Increased central nervous system production of extracellular matrix components and development of hydrocephalus in transgenic mice overexpressing transforming growth factor-beta 1

A number of important neurological diseases, including HIV-1 encephalitis, Alzheimer's disease, and brain trauma, are associated with increased cerebral expression of the multifunctional cytokine transforming growth factor-beta 1 (TGF-beta 1). To determine whether overexpression of TGF-beta 1 within the central nervous system (CNS) can contribute to the development of neuropathological alterations, a bioactive form of TGF-beta 1 was expressed in astrocytes of transgenic mice. Transgenic mice with high levels of cerebral TGF-beta 1 expression developed a severe communicating hydrocephalus, seizures, motor incoordination, and early runting. While unmanipulated heterozygous transgenic mice from a low expressor line showed no such alterations, increasing TGF-beta 1 expression in this line by injury-induced astroglial activation or generation of homozygous offspring did result in the abnormal phenotype. Notably, astroglial overexpression of TGF-beta 1 consistently induced a strong upmodulation of the extracellular matrix proteins laminin and fibronectin in the CNS, particularly in the vicinity of TGF-beta 1-expressing perivascular astrocytes, but was not associated with obvious CNS infiltration by hematogenous cells. While low levels of extracellular matrix protein expression may assist in CNS wound repair and regeneration, excessive extracellular matrix deposition could result in the development of hydrocephalus. As an effective inducer of extracellular matrix components, TGF-beta 1 may also contribute to the development of other neuropathological alterations, eg, the formation of amyloid plaques in Alzheimer's disease.

Accumulation of extracellular matrix and developmental dysregulation in the pancreas by transgenic production of transforming growth factor-beta 1

Transgenic mice expressing transforming growth factor-beta 1 (TGF-beta 1) in the pancreatic beta-islet cells directed by human insulin promoter were produced to study in vivo effects of TGF-beta 1. Fibroblast proliferation and abnormal deposition of extracellular matrix were observed from birth onward, finally replacing almost all the exocrine pancreas. Cellular infiltrates comprising macrophages and neutrophils were also observed. Plasminogen activator inhibitor was induced in the transgenic pancreas as well as fibronectin and laminin, partly explaining accumulation of extracellular matrix. TGF-beta 1 inhibited proliferation of acinar cells in vivo as evidenced by decreased bromodeoxyuridine incorporation. Development of pancreatic islets was dysregulated, resulting in small islet cell clusters without formation of normal adult islets; however, the overall islet cell mass was not significantly diminished. Additional transgenic lines with less pronounced phenotypes had less expression of TGF-beta 1 transgene. These findings suggest that TGF-beta 1 might be a mediator of diseases associated with extracellular matrix deposition such as chronic pancreatitis, and this mouse model will be useful for further analysis of the in vivo effects of TGF-beta 1, including its potential for immunosuppression.

Differentiating neurons activate transcription of the brain lipid-binding protein gene in radial glia through a novel regulatory element

Formation and maintenance of a radial glial scaffold is fundamental for development of the vertebrate central nervous system. In mammals, radial glia arise in the neuroepithelium immediately prior to differentiation and migration of neurons away from the ventricular zones, and they are maintained until neuronal migration subsides. We have previously shown that expression of the brain lipid-binding protein (BLBP) in radial glia throughout the developing CNS is strictly correlated with the differentiation and migration of neurons upon these cells, and that BLBP function is required to maintain differentiation of primary cerebellar glial cells in vitro (Feng, L., Hatten, M. E. and Heintz, N. (1994). Neuron 12, 895–908). In this study, we demonstrate that BLBP transcription in vivo involves multiple regulatory elements, and that the dynamic temporal and spatial pattern of BLBP expression in radial and Bergmann glial cells throughout the developing CNS is programmed by a single radial glial cell-specific element (RGE). Furthermore, we demonstrate that BLBP expression in primary cerebellar glial cells requires coculture with differentiating neurons, and that this induction is regulated by the radial glia-specific element. The fact that transcription of BLBP in response to neurons in vitro and its dynamic regulation in radial glia throughout the CNS in vivo are both controlled by the RGE provides the first direct evidence supporting a role for differentiating neurons in the epigenetic regulation of radial glial cell function in vivo.

Expression of neurofilament proteins during retinoic acid-induced differentiation of P19 embryonal carcinoma cells

Retinoic acid (RA) induces P19 embryonal carcinoma cells to differentiate into neurons with the extension of neuritic processes. We used the P19 cell as a model system to elucidate the regulation of neurofilament (NF) expression. Four mammalian NF proteins, NF-66 (alpha-internexin), peripherin, NF-L and NF-M, and the neural-specific, growth-associated gene, GAP-43, were studied during the RA treatment of P19 cells in vitro. As controls, untreated P19 cells were maintained in parallel. Indirect immunofluorescent staining showed that in RA-treated, morphologically differentiated P19 cells NF-66 was expressed in neuron-like cells characterized by phase bright cell bodies and long neuritic processes. At various times P19 cells were harvested for protein analysis by immunoblotting with antibodies to individual NF proteins or for total RNA extraction and Northern blotting with cDNA probes for NF-66, -L, -M, peripherin and GAP-43. During induction, both NF-66 and NF-L were expressed but in distinct patterns. NF-66 mRNA and protein were detected after 6 days of induction. In contrast, NF-L mRNA, but not protein, was expressed in both induced and control cells. Neither NF-M nor peripherin were expressed during induction. During differentiation of P19 cells, NF-66 mRNA levels rose markedly by the 1st day, reached a plateau between the 3rd-5th days and declined by the 7th day. NF-66 protein accumulation lagged slightly, reaching maximum abundance about the 5th day. The kinetics of NF-66 expression were similar to that of GAP-43. However, the pattern of NF-L expression was distinct from that of NF-66. NF-L mRNA, and some protein, was expressed in both RA-treated and control cells within 6 h after plating, but was down-regulated to baseline level thereafter in both populations. Neither NF-M or peripherin expression was detected during the differentiation. In summary, NF-66 was up-regulated most robustly among the four NF proteins during differentiation in P19 cells and was the major NF protein correlated with neurite extension.

The lurcher gene induces apoptotic death in cerebellar Purkinje cells

In the neurologically mutant mouse strain lurcher (Lc), heterozygous animals display cell autonomous degeneration of cerebellar Purkinje cells beginning in the second postnatal week. During the course of our studies to identify the genetic lesion responsible for this disease (Norman et al., 1991), we have formulated an hypothesis suggesting that in Lc Purkinje cells homeostasis is sufficiently perturbed to lead to the activation of programmed cell death, thus resulting in neuronal loss and the consequent neurologic disease (Heintz, 1993). To address this possibility, we have examined the properties of Lc Purkinje cells as they die during the second postnatal week. Our light and electron microscopic studies demonstrate that dying Lc Purkinje cells exhibit the characteristic morphologic features of apoptosis, including nuclear condensation, axon beading and membrane blebbing. Using an in situ end-labeling method, we have also detected nicked nuclear DNA in these cells. Furthermore, we have examined the expression of the sulfated glycoprotein 2 (SGP2), whose mRNA is induced in both T-cells and prostate epithelial cells undergoing apoptotic death. We show by in situ hybridization that SGP2 is not expressed at detectable levels in normal Purkinje cells, but that its mRNA is present in Lc Purkinje cells prior to their death. Also expression of the Kv3.3b potassium channel, which marks the terminal phase of Purkinje cell differentiation, is evident in Lc Purkinje cells prior to their death. These data demonstrate that the Lc mutation induces apoptosis in cerebellar Purkinje cells following their maturation in postnatal cerebellum. Isolation of the Lc mutation and further analysis of its action in eliciting apoptosis can provide an important opportunity for understanding the etiology of neurodegenerative disease.

