Radioimmunoassay of nicotine.

A sensitive and specific radioimmunoassay of nicotine was developed using antisera raised against 6-(p-aminobenzamido) nicotine coupled to bovine serum albumin. Inhibition studies with various nicotine analogues revealed that the antisera are highly specific for both the N-methylpyrrolidine ring and the pyridine ring of nicotine, and especially for the structural changes of the former. The use of these antisera in an assay of nicotine in biological fluids is desirable, since the pyrrolidine ring of nicotine is first metabolized in vivo and antibodies must, therefore, discriminate nicotine from other nicotine metabolites.     

Interaction of monoclonal antibodies with alpha-bungarotoxin and (-)-nicotine binding sites in goldfish brain. Identification of putative nicotinic acetylcholine receptor subtypes

Monoclonal antibodies raised against the nicotinic acetylcholine receptor of Electrophorus electricus electroplaque have been used as probes to characterize putative nicotinic acetylcholine receptors in goldfish brain. One monoclonal antibody (mAb), mAb 47, recognized a protein which binds both (-)-[3H]nicotine and 125I-alpha-bungarotoxin with high affinity. Another monoclonal antibody (mAb 172) recognized a protein which binds (-)-[3H]nicotine but not 125I-alpha-bungarotoxin. Both antibodies precipitated a protein(s) (biosynthetically labeled with [35S]methionine) in the absence, but not in the presence, of excess purified nicotinic acetylcholine receptor from Torpedo nobiliana. The dilution of mAb 47 that precipitated half of the maximum amount of 125I-alpha-bungarotoxin binding protein was the same as that which precipitated half of the maximum amount of (-)-[3H]nicotine binding activity. When used in combination, the two antibodies precipitated more (-)-[3H]nicotine radioactivity than either antibody alone. The (-)-[3H]nicotine and 125I-alpha-bungarotoxin binding component-mAb complexes were characterized by sucrose density centrifugation. In the presence of either mAb 172 or 47, the (-)-[3H] nicotine binding component migrated further into the gradient, but only mAb 47 shifted the 125I-alpha-bungarotoxin peak. Incubation of solubilized brain extract with alpha-bungarotoxin-coupled Sepharose reduced the amount of (-)-[3H]nicotine radioactivity precipitated by mAb 47 but not by mAb 172. These data suggest that the antibodies may recognize distinct subtypes of (-)-nicotine binding sites in goldfish brain, one subtype which binds both 125I-alpha-bungarotoxin and (-)-[3H]nicotine and a second subtype which binds only (-)-[3H] nicotine.     

Monoclonal anti-idiotypic antibodies that recognize the binding site for nicotine on rat brain receptor

Anti-idiotypic monoclonal antibodies have been prepared that represent the internal image of nicotine and are specific for the nicotine binding site on rat brain receptor. Specificity of these antibodies for the combining site on anti-nicotine was demonstrated by their ability to inhibit binding of monoclonal anti-nicotine to immobilized nicotine-polylysine. Furthermore, purified rat brain nicotine receptor but not acetylcholine receptor from fish electric organ effectively competed with anti-nicotine for immobilized nicotine and for immobilized anti-idiotype. Only 9 pmoles of naturally occurring (-)-nicotine inhibited idiotype-anti-idiotype binding by 50% whereas 11 times more (+)-nicotine was required. Acetylcholine, several cholinergic agonists and antagonists, nicotine metabolites, and other structurally related compounds were poor inhibitors.     

Conjugate of bovine serum albumin with nicotine

The preparation and characterization of a nicotine-albumin conjugate are reported. The nicotine derivative, 6-(p-aminobenzamido)nicotine, which was coupled to bovine serum albumin(BSA), was synthesized by the following sequence; $\text{1}$-nicotine→6-aminonicotine→6-(p-nitrobenzamido)nicotine→6-(p-aminobenzamido)nicotine. Thirty molecules of conjugated nicotine per molecule of BSA were distinguished by the determination of 6-aminonicotine after hydrolysis. The distribution of the conjugated nicotine on BSA was examined by the stoichiometry of the composed amino acids before and after conjugation, and also by the electrophoretic behavior of the conjugated BSA on a polyacrylamide gel.     

