Antibodies to glutamic acid decarboxylase and P2-C peptides in sera from coxsackie virus B4-infected mice and IDDM patients

The possible role of amino acid sequence and epitope homologies between a protein P2-C of Coxsackie virus B4 and human GAD in the development of host-specific immune response in insulin-dependent diabetes mellitus (IDDM) (molecular mimicry) was investigated. Peptide antibodies to the P2-C protein, GAD65, and GAD67 were raised to analyze their immunoreactivity by enzyme-linked immunosorbent assay and immunoblotting with GAD purified from the brain and pancreas of mice that develop hyperglycemia after the infection. Additionally, antibody reactivity to these peptide antigens was assessed in sera from the virus-infected mice and IDDM patients. All three peptide antisera reacted very strongly with homologous peptides; P2-C antiserum cross-reacted with GAD65 as efficiently as GAD65 antiserum with P2-C, but no cross-reaction was detected between P2-C and GAD67 although cross-reaction between the two GADs was quite pronounced. P2-C antiserum immunocomplexed with GAD65 from mouse brain or pancreas, whereas GAD65 and GAD67 antisera both immunocomplexed with the two GADs from these sources. Most of the sera from virus-infected mice were reactive to brain and pancreas GAD65 and also to P2-C peptide, whereas some reacted to GAD65 and a few to GAD67 peptides. A number of IDDM sera reacted with mouse GAD65 and also with P2-C and GAD65 peptides, whereas only a few reacted with GAD67 peptide. The immunoreactivity of the mouse and IDDM sera to P2-C and GAD65 peptides was blocked by pre-adsorption with mouse GAD. The results suggest that molecular mimicry may play a role in the pathogenesis of the disease.

An interleukin-4-induced transcription factor: IL-4 Stat

Interleukin-4 (IL-4) is an immunomodulatory cytokine secreted by activated T lymphocytes, basophils, and mast cells. It plays an important role in modulating the balance of T helper (Th) cell subsets, favoring expansion of the Th2 lineage relative to Th1. Imbalance of these T lymphocyte subsets has been implicated in immunological diseases including allergy, inflammation, and autoimmune disease. IL-4 may mediate its biological effects, at least in part, by activating a tyrosine-phosphorylated DNA binding protein. This protein has now been purified and its encoding gene cloned. Examination of the primary amino acid sequence of this protein indicates that it is a member of the signal transducers and activators of transcription (Stat) family of DNA binding proteins, hereby designated IL-4 Stat. Study of the inhibitory activities of phosphotyrosine-containing peptides derived from the intracellular domain of the IL-4 receptor provided evidence for direct coupling of receptor and transcription factor during the IL-4 Stat activation cycle. Such observations indicate that IL-4 Stat has the same functional domain for both receptor coupling and dimerization.

[Clinical evaluation of cefpodoxime proxetil on the treatment of bacterial infections]

122 patients with bacterial infections of respiratory tract, ear, nose, and throat, urinary tract and skin and soft tissue were treated with cefpodoxime proxetil. In the treatments of patients with clinical efficacy tates of cefpodoxime proxetil for infections in these four systems were 90.0%, 97.5%, 90.0% and 86.4%, respectively. The bacterial clearance rate of gram-positive bacterial was 96.9%, and that of gram-negative bacteria 96.4%. Adverse drug reaction rate was 18.9%.

Molecular cloning and expression of the gene for a major leucine-rich protein from human hepatoblastoma cells (HepG2)

The human hepatoblastoma cell line, HepG2, exhibits an array of stable properties in culture that have made it a popular cell culture model for studies on regulation of liver-specific gene expression and properties of hepatoma cells. In contrast to other hepatoma cell lines, HepG2 cells overexpress a characteristic detergent-extractable, wheat germ lectin-binding protein with apparent molecular mass of 130 kDa. Using an antibody to screen a phage expression library of HepG2 complementary DNA (cDNA), we identified and cloned a 4734 base pair cDNA which codes for a 130-kDa leucine-rich protein (lrp 130) when expressed in transfected cells. The deduced sequence of lrp130 exhibits sequences weakly homologous to the consensus sequence for the ATP binding site in ATP-dependent kinases and the protein kinase C phosphorylation site of the epidermal growth factor receptor. Consistent with the higher levels of expression of lrp130 antigen, Northern hybridization analysis indicated that HepG2 cells express high levels of the major 4.8 kilobase lrp130 mRNA relative to other hepatoma cells. Although currently of unknown function, lrp130 may be of utility as a marker for liver cell lineages represented by the HepG2 cell line.

