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Biomedical subjects

J Lu

Publications and source records attributed to J Lu.

At least 541 records · Page 30Linked to original sources
PubMed1995

Subcellular localization of the alpha and beta subunits of the acute myeloid leukemia-linked transcription factor PEBP2/CBF.

Each of the two human genes encoding the alpha and beta subunits of a heterodimeric transcription factor, PEBP2, has been found at the breakpoints of two characteristic chromosome translocations associated with acute myeloid leukemia, suggesting that they are candidate proto-oncogenes. Polyclonal antibodies against the alpha and beta subunits of PEBP2 were raised in rabbits and hamsters. Immunofluorescence labeling of NIH 3T3 cells transfected with PEBP2 alpha and -beta cDNAs revealed that the full-size alpha A1 and alpha B1 proteins, the products of two related but distinct genes, are located in the nucleus, while the beta subunit is localized to the cytoplasm. Deletion analysis demonstrated that there are two regions in alpha A1 responsible for nuclear accumulation of the protein: one mapped in the region between amino acids 221 and 513, and the other mapped in the Runt domain (amino acids 94 to 221) harboring the DNA-binding and the heterodimerizing activities. When the full-size alpha A1 and beta proteins are coexpressed in a single cell, the former is present in the nucleus and the latter still remains in the cytoplasm. However, the N- or C-terminally truncated alpha A1 proteins devoid of the region upstream or downstream of the Runt domain colocalized with the beta protein in the nucleus. In these cases, the beta protein appeared to be translocated into the nucleus passively by binding to alpha A1. The chimeric protein containing the beta protein at the N-terminal region generated as a result of the inversion of chromosome 16 colocalized with alpha A1 to the nucleus more readily than the normal beta protein. The implications of these results in relation to leukemogenesis are discussed.

3T3 Cells↗
PubMed1995

[Portal vein supply and embolization therapy for hepatocellular carcinoma].

To prove the necessity and feasibility of portal vein embolization for the treatment of hepatocellular carcinoma (HCC), We observed the tumor vascularity and portal vein supply by vascular casting, Doppler pulse sonography and iodized oil embolization in 178 HCC noduls. Portal vascularity was found in 75.6% of noduls (34/45). In few noduls, which were smaller than 3cm in diameter, portal branches existed only without hepatic artery branches (7/35). Tumor portal blood supply was measured in 54.1% of noduls (59/109) by using Dopplar sonography. Portal tumor branch embolization was performed in 24 of patients with unreseatable HCC, all tumor noduls being filled with iodized oil. The combined portal vein and hepatic artery embolization was more effective than hepatic artery embolization in the control of the disease (P < 0.01).

Adult↗
PubMed1995

[Epidemiology of adult diabetes mellitus in a population of Capital Iron and Steel Company in Beijing].

To prevent the development of DM in susceptible individuals, 29859 subjects, aged from 30 to 64 years, from 32 units of the Company were studied by using WHO protocal and diagnostic criteria. The results showed that the average prevalence of DM and IGT was 3.63% and 4.19% respectively, standardized by census 1990 in Beijing, and it was increased with age. No sex difference in the prevalence of DM was found, but the prevalence of IGT was higher in females (5.55%) than in males. The obesity, overweight, positive DM family history and giant baby history, as well as high daily intake of protein were closely related to the prevalence of the disease. Smoking was in effective.

Adult↗
PubMed1995

[Androgen receptors and effects of sex hormones on growth of a human ovarian carcinoma cell line].

Previous study had showed that ovarian carcinoma cell line (HO-8910 cells) contained estrogen receptors (ER) and progesterone receptors (PR). In this experiment, androgen receptors (AR) in these cells were determined by a whole cell binding assay with a synthetic nonmetabolizable androgen-methyltrienolone (3H-R1881). The results showed that there existed high affinity and low capacity, specific binding sites for 3H-R1881 in these cells, the apparent maximum binding capacity and dissociation constant of these binding sites revealed by scathchard analysis being 6.52 fmol/10(6) cells and 2.96 nmol/L respectively, indicating the presence of AR in addition to ER and PR in HO-8910 cells. Furthermore, the effects of sex hormones, i.e., estrodiol, progesterone and testosterone on the growth of HO-8910 cells were also investigated. The results showed that testosterone at 10 nmol/L slightly increased the number of HO-8910 cells, but the increase was not dose-dependent and not statistically significant. Estrodiol and progesterone had no growth-stimulatary or inhibitary effects on these cells.

Cell Division↗
PubMed1995

[Immuno histochemical study of endothelin-1 in breast cancer].

