The Phox homology (PX) domain, a new player in phosphoinositide signalling

Phosphoinositides are key regulators of diverse cellular processes. The pleckstrin homology (PH) domain mediates the action of PtdIns(3,4)P(2), PtdIns(4,5)P(2) and PtdIns(3,4,5)P(3), while the FYVE domain relays the pulse of PtdIns3P. The recent establishment that the Phox homology (PX) domain interacts with PtdIns3P and other phosphoinositides suggests another mechanism by which phosphoinositides can regulate/integrate multiple cellular events via a spectrum of PX domain-containing proteins. Together with the recent discovery that the epsin N-terminal homologue (ENTH) domain interacts with PtdIns(4,5)P(2), it is becoming clear that phosphoinositides regulate diverse cellular events through interactions with several distinct structural motifs present in many different proteins.

Regulation of Golgi structure and function by ARF-like protein 1 (Arl1)

Arl1 is a member of the ARF-like protein (Arl) subfamily of small GTPases. Nothing is known about the function of Arl1 except for the fact that it is essential for normal development in Drosophila and that it is associated with the Golgi apparatus. In this study, we first demonstrate that Arl1 is enriched at the trans side of the Golgi, marked by AP-1. Association of Arl1 with the Golgi is saturable in intact cells and depends on N-terminal myristoylation. Over-expression of Arl1(T31N), which is expected to be restricted to the GDP-bound form and thus function as a dominant-negative mutant, causes the disappearance of the Golgi apparatus (marked by Golgi SNARE GS28), suggesting that Arl1 is necessary for maintaining normal Golgi structure. Overexpression of Arl1(Q71L), a mutant restricted primarily to the activated GTP-bound form, causes an expansion of the Golgi apparatus with massive and stable Golgi association of COPI and AP-1 coats. Interestingly, Golgi ARFs also become stably associated with the expanded Golgi. Transport of the envelope protein of vesicular stomatitis virus (VSV-G) along the secretory pathway is arrested at the expanded Golgi upon expression of Arl1(Q71L). The structure of stacked cisternae of the Golgi is disrupted in cells expressing Arl1(Q71L), resulting in the transformation of the Golgi into an extensive vesicule-tubule network. In addition, the GTP form of Arl1 interacts with arfaptin-2/POR1 but not GGA1, both of which interact with GTP-restricted ARF1, suggesting that Arl1 and ARF1 share some common effectors in regulating cellular events. On the basis of these observations, we propose that one of the mechanisms for the cell to regulate the structure and function of the Golgi apparatus is through the action of Arl1.

Lembehyne A, a spongean polyacetylene, induces neuronal differentiation in neuroblastoma cell

Lembehyne A (LB-A), a spongean polyacetylene, induced neuronal cell differentiation in a neuroblastoma cell line, Neuro 2A. The LB-A treatment of Neuro 2A cells predominantly resulted in a morphological change with bipolar neurites. The acetylcholinesterase activity of Neuro 2A was also increased by the treatment of LB-A. Furthermore, the cell cycle of Neuro 2A cells was found to be specifically blocked at the G1 phase by LB-A. The structure-activity relationship study using the LB-A analogues revealed the importance of the terminal 1-yn-3-ol and unsaturated long-chain alkyl moieties for the neuronal differentiation activity of LB-A.

Endofin, an endosomal FYVE domain protein

KIAA0305 is an uncharacterized member of the FYVE domain protein family. It is closely related to SARA, with about 50% identity in the carboxyl-terminal 800-amino acid region. Indirect immunofluorescence microscopy using polyclonal antibodies raised against KIAA0305 revealed that it is enriched in early endosomes. The Myc-tagged version is also faithfully targeted to the early endosome. We have tentatively called KIAA0305 endofin (for endosome-associated FYVE-domain protein). The association of endofin with endosomes is mediated by its FYVE domain because deletion mutants lacking the central FYVE finger motif are distributed in the cytoplasm. In addition, a single point mutation in the FYVE finger motif at cysteine residue 753 (C753S) is sufficient to abolish its endosomal association. Its endosomal localization is also sensitive to the phosphatidylinositol 3-kinase inhibitor, wortmannin. Using in vitro liposome binding assays, we demonstrate that Myc-tagged endofin associates preferentially with phosphatidylinositol 3-phosphate, whereas the C753S point mutant was unable to do so. We also show that endofin co-localizes with SARA but that they are not associated in a common complex because they failed to co-immunoprecipitate in co-expressing cells. Endofin also does not associate with Smad2 nor behave like SARA in affecting transforming growth factor-beta signaling. At high levels of expression, both endofin and SARA can cause an endosome aggregation/fusion effect. In COS7 cells, which can support high levels of exogenous protein expression, both proteins can also cause other structural anomalies in the endocytic pathway, as represented by enlarged vesicular structures. These endosomal aggregates/fusions accumulated endocytosed epidermal growth factor. Taken together, this report provides evidence to suggest that endofin and the highly related SARA are endosomal proteins with potential roles in regulating membrane traffic.

Genotypes and polymorphisms of mutant CCR5-delta 32, CCR2-64I and SDF1-3' a HIV-1 resistance alleles in indigenous Han Chinese

OBJECTIVE

To evaluate the frequencies and polymorphisms of CCR5-delta 32, CCR2-64I and SDF1-3' A alleles conferring resistance to HIV-1 infection in Chinese population from Han ethnic origin.

METHODS

This cohort was comprised of 1251 subjects (915 men and 336 women) aged 15-80 years and none was HIV-1 positive. Genotyping of allelic CCR5-delta 32, CCR2-64I and SDF1-3' A variants was performed using PCR or PCR/RFLP assay, and further confirmed by direct DNA sequencing.

RESULTS

Our finding shows that the delta 32 deletion mutation in the CCR5 gene does occur in this population and can be inherited in a Mendelian fashion in indigenous Han Chinese at a very low frequency of 0.00119 (n = 1254). The frequencies of mutant CCR2-64I and SDF1-3' A alleles were 0.20023 (n = 1251) and 0.2873 (n = 893), in this population, which are higher than those found in American Caucasians. Furthermore the polymorphisms of CCR2-64I and SDF1-3' A alleles in the Han Chinese population were different from those in American Caucasians. Statistical analysis showed that the genotype distribution of CCR5-delta 32, CCR2-64I and SDF1-3' A alleles was in equilibrium according to the Hardy-Weinberg equation.

