Analysis of localization of mutated tissue-nonspecific alkaline phosphatase proteins associated with neonatal hypophosphatasia using green fluorescent protein chimeras

Hypophosphatasia is associated with a defect of the tissue-nonspecific alkaline phosphatase (TNSALP) gene. The onset and clinical severity are usually correlated in hypophosphatasia; patients with perinatal hypophosphatasia die approximately at the time of birth. In contrast, we describe a male neonatal patient with hypophosphatasia who had no respiratory problems and survived. He was compound heterozygous for the conversion of Phe to Leu at codon 310 (F310L) and the deletion of a nucleotide T at 1735 (delT1735), causing the frame shift with the result of the addition of 80 amino acids at the C-terminal of the protein. Because the C-terminal portion of TNSALP is known to be important for TNSALP to bind to the plasma membrane, the localization of wild-type and mutated TNSALP proteins was analyzed using green fluorescent protein chimeras. The expression vectors containing the complementary DNA of fusion proteins consisting of signal peptide, green fluorescent protein, and wild-type or mutated TNSALP, caused by delT1735 or F310L mutation, were introduced transiently or stably in Saos-2 cells. The delT1735 mutant failed to localize at the cell surface membrane, whereas the wild-type and the F310L mutants were located in the plasma membrane and cytoplasm. The assay for enzymatic activity of TNSALP revealed that the delT1735 mutant lost the activity and that the F310L mutant exhibited an enzymatic activity level that was 72% of the normal level. The F310L mutation was also detected in another neonatal patient with relatively mild (nonlethal) hypophosphatasia (reported in J Clin Endocrinol Metab, 81:4458-4461, 1996), suggesting that residual ALP activity of the F310L mutant contributes to the less severe phenotype. The patient is unique, with respect to a discrepancy between onset and clinical severity in hypophosphatasia.

Characterization of the phosphoinositide-linked dopamine receptor in a mouse hippocampal-neuroblastoma hybrid cell line

Previous studies have established that dopamine (DA) can stimulate phosphoinositide (PI) metabolism in the CNS and in the periphery. The present study summarizes our attempt to find a cell line that expresses this dopaminergic system. We describe that the stable clonal HN33.11 cell line, established by fusion of mouse hippocampal cells with neuroblastoma cells (N18TG2) that originate from A/J mouse, natively expresses the D1 DA receptor system that couples to PI hydrolysis. In this cell line, 500 microM DA or SKF38393 produced 43 and 75% increases in inositol phosphate (IP) accumulations, respectively. In contrast, noradrenaline or 5-hydroxytryptamine did not affect IP accumulations. The formation of IP that was stimulated by DA or SKF38393 was selectively blocked by the D1 DA receptor antagonist SCH23390 with IC50 values of 13 and 16 microM. This response was not mediated by the D1A DA receptor and was cyclic AMP-independent, as HN33.11 cells did not express this receptor, and DA or SKF38393 was unable to stimulate the formation of cyclic AMP. In Ca2+-free/100 microM EGTA medium, basal IP level was reduced by 31.5%, but SKF38393-stimulated PI hydrolysis was not affected. SKF38393-stimulated IP accumulation was also not affected by pertussis toxin (PTX) treatment (200 ng/ml), suggesting that this dopaminergic response is mediated by PTX-insensitive G proteins. Co-immunoprecipitation studies indicated that in membranes of HN33.11 cells, D1-like binding sites are coupled to G alpha(q) protein. Blockade of SKF38393-induced PI hydrolysis with antiserum against phospholipase C (PLC) isozymes, performed in permeabilized cells, as well as co-immunoprecipitation studies implicate PLCbeta3 and PLCbeta4 in this dopaminergically mediated PI hydrolysis cascade. The results indicate that HN33.11 cells express a D1-like DA receptor that couples to PLCbeta3/4 via G alpha(q) protein. These cells may therefore be a useful model system for investigating this receptor system.

[Acetabular dysplasia:an experimental study]

OBJECTIVE

To demonstrate whether acetabular dysplasia represents a primary feature of congenital dislocation of the hip or secondary defect.

METHOD

The capsule of twelve puppies aged five to nine weeks was incised and the ligamentum teres was completely severed under anaesthesia. A part of gluteal medium muscle was implanted in the acetabulum and the head of the femur was dislocated from acetabulum. Roentagenogram was made three weeks after dislocation in all animals.

RESULT

As early as three weeks after dislocation, acetabular dysplasia was clearly noted in all animals. There was more acetabular obliquity and increase of acetabular index.

CONCLUSION

The acetabular dysplasia is the result but not the cause of congenital dislocation of the hip. This result provides probably support for the concept of developmental dislocation of the hip.

[Effects of extraneous wild type p53 on malignant growth of human lung cancer cell line.]

BACKGROUND

To study the effects of extraneous wild type p53 on malignant phenotype of human lung cancer cell line (801-D) with mutant type p53 gene.

METHODS

The human lung cancer line (801-D) with mutant type p53 was selected and characterized with PCR-SSCP and DNA sequence analysis. Recombinant plasmid PZiPp53 was constructed , which expressed wild type p53. A transfected cell line , 801-D-p53 was obtained after transfering the plasmid into 801-D cell line by gene gun mediated and selected by G418. The wild type p53 and the alteration of malignant phenotype were detected in the transfected cell line by PCR method and cell line culture and heteroplastic transplant study.

RESULTS

The extraneous wild type p53 gene was detected in 801-D-p53 cell line cultured in vitro one year after transfection. The growth of the transfected cell line was inhibited comparing the parent cell line. The colony formation inhibition rate of the cell line was 96% and the tumorigenicity in nude mice was suppressed. The tumor growth significantly slow and the average volume of the transplant tumor was 1/28 of that of the parent cell line.

CONCLUSIONS

Extraneous wild type p53 gene may stably exist in the human lung cancer cell line with mutant type p53 after wild type p53 transfection and suppress the malignant phenotype of the transfected cell line. These results indicate that the recombinant plasmid expressing wild type p53 may be useful for gene therapy of human lung cancer.

