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Biomedical subjects

F Li

Publications and source records attributed to F Li.

At least 343 records · Page 19Linked to original sources
PubMed1998

Human IAP-like protein regulates programmed cell death downstream of Bcl-xL and cytochrome c.

The gene encoding human IAP-like protein (hILP) is one of several mammalian genes with sequence homology to the baculovirus inhibitor-of-apoptosis protein (iap) genes. Here we show that hILP can block apoptosis induced by a variety of extracellular stimuli, including UV light, chemotoxic drugs, and activation of the tumor necrosis factor and Fas receptors. hILP also protected against cell death induced by members of the caspase family, cysteine proteases which are thought to be the principal effectors of apoptosis. hILP and Bcl-xL were compared for their ability to affect several steps in the apoptotic pathway. Redistribution of cytochrome c from mitochondria, an early event in apoptosis, was not blocked by overexpression of hILP but was inhibited by Bcl-xL. In contrast, hILP, but not Bcl-xL, inhibited apoptosis induced by microinjection of cytochrome c. These data suggest that while Bcl-xL may control mitochondrial integrity, hILP can function downstream of mitochondrial events to inhibit apoptosis.

Apoptosis↗
PubMed1998

A double blind placebo controlled study to determine the effects of intermittent cyclical etidronate on bone mineral density in patients on long-term oral corticosteroid treatment.

BACKGROUND: A double blind, placebo controlled study was undertaken to determine the effects of 104 weeks of intermittent cyclical etidronate therapy on bone mineral density (BMD) in patients undergoing long-term oral corticosteroid therapy. METHODS: Forty nine patients of mean age 59 years on long-term (> 6 months) corticosteroid treatment were randomised to receive either 400 mg/day etidronate or placebo for 14 days followed in both groups by calcium (equivalent to 97 mg elemental Ca/day) with vitamin D (400 IU) for 76 days. The cycle was repeated a total of eight times over a period of two years. Dual energy x ray absorptiometry (DEXA) measurements of the lumbar spine and hip BMD and biochemical bone marker analyses were performed at baseline and every six months. RESULTS: Twenty six patients (10 men) received cyclical etidronate and 23 (nine men) received placebo. The mean (SD) dose of corticosteroid (prednisone or equivalent) at baseline in the etidronate group was 8 (4) mg/day and in the placebo group was 7 (4) mg/day. Most of the patients (43%) suffered from asthma. Forty one patients completed the study (22 in the etidronate group and 19 in the placebo group). All had a low BMD at entry and with treatment a significant difference was observed between groups in the mean (SE) percentage change from baseline in lumbar spine BMD at week 104 of 4.5 (1.65)% (p = 0.007) with a 95% confidence interval (CI) of 1.12 to 7.87%. No clinically or statistically significant treatment differences were observed at the hip or with bone markers. The incidence of adverse events was similar in the two groups. CONCLUSIONS: The results show that intermittent cyclical etidronate therapy with calcium and vitamin D supplementation significantly increases lumbar spine BMD in patients with osteoporosis resulting from long-term treatment with corticosteroids.

Aged↗
PubMed1998

Localization and secretion of tissue kallikrein in peptidoglycan-induced enterocolitis in Lewis rats.

The plasma kallikrein-kinin system is a mediator of intestinal inflammation induced by peptidoglycan-polysaccharide from group A streptococci (PG-APS) in rats. In this study we investigated the participation of intestinal tissue kallikrein (ITK). Lewis rats were injected intramurally with PG-APS. ITK was visualized by immunohistochemical staining. Cecal ITK concentration was measured by radioimmunoassay, and gene expression was evaluated by RNase protection assay. Kallikrein-binding protein (KBP) was evaluated in plasma by ELISA. Tissue kallikrein was identified in cecal goblet cells in both control and PG-APS-injected rats and in macrophages forming granulomas in inflamed tissues. Cecal ITK was significantly lower in acute and chronic phases of inflammation and in supernatant from in vitro cultures of inflamed cecum. ITK mRNA levels were not significantly different. Plasma KBP levels were significantly reduced in inflamed rats. The presence of tissue kallikrein in macrophages suggests participation in experimental colitis. The decrease of ITK in the inflamed intestine associated with unchanged mRNA levels suggests ITK release during intestinal inflammation.

Animals↗
PubMed1998

A new method to improve in-bore middle cerebral artery occlusion in rats: demonstration with diffusion- and perfusion-weighted imaging.

