Elevated Egr-1 in human atherosclerotic cells transcriptionally represses the transforming growth factor-beta type II receptor

Atherosclerotic lesions may progress due to a "failure to die" by vascular repair cells. Egr-1, a zinc finger transcription factor, is elevated more than 5-fold in human carotid lesions relative to the adjacent tunica media. Lesion cells in vitro also express 2-3-fold higher Egr-1 mRNA and protein levels but express much lower levels of the transforming growth factor-beta (TGF-beta) Type II receptor (TbetaR-2) and are functionally resistant to the antiproliferative effects of TGF-beta. Lesion cells fail to express a TbetaR-2 promoter/chloramphenicol acetyltransferase (CAT) construct but overexpress an Egr-1-inducible platelet-derived growth factor-A promoter/CAT construct. Transfection of Egr-1 cDNA represses TbetaR-2/CAT constructs but induces PDGF-A/CAT. Egr-1 transfection reduces the levels of TbetaR-2 and confers resistance to the antiproliferative effect of TGF-beta1. Egr-1 can interact directly with both the -143 Sp1 site and the positive regulatory element 2 (PRE2) (ERT/ets) region of the TbetaR-2 promoter. Thus, although activating a family of stress-responsive genes, Egr-1 also transcriptionally represses one of the major inhibitory pathways that restrains vascular repair.

Rifampicin polylactic acid microspheres for lung targeting

Rifampicin polylactic acid microspheres for lung targeting were prepared by a modified emulsion-solvent diffusion method. The microspheres were free flowing, spherical with regular surface. Drug content, particle size distribution and in vitro release properties of the prepared microspheres were evaluated. In vivo experiments on rabbits showed remarkable accumulation of microspheres in the lung.

A novel immunoadsorbent for rheumatoid arthritis therapy--preparation and efficacy evaluation

AIM

To develop a novel immunoadsorbent for rheumatoid arthritis (RA) therapy.

METHODS

A RA immunoadsorbent was developed by binding heat-aggregated human IgG(HAHIgG) to porous agar gel beads. Its adsorption capacity for rheumatoid factors (RFs), storage stability and blood compatibility were evaluated.

RESULTS

The coupling yield of HAHIgG on the carrier was 6.0 mg/g wet gel. Saturation adsorption capacity of the adsorbent for IgMRF, IgGRF and IgARF were 3400, 2240 and 2400 IU/g, respectively. The adsorbent can be stored at 4 degrees C for three months without significant variance in its activity. Its fine permeability and hemocompatibility were demonstrated by extracorporeal hemoperfusion on rabbits.

CONCLUSION

HAHIgG/agar gel is a safe and effective immunoadsorbent for RA therapy, its potential clinical use is promising in the future.

Effects of acute exposure to mild or moderate hypoxia on human psychomotor performance and visual-reaction time

Objective. The aim of this study was to determine whether psychomotor performance and visual reaction time were affected by acute exposure to mild or moderate hypoxia. Method. Eighteen healthy male volunteers performed finger tapping, simple reaction time (SRT) and 4-choice reaction time (CRT) tests at simulated altitude of 300 m (control), 2800 m, 3600 m and 4400 m for 1 h in a hypobaric chamber. Result. SaO2 decreased from 98% (control) to 90%, 82% and 74% respectively at the various altitudes. All the performance parameters showed no significant change after exposure to 2800 m for 1 h relative to ground level (P>0.05). However the mean reaction time of 4-CRT under 3600 m prolonged and performance decreased as compared with baseline value (P<0.05), and the performance decreased further under 4400 m (P<0.01). No significant difference was found in finger tapping and SRT even under exposure to 4400 m for 1 h. Furthermore, no decrease in correct rate were observed at any altitude (P>0.05). Conclusion. The results from this study demonstrated that there were no measurable impairment of visual reaction time and psychomotor performance under exposure to an altitude of 2800 m for 1 h. However, adverse effects on psychomotor performance were observed under 3600 m and over.

Blockade of RAGE-amphoterin signalling suppresses tumour growth and metastases

The receptor for advanced glycation end products (RAGE), a multi-ligand member of the immunoglobulin superfamily of cell surface molecules, interacts with distinct molecules implicated in homeostasis, development and inflammation, and certain diseases such as diabetes and Alzheimer's disease. Engagement of RAGE by a ligand triggers activation of key cell signalling pathways, such as p21ras, MAP kinases, NF-kappaB and cdc42/rac, thereby reprogramming cellular properties. RAGE is a central cell surface receptor for amphoterin, a polypeptide linked to outgrowth of cultured cortical neurons derived from developing brain. Indeed, the co-localization of RAGE and amphoterin at the leading edge of advancing neurites indicated their potential contribution to cellular migration, and in pathologies such as tumour invasion. Here we demonstrate that blockade of RAGE-amphoterin decreased growth and metastases of both implanted tumours and tumours developing spontaneously in susceptible mice. Inhibition of the RAGE-amphoterin interaction suppressed activation of p44/p42, p38 and SAP/JNK MAP kinases; molecular effector mechanisms importantly linked to tumour proliferation, invasion and expression of matrix metalloproteinases.

[The expressions of p16, CDK4 and PCNA proteins in trophoblastic tumors]

OBJECTIVE

To evaluate the relationship between the regulatory factors in G1 phase of cell cycle and the cacrinogenesis of the trophoblastic cells.

METHODS

The expressions of p16, cyclin-dependent kinase 4 (CDK4), proliferation cell nuclear antigen (PCNA) proteins in 18 cases of trophoblastic tumors, 30 cases of hydatidiform mole and 30 cases of normal villi were studied by immunohistochemical methods.

RESULTS

The expressions of p16 protein between malignant trophoblastic tumors and normal villi were significantly different (P < 0.05). PCNA positive rate in p16 positive samples were markedly lower than that in negative samples (P < 0.05). The expressions of CDK4 among normal villi, hydatiform mole and trophoblastic tumors were not significantly different. Patients with positive p16 expression had a higher 3 year survival rate.