CONCLUSION

The CCR5-delta 32 mutation may not be a major resistant factor against HIV-1 infection in indigenous Han Chinese. The significance of higher frequencies of CCR2-641 and SDF1-3' A alleles (0.20023 and 0.2791) in the Han population remains to be clarified in HIV-1-positive carriers and AIDS patients.

[Study on pregnancy & embryology in Tibetan medicine]

The author has studied the materials on menstruation, gestational course, embryonic development and hygiene during pregnancy recorded in ancient Tibetan medical literatures, and compared them with that in Han medicine, generally known as TCM. The article points out that Tibetan and Han medicine share some common views in pregnancy and embryology, but, in the aspects of observation and knowledge in menstruation and embryology, Tibetan medicine seems more unique. Tibetan medicine not only recorded foetal shape week by week for 38 weeks, but also presented them in color pictures to illustrate the "fish-tortois-pig" stages in its course of embryonic development which is absent in Han medicine. Tibetan medicine is very creative in its knowledge on pregnant physiology and embryology.

[Sixty years of study on history of medicine of Chinese minorities]

This paper is divided into three parts for the description of history of minority medicine: 1. Liberal period (before 1980), only a few papers were published, mostly individual study. 2. Foundation period (1980-1987), more papers were published, dealing with all aspects of the subject in an organized basis. 3. Flourishing period (1988-1995), an unprecedented and comprehensive development, both quantitatively and qualitatively. An independent branch of the science, History of Minority Medicine, is formed during this period.

A membrane protein enriched in endoplasmic reticulum exit sites interacts with COPII

Although all mammalian COPII components have now been cloned, little is known of their interactions with other regulatory proteins involved in exit from the endoplasmic reticulum (ER). We report here that a mammalian protein (Yip1A) that is about 31% identical to S. cerevisiae and which interacts with and modulates COPII-mediated ER-Golgi transport. Yip1A transcripts are ubiquitously expressed. Transcripts of a related mammalian homologue, Yip1B, are found specifically in the heart. Indirect immunofluorescence microscopy revealed that Yip1A is localized to vesicular structures that are concentrated at the perinuclear region. The structures marked by Yip1A co-localized with Sec31A and Sec13, components of the COPII coat protein complex. Immunoelectron microscopy also showed that Yip1A co-localizes with Sec13 at ER exit sites. Overexpression of the hydrophilic N terminus of Yip1A arrests ER-Golgi transport of the vesicular stomatitis G protein and causes fragmentation and dispersion of the Golgi apparatus. A glutathione S-transferase fusion protein with the hydrophilic N terminus of Yip1A (GST-Yip1A) is able to bind to and deplete vital components from rat liver cytosol that is essential for in vitro vesicular stomatitis G transport. Peptide sequence analysis of cytosolic proteins that are specifically bound to GST-Yip1A revealed, among other proteins, mammalian COPII components Sec23 and Sec24. A highly conserved domain at the N terminus of Yip1A is required for Sec23/Sec24 interaction. Our results suggest that Yip1A is involved in the regulation of ER-Golgi traffic at the level of ER exit sites.

Cellular COPII proteins are involved in production of the vesicles that form the poliovirus replication complex

Poliovirus (PV) replicates its genome in association with membranous vesicles in the cytoplasm of infected cells. To elucidate the origin and mode of formation of PV vesicles, immunofluorescence labeling with antibodies against the viral vesicle marker proteins 2B and 2BC, as well as cellular markers of the endoplasmic reticulum (ER), anterograde transport vesicles, and the Golgi complex, was performed in BT7-H cells. Optical sections obtained by confocal laser scanning microscopy were subjected to a deconvolution process to enhance resolution and signal-to-noise ratio and to allow for a three-dimensional representation of labeled membrane structures. The mode of formation of the PV vesicles was, on morphological grounds, similar to the formation of anterograde membrane traffic vesicles in uninfected cells. ER-resident membrane markers were excluded from both types of vesicles, and the COPII components Sec13 and Sec31 were both found to be colocalized on the vesicular surface, indicating the presence of a functional COPII coat. PV vesicle formation during early time points of infection did not involve the Golgi complex. The expression of PV protein 2BC or the entire P2 and P3 genomic region led to the production of vesicles carrying a COPII coat and showing the same mode of formation as vesicles produced after PV infection. These results indicate that PV vesicles are formed at the ER by the cellular COPII budding mechanism and thus are homologous to the vesicles of the anterograde membrane transport pathway.

A case of Erdheim-Chester disease with bilateral orbital involvement

PURPOSE

To describe a case of Erdheim-Chester disease with bilateral orbital involvement.

METHODS

A 43-year-old female with bilateral proptosis was presented. Its clinical features, image findings, pathological character and therapeutic effect were evaluated.

RESULTS

CT demonstrated bilateral, diffuse orbital mass. Histopathologic assessment revealed a diffuse xanthogranulomatous process with clusters of lipidladen histocytes. Numerous Touton giant cells were scattered throughout the lesion. Renal and heart failure happened during a 6-year follow-up period. Long bones roentgenogram demonstrated diffuse symmetrical sclerosis with extensive, lytic lesions. Systemic administration of corticosteroids, chemotherapy, immunoglobulin and traditional Chinese medicine showed good therapeutic result.

CONCLUSIONS

An administration of systemic corticosteroids, chemotherapy, immunoglobin and traditional Chinese medicine can control Erdheim-Chester disease. Further exploration of its pathogenesis and collection of useful clinical data are required.

Interaction of farnesylated PRL-2, a protein-tyrosine phosphatase, with the beta-subunit of geranylgeranyltransferase II

Protein of regenerating liver (PRL)-1, -2, and -3 comprise a subgroup of closely related protein-tyrosine phosphatases featuring a C-terminal prenylation motif conforming to either the consensus sequence for farnesylation, CAAX, or geranylgeranylation, CCXX. Yeast two-hybrid screening for PRL-2-interacting proteins identified the beta-subunit of Rab geranylgeranyltransferase II (betaGGT II). The specific interaction of betaGGT II with PRL-2 but not with PRL-1 or -3 occurred in yeast and HeLa cells. Chimeric PRL-1/-2 molecules were tested for their interaction with betaGGT II, and revealed that the C-terminal region of PRL-2 is required for interaction, possibly the PRL variable region immediately preceeding the CAAX box. Additionally, PRL-2 prenylation is prequisite for betaGGT II binding. As prenylated PRL-2 is localized to the early endosome, we propose that this is where the interaction occurs. PRL-2 is not a substrate for betaGGT II, as isoprenoid analysis showed that PRL-2 was solely farnesylated in vivo. Co-expression of the alpha-subunit (alpha) of GGT II, betaGGT II, and PRL-2 resulted in alpha/betaGGT II heterodimer formation and prevented PRL-2 binding. Expression of PRL-2 alone inhibited the endogenous alpha/betaGGT II activity in HeLa cells. Together, these results indicate that the binding of alphaGGT II and PRL-2 to betaGGT II is mutually exclusive, and suggest that PRL-2 may function as a regulator of GGT II activity.