Involvement of reactive oxygen intermediates in cyclooxygenase-2 expression induced by interleukin-1, tumor necrosis factor-alpha, and lipopolysaccharide

Reactive oxygen intermediates (ROIs) play an important role in inflammatory processes as mediators of injury and potentially in signal transduction leading to gene expression. Cyclooxygenase (COX) is a rate-limiting enzyme in prostanoid biosynthesis, and its recently cloned inducible form, COX-2, is induced by proinflammatory cytokines. This study linked ROIs to the signaling pathways that induce COX-2 expression. The hydroxyl radical scavengers DMSO (1%), as well as di- and tetramethylthiourea, inhibited IL-1-, TNF alpha-, and LPS-induced COX-2 expression in rat mesangial cells. The suppression of COX-2 mRNA expression correlated with the COX-2 protein level. In comparison with the prolonged induction of the inducible gene encoding protein-tyrosine phosphatase by hydrogen peroxide, the COX-2 gene was only transiently induced. Protein-tyrosine phosphatase is also induced by heat shock and chemical stress, whereas COX-2 is not. Superoxide was a more potent inducer for COX-2 than hydrogen peroxide. In addition, NADPH stimulated COX-2 expression, and an inhibitor of NADPH oxidase blocked COX-2 expression induced by TNF alpha. COX-2 and KC gene expression costimulated by IL-1 were inhibited differentially by the scavengers. These studies demonstrate that oxidant stress is a specific and important inducer of COX-2 gene expression. This induction may contribute to the deleterious amplification of prostanoids in inflammation and compound the direct effects of ROI production.

Radicicol, a protein tyrosine kinase inhibitor, suppresses the expression of mitogen-inducible cyclooxygenase in macrophages stimulated with lipopolysaccharide and in experimental glomerulonephritis

Two isoforms of cyclooxygenase (COX) have been identified in eukaryotic cells: a constitutively expressed COX-1 and mitogen-inducible COX-2, which is selectively expressed in response to various inflammatory stimuli. Thus, COX-2 instead of COX-1 is implicated to produce prostanoids mediating inflammatory responses. Major efforts have been focused on identifying nonsteroidal anti-inflammatory drugs (NSAIDS) which can selectively inhibit the enzyme activity of COX-2. Such NSAIDS would be more desirable anti-inflammatory agents in comparison to NSAIDS which inhibit both COX-1 and COX-2. Other than glucocorticoids, pharmacological agents which can selectively suppress the expression of COX-2 without affecting that of COX-1 have not been identified. We report here that radicicol, a fungal antibiotic, is a potent protein tyrosine kinase inhibitor, and that it inhibits the expression of COX-2 without affecting COX-1 expression in lipopolysaccharide (LPS)-stimulated macrophages with the IC50 value of 27 nM. Radicicol inhibited tyrosine phosphorylation of p53/56lyn, a Src family tyrosine kinase and one of the major tyrosine-phosphorylated proteins in LPS-stimulated macrophages. Radicicol also inhibited COX-2 expression in vivo in glomeruli of rats with experimental glomerulonephritis induced by the anti-glomerular basement membrane antibodies, in which COX-2 expression is known to be enhanced. The enzyme activity of COX-1 or COX-2 was not affected by radicicol in macrophages. Radiciciol also suppressed the COX-2 expression induced by IL-1 beta in rat smooth muscle cells. Other protein tyrosine kinase inhibitors suppressed the LPS-induced COX-2 expression in macrophages but at much higher concentrations than needed for radicicol. Radicicol did not inhibit the COX-2 expression induced by phorbol 12-myristate 13-acetate in macrophages. These results suggest that the activation of tyrosine-specific protein kinases is the proximal obligatory step in the LPS-induced signal transduction pathway leading to the induction of COX-2 expression in macrophages. The magnitude of the inhibition of COX-2 protein synthesis by radicicol was much greater than that of the steady state levels of COX-2 mRNA. These results suggest that radicicol inhibits COX-2 expression mainly at post-transcriptional steps.

Modulation of neutrophil influx in glomerulonephritis in the rat with anti-macrophage inflammatory protein-2 (MIP-2) antibody

The role of the chemokine, macrophage inflammatory protein-2 (MIP-2), during anti-glomerular basement membrane (GBM) antibody (Ab) glomerulonephritis (GN) was studied. Rat MIP-2 cDNA had been cloned previously. Recombinant rat MIP-2 (rMIP-2) from Escherichia coli exhibited neutrophil chemotactic activity and produced neutrophil influx when injected into the rat bladder wall. By using a riboprobe derived from the cDNA and an anti-rMIP-2 polyclonal Ab, MIP-2 was found to be induced in glomeruli with anti-GBM Ab GN as mRNA by 30 min and protein by 4 h, with both disappearing by 24 h. The expression of MIP-2 correlated with glomerular neutrophil influx. A single dose of the anti-MIP-2 Ab 30 min before anti-GBM Ab was effective in reducing neutrophil influx (40% at 4 h, P < 0.01) and periodic acid-Schiff deposits containing fibrin (54% at 24 h, P < 0.01). The anti-rMIP-2 Ab had no effect on anti-GBM Ab binding (paired-label isotope study). Functional improvement in the glomerular damage was evidenced by a reduction of abnormal proteinuria (P < 0.05). These results suggest that MIP-2 is a major neutrophil chemoattractant contributing to influx of neutrophils in Ab-induced glomerular inflammation in the rat.

[Effect of NMBzA on the oncogene and multiple tumor suppressor genes in monkey esophageal epithelium]

Mutations of ras oncogene and multiple tumor suppressor genes p53, Rb and APC in esophageal epithelium of rhesus monkey fed with one dose of N-methyl-N-benzylnitrosamine (NMBzA 30mg/kg), which was found in high incidence areas of esophageal cancer in China, were analysed by PCR and direct sequencing. Mutation at codon 12 of Ha-ras gene was not found in esophageal epithelium of monkey fed with NMBzA. Some mutations of p53 gene were found in esophageal epithelium of monkey after being fed with NMBzA for 24-48 hours. Some mutation of Rb and APC were found in esophageal epithelium of monkey after being fed with NMBzA for 48 hours. The mutation fingerprints of these genes disappeared in esophageal epithelium of monkey after being fed with NMBzA for 5 days. The results demonstrated that chemical carcinogen NMBzA can induce mutations of multiple tumor suppressor genes in monkey (in vivo) and indicated that the alteration of tumor suppressor genes in the initial stage of carcinogenesis needs many hits by chemical carcinogen. These alterations of p53, Rb, APC genes were similar to the changes of these genes in some reported previously primary esophageal cancer.