BACKGROUND AND PURPOSE: In-bore middle cerebral artery occlusion (MCAO) enables investigators to acquire preischemic MRI data and to image ischemic changes immediately after occlusion. We have developed a highly successful in-bore MCAO method. This study describes the methods and pertinent techniques. METHODS: Sixty-seven Sprague-Dawley rats were subjected to temporary (n=36) or permanent (n=31) MCAO. The occluding device consisted of a supporting tubing, a driving line, and a silicone-coated 4-0 nylon suture occluder. Outside the magnet, the occluder was positioned in the carotid canal. MCAO was achieved in the magnet bore by remotely advancing the driving line until resistance was felt. Diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) were acquired before and immediately after occlusion and were used to document the presence of MCAO. RESULTS: Fifty-nine (88.1%) rats were successfully occluded, demonstrating hyperintensity on DWI, perfusion deficits on PWI, and no subarachnoid hemorrhage at postmortem examination. The average values of the apparent diffusion coefficient in both the frontoparietal cortex and the lateral caudoputamen significantly decreased as early as 3 minutes after the onset of ischemia. The failures included preocclusion damage (1/67), sliding out of the occluder during occlusion (1/67), no occlusion (2/67), and arterial perforation (4/67). CONCLUSIONS: Our in-bore MCAO method is easily performed and is as successful as MCAO induced outside the magnet.

Animals↗
PubMed1998

Second malignancies in patients treated for childhood acute lymphoblastic leukemia.

PURPOSE: Second malignant neoplasms (SMN) are devastating late complications of childhood acute lymphoblastic leukemia (ALL) and its treatment. We evaluated the incidence and type of SMN diagnosed before leukemic relapse in a large series of patients with ALL. PATIENTS AND METHODS: We reviewed the outcome of all patients treated for childhood ALL between 1972 and 1995 on Dana-Farber Cancer Institute (DFCI) and DFCI ALL Consortium protocols. The follow-up time from diagnosis of ALL to induction failure, relapse, remission death, or SMN, whichever occurred first, ranged from 0 to 24.0 years (median, 7.6 years; mean, 6.7 years). RESULTS: Thirteen SMNs were diagnosed among 1,597 patients. Eight tumors occurred in a radiation field (five in the CNS and three in the head and neck), two occurred outside of a radiation field (one adenocarcinoma of the sigmoid colon and one epithelioid sarcoma of the chest wall), and three were hematopoietic malignancies. The median time to occurrence was 6.7 years (range, 1.0 to 17.2 years) and the cumulative incidence of second malignancy before another first event was 2.7% (95% confidence interval, 0.7 to 4.7). The risk of a first event, which included induction failure, relapse, or remission death, was 31.0% (95% confidence interval, 28.5 to 33.5). CONCLUSION: We found a more than 10-fold risk of other first events when compared with SMN. Thus, we conclude that SMN before first relapse is a relatively uncommon occurrence among survivors of childhood ALL. Future therapeutic regimens must focus on reducing leukemia relapse and enhancing quality of life, as well as preventing SMNs.

Child↗
PubMed1998

Effects on brain tumor cell proliferation by an adenovirus vector that bears the interleukin-4 gene.

A recombinant adenovirus vector bearing the IL-4 gene (AD-IL-4) was used to infect rat glioma C6 cells in culture at multiplicity of infections (MOI) from 50 to 1800. C6 cell proliferation was not altered significantly by adenoviral infection. However, IL-4 production increased in a dose-dependent manner. To ascertain effects on in vivo cell proliferation, a subcutaneous tumor model was used. Rat C6 glioma cells alone or C6 mixed with the control virus bearing the LacZ gene (Ad-LacZ) produced tumors that measured an average of approximately 3000 mm3 35 days after implantation. In contrast, C6 cells mixed with Ad-IL-4 produced significant inhibition of tumor growth (P=0.035 compared to C6 tumor; P=0.023 compared to C6+Ad-LacZ tumor. Student's ttest). IL-4 levels in mice serum were measured by ELISA and reached a peak of approximately 700 pg/ml at 14 days. These preliminary results showed that adenovirus-mediated delivery of the IL-4 gene may result in a significant inhibition of rat C6 cell tumor growth. Further studies will be necessary to refine this anti-tumor effect for as a potential therapy for cancer.

Adenoviridae↗
PubMed1998

[CT diagnosis of carcinomas of ovary].