Evidence for prebudding arrest of ER export in animal cell mitosis and its role in generating Golgi partitioning intermediates

During mitosis the interconnected Golgi complex of animal cells breaks down to produce both finely dispersed elements and discrete vesiculotubular structures. The endoplasmic reticulum (ER) plays a controversial role in generating these partitioning intermediates and here we highlight the importance of mitotic ER export arrest in this process. We show that experimental inhibition of ER export (by microinjecting dominant negative Sar1 mutant proteins) is sufficient to induce and maintain transformation of Golgi cisternae to vesiculotubular remnants during interphase and telophase, respectively. We also show that buds on the ER, ER exit sites and COPII vesicles are markedly depleted in mitotic cells and COPII components Sec23p, Sec24p, Sec13p and Sec31p redistribute into the cytosol, indicating ER export is inhibited at an early stage. Finally, we find a markedly uneven distribution of Golgi residents over residual exit sites of metaphase cells, consistent with tubulovesicular Golgi remnants arising by fragmentation rather than redistribution via the ER. Together, these results suggest selective recycling of Golgi residents, combined with prebudding cessation of ER export, induces transformation of Golgi cisternae to vesiculotubular remnants in mitotic cells. The vesiculotubular Golgi remnants, containing populations of slow or nonrecycling Golgi components, arise by fragmentation of a depleted Golgi ribbon independently from the ER.

Lack of effects by sigma ligands on neuropeptide Y-induced G-protein activation in rat hippocampus and cerebellum

It has been suggested that neuropeptide Y (NPY) and sigma (sigma) receptor ligands may share a putative NPY/sigma receptor in rat brain. To study whether NPY and sigma receptor ligands have an inverse agonism at this putative NPY/sigma receptor, we measured their effects on G-protein activity in rat brain. Using [35S]GTPgammaS autoradiography, we found that NPY-induced G-protein activation exhibited a discrete distribution pattern in rat brain. G-protein activation in superficial cortical layers and hippocampal CA1-3 region was mainly attributed to Y1 and Y2 receptors, respectively. In the presence of 10 microM sigma-receptor agonist BD737 or 10 microM sigma-receptor antagonist haloperidol, the distribution and density of [35S]GTPgammaS binding stimulated by 10 nM NPY was not significantly altered. In rat cerebellar membranes, NPY stimulated high-affinity GTPase activity in a dose-related manner, with maximal effects of 29% increase over basal level seen at 500 nM. This NPY-elicited GTPase activity was not significantly affected by micromolar concentrations of the sigma-receptor antagonists Dup734 or haloperidol. Since no significant effects by sigma-receptor ligands on NPY-induced G-protein activation were observed, we did not see an inverse agonism of NPY and sigma-receptor ligands at the putative NPY/sigma receptor measured at the level of G-protein activation, suggesting that sigma receptors and NPY receptors do not represent a common population in rat hippocampus and cerebellum. It is also suggested that G-protein activation is not a convergent point for the signal transduction mechanisms of NPY receptors and sigma receptors.

[Genotyping of HIV resistant alleles in indigenous Tibetan ethnic group of China: low frequency of CCR5triangle32 and high frequency of CCR2b-64I alleles]

OBJECTIVE

To investigate the allelic polymorphism of CCR5triangle32, CCR5m303, CCR2b-64I and SDF1-3'A in Tibetan population in Lasa area of China.

METHODS

The genomic DNA samples from 330 Tibetan subjects' whole blood samples were purified by use of QIAgen Blood Kit and identified by PCR or PCR-RFLP analyses.

RESULTS

The mutation frequencies of CCR5triangle32 and CCR5m303 alleles were lower than 0.15%, and those of CCR2 b-64I and SDF1-3'A alleles were 29.42% and 19.24% respectively in the study samples. The allelic polymorphisms of the four alleles of Tibetan population were similar to those of Chinese Han population. Genotype distribution of the four alleles was in accordance with Hardy-Weinberg equilibrium. The above results suggest that Tibetan population may be relatively susceptive to HIV-1.

CONCLUSION

The Chinese Tibetan may have a lower frequency of CCR5triangle32 and a higher frequency of CCR2b-64I allele, compared with Caucasian.

Ykt6 forms a SNARE complex with syntaxin 5, GS28, and Bet1 and participates in a late stage in endoplasmic reticulum-Golgi transport

The yeast SNARE Ykt6p has been implicated in several trafficking steps, including vesicular transport from the endoplasmic reticulum (ER) to the Golgi, intra-Golgi transport, and homotypic vacuole fusion. The functional role of its mammalian homologue (Ykt6) has not been established. Using antibodies specific for mammalian Ykt6, it is revealed that it is found mainly in Golgi-enriched membranes. Three SNAREs, syntaxin 5, GS28, and Bet1, are specifically associated with Ykt6 as revealed by co-immunoprecipitation, suggesting that these four SNAREs form a SNARE complex. Double labeling of Ykt6 and the Golgi marker mannosidase II or the ER-Golgi recycling marker KDEL receptor suggests that Ykt6 is primarily associated with the Golgi apparatus. Unlike the KDEL receptor, Ykt6 does not cycle back to the peripheral ER exit sites. Antibodies against Ykt6 inhibit in vitro ER-Golgi transport of vesicular stomatitis virus envelope glycoprotein (VSVG) only when they are added before the EGTA-sensitive stage. ER-Golgi transport of VSVG in vitro is also inhibited by recombinant Ykt6. In the presence of antibodies against Ykt6, VSVG accumulates in peri-Golgi vesicular structures and is prevented from entering the mannosidase II compartment, suggesting that Ykt6 functions at a late stage in ER-Golgi transport. Golgi apparatus marked by mannosidase II is fragmented into vesicular structures in cells microinjected with Ykt6 antibodies. It is concluded that Ykt6 functions in a late step of ER-Golgi transport, and this role may be important for the integrity of the Golgi complex.