Coxsackievirus B4 alters pancreatic glutamate decarboxylase expression in mice soon after infection

The 64,000-M(r) (64K) islet autoantigen, which is considered to be a target protein of beta cell destruction in insulin-dependent diabetes mellitus (IDDM), has recently been identified as the enzyme glutamic acid decarboxylase (GAD). We reported a two- to three-fold increased expression of the antigen in islets of diabetes-susceptible mice following infection with a diabetogenic strain of Coxsackievirus B4 (CB4) at 72-h postinfection (p.i.), a time point of active virus replication in the islets. Most of the infected animals subsequently developed 64K autoantibodies and hyperglycemia. Since the infection increases 64K expression, we have analysed immunoreactive GAD expression with a panel of peptide antisera and two widely-used polyclonal antisera against GAD, and measured GAD activity in the brain, pancreas and islets of these mice. Two isoforms, GAD65 and GAD67, are detected in these tissues from non-infected mice. Both GADs are also present in the infected mice brain at 72 h p.i.; however, their islets contain about three-fold more GAD65, and essentially no detectable GAD67. GAD activity is significantly higher in the brain compared with whole pancreas or islets, and islet GAD activity is higher than pancreas GAD activity. The infection significantly reduces islet GAD activity, but not brain GAD activity. CB4-induced abnormalities in islet GAD expression may play a role in virus-induced diabetes.

Sequence comparison of putative regulatory DNA of the 5' flanking region of the myeloperoxidase gene in normal and leukemic bone marrow cells

Myeloperoxidase (MPO) is an enzyme which is exclusively expressed in immature myeloid cells with downregulation of gene expression occurring during granulocytic maturation. Levels of MPO RNA, protein, and enzyme activity differ, usually in a concordant fashion, among the various classes of acute leukemia and among different cases within a particular class. One portion of the gene thought to be involved in regulation of MPO expression is the proximal 5' flanking region. To determine if mutations in this putatively regulatory region of the MPO gene might be responsible for some of the differences in level of MPO expression among different cases or classes of acute leukemia, we compared the nucleotide sequence of this part of the gene from 16 patients with acute leukemia, with DNA from normal human bone marrow cells and selected other neoplasms and cell lines. The sequence of this regulatory region was found to be identical in cases of acute myeloid leukemia (AML) with tha of normal DNA except for a dA to dG transition in the Alu region, 463 bases upstream from the transcription start site. This base substitution was seen in almost all cases of AML studied, regardless of the level of MPO which they expressed. It was absent from normal human DNA obtained from various tissues, and cases of acute and chronic lymphocytic leukemia, carcinoma of lung, and most cell lines examined. The base substitution was also absent in a remission blood sample from one of the cases which showed the dA to dG transition in leukemic marrow, suggesting that the base substitution is a mutation rather than a polymorphism. Our results suggest that mutations in promoter or enhancer DNA are not an important cause of the differences in level of MPO gene expression seen among different cases or different classes of AML. However, the base substitution we have detected could potentially serve as a useful marker for detection of residual disease in patients with AML following treatment.

Control of fibroblast growth factor receptor kinase signal transduction by heterodimerization of combinatorial splice variants

