Galectin-1 suppresses methamphetamine induced neuroinflammation in human brain microvascular endothelial cells: Neuroprotective role in maintaining blood brain barrier integrity

Methamphetamine (Meth) abuse can lead to the breakdown of the blood-brain barrier (BBB) integrity leading to compromised CNS function. The role of Galectins in the angiogenesis process in tumor-associated endothelial cells (EC) is well established; however no data are available on the expression of Galectins in normal human brain microvascular endothelial cells and their potential role in maintaining BBB integrity. We evaluated the basal gene/protein expression levels of Galectin-1, -3 and -9 in normal primary human brain microvascular endothelial cells (BMVEC) that constitute the BBB and examined whether Meth altered Galectin expression in these cells, and if Galectin-1 treatment impacted the integrity of an in-vitro BBB. Our results showed that BMVEC expressed significantly higher levels of Galectin-1 as compared to Galectin-3 and -9. Meth treatment increased Galectin-1 expression in BMVEC. Meth induced decrease in TJ proteins ZO-1, Claudin-3 and adhesion molecule ICAM-1 was reversed by Galectin-1. Our data suggests that Galectin-1 is involved in BBB remodeling and can increase levels of TJ proteins ZO-1 and Claudin-3 and adhesion molecule ICAM-1 which helps maintain BBB tightness thus playing a neuroprotective role. Galectin-1 is thus an important regulator of immune balance from neurodegeneration to neuroprotection, which makes it an important therapeutic agent/target in the treatment of drug addiction and other neurological conditions.

Isolation and characterization of nine microsatellite loci from Bemisia tabaci (Hemiptera: Aleyrodidae) biotype B

Nine microsatellites were isolated from Bemisia tabaci (Gennadius) biotype B and screened across 60 individuals from two populations (biotype B) to examine polymorphism. Two to 12 alleles were observed per locus. Observed and expected heterozygosities ranged from 0.033 to 0.967 and 0.033 to 0.854, respectively. There was no significant deviation from Hardy-Weinberg equilibrium and no significant linkage disequilibrium between loci. One locus showed evidence for null alleles. These loci will be useful in future studies of the genetic structure of worldwide biotypes and gene flow analyses between and within biotypes of B. tabaci.

Genomic and proteomic analysis of the effects of cannabinoids on normal human astrocytes

Delta-9-tetrahydrocannabinol (Delta(9)-THC), the main psychoactive component of marijuana, is known to dysregulate various immune responses. Cannabinoid (CB)-1 and -2 receptors are expressed mainly on cells of the central nervous system (CNS) and the immune system. The CNS is the primary target of cannabinoids and astrocytes are known to play a role in various immune responses. Thus we undertook this investigation to determine the global molecular effects of cannabinoids on normal human astrocytes (NHA) using genomic and proteomic analyses. NHA were treated with Delta(9)-THC and assayed using gene microarrays and two-dimensional (2D) difference gel electrophoresis (DIGE) coupled with mass spectrometry (MS) to elucidate their genomic and proteomic profiles respectively. Our results show that the expression of more than 20 translated protein gene products from NHA was differentially dysregulated by treatment with Delta(9)-THC compared to untreated, control NHA.

Association of drug abuse with inhibition of HIV-1 immune responses: studies with long-term of HIV-1 non-progressors

Recreational drug use has been proposed to affect the course of human immunodeficiency virus (HIV) infections. To investigate the effects of substance abuse on HIV infections, we compared virus-specific cytotoxic T lymphocyte (CTL) responses and the expression of IL-16, TGF-beta1, and CXCR4 in three different cohorts of HIV-infected patients: (1) long-term nonprogressors (LT-NPs) of HIV infection who do not use recreational drugs; (2) nondrugs using normal progressors (NPs), and (3) drugs using NPs. Our results show that LT-NPs manifest increased CTL activity and IL-16 expression and decreased expression of TGF-beta1 and CXCR4 compared to NPs, regardless of recreational drug usage. Furthermore, drugs using NPs showed significantly lower levels of CTL and IL-16 expression and increased TGF-beta1 and CXCR4 expression compared to nondrugs using NPs. Our results suggest that recreational drug use may reduce CTL and IL-16 expression and increase the expression of TGF-beta1 and CXCR4, all of which may facilitate progression of HIV infections.

Sensitization of human colon cancer cells to TRAIL-mediated apoptosis

TNF-related apoptosis-inducing ligand (TRAIL), a novel member of the tumor necrosis factor (TNF) family, is thought to induce apoptosis preferentially in cancer cells; however, increasing evidence suggests that a number of cancers are resistant to TRAIL treatment. FLICE-like inhibitory protein (FLIP), which structurally resembles caspase-8, can act as an inhibitor of apoptosis when expressed at high levels in certain cancer cells. The purpose of our present study was to determine whether human colon cancer cells are sensitive to TRAIL treatment and, if not, to identify potential mechanisms of resistance. Colon cancer cells of different metastatic potential (KM12C, KML4A, and KM20) were found to be resistant to the effects of TRAIL when used as a single agent. FLIP expression levels were increased in all three KM cell lines. Treatment with either actinomycin D (Act D;10 :g/ml) or cycloheximide (CHX; 10 :g/ml) decreased FLIP expression levels in all three cell lines. The decrease in cellular levels of FLIP was associated with sensitization to TRAIL-mediated apoptosis, as demonstrated by enhanced cell death and caspase-3 activity compared with either Act D or CHX alone. Our findings suggest that reduction of FLIP levels by Act D or CHX renders TRAIL-resistant human colon cancer cells sensitive to TRAIL-mediated apoptosis. The combination of TRAIL along with agents such as Act D or CHX, which target proteins that prevent cell death, may provide a more effective and less toxic regimen for treatment of resistant colon cancers.