Retinoblastoma-binding Protein 2 (Rbp2) Potentiates Nuclear Hormone Receptor-mediated Transcription

Retinoblastoma-binding protein 2 (Rbp2) was originally identified as a retinoblastoma protein (RB) pocket domain-binding protein. Although Rbp2 has been shown to interact with RB, p107, TATA-binding protein, and T-cell oncogene rhombotin-2, the physiological function of Rbp2 remains unclear. Here we demonstrate that Rbp2 not only binds to nuclear receptors (NRs) but also enhances the transcription mediated by them. Rbp2 interacts with the DNA-binding domains of NRs and potentiates NR-mediated transcription in an AF-2-dependent manner. Both the N-terminal and C-terminal domains of Rbp2 are critical for the transactivation activity of Rbp2 on NRs. The C terminus is the NR-interacting region. In addition, RB functions in maximizing the effect of Rbp2 on the transcription by NRs. These results suggest that Rbp2 is a coregulator of NRs and define a potential role for Rbp2 in NR-mediated transcription.

SNX3 regulates endosomal function through its PX-domain-mediated interaction with PtdIns(3)P

The sorting nexin (SNX) protein family is implicated in regulating membrane traffic, but the mechanism is still unknown. We show that SNX3 is associated with the early endosome through a novel motif (PX domain) capable of interaction with phosphatidylinositol-3-phosphate (PtdIns(3)P). Overexpression of SNX3 alters endosomal morphology and delays transport to the lysosome. Transport from the early to the recycling endosome is affected upon microinjection of SNX3 antibodies. Our results highlight a novel mechanism by which SNX proteins regulate traffic and uncover a novel class of effectors for PtdIns(3)P.

[Cloning and expression of the envelope glycoprotein gD gene of pseudorabies virus EA strain]

The envelope glycoprotein gD gene of pseudorabies virus Ea strain was cloned via PCR technique. Sequence analysis displayed 98% nucleotide sequence homology and 97% deduced amino acid sequence homology between our cloned gD gene and PRV Rice strain gD gene. The recombinant transfer plasmid pSX35A-gD was obtained by inserting D gene into the baculovirus transfer vector pSX35A with whole-phase promoter cassette, then transfected insect cell Hi5 with linearized AcMNPV-OCC- virus DNA, and formed recombinant baculoviruses AcMNPV-OCC(+)-gD by homologous recombination in insect cell. Recombinant baculoviruses infected insect cell Hi5 after being purified by plaque assay. Both SDS-PAGE and Western-blotting showed glycoprotein gD with a molecular weight of about 47 kD was expressed specifically, product was about 6.2% of total cellular protein, and expressed gD was of immunogenicity.

[Effect of benzo(a)pyrene on antioxidant enzyme activities in Boleophthalmus pectinirostris liver]

The effect of different BaP concentrations on the activities of superoxide dismutase(SOD), glutathione peroxidase (GPx) and catalase(CAT) in Boleophthalmus pectinirostris liver was studied under experimental condition. The results showed that the activities of antioxidant enzymes did not change too much with BaP exposure in lower concentration, whereas the SOD and GPx activities were increased significantly with BaP exposure in higher concentration. No statistical changes were observed in the effect of BaP exposure in different concentrations on CAT activities throughout the experiment.

[Decomposition interaction of mixed litter between Chinese fir and various accompanying plant species]

Studies on the decomposition of mixed litter between Chinese fir and 8 accompanying plant species showed that the decomposition of Chinese fir litter was promoted to different degrees by 8 mixed plant species, in which Angiopteris fokiensis had the greatest effect, while Schima superba had certain promotion first, but then, weak inhibition. The order of promotion was Angiopteris fokiensis > Maesa japonica > Ficus simplicissima > Woodwardia japonica > Boehmeria nivea > Castanopsis fargesii > Castanopsis fissa > Dicranopteris dicotoma. Chinese fir litter had a certain inhibition to litter decomposition of Schima superba and Castanopsis fissa, and certain promotion to litter decomposition of Castanopsis fargesii, but the interactions were not significant. There existed an interaction between Chinese fir and some plant species in the course of mixed decomposition. Therefore, rational protection and restoration of understory plant was important to fasten nutrient cycling of Chinese fir plantation ecosystem and to maintain soil fertility.

[Genotype polymorphism and its implications of mannose-binding protein allele in 5 Chinese nationalities]

OBJECTIVE

To detect the genotypes and sequences of the exon 1 of human mannose-binding protein (MBP) allele in 5 Chinese nationalities.

METHODS

The genotypes of MBP gene of 5 Chinese nationalities were detected by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). The exon 1 of the MBP gene of 22 Chinese Hans was analyzed by using ABI 310 genetic analyzer.

RESULTS

The DNA sequences of exon 1 of Chinese MBP gene were acquired. The allele frequencies of the codon 54 of the MBP gene (MBP-54) of 5 Chinese nationalities were 0.181(Hans), 0.128(Uygurs), 0.181(Mongols), 0.179(Tibetans) and 0.181(Yis). The allele distribution for MBP-54 mutation of 5 Chinese nationalities was in good agreement with Hardy-Weinberg equilibrium. Compared with the Hans, Uygurs had a lower MBP-54 mutation rate. There were no differences in the allele frequencies between the chronic hepatitis B patients and health controls in Chinese Hans. The mutations of the codons 52 and 57 were not detected in this study.

CONCLUSION

A higher prevalence of MBP-54 mutation was found in 5 Chinese nationalities, MBP-54 mutation was not associated with the persistence of hepatitis B.

Retinoblastoma protein is functionally distinct from its homologues in affecting glucocorticoid receptor-mediated transcription and apoptosis

The cell cycle regulator, retinoblastoma protein, is known to potentiate glucocorticoid receptor-activated transcription through the interaction of its pocket domain with the transcription coactivator, hBRM. We now show that glucocorticoid receptor-induced apoptosis is also dependent on both the retinoblastoma protein and hBRM. p107 and p130, which share extensive sequence homology with the pocket domain of the retinoblastoma protein but not its N-terminal region, also interact with hBRM but do not support either glucocorticoid receptor-dependent activity. This difference arises from the divergent N-terminal domain of the retinoblastoma protein, which, when fused to the pocket domains, confers upon p107 and p130 the ability to influence glucocorticoid receptor activities. This effect probably results from the promotion of glucocorticoid receptor-targeted chromatin remodeling by the hBRM-containing SWI/SNF complex because the N-terminal domain of the retinoblastoma protein enhances glucocorticoid receptor-hBRM interactions. These results highlight that, besides the interaction between hBRM and the pocket domain of RB, the N-terminal region of the retinoblastoma protein is also essential for glucocorticoid receptor-induced apoptosis and the potentiation of glucocorticoid receptor-mediated transcription and provide a basis for functional distinction between the retinoblastoma protein and its homologues.