A differentiated liver cell (HepG2), which exhibits a dose-dependent growth-stimulatory and growth-inhibitory response to heparin-binding fibroblast growth factor type 1 (FGF-1), displays high- and low-affinity receptor phenotypes and expresses specific combinatorial splice variants alpha 1, beta 1, and alpha 2 of the FGF receptor (FGF-R) gene (flg). The extracellular domains of the alpha and beta variants consist of three and two immunoglobulin loops, respectively, while the intracellular variants consist of a tyrosine kinase (type 1) isoform and a kinase-defective (type 2) isoform. The type 2 isoform is also devoid of the two major intracellular tyrosine autophosphorylation sites (Tyr-653 and Tyr-766) in the type 1 kinase. An analysis of ligand affinity, dimerization, autophosphorylation, and interaction with src homology region 2 (SH2) substrates of the recombinant alpha 1, beta 1, and alpha 2 isoforms was carried out to determine whether dimerization of the combinatorial splice variants might explain the dose-dependent opposite mitogenic effects of FGF. Scatchard analysis indicated that the alpha and beta isoforms exhibit low and high affinity for ligand, respectively. The three combinatorial splice variants dimerized in all combinations. FGF enhanced dimerization and kinase activity, as assessed by receptor autophosphorylation. Phosphopeptide analysis revealed that phosphorylation of Tyr-653 was reduced relative to phosphorylation of Tyr-766 in the type 1 kinase component of heterodimers of the type 1 and type 2 isoforms. The SH2 domain substrate, phospholipase C gamma 1 (PLC gamma 1), associated with the phosphorylated type 1-type 2 heterodimers but was phosphorylated only in preparations containing the type 1 kinase homodimer. The results suggest that phosphorylation of Tyr-653 within the kinase catalytic domain, but not Tyr-766 in the COOH-terminal domain, may be stringently dependent on a trans intermolecular mechanism within FGF-R kinase homodimers. Although phosphotyrosine 766 is sufficient for interaction of PLC gamma 1 and other SH2 substrates with the FGF-R kinase, phosphorylation and presumably activation of substrates require the kinase homodimer and phosphorylation of Tyr-653. We propose that complexes of phosphotyrosine 766 kinase monomers and SH2 domain signal transducers may constitute unactivated presignal complexes whose active or inactive fate depends on homodimerization with a kinase or heterodimerization with a kinase-defective monomer, respectively. The results suggest a mechanism for control of signal transduction by different concentrations of ligand through heterodimerization of combinatorial splice variants from the same receptor gene.

[Immunohistochemical study of lung tissues from patients with idiopathic pulmonary fibrosis]

Immunohistochemical analysis using 24 different monoclonal and polyclonal antibodies was applied to lung biopsy and autopsy material from 9 patients with idiopathic pulmonary fibrosis (IPF) and 6 patients without lung disorders as control. Lymphoid, non-lymphoid cells and their subsets as well as extracellular matrix (fibronectin, laminin and collagens type I, III and IV) were observed in lung interstitium. Our results suggest that local B and T lymphoid immune responses are occurring in IPF. Extracellular matrix alterations are closely linked with the local immune responses.

An essential heparin-binding domain in the fibroblast growth factor receptor kinase

Heparin or heparin-like heparan sulfate proteoglycans are obligatory for activity of the heparin-binding fibroblast growth factor (FGF) family. Heparin interacts independently of FGF ligand with a specific sequence (K18K) in one of the immunoglobulin-like loops in the extracellular domain of the FGF receptor tyrosine kinase transmembrane glycoprotein. A synthetic peptide corresponding to K18K inhibited heparin and heparin-dependent FGF binding to the receptor. K18K and an antibody to K18K were antagonists of FGF-stimulated cell growth. Point mutations of lysine residues in the K18K sequence abrogated both heparin- and ligand-binding activities of the receptor kinase. The results indicate that the FGF receptor is a ternary complex of heparan sulfate proteoglycan, tyrosine kinase transmembrane glycoprotein, and ligand.

[Correlation of hepatic necrosis and complement system activation in fulminant viral hepatitis]

The relationship between complement activation and hepatic necrosis was investigated in 110 cases of fulminant, acute or chronic viral hepatitis by examining plasma complement conversion products C3d and C4d and intact C3 and C4 molecules, as well as the local hepatic deposition of C3 IgG globulins in necrotic areas of the liver. The results revealed an excessive activation of plasma C3 in the fluminant hepatitis group. The C3d/C3 ratio was proved to be directly related to the severity of the clinical symptoms. C3 and IgG hepatic depositions in adjacent necrotic areas were found in over 85% of the fulminant hepatitis cases, as compared to 37.5% in cases of chronic active hepatitis. The conclusion was drawn that activation of the complement cascade is responsible for liver tissue damage, while the plasma complement activation represented by increased C3d and C3c fragment production might well reflect hepatic pathology. Therefore, the C3d/C3 ratio could serve as an index to aid clinical management, as well as pointing out a new therapeutic approach.