Incidence of obsessive-compulsive disorder in adults

This study addressed the incidence of obsessive-compulsive disorder (OCD) in adults in the general population. The Baltimore cohort of 3481 subjects, originally sampled during the 1981 multisite Epidemiologic Catchment Area Study, was traced. From 1993 to 1996, 1920 people were reinterviewed using the Diagnostic Interview Schedule. The incidence of DSM-III-R obsessive-compulsive disorder in adults was estimated at .55 per 1000 person-years. There was a relatively high rate of new cases in elderly women. It appeared that there were two peaks of onset of OCD over the life span, both of which occur later in female subjects. Subjects with adult incidence OCD often presented for psychiatric treatment, though they did not specify obsessive-compulsive symptoms as the reason. The difference in diagnostic criteria between DSM-III and DSM-III-R substantially influenced the threshold for new case identification.

[Ceruloplasmin gene expression in silicotic rat lung]

In order to investigate the existence of extrahepatic ceruloplasmin (Cp) gene expression during silicotic process, molecular hybridization technique including dot blotting, in situ hybridization and Northern blotting was used. Twenty one days after silica dust intratracheal injection, Cp mRNA was detectable in lung, which was nearly double the content of that in the control (saline injection). In situ hybridization and Northern blotting revealed that the alveolar macrophages in silicosis could express Cp mRNA. It is concluded that lung is a prominent site for Cp gene expression during silicosis and Cp may play a previously unknown role in pulmonary injury or repair.

Expression of matrix metalloproteinase-9 mRNA in osteoporotic bone tissues

Matrix metalloproteinases (MMPs), a sort of important enzymes involved in extracellular matrix metabolism, play critical roles in the process of tissues remodeling, wound healing and metastasis of tumors. Dot blot and in situ hybridization were used in this study to detect the expression and localization of MMP-9, an important proteolytic enzyme implicated in bone resorption in bone tissues. The results showed that the level of MMP-9 mRNA expression in osteoporotic bone tissues was significantly higher than that in normal control group and the cell types that expressed MMP-9 mRNA included mono- and multi-nuclear osteoclasts and some lining cells on the surface of bone matrix. It was suggested that MMP-9 play a key role in the development of bone loss in osteoporosis.

Mutational analysis of the DTDST gene in a fetus with achondrogenesis type 1B

We describe a diastrophic dysplasia (DTDST) gene mutation in a Japanese male fetus with achondrogenesis type 1B and his relatives. Diagnosis in the fetus was based on roentgenographic data and pathological findings of bones and cartilage. Nucleotide sequencing of the DTDST gene demonstrated that the fetus was homozygous for both delVal340 and Thr689Ser and his parents and a healthy brother were heterozygous for the mutations. The former mutation was reported previously in patients with achondrogenesis type 1B, and the latter was detected in 5 alleles of 26 healthy Japanese individuals. These data suggest that delVal340 is associated with achondrogenesis type 1B in the Japanese, whereas a serine to threonine substitution is most likely polymorphic.

Expression of type-I collagen and matrix metalloproteinase-9 mRNA in bone of castrated adult female rats: effects of estrogen

OBJECTIVES

To elucidate the molecular changes of bone collagen during the development of postmenopausal osteoporosis and to investigate the molecular effects of estrogen replacement.

METHODS

An adult ovariotomy rat model was used. Type-I collagen and matrix metalloproteinase-9 (MMP-9) expressions in bone tissues of rats treated by sham surgery (SH), bilateral ovariotomy (OVX) and OVX with estradiol (OVX-E2) were analysed at mRNA level by using dot blot technique. The distribution of mRNA of these two genes in bone tissues was studied by in situ hybridization.

RESULTS

The expression levels of both type-I collagen and MMP-9 in bone tissues of OVX rats were higher than those of SH group, while treated with estradiol, the expression of both genes declined to some degree. In situ hybridization showed that type-I collagen mRNA located in osteoblasts, whereas MMP-9 was mainly expressed in osteoclasts, some lining cells on bone surface, and some mononuclear cells in bone marrow.

CONCLUSIONS

The reduction of high bone turnover in osteoporotic bone tissues induced by estrogen replacement may result from alterations in gene expression related to bone formation and bone resorption. These alterations are consistent with the changes observed previously by histomorphometry and biochemical markers of bone metabolism on OVX animals and postmenopausal osteoporosis.

Age-related decline in beta adrenergic and adenosine A1 receptor function in the heart are attenuated by dietary restriction

Previously published reports from this laboratory have shown that the antiadrenergic effect of adenosine A1 agonists declines with age in the rat heart [ J Mol Cell Cardiol 29:593-602] and that this decline may be caused by a decrease in coupling between adenosine A1 receptors (AdoA1R) and guanine nucleotide-binding proteins [ Circ Res 81:1065-1071]. Dietary restriction (DR; 60% calories of ad libitum) has been shown to attenuate age-related changes in cellular signal transduction pathways. Therefore, the present study investigated whether DR altered the age-related changes in AdoA1R-mediated function in senescent rat hearts. Ventricular membranes were isolated from the hearts of ad libitum (AL) fed and DR male F344 rats that were 6, 12 and 24 months of age. In AL rats, there was an age-related decline in isoproterenol (ISO)-stimulated adenylyl cyclase when compared with the 6-month-old rats. The decline in ISO-stimulated cyclase was attenuated in DR animals. In AL rats, inhibition of ISO-stimulated adenylyl cyclase by the AdoA1R agonist, N6-p-sulfophenyladenosine (SPA) decreased with age. In DR rats, the age-related decline in inhibition was attenuated. Previous results from this laboratory indicated that in AL fed rats, there was an age-related decrease in the percentage of high-affinity binding sites for SPA, from 55% at 6 months to 23% at 24 months. Diet restriction attenuated this age-related shift in high-affinity binding sites so that the percentage of high-affinity sites at 24 months was 42%. Our results suggest that DR maintains AdoA1R function by preventing a loss of high-affinity AdoA1R sites.

Clinical study of multi-drug resistance gene (MDR1) expression in primary ovarian cancer

This study was designed to measure the multi-drug resistance gene (MDR1) mRNA content and analyze clinical relationship between MDR1 expression and drug resistance in primary ovarian cancer. Reverse transcription PCR (RT-PCR) was used to measure MDR1 mRNA content in biopsy sample of 31 primary ovarian cancers (experimental group) and 30 gynecological tumors (control group). The level of 95.2% (20/21) MDR1 expression was relatively low, and the detected rate of MDR1 expression was 67.7% (21/31) in experimental group, which was higher than that in control group (40.0%, P < 0.05). The differences of MDR1 expression between the effective group and no effect group after combined chemotherapy was significant (P < 0.05). No significant relationship was found between MDR1 expression and clinical stage or histological classification or grade of differentiation in experimental group. We are led to concluded that primary ovarian cancers have drug-resistance clones which might express MDR1 spontaneously and expression of MDR1 may be used as a prognostic and predictive indicator for clinical response of ovarian cancers to combined chemotherapy.