Stimulation of NF-E2 DNA binding by CREB-binding protein (CBP)-mediated acetylation

The hematopoietic transcription factor NF-E2 is an important regulator of erythroid and megakaryocytic gene expression. The transcription cofactor cAMP-response element-binding protein (CREB)-binding protein (CBP) has previously been implicated in mediating NF-E2 function. In this report, we examined the role of CBP, a coactivator with intrinsic acetyltransferase activity, in the regulation of NF-E2. We found that both the hematopoietic-specific subunit of NF-E2, p45, and the widely expressed small subunit, MafG, interact with CBP in vitro and in vivo. CBP acetylates MafG, but not p45, predominantly in the basic region of MafG. Immunoprecipitation experiments with anti-acetyl lysine antibodies demonstrate that MafG is acetylated in vivo in erythroid cells. Transfection experiments further show that CBP stimulates MafG acetylation in intact cells in an E1A-sensitive manner. Acetylation of MafG augments DNA binding activity of NF-E2, and mutations at the major acetylation sites markedly reduce DNA binding and transcriptional activation by NF-E2. Together, these results suggest that recruitment of CBP by NF-E2 to specific erythroid/megakaryocytic promoters might regulate transcription by at least two mechanisms involving both modification of chromatin structure and modulation of transcription factor activity.

Targets of a protease inhibitor, KNI-272, in HIV-1-infected cells

The targets of a protease inhibitor, KNI-272, in the HIV-1 life cycle were investigated in this study. Neither expression of HIV-1 Gag proteins nor production of virus particles was detected in cells infected acutely with HIV-1 cultured in the presence of KNI-272. Although HIV-1 proviral DNA was detected in the cells by PCR, the inhibitor depressed the amount of the proviral DNA in a concentration dependent manner. These results indicate that one of the targets of KNI-272 occurs in the stage before the expression of viral structural proteins. No direct inhibition of reverse transcription was found with the inhibitor. To confirm the inhibition of viral protease, persistently HIV-1-infected cells were cultured in the presence of the inhibitor and examined by electron microscopy for the morphology of HIV-1 particles. Doughnut-shaped immature particles were observed in the extracellular space of the cells, and disrupted semicircular shaped particles were also seen at the higher concentration of KNI-272. A bioassay for infectivity showed that the virus particles were not infectious, and immunofluorescent assay using anti-p17 antibody, that does not react with the precursor of Gag protein, revealed that Gag precursor p55 protein in the cells was not processed. Thus, KNI-272 blocked the maturation of viral particles. Consequently, KNI-272 has at least two inhibition targets in the stages of the HIV-1 life cycle.

[Study on the Raman spectra of baotite]

The Raman spectra of baotite have been studies by a type of SPEX-1403 0.85 double laser Raman spectrometer. In this work we report Raman spectra of baotite. The preliminary conclusions based on author's work are drawn as follow: the Raman vibration frequency of two texture type has been observed in baotite. One is the vibration frequency of the Ti-O octahedron, they are 192 and 322 cm-1(B1g), 460 and 488 cm-1 (Eg) and 622 cm-1 (A1g). An other is the vibration frequency of Si-O tetrahedron, they are 980 and 1,122 cm-1. At the same time, some physical properties and chemical compositions of baotite are also discussed in this paper.

[Polymorphisms of chemokine receptor alleles influencing genetic susceptibility to HIV-1 infection in Mongolia population in China]

OBJECTIVE

Mutant frequency and polymorphism of HIV-1 resistance CCR5-Delta32, CCR2b-64I and SDF1-3'A alleles were investigated in Chinese population from Mongolian ethnic origin.

METHODS

Whole blood samples from 134 Mongolian subjects were collected randomly and their genomic DNA were extracted using Qiagen Blood Kit. Allelic frequency was identified by means of PCR or PCR-RFLP analysis. Allelic polymorphism in population and between sex in the sample as well as correlation of the three genes were analyzed by chi(2) test.

RESULTS

The frequencies of the three alleles were as following: CCR5-Delta32 1.1%, CCR2b-64I 24.8% and SDF1-3'A 22.0% respectively. Distribution of the three mutant alleles among the Mongolian population was in accordance with Hardy-Weinberg equilibrium. Statistical analysis showed there was a higher frequency of CCR2b-64I in female than in male subjects (29.2% vs 19.7%). No Statistical difference was found in the allelic frequencies of both CCR5-Delta32 and SDF1-3'A between male and female individuals.

CONCLUSION

Compared with the Caucasian American, there were higher frequencies of CCR2b-64I and SDF1-3'A alleles and lower frequency of CCR5-Delta32 allele found in Mongolian population while the factors responsible for the variation of genetic polymorphisms in different ethnic populations need to be clarified.

Evidence that the sigma(1) receptor is not directly coupled to G proteins

Sigma (sigma) receptors have been implicated in psychosis, cognition, neuroprotection, and locomotion in the central nervous system. The signal transduction mechanisms for sigma receptors have not been fully elucidated. In this study, we examined the possible coupling between sigma(1) receptors and heterotrimeric guanine nucleotide-binding proteins (G proteins) in rodent brain. In sigma(1) receptor-rich cerebellar membrane preparations, the competitive binding curves of two sigma(1) agonists, (+)pentazocine and 1S,2R-(-)-cis-N-[2-(3, 4-dichlorophenyl)ethyl]-N-methyl-2-(1-pyrrolidinyl)cyclohexylamine (BD737), were unaffected by the addition of 10 microM guanosine-5'-O-(gamma-thio)-triphosphate (GTPgammaS). Neither (+)pentazocine (1-100 microM) nor BD737 (0.01-10 microM) stimulated GTPase activities significantly above basal levels in agonist-stimulated GTPase activity assays in cerebellar membranes. Furthermore, when using the method of agonist-stimulated [35S]GTPgammaS binding as assessed by autoradiography, we did not observe significant stimulation of [35S]GTPgammaS binding in rat brain sections by either (+)pentazocine or BD737. The above results demonstrate that the sigma(1) receptor is not likely be directly coupled to G proteins.

[Expression of beta 2 integrins and L-selectin on CML cells after treatment with IFN-alpha and allo-bone marrow transplantation]

OBJECTIVE

To study the expression of L-selectin, Mac-1, LFA-1 on CML progenitor cells in relation to CML progression and therapeutic effect.