Heparin-binding fibroblast growth factors and prostate cancer

Studies of model rat prostate tissue and derived cells indicate the insulin-like (IGF), epidermal growth factor (EGF), transforming growth factor beta (TGF-beta) and heparin-binding fibroblast growth factor (HBGF) families and their receptors may play important roles in regulation of normal prostate cell growth. Tumor cells at different levels in the progression from slow-growing, hormone-dependence to fast-growing, hormone-independence exhibit distinct alterations in expression of specific growth factors and their receptor phenotype. Distinct IGF-I and HBGF mRNAs are constitutively expressed in the mesenchymal cells of slow-tumors, but alteration in HBGF receptor phenotype occurs in the epithelial cells. Fast-tumors exhibit even higher constitutive expression of multiple HBGFs. Splice variants in cDNA for the HBGF receptor in fast-tumors suggest constitutive expression of an intracellular receptor, that together with intracellular HBGFs, may constitute an intracellular autocrine system that is independent of exogenous hormones and growth factors.

Identification of tyrosines 154 and 307 in the extracellular domain and 653 and 766 in the intracellular domain as phosphorylation sites in the heparin-binding fibroblast growth factor receptor tyrosine kinase (flg)

Four tyrosine residues have been identified as phosphorylation sites in the tyrosine kinase isoform of the heparin-binding fibroblast growth factor receptor flg (FGF-R1). Baculoviral-insect cell-derived recombinant FGF-R1 was phosphorylated and fragmented with trypsin while immobilized on heparin-agarose beads. Phosphotyrosine peptides were purified by chromatography on immobilized anti-phosphotyrosine antibody and analyzed by Edman degradation and electrospray tandem mass spectrometry. Tyrosine residue 653, which is in a homologous spatial position to major autophosphorylation sites in the catalytic domain of the src and insulin receptor kinases, is the major intracellular FGF-R1 phosphorylation site. Residue 766 in the COOH-terminus outside the kinase domain is a secondary site. Tyrosine residues 154 and 307, which are in the extracellular domain of transmembrane receptor isoforms and are in an unusual sequence context for tyrosine phosphorylation, were also phosphorylated.

Regulation of the human hsp70 promoter by p53

The tumor suppressor p53 is a nuclear phosphoprotein with characteristics of a transcription factor. It displays sequence-specific DNA binding, contains a potent transactivation domain, and has been implicated as both a transcriptional activator and a repressor. Transcription of the human hsp70 gene is stimulated by adenovirus E1a protein. This E1a transactivation of the hsp70 promoter is mediated by CCAAT binding factor (CBF). It is demonstrated here that p53 both represses transcription from the human hsp70 promoter and also interacts with CBF. Thus, the repression of the hsp70 promoter by p53 may be mediated by direct protein-protein interaction with CBF. These results suggest that protein-protein interaction between p53 and specific transcription factors may be an additional mechanism by which p53 regulates gene expression.

Coxsackievirus B4 infection alters thymic, splenic, and peripheral lymphocyte repertoire preceding onset of hyperglycemia in mice

Diabetogenic Coxsackievirus B4 infection may trigger autoimmune islet loss in diabetes-susceptible mice, resulting in hyperglycemia in nearly 90% of the animals at 6-8 weeks postinfection (p.i.). To ascertain whether changes in lymphocyte repertoire following infection could predispose these animals to diabetes, alterations in their thymic, splenic, and peripheral lymphocytes were analyzed. Additionally, lymphocyte changes were correlated with the virus load in these tissues and with lymphocyte migration to the inflammatory pancreas. Splenic B lymphocytes more than doubled at 72 hr p.i. and then continuously decreased by 16% of the noninfected controls at 8 weeks p.i. T lymphocytes (CD4+ + CD8+) decreased by about 50% at 72 hr and then increased to the control level by 8 weeks p.i.; CD8+ subset continuously decreased by 40% of the control at 8 weeks, resulting in a 67% increase in CD4+/CD8+ ratio. Macrophages and CD5+ B subset increased at 72 hr and then dipped by 93% and 84%, respectively, at 8 weeks. In contrast, peripheral B lymphocytes increased by 74% and T lymphocytes decreased by 11% at 8 weeks p.i. Macrophages increased by twofold at 72 hr and then dipped slightly (6%) at 8 weeks, whereas CD5+ B subset increased by 245%. Most prominent thymic T lymphocyte alteration was reflected by about 150% increase in CD4- CD8- cells at 8 weeks p.i. The peak viremia occurred at 72 hr p.i., with highest and lowest virus in the spleen and thymus, respectively. The thymus cleared virus by 3 days, the other tissues by 7 days. Insulitis and acinar necrosis followed infection; infiltrating lymphocytes were mostly CD4+. Virus-induced abnormal lymphocyte maturation may contribute to the development of insulitis and hyperglycemia.