Intravenous immunoglobulin treatment of immunodeficiency disorders

ADDs can occur as primary genetic disorders or may develop secondary to various other conditions, including infections, trauma, malnutrition, and protein-losing states. Although antibiotics are the first-line therapy for acute infection, using them prophylactically can select for resistant organisms. IM ISG and fresh frozen plasma were the principal agents for antibody-replacement therapy until the advent of IVIG 2 decades ago. IVIG is now the definitive product for antibody-replacement therapy. Although IVIG has a long history of safety regarding the infectious pathogens, the identification of more than 100 patients with non-A, non-B hepatitis apparently acquired from a single product prompted additional modifications, improving the safety profile of IVIG. Despite the excellent safety record of IVIG, the unexpected occurrence of hepatitis in some recipients served as a reminder that IVIG is a biologic product derived from human plasma. Newer products are being developed that may supplement polyvalent IVIG including humanized MAbs and hyperimmune IVIG preparations to address specific clinical requirements.

The stress hormone, cortisol, synergizes with HIV-1 gp-120 to induce apoptosis of normal human peripheral blood mononuclear cells

Both quantitative and qualitative defects in immune functions in patients with AIDS may result from induction of programmed cell death or apoptosis of CD4 T lymphocytes. We postulate that neurohormones may interact with gp-120 that is shed during active HIV infection and cause apoptosis of immunocompetent cells leading to immunopathogenesis of HIV infections. In this study, we investigated the synergistic effect of cortisol plus HIV gp-120 in inducing apoptosis of lymphocytes from normal subjects. Total peripheral blood mononuclear cells and isolated CD4+ T-cells were treated with cortisol or gp-120 separately and in combination and RNA and DNA were extracted. RNA was reverse transcribed and amplified with specific primers for Fas and Fas ligand and analyzed on agarose gels. DNA was analyzed by gel electrophoresis for ladder formation, the hallmark for apoptosis, and Fas antigen expression by confocal microscopy. Results demonstrate that cortisol and gp-120 induce apoptosis of lymphocytes from normal donors as demonstrated by DNA ladder formation, TUNEL staining and Fas gene expression. Concentrations of cortisol and gp-120 that did not produce apoptosis when used separately, induced significant apoptosis when used in combination. Further, gp-120 induced DNA fragmentation was significant in the CD4+ T-cell subpopulation compared to the CD47 subpopulation. This study suggests that the stress-associated neurohormone, cortisol, synergizes with HIV peptides in causing apoptosis of normal lymphocytes. The synergistic effect of cortisol and gp- 120 in inducing apoptosis of lymphocytes is consistent with a model proposing that stress-associated and circulating HIV-1 derived soluble products may cause progression of HIV infections.

Cocaine differentially modulates chemokine production by mononuclear cells from normal donors and human immunodeficiency virus type 1-infected patients

Earlier studies have supported a significant role for cocaine in the susceptibility to and the progression of human immunodeficiency virus type 1 (HIV-1) infection. Recently, several unique HIV-1 entry coreceptors (e.g., CCR5 and CCR3) and a trio of HIV-1-specific suppressor chemokines, namely, RANTES (regulated-upon-activation T expressed and secreted), macrophage inflammatory protein 1alpha (MIP-1alpha) and MIP-1beta, were identified. Although cocaine has been linked to the immunopathogenesis of HIV-1 infection, the corresponding cellular and molecular mechanism(s) have not been well defined. We hypothesize that cocaine mediates these pathologic effects through the downregulation of HIV-1-suppressing chemokines and/or upregulating HIV-1 entry coreceptors in HIV-1-infected subjects, resulting in disease progression to AIDS. Our results show that cocaine selectively downregulates endogenous MIP-1beta secretion by normal peripheral blood mononuclear cells (PBMC), while cocaine did not affect the MIP-1beta production by PBMC from AIDS patients. Cocaine also selectively suppresses lipopolysaccharide-induced MIP-1beta production by PBMC from HIV-infected patients. Further, cocaine significantly downregulates endogenous MIP-1beta gene expression, while it upregulates HIV-1 entry coreceptor CCR5 by normal PBMC. These studies suggests a role for cocaine as a cofactor in the pathogenesis of HIV infection and support the premise that cocaine increases susceptibility to and progression of HIV-1 infection by inhibiting the synthesis of HIV-1 protective chemokines and/or upregulating the HIV-1 entry coreceptor, CCR5.

Reversal of human immunodeficiency virus type 1 protein-induced inhibition of natural killer cell activity by alpha interferon and interleukin-2

A recombinant fusion peptide, Env-Gag, derived from the human immunodeficiency virus type 1 (HIV-1) genome corresponding to a defined portion of the envelope (Env) and internal core (Gag) proteins was examined for immunoregulatory effects on the cytotoxic activity of natural killer (NK) cell-enriched, large granular lymphocytes (LGL) from healthy donors. Percoll-separated, NK cell-enriched LGL precultured for 24 h with Env-Gag at 10- and 50-ng/ml concentrations, which significantly stimulated lymphocyte proliferation, caused significant suppression of NK cell activity. Denatured Env-Gag did not cause any effect on the NK cell activity of LGL. Two other control peptides, one derived from the Escherichia coli vector used to clone the HIV Env-Gag fusion peptide and the other derived from a non-HIV-1 viral antigen (rubeola virus), did not produce any observable effect on the NK cell activity of LGL, demonstrating the specificity of the effect produced by Env-Gag. Subsequent treatment of LGL with alpha interferon (IFN-alpha) or interleukin 2 (IL-2) alone partially reversed the Env-Gag-induced suppression of NK cell activity. However, LGL treated with both IFN-alpha and IL-2 completely reversed the suppression of NK cell cytotoxicity by Env-Gag. The combined effect of IFN-alpha and IL-2 in enhancing NK cell activity may provide a novel therapeutic approach to the restoration of depressed NK cell activity observed in HIV-infected patients.

The role of NF-kappaB/IkappaB proteins in cancer: implications for novel treatment strategies

The nuclear factor-kappaB (NF-kappaB) family of transcription factors are involved in multiple cellular processes, including cytokine gene expression, cellular adhesion, cell cycle activation, apoptosis and oncogenesis. Constitutive activation of NF-kappaB has been described in a number of solid tumors and this activation appears to affect cancer cell survival. Inhibition of NF-kappaB has been shown to enhance the sensitivity of some cancer cell lines to antineoplastic- or radiation-induced apoptosis. Furthermore, suppression of NF-kappaB results in attenuation of cancer cachexia in a mouse tumor model. Studies are underway to further delineate the role of NF-kappaB in cancer cell survival, growth and resistance to standard chemotherapy and radiation regimens. Moreover, the effects of novel therapeutic agents which specifically target NF-kappaB proteins are currently being assessed in experimental models of cancer cell growth both in vitro and in vivo. In this review, we discuss the possible involvement of NF-kappaB in the growth of various solid tumors and potential future treatment strategies based on NF-kappaB inhibition.