Functional interactions among cytoskeleton, membranes, and cell wall in the pollen tube of flowering plants

The pollen tube is a cellular system that plays a fundamental role during the process of fertilization in higher plants. Because it is so important, the pollen tube has been subjected to intensive studies with the aim of understanding its biology. The pollen tube represents a fascinating model for studying interactions between the internal cytoskeletal machinery, the membrane system, and the cell wall. These compartments, often studied as independent units, show several molecular interactions and can influence the structure and organization of each other. The way the cell wall is constructed, the dynamics of the endomembrane system, and functions of the cytoskeleton suggest that these compartments are a molecular "continuum," which represents a link between the extracellular environment and the pollen tube cytoplasm. Several experimental approaches have been used to understand how these interactions may translate the pollen-pistil interactions into differential processes of pollen tube growth.

[Detection of the level of serum antigen recognized by McAbGB2 in breast cancer]

This study sought to verify the levels of serum antigen recognized by McAbGB2 (abbr. serum McAbGB2 antigen) in patients with breast cancer. We adopted the ELISA method and used McAbGB2 to detect the level of serum McAbGB2 antigen in 50 normal persons and 60 patients with breast cancer. The results showed that the level of serum McAbGB2 antigen of 17 preoperative patients with breast cancer was significantly different from that of the normal persons (P < 0.001); the rate of agreement on positivity for the 17 preoperative patients with breast cancer was 88.2% (15/17); the levels of serum McAbGB2 antigen in 8 patients among the 17 preoperative patients with breast cancer decreased from 57.5 +/- 51.3 u/ml (preoperation) to 20.6 +/- 4.98 u/ml (postoperation; the levels of serum McAbGB2 antigen in the other 43 operated patients with breast cancer almost remained normal during post-operative chemotherapy. These suggest that serum McAbGB2 antigen is a marker for breast cancer and can be used for serological diagnosis, treatment and prognosis inspection.

[Anti-virus effect of hepatocyte stimulating substance (HSS) on duck hepatitis B virus in vivo]

We used one day old Beijing ducklings infected by duck hepatitis B virus as experimental model to observe anti-virus effect of HSS. Beijing ducklings hatched within one day were injected intravenously with duck hepatitis B virus (DHBV). Positive DHBV-DNA in ducklings' sera were detected 7 days later. Serum samples were obtained from all ducklings before, during and after drug treatment at different times and stored at -70 degrees C. The collected samples were detected DHBV-DNA by dot-blot hybridization test at the same time. The therapeutic effects were evaluated by OD value of dot-blot and by the inhibitory rate of DHBV-DNA. The results showed that HSS (with 50 mg/kg/day and 200 mg/kg/day) were effective in inhibition of DHBV-DNA during and after drug treatment, especially in the HSS group of large dosage. The inhibitory effect appeared early and high dynamic. The inhibitory rate of DHBV-DNA during and after drug treatment were higher than the NS group (P < 0.05). No inhibitory effect was observed in NS group. The hepatic biopsy showed HSS groups had milder damage than NS group, indicating that the HSS could inhibit the replication of DHBV-DNA in Beijing ducklings.

[Observation of the serum acidic isoferritin levels in patients with hepatocellular carcinoma]

The levels of serum acidic isoferritin (SAIF) in 48 patients with hepatocellular carcinoma (HCC), 30 patients with hepatitis, 28 patients with liver cirrihosis, and 33 healthy subjects were measured by using enzyme-linked immunosorbent assay (ELISA--double-determinant). The result revealed that the SAIF values of HCC, HP and LC did not show normal distribution. The median values were 440 micrograms/L, 21 micrograms/L, 120 micrograms/L and, in normal subjects, 66 micrograms/L respectively. There were statistically significant differences between HCC and the control groups. The sensitivity of SAIF to HCC was 85.46%, with the cut-off point being 250 micrograms/L. SAIF was not correlated to AFP in HCC cases. The values of SAIF had no relationship with the volume of the tumors and the clinical stages. SAIF may be an available and useful serum marker and be beneficial to the diagnosis of early-staged HCC.

[Primary study on the use of ovariectomized rabbits for establishment of osteoporosis model]

Purebred New Zealand female rabbits were used in this study for demonstrating the feasibility of establishing rabbit's primary osteoporosis model. Bilateral ovariectomies were performed. Five to eight months after operation, we observed the BMD, weight, hair colour and living condition of the model. After killing the rabbits, we made biomechanical detection and pathologic histomorphometry using the bones. The weight of bone ash, the content of calcium and phosphorus, and the weight of metra were determined. The results showed that BMD, bone bending stress, weight of bone ash, content of calcium and phosphorus in ash, and weight of metra all decreased (P < 0.05); the number of trabecula decreased and the bone cortex became thinner. All these parameters evidenced the primary founding of rabbit's osteoporosis model. This research provides a basis for studying the pathogenesis of primary osteoporosis and evaluating the efficacy of pharmacotherapy.

Reduced adenosine A1 receptor and G alpha protein coupling in rat ventricular myocardium during aging

Adenosine A1 receptor (A1-AdoR) function in rat ventricles has previously been shown to decrease with age. In the present study, using the ligand [3H]8-cyclopentyl-1,3-dipropylxanthine ([3H]DPCPX) and coimmunoprecipitation of A1-AdoRs with their associated G proteins, we determined the specific binding of A1-AdoR and A1-AdoR/G protein coupling in ventricular myocardium of 6- to 24-month-old Fischer 344 rats. The densities (Bmax) of A1-AdoRs were 5.8 +/- 0.8 fmol/mg protein in 6-month-old rats and 6.1 +/- 1.4 fmol/mg protein in 24-month-old rats, and the dissociation constants (Kd) were 0.32 +/- 0.04 nmol/L in 6-month-old rats and 0.34 +/- 0.05 nmol/L in 24-month-old rats (P > .05). Analysis of the dose-dependent displacement of [3H]DPCPX binding by the selective A1-receptor agonist, N6-p-sulfophenyladenosine (SPA), yielded two affinity binding sites in both 6- and 24-month-old rats. However, the proportion of high-affinity A1-AdoRs was significantly lower in 24-month-old rats (23.5%) compared with 6-month-old rats (54.9%) (P < .05). In solubilized ventricular membranes, specific [3H]DPCPX binding sites were detected in immunoprecipitates of G alpha i3 and G alpha o antisera but not with antibodies for other G alpha proteins. The basal coimmunoprecipitation of A1-AdoR with G alpha i3 and G alpha o proteins decreased by 22% and 21%, respectively, in ventricular membranes of 24-month-old rats compared with that in 6-month-old animals. A1-AdoR stimulation with SPA increased the coprecipitation of A1-AdoR with G alpha i3 and G alpha o proteins by 287% and 245%, respectively, in 6-month-old rats but only by 129% and 140%, respectively, in 24-month-old rats (P < .01). In the absence of changes in A1-AdoR density and G alpha protein levels, an age-related decline in high-affinity A1-AdoR binding sites and a reduction in the association of A1-AdoR with G alpha proteins suggest that the age-related decrease in ventricular A1-AdoR-mediated response is related to a reduction in the coupling between A1-AdoR and their G proteins.