Reduction of ryanodine binding and cytosolic Ca2+ levels in liver by the immunosuppressant FK506

The mechanism of action of the immunosuppressant FK506 in the liver was studied. The hypothesis was tested that FK506 exerts its effect in the liver by interacting with the ryanodine-binding Ca2+ release channel. Two types of experiments were carried out: (1) [3H]-ryanodine binding studies with isolated microsomal fractions, and (2) cytosolic-free Ca2+ ([Ca2+]i) measurements with the intracellular Ca(2+)-indicator fura-2. The inclusion of FK506 in the incubation medium significantly decreased the binding of [3H]-ryanodine to liver microsomes. The Bmax of binding in control experiments was 405 fmol/mg protein; the presence of FK506 decreased the Bmax to 157 fmol/mg protein. Measurements of [Ca2+]i in the presence and absence of FK506 showed a decrease in [Ca2+]i in the presence of FK506. The data support the notion that FK506 interacts with the ryanodine binding Ca2+ channel in the liver and suggest a critical role for the ryanodine-binding Ca2+ channel in the hepatic responses to FK506. The interaction between FKBP-12 (FK506 binding protein) and the ryanodine-binding Ca2+ channel may be an essential link in the chain of events by which FK506 alters Ca(2+)-dependent cellular processes.

Kinetics of macrophage subpopulations and expression of monocyte chemoattractant protein-1 (MCP-1) in bleomycin-induced lung injury of rats studied by a novel monoclonal antibody against rat MCP-1

We investigated the kinetics of macrophage subpopulations and the expression of monocyte chemoattractant protein 1 (MCP-1) in a rat model of bleomycin-induced lung injury. Rat macrophage subpopulations were examined by immunohistochemistry using various anti-rat macrophage monoclonal antibodies (mAbs) and their proliferative capacity by [3H]thymidine (3HTdR) autoradiography. To detect the localization of expressed MCP-1, we generated an mAb against rat MCP-1 for immunohistochemical staining. Expression of MCP-1 messenger RNA (mRNA) was detected by Northern blot hybridization. Shortly after intratracheal instillation of bleomycin, the number of exudate macrophages recognized by mAb TRPM-3 increased in the injured lungs, peaked 3 days later, and decreased thereafter, whereas tissue macrophages identified by mAb ED2 increased slowly and peaked 2 weeks after instillation. Northern blot analysis disclosed that the expression of MCP-1 mRNA in the lung was most prominent 1 day after instillation and declined thereafter, preceding the numerical change of the TRPM-3-positive exudate macrophages. Immunohistochemistry with anti-rat MCP-1 revealed that the main sources of MCP-1 production were alveolar and interstitial macrophages and polymorphonuclear leukocytes. Based on these results, MCP-1 produced by polymorphonuclear leukocytes and by alveolar and interstitial macrophages is thought to induce the infiltration of blood monocytes, and infiltrated exudate macrophages produce MCP-1 to enhance subsequent accumulation of macrophages. In contrast, the expression of MCP-1 did not correlate with the numerical changes of the ED2-positive macrophages.

Changes in 1,4,5-inositol trisphosphate binding following partial hepatectomy

Hepatic parenchymal cells possess two receptors for 1,4,5-trisphosphate, one isolated with the plasma membrane fraction and another isolated with the nuclear fraction. Their interaction with antibodies generated against the receptor in the cerebellum indicates that these two receptor proteins are different. The potential involvement of the nuclear receptor in rapid cell proliferation was tested by measuring [3H]-IP3 binding, following partial hepatectomy. In nuclear fractions isolated 18 hours after the operation, a 33% decline in binding sites was detected. In nuclear fractions isolated 30 hours after the operation, a 60% decline in the binding sites was detected, but the Kd remained unchanged. A 70% decrease in binding sites was also detected in the plasma membrane fraction. These results show that partial hepatectomy is associated with a parallel loss of receptor sites in the nuclear and plasma membrane fractions.

A strategy for the analysis of gene expression during neural development

The delineation of cis-acting elements regulating stage-specific gene expression has played a critical role in the definition of the transcriptional circuitry regulating differentiation. In complex tissues such as the central nervous system, differentiation often requires temporally and spatially dynamic epigenetic cues that cannot be reproduced in cell culture. In these cases, identification of critical regulatory sequences and subsequent characterization of cognate transcription factors have been limited by lack of a rapid and efficient assay system for gene expression. We report a methodology that combines particle-bombardment transfection procedures and organotypic slice culture techniques to provide an acute assay system for transcriptional control in the developing central nervous system. Using this system, we demonstrate that cell-specific regulation of the brain lipid-binding protein (BLBP) gene in Bergmann glia, astrocytes, and migrating granule cells is conferred by 1.7 kb of 5' flanking sequences and that Purkinje cell-specific expression of the calbindin D28k gene in cerebellar cortex can be achieved with 1.1 kb of flanking DNA. Nearly 100% cotransfection of multiple DNAs can be achieved, allowing the design of precisely internally controlled experiments and providing the potential for rapid and efficient genetic analysis of gene function in single cells in a wild-type environment.

Insect resistance of transgenic plants that express modified Bacillus thuringiensis cryIA(b) and cryIC genes: a resistance management strategy

Tobacco and tomato plants were generated exhibiting insect resistance due to the introduction of modified cryIA(b) and cryIC genes of Bacillus thuringiensis. Limited modifications at selected regions of the coding sequences of both genes are sufficient to obtain resistance against Spodoptera exigua, Heliothis virescens and Manduca sexta. The criteria used to modify both genes demonstrate that the removal of sequence motifs potentially resulting in premature polyadenylation and transcript instability causes increased insect resistance. The expression of a cryIC-cryIA(b) fusion resulting in protection against S. exigua, H. virescens and M. sexta demonstrates the potential of expressing translational fusions, not only to broaden the insect resistance of transgenic plants, but also to simultaneously employ different gene classes in resistance management strategies.