Molecular mechanisms in the pathogenesis of AIDS encephalopathy

While progress has been made in our knowledge of the natural history of HIV infections, an understanding of the molecular pathogenesis of AIDS encephalopathy remains to be determined. Previously we demonstrated that apoptosis and a deficiency of natural killer (NK) cell activity may play significant roles in the progression of HIV infections. We also reported that intracerebral co-injection of a recombinant HIV-1 fusion protein plus an excitatory amino acid agonist into neonatal rats synergistically produced brain pathology. Here we examine: 1) the effects of the HIV-1 envelope protein, gp-120, on neonatal rat astrocytes in vitro; 2) the spontaneous apoptosis of human neonatal and adult mononuclear leukocytes and, 3) the selective inhibition of NK activity cell from adult AIDS patients by the HIV-1 protein that caused brain pathology in neonatal rats. We demonstrate that gp-120 suppresses fas gene expression, a marker for apoptosis, by neonatal rat astrocytes. Neonatal human mononuclear leukocytes manifest spontaneous apoptosis as measured by DNA ladder formation while cells from adult donors do not. Direct addition of the HIV-1 protein to mononuclear cells in vitro selectively suppressed the NK cell activity from AIDS patients. These results support our premise that HIV-1 proteins are involved in the pathogenesis of AIDS encephalopathy.

Inhibition of natural killer cell activities from normal donors and AIDS patients by envelope peptides from human immunodeficiency virus type I

Recombinant and synthetic peptides derived from the human immunodeficiency virus type I (HIV-1) genome corresponding to portions of the envelope (env) and internal core protein (gag) were examined for their immunoregulatory effects on the natural killer (NK) cell activity of lymphocytes from healthy donors and from patients with the acquired immunodeficiency syndrome (AIDS). Two recombinant peptides (env-gag and Env 80-DHFR) and three chemically synthesized peptides (env 487-511, env 578-608 and env 647-659) were used. Normal lymphocytes precultured for 24 to 72 hrs. with either env-gag, env 487-511, or env 647-659 at 5 and 50 ng/ml concentrations which significantly stimulated lymphocyte proliferation, produced significant suppression of NK activities. Two control peptides, one derived from the E. coli vector used to clone the HIV env-gag fusion peptide and another, a non-HIV-1 viral antigen (rubeola virus) did not produce any observable effect on NK activity of normal lymphocytes demonstrating the specificity of the reaction. Env-gag peptide also inhibited the NK activities of Percoll-separated, NK-enriched large granular lymphocytes. In target binding assays, lymphocytes precultured with env-gag significantly suppressed the target binding capacity of effector cells and produced significantly lower levels of natural killer cytotoxic factor (NKCF). In kinetic studies, lymphocytes from normal donors preincubated with env-gag for 24 to 72 hrs. produced significant inhibition of their NK activity and an even greater inhibitory effect on NK activities was observed when lymphocytes from AIDS patients were preincubated with HIV peptides. Thus HIV-1 peptides, which we previously demonstrated could regulate B- and T-lymphocyte activities, are also capable of regulating the NK activities of lymphocytes from HIV-1-infected and normal individuals.

An RGD containing peptide from HIV-1 Tat-(65-80) modulates protooncogene expression in human bronchoalveolar carcinoma cell line, A549

Tat (transactivator of transcription) is essential for HIV-1 replication in vivo and in vitro. Tat-(65-80), an RGD containing domain, has been shown to regulate proliferative function of a variety of cell lines, including a human adenocarcinoma cell line, A549. The exact cellular and molecular mechanisms by which these effects are mediated, remain unknown. To evaluate the hypothesis that Tat-(65-80) modulates the expression of immediate early genes (IEG) c-jun, c-myc, c-fos and the tumor suppressor gene p53, serum starved A549 cells were incubated with Tat-(65-80) or heat-inactivated Tat-(65-80) at 10 ng/ml. Total cellular RNA was isolated from the cells at various time points (0-24 hours). In each case, 5 micrograms of RNA was reverse transcribed in 20 microliters of reaction volume. Equal amounts of cDNA were subjected to polymerase chain reaction (PCR) and analyzed by electrophoresis. The photographic negatives of the ethidium bromide stained gels were quantitated by densitometric scanning and normalized to corresponding beta-actin PCR products. Treatment with Tat-(65-80) showed a twofold induction of c-jun at 0.5 h. Peak expression occurred at 60 minutes and remained above baseline at 24 hours (h). c-myc was increased at 0.5 h, reached a twofold increase at 2 h and remained above baseline at 24 h. c-fos increased seven fold at 0.5 h and declined subsequently to baseline at 8 h. p-53 gene was reduced fivefold at 0.5 h and remained downregulated thereafter. These results show that Tat-(65-80) can modulate growth related genes in human lung epithelial cells.

Immunoregulatory effects of morphine on human lymphocytes

It is now well established that parenteral drug abuse is a significant risk factor for contracting human immunodeficiency virus type 1 (HIV-1) infection and subsequently developing AIDS. Earlier studies have shown that morphine can modulate various immune responses and therefore support the premise that morphine is a cofactor in susceptibility to and progression of HIV infection. Dysregulation of interferon (IFN) production, nonspecific apoptosis of T cells, and the immune response to soluble HIV gene products have been associated with potential mechanisms of pathogenesis in HIV disease. The present study was undertaken to examine the immunomodulatory role of morphine on HIV protein-induced lymphocyte proliferative responses, Sendai and Newcastle disease virus-induced alpha IFN (IFN-alpha) and IFN-beta production by lymphocytes and fibroblast cells, respectively, and induction of apoptosis of normal lymphocytes in vitro. Our results demonstrate that HIV protein-induced human lymphocyte proliferative responses were significantly inhibited by morphine in a dose-dependent manner. Furthermore, morphine significantly inhibited both IFN-alpha and IFN-beta production by normal lymphocytes and fibroblasts but induced apoptosis of normal lymphocytes. Inhibition of IFN-alpha production by morphine could be reversed by the opiate receptor antagonist naloxone. This suggests that the immunomodulatory effects of morphine are mediated through the opioid receptor. These studies support a role of morphine as a cofactor in the pathogenesis of HIV infection and describe some of the possible pathologic mechanisms which underlie the immunoregulatory effects of morphine.