Heterologous desensitization of the rat tail artery contraction and inositol phosphate accumulation after in vitro exposure to phenylephrine is mediated by decreased levels of Galphaq and Galphai

Desensitization of alpha-1 adrenoceptor (alpha1AR)-mediated responses in aortic smooth muscle after exposure to catecholamines or alpha1AR agonists has been widely demonstrated. To determine whether exposure to an alpha1AR agonist results in desensitization of alpha1AR-mediated responses in a resistance artery, rat tail artery rings were exposed to 7.5 or 75 microM phenylephrine (PE) for 22 hr in vitro. Norepinephrine-stimulated contraction was significantly reduced in PE-exposed tail artery rings. Contractions mediated by the alpha2AR agonists, clonidine and UK 14,304, and by serotonin were also reduced in PE-treated tail artery rings. However, the contractile responses to KCl and ionomycin remained unchanged. Norepinephrine-, PE-, endothelin- and serotonin-stimulated inositol phosphate accumulations were reduced in PE-exposed tail artery rings, whereas KCl- and ionomycin-stimulated inositol phosphate accumulation remained unchanged. The density of membrane alpha1ARs, measured by specific [125I]2-([beta-(4-hydroxyphenyl)ethyl]aminomethyl)-1-etralone binding was not changed in PE-desensitized tail arteries. Further studies were performed to examine if alterations in receptor/G protein interaction accompanies arterial desensitization. In these studies receptor-stimulated increases in [35S]GTPgammaS binding to G proteins was assessed in membranes obtained from vehicle (control) and PE-treated tail arteries. In control membranes alpha1AR stimulation increased [35S]GTPgammaS binding to Galphaq and Galphai proteins, whereas the alpha2AR agonist UK14,304 activated [35S]GTPgammaS binding to Galphai exclusively. Both PE- and UK14, 304-induced responses were reduced in membranes from tail arteries that were exposed to either 7.5 or 75 microM PE for 22 hr. Western blot analyses of G protein alpha and beta subunits demonstrated that Galphaq and Galphai protein levels were decreased in PE-exposed tail artery membranes. These data show that the reduced transmembrane signaling for the alpha1AR in tail artery after in vitro PE exposure is associated with decreases in Galphaq and Galphai protein levels. The reduction in these Galpha proteins also appears to mediate the loss of function of alpha2AR and perhaps of other G protein-coupled receptors.

Comparison of the effects of interleukin-1 alpha, interleukin-1 beta and interferon-gamma-inducing factor on the production of interferon-gamma by natural killer

Interferon-gamma inducing factor (IGIF) is a recently identified cytokine which stimulates the production of interferon-gamma (IFN-gamma) by T cells and enhances natural killer (NK) cell cytolytic activity. Protein fold recognition, structure prediction and comparative modeling have revealed that IGIF is a member of the interleukin (IL)-1 cytokine family and has prompted the designation IL-1 gamma. Here we report functional similarities between members of the IL-1 family by comparing the effects of IL-1 alpha, IL-1 beta and IGIF on NK cell production of IFN-gamma. All three IL-1 types enhanced NK cell production of IFN-gamma when induced by IL-2 or IL-12, although at high concentrations (> 10 ng/ml), IGIF was five- to tenfold more potent than IL-1 alpha or IL-1 beta. This effect correlated with enhanced levels of mRNA for IFN-gamma when NK cells were stimulated with IGIF plus IL-12. In contrast to IL-12 and IL-2, the ability of IGIF to stimulate NK cell production of IFN-gamma was not increased by IL-1 alpha or IL-1 beta. The ability of IGIF to enhance IFN-gamma production was independent of the type I and type II IL-1 receptors or the IL-1R accessory protein. Together, these results identify IGIF as a potent stimulator of NK cell production of IFN-gamma and demonstrate that the effect of IGIF on NK cell production of IFN-gamma is similar to that of IL-1 alpha and IL-1 beta but distinct from that of IL-12.

Natural history of Diagnostic Interview Schedule/DSM-IV major depression. The Baltimore Epidemiologic Catchment Area follow-up

BACKGROUND

Natural history can be characterized by incidence, recurrence, and duration of episodes. Research on the incidence of major depression is rare; studies of recurrence and duration are limited to clinical samples.

METHODS

The Baltimore, Md, site of the Epidemiologic Catchment Area Program followed up its 1981 baseline cohort of 3481 respondents with an additional assessment in 1993 to 1996. Interviews were obtained from 1920 respondents (73% of the survivors). The Diagnostic Interview Schedule and the same survey procedures as in 1981 were used, augmented with a Life Chart Interview for dating the onset and duration of syndromes.

RESULTS

There were 71 new cases of Diagnostic interview Schedule/DSM-IV major depression and 23,698 person-years of exposure, generating an estimated incidence of 3.0 per 1000 per year. Incidence peaked while subjects were in their 30s, with a smaller peak when they were in their 50s. Prodromal symptoms often occurred many years before the full criteria for diagnosis were met. Women were at higher risk for becoming new cases but had neither higher risk for recurrence nor longer episodes than men. Episodes of depression lasted for 12 weeks. The duration of an episode, and time to an episode-free year, was longer in the first episode than in recurrent episodes.

CONCLUSIONS

The incidence estimated in this study is consistent with that found in the few other similar studies performed. The bimodality of onset suggests the value of further exploring the heterogeneity of depression via its natural history. Reported differences in prevalence between men and women seem to be due to differences in incidence, not chronicity.

