Relationship between flocculation of activated sludge and composition of extracellular polymeric substances

Activated sludge flocs are a flocculated mass of microorganisms, extracellular polymeric substances (EPS) and adsorbed organic and inorganic material. The structure of the floc is very heterogeneous and flocs with very different properties and morphologies may occur, depending on the conditions in the activated sludge treatment plant and wastewater composition. Present thinking suggest that cations, such as calcium, create cationic bridges with EPS excreted by the bacteria and thereby hold the various floc constituents together. However, due to the complex and heterogeneous nature of activated sludge, the mechanisms have neither been thoroughly investigated nor successfully quantified. A better understanding and description of the biological flocculation process is necessary in order to establish more efficient operational strategies. The main aim of this study was to get a comprehensive and unique insight into the floc properties of activated sludge and to assess the relative impact of chemical and physical parameters. A variety of sludges from full scale treatment plants with different settling properties were characterised. The interrelationships between floc parameters such as composition of EPS, surface properties and floc structure, and their effect on the flocculation and separation properties were assessed. The results indicate that the EPS, both in terms of quantity and quality, are very important for the floc properties of the activated sludge. However, presence of filaments may alter the physical properties of the flocs considerably. The EPS showed positive correlations to sludge volume index (SVI) if only sludges with low or moderate numbers of filaments were included. The surface properties were more affected by the composition of the EPS than by the number of filaments. The EPS showed positive correlation to negative surface charge and a negative correlation to relative hydrophobicity and flocculation ability. The negative correlation between flocculation ability and amount of EPS was surprising. The shear sensitivity, measured as degree of erosion of flocs when subjected to shear, was more affected by floc size and number of filaments than amount of EPS.

[The prognostic value of serum neuron specific enolase detection in small cell lung cancer]

OBJECTIVE

To evaluate the prognostic value of NSE detection in small cell lung cancer.

METHODS

144 unresectable small cell lung cancer patients were eligible in the retrospective study. NSE was analyzed before chemotherapy and 21 days after chemotherapy using ELISA method.

RESULTS

For D1-NSE, 98 (68.1%) were NSE positive and 46(31.9%) were NSE negative; for D21-NSE, 57(39.6%) were NSE positive and 87 (60.4%) were NSE negative. In univariate analysis, both D1-NSE and D21-NSE have prognostic significance. But in multivariate analysis only D21-NSE is an independent prognostic factor.

CONCLUSION

D21-NSE in small cell lung cancer is an independent prognostic factor and may be proposed for use in the clinic and research.

Expression of CD5 on hematogones in a 7-year-old girl with Shwachman-Diamond syndrome

We report increased numbers of hematogones in a 7-year-old girl with pancytopenia due to Shwachman-Diamond syndrome. Her hematogones expressed the T-cell marker CD5 as well as CD19, CD10, and CD20, and terminal deoxynucleotidyl transferase and HLA-DR. These findings suggest that hematogones are precursors of both CD5-positive B cells and CD5-negative B cells. Thus CD5-positive B cells in bone marrow may be derived from bone marrow stem cells, and not from the residual fetal B cells of yolk sac/liver origin. The finding of CD5 expression on hematogones also raises the possibility that neoplastic B cells of chronic lymphocytic leukemia, which characteristically co-express CD5 and CD19, may be derived from CD5-positive B-cell precursors in bone marrow and not from mature B cells in lymph nodes.