[Treatment of esophageal precancerous lesion with cang dou pill]

In this report, 648 cases of marked epithelium hyperplasia diagnosed with esophageal exfoliative cytology were studied clinically in the high incidence areas (Cixian and Shexian) of esophageal cancer. All these cases were randomly divided into the treated group and the control group. For two years, the former had been given Cang Dou Pill and the latter the placebo. The results reexamined by the cyto-smears showed that the incidence of the esophageal cancer in therapeutic and control group were 1.5% and 4.2% respectively. A significant difference existed between the two groups (P < 0.005). And the reverse rate of marked hyperplasia in the treated and control group were 79.5% and 50.2% respectively. There was significant difference between the two groups (P < 0.01). These results showed that Cang Dou Pill, to some extent, has anti-cancer activity.

Expression and immunochemical analysis of rat and human fibroblast growth factor receptor (flg) isoforms

Potentially 96 splice variants among four genes that code for the human heparin-binding fibroblast growth factor receptor family complicate study of structure, metabolism, and function of single isoforms in mammalian cells. As an alternative, we expressed structural subdomains and isoforms of the flg receptor gene in bacteria and baculoviral-infected insect cells. We developed and characterized a panel of 16 isoform and domain-specific polyclonal and monoclonal antibodies. The panel of antibodies was used to distinguish mature glycosylated ligand-binding and kinase-active and -inactive recombinant isoforms in baculoviral insect cells and transfected mammalian cells and natural isoforms in rat prostate and human liver cells. The results revealed a cell type-specific expression of the flg gene and isoforms that result from combinations of splice variations. Reactive epitopes of monoclonal antibodies against both the three (alpha) and two (beta) immunoglobulin-like disulfide loop extracellular domain isoforms were mapped by cross-reactivity with synthetic polypeptide sequences and deletion mutants expressed in bacteria. The native alpha and beta receptor isoforms differed in display of shared epitopes and suggested that the NH2-terminal Loop I and COOH-terminal Loops II and III of the alpha isoform are interactive. Although the common Loops II and III appear qualitatively sufficient for ligand binding, the results suggest that tertiary relationships among loops in the three and two loop isoforms are distinct and, therefore, the two isoforms may have distinct activities. Spatial models for arrangement of immunoglobulin-like loops in the extracellular domain of the two isoforms are presented.

Substitution of putative half-cystine residues in heparin-binding fibroblast growth factor receptors. Loss of binding activity in both two and three loop isoforms

Alternate use of an exon coding for an 89-residue NH2 terminal immunoglobulin-like disulfide loop results in isoforms of the heparin-binding fibroblast growth factor receptor (FGF-R) with three (FGF-R alpha) and two (FGF-R beta) Ig-like loops in the extracellular domain. Both FGF-R alpha and FGF-R beta isoforms exhibit qualitatively similar ligand-binding activities. In this report, we show by site-directed mutagenesis and analysis of ligand-binding activity in transfected cells that substitution of a cysteine that potentially forms an intra-loop disulfide in either juxtamembrane Loop II or III disrupted maturation and formation of the ligand-binding site in both FGF-R alpha and FGF-R beta isoforms. Neither three loop FGF-R alpha constructions coding for intact Loops I and II adjacent to defective Loop III nor intact Loops I and III separated by defective Loop II exhibited ligand-binding activity. In addition, a two-loop molecule of tandem Loops I and III was inactive. The results suggest that single Loops I, II, or III of FGF-R are insufficient to form a ligand-binding site. Loop I does not form an independent ligand-binding site with either Loop II or III, but interacts with a common ligand-binding site formed by Loops II and III (Xu, J., Nakahara, M., Crabb, J. W., Shi, E., Matuo, Y., Fraser, M., Kan, M., Hou, J., and McKeehan, W. L. (1992) J. Biol. Chem. 267, 17792-17803, 1992).