Stereospecificity of 2-methylpiperidine binding to a nicotinic up-regulatory site in the rat brain P2 preparation

(+/-)-2-Methylpiperidine has a high degree of specificity in enhancing the binding of (-)-[3H]nicotine in the rat brain P2 preparation. (-)- and (+)-2-Methylpiperidine have been resolved. The (+) but not the (-) isomer increased the binding of (-)-[3H]nicotine. The two isomers were equally effective in inhibiting the binding of (-)-[3H]nicotine in high concentrations. These data provide additional support for a stereospecific nicotinic up-regulatory site.     

Antigenic determinants shared between HLA-A, −B, −C antigens and H-2 class I molecules modified by bovine beta-2 microglobulin

The specificity of the mouse class I-specific antibody COB6-3 was examined in detail. It was found to react with the mouse class I molecules H-2D^b, K^d, and Qa-2, and with human HLA-A, –B, –C antigens. The specificity pattern of COB6-3, despite its different origin, was similar to that of the monomorphic HLA class I-specific antibody W6/32. Cross-inhibition studies show that on human cells the antigenic determinants recognized by the two antibodies are situated close together and may be identical. On mouse cells, reactivity of both antibodies was generated upon replacement of mouse beta-2 microglobulin (B2m) with its bovine counterpart, but differences in specificity were observed using human B2m.Abbreviations used in this paper B2m beta-2 microglobulin - BSA bovine serum albumin - FCS fetal calf serum - FITC fluorescein isothiocyanate - MHC major histocompatibility complex - PBL peripheral blood lymphocytes - PBS phosphate-buffered saline - SDS-PAGE sodium dodecyl sulfate-polyacrylamide gel electrophoresis     

Anti-alpha-galactosyl antibodies recognizing epitopes terminating with alpha1,4-linked galactose: human natural and mouse monoclonal anti-NOR and anti-P1 antibodies

The rare NOR erythrocytes, which are agglutinated by most human sera, contain unique glycosphingolipids (globoside elongation products) terminating with the sequence Galalpha1-4GalNAcbeta1-3Gal- recognized by common natural human antibodies. Anti-NOR antibodies were isolated from several human sera by affinity procedures, and their specificity was tested by inhibition of antibody binding to NOR-tri-polyacrylamide (PAA) conjugate (ELISA) by the synthetic oligosaccharides, Galalpha1-4GalNAcbeta1-3Gal (NOR-tri), Galalpha1-4GalNAc (NOR-di), Galalpha1-4Galbeta1-3Galbeta1-4Glc ((Gal)3Glc), and Galalpha1-4Gal (P1-di). Two major types of subspecificity of anti-NOR antibodies were found. Type 1 antibodies were found to react strongly with (Gal)3Glc and NOR-tri and weakly with P1-di and NOR-di, which indicated specificity for the trisaccharide epitope Galalpha1-4Gal/GalNAcbeta1-3Gal. Type 2 antibodies were specific to Galalpha1-4GalNAc, because they were inhibited most strongly by NOR-tri and NOR-di and were not (or very weakly) inhibited by (Gal)3Glc and P1-di. Monoclonal anti-NOR antibodies were obtained by immunizing mice with NOR-tri-human serum albumin (HSA) conjugate and were found to have type 2 specificity. All anti-NOR antibodies reacted specifically with NOR glycolipids on thin-layer plates. The cross-reactivity of type 1 anti-NOR antibodies with Galalpha1-4Gal drew attention to a possible antigenic relationship between NOR and blood group P system glycolipids. The latter glycolipids include Pk (Galalpha1-4Galbeta1-4Glc-Cer) present in all normal erythrocytes and P1 (Galalpha1-4Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc-Cer) present only in P1 erythrocytes. Sera of some P2 (P1-negative) persons contain natural anti-P1 antibodies. This prompted us to test the specificity of anti-P1 antibodies. Natural human anti-P1 isolated from serum of P2 individual and mouse monoclonal anti-P1 were best inhibited by Galalpha1-4Galbeta1-4GlcNAc (P1-tri) and did not react with NOR-tri and NOR-di. Monoclonal anti-P1 bound to Pk and P1 glycolipids and not to NOR glycolipids. These results indicated an entirely different specificity of anti-NOR and anti-P1 antibodies. Human serum samples differed in the content of anti-alpha-galactosyl antibodies, including both types of anti-NOR. In the sera of some individuals, type 1 or type 2 anti-NOR antibodies dominated, and other samples contained mixtures of both types of anti-NOR. The biological significance of these new abundant anti-alpha-galactosyl antibodies still awaits elucidation.     