Catechol-O-methyltransferase Val158Met polymorphism: frequency analysis in Han Chinese subjects and allelic association of the low activity allele with bipolar affective disorder

Catechol-O-methyltransferase catalyses the O-methylation of biologically active or toxic catechols and is a major component of the metabolism of drugs and neurotransmitters such as L-dopa, noradrenaline, adrenaline, and dopamine. Human catechol-O-methyltransferase activity is an autosomal partially dominant trait and is strongly associated with a valine to methionine substitution at codon 158 of the protein. About 25% of Caucasians have low activity, 50% intermediate activity and 25% high activity as determined by either phenotypic or genotypic measurement. In black populations, the low activity allele (Met158; COMTL) is less frequent with about 7% being homozygous. Using a PCR based genotyping assay, we report that the Met158 allele is also less frequent in normal Han Chinese subjects with about 3% of the population being homozygous. Because of its role in catecholamine metabolism and several lines of evidence pointing to a locus for psychosis near the COMT gene on chromosome 22q11, we have analysed the COMT Val158Met polymorphism as a candidate susceptibility factor for bipolar affective disorder. We report an association between bipolar affective disorder and the Met158 allele (p = 0.004) and genotype (p = 0.01) in 93 affected Chinese subjects and 98 controls. We hypothesize that either the low activity allele of catechol-O-methyltransferase is a risk factor for bipolar affective disorder in Chinese populations or is in linkage disequilibrium with a nearby susceptibility gene or polymorphism.

Isolation from fetal bovine serum of a fragment b of complement factor B-like protein improving a long-term survival of human endothelial cells

It is known that serum is a most important factor supporting cell survival and growth. Particularly, the deprivation of serum would result in the death of human endothelial cell. Our previous paper reported an endothelial cell-viability maintaining factor (EC-VMFa) purified from fetal bovine serum and identified as an apolipoprotein. In the present further study, it is demonstrated that another potent serum factor (refer as EC-VMFb) is also possessed of the endothelial cell-viability maintaining activity, improving a long-term survival of human endothelial cells in serum-free medium. EC-VMFb has a molecular weight of 66,000 (reduced and nonreduced), pI of 4.5 and has been identified as fragment b of complement factor B (Bb)-like protein by amino-terminal amino acid sequence.

Association analysis of the dopamine D4 gene exon III VNTR and heroin abuse in Chinese subjects

Although social and cultural influences are clearly important, family, twin and adoption studies indicate that genes contribute significantly to substance abuse. Substance abuse is associated with novelty seeking, a heritable human personality trait which may be influenced by alleles of the dopamine D4 (DRD4) gene exon III VNTR. Consequently Kotler et al analysed the DRD4 VNTR in opiate-dependent subjects from Israel, and found a significant excess of the 7-repeat allele. We have attempted to replicate this finding using a Han Chinese case-control sample of 121 heroin-dependent subjects and 154 normal controls. We found two 7-repeat alleles which occurred exclusively in the patient group, and overall there was an excess of longer alleles, which did not reach significance (chi 2 = 7.04; P = 0.07). When the D4 VNTR was divided into 'long' (5-7 repeats) and 'short' (2-4 repeats), a significant excess of long alleles was observed in the patient group (P = 0.023, one-tailed), with an odds ratio of 2.30 (95% CI 1.07-4.93). We conclude that our findings support the hypothesis that alleles of the DRD4 exon III VNTR are susceptibility factors for heroin abuse.

[Determination of dimethyl ether correction factors in gas chromatography with TCD and FID]

Dimethyl ether (DME) correction factors in gas chromatography with thermal conductivity detector (TCD) and flame ionization detector (FID) by using H2 as carrier gas were determined in this work. The homemade DME gas was quantitatively absorbed in ice-cold water. With ethanol as standard, the aqueous mixture was injected into a gas chromatograph, equipped with serially-connected TCD and FID. The weight correction factors of DME based on methanol were 0.86 and 0.55 for TCD and FID respectively. The result for TCD was also confirmed by calculation based on the stoichiometrical transformation of methanol into DME in reaction gas chromatography.

Identification of novel missense mutations (Phe310Leu and Gly439Arg) in a neonatal case of hypophosphatasia

Hypophosphatasia is associated with a defect of the tissue-non-specific alkaline phosphatase gene. We performed a mutational analysis in a surviving patient diagnosed at birth as having hypophosphatasia, on the basis of a low level of serum alkaline phosphatase (ALP) activity and characteristic radiographical findings. She had two sisters, one of whom died of respiratory failure complicated by perinatal hypophosphatasia; the other seemed healthy, with a relatively low activity level of ALP. The patient's parents also had low ALP activity. Sequence analysis of the tissue-nonspecific alkaline phosphatase gene was performed, using genomic DNA and total RNA from the skin fibroblasts of the patient and the peripheral mononuclear cells of her parents. The conversion of Phe to Leu at codon 310 (F310L) and Gly to Arg at 439 (G439R) were identified in the patient. Interestingly, the reconstructive experiments demonstrated that the F310L mutant exhibited an ALP activity level 65% of the normal level, whereas the mutant G439R had no activity. Moreover, the digestion by StuI, after a PCR using complementary DNA extracted from fibroblasts of the patient and lymphocytes of her father, revealed a relatively low messenger RNA level of F310L. These findings suggest that the neonatal case of hypophosphatasia was associated with compound mutations, one of which caused the loss of ALP activity and the other of which caused a slight reduction of the ALP activity, with a relatively low level of messenger RNA.

Purification of apolipoprotein H by polyethylene glycol precipitation

A new method of polyethylene glycol precipitation followed by heparin affinity chromatography was established to purify apolioprotein H (Apo H, beta 2-glycoprotein I). This method is simple and effective and yields more harvest of Apo H (3-4 mg Apo H from 100 ml fetal bovine serum) than the current HClO4 extraction method. There are notable differences between Apo H purified by the polyethylene glycol method [Apo H (PEG)] and Apo H purified by the HClO4 method [Apo H (HClO4)] in respects of their SDS electrophoresis characteristics, circular dichroism spectroscopy, and isoelectric focusing graph. It is concluded that the strong acid HClO4 treatment may induce some disordered structure in Apo H molecule resulting in the lowering of molecular weight and pIs. Apo H (PEG) retains more integrated structure which may be related to its bioactivity.

[Inotropic effect of novel cardiotonic agent, vesnarinone--tests on anaesthetized dogs]

We studied the positive inotropic effect of the novel cardiotonic agent, vesnarinone on open chest and intact anaesthetized dogs hearts. The results indicate that vesnarinone has a dose-effect relationship on increasing the contractile force, LV dp/dt max and stroke volume, and it shortens the ejection time 21%. No effect on blood pressure and heart rate was noted. Vesnarione is more effective than amrinone in terms of positive inotropic effect.