Endothelin-1 (ET-1) content was measured in tissue sections from 42 human breast cancer from grade 1 to grade III and from 8 normal breast tissue by immunohistochemistry and image analysis methods. The ET-1 was stained as brownish grains localized in the cytoplasm of tumor cells and normal breast epithelial cells. However, both the proportion of ET-1 positive cells and ET-1 cellular content were significantly higher in cancer cells than in normal breast epithelium. Moreover, the ET-1 content in the tumor cells was inversely correlated with the degree of tumor cell differentiation. It is suggested that ET-1 is synthesized by human breast cancer and its over expression may induce an abnormal proliferation of breast tissue and result in malignant growth.

Adult↗
PubMed1995

[Clinicopathologic features and diagnosis of mixed type hepatocellular carcinoma].

Hepatoma cases (n = 130) were analyzed by means of histochemical and immunohistochemical stainings. There were 99 cases of hepatocellular carcinoma (HCC), 15 cholangiocarcinoma (CC), and 16 combined HCC and CC (HCC+CC). The clinical features and the cases accompanied with hepatitis and/or liver cirrhosis in the non-tumor liver tissue of HCC+CC cases were intermediate between HCC and CC cases. Histologically, in HCC+CC cases, there were 4 cases with trabecular, 4 with pseudoglandular, 3 with solid type. In these 11 cases, the CC occupied less than 10% of the neoplasm. These cases were designated as HCC+CC type I. There was no obvious stromal fibrosis. The rest 5 cases of HCC+CC cases showed tubular carcinoma in which the CC occupied more than 10% of the tumor. These cases were designated as HCC+CC type II. There was significant fibrosis in the stroma. In all HCC+CC cases only the CC region was positive for mucin and EMA staining. Nearly 70% of the HCC+CC cases had intracytoplasmic glycogen in the HCC area. Transition areas between HCC and CC in both type I and type II HCC+CC cases were observed and they were mucin negative but EMA positive. In conclusion, HCC+CC has both HCC and CC regions with the characteristics of HCC and CC, respectively. Histochemical mucin staining and immunohistochemical EMA staining are helpful in the detection and diagnosis of the HCC+CC.

Adult↗
PubMed1995

[Iron overload and iron deficiency regulate ED1 and ED2 expression in spleen macrophages of rats].

Monoclonal antibodies ED1 and ED2 can recognize epitopes on the spleen macrophage related with its antigen presenting activity. Immunohistochemical and histochemical methods were used to show the influence of iron overload and iron deficiency on the expression of ED1, ED2 and phagocytic functions of the macrophages in the spleen. We found that iron overloaded rats had large amounts of hemosiderin deposits in the macrophages of red and white pulp with reduced expression of ED1, ED2 and phagocytic function. It is suggested that iron concentration can regulate the expression of ED1, ED2 and phagocytic activity of the macrophage, which may in turn influence its antigen presentation and anti-infection functions.

Animals↗
PubMed1995

[Transferrin receptor and iron deposition pattern in the hepatic lobules of the iron-deficient and iron-overloaded rats].

Wistar rats were made iron deficient by a low iron regimen. Iron overload was produced by repeated intraperitoneal injections of ferric nitrilotriacetate (Fe(3+)-NTA) for one to four months. Hepatic tissues from these iron deficient, overloaded and control rats were examined for transferrin receptor (TfR), transferrin (Tf) and iron after immunohistochemical staining. TfR and Tf were mainly distributed in the peripheral part of the lobule (zone 1) in the normal, iron deficient and iron-overloaded rats. The staining intensity decreased from zone 1 to zone 3. The staining intensity of TfR was strongest in iron-deficiency rat hepatic cells, weakest in iron-overloaded rat hepatic cells when compared with controls. The difference of Tf staining between the three groups of rats was similar to that of TfR. In the iron-overloaded rats, the staining intensity of iron was stronger in zone 1 than in zone 2 and 3, similar to the distribution pattern of TfR and Tf. These findings suggest that (1) iron uptake in hepatic cells in vivo is regulated and mediated by TfR and Tf, (2) the expression pattern of TfR and Tf in zone 1 to zone 3 liver cells may result in the progressive decrease of iron deposition in the hepatic lobules of the iron overloaded rats.

Anemia, Iron-Deficiency↗
PubMed1995

ESR study on calcineurin.