CONCLUSION

p16 protein may inhibit trophoblastic cells proliferation, and p16 gene mutation may be an important factor in carcinogenesis of trophoblastic cells and proliferation out of control. P16 protein expression examination is helpful in prediction of patients prognosis.

alpha(v)beta(3) integrin induces tyrosine phosphorylation-dependent Ca(2+) influx in pulmonary endothelial cells

The endothelial alpha(v)beta(3) integrin occurs luminally, where its ligation by soluble agents may induce inflammatory signaling. We tested this hypothesis in bovine pulmonary artery endothelial cell monolayers with the use of vitronectin and cross-linking antibodies to ligate and aggregate the integrin. We quantified the endothelial cytosolic Ca(2+) concentration ([Ca(2+)](i)) according to the Fura 2 ratio imaging method in single cells of confluent monolayers. At baseline, endothelial [Ca(2+)](i) levels remained steady at 86 nmol/L for >20 minutes. Cross-linking of the alpha(v)beta(3) integrin through the sequential exposure of monolayers to anti-alpha(v)beta(3) monoclonal antibody LM609 and secondary IgG resulted in a [Ca(2+)](i) increase of 100% above baseline. This increase commenced in <0.5 minute, peaked in <2 minutes, and decayed to baseline in approximately 5 minutes. Similar responses occurred after the addition of vitronectin (400 microg/mL). In contrast, external Ca(2+) depletion blunted the cross-linking-induced [Ca(2+)](i) increase by 60%, a response that was completely inhibited when the monolayers were also pretreated with thapsigargin. Thus, the [Ca(2+)](i) increase was attributable in part to the release of Ca(2+) from endosomal stores but mostly to Ca(2+) influx across the plasma membrane. Induced aggregation of the alpha(v)beta(3) integrin enhanced tyrosine phosphorylation of phospholipase C-gamma1 and increased the accumulation of inositol-1, 4,5-trisphosphate. Genistein, a broad-spectrum tyrosine kinase inhibitor, abrogated both of these effects, as well as the alpha(v)beta(3)-induced [Ca(2+)](i) increases. We conclude that aggregation of the endothelial alpha(v)beta(3) integrin induces a rapid tyrosine phosphorylation-dependent increase in [Ca(2+)](i). This response may subserve the inflammatory role of alpha(v)beta(3) integrin in blood vessels.

High-level expression of Egr-1 and Egr-1-inducible genes in mouse and human atherosclerosis

To understand the mRNA transcript profile in the human atherosclerotic lesion, RNA was prepared from the fibrous cap versus adjacent media of 13 patients undergoing carotid endarterectomy. cDNA expression arrays bearing 588 known genes indicated that lesions express unexpectedly high levels of the early growth response gene, Egr-1 (NGFI-A), a zinc-finger transcription factor that modulates a cluster of stress-responsive genes including PDGF and TGF-beta. Expression of Egr-1 was an average of 5-fold higher in the lesion than in the adjacent media, a result confirmed by RT-PCR, and many Egr-1-inducible genes were also strongly elevated in the lesion. Time-course analyses revealed that Egr-1 was not induced ex vivo. Immunocytochemistry indicated that Egr-1 was expressed prominently in the smooth muscle-actin positive cells, particularly in areas of macrophage infiltration, and in other cell types, including endothelial cells. Induction of atherosclerosis in LDL receptor-null mice by feeding them a high-fat diet resulted in a progressive increase in Egr-1 expression in the aorta. Thus, induction of Egr-1 by atherogenic factors may be a key step in coordinating the cellular events that result in vascular lesions.

Effects of acute mild and moderate hypoxia on human mood state

OBJECTIVE

To explore the effects of acute mild and moderate hypoxia on human mood state.

METHOD

The mood states of 18 healthy male volunteers were evaluated by self-assessment questionnaires, profile of mood state (POMS) and state anxiety inventory (S-AI) after random exposure to simulated altitude of 300 m (control), 2800 m, 3600 m and 4400 m for 1 h in a hypobaric chamber.

RESULT

The data at 300 m level were taken as the baseline control. The negative mood state factor points (tension, fatigue etc.) increased gradually as the altitude level increased while V (vigor-activity) points had a tendency to decrease (P<0.05 or P<0.01). No significant difference was found in the points of (D, A) even under exposure to 4400 m (P>0.05). At the early period of 2800 m exposure the tension points of POMS and S-AI scores were higher than those of control level (P<0.05) then dropped to baseline level when exposure to this altitude for 1 h.

CONCLUSION

Exposure to acute mild hypobaric hypoxia at 2800 m for 1 h has adverse effect on mood state of healthy person and the negative effect was further aggravated with the increment of altitude level.

Vascular expression of the alpha(v)beta(3)-integrin in lung and other organs

The expression of the alpha(v)beta(3)-integrin in nonproliferating vascular beds remains unclear. To determine possible organ-specific differences, we compared alpha(v)beta(3)-integrin expression in the lung and other organs. Paraffin-embedded tissue sections of lung, liver, brain, muscle and skin obtained from rats were processed for immunohistochemistry with a monoclonal (LM609) and a polyclonal antibody (AB1903) against the alpha(v)beta(3)-integrin. Immunogold electron microscopy was used to localize alpha(v)beta(3)-integrin in rat lung microvasculature. With the use of custom-designed primers, lung sections were subjected to in situ PCR in a thermal cycler to amplify alpha(v) or beta(3) mRNA. To confirm specific amplification, PCR products were further hybridized in situ with an alpha(v) or beta(3) cDNA probe. In the lung, the alpha(v)beta(3)-integrin protein as well as alpha(v) and beta(3) mRNAs was extensively evident in the endothelium of extra-alveolar and alveolar microvessels, in vascular smooth muscle, and in large bronchial epithelium but not in the epithelium of alveolar ducts or alveoli. Ultrastructural immunogold labeling showed the presence of the integrin on the luminal and abluminal faces of the lung microvascular endothelium but not on the apical surface of the alveolar epithelium. Staining for the integrin was generally negative in blood vessels of several systemic organs, although weak staining was evident in branches of the hepatic portal vein. The constitutive presence of the alpha(v) and beta(3) mRNAs and the alpha(v)beta(3)-integrin in the lung microvascular bed suggests that gene transcription for the integrin is ongoing in lung vessels. Because it binds vitronectin, the lung vascular alpha(v)beta(3)-integrin may play a role in ligation of bloodborne, vitronectin-containing macromolecular complexes formed in inflammation.