Nicotinic acetylcholine receptors alpha4beta2 and alpha7 regulate myelo- and erythropoiesis within the bone marrow

Nicotine consumed upon smoking affects numerous physiological processes through nicotinic acetylcholine receptors, which mediate cholinergic regulation by the neuronal and endogenous acetylcholine. Consequently, nicotinic receptors are expressed in many non-excitable tissues including the blood. In spite of the documented effect of nicotine on hematopoiesis, little is known about the expression and role of nicotinic receptors in the course of blood cell differentiation. The aim of the present study was to investigate whether and how nicotinic receptors are involved in the development of myeloid and erythroid cells within the bone marrow. The presence of nicotinic receptors containing alpha4(beta2) and alpha7 subunits in the bone marrow cells of C57Bl/6 mice was shown by the binding of [125I]-alpha-bungarotoxin or [3H]-Epibatidine and by flow cytometry with subunit-specific antibodies or fluorescein-labeled alpha-cobratoxin. Both TER119+ (erythroid) and CD16+CD43med (myeloid) progenitor cells bound more alpha4-specific antibodies than their mature forms, while the binding of alpha-cobratoxin and alpha7-specific antibodies was also high in mature cells. According to morphological analysis, either the absence of alpha7-containing nicotinic receptors in knockout mice or their desensitization in mice chronically treated with nicotine decreased the number of myeloid and erythroid progenitors and junior cells. In contrast, the absence of beta2-containing receptors favored myelocyte generation and erythroid cell maturation. It is concluded that the development of both myeloid and erythroid cell lineages is regulated by endogenous cholinergic ligands and can be affected by nicotine through alpha7- and alpha4beta2-containing nicotinic receptors, which play different roles in the course of the cell maturation.     

Characierization of monoclonal antibodies specific for isopentenyl adenosine derivatives occurring in transfer RNA

A family of isopentenyl adenosine derivatives are naturally occurring components of transfer RNA and are involved in several different functional roles in the cell. To facilitate the study of the biochemistry of these modified nucleosides we have raised monoclonal antibodies to N⁶-(Δ²-isopentenyl)adenosine and N⁶-(4-hydroxy-3-methyl-but-2-enyl)adenosine. The antibodies show considerable specificity and three characteristic types are distinguishable. The first type have the hydroxylated derivative as the preferred antigen, the second type have isopentenyl adenosine as the preferred antigen and a third type show a specificity for all isopentenyl-containing derivatives.     