Management of a maxillary canine with dens invaginatus and a vital pulp

A case is presented that demonstrates successful management of a maxillary canine with dens invaginatus (Oehlers' type 3 invagination) with associated chronic periradicular periodontitis and a vital pulp. Debridement and obturation of the invaginated space resulted in resolution of the associated periradicular radiolucency. Pulp vitality was retained after endodontic treatment of the invagination.

Alcohol inhibits lipopolysaccharide-induced tumor necrosis factor alpha gene expression by peripheral blood mononuclear cells as measured by reverse transcriptase PCR in situ hybridization

We recently showed that alcohol significantly suppressed lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNF-alpha) production by whole blood and total mononuclear cells from healthy subjects as measured by bioassay. In the current study, we further examined the effect of alcohol on LPS-induced TNF-alpha gene expression by semiquantitative solution PCR and in situ reverse transcriptase PCR (RT-PCR) hybridization methods. Peripheral blood mononuclear cells were cultured with LPS (10 micrograms/ml) for 4 to 8 h with or without different concentrations of ethanol (0.1, 0.2, and 0.3% [vol/vol]). Total RNA from treated and untreated cultures was extracted and used for solution PCR analysis. Treated and untreated cells were subjected to both conventional in situ hybridization and RT-PCR in situ hybridization. In solution RT-PCR in vitro analysis, alcohol significantly suppressed TNF-specific message. In conventional in situ hybridization, the effect of alcohol on TNF-alpha gene expression was poorly detected. However, when cells were subjected to RT-PCR prior to in situ hybridization, cells treated with alcohol significantly suppressed expression of the message for TNF-alpha. These studies confirm our earlier finding that alcohol suppressed the production of TNF-alpha by LPS-induced whole blood cells and peripheral blood mononuclear cells. Furthermore, these studies also demonstrate that the RT-PCR in situ technique is a powerful tool for detecting and amplifying specific genes in whole cells when limited numbers of cells are available for RNA extraction.

Substance P induces tumor necrosis factor in an ex vivo model system

Many studies have shown that tumor necrosis factor (TNF) is a potent soluble mediator of immunoregulation and inflammation. Neuropeptide substance P (SP) has been known to exert significant influence on production of certain inflammatory cytokine by immune cells. Immunopathogenic mechanism underlying the effect of neuropeptide substance P (SP) and the specific amino acid sequence of SP that induces TNF has not been clearly studied. Employing ex vivo and in vitro model systems, we investigated the direct effect of different sequences of SP on TNF secretion by whole blood and separated total mononuclear cells. Aliquots of blood samples (1 ml) or Ficoll-Hypaque-separated total mononuclear cells (1 x 10(6)/ml) were cultured with different concentrations of SP and its sequences (SP 1-4, SP 4-11) or vasoactive intestinal peptide (VIP) for 24 hr at 37 degrees C. Plasma samples and culture supernatants were assayed for TNF levels in a bioassay using a TNF-sensitive WEHI 164 subclone 13 cell line. Plasma from blood samples or lymphocytes treated with whole SP and SP 4-11 at 10(-7), 10(-8), and 10(-9) M concentrations induced significant production of TNF compared to negligible levels of TNF produced by SP 1-4-treated and untreated cultures. VIP at all concentrations tested did not induce TNF production and was similar to untreated control cultures. Separated mononuclear cells also produced significant levels of TNF in response to SP and SP 4-11. Anti-TNF-alpha antibodies neutralized the TNF induced by SP 4-11 in plasma. These studies suggest that an ex vivo system using whole blood may be an ideal model to study the effects of SP on TNF production. These studies also demonstrated that the TNF inducing activity of SP residues in the region containing amino acids 4 to 11.

Biotinylated probes in the electrophoretic mobility shift assay to examine specific dsDNA, ssDNA or RNA-protein interactions

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Selective inhibitory effects of stress hormones on natural killer (NK) cell activity of lymphocytes from AIDS patients

To examine the potential role of stress hormones in the progression of HIV infections, we developed an in vitro model system that investigates the effects of cortisol, adrenocorticotropin-releasing hormone (ACTH) and beta-endorphin on the natural killer cell activity of lymphocytes from normal subjects and AIDS patients. The system employs a 4 hr 51Cr release assay and K562 target cells. Direct addition of cortisol (0.05, 0.1, and 0.2 microgram/ml) or ACTH (10(-6) to 10(-8) M) to the mixture of effector and prelabeled target cells did not produce any significant immunoregulatory effects on the NK cell activity of normal lymphocytes. Direct addition of beta-endorphin (10(-13) to 10(-17) M) to the mixture of effector and prelabeled target cells did not produce any significant immunoregulatory effects on the NK cell activity of lymphocytes from normal or AIDS subjects. However, cortisol and ACTH significantly inhibited the NK activity of lymphocytes from AIDS patients. The selective inhibitory effects of cortisol and ACTH in patients with HIV infections are consistent with a model which proposes that stress related neurohormones and/or neuropeptides may be involved in the progression of HIV infections.