OBJECTIVES: To evaluate CT imaging feature and CT in staging of the ovarian carcinomas and low malignant potential tumors (LMP) in relation with pathology. METHODS: Preoperative CT image of of 48 tumors, including 45 carcinomas and 3 LMP in 30 patients verified surgical-pathologically were analyzed. RESULTS: The tumors were classified as cystic, predominantly cystic, mixed, predominantly solid and solid types. The solid and solid portion of the mass were enhanced obviously. It appeared flower-shaped or nodular shadows or irregularity of patch. Cystic portion of the mass with a wall or septa thickness exceeding 3mm observed wall nodularily and/or a solid mass. LMP appeared purely cystic or predominantly cystic, accompanied with a thin regular wall, thin septa and regular solid portion with contrast material uptake. CT permitted accurate estimation of the FiGo in 80% of patients. CONCLUSION: CT images is helpful to explore the pathologic appearances of neoplasms and biological characteristics of ovary carcinoma.

Adult↗
PubMed1998

[Study on the contamination level and the tolerable limit of mould and yeast in yoghurt].

The results show that 67.33% of yoghurt samples collected from factories, supermarkets and retailers are contaminated by mould and yeast. The main problem of yoghurt product is yeast contamination (56.67%). The highest count of mould and yeast in the positive samples are 39,500 cft/ml and innumerable, respectively. There is a significant difference in the levels of contamination of mould and yeast between yoghurt filled in the glass bottles and that in the plastic bottles (P < 0.005). According to the results above, it is suggested that the tolerable limit of mould and yeast in yoghurt should be equal to or less than 50 cfu/ml.

Food Microbiology↗
PubMed1998

[Data cleaning in the 1995-1996 national smoking prevalence survey].

The authors introduced the procedure of data cleaning in the 1995-1996 national smoking prevalence survey, and the objectives, principles, procedures, quality evaluation and points for attention of data cleaning were summarized. Data cleaning must be carried out from the smallest investigative unit. The logical relationship among variables must be fully considered for the revision of incorrect values. In dealing with miss values, their roles in the statistical analyses must be evaluated. Comparing the differences in some important variables before and after cleaning is a useful method for assessing whether the representativeness of the data has been changed during the cleaning process.

China↗
PubMed1998

[Applied anatomy of the vascularity in the ileocolic region and its clinical significance].

To understand the characteristics of the patterns of arteries and veins distributed over the ileocolic segment, 50 cadavers were studied by gross-anatomy. The arteries, veins and their paracolic anastomoses distributed over ileocecal region, ascending colon and transverse colon were observed. The results showed that the distribution pattern of venous vessel was far more constant than that of artery, that the arrangements of artery in the ileocolic segment were classified into 7 types, and there were no interruption of paracolic anastomoses between arteries. But in 3 specimens the paracolic anastemoses between the right colic vein and the middle colic vein were completely interrupted. These findings may be useful in guiding clinical practice and preventing postoperative complications in ileocolic replacement of esophagus.

Adult↗
PubMed1998

[Clinicopathological and immunohistochemical study of hepatoblastoma].

To investigate the relationship between immunoreaction of histologic subtype and prognosis, this paper analysed the clinicopathological data from 20 cases of hepatoblastoma. Immunohistochemical staining was performed in 18 cases. The results showed that cytopolasmic postivities of epithlial tumor cells were observed by CK, AFP, S-100 protein and vimentin in 14, 10, 9 and 4 cases respectively. Positive staining for CEA was seen in the nuclei of epithelial tumor cells in 11 cases. Nuclear P53 protein staining was found in 9 cases. Nuclear and cytoplasmic postivities of P16 protein were observed in 7 cases. S-100 protein, vimentin, CK and P16 protein were detected in mesenchymal component in 1 case. This study suggested that immunoreactions of hepatoblastomas were different in histologic subtypes. The expression may correlate with the neoplastic differentiation and prognosis.

Carcinoembryonic Antigen↗
PubMed1998

Preliminary observation on the correlation between nm23 expression and Ki-67 antigen with early metastasis of human osteosarcoma.

OBJECTIVES: To detect the nm23 expression in osteosarcoma, analyze the correlation between nm23 expression and early metastasis and to study the relation between nm23 expression with tumor differentiation and cell proliferation, as defined by Ki-67 labeling. METHODS: nm23 oncoprotein expression was measured by immunohistochemical staining using formalin fixed, paraffin embedded sections of 39 surgically resected osteosarcomas and was compared with Ki-67 expression, histological findings and early metastasis. In each sample, the grading of immunoreactivity was recorded as 0, 1+, 2+ according to the percentage of nm23 and Ki-67 labeling cells respectively. RESULTS: The cases with more than 25% positive immunoreactivity of nm23 protein were detected in 48.7% of the total cases. There was no statistical difference between nm23 expression and early metastasis, but the cases with nm23 expression appeared to have a trend to get early metastasis. nm23 expression was significantly correlated with Ki-67 expression, which was associated with differentiation of the tumor cells. CONCLUSION: The role of nm23 as a tumor metastasis suppressor in osteosarcoma is less prominent. Both nm23 and Ki-67 may help predict the possibility of early metastasis in human osteosarcomas.