[Preparation and identification of monoclonal antibody GB2 directed against human breast cancer serum antigen]

Spleen cells from BALB/c mice immunized with human breast cancer serum antigen were fused with murine myeloma SP 2/0 cells. After screening with ELISA and limited-dilution cloning, one hybridoma which could stably secrete specific antibody was obtained and designated McAbGB2. The titer of McAbGB2 was up to 1.2 x 10(6) after purified by ammonium sulfate and DEAE-cellulose. The McAbGB2 was defined as murine IgG1 by agarose double immunodiffusiong. Immunoblotting analysis revealed that the antigens with molecular weights of 116 kd and 45 kd recognized by McAbGB2 were distributed in human breast cancer tissue and serum.

[Long-term follow-up results of eleven cases after resection of hepatic metastases from colorectal cancer]

Eleven patients with hepatic metastases from colorectal cancer survived more than 5 years after the resection were reviewed. There were 3 (27.3%) disease-free survivors, the longest survival period was 7 years and 2 months. Compared with 41 survivors of less than 5-year duration after resection, it was shown that close follow-up after resection of the primary cancer, detecting early subclinical hepatic metastases, preoperative lower level of CEA, tumor less or equal to 5 cm in size, single metastatic nodule and radical resection were important factors influening long-term survival (P < 0.05). It is of the opinion that early diagnosis, early resection and re-resection after detecting subclinical local recurrence and metastases play important role in improving long-term response.

Cardiovascular hypertrophy and increased vascular contractile responsiveness following repeated cocaine administration in rabbits

The effects of repeated cocaine administration on contractile responses were studied in adult rabbits. Repeated cocaine exposure caused a significant increase in the maximal response of the aorta to the agonists norepinephrine and serotonin as well as the receptor- independent stimulus KCl when compared to the saline controls. Cocaine exposure caused a significant increase in the wet weights of both heart and aorta. When the contraction was normalized to the wet weight of the aorta there was no difference between rabbits administered cocaine and saline. Acute cocaine administration caused a time-dependent increase in immunoreactivity of the proto-oncogene c-Fos in the aorta. These results show that repeated cocaine administration leads to the development of cardiovascular hypertrophy.

[Detection of serum isoferritin level in 195 patients with cancer]

ELISA (double-determinant) was used to detect the serum isoferritin (SIF) levels in 42 patients with nasopharynx cancer (NPC), 38 with lung cancer (LC), 26 with esophageal cancer (EC) and 89 with other cancers, a total of 195 cases (151 males and 44 females). The results revealed that the positive rate of SIF in patients with cancer was 73.8% (144/195), among which, the positive rates in patients of stage I-II, stage III-IV, in patients not operated upon and in those after operation were 64.8%, 81.3%, 81.4% and 63.4%, respectively. Statistics was significantly different in SIF level between the stage I-II and III-IV groups, and between the un-operation and after operation groups (P < 0.001) by rank sum testing. The positive rates of NPC, LC and EC were 73.8%, 86.8% and 73.1%, respectively. The results have demonstrated that isoferritin is a malignant neoplasm associated antigen, and SIF level is related closely with the development of the tumor and operative treatment.

Purification and characterization of an endothelial cell-viability maintaining factor from fetal bovine serum

Serum is an essential requirement for the growth and long-term survival of human endothelial cells, even in the presence of such defined elements such as polypeptide growth factors and hormones. A polypeptide from fetal bovine serum was isolated and characterized on the basis of long-term survival of human endothelial cells in serum-free culture. The endothelial cell viability maintaining factor has been purified to homogeneity by a combination of polyethylene glycol precipitation, hydroxylapatite, gel permeation and reverse-phase high performance liquid chromatography. The final purified endothelial cell viability maintaining factor has a molecular weight of 65,000 (reduced) and has been identified as bovine apolipoprotein H by amino-terminal amino acid sequence analysis and Western blot analysis. Endothelial cell viability maintaining factor improved a long-term viability of human endothelial cells at maximal concentrations of 2.5-5 micrograms protein/ml in serum-free medium.

Confocal imaging and immunogold electron microscopy of changes in distribution of myosin during pollen hydration, germination and pollen tube growth in Nicotiana tabacum L

Using anti-myosin antibodies, standard immunocytochemical techniques in conjunction with confocal scanning laser microscopy and colloidal gold immunoelectron microscopy we compare changes in the distribution patterns of myosin during the early stages of pollen hydration, germination, tube growth, and myosin associated with isolated vegetative nucleus and the generative cell in Nicotiana tabacum L. Furthermore, on the Western blots of pollen tube proteins, the antimyosin antibodies crossreact only with one polypeptide of approximately 174 kDa. Confocal immunofluorescence microscopy reveals that in hydrated pollen, myosin is discretely associated with the cytoplasmic organelles and numerous punctate structures present in the center of the pollen. Within 30 min following transfer of pollen into the germination medium, that is, with the onset of germination, the centrally located punctate structures are displaced, and we find accumulation of myosin-associated organelles towards one of the germinal apertures from which the pollen tube would emerge. Subsequently, after 45 min of germination with the emergence of germination structure, few punctate structures are detected in the vegetative cytoplasm while intense immunostain is detected just below the plasma membrane of the emerging pollen tube tip. In the older parts of both short and long pollen tubes after 90 to 120 min of pollen germination, few fluorescent structures were found in the pollen tubes, however, numerous punctate fluorescent spots were concentrated in the tip region over a distance of 2 to 3 microns below the plasma membrane of the tube tip. This is further substantiated by colloidal gold immunoelectron microscopy wherein clusters of gold particles are associated with vesicle-like structures in the tip region of the pollen tubes.(ABSTRACT TRUNCATED AT 250 WORDS)

[The lateral thoracic free flap in facio-cervical reconstruction]

We have applied the lateral thoracic free flap in 16 patients with face and/or neck defects during the past three years. 13 flaps survived completely and 3 flaps failed which was substituted with skin grafting. The lateral thoracic free flap possesses many supplying vessels and its advantages include big size, hairless skin with well matched color and texture and inconspicuous donor site that can be closed directly. The technique of hemodilution and microvascular anastomotic apparatus are introduced. The indications of the flap and the limitation of its size are discussed.