N(epsilon)-(carboxymethyl)lysine adducts of proteins are ligands for receptor for advanced glycation end products that activate cell signaling pathways and modulate gene expression

Recent studies suggested that interruption of the interaction of advanced glycation end products (AGEs), with the signal-transducing receptor receptor for AGE (RAGE), by administration of the soluble, extracellular ligand-binding domain of RAGE, reversed vascular hyperpermeability and suppressed accelerated atherosclerosis in diabetic rodents. Since the precise molecular target of soluble RAGE in those settings was not elucidated, we tested the hypothesis that predominant specific AGEs within the tissues in disorders such as diabetes and renal failure, N(epsilon)-(carboxymethyl)lysine (CML) adducts, are ligands of RAGE. We demonstrate here that physiologically relevant CML modifications of proteins engage cellular RAGE, thereby activating key cell signaling pathways such as NF-kappaB and modulating gene expression. Thus, CML-RAGE interaction triggers processes intimately linked to accelerated vascular and inflammatory complications that typify disorders in which inflammation is an established component.

The expression of TGF-beta receptors in human atherosclerosis: evidence for acquired resistance to apoptosis due to receptor imbalance

The degree of cellularity in vascular lesions is determined by the balance between the migration and proliferation of cells relative to their rate of egress and apoptosis. Transforming growth factor-beta(1) can act as a potent antiproliferative and apoptotic factor for proliferating vascular cells. Our laboratory has previously identified cells cultured from human vascular lesions that are resistant to the antiproliferative effect of TGF-beta(1) due to an acquired mutation in the Type II receptor for TGF-beta(1). In the present studies, the expression of the Type I and II receptors in coronary and carotid atherosclerotic lesions was analysed by immunostaining, RT-PCR, and in situ RT-PCR. Levels of the Type I and Type II receptors varied widely within lesions, with the highest levels in the fibrous cap and at discrete foci within the lesion. Regions of smooth muscle-like cells (SMC) were commonly found that were Type I positive but Type II receptor negative. In 43 cell lines cultured from 126 human lesions, 84% of the lesion-derived cell (LDC) cultures exhibited functional resistance to the antiproliferative effect of TGF-beta(1). This resistance was conferred against TGF-beta(1), TGF-beta(2), and TGF- beta(3), but not interferon-gamma or mimosine. While normal SMC exhibited a four-fold increase in the rate of apoptosis after TGF- beta(1) treatment, most LDC were resistant to apoptosis in response to TGF-beta(1). Resistant cells exhibited selective loss of Type II receptor expression, and retroviral transfection of Type II receptor cDNA partially corrected the functional deficit. Thus, resistance to apoptosis may lead to the slow proliferation of resistant cell subsets, thereby contributing to the progression of atherosclerotic and restenotic lesions.

[The study of ethanol-water used as reversed-phase high performance liquid chromatographic mobile phase]

The viscosity of ethanol-water at various temperatures was determined. The physicochemical properties and characters of the solvents used as the mobile phase of reversed-phase high performance liquid chromatography(RP-HPLC) were compared between methanol and ethanol. The components of several Chinese medicines have been determined by RP-HPLC with ethanol-water used as mobile phase, and the results were compared with those obtained with methanol-water or acetonitrile-water. It showed that ethanol can be used as RP-HPLC mobile phase by increasing the column temperature moderately.

[Observation on effect of chongcao shenkang capsules in preventing and treating acute renal failure in cases of hemorrhagic fever with renal syndrome]

OBJECTIVE

To observe the effect of Chongcao shenkang capsules in preventing and treating acute renal failure in cases of hemorrhagic fever with renal syndrome (HFRS).

METHODS

150 cases of HFRS were randomly divided into two groups: the treatment group and the control group. The former contained 76 cases and the latter the 74 cases. All cases in both groups were given a combined therapy mainly composed of balanced salt solution and ribavirin, cases in treatment group additionally accepted Chongcao shenkang capsules 2.7 grams tid, till the end of polyuric phase.

RESULTS

The results showed that in the treatment group the occurrence rate of cases with oliguric phase was 13.0% (4/46) and the oliguric and polyuric periods were 2.7 +/- 1.6 days and 6.8 +/- 2.9 days respectively while those in the control group were 31.1% (4/45), 4.3 +/- 2.1 dnys and 8.2 +/- 3.4 days respectively (P < 0.01 or P < 0.05). The urinary protein of the treatment group disappeared within 5.1 +/- 2.3 days and their serum creatinine restored within 10.9 +/- 6.2 days, but the urinary protein disappearing and the serum creatinine restoring periods of the control group were 6.8 +/- 2.7 days and 13.7 +/- 7.4 days respectively (P < 0.01 or P < 0.05). The serum and urine beta 2-microglobulin levels of the treatment group were remarkably lower than those of the control group on the fifth and tenth days after treatment (P < 0.01 or P < 0.05). Compared with those of the control group of 33.8% (25/74) and 87.8% (65/74), the occurrence rate of severe complications and curative rate of the treatment group were 18.4% (14/76) and 94.7% (72/76) respectively (the former P < 0.05, but the latter P > 0.05).

CONCLUSION

It was concluded that Chongcao shenkang capsules is capable of reducing the occurrence rate of acute renal failure in HFRS patients, shortening the duration of acute renal failure, decreasing their needs for dialysis, lessening their complications and increasing their curative rate. Its administration is safe and convenient and therefore it is worthy to be popularized.

RAGE mediates a novel proinflammatory axis: a central cell surface receptor for S100/calgranulin polypeptides

S100/calgranulin polypeptides are present at sites of inflammation, likely released by inflammatory cells targeted to such loci by a range of environmental cues. We report here that receptor for AGE (RAGE) is a central cell surface receptor for EN-RAGE (extracellular newly identified RAGE-binding protein) and related members of the S100/calgranulin superfamily. Interaction of EN-RAGEs with cellular RAGE on endothelium, mononuclear phagocytes, and lymphocytes triggers cellular activation, with generation of key proinflammatory mediators. Blockade of EN-RAGE/RAGE quenches delayed-type hypersensitivity and inflammatory colitis in murine models by arresting activation of central signaling pathways and expression of inflammatory gene mediators. These data highlight a novel paradigm in inflammation and identify roles for EN-RAGEs and RAGE in chronic cellular activation and tissue injury.

