To select and measure the biomechanical properties of bone of rat].

In the experimental studies designed to evaluate the effects of different factors on the biomechanical properties of bone, careful selection of rats and the scientific indices is very important. The aim of this paper is to recommend some essential methods for testing and calculating the biomechanical properties of rat bone such as tension, compression, bending and torsion.

Algorithms↗