Monospecific antibodies against a synthetic peptide predicted from the alpha-3 nicotinic receptor cDNA inhibit binding of [3H]nicotine to rat brain nicotinic cholinergic receptor

Polyclonal antibodies were raised against a synthetic decapeptide (designated S3) predicted from a segment of the alpha-3 subunit cDNA (amino acid residues 130-139) encoding the rat brain nicotinic cholinergic receptor. This segment was selected because it may be proximate to the nicotine/acetylcholine-binding site of the receptor (1). By radioligand binding assays and sucrose density gradient centrifugation, these monospecific antibodies were shown to inhibit the binding of [3H]nicotine to both the large molecular weight rat brain receptor (240 kDa) and to an SDS-disaggregated nicotine-binding subunit species (80 kDa), in a dose-dependent manner. The neutralizing effect of the anti-S3 antibodies supports the view that this region of the protein is closely related to the agonist binding site.     

Nicotine-induced neuroprotection against N-methyl-D-aspartic acid or beta-amyloid peptide occur through independent mechanisms distinguished by pro-inflammatory cytokines

Nicotine, the causative agent of addiction to tobacco, can also be a neuroprotectant. Nicotine-induced neuroprotection against different toxins is imparted through pharmacologically distinct neuronal nicotinic acetylcholine receptors (nAChR) where protection against chronic N-methyl-d-aspartic acid (NMDA) exposure is through nAChRalpha7 but protection against the toxic peptide of amyloid precursor protein, Abeta25-35, is through nAChRalpha4beta2. The inflammatory cytokine tumor necrosis factor alpha (TNFalpha) is also neuroprotective, however, in the presence of nicotine, neuroprotection against NMDA is abolished. The specificity of nicotine-TNFalpha antagonism was further refined using a mouse transgenic dominant negative of nAChRalpha7 in which nicotine failed to induce neuroprotection against NMDA and antagonism of TNFalpha was absent. However, nicotine-mediated neuroprotection against Abeta25-35 was unaffected and, therefore, did not require the expression of functional nAChRalpha7s. The mechanism of TNFalpha-mediated neuroprotection and antagonism by nicotine was independent of caspase 8 activation or nuclear factor kappa B translocation in neurons but C6-ceramide addition to neuronal cultures subsequently exposed to NMDA mimicked the neuroprotective effect of TNFalpha and, like TNFalpha, it was antagonized by cotreatment with nicotine. Therefore, the neuroprotective effects of nicotine against differing toxic assaults requires distinct nAChR subtypes and proceeds through intracellular pathways that overlap with similarly different mechanisms initiated by pro-inflammatory cytokines. These results provide insight into how nicotine imparts neuroprotection and modulates inflammatory responses.     

Monoclonal antibodies to Salmonella lipopolysaccharide: anti-O-polysaccharide antibodies protect C3H mice against challenge with virulent Salmonella typhimurium

The present investigation reports the production of monoclonal antibodies to antigenic determinants of the O-polysaccharide of Salmonella typhimurium lipopolysaccharide (LPS), and assesses the effectiveness of these antibodies in protecting C3H mice against the lethal effects of Salmonella infection. Hybridomas were generated by fusing spleen cells from (BALB/c X A/J)F1 (CAF1) mice hyperimmunized by i.v. injection with acetone-killed S. typhimurium SR-11 with X63-Ag8.653 murine myeloma cells. Hybridomas producing antibodies reactive with S. typhimurium SR-11 whole cells were subcloned, and seven of the resulting clones as well as one previously described clone were selected for use in the studies reported here. Monoclonal antibodies from these eight clones were of the IgG1 (1), IgG3 (6), or IgM (1) isotype and were specific for the O-polysaccharide region of Salmonella LPS, reacting with LPS from smooth S. typhimurium SR-11 and LT-2, but not with LPS from rough S. minnesota R60 (Ra), R345 (Rb), or R595 (Re). The effectiveness of each monoclonal antibody in protecting C3H/HeN and C3H/HeJ mice against the lethal effects of Salmonella infection was evaluated by comparing the median length of survival of groups of mice given antibody by i.p. injection before i.p. challenge with virulent S. typhimurium SR-11 to that of animals that received no antibody. Three out of eight monoclonal anti-O-polysaccharide antibodies, ST-1 (IgM), 10-5-47 (IgG3), and 10-5-6 (IgG3), provided significant (p less than 0.01) protection to C3H/HeN mice challenged with approximately 10(4) LD100 of Salmonella. Only antibodies ST-1 and 10-5-6, however, extended the median length of survival of C3H/HeJ mice beyond that of infected controls. Mouse antiserum prepared against S. typhimurium SR-11 was equally protective in C3H/HeJ mice. In an attempt to understand the contribution of antibody specificity to the relative differences in the protective capacities of the monoclonal antibodies, their reactivities with several Salmonella reference strains of different classical serotypes were examined. Although some differences in reactivity against the different strains were apparent, this approach was not adequate for defining the fine specificity of these monoclonal antibodies. The results of this study provide evidence that monoclonal antibodies with specificity to the O-polysaccharide region of Salmonella LPS can protect C3H mice against challenge with the homologous bacterial strain.     