Specific site methylation in the 5'-flanking region of CYP1A2 interindividual differences in human livers

Human cytochrome P4501A2 (CYP1A2) is involved in the metabolism of a large number of common drugs and is responsible for the metabolic activation of numerous promutagens and procarcinogens. Large interindividual differences exist in the expression of this enzyme. This variability has important implications for drug efficacy and cancer susceptibility. In this sudy, the methylation status of the CCGG site (bp -2759) located adjacent to an AP-1 site in the 5'-flanking region of the CYP1A2 gene was assessed in liver samples from a pool of 55 human donors. DNA methylation is an important epigenetic mechanism controlling gene expression and may be one of the molecular mechanisms underlying the interindividual variation. Analysis was conducted using Hpa II digestion and PCR. Results showed that individual samples varied in the methylation status at this site. The site was found to be hypermethylated in approximately 60% of the samples. To compare methylation status with level of CYP1A2 expression, results were analyzed by median test. In 44% of the samples with expression levels above the median the CCGG site was hypermethylated. However, for those samples with levels below the median hypermethylation of the site was found in 73% of the samples. The difference was statistically significant (p<0.05). These findings indicate that CpG methylation may be involved in controlling the expression of CYP1A2, with hypermethylation reducing expression. Moreover, this approach can be useful in assessing the role of site-specific DNA methylation in interindividual variation of CYP1A2. Analysis of other CpG sites in potentially important regulatory elements of the CYP1A2 gene will continue.

Tumor necrosis factor-related apoptosis-inducing ligand in T cell development: sensitivity of human thymocytes

TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) is a recently identified member of the tumor necrosis factor cytokine superfamily. TRAIL has been shown to induce apoptosis in various tumor cell lines, whereas most primary cells seem to be resistant. These observations have raised considerable interest in the use of TRAIL in tumor therapy. Yet little is known about the physiological function of TRAIL. This is particularly the case in the immune system, where TRAIL has been suggested by some to be involved in target cell killing and lymphocyte death. We have developed a panel of mAbs and soluble proteins to address the role of TRAIL in lymphocyte development. These studies demonstrate activation-induced sensitization of thymocytes to TRAIL-mediated apoptosis and expression of the apoptosis-inducing TRAIL receptors. However, with the use of several model systems, our subsequent experiments rule out the possibility that TRAIL plays a major role in antigen-induced deletion of thymocytes. In contrast to thymocytes, there is no up-regulation of TRAIL receptors in peripheral T cells on activation, which remain resistant to TRAIL. Thus, susceptibility to TRAIL-induced apoptosis is controlled differently by central and peripheral T cells.

Effects of androgen deficiency and replacement on prostate zonal volumes

BACKGROUND AND OBJECTIVES

Androgens play a key role in prostate development and disease. However the effects of androgen deficiency and replacement on the prostate during mid-life are not well understood, and there is no information on their effects on prostate zonal volumes. This study aimed to define the effects of androgen deficiency and androgen replacement therapy on prostate zonal volumes (central, peripheral & total) using planimetric prostate ultrasound with particular emphasis on the central zone of the prostate, the most hormonally sensitive and fastest growing region of the prostate and the zone where nodular benign prostate hyperplasia originates.

PATIENTS AND MEASUREMENTS

Central and total prostate volume were measured directly, and peripheral prostate volume calculated, by a single observer using transrectal ultrasound in 71 hypogonadal men (aged 40 +/- 2, range 18-78 years) who were compared with individually age-matched health controls without prostate or gonadal disease. Among the men with androgen deficiency, 17 men had untreated androgen deficiency (never treated or no treatment for at least 6 months) and 54 men were receiving long-term androgen replacement therapy (median 32 months, 93% > or = 6 months) with testosterone implants (n = 27), testosterone ester injections (n = 24) or other testosterone treatment (n = 3).

RESULTS

Compared with individually age-matched controls, untreated androgen deficient men (n = 17) had reduced central (4.0 +/- 0.5 vs. 6.2 +/- 0.5 ml, P < 0.001) and total (23.4 +/- 2.6 vs. 29.2 +/- 1.6 ml, P < 0.001) prostate volumes whereas the reduction in peripheral prostate volume (19.4 +/- 2.1 vs. 23.0 +/- 1.3 ml, P = 0.15) was not statistically significant. Men with treated androgen deficiency (n = 54) also still had significantly reduced central (4.8 +/- 0.4 vs. 6.8 +/- 0.4, P < 0.001), peripheral prostate volume (19.6 +/- 0.8 vs. 21.6 +/- 0.7 ml, P = 0.06) and total (24.4 +/- 1.1 vs. 28.4 +/- 1.0 ml, P = 0.008) despite prolonged restoration of physiological testosterone concentrations. Neither modality of testosterone treatment nor type of hypogonadism influenced prostate zonal volumes before or after treatment. In contrast, central, peripheral and total prostate volume increased with age among healthy controls and men with androgen deficiency regardless of androgen replacement therapy. Plasma PSA concentrations were reduced in men with untreated androgen deficiency and were similar to age-matched controls in men with treated androgen deficiency.