Casein kinase II mediates multiple phosphorylation of Saccharomyces cerevisiae eIF-2 alpha (encoded by SUI2), which is required for optimal eIF-2 function in S. cerevisiae

Previous studies have demonstrated that the alpha subunit of eukaryotic initiation factor 2 (eIF-2 alpha), encoded by the SUI2 gene in the yeast Saccharomyces cerevisiae, is phosphorylated at Ser-51 by the GCN2 kinase in response to general amino acid control. Here we describe that yeast eIF-2 alpha is a constitutively phosphorylated protein species that is multiply phosphorylated by a GCN2-independent mechanism. 32Pi labeling and isoelectric focusing analysis of a SUI2+ delta gcn2 strain identifies eIF-2 alpha as radiolabeled and a single isoelectric protein species. Treatment of SUI2+ delta gcn2 strain extracts with phosphatase results in the identification of three additional isoelectric forms of eIF-2 alpha that correspond to the stepwise removal of three phosphates from the protein. Mutational analysis of SUI2 coupled with biochemical analysis of eIF-2 alpha maps the sites to the carboxyl region of SUI2 that correspond to Ser residues at amino acid positions 292, 294, and 301 that compose consensus casein kinase II sequences. 32Pi labeling or isoelectric focusing analysis of eIF-2 alpha from conditional casein kinase II mutants indicated that phosphorylation of eIF-2 alpha is abolished or dephosphorylated forms of eIF-2 alpha are detected when these strains are grown at the restrictive growth conditions. Furthermore, yeast casein kinase II phosphorylates recombinant wild-type eIF-2 alpha protein in vitro but does not phosphorylate recombinant eIF-2 alpha that contains Ser-to-Ala mutations at all three consensus casein kinase II sequences. These data strongly support the conclusion that casein kinase II directly phosphorylates eIF-2 alpha at one or all of these Ser amino acids in vivo. Although substitution of SUI2 genes mutated at these sites for the wild-type gene have no obvious effect on cell growth, one test that we have used appears to demonstrate that the inability to phosphorylate these sites has a physiological consequence on eIF-2 function in S. cerevisiae. Haploid strains constructed to contain Ser-to-Ala mutations at the consensus casein kinase II sequences in SUI2 in combination with a mutated allele of either the GCN2, GCN3, or GCD7 gene have synthetic growth defects. These genetic data appear to indicate that the modifications that we describe at the carboxyl end of the eIF-2 alpha protein are required for optimal eIF-2 function in S. cerevisiae.

Expression of mRNA for natriuretic peptide receptor subtypes in bovine kidney

The localization of mRNA for atrial natriuretic peptide (ANP) receptor subtypes (A, B, C) in the kidney was examined. Quantitative analysis of the ribonuclease protection assay showed that the numbers of type A receptor (ANPRA) mRNA were 6.9 x 10(7) in the glomeruli and 10.4 x 10(7) molecules/micrograms of total RNA in the inner medulla, and that of type C receptor (ANPRC) mRNA was 21.7 x 10(7) molecules/micrograms of total RNA in the glomeruli. The type B receptor (ANPRB) mRNA was present in smaller numbers (4.5-4.9 x 10(6) molecules/micrograms of total RNA) evenly throughout the kidney fractions. In situ hybridization demonstrated both ANPRA and ANPRC mRNA selectively in the glomerular epithelial cells and ANPRA mRNA in the collecting duct cells of the inner medulla. ANPRC was also localized on the foot processes of glomerular epithelial cells by immunohistochemistry using a specific antibody against the receptor. These results indicate that ANPRA is the major biologically active receptor for the ANP family of hormones in the kidney and is present selectively on the glomerular epithelial cells and inner medullary collecting duct cells. These cells are presumed to play a role in the regulation of glomerular filtration rate and sodium excretion induced by the family of ANP.

Protein adsorption on low-temperature isotropic carbon: I. Protein conformational change probed by differential scanning calorimetry

This is the first of a set of articles on protein adsorption on low-temperature isotropic carbon (LTIC), a reputed blood compatible material. Surface-induced conformational changes of albumin, fibrinogen, and some small proteins were measured by differential scanning calorimetry (DSC) on LTIC powders and colloidal silica. The LTIC surface significantly alters the DSC response (denaturation?) in proteins studied in different buffer solutions. We use the term "denaturation" to refer to altered protein behavior in the adsorbed state. Hydrophobic interactions between LTIC and the proteins are thought to be the major driving force. The presence of air at the water-carbon interface seems to prevent the surface denaturation of fibrinogen. The silica surface greatly denatures albumin but only slightly denatures fibrinogen. Because LTIC is considered to be a nonthrombogenic material, but silica is considered to be a thrombogenic one, whether a surface denatures adsorbed proteins cannot be the sole criterion for its blood compatibility. The latter largely depends on what protein the surface denatures, and in what sequences.

Cytokine expression, upregulation of intercellular adhesion molecule-1, and leukocyte infiltration in experimental tubulointerstitial nephritis

BACKGROUND

Cytokines are intercellular polypeptide messengers that mediate immune and inflammatory responses. The temporal profile of interleukin-1 beta (IL-1 beta), IL-6, tumor necrosis factor alpha (TNF-alpha), and monocyte chemotactic protein 1 (MCP-1) expression was examined in anti-tubular basement membrane (TBM) antibody-associated tubulointerstitial nephritis (TIN).

EXPERIMENTAL DESIGN

TIN was induced by immunization of Brown Norway rats with bovine cortical TBM, whereas control rats received ovalbumin. Whole kidney RNA was assessed with the RNase protection assay 3, 7, 8, 9, 10, 12, and 14 days after immunization. Cytokine mRNA expression was correlated with TNF-alpha bioactivity, renal intercellular adhesion molecule-1 expression, and CD18-positive leukocyte infiltration by immunohistochemistry.

RESULTS

Increased IL-1 beta, TNF-alpha, and MCP-1 mRNA relative to glyceraldehyde-3-phosphate dehydrogenase appeared on day 7 when TIN involved 10 to 40% of the cortex, and peaked rapidly on day 8 when there was 60 to 80% cortical involvement (at which time 75 to 80% of the infiltrating cells were neutrophils). The increase in TNF-alpha mRNA correlated with increased bioactivity. The influx of mononuclear cells on day 8 was preceded by the expression of MCP-1 mRNA. The infiltrating leukocytes expressed the leukocyte beta 2-integrin (CD18) and were found in areas with increased intercellular adhesion molecule-1 expression. The mRNAs for IL-1 beta, TNF-alpha, and MCP-1 were undetectable by day 10 (at which time 95% of the infiltrating cells were mononuclear). An increase in IL-1 receptor antagonist mRNA paralleled those of IL-1 beta. The expression of IL-6 mRNA was similar to that for IL-1, except that it disappeared by day 9.

CONCLUSIONS

There is a temporal association in the expression of IL-1 beta, TNF alpha, MCP-1, and IL-6 with the upregulation of intercellular adhesion molecule-1 and leukocyte infiltration within the tubulointerstitium in anti-TBM antibody-associated TIN. The narrow window of time through which these cytokines are expressed and the coincidence of their peak expression on day 8 suggest complex cytokine interactions in the pathogenesis of anti-TBM antibody TIN.

Embryonic neurons of the developing optic chiasm express L1 and CD44, cell surface molecules with opposing effects on retinal axon growth

The first retinal ganglion cell axons arriving at the embryonic mouse ventral diencephalon encounter an inverted V-shaped neuronal array defining the midline and posterior boundaries of the future optic chiasm. These neurons express L1, an immunoglobulin superfamily molecule known to promote retinal axon outgrowth, and CD44, a cell surface molecule that we find inhibits embryonic retinal axon growth in vitro. Incoming retinal axons do not penetrate this L1/CD44 neuron array, but turn to establish the characteristic X-shaped optic chiasm along the anterior border of this array. These results suggest that L1/CD44 neurons may serve as an anatomical template for retinal axon pathways at the embryonic mouse ventral diencephalon.