METHODS

The expression of adhesion molecules (LFA-1, Mac-1, L-selectin) on bone marrow CD34+ cells from 34 CML patients were analyzed by three-color flow cytometry.

RESULTS

The mean percentage of expression of L-selectin, and LFA-1 on CD34+ CD38-(-)+ cells from untreated CML patients was significantly lower than that from normal controls. Among 8 CML patients treated with IFN-alpha, the expression of L-selectin and LFA-1 on CD34+ CD38- cell (37.6 +/- 5.3%, 42.1 +/- 13.1%) was comparable to that from normal controls (38.2 +/- 9.4%, 48.2 +/- 12.2%). L-selectin expression in CD34+ CD38- cells from CML patients was inversely correlated with the percentage of Ph'(+) cells. In 2 CML patients treated with allo-bone marrow transplantation, the expression rate of L-selectin, IFA-1 and Mac-1 on CD38+ CD38- cells was comparable to that from normal controls.

CONCLUSION

The data suggest that decreased expression of L-selectin and LFA-1 in CML CD34+ cells reflects one of the features of malignant CML progenitors. IFN-alpha and allo-BMT restore the expression of Mac-1, L-selectin and LFA-1 to normal on CML CD34+ cells.

Contrast-enhanced immunoelectron microscopy for Helicobacter pylori

Since a method of contrast enhancement for immunoelectron microscopy has not been available in bacteriology, the morphological localization of proteins of Helicobacter pylori is not well known. In this report, we established a method of contrast enhancement in immunoelectron microscopy in this organism. Immunostained ultrathin sections are stained with a mixture of alcian blue and osmium tetroxide prior to staining with uranyl acetate. This method of staining provided good contrast enhancement of the bacterial cell wall and membrane without any loss of immunolabeled gold particles on the ultrathin section.

[Neural network based on modified simplex method and its application in studying forest self-thinning]

The mechanism of forest self-thinning is generally nonlinear and dynamic, and the artificial neural network has the characteristic of expressing arbitrary nonlinear mapping. In this paper, the feasibility and limitation of artificial neural network used to simulating forest self-thinning was expounded, and the principle and algorithms of the neural network model based on modified simplex method (BP-MSM mixed algorithms) for modeling forest self-thinning were described. Its applications in self-thinning of Populus tremula natural forest Cunninghamia lanceolata plantation were illustrated. The results of forest self-thinning examples show the BP-MSM mixed algorithms were satisfactory in simulating forest self-thinning, and its precision was higher, which develops the method and theory of artificial neural network, and enriches the simulating method of forest self-thinning.

[Distribution of HIV resistance CCR5-delta 32, CCR2-64 I and SDF1-3'A alleles and their polymorphisms in the Han population in China]

OBJECTIVE

To study the frequency and polymorphism of three mutations (CCR5(Delta)32, CCR2-64I and SDF1-3'A alleles) conferring resistance to determined HIV-1/AIDS in the indigenous Han population in China.

METHODS

The study population included 1,267 subjects, of which consisted 98.7% (1,251/1,267) Han people. The genotypes of the three mutations were respectively, detected by polymerase chain reaction (PCR) for CCR5(Delta)32 mutation, or by PCR/RFLP (restriction fragment length polymorphism) assay with the digestion of restriction endonuclease Bsa BI and Msp I for CCR2-64I and SDF1-3'A mutations. DNA sequencing was employed to confirm the accuracy of PCR or PCR/RFLP products.

RESULTS

The frequency of the mutant alleles were: 0.00119 for CCR5(Delta)32; 0.20023 for CCR2-64I, and 0.28723 for SDF1-3'A. The three heterozygous CCR5-wt/Delta32 mutants were identified and no homozygotes were detected in indigenous Han population. The frequencies of CCR2-64I and SDF1-3'A alleles in China were higher than those of Caucasians descents in the USA and Europe.

CONCLUSION

Our data was the first findings on the frequency and polymorphism of CCR5(Delta)32, CCR2-64I and SDF1-3'A alleles in indigenous Han population in China which implied that the indigenous Han people might have a higher genetic susceptibility to the infection of sexually transmitted HIV-1 (R-5) strain. Further study is needed to clarify the significance of higher frequency of CCR2-64I and SDF1-3'A alleles in Han population.

Role of p97 and syntaxin 5 in the assembly of transitional endoplasmic reticulum

Transitional endoplasmic reticulum (tER) consists of confluent rough and smooth endoplasmic reticulum (ER) domains. In a cell-free incubation system, low-density microsomes (1.17 g cc(-1)) isolated from rat liver homogenates reconstitute tER by Mg(2+)GTP- and Mg(2+)ATP-hydrolysis-dependent membrane fusion. The ATPases associated with different cellular activities protein p97 has been identified as the relevant ATPase. The ATP depletion by hexokinase or treatment with either N-ethylmaleimide or anti-p97 prevented assembly of the smooth ER domain of tER. High-salt washing of low-density microsomes inhibited assembly of the smooth ER domain of tER, whereas the readdition of purified p97 with associated p47 promoted reconstitution. The t-SNARE syntaxin 5 was observed within the smooth ER domain of tER, and antisyntaxin 5 abrogated formation of this same membrane compartment. Thus, p97 and syntaxin 5 regulate assembly of the smooth ER domain of tER and hence one of the earliest membrane differentiated components of the secretory pathway.

Prenylation-dependent association of protein-tyrosine phosphatases PRL-1, -2, and -3 with the plasma membrane and the early endosome

PRL-1, -2, and -3 represent a novel class of protein-tyrosine phosphatase with a C-terminal prenylation motif. Although PRL-1 has been suggested to be associated with the nucleus, the presence of three highly homologous members and the existence of a prenylation motif call for a more detailed examination of their subcellular localization. In the present study, we first demonstrate that mouse PRL-1, -2, and -3 are indeed prenylated. Examination of N-terminal epitope-tagged PRL-1, -2, and -3 expressed in transiently transfected cells suggests that PRL-1, -2, and -3 are present on the plasma membrane and intracellular punctate structures. Stable Chinese hamster ovary cells expressing PRL-1 and -3 in an inducible manner were established. When cells were treated with brefeldin A, PRL-1 and -3 accumulated in a collapsed compact structure around the microtubule-organizing center. Furthermore, PRL-1 and -3 redistributed into swollen vacuole-like structures when cells were treated with wortmannin. These characteristics of PRL-1 and -3 are typical for endosomal proteins. Electron microscope immunogold labeling reveals that PRL-1 and -3 are indeed associated with the plasma membrane and the early endosomal compartment. Expression of PRL-3 is detected in the epithelial cells of the small intestine, where PRL-3 is present in punctate structures in the cytoplasm. When cells are treated with FTI-277, a selective farnesyltransferase inhibitor, PRL-1, -2, and -3 shifted into the nucleus. Furthermore, a mutant form of PRL-2 lacking the C-terminal prenylation signal is associated with the nucleus. These results establish that the primary association of PRL-1, -2, and -3 with the membrane of the cell surface and the early endosome is dependent on their prenylation and that nuclear localization of these proteins may be triggered by a regulatory event that inhibits their prenylation.