CONCLUSIONS

We conclude that, during mid-life, chronic androgen deficiency due to hypogonadism is associated with reduced central, peripheral and total prostate volumes. Reduced prostate volumes persist even during long-term maintenance of effective androgen replacement therapy with physiological testosterone concentrations until the fourth decade of life. After that, prostate volumes increase with age regardless of androgen deficiency or replacement. These findings suggest that, during mid-life, age is a more important determinant of prostate growth than ambient testosterone concentrations maintained in the physiological range. The persistently subnormal prostate volumes despite adequate androgen replacement therapy may explain the apparent paucity of cases of overt prostate disease among testosterone-treated androgen deficient men who retain protection against prostate disease despite physiological androgen replacement therapy.

[Ligand of platelet and T cell activation antigen 1 (PTA1) expressed on Colo205 cell surface]

OBJECTIVE

To confirm the existence of PTA1 ligand (PTA1L).

METHODS

PTA1/Ig fusion protein was prepared by gene recombination and expression in COS-7 cells by DEAE-dextran transfection. The fusion protein was used as a probe in the investigation of PTA1L by immunohistochemical staining. Existence of PTA1L was further identified by adhesion experiment.

RESULTS

Colo205 cells could be stained by PTA1/Ig fusion protein specifically but not by hIg, and the adhesion of activated Jurkat cells with Colo205 could be blocked by PTA1/Ig and PTA1 mAb.

CONCLUSION

PTA1 ligand is present on the surface of Colo205 cells. These results provide a solid basis for further investigation of the role of PTA1-PTA1L interaction in the pathogenesis of neoplasm.

Increased expression of hepatic DNA methyltransferase in smokers

The DNA methyltransferase enzyme (DNA MTase) catalyzes DNA methylation at cytosines in CpG dinucleotides. 5-Methylcytosine modification of DNA is important in gene regulation, DNA replication, chromatin organization and disease. Increased levels of DNA MTase have been associated with the initiation and promotion of cancer. This study was conducted to assess whether cigarette smoking and other factors, such as age and gender, influence DNA MTase expression in nontumorous tissue. DNA MTase was significantly (p<0.05) higher in samples from cigarette smokers; the mean level of DNA MTase mRNA was almost 2-fold higher in these samples than in those from nonsmokers. Levels of DNA MTase mRNA were higher in samples from females than in those from males, but the difference was not statistically significant. Age was not associated with DNA MTase levels. Increased levels of DNA MTase in individuals who smoke may indicate a greater susceptibility to the risk of cancer since increased levels of this enzyme are found in cancer cell lines and human tumors. The results of this study suggest that further investigations of increased expression of this enzyme as a predisposing factor for cancer susceptibility are needed.

Synthesis of the apoptosis inducing agent apoptolidin. Assembly of the C(16)-C(28) fragment

[reaction--see text] A stereoselective synthesis of the C(16)-C(28) fragment of the apoptosis inducing agent apoptolidin is described. Key steps include two propionate aldol reactions and a stereoselective Mukaiyama aldol addition of enolsilane 19 to beta-methoxy aldehyde 4.