Interleukin-1 alpha stimulates KC synthesis in rat mesangial cells: glucocorticoids inhibit KC induction by IL-1

To assess the possible role of the production of chemokines by intrinsic glomerular cells in the generation of inflammation in glomerulonephritis, the chemokine, KC, was cloned from a rat macrophage cDNA library. Transfection of rat KC into COS-7 cells resulted in increased neutrophil chemotactic activity. The KC cDNA was expressed as a fusion protein in Escherichia coli for generation of an antibody. By using a riboprobe derived from the cDNA and the antibody, interleukin-1 (IL-1) was found to induce the expression of KC in rat mesangial cells. The induction of KC by IL-1 could be inhibited by dexamethasone (DEX). The protein synthesis inhibitor cycloheximide reversed the DEX-mediated inhibition, which suggested that new protein synthesis was necessary for the inhibitory effect. A nuclear runoff analysis indicated that DEX inhibited the transcription of KC induced by IL-1. The stability of KC mRNA was not decreased in the presence of DEX. Furthermore, immunoblots showed that DEX also inhibited KC expression at the level of translation. Together the inhibition of transcription and translation of the KC gene by DEX contribute to decreased KC expression in mesangial cells. The finding that mesangial cells express KC in response to proinflammatory cytokines, such as IL-1, points to a central role for the mesangial cell as a chemotactic source in glomerular inflammation.

Protein adsorption on low temperature isotropic carbon. III. Isotherms, competitivity, desorption and exchange of human albumin and fibrinogen

In this paper we consider the adsorption of albumin and fibrinogen on low temperature isotropic carbon (LTIC). A subsequent paper considers the adsorption of other plasma proteins [Feng L, Andrade JD, Colloids and Surfaces (in press)]. Carbon fragments and silica plates were used as adsorbents. Adsorption was carried out by incubating the adsorbents in solutions of 125I-labelled and unlabelled proteins (single component system), or with buffer-diluted human plasma (multicomponent system). Adsorbed proteins then underwent displacement by buffer, by single protein solutions or by dilute plasma. Results show that the LTIC substrate adsorbs a large amount of proteins before saturation, which may be due to multilayer adsorption. LTIC also irreversibly holds adsorbed proteins against the exchange agents used; little adsorbed proteins can be displaced, even after a very short adsorption time. There is no preferential adsorption for either albumin or fibrinogen on LTIC from their binary solutions, suggesting that both proteins have high affinities for the surface. Such strong interactions between LTIC and proteins are not attributed to electrostatic interactions. On the other hand, protein adsorption on the silica surface is selective and reversible, with a much higher affinity for fibrinogen than albumin and an even higher affinity for some other plasma proteins. The paper also discusses the effect of sequential protein addition to a solution on the surface concentration and suppression of adsorption of both proteins in the presence of other plasma proteins. A very important conclusion is that the LTIC surface is very active towards proteins adsorption.

Extracellular matrix accumulation in immune-mediated tubulointerstitial injury

The accumulation of excessive extracellular matrix (ECM) following tubular injury likely represents an imbalance between ECM production and degradation. We assessed the temporal relationship between the accumulation of ECM, cell adhesion molecules, matrix degrading proteinases, and their inhibitors in a rat model of anti-tubular basement membrane (TBM) antibody-associated tubulointerstitial nephritis (TIN) by the RNase protection assay and immunohistochemistry. There was an increase in the steady state expression of fibronectin (FN) and alpha 2(IV) collagen mRNAs beginning on day 7 with the onset of neutrophil infiltration. An increase in alpha 1(III) collagen and alpha 1-integrin did not occur until days 9 and 10, respectively, at which time mononuclear leukocytes were the predominant infiltrating cell. Increased levels of FN, alpha 1(III), alpha 2(IV) and alpha 1-integrin mRNAs occurred through day 14. By immunohistochemistry, increased accumulation of collagen IV, heparan sulfate proteoglycan, and laminin were detected along the thicken TBM; collagens I and III were immunolocalized within the tubulo-interstitium, while FN was present in both the TBM and interstitium in rats with TIN on day 14. The increase in matrix accumulation was associated with little or no increase in proteinases. u-PA transcripts fell beginning on day 8, with recovery to control values by day 12. Transin mRNA was found at low levels only on days 8 and 9, and the protein could not be detected by Western blotting. In contrast, these changes were associated with an increase in proteinase inhibitors, so that TIMP and PAI-1 mRNAs increased beginning on day 7 and persisted through day 14.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain lipid-binding protein (BLBP): a novel signaling system in the developing mammalian CNS

Using a polyclonal antibody against postnatal cerebellar cells, we have isolated a new, brain-specific member of the lipid-binding protein family (BLBP). Members of this family, such as cellular retinoic acid-binding protein, have been shown to carry small hydrophobic signaling molecules between cellular compartments. The expression of BLBP is spatially and temporally correlated with neuronal differentiation in many parts of the mouse CNS, including postnatal cerebellum, embryonic spinal cord, and cerebral cortex. In situ hybridization and immunocytochemistry show that BLBP is transiently expressed in radial glia in both the embryonic ventricular zone and the postnatal cerebellum. Subcellular localization studies by immunoelectron microscopy demonstrate that BLBP is present in the nucleus as well as the cytoplasm. Affinity-purified anti-BLBP antibodies block glial and neuronal differentiation in primary cell cultures, but have no effect on cell proliferation or adhesion. Based on these results, we propose that BLBP is required for the establishment of the radial glial fiber system in developing brain, a system that is necessary for the migration of immature neurons to establish cortical layers.

Adenovirus type 12 early region 1A expresses a 52R protein repressing the trans-activating activity of transcription factor c-Jun/AP-1

Oncoproteins of the early transcription unit 1A (E1A) of adenoviruses (Ad) are known to modulate the expression of all viral and of a variety of cellular genes. In this communication we present data demonstrating for the first time an activity associated with a protein (the 52R protein) expressed exclusively from E1A of the highly oncogenic subtype Ad12. The 52R protein, which does not contain any of the conserved regions (CR1-CR3) necessary for the trans-regulatory functions of the larger E1A proteins (266R, 235R), represses the trans-activating activity of the transcription factor c-Jun/AP-1. The repression of c-Jun/AP-1 activity is neither due to a down-regulation of the c-jun transcription rate nor due to an inhibition of binding of the transcription factor complex to its target sequence, at least under the conditions of in vitro band shift assays. As the 52R protein is most probably not associated with DNA-bound c-Jun/AP-1, we suppose that it represses c-Jun activity either by a squelching mechanism sequestering a cofactor, which is an essential link between c-Jun/AP-1 and the components of the basal transcriptional machinery or by modifying post-translational modifications necessary for the trans-activation function of c-Jun.