[Age-related morphological changes in the suprachiasmatic nucleus of the rat hypothalamus]

A comparative ultrastructural investigation of the hypothalamic suprachiasmatic nuclei (SCN) of young, adult and senescent SD male rats was carried out. The neurons and neuroglial cells in SCN of the senile rats displayed more lipofuscin (Lipo) accumulation in comparison with those of the younger animals. Golgi apparatus (Gol) of the three age groups converted from well-ordered cisternae to irregular ones with extensive dilatation and vacuolization. More neuroglial cells with broader somatic membrane appositional to that of neuron participated in satellitosis in the senile age group. Some unusual structures such as special arrangements of the rough endoplasmic reticula and multilamellar neuroglial envelope (Mge) wrapping neurite were encountered in the perikarya of some neurons or SCN neuropile respectively.

Electron spin resonance determination and superoxide dismutase activity in polymorphonuclear leukocytes in congestive heart failure

Electron spin resonance spin trapping technique was used to measure the generation of active oxygen free radicals during the respiratory burst of phorbol myristate acetate-stimulated leukocytes, and the superoxide dismutase activity in healthy subjects and in patients with congestive heart failure. The authors also measured the concentration of peroxidation products (primarily malondialdehyde) by the thiobarbituric acid method. Experimental results showed that the electron spin resonance spectra obtained during the respiratory burst of polymorphonuclear leukocytes stimulated with phorbol myristate acetate primarily were those of the spin adduct of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) with the superoxide anion and to a lesser extent those of DMPO with hydroxyl radical. Compared with healthy subjects, the release of oxygen free radicals in the respiratory burst of polymorphonuclear leukocytes stimulated with phorbol myristate acetate and the concentration of thiobarbituric acid reactive product in plasma were significantly increased in patients with congestive heart failure while the activity of superoxide dismutase was markedly lower. The increased production of oxygen free radicals by polymorphonuclear leukocytes and the decreased capability of antioxidative defences might play an important role in the generation and development of cardiac failure.

Receptor phenotype underlies differential response of hepatocytes and nonparenchymal cells to heparin-binding fibroblast growth factor type 1 (aFGF) and type 2 (bFGF)

Heparin-binding fibroblast growth factors (HBGF) have been implicated in the regeneration of both parenchymal and nonparenchymal cells of the liver. The response to and phenotype of hepatocyte receptors for HBGF-1 (acidic fibroblast growth factor) and HBGF-2 (basic fibroblast growth factor) were compared to keratinocytes, fibroblasts, and endothelial cells. HBGF-1 stimulated DNA synthesis in hepatocytes, keratinocytes, fibroblasts, and endothelial cells whereas activity of HBGF-2 was limited to fibroblasts and endothelial cells. HBGF-2 antagonized the mitogenic activity of HBGF-1 for hepatocytes and keratinocytes. Hepatocytes and keratinocytes exhibited both high- and low-affinity, nonmatrix receptor sites for HBGF-1, but only low-affinity sites for HBGF-2. The mesenchymal cells displayed only high-affinity sites for both HBGF-1 and HBGF-2. Northern blot and immunochemical analysis revealed that the expression of HBGF receptor genes bek and flg are partitioned between normal hepatocytes and nonparenchymal cells, respectively. Expression of epithelial cell-specific, mesenchymal cell-derived HBGF-7 (keratinocyte growth factor) mRNA in regenerating liver tissue was undetectable relative to HBGF-1. The results support a multifunctional role of HBGF-1 acting through different receptor phenotypes in hepatocyte and nonparenchymal cells during liver regeneration.