(-)6-n-Propylnicotine antagonizes the antinociceptive effects of (-)nicotine

Several 6-alkyl analogues of nicotine were examined in radioligand binding and in vivo functional assays. Although (-)6-ethylnicotine (3) binds with high affinity at nACh receptors (Ki=5.6 nM) and produces nicotine-like actions, its n-propyl homologue (-)4 (Ki=22 nM) failed to produce such effects. In fact, (-)4 antagonized the antinociceptive effects of (-)nicotine in the tail-flick assay in mice, but not the spontaneous activity or discriminative stimulus effects of (-)nicotine. Compound (-)4 appears to selectively antagonize only one of the three effects examined and is an interesting cholinergic agent for subsequent investigation.     

Effect of nicotine on vasoconstrictor and vasodilator responses in human skin vasculature

Our objective was to test the hypothesis that acute exposure of human skin vasculature to nicotine may have deleterious effects on endothelial function. Vasoconstriction and vasorelaxation in isolated perfused human skin flaps (approximately 8 x 18 cm) derived from dermolipectomy specimens were assessed by studying changes in skin perfusion pressure measured by a pressure transducer, and skin perfusion was assessed by a dermofluorometry technique (n = 4 or 5). It was observed that nicotine (10(-7) M) amplified (P < 0.05) the norepinephrine (NE)-induced concentration-dependent (10(-7)-10(-5) M) increase in skin vasoconstriction compared with the control. This amplification effect of nicotine in NE-induced skin vasoconstriction was not blocked by the nicotine-receptor antagonist hexamethonium (10(-6) M) or the cyclooxygenase inhibitor indomethacin (10(-5) M). It was also observed that ACh and nitroglycerin (NTG) elicited a concentration-dependent (10(-8)-10(-5) M) vasorelaxation in skin flaps preconstricted with 8 x 10(-7) M of NE. The vasorelaxation induced by ACh was attenuated (P < 0.05) in the presence of nicotine (10(-7) M) compared with the control. However, skin vasorelaxation induced by NTG was not affected by nicotine (10(-7) M). ACh and NTG are known to induce endothelium-dependent and -independent vasorelaxation, respectively. The present findings were interpreted to indicate that acute exposure of human skin vasculature to nicotine was associated with 1) amplification of NE-induced skin vasoconstriction and 2) impairment of endothelium-dependent skin vasorelaxation. Cyclooxygenase products and nicotine receptors blocked by hexamethonium were not involved in the amplification of NE-induced skin vasoconstriction by nicotine. These findings may provide further insight into the pathogenesis of skin vasospasm in skin flap surgery and skin ischemic disease associated with cigarette smoking or use of smokeless tobacco.     