X-band electron spin resonance spectroscopy was used to investigate the binding of Mn2+ to the apo-forms of calcineurin and its A and B subunits. The results indicated the presence of 2 Mn2+ binding sites of different affinities (20 mumol/L and 60 mumol/L) in the calcineurin A subunit and 4 Mn2+ binding sites in the calcineurin subunit B, 2 high affinity and 2 low affinity binding sites with Kd's of 4 mumol/L and 90 mumol/L, respectively. Interestingly and quite surprisingly, Mn2+ binding to the holoenzyme was characterized by only 2 binding sites with Kd's of 7 mumol/L and 33 mumol/L. However, in the presence of calmodulin about 10 Mn2+ sites were detected, and the Mn2+ calmodulin-calcineurin complex exhibited enzymatic activity. These results, based on direct spectral measurements of the metal ligand, demostrate that Mn2+ binds to both free subunits of calcineurin in a manner distinct from binding to the holoenzyme. Also, the data suggest that conformational changes occur upon heterodimer formation and association of the holoenzyme with the regulatory protein calmodulin.

Animals↗
PubMed1995

[Dynamic changes of the platelet granule membrane glycoprotein level in patients with acute myocardial infarction before and after thrombolysis].

Platelet granule membrane glycoprotein (GMP-140) level was measured by using 125I labelled monoclonal antibody in 37 patients with acute myocardial infarction before and after thrombolytic therapy. In a nonthrombolysis group, it was shown that platelet GMP-140 increased significantly at the moment of admission and reached peak value 48 hours after AMI attack, then it decreased gradually and returned to baseline on the fifth day. In the thrombolysis group, with the patency of infarct related arteries, it dropped quickly (1-6 hours) after thrombolytic therapy; if the infarct related arteries were not patent, platelet GMP-140 increased rapidly after thrombolytic therapy and reached the highest at 6 hours, then it returned to baseline on the third day. It is suggested that the changes of platelet function could play an important role in thrombus formation and lysis; the rapid decrease of the number of GMP-140 molecules on platelet surface might be a new index for the pateacy of infarct related arteries.

Adult↗
PubMed1995

[A study on serum soluble interleukin-2 receptor level in the diagnosis of acute rejection in renal transplantation].

A total of 114 samples of serum soluble interleukin-2 receptor levels (sIL-2R) were dynamicly measured with enzyme linked immunosorbent assay (ELISA) in 24 patients with renal allografts. Serum sIL-2R levels in patients with uremia were evidently higher than those in normal control group and it was markedly reduced after recovery of allograft function. The elevation of serum sIL-2R was evident in acute rejection episode and was found as early as 3-8 days before elevation of serum creatinine. Patients with cyclosporine nephrotoxicity, acute tubular necrosis and stable renal function without rejection did not have a comparable rise in sIL-2R. These data show that the level of serum sIL-2R is regarded as an important parameter for the early diagnosis of acute rejection episode. It was noted that pre-operation level of serum sIL-2R in uremic patients may foretell the possible occurrence of acute rejection episode and the prognosis after renal transplantation. It was specially emphasized that serial assay with change of sIL-2R level and comparison of the level with that before transplantation are more important than a single serum sIL-2R level assay for the early diagnosis and differential diagnosis of acute rejection.

Acute Disease↗
PubMed1995

Expression and upregulation of transferrin receptors and iron uptake in the epiplexus cells of different aged rats injected with lipopolysaccharide and interferon-gamma.

The expression of transferrin receptors marked by the monoclonal antibody OX-26 and localisation of iron was studied in epiplexus cells in the lateral ventricles of different aged rats subjected to the challenge of the bacterial toxin, lipopolysaccharide, and treatment with interferon-gamma. Transferrin receptor expression in epiplexus cells was extremely low in normal rats, but was vigorously elevated in rats receiving intraperitoneal injections of lipopolysaccharide (LPS); other antigens such as complement type 3 receptors immunostained with OX-42 and macrophage antigen marked by ED-1 were also notably augmented. After 6 successive intraperitoneal injections of interferon-gamma, the expression of transferrin receptors showed only a moderate increase. Using Perls' staining method, some iron-containing epiplexus cells were observed in early normal postnatal rats, but their number was markedly decreased with age. After LPS administration, a moderate increase in the number of iron-containing epiplexus cells was observed in different aged rats. The significance of the upregulation and vigorous expression of transferrin receptors on epiplexus cells is speculative. One possible explanation would be that they facilitate an increase in the acquisition of iron by these cells for storage, oxidative killing and/or immunological activation. The localisation of iron in the choroid plexus in the lateral ventricles suggests that the latter may function as an important storage organ for iron. Present results also suggest the presence of an efficient transport system for the transfer of iron across the interface of the blood and cerebrospinal fluid.

Aging↗
PubMed1995

[Chemical constituents of Euphorbia hylonoma Hand. -Mazz].