In vitro and in vivo m2 muscarinic subtype selectivity of some dibenzodiazepinones and pyridobenzodiazepinones

Alzheimer's disease (AD) involves selective loss of muscarinic m2, but not m1, subtype receptors in cortical and hippocampal regions of the human brain. Emission tomographic study of the loss of m2 receptors in AD has been limited by the absence of available m2-selective radioligands, which can penetrate the blood-brain barrier. We now report on the in vitro and in vivo m2 muscarinic subtype selectivity of a series of dibenzodiazepinones and pyridobenzodiazepinones determined by competition studies against (R)-3-quinuclidinyl (S)-4-iodobenzilate ((R,S)-[125I]IQNB) or [3H]QNB. Of the compounds examined, three of the 5-[[4-[(4-dialkylamino)butyl]-1-piperidinyl]acetyl]-10, 11-dihydro-5-H-dibenzo[b,e][1,4]diazepin-11-ones (including DIBA) and three of the 11-[[4-[4-(dialkylamino)butyl]-1-phenyl]acetyl]-5, 11-dihydro-6H-pyrido [2,3-b][1,4]benzodiazepin-6-ones (including PBID) exhibited both high binding affinity for the m2 subtype (</=5 nM) and high m2/m1 selectivity (>/=10). In vivo rat brain dissection studies of the competition of PBID or DIBD against (R,S)[125I]IQNB or [3H]QNB exhibited a dose-dependent preferential decrease in the binding of the radiotracer in brain regions that are enriched in the m2 muscarinic subtype. In vivo rat brain autoradiographic studies of the competition of PBID, BIBN 99, or DIBD against (R,S)[125I]IQNB exhibited an insignificant effect of BIBN 99 and confirmed the effect of PBID and DIBD in decreasing the binding of (R,S)[125I]IQNB in brain regions that are enriched in the m2 muscarinic subtype. We conclude that PBID and DIBD are potentially useful parent compounds from which in vivo m2 selective derivatives may be prepared for potential use in positron emission tomographic (PET) study of the loss of m2 receptors in AD.

Isolation of cDNAs encoding gibbon and monkey platelet and T cell activation antigen 1 (PTA1)

Human platelet and T cell activation antigen 1 (PTA1) is a 67kDa type I transmembrane glycoprotein mainly expressed on the surface of activated T cells and platelets, and is involved in the development of human cytotoxic T cell (CTL) as well as platelet activation and aggregation. We have cloned and sequenced gibbon PTA1 (gPTA1) and monkey PTA1 (mPTA1) cDNAs by RT-PCR from gibbon leukemic cell line MLA 144 and PHA-induced Rhesus monkey PBMC respectively. The mature proteins of gPTA1, mPTA1 and human PTA1 (hPTA1) share 93-95% amino acid similarity with the highest similarity in domain 1 of extracellular region. All the important features of PTA1 molecule are conserved among these Primates: (1) the ORF encoding 336 amino acid residues including signal sequence (18aa), extracellular region (232aa), transmembrane sequence (25aa) and cytoplasmic region (61aa); (2) two conserved pairs of Cys (Cys19 to Cys90 and Cys134 to Cys204) forming disulfide bonds stabilizing the two immunoglobulin superfamily V-like domains; (3) eight putative N-linked glycosylation sites (except gPTA1 with nine sites) and three O-linked glycosylation sites in extracellular region; and (4) predicated protein kinase C phosphorylation sites (Thr275 and Ser311), casein kinase II sites (Ser295 and The299) and the potential tyrosine phosphorylation site (Tyr304). These data indicate that PTA1 molecule is highly conserved among the Primates and may play important roles in immune response.

Synthesis of a polymeric 4-N-linked sialoside which inhibits influenza virus hemagglutinin

A multiple sialic acid-bearing polymer 7 has been made in which a novel 4-N-substituted sialoside 5 has been coupled to polyacrylamide. The conjugate 7 has been found to inhibit the agglutination of influenza virus to red blood cells with HAI inhibition constants of around 10(-6) M, based on the sialic acid concentration.