Differential effects of human immunodeficiency virus type 1 envelope protein gp120 on interferon production by mononuclear cells from adults and neonates

While considerable progress in examining the course of human immunodeficiency virus (HIV) infection in adults has been made, a better understanding of the natural history of perinatal HIV infection remains to be obtained. Dysregulation of the production and functions of various cytokines, especially the interferons (IFNs), during HIV infections has been reported. Using an in vitro model system, we examined the effects of the HIV type 1 envelope protein, gp120 (10, 50, and 100 ng/ml), on gamma IFN (IFN-gamma) and IFN-alpha production by lymphocytes from neonates and adults and also examined the potential regulatory effects of gp120 on phorbol 12-myristate acetate (PMA)- and Sendai virus-induced IFN-gamma and IFN-alpha production by lymphocytes. PMA at a concentration of 50 ng/ml plus 50 ng of calcium ionophore A23187 per ml was used to induce IFN-gamma, while 150 hemagglutinating units of Sendai virus was used to induce IFN-alpha production. The antiviral activity of both IFN-alpha and IFN-gamma in leukocyte culture supernatants was assayed on BG-9 cells by a dye uptake technique using vesicular stomatitis virus as a challenge virus. Placental cord blood leukocyte (CBL) samples from healthy, term infants and adult peripheral blood leukocytes (APBL) produced no IFN in response to gp120. However, CBL produced significantly decreased levels of IFN-gamma compared with APBL in response to PMA plus ionophore. gp120 significantly suppressed both Sendai virus-induced IFN-alpha and PMA-induced IFN-gamma production by both CBL and APBL in a dose-dependent manner. However, gp120-induced suppression of IFN-alpha and IFN-gamma was significantly greater with CBL than with APBL. Treatment of CBL and APBL with gp120 did not induce any phenotypic alteration of the CD45 RO+ subset. Increased suppression of IFN-alpha and IFN-gamma production by gp120 in neonates may partially explain their apparent increased susceptibility to the clinical progression of HIV infections compared with that of adults.

Synergistic effect of cortisol and HIV-1 envelope peptide on the NK activities of normal lymphocytes

In order to examine the potential role of stress hormones and circulating HIV-1-derived products in the progression of HIV infections, we developed an in vitro model system that investigates the effects of cortisol and HIV soluble gene products on the natural killer cell activity of normal lymphocytes. The system employs a 4-h 51Cr release assay and K562- and LAV-infected 8E5/LAV target cells. Direct addition of cortisol at 0.05, 0.1, and 0.2 microgram/ml or the HIV recombinant peptide, env-gag, at 1, 10, and 50 ng/ml separately to the mixture of effector and prelabeled target cells did not produce any significant immunoregulatory effects on NK cell activity against either target. However, cortisol or env-gag at concentrations that did not produce any inhibitory effect on NK activity when used separately, manifested significant inhibitory effects when added in combination. Suppression was evident at concentrations as low as 1 ng/ml of env-gag and 0.05 microgram/ml of cortisol and was observed at different effector:target cell ratios. Suppression was not caused by nonspecific toxicity of cortisol or HIV peptides when added in combination to the effector cells nor was due to decreased susceptibility of targets to lysis by effector cells. A non-HIV viral antigen (Rubeola virus) and another HIV-1 envelope-derived sequence (env 578-608 aa) were used as controls separately or in combination with cortisol and did not produce significant inhibition thus demonstrating the specificity of env-gag-induced inhibition. The synergistic inhibitory effect of cortisol- and HIV-derived soluble products in patients with HIV infections are consistent with a model that proposes that stress and circulating HIV-1-derived products may be involved in the progression of HIV infections.

MEDLINE training for medical students integrated into the clinical curriculum

This study was initiated in response to the availabilty of unlimited access to MEDLINE via the PaperChase interface at the host institution. The goal of the study was to analyse the usage of MEDLINE by medical students during their third-year clinical clerkship in paediatrics. This was achieved by first giving them a formal demonstration of MEDLINE and then longitudinally administering a structured questionnaire at several points during their paediatric clerkship. Since medical students were required to write a thesis for this clerkship, which included an analysis of the primary literature, there was an identified need for using the system. This study analyses the students' perceptions and searching activities after formal training and upon having unlimited access to MEDLINE.

Selective inhibition by alcohol and cortisol of natural killer cell activity of lymphocytes from cord blood

1. The immunosuppressive effects of drugs such as alcohol or hormones such as cortisol may be age-related. To test this hypothesis, the authors investigated the in vitro effects of ethanol (EtOH) and cortisol on Natural Killer (NK) cell activity of lymphocytes from normal cord blood in comparison with that of lymphocytes from normal adult peripheral blood. 2. K562, an erythroleukemia cell line, was used as a target in a 4 hr 51Cr release assay. 3. Ethanol at 0.3% (V/V) and cortisol at 0.05, 0.1 and 0.2 microgram/ml concentrations, added directly to a mixture of effector and target cells significantly suppressed the NK activity of cord blood lymphocytes in a dose dependent fashion, whereas similar concentrations of either EtOH or cortisol did not manifest significant immunoregulatory effects on NK cell activity of normal adult lymphocytes. 4. Pre-treatment of the target with either EtOH or cortisol for 4 hours did not affect cytotoxicity. Inhibition of cytotoxicity was also not due to direct toxicity of effector cells because lymphocytes treated with either EtOH or cortisol showed normal 51Cr release and their viability was comparable to that of untreated control cells. 5. This suggests a selective inhibitory effect of EtOH and cortisol on NK activity of neonatal lymphocytes that may be of clinical significance.

Depressed natural killer cell activity in schizophrenic patients

Factors that suppress natural killer (NK) cell activity were examined in a random sample of 73 schizophrenic patients. NK activity in these patients were compared with 25 healthy age, sex and race matched controls. The mean percent of NK activity was 21% in the schizophrenic group compared with 30% percent in the controls. The difference between these two groups was statistically significant. The mean percent of NK activity in the chronic undifferentiated schizophrenic subgroup and schizoaffective subgroup were 20% and 22% respectively. The degree of suppression of NK activity in the chronic undifferentiated subgroup was higher than in the schizoaffective one, but the difference was not statistically significant. The two subgroups were comparable regarding other immune related variables such as total white cell count, neutrophils, lymphocytes, total protein, albumin, globulin, immunoglobulins and stress. The lower impairment of NK activity in the schizoaffective subgroup may be due to their exposure to lithium which can enhance immune functions. Factors associated with significant suppression of NK activity in schizophrenic patients were physical restraint, number of psychotropic medications, number of chronic non-psychiatric diagnoses and race. Psychosocial stressors were associated with suppression of NK activity but it was not statistically significant. Our results identify factors associated with reduced NK activity observed in certain schizophrenic patients and NK activity in these patients may be the result of interaction between various factors.