Alternative splicing of the NC1 domain of the human alpha 3(IV) collagen gene. Differential expression of mRNA transcripts that predict three protein variants with distinct carboxyl regions

Three clones of NC1 of alpha 3(IV) collagen, named Q1, L5, and V, were isolated from human kidney; these predict three variant alpha 3(IV) NC1 domains of 232-, 60-, and 199-amino acid residues, respectively, with unique COOH-termini. The human collagen IV gene (COL4A3) was isolated and characterized, and it was shown that the cDNA variants arose from alternative splicing by deletion of exon 4 in L5 and deletion of exon 2 in V. The mRNA transcripts were differentially expressed in fetal and adult human kidney with Q1 the major species. Exon 4-L5 lacked 183 residues from the carboxyl terminus with a frameshift producing a unique 11-amino acid terminal peptide. In exon 2-V a frameshift resulted in a unique V carboxyl terminus of 53 novel peptides with a new glycosylation site. The size of recombinant proteins indicated the frameshifts and new stop codons were as predicted. The multiple forms of the alpha 3(IV) NC1 region may contribute to autoimmune glomerular disease and hereditary nephritis, in which this portion of the collagen IV molecule is thought to play an important role.

Identification and mutation of primary and secondary proteolytic cleavage sites in murine stem cell factor cDNA yields biologically active, cell-associated protein

Phenotypic abnormalities of melanocytes, germ cells, and hematopoietic cells of Steel mice demonstrate the critical role of stem cell factor (SCF) in development. Production of SCF in the hematopoietic microenvironment as either a membrane-associated or soluble factor leads to pleiotropic effects on hematopoietic stem and progenitor cells and significant effects on the production of erythroid cells. Although the production of these two forms of SCF is highly regulated, the physiologic role(s) of membrane-associated and soluble SCF remain unclear. We have demonstrated that the generation of soluble murine SCF by murine stromal cells derived from the fetal hematopoietic microenvironment is dependent on two distinct proteolytic cleavage sites. The primary site in exon 6 is preferentially utilized in these cells. The secondary site located in exon 7 is utilized only in the absence of the primary site. Proteolytic processing at this secondary site appears to be species-specific, since the human protein sequence diverges at this site, and protein expressed from the human cDNA encoding this site in murine stromal cells remains largely membrane-associated. Site-directed mutagenesis of the murine SCF cDNA encoding both proteolytic cleavage sites leads to the generation of membrane-associated and biologically active SCF on murine stromal cells. These results suggest that the regulation of processing of the secondary proteolytic cleavage site could play a critical role in the function of membrane-associated SCF protein.

Interleukin-1 receptor antagonist ameliorates experimental anti-glomerular basement membrane antibody-associated glomerulonephritis

The contribution of IL-1 to leukocyte infiltration in anti-glomerular basement membrane (GBM) antibody (Ab) glomerulonephritis (GN) was examined by the administration of a specific IL-1 receptor antagonist (IL-1ra). Lewis rats received anti-GBM Ab or normal rabbit serum and were treated with either 0.9% saline or 6 mg IL-1ra over a 24-h time period. Plasma IL-1ra concentration was 2,659 +/- 51 ng/ml 4 h after anti-GBM Ab and IL-1ra administration. PMN and monocyte/macrophage infiltration declined 39% (9.8 +/- 1.9 to 6.0 +/- 1.5 PMN/glomerulus, P < 0.001) and 29% (4.9 +/- 0.8 to 3.5 +/- 0.8 ED-1 cells/glomerulus, P = 0.002) with IL-1ra treatment at 4 h, respectively. Similarly, the number of glomerular cells staining for lymphocyte function-associated molecule-1 beta (CD18) declined 39% from 16.7 +/- 1.9 to 10.7 +/- 1.6 cells/glomerulus at 4 h (P = 0.0001). This was associated with a decrease in glomerular intracellular adhesion molecule-1 expression. The mean glomerular intracellular adhesion molecule-1 score in anti-GBM Ab GN rats treated with IL-1ra was less than that of rats administered anti-GBM Ab and 0.9% saline at 4 (2.0 +/- 0.2 vs 2.5 +/- 0.2, P < 0.05) and 24 (2.5 +/- 0.1 vs 3.1 +/- 0.2, P = 0.0001) h. These immunopathologic changes correlated with a 50% reduction in proteinuria from 147 +/- 34 to 75 +/- 25 mg/d (P < 0.002). Treatment with IL-1ra did not affect the steady state mRNA expression of either IL-1 beta or TNF alpha. An increase in the IL-1ra dose to 30 mg given within the initial 4 h provided no additional benefit. The decline in PMN and monocyte/macrophage infiltration of the glomerulus at 4 h was similar to that found in the initial study. Furthermore, the protective benefit of IL-1ra was abrogated by doubling the dose of the anti-GBM Ab GN, despite administering high dose IL-1ra (30 mg). In these studies, detectable IL-1ra was found in the serum of untreated anti-GBM Ab GN controls. These data suggest a positive yet limited role for IL-1ra in the therapeutic intervention of anti-GBM Ab GN.

An optimized multiplex polymerase chain reaction (PCR) for detection of BCR-ABL fusion mRNAs in haematological disorders

A rapid and simple polymerase chain reaction (PCR) method is described that is capable of identifying any of the BCR-ABL transcripts that have yet been described in chronic myeloid or acute lymphoblastic leukaemia. Randomly primed cDNA is synthesized from leucocyte RNA and amplified in a single reaction containing four oligonucleotide primers (multiplex PCR). Different size products are generated from ela2 (p190) and b3a2 or b2a2 (p210) BCR-ABL transcripts which are readily and unambiguously distinguishable after agarose gel electrophoresis without the need for either nested PCR or hybridization. Chronic myeloid leukaemia cells are readily detectable even when diluted 1 in 1000 with normal blood. Samples which do not have BCR-ABL rearrangements produce a single band derived from the normal BCR gene, and the presence of this band controls for adequate RNA and cDNA preparation. Using this assay we have detected BCR-ABL transcripts in a variety of haematological disorders.

Association of the hepatic IP3 receptor with the plasma membrane: relevance to mode of action

Studies were carried out to characterize the interaction between inositol 1,4,5-trisphosphate (IP3) receptors and the plasma membrane fraction. Extraction of the membranes with the nonionic detergents Nonidet P-40 and Triton X-100, followed by centrifugation at 100,000 g, resulted in the doubling of the IP3 receptor in the pellets, whereas no detectable binding was found in the supernatants. These data indicate that the detergents did not solubilize the receptor, that it remained associated with membrane particles, and that it is likely to be associated with the cytoskeleton. The cytoskeleton proteins actin, ankyrin, and spectrin were identified in the plasma membrane fraction. However, comparison of the amount of these proteins in different fractions of the detergent, or otherwise treated plasma membrane fractions, showed no direct correlation between the presence of any of these proteins in the plasma membrane fraction and their ability to bind [3H]IP3. This is in contrast to the brain and T-lymphoma cells in which the IP3 receptor is attached to ankyrin (L. Y. W. Bourguigon, H. Jin, N. Iida, N. R. Brandt, and S. H. Zhang. J. Biol. Chem. 268: 6477-6486, 1993; and S. K. Joseph and S. Samanta. J. Biol. Chem 268: 6477-6486, 1993). Thus the hepatic IP3 receptor, which is different from the brain receptor, might attach to the cytoskeleton by anchoring to a different protein. Because cytochalasin D treatment of livers diminishes the ability of IP3 to raise cytosolic free Ca2+ levels, the attachment of the IP3 receptor to the cytoskeleton seems to involve an association with microfilaments.