Androgen receptor gene polymorphism and prostate zonal volumes in Australian and Chinese men

Prostate diseases are age and androgen dependent. The evolution of clinically overt pathology requires decades of exposure to adult male levels of circulating testosterone, but the precise relationship between age and androgen circulation remains poorly understood. A marker of integrated androgen action over prolonged periods would therefore be a valuable tool for clinical and epidemiologic research into the origins of prostate disease. In order to evaluate these 2 factors, we have studied the CAG-repeat length polymorphism of the androgen receptor gene and the size of the total, central, and peripheral zones of the prostate, estimated by planimetric ultrasound in 2 populations with widely different susceptibility to death from invasive prostate cancer. From a larger epidemiologic study of the effects of ethnicity and migration on the origins of prostate disease, a nested-case control study was undertaken with 50 Chinese men living in Yue Yang, China and 50 non-Chinese men living in Sydney, Australia. All men had undergone planimetric transrectal prostate ultrasound together with blood sampling to determine CAG-repeat length by polymerase chain reaction and immunoassay of plasma testosterone, estradiol, dihydrotestosterone (DHT), sex hormone-binding globulin (SHBG), and prostate-specific antigen (PSA). Australian men had larger central (7.9 +/- 0.4 vs 3.3 +/- 0.3 mL) and total (29.8 +/- 1.2 vs 25.5 +/- 1.1 mL) but not peripheral (22.0 +/- 0.9 vs 22.2 +/- 0.8 mL) prostate volumes compared with Chinese men. Even after adjustment for differences in body size (the Australian men were taller and heavier), the central-zone volume remained lower by approximately 50% in Chinese men (P < 0.001), whereas testis and total-prostate volumes were no longer significantly different. The length of CAG repeats was no different between Australian men (22.5 +/- 0.5 repeats) and Chinese men (22.5 +/- 0.5 repeats), and there was no correlation within or between populations in CAG repeats or any measure of prostate volume or hormones. DHT concentration was 20% lower in Chinese men compared with Australian men (1.6 +/- 0.1 vs 2.0 +/- 0.1 nmol/L, P = 0.005), a difference that persisted after age adjustment (P = 0.039) but that was removed by adjustment for differences in total-prostate size (P = 0.12). Blood testosterone, estradiol, SHBG, and PSA concentrations were not different between the 2 populations. Hence, the hypothesis is refuted that the CAG repeat polymorphism in the androgen receptor gene (within the nonpathologic range) and the central-prostate zone volume might be markers of long-term androgen sensitivity. Whether either factor alone may constitute a marker of androgen sensitivity remains to be established by other means, and a long-term marker of integrated androgen action suitable for clinical and epidemiologic research is still lacking.

Ethnicity and migration as determinants of human prostate size

The roles of ethnicity and migration in determining the size of human prostate zones during midlife were explored. Prostate size was measured by planimetric ultrasound in 163 men residing in Sydney who were either Australian non-Chinese (AR; n = 116) or Chinese migrants (ACM; n = 47) and had lived in Australia for a median of 7.3 yr (range, 0.2-25 yr). These were compared with Chinese men residing in China (CR; n = 210). Central and total prostate volumes were estimated by a single observer using the same equipment at both sites. After adjustment for age, central and total prostate volumes were significantly smaller, and plasma prostate-specific antigen and 5alpha-dihydrotestosterone (DHT) concentrations and International Prostate Syndrome Scores were significantly lower, in CR compared with either ACM or AR, whereas the scores of the latter two groups were similar. Almost all of the population difference in total prostate volumes could be accounted for by differences in central prostate volumes. The strongest correlates of age-adjusted prostate volume were prostate-specific antigen and DHT, the latter presumably reflecting the quantitative importance of prostatic stromal type II 5alpha-reductase activity to circulating DHT concentrations. Sex hormone-binding globulin concentrations were significantly higher in CR and significantly lower in ACM compared with those in AR, but the significance of these observations is unclear. These findings highlight the importance of the central zone of the prostate as well as provide evidence for an environmental factor influencing prostate growth. This factor operates over a relatively short time period compared with the evolution of prostate disease. Hence, this study provides evidence that ethnicity and geographical factors, such as migration, can influence the growth of the normal human prostate during midlife and may facilitate future studies of the origins and pathogenesis of human prostate disease.