Suppression of tumor necrosis factor production by alcohol in lipopolysaccharide-stimulated culture

Many studies have shown that alcohol consumption is associated with alteration in immune responses and increased incidence of infection in the host. Tumor necrosis factor (TNF) is a potent soluble mediator of immunoregulation and inflammation, and plays a very important role in host's defenses against infection and tumor. We propose that one of the mechanisms of alcohol-mediated immunosuppression may be due to a defect in the synthesis and release of the TNF. To determine this, we studied the direct effect of alcohol on lipopolysaccharide (LPS)-induced TNF production by whole blood and total mononuclear cell from normal subjects. Aliquots of blood samples (1 ml) or ficoll-hypaque separated total mononuclear cells (1 x 10(6)/ml) were cultured with different concentrations of either ethanol or acetaldehyde in the presence or absence of LPS for 4 hr at 37 degrees C. Plasma samples and culture supernatants were assayed for TNF levels in a bioassay using a TNF-sensitive WEHI 164 subclone 13 cell line. LPS at 10 micrograms/ml produced a maximal level of TNF compared with lower (1 micrograms/ml) or higher concentration (50 micrograms/ml) of LPS. Kinetics studies showed that an incubation time of 4 hr with LPS produced a maximum level of TNF production by blood. Alcohol, as low as 0.1% concentration, produced significant suppression of LPS-induced TNF production by whole blood, whereas alcohol at 0.2 and 0.3% concentrations were required to produce a significant suppression of TNF production by separated mononuclear cells. Anti-TNF-alpha antibodies significantly neutralized the LPS-induced TNF that suggests that blood monocytes may be the primary source of TNF production.(ABSTRACT TRUNCATED AT 250 WORDS)

Levamisole as an immunopotentiator for T cell deficiency

Levamisole, a widely used antihelminthic drug has been shown to restore cutaneous delayed hypersensitivity in anergic patients with cancer and to amplify the activation of T lymphocytes by in vitro mitogens. Levamisole has been approved for the treatment of colon cancer in combination with 5 Fluorouracil. Herein we report a case of a 5 1/2 y.o. male who presented with a fulminant, disseminated mycobacterial infection of his joints secondary to a deficiency in his cellular mediated immunity in association with chemotherapy for a T cell leukemia. The patient was treated with Levamisole resulting in restoration of his T cell functions and resolution of his mycobacterial infection.

Selective effect of alcohol on cellular immune responses of lymphocytes from AIDS patients

In this study we examined the in vitro effects of alcohol on the proliferative responses of lymphocytes from healthy donors and AIDS patients to a recombinant fusion peptide, env-gag, corresponding to portions of the gp41 envelope (env) and internal core (gag) proteins of HIV. The effects of alcohol (ETOH) on the natural killer (NK) cell activities of lymphocytes from healthy donors and patients with AIDS were also investigated. Peripheral blood mononuclear cells from both normal donors and AIDS patients produced significant levels of lymphocyte proliferative responses to the HIV env-gag peptide; however, these responses were significantly higher in patients with AIDS, showing the specificity of the response. The env-gag-induced proliferative responses of lymphocytes from normal subjects were significantly suppressed when cultures contained only higher levels of ETOH (0.2% and 0.3%), whereas ETOH even at a lower level (0.1%) produced significant suppression of the env-gag-induced proliferation of lymphocytes only from AIDS patients. Direct addition of ETOH at concentrations of 0.1%, 0.2%, and 0.3% to cultures of lymphocytes from normal donors and NK target cells did not produce significant suppression of NK cell activities. However, ETOH at concentrations of 0.2% and 0.3% significantly suppressed the NK activities of lymphocytes from AIDS patients, and the suppressive effect was observed at all E:T cell ratios examined. Control peptide from the Escherichia coli expression vector did not produce any significant effect on lymphocyte proliferative responses or NK activity of both normal donors and AIDS patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Human monoclonal lambda light chain protein exhibits specific binding to the variable region of monoclonal anti-IgE antibody

A monoclonal heterohybridoma cell line (B11-12) was developed by fusing EBV-transformed lymphocytes from a patient with hyper-IgE syndrome and SHM-D33 heteromyeloma cells. The resultant heterohybridoma secreted only human lambda L chains exhibiting specific binding to mouse monoclonal Ab to human IgE (mAb-algE). B11-12 bound to four separate mAb-algE, but not to mAb of the same isotypes directed to other antigens. The mAb-algE differed in isotype (IgG1; IgG2b) demonstrating that B11-12 was recognizing an idiotypic, but not an isotypic determinant on the mAb-algE. Human IgE did not inhibit B11-12 binding to mAb-algE, suggesting the interaction between B11-12 and mAb-algE involved an idiotope outside the combining site of the mAb-algE. Human sera, including serum from the donor of the lymphocytes used to produce heterohybridoma B11-12, demonstrated the capacity to inhibit B11-12 binding to mAb-algE. This, along with the inability of these same sera to directly bind B11-12, suggests that the serum contained reactivity similar to B11-12. We propose that B11-12 demonstrates specificity resembling an anti-Id to anti-human IgE Ab.

Arrest of amelogenin transcriptional activation in bromodeoxyuridine-treated developing mouse molars in vitro

An important issue in craniofacial biology is understanding the molecular mechanisms that regulate the transcription of genes during development. Low concentrations of the thymidine analogue, 5-bromodeoxyuridine (BrdU), have been used to perturb transcription of tissue-specific genes in a variety of tissue types, although the molecular mechanism for this inhibition has not been elucidated. The purpose of the present study was to examine the following: (1) if amelogenin transcription is inhibited in mouse molars cultured in the presence of BrdU, (2) if changes in methylation patterns of the amelogenin gene can be detected with terminal differentiation of ameloblasts in vivo and in vitro; and (3) if changes in methylation patterns of the amelogenin gene can be detected in mouse molars cultured in the presence of BrdU. Northern blot hybridization and RNA phenotyping analysis revealed that bromodeoxyuridine (BrdU) incorporation into the DNA of developing mouse mandibular first molars (M1) in vitro inhibited amelogenin transcription. Restriction endonuclease digestion of M1 genomic DNA followed by Southern blot hybridization analysis revealed that amelogenin transcriptional activity in vivo and in vitro did not correlate with changes in methylation of the amelogenin gene. These results suggested that, unlike several other developmentally regulated genes, transcriptional regulation of the amelogenin gene may not be associated with changes in DNA methylation patterns.