Cloning two isoforms of rat cyclooxygenase: differential regulation of their expression

Two isoforms of cyclooxygenase (COX) have been identified in eukaryotic cells: COX-1 encoded by a 2.8-kb mRNA, and a mitogen-inducible COX-2 encoded by a 4-kb mRNA. We have cloned the COX-1 and COX-2 cDNAs from the cDNA library constructed from lipopolysaccharide (LPS)-stimulated rat peritoneal macrophages. The deduced amino acid sequence showed that COX-1 contained 602 amino acids, whereas COX-2 contained 604 amino acids. There is 95% conservation of the nucleotide sequence in the open reading frame of COX-1 between the rat and the mouse, while the homology of the 3' untranslated region is 68% except for a 150 bp segment adjacent to the stop codon which is nonhomologous with the mouse. Transfection of both COX cDNAs into Cos-7 cells resulted in increased COX activity. In rat vascular smooth muscle cells, interleukin-1 beta selectively increased the expression of COX-2, but not that of COX-1, as assessed by enzyme activity, immunoprecipitation of COX proteins, and mRNA analysis. Only the brain among tissues tested exhibits basal expression of COX-2 as the major form of the enzyme. However, COX-2 mRNA was expressed in vivo in the lung and kidney, but not in the heart, after systemic administration of LPS, suggesting that COX-2 but not COX-1 plays a major role in producing COX-derived products of arachidonic acid during endotoxic shock. Thus, the two COX isoforms were differentially expressed, and COX-2 was selectively induced in response to inflammatory stimuli in rats.

Competitive polymerase chain reaction to estimate the number of BCR-ABL transcripts in chronic myeloid leukemia patients after bone marrow transplantation

We have developed a competitive polymerase chain reaction (PCR) titration assay that estimates the number of BCR-ABL transcripts in chronic myeloid leukemia patients to monitor minimal residual disease after bone marrow transplantation (BMT). The assay gave reproducible results and allowed differences in BCR-ABL message levels of half an order of magnitude to be distinguished. Of 91 patients studied by nonquantitative PCR, 28 who had a positive PCR result on at least one occasion posttransplant were analyzed by competitive PCR. Seventeen patients had no evidence in their marrow of cytogenetic relapse during the period of observation; BCR-ABL transcript numbers in these cases ranged from approximately 10 to 800/micrograms RNA. Ten of the 11 patients who relapsed cytogenetically were studied when Philadelphia-positive metaphases were first detected in their marrow; transcript numbers ranged from 1,600 to 7 x 10(5)/micrograms RNA. Patients in hematologic relapse had between 9 x 10(4) and 10(6) BCR-ABL transcripts/micrograms RNA. Patients who progressed from cytogenetic remission to cytogenetic relapse and then to hematologic relapse had increasing numbers of BCR-ABL transcripts in their blood. Three patients had clear evidence of rising numbers of BCR-ABL transcripts before routine detection of cytogenetic relapse. Conversely patients without cytogenetic relapse generally had low or falling numbers of transcripts. We conclude that serial monitoring of residual disease post-BMT by estimating the number of BCR-ABL transcripts provides more information than conventional cytogenetics or nonquantitative PCR and may identify patients in need of therapeutic intervention before the onset of overt relapse.

Cloning a novel form of rat PDGF A-chain with a unique 5'-UT: regulation during development and in glomerulonephritis

An unique form of rat platelet-derived growth factor A-chain (PDGF A-chain), with a novel 5' UT region, was cloned from a rat macrophage cDNA library and expressed. In the 5' UT, the homology of the 79 bp sequence adjacent to the ATG codon between rat and human was 92%; however, the homology of the remainder in the 5' UT was less than 30%. RNase mapping indicated this form was differentially expressed during development and immune glomerular injury, and that it probably arose from alternative splicing. We propose that the variant mRNAs reflect different levels of the control of PDGF A-chain expression.

[Quality of rhizoma Anemarrhenae grown for different periods of time and gathered in different seasons]

The experimental results have shown that except the stem and leaves all kinds of Rhizoma Anemarrhenae and all parts of the herb contain sarsasapogenin, but the contents are different. Furthermore, the root and peel of Rhizoma Anemarrhenae may be used as drug instead of Rhizoma Anemarrhenae.

Mammalian eukaryotic initiation factor 2 alpha kinases functionally substitute for GCN2 protein kinase in the GCN4 translational control mechanism of yeast

Phosphorylation of the alpha subunit of eukaryotic initiation factor 2 (eIF-2 alpha) in Saccharomyces cerevisiae by the GCN2 protein kinase stimulates the translation of GCN4 mRNA. The protein kinases heme-regulated inhibitor of translation (HRI) and double-stranded RNA-dependent eIF-2 alpha protein kinase (dsRNA-PK) inhibit initiation of translation in mammalian cells by phosphorylating Ser-51 of eIF-2 alpha. We show that HRI and dsRNA-PK phosphorylate yeast eIF-2 alpha in vitro and in vivo and functionally substitute for GCN2 protein to stimulate GCN4 translation in yeast. In addition, high-level expression of either mammalian kinase in yeast decreases the growth rate, a finding analogous to the inhibition of total protein synthesis by these kinases in mammalian cells. Phosphorylation of eIF-2 alpha inhibits initiation in mammalian cells by sequestering eIF-2B, the factor required for exchange of GTP for GDP on eIF-2. Mutations in the GCN3 gene, encoding a subunit of the yeast eIF-2B complex, eliminate the effects of HRI and dsRNA-PK on global and GCN4-specific translation in yeast. These results provide further in vivo evidence that phosphorylation of eIF-2 alpha inhibits translation by impairing eIF-2B function and identify GCN3 as a regulatory subunit of eIF-2B. These results also suggest that GCN4 translational control will be a good model system to study how mammalian eIF-2 alpha kinases are modulated by environmental signals and viral regulatory factors.

Dysfunction of glomerular fibrinolysis in experimental antiglomerular basement membrane antibody glomerulonephritis

Glomerular plasminogen activator inhibitor-1 (PAI-1) steady-state mRNA and bioactivity were increased after the induction of an augmented form of antiglomerular basement membrane (GBM) antibody glomerulonephritis. PAI-1 mRNA expression was noted at 6 h, peaking at 1 day, and although falling thereafter, remained higher than that of the control group through Day 17. PAI-1 mRNA expression correlated with glomerular PAI-1 bioactivity as determined by a functional tissue type plasminogen activator (t-PA) binding assay. Glomerular PAI-1 bioactivity, not detected in controls, increased to 1.4 +/- 0.3 ng/mg of glomerular lysate at 6 h and then decreased to 0.7 +/- 0.1 ng/mg of glomerular lysate by Day 6. The mRNA of the plasminogen activators (urokinase plasminogen activator), t-PA) either remained unchanged or declined through Day 1, with a slight increase in t-PA mRNA at Day 6. Interleukin-1 beta mRNA expression was maximal at 6 h, declining by Day 3. Transforming growth factor beta 1 (TGF-beta 1) mRNA began to increase at Day 1, was maximal at Day 6, and fell only slightly by Day 17. Epidermal growth factor mRNA decreased. The increase in PAI-1 mRNA and bioactivity, possibly induced early by the interleukin-1 beta response and perhaps later by the TGF-beta 1 response, was associated with striking glomerular capillary lumen fibrin accumulations on Day 1, which decreased and appeared to recanalize as the PAI-1 mRNA and bioactivity fell. The glomerular lesion continued to have some fibrin deposits even on Day 17 and, in addition, had changes of thickened GBM, suggestive of the early stages of diffuse glomerulosclerosis. The latter had a temporal relationship with the persisting increase in TGF-beta 1 and PAI-1 mRNA levels. These observations suggest the possibility that inhibition of enzymes capable of remodeling excessive extracellular matrix production may have contributed to the thickened GBM.