Administration of interleukin-12 exerts a therapeutic instead of a long-term preventive effect on mite Der p I allergen-induced animal model of airway inflammation

Interleukin-12 (IL-12) is a key cytokine, which promotes T helper type 1 (Th1) cell-mediated immunity and inhibits Th2-type responses. It has been previously shown that IL-12 administration during active immunization following a single allergen exposure can prevent antigen-induced increases in immunoglobulin E (IgE) formation, Th2 cytokine production and bronchoalveolar lavage (BAL) eosinophils in a murine model of allergic airway inflammation. Thus, these studies have now been extended and two IL-12 treatment protocols on this murine model were evaluated. Administration of IL-12 during the active immunization strikingly increased Der p I-specific serum IgG2a and transiently decreased the levels of IgG1 and IgE antibodies following multiple allergen challenges. Such early treatment of IL-12 down-regulated IL-5 production and modestly up-regulated interferon-gamma production but did not effect BAL eosinophilia. These results suggest that repeated exposure to antigen and IL-12 is necessary to maintain a persistent Th1-recall response. Furthermore, administration of IL-12 to actively immunized mice, in which Th2-associated responses were established, had a significant effect on IgG2a synthesis and a modest effect on IgE levels, also down-regulation of IL-5 production, and markedly increased interferon-gamma production and abolished recruitment of eosinophils. Therefore, these data indicate that IL-12 can inhibit antigen-induced eosinophil infiltration into airways, despite the existence of a Th2-associated response. Taken together, these studies suggest that IL-12 may be useful as an immunotherapeutic agent in the treatment of such pulmonary allergic disorders as bronchial asthma.

Glucocorticoid resistance caused by reduced expression of the glucocorticoid receptor in cells from human vascular lesions

Mechanisms that control the balance between cell proliferation and death are important in the development of vascular lesions. Rat primary smooth muscle cells were 80% inhibited by low microgram doses of hydrocortisone (HC) and 50% inhibited by nanogram concentrations of transforming growth factor-beta1 (TGF-beta1), although some lines acquired resistance in late passage. However, comparable doses of HC, or TGF-beta1, failed to inhibit most human lesion-derived cell (LDC) lines. In sensitive LDC, HC (10 microg/mL) inhibited proliferation by up to 50%, with obvious apoptosis in some lines, and TGF-beta1 inhibited proliferation by more than 90%. Collagen production, as measured by [3H]proline incorporation or RIA for type III pro-collagen, was either unaffected or increased in the LDCs by HC. These divergent responses between LDC lines were partially explained by the absence of the glucocorticoid receptor (GR) and heat shock protein 90 mRNA in 10 of 12 LDC lines, but the presence of the mineralocorticoid receptor and 11beta-hydroxysteroid dehydrogenase type II. Western blot analysis confirmed the absence of the GR protein in cells lacking GR mRNA. Immunohistochemistry of human carotid lesions showed high levels of GR in the tunica media, but large areas lacking GR in the fibrous lesion. Considering the absence of the GR in most lines, the effects of HC may be elicited through the mineralocorticoid receptor. Functional resistance to the antiproliferative and antifibrotic effects of HC may contribute to excessive wound repair in atherosclerosis and restenosis.

BLNK required for coupling Syk to PLC gamma 2 and Rac1-JNK in B cells

Signaling through the B cell receptor (BCR) is essential for B cell function and development. Despite the key role of Syk in BCR signaling, little is known about the mechanism by which Syk transmits downstream effectors. BLNK (B cell LiNKer protein), a substrate for Syk, is now shown to be essential in activating phospholipase C (PLC)gamma 2 and JNK. The BCR-induced PLC gamma 2 activation, but not the JNK activation, was restored by introduction of PLC gamma 2 membrane-associated form into BLNK-deficient B cells. As JNK activation requires both Rac1 and PLC gamma 2, our results suggest that BLNK regulates the Rac1-JNK pathway, in addition to modulating PLC gamma 2 localization.

[Therapeutic effect of recombinant interferon alpha-2b on hemorrhagic fever with renal syndrome]

To study the therapeutic effect of recombinant interferon alpha-2b(rIFN alpha-2b) on cases of hemorrhagic fever with renal syndrome(HFRS) in early stage, 146 cases of HFRS in feverish stage and within five days of onset were randomly divided into two groups: the treatment and the control, each group included 73 cases. The control group was given the traditional combined therapy with a predominance of balanced solution, the treatment group was given rIFN alpha-2b 1 x 10(6)U per day, i.m., for three days. The treatment group showed much better effects in improving the viremia, the clinical conditions, skipping phases, restoring kidney function and platelet account, decreasing complications than the control group (P < 0.05). All the patients of the treatment group recovered, and four patients of the control group died, accounting for 5.47%. No side-effect resulting from rIFN alpha-2b was found. Administration of rIFN alpha-2b to patients with HFRS within five days of onset could lighten the organ lesions, shorten the course of disease and raise the curative rate.

[Sensitivity of cationic polymer Eudragit RL to electrolytes and its effect on drug release from Eudragit RL matrix]

The swelling behavior of acrylic polymer Eudragit RL in different concentration and species of electrolyte aqueous media, and the effect of media and polymer swelling on drug release from Eudragit RL matrix system were investigated with nifedipine, chlorpheniramine maleate and indomethacin as model drugs. It was found that Eudragit RL was sensitive to the electrolytes in aqueous media. The swelling of Eudragit RL decreased with increasing electrolyte concentration and was significantly affected by the electrolyte species. The swelling behavior was reversible. The release of 3 drugs from Eudragit RL matrix was remarkably affected by the electrolytes in the media. The rates of release of nifedipine and chlorpheniramine maleate from the polymer matrices were controlled by the polymer swelling behavior, and the rate of release correlated well with the swelling behavior. However, the rates of release of indomethacin from the Eudragit RL matrix were controlled not only by the polymer swelling but also by the drug displacement by the medium anion, which was attributed to the presence of an interaction between indomethacin and Eudragit RL.

BLNK: a central linker protein in B cell activation

Linker or adapter proteins provide mechanisms by which receptors can amplify and regulate downstream effector proteins. We describe here the identification of a novel B cell linker protein, termed BLNK, that interfaces the B cell receptor-associated Syk tyrosine kinase with PLCgamma, the Vav guanine nucleotide exchange factor, and the Grb2 and Nck adapter proteins. Tyrosine phosphorylation of BLNK by Syk provides docking sites for these SH2-containing effector molecules that, in turn, permits the phosphorylation and/or activation of their respective signaling pathways. Hence, BLNK represents a central linker protein that bridges the B cell receptor-associated kinases with a multitude of signaling pathways and may regulate the biologic outcomes of B cell function and development.