Potentiation of N-methyl-D-aspartate-mediated brain injury by a human immunodeficiency virus-1-derived peptide in perinatal rodents

In this study, we tested the hypothesis that human immunodeficiency virus (HIV)-1-derived peptides augment the neurotoxicity of excitatory amino acid agonists in vivo in postnatal day (PND) 7 rats. Stereotaxic intracerebral injections of the excitatory amino acid agonist N-methyl-D-aspartate (NMDA), alone or coinjected with an HIV-derived recombinant fusion peptide envelope gag (env-gag) were performed in PND-7 rats [group I: 5 nmol NMDA, n = 20; group II: 5 nmol NMDA + low-dose (1 or 50 ng) env-gag, n = 27; group III: 5 nmol NMDA + high-dose (100 ng) env-gag, n = 20], and brain injury was evaluated on PND 12. Based on histopathology scoring and measurements of hippocampal cross-sectional areas in the injected and contralateral hemispheres, coinjection of 100 ng of env-gag with 5 nmol of NMDA markedly increased the severity of resulting injury (p < 0.002, comparing histopathology scores; p < 0.003, comparing interhemispheric differences in hippocampal areas). These data suggest that in the developing nervous system HIV neurotoxicity may result, at least in part, from overactivation of excitatory amino acid receptors, and that perinatal rodent models may provide clinically relevant insights about the pathophysiology of HIV-mediated brain injury.

Effect of neuropeptide Y on natural killer activity of normal human lymphocytes

The in vitro effect of neuropeptide Y (NPY) on natural killer (NK) cell activities of normal lymphocytes was investigated. NPY at 10(-9) to 10(-12) M concentrations produced significant suppression of NK activity against K 562 target cells. NPY at 10(-9) to 10(-12) M concentrations also produced significant inhibitory effects on NK activities of NK-enriched large granular lymphocytes against LAV-infected 8E5/LAV target cells. The suppression was dose dependent against both targets. NPY-induced suppression of NK activity of lymphocytes against K 562 target cells was specifically reversed by rabbit anti-NPY antisera at 1:800 and 1:1600 dilutions, showing the specificity of reactions. Pretreatment of target cells with NPY concentrations capable of inhibiting NK activity did not affect the sensitivity of K 562 target cells for lysis by effector cells. Inhibition of cytotoxicity was not due to direct toxicity of effector cells, because lymphocytes treated with NPY showed normal levels of 51Cr release and their viability was comparable to that of untreated control cells. These studies demonstrated that NPY, a product of sympathetic nervous system activation, may have a significant immunoregulatory effect on NK cell activities of normal lymphocytes that may be of clinical significance.

Recovery of infectious HIV-1 from whole saliva

Whole saliva and serum samples were collected from 75 HIV-infected homosexual or bisexual men. Thirty-eight percent of cultured sera were positive for cell-free, infectious virus while only 1 percent of the 218 cultured whole salivas contained cell-free, infectious virus. These data support previous studies suggesting unlikely potential transmissibility of HIV infection by saliva.

Clinical use of immune serum globulin as replacement therapy in patients with primary immunodeficiency syndromes

IVIG is the definitive therapy for primary immunodeficiency diseases associated with hypogammaglobulinemia or specific antibody deficiencies. Administration of IVIG is relatively safe, but occasional adverse reactions are usually self-limited and generally are not an indication for stopping therapy. Home administration of IVIG has found increasing favor among treating physicians and their patients.

Modulation of a human immunosuppressive lymphokine by monosaccharides

Soluble suppressor factor (SSF) is a recently purified human lymphokine produced by peripheral blood lymphocytes (PBL) in serum-free medium as a likely consequence of an autologous mixed lymphocyte reaction. Immunoregulatory actions of SSF include suppression of: polyclonal B cell activation, proliferative responses of normal PBL, and natural killer (NK) and antibody-dependent cellular cytotoxicity. We examined the ability of the monosaccharides fucose (Fuc), galactose (Gal), glucose (Glc), and mannose (Man) to reverse SSF-mediated suppression of NK activity. Fuc and Gal can partially or completely reverse SSF-mediated suppression at four effector:target cell ratios. Man and Glc were unable to significantly reverse SSF-mediated suppression. Fuc or Gal was added to PBL at various times after addition of SSF. SSF-mediated suppression of NK cytotoxicity becomes irreversible with respect to these monosaccharides during the first 24 hr of PBL exposure to SSF. To explore the mechanism behind this block of SSF-mediated suppression. Fuc or Gal (50 mM) was cultured with PBL for 24 hr before addition of SSF, or with SSF for 24 hr before addition to PBL. Our experiments indicate that SSF is directly interacting with these monosaccharides, and may function by recognizing specific sugar moieties on the surface of effector cells.

Relapse in sexual behavior among homosexual men: a 2-year follow-up from the Chicago MACS/CCS

Serial biannual cross-sectional assessments of HIV sexual risk indicated a consistent increase in safer sexual practices among homosexual men participating in the Chicago-Multicenter AIDS Cohort Study (MACS)/Coping and Change Study (CCS) in 1986-1988. Safer sexual practices were achieved by avoidance of anal sex and less often by consistent use of condoms. Longitudinal patterns of variability in individual behavior were also assessed. After 1 year of follow-up, 53% of the participants maintained safer practices in receptive anal sex, 6% maintained unsafe practices, while 31% relapsed at least once. After 2 years, 45% maintained safer practices, 3% maintained unsafe practices and 47% relapsed at least once. Similar trends were observed in insertive anal sex.