侵袭性真菌深部感染的早期实验室诊断

目的探讨假丝酵母菌甘露聚糖抗原和假丝酵母菌IgG/IgM抗体、曲霉半乳甘露聚糖抗原和烟曲霉IgG抗体在侵袭性真菌病早期临床诊断中的应用价值。方法收集已确诊侵袭性假丝酵母菌病患者18例,侵袭性烟曲霉病患者6例,单纯细菌感染患者20例,浅部真菌感染患者20例,健康体检者(正常对照组)20例,通过酶联免疫吸附法(ELISA)检测患者血清甘露聚糖和假丝酵母菌IgG/IgM抗体以及曲霉半乳甘露聚糖抗原和烟曲霉IgG抗体浓度,计算各指标的灵敏度、特异度、阳性预测值、阴性预测值和受试者工作特征(ROC)曲线下面积。结果甘露聚糖抗原和假丝酵母菌IgG/IgM抗体联合测定的敏感度为66.7%,特异度为83.3%,阴性预测值为100.0%,阳性预测值为85.7%,ROC曲线下面积为0.992(95%CI:0.974~1.000);半乳甘露聚糖抗原和烟曲霉IgG抗体联合测定的敏感度为66.7%,特异度为95.0%,阴性预测值为98.2%,阳性预测值为100.0%,ROC曲线下面积为0.978(95%CI:0.934~1.000)。结论甘露聚糖抗原和假丝酵母菌IgG/IgM抗体、半乳甘露聚糖抗原和烟曲霉IgG抗体联合检测对深部真菌感染的早期诊断具有重要意义。     

The secretory response of hypothalamic β-endorphin neurons to acute and chronic nicotine treatments and following nicotine withdrawal

In the present study, we determined the effect of acute and chronic nicotine treatments on the secretion of immunoreactive β-endorphin (IR-β-EP) and cell viability of cultured hypothalamic neurons. Also, we determined the secretory response of IR-β-EP following withdrawal from a long-term nicotine treatment. Fetal hypothalamic cells were dissociated and maintained in cultures for 9 days and were treated with various doses of nicotine (1, 6,12 and 18 μM) for 6 h (acute treatment) or treated with nicotine at 12 h intervals for 96 h (chronic treatment). Determination of IR-β-EP concentrations in the media revealed that 6–18 μM doses of nicotine increased IR-β-EP secretion from these cultures for a period of 24 h; after this period, the cultured cells did not respond to these doses of nicotine. The desensitization of β-EP neurons 24 h after treatment with nicotine did not appear to be related to the loss of viable cells. Determination of withdrawal response after 72 h of constant nicotine (6 μM) treatments revealed that the hypothalamic neurons secrete elevated amounts of IR-β-EP for a period of 72 h after nicotine withdrawal. These results suggest that: 1) acute treatment with nicotine stimulates hypothalamic IR-β-EP release; 2) chronic nicotine treatment desensitizes β-EP-secreting neurons and, 3) β-EP neurons in primary culture show withdrawal response to nicotine.     

DHA status of vegetarians

The aim of the present study was to evaluate the influence of pregnancy in adolescents on the fatty acid composition of the erythrocyte membrane, which was used as a proxy for status of n-3 and n-6 polyunsaturated fatty acids (PUFA), and also on the composition of plasma non-esterified fatty acids (NEFA) mobilized from the adipose tissue. Two matched groups of healthy adolescents (14–19 years) from Rio de Janeiro, Brazil, were compared: pregnant (n=26; 32.7±3.9 weeks of gestation, mean±SD) and non-pregnant (n=20). Blood samples were collected after an overnight fast. Mean dietary intakes of total fat and n-3 and n-6 PUFA (energy %) were not different between pregnant and non-pregnant adolescents, and the consumption of food sources of docosahexaenoic acid (DHA) was low. Fasting total NEFA and NEFA 18:2n-6, 18:3n-6 and 20:4n-6 (g/100 g fatty acids) were higher in pregnant than in non-pregnant adolescents. Although erythrocyte 20:4n-6 was lower in pregnant adolescents, there were no differences in DHA (g/100 g fatty acids), in DHA status indices (22:5n-6/22:4n-6 and 22:6n-3/22:5n-6 ratios) and in the index of n-3+n-6 PUFA status ([Σn-3+Σn-6]/[Σn-7+Σn-9]) in erythrocytes as compared with those of non-pregnant adolescents. In conclusion, pregnancy did not have an adverse effect on erythrocyte DHA content or on DHA and n-3+n-6 PUFA status indices in the adolescents studied.     