Modification of the clinical course of intestinal microsporidiosis in acquired immunodeficiency syndrome patients by immune status and anti-human immunodeficiency virus therapy

The clinical course of 37 Enterocytozoon bieneusi-infected acquired immunodeficiency syndrome patients with diarrhea was studied. Parasite clearance was seen in 15 patients (40.5%). Clearance of E. bieneusi resulted in a 25-100% reduction in episodes of diarrhea, suggesting that microsporidia are true pathogens. Univariate and multivariate proportional hazards analyses revealed that peripheral blood CD4 cell counts > or = 100/mm3, the use of two or more antiretroviral medications, and use of a protease inhibitor were statistically associated with decreased time to clearance of E. bieneusi. Specific anti-microsporidial therapy (albendazole) was not associated with parasite eradication. Factors related to immunocompetence and human immunodeficiency virus suppression appeared to be important in the clearance of E. bieneusi.

[Development of gas-liquid exchanger for complex retina pare operation]

A gas-liquid exchanger apparatus was developed for the complex operation of the retinal detachment. The bacteria-free gas can be obtained by using this apparatus. The pressure of the gas is successively adjustable, from 0 to 100 mmHg. The apparatus is very suitable for exchanging gas for liquid in the retinal surgery and raises the effect of the operation.

Identification of two tyrosine phosphoproteins, pp70 and pp68, which interact with phospholipase Cgamma, Grb2, and Vav after B cell antigen receptor activation

Tyrosine phosphorylation of cellular proteins mediates the assembly and localization of effector proteins through interactions facilitated by modular Src homology 2 (SH2) and phosphotyrosine binding domains. We describe here two tyrosine-phosphorylated proteins with Mr values of 70,000 and 68,000 that interact with Grb2, phospholipase C (PLCgamma1 and PLCgamma2), and Vav after B cell receptor cross-linking. The interaction of pp70 and pp68 with PLC and Vav is mediated by the carboxyl-terminal SH2 domain of PLC and the SH2 domain of Vav. In contrast, the interaction of pp70 and pp68 with Grb2 requires cooperative binding of the SH2 and SH3 domains of Grb2. Western blot analysis demonstrated that neither pp70 nor pp68 represented the recently described linker protein SLP-76, which binds Grb2, PLC, and Vav in T cells after T cell receptor activation. Moreover, SLP-76 protein was not detected in a number of B cell lines or in normal mouse B cells. Hence, we propose that pp70 and pp68 likely represent B cell homologs of SLP-76 which facilitate and coordinate B cell activation.

[A research on the determination of trace secondary amines by reversed-phase high performance liquid chromatography with electrochemical detection]

A new sensitive method for determination of ultratrace secondary amines has been described. It is the first time to use dansyl chloride as electrochemical derivatization reagent for secondary amines. The optimum experimental conditions have been established. At first, trace secondary amines were derivatised with dansyl chloride at 40 degrees C for 30 minutes, then the mixture was injected and separated on a Perkin-Elmer/HS-3 C18 (83 mm x 4.6 mm i.d. 3 microm) column with methanol aqueous solution (70/30, pH 3.3) which contained 20 mmol/L potassium biphthalate buffer as mobile phase and detected with electrochemical detection at E = +1.1 V (Ag/AgCl). The calibration curves were linear in the range of 0.225-54 pg for dimethylamine; 1.1-264 pg for diethylamine, 0.43-102 pg for piperidine. The detection limits were 0.024, 0.60, 0.090 pg respectively and the coefficients of variation were less than 3.5% (n = 7).

Barrier effects of hyperosmolar signaling in microvascular endothelium of rat lung

We determined the effects of hyperosmolarity on lung microvascular barrier properties by means of the split-drop technique in single venular capillaries of the isolated, blood-perfused rat lung. Using isosmolar and hyperosmolar test solutions (colloid osmotic pressure = 21 cm H2O), we quantified transcapillary flux at a fixed absorptive capillary pressure, and the capillary hydraulic conductivity (Lp). Loss of barrier function was indicated in flux reversal from isosmolar absorption to hyperosmolar filtration (P < 0. 01), and by hyperosmolarity-induced Lp increase (P < 0.01). Barrier recovery after a 1-min hyperosmolar exposure was delayed > 25 min. The flux reversal was blocked by the tyrosine kinase inhibitors genistein and MDC (P < 0.01). Genistein also inhibited the Lp increase (P < 0.01). Immunoblots of hyperosmolarity-exposed, cultured rat lung microvascular endothelial cells (RLMEC) and of endothelial cells freshly harvested from lungs given hyperosmolar infusions indicated a genistein-inhibitable enhancement of protein tyrosine phosphorylation. Immunoprecipitation studies indicated tyrosine phosphorylation of the mitogen activated protein kinases (MAPK) ERK1 and ERK2 and the adaptor protein Shc in lysates of RLMEC exposed to hyperosmolar conditions. We conclude that in lung venular capillaries hyperosmolarity deteriorates barrier properties, possibly by inducing tyrosine phosphorylation of endothelial proteins.

Cerebral malacia caused by Takayasu's arteritis--a case report

This paper reports an unusual autopsy case, a 27-year-old man, who died from severe cerebral malacia. It is well known to our legal medical workers that cerebral malacia could be caused by injury and/ or disease. By coincidence, the deceased was subjected to head injury nine months prior to death, so differential diagnosis of cerebral malacia is very important in this case. His cerebral malacia was finally confirmed to be caused by Takayasu's arteritis not by his head injury by means of autopsy and pathological examination.

Viscous fluid expulsion in the evaluation of the constipated patient

PURPOSE

The aim of this study was to evaluate a viscous fluid expulsion test as a method for quantifying rectal outlet obstruction.

METHODS

We examined the ability of 30 severely constipated patients and 40 healthy control subjects to expel a viscous fluid simulating feces.

RESULTS

Constipated patients with defecographic rectal retention expelled a significant lower viscous fluid volume compared with controls (P < 0.0001). Considering the viscous fluid expulsion test to be positive if the patient expelled less than 160 ml of fluid (lower 95 percent confidence value in healthy controls) and using the presence of defecographic rectal outlet obstruction as a reference, the predictive value of a negative viscous fluid expulsion test was 100 percent, the predictive value of a positive test was 67 percent, and sensitivity and specificity was 100 percent and 82 percent, respectively. The viscous fluid test identified symptomatic outlet obstruction in almost twice as many patients as did defecography. Some patients, however are-despite their obstructive symptoms-able to evacuate their rectum when examined in the laboratory.