Immunoregulation of natural and lymphokine-activated killer cells by selenium

The effect of selenium (Se) on natural killer (NK) and lymphokine-activated killer (LAK) cell activities and proliferative responses of human lymphocytes was studied in vitro. Direct addition of Se at 1.0 microgram/ml final concentration to the mixture of target and effector cells during a 4 h cytotoxicity assay significantly suppressed the NK activity of normal lymphocytes. When lymphocytes were preincubated with Se at concentrations as low as 0.2 microgram/ml for a period of 48 h, a significant inhibitory effect on NK activity was observed. In the LAK cell assay, direct addition of Se at concentrations of 0.2-1.0 microgram/ml to a mixture of target and effector cells did not show any effects on LAK cell activity, whereas LAK cells generated in the presence of Se at 0.8 microgram/ml showed significant inhibition of their functions. Lymphocyte proliferative responses to T cell mitogens such as phytohemagglutinin (PHA) and concanavalin A (Con A) were also significantly suppressed by direct addition of Se at 0.5-1.0 microgram/ml. The inhibitory effect of Se was not due to nonspecific toxicity of effector cells as demonstrated by viability nor was the effect directed against target cells. These studies suggest that although Se is an essential micronutrient for various immune mechanisms, an excess of Se may have a deleterious effect on certain immunological functions. As these activities are considered to be important defense mechanisms against tumors and virus infections, a nutritional imbalance of Se could result in an increased risk of these disorders.

Effects of alcohol and nicotine on cytotoxic functions of human lymphocytes

The in vitro effects of the recreational drugs, ethanol (EtOH) and nicotine, on natural killer (NK) antibody-dependent cellular cytotoxic (ADCC) and lymphokine-activated killer (LAK) cell activities on normal lymphocytes were investigated. Lymphocytes precultured with EtOH at concentrations of 0.4 and 0.6% (v/v) produced significant suppression of NK and ADCC activities. In target-binding assays, EtOH decreased the target-binding capacity of effector cells. EtOH also inhibited the activities of Percoll-separated, NK-enriched large granular lymphocytes. EtOH-induced inhibition of NK activity could be reversed by incubating lymphocytes for 1 hr with interferon. The generation and lytic capacity of LAK cells was also significantly depressed by EtOH when added at the initiation of culture. Nicotine at concentrations of 5 and 10 micrograms/ml, when added directly to mixtures of effector and target cells, produced significant inhibition of NK activity. Nicotine (2 micrograms/ml) and EtOH (0.01, 0.1, and 0.2%) at noninhibitory concentrations when added separately, showed significant suppression of NK activity when used in combination. Pretreatment of target cells with either EtOH or nicotine for 4 hr did not affect cytotoxic activity. Inhibition of cytotoxicity was also not due to direct toxicity of effector cells because lymphocytes treated with either EtOH or nicotine showed normal 51Cr release and their viability was comparable to that of untreated control cells. These studies demonstrate that EtOH and nicotine have significant immunomodulatory effects on the cytotoxic activities of human lymphocytes which may be of clinical relevance.

Intravenous immunoglobulin (IVIG) for the therapy of autoimmune disorders

The weight of evidence from numerous clinical studies supports the use of IVIG, particularly at higher doses, in the treatment of a wide range of autoimmune disorders. Extensive experience has documented the safety of IVIG therapy but its present relatively high cost necessitates firmly establishing its efficacy. There is an acute need to define those disease states where IVIG is indicated and effective. Large-scale, possibly multicentered, clinical trials employing rigorous controls will resolve these questions. Concurrent fundamental immunologic studies will elucidate the mechanisms underlying the clinical effects. We are experiencing an exciting new era of effective immunotherapies and intravenous gamma-globulin preparations have already secured an important place in the therapeutic armamentarium. While one must guard against unsubstantiated applications, critical exploration of new uses for this unique product is warranted.

Apical closure in the presence of pulpal necrosis: report of two cases

This article reports apical closure in two cases in which necrotic pulps were present and no endodontic treatment was performed prior to closure. Possible mechanisms for the occurrence are suggested.

Use of intravenous immune globulin in the treatment of seizure disorders

Recurrent seizures are a significant cause of childhood morbidity. Often the underlying pathogenesis is unknown. Studies from several laboratories have suggested a relationship between perturbations of humoral immunity and clinical epilepsy. Brain-specific antigens have been observed in the systemic circulation after brain injury. This can be followed by the appearance of antibodies to neuronal tissues in both serum and cerebrospinal fluid. Moreover, there appears to be disproportionate representation of persons with coexisting humoral immune deficiencies among patients with chronic epilepsy. Interestingly, a potent immunosuppressant, adrenocorticotropic hormone, has long been the principal treatment for infantile spasms. Given this body of information associating humoral immunity with recurrent seizures, several investigators have recently attempted to treat intractable childhood epilepsy with high-dose intravenous immune globulin. Although the number of patients treated is small and it is not possible to make comparisons between individual studies, nevertheless the results have been encouraging. Five patients with intractable seizures who failed to respond to conventional therapy were treated with an outpatient regimen of intravenous immune globulin (1 gm/kg/day) for 2 days. Two patients showed significant clinical improvement while a third had an equivocal response. Immunologic analysis of these patients before therapy revealed a surprisingly high incidence of immune abnormalities. We conclude that intravenous immune globulin may be useful in the treatment of selected patients with chronic epilepsy unresponsive to anticonvulsants.

Recombinant interleukin 2 therapy in severe combined immunodeficiency disease

Severe combined immunodeficiency disease (SCID) is a congenital disorder of severe B- and T-lymphocyte dysfunction in which several pathogenic mechanisms have been identified. The present study describes a female child with SCID who had a primary defect in the ability of T cells to secrete interleukin 2 (IL-2). B- and T-cell numbers were normal, but their functions were severely deficient. Mitogen and antigen-driven lymphoproliferative responses were diminished but were correctable in vitro with recombinant IL-2 (rIL-2). The patient's phytohemagglutinin-stimulated lymphocytes expressed IL-2 receptors normally. Despite the presence of the gene for IL-2, the patient's cells were grossly deficient in messenger RNA for IL-2 and endogenous IL-2 production. Pokeweed mitogen-driven B-cell differentiation was decreased and was not corrected by the addition of normal T cells to the B cells. Two attempts at immune reconstitution by haploidentical bone marrow transplantation failed. Therapy with rIL-2 (30,000 units/kg, given daily i.v.) resulted in marked clinical improvement as well in improved T-cell functions. The child, now 3 yr old, has been on rIL-2 therapy for 2 yr and receives rIL-2 (30,000 units/kg) three times weekly at home. This case study points to a new direction in the treatment of such disorders with rIL-2.