Adolescent↗
PubMed1998

[Platelet-derived growth factor (PDGF) mRNA expression of porcine pulmonary artery smooth muscle cells induced by hypoxic endothelial cells conditioned medium].

OBJECTIVE: To study the effect of hypoxic endothelial cell conditioned medium on the autocrine of PDGF in porcine pulmonary artery smooth muscle cells (PASMC). METHODS: Experimental groups included serum-free medium group (control group), normoxic endothelial cell conditioned medium (NECCM) group and hypoxic endothelial cell conditioned medium (HECCM) group. The expression of PDGF-A and -B chain mRNA was determined by in situ hybridization and image analysis. RESULTS: A weak expression for PDGF-A and PDGF-B mRNA was observed in PASMC cultured in serum free medium (control group); HECCM markedly enhanced the expression of PDGF-A and PDGF-B mRNA in PASMC, both being about 1.8-fold and 1.73-fold of the control group respectively, and 1.4-fold and 1.5-fold of the NECCM group respectively (P < 0.01). CONCLUSION: PDGF may be an autocrine growth factor of PASMC induced by HECCM and may play an important role in vascular structural remodeling of hypoxic pulmonary hypertension.

Animals↗
PubMed1998

[Distortion product otoacoustic emissions in normally hearing young humans].

OBJECTIVE: To investigate the basic properties of distortion product otoacoustic emissions (DPOAE) in normally hearing subjects of China. METHODS: DPOAE "audiogram" (DP-gram) and input/output functions (I/O functions) were recorded from 24 normally hearing young humans with Celesta-503 cochlear emissions analyzer. RESULTS: The prevalence of DPOAE was 100% ranging in frequency from 500 to 8,000 Hz, with respect to the geometric means of f1 and f2 stimuli. The mean DP-gram had two peaks at about 1,000 Hz and 6,000 Hz and a dip at about 3,000 Hz. The higher amplitude of DPOAE was recorded at about 3,000 Hz when using unequal primary-tone levels (L1 > L2). The mean thresholds of DPOAE were between 25 and 40 dB SPL. The thresholds of DPOAE decreased with increasing primary-tone frequencies. The I/O slopes were higher at about peak freqencies than at other frequencies. For all the results of DPOAE in left and right ears, there were no apparent differences by statistics. CONCLUSIONS: By systematical studies of the properties of DPOAE in normally hearing ears of Chinese subjects, this paper provides basic reference data for clinical application of DPOAE.

Adolescent↗
PubMed1998

[Detecting coronary artery disease with dobutamine 99mTc-MIBI myocardial perfusion tomography].

OBJECTIVE: To assess the safety and accuracy of dobutamine stress 99mTc-MIBI perfusion tomography (DST) for detecting coronary artery disease(CAD). METHODS: Seventy nine patients with suspected CAD without previous myocardial infarction underwent DST. Forty eight of the 79 patients had coronary angiography and CAD was defined as greater than 50% reduction in diameter. RESULTS: Seventeen of 20 patients with CAD demonstrated perfusion abnormalities by DST (sensitivity 85%), 20 of 24 with normal or non-significant stenosed coronary arteries had normal scan (specificity 83.3%). All 4 patients with coronary ectasia showed abnormalities by DST. Fifty seven percent of the patients experienced some discomfort, but no serious side effects occurred. CONCLUSIONS: It shows that DST is a safe and accurate alternative to exercise stress perfusion study for detecting CAD in patients unable to perform exercise testing.

Adult↗
PubMed1998

[Antivirus effect of polysaccharides of brewer yeast in vitro].

The antivirus effect of polysaccharides of brewer yeast from yeast mud on 13 kinds of viruses including DNA and RNA virus along with their mechanisms were studied. The result showed that this effect was remarkable on the infections with poliovirus III, adenovirus III, ECHO6 virus, enterovirus 71, vesicular stomatitis virus, herpesvirus I, II, coxsackie A16 virus and coxsackie B3 virus. The polysaccharides of brewer yeast could also inhibit the development of cytopathic effect(CPE) and protect cultural cells from being infected with the above viruses.

Adenoviruses, Human↗