[Age-related change of synaptic number in the suprachiasmatic nucleus of the rat hypothalamus]

Numerical changes of the synapses in the hypothalamic suprachiasmatic nuclei (SCN) of rats at different ages were investigated with electron microscope, The population of the major SCN synapses formed with dendrite and total number of synapses were found to be reduced with advancing age. Compared with the young animal group, the synaptic number was statistically different from that in the adult or senescent group. As a result of these changes, the function of SCN might decline with aging.

Expression and transforming activity of a variant of the heparin-binding fibroblast growth factor receptor (flg) gene resulting from splicing of the alpha exon at an alternate 3'-acceptor site

Splicing at an alternate 3'-acceptor site results in deletion of a CCCAG in the 5'-sequence of the exon coding for the NH2-terminal immunoglobulin-like disulfide loop of the heparin-binding fibroblast growth factor receptor (flg) alpha isoform. The result is an in-frame stop codon 138 base pairs after the first flg consensus translational initiation site. The next more favorable site predicts the same two loop intracellular receptor isoform, gamma, which was predicted from two different human cDNAs that arise by alternate use of two exons at the same site. Although expressed in normal tissue, the gamma mRNA is increased in rat prostate tumors and confers ability of anchorage-dependent cells expressing non-secreted heparin-binding fibroblast growth factors to grow in soft agar.

[The investigation about age-related changes in vasoactive substances of normal subjects and of patients with essential hypertension]

To prove the effect of aging on the synthesis of renin-angiotensin-aldosterone system, renal kallikrein-kinin system, prostaglandin (PG), and thromboxane (TX) which regulate blood pressure, normotensive subjects and patients with essential hypertension (EH) were investigated in the present study. Although plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were decreased with aging in both groups, there is no significant differences between each groups while compared among each age-groups. Urinary excretion of kallikreins (active, inactive and total) in EH were decreased with aging as similar extent to that of normal subjects. There was no age-related change of kallikrein activation ratio in EH in contrary to normal subjects. In comparison with each age-group, the amount of urinary kallikrein excretion in EH were already small in young age-groups. The amount of urinary PGE2 excretion in female EH group was smaller than that of normal subjects, and there were no age-related changes in both groups. Urinary excretion of TXB2 and 11-dehydro-TXB2, which are the urinary major metabolites of TXA2 which has potent vasoconstrictive action, were increased in the age-group of 80-93 year-old both normal subjects and EH. There were no age-related change in both groups. Although these hypertensive vasoactive substances as renin, aldosterone and TXA2 in EH show the same profile as that in normal subjects, the synthesis of renal antihypertensive vasoactive substances as kallikrein and PGE2 in EH already decrease in younger patients. These results suggest that the lower activities of renal antihypertensive system is a cause of the development of hypertension.

[Detection and characterization of antigen component of circulating immune complex in sera from patients with lung cancer by monoclonal and polyclonal antibodies]

A total of 117 serum samples from 58 patients with lung cancer, 29 patients with nonmalignant thoracic diseases and 30 healthy donors were tested and analyzed for antigen component in CIC with 5 McAbs and PcAb by Sandwich-ELISA. The results indicated that McAbs were reactive with lung cancer associated CIC (positive rates ranging from 20-32%), while PcAbs were reactive with CIC both from lung cancer patients and from those with non-malignant thoracic diseases (positive rates 45.7% and 41.4% respectively). A combined set using a panel of McAbs to detect CIC will give a higher positive rate (49.2%) than using a single McAb. We anticipate that the McAb-ELISA established in this study to detect antigen-specific CIC will be helpful in the clinical diagnosis and prognosis of lung cancer.

[Using two monoclonal antibodies to detect lung carcinoma associated antigen in the sera of patients with lung cancer by BA-ELISA]

In this study two McAbs (LC86aE4 and LC86aC5) were chosen to detect circulating lung carcinoma associated antigen (LAA) in serum samples from 58 patients with lung cancer, 29 patients with nonmalignant thoracic diseases and 30 healthy donors by biotin-avidin (BA)-ELISA. Our data indicate that BA-ELISA was specific, sensitive, reproducible and simple. The rates of positive detection of LAAE4 or LAAC5 alone were found to be higher (44.8% and 48.3% respectively) in patients with lung cancer than in those with nonmalignant thoracic diseases (13.7%) and in normal donors (6.7%) (P less than 0.01). Furthermore, the combined detection of LAAE4 and LAAC5 resulted in a higher positive rate (62.3%) in lung cancer patients. The clinical application of these McAbs and the assay in the diagnosis of lung cancer is discussed.