Minimal residual disease after allogeneic bone marrow transplantation for chronic myeloid leukaemia in first chronic phase: correlations with acute graft-versus-host disease and relapse

We have studied 61 patients who underwent allogeneic bone marrow transplantation (BMT) for chronic myeloid leukaemia (CML) in first chronic phase. Minimal residual disease was detected by the amplification of the leukaemia-specific BCR-ABL fusion mRNA with the polymerase chain reaction (PCR) using a highly sensitive nested primer strategy. As a general pattern, patients often had detectable BCR-ABL (PCR positive) for up to 6 or 9 months post BMT after which time BCR-ABL became undetectable (PCR negative). The conversion from PCR positive to PCR negative was not associated with the time at which cyclosporin A treatment was stopped. Six patients (10%) have relapsed during the period of this study, two within 1 year and four more than 1 year after transplant. The relationship between PCR positivity more than 1 year post transplant and relapse was significant (P = 0.036) but 15 patients who were PCR positive beyond 1 year remain in complete clinical and cytogenetic remission. Thus late positivity identifies a group of patients at increased risk of relapse but is of little predictive value for individual patients. Of the four late relapses, two had been persistently PCR positive and two were initially PCR positive, converted to negative and subsequently to positive again. Although all relapses were preceded by PCR positivity, relapse may occur only 12 months after a PCR negative result. The proportion of patients PCR negative at 3/4 months after BMT was found to increase significantly with the severity of acute GVHD (P = 0.002) but no relationship was found between acute GVHD and subsequent PCR results. There was no clear association between severity of chronic GVHD and PCR result.

LPS-induced MCP-1, IL-1 beta, and TNF-alpha mRNA expression in isolated erythrocyte-perfused rat kidney

The capacity of the lipopolysaccharide (LPS)-stimulated isolated erythrocyte-perfused rat kidney (IEPK) to produce monocyte chemoattractant protein-1 (MCP-1), interleukin-1 beta (IL-1 beta), and tumor necrosis factor-alpha (TNF-alpha) mRNA was investigated. The IEPK was chosen to exclude the influence of circulating neutrophils and monocytes that can produce both these mediators when exposed to LPS. The control minimal LPS group (LPS < 10 pg/ml) showed a small increase in mRNA expression for MCP-1, IL-1 beta, and TNF-alpha in the cortex and medulla after 80 min of perfusion when compared with the unperfused left kidney in which no IL-1 beta or TNF-alpha mRNA and only minimal amounts of MCP-1 mRNA were detected. LPS stimulation (1 microgram/ml for 40 or 80 min) increased MCP-1, IL-1 beta, and TNF-alpha mRNA expression, which was found predominately in peritubular capillary endothelial cells by in situ hybridization. The changes were not due to a marked perturbation of LPS on renal hemodynamics. The renal vascular resistance (RVR) remained constant (40 min LPS exposure) or increased only slightly during the last 5-10 min (80 min LPS exposure) compared with a progressive increase in RVR of the minimal LPS group. The hemodynamic effects of LPS on the IEPK appear to counteract the gradual increase in RVR seen in the minimal LPS group.

Molecular cloning of rat cytokine synthesis inhibitory factor (IL-10) cDNA and expression in spleen and macrophages

Rat cytokine synthesis inhibitory factor (IL-10) was cloned. Like mouse and human IL-10 (mIL-10, hIL-10), rat IL-10 exhibits strong DNA and amino acid sequence homology to the open reading frame in the Epstein-Barr virus, BCRFI. The supernatant of COS-7 transfectants with rat IL-10 was found to inhibit the production of IFN-gamma by murine Th1 cells. A probe from the rat IL-10 was used in an RNase protection assay to demonstrate that IL-10 was expressed in LPS-stimulated rat spleen and FACS-purified OX-42-reactive peritoneal macrophages. The production of IL-10 by macrophages, as shown in the current study, suggests that IL-10 may have an autocrine function in inflammation.

[Quality standards for qingwei huanglian pills]

In the paper systematic studies on quality standards for Qingwei Huanglian Pills are reported, along with the TLC identification of Gardenia jasminoides, Scutellaria baicalensis and Anemarrhena asphodeloides and the quantitative determination of berberine in Coptis chinensis and Phellodendron chinese by TLC densitometric method. To simplify the operation, the same solvent was used for both the identification and determination. The quantitative method is simple, sensitive, reproducible and accurate. The recovery of berberine is 99.48%. The coefficient of variation is 1.42%.

Surface atomic and domain structures of biomedical carbons observed by scanning tunneling microscopy (STM)

STM has been used to study the surface domain and atomic structures of three biomedical carbons: glassy carbon (GC), low-temperature isotropic carbon (LTI), and ultra-low-temperature isotropic carbon (ULTI). The images show atomic lattices on both GC and LTI, but not on ULTI. The lattices contain many defects; lattices in GC are more ordered than those in LTI. The images also show patchlike carbon crystallites with sizes of 3-15 nm for GC, 2-8 nm for LTI, and 1-3 nm for ULTI. The crystallites from surface domains that may differ in surface properties due to different orientations of the crystallites. Mechanical polishing makes the LTI surface more amorphous and more homogeneous. Based on the STM observations, we evaluate several hypotheses on the blood compatibility of biomedical carbons.

Changing patterns of gene expression define four stages of cerebellar granule neuron differentiation

Among CNS neuronal populations, the cerebellar granule cell provides a simple model for analysing the molecular regulation of CNS neurogenesis. In this study, polyclonal antisera raised against immature granule cell precursors, purified from early postnatal mouse cerebellum, were used to isolate 39 unique cDNA clones from a lambda gt11 cDNA expression library made from the same cell population. Northern blot analysis revealed developmental stage and tissue-specific expression of 28 of the clones. In situ localization of mRNAs encoded by these novel cDNAs, as well as those encoding the axonal glycoprotein TAG-1 and the alpha 6 subunit of the GABAA receptor, reveal four distinct stages in cerebellar granule cell differentiation. The developmentally transient and spatially restricted expression of clones GC9 and GC44 identify a previously unrecognized step in cerebellar histogenesis.