Monoclonal antibodies raised against NeuAc alpha 2-6neolactotetraosylceramide detect carcinoma-associated gangliosides

Monoclonal antibodies wee obtained by the immunization of mice with 6'LM1 (IV6NeuAc-nLcOse4Cer) adsorbed to Salmonella minnesota. The monoclonal antibodies showed a specificity for gangliosides with a terminal NeuAc alpha 2-6Gal substitution, which was demonstrated in solid-phase binding assay and in liposome inhibition assay. Gangliosides with a NeuAc alpha 2-6Gal substitution were minor components of different normal tissues. However, these gangliosides were enriched in carcinomas of many tissues, and were particularly enriched in most colorectal carcinomas and in lung carcinomas. 6'LM1 is a characteristic ganglioside in fetal intestinal mucosa (meconium). This ganglioside and other gangliosides with a terminal NeuAc alpha 2-6Gal substitution might represent oncofetal antigens expressed in carcinomas owing to an activation of a "fetal' sialyltransferase.     

Human monoclonal antibodies derived from pleural effusion lymphocytes of a patient with breast carcinoma react with human breast cancer-associated antigens and mouse mammary tumor virus polypeptides

Four human hybridoma cell lines (PEB1-4) were established from a fusion of pleural effusion lymphocytes isolated from a breast cancer patient with metastatic disease, 6 years postmastectomy. The hybridomas secreted IgG-k (3 micrograms/ml/10(6) cells). These monoclonal antibodies (PEB1-4) reacted to different degrees with mouse mammary tumor virus (MMTV) and T47D particles (HuMTV). Immunological cross-reaction was also detected with antigens isolated from body fluids of breast cancer patients (BF-Ag). The binding capacity of the monoclonal antibodies (MAbs) PEB1-4 to the above-mentioned antigens was measured by RIA. The specificity of these antibodies was further demonstrated by radioimmunoprecipitation of MMTV, T47D (HuMTV) and BF-Ag. The binding of PEB1-4 to surface antigens of intact cells grown in culture was measured by RIA. Some of the MAbs were shown to bind more avidly to breast cancer cells than to nonbreast cancer cells or nonmalignant cells. The PEB1-4 human monoclonal antibodies may be found useful in analyzing the virus-breast cancer relationship.     

Nicotine regulates basic fibroblastic growth factor and transforming growth factor beta1 production in endothelial cells

Nicotine, a constituent of cigarette smoking, may induce atherosclerosis through the production of growth factors. The pattern of bFGF and TGF beta1 production and release by bovine aortic endothelial cells (EC) stimulated with nicotine (from 6 x 10(-4) to 6 x 10(-8) M) was studied. EC viability and count were assessed. The presence of bFGF and TGF beta1 in serum-free conditioned media was determined by the inhibition antibody-binding assay and Western blot analysis. Mitogenic activity of nicotine on EC was also determined. Polymerase chain reaction (PCR) was used to study the expression of bFGF and TGF beta1. The bFGF release after nicotine stimulation was greater than controls, whereas TGF beta1 release was lower. At a nicotine concentration of 6 x 10(-6) M we noted the greatest mitogenic activity. The addition of monoclonal antibody anti-bFGF decreased the tritiated thymidine uptake of EC exposed to nicotine but the addition of monoclonal antibody anti-TGF beta1 had no significant effect. bFGF mRNA expression was significantly higher in EC exposed to nicotine than in controls, whereas TGF beta1 mRNA expression was not modified. From these data we concluded that nicotine regulates bFGF production and release and TGF beta1 release and may have a key role in the development and progression of atherosclerosis.