CONCLUSION

The viscous fluid expulsion test is a simple, reproducible, nonionizing, and low-cost method of quantifying rectal outlet obstruction. A positive test result should lead to a defecography, whereas a negative test result renders defecography dispensable and spares the patient from pelvic radiation.

The HypB protein from Bradyrhizobium japonicum can store nickel and is required for the nickel-dependent transcriptional regulation of hydrogenase

The HypB protein from Bradyrhizobium japonicum is a metal-binding GTPase required for hydrogenase expression. In-frame mutagenesis of hypB resulted in strains that were partially or completely deficient in hydrogenase expression, depending on the degree of disruption of the gene. Complete deletion of the gene yielded a strain (JH delta Eg) which lacked hydrogenase activity under all conditions tested, including the situation as bacteroids from soybean nodules. Mutant strain JH delta 23H lacking only the N-terminal histidine-rich region (38 amino acids deleted, 23 of which are His residues) expressed partial hydrogenase activity. The activity of strain JH delta 23H was low in comparison to the wild type in 10-50 nM nickel levels, but could be cured to nearly wild-type levels by including 50 microM nickel during the derepression incubation. Studies on strains harbouring the hup promoter-lacZ fusion plasmid showed that the complete deletion of hypB nearly abolished hup promoter activity, whereas the histidine deletion mutant had 60% of the wild-type promoter activity in 50 microM NiCl2. Further evidence that HypB is required for hup promoter-binding activity was obtained from gel-shift assays. HypB could not be detected by immunoblotting when the cells were cultured heterotrophically, but when there was a switch to microaerobic conditions (1% partial pressure O2, 10% partial pressure H2) HypB was detected, and its expression preceded hydrogenase synthesis by 3-6 h. 63Ni accumulation by whole cells showed that both of the mutant strains accumulate less nickel than the wild-type strain at all time points tested during the derepression incubation. Wild-type cultures that received nickel during the HypB expression-specific period and were then washed and derepressed for hydrogenase without nickel had activities comparable to those cells that were derepressed for hydrogenase with nickel for the entire time period. In contrast to the wild type, strain JH delta 23H cultures supplied with nickel only during the HypB expression period achieved hydrogenase activities that were 30% of those cultures supplied with nickel for the entire hydrogenase derepression period. These results indicate that the loss of the metal-binding area of HypB causes a decrease in the ability of the cells to sequester and store nickel for later use in one or more hydrogenase expression steps.

[Determination of stability constants of metal complexes by on-column derivatization reversed phase high performance liquid chromatography]

The stability constant of metal complexes is an important chemical parameter. There are many methods for its determination, but few analyst has calculated it with high performance liquid chromatography (HPLC). In the present paper a new model for determining the stability constant of metal complexes with on-column derivatization reversed phase HPLC has been proposed where complexation forming reactions are taking place in the mobile phase. Based on the retention mechanism of neutral complexes, the equation for calculation is deduced. It has been applied to some cations (Hg2+, Pb2+, Ni2+, Cu2+, Ag+, Hg+)-DDTC complexes. The results are in agreement with those given in the literature. Then, a simple, practical and rapid graphic method is studied for monovalent metal complexes. The stability constants can be obtained simply as the quotient of the line slope and the axis intercept of the linear dependence. The relations derived in this paper may be used not only for calculating the stability constants from chromatographic measurements but also for optimizing the process of separation based on the values of the stability constants available in literature.

Recognition of unique carboxyl-terminal motifs by distinct PDZ domains

The oriented peptide library technique was used to investigate the peptide-binding specificities of nine PDZ domains. Each PDZ domain selected peptides with hydrophobic residues at the carboxyl terminus. Individual PDZ domains selected unique optimal motifs defined primarily by the carboxyl terminal three to seven residues of the peptides. One family of PDZ domains, including those of the Discs Large protein, selected peptides with the consensus motif Glu-(Ser/Thr)-Xxx-(Val/Ile) (where Xxx represents any amino acid) at the carboxyl terminus. In contrast, another family of PDZ domains, including those of LIN-2, p55, and Tiam-1, selected peptides with hydrophobic or aromatic side chains at the carboxyl terminal three residues. On the basis of crystal structures of the PSD-95-3 PDZ domain, the specificities observed with the peptide library can be rationalized.

Three-dimensional modeling and molecular evolution of Matrix Cell Adhesion Molecule #2: MAT-CAM 2

Our research group has recently reported the partial amino acid sequence of an aortic adventitial collagen-associated fibrillar protein, which may be the target of an autoimmune response in patients with abdommal aortic aneurysms (AAA). Its apparent molecular weight is approximately 40 kDa, so we have named it aneurysm-associated antigenic protein-40 kDa (AAAP-40). It has similarities to microfibril-associated glycoprotein-36 kDa (MAGP-36), which was reported by Kobayashi et al. to have a tissue distribution limited to the aorta in pig; unlike other microfibrillar proteins which appear to distribute ubiquitously throughout the body with elastin. Accordingly, if AAAP-40 is the human homolog of MAGP-36, it would explain how an autoimmune reaction against this protein might have consequences more or less limited to the aorta and its branches.

Ca2+ waves in lung capillary endothelium

Although cytosolic Ca2+ importantly regulates organ function, lung microvascular [Ca2+]i regulation remains poorly understood because of the lack of direct in situ quantification. In the present study, we report the first endothelial [Ca2+]i quantification by the fura 2 method in microscopically imaged venular capillaries of the isolated blood-perfused rat lung. Sequential images indicated the presence of intercellular Ca2+ waves that spontaneously originated from pacemaker endothelial cells and then spread for short distances along the capillary wall, inducing synchronous endothelial [Ca2+]i oscillations. Fast Fourier analyses of the oscillations revealed a dominant wave component with an amplitude of 37 nmol/L, frequency of 0.4 min-1, and velocity of 5 microns/s. The intracellular Ca2+ wave was unaffected by blood flow stoppage or by infusions of Ca(2+)-containing or Ca(2+)-free dextran. Inhibition of the wave by thapsigargin in Ca(2+)-free dextran and by the gap junction uncoupler, heptanol, indicated that it was generated by endosomal Ca2+ release in the pacemaker cell and was propagated by gap junctional communication. In the presence of histamine, enhancement of the wave accounted for a significant component of the coordinated [Ca2+]i increase in the capillary segment. No intercellular Ca2+ waves were evident in adjoining alveolar epithelial cells. Our findings indicate a novel mechanism of [Ca2+]i regulation in the lung capillary under both resting and stimulated conditions. Pacemaker-induced Ca2+ waves, generated intracellularly by unknown initiating mechanisms, communicated to adjoining cells to determine [Ca2+]i profiles in short interbranch segments of capillary walls.