Case report. Granuloma caused by Cryptococcus neoformans

A case of cerebral cryptococcal granuloma is reported. The diagnosis was based on histological examination and rDNA-PCR identification. Complete cure was achieved with fluconazole.

[Life table analysis of Tsuga longibracteata population]

Tsuga longibracteata is a rare and endangered tree species in China. Based on the life table of population and the theory of survival analysis, the authors worked out the life table of Tsuga longibracteata population drew the curves of mortality density function, hazard rate function and survival, and analyzed the population dynamics. The results show that the population had two peaks of mortality, and the survival curve of the population trended to the type of Deevey II.

Mammalian homologues of yeast sec31p. An ubiquitously expressed form is localized to endoplasmic reticulum (ER) exit sites and is essential for ER-Golgi transport

The yeast coat protein II (COPII) is responsible for vesicle budding from the endoplasmic reticulum (ER). Mammalian functional homologues for all yeast COPII components, except for Sec31p, have been reported. We have cloned a mammalian cDNA whose product (Sec31A) is about 26% identical to Saccharomyces cerevisiae Sec31p. Data base searches also revealed another partial sequence encoding a polypeptide (Sec31B) that is 40% identical to Sec31A. Northern analysis revealed that Sec31A transcripts are ubiquitously and abundantly expressed, while Sec31B transcripts are particularly enriched in the testis and thymus, but present in very low levels in other tissues. Sec31A is localized to vesicular structures that scatter throughout the cell but are concentrated at the perinuclear region. The structures marked by Sec31A contain Sec13, a component of COPII that is well characterized to mark the ER exit sites. Immunoelectron microscopy revealed that Sec31A colocalizes with Sec13 in structures with extensive vesicular-tubular profiles. Antibodies raised against a C-terminal portion of Sec31A co-precipitate Sec13 and inhibit ER-Golgi transport of temperature-arrested vesicular stomatitis G protein in a semi-intact cell assay. Cytosol immunodepleted of Sec31A failed to support vesicular stomatitis G protein transport, which can be rescued by a high molecular weight fraction of the cytosol containing both Sec31A and Sec13. We conclude that Sec31A represents a functional mammalian homologue of yeast Sec31p.

[Epidemiological feature on diabetes mellitus among permanent inhabitant in the Special Economic Zone of Shenzhen]

OBJECTIVE

To investigate prevalence and relevant factors of diabetes mellitus among permanent inhabitant in Shenzhen.

METHODS

The prevalence of 8 200 inhabitants aged over 20 in Shenzhen was studied. Blood glucose was determined by glucose - oxidase method.

RESULTS

According to the WHO diagnostic standard, the prevalence rates of DM and IGT were 4.23% and 11.94% respectively. The prevalence increased apparently with age. The history of clan and overweight were related to the prevalence rates of DM and IGT. The people of DM and IGT were mostly accompanied with high levels of triglyceride, total cholesterol, uric acid, creatinine and low level of high dense lipoprotein (HDL).

CONCLUSION

The history of clan, old age, overweight and higher fattiness were found risk factors of DM and IGT.

[Quantitative characteristics of rare and endangered Castanopsis kawakamii population]

In this paper, a new self-adaptive model for population growth, i.e. S = exp(alpha ln2(1 + ce-rt) + beta ln(1 + ce-rt) + gamma) was established, which combined Logistic, Smith, Gompertz, Gui-Lawson, Zhang-Logistic and Liu-Logistic models. Estimations with genetic algorithm showed that the new model was more suitable than other models to simulate the actual growth trend of Castanopsis kawakamii population.

[Energy distribution of Phyllostachys pubescens ecosytem in north Fujian]

Based on the data obtrained from 40 Phyllostachys pubescens plots in Jianou City of Fujian Province, the distribution of energy was studied in this paper. The results showed that the energy contained in stems, branches and leaves, and underground parts of P. pubescens ecosystem were 4.2322 x 10(8) kJ.hm-2, 0.9230 x 10(8) kJ.hm-2 and 1.7643 x 10(8) kJ.hm-2, accounting for 61.32%, 13.11% and 25.57% of the total energy respectively.

Preferential association of syntaxin 8 with the early endosome

Members of the syntaxin family play a fundamental role in vesicle docking and fusion of diverse transport events. We have molecularly characterized syntaxin 8, a novel member of the syntaxin family. The nucleotide sequence of cloned rat cDNA predicts a polypeptide of 236 residues with a carboxyl-terminal 18-residue hydrophobic domain that may function as a membrane anchor. Characteristic of syntaxins, syntaxin 8 also contain regions that have the potential to form coiled-coil structures. Among the known syntaxins, syntaxin 8 is most homologous to syntaxin 6 which is predominantly associated with the trans-Golgi network (TGN). The syntaxin 8 transcript is detected in all rat tissues examined by northern blot. Antibodies against recombinant syntaxin 8 recognize a 27 kDa protein that is enriched in membrane fractions containing the Golgi apparatus and the endosomal/lysosomal compartments. Syntaxin 8 in membrane extract could be incorporated into a 20S protein complex in a way that is dependent on the soluble N-ethylmaleimide-sensitive factor (NSF) and soluble NSF attachment protein ((alpha)-SNAP), suggesting that syntaxin 8 is indeed a SNAP receptor (SNARE). Indirect immunofluorescence microscopy reveals that the majority of syntaxin 8 is localized to the early endosome marked by Rab5. This is corroborated by immunogold labeling experiments showing enrichment of syntaxin 8 in the early endosome and its co-labeling with Rab5.

[Relationship between blast crisis of chronic myeloid leukemias and abnormality of p16 and calcitonin genes]

OBJECTIVE

To study the relationship between homozygous deletions of p16 gene and calcitonin hypermethylation and chronic myeloid leukemia (CML) blast crisis.