[Multiple stepwise regression analysis of etiological factors of esophageal cancer in Cixian county]

Cixian county, one of the high-risk counties of esophageal cancer in the world, has a standardized mortality of 142.19/10(5) population, 1969-1971. The incidence of esophageal cancer had dropped year by year from 1974 to 1982. The significance of the incidence tendency was studied. The results are highly significant (P less than 0.001). The causative factors of esophageal cancer including five independent variables: X1 (number of people taking sanitized water), X2 (number of people on pickled Chinese cabbage), X3 (annual output of fruit), X4 (annual output of fresh vegetable) and X5 (annual output of sweet potato) and one dependent variable Y (morbidity of esophageal cancer) were studied by correlative analysis and multiple stepwise regression. Three correlative factors (X1, X2, and X5) with significant effect on the esophageal cancer were selected from the five suspected factors. The result indicated that taking sanitized water, reducing the number of people on pickled Chinese cabbage, changing the structure of food and keeping the nutrient balance, might decrease the incidence of esophageal cancer.

[Flow cytometry in analysis of precancerous lesions of the esophagus]

DNA content of the severe dysplasia cells in the esophageal epithelium was quantitatively analysed using flow cytometry and compared with those of the normal, mild dysplasia and cancer cells. The results showed that DNA index of the severe dysplasia cells was 1.27 +/- 0.11 and there was a significant difference between its value and those of the normal (1.0 +/- 0.02), mild dysplasia (1.01 +/- 0.03) and cancer cells (1.73 +/- 0.35). The DNA content of severe dysplasia cells lies between the normal and cancer cells. The hyperplasia degree of the severe dysplasia cells parallels their DNA contents. This study indicates that flow cytometry is a useful supplementary tool for diagnosis of the tumor.

Effect of sex hormones on NK and ADCC activity of mice

The effect of pharmacologic doses of sex hormones on NK and ADCC activity against YAC-1 lymphoma and CRBC target cells was studied. Estradiol (E) and testosterone (T) administration for 2 weeks caused a substantial reduction of splenic NK activity in TA3 mice of either sex. In prolonging the treatment time, the intensity of suppression was gradually increased. Both E and T have apparently no inhibitory effect on ADCC activity of TA3 mice, although the ADCC activity slightly increased in the early stage of T treatment. The ADCC activity of T-treated male mice was slightly higher than that of E-treated males. Passive transfer of the splenic mononuclear cells and serum of treated mice does not affect the NK and ADCC activity of normal recipient mice. Addition of different concentrations of sex hormones into the culture medium or pre-treatment of effector cells for 12h failed to change the NK and ADCC activity of murine splenic cells.

Measurement of antibody-dependent cell-mediated cytotoxicity by Hb-enzyme release assay (Hb-ERA)

A non-isotope method, hemoglobin-enzyme release assay (Hb-ERA), for measuring antibody-dependent cell-mediated cytotoxicity (ADCC) has been successfully developed. The assay is based on the fact that hemoglobin has peroxidase activity capable of catalyzing the oxidation of o-phenylenediamine to give coloration which can be measured by spectrophotometer. In comparison to the conventional 51Cr release assay, Hb-ERA is economic, sensitive, reproducible and does not have the shortcomings associated with manipulation of radioactive substances. It is applicable in clinical and research laboratories of any scale. The optimum conditions for the assay are as follows: an effector cell: target cell ratio of 10:1 and an incubation period of 14-16 h at 37 degrees C in 5% CO2. The splenic ADCC activity of mice was measured. The cytotoxic index of mice aged 10-14 weeks (39.71 +/- 11.19) was significantly higher than that of 20-24 week-old mice (18.42 +/- 10.31) (P less than 0.001). The ADCC activity is not influenced by sex. The merits and drawbacks of Hb-ERA are objectively evaluated.