Increased expression of plasminogen activator and plasminogen activator inhibitor during liver fibrogenesis of rats: role of stellate cells

BACKGROUND/AIMS

Plasminogen activators and plasminogen activator inhibitors are important regulators of the balance between the proteolytic and antiproteolytic activities that determine extracellular matrix turnover. We examined the expression of plasminogen activator-plasmin system components in experimental liver fibrosis of rats.

METHODS

Liver fibrosis was produced in rats by injecting carbon tetrachloride for 6 to 12 weeks. Gene expression for plasminogen activator inhibitor-1 (PAI-1), urokinase and tissue plasminogen activators (uPA and tPA), urokinase plasminogen activator receptor (uPAR), and transforming growth factor-beta1 (TGF-beta1) was examined by Northern analysis. Western analysis was performed to detect protein expression of PAI-1, uPA and uPAR. An immunohistochemical study was performed to detect the localization of PAI-1. Additionally, primary cultured liver cells were examined by Northern and Western analyses for this protein with or without prior incubation with TGF-beta1.

RESULTS

At 6 weeks, when fibrosis had occurred, uPA and uPAR mRNAs had increased 2.8-fold and 1.8-fold, respectively; PAI-1 and tPA mRNA levels were unchanged. At the cirrhotic stage (9 to 12 weeks), mRNA levels for PAI-1, uPA, uPAR and tPA were all increased. Western analysis also showed increased uPA and uPAR expressions in fibrotic liver, and increased PAI-1, uPA and uPAR expressions in cirrhotic liver. PAI-1 protein was also demonstrated immunohistochemically along sinusoids, vessels, and bile duct cells of normal and fibrotic liver. In liver cell cultures, Kupffer cells, hepatocytes, and especially stellate cells, expressed PAI-1. Expression was enhanced in stellate cells cultured from fibrotic or cirrhotic liver or stimulated in vitro with TGF-beta1.

CONCLUSION

Though increased uPA and uPAR may act on matrix degradation in fibrotic liver, increased PAI-1 together with uPA, uPAR and tPA are associated with overall inhibition of matrix degradation in cirrhotic liver. Hepatic stellate cells are an important source of PAI-1 during liver fibrosis.

Preparation and characterization of monoclonal antibodies against GAM protein: a novel gp130-associated molecule

gp130-associated-molecule (GAM) is a recently cloned 24-kDa protein, which binds to gp130 at its cytoplasmic membrane-proximal region and has high homology with the N-terminal of Groucho/TLE molecules, a transcription co-repressor family playing an essential role in Notch signaling. Expression of GAM in COS7 cells inhibited the association of JAKs with gp130, and decreased the tyrosine phosphorylation level of these molecules as well. To further investigate the function of GAM, monoclonal antibodies (MAbs) to GAM were prepared. First, GAM-Thioredoxin(Thio) fusion protein was expressed in E. coli and purified with anti-Thio PAb coupled Sepharose-4B. Using purified GAM-Thio as immunogen, three MAbs against GAM with high affinity were raised by conventional B-lymphocyte hybridoma technique. They could recognize different epitopes of nature and denatured GAM-Thio without any cross-reaction with Thio or components of E. coli or with TLE1-GST fusion protein. In Western blotting and flow cytometric assay, these MAbs can detect cellular GAM protein and verify the increase of GAM expressing in GAM cDNA permanently transfected M1 cells. Furthermore, Western blotting with these MAbs indicated that GAM formed 110 kDa polymers in the nucleus. These MAbs represent powerful in investigating the role of GAM in gp130 signaling and Notch signaling.