[Qualitative observation and quantitative survey on the vasculature of the lateral thoracic region]

Since 1988, we had studied blood vessels on the lateral thoracic region in 21 patients using ultrasound Doppler flowmeter preoperatively, collaborating with operative observation, to measure the length, caliber and rate of existence of 3 main vascular systems. Our study attempted both to ascertain various regular patterns of vasculature, and to provide anatomical data for the choice of proper sites of pedicles of lateral thoracic flap. Our findings showed that the subscapular-thoracodorsal vascular system was the most constant among the 3 systems. Its average length was 15.43 +/- 0.504 cm, average diameter at its origin was 1.58 +/- 0.122 mm. The thoracoepigastric vein as a venous return system could be chosen first. We concluded that this method was a handy, practical and dependable way to determine the vascularity of lateral thoracic flaps.

High molecular weight polypeptides related to dynein heavy chains in Nicotiana tabacum pollen tubes

Nicotiana tabacum pollen tubes contain two high molecular weight polypeptides (about 400 kDa), which are specifically expressed during pollen germination and pollen tube growth in BK medium. The high molecular weight doublet resembles the dynein heavy chains in some biochemical properties. Sedimentation profiles of pollen tube extracts show that the high molecular weight bands have sedimentation coefficients of 22 S and 12 S, respectively. ATPase assay of sedimentation fractions shows an activity ten times higher when stimulated by the presence of bovine brain microtubules in fractions containing the 22 S high molecular weight polypeptide. Both these high molecular weight polypeptides can bind microtubules in an ATP-dependent fashion. A mouse antiserum to a synthetic peptide reproducing the sequence of the most conserved ATP-binding site among dynein heavy chains recognized the two high molecular weight polypeptides. Therefore these polypeptides have sequences immunologically related to the ATP binding sites of dynein heavy chains.

Alpha 1-adrenoceptor responsiveness in the aging aorta

Previous studies from this laboratory have shown that aortic alpha 1-adrenoceptor-mediated responsiveness is altered during maturation and aging. This study examines the possibility that there is a change in the alpha 1-adrenoceptor subtypes in the aorta during maturation and aging. The apparent affinity of norepinephrine, as determined by partial receptor inactivation with the alpha 1-adrenoceptor antagonist phenoxybenzamine, was found to be higher in 1-month-old rats compared to 6- and 24-month-old rats. The alpha 1B-adrenoceptor subtype-selective antagonist chlorethylclonidine was used to examine possible heterogeneity in aortic alpha 1-adrenoceptors. The inhibitory effect of chlorethylclonidine on norepinephrine-stimulated contraction was greater in young animals compared to aged animals. Chlorethylclonidine blocked norepinephrine-stimulated inositol phosphate accumulation in 1-month-old aorta but it produced only partial inhibition in the 6- and 24-month-old aortas. The relatively non-selective alpha 1-adrenoceptor antagonists phenoxybenzamine (0.1 microM) and prazosin (0.1 microM) inhibited inositol phosphate accumulation and contractile responses in all ages. The complete block of alpha 1-adrenoceptor-mediated responses by chlorethylclonidine in younger animals shows that alpha 1-adrenoceptor-mediated responses are mediated by the chlorethylclonidine-sensitive alpha 1-adrenoceptor subtypes. The partial inhibition by chlorethylclonidine of alpha 1-adrenoceptor-mediated responses in 6- and 24-month-old animals indicates an increased role of an alpha 1-adrenoceptor subtype that is relatively insensitive to chlorethylclonidine.

[Development of a monoclonal antibody (AF9) to human breast carcinoma]

A monoclonal antibody AF9 (IgG1) was raised against human breast carcinoma by fusing murine myeloma SP2/0 cells with spleen cells from BALB/c mice immunized with cell membrane extracts from primary breast carcinoma. Immunohistochemical staining using the antibody showed reactivity in 19 out of 20 breast carcinoma tissues and in some nonbreast carcinomas such as hepatic, ovarian, lung, colon, and gastric carcinoma tissues. But no staining was observed in either normal tissues or other carcinomas. By immunological treatment, the antigen recognized by AF9 was referred to be glycoprotein with lipid component, and Western blotting revealed that its molecular weight is 51, 56, 67 and 73kd.

Age-related changes in angiotensin II-stimulated vascular contraction and inositol phosphate accumulation in Fischer 344 rats

This study examined the influence of age on angiotensin II (AII)-stimulated vascular contractile responses and inositol phosphate (IP) accumulation in Fischer 344 rats. In the aorta, AII-stimulated contraction and IP accumulation were markedly reduced in 6- and 24-month-old rats compared to 1-month-old rats. There was not a significant difference in the contractile response to AII between 6- and 24-month-old rats, although IP hydrolysis showed a further decrease between 6 and 24 months. In tail artery, there were no differences in contraction and phosphoinositol metabolism in response to AII in the different ages. Losartan blocked AII-stimulated vascular contraction and IP hydrolysis in both aorta and tail artery while PD123319 did not inhibit either response. These data indicate that during maturation, there is a decline in AII-stimulated aortic contraction and IP accumulation in aorta but not in tail artery and these changes are due to altered AT1 receptor function.

[Detection of isoferritin level in breast cancer tissue and serum]

ELISA (double-determinant) was used to evaluate the isoferritin level in the breast cancer tissue. The isoferritin concentration was measured in cytosol extracts of 25 breast cancer tissues (BCT), 6 cancer surrounding tissues (CST) and 8 normal breast tissues (NBT). With the results of 16,023 +/- 15,732, 2467 +/- 1360 and 1382 +/- 647 ng/mcp (milligrams of ontosol protein), respectively. The isoferritin concentrations of BCT and CST were 11.6 and 1.8 times as much as that of NBT, and the differences were statistically significant (P < 0.001 and 0.05). The serum isoferritin level was also measured in 96 healthy persons and 68 breast cancer patients (mean 58.7 +/- 35.8 and 473.3 +/- 297.3 ng/ml) with the difference as big as 8.1 times. The results have demonstrated that the level of cytosol isoferritin in BCT is an important parameter of breast tissue malignance and may be also responsible for the serum isoferritin increase. Therefore we think that serum isoferritin may be used as a marker for early diagnosis of breast cancer.