Phosphorylation of SLP-76 by the ZAP-70 protein-tyrosine kinase is required for T-cell receptor function

Two families of tyrosine kinases, the Src and Syk families, are required for T-cell receptor activation. While the Src kinases are responsible for phosphorylation of receptor-encoded signaling motifs and for up-regulation of ZAP-70 activity, the downstream substrates of ZAP-70 are unknown. Evidence is presented herein that the Src homology 2 (SH2) domain-containing leukocyte protein of 76 kDa (SLP-76) is a substrate of ZAP-70. Phosphorylation of SLP-76 is diminished in T cells that express a catalytically inactive ZAP-70. Moreover, SLP-76 is preferentially phosphorylated by ZAP-70 in vitro and in heterologous cellular systems. In T cells, overexpression of wild-type SLP-76 results in a hyperactive receptor, while expression of a SLP-76 molecule that is unable to be tyrosine-phosphorylated attenuates receptor function. In addition, the SH2 domain of SLP-76 is required for T-cell receptor function, although its role is independent of the ability of SLP-76 to undergo tyrosine phosphorylation. As SLP-76 interacts with both Grb2 and phospholipase C-gamma1, these data indicate that phosphorylation of SLP-76 by ZAP-70 provides an important functional link between the T-cell receptor and activation of ras and calcium pathways.

Hydrogen uptake hydrogenase in Helicobacter pylori

The peptic ulcer-causing bacterium Helicobacter pylori was found to contain an H2-uptake hydrogenase activity coupled to whole cell (aerobic) respiration. The activity was localized to membranes which functioned in the H2-oxidizing direction with a variety of artificial and physiological electron acceptors of positive redox potential. Immunoblotting of H. pylori membrane components with anti (B. japonicum) hydrogenase large and small subunit-specific antisera identified H. pylori hydrogenase peptides of approximately 65 and 26 kDa respectively, and H. pylori genomic DNA fragments hybridizing to the (B. japonicum) hydrogenase structural genes were identified. The membrane-bound activity was subject to anaerobic activation, like many NiFe hydrogenases. Difference absorption spectral studies revealed absorption peaks characteristic of b and c-type cytochromes, as well as of a bd-type terminal oxidase in the H. pylori H2-oxidizing membrane-associated respiratory chain.

Different properties of the atrial G protein-gated K+ channels activated by extracellular ATP and adenosine

Extracellular ATP (ATPo) and adenosine activate G protein-gated inwardly rectifying K+ currents in atrial cells. Earlier studies have suggested that the two agonists may use separate pathways to activate the K+ current. Therefore, we examined whether the K+ channels activated by the two agonists have different properties under identical ionic conditions. In cell-attached patches, K+ channels activated by 100 microM ATP in the pipette had a single-channel conductance and mean open time of 32.0 +/- 0.2 pS and 0.5 +/- 0.1 ms, respectively, compared with 31.3 +/- 0.3 pS and 0.9 +/- 0.1 ms for the K+ channels activated by adenosine (140 mM KCl). With ATPo as the agonist, the K+ channel activity in cell-attached patches was approximately threefold lower than that in inside-out patches with 100 microM GTP in the bath. Applying ATP to the cytoplasmic side of the membrane (ATPi) produced a biphasic concentration-dependent effect on channel activity: an increase at low [mean affinity constant (K0.5) = 190 microM] and a decrease at high (K0.5 = 1.3 mM) concentrations. In contrast, with adenosine as the agonist, K+ channel activity in cell-attached patches was approximately fourfold greater than that in inside-out patches with 100 microM GTP in the bath. In inside-out patches, ATPi only augmented the K+ channel activity (K0.5 = 32 microM). These results show that although both ATPo and adenosine activate kinetically similar K+ channels in atrial cells, the channels are regulated differently by intracellular nucleotides.

Ligation of endothelial alpha v beta 3 integrin increases capillary hydraulic conductivity of rat lung

Complement-mediated pulmonary edema results from increases in lung capillary hydraulic conductivity (Lp), possibly by receptor-mediated mechanisms. We considered the Lp effects of vitronectin and the vitronectin-containing complement complex SC5b-9, which ligate the integrin alpha v beta 3. Vitronectin, SC5b-9, and SC5b-9-enriched zymosan-activated serum all rapidly increased Lp, as determined by the split-drop technique in single lung capillaries of rat lung. The Lp increases were inhibited by a monospecific (LM609) and a polyclonal (R838) antibody against the alpha v beta 3 integrin but not by an irrelevant monoclonal antibody isotype matched with LM609, by a monoclonal antibody against the alpha v beta 5 integrin, or by preimmune rabbit serum. Vitronectin monomers failed to increase Lp. The tyrosine kinase blockers genistein and methyl 2,5-dihydroxycinnamate caused significant concentration-dependent inhibitions of Lp increases due to vitronectin and zymosan-activated serum. By contrast, the protein kinase C blocker calphostin C had no major effect. We conclude that (1) multivalent ligation of the luminally located alpha v beta 3 integrin of lung capillary endothelium increases transcapillary liquid flux, and (2) the dominant signal transduction pathway for this effect occurs through tyrosine kinase activation.

Effects of TNF alone or in combination with chemotherapeutic agents on human ovarian cancers in vitro and in nude mice

Using the tetrazolium (MTT) assay, we examined the cytotoxicities of recombinant human tumor necrosis factor (rhTNF) and five chemotherapeutic agents, namely CTX, 5-FU, VCR, DDP and KSM, on human ovarian cancer cell lines OVCAR3 and CAOV3. The results showed that the cytotoxicities of rhTNF at concentrations of 50-50,000 U/ml on OVCAR3 cell line and CAOV3 cell line exposed to rhTNF for 24 hours were from 14.2% +/- 6.8% to 67.2% +/- 3.0% and from 8.2% +/- 4.3% to 60.9% +/- 1.3%, respectively. The cytotoxicities of all five chemotherapeutic agents tested on the two cell lines were much lower than that of rhTNF. We also studied the combined antitumor potential of rhTNF with the five chemotherapeutic agents and the results showed that there were various degrees of synergism in cytotoxicities of rhTNF in combination with DDP or KSM on the two cell lines. Based on experiments in vitro, the in vivo antitumor activities of rhTNF, both alone and in combination with KSM, were examined in OVCAR3 cancer transplanted in nude mice. The results showed a considerable antitumor effect of rhTNF when it was used alone and a marked synergistic effect when it was used in combination with KSM on the xenograft tumors.