Effects of liver disease and transplantation on the human prostate

A major determinant of late-life prostate diseases is hormonal exposure during earlier life, but the effects of androgens in midlife on the human prostate have been little studied. In order to identify hormonal effects on the prostate during the long latent period of midlife, we studied the effects of chronic androgen deficiency on the prostate during midlife by examining men with severe liver disease before and after liver transplantation. Patients (n = 15, median 57, range 38-65 years old) with severe liver disease but no known prostate disease being evaluated for liver transplantation underwent 21 prostate ultrasound studies, 12 prior to and 9 after liver transplantation, with six men undergoing both studies. Controls were 42 prostate ultrasound studies (2:1 matching) from age-matched healthy men. Total- and central-prostate volumes were measured with a 7.5-MHz biplane transducer planimetrically at 2.5-mm intervals with a stepper device from base to apex of the prostate. Overall, total- and central-prostate volumes were not significantly different between patients with chronic liver disease before and after liver transplantation and age-matched healthy controls. This appeared to be due to a bimodal distribution, with most men (12 men, 17 studies) having smaller prostate volumes and a minority (3 men, 4 studies) having previously undiagnosed, macroscopic, benign prostatic hyperplasia. The reduction in prostate volume prior to transplantation was significantly correlated with severity of liver disease (Child-Pugh score). Before liver transplantation, prostate-specific antigen (PSA) concentrations were significantly lower and prostatic acid phosphatase increased, and both were normalized after liver transplantation. Plasma testosterone concentrations were decreased before transplantation and remained low after transplantation. Sex hormone-binding globulin level was significantly elevated before and reduced to subnormal after liver transplantation. Estradiol concentrations were unchanged by liver disease or transplantation. We conclude that prostate volumes, particularly that of the central zone, are usually reduced by the functional androgen deficiency of chronic liver disease and tend to be restored toward normal by liver transplantation, depending on the degree of rectification of circulating plasma testosterone concentrations. Prostate glands with established benign prostatic hyperplasia may be less responsive to these hormonal changes.

Improved fusion partners transfected with DNA fragment encoding IL-11 on generation of human B lymphocyte hybridomas

IL-11, a less identified cytokine, possesses some overlapping functions with IL-6 that are able to facilitate the growth and antibody secretion of B lymphocyte hybridomas. In this report, a DNA fragment encoding human IL-11 was transduced into fusion partners (mouse myelomas Ag8.653 and SP2/0, and human lymphoblastoid cell line HF2) mediated by lipofection. The transfected cells selected with G418 secreted IL-11 constitutively over the range of 32.4 +/- 10.5 units/ml to 76.6 +/- 18.4 units/ml, which could be inhibited by an IL-11 neutralizing MAb up to 80%. The fusion frequency of PBMC doubled, while that of LCLs displayed a 2.4- or 3.3-fold increase, when fused with the transfected fusion partners, respectively. The derived hybridomas from IL-11 secreting fusion partner secreted 3 or 4 times as many immunoglobulins as that from its ancestor. Our data indicate that IL-11 gene transfected fusion partners are improved cell lines for generation of human B lymphocyte hybridomas, and IL-11 may contribute to the increased fusion frequency and antibody secretion of B lymphocyte hybridomas.

Spatial distribution of tissue inhibitor of metalloproteinase-1 mRNA in chronic liver disease

BACKGROUND/AIMS

Tissue inhibitor of metalloproteinase-1, a specific inhibitor of matrix metalloproteinases, plays an important role in the pathogenesis of fibrosis and tumor progression. However, the precise expression of tissue inhibitor of metalloproteinase-1 messenger RNA in human hepatic fibrosis has not yet been defined. We investigated the spatial distribution of tissue inhibitor of metalloproteinase-1 messenger RNA in chronic human liver disease.

METHODS

Northern and in situ hybridization of probes to tissue inhibitor of metalloproteinase-1 messenger RNA were performed in specimens from 16 surgically resected human livers. Immunohistochemical staining of sections for tissue inhibitor of metalloproteinase-1 and immunoelectron microscopy were also performed.