Three compounds have been isolated from the root of Euphorbia hylonoma and identified as 3,3',4-tri-O- methylellagic acid, beta-sitosterol and sucrose by physicochemical and spectroscopic methods. The compound 3,3'4-tri-O-methylellagic acid is discovered in Euphorbia for the first time.

Drugs, Chinese Herbal↗
PubMed1995

[High efficiency expression of IL-4 using modified cDNA expression vector in mammalian cells].

In order to express eukaryotic gene in eukaryotic cells, a cDNA library was constructed and screened with synthesized probe of IL-4 cDNA. The obtained cDNA fragment 739 bp in length was inserted into pi H3M plasmid and expressed (8 x 10(3) IU/ml) in COS cells. A pdB-HhIL-4 expression plasmid was constructed using pdKCR and pdBPV-1 plasmid and transfected into mouse C127 cells by calcium phosphate coprecipitation. Transfected cells exhibited altered cell morphology, could be continuously cultured in DMEM essential medium and secreted IL-4 lymphokine into 1% FCS condition culture medium. High biological activity (2 x 10(4)/ml) from the culture supernatant was obtained by FACS analysis of Fc epsilon receptor expression on B cell surface.

Animals↗
PubMed1995

[The classes, structures, functions and signaling transduction of cytokine receptors].

There are many kinds of cytokine receptors that belong to different receptor families. Most cytokine receptors function as: (1) receptor tyrosine kinase and tyrosine-kinase-associated receptor; (2) receptor serine/threonine kinase; (3) G-protein linked receptor. Following binding with cytokines and activation, the receptors trigger different cascade of intracellular protein phosphorylation to transduction signals, thereby altering the cell's pattern of gene expression and leading to biological effects.

Animals↗
PubMed1994

Extensive anterior decompression for mixed cervical spondylosis. Resection of uncovertebral joints, neural and transverse foraminotomy, subtotal corpectomy, and fusion with strut graft.

STUDY DESIGN: This study examined a new operative procedure for treating mixed cervical spondylosis. OBJECTIVES: To relate postoperative results with extensive decompression using a surgical microscope. SUMMARY OF BACKGROUND DATA: Based on the dissection cadavers and clinical practice, extensive anterior decompression has been designed for mixed cervical spondylosis. It has not been reported that the cervical cord, nerve roots, and vertebral arteries have been decompressed thoroughly at the same time. METHODS: Fifteen patients with mixed cervical spondylosis were treated with extensive anterior decompression using an operative microscope. The pathologic segments in all patients were identified preoperatively with cervical radiography, myelography, computed tomography, computed tomographic myelography, and magnetic resonance imaging. The Japanese Orthopaedic Association classification was used to assess the follow-up results. The operative results demonstrated the efficacy of the surgical approach. RESULTS: All patients improved neurologically, with the average Japanese Orthopaedic Association score improving from 6.3 points preoperatively to 12.4 points at follow-up examination. The plain radiography, computed tomography, and magnetic resonance imaging follow-up examination showed that the anterior part of the cervical canal and the transversaria or neural foramina were enlarged, and that there was satisfactory bony fusion without signs of nonunion and other complications. CONCLUSIONS: Extensive anterior decompression (resection of uncovertebral joints, neural and transverse foraminotomy, subtotal corpectomy, and fusion with strut graft), a new surgical procedure for treating mixed cervical spondylosis, led to excellent follow-up results.

Adult↗
PubMed1994

Isolation, sequence and expression of a novel mouse brain cDNA, mIA-2, and its relatedness to members of the protein tyrosine phosphatase family.

This study describes the isolation of a putative transmembrane protein tyrosine phosphatase (PTP), mIA-2, from a mouse brain cDNA library. The cDNA encodes 979 amino acids containing a unique extracellular domain and a single intracellular catalytic domain. Expression of mIA-2 was found primarily in the central nervous system and in neuroendocrine cells. The sequence shares a high degree of homology with its human counterpart (92% identity), especially in the intracellular domain, which shows 99.3% identity between the two species. In both human and mouse IA-2, several substitutions were found in the highly conserved regions including an Ala to Asp substitution in the core sequence. Bacterial expression of a glutathione S-transferase fusion protein showed that mIA-2 had no enzyme activity with conventional substrates such as Raytide, myelin basic protein, angiotensin, RR-src and pNpp. When tested with the total tyrosine-phosphorylated cellular proteins isolated on an anti-phosphotyrosine antibody column, it also showed little, if any, enzyme activity. These findings suggest that mIA-2 is a new member of the transmembrane PTP family that either has very narrow substrate specificity perhaps requiring post-translational modification for enzyme activity or has a still unknown biological function.

Amino Acid Sequence↗