METHODS

Semiquantitative multiplex polymerase chain reaction (PCR) was used to detect homozygous deletions of p16 gene and semiquantitative PCR to detect calcitonin gene hypermethylation in 53 CML patients.

RESULTS

In 53 CML patients, homozygous deletion of p16 gene was found in none of them in chronic phase, while in 6.3% (1/16) of them in myeloid blast crisis, 66.7% (8/12) in lymphoid blast crisis, and 2/5 (40%) in mixed cell blast crisis. Calcitonin gene hypermethylation was found in 10% (2/20), 68.8%(11/16), 16.7%(2/12), and 40% (2/5), respectively.

CONCLUSION

There is intimate relationship between homozygous deletions of p16 gene and CML in lymphoid blast crisis, between calcitonin gene hypermethylation and CML in myeloid blast crisis. Moreover, abnormality of both genes may be associated with mixed cell blast crisis in CML patients. Simultaneous detection of the two genes help early pickup CML patients in blast crisis.

[Genetic polymorphism in natural populations of D. virilis]

In this paper we analysed the RFLP of mtDNA in Lanzhou (LZ) population of D. virilis. By reanalysing the RFLP data of our previous work on other natural populations of D. virilis, a phylogenetic tree was produced based on the UPGMA method. It shows three main clusters: the Northern populations (LZ QD), the East China populations (NJ, SH, NB) and the Southern population (QZ). With the mtDNA's RFLP data and the results of our former work on allozyme variation in natural populations of D. virilis, we suggest that there exists a latitudinal cline of genetic variation in natural populations of D.virilis. The mechanism for the maintenance of the observed latitudinal pattern is discussed.

Effect of integrin on procollagen synthesis by fibroblasts from scleroderma

OBJECTIVE

To investigate the effect of integrin on fibroblasts from scleroderma in the production of procollagen.

METHODS

Phosphorothioate modified antisense oligonucleotides were used to interfere with the expression of integrin alpha 5 or beta 1 subunit on fibroblasts from 10 cases of scleroderma, and then the changes of procollagen mRNA due to the decline in level of integrin were observed by using RT-PCR.

RESULTS

Expression of integrin alpha 5 or beta 1 subunit was specifically inhibited by their corresponding antisense oligonucleotides. Fibroblasts with decreased expression of alpha 5 or beta 1 subunit produced lower level of procollagen alpha 1 (I), alpha 1 (III) mRNA in comparison to the control.

CONCLUSION

Overproduction of procollagen may be inhibited at the level of transcription by lowering the expression of integrin alpha 5 or beta 1 subunit on fibroblasts in scleroderma.

[A Raman spectral studies of rare-earth (REE) fluoro-carbonate minerals]

The Raman spectra of REE fluoro-carbonate minerals were studies by a type of RIT-30 laser Raman spectrometer. On the basis of Raman spectral properties, REE fluoro-carbonate minerals can be divided into three groups: Ba-REE fluoro-carbonate mineral, Ca-REE fluoro-carbonate mineral and REE fluoro-carbonate mineral. Obviously, a differential kind of mineral is different in the vibration frequency of the Raman spectra. They are as follows: Cordylite v1-1 088, v2-967, v3-1 538, v4-720, 628; Hauheite v1-1 089,v3-1 525, 1 596, v4-720, 649; Cerbaite v1-1 088, v2-911, v3-1 516, v4-718,625; Parisite v1-1 095,1 075, v2-915, v3-1 461, v4-744, 732; Bastnesite v1-1 098, v2-835, v3-1 476, 1 447, v4-732.

A role for Tlg1p in the transport of proteins within the Golgi apparatus of Saccharomyces cerevisiae

Members of the syntaxin protein family participate in the docking-fusion step of several intracellular vesicular transport events. Tlg1p has been identified as a nonessential protein required for efficient endocytosis as well as the maintenance of normal levels of trans-Golgi network proteins. In this study we independently describe Tlg1p as an essential protein required for cell viability. Depletion of Tlg1p in vivo causes a defect in the transport of the vacuolar protein carboxypeptidase Y through the early Golgi. Temperature-sensitive (ts) mutants of Tlg1p also accumulate the endoplasmic reticulum/cis-Golgi form of carboxypeptidase Y at the nonpermissive temperature (38 degrees C) and exhibit underglycosylation of secreted invertase. Overexpression of Tlg1p complements the growth defect of vti1-11 at the nonpermissive temperature, whereas incomplete complementation was observed with vti1-1, further suggesting a role for Tlg1p in the Golgi apparatus. Overexpression of Sed5p decreases the viability of tlg1 ts mutants compared with wild-type cells, suggesting that tlg1 ts mutants are more susceptible to elevated levels of Sed5p. Tlg1p is able to bind His6-tagged Sec17p (yeast alpha-SNAP) in a dose-dependent manner and enters into a SNARE complex with Vti1p, Tlg2p, and Vps45p. Morphological analyses by electron microscopy reveal that cells depleted of Tlg1p or tlg1 ts mutants incubated at the restrictive temperature accumulate 40- to 50-nm vesicles and experience fragmentation of the vacuole.

Changes of host natural killer cell activity in F344 rats during gastric carcinogenesis induced by N-methylnitrosourea

To evaluate the role of NK cells during gastric carcinogenesis, especially in early stage of tumorigenesis, the changes of NK activity was examined. Rats were given N-methylnitrosourea (MNU) at a concentration of 100 ppm in their drinking water for 15 weeks. Rats were sacrificed sequentially on week 15, 18, 20, and 40 of the experimental period. Histological changes such as mild erosion, regenerative changes, focal or severe atypical lesions and invasive adenocarcinoma were observed sequentially in the pyloric region. Adenomatous hyperplasia was induced in majority of the rat stomach in MNU-treated group and incidence of adenocarcinoma was 20% in 40 weeks of MNU-treated group. There was no difference in NK activity until week 20, however, it was increased in MNU-treated rats at 40 week, when compared to that of untreated control group. From week 15, the ratio of pepsinogen altered pyloric gland (PAPG) between untreated control and MNU-treated rats was progressively increased, but there was no significant increment in the number of PAPG in MNU-treated rats after 20 weeks. NK activity was increased in MNU-treated rats, when compared to that of untreated control group. These results suggest that PAPG is a relatively good marker for the evaluation of progression of gastric carcinogenesis and increased NK activity is shown, especially in early stage of gastric carcinogenesis.