RESULTS

Northern hybridization demonstrated that expression of tissue inhibitor of metalloproteinase-1 messenger RNA was increased 3.9-fold in mild chronic hepatitis, 6.8-fold in moderate chronic hepatitis, and 6.4-fold in cirrhosis, compared with control liver. In situ hybridization showed the expression of tissue inhibitor of metalloproteinase-1 messenger RNA in spindle-shaped cells in the fibrous septa and lobules in chronic hepatitis and cirrhosis; these cells were immunohistochemically positive for a-smooth muscle actin. Immunoelectron microscopy revealed localization of tissue inhibitor of metalloproteinase-1 in between fibers, to the rough endoplasmic reticula of stellate cells located in the lobules and periportal areas, and to fibroblasts in the fibrous septa. These results indicate that tissue inhibitor of metalloproteinase-1 was produced mainly by stellate cells in the specimens of chronic liver diseases.

CONCLUSIONS

Expression of tissue inhibitor of metalloproteinase-1 messenger RNA is increased in hepatic fibrosis and stellate cells are involved primarily in its expression.

[PTA1 monoclonal antibody induces human platelet aggregation and intra-cytoplasmic Ca2+ elevation]

OBJECTIVE

To explore the mechanism of PTA1 monoclonal antibody (McAb) induced human platelet aggregation and its effect on intra-cytoplasmic Ca2+ level.

METHODS

Platelet aggregation, ATP releasing assay and Pollock's test were used.

RESULTS

PTA1 McAb induced human platelet aggregation in vitro, which could be completely inhibited by EGTA and PGI2. F(ab')2 of PTA1 McAb had no effect on CD9 or CD41 induced platelet activation and aggregation. PTA1 McAb enhanced platelet intra-cytoplasmic Ca2+ elevation.

CONCLUSION

PTA1 McAb inducing platelet aggregation is related to platelet Fc receptor and CD41/CD61 (II b/III a) complex, and the induced platelet intra-cytoplasmic Ca2+ elevation is resulted from Ca2+ influx and releasing of intracytoplasmic Ca2+ storage.

Dual expression of matrix metalloproteinase-2 and membrane-type 1-matrix metalloproteinase in fibrotic human livers

We have previously reported increased expression of matrix metalloproteinase-2 (MMP-2) using a rat model of liver fibrosis. However we did not clarify how the precursor of MMP-2 (proMMP-2) was activated. Therefore, we used human liver specimens with chronic hepatitis (CH) and liver cirrhosis (LC) to examine expression of membrane-type-1-MMP (MT1-MMP), which has recently been determined to activate proMMP-2. Northern hybridization studies showed a 5.4- and 1.4-fold increase in MMP-2 expression in CH and LC, respectively, as compared with normal liver. MT1-MMP gene expression simultaneously increased 4.0- and 1.4-fold in CH and LC, respectively. In situ hybridization using 35S-cRNA probes of MMP-2 and MT1-MMP showed prominent silver granules in elongated cells found in the lobules, periportal areas, and fibrous septa of CH and LC samples. These elongated cells expressed alpha-smooth muscle actin by immunohistochemistry. Immunoelectron microscopic examination localized MMP-2 and MT1-MMP to the rough endoplasmic reticulum of stellate cells located in the lobules and periportal areas, or to fibroblasts in the fibrous septa, suggesting that MMP-2 and MT1-MMP were produced by these cells. In addition, cytoplasmic and membranous immunodeposits of both MMPs were found in endothelial cells, Kupffer cells, capillary endothelial cells, and lymphocytes, indicating that activation of proMMP-2 occurs locally. Increased expression of MMP-2 and MT1-MMP was detected in CH and LC, while dual over-expression was found in stellate cells and fibroblasts, possibly resulting in the increase of active MMP-2 in and around these cells. These findings suggest that activated MMP-2 may remodel liver parenchyma during the process of liver fibrosis.