Confocal image analysis of spatial variations in immunocytochemically identified calmodulin during pollen hydration, germination and pollen tube tip growth in Nicotiana tabacum L

Using monoclonal anti-calmodulin antibodies in conjunction with confocal scanning laser microscopy we have analysed the spatial variations in the distribution pattern of calmodulin (CaM) during the sequential events of pollen hydration, germination and tube growth in Nicotiana tabacum. These immunocytochemical observations have been complemented by immunochemical studies wherein the anti-calmodulin antibody raised against pea CaM recognises a polypeptide of c. 18 kDa in the pollen extracts. Digitisation of confocally acquired optical sections of immunofluorescence images reveals that in hydrated pollen a high level of CaM is consistently present in the region of the germinal apertures. Subsequently, with the onset of germination a high CaM concentration was found associated with the plasma membrane of the germination bubble and in the cytoplasm in its vicinity, while in the vegetative cytoplasm a weak diffuse and intense punctate signal was registered. CaM immunostain was also detected in association with the plasma membrane of the tube tips in both short and long pollen tubes. Furthermore, the cytosol of the tubes invariably manifested an apically focused CaM gradient. We were, however, unable to detect any vacuolar association of CaM in the older regions of the pollen tubes. Although punctate immunostain was obvious across the pollen tube numerous punctate structures were invariably present in the extreme tip. The possible implications of these findings in development of cell polarity, polarised growth, maintenance of calcium homeostasis and CaM interactions with other mechanochemical motor proteins in effecting propulsion of organelles during pollen hydration, germination and pollen tube growth are discussed.

Prenatal cocaine exposure affects the development of aortic adrenergic innervation and contractile responses

This study examines the effects of prenatal cocaine administration on the development of vascular sympathetic innervation and contractile responsiveness. Rabbits received cocaine (4 mg/kg, iv, bid) or saline during gestational days 8 to 29. Aortas were obtained on postnatal days 10, 20, 30 and 50. Vascular smooth muscle responsiveness was assessed by measuring aortic contractile responses to norepinephrine (NE) and to other vasoconstrictors. Vascular adrenergic innervation was evaluated by measuring desipramine sensitive [3H]-NE uptake into aortic ring segments and aortic NE content. [3H]-NE uptake and NE content were reduced at postnatal days 10 and 20 in the rabbits exposed prenatally to cocaine. Differences were not observed at postnatal days 30 or 50. The contractile response to NE was reduced in rabbits exposed to cocaine prenatally. Maximal response and potency were decreased at postnatal day 10 and potency was still decreased at day 20, but not at the older ages. Contractile responses to serotonin (5-HT) and angiotensin II (AII) were not affected by prenatal cocaine exposure. These results suggest that prenatal cocaine exposure delays the development of aortic adrenergic innervation and alpha adrenoceptor responsiveness.

Kinesin-related polypeptide is associated with vesicles from Corylus avellana pollen

A 100-kDa polypeptide with microtubule-interacting properties was identified in a Golgi vesicle-enriched fraction from Corylus avellana pollen. The k71s23 antibody (directed to the kinesin heavy chain from bovine brain) [Tiezzi et al., 1992: Cell Motil. Cytoskeleton 21:132-137] localized the polypeptide on the external surface of membrane-bounded organelles. Some 100-kDa-containing vesicles copelleted with microtubules (polymerized from purified bovine brain tubulin) either in presence or absence of 5 mM AMPPNP, but they could be released by 10 mM ATP or 0.5 M KCl. The pollen microtubule-interacting protein, salt-extracted from membranes and partially purified by gel filtration, exhibited an ATPase activity (16.2 nmolPi/mg/min) which could be stimulated about 2-fold (32.5 nmolPi/mg/min) by addition of bovine brain microtubules. We suppose that the 100-kDa polypeptide is part of a molecular complex showing properties of the kinesin class.

[ELISA of serum isoferritin and its clinical application]

Serum isoferritin levels were detected by ELISA in 96 normal, 11 cases of hepatocellular carcinoma (HCC), 28 breast cancer (BC), 31 lung cancer (LC), 26 breast fibroma, 11 pneumonia and 11 tuberculosis. The results reveal significant differences of serum isoferritin levels between the normals and the patients, and between the malignant cases and benign cases (P < 0.01). Serum isoferritin demonstrates higher sensitivity in detecting HCC, LC and BC and thus is of great value in the differential diagnosis of these cancers.

An immunoreactive homolog of mammalian kinesin in Nicotiana tabacum pollen tubes

A cytoskeletal apparatus is involved in the movement of vesicles, organelles, and gametes in the pollen tube. The function of microfilaments has been defined quite precisely, but the role of microtubules needs to be further clarified. On the basis of immunological and biochemical investigations, we have identified a polypeptide showing common properties with kinesin, a microtubule-based motor mainly described in nonplant tissues, in the pollen tube of Nicotiana tabacum. Like mammalian kinesin, the kinesin-immunoreactive homolog from Nicotiana tabacum pollen tubes binds to mammalian microtubules in an AMP-PNP dependent manner. The kinesin-like component is likely to be involved in the movement of vesicular material in the growing pollen tube.

[A study on characters of liver isoferritin]

The characters of liver isoferritin from Wistar rat, normal human and patient with hepatocellular carcinoma (HCC) were studied. The ratio of iron to protein of liver isoferritin from patient with HCC were 0.021, which accounts for about one-twelfth of that of liver isoferritin from normal human. The molecular weights of liver isoferritin from normal human and the patient with HCC were 20.5 kd and 21.5 kd, respectively. The electrophoresis patterns of liver isoferritin from both Wistar rat and patient with HCC showed one band, but two bands from normal human. There was cross reaction in immunity among isoferritins from normal human liver, Wistar rat liver and horse spleen by double immunodiffusion. The PAGE patterns of liver isoferritin from different sources could be clearly differentiated. The data presented may serve as a good reference for further study of the relationship between the structure and function of ferritin and may be used practically in clinical medicine.

[Isolation and detection of murine transplantable breast tumor antigen by McAb F36/22]

A transplantable murine breast tumor antigen (called JC tumor) has been recognized by the detection of McAb F36/22 with the method of immunoblotting. JC tumor antigen was isolated by Sepharose-CL-4B, then was purified by McAb F36/22 affinity chromatography. Solid phase RIA detection demonstrated that the specific activity of the antigen which was purified by 188.4 times was 148,000 cpm/mg protein. SDS-PAGE and immunoblot analysis revealed that the tumor antigen possessed a molecular weight of 60kd. Competitive binding RIA indicated that JC tumor antigen inhibited the combining of ductal carcinoma antigen with McAb F36/22. It implied that some groups (antigen determinant) on JC tumor antigen were the same as or similar to those on ductal cancer antigen.