Soluble ligands of the alpha v beta 3 integrin mediate enhanced tyrosine phosphorylation of multiple proteins in adherent bovine pulmonary artery endothelial cells

Binding of substrate-bound extracellular matrix proteins to cell surface integrins results in a variety of cellular responses including adhesion, cytoskeletal reorganization, and gene expression. We have previously shown that addition of soluble SC5b-9, the complement-vitronectin complex, resulted in an RGD-dependent increase in lung venular hydraulic conductivity (Ishikawa, S., Tsukada, H., and Bhattacharya, J. (1993) J. Clin. Invest. 91, 103-109). To identify specific integrin(s) and signal transduction pathways that are responsive to soluble vitronectin-containing ligands, we exposed confluent bovine pulmonary artery cells to purified soluble human mono- or multimeric vitronectin, or SC5b-9, and determined the extent of endothelial cell protein tyrosine phosphorylation. Monomeric vitronectin (Vn) did not induce enhanced protein tyrosine phosphorylation. However, multimeric Vn and SC5b-9 elicited time- and concentration-dependent increases in tyrosine phosphorylation of numerous proteins. Antiserum against vitronectin, RGD peptides, and monoclonal and polyclonal antibodies against the alpha v beta 3 integrin blocked the vitronectin- or SC5b-9-induced enhanced accumulation of tyrosine phosphoproteins, while antibodies against beta 1 integrins and the alpha v beta 5 integrin did not. Clustering of the alpha v beta 3 integrin using monoclonal antibody LM609 caused a pattern of enhanced tyrosine phosphorylation similar to that caused by multimeric Vn and SC5b-9, suggesting that aggregation of alpha v beta 3 was critical for signaling. Among the proteins that underwent enhanced tyrosine phosphorylation in response to vitronectin were the cytoskeletal proteins paxillin, cortactin, and ezrin, as well as the SH2 domain-containing protein Shc, and p125FAK. We conclude that ligation of the alpha v beta 3 integrin by soluble ligands promotes enhanced phosphorylation of several proteins implicated in tyrosine kinase signaling and suggest that this pathway may be important in inflammatory states which are accompanied by accumulation of SC5b-9.

HypB protein of Bradyrhizobium japonicum is a metal-binding GTPase capable of binding 18 divalent nickel ions per dimer

Bradyrhizobium japonicum hypB encodes a protein containing an extremely histidine-rich region (24 histidine residues within a 39-amino-acid stretch) and guanine nucleotide-binding domains. The product of the hypB gene was overexpressed in Escherichia coli and purified by Ni(2+)-charged metal chelate affinity chromatography (MCAC) in a single step. In SDS/PAGE, HypB migrated at 38 kDa--slightly larger than the calculated molecular mass (32.8 kDa). Purified HypB has GTPase activity with a kcat of 0.18 min-1 and a Km for GTP of 7 microM, and it has dGTPase activity as well. HypB exists as a dimer of molecular mass 78 kDa in native solution as determined by fast protein liquid chromatography on Superose 12. It binds 9.0 +/- 0.14 divalent nickel ions per monomer (18 Ni2+ per dimer) with a Kd of 2.3 microM; it also binds Zn2+, Cu2+, Co2+, Cd2+, and Mn2+. In-frame deletion of the histidine-rich region (deletion of 38 amino acids including 23 histidine residues) resulted in a truncated HypB that did not bind to the MCAC column, whereas in-frame deletion of 14 amino acids including 8 histidine residues within HypB resulted in a truncated HypB that still bound to the column. The results indicate that the histidine residues within the histidine-rich region of HypB are involved in metal binding.

A study of immunoactivity of retinal S-antigen in retinoblastoma

PURPOSES

To study retinal S-antigen expression in human retinoblastoma and assess if there is a correlation between S-antigen immunoactivity and degree of retinoblastoma cell differentiations.

METHODS

Ten cases of Chinese retinoblastoma parafin-embedded tissues were applied for this study. A strain of monoclonal antibody,MabA9C6, which defines an epitope in S-antigen retained in fixed-tissue sections, was used to study S-antigen expression in 10 cases of retinoblastomas. S-antigen was localized by the biotinavidin indirect immunoperoxidase technique and purified MabA9C6 ascites fluid was used with 1:100 dilution. The whole procedure could be finished within a few hours.

RESULTS

The S-antigen immunoactivity was observed in different patterns: the "normal" photoreceptor elements incorporated in 3 cases of growing tumors; 3 of 4 Fleurettes and E-W rosettes; and scattered tumor cells in 50% of the cases.

CONCLUSIONS

The result suggests that the expression of S-antigen in retinoblastoma may be used to assess the degree of tumor differentiation as another tumor marker in retinoblastoma.

Structure and function of the mouse insulin-like growth factor binding protein 5 gene promoter

The actions of insulin-like growth factors I and II (IGF-I and -II) are modulated by interactions with one or more of a family of secreted IGF binding proteins (IGFBPs). IGFBP-5, the most conserved of the six known IGFBPs, is a 252-amino-acid protein that has been shown both to potentiate and inhibit IGF action. In previous studies, we have cloned and characterized the mouse IGFBP-5 gene and demonstrated that it is expressed in a hierarchical pattern in different adult mouse tissues and during rodent embryonic development. In this report, we describe the initial analysis of the IGFBP-5 gene promoter. By transient gene transfer studies, we show the orientation-specific activity of DNA fragments containing from 31 to 4,100 bp from the 5'-flanking region of the mouse IGFBP-5 gene in directing expression of the heterologous reporter gene luciferase in Hep G2 cells. DNA fragments with only 156 bp of 5'-flanking sequence mediated over 60% of maximal promoter activity, and a segment containing the TATA box and the first 120 bp of exon 1 still conferred some promoter function. Within the highly active 156-bp region, we identified a 37-bp segment from -70 to -34 that exhibited specific binding in DNase I footprinting and gel-mobility shift experiments with Hep G2 nuclear protein extracts. The footprinted region, which is almost completely conserved in the rat and human IGFBP-5 genes, was responsible for at least 70% of the activity of the intact promoter, as evidenced by the deleterious consequences of small internal deletions within this sequence on promoter function.(ABSTRACT TRUNCATED